Merge pull request #3 in ~JHENDERSON/hdf5 from develop to feature/parallel_filters

* commit 'b359e8f1a2349d177e70d34560d0a089ce37c4c8':
  Description:     Removed "#ifndef H5_NO_DEPRECATED_SYMBOLS" in file space tests,     because the wrappers only use the latest functions now. Platforms tested:     Linux/32 2.6 (jam)     Linux/64 (platypus)     Darwin (osx1010test)
  Purpose: Add new C++ wrappers Description:     Because H5Pset_file_space and H5Pget_file_space are deprecated, changed     to make wrappers for the new functions instead:         H5Ps/get_file_space_strategy         H5Ps/get_file_space_page_size
  Description:     Fixed typos. Platforms tested:     Linux/64 (jelly)
  Description:     Deprecating versions of PropList::setProperty that have arguments that     miss "const" Platforms tested:     Linux/64 (jelly)     Linux/64 (platypus)     Darwin (osx1010test)
  Description:     Miscellaneous clean-up: format and comments Platforms tested:     Linux/64 (jelly)     Darwin (osx1010test)
  Add toolset option to cmake configure
  Update cmake pubconf to match autotools and add strtoll checks
  Switch from HDatoll to HDstrtoll, for Windows compatibility.
  output_filter.sh:         Comment added to address HDFFV-8270.  The sample ontput in the         file's comments are not up-to-date with the scripts in the file         that remove output unique to certain systems when running test         scripts.  This output doesn't match expected output files for         the tests, causing them to fail.  Ther output_filter.sh file         removes such output.  Currently we don't have access to these         systems to update the comments.
  Correct double sourcedir name on copied datafiles.
  HDFFV-10138 Merge app framework to examples
  Final merge of page buffering branch to develop
  Purpose: Add new C++ wrappers Description:     Added wrappers for H5Iis_valid, H5Ps/get_nlinks, H5Tget_create_plist,     H5Oopen, H5Oclose and H5Pset_virtual
  Bring changes to I/O parameters from page_buffering branch.
  Merge in reentrency changes to "make space in cache" from page_buffering branch.
  Minor cleanups and bring over "prefetched dirty" fixes for entries loaded from a cache image.
  Remove some usage of "prefetched_dirty" flag (which hasn't been merged from the page_buffering branch yet.  Also, bring over improvements to flush candidate entries for parallel code.
  Align with incoming page buffering changes: minor cleanups, centralize removing entries from collective metadata read list

62 files changed, 8793 insertions, 2472 deletions

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index ef361b2..9321bbd 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -195,6 +195,7 @@ set (H5F_SOURCES
     ${HDF5_SRC_DIR}/H5Fmpi.c
     ${HDF5_SRC_DIR}/H5Fquery.c
     ${HDF5_SRC_DIR}/H5Fsfile.c
+    ${HDF5_SRC_DIR}/H5Fspace.c
     ${HDF5_SRC_DIR}/H5Fsuper.c
     ${HDF5_SRC_DIR}/H5Fsuper_cache.c
     ${HDF5_SRC_DIR}/H5Ftest.c
@@ -504,6 +505,15 @@ set (H5P_HDRS
 )
 IDE_GENERATED_PROPERTIES ("H5P" "${H5P_HDRS}" "${H5P_SOURCES}" )
 
+set (H5PB_SOURCES
+    ${HDF5_SRC_DIR}/H5PB.c
+)
+
+set (H5PB_HDRS
+    ${HDF5_SRC_DIR}/H5PBpkg.h
+)
+IDE_GENERATED_PROPERTIES ("H5PB" "${H5PB_HDRS}" "${H5PB_SOURCES}" )
+
 set (H5PL_SOURCES
     ${HDF5_SRC_DIR}/H5PL.c
 )
@@ -699,6 +709,7 @@ set (common_SRCS
     ${H5MP_SOURCES}
     ${H5O_SOURCES}
     ${H5P_SOURCES}
+    ${H5PB_SOURCES}
     ${H5PL_SOURCES}
     ${H5R_SOURCES}
     ${H5UC_SOURCES}
@@ -739,6 +750,7 @@ set (H5_PUBLIC_HEADERS
     ${H5MP_HDRS}
     ${H5O_HDRS}
     ${H5P_HDRS}
+    ${H5PB_HDRS}
     ${H5PL_HDRS}
     ${H5R_HDRS}
     ${H5S_HDRS}
@@ -777,6 +789,7 @@ set (H5_PRIVATE_HEADERS
     ${HDF5_SRC_DIR}/H5MPprivate.h
     ${HDF5_SRC_DIR}/H5Oprivate.h
     ${HDF5_SRC_DIR}/H5Pprivate.h
+    ${HDF5_SRC_DIR}/H5PBprivate.h
     ${HDF5_SRC_DIR}/H5PLprivate.h
     ${HDF5_SRC_DIR}/H5UCprivate.h
     ${HDF5_SRC_DIR}/H5Rprivate.h
diff --git a/src/H5AC.c b/src/H5AC.c
index ee68a6f..a561852 100644
--- a/src/H5AC.c
+++ b/src/H5AC.c
@@ -353,6 +353,44 @@ H5AC_term_package(void)
 
 
 /*-------------------------------------------------------------------------
+ *
+ * Function:    H5AC_cache_image_pending()
+ *
+ * Purpose:     Debugging function that tests to see if the load of a 
+ *              metadata cache image load is pending (i.e. will be executed
+ *              on the next protect or insert)
+ *              
+ *              Returns TRUE if a cache image load is pending, and FALSE
+ *              if not.  Throws an assertion failure on error.
+ *
+ * Return:      TRUE if a cache image load is pending, and FALSE otherwise.
+ *
+ * Programmer:  John Mainzer, 1/10/17
+ *
+ * Changes:     None.
+ *
+ *-------------------------------------------------------------------------
+ */
+hbool_t
+H5AC_cache_image_pending(const H5F_t *f)
+{
+    H5C_t *cache_ptr;
+    hbool_t ret_value = FALSE;          /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    /* Sanity checks */
+    HDassert(f);
+    HDassert(f->shared);
+    cache_ptr = f->shared->cache;
+
+    ret_value = H5C_cache_image_pending(cache_ptr);
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5AC_cache_image_pending() */
+
+
+/*-------------------------------------------------------------------------
  * Function:    H5AC_create
  *
  * Purpose:     Initialize the cache just after a file is opened.  The
@@ -501,7 +539,7 @@ H5AC_create(const H5F_t *f, H5AC_cache_config_t *config_ptr, H5AC_cache_image_co
     /* Turn on metadata cache logging, if being used */
     if(H5F_USE_MDC_LOGGING(f)) {
         if(H5C_set_up_logging(f->shared->cache, H5F_MDC_LOG_LOCATION(f), H5F_START_MDC_LOG_ON_ACCESS(f)) < 0)
-            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "mdc logging setup failed")
+            HGOTO_ERROR(H5E_CACHE, H5E_CANTINIT, FAIL, "mdc logging setup failed")
 
         /* Write the log header regardless of current logging status */
         if(H5AC__write_create_cache_log_msg(f->shared->cache) < 0)
@@ -510,9 +548,9 @@ H5AC_create(const H5F_t *f, H5AC_cache_config_t *config_ptr, H5AC_cache_image_co
 
     /* Set the cache parameters */
     if(H5AC_set_cache_auto_resize_config(f->shared->cache, config_ptr) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_CANTALLOC, FAIL, "auto resize configuration failed")
+        HGOTO_ERROR(H5E_CACHE, H5E_CANTSET, FAIL, "auto resize configuration failed")
 
-    /* don't need to get the current H5C image config here since the
+    /* Don't need to get the current H5C image config here since the
      * cache has just been created, and thus f->shared->cache->image_ctl 
      * must still set to its initial value (H5C__DEFAULT_CACHE_IMAGE_CTL).  
      * Note that this not true as soon as control returns to the application
@@ -522,9 +560,8 @@ H5AC_create(const H5F_t *f, H5AC_cache_config_t *config_ptr, H5AC_cache_image_co
     int_ci_config.generate_image     = image_config_ptr->generate_image;
     int_ci_config.save_resize_status = image_config_ptr->save_resize_status;
     int_ci_config.entry_ageout       = image_config_ptr->entry_ageout;
-
     if(H5C_set_cache_image_config(f, f->shared->cache, &int_ci_config) < 0)
-        HGOTO_ERROR(H5E_CACHE, H5E_CANTALLOC, FAIL, "auto resize configuration failed")
+        HGOTO_ERROR(H5E_CACHE, H5E_CANTSET, FAIL, "auto resize configuration failed")
 
 done:
 #ifdef H5_HAVE_PARALLEL
@@ -836,6 +873,46 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:    H5AC_force_cache_image_load()
+ *
+ * Purpose:     On rare occasions, it is necessary to run 
+ *              H5MF_tidy_self_referential_fsm_hack() prior to the first
+ *              metadata cache access.  This is a problem as if there is a 
+ *              cache image at the end of the file, that routine will 
+ *              discard it.
+ *
+ *              We solve this issue by calling this function, which will
+ *              load the cache image and then call 
+ *              H5MF_tidy_self_referential_fsm_hack() to discard it.
+ *
+ * Return:      SUCCEED on success, and FAIL on failure.
+ *
+ * Programmer:  John Mainzer
+ *              1/11/17
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5AC_force_cache_image_load(H5F_t *f, hid_t dxpl_id)
+{
+    herr_t ret_value = SUCCEED;      /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(f);
+    HDassert(f->shared);
+    HDassert(f->shared->cache);
+
+    if(H5C_force_cache_image_load(f, dxpl_id) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_CANTLOAD, FAIL, "Can't load cache image")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5AC_force_cache_image_load() */
+
+
+/*-------------------------------------------------------------------------
  * Function:    H5AC_get_entry_status
  *
  * Purpose:     Given a file address, determine whether the metadata
@@ -3120,6 +3197,48 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:    H5AC_unsettle_ring()
+ *
+ * Purpose:     Advise the metadata cache that the specified free space
+ *              manager ring is no longer settled (if it was on entry).
+ *
+ *              If the target free space manager ring is already
+ *              unsettled, do nothing, and return SUCCEED.
+ *
+ *              If the target free space manager ring is settled, and
+ *              we are not in the process of a file shutdown, mark
+ *              the ring as unsettled, and return SUCCEED.
+ *
+ *              If the target free space manager is settled, and we
+ *              are in the process of a file shutdown, post an error
+ *              message, and return FAIL.
+ *
+ *              Note that this function simply passes the call on to
+ *              the metadata cache proper, and returns the result.
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  John Mainzer
+ *              10/15/16
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5AC_unsettle_ring(H5F_t * f, H5C_ring_t ring)
+{
+    herr_t              ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    if(FAIL == (ret_value = H5C_unsettle_ring(f, ring)))
+        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "H5C_unsettle_ring() failed")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5AC_unsettle_ring() */
+
+
+/*-------------------------------------------------------------------------
  * Function:    H5AC_remove_entry()
  *
  * Purpose:     Remove an entry from the cache.  Must be not protected, pinned,
diff --git a/src/H5ACdbg.c b/src/H5ACdbg.c
index 8ca5102..6073288 100644
--- a/src/H5ACdbg.c
+++ b/src/H5ACdbg.c
@@ -101,6 +101,7 @@ H5AC_stats(const H5F_t *f)
     FUNC_LEAVE_NOAPI(SUCCEED)
 } /* H5AC_stats() */
 
+#ifndef NDEBUG
 
 /*-------------------------------------------------------------------------
  * Function:    H5AC_dump_cache
@@ -133,6 +134,7 @@ H5AC_dump_cache(const H5F_t *f)
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5AC_dump_cache() */
+#endif /* NDEBUG */
 
 
 /*-------------------------------------------------------------------------
diff --git a/src/H5ACprivate.h b/src/H5ACprivate.h
index 1fe6456..1f8299b 100644
--- a/src/H5ACprivate.h
+++ b/src/H5ACprivate.h
@@ -451,6 +451,8 @@ H5_DLL herr_t H5AC_validate_config(H5AC_cache_config_t *config_ptr);
 H5_DLL herr_t H5AC_load_cache_image_on_next_protect(H5F_t *f, haddr_t addr, 
     hsize_t len, hbool_t rw);
 H5_DLL herr_t H5AC_validate_cache_image_config(H5AC_cache_image_config_t *config_ptr);
+H5_DLL hbool_t H5AC_cache_image_pending(const H5F_t *f);
+H5_DLL herr_t H5AC_force_cache_image_load(H5F_t * f, hid_t dxpl_id);
 
 /* Tag & Ring routines */
 H5_DLL herr_t H5AC_tag(hid_t dxpl_id, haddr_t metadata_tag, haddr_t *prev_tag);
@@ -464,6 +466,7 @@ H5_DLL herr_t H5AC_set_ring(hid_t dxpl_id, H5AC_ring_t ring, H5P_genplist_t **dx
     H5AC_ring_t *orig_ring);
 H5_DLL herr_t H5AC_reset_ring(H5P_genplist_t *dxpl, H5AC_ring_t orig_ring);
 H5_DLL herr_t H5AC_unsettle_entry_ring(void *entry);
+H5_DLL herr_t H5AC_unsettle_ring(H5F_t * f, H5AC_ring_t ring);
 H5_DLL herr_t H5AC_expunge_tag_type_metadata(H5F_t *f, hid_t dxpl_id, haddr_t tag, int type_id, unsigned flags);
 H5_DLL herr_t H5AC_get_tag(const void *thing, /*OUT*/ haddr_t *tag);
 
@@ -482,8 +485,8 @@ H5_DLL herr_t H5AC_add_candidate(H5AC_t * cache_ptr, haddr_t addr);
 
 /* Debugging functions */
 H5_DLL herr_t H5AC_stats(const H5F_t *f);
-H5_DLL herr_t H5AC_dump_cache(const H5F_t *f);
 #ifndef NDEBUG
+H5_DLL herr_t H5AC_dump_cache(const H5F_t *f);
 H5_DLL herr_t H5AC_get_entry_ptr_from_addr(const H5F_t *f, haddr_t addr,
     void **entry_ptr_ptr);
 H5_DLL herr_t H5AC_flush_dependency_exists(H5F_t *f, haddr_t parent_addr,
diff --git a/src/H5C.c b/src/H5C.c
index 805b4f5..120abb8 100644
--- a/src/H5C.c
+++ b/src/H5C.c
@@ -386,6 +386,7 @@ H5C_create(size_t		      max_cache_size,
     cache_ptr->cache_full			= FALSE;
     cache_ptr->size_decreased			= FALSE;
     cache_ptr->resize_in_progress		= FALSE;
+    cache_ptr->msic_in_progress			= FALSE;
 
     (cache_ptr->resize_ctl).version		= H5C__CURR_AUTO_SIZE_CTL_VER;
     (cache_ptr->resize_ctl).rpt_fcn		= NULL;
@@ -731,7 +732,8 @@ herr_t
 H5C_prep_for_file_close(H5F_t *f, hid_t dxpl_id)
 {
     H5C_t *     cache_ptr;
-    herr_t	ret_value = SUCCEED;      /* Return value */
+    hbool_t     image_generated = FALSE;        /* Whether a cache image was generated */
+    herr_t	ret_value = SUCCEED;            /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
 
@@ -755,9 +757,48 @@ H5C_prep_for_file_close(H5F_t *f, hid_t dxpl_id)
     HDassert(cache_ptr->pl_len == 0);
 
     /* Prepare cache image */
-    if(H5C__prep_image_for_file_close(f, dxpl_id) < 0)
+    if(H5C__prep_image_for_file_close(f, dxpl_id, &image_generated) < 0)
         HGOTO_ERROR(H5E_CACHE, H5E_CANTCREATE, FAIL, "can't create cache image")
 
+#ifdef H5_HAVE_PARALLEL
+    if(!image_generated && cache_ptr->aux_ptr != NULL && f->shared->fs_persist) {
+        /* If persistent free space managers are enabled, flushing the
+         * metadata cache may result in the deletion, insertion, and/or
+         * dirtying of entries.
+         *
+         * This is a problem in PHDF5, as it breaks two invariants of
+         * our management of the metadata cache across all processes:
+         *
+         * 1) Entries will not be dirtied, deleted, inserted, or moved
+         *    during flush in the parallel case.
+         *
+         * 2) All processes contain the same set of dirty metadata
+         *    entries on entry to a sync point.
+         *
+         * To solve this problem for the persistent free space managers,
+         * serialize the metadata cache on all processes prior to the
+         * first sync point on file shutdown.  The shutdown warning is
+         * a convenient location for this call.
+         *
+         * This is sufficient since:
+         *
+         * 1) FSM settle routines are only invoked on file close.  Since
+         *    serialization make the same settle calls as flush on file
+         *    close, and since the close warning is issued after all
+         *    non FSM related space allocations and just before the
+         *    first sync point on close, this call will leave the caches
+         *    in a consistant state across the processes if they were
+         *    consistant before.
+         *
+         * 2) Since the FSM settle routines are only invoked once during
+         *    file close, invoking them now will prevent their invocation
+         *    during a flush, and thus avoid any resulting entrie dirties,
+         *    deletions, insertion, or moves during the flush.
+         */
+        if(H5C__serialize_cache(f, dxpl_id) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_CANTSERIALIZE, FAIL, "serialization of the cache failed")
+    } /* end if */
+#endif /* H5_HAVE_PARALLEL */
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -925,12 +966,6 @@ H5C_expunge_entry(H5F_t *f, hid_t dxpl_id, const H5C_class_t *type,
         HGOTO_ERROR(H5E_CACHE, H5E_CANTEXPUNGE, FAIL, "Target entry is protected")
     if(entry_ptr->is_pinned)
         HGOTO_ERROR(H5E_CACHE, H5E_CANTEXPUNGE, FAIL, "Target entry is pinned")
-#ifdef H5_HAVE_PARALLEL
-    if(entry_ptr->coll_access) {
-        entry_ptr->coll_access = FALSE;
-        H5C__REMOVE_FROM_COLL_LIST(cache_ptr, entry_ptr, FAIL)
-    } /* end if */
-#endif /* H5_HAVE_PARALLEL */
 
     /* If we get this far, call H5C__flush_single_entry() with the
      * H5C__FLUSH_INVALIDATE_FLAG and the H5C__FLUSH_CLEAR_ONLY_FLAG.
@@ -1465,10 +1500,15 @@ H5C_insert_entry(H5F_t *             f,
     entry_ptr->prefetched			= FALSE;
     entry_ptr->prefetch_type_id			= 0;
     entry_ptr->age				= 0;
+    entry_ptr->prefetched_dirty                 = FALSE;
 #ifndef NDEBUG  /* debugging field */
     entry_ptr->serialization_count		= 0;
 #endif /* NDEBUG */
 
+    entry_ptr->tl_next  = NULL;
+    entry_ptr->tl_prev  = NULL;
+    entry_ptr->tag_info = NULL;
+
     /* Apply tag to newly inserted entry */
     if(H5C__tag_entry(cache_ptr, entry_ptr, dxpl_id) < 0)
         HGOTO_ERROR(H5E_CACHE, H5E_CANTTAG, FAIL, "Cannot tag metadata entry")
@@ -2437,7 +2477,7 @@ H5C_protect(H5F_t *		f,
            marked as collective, and is clean, it is possible that
            other processes will not have it in its cache and will
            expect a bcast of the entry from process 0. So process 0
-           will bcast the entry to all other ranks. Ranks that do have
+           will bcast the entry to all other ranks. Ranks that _do_ have
            the entry in their cache still have to participate in the
            bcast. */
 #ifdef H5_HAVE_PARALLEL
@@ -3537,6 +3577,73 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:    H5C_unsettle_ring()
+ *
+ * Purpose:     Advise the metadata cache that the specified free space
+ *              manager ring is no longer settled (if it was on entry).
+ *
+ *              If the target free space manager ring is already
+ *              unsettled, do nothing, and return SUCCEED.
+ *
+ *              If the target free space manager ring is settled, and
+ *              we are not in the process of a file shutdown, mark
+ *              the ring as unsettled, and return SUCCEED.
+ *
+ *              If the target free space manager is settled, and we
+ *              are in the process of a file shutdown, post an error
+ *              message, and return FAIL.
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  John Mainzer
+ *              10/15/16
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5C_unsettle_ring(H5F_t * f, H5C_ring_t ring)
+{
+    H5C_t *             cache_ptr;
+    herr_t ret_value = SUCCEED; /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(f);
+    HDassert(f->shared);
+    HDassert(f->shared->cache);
+    HDassert((H5C_RING_RDFSM == ring) || (H5C_RING_MDFSM == ring));
+    cache_ptr = f->shared->cache;
+    HDassert(H5C__H5C_T_MAGIC == cache_ptr->magic);
+
+    switch(ring) {
+        case H5C_RING_RDFSM:
+            if(cache_ptr->rdfsm_settled) {
+                if(cache_ptr->close_warning_received)
+                    HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unexpected rdfsm ring unsettle")
+                cache_ptr->rdfsm_settled = FALSE;
+            } /* end if */
+            break;
+
+        case H5C_RING_MDFSM:
+            if(cache_ptr->mdfsm_settled) {
+                if(cache_ptr->close_warning_received)
+                    HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "unexpected mdfsm ring unsettle")
+                cache_ptr->mdfsm_settled = FALSE;
+            } /* end if */
+            break;
+
+	default:
+	    HDassert(FALSE); /* this should be un-reachable */
+	    break;
+    } /* end switch */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C_unsettle_ring() */
+
+
+/*-------------------------------------------------------------------------
  * Function:    H5C_validate_resize_config()
  *
  * Purpose:	Run a sanity check on the specified sections of the
@@ -4586,7 +4693,7 @@ H5C__autoadjust__ageout__evict_aged_out_entries(H5F_t * f,
                 ( (entry_ptr->type)->id != H5AC_EPOCH_MARKER_ID ) &&
                 ( bytes_evicted < eviction_size_limit ) )
         {
-	    hbool_t		corked = FALSE;
+            hbool_t skipping_entry = FALSE;
 
             HDassert(entry_ptr->magic == H5C__H5C_CACHE_ENTRY_T_MAGIC);
             HDassert( ! (entry_ptr->is_protected) );
@@ -4600,9 +4707,11 @@ H5C__autoadjust__ageout__evict_aged_out_entries(H5F_t * f,
                 prev_is_dirty = prev_ptr->is_dirty;
 
             if(entry_ptr->is_dirty ) {
+                HDassert(!entry_ptr->prefetched_dirty);
+
                 /* dirty corked entry is skipped */
                 if(entry_ptr->tag_info && entry_ptr->tag_info->corked)
-                    corked = TRUE;
+                    skipping_entry = TRUE;
                 else {
                     /* reset entries_removed_counter and
                      * last_entry_removed_ptr prior to the call to
@@ -4622,16 +4731,22 @@ H5C__autoadjust__ageout__evict_aged_out_entries(H5F_t * f,
                         restart_scan = TRUE;
                 } /* end else */
             } /* end if */
-            else {
+            else if(!entry_ptr->prefetched_dirty) {
 
                 bytes_evicted += entry_ptr->size;
 
                 if(H5C__flush_single_entry(f, dxpl_id, entry_ptr, H5C__FLUSH_INVALIDATE_FLAG | H5C__DEL_FROM_SLIST_ON_DESTROY_FLAG) < 0 )
                     HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "unable to flush entry")
-            }
+            } /* end else-if */
+            else {
+                HDassert(!entry_ptr->is_dirty);
+                HDassert(entry_ptr->prefetched_dirty);
+
+                skipping_entry = TRUE;
+            } /* end else */
 
             if(prev_ptr != NULL) {
-		if(corked)   /* dirty corked entry is skipped */
+                if(skipping_entry)
                     entry_ptr = prev_ptr;
 		else if(restart_scan || (prev_ptr->is_dirty != prev_is_dirty)
                           || (prev_ptr->next != next_ptr)
@@ -4691,10 +4806,10 @@ H5C__autoadjust__ageout__evict_aged_out_entries(H5F_t * f,
 
             prev_ptr = entry_ptr->prev;
 
-            if(!(entry_ptr->is_dirty)) {
+            if(!(entry_ptr->is_dirty) && !(entry_ptr->prefetched_dirty))
                 if(H5C__flush_single_entry(f, dxpl_id, entry_ptr, H5C__FLUSH_INVALIDATE_FLAG | H5C__DEL_FROM_SLIST_ON_DESTROY_FLAG) < 0)
                     HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "unable to flush clean entry")
-            } /* end if */
+
             /* just skip the entry if it is dirty, as we can't do
              * anything with it now since we can't write.
 	     *
@@ -5999,6 +6114,7 @@ H5C__flush_single_entry(H5F_t *f, hid_t dxpl_id, H5C_cache_entry_t *entry_ptr,
     hbool_t		write_entry;		/* internal flag */
     hbool_t		destroy_entry;		/* internal flag */
     hbool_t		generate_image;		/* internal flag */
+    hbool_t		update_page_buffer;	/* internal flag */
     hbool_t		was_dirty;
     hbool_t		suppress_image_entry_writes = FALSE;
     hbool_t		suppress_image_entry_frees = FALSE;
@@ -6024,6 +6140,7 @@ H5C__flush_single_entry(H5F_t *f, hid_t dxpl_id, H5C_cache_entry_t *entry_ptr,
     del_from_slist_on_destroy = ((flags & H5C__DEL_FROM_SLIST_ON_DESTROY_FLAG) != 0);
     during_flush           = ((flags & H5C__DURING_FLUSH_FLAG) != 0);
     generate_image         = ((flags & H5C__GENERATE_IMAGE_FLAG) != 0);
+    update_page_buffer     = ((flags & H5C__UPDATE_PAGE_BUFFER_FLAG) != 0);
 
     /* Set the flag for destroying the entry, based on the 'take ownership'
      * and 'destroy' flags
@@ -6033,10 +6150,6 @@ H5C__flush_single_entry(H5F_t *f, hid_t dxpl_id, H5C_cache_entry_t *entry_ptr,
     else
         destroy_entry = destroy;
 
-#ifdef H5_HAVE_PARALLEL
-    HDassert(FALSE == entry_ptr->coll_access);
-#endif
-
     /* we will write the entry to disk if it exists, is dirty, and if the
      * clear only flag is not set.
      */
@@ -6232,9 +6345,11 @@ H5C__flush_single_entry(H5F_t *f, hid_t dxpl_id, H5C_cache_entry_t *entry_ptr,
          *
          * 2) Delete it from the skip list if requested.
          *
-         * 3) Update the replacement policy for eviction
+         * 3) Delete it from the collective read access list.
          *
-         * 4) Remove it from the tag list for this object
+         * 4) Update the replacement policy for eviction
+         *
+         * 5) Remove it from the tag list for this object
          *
          * Finally, if the destroy_entry flag is set, discard the 
          * entry.
@@ -6244,6 +6359,14 @@ H5C__flush_single_entry(H5F_t *f, hid_t dxpl_id, H5C_cache_entry_t *entry_ptr,
         if(entry_ptr->in_slist && del_from_slist_on_destroy)
             H5C__REMOVE_ENTRY_FROM_SLIST(cache_ptr, entry_ptr, during_flush)
 
+#ifdef H5_HAVE_PARALLEL
+        /* Check for collective read access flag */
+        if(entry_ptr->coll_access) {
+            entry_ptr->coll_access = FALSE;
+            H5C__REMOVE_FROM_COLL_LIST(cache_ptr, entry_ptr, FAIL)
+        } /* end if */
+#endif /* H5_HAVE_PARALLEL */
+
         H5C__UPDATE_RP_FOR_EVICTION(cache_ptr, entry_ptr, FAIL)
 
         /* Remove entry from tag list */
@@ -6290,7 +6413,8 @@ H5C__flush_single_entry(H5F_t *f, hid_t dxpl_id, H5C_cache_entry_t *entry_ptr,
                 HGOTO_ERROR(H5E_CACHE, H5E_CANTNOTIFY, FAIL, "can't notify client about entry dirty flag cleared")
 
             /* Propagate the clean flag up the flush dependency chain if appropriate */
-            HDassert(entry_ptr->flush_dep_ndirty_children == 0);
+            if(entry_ptr->flush_dep_ndirty_children != 0)
+                HDassert(entry_ptr->flush_dep_ndirty_children == 0);
             if(entry_ptr->flush_dep_nparents > 0)
                 if(H5C__mark_flush_dep_clean(entry_ptr) < 0)
                     HGOTO_ERROR(H5E_CACHE, H5E_CANTMARKDIRTY, FAIL, "Can't propagate flush dep clean flag")
@@ -6432,6 +6556,19 @@ H5C__flush_single_entry(H5F_t *f, hid_t dxpl_id, H5C_cache_entry_t *entry_ptr,
         } /* end else */
     } /* if (destroy) */
 
+    /* Check if we have to update the page buffer with cleared entries 
+     * so it doesn't go out of date 
+     */
+    if(update_page_buffer) {
+        /* Sanity check */
+        HDassert(!destroy);
+        HDassert(entry_ptr->image_ptr);
+
+        if(f->shared->page_buf && f->shared->page_buf->page_size >= entry_ptr->size)
+            if(H5PB_update_entry(f->shared->page_buf, entry_ptr->addr, entry_ptr->size, entry_ptr->image_ptr) > 0)
+                HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "Failed to update PB with metadata cache")
+    } /* end if */
+
     if(cache_ptr->log_flush)
         if((cache_ptr->log_flush)(cache_ptr, entry_addr, was_dirty, flags) < 0)
             HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "log_flush callback failed")
@@ -6822,10 +6959,15 @@ H5C_load_entry(H5F_t *              f,
     entry->prefetched                   = FALSE;
     entry->prefetch_type_id             = 0;
     entry->age                          = 0;
+    entry->prefetched_dirty             = FALSE;
 #ifndef NDEBUG  /* debugging field */
     entry->serialization_count          = 0;
 #endif /* NDEBUG */
 
+    entry->tl_next  = NULL;
+    entry->tl_prev  = NULL;
+    entry->tag_info = NULL;
+
     H5C__RESET_CACHE_ENTRY_STATS(entry);
 
     ret_value = thing;
@@ -6864,13 +7006,6 @@ done:
  *		Thus the function simply does its best, returning success
  *		unless an error is encountered.
  *
- *		The primary_dxpl_id and secondary_dxpl_id parameters
- *		specify the dxpl_ids used on the first write occasioned
- *		by the call (primary_dxpl_id), and on all subsequent
- *		writes (secondary_dxpl_id).  This is useful in the metadata
- *		cache, but may not be needed elsewhere.  If so, just use the
- *		same dxpl_id for both parameters.
- *
  *		Observe that this function cannot occasion a read.
  *
  * Return:      Non-negative on success/Negative on failure.
@@ -6886,11 +7021,13 @@ H5C__make_space_in_cache(H5F_t *f, hid_t dxpl_id, size_t space_needed,
     H5C_t *		cache_ptr = f->shared->cache;
 #if H5C_COLLECT_CACHE_STATS
     int32_t             clean_entries_skipped = 0;
+    int32_t             dirty_pf_entries_skipped = 0;
     int32_t             total_entries_scanned = 0;
 #endif /* H5C_COLLECT_CACHE_STATS */
     uint32_t		entries_examined = 0;
     uint32_t		initial_list_len;
     size_t		empty_space;
+    hbool_t             reentrant_call = FALSE;
     hbool_t		prev_is_dirty = FALSE;
     hbool_t             didnt_flush_entry = FALSE;
     hbool_t		restart_scan;
@@ -6908,6 +7045,18 @@ H5C__make_space_in_cache(H5F_t *f, hid_t dxpl_id, size_t space_needed,
     HDassert(cache_ptr->magic == H5C__H5C_T_MAGIC);
     HDassert(cache_ptr->index_size == (cache_ptr->clean_index_size + cache_ptr->dirty_index_size));
 
+    /* check to see if cache_ptr->msic_in_progress is TRUE.  If it, this
+     * is a re-entrant call via a client callback called in the make 
+     * space in cache process.  To avoid an infinite recursion, set 
+     * reentrant_call to TRUE, and goto done.
+     */
+    if(cache_ptr->msic_in_progress) {
+        reentrant_call = TRUE;
+        HGOTO_DONE(SUCCEED);
+    } /* end if */
+
+    cache_ptr->msic_in_progress = TRUE;
+
     if ( write_permitted ) {
         restart_scan = FALSE;
         initial_list_len = cache_ptr->LRU_list_len;
@@ -6954,7 +7103,8 @@ H5C__make_space_in_cache(H5F_t *f, hid_t dxpl_id, size_t space_needed,
                 didnt_flush_entry = TRUE;
 
 	    } else if ( ( (entry_ptr->type)->id != H5AC_EPOCH_MARKER_ID ) &&
-                 ( ! entry_ptr->flush_in_progress ) ) {
+                        ( ! entry_ptr->flush_in_progress ) &&
+                        ( ! entry_ptr->prefetched_dirty ) ) {
 
                 didnt_flush_entry = FALSE;
 
@@ -6980,13 +7130,6 @@ H5C__make_space_in_cache(H5F_t *f, hid_t dxpl_id, size_t space_needed,
                     cache_ptr->entries_removed_counter = 0;
                     cache_ptr->last_entry_removed_ptr  = NULL;
 
-#ifdef H5_HAVE_PARALLEL
-                    if(TRUE == entry_ptr->coll_access) {
-                        entry_ptr->coll_access = FALSE;
-                        H5C__REMOVE_FROM_COLL_LIST(cache_ptr, entry_ptr, FAIL)
-                    } /* end if */
-#endif
-
                     if(H5C__flush_single_entry(f, dxpl_id, entry_ptr, H5C__NO_FLAGS_SET) < 0)
                         HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "unable to flush entry")
 
@@ -7020,10 +7163,16 @@ H5C__make_space_in_cache(H5F_t *f, hid_t dxpl_id, size_t space_needed,
 
             } else {
 
-                /* Skip epoch markers and entries that are in the process
-                 * of being flushed.
+                /* Skip epoch markers, entries that are in the process
+                 * of being flushed, and entries marked as prefetched_dirty
+                 * (occurs in the R/O case only).
                  */
                 didnt_flush_entry = TRUE;
+
+#if H5C_COLLECT_CACHE_STATS
+                if(entry_ptr->prefetched_dirty)
+                    dirty_pf_entries_skipped++;
+#endif /* H5C_COLLECT_CACHE_STATS */
             }
 
 	    if ( prev_ptr != NULL ) {
@@ -7088,6 +7237,7 @@ H5C__make_space_in_cache(H5F_t *f, hid_t dxpl_id, size_t space_needed,
         cache_ptr->calls_to_msic++;
 
         cache_ptr->total_entries_skipped_in_msic += clean_entries_skipped;
+        cache_ptr->total_dirty_pf_entries_skipped_in_msic += dirty_pf_entries_skipped;
         cache_ptr->total_entries_scanned_in_msic += total_entries_scanned;
 
         if ( clean_entries_skipped > cache_ptr->max_entries_skipped_in_msic ) {
@@ -7095,6 +7245,9 @@ H5C__make_space_in_cache(H5F_t *f, hid_t dxpl_id, size_t space_needed,
             cache_ptr->max_entries_skipped_in_msic = clean_entries_skipped;
         }
 
+        if(dirty_pf_entries_skipped > cache_ptr->max_dirty_pf_entries_skipped_in_msic)
+            cache_ptr->max_dirty_pf_entries_skipped_in_msic = dirty_pf_entries_skipped;
+
         if ( total_entries_scanned > cache_ptr->max_entries_scanned_in_msic ) {
 
             cache_ptr->max_entries_scanned_in_msic = total_entries_scanned;
@@ -7163,6 +7316,12 @@ H5C__make_space_in_cache(H5F_t *f, hid_t dxpl_id, size_t space_needed,
     }
 
 done:
+    /* Sanity checks */
+    HDassert(cache_ptr->msic_in_progress);
+    if(!reentrant_call)
+        cache_ptr->msic_in_progress = FALSE;
+    HDassert((!reentrant_call) || (cache_ptr->msic_in_progress));
+
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5C__make_space_in_cache() */
 
@@ -8723,12 +8882,21 @@ H5C_remove_entry(void *_entry)
     /* Update the cache internal data structures as appropriate for a destroy.
      * Specifically:
      *	1) Delete it from the index
-     *	2) Update the replacement policy for eviction
-     *	3) Remove it from the tag list for this object
+     *	2) Delete it from the collective read access list
+     *	3) Update the replacement policy for eviction
+     *	4) Remove it from the tag list for this object
      */
 
     H5C__DELETE_FROM_INDEX(cache, entry, FAIL)
 
+#ifdef H5_HAVE_PARALLEL
+    /* Check for collective read access flag */
+    if(entry->coll_access) {
+        entry->coll_access = FALSE;
+        H5C__REMOVE_FROM_COLL_LIST(cache, entry, FAIL)
+    } /* end if */
+#endif /* H5_HAVE_PARALLEL */
+
     H5C__UPDATE_RP_FOR_EVICTION(cache, entry, FAIL)
 
     /* Remove entry from tag list */
diff --git a/src/H5Cdbg.c b/src/H5Cdbg.c
index eb5f123..a955eaf 100644
--- a/src/H5Cdbg.c
+++ b/src/H5Cdbg.c
@@ -70,6 +70,7 @@
 /*******************/
 
 
+#ifndef NDEBUG
 
 /*-------------------------------------------------------------------------
  * Function:    H5C_dump_cache
@@ -175,6 +176,85 @@ done:
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5C_dump_cache() */
+#endif /* NDEBUG */
+
+#ifndef NDEBUG
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C_dump_cache_LRU
+ *
+ * Purpose:     Print a summary of the contents of the metadata cache 
+ *              LRU for debugging purposes.
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  John Mainzer
+ *              10/10/10
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5C_dump_cache_LRU(H5C_t *cache_ptr, const char *cache_name)
+{
+    H5C_cache_entry_t * entry_ptr;
+    int                 i = 0;
+
+    FUNC_ENTER_NOAPI_NOERR
+
+    /* Sanity check */
+    HDassert(cache_ptr != NULL);
+    HDassert(cache_ptr->magic == H5C__H5C_T_MAGIC);
+    HDassert(cache_name != NULL );
+
+    HDfprintf(stdout, "\n\nDump of metadata cache LRU \"%s\"\n", cache_name);
+    HDfprintf(stdout, "LRU len = %d, LRU size = %d\n", 
+              cache_ptr->LRU_list_len, (int)(cache_ptr->LRU_list_size));
+    HDfprintf(stdout, "index_size = %d, max_cache_size = %d, delta = %d\n\n", 
+              (int)(cache_ptr->index_size), (int)(cache_ptr->max_cache_size),
+              (int)(cache_ptr->max_cache_size) - (int)(cache_ptr->index_size));
+
+    /* Print header */
+    HDfprintf(stdout, "Entry ");
+    HDfprintf(stdout, "|       Address      ");
+    HDfprintf(stdout, "|         Tag        ");
+    HDfprintf(stdout, "|  Size ");
+    HDfprintf(stdout, "| Ring ");
+    HDfprintf(stdout, "|              Type              ");
+    HDfprintf(stdout, "| Dirty");
+    HDfprintf(stdout, "\n");
+
+    HDfprintf(stdout, "----------------------------------------------------------------------------------------------------------------\n");
+
+    entry_ptr = cache_ptr->LRU_head_ptr;
+    while(entry_ptr != NULL) {
+        HDassert(entry_ptr->magic == H5C__H5C_CACHE_ENTRY_T_MAGIC);
+
+        /* Print entry */
+        HDfprintf(stdout, "%s%5d ", cache_ptr->prefix, i);
+        HDfprintf(stdout, "  0x%16llx ", (long long)(entry_ptr->addr));
+
+        if(NULL == entry_ptr->tag_info)
+            HDfprintf(stdout, "    %16s ", "N/A");
+        else
+            HDfprintf(stdout, "  0x%16llx ", 
+                      (long long)(entry_ptr->tag_info->tag));
+
+        HDfprintf(stdout, "  %5lld ", (long long)(entry_ptr->size));
+        HDfprintf(stdout, "    %d  ", (int)(entry_ptr->ring));
+        HDfprintf(stdout, "  %2d %-32s ", (int)(entry_ptr->type->id), 
+                  (entry_ptr->type->name));
+        HDfprintf(stdout, " %d", (int)(entry_ptr->is_dirty));
+        HDfprintf(stdout, "\n");
+
+        i++;
+        entry_ptr = entry_ptr->next;
+    } /* end while */
+
+    HDfprintf(stdout, "----------------------------------------------------------------------------------------------------------------\n");
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* H5C_dump_cache_LRU() */
+#endif /* NDEBUG */
 
 
 /*-------------------------------------------------------------------------
@@ -385,6 +465,7 @@ H5C_stats(H5C_t * cache_ptr,
     double	average_successful_search_depth = 0.0f;
     double	average_failed_search_depth = 0.0f;
     double      average_entries_skipped_per_calls_to_msic = 0.0f;
+    double      average_dirty_pf_entries_skipped_per_call_to_msic = 0.0f;
     double      average_entries_scanned_per_calls_to_msic = 0.0f;
 #endif /* H5C_COLLECT_CACHE_STATS */
     herr_t	ret_value = SUCCEED;   /* Return value */
@@ -620,6 +701,17 @@ H5C_stats(H5C_t * cache_ptr,
               (long)(cache_ptr->max_entries_skipped_in_msic));
 
     if(cache_ptr->calls_to_msic > 0)
+        average_dirty_pf_entries_skipped_per_call_to_msic =
+            (((double)(cache_ptr->total_dirty_pf_entries_skipped_in_msic)) /
+            ((double)(cache_ptr->calls_to_msic)));
+
+    HDfprintf(stdout, 
+              "%s  MSIC: Average/max dirty pf entries skipped  = %lf / %ld\n",
+              cache_ptr->prefix,
+              average_dirty_pf_entries_skipped_per_call_to_msic,
+              (long)(cache_ptr->max_dirty_pf_entries_skipped_in_msic));
+
+    if(cache_ptr->calls_to_msic > 0)
         average_entries_scanned_per_calls_to_msic =
             (((double)(cache_ptr->total_entries_scanned_in_msic)) /
             ((double)(cache_ptr->calls_to_msic)));
@@ -887,12 +979,14 @@ H5C_stats__reset(H5C_t H5_ATTR_UNUSED * cache_ptr)
     cache_ptr->max_pel_len			= 0;
     cache_ptr->max_pel_size			= (size_t)0;
 
-    cache_ptr->calls_to_msic                    = 0;
-    cache_ptr->total_entries_skipped_in_msic    = 0;
-    cache_ptr->total_entries_scanned_in_msic    = 0;
-    cache_ptr->max_entries_skipped_in_msic      = 0;
-    cache_ptr->max_entries_scanned_in_msic      = 0;
-    cache_ptr->entries_scanned_to_make_space    = 0;
+    cache_ptr->calls_to_msic                          = 0;
+    cache_ptr->total_entries_skipped_in_msic          = 0;
+    cache_ptr->total_dirty_pf_entries_skipped_in_msic = 0;
+    cache_ptr->total_entries_scanned_in_msic          = 0;
+    cache_ptr->max_entries_skipped_in_msic            = 0;
+    cache_ptr->max_dirty_pf_entries_skipped_in_msic   = 0;
+    cache_ptr->max_entries_scanned_in_msic            = 0;
+    cache_ptr->entries_scanned_to_make_space          = 0;
 
     cache_ptr->slist_scan_restarts		= 0;
     cache_ptr->LRU_scan_restarts		= 0;
diff --git a/src/H5Cimage.c b/src/H5Cimage.c
index 1da2545..fc58dac 100644
--- a/src/H5Cimage.c
+++ b/src/H5Cimage.c
@@ -147,6 +147,40 @@ H5FL_DEFINE(H5C_cache_entry_t);
 
 
 /*-------------------------------------------------------------------------
+ *
+ * Function:    H5C_cache_image_pending()
+ *
+ * Purpose:     Tests to see if the load of a metadata cache image 
+ *              load is pending (i.e. will be executed on the next 
+ *              protect or insert)
+ *
+ *              Returns TRUE if a cache image load is pending, and FALSE
+ *              if not.  Throws an assertion failure on error.
+ *
+ * Return:      TRUE if a cache image load is pending, and FALSE otherwise.
+ *
+ * Programmer:  John Mainzer, 6/18/16
+ *
+ *-------------------------------------------------------------------------
+ */
+hbool_t
+H5C_cache_image_pending(const H5C_t *cache_ptr)
+{
+    hbool_t             ret_value = TRUE;      /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    /* Sanity checks */
+    HDassert(cache_ptr);
+    HDassert(cache_ptr->magic == H5C__H5C_T_MAGIC);
+
+    ret_value = (cache_ptr->load_image && !cache_ptr->image_loaded);
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C_cache_image_pending() */
+
+
+/*-------------------------------------------------------------------------
  * Function:    H5C_cache_image_status()
  *
  * Purpose:     Examine the metadata cache associated with the supplied 
@@ -489,7 +523,6 @@ H5C__deserialize_prefetched_entry(H5F_t *f, hid_t dxpl_id, H5C_t *cache_ptr,
      */
     HDassert(!((type->flags & H5C__CLASS_SKIP_READS) &&
                (type->flags & H5C__CLASS_SPECULATIVE_LOAD_FLAG)));
-
     HDassert(H5F_addr_defined(addr));
     HDassert(type->get_initial_load_size);
     HDassert(type->deserialize);
@@ -498,6 +531,7 @@ H5C__deserialize_prefetched_entry(H5F_t *f, hid_t dxpl_id, H5C_t *cache_ptr,
      * relationships now.  The client will restore the relationship(s) with
      * the deserialized entry if appropriate.
      */
+    HDassert(pf_entry_ptr->fd_parent_count == pf_entry_ptr->flush_dep_nparents);
     for(i = (int)(pf_entry_ptr->fd_parent_count) - 1; i >= 0; i--) {
         HDassert(pf_entry_ptr->flush_dep_parent);
         HDassert(pf_entry_ptr->flush_dep_parent[i]);
@@ -525,7 +559,7 @@ H5C__deserialize_prefetched_entry(H5F_t *f, hid_t dxpl_id, H5C_t *cache_ptr,
      */
     if(pf_entry_ptr->fd_child_count > 0) {
         if(NULL == (fd_children = (H5C_cache_entry_t **)H5MM_calloc(sizeof(H5C_cache_entry_t **) * (size_t)(pf_entry_ptr->fd_child_count + 1))))
-                HGOTO_ERROR(H5E_CACHE, H5E_CANTALLOC, FAIL, "memory allocation failed for fd child ptr array")
+            HGOTO_ERROR(H5E_CACHE, H5E_CANTALLOC, FAIL, "memory allocation failed for fd child ptr array")
 
         if(H5C__destroy_pf_entry_child_flush_deps(cache_ptr, pf_entry_ptr, fd_children) < 0)
             HGOTO_ERROR(H5E_CACHE, H5E_CANTUNDEPEND, FAIL, "can't destroy pf entry child flush dependency(s).")
@@ -544,7 +578,6 @@ H5C__deserialize_prefetched_entry(H5F_t *f, hid_t dxpl_id, H5C_t *cache_ptr,
      */
     if(NULL == (thing = type->deserialize(pf_entry_ptr->image_ptr, len, udata, &dirty)))
         HGOTO_ERROR(H5E_CACHE, H5E_CANTLOAD, FAIL, "Can't deserialize image")
-
     ds_entry_ptr = (H5C_cache_entry_t *)thing;
 
     /* In general, an entry should be clean just after it is loaded.
@@ -583,8 +616,7 @@ H5C__deserialize_prefetched_entry(H5F_t *f, hid_t dxpl_id, H5C_t *cache_ptr,
     ds_entry_ptr->image_ptr                 	= pf_entry_ptr->image_ptr;
     ds_entry_ptr->image_up_to_date          	= !dirty;
     ds_entry_ptr->type                      	= type;
-    ds_entry_ptr->is_dirty	            	= dirty | 
-						  pf_entry_ptr->is_dirty;
+    ds_entry_ptr->is_dirty	            	= dirty | pf_entry_ptr->is_dirty;
     ds_entry_ptr->dirtied                   	= FALSE;
     ds_entry_ptr->is_protected              	= FALSE;
     ds_entry_ptr->is_read_only              	= FALSE;
@@ -626,7 +658,7 @@ H5C__deserialize_prefetched_entry(H5F_t *f, hid_t dxpl_id, H5C_t *cache_ptr,
     pf_entry_ptr->coll_prev                 	= NULL;
 #endif /* H5_HAVE_PARALLEL */
 
-    /* initialize cache image related fields */
+    /* Initialize cache image related fields */
     ds_entry_ptr->include_in_image          	= FALSE;
     ds_entry_ptr->lru_rank	            	= 0;
     ds_entry_ptr->image_dirty	            	= FALSE;
@@ -638,6 +670,10 @@ H5C__deserialize_prefetched_entry(H5F_t *f, hid_t dxpl_id, H5C_t *cache_ptr,
     ds_entry_ptr->prefetched	            	= FALSE;
     ds_entry_ptr->prefetch_type_id          	= 0;
     ds_entry_ptr->age		          	= 0;
+    ds_entry_ptr->prefetched_dirty              = pf_entry_ptr->prefetched_dirty;
+#ifndef NDEBUG  /* debugging field */
+    ds_entry_ptr->serialization_count           = 0;
+#endif /* NDEBUG */
 
     H5C__RESET_CACHE_ENTRY_STATS(ds_entry_ptr);
 
@@ -666,7 +702,7 @@ H5C__deserialize_prefetched_entry(H5F_t *f, hid_t dxpl_id, H5C_t *cache_ptr,
      *     and H5C__FLUSH_CLEAR_ONLY_FLAG flags set.
      */
     pf_entry_ptr->image_ptr = NULL; 
-    if ( pf_entry_ptr->is_dirty ) {
+    if(pf_entry_ptr->is_dirty) {
         HDassert(pf_entry_ptr->in_slist);
         flush_flags |= H5C__DEL_FROM_SLIST_ON_DESTROY_FLAG;
     } /* end if */
@@ -684,7 +720,6 @@ H5C__deserialize_prefetched_entry(H5F_t *f, hid_t dxpl_id, H5C_t *cache_ptr,
     H5C__INSERT_IN_INDEX(cache_ptr, ds_entry_ptr, FAIL)
 
     HDassert(!ds_entry_ptr->in_slist);
-
     if(ds_entry_ptr->is_dirty)
         H5C__INSERT_ENTRY_IN_SLIST(cache_ptr, ds_entry_ptr, FAIL)
 
@@ -699,16 +734,13 @@ H5C__deserialize_prefetched_entry(H5F_t *f, hid_t dxpl_id, H5C_t *cache_ptr,
             (ds_entry_ptr->type->notify)(H5C_NOTIFY_ACTION_AFTER_LOAD, ds_entry_ptr) < 0)
         HGOTO_ERROR(H5E_CACHE, H5E_CANTNOTIFY, FAIL, "can't notify client about entry loaded into cache")
 
-    /* restore flush dependencies with the flush dependency children of 
+    /* Restore flush dependencies with the flush dependency children of 
      * of the prefetched entry.  Note that we must protect *ds_entry_ptr 
      * before the call to avoid triggering sanity check failures, and 
      * then unprotect it afterwards.
      */
     i = 0;
     if(fd_children != NULL) {
-        int j;
-        hbool_t found;
-
         H5C__UPDATE_RP_FOR_PROTECT(cache_ptr, ds_entry_ptr, FAIL)
         ds_entry_ptr->is_protected = TRUE;
         while(fd_children[i] != NULL) {
@@ -718,15 +750,22 @@ H5C__deserialize_prefetched_entry(H5F_t *f, hid_t dxpl_id, H5C_t *cache_ptr,
             HDassert((fd_children[i])->fd_parent_count > 0);
             HDassert((fd_children[i])->fd_parent_addrs);
 
-            j = 0;
-            found = FALSE;
-            while((j < (int)((fd_children[i])->fd_parent_count)) && (!found)) {
-                if((fd_children[i])->fd_parent_addrs[j] == ds_entry_ptr->addr)
-                    found = TRUE;
+#ifndef NDEBUG
+            {
+                int j;
+                hbool_t found;
+
+                j = 0;
+                found = FALSE;
+                while((j < (int)((fd_children[i])->fd_parent_count)) && (!found)) {
+                    if((fd_children[i])->fd_parent_addrs[j] == ds_entry_ptr->addr)
+                        found = TRUE;
 
-                j++;
-            } /* end while */
-            HDassert(found);
+                    j++;
+                } /* end while */
+                HDassert(found);
+            }
+#endif /* NDEBUG */
 
             if(H5C_create_flush_dependency(ds_entry_ptr, fd_children[i]) < 0)
                 HGOTO_ERROR(H5E_CACHE, H5E_CANTDEPEND, FAIL, "Can't restore child flush dependency")
@@ -735,7 +774,6 @@ H5C__deserialize_prefetched_entry(H5F_t *f, hid_t dxpl_id, H5C_t *cache_ptr,
         } /* end while */
 
         H5C__UPDATE_RP_FOR_UNPROTECT(cache_ptr, ds_entry_ptr, FAIL);
-
         ds_entry_ptr->is_protected = FALSE;
     } /* end if ( fd_children != NULL ) */
     HDassert((unsigned)i == ds_entry_ptr->fd_child_count);
@@ -828,6 +866,54 @@ H5C__free_image_entries_array(H5C_t * cache_ptr)
 
 
 /*-------------------------------------------------------------------------
+ * Function:    H5C_force_cache_image_load()
+ *
+ * Purpose:     On rare occasions, it is necessary to run 
+ *		H5MF_tidy_self_referential_fsm_hack() prior to the first
+ *              metadata cache access.  This is a problem as if there is a 
+ *              cache image at the end of the file, that routine will 
+ *              discard it.
+ *
+ *              We solve this issue by calling this function, which will
+ *		load the cache image and then call 
+ *              H5MF_tidy_self_referential_fsm_hack() to discard it.
+ *
+ * Return:      SUCCEED on success, and FAIL on failure.
+ *
+ * Programmer:  John Mainzer
+ *              1/11/17
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5C_force_cache_image_load(H5F_t *f, hid_t dxpl_id)
+{
+    H5C_t *cache_ptr;
+    herr_t ret_value = SUCCEED;      /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(f);
+    HDassert(f->shared);
+    cache_ptr = f->shared->cache;
+    HDassert(cache_ptr);
+    HDassert(cache_ptr->magic == H5C__H5C_T_MAGIC);
+    HDassert(cache_ptr->load_image);
+
+    /* Load the cache image, if requested */
+    if(cache_ptr->load_image) {
+        cache_ptr->load_image = FALSE;
+        if(H5C__load_cache_image(f, dxpl_id) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_CANTLOAD, FAIL, "can't load cache image")
+    } /* end if */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C_force_cache_image_load() */
+
+
+/*-------------------------------------------------------------------------
  * Function:    H5C_get_cache_image_config
  *
  * Purpose:     Copy the current configuration for cache image generation
@@ -1235,7 +1321,7 @@ H5C__image_entry_cmp(const void *_entry1, const void *_entry2)
  *-------------------------------------------------------------------------
  */
 herr_t
-H5C__prep_image_for_file_close(H5F_t *f, hid_t dxpl_id)
+H5C__prep_image_for_file_close(H5F_t *f, hid_t dxpl_id, hbool_t *image_generated)
 {
     H5C_t *     cache_ptr = NULL;
     haddr_t     eoa_frag_addr = HADDR_UNDEF;
@@ -1251,6 +1337,7 @@ H5C__prep_image_for_file_close(H5F_t *f, hid_t dxpl_id)
     cache_ptr = f->shared->cache;
     HDassert(cache_ptr);
     HDassert(cache_ptr->magic == H5C__H5C_T_MAGIC);
+    HDassert(image_generated);
 
     /* If the file is opened and closed without any access to 
      * any group or data set, it is possible that the cache image (if 
@@ -1262,6 +1349,26 @@ H5C__prep_image_for_file_close(H5F_t *f, hid_t dxpl_id)
 	    HGOTO_ERROR(H5E_CACHE, H5E_CANTLOAD, FAIL, "can't load cache image")
     } /* end if */
 
+    /* Before we start to generate the cache image (if requested), verify
+     * that the superblock supports superblock extension messages, and 
+     * silently cancel any request for a cache image if it does not.
+     *
+     * Ideally, we would do this when the cache image is requested,
+     * but the necessary information is not necessary available at that 
+     * time -- hence this last minute check.
+     *
+     * Note that under some error conditions, the superblock will be 
+     * undefined in this case as well -- if so, assume that the 
+     * superblock does not support superblock extension messages.
+     */
+    if((NULL == f->shared->sblock) ||
+         (f->shared->sblock->super_vers < HDF5_SUPERBLOCK_VERSION_2)) {
+        H5C_cache_image_ctl_t default_image_ctl = H5C__DEFAULT_CACHE_IMAGE_CTL;
+
+        cache_ptr->image_ctl = default_image_ctl;
+        HDassert(!(cache_ptr->image_ctl.generate_image));
+    } /* end if */
+
     /* Generate the cache image, if requested */
     if(cache_ptr->image_ctl.generate_image) {
         /* Create the cache image super block extension message.
@@ -1355,6 +1462,15 @@ H5C__prep_image_for_file_close(H5F_t *f, hid_t dxpl_id)
                         (hsize_t)(cache_ptr->image_data_len), &eoa_frag_addr, &eoa_frag_size)))
                 HGOTO_ERROR(H5E_CACHE, H5E_NOSPACE, FAIL, "can't allocate file space for metadata cache image")
 
+        /* Make note of the eoa after allocation of the cache image
+         * block.  This value is used for sanity checking when we
+         * shutdown the self referential free space managers after
+         * we destroy the metadata cache.
+         */
+        HDassert(HADDR_UNDEF == f->shared->eoa_post_mdci_fsalloc);
+        if(HADDR_UNDEF == (f->shared->eoa_post_mdci_fsalloc = H5FD_get_eoa(f->shared->lf, H5FD_MEM_DEFAULT)) )
+            HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "unable to get file size")
+
         /* For now, drop any fragment left over from the allocation of the
          * image block on the ground.  A fragment should only be returned
          * if the underlying file alignment is greater than 1.
@@ -1386,7 +1502,7 @@ H5C__prep_image_for_file_close(H5F_t *f, hid_t dxpl_id)
          */
         if(cache_ptr->image_ctl.flags & H5C_CI__GEN_MDC_IMAGE_BLK)
             if(H5C__write_cache_image_superblock_msg(f, dxpl_id, FALSE) < 0)
-                HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "update of cache image SB mesg failed.")
+                HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "update of cache image SB mesg failed")
 
         /* At this point:
          *
@@ -1440,10 +1556,13 @@ H5C__prep_image_for_file_close(H5F_t *f, hid_t dxpl_id)
              */
             if(cache_ptr->image_ctl.flags & H5C_CI__GEN_MDC_IMAGE_BLK)
                 if(H5F_super_ext_remove_msg(f, dxpl_id, H5O_MDCI_MSG_ID) < 0)
-                    HGOTO_ERROR(H5E_CACHE, H5E_CANTREMOVE, FAIL, "can't remove MDC image msg from superblock ext.")
+                    HGOTO_ERROR(H5E_CACHE, H5E_CANTREMOVE, FAIL, "can't remove MDC image msg from superblock ext")
 
             cache_ptr->image_ctl.generate_image = FALSE;
         } /* end else */
+
+        /* Indicate that a cache image was generated */
+        *image_generated = TRUE;
     } /* end if */
 
 done:
@@ -1458,6 +1577,18 @@ done:
  *		image_ctl field of *cache_ptr.  Make adjustments for 
  *		changes in configuration as required.
  *
+ *              If the file is open read only, silently
+ *              force the cache image configuration to its default
+ *              (which disables construction of a cache image).
+ *
+ *              Note that in addition to being inapplicable in the
+ *              read only case, cache image is also inapplicable if
+ *              the superblock does not support superblock extension 
+ *              messages.  Unfortunately, this information need not 
+ *              be available at this point. Thus we check for this 
+ *              later, in H5C_prep_for_file_close() and cancel the
+ *              cache image request if appropriate.
+ *
  *		Fail if the new configuration is invalid.
  *
  * Return:      SUCCEED on success, and FAIL on failure.
@@ -1483,26 +1614,13 @@ H5C_set_cache_image_config(const H5F_t *f, H5C_t *cache_ptr,
     /* Check arguments */
     if((cache_ptr == NULL) || (cache_ptr->magic != H5C__H5C_T_MAGIC))
         HGOTO_ERROR(H5E_CACHE, H5E_BADVALUE, FAIL, "Bad cache_ptr on entry")
-    if(config_ptr == NULL)
-        HGOTO_ERROR(H5E_CACHE, H5E_BADVALUE, FAIL, "NULL config_ptr on entry")
-    if(config_ptr->version != H5C__CURR_CACHE_IMAGE_CTL_VER)
-        HGOTO_ERROR(H5E_CACHE, H5E_BADVALUE, FAIL, "Unknown config version")
 
-    /* check general configuration section of the config: */
+    /* Validate the config: */
     if(H5C_validate_cache_image_config(config_ptr) < 0)
         HGOTO_ERROR(H5E_ARGS, H5E_BADRANGE, FAIL, "invalid cache image configuration")
 
-    if(H5F_INTENT(f) & H5F_ACC_RDWR)    /* file has been opened R/W */
-        cache_ptr->image_ctl = *config_ptr;
-    else { /* file opened R/O -- suppress cache image silently */
-	H5C_cache_image_ctl_t default_image_ctl = H5C__DEFAULT_CACHE_IMAGE_CTL;
-
-        cache_ptr->image_ctl = default_image_ctl;
-	HDassert(!(cache_ptr->image_ctl.generate_image));
-    } /* end else */
-
 #ifdef H5_HAVE_PARALLEL
-    /* the collective metadata write code is not currently compatible 
+    /* The collective metadata write code is not currently compatible 
      * with cache image.  Until this is fixed, suppress cache image silently
      * if there is more than one process.
      *                                         JRM -- 11/8/16
@@ -1513,6 +1631,30 @@ H5C_set_cache_image_config(const H5F_t *f, H5C_t *cache_ptr,
         cache_ptr->image_ctl = default_image_ctl;
 	HDassert(!(cache_ptr->image_ctl.generate_image));
     } /* end if */
+    else {
+#endif /* H5_HAVE_PARALLEL */
+        /* A cache image can only be generated if the file is opened read / write
+         * and the superblock supports superblock extension messages.  
+         *
+         * However, the superblock version is not available at this point -- 
+         * hence we can only check the former requirement now.  Do the latter
+         * check just before we construct the image..  
+         *
+         * If the file is opened read / write, apply the supplied configuration.
+         *
+         * If it is not, set the image configuration to the default, which has 
+         * the effect of silently disabling the cache image if it was requested.
+         */
+        if(H5F_INTENT(f) & H5F_ACC_RDWR)
+            cache_ptr->image_ctl = *config_ptr;
+        else {
+            H5C_cache_image_ctl_t default_image_ctl = H5C__DEFAULT_CACHE_IMAGE_CTL;
+
+            cache_ptr->image_ctl = default_image_ctl;
+            HDassert(!(cache_ptr->image_ctl.generate_image));
+        } /* end else */
+#ifdef H5_HAVE_PARALLEL
+    } /* end else */
 #endif /* H5_HAVE_PARALLEL */
 
 done:
@@ -3186,7 +3328,13 @@ H5C__reconstruct_cache_entry(const H5F_t *f, H5C_t *cache_ptr,
      * this as otherwise the cache will attempt to write them on file
      * close.  Since the file is R/O, the metadata cache image superblock
      * extension message and the cache image block will not be removed.
-     * Hence no danger in this.
+     * Hence no danger in this for subsequent opens.
+     *
+     * However, if the dirty entry (marked clean for purposes of the R/O
+     * file open) is evicted and then referred to, the cache will read
+     * either invalid or obsolete data from the file.  Handle this by 
+     * setting the prefetched_dirty field, and hiding such entries from
+     * the eviction candidate selection algorithm.
      */
     pf_entry_ptr->is_dirty = (is_dirty && file_is_rw);
 
@@ -3204,6 +3352,8 @@ H5C__reconstruct_cache_entry(const H5F_t *f, H5C_t *cache_ptr,
 
     /* Decode dirty dependency child count */
     UINT16DECODE(p, pf_entry_ptr->fd_dirty_child_count);
+    if(!file_is_rw) 
+        pf_entry_ptr->fd_dirty_child_count      = 0;
     if(pf_entry_ptr->fd_dirty_child_count > pf_entry_ptr->fd_child_count)
         HGOTO_ERROR(H5E_CACHE, H5E_BADVALUE, NULL, "invalid dirty flush dependency child count")
 
@@ -3263,6 +3413,7 @@ H5C__reconstruct_cache_entry(const H5F_t *f, H5C_t *cache_ptr,
     pf_entry_ptr->image_up_to_date		= TRUE;
     pf_entry_ptr->type				= H5AC_PREFETCHED_ENTRY;
     pf_entry_ptr->prefetched			= TRUE;
+    pf_entry_ptr->prefetched_dirty              = is_dirty && (!file_is_rw);
 
     /* Sanity checks */
     HDassert(pf_entry_ptr->size > 0 && pf_entry_ptr->size < H5C_MAX_ENTRY_SIZE);
diff --git a/src/H5Cmpio.c b/src/H5Cmpio.c
index ebb98b3..06ce714 100644
--- a/src/H5Cmpio.c
+++ b/src/H5Cmpio.c
@@ -65,6 +65,11 @@
 /* Local Prototypes */
 /********************/
 static herr_t H5C__collective_write(H5F_t *f, hid_t dxpl_id);
+static herr_t H5C__flush_candidate_entries(H5F_t *f, hid_t dxpl_id, 
+    unsigned entries_to_flush[H5C_RING_NTYPES], 
+    unsigned entries_to_clear[H5C_RING_NTYPES]);
+static herr_t H5C__flush_candidates_in_ring(H5F_t *f, hid_t dxpl_id, 
+    H5C_ring_t ring, unsigned  entries_to_flush, unsigned entries_to_clear);
 
 
 /*********************/
@@ -175,31 +180,18 @@ H5C_apply_candidate_list(H5F_t * f,
                          int mpi_rank,
                          int mpi_size)
 {
-    hbool_t		restart_scan;
-    hbool_t		prev_is_dirty;
     int                 i;
     int			m;
     int			n;
     unsigned		first_entry_to_flush;
     unsigned		last_entry_to_flush;
-    unsigned		entries_to_clear = 0;
-    unsigned		entries_to_flush = 0;
-    unsigned		entries_to_flush_or_clear_last = 0;
-    unsigned		entries_to_flush_collectively = 0;
-    unsigned		entries_cleared = 0;
-    unsigned		entries_flushed = 0;
-    unsigned		entries_delayed = 0;
-    unsigned		entries_flushed_or_cleared_last = 0;
-    unsigned		entries_flushed_collectively = 0;
-    unsigned		entries_examined = 0;
-    unsigned		initial_list_len;
+    unsigned		total_entries_to_clear = 0;
+    unsigned		total_entries_to_flush = 0;
     int               * candidate_assignment_table = NULL;
+    unsigned            entries_to_flush[H5C_RING_NTYPES];
+    unsigned            entries_to_clear[H5C_RING_NTYPES];
     haddr_t		addr;
-    H5C_cache_entry_t *	clear_ptr = NULL;
-    H5C_cache_entry_t *	next_ptr = NULL;
     H5C_cache_entry_t *	entry_ptr = NULL;
-    H5C_cache_entry_t *	flush_ptr = NULL;
-    H5C_cache_entry_t * delayed_ptr = NULL;
 #if H5C_DO_SANITY_CHECKS
     haddr_t		last_addr;
 #endif /* H5C_DO_SANITY_CHECKS */
@@ -220,6 +212,10 @@ H5C_apply_candidate_list(H5F_t * f,
     HDassert(0 <= mpi_rank);
     HDassert(mpi_rank < mpi_size);
 
+    /* Initialize the entries_to_flush and entries_to_clear arrays */
+    HDmemset(entries_to_flush, 0, sizeof(entries_to_flush));
+    HDmemset(entries_to_clear, 0, sizeof(entries_to_clear));
+
 #if H5C_APPLY_CANDIDATE_LIST__DEBUG
     HDfprintf(stdout, "%s:%d: setting up candidate assignment table.\n", FUNC, mpi_rank);
 
@@ -330,17 +326,26 @@ H5C_apply_candidate_list(H5F_t * f,
              */
             HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "Listed entry is protected?!?!?")
 
+        /* Sanity checks */
+        HDassert(entry_ptr->magic == H5C__H5C_CACHE_ENTRY_T_MAGIC);
+        HDassert(entry_ptr->ring >= H5C_RING_USER);
+        HDassert(entry_ptr->ring <= H5C_RING_SB);
+        HDassert(!entry_ptr->flush_immediately);
+        HDassert(!entry_ptr->clear_on_unprotect);
+
         /* Determine whether the entry is to be cleared or flushed,
          * and mark it accordingly.  We will scan the protected and 
          * pinned list shortly, and clear or flush according to these
          * markings.  
          */
         if(u >= first_entry_to_flush && u <= last_entry_to_flush) {
-            entries_to_flush++;
+            total_entries_to_flush++;
+            entries_to_flush[entry_ptr->ring]++;
             entry_ptr->flush_immediately = TRUE;
         } /* end if */
         else {
-            entries_to_clear++;
+            total_entries_to_clear++;
+            entries_to_clear[entry_ptr->ring]++;
             entry_ptr->clear_on_unprotect = TRUE;
         } /* end else */
 
@@ -356,372 +361,36 @@ H5C_apply_candidate_list(H5F_t * f,
         } /* end if */
     } /* end for */
 
+#if H5C_DO_SANITY_CHECKS
+    m = 0;
+    n = 0;
+    for(i = 0; i < H5C_RING_NTYPES; i++) {
+        m += (int)entries_to_flush[i];
+        n += (int)entries_to_clear[i];
+    } /* end if */
+
+    HDassert((unsigned)m == total_entries_to_flush);
+    HDassert((unsigned)n == total_entries_to_clear);
+#endif /* H5C_DO_SANITY_CHECKS */
+
 #if H5C_APPLY_CANDIDATE_LIST__DEBUG
     HDfprintf(stdout, "%s:%d: num candidates/to clear/to flush = %u/%u/%u.\n", 
-              FUNC, mpi_rank, num_candidates, entries_to_clear,
-              entries_to_flush);
+              FUNC, mpi_rank, num_candidates, total_entries_to_clear,
+              total_entries_to_flush);
 #endif /* H5C_APPLY_CANDIDATE_LIST__DEBUG */
 
     /* We have now marked all the entries on the candidate list for 
      * either flush or clear -- now scan the LRU and the pinned list
-     * for these entries and do the deed.
+     * for these entries and do the deed.  Do this via a call to 
+     * H5C__flush_candidate_entries().
      *
      * Note that we are doing things in this round about manner so as
      * to preserve the order of the LRU list to the best of our ability.
      * If we don't do this, my experiments indicate that we will have a
      * noticably poorer hit ratio as a result.
      */
-
-#if H5C_APPLY_CANDIDATE_LIST__DEBUG
-    HDfprintf(stdout, "%s:%d: scanning LRU list. len = %d.\n", FUNC, mpi_rank,
-              (int)(cache_ptr->LRU_list_len));
-#endif /* H5C_APPLY_CANDIDATE_LIST__DEBUG */
-
-    /* ===================================================================== *
-     * Now scan the LRU and PEL lists, flushing or clearing entries as
-     * needed.
-     *
-     * The flush_me_last flag may dictate how or
-     * when some entries can be flushed, and should be addressed here.
-     * However, in their initial implementation, these flags only apply to the
-     * superblock, so there's only a relatively small change to this function
-     * to account for this one case where they come into play. If these flags
-     * are ever expanded upon, this function and the following flushing steps
-     * should be reworked to account for additional cases.
-     * ===================================================================== */
-
-    HDassert(entries_to_flush >= 0);
-
-    restart_scan = FALSE;
-    entries_examined = 0;
-    initial_list_len = cache_ptr->LRU_list_len;
-    entry_ptr = cache_ptr->LRU_tail_ptr;
-
-    /* Examine each entry in the LRU list */
-    while ( ( entry_ptr != NULL ) 
-            && 
-            ( entries_examined <= (entries_to_flush + 1) * initial_list_len ) 
-            &&
-            ( (entries_cleared + entries_flushed) < num_candidates ) ) {
-
-        if ( entry_ptr->prev != NULL )
-            prev_is_dirty = entry_ptr->prev->is_dirty;
-
-        /* If this process needs to clear this entry. */
-        if(entry_ptr->clear_on_unprotect) {
-
-            HDassert(entry_ptr->is_dirty);
-
-            next_ptr = entry_ptr->next; 
-            entry_ptr->clear_on_unprotect = FALSE;
-            clear_ptr = entry_ptr;
-            entry_ptr = entry_ptr->prev;
-            entries_cleared++;
-
-#if ( H5C_APPLY_CANDIDATE_LIST__DEBUG > 1 )
-    HDfprintf(stdout, "%s:%d: clearing 0x%llx.\n", FUNC, mpi_rank,
-              (long long)clear_ptr->addr);
-#endif /* H5C_APPLY_CANDIDATE_LIST__DEBUG */
-
-            /* reset entries_removed_counter and
-             * last_entry_removed_ptr prior to the call to
-             * H5C__flush_single_entry() so that we can spot
-             * unexpected removals of entries from the cache,
-             * and set the restart_scan flag if proceeding
-             * would be likely to cause us to scan an entry
-             * that is no longer in the cache.
-             *
-             * Note that as of this writing (April 2015) this 
-             * case cannot occur in the parallel case.  However 
-             * Quincey is making noises about changing this, hence 
-             * the insertion of this test.
-             *
-             * Note also that there is no test code to verify 
-             * that this code actually works (although similar code
-             * in the serial version exists and is tested).  
-             * 
-             * Implementing a test will likely require implementing
-             * flush op like facilities in the parallel tests.  At
-             * a guess this will not be terribly painful, but it 
-             * will take a bit of time.
-             */
-            cache_ptr->entries_removed_counter = 0;
-            cache_ptr->last_entry_removed_ptr  = NULL;
-
-            if(H5C__flush_single_entry(f, dxpl_id, clear_ptr, H5C__FLUSH_CLEAR_ONLY_FLAG | H5C__GENERATE_IMAGE_FLAG | H5C__DEL_FROM_SLIST_ON_DESTROY_FLAG) < 0)
-                HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "Can't clear entry.")
-
-            if((cache_ptr->entries_removed_counter > 1) ||
-                    (cache_ptr->last_entry_removed_ptr == entry_ptr))
-                restart_scan = TRUE;
-        } /* end if */
-
-        /* Else, if this process needs to flush this entry. */
-        else if (entry_ptr->flush_immediately) {
-
-	    HDassert(entry_ptr->is_dirty);
-
-            next_ptr = entry_ptr->next; 
-            entry_ptr->flush_immediately = FALSE;
-            flush_ptr = entry_ptr;
-            entry_ptr = entry_ptr->prev;
-            entries_flushed++;
-
-#if ( H5C_APPLY_CANDIDATE_LIST__DEBUG > 1 )
-    HDfprintf(stdout, "%s:%d: flushing 0x%llx.\n", FUNC, mpi_rank,
-              (long long)flush_ptr->addr);
-#endif /* H5C_APPLY_CANDIDATE_LIST__DEBUG */
-
-            /* reset entries_removed_counter and
-             * last_entry_removed_ptr prior to the call to
-             * H5C__flush_single_entry() so that we can spot
-             * unexpected removals of entries from the cache,
-             * and set the restart_scan flag if proceeding
-             * would be likely to cause us to scan an entry
-             * that is no longer in the cache.
-             *
-             * Note that as of this writing (April 2015) this 
-             * case cannot occur in the parallel case.  However 
-             * Quincey is making noises about changing this, hence 
-             * the insertion of this test.
-             *
-             * Note also that there is no test code to verify 
-             * that this code actually works (although similar code
-             * in the serial version exists and is tested).  
-             * 
-             * Implementing a test will likely require implementing
-             * flush op like facilities in the parallel tests.  At
-             * a guess this will not be terribly painful, but it 
-             * will take a bit of time.
-             */
-            cache_ptr->entries_removed_counter = 0;
-            cache_ptr->last_entry_removed_ptr  = NULL;
-
-            /* Add this entry to the list of entries to collectively write */
-            if(H5C__flush_single_entry(f, dxpl_id, flush_ptr, H5C__DEL_FROM_SLIST_ON_DESTROY_FLAG) < 0)
-                HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "Can't flush entry.")
-
-            if((cache_ptr->entries_removed_counter > 1) ||
-                    (cache_ptr->last_entry_removed_ptr == entry_ptr))
-                restart_scan = TRUE;
-        } /* end else-if */
-
-        /* Otherwise, no action to be taken on this entry. Grab the next. */
-        else {
-            entry_ptr = entry_ptr->prev;
-
-            if ( entry_ptr != NULL )
-                next_ptr = entry_ptr->next; 
-
-        } /* end else */
-
-        if ( ( entry_ptr != NULL ) 
-             &&
-             ( ( restart_scan )
-               ||
-               ( entry_ptr->is_dirty != prev_is_dirty )
-               ||
-               ( entry_ptr->next != next_ptr )
-               ||
-               ( entry_ptr->is_protected )
-               ||
-               ( entry_ptr->is_pinned ) 
-             ) 
-           ) {
-
-            /* something has happened to the LRU -- start over
-             * from the tail.
-             *
-             * Recall that this code should be un-reachable at present,
-             * as all the operations by entries on flush that could cause
-             * it to be reachable are disallowed in the parallel case at
-             * present.  Hence the following assertion which should be 
-             * removed if the above changes.
-             */
-
-	    HDassert( ! restart_scan );
-            HDassert( entry_ptr->is_dirty == prev_is_dirty );
-            HDassert( entry_ptr->next == next_ptr );
-            HDassert( ! entry_ptr->is_protected );
-            HDassert( ! entry_ptr->is_pinned );
-
-            HDassert(FALSE); /* see comment above */
-
-            restart_scan = FALSE;
-            entry_ptr = cache_ptr->LRU_tail_ptr;
-/* 
-	    H5C__UPDATE_STATS_FOR_LRU_SCAN_RESTART(cache_ptr)
-*/
-        }
-
-        entries_examined++;
-    } /* end while */
-
-#if H5C_APPLY_CANDIDATE_LIST__DEBUG
-    HDfprintf(stdout, "%s:%d: entries examined/cleared/flushed = %u/%u/%u.\n",
-              FUNC, mpi_rank, entries_examined,
-              entries_cleared, entries_flushed);
-#endif /* H5C_APPLY_CANDIDATE_LIST__DEBUG */
-
-    /* It is also possible that some of the cleared entries are on the
-     * pinned list.  Must scan that also.
-     *
-     * WARNING:
-     *
-     *	As we now allow unpinning, and removal of other entries as a side 
-     *  effect of flushing an entry, it is possible that the next entry
-     *  in a PEL scan could either be no longer pinned, or no longer in
-     *  the cache by the time we get to it.
-     *
-     *  At present, this is not possible in this case, as we disallow such
-     *  operations in the parallel version of the library.  However, Quincey
-     *  has been making noises about relaxing this.  If and when he does,
-     *  we have a potential problem here.
-     *
-     *  The same issue exists in the serial cache, and there are tests 
-     *  to detect this problem when it occurs, and adjust to it.  As seen
-     *  above in the LRU scan, I have ported such tests to the parallel 
-     *  code where a close cognate exists in the serial code.  
-     *
-     *  I haven't done so here, as there are no PEL scans where the problem
-     *  can occur in the serial code.  Needless to say, this will have to 
-     *  be repaired if the constraints on pre_serialize and serialize 
-     *  callbacks are relaxed in the parallel version of the metadata cache.
-     *
-     *						JRM -- 4/1/15
-     */
-
-#if H5C_APPLY_CANDIDATE_LIST__DEBUG
-    HDfprintf(stdout, "%s:%d: scanning pinned entry list. len = %d\n",
-             FUNC, mpi_rank, (int)(cache_ptr->pel_len));
-#endif /* H5C_APPLY_CANDIDATE_LIST__DEBUG */
-
-    entry_ptr = cache_ptr->pel_head_ptr;
-    while((entry_ptr != NULL) &&
-          ((entries_cleared + entries_flushed + entries_delayed)
-            < num_candidates)) {
-
-        /* If entry is marked for flush or for clear */
-        if((entry_ptr->clear_on_unprotect||entry_ptr->flush_immediately)) {
-
-            /* If this entry needs to be flushed last */
-            if (entry_ptr->flush_me_last) {
-
-                /* At this time, only the superblock supports being
-                   flushed last. Conveniently, it also happens to be the only
-                   entry that supports being flushed collectively, as well. Also
-                   conveniently, it's always pinned, so we only need to check
-                   for it while scanning the PEL here. Finally, it's never
-                   included in a candidate list that excludes other dirty
-                   entries in a cache, so we can handle this relatively simple
-                   case here.
-                   
-                   For now, this function asserts this and saves the entry
-                   to flush it after scanning the rest of the PEL list.
-
-                   If there are ever more entries that either need to be
-                   flushed last and/or flushed collectively, this whole routine
-                   will need to be reworked to handle all additional cases. As
-                   it is the simple case of a single pinned entry needing
-                   flushed last and collectively is just a minor addition to
-                   this routine, but signficantly buffing up the usage of
-                   flush_me_last will require a more
-                   intense rework of this function and potentially the function
-                   of candidate lists as a whole. */
-
-                entries_to_flush_or_clear_last++;
-                entries_to_flush_collectively++;
-                HDassert(entries_to_flush_or_clear_last == 1);
-                HDassert(entries_to_flush_collectively == 1);
-
-                /* Delay the entry. It will be flushed later. */
-                delayed_ptr = entry_ptr;
-                entries_delayed++;
-                HDassert(entries_delayed == 1);
-
-            } /* end if */
-
-            /* Else, this process needs to clear this entry. */
-            else if (entry_ptr->clear_on_unprotect) {
-                HDassert(!entry_ptr->flush_immediately);
-                entry_ptr->clear_on_unprotect = FALSE;
-                clear_ptr = entry_ptr;
-                entry_ptr = entry_ptr->next;
-                entries_cleared++;
-
-#if ( H5C_APPLY_CANDIDATE_LIST__DEBUG > 1 )
-                HDfprintf(stdout, "%s:%d: clearing 0x%llx.\n", FUNC, mpi_rank,
-                          (long long)clear_ptr->addr);
-#endif /* H5C_APPLY_CANDIDATE_LIST__DEBUG */
-
-                if(H5C__flush_single_entry(f, dxpl_id, clear_ptr, H5C__FLUSH_CLEAR_ONLY_FLAG | H5C__GENERATE_IMAGE_FLAG | H5C__DEL_FROM_SLIST_ON_DESTROY_FLAG) < 0)
-                    HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "Can't clear entry.")
-            } /* end else-if */
-
-            /* Else, if this process needs to independently flush this entry. */
-            else if (entry_ptr->flush_immediately) {
-                entry_ptr->flush_immediately = FALSE;
-                flush_ptr = entry_ptr;
-                entry_ptr = entry_ptr->next;
-                entries_flushed++;
-
-#if ( H5C_APPLY_CANDIDATE_LIST__DEBUG > 1 )
-                HDfprintf(stdout, "%s:%d: flushing 0x%llx.\n", FUNC, mpi_rank,
-                      (long long)flush_ptr->addr);
-#endif /* H5C_APPLY_CANDIDATE_LIST__DEBUG */
-
-                /* Add this entry to the list of entries to collectively write */
-                if(H5C__flush_single_entry(f, dxpl_id, flush_ptr, H5C__DEL_FROM_SLIST_ON_DESTROY_FLAG) < 0)
-                    HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "Can't clear entry.")
-            } /* end else-if */
-        } /* end if */
-
-        /* Otherwise, this entry is not marked for flush or clear. Grab the next. */
-        else {
-            entry_ptr = entry_ptr->next;
-        } /* end else */
-
-    } /* end while */
-
-#if H5C_APPLY_CANDIDATE_LIST__DEBUG
-    HDfprintf(stdout,
-              "%s:%d: pel entries examined/cleared/flushed = %u/%u/%u.\n",
-              FUNC, mpi_rank, entries_examined,
-              entries_cleared, entries_flushed);
-    HDfprintf(stdout, "%s:%d: done.\n", FUNC, mpi_rank);
-
-    HDfsync(stdout);
-#endif /* H5C_APPLY_CANDIDATE_LIST__DEBUG */
-
-    /* ====================================================================== *
-     * Now, handle all delayed entries.                                       *
-     *                                                                        *
-     * This can *only* be the superblock at this time, so it's relatively     *
-     * easy to deal with. We're collectively flushing the entry saved from    *
-     * above. This will need to be handled differently if there are ever more *
-     * than one entry needing this special treatment.)                        *
-     * ====================================================================== */
-
-    if (delayed_ptr) {
-
-        if (delayed_ptr->clear_on_unprotect) {
-            if(H5C__flush_single_entry(f, dxpl_id, delayed_ptr, H5C__FLUSH_CLEAR_ONLY_FLAG | H5C__GENERATE_IMAGE_FLAG) < 0)
-                HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "Can't flush entry.")
-
-            entry_ptr->clear_on_unprotect = FALSE;
-            entries_cleared++;
-        } else if (delayed_ptr->flush_immediately) {
-            /* Add this entry to the list of entries to collectively write */
-            if(H5C__flush_single_entry(f, dxpl_id, delayed_ptr, H5C__DEL_FROM_SLIST_ON_DESTROY_FLAG) < 0)
-                HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "Can't flush entry collectively.")
-
-            entry_ptr->flush_immediately = FALSE;
-            entries_flushed++;
-        } /* end if */
-
-        entries_flushed_collectively++;
-        entries_flushed_or_cleared_last++;
-    } /* end if */
+     if(H5C__flush_candidate_entries(f, dxpl_id, entries_to_flush, entries_to_clear) < 0)
+         HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "flush candidates failed")
 
     /* If we've deferred writing to do it collectively, take care of that now */
     if(f->coll_md_write) {
@@ -733,21 +402,6 @@ H5C_apply_candidate_list(H5F_t * f,
             HGOTO_ERROR(H5E_CACHE, H5E_WRITEERROR, FAIL, "can't write metadata collectively")
     } /* end if */
 
-    /* ====================================================================== *
-     * Finished flushing everything.                                          *
-     * ====================================================================== */
-
-    HDassert((entries_flushed == entries_to_flush));
-    HDassert((entries_cleared == entries_to_clear));
-    HDassert((entries_flushed_or_cleared_last == entries_to_flush_or_clear_last));
-    HDassert((entries_flushed_collectively == entries_to_flush_collectively));
-    
-    if((entries_flushed != entries_to_flush) || 
-           (entries_cleared != entries_to_clear) ||
-           (entries_flushed_or_cleared_last != entries_to_flush_or_clear_last) ||
-           (entries_flushed_collectively != entries_to_flush_collectively))
-        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "entry count mismatch")
-
 done:
     if(candidate_assignment_table != NULL)
         candidate_assignment_table = (int *)H5MM_xfree((void *)candidate_assignment_table);
@@ -998,11 +652,13 @@ H5C_mark_entries_as_clean(H5F_t *  f,
 {
     H5C_t *             cache_ptr;
     unsigned		entries_cleared;
+    unsigned            pinned_entries_cleared;
+    hbool_t             progress;
     unsigned		entries_examined;
     unsigned		initial_list_len;
     haddr_t		addr;
-#if H5C_DO_SANITY_CHECKS
     unsigned		pinned_entries_marked = 0;
+#if H5C_DO_SANITY_CHECKS
     unsigned		protected_entries_marked = 0;
     unsigned		other_entries_marked = 0;
     haddr_t		last_addr;
@@ -1086,19 +742,13 @@ H5C_mark_entries_as_clean(H5F_t *  f,
             } /* end if */
 
             entry_ptr->clear_on_unprotect = TRUE;
+	    if(entry_ptr->is_pinned)
+		pinned_entries_marked++;
 #if H5C_DO_SANITY_CHECKS
-	    if ( entry_ptr->is_protected ) {
-
+	    else if(entry_ptr->is_protected)
 		protected_entries_marked++;
-
-	    } else if ( entry_ptr->is_pinned ) {
-
-		pinned_entries_marked++;
-
-	    } else {
-
+	    else
 		other_entries_marked++;
-	    }
 #endif /* H5C_DO_SANITY_CHECKS */
         }
     }
@@ -1140,7 +790,8 @@ H5C_mark_entries_as_clean(H5F_t *  f,
             entry_ptr = entry_ptr->prev;
             entries_cleared++;
 
-            if(H5C__flush_single_entry(f, dxpl_id, clear_ptr, H5C__FLUSH_CLEAR_ONLY_FLAG | H5C__DEL_FROM_SLIST_ON_DESTROY_FLAG) < 0)
+            if(H5C__flush_single_entry(f, dxpl_id, clear_ptr,
+                    (H5C__FLUSH_CLEAR_ONLY_FLAG | H5C__GENERATE_IMAGE_FLAG | H5C__UPDATE_PAGE_BUFFER_FLAG)) < 0)
                 HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "can't clear entry")
         } /* end if */
         else
@@ -1155,19 +806,27 @@ H5C_mark_entries_as_clean(H5F_t *  f,
     /* It is also possible that some of the cleared entries are on the
      * pinned list.  Must scan that also.
      */
-    entry_ptr = cache_ptr->pel_head_ptr;
-    while(entry_ptr != NULL) {
-        if(entry_ptr->clear_on_unprotect) {
-            entry_ptr->clear_on_unprotect = FALSE;
-            clear_ptr = entry_ptr;
-            entry_ptr = entry_ptr->next;
-            entries_cleared++;
+    pinned_entries_cleared = 0;
+    progress = TRUE;
+    while((pinned_entries_cleared < pinned_entries_marked) && progress) {
+        progress = FALSE;
+        entry_ptr = cache_ptr->pel_head_ptr;
+        while(entry_ptr != NULL) {
+            if(entry_ptr->clear_on_unprotect && entry_ptr->flush_dep_ndirty_children == 0) {
+                entry_ptr->clear_on_unprotect = FALSE;
+                clear_ptr = entry_ptr;
+                entry_ptr = entry_ptr->next;
+                entries_cleared++;
+                pinned_entries_cleared++;
+                progress = TRUE;
 
-            if(H5C__flush_single_entry(f, dxpl_id, clear_ptr, H5C__FLUSH_CLEAR_ONLY_FLAG | H5C__DEL_FROM_SLIST_ON_DESTROY_FLAG) < 0)
-                HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "Can't clear entry")
-        } /* end if */
-        else
-            entry_ptr = entry_ptr->next;
+                if(H5C__flush_single_entry(f, dxpl_id, clear_ptr, 
+                        (H5C__FLUSH_CLEAR_ONLY_FLAG | H5C__GENERATE_IMAGE_FLAG | H5C__UPDATE_PAGE_BUFFER_FLAG)) < 0)
+                    HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "can't clear entry")
+            } /* end if */
+            else
+                entry_ptr = entry_ptr->next;
+        }  /* end while */
     } /* end while */
 
 #if H5C_DO_SANITY_CHECKS
@@ -1297,7 +956,6 @@ H5C__collective_write(H5F_t *f, hid_t dxpl_id)
 
     /* Get number of entries in collective write list */
     count = (int)H5SL_count(cache_ptr->coll_write_list);
-
     if(count > 0) {
         H5FD_mpio_xfer_t    xfer_mode = H5FD_MPIO_COLLECTIVE;
         H5SL_node_t         *node;
@@ -1410,4 +1068,511 @@ done:
 
