[svn-r12093] Purpose:

    Code checkpoint

Description:
    Checkpoint fractal heap changes - mostly internal changes to better
handle more direct blocks from root indirect block.

Platforms tested:
    FreeBSD 4.11 (sleipnir)
    Linux 2.4 (chicago)
    Mac OS X (amazon)

14 files changed, 903 insertions, 211 deletions

diff --git a/src/H5B2.c b/src/H5B2.c
index 57ba36c..98dca71 100644
--- a/src/H5B2.c
+++ b/src/H5B2.c
@@ -53,6 +53,11 @@
 
 
 /********************/
+/* Package Typedefs */
+/********************/
+
+
+/********************/
 /* Local Prototypes */
 /********************/
 
diff --git a/src/H5B2cache.c b/src/H5B2cache.c
index 062f56c..476e9d1 100644
--- a/src/H5B2cache.c
+++ b/src/H5B2cache.c
@@ -50,6 +50,12 @@
 /* Local Typedefs */
 /******************/
 
+
+/********************/
+/* Package Typedefs */
+/********************/
+
+
 /********************/
 /* Local Prototypes */
 /********************/
diff --git a/src/H5B2dbg.c b/src/H5B2dbg.c
index 6e51fbc..0bc8cd9 100644
--- a/src/H5B2dbg.c
+++ b/src/H5B2dbg.c
@@ -48,6 +48,11 @@
 
 
 /********************/
+/* Package Typedefs */
+/********************/
+
+
+/********************/
 /* Local Prototypes */
 /********************/
 
diff --git a/src/H5B2int.c b/src/H5B2int.c
index 9b4b8db..1d35cbd 100644
--- a/src/H5B2int.c
+++ b/src/H5B2int.c
@@ -57,6 +57,12 @@
 /* Local Typedefs */
 /******************/
 
+
+/********************/
+/* Package Typedefs */
+/********************/
+
+
 /********************/
 /* Local Prototypes */
 /********************/
diff --git a/src/H5B2stat.c b/src/H5B2stat.c
index a8f8c54..cd0881c 100644
--- a/src/H5B2stat.c
+++ b/src/H5B2stat.c
@@ -43,6 +43,11 @@
 
 
 /********************/
+/* Package Typedefs */
+/********************/
+
+
+/********************/
 /* Local Prototypes */
 /********************/
 
diff --git a/src/H5B2test.c b/src/H5B2test.c
index 7749ee7..3d3f787 100644
--- a/src/H5B2test.c
+++ b/src/H5B2test.c
@@ -44,6 +44,11 @@
 
 
 /********************/
+/* Package Typedefs */
+/********************/
+
+
+/********************/
 /* Local Prototypes */
 /********************/
 static herr_t H5B2_test_store(void *nrecord, const void *udata);
diff --git a/src/H5HF.c b/src/H5HF.c
index f183748..d5649d8 100644
--- a/src/H5HF.c
+++ b/src/H5HF.c
@@ -53,6 +53,11 @@
 
 
 /********************/
+/* Package Typedefs */
+/********************/
+
+
+/********************/
 /* Local Prototypes */
 /********************/
 
diff --git a/src/H5HFcache.c b/src/H5HFcache.c
index 348f9eb..2b34604 100644
--- a/src/H5HFcache.c
+++ b/src/H5HFcache.c
@@ -51,6 +51,12 @@
 /* Local Typedefs */
 /******************/
 
+
+/********************/
+/* Package Typedefs */
+/********************/
+
+
 /********************/
 /* Local Prototypes */
 /********************/
@@ -177,12 +183,6 @@ H5HF_dtable_decode(H5F_t *f, const uint8_t **pp, H5HF_dtable_t *dtable)
     /* Next direct block's heap offset */
     H5F_DECODE_LENGTH(f, *pp, dtable->next_dir_block);
 
-    /* Next direct block size */
-    H5F_DECODE_LENGTH(f, *pp, dtable->next_dir_size);
-
-    /* Next direct block column */
-    UINT16DECODE(*pp, dtable->next_dir_col);
-
     FUNC_LEAVE_NOAPI(SUCCEED)
 } /* end H5HF_dtable_decode() */
 
@@ -236,12 +236,6 @@ H5HF_dtable_encode(H5F_t *f, uint8_t **pp, const H5HF_dtable_t *dtable)
     /* Next direct block's heap offset */
     H5F_ENCODE_LENGTH(f, *pp, dtable->next_dir_block);
 
-    /* Next direct block size */
-    H5F_ENCODE_LENGTH(f, *pp, dtable->next_dir_size);
-
-    /* Next direct block column */
-    UINT16ENCODE(*pp, dtable->next_dir_col);
-
     FUNC_LEAVE_NOAPI(SUCCEED)
 } /* end H5HF_dtable_encode() */
 
@@ -591,10 +585,10 @@ H5HF_cache_hdr_size(const H5F_t *f, const H5HF_t UNUSED *fh, size_t *size_ptr)
  *-------------------------------------------------------------------------
  */
 static H5HF_direct_t *
-H5HF_cache_dblock_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void *_size, void *_fh_shared)
+H5HF_cache_dblock_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void *_size, void *_par_shared)
 {
     const size_t        *size = (const size_t *)_size;         /* Size of block */
-    H5RC_t 		*fh_shared = (H5RC_t *)_fh_shared;     /* Shared heap information */
+    H5HF_parent_shared_t *par_shared = (H5HF_parent_shared_t *)_par_shared;     /* Shared direct block information */
     H5HF_shared_t       *shared = NULL; /* Shared fractal heap information */
     H5HF_direct_t	*dblock = NULL; /* Direct block info */
     const uint8_t	*p;             /* Pointer into raw data buffer */
@@ -607,7 +601,7 @@ H5HF_cache_dblock_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void *_size,
     /* Check arguments */
     HDassert(f);
     HDassert(H5F_addr_defined(addr));
-    HDassert(fh_shared);
+    HDassert(par_shared);
 
     /* Allocate space for the fractal heap direct block */
     if(NULL == (dblock = H5FL_MALLOC(H5HF_direct_t)))
@@ -615,13 +609,20 @@ H5HF_cache_dblock_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void *_size,
     HDmemset(&dblock->cache_info, 0, sizeof(H5AC_info_t));
 
     /* Share common heap information */
-    dblock->shared = fh_shared;
+    dblock->shared = par_shared->shared;
     H5RC_INC(dblock->shared);
 
     /* Get the pointer to the shared heap info */
     shared = H5RC_GET_OBJ(dblock->shared);
     HDassert(shared);
 
+    /* Share common parent [indirect] block information */
+    dblock->parent = par_shared->parent;
+    if(dblock->parent)
+        H5RC_INC(dblock->parent);
+    dblock->parent_entry = par_shared->parent_entry;
+    dblock->blk_free_space = (size_t)par_shared->parent_free_space;
+
     /* Set block's internal information */
     dblock->size = *size;
     dblock->blk_off_size = H5HF_SIZEOF_OFFSET_LEN(dblock->size);
@@ -666,9 +667,6 @@ H5HF_cache_dblock_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void *_size,
     /* Offset of heap within the heap's address space */
     UINT64DECODE_VAR(p, dblock->block_off, shared->heap_off_size);
 
-    /* Total free space in block */
-    UINT64DECODE_VAR(p, dblock->blk_free_space, dblock->blk_off_size);
-
     /* Offset of free list head */
     /* (Defer deserializing the whole free list until we actually need to modify it) */
     UINT64DECODE_VAR(p, dblock->free_list_head, dblock->blk_off_size);
@@ -745,9 +743,6 @@ H5HF_cache_dblock_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t addr,
         if(shared->addrmap != H5HF_ABSOLUTE)
             HGOTO_ERROR(H5E_HEAP, H5E_UNSUPPORTED, FAIL, "encoding mapped direct blocks not supported currently")
 
-        /* Total free space in block */
-        UINT64ENCODE_VAR(p, dblock->blk_free_space, dblock->blk_off_size);
-
         /* Offset of free list head */
         UINT64ENCODE_VAR(p, dblock->free_list_head, dblock->blk_off_size);
 
@@ -832,6 +827,8 @@ H5HF_cache_dblock_dest(H5F_t UNUSED *f, H5HF_direct_t *dblock)
     /* Decrement reference count on shared fractal heap info */
     if(dblock->shared)
         H5RC_DEC(dblock->shared);
+    if(dblock->parent)
+        H5RC_DEC(dblock->parent);
 
     /* Check for free list & free it, if necessary */
     if(dblock->free_list) {
@@ -951,10 +948,10 @@ H5HF_cache_dblock_size(const H5F_t UNUSED *f, const H5HF_direct_t *dblock, size_
  *-------------------------------------------------------------------------
  */
 static H5HF_indirect_t *
-H5HF_cache_iblock_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void *_nrows, void *_fh_shared)
+H5HF_cache_iblock_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void *_nrows, void *_par_shared)
 {
     const unsigned      *nrows = (const unsigned *)_nrows;     /* # of rows in indirect block */
-    H5RC_t 		*fh_shared = (H5RC_t *)_fh_shared;     /* Shared heap information */
+    H5HF_parent_shared_t *par_shared = (H5HF_parent_shared_t *)_par_shared;     /* Shared direct block information */
     H5HF_shared_t       *shared = NULL; /* Shared fractal heap information */
     H5HF_indirect_t	*iblock = NULL; /* Indirect block info */
     uint8_t		*buf = NULL;    /* Temporary buffer */
@@ -969,7 +966,7 @@ H5HF_cache_iblock_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void *_nrows
     /* Check arguments */
     HDassert(f);
     HDassert(H5F_addr_defined(addr));
-    HDassert(fh_shared);
+    HDassert(par_shared);
 
     /* Allocate space for the fractal heap indirect block */
     if(NULL == (iblock = H5FL_MALLOC(H5HF_indirect_t)))
@@ -977,13 +974,24 @@ H5HF_cache_iblock_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void *_nrows
     HDmemset(&iblock->cache_info, 0, sizeof(H5AC_info_t));
 
     /* Share common heap information */
-    iblock->shared = fh_shared;
+    iblock->shared = par_shared->shared;
     H5RC_INC(iblock->shared);
 
     /* Get the pointer to the shared heap info */
     shared = H5RC_GET_OBJ(iblock->shared);
     HDassert(shared);
 
