[svn-r290] Changes since 19980206

----------------------

./configure.in
./src/H5Fprivate.h
./src/H5Fsec2.c
	We now detect and use lseek64() on systems that have it (e.g.,
	Irix64) and are able to generate >2GB files on Irix XFS file
	systems (and anything else that supports large files).  This
	change also removed some warning messages from the Irix `-64'
	compiler.

	> $ ls -l istore.h5
	> -rw-r--r--    1 matzke   meshtv   8605436856 Feb 17 14:03 istore.h5

./configure.in
./src/H5Fprivate.h
./src/H5Fstdio.h
	We now detect and use fseek64() on systems that have it (e.g.,
	Irix64) and are able to generate >2GB files on Irix XFS file
	systems (and anything else that supports large files).  This
	change also removed some warning messages from the Iris `-64'
	compiler.

./src/H5E.c
./src/H5Epublic.h
	Added the H5E_OVERFLOW error to signal file address overflow.

./src/H5Fpublic.h
./examples/h5_chunk_read.c
./examples/h5_compound.c
./examples/h5_extend_write.c
./examples/h5_group.c
./examples/h5_read.c
./examples/h5_write.c
./html/Datasets.html
./html/Files.html
./html/H5.api.html
./html/H5.intro.html
./html/H5.sample_code.html
./html/ph5example.c
./html/review1.html
./test/cmpd_dset.c
./test/dsets.c
./test/extend.c
./test/tfile.c
./test/th5p.c
./test/theap.c
./test/tohdr.c
./test/tstab.c
./testpar/phdf5.c
	Renamed file access constants to follow the naming scheme.
	Also changed the base names a little to be more accurate as to
	what they do.  The old names H5ACC_WRITE and H5ACC_OVERWRITE
	will temporarily work.

	     H5ACC_DEFAULT     --> H5F_ACC_RDONLY for H5Fopen()
	     H5ACC_DEFAULT     --> H5F_ACC_EXCL   for H5Fcreate()
	     H5ACC_WRITE       --> H5F_ACC_RDWR
	     H5ACC_OVERWRITE   --> H5F_ACC_TRUNC

	Albert or Kim: The H5ACC_INDEPENDENT and H5ACC_COLLECTIVE
	macros in H5Fpublic.h should be an enum typedef and have names
	more like H5F_MPIO_INDEPENDENT and H5F_MPIO_COLLECTIVE.  Also
	change the access_mode argument of H5Cset_mpio().

	H5Fcreate() and H5Fopen() are more strict now about which
	flags are acceptable for the operation.

./src/H5Fprivate.h
./src/H5F.c
./src/H5C.c
	Changed the file access template to make it more general.  A
	union contains a struct for each type of low-level driver and
	the default template is initialized at run-time.

./src/H5Fpublic.h
./src/H5F.c
	Added H5Fget_access_template() and cleaned up
	H5Fget_create_template().

./src/H5C.c
	The H5Cset_mpi() no longer trashes the file access template
	when an error is detected.  We check for errors and *then*
	update the file access template.

	Added H5C_close() so Albert and Kim have a place to release
	the MPI communicator and info from the file access property
	list.

	Kim or Albert: I notice in H5Cset_mpi() you copy the MPI
	communicator.  Do you need to do something similar in
	H5C_copy()?

./src/H5F.c
	Added more error checking for the file creation and access
	property lists because it used to be possible to make the
	library dump core by swapping the creation and access property
	list ID numbers of H5Fcreate().

./test/istore.c
./test/tfile.c
./test/th5p.c
./test/theap.c
./test/tohdr.c
./test/tstab.c
./testpar/testphdf5.c
	One must pass H5C_DEFAULT as the file creation or access
	property list in order to get the default property list.  It
	is no longer possible to pass zero or any other arbitrary bad
	object ID.

./src/H5Fcore.c
./src/H5Ffamly.c
./src/H5Flow.c
./src/H5Fmpio.c
./src/H5Fsec2.c
./src/H5Fsplit.c
./src/H5Fstdio.c
./src/H5MF.c
	The file access property list is passed to all H5F_low_...()
	functions and to the drivers.

./src/H5Fcore.c
	The block size can be set at run time on a per-file basis
	instead of at compile time across all files. The "5000 items in
	a group test" now takes 1.6 seconds.

./src/H5private.h
	Removed inclusion of mpi.h and mpio.h since they're included
	from H5public.h.