     FUNC_LEAVE_NOAPI(ret_value);
 } /* end H5C__collective_write() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__flush_candidate_entries
+ *
+ * Purpose:	Flush or clear (as indicated) the candidate entries that
+ *              have been marked in the metadata cache.  In so doing,
+ *              observe rings and flush dependencies.
+ *
+ *              Note that this function presumes that:
+ *
+ *              1) no candidate entries are protected,
+ *
+ *              2) all candidate entries are dirty, and
+ *
+ *              3) if a candidate entry has a dirty flush dependency
+ *                 child, that child is also a candidate entry.
+ *
+ *              The function will fail if any of these preconditions are
+ *              not met.
+ *
+ *              Candidate entries are marked by setting either the
+ *              flush_immediately or the clear_on_unprotect flags in the
+ *              cache entry (but not both).  Entries marked flush_immediately
+ *              will be flushed, those marked clear_on_unprotect will be
+ *              cleared.
+ *
+ *              Note that this function is a modified version of
+ *              H5C_flush_cache() -- any changes there may need to be
+ *              reflected here and vise versa.
+ *
+ * Return:      Non-negative on success/Negative on failure.
+ *
+ * Programmer:  John Mainzer
+ *		2/10/17
+ *
+ * Changes:	None.
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__flush_candidate_entries(H5F_t *f, hid_t dxpl_id,
+    unsigned entries_to_flush[H5C_RING_NTYPES],
+    unsigned entries_to_clear[H5C_RING_NTYPES])
+{
+#if H5C_DO_SANITY_CHECKS
+    int			i;
+    uint32_t		index_len = 0;
+    size_t		index_size = (size_t)0;
+    size_t		clean_index_size = (size_t)0;
+    size_t		dirty_index_size = (size_t)0;
+    size_t		slist_size = (size_t)0;
+    uint32_t		slist_len = 0;
+#endif /* H5C_DO_SANITY_CHECKS */
+    H5C_ring_t		ring;
+    H5C_t             * cache_ptr;
+    herr_t		ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    HDassert(f);
+    HDassert(f->shared);
+
+    cache_ptr = f->shared->cache;
+
+    HDassert(cache_ptr);
+    HDassert(cache_ptr->magic == H5C__H5C_T_MAGIC);
+    HDassert(cache_ptr->slist_ptr);
+
+    HDassert(entries_to_flush[H5C_RING_UNDEFINED] == 0);
+    HDassert(entries_to_clear[H5C_RING_UNDEFINED] == 0);
+
+#if H5C_DO_SANITY_CHECKS
+    HDassert(cache_ptr->index_ring_len[H5C_RING_UNDEFINED] == 0);
+    HDassert(cache_ptr->index_ring_size[H5C_RING_UNDEFINED] == (size_t)0);
+    HDassert(cache_ptr->clean_index_ring_size[H5C_RING_UNDEFINED] == (size_t)0);
+    HDassert(cache_ptr->dirty_index_ring_size[H5C_RING_UNDEFINED] == (size_t)0);
+    HDassert(cache_ptr->slist_ring_len[H5C_RING_UNDEFINED] == 0);
+    HDassert(cache_ptr->slist_ring_size[H5C_RING_UNDEFINED] == (size_t)0);
+
+    for(i = H5C_RING_USER; i < H5C_RING_NTYPES; i++) {
+        index_len += cache_ptr->index_ring_len[i];
+        index_size += cache_ptr->index_ring_size[i];
+        clean_index_size += cache_ptr->clean_index_ring_size[i];
+        dirty_index_size += cache_ptr->dirty_index_ring_size[i];
+
+	slist_len += cache_ptr->slist_ring_len[i];
+        slist_size += cache_ptr->slist_ring_size[i];
+    } /* end for */
+
+    HDassert(cache_ptr->index_len == index_len);
+    HDassert(cache_ptr->index_size == index_size);
+    HDassert(cache_ptr->clean_index_size == clean_index_size);
+    HDassert(cache_ptr->dirty_index_size == dirty_index_size);
+    HDassert(cache_ptr->slist_len == slist_len);
+    HDassert(cache_ptr->slist_size == slist_size);
+#endif /* H5C_DO_SANITY_CHECKS */
+
+#if H5C_DO_EXTREME_SANITY_CHECKS
+    if(H5C_validate_protected_entry_list(cache_ptr) < 0
+            || H5C_validate_pinned_entry_list(cache_ptr) < 0
+            || H5C_validate_lru_list(cache_ptr) < 0)
+        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "an extreme sanity check failed on entry")
+#endif /* H5C_DO_EXTREME_SANITY_CHECKS */
+
+    cache_ptr->flush_in_progress = TRUE;
+
+    /* flush each ring, starting from the outermost ring and
+     * working inward.
+     */
+    ring = H5C_RING_USER;
+    while(ring < H5C_RING_NTYPES) {
+        if(H5C__flush_candidates_in_ring(f, dxpl_id, ring, entries_to_flush[ring], entries_to_clear[ring]) < 0)
+            HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "flush candidates in ring failed")
+
+        ring++;
+    }  /* end while */
+
+done:
+    cache_ptr->flush_in_progress = FALSE;
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__flush_candidate_entries() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5C__flush_candidates_in_ring
+ *
+ * Purpose:	Flush or clear (as indicated) the candidate entries
+ *              contained in the specified cache and ring.  All candidate
+ *              entries in rings outside the specified ring must have been
+ *              flushed (or cleared) on entry.
+ *
+ *              Note that this function presumes that:
+ *
+ *              1) no candidate entries are protected,
+ *
+ *              2) all candidate entries are dirty, and
+ *
+ *              3) if a candidate entry has a dirty flush dependency
+ *                 child, that child is also a candidate entry.
+ *
+ *              The function will fail if any of these preconditions are
+ *              not met.
+ *
+ *              Candidate entries are marked by setting either the
+ *              flush_immediately or the clear_on_unprotect flags in the
+ *              cache entry (but not both).  Entries marked flush_immediately
+ *              will be flushed, those marked clear_on_unprotect will be
+ *              cleared.
+ *
+ *              Candidate entries residing in the LRU must be flushed
+ *              (or cleared) in LRU order to avoid performance issues.
+ *
+ * Return:      Non-negative on success/Negative on failure.
+ *
+ * Programmer:  John Mainzer
+ *		2/10/17
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5C__flush_candidates_in_ring(H5F_t *f, hid_t dxpl_id, H5C_ring_t ring,
+    unsigned  entries_to_flush, unsigned entries_to_clear)
+{
+    H5C_t   * cache_ptr;
+    hbool_t   progress;
+    hbool_t   restart_scan = FALSE;
+    unsigned  entries_flushed = 0;
+    unsigned  entries_cleared = 0;
+#if H5C_DO_SANITY_CHECKS
+    unsigned  init_index_len;
+#endif /* H5C_DO_SANITY_CHECKS */
+    unsigned  clear_flags = H5C__FLUSH_CLEAR_ONLY_FLAG |
+                            H5C__GENERATE_IMAGE_FLAG |
+                            H5C__UPDATE_PAGE_BUFFER_FLAG;
+    unsigned  flush_flags = H5C__NO_FLAGS_SET;
+    unsigned  op_flags;
+    H5C_cache_entry_t *op_ptr;
+    H5C_cache_entry_t *entry_ptr;
+    herr_t    ret_value = SUCCEED;
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(f);
+    HDassert(f->shared);
+    cache_ptr = f->shared->cache;
+    HDassert(cache_ptr);
+    HDassert(cache_ptr->magic == H5C__H5C_T_MAGIC);
+    HDassert(cache_ptr->slist_ptr);
+    HDassert(ring > H5C_RING_UNDEFINED);
+    HDassert(ring < H5C_RING_NTYPES);
+
+#if H5C_DO_EXTREME_SANITY_CHECKS
+    if((H5C_validate_protected_entry_list(cache_ptr) < 0) ||
+            (H5C_validate_pinned_entry_list(cache_ptr) < 0) ||
+            (H5C_validate_lru_list(cache_ptr) < 0))
+        HGOTO_ERROR(H5E_CACHE, H5E_SYSTEM, FAIL, "an extreme sanity check failed on entry")
+#endif /* H5C_DO_EXTREME_SANITY_CHECKS */
+
+#if H5C_DO_SANITY_CHECKS
+    /* index len should not change */
+    init_index_len = cache_ptr->index_len;
+#endif /* H5C_DO_SANITY_CHECKS */
+
+    /* Examine entries in the LRU list, and flush or clear all entries
+     * so marked in the target ring.
+     *
+     * With the current implementation of flush dependencies, no entry
+     * in the LRU can have flush dependency children -- thus one pass
+     * through the LRU will be sufficient.
+     *
+     * It is possible that this will change -- hence the assertion.
+     */
+    restart_scan = FALSE;
+    entry_ptr = cache_ptr->LRU_tail_ptr;
+    while(((entries_flushed < entries_to_flush) || (entries_cleared < entries_to_clear))
+            && (entry_ptr != NULL)) {
+        hbool_t prev_is_dirty = FALSE;
+        H5C_cache_entry_t *next_ptr;
+
+        /* Entries in the LRU must not have flush dependency children */
+        HDassert(entry_ptr->flush_dep_nchildren == 0);
+
+        /* Remember dirty state of entry to advance to */
+        if(entry_ptr->prev != NULL)
+            prev_is_dirty = entry_ptr->prev->is_dirty;
+
+        /* If the entry is in the ring */
+        if(entry_ptr->ring == ring) {
+            /* If this process needs to clear this entry. */
+            if(entry_ptr->clear_on_unprotect) {
+                HDassert(entry_ptr->is_dirty);
+
+                /* Set entry and flags for operation */
+                op_ptr = entry_ptr;
+                op_flags = clear_flags;
+
+                /* Set next entry appropriately */
+                next_ptr = entry_ptr->next;
+
+                /* Reset entry flag */
+                entry_ptr->clear_on_unprotect = FALSE;
+                entries_cleared++;
+            } /* end if */
+            else if(entry_ptr->flush_immediately) {
+                HDassert(entry_ptr->is_dirty);
+
+                /* Set entry and flags for operation */
+                op_ptr = entry_ptr;
+                op_flags = flush_flags;
+
+                /* Set next entry appropriately */
+                next_ptr = entry_ptr->next;
+
+                /* Reset entry flag */
+                entry_ptr->flush_immediately = FALSE;
+                entries_flushed++;
+            } /* end else-if */
+            else {
+                /* No operation for this entry */
+                op_ptr = NULL;
+
+                /* Set next entry appropriately */
+                next_ptr = entry_ptr;
+            } /* end else */
+
+            /* Advance to next entry */
+            entry_ptr = entry_ptr->prev;
+
+            /* Check for operation */
+            if(op_ptr) {
+                /* reset entries_removed_counter and
+                 * last_entry_removed_ptr prior to the call to
+                 * H5C__flush_single_entry() so that we can spot
+                 * unexpected removals of entries from the cache,
+                 * and set the restart_scan flag if proceeding
+                 * would be likely to cause us to scan an entry
+                 * that is no longer in the cache.
+                 *
+                 * Note that as of this writing, this
+                 * case cannot occur in the parallel case.
+                 *
+                 * Note also that there is no test code to verify
+                 * that this code actually works (although similar code
+                 * in the serial version exists and is tested).
+                 */
+                cache_ptr->entries_removed_counter = 0;
+                cache_ptr->last_entry_removed_ptr  = NULL;
+
+                if(H5C__flush_single_entry(f, dxpl_id, op_ptr, op_flags) < 0)
+                    HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "can't flush entry")
+
+                if(cache_ptr->entries_removed_counter != 0
+                        || cache_ptr->last_entry_removed_ptr != NULL)
+                    restart_scan = TRUE;
+            } /* end if */
+        } /* end if */
+        else {
+            /* Remember "next" pointer (after advancing entries) */
+            next_ptr = entry_ptr;
+
+            /* Advance to next entry */
+            entry_ptr = entry_ptr->prev;
+        } /* end else */
+
+        /* Check for restarts, etc. */
+        if((entry_ptr != NULL) &&
+             (restart_scan || (entry_ptr->is_dirty != prev_is_dirty)
+                || (entry_ptr->next != next_ptr) || entry_ptr->is_protected
+                || entry_ptr->is_pinned)) {
+
+            /* Something has happened to the LRU -- start over
+             * from the tail.
+             *
+             * Recall that this code should be un-reachable at present,
+             * as all the operations by entries on flush that could cause
+             * it to be reachable are disallowed in the parallel case at
+             * present.  Hence the following assertion which should be
+             * removed if the above changes.
+             */
+            HDassert(!restart_scan);
+            HDassert(entry_ptr->is_dirty == prev_is_dirty);
+            HDassert(entry_ptr->next == next_ptr);
+            HDassert(!entry_ptr->is_protected);
+            HDassert(!entry_ptr->is_pinned);
+
+            HDassert(FALSE); /* see comment above */
+
+            restart_scan = FALSE;
+            entry_ptr = cache_ptr->LRU_tail_ptr;
+
+            H5C__UPDATE_STATS_FOR_LRU_SCAN_RESTART(cache_ptr)
+        } /* end if */
+    } /* end while */
+
+    /* It is also possible that some of the cleared entries are on the
+     * pinned list.  Must scan that also.
+     *
+     * Observe that in the case of the pinned entry list, most of the
+     * entries will have flush dependency children.  As entries with
+     * flush dependency children may not be flushed until all of their
+     * children are clean, multiple passes throguh the pinned entry list
+     * may be required.
+     *
+     * WARNING:
+     *
+     *  As we now allow unpinning, and removal of other entries as a side
+     *  effect of flushing an entry, it is possible that the next entry
+     *  in a PEL scan could either be no longer pinned, or no longer in
+     *  the cache by the time we get to it.
+     *
+     *  At present, this should not be possible in this case, as we disallow
+     *  such operations in the parallel version of the library.  However,
+     *  this may change, and to that end, I have included code to detect
+     *  such changes and cause this function to fail if they are detected.
+     */
+    progress = TRUE;
+    while(progress && ((entries_flushed < entries_to_flush) || (entries_cleared < entries_to_clear))) {
+        progress = FALSE;
+        entry_ptr = cache_ptr->pel_head_ptr;
+        while((entry_ptr != NULL) &&
+                ((entries_flushed < entries_to_flush) || (entries_cleared < entries_to_clear))) {
+            H5C_cache_entry_t *prev_ptr;
+            hbool_t next_is_dirty = FALSE;
+
+            HDassert(entry_ptr->is_pinned);
+
+            /* Remember dirty state of entry to advance to */
+            if(entry_ptr->next != NULL)
+                next_is_dirty = entry_ptr->next->is_dirty;
+
+            if(entry_ptr->ring == ring && entry_ptr->flush_dep_ndirty_children == 0) {
+                if(entry_ptr->clear_on_unprotect) {
+                    HDassert(entry_ptr->is_dirty);
+
+                    /* Set entry and flags for operation */
+                    op_ptr = entry_ptr;
+                    op_flags = clear_flags;
+
+                    /* Reset entry flag */
+                    entry_ptr->clear_on_unprotect = FALSE;
+                    entries_cleared++;
+                    progress = TRUE;
+                } /* end if */
+                else if(entry_ptr->flush_immediately) {
+                    HDassert(entry_ptr->is_dirty);
+
+                    /* Set entry and flags for operation */
+                    op_ptr = entry_ptr;
+                    op_flags = flush_flags;
+
+                    /* Reset entry flag */
+                    entry_ptr->flush_immediately = FALSE;
+                    entries_flushed++;
+                    progress = TRUE;
+                } /* end else-if */
+                else
+                    /* No operation for this entry */
+                    op_ptr = NULL;
+
+                /* Check for operation */
+                if(op_ptr) {
+                    /* reset entries_removed_counter and
+                     * last_entry_removed_ptr prior to the call to
+                     * H5C__flush_single_entry() so that we can spot
+                     * unexpected removals of entries from the cache,
+                     * and set the restart_scan flag if proceeding
+                     * would be likely to cause us to scan an entry
+                     * that is no longer in the cache.
+                     *
+                     * Note that as of this writing,  this
+                     * case cannot occur in the parallel case.
+                     *
+                     * Note also that there is no test code to verify
+                     * that this code actually works (although similar code
+                     * in the serial version exists and is tested).
+                     */
+                    cache_ptr->entries_removed_counter = 0;
+                    cache_ptr->last_entry_removed_ptr  = NULL;
+
+                    /* Add this entry to the list of entries to collectively write
+                     *
+                     * This comment is misleading -- the entry will be added to the
+                     * collective write list only if said list exists.
+                     *
+                     *                                    JRM -- 2/9/17
+                     */
+                    if(H5C__flush_single_entry(f, dxpl_id, op_ptr, op_flags) < 0)
+                        HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "can't flush entry")
+
+                    if(cache_ptr->entries_removed_counter != 0
+                            || cache_ptr->last_entry_removed_ptr != NULL)
+                        restart_scan = TRUE;
+                } /* end if */
+            } /* end if */
+
+            /* Remember "previous" pointer (after advancing entries) */
+            prev_ptr = entry_ptr;
+
+            /* Advance to next entry */
+            entry_ptr = entry_ptr->next;
+
+            /* Check for restarts, etc. */
+            if((entry_ptr != NULL) &&
+                    (restart_scan || (entry_ptr->is_dirty != next_is_dirty)
+                        || (entry_ptr->prev != prev_ptr) || entry_ptr->is_protected
+                        || !entry_ptr->is_pinned)) {
+                /* Something has happened to the pinned entry list -- start
+                 * over from the head.
+                 *
+                 * Recall that this code should be un-reachable at present,
+                 * as all the operations by entries on flush that could cause
+                 * it to be reachable are disallowed in the parallel case at
+                 * present.  Hence the following assertion which should be
+                 * removed if the above changes.
+                 */
+
+                HDassert(!restart_scan);
+                HDassert(entry_ptr->is_dirty == next_is_dirty);
+                HDassert(entry_ptr->prev == prev_ptr);
+                HDassert(!entry_ptr->is_protected);
+                HDassert(entry_ptr->is_pinned);
+
+                HDassert(FALSE); /* see comment above */
+
+                restart_scan = FALSE;
+
+                entry_ptr = cache_ptr->pel_head_ptr;
+
+                /* we don't keeps stats for pinned entry list scan
+                 * restarts.  If this code ever becomes reachable,
+                 * define the necessary field, and implement the
+                 * the following macro:
+                 *
+                 * H5C__UPDATE_STATS_FOR_PEL_SCAN_RESTART(cache_ptr)
+                 */
+            } /* end if */
+        } /* end while ( ( entry_ptr != NULL ) &&
+           *             ( ( entries_flushed > entries_to_flush ) ||
+           *               ( entries_cleared > entries_to_clear ) ) )
+           */
+    } /* end while ( ( ( entries_flushed > entries_to_flush ) ||
+       *               ( entries_cleared > entries_to_clear ) ) &&
+       *             ( progress ) )
+       */
+
+#if H5C_DO_SANITY_CHECKS
+    HDassert(init_index_len == cache_ptr->index_len);
+#endif /* H5C_DO_SANITY_CHECKS */
+
+    if(entries_flushed != entries_to_flush || entries_cleared != entries_to_clear) {
+        entry_ptr = cache_ptr->il_head;
+        while(entry_ptr != NULL) {
+            HDassert(!entry_ptr->clear_on_unprotect || (entry_ptr->ring > ring));
+            HDassert(!entry_ptr->flush_immediately || (entry_ptr->ring > ring));
+            entry_ptr = entry_ptr->il_next;
+        } /* end while */
+
+        HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "can't flush/clear all entries")
+    } /* end if */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5C__flush_candidates_in_ring() */
 #endif /* H5_HAVE_PARALLEL */
+
diff --git a/src/H5Cpkg.h b/src/H5Cpkg.h
index 5b923e9..69e8145 100644
--- a/src/H5Cpkg.h
+++ b/src/H5Cpkg.h
@@ -4104,6 +4104,23 @@ typedef struct H5C_tag_info_t {
  *		of changes to the file driver info superblock extension
  *		management code needed to support rings.
  *
+ * msic_in_progress: As the metadata cache has become re-entrant, and as
+ *              the free space manager code has become more tightly 
+ *              integrated with the metadata cache, it is possible that 
+ *              a call to H5C_insert_entry() may trigger a call to 
+ *              H5C_make_space_in_cache(), which, via H5C__flush_single_entry()
+ *              and client callbacks, may trigger an infinite regression
+ *              of calls to H5C_make_space_in_cache().
+ *
+ *              The msic_in_progress boolean flag is used to detect this,
+ *              and prevent the infinite regression that would otherwise
+ *              occur.
+ *
+ *              Note that this is issue is not hypothetical -- this field 
+ *              was added 2/16/17 to address this issue when it was 
+ *              exposed by modifications to test/fheap.c to cause it to 
+ *              use paged allocation.
+ *
  * resize_ctl:	Instance of H5C_auto_size_ctl_t containing configuration
  * 		data for automatic cache resizing.
  *
@@ -4500,12 +4517,22 @@ typedef struct H5C_tag_info_t {
  * total_entries_skipped_in_msic: Number of clean entries skipped while
  *              enforcing the min_clean_fraction in H5C__make_space_in_cache().
  *
+ * total_dirty_pf_entries_skipped_in_msic: Number of dirty prefetched entries
+ *              skipped in H5C__make_space_in_cache().  Note that this can 
+ *              only occur when a file is opened R/O with a cache image
+ *              containing dirty entries.
+ *
  * total_entries_scanned_in_msic: Number of clean entries skipped while
  *              enforcing the min_clean_fraction in H5C__make_space_in_cache().
  *
  * max_entries_skipped_in_msic: Maximum number of clean entries skipped
  *              in any one call to H5C__make_space_in_cache().
  *
+ * max_dirty_pf_entries_skipped_in_msic: Maximum number of dirty prefetched
+ *              entries skipped in any one call to H5C__make_space_in_cache().
+ *              Note that this can only occur when the file is opened 
+ *              R/O with a cache image containing dirty entries.
+ *
  * max_entries_scanned_in_msic: Maximum number of entries scanned over
  *              in any one call to H5C__make_space_in_cache().
  *
@@ -4733,6 +4760,7 @@ struct H5C_t {
     hbool_t			cache_full;
     hbool_t			size_decreased;
     hbool_t			resize_in_progress;
+    hbool_t			msic_in_progress;
     H5C_auto_size_ctl_t		resize_ctl;
 
     /* Fields for epoch markers used in automatic cache size adjustment */
@@ -4822,8 +4850,10 @@ struct H5C_t {
     /* Fields for tracking 'make space in cache' (msic) operations */
     int64_t                     calls_to_msic;
     int64_t                     total_entries_skipped_in_msic;
+    int64_t                     total_dirty_pf_entries_skipped_in_msic;
     int64_t                     total_entries_scanned_in_msic;
     int32_t                     max_entries_skipped_in_msic;
+    int32_t                     max_dirty_pf_entries_skipped_in_msic;
     int32_t                     max_entries_scanned_in_msic;
     int64_t                     entries_scanned_to_make_space;
  
@@ -4871,7 +4901,8 @@ typedef int (*H5C_tag_iter_cb_t)(H5C_cache_entry_t *entry, void *ctx);
 /******************************/
 /* Package Private Prototypes */
 /******************************/
-H5_DLL herr_t H5C__prep_image_for_file_close(H5F_t *f, hid_t dxpl_id);
+H5_DLL herr_t H5C__prep_image_for_file_close(H5F_t *f, hid_t dxpl_id,
+    hbool_t *image_generated);
 H5_DLL herr_t H5C__deserialize_prefetched_entry(H5F_t *f, hid_t dxpl_id,
     H5C_t * cache_ptr, H5C_cache_entry_t** entry_ptr_ptr, 
     const H5C_class_t * type, haddr_t addr, void * udata);
diff --git a/src/H5Cprivate.h b/src/H5Cprivate.h
index 28eacf2..539dece 100644
--- a/src/H5Cprivate.h
+++ b/src/H5Cprivate.h
@@ -185,6 +185,7 @@
  *      H5C__TAKE_OWNERSHIP_FLAG
  *      H5C__DEL_FROM_SLIST_ON_DESTROY_FLAG
  *      H5C__GENERATE_IMAGE_FLAG
+ *      H5C__UPDATE_PAGE_BUFFER_FLAG
  */
 #define H5C__NO_FLAGS_SET			0x00000
 #define H5C__SET_FLUSH_MARKER_FLAG		0x00001
@@ -205,6 +206,7 @@
 #define H5C__DEL_FROM_SLIST_ON_DESTROY_FLAG     0x08000
 #define H5C__DURING_FLUSH_FLAG                  0x10000 /* Set when the entire cache is being flushed */
 #define H5C__GENERATE_IMAGE_FLAG                0x20000 /* Set during parallel I/O */
+#define H5C__UPDATE_PAGE_BUFFER_FLAG            0x40000 /* Set during parallel I/O */
 
 /* Debugging/sanity checking/statistics settings */
 #ifndef NDEBUG
@@ -1066,9 +1068,9 @@ typedef int H5C_ring_t;
  *
  * is_read_only: Boolean flag that is only meaningful if is_protected is
  * 		TRUE.  In this circumstance, it indicates whether the
- * 		entry has been protected read only, or read/write.
+ * 		entry has been protected read-only, or read/write.
  *
- * 		If the entry has been protected read only (i.e. is_protected
+ * 		If the entry has been protected read-only (i.e. is_protected
  * 		and is_read_only are both TRUE), we allow the entry to be
  * 		protected more than once.
  *
@@ -1078,7 +1080,7 @@ typedef int H5C_ring_t;
  *		the entry is actually unprotected.
  *
  * ro_ref_count: Integer field used to maintain a count of the number of
- * 		outstanding read only protects on this entry.  This field
+ * 		outstanding read-only protects on this entry.  This field
  * 		must be zero whenever either is_protected or is_read_only
  * 		are TRUE.
  *
@@ -1458,13 +1460,13 @@ typedef int H5C_ring_t;
  *		the load of a cache image block, although other scenarios 
  *		are contemplated for the use of this feature.  Note that 
  *		unlike the usual prefetch situation, this means that a 
- *		pre fetched entry can be dirty, and/or can be a party to 
+ *		prefetched entry can be dirty, and/or can be a party to 
  *		flush dependency relationship(s).  This complicates matters 
  *		somewhat.
  *
- *		The essential feature of a pre-fetched entry is that it 
+ *		The essential feature of a prefetched entry is that it 
  *		consists only of a buffer containing the on disk image of 
- *		the entry.  Thus it must be  deserialized before it can 
+ *		the entry.  Thus it must be deserialized before it can 
  *		be passed back to the library on a protect call.  This 
  *		task is handled by H5C_deserialized_prefetched_entry().
  *		In essence, this routine calls the deserialize callback 
@@ -1475,7 +1477,7 @@ typedef int H5C_ring_t;
  *
  *		Further, if the prefetched entry is a flush dependency parent, 
  *		all its flush dependency children (which must also be 
- *		pre-fetched entries), must be tranfered to the new cache 
+ *		prefetched entries), must be tranfered to the new cache 
  *		entry returned by the deserailization callback.
  *
  *		Finally, if the prefetched entry is a flush dependency child, 
@@ -1511,6 +1513,46 @@ typedef int H5C_ring_t;
  *
  *		This field must be zero if prefetched is FALSE.  
  *
+ * prefetched_dirty:  Boolean field that must be set to FALSE unless the
+ *		following conditions hold:
+ *
+ *		    1) The file has been opened R/O.
+ *
+ *		    2) The entry is either a prefetched entry, or was 
+ *                     re-constructed from a prefetched entry.
+ *
+ *                  3) The base prefetched entry was marked dirty.
+ *
+ *              This field exists to solve the following problem with 
+ *              files containing cache images that are opened R/O.
+ *
+ *              If the cache image contains a dirty entry, that entry
+ *              must be marked clean when it is inserted into the cache
+ *              in the read-only case, as otherwise the metadata cache 
+ *              will attempt to flush it on file close -- which is poor 
+ *              form in the read-only case.
+ *
+ *              However, since the entry is marked clean, it is possible 
+ *              that the metadata cache will evict it if the size of the 
+ *              metadata in the file exceeds the size of the metadata cache,
+ *              and the application visits much of this data.
+ *
+ *              If this happens, and the metadata cache is then asked for
+ *              this entry, it will attempt to read it from file, and will
+ *              obtain either obsolete or invalid data depending on whether
+ *              the entry has ever been written to it assigned location in
+ *              the file.
+ *
+ *              With this background, the purpose of this field should be 
+ *              obvious -- when set, it allows the eviction candidate 
+ *              selection code to skip over the entry, thus avoiding the 
+ *              issue.
+ *
+ *              Since the issue only arises in the R/O case, there is 
+ *              no possible interaction with SWMR.  There are also 
+ *              potential interactions with Evict On Close -- at present,
+ *              we deal with this by disabling EOC in the R/O case.
+ *
  * serialization_count:  Integer field used to maintain a count of the 
  *		number of times each entry is serialized during cache 
  *		serialization.  While no entry should be serialized more than
@@ -1627,6 +1669,7 @@ typedef struct H5C_cache_entry_t {
     hbool_t                     prefetched;
     int                         prefetch_type_id;
     int32_t                     age;
+    hbool_t			prefetched_dirty;
 
 #ifndef NDEBUG	/* debugging field */
     int                         serialization_count;
@@ -2208,6 +2251,7 @@ H5_DLL herr_t H5C_expunge_entry(H5F_t *f, hid_t dxpl_id,
     const H5C_class_t *type, haddr_t addr, unsigned flags);
 H5_DLL herr_t H5C_flush_cache(H5F_t *f, hid_t dxpl_id, unsigned flags);
 H5_DLL herr_t H5C_flush_tagged_entries(H5F_t * f, hid_t dxpl_id, haddr_t tag); 
+H5_DLL herr_t H5C_force_cache_image_load(H5F_t * f, hid_t dxpl_id);
 H5_DLL herr_t H5C_evict_tagged_entries(H5F_t * f, hid_t dxpl_id, haddr_t tag, hbool_t match_global);
 H5_DLL herr_t H5C_expunge_tag_type_metadata(H5F_t *f, hid_t dxpl_id, haddr_t tag, int type_id, unsigned flags);
 H5_DLL herr_t H5C_get_tag(const void *thing, /*OUT*/ haddr_t *tag);
@@ -2259,7 +2303,6 @@ H5_DLL herr_t H5C_set_trace_file_ptr(H5C_t *cache_ptr, FILE *trace_file_ptr);
 H5_DLL herr_t H5C_stats(H5C_t *cache_ptr, const char *cache_name,
     hbool_t display_detailed_stats);
 H5_DLL void H5C_stats__reset(H5C_t *cache_ptr);
-H5_DLL herr_t H5C_dump_cache(H5C_t *cache_ptr, const char *cache_name);
 H5_DLL herr_t H5C_unpin_entry(void *thing);
 H5_DLL herr_t H5C_destroy_flush_dependency(void *parent_thing, void *child_thing);
 H5_DLL herr_t H5C_unprotect(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *thing,
@@ -2273,9 +2316,11 @@ H5_DLL herr_t H5C_retag_entries(H5C_t * cache_ptr, haddr_t src_tag, haddr_t dest
 H5_DLL herr_t H5C_cork(H5C_t *cache_ptr, haddr_t obj_addr, unsigned action, hbool_t *corked);
 H5_DLL herr_t H5C_get_entry_ring(const H5F_t *f, haddr_t addr, H5C_ring_t *ring);
 H5_DLL herr_t H5C_unsettle_entry_ring(void *thing);
+H5_DLL herr_t H5C_unsettle_ring(H5F_t * f, H5C_ring_t ring);
 H5_DLL herr_t H5C_remove_entry(void *thing);
 H5_DLL herr_t H5C_cache_image_status(H5F_t * f, hbool_t *load_ci_ptr, 
     hbool_t *write_ci_ptr);
+H5_DLL hbool_t H5C_cache_image_pending(const H5C_t *cache_ptr);
 
 #ifdef H5_HAVE_PARALLEL
 H5_DLL herr_t H5C_apply_candidate_list(H5F_t *f, hid_t dxpl_id,
@@ -2289,6 +2334,8 @@ H5_DLL herr_t H5C_mark_entries_as_clean(H5F_t *f, hid_t dxpl_id, unsigned ce_arr
 #endif /* H5_HAVE_PARALLEL */
 
 #ifndef NDEBUG	/* debugging functions */
+H5_DLL herr_t H5C_dump_cache(H5C_t *cache_ptr, const char *cache_name);
+H5_DLL herr_t H5C_dump_cache_LRU(H5C_t *cache_ptr, const char *cache_name);
 H5_DLL hbool_t H5C_get_serialization_in_progress(const H5C_t *cache_ptr);
 H5_DLL hbool_t H5C_cache_is_clean(const H5C_t *cache_ptr, H5C_ring_t inner_ring);
 H5_DLL herr_t H5C_dump_cache_skip_list(H5C_t *cache_ptr, char *calling_fcn);
diff --git a/src/H5Ctag.c b/src/H5Ctag.c
index 157a838..a9bcca1 100644
--- a/src/H5Ctag.c
+++ b/src/H5Ctag.c
@@ -465,7 +465,7 @@ H5C__evict_tagged_entries_cb(H5C_cache_entry_t *entry, void *_ctx)
             entry and we'll loop back around again (as evicting other
             entries will hopefully unpin this entry) */
         ctx->pinned_entries_need_evicted = TRUE;
-    else {
+    else if(!entry->prefetched_dirty) {
         /* Evict the Entry */
         if(H5C__flush_single_entry(ctx->f, ctx->dxpl_id, entry, H5C__FLUSH_INVALIDATE_FLAG | H5C__FLUSH_CLEAR_ONLY_FLAG | H5C__DEL_FROM_SLIST_ON_DESTROY_FLAG) < 0)
             HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, H5_ITER_ERROR, "Entry eviction failed.")
diff --git a/src/H5F.c b/src/H5F.c
index 5fd3a7d..a0f7599 100644
--- a/src/H5F.c
+++ b/src/H5F.c
@@ -406,7 +406,7 @@ H5Fis_hdf5(const char *name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADRANGE, FAIL, "no file name specified")
 
     /* call the private is_HDF5 function */
-    if((ret_value = H5F_is_hdf5(name, H5AC_ind_read_dxpl_id)) < 0)
+    if((ret_value = H5F__is_hdf5(name, H5AC_ind_read_dxpl_id, H5AC_rawdata_dxpl_id)) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_NOTHDF5, FAIL, "unable open file")
 
 done:
@@ -535,7 +535,7 @@ done:
  * Modifications:
  *	  	Robb Matzke, 1997-07-18
  *		File struct creation and destruction is through H5F_new() and
- *		H5F_dest(). Reading the root symbol table entry is done with
+ *		H5F__dest(). Reading the root symbol table entry is done with
  *		H5G_decode().
  *
  *  		Robb Matzke, 1997-09-23
@@ -713,12 +713,12 @@ H5Fflush(hid_t object_id, H5F_scope_t scope)
         /* Flush other files, depending on scope */
         if(H5F_SCOPE_GLOBAL == scope) {
             /* Call the flush routine for mounted file hierarchies */
-            if(H5F_flush_mounts(f, H5AC_ind_read_dxpl_id) < 0)
+            if(H5F_flush_mounts(f, H5AC_ind_read_dxpl_id, H5AC_rawdata_dxpl_id) < 0)
                 HGOTO_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to flush mounted file hierarchy")
         } /* end if */
         else {
             /* Call the flush routine, for this file */
-            if(H5F_flush(f, H5AC_ind_read_dxpl_id, FALSE) < 0)
+            if(H5F__flush(f, H5AC_ind_read_dxpl_id, H5AC_rawdata_dxpl_id, FALSE) < 0)
                 HGOTO_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to flush file's cached information")
         } /* end else */
     } /* end if */
@@ -773,7 +773,7 @@ H5Fclose(hid_t file_id)
         if((nref = H5I_get_ref(file_id, FALSE)) < 0)
             HGOTO_ERROR(H5E_ATOM, H5E_CANTGET, FAIL, "can't get ID ref count")
         if(nref == 1)
-            if(H5F_flush(f, H5AC_ind_read_dxpl_id, FALSE) < 0)
+            if(H5F__flush(f, H5AC_ind_read_dxpl_id, H5AC_rawdata_dxpl_id, FALSE) < 0)
                 HGOTO_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "unable to flush cache")
     } /* end if */
 
@@ -838,7 +838,7 @@ H5Freopen(hid_t file_id)
 
 done:
     if(ret_value < 0 && new_file)
-        if(H5F_dest(new_file, H5AC_ind_read_dxpl_id, FALSE) < 0)
+        if(H5F__dest(new_file, H5AC_ind_read_dxpl_id, H5AC_rawdata_dxpl_id, FALSE) < 0)
             HDONE_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL, "can't close file")
 
     FUNC_LEAVE_API(ret_value)
@@ -1042,7 +1042,7 @@ H5Fget_file_image(hid_t file_id, void *buf_ptr, size_t buf_len)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "not a file ID")
 
     /* call private get_file_image function */
-    if((ret_value = H5F_get_file_image(file, buf_ptr, buf_len, H5AC_ind_read_dxpl_id)) < 0)
+    if((ret_value = H5F_get_file_image(file, buf_ptr, buf_len, H5AC_ind_read_dxpl_id, H5AC_rawdata_dxpl_id)) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "unable to get file image")
 
 done:
@@ -1619,7 +1619,7 @@ H5Fstart_swmr_write(hid_t file_id)
     H5G_name_t *obj_paths=NULL;	/* Group hierarchy path */
     size_t u;               	/* Local index variable */
     hbool_t setup = FALSE;	/* Boolean flag to indicate whether SWMR setting is enabled */
-    H5F_io_info_t fio_info;    	/* I/O info for operation */
+    H5F_io_info2_t fio_info;    /* I/O info for operation */
     herr_t ret_value = SUCCEED;	/* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -1650,7 +1650,7 @@ H5Fstart_swmr_write(hid_t file_id)
         HGOTO_ERROR(H5E_FILE, H5E_UNSUPPORTED, FAIL, "can't have both SWMR and MDC cache image")
 
     /* Flush data buffers */
-    if(H5F_flush(file, H5AC_ind_read_dxpl_id, FALSE) < 0)
+    if(H5F__flush(file, H5AC_ind_read_dxpl_id, H5AC_rawdata_dxpl_id, FALSE) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to flush file's cached information")
 
     /* Get the # of opened named datatypes and attributes */
@@ -1704,7 +1704,9 @@ H5Fstart_swmr_write(hid_t file_id)
 
     /* Set up I/O info for operation */
     fio_info.f = file;
-    if(NULL == (fio_info.dxpl = (H5P_genplist_t *)H5I_object(H5AC_ind_read_dxpl_id)))
+    if(NULL == (fio_info.meta_dxpl = (H5P_genplist_t *)H5I_object(H5AC_ind_read_dxpl_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+    if(NULL == (fio_info.raw_dxpl = (H5P_genplist_t *)H5I_object(H5AC_rawdata_dxpl_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
 
     /* Flush and reset the accumulator */
@@ -1923,7 +1925,7 @@ H5Fset_latest_format(hid_t file_id, hbool_t latest_format)
     latest_flags = H5F_USE_LATEST_FLAGS(f, H5F_LATEST_ALL_FLAGS);
     if(latest_format != (H5F_LATEST_ALL_FLAGS == latest_flags)) {
         /* Call the flush routine, for this file */
-        if(H5F_flush(f, H5AC_ind_read_dxpl_id, FALSE) < 0)
+        if(H5F__flush(f, H5AC_ind_read_dxpl_id, H5AC_rawdata_dxpl_id, FALSE) < 0)
             HGOTO_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to flush file's cached information")
 
         /* Toggle the 'latest format' flag */
@@ -1973,7 +1975,9 @@ H5Fformat_convert(hid_t fid)
 
         /* Check for persistent freespace manager, which needs to be downgraded */
         if(!(f->shared->fs_strategy == H5F_FILE_SPACE_STRATEGY_DEF &&
-                f->shared->fs_threshold == H5F_FREE_SPACE_THRESHOLD_DEF)) {
+             f->shared->fs_persist == H5F_FREE_SPACE_PERSIST_DEF &&
+             f->shared->fs_threshold == H5F_FREE_SPACE_THRESHOLD_DEF &&
+             f->shared->fs_page_size == H5F_FILE_SPACE_PAGE_SIZE_DEF)) {
             /* Check to remove free-space manager info message from superblock extension */
             if(H5F_addr_defined(f->shared->sblock->ext_addr))
                 if(H5F_super_ext_remove_msg(f, H5AC_ind_read_dxpl_id, H5O_FSINFO_ID) < 0)
@@ -1985,7 +1989,9 @@ H5Fformat_convert(hid_t fid)
 
             /* Set non-persistent freespace manager */
             f->shared->fs_strategy = H5F_FILE_SPACE_STRATEGY_DEF;
+            f->shared->fs_persist = H5F_FREE_SPACE_PERSIST_DEF;
             f->shared->fs_threshold = H5F_FREE_SPACE_THRESHOLD_DEF;
+            f->shared->fs_page_size = H5F_FILE_SPACE_PAGE_SIZE_DEF;
 
             /* Indicate that the superblock should be marked dirty */
             mark_dirty = TRUE;
@@ -2004,3 +2010,79 @@ done:
     FUNC_LEAVE_API(ret_value)
 } /* end H5Fformat_convert() */
 
+
+/*-------------------------------------------------------------------------
+ * Function:    H5Freset_page_buffering_stats
+ *
+ * Purpose:     Resets statistics for the page buffer layer.
+ *
+ * Return:      Success:        SUCCEED
+ *              Failure:        FAIL
+ *
+ * Programmer:  Mohamad Chaarawi
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Freset_page_buffering_stats(hid_t file_id)
+{
+    H5F_t   *file;                      /* File to reset stats on */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE1("e", "i", file_id);
+
+    /* Check args */
+    if(NULL == (file = (H5F_t *)H5I_object(file_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
+    if(NULL == file->shared->page_buf)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "page buffering not enabled on file")
+
+    /* Reset the statistics */
+    if(H5PB_reset_stats(file->shared->page_buf) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't reset stats for page buffering")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+}   /* H5Freset_page_buffering_stats() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5Fget_page_buffering_stats
+ *
+ * Purpose:     Retrieves statistics for the page buffer layer.
+ *
+ * Return:      Success:        SUCCEED
+ *              Failure:        FAIL
+ *
+ * Programmer:  Mohamad Chaarawi
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Fget_page_buffering_stats(hid_t file_id, unsigned accesses[2], unsigned hits[2],
+    unsigned misses[2], unsigned evictions[2], unsigned bypasses[2])
+{
+    H5F_t      *file;                   /* File object for file ID */
+    herr_t     ret_value = SUCCEED;     /* Return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE6("e", "i*Iu*Iu*Iu*Iu*Iu", file_id, accesses, hits, misses, evictions,
+             bypasses);
+
+    /* Check args */
+    if(NULL == (file = (H5F_t *)H5I_object_verify(file_id, H5I_FILE)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "not a file ID")
+    if(NULL == file->shared->page_buf)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "page buffering not enabled on file")
+    if(NULL == accesses || NULL == hits || NULL == misses || NULL == evictions || NULL == bypasses)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "NULL input parameters for stats")
+
+    /* Get the statistics */
+    if(H5PB_get_stats(file->shared->page_buf, accesses, hits, misses, evictions, bypasses) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "can't retrieve stats for page buffering")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* H5Fget_page_buffering_stats() */
+
diff --git a/src/H5FD.c b/src/H5FD.c
index 660f496..96d1230 100644
--- a/src/H5FD.c
+++ b/src/H5FD.c
@@ -1530,7 +1530,7 @@ herr_t
 H5FDread(H5FD_t *file, H5FD_mem_t type, hid_t dxpl_id, haddr_t addr, size_t size,
 	 void *buf/*out*/)
 {
-    H5P_genplist_t *dxpl;               /* DXPL object */
+    H5FD_io_info_t fdio_info;           /* File driver I/O object */
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -1549,13 +1549,24 @@ H5FDread(H5FD_t *file, H5FD_mem_t type, hid_t dxpl_id, haddr_t addr, size_t size
     if(!buf)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "null result buffer")
 
-    /* Get the DXPL plist object for DXPL ID */
-    if(NULL == (dxpl = (H5P_genplist_t *)H5I_object(dxpl_id)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+    /* Set up the file driver I/O info object */
+    fdio_info.file = file;
+    if(H5FD_MEM_DRAW == type) {
+        if(NULL == (fdio_info.meta_dxpl = (H5P_genplist_t *)H5I_object(H5AC_ind_read_dxpl_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+        if(NULL == (fdio_info.raw_dxpl = (H5P_genplist_t *)H5I_object(dxpl_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+    } /* end if */
+    else {
+        if(NULL == (fdio_info.meta_dxpl = (H5P_genplist_t *)H5I_object(dxpl_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+        if(NULL == (fdio_info.raw_dxpl = (H5P_genplist_t *)H5I_object(H5AC_rawdata_dxpl_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+    } /* end else */
 
     /* Do the real work */
     /* (Note compensating for base address addition in internal routine) */
-    if(H5FD_read(file, dxpl, type, addr - file->base_addr, size, buf) < 0)
+    if(H5FD_read(&fdio_info, type, addr - file->base_addr, size, buf) < 0)
 	HGOTO_ERROR(H5E_VFL, H5E_READERROR, FAIL, "file read request failed")
 
 done:
@@ -1584,7 +1595,7 @@ herr_t
 H5FDwrite(H5FD_t *file, H5FD_mem_t type, hid_t dxpl_id, haddr_t addr, size_t size,
 	  const void *buf)
 {
-    H5P_genplist_t *dxpl;               /* DXPL object */
+    H5FD_io_info_t fdio_info;           /* File driver I/O object */
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -1602,13 +1613,24 @@ H5FDwrite(H5FD_t *file, H5FD_mem_t type, hid_t dxpl_id, haddr_t addr, size_t siz
     if(!buf)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "null buffer")
 
-    /* Get the DXPL plist object for DXPL ID */
-    if(NULL == (dxpl = (H5P_genplist_t *)H5I_object(dxpl_id)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+    /* Set up the file driver I/O info object */
+    fdio_info.file = file;
+    if(H5FD_MEM_DRAW == type) {
+        if(NULL == (fdio_info.meta_dxpl = (H5P_genplist_t *)H5I_object(H5AC_ind_read_dxpl_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+        if(NULL == (fdio_info.raw_dxpl = (H5P_genplist_t *)H5I_object(dxpl_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+    } /* end if */
+    else {
+        if(NULL == (fdio_info.meta_dxpl = (H5P_genplist_t *)H5I_object(dxpl_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+        if(NULL == (fdio_info.raw_dxpl = (H5P_genplist_t *)H5I_object(H5AC_rawdata_dxpl_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+    } /* end else */
 
     /* The real work */
     /* (Note compensating for base address addition in internal routine) */
-    if(H5FD_write(file, dxpl, type, addr - file->base_addr, size, buf) < 0)
+    if(H5FD_write(&fdio_info, type, addr - file->base_addr, size, buf) < 0)
 	HGOTO_ERROR(H5E_VFL, H5E_WRITEERROR, FAIL, "file write request failed")
 
 done:
@@ -2032,3 +2054,27 @@ H5FD_get_base_addr(const H5FD_t *file)
     FUNC_LEAVE_NOAPI(file->base_addr)
 } /* end H5FD_get_base_addr() */
 
+
+/*--------------------------------------------------------------------------
+ * Function:    H5FD_set_paged_aggr
+ *
+ * Purpose:     Set "paged_aggr" for the file.
+ *
+ * Return:      Non-negative if succeed; negative if fails.
+ *
+ * Programmer:  Vailin Choi; April 2013
+ *
+ *--------------------------------------------------------------------------
+ */
+herr_t
+H5FD_set_paged_aggr(H5FD_t *file, hbool_t paged)
+{
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    HDassert(file);
+
+    /* Indicate whether paged aggregation for handling file space is enabled or not */
+    file->paged_aggr = paged;
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5FD_set_paged_aggr() */
diff --git a/src/H5FDint.c b/src/H5FDint.c
index 744c3d1..0809ac8 100644
--- a/src/H5FDint.c
+++ b/src/H5FDint.c
@@ -93,12 +93,9 @@
  *-------------------------------------------------------------------------
  */
 herr_t
-H5FD_locate_signature(H5FD_t *file,
-#ifndef H5_DEBUG_BUILD
-const
-#endif /* H5_DEBUG_BUILD */
-H5P_genplist_t *dxpl, haddr_t *sig_addr)
+H5FD_locate_signature(H5FD_io_info_t *fdio_info, haddr_t *sig_addr)
 {
+    H5FD_t         *file;
     haddr_t         addr, eoa, eof;
     uint8_t         buf[H5F_SIGNATURE_LEN];
     unsigned        n, maxpow;
@@ -106,6 +103,10 @@ H5P_genplist_t *dxpl, haddr_t *sig_addr)
 
     FUNC_ENTER_NOAPI_NOINIT
 
+    HDassert(fdio_info);
+    file = fdio_info->file;
+    HDassert(file);
+
     /* Find the least N such that 2^N is larger than the file size */
     eof = H5FD_get_eof(file, H5FD_MEM_SUPER);
     eoa = H5FD_get_eoa(file, H5FD_MEM_SUPER);
@@ -124,7 +125,7 @@ H5P_genplist_t *dxpl, haddr_t *sig_addr)
         addr = (8 == n) ? 0 : (haddr_t)1 << n;
         if(H5FD_set_eoa(file, H5FD_MEM_SUPER, addr + H5F_SIGNATURE_LEN) < 0)
             HGOTO_ERROR(H5E_IO, H5E_CANTINIT, FAIL, "unable to set EOA value for file signature")
-        if(H5FD_read(file, dxpl, H5FD_MEM_SUPER, addr, (size_t)H5F_SIGNATURE_LEN, buf) < 0)
+        if(H5FD_read(fdio_info, H5FD_MEM_SUPER, addr, (size_t)H5F_SIGNATURE_LEN, buf) < 0)
             HGOTO_ERROR(H5E_IO, H5E_CANTINIT, FAIL, "unable to read file signature")
         if(!HDmemcmp(buf, H5F_SIGNATURE, (size_t)H5F_SIGNATURE_LEN))
             break;
@@ -162,29 +163,36 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5FD_read(H5FD_t *file,
-#ifndef H5_DEBUG_BUILD
-const
-#endif /* H5_DEBUG_BUILD */
-H5P_genplist_t *dxpl, H5FD_mem_t type, haddr_t addr,
+H5FD_read(H5FD_io_info_t *fdio_info, H5FD_mem_t type, haddr_t addr,
     size_t size, void *buf/*out*/)
 {
+    H5FD_t      *file;
+    H5P_genplist_t *io_dxpl;
     haddr_t     eoa = HADDR_UNDEF;
     herr_t      ret_value = SUCCEED;       /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
 
+    HDassert(fdio_info);
+    file = fdio_info->file;
     HDassert(file && file->cls);
-    HDassert(TRUE == H5P_class_isa(H5P_CLASS(dxpl), H5P_CLS_DATASET_XFER_g));
+    HDassert(TRUE == H5P_class_isa(H5P_CLASS(fdio_info->meta_dxpl), H5P_CLS_DATASET_XFER_g));
+    HDassert(TRUE == H5P_class_isa(H5P_CLASS(fdio_info->raw_dxpl), H5P_CLS_DATASET_XFER_g));
     HDassert(buf);
 
+    /* Set up proper DXPL for I/O */
+    if(H5FD_MEM_DRAW == type)
+        io_dxpl = fdio_info->raw_dxpl;
+    else
+        io_dxpl = fdio_info->meta_dxpl;
+
     /* Sanity check the dxpl type against the mem type */
 #ifdef H5_DEBUG_BUILD
     {
         H5FD_dxpl_type_t dxpl_type;    /* Property indicating the type of the internal dxpl */
 
         /* get the dxpl type */
-        if(H5P_get(dxpl, H5FD_DXPL_TYPE_NAME, &dxpl_type) < 0)
+        if(H5P_get(io_dxpl, H5FD_DXPL_TYPE_NAME, &dxpl_type) < 0)
             HGOTO_ERROR(H5E_VFL, H5E_CANTGET, FAIL, "can't retrieve dxpl type")
 
         /* we shouldn't be here if the dxpl is labeled with NO I/O */
@@ -219,7 +227,7 @@ H5P_genplist_t *dxpl, H5FD_mem_t type, haddr_t addr,
         HGOTO_ERROR(H5E_ARGS, H5E_OVERFLOW, FAIL, "addr overflow, addr = %llu, size = %llu, eoa = %llu", (unsigned long long)(addr + file->base_addr), (unsigned long long)size, (unsigned long long)eoa)
 
     /* Dispatch to driver */
-    if((file->cls->read)(file, type, H5P_PLIST_ID(dxpl), addr + file->base_addr, size, buf) < 0)
+    if((file->cls->read)(file, type, H5P_PLIST_ID(io_dxpl), addr + file->base_addr, size, buf) < 0)
         HGOTO_ERROR(H5E_VFL, H5E_READERROR, FAIL, "driver read request failed")
 
 done:
@@ -241,29 +249,36 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5FD_write(H5FD_t *file,
-#ifndef H5_DEBUG_BUILD
-const
-#endif /* H5_DEBUG_BUILD */
-H5P_genplist_t *dxpl, H5FD_mem_t type, haddr_t addr,
+H5FD_write(const H5FD_io_info_t *fdio_info, H5FD_mem_t type, haddr_t addr,
     size_t size, const void *buf)
 {
+    H5FD_t      *file;
+    H5P_genplist_t *io_dxpl;
     haddr_t     eoa = HADDR_UNDEF;
     herr_t      ret_value = SUCCEED;       /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
 
+    HDassert(fdio_info);
+    file = fdio_info->file;
     HDassert(file && file->cls);
-    HDassert(TRUE == H5P_class_isa(H5P_CLASS(dxpl), H5P_CLS_DATASET_XFER_g));
+    HDassert(TRUE == H5P_class_isa(H5P_CLASS(fdio_info->meta_dxpl), H5P_CLS_DATASET_XFER_g));
+    HDassert(TRUE == H5P_class_isa(H5P_CLASS(fdio_info->raw_dxpl), H5P_CLS_DATASET_XFER_g));
     HDassert(buf);
 
+    /* Set up proper DXPL for I/O */
+    if(H5FD_MEM_DRAW == type)
+        io_dxpl = fdio_info->raw_dxpl;
+    else
+        io_dxpl = fdio_info->meta_dxpl;
+
     /* Sanity check the dxpl type against the mem type */
 #ifdef H5_DEBUG_BUILD
     {
         H5FD_dxpl_type_t dxpl_type;    /* Property indicating the type of the internal dxpl */
 
         /* get the dxpl type */
-        if(H5P_get(dxpl, H5FD_DXPL_TYPE_NAME, &dxpl_type) < 0)
+        if(H5P_get(io_dxpl, H5FD_DXPL_TYPE_NAME, &dxpl_type) < 0)
             HGOTO_ERROR(H5E_VFL, H5E_CANTGET, FAIL, "can't retrieve dxpl type")
 
         /* we shouldn't be here if the dxpl is labeled with NO I/O */
@@ -291,7 +306,7 @@ H5P_genplist_t *dxpl, H5FD_mem_t type, haddr_t addr,
                     (unsigned long long)(addr+ file->base_addr), (unsigned long long)size, (unsigned long long)eoa)
 
     /* Dispatch to driver */
-    if((file->cls->write)(file, type, H5P_PLIST_ID(dxpl), addr + file->base_addr, size, buf) < 0)
+    if((file->cls->write)(file, type, H5P_PLIST_ID(io_dxpl), addr + file->base_addr, size, buf) < 0)
         HGOTO_ERROR(H5E_VFL, H5E_WRITEERROR, FAIL, "driver write request failed")
 
 done:
diff --git a/src/H5FDlog.c b/src/H5FDlog.c
index 03228d2..f320946 100644
--- a/src/H5FDlog.c
+++ b/src/H5FDlog.c
@@ -934,13 +934,7 @@ H5FD_log_alloc(H5FD_t *_file, H5FD_mem_t type, hid_t H5_ATTR_UNUSED dxpl_id, hsi
     /* Compute the address for the block to allocate */
     addr = file->eoa;
 
-    /* Check if we need to align this block */
-    if(size >= file->pub.threshold) {
-        /* Check for an already aligned block */
-        if(addr % file->pub.alignment != 0)
-            addr = ((addr / file->pub.alignment) + 1) * file->pub.alignment;
-    } /* end if */
-
+    /* Extend the end-of-allocated space address */
     file->eoa = addr + size;
 
     /* Retain the (first) flavor of the information written to the file */
diff --git a/src/H5FDmulti.c b/src/H5FDmulti.c
index 7e12869..0ab7fc5 100644
--- a/src/H5FDmulti.c
+++ b/src/H5FDmulti.c
@@ -1194,6 +1194,8 @@ H5FD_multi_query(const H5FD_t *_f, unsigned long *flags /* out */)
         *flags = 0;
         *flags |= H5FD_FEAT_DATA_SIEVE;             /* OK to perform data sieving for faster raw data reads & writes */
         *flags |= H5FD_FEAT_AGGREGATE_SMALLDATA;    /* OK to aggregate "small" raw data allocations */
+        *flags |= H5FD_FEAT_USE_ALLOC_SIZE;     /* OK just pass the allocation size to the alloc callback */
+        *flags |= H5FD_FEAT_PAGED_AGGR;         /* OK special file space mapping for paged aggregation */
     } /* end if */
 
     return(0);
@@ -1538,6 +1540,14 @@ H5FD_multi_alloc(H5FD_t *_file, H5FD_mem_t type, hid_t dxpl_id, hsize_t size)
     mmt = file->fa.memb_map[type];
     if (H5FD_MEM_DEFAULT==mmt) mmt = type;
 
+    /* XXX: NEED to work on this again */
+    if(file->pub.paged_aggr) {
+        ALL_MEMBERS(mt) {
+            if(file->memb[mt])
+                file->memb[mt]->paged_aggr = file->pub.paged_aggr;
+        } END_MEMBERS;
+    }
+
     if (HADDR_UNDEF==(addr=H5FDalloc(file->memb[mmt], mmt, dxpl_id, size)))
         H5Epush_ret(func, H5E_ERR_CLS, H5E_INTERNAL, H5E_BADVALUE, "member file can't alloc", HADDR_UNDEF)
     addr += file->fa.memb_addr[mmt];
diff --git a/src/H5FDprivate.h b/src/H5FDprivate.h
index 45f0187..c64ec30 100644
--- a/src/H5FDprivate.h
+++ b/src/H5FDprivate.h
@@ -115,6 +115,19 @@ typedef enum {
 #define H5FD_DXPL_TYPE_NAME              "H5P_dxpl_type"
 #endif /* H5_DEBUG_BUILD */
 
+/* I/O Info for an operation */
+typedef struct H5FD_io_info_t {
+    H5FD_t *file;                       /* File driver object */
+#ifndef H5_DEBUG_BUILD
+    const
+#endif /* H5_DEBUG_BUILD */
+    H5P_genplist_t *meta_dxpl;          /* Metadata DXPL object */
+#ifndef H5_DEBUG_BUILD
+    const
+#endif /* H5_DEBUG_BUILD */
+    H5P_genplist_t *raw_dxpl;           /* Raw data DXPL object */
+} H5FD_io_info_t;
+
 
 /*****************************/
 /* Library Private Variables */
@@ -126,15 +139,10 @@ typedef enum {
 /******************************/
 
 /* Forward declarations for prototype arguments */
-struct H5P_genplist_t;
 struct H5F_t;
 
 H5_DLL int H5FD_term_interface(void);
-H5_DLL herr_t H5FD_locate_signature(H5FD_t *file,
-#ifndef H5_DEBUG_BUILD
-const
-#endif /* H5_DEBUG_BUILD */
-H5P_genplist_t *dxpl, haddr_t *sig_addr);
+H5_DLL herr_t H5FD_locate_signature(H5FD_io_info_t *fdio_info, haddr_t *sig_addr);
 H5_DLL H5FD_class_t *H5FD_get_class(hid_t id);
 H5_DLL hsize_t H5FD_sb_size(H5FD_t *file);
 H5_DLL herr_t H5FD_sb_encode(H5FD_t *file, char *name/*out*/, uint8_t *buf);
@@ -146,8 +154,8 @@ H5_DLL H5FD_t *H5FD_open(const char *name, unsigned flags, hid_t fapl_id,
 		  haddr_t maxaddr);
 H5_DLL herr_t H5FD_close(H5FD_t *file);
 H5_DLL int H5FD_cmp(const H5FD_t *f1, const H5FD_t *f2);
-H5_DLL haddr_t H5FD_alloc(H5FD_t *file, hid_t dxpl_id, H5FD_mem_t type, struct H5F_t *f,
-    hsize_t size, haddr_t *align_addr, hsize_t *align_size);
+H5_DLL haddr_t H5FD_alloc(H5FD_t *file, hid_t dxpl_id, H5FD_mem_t type, 
+    struct H5F_t *f, hsize_t size, haddr_t *frag_addr, hsize_t *frag_size);
 H5_DLL herr_t H5FD_free(H5FD_t *file, hid_t dxpl_id, H5FD_mem_t type, struct H5F_t *f,
     haddr_t addr, hsize_t size);
 H5_DLL htri_t H5FD_try_extend(H5FD_t *file, H5FD_mem_t type, struct H5F_t *f,
@@ -159,17 +167,9 @@ H5_DLL haddr_t H5FD_get_maxaddr(const H5FD_t *file);
 H5_DLL herr_t H5FD_get_feature_flags(const H5FD_t *file, unsigned long *feature_flags);
 H5_DLL herr_t H5FD_set_feature_flags(H5FD_t *file, unsigned long feature_flags);
 H5_DLL herr_t H5FD_get_fs_type_map(const H5FD_t *file, H5FD_mem_t *type_map);
-H5_DLL herr_t H5FD_read(H5FD_t *file,
-#ifndef H5_DEBUG_BUILD
-const
-#endif /* H5_DEBUG_BUILD */
-H5P_genplist_t *dxpl, H5FD_mem_t type,
+H5_DLL herr_t H5FD_read(H5FD_io_info_t *fdio_info, H5FD_mem_t type,
     haddr_t addr, size_t size, void *buf/*out*/);
-H5_DLL herr_t H5FD_write(H5FD_t *file,
-#ifndef H5_DEBUG_BUILD
-const
-#endif /* H5_DEBUG_BUILD */
-H5P_genplist_t *dxpl, H5FD_mem_t type,
+H5_DLL herr_t H5FD_write(const H5FD_io_info_t *fdio_info, H5FD_mem_t type,
     haddr_t addr, size_t size, const void *buf);
 H5_DLL herr_t H5FD_flush(H5FD_t *file, hid_t dxpl_id, hbool_t closing);
 H5_DLL herr_t H5FD_truncate(H5FD_t *file, hid_t dxpl_id, hbool_t closing);
@@ -179,6 +179,7 @@ H5_DLL herr_t H5FD_get_fileno(const H5FD_t *file, unsigned long *filenum);
 H5_DLL herr_t H5FD_get_vfd_handle(H5FD_t *file, hid_t fapl, void** file_handle);
 H5_DLL herr_t H5FD_set_base_addr(H5FD_t *file, haddr_t base_addr);
 H5_DLL haddr_t H5FD_get_base_addr(const H5FD_t *file);
+H5_DLL herr_t H5FD_set_paged_aggr(H5FD_t *file, hbool_t paged);
 
 /* Function prototypes for MPI based VFDs*/
 #ifdef H5_HAVE_PARALLEL
diff --git a/src/H5FDpublic.h b/src/H5FDpublic.h
index 436be10..883b28d 100644
--- a/src/H5FDpublic.h
+++ b/src/H5FDpublic.h
@@ -239,6 +239,19 @@ typedef enum H5F_mem_t	H5FD_mem_t;
      * driver supports the single-writer/multiple-readers I/O pattern.
      */
 #define H5FD_FEAT_SUPPORTS_SWMR_IO      0x00001000
+    /*
+     * Defining H5FD_FEAT_USE_ALLOC_SIZE for a VFL driver
+     * means that the library will just pass the allocation size to the
+     * the driver's allocation callback which will eventually handle alignment.
+     * This is specifically used for the multi/split driver.
+     */
+#define H5FD_FEAT_USE_ALLOC_SIZE	0x00002000
+    /*
+     * Defining H5FD_FEAT_PAGED_AGGR for a VFL driver
+     * means that the driver needs special file space mapping for paged aggregation.
+     * This is specifically used for the multi/split driver.
+     */
+#define H5FD_FEAT_PAGED_AGGR		0x00004000
 
 /* Forward declaration */
 typedef struct H5FD_t H5FD_t;
@@ -307,6 +320,7 @@ struct H5FD_t {
     /* Space allocation management fields */
     hsize_t             threshold;      /* Threshold for alignment  */
     hsize_t             alignment;      /* Allocation alignment     */
+    hbool_t             paged_aggr;     /* Paged aggregation for file space is enabled or not */
 };
 
 /* Define enum for the source of file image callbacks */
diff --git a/src/H5FDspace.c b/src/H5FDspace.c
index fcddecf..0ad3cf0 100644
--- a/src/H5FDspace.c
+++ b/src/H5FDspace.c
@@ -99,7 +99,7 @@ H5FL_DEFINE(H5FD_free_t);
  *-------------------------------------------------------------------------
  */
 static haddr_t
-H5FD_extend(H5FD_t *file, H5FD_mem_t type, hbool_t new_block, hsize_t size, haddr_t *frag_addr, hsize_t *frag_size)
+H5FD_extend(H5FD_t *file, H5FD_mem_t type, hsize_t size)
 {
     hsize_t orig_size = size;   /* Original allocation size */
     haddr_t eoa;                /* Address of end-of-allocated space */
@@ -117,40 +117,18 @@ H5FD_extend(H5FD_t *file, H5FD_mem_t type, hbool_t new_block, hsize_t size, hadd
     /* Get current end-of-allocated space address */
     eoa = file->cls->get_eoa(file, type);
 
-    /* Compute extra space to allocate, if this is a new block and should be aligned */
-    extra = 0;
-    if(new_block && file->alignment > 1 && orig_size >= file->threshold) {
-        hsize_t mis_align;              /* Amount EOA is misaligned */
-
-        /* Check for EOA already aligned */
-        if((mis_align = (eoa % file->alignment)) > 0) {
-            extra = file->alignment - mis_align;
-	    if(frag_addr)
-                *frag_addr = eoa - file->base_addr;     /* adjust for file's base address */
-	    if(frag_size)
-                *frag_size = extra;
-	} /* end if */
-    } /* end if */
-
-    /* Add in extra allocation amount */
-    size += extra;
-
     /* Check for overflow when extending */
     if(H5F_addr_overflow(eoa, size) || (eoa + size) > file->maxaddr)
         HGOTO_ERROR(H5E_VFL, H5E_NOSPACE, HADDR_UNDEF, "file allocation request failed")
 
-    /* Set the [possibly aligned] address to return */
-    ret_value = eoa + extra;
+    /* Set the [NOT aligned] address to return */
+    ret_value = eoa;
 
     /* Extend the end-of-allocated space address */
     eoa += size;
     if(file->cls->set_eoa(file, type, eoa) < 0)
         HGOTO_ERROR(H5E_VFL, H5E_NOSPACE, HADDR_UNDEF, "file allocation request failed")
 
-    /* Post-condition sanity check */
-    if(new_block && file->alignment && orig_size >= file->threshold)
-	HDassert(!(ret_value % file->alignment));
-
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5FD_extend() */
@@ -160,6 +138,8 @@ done:
  * Function:    H5FD_alloc_real
  *
  * Purpose:     Allocate space in the file with the VFD
+ *              Note: the handling of alignment is moved up from each driver to
+ *              this routine.
  *
  * Return:      Success:    The format address of the new file memory.
  *              Failure:    The undefined address HADDR_UNDEF
@@ -170,8 +150,14 @@ done:
  *-------------------------------------------------------------------------
  */
 haddr_t
-H5FD_alloc_real(H5FD_t *file, hid_t dxpl_id, H5FD_mem_t type, hsize_t size, haddr_t *frag_addr, hsize_t *frag_size)
+H5FD_alloc_real(H5FD_t *file, hid_t dxpl_id, H5FD_mem_t type, hsize_t size, 
+    haddr_t *frag_addr, hsize_t *frag_size)
 {
+    hsize_t orig_size = size;   /* Original allocation size */
+    haddr_t eoa;                /* Address of end-of-allocated space */
+    hsize_t extra;              /* Extra space to allocate, to align request */
+    unsigned long flags = 0;    /* Driver feature flags */
+    hbool_t use_alloc_size;     /* Just pass alloc size to the driver */
     haddr_t ret_value = HADDR_UNDEF;    /* Return value */
 
     FUNC_ENTER_NOAPI(HADDR_UNDEF)
@@ -185,16 +171,53 @@ HDfprintf(stderr, "%s: type = %u, size = %Hu\n", FUNC, (unsigned)type, size);
     HDassert(type >= H5FD_MEM_DEFAULT && type < H5FD_MEM_NTYPES);
     HDassert(size > 0);
 
+    /* Check for query driver and call it */
+    if(file->cls->query)
+        (file->cls->query)(file, &flags);
+
+    /* Check for the driver feature flag */
+    use_alloc_size = flags & H5FD_FEAT_USE_ALLOC_SIZE;
+
+    /* Get current end-of-allocated space address */
+    eoa = file->cls->get_eoa(file, type);
+
+    /* Compute extra space to allocate, if this should be aligned */
+    extra = 0;
+    if(!file->paged_aggr && file->alignment > 1 && orig_size >= file->threshold) {
+        hsize_t mis_align;              /* Amount EOA is misaligned */
+
+        /* Check for EOA already aligned */
+        if((mis_align = (eoa % file->alignment)) > 0) {
+            extra = file->alignment - mis_align;
+            if(frag_addr)
+                *frag_addr = eoa - file->base_addr;     /* adjust for file's base address */
+            if(frag_size)
+                *frag_size = extra;
+        } /* end if */
+    } /* end if */
+
     /* Dispatch to driver `alloc' callback or extend the end-of-address marker */
+    /* For the multi/split driver: the size passed down to the alloc callback is the original size from H5FD_alloc() */
+    /* For all other drivers: the size passed down to the alloc callback is the size + [possibly] alignment size */
     if(file->cls->alloc) {
-        if((ret_value = (file->cls->alloc)(file, type, dxpl_id, size)) == HADDR_UNDEF)
+        ret_value = (file->cls->alloc)(file, type, dxpl_id, use_alloc_size ? size : size + extra);
+        if(!H5F_addr_defined(ret_value))
             HGOTO_ERROR(H5E_VFL, H5E_NOSPACE, HADDR_UNDEF, "driver allocation request failed")
     } /* end if */
     else {
-        if((ret_value = H5FD_extend(file, type, TRUE, size, frag_addr, frag_size)) == HADDR_UNDEF)
+        ret_value = H5FD_extend(file, type, size + extra);
+        if(!H5F_addr_defined(ret_value))
             HGOTO_ERROR(H5E_VFL, H5E_NOSPACE, HADDR_UNDEF, "driver eoa update request failed")
     } /* end else */
 
+    /* Set the [possibly aligned] address to return */
+    if(!use_alloc_size)
+        ret_value += extra;
+
+    /* Post-condition sanity check */
+    if(!file->paged_aggr && file->alignment > 1 && orig_size >= file->threshold)
+        HDassert(!(ret_value % file->alignment));
+
     /* Convert absolute file offset to relative address */
     ret_value -= file->base_addr;
 
@@ -420,7 +443,7 @@ H5FD_try_extend(H5FD_t *file, H5FD_mem_t type, H5F_t *f, hid_t dxpl_id,
     /* Check if the block is exactly at the end of the file */
     if(H5F_addr_eq(blk_end, eoa)) {
         /* Extend the object by extending the underlying file */
-        if(HADDR_UNDEF == H5FD_extend(file, type, FALSE, extra_requested, NULL, NULL))
+        if(HADDR_UNDEF == H5FD_extend(file, type, extra_requested))
             HGOTO_ERROR(H5E_VFL, H5E_CANTEXTEND, FAIL, "driver extend request failed")
 
         /* Mark EOA info dirty in cache, so change will get encoded */
diff --git a/src/H5FDstdio.c b/src/H5FDstdio.c
index 4c62bcc..13f728e 100644
--- a/src/H5FDstdio.c
+++ b/src/H5FDstdio.c
@@ -601,13 +601,6 @@ H5FD_stdio_alloc(H5FD_t *_file, H5FD_mem_t /*UNUSED*/ type, hid_t /*UNUSED*/ dxp
     /* Compute the address for the block to allocate */
     addr = file->eoa;
 
-    /* Check if we need to align this block */
-    if(size >= file->pub.threshold) {
-        /* Check for an already aligned block */
-        if((addr % file->pub.alignment) != 0)
-            addr = ((addr / file->pub.alignment) + 1) * file->pub.alignment;
-    } /* end if */
-
     file->eoa = addr + size;
 
     return addr;
diff --git a/src/H5FS.c b/src/H5FS.c
index 8644a6f..a433fbb 100644
--- a/src/H5FS.c
+++ b/src/H5FS.c
@@ -135,7 +135,7 @@ HDfprintf(stderr, "%s: Creating free space manager, nclasses = %Zu\n", FUNC, ncl
     fspace->swmr_write = (H5F_INTENT(f) & H5F_ACC_SWMR_WRITE) > 0;
 
     fspace->alignment = alignment;
-    fspace->threshold = threshold;
+    fspace->align_thres = threshold;
 
     /* Check if the free space tracker is supposed to be persistant */
     if(fs_addr) {
@@ -227,7 +227,7 @@ HDfprintf(stderr, "%s: fspace->rc = %u\n", FUNC, fspace->rc);
         HGOTO_ERROR(H5E_FSPACE, H5E_CANTINC, NULL, "unable to increment ref. count on free space header")
 
     fspace->alignment = alignment;
-    fspace->threshold = threshold;
+    fspace->align_thres = threshold;
 
     /* Unlock free space header */
     if(H5AC_unprotect(f, dxpl_id, H5AC_FSPACE_HDR, fs_addr, fspace, H5AC__NO_FLAGS_SET) < 0)
@@ -873,10 +873,7 @@ H5FS_alloc_sect(H5F_t *f, H5FS_t *fspace, hid_t dxpl_id)
     HDassert(fspace);
 
     if(!H5F_addr_defined(fspace->sect_addr) && fspace->sinfo && fspace->serial_sect_count > 0) {
-        /* Allocate space for section info from aggregator/vfd (or temp. address space) */
-        /* (The original version called H5MF_alloc(), but that may cause sect_size to change again) */
-        /* (This routine is only called during file close operations, so don't allocate from temp. address space) */
-        if(HADDR_UNDEF == (fspace->sect_addr = H5MF_aggr_vfd_alloc(f, H5FD_MEM_FSPACE_SINFO, dxpl_id, fspace->sect_size)))
+        if(HADDR_UNDEF == (fspace->sect_addr = H5MF_alloc(f, H5FD_MEM_FSPACE_SINFO, dxpl_id, fspace->sect_size)))
             HGOTO_ERROR(H5E_FSPACE, H5E_NOSPACE, FAIL, "file allocation failed for section info")
         fspace->alloc_sect_size = fspace->sect_size;
 
@@ -901,169 +898,6 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5FS_alloc_vfd_alloc_hdr_and_section_info
- *
- * Purpose:	This function is part of a hack to patch over a design
- *              flaw in the free space managers for file space allocation.  
- *		Specifically, if a free space manager allocates space for 
- *		its own section info, it is possible for it to 
- *		go into an infinite loop as it:
- *
- *                      1) computes the size of the section info
- *
- *                      2) allocates file space for the section info
- *
- *                      3) notices that the size of the section info
- *                         has changed
- *
- *                      4) deallocates the section info file space and
- *                         returns to 1) above.
- *
- *		Similarly, if it allocates space for its own header, it 
- *		can go into an infinte loop as it:
- *
- *			1) allocates space for the header
- *
- *			2) notices that the free space manager is empty
- *			   and thus should not have file space allocated 
- *			   to its header
- *
- *			3) frees the space allocated to the header
- *
- *			4) notices that the free space manager is not 
- *			   empty and thus must have file space allocated
- *			   to it, and thus returns to 1) above.
- *
- *              In a nutshell, the solution applied in this hack is to
- *		deallocate file space for the free space manager(s) that
- *		handle FSM header and/or section info file space allocations,
- *              wait until all other allocation/deallocation requests have
- *              been handled, and then test to see if the free space manager(s)
- *		in question are empty.  If they are, do nothing.  If they 
- *		are not, allocate space for them at end of file bypassing the
- *		usual file space allocation calls, and thus avoiding the 
- *		potential infinite loops.
- *
- *		The purpose of this function is to allocate file space for 
- *		the header and section info of the target free space manager 
- *		directly from the VFD if needed.  In this case the function 
- *		also re-inserts the header and section info in the metadata 
- *		cache with this allocation.
- *
- *		Note that if f->shared->alignment > 1, and EOA is not a 
- *		multiple of the alignment, it is possible that performing 
- *		this allocation may generate a fragment of file space in 
- *		addition to the space allocated for the section info.
- *
- *		At present we deal with this by screaming and dying.  
- *		Obviously, this is not acceptatable, but it should do 
- *		for now.
- *
- *		
- * Return:	Success:	non-negative
- *		Failure:	negative
- *
- * Programmer:	John Mainzer
- *		6/6/16
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5FS_alloc_vfd_alloc_hdr_and_section_info(H5F_t *f, hid_t dxpl_id, 
-    H5FS_t *fspace, haddr_t *fs_addr_ptr)
-{
-    herr_t ret_value = SUCCEED;         /* Return value */
-
-    FUNC_ENTER_NOAPI_TAG(dxpl_id, H5AC__FREESPACE_TAG, FAIL)
-
-    /* Check arguments */
-    HDassert(f);
-    HDassert(fspace);
-    HDassert(fs_addr_ptr);
-
-    /* The section info should be unlocked */
-    HDassert(fspace->sinfo_lock_count == 0);
-
-    /* No space should be allocated */
-    HDassert(*fs_addr_ptr == HADDR_UNDEF);
-    HDassert(fspace->addr == HADDR_UNDEF);
-    HDassert(fspace->sect_addr == HADDR_UNDEF);
-    HDassert(fspace->alloc_sect_size == 0);
-
-    /* Check if any space will be needed */
-    if(fspace->serial_sect_count > 0) {
-        haddr_t sect_addr;      /* Address of sinfo */
-
-        /* The section info is floating, so fspace->sinfo should be defined */
-        HDassert(fspace->sinfo);
-
-        /* Start by allocating file space for the header */
-        if(HADDR_UNDEF == (fspace->addr = H5MF_vfd_alloc(f, dxpl_id, H5FD_MEM_FSPACE_HDR,
-                (hsize_t)H5FS_HEADER_SIZE(f), FALSE)))
-            HGOTO_ERROR(H5E_FSPACE, H5E_CANTALLOC, FAIL, "can't allocate file space for hdr")
-
-        /* Cache the new free space header (pinned) */
-        if(H5AC_insert_entry(f, dxpl_id, H5AC_FSPACE_HDR, fspace->addr, fspace, H5AC__PIN_ENTRY_FLAG) < 0)
-            HGOTO_ERROR(H5E_FSPACE, H5E_CANTINSERT, FAIL, "can't add free space header to cache")
-
-
-        /* Now allocate file space for the section info */
-        if(HADDR_UNDEF == (sect_addr = H5MF_vfd_alloc(f, dxpl_id, H5FD_MEM_FSPACE_SINFO,
-                fspace->sect_size, FALSE)))
-            HGOTO_ERROR(H5E_FSPACE, H5E_CANTALLOC, FAIL, "can't allocate file space")
-
-        /* Update fspace->alloc_sect_size and fspace->sect_addr to reflect 
-         * the allocation 
-         */
-        fspace->alloc_sect_size = fspace->sect_size;
-        fspace->sect_addr = sect_addr;
-
-        /* We have changed the sinfo address -- Mark free space header dirty */
-        if(H5AC_mark_entry_dirty(fspace) < 0)
-            HGOTO_ERROR(H5E_FSPACE, H5E_CANTMARKDIRTY, FAIL, "unable to mark free space header as dirty")
-
-        /* Insert the new section info into the metadata cache.  */
-
-        /* Question: Do we need to worry about this insertion causing an 
-         * eviction from the metadata cache?  Think on this.  If so, add a 
-         * flag to H5AC_insert() to force it to skip the call to make space in
-         * cache.
-         *
-         * On reflection, no.
-         *
-         * On a regular file close, any eviction will not change the 
-         * the contents of the free space manger(s), as all entries 
-         * should have correct file space allocated by the time this 
-         * function is called.
-         *
-         * In the cache image case, the selection of entries for inclusion
-         * in the cache image will not take place until after this call.
-         * (Recall that this call is made during the metadata fsm settle
-         * routine, which is called during the serialization routine in 
-         * the cache image case.  Entries are not selected for inclusion
-         * in the image until after the cache is serialized.)  
-         *
-         *                                        JRM -- 11/4/16
-         */
-        if(H5AC_insert_entry(f, dxpl_id, H5AC_FSPACE_SINFO, sect_addr, fspace->sinfo, H5AC__NO_FLAGS_SET) < 0)
-            HGOTO_ERROR(H5E_FSPACE, H5E_CANTINSERT, FAIL, "can't add free space sinfo to cache")
-
-        /* Since space has been allocated for the section info and the sinfo
-         * has been inserted into the cache, relinquish owership (i.e. float)
-         * the section info.
-         */
-        fspace->sinfo = NULL;
-
-        /* Set the address of the free space header, on success */
-        *fs_addr_ptr = fspace->addr;
-    } /* end if */
-
-done:
-    FUNC_LEAVE_NOAPI_TAG(ret_value, FAIL)
-} /* H5FS_alloc_vfd_alloc_hdr_and_section_info() */
-
-
-/*-------------------------------------------------------------------------
  * Function:    H5FS_free()
  *
  * Purpose:     Free space for free-space manager header and section info header
@@ -1076,7 +910,7 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5FS_free(H5F_t *f, H5FS_t *fspace, hid_t dxpl_id)
+H5FS_free(H5F_t *f, H5FS_t *fspace, hid_t dxpl_id, hbool_t free_file_space)
 {
     haddr_t	saved_addr;             /* Previous address of item */
     unsigned    cache_flags;        /* Flags for unprotecting cache entries */
@@ -1123,7 +957,8 @@ H5FS_free(H5F_t *f, H5FS_t *fspace, hid_t dxpl_id)
 
         /* Free space for the free-space manager section info */
         if(!H5F_IS_TMP_ADDR(f, saved_addr)) {
-            if(H5MF_xfree(f, H5FD_MEM_FSPACE_SINFO, dxpl_id, saved_addr, saved_size) < 0)
+            if(free_file_space &&
+               H5MF_xfree(f, H5FD_MEM_FSPACE_SINFO, dxpl_id, saved_addr, saved_size) < 0)
                 HGOTO_ERROR(H5E_FSPACE, H5E_CANTFREE, FAIL, "unable to release free space sections")
         } /* end if */
 
@@ -1165,7 +1000,8 @@ H5FS_free(H5F_t *f, H5FS_t *fspace, hid_t dxpl_id)
         fspace->addr = HADDR_UNDEF;
 
         /* Free space for the free-space manager header */
-        if(H5MF_xfree(f, H5FD_MEM_FSPACE_HDR, dxpl_id, saved_addr, (hsize_t)H5FS_HEADER_SIZE(f)) < 0)
+        if(free_file_space &&
+           H5MF_xfree(f, H5FD_MEM_FSPACE_HDR, dxpl_id, saved_addr, (hsize_t)H5FS_HEADER_SIZE(f)) < 0)
             HGOTO_ERROR(H5E_FSPACE, H5E_CANTFREE, FAIL, "unable to free free space header")
     } /* end if */
 
@@ -1339,6 +1175,23 @@ done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5FS_sinfo_dest() */
 
+herr_t 
+H5FS_get_sect_count(const H5FS_t *frsp, hsize_t *tot_sect_count)
+{
+    herr_t ret_value = SUCCEED; /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    /* Check arguments. */
+    HDassert(frsp);
+    HDassert(tot_sect_count);
+
+    /* Report statistics for free space */
+    *tot_sect_count = frsp->serial_sect_count;
+
+    FUNC_LEAVE_NOAPI(ret_value)
+}
+
 #ifdef H5FS_DEBUG_ASSERT
 
 /*-------------------------------------------------------------------------
diff --git a/src/H5FScache.c b/src/H5FScache.c
index dcc8122..ddc66fd 100644
--- a/src/H5FScache.c
+++ b/src/H5FScache.c
@@ -37,6 +37,7 @@
 #include "H5private.h"		/* Generic Functions			*/
 #include "H5ACprivate.h"        /* Metadata cache                       */
 #include "H5Eprivate.h"		/* Error handling		  	*/
+#include "H5Fprivate.h"		/* File          			*/
 #include "H5FSpkg.h"		/* File free space			*/
 #include "H5MFprivate.h"	/* File memory management		*/
 #include "H5VMprivate.h"	/* Vectors and arrays 			*/
@@ -296,7 +297,7 @@ H5FS__cache_hdr_deserialize(const void *_image, size_t len, void *_udata,
     /* # of section classes */
     /* (only check if we actually have some classes) */
     UINT16DECODE(image, nclasses);
-    if(fspace->nclasses > 0 && fspace->nclasses != nclasses)
+    if(fspace->nclasses > 0 && nclasses > fspace->nclasses)
         HGOTO_ERROR(H5E_FSPACE, H5E_CANTLOAD, NULL, "section class count mismatch")
 
     /* Shrink percent */
@@ -596,9 +597,11 @@ H5FS__cache_hdr_pre_serialize(H5F_t *f, hid_t dxpl_id, void *_thing,
          * real file space lest the header be written to file with 
          * a nonsense section info address.
          */
-        HDassert(fspace->serial_sect_count > 0);
-        HDassert(fspace->sect_size > 0);
-        HDassert(fspace->alloc_sect_size == (size_t)fspace->sect_size);
+        if(!H5F_POINT_OF_NO_RETURN(f)) {
+            HDassert(fspace->serial_sect_count > 0);
+            HDassert(fspace->sect_size > 0);
+            HDassert(fspace->alloc_sect_size == (size_t)fspace->sect_size);
+        } /* end if */
 
         if(H5F_IS_TMP_ADDR(f, fspace->sect_addr)) {
             unsigned sect_status = 0;
@@ -702,10 +705,12 @@ H5FS__cache_hdr_serialize(const H5F_t *f, void *_image, size_t len,
      * The following asserts are a cursory check on this.
      */
     HDassert((! H5F_addr_defined(fspace->sect_addr)) || (! H5F_IS_TMP_ADDR(f, fspace->sect_addr)));
-    HDassert((! H5F_addr_defined(fspace->sect_addr)) || 
-             ((fspace->serial_sect_count > 0) && 
-              (fspace->sect_size > 0) && 
-              (fspace->alloc_sect_size == (size_t)fspace->sect_size)));
+
+    if(!H5F_POINT_OF_NO_RETURN(f))
+        HDassert((! H5F_addr_defined(fspace->sect_addr)) || 
+                 ((fspace->serial_sect_count > 0) && 
+                  (fspace->sect_size > 0) && 
+                  (fspace->alloc_sect_size == (size_t)fspace->sect_size)));
 
     /* Magic number */
     HDmemcpy(image, H5FS_HDR_MAGIC, (size_t)H5_SIZEOF_MAGIC);
@@ -1061,7 +1066,7 @@ H5FS__cache_sinfo_deserialize(const void *_image, size_t len, void *_udata,
 
                 /* Insert section in free space manager, unless requested not to */
                 if(!(des_flags & H5FS_DESERIALIZE_NO_ADD))
-                    if(H5FS_sect_add(udata->f, udata->dxpl_id, udata->fspace, new_sect, H5FS_ADD_DESERIALIZING, NULL) < 0)
+                    if(H5FS_sect_add(udata->f, udata->dxpl_id, udata->fspace, new_sect, H5FS_ADD_DESERIALIZING, udata) < 0)
                         HGOTO_ERROR(H5E_FSPACE, H5E_CANTINSERT, NULL, "can't add section to free space manager")
             } /* end for */
         } while(image < (((const uint8_t *)_image + old_sect_size) - H5FS_SIZEOF_CHKSUM));
@@ -1177,8 +1182,9 @@ H5FS__cache_sinfo_pre_serialize(H5F_t *f, hid_t dxpl_id, void *_thing,
     HDassert(new_len);
     HDassert(flags);
 
-    /* we shouldn't be called if the section info is empty */
-    HDassert(fspace->serial_sect_count > 0);
+    /* we shouldn't be called if the section info is empty, unless we hit the point of no return. */
+    if(!H5F_POINT_OF_NO_RETURN(f))
+        HDassert(fspace->serial_sect_count > 0);
 
     sinfo_addr = addr; /* this will change if we relocate the section data */
 
diff --git a/src/H5FSpkg.h b/src/H5FSpkg.h
index 4411236..ab97955 100644
--- a/src/H5FSpkg.h
+++ b/src/H5FSpkg.h
@@ -187,8 +187,9 @@ struct H5FS_t {
                                 /* must be either H5C__NO_FLAGS_SET (i.e r/w)  */
 				/* or H5AC__READ_ONLY_FLAG (i.e. r/o).         */
     size_t max_cls_serial_size; /* Max. additional size of serialized form of section */
-    hsize_t    threshold;      	/* Threshold for alignment              */
     hsize_t    alignment;      	/* Alignment                            */
+    hsize_t    align_thres;     /* Threshold for alignment              */
+
 
 /* Memory data structures (not stored directly) */
     H5FS_section_class_t *sect_cls; /* Array of section classes for this free list */
diff --git a/src/H5FSprivate.h b/src/H5FSprivate.h
index 1816a6e..74f9dcb 100644
--- a/src/H5FSprivate.h
+++ b/src/H5FSprivate.h
@@ -67,6 +67,12 @@
                                          *      managed sections is in flux)
                                          */
 
+#define H5FS_PAGE_END_NO_ADD    0x08    /* For "small" page fs:
+                                         * Don't add section to free space:
+                                         * 	when the section is at page end and
+                                         * 	when the section size is <= "small"
+                                         */
+
 /* Flags for deserialize callback  */
 #define H5FS_DESERIALIZE_NO_ADD  0x01   /* Don't add section to free space
                                          *      manager after it's deserialized
@@ -98,11 +104,11 @@ typedef struct H5FS_section_class_t {
     herr_t (*term_cls)(struct H5FS_section_class_t *);                  /* Routine to terminate class-specific settings */
 
     /* Object methods */
-    herr_t (*add)(H5FS_section_info_t *, unsigned *, void *);       /* Routine called when section is about to be added to manager */
+    herr_t (*add)(H5FS_section_info_t **, unsigned *, void *);       /* Routine called when section is about to be added to manager */
     herr_t (*serialize)(const struct H5FS_section_class_t *, const H5FS_section_info_t *, uint8_t *);        /* Routine to serialize a "live" section into a buffer */
     H5FS_section_info_t *(*deserialize)(const struct H5FS_section_class_t *, hid_t dxpl_id, const uint8_t *, haddr_t, hsize_t, unsigned *);     /* Routine to deserialize a buffer into a "live" section */
     htri_t (*can_merge)(const H5FS_section_info_t *, const H5FS_section_info_t *, void *);  /* Routine to determine if two nodes are mergable */
-    herr_t (*merge)(H5FS_section_info_t *, H5FS_section_info_t *, void *);      /* Routine to merge two nodes */
+    herr_t (*merge)(H5FS_section_info_t **, H5FS_section_info_t *, void *);      /* Routine to merge two nodes */
     htri_t (*can_shrink)(const H5FS_section_info_t *, void *);        /* Routine to determine if node can shrink container */
     herr_t (*shrink)(H5FS_section_info_t **, void *);   /* Routine to shrink container */
     herr_t (*free)(H5FS_section_info_t *);              /* Routine to free node */
@@ -182,9 +188,8 @@ H5_DLL herr_t H5FS_delete(H5F_t *f, hid_t dxpl_id, haddr_t fs_addr);
 H5_DLL herr_t H5FS_close(H5F_t *f, hid_t dxpl_id, H5FS_t *fspace);
 H5_DLL herr_t H5FS_alloc_hdr(H5F_t *f, H5FS_t *fspace, haddr_t *fs_addr, hid_t dxpl_id);
 H5_DLL herr_t H5FS_alloc_sect(H5F_t *f, H5FS_t *fspace, hid_t dxpl_id);
-H5_DLL herr_t H5FS_alloc_vfd_alloc_hdr_and_section_info(H5F_t *f, hid_t dxpl_id, 
-    H5FS_t *fspace, haddr_t *fs_addr_ptr);
-H5_DLL herr_t H5FS_free(H5F_t *f, H5FS_t *fspace, hid_t dxpl_id);
+H5_DLL herr_t H5FS_free(H5F_t *f, H5FS_t *fspace, hid_t dxpl_id, 
+    hbool_t free_file_space);
 
 /* Free space section routines */
 H5_DLL herr_t H5FS_sect_add(H5F_t *f, hid_t dxpl_id, H5FS_t *fspace,
@@ -192,7 +197,7 @@ H5_DLL herr_t H5FS_sect_add(H5F_t *f, hid_t dxpl_id, H5FS_t *fspace,
 H5_DLL htri_t H5FS_sect_try_merge(H5F_t *f, hid_t dxpl_id, H5FS_t *fspace,
     H5FS_section_info_t *sect, unsigned flags, void *op_data);
 H5_DLL htri_t H5FS_sect_try_extend(H5F_t *f, hid_t dxpl_id, H5FS_t *fspace,
-    haddr_t addr, hsize_t size, hsize_t extra_requested);
+    haddr_t addr, hsize_t size, hsize_t extra_requested, unsigned flags, void *op_data);
 H5_DLL herr_t H5FS_sect_remove(H5F_t *f, hid_t dxpl_id, H5FS_t *fspace,
     H5FS_section_info_t *node);
 H5_DLL htri_t H5FS_sect_find(H5F_t *f, hid_t dxpl_id, H5FS_t *fspace,
@@ -202,11 +207,18 @@ H5_DLL herr_t H5FS_sect_stats(const H5FS_t *fspace, hsize_t *tot_space,
     hsize_t *nsects);
 H5_DLL herr_t H5FS_sect_change_class(H5F_t *f, hid_t dxpl_id, H5FS_t *fspace,
     H5FS_section_info_t *sect, uint16_t new_class);
-H5_DLL htri_t H5FS_sect_try_shrink_eoa(const H5F_t *f, hid_t dxpl_id, const H5FS_t *fspace, void *op_data);
-H5_DLL herr_t H5FS_sect_query_last_sect(const H5FS_t *fspace, haddr_t *sect_addr, hsize_t *sect_size);
+H5_DLL htri_t H5FS_sect_try_shrink_eoa(H5F_t *f, hid_t dxpl_id, H5FS_t *fspace,
+    void *op_data);
 
 /* Statistics routine */
 H5_DLL herr_t H5FS_stat_info(const H5F_t *f, const H5FS_t *frsp, H5FS_stat_t *stats);
+H5_DLL herr_t H5FS_get_sect_count(const H5FS_t *frsp, hsize_t *tot_sect_count);
+
+/* free space manager settling routines */
+H5_DLL herr_t H5FS_vfd_alloc_hdr_and_section_info_if_needed(H5F_t *f,
+                                                          hid_t dxpl_id,
+                                                          H5FS_t *fspace,
+                                                          haddr_t *fs_addr_ptr);
 
 /* Debugging routines for dumping file structures */
 H5_DLL herr_t H5FS_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr,
diff --git a/src/H5FSsection.c b/src/H5FSsection.c
index efe0031..49ff003 100644
--- a/src/H5FSsection.c
+++ b/src/H5FSsection.c
@@ -25,6 +25,8 @@
 /* Module Setup */
 /****************/
 
+#define H5F_FRIEND              /*suppress error about including H5Fpkg   */
+
 #include "H5FSmodule.h"         /* This source code file is part of the H5FS module */
 
 
@@ -33,6 +35,7 @@
 /***********/
 #include "H5private.h"		/* Generic Functions			*/
 #include "H5Eprivate.h"		/* Error handling		  	*/
+#include "H5Fpkg.h"             /* File access                          */
 #include "H5FSpkg.h"		/* File free space			*/
 #include "H5MFprivate.h"	/* File memory management		*/
 #include "H5VMprivate.h"		/* Vectors and arrays 			*/
@@ -1210,11 +1213,13 @@ H5FS_sect_merge(H5FS_t *fspace, H5FS_section_info_t **sect, void *op_data)
                             HGOTO_ERROR(H5E_FSPACE, H5E_CANTRELEASE, FAIL, "can't remove section from internal data structures")
 
                         /* Merge the two sections together */
-                        if((*tmp_sect_cls->merge)(tmp_sect, *sect, op_data) < 0)
+                        if((*tmp_sect_cls->merge)(&tmp_sect, *sect, op_data) < 0)
                             HGOTO_ERROR(H5E_FSPACE, H5E_CANTINSERT, FAIL, "can't merge two sections")
 
                         /* Retarget section pointer to 'less than' node that was merged into */
                         *sect = tmp_sect;
+			if(*sect == NULL) 
+			    HGOTO_DONE(ret_value);
 
                         /* Indicate successful merge occurred */
                         modified = TRUE;
@@ -1254,9 +1259,13 @@ H5FS_sect_merge(H5FS_t *fspace, H5FS_section_info_t **sect, void *op_data)
                             HGOTO_ERROR(H5E_FSPACE, H5E_CANTRELEASE, FAIL, "can't remove section from internal data structures")
 
                         /* Merge the two sections together */
-                        if((*sect_cls->merge)(*sect, tmp_sect, op_data) < 0)
+                        if((*sect_cls->merge)(sect, tmp_sect, op_data) < 0)
                             HGOTO_ERROR(H5E_FSPACE, H5E_CANTINSERT, FAIL, "can't merge two sections")
 
+                        /* It's possible that the merge caused the section to be deleted (particularly in the paged allocation case) */
+                        if(*sect == NULL) 
+                            HGOTO_DONE(ret_value);
+
                         /* Indicate successful merge occurred */
                         modified = TRUE;
                     } /* end if */
@@ -1383,7 +1392,7 @@ HDfprintf(stderr, "%s: *sect = {%a, %Hu, %u, %s}\n", FUNC, sect->addr, sect->siz
     /* Call "add" section class callback, if there is one */
     cls = &fspace->sect_cls[sect->type];
     if(cls->add) {
-        if((*cls->add)(sect, &flags, op_data) < 0)
+        if((*cls->add)(&sect, &flags, op_data) < 0)
             HGOTO_ERROR(H5E_FSPACE, H5E_CANTINSERT, FAIL, "'add' section class callback failed")
     } /* end if */
 