+    /* Share common parent [indirect] block information */
+    iblock->parent = par_shared->parent;
+    if(iblock->parent)
+        H5RC_INC(iblock->parent);
+    iblock->parent_entry = par_shared->parent_entry;
+    iblock->child_free_space = par_shared->parent_free_space;
+
+    /* Make a reference to this block */
+    if(NULL == (iblock->self = H5RC_create(iblock, H5HF_iblock_free)))
+	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "can't create ref-count wrapper for indirect fractal heap block")
+
     /* Set block's internal information */
     iblock->nrows = *nrows;
     if(iblock->nrows > shared->man_dtable.max_direct_rows) {
@@ -1041,17 +1049,40 @@ H5HF_cache_iblock_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, const void *_nrows
     HDassert(iblock->ndir_rows > 0);
     if(NULL == (iblock->dblock_ents = H5FL_SEQ_MALLOC(H5HF_indirect_dblock_ent_t, (iblock->ndir_rows * shared->man_dtable.cparam.width))))
 	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed for direct entries")
+    iblock->dir_full = TRUE;
     for(u = 0; u < (iblock->ndir_rows * shared->man_dtable.cparam.width); u++) {
         H5F_addr_decode(f, &p, &(iblock->dblock_ents[u].addr));
         UINT32DECODE_VAR(p, iblock->dblock_ents[u].free_space, shared->man_dtable.max_dir_blk_off_size);
+
+        /* Check for direct block being undefined and use that for the next one to allocate from this indirect block */
+        if(iblock->dir_full) {
+            if(!H5F_addr_defined(iblock->dblock_ents[u].addr)) {
+                iblock->next_dir_col = u % shared->man_dtable.cparam.width;
+                iblock->next_dir_row = u / shared->man_dtable.cparam.width;
+                iblock->next_dir_entry = u;
+                if(iblock->next_dir_row == 0)
+                    iblock->next_dir_size = shared->man_dtable.cparam.start_block_size;
+                else
+                    iblock->next_dir_size = shared->man_dtable.cparam.start_block_size * (1 << (iblock->next_dir_row - 1));
+                if(heap_addr == 0)
+                    iblock->max_direct_rows = shared->man_dtable.max_direct_rows;
+                else
+                    HGOTO_ERROR(H5E_HEAP, H5E_UNSUPPORTED, NULL, "computing max direct rows for non-root indirect block not supported yet")
+
+                /* Set the flag to indicate the direct blocks aren't full */
+                iblock->dir_full = FALSE;
+            } /* end if */
+        } /* end if */
     } /* end for */
     if(iblock->nindir_rows > 0) {
         if(NULL == (iblock->iblock_ents = H5FL_SEQ_MALLOC(H5HF_indirect_iblock_ent_t, (iblock->nindir_rows * shared->man_dtable.cparam.width))))
             HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed for indirect entries")
 
         /* Decode indirect block-specific fields */
-        for(u = 0; u < (iblock->nindir_rows * shared->man_dtable.cparam.width); u++)
+        for(u = 0; u < (iblock->nindir_rows * shared->man_dtable.cparam.width); u++) {
             H5F_addr_decode(f, &p, &(iblock->iblock_ents[u].addr));
+            UINT64DECODE_VAR(p, iblock->iblock_ents[u].free_space, shared->heap_off_size);
+        } /* end for */
     } /* end if */
     else
         iblock->iblock_ents = NULL;
@@ -1105,6 +1136,12 @@ H5HF_cache_iblock_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t addr,
         uint8_t *p;                 /* Pointer into raw data buffer */
         size_t u;                   /* Local index variable */
 
+        /* Sanity check */
+        HDassert(iblock->dirty);
+#ifdef QAK
+HDfprintf(stderr, "%s: Flushing indirect block\n", FUNC);
+#endif /* QAK */
+
         /* Get the pointer to the shared heap info */
         shared = H5RC_GET_OBJ(iblock->shared);
         HDassert(shared);
@@ -1145,6 +1182,9 @@ HDfprintf(stderr, "%s: shared->man_dtable.cparam.width = %u\n", FUNC, shared->ma
 
         /* Offset of block in heap */
         UINT64ENCODE_VAR(p, iblock->block_off, shared->heap_off_size);
+/* XXX: Fix this when we start writing recursive indirect blocks */
+if(iblock->block_off != 0)
+    HGOTO_ERROR(H5E_HEAP, H5E_UNSUPPORTED, FAIL, "fix computing max direct rows for non-root indirect block for loading")
 
         /* Encode indirect block-specific fields */
         HDassert(iblock->ndir_rows > 0);
@@ -1153,8 +1193,10 @@ HDfprintf(stderr, "%s: shared->man_dtable.cparam.width = %u\n", FUNC, shared->ma
             UINT32ENCODE_VAR(p, iblock->dblock_ents[u].free_space, shared->man_dtable.max_dir_blk_off_size);
         } /* end for */
         if(iblock->nindir_rows > 0)
-            for(u = 0; u < (iblock->nindir_rows * shared->man_dtable.cparam.width); u++)
+            for(u = 0; u < (iblock->nindir_rows * shared->man_dtable.cparam.width); u++) {
                 H5F_addr_encode(f, &p, iblock->iblock_ents[u].addr);
+                UINT64ENCODE_VAR(p, iblock->iblock_ents[u].free_space, shared->heap_off_size);
+            } /* end for */
 
         /* Sanity check */
         HDassert((size_t)(p - buf) == iblock->size);
@@ -1201,19 +1243,26 @@ H5HF_cache_iblock_dest(H5F_t UNUSED *f, H5HF_indirect_t *iblock)
      * Check arguments.
      */
     HDassert(iblock);
+#ifdef QAK
+HDfprintf(stderr, "%s: Destroying indirect block\n", "H5HF_cache_iblock_dest");
+#endif /* QAK */
 
-    /* Decrement reference count on shared fractal heap info */
-    if(iblock->shared)
-        H5RC_DEC(iblock->shared);
-
-    /* Release entry tables */
-    if(iblock->dblock_ents)
-        H5FL_SEQ_FREE(H5HF_indirect_dblock_ent_t, iblock->dblock_ents);
-    if(iblock->iblock_ents)
-        H5FL_SEQ_FREE(H5HF_indirect_iblock_ent_t, iblock->iblock_ents);
-
-    /* Free fractal heap indirect block info */
-    H5FL_FREE(H5HF_indirect_t, iblock);
+    /* Decrement reference count on self */
+    /* (let ref-counting API's callback for the block perform all cleanup) */
+/* XXX: This should actually free all the indirect block info, since this
+ *      routine should not get called until the block has no dependents (once
+ *      the "un-evictable" flag is in the metadata cache)
+ */
+/* XXX: Once the "un-evictable" flag is working in the metadata cache, can
+ *      get rid of the "self" field and make a wrapper when creating the parent
+ *      info for each "child" block, which will make the indirect block 
+ *      un-evictable as well as create the initial ref-counted object.
+ */
+/* XXX: Once the "un-evictable" flag is working in the metadata cache, the
+ *      ref-counted 'free' callback should just make the indirect block
+ *      evictable again.
+ */
+    H5RC_DEC(iblock->self);
 
     FUNC_LEAVE_NOAPI(SUCCEED)
 } /* end H5HF_cache_iblock_dest() */
diff --git a/src/H5HFdbg.c b/src/H5HFdbg.c
index 977f40f..5dddac7 100644
--- a/src/H5HFdbg.c
+++ b/src/H5HFdbg.c
@@ -49,6 +49,11 @@
 
 
 /********************/
+/* Package Typedefs */
+/********************/
+
+
+/********************/
 /* Local Prototypes */
 /********************/
 
@@ -124,12 +129,6 @@ H5HF_dtable_debug(H5HF_dtable_t *dtable, FILE *stream, int indent, int fwidth)
     HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
 	      "Current # of rows in root indirect block:",
 	      dtable->curr_root_rows);
-    HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
-	      "Next direct block size:",
-	      dtable->next_dir_size);
-    HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
-	      "Next direct block column:",
-	      dtable->next_dir_col);
 
     /* Computed values */
     HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
@@ -257,6 +256,7 @@ H5HF_dblock_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE *stream,
 {
     H5HF_t	*fh = NULL;             /* Fractal heap header info */
     H5HF_direct_t *dblock = NULL;       /* Fractal heap direct block info */
+    H5HF_parent_shared_t par_shared;    /* Parent shared information */
     H5HF_direct_free_node_t *node;      /* Pointer to free list node for block */
     H5HF_shared_t *shared;              /* Shared fractal heap information */
     size_t	blk_prefix_size;        /* Size of prefix for block */
@@ -293,9 +293,19 @@ H5HF_dblock_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE *stream,
     /*
      * Load the heap direct block
      */
-    if(NULL == (dblock = H5AC_protect(f, dxpl_id, H5AC_FHEAP_DBLOCK, addr, &block_size, fh->shared, H5AC_READ)))
+    par_shared.shared = fh->shared;
+    par_shared.parent = NULL;
+    par_shared.parent_entry = 0;
+    par_shared.parent_free_space = 0;
+    if(NULL == (dblock = H5AC_protect(f, dxpl_id, H5AC_FHEAP_DBLOCK, addr, &block_size, &par_shared, H5AC_READ)))
 	HGOTO_ERROR(H5E_HEAP, H5E_CANTLOAD, FAIL, "unable to load fractal heap direct block")
 
+    /* Check for valid free list */
+    if(!dblock->free_list)
+        if(H5HF_man_dblock_build_freelist(dblock, addr) < 0)
+            HGOTO_ERROR(H5E_HEAP, H5E_CANTDECODE, FAIL, "can't decode free list for block")
+    HDassert(dblock->free_list);
+
     /* Release the heap header */
     if(H5AC_unprotect(f, dxpl_id, H5AC_FHEAP_HDR, hdr_addr, fh, H5AC__NO_FLAGS_SET) < 0)
         HDONE_ERROR(H5E_HEAP, H5E_PROTECT, FAIL, "unable to release fractal heap header")
@@ -327,12 +337,6 @@ H5HF_dblock_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE *stream,
 	      "Offset of free list head:",
 	      dblock->free_list_head);
 
-    /* Check for valid free list */
-    if(!dblock->free_list)
-        if(H5HF_man_dblock_build_freelist(dblock, addr) < 0)
-            HGOTO_ERROR(H5E_HEAP, H5E_CANTDECODE, FAIL, "can't decode free list for block")
-    HDassert(dblock->free_list);
-
     /*
      * Traverse the free list and check that all free blocks fall within
      * the block and that no two free blocks point to the same region of
@@ -340,8 +344,9 @@ H5HF_dblock_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE *stream,
     if(NULL == (marker = H5MM_calloc(dblock->size)))
 	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed")
 
-    HDfprintf(stream, "%*sFree Blocks (offset, next offset, size):\n", indent, "");
     node = dblock->free_list->first;
+    if(node)
+        HDfprintf(stream, "%*sFree Blocks (offset, next offset, size):\n", indent, "");
     while(node) {
         char temp_str[32];
 
@@ -407,7 +412,9 @@ H5HF_iblock_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE *stream,
 {
     H5HF_t	*fh = NULL;             /* Fractal heap header info */
     H5HF_shared_t *shared;              /* Shared fractal heap information */
+    H5HF_parent_shared_t par_shared;    /* Parent shared information */
     H5HF_indirect_t *iblock = NULL;     /* Fractal heap direct block info */
+    size_t dblock_size;                 /* Current direct block size */
     char temp_str[64];                  /* Temporary string, for formatting */
     size_t	u, v;                   /* Local index variable */
     herr_t      ret_value = SUCCEED;    /* Return value */
@@ -438,7 +445,11 @@ H5HF_iblock_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE *stream,
     /*
      * Load the heap direct block
      */
-    if(NULL == (iblock = H5AC_protect(f, dxpl_id, H5AC_FHEAP_IBLOCK, addr, &nrows, fh->shared, H5AC_READ)))
+    par_shared.shared = fh->shared;
+    par_shared.parent = NULL;
+    par_shared.parent_entry = 0;
+    par_shared.parent_free_space = 0;
+    if(NULL == (iblock = H5AC_protect(f, dxpl_id, H5AC_FHEAP_IBLOCK, addr, &nrows, &par_shared, H5AC_READ)))
 	HGOTO_ERROR(H5E_HEAP, H5E_CANTLOAD, FAIL, "unable to load fractal heap indirect block")
 