./src/H5Cpublic.h
./src/H5C.c
	Added H5Cset_stdio(), H5Cset_sec2(), H5Cset_core(),
	H5Cset_split(), and H5Cset_family() in addition to the
	H5Cset_mpio() that Kim and Albert already wrote.  We still
	need the H5Cget_driver() and an H5Cget...() counterpart for
	each of those functions.  The split and family drivers still
	need a little work but I'm checking this in anyway.

18 files changed, 2359 insertions, 1648 deletions

diff --git a/src/H5C.c b/src/H5C.c
index 07e94dd..e04425e 100644
--- a/src/H5C.c
+++ b/src/H5C.c
@@ -58,6 +58,16 @@ H5C_init_interface(void)
 
     FUNC_ENTER(H5C_init_interface, FAIL);
 
+    /*
+     * Make sure the file creation and file access default templates are
+     * initialized since this might be done at run-time instead of compile
+     * time.
+     */
+    if (H5F_init_interface ()<0) {
+	HRETURN_ERROR (H5E_INTERNAL, H5E_CANTINIT, FAIL,
+		       "unable to initialize H5F and H5C interfaces");
+    }
+
     assert(H5C_NCLASSES <= H5_TEMPLATE_MAX - H5_TEMPLATE_0);
 
     /*
@@ -66,14 +76,15 @@ H5C_init_interface(void)
      * atom groups aren't.
      */
     for (i = 0; i < H5C_NCLASSES; i++) {
-        status = H5A_init_group((group_t)(H5_TEMPLATE_0 +i), H5A_TEMPID_HASHSIZE, 0, NULL);
-        if (status < 0)
-            ret_value = FAIL;
+        status = H5A_init_group((group_t)(H5_TEMPLATE_0 +i),
+				H5A_TEMPID_HASHSIZE, 0, NULL);
+        if (status < 0) ret_value = FAIL;
     }
     if (ret_value < 0) {
         HRETURN_ERROR(H5E_ATOM, H5E_CANTINIT, FAIL,
                       "unable to initialize atom group");
     }
+    
     /*
      * Register cleanup function.
      */
@@ -81,6 +92,7 @@ H5C_init_interface(void)
         HRETURN_ERROR(H5E_INTERNAL, H5E_CANTINIT, FAIL,
                       "unable to install atexit function");
     }
+    
     FUNC_LEAVE(ret_value);
 }
 
@@ -194,7 +206,7 @@ H5Ccreate(H5C_class_t type)
 hid_t
 H5C_create(H5C_class_t type, void *tmpl)
 {
-    hid_t                   ret_value = FAIL;
+    hid_t	ret_value = FAIL;
 
     FUNC_ENTER(H5C_create, FAIL);
 
@@ -203,10 +215,11 @@ H5C_create(H5C_class_t type, void *tmpl)
     assert(tmpl);
 
     /* Atomize the new template */
-    if ((ret_value = H5A_register((group_t)(H5_TEMPLATE_0 + type), tmpl)) < 0) {
+    if ((ret_value=H5A_register((group_t)(H5_TEMPLATE_0+type), tmpl)) < 0) {
         HRETURN_ERROR(H5E_ATOM, H5E_CANTINIT, FAIL,
                       "can't register template");
     }
+    
     FUNC_LEAVE(ret_value);
 }
 
@@ -226,21 +239,79 @@ H5C_create(H5C_class_t type, void *tmpl)
 herr_t
 H5Cclose(hid_t tid)
 {
-    void                   *tmpl = NULL;
+    H5C_class_t		type;
+    void                *tmpl = NULL;
 
     FUNC_ENTER(H5Cclose, FAIL);
 
-    /* Chuck the object! :-) */
-    if (NULL == (tmpl = H5A_remove(tid))) {
-        HRETURN_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "unable to remove atom");
+    /* Check arguments */
+    if ((type=H5Cget_class (tid))<0 ||
+	NULL==(tmpl=H5A_object (tid))) {
+        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a property list");
     }
+	
+    /*
+     * Chuck the object! This will fail when the reference count reaches zero
+     * since there is no free func registered for the property list groups.
+     */
+    if (H5A_dec_ref (tid)<0) {
+	H5ECLEAR;
+	H5C_close (type, tmpl);
+    }
+
+    FUNC_LEAVE (SUCCEED);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5C_close
+ *
+ * Purpose:	Closes a template and frees the memory associated with the
+ *		template.
+ *
+ * Return:	Success:	SUCCEED
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Wednesday, February 18, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5C_close (H5C_class_t type, void *tmpl)
+{
+    FUNC_ENTER (H5C_close, FAIL);
+
+    /* Check args */
+    assert (tmpl);
+
+    /* Some templates may need to do special things */
+    switch (type) {
+    case H5C_FILE_ACCESS:
 #ifdef LATER
-    /* this is for file access template too.  Need to free the COMM and INFO objects too. */
-#endif 
-    H5MM_xfree(tmpl);
+	/* Need to free the COMM and INFO objects too. */
+#endif
+	break;
+	
+    case H5C_FILE_CREATE:
+    case H5C_DATASET_CREATE:
+    case H5C_DATASET_XFER:
+	/*nothing to do*/
+	break;
+
+    default:
+	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL,
+		       "unknown property list class");
+    }
 