@@ -1411,7 +1420,7 @@ HDfprintf(stderr, "%s: fspace->tot_space = %Hu\n", FUNC, fspace->tot_space);
 #endif /* H5FS_SINFO_DEBUG */
     /* Mark free space sections as changed */
     /* (if adding sections while deserializing sections, don't set the flag) */
-    if(!(flags & H5FS_ADD_DESERIALIZING))
+    if(!(flags & (H5FS_ADD_DESERIALIZING | H5FS_PAGE_END_NO_ADD)))
         sinfo_modified = TRUE;
 
 done:
@@ -1444,7 +1453,7 @@ HDfprintf(stderr, "%s: Leaving, ret_value = %d\n", FUNC, ret_value);
  */
 htri_t
 H5FS_sect_try_extend(H5F_t *f, hid_t dxpl_id, H5FS_t *fspace, haddr_t addr,
-    hsize_t size, hsize_t extra_requested)
+    hsize_t size, hsize_t extra_requested, unsigned flags, void *op_data)
 {
     hbool_t sinfo_valid = FALSE;        /* Whether the section info is valid */
     hbool_t sinfo_modified = FALSE;     /* Whether the section info was modified */
@@ -1528,10 +1537,16 @@ if(_section_)
                     /* Adjust section by amount requested */
                     sect->addr += extra_requested;
                     sect->size -= extra_requested;
-
-                    /* Re-add adjusted section to free sections data structures */
-                    if(H5FS_sect_link(fspace, sect, 0) < 0)
-                        HGOTO_ERROR(H5E_FSPACE, H5E_CANTINSERT, FAIL, "can't insert free space section into skip list")
+                    if(cls->add)
+                        if((*cls->add)(&sect, &flags, op_data) < 0)
+                            HGOTO_ERROR(H5E_FSPACE, H5E_CANTINSERT, FAIL, "'add' section class callback failed")
+
+                    /* Re-adding the section could cause it to disappear (particularly when paging) */
+                    if(sect) {
+                        /* Re-add adjusted section to free sections data structures */
+                        if(H5FS_sect_link(fspace, sect, 0) < 0)
+                            HGOTO_ERROR(H5E_FSPACE, H5E_CANTINSERT, FAIL, "can't insert free space section into skip list")
+                    } /* end if */
                 } /* end if */
                 else {
                     /* Sanity check */
@@ -1667,7 +1682,7 @@ HDfprintf(stderr, "%s: fspace->sinfo->nbins = %u\n", FUNC, fspace->sinfo->nbins)
 HDfprintf(stderr, "%s: bin = %u\n", FUNC, bin);
 #endif /* QAK */
     alignment = fspace->alignment;
-    if(!((alignment > 1) && (request >= fspace->threshold)))
+    if(!((alignment > 1) && (request >= fspace->align_thres)))
         alignment = 0; /* no alignment */
 
     do {
@@ -2349,7 +2364,7 @@ HDfprintf(stderr, "%s: sect->size = %Hu, sect->addr = %a, sect->type = %u\n", "H
  *-------------------------------------------------------------------------
  */
 htri_t
-H5FS_sect_try_shrink_eoa(const H5F_t *f, hid_t dxpl_id, const H5FS_t *fspace, void *op_data)
+H5FS_sect_try_shrink_eoa(H5F_t *f, hid_t dxpl_id, H5FS_t *fspace, void *op_data)
 {
     hbool_t sinfo_valid = FALSE;        /* Whether the section info is valid */
     hbool_t section_removed = FALSE;    /* Whether a section was removed */
@@ -2406,42 +2421,264 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5FS_sect_query_last_sect
- *
- * Purpose:	Retrieve info about the last section on the merge list
- *
- * Return:	Success:	non-negative
- *		Failure:	negative
+ * Function:    H5FS_vfd_alloc_hdr_and_section_info_if_needed
+ *
+ * Purpose:     This function is part of a hack to patch over a design
+ *              flaw in the free space managers for file space allocation.
+ *              Specifically, if a free space manager allocates space for
+ *              its own section info, it is possible for it to
+ *              go into an infinite loop as it:
+ *
+ *                      1) computes the size of the section info
+ *
+ *                      2) allocates file space for the section info
+ *
+ *                      3) notices that the size of the section info
+ *                         has changed
+ *
+ *                      4) deallocates the section info file space and
+ *                         returns to 1) above.
+ *
+ *              Similarly, if it allocates space for its own header, it
+ *              can go into an infinte loop as it:
+ *
+ *                      1) allocates space for the header
+ *
+ *                      2) notices that the free space manager is empty
+ *                         and thus should not have file space allocated
+ *                         to its header
+ *
+ *                      3) frees the space allocated to the header
+ *
+ *                      4) notices that the free space manager is not
+ *                         empty and thus must have file space allocated
+ *                         to it, and thus returns to 1) above.
+ *
+ *              In a nutshell, the solution applied in this hack is to
+ *              deallocate file space for the free space manager(s) that
+ *              handle FSM header and/or section info file space allocations,
+ *              wait until all other allocation/deallocation requests have
+ *              been handled, and then test to see if the free space manager(s)
+ *              in question are empty.  If they are, do nothing.  If they
+ *              are not, allocate space for them at end of file bypassing the
+ *              usual file space allocation calls, and thus avoiding the
+ *              potential infinite loops.
+ *
+ *              The purpose of this function is to allocate file space for
+ *              the header and section info of the target free space manager
+ *              directly from the VFD if needed.  In this case the function
+ *              also re-inserts the header and section info in the metadata
+ *              cache with this allocation.
+ *
+ *		When paged allocation is not enabled, allocation of space 
+ *		for the free space manager header and section info is 
+ *		straight forward -- we simply allocate the space directly 
+ *		from file driver.
+ *
+ *              Note that if f->shared->alignment > 1, and EOA is not a
+ *              multiple of the alignment, it is possible that performing
+ *              these allocations may generate a fragment of file space in
+ *              addition to the space allocated for the section info.  This
+ *		excess space is dropped on the floor.  As shall be seen,
+ *		it will usually be reclaimed later.
+ *
+ *		When page allocation is enabled, things are more difficult,
+ *		as there is the possibility that page buffering will be 
+ *		enabled when the free space managers are read.  To allow
+ *		for this, we must ensure that space allocated for the 
+ *		free space manager header and section info is either larger
+ *		than a page, or resides completely withing a page.
+ *
+ *		Do this by allocating space for the free space header and 
+ *		section info starting at page boundaries, and extending 
+ *		allocation to the next page boundary.  This of course wastes
+ *		space, but see below.
+ *
+ *              On the first free space allocation / deallocation after the 
+ *		next file open, we will read the self referential free space 
+ *		managers, float them and reduce the EOA to its value prior 
+ *		to allocation of file space for the self referential free 
+ *              space managers on the preceeding file close.  This EOA value 
+ *		is stored in the free space manager superblock extension 
+ *		message.
+ *
+ * Return:      Success:        non-negative
+ *              Failure:        negative
  *
- * Programmer:	Vailin Choi
+ * Programmer:  John Mainzer
+ *              6/6/16
  *
  *-------------------------------------------------------------------------
  */
 herr_t
-H5FS_sect_query_last_sect(const H5FS_t *fspace, haddr_t *sect_addr, hsize_t *sect_size)
+H5FS_vfd_alloc_hdr_and_section_info_if_needed(H5F_t *f, hid_t dxpl_id,
+    H5FS_t *fspace, haddr_t *fs_addr_ptr)
 {
-    FUNC_ENTER_NOAPI_NOINIT_NOERR
+    hsize_t	hdr_alloc_size;
+    hsize_t	sinfo_alloc_size;
+    haddr_t     sect_addr = HADDR_UNDEF;        /* address of sinfo */
+    haddr_t     eoa_frag_addr = HADDR_UNDEF;    /* Address of fragment at EOA */
+    hsize_t     eoa_frag_size = 0;      /* Size of fragment at EOA */
+    haddr_t     eoa = HADDR_UNDEF;      /* Initial EOA for the file */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT
 
     /* Check arguments. */
+    HDassert(f);
+    HDassert(f->shared);
+    HDassert(f->shared->lf);
     HDassert(fspace);
+    HDassert(fs_addr_ptr);
 
-    if(fspace->sinfo && fspace->sinfo->merge_list) {
-        H5SL_node_t *last_node;             /* Last node in merge list */
+    /* the section info should be unlocked */
+    HDassert(fspace->sinfo_lock_count == 0);
 
-        /* Check for last node in the merge list */
-        if(NULL != (last_node = H5SL_last(fspace->sinfo->merge_list))) {
-            H5FS_section_info_t *tmp_sect;      /* Temporary free space section */
+    /* no space should be allocated */
+    HDassert(*fs_addr_ptr == HADDR_UNDEF);
+    HDassert(fspace->addr == HADDR_UNDEF);
+    HDassert(fspace->sect_addr == HADDR_UNDEF);
+    HDassert(fspace->alloc_sect_size == 0);
 
-            /* Get the pointer to the last section, from the last node */
-            tmp_sect = (H5FS_section_info_t *)H5SL_item(last_node);
-            HDassert(tmp_sect);
-	    if(sect_addr)
-                *sect_addr = tmp_sect->addr;
-	    if(sect_size)
-                *sect_size = tmp_sect->size;
-	} /* end if */
+    /* persistant free space managers must be enabled */
+    HDassert(f->shared->fs_persist);
+
+    /* At present, all free space strategies enable the free space managers.
+     * This will probably change -- at which point this assertion should 
+     * be revisited.
+     */
+    /* Updated: Only the following two strategies enable the free-space managers */
+    HDassert((f->shared->fs_strategy == H5F_FSPACE_STRATEGY_FSM_AGGR) ||
+             (f->shared->fs_strategy == H5F_FSPACE_STRATEGY_PAGE));
+
+    if(fspace->serial_sect_count > 0) {
+        /* the section info is floating, so space->sinfo should be defined */
+        HDassert(fspace->sinfo);
+
+        /* start by allocating file space for the header */
+
+        /* Get the EOA for the file -- need for sanity check below */
+        if(HADDR_UNDEF == (eoa = H5F_get_eoa(f, H5FD_MEM_FSPACE_HDR)))
+           HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "Unable to get eoa")
+
+        /* check for overlap into temporary allocation space */
+        if(H5F_IS_TMP_ADDR(f, (eoa + fspace->sect_size)))
+            HGOTO_ERROR(H5E_RESOURCE, H5E_BADRANGE, FAIL, "hdr file space alloc will overlap into 'temporary' file space")
+
+	hdr_alloc_size = H5FS_HEADER_SIZE(f);
+
+	/* if page allocation is enabled, extend the hdr_alloc_size to the 
+	 * next page boundary.
+         */
+        if(H5F_PAGED_AGGR(f)) {
+            HDassert(0 == (eoa % f->shared->fs_page_size));
+
+	    hdr_alloc_size = ((hdr_alloc_size / f->shared->fs_page_size) + 1) * f->shared->fs_page_size;
+
+            HDassert(hdr_alloc_size >= H5FS_HEADER_SIZE(f));
+            HDassert((hdr_alloc_size % f->shared->fs_page_size) == 0);
+        } /* end if */
+
+        /* allocate space for the hdr */
+        if(HADDR_UNDEF == (fspace->addr = H5FD_alloc(f->shared->lf, dxpl_id,
+                                                   H5FD_MEM_FSPACE_HDR, f, 
+                                                   hdr_alloc_size,
+                                                   &eoa_frag_addr,
+                                                   &eoa_frag_size)))
+            HGOTO_ERROR(H5E_FSPACE, H5E_CANTALLOC, FAIL, "can't allocate file space for hdr")
+
+        /* if the file alignement is 1, there should be no
+         * eoa fragment.  Otherwise, drop any fragment on the floor.
+         */
+        HDassert((eoa_frag_size == 0) || (f->shared->alignment != 1));
+
+        /* Cache the new free space header (pinned) */
+        if(H5AC_insert_entry(f, dxpl_id, H5AC_FSPACE_HDR, fspace->addr, fspace, H5AC__PIN_ENTRY_FLAG) < 0)
+            HGOTO_ERROR(H5E_FSPACE, H5E_CANTINIT, FAIL, "can't add free space header to cache")
+
+        *fs_addr_ptr = fspace->addr;
+
+        /* now allocate file space for the section info */
+
+        /* Get the EOA for the file -- need for sanity check below */
+        if(HADDR_UNDEF == (eoa = H5F_get_eoa(f, H5FD_MEM_FSPACE_SINFO)))
+            HGOTO_ERROR(H5E_FSPACE, H5E_CANTGET, FAIL, "Unable to get eoa")
+
+        /* check for overlap into temporary allocation space */
+        if(H5F_IS_TMP_ADDR(f, (eoa + fspace->sect_size)))
+            HGOTO_ERROR(H5E_FSPACE, H5E_BADRANGE, FAIL, "sinfo file space alloc will overlap into 'temporary' file space")
+
+        sinfo_alloc_size = fspace->sect_size;
+
+	/* if paged allocation is enabled, extend the sinfo_alloc_size to the 
+	 * next page boundary.
+         */
+        if(H5F_PAGED_AGGR(f)) {
+            HDassert(0 == (eoa % f->shared->fs_page_size));
+
+	    sinfo_alloc_size = ((sinfo_alloc_size / f->shared->fs_page_size) + 1) * f->shared->fs_page_size;
+
+            HDassert(sinfo_alloc_size >= fspace->sect_size);
+            HDassert((sinfo_alloc_size % f->shared->fs_page_size) == 0);
+        } /* end if */
+
+        /* allocate space for the section info */
+        if(HADDR_UNDEF == (sect_addr = H5FD_alloc(f->shared->lf, dxpl_id,
+                                                  H5FD_MEM_FSPACE_SINFO, f, 
+                                                  sinfo_alloc_size,
+                                                  &eoa_frag_addr,
+                                                  &eoa_frag_size)))
+            HGOTO_ERROR(H5E_FSPACE, H5E_CANTALLOC, FAIL, "can't allocate file space")
+
+        /* if the file alignement is 1, there should be no
+         * eoa fragment.  Otherwise, drop the fragment on the floor.
+         */
+        HDassert((eoa_frag_size == 0) || (f->shared->alignment != 1));
+
+        /* update fspace->alloc_sect_size and fspace->sect_addr to reflect
+         * the allocation
+         */
+        fspace->alloc_sect_size = fspace->sect_size;
+        fspace->sect_addr = sect_addr;
+
+        /* insert the new section info into the metadata cache.  */
+
+        /* Question: Do we need to worry about this insertion causing an
+         * eviction from the metadata cache?  Think on this.  If so, add a
+         * flag to H5AC_insert() to force it to skip the call to make space in
+         * cache.
+         *
+         * On reflection, no.
+         *
+         * On a regular file close, any eviction will not change the
+         * the contents of the free space manger(s), as all entries
+         * should have correct file space allocated by the time this
+         * function is called.
+         *
+         * In the cache image case, the selection of entries for inclusion
+         * in the cache image will not take place until after this call.
+         * (Recall that this call is made during the metadata fsm settle
+         * routine, which is called during the serialization routine in
+         * the cache image case.  Entries are not selected for inclusion
+         * in the image until after the cache is serialized.)
+         *
+         *                                        JRM -- 11/4/16
+         */
+        if(H5AC_insert_entry(f, dxpl_id, H5AC_FSPACE_SINFO, sect_addr, fspace->sinfo, H5AC__NO_FLAGS_SET) < 0)
+            HGOTO_ERROR(H5E_FSPACE, H5E_CANTINIT, FAIL, "can't add free space sinfo to cache")
+
+        /* We have changed the sinfo address -- Mark free space header dirty */
+        if(H5AC_mark_entry_dirty(fspace) < 0)
+            HGOTO_ERROR(H5E_FSPACE, H5E_CANTMARKDIRTY, FAIL, "unable to mark free space header as dirty")
+
+        /* since space has been allocated for the section info and the sinfo
+         * has been inserted into the cache, relinquish owership (i.e. float)
+         * the section info.
+         */
+        fspace->sinfo = NULL;
     } /* end if */
 
-    FUNC_LEAVE_NOAPI(SUCCEED)
-} /* H5FS_sect_query_last_sect() */
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5FS_vfd_alloc_hdr_and_section_info_if_needed() */
 
diff --git a/src/H5Faccum.c b/src/H5Faccum.c
index 48f9bdd..7f3bb39 100644
--- a/src/H5Faccum.c
+++ b/src/H5Faccum.c
@@ -112,18 +112,25 @@ H5FL_BLK_DEFINE_STATIC(meta_accum);
  *-------------------------------------------------------------------------
  */
 herr_t
-H5F__accum_read(const H5F_io_info_t *fio_info, H5FD_mem_t map_type, haddr_t addr,
+H5F__accum_read(const H5F_io_info2_t *fio_info, H5FD_mem_t map_type, haddr_t addr,
     size_t size, void *buf/*out*/)
 {
+    H5FD_io_info_t fdio_info;           /* File driver I/O info */
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_PACKAGE
 
     HDassert(fio_info);
     HDassert(fio_info->f);
-    HDassert(fio_info->dxpl);
+    HDassert(fio_info->meta_dxpl);
+    HDassert(fio_info->raw_dxpl);
     HDassert(buf);
 
+    /* Translate to file driver I/O info object */
+    fdio_info.file = fio_info->f->shared->lf;
+    fdio_info.meta_dxpl = fio_info->meta_dxpl;
+    fdio_info.raw_dxpl = fio_info->raw_dxpl;
+
     /* Check if this information is in the metadata accumulator */
     if((fio_info->f->shared->feature_flags & H5FD_FEAT_ACCUMULATE_METADATA) && map_type != H5FD_MEM_DRAW) {
         H5F_meta_accum_t *accum;     /* Alias for file's metadata accumulator */
@@ -178,7 +185,7 @@ H5F__accum_read(const H5F_io_info_t *fio_info, H5FD_mem_t map_type, haddr_t addr
                         accum->dirty_off += amount_before;
 
                     /* Dispatch to driver */
-                    if(H5FD_read(fio_info->f->shared->lf, fio_info->dxpl, map_type, addr, amount_before, accum->buf) < 0)
+                    if(H5FD_read(&fdio_info, map_type, addr, amount_before, accum->buf) < 0)
                         HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL, "driver read request failed")
                 } /* end if */
                 else
@@ -192,7 +199,7 @@ H5F__accum_read(const H5F_io_info_t *fio_info, H5FD_mem_t map_type, haddr_t addr
                     H5_CHECKED_ASSIGN(amount_after, size_t, ((addr + size) - (accum->loc + accum->size)), hsize_t);
 
                     /* Dispatch to driver */
-                    if(H5FD_read(fio_info->f->shared->lf, fio_info->dxpl, map_type, (accum->loc + accum->size), amount_after, (accum->buf + accum->size + amount_before)) < 0)
+                    if(H5FD_read(&fdio_info, map_type, (accum->loc + accum->size), amount_after, (accum->buf + accum->size + amount_before)) < 0)
                         HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL, "driver read request failed")
                 } /* end if */
 
@@ -206,13 +213,13 @@ H5F__accum_read(const H5F_io_info_t *fio_info, H5FD_mem_t map_type, haddr_t addr
             /* Current read doesn't overlap with metadata accumulator, read it from file */
             else {
                 /* Dispatch to driver */
-                if(H5FD_read(fio_info->f->shared->lf, fio_info->dxpl, map_type, addr, size, buf) < 0)
+                if(H5FD_read(&fdio_info, map_type, addr, size, buf) < 0)
                     HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL, "driver read request failed")
             } /* end else */
         } /* end if */
         else {
             /* Read the data */
-            if(H5FD_read(fio_info->f->shared->lf, fio_info->dxpl, map_type, addr, size, buf) < 0)
+            if(H5FD_read(&fdio_info, map_type, addr, size, buf) < 0)
                 HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL, "driver read request failed")
 
             /* Check for overlap w/dirty accumulator */
@@ -255,7 +262,7 @@ H5F__accum_read(const H5F_io_info_t *fio_info, H5FD_mem_t map_type, haddr_t addr
     } /* end if */
     else {
         /* Read the data */
-        if(H5FD_read(fio_info->f->shared->lf, fio_info->dxpl, map_type, addr, size, buf) < 0)
+        if(H5FD_read(&fdio_info, map_type, addr, size, buf) < 0)
             HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL, "driver read request failed")
     } /* end else */
 
@@ -278,7 +285,7 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F__accum_adjust(H5F_meta_accum_t *accum, const H5F_io_info_t *fio_info,
+H5F__accum_adjust(H5F_meta_accum_t *accum, const H5FD_io_info_t *fdio_info,
     H5F_accum_adjust_t adjust, size_t size)
 {
     herr_t      ret_value = SUCCEED;    /* Return value */
@@ -286,7 +293,7 @@ H5F__accum_adjust(H5F_meta_accum_t *accum, const H5F_io_info_t *fio_info,
     FUNC_ENTER_STATIC
 
     HDassert(accum);
-    HDassert(fio_info);
+    HDassert(fdio_info);
     HDassert(H5F_ACCUM_APPEND == adjust || H5F_ACCUM_PREPEND == adjust);
     HDassert(size > 0);
     HDassert(size <= H5F_ACCUM_MAX_SIZE);
@@ -344,7 +351,7 @@ H5F__accum_adjust(H5F_meta_accum_t *accum, const H5F_io_info_t *fio_info,
                     /* Check if the dirty region overlaps the region to eliminate from the accumulator */
                     if((accum->size - shrink_size) < (accum->dirty_off + accum->dirty_len)) {
                         /* Write out the dirty region from the metadata accumulator, with dispatch to driver */
-                        if(H5FD_write(fio_info->f->shared->lf, fio_info->dxpl, H5FD_MEM_DEFAULT, (accum->loc + accum->dirty_off), accum->dirty_len, (accum->buf + accum->dirty_off)) < 0)
+                        if(H5FD_write(fdio_info, H5FD_MEM_DEFAULT, (accum->loc + accum->dirty_off), accum->dirty_len, (accum->buf + accum->dirty_off)) < 0)
                             HGOTO_ERROR(H5E_FILE, H5E_WRITEERROR, FAIL, "file write failed")
 
                         /* Reset accumulator dirty flag */
@@ -355,7 +362,7 @@ H5F__accum_adjust(H5F_meta_accum_t *accum, const H5F_io_info_t *fio_info,
                     /* Check if the dirty region overlaps the region to eliminate from the accumulator */
                     if(shrink_size > accum->dirty_off) {
                         /* Write out the dirty region from the metadata accumulator, with dispatch to driver */
-                        if(H5FD_write(fio_info->f->shared->lf, fio_info->dxpl, H5FD_MEM_DEFAULT, (accum->loc + accum->dirty_off), accum->dirty_len, (accum->buf + accum->dirty_off)) < 0)
+                        if(H5FD_write(fdio_info, H5FD_MEM_DEFAULT, (accum->loc + accum->dirty_off), accum->dirty_len, (accum->buf + accum->dirty_off)) < 0)
                             HGOTO_ERROR(H5E_FILE, H5E_WRITEERROR, FAIL, "file write failed")
 
                         /* Reset accumulator dirty flag */
@@ -417,9 +424,10 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5F__accum_write(const H5F_io_info_t *fio_info, H5FD_mem_t map_type, haddr_t addr,
+H5F__accum_write(const H5F_io_info2_t *fio_info, H5FD_mem_t map_type, haddr_t addr,
     size_t size, const void *buf)
 {
+    H5FD_io_info_t fdio_info;           /* File driver I/O info */
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
@@ -427,9 +435,15 @@ H5F__accum_write(const H5F_io_info_t *fio_info, H5FD_mem_t map_type, haddr_t add
     HDassert(fio_info);
     HDassert(fio_info->f);
     HDassert(H5F_INTENT(fio_info->f) & H5F_ACC_RDWR);
-    HDassert(fio_info->dxpl);
+    HDassert(fio_info->meta_dxpl);
+    HDassert(fio_info->raw_dxpl);
     HDassert(buf);
 
+    /* Translate to file driver I/O info object */
+    fdio_info.file = fio_info->f->shared->lf;
+    fdio_info.meta_dxpl = fio_info->meta_dxpl;
+    fdio_info.raw_dxpl = fio_info->raw_dxpl;
+
     /* Check for accumulating metadata */
     if((fio_info->f->shared->feature_flags & H5FD_FEAT_ACCUMULATE_METADATA) && map_type != H5FD_MEM_DRAW) {
         H5F_meta_accum_t *accum;     /* Alias for file's metadata accumulator */
@@ -446,7 +460,7 @@ H5F__accum_write(const H5F_io_info_t *fio_info, H5FD_mem_t map_type, haddr_t add
                 /* Check if the new metadata adjoins the beginning of the current accumulator */
                 if((addr + size) == accum->loc) {
                     /* Check if we need to adjust accumulator size */
-                    if(H5F__accum_adjust(accum, fio_info, H5F_ACCUM_PREPEND, size) < 0)
+                    if(H5F__accum_adjust(accum, &fdio_info, H5F_ACCUM_PREPEND, size) < 0)
                         HGOTO_ERROR(H5E_IO, H5E_CANTRESIZE, FAIL, "can't adjust metadata accumulator")
 
                     /* Move the existing metadata to the proper location */
@@ -471,7 +485,7 @@ H5F__accum_write(const H5F_io_info_t *fio_info, H5FD_mem_t map_type, haddr_t add
                 /* Check if the new metadata adjoins the end of the current accumulator */
                 else if(addr == (accum->loc + accum->size)) {
                     /* Check if we need to adjust accumulator size */
-                    if(H5F__accum_adjust(accum, fio_info, H5F_ACCUM_APPEND, size) < 0)
+                    if(H5F__accum_adjust(accum, &fdio_info, H5F_ACCUM_APPEND, size) < 0)
                         HGOTO_ERROR(H5E_IO, H5E_CANTRESIZE, FAIL, "can't adjust metadata accumulator")
 
                     /* Copy the new metadata to the end */
@@ -531,7 +545,7 @@ H5F__accum_write(const H5F_io_info_t *fio_info, H5FD_mem_t map_type, haddr_t add
                         H5_CHECKED_ASSIGN(add_size, size_t, (accum->loc - addr), hsize_t);
 
                         /* Check if we need to adjust accumulator size */
-                        if(H5F__accum_adjust(accum, fio_info, H5F_ACCUM_PREPEND, add_size) < 0)
+                        if(H5F__accum_adjust(accum, &fdio_info, H5F_ACCUM_PREPEND, add_size) < 0)
                             HGOTO_ERROR(H5E_IO, H5E_CANTRESIZE, FAIL, "can't adjust metadata accumulator")
 
                         /* Calculate the proper offset of the existing metadata */
@@ -571,7 +585,7 @@ H5F__accum_write(const H5F_io_info_t *fio_info, H5FD_mem_t map_type, haddr_t add
                         H5_CHECKED_ASSIGN(add_size, size_t, (addr + size) - (accum->loc + accum->size), hsize_t);
 
                         /* Check if we need to adjust accumulator size */
-                        if(H5F__accum_adjust(accum, fio_info, H5F_ACCUM_APPEND, add_size) < 0)
+                        if(H5F__accum_adjust(accum, &fdio_info, H5F_ACCUM_APPEND, add_size) < 0)
                             HGOTO_ERROR(H5E_IO, H5E_CANTRESIZE, FAIL, "can't adjust metadata accumulator")
 
                         /* Compute offset of dirty region (after adjusting accumulator) */
@@ -637,7 +651,7 @@ H5F__accum_write(const H5F_io_info_t *fio_info, H5FD_mem_t map_type, haddr_t add
                 else {
                     /* Write out the existing metadata accumulator, with dispatch to driver */
                     if(accum->dirty) {
-                        if(H5FD_write(fio_info->f->shared->lf, fio_info->dxpl, H5FD_MEM_DEFAULT, accum->loc + accum->dirty_off, accum->dirty_len, accum->buf + accum->dirty_off) < 0)
+                        if(H5FD_write(&fdio_info, H5FD_MEM_DEFAULT, accum->loc + accum->dirty_off, accum->dirty_len, accum->buf + accum->dirty_off) < 0)
                             HGOTO_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "file write failed")
 
                         /* Reset accumulator dirty flag */
@@ -733,7 +747,7 @@ H5F__accum_write(const H5F_io_info_t *fio_info, H5FD_mem_t map_type, haddr_t add
                     HGOTO_ERROR(H5E_IO, H5E_CANTRESET, FAIL, "can't reset accumulator")
 
             /* Write the data */
-            if(H5FD_write(fio_info->f->shared->lf, fio_info->dxpl, map_type, addr, size, buf) < 0)
+            if(H5FD_write(&fdio_info, map_type, addr, size, buf) < 0)
                 HGOTO_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "file write failed")
 
             /* Check for overlap w/accumulator */
@@ -818,7 +832,7 @@ H5F__accum_write(const H5F_io_info_t *fio_info, H5FD_mem_t map_type, haddr_t add
     } /* end if */
     else {
         /* Write the data */
-        if(H5FD_write(fio_info->f->shared->lf, fio_info->dxpl, map_type, addr, size, buf) < 0)
+        if(H5FD_write(&fdio_info, map_type, addr, size, buf) < 0)
             HGOTO_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "file write failed")
     } /* end else */
 
@@ -842,10 +856,11 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5F__accum_free(const H5F_io_info_t *fio_info, H5FD_mem_t H5_ATTR_UNUSED type, haddr_t addr,
+H5F__accum_free(const H5F_io_info2_t *fio_info, H5FD_mem_t H5_ATTR_UNUSED type, haddr_t addr,
     hsize_t size)
 {
     H5F_meta_accum_t *accum;            /* Alias for file's metadata accumulator */
+    H5FD_io_info_t fdio_info;           /* File driver I/O info */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_PACKAGE
@@ -853,11 +868,17 @@ H5F__accum_free(const H5F_io_info_t *fio_info, H5FD_mem_t H5_ATTR_UNUSED type, h
     /* check arguments */
     HDassert(fio_info);
     HDassert(fio_info->f);
-    HDassert(fio_info->dxpl);
+    HDassert(fio_info->meta_dxpl);
+    HDassert(fio_info->raw_dxpl);
 
     /* Set up alias for file's metadata accumulator info */
     accum = &fio_info->f->shared->accum;
 
+    /* Translate to file driver I/O info object */
+    fdio_info.file = fio_info->f->shared->lf;
+    fdio_info.meta_dxpl = fio_info->meta_dxpl;
+    fdio_info.raw_dxpl = fio_info->raw_dxpl;
+
     /* Adjust the metadata accumulator to remove the freed block, if it overlaps */
     if((fio_info->f->shared->feature_flags & H5FD_FEAT_ACCUMULATE_METADATA)
             && H5F_addr_overlap(addr, size, accum->loc, accum->size)) {
@@ -930,7 +951,7 @@ H5F__accum_free(const H5F_io_info_t *fio_info, H5FD_mem_t H5_ATTR_UNUSED type, h
                     /* Check if block to free is entirely before dirty region */
                     if(H5F_addr_le(tail_addr, dirty_start)) {
                         /* Write out the entire dirty region of the accumulator */
-                        if(H5FD_write(fio_info->f->shared->lf, fio_info->dxpl, H5FD_MEM_DEFAULT, dirty_start, accum->dirty_len, accum->buf + accum->dirty_off) < 0)
+                        if(H5FD_write(&fdio_info, H5FD_MEM_DEFAULT, dirty_start, accum->dirty_len, accum->buf + accum->dirty_off) < 0)
                             HGOTO_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "file write failed")
                     } /* end if */
                     /* Block to free overlaps with some/all of dirty region */
@@ -945,7 +966,7 @@ H5F__accum_free(const H5F_io_info_t *fio_info, H5FD_mem_t H5_ATTR_UNUSED type, h
                         HDassert(write_size > 0);
 
                         /* Write out the unfreed dirty region of the accumulator */
-                        if(H5FD_write(fio_info->f->shared->lf, fio_info->dxpl, H5FD_MEM_DEFAULT, dirty_start + dirty_delta, write_size, accum->buf + accum->dirty_off + dirty_delta) < 0)
+                        if(H5FD_write(&fdio_info, H5FD_MEM_DEFAULT, dirty_start + dirty_delta, write_size, accum->buf + accum->dirty_off + dirty_delta) < 0)
                             HGOTO_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "file write failed")
                     } /* end if */
 
@@ -965,7 +986,7 @@ H5F__accum_free(const H5F_io_info_t *fio_info, H5FD_mem_t H5_ATTR_UNUSED type, h
                         HDassert(write_size > 0);
 
                         /* Write out the unfreed end of the dirty region of the accumulator */
-                        if(H5FD_write(fio_info->f->shared->lf, fio_info->dxpl, H5FD_MEM_DEFAULT, dirty_start + dirty_delta, write_size, accum->buf + accum->dirty_off + dirty_delta) < 0)
+                        if(H5FD_write(&fdio_info, H5FD_MEM_DEFAULT, dirty_start + dirty_delta, write_size, accum->buf + accum->dirty_off + dirty_delta) < 0)
                             HGOTO_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "file write failed")
                     } /* end if */
 
@@ -1006,7 +1027,7 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5F__accum_flush(const H5F_io_info_t *fio_info)
+H5F__accum_flush(const H5F_io_info2_t *fio_info)
 {
     herr_t      ret_value = SUCCEED;    /* Return value */
 
@@ -1014,12 +1035,20 @@ H5F__accum_flush(const H5F_io_info_t *fio_info)
 
     HDassert(fio_info);
     HDassert(fio_info->f);
-    HDassert(fio_info->dxpl);
+    HDassert(fio_info->meta_dxpl);
+    HDassert(fio_info->raw_dxpl);
 
     /* Check if we need to flush out the metadata accumulator */
     if((fio_info->f->shared->feature_flags & H5FD_FEAT_ACCUMULATE_METADATA) && fio_info->f->shared->accum.dirty) {
+        H5FD_io_info_t fdio_info;           /* File driver I/O info */
+
+        /* Translate to file driver I/O info object */
+        fdio_info.file = fio_info->f->shared->lf;
+        fdio_info.meta_dxpl = fio_info->meta_dxpl;
+        fdio_info.raw_dxpl = fio_info->raw_dxpl;
+
         /* Flush the metadata contents */
-        if(H5FD_write(fio_info->f->shared->lf, fio_info->dxpl, H5FD_MEM_DEFAULT, fio_info->f->shared->accum.loc + fio_info->f->shared->accum.dirty_off, fio_info->f->shared->accum.dirty_len, fio_info->f->shared->accum.buf + fio_info->f->shared->accum.dirty_off) < 0)
+        if(H5FD_write(&fdio_info, H5FD_MEM_DEFAULT, fio_info->f->shared->accum.loc + fio_info->f->shared->accum.dirty_off, fio_info->f->shared->accum.dirty_len, fio_info->f->shared->accum.buf + fio_info->f->shared->accum.dirty_off) < 0)
             HGOTO_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "file write failed")
 
         /* Reset the dirty flag */
@@ -1045,7 +1074,7 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5F__accum_reset(const H5F_io_info_t *fio_info, hbool_t flush)
+H5F__accum_reset(const H5F_io_info2_t *fio_info, hbool_t flush)
 {
     herr_t      ret_value = SUCCEED;    /* Return value */
 
@@ -1053,7 +1082,6 @@ H5F__accum_reset(const H5F_io_info_t *fio_info, hbool_t flush)
 
     HDassert(fio_info);
     HDassert(fio_info->f);
-    HDassert(fio_info->dxpl);
 
     /* Flush any dirty data in accumulator, if requested */
     if(flush)
diff --git a/src/H5Fint.c b/src/H5Fint.c
index d122357..794be50 100644
--- a/src/H5Fint.c
+++ b/src/H5Fint.c
@@ -76,8 +76,8 @@ typedef struct H5F_olist_t {
 static int H5F_get_objects_cb(void *obj_ptr, hid_t obj_id, void *key);
 static herr_t H5F_build_actual_name(const H5F_t *f, const H5P_genplist_t *fapl,
     const char *name, char ** /*out*/ actual_name);/* Declare a free list to manage the H5F_t struct */
-static herr_t H5F__flush_phase1(H5F_t *f, hid_t dxpl_id);
-static herr_t H5F__flush_phase2(H5F_t *f, hid_t dxpl_id, hbool_t closing);
+static herr_t H5F__flush_phase1(H5F_t *f, hid_t meta_dxpl_id);
+static herr_t H5F__flush_phase2(H5F_t *f, hid_t meta_dxpl_id, hid_t raw_dxpl_id, hbool_t closing);
 
 
 /*********************/
@@ -182,6 +182,14 @@ H5F_get_access_plist(H5F_t *f, hbool_t app_ref)
         efc_size = H5F_efc_max_nfiles(f->shared->efc);
     if(H5P_set(new_plist, H5F_ACS_EFC_SIZE_NAME, &efc_size) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't set elink file cache size")
+    if(f->shared->page_buf != NULL) {
+        if(H5P_set(new_plist, H5F_ACS_PAGE_BUFFER_SIZE_NAME, &(f->shared->page_buf->max_size)) < 0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't set page buffer size")
+        if(H5P_set(new_plist, H5F_ACS_PAGE_BUFFER_MIN_META_PERC_NAME, &(f->shared->page_buf->min_meta_perc)) < 0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't set minimum metadata fraction of page buffer")
+        if(H5P_set(new_plist, H5F_ACS_PAGE_BUFFER_MIN_RAW_PERC_NAME, &(f->shared->page_buf->min_raw_perc)) < 0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't set minimum raw data fraction of page buffer")
+    } /* end if */
 #ifdef H5_HAVE_PARALLEL
     if(H5P_set(new_plist, H5_COLL_MD_READ_FLAG_NAME, &(f->coll_md_read)) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't set collective metadata read flag")
@@ -495,7 +503,7 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5F_is_hdf5
+ * Function:	H5F__is_hdf5
  *
  * Purpose:	Check the file signature to detect an HDF5 file.
  *
@@ -509,17 +517,14 @@ done:
  *
  * Programmer:	Unknown
  *
- * Modifications:
- *		Robb Matzke, 1999-08-02
- *		Rewritten to use the virtual file layer.
  *-------------------------------------------------------------------------
  */
 htri_t
-H5F_is_hdf5(const char *name, hid_t dxpl_id)
+H5F__is_hdf5(const char *name, hid_t meta_dxpl_id, hid_t raw_dxpl_id)
 {
     H5FD_t	*file = NULL;           /* Low-level file struct */
+    H5FD_io_info_t fdio_info;           /* File driver I/O info */
     haddr_t     sig_addr;               /* Addess of hdf5 file signature */
-    H5P_genplist_t  *xfer_plist= NULL;  /* Dataset transfer property list object */
     htri_t	ret_value = FAIL;       /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
@@ -528,12 +533,15 @@ H5F_is_hdf5(const char *name, hid_t dxpl_id)
     if(NULL == (file = H5FD_open(name, H5F_ACC_RDONLY, H5P_FILE_ACCESS_DEFAULT, HADDR_UNDEF)))
 	HGOTO_ERROR(H5E_IO, H5E_CANTINIT, FAIL, "unable to open file")
 
-    /* Get the property list object */
-    if(NULL == (xfer_plist = (H5P_genplist_t *)H5I_object(dxpl_id)))
+    /* Set up the file driver info */
+    fdio_info.file = file;
+    if(NULL == (fdio_info.meta_dxpl = (H5P_genplist_t *)H5I_object(meta_dxpl_id)))
+        HGOTO_ERROR(H5E_CACHE, H5E_BADATOM, FAIL, "can't get new property list object")
+    if(NULL == (fdio_info.raw_dxpl = (H5P_genplist_t *)H5I_object(raw_dxpl_id)))
         HGOTO_ERROR(H5E_CACHE, H5E_BADATOM, FAIL, "can't get new property list object")
 
     /* The file is an hdf5 file if the hdf5 file signature can be found */
-    if(H5FD_locate_signature(file, xfer_plist, &sig_addr) < 0)
+    if(H5FD_locate_signature(&fdio_info, &sig_addr) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_NOTHDF5, FAIL, "unable to locate file signature")
     ret_value = (HADDR_UNDEF != sig_addr);
 
@@ -544,7 +552,7 @@ done:
             HDONE_ERROR(H5E_IO, H5E_CANTCLOSEFILE, FAIL, "unable to close file")
 
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5F_is_hdf5() */
+} /* end H5F__is_hdf5() */
 
 
 /*-------------------------------------------------------------------------
@@ -597,11 +605,26 @@ H5F_new(H5F_file_t *shared, unsigned flags, hid_t fcpl_id, hid_t fapl_id, H5FD_t
         f->shared->flags = flags;
         f->shared->sohm_addr = HADDR_UNDEF;
         f->shared->sohm_vers = HDF5_SHAREDHEADER_VERSION;
-        for(u = 0; u < NELMTS(f->shared->fs_addr); u++)
-            f->shared->fs_addr[u] = HADDR_UNDEF;
         f->shared->accum.loc = HADDR_UNDEF;
         f->shared->lf = lf;
 
+        /* Initialization for handling file space */
+        for(u = 0; u < NELMTS(f->shared->fs_addr); u++) {
+            f->shared->fs_state[u] = H5F_FS_STATE_CLOSED;
+            f->shared->fs_addr[u] = HADDR_UNDEF;
+            f->shared->fs_man[u] = NULL;
+        } /* end for */
+        f->shared->first_alloc_dealloc = FALSE;
+        f->shared->eoa_pre_fsm_fsalloc = HADDR_UNDEF;
+        f->shared->eoa_post_fsm_fsalloc = HADDR_UNDEF;
+        f->shared->eoa_post_mdci_fsalloc = HADDR_UNDEF;
+
+        /* Initialization for handling file space (for paged aggregation) */
+        f->shared->pgend_meta_thres = H5F_FILE_SPACE_PGEND_META_THRES;
+
+        /* intialize point of no return */
+        f->shared->point_of_no_return = FALSE;
+
         /*
          * Copy the file creation and file access property lists into the
          * new file handle.  We do this early because some values might need
@@ -621,8 +644,19 @@ H5F_new(H5F_file_t *shared, unsigned flags, hid_t fcpl_id, hid_t fapl_id, H5FD_t
         HDassert(f->shared->sohm_nindexes < 255);
         if(H5P_get(plist, H5F_CRT_FILE_SPACE_STRATEGY_NAME, &f->shared->fs_strategy) < 0)
             HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get file space strategy")
+        if(H5P_get(plist, H5F_CRT_FREE_SPACE_PERSIST_NAME, &f->shared->fs_persist) < 0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get file space persisting status")
         if(H5P_get(plist, H5F_CRT_FREE_SPACE_THRESHOLD_NAME, &f->shared->fs_threshold) < 0)
             HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get free-space section threshold")
+        if(H5P_get(plist, H5F_CRT_FILE_SPACE_PAGE_SIZE_NAME, &f->shared->fs_page_size) < 0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get file space page size")
+        HDassert(f->shared->fs_page_size >= H5F_FILE_SPACE_PAGE_SIZE_MIN);
+
+        /* Temporary for multi/split drivers: fail file creation 
+             when persisting free-space or using paged aggregation strategy */
+        if(H5F_HAS_FEATURE(f, H5FD_FEAT_PAGED_AGGR))
+            if(f->shared->fs_strategy == H5F_FSPACE_STRATEGY_PAGE || f->shared->fs_persist)
+                HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't open with this strategy or persistent fs")
 
         /* Get the FAPL values to cache */
         if(NULL == (plist = (H5P_genplist_t *)H5I_object(fapl_id)))
@@ -796,7 +830,7 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5F_dest
+ * Function:	H5F__dest
  *
  * Purpose:	Destroys a file structure.  This function flushes the cache
  *		but doesn't do any other cleanup other than freeing memory
@@ -812,11 +846,11 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5F_dest(H5F_t *f, hid_t dxpl_id, hbool_t flush)
+H5F__dest(H5F_t *f, hid_t meta_dxpl_id, hid_t raw_dxpl_id, hbool_t flush)
 {
     herr_t	   ret_value = SUCCEED;         /* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT
+    FUNC_ENTER_PACKAGE
 
     /* Sanity check */
     HDassert(f);
@@ -824,14 +858,14 @@ H5F_dest(H5F_t *f, hid_t dxpl_id, hbool_t flush)
 
     if(1 == f->shared->nrefs) {
         int actype;                         /* metadata cache type (enum value) */
-        H5F_io_info_t fio_info;             /* I/O info for operation */
+        H5F_io_info2_t fio_info;            /* I/O info for operation */
 
         /* Flush at this point since the file will be closed (phase 1).
          * Only try to flush the file if it was opened with write access, and if
          * the caller requested a flush.
          */
         if((H5F_ACC_RDWR & H5F_INTENT(f)) && flush)
-            if(H5F__flush_phase1(f, dxpl_id) < 0)
+            if(H5F__flush_phase1(f, meta_dxpl_id) < 0)
                 /* Push error, but keep going*/
                 HDONE_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to flush cached data (phase 1)")
 
@@ -839,7 +873,7 @@ H5F_dest(H5F_t *f, hid_t dxpl_id, hbool_t flush)
          * This allows the cache to set up for creating a metadata cache 
          * image if this has been requested.
          */
-        if(H5AC_prep_for_file_close(f, dxpl_id) < 0)
+        if(H5AC_prep_for_file_close(f, meta_dxpl_id) < 0)
             /* Push error, but keep going */
             HDONE_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "metadata cache prep for close failed")
 
@@ -848,7 +882,7 @@ H5F_dest(H5F_t *f, hid_t dxpl_id, hbool_t flush)
          * the caller requested a flush.
          */
         if((H5F_ACC_RDWR & H5F_INTENT(f)) && flush)
-            if(H5F__flush_phase2(f, dxpl_id, TRUE) < 0)
+            if(H5F__flush_phase2(f, meta_dxpl_id, raw_dxpl_id, TRUE) < 0)
                 /* Push error, but keep going */
                 HDONE_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to flush cached data (phase 2)")
 
@@ -895,7 +929,7 @@ H5F_dest(H5F_t *f, hid_t dxpl_id, hbool_t flush)
              *                                          -- JRM
              */
             if(H5F_ACC_RDWR & H5F_INTENT(f)) {
-                if(H5MF_close(f, dxpl_id) < 0)
+                if(H5MF_close(f, meta_dxpl_id) < 0)
                     /* Push error, but keep going*/
                     HDONE_ERROR(H5E_FILE, H5E_CANTRELEASE, FAIL, "can't release file free space info")
 
@@ -913,7 +947,7 @@ H5F_dest(H5F_t *f, hid_t dxpl_id, hbool_t flush)
                     f->shared->sblock->status_flags &= (uint8_t)(~H5F_SUPER_SWMR_WRITE_ACCESS);
 
                     /* Mark EOA info dirty in cache, so change will get encoded */
-                    if(H5F_eoa_dirty(f, dxpl_id) < 0)
+                    if(H5F_eoa_dirty(f, meta_dxpl_id) < 0)
                         /* Push error, but keep going*/
                         HDONE_ERROR(H5E_FILE, H5E_CANTMARKDIRTY, FAIL, "unable to mark superblock as dirty")
 
@@ -924,12 +958,12 @@ H5F_dest(H5F_t *f, hid_t dxpl_id, hbool_t flush)
                      * At most, this should change the superblock or the
                      * superblock extension messages.
                      */
-                    if(H5MF_free_aggrs(f, dxpl_id) < 0)
+                    if(H5MF_free_aggrs(f, meta_dxpl_id) < 0)
                         /* Push error, but keep going*/
                         HDONE_ERROR(H5E_FILE, H5E_CANTRELEASE, FAIL, "can't release file space")
 
                     /* Truncate the file to the current allocated size */
-                    if(H5FD_truncate(f->shared->lf, dxpl_id, TRUE) < 0)
+                    if(H5FD_truncate(f->shared->lf, meta_dxpl_id, TRUE) < 0)
                         /* Push error, but keep going*/
                         HDONE_ERROR(H5E_FILE, H5E_WRITEERROR, FAIL, "low level truncate failed")
 
@@ -968,10 +1002,15 @@ H5F_dest(H5F_t *f, hid_t dxpl_id, hbool_t flush)
             HDONE_ERROR(H5E_FILE, H5E_CANTRELEASE, FAIL, "problems closing file")
 
         /* Shutdown the metadata cache */
-        if(H5AC_dest(f, dxpl_id))
+        if(H5AC_dest(f, meta_dxpl_id))
             /* Push error, but keep going*/
             HDONE_ERROR(H5E_FILE, H5E_CANTRELEASE, FAIL, "problems closing file")
 
+        /* Shutdown the page buffer cache */
+        if(H5PB_dest(f) < 0)
+            /* Push error, but keep going*/
+            HDONE_ERROR(H5E_FILE, H5E_CANTRELEASE, FAIL, "problems closing page buffer cache")
+
         /* Clean up the metadata cache log location string */
         if(f->shared->mdc_log_location)
             f->shared->mdc_log_location = (char *)H5MM_xfree(f->shared->mdc_log_location);
@@ -990,7 +1029,9 @@ H5F_dest(H5F_t *f, hid_t dxpl_id, hbool_t flush)
 
         /* Set up I/O info for operation */
         fio_info.f = f;
-        if(NULL == (fio_info.dxpl = (H5P_genplist_t *)H5I_object(dxpl_id)))
+        if(NULL == (fio_info.meta_dxpl = (H5P_genplist_t *)H5I_object(meta_dxpl_id)))
+            HDONE_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+        if(NULL == (fio_info.raw_dxpl = (H5P_genplist_t *)H5I_object(H5AC_rawdata_dxpl_id)))
             HDONE_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
 
         /* Destroy other components of the file */
@@ -1130,7 +1171,7 @@ H5F_dest(H5F_t *f, hid_t dxpl_id, hbool_t flush)
  */
 H5F_t *
 H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id,
-    hid_t dxpl_id)
+    hid_t meta_dxpl_id)
 {
     H5F_t              *file = NULL;        /*the success return value      */
     H5F_file_t         *shared = NULL;      /*shared part of `file'         */
@@ -1139,6 +1180,10 @@ H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id,
     H5FD_class_t       *drvr;               /*file driver class info        */
     H5P_genplist_t     *a_plist;            /*file access property list     */
     H5F_close_degree_t  fc_degree;          /*file close degree             */
+    hid_t               raw_dxpl_id = H5AC_rawdata_dxpl_id;    /* Raw data dxpl used by library        */
+    size_t              page_buf_size;
+    unsigned            page_buf_min_meta_perc;
+    unsigned            page_buf_min_raw_perc;
     hbool_t             set_flag = FALSE;   /*set the status_flags in the superblock */
     hbool_t             clear = FALSE;      /*clear the status_flags 	    */
     hbool_t             evict_on_close;     /* evict on close value from plist  */
@@ -1289,6 +1334,25 @@ H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id,
     if(NULL == (a_plist = (H5P_genplist_t *)H5I_object(fapl_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "not file access property list")
 
+    /* Check if page buffering is enabled */
+    if(H5P_get(a_plist, H5F_ACS_PAGE_BUFFER_SIZE_NAME, &page_buf_size) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTGET, NULL, "can't get page buffer size")
+    if(page_buf_size) {
+#ifdef H5_HAVE_PARALLEL
+        /* Collective metadata writes are not supported with page buffering */
+        if(file->coll_md_write)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "collective metadata writes are not supported with page buffering")
+
+        /* Temporary: fail file create when page buffering feature is enabled for parallel */
+        HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "page buffering is disabled for parallel")
+#endif /* H5_HAVE_PARALLEL */
+        /* Query for other page buffer cache properties */
+        if(H5P_get(a_plist, H5F_ACS_PAGE_BUFFER_MIN_META_PERC_NAME, &page_buf_min_meta_perc) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTGET, NULL, "can't get minimum metadata fraction of page buffer")
+        if(H5P_get(a_plist, H5F_ACS_PAGE_BUFFER_MIN_RAW_PERC_NAME, &page_buf_min_raw_perc) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTGET, NULL, "can't get minimum raw data fraction of page buffer")
+    } /* end if */
+
     /*
      * Read or write the file superblock, depending on whether the file is
      * empty or not.
@@ -1299,26 +1363,35 @@ H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id,
          * to create & write the superblock.
          */
 
+        /* Create the page buffer before initializing the superblock */
+        if(page_buf_size)
+            if(H5PB_create(file, page_buf_size, page_buf_min_meta_perc, page_buf_min_raw_perc) < 0)
+                HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, NULL, "unable to create page buffer")
+
         /* Initialize information about the superblock and allocate space for it */
         /* (Writes superblock extension messages, if there are any) */
-        if(H5F__super_init(file, dxpl_id) < 0)
+        if(H5F__super_init(file, meta_dxpl_id) < 0)
             HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, NULL, "unable to allocate file superblock")
 
         /* Create and open the root group */
         /* (This must be after the space for the superblock is allocated in
          *      the file, since the superblock must be at offset 0)
          */
-        if(H5G_mkroot(file, dxpl_id, TRUE) < 0)
+        if(H5G_mkroot(file, meta_dxpl_id, TRUE) < 0)
             HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, NULL, "unable to create/open root group")
     } /* end if */
     else if (1 == shared->nrefs) {
-
         /* Read the superblock if it hasn't been read before. */
-        if(H5F__super_read(file, dxpl_id, TRUE) < 0)
+        if(H5F__super_read(file, meta_dxpl_id, raw_dxpl_id, TRUE) < 0)
             HGOTO_ERROR(H5E_FILE, H5E_READERROR, NULL, "unable to read superblock")
 
+        /* Create the page buffer before initializing the superblock */
+        if(page_buf_size)
+            if(H5PB_create(file, page_buf_size, page_buf_min_meta_perc, page_buf_min_raw_perc) < 0)
+                HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, NULL, "unable to create page buffer")
+
         /* Open the root group */
-        if(H5G_mkroot(file, dxpl_id, FALSE) < 0)
+        if(H5G_mkroot(file, meta_dxpl_id, FALSE) < 0)
             HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to read root group")
     } /* end if */
 
@@ -1360,12 +1433,11 @@ H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id,
      */
     if(H5P_get(a_plist, H5F_ACS_EVICT_ON_CLOSE_FLAG_NAME, &evict_on_close) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get evict on close value")
-
-    if(shared->nrefs == 1) {
+    if(shared->nrefs == 1)
         shared->evict_on_close = evict_on_close;
-    } else if(shared->nrefs > 1) {
+    else if(shared->nrefs > 1) {
         if(shared->evict_on_close != evict_on_close)
-            HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, NULL, "file evict-on-close value doesn't match")
+            HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, NULL, "file evict-on-close value doesn't match")
     } /* end if */
 
     /* Formulate the absolute path for later search of target file for external links */
@@ -1393,7 +1465,7 @@ H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id,
             /* Flush the superblock */
             if(H5F_super_dirty(file) < 0)
                 HGOTO_ERROR(H5E_FILE, H5E_CANTMARKDIRTY, NULL, "unable to mark superblock as dirty")
-            if(H5F_flush_tagged_metadata(file, H5AC__SUPERBLOCK_TAG, H5AC_ind_read_dxpl_id) < 0)
+            if(H5F_flush_tagged_metadata(file, H5AC__SUPERBLOCK_TAG, meta_dxpl_id) < 0)
                 HGOTO_ERROR(H5E_FILE, H5E_CANTFLUSH, NULL, "unable to flush superblock")
 
             /* Remove the file lock for SWMR_WRITE */
@@ -1405,7 +1477,6 @@ H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id,
         else { /* H5F_ACC_RDONLY: check consistency of status_flags */
             /* Skip check of status_flags for file with < superblock version 3 */
             if(file->shared->sblock->super_vers >= HDF5_SUPERBLOCK_VERSION_3) {
-
                 if(H5F_INTENT(file) & H5F_ACC_SWMR_READ) { 
                     if((file->shared->sblock->status_flags & H5F_SUPER_WRITE_ACCESS && 
                             !(file->shared->sblock->status_flags & H5F_SUPER_SWMR_WRITE_ACCESS))
@@ -1413,12 +1484,10 @@ H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id,
                             (!(file->shared->sblock->status_flags & H5F_SUPER_WRITE_ACCESS) && 
                             file->shared->sblock->status_flags & H5F_SUPER_SWMR_WRITE_ACCESS))
                         HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "file is not already open for SWMR writing")
-
                 } /* end if */
                 else if((file->shared->sblock->status_flags & H5F_SUPER_WRITE_ACCESS) ||
                         (file->shared->sblock->status_flags & H5F_SUPER_SWMR_WRITE_ACCESS))
                     HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "file is already open for write (may use <h5clear file> to clear file consistency flags)")
-
             } /* version 3 superblock */
         } /* end else */
     } /* end if set_flag */
@@ -1428,7 +1497,7 @@ H5F_open(const char *name, unsigned flags, hid_t fcpl_id, hid_t fapl_id,
 
 done:
     if((NULL == ret_value) && file)
-        if(H5F_dest(file, dxpl_id, FALSE) < 0)
+        if(H5F__dest(file, meta_dxpl_id, raw_dxpl_id, FALSE) < 0)
             HDONE_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, NULL, "problems closing file")
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5F_open() */
@@ -1448,7 +1517,7 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F__flush_phase1(H5F_t *f, hid_t dxpl_id)
+H5F__flush_phase1(H5F_t *f, hid_t meta_dxpl_id)
 {
     herr_t   ret_value = SUCCEED;       /* Return value */
 
@@ -1458,7 +1527,7 @@ H5F__flush_phase1(H5F_t *f, hid_t dxpl_id)
     HDassert(f);
 
     /* Flush any cached dataset storage raw data */
-    if(H5D_flush(f, dxpl_id) < 0)
+    if(H5D_flush(f, meta_dxpl_id) < 0)
         /* Push error, but keep going*/
         HDONE_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "unable to flush dataset cache")
 
@@ -1468,7 +1537,7 @@ H5F__flush_phase1(H5F_t *f, hid_t dxpl_id)
     /* (needs to happen before cache flush, with superblock write, since the
      *  'eoa' value is written in superblock -QAK)
      */
-    if(H5MF_free_aggrs(f, dxpl_id) < 0)
+    if(H5MF_free_aggrs(f, meta_dxpl_id) < 0)
         /* Push error, but keep going*/
         HDONE_ERROR(H5E_FILE, H5E_CANTRELEASE, FAIL, "can't release file space")
 
@@ -1490,9 +1559,9 @@ H5F__flush_phase1(H5F_t *f, hid_t dxpl_id)
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F__flush_phase2(H5F_t *f, hid_t dxpl_id, hbool_t closing)
+H5F__flush_phase2(H5F_t *f, hid_t meta_dxpl_id, hid_t raw_dxpl_id, hbool_t closing)
 {
-    H5F_io_info_t fio_info;             /* I/O info for operation */
+    H5F_io_info2_t fio_info;            /* I/O info for operation */
     herr_t   ret_value = SUCCEED;       /* Return value */
 
     FUNC_ENTER_STATIC
@@ -1501,23 +1570,26 @@ H5F__flush_phase2(H5F_t *f, hid_t dxpl_id, hbool_t closing)
     HDassert(f);
 
     /* Flush the entire metadata cache */
-    if(H5AC_flush(f, dxpl_id) < 0)
+    if(H5AC_flush(f, meta_dxpl_id) < 0)
         /* Push error, but keep going*/
         HDONE_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "unable to flush metadata cache")
 
     /* Truncate the file to the current allocated size */
-    if(H5FD_truncate(f->shared->lf, dxpl_id, closing) < 0)
+    if(H5FD_truncate(f->shared->lf, meta_dxpl_id, closing) < 0)
         /* Push error, but keep going*/
         HDONE_ERROR(H5E_FILE, H5E_WRITEERROR, FAIL, "low level truncate failed")
 
     /* Flush the entire metadata cache again since the EOA could have changed in the truncate call. */
-    if(H5AC_flush(f, dxpl_id) < 0)
+    if(H5AC_flush(f, meta_dxpl_id) < 0)
         /* Push error, but keep going*/
         HDONE_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "unable to flush metadata cache")
 
     /* Set up I/O info for operation */
     fio_info.f = f;
-    if(NULL == (fio_info.dxpl = (H5P_genplist_t *)H5I_object(dxpl_id)))
+    if(NULL == (fio_info.meta_dxpl = (H5P_genplist_t *)H5I_object(meta_dxpl_id)))
+        /* Push error, but keep going*/
+        HDONE_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+    if(NULL == (fio_info.raw_dxpl = (H5P_genplist_t *)H5I_object(raw_dxpl_id)))
         /* Push error, but keep going*/
         HDONE_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
 
@@ -1526,8 +1598,13 @@ H5F__flush_phase2(H5F_t *f, hid_t dxpl_id, hbool_t closing)
         /* Push error, but keep going*/
         HDONE_ERROR(H5E_IO, H5E_CANTFLUSH, FAIL, "unable to flush metadata accumulator")
 
+    /* Flush the page buffer */
+    if(H5PB_flush(&fio_info) < 0)
+        /* Push error, but keep going*/
+        HDONE_ERROR(H5E_IO, H5E_CANTFLUSH, FAIL, "page buffer flush failed")
+
     /* Flush file buffers to disk. */
-    if(H5FD_flush(f->shared->lf, dxpl_id, closing) < 0)
+    if(H5FD_flush(f->shared->lf, meta_dxpl_id, closing) < 0)
         /* Push error, but keep going*/
         HDONE_ERROR(H5E_IO, H5E_CANTFLUSH, FAIL, "low level flush failed")
 
@@ -1536,7 +1613,7 @@ H5F__flush_phase2(H5F_t *f, hid_t dxpl_id, hbool_t closing)
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5F_flush
+ * Function:	H5F__flush
  *
  * Purpose:	Flushes cached data.
  *
@@ -1549,28 +1626,27 @@ H5F__flush_phase2(H5F_t *f, hid_t dxpl_id, hbool_t closing)
  *-------------------------------------------------------------------------
  */
 herr_t
-H5F_flush(H5F_t *f, hid_t dxpl_id, hbool_t closing)
+H5F__flush(H5F_t *f, hid_t meta_dxpl_id, hid_t raw_dxpl_id, hbool_t closing)
 {
     herr_t   ret_value = SUCCEED;       /* Return value */
 
-    FUNC_ENTER_NOAPI(FAIL)
+    FUNC_ENTER_PACKAGE
 
     /* Sanity check arguments */
     HDassert(f);
 
     /* First phase of flushing data */
-    if(H5F__flush_phase1(f, dxpl_id) < 0)
+    if(H5F__flush_phase1(f, meta_dxpl_id) < 0)
         /* Push error, but keep going*/
         HDONE_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "unable to flush file data")
 
     /* Second phase of flushing data */
-    if(H5F__flush_phase2(f, dxpl_id, closing) < 0)
+    if(H5F__flush_phase2(f, meta_dxpl_id, raw_dxpl_id, closing) < 0)
         /* Push error, but keep going*/
         HDONE_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "unable to flush file data")
 
-done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5F_flush() */
+} /* end H5F__flush() */
 
 
 /*-------------------------------------------------------------------------
@@ -1795,7 +1871,7 @@ H5F_try_close(H5F_t *f, hbool_t *was_closed /*out*/)
         if(H5F_efc_try_close(f) < 0)
             HGOTO_ERROR(H5E_FILE, H5E_CANTRELEASE, FAIL, "can't attempt to close EFC")
 
-    /* Delay flush until the shared file struct is closed, in H5F_dest.  If the
+    /* Delay flush until the shared file struct is closed, in H5F__dest.  If the
      * application called H5Fclose, it would have been flushed in that function
      * (unless it will have been flushed in H5F_dest anyways). */
 
@@ -1804,7 +1880,7 @@ H5F_try_close(H5F_t *f, hbool_t *was_closed /*out*/)
      * shared H5F_file_t struct. If the reference count for the H5F_file_t
      * struct reaches zero then destroy it also.
      */
-    if(H5F_dest(f, H5AC_ind_read_dxpl_id, TRUE) < 0)
+    if(H5F__dest(f, H5AC_ind_read_dxpl_id, H5AC_rawdata_dxpl_id, TRUE) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL, "problems closing file")
 
     /* Since we closed the file, this should be set to TRUE */
@@ -2362,7 +2438,8 @@ H5F_set_store_msg_crt_idx(H5F_t *f, hbool_t flag)
  *-------------------------------------------------------------------------
  */
 ssize_t
-H5F_get_file_image(H5F_t *file, void *buf_ptr, size_t buf_len, hid_t dxpl_id)
+H5F_get_file_image(H5F_t *file, void *buf_ptr, size_t buf_len, hid_t meta_dxpl_id,
+    hid_t raw_dxpl_id)
 {
     H5FD_t     *fd_ptr;                 /* file driver */
     haddr_t     eoa;                    /* End of file address */
@@ -2429,10 +2506,10 @@ H5F_get_file_image(H5F_t *file, void *buf_ptr, size_t buf_len, hid_t dxpl_id)
 
     /* test to see if a buffer was provided -- if not, we are done */
     if(buf_ptr != NULL) {
+        H5FD_io_info_t fdio_info;       /* File driver I/O info */
         size_t	space_needed;		/* size of file image */
         hsize_t tmp;
         size_t tmp_size;
-        H5P_genplist_t *xfer_plist= NULL;  /* Dataset transfer property list object */
 
         /* Check for buffer too small */
         if((haddr_t)buf_len < eoa)
@@ -2440,13 +2517,16 @@ H5F_get_file_image(H5F_t *file, void *buf_ptr, size_t buf_len, hid_t dxpl_id)
 
         space_needed = (size_t)eoa;
 
-        /* Get the property list object */
-        if(NULL == (xfer_plist = (H5P_genplist_t *)H5I_object(dxpl_id)))
-            HGOTO_ERROR(H5E_CACHE, H5E_BADATOM, FAIL, "can't get new property list object")
+        /* Set up file driver I/O info object */
+        fdio_info.file = fd_ptr;
+        if(NULL == (fdio_info.meta_dxpl = (H5P_genplist_t *)H5I_object(meta_dxpl_id)))
+            HGOTO_ERROR(H5E_CACHE, H5E_BADATOM, FAIL, "can't get property list object")
+        if(NULL == (fdio_info.raw_dxpl = (H5P_genplist_t *)H5I_object(raw_dxpl_id)))
+            HGOTO_ERROR(H5E_CACHE, H5E_BADATOM, FAIL, "can't get property list object")
 
         /* read in the file image */
         /* (Note compensation for base address addition in internal routine) */
-        if(H5FD_read(fd_ptr, xfer_plist, H5FD_MEM_DEFAULT, 0, space_needed, buf_ptr) < 0)
+        if(H5FD_read(&fdio_info, H5FD_MEM_DEFAULT, 0, space_needed, buf_ptr) < 0)
             HGOTO_ERROR(H5E_FILE, H5E_READERROR, FAIL, "file image read request failed")
 
         /* Offset to "status_flags" in the superblock */
@@ -2648,6 +2728,38 @@ done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5F__set_eoa() */
 
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F__set_paged_aggr
+ *
+ * Purpose:	Quick and dirty routine to set the file's paged_aggr mode
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Quincey Koziol <koziol@hdfgroup.org>
+ *		June 19, 2015
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5F__set_paged_aggr(const H5F_t *f, hbool_t paged)
+{
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_PACKAGE
+
+    /* Sanity check */
+    HDassert(f);
+    HDassert(f->shared);
+
+    /* Dispatch to driver */
+    if(H5FD_set_paged_aggr(f->shared->lf, paged) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "driver set paged aggr mode failed")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5F__set_paged_aggr() */
+
 #ifdef H5_HAVE_PARALLEL
 
 /*-------------------------------------------------------------------------
diff --git a/src/H5Fio.c b/src/H5Fio.c
index afe1278..6d23995 100644
--- a/src/H5Fio.c
+++ b/src/H5Fio.c
@@ -39,6 +39,7 @@
 #include "H5Fpkg.h"             /* File access				*/
 #include "H5FDprivate.h"	/* File drivers				*/
 #include "H5Iprivate.h"		/* IDs			  		*/
+#include "H5PBprivate.h"	/* Page Buffer				*/
 
 
 /****************/
@@ -96,15 +97,11 @@ herr_t
 H5F_block_read(const H5F_t *f, H5FD_mem_t type, haddr_t addr, size_t size,
     hid_t dxpl_id, void *buf/*out*/)
 {
-    H5F_io_info_t fio_info;             /* I/O info for operation */
+    H5F_io_info2_t fio_info;            /* I/O info for operation */
     H5FD_mem_t  map_type;               /* Mapped memory type */
-    hid_t       my_dxpl_id = dxpl_id;   /* transfer property to use for I/O */
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
-#ifdef QAK
-HDfprintf(stderr, "%s: read from addr = %a, size = %Zu\n", FUNC, addr, size);
-#endif /* QAK */
 
     HDassert(f);
     HDassert(f->shared);
@@ -118,20 +115,24 @@ HDfprintf(stderr, "%s: read from addr = %a, size = %Zu\n", FUNC, addr, size);
     /* Treat global heap as raw data */
     map_type = (type == H5FD_MEM_GHEAP) ? H5FD_MEM_DRAW : type;
 
-#ifdef H5_DEBUG_BUILD
-    /* GHEAP type is treated as RAW, so update the dxpl type property too */
-    if(H5FD_MEM_GHEAP == type)
-        my_dxpl_id = H5AC_rawdata_dxpl_id;
-#endif /* H5_DEBUG_BUILD */
-
-    /* Set up I/O info for operation */
+    /* Set up the I/O info object */
     fio_info.f = f;
-    if(NULL == (fio_info.dxpl = (H5P_genplist_t *)H5I_object(my_dxpl_id)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+    if(H5FD_MEM_DRAW == type) {
+        if(NULL == (fio_info.meta_dxpl = (H5P_genplist_t *)H5I_object(H5AC_ind_read_dxpl_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+        if(NULL == (fio_info.raw_dxpl = (H5P_genplist_t *)H5I_object(dxpl_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+    } /* end if */
+    else {
+        if(NULL == (fio_info.meta_dxpl = (H5P_genplist_t *)H5I_object(dxpl_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+        if(NULL == (fio_info.raw_dxpl = (H5P_genplist_t *)H5I_object(H5AC_rawdata_dxpl_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+    } /* end else */
 
-    /* Pass through metadata accumulator layer */
-    if(H5F__accum_read(&fio_info, map_type, addr, size, buf) < 0)
-        HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL, "read through metadata accumulator failed")
+    /* Pass through page buffer layer */
+    if(H5PB_read(&fio_info, map_type, addr, size, buf) < 0)
+        HGOTO_ERROR(H5E_IO, H5E_READERROR, FAIL, "read through page buffer failed")
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -157,15 +158,11 @@ herr_t
 H5F_block_write(const H5F_t *f, H5FD_mem_t type, haddr_t addr, size_t size,
     hid_t dxpl_id, const void *buf)
 {
-    H5F_io_info_t fio_info;             /* I/O info for operation */
+    H5F_io_info2_t fio_info;            /* I/O info for operation */
     H5FD_mem_t  map_type;               /* Mapped memory type */
-    hid_t       my_dxpl_id = dxpl_id;   /* transfer property to use for I/O */
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_NOAPI(FAIL)
-#ifdef QAK
-HDfprintf(stderr, "%s: write to addr = %a, size = %Zu\n", FUNC, addr, size);
-#endif /* QAK */
 
     HDassert(f);
     HDassert(f->shared);
@@ -180,20 +177,24 @@ HDfprintf(stderr, "%s: write to addr = %a, size = %Zu\n", FUNC, addr, size);
     /* Treat global heap as raw data */
     map_type = (type == H5FD_MEM_GHEAP) ? H5FD_MEM_DRAW : type;
 
-#ifdef H5_DEBUG_BUILD
-    /* GHEAP type is treated as RAW, so update the dxpl type property too */
-    if(H5FD_MEM_GHEAP == type)
-        my_dxpl_id = H5AC_rawdata_dxpl_id;
-#endif /* H5_DEBUG_BUILD */
-
-    /* Set up I/O info for operation */
+    /* Set up the I/O info object */
     fio_info.f = f;
-    if(NULL == (fio_info.dxpl = (H5P_genplist_t *)H5I_object(my_dxpl_id)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+    if(H5FD_MEM_DRAW == type) {
+        if(NULL == (fio_info.meta_dxpl = (H5P_genplist_t *)H5I_object(H5AC_ind_read_dxpl_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+        if(NULL == (fio_info.raw_dxpl = (H5P_genplist_t *)H5I_object(dxpl_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+    } /* end if */
+    else {
+        if(NULL == (fio_info.meta_dxpl = (H5P_genplist_t *)H5I_object(dxpl_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+        if(NULL == (fio_info.raw_dxpl = (H5P_genplist_t *)H5I_object(H5AC_rawdata_dxpl_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+    } /* end else */
 
-    /* Pass through metadata accumulator layer */
-    if(H5F__accum_write(&fio_info, map_type, addr, size, buf) < 0)
-        HGOTO_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "write through metadata accumulator failed")
+    /* Pass through page buffer layer */
+    if(H5PB_write(&fio_info, map_type, addr, size, buf) < 0)
+        HGOTO_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "write through page buffer failed")
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
@@ -216,7 +217,7 @@ done:
 herr_t
 H5F_flush_tagged_metadata(H5F_t * f, haddr_t tag, hid_t dxpl_id)
 {
-    H5F_io_info_t fio_info;             /* I/O info for operation */
+    H5F_io_info2_t fio_info;             /* I/O info for operation */
     herr_t ret_value = SUCCEED;
 
     FUNC_ENTER_NOAPI(FAIL)
@@ -227,10 +228,10 @@ H5F_flush_tagged_metadata(H5F_t * f, haddr_t tag, hid_t dxpl_id)
 
     /* Set up I/O info for operation */
     fio_info.f = f;
-
-    if(NULL == (fio_info.dxpl = (H5P_genplist_t *)H5I_object(dxpl_id)))
+    if(NULL == (fio_info.meta_dxpl = (H5P_genplist_t *)H5I_object(dxpl_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+    if(NULL == (fio_info.raw_dxpl = (H5P_genplist_t *)H5I_object(H5AC_rawdata_dxpl_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
-    
 
     /* Flush and reset the accumulator */
     if(H5F__accum_reset(&fio_info, TRUE) < 0)
diff --git a/src/H5Fmount.c b/src/H5Fmount.c
index e3d4952..859b9d6 100644
--- a/src/H5Fmount.c
+++ b/src/H5Fmount.c
@@ -614,7 +614,7 @@ H5F_mount_count_ids(H5F_t *f, unsigned *nopen_files, unsigned *nopen_objs)
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F_flush_mounts_recurse(H5F_t *f, hid_t dxpl_id)
+H5F_flush_mounts_recurse(H5F_t *f, hid_t meta_dxpl_id, hid_t raw_dxpl_id)
 {
     unsigned	nerrors = 0;            /* Errors from recursive flushes */
     unsigned    u;                      /* Index variable */
@@ -627,11 +627,11 @@ H5F_flush_mounts_recurse(H5F_t *f, hid_t dxpl_id)
 
     /* Flush all child files, not stopping for errors */
     for(u = 0; u < f->shared->mtab.nmounts; u++)
-        if(H5F_flush_mounts_recurse(f->shared->mtab.child[u].file, dxpl_id) < 0)
+        if(H5F_flush_mounts_recurse(f->shared->mtab.child[u].file, meta_dxpl_id, raw_dxpl_id) < 0)
             nerrors++;
 
     /* Call the "real" flush routine, for this file */
-    if(H5F_flush(f, dxpl_id, FALSE) < 0)
+    if(H5F__flush(f, meta_dxpl_id, raw_dxpl_id, FALSE) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to flush file's cached information")
 
     /* Check flush errors for children - errors are already on the stack */
@@ -656,7 +656,7 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5F_flush_mounts(H5F_t *f, hid_t dxpl_id)
+H5F_flush_mounts(H5F_t *f, hid_t meta_dxpl_id, hid_t raw_dxpl_id)
 {
     herr_t      ret_value = SUCCEED;       /* Return value */
 
@@ -670,7 +670,7 @@ H5F_flush_mounts(H5F_t *f, hid_t dxpl_id)
         f = f->parent;
 
     /* Flush the mounted file hierarchy */
-    if(H5F_flush_mounts_recurse(f, dxpl_id) < 0)
+    if(H5F_flush_mounts_recurse(f, meta_dxpl_id, raw_dxpl_id) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_CANTFLUSH, FAIL, "unable to flush mounted file hierarchy")
 
 done:
diff --git a/src/H5Fpkg.h b/src/H5Fpkg.h
index 93a3978..4dd9e20 100644
--- a/src/H5Fpkg.h
+++ b/src/H5Fpkg.h
@@ -42,6 +42,7 @@
 #include "H5FSprivate.h"	/* File free space                      */
 #include "H5Gprivate.h"		/* Groups 			  	*/
 #include "H5Oprivate.h"         /* Object header messages               */
+#include "H5PBprivate.h"        /* Page buffer                          */
 #include "H5UCprivate.h"	/* Reference counted object functions	*/
 
 
@@ -68,8 +69,8 @@
 
 /* Macro to abstract checking whether file is using a free space manager */
 #define H5F_HAVE_FREE_SPACE_MANAGER(F)  \
-    ((F)->shared->fs_strategy == H5F_FILE_SPACE_ALL ||                        \
-            (F)->shared->fs_strategy == H5F_FILE_SPACE_ALL_PERSIST)
+    ((F)->shared->fs_strategy == H5F_FSPACE_STRATEGY_FSM_AGGR ||                        \
+     (F)->shared->fs_strategy == H5F_FSPACE_STRATEGY_PAGE)
 
 /* Macros for encoding/decoding superblock */
 #define H5F_MAX_DRVINFOBLOCK_SIZE  1024         /* Maximum size of superblock driver info buffer */
@@ -200,13 +201,6 @@ typedef struct H5F_meta_accum_t {
     hbool_t             dirty;          /* Flag to indicate that the accumulated metadata is dirty */
 } H5F_meta_accum_t;
 
-/* Enum for free space manager state */
-typedef enum H5F_fs_state_t {
-    H5F_FS_STATE_CLOSED,                /* Free space manager is closed */
-    H5F_FS_STATE_OPEN,                  /* Free space manager has been opened */
-    H5F_FS_STATE_DELETING               /* Free space manager is being deleted */
-} H5F_fs_state_t;
-
 /* A record of the mount table */
 typedef struct H5F_mount_t {
     struct H5G_t	*group;	/* Mount point group held open		*/
@@ -281,6 +275,7 @@ struct H5F_file_t {
     unsigned long feature_flags; /* VFL Driver feature Flags            */
     haddr_t	maxaddr;	/* Maximum address for file             */
 
+    H5PB_t      *page_buf;                  /* The page buffer cache                */
     H5AC_t      *cache;		/* The object cache	 		*/
     H5AC_cache_config_t
 		mdc_initCacheCfg; /* initial configuration for the      */
@@ -316,19 +311,38 @@ struct H5F_file_t {
     H5UC_t *grp_btree_shared;   /* Ref-counted group B-tree node info   */
 
     /* File space allocation information */
-    H5F_file_space_type_t fs_strategy;	/* File space handling strategy		*/
+    H5F_fspace_strategy_t fs_strategy;      /* File space handling strategy	*/
     hsize_t     fs_threshold;	/* Free space section threshold 	*/
+    hbool_t fs_persist;                     /* Free-space persist or not */
     hbool_t     use_tmp_space;  /* Whether temp. file space allocation is allowed */
     haddr_t	tmp_addr;       /* Next address to use for temp. space in the file */
+    hbool_t point_of_no_return;             /* flag to indicate that we can't go back and delete a freespace header when it's used up */
+
+    H5F_fs_state_t fs_state[H5F_MEM_PAGE_NTYPES];   /* State of free space manager for each type */
+    haddr_t fs_addr[H5F_MEM_PAGE_NTYPES];           /* Address of free space manager info for each type */
+    H5FS_t *fs_man[H5F_MEM_PAGE_NTYPES];            /* Free space manager for each file space type */
+    hbool_t first_alloc_dealloc;            /* TRUE iff free space managers   */
+                                            /* are persistant and have not    */
+                                            /* been used accessed for either  */
+                                            /* allocation or deallocation     */
+                                            /* since file open.               */
+    haddr_t eoa_pre_fsm_fsalloc;	    /* eoa pre file space allocation  */
+                                            /* for self referential FSMs      */
+    haddr_t eoa_post_fsm_fsalloc;           /* eoa post file space allocation */
+                                            /* for self referential FSMs      */
+    haddr_t eoa_post_mdci_fsalloc;          /* eoa past file space allocation */
+                                            /* for metadata cache image, or   */
+                                            /* HADDR_UNDEF if no cache image. */
+
+    /* Free-space aggregation info */
     unsigned fs_aggr_merge[H5FD_MEM_NTYPES];    /* Flags for whether free space can merge with aggregator(s) */
-    H5F_fs_state_t fs_state[H5FD_MEM_NTYPES];   /* State of free space manager for each type */
-    haddr_t fs_addr[H5FD_MEM_NTYPES];   /* Address of free space manager info for each type */
-    H5FS_t *fs_man[H5FD_MEM_NTYPES];    /* Free space manager for each file space type */
-    H5FD_mem_t fs_type_map[H5FD_MEM_NTYPES]; /* Mapping of "real" file space type into tracked type */
-    H5F_blk_aggr_t meta_aggr;   /* Metadata aggregation info */
-                                /* (if aggregating metadata allocations) */
-    H5F_blk_aggr_t sdata_aggr;  /* "Small data" aggregation info */
-                                /* (if aggregating "small data" allocations) */
+    H5FD_mem_t fs_type_map[H5FD_MEM_NTYPES];    /* Mapping of "real" file space type into tracked type */
+    H5F_blk_aggr_t meta_aggr;   	        /* Metadata aggregation info (if aggregating metadata allocations) */
+    H5F_blk_aggr_t sdata_aggr;                  /* "Small data" aggregation info (if aggregating "small data" allocations) */
+
+    /* Paged aggregation info */
+    hsize_t fs_page_size;                           /* File space page size */
+    size_t pgend_meta_thres;                        /* Do not track page end meta section <= this threshold */
 
     /* Metadata accumulator information */
     H5F_meta_accum_t accum;     /* Metadata accumulator info           	*/
@@ -383,11 +397,12 @@ H5FL_EXTERN(H5F_file_t);
 /* General routines */
 H5F_t *H5F_new(H5F_file_t *shared, unsigned flags, hid_t fcpl_id,
     hid_t fapl_id, H5FD_t *lf);
-herr_t H5F_dest(H5F_t *f, hid_t dxpl_id, hbool_t flush);
-H5_DLL herr_t H5F_flush(H5F_t *f, hid_t dxpl_id, hbool_t closing);
-H5_DLL htri_t H5F_is_hdf5(const char *name, hid_t dxpl_id);
+H5_DLL herr_t H5F__dest(H5F_t *f, hid_t meta_dxpl_id, hid_t raw_dxpl_id, hbool_t flush);
+H5_DLL herr_t H5F__flush(H5F_t *f, hid_t meta_dxpl_id, hid_t raw_dxpl_id, hbool_t closing);
+H5_DLL htri_t H5F__is_hdf5(const char *name, hid_t meta_dxpl_id, hid_t raw_dxpl_id);
 H5_DLL herr_t H5F_get_objects(const H5F_t *f, unsigned types, size_t max_index, hid_t *obj_id_list, hbool_t app_ref, size_t *obj_id_count_ptr);
-H5_DLL ssize_t H5F_get_file_image(H5F_t *f, void *buf_ptr, size_t buf_len, hid_t dxpl_id);
+H5_DLL ssize_t H5F_get_file_image(H5F_t *f, void *buf_ptr, size_t buf_len,
+    hid_t meta_dxpl_id, hid_t raw_dxpl_id);
 H5_DLL herr_t H5F_close(H5F_t *f);
 
 /* File mount related routines */
@@ -397,7 +412,8 @@ H5_DLL herr_t H5F_mount_count_ids(H5F_t *f, unsigned *nopen_files, unsigned *nop
 
 /* Superblock related routines */
 H5_DLL herr_t H5F__super_init(H5F_t *f, hid_t dxpl_id);
-H5_DLL herr_t H5F__super_read(H5F_t *f, hid_t dxpl_id, hbool_t initial_read);
+H5_DLL herr_t H5F__super_read(H5F_t *f, hid_t meta_dxpl_id, hid_t raw_dxpl_id,
+    hbool_t initial_read);
 H5_DLL herr_t H5F__super_size(H5F_t *f, hid_t dxpl_id, hsize_t *super_size, hsize_t *super_ext_size);
 H5_DLL herr_t H5F__super_free(H5F_super_t *sblock);
 
@@ -410,14 +426,14 @@ H5_DLL herr_t H5F_super_ext_close(H5F_t *f, H5O_loc_t *ext_ptr, hid_t dxpl_id,
     hbool_t was_created);
 
 /* Metadata accumulator routines */
-H5_DLL herr_t H5F__accum_read(const H5F_io_info_t *fio_info, H5FD_mem_t type,
+H5_DLL herr_t H5F__accum_read(const H5F_io_info2_t *fio_info, H5FD_mem_t type,
     haddr_t addr, size_t size, void *buf);
-H5_DLL herr_t H5F__accum_write(const H5F_io_info_t *fio_info, H5FD_mem_t type,
+H5_DLL herr_t H5F__accum_write(const H5F_io_info2_t *fio_info, H5FD_mem_t type,
     haddr_t addr, size_t size, const void *buf);
-H5_DLL herr_t H5F__accum_free(const H5F_io_info_t *fio_info, H5FD_mem_t type,
+H5_DLL herr_t H5F__accum_free(const H5F_io_info2_t *fio_info, H5FD_mem_t type,
     haddr_t addr, hsize_t size);
-H5_DLL herr_t H5F__accum_flush(const H5F_io_info_t *fio_info);
-H5_DLL herr_t H5F__accum_reset(const H5F_io_info_t *fio_info, hbool_t flush);
+H5_DLL herr_t H5F__accum_flush(const H5F_io_info2_t *fio_info);
+H5_DLL herr_t H5F__accum_reset(const H5F_io_info2_t *fio_info, hbool_t flush);
 
 /* Shared file list related routines */
 H5_DLL herr_t H5F_sfile_add(H5F_file_t *shared);
@@ -431,9 +447,16 @@ H5_DLL herr_t H5F_efc_release(H5F_efc_t *efc);
 H5_DLL herr_t H5F_efc_destroy(H5F_efc_t *efc);
 H5_DLL herr_t H5F_efc_try_close(H5F_t *f);
 
+/* Space allocation routines */
+H5_DLL haddr_t H5F_alloc(H5F_t *f, hid_t dxpl_id, H5F_mem_t type, hsize_t size, haddr_t *frag_addr, hsize_t *frag_size);
+H5_DLL herr_t H5F_free(H5F_t *f, hid_t dxpl_id, H5F_mem_t type, haddr_t addr, hsize_t size);
+H5_DLL htri_t H5F_try_extend(H5F_t *f, hid_t dxpl_id, H5FD_mem_t type, 
+    haddr_t blk_end, hsize_t extra_requested);
+
 /* Functions that get/retrieve values from VFD layer */
 H5_DLL herr_t H5F__set_eoa(const H5F_t *f, H5F_mem_t type, haddr_t addr);
 H5_DLL herr_t H5F__set_base_addr(const H5F_t *f, haddr_t addr);
+H5_DLL herr_t H5F__set_paged_aggr(const H5F_t *f, hbool_t paged);
 
 /* Functions that flush or evict */
 H5_DLL herr_t H5F__evict_cache_entries(H5F_t *f, hid_t dxpl_id);
diff --git a/src/H5Fprivate.h b/src/H5Fprivate.h
index 7d288fa..886063a 100644
--- a/src/H5Fprivate.h
+++ b/src/H5Fprivate.h
@@ -315,8 +315,8 @@
 #define H5F_SET_STORE_MSG_CRT_IDX(F, FL)    ((F)->shared->store_msg_crt_idx = (FL))
 #define H5F_GRP_BTREE_SHARED(F) ((F)->shared->grp_btree_shared)
 #define H5F_SET_GRP_BTREE_SHARED(F, RC) (((F)->shared->grp_btree_shared = (RC)) ? SUCCEED : FAIL)
-#define H5F_USE_TMP_SPACE(F)    ((F)->shared->use_tmp_space)
-#define H5F_IS_TMP_ADDR(F, ADDR) (H5F_addr_le((F)->shared->tmp_addr, (ADDR)))
+#define H5F_USE_TMP_SPACE(F)    ((F)->shared->fs.use_tmp_space)
+#define H5F_IS_TMP_ADDR(F, ADDR) (H5F_addr_le((F)->shared->fs.tmp_addr, (ADDR)))
 #define H5F_SET_LATEST_FLAGS(F, FL)  ((F)->shared->latest_flags = (FL))
 #ifdef H5_HAVE_PARALLEL
 #define H5F_COLL_MD_READ(F)     ((F)->coll_md_read)
@@ -324,6 +324,12 @@
 #define H5F_USE_MDC_LOGGING(F)  ((F)->shared->use_mdc_logging)
 #define H5F_START_MDC_LOG_ON_ACCESS(F)  ((F)->shared->start_mdc_log_on_access)
 #define H5F_MDC_LOG_LOCATION(F) ((F)->shared->mdc_log_location)
+#define H5F_ALIGNMENT(F)   	((F)->shared->alignment)
+#define H5F_THRESHOLD(F)   	((F)->shared->threshold)
+#define H5F_PGEND_META_THRES(F) ((F)->shared->fs.pgend_meta_thres)
+#define H5F_POINT_OF_NO_RETURN(F) ((F)->shared->fs.point_of_no_return)
+#define H5F_FIRST_ALLOC_DEALLOC(F) ((F)->shared->first_alloc_dealloc)
+#define H5F_EOA_PRE_FSM_FSALLOC(F) ((F)->shared->eoa_pre_fsm_fsalloc)
 #else /* H5F_MODULE */
 #define H5F_INTENT(F)           (H5F_get_intent(F))
 #define H5F_OPEN_NAME(F)        (H5F_get_open_name(F))
@@ -375,6 +381,12 @@
 #define H5F_USE_MDC_LOGGING(F)  (H5F_use_mdc_logging(F))
 #define H5F_START_MDC_LOG_ON_ACCESS(F)  (H5F_start_mdc_log_on_access(F))
 #define H5F_MDC_LOG_LOCATION(F) (H5F_mdc_log_location(F))
+#define H5F_ALIGNMENT(F)    	(H5F_get_alignment(F))
+#define H5F_THRESHOLD(F)    	(H5F_get_threshold(F))
+#define H5F_PGEND_META_THRES(F) (H5F_get_pgend_meta_thres(F))
+#define H5F_POINT_OF_NO_RETURN(F) (H5F_get_point_of_no_return(F))
+#define H5F_FIRST_ALLOC_DEALLOC(F) (H5F_get_first_alloc_dealloc(F))
+#define H5F_EOA_PRE_FSM_FSALLOC(F) (H5F_get_eoa_pre_fsm_fsalloc(F))
 #endif /* H5F_MODULE */
 
 
@@ -448,7 +460,9 @@
 #define H5F_CRT_SHMSG_LIST_MAX_NAME  "shmsg_list_max"   /* Shared message list maximum size */
 #define H5F_CRT_SHMSG_BTREE_MIN_NAME "shmsg_btree_min"  /* Shared message B-tree minimum size */
 #define H5F_CRT_FILE_SPACE_STRATEGY_NAME "file_space_strategy"  /* File space handling strategy */
+#define H5F_CRT_FREE_SPACE_PERSIST_NAME "free_space_persist"  	/* Free-space persisting status */
 #define H5F_CRT_FREE_SPACE_THRESHOLD_NAME "free_space_threshold"  /* Free space section threshold */
+#define H5F_CRT_FILE_SPACE_PAGE_SIZE_NAME "file_space_page_size"  /* File space page size */
 
 
 
@@ -484,6 +498,9 @@
 #define H5F_ACS_CORE_WRITE_TRACKING_PAGE_SIZE_NAME "core_write_tracking_page_size" /* The page size in kiB when core VFD write tracking is enabled */
 #define H5F_ACS_COLL_MD_WRITE_FLAG_NAME         "collective_metadata_write" /* property indicating whether metadata writes are done collectively or not */
 #define H5F_ACS_META_CACHE_INIT_IMAGE_CONFIG_NAME "mdc_initCacheImageCfg" /* Initial metadata cache image creation configuration */
+#define H5F_ACS_PAGE_BUFFER_SIZE_NAME           "page_buffer_size" /* the maximum size for the page buffer cache */
+#define H5F_ACS_PAGE_BUFFER_MIN_META_PERC_NAME  "page_buffer_min_meta_perc" /* the min metadata percentage for the page buffer cache */
+#define H5F_ACS_PAGE_BUFFER_MIN_RAW_PERC_NAME   "page_buffer_min_raw_perc" /* the min raw data percentage for the page buffer cache */
 
 /* ======================== File Mount properties ====================*/
 #define H5F_MNT_SYM_LOCAL_NAME 		"local"                 /* Whether absolute symlinks local to file. */
@@ -522,10 +539,34 @@
 						/* See format specification on version 1 B-trees */
 
 /* Default file space handling strategy */
-#define H5F_FILE_SPACE_STRATEGY_DEF	        H5F_FILE_SPACE_ALL
+#define H5F_FILE_SPACE_STRATEGY_DEF	        H5F_FSPACE_STRATEGY_FSM_AGGR
+
+/* Default free space section threshold used by free-space managers */
+#define H5F_FREE_SPACE_PERSIST_DEF	        FALSE
+
 /* Default free space section threshold used by free-space managers */
 #define H5F_FREE_SPACE_THRESHOLD_DEF	        1
 
+/* For paged aggregation: default file space page size when not set */
+#define H5F_FILE_SPACE_PAGE_SIZE_DEF     	4096    
+/* For paged aggregation: minimum value for file space page size */
+#define H5F_FILE_SPACE_PAGE_SIZE_MIN     	512
+
+/* For paged aggregation: drop free-space with size <= this threshold for small meta section */
+#define H5F_FILE_SPACE_PGEND_META_THRES  10    
+
+/* Default for threshold for alignment (can be set via H5Pset_alignment()) */
+#define H5F_ALIGN_DEF			1
+/* Default for alignment (can be set via H5Pset_alignment()) */
+#define H5F_ALIGN_THRHD_DEF		1
+/* Default size for meta data aggregation block (can be set via H5Pset_meta_block_size()) */
+#define H5F_META_BLOCK_SIZE_DEF		2048
+/* Default size for small data aggregation block (can be set via H5Pset_small_data_block_size()) */
+#define H5F_SDATA_BLOCK_SIZE_DEF	2048
+
+/* Check for file using paged aggregation */
+#define H5F_PAGED_AGGR(F) (F->shared->fs_strategy == H5F_FSPACE_STRATEGY_PAGE && F->shared->fs_page_size)
+
 /* Metadata read attempt values */
 #define H5F_METADATA_READ_ATTEMPTS		1	/* Default # of read attempts for non-SWMR access */
 #define H5F_SWMR_METADATA_READ_ATTEMPTS		100	/* Default # of read attempts for SWMR access */
@@ -628,18 +669,54 @@ typedef struct H5F_object_flush_t {
     void *udata;                /* User data */
 } H5F_object_flush_t;
 
-/* I/O Info for an operation */
+/* I/O Info for an operation (old) */
 typedef struct H5F_io_info_t {
     const H5F_t *f;                     /* File object */
     const struct H5P_genplist_t *dxpl;         /* DXPL object */
 } H5F_io_info_t;
 
+/* I/O Info for an operation */
+/* (Migrate toward this one, so that both raw data & metadata DXPLs are available) */
+typedef struct H5F_io_info2_t {
+    const H5F_t *f;                             /* File object */
+    const struct H5P_genplist_t *meta_dxpl;     /* Metadata DXPL object */
+    const struct H5P_genplist_t *raw_dxpl;      /* Raw data DXPL object */
+} H5F_io_info2_t;
+
 /* Concise info about a block of bytes in a file */
 typedef struct H5F_block_t {
     haddr_t offset;             /* Offset of the block in the file */
     hsize_t length;             /* Length of the block in the file */
 } H5F_block_t;
 
+/* Enum for free space manager state */
+typedef enum H5F_fs_state_t {
+    H5F_FS_STATE_CLOSED = 0,                /* Free space manager is closed */
+    H5F_FS_STATE_OPEN = 1,                  /* Free space manager has been opened */
+    H5F_FS_STATE_DELETING = 2               /* Free space manager is being deleted */
+} H5F_fs_state_t;
+
+/* For paged aggregation */
+/* The values 0 to 6 is the same as H5F_mem_t */
+typedef enum H5F_mem_page_t {
+    H5F_MEM_PAGE_DEFAULT = 0,       /* Not used */
+    H5F_MEM_PAGE_SUPER = 1,
+    H5F_MEM_PAGE_BTREE = 2,          
+    H5F_MEM_PAGE_DRAW = 3, 
+    H5F_MEM_PAGE_GHEAP = 4,      
+    H5F_MEM_PAGE_LHEAP = 5,      
+    H5F_MEM_PAGE_OHDR = 6,      
+    H5F_MEM_PAGE_LARGE_SUPER = 7,
+    H5F_MEM_PAGE_LARGE_BTREE = 8,
+    H5F_MEM_PAGE_LARGE_DRAW = 9,
+    H5F_MEM_PAGE_LARGE_GHEAP = 10,
+    H5F_MEM_PAGE_LARGE_LHEAP = 11,
+    H5F_MEM_PAGE_LARGE_OHDR = 12,
+    H5F_MEM_PAGE_NTYPES = 13       /* Sentinel value - must be last */
+} H5F_mem_page_t;
+
+#define H5F_MEM_PAGE_META       H5F_MEM_PAGE_SUPER          /* Small-sized meta data */
+#define H5F_MEM_PAGE_GENERIC    H5F_MEM_PAGE_LARGE_SUPER    /* Large-sized generic: meta and raw */
 