     /* Release the heap header */
@@ -458,6 +469,9 @@ H5HF_iblock_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE *stream,
     HDfprintf(stream, "%*s%-*s %Hu\n", indent, "", fwidth,
 	      "Offset of indirect block in heap:",
 	      iblock->block_off);
+    HDfprintf(stream, "%*s%-*s %Hu\n", indent, "", fwidth,
+	      "Total children free space:",
+	      iblock->child_free_space);
     HDfprintf(stream, "%*s%-*s %Zu\n", indent, "", fwidth,
 	      "Size of indirect block:",
 	      iblock->size);
@@ -470,11 +484,27 @@ H5HF_iblock_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE *stream,
     HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
 	      "# of indirect rows:",
 	      iblock->nindir_rows);
+    HDfprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,
+	      "Direct blocks full:",
+	      (iblock->dir_full ? "TRUE" : "FALSE"));
+    HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
+	      "Max direct block rows:",
+	      iblock->max_direct_rows);
+    HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
+	      "Next direct block column:",
+	      iblock->next_dir_col);
+    HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
+	      "Next direct block row:",
+	      iblock->next_dir_row);
+    HDfprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
+	      "Next direct block size:",
+	      iblock->next_dir_size);
 
     /* Print the entry tables */
+    dblock_size = shared->man_dtable.cparam.start_block_size;
     HDfprintf(stream, "%*sDirect Block Entries (address, free space):\n", indent, "");
     for(u = 0; u < iblock->ndir_rows; u++) {
-        sprintf(temp_str, "Row #%u:", (unsigned)u);
+        sprintf(temp_str, "Row #%u: (block size: %lu)", (unsigned)u, (unsigned long)dblock_size);
         HDfprintf(stream, "%*s%-*s\n", indent + 3, "", MAX(0, fwidth - 3),
                 temp_str);
         for(v = 0; v < shared->man_dtable.cparam.width; v++) {
@@ -486,6 +516,7 @@ H5HF_iblock_debug(H5F_t *f, hid_t dxpl_id, haddr_t addr, FILE *stream,
                     iblock->dblock_ents[off].addr,
                     iblock->dblock_ents[off].free_space);
         } /* end for */
+        dblock_size *= 2;
     } /* end for */
     HDfprintf(stream, "%*sIndirect Block Entries:\n", indent, "");
     if(iblock->nindir_rows > 0) {
diff --git a/src/H5HFint.c b/src/H5HFint.c
index fce8640..627f6e6 100644
--- a/src/H5HFint.c
+++ b/src/H5HFint.c
@@ -86,15 +86,19 @@ static herr_t H5HF_shared_free(void *_shared);
 /* Direct block routines */
 static herr_t H5HF_dblock_section_node_free_cb(void *item, void UNUSED *key,
     void UNUSED *op_data);
-static herr_t H5HF_man_dblock_inc_size(H5HF_shared_t *shared);
-static herr_t H5HF_man_dblock_create(H5RC_t *fh_shared, hid_t dxpl_id,
-    size_t block_size, hsize_t block_off, haddr_t *addr_p);
+static herr_t H5HF_man_dblock_create(H5HF_parent_shared_t *par_shared,
+    hid_t dxpl_id, size_t block_size, hsize_t block_off, haddr_t *addr_p);
 static herr_t H5HF_man_dblock_new(H5RC_t *fh_shared, hid_t dxpl_id,
     size_t request);
+static herr_t H5HF_man_dblock_adj_free(H5HF_direct_t *dblock, ssize_t amt);
 
 /* Indirect block routines */
+static herr_t H5HF_man_iblock_inc_loc(H5HF_indirect_t *iblock);
+static H5HF_indirect_t * H5HF_man_iblock_place_dblock(H5RC_t *fh_shared, hid_t dxpl_id,
+    size_t min_dblock_size, haddr_t *addr_p, size_t *entry_p,
+    size_t *dblock_size);
 static herr_t H5HF_man_iblock_create(H5RC_t *fh_shared, hid_t dxpl_id,
-    hsize_t block_off, unsigned nrows, haddr_t *addr_p);
+    hsize_t block_off, unsigned nrows, unsigned max_dir_rows, haddr_t *addr_p);
 
 /*********************/
 /* Package Variables */
@@ -172,7 +176,6 @@ H5HF_dtable_init(const H5HF_shared_t *shared, H5HF_dtable_t *dtable)
             H5V_log2_of2(dtable->cparam.start_block_size)) + 2;
     dtable->num_id_first_row = dtable->cparam.start_block_size * dtable->cparam.width;
     dtable->max_dir_blk_off_size = H5HF_SIZEOF_OFFSET_LEN(dtable->cparam.max_direct_size);
-    dtable->next_dir_size = dtable->cparam.start_block_size;
 
     /* Build table of block sizes for each row */
     if(NULL == (dtable->row_block_size = H5MM_malloc(dtable->max_root_indirect_rows * sizeof(hsize_t))))
@@ -375,6 +378,9 @@ H5HF_shared_create(H5F_t *f, H5HF_t *fh, haddr_t fh_addr, H5HF_create_t *cparam)
     shared->ref_count_size = cparam->ref_count_size;
     HDmemcpy(&(shared->man_dtable.cparam), &(cparam->managed), sizeof(H5HF_dtable_cparam_t));
 
+    /* Set root table address */
+    shared->man_dtable.table_addr = HADDR_UNDEF;
+
     /* Note that the shared info is dirty (it's not written to the file yet) */
     shared->dirty = TRUE;
 
@@ -429,49 +435,62 @@ H5HF_shared_free(void *_shared)
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5HF_man_dblock_inc_size
+ * Function:	H5HF_man_iblock_inc_loc
  *
- * Purpose:	Increment size of next direct block
+ * Purpose:	Increment location of next direct block in indirect block
  *
  * Return:	SUCCEED/FAIL
  *
  * Programmer:	Quincey Koziol
  *		koziol@ncsa.uiuc.edu
- *		Mar  6 2006
+ *		Mar 14 2006
  *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5HF_man_dblock_inc_size(H5HF_shared_t *shared)
+H5HF_man_iblock_inc_loc(H5HF_indirect_t *iblock)
 {
-    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5HF_man_dblock_inc_size)
+    H5HF_shared_t *shared;              /* Pointer to shared heap info */
+
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5HF_man_iblock_inc_loc)
 
     /*
      * Check arguments.
      */
+    HDassert(iblock);
+
+    /* Get the pointer to the shared heap info */
+    shared = H5RC_GET_OBJ(iblock->shared);
     HDassert(shared);
 
-    /* Check for another block of the same size, in the same row */
-    if(shared->man_dtable.next_dir_col < shared->man_dtable.cparam.width) {
-        /* Move to next column in doubling table */
-        shared->man_dtable.next_dir_col++;
+    /* Increment column */
+    iblock->next_dir_col++;
+
+    /* Check for walking off end of column */
+    if(iblock->next_dir_col == shared->man_dtable.cparam.width) {
+        /* Reset column */
+        iblock->next_dir_col = 0;
+
+        /* Increment row & direct block size */
+        iblock->next_dir_row++;
+        iblock->next_dir_size *= 2;
+
+        /* Check for filling up all direct block entries in indirect block */
+        if(iblock->next_dir_row == iblock->max_direct_rows)
+            iblock->dir_full = TRUE;
     } /* end if */
-    else {
-        /* Check for "doubling" block to next row or resetting to initial size */
-/* XXX: The maximum size will vary for different indirect blocks... */
-        if(shared->man_dtable.next_dir_size < shared->man_dtable.cparam.max_direct_size)
-            /* Double block size */
-            shared->man_dtable.next_dir_size *= 2;
-        else
-            /* Reset to starting block size */
-            shared->man_dtable.next_dir_size = shared->man_dtable.cparam.start_block_size;
 
-        /* Set next column */
-        shared->man_dtable.next_dir_col = 0;
-    } /* end else */
+#ifdef QAK
+HDfprintf(stderr, "%s: iblock->next_dir_row = %u\n", "H5HF_man_iblock_inc_loc", iblock->next_dir_row);
+HDfprintf(stderr, "%s: iblock->next_dir_col = %u\n", "H5HF_man_iblock_inc_loc", iblock->next_dir_col);
+HDfprintf(stderr, "%s: iblock->next_dir_size = %Zu\n", "H5HF_man_iblock_inc_loc", iblock->next_dir_size);
+HDfprintf(stderr, "%s: iblock->dir_full = %u\n", "H5HF_man_iblock_inc_loc", (unsigned)iblock->dir_full);
+#endif /* QAK */
+    /* Mark heap header as modified */
+    shared->dirty = TRUE;
 
     FUNC_LEAVE_NOAPI(SUCCEED)
-} /* end H5HF_man_dblock_inc_size() */
+} /* end H5HF_man_iblock_inc_loc() */
 
 
 /*-------------------------------------------------------------------------
@@ -488,13 +507,14 @@ H5HF_man_dblock_inc_size(H5HF_shared_t *shared)
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5HF_man_dblock_create(H5RC_t *fh_shared, hid_t dxpl_id, 
+H5HF_man_dblock_create(H5HF_parent_shared_t *par_shared, hid_t dxpl_id, 
     size_t block_size, hsize_t block_off, haddr_t *addr_p)
 {
     H5HF_direct_free_node_t *node;      /* Pointer to free list node for block */
     H5HF_section_free_node_t *sec_node; /* Pointer to free list section for block */
     H5HF_shared_t *shared;              /* Pointer to shared heap info */
     H5HF_direct_t *dblock = NULL;       /* Pointer to direct block */
+    size_t free_space;                  /* Free space in new block */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT(H5HF_man_dblock_create)
@@ -502,7 +522,8 @@ H5HF_man_dblock_create(H5RC_t *fh_shared, hid_t dxpl_id,
     /*
      * Check arguments.
      */
-    HDassert(fh_shared);
+    HDassert(par_shared);
+    HDassert(par_shared->shared);
     HDassert(block_size > 0);
     HDassert(addr_p);
 
@@ -516,10 +537,10 @@ H5HF_man_dblock_create(H5RC_t *fh_shared, hid_t dxpl_id,
     HDmemset(&dblock->cache_info, 0, sizeof(H5AC_info_t));
 
     /* Share common heap information */
-    dblock->shared = fh_shared;
+    dblock->shared = par_shared->shared;
     H5RC_INC(dblock->shared);
 
-    /* Get the pointer to the shared B-tree info */
+    /* Get the pointer to the shared heap info */
     shared = H5RC_GET_OBJ(dblock->shared);
     HDassert(shared);
 