+    /* Free the template struct and return */
+    H5MM_xfree(tmpl);
     FUNC_LEAVE(SUCCEED);
 }
+
 
 /*-------------------------------------------------------------------------
  * Function:    H5Cget_class
@@ -857,6 +928,235 @@ H5Cget_chunk(hid_t tid, int max_ndims, size_t dim[] /*out */ )
 
     FUNC_LEAVE(tmpl->chunk_ndims);
 }
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Cset_stdio
+ *
+ * Purpose:	Set the low level file driver to use the functions declared
+ *		in the stdio.h file: fopen(), fseek() or fseek64(), fread(),
+ *		fwrite(), and fclose().
+ *
+ * Return:	Success:	SUCCEED
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, February 19, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Cset_stdio (hid_t tid)
+{
+    H5F_access_t	*tmpl = NULL;
+    
+    FUNC_ENTER (H5Cset_stdio, FAIL);
+
+    /* Check arguments */
+    if (H5C_FILE_ACCESS != H5Cget_class(tid) ||
+        NULL == (tmpl = H5A_object(tid))) {
+        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
+		      "not a file access template");
+    }
+
+    /* Set driver */
+    tmpl->driver = H5F_LOW_STDIO;
+
+    FUNC_LEAVE (SUCCEED);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Cset_sec2
+ *
+ * Purpose:	Set the low-level file driver to use the functions declared
+ *		in the unistd.h file: open(), lseek() or lseek64(), read(),
+ *		write(), and close().
+ *
+ * Return:	Success:	SUCCEED
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, February 19, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Cset_sec2 (hid_t tid)
+{
+    H5F_access_t	*tmpl = NULL;
+    
+    FUNC_ENTER (H5Cset_sec2, FAIL);
+
+    /* Check arguments */
+    if (H5C_FILE_ACCESS != H5Cget_class(tid) ||
+        NULL == (tmpl = H5A_object(tid))) {
+        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
+		      "not a file access template");
+    }
+
+    /* Set driver */
+    tmpl->driver = H5F_LOW_SEC2;
+
+    FUNC_LEAVE (SUCCEED);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Cset_core
+ *
+ * Purpose:	Set the low-level file driver to use malloc() and free().
+ *		This driver is restricted to temporary files which are not
+ *		larger than the amount of virtual memory available. The
+ *		INCREMENT argument determines the file block size and memory
+ *		will be allocated in multiples of INCREMENT bytes. A liberal
+ *		INCREMENT results in fewer calls to realloc() and probably
+ *		less memory fragmentation.
+ *
+ * Return:	Success:	SUCCEED
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, February 19, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Cset_core (hid_t tid, size_t increment)
+{
+    H5F_access_t	*tmpl = NULL;
+    
+    FUNC_ENTER (H5Cset_core, FAIL);
+
+    /* Check arguments */
+    if (H5C_FILE_ACCESS != H5Cget_class(tid) ||
+        NULL == (tmpl = H5A_object(tid))) {
+        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
+		      "not a file access template");
+    }
+    if (increment<1) {
+	HRETURN_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL,
+		       "increment must be positive");
+    }
+
+    /* Set driver */
+    tmpl->driver = H5F_LOW_CORE;
+    tmpl->u.core.increment = increment;
+
+    FUNC_LEAVE (SUCCEED);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Cset_split
+ *
+ * Purpose:	Set the low-level driver to split meta data from raw data,
+ *		storing meta data in one file and raw data in another file.
+ *
+ * Return:	Success:	SUCCEED
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, February 19, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Cset_split (hid_t tid, hid_t meta_tid, hid_t raw_tid)
+{
+    H5F_access_t	*tmpl = NULL;
+    H5F_access_t	*meta_tmpl = NULL;
+    H5F_access_t	*raw_tmpl = NULL;
+    
+    FUNC_ENTER (H5Cset_split, FAIL);
+
+    /* Check arguments */
+    if (H5C_FILE_ACCESS != H5Cget_class(tid) ||
+        NULL == (tmpl = H5A_object(tid))) {
+        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
+		      "not a file access template");
+    }
+    if (H5C_DEFAULT!=meta_tid &&
+	(H5C_FILE_ACCESS != H5Cget_class(meta_tid) ||
+	 NULL == (tmpl = H5A_object(meta_tid)))) {
+        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
+		      "not a file access template");
+    }
+    if (H5C_DEFAULT!=raw_tid &&
+	(H5C_FILE_ACCESS != H5Cget_class(raw_tid) ||
+	 NULL == (tmpl = H5A_object(raw_tid)))) {
+        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
+		      "not a file access template");
+    }
+
+    /* Set driver */
+    tmpl->driver = H5F_LOW_SPLIT;
+    tmpl->u.split.meta_access = H5C_copy (H5C_FILE_ACCESS, meta_tmpl);
+    tmpl->u.split.raw_access = H5C_copy (H5C_FILE_ACCESS, raw_tmpl);
+
+    FUNC_LEAVE (SUCCEED);
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Cset_family
+ *
+ * Purpose:	Sets the low-level driver to stripe the hdf5 address space
+ *		across a family of files.
+ *
+ * Return:	Success:	SUCCEED
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Thursday, February 19, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Cset_family (hid_t tid, hid_t memb_tid)
+{
+    
+    H5F_access_t	*tmpl = NULL;
+    H5F_access_t	*memb_tmpl = NULL;
+    
+    FUNC_ENTER (H5Cset_family, FAIL);
+
+    /* Check arguments */
+    if (H5C_FILE_ACCESS != H5Cget_class(tid) ||
+        NULL == (tmpl = H5A_object(tid))) {
+        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
+		      "not a file access template");
+    }
+    if (H5C_DEFAULT!=memb_tid &&
+	(H5C_FILE_ACCESS != H5Cget_class(memb_tid) ||
+	 NULL == (tmpl = H5A_object(memb_tid)))) {
+        HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
+		      "not a file access template");
+    }
+
+    /* Set driver */
+    tmpl->driver = H5F_LOW_FAMILY;
+    tmpl->u.fam.memb_access = H5C_copy (H5C_FILE_ACCESS, memb_tmpl);
+
+    FUNC_LEAVE (SUCCEED);
+}
+    
+    
 