 /*****************************/
 /* Library-private Variables */
@@ -674,6 +751,10 @@ H5_DLL hid_t H5F_get_access_plist(H5F_t *f, hbool_t app_ref);
 H5_DLL hid_t H5F_get_id(H5F_t *file, hbool_t app_ref);
 H5_DLL herr_t H5F_get_obj_count(const H5F_t *f, unsigned types, hbool_t app_ref, size_t *obj_id_count_ptr);
 H5_DLL herr_t H5F_get_obj_ids(const H5F_t *f, unsigned types, size_t max_objs, hid_t *oid_list, hbool_t app_ref, size_t *obj_id_count_ptr);
+H5_DLL hsize_t H5F_get_pgend_meta_thres(const H5F_t *f);
+H5_DLL hbool_t H5F_get_point_of_no_return(const H5F_t *f);
+H5_DLL hbool_t H5F_get_first_alloc_dealloc(const H5F_t *f);
+H5_DLL hbool_t H5F_get_eoa_pre_fsm_fsalloc(const H5F_t *f);
 
 /* Functions than retrieve values set/cached from the superblock/FCPL */
 H5_DLL haddr_t H5F_get_base_addr(const H5F_t *f);
@@ -704,6 +785,8 @@ H5_DLL herr_t H5F_set_grp_btree_shared(H5F_t *f, struct H5UC_t *rc);
 H5_DLL hbool_t H5F_use_tmp_space(const H5F_t *f);
 H5_DLL hbool_t H5F_is_tmp_addr(const H5F_t *f, haddr_t addr);
 H5_DLL herr_t H5F_set_latest_flags(H5F_t *f, unsigned flags);
+H5_DLL hsize_t H5F_get_alignment(const H5F_t *f);
+H5_DLL hsize_t H5F_get_threshold(const H5F_t *f);
 #ifdef H5_HAVE_PARALLEL
 H5_DLL H5P_coll_md_read_flag_t H5F_coll_md_read(const H5F_t *f);
 H5_DLL void H5F_set_coll_md_read(H5F_t *f, H5P_coll_md_read_flag_t flag);
@@ -723,7 +806,7 @@ H5_DLL herr_t H5F_get_vfd_handle(const H5F_t *file, hid_t fapl, void **file_hand
 H5_DLL hbool_t H5F_is_mount(const H5F_t *file);
 H5_DLL hbool_t H5F_has_mount(const H5F_t *file);
 H5_DLL herr_t H5F_traverse_mount(struct H5O_loc_t *oloc/*in,out*/);
-H5_DLL herr_t H5F_flush_mounts(H5F_t *f, hid_t dxpl_id);
+H5_DLL herr_t H5F_flush_mounts(H5F_t *f, hid_t meta_dxpl_id, hid_t raw_dxpl_id);
 
 /* Functions that operate on blocks of bytes wrt super block */
 H5_DLL herr_t H5F_block_read(const H5F_t *f, H5FD_mem_t type, haddr_t addr,
diff --git a/src/H5Fpublic.h b/src/H5Fpublic.h
index c57a821..f87aaad 100644
--- a/src/H5Fpublic.h
+++ b/src/H5Fpublic.h
@@ -182,6 +182,17 @@ typedef enum H5F_libver_t {
 } H5F_libver_t;
 
 /* File space handling strategy */
+typedef enum H5F_fspace_strategy_t {
+    H5F_FSPACE_STRATEGY_FSM_AGGR = 0,   /* Mechanisms: free-space managers, aggregators, and virtual file drivers */
+                                        /* This is the library default when not set */
+    H5F_FSPACE_STRATEGY_PAGE = 1,   /* Mechanisms: free-space managers with embedded paged aggregation and virtual file drivers */
+    H5F_FSPACE_STRATEGY_AGGR = 2,   /* Mechanisms: aggregators and virtual file drivers */
+    H5F_FSPACE_STRATEGY_NONE = 3,   /* Mechanisms: virtual file drivers */
+    H5F_FSPACE_STRATEGY_NTYPES      /* must be last */
+} H5F_fspace_strategy_t;
+
+/* Deprecated: File space handling strategy for release 1.10.0 */
+/* They are mapped to H5F_fspace_strategy_t as defined above from release 1.10.1 onwards */
 typedef enum H5F_file_space_type_t {
     H5F_FILE_SPACE_DEFAULT = 0,     /* Default (or current) free space strategy setting */
     H5F_FILE_SPACE_ALL_PERSIST = 1, /* Persistent free space managers, aggregators, virtual file driver */
@@ -253,6 +264,10 @@ H5_DLL herr_t H5Fget_mdc_logging_status(hid_t file_id,
                                         /*OUT*/ hbool_t *is_enabled,
                                         /*OUT*/ hbool_t *is_currently_logging);
 H5_DLL herr_t H5Fformat_convert(hid_t fid);
+H5_DLL herr_t H5Freset_page_buffering_stats(hid_t file_id);
+H5_DLL herr_t H5Fget_page_buffering_stats(hid_t file_id, unsigned accesses[2],
+    unsigned hits[2], unsigned misses[2], unsigned evictions[2], unsigned bypasses[2]);
+
 #ifdef H5_HAVE_PARALLEL
 H5_DLL herr_t H5Fset_mpi_atomicity(hid_t file_id, hbool_t flag);
 H5_DLL herr_t H5Fget_mpi_atomicity(hid_t file_id, hbool_t *flag);
diff --git a/src/H5Fquery.c b/src/H5Fquery.c
index 14dd655..34fe8f9 100644
--- a/src/H5Fquery.c
+++ b/src/H5Fquery.c
@@ -1235,3 +1235,150 @@ H5F_mdc_log_location(const H5F_t *f)
     FUNC_LEAVE_NOAPI(f->shared->mdc_log_location)
 } /* end H5F_mdc_log_location() */
 
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_get_alignment
+ *
+ * Purpose:	Retrieve the 'alignment' for the file.
+ *
+ * Return:	Success:	Non-negative, the 'alignment'
+ *
+ * 		Failure:	(can't happen)
+ *
+ * Programmer:	Vailin Choi; Dec 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+hsize_t
+H5F_get_alignment(const H5F_t *f)
+{
+    /* Use FUNC_ENTER_NOAPI_NOINIT_NOERR here to avoid performance issues */
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    HDassert(f);
+    HDassert(f->shared);
+
+    FUNC_LEAVE_NOAPI(f->shared->alignment)
+} /* end H5F_get_alignment() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_get_threshold
+ *
+ * Purpose:	Retrieve the 'threshold' for alignment in the file.
+ *
+ * Return:	Success:	Non-negative, the 'threshold'
+ *
+ * 		Failure:	(can't happen)
+ *
+ * Programmer:	Vailin Choi; Dec 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+hsize_t
+H5F_get_threshold(const H5F_t *f)
+{
+    /* Use FUNC_ENTER_NOAPI_NOINIT_NOERR here to avoid performance issues */
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    HDassert(f);
+    HDassert(f->shared);
+
+    FUNC_LEAVE_NOAPI(f->shared->threshold)
+} /* end H5F_get_threshold() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_get_pgend_meta_thres
+ *
+ * Purpose:	Retrieve the 'page end meta threshold size' for the file.
+ *
+ * Return:	Success:	Non-negative, the 'pgend_meta_thres'
+ *
+ * 		Failure:	(can't happen)
+ *
+ * Programmer:	Vailin Choi; Dec 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+hsize_t
+H5F_get_pgend_meta_thres(const H5F_t *f)
+{
+    /* Use FUNC_ENTER_NOAPI_NOINIT_NOERR here to avoid performance issues */
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    HDassert(f);
+    HDassert(f->shared);
+
+    FUNC_LEAVE_NOAPI(f->shared->pgend_meta_thres)
+} /* end H5F_get_pgend_meta_thres() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_get_point_of_no_return
+ *
+ * Purpose:	Retrieve the 'point of no return' value for the file.
+ *
+ * Return:	Success:	Non-negative, the 'point_of_no_return'
+ * 		Failure:	(can't happen)
+ *
+ *-------------------------------------------------------------------------
+ */
+hbool_t
+H5F_get_point_of_no_return(const H5F_t *f)
+{
+    /* Use FUNC_ENTER_NOAPI_NOINIT_NOERR here to avoid performance issues */
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    HDassert(f);
+    HDassert(f->shared);
+
+    FUNC_LEAVE_NOAPI(f->shared->point_of_no_return)
+} /* end H5F_get_point_of_no_return() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_get_first_alloc_dealloc
+ *
+ * Purpose:	Retrieve the 'first alloc / dealloc' value for the file.
+ *
+ * Return:	Success:	Non-negative, the 'first_alloc_dealloc'
+ * 		Failure:	(can't happen)
+ *
+ *-------------------------------------------------------------------------
+ */
+hbool_t
+H5F_get_first_alloc_dealloc(const H5F_t *f)
+{
+    /* Use FUNC_ENTER_NOAPI_NOINIT_NOERR here to avoid performance issues */
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    HDassert(f);
+    HDassert(f->shared);
+
+    FUNC_LEAVE_NOAPI(f->shared->first_alloc_dealloc)
+} /* end H5F_get_first_alloc_dealloc() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_get_eoa_pre_fsm_fsalloc
+ *
+ * Purpose:	Retrieve the 'EOA pre-FSM fsalloc' value for the file.
+ *
+ * Return:	Success:	Non-negative, the 'EOA pre-FSM fsalloc'
+ * 		Failure:	(can't happen)
+ *
+ *-------------------------------------------------------------------------
+ */
+hbool_t
+H5F_get_eoa_pre_fsm_fsalloc(const H5F_t *f)
+{
+    /* Use FUNC_ENTER_NOAPI_NOINIT_NOERR here to avoid performance issues */
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    HDassert(f);
+    HDassert(f->shared);
+
+    FUNC_LEAVE_NOAPI(f->shared->eoa_pre_fsm_fsalloc)
+} /* end H5F_get_eoa_pre_fsm_fsalloc() */
+
diff --git a/src/H5Fspace.c b/src/H5Fspace.c
new file mode 100644
index 0000000..53570f6
--- /dev/null
+++ b/src/H5Fspace.c
@@ -0,0 +1,226 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * Copyright by the Board of Trustees of the University of Illinois.         *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the files COPYING and Copyright.html.  COPYING can be found at the root   *
+ * of the source code distribution tree; Copyright.html can be found at the  *
+ * root level of an installed copy of the electronic HDF5 document set and   *
+ * is linked from the top-level documents page.  It can also be found at     *
+ * http://hdfgroup.org/HDF5/doc/Copyright.html.  If you do not have          *
+ * access to either file, you may request a copy from help@hdfgroup.org.     *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*-------------------------------------------------------------------------
+ *
+ * Created:		H5Fspace.c
+ *			Dec 30 2013
+ *			Quincey Koziol <koziol@hdfgroup.org>
+ *
+ * Purpose:		Space allocation routines for the file.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+/****************/
+/* Module Setup */
+/****************/
+
+#include "H5Fmodule.h"          /* This source code file is part of the H5F module */
+
+
+/***********/
+/* Headers */
+/***********/
+#include "H5private.h"		/* Generic Functions			*/
+#include "H5Eprivate.h"		/* Error handling		  	*/
+#include "H5Fpkg.h"         	/* File access				*/
+#include "H5FDprivate.h"	/* File drivers				*/
+
+
+/****************/
+/* Local Macros */
+/****************/
+
+
+/******************/
+/* Local Typedefs */
+/******************/
+
+
+/********************/
+/* Package Typedefs */
+/********************/
+
+
+/********************/
+/* Local Prototypes */
+/********************/
+
+
+/*********************/
+/* Package Variables */
+/*********************/
+
+
+/*****************************/
+/* Library Private Variables */
+/*****************************/
+
+
+/*******************/
+/* Local Variables */
+/*******************/
+
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5F_alloc
+ *
+ * Purpose:     Wrapper for H5FD_alloc, to make certain EOA changes are
+ *		reflected in superblock.
+ *
+ * Note:	When the metadata cache routines are updated to allow
+ *		marking an entry dirty without a H5F_t*, this routine should
+ *		be changed to take a H5F_super_t* directly.
+ *
+ * Return:      Success:    The format address of the new file memory.
+ *              Failure:    The undefined address HADDR_UNDEF
+ *
+ * Programmer:  Quincey Koziol
+ *              Monday, December 30, 2013
+ *
+ *-------------------------------------------------------------------------
+ */
+haddr_t
+H5F_alloc(H5F_t *f, hid_t dxpl_id, H5F_mem_t type, hsize_t size, haddr_t *frag_addr, hsize_t *frag_size)
+{
+    haddr_t     ret_value = 0;          /* Return value */
+
+    FUNC_ENTER_NOAPI(HADDR_UNDEF)
+
+    /* check args */
+    HDassert(f);
+    HDassert(f->shared);
+    HDassert(f->shared->lf);
+    HDassert(type >= H5FD_MEM_DEFAULT && type < H5FD_MEM_NTYPES);
+    HDassert(size > 0);
+
+    /* Check whether the file can use temporary addresses */
+    if(f->shared->use_tmp_space) {
+        haddr_t	eoa;            /* Current EOA for the file */
+
+        /* Get the EOA for the file */
+        if(HADDR_UNDEF == (eoa = H5F_get_eoa(f, type)))
+            HGOTO_ERROR(H5E_FILE, H5E_CANTGET, HADDR_UNDEF, "Unable to get eoa")
+
+        /* Check for overlapping into file's temporary allocation space */
+        if(H5F_addr_gt((eoa + size), f->shared->tmp_addr))
+            HGOTO_ERROR(H5E_FILE, H5E_BADRANGE, HADDR_UNDEF, "'normal' file space allocation request will overlap into 'temporary' file space")
+    } /* end if */
+
+    /* Call the file driver 'alloc' routine */
+    ret_value = H5FD_alloc(f->shared->lf, dxpl_id, type, f, size, frag_addr, frag_size);
+    if(!H5F_addr_defined(ret_value))
+        HGOTO_ERROR(H5E_FILE, H5E_CANTALLOC, HADDR_UNDEF, "file driver 'alloc' request failed")
+
+    /* Mark EOA dirty */
+    if(H5F_eoa_dirty(f, dxpl_id) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTMARKDIRTY, HADDR_UNDEF, "unable to mark EOA as dirty")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5F_alloc() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5F_free
+ *
+ * Purpose:     Wrapper for H5FD_free, to make certain EOA changes are
+ *		reflected in superblock.
+ *
+ * Note:	When the metadata cache routines are updated to allow
+ *		marking an entry dirty without a H5F_t*, this routine should
+ *		be changed to take a H5F_super_t* directly.
+ *
+ * Return:      Success:        Non-negative
+ *              Failure:        Negative
+ *
+ * Programmer:  Quincey Koziol
+ *              Monday, December 30, 2013
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5F_free(H5F_t *f, hid_t dxpl_id, H5FD_mem_t type, haddr_t addr, hsize_t size)
+{
+    herr_t      ret_value = SUCCEED;       /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Check args */
+    HDassert(f);
+    HDassert(f->shared);
+    HDassert(f->shared->lf);
+    HDassert(type >= H5FD_MEM_DEFAULT && type < H5FD_MEM_NTYPES);
+    HDassert(size > 0);
+
+    /* Call the file driver 'free' routine */
+    if(H5FD_free(f->shared->lf, dxpl_id, type, f, addr, size) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTFREE, FAIL, "file driver 'free' request failed")
+
+    /* Mark EOA dirty */
+    if(H5F_eoa_dirty(f, dxpl_id) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTMARKDIRTY, FAIL, "unable to mark EOA as dirty")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5F_free() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5F_try_extend
+ *
+ * Purpose:	Extend a block at the end of the file, if possible.
+ *
+ * Note:	When the metadata cache routines are updated to allow
+ *		marking an entry dirty without a H5F_t*, this routine should
+ *		be changed to take a H5F_super_t* directly.
+ *
+ * Return:	Success:	TRUE(1)  - Block was extended
+ *                              FALSE(0) - Block could not be extended
+ * 		Failure:	FAIL
+ *
+ * Programmer:  Quincey Koziol
+ *              Monday, 30 December, 2013
+ *
+ *-------------------------------------------------------------------------
+ */
+htri_t
+H5F_try_extend(H5F_t *f, hid_t dxpl_id, H5FD_mem_t type, haddr_t blk_end, hsize_t extra_requested)
+{
+    htri_t ret_value = FALSE;   /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* check args */
+    HDassert(f);
+    HDassert(f->shared);
+    HDassert(f->shared->lf);
+    HDassert(type >= H5FD_MEM_DEFAULT && type < H5FD_MEM_NTYPES);
+    HDassert(extra_requested > 0);
+
+    /* Extend the object by extending the underlying file */
+    if((ret_value = H5FD_try_extend(f->shared->lf, type, f, dxpl_id, blk_end, extra_requested)) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTEXTEND, FAIL, "driver try extend request failed")
+
+    /* H5FD_try_extend() updates driver message and marks the superblock
+     * dirty, so no need to do it again here.
+     */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5F_try_extend() */
+
diff --git a/src/H5Fsuper.c b/src/H5Fsuper.c
index 3b86dae..58ef9bb 100644
--- a/src/H5Fsuper.c
+++ b/src/H5Fsuper.c
@@ -29,6 +29,7 @@
 #include "H5Fpkg.h"             /* File access                          */
 #include "H5FDprivate.h"	/* File drivers                         */
 #include "H5Iprivate.h"		/* IDs                                  */
+#include "H5MFprivate.h"        /* File memory management               */
 #include "H5MMprivate.h"	/* Memory management			*/
 #include "H5Pprivate.h"		/* Property lists                       */
 #include "H5SMprivate.h"        /* Shared Object Header Messages        */
@@ -320,13 +321,14 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5F__super_read(H5F_t *f, hid_t dxpl_id, hbool_t initial_read)
+H5F__super_read(H5F_t *f, hid_t meta_dxpl_id, hid_t raw_dxpl_id, hbool_t initial_read)
 {
     H5P_genplist_t     *dxpl = NULL;        /* DXPL object */
     H5AC_ring_t         ring, orig_ring = H5AC_RING_INV;
     H5F_super_t *       sblock = NULL;      /* Superblock structure */
     H5F_superblock_cache_ud_t udata;        /* User data for cache callbacks */
     H5P_genplist_t     *c_plist;            /* File creation property list  */
+    H5FD_io_info_t      fdio_info;          /* File driver I/O info */
     unsigned            sblock_flags = H5AC__NO_FLAGS_SET;       /* flags used in superblock unprotect call      */
     haddr_t             super_addr;         /* Absolute address of superblock */
     haddr_t             eof;                /* End of file address */
@@ -334,7 +336,7 @@ H5F__super_read(H5F_t *f, hid_t dxpl_id, hbool_t initial_read)
     hbool_t 		skip_eof_check = FALSE; /* Whether to skip checking the EOF value */
     herr_t              ret_value = SUCCEED; /* Return value */
 
-    FUNC_ENTER_PACKAGE_TAG(dxpl_id, H5AC__SUPERBLOCK_TAG, FAIL)
+    FUNC_ENTER_PACKAGE_TAG(meta_dxpl_id, H5AC__SUPERBLOCK_TAG, FAIL)
 
     /* initialize the drvinfo to NULL -- we will overwrite this if there
      * is a driver information block 
@@ -342,13 +344,19 @@ H5F__super_read(H5F_t *f, hid_t dxpl_id, hbool_t initial_read)
     f->shared->drvinfo = NULL;
 
     /* Get the DXPL plist object for DXPL ID */
-    if(NULL == (dxpl = (H5P_genplist_t *)H5I_object(dxpl_id)))
+    if(NULL == (dxpl = (H5P_genplist_t *)H5I_object(meta_dxpl_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
     if((H5P_get(dxpl, H5AC_RING_NAME, &orig_ring)) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "unable to get property value");
 
+    /* Set up file driver I/O info */
+    fdio_info.file = f->shared->lf;
+    fdio_info.meta_dxpl = dxpl;
+    if(NULL == (fdio_info.raw_dxpl = (H5P_genplist_t *)H5I_object(raw_dxpl_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+
     /* Find the superblock */
-    if(H5FD_locate_signature(f->shared->lf, dxpl, &super_addr) < 0)
+    if(H5FD_locate_signature(&fdio_info, &super_addr) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_NOTHDF5, FAIL, "unable to locate file signature")
     if(HADDR_UNDEF == super_addr)
         HGOTO_ERROR(H5E_FILE, H5E_NOTHDF5, FAIL, "file signature not found")
@@ -396,7 +404,7 @@ H5F__super_read(H5F_t *f, hid_t dxpl_id, hbool_t initial_read)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "unable to set property value");
 
     /* Look up the superblock */
-    if(NULL == (sblock = (H5F_super_t *)H5AC_protect(f, dxpl_id, H5AC_SUPERBLOCK, (haddr_t)0, &udata, rw_flags)))
+    if(NULL == (sblock = (H5F_super_t *)H5AC_protect(f, meta_dxpl_id, H5AC_SUPERBLOCK, (haddr_t)0, &udata, rw_flags)))
         HGOTO_ERROR(H5E_FILE, H5E_CANTPROTECT, FAIL, "unable to load superblock")
 
     if(H5F_INTENT(f) & H5F_ACC_SWMR_WRITE)
@@ -556,7 +564,7 @@ H5F__super_read(H5F_t *f, hid_t dxpl_id, hbool_t initial_read)
             HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "set end of space allocation request failed")
 
         /* Look up the driver info block */
-        if(NULL == (drvinfo = (H5O_drvinfo_t *)H5AC_protect(f, dxpl_id, H5AC_DRVRINFO, sblock->driver_addr, &drvrinfo_udata, rw_flags)))
+        if(NULL == (drvinfo = (H5O_drvinfo_t *)H5AC_protect(f, meta_dxpl_id, H5AC_DRVRINFO, sblock->driver_addr, &drvrinfo_udata, rw_flags)))
             HGOTO_ERROR(H5E_FILE, H5E_CANTPROTECT, FAIL, "unable to load driver info block")
 
         /* Loading the driver info block is enough to set up the right info */
@@ -571,7 +579,7 @@ H5F__super_read(H5F_t *f, hid_t dxpl_id, hbool_t initial_read)
         drvinfo_flags |= H5AC__PIN_ENTRY_FLAG;
 
         /* Release the driver info block */
-        if(H5AC_unprotect(f, dxpl_id, H5AC_DRVRINFO, sblock->driver_addr, drvinfo, drvinfo_flags) < 0)
+        if(H5AC_unprotect(f, meta_dxpl_id, H5AC_DRVRINFO, sblock->driver_addr, drvinfo, drvinfo_flags) < 0)
             HGOTO_ERROR(H5E_FILE, H5E_CANTUNPROTECT, FAIL, "unable to release driver info block")
 
         /* save a pointer to the driver information cache entry */
@@ -612,14 +620,14 @@ H5F__super_read(H5F_t *f, hid_t dxpl_id, hbool_t initial_read)
             HGOTO_ERROR(H5E_FILE, H5E_CANTOPENOBJ, FAIL, "unable to open file's superblock extension")
 
         /* Check for the extension having a 'driver info' message */
-        if((status = H5O_msg_exists(&ext_loc, H5O_DRVINFO_ID, dxpl_id)) < 0)
+        if((status = H5O_msg_exists(&ext_loc, H5O_DRVINFO_ID, meta_dxpl_id)) < 0)
             HGOTO_ERROR(H5E_FILE, H5E_EXISTS, FAIL, "unable to read object header")
         if(status) {
             /* Check for ignoring the driver info for this file */
             if(!udata.ignore_drvrinfo) {
 
                 /* Retrieve the 'driver info' structure */
-                if(NULL == H5O_msg_read(&ext_loc, H5O_DRVINFO_ID, &drvinfo, dxpl_id))
+                if(NULL == H5O_msg_read(&ext_loc, H5O_DRVINFO_ID, &drvinfo, meta_dxpl_id))
                     HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "driver info message not present")
 
                 /* Validate and decode driver information */
@@ -637,15 +645,15 @@ H5F__super_read(H5F_t *f, hid_t dxpl_id, hbool_t initial_read)
         } /* end if */
 
         /* Read in the shared OH message information if there is any */
-        if(H5SM_get_info(&ext_loc, c_plist, dxpl_id) < 0)
+        if(H5SM_get_info(&ext_loc, c_plist, meta_dxpl_id) < 0)
             HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "unable to read SOHM table information")
 
         /* Check for the extension having a 'v1 B-tree "K"' message */
-        if((status = H5O_msg_exists(&ext_loc, H5O_BTREEK_ID, dxpl_id)) < 0)
+        if((status = H5O_msg_exists(&ext_loc, H5O_BTREEK_ID, meta_dxpl_id)) < 0)
             HGOTO_ERROR(H5E_FILE, H5E_EXISTS, FAIL, "unable to read object header")
         if(status) {
             /* Retrieve the 'v1 B-tree "K"' structure */
-            if(NULL == H5O_msg_read(&ext_loc, H5O_BTREEK_ID, &btreek, dxpl_id))
+            if(NULL == H5O_msg_read(&ext_loc, H5O_BTREEK_ID, &btreek, meta_dxpl_id))
                 HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "v1 B-tree 'K' info message not present")
 
             /* Set non-default v1 B-tree 'K' value info from file */
@@ -661,39 +669,105 @@ H5F__super_read(H5F_t *f, hid_t dxpl_id, hbool_t initial_read)
         } /* end if */
 
         /* Check for the extension having a 'free-space manager info' message */
-        if((status = H5O_msg_exists(&ext_loc, H5O_FSINFO_ID, dxpl_id)) < 0)
+        if((status = H5O_msg_exists(&ext_loc, H5O_FSINFO_ID, meta_dxpl_id)) < 0)
             HGOTO_ERROR(H5E_FILE, H5E_EXISTS, FAIL, "unable to read object header")
         if(status) {
-            H5O_fsinfo_t fsinfo;    /* Free-space manager info message from superblock extension */
+            H5O_fsinfo_t fsinfo;   /* File space info message from superblock extension */
+            uint8_t flags;          /* Message flags */
 
-            /* Retrieve the 'free-space manager info' structure */
-	    if(NULL == H5O_msg_read(&ext_loc, H5O_FSINFO_ID, &fsinfo, dxpl_id))
-                HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "unable to get free-space manager info message")
+            /* Get message flags */
+            if(H5O_msg_get_flags(&ext_loc, H5O_FSINFO_ID, meta_dxpl_id, &flags) < 0)
+                HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "unable to message flags for free-space manager info message")
 
-            /* Check for non-default info */
-	    if(f->shared->fs_strategy != fsinfo.strategy) {
-		f->shared->fs_strategy = fsinfo.strategy;
+            /* If message is NOT marked "unknown"--set up file space info  */
+            if(!(flags & H5O_MSG_FLAG_WAS_UNKNOWN)) {
 
-		/* Set non-default strategy in the property list */
-		if(H5P_set(c_plist, H5F_CRT_FILE_SPACE_STRATEGY_NAME, &fsinfo.strategy) < 0)
-		    HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "unable to set file space strategy")
-	    } /* end if */
-	    if(f->shared->fs_threshold != fsinfo.threshold) {
-		f->shared->fs_threshold = fsinfo.threshold;
+                /* Retrieve the 'file space info' structure */
+                if(NULL == H5O_msg_read(&ext_loc, H5O_FSINFO_ID, &fsinfo, meta_dxpl_id))
+                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "unable to get free-space manager info message")
 
-		/* Set non-default threshold in the property list */
-		if(H5P_set(c_plist, H5F_CRT_FREE_SPACE_THRESHOLD_NAME, &fsinfo.threshold) < 0)
-		    HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "unable to set file space strategy")
-	    } /* end if */
+                /* Update changed values */
+                if(f->shared->fs_strategy != fsinfo.strategy) {
+                    f->shared->fs_strategy = fsinfo.strategy;
+
+                    /* Set non-default strategy in the property list */
+                    if(H5P_set(c_plist, H5F_CRT_FILE_SPACE_STRATEGY_NAME, &fsinfo.strategy) < 0)
+                        HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "unable to set file space strategy")
+                } /* end if */
+                if(f->shared->fs_persist != fsinfo.persist) {
+                    f->shared->fs_persist = fsinfo.persist;
+
+                    /* Set non-default strategy in the property list */
+                    if(H5P_set(c_plist, H5F_CRT_FREE_SPACE_PERSIST_NAME, &fsinfo.persist) < 0)
+                        HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "unable to set file space strategy")
+                } /* end if */
+                if(f->shared->fs_threshold != fsinfo.threshold) {
+                    f->shared->fs_threshold = fsinfo.threshold;
+
+                    /* Set non-default threshold in the property list */
+                    if(H5P_set(c_plist, H5F_CRT_FREE_SPACE_THRESHOLD_NAME, &fsinfo.threshold) < 0)
+                        HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "unable to set file space strategy")
+                } /* end if */
+
+                HDassert(f->shared->fs_page_size >= H5F_FILE_SPACE_PAGE_SIZE_MIN);
+                HDassert(fsinfo.page_size >= H5F_FILE_SPACE_PAGE_SIZE_MIN);
+                if(f->shared->fs_page_size != fsinfo.page_size) {
+                    f->shared->fs_page_size = fsinfo.page_size;
+
+                    /* Set file space page size in the property list */
+                    if(H5P_set(c_plist, H5F_CRT_FILE_SPACE_PAGE_SIZE_NAME, &fsinfo.page_size) < 0)
+                        HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "unable to set file space page size")
+                } /* end if */
+                if(f->shared->pgend_meta_thres != fsinfo.pgend_meta_thres)
+                    /* Initialize page end meta threshold */
+                    f->shared->pgend_meta_thres = fsinfo.pgend_meta_thres;
+
+                if(f->shared->eoa_pre_fsm_fsalloc != fsinfo.eoa_pre_fsm_fsalloc)
+                    f->shared->eoa_pre_fsm_fsalloc = fsinfo.eoa_pre_fsm_fsalloc;
+
+                /* f->shared->eoa_pre_fsm_fsalloc must always be HADDR_UNDEF
+                 * in the absence of persistant free space managers.
+                 */
+                HDassert((!f->shared->fs_persist) || (f->shared->eoa_pre_fsm_fsalloc != HADDR_UNDEF));
+                HDassert(!f->shared->first_alloc_dealloc);
+
+                if((f->shared->eoa_pre_fsm_fsalloc != HADDR_UNDEF) &&
+                   (H5F_INTENT(f) & H5F_ACC_RDWR))
+                    f->shared->first_alloc_dealloc = TRUE;
+
+                f->shared->fs_addr[0] = HADDR_UNDEF;
+                for(u = 1; u < NELMTS(f->shared->fs_addr); u++)
+                    f->shared->fs_addr[u] = fsinfo.fs_addr[u - 1];
 
-	    /* Set free-space manager addresses */
-	    f->shared->fs_addr[0] = HADDR_UNDEF;
-	    for(u = 1; u < NELMTS(f->shared->fs_addr); u++)
-		f->shared->fs_addr[u] = fsinfo.fs_addr[u-1];
+                if(fsinfo.mapped && (rw_flags & H5AC__READ_ONLY_FLAG) == 0) {
+
+                    /* Do the same kluge until we know for sure.  VC */
+#if 1 /* bug fix test code -- tidy this up if all goes well */ /* JRM */
+                    /* KLUGE ALERT!!
+                     *
+                     * H5F_super_ext_write_msg() expects f->shared->sblock to 
+                     * be set -- verify that it is NULL, and then set it.
+                     * Set it back to NULL when we are done.
+                     */
+                     HDassert(f->shared->sblock == NULL);
+                     f->shared->sblock = sblock;
+#endif /* JRM */
+
+                    if(H5F_super_ext_remove_msg(f, meta_dxpl_id, H5O_FSINFO_ID) < 0)
+                        HGOTO_ERROR(H5E_FILE, H5E_CANTDELETE, FAIL,  "error in removing message from superblock extension")
+
+                    if(H5F_super_ext_write_msg(f, meta_dxpl_id, H5O_FSINFO_ID, &fsinfo, TRUE, H5O_MSG_FLAG_MARK_IF_UNKNOWN) < 0)
+                        HGOTO_ERROR(H5E_FILE, H5E_WRITEERROR, FAIL, "error in writing fsinfo message to superblock extension")
+#if 1 /* bug fix test code -- tidy this up if all goes well */ /* JRM */
+                    f->shared->sblock = NULL;
+#endif /* JRM */
+
+                }
+            } /* end if not marked "unknown" */
         } /* end if */
 
 	/* Check for the extension having a 'metadata cache image' message */
-        if((status = H5O_msg_exists(&ext_loc, H5O_MDCI_MSG_ID, dxpl_id)) < 0)
+        if((status = H5O_msg_exists(&ext_loc, H5O_MDCI_MSG_ID, meta_dxpl_id)) < 0)
             HGOTO_ERROR(H5E_FILE, H5E_EXISTS, FAIL, "unable to read object header")
         if(status) {
             hbool_t 	rw = ((rw_flags & H5AC__READ_ONLY_FLAG) == 0);
@@ -712,7 +786,7 @@ H5F__super_read(H5F_t *f, hid_t dxpl_id, hbool_t initial_read)
              */
 
             /* Retrieve the 'metadata cache image message' structure */
-	    if(NULL == H5O_msg_read(&ext_loc, H5O_MDCI_MSG_ID, &mdci_msg, dxpl_id))
+	    if(NULL == H5O_msg_read(&ext_loc, H5O_MDCI_MSG_ID, &mdci_msg, meta_dxpl_id))
                 HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "unable to get metadata cache image message")
 
             /* Indicate to the cache that there's an image to load on first protect call */
@@ -721,7 +795,7 @@ H5F__super_read(H5F_t *f, hid_t dxpl_id, hbool_t initial_read)
         } /* end if */
 
         /* Close superblock extension */
-        if(H5F_super_ext_close(f, &ext_loc, dxpl_id, FALSE) < 0)
+        if(H5F_super_ext_close(f, &ext_loc, meta_dxpl_id, FALSE) < 0)
 	    HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEOBJ, FAIL, "unable to close file's superblock extension")
     } /* end if */
 
@@ -765,7 +839,7 @@ H5F__super_read(H5F_t *f, hid_t dxpl_id, hbool_t initial_read)
 		HDassert(f->shared->sblock == NULL);
 		f->shared->sblock = sblock;
 #endif /* JRM */
-		if(H5F_super_ext_write_msg(f, dxpl_id, H5O_DRVINFO_ID, &drvinfo, FALSE, H5O_MSG_NO_FLAGS_SET) < 0)
+		if(H5F_super_ext_write_msg(f, meta_dxpl_id, H5O_DRVINFO_ID, &drvinfo, FALSE, H5O_MSG_NO_FLAGS_SET) < 0)
                     HGOTO_ERROR(H5E_FILE, H5E_WRITEERROR, FAIL, "error in writing message to superblock extension")
 
 #if 1 /* bug fix test code -- tidy this up if all goes well */ /* JRM */
@@ -777,7 +851,7 @@ H5F__super_read(H5F_t *f, hid_t dxpl_id, hbool_t initial_read)
         /* Check for eliminating the driver info block */
         else if(H5F_HAS_FEATURE(f, H5FD_FEAT_IGNORE_DRVRINFO)) {
             /* Remove the driver info message from the superblock extension */
-            if(H5F_super_ext_remove_msg(f, dxpl_id, H5O_DRVINFO_ID) < 0)
+            if(H5F_super_ext_remove_msg(f, meta_dxpl_id, H5O_DRVINFO_ID) < 0)
                 HGOTO_ERROR(H5E_FILE, H5E_CANTRELEASE, FAIL, "error in removing message from superblock extension")
 
             /* Check if the superblock extension was removed */
@@ -789,13 +863,17 @@ H5F__super_read(H5F_t *f, hid_t dxpl_id, hbool_t initial_read)
     /* Set the pointer to the pinned superblock */
     f->shared->sblock = sblock;
 
+    /* Set the page aggregation mode */
+    if(H5F__set_paged_aggr(f, (hbool_t)H5F_PAGED_AGGR(f)) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "failed to set paged_aggr status for file driver")
+
 done:
     /* Reset the ring in the DXPL */
     if(H5AC_reset_ring(dxpl, orig_ring) < 0)
         HDONE_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "unable to set property value")
 
     /* Release the superblock */
-    if(sblock && H5AC_unprotect(f, dxpl_id, H5AC_SUPERBLOCK, (haddr_t)0, sblock, sblock_flags) < 0)
+    if(sblock && H5AC_unprotect(f, meta_dxpl_id, H5AC_SUPERBLOCK, (haddr_t)0, sblock, sblock_flags) < 0)
         HDONE_ERROR(H5E_FILE, H5E_CANTUNPROTECT, FAIL, "unable to close superblock")
 
     /* If we have failed, make sure no entries are left in the 
@@ -808,7 +886,7 @@ done:
                 HDONE_ERROR(H5E_FILE, H5E_CANTUNPIN, FAIL, "unable to unpin driver info")
 
             /* Evict the driver info block from the cache */
-            if(H5AC_expunge_entry(f, dxpl_id, H5AC_DRVRINFO, sblock->driver_addr, H5AC__NO_FLAGS_SET) < 0)
+            if(H5AC_expunge_entry(f, meta_dxpl_id, H5AC_DRVRINFO, sblock->driver_addr, H5AC__NO_FLAGS_SET) < 0)
                 HDONE_ERROR(H5E_FILE, H5E_CANTEXPUNGE, FAIL, "unable to expunge driver info block")
         } /* end if */
 
@@ -819,7 +897,7 @@ done:
                 HDONE_ERROR(H5E_FILE, H5E_CANTUNPIN, FAIL, "unable to unpin superblock")
 
             /* Evict the superblock from the cache */
-            if(H5AC_expunge_entry(f, dxpl_id, H5AC_SUPERBLOCK, (haddr_t)0, H5AC__NO_FLAGS_SET) < 0)
+            if(H5AC_expunge_entry(f, meta_dxpl_id, H5AC_SUPERBLOCK, (haddr_t)0, H5AC__NO_FLAGS_SET) < 0)
                 HDONE_ERROR(H5E_FILE, H5E_CANTEXPUNGE, FAIL, "unable to expunge superblock")
         } /* end if */
     } /* end if */
@@ -890,7 +968,9 @@ H5F__super_init(H5F_t *f, hid_t dxpl_id)
 
     /* Check for non-default free-space settings */
     if(!(f->shared->fs_strategy == H5F_FILE_SPACE_STRATEGY_DEF &&
-            f->shared->fs_threshold == H5F_FREE_SPACE_THRESHOLD_DEF))
+            f->shared->fs_persist == H5F_FREE_SPACE_PERSIST_DEF &&
+            f->shared->fs_threshold == H5F_FREE_SPACE_THRESHOLD_DEF &&
+	    f->shared->fs_page_size == H5F_FILE_SPACE_PAGE_SIZE_DEF))
         non_default_fs_settings = TRUE;
 
     /* Bump superblock version if latest superblock version support is enabled */
@@ -899,8 +979,12 @@ H5F__super_init(H5F_t *f, hid_t dxpl_id)
     /* Bump superblock version to create superblock extension for SOHM info */
     else if(f->shared->sohm_nindexes > 0)
         super_vers = HDF5_SUPERBLOCK_VERSION_2;
-    /* Bump superblock version to create superblock extension for
-     * non-default file space strategy or non-default free-space threshold
+    /* 
+     *	Bump superblock version to create superblock extension for:
+     * 	-- non-default file space strategy or 
+     * 	-- non-default persisting free-space or 
+     *  -- non-default free-space threshold or
+     *  -- non-default page_size
      */
     else if(non_default_fs_settings)
         super_vers = HDF5_SUPERBLOCK_VERSION_2;
@@ -921,6 +1005,9 @@ H5F__super_init(H5F_t *f, hid_t dxpl_id)
             HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "unable to set superblock version")
     } /* end if */
 
+    if(H5FD_set_paged_aggr(f->shared->lf, (hbool_t)H5F_PAGED_AGGR(f)) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "failed to set paged_aggr status for file driver")
+
     /*
      * The superblock starts immediately after the user-defined
      * header, which we have already insured is a proper size. The
@@ -932,9 +1019,12 @@ H5F__super_init(H5F_t *f, hid_t dxpl_id)
 
     /* Sanity check the userblock size vs. the file's allocation alignment */
     if(userblock_size > 0) {
-        if(userblock_size < f->shared->alignment)
+	/* Set up the alignment to use for page or aggr fs */
+	hsize_t alignment = H5F_PAGED_AGGR(f) ? f->shared->fs_page_size : f->shared->alignment;
+
+        if(userblock_size < alignment)
             HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "userblock size must be > file object alignment")
-        if(0 != (userblock_size % f->shared->alignment))
+        if(0 != (userblock_size % alignment))
             HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "userblock size must be an integral multiple of file object alignment")
     } /* end if */
 
@@ -990,10 +1080,6 @@ H5F__super_init(H5F_t *f, hid_t dxpl_id)
     if(super_vers < HDF5_SUPERBLOCK_VERSION_2)
         superblock_size += driver_size;
 
-    /* Reserve space in the file for the superblock, instead of allocating it */
-    if(H5F__set_eoa(f, H5FD_MEM_SUPER, superblock_size) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "unable to set EOA value for superblock")
-
     /* Set the ring type in the DXPL */
     if(H5AC_set_ring(dxpl_id, H5AC_RING_SB, &dxpl, &orig_ring) < 0)
         HGOTO_ERROR(H5E_FILE, H5E_CANTSET, FAIL, "unable to set ring value")
@@ -1006,6 +1092,10 @@ H5F__super_init(H5F_t *f, hid_t dxpl_id)
     /* Keep a copy of the superblock info */
     f->shared->sblock = sblock;
 
+    /* Allocate space for the superblock */
+    if(HADDR_UNDEF == H5MF_alloc(f, H5FD_MEM_SUPER, dxpl_id, superblock_size))
+	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "file allocation failed for superblock")
+
     /* set the drvinfo filed to NULL -- will overwrite this later if needed */
     f->shared->drvinfo = NULL;
 
@@ -1108,17 +1198,23 @@ H5F__super_init(H5F_t *f, hid_t dxpl_id)
         } /* end if */
 
         /* Check for non-default free-space info settings */
-	if(non_default_fs_settings) {
-	    H5FD_mem_t   type;         	/* Memory type for iteration */
-            H5O_fsinfo_t fsinfo;	/* Free space manager info message */
-
-	    /* Write free-space manager info message to superblock extension object header if needed */
-	    fsinfo.strategy = f->shared->fs_strategy;
-	    fsinfo.threshold = f->shared->fs_threshold;
-	    for(type = H5FD_MEM_SUPER; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type))
-                fsinfo.fs_addr[type-1] = HADDR_UNDEF;
-
-	    if(H5O_msg_create(&ext_loc, H5O_FSINFO_ID, H5O_MSG_FLAG_DONTSHARE, H5O_UPDATE_TIME, &fsinfo, dxpl_id) < 0)
+        if(non_default_fs_settings) {
+            H5F_mem_page_t ptype;
+            H5O_fsinfo_t fsinfo;    /* Free space manager info message */
+
+            /* Write free-space manager info message to superblock extension object header if needed */
+            fsinfo.strategy = f->shared->fs_strategy;
+            fsinfo.persist = f->shared->fs_persist;
+            fsinfo.threshold = f->shared->fs_threshold;
+            fsinfo.page_size = f->shared->fs_page_size;
+            fsinfo.pgend_meta_thres = f->shared->pgend_meta_thres;
+            fsinfo.eoa_pre_fsm_fsalloc = HADDR_UNDEF;
+            fsinfo.mapped = FALSE;
+
+            for(ptype = H5F_MEM_PAGE_SUPER; ptype < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, ptype))
+                fsinfo.fs_addr[ptype - 1] = HADDR_UNDEF;
+
+            if(H5O_msg_create(&ext_loc, H5O_FSINFO_ID, H5O_MSG_FLAG_DONTSHARE | H5O_MSG_FLAG_MARK_IF_UNKNOWN, H5O_UPDATE_TIME, &fsinfo, dxpl_id) < 0)
                 HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "unable to update free-space info header message")
 	} /* end if */
     } /* end if */
diff --git a/src/H5HFsection.c b/src/H5HFsection.c
index 37ff8f4..b113ca1 100644
--- a/src/H5HFsection.c
+++ b/src/H5HFsection.c
@@ -85,14 +85,14 @@ static herr_t H5HF_sect_single_full_dblock(H5HF_hdr_t *hdr, hid_t dxpl_id,
     H5HF_free_section_t *sect);
 
 /* 'single' section callbacks */
-static herr_t H5HF_sect_single_add(H5FS_section_info_t *sect, unsigned *flags,
+static herr_t H5HF_sect_single_add(H5FS_section_info_t **sect, unsigned *flags,
     void *udata);
 static H5FS_section_info_t *H5HF_sect_single_deserialize(const H5FS_section_class_t *cls,
     hid_t dxpl_id, const uint8_t *buf, haddr_t sect_addr, hsize_t sect_size,
     unsigned *des_flags);
 static htri_t H5HF_sect_single_can_merge(const H5FS_section_info_t *sect1,
     const H5FS_section_info_t *sect2, void *udata);
-static herr_t H5HF_sect_single_merge(H5FS_section_info_t *sect1,
+static herr_t H5HF_sect_single_merge(H5FS_section_info_t **sect1,
     H5FS_section_info_t *sect2, void *udata);
 static htri_t H5HF_sect_single_can_shrink(const H5FS_section_info_t *sect,
     void *udata);
@@ -121,7 +121,7 @@ static H5FS_section_info_t *H5HF_sect_row_deserialize(const H5FS_section_class_t
     unsigned *des_flags);
 static htri_t H5HF_sect_row_can_merge(const H5FS_section_info_t *sect1,
     const H5FS_section_info_t *sect2, void *udata);
-static herr_t H5HF_sect_row_merge(H5FS_section_info_t *sect1,
+static herr_t H5HF_sect_row_merge(H5FS_section_info_t **sect1,
     H5FS_section_info_t *sect2, void *udata);
 static htri_t H5HF_sect_row_can_shrink(const H5FS_section_info_t *sect,
     void *udata);
@@ -811,7 +811,7 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5HF_sect_single_add(H5FS_section_info_t *_sect, unsigned *flags, void *_udata)
+H5HF_sect_single_add(H5FS_section_info_t **_sect, unsigned *flags, void *_udata)
 {
     herr_t ret_value = SUCCEED;         /* Return value */
 
@@ -821,7 +821,7 @@ H5HF_sect_single_add(H5FS_section_info_t *_sect, unsigned *flags, void *_udata)
      *  have already been checked when it was first added
      */
     if(!(*flags & H5FS_ADD_DESERIALIZING)) {
-        H5HF_free_section_t *sect = (H5HF_free_section_t *)_sect;   /* Fractal heap free section */
+        H5HF_free_section_t **sect = (H5HF_free_section_t **)_sect;   /* Fractal heap free section */
         H5HF_sect_add_ud_t *udata = (H5HF_sect_add_ud_t *)_udata;   /* User callback data */
         H5HF_hdr_t *hdr = udata->hdr;       /* Fractal heap header */
         hid_t dxpl_id = udata->dxpl_id;     /* DXPL ID for operation */
@@ -832,14 +832,14 @@ H5HF_sect_single_add(H5FS_section_info_t *_sect, unsigned *flags, void *_udata)
 
         /* Check if single section covers entire direct block it's in */
         /* (converts to row section possibly) */
-        if(H5HF_sect_single_full_dblock(hdr, dxpl_id, sect) < 0)
+        if(H5HF_sect_single_full_dblock(hdr, dxpl_id, (*sect)) < 0)
             HGOTO_ERROR(H5E_HEAP, H5E_CANTCONVERT, FAIL, "can't check/convert single section")
 
         /* Set the "returned space" flag if the single section was changed
          *      into a row section, so the "merging & shrinking" algorithm
          *      gets executed in the free space manager
          */
-        if(sect->sect_info.type != H5HF_FSPACE_SECT_SINGLE)
+        if((*sect)->sect_info.type != H5HF_FSPACE_SECT_SINGLE)
             *flags |= H5FS_ADD_RETURNED_SPACE;
     } /* end if */
 
@@ -949,10 +949,10 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5HF_sect_single_merge(H5FS_section_info_t *_sect1, H5FS_section_info_t *_sect2,
+H5HF_sect_single_merge(H5FS_section_info_t **_sect1, H5FS_section_info_t *_sect2,
     void *_udata)
 {
-    H5HF_free_section_t *sect1 = (H5HF_free_section_t *)_sect1;   /* Fractal heap free section */
+    H5HF_free_section_t **sect1 = (H5HF_free_section_t **)_sect1;   /* Fractal heap free section */
     H5HF_free_section_t *sect2 = (H5HF_free_section_t *)_sect2;   /* Fractal heap free section */
     H5HF_sect_add_ud_t *udata = (H5HF_sect_add_ud_t *)_udata;   /* User callback data */
     H5HF_hdr_t *hdr = udata->hdr;       /* Fractal heap header */
@@ -963,26 +963,26 @@ H5HF_sect_single_merge(H5FS_section_info_t *_sect1, H5FS_section_info_t *_sect2,
 
     /* Check arguments. */
     HDassert(sect1);
-    HDassert(sect1->sect_info.type == H5HF_FSPACE_SECT_SINGLE);
+    HDassert((*sect1)->sect_info.type == H5HF_FSPACE_SECT_SINGLE);
     HDassert(sect2);
     HDassert(sect2->sect_info.type == H5HF_FSPACE_SECT_SINGLE);
-    HDassert(H5F_addr_eq(sect1->sect_info.addr + sect1->sect_info.size, sect2->sect_info.addr));
+    HDassert(H5F_addr_eq((*sect1)->sect_info.addr + (*sect1)->sect_info.size, sect2->sect_info.addr));
 
     /* Add second section's size to first section */
-    sect1->sect_info.size += sect2->sect_info.size;
+    (*sect1)->sect_info.size += sect2->sect_info.size;
 
     /* Get rid of second section */
     if(H5HF_sect_single_free((H5FS_section_info_t *)sect2) < 0)
         HGOTO_ERROR(H5E_HEAP, H5E_CANTRELEASE, FAIL, "can't free section node")
 
     /* Check to see if we should revive first section */
-    if(sect1->sect_info.state != H5FS_SECT_LIVE)
-        if(H5HF_sect_single_revive(hdr, dxpl_id, sect1) < 0)
+    if((*sect1)->sect_info.state != H5FS_SECT_LIVE)
+        if(H5HF_sect_single_revive(hdr, dxpl_id, (*sect1)) < 0)
             HGOTO_ERROR(H5E_HEAP, H5E_CANTINIT, FAIL, "can't revive single free section")
 
     /* Check if single section covers entire direct block it's in */
     /* (converts to row section possibly) */
-    if(H5HF_sect_single_full_dblock(hdr, dxpl_id, sect1) < 0)
+    if(H5HF_sect_single_full_dblock(hdr, dxpl_id, (*sect1)) < 0)
         HGOTO_ERROR(H5E_HEAP, H5E_CANTCONVERT, FAIL, "can't check/convert single section")
 
 done:
@@ -1771,10 +1771,10 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5HF_sect_row_merge(H5FS_section_info_t *_sect1, H5FS_section_info_t *_sect2,
+H5HF_sect_row_merge(H5FS_section_info_t **_sect1, H5FS_section_info_t *_sect2,
     void *_udata)
 {
-    H5HF_free_section_t *sect1 = (H5HF_free_section_t *)_sect1;   /* Fractal heap free section */
+    H5HF_free_section_t **sect1 = (H5HF_free_section_t **)_sect1;   /* Fractal heap free section */
     H5HF_free_section_t *sect2 = (H5HF_free_section_t *)_sect2;   /* Fractal heap free section */
     H5HF_sect_add_ud_t *udata = (H5HF_sect_add_ud_t *)_udata;   /* User callback data */
     H5HF_hdr_t *hdr = udata->hdr;       /* Fractal heap header */
@@ -1785,7 +1785,7 @@ H5HF_sect_row_merge(H5FS_section_info_t *_sect1, H5FS_section_info_t *_sect2,
 
     /* Check arguments. */
     HDassert(sect1);
-    HDassert(sect1->sect_info.type == H5HF_FSPACE_SECT_FIRST_ROW);
+    HDassert((*sect1)->sect_info.type == H5HF_FSPACE_SECT_FIRST_ROW);
     HDassert(sect2);
     HDassert(sect2->sect_info.type == H5HF_FSPACE_SECT_FIRST_ROW);
 
@@ -1802,8 +1802,8 @@ H5HF_sect_row_merge(H5FS_section_info_t *_sect1, H5FS_section_info_t *_sect2,
     } /* end if */
     else {
         /* Check to see if we should revive first section */
-        if(sect1->sect_info.state != H5FS_SECT_LIVE)
-            if(H5HF_sect_row_revive(hdr, dxpl_id, sect1) < 0)
+        if((*sect1)->sect_info.state != H5FS_SECT_LIVE)
+            if(H5HF_sect_row_revive(hdr, dxpl_id, (*sect1)) < 0)
                 HGOTO_ERROR(H5E_HEAP, H5E_CANTINIT, FAIL, "can't revive single free section")
 
         /* Check to see if we should revive second section */
@@ -1812,7 +1812,7 @@ H5HF_sect_row_merge(H5FS_section_info_t *_sect1, H5FS_section_info_t *_sect2,
                 HGOTO_ERROR(H5E_HEAP, H5E_CANTINIT, FAIL, "can't revive single free section")
 
         /* Merge rows' underlying indirect sections together */
-        if(H5HF_sect_indirect_merge_row(hdr, dxpl_id, sect1, sect2) < 0)
+        if(H5HF_sect_indirect_merge_row(hdr, dxpl_id, (*sect1), sect2) < 0)
             HGOTO_ERROR(H5E_HEAP, H5E_CANTMERGE, FAIL, "can't merge underlying indirect sections")
     } /* end else */
 
diff --git a/src/H5MF.c b/src/H5MF.c
index 23f128f..358e326 100644
--- a/src/H5MF.c
+++ b/src/H5MF.c
@@ -29,6 +29,7 @@
 /****************/
 
 #define H5F_FRIEND		/*suppress error about including H5Fpkg	  */
+#define H5FS_FRIEND		/*suppress error about including H5Fpkg	  */
 #include "H5MFmodule.h"         /* This source code file is part of the H5MF module */
 
 
@@ -38,6 +39,7 @@
 #include "H5private.h"		/* Generic Functions			*/
 #include "H5Eprivate.h"		/* Error handling		  	*/
 #include "H5Fpkg.h"             /* File access				*/
+#include "H5FSpkg.h"            /* File access              */
 #include "H5Iprivate.h"		/* IDs			  		*/
 #include "H5MFpkg.h"		/* File memory management		*/
 #include "H5VMprivate.h"	/* Vectors and arrays 			*/
@@ -50,11 +52,6 @@
 #define H5MF_FSPACE_SHRINK      80              /* Percent of "normal" size to shrink serialized free space size */
 #define H5MF_FSPACE_EXPAND      120             /* Percent of "normal" size to expand serialized free space size */
 
-/* Map an allocation request type to a free list */
-#define H5MF_ALLOC_TO_FS_TYPE(F, T)      ((H5FD_MEM_DEFAULT == (F)->shared->fs_type_map[T]) \
-    ? (T) : (F)->shared->fs_type_map[T])
-
-
 /******************/
 /* Local Typedefs */
 /******************/
@@ -84,11 +81,24 @@ typedef struct {
 /********************/
 
 /* Allocator routines */
-static herr_t H5MF_alloc_create(H5F_t *f, hid_t dxpl_id, H5FD_mem_t type);
-static herr_t H5MF__alloc_close(H5F_t *f, hid_t dxpl_id, H5FD_mem_t type);
-static herr_t H5MF__close_delete(H5F_t *f, hid_t dxpl_id, H5P_genplist_t **dxpl);
+static haddr_t H5MF__alloc_pagefs(H5F_t *f, H5FD_mem_t alloc_type, hid_t dxpl_id, hsize_t size);
+
+/* "File closing" routines */
+static herr_t H5MF__close_aggrfs(H5F_t *f, hid_t dxpl_id);
+static herr_t H5MF__close_pagefs(H5F_t *f, hid_t dxpl_id);
 static herr_t H5MF__close_shrink_eoa(H5F_t *f, hid_t dxpl_id);
 
+/* General routines */
+static herr_t H5MF__get_free_sects(H5F_t *f, hid_t dxpl_id, H5FS_t *fspace, H5MF_sect_iter_ud_t *sect_udata, size_t *nums);
+static hbool_t H5MF__fsm_type_is_self_referential(H5F_t *f, H5F_mem_page_t fsm_type);
+static hbool_t H5MF__fsm_is_self_referential(H5F_t *f, H5FS_t *fspace);
+
+/* Free-space type manager routines */
+static herr_t H5MF__create_fstype(H5F_t *f, hid_t dxpl_id, H5F_mem_page_t type);
+static herr_t H5MF__close_fstype(H5F_t *f, hid_t dxpl_id, H5F_mem_page_t type);
+static herr_t H5MF__delete_fstype(H5F_t *f, hid_t dxpl_id, H5F_mem_page_t type);
+static herr_t H5MF__close_delete_fstype(H5F_t *f, hid_t dxpl_id, H5F_mem_page_t type);
+
 
 /*********************/
 /* Package Variables */
@@ -223,10 +233,54 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5MF__alloc_open
+ * Function:    H5MF_alloc_to_fs_type
+ *
+ * Purpose:     Map "alloc_type" to the free-space manager type
+ *
+ * Return:      Success:        non-negative
+ *              Failure:        negative
+ *
+ * Programmer: Vailin Choi; Nov 2016
+ *
+ *-------------------------------------------------------------------------
+ */
+void
+H5MF_alloc_to_fs_type(H5F_t *f, H5FD_mem_t alloc_type, hsize_t size, H5F_mem_page_t *fs_type)
+{
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    HDassert(f);
+    HDassert(fs_type);
+
+    if(H5F_PAGED_AGGR(f)) { /* paged aggregation */
+        if(size >= f->shared->fs_page_size) {
+            if(H5F_HAS_FEATURE(f, H5FD_FEAT_PAGED_AGGR)) { /* multi or split driver */
+                /* For non-contiguous address space, map to large size free-space manager for each alloc_type */
+                if(H5FD_MEM_DEFAULT == f->shared->fs_type_map[alloc_type]) 
+                    *fs_type = (H5F_mem_page_t) (alloc_type + (H5FD_MEM_NTYPES - 1));
+                else
+                    *fs_type = (H5F_mem_page_t) (f->shared->fs_type_map[alloc_type] + (H5FD_MEM_NTYPES - 1));
+            } /* end if */
+            else
+                /* For contiguous address space, map to generic large size free-space manager */
+                *fs_type = H5F_MEM_PAGE_GENERIC; /* H5F_MEM_PAGE_SUPER */
+        } /* end if */
+        else
+            *fs_type = (H5F_mem_page_t)H5MF_ALLOC_TO_FS_AGGR_TYPE(f, alloc_type);
+    } /* end if */
+    else /* non-paged aggregation */
+        *fs_type = (H5F_mem_page_t)H5MF_ALLOC_TO_FS_AGGR_TYPE(f, alloc_type);
+
+    FUNC_LEAVE_NOAPI_VOID
+} /* end H5MF_alloc_to_fs_type() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5MF_open_fstype
  *
  * Purpose:	Open an existing free space manager of TYPE for file by
- *		creating a free-space structure
+ *          creating a free-space structure.
+ *          Note that TYPE can be H5F_mem_page_t or H5FD_mem_t enum types.
  *
  * Return:	Success:	non-negative
  *		Failure:	negative
@@ -238,31 +292,48 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5MF__alloc_open(H5F_t *f, hid_t dxpl_id, H5FD_mem_t type)
+H5MF_open_fstype(H5F_t *f, hid_t dxpl_id, H5F_mem_page_t type)
 {
     const H5FS_section_class_t *classes[] = { /* Free space section classes implemented for file */
-        H5MF_FSPACE_SECT_CLS_SIMPLE};
-    H5P_genplist_t *dxpl = NULL;        /* DXPL for setting ring */
-    H5AC_ring_t fsm_ring;               /* Free space manager ring */
-    H5AC_ring_t orig_ring = H5AC_RING_INV;      /* Original ring value */
-    hbool_t reset_ring = FALSE;         /* Whether the ring was set */
-    herr_t ret_value = SUCCEED;         /* Return value */
+        H5MF_FSPACE_SECT_CLS_SIMPLE,
+        H5MF_FSPACE_SECT_CLS_SMALL,
+        H5MF_FSPACE_SECT_CLS_LARGE };
+    hsize_t alignment;                      /* Alignment to use */
+    hsize_t threshold;                      /* Threshold to use */
+    H5P_genplist_t *dxpl = NULL;            /* DXPL for setting ring */
+    H5AC_ring_t orig_ring = H5AC_RING_INV;  /* Original ring value */
+    H5AC_ring_t fsm_ring = H5AC_RING_INV;   /* ring of fsm */
+    hbool_t reset_ring = FALSE;             /* Whether the ring was set */
+    herr_t ret_value = SUCCEED;             /* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT_TAG(dxpl_id, H5AC__FREESPACE_TAG, FAIL)
+    FUNC_ENTER_NOAPI_TAG(dxpl_id, H5AC__FREESPACE_TAG, FAIL)
 
     /*
      * Check arguments.
      */
     HDassert(f);
+    if(H5F_PAGED_AGGR(f))
+        HDassert(type < H5F_MEM_PAGE_NTYPES);
+    else {
+        HDassert((H5FD_mem_t)type < H5FD_MEM_NTYPES);
+        HDassert((H5FD_mem_t)type != H5FD_MEM_NOLIST);
+    } /* end else */
     HDassert(f->shared);
-    HDassert(type != H5FD_MEM_NOLIST);
     HDassert(H5F_addr_defined(f->shared->fs_addr[type]));
     HDassert(f->shared->fs_state[type] == H5F_FS_STATE_CLOSED);
-    HDassert(type == H5MF_ALLOC_TO_FS_TYPE(f, type));
+
+    /* Set up the aligment and threshold to use depending on the manager type */
+    if(H5F_PAGED_AGGR(f)) {
+        alignment = (type == H5F_MEM_PAGE_GENERIC) ? f->shared->fs_page_size : (hsize_t)H5F_ALIGN_DEF;
+        threshold = H5F_ALIGN_THRHD_DEF;
+    } /* end if */
+    else {
+        alignment = f->shared->alignment;
+        threshold = f->shared->threshold;
+    } /* end else */
 
     /* Set the ring type in the DXPL */
-    if((type == H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_HDR))
-            || (type == H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_SINFO)))
+    if(H5MF__fsm_type_is_self_referential(f, type))
         fsm_ring = H5AC_RING_MDFSM;
     else
         fsm_ring = H5AC_RING_RDFSM;
@@ -272,7 +343,7 @@ H5MF__alloc_open(H5F_t *f, hid_t dxpl_id, H5FD_mem_t type)
 
     /* Open an existing free space structure for the file */
     if(NULL == (f->shared->fs_man[type] = H5FS_open(f, dxpl_id, f->shared->fs_addr[type],
-	    NELMTS(classes), classes, f, f->shared->alignment, f->shared->threshold)))
+	    NELMTS(classes), classes, f, alignment, threshold)))
         HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't initialize free space info")
 
     /* Set the state for the free space manager to "open", if it is now */
@@ -286,14 +357,15 @@ done:
             HDONE_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set property value")
 
     FUNC_LEAVE_NOAPI_TAG(ret_value, FAIL)
-} /* end H5MF__alloc_open() */
+} /* end H5MF_open_fstype() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5MF_alloc_create
+ * Function:	H5MF__create_fstype
  *
  * Purpose:	Create free space manager of TYPE for the file by creating
- *		a free-space structure
+ *          a free-space structure
+ *          Note that TYPE can be H5F_mem_page_t or H5FD_mem_t enum types.
  *
  * Return:	Success:	non-negative
  *		Failure:	negative
@@ -305,21 +377,34 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5MF_alloc_create(H5F_t *f, hid_t dxpl_id, H5FD_mem_t type)
+H5MF__create_fstype(H5F_t *f, hid_t dxpl_id, H5F_mem_page_t type)
 {
     const H5FS_section_class_t *classes[] = { /* Free space section classes implemented for file */
-        H5MF_FSPACE_SECT_CLS_SIMPLE};
-    herr_t ret_value = SUCCEED;         /* Return value */
-    H5FS_create_t fs_create; 		/* Free space creation parameters */
+        H5MF_FSPACE_SECT_CLS_SIMPLE,
+        H5MF_FSPACE_SECT_CLS_SMALL,
+        H5MF_FSPACE_SECT_CLS_LARGE };
+    H5FS_create_t fs_create;    /* Free space creation parameters */
+    hsize_t alignment;          /* Alignment to use */
+    hsize_t threshold;			/* Threshold to use */
+    H5P_genplist_t *dxpl = NULL;            /* DXPL for setting ring */
+    H5AC_ring_t orig_ring = H5AC_RING_INV;  /* Original ring value */
+    H5AC_ring_t fsm_ring = H5AC_RING_INV;   /* ring of fsm */
+    hbool_t reset_ring = FALSE;             /* Whether the ring was set */
+    herr_t ret_value = SUCCEED;             /* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT_TAG(dxpl_id, H5AC__FREESPACE_TAG, FAIL)
+    FUNC_ENTER_STATIC_TAG(dxpl_id, H5AC__FREESPACE_TAG, FAIL)
 
     /*
      * Check arguments.
      */
     HDassert(f);
+    if(H5F_PAGED_AGGR(f))
+        HDassert(type < H5F_MEM_PAGE_NTYPES);
+    else {
+        HDassert((H5FD_mem_t)type < H5FD_MEM_NTYPES);
+        HDassert((H5FD_mem_t)type != H5FD_MEM_NOLIST);
+    } /* end else */
     HDassert(f->shared);
-    HDassert(type != H5FD_MEM_NOLIST);
     HDassert(!H5F_addr_defined(f->shared->fs_addr[type]));
     HDassert(f->shared->fs_state[type] == H5F_FS_STATE_CLOSED);
 
@@ -330,24 +415,48 @@ H5MF_alloc_create(H5F_t *f, hid_t dxpl_id, H5FD_mem_t type)
     fs_create.max_sect_addr = 1 + H5VM_log2_gen((uint64_t)f->shared->maxaddr);
     fs_create.max_sect_size = f->shared->maxaddr;
 
-    if(NULL == (f->shared->fs_man[type] = H5FS_create(f, dxpl_id, NULL,
-	    &fs_create, NELMTS(classes), classes, f, f->shared->alignment, f->shared->threshold)))
-	HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't initialize free space info")
+    /* Set up alignment and threshold to use depending on TYPE */
+    if(H5F_PAGED_AGGR(f)) {
+        alignment = (type == H5F_MEM_PAGE_GENERIC) ? f->shared->fs_page_size : (hsize_t)H5F_ALIGN_DEF;
+        threshold = H5F_ALIGN_THRHD_DEF;
+    } /* end if */
+    else {
+        alignment = f->shared->alignment;
+        threshold = f->shared->threshold;
+    } /* end else */
 
+    /* Set the ring type in the DXPL */
+    if(H5MF__fsm_type_is_self_referential(f, type))
+        fsm_ring = H5AC_RING_MDFSM;
+    else
+        fsm_ring = H5AC_RING_RDFSM;
+    if(H5AC_set_ring(dxpl_id, fsm_ring, &dxpl, &orig_ring) < 0)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value")
+    reset_ring = TRUE;
+
+    if(NULL == (f->shared->fs_man[type] = H5FS_create(f, dxpl_id, NULL,
+	    &fs_create, NELMTS(classes), classes, f, alignment, threshold)))
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't initialize free space info")
 
     /* Set the state for the free space manager to "open", if it is now */
     if(f->shared->fs_man[type])
         f->shared->fs_state[type] = H5F_FS_STATE_OPEN;
 
 done:
+    /* Reset the ring in the DXPL */
+    if(reset_ring)
+        if(H5AC_reset_ring(dxpl, orig_ring) < 0)
+            HDONE_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set property value")
+
     FUNC_LEAVE_NOAPI_TAG(ret_value, FAIL)
-} /* end H5MF_alloc_create() */
+} /* end H5MF__create_fstype() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5MF__alloc_start
+ * Function:	H5MF_start_fstype
  *
- * Purpose:	Open or create a free space manager of a given type
+ * Purpose:	Open or create a free space manager of a given TYPE.
+ *          Note that TYPE can be H5F_mem_page_t or H5FD_mem_t enum types.
  *
  * Return:	Success:	non-negative
  *		Failure:	negative
@@ -359,40 +468,123 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5MF__alloc_start(H5F_t *f, hid_t dxpl_id, H5FD_mem_t type)
+H5MF_start_fstype(H5F_t *f, hid_t dxpl_id, H5F_mem_page_t type)
 {
     herr_t ret_value = SUCCEED;         /* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT
+    FUNC_ENTER_NOAPI_TAG(dxpl_id, H5AC__FREESPACE_TAG, FAIL)
 
     /*
      * Check arguments.
      */
     HDassert(f);
     HDassert(f->shared);
-    HDassert(type != H5FD_MEM_NOLIST);
+    if(H5F_PAGED_AGGR(f))
+        HDassert(type < H5F_MEM_PAGE_NTYPES);
+    else {
+        HDassert((H5FD_mem_t)type < H5FD_MEM_NTYPES);
+        HDassert((H5FD_mem_t)type != H5FD_MEM_NOLIST);
+    } /* end else */
 
     /* Check if the free space manager exists already */
     if(H5F_addr_defined(f->shared->fs_addr[type])) {
         /* Open existing free space manager */
-        if(H5MF__alloc_open(f, dxpl_id, type) < 0)
+        if(H5MF_open_fstype(f, dxpl_id, type) < 0)
             HGOTO_ERROR(H5E_RESOURCE, H5E_CANTOPENOBJ, FAIL, "can't initialize file free space")
     } /* end if */
     else {
         /* Create new free space manager */
-        if(H5MF_alloc_create(f, dxpl_id, type) < 0)
+        if(H5MF__create_fstype(f, dxpl_id, type) < 0)
             HGOTO_ERROR(H5E_RESOURCE, H5E_CANTCREATE, FAIL, "can't initialize file free space")
     } /* end else */
 
 done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5MF__alloc_start() */
+    FUNC_LEAVE_NOAPI_TAG(ret_value, FAIL)
+} /* end H5MF_start_fstype() */
 
 
 /*-------------------------------------------------------------------------
- * Function:    H5MF__alloc_close
+ * Function:    H5MF__delete_fstype
  *
- * Purpose:     Close an existing free space manager of TYPE for file
+ * Purpose:     Delete the free-space manager as specified by TYPE.
+ *              Note that TYPE can be H5F_mem_page_t or H5FD_mem_t enum types.
+ *
+ * Return:      Success:        non-negative
+ *              Failure:        negative
+ *
+ * Programmer: 	Vailin Choi; April 2013
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5MF__delete_fstype(H5F_t *f, hid_t dxpl_id, H5F_mem_page_t type)
+{
+    H5P_genplist_t *dxpl = NULL;        /* DXPL for setting ring */
+    H5AC_ring_t orig_ring = H5AC_RING_INV;      /* Original ring value */
+    H5AC_ring_t fsm_ring = H5AC_RING_INV;       /* ring of fsm */
+    hbool_t reset_ring = FALSE;         /* Whether the ring was set */
+    haddr_t tmp_fs_addr;       	        /* Temporary holder for free space manager address */
+    herr_t ret_value = SUCCEED;	        /* Return value */
+
+    FUNC_ENTER_STATIC_TAG(dxpl_id, H5AC__FREESPACE_TAG, FAIL)
+
+    /* check args */
+    HDassert(f);
+    if(H5F_PAGED_AGGR(f))
+        HDassert(type < H5F_MEM_PAGE_NTYPES);
+    else
+        HDassert((H5FD_mem_t)type < H5FD_MEM_NTYPES);
+    HDassert(H5F_addr_defined(f->shared->fs_addr[type]));
+
+    /* Put address into temporary variable and reset it */
+    /* (Avoids loopback in file space freeing routine) */
+    tmp_fs_addr = f->shared->fs_addr[type];
+    f->shared->fs_addr[type] = HADDR_UNDEF;
+
+    /* Shift to "deleting" state, to make certain we don't track any
+     *  file space freed as a result of deleting the free space manager.
+     */
+    f->shared->fs_state[type] = H5F_FS_STATE_DELETING;
+
+    /* Set the ring type in the DXPL */
+    if(H5MF__fsm_type_is_self_referential(f, type))
+        fsm_ring = H5AC_RING_MDFSM;
+    else
+        fsm_ring = H5AC_RING_RDFSM;
+    if(H5AC_set_ring(dxpl_id, fsm_ring, &dxpl, &orig_ring) < 0)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value")
+    reset_ring = TRUE;
+
+#ifdef H5MF_ALLOC_DEBUG_MORE
+HDfprintf(stderr, "%s: Before deleting free space manager\n", FUNC);
+#endif /* H5MF_ALLOC_DEBUG_MORE */
+
+    /* Delete free space manager for this type */
+    if(H5FS_delete(f, dxpl_id, tmp_fs_addr) < 0)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, FAIL, "can't delete free space manager")
+
+    /* Shift [back] to closed state */
+    HDassert(f->shared->fs_state[type] == H5F_FS_STATE_DELETING);
+    f->shared->fs_state[type] = H5F_FS_STATE_CLOSED;
+
+    /* Sanity check that the free space manager for this type wasn't started up again */
+    HDassert(!H5F_addr_defined(f->shared->fs_addr[type]));
+
+done:
+    /* Reset the ring in the DXPL */
+    if(reset_ring)
+        if(H5AC_reset_ring(dxpl, orig_ring) < 0)
+            HDONE_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set property value")
+
+    FUNC_LEAVE_NOAPI_TAG(ret_value, FAIL)
+} /* end H5MF__delete_fstype() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5MF__close_fstype
+ *
+ * Purpose:     Close the free space manager of TYPE for file
+ *              Note that TYPE can be H5F_mem_page_t or H5FD_mem_t enum types.
  *
  * Return:      Success:        non-negative
  *              Failure:        negative
@@ -402,7 +594,7 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5MF__alloc_close(H5F_t *f, hid_t dxpl_id, H5FD_mem_t type)
+H5MF__close_fstype(H5F_t *f, hid_t dxpl_id, H5F_mem_page_t type)
 {
     herr_t ret_value = SUCCEED;         /* Return value */
 
@@ -412,11 +604,18 @@ H5MF__alloc_close(H5F_t *f, hid_t dxpl_id, H5FD_mem_t type)
      * Check arguments.
      */
     HDassert(f);
+    if(H5F_PAGED_AGGR(f))
+        HDassert(type < H5F_MEM_PAGE_NTYPES);
+    else
+        HDassert((H5FD_mem_t)type < H5FD_MEM_NTYPES);
     HDassert(f->shared);
-    HDassert(type != H5FD_MEM_NOLIST);
     HDassert(f->shared->fs_man[type]);
     HDassert(f->shared->fs_state[type] != H5F_FS_STATE_CLOSED);
 
+#ifdef H5MF_ALLOC_DEBUG_MORE
+HDfprintf(stderr, "%s: Before closing free space manager\n", FUNC);
+#endif /* H5MF_ALLOC_DEBUG_MORE */
+
     /* Close an existing free space structure for the file */
     if(H5FS_close(f, dxpl_id, f->shared->fs_man[type]) < 0)
         HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't release free space info")
@@ -425,7 +624,158 @@ H5MF__alloc_close(H5F_t *f, hid_t dxpl_id, H5FD_mem_t type)
 
 done:
     FUNC_LEAVE_NOAPI_TAG(ret_value, FAIL)
-} /* end H5MF__alloc_close() */
+} /* end H5MF__close_fstype() */
+
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5MF_add_sect
+ *
+ * Purpose:	    To add a section to the specified free-space manager.
+ *
+ * Return:      Success:        non-negative
+ *              Failure:        negative
+ *
+ * Programmer:  Vailin Choi; April 2013
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5MF_add_sect(H5F_t *f, H5FD_mem_t alloc_type, hid_t dxpl_id, H5FS_t *fspace, H5MF_free_section_t *node)
+{
+    H5P_genplist_t *dxpl = NULL;            /* DXPL for setting ring */
+    H5AC_ring_t orig_ring = H5AC_RING_INV;  /* Original ring value */
+    H5AC_ring_t fsm_ring = H5AC_RING_INV;   /* ring of fsm */
+    H5MF_sect_ud_t udata;		            /* User data for callback */
+    H5F_mem_page_t  fs_type;                /* Free space type (mapped from allocation type) */
+
+    herr_t ret_value = SUCCEED; 	        /* Return value */
+
+    FUNC_ENTER_NOAPI_TAG(dxpl_id, H5AC__FREESPACE_TAG, FAIL)
+
+    HDassert(f);
+    HDassert(fspace);
+    HDassert(node);
+
+    H5MF_alloc_to_fs_type(f, alloc_type, node->sect_info.size, &fs_type);
+
+    /* Construct user data for callbacks */
+    udata.f = f;
+    udata.dxpl_id = dxpl_id;
+    udata.alloc_type = alloc_type;
+    udata.allow_sect_absorb = TRUE;
+    udata.allow_eoa_shrink_only = FALSE;
+
+    /* Set the ring type in the DXPL */
+    if(H5MF__fsm_is_self_referential(f, fspace))
+        fsm_ring = H5AC_RING_MDFSM;
+    else
+        fsm_ring = H5AC_RING_RDFSM;
+    if(H5AC_set_ring(dxpl_id, fsm_ring, &dxpl, &orig_ring) < 0)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value")
+
+#ifdef H5MF_ALLOC_DEBUG_MORE
+HDfprintf(stderr, "%s: adding node, node->sect_info.addr = %a, node->sect_info.size = %Hu\n", FUNC, node->sect_info.addr, node->sect_info.size);
+#endif /* H5MF_ALLOC_DEBUG_MORE */
+    /* Add the section */
+    if(H5FS_sect_add(f, dxpl_id, fspace, (H5FS_section_info_t *)node, H5FS_ADD_RETURNED_SPACE, &udata) < 0)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINSERT, FAIL, "can't re-add section to file free space")
+
+done:
+    /* Reset the ring in the DXPL */
+    if(H5AC_reset_ring(dxpl, orig_ring) < 0)
+        HDONE_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set property value")
+    FUNC_LEAVE_NOAPI_TAG(ret_value, FAIL)
+} /* end H5MF_add_sect() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5MF_find_sect
+ *
+ * Purpose:	To find a section from the specified free-space manager to fulfill the request.
+ *		    If found, re-add the left-over space back to the manager.
+ *
+ * Return:	TRUE if a section is found to fulfill the request
+ *		    FALSE if not
+ *
+ * Programmer:  Vailin Choi; April 2013
+ *
+ *-------------------------------------------------------------------------
+ */
+htri_t
+H5MF_find_sect(H5F_t *f, H5FD_mem_t alloc_type, hid_t dxpl_id, hsize_t size, H5FS_t *fspace, haddr_t *addr)
+{
+    H5P_genplist_t *dxpl = NULL;            /* DXPL for setting ring */
+    H5AC_ring_t orig_ring = H5AC_RING_INV;  /* Original ring value */
+    H5AC_ring_t fsm_ring = H5AC_RING_INV;   /* ring of fsm */
+    H5MF_free_section_t *node;              /* Free space section pointer */
+    hbool_t reset_ring = FALSE;             /* Whether the ring was set */
+    htri_t ret_value = FAIL;      	    /* Whether an existing free list node was found */
+
+    FUNC_ENTER_NOAPI_TAG(dxpl_id, H5AC__FREESPACE_TAG, FAIL)
+
+    HDassert(f);
+    HDassert(fspace);
+
+    /* Set the ring type in the DXPL */
+    if(H5MF__fsm_is_self_referential(f, fspace))
+        fsm_ring = H5AC_RING_MDFSM;
+    else
+        fsm_ring = H5AC_RING_RDFSM;
+    if(H5AC_set_ring(dxpl_id, fsm_ring, &dxpl, &orig_ring) < 0)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value")
+    reset_ring = TRUE;
+
+    /* Try to get a section from the free space manager */
+    if((ret_value = H5FS_sect_find(f, dxpl_id, fspace, size, (H5FS_section_info_t **)&node)) < 0)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, FAIL, "error locating free space in file")
+
+#ifdef H5MF_ALLOC_DEBUG_MORE
+HDfprintf(stderr, "%s: section found = %t\n", FUNC, ret_value);
+#endif /* H5MF_ALLOC_DEBUG_MORE */
+
+    /* Check for actually finding section */
+    if(ret_value) {
+        /* Sanity check */
+        HDassert(node);
+
+        /* Retrieve return value */
+        if(addr)
+            *addr = node->sect_info.addr;
+
+        /* Check for eliminating the section */
+        if(node->sect_info.size == size) {
+#ifdef H5MF_ALLOC_DEBUG_MORE
+HDfprintf(stderr, "%s: freeing node\n", FUNC);
+#endif /* H5MF_ALLOC_DEBUG_MORE */
+
+            /* Free section node */
+            if(H5MF_sect_free((H5FS_section_info_t *)node) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't free simple section node")
+        } /* end if */
+        else {
+            /* Adjust information for section */
+            node->sect_info.addr += size;
+            node->sect_info.size -= size;
+
+#ifdef H5MF_ALLOC_DEBUG_MORE
+HDfprintf(stderr, "%s: re-adding node, node->sect_info.size = %Hu\n", FUNC, node->sect_info.size);
+#endif /* H5MF_ALLOC_DEBUG_MORE */
+
+            /* Re-add the section to the free-space manager */
+            if(H5MF_add_sect(f, alloc_type, dxpl_id, fspace, node) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINSERT, FAIL, "can't re-add section to file free space")
+        } /* end else */
+    } /* end if */
+
+done:
+    /* Reset the ring in the DXPL */
+    if(reset_ring)
+        if(H5AC_reset_ring(dxpl, orig_ring) < 0)
+            HDONE_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set property value")
+
+    FUNC_LEAVE_NOAPI_TAG(ret_value, FAIL)
+} /* end H5MF_find_sect() */
 
 
 /*-------------------------------------------------------------------------
@@ -451,7 +801,7 @@ H5MF_alloc(H5F_t *f, H5FD_mem_t alloc_type, hid_t dxpl_id, hsize_t size)
     H5P_genplist_t *dxpl = NULL;        /* DXPL for setting ring */
     H5AC_ring_t fsm_ring = H5AC_RING_INV;       /* free space manager ring */
     H5AC_ring_t orig_ring = H5AC_RING_INV;      /* Original ring value */
-    H5FD_mem_t  fs_type;                /* Free space type (mapped from allocation type) */
+    H5F_mem_page_t  fs_type;            /* Free space type (mapped from allocation type) */
     hbool_t reset_ring = FALSE;         /* Whether the ring was set */
     haddr_t ret_value = HADDR_UNDEF;    /* Return value */
 
@@ -466,12 +816,20 @@ HDfprintf(stderr, "%s: alloc_type = %u, size = %Hu\n", FUNC, (unsigned)alloc_typ
     HDassert(f->shared->lf);
     HDassert(size > 0);
 
-    /* Get free space type from allocation type */
-    fs_type = H5MF_ALLOC_TO_FS_TYPE(f, alloc_type);
+    if(f->shared->first_alloc_dealloc) {
+        HDassert(! H5AC_cache_image_pending(f));
+        if(H5MF_tidy_self_referential_fsm_hack(f, dxpl_id) < 0)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, HADDR_UNDEF, "tidy of self referential fsm hack failed")
+    } /* end if */
+
+    H5MF_alloc_to_fs_type(f, alloc_type, size, &fs_type);
+
+#ifdef H5MF_ALLOC_DEBUG_MORE
+HDfprintf(stderr, "%s: Check 1.0\n", FUNC);
+#endif /* H5MF_ALLOC_DEBUG_MORE */
 
     /* Set the ring type in the DXPL */
-    if((fs_type == H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_HDR))
-            || (fs_type == H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_SINFO)))
+    if(H5MF__fsm_type_is_self_referential(f, fs_type))
         fsm_ring = H5AC_RING_MDFSM;
     else
         fsm_ring = H5AC_RING_RDFSM;
@@ -481,74 +839,46 @@ HDfprintf(stderr, "%s: alloc_type = %u, size = %Hu\n", FUNC, (unsigned)alloc_typ
 
     /* Check if we are using the free space manager for this file */
     if(H5F_HAVE_FREE_SPACE_MANAGER(f)) {
+        /* We are about to change the contents of the free space manager --
+         * notify metadata cache that the associated fsm ring is
+         * unsettled
+         */
+        if(H5AC_unsettle_ring(f, fsm_ring) < 0)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_SYSTEM, HADDR_UNDEF, "attempt to notify cache that ring is unsettled failed")
+
         /* Check if the free space manager for the file has been initialized */
-        if(!f->shared->fs_man[fs_type] && H5F_addr_defined(f->shared->fs_addr[fs_type]))
-            if(H5MF__alloc_open(f, dxpl_id, fs_type) < 0)
+        if(!f->shared->fs_man[fs_type] && H5F_addr_defined(f->shared->fs_addr[fs_type])) {
+            /* Open the free-space manager */
+            if(H5MF_open_fstype(f, dxpl_id, fs_type) < 0)
                 HGOTO_ERROR(H5E_RESOURCE, H5E_CANTOPENOBJ, HADDR_UNDEF, "can't initialize file free space")
+            HDassert(f->shared->fs_man[fs_type]);
+        } /* end if */
 
         /* Search for large enough space in the free space manager */
-        if(f->shared->fs_man[fs_type]) {
-            H5MF_free_section_t *node;      /* Free space section pointer */
-            htri_t node_found = FALSE;      /* Whether an existing free list node was found */
-
-            /* Try to get a section from the free space manager */
-            if((node_found = H5FS_sect_find(f, dxpl_id, f->shared->fs_man[fs_type], size, (H5FS_section_info_t **)&node)) < 0)
-                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, HADDR_UNDEF, "error locating free space in file")
-#ifdef H5MF_ALLOC_DEBUG_MORE
-HDfprintf(stderr, "%s: Check 1.5, node_found = %t\n", FUNC, node_found);
-#endif /* H5MF_ALLOC_DEBUG_MORE */
-
-            /* Check for actually finding section */
-            if(node_found) {
-                /* Sanity check */
-                HDassert(node);
-
-                /* Retrieve return value */
-                ret_value = node->sect_info.addr;
-
-                /* Check for eliminating the section */
-                if(node->sect_info.size == size) {
-#ifdef H5MF_ALLOC_DEBUG_MORE
-HDfprintf(stderr, "%s: Check 1.6, freeing node\n", FUNC);
-#endif /* H5MF_ALLOC_DEBUG_MORE */
-                    /* Free section node */
-                    if(H5MF_sect_simple_free((H5FS_section_info_t *)node) < 0)
-                        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, HADDR_UNDEF, "can't free simple section node")
-                } /* end if */
-                else {
-                    H5MF_sect_ud_t udata;               /* User data for callback */
-
-                    /* Adjust information for section */
-                    node->sect_info.addr += size;
-                    node->sect_info.size -= size;
-
-                    /* Construct user data for callbacks */
-                    udata.f = f;
-                    udata.dxpl_id = dxpl_id;
-                    udata.alloc_type = alloc_type;
-                    udata.allow_sect_absorb = TRUE;
-		    udata.allow_eoa_shrink_only = FALSE; 
+        if(f->shared->fs_man[fs_type])
+            if(H5MF_find_sect(f, alloc_type, dxpl_id, size, f->shared->fs_man[fs_type], &ret_value) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, HADDR_UNDEF, "error locating a node")
+    } /* end if */
 
+    /* If no space is found from the free-space manager, continue further action */
+    if(!H5F_addr_defined(ret_value)) {
 #ifdef H5MF_ALLOC_DEBUG_MORE
-HDfprintf(stderr, "%s: Check 1.7, re-adding node, node->sect_info.size = %Hu\n", FUNC, node->sect_info.size);
+HDfprintf(stderr, "%s: Check 2.0\n", FUNC);
 #endif /* H5MF_ALLOC_DEBUG_MORE */
-                    /* Re-insert section node into file's free space */
-                    if(H5FS_sect_add(f, dxpl_id, f->shared->fs_man[fs_type], (H5FS_section_info_t *)node, H5FS_ADD_RETURNED_SPACE, &udata) < 0)
-                        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINSERT, HADDR_UNDEF, "can't re-add section to file free space")
-                } /* end else */
-
-                /* Leave now */
-                HGOTO_DONE(ret_value)
-            } /* end if */
+        if(f->shared->fs_strategy == H5F_FSPACE_STRATEGY_PAGE) {
+            HDassert(f->shared->fs_page_size >= H5F_FILE_SPACE_PAGE_SIZE_MIN);
+            if(HADDR_UNDEF == (ret_value = H5MF__alloc_pagefs(f, alloc_type, dxpl_id, size)))
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, HADDR_UNDEF, "allocation failed from paged aggregation")
         } /* end if */
+        else { /* For non-paged aggregation, continue further action */
+            if(HADDR_UNDEF == (ret_value = H5MF_aggr_vfd_alloc(f, alloc_type, dxpl_id, size)))
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, HADDR_UNDEF, "allocation failed from aggr/vfd")
+        } /* end else */
+    } /* end if */
+    HDassert(H5F_addr_defined(ret_value));
 #ifdef H5MF_ALLOC_DEBUG_MORE
-HDfprintf(stderr, "%s: Check 2.0\n", FUNC);
+HDfprintf(stderr, "%s: Check 3.0\n", FUNC);
 #endif /* H5MF_ALLOC_DEBUG_MORE */
-    } /* end if */
-
-    /* Allocate from the metadata aggregator (or the VFD) */
-    if(HADDR_UNDEF == (ret_value = H5MF_aggr_vfd_alloc(f, alloc_type, dxpl_id, size)))
-	HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, HADDR_UNDEF, "allocation failed from aggr/vfd")
 
 done:
     /* Reset the ring in the DXPL */
@@ -568,6 +898,146 @@ H5MF_sects_dump(f, dxpl_id, stderr);
 
 
 /*-------------------------------------------------------------------------
+ * Function:    H5MF__alloc_pagefs
+ *
+ * Purpose:     Allocate space from either the large or small free-space manager.
+ *              For "large" request:
+ *                  Allocate request from VFD
+ *                  Determine mis-aligned fragment and return the fragment to the
+ *                  appropriate manager
+ *              For "small" request:
+ *                  Allocate a page from the large manager
+ *                  Determine whether space is available from a mis-aligned fragment
+ *                  being returned to the manager
+ *              Return left-over space to the manager after fulfilling request
+ *
+ * Return:      Success:        The file address of new chunk.
+ *              Failure:        HADDR_UNDEF
+ *
+ * Programmer:  Vailin Choi; Dec 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+static haddr_t
+H5MF__alloc_pagefs(H5F_t *f, H5FD_mem_t alloc_type, hid_t dxpl_id, hsize_t size)
+{
+    H5F_mem_page_t ptype;		        /* Free-space mananger type */
+    H5MF_free_section_t *node = NULL;  	/* Free space section pointer */
+    haddr_t ret_value = HADDR_UNDEF; 	/* Return value */
+
+    FUNC_ENTER_STATIC_TAG(dxpl_id, H5AC__FREESPACE_TAG, HADDR_UNDEF)
+
+#ifdef H5MF_ALLOC_DEBUG
+HDfprintf(stderr, "%s: alloc_type = %u, size = %Hu\n", FUNC, (unsigned)alloc_type, size);
+#endif /* H5MF_ALLOC_DEBUG */
+
+    H5MF_alloc_to_fs_type(f, alloc_type, size, &ptype);
+
+    switch(ptype) {
+	    case H5F_MEM_PAGE_GENERIC:  
+	    case H5F_MEM_PAGE_LARGE_BTREE:
+	    case H5F_MEM_PAGE_LARGE_DRAW:
+	    case H5F_MEM_PAGE_LARGE_GHEAP:
+	    case H5F_MEM_PAGE_LARGE_LHEAP:
+	    case H5F_MEM_PAGE_LARGE_OHDR:
+        {
+            haddr_t eoa;            /* EOA for the file */
+            hsize_t frag_size = 0;  /* Fragment size */
+
+            /* Get the EOA for the file */
+            if(HADDR_UNDEF == (eoa = H5F_get_eoa(f, alloc_type)))
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, HADDR_UNDEF, "Unable to get eoa")
+            HDassert(!(eoa % f->shared->fs_page_size));
+
+            H5MF_EOA_MISALIGN(f, (eoa+size), f->shared->fs_page_size, frag_size);
+
+            /* Allocate from VFD */
+            if(HADDR_UNDEF == (ret_value = H5F_alloc(f, dxpl_id, alloc_type, size + frag_size, NULL, NULL)))
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, HADDR_UNDEF, "can't allocate file space")
+
+            /* If there is a mis-aligned fragment at EOA */
+            if(frag_size) {
+
+                /* Start up the free-space manager */
+                if(!(f->shared->fs_man[ptype]))
+                    if(H5MF_start_fstype(f, dxpl_id, ptype) < 0)
+                        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, HADDR_UNDEF, "can't initialize file free space")
+
+                /* Create free space section for the fragment */
+                if(NULL == (node = H5MF_sect_new(H5MF_FSPACE_SECT_LARGE, ret_value + size, frag_size)))
+                    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, HADDR_UNDEF, "can't initialize free space section")
+
+                /* Add the fragment to the large free-space manager */
+                if(H5MF_add_sect(f, alloc_type, dxpl_id, f->shared->fs_man[ptype], node) < 0)
+                    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINSERT, HADDR_UNDEF, "can't re-add section to file free space")
+
+                node = NULL;
+            } /* end if */
+        }
+        break;
+
+        case H5F_MEM_PAGE_META: 
+        case H5F_MEM_PAGE_DRAW:
+        case H5F_MEM_PAGE_BTREE:
+        case H5F_MEM_PAGE_GHEAP:
+        case H5F_MEM_PAGE_LHEAP:
+        case H5F_MEM_PAGE_OHDR:
+        {
+            haddr_t new_page;		/* The address for the new file size page */
+
+            /* Allocate one file space page */
+            if(HADDR_UNDEF == (new_page = H5MF_alloc(f, alloc_type, dxpl_id, f->shared->fs_page_size)))
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, HADDR_UNDEF, "can't allocate file space")
+
+            /* Start up the free-space manager */
+            if(!(f->shared->fs_man[ptype]))
+                if(H5MF_start_fstype(f, dxpl_id, ptype) < 0)
+                    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, HADDR_UNDEF, "can't initialize file free space")
+            HDassert(f->shared->fs_man[ptype]);
+
+            if(NULL == (node = H5MF_sect_new(H5MF_FSPACE_SECT_SMALL, (new_page + size), (f->shared->fs_page_size - size))))
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, HADDR_UNDEF, "can't initialize free space section")
+
+            /* Add the remaining space in the page to the manager */
+            if(H5MF_add_sect(f, alloc_type, dxpl_id, f->shared->fs_man[ptype], node) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINSERT, HADDR_UNDEF, "can't re-add section to file free space")
+
+            node = NULL;
+
+            /* Insert the new page into the Page Buffer list of new pages so 
+               we don't read an empty page from disk */
+            if(f->shared->page_buf != NULL && H5PB_add_new_page(f, alloc_type, new_page) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINSERT, HADDR_UNDEF, "can't add new page to Page Buffer new page list")
+
+            ret_value = new_page;
+        } 
+        break;
+
+        case H5F_MEM_PAGE_NTYPES:
+        case H5F_MEM_PAGE_DEFAULT:
+        default:
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, HADDR_UNDEF, "can't allocate file space: unrecognized type")
+            break;
+    } /* end switch */
+
+done:
+#ifdef H5MF_ALLOC_DEBUG
+HDfprintf(stderr, "%s: Leaving: ret_value = %a, size = %Hu\n", FUNC, ret_value, size);
+#endif /* H5MF_ALLOC_DEBUG */
+#ifdef H5MF_ALLOC_DEBUG_DUMP
+H5MF_sects_dump(f, dxpl_id, stderr);
+#endif /* H5MF_ALLOC_DEBUG_DUMP */
+
+    /* Release section node, if allocated and not added to section list or merged */
+    if(node)
+        if(H5MF_sect_free((H5FS_section_info_t *)node) < 0)
+            HDONE_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, HADDR_UNDEF, "can't free section node")
+
+    FUNC_LEAVE_NOAPI_TAG(ret_value, HADDR_UNDEF)
+} /* end H5MF__alloc_pagefs() */
+
+
+/*-------------------------------------------------------------------------
  * Function:    H5MF_alloc_tmp
  *
  * Purpose:     Allocate temporary space in the file
@@ -645,14 +1115,14 @@ herr_t
 H5MF_xfree(H5F_t *f, H5FD_mem_t alloc_type, hid_t dxpl_id, haddr_t addr,
     hsize_t size)
 {
-    H5F_io_info_t fio_info;             /* I/O info for operation */
+    H5F_io_info2_t fio_info;            /* I/O info for operation */
+    H5F_mem_page_t  fs_type;            /* Free space type (mapped from allocation type) */
     H5MF_free_section_t *node = NULL;   /* Free space section pointer */
-    H5MF_sect_ud_t udata;               /* User data for callback */
+    unsigned ctype;			/* section class type */
     H5P_genplist_t *dxpl = NULL;        /* DXPL for setting ring */
-    H5AC_ring_t fsm_ring;               /* Free space manager ring */
-    H5AC_ring_t orig_ring = H5AC_RING_INV;      /* Original ring value */
+    H5AC_ring_t orig_ring = H5AC_RING_INV;  /* Original ring value */
+    H5AC_ring_t fsm_ring = H5AC_RING_INV;   /* Ring of fsm */
     hbool_t reset_ring = FALSE;         /* Whether the ring was set */
-    H5FD_mem_t fs_type;                 /* Free space type (mapped from allocation type) */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI_TAG(dxpl_id, H5AC__FREESPACE_TAG, FAIL)
@@ -666,19 +1136,16 @@ HDfprintf(stderr, "%s: Entering - alloc_type = %u, addr = %a, size = %Hu\n", FUN
         HGOTO_DONE(SUCCEED)
     HDassert(addr != 0);        /* Can't deallocate the superblock :-) */
 