@@ -527,11 +548,16 @@ H5HF_man_dblock_create(H5RC_t *fh_shared, hid_t dxpl_id,
 #ifdef QAK
 HDfprintf(stderr, "%s: size = %Zu, block_off = %Hu\n", FUNC, block_size, block_off);
 #endif /* QAK */
+    dblock->parent = par_shared->parent;
+    if(dblock->parent)
+        H5RC_INC(dblock->parent);
+    dblock->parent_entry = par_shared->parent_entry;
     dblock->size = block_size;
     dblock->block_off = block_off;
     dblock->blk_off_size = H5HF_SIZEOF_OFFSET_LEN(block_size);
     dblock->free_list_head = H5HF_MAN_ABS_DIRECT_OVERHEAD_DBLOCK(shared, dblock);
-    dblock->blk_free_space = block_size - dblock->free_list_head;
+    dblock->blk_free_space = par_shared->parent_free_space;
+    free_space = block_size - dblock->free_list_head;
 
     /* Allocate buffer for block */
 /* XXX: Change to using free-list factories */
@@ -551,7 +577,7 @@ HDmemset(dblock->blk, 0, dblock->size);
         HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for direct block free list node")
 
     /* Set node's information */
-    node->size = dblock->blk_free_space;
+    node->size = free_space;
     node->my_offset = dblock->free_list_head;
     node->next_offset = 0;
     node->prev = node->next = NULL;
@@ -579,8 +605,11 @@ HDmemset(dblock->blk, 0, dblock->size);
     if(H5HF_flist_add(shared->flist, sec_node, &sec_node->sect_size, &sec_node->sect_addr) < 0)
 	HGOTO_ERROR(H5E_HEAP, H5E_CANTINIT, FAIL, "can't add direct block free space to global list")
 
+    /* Adjust free space to include new block's space */
+    if(H5HF_man_dblock_adj_free(dblock, (ssize_t)free_space) < 0)
+        HGOTO_ERROR(H5E_HEAP, H5E_CANTDEC, FAIL, "can't adjust free space for direct block & parents")
+
     /* Update shared heap info */
-    shared->total_man_free += dblock->blk_free_space;
     shared->total_size += dblock->size;
     shared->man_size += dblock->size;
 
@@ -673,7 +702,7 @@ H5HF_man_dblock_build_freelist(H5HF_direct_t *dblock, haddr_t dblock_addr)
         hsize_t prev_off;       /* Prev node offset in block */
         uint8_t *p;             /* Temporary pointer to free node info */
 
-        /* Get the pointer to the shared B-tree info */
+        /* Get the pointer to the shared heap info */
         shared = H5RC_GET_OBJ(dblock->shared);
         HDassert(shared);
 
@@ -697,6 +726,9 @@ H5HF_man_dblock_build_freelist(H5HF_direct_t *dblock, haddr_t dblock_addr)
         /* Attach to free list head */
         head->first = node;
 
+        /* Set block's free space */
+        dblock->blk_free_space = free_len;
+
         /* Create free list section node */
         if(NULL == (sec_node = H5FL_MALLOC(H5HF_section_free_node_t)))
             HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for direct block free list section")
@@ -736,6 +768,9 @@ H5HF_man_dblock_build_freelist(H5HF_direct_t *dblock, haddr_t dblock_addr)
             node->prev = prev_node;
             node->next = NULL;
 
+            /* Adjust block's free space */
+            dblock->blk_free_space += free_len;
+
             /* Create free list section node */
             if(NULL == (sec_node = H5FL_MALLOC(H5HF_section_free_node_t)))
                 HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for direct block free list section")
@@ -770,6 +805,87 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5HF_man_dblock_adj_free
+ *
+ * Purpose:	Adjust the free space for a direct block, and it's parents
+ *
+ * Return:	SUCCEED/FAIL
+ *
+ * Programmer:	Quincey Koziol
+ *		koziol@ncsa.uiuc.edu
+ *		Mar 14 2006
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5HF_man_dblock_adj_free(H5HF_direct_t *dblock, ssize_t amt)
+{
+    H5HF_shared_t *shared;              /* Shared heap information */
+
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5HF_man_dblock_adj_free)
+#ifdef QAK
+HDfprintf(stderr, "%s: amt = %Zd\n", "H5HF_man_dblock_adj_free", amt);
+#endif /* QAK */
+
+    /*
+     * Check arguments.
+     */
+    HDassert(dblock);
+
+    /* Get the pointer to the shared heap info */
+    shared = H5RC_GET_OBJ(dblock->shared);
+    HDassert(shared);
+
+    /* Adjust space available in block */
+    dblock->blk_free_space += amt;
+
+    /* Check if the parent info is set */
+    if(dblock->parent) {
+        H5HF_indirect_t *iblock;    /* Block's parent */
+
+        /* Get the pointer to the shared parent indirect block */
+        iblock = H5RC_GET_OBJ(dblock->parent);
+        HDassert(iblock);
+
+        /* Adjust this indirect block's child free space */
+#ifdef QAK
+HDfprintf(stderr, "%s: iblock->child_free_space = %Hu\n", "H5HF_man_dblock_adj_free", iblock->child_free_space);
+#endif /* QAK */
+        iblock->dblock_ents[dblock->parent_entry].free_space += amt;
+        iblock->child_free_space += amt;
+
+        /* Mark indirect block as dirty */
+        iblock->dirty = TRUE;
+
+        /* Modify the free space in parent block(s) */
+        while(iblock->parent) {
+            size_t parent_entry;            /* Entry in parent */
+
+            /* Get the pointer to the shared parent indirect block */
+            parent_entry = iblock->parent_entry;
+            iblock = H5RC_GET_OBJ(iblock->parent);
+            HDassert(iblock);
+
+            /* Adjust this indirect block's child free space */
+            iblock->iblock_ents[parent_entry].free_space += amt;
+            iblock->child_free_space += amt;
+
+            /* Mark indirect block as dirty */
+            iblock->dirty = TRUE;
+        } /* end while */
+    } /* end if */
+
+    /* Update shared heap free space info */
+    shared->total_man_free += amt;
+
+    /* Mark heap header as modified */
+    shared->dirty = TRUE;
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5HF_man_dblock_adj_free() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5HF_man_dblock_new
  *
  * Purpose:	Create a direct block large enough to hold an object of
@@ -786,8 +902,11 @@ done:
 static herr_t
 H5HF_man_dblock_new(H5RC_t *fh_shared, hid_t dxpl_id, size_t request)
 {
-    size_t min_dblock_size;             /* Min. size of direct block to allocate */
+    H5HF_parent_shared_t par_shared;    /* Parent shared information */
     H5HF_shared_t *shared;              /* Shared heap information */
+    haddr_t dblock_addr;                /* Address of new direct block */
+    size_t dblock_size;                 /* Size of new direct block */
+    size_t min_dblock_size;             /* Min. size of direct block to allocate */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT(H5HF_man_dblock_new)
@@ -823,106 +942,72 @@ HDfprintf(stderr, "%s: H5HF_MAN_ABS_DIRECT_OBJ_PREFIX_LEN_SIZE = %u\n", FUNC, H5
         min_dblock_size *= 2;
 #ifdef QAK
 HDfprintf(stderr, "%s: min_dblock_size = %Zu\n", FUNC, min_dblock_size);
-HDfprintf(stderr, "%s: shared->man_dtable.next_dir_size = %Zu\n", FUNC, shared->man_dtable.next_dir_size);
 #endif /* QAK */
 
-    /* Add direct block to heap */
-    if(min_dblock_size <= shared->man_dtable.next_dir_size) {
-        haddr_t dblock_addr;            /* Address of new direct block */
-        size_t dblock_size;             /* SIze of new direct block */
-
-        /* Create new direct block */
-        dblock_size = shared->man_dtable.next_dir_size;
-        if(H5HF_man_dblock_create(fh_shared, dxpl_id, dblock_size, shared->man_dtable.next_dir_block, &dblock_addr) < 0)
+    /* Check if this is the first block in the heap */
+    if(!H5F_addr_defined(shared->man_dtable.table_addr)) {
+        /* Create new direct block at corrent location*/
+        dblock_size = shared->man_dtable.cparam.start_block_size;
+        par_shared.shared = fh_shared;
+        par_shared.parent = NULL;
+        par_shared.parent_entry = 0;
+        par_shared.parent_free_space = 0;
+        if(H5HF_man_dblock_create(&par_shared, dxpl_id, dblock_size, shared->man_dtable.next_dir_block, &dblock_addr) < 0)
             HGOTO_ERROR(H5E_HEAP, H5E_CANTALLOC, FAIL, "can't allocate fractal heap direct block")
+
 #ifdef QAK
 HDfprintf(stderr, "%s: dblock_addr = %a\n", FUNC, dblock_addr);
 HDfprintf(stderr, "%s: shared->man_dtable.next_dir_block = %Hu\n", FUNC, shared->man_dtable.next_dir_block);
 #endif /* QAK */
 
-        /* Check if this is the first block in the heap */
-        if(shared->man_dtable.next_dir_block == 0) {
-            /* Point root at new direct block */
-            shared->man_dtable.curr_root_rows = 0;
-            shared->man_dtable.table_addr = dblock_addr;
-        } /* end if */
-        /* Check for the second block in the heap */
-        else if(shared->man_dtable.curr_root_rows == 0) {
-            H5HF_indirect_t *iblock = NULL; /* Pointer to indirect block to create */
-            H5HF_direct_t *dblock = NULL;   /* Pointer to direct block to query */
-            haddr_t iblock_addr;            /* Indirect block's address */
-            unsigned nrows;                 /* Number of rows for root indirect block */
-
-            /* Check for allocating entire root indirect block initially */
-            if(shared->man_dtable.cparam.start_root_rows == 0)
-                nrows = shared->man_dtable.max_root_indirect_rows;
-            else
-                nrows = shared->man_dtable.cparam.start_root_rows;
-
-            /* Allocate root indirect block */
-            if(H5HF_man_iblock_create(fh_shared, dxpl_id, (hsize_t)0, nrows, &iblock_addr) < 0)
-                HGOTO_ERROR(H5E_HEAP, H5E_CANTALLOC, FAIL, "can't allocate fractal heap indirect block")
+        /* Point root at new direct block */
+        shared->man_dtable.curr_root_rows = 0;
+        shared->man_dtable.table_addr = dblock_addr;
+    } /* end if */
+    /* Root entry already exists, go get indirect block for new direct block */
+    else {
+        H5HF_indirect_t *iblock;    /* Pointer to indirect block to create */
+        haddr_t iblock_addr;        /* Indirect block's address */
+        size_t dblock_entry;        /* Direct entry for new direct block */
+
+        /* Find indirect block with room for block of correct size */
+        if(NULL == (iblock = H5HF_man_iblock_place_dblock(fh_shared, dxpl_id, min_dblock_size, &iblock_addr, &dblock_entry, &dblock_size)))
+            HGOTO_ERROR(H5E_HEAP, H5E_CANTGET, FAIL, "unable to locate indirect block with space for direct block")
 #ifdef QAK
-HDfprintf(stderr, "%s: iblock_addr = %a\n", FUNC, iblock_addr);
+HDfprintf(stderr, "%s: dblock_entry = %Zu\n", FUNC, dblock_entry);
 #endif /* QAK */
 