 #ifdef HAVE_PARALLEL
 /*-------------------------------------------------------------------------
@@ -903,12 +1203,18 @@ H5Cget_chunk(hid_t tid, int max_ndims, size_t dim[] /*out */ )
  *
  * Modifications:
  *
+ * 	Robb Matzke, 18 Feb 1998
+ *	Check all arguments before the template is updated so we don't leave
+ *	the template in a bad state if something goes wrong.  Also, the
+ *	template data type changed to allow more generality so all the
+ *	mpi-related stuff is in the `u.mpi' member.  The `access_mode' will
+ *	contain only mpi-related flags defined in H5Fpublic.h.
+ *
  *-------------------------------------------------------------------------
  */
 herr_t
 H5Cset_mpi (hid_t tid, MPI_Comm comm, MPI_Info info, uintn access_mode)
 {
-    int                     i;
     H5F_access_t           *tmpl = NULL;
     MPI_Comm		    lcomm;
     int			    mrc;		/* MPI return code */
@@ -919,31 +1225,47 @@ H5Cset_mpi (hid_t tid, MPI_Comm comm, MPI_Info info, uintn access_mode)
     if (H5C_FILE_ACCESS != H5Cget_class(tid) ||
         NULL == (tmpl = H5A_object(tid))) {
         HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
-                      "not a file access template");
+		      "not a file access template");
     }
+    
     switch (access_mode){
     case H5ACC_INDEPENDENT:
-	    /* fall through to next case */
     case H5ACC_COLLECTIVE:
-	    tmpl->access_mode = access_mode;
-	    break;
+	/* okay */
+	break;
 
     default:
-            HRETURN_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
-	                          "unknown access_mode");
+	HRETURN_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL,
+		       "invalid mpio access mode");
     }
 