-    /* Check for attempting to free space that's a 'temporary' file address */
-    if(H5F_addr_le(f->shared->tmp_addr, addr))
-        HGOTO_ERROR(H5E_RESOURCE, H5E_BADRANGE, FAIL, "attempting to free temporary file space")
+    if(f->shared->first_alloc_dealloc) {
+        HDassert(!H5AC_cache_image_pending(f));
+        if(H5MF_tidy_self_referential_fsm_hack(f, dxpl_id) < 0)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, FAIL, "tidy of self referential fsm hack failed")
+    } /* end if */
 
-    /* Get free space type from allocation type */
-    fs_type = H5MF_ALLOC_TO_FS_TYPE(f, alloc_type);
-#ifdef H5MF_ALLOC_DEBUG_MORE
-HDfprintf(stderr, "%s: fs_type = %u\n", FUNC, (unsigned)fs_type);
-#endif /* H5MF_ALLOC_DEBUG_MORE */
+    H5MF_alloc_to_fs_type(f, alloc_type, size, &fs_type);
 
     /* Set the ring type in the DXPL */
-    if((fs_type == H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_HDR))
-            || (fs_type == H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_SINFO)))
+    if(H5MF__fsm_type_is_self_referential(f, fs_type))
         fsm_ring = H5AC_RING_MDFSM;
     else
         fsm_ring = H5AC_RING_RDFSM;
@@ -686,10 +1153,33 @@ HDfprintf(stderr, "%s: fs_type = %u\n", FUNC, (unsigned)fs_type);
         HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value")
     reset_ring = TRUE;
 
+    /* we are about to change the contents of the free space manager --
+     * notify metadata cache that the associated fsm ring is
+     * unsettled
+     */
+    /* Only do so for strategies that use free-space managers */
+    if(H5F_HAVE_FREE_SPACE_MANAGER(f))
+        if(H5AC_unsettle_ring(f, fsm_ring) < 0)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_SYSTEM, FAIL, "attempt to notify cache that ring is unsettled failed")
+
+    /* Check for attempting to free space that's a 'temporary' file address */
+    if(H5F_addr_le(f->shared->tmp_addr, addr))
+        HGOTO_ERROR(H5E_RESOURCE, H5E_BADRANGE, FAIL, "attempting to free temporary file space")
+
     /* Set up I/O info for operation */
     fio_info.f = f;
-    if(NULL == (fio_info.dxpl = (H5P_genplist_t *)H5I_object(dxpl_id)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+    if(H5FD_MEM_DRAW == alloc_type) {
+        if(NULL == (fio_info.meta_dxpl = (H5P_genplist_t *)H5I_object(H5AC_ind_read_dxpl_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+        if(NULL == (fio_info.raw_dxpl = (H5P_genplist_t *)H5I_object(dxpl_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+    } /* end if */
+    else {
+        if(NULL == (fio_info.meta_dxpl = (H5P_genplist_t *)H5I_object(dxpl_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+        if(NULL == (fio_info.raw_dxpl = (H5P_genplist_t *)H5I_object(H5AC_rawdata_dxpl_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+    } /* end else */
 
     /* Check if the space to free intersects with the file's metadata accumulator */
     if(H5F__accum_free(&fio_info, alloc_type, addr, size) < 0)
@@ -702,7 +1192,7 @@ HDfprintf(stderr, "%s: fs_type = %u\n", FUNC, (unsigned)fs_type);
          *  space is at the end of the file
          */
 #ifdef H5MF_ALLOC_DEBUG_MORE
-HDfprintf(stderr, "%s: f->shared->fs_addr[%u] = %a\n", FUNC, (unsigned)fs_type, f->shared->fs_addr[fs_type]);
+HDfprintf(stderr, "%s: fs_addr = %a\n", FUNC, f->shared->fs_addr[fs_type]);
 #endif /* H5MF_ALLOC_DEBUG_MORE */
         if(!H5F_addr_defined(f->shared->fs_addr[fs_type])) {
             htri_t status;          /* "can absorb" status for section into */
@@ -726,8 +1216,8 @@ HDfprintf(stderr, "%s: dropping addr = %a, size = %Hu, on the floor!\n", FUNC, a
 
         /* If we are deleting the free space manager, leave now, to avoid
          *  [re-]starting it.
-	 * or if file space strategy type is not using a free space manager
-	 *   (H5F_FILE_SPACE_AGGR_VFD or H5F_FILE_SPACE_VFD), drop free space
+         * or if file space strategy type is not using a free space manager
+         *  (H5F_FSPACE_STRATEGY_AGGR or H5F_FSPACE_STRATEGY_NONE), drop free space
          *   section on the floor.
          *
          * Note: this drops the space to free on the floor...
@@ -745,38 +1235,42 @@ HDfprintf(stderr, "%s: dropping addr = %a, size = %Hu, on the floor!\n", FUNC, a
          *  space isn't at the end of the file, so start up (or create)
          *  the file space manager
          */
-        if(H5MF__alloc_start(f, dxpl_id, fs_type) < 0)
+        if(H5MF_start_fstype(f, dxpl_id, fs_type) < 0)
             HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't initialize file free space")
     } /* end if */
 
-    /* Create free space section for block */
-    if(NULL == (node = H5MF_sect_simple_new(addr, size)))
+    /* Create the free-space section for the freed section */
+    ctype = H5MF_SECT_CLASS_TYPE(f, size);
+    if(NULL == (node = H5MF_sect_new(ctype, addr, size)))
         HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't initialize free space section")
 
-    /* Construct user data for callbacks */
-    udata.f = f;
-    udata.dxpl_id = dxpl_id;
-    udata.alloc_type = alloc_type;
-    udata.allow_sect_absorb = TRUE;
-    udata.allow_eoa_shrink_only = FALSE; 
-
-    /* If size of section freed is larger than threshold, add it to the free space manager */
+    /* If size of the freed section is larger than threshold, add it to the free space manager */
     if(size >= f->shared->fs_threshold) {
 	HDassert(f->shared->fs_man[fs_type]);
 
 #ifdef H5MF_ALLOC_DEBUG_MORE
 HDfprintf(stderr, "%s: Before H5FS_sect_add()\n", FUNC);
 #endif /* H5MF_ALLOC_DEBUG_MORE */
+
         /* Add to the free space for the file */
-	if(H5FS_sect_add(f, dxpl_id, f->shared->fs_man[fs_type], (H5FS_section_info_t *)node, H5FS_ADD_RETURNED_SPACE, &udata) < 0)
-	    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINSERT, FAIL, "can't add section to file free space")
-	node = NULL;
+        if(H5MF_add_sect(f, alloc_type, dxpl_id, f->shared->fs_man[fs_type], node) < 0)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINSERT, FAIL, "can't add section to file free space")
+        node = NULL;
+
 #ifdef H5MF_ALLOC_DEBUG_MORE
 HDfprintf(stderr, "%s: After H5FS_sect_add()\n", FUNC);
 #endif /* H5MF_ALLOC_DEBUG_MORE */
     } /* end if */
     else {
         htri_t merged;          /* Whether node was merged */
+        H5MF_sect_ud_t udata; 	/* User data for callback */
+
+        /* Construct user data for callbacks */
+        udata.f = f;
+        udata.dxpl_id = dxpl_id;
+        udata.alloc_type = alloc_type;
+        udata.allow_sect_absorb = TRUE;
+        udata.allow_eoa_shrink_only = FALSE;
 
         /* Try to merge the section that is smaller than threshold */
 	if((merged = H5FS_sect_try_merge(f, dxpl_id, f->shared->fs_man[fs_type], (H5FS_section_info_t *)node, H5FS_ADD_RETURNED_SPACE, &udata)) < 0)
@@ -794,7 +1288,7 @@ done:
 
     /* Release section node, if allocated and not added to section list or merged */
     if(node)
-        if(H5MF_sect_simple_free((H5FS_section_info_t *)node) < 0)
+        if(H5MF_sect_free((H5FS_section_info_t *)node) < 0)
             HDONE_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't free simple section node")
 
 #ifdef H5MF_ALLOC_DEBUG
@@ -811,6 +1305,14 @@ H5MF_sects_dump(f, dxpl_id, stderr);
  * Function:	H5MF_try_extend
  *
  * Purpose:	Extend a block in the file if possible.
+ *          For non-paged aggregation:
+ *          --try to extend at EOA
+ *          --try to extend into the aggregators
+ *          --try to extend into a free-space section if adjoined
+ *          For paged aggregation:
+ *          --try to extend at EOA
+ *          --try to extend into a free-space section if adjoined
+ *          --try to extend into the page end threshold if a metadata block
  *
  * Return:	Success:	TRUE(1)  - Block was extended
  *                              FALSE(0) - Block could not be extended
@@ -825,14 +1327,16 @@ htri_t
 H5MF_try_extend(H5F_t *f, hid_t dxpl_id, H5FD_mem_t alloc_type, haddr_t addr,
     hsize_t size, hsize_t extra_requested)
 {
-    H5P_genplist_t *dxpl = NULL;        /* DXPL for setting ring */
-    H5AC_ring_t fsm_ring;               /* Free space manager ring */
-    H5AC_ring_t orig_ring = H5AC_RING_INV;      /* Original ring value */
-    haddr_t     end;                    /* End of block to extend */
-    H5FD_mem_t fs_type;			/* Memory type of the free space manager */
-    H5FD_mem_t  map_type;               /* Mapped type */
-    hbool_t reset_ring = FALSE;         /* Whether the ring was set */
-    htri_t	ret_value = FAIL;       /* Return value */
+    H5P_genplist_t *dxpl = NULL;            /* DXPL for setting ring */
+    H5AC_ring_t orig_ring = H5AC_RING_INV;  /* Original ring value */
+    H5AC_ring_t fsm_ring = H5AC_RING_INV;   /* ring of fsm */
+    haddr_t end;                            /* End of block to extend */
+    H5FD_mem_t  map_type;                   /* Mapped type */
+    H5F_mem_page_t fs_type;                 /* free space type */
+    htri_t allow_extend = TRUE;		    /* Possible to extend the block */
+    hsize_t frag_size = 0;                  /* Size of mis-aligned fragment */
+    hbool_t reset_ring = FALSE;             /* Whether the ring was set */
+    htri_t ret_value = FALSE;      	    /* Return value */
 
     FUNC_ENTER_NOAPI_TAG(dxpl_id, H5AC__FREESPACE_TAG, FAIL)
 #ifdef H5MF_ALLOC_DEBUG
@@ -849,12 +1353,33 @@ HDfprintf(stderr, "%s: Entering: alloc_type = %u, addr = %a, size = %Hu, extra_r
     /* Compute end of block to extend */
     end = addr + size;
 
+    /* For paged aggregation:
+     *   To extend a small block: can only extend if not crossing page boundary 
+     *   To extend a large block at EOA: calculate in advance mis-aligned fragment so EOA will still end at page boundary
+     */
+    if(H5F_PAGED_AGGR(f)) {
+        if(size < f->shared->fs_page_size) {
+            /* To extend a small block: cannot cross page boundary */
+            if((addr / f->shared->fs_page_size) != (((end + extra_requested) - 1) / f->shared->fs_page_size))
+                allow_extend = FALSE;
+        } /* end if */
+        else {
+            haddr_t eoa;  /* EOA for the file */
+
+            /*   To extend a large block: calculate in advance the mis-aligned fragment so EOA will end at page boundary if extended */
+            if(HADDR_UNDEF == (eoa = H5F_get_eoa(f, alloc_type)))
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "Unable to get eoa")
+            HDassert(!(eoa % f->shared->fs_page_size));
+
+            H5MF_EOA_MISALIGN(f, (eoa+extra_requested), f->shared->fs_page_size, frag_size);
+        } /* end else */
+    } /* end if */
+
     /* Get free space type from allocation type */
-    fs_type = H5MF_ALLOC_TO_FS_TYPE(f, alloc_type);
+    H5MF_alloc_to_fs_type(f, alloc_type, size, &fs_type);
 
     /* Set the ring type in the DXPL */
-    if((fs_type == H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_HDR))
-            || (fs_type == H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_SINFO)))
+    if(H5MF__fsm_type_is_self_referential(f, fs_type))
         fsm_ring = H5AC_RING_MDFSM;
     else
         fsm_ring = H5AC_RING_RDFSM;
@@ -862,29 +1387,90 @@ HDfprintf(stderr, "%s: Entering: alloc_type = %u, addr = %a, size = %Hu, extra_r
         HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value")
     reset_ring = TRUE;
 
-    /* Check if the block is exactly at the end of the file */
-    if((ret_value = H5FD_try_extend(f->shared->lf, map_type, f, dxpl_id, end, extra_requested)) < 0)
-        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTEXTEND, FAIL, "error extending file")
-    else if(ret_value == FALSE) {
-        H5F_blk_aggr_t *aggr;   /* Aggregator to use */
+    if(allow_extend) {
+        /* Try extending the block at EOA */
+        if((ret_value = H5F_try_extend(f, dxpl_id, map_type, end, extra_requested + frag_size)) < 0)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTEXTEND, FAIL, "error extending file")
+#ifdef H5MF_ALLOC_DEBUG_MORE
+HDfprintf(stderr, "%s: extended = %t\n", FUNC, ret_value);
+#endif /* H5MF_ALLOC_DEBUG_MORE */
+
+        /* If extending at EOA succeeds: */
+        /*   for paged aggregation, put the fragment into the large-sized free-space manager */
+        if(ret_value == TRUE && H5F_PAGED_AGGR(f) && frag_size) {
+            H5MF_free_section_t *node = NULL;   /* Free space section pointer */
 
-        /* Check for test block able to extend aggregation block */
-        aggr = (map_type == H5FD_MEM_DRAW) ?  &(f->shared->sdata_aggr) : &(f->shared->meta_aggr);
-        if((ret_value = H5MF_aggr_try_extend(f, dxpl_id, aggr, map_type, end, extra_requested)) < 0)
-            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTEXTEND, FAIL, "error extending aggregation block")
-        else if(ret_value == FALSE) {
+            /* Should be large-sized block */
+            HDassert(size >= f->shared->fs_page_size);
+
+            /* Start up the free-space manager */
+            if(!(f->shared->fs_man[fs_type]))
+                if(H5MF_start_fstype(f, dxpl_id, fs_type) < 0)
+                    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't initialize file free space")
+
+            /* Create free space section for the fragment */
+            if(NULL == (node = H5MF_sect_new(H5MF_FSPACE_SECT_LARGE, end + extra_requested, frag_size)))
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't initialize free space section")
+
+            /* Add the fragment to the large-sized free-space manager */
+            if(H5MF_add_sect(f, alloc_type, dxpl_id, f->shared->fs_man[fs_type], node) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINSERT, FAIL, "can't re-add section to file free space")
+
+            node = NULL;
+        } /* end if */
+
+        /* For non-paged aggregation: try to extend into the aggregators */
+        if(ret_value == FALSE && (f->shared->fs_strategy == H5F_FSPACE_STRATEGY_FSM_AGGR ||
+                                  f->shared->fs_strategy == H5F_FSPACE_STRATEGY_AGGR) ) {
+            H5F_blk_aggr_t *aggr;   /* Aggregator to use */
+
+            /* Check if the block is able to extend into aggregation block */
+            aggr = (map_type == H5FD_MEM_DRAW) ?  &(f->shared->sdata_aggr) : &(f->shared->meta_aggr);
+            if((ret_value = H5MF_aggr_try_extend(f, dxpl_id, aggr, map_type, end, extra_requested)) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTEXTEND, FAIL, "error extending aggregation block")
+
+#ifdef H5MF_ALLOC_DEBUG_MORE
+HDfprintf(stderr, "%s: H5MF_aggr_try_extend = %t\n", FUNC, ret_value);
+#endif /* H5MF_ALLOC_DEBUG_MORE */
+        } /* end if */
+
+        /* If no extension so far, try to extend into a free-space section */
+        if(ret_value == FALSE && ((f->shared->fs_strategy == H5F_FSPACE_STRATEGY_FSM_AGGR) ||
+                                  (H5F_PAGED_AGGR(f))) ) {
+            H5MF_sect_ud_t udata;       /* User data */
+
+            /* Construct user data for callbacks */
+            udata.f = f;
+            udata.dxpl_id = dxpl_id;
+            udata.alloc_type = alloc_type;
 
             /* Check if the free space for the file has been initialized */
             if(!f->shared->fs_man[fs_type] && H5F_addr_defined(f->shared->fs_addr[fs_type]))
-                if(H5MF__alloc_open(f, dxpl_id, fs_type) < 0)
+                /* Open the free-space manager */
+                if(H5MF_open_fstype(f, dxpl_id, fs_type) < 0)
                     HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't initialize file free space")
 
-            /* Check for test block able to block in free space manager */
-            if(f->shared->fs_man[fs_type])
-                if((ret_value = H5FS_sect_try_extend(f, dxpl_id, f->shared->fs_man[fs_type], addr, size, extra_requested)) < 0)
+            /* Try to extend the block into a free-space section */
+            if(f->shared->fs_man[fs_type]) {
+                if((ret_value = H5FS_sect_try_extend(f, dxpl_id, f->shared->fs_man[fs_type], addr, size, extra_requested, H5FS_ADD_RETURNED_SPACE, &udata)) < 0)
                     HGOTO_ERROR(H5E_RESOURCE, H5E_CANTEXTEND, FAIL, "error extending block in free space manager")
+#ifdef H5MF_ALLOC_DEBUG_MORE
+HDfprintf(stderr, "%s: Try to H5FS_sect_try_extend = %t\n", FUNC, ret_value);
+#endif /* H5MF_ALLOC_DEBUG_MORE */
+            } /* end if */
+
+            /* For paged aggregation and a metadata block: try to extend into page end threshold */
+            if(ret_value == FALSE && H5F_PAGED_AGGR(f) && map_type != H5FD_MEM_DRAW) {
+                H5MF_EOA_MISALIGN(f, end, f->shared->fs_page_size, frag_size);
+
+                if(frag_size <= H5F_PGEND_META_THRES(f) && extra_requested <= frag_size)
+                    ret_value = TRUE;
+#ifdef H5MF_ALLOC_DEBUG_MORE
+HDfprintf(stderr, "%s: Try to extend into the page end threshold = %t\n", FUNC, ret_value);
+#endif /* H5MF_ALLOC_DEBUG_MORE */
+            } /* end if */
         } /* end if */
-    } /* end else-if */
+    } /* allow_extend */
 
 done:
     /* Reset the ring in the DXPL */
@@ -904,174 +1490,316 @@ H5MF_sects_dump(f, dxpl_id, stderr);
 
 
 /*-------------------------------------------------------------------------
- * Function:    H5MF_get_freespace
+ * Function:    H5MF_try_shrink
  *
- * Purpose:     Retrieve the amount of free space in a file.
+ * Purpose:     Try to shrink the size of a file with a block or absorb it
+ *              into a block aggregator.
  *
- * Return:      Success:        Amount of free space in file
- *              Failure:        Negative
+ * Return:      Non-negative on success/Negative on failure
  *
  * Programmer:  Quincey Koziol
- *              Monday, October  6, 2003
+ *              koziol@hdfgroup.org
+ *              Feb 14 2008
  *
- * Modifications:
- *      Vailin Choi; July 2012
- *      As the default free-list mapping is changed to H5FD_FLMAP_DICHOTOMY,
- *      checks are added to account for the last section of each free-space manager
- *      and the remaining space in the two aggregators are at EOF.
  *-------------------------------------------------------------------------
  */
-herr_t
-H5MF_get_freespace(H5F_t *f, hid_t dxpl_id, hsize_t *tot_space, hsize_t *meta_size)
+htri_t
+H5MF_try_shrink(H5F_t *f, H5FD_mem_t alloc_type, hid_t dxpl_id, haddr_t addr,
+    hsize_t size)
 {
-    H5P_genplist_t *dxpl = NULL; /* DXPL for setting ring */
-    H5AC_ring_t curr_ring;      /* Current ring value */
-    H5AC_ring_t needed_ring;    /* Ring value needed for loop iteration  */
-    H5AC_ring_t orig_ring = H5AC_RING_INV;      /* Original ring value */
-    haddr_t eoa;                /* End of allocated space in the file */
-    haddr_t ma_addr = HADDR_UNDEF;    /* Base "metadata aggregator" address */
-    hsize_t ma_size = 0;        /* Size of "metadata aggregator" */
-    haddr_t sda_addr = HADDR_UNDEF;    /* Base "small data aggregator" address */
-    hsize_t sda_size = 0;       /* Size of "small data aggregator" */
-    hsize_t tot_fs_size = 0;    /* Amount of all free space managed */
-    hsize_t tot_meta_size = 0;  /* Amount of metadata for free space managers */
-    H5FD_mem_t type;            /* Memory type for iteration */
-    hbool_t fs_started[H5FD_MEM_NTYPES]; /* Indicate whether the free-space manager has been started */
-    hbool_t eoa_shrank;		/* Whether an EOA shrink occurs */
-    hbool_t reset_ring = FALSE; /* Whether the ring was set */
-    herr_t ret_value = SUCCEED; /* Return value */
+    H5MF_free_section_t *node = NULL;   /* Free space section pointer */
+    H5MF_sect_ud_t udata;               /* User data for callback */
+    H5FS_section_class_t *sect_cls;	/* Section class */
+    H5P_genplist_t *dxpl = NULL;        /* DXPL for setting ring */
+    H5AC_ring_t orig_ring = H5AC_RING_INV;  /* Original ring value */
+    H5AC_ring_t fsm_ring = H5AC_RING_INV;   /* Ring of fsm */
+    H5F_mem_page_t fs_type;                 /* Free space type */
+    hbool_t reset_ring = FALSE;             /* Whether the ring was set */
+    htri_t ret_value = FAIL;                /* Return value */
 
     FUNC_ENTER_NOAPI_TAG(dxpl_id, H5AC__FREESPACE_TAG, FAIL)
+#ifdef H5MF_ALLOC_DEBUG
+HDfprintf(stderr, "%s: Entering - alloc_type = %u, addr = %a, size = %Hu\n", FUNC, (unsigned)alloc_type, addr, size);
+#endif /* H5MF_ALLOC_DEBUG */
 
-    /* check args */
+    /* check arguments */
     HDassert(f);
     HDassert(f->shared);
     HDassert(f->shared->lf);
+    HDassert(H5F_addr_defined(addr));
+    HDassert(size > 0);
 
-    /* Retrieve the 'eoa' for the file */
-    if(HADDR_UNDEF == (eoa = H5F_get_eoa(f, H5FD_MEM_DEFAULT)))
-	HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "driver get_eoa request failed")
+    /* Set up free-space section class information */
+    sect_cls = H5MF_SECT_CLS_TYPE(f, size);
+    HDassert(sect_cls);
+
+    /* Get free space type from allocation type */
+    H5MF_alloc_to_fs_type(f, alloc_type, size, &fs_type);
 
     /* Set the ring type in the DXPL */
-    if(H5AC_set_ring(dxpl_id, H5AC_RING_RDFSM, &dxpl, &orig_ring) < 0)
+    if(H5MF__fsm_type_is_self_referential(f, fs_type))
+        fsm_ring = H5AC_RING_MDFSM;
+    else
+        fsm_ring = H5AC_RING_RDFSM;
+    if(H5AC_set_ring(dxpl_id, fsm_ring, &dxpl, &orig_ring) < 0)
         HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value")
     reset_ring = TRUE;
-    curr_ring = H5AC_RING_RDFSM;
 
-    /* Retrieve metadata aggregator info, if available */
-    if(H5MF_aggr_query(f, &(f->shared->meta_aggr), &ma_addr, &ma_size) < 0)
-        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "can't query metadata aggregator stats")
+    /* Create free-space section for block */
+    if(NULL == (node = H5MF_sect_new(sect_cls->type, addr, size)))
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't initialize free space section")
 
-    /* Retrieve 'small data' aggregator info, if available */
-    if(H5MF_aggr_query(f, &(f->shared->sdata_aggr), &sda_addr, &sda_size) < 0)
-        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "can't query small data aggregator stats")
+    /* Construct user data for callbacks */
+    udata.f = f;
+    udata.dxpl_id = dxpl_id;
+    udata.alloc_type = alloc_type;
+    udata.allow_sect_absorb = FALSE;    /* Force section to be absorbed into aggregator */
+    udata.allow_eoa_shrink_only = FALSE;
 
-    /* Iterate over all the free space types that have managers and get each free list's space */
-    for(type = H5FD_MEM_DEFAULT; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type)) {
+    /* Check if the block can shrink the container */
+    if(sect_cls->can_shrink) {
+        if((ret_value = (*sect_cls->can_shrink)((const H5FS_section_info_t *)node, &udata)) < 0)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTMERGE, FAIL, "can't check if section can shrink container")
+        if(ret_value > 0) {
+            HDassert(sect_cls->shrink);
 
-	fs_started[type] = FALSE;
+            if((*sect_cls->shrink)((H5FS_section_info_t **)&node, &udata) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSHRINK, FAIL, "can't shrink container")
+        } /* end if */
+    } /* end if */
 
-        /* test to see if we need to switch rings -- do so if required */
-        if((type == H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_HDR))
-                || (type == H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_SINFO)))
-            needed_ring = H5AC_RING_MDFSM;
-        else
-            needed_ring = H5AC_RING_RDFSM;
+done:
+    /* Reset the ring in the DXPL */
+    if(reset_ring)
+        if(H5AC_reset_ring(dxpl, orig_ring) < 0)
+            HDONE_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set property value")
 
-        if(needed_ring != curr_ring) {
-            if(H5AC_set_ring(dxpl_id, needed_ring, &dxpl, &curr_ring) < 0)
-                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value (2)")
-            curr_ring = needed_ring;
-        } /* end if */
+    /* Free section node allocated */
+    if(node && H5MF_sect_free((H5FS_section_info_t *)node) < 0)
+        HDONE_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't free simple section node")
 
-	/* Check if the free space for the file has been initialized */
-        if(!f->shared->fs_man[type] && H5F_addr_defined(f->shared->fs_addr[type])) {
-            if(H5MF__alloc_open(f, dxpl_id, type) < 0)
-                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't initialize file free space")
-            HDassert(f->shared->fs_man[type]);
-            fs_started[type] = TRUE;
-        } /* end if */
+#ifdef H5MF_ALLOC_DEBUG
+HDfprintf(stderr, "%s: Leaving, ret_value = %d\n", FUNC, ret_value);
+#endif /* H5MF_ALLOC_DEBUG */
+    FUNC_LEAVE_NOAPI_TAG(ret_value, FAIL)
+} /* end H5MF_try_shrink() */
 
-	/* Check if there's free space of this type */
-        if(f->shared->fs_man[type]) {
-            hsize_t type_fs_size = 0;    /* Amount of free space managed for each type */
-            hsize_t type_meta_size = 0;  /* Amount of free space metadata for each type */
+
+/*-------------------------------------------------------------------------
+ * Function:    H5MF_close
+ *
+ * Purpose:     Close the free space tracker(s) for a file:
+ *              paged or non-paged aggregation
+ *
+ * Return:	SUCCEED/FAIL
+ *
+ * Programmer:  Vailin Choi; Dec 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5MF_close(H5F_t *f, hid_t dxpl_id)
+{
+    herr_t ret_value = SUCCEED;         /* Return value */
 
-            /* Retrieve free space size from free space manager */
-            if(H5FS_sect_stats(f->shared->fs_man[type], &type_fs_size, NULL) < 0)
-                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "can't query free space stats")
-            if(H5FS_size(f, f->shared->fs_man[type], &type_meta_size) < 0)
-                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "can't query free space metadata stats")
+    FUNC_ENTER_NOAPI_TAG(dxpl_id, H5AC__FREESPACE_TAG, FAIL)
+#ifdef H5MF_ALLOC_DEBUG
+HDfprintf(stderr, "%s: Entering\n", FUNC);
+#endif /* H5MF_ALLOC_DEBUG */
 
-            /* Increment total free space for types */
-            tot_fs_size += type_fs_size;
-            tot_meta_size += type_meta_size;
-	} /* end if */
-    } /* end for */
+    /* check args */
+    HDassert(f);
+    HDassert(f->shared);
 
-    /* Iterate until no more EOA shrink occurs */
-    do {
-	eoa_shrank = FALSE;
+    if(H5F_PAGED_AGGR(f)) {
+        if((ret_value = H5MF__close_pagefs(f, dxpl_id)) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTFREE, FAIL, "can't close free-space managers for 'page' file space")
+    } /* end if */
+    else {
+        if((ret_value = H5MF__close_aggrfs(f, dxpl_id)) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTFREE, FAIL, "can't close free-space managers for 'aggr' file space")
+    } /* end else */
 
-	/* Check the last section of each free-space manager */
-	for(type = H5FD_MEM_DEFAULT; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type)) {
-	    haddr_t sect_addr = HADDR_UNDEF;
-	    hsize_t sect_size = 0;
-
-	    if(f->shared->fs_man[type]) {
-		if(H5FS_sect_query_last_sect(f->shared->fs_man[type], &sect_addr, &sect_size) < 0)
-		    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "can't query last section on merge list")
-
-		/* Deduct space from previous accumulation if the section is at EOA */
-		if(H5F_addr_eq(sect_addr + sect_size, eoa)) {
-		    eoa = sect_addr;
-		    eoa_shrank = TRUE;
-		    tot_fs_size -= sect_size;
-		} /* end if */
-	    } /* end if */
-	} /* end for */
-
-	/* Check the metadata and raw data aggregators */
-	if(ma_size > 0 && H5F_addr_eq(ma_addr + ma_size, eoa)) {
-	    eoa = ma_addr;
-	    eoa_shrank = TRUE;
-	    ma_size = 0;
-	} /* end if */
-	if(sda_size > 0 && H5F_addr_eq(sda_addr + sda_size, eoa)) {
-	    eoa = sda_addr;
-	    eoa_shrank = TRUE;
-	    sda_size = 0;
-	} /* end if */
-    } while(eoa_shrank);
+done:
 
-    /* Close the free-space managers if they were opened earlier in this routine */
-    for(type = H5FD_MEM_DEFAULT; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type)) {
-        if(fs_started[type]) {
+#ifdef H5MF_ALLOC_DEBUG
+HDfprintf(stderr, "%s: Leaving\n", FUNC);
+#endif /* H5MF_ALLOC_DEBUG */
+    FUNC_LEAVE_NOAPI_TAG(ret_value, FAIL)
+} /* end H5MF_close() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5MF__close_delete_fstype
+ *
+ * Purpose:     Common code for closing and deleting the freespace manager
+ *              of TYPE for file.
+ *              Note that TYPE can be H5F_mem_page_t or H5FD_mem_t enum types.
+ *
+ * Return:	SUCCEED/FAIL
+ *
+ * Programmer:	Vailin Choi
+ *              Jan 2016
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5MF__close_delete_fstype(H5F_t *f, hid_t dxpl_id, H5F_mem_page_t type)
+{
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_STATIC_TAG(dxpl_id, H5AC__FREESPACE_TAG, FAIL)
+#ifdef H5MF_ALLOC_DEBUG
+HDfprintf(stderr, "%s: Entering\n", FUNC);
+#endif /* H5MF_ALLOC_DEBUG */
+
+    /* check args */
+    HDassert(f);
+    HDassert(f->shared);
+    if(H5F_PAGED_AGGR(f))
+        HDassert(type < H5F_MEM_PAGE_NTYPES);
+    else
+        HDassert((H5FD_mem_t)type < H5FD_MEM_NTYPES);
+
+#ifdef H5MF_ALLOC_DEBUG_MORE
+HDfprintf(stderr, "%s: Check 1.0 - f->shared->fs_man[%u] = %p, f->shared->fs_addr[%u] = %a\n", FUNC, (unsigned)type, f->shared->fs_man[type], (unsigned)type, f->shared->fs_addr[type]);
+#endif /* H5MF_ALLOC_DEBUG_MORE */
+
+    /* If the free space manager for this type is open, close it */
+    if(f->shared->fs_man[type])
+        if(H5MF__close_fstype(f, dxpl_id, type) < 0)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't close the free space manager")
+
+#ifdef H5MF_ALLOC_DEBUG_MORE
+HDfprintf(stderr, "%s: Check 2.0 - f->shared->fs_man[%u] = %p, f->shared->fs_addr[%u] = %a\n", FUNC, (unsigned)type, f->shared->fs_man[type], (unsigned)type, f->shared->fs_addr[type]);
+#endif /* H5MF_ALLOC_DEBUG_MORE */
+
+    /* If there is free space manager info for this type, delete it */
+    if(H5F_addr_defined(f->shared->fs_addr[type]))
+        if(H5MF__delete_fstype(f, dxpl_id, type) < 0)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't delete the free space manager")
+
+done:
+#ifdef H5MF_ALLOC_DEBUG
+HDfprintf(stderr, "%s: Leaving\n", FUNC);
+#endif /* H5MF_ALLOC_DEBUG */
+    FUNC_LEAVE_NOAPI_TAG(ret_value, FAIL)
+} /* H5MF__close_delete() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5MF_try_close
+ *
+ * Purpose:     This is called by H5Fformat_convert() to close and delete
+ *              free-space managers when downgrading persistent free-space
+ *              to non-persistent.
+ *
+ * Return:	SUCCEED/FAIL
+ *
+ * Programmer:	Vailin Choi
+ *              Jan 2016
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5MF_try_close(H5F_t *f, hid_t dxpl_id)
+{
+    H5P_genplist_t *dxpl = NULL;        /* DXPL for setting ring */
+    H5AC_ring_t curr_ring = H5AC_RING_INV;      /* Current ring value */
+    H5AC_ring_t needed_ring = H5AC_RING_INV;    /* Ring value needed for this iteration  */
+    H5AC_ring_t orig_ring = H5AC_RING_INV;      /* Original ring value */
+    hbool_t reset_ring = FALSE;         /* Whether the ring was set */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI_TAG(dxpl_id, H5AC__FREESPACE_TAG, FAIL)
+#ifdef H5MF_ALLOC_DEBUG
+HDfprintf(stderr, "%s: Entering\n", FUNC);
+#endif /* H5MF_ALLOC_DEBUG */
+
+    /* check args */
+    HDassert(f);
+
+    /* If there have been no file space allocations / deallocation so 
+     * far, must call H5MF_tidy_self_referential_fsm_hack() to float 
+     * all self referential FSMs and release file space allocated to
+     * them.  Otherwise, the function will be called after the format
+     * conversion, and will become very confused.
+     *
+     * The situation is further complicated if a cache image exists
+     * and had not yet been loaded into the metadata cache.  In this
+     * case, call H5AC_force_cache_image_load() instead of 
+     * H5MF_tidy_self_referential_fsm_hack().  H5AC_force_cache_image_load()
+     * will load the cache image, and then call 
+     * H5MF_tidy_self_referential_fsm_hack() to discard the cache image 
+     * block.
+     */
+    if(f->shared->first_alloc_dealloc) {
+        if(H5AC_cache_image_pending(f)) {
+            if(H5AC_force_cache_image_load(f, dxpl_id) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, FAIL, "forced cache image load failed")
+        } /* end if */
+        else {
+            if(H5MF_tidy_self_referential_fsm_hack(f, dxpl_id) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, FAIL, "tidy of self referential fsm hack failed")
+        } /* end else */
+    } /* end if */
+
+    /* Set the ring type in the DXPL.  In most cases, we will
+     * need H5AC_RING_RDFSM, so initialy set the ring in
+     * the DXPL to that value.  We will alter this later if
+     * needed.
+     */
+    if(H5AC_set_ring(dxpl_id, H5AC_RING_RDFSM, &dxpl, &orig_ring) < 0)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value")
+    reset_ring = TRUE;
+    curr_ring = H5AC_RING_RDFSM;
+
+    if(H5F_PAGED_AGGR(f)) {
+        H5F_mem_page_t ptype; 	/* Memory type for iteration */
 
+        /* Iterate over all the free space types that have managers and 
+         * get each free list's space 
+         */
+        for(ptype = H5F_MEM_PAGE_META; ptype < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, ptype)) {
+            /* Test to see if we need to switch rings -- do so if required */
+            if(H5MF__fsm_type_is_self_referential(f, ptype))
+                needed_ring = H5AC_RING_MDFSM;
+            else
+                needed_ring = H5AC_RING_RDFSM;
+
+            if(needed_ring != curr_ring ) {
+                if(H5AC_set_ring(dxpl_id, needed_ring, &dxpl, &curr_ring) < 0)
+                    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value (1)")
+                curr_ring = needed_ring;
+            } /* end if */
+
+            if(H5MF__close_delete_fstype(f, dxpl_id, ptype) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't close the free space manager")
+        } /* end for */
+    } /* end if */
+    else {
+        H5FD_mem_t type;          	/* Memory type for iteration */
+
+        /* Iterate over all the free space types that have managers and 
+         * get each free list's space 
+         */
+        for(type = H5FD_MEM_DEFAULT; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type)) {
             /* test to see if we need to switch rings -- do so if required */
-            if((type == H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_HDR))
-                    || (type == H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_SINFO)))
+            if(H5MF__fsm_type_is_self_referential(f, (H5F_mem_page_t)type))
                 needed_ring = H5AC_RING_MDFSM;
             else
                 needed_ring = H5AC_RING_RDFSM;
 
             if(needed_ring != curr_ring) {
                 if(H5AC_set_ring(dxpl_id, needed_ring, &dxpl, &curr_ring) < 0)
-                    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value (3)")
+                    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value")
                 curr_ring = needed_ring;
             } /* end if */
 
-            if(H5MF__alloc_close(f, dxpl_id, type) < 0)
-                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't close file free space")
-        } /* end if */
-    } /* end for */
-
-    /* Set the value(s) to return */
-    /* (The metadata & small data aggregators count as free space now, since they aren't at EOA) */
-    if(tot_space)
-	*tot_space = tot_fs_size + ma_size + sda_size;
-    if(meta_size)
-	*meta_size = tot_meta_size;
+            if(H5MF__close_delete_fstype(f, dxpl_id, (H5F_mem_page_t)type) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't close the free space manager")
+        } /* end for */
+    } /* end else */
 
 done:
     /* Reset the ring in the DXPL */
@@ -1079,75 +1807,370 @@ done:
         if(H5AC_reset_ring(dxpl, orig_ring) < 0)
             HDONE_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set property value")
 
+#ifdef H5MF_ALLOC_DEBUG
+HDfprintf(stderr, "%s: Leaving\n", FUNC);
+#endif /* H5MF_ALLOC_DEBUG */
     FUNC_LEAVE_NOAPI_TAG(ret_value, FAIL)
-} /* end H5MF_get_freespace() */
+} /* H5MF_try_close() */
 
 
 /*-------------------------------------------------------------------------
- * Function:    H5MF_try_shrink
+ * Function:    H5MF__close_aggrfs
  *
- * Purpose:     Try to shrink the size of a file with a block or absorb it
- *              into a block aggregator.
+ * Purpose:     Close the free space tracker(s) for a file: non-paged aggregation
  *
- * Return:      Non-negative on success/Negative on failure
+ * Return:      SUCCEED/FAIL
  *
  * Programmer:  Quincey Koziol
- *              koziol@hdfgroup.org
- *              Feb 14 2008
+ *              Tuesday, January 22, 2008
  *
  *-------------------------------------------------------------------------
  */
-htri_t
-H5MF_try_shrink(H5F_t *f, H5FD_mem_t alloc_type, hid_t dxpl_id, haddr_t addr,
-    hsize_t size)
+static herr_t
+H5MF__close_aggrfs(H5F_t *f, hid_t dxpl_id)
 {
-    H5MF_free_section_t *node = NULL;   /* Free space section pointer */
-    H5MF_sect_ud_t udata;               /* User data for callback */
-    htri_t ret_value = FAIL;                   /* Return value */
+    H5P_genplist_t *dxpl = NULL;        /* DXPL for setting ring */
+    H5AC_ring_t curr_ring = H5AC_RING_INV;      /* Current ring value */
+    H5AC_ring_t needed_ring = H5AC_RING_INV;    /* Ring value needed for this iteration.  */
+    H5AC_ring_t orig_ring = H5AC_RING_INV;      /* Original ring value */
+    H5FD_mem_t type;          	        /* Memory type for iteration */
+    hbool_t reset_ring = FALSE;         /* Whether the ring was set */
+    herr_t ret_value = SUCCEED;	        /* Return value */
 
-    FUNC_ENTER_NOAPI(FAIL)
+    FUNC_ENTER_STATIC_TAG(dxpl_id, H5AC__FREESPACE_TAG, FAIL)
 #ifdef H5MF_ALLOC_DEBUG
-HDfprintf(stderr, "%s: Entering - alloc_type = %u, addr = %a, size = %Hu\n", FUNC, (unsigned)alloc_type, addr, size);
+HDfprintf(stderr, "%s: Entering\n", FUNC);
 #endif /* H5MF_ALLOC_DEBUG */
 
-    /* check arguments */
+    /* check args */
     HDassert(f);
     HDassert(f->shared);
     HDassert(f->shared->lf);
-    HDassert(H5F_addr_defined(addr));
-    HDassert(size > 0);
+    HDassert(f->shared->sblock);
 
-    /* Create free space section for block */
-    if(NULL == (node = H5MF_sect_simple_new(addr, size)))
-        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't initialize free space section")
+    /* Set the ring type in the DXPL.  In most cases, we will
+     * need H5AC_RING_RDFSM, so initialy set the ring in
+     * the DXPL to that value.  We will alter this later if
+     * needed.
+     */
+    if(H5AC_set_ring(dxpl_id, H5AC_RING_RDFSM, &dxpl, &orig_ring) < 0)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value")
+    reset_ring = TRUE;
+    curr_ring = H5AC_RING_RDFSM;
 
-    /* Construct user data for callbacks */
-    udata.f = f;
-    udata.dxpl_id = dxpl_id;
-    udata.alloc_type = alloc_type;
-    udata.allow_sect_absorb = FALSE;    /* Force section to be absorbed into aggregator */
-    udata.allow_eoa_shrink_only = FALSE; 
-
-    /* Call the "can shrink" callback for the section */
-    if((ret_value = H5MF_sect_simple_can_shrink((const H5FS_section_info_t *)node, &udata)) < 0)
-        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTMERGE, FAIL, "can't check if section can shrink container")
-    else if(ret_value > 0) {
-        /* Shrink or absorb the section */
-        if(H5MF_sect_simple_shrink((H5FS_section_info_t **)&node, &udata) < 0)
-            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSHRINK, FAIL, "can't shrink container")
+    /* Free the space in aggregators */
+    /* (for space not at EOA, it may be put into free space managers) */
+    if(H5MF_free_aggrs(f, dxpl_id) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTFREE, FAIL, "can't free aggregators")
+
+    /* Trying shrinking the EOA for the file */
+    if(H5MF__close_shrink_eoa(f, dxpl_id) < 0)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSHRINK, FAIL, "can't shrink eoa")
+
+    /* Making free-space managers persistent for superblock version >= 2 */
+    if(f->shared->sblock->super_vers >= HDF5_SUPERBLOCK_VERSION_2
+            && f->shared->fs_persist) {
+        H5O_fsinfo_t fsinfo;	/* File space info message */
+        haddr_t final_eoa;      /* Final eoa -- for sanity check */
+        H5F_mem_page_t ptype;   /* Memory type for iteration */
+
+        /* superblock extension and free space manager message should
+         * exist at this point -- verify at least the former.
+         */
+        HDassert(H5F_addr_defined(f->shared->sblock->ext_addr));
+
+        /* file space for all non-empty free space managers should be 
+         * allocated at this point, and these free space managers should
+         * be written to file and thus their headers and section info 
+         * entries in the metadata cache should be clean.
+         */
+
+        /* gather data for the free space manager superblock extension message.
+         *
+         * In passing, verify that all the free space managers are closed.
+         */
+        for(ptype = H5F_MEM_PAGE_META; ptype < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, ptype))
+            fsinfo.fs_addr[ptype - 1] = HADDR_UNDEF;
+        for(type = H5FD_MEM_SUPER; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type))
+            fsinfo.fs_addr[type-1] = f->shared->fs_addr[type];
+        fsinfo.strategy = f->shared->fs_strategy;
+        fsinfo.persist = f->shared->fs_persist;
+        fsinfo.threshold = f->shared->fs_threshold;
+        fsinfo.page_size = f->shared->fs_page_size;
+        fsinfo.pgend_meta_thres = f->shared->pgend_meta_thres;
+        fsinfo.eoa_pre_fsm_fsalloc = f->shared->eoa_pre_fsm_fsalloc;
+
+        /* Write the free space manager message -- message must already exist */
+        if(H5F_super_ext_write_msg(f, dxpl_id, H5O_FSINFO_ID, &fsinfo, FALSE, H5O_MSG_FLAG_MARK_IF_UNKNOWN) < 0)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_WRITEERROR, FAIL, "error in writing message to superblock extension")
+
+        /* Close the free space managers */
+        for(type = H5FD_MEM_SUPER; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type)) {
+            if(f->shared->fs_man[type]) {
+                /* test to see if we need to switch rings -- do 
+                 * so if required 
+                 */
+                if(H5MF__fsm_type_is_self_referential(f, (H5F_mem_page_t)type))
+                    needed_ring = H5AC_RING_MDFSM;
+                else 
+                    needed_ring = H5AC_RING_RDFSM;
+
+                if(needed_ring != curr_ring) {
+                    if(H5AC_set_ring(dxpl_id, needed_ring, &dxpl, &curr_ring) < 0)
+                        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value (1)")
+                    curr_ring = needed_ring;
+                } /* end if */
+
+                HDassert(f->shared->fs_state[type] == H5F_FS_STATE_OPEN);
+
+                if(H5FS_close(f, dxpl_id, f->shared->fs_man[type]) < 0)
+                    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't close free space manager")
+                f->shared->fs_man[type] = NULL;
+                f->shared->fs_state[type] = H5F_FS_STATE_CLOSED;
+            } /* end if */
+            f->shared->fs_addr[type] = HADDR_UNDEF;
+        } /* end for */
+
+        /* verify that we haven't dirtied any metadata cache entries
+         * from the metadata free space manager ring out.
+         */
+        HDassert(H5AC_cache_is_clean(f, H5AC_RING_MDFSM));
+
+        /* verify that the aggregators are still shutdown. */
+        HDassert(f->shared->sdata_aggr.tot_size == 0);
+        HDassert(f->shared->sdata_aggr.addr == 0);
+        HDassert(f->shared->sdata_aggr.size == 0);
+
+        HDassert(f->shared->meta_aggr.tot_size == 0);
+        HDassert(f->shared->meta_aggr.addr == 0);
+        HDassert(f->shared->meta_aggr.size == 0);
+
+        /* Trying shrinking the EOA for the file */
+        /* (in case any free space is now at the EOA) */
+        if(H5MF__close_shrink_eoa(f, dxpl_id) < 0)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSHRINK, FAIL, "can't shrink eoa")
+
+        /* get the eoa, and verify that it has the expected value */
+        if(HADDR_UNDEF == (final_eoa = H5FD_get_eoa(f->shared->lf, H5FD_MEM_DEFAULT)) )
+            HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "unable to get file size")
+
+        /* f->shared->eoa_post_fsm_fsalloc is undefined if there has 
+         * been no file space allocation or deallocation since file 
+         * open.
+         */
+        HDassert((f->shared->first_alloc_dealloc) || (final_eoa == f->shared->eoa_post_fsm_fsalloc));
     } /* end if */
+    else {  /* super_vers can be 0, 1, 2 */
+        for(type = H5FD_MEM_DEFAULT; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type))
+            if(H5MF__close_delete_fstype(f, dxpl_id, (H5F_mem_page_t)type) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't initialize file free space")
+    } /* end else */
+
+    /* Free the space in aggregators (again) */
+    /* (in case any free space information re-started them) */
+    if(H5MF_free_aggrs(f, dxpl_id) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTFREE, FAIL, "can't free aggregators")
+
+    /* Trying shrinking the EOA for the file */
+    /* (in case any free space is now at the EOA) */
+    if(H5MF__close_shrink_eoa(f, dxpl_id) < 0)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSHRINK, FAIL, "can't shrink eoa")
 
 done:
+    /* Reset the ring in the DXPL */
+    if(reset_ring)
+        if(H5AC_reset_ring(dxpl, orig_ring) < 0)
+            HDONE_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set property value")
 
-    /* Free section node allocated */
-    if(node && H5MF_sect_simple_free((H5FS_section_info_t *)node) < 0)
-        HDONE_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't free simple section node")
+#ifdef H5MF_ALLOC_DEBUG
+HDfprintf(stderr, "%s: Leaving\n", FUNC);
+#endif /* H5MF_ALLOC_DEBUG */
+    FUNC_LEAVE_NOAPI_TAG(ret_value, FAIL)
+} /* end H5MF__close_aggrfs() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5MF__close_pagefs
+ *
+ * Purpose:     Close the free space tracker(s) for a file: paged aggregation
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Vailin Choi; Dec 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5MF__close_pagefs(H5F_t *f, hid_t dxpl_id)
+{
+    H5P_genplist_t *dxpl = NULL;        /* DXPL for setting ring */
+    H5AC_ring_t curr_ring = H5AC_RING_INV;      /* current ring value */
+    H5AC_ring_t needed_ring = H5AC_RING_INV;    /* ring value needed for this
+                                                 * iteration.
+                                                 */
+    H5AC_ring_t orig_ring = H5AC_RING_INV;      /* Original ring value */
+    H5F_mem_page_t ptype; 	/* Memory type for iteration */
+    H5O_fsinfo_t fsinfo;	/* File space info message */
+    hbool_t reset_ring = FALSE; /* Whether the ring was set */
+    herr_t ret_value = SUCCEED;	/* Return value */
 
+    FUNC_ENTER_STATIC_TAG(dxpl_id, H5AC__FREESPACE_TAG, FAIL)
 #ifdef H5MF_ALLOC_DEBUG
-HDfprintf(stderr, "%s: Leaving, ret_value = %d\n", FUNC, ret_value);
+HDfprintf(stderr, "%s: Entering\n", FUNC);
 #endif /* H5MF_ALLOC_DEBUG */
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5MF_try_shrink() */
+
+    /* check args */
+    HDassert(f);
+    HDassert(f->shared);
+    HDassert(f->shared->lf);
+    HDassert(f->shared->sblock);
+    HDassert(f->shared->fs_page_size);
+    HDassert(f->shared->sblock->super_vers >= HDF5_SUPERBLOCK_VERSION_2);
+
+    /* Set the ring type in the DXPL.  In most cases, we will
+     * need H5AC_RING_RDFSM, so initialy set the ring in
+     * the DXPL to that value.  We will alter this later if
+     * needed.
+     */
+    if(H5AC_set_ring(dxpl_id, H5AC_RING_RDFSM, &dxpl, &orig_ring) < 0)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value")
+    reset_ring = TRUE;
+    curr_ring = H5AC_RING_RDFSM;
+
+    /* Trying shrinking the EOA for the file */
+    if(H5MF__close_shrink_eoa(f, dxpl_id) < 0)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSHRINK, FAIL, "can't shrink eoa")
+
+    /* Set up file space info message */
+    fsinfo.strategy = f->shared->fs_strategy;
+    fsinfo.persist = f->shared->fs_persist;
+    fsinfo.threshold = f->shared->fs_threshold;
+    fsinfo.page_size = f->shared->fs_page_size;
+    fsinfo.pgend_meta_thres = f->shared->pgend_meta_thres;
+    fsinfo.eoa_pre_fsm_fsalloc = HADDR_UNDEF;
+    for(ptype = H5F_MEM_PAGE_META; ptype < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, ptype))
+        fsinfo.fs_addr[ptype - 1] = HADDR_UNDEF;
+
+    if(f->shared->fs_persist) {
+        haddr_t final_eoa;              /* final eoa -- for sanity check */
+
+        /* superblock extension and free space manager message should
+         * exist at this point -- verify at least the former.
+         */
+        HDassert(H5F_addr_defined(f->shared->sblock->ext_addr));
+
+        /* file space for all non-empty free space managers should be
+         * allocated at this point, and these free space managers should
+         * be written to file and thus their headers and section info
+         * entries in the metadata cache should be clean.
+         */
+
+        /* gather data for the free space manager superblock extension message.
+         * Only need addresses of FSMs and eoa prior to allocation of
+         * file space for the self referential free space managers.  Other 
+         * data was gathered above.
+         */
+        for(ptype = H5F_MEM_PAGE_META; ptype < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, ptype))
+            fsinfo.fs_addr[ptype-1] = f->shared->fs_addr[ptype];
+        fsinfo.eoa_pre_fsm_fsalloc = f->shared->eoa_pre_fsm_fsalloc;
+
+        /* Write the free space manager message -- message must already exist */
+        if(H5F_super_ext_write_msg(f, dxpl_id, H5O_FSINFO_ID, &fsinfo, FALSE, H5O_MSG_FLAG_MARK_IF_UNKNOWN) < 0)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_WRITEERROR, FAIL, "error in writing message to superblock extension")
+
+        /* Close the free space managers */
+        /* use H5MF__close_fstype() for this? */
+        for(ptype = H5F_MEM_PAGE_META; ptype < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, ptype)) {
+            if(f->shared->fs_man[ptype]) {
+                /* test to see if we need to switch rings -- do
+                 * so if required
+                 */
+                if(H5MF__fsm_type_is_self_referential(f, ptype))
+                    needed_ring = H5AC_RING_MDFSM;
+                else
+                    needed_ring = H5AC_RING_RDFSM;
+
+                if(needed_ring != curr_ring) {
+                    if(H5AC_set_ring(dxpl_id, needed_ring, &dxpl, &curr_ring) < 0)
+                        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value (1)")
+                    curr_ring = needed_ring;
+                } /* end if */
+
+                HDassert(f->shared->fs_state[ptype] == H5F_FS_STATE_OPEN);
+
+                if(H5FS_close(f, dxpl_id, f->shared->fs_man[ptype]) < 0)
+                    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't close free space manager")
+                f->shared->fs_man[ptype] = NULL;
+                f->shared->fs_state[ptype] = H5F_FS_STATE_CLOSED;
+            } /* end if */
+            f->shared->fs_addr[ptype] = HADDR_UNDEF;
+        } /* end for */
+
+        /* verify that we haven't dirtied any metadata cache entries
+         * from the metadata free space manager ring out.
+         */
+        HDassert(H5AC_cache_is_clean(f, H5AC_RING_MDFSM));
+
+        /* Trying shrinking the EOA for the file */
+        /* (in case any free space is now at the EOA) */
+        if(H5MF__close_shrink_eoa(f, dxpl_id) < 0)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSHRINK, FAIL, "can't shrink eoa")
+
+        /* get the eoa, and verify that it has the expected value */
+        if(HADDR_UNDEF == (final_eoa = H5FD_get_eoa(f->shared->lf, H5FD_MEM_DEFAULT)) )
+            HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "unable to get file size")
+
+        /* f->shared->eoa_post_fsm_fsalloc is undefined if there has
+         * been no file space allocation or deallocation since file
+         * open.
+         *
+         * If there is a cache image in the file at file open, 
+         * f->shared->first_alloc_dealloc will always be FALSE unless 
+         * the file is opened R/O, as otherwise, the image will have been
+         * read and discarded by this point.
+         *
+         * If a cache image was created on file close, the actual EOA 
+         * should be in f->shared->eoa_post_mdci_fsalloc.  Note that in 
+         * this case, it is conceivable that f->shared->first_alloc_dealloc
+         * will still be TRUE, as the cache image is allocated directly from
+         * the file driver layer.  However, as this possibility seems remote,
+         * it is ignored in the following assert.
+         */
+        HDassert((f->shared->first_alloc_dealloc) ||
+                 (final_eoa == f->shared->eoa_post_fsm_fsalloc) ||
+                 ((H5F_addr_defined(f->shared->eoa_post_mdci_fsalloc)) &&
+                  (final_eoa == f->shared->eoa_post_mdci_fsalloc)));
+    } /* end if */
+    else {
+        /* Iterate over all the free space types that have managers 
+         * and get each free list's space 
+         */
+        for(ptype = H5F_MEM_PAGE_META; ptype < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, ptype))
+            if(H5MF__close_delete_fstype(f, dxpl_id, ptype) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't close the free space manager")
+
+        /* Write file space info message to superblock extension object header */
+        /* Create the superblock extension object header in advance if needed */
+        if(H5F_super_ext_write_msg(f, dxpl_id, H5O_FSINFO_ID, &fsinfo, FALSE, H5O_MSG_FLAG_MARK_IF_UNKNOWN) < 0)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_WRITEERROR, FAIL, "error in writing message to superblock extension")
+    } /* end else */
+
+    /* Trying shrinking the EOA for the file */
+    /* (in case any free space is now at the EOA) */
+    if(H5MF__close_shrink_eoa(f, dxpl_id) < 0)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSHRINK, FAIL, "can't shrink eoa")
+
+done:
+    /* Reset the ring in the DXPL */
+    if(reset_ring)
+        if(H5AC_reset_ring(dxpl, orig_ring) < 0)
+            HDONE_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set property value")
+
+#ifdef H5MF_ALLOC_DEBUG
+HDfprintf(stderr, "%s: Leaving\n", FUNC);
+#endif /* H5MF_ALLOC_DEBUG */
+    FUNC_LEAVE_NOAPI_TAG(ret_value, FAIL)
+} /* end H5MF__close_pagefs() */
 
 
 /*-------------------------------------------------------------------------
@@ -1165,17 +2188,16 @@ HDfprintf(stderr, "%s: Leaving, ret_value = %d\n", FUNC, ret_value);
 static herr_t
 H5MF__close_shrink_eoa(H5F_t *f, hid_t dxpl_id)
 {
-    H5FD_mem_t type;            /* Memory type for iteration */
     H5P_genplist_t *dxpl = NULL;        /* DXPL for setting ring */
+    H5AC_ring_t curr_ring = H5AC_RING_INV;      /* Current ring value */
+    H5AC_ring_t needed_ring = H5AC_RING_INV;    /* Ring value needed for this iteration.  */
     H5AC_ring_t orig_ring = H5AC_RING_INV;      /* Original ring value */
-    H5AC_ring_t curr_ring = H5AC_RING_INV;      /* current ring value */
-    H5AC_ring_t needed_ring = H5AC_RING_INV;    /* ring value needed for this
-                                                 * iteration.
-                                                 */
+    H5F_mem_t type;
+    H5F_mem_page_t ptype;        /* Memory type for iteration */
     hbool_t eoa_shrank;		/* Whether an EOA shrink occurs */
-    hbool_t reset_ring = FALSE; /* Whether the ring was set */
     htri_t status;		/* Status value */
     H5MF_sect_ud_t udata;	/* User data for callback */
+    hbool_t reset_ring = FALSE; /* Whether the ring was set */
     herr_t ret_value = SUCCEED;	/* Return value */
 
     FUNC_ENTER_STATIC_TAG(dxpl_id, H5AC__FREESPACE_TAG, FAIL)
@@ -1187,13 +2209,10 @@ H5MF__close_shrink_eoa(H5F_t *f, hid_t dxpl_id)
     /* Construct user data for callbacks */
     udata.f = f;
     udata.dxpl_id = dxpl_id;
-    udata.allow_sect_absorb = FALSE;    
-    udata.allow_eoa_shrink_only = TRUE; 
+    udata.allow_sect_absorb = FALSE;
+    udata.allow_eoa_shrink_only = TRUE;
 
-    /* Set the ring type in the DXPL.  In most cases, we will 
-     * need H5AC_RING_RDFSM, so initialy set the ring type in 
-     * the DXPL to that value.  We will alter this later if needed.
-     */
+    /* Set the ring type in the DXPL */
     if(H5AC_set_ring(dxpl_id, H5AC_RING_RDFSM, &dxpl, &orig_ring) < 0)
         HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value(1)")
     reset_ring = TRUE;
@@ -1203,36 +2222,62 @@ H5MF__close_shrink_eoa(H5F_t *f, hid_t dxpl_id)
     do {
 	eoa_shrank = FALSE;
 
-	/* Check the last section of each free-space manager */
-	for(type = H5FD_MEM_DEFAULT; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type)) {
+        if(H5F_PAGED_AGGR(f)) {
+            /* Check the last section of each free-space manager */
+            for(ptype = H5F_MEM_PAGE_META; ptype < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, ptype)) {
+                if(f->shared->fs_man[ptype]) {
+                    /* Test to see if we need to switch rings -- do so if required */
+                    if(H5MF__fsm_type_is_self_referential(f, ptype))
+                        needed_ring = H5AC_RING_MDFSM;
+                    else
+                        needed_ring = H5AC_RING_RDFSM;
 
-            /* test to see if we need to switch rings -- do so if required */
-            if((H5MF_ALLOC_TO_FS_TYPE(f, type) == H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_HDR))
-                    || (H5MF_ALLOC_TO_FS_TYPE(f, type) == H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_SINFO)))
-                needed_ring = H5AC_RING_MDFSM;
-            else
-                needed_ring = H5AC_RING_RDFSM;
+                    if(needed_ring != curr_ring) {
+                        if(H5AC_set_ring(dxpl_id, needed_ring, &dxpl, &curr_ring) < 0)
+                            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value (1)")
+                        curr_ring = needed_ring;
+                    } /* end if */
 
-            if(needed_ring != curr_ring) {
-                if(H5AC_set_ring(dxpl_id, needed_ring, &dxpl, &curr_ring) < 0)
-                    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value (2)")
-                curr_ring = needed_ring;
-            } /* end if */
+                    udata.alloc_type = (H5FD_mem_t)((H5FD_mem_t)ptype < H5FD_MEM_NTYPES ? ptype : ((ptype % H5FD_MEM_NTYPES) + 1));
 
-	    if(f->shared->fs_man[type]) {
-		udata.alloc_type = type;
-		if((status = H5FS_sect_try_shrink_eoa(f, dxpl_id, f->shared->fs_man[type], &udata)) < 0)
-		    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSHRINK, FAIL, "can't check for shrinking eoa")
-		else if(status > 0)
-		    eoa_shrank = TRUE;
-	    } /* end if */
-	} /* end for */
+                    if((status = H5FS_sect_try_shrink_eoa(f, dxpl_id, f->shared->fs_man[ptype], &udata)) < 0)
+                        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSHRINK, FAIL, "can't check for shrinking eoa")
+                    else if(status > 0)
+                        eoa_shrank = TRUE;
+                } /* end if */
+            } /* end for */
+        } /* end if */
+        else {
+            /* Check the last section of each free-space manager */
+            for(type = H5FD_MEM_DEFAULT; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type)) {
+                if(f->shared->fs_man[type]) {
+                    /* Test to see if we need to switch rings -- do so if required */
+                    if(H5MF__fsm_type_is_self_referential(f, (H5F_mem_page_t)type))
+                        needed_ring = H5AC_RING_MDFSM;
+                    else
+                        needed_ring = H5AC_RING_RDFSM;
+
+                    if(needed_ring != curr_ring) {
+                        if(H5AC_set_ring(dxpl_id, needed_ring, &dxpl, &curr_ring) < 0)
+                            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value (1)")
+                        curr_ring = needed_ring;
+                    } /* end if */
 
-	/* check the two aggregators */
-	if((status = H5MF_aggrs_try_shrink_eoa(f, dxpl_id)) < 0)
-	    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSHRINK, FAIL, "can't check for shrinking eoa")
-	else if(status > 0)
-	    eoa_shrank = TRUE;
+                    udata.alloc_type = type;
+
+                    if((status = H5FS_sect_try_shrink_eoa(f, dxpl_id, f->shared->fs_man[type], &udata)) < 0)
+                        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSHRINK, FAIL, "can't check for shrinking eoa")
+                else if(status > 0)
+                    eoa_shrank = TRUE;
+                } /* end if */
+            } /* end for */
+
+            /* check the two aggregators */
+            if((status = H5MF_aggrs_try_shrink_eoa(f, dxpl_id)) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSHRINK, FAIL, "can't check for shrinking eoa")
+            else if(status > 0)
+                eoa_shrank = TRUE;
+        } /* end else */
     } while(eoa_shrank);
 
 done:
@@ -1246,6 +2291,370 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:    H5MF_get_freespace
+ *
+ * Purpose:     Retrieve the amount of free space in the file
+ *
+ * Return:      Success:        Amount of free space in file
+ *              Failure:        Negative
+ *
+ * Programmer:  Quincey Koziol
+ *              Monday, October  6, 2003
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5MF_get_freespace(H5F_t *f, hid_t dxpl_id, hsize_t *tot_space, hsize_t *meta_size)
+{
+    haddr_t ma_addr = HADDR_UNDEF;  /* Base "metadata aggregator" address */
+    hsize_t ma_size = 0;            /* Size of "metadata aggregator" */
+    haddr_t sda_addr = HADDR_UNDEF; /* Base "small data aggregator" address */
+    hsize_t sda_size = 0;           /* Size of "small data aggregator" */
+    hsize_t tot_fs_size = 0;        /* Amount of all free space managed */
+    hsize_t tot_meta_size = 0;      /* Amount of metadata for free space managers */
+    H5FD_mem_t tt;                  /* Memory type for iteration */
+    H5F_mem_page_t type;            /* Memory type for iteration */
+    H5F_mem_page_t start_type;      /* Memory type for iteration */
+    H5F_mem_page_t end_type;        /* Memory type for iteration */
+    htri_t fs_started[H5F_MEM_PAGE_NTYPES]; /* Indicate whether the free-space manager has been started */
+    haddr_t fs_eoa[H5FD_MEM_NTYPES];        /* EAO for each free-space manager */
+    H5P_genplist_t *dxpl = NULL;            /* DXPL for setting ring */
+    H5AC_ring_t curr_ring = H5AC_RING_INV;      /* Current ring value */
+    H5AC_ring_t needed_ring = H5AC_RING_INV;    /* Ring value needed for this iteration.  */
+    H5AC_ring_t orig_ring = H5AC_RING_INV;  /* Original ring value */
+    hbool_t reset_ring = FALSE;             /* Whether the ring was set */
+    herr_t ret_value = SUCCEED;             /* Return value */
+
+    FUNC_ENTER_NOAPI_TAG(dxpl_id, H5AC__FREESPACE_TAG, FAIL)
+
+    /* check args */
+    HDassert(f);
+    HDassert(f->shared);
+    HDassert(f->shared->lf);
+
+    /* Set the ring type in the DXPL.  In most cases, we will
+     * need H5AC_RING_RDFSM, so initialy set the ring in
+     * the DXPL to that value.  We will alter this later if
+     * needed.
+     */
+    if(H5AC_set_ring(dxpl_id, H5AC_RING_RDFSM, &dxpl, &orig_ring) < 0)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value")
+    reset_ring = TRUE;
+    curr_ring = H5AC_RING_RDFSM;
+
+    /* Determine start/end points for loop */
+    if(H5F_PAGED_AGGR(f)) {
+        start_type = H5F_MEM_PAGE_META;
+        end_type = H5F_MEM_PAGE_NTYPES;
+    } /* end if */
+    else {
+        start_type = (H5F_mem_page_t)H5FD_MEM_SUPER;
+        end_type = (H5F_mem_page_t)H5FD_MEM_NTYPES;
+    } /* end else */
+
+    for(tt = H5FD_MEM_SUPER; tt < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, tt))
+        if(HADDR_UNDEF == (fs_eoa[tt] = H5F_get_eoa(f, tt)))
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "driver get_eoa request failed")
+
+    if(!H5F_PAGED_AGGR(f)) {
+        /* Retrieve metadata aggregator info, if available */
+        if(H5MF_aggr_query(f, &(f->shared->meta_aggr), &ma_addr, &ma_size) < 0)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "can't query metadata aggregator stats")
+
+        /* Retrieve 'small data' aggregator info, if available */
+        if(H5MF_aggr_query(f, &(f->shared->sdata_aggr), &sda_addr, &sda_size) < 0)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "can't query small data aggregator stats")
+    } /* end if */
+
+    /* Iterate over all the free space types that have managers and get each free list's space */
+    for(type = start_type; type < end_type; H5_INC_ENUM(H5F_mem_page_t, type)) {
+        fs_started[type] = FALSE;
+
+        /* Check if the free space for the file has been initialized */
+        if(!f->shared->fs_man[type] && H5F_addr_defined(f->shared->fs_addr[type])) {
+            if(H5MF_open_fstype(f, dxpl_id, type) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't initialize file free space")
+            HDassert(f->shared->fs_man[type]);
+            fs_started[type] = TRUE;
+        } /* end if */
+
+        /* test to see if we need to switch rings -- do
+         * so if required
+         */
+        if(H5MF__fsm_type_is_self_referential(f, (H5F_mem_page_t)type))
+            needed_ring = H5AC_RING_MDFSM;
+        else
+            needed_ring = H5AC_RING_RDFSM;
+
+        if(needed_ring != curr_ring) {
+            if(H5AC_set_ring(dxpl_id, needed_ring, &dxpl, &curr_ring) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value")
+            curr_ring = needed_ring;
+        } /* end if */
+
+        /* Check if there's free space of this type */
+        if(f->shared->fs_man[type]) {
+            hsize_t type_fs_size = 0;    /* Amount of free space managed for each type */
+            hsize_t type_meta_size = 0;  /* Amount of free space metadata for each type */
+
+            /* Retrieve free space size from free space manager */
+            if(H5FS_sect_stats(f->shared->fs_man[type], &type_fs_size, NULL) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "can't query free space stats")
+            if(H5FS_size(f, f->shared->fs_man[type], &type_meta_size) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "can't query free space metadata stats")
+
+            /* Increment total free space for types */
+            tot_fs_size += type_fs_size;
+            tot_meta_size += type_meta_size;
+        } /* end if */
+    } /* end for */
+
+    /* Close the free-space managers if they were opened earlier in this routine */
+    for(type = start_type; type < end_type; H5_INC_ENUM(H5F_mem_page_t, type)) {
+        /* Test to see if we need to switch rings -- do so if required */
+        if(H5MF__fsm_type_is_self_referential(f, (H5F_mem_page_t)type))
+            needed_ring = H5AC_RING_MDFSM;
+        else
+            needed_ring = H5AC_RING_RDFSM;
+
+        if(needed_ring != curr_ring) {
+            if(H5AC_set_ring(dxpl_id, needed_ring, &dxpl, &curr_ring) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value")
+            curr_ring = needed_ring;
+        } /* end if */
+
+        if(fs_started[type])
+            if(H5MF__close_fstype(f, dxpl_id, type) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't close file free space")
+    } /* end for */
+
+    /* Set the value(s) to return */
+    /* (The metadata & small data aggregators count as free space now, since they aren't at EOA) */
+    if(tot_space)
+        *tot_space = tot_fs_size + ma_size + sda_size;
+    if(meta_size)
+        *meta_size = tot_meta_size;
+
+done:
+    /* Reset the ring in the DXPL */
+    if(reset_ring)
+        if(H5AC_reset_ring(dxpl, orig_ring) < 0)
+            HDONE_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set property value")
+
+    FUNC_LEAVE_NOAPI_TAG(ret_value, FAIL)
+} /* end H5MF_get_freespace() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5MF_get_free_sections()
+ *
+ * Purpose: 	To retrieve free-space section information for
+ *              paged or non-paged aggregation
+ *
+ * Return:      SUCCEED/FAIL
+ *
+ * Programmer:  Vailin Choi; Dec 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+ssize_t
+H5MF_get_free_sections(H5F_t *f, hid_t dxpl_id, H5FD_mem_t type, size_t nsects, H5F_sect_info_t *sect_info)
+{
+    H5P_genplist_t *dxpl = NULL;                /* DXPL for setting ring */
+    H5AC_ring_t curr_ring = H5AC_RING_INV;      /* Current ring value */
+    H5AC_ring_t needed_ring = H5AC_RING_INV;    /* Ring value needed for this iteration.  */
+    H5AC_ring_t orig_ring = H5AC_RING_INV;      /* Original ring value */
+    size_t total_sects = 0;                     /* Total number of sections */
+    H5MF_sect_iter_ud_t sect_udata;             /* User data for callback */
+    H5F_mem_page_t start_type, end_type;        /* Memory types to iterate over */
+    H5F_mem_page_t ty;                          /* Memory type for iteration */
+    hbool_t reset_ring = FALSE;                 /* Whether the ring was set */
+    ssize_t ret_value = -1;                     /* Return value */
+
+    FUNC_ENTER_NOAPI_TAG(dxpl_id, H5AC__FREESPACE_TAG, -1)
+
+    /* check args */
+    HDassert(f);
+    HDassert(f->shared);
+    HDassert(f->shared->lf);
+
+    /* H5MF_tidy_self_referential_fsm_hack() will fail if any self 
+     * referential FSM is opened prior to the call to it.  Thus call
+     * it here if necessary and if it hasn't been called already.
+     *
+     * The situation is further complicated if a cache image exists
+     * and had not yet been loaded into the metadata cache.  In this
+     * case, call H5AC_force_cache_image_load() instead of 
+     * H5MF_tidy_self_referential_fsm_hack().  H5AC_force_cache_image_load()
+     * will load the cache image, and then call 
+     * H5MF_tidy_self_referential_fsm_hack() to discard the cache image 
+     * block.
+     */
+    if(f->shared->first_alloc_dealloc) {
+        if(H5AC_cache_image_pending(f)) {
+            if(H5AC_force_cache_image_load(f, dxpl_id) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, FAIL, "forced cache image load failed")
+        } /* end if */
+        else {
+            if(H5MF_tidy_self_referential_fsm_hack(f, dxpl_id) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, FAIL, "tidy of self referential fsm hack failed")
+        } /* end else */
+    } /* end if */
+
+    if(type == H5FD_MEM_DEFAULT) {
+        start_type = H5F_MEM_PAGE_SUPER;
+        end_type = H5F_MEM_PAGE_NTYPES;
+    } /* end if */
+    else {
+        start_type = end_type = (H5F_mem_page_t)type;
+        if(H5F_PAGED_AGGR(f)) /* set to the corresponding LARGE free-space manager */
+            end_type = (H5F_mem_page_t)(end_type + H5FD_MEM_NTYPES);
+        else
+            H5_INC_ENUM(H5F_mem_page_t, end_type);
+    } /* end else */
+
+    /* Set up user data for section iteration */
+    sect_udata.sects = sect_info;
+    sect_udata.sect_count = nsects;
+    sect_udata.sect_idx = 0;
+
+    /* Set the ring type in the DXPL.  In most cases, we will
+     * need H5AC_RING_RDFSM, so initialy set the ring in
+     * the DXPL to that value.  We will alter this later if
+     * needed.
+     */
+    if(H5AC_set_ring(dxpl_id, H5AC_RING_RDFSM, &dxpl, &orig_ring) < 0)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value(0)")
+    reset_ring = TRUE;
+    curr_ring = H5AC_RING_RDFSM;
+
+    /* Iterate over memory types, retrieving the number of sections of each type */
+    for(ty = start_type; ty < end_type; H5_INC_ENUM(H5F_mem_page_t, ty)) {
+        hbool_t fs_started = FALSE;	/* The free-space manager is opened or not */
+        size_t nums = 0;		/* The number of free-space sections */
+
+        /* Test to see if we need to switch rings -- do so if required */
+        if(H5MF__fsm_type_is_self_referential(f, ty))
+            needed_ring = H5AC_RING_MDFSM;
+        else
+            needed_ring = H5AC_RING_RDFSM;
+
+        if(needed_ring != curr_ring) {
+            if(H5AC_set_ring(dxpl_id, needed_ring, &dxpl, &curr_ring) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value (1)")
+            curr_ring = needed_ring;
+        } /* end if */
+
+        if(!f->shared->fs_man[ty] && H5F_addr_defined(f->shared->fs_addr[ty])) {
+            if(H5MF_open_fstype(f, dxpl_id, ty) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't open the free space manager")
+            HDassert(f->shared->fs_man[ty]);
+            fs_started = TRUE;
+        } /* end if */
+
+        /* Check if there's free space sections of this type */
+        if(f->shared->fs_man[ty])
+            if(H5MF__get_free_sects(f, dxpl_id, f->shared->fs_man[ty], &sect_udata, &nums) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't get section info for the free space manager")
+
+        /* Increment total # of sections */
+        total_sects += nums;
+
+        /* Close the free space manager of this type, if we started it here */
+        if(fs_started)
+            if(H5MF__close_fstype(f, dxpl_id, ty) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTCLOSEOBJ, FAIL, "can't close file free space")
+        if((H5F_PAGED_AGGR(f)) && (type != H5FD_MEM_DEFAULT))
+            ty = (H5F_mem_page_t)(ty + H5FD_MEM_NTYPES - 2);
+    } /* end for */
+
+    /* Set return value */
+    ret_value = (ssize_t)total_sects;
+
+done:
+    /* Reset the ring in the DXPL */
+    if(reset_ring)
+        if(H5AC_reset_ring(dxpl, orig_ring) < 0)
+            HDONE_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set property value")
+
+    FUNC_LEAVE_NOAPI_TAG(ret_value, -1)
+} /* H5MF_get_free_sections() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5MF_sects_cb()
+ *
+ * Purpose:	Iterator callback for each free-space section
+ *          Retrieve address and size into user data
+ *
+ * Return:	Always succeed
+ *
+ * Programmer:  Vailin Choi
+ *              July 1st, 2009
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5MF_sects_cb(H5FS_section_info_t *_sect, void *_udata)
+{
+    H5MF_free_section_t *sect = (H5MF_free_section_t *)_sect;
+    H5MF_sect_iter_ud_t *udata = (H5MF_sect_iter_ud_t *)_udata;
+
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    if(udata->sect_idx < udata->sect_count) {
+        udata->sects[udata->sect_idx].addr = sect->sect_info.addr;
+        udata->sects[udata->sect_idx].size  = sect->sect_info.size;
+        udata->sect_idx++;
+    } /* end if */
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* H5MF_sects_cb() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5MF__get_free_sects
+ *
+ * Purpose:	Retrieve section information for the specified free-space manager.
+ *
+ * Return:      Success:        non-negative
+ *              Failure:        negative
+ *
+ * Programmer:  Vailin Choi; Dec 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5MF__get_free_sects(H5F_t *f, hid_t dxpl_id, H5FS_t *fspace, H5MF_sect_iter_ud_t *sect_udata, size_t *nums)
+{
+    hsize_t hnums = 0;          	/* # of sections */
+    herr_t ret_value = SUCCEED; 	/* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* check args */
+    HDassert(f);
+    HDassert(sect_udata);
+    HDassert(nums);
+    HDassert(fspace);
+
+    /* Query how many sections of this type */
+    if(H5FS_sect_stats(fspace, NULL, &hnums) < 0)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "can't query free space stats")
+    H5_CHECKED_ASSIGN(*nums, size_t, hnums, hsize_t);
+
+    /* Check if we should retrieve the section info */
+    if(sect_udata->sects && *nums > 0)
+        /* Iterate over all the free space sections of this type, adding them to the user's section info */
+        if(H5FS_sect_iterate(f, dxpl_id, fspace, H5MF_sects_cb, sect_udata) < 0)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_BADITER, FAIL, "can't iterate over sections")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5MF__get_free_sects() */
+
+
+/*-------------------------------------------------------------------------
  * Function:    H5MF_settle_raw_data_fsm()
  *
  * Purpose: 	Handle any tasks required before the metadata cache 
@@ -1253,19 +2662,48 @@ done:
  *		and any metadata free space managers that reside in the 
  *		raw data free space manager ring.
  *
- *		Specifically, any metadata managers that DON'T handle 
- *		space allocation for free space manager header or section
- *		info will reside in the raw data free space manager ring.
- *		As of this writing, the plan is to move to only two free space
- *		managers, one for raw data and one for metadata -- which
- *		means that only the raw data free space manager will reside
- *		in the free space manager ring.  However, this has not been
- *		fully implemented yet, so this code must support the 
- *		possibilty of multiple metadata free space managers, at most
- *		two of which handle free space manager header or section info,
- *		and thus reside in the metadata free space manager ring.
- *
- *		At present, the task list is:
+ *              Specifically, this means any metadata managers that DON'T 
+ *              handle space allocation for free space manager header or 
+ *              section info will reside in the raw data free space manager 
+ *              ring.
+ *
+ *              In the absence of page allocation, there is at most one 
+ *		free space manager per memory type defined in H5F_mem_t.
+ *		Of these, the one that allocates H5FD_MEM_DRAW will 
+ *		always reside in the raw data free space manager ring.
+ *		If there is more than one metadata free space manager, 
+ *		all that don't handle H5FD_MEM_FSPACE_HDR or 
+ *              H5FD_MEM_FSPACE_SINFO (which map to H5FD_MEM_OHDR and 
+ *              H5FD_MEM_LHEAP respectively) will reside in the raw 
+ *		data free space manager ring as well
+ *
+ *		With page allocation, the situation is conceptually 
+ *		identical, but more complex in practice.
+ *
+ *              In the worst case (multi file driver) page allocation 
+ *		can result in two free space managers for each memory 
+ *		type -- one for small (less than on equal to one page)
+ *              allocations, and one for large (greater than one page)
+ *              allocations.
+ *
+ *		In the more common one file case, page allocation will
+ *              result in a total of three free space managers -- one for 
+ *              small (<= one page) raw data allocations, one for small 
+ *              metadata allocations (i.e, all memory types other than 
+ *              H5FD_MEM_DRAW), and one for all large (> one page) 
+ *              allocations.
+ *
+ *              Despite these complications, the solution is the same in
+ *		the page allocation case -- free space managers (be they 
+ *              small data or large) are assigned to the raw data free 
+ *              space manager ring if they don't allocate file space for
+ *              free space managers.  Note that in the one file case, the 
+ *		large free space manager must be assigned to the metadata
+ *		free space manager ring, as it both allocates pages for 
+ *		the metadata free space manager, and allocates space for 
+ *		large (> 1 page) metadata cache entries.
+ *
+ *              At present, the task list for this routine is:
  *
  *		1) Reduce the EOA to the extent possible.  To do this:
  *
@@ -1320,26 +2758,43 @@ done:
 herr_t
 H5MF_settle_raw_data_fsm(H5F_t *f, hid_t dxpl_id, hbool_t *fsm_settled)
 {
+    int pass_count;
+    hsize_t alloc_size;
+    H5F_mem_t mem_type;                 /* Memory type for iteration */
+    H5F_mem_page_t fsm_type;            /* FSM type for iteration */
+    H5O_fsinfo_t fsinfo;                /* Free space manager info message */
+    H5FS_stat_t fs_stat;                /* Information for free-space manager */
     H5P_genplist_t *dxpl = NULL;        /* DXPL for setting ring */
     H5AC_ring_t orig_ring = H5AC_RING_INV;      /* Original ring value */
+    H5AC_ring_t curr_ring = H5AC_RING_INV;      /* Current ring value */
+    H5AC_ring_t needed_ring = H5AC_RING_INV;    /* Ring value needed for this iteration */
     hbool_t reset_ring = FALSE;         /* Whether the ring was set */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI_TAG(dxpl_id, H5AC__FREESPACE_TAG, FAIL)
 
-    /* check args */
+    /* Check args */
     HDassert(f);
     HDassert(f->shared);
     HDassert(fsm_settled);
 
-    /* Only need to settle things if we are persisting the free space info */
-    if(f->shared->fs_strategy == H5F_FILE_SPACE_ALL_PERSIST) {
-        H5O_fsinfo_t fsinfo;                    /* Free space manager info message */
-        H5FD_mem_t	type;			/* Memory type for iteration */
-        H5AC_ring_t curr_ring = H5AC_RING_INV;  /* Current ring value */
-        H5AC_ring_t needed_ring = H5AC_RING_INV; /* Ring value needed for this iteration  */
-        hbool_t fsm_opened[H5FD_MEM_NTYPES];    /* State of FSM */
-        hbool_t fsm_visited[H5FD_MEM_NTYPES];   /* State of FSM */
+    /* Only need to settle things if we are persisting the free space info 
+     * and allocation/deallocation has occurred.
+     */
+    if(f->shared->fs_persist && !f->shared->first_alloc_dealloc) {
+        hbool_t fsm_opened[H5F_MEM_PAGE_NTYPES];        /* State of FSM */
+        hbool_t fsm_visited[H5F_MEM_PAGE_NTYPES];       /* State of FSM */
+
+        /* Sanity check */
+        HDassert(f->shared->sblock);
+
+        /* should only be called if file is opened R/W */
+        HDassert(H5F_INTENT(f) & H5F_ACC_RDWR);
+
+        /* shouldn't be called unless we have a superblock supporting the
+         * superblock extension.
+         */
+        HDassert(f->shared->sblock->super_vers >= HDF5_SUPERBLOCK_VERSION_2);
 
         /* Initialize fsm_opened and fsm_visited */
         HDmemset(fsm_opened, 0, sizeof(fsm_opened));
@@ -1356,8 +2811,12 @@ H5MF_settle_raw_data_fsm(H5F_t *f, hid_t dxpl_id, hbool_t *fsm_settled)
          *
          * Note that while the raw data aggregator should not be restarted during
          * the close process, this need not be the case for the metadata aggregator.
+         *
+         * Note also that the aggregators will not exist if page aggregation 
+         * is enabled -- skip this if so.
          */
-        if(H5MF_free_aggrs(f, dxpl_id) < 0)
+        /* Vailin -- is this correct? */
+        if(!H5F_PAGED_AGGR(f) && (H5MF_free_aggrs(f, dxpl_id) < 0))
             HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, FAIL, "can't free aggregators")
 
         /* Set the ring type in the DXPL.  In most cases, we will
@@ -1379,7 +2838,7 @@ H5MF_settle_raw_data_fsm(H5F_t *f, hid_t dxpl_id, hbool_t *fsm_settled)
          * In the case of the raw data free space manager, and any other free
          * space manager that does not allocate space for free space managers,
          * allocations should be complete at this point, as all raw data should
-         * have space allocated and be flushed to file at this point.  Thus we
+         * have space allocated and be flushed to file by now.  Thus we
          * can examine such free space managers and only re-allocate space for
          * them if they contain free space.  Do this later in this function after
          * the EOA has been reduced to the extent possible.
@@ -1390,79 +2849,100 @@ H5MF_settle_raw_data_fsm(H5F_t *f, hid_t dxpl_id, hbool_t *fsm_settled)
          * are possible), the matter is more ticklish due to the self-
          * referential nature of the problem.  These FSMs are dealt with in
          * H5MF_settle_meta_data_fsm().
+         *
+         * Since paged allocation may be enabled, there may be up to two 
+         * free space managers per memory type -- one for small and one for
+         * large allocation.  Hence we must loop over the memory types twice
+         * setting the allocation size accordingly if paged allocation is 
+         * enabled.
          */
-        for(type = H5FD_MEM_SUPER; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type)) {
-            H5FS_stat_t fs_stat;        /* Information for free-space manager */
-            H5FD_mem_t  fsm_type;       /* File memory type for FSM */
-
-            /* There is potentially a many-to-one mapping from memory types to 
-             * free space managers.  Use the fsm_visited[] array to avoid visiting 
-             * a given FSM more than once.  Use fsm_opened[] to track which FSMs
-             * must be closed at the end of this function.
-             */
-            fsm_type = H5MF_ALLOC_TO_FS_TYPE(f, type);
-            if(!fsm_visited[fsm_type]) {
-                fsm_visited[fsm_type] = TRUE;
-
-                /* If there is no active FSM for this type, but such a FSM has
-                 * space allocated in file, open it so that we can free its file
-                 * space.
-                 */
-                if(NULL == f->shared->fs_man[fsm_type]) {
-                    if(H5F_addr_defined(f->shared->fs_addr[fsm_type])) {
-                        /* Sanity check */
-                        HDassert(fsm_opened[fsm_type] == FALSE);
-
-                        /* Start up FSM for the file memory type */
-                        if(H5MF__alloc_open(f, dxpl_id, fsm_type) < 0)
-                            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't initialize file free space manager")
-                        fsm_opened[fsm_type] = TRUE;
-                    } /* end if */
+        for(pass_count = 0; pass_count <= 1; pass_count++) {
+            if(pass_count == 0)
+                alloc_size = 1;
+            else if ( H5F_PAGED_AGGR(f) )
+                alloc_size = f->shared->fs_page_size + 1;
+            else /* no need for a second pass */
+                break;
+
+            for(mem_type = H5FD_MEM_SUPER; mem_type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5F_mem_t, mem_type)) {
+                H5MF_alloc_to_fs_type(f, mem_type, alloc_size, &fsm_type);
+
+                if(pass_count == 0) { /* this is the first pass */
+                    HDassert(fsm_type > H5F_MEM_PAGE_DEFAULT);
+                    HDassert(fsm_type < H5F_MEM_PAGE_LARGE_SUPER);
                 } /* end if */
+                else if(H5F_PAGED_AGGR(f)) { /* page alloc active */
+                    HDassert(fsm_type >= H5F_MEM_PAGE_LARGE_SUPER);
+                    HDassert(fsm_type < H5F_MEM_PAGE_NTYPES);
+                } /* end else-if */
+                else    /* paged allocation disabled -- should be unreachable */
+                    HDassert(FALSE);
+
+                if(!fsm_visited[fsm_type]) {
+                    fsm_visited[fsm_type] = TRUE;
+
+                    /* If there is no active FSM for this type, but such a FSM has
+                     * space allocated in file, open it so that we can free its file
+                     * space.
+                     */
+                    if(NULL == f->shared->fs_man[fsm_type]) {
+                        if(H5F_addr_defined(f->shared->fs_addr[fsm_type])) {
+                            /* Sanity check */
+                            HDassert(fsm_opened[fsm_type] == FALSE);
 
-                /* Check for an actual FSM for this type now */
-                /* (Possibly opened in previous step) */
-                if(f->shared->fs_man[fsm_type]) {
-                    /* Test to see if we need to switch rings -- do so if required */
-                    if((fsm_type == H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_HDR))
-                           || (fsm_type == H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_SINFO)))
-                        needed_ring = H5AC_RING_MDFSM;
-                    else
-                        needed_ring = H5AC_RING_RDFSM;
-                    if(needed_ring != curr_ring) {
-                        if(H5AC_set_ring(dxpl_id, needed_ring, &dxpl, &curr_ring) < 0)
-                            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value")
-                        curr_ring = needed_ring;
+                             if(H5MF_open_fstype(f, dxpl_id, fsm_type) < 0)
+                                 HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't initialize file free space manager")
+                            fsm_opened[fsm_type] = TRUE;
+                        } /* end if */
                     } /* end if */
 
-                    /* Query free space manager info for this type */
-                    if(H5FS_stat_info(f, f->shared->fs_man[fsm_type], &fs_stat) < 0)
-                        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't get free-space info")
+                    if(f->shared->fs_man[fsm_type]) {
+                        /* Test to see if we need to switch rings -- do so if required */
+                        if(H5MF__fsm_type_is_self_referential(f, fsm_type))
+                             needed_ring = H5AC_RING_MDFSM;
+                        else
+                             needed_ring = H5AC_RING_RDFSM;
+
+                        if(needed_ring != curr_ring) {
+                            if(H5AC_set_ring(dxpl_id, needed_ring, &dxpl, &curr_ring) < 0)
+                                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value")
+                            curr_ring = needed_ring;
+                        } /* end if */
 
-                    /* Check if the free space manager has space in the file */
-                    if(H5F_addr_defined(fs_stat.addr) || H5F_addr_defined(fs_stat.sect_addr)) {
-                        /* Delete the free space manager in the file.  Will 
-                         * reallocate later if the free space manager contains
-                         * any free space.
-                         */
-                        if(H5FS_free(f, f->shared->fs_man[fsm_type], dxpl_id) < 0)
-                            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't release free-space headers")
-                        f->shared->fs_addr[fsm_type] = HADDR_UNDEF;
+                        /* Query free space manager info for this type */
+                        if(H5FS_stat_info(f, f->shared->fs_man[fsm_type], &fs_stat) < 0)
+                            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't get free-space info")
+
+                        /* Check if the free space manager has space in the file */
+                        if(H5F_addr_defined(fs_stat.addr) || H5F_addr_defined(fs_stat.sect_addr)) {
+                            /* Delete the free space manager in the file.  Will 
+                             * reallocate later if the free space manager contains
+                             * any free space.
+                             */
+                            if(H5FS_free(f, f->shared->fs_man[fsm_type], dxpl_id, TRUE) < 0)
+                                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't release free-space headers")
+                            f->shared->fs_addr[fsm_type] = HADDR_UNDEF;
+                        } /* end if */
                     } /* end if */
-                } /* end if */
 
-                /* note that we are tracking opened FSM -- we will close them
-                 * at the end of the function.
-                 */
-            } /* end if */
+                    /* note that we are tracking opened FSM -- we will close them
+                     * at the end of the function.
+                     */
+                } /* end if */
+            } /* end for */
         } /* end for */
 