-            /* Lock indirect block */
-            if(NULL == (iblock = H5AC_protect(shared->f, dxpl_id, H5AC_FHEAP_IBLOCK, iblock_addr, &nrows, fh_shared, H5AC_WRITE)))
-                HGOTO_ERROR(H5E_HEAP, H5E_CANTPROTECT, FAIL, "unable to protect fractal heap indirect block")
-
-            /* Lock first (root) direct block */
-            if(NULL == (dblock = H5AC_protect(shared->f, dxpl_id, H5AC_FHEAP_DBLOCK, shared->man_dtable.table_addr, &shared->man_dtable.cparam.start_block_size, fh_shared, H5AC_READ)))
-                HGOTO_ERROR(H5E_HEAP, H5E_CANTPROTECT, FAIL, "unable to protect fractal heap direct block")
-
-            /* Point indirect block at direct block to add */
-            iblock->dblock_ents[0].addr = shared->man_dtable.table_addr;
-            iblock->dblock_ents[0].free_space = dblock->blk_free_space;
-
-            /* Unlock first (root) direct block */
-            if(H5AC_unprotect(shared->f, dxpl_id, H5AC_FHEAP_DBLOCK, shared->man_dtable.table_addr, dblock, H5AC__NO_FLAGS_SET) < 0)
-                HDONE_ERROR(H5E_HEAP, H5E_CANTUNPROTECT, FAIL, "unable to release fractal heap direct block")
-            dblock = NULL;
-
-            /* Lock new direct block */
-            if(NULL == (dblock = H5AC_protect(shared->f, dxpl_id, H5AC_FHEAP_DBLOCK, dblock_addr, &shared->man_dtable.cparam.start_block_size, fh_shared, H5AC_READ)))
-                HGOTO_ERROR(H5E_HEAP, H5E_CANTPROTECT, FAIL, "unable to protect fractal heap direct block")
-
-            /* Point indirect block at new direct block */
-            iblock->dblock_ents[1].addr = dblock_addr;
-            iblock->dblock_ents[1].free_space = dblock->blk_free_space;
-
-            /* Unlock new direct block */
-            if(H5AC_unprotect(shared->f, dxpl_id, H5AC_FHEAP_DBLOCK, dblock_addr, dblock, H5AC__NO_FLAGS_SET) < 0)
-                HDONE_ERROR(H5E_HEAP, H5E_CANTUNPROTECT, FAIL, "unable to release fractal heap direct block")
-            dblock = NULL;
+        /* Create new direct block at corrent location*/
+        par_shared.shared = fh_shared;
+        par_shared.parent = iblock->self;
+        par_shared.parent_entry = dblock_entry;
+        par_shared.parent_free_space = 0;
+        if(H5HF_man_dblock_create(&par_shared, dxpl_id, dblock_size, shared->man_dtable.next_dir_block, &dblock_addr) < 0)
+            HGOTO_ERROR(H5E_HEAP, H5E_CANTALLOC, FAIL, "can't allocate fractal heap direct block")
 
-            /* Point heap header at new indirect block */
-            shared->man_dtable.curr_root_rows = nrows;
-            shared->man_dtable.table_addr = iblock_addr;
+#ifdef QAK
+HDfprintf(stderr, "%s: dblock_addr = %a\n", FUNC, dblock_addr);
+HDfprintf(stderr, "%s: shared->man_dtable.next_dir_block = %Hu\n", FUNC, shared->man_dtable.next_dir_block);
+#endif /* QAK */
 
-            /* Mark heap header as modified */
-            shared->dirty = TRUE;
+        /* Point indirect block at new direct block */
+        iblock->dblock_ents[dblock_entry].addr = dblock_addr;
 
-            /* Release the indirect block (marked as dirty) */
-            if(H5AC_unprotect(shared->f, dxpl_id, H5AC_FHEAP_IBLOCK, iblock_addr, iblock, H5AC__DIRTIED_FLAG) < 0)
-                HDONE_ERROR(H5E_HEAP, H5E_CANTUNPROTECT, FAIL, "unable to release fractal heap indirect block")
-        } /* end if */
-        else {
-HDfprintf(stderr, "%s: Adding >2nd direct block to heap not supported\n", FUNC);
-HGOTO_ERROR(H5E_HEAP, H5E_UNSUPPORTED, FAIL, "allocating objects from non root block not supported yet")
-        } /* end else */
+        /* Increment size of next block from this indirect block */
+        H5HF_man_iblock_inc_loc(iblock);
 
-        /* Update shared info */
-        shared->man_dtable.next_dir_block += dblock_size;
+        /* Mark indirect block as modified */
+        iblock->dirty = TRUE;
 
-        /* Increment size of next block */
-        H5HF_man_dblock_inc_size(shared);
-    } /* end if */
-    else {
-HDfprintf(stderr, "%s: Skipping direct block sizes not supported\n", FUNC);
-HGOTO_ERROR(H5E_HEAP, H5E_UNSUPPORTED, FAIL, "allocating objects from non root block not supported yet")
+        /* Release the indirect block (marked as dirty) */
+        if(H5AC_unprotect(shared->f, dxpl_id, H5AC_FHEAP_IBLOCK, iblock_addr, iblock, H5AC__DIRTIED_FLAG) < 0)
+            HDONE_ERROR(H5E_HEAP, H5E_CANTUNPROTECT, FAIL, "unable to release fractal heap indirect block")
     } /* end else */
 
+    /* Update shared info */
+/* XXX: This is going to cause problems when we support skipping blocks */
+    shared->man_dtable.next_dir_block += dblock_size;
+
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5HF_man_dblock_new() */
@@ -1113,23 +1198,26 @@ H5HF_man_insert(H5RC_t *fh_shared, hid_t dxpl_id, H5HF_section_free_node_t *sec_
                 HGOTO_ERROR(H5E_HEAP, H5E_CANTINIT, FAIL, "can't add direct block free space to global list")
         } /* end else */
 
+        /* Mark free list as dirty */
+        dblock->free_list->dirty = TRUE;
+
         /* Compute the size of the space to actually allocate */
         /* (includes the metadata for the object & the free space fragment) */
         alloc_obj_size = full_obj_size + free_frag_size;
 
-        /* Reduce space available in block */
-        dblock->blk_free_space -= alloc_obj_size;
-
-        /* Mark free list as dirty */
-        dblock->free_list->dirty = TRUE;
-
-        /* Point to location for object */
 #ifdef QAK
 HDfprintf(stderr, "%s: obj_off = %Zu\n", FUNC, obj_off);
 HDfprintf(stderr, "%s: free_frag_size = %Zu\n", FUNC, free_frag_size);
 HDfprintf(stderr, "%s: full_obj_size = %Zu\n", FUNC, full_obj_size);
 HDfprintf(stderr, "%s: alloc_obj_size = %Zu\n", FUNC, alloc_obj_size);
 #endif /* QAK */
+        /* Reduce space available in parent block(s) */
+        if(H5HF_man_dblock_adj_free(dblock, -(ssize_t)alloc_obj_size) < 0)
+            HGOTO_ERROR(H5E_HEAP, H5E_CANTDEC, FAIL, "can't adjust free space for direct block & parents")
+
+        /* Encode the object in the block */
+
+        /* Point to location for object */
         p = dblock->blk + obj_off;
 