-    /* store a duplicate copy of comm so that user may freely modify comm after this */
-    /* call.  */
 #ifdef LATER
-    /* need to verify comm and info contain sensible information */
-    /* need to duplicate info too but don't know a quick way to do it now. */
+    /*
+     * Need to verify comm and info contain sensible information.
+     */
 #endif
-    if ((mrc = MPI_Comm_dup(comm, &lcomm)) != MPI_SUCCESS)
+
+
+    /*
+     * Everything looks good.  Now go ahead and modify the access template.
+     */
+    tmpl->driver = H5F_LOW_MPIO;
+    tmpl->u.mpio.access_mode = access_mode;
+
+    /*
+     * Store a duplicate copy of comm so that user may freely modify comm
+     * after this call.
+     */
+    if ((mrc = MPI_Comm_dup(comm, &lcomm)) != MPI_SUCCESS) {
         HRETURN_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL,
                       "failure to duplicate communicator");
-    tmpl->comm = comm;
-    tmpl->info = info;
+    }
+    tmpl->u.mpio.comm = comm;
+    
+#ifdef LATER
+    /* Need to duplicate info too but don't know a quick way to do it now */
+#endif
+    tmpl->u.mpio.info = info;
 
     FUNC_LEAVE(SUCCEED);
 }
@@ -1038,8 +1360,8 @@ H5C_copy (H5C_class_t type, const void *src)
         break;
 
     case H5C_FILE_ACCESS:
-        HRETURN_ERROR(H5E_INTERNAL, H5E_UNSUPPORTED, NULL,
-                      "file access properties are not implemented yet");
+	size = sizeof(H5F_access_t);
+	break;
 
     case H5C_DATASET_CREATE:
         size = sizeof(H5D_create_t);
diff --git a/src/H5Cprivate.h b/src/H5Cprivate.h
index 2c24a5b..a01df14 100644
--- a/src/H5Cprivate.h
+++ b/src/H5Cprivate.h
@@ -24,5 +24,6 @@
 
 hid_t H5C_create (H5C_class_t type, void *tmpl);
 void *H5C_copy (H5C_class_t type, const void *src);
+herr_t H5C_close (H5C_class_t type, void *tmpl);
 
 #endif
diff --git a/src/H5Cpublic.h b/src/H5Cpublic.h
index b3b5348..44444dc 100644
--- a/src/H5Cpublic.h
+++ b/src/H5Cpublic.h
@@ -61,6 +61,11 @@ herr_t H5Cset_layout (hid_t tid, H5D_layout_t layout);
 H5D_layout_t H5Cget_layout (hid_t tid);
 herr_t H5Cset_chunk (hid_t tid, int ndims, const size_t dim[]);
 int H5Cget_chunk (hid_t tid, int max_ndims, size_t dim[]/*out*/);
+herr_t H5Cset_stdio (hid_t tid);
+herr_t H5Cset_sec2 (hid_t tid);
+herr_t H5Cset_core (hid_t tid, size_t increment);
+herr_t H5Cset_split (hid_t tid, hid_t meta_tid, hid_t raw_tid);
+herr_t H5Cset_family (hid_t tid, hid_t memb_tid);
 #ifdef HAVE_PARALLEL
 herr_t H5Cset_mpi (hid_t tid, MPI_Comm comm, MPI_Info info, uintn access_mode);
 /* herr_t H5Cget_mpi (hid_t tid, int *ik); */  /* not defined yet */
diff --git a/src/H5E.c b/src/H5E.c
index f4fdda3..a60d4a7 100644
--- a/src/H5E.c
+++ b/src/H5E.c
@@ -77,6 +77,7 @@ static const H5E_minor_mesg_t H5E_minor_mesg_g[] =
     {H5E_READERROR, "Read failed"},
     {H5E_WRITEERROR, "Write failed"},
     {H5E_CLOSEERROR, "Close failed"},
+    {H5E_OVERFLOW, "Address overflowed"},
     {H5E_CANTINIT, "Can't initialize interface"},
     {H5E_ALREADYINIT, "Object already initialized"},
     {H5E_BADATOM, "Can't find atom information"},
diff --git a/src/H5Epublic.h b/src/H5Epublic.h
index 8a4c5b7..c71bd3a 100644
--- a/src/H5Epublic.h
+++ b/src/H5Epublic.h
@@ -76,6 +76,7 @@ typedef enum H5E_minor_t {
     H5E_READERROR,              /*read failed                                */
     H5E_WRITEERROR,             /*write failed                               */
     H5E_CLOSEERROR,             /*close failed                               */
+    H5E_OVERFLOW,		/*address overflowed			     */
 