+
         /* c) Delete the free space manager superblock extension message
          *    if allocated.
          *
          *    Must do this since the routine that writes / creates superblock
          *    extension messages will choke if the target message is
          *    unexpectedly either absent or present.
+         *
+         *    Update: This is probably unecessary, as I gather that the 
+         *            file space manager info message is guaranteed to exist.
+         *            Leave it in for now, but consider removing it.
          */
         if(H5F_addr_defined(f->shared->sblock->ext_addr))
             if(H5F_super_ext_remove_msg(f, dxpl_id, H5O_FSINFO_ID) < 0)
@@ -1486,11 +2966,16 @@ H5MF_settle_raw_data_fsm(H5F_t *f, hid_t dxpl_id, hbool_t *fsm_settled)
          * those addresses are unknown.  This is OK -- we will write the correct
          * values to the message at free space manager shutdown.
          */
-        for(type = H5FD_MEM_SUPER; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type))
-            fsinfo.fs_addr[type - 1] = HADDR_UNDEF;
+        for(fsm_type = H5F_MEM_PAGE_SUPER; fsm_type < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, fsm_type))
+            fsinfo.fs_addr[fsm_type - 1] = HADDR_UNDEF;
         fsinfo.strategy = f->shared->fs_strategy;
+        fsinfo.persist = f->shared->fs_persist;
         fsinfo.threshold = f->shared->fs_threshold;
-        if(H5F_super_ext_write_msg(f, dxpl_id, H5O_FSINFO_ID, &fsinfo, TRUE, H5O_MSG_NO_FLAGS_SET) < 0)
+        fsinfo.page_size = f->shared->fs_page_size;
+        fsinfo.pgend_meta_thres = f->shared->pgend_meta_thres;
+        fsinfo.eoa_pre_fsm_fsalloc = HADDR_UNDEF;
+
+        if(H5F_super_ext_write_msg(f, dxpl_id, H5O_FSINFO_ID, &fsinfo, TRUE, H5O_MSG_FLAG_MARK_IF_UNKNOWN) < 0)
             HGOTO_ERROR(H5E_RESOURCE, H5E_WRITEERROR, FAIL, "error in writing fsinfo message to superblock extension")
 
 
@@ -1514,102 +2999,117 @@ H5MF_settle_raw_data_fsm(H5F_t *f, hid_t dxpl_id, hbool_t *fsm_settled)
          */
 
         /* Reinitialize fsm_visited */
-        HDmemset(fsm_visited, 0, sizeof(fsm_visited));
-
-        for(type = H5FD_MEM_SUPER; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type)) {
-            H5FD_mem_t  fsm_type;       /* File memory type for FSM */
-
-            fsm_type = H5MF_ALLOC_TO_FS_TYPE(f, type);
-
-            /* test to see if we need to switch rings -- do so if required */
-            if((fsm_type == H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_HDR))
-                    || (fsm_type == H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_SINFO)))
-                needed_ring = H5AC_RING_MDFSM;
-            else
-                needed_ring = H5AC_RING_RDFSM;
-
-            if(needed_ring != curr_ring) {
-                if(H5AC_set_ring(dxpl_id, needed_ring, &dxpl, &curr_ring)< 0)
-                    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value")
-                curr_ring = needed_ring;
-            } /* end if */
-
-            /* Since there can be a many-to-one mapping from memory types
-             * to free space managers, ensure that we don't visit any FSM
-             * more than once.
-             */
-            if(!fsm_visited[fsm_type]) {
-                fsm_visited[fsm_type] = TRUE;
-
-                if(f->shared->fs_man[fsm_type]) {
-                    /* Only allocate file space if the target free space manager 
-                     * doesn't allocate file space for free space managers.  Note 
-                     * that this is also the deciding factor as to whether a FSM 
-                     * in in the raw data FSM ring.
-                     */
-                    if((fsm_type != H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_HDR)) 
-                            && (fsm_type != H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_SINFO))) {
-                        H5FS_stat_t fs_stat;        /* Information for free-space manager */
+        for(fsm_type = H5F_MEM_PAGE_SUPER; fsm_type < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, fsm_type))
+            fsm_visited[fsm_type] = FALSE;
+
+        for(pass_count = 0; pass_count <= 1; pass_count++) {
+            if(pass_count == 0)
+                alloc_size = 1;
+            else if(H5F_PAGED_AGGR(f))
+                alloc_size = f->shared->fs_page_size + 1;
+            else /* no need for a second pass */
+                break;
+
+            for(mem_type = H5FD_MEM_SUPER; mem_type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5F_mem_t, mem_type)) {
+                H5MF_alloc_to_fs_type(f, mem_type, alloc_size, &fsm_type);
+
+                if(pass_count == 0) { /* this is the first pass */
+                    HDassert(fsm_type > H5F_MEM_PAGE_DEFAULT);
+                    HDassert(fsm_type < H5F_MEM_PAGE_LARGE_SUPER);
+                } /* end if */
+                else if(H5F_PAGED_AGGR(f)) { /* page alloc active */
+                    HDassert(fsm_type >= H5F_MEM_PAGE_LARGE_SUPER);
+                    HDassert(fsm_type < H5F_MEM_PAGE_NTYPES);
+                } /* end else-if */
+                else  /* paged allocation disabled -- should be unreachable */
+                    HDassert(FALSE);
 
-                        /* The current ring should be H5AC_RING_RDFSM */
-                        HDassert(curr_ring == H5AC_RING_RDFSM);
+                /* test to see if we need to switch rings -- do so if required */
+                if(H5MF__fsm_type_is_self_referential(f, fsm_type))
+                    needed_ring = H5AC_RING_MDFSM;
+                else
+                    needed_ring = H5AC_RING_RDFSM;
 
-                        /* Query free space manager info for this type */
-                        if(H5FS_stat_info(f, f->shared->fs_man[fsm_type], &fs_stat) < 0 )
-                            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "can't get free-space info")
+                if(needed_ring != curr_ring) {
+                    if(H5AC_set_ring(dxpl_id, needed_ring, &dxpl, &curr_ring)< 0)
+                        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value")
+                    curr_ring = needed_ring;
+                } /* end if */
 
-                        /* If the free space manager contains section info,
-                         * allocate space for the header and sinfo (note that
-                         * space must not be allocated at present -- verify
-                         * verify this with assertions).
+                /* Since there can be a many-to-one mapping from memory types
+                 * to free space managers, ensure that we don't visit any FSM
+                 * more than once.
+                 */
+                if(!fsm_visited[fsm_type]) {
+                    fsm_visited[fsm_type] = TRUE;
+
+                    if(f->shared->fs_man[fsm_type]) {
+                        /* Only allocate file space if the target free space manager 
+                         * doesn't allocate file space for free space managers.  Note 
+                         * that this is also the deciding factor as to whether a FSM 
+                         * in in the raw data FSM ring.
                          */
-                        if(fs_stat.serial_sect_count > 0) {
-                            /* Sanity check */
-                            HDassert(!H5F_addr_defined(fs_stat.addr));
-
-                            /* Allocate FSM header */
-                            if(H5FS_alloc_hdr(f, f->shared->fs_man[fsm_type], &f->shared->fs_addr[fsm_type], dxpl_id) < 0)
-                                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, FAIL, "can't allocated free-space header")
-
-                            /* Allocate FSM section info */
-                            HDassert(!H5F_addr_defined(fs_stat.sect_addr));
-                            HDassert(fs_stat.alloc_sect_size == 0);
-                            if(H5FS_alloc_sect(f, f->shared->fs_man[fsm_type], dxpl_id) < 0 )
-                                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, FAIL, "can't allocate free-space section info")
+                        if(!H5MF__fsm_type_is_self_referential(f, fsm_type)) {
+                            /* The current ring should be H5AC_RING_RDFSM */
+                            HDassert(curr_ring == H5AC_RING_RDFSM);
+
+                            /* Query free space manager info for this type */
+                            if(H5FS_stat_info(f, f->shared->fs_man[fsm_type], &fs_stat) < 0 )
+                                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "can't get free-space info")
+
+                            /* If the free space manager contains section info,
+                             * allocate space for the header and sinfo (note that
+                             * space must not be allocated at present -- verify
+                             * verify this with assertions).
+                             */
+                            if(fs_stat.serial_sect_count > 0) {
+                                /* Sanity check */
+                                HDassert(!H5F_addr_defined(fs_stat.addr));
+
+                                /* Allocate FSM header */
+                                if(H5FS_alloc_hdr(f, f->shared->fs_man[fsm_type], &f->shared->fs_addr[fsm_type], dxpl_id) < 0)
+                                    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, FAIL, "can't allocated free-space header")
+
+                                /* Allocate FSM section info */
+                                HDassert(!H5F_addr_defined(fs_stat.sect_addr));
+                                HDassert(fs_stat.alloc_sect_size == 0);
+                                if(H5FS_alloc_sect(f, f->shared->fs_man[fsm_type], dxpl_id) < 0 )
+                                    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, FAIL, "can't allocate free-space section info")
 
 #ifndef NDEBUG
-                            /* Re-Query free space manager info for this type */
-                            if(H5FS_stat_info(f, f->shared->fs_man[fsm_type], &fs_stat) < 0)
-                                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't get free-space info")
-
-                            HDassert(H5F_addr_defined(fs_stat.addr));
-                            HDassert(H5F_addr_defined(fs_stat.sect_addr));
-                            HDassert(fs_stat.serial_sect_count > 0);
-                            HDassert(fs_stat.alloc_sect_size > 0);
-                            HDassert(fs_stat.alloc_sect_size == fs_stat.sect_size);
+                                /* Re-Query free space manager info for this type */
+                                if(H5FS_stat_info(f, f->shared->fs_man[fsm_type], &fs_stat) < 0)
+                                    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't get free-space info")
+
+                                HDassert(H5F_addr_defined(fs_stat.addr));
+                                HDassert(H5F_addr_defined(fs_stat.sect_addr));
+                                HDassert(fs_stat.serial_sect_count > 0);
+                                HDassert(fs_stat.alloc_sect_size > 0);
+                                HDassert(fs_stat.alloc_sect_size == fs_stat.sect_size);
 #endif /* NDEBUG */
+                            } /* end if */
+                            else {
+                                HDassert(!H5F_addr_defined(fs_stat.addr));
+                                HDassert(!H5F_addr_defined(fs_stat.sect_addr));
+                                HDassert(fs_stat.serial_sect_count == 0);
+                                HDassert(fs_stat.alloc_sect_size == 0);
+                            } /* end else */
                         } /* end if */
-                        else {
-                            HDassert(!H5F_addr_defined(fs_stat.addr));
-                            HDassert(!H5F_addr_defined(fs_stat.sect_addr));
-                            HDassert(fs_stat.serial_sect_count == 0);
-                            HDassert(fs_stat.alloc_sect_size == 0);
-                        } /* end else */
                     } /* end if */
-                } /* end if */
 
-                /* Close any opened FSMs */
-                if(fsm_opened[fsm_type]) {
-                    if(H5MF__alloc_close(f, dxpl_id, fsm_type) < 0)
-                        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't close file free space manager")
-                    fsm_opened[fsm_type] = FALSE;
+                    /* Close any opened FSMs */
+                    if(fsm_opened[fsm_type]) {
+                        if(H5MF__close_fstype(f, dxpl_id, fsm_type) < 0)
+                            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't close file free space manager")
+                        fsm_opened[fsm_type] = FALSE;
+                    } /* end if */
                 } /* end if */
-            } /* end if */
+            } /* end for */
         } /* end for */
 
         /* verify that all opened FSMs were closed */
-        for(type = H5FD_MEM_SUPER; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type))
-            HDassert(!fsm_opened[type]);
+        for(fsm_type = H5F_MEM_PAGE_SUPER; fsm_type < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, fsm_type))
+            HDassert(!fsm_opened[fsm_type]);
 
         /* Indicate that the FSM was settled successfully */
         *fsm_settled = TRUE;
@@ -1630,11 +3130,11 @@ done:
  *
  * Purpose: 	If the free space manager is persistent, handle any tasks 
  *		required before the metadata cache can serialize or flush 
- *		the metadata free space manager(sI) that handle file space 
+ *		the metadata free space manager(s) that handle file space 
  *		allocation for free space managers.
  *
  *		In most cases, there will be only one manager assigned 
- *		to this role.  However, since for reason or reason unknown,
+ *		to this role.  However, since for reasons unknown,
  *		free space manager headers and section info blocks are 
  *		different classes of memory, it is possible that two free 
  *		space managers will be involved.
@@ -1642,7 +3142,7 @@ done:
  *		On entry to this function, the raw data settle routine
  *		(H5MF_settle_raw_data_fsm()) should have:
  *
- *		1) Freed the accumulators.
+ *              1) Freed the aggregators.
  *
  *		2) Freed all file space allocated to the free space managers.
  *
@@ -1678,9 +3178,12 @@ done:
  *		1) Verify that the free space manager(s) involved in file
  *		   space allocation for free space managers are still floating.
  *
- *		2) Free the accumulators.
+ *              2) Free the aggregators.
  *
- *		3) Reduce the EOA to the extent possible.
+ *              3) Reduce the EOA to the extent possible, and make note
+ *		   of the resulting value.  This value will be stored 
+ *		   in the fsinfo superblock extension message and be used
+ *                 in the subsequent file open.
  *
  *		4) Re-allocate space for any free space manager(s) that:
  *
@@ -1714,6 +3217,9 @@ done:
  *		   severe time pressure at the moment, the above brute 
  *		   force solution is attractive. 
  *
+ *              5) Make note of the EOA -- used for sanity checking on 
+ *                 FSM shutdown.
+ *
  * Return:	SUCCEED/FAIL
  *
  * Programmer:  John Mainzer
@@ -1724,10 +3230,23 @@ done:
 herr_t
 H5MF_settle_meta_data_fsm(H5F_t *f, hid_t dxpl_id, hbool_t *fsm_settled)
 {
+    H5F_mem_page_t sm_fshdr_fs_type;	/* small fs hdr fsm */
+    H5F_mem_page_t sm_fssinfo_fs_type;  /* small fs sinfo fsm */
+    H5F_mem_page_t lg_fshdr_fs_type;    /* large fs hdr fsm */
+    H5F_mem_page_t lg_fssinfo_fs_type;  /* large fs sinfo fsm */
+    H5FS_t     *sm_hdr_fspace = NULL;   /* ptr to sm FSM hdr alloc FSM */
+    H5FS_t     *sm_sinfo_fspace = NULL; /* ptr to sm FSM sinfo alloc FSM */
+    H5FS_t     *lg_hdr_fspace = NULL;   /* ptr to lg FSM hdr alloc FSM */
+    H5FS_t     *lg_sinfo_fspace = NULL; /* ptr to lg FSM sinfo alloc FSM */
+    haddr_t eoa_pre_fsm_fsalloc;        /* eoa pre file space allocation */
+                                        /* for self referential FSMs */
+    haddr_t eoa_post_fsm_fsalloc;       /* eoa post file space allocation */
+                                        /* for self referential FSMs */
+    H5FS_stat_t fs_stat;                /* Information for hdr FSM */
     H5P_genplist_t *dxpl = NULL;        /* DXPL for setting ring */
     H5AC_ring_t orig_ring = H5AC_RING_INV; /* Original ring value */
     hbool_t	reset_ring = FALSE;     /* Whether we set the ring */
-    herr_t 	ret_value = SUCCEED;        /* Return value */
+    herr_t 	ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_NOAPI_TAG(dxpl_id, H5AC__FREESPACE_TAG, FAIL)
 
@@ -1736,29 +3255,49 @@ H5MF_settle_meta_data_fsm(H5F_t *f, hid_t dxpl_id, hbool_t *fsm_settled)
     HDassert(f->shared);
     HDassert(fsm_settled);
 
-    /* Only need to settle things if we are persisting the free space info */
-    if(f->shared->fs_strategy == H5F_FILE_SPACE_ALL_PERSIST) {
-        H5FS_t     *hdr_fspace;             /* Ptr to FSM hdr alloc FSM */
-        H5FS_t     *sinfo_fspace;           /* Ptr to FSM sinfo alloc FSM */
-        H5FS_stat_t fs_stat;		    /* Information for FSM */
-        H5FD_mem_t  hdr_fsm_alloc_type;	    /* FSM hdr alloc type */
-        H5FD_mem_t  sinfo_fsm_alloc_type;   /* FSM info alloc type */
-
-        /* Get the file memory types for the FSM header & section info */
-        hdr_fsm_alloc_type = H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_HDR);
-        sinfo_fsm_alloc_type = H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_SINFO);
-
-        /* Sanity checks */
-        HDassert(hdr_fsm_alloc_type > H5FD_MEM_NOLIST);
-        HDassert(hdr_fsm_alloc_type < H5FD_MEM_NTYPES);
-        HDassert(sinfo_fsm_alloc_type > H5FD_MEM_NOLIST);
-        HDassert(sinfo_fsm_alloc_type < H5FD_MEM_NTYPES);
-        HDassert(!H5F_addr_defined(f->shared->fs_addr[hdr_fsm_alloc_type]));
-        HDassert(!H5F_addr_defined(f->shared->fs_addr[sinfo_fsm_alloc_type]));
-
-        /* Note that in most cases, hdr_fspace will equal sinfo_fspace. */
-        hdr_fspace = f->shared->fs_man[hdr_fsm_alloc_type];
-        sinfo_fspace = f->shared->fs_man[sinfo_fsm_alloc_type];
+    /* Only need to settle things if we are persisting the free space info 
+     * and allocation/deallocation has occurred.
+     */
+    if(f->shared->fs_persist && !f->shared->first_alloc_dealloc) {
+        /* Sanity check */
+        HDassert(f->shared->lf);
+
+        /* should only be called if file is opened R/W */
+        HDassert(H5F_INTENT(f) & H5F_ACC_RDWR);
+
+        H5MF_alloc_to_fs_type(f, H5FD_MEM_FSPACE_HDR, (size_t)1, &sm_fshdr_fs_type);
+        H5MF_alloc_to_fs_type(f, H5FD_MEM_FSPACE_SINFO, (size_t)1, &sm_fssinfo_fs_type);
+
+        HDassert(sm_fshdr_fs_type > H5F_MEM_PAGE_DEFAULT);
+        HDassert(sm_fshdr_fs_type < H5F_MEM_PAGE_LARGE_SUPER);
+
+        HDassert(sm_fssinfo_fs_type > H5F_MEM_PAGE_DEFAULT);
+        HDassert(sm_fssinfo_fs_type < H5F_MEM_PAGE_LARGE_SUPER);
+
+        HDassert(!H5F_addr_defined(f->shared->fs_addr[sm_fshdr_fs_type]));
+        HDassert(!H5F_addr_defined(f->shared->fs_addr[sm_fssinfo_fs_type]));
+
+        /* Note that in most cases, sm_hdr_fspace will equal sm_sinfo_fspace. */
+        sm_hdr_fspace = f->shared->fs_man[sm_fshdr_fs_type];
+        sm_sinfo_fspace = f->shared->fs_man[sm_fssinfo_fs_type];
+
+        if(H5F_PAGED_AGGR(f)) {
+            H5MF_alloc_to_fs_type(f, H5FD_MEM_FSPACE_HDR, f->shared->fs_page_size + 1, &lg_fshdr_fs_type);
+            H5MF_alloc_to_fs_type(f, H5FD_MEM_FSPACE_SINFO, f->shared->fs_page_size + 1, &lg_fssinfo_fs_type);
+
+            HDassert(lg_fshdr_fs_type >= H5F_MEM_PAGE_LARGE_SUPER);
+            HDassert(lg_fshdr_fs_type < H5F_MEM_PAGE_NTYPES);
+
+            HDassert(lg_fssinfo_fs_type >= H5F_MEM_PAGE_LARGE_SUPER);
+            HDassert(lg_fssinfo_fs_type < H5F_MEM_PAGE_NTYPES);
+
+            HDassert(!H5F_addr_defined(f->shared->fs_addr[lg_fshdr_fs_type]));
+            HDassert(!H5F_addr_defined(f->shared->fs_addr[lg_fssinfo_fs_type]));
+
+            /* Note that in most cases, lg_hdr_fspace will equal lg_sinfo_fspace. */
+            lg_hdr_fspace = f->shared->fs_man[lg_fshdr_fs_type];
+            lg_sinfo_fspace = f->shared->fs_man[lg_fssinfo_fs_type];
+        } /* end if */
 
         /* Set the ring in the dxpl appropriately for subsequent calls */
         if(H5AC_set_ring(dxpl_id, H5AC_RING_MDFSM, &dxpl, &orig_ring) < 0)
@@ -1766,41 +3305,109 @@ H5MF_settle_meta_data_fsm(H5F_t *f, hid_t dxpl_id, hbool_t *fsm_settled)
         reset_ring = TRUE;
 
 #ifndef NDEBUG
-        /* Verify that hdr_fspace is floating if it exists */
-        if(hdr_fspace) {
+        /* Verify that sm_hdr_fspace is floating if it exists */
+        if(sm_hdr_fspace) {
             /* Query free space manager info for this type */
-            if(H5FS_stat_info(f, hdr_fspace, &fs_stat) < 0)
-                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "can't get free-space info")
+            if(H5FS_stat_info(f, sm_hdr_fspace, &fs_stat) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL,  "can't get free-space info")
 
             HDassert(!H5F_addr_defined(fs_stat.addr));
             HDassert(!H5F_addr_defined(fs_stat.sect_addr));
             HDassert(fs_stat.alloc_sect_size == 0);
         } /* end if */
 
-        /* Verify that sinfo_fspace is floating if it exists */
-        if((sinfo_fspace) && (hdr_fspace != sinfo_fspace)) {
+        /* Verify that sm_sinfo_fspace is floating if it exists and is distinct */
+        if((sm_sinfo_fspace) && (sm_hdr_fspace != sm_sinfo_fspace)) {
             /* Query free space manager info for this type */
-            if(H5FS_stat_info(f, sinfo_fspace, &fs_stat) < 0)
+            if(H5FS_stat_info(f, sm_sinfo_fspace, &fs_stat) < 0)
                 HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "can't get free-space info")
 
             HDassert(!H5F_addr_defined(fs_stat.addr));
             HDassert(!H5F_addr_defined(fs_stat.sect_addr));
             HDassert(fs_stat.alloc_sect_size == 0);
         } /* end if */
+
+        if(H5F_PAGED_AGGR(f)) {
+            /* Verify that lg_hdr_fspace is floating if it exists */
+            if(lg_hdr_fspace) {
+                /* Query free space manager info for this type */
+                if(H5FS_stat_info(f, lg_hdr_fspace, &fs_stat) < 0)
+                    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "can't get free-space info (3)")
+
+                HDassert(!H5F_addr_defined(fs_stat.addr));
+                HDassert(!H5F_addr_defined(fs_stat.sect_addr));
+                HDassert(fs_stat.alloc_sect_size == 0);
+            } /* end if */
+
+            /* Verify that lg_sinfo_fspace is floating if it 
+             * exists and is distinct 
+             */
+            if((lg_sinfo_fspace) && (lg_hdr_fspace != lg_sinfo_fspace)) {
+                /* Query free space manager info for this type */
+                if(H5FS_stat_info(f, lg_sinfo_fspace, &fs_stat) < 0)
+                    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "can't get free-space info (4)")
+
+                HDassert(!H5F_addr_defined(fs_stat.addr));
+                HDassert(!H5F_addr_defined(fs_stat.sect_addr));
+                HDassert(fs_stat.alloc_sect_size == 0);
+            } /* end if */
+        } /* end if */
 #endif /* NDEBUG */
 
         /* Free the space in the metadata aggregator.  Do this via the
          * H5MF_free_aggrs() call.  Note that the raw data aggregator must
          * have already been freed.  Sanity checks for this?
+         *
+         * Note that the aggregators will not exist if paged aggregation 
+         * is enabled -- don't attempt to free if this is the case.
          */
+        /* Vailin -- is this correct? */
         /* (for space not at EOF, it may be put into free space managers) */
-        if(H5MF_free_aggrs(f, dxpl_id) < 0)
+        if((!H5F_PAGED_AGGR(f)) && (H5MF_free_aggrs(f, dxpl_id) < 0))
             HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, FAIL, "can't free aggregators")
 
         /* Trying shrinking the EOA for the file */
         if(H5MF__close_shrink_eoa(f, dxpl_id) < 0)
             HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSHRINK, FAIL, "can't shrink eoa")
 
+        /* At this point, the EOA should be set to a value that contains 
+         * the allocation for all user data, all non self referential FSMs,
+         * the superblock and all superblock extension messages.
+         * 
+         * Make note of the current EOA.  We will store this value in the 
+         * free space manager superblock extension message.  Since space for
+         * everything other than the self referential FSMs (and possibly the
+         * cache image) has been allocated at this point, this allows us to 
+         * to float the self referential FSMs on the first file space allocation / 
+         * deallocaiton and then set the EOA to this value before we handle
+         * the allocation / deallocation. (If a cache image exists, the 
+         * first allocation / deallocation will be the deallocation of space
+         * for the cache image).   
+         *
+         * WARNING:  This approach settling the self referential free space 
+         *           managers and allocating space for them in the file will 
+         *           not work as currently implemented with the split and 
+         *           multi file drivers, as the self referential free space 
+         *           manager header and section info can be stored in up to 
+         *           two different files -- requiring that up to two EOA's 
+         *           be stored in the the free space managers super block 
+         *           extension message.  
+         *
+         *           As of this writing, we are solving this problem by 
+         *           simply not supporting persistant FSMs with the split 
+         *           and multi file drivers.
+         *
+         *           Current plans are to do away with the multi file 
+         *           driver, so this should be a non-issue in this case.
+         *
+         *           We should be able to support the split file driver 
+         *           without a file format change.  However, the code to 
+         *           do so does not exist at present.
+         */
+         if(HADDR_UNDEF == (eoa_pre_fsm_fsalloc = H5FD_get_eoa(f->shared->lf, H5FD_MEM_DEFAULT)))
+            HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "unable to get EOA")
+
+
         /* ******************* PROBLEM: ********************
          *
          * If the file has an alignement other than 1, and if
@@ -1849,15 +3456,39 @@ H5MF_settle_meta_data_fsm(H5F_t *f, hid_t dxpl_id, hbool_t *fsm_settled)
          * This is isn't good, but due to schedule pressure, we will just drop
          * the fragment on the floor for now.
          */
-        if(hdr_fspace)
-            if(H5FS_alloc_vfd_alloc_hdr_and_section_info(f, dxpl_id, hdr_fspace,
-                    &(f->shared->fs_addr[hdr_fsm_alloc_type])) < 0)
-                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, FAIL, "can't vfd allocate hdr FSM file space")
+        if(sm_hdr_fspace)
+            if(H5FS_vfd_alloc_hdr_and_section_info_if_needed(f, dxpl_id, sm_hdr_fspace, &(f->shared->fs_addr[sm_fshdr_fs_type])) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, FAIL, "can't vfd allocate sm hdr FSM file space")
+
+        if(sm_sinfo_fspace && (sm_sinfo_fspace != sm_hdr_fspace))
+            if(H5FS_vfd_alloc_hdr_and_section_info_if_needed(f, dxpl_id, sm_sinfo_fspace, &(f->shared->fs_addr[sm_fssinfo_fs_type])) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, FAIL, "can't vfd allocate sm sinfo FSM file space")
+
+        if(H5F_PAGED_AGGR(f)) {
+            if(lg_hdr_fspace)
+                if(H5FS_vfd_alloc_hdr_and_section_info_if_needed(f, dxpl_id, lg_hdr_fspace, &(f->shared->fs_addr[lg_fshdr_fs_type])) < 0)
+                    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, FAIL, "can't vfd allocate lg hdr FSM file space")
+
+            if(lg_sinfo_fspace && (lg_sinfo_fspace != lg_hdr_fspace))
+                if(H5FS_vfd_alloc_hdr_and_section_info_if_needed(f, dxpl_id, lg_sinfo_fspace, &(f->shared->fs_addr[lg_fssinfo_fs_type])) < 0)
+                    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, FAIL, "can't vfd allocate lg sinfo FSM file space")
+        } /* end if */
 
-        if(sinfo_fspace && (sinfo_fspace != hdr_fspace))
-            if(H5FS_alloc_vfd_alloc_hdr_and_section_info(f, dxpl_id, sinfo_fspace,
-                    &(f->shared->fs_addr[sinfo_fsm_alloc_type])) < 0)
-                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, FAIL, "can't vfd allocate sinfo FSM file space")
+        /* Get the eoa after allocation of file space for the self referential
+         * free space managers.  Assuming no cache image, this should be the 
+         * final EOA of the file.
+         */
+        if(HADDR_UNDEF == (eoa_post_fsm_fsalloc = H5FD_get_eoa(f->shared->lf, H5FD_MEM_DEFAULT)))
+            HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "unable to get file size")
+
+        /* All free space managers should have file space allocated for them
+         * now, and should see no further allocations / deallocations.  Store
+         * the pre and post file space allocaton for self referential FSMs EOA
+         * for use when we actually write the free space manager superblock 
+         * extension message.
+         */
+        f->shared->eoa_pre_fsm_fsalloc  = eoa_pre_fsm_fsalloc;
+        f->shared->eoa_post_fsm_fsalloc = eoa_post_fsm_fsalloc;
 
         /* Indicate that the FSM was settled successfully */
         *fsm_settled = TRUE;
@@ -1868,479 +3499,410 @@ done:
         if(H5AC_reset_ring(dxpl, orig_ring) < 0)
             HDONE_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set property value")
 
-    FUNC_LEAVE_NOAPI(ret_value)
+    FUNC_LEAVE_NOAPI_TAG(ret_value, FAIL)
 } /* H5MF_settle_meta_data_fsm() */
 
 
 /*-------------------------------------------------------------------------
- * Function:    H5MF__close_delete
+ * Function:    H5MF__fsm_type_is_self_referential()
  *
- * Purpose:     Common code for closing and deleting freespace managers from
- *              the file.
+ * Purpose:     Return TRUE if the indicated free space manager allocates
+ *		file space for free space managers.  Return FALSE otherwise.
  *
- * Return:	SUCCEED/FAIL
+ * Return:      TRUE/FALSE
  *
- * Programmer:	Vailin Choi
- *              Jan 2016
+ * Programmer:  John Mainzer
+ *              12/6/16
  *
  *-------------------------------------------------------------------------
  */
-static herr_t
-H5MF__close_delete(H5F_t *f, hid_t dxpl_id, H5P_genplist_t **dxpl)
+hbool_t
+H5MF__fsm_type_is_self_referential(H5F_t *f, H5F_mem_page_t fsm_type)
 {
-    H5FD_mem_t type;                    /* Memory type for iteration */
-    H5AC_ring_t curr_ring = H5AC_RING_INV;      /* current ring value */
-    herr_t ret_value = SUCCEED;         /* Return value */
+    H5F_mem_page_t sm_fshdr_fsm;
+    H5F_mem_page_t sm_fssinfo_fsm;
+    H5F_mem_page_t lg_fshdr_fsm;
+    H5F_mem_page_t lg_fssinfo_fsm;
+    hbool_t result = FALSE;
 
-    FUNC_ENTER_STATIC_TAG(dxpl_id, H5AC__FREESPACE_TAG, FAIL)
-#ifdef H5MF_ALLOC_DEBUG
-HDfprintf(stderr, "%s: Entering\n", FUNC);
-#endif /* H5MF_ALLOC_DEBUG */
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
 
-    /* check args */
+    /* Sanity check */
     HDassert(f);
     HDassert(f->shared);
+    HDassert(fsm_type >= H5F_MEM_PAGE_DEFAULT);
+    HDassert(fsm_type < H5F_MEM_PAGE_NTYPES);
 
-    /* Iterate over all the free space types that have managers and get each free list's space */
-    for(type = H5FD_MEM_DEFAULT; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type)) {
-        H5AC_ring_t needed_ring;        /* Ring value needed for this iteration */
+    H5MF_alloc_to_fs_type(f, H5FD_MEM_FSPACE_HDR, (size_t)1, &sm_fshdr_fsm);
+    H5MF_alloc_to_fs_type(f, H5FD_MEM_FSPACE_SINFO, (size_t)1, &sm_fssinfo_fsm);
 
-#ifdef H5MF_ALLOC_DEBUG_MORE
-HDfprintf(stderr, "%s: Check 1.0 - f->shared->fs_man[%u] = %p, f->shared->fs_addr[%u] = %a\n", FUNC, (unsigned)type, f->shared->fs_man[type], (unsigned)type, f->shared->fs_addr[type]);
-#endif /* H5MF_ALLOC_DEBUG_MORE */
+    if(H5F_PAGED_AGGR(f)) {
+        H5MF_alloc_to_fs_type(f, H5FD_MEM_FSPACE_HDR, f->shared->fs_page_size + 1, &lg_fshdr_fsm);
+        H5MF_alloc_to_fs_type(f, H5FD_MEM_FSPACE_SINFO, f->shared->fs_page_size + 1, &lg_fssinfo_fsm);
 
-        /* test to see if we need to switch rings -- do so if required */
-        if((H5MF_ALLOC_TO_FS_TYPE(f, type) == H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_HDR))
-                || (H5MF_ALLOC_TO_FS_TYPE(f, type) == H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_SINFO)))
-            needed_ring = H5AC_RING_MDFSM;
+        result = (fsm_type == sm_fshdr_fsm) || (fsm_type == sm_fssinfo_fsm)
+                || (fsm_type == lg_fshdr_fsm) || (fsm_type == lg_fssinfo_fsm);
+    } /* end if */
+    else {
+        /* In principle, fsm_type should always be less than 
+         * H5F_MEM_PAGE_LARGE_SUPER whenever paged aggregation
+         * is not enabled.  However, since there is code that does
+         * not observe this prinicple, force the result to FALSE if
+         * fsm_type is greater than or equal to H5F_MEM_PAGE_LARGE_SUPER.
+         */
+        if(fsm_type >= H5F_MEM_PAGE_LARGE_SUPER)
+            result = FALSE;
         else
-            needed_ring = H5AC_RING_RDFSM;
-
-        if(needed_ring != curr_ring) {
-            if(H5AC_set_ring(dxpl_id, needed_ring, dxpl, &curr_ring) < 0)
-                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value (4)")
-            curr_ring = needed_ring;
-        } /* end if */
-
-        /* If the free space manager for this type is open, close it */
-        if(f->shared->fs_man[type]) {
-#ifdef H5MF_ALLOC_DEBUG_MORE
-HDfprintf(stderr, "%s: Before closing free space manager\n", FUNC);
-#endif /* H5MF_ALLOC_DEBUG_MORE */
-            if(H5FS_close(f, dxpl_id, f->shared->fs_man[type]) < 0)
-                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't release free space info")
-            f->shared->fs_man[type] = NULL;
-            f->shared->fs_state[type] = H5F_FS_STATE_CLOSED;
-        } /* end if */
-#ifdef H5MF_ALLOC_DEBUG_MORE
-HDfprintf(stderr, "%s: Check 2.0 - f->shared->fs_man[%u] = %p, f->shared->fs_addr[%u] = %a\n", FUNC, (unsigned)type, f->shared->fs_man[type], (unsigned)type, f->shared->fs_addr[type]);
-#endif /* H5MF_ALLOC_DEBUG_MORE */
-
-        /* If there is free space manager info for this type, delete it */
-        if(H5F_addr_defined(f->shared->fs_addr[type])) {
-            haddr_t tmp_fs_addr;            /* Temporary holder for free space manager address */
-
-            /* Put address into temporary variable and reset it */
-            /* (Avoids loopback in file space freeing routine) */
-            tmp_fs_addr = f->shared->fs_addr[type];
-            f->shared->fs_addr[type] = HADDR_UNDEF;
-
-            /* Shift to "deleting" state, to make certain we don't track any
-             *  file space freed as a result of deleting the free space manager.
-             */
-            f->shared->fs_state[type] = H5F_FS_STATE_DELETING;
-
-#ifdef H5MF_ALLOC_DEBUG_MORE
-HDfprintf(stderr, "%s: Before deleting free space manager\n", FUNC);
-#endif /* H5MF_ALLOC_DEBUG_MORE */
-
-            /* Delete free space manager for this type */
-            if(H5FS_delete(f, dxpl_id, tmp_fs_addr) < 0)
-                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, FAIL, "can't delete free space manager")
-
-            /* Shift [back] to closed state */
-            HDassert(f->shared->fs_state[type] == H5F_FS_STATE_DELETING);
-            f->shared->fs_state[type] = H5F_FS_STATE_CLOSED;
-
-            /* Sanity check that the free space manager for this type wasn't started up again */
-            HDassert(!H5F_addr_defined(f->shared->fs_addr[type]));
-        } /* end if */
-    } /* end for */
+            result = (fsm_type == sm_fshdr_fsm) || (fsm_type == sm_fssinfo_fsm);
+    } /* end else */
 
-done:
-#ifdef H5MF_ALLOC_DEBUG
-HDfprintf(stderr, "%s: Leaving\n", FUNC);
-#endif /* H5MF_ALLOC_DEBUG */
-    FUNC_LEAVE_NOAPI_TAG(ret_value, FAIL)
-} /* H5MF__close_delete() */
+    FUNC_LEAVE_NOAPI(result)
+} /* H5MF__fsm_type_is_self_referential() */
 
 
 /*-------------------------------------------------------------------------
- * Function:    H5MF_try_close
+ * Function:    H5MF__fsm_is_self_referential()
  *
- * Purpose:     This is called by H5Fformat_convert() to close and delete
- *		free-space managers when downgrading persistent free-space
- *		to non-persistent.
+ * Purpose:     Return TRUE if the indicated free space manager allocates
+ *		file space for free space managers.  Return FALSE otherwise.
  *
- * Return:	SUCCEED/FAIL
+ * Return:      TRUE/FALSE
  *
- * Programmer:	Vailin Choi
- *              Jan 2016
+ * Programmer:  John Mainzer
+ *              12/6/16
  *
  *-------------------------------------------------------------------------
  */
-herr_t
-H5MF_try_close(H5F_t *f, hid_t dxpl_id)
+static hbool_t
+H5MF__fsm_is_self_referential(H5F_t *f, H5FS_t *fspace)
 {
-    H5P_genplist_t *dxpl = NULL;        /* DXPL for setting ring */
-    H5AC_ring_t orig_ring = H5AC_RING_INV;      /* Original ring value */
-    hbool_t reset_ring = FALSE;         /* Whether the ring was set */
-    herr_t ret_value = SUCCEED;         /* Return value */
+    H5F_mem_page_t sm_fshdr_fsm;
+    H5F_mem_page_t sm_fssinfo_fsm;
+    hbool_t result = FALSE;
 
-    FUNC_ENTER_NOAPI(FAIL)
-#ifdef H5MF_ALLOC_DEBUG
-HDfprintf(stderr, "%s: Entering\n", FUNC);
-#endif /* H5MF_ALLOC_DEBUG */
+    FUNC_ENTER_STATIC_NOERR
 
-    /* check args */
+    /* Sanity check */
     HDassert(f);
+    HDassert(f->shared);
+    HDassert(fspace);
 
-    /* Set the ring type in the DXPL */
-    if(H5AC_set_ring(dxpl_id, H5AC_RING_RDFSM, &dxpl, &orig_ring) < 0)
-        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value")
-    reset_ring = TRUE;
+    H5MF_alloc_to_fs_type(f, H5FD_MEM_FSPACE_HDR, (size_t)1, &sm_fshdr_fsm);
+    H5MF_alloc_to_fs_type(f, H5FD_MEM_FSPACE_SINFO, (size_t)1, &sm_fssinfo_fsm);
 
-    /* Close and delete freespace managers from the file */
-    if(H5MF__close_delete(f, dxpl_id, &dxpl) < 0)
-        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to close delete free-space managers")
+    if(H5F_PAGED_AGGR(f)) {
+        H5F_mem_page_t lg_fshdr_fsm;
+        H5F_mem_page_t lg_fssinfo_fsm;
 
-done:
-    /* Reset the ring in the DXPL */
-    if(reset_ring)
-        if(H5AC_reset_ring(dxpl, orig_ring) < 0)
-            HDONE_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set property value")
+        H5MF_alloc_to_fs_type(f, H5FD_MEM_FSPACE_HDR, f->shared->fs_page_size + 1, &lg_fshdr_fsm);
+        H5MF_alloc_to_fs_type(f, H5FD_MEM_FSPACE_SINFO, f->shared->fs_page_size + 1, &lg_fssinfo_fsm);
 
-#ifdef H5MF_ALLOC_DEBUG
-HDfprintf(stderr, "%s: Leaving\n", FUNC);
-#endif /* H5MF_ALLOC_DEBUG */
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* H5MF_try_close() */
+        result = (fspace == f->shared->fs_man[sm_fshdr_fsm]) ||
+                   (fspace == f->shared->fs_man[sm_fssinfo_fsm]) ||
+                   (fspace == f->shared->fs_man[lg_fshdr_fsm]) ||
+                   (fspace == f->shared->fs_man[lg_fssinfo_fsm]);
+    } /* end if */
+    else
+        result = (fspace == f->shared->fs_man[sm_fshdr_fsm]) ||
+                   (fspace == f->shared->fs_man[sm_fssinfo_fsm]);
+
+    FUNC_LEAVE_NOAPI(result)
+} /* H5MF__fsm_is_self_referential() */
 
 
 /*-------------------------------------------------------------------------
- * Function:    H5MF_close
- *
- * Purpose:     Close the free space tracker(s) for a file
- *
- * Return:	SUCCEED/FAIL
+ * Function:    H5MF_tidy_self_referential_fsm_hack
+ *
+ * Purpose:     As discussed in the comments of the settle routines above,
+ *		the existence of self referential free space managers
+ *		as currently implemented creates the possibility of 
+ *		infinite loops at file close.
+ *
+ *		As a hack to avoid this, we have added code to settle
+ *		self referential free space managers, and then allocate 
+ *		space for them directly from the file driver.
+ *
+ *		To avoid dropping ever increasing amounts of file space 
+ *              on the floor with each subsequent file close/open cycle,
+ *              we need to clean this up on file open.  To avoid this,
+ *              this function is called on the first file space allocation
+ *              or deallocation after file open to float the self referential
+ *              free space managers and reduce the EOA to the value it 
+ *              had before the direct allocation of space for the self 
+ *              referential free space managers.
+ *
+ *              The function proceeds as follows:
+ *
+ *              1) Verify that f->shared->first_alloc_dealloc is TRUE, 
+ *                 and then set it to FALSE.
+ *
+ *              2) Get the current EOA.  Verify that it is greater than
+ *                 or equal to f->shared->eoa_pre_fsm_fsalloc.  If the 
+ *                 current eoa is equal to f->shared->eoa_pre_fsm_fsalloc,
+ *                 no self referential FSMs were stored, and we are done.
+ *
+ *                 NOTE:  This will have to be reworked somewhat for 
+ *                 cache image.
+ *
+ *              3) Load the self referential FSMs.  In passing verify that
+ *                 the lowest address of a FSM header is equal to 
+ *                 f->shared->eoa_pre_fsm_fsalloc.'
+ *
+ *                 Note that we don't have to use any special I/O for 
+ *                 this -- we can use the regular I/O methods even if 
+ *                 paged aggregation and page buffering is enabled.
+ *
+ *              4) Float the FSMs. Ensure that the file space is NOT
+ *                 released.
+ *
+ *              5) Set EOA equal to f->shared->eoa_pre_fsm_fsalloc, 
+ *                 and then set f->shared->eoa_pre_fsm_fsalloc to 
+ *                 HADDR_UNDEF.
+ *
+ *		   If page buffering, verify that the new EOA is 
+ *                 on a page boundary, and expunge any pages in the 
+ *                 page buffer after the new EOA.
+ *
+ *              Note that this function is also called from test code
+ *              when it is necessary to startup a self referential 
+ *              free space manager prior to the first file space 
+ *              allocation / deallocation.  Failure to do so will 
+ *              result in assertion failures in this function on
+ *              the first file space allocation / deallocation.
+ *                 
+ * Return:      SUCCEED/FAIL
  *
- * Programmer:  Quincey Koziol
- *              Tuesday, January 22, 2008
+ * Programmer:  John Mainzer
+ *              12/11/16
  *
- * Modifications:
- *      Vailin Choi; July 2012
- *      As the default free-list mapping is changed to H5FD_FLMAP_DICHOTOMY,
- *      modifications are needed to shrink EOA if the last section of each free-space manager
- *      and the remaining space in the two aggregators are at EOA.
-
  *-------------------------------------------------------------------------
  */
 herr_t
-H5MF_close(H5F_t *f, hid_t dxpl_id)
+H5MF_tidy_self_referential_fsm_hack(H5F_t *f, hid_t dxpl_id)
 {
+    haddr_t eoa;                        /* EOA of file */
+    hsize_t tail_size = 0;              /* Size of chunk to free */
     H5P_genplist_t *dxpl = NULL;        /* DXPL for setting ring */
-    H5AC_ring_t curr_ring;              /* Current ring value */
-    H5AC_ring_t orig_ring = H5AC_RING_INV;      /* Original ring value */
-    H5FD_mem_t type;                    /* Memory type for iteration */
+    H5AC_ring_t orig_ring = H5AC_RING_INV; /* Original ring value */
+    haddr_t first_srfsm_hdr = HADDR_UNDEF; /* Addr of first self referential */
+                                           /* fsm header in file             */
+    H5FS_stat_t fs_stat;                /* Information for hdr FSM */
+    H5F_mem_page_t sm_fshdr_fs_type;    /* Small fs hdr fsm */
+    H5F_mem_page_t sm_fssinfo_fs_type;  /* Small fs sinfo fsm */
+    H5F_mem_page_t lg_fshdr_fs_type;    /* Large fs hdr fsm */
+    H5F_mem_page_t lg_fssinfo_fs_type;  /* Large fs sinfo fsm */
     hbool_t reset_ring = FALSE;         /* Whether the ring was set */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI_TAG(dxpl_id, H5AC__FREESPACE_TAG, FAIL)
-#ifdef H5MF_ALLOC_DEBUG
-HDfprintf(stderr, "%s: Entering\n", FUNC);
-#endif /* H5MF_ALLOC_DEBUG */
 
     /* check args */
     HDassert(f);
     HDassert(f->shared);
-    HDassert(f->shared->lf);
-    HDassert(f->shared->sblock);
+    HDassert(f->shared->fs_persist);
+    HDassert(f->shared->first_alloc_dealloc);
 
-    /* Set the ring type in the DXPL.  In most cases, we will
-     * need H5AC_RING_RDFSM, so initialy set the ring in
-     * the DXPL to that value.  We will alter this later if 
-     * needed.
+    /* Set the ring type in the DXPL.  Since we are only dealing with 
+     * self referential FSMs, we will only need H5AC_RING_MDFSM.
      */
-    if(H5AC_set_ring(dxpl_id, H5AC_RING_RDFSM, &dxpl, &orig_ring) < 0)
+    if(H5AC_set_ring(dxpl_id, H5AC_RING_MDFSM, &dxpl, &orig_ring) < 0)
         HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value")
     reset_ring = TRUE;
-    curr_ring = H5AC_RING_RDFSM;
 
-    /* Free the space in aggregators */
-    /* (for space not at EOF, it may be put into free space managers) */
-    if(H5MF_free_aggrs(f, dxpl_id) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTFREE, FAIL, "can't free aggregators")
+    /* 1) Verify that f->shared->first_alloc_dealloc is TRUE, 
+     *    and then set it to FALSE.  
+     */
+    HDassert(f->shared->first_alloc_dealloc);
+    f->shared->first_alloc_dealloc = FALSE;
 
-    /* Trying shrinking the EOA for the file */
-    if(H5MF__close_shrink_eoa(f, dxpl_id) < 0)
-        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSHRINK, FAIL, "can't shrink eoa")
 
-    /* Making free-space managers persistent for superblock version >= 2 */
-    if(f->shared->sblock->super_vers >= HDF5_SUPERBLOCK_VERSION_2
-            && f->shared->fs_strategy == H5F_FILE_SPACE_ALL_PERSIST) {
-        H5O_fsinfo_t fsinfo;		/* Free space manager info message */
+    /* 2) Get the current EOA.  Verify that it is greater than
+     *    or equal to f->shared->eoa_pre_fsm_fsalloc.  If the 
+     *    current eoa is equal to f->shared->eoa_pre_fsm_fsalloc,
+     *    no self referential FSMs were stored, and we are done.
+     *
+     *    NOTE:  This will have to be reworked somewhat for 
+     *           cache image.
+     */
+    if(HADDR_UNDEF == (eoa = H5FD_get_eoa(f->shared->lf, H5FD_MEM_DEFAULT)))
+        HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "unable to get EOA")
+    HDassert(H5F_addr_le(f->shared->eoa_pre_fsm_fsalloc, eoa));
 
-        /* Superblock extension and free space manager message should 
-         * exist at this point -- verify at least the former.
-         */
-        HDassert(H5F_addr_defined(f->shared->sblock->ext_addr));
+    if(H5F_addr_eq(f->shared->eoa_pre_fsm_fsalloc, eoa))
+        HGOTO_DONE(SUCCEED)
 
-        /* Note that unlike the previous version of this code, we do not 
-         * delete free space managers that have no section to store.
-         *
-         * Can't do this, as that would involve freeing file space, which would 
-         * dirty the free space manager in question. 
-         * 
-         * Fortunately, the code doesn't seem to care about this.
-         */
 
-        /* Gather data for the free space manager superblock extension message.
-         * 
-         * In passing, verify that all the free space managers are closed.
-         */
-        for(type = H5FD_MEM_SUPER; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type))
-            fsinfo.fs_addr[type - 1] = f->shared->fs_addr[type];
-	fsinfo.strategy = f->shared->fs_strategy;
-	fsinfo.threshold = f->shared->fs_threshold;
+    /* 3) Load the self referential FSMs.  In passing verify that
+     *    the lowest address of a FSM header is equal to 
+     *    f->shared->eoa_pre_fsm_fsalloc.'
+     *
+     *    Note that we don't have to use any special I/O for 
+     *    this -- we can use the regular I/O methods even if 
+     *    paged aggregation and page buffering is enabled.
+     */
+    H5MF_alloc_to_fs_type(f, H5FD_MEM_FSPACE_HDR, (size_t)1, &sm_fshdr_fs_type);
+    H5MF_alloc_to_fs_type(f, H5FD_MEM_FSPACE_SINFO, (size_t)1, &sm_fssinfo_fs_type);
+    HDassert(sm_fshdr_fs_type > H5F_MEM_PAGE_DEFAULT);
+    HDassert(sm_fshdr_fs_type < H5F_MEM_PAGE_LARGE_SUPER);
 
-        /* Write the free space manager message -- message must already exist */
-        if(H5F_super_ext_write_msg(f, dxpl_id, H5O_FSINFO_ID, &fsinfo, FALSE, H5O_MSG_NO_FLAGS_SET) < 0)
-            HGOTO_ERROR(H5E_RESOURCE, H5E_WRITEERROR, FAIL, "error in writing message to superblock extension")
+    HDassert(sm_fssinfo_fs_type > H5F_MEM_PAGE_DEFAULT);
+    HDassert(sm_fssinfo_fs_type < H5F_MEM_PAGE_LARGE_SUPER);
 
-	/* Final close of free-space managers */
-	for(type = H5FD_MEM_SUPER; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type)) {
-	    if(f->shared->fs_man[type]) {
-                H5AC_ring_t needed_ring;    /* Ring value needed for this iteration */
+    HDassert(NULL == f->shared->fs_man[sm_fshdr_fs_type]);
+    HDassert(NULL == f->shared->fs_man[sm_fssinfo_fs_type]);
 
-                /* test to see if we need to switch rings -- do so if required */
-                if((H5MF_ALLOC_TO_FS_TYPE(f, type) == H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_HDR))
-                        || (H5MF_ALLOC_TO_FS_TYPE(f, type) == H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_SINFO)))
-                    needed_ring = H5AC_RING_MDFSM;
-                else
-                    needed_ring = H5AC_RING_RDFSM;
+    if(H5F_addr_defined(f->shared->fs_addr[sm_fshdr_fs_type])) {
+        first_srfsm_hdr = f->shared->fs_addr[sm_fshdr_fs_type];
 
-                if(needed_ring != curr_ring) {
-                    if(H5AC_set_ring(dxpl_id, needed_ring, &dxpl, &curr_ring) < 0)
-                        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value (3)")
-                    curr_ring = needed_ring;
-                } /* end if */
+        /* open the FSM */
+        if(H5MF_open_fstype(f, dxpl_id, sm_fshdr_fs_type) < 0)
+             HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL,  "can't initialize file free space manager")
 
-                HDassert(f->shared->fs_state[type] == H5F_FS_STATE_OPEN);
-		if(H5FS_close(f, dxpl_id, f->shared->fs_man[type]) < 0)
-		    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't close free space manager")
-		f->shared->fs_man[type] = NULL;
-		f->shared->fs_state[type] = H5F_FS_STATE_CLOSED;
-	    } /* end if */
-	    f->shared->fs_addr[type] = HADDR_UNDEF;
-	} /* end for */
+        HDassert(f->shared->fs_man[sm_fshdr_fs_type]);
+    } /* end if */
 
-        /* Verify that we haven't dirtied any metadata cache entries 
-         * from the metadata free space manager ring out.
-         */
-        HDassert(H5AC_cache_is_clean(f, H5AC_RING_MDFSM));
+    if((sm_fshdr_fs_type != sm_fssinfo_fs_type) &&
+            (H5F_addr_defined(f->shared->fs_addr[sm_fssinfo_fs_type]))) {
 
-        /* Verify that the aggregators are still shutdown. */
-        HDassert(f->shared->sdata_aggr.tot_size == 0);
-        HDassert(f->shared->sdata_aggr.addr == 0);
-        HDassert(f->shared->sdata_aggr.size == 0);
-        HDassert(f->shared->meta_aggr.tot_size == 0);
-        HDassert(f->shared->meta_aggr.addr == 0);
-        HDassert(f->shared->meta_aggr.size == 0);
-    } /* end if */
-    else {  /* super_vers can be 0, 1, 2 */
-        /* Close and delete freespace managers from the file */
-        if(H5MF__close_delete(f, dxpl_id, &dxpl) < 0)
-            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't initialize file free space")
+        if(!H5F_addr_defined(first_srfsm_hdr) ||
+                (H5F_addr_defined(first_srfsm_hdr) &&
+                    H5F_addr_lt(f->shared->fs_addr[sm_fssinfo_fs_type], first_srfsm_hdr)))
+            first_srfsm_hdr = f->shared->fs_addr[sm_fssinfo_fs_type];
 
-          /* moved code that was for both the persistant and non persistant free
-           * space managers to the non-persistant case.  In the persistant
-           * case, the EOA should already be as shrunked as it can be, and the 
-           * aggregators should alread be shut down.
-           */
+        HDassert(NULL == f->shared->fs_man[sm_fssinfo_fs_type]);
 
-        /* Free the space in aggregators (again) */
-        /* (in case any free space information re-started them) */
-        if(H5MF_free_aggrs(f, dxpl_id) < 0)
-            HGOTO_ERROR(H5E_FILE, H5E_CANTFREE, FAIL, "can't free aggregators")
+        /* open the FSM */
+        if(H5MF_open_fstype(f, dxpl_id, sm_fssinfo_fs_type) < 0)
+             HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't initialize file free space manager")
 
-        /* Trying shrinking the EOA for the file */
-        /* (in case any free space is now at the EOA) */
-        if(H5MF__close_shrink_eoa(f, dxpl_id) < 0)
-            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSHRINK, FAIL, "can't shrink eoa")
-    } /* end else */
+        HDassert(f->shared->fs_man[sm_fssinfo_fs_type]);
+    } /* end if */
 
-done:
-    /* Reset the ring in the DXPL */
-    if(reset_ring)
-        if(H5AC_reset_ring(dxpl, orig_ring) < 0)
-            HDONE_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set property value")
+    if(H5F_PAGED_AGGR(f)) {
+        H5MF_alloc_to_fs_type(f, H5FD_MEM_FSPACE_HDR, f->shared->fs_page_size + 1, &lg_fshdr_fs_type);
+        H5MF_alloc_to_fs_type(f, H5FD_MEM_FSPACE_SINFO, f->shared->fs_page_size + 1, &lg_fssinfo_fs_type);
 
-#ifdef H5MF_ALLOC_DEBUG
-HDfprintf(stderr, "%s: Leaving\n", FUNC);
-#endif /* H5MF_ALLOC_DEBUG */
-    FUNC_LEAVE_NOAPI_TAG(ret_value, FAIL)
-} /* end H5MF_close() */
+        HDassert(lg_fshdr_fs_type >= H5F_MEM_PAGE_LARGE_SUPER);
+        HDassert(lg_fshdr_fs_type < H5F_MEM_PAGE_NTYPES);
 
-
-/*-------------------------------------------------------------------------
- * Function:    H5MF_sects_cb()
- *
- * Purpose:	Iterator callback for each free-space section
- *		Retrieve address and size into user data
- *
- * Return:	Always succeed
- *
- * Programmer:  Vailin Choi
- *	        July 1st, 2009
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5MF_sects_cb(H5FS_section_info_t *_sect, void *_udata)
-{
-    H5MF_free_section_t *sect = (H5MF_free_section_t *)_sect;
-    H5MF_sect_iter_ud_t *udata = (H5MF_sect_iter_ud_t *)_udata;
+        HDassert(lg_fssinfo_fs_type >= H5F_MEM_PAGE_LARGE_SUPER);
+        HDassert(lg_fssinfo_fs_type < H5F_MEM_PAGE_NTYPES);
 
-    FUNC_ENTER_NOAPI_NOINIT_NOERR
+        HDassert(NULL == f->shared->fs_man[lg_fshdr_fs_type]);
+        HDassert(NULL == f->shared->fs_man[lg_fssinfo_fs_type]);
 
-    if(udata->sect_idx < udata->sect_count) {
-        udata->sects[udata->sect_idx].addr = sect->sect_info.addr;
-        udata->sects[udata->sect_idx].size  = sect->sect_info.size;
-        udata->sect_idx++;
-    } /* end if */
+        if(H5F_addr_defined(f->shared->fs_addr[lg_fshdr_fs_type])) {
+            if(!H5F_addr_defined(first_srfsm_hdr) ||
+                    (H5F_addr_defined(first_srfsm_hdr) &&
+                        H5F_addr_lt(f->shared->fs_addr[lg_fshdr_fs_type], first_srfsm_hdr)))
+                first_srfsm_hdr = f->shared->fs_addr[lg_fshdr_fs_type];
 
-    FUNC_LEAVE_NOAPI(SUCCEED)
-} /* H5MF_sects_cb() */
+            HDassert(NULL == f->shared->fs_man[lg_fshdr_fs_type]);
 
-
-/*-------------------------------------------------------------------------
- * Function:    H5MF_get_free_sections()
- *
- * Purpose: 	To iterate over one or all free-space managers for:
- *			# of sections
- *			section info as defined in H5F_sect_info_t
- *
- * Return:	SUCCEED/FAIL
- *
- * Programmer:  Vailin Choi
- *	        July 1st, 2009
- *
- *-------------------------------------------------------------------------
- */
-ssize_t
-H5MF_get_free_sections(H5F_t *f, hid_t dxpl_id, H5FD_mem_t type, size_t nsects, H5F_sect_info_t *sect_info)
-{
-    size_t 	total_sects = 0;	/* total number of sections */
-    H5MF_sect_iter_ud_t sect_udata;     /* User data for callback */
-    H5P_genplist_t *dxpl = NULL;        /* DXPL for setting ring */
-    H5AC_ring_t curr_ring;              /* Current ring value */
-    H5AC_ring_t needed_ring;            /* Ring value needed for this iteration */
-    H5AC_ring_t orig_ring = H5AC_RING_INV;      /* Original ring value */
-    H5FD_mem_t	start_type, end_type;   /* Memory types to iterate over */
-    H5FD_mem_t 	ty;     		/* Memory type for iteration */
-    hbool_t reset_ring = FALSE;         /* Whether the ring was set */
-    ssize_t 	ret_value = -1;         /* Return value */
+            /* open the FSM */
+            if(H5MF_open_fstype(f, dxpl_id, lg_fshdr_fs_type) < 0)
+                 HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't initialize file free space manager")
+            HDassert(f->shared->fs_man[lg_fshdr_fs_type]);
+        } /* end if */
 
-    FUNC_ENTER_NOAPI_TAG(dxpl_id, H5AC__FREESPACE_TAG, FAIL)
+        if(lg_fshdr_fs_type != lg_fssinfo_fs_type && H5F_addr_defined(f->shared->fs_addr[lg_fssinfo_fs_type])) {
+            if(!H5F_addr_defined(first_srfsm_hdr) ||
+                    (H5F_addr_defined(first_srfsm_hdr) &&
+                        H5F_addr_lt(f->shared->fs_addr[lg_fssinfo_fs_type], first_srfsm_hdr)))
+                first_srfsm_hdr = f->shared->fs_addr[lg_fssinfo_fs_type];
 
-    /* check args */
-    HDassert(f);
-    HDassert(f->shared);
-    HDassert(f->shared->lf);
+            HDassert(NULL == f->shared->fs_man[lg_fssinfo_fs_type]);
 
-    /* Determine start/end points for loop */
-    if(type == H5FD_MEM_DEFAULT) {
-	start_type = H5FD_MEM_SUPER;
-	end_type = H5FD_MEM_NTYPES;
+            /* open the FSM */
+            if(H5MF_open_fstype(f, dxpl_id, lg_fssinfo_fs_type) < 0)
+                 HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't initialize file free space manager")
+            HDassert(f->shared->fs_man[lg_fssinfo_fs_type]);
+        } /* end if */
+    } /* end if */
+    HDassert(H5F_addr_eq(first_srfsm_hdr, f->shared->eoa_pre_fsm_fsalloc));
+ 
+    /* 4) Float the FSMs. Ensure that the file space is NOT released. */
+    if(f->shared->fs_man[sm_fshdr_fs_type]) {
+        /* Sanity check: Query free space manager info for this type */
+        if(H5FS_stat_info(f, f->shared->fs_man[sm_fshdr_fs_type], &fs_stat) < 0)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't get free-space info")
+
+        HDassert(H5F_addr_defined(fs_stat.addr));
+        HDassert(H5F_addr_defined(fs_stat.sect_addr));
+        if(H5FS_free(f, f->shared->fs_man[sm_fshdr_fs_type], dxpl_id, FALSE) < 0)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't release free-space headers")
+        f->shared->fs_addr[sm_fshdr_fs_type] = HADDR_UNDEF;
     } /* end if */
-    else {
-	start_type = end_type = type;
-	H5_INC_ENUM(H5FD_mem_t, end_type);
-    } /* end else */
 
-    /* Set up user data for section iteration */
-    sect_udata.sects = sect_info;
-    sect_udata.sect_count = nsects;
-    sect_udata.sect_idx = 0;
+    if(sm_fshdr_fs_type != sm_fssinfo_fs_type && f->shared->fs_man[sm_fssinfo_fs_type]) {
+        /* Sanity check: Query free space manager info for this type */
+        if(H5FS_stat_info(f, f->shared->fs_man[sm_fssinfo_fs_type], &fs_stat) < 0)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't get free-space info")
 
-    /* Set the ring type in the DXPL.  Note that if we are 
-     * scanning a number of different free space managers, 
-     * we may have to change the ring
-     */
-    if((H5MF_ALLOC_TO_FS_TYPE(f, start_type) == H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_HDR))
-            || (H5MF_ALLOC_TO_FS_TYPE(f, start_type) == H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_SINFO)))
-        needed_ring = H5AC_RING_MDFSM;
-    else
-        needed_ring = H5AC_RING_RDFSM;
-    curr_ring = needed_ring;
-    if(H5AC_set_ring(dxpl_id, needed_ring, &dxpl, &orig_ring) < 0)
-        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value")
-    reset_ring = TRUE;
-
-    /* Iterate over memory types, retrieving the number of sections of each type */
-    for(ty = start_type; ty < end_type; H5_INC_ENUM(H5FD_mem_t, ty)) {
-	hbool_t fs_started = FALSE;
+        HDassert(H5F_addr_defined(fs_stat.addr));
+        HDassert(H5F_addr_defined(fs_stat.sect_addr));
+        if(H5FS_free(f, f->shared->fs_man[sm_fssinfo_fs_type], dxpl_id, FALSE) < 0)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't release free-space headers")
+        f->shared->fs_addr[sm_fssinfo_fs_type] = HADDR_UNDEF;
+    } /* end if */
 
-        /* test to see if we need to switch rings -- do so if required */
-        if((H5MF_ALLOC_TO_FS_TYPE(f, ty) == H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_HDR))
-                || (H5MF_ALLOC_TO_FS_TYPE(f, ty) == H5MF_ALLOC_TO_FS_TYPE(f, H5FD_MEM_FSPACE_SINFO)))
-            needed_ring = H5AC_RING_MDFSM;
-        else
-            needed_ring = H5AC_RING_RDFSM;
+    if(H5F_PAGED_AGGR(f)) {
+        if(f->shared->fs_man[lg_fshdr_fs_type]) {
+            /* Sanity check: Query free space manager info for this type */
+            if(H5FS_stat_info(f, f->shared->fs_man[lg_fshdr_fs_type], &fs_stat) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "can't get free-space info")
 
-        if(needed_ring != curr_ring) {
-            if(H5AC_set_ring(dxpl_id, needed_ring, &dxpl, &curr_ring) < 0)
-                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set ring value (2)")
-            curr_ring = needed_ring;
+            HDassert(H5F_addr_defined(fs_stat.addr));
+            HDassert(H5F_addr_defined(fs_stat.sect_addr));
+            if(H5FS_free(f, f->shared->fs_man[lg_fshdr_fs_type], dxpl_id, FALSE) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't float free-space headers")
+            f->shared->fs_addr[lg_fshdr_fs_type] = HADDR_UNDEF;
         } /* end if */
 
-	/* Open free space manager of this type, if it isn't already */
-        if(!f->shared->fs_man[ty] && H5F_addr_defined(f->shared->fs_addr[ty])) {
-	    if(H5MF__alloc_open(f, dxpl_id, ty) < 0)
-		HGOTO_ERROR(H5E_RESOURCE, H5E_CANTOPENOBJ, FAIL, "can't initialize file free space")
-            HDassert(f->shared->fs_man[ty]);
-	    fs_started = TRUE;
-	} /* end if */
-
-	/* Check if f there's free space sections of this type */
-        if(f->shared->fs_man[ty]) {
-            hsize_t hnums = 0;          /* Total # of sections */
-            size_t nums;                /* Total # of sections, cast to a size_t */
-
-            /* Query how many sections of this type */
-	    if(H5FS_sect_stats(f->shared->fs_man[ty], NULL, &hnums) < 0)
-		HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "can't query free space stats")
-            H5_CHECKED_ASSIGN(nums, size_t, hnums, hsize_t);
-
-            /* Increment total # of sections */
-            total_sects += nums;
-
-            /* Check if we should retrieve the section info */
-            if(sect_info && nums > 0) {
-                /* Iterate over all the free space sections of this type, adding them to the user's section info */
-                if(H5FS_sect_iterate(f, dxpl_id, f->shared->fs_man[ty], H5MF_sects_cb, &sect_udata) < 0)
-                    HGOTO_ERROR(H5E_RESOURCE, H5E_BADITER, FAIL, "can't iterate over sections")
-            } /* end if */
+        if(lg_fshdr_fs_type != lg_fssinfo_fs_type && f->shared->fs_man[lg_fssinfo_fs_type]) {
+            /* Sanity check: Query free space manager info for this type */
+            if(H5FS_stat_info(f, f->shared->fs_man[lg_fssinfo_fs_type], &fs_stat) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "can't get free-space info")
+
+            HDassert(H5F_addr_defined(fs_stat.addr));
+            HDassert(H5F_addr_defined(fs_stat.sect_addr));
+            if(H5FS_free(f, f->shared->fs_man[lg_fssinfo_fs_type], dxpl_id, FALSE) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't float free-space headers")
+            f->shared->fs_addr[lg_fssinfo_fs_type] = HADDR_UNDEF;
         } /* end if */
+    } /* end if */
 
-	/* Close the free space manager of this type, if we started it here */
-        if(fs_started)
-            if(H5MF__alloc_close(f, dxpl_id, ty) < 0)
-	        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTCLOSEOBJ, FAIL, "can't close file free space")
-    } /* end for */
+    /* 5) Set EOA equal to f->shared->eoa_pre_fsm_fsalloc, 
+     *    and then set f->shared->eoa_pre_fsm_fsalloc to 
+     *    HADDR_UNDEF.
+     *
+     *    If page buffering, verify that the new EOA is 
+     *    on a page boundary, and expunge any pages in the 
+     *    page buffer after the new EOA.
+     */
+    if(!H5F_PAGED_AGGR(f)) {
+        /* Verify that the aggregators are still shutdown. */
+        HDassert(f->shared->sdata_aggr.tot_size == 0);
+        HDassert(f->shared->sdata_aggr.addr == 0);
+        HDassert(f->shared->sdata_aggr.size == 0);
 
-    /* Set return value */
-    ret_value = (ssize_t)total_sects;
+        HDassert(f->shared->meta_aggr.tot_size == 0);
+        HDassert(f->shared->meta_aggr.addr == 0);
+        HDassert(f->shared->meta_aggr.size == 0);
+    } /* end if */
+
+    tail_size = (hsize_t)(eoa - f->shared->eoa_pre_fsm_fsalloc);
+
+    /* Release file space allocated to self referential FSMs */
+    if(H5F_free(f, dxpl_id, H5FD_MEM_DEFAULT, f->shared->eoa_pre_fsm_fsalloc, tail_size) < 0)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, FAIL, "driver free request failed")
+    if(HADDR_UNDEF == (eoa = H5FD_get_eoa(f->shared->lf, H5FD_MEM_DEFAULT)))
+        HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "unable to get EOA")
+    HDassert(H5F_addr_eq(f->shared->eoa_pre_fsm_fsalloc, eoa));
+
+    f->shared->eoa_pre_fsm_fsalloc = HADDR_UNDEF;
+
+    HDassert((!H5F_PAGED_AGGR(f)) || (0 == (eoa % f->shared->fs_page_size)));
 
 done:
     /* Reset the ring in the DXPL */
@@ -2349,5 +3911,5 @@ done:
             HDONE_ERROR(H5E_RESOURCE, H5E_CANTSET, FAIL, "unable to set property value")
 
     FUNC_LEAVE_NOAPI_TAG(ret_value, FAIL)
-} /* H5MF_get_free_sections() */
+} /* H5MF_tidy_self_referential_fsm_hack() */
 
diff --git a/src/H5MFaggr.c b/src/H5MFaggr.c
index 1510645..de98bf1 100644
--- a/src/H5MFaggr.c
+++ b/src/H5MFaggr.c
@@ -57,8 +57,10 @@
 /********************/
 /* Local Prototypes */
 /********************/
-static herr_t H5MF_aggr_free(H5F_t *f, hid_t dxpl_id, H5FD_mem_t type,
+static herr_t H5MF__aggr_free(H5F_t *f, hid_t dxpl_id, H5FD_mem_t type,
     H5F_blk_aggr_t *aggr);
+static haddr_t H5MF__aggr_alloc(H5F_t *f, hid_t dxpl_id, H5F_blk_aggr_t *aggr,
+    H5F_blk_aggr_t *other_aggr, H5FD_mem_t type, hsize_t size);
 
 
 /*********************/
@@ -78,86 +80,9 @@ static herr_t H5MF_aggr_free(H5F_t *f, hid_t dxpl_id, H5FD_mem_t type,
 
 
 /*-------------------------------------------------------------------------
- * Function:    H5MF_vfd_alloc
- *
- * Purpose:     Allocate SIZE bytes of file memory via H5FD_alloc() and return
- *              the relative address where that contiguous chunk of file memory
- *              exists.
- *		The TYPE argument describes the purpose for which the storage
- *		is being requested.
- *
- * Return:      Success:        The file address of new chunk.
- *              Failure:        HADDR_UNDEF
- *
- * Programmer:  Quincey Koziol
- *              January 2, 2017
- *
- *-------------------------------------------------------------------------
- */
-haddr_t
-H5MF_vfd_alloc(H5F_t *f, hid_t dxpl_id, H5FD_mem_t alloc_type, hsize_t size,
-    hbool_t keep_fragment)
-{
-    haddr_t eoa;                        /* Initial EOA for the file */
-    haddr_t eoa_frag_addr = HADDR_UNDEF; /* Address of fragment at EOA */
-    hsize_t eoa_frag_size = 0;          /* Size of fragment at EOA */
-    haddr_t ret_value = HADDR_UNDEF;    /* Return value */
-
-    FUNC_ENTER_NOAPI(HADDR_UNDEF)
-#ifdef H5MF_ALLOC_DEBUG
-HDfprintf(stderr, "%s: alloc_type = %u, size = %Hu\n", FUNC, (unsigned)alloc_type, size);
-#endif /* H5MF_ALLOC_DEBUG */
-
-    /* check arguments */
-    HDassert(f);
-    HDassert(f->shared);
-    HDassert(f->shared->lf);
-    HDassert(size > 0);
-
-    /* Get the EOA for the file -- need for sanity check below */
-    if(HADDR_UNDEF == (eoa = H5F_get_eoa(f, alloc_type)))
-       HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, HADDR_UNDEF, "Unable to get eoa")
-
-    /* Check for overlap into temporary allocation space */
-    if(H5F_addr_gt((eoa + size), f->shared->tmp_addr))
-        HGOTO_ERROR(H5E_RESOURCE, H5E_BADRANGE, HADDR_UNDEF, "hdr file space alloc will overlap into 'temporary' file space")
-
-    /* Allocate space for the header */
-    if(HADDR_UNDEF == (ret_value = H5FD_alloc(f->shared->lf, dxpl_id, alloc_type, f, size, &eoa_frag_addr, &eoa_frag_size)))
-        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, HADDR_UNDEF, "can't allocate file space for hdr")
-
-    /* Sanity check for overlapping into file's temporary allocation space */
-    HDassert(H5F_addr_le((ret_value + size), f->shared->tmp_addr));
-
-    /* If the file alignment is 1, there should be no eoa fragment */
-    HDassert((eoa_frag_size == 0) || (f->shared->alignment != 1));
-
-    /* Check if fragment was generated and we want to keep it */
-    if(keep_fragment && eoa_frag_size > 0) {
-        /* Sanity check */
-        HDassert(H5F_addr_defined(eoa_frag_addr));
-
-        /* Put fragment on the free list */
-        if(H5MF_xfree(f, alloc_type, dxpl_id, eoa_frag_addr, eoa_frag_size) < 0)
-            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, HADDR_UNDEF, "can't free eoa fragment")
-    } /* end if */
-
-done:
-#ifdef H5MF_ALLOC_DEBUG
-HDfprintf(stderr, "%s: Leaving: ret_value = %a, size = %Hu\n", FUNC, ret_value, size);
-#endif /* H5MF_ALLOC_DEBUG */
-#ifdef H5MF_ALLOC_DEBUG_DUMP
-H5MF_sects_dump(f, dxpl_id, stderr);
-#endif /* H5MF_ALLOC_DEBUG_DUMP */
-
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5MF_vfd_alloc() */
-
-
-/*-------------------------------------------------------------------------
  * Function:    H5MF_aggr_vfd_alloc
  *
- * Purpose:     Allocate SIZE bytes of file memory via H5MF_aggr_alloc()
+ * Purpose:     Allocate SIZE bytes of file memory via H5MF__aggr_alloc()
  *		and return the relative address where that contiguous chunk
  *		of file memory exists.
  *		The TYPE argument describes the purpose for which the storage
@@ -177,9 +102,9 @@ H5MF_aggr_vfd_alloc(H5F_t *f, H5FD_mem_t alloc_type, hid_t dxpl_id, hsize_t size
     haddr_t     ret_value = HADDR_UNDEF;        /* Return value */
 
     FUNC_ENTER_NOAPI(HADDR_UNDEF)
-#ifdef H5MF_ALLOC_DEBUG
+#ifdef H5MF_AGGR_DEBUG
 HDfprintf(stderr, "%s: alloc_type = %u, size = %Hu\n", FUNC, (unsigned)alloc_type, size);
-#endif /* H5MF_ALLOC_DEBUG */
+#endif /* H5MF_AGGR_DEBUG */
 
     /* check arguments */
     HDassert(f);
@@ -190,12 +115,12 @@ HDfprintf(stderr, "%s: alloc_type = %u, size = %Hu\n", FUNC, (unsigned)alloc_typ
     /* Couldn't find anything from the free space manager, go allocate some */
     if(alloc_type != H5FD_MEM_DRAW && alloc_type != H5FD_MEM_GHEAP) {
         /* Handle metadata differently from "raw" data */
-        if(HADDR_UNDEF == (ret_value = H5MF_aggr_alloc(f, dxpl_id, &(f->shared->meta_aggr), &(f->shared->sdata_aggr), alloc_type, size)))
+        if(HADDR_UNDEF == (ret_value = H5MF__aggr_alloc(f, dxpl_id, &(f->shared->meta_aggr), &(f->shared->sdata_aggr), alloc_type, size)))
             HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, HADDR_UNDEF, "can't allocate metadata")
     } /* end if */
     else {
         /* Allocate "raw" data: H5FD_MEM_DRAW and H5FD_MEM_GHEAP */
-        if(HADDR_UNDEF == (ret_value = H5MF_aggr_alloc(f, dxpl_id, &(f->shared->sdata_aggr), &(f->shared->meta_aggr), H5FD_MEM_DRAW, size)))
+        if(HADDR_UNDEF == (ret_value = H5MF__aggr_alloc(f, dxpl_id, &(f->shared->sdata_aggr), &(f->shared->meta_aggr), H5FD_MEM_DRAW, size)))
             HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, HADDR_UNDEF, "can't allocate raw data")
     } /* end else */
 
@@ -203,19 +128,16 @@ HDfprintf(stderr, "%s: alloc_type = %u, size = %Hu\n", FUNC, (unsigned)alloc_typ
     HDassert(H5F_addr_le((ret_value + size), f->shared->tmp_addr));
 
 done:
-#ifdef H5MF_ALLOC_DEBUG
+#ifdef H5MF_AGGR_DEBUG
 HDfprintf(stderr, "%s: Leaving: ret_value = %a, size = %Hu\n", FUNC, ret_value, size);
-#endif /* H5MF_ALLOC_DEBUG */
-#ifdef H5MF_ALLOC_DEBUG_DUMP
-H5MF_sects_dump(f, dxpl_id, stderr);
-#endif /* H5MF_ALLOC_DEBUG_DUMP */
+#endif /* H5MF_AGGR_DEBUG */
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5MF_aggr_vfd_alloc() */
 
 
 /*-------------------------------------------------------------------------
- * Function:    H5MF_aggr_alloc
+ * Function:    H5MF__aggr_alloc
  *
  * Purpose:     Try to allocate SIZE bytes of memory from an aggregator
  *              block if possible.
@@ -228,8 +150,8 @@ H5MF_sects_dump(f, dxpl_id, stderr);
  *
  *-------------------------------------------------------------------------
  */
-haddr_t
-H5MF_aggr_alloc(H5F_t *f, hid_t dxpl_id, H5F_blk_aggr_t *aggr,
+static haddr_t
+H5MF__aggr_alloc(H5F_t *f, hid_t dxpl_id, H5F_blk_aggr_t *aggr,
     H5F_blk_aggr_t *other_aggr, H5FD_mem_t type, hsize_t size)
 {
     haddr_t     eoa_frag_addr = HADDR_UNDEF;    /* Address of fragment at EOA */
@@ -237,7 +159,7 @@ H5MF_aggr_alloc(H5F_t *f, hid_t dxpl_id, H5F_blk_aggr_t *aggr,
     haddr_t	eoa = HADDR_UNDEF;      	/* Initial EOA for the file */
     haddr_t     ret_value = HADDR_UNDEF;        /* Return value */
 
-    FUNC_ENTER_NOAPI(HADDR_UNDEF)
+    FUNC_ENTER_STATIC
 #ifdef H5MF_AGGR_DEBUG
 HDfprintf(stderr, "%s: type = %u, size = %Hu\n", FUNC, (unsigned)type, size);
 #endif /* H5MF_AGGR_DEBUG */
@@ -257,11 +179,11 @@ HDfprintf(stderr, "%s: type = %u, size = %Hu\n", FUNC, (unsigned)type, size);
         HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, HADDR_UNDEF, "Unable to get eoa")
 
     /*
-     * If the aggregation feature is enabled for this file and strategy is not H5F_FILE_SPACE_VFD,
+     * If the aggregation feature is enabled for this file and strategy is not H5F_FILE_SPACE_NONE,
      * allocate "generic" space and sub-allocate out of that, if possible.
-     * Otherwise just allocate through H5FD_alloc().
+     * Otherwise just allocate through H5F_alloc().
      */
-    if((f->shared->feature_flags & aggr->feature_flag) && f->shared->fs_strategy != H5F_FILE_SPACE_VFD) {
+    if((f->shared->feature_flags & aggr->feature_flag) && f->shared->fs_strategy != H5F_FSPACE_STRATEGY_NONE) {
         haddr_t	aggr_frag_addr = HADDR_UNDEF;   /* Address of aggregrator fragment */
         hsize_t	aggr_frag_size = 0;             /* Size of aggregator fragment */
         hsize_t alignment;                      /* Alignment of this section */
@@ -273,12 +195,12 @@ HDfprintf(stderr, "%s: aggr = {%a, %Hu, %Hu}\n", FUNC, aggr->addr, aggr->tot_siz
 #endif /* H5MF_AGGR_DEBUG */
 
         /* Turn off alignment if allocation < threshold */
-	alignment = f->shared->alignment;
-	if(!((alignment > 1) && (size >= f->shared->threshold)))
+	alignment = H5F_ALIGNMENT(f);
+	if(!((alignment > 1) && (size >= H5F_THRESHOLD(f))))
 	    alignment = 0; /* no alignment */
 
         /* Generate fragment if aggregator is mis-aligned */
-	if(alignment && aggr->addr > 0 && (aggr_mis_align = (aggr->addr + H5FD_get_base_addr(f->shared->lf)) % alignment)) {
+	if(alignment && H5F_addr_gt(aggr->addr, 0) && (aggr_mis_align = (aggr->addr + H5F_BASE_ADDR(f)) % alignment)) {
 	    aggr_frag_addr = aggr->addr;
 	    aggr_frag_size = alignment - aggr_mis_align;
 	} /* end if */
@@ -288,7 +210,7 @@ HDfprintf(stderr, "%s: aggr = {%a, %Hu, %Hu}\n", FUNC, aggr->addr, aggr->tot_siz
 
         /* Check if the space requested is larger than the space left in the block */
         if((size + aggr_frag_size) > aggr->size) {
-            htri_t  	was_extended = FALSE;   /* Whether the file was extended */
+            htri_t  	extended = FALSE;   /* Whether the file was extended */
 
             /* Check if the block asked for is too large for 'normal' aggregator block */
             if(size >= aggr->alloc_size) {
@@ -298,32 +220,27 @@ HDfprintf(stderr, "%s: aggr = {%a, %Hu, %Hu}\n", FUNC, aggr->addr, aggr->tot_siz
                 if(H5F_addr_gt((aggr->addr + aggr->size + ext_size), f->shared->tmp_addr))
                     HGOTO_ERROR(H5E_RESOURCE, H5E_BADRANGE, HADDR_UNDEF, "'normal' file space allocation request will overlap into 'temporary' file space")
 
-		if((aggr->addr > 0) && (was_extended = H5FD_try_extend(f->shared->lf, alloc_type, f, dxpl_id, aggr->addr + aggr->size, ext_size)) < 0)
+		if((aggr->addr > 0) && (extended = H5F_try_extend(f, dxpl_id, alloc_type, (aggr->addr + aggr->size), ext_size)) < 0)
 		    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, HADDR_UNDEF, "can't extending space")
-		else if(was_extended) {
+		else if (extended) {
 		    /* aggr->size is unchanged */
 		    ret_value = aggr->addr + aggr_frag_size;
 		    aggr->addr += ext_size;
 		    aggr->tot_size += ext_size;
-		} /* end else-if */
-		else {
-                    /* Check for overlapping into file's temporary allocation space */
-                    if(H5F_addr_gt((eoa + size), f->shared->tmp_addr))
-                        HGOTO_ERROR(H5E_RESOURCE, H5E_BADRANGE, HADDR_UNDEF, "'normal' file space allocation request will overlap into 'temporary' file space")
-
+		} else {
                     /* Release "other" aggregator, if it exists, is at the end of the allocated space,
                      * has allocated more than one block and the unallocated space is greater than its
                      * allocation block size.
                      */
 		    if((other_aggr->size > 0) && (H5F_addr_eq((other_aggr->addr + other_aggr->size), eoa)) &&
 			    (other_aggr->tot_size > other_aggr->size) && ((other_aggr->tot_size - other_aggr->size) >= other_aggr->alloc_size)) {
-                        if(H5MF_aggr_free(f, dxpl_id, other_alloc_type, other_aggr) < 0)
+                        if(H5MF__aggr_free(f, dxpl_id, other_alloc_type, other_aggr) < 0)
                             HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, HADDR_UNDEF, "can't free aggregation block")
 		    } /* end if */
 
                     /* Allocate space from the VFD (i.e. at the end of the file) */
-		    if(HADDR_UNDEF == (ret_value = H5FD_alloc(f->shared->lf, dxpl_id, alloc_type, f, size, &eoa_frag_addr, &eoa_frag_size)))
-			HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, HADDR_UNDEF, "can't allocate aggregation block")
+		    if(HADDR_UNDEF == (ret_value = H5F_alloc(f, dxpl_id, alloc_type, size, &eoa_frag_addr, &eoa_frag_size)))
+			HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, HADDR_UNDEF, "can't allocate file space")
                 } /* end else */
             } /* end if */
 	    else {
@@ -341,9 +258,9 @@ HDfprintf(stderr, "%s: Allocating block\n", FUNC);
                 if(H5F_addr_gt((aggr->addr + aggr->size + ext_size), f->shared->tmp_addr))
                     HGOTO_ERROR(H5E_RESOURCE, H5E_BADRANGE, HADDR_UNDEF, "'normal' file space allocation request will overlap into 'temporary' file space")
 
-		if((aggr->addr > 0) && (was_extended = H5FD_try_extend(f->shared->lf, alloc_type, f, dxpl_id, aggr->addr + aggr->size, ext_size)) < 0)
+		if((aggr->addr > 0) && (extended = H5F_try_extend(f, dxpl_id, alloc_type, (aggr->addr + aggr->size), ext_size)) < 0)
 		    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, HADDR_UNDEF, "can't extending space")
-		else if(was_extended) {
+		else if(extended) {
 		    aggr->addr += aggr_frag_size;
 		    aggr->size += (ext_size - aggr_frag_size);
 		    aggr->tot_size += ext_size;
@@ -351,23 +268,19 @@ HDfprintf(stderr, "%s: Allocating block\n", FUNC);
 		else {
                     haddr_t new_space;          /* Address of new space allocated */
 
-                    /* Check for overlapping into file's temporary allocation space */
-                    if(H5F_addr_gt((eoa + aggr->alloc_size), f->shared->tmp_addr))
-                        HGOTO_ERROR(H5E_RESOURCE, H5E_BADRANGE, HADDR_UNDEF, "'normal' file space allocation request will overlap into 'temporary' file space")
-
                     /* Release "other" aggregator, if it exists, is at the end of the allocated space,
                      * has allocated more than one block and the unallocated space is greater than its
                      * allocation block size.
                      */
 		    if((other_aggr->size > 0) && (H5F_addr_eq((other_aggr->addr + other_aggr->size), eoa)) &&
 			    (other_aggr->tot_size > other_aggr->size) && ((other_aggr->tot_size - other_aggr->size) >= other_aggr->alloc_size)) {
-                        if(H5MF_aggr_free(f, dxpl_id, other_alloc_type, other_aggr) < 0)
+                        if(H5MF__aggr_free(f, dxpl_id, other_alloc_type, other_aggr) < 0)
                             HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, HADDR_UNDEF, "can't free aggregation block")
 		    } /* end if */
 
                     /* Allocate space from the VFD (i.e. at the end of the file) */
-		    if(HADDR_UNDEF == (new_space = H5FD_alloc(f->shared->lf, dxpl_id, alloc_type, f, aggr->alloc_size, &eoa_frag_addr, &eoa_frag_size)))
-			HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, HADDR_UNDEF, "can't allocate aggregation block")
+		    if(HADDR_UNDEF == (new_space = H5F_alloc(f, dxpl_id, alloc_type, aggr->alloc_size, &eoa_frag_addr, &eoa_frag_size)))
+			HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, HADDR_UNDEF, "can't allocate file space")
 
                     /* Return the unused portion of the block to a free list */
                     if(aggr->size > 0)
@@ -408,7 +321,7 @@ HDfprintf(stderr, "%s: Allocating block\n", FUNC);
 		    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, HADDR_UNDEF, "can't free eoa fragment")
 
 	    /* Freeing any possible fragment due to alignment in the block after extension */
-	    if(was_extended && aggr_frag_size)
+            if(extended && aggr_frag_size)
 		if(H5MF_xfree(f, alloc_type, dxpl_id, aggr_frag_addr, aggr_frag_size) < 0)
 		    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, HADDR_UNDEF, "can't free aggregation fragment")
         } /* end if */
@@ -425,12 +338,8 @@ HDfprintf(stderr, "%s: Allocating block\n", FUNC);
         } /* end else */
     } /* end if */
     else {
-        /* Check for overlapping into file's temporary allocation space */
-        if(H5F_addr_gt((eoa + size), f->shared->tmp_addr))
-            HGOTO_ERROR(H5E_RESOURCE, H5E_BADRANGE, HADDR_UNDEF, "'normal' file space allocation request will overlap into 'temporary' file space")
-
         /* Allocate data from the file */
-        if(HADDR_UNDEF == (ret_value = H5FD_alloc(f->shared->lf, dxpl_id, type, f, size, &eoa_frag_addr, &eoa_frag_size)))
+        if(HADDR_UNDEF == (ret_value = H5F_alloc(f, dxpl_id, type, size, &eoa_frag_addr, &eoa_frag_size)))
             HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, HADDR_UNDEF, "can't allocate file space")
 
         /* Check if fragment was generated */
@@ -444,15 +353,15 @@ HDfprintf(stderr, "%s: Allocating block\n", FUNC);
     HDassert(H5F_addr_le((ret_value + size), f->shared->tmp_addr));
 
     /* Post-condition sanity check */
-    if(f->shared->alignment && size >= f->shared->threshold)
-	HDassert(!((ret_value + H5FD_get_base_addr(f->shared->lf)) % f->shared->alignment));
+    if(H5F_ALIGNMENT(f) && size >= H5F_THRESHOLD(f))
+        HDassert(!((ret_value + H5FD_get_base_addr(f->shared->lf)) % H5F_ALIGNMENT(f)));
 
 done:
 #ifdef H5MF_AGGR_DEBUG
 HDfprintf(stderr, "%s: ret_value = %a\n", FUNC, ret_value);
 #endif /* H5MF_AGGR_DEBUG */
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5MF_aggr_alloc() */
+} /* end H5MF__aggr_alloc() */
 
 
 /*-------------------------------------------------------------------------
@@ -524,7 +433,7 @@ H5MF_aggr_try_extend(H5F_t *f, hid_t dxpl_id, H5F_blk_aggr_t *aggr,
 		else {
 		    hsize_t extra = (extra_requested < aggr->alloc_size) ? aggr->alloc_size : extra_requested;
 
-		    if((ret_value = H5FD_try_extend(f->shared->lf, type, f, dxpl_id, (aggr->addr + aggr->size), extra)) < 0)
+                    if((ret_value = H5F_try_extend(f, dxpl_id, type, (aggr->addr + aggr->size), extra)) < 0)
 			HGOTO_ERROR(H5E_RESOURCE, H5E_CANTEXTEND, FAIL, "error extending file")
 		    else if(ret_value == TRUE) {
 			/* Shift the aggregator block by the extra requested */
@@ -905,7 +814,7 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:    H5MF_aggr_free
+ * Function:    H5MF__aggr_free
  *
  * Purpose:     Free the aggregator's space in the file.
  *
@@ -919,11 +828,11 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5MF_aggr_free(H5F_t *f, hid_t dxpl_id, H5FD_mem_t type, H5F_blk_aggr_t *aggr)
+H5MF__aggr_free(H5F_t *f, hid_t dxpl_id, H5FD_mem_t type, H5F_blk_aggr_t *aggr)
 {
     herr_t ret_value = SUCCEED;   	/* Return value */
 
-    FUNC_ENTER_NOAPI(FAIL)
+    FUNC_ENTER_STATIC
 
     /* Sanity check */
     HDassert(f);
@@ -936,7 +845,7 @@ H5MF_aggr_free(H5F_t *f, hid_t dxpl_id, H5FD_mem_t type, H5F_blk_aggr_t *aggr)
     HDassert(f->shared->feature_flags & aggr->feature_flag);
 
     /* Free the remaining space at EOA in the aggregator */
-    if(H5FD_free(f->shared->lf, dxpl_id, type, f, aggr->addr, aggr->size) < 0)
+    if(H5F_free(f, dxpl_id, type, aggr->addr, aggr->size) < 0)
         HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, FAIL, "can't free aggregation block")
 
     /* Reset the aggregator */
@@ -946,7 +855,7 @@ H5MF_aggr_free(H5F_t *f, hid_t dxpl_id, H5FD_mem_t type, H5F_blk_aggr_t *aggr)
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* H5MF_aggr_free() */
+} /* H5MF__aggr_free() */
 
 
 /*-------------------------------------------------------------------------
@@ -978,13 +887,13 @@ H5MF_aggrs_try_shrink_eoa(H5F_t *f, hid_t dxpl_id)
     if((ma_status = H5MF_aggr_can_shrink_eoa(f, H5FD_MEM_DEFAULT, &(f->shared->meta_aggr))) < 0)
         HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "can't query metadata aggregator stats")
     if(ma_status > 0)
-	if(H5MF_aggr_free(f, dxpl_id, H5FD_MEM_DEFAULT, &(f->shared->meta_aggr)) < 0)
+	if(H5MF__aggr_free(f, dxpl_id, H5FD_MEM_DEFAULT, &(f->shared->meta_aggr)) < 0)
 	    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSHRINK, FAIL, "can't check for shrinking eoa")
 
     if((sda_status = H5MF_aggr_can_shrink_eoa(f, H5FD_MEM_DRAW, &(f->shared->sdata_aggr))) < 0)
         HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "can't query small data aggregator stats")
     if(sda_status > 0)
-	if(H5MF_aggr_free(f, dxpl_id, H5FD_MEM_DRAW, &(f->shared->sdata_aggr)) < 0)
+	if(H5MF__aggr_free(f, dxpl_id, H5FD_MEM_DRAW, &(f->shared->sdata_aggr)) < 0)
 	    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTSHRINK, FAIL, "can't check for shrinking eoa")
 
     ret_value = (ma_status || sda_status);
diff --git a/src/H5MFdbg.c b/src/H5MFdbg.c
index 57bac9e..817ea00 100644
--- a/src/H5MFdbg.c
+++ b/src/H5MFdbg.c
@@ -116,7 +116,9 @@ H5MF_sects_debug_cb(H5FS_section_info_t *_sect, void *_udata)
     /* Print generic section information */
     HDfprintf(udata->stream, "%*s%-*s %s\n", udata->indent, "", udata->fwidth,
 	      "Section type:",
-	      (sect->sect_info.type == H5MF_FSPACE_SECT_SIMPLE ? "simple" : "unknown"));
+          (sect->sect_info.type == H5MF_FSPACE_SECT_SIMPLE ? "simple" : 
+          (sect->sect_info.type == H5MF_FSPACE_SECT_SMALL ? "small" : 
+          (sect->sect_info.type == H5MF_FSPACE_SECT_LARGE ? "large" : "unknown"))));
     HDfprintf(udata->stream, "%*s%-*s %a\n", udata->indent, "", udata->fwidth,
 	      "Section address:",
 	      sect->sect_info.addr);
@@ -171,7 +173,7 @@ H5MF_sects_debug(H5F_t *f, hid_t dxpl_id, haddr_t fs_addr, FILE *stream, int ind
     for(type = H5FD_MEM_DEFAULT; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type))
 	if(H5F_addr_eq(f->shared->fs_addr[type], fs_addr)) {
 	    if(!f->shared->fs_man[type])
-		if(H5MF__alloc_open(f, dxpl_id, type) < 0)
+                if(H5MF_open_fstype(f, dxpl_id, type) < 0)
 		    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTINIT, FAIL, "can't initialize file free space")
 
 	    if(f->shared->fs_man[type]) {
@@ -217,11 +219,6 @@ herr_t
 H5MF_sects_dump(H5F_t *f, hid_t dxpl_id, FILE *stream)
 {
     haddr_t eoa;                        /* End of allocated space in the file */
-    haddr_t ma_addr = HADDR_UNDEF;      /* Base "metadata aggregator" address */
-    hsize_t ma_size = 0;                /* Size of "metadata aggregator" */
-    haddr_t sda_addr = HADDR_UNDEF;     /* Base "small data aggregator" address */
-    hsize_t sda_size = 0;               /* Size of "small data aggregator" */
-    H5FD_mem_t type;                    /* Memory type for iteration */
     int indent = 0;                     /* Amount to indent */
     int fwidth = 50;                    /* Field width */
     herr_t ret_value = SUCCEED;         /* Return value */
@@ -244,56 +241,90 @@ HDfprintf(stderr, "%s: Dumping file free space sections\n", FUNC);
 HDfprintf(stderr, "%s: for type = H5FD_MEM_DEFAULT, eoa = %a\n", FUNC, eoa);
 #endif /* H5MF_ALLOC_DEBUG */
 