         /* Encode the length */
@@ -1162,10 +1250,6 @@ HDfprintf(stderr, "%s: alloc_obj_size = %Zu\n", FUNC, alloc_obj_size);
 HDfprintf(stderr, "%s: dblock->block_off = %Hu\n", FUNC, dblock->block_off);
 #endif /* QAK */
         UINT64ENCODE_VAR(id, (dblock->block_off + obj_off), shared->heap_off_size);
-
-        /* Update shared heap info */
-        shared->total_man_free -= alloc_obj_size;
-
     } /* end if */
     else {
 HGOTO_ERROR(H5E_HEAP, H5E_UNSUPPORTED, FAIL, "inserting within mapped managed blocks not supported yet")
@@ -1187,11 +1271,284 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5HF_iblock_free
+ *
+ * Purpose:	Free fractal heap indirect block
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Quincey Koziol
+ *		koziol@ncsa.uiuc.edu
+ *		Mar 13 2006
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5HF_iblock_free(void *_iblock)
+{
+    H5HF_indirect_t *iblock = (H5HF_indirect_t *)_iblock;
+
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5HF_iblock_free)
+#ifdef QAK
+HDfprintf(stderr, "%s: Freeing indirect block\n", "H5HF_iblock_free");
+#endif /* QAK */
+
+    /* Sanity check */
+    HDassert(iblock);
+
+    /* Decrement reference count on shared fractal heap info */
+    if(iblock->shared)
+        H5RC_DEC(iblock->shared);
+    if(iblock->parent)
+        H5RC_DEC(iblock->parent);
+
+    /* Release entry tables */
+    if(iblock->dblock_ents)
+        H5FL_SEQ_FREE(H5HF_indirect_dblock_ent_t, iblock->dblock_ents);
+    if(iblock->iblock_ents)
+        H5FL_SEQ_FREE(H5HF_indirect_iblock_ent_t, iblock->iblock_ents);
+
+    /* Free fractal heap indirect block info */
+    H5FL_FREE(H5HF_indirect_t, iblock);
+
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5HF_iblock_free() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5HF_man_iblock_place_dblock
+ *
+ * Purpose:	Find indirect block with location for placing a direct block
+ *
+ * Note:	Creates necessary indirect blocks
+ *
+ * Return:	Pointer to indirect block on success, NULL on failure
+ *
+ * Programmer:	Quincey Koziol
+ *		koziol@ncsa.uiuc.edu
+ *		Mar 14 2006
+ *
+ *-------------------------------------------------------------------------
+ */
+static H5HF_indirect_t *
+H5HF_man_iblock_place_dblock(H5RC_t *fh_shared, hid_t dxpl_id,
+    size_t min_dblock_size, haddr_t *addr_p, size_t *entry_p,
+    size_t *dblock_size)
+{
+    H5HF_parent_shared_t par_shared;    /* Parent shared information */
+    H5HF_shared_t *shared;              /* Pointer to shared heap info */
+    H5HF_indirect_t *iblock;            /* Pointer to indirect block */
+    H5HF_indirect_t *ret_value;         /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT(H5HF_man_iblock_place_dblock)
+
+    /*
+     * Check arguments.
+     */
+    HDassert(fh_shared);
+    HDassert(min_dblock_size > 0);
+    HDassert(addr_p);
+
+    /* Get the pointer to the shared heap info */
+    shared = H5RC_GET_OBJ(fh_shared);
+    HDassert(shared);
+
+    /* Check for creating first indirect block */
+    if(shared->man_dtable.curr_root_rows == 0) {
+        H5HF_direct_t *dblock;          /* Pointer to direct block to query */
+        unsigned nrows;                 /* Number of rows for root indirect block */
+
+        /* Check for skipping over blocks */
+        if(min_dblock_size != shared->man_dtable.cparam.start_block_size) {
+HDfprintf(stderr, "%s: Skipping direct block sizes not supported\n", FUNC);
+HGOTO_ERROR(H5E_HEAP, H5E_UNSUPPORTED, NULL, "skipping direct block sizes not supported yet")
+        } /* end if */
+
+#ifdef QAK
+HDfprintf(stderr, "%s: creating first indirect block\n", FUNC);
+#endif /* QAK */
+        /* Check for allocating entire root indirect block initially */
+        if(shared->man_dtable.cparam.start_root_rows == 0)
+            nrows = shared->man_dtable.max_root_indirect_rows;
+        else
+            nrows = shared->man_dtable.cparam.start_root_rows;
+
+        /* Allocate root indirect block */
+        if(H5HF_man_iblock_create(fh_shared, dxpl_id, (hsize_t)0, nrows, shared->man_dtable.max_direct_rows, addr_p) < 0)
+            HGOTO_ERROR(H5E_HEAP, H5E_CANTALLOC, NULL, "can't allocate fractal heap indirect block")
+#ifdef QAK
+HDfprintf(stderr, "%s: *addr_p = %a\n", FUNC, *addr_p);
+#endif /* QAK */
+
+        /* Move current direct block (used as root) into new indirect block */
+
+        /* Lock new indirect block */
+        par_shared.shared = fh_shared;
+        par_shared.parent = NULL;
+        par_shared.parent_entry = 0;
+        par_shared.parent_free_space = 0;
+        if(NULL == (iblock = H5AC_protect(shared->f, dxpl_id, H5AC_FHEAP_IBLOCK, *addr_p, &nrows, &par_shared, H5AC_WRITE)))
+            HGOTO_ERROR(H5E_HEAP, H5E_CANTPROTECT, NULL, "unable to protect fractal heap indirect block")
+
+        /* Lock first (root) direct block */
+        par_shared.parent_free_space = shared->total_man_free;
+        if(NULL == (dblock = H5AC_protect(shared->f, dxpl_id, H5AC_FHEAP_DBLOCK, shared->man_dtable.table_addr, &shared->man_dtable.cparam.start_block_size, &par_shared, H5AC_READ)))
+            HGOTO_ERROR(H5E_HEAP, H5E_CANTPROTECT, NULL, "unable to protect fractal heap direct block")
+
+        /* Point indirect block at direct block to add */
+        iblock->dblock_ents[0].addr = shared->man_dtable.table_addr;
+        iblock->dblock_ents[0].free_space = dblock->blk_free_space;
+        iblock->child_free_space += dblock->blk_free_space;
+
+        /* Make direct block share parent indirect block */
+        dblock->parent = iblock->self;
+        dblock->parent_entry = 0;
+        H5RC_INC(dblock->parent);
+
+        /* Unlock first (root) direct block */
+        if(H5AC_unprotect(shared->f, dxpl_id, H5AC_FHEAP_DBLOCK, shared->man_dtable.table_addr, dblock, H5AC__NO_FLAGS_SET) < 0)
+            HDONE_ERROR(H5E_HEAP, H5E_CANTUNPROTECT, NULL, "unable to release fractal heap direct block")
+        dblock = NULL;
+
+        /* Increment size of next block from this indirect block */
+        /* (account for the already existing direct block */
+        H5HF_man_iblock_inc_loc(iblock);
+
+        /* Mark indirect block as modified */
+        iblock->dirty = TRUE;
+
+        /* Point heap header at new indirect block */
+        shared->man_dtable.curr_root_rows = nrows;
+        shared->man_dtable.table_addr = *addr_p;
+
+        /* Mark heap header as modified */
+        shared->dirty = TRUE;
+
+        /* Set entry for direct block */
+        *entry_p = 1;
+
+        /* Set size of direct block to create */
+        *dblock_size = iblock->next_dir_size;
+    } /* end if */
+    else {
+#ifdef QAK
+HDfprintf(stderr, "%s: searching root indirect block\n", FUNC);
+#endif /* QAK */
+
+        /* Lock root indirect block */
+        par_shared.shared = fh_shared;
+        par_shared.parent = NULL;
+        par_shared.parent_entry = 0;
+        par_shared.parent_free_space = shared->total_man_free;
+        if(NULL == (iblock = H5AC_protect(shared->f, dxpl_id, H5AC_FHEAP_IBLOCK, shared->man_dtable.table_addr, &shared->man_dtable.curr_root_rows, &par_shared, H5AC_WRITE)))
+            HGOTO_ERROR(H5E_HEAP, H5E_CANTPROTECT, NULL, "unable to protect fractal heap indirect block")
+
+#ifdef QAK
+HDfprintf(stderr, "%s: iblock->next_dir_row = %u\n", FUNC, iblock->next_dir_row);
+HDfprintf(stderr, "%s: iblock->next_dir_col = %u\n", FUNC, iblock->next_dir_col);
+HDfprintf(stderr, "%s: iblock->next_dir_size = %Zu\n", FUNC, iblock->next_dir_size);
+HDfprintf(stderr, "%s: iblock->dir_full = %u\n", FUNC, (unsigned)iblock->dir_full);
+#endif /* QAK */
+         /* Check for full direct block entries in root */
+         if(iblock->dir_full) {
+HDfprintf(stderr, "%s: Adding nested indirect block to heap not supported\n", FUNC);
+HGOTO_ERROR(H5E_HEAP, H5E_UNSUPPORTED, NULL, "Adding nested indirect block not supported yet")
+         } /* end if */
+
+        /* Check for skipping over blocks */
+        if(min_dblock_size > iblock->next_dir_size) {
+HDfprintf(stderr, "%s: Skipping direct block sizes not supported\n", FUNC);
+HGOTO_ERROR(H5E_HEAP, H5E_UNSUPPORTED, NULL, "skipping direct block sizes not supported yet")
+        } /* end if */
+
+        /* Check if we need a direct block past current allocation */
+        if(iblock->next_dir_row == iblock->ndir_rows) {
+            haddr_t old_addr;           /* Old address of indirect block */
+            unsigned new_nrows;         /* New # of direct rows */
+            size_t u;                   /* Local index variable */
+
+            /* Check for special case of second row, which has blocks the same size as first row */
+            if(iblock->next_dir_row == 1)
+                iblock->next_dir_size = shared->man_dtable.table_addr;
+
+            /* Compute new # of rows in indirect block */
+            new_nrows = 2 * iblock->ndir_rows;
+            if(new_nrows > iblock->max_direct_rows)
+                new_nrows = iblock->max_direct_rows;
+HDfprintf(stderr, "%s: new_nrows = %u\n", FUNC, new_nrows);
+
+/* Currently, the old chunk data is "thrown away" after the space is reallocated,
+ * so avoid data copy in H5MF_realloc() call by just free'ing the space and
+ * allocating new space.
+ *
+ * This should keep the file smaller also, by freeing the space and then
+ * allocating new space, instead of vice versa (in H5MF_realloc).
+ *
+ * QAK - 3/14/2006
+ */
+            /* Free previous indirect block disk space */
+            old_addr = shared->man_dtable.table_addr;
+            if(H5MF_xfree(shared->f, H5FD_MEM_FHEAP_IBLOCK, dxpl_id, old_addr, (hsize_t)iblock->size)<0)
+                HGOTO_ERROR(H5E_STORAGE, H5E_CANTFREE, NULL, "unable to free fractal heap indirect block")
+
+            /* Compute size of buffer needed for new indirect block */
+            iblock->ndir_rows = new_nrows;
+            iblock->size = H5HF_MAN_INDIRECT_SIZE(shared, iblock);
+
+            /* Mark indirect block as dirty */
+            iblock->dirty = TRUE;
+
+            /* Allocate space for the new indirect block on disk */
+            if(HADDR_UNDEF == (shared->man_dtable.table_addr = H5MF_alloc(shared->f, H5FD_MEM_FHEAP_IBLOCK, dxpl_id, (hsize_t)iblock->size)))
+                HGOTO_ERROR(H5E_STORAGE, H5E_NOSPACE, NULL, "file allocation failed for fractal heap indirect block")
+
+            /* Move object in cache */
+            if(H5AC_rename(shared->f, H5AC_FHEAP_IBLOCK, shared->man_dtable.table_addr, old_addr) < 0)
+                HGOTO_ERROR(H5E_HEAP, H5E_CANTSPLIT, NULL, "unable to move fractal heap root indirect block")
+
+            /* Re-allocate direct block entry table */
+            if(NULL == (iblock->dblock_ents = H5FL_SEQ_REALLOC(H5HF_indirect_dblock_ent_t, iblock->dblock_ents, (iblock->ndir_rows * shared->man_dtable.cparam.width))))
+                HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed for direct entries")
+
+            /* Initialize new direct block entries */
+            for(u = (iblock->next_dir_row * shared->man_dtable.cparam.width);
+                    u < (iblock->ndir_rows * shared->man_dtable.cparam.width);
+                    u++) {
+                iblock->dblock_ents[u].addr = HADDR_UNDEF;
+                iblock->dblock_ents[u].free_space = 0;
+            } /* end for */
+
+            /* Mark heap header as modified */
+            shared->dirty = TRUE;
+
+HDfprintf(stderr, "%s: Adding direct block of different size to heap not supported\n", FUNC);
+HGOTO_ERROR(H5E_HEAP, H5E_UNSUPPORTED, NULL, "allocating objects from non root block not supported yet")
+        } /* end if */
+
+        /* Set address of indirect block */
+        *addr_p = shared->man_dtable.table_addr;
+
+        /* Set entry for direct block */
+        *entry_p = iblock->next_dir_entry;
+
+        /* Set size of direct block to create */
+        *dblock_size = iblock->next_dir_size;
+    } /* end else */
+
+    /* Set return value */
+    ret_value = iblock;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5HF_man_iblock_place_dblock() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5HF_man_iblock_create
  *
  * Purpose:	Allocate & initialize a managed indirect block
  *
- * Return:	Pointer to new direct block on success, NULL on failure
+ * Return:	SUCCEED/FAIL
  *
  * Programmer:	Quincey Koziol
  *		koziol@ncsa.uiuc.edu
@@ -1201,7 +1558,7 @@ done:
  */
 static herr_t
 H5HF_man_iblock_create(H5RC_t *fh_shared, hid_t dxpl_id,
-    hsize_t block_off, unsigned nrows, haddr_t *addr_p)
+    hsize_t block_off, unsigned nrows, unsigned max_dir_rows, haddr_t *addr_p)
 {
     H5HF_shared_t *shared;              /* Pointer to shared heap info */
     H5HF_indirect_t *iblock = NULL;     /* Pointer to indirect block */
@@ -1230,16 +1587,29 @@ H5HF_man_iblock_create(H5RC_t *fh_shared, hid_t dxpl_id,
     iblock->shared = fh_shared;
     H5RC_INC(iblock->shared);
 
-    /* Get the pointer to the shared B-tree info */
+    /* Get the pointer to the shared heap info */
     shared = H5RC_GET_OBJ(iblock->shared);
     HDassert(shared);
 
+    /* Make a reference to this block */
+    if(NULL == (iblock->self = H5RC_create(iblock, H5HF_iblock_free)))
+	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "can't create ref-count wrapper for indirect fractal heap block")
+
 #ifdef QAK
 HDfprintf(stderr, "%s: nrows = %u\n", FUNC, nrows);
 #endif /* QAK */
     /* Set info for direct block */
+    iblock->parent = NULL;              /* Temporary, except for root indirect block */
+    iblock->parent_entry = 0;
     iblock->block_off = block_off;
+    iblock->child_free_space = 0;
     iblock->nrows = nrows;
+    iblock->dir_full = FALSE;
+    iblock->next_dir_col = 0;
+    iblock->next_dir_row = 0;
+    iblock->next_dir_entry = 0;
+    iblock->next_dir_size = shared->man_dtable.cparam.start_block_size;
+    iblock->max_direct_rows = max_dir_rows;
     if(iblock->nrows > shared->man_dtable.max_direct_rows) {
         iblock->ndir_rows = shared->man_dtable.max_direct_rows;
         iblock->nindir_rows = iblock->nrows - iblock->ndir_rows;
@@ -1270,9 +1640,9 @@ HDfprintf(stderr, "%s: nrows = %u\n", FUNC, nrows);
     for(u = 0; u < (iblock->nindir_rows * shared->man_dtable.cparam.width); u++)
         iblock->iblock_ents[u].addr = HADDR_UNDEF;
 