     /* Function entry/exit interface errors */
     H5E_CANTINIT,               /*Can't initialize interface                 */
diff --git a/src/H5F.c b/src/H5F.c
index 5561c40..6e639c3 100644
--- a/src/H5F.c
+++ b/src/H5F.c
@@ -1,21 +1,21 @@
 /****************************************************************************
-* NCSA HDF                                                                 *
-* Software Development Group                                               *
-* National Center for Supercomputing Applications                          *
-* University of Illinois at Urbana-Champaign                               *
-* 605 E. Springfield, Champaign IL 61820                                   *
-*                                                                          *
-* For conditions of distribution and use, see the accompanying             *
-* hdf/COPYING file.                                                        *
+* NCSA HDF								   *
+* Software Development Group						   *
+* National Center for Supercomputing Applications			   *
+* University of Illinois at Urbana-Champaign				   *
+* 605 E. Springfield, Champaign IL 61820				   *
+*									   *
+* For conditions of distribution and use, see the accompanying		   *
+* hdf/COPYING file.							   *
 *
 * MODIFICATIONS
-*       Robb Matzke, 30 Aug 1997
-*       Added `ERRORS' fields to function prologues.
-*                                                                          *
+*	Robb Matzke, 30 Aug 1997
+*	Added `ERRORS' fields to function prologues.
+*									   *
 ****************************************************************************/
 
 #ifdef RCSID
-static char             RcsId[] = "@(#)$Revision$";
+static char		RcsId[] = "@(#)$Revision$";
 #endif
 
 /* $Id$ */
@@ -27,24 +27,24 @@ static char             RcsId[] = "@(#)$Revision$";
    HDF5 file I/O routines
 
    EXPORTED ROUTINES
-   H5Fcreate    -- Create an HDF5 file
-   H5Fclose     -- Close an open HDF5 file
+   H5Fcreate	-- Create an HDF5 file
+   H5Fclose	-- Close an open HDF5 file
 
    LIBRARY-SCOPED ROUTINES
 
    LOCAL ROUTINES
-   H5F_init_interface    -- initialize the H5F interface
+   H5F_init_interface	 -- initialize the H5F interface
  */
 
 /* Packages needed by this file... */
-#include <H5private.h>          /*library functions                       */
-#include <H5Aprivate.h>         /*atoms                                   */
-#include <H5ACprivate.h>        /*cache                                   */
-#include <H5Cprivate.h>         /*templates                               */
-#include <H5Eprivate.h>         /*error handling                  */
-#include <H5Gprivate.h>         /*symbol tables                           */
-#include <H5Mprivate.h>         /*meta data                               */
-#include <H5MMprivate.h>        /*core memory management          */
+#include <H5private.h>		/*library functions			  */
+#include <H5Aprivate.h>		/*atoms					  */
+#include <H5ACprivate.h>	/*cache					  */
+#include <H5Cprivate.h>		/*templates				  */
+#include <H5Eprivate.h>		/*error handling		  */
+#include <H5Gprivate.h>		/*symbol tables				  */
+#include <H5Mprivate.h>		/*meta data				  */
+#include <H5MMprivate.h>	/*core memory management	  */
 
 #include <ctype.h>
 #include <sys/types.h>
@@ -57,58 +57,53 @@ static char             RcsId[] = "@(#)$Revision$";
  */
 /* #define H5F_OPT_SEEK */
 
-#define PABLO_MASK      H5F_mask
+#define PABLO_MASK	H5F_mask
 
-/*--------------------- Locally scoped variables -----------------------------*/
+/*-------------------- Locally scoped variables -----------------------------*/
 