-    /* Retrieve metadata aggregator info, if available */
-    H5MF_aggr_query(f, &(f->shared->meta_aggr), &ma_addr, &ma_size);
-#ifdef H5MF_ALLOC_DEBUG
-HDfprintf(stderr, "%s: ma_addr = %a, ma_size = %Hu, end of ma = %a\n", FUNC, ma_addr, ma_size, (haddr_t)((ma_addr + ma_size) - 1));
-#endif /* H5MF_ALLOC_DEBUG */
+    if(H5F_PAGED_AGGR(f)) { /* File space paging */
+        H5F_mem_page_t ptype;		/* Memory type for iteration -- page fs */
 
-    /* Retrieve 'small data' aggregator info, if available */
-    H5MF_aggr_query(f, &(f->shared->sdata_aggr), &sda_addr, &sda_size);
-#ifdef H5MF_ALLOC_DEBUG
-HDfprintf(stderr, "%s: sda_addr = %a, sda_size = %Hu, end of sda = %a\n", FUNC, sda_addr, sda_size, (haddr_t)((sda_addr + sda_size) - 1));
-#endif /* H5MF_ALLOC_DEBUG */
-
-    /* Iterate over all the free space types that have managers and dump each free list's space */
-    for(type = H5FD_MEM_DEFAULT; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type)) {
-        /* Print header for type */
-        HDfprintf(stream, "%*sFile Free Space Info for type = %u:\n", indent, "", (unsigned)type);
-
-        /* Check for this type being mapped to another type */
-        if(H5FD_MEM_DEFAULT == f->shared->fs_type_map[type] ||
-                type == f->shared->fs_type_map[type]) {
-            /* Retrieve the 'eoa' for this file memory type */
-            if(HADDR_UNDEF == (eoa = H5F_get_eoa(f, type)))
-                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "driver get_eoa request failed")
-            HDfprintf(stream, "%*s%-*s %a\n", indent + 3, "", MAX(0, fwidth - 3), "eoa:", eoa);
+        for(ptype = H5F_MEM_PAGE_META; ptype < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, ptype)) {
+            /* Print header for type */
+            HDfprintf(stream, "%*sFile Free Space Info for type = %u:\n", indent, "", (unsigned)ptype);
 
             /* Print header for sections */
             HDfprintf(stream, "%*sSections:\n", indent + 3, "");
 
             /* If there is a free space manager for this type, iterate over them */
-            if(f->shared->fs_man[type]) {
+            if(f->shared->fs_man[ptype]) {
                 H5MF_debug_iter_ud_t udata;        /* User data for callbacks */
 
                 /* Prepare user data for section iteration callback */
-                udata.fspace = f->shared->fs_man[type];
+                udata.fspace = f->shared->fs_man[ptype];
                 udata.stream = stream;
                 udata.indent = indent + 6;
                 udata.fwidth = MAX(0, fwidth - 6);
 
                 /* Iterate over all the free space sections */
-                if(H5FS_sect_iterate(f, dxpl_id, f->shared->fs_man[type], H5MF_sects_debug_cb, &udata) < 0)
+                if(H5FS_sect_iterate(f, dxpl_id, f->shared->fs_man[ptype], H5MF_sects_debug_cb, &udata) < 0)
                     HGOTO_ERROR(H5E_HEAP, H5E_BADITER, FAIL, "can't iterate over heap's free space")
             } /* end if */
             else
                 /* No sections of this type */
                 HDfprintf(stream, "%*s<none>\n", indent + 6, "");
-        } /* end if */
-        else
-            HDfprintf(stream, "%*sMapped to type = %u\n", indent, "", (unsigned)f->shared->fs_type_map[type]);
+        } /* end for */
+    } /* end if */
+    else { /* not file space paging */
+        H5FD_mem_t atype;                   /* Memory type for iteration -- aggr fs */
+        haddr_t ma_addr = HADDR_UNDEF;      /* Base "metadata aggregator" address */
+        hsize_t ma_size = 0;                /* Size of "metadata aggregator" */
+        haddr_t sda_addr = HADDR_UNDEF;     /* Base "small data aggregator" address */
+        hsize_t sda_size = 0;               /* Size of "small data aggregator" */
+
+        /* Retrieve metadata aggregator info, if available */
+        H5MF_aggr_query(f, &(f->shared->meta_aggr), &ma_addr, &ma_size);
+#ifdef H5MF_ALLOC_DEBUG
+HDfprintf(stderr, "%s: ma_addr = %a, ma_size = %Hu, end of ma = %a\n", FUNC, ma_addr, ma_size, (haddr_t)((ma_addr + ma_size) - 1));
+#endif /* H5MF_ALLOC_DEBUG */
+
+        /* Retrieve 'small data' aggregator info, if available */
+        H5MF_aggr_query(f, &(f->shared->sdata_aggr), &sda_addr, &sda_size);
+#ifdef H5MF_ALLOC_DEBUG
+HDfprintf(stderr, "%s: sda_addr = %a, sda_size = %Hu, end of sda = %a\n", FUNC, sda_addr, sda_size, (haddr_t)((sda_addr + sda_size) - 1));
+#endif /* H5MF_ALLOC_DEBUG */
 
-    } /* end for */
+        /* Iterate over all the free space types that have managers and dump each free list's space */
+        for(atype = H5FD_MEM_DEFAULT; atype < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, atype)) {
+            /* Print header for type */
+            HDfprintf(stream, "%*sFile Free Space Info for type = %u:\n", indent, "", (unsigned)atype);
+
+            /* Check for this type being mapped to another type */
+            if(H5FD_MEM_DEFAULT == f->shared->fs_type_map[atype] || atype == f->shared->fs_type_map[atype]) {
+                /* Retrieve the 'eoa' for this file memory type */
+                if(HADDR_UNDEF == (eoa = H5F_get_eoa(f, atype)))
+                    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "driver get_eoa request failed")
+                HDfprintf(stream, "%*s%-*s %a\n", indent + 3, "", MAX(0, fwidth - 3), "eoa:", eoa);
+
+                /* Print header for sections */
+                HDfprintf(stream, "%*sSections:\n", indent + 3, "");
+
+                /* If there is a free space manager for this type, iterate over them */
+                if(f->shared->fs.aggr.fs_man[atype]) {
+                    H5MF_debug_iter_ud_t udata;        /* User data for callbacks */
+
+                    /* Prepare user data for section iteration callback */
+                    udata.fspace = f->shared->fs_man[atype];
+                    udata.stream = stream;
+                    udata.indent = indent + 6;
+                    udata.fwidth = MAX(0, fwidth - 6);
+
+                    /* Iterate over all the free space sections */
+                    if(H5FS_sect_iterate(f, dxpl_id, f->shared->fs_man[atype], H5MF_sects_debug_cb, &udata) < 0)
+                        HGOTO_ERROR(H5E_HEAP, H5E_BADITER, FAIL, "can't iterate over heap's free space")
+                } /* end if */
+                else /* No sections of this type */
+                    HDfprintf(stream, "%*s<none>\n", indent + 6, "");
+            } /* end if */
+            else
+                HDfprintf(stream, "%*sMapped to type = %u\n", indent, "", (unsigned)f->shared->fs_type_map[atype]);
+        } /* end for */
+    } /* end else */
 
 done:
 HDfprintf(stderr, "%s: Done dumping file free space sections\n", FUNC);
diff --git a/src/H5MFpkg.h b/src/H5MFpkg.h
index 43fc1cd..c4a0819 100644
--- a/src/H5MFpkg.h
+++ b/src/H5MFpkg.h
@@ -51,9 +51,38 @@
 /* Define this to dump free space tracker contents after they've been modified */
 /* #define H5MF_ALLOC_DEBUG_DUMP */
 
-/* Free space section types for file */
+/* Free-space section types for file */
 /* (values stored in free space data structures in file) */
-#define H5MF_FSPACE_SECT_SIMPLE         0       /* Section is a range of actual bytes in file */
+#define H5MF_FSPACE_SECT_SIMPLE     0   /* For non-paged aggregation: section is a range of actual bytes in file */
+#define H5MF_FSPACE_SECT_SMALL      1   /* For paged aggregation: "small" meta/raw data section which is < fsp_size) */
+#define H5MF_FSPACE_SECT_LARGE      2   /* For paged aggregation: "large" Section which is >= fsp_size) */
+
+/* For non-paged aggregation: map allocation request type to tracked free-space type */
+/* F -- pointer to H5F_t; T -- H5FD_mem_t */
+#define H5MF_ALLOC_TO_FS_AGGR_TYPE(F, T)                  \
+        ((H5FD_MEM_DEFAULT == (F)->shared->fs_type_map[T]) ? (T) : (F)->shared->fs_type_map[T])
+
+/* Get section class type based on size */
+#define H5MF_SECT_CLASS_TYPE(F, S)                          \
+        ((H5F_PAGED_AGGR(F)) ?                              \
+         ((S >= (F)->shared->fs_page_size) ? H5MF_FSPACE_SECT_LARGE : H5MF_FSPACE_SECT_SMALL) : H5MF_FSPACE_SECT_SIMPLE)
+
+/* Get section class cls */
+#define H5MF_SECT_CLS_TYPE(F, S)                            \
+        ((H5F_PAGED_AGGR(F)) ?                              \
+         ((S >= (F)->shared->fs_page_size) ?                \
+          H5MF_FSPACE_SECT_CLS_LARGE : H5MF_FSPACE_SECT_CLS_SMALL) : H5MF_FSPACE_SECT_CLS_SIMPLE)
+
+/* Calculate the mis-aligned fragment */
+#define H5MF_EOA_MISALIGN(F, E, A, FR)                                  \
+{                                                                       \
+    hsize_t m;                                                          \
+                                                                        \
+    if(H5F_addr_gt((E), 0) && ((m) = ((E) + H5F_BASE_ADDR(F)) % (A)))   \
+        (FR) = (A) - m;                                                 \
+    else                                                                \
+        (FR) = 0;                                                       \
+}
 
 
 /****************************/
@@ -129,6 +158,15 @@ typedef struct H5MF_sect_ud_t {
     H5F_blk_aggr_t *aggr;       /* Aggregator block to operate on */
 } H5MF_sect_ud_t;
 
+/* Information about the current free-space manager to use */
+typedef struct H5MF_fs_t {
+    H5F_fs_state_t *fs_state;
+    haddr_t *fs_addr;
+    H5FS_t **fs_man;
+    hsize_t     align_thres;	/* Threshold for alignment              */
+    hsize_t     alignment;      /* Alignment                            */
+} H5MF_fs_t;
+
 
 /*****************************/
 /* Package Private Variables */
@@ -136,6 +174,8 @@ typedef struct H5MF_sect_ud_t {
 
 /* H5MF single section inherits serializable properties from H5FS_section_class_t */
 H5_DLLVAR H5FS_section_class_t H5MF_FSPACE_SECT_CLS_SIMPLE[1];
+H5_DLLVAR H5FS_section_class_t H5MF_FSPACE_SECT_CLS_SMALL[1];
+H5_DLLVAR H5FS_section_class_t H5MF_FSPACE_SECT_CLS_LARGE[1];
 
 
 /******************************/
@@ -143,22 +183,23 @@ H5_DLLVAR H5FS_section_class_t H5MF_FSPACE_SECT_CLS_SIMPLE[1];
 /******************************/
 
 /* Allocator routines */
-H5_DLL herr_t H5MF__alloc_start(H5F_t *f, hid_t dxpl_id, H5FD_mem_t type);
-H5_DLL herr_t H5MF__alloc_open(H5F_t *f, hid_t dxpl_id, H5FD_mem_t type);
+H5_DLL herr_t H5MF_open_fstype(H5F_t *f, hid_t dxpl_id, H5F_mem_page_t type);
+H5_DLL herr_t H5MF_start_fstype(H5F_t *f, hid_t dxpl_id, H5F_mem_page_t type);
+
+H5_DLL htri_t H5MF_find_sect(H5F_t *f, H5FD_mem_t alloc_type, hid_t dxpl_id, hsize_t size, H5FS_t *fspace, haddr_t *addr);
+H5_DLL herr_t H5MF_add_sect(H5F_t *f, H5FD_mem_t alloc_type, hid_t dxpl_id, H5FS_t *fspace, H5MF_free_section_t *node);
+
 H5_DLL herr_t H5MF_sects_dump(H5F_t *f, hid_t dxpl_id, FILE *stream);
 
-/* 'simple' section routines */
-H5_DLL H5MF_free_section_t *H5MF_sect_simple_new(haddr_t sect_off,
+H5_DLL void H5MF_alloc_to_fs_type(H5F_t *f, H5FD_mem_t alloc_type, hsize_t size, H5F_mem_page_t *fs_type);
+
+/* 'simple/small/large' section routines */
+H5_DLL H5MF_free_section_t *H5MF_sect_new(unsigned ctype, haddr_t sect_off,
     hsize_t sect_size);
-H5_DLL htri_t H5MF_sect_simple_can_shrink(const H5FS_section_info_t *_sect,
-    void *udata);
-H5_DLL herr_t H5MF_sect_simple_shrink(H5FS_section_info_t **_sect,
-    void *udata);
-H5_DLL herr_t H5MF_sect_simple_free(H5FS_section_info_t *sect);
+H5_DLL herr_t H5MF_sect_free(H5FS_section_info_t *sect);
+
 
 /* Block aggregator routines */
-H5_DLL haddr_t H5MF_aggr_alloc(H5F_t *f, hid_t dxpl_id, H5F_blk_aggr_t *aggr,
-    H5F_blk_aggr_t *other_aggr, H5FD_mem_t type, hsize_t size);
 H5_DLL htri_t H5MF_aggr_try_extend(H5F_t *f, hid_t dxpl_id, H5F_blk_aggr_t *aggr,
     H5FD_mem_t type, haddr_t abs_blk_end, hsize_t extra_requested);
 H5_DLL htri_t H5MF_aggr_can_absorb(const H5F_t *f, const H5F_blk_aggr_t *aggr,
diff --git a/src/H5MFprivate.h b/src/H5MFprivate.h
index e258677..70322c3 100644
--- a/src/H5MFprivate.h
+++ b/src/H5MFprivate.h
@@ -58,8 +58,6 @@ H5_DLL herr_t H5MF_try_close(H5F_t *f, hid_t dxpl_id);
 /* File space allocation routines */
 H5_DLL haddr_t H5MF_alloc(H5F_t *f, H5FD_mem_t type, hid_t dxpl_id, hsize_t size);
 H5_DLL haddr_t H5MF_aggr_vfd_alloc(H5F_t *f, H5FD_mem_t type, hid_t dxpl_id, hsize_t size);
-H5_DLL haddr_t H5MF_vfd_alloc(H5F_t *f, hid_t dxpl_id, H5FD_mem_t alloc_type,
-    hsize_t size, hbool_t keep_fragment);
 H5_DLL herr_t H5MF_xfree(H5F_t *f, H5FD_mem_t type, hid_t dxpl_id, haddr_t addr,
     hsize_t size);
 H5_DLL herr_t H5MF_try_extend(H5F_t *f, hid_t dxpl_id, H5FD_mem_t type,
@@ -80,6 +78,14 @@ H5_DLL htri_t H5MF_aggrs_try_shrink_eoa(H5F_t *f, hid_t dxpl_id);
 H5_DLL herr_t H5MF_settle_raw_data_fsm(H5F_t *f, hid_t dxpl_id, hbool_t *fsm_settled);
 H5_DLL herr_t H5MF_settle_meta_data_fsm(H5F_t *f, hid_t dxpl_id, hbool_t *fsm_settled);
 
+/* This function has to be declared in H5MFprivate.h as it is needed 
+ * in our test code to allow us to manually start a self referential 
+ * free space manager prior to the first file space allocations / 
+ * deallocation without causing assertion failures on the first
+ * file space allocation / deallocation.
+ */
+H5_DLL herr_t H5MF_tidy_self_referential_fsm_hack(H5F_t *f, hid_t dxpl_id);
+
 /* Debugging routines */
 #ifdef H5MF_DEBUGGING
 H5_DLL herr_t H5MF_sects_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr,
diff --git a/src/H5MFsection.c b/src/H5MFsection.c
index e5a0cf0..617cb59 100644
--- a/src/H5MFsection.c
+++ b/src/H5MFsection.c
@@ -57,18 +57,47 @@
 /* Local Prototypes */
 /********************/
 
-/* 'simple' section callbacks */
-static H5FS_section_info_t *H5MF_sect_simple_deserialize(const H5FS_section_class_t *cls,
+/* 'simple/small/large' section callbacks */
+static H5FS_section_info_t *H5MF_sect_deserialize(const H5FS_section_class_t *cls,
     hid_t dxpl_id, const uint8_t *buf, haddr_t sect_addr, hsize_t sect_size,
     unsigned *des_flags);
+static herr_t H5MF_sect_valid(const H5FS_section_class_t *cls,
+    const H5FS_section_info_t *sect, hid_t dxpl_id);
+static H5FS_section_info_t *H5MF_sect_split(H5FS_section_info_t *sect,
+    hsize_t frag_size);
+
+
+/* 'simple' section callbacks */
 static htri_t H5MF_sect_simple_can_merge(const H5FS_section_info_t *sect1,
     const H5FS_section_info_t *sect2, void *udata);
-static herr_t H5MF_sect_simple_merge(H5FS_section_info_t *sect1,
+static herr_t H5MF_sect_simple_merge(H5FS_section_info_t **sect1,
     H5FS_section_info_t *sect2, void *udata);
-static herr_t H5MF_sect_simple_valid(const H5FS_section_class_t *cls,
-    const H5FS_section_info_t *sect, hid_t dxpl_id);
-static H5FS_section_info_t *H5MF_sect_simple_split(H5FS_section_info_t *sect,
-    hsize_t frag_size);
+static htri_t H5MF_sect_simple_can_shrink(const H5FS_section_info_t *_sect,
+    void *udata);
+static herr_t H5MF_sect_simple_shrink(H5FS_section_info_t **_sect,
+    void *udata);
+
+
+/* 'small' section callbacks */
+static herr_t H5MF_sect_small_add(H5FS_section_info_t **_sect, unsigned *flags, void *_udata);
+static htri_t H5MF_sect_small_can_merge(const H5FS_section_info_t *sect1,
+    const H5FS_section_info_t *sect2, void *udata);
+static herr_t H5MF_sect_small_merge(H5FS_section_info_t **sect1,
+    H5FS_section_info_t *sect2, void *udata);
+static htri_t H5MF_sect_small_can_shrink(const H5FS_section_info_t *_sect,
+    void *udata);
+static herr_t H5MF_sect_small_shrink(H5FS_section_info_t **_sect,
+    void *udata);
+
+/* 'large' section callbacks */
+static htri_t H5MF_sect_large_can_merge(const H5FS_section_info_t *sect1,
+    const H5FS_section_info_t *sect2, void *udata);
+static herr_t H5MF_sect_large_merge(H5FS_section_info_t **sect1,
+    H5FS_section_info_t *sect2, void *udata);
+static htri_t H5MF_sect_large_can_shrink(const H5FS_section_info_t *_sect,
+    void *udata);
+static herr_t H5MF_sect_large_shrink(H5FS_section_info_t **_sect,
+    void *udata);
 
 /*********************/
 /* Package Variables */
@@ -89,17 +118,68 @@ H5FS_section_class_t H5MF_FSPACE_SECT_CLS_SIMPLE[1] = {{
     /* Object methods */
     NULL,				/* Add section                  */
     NULL,				/* Serialize section            */
-    H5MF_sect_simple_deserialize,	/* Deserialize section          */
+    H5MF_sect_deserialize,		/* Deserialize section          */
     H5MF_sect_simple_can_merge,		/* Can sections merge?          */
     H5MF_sect_simple_merge,		/* Merge sections               */
     H5MF_sect_simple_can_shrink,	/* Can section shrink container?*/
     H5MF_sect_simple_shrink,		/* Shrink container w/section   */
-    H5MF_sect_simple_free,		/* Free section                 */
-    H5MF_sect_simple_valid,		/* Check validity of section    */
-    H5MF_sect_simple_split,		/* Split section node for alignment */
+    H5MF_sect_free,			/* Free section                 */
+    H5MF_sect_valid,			/* Check validity of section    */
+    H5MF_sect_split,			/* Split section node for alignment */
     NULL,				/* Dump debugging for section   */
 }};
 
+/* Class info for "small" free space sections */
+H5FS_section_class_t H5MF_FSPACE_SECT_CLS_SMALL[1] = {{
+    /* Class variables */
+    H5MF_FSPACE_SECT_SMALL,		/* Section type                 */
+    0,					/* Extra serialized size        */
+    H5FS_CLS_MERGE_SYM | H5FS_CLS_ADJUST_OK, /* Class flags                  */
+    NULL,				/* Class private info           */
+
+    /* Class methods */
+    NULL,				/* Initialize section class     */
+    NULL,				/* Terminate section class      */
+
+    /* Object methods */
+    H5MF_sect_small_add,		/* Add section                  */
+    NULL,				/* Serialize section            */
+    H5MF_sect_deserialize,		/* Deserialize section          */
+    H5MF_sect_small_can_merge,		/* Can sections merge?          */
+    H5MF_sect_small_merge,		/* Merge sections               */
+    H5MF_sect_small_can_shrink,		/* Can section shrink container?*/
+    H5MF_sect_small_shrink,		/* Shrink container w/section   */
+    H5MF_sect_free,			/* Free section                 */
+    H5MF_sect_valid,			/* Check validity of section    */
+    H5MF_sect_split,			/* Split section node for alignment */
+    NULL,				/* Dump debugging for section   */
+}};
+
+/* Class info for "large" free space sections */
+H5FS_section_class_t H5MF_FSPACE_SECT_CLS_LARGE[1] = {{
+    /* Class variables */
+    H5MF_FSPACE_SECT_LARGE,		/* Section type                 */
+    0,					/* Extra serialized size        */
+    H5FS_CLS_MERGE_SYM | H5FS_CLS_ADJUST_OK, /* Class flags                  */
+    NULL,				/* Class private info           */
+
+    /* Class methods */
+    NULL,				/* Initialize section class     */
+    NULL,				/* Terminate section class      */
+
+    /* Object methods */
+    NULL,				/* Add section                  */
+    NULL,				/* Serialize section            */
+    H5MF_sect_deserialize,		/* Deserialize section          */
+    H5MF_sect_large_can_merge,		/* Can sections merge?          */
+    H5MF_sect_large_merge,		/* Merge sections               */
+    H5MF_sect_large_can_shrink,		/* Can section shrink container?*/
+    H5MF_sect_large_shrink,		/* Shrink container w/section   */
+    H5MF_sect_free,			/* Free section                 */
+    H5MF_sect_valid,			/* Check validity of section    */
+    H5MF_sect_split,			/* Split section node for alignment */
+    NULL,				/* Dump debugging for section   */
+}};
 
 /*****************************/
 /* Library Private Variables */
@@ -113,12 +193,15 @@ H5FS_section_class_t H5MF_FSPACE_SECT_CLS_SIMPLE[1] = {{
 /* Declare a free list to manage the H5MF_free_section_t struct */
 H5FL_DEFINE(H5MF_free_section_t);
 
+/* 
+ * "simple/small/large" section callbacks
+ */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5MF_sect_simple_new
+ * Function:	H5MF_sect_new
  *
- * Purpose:	Create a new 'simple' section and return it to the caller
+ * Purpose:	Create a new section of "ctype" and return it to the caller
  *
  * Return:	Pointer to new section on success/NULL on failure
  *
@@ -129,9 +212,9 @@ H5FL_DEFINE(H5MF_free_section_t);
  *-------------------------------------------------------------------------
  */
 H5MF_free_section_t *
-H5MF_sect_simple_new(haddr_t sect_off, hsize_t sect_size)
+H5MF_sect_new(unsigned ctype, haddr_t sect_off, hsize_t sect_size)
 {
-    H5MF_free_section_t *sect = NULL;   /* 'Simple' free space section to add */
+    H5MF_free_section_t *sect;          /* 'Simple' free space section to add */
     H5MF_free_section_t *ret_value = NULL;      /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
@@ -148,7 +231,7 @@ H5MF_sect_simple_new(haddr_t sect_off, hsize_t sect_size)
     sect->sect_info.size = sect_size;
 
     /* Set the section's class & state */
-    sect->sect_info.type = H5MF_FSPACE_SECT_SIMPLE;
+    sect->sect_info.type = ctype;
     sect->sect_info.state = H5FS_SECT_LIVE;
 
     /* Set return value */
@@ -156,13 +239,43 @@ H5MF_sect_simple_new(haddr_t sect_off, hsize_t sect_size)
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5MF_sect_simple_new() */
+} /* end H5MF_sect_new() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5MF_sect_simple_deserialize
+ * Function:	H5MF_sect_free
  *
- * Purpose:	Deserialize a buffer into a "live" single section
+ * Purpose:	Free a 'simple/small/large' section node
+ *
+ * Return:	Success:	non-negative
+ *		Failure:	negative
+ *
+ * Programmer:	Quincey Koziol
+ *              Tuesday, January  8, 2008
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5MF_sect_free(H5FS_section_info_t *_sect)
+{
+    H5MF_free_section_t *sect = (H5MF_free_section_t *)_sect;   /* File free section */
+
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    /* Check arguments. */
+    HDassert(sect);
+
+    /* Release the section */
+    sect = H5FL_FREE(H5MF_free_section_t, sect);
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+}   /* H5MF_sect_free() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5MF_sect_deserialize
+ *
+ * Purpose:	Deserialize a buffer into a "live" section
  *
  * Return:	Success:	non-negative
  *		Failure:	negative
@@ -173,7 +286,7 @@ done:
  *-------------------------------------------------------------------------
  */
 static H5FS_section_info_t *
-H5MF_sect_simple_deserialize(const H5FS_section_class_t H5_ATTR_UNUSED *cls,
+H5MF_sect_deserialize(const H5FS_section_class_t *cls,
     hid_t H5_ATTR_UNUSED dxpl_id, const uint8_t H5_ATTR_UNUSED *buf, haddr_t sect_addr,
     hsize_t sect_size, unsigned H5_ATTR_UNUSED *des_flags)
 {
@@ -183,11 +296,12 @@ H5MF_sect_simple_deserialize(const H5FS_section_class_t H5_ATTR_UNUSED *cls,
     FUNC_ENTER_NOAPI_NOINIT
 
     /* Check arguments. */
+    HDassert(cls);
     HDassert(H5F_addr_defined(sect_addr));
     HDassert(sect_size);
 
     /* Create free space section for block */
-    if(NULL == (sect = H5MF_sect_simple_new(sect_addr, sect_size)))
+    if(NULL == (sect = H5MF_sect_new(cls->type, sect_addr, sect_size)))
         HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, NULL, "can't initialize free space section")
 
     /* Set return value */
@@ -195,10 +309,80 @@ H5MF_sect_simple_deserialize(const H5FS_section_class_t H5_ATTR_UNUSED *cls,
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* H5MF_sect_simple_deserialize() */
+} /* H5MF_sect_deserialize() */
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5MF_sect_valid
+ *
+ * Purpose:	Check the validity of a section
+ *
+ * Return:	Success:	non-negative
+ *          Failure:	negative
+ *
+ * Programmer:	Quincey Koziol
+ *              Tuesday, January  8, 2008
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5MF_sect_valid(const H5FS_section_class_t H5_ATTR_UNUSED *cls,
+    const H5FS_section_info_t
+#ifdef NDEBUG
+    H5_ATTR_UNUSED
+#endif /* NDEBUG */
+    *_sect, hid_t H5_ATTR_UNUSED dxpl_id)
+{
+#ifndef NDEBUG
+    const H5MF_free_section_t *sect = (const H5MF_free_section_t *)_sect;   /* File free section */
+#endif /* NDEBUG */
+
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    /* Check arguments. */
+    HDassert(sect);
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+}   /* H5MF_sect_valid() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5MF_sect_split
+ *
+ * Purpose:	Split SECT into 2 sections: fragment for alignment & the aligned section
+ *          SECT's addr and size are updated to point to the aligned section
+ *
+ * Return:	Success:	the fragment for aligning sect
+ *          Failure:	null
+ *
+ * Programmer:	Vailin Choi, July 29, 2008
+ *
+ *-------------------------------------------------------------------------
+ */
+static H5FS_section_info_t *
+H5MF_sect_split(H5FS_section_info_t *sect, hsize_t frag_size)
+{
+    H5MF_free_section_t *ret_value;     /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    /* Allocate space for new section */
+    if(NULL == (ret_value = H5MF_sect_new(sect->type, sect->addr, frag_size)))
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, NULL, "can't initialize free space section")
+
+    /* Set new section's info */
+    sect->addr += frag_size;
+    sect->size -= frag_size;
+
+done:
+    FUNC_LEAVE_NOAPI((H5FS_section_info_t *)ret_value)
+} /* end H5MF_sect_split() */
+
+/* 
+ * "simple" section callbacks
+ */
+
+/*-------------------------------------------------------------------------
  * Function:	H5MF_sect_simple_can_merge
  *
  * Purpose:	Can two sections of this type merge?
@@ -252,10 +436,10 @@ H5MF_sect_simple_can_merge(const H5FS_section_info_t *_sect1,
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5MF_sect_simple_merge(H5FS_section_info_t *_sect1, H5FS_section_info_t *_sect2,
+H5MF_sect_simple_merge(H5FS_section_info_t **_sect1, H5FS_section_info_t *_sect2,
     void H5_ATTR_UNUSED *_udata)
 {
-    H5MF_free_section_t *sect1 = (H5MF_free_section_t *)_sect1;   /* File free section */
+    H5MF_free_section_t **sect1 = (H5MF_free_section_t **)_sect1;   /* File free section */
     H5MF_free_section_t *sect2 = (H5MF_free_section_t *)_sect2;   /* File free section */
     herr_t ret_value = SUCCEED;         /* Return value */
 
@@ -263,16 +447,16 @@ H5MF_sect_simple_merge(H5FS_section_info_t *_sect1, H5FS_section_info_t *_sect2,
 
     /* Check arguments. */
     HDassert(sect1);
-    HDassert(sect1->sect_info.type == H5MF_FSPACE_SECT_SIMPLE);
+    HDassert((*sect1)->sect_info.type == H5MF_FSPACE_SECT_SIMPLE);
     HDassert(sect2);
     HDassert(sect2->sect_info.type == H5MF_FSPACE_SECT_SIMPLE);
-    HDassert(H5F_addr_eq(sect1->sect_info.addr + sect1->sect_info.size, sect2->sect_info.addr));
+    HDassert(H5F_addr_eq((*sect1)->sect_info.addr + (*sect1)->sect_info.size, sect2->sect_info.addr));
 
     /* Add second section's size to first section */
-    sect1->sect_info.size += sect2->sect_info.size;
+    (*sect1)->sect_info.size += sect2->sect_info.size;
 
     /* Get rid of second section */
-    if(H5MF_sect_simple_free((H5FS_section_info_t *)sect2) < 0)
+    if(H5MF_sect_free((H5FS_section_info_t *)sect2) < 0)
         HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't free section node")
 
 done:
@@ -293,7 +477,7 @@ done:
  *
  *-------------------------------------------------------------------------
  */
-htri_t
+static htri_t
 H5MF_sect_simple_can_shrink(const H5FS_section_info_t *_sect, void *_udata)
 {
     const H5MF_free_section_t *sect = (const H5MF_free_section_t *)_sect;   /* File free section */
@@ -392,7 +576,7 @@ done:
  *
  *-------------------------------------------------------------------------
  */
-herr_t
+static herr_t
 H5MF_sect_simple_shrink(H5FS_section_info_t **_sect, void *_udata)
 {
     H5MF_free_section_t **sect = (H5MF_free_section_t **)_sect;   /* File free section */
@@ -411,8 +595,8 @@ H5MF_sect_simple_shrink(H5FS_section_info_t **_sect, void *_udata)
         /* Sanity check */
         HDassert(H5F_INTENT(udata->f) & H5F_ACC_RDWR);
 
-        /* Release section's space at EOA with file driver */
-        if(H5FD_free(udata->f->shared->lf, udata->dxpl_id, udata->alloc_type, udata->f, (*sect)->sect_info.addr, (*sect)->sect_info.size) < 0)
+        /* Release section's space at EOA */
+        if(H5F_free(udata->f, udata->dxpl_id, udata->alloc_type, (*sect)->sect_info.addr, (*sect)->sect_info.size) < 0)
             HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, FAIL, "driver free request failed")
     } /* end if */
     else {
@@ -427,7 +611,7 @@ H5MF_sect_simple_shrink(H5FS_section_info_t **_sect, void *_udata)
     /* Check for freeing section */
     if(udata->shrink != H5MF_SHRINK_SECT_ABSORB_AGGR) {
         /* Free section */
-        if(H5MF_sect_simple_free((H5FS_section_info_t *)*sect) < 0)
+        if(H5MF_sect_free((H5FS_section_info_t *)*sect) < 0)
             HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't free simple section node")
 
         /* Mark section as freed, for free space manager */
@@ -438,100 +622,474 @@ done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* H5MF_sect_simple_shrink() */
 
+/* 
+ * "small" section callbacks
+ */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5MF_sect_small_add
+ *
+ * Purpose:     Perform actions on a small "meta" action before adding it to the free space manager:
+ *              1) Drop the section if it is at page end and its size <= page end threshold
+ *              2) Adjust section size to include page end threshold if 
+ *                 (section size + threshold) is at page end
+ *
+ * Return:      Success:        non-negative
+ *              Failure:        negative
+ *
+ * Programmer:  Vailin Choi; Dec 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5MF_sect_small_add(H5FS_section_info_t **_sect, unsigned *flags, void *_udata)
+{
+    H5MF_free_section_t **sect = (H5MF_free_section_t **)_sect;   /* Fractal heap free section */
+    H5MF_sect_ud_t *udata = (H5MF_sect_ud_t *)_udata;   /* User data for callback */
+    haddr_t sect_end;
+    hsize_t rem, prem;
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+#ifdef H5MF_ALLOC_DEBUG_MORE
+HDfprintf(stderr, "%s: Entering, section {%a, %Hu}\n", FUNC, (*sect)->sect_info.addr, (*sect)->sect_info.size);
+#endif /* H5MF_ALLOC_DEBUG_MORE */
+
+    /* Do not adjust the section raw data or global heap data */
+    if(udata->alloc_type == H5FD_MEM_DRAW || udata->alloc_type == H5FD_MEM_GHEAP)
+        HGOTO_DONE(ret_value);
+
+    sect_end = (*sect)->sect_info.addr + (*sect)->sect_info.size;
+    rem = sect_end % udata->f->shared->fs_page_size;
+    prem = udata->f->shared->fs_page_size - rem;
+
+    /* Drop the section if it is at page end and its size is <= pgend threshold */
+    if(!rem && (*sect)->sect_info.size <= H5F_PGEND_META_THRES(udata->f) && (*flags & H5FS_ADD_RETURNED_SPACE)) {
+        if(H5MF_sect_free((H5FS_section_info_t *)(*sect)) < 0)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't free section node")
+        *sect = NULL;
+        *flags &= (unsigned)~H5FS_ADD_RETURNED_SPACE;
+        *flags |= H5FS_PAGE_END_NO_ADD;
+#ifdef H5MF_ALLOC_DEBUG_MORE
+HDfprintf(stderr, "%s: section is dropped\n", FUNC);
+#endif /* H5MF_ALLOC_DEBUG_MORE */
+    } /* end if */
+    /* Adjust the section if it is not at page end but its size + pgend threshold is at page end */
+    else
+        if(prem <= H5F_PGEND_META_THRES(udata->f)) {
+            (*sect)->sect_info.size += prem;
+#ifdef H5MF_ALLOC_DEBUG_MORE
+HDfprintf(stderr, "%s: section is adjusted {%a, %Hu}\n", FUNC, (*sect)->sect_info.addr, (*sect)->sect_info.size);
+#endif /* H5MF_ALLOC_DEBUG_MORE */
+        } /* end if */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5MF_sect_small_add() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5MF_sect_small_can_shrink
+ *
+ * Purpose:	Can this section shrink the container?
+ *
+ * Note: 	A small section is allowed to shrink only at closing.
+ *
+ * Return:	Success:	non-negative (TRUE/FALSE)
+ *          Failure:	negative
+ *
+ * Programmer:	Vailin Choi; Dec 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+static htri_t
+H5MF_sect_small_can_shrink(const H5FS_section_info_t *_sect, void *_udata)
+{
+    const H5MF_free_section_t *sect = (const H5MF_free_section_t *)_sect;   /* File free section */
+    H5MF_sect_ud_t *udata = (H5MF_sect_ud_t *)_udata;   /* User data for callback */
+    haddr_t eoa;                /* End of address space in the file */
+    haddr_t end;                /* End of section to extend */
+    htri_t ret_value = FALSE;	/* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    /* Check arguments. */
+    HDassert(sect);
+    HDassert(udata);
+    HDassert(udata->f);
+
+    /* Retrieve the end of the file's address space */
+    if(HADDR_UNDEF == (eoa = H5FD_get_eoa(udata->f->shared->lf, udata->alloc_type)))
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "driver get_eoa request failed")
+
+    /* Compute address of end of section to check */
+    end = sect->sect_info.addr + sect->sect_info.size;
+
+    /* Check if the section is exactly at the end of the allocated space in the file */
+    if(H5F_addr_eq(end, eoa) && sect->sect_info.size == udata->f->shared->fs_page_size) {
+        udata->shrink = H5MF_SHRINK_EOA;
+
+#ifdef H5MF_ALLOC_DEBUG_MORE
+HDfprintf(stderr, "%s: section {%a, %Hu}, shrinks file, eoa = %a\n", FUNC, sect->sect_info.addr, sect->sect_info.size, eoa);
+#endif /* H5MF_ALLOC_DEBUG_MORE */
+
+        /* Indicate shrinking can occur */
+        HGOTO_DONE(TRUE)
+    } /* end if */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5MF_sect_small_can_shrink() */
+
 
 /*-------------------------------------------------------------------------
- * Function:	H5MF_sect_simple_free
+ * Function:	H5MF_sect_small_shrink
  *
- * Purpose:	Free a 'single' section node
+ * Purpose:	Shrink container with section
  *
  * Return:	Success:	non-negative
- *		Failure:	negative
+ *          Failure:	negative 
+ * 
+ * Programmer:	Vailin Choi; Dec 2012
  *
- * Programmer:	Quincey Koziol
- *              Tuesday, January  8, 2008
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5MF_sect_small_shrink(H5FS_section_info_t **_sect, void *_udata)
+{
+    H5MF_free_section_t **sect = (H5MF_free_section_t **)_sect;   /* File free section */
+    H5MF_sect_ud_t *udata = (H5MF_sect_ud_t *)_udata;   /* User data for callback */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    /* Check arguments. */
+    HDassert(sect);
+    HDassert((*sect)->sect_info.type == H5MF_FSPACE_SECT_SMALL);
+    HDassert(udata);
+    HDassert(udata->f);
+    HDassert(udata->shrink == H5MF_SHRINK_EOA);
+    HDassert(H5F_INTENT(udata->f) & H5F_ACC_RDWR);
+
+    /* Release section's space at EOA */
+    if(H5F_free(udata->f, udata->dxpl_id, udata->alloc_type, (*sect)->sect_info.addr, (*sect)->sect_info.size) < 0)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, FAIL, "driver free request failed")
+
+    /* Free section */
+    if(H5MF_sect_free((H5FS_section_info_t *)*sect) < 0)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't free simple section node")
+
+    /* Mark section as freed, for free space manager */
+    *sect = NULL;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5MF_sect_small_shrink() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5MF_sect_small_can_merge
+ *
+ * Purpose:	Can two sections of this type merge?
+ *
+ * Note: Second section must be "after" first section
+ *       The "merged" section cannot cross page boundary.
+ *
+ * Return:	Success:	non-negative (TRUE/FALSE)
+ *          Failure:	negative
+ *
+ * Programmer:	Vailin Choi; Dec 2012
  *
  *-------------------------------------------------------------------------
  */
-herr_t
-H5MF_sect_simple_free(H5FS_section_info_t *_sect)
+static htri_t
+H5MF_sect_small_can_merge(const H5FS_section_info_t *_sect1,
+    const H5FS_section_info_t *_sect2, void *_udata)
 {
-    H5MF_free_section_t *sect = (H5MF_free_section_t *)_sect;   /* File free section */
+    const H5MF_free_section_t *sect1 = (const H5MF_free_section_t *)_sect1;   /* File free section */
+    const H5MF_free_section_t *sect2 = (const H5MF_free_section_t *)_sect2;   /* File free section */
+    H5MF_sect_ud_t *udata = (H5MF_sect_ud_t *)_udata;   /* User data for callback */
+    htri_t ret_value = FALSE;                   	/* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT_NOERR
 
     /* Check arguments. */
-    HDassert(sect);
+    HDassert(sect1);
+    HDassert(sect2);
+    HDassert(sect1->sect_info.type == sect2->sect_info.type);   /* Checks "MERGE_SYM" flag */
+    HDassert(H5F_addr_lt(sect1->sect_info.addr, sect2->sect_info.addr));
 
-    /* Release the section */
-    sect = H5FL_FREE(H5MF_free_section_t, sect);
+    /* Check if second section adjoins first section */
+    ret_value = H5F_addr_eq(sect1->sect_info.addr + sect1->sect_info.size, sect2->sect_info.addr);
+    if(ret_value > 0)
+        /* If they are on different pages, couldn't merge */
+        if((sect1->sect_info.addr / udata->f->shared->fs_page_size) != (((sect2->sect_info.addr + sect2->sect_info.size - 1) / udata->f->shared->fs_page_size)))
+	    ret_value = FALSE;
 
-    FUNC_LEAVE_NOAPI(SUCCEED)
-}   /* H5MF_sect_simple_free() */
+#ifdef H5MF_ALLOC_DEBUG_MORE
+HDfprintf(stderr, "%s: Leaving: ret_value = %t\n", FUNC, ret_value);
+#endif /* H5MF_ALLOC_DEBUG_MORE */
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5MF_sect_small_can_merge() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5MF_sect_simple_valid
+ * Function:	H5MF_sect_small_merge
  *
- * Purpose:	Check the validity of a section
+ * Purpose:	Merge two sections of this type
+ *
+ * Note: Second section always merges into first node.
+ *       If the size of the "merged" section is equal to file space page size,
+ *       free the section.
  *
  * Return:	Success:	non-negative
  *		Failure:	negative
  *
- * Programmer:	Quincey Koziol
- *              Tuesday, January  8, 2008
+ * Programmer:	Vailin Choi; Dec 2012
  *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5MF_sect_simple_valid(const H5FS_section_class_t H5_ATTR_UNUSED *cls,
-    const H5FS_section_info_t
-#ifdef NDEBUG
-    H5_ATTR_UNUSED
-#endif /* NDEBUG */
-    *_sect, hid_t H5_ATTR_UNUSED dxpl_id)
+H5MF_sect_small_merge(H5FS_section_info_t **_sect1, H5FS_section_info_t *_sect2,
+    void *_udata)
 {
-#ifndef NDEBUG
-    const H5MF_free_section_t *sect = (const H5MF_free_section_t *)_sect;   /* File free section */
-#endif /* NDEBUG */
+    H5MF_free_section_t **sect1 = (H5MF_free_section_t **)_sect1;   /* File free section */
+    H5MF_free_section_t *sect2 = (H5MF_free_section_t *)_sect2;   /* File free section */
+    H5MF_sect_ud_t *udata = (H5MF_sect_ud_t *)_udata;   /* User data for callback */
+    herr_t ret_value = SUCCEED;         		/* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    /* Check arguments. */
+    HDassert(sect1);
+    HDassert((*sect1)->sect_info.type == H5MF_FSPACE_SECT_SMALL);
+    HDassert(sect2);
+    HDassert(sect2->sect_info.type == H5MF_FSPACE_SECT_SMALL);
+    HDassert(H5F_addr_eq((*sect1)->sect_info.addr + (*sect1)->sect_info.size, sect2->sect_info.addr));
+
+    /* Add second section's size to first section */
+    (*sect1)->sect_info.size += sect2->sect_info.size;
+
+    if((*sect1)->sect_info.size == udata->f->shared->fs_page_size) {
+        if(H5MF_xfree(udata->f, udata->alloc_type, udata->dxpl_id, (*sect1)->sect_info.addr, (*sect1)->sect_info.size) < 0)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, FAIL, "can't free merged section")
+
+        /* Need to free possible metadata page in the PB cache */
+        /* This is in response to the data corruption bug from fheap.c with page buffering + page strategy */
+        /* Note: Large metadata page bypasses the PB cache */
+        /* Note: Update of raw data page (large or small sized) is handled by the PB cache */
+        if(udata->f->shared->page_buf != NULL && udata->alloc_type != H5FD_MEM_DRAW)
+            if(H5PB_remove_entry(udata->f, (*sect1)->sect_info.addr) < 0)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, FAIL, "can't free merged section")
+
+        if(H5MF_sect_free((H5FS_section_info_t *)(*sect1)) < 0)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't free section node")
+        *sect1 = NULL;
+    } /* end if */
+
+    /* Get rid of second section */
+    if(H5MF_sect_free((H5FS_section_info_t *)sect2) < 0)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't free section node")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5MF_sect_small_merge() */
+
+/* 
+ * "Large" section callbacks
+ */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5MF_sect_large_can_merge (same as H5MF_sect_simple_can_merge)
+ *
+ * Purpose:	Can two sections of this type merge?
+ *
+ * Note: Second section must be "after" first section
+ *
+ * Return:	Success:	non-negative (TRUE/FALSE)
+ *          Failure:	negative
+ *
+ * Programmer:	Vailin Choi; Dec 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+static htri_t
+H5MF_sect_large_can_merge(const H5FS_section_info_t *_sect1,
+    const H5FS_section_info_t *_sect2, void H5_ATTR_UNUSED *_udata)
+{
+    const H5MF_free_section_t *sect1 = (const H5MF_free_section_t *)_sect1;   	/* File free section */
+    const H5MF_free_section_t *sect2 = (const H5MF_free_section_t *)_sect2;   	/* File free section */
+    htri_t ret_value = FALSE;           /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT_NOERR
 
     /* Check arguments. */
+    HDassert(sect1);
+    HDassert(sect2);
+    HDassert(sect1->sect_info.type == sect2->sect_info.type);   /* Checks "MERGE_SYM" flag */
+    HDassert(H5F_addr_lt(sect1->sect_info.addr, sect2->sect_info.addr));
+
+    ret_value = H5F_addr_eq(sect1->sect_info.addr + sect1->sect_info.size, sect2->sect_info.addr);
+
+#ifdef H5MF_ALLOC_DEBUG_MORE
+HDfprintf(stderr, "%s: Leaving: ret_value = %t\n", FUNC, ret_value);
+#endif /* H5MF_ALLOC_DEBUG_MORE */
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5MF_sect_large_can_merge() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5MF_sect_large_merge (same as H5MF_sect_simple_merge)
+ *
+ * Purpose:	Merge two sections of this type
+ *
+ * Note: Second section always merges into first node
+ *
+ * Return:	Success:	non-negative
+ *          Failure:	negative
+ *
+ * Programmer:	Vailin Choi; Dec 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5MF_sect_large_merge(H5FS_section_info_t **_sect1, H5FS_section_info_t *_sect2,
+    void H5_ATTR_UNUSED *_udata)
+{
+    H5MF_free_section_t **sect1 = (H5MF_free_section_t **)_sect1;   /* File free section */
+    H5MF_free_section_t *sect2 = (H5MF_free_section_t *)_sect2;   /* File free section */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    /* Check arguments. */
+    HDassert(sect1);
+    HDassert((*sect1)->sect_info.type == H5MF_FSPACE_SECT_LARGE);
+    HDassert(sect2);
+    HDassert(sect2->sect_info.type == H5MF_FSPACE_SECT_LARGE);
+    HDassert(H5F_addr_eq((*sect1)->sect_info.addr + (*sect1)->sect_info.size, sect2->sect_info.addr));
+
+    /* Add second section's size to first section */
+    (*sect1)->sect_info.size += sect2->sect_info.size;
+
+    /* Get rid of second section */
+    if(H5MF_sect_free((H5FS_section_info_t *)sect2) < 0)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't free section node")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5MF_sect_large_merge() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5MF_sect_large_can_shrink
+ *
+ * Purpose:	Can this section shrink the container?
+ *
+ * Return:	Success:	non-negative (TRUE/FALSE)
+ *          Failure:	negative
+ *
+ * Programmer:	Vailin Choi; Dec 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+static htri_t
+H5MF_sect_large_can_shrink(const H5FS_section_info_t *_sect, void *_udata)
+{
+    const H5MF_free_section_t *sect = (const H5MF_free_section_t *)_sect;   /* File free section */
+    H5MF_sect_ud_t *udata = (H5MF_sect_ud_t *)_udata;   /* User data for callback */
+    haddr_t eoa;                /* End of address space in the file */
+    haddr_t end;                /* End of section to extend */
+    htri_t ret_value = FALSE;	/* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    /* Check arguments. */
     HDassert(sect);
+    HDassert(sect->sect_info.type == H5MF_FSPACE_SECT_LARGE);
+    HDassert(udata);
+    HDassert(udata->f);
 
-    FUNC_LEAVE_NOAPI(SUCCEED)
-}   /* H5MF_sect_simple_valid() */
+    /* Retrieve the end of the file's address space */
+    if(HADDR_UNDEF == (eoa = H5FD_get_eoa(udata->f->shared->lf, udata->alloc_type)))
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "driver get_eoa request failed")
+
+    /* Compute address of end of section to check */
+    end = sect->sect_info.addr + sect->sect_info.size;
+
+    /* Check if the section is exactly at the end of the allocated space in the file */
+    if(H5F_addr_eq(end, eoa) && sect->sect_info.size >= udata->f->shared->fs_page_size) {
+        /* Set the shrinking type */
+        udata->shrink = H5MF_SHRINK_EOA;
+#ifdef H5MF_ALLOC_DEBUG_MORE
+HDfprintf(stderr, "%s: section {%a, %Hu}, shrinks file, eoa = %a\n", FUNC, sect->sect_info.addr, sect->sect_info.size, eoa);
+#endif /* H5MF_ALLOC_DEBUG_MORE */
 
+        /* Indicate shrinking can occur */
+        HGOTO_DONE(TRUE)
+    } /* end if */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5MF_sect_large_can_shrink() */
 
+
 /*-------------------------------------------------------------------------
- * Function:	H5MF_sect_simple_split
+ * Function:	H5MF_sect_large_shrink
  *
- * Purpose:	Split SECT into 2 sections: fragment for alignment & the aligned section
- *		SECT's addr and size are updated to point to the aligned section
+ * Purpose:     Shrink a large-sized section
  *
- * Return:	Success:	the fragment for aligning sect
- *		Failure:	null
+ * Return:      Success:	non-negative
+ *              Failure:	negative
  *
- * Programmer:	Vailin Choi, July 29, 2008
+ * Programmer:	Vailin Choi; Dec 2012
  *
  *-------------------------------------------------------------------------
  */
-static H5FS_section_info_t *
-H5MF_sect_simple_split(H5FS_section_info_t *sect, hsize_t frag_size)
+static herr_t
+H5MF_sect_large_shrink(H5FS_section_info_t **_sect, void *_udata)
 {
-    H5MF_free_section_t *ret_value = NULL;      /* Return value */
+    H5MF_free_section_t **sect = (H5MF_free_section_t **)_sect; /* File free section */
+    H5MF_sect_ud_t *udata = (H5MF_sect_ud_t *)_udata;           /* User data for callback */
+    hsize_t frag_size = 0;              /* Fragment size */
+    herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
 
-    /* Allocate space for new section */
-    if(NULL == (ret_value = H5MF_sect_simple_new(sect->addr, frag_size)))
-        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTALLOC, NULL, "can't initialize free space section")
+    /* Check arguments. */
+    HDassert(sect);
+    HDassert((*sect)->sect_info.type == H5MF_FSPACE_SECT_LARGE);
+    HDassert(udata);
+    HDassert(udata->f);
+    HDassert(udata->shrink == H5MF_SHRINK_EOA);
+    HDassert(H5F_INTENT(udata->f) & H5F_ACC_RDWR);
+    HDassert(H5F_PAGED_AGGR(udata->f));
 
-    /* Set new section's info */
-    sect->addr += frag_size;
-    sect->size -= frag_size;
+    /* Calculate possible mis-aligned fragment */
+    H5MF_EOA_MISALIGN(udata->f, (*sect)->sect_info.addr, udata->f->shared->fs_page_size, frag_size);
+
+    /* Free full pages from EOA */
+    /* Retain partial page in the free-space manager so as to keep EOA at page boundary */
+    if(H5F_free(udata->f, udata->dxpl_id, udata->alloc_type, (*sect)->sect_info.addr+frag_size, (*sect)->sect_info.size-frag_size) < 0)
+        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, FAIL, "driver free request failed")
+
+    if(frag_size) /* Adjust section size for the partial page */
+        (*sect)->sect_info.size = frag_size;
+    else {
+        /* Free section */
+        if(H5MF_sect_free((H5FS_section_info_t *)*sect) < 0)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTRELEASE, FAIL, "can't free simple section node")
+
+        /* Mark section as freed, for free space manager */
+        *sect = NULL;
+    } /* end else */
 
 done:
-    FUNC_LEAVE_NOAPI((H5FS_section_info_t *)ret_value)
-} /* end H5MF_sect_simple_split() */
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5MF_sect_large_shrink() */
 
diff --git a/src/H5Oalloc.c b/src/H5Oalloc.c
index 4f98cfa..40c9c38 100644
--- a/src/H5Oalloc.c
+++ b/src/H5Oalloc.c
@@ -2023,6 +2023,7 @@ H5O_merge_null(H5F_t *f, hid_t dxpl_id, H5O_t *oh)
                         /* Second message has been merged, delete it */
                         if(merged_msg) {
                             H5O_chunk_proxy_t *curr_chk_proxy;        /* Chunk that message is in */
+                            htri_t result;
 
                             /* Release any information/memory for second message */
                             H5O_msg_free_mesg(curr_msg2);
@@ -2050,6 +2051,13 @@ H5O_merge_null(H5F_t *f, hid_t dxpl_id, H5O_t *oh)
                             /* (Don't bother reducing size of message array for now -QAK) */
                             oh->nmesgs--;
 
+                            /* The merge null message might span the entire chunk: scan for empty chunk to remove */
+                            if((result = H5O_remove_empty_chunks(f, dxpl_id, oh)) < 0)
+                                HGOTO_ERROR(H5E_OHDR, H5E_CANTPACK, FAIL, "can't remove empty chunk")
+                            else if(result > 0)
+                                /* Get out of loop */
+                                break;
+
                             /* If the merged message is too large, shrink the chunk */
                             if(curr_msg->raw_size >= H5O_MESG_MAX_SIZE)
                                 if(H5O_alloc_shrink_chunk(f, dxpl_id, oh, curr_msg->chunkno) < 0)
diff --git a/src/H5Ocache_image.c b/src/H5Ocache_image.c
index 65f6aa2..bea99a2 100644
--- a/src/H5Ocache_image.c
+++ b/src/H5Ocache_image.c
@@ -33,6 +33,7 @@
 
 #include "H5private.h"          /* Generic Functions                     */
 #include "H5Eprivate.h"         /* Error handling                        */
+#include "H5Fprivate.h"		/* Files				*/
 #include "H5FLprivate.h"        /* Free Lists                            */
 #include "H5Opkg.h"             /* Object headers                        */
 #include "H5MFprivate.h"        /* File space management                 */
@@ -290,9 +291,50 @@ H5O__mdci_delete(H5F_t *f, hid_t dxpl_id, H5O_t *open_oh, void *_mesg)
     HDassert(mesg);
 
     /* Free file space for cache image */
-    if(H5F_addr_defined(mesg->addr))
-        if(H5MF_xfree(f, H5FD_MEM_SUPER, dxpl_id, mesg->addr, mesg->size) < 0)
-            HGOTO_ERROR(H5E_OHDR, H5E_CANTFREE, FAIL, "unable to free file space for cache image block")
+    if(H5F_addr_defined(mesg->addr)) {
+        /* The space for the cache image block was allocated directly
+         * from the VFD layer at the end of file.  As this was the
+         * last file space allocation before shutdown, the cache image
+         * should still be the last item in the file.
+         *
+         * If the hack to work around the self referential free space
+         * manager issue is in use, file space for the non-empty self
+         * referential free space managers was also allocated from VFD
+         * layer at the end of file.  Since these allocations directly
+         * preceeded the cache image allocation they should be directly
+         * adjacent to the cache image block at the end of file.
+         *
+         * In this case, just call H5MF_tidy_self_referential_fsm_hack().
+         *
+         * That routine will float the self referential free space
+         * managers, and reduce the eoa to its value just prior to
+         * allocation of space for same.  Since the cache image appears
+         * just after the self referential free space managers, this
+         * will release the file space for the cache image as well.
+         *
+         * Note that in this case, there must not have been any file
+         * space allocations / deallocations prior to the free of the
+         * cache image.  Verify this to the extent possible.
+         *
+         * If the hack to work around the persistant self referential
+         * free space manager issue is NOT in use, just call H5MF_xfree()
+         * to release the cache iamge.  In principle, we should be able
+         * to just reduce the EOA to the base address of the cache
+         * image block, as there shouldn't be any file space allocation
+         * before the first metadata cache access.  However, given
+         * time constraints, I don't want to go there now.
+         */
+        if(H5F_FIRST_ALLOC_DEALLOC(f)) {
+            HDassert(HADDR_UNDEF !=H5F_EOA_PRE_FSM_FSALLOC(f));
+            HDassert(H5F_addr_ge(mesg->addr, H5F_EOA_PRE_FSM_FSALLOC(f)));
+            if(H5MF_tidy_self_referential_fsm_hack(f, dxpl_id) < 0)
+                HGOTO_ERROR(H5E_OHDR, H5E_CANTFREE, FAIL, "tidy of self referential fsm hack failed")
+        } /* end if */
+        else {
+            if(H5MF_xfree(f, H5FD_MEM_SUPER, dxpl_id, mesg->addr, mesg->size) < 0)
+                HGOTO_ERROR(H5E_OHDR, H5E_CANTFREE, FAIL, "unable to free file space for cache image block")
+        } /* end else */
+    } /* end if */
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
diff --git a/src/H5Ofsinfo.c b/src/H5Ofsinfo.c
index 938d319..37ec627 100644
--- a/src/H5Ofsinfo.c
+++ b/src/H5Ofsinfo.c
@@ -23,12 +23,13 @@
  *
  *-------------------------------------------------------------------------
  */
-
+#define H5F_FRIEND              /*suppress error about including H5Fpkg   */
 #include "H5Omodule.h"          /* This source code file is part of the H5O module */
 
 
 #include "H5private.h"		/* Generic Functions	*/
 #include "H5Eprivate.h"		/* Error handling	*/
+#include "H5Fpkg.h"             /* File access          */
 #include "H5FLprivate.h"	/* Free lists          	*/
 #include "H5Opkg.h"             /* Object headers	*/
 
@@ -66,7 +67,8 @@ const H5O_msg_class_t H5O_MSG_FSINFO[1] = {{
 }};
 
 /* Current version of free-space manager info information */
-#define H5O_FSINFO_VERSION 	0
+#define H5O_FSINFO_VERSION_0 	0
+#define H5O_FSINFO_VERSION_1 	1
 
 /* Declare a free list to manage the H5O_fsinfo_t struct */
 H5FL_DEFINE_STATIC(H5O_fsinfo_t);
@@ -85,12 +87,13 @@ H5FL_DEFINE_STATIC(H5O_fsinfo_t);
  *-------------------------------------------------------------------------
  */
 static void *
-H5O_fsinfo_decode(H5F_t *f, hid_t H5_ATTR_UNUSED dxpl_id, H5O_t H5_ATTR_UNUSED *open_oh,
+H5O_fsinfo_decode(H5F_t *f, hid_t dxpl_id, H5O_t H5_ATTR_UNUSED *open_oh,
     unsigned H5_ATTR_UNUSED mesg_flags, unsigned H5_ATTR_UNUSED *ioflags, const uint8_t *p)
 {
-    H5O_fsinfo_t	*fsinfo = NULL; /* free-space manager info */
-    H5FD_mem_t 		type;		/* Memory type for iteration */
-    void                *ret_value = NULL;      /* Return value */
+    H5O_fsinfo_t    *fsinfo = NULL;     /* File space info message */
+    H5F_mem_page_t  ptype;              /* Memory type for iteration */
+    unsigned        vers;               /* message version */
+    void            *ret_value = NULL;  /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
 
@@ -98,26 +101,83 @@ H5O_fsinfo_decode(H5F_t *f, hid_t H5_ATTR_UNUSED dxpl_id, H5O_t H5_ATTR_UNUSED *
     HDassert(f);
     HDassert(p);
 
-    /* Version of message */
-    if(*p++ != H5O_FSINFO_VERSION)
-        HGOTO_ERROR(H5E_OHDR, H5E_CANTLOAD, NULL, "bad version number for message")
-
     /* Allocate space for message */
     if(NULL == (fsinfo = H5FL_CALLOC(H5O_fsinfo_t)))
 	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")
 
-    fsinfo->strategy = (H5F_file_space_type_t)*p++;	/* file space strategy */
-    H5F_DECODE_LENGTH(f, p, fsinfo->threshold);	/* free space section size threshold */
+    for(ptype = H5F_MEM_PAGE_SUPER; ptype < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, ptype))
+        fsinfo->fs_addr[ptype - 1] = HADDR_UNDEF;
 
-    /* Addresses of free space managers: only exist for H5F_FILE_SPACE_ALL_PERSIST */
-    if(fsinfo->strategy == H5F_FILE_SPACE_ALL_PERSIST) {
-	for(type = H5FD_MEM_SUPER; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type))
-	    H5F_addr_decode(f, &p, &(fsinfo->fs_addr[type-1]));
-    } /* end if */
-    else {
-	for(type = H5FD_MEM_SUPER; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type))
-	    fsinfo->fs_addr[type-1] = HADDR_UNDEF;
-    } /* end else */
+    /* Version of message */
+    vers = *p++;
+
+    if(vers == H5O_FSINFO_VERSION_0) {
+        H5F_file_space_type_t strategy;     /* Strategy */
+        hsize_t threshold;                  /* Threshold */
+        H5FD_mem_t type;                    /* Memory type for iteration */
+
+        fsinfo->persist = H5F_FREE_SPACE_PERSIST_DEF;
+        fsinfo->threshold = H5F_FREE_SPACE_THRESHOLD_DEF;
+        fsinfo->page_size = H5F_FILE_SPACE_PAGE_SIZE_DEF;
+        fsinfo->pgend_meta_thres = H5F_FILE_SPACE_PGEND_META_THRES;
+        fsinfo->eoa_pre_fsm_fsalloc = HADDR_UNDEF;
+
+        strategy = (H5F_file_space_type_t)*p++; /* File space strategy */
+        H5F_DECODE_LENGTH(f, p, threshold);     /* Free-space section threshold */
+
+        /* Map version 0 (deprecated) to version 1 message */
+        switch(strategy) {
+
+            case H5F_FILE_SPACE_ALL_PERSIST:
+                fsinfo->strategy = H5F_FSPACE_STRATEGY_FSM_AGGR;
+                fsinfo->persist = TRUE;
+                fsinfo->threshold = threshold;
+                if(HADDR_UNDEF == (fsinfo->eoa_pre_fsm_fsalloc = H5F_get_eoa(f, H5FD_MEM_DEFAULT)) )
+                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, NULL, "unable to get file size")
+                for(type = H5FD_MEM_SUPER; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type))
+                    H5F_addr_decode(f, &p, &(fsinfo->fs_addr[type-1]));
+                break;
+
+            case H5F_FILE_SPACE_ALL:
+                fsinfo->strategy = H5F_FSPACE_STRATEGY_FSM_AGGR;
+                fsinfo->threshold = threshold;
+                break;
+
+            case H5F_FILE_SPACE_AGGR_VFD:
+                fsinfo->strategy = H5F_FSPACE_STRATEGY_AGGR;
+                break;
+
+            case H5F_FILE_SPACE_VFD:
+                fsinfo->strategy = H5F_FSPACE_STRATEGY_NONE;
+                break;
+
+            case H5F_FILE_SPACE_NTYPES:
+            case H5F_FILE_SPACE_DEFAULT:
+            default:
+                HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, NULL, "invalid file space strategy")
+        } /* end switch */
+
+        fsinfo->mapped = TRUE;
+       
+    } else {
+        HDassert(vers == H5O_FSINFO_VERSION_1);
+
+        fsinfo->strategy = (H5F_fspace_strategy_t)*p++; /* File space strategy */
+        fsinfo->persist = *p++;                         /* Free-space persist or not */
+        H5F_DECODE_LENGTH(f, p, fsinfo->threshold);     /* Free-space section threshold */
+
+        H5F_DECODE_LENGTH(f, p, fsinfo->page_size); /* File space page size */
+        UINT16DECODE(p, fsinfo->pgend_meta_thres);  /* Page end metdata threshold */
+        H5F_addr_decode(f, &p, &(fsinfo->eoa_pre_fsm_fsalloc)); /* EOA before free-space header and section info */
+
+        /* Decode addresses of free space managers, if persisting */
+        if(fsinfo->persist) {
+            for(ptype = H5F_MEM_PAGE_SUPER; ptype < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, ptype))
+                H5F_addr_decode(f, &p, &(fsinfo->fs_addr[ptype - 1]));
+        } /* end if */
+
+        fsinfo->mapped = FALSE;
+    }
 
     /* Set return value */
     ret_value = fsinfo;
@@ -145,7 +205,7 @@ static herr_t
 H5O_fsinfo_encode(H5F_t *f, hbool_t H5_ATTR_UNUSED disable_shared, uint8_t *p, const void *_mesg)
 {
     const H5O_fsinfo_t  *fsinfo = (const H5O_fsinfo_t *)_mesg;
-    H5FD_mem_t 		type;	/* Memory type for iteration */
+    H5F_mem_page_t 	ptype;  /* Memory type for iteration */
 
     FUNC_ENTER_NOAPI_NOINIT_NOERR
 
@@ -154,14 +214,20 @@ H5O_fsinfo_encode(H5F_t *f, hbool_t H5_ATTR_UNUSED disable_shared, uint8_t *p, c
     HDassert(p);
     HDassert(fsinfo);
 
-    *p++ = H5O_FSINFO_VERSION;	/* message version */
-    *p++ = fsinfo->strategy;	/* file space strategy */
-    H5F_ENCODE_LENGTH(f, p, fsinfo->threshold); /* free-space section size threshold */
+    *p++ = H5O_FSINFO_VERSION_1;	/* message version */
+    *p++ = fsinfo->strategy;	    /* File space strategy */
+    *p++ = (unsigned char)fsinfo->persist;	/* Free-space persist or not */
+    H5F_ENCODE_LENGTH(f, p, fsinfo->threshold); /* Free-space section size threshold */
+
+    H5F_ENCODE_LENGTH(f, p, fsinfo->page_size);	/* File space page size */
+    UINT16ENCODE(p, fsinfo->pgend_meta_thres);	/* Page end metadata threshold */
+    H5F_addr_encode(f, &p, fsinfo->eoa_pre_fsm_fsalloc);    /* EOA before free-space header and section info */
 
-    /* Addresses of free space managers: only exist for H5F_FILE_SPACE_ALL_PERSIST */
-    if(fsinfo->strategy == H5F_FILE_SPACE_ALL_PERSIST) {
-	for(type = H5FD_MEM_SUPER; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type))
-	    H5F_addr_encode(f, &p, fsinfo->fs_addr[type-1]);
+    /* Store addresses of free-space managers, if persisting */
+    if(fsinfo->persist) {
+        /* Addresses of free-space managers */
+        for(ptype = H5F_MEM_PAGE_SUPER; ptype < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, ptype))
+            H5F_addr_encode(f, &p, fsinfo->fs_addr[ptype - 1]);
     } /* end if */
 
     FUNC_LEAVE_NOAPI(SUCCEED)
@@ -224,19 +290,19 @@ static size_t
 H5O_fsinfo_size(const H5F_t *f, hbool_t H5_ATTR_UNUSED disable_shared, const void *_mesg)
 {
     const H5O_fsinfo_t   *fsinfo = (const H5O_fsinfo_t *)_mesg;
-    size_t fs_addr_size = 0;
     size_t ret_value = 0;       /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT_NOERR
 
-
-    /* Addresses of free-space managers exist only for H5F_FILE_SPACE_ALL_PERSIST type */
-    if(H5F_FILE_SPACE_ALL_PERSIST == fsinfo->strategy)
-	fs_addr_size = (H5FD_MEM_NTYPES - 1) * (size_t)H5F_SIZEOF_ADDR(f);
-
-    ret_value = 2                       /* Version & strategy */
-		+ (size_t)H5F_SIZEOF_SIZE(f)	/* Threshold */
-                + fs_addr_size;		/* Addresses of free-space managers */
+    ret_value = 3                       /* Version, strategy & persist */
+		+ (size_t)H5F_SIZEOF_SIZE(f)    /* Free-space section threshold */
+		+ (size_t)H5F_SIZEOF_SIZE(f)    /* File space page size */
+		+ 2                             /* Page end meta threshold */
+		+ (size_t)H5F_SIZEOF_ADDR(f);
+    
+    /* Free-space manager addresses */
+    if(fsinfo->persist)
+        ret_value += (H5F_MEM_PAGE_NTYPES - 1) * (size_t)H5F_SIZEOF_ADDR(f);
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5O_fsinfo_size() */
@@ -282,7 +348,7 @@ H5O_fsinfo_debug(H5F_t H5_ATTR_UNUSED *f, hid_t H5_ATTR_UNUSED dxpl_id, const vo
 	       int indent, int fwidth)
 {
     const H5O_fsinfo_t	*fsinfo = (const H5O_fsinfo_t *) _mesg;
-    H5FD_mem_t 		type;	/* Memory type for iteration */
+    H5F_mem_page_t  ptype;      /* Free-space types for iteration */
 
     FUNC_ENTER_NOAPI_NOINIT_NOERR
 
@@ -293,16 +359,48 @@ H5O_fsinfo_debug(H5F_t H5_ATTR_UNUSED *f, hid_t H5_ATTR_UNUSED dxpl_id, const vo
     HDassert(indent >= 0);
     HDassert(fwidth >= 0);
 
-    HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
-              "File space strategy:", fsinfo->strategy);
+    HDfprintf(stream, "%*s%-*s ", indent, "", fwidth, "File space strategy:");
+    switch(fsinfo->strategy) {
+        case H5F_FSPACE_STRATEGY_FSM_AGGR:
+            HDfprintf(stream, "%s\n", "H5F_FSPACE_STRATEGY_FSM_AGGR");
+            break;
+
+        case H5F_FSPACE_STRATEGY_PAGE:
+            HDfprintf(stream, "%s\n", "H5F_FSPACE_STRATEGY_PAGE");
+            break;
+
+        case H5F_FSPACE_STRATEGY_AGGR:
+            HDfprintf(stream, "%s\n", "H5F_FSPACE_STRATEGY_AGGR");
+            break;
+
+        case H5F_FSPACE_STRATEGY_NONE:
+            HDfprintf(stream, "%s\n", "H5F_FSPACE_STRATEGY_NONE");
+            break;
+
+        case H5F_FSPACE_STRATEGY_NTYPES:
+        default:
+            HDfprintf(stream, "%s\n", "unknown");
+    } /* end switch */
+
+    HDfprintf(stream, "%*s%-*s %t\n", indent, "", fwidth,
+              "Free-space persist:", fsinfo->persist);
 
     HDfprintf(stream, "%*s%-*s %Hu\n", indent, "", fwidth,
-              "Free space section threshold:", fsinfo->threshold);
+              "Free-space section threshold:", fsinfo->threshold);
+
+    HDfprintf(stream, "%*s%-*s %Hu\n", indent, "", fwidth,
+              "File space page size:", fsinfo->page_size);
+
+    HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
+              "Page end metadata threshold:", fsinfo->pgend_meta_thres);
+
+    HDfprintf(stream, "%*s%-*s %a\n", indent, "", fwidth,
+              "eoa_pre_fsm_fsalloc:", fsinfo->eoa_pre_fsm_fsalloc);
 
-    if(fsinfo->strategy == H5F_FILE_SPACE_ALL_PERSIST) {
-	for(type = H5FD_MEM_SUPER; type < H5FD_MEM_NTYPES; H5_INC_ENUM(H5FD_mem_t, type))
-	    HDfprintf(stream, "%*s%-*s %a\n", indent, "", fwidth,
-		"Free space manager address:", fsinfo->fs_addr[type-1]);
+    if(fsinfo->persist) {
+        for(ptype = H5F_MEM_PAGE_SUPER; ptype < H5F_MEM_PAGE_NTYPES; H5_INC_ENUM(H5F_mem_page_t, ptype))
+            HDfprintf(stream, "%*s%-*s %a\n", indent, "", fwidth,
+                "Free space manager address:", fsinfo->fs_addr[ptype-1]);
     } /* end if */
 
     FUNC_LEAVE_NOAPI(SUCCEED)
diff --git a/src/H5Omessage.c b/src/H5Omessage.c
index 376c888..7e6463a 100644
--- a/src/H5Omessage.c
+++ b/src/H5Omessage.c
@@ -2253,3 +2253,55 @@ done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5O_flush_msgs() */
 
+
+/*-------------------------------------------------------------------------
+ * Function:	H5O_msg_get_flags
+ *
+ * Purpose:	Queries a message's message flags in the object header
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Vailin; Jan 2013
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5O_msg_get_flags(const H5O_loc_t *loc, unsigned type_id, hid_t dxpl_id, uint8_t *flags)
+{
+    H5O_t *oh = NULL;                   /* Object header to use */
+    const H5O_msg_class_t *type;        /* Actual H5O class type for the ID */
+    H5O_mesg_t *idx_msg;                /* Pointer to message to modify */
+    unsigned idx;                       /* Index of message to modify */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* check args */
+    HDassert(loc);
+    HDassert(loc->file);
+    HDassert(H5F_addr_defined(loc->addr));
+    HDassert(type_id < NELMTS(H5O_msg_class_g));
+    type = H5O_msg_class_g[type_id];    /* map the type ID to the actual type object */
+    HDassert(type);
+
+    /* Get the object header */
+    if(NULL == (oh = H5O_protect(loc, dxpl_id, H5AC__READ_ONLY_FLAG, FALSE)))
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTPROTECT, FAIL, "unable to protect object header")
+
+    /* Locate message of correct type */
+    for(idx = 0, idx_msg = &oh->mesg[0]; idx < oh->nmesgs; idx++, idx_msg++)
+        if(type == idx_msg->type)
+            break;
+
+    if(idx == oh->nmesgs)
+        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "message type not found")
+
+    /* Set return value */
+    *flags = idx_msg->flags;
+
+done:
+    if(oh && H5O_unprotect(loc, dxpl_id, oh, H5AC__NO_FLAGS_SET) < 0)
+        HDONE_ERROR(H5E_OHDR, H5E_CANTUNPROTECT, FAIL, "unable to release object header")
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5O_msg_get_flags() */
diff --git a/src/H5Oprivate.h b/src/H5Oprivate.h
index 71c512c..f0fbe72 100644
--- a/src/H5Oprivate.h
+++ b/src/H5Oprivate.h
@@ -791,9 +791,16 @@ typedef unsigned H5O_unknown_t;         /* Original message type ID */
  * (Data structure in memory)
  */
 typedef struct H5O_fsinfo_t {
-    H5F_file_space_type_t strategy;	/* File space strategy */
-    hsize_t		  threshold;	/* Free space section threshold */
-    haddr_t     	  fs_addr[H5FD_MEM_NTYPES-1]; /* Addresses of free space managers */
+    H5F_fspace_strategy_t   strategy;       /* File space strategy */
+    hbool_t persist;                        /* Persisting free-space or not */
+    hsize_t threshold;                      /* Free-space section threshold */
+    hsize_t page_size;                      /* For paged aggregation: file space page size */
+    size_t pgend_meta_thres;                /* For paged aggregation: page end metadata threshold */
+    haddr_t eoa_pre_fsm_fsalloc;            /* For paged aggregation: the eoa before free-space headers & sinfo */
+    haddr_t fs_addr[H5F_MEM_PAGE_NTYPES - 1];   /* 13 addresses of free-space managers */
+                                                /* For non-paged aggregation: only 6 addresses are used */
+    hbool_t mapped;                             /* Not stored */
+                                                /* Indicate the message is mapped from version 0 to version 1 */
 } H5O_fsinfo_t;
 
 /*
@@ -920,6 +927,7 @@ H5_DLL void* H5O_msg_decode(H5F_t *f, hid_t dxpl_id, H5O_t *open_oh,
     unsigned type_id, const unsigned char *buf);
 H5_DLL herr_t H5O_msg_delete(H5F_t *f, hid_t dxpl_id, H5O_t *open_oh,
     unsigned type_id, void *mesg);
+H5_DLL herr_t H5O_msg_get_flags(const H5O_loc_t *loc, unsigned type_id, hid_t dxpl_id, uint8_t *flags);
 