-    /* Allocate space for the header on disk */
+    /* Allocate space for the indirect block on disk */
     if(HADDR_UNDEF == (*addr_p = H5MF_alloc(shared->f, H5FD_MEM_FHEAP_IBLOCK, dxpl_id, (hsize_t)iblock->size)))
-	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "file allocation failed for fractal heap header")
+	HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "file allocation failed for fractal heap indirect block")
 
 /* XXX: Update indirect statistics when they are added */
 #ifdef LATER
diff --git a/src/H5HFpkg.h b/src/H5HFpkg.h
index 27085fd..7ccf879 100644
--- a/src/H5HFpkg.h
+++ b/src/H5HFpkg.h
@@ -66,8 +66,6 @@
     + H5F_SIZEOF_ADDR(f) /* File address of table managed */                  \
     + 2 /* Current # of rows in root indirect block */                        \
     + H5F_SIZEOF_SIZE(f) /* Next direct block's heap offset */                \
-    + H5F_SIZEOF_SIZE(f) /* Next direct block's size */                       \
-    + 2 /* Next direct block's column */                                      \
     )
 
 /* Size of the fractal heap header on disk */
@@ -121,7 +119,6 @@
     /* Fractal heap managed, absolutely mapped direct block specific fields */ \
     + H5F_SIZEOF_ADDR((s)->f)   /* File address of heap owning the block */   \
     + (s)->heap_off_size        /* Offset of the block in the heap */         \
-    + (d)->blk_off_size         /* Total free space in a block */             \
     + (d)->blk_off_size         /* Offset of first descriptor in free list */ \
     )
 
@@ -134,7 +131,7 @@
     + H5F_SIZEOF_ADDR((s)->f)   /* File address of heap owning the block */   \
     + (s)->heap_off_size        /* Offset of the block in the heap */         \
     + ((i)->ndir_rows * (s)->man_dtable.cparam.width * (H5F_SIZEOF_ADDR((s)->f) + (s)->man_dtable.max_dir_blk_off_size)) /* Size of entries for direct blocks */ \
-    + ((i)->nindir_rows * (s)->man_dtable.cparam.width * H5F_SIZEOF_ADDR((s)->f)) /* Size of entries for indirect blocks */ \
+    + ((i)->nindir_rows * (s)->man_dtable.cparam.width * (H5F_SIZEOF_ADDR((s)->f) + (s)->heap_off_size)) /* Size of entries for indirect blocks */ \
     )
 
 
@@ -159,9 +156,8 @@ typedef struct H5HF_dtable_t {
                                  * to direct block (of START_BLOCK_SIZE) instead
                                  * of indirect root block.
                                  */
+/* XXX: get rid of this global setting */
     hsize_t     next_dir_block; /* Offset of next direct managed block */
-    size_t      next_dir_size;  /* Size of next managed direct block */
-    unsigned    next_dir_col;   /* "Column" of next managed direct block (in doubling table) */
 
     /* Computed information (not stored) */
     unsigned    max_root_indirect_rows; /* Maximum # of rows in root indirect block */
@@ -246,7 +242,9 @@ typedef struct H5HF_direct_t {
     H5AC_info_t cache_info;
 
     /* Internal heap information */
-    H5RC_t	*shared;	/* Ref-counted shared info	              */
+    H5RC_t	*shared;	/* Ref-counted shared heap info	              */
+    H5RC_t	*parent;	/* Ref-counted shared parent block info       */
+    size_t      parent_entry;   /* Entry in parent's table                    */
     size_t      size;           /* Size of direct block                       */
     unsigned    blk_off_size;   /* Size of offsets in the block               */
     H5HF_direct_free_head_t *free_list; /* Pointer to free list for block     */
@@ -268,6 +266,7 @@ typedef struct H5HF_indirect_dblock_ent_t {
 /* Indirect block indirect block entry */
 typedef struct H5HF_indirect_iblock_ent_t {
     haddr_t     addr;           /* Indirect block's address                   */
+    hsize_t     free_space;     /* Amount of free space in indirect block child */
 } H5HF_indirect_iblock_ent_t;
 
 /* Fractal heap indirect block */
@@ -276,18 +275,37 @@ typedef struct H5HF_indirect_t {
     H5AC_info_t cache_info;
 
     /* Internal heap information */
+    hbool_t     dirty;          /* Info is modified                           */
     H5RC_t	*shared;	/* Ref-counted shared info	              */
+    H5RC_t	*parent;	/* Ref-counted shared parent block info       */
+    size_t      parent_entry;   /* Entry in parent's table                    */
+    H5RC_t	*self;		/* Ref-counted shared 'self' block info       */
     unsigned    nrows;          /* Total # of rows in indirect block          */
     unsigned    ndir_rows;      /* # of direct rows in indirect block         */
     unsigned    nindir_rows;    /* # of indirect rows in indirect block       */
     size_t      size;           /* Size of indirect block on disk             */
+    hbool_t     dir_full;       /* Flag to indicate that all direct blocks are allocated */
+    unsigned    next_dir_col;   /* "Column" of next managed direct block (in doubling table) */
+    unsigned    next_dir_row;   /* "Row" of next managed direct block (in doubling table) */
+    unsigned    next_dir_entry; /* Entry of next managed direct block         */
+    size_t      next_dir_size;  /* Size of next managed direct block          */
+    unsigned    max_direct_rows; /* Maximum # of direct rows in indirect block */
     H5HF_indirect_dblock_ent_t *dblock_ents;    /* Pointer to direct block entry table */
     H5HF_indirect_iblock_ent_t *iblock_ents;    /* Pointer to indirect block entry table */
 
     /* Stored values */
     hsize_t     block_off;      /* Offset of the block within the heap's address space */
+    hsize_t     child_free_space;   /* Total amount of free space in children */
 } H5HF_indirect_t;
 
+/* Shared information for parent of a fractal heap block */
+typedef struct H5HF_parent_shared_t {
+    H5RC_t	*shared;	/* Ref-counted shared heap info	              */
+    H5RC_t	*parent;	/* Ref-counted shared parent block info       */
+    size_t      parent_entry;   /* Entry in parent's table                    */
+    hsize_t     parent_free_space;      /* Free space in block, from parent   */
+} H5HF_parent_shared_t;
+
 /* Fractal heap metadata statistics info */
 typedef struct H5HF_stat_t {
     hsize_t total_size;         /* Total size of heap allocated (man & std)   */
@@ -345,6 +363,9 @@ H5_DLL H5HF_shared_t * H5HF_shared_alloc(H5F_t *f);
 H5_DLL herr_t H5HF_shared_create(H5F_t *f, H5HF_t *fh, haddr_t heap_addr, H5HF_create_t *cparam);
 H5_DLL herr_t H5HF_shared_own(H5HF_t *fh, H5HF_shared_t *shared);
 
+/* Indirect block routines */
+H5_DLL herr_t H5HF_iblock_free(void *_iblock);
+
 /* Routines for allocating space */
 H5_DLL herr_t H5HF_man_dblock_build_freelist(H5HF_direct_t *dblock, haddr_t dblock_addr);
 H5_DLL herr_t H5HF_man_find(H5RC_t *fh_shared, hid_t dxpl_id, size_t request,
diff --git a/src/H5HFstat.c b/src/H5HFstat.c
index 78be450..6cdc61b 100644
--- a/src/H5HFstat.c
+++ b/src/H5HFstat.c
@@ -37,6 +37,11 @@
 /****************/
 
 
+/********************/
+/* Package Typedefs */
+/********************/
+
+
 /******************/
 /* Local Typedefs */
 /******************/
diff --git a/src/H5HFtest.c b/src/H5HFtest.c
index 43c9573..c96d516 100644
--- a/src/H5HFtest.c
+++ b/src/H5HFtest.c
@@ -44,6 +44,11 @@
 
 
 /********************/
+/* Package Typedefs */
+/********************/
+
+
+/********************/
 /* Local Prototypes */
 /********************/
 
diff --git a/test/fheap.c b/test/fheap.c
index b20d333..8afaf36 100644
--- a/test/fheap.c
+++ b/test/fheap.c
@@ -175,7 +175,7 @@ fill_heap(H5F_t *f, hid_t dxpl, haddr_t fh_addr, hsize_t heap_size,
     /* Increment object count */
     nobjs++;
 
-    if(check_stats(f, H5P_DATASET_XFER_DEFAULT, fh_addr, heap_size, heap_size, (hsize_t)0, (hsize_t)(994 - (nobjs * (sizeof(obj) + 3))), (hsize_t)(start_nobjs + nobjs)))
+    if(check_stats(f, H5P_DATASET_XFER_DEFAULT, fh_addr, heap_size, heap_size, (hsize_t)0, (hsize_t)(996 - (nobjs * (sizeof(obj) + 3))), (hsize_t)(start_nobjs + nobjs)))
         FAIL_STACK_ERROR
 
     /* Get statistics for heap */
@@ -197,7 +197,7 @@ fill_heap(H5F_t *f, hid_t dxpl, haddr_t fh_addr, hsize_t heap_size,
         /* Increment object count */
         nobjs++;
 
-        if(check_stats(f, H5P_DATASET_XFER_DEFAULT, fh_addr, heap_size, heap_size, (hsize_t)0, (hsize_t)(994 - (nobjs * (sizeof(obj) + 3))), (hsize_t)(start_nobjs + nobjs)))
+        if(check_stats(f, H5P_DATASET_XFER_DEFAULT, fh_addr, heap_size, heap_size, (hsize_t)0, (hsize_t)(996 - (nobjs * (sizeof(obj) + 3))), (hsize_t)(start_nobjs + nobjs)))
             FAIL_STACK_ERROR
 
         /* Get statistics for heap */
@@ -386,7 +386,7 @@ test_abs_insert_first(hid_t fapl)
     heap_id = 0;
     if(H5HF_insert(f, dxpl, fh_addr, sizeof(obj), obj, &heap_id) < 0)
         FAIL_STACK_ERROR
-    if(check_stats(f, H5P_DATASET_XFER_DEFAULT, fh_addr, (hsize_t)1024, (hsize_t)1024, (hsize_t)0, (hsize_t)981, (hsize_t)1))
+    if(check_stats(f, H5P_DATASET_XFER_DEFAULT, fh_addr, (hsize_t)1024, (hsize_t)1024, (hsize_t)0, (hsize_t)983, (hsize_t)1))
         FAIL_STACK_ERROR
     PASSED()
 