 /*
  * Define the default file creation template.
  */
-const H5F_create_t      H5F_create_dflt = {
-    0,                          /* Default user-block size */
-    4,                          /* Default 1/2 rank for symtab leaf nodes */
-    {                           /* Default 1/2 rank for btree intern nodes */
-        16,                     /* Symbol table internal nodes          */
-        32,                     /* Indexed storage internal nodes       */
-        0,                      /* unused                               */
-        0,                      /* unused                               */
-        0,                      /* unused                               */
-        0,                      /* unused                               */
-        0,                      /* unused                               */
-        0,                      /* unused                               */
+const H5F_create_t	H5F_create_dflt = {
+    0,				/* Default user-block size */
+    4,				/* Default 1/2 rank for symtab leaf nodes */
+    {				/* Default 1/2 rank for btree intern nodes */
+	16,			/* Symbol table internal nodes		*/
+	32,			/* Indexed storage internal nodes	*/
+	0,			/* unused				*/
+	0,			/* unused				*/
+	0,			/* unused				*/
+	0,			/* unused				*/
+	0,			/* unused				*/
+	0,			/* unused				*/
     },
-    4,             /* Default offset size */
-    4,             /* Default length size */
-    HDF5_BOOTBLOCK_VERSION,     /* Current Boot-Block version # */
-    HDF5_SMALLOBJECT_VERSION,   /* Current Small-Object heap version # */
-    HDF5_FREESPACE_VERSION,     /* Current Free-Space info version # */
-    HDF5_OBJECTDIR_VERSION,     /* Current Object Directory info version # */
-    HDF5_SHAREDHEADER_VERSION,  /* Current Shared-Header format version # */
+    4,		   /* Default offset size */
+    4,		   /* Default length size */
+    HDF5_BOOTBLOCK_VERSION,	/* Current Boot-Block version # */
+    HDF5_SMALLOBJECT_VERSION,	/* Current Small-Object heap version # */
+    HDF5_FREESPACE_VERSION,	/* Current Free-Space info version # */
+    HDF5_OBJECTDIR_VERSION,	/* Current Object Directory info version # */
+    HDF5_SHAREDHEADER_VERSION,	/* Current Shared-Header format version # */
 };
 
 /*
- * Define the default file access template.
+ * Define the default file access template.  The template is initialized by
+ * H5F_init_interface().
  */
-const H5F_access_t      H5F_access_dflt =
-{
-    H5ACC_DEFAULT,       	/* Default file access mode             */
-#ifdef HAVE_PARALLEL
-    MPI_COMM_NULL,              /* Default is not using MPIO            */
-    MPI_INFO_NULL,              /* Default no info                      */
-#endif
-};
+H5F_access_t H5F_access_dflt;
 
 /* Interface initialization */
-static intn             interface_initialize_g = FALSE;
+static intn interface_initialize_g = FALSE;
 #define INTERFACE_INIT H5F_init_interface
-static herr_t           H5F_init_interface(void);
-static void             H5F_term_interface(void);
+static void H5F_term_interface(void);
 
 /* PRIVATE PROTOTYPES */
-static H5F_t           *H5F_new(H5F_file_t *shared);
-static H5F_t           *H5F_dest(H5F_t *f);
-static herr_t           H5F_flush(H5F_t *f, hbool_t invalidate);
-static herr_t           H5F_locate_signature(H5F_low_t *f_handle, haddr_t *addr /*out */ );
+static H5F_t *H5F_new(H5F_file_t *shared);
+static H5F_t *H5F_dest(H5F_t *f);
+static herr_t H5F_flush(H5F_t *f, hbool_t invalidate);
+static herr_t H5F_locate_signature(H5F_low_t *f_handle,
+				   const H5F_access_t *access_parms,
+				   haddr_t *addr/*out*/);
 
 
 /*--------------------------------------------------------------------------
@@ -130,19 +125,43 @@ Modifications:
     It was already H5F_mask for the PABLO_TRACE_ON call.
 
 --------------------------------------------------------------------------*/
-static herr_t 
+herr_t 
 H5F_init_interface(void)
 {
-    herr_t                  ret_value = SUCCEED;
+    herr_t	ret_value = SUCCEED;
+    
     FUNC_ENTER(H5F_init_interface, FAIL);
 
     /* Initialize the atom group for the file IDs */
-    if ((ret_value = H5A_init_group(H5_FILE, H5A_FILEID_HASHSIZE, 0,
-				    (herr_t (*)(void*))H5Fclose)) != FAIL)
-        ret_value = H5_add_exit(&H5F_term_interface);
+    if (H5A_init_group(H5_FILE, H5A_FILEID_HASHSIZE, 0,
+		       (herr_t (*)(void*))H5Fclose)<0 ||
+	H5_add_exit(H5F_term_interface)<0) {	
+	HRETURN_ERROR (H5E_ATOM, H5E_CANTINIT, FAIL,
+		       "unable to initialize interface");
+    }
+
+    /* Initialize the default file access template */
+    H5F_access_dflt.driver = H5F_LOW_DFLT;
+    switch (H5F_LOW_DFLT) {
+    case H5F_LOW_STDIO:
+    case H5F_LOW_SEC2:
+    case H5F_LOW_CORE:
+    case H5F_LOW_SPLIT:
+    case H5F_LOW_FAMILY:
+	/* nothing more to init */
+	break;
+
+    case H5F_LOW_MPIO:
+#ifdef HAVE_PARALLEL
+	H5F_access_dflt.u.mpio.access_mode = 0;
+	H5F_access_dflt.u.mpio.comm = MPI_COMM_NULL;
+	H5F_access_dflt.u.mpio.info = MPI_INFO_NULL;
+#endif
+	break;
+    }
 