 /* Object metadata flush/refresh routines */
 H5_DLL herr_t H5O_flush_common(H5O_loc_t *oloc, hid_t obj_id, hid_t dxpl_id);
diff --git a/src/H5PB.c b/src/H5PB.c
new file mode 100644
index 0000000..c67ae59
--- /dev/null
+++ b/src/H5PB.c
@@ -0,0 +1,1533 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * Copyright by the Board of Trustees of the University of Illinois.         *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the files COPYING and Copyright.html.  COPYING can be found at the root   *
+ * of the source code distribution tree; Copyright.html can be found at the  *
+ * root level of an installed copy of the electronic HDF5 document set and   *
+ * is linked from the top-level documents page.  It can also be found at     *
+ * http://hdfgroup.org/HDF5/doc/Copyright.html.  If you do not have          *
+ * access to either file, you may request a copy from help@hdfgroup.org.     *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*-------------------------------------------------------------------------
+ *
+ * Created:             H5PB.c
+ *
+ * Purpose:             Page Buffer routines.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+/****************/
+/* Module Setup */
+/****************/
+
+#define H5F_FRIEND		/*suppress error about including H5Fpkg	  */
+#include "H5PBmodule.h"         /* This source code file is part of the H5PB module */
+
+
+/***********/
+/* Headers */
+/***********/
+#include "H5private.h"		/* Generic Functions			*/
+#include "H5Eprivate.h"		/* Error handling		  	*/
+#include "H5Fpkg.h"		/* Files				*/
+#include "H5FDprivate.h"	/* File drivers				*/
+#include "H5Iprivate.h"		/* IDs			  		*/
+#include "H5PBpkg.h"            /* File access				*/
+#include "H5SLprivate.h"	/* Skip List				*/
+
+
+/****************/
+/* Local Macros */
+/****************/
+#define H5PB__PREPEND(page_ptr, head_ptr, tail_ptr, len) {              \
+        if((head_ptr) == NULL) {                                        \
+            (head_ptr) = (page_ptr);                                    \
+            (tail_ptr) = (page_ptr);                                    \
+        } /* end if */                                                  \
+        else {                                                          \
+            (head_ptr)->prev = (page_ptr);                              \
+            (page_ptr)->next = (head_ptr);                              \
+            (head_ptr) = (page_ptr);                                    \
+        } /* end else */                                                \
+        (len)++;                                                        \
+} /* H5PB__PREPEND() */
+
+#define H5PB__REMOVE(page_ptr, head_ptr, tail_ptr, len) {               \
+        if((head_ptr) == (page_ptr)) {                                  \
+            (head_ptr) = (page_ptr)->next;                              \
+            if((head_ptr) != NULL)                                      \
+                (head_ptr)->prev = NULL;                                \
+        } /* end if */                                                  \
+        else                                                            \
+            (page_ptr)->prev->next = (page_ptr)->next;                  \
+        if((tail_ptr) == (page_ptr)) {                                  \
+            (tail_ptr) = (page_ptr)->prev;                              \
+            if((tail_ptr) != NULL)                                      \
+                (tail_ptr)->next = NULL;                                \
+        } /* end if */                                                  \
+        else                                                            \
+            (page_ptr)->next->prev = (page_ptr)->prev;                  \
+        page_ptr->next = NULL;                                          \
+        page_ptr->prev = NULL;                                          \
+        (len)--;                                                        \
+}
+
+#define H5PB__INSERT_LRU(page_buf, page_ptr) {                          \
+        HDassert(page_buf);                                             \
+        HDassert(page_ptr);                                             \
+        /* insert the entry at the head of the list. */                 \
+        H5PB__PREPEND((page_ptr), (page_buf)->LRU_head_ptr,             \
+                      (page_buf)->LRU_tail_ptr, (page_buf)->LRU_list_len) \
+}
+
+#define H5PB__REMOVE_LRU(page_buf, page_ptr) {                          \
+        HDassert(page_buf);                                             \
+        HDassert(page_ptr);                                             \
+        /* remove the entry from the list. */                           \
+        H5PB__REMOVE((page_ptr), (page_buf)->LRU_head_ptr,              \
+                     (page_buf)->LRU_tail_ptr, (page_buf)->LRU_list_len) \
+}
+
+#define H5PB__MOVE_TO_TOP_LRU(page_buf, page_ptr) {                     \
+        HDassert(page_buf);                                             \
+        HDassert(page_ptr);                                             \
+        /* Remove entry and insert at the head of the list. */          \
+        H5PB__REMOVE((page_ptr), (page_buf)->LRU_head_ptr,              \
+                     (page_buf)->LRU_tail_ptr, (page_buf)->LRU_list_len) \
+        H5PB__PREPEND((page_ptr), (page_buf)->LRU_head_ptr,             \
+                       (page_buf)->LRU_tail_ptr, (page_buf)->LRU_list_len) \
+}
+
+
+/******************/
+/* Local Typedefs */
+/******************/
+
+/* Iteration context for destroying page buffer */
+typedef struct {
+    H5PB_t *page_buf;
+    hbool_t actual_slist;
+} H5PB_ud1_t;
+
+
+/********************/
+/* Package Typedefs */
+/********************/
+
+
+/********************/
+/* Local Prototypes */
+/********************/
+static herr_t H5PB__insert_entry(H5PB_t *page_buf, H5PB_entry_t *page_entry);
+static htri_t H5PB__make_space(const H5F_io_info2_t *fio_info, H5PB_t *page_buf, H5FD_mem_t inserted_type);
+static herr_t H5PB__write_entry(const H5F_io_info2_t *fio_info, H5PB_entry_t *page_entry);
+
+
+/*********************/
+/* Package Variables */
+/*********************/
+
+/* Package initialization variable */
+hbool_t H5_PKG_INIT_VAR = FALSE;
+
+
+/*****************************/
+/* Library Private Variables */
+/*****************************/
+
+
+/*******************/
+/* Local Variables */
+/*******************/
+/* Declare a free list to manage the H5PB_t struct */
+H5FL_DEFINE_STATIC(H5PB_t);
+
+/* Declare a free list to manage the H5PB_entry_t struct */
+H5FL_DEFINE_STATIC(H5PB_entry_t);
+
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5PB_reset_stats
+ *
+ * Purpose:     This function was created without documentation.
+ *              What follows is my best understanding of Mohamad's intent.
+ *
+ *              Reset statistics collected for the page buffer layer.
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:	Mohamad Chaarawi
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t 
+H5PB_reset_stats(H5PB_t *page_buf)
+{
+    FUNC_ENTER_NOAPI_NOERR
+
+    /* Sanity checks */
+    HDassert(page_buf);
+
+    page_buf->accesses[0] = 0;
+    page_buf->accesses[1] = 0;
+    page_buf->hits[0] = 0;
+    page_buf->hits[1] = 0;
+    page_buf->misses[0] = 0;
+    page_buf->misses[1] = 0;
+    page_buf->evictions[0] = 0;
+    page_buf->evictions[1] = 0;
+    page_buf->bypasses[0] = 0;
+    page_buf->bypasses[1] = 0;
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+}  /* H5PB_reset_stats() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5PB_get_stats
+ *
+ * Purpose:     This function was created without documentation.
+ *              What follows is my best understanding of Mohamad's intent.
+ *
+ *              Retrieve statistics collected about page accesses for the page buffer layer.
+ *              --accesses: the number of metadata and raw data accesses to the page buffer layer
+ *              --hits: the number of metadata and raw data hits in the page buffer layer
+ *              --misses: the number of metadata and raw data misses in the page buffer layer
+ *              --evictions: the number of metadata and raw data evictions from the page buffer layer
+ *              --bypasses: the number of metadata and raw data accesses that bypass the page buffer layer
+ *
+ * Return:	    Non-negative on success/Negative on failure
+ *
+ * Programmer:	Mohamad Chaarawi
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t 
+H5PB_get_stats(const H5PB_t *page_buf, unsigned accesses[2], unsigned hits[2],
+    unsigned misses[2], unsigned evictions[2], unsigned bypasses[2])
+{
+    FUNC_ENTER_NOAPI_NOERR
+
+    /* Sanity checks */
+    HDassert(page_buf);
+
+    accesses[0] = page_buf->accesses[0];
+    accesses[1] = page_buf->accesses[1];
+    hits[0] = page_buf->hits[0];
+    hits[1] = page_buf->hits[1];
+    misses[0] = page_buf->misses[0];
+    misses[1] = page_buf->misses[1];
+    evictions[0] = page_buf->evictions[0];
+    evictions[1] = page_buf->evictions[1];
+    bypasses[0] = page_buf->bypasses[0];
+    bypasses[1] = page_buf->bypasses[1];
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+}  /* H5PB_get_stats */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5PB_print_stats()
+ *
+ * Purpose:     This function was created without documentation.
+ *              What follows is my best understanding of Mohamad's intent.
+ *
+ *              Print out statistics collected for the page buffer layer.
+ *
+ * Return:	    Non-negative on success/Negative on failure
+ *
+ * Programmer:	Mohamad Chaarawi
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5PB_print_stats(const H5PB_t *page_buf)
+{
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    HDassert(page_buf);
+
+    printf("PAGE BUFFER STATISTICS:\n");
+
+    printf("******* METADATA\n");
+    printf("\t Total Accesses: %u\n", page_buf->accesses[0]);
+    printf("\t Hits: %u\n", page_buf->hits[0]);
+    printf("\t Misses: %u\n", page_buf->misses[0]);
+    printf("\t Evictions: %u\n", page_buf->evictions[0]);
+    printf("\t Bypasses: %u\n", page_buf->bypasses[0]);
+    printf("\t Hit Rate = %f%%\n", ((double)page_buf->hits[0]/(page_buf->accesses[0] - page_buf->bypasses[0]))*100);
+    printf("*****************\n\n");
+
+    printf("******* RAWDATA\n");
+    printf("\t Total Accesses: %u\n", page_buf->accesses[1]);
+    printf("\t Hits: %u\n", page_buf->hits[1]);
+    printf("\t Misses: %u\n", page_buf->misses[1]);
+    printf("\t Evictions: %u\n", page_buf->evictions[1]);
+    printf("\t Bypasses: %u\n", page_buf->bypasses[1]);
+    printf("\t Hit Rate = %f%%\n", ((double)page_buf->hits[1]/(page_buf->accesses[1]-page_buf->bypasses[0]))*100);
+    printf("*****************\n\n");
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* H5PB_print_stats */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5PB_create
+ *
+ * Purpose:	Create and setup the PB on the file.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Mohamad Chaarawi
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5PB_create(H5F_t *f, size_t size, unsigned page_buf_min_meta_perc, unsigned page_buf_min_raw_perc)
+{
+    H5PB_t *page_buf = NULL;
+    herr_t ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(f);
+    HDassert(f->shared);
+
+    /* Check args */
+    if(f->shared->fs_strategy != H5F_FSPACE_STRATEGY_PAGE)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "Enabling Page Buffering requires PAGE file space strategy")
+    /* round down the size if it is larger than the page size */
+    else if(size > f->shared->fs_page_size) {
+        hsize_t temp_size;
+
+        temp_size = (size / f->shared->fs_page_size) * f->shared->fs_page_size;
+        H5_CHECKED_ASSIGN(size, size_t, temp_size, hsize_t);
+    } /* end if */
+    else if(0 != size % f->shared->fs_page_size)
+        HGOTO_ERROR(H5E_PAGEBUF, H5E_CANTINIT, FAIL, "Page Buffer size must be >= to the page size")
+
+    /* Allocate the new page buffering structure */
+    if(NULL == (page_buf = H5FL_CALLOC(H5PB_t)))
+	HGOTO_ERROR(H5E_PAGEBUF, H5E_NOSPACE, FAIL, "memory allocation failed")
+
+    page_buf->max_size = size;
+    H5_CHECKED_ASSIGN(page_buf->page_size, size_t, f->shared->fs_page_size, hsize_t);
+    page_buf->min_meta_perc = page_buf_min_meta_perc;
+    page_buf->min_raw_perc = page_buf_min_raw_perc;
+
+    /* Calculate the minimum page count for metadata and raw data
+     * based on the fractions provided 
+     */
+    page_buf->min_meta_count = (unsigned)((size * page_buf_min_meta_perc) / (f->shared->fs_page_size * 100));
+    page_buf->min_raw_count = (unsigned)((size * page_buf_min_raw_perc) / (f->shared->fs_page_size * 100));
+
+    if(NULL == (page_buf->slist_ptr = H5SL_create(H5SL_TYPE_HADDR, NULL)))
+        HGOTO_ERROR(H5E_PAGEBUF, H5E_CANTCREATE, FAIL, "can't create skip list")
+    if(NULL == (page_buf->mf_slist_ptr = H5SL_create(H5SL_TYPE_HADDR, NULL)))
+        HGOTO_ERROR(H5E_PAGEBUF, H5E_CANTCREATE, FAIL, "can't create skip list")
+
+    if(NULL == (page_buf->page_fac = H5FL_fac_init(page_buf->page_size)))
+        HGOTO_ERROR(H5E_PAGEBUF, H5E_CANTINIT, FAIL, "can't create page factory")
+
+    f->shared->page_buf = page_buf;
+
+done:
+    if(ret_value < 0) {
+        if(page_buf != NULL) {
+            if(page_buf->slist_ptr != NULL)
+                H5SL_close(page_buf->slist_ptr);
+            if(page_buf->mf_slist_ptr != NULL)
+                H5SL_close(page_buf->mf_slist_ptr);
+            if(page_buf->page_fac != NULL)
+                H5FL_fac_term(page_buf->page_fac);
+            page_buf = H5FL_FREE(H5PB_t, page_buf);
+        } /* end if */
+    } /* end if */
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5PB_create */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5PB__flush_cb
+ *
+ * Purpose:	Callback to flush PB skiplist entries.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Mohamad Chaarawi
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5PB__flush_cb(void *item, void H5_ATTR_UNUSED *key, void *_op_data)
+{
+    H5PB_entry_t *page_entry = (H5PB_entry_t *)item;    /* Pointer to page entry node */
+    const H5F_io_info2_t *fio_info = (const H5F_io_info2_t *)_op_data;
+    herr_t  ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity checks */
+    HDassert(page_entry);
+    HDassert(fio_info);
+
+    /* Flush the page if it's dirty */
+    if(page_entry->is_dirty)
+        if(H5PB__write_entry(fio_info, page_entry) < 0)
+            HGOTO_ERROR(H5E_PAGEBUF, H5E_WRITEERROR, FAIL, "file write failed")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5PB__flush_cb() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5PB_flush
+ *
+ * Purpose:	Flush/Free all the PB entries to the file.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Mohamad Chaarawi
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5PB_flush(const H5F_io_info2_t *fio_info)
+{
+    herr_t  ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity check */
+    HDassert(fio_info);
+    HDassert(fio_info->f);
+    HDassert(fio_info->meta_dxpl);
+    HDassert(fio_info->raw_dxpl);
+
+    /* Flush all the entries in the PB skiplist, if we have write access on the file */
+    if(fio_info->f->shared->page_buf && (H5F_ACC_RDWR & H5F_INTENT(fio_info->f))) {
+        H5PB_t *page_buf = fio_info->f->shared->page_buf;
+
+        /* Iterate over all entries in page buffer skip list */
+        if(H5SL_iterate(page_buf->slist_ptr, H5PB__flush_cb, (void *)fio_info))
+            HGOTO_ERROR(H5E_PAGEBUF, H5E_BADITER, FAIL, "can't flush page buffer skip list")
+    } /* end if */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5PB_flush */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5PB__dest_cb
+ *
+ * Purpose:	Callback to free PB skiplist entries.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Mohamad Chaarawi
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5PB__dest_cb(void *item, void H5_ATTR_UNUSED *key, void *_op_data)
+{
+    H5PB_entry_t *page_entry = (H5PB_entry_t *)item;       /* Pointer to page entry node */
+    H5PB_ud1_t *op_data = (H5PB_ud1_t *)_op_data;
+
+    FUNC_ENTER_STATIC_NOERR
+
+    /* Sanity checking */
+    HDassert(page_entry);
+    HDassert(op_data);
+    HDassert(op_data->page_buf);
+
+    /* Remove entry from LRU list */
+    if(op_data->actual_slist) {
+        H5PB__REMOVE_LRU(op_data->page_buf, page_entry)
+        page_entry->page_buf_ptr = H5FL_FAC_FREE(op_data->page_buf->page_fac, page_entry->page_buf_ptr);
+    } /* end if */
+
+    /* Free page entry */
+    page_entry = H5FL_FREE(H5PB_entry_t, page_entry);
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* H5PB__dest_cb() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5PB_dest
+ *
+ * Purpose:	destroy the PB on the file.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Mohamad Chaarawi
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5PB_dest(H5F_t *f)
+{
+    herr_t  ret_value = SUCCEED;        /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(f);
+
+    /* Destroy page buffer info, if there is any */
+    if(f->shared->page_buf) {
+        H5PB_t *page_buf = f->shared->page_buf;
+        H5PB_ud1_t op_data;                 /* Iteration context */
+
+        /* Set up context info */
+        op_data.page_buf = page_buf;
+
+        /* Destroy the skip list containing all the entries in the PB */
+        op_data.actual_slist = TRUE;
+        if(H5SL_destroy(page_buf->slist_ptr, H5PB__dest_cb, &op_data))
+            HGOTO_ERROR(H5E_PAGEBUF, H5E_CANTCLOSEOBJ, FAIL, "can't destroy page buffer skip list")
+
+        /* Destroy the skip list containing the new entries */
+        op_data.actual_slist = FALSE;
+        if(H5SL_destroy(page_buf->mf_slist_ptr, H5PB__dest_cb, &op_data))
+            HGOTO_ERROR(H5E_PAGEBUF, H5E_CANTCLOSEOBJ, FAIL, "can't destroy page buffer skip list")
+
+        /* Destroy the page factory */
+        if(H5FL_fac_term(page_buf->page_fac) < 0)
+            HGOTO_ERROR(H5E_PAGEBUF, H5E_CANTRELEASE, FAIL, "can't destroy page buffer page factory")
+
+#ifdef QAK
+H5PB_print_stats(page_buf);
+#endif /* QAK */
+
+        f->shared->page_buf = H5FL_FREE(H5PB_t, page_buf);
+    } /* end if */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5PB_dest */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5PB_add_new_page
+ *
+ * Purpose:	Add a new page to the new page skip list. This is called 
+ *              from the MF layer when a new page is allocated to 
+ *              indicate to the page buffer layer that a read of the page 
+ *              from the file is not necessary since it's an empty page.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Mohamad Chaarawi
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t 
+H5PB_add_new_page(H5F_t *f, H5FD_mem_t type, haddr_t page_addr)
+{
+    H5PB_t *page_buf = f->shared->page_buf;
+    H5PB_entry_t *page_entry = NULL;    /* pointer to the corresponding page entry */
+    herr_t ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(page_buf);
+
+    /* If there is an existing page, this means that at some point the
+     * file free space manager freed and re-allocated a page at the same
+     * address.  No need to do anything here then...
+     */
+    /* MSC - to be safe, might want to dig in the MF layer and remove
+     * the page when it is freed from this list if it still exists and
+     * remove this check
+     */
+    if(NULL == H5SL_search(page_buf->mf_slist_ptr, &(page_addr))) {
+        /* Create the new PB entry */
+        if(NULL == (page_entry = H5FL_CALLOC(H5PB_entry_t)))
+            HGOTO_ERROR(H5E_PAGEBUF, H5E_NOSPACE, FAIL, "memory allocation failed")
+
+        /* Initialize page fields */
+        page_entry->addr = page_addr;
+        page_entry->type = (H5F_mem_page_t)type;
+        page_entry->is_dirty = FALSE;
+
+        /* Insert entry in skip list */
+        if(H5SL_insert(page_buf->mf_slist_ptr, page_entry, &(page_entry->addr)) < 0)
+            HGOTO_ERROR(H5E_PAGEBUF, H5E_BADVALUE, FAIL, "Can't insert entry in skip list")
+    } /* end if */
+
+done:
+    if(ret_value < 0)
+        if(page_entry)
+            page_entry = H5FL_FREE(H5PB_entry_t, page_entry);
+
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5PB_add_new_page */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5PB_update_entry
+ *
+ * Purpose:	In PHDF5, entries that are written by other processes and just 
+ *              marked clean by this process have to have their corresponding 
+ *              pages updated if they exist in the page buffer. 
+ *              This routine checks and update the pages.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Mohamad Chaarawi
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t 
+H5PB_update_entry(H5PB_t *page_buf, haddr_t addr, size_t size, const void *buf)
+{
+    H5PB_entry_t *page_entry;   /* Pointer to the corresponding page entry */
+    haddr_t page_addr;
+
+    FUNC_ENTER_NOAPI_NOERR
+
+    /* Sanity checks */
+    HDassert(page_buf);
+    HDassert(size <= page_buf->page_size);
+    HDassert(buf);
+
+    /* calculate the aligned address of the first page */
+    page_addr = (addr / page_buf->page_size) * page_buf->page_size;
+
+    /* search for the page and update if found */
+    page_entry = (H5PB_entry_t *)H5SL_search(page_buf->slist_ptr, (void *)(&page_addr));
+    if(page_entry) {
+        haddr_t offset;
+
+        HDassert(addr + size <= page_addr + page_buf->page_size);
+        offset = addr - page_addr;
+        HDmemcpy((uint8_t *)page_entry->page_buf_ptr + offset, buf, size);
+
+        /* move to top of LRU list */
+        H5PB__MOVE_TO_TOP_LRU(page_buf, page_entry)
+    } /* end if */
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* H5PB_update_entry */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5PB_remove_entry
+ *
+ * Purpose:     Remove possible metadata entry with ADDR from the PB cache.
+ *              This is in response to the data corruption bug from fheap.c 
+ *              with page buffering + page strategy.
+ *              Note: Large metadata page bypasses the PB cache.
+ *              Note: Update of raw data page (large or small sized) is handled by the PB cache.
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Vailin Choi; Feb 2017
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5PB_remove_entry(const H5F_t *f, haddr_t addr)
+{
+    H5PB_t *page_buf = f->shared->page_buf;
+    H5PB_entry_t *page_entry = NULL;        /* pointer to the page entry being searched */
+    herr_t ret_value = SUCCEED;             /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(page_buf);
+
+    /* Search for address in the skip list */
+    page_entry = (H5PB_entry_t *)H5SL_search(page_buf->slist_ptr, (void *)(&addr));
+
+    /* If found, remove the entry from the PB cache */
+    if(page_entry) {
+        HDassert(page_entry->type != H5F_MEM_PAGE_DRAW);
+        if(NULL == H5SL_remove(page_buf->slist_ptr, &(page_entry->addr)))
+            HGOTO_ERROR(H5E_CACHE, H5E_BADVALUE, FAIL, "Page Entry is not in skip list")
+
+        /* Remove from LRU list */
+        H5PB__REMOVE_LRU(page_buf, page_entry)
+        HDassert(H5SL_count(page_buf->slist_ptr) == page_buf->LRU_list_len);
+
+        page_buf->meta_count--;
+
+        page_entry->page_buf_ptr = H5FL_FAC_FREE(page_buf->page_fac, page_entry->page_buf_ptr);
+        page_entry = H5FL_FREE(H5PB_entry_t, page_entry);
+    } /* end if */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5PB_remove_entry */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5PB_read
+ *
+ * Purpose:	Reads in the data from the page containing it if it exists 
+ *              in the PB cache; otherwise reads in the page through the VFD.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Mohamad Chaarawi
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5PB_read(const H5F_io_info2_t *fio_info, H5FD_mem_t type, haddr_t addr,
+    size_t size, void *buf/*out*/)
+{
+    H5PB_t *page_buf;                   /* Page buffering info for this file */
+    H5PB_entry_t *page_entry;           /* Pointer to the corresponding page entry */
+    H5FD_io_info_t fdio_info;           /* File driver I/O info */
+    haddr_t first_page_addr, last_page_addr;    /* Addresses of the first and last pages covered by I/O */
+    haddr_t offset;
+    haddr_t search_addr;                /* Address of current page */
+    hsize_t num_touched_pages;          /* Number of pages accessed */
+    size_t access_size;
+    hbool_t bypass_pb = FALSE;          /* Whether to bypass page buffering */
+    hsize_t i;                          /* Local index variable */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(fio_info);
+
+    /* Get pointer to page buffer info for this file */
+    page_buf = fio_info->f->shared->page_buf;
+
+#ifdef H5_HAVE_PARALLEL
+    if(H5F_HAS_FEATURE(fio_info->f, H5FD_FEAT_HAS_MPI)) {
+#if 1
+        bypass_pb = TRUE;
+#else
+        /* MSC - why this stopped working ? */
+        int mpi_size;
+
+        if((mpi_size = H5F_mpi_get_size(fio_info->f)) < 0)
+            HGOTO_ERROR(H5E_PAGEBUF, H5E_CANTGET, FAIL, "can't retrieve MPI communicator size")
+        if(1 != mpi_size)
+            bypass_pb = TRUE;
+#endif
+    } /* end if */
+#endif
+
+    /* If page buffering is disabled, or the I/O size is larger than that of a
+     * single page, or if this is a parallel raw data access, bypass page
+     * buffering.
+     */
+    if(NULL == page_buf || size >= page_buf->page_size ||
+           (bypass_pb && H5FD_MEM_DRAW == type)) {
+        if(H5F__accum_read(fio_info, type, addr, size, buf) < 0)
+            HGOTO_ERROR(H5E_PAGEBUF, H5E_READERROR, FAIL, "read through metadata accumulator failed")
+
+        /* Update statistics */
+        if(page_buf) {
+            if(type == H5FD_MEM_DRAW || type == H5FD_MEM_GHEAP)
+                page_buf->bypasses[1] ++;
+            else
+                page_buf->bypasses[0] ++;
+        } /* end if */
+
+        /* If page buffering is disabled, or if this is a large metadata access, 
+         * or if this is parallel raw data access, we are done here
+         */
+        if(NULL == page_buf || (size >= page_buf->page_size && H5FD_MEM_DRAW != type) ||
+                (bypass_pb && H5FD_MEM_DRAW == type))
+            HGOTO_DONE(SUCCEED)
+    } /* end if */
+
+    /* Update statistics */
+    if(page_buf) {
+        if(type == H5FD_MEM_DRAW || type == H5FD_MEM_GHEAP)
+            page_buf->accesses[1]++;
+        else
+            page_buf->accesses[0]++;
+    } /* end if */
+
+    /* Calculate the aligned address of the first page */
+    first_page_addr = (addr / page_buf->page_size) * page_buf->page_size;
+
+    /* For Raw data calculate the aligned address of the last page and
+     * the number of pages accessed if more than 1 page is accessed
+     */
+    if(H5FD_MEM_DRAW == type) {
+        last_page_addr = ((addr + size - 1) / page_buf->page_size) * page_buf->page_size;
+
+        /* How many pages does this write span */
+        num_touched_pages = (last_page_addr / page_buf->page_size + 1) - 
+                (first_page_addr / page_buf->page_size);
+        if(first_page_addr == last_page_addr) {
+            HDassert(1 == num_touched_pages);
+            last_page_addr = HADDR_UNDEF;
+        } /* end if */
+    } /* end if */
+    /* Otherwise set last page addr to HADDR_UNDEF */
+    else {
+        num_touched_pages = 1;
+        last_page_addr = HADDR_UNDEF;
+    } /* end else */
+
+    /* Translate to file driver I/O info object */
+    fdio_info.file = fio_info->f->shared->lf;
+    fdio_info.meta_dxpl = fio_info->meta_dxpl;
+    fdio_info.raw_dxpl = fio_info->raw_dxpl;
+
+    /* Copy raw data from dirty pages into the read buffer if the read
+       request spans pages in the page buffer*/
+    if(H5FD_MEM_DRAW == type && size >= page_buf->page_size) {
+        H5SL_node_t *node;
+
+        /* For each touched page in the page buffer, check if it
+         * exists in the page Buffer and is dirty. If it does, we
+         * update the buffer with what's in the page so we get the up
+         * to date data into the buffer after the big read from the file.
+         */
+        node = H5SL_find(page_buf->slist_ptr, (void *)(&first_page_addr));
+        for(i = 0; i < num_touched_pages; i++) {
+            search_addr = i*page_buf->page_size + first_page_addr;
+
+            /* if we still haven't located a starting page, search again */
+            if(!node && i!=0)
+                node = H5SL_find(page_buf->slist_ptr, (void *)(&search_addr));
+
+            /* if the current page is in the Page Buffer, do the updates */
+            if(node) {
+                page_entry = (H5PB_entry_t *)H5SL_item(node);
+
+                HDassert(page_entry);
+
+                /* If the current page address falls out of the access
+                   block, then there are no more pages to go over */
+                if(page_entry->addr >= addr + size)
+                    break;
+
+                HDassert(page_entry->addr == search_addr);
+
+                if(page_entry->is_dirty) {
+                    /* special handling for the first page if it is not a full page access */
+                    if(i == 0 && first_page_addr != addr) {
+                        offset = addr - first_page_addr;
+                        HDassert(page_buf->page_size > offset);
+
+                        HDmemcpy(buf, (uint8_t *)page_entry->page_buf_ptr + offset, 
+                                 page_buf->page_size - (size_t)offset);
+
+                        /* move to top of LRU list */
+                        H5PB__MOVE_TO_TOP_LRU(page_buf, page_entry)
+                    } /* end if */
+                    /* special handling for the last page if it is not a full page access */
+                    else if(num_touched_pages > 1 && i == num_touched_pages-1 && search_addr < addr+size) {
+                        offset = (num_touched_pages-2)*page_buf->page_size + 
+                            (page_buf->page_size - (addr - first_page_addr));
+
+                        HDmemcpy((uint8_t *)buf + offset, page_entry->page_buf_ptr,
+                                 (size_t)((addr + size) - last_page_addr));
+
+                        /* move to top of LRU list */
+                        H5PB__MOVE_TO_TOP_LRU(page_buf, page_entry)
+                    } /* end else-if */
+                    /* copy the entire fully accessed pages */
+                    else {
+                        offset = i*page_buf->page_size;
+
+                        HDmemcpy((uint8_t *)buf+(i*page_buf->page_size) , page_entry->page_buf_ptr, 
+                             page_buf->page_size);
+                    } /* end else */
+                } /* end if */
+                node = H5SL_next(node);
+            } /* end if */
+        } /* end for */
+    } /* end if */
+    else {
+        /* A raw data access could span 1 or 2 PB entries at this point so
+           we need to handle that */
+        HDassert(1 == num_touched_pages || 2 == num_touched_pages);
+        for(i = 0 ; i < num_touched_pages; i++) {
+            haddr_t buf_offset;
+
+            /* Calculate the aligned address of the page to search for it in the skip list */
+            search_addr = (0==i ? first_page_addr : last_page_addr);
+
+            /* Calculate the access size if the access spans more than 1 page */
+            if(1 == num_touched_pages)
+                access_size = size;
+            else
+                access_size = (0 == i ? (size_t)((first_page_addr + page_buf->page_size) - addr) : (size - access_size));
+
+            /* Lookup the page in the skip list */
+            page_entry = (H5PB_entry_t *)H5SL_search(page_buf->slist_ptr, (void *)(&search_addr));
+
+            /* if found */
+            if(page_entry) {
+                offset = (0 == i ? addr - page_entry->addr : 0);
+                buf_offset = (0 == i ? 0 : size - access_size);
+
+                /* copy the requested data from the page into the input buffer */
+                HDmemcpy((uint8_t *)buf + buf_offset, (uint8_t *)page_entry->page_buf_ptr + offset, access_size);
+
+                /* Update LRU */
+                H5PB__MOVE_TO_TOP_LRU(page_buf, page_entry)
+
+                /* Update statistics */
+                if(type == H5FD_MEM_DRAW || type == H5FD_MEM_GHEAP)
+                    page_buf->hits[1]++;
+                else
+                    page_buf->hits[0]++;
+            } /* end if */
+            /* if not found */ 
+            else {
+                void *new_page_buf = NULL;
+                size_t page_size = page_buf->page_size;
+                haddr_t eoa;
+
+                /* make space for new entry */
+                if((H5SL_count(page_buf->slist_ptr) * page_buf->page_size) >= page_buf->max_size) {
+                    htri_t can_make_space;
+
+                    /* check if we can make space in page buffer */
+                    if((can_make_space = H5PB__make_space(fio_info, page_buf, type)) < 0)
+                        HGOTO_ERROR(H5E_PAGEBUF, H5E_NOSPACE, FAIL, "make space in Page buffer Failed")
+
+                    /* if make_space returns 0, then we can't use the page
+                       buffer for this I/O and we need to bypass */
+                    if(0 == can_make_space) {
+                        /* make space can't return FALSE on second touched page since the first is of the same type */
+                        HDassert(0 == i);
+
+                        /* read entire block from VFD and return */
+                        if(H5FD_read(&fdio_info, type, addr, size, buf) < 0)
+                            HGOTO_ERROR(H5E_PAGEBUF, H5E_READERROR, FAIL, "driver read request failed")
+
+                        /* Break out of loop */
+                        break;
+                    } /* end if */
+                } /* end if */
+
+                /* Read page from VFD */
+                if(NULL == (new_page_buf = H5FL_FAC_MALLOC(page_buf->page_fac)))
+                    HGOTO_ERROR(H5E_PAGEBUF, H5E_CANTALLOC, FAIL, "memory allocation failed for page buffer entry")
+
+                /* Read page through the VFD layer, but make sure we don't read past the EOA. */
+
+                /* Retrieve the 'eoa' for the file */
+                if(HADDR_UNDEF == (eoa = H5F_get_eoa(fio_info->f, type)))
+                    HGOTO_ERROR(H5E_PAGEBUF, H5E_CANTGET, FAIL, "driver get_eoa request failed")
+
+                /* If the entire page falls outside the EOA, then fail */
+                if(search_addr > eoa)
+                    HGOTO_ERROR(H5E_PAGEBUF, H5E_BADVALUE, FAIL, "reading an entire page that is outside the file EOA")
+
+                /* Adjust the read size to not go beyond the EOA */
+                if(search_addr + page_size > eoa)
+                    page_size = (size_t)(eoa - search_addr);
+
+                /* Read page from VFD */
+                if(H5FD_read(&fdio_info, type, search_addr, page_size, new_page_buf) < 0)
+                    HGOTO_ERROR(H5E_PAGEBUF, H5E_READERROR, FAIL, "driver read request failed")
+
+                /* Copy the requested data from the page into the input buffer */
+                offset = (0 == i ? addr - search_addr : 0);
+                buf_offset = (0 == i ? 0 : size - access_size);
+                HDmemcpy((uint8_t *)buf + buf_offset, (uint8_t *)new_page_buf + offset, access_size);
+
+                /* Create the new PB entry */
+                if(NULL == (page_entry = H5FL_CALLOC(H5PB_entry_t)))
+                    HGOTO_ERROR(H5E_PAGEBUF, H5E_NOSPACE, FAIL, "memory allocation failed")
+
+                page_entry->page_buf_ptr = new_page_buf;
+                page_entry->addr = search_addr;
+                page_entry->type = (H5F_mem_page_t)type;
+                page_entry->is_dirty = FALSE;
+
+                /* Insert page into PB */
+                if(H5PB__insert_entry(page_buf, page_entry) < 0)
+                    HGOTO_ERROR(H5E_PAGEBUF, H5E_CANTSET, FAIL, "error inserting new page in page buffer")
+
+                /* Update statistics */
+                if(type == H5FD_MEM_DRAW || type == H5FD_MEM_GHEAP)
+                    page_buf->misses[1]++;
+                else
+                    page_buf->misses[0]++;
+            } /* end else */
+        } /* end for */
+    } /* end else */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5PB_read() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5PB_write
+ *
+ * Purpose: Write data into the Page Buffer. If the page exists in the
+ *          cache, update it; otherwise read it from disk, update it, and
+ *          insert into cache.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Mohamad Chaarawi
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5PB_write(const H5F_io_info2_t *fio_info, H5FD_mem_t type, haddr_t addr,
+    size_t size, const void *buf)
+{
+    H5PB_t *page_buf;                   /* Page buffering info for this file */
+    H5PB_entry_t *page_entry;           /* Pointer to the corresponding page entry */
+    H5FD_io_info_t fdio_info;           /* File driver I/O info */
+    haddr_t first_page_addr, last_page_addr;    /* Addresses of the first and last pages covered by I/O */
+    haddr_t offset;
+    haddr_t search_addr;                /* Address of current page */
+    hsize_t num_touched_pages;          /* Number of pages accessed */
+    size_t access_size;
+    hbool_t bypass_pb = FALSE;          /* Whether to bypass page buffering */
+    hsize_t i;                          /* Local index variable */
+    herr_t  ret_value = SUCCEED;        /* Return value */
+
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity checks */
+    HDassert(fio_info);
+    HDassert(fio_info->f);
+
+    /* Get pointer to page buffer info for this file */
+    page_buf = fio_info->f->shared->page_buf;
+
+#ifdef H5_HAVE_PARALLEL
+    if(H5F_HAS_FEATURE(fio_info->f, H5FD_FEAT_HAS_MPI)) {
+#if 1
+        bypass_pb = TRUE;
+#else
+        /* MSC - why this stopped working ? */
+        int mpi_size;
+
+        if((mpi_size = H5F_mpi_get_size(fio_info->f)) < 0)
+            HGOTO_ERROR(H5E_PAGEBUF, H5E_CANTGET, FAIL, "can't retrieve MPI communicator size")
+        if(1 != mpi_size)
+            bypass_pb = TRUE;
+#endif
+    } /* end if */
+#endif
+
+    /* If page buffering is disabled, or the I/O size is larger than that of a
+     * single page, or if this is a parallel raw data access, bypass page
+     * buffering.
+     */
+    if(NULL == page_buf || size >= page_buf->page_size || bypass_pb) {
+        if(H5F__accum_write(fio_info, type, addr, size, buf) < 0)
+            HGOTO_ERROR(H5E_PAGEBUF, H5E_WRITEERROR, FAIL, "write through metadata accumulator failed")
+
+        /* Update statistics */
+        if(page_buf) {
+            if(type == H5FD_MEM_DRAW || type == H5FD_MEM_GHEAP)
+                page_buf->bypasses[1]++;
+            else
+                page_buf->bypasses[0]++;
+        } /* end if */
+
+        /* If page buffering is disabled, or if this is a large metadata access, 
+         * or if this is a parallel raw data access, we are done here
+         */
+        if(NULL == page_buf || (size >= page_buf->page_size && H5FD_MEM_DRAW != type) ||
+                (bypass_pb && H5FD_MEM_DRAW == type))
+            HGOTO_DONE(SUCCEED)
+
+#ifdef H5_HAVE_PARALLEL
+        if(bypass_pb) {
+            if(H5PB_update_entry(page_buf, addr, size, buf) > 0)
+                HGOTO_ERROR(H5E_PAGEBUF, H5E_CANTUPDATE, FAIL, "failed to update PB with metadata cache")
+            HGOTO_DONE(SUCCEED)
+        } /* end if */
+#endif
+    } /* end if */
+
+    /* Update statistics */
+    if(page_buf) {
+        if(type == H5FD_MEM_DRAW || type == H5FD_MEM_GHEAP)
+            page_buf->accesses[1]++;
+        else
+            page_buf->accesses[0]++;
+    } /* end if */
+
+    /* Calculate the aligned address of the first page */
+    first_page_addr = (addr / page_buf->page_size) * page_buf->page_size;
+
+    /* For raw data calculate the aligned address of the last page and
+     * the number of pages accessed if more than 1 page is accessed
+     */
+    if(H5FD_MEM_DRAW == type) {
+        last_page_addr = (addr + size - 1) / page_buf->page_size * page_buf->page_size;
+
+        /* how many pages does this write span */
+        num_touched_pages = (last_page_addr/page_buf->page_size + 1) - 
+            (first_page_addr / page_buf->page_size);
+        if(first_page_addr == last_page_addr) {
+            HDassert(1 == num_touched_pages);
+            last_page_addr = HADDR_UNDEF;
+        } /* end if */
+    } /* end if */
+    /* Otherwise set last page addr to HADDR_UNDEF */
+    else {
+        num_touched_pages = 1;
+        last_page_addr = HADDR_UNDEF;
+    } /* end else */
+
+    /* Translate to file driver I/O info object */
+    fdio_info.file = fio_info->f->shared->lf;
+    fdio_info.meta_dxpl = fio_info->meta_dxpl;
+    fdio_info.raw_dxpl = fio_info->raw_dxpl;
+
+    /* Check if existing pages for raw data need to be updated since raw data access is not atomic */
+    if(H5FD_MEM_DRAW == type && size >= page_buf->page_size) {
+        /* For each touched page, check if it exists in the page buffer, and
+         * update it with the data in the buffer to keep it up to date
+         */
+        for(i = 0; i < num_touched_pages; i++) {
+            search_addr = i * page_buf->page_size + first_page_addr;
+
+            /* Special handling for the first page if it is not a full page update */
+            if(i == 0 && first_page_addr != addr) {
+                /* Lookup the page in the skip list */
+                page_entry = (H5PB_entry_t *)H5SL_search(page_buf->slist_ptr, (void *)(&search_addr));
+                if(page_entry) {
+                    offset = addr - first_page_addr;
+                    HDassert(page_buf->page_size > offset);
+
+                    /* Update page's data */
+                    HDmemcpy((uint8_t *)page_entry->page_buf_ptr + offset, buf, page_buf->page_size - (size_t)offset);
+
+                    /* Mark page dirty and push to top of LRU */
+                    page_entry->is_dirty = TRUE;
+                    H5PB__MOVE_TO_TOP_LRU(page_buf, page_entry)
+                } /* end if */
+            } /* end if */
+            /* Special handling for the last page if it is not a full page update */
+            else if(num_touched_pages > 1 && i == (num_touched_pages - 1) && 
+                    (search_addr + page_buf->page_size) != (addr + size)) {
+                HDassert(search_addr+page_buf->page_size > addr+size);
+
+                /* Lookup the page in the skip list */
+                page_entry = (H5PB_entry_t *)H5SL_search(page_buf->slist_ptr, (void *)(&search_addr));
+                if(page_entry) {
+                    offset = (num_touched_pages - 2) * page_buf->page_size + 
+                        (page_buf->page_size - (addr - first_page_addr));
+
+                    /* Update page's data */
+                    HDmemcpy(page_entry->page_buf_ptr, (const uint8_t *)buf + offset, 
+                             (size_t)((addr + size) - last_page_addr));
+
+                    /* Mark page dirty and push to top of LRU */
+                    page_entry->is_dirty = TRUE;
+                    H5PB__MOVE_TO_TOP_LRU(page_buf, page_entry)
+                } /* end if */
+            } /* end else-if */
+            /* Discard all fully written pages from the page buffer */
+            else {
+                page_entry = (H5PB_entry_t *)H5SL_remove(page_buf->slist_ptr, (void *)(&search_addr));
+                if(page_entry) {
+                    /* Remove from LRU list */
+                    H5PB__REMOVE_LRU(page_buf, page_entry)
+
+                    /* Decrement page count of appropriate type */
+                    if(H5F_MEM_PAGE_DRAW == page_entry->type || H5F_MEM_PAGE_GHEAP == page_entry->type)
+                        page_buf->raw_count--;
+                    else
+                        page_buf->meta_count--;
+
+                    /* Free page info */
+                    page_entry->page_buf_ptr = H5FL_FAC_FREE(page_buf->page_fac, page_entry->page_buf_ptr);
+                    page_entry = H5FL_FREE(H5PB_entry_t, page_entry);
+                } /* end if */
+            } /* end else */
+        } /* end for */
+    } /* end if */
+    else {
+        /* An access could span 1 or 2 PBs at this point so we need to handle that */
+        HDassert(1 == num_touched_pages || 2 == num_touched_pages);
+        for(i = 0; i < num_touched_pages; i++) {
+            haddr_t buf_offset;
+
+            /* Calculate the aligned address of the page to search for it in the skip list */
+            search_addr = (0 == i ? first_page_addr : last_page_addr);
+
+            /* Calculate the access size if the access spans more than 1 page */
+            if(1 == num_touched_pages)
+                access_size = size;
+            else
+                access_size = (0 == i ? (size_t)(first_page_addr + page_buf->page_size - addr) : (size - access_size));
+
+            /* Lookup the page in the skip list */
+            page_entry = (H5PB_entry_t *)H5SL_search(page_buf->slist_ptr, (void *)(&search_addr));
+
+            /* If found */
+            if(page_entry) {
+                offset = (0 == i ? addr - page_entry->addr : 0);
+                buf_offset = (0 == i ? 0 : size - access_size);
+
+                /* Copy the requested data from the input buffer into the page */
+                HDmemcpy((uint8_t *)page_entry->page_buf_ptr + offset, (const uint8_t *)buf + buf_offset, access_size);
+
+                /* Mark page dirty and push to top of LRU */
+                page_entry->is_dirty = TRUE;
+                H5PB__MOVE_TO_TOP_LRU(page_buf, page_entry)
+
+                /* Update statistics */
+                if(type == H5FD_MEM_DRAW || type == H5FD_MEM_GHEAP)
+                    page_buf->hits[1]++;
+                else
+                    page_buf->hits[0]++;
+            } /* end if */
+            /* If not found */ 
+            else {
+                void *new_page_buf;
+                size_t page_size = page_buf->page_size;
+
+                /* Make space for new entry */
+                if((H5SL_count(page_buf->slist_ptr) * page_buf->page_size) >= page_buf->max_size) {
+                    htri_t can_make_space;
+
+                    /* Check if we can make space in page buffer */
+                    if((can_make_space = H5PB__make_space(fio_info, page_buf, type)) < 0)
+                        HGOTO_ERROR(H5E_PAGEBUF, H5E_NOSPACE, FAIL, "make space in Page buffer Failed")
+
+                    /* If make_space returns 0, then we can't use the page
+                     * buffer for this I/O and we need to bypass
+                     */
+                    if(0 == can_make_space) {
+                        HDassert(0 == i);
+
+                        /* Write to VFD and return */
+                        if(H5FD_write(&fdio_info, type, addr, size, buf) < 0)
+                            HGOTO_ERROR(H5E_PAGEBUF, H5E_WRITEERROR, FAIL, "driver write request failed")
+                        
+                        /* Break out of loop */
+                        break;
+                    } /* end if */
+                } /* end if */
+
+                /* Don't bother searching if there is no write access */
+                if(H5F_ACC_RDWR & H5F_INTENT(fio_info->f))
+                    /* Lookup & remove the page from the new skip list page if
+                     * it exists to see if this is a new page from the MF layer
+                     */
+                    page_entry = (H5PB_entry_t *)H5SL_remove(page_buf->mf_slist_ptr, (void *)(&search_addr));
+
+                /* Calculate offset into the buffer of the page and the user buffer */
+                offset = (0 == i ? addr - search_addr : 0);
+                buf_offset = (0 == i ? 0 : size - access_size);
+
+                /* If found, then just update the buffer pointer to the newly allocate buffer */
+                if(page_entry) {
+                    /* Allocate space for the page buffer */
+                    if(NULL == (new_page_buf = H5FL_FAC_MALLOC(page_buf->page_fac)))
+                        HGOTO_ERROR(H5E_PAGEBUF, H5E_CANTALLOC, FAIL, "memory allocation failed for page buffer entry")
+                    HDmemset(new_page_buf, 0, (size_t)offset);
+                    HDmemset((uint8_t *)new_page_buf + offset + access_size, 0, page_size - ((size_t)offset + access_size));
+
+                    page_entry->page_buf_ptr = new_page_buf;
+
+                    /* Update statistics */
+                    if(type == H5FD_MEM_DRAW || type == H5FD_MEM_GHEAP)
+                        page_buf->hits[1]++;
+                    else
+                        page_buf->hits[0]++;
+                } /* end if */
+                /* Otherwise read page through the VFD layer, but make sure we don't read past the EOA. */
+                else {
+                    haddr_t eoa, eof = HADDR_UNDEF;
+
+                    /* Allocate space for the page buffer */
+                    if(NULL == (new_page_buf = H5FL_FAC_CALLOC(page_buf->page_fac)))
+                        HGOTO_ERROR(H5E_PAGEBUF, H5E_CANTALLOC, FAIL, "memory allocation failed for page buffer entry")
+
+                    /* Create the new loaded PB entry */
+                    if(NULL == (page_entry = H5FL_CALLOC(H5PB_entry_t)))
+                        HGOTO_ERROR(H5E_PAGEBUF, H5E_CANTALLOC, FAIL, "memory allocation failed")
+
+                    page_entry->page_buf_ptr = new_page_buf;
+                    page_entry->addr = search_addr;
+                    page_entry->type = (H5F_mem_page_t)type;
+
+                    /* Retrieve the 'eoa' for the file */
+                    if(HADDR_UNDEF == (eoa = H5F_get_eoa(fio_info->f, type)))
+                        HGOTO_ERROR(H5E_PAGEBUF, H5E_CANTGET, FAIL, "driver get_eoa request failed")
+
+                    /* If the entire page falls outside the EOA, then fail */
+                    if(search_addr > eoa)
+                        HGOTO_ERROR(H5E_PAGEBUF, H5E_BADVALUE, FAIL, "writing to a page that is outside the file EOA")
+
+                    /* Retrieve the 'eof' for the file - The MPI-VFD EOF
+                     * returned will most likely be HADDR_UNDEF, so skip
+                     * that check.
+                     */
+                    if(!H5F_HAS_FEATURE(fio_info->f, H5FD_FEAT_HAS_MPI))
+                        if(HADDR_UNDEF == (eof = H5FD_get_eof(fio_info->f->shared->lf, H5FD_MEM_DEFAULT)))
+                            HGOTO_ERROR(H5E_PAGEBUF, H5E_CANTGET, FAIL, "driver get_eof request failed")
+
+                    /* Adjust the read size to not go beyond the EOA */
+                    if(search_addr + page_size > eoa)
+                        page_size = (size_t)(eoa - search_addr);
+
+                    if(search_addr < eof) {
+                        if(H5FD_read(&fdio_info, type, search_addr, page_size, new_page_buf) < 0)
+                            HGOTO_ERROR(H5E_PAGEBUF, H5E_READERROR, FAIL, "driver read request failed")
+
+                        /* Update statistics */
+                        if(type == H5FD_MEM_DRAW || type == H5FD_MEM_GHEAP)
+                            page_buf->misses[1]++;
+                        else
+                            page_buf->misses[0]++;
+                    } /* end if */
+                } /* end else */
+
+                /* Copy the requested data from the page into the input buffer */
+                HDmemcpy((uint8_t *)new_page_buf + offset, (const uint8_t *)buf+buf_offset, access_size);
+
+                /* Page is dirty now */
+                page_entry->is_dirty = TRUE;
+
+                /* Insert page into PB, evicting other pages as necessary */
+                if(H5PB__insert_entry(page_buf, page_entry) < 0)
+                    HGOTO_ERROR(H5E_PAGEBUF, H5E_CANTSET, FAIL, "error inserting new page in page buffer")
+            } /* end else */
+        } /* end for */
+    } /* end else */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5PB_write() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5PB__insert_entry()
+ *
+ * Purpose: ??? 
+ *
+ *          This function was created without documentation.
+ *          What follows is my best understanding of Mohamad's intent.
+ *
+ *	    Insert the supplied page into the page buffer, both the
+ *          skip list and the LRU.
+ *
+ *          As best I can tell, this function imposes no limit on the
+ *          number of entries in the page buffer beyond an assertion
+ *          failure it the page count exceeds the limit.
+ *
+ *                                               JRM -- 12/22/16
+ *
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Mohamad Chaarawi
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t 
+H5PB__insert_entry(H5PB_t *page_buf, H5PB_entry_t *page_entry)
+{
+    herr_t ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_STATIC
+
+    /* Insert entry in skip list */
+    if(H5SL_insert(page_buf->slist_ptr, page_entry, &(page_entry->addr)) < 0)
+        HGOTO_ERROR(H5E_PAGEBUF, H5E_CANTINSERT, FAIL, "can't insert entry in skip list")
+    HDassert(H5SL_count(page_buf->slist_ptr) * page_buf->page_size <= page_buf->max_size);
+
+    /* Increment appropriate page count */
+    if(H5F_MEM_PAGE_DRAW == page_entry->type || H5F_MEM_PAGE_GHEAP == page_entry->type)
+        page_buf->raw_count++;
+    else
+        page_buf->meta_count++;
+
+    /* Insert entry in LRU */
+    H5PB__INSERT_LRU(page_buf, page_entry)
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5PB__insert_entry() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5PB__make_space()
+ *
+ * Purpose: ??? 
+ *
+ *          This function was created without documentation.
+ *          What follows is my best understanding of Mohamad's intent.
+ *
+ *          If necessary and if possible, evict a page from the page 
+ *          buffer to make space for the supplied page.  Depending on 
+ *	    the page buffer configuration and contents, and the page 
+ *          supplied this may or may not be possible.
+ *
+ *                                             JRM -- 12/22/16
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Mohamad Chaarawi
+ *
+ *-------------------------------------------------------------------------
+ */
+static htri_t 
+H5PB__make_space(const H5F_io_info2_t *fio_info, H5PB_t *page_buf,
+    H5FD_mem_t inserted_type)
+{
+    H5PB_entry_t *page_entry;   /* Pointer to page eviction candidate */
+    htri_t ret_value = TRUE;    /* Return value */
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity check */
+    HDassert(fio_info);
+    HDassert(page_buf);
+
+    /* Get oldest entry */
+    page_entry = page_buf->LRU_tail_ptr;
+
+    if(H5FD_MEM_DRAW == inserted_type) {
+        /* If threshould is 100% metadata and page buffer is full of
+           metadata, then we can't make space for raw data */
+        if(0 == page_buf->raw_count && page_buf->min_meta_count == page_buf->meta_count) {
+            HDassert(page_buf->meta_count * page_buf->page_size == page_buf->max_size);
+            HGOTO_DONE(FALSE)
+        } /* end if */
+
+        /* check the metadata threshold before evicting metadata items */
+        while(1) {
+            if(page_entry->prev && H5F_MEM_PAGE_META == page_entry->type && 
+                    page_buf->min_meta_count >= page_buf->meta_count)
+                page_entry = page_entry->prev;
+            else
+                break;
+        } /* end while */
+    } /* end if */
+    else {
+        /* If threshould is 100% raw data and page buffer is full of
+           raw data, then we can't make space for meta data */
+        if(0 == page_buf->meta_count && page_buf->min_raw_count == page_buf->raw_count) {
+            HDassert(page_buf->raw_count * page_buf->page_size == page_buf->max_size);
+            HGOTO_DONE(FALSE)
+        } /* end if */
+
+        /* check the raw data threshold before evicting raw data items */
+        while(1) {
+            if(page_entry->prev && (H5F_MEM_PAGE_DRAW == page_entry->type || H5F_MEM_PAGE_GHEAP == page_entry->type) && 
+                    page_buf->min_raw_count >= page_buf->raw_count)
+                page_entry = page_entry->prev;
+            else
+                break;
+        } /* end while */
+    } /* end else */
+
+    /* Remove from page index */
+    if(NULL == H5SL_remove(page_buf->slist_ptr, &(page_entry->addr)))
+        HGOTO_ERROR(H5E_PAGEBUF, H5E_BADVALUE, FAIL, "Tail Page Entry is not in skip list")
+
+    /* Remove entry from LRU list */
+    H5PB__REMOVE_LRU(page_buf, page_entry)
+    HDassert(H5SL_count(page_buf->slist_ptr) == page_buf->LRU_list_len);
+
+    /* Decrement appropriate page type counter */
+    if(H5F_MEM_PAGE_DRAW == page_entry->type || H5F_MEM_PAGE_GHEAP == page_entry->type)
+        page_buf->raw_count--;
+    else
+        page_buf->meta_count--;
+
+    /* Flush page if dirty */
+    if(page_entry->is_dirty)
+        if(H5PB__write_entry(fio_info, page_entry) < 0)
+            HGOTO_ERROR(H5E_PAGEBUF, H5E_WRITEERROR, FAIL, "file write failed")
+
+    /* Update statistics */
+    if(page_entry->type == H5F_MEM_PAGE_DRAW || H5F_MEM_PAGE_GHEAP == page_entry->type)
+        page_buf->evictions[1]++;
+    else
+        page_buf->evictions[0]++;
+
+    /* Release page */
+    page_entry->page_buf_ptr = H5FL_FAC_FREE(page_buf->page_fac, page_entry->page_buf_ptr);
+    page_entry = H5FL_FREE(H5PB_entry_t, page_entry);
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5PB__make_space() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5PB__write_entry()
+ *
+ * Purpose: ??? 
+ *
+ *          This function was created without documentation.
+ *          What follows is my best understanding of Mohamad's intent.
+ *
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Mohamad Chaarawi
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5PB__write_entry(const H5F_io_info2_t *fio_info, H5PB_entry_t *page_entry)
+{
+    haddr_t eoa;                    /* Current EOA for the file */
+    herr_t ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_STATIC
+
+    /* Sanity check */
+    HDassert(fio_info);
+    HDassert(fio_info->f);
+    HDassert(page_entry);
+
+    /* Retrieve the 'eoa' for the file */
+    if(HADDR_UNDEF == (eoa = H5F_get_eoa(fio_info->f, page_entry->type)))
+        HGOTO_ERROR(H5E_PAGEBUF, H5E_CANTGET, FAIL, "driver get_eoa request failed")
+
+    /* If the starting address of the page is larger than
+     * the EOA, then the entire page is discarded without writing.
+     */
+    if(page_entry->addr <= eoa) {
+        H5FD_io_info_t fdio_info;           /* File driver I/O info */
+        size_t page_size = fio_info->f->shared->page_buf->page_size;
+
+        /* Adjust the page length if it exceeds the EOA */
+        if((page_entry->addr + page_size) > eoa)
+            page_size = (size_t)(eoa - page_entry->addr);
+
+        /* Translate to file driver I/O info object */
+        fdio_info.file = fio_info->f->shared->lf;
+        fdio_info.meta_dxpl = fio_info->meta_dxpl;
+        fdio_info.raw_dxpl = fio_info->raw_dxpl;
+
+        if(H5FD_write(&fdio_info, page_entry->type, page_entry->addr, page_size, page_entry->page_buf_ptr) < 0)
+            HGOTO_ERROR(H5E_PAGEBUF, H5E_WRITEERROR, FAIL, "file write failed")
+    } /* end if */
+
+    page_entry->is_dirty = FALSE;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5PB__write_entry() */
+
diff --git a/src/H5PBmodule.h b/src/H5PBmodule.h
new file mode 100644
index 0000000..35da3f6
--- /dev/null
+++ b/src/H5PBmodule.h
@@ -0,0 +1,34 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the files COPYING and Copyright.html.  COPYING can be found at the root   *
+ * of the source code distribution tree; Copyright.html can be found at the  *
+ * root level of an installed copy of the electronic HDF5 document set and   *
+ * is linked from the top-level documents page.  It can also be found at     *
+ * http://hdfgroup.org/HDF5/doc/Copyright.html.  If you do not have          *
+ * access to either file, you may request a copy from help@hdfgroup.org.     *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*
+ * Programmer:	Quincey Koziol <koziol@hdfgroup.org>
+ *		Saturday, September 12, 2015
+ *
+ * Purpose:	This file contains declarations which define macros for the
+ *		H5PB package.  Including this header means that the source file
+ *		is part of the H5PB package.
+ */
+#ifndef _H5PBmodule_H
+#define _H5PBmodule_H
+
+/* Define the proper control macros for the generic FUNC_ENTER/LEAVE and error
+ *      reporting macros.
+ */
+#define H5PB_MODULE
+#define H5_MY_PKG       H5PB
+#define H5_MY_PKG_ERR   H5E_RESOURCE
+#define H5_MY_PKG_INIT  NO
+
+#endif /* _H5PBmodule_H */
diff --git a/src/H5PBpkg.h b/src/H5PBpkg.h
new file mode 100644
index 0000000..976f18d
--- /dev/null
+++ b/src/H5PBpkg.h
@@ -0,0 +1,60 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * Copyright by the Board of Trustees of the University of Illinois.         *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the files COPYING and Copyright.html.  COPYING can be found at the root   *
+ * of the source code distribution tree; Copyright.html can be found at the  *
+ * root level of an installed copy of the electronic HDF5 document set and   *
+ * is linked from the top-level documents page.  It can also be found at     *
+ * http://hdfgroup.org/HDF5/doc/Copyright.html.  If you do not have          *
+ * access to either file, you may request a copy from help@hdfgroup.org.     *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#if !(defined H5PB_FRIEND || defined H5PB_MODULE)
+#error "Do not include this file outside the H5PB package!"
+#endif
+
+#ifndef _H5PBpkg_H
+#define _H5PBpkg_H
+
+/* Get package's private header */
+#include "H5PBprivate.h"
+
+/* Other private headers needed by this file */
+
+/**************************/
+/* Package Private Macros */
+/**************************/
+
+
+/****************************/
+/* Package Private Typedefs */
+/****************************/
+
+typedef struct H5PB_entry_t {
+    void            *page_buf_ptr;      /* Pointer to the buffer containing the data */
+    haddr_t	    addr;               /* Address of the page in the file */
+    H5F_mem_page_t  type;               /* Type of the page entry (H5F_MEM_PAGE_RAW/META) */
+    hbool_t         is_dirty;           /* Flag indicating whether the page has dirty data or not */
+
+    /* Fields supporting replacement policies */
+    struct H5PB_entry_t     *next;      /* next pointer in the LRU list */
+    struct H5PB_entry_t     *prev;      /* previous pointer in the LRU list */
+} H5PB_entry_t;
+
+
+/*****************************/
+/* Package Private Variables */
+/*****************************/
+
+
+/******************************/
+/* Package Private Prototypes */
+/******************************/
+
+
+#endif /* _H5PBpkg_H */
+
diff --git a/src/H5PBprivate.h b/src/H5PBprivate.h
new file mode 100644
index 0000000..3b5dcae
--- /dev/null
+++ b/src/H5PBprivate.h
@@ -0,0 +1,108 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by The HDF Group.                                               *
+ * Copyright by the Board of Trustees of the University of Illinois.         *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the files COPYING and Copyright.html.  COPYING can be found at the root   *
+ * of the source code distribution tree; Copyright.html can be found at the  *
+ * root level of an installed copy of the electronic HDF5 document set and   *
+ * is linked from the top-level documents page.  It can also be found at     *
+ * http://hdfgroup.org/HDF5/doc/Copyright.html.  If you do not have          *
+ * access to either file, you may request a copy from help@hdfgroup.org.     *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+/*-------------------------------------------------------------------------
+ *
+ * Created:		H5PBprivate.h
+ *			June 2014
+ *			Mohamad Chaarawi
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef _H5PBprivate_H
+#define _H5PBprivate_H
+
+/* Include package's public header */
+#ifdef NOT_YET
+#include "H5PBpublic.h"
+#endif /* NOT_YET */
+
+/* Private headers needed by this header */
+#include "H5private.h"		/* Generic Functions			*/
+#include "H5Fprivate.h"		/* File access				*/
+#include "H5FLprivate.h"	/* Free Lists                           */
+#include "H5SLprivate.h"	/* Skip List				*/
+
+
+/**************************/
+/* Library Private Macros */
+/**************************/
+
+
+/****************************/
+/* Library Private Typedefs */
+/****************************/
+
+/* Forward declaration for a page buffer entry */
+struct H5PB_entry_t;
+
+/* Typedef for the main structure for the page buffer */
+typedef struct H5PB_t {
+    size_t              max_size;           /* The total page buffer size */
+    size_t              page_size;          /* Size of a single page */
+    unsigned            min_meta_perc;      /* Minimum ratio of metadata entries required before evicting meta entries */
+    unsigned            min_raw_perc;       /* Minimum ratio of raw data entries required before evicting raw entries */
+    unsigned            meta_count;         /* Number of entries for metadata */
+    unsigned            raw_count;          /* Number of entries for raw data */
+    unsigned            min_meta_count;     /* Minimum # of entries for metadata */
+    unsigned            min_raw_count;      /* Minimum # of entries for raw data */
+
+    H5SL_t              *slist_ptr;         /* Skip list with all the active page entries */
+    H5SL_t              *mf_slist_ptr;      /* Skip list containing newly allocated page entries inserted from the MF layer */
+
+    size_t              LRU_list_len;       /* Number of entries in the LRU (identical to slist_ptr count) */
+    struct H5PB_entry_t *LRU_head_ptr;      /* Head pointer of the LRU */
+    struct H5PB_entry_t *LRU_tail_ptr;      /* Tail pointer of the LRU */
+
+    H5FL_fac_head_t     *page_fac;           /* Factory for allocating pages */
+
+    /* Statistics */
+    unsigned            accesses[2];
+    unsigned            hits[2];
+    unsigned            misses[2];
+    unsigned            evictions[2];
+    unsigned            bypasses[2];
+} H5PB_t;
+
+/*****************************/
+/* Library-private Variables */
+/*****************************/
+
+
+/***************************************/
+/* Library-private Function Prototypes */
+/***************************************/
+
+/* General routines */
+H5_DLL herr_t H5PB_create(H5F_t *file, size_t page_buffer_size, unsigned page_buf_min_meta_perc, unsigned page_buf_min_raw_perc);
+H5_DLL herr_t H5PB_flush(const H5F_io_info2_t *fio_info);
+H5_DLL herr_t H5PB_dest(H5F_t *file);
+H5_DLL herr_t H5PB_add_new_page(H5F_t *f, H5FD_mem_t type, haddr_t page_addr);
+H5_DLL herr_t H5PB_update_entry(H5PB_t *page_buf, haddr_t addr, size_t size, const void *buf);
+H5_DLL herr_t H5PB_remove_entry(const H5F_t *f, haddr_t addr);
+H5_DLL herr_t H5PB_read(const H5F_io_info2_t *fio_info, H5FD_mem_t type,
+    haddr_t addr, size_t size, void *buf/*out*/);
+H5_DLL herr_t H5PB_write(const H5F_io_info2_t *f, H5FD_mem_t type, haddr_t addr,
+    size_t size, const void *buf);
+
+/* Statistics routines */
+H5_DLL herr_t H5PB_reset_stats(H5PB_t *page_buf);
+H5_DLL herr_t H5PB_get_stats(const H5PB_t *page_buf, unsigned accesses[2],
+    unsigned hits[2], unsigned misses[2], unsigned evictions[2], unsigned bypasses[2]);
+H5_DLL herr_t H5PB_print_stats(const H5PB_t *page_buf);
+
+#endif /* !_H5PBprivate_H */
+
diff --git a/src/H5Pdeprec.c b/src/H5Pdeprec.c
index ecf2bea..d225dfa 100644
--- a/src/H5Pdeprec.c
+++ b/src/H5Pdeprec.c
@@ -488,5 +488,135 @@ done:
     FUNC_LEAVE_API(ret_value)
 } /* end H5Pget_version() */
 
+/*-------------------------------------------------------------------------
+ * Function:	H5Pset_file_space
+ *
+ * Purpose:	    It is mapped to H5Pset_file_space_strategy().
+ *
+ * Return:	    Non-negative on success/Negative on failure
+ *
+ * Programmer:	Vailin Choi; Jan 2017
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Pset_file_space(hid_t plist_id, H5F_file_space_type_t strategy, hsize_t threshold)
+{
+
+    H5F_fspace_strategy_t new_strategy;                     /* File space strategy type */
+    hbool_t new_persist = H5F_FREE_SPACE_PERSIST_DEF;       /* Persisting free-space or not */
+    hsize_t new_threshold = H5F_FREE_SPACE_THRESHOLD_DEF;   /* Free-space section threshold */
+    H5F_file_space_type_t in_strategy = strategy;           /* Input strategy */
+    hsize_t in_threshold = threshold;                       /* Input threshold */
+    herr_t ret_value = SUCCEED;                             /* Return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE3("e", "iFfh", plist_id, strategy, threshold);
+
+    if((unsigned)in_strategy >= H5F_FILE_SPACE_NTYPES)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid strategy")
+    /*
+     *  For 1.10.0 H5Pset_file_space:
+     *      If strategy is zero, the property is not changed; 
+     *      the existing strategy is retained.
+     *      If threshold is zero, the property is not changed; 
+     *      the existing threshold is retained.
+     */
+    if(!in_strategy)
+        H5Pget_file_space(plist_id, &in_strategy, NULL);
+    if(!in_threshold)
+        H5Pget_file_space(plist_id, NULL, &in_threshold);
+
+    switch(in_strategy) {
+        case H5F_FILE_SPACE_ALL_PERSIST:
+            new_strategy = H5F_FSPACE_STRATEGY_FSM_AGGR;
+            new_persist = TRUE;
+            new_threshold = in_threshold;
+            break;
+    
+        case H5F_FILE_SPACE_ALL:
+            new_strategy = H5F_FSPACE_STRATEGY_FSM_AGGR;
+            new_threshold = in_threshold;
+            break;
+
+        case H5F_FILE_SPACE_AGGR_VFD:
+            new_strategy = H5F_FSPACE_STRATEGY_AGGR;
+            break;
+
+        case H5F_FILE_SPACE_VFD:
+            new_strategy = H5F_FSPACE_STRATEGY_NONE;
+            break;
+        
+        case H5F_FILE_SPACE_NTYPES:
+        case H5F_FILE_SPACE_DEFAULT:
+        default:
+            HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid file space strategy")
+    }
+
+    if(H5Pset_file_space_strategy(plist_id, new_strategy, new_persist, new_threshold) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set file space strategy")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* H5Pset_file_space() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Pget_file_space
+ *
+ * Purpose:	    It is mapped to H5Pget_file_space_strategy().
+ *
+ * Return:	    Non-negative on success/Negative on failure
+ *
+ * Programmer:	Vailin Choi; Jan 2017
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Pget_file_space(hid_t plist_id, H5F_file_space_type_t *strategy, hsize_t *threshold)
+{
+    H5F_fspace_strategy_t new_strategy;     /* File space strategy type */
+    hbool_t new_persist;                    /* Persisting free-space or not */
+    hsize_t new_threshold;                  /* Free-space section threshold */
+    herr_t ret_value = SUCCEED;             /* Return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE3("e", "i*Ff*h", plist_id, strategy, threshold);
+
+    /* Get current file space info */
+    if(H5Pget_file_space_strategy(plist_id, &new_strategy, &new_persist, &new_threshold) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get file space strategy")
+
+    /* Get value(s) */
+    if(strategy) {
+        switch(new_strategy) {
+
+            case H5F_FSPACE_STRATEGY_FSM_AGGR:
+                if(new_persist)
+                    *strategy = H5F_FILE_SPACE_ALL_PERSIST;
+                else
+                    *strategy = H5F_FILE_SPACE_ALL;
+            break;
+
+            case H5F_FSPACE_STRATEGY_AGGR:
+                *strategy = H5F_FILE_SPACE_AGGR_VFD;
+                break;
+
+            case H5F_FSPACE_STRATEGY_NONE:
+                *strategy = H5F_FILE_SPACE_VFD;
+                break;
+
+            case H5F_FSPACE_STRATEGY_PAGE:
+            case H5F_FSPACE_STRATEGY_NTYPES:
+            default:
+                HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid file space strategy")
+        }
+    }
+
+    if(threshold)
+        *threshold = new_threshold;
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* H5Pget_file_space() */
 #endif /* H5_NO_DEPRECATED_SYMBOLS */
 
diff --git a/src/H5Pfapl.c b/src/H5Pfapl.c
index 7ea0fe0..7865fdf 100644
--- a/src/H5Pfapl.c
+++ b/src/H5Pfapl.c
@@ -80,18 +80,18 @@
 #define H5F_ACS_PREEMPT_READ_CHUNKS_DEC         H5P__decode_double
 /* Definition for threshold for alignment */
 #define H5F_ACS_ALIGN_THRHD_SIZE                sizeof(hsize_t)
-#define H5F_ACS_ALIGN_THRHD_DEF                 1
+#define H5F_ACS_ALIGN_THRHD_DEF                 H5F_ALIGN_THRHD_DEF
 #define H5F_ACS_ALIGN_THRHD_ENC                 H5P__encode_hsize_t
 #define H5F_ACS_ALIGN_THRHD_DEC                 H5P__decode_hsize_t
 /* Definition for alignment */
 #define H5F_ACS_ALIGN_SIZE                      sizeof(hsize_t)
-#define H5F_ACS_ALIGN_DEF                       1
+#define H5F_ACS_ALIGN_DEF                       H5F_ALIGN_DEF
 #define H5F_ACS_ALIGN_ENC                       H5P__encode_hsize_t
 #define H5F_ACS_ALIGN_DEC                       H5P__decode_hsize_t
 /* Definition for minimum metadata allocation block size (when
    aggregating metadata allocations. */
 #define H5F_ACS_META_BLOCK_SIZE_SIZE            sizeof(hsize_t)
-#define H5F_ACS_META_BLOCK_SIZE_DEF             2048
+#define H5F_ACS_META_BLOCK_SIZE_DEF             H5F_META_BLOCK_SIZE_DEF
 #define H5F_ACS_META_BLOCK_SIZE_ENC             H5P__encode_hsize_t
 #define H5F_ACS_META_BLOCK_SIZE_DEC             H5P__decode_hsize_t
 /* Definition for maximum sieve buffer size (when data sieving
@@ -103,7 +103,7 @@
 /* Definition for minimum "small data" allocation block size (when
    aggregating "small" raw data allocations. */
 #define H5F_ACS_SDATA_BLOCK_SIZE_SIZE           sizeof(hsize_t)
-#define H5F_ACS_SDATA_BLOCK_SIZE_DEF            2048
+#define H5F_ACS_SDATA_BLOCK_SIZE_DEF            H5F_SDATA_BLOCK_SIZE_DEF
 #define H5F_ACS_SDATA_BLOCK_SIZE_ENC            H5P__encode_hsize_t
 #define H5F_ACS_SDATA_BLOCK_SIZE_DEC            H5P__decode_hsize_t
 /* Definition for garbage-collect references */
@@ -231,6 +231,21 @@
 #define H5F_ACS_META_CACHE_INIT_IMAGE_CONFIG_ENC  H5P__facc_cache_image_config_enc
 #define H5F_ACS_META_CACHE_INIT_IMAGE_CONFIG_DEC  H5P__facc_cache_image_config_dec
 #define H5F_ACS_META_CACHE_INIT_IMAGE_CONFIG_CMP  H5P__facc_cache_image_config_cmp
+/* Definition for total size of page buffer(bytes) */
+#define H5F_ACS_PAGE_BUFFER_SIZE_SIZE           sizeof(size_t)
+#define H5F_ACS_PAGE_BUFFER_SIZE_DEF            0
+#define H5F_ACS_PAGE_BUFFER_SIZE_ENC            H5P__encode_size_t
+#define H5F_ACS_PAGE_BUFFER_SIZE_DEC            H5P__decode_size_t
+/* Definition for minimum metadata size of page buffer(bytes) */
+#define H5F_ACS_PAGE_BUFFER_MIN_META_PERC_SIZE           sizeof(unsigned)
+#define H5F_ACS_PAGE_BUFFER_MIN_META_PERC_DEF            0
+#define H5F_ACS_PAGE_BUFFER_MIN_META_PERC_ENC            H5P__encode_unsigned
+#define H5F_ACS_PAGE_BUFFER_MIN_META_PERC_DEC            H5P__decode_unsigned
+/* Definition for minimum raw data size of page buffer(bytes) */
+#define H5F_ACS_PAGE_BUFFER_MIN_RAW_PERC_SIZE           sizeof(unsigned)
+#define H5F_ACS_PAGE_BUFFER_MIN_RAW_PERC_DEF            0
+#define H5F_ACS_PAGE_BUFFER_MIN_RAW_PERC_ENC            H5P__encode_unsigned
+#define H5F_ACS_PAGE_BUFFER_MIN_RAW_PERC_DEC            H5P__decode_unsigned
 
 
 /******************/
@@ -359,6 +374,9 @@ static const H5P_coll_md_read_flag_t H5F_def_coll_md_read_flag_g = H5F_ACS_COLL_
 static const hbool_t H5F_def_coll_md_write_flag_g = H5F_ACS_COLL_MD_WRITE_FLAG_DEF;  /* Default setting for the collective metedata write flag */
 #endif /* H5_HAVE_PARALLEL */
 static const H5AC_cache_image_config_t H5F_def_mdc_initCacheImageCfg_g = H5F_ACS_META_CACHE_INIT_IMAGE_CONFIG_DEF;  /* Default metadata cache image settings */
+static const size_t H5F_def_page_buf_size_g = H5F_ACS_PAGE_BUFFER_SIZE_DEF;      /* Default page buffer size */
+static const unsigned H5F_def_page_buf_min_meta_perc_g = H5F_ACS_PAGE_BUFFER_MIN_META_PERC_DEF;      /* Default page buffer minimum metadata size */
+static const unsigned H5F_def_page_buf_min_raw_perc_g = H5F_ACS_PAGE_BUFFER_MIN_RAW_PERC_DEF;      /* Default page buffer minumum raw data size */
 
 
 /*-------------------------------------------------------------------------
@@ -574,6 +592,22 @@ H5P__facc_reg_prop(H5P_genclass_t *pclass)
             NULL, NULL, H5F_ACS_META_CACHE_INIT_IMAGE_CONFIG_CMP, NULL) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
 
+    /* Register the size of the page buffer size */
+    if(H5P_register_real(pclass, H5F_ACS_PAGE_BUFFER_SIZE_NAME, H5F_ACS_PAGE_BUFFER_SIZE_SIZE, &H5F_def_page_buf_size_g, 
+            NULL, NULL, NULL, H5F_ACS_PAGE_BUFFER_SIZE_ENC, H5F_ACS_PAGE_BUFFER_SIZE_DEC, 
+            NULL, NULL, NULL, NULL) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
+    /* Register the size of the page buffer minimum metadata size */
+    if(H5P_register_real(pclass, H5F_ACS_PAGE_BUFFER_MIN_META_PERC_NAME, H5F_ACS_PAGE_BUFFER_MIN_META_PERC_SIZE, &H5F_def_page_buf_min_meta_perc_g, 
+            NULL, NULL, NULL, H5F_ACS_PAGE_BUFFER_MIN_META_PERC_ENC, H5F_ACS_PAGE_BUFFER_MIN_META_PERC_DEC, 
+            NULL, NULL, NULL, NULL) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
+    /* Register the size of the page buffer minimum raw data size */
+    if(H5P_register_real(pclass, H5F_ACS_PAGE_BUFFER_MIN_RAW_PERC_NAME, H5F_ACS_PAGE_BUFFER_MIN_RAW_PERC_SIZE, &H5F_def_page_buf_min_raw_perc_g, 
+            NULL, NULL, NULL, H5F_ACS_PAGE_BUFFER_MIN_RAW_PERC_ENC, H5F_ACS_PAGE_BUFFER_MIN_RAW_PERC_DEC, 
+            NULL, NULL, NULL, NULL) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
+
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5P__facc_reg_prop() */
@@ -4681,3 +4715,93 @@ done:
 } /* end H5Pget_coll_metadata_write() */
 #endif /* H5_HAVE_PARALLEL */
 
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Pset_page_buffer_size
+ *
+ * Purpose:     Set the maximum page buffering size. This has to be a
+ *              multiple of the page allocation size which must be enabled;
+ *              otherwise file create/open will fail.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Mohamad Chaarawi
+ *              June 2015
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Pset_page_buffer_size(hid_t plist_id, size_t buf_size, unsigned min_meta_perc, unsigned min_raw_perc)
+{
+    H5P_genplist_t *plist;      /* Property list pointer */
+    herr_t ret_value = SUCCEED;   /* return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE4("e", "izIuIu", plist_id, buf_size, min_meta_perc, min_raw_perc);
+
+    /* Get the plist structure */
+    if(NULL == (plist = H5P_object_verify(plist_id, H5P_FILE_ACCESS)))
+        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't find object for ID")
+
+    if(min_meta_perc > 100)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "Minimum metadata fractions must be between 0 and 100 inclusive")
+    if(min_raw_perc > 100)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "Minimum rawdata fractions must be between 0 and 100 inclusive")
+
+    if(min_meta_perc + min_raw_perc > 100)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "Sum of minimum metadata and raw data fractions can't be bigger than 100");
+
+    /* Set size */
+    if(H5P_set(plist, H5F_ACS_PAGE_BUFFER_SIZE_NAME, &buf_size) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET,FAIL, "can't set page buffer size")
+    if(H5P_set(plist, H5F_ACS_PAGE_BUFFER_MIN_META_PERC_NAME, &min_meta_perc) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET,FAIL, "can't set percentage of min metadata entries")
+    if(H5P_set(plist, H5F_ACS_PAGE_BUFFER_MIN_RAW_PERC_NAME, &min_raw_perc) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET,FAIL, "can't set percentage of min rawdata entries")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* end H5Pset_page_buffer_size() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Pget_page_buffer_size
+ *
+ * Purpose:	Retrieves the maximum page buffer size.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Mohamad Chaarawi
+ *              June 2015
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Pget_page_buffer_size(hid_t plist_id, size_t *buf_size, unsigned *min_meta_perc, unsigned *min_raw_perc)
+{
+    H5P_genplist_t *plist;      /* Property list pointer */
+    herr_t ret_value = SUCCEED;   /* return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE4("e", "i*z*Iu*Iu", plist_id, buf_size, min_meta_perc, min_raw_perc);
+
+    /* Get the plist structure */
+    if(NULL == (plist = H5P_object_verify(plist_id, H5P_FILE_ACCESS)))
+        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't find object for ID")
+
+    /* Get size */
+
+    if(buf_size)
+        if(H5P_get(plist, H5F_ACS_PAGE_BUFFER_SIZE_NAME, buf_size) < 0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET,FAIL, "can't get page buffer size")
+    if(min_meta_perc)
+        if(H5P_get(plist, H5F_ACS_PAGE_BUFFER_MIN_META_PERC_NAME, min_meta_perc) < 0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET,FAIL, "can't get page buffer minimum metadata percent")
+    if(min_raw_perc)
+        if(H5P_get(plist, H5F_ACS_PAGE_BUFFER_MIN_RAW_PERC_NAME, min_raw_perc) < 0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET,FAIL, "can't get page buffer minimum raw data percent")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* end H5Pget_page_buffer_size() */
+
diff --git a/src/H5Pfcpl.c b/src/H5Pfcpl.c
index d451982..c778801 100644
--- a/src/H5Pfcpl.c
+++ b/src/H5Pfcpl.c
@@ -97,14 +97,23 @@
 #define H5F_CRT_SHMSG_BTREE_MIN_ENC     H5P__encode_unsigned
 #define H5F_CRT_SHMSG_BTREE_MIN_DEC     H5P__decode_unsigned
 /* Definitions for file space handling strategy */
-#define H5F_CRT_FILE_SPACE_STRATEGY_SIZE       sizeof(unsigned)
-#define H5F_CRT_FILE_SPACE_STRATEGY_DEF        H5F_FILE_SPACE_STRATEGY_DEF
-#define H5F_CRT_FILE_SPACE_STRATEGY_ENC        H5P__encode_unsigned
-#define H5F_CRT_FILE_SPACE_STRATEGY_DEC        H5P__decode_unsigned
-#define H5F_CRT_FREE_SPACE_THRESHOLD_SIZE      sizeof(hsize_t)
-#define H5F_CRT_FREE_SPACE_THRESHOLD_DEF       H5F_FREE_SPACE_THRESHOLD_DEF
-#define H5F_CRT_FREE_SPACE_THRESHOLD_ENC       H5P__encode_hsize_t
-#define H5F_CRT_FREE_SPACE_THRESHOLD_DEC       H5P__decode_hsize_t
+#define H5F_CRT_FILE_SPACE_STRATEGY_SIZE        sizeof(H5F_fspace_strategy_t)
+#define H5F_CRT_FILE_SPACE_STRATEGY_DEF         H5F_FILE_SPACE_STRATEGY_DEF
+#define H5F_CRT_FILE_SPACE_STRATEGY_ENC         H5P__fcrt_fspace_strategy_enc
+#define H5F_CRT_FILE_SPACE_STRATEGY_DEC         H5P__fcrt_fspace_strategy_dec
+#define H5F_CRT_FREE_SPACE_PERSIST_SIZE         sizeof(hbool_t)
+#define H5F_CRT_FREE_SPACE_PERSIST_DEF          H5F_FREE_SPACE_PERSIST_DEF
+#define H5F_CRT_FREE_SPACE_PERSIST_ENC          H5P__encode_hbool_t
+#define H5F_CRT_FREE_SPACE_PERSIST_DEC          H5P__decode_hbool_t
+#define H5F_CRT_FREE_SPACE_THRESHOLD_SIZE       sizeof(hsize_t)
+#define H5F_CRT_FREE_SPACE_THRESHOLD_DEF        H5F_FREE_SPACE_THRESHOLD_DEF
+#define H5F_CRT_FREE_SPACE_THRESHOLD_ENC        H5P__encode_hsize_t
+#define H5F_CRT_FREE_SPACE_THRESHOLD_DEC        H5P__decode_hsize_t
+/* Definitions for file space page size in support of level-2 page caching */
+#define H5F_CRT_FILE_SPACE_PAGE_SIZE_SIZE       sizeof(hsize_t)
+#define H5F_CRT_FILE_SPACE_PAGE_SIZE_DEF        H5F_FILE_SPACE_PAGE_SIZE_DEF
+#define H5F_CRT_FILE_SPACE_PAGE_SIZE_ENC        H5P__encode_hsize_t
+#define H5F_CRT_FILE_SPACE_PAGE_SIZE_DEC        H5P__decode_hsize_t
 
 
 /******************/
@@ -131,6 +140,8 @@ static herr_t H5P__fcrt_shmsg_index_types_enc(const void *value, void **_pp, siz
 static herr_t H5P__fcrt_shmsg_index_types_dec(const void **_pp, void *value);
 static herr_t H5P__fcrt_shmsg_index_minsize_enc(const void *value, void **_pp, size_t *size);
 static herr_t H5P__fcrt_shmsg_index_minsize_dec(const void **_pp, void *value);
+static herr_t H5P__fcrt_fspace_strategy_enc(const void *value, void **_pp, size_t *size);
+static herr_t H5P__fcrt_fspace_strategy_dec(const void **_pp, void *_value);
 
 
 /*********************/
@@ -178,8 +189,10 @@ static const unsigned H5F_def_sohm_index_flags_g[H5O_SHMESG_MAX_NINDEXES]    = H
 static const unsigned H5F_def_sohm_index_minsizes_g[H5O_SHMESG_MAX_NINDEXES] = H5F_CRT_SHMSG_INDEX_MINSIZE_DEF;
 static const unsigned H5F_def_sohm_list_max_g  = H5F_CRT_SHMSG_LIST_MAX_DEF;
 static const unsigned H5F_def_sohm_btree_min_g  = H5F_CRT_SHMSG_BTREE_MIN_DEF;
-static const unsigned H5F_def_file_space_strategy_g = H5F_CRT_FILE_SPACE_STRATEGY_DEF;
+static const H5F_fspace_strategy_t H5F_def_file_space_strategy_g = H5F_CRT_FILE_SPACE_STRATEGY_DEF;
+static const hbool_t H5F_def_free_space_persist_g = H5F_CRT_FREE_SPACE_PERSIST_DEF;
 static const hsize_t H5F_def_free_space_threshold_g = H5F_CRT_FREE_SPACE_THRESHOLD_DEF;
+static const hsize_t H5F_def_file_space_page_size_g = H5F_CRT_FILE_SPACE_PAGE_SIZE_DEF;
 
 
 
@@ -267,12 +280,24 @@ H5P_fcrt_reg_prop(H5P_genclass_t *pclass)
             NULL, NULL, NULL, NULL) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
 
+    /* Register the free-space persist flag */
+    if(H5P_register_real(pclass, H5F_CRT_FREE_SPACE_PERSIST_NAME, H5F_CRT_FREE_SPACE_PERSIST_SIZE, &H5F_def_free_space_persist_g,
+            NULL, NULL, NULL, H5F_CRT_FREE_SPACE_PERSIST_ENC, H5F_CRT_FREE_SPACE_PERSIST_DEC,
+            NULL, NULL, NULL, NULL) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
+
     /* Register the free space section threshold */
     if(H5P_register_real(pclass, H5F_CRT_FREE_SPACE_THRESHOLD_NAME, H5F_CRT_FREE_SPACE_THRESHOLD_SIZE, &H5F_def_free_space_threshold_g, 
             NULL, NULL, NULL, H5F_CRT_FREE_SPACE_THRESHOLD_ENC, H5F_CRT_FREE_SPACE_THRESHOLD_DEC, 
             NULL, NULL, NULL, NULL) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
 
+    /* Register the file space page size */
+    if(H5P_register_real(pclass, H5F_CRT_FILE_SPACE_PAGE_SIZE_NAME, H5F_CRT_FILE_SPACE_PAGE_SIZE_SIZE, &H5F_def_file_space_page_size_g,
+            NULL, NULL, NULL, H5F_CRT_FILE_SPACE_PAGE_SIZE_ENC, H5F_CRT_FILE_SPACE_PAGE_SIZE_DEC,
+            NULL, NULL, NULL, NULL) < 0)
+         HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
+
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5P_fcrt_reg_prop() */
@@ -1246,15 +1271,13 @@ H5Pget_shared_mesg_phase_change(hid_t plist_id, unsigned *max_list, unsigned *mi
     if(NULL == (plist = H5P_object_verify(plist_id,H5P_FILE_CREATE)))
         HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't find object for ID");
 
-    /* Get value */
-    if (max_list) {
+    /* Get value(s) */
+    if(max_list)
         if(H5P_get(plist, H5F_CRT_SHMSG_LIST_MAX_NAME, max_list) < 0)
             HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get list maximum");
-    }
-    if (min_btree) {
+    if(min_btree)
         if(H5P_get(plist, H5F_CRT_SHMSG_BTREE_MIN_NAME, min_btree) < 0)
             HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get SOHM information");
-    }
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -1262,15 +1285,12 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Pset_file_space
+ * Function:	H5Pset_file_space_strategy
  *
- * Purpose:	Sets the strategy that the library employs in managing file space.
- *		If strategy is zero, the property is not changed; the existing
- *			strategy is retained.
- *		Sets the threshold value that the file's free space
- *			manager(s) will use to track free space sections.
- *		If threshold is zero, the property is not changed; the existing
- *			threshold is retained.
+ * Purpose:	Sets the "strategy" that the library employs in managing file space
+ *		    Sets the "persist" value as to persist free-space or not
+ *		    Sets the "threshold" value that the free space manager(s) will use to track free space sections.
+ *          Ignore "persist" and "threshold" for strategies that do not use free-space managers
  *
  * Return:	Non-negative on success/Negative on failure
  *
@@ -1279,15 +1299,16 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5Pset_file_space(hid_t plist_id, H5F_file_space_type_t strategy, hsize_t threshold)
+H5Pset_file_space_strategy(hid_t plist_id, H5F_fspace_strategy_t strategy, hbool_t persist, hsize_t threshold)
 {
     H5P_genplist_t *plist;              /* Property list pointer */
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
-    H5TRACE3("e", "iFfh", plist_id, strategy, threshold);
+    H5TRACE4("e", "iFfbh", plist_id, strategy, persist, threshold);
 
-    if((unsigned)strategy >= H5F_FILE_SPACE_NTYPES)
+    /* Check arguments */
+    if(strategy >= H5F_FSPACE_STRATEGY_NTYPES)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid strategy")
 
     /* Get the plist structure */
@@ -1295,24 +1316,28 @@ H5Pset_file_space(hid_t plist_id, H5F_file_space_type_t strategy, hsize_t thresh
         HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't find object for ID")
 
     /* Set value(s), if non-zero */
-    if(strategy)
-	if(H5P_set(plist, H5F_CRT_FILE_SPACE_STRATEGY_NAME, &strategy) < 0)
-	    HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't set file space strategy")
-    if(threshold)
-	if(H5P_set(plist, H5F_CRT_FREE_SPACE_THRESHOLD_NAME, &threshold) < 0)
-	    HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't set free-space threshold")
+    if(H5P_set(plist, H5F_CRT_FILE_SPACE_STRATEGY_NAME, &strategy) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set file space strategy")
+
+    /* Ignore persist and threshold settings for strategies that do not use FSM */
+    if(strategy ==  H5F_FSPACE_STRATEGY_FSM_AGGR || strategy == H5F_FSPACE_STRATEGY_PAGE) {
+        if(H5P_set(plist, H5F_CRT_FREE_SPACE_PERSIST_NAME, &persist) < 0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set free-space persisting status")
+
+        if(H5P_set(plist, H5F_CRT_FREE_SPACE_THRESHOLD_NAME, &threshold) < 0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set free-space threshold")
+    } /* end if */
 
 done:
     FUNC_LEAVE_API(ret_value)
-} /* H5Pset_file_space() */
+} /* H5Pset_file_space_strategy() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Pget_file_space
+ * Function:	H5Pget_file_space_strategy
  *
- * Purpose:	Retrieves the strategy that the library uses in managing file space.
- *		Retrieves the threshold value that the file's free space
- *			managers use to track free space sections.
+ * Purpose:	Retrieves the strategy, persist, and threshold that the library 
+ *          uses in managing file space.
  *
  * Return:	Non-negative on success/Negative on failure
  *
@@ -1321,13 +1346,13 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5Pget_file_space(hid_t plist_id, H5F_file_space_type_t *strategy, hsize_t *threshold)
+H5Pget_file_space_strategy(hid_t plist_id, H5F_fspace_strategy_t *strategy, hbool_t *persist, hsize_t *threshold)
 {
     H5P_genplist_t *plist;              /* Property list pointer */
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
-    H5TRACE3("e", "i*Ff*h", plist_id, strategy, threshold);
+    H5TRACE4("e", "i*Ff*b*h", plist_id, strategy, persist, threshold);
 
     /* Get the plist structure */
     if(NULL == (plist = H5P_object_verify(plist_id,H5P_FILE_CREATE)))
@@ -1337,11 +1362,158 @@ H5Pget_file_space(hid_t plist_id, H5F_file_space_type_t *strategy, hsize_t *thre
     if(strategy)
         if(H5P_get(plist, H5F_CRT_FILE_SPACE_STRATEGY_NAME, strategy) < 0)
             HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get file space strategy")
+    if(persist)
+        if(H5P_get(plist, H5F_CRT_FREE_SPACE_PERSIST_NAME, persist) < 0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get free-space persisting status")
     if(threshold)
         if(H5P_get(plist, H5F_CRT_FREE_SPACE_THRESHOLD_NAME, threshold) < 0)
             HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get free-space threshold")
 
 done:
     FUNC_LEAVE_API(ret_value)
-} /* H5Pget_file_space() */
+} /* H5Pget_file_space_strategy() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:       H5P__fcrt_fspace_strategy_enc
+ *
+ * Purpose:        Callback routine which is called whenever the free-space
+ *                 strategy property in the file creation property list
+ *                 is encoded.
+ *
+ * Return:	   Success:	Non-negative
+ *		   Failure:	Negative
+ *
+ * Programmer:     Quincey Koziol
+ *                 Friday, December 27, 2013
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5P__fcrt_fspace_strategy_enc(const void *value, void **_pp, size_t *size)
+{
+    const H5F_fspace_strategy_t *strategy = (const H5F_fspace_strategy_t *)value; /* Create local alias for values */
+    uint8_t **pp = (uint8_t **)_pp;
+
+    FUNC_ENTER_STATIC_NOERR
+
+    /* Sanity check */
+    HDassert(strategy);
+    HDassert(size);
+
+    if(NULL != *pp)
+        /* Encode free-space strategy */
+        *(*pp)++ = (uint8_t)*strategy;
+
+    /* Size of free-space strategy */
+    (*size)++;
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5P__fcrt_fspace_strategy_enc() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:       H5P__fcrt_fspace_strategy_dec
+ *
+ * Purpose:        Callback routine which is called whenever the free-space
+ *                 strategy property in the file creation property list
+ *                 is decoded.
+ *
+ * Return:	   Success:	Non-negative
+ *		   Failure:	Negative
+ *
+ * Programmer:     Quincey Koziol
+ *                 Friday, December 27, 2013
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5P__fcrt_fspace_strategy_dec(const void **_pp, void *_value)
+{
+    H5F_fspace_strategy_t *strategy = (H5F_fspace_strategy_t *)_value;         /* Free-space strategy */
+    const uint8_t **pp = (const uint8_t **)_pp;
+
+    FUNC_ENTER_STATIC_NOERR
+
+    /* Sanity checks */
+    HDassert(pp);
+    HDassert(*pp);
+    HDassert(strategy);
+
+    /* Decode free-space strategy */
+    *strategy = (H5F_fspace_strategy_t)*(*pp)++;
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5P__fcrt_fspace_strategy_dec() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5Pset_file_space_page_size
+ *
+ * Purpose:     Sets the file space page size for paged aggregation.
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Vailin Choi; August 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Pset_file_space_page_size(hid_t plist_id, hsize_t fsp_size)
+{
+    H5P_genplist_t *plist;              /* Property list pointer */
+    herr_t      ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE2("e", "ih", plist_id, fsp_size);
+
+    /* Get the plist structure */
+    if(NULL == (plist = H5P_object_verify(plist_id,H5P_FILE_CREATE)))
+        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't find object for ID")
+
+    if(fsp_size < H5F_FILE_SPACE_PAGE_SIZE_MIN)
+        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "cannot set file space page size to less than 512")
+
+    /* Set the value*/
+    if(H5P_set(plist, H5F_CRT_FILE_SPACE_PAGE_SIZE_NAME, &fsp_size) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't set file space page size")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* H5Pset_file_space_page_size() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5Pget_file_space_page_size
+ *
+ * Purpose:     Retrieves the file space page size for aggregating small metadata
+ *		or raw data in the parameter "fsp_size".
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Vailin Choi; August 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Pget_file_space_page_size(hid_t plist_id, hsize_t *fsp_size)
+{
+    H5P_genplist_t *plist;              /* Property list pointer */
+    herr_t      ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE2("e", "i*h", plist_id, fsp_size);
+
+    /* Get the plist structure */
+    if(NULL == (plist = H5P_object_verify(plist_id,H5P_FILE_CREATE)))
+        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't find object for ID")
+
+    /* Get value */
+    if(fsp_size)
+        if(H5P_get(plist, H5F_CRT_FILE_SPACE_PAGE_SIZE_NAME, fsp_size) < 0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get file space page size")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* H5Pget_file_space_page_size() */
 
diff --git a/src/H5Ppublic.h b/src/H5Ppublic.h
index 5aa8301..50b9eb0 100644
--- a/src/H5Ppublic.h
+++ b/src/H5Ppublic.h
@@ -300,8 +300,10 @@ H5_DLL herr_t H5Pset_shared_mesg_index(hid_t plist_id, unsigned index_num, unsig
 H5_DLL herr_t H5Pget_shared_mesg_index(hid_t plist_id, unsigned index_num, unsigned *mesg_type_flags, unsigned *min_mesg_size);
 H5_DLL herr_t H5Pset_shared_mesg_phase_change(hid_t plist_id, unsigned max_list, unsigned min_btree);
 H5_DLL herr_t H5Pget_shared_mesg_phase_change(hid_t plist_id, unsigned *max_list, unsigned *min_btree);
-H5_DLL herr_t H5Pset_file_space(hid_t plist_id, H5F_file_space_type_t strategy, hsize_t threshold);
-H5_DLL herr_t H5Pget_file_space(hid_t plist_id, H5F_file_space_type_t *strategy, hsize_t *threshold);
+H5_DLL herr_t H5Pset_file_space_strategy(hid_t plist_id, H5F_fspace_strategy_t strategy, hbool_t persist, hsize_t threshold);
+H5_DLL herr_t H5Pget_file_space_strategy(hid_t plist_id, H5F_fspace_strategy_t *strategy, hbool_t *persist, hsize_t *threshold);
+H5_DLL herr_t H5Pset_file_space_page_size(hid_t plist_id, hsize_t fsp_size);
+H5_DLL herr_t H5Pget_file_space_page_size(hid_t plist_id, hsize_t *fsp_size);
 
 /* File access property list (FAPL) routines */
 H5_DLL herr_t H5Pset_alignment(hid_t fapl_id, hsize_t threshold,
@@ -367,6 +369,8 @@ H5_DLL herr_t H5Pget_coll_metadata_write(hid_t plist_id, hbool_t *is_collective)
 #endif /* H5_HAVE_PARALLEL */
 H5_DLL herr_t H5Pset_mdc_image_config(hid_t plist_id, H5AC_cache_image_config_t *config_ptr);
 H5_DLL herr_t H5Pget_mdc_image_config(hid_t plist_id, H5AC_cache_image_config_t *config_ptr /*out*/);
+H5_DLL herr_t H5Pset_page_buffer_size(hid_t plist_id, size_t buf_size, unsigned min_meta_per, unsigned min_raw_per);
+H5_DLL herr_t H5Pget_page_buffer_size(hid_t plist_id, size_t *buf_size, unsigned *min_meta_per, unsigned *min_raw_per);
 
 /* Dataset creation property list (DCPL) routines */
 H5_DLL herr_t H5Pset_layout(hid_t plist_id, H5D_layout_t layout);
@@ -534,6 +538,8 @@ H5_DLL herr_t H5Pget_filter_by_id1(hid_t plist_id, H5Z_filter_t id,
 H5_DLL herr_t H5Pget_version(hid_t plist_id, unsigned *boot/*out*/,
          unsigned *freelist/*out*/, unsigned *stab/*out*/,
          unsigned *shhdr/*out*/);
+H5_DLL herr_t H5Pset_file_space(hid_t plist_id, H5F_file_space_type_t strategy, hsize_t threshold);
+H5_DLL herr_t H5Pget_file_space(hid_t plist_id, H5F_file_space_type_t *strategy, hsize_t *threshold);
 #endif /* H5_NO_DEPRECATED_SYMBOLS */
 
 #ifdef __cplusplus
diff --git a/src/H5Z.c b/src/H5Z.c
index e7a2186..0be0bbe 100644
--- a/src/H5Z.c
+++ b/src/H5Z.c
@@ -626,7 +626,7 @@ H5Z__flush_file_cb(void *obj_ptr, hid_t H5_ATTR_UNUSED obj_id, void H5_ATTR_UNUS
     /* Call the flush routine for mounted file hierarchies. Do a global flush 
      * if the file is opened for write */
     if(H5F_ACC_RDWR & H5F_INTENT((H5F_t *)obj_ptr)) {
-        if(H5F_flush_mounts((H5F_t *)obj_ptr, H5AC_ind_read_dxpl_id) < 0)
+        if(H5F_flush_mounts((H5F_t *)obj_ptr, H5AC_ind_read_dxpl_id, H5AC_rawdata_dxpl_id) < 0)
             HGOTO_ERROR(H5E_PLINE, H5E_CANTFLUSH, FAIL, "unable to flush file hierarchy")
     } /* end if */
 
diff --git a/src/H5err.txt b/src/H5err.txt
index 48069a5..b2ff3bd 100644
--- a/src/H5err.txt
+++ b/src/H5err.txt
@@ -77,6 +77,7 @@ MAJOR, H5E_SOHM, Shared Object Header Messages
 MAJOR, H5E_EARRAY, Extensible Array
 MAJOR, H5E_FARRAY, Fixed Array
 MAJOR, H5E_PLUGIN, Plugin for dynamically loaded library
+MAJOR, H5E_PAGEBUF, Page Buffering
 MAJOR, H5E_NONE_MAJOR, No error
 
 # Sections (for grouping minor errors)
diff --git a/src/H5private.h b/src/H5private.h
index 00de96c..61ecc5b 100644
--- a/src/H5private.h
+++ b/src/H5private.h
@@ -1386,7 +1386,13 @@ typedef off_t               h5_stat_size_t;
 #ifndef HDstrtol
     #define HDstrtol(S,R,N)    strtol(S,R,N)
 #endif /* HDstrtol */
-H5_DLL int64_t HDstrtoll (const char *s, const char **rest, int base);
+#ifndef HDstrtoll
+    #ifdef H5_HAVE_STRTOLL
+        #define HDstrtoll(S,R,N)  strtoll(S,R,N)
+    #else
+        H5_DLL int64_t HDstrtoll (const char *s, const char **rest, int base);
+    #endif /* H5_HAVE_STRTOLL */
+#endif /* HDstrtoll */
 #ifndef HDstrtoul
     #define HDstrtoul(S,R,N)  strtoul(S,R,N)
 #endif /* HDstrtoul */
diff --git a/src/H5system.c b/src/H5system.c
index ac323c0..1f92e19 100644
--- a/src/H5system.c
+++ b/src/H5system.c
@@ -32,10 +32,10 @@
 /***********/
 /* Headers */
 /***********/
-#include "H5private.h"		/* Generic Functions			*/
-#include "H5Eprivate.h"		/* Error handling		  	*/
-#include "H5Fprivate.h"		/* File access				*/
-#include "H5MMprivate.h"	/* Memory management			*/
+#include "H5private.h"        /* Generic Functions            */
+#include "H5Eprivate.h"        /* Error handling              */
+#include "H5Fprivate.h"        /* File access                */
+#include "H5MMprivate.h"    /* Memory management            */
 
 
 /****************/
@@ -474,6 +474,7 @@ HDfprintf(FILE *stream, const char *fmt, ...)
  *
  *-------------------------------------------------------------------------
  */
+#ifndef HDstrtoll
 int64_t
 HDstrtoll(const char *s, const char **rest, int base)
 {
@@ -549,7 +550,7 @@ HDstrtoll(const char *s, const char **rest, int base)
         *rest = s;
     return acc;
 } /* end HDstrtoll() */
-
+#endif
 
 /*-------------------------------------------------------------------------
  * Function:  HDrand/HDsrand
@@ -604,7 +605,7 @@ void HDsrand(unsigned int seed)
 #ifdef H5_HAVE_FCNTL
 int
 Pflock(int fd, int operation) {
-    
+
     struct flock    flk;
 
     /* Set the lock type */
@@ -649,18 +650,18 @@ Nflock(int H5_ATTR_UNUSED fd, int H5_ATTR_UNUSED operation) {
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5_make_time
+ * Function:    H5_make_time
  *
- * Purpose:	Portability routine to abstract converting a 'tm' struct into
- *		a time_t value.
+ * Purpose:    Portability routine to abstract converting a 'tm' struct into
+ *        a time_t value.
  *
- * Note:	This is a little problematic because mktime() operates on
- *		local times.  We convert to local time and then figure out the
- *		adjustment based on the local time zone and daylight savings
- *		setting.
+ * Note:    This is a little problematic because mktime() operates on
+ *        local times.  We convert to local time and then figure out the
+ *        adjustment based on the local time zone and daylight savings
+ *        setting.
  *
- * Return:	Success:  The value of timezone
- *		Failure:  -1
+ * Return:    Success:  The value of timezone
+ *        Failure:  -1
  *
  * Programmer:  Quincey Koziol
  *              November 18, 2015
@@ -1138,7 +1139,7 @@ H5_combine_path(const char* path1, const char* path2, char **full_name /*out*/)
         if(NULL == (*full_name = (char *)H5MM_strdup(path2)))
             HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed")
 
-    } /* end if */ 
+    } /* end if */
     else if(H5_CHECK_ABS_PATH(path2)) {
 
         /* On windows path2 is a path absolute name */
diff --git a/src/H5trace.c b/src/H5trace.c
index 44b2ed5..48c357a 100644
--- a/src/H5trace.c
+++ b/src/H5trace.c
@@ -895,32 +895,28 @@ H5_trace(const double *returning, const char *func, const char *type, ...)
                                 fprintf(out, "NULL");
                         } /* end if */
                         else {
-                            H5F_file_space_type_t fs_type = (H5F_file_space_type_t)va_arg(ap, int);
+                            H5F_fspace_strategy_t fs_strategy = (H5F_fspace_strategy_t)va_arg(ap, int);
 
-                            switch(fs_type) {
-                                case H5F_FILE_SPACE_DEFAULT:
-                                    fprintf(out, "H5F_FILE_SPACE_DEFAULT");
+                            switch(fs_strategy) {
+                                case H5F_FSPACE_STRATEGY_FSM_AGGR:
+                                    fprintf(out, "H5F_FSPACE_STRATEGY_FSM_AGGR");
                                     break;
 
-                                case H5F_FILE_SPACE_ALL_PERSIST:
-                                    fprintf(out, "H5F_FILE_SPACE_ALL_PERSIST");
+                                case H5F_FSPACE_STRATEGY_PAGE:
+                                    fprintf(out, "H5F_FSPACE_STRATEGY_PAGE");
                                     break;
 
-                                case H5F_FILE_SPACE_ALL:
-                                    fprintf(out, "H5F_FILE_SPACE_ALL");
+                                case H5F_FSPACE_STRATEGY_AGGR:
+                                    fprintf(out, "H5F_FSPACE_STRATEGY_AGGR");
                                     break;
 
-                                case H5F_FILE_SPACE_AGGR_VFD:
-                                    fprintf(out, "H5F_FILE_SPACE_AGGR_VFD");
+                                case H5F_FSPACE_STRATEGY_NONE:
+                                    fprintf(out, "H5F_FSPACE_STRATEGY_NONE");
                                     break;
 
-                                case H5F_FILE_SPACE_VFD:
-                                    fprintf(out, "H5F_FILE_SPACE_VFD");
-                                    break;
-
-                                case H5F_FILE_SPACE_NTYPES:
+                                case H5F_FSPACE_STRATEGY_NTYPES:
                                 default:
-                                    fprintf(out, "%ld", (long)fs_type);
+                                    fprintf(out, "%ld", (long)fs_strategy);
                                     break;
                             } /* end switch */
                         } /* end else */
@@ -1003,6 +999,15 @@ H5_trace(const double *returning, const char *func, const char *type, ...)
                         } /* end else */
                         break;
 
+                    case 't':
+                        if(ptr) {
+                            if(vp)
+                                fprintf(out, "0x%lx", (unsigned long)vp);
+                            else
+                                fprintf(out, "NULL");
+                        } /* end if */
+                        break;
+
                     case 'v':
                         if(ptr) {
                             if(vp)
diff --git a/src/H5win32defs.h b/src/H5win32defs.h
index b419f06..e005b51 100644
--- a/src/H5win32defs.h
+++ b/src/H5win32defs.h
@@ -23,6 +23,11 @@
  *
  */
 
+/*
+ * _MSC_VER = 1900 VS2015
+ * _MSC_VER = 1800 VS2013
+ * _MSC_VER = 1700 VS2012
+ */
 #ifdef H5_HAVE_WIN32_API
 
 typedef struct _stati64     h5_stat_t;
@@ -54,13 +59,22 @@ typedef __int64             h5_stat_size_t;
 #define HDsleep(S)          Sleep(S*1000)
 #define HDstat(S,B)         _stati64(S,B)
 #define HDstrcasecmp(A,B)   _stricmp(A,B)
-#define HDstrtoull(S,R,N)   _strtoui64(S,R,N)
 #define HDstrdup(S)         _strdup(S)
 #define HDtzset()           _tzset()
 #define HDunlink(S)         _unlink(S)
 #define HDwrite(F,M,Z)      _write(F,M,Z)
 
 #ifdef H5_HAVE_VISUAL_STUDIO
+
+#if (_MSC_VER < 1800)
+  #ifndef H5_HAVE_STRTOLL
+    #define HDstrtoll(S,R,N)    _strtoi64(S,R,N)
+  #endif /* H5_HAVE_STRTOLL */
+  #ifndef H5_HAVE_STRTOULL
+    #define HDstrtoull(S,R,N)   _strtoui64(S,R,N)
+  #endif /* H5_HAVE_STRTOULL */
+#endif /* MSC_VER < 1800 */
+
 /*
  * The (void*) cast just avoids a compiler warning in H5_HAVE_VISUAL_STUDIO
  */
diff --git a/src/Makefile.am b/src/Makefile.am
index 69b54b4..59df4c2 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -60,7 +60,7 @@ libhdf5_la_SOURCES= H5.c H5checksum.c H5dbg.c H5system.c H5timer.c H5trace.c \
         H5F.c H5Fint.c H5Faccum.c H5Fcwfs.c \
         H5Fdbg.c H5Fdeprec.c H5Fefc.c H5Ffake.c H5Fio.c \
         H5Fmount.c H5Fquery.c \
-        H5Fsfile.c H5Fsuper.c H5Fsuper_cache.c H5Ftest.c \
+        H5Fsfile.c H5Fspace.c H5Fsuper.c H5Fsuper_cache.c H5Ftest.c \
         H5FA.c H5FAcache.c H5FAdbg.c H5FAdblock.c H5FAdblkpage.c H5FAhdr.c \
         H5FAint.c H5FAstat.c H5FAtest.c \
         H5FD.c H5FDcore.c  \
@@ -98,6 +98,7 @@ libhdf5_la_SOURCES= H5.c H5checksum.c H5dbg.c H5system.c H5timer.c H5trace.c \
         H5Pfapl.c H5Pfcpl.c H5Pfmpl.c \
         H5Pgcpl.c H5Pint.c \
         H5Plapl.c H5Plcpl.c H5Pocpl.c H5Pocpypl.c H5Pstrcpl.c H5Ptest.c \
+        H5PB.c \
         H5PL.c \
         H5R.c H5Rdeprec.c \
         H5UC.c \