@@ -464,13 +464,13 @@ test_abs_insert_second(hid_t fapl)
     heap_id = 0;
     if(H5HF_insert(f, dxpl, fh_addr, sizeof(obj), obj, &heap_id) < 0)
         FAIL_STACK_ERROR
-    if(check_stats(f, H5P_DATASET_XFER_DEFAULT, fh_addr, (hsize_t)1024, (hsize_t)1024, (hsize_t)0, (hsize_t)981, (hsize_t)1))
+    if(check_stats(f, H5P_DATASET_XFER_DEFAULT, fh_addr, (hsize_t)1024, (hsize_t)1024, (hsize_t)0, (hsize_t)983, (hsize_t)1))
         FAIL_STACK_ERROR
 
     heap_id = 0;
     if(H5HF_insert(f, dxpl, fh_addr, sizeof(obj2), obj2, &heap_id) < 0)
         FAIL_STACK_ERROR
-    if(check_stats(f, H5P_DATASET_XFER_DEFAULT, fh_addr, (hsize_t)1024, (hsize_t)1024, (hsize_t)0, (hsize_t)958, (hsize_t)2))
+    if(check_stats(f, H5P_DATASET_XFER_DEFAULT, fh_addr, (hsize_t)1024, (hsize_t)1024, (hsize_t)0, (hsize_t)960, (hsize_t)2))
         FAIL_STACK_ERROR
     PASSED()
 
@@ -629,7 +629,7 @@ test_abs_insert_force_indirect(hid_t fapl)
     /* Increment object count */
     nobjs++;
 
-    if(check_stats(f, H5P_DATASET_XFER_DEFAULT, fh_addr, (hsize_t)2048, (hsize_t)2048, (hsize_t)0, (hsize_t)981, (hsize_t)nobjs))
+    if(check_stats(f, H5P_DATASET_XFER_DEFAULT, fh_addr, (hsize_t)2048, (hsize_t)2048, (hsize_t)0, (hsize_t)983, (hsize_t)nobjs))
         FAIL_STACK_ERROR
 
     PASSED()
@@ -775,9 +775,6 @@ test_abs_insert_third_direct(hid_t fapl)
         FAIL_STACK_ERROR
     if(!H5F_addr_defined(fh_addr))
         FAIL_STACK_ERROR
-#ifndef QAK
-HDfprintf(stdout, "Fractal heap header address = %a\n", fh_addr);
-#endif /* QAK */
 
     /*
      * Test inserting mult. (small) objects to create third direct block
@@ -800,18 +797,191 @@ HDfprintf(stdout, "Fractal heap header address = %a\n", fh_addr);
     for(u = 0; u < sizeof(obj); u++)
         obj[u] = u + nobjs;
 
-    /* Insert another object, forcing the creation of an indirect block for the root block */
+    /* Insert another object, forcing the creation of the third direct block */
     heap_id = 0;
     if(H5HF_insert(f, dxpl, fh_addr, sizeof(obj), obj, &heap_id) < 0)
         FAIL_STACK_ERROR
+
+    /* Increment object count */
+    tot_nobjs++;
+
+    if(check_stats(f, H5P_DATASET_XFER_DEFAULT, fh_addr, (hsize_t)3072, (hsize_t)3072, (hsize_t)0, (hsize_t)983, (hsize_t)tot_nobjs))
+        FAIL_STACK_ERROR
+
+    PASSED()
+
+    /* Close the file */
+    if(H5Fclose(file) < 0)
+        TEST_ERROR
+
+    /* All tests passed */
+    return(0);
+
+error:
+    H5E_BEGIN_TRY {
+	H5Fclose(file);
+    } H5E_END_TRY;
+    return(1);
+} /* test_abs_insert_third_direct() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	test_abs_fill_first_row
+ *
+ * Purpose:	Test inserting mult. objects into absolute heap, creating
+ *              enough direct blocks to fill first row of root indirect
+ *              block.
+ *
+ * Return:	Success:	0
+ *
+ *		Failure:	1
+ *
+ * Programmer:	Quincey Koziol
+ *              Monday, March 13, 2006
+ *
+ *-------------------------------------------------------------------------
+ */
+static int
+test_abs_fill_first_row(hid_t fapl)
+{
+    hid_t	file = -1;              /* File ID */
+    hid_t       dxpl = H5P_DATASET_XFER_DEFAULT;     /* DXPL to use */
+    char	filename[1024];         /* Filename to use */
+    H5F_t	*f = NULL;              /* Internal file object pointer */
+    H5HF_create_t cparam;               /* Creation parameters for heap */
+    haddr_t     fh_addr;                /* Address of fractal heap created */
+    unsigned    nobjs = 0;              /* Number of objects inserted */
+    unsigned    tot_nobjs = 0;          /* Total number of objects inserted */
+    unsigned    u;                      /* Local index variable */
+
+    /* Set the filename to use for this test (dependent on fapl) */
+    h5_fixname(FILENAME[0], fapl, filename, sizeof(filename));
+
+    /* Create the file to work on */
+    if((file = H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, fapl)) < 0)
+        TEST_ERROR
+
+    /* Get a pointer to the internal file object */
+    if(NULL == (f = H5I_object(file)))
+        STACK_ERROR
+
+    /* Create absolute heap */
+    init_std_cparam(&cparam);
+    if(H5HF_create(f, dxpl, &cparam, &fh_addr/*out*/) < 0)
+        FAIL_STACK_ERROR
+    if(!H5F_addr_defined(fh_addr))
+        FAIL_STACK_ERROR
+
+    /*
+     * Test inserting mult. (small) objects to fill first row in root indirect block
+     */
+    TESTING("inserting enough objects to fill first row of root indirect block");
+
+    /* Loop over filling direct blocks, until first root indirect row is full */
+    for(u = 0; u < STD_MAN_WIDTH; u++) {
+        /* Fill a direct heap block up */
+        if(fill_heap(f, dxpl, fh_addr, (hsize_t)(u + 1) * STD_MAN_START_BLOCK_SIZE, tot_nobjs, &nobjs))
+            FAIL_STACK_ERROR
+        tot_nobjs += nobjs;
+    } /* end for */
+
+    PASSED()
+
+    /* Close the file */
+    if(H5Fclose(file) < 0)
+        TEST_ERROR
+
+    /* All tests passed */
+    return(0);
+
+error:
+    H5E_BEGIN_TRY {
+	H5Fclose(file);
+    } H5E_END_TRY;
+    return(1);
+} /* test_abs_fill_first_row() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	test_abs_start_second_row
+ *
+ * Purpose:	Test inserting mult. objects into absolute heap, creating
+ *              enough direct blocks to fill first row of root indirect
+ *              block, then add another object to start second row.
+ *
+ * Return:	Success:	0
+ *
+ *		Failure:	1
+ *
+ * Programmer:	Quincey Koziol
+ *              Tuesday, March 14, 2006
+ *
+ *-------------------------------------------------------------------------
+ */
+static int
+test_abs_start_second_row(hid_t fapl)
+{
+    hid_t	file = -1;              /* File ID */
+    hid_t       dxpl = H5P_DATASET_XFER_DEFAULT;     /* DXPL to use */
+    char	filename[1024];         /* Filename to use */
+    H5F_t	*f = NULL;              /* Internal file object pointer */
+    H5HF_create_t cparam;               /* Creation parameters for heap */
+    haddr_t     fh_addr;                /* Address of fractal heap created */
+    unsigned char obj[10];              /* Buffer for first object to insert */
+    hsize_t     heap_id;                /* Heap ID for object inserted */
+    unsigned    nobjs = 0;              /* Number of objects inserted */
+    unsigned    tot_nobjs = 0;          /* Total number of objects inserted */
+    unsigned    u;                      /* Local index variable */
+
+    /* Set the filename to use for this test (dependent on fapl) */
+    h5_fixname(FILENAME[0], fapl, filename, sizeof(filename));
+
+    /* Create the file to work on */
+    if((file = H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, fapl)) < 0)
+        TEST_ERROR
+
+    /* Get a pointer to the internal file object */
+    if(NULL == (f = H5I_object(file)))
+        STACK_ERROR
+
+    /* Create absolute heap */
+    init_std_cparam(&cparam);
+    if(H5HF_create(f, dxpl, &cparam, &fh_addr/*out*/) < 0)
+        FAIL_STACK_ERROR
+    if(!H5F_addr_defined(fh_addr))
+        FAIL_STACK_ERROR
 #ifndef QAK
-HDfprintf(stdout, "heap_id = %Hu\n", heap_id);
+HDfprintf(stderr, "Fractal heap header address = %a\n", fh_addr);
 #endif /* QAK */
 
+    /*
+     * Test inserting mult. (small) objects to start second row in root indirect block
+     */
+    TESTING("inserting enough objects to start second row of root indirect block");
+
+    /* Loop over filling direct blocks, until first root indirect row is full */
+    for(u = 0; u < STD_MAN_WIDTH; u++) {
+        /* Fill a direct heap block up */
+        if(fill_heap(f, dxpl, fh_addr, (hsize_t)(u + 1) * STD_MAN_START_BLOCK_SIZE, tot_nobjs, &nobjs))
+            FAIL_STACK_ERROR
+        tot_nobjs += nobjs;
+    } /* end for */
+
+    /* Insert one more object, to force root indirect block creation */
+
+    /* Initialize object buffer */
+    for(u = 0; u < sizeof(obj); u++)
+        obj[u] = u + tot_nobjs;
+
+    /* Insert another object, forcing the creation of an indirect block for the root block */
+    heap_id = 0;
+    if(H5HF_insert(f, dxpl, fh_addr, sizeof(obj), obj, &heap_id) < 0)
+        FAIL_STACK_ERROR
+
     /* Increment object count */
     nobjs++;
 
-    if(check_stats(f, H5P_DATASET_XFER_DEFAULT, fh_addr, (hsize_t)3072, (hsize_t)3072, (hsize_t)0, (hsize_t)982, (hsize_t)nobjs))
+    if(check_stats(f, H5P_DATASET_XFER_DEFAULT, fh_addr, (hsize_t)((STD_MAN_WIDTH + 1) * STD_MAN_START_BLOCK_SIZE), (hsize_t)((STD_MAN_WIDTH + 1) * STD_MAN_START_BLOCK_SIZE), (hsize_t)0, (hsize_t)983, (hsize_t)nobjs))
         FAIL_STACK_ERROR
 
     PASSED()
@@ -828,7 +998,7 @@ error:
 	H5Fclose(file);
     } H5E_END_TRY;
     return(1);
-} /* test_abs_insert_third_direct() */
+} /* test_abs_start_second_row() */
 
 
 /*-------------------------------------------------------------------------
@@ -865,11 +1035,15 @@ main(void)
     nerrors += test_abs_insert_root_mult(fapl);
     nerrors += test_abs_insert_force_indirect(fapl);
     nerrors += test_abs_insert_fill_second(fapl);
+    nerrors += test_abs_insert_third_direct(fapl);
+    nerrors += test_abs_fill_first_row(fapl);
 #else /* QAK */
 HDfprintf(stderr, "Uncomment tests!\n");
 #endif /* QAK */
 #ifdef QAK
-    nerrors += test_abs_insert_third_direct(fapl);
+    nerrors += test_abs_start_second_row(fapl);
+#else /* QAK */
+HDfprintf(stderr, "Uncomment tests!\n");
 #endif /* QAK */
 
     if(nerrors)