     FUNC_LEAVE(ret_value);
-}                               /* H5F_init_interface */
+}
 
 
 /*--------------------------------------------------------------------------
@@ -174,9 +193,9 @@ H5F_term_interface(void)
        H5F_encode_length_unusual -- encode an unusual length size
  USAGE
        void H5F_encode_length_unusual(f, p, l)
-       const H5F_t *f;             IN: pointer to the file record
-       uint8 **p;               IN: pointer to buffer pointer to encode length in
-       uint8 *l;                IN: pointer to length to encode
+       const H5F_t *f;		   IN: pointer to the file record
+       uint8 **p;		IN: pointer to buffer pointer to encode length in
+       uint8 *l;		IN: pointer to length to encode
 
  ERRORS
 
@@ -188,89 +207,132 @@ H5F_term_interface(void)
 void 
 H5F_encode_length_unusual(const H5F_t *f, uint8 **p, uint8 *l)
 {
-    intn                    i = (intn)H5F_SIZEOF_SIZE(f)-1;
+    intn		    i = (intn)H5F_SIZEOF_SIZE(f)-1;
 
 #ifdef WORDS_BIGENDIAN
     /*
      * For non-little-endian platforms, encode each byte in memory backwards.
      */
-    for (; i >= 0; i--, (*p)++)
-        *(*p) = *(l + i);
+    for (; i >= 0; i--, (*p)++) *(*p) = *(l + i);
 #else
     /* platform has little-endian integers */
     HDmemcpy(*p,l,i+1);
     *p+=(i+1);
 #endif
 
-#ifdef LATER
-  done:
-    if (ret_value == FALSE) {   /* Error condition cleanup */
-
-    }                           /* end if */
-#endif                       /* LATER */
-
-    /* Normal function cleanup */
-
-}                               /* H5F_encode_length_unusual */
+}
 
 
-/*--------------------------------------------------------------------------
- NAME
-    H5Fget_create_template
-
- PURPOSE
-    Get an atom for a copy of the file-creation template for this file
-
- USAGE
-    hid_t H5Fget_create_template(fid)
-        hid_t fid;    IN: File ID
-
- ERRORS
-    ATOM      BADATOM       Can't get file struct. 
-    FUNC      CANTCREATE    Can't create template. 
-    FUNC      CANTINIT      Can't init template. 
-
- RETURNS
-    Returns template ID on success, FAIL on failure
-
- DESCRIPTION
-        This function returns an atom with a copy of the template parameters
-    used to create a file.
---------------------------------------------------------------------------*/
+/*-------------------------------------------------------------------------
+ * Function:	H5Fget_create_template
+ *
+ * Purpose:	Get an atom for a copy of the file-creation template for this
+ *		file. This function returns an atom with a copy of the
+ *		template parameters used to create a file.
+ *
+ * Return:	Success:	template ID
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Unknown
+ *
+ * Modifications:
+ *
+ * 	Robb Matzke, 18 Feb 1998
+ *	Calls H5C_copy() to copy the template and H5C_close() to free that
+ *	template if an error occurs.
+ *
+ *-------------------------------------------------------------------------
+ */
 hid_t
 H5Fget_create_template(hid_t fid)
 {
-    H5F_t                  *file = NULL;
-    hid_t                   ret_value = FAIL;
-    H5F_create_t           *tmpl = NULL;
+    H5F_t		*file = NULL;
+    hid_t		ret_value = FAIL;
+    H5F_create_t	*tmpl = NULL;
 
     FUNC_ENTER(H5Fget_create_template, FAIL);
 
     /* check args */
-    if (H5_FILE != H5A_group(fid)) {
-        HRETURN_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "not a file");
-    }
-    if (NULL == (file = H5A_object(fid))) {
-        HRETURN_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't get file struct");
+    if (H5_FILE != H5A_group(fid) || NULL==(file=H5A_object (fid))) {
+	HRETURN_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file");
     }
+    
     /* Create the template object to return */
-    tmpl = H5MM_xmalloc(sizeof(H5F_create_t));
-    *tmpl = file->shared->create_parms;
+    if (NULL==(tmpl=H5C_copy (H5C_FILE_CREATE,
+			      &(file->shared->create_parms)))) {
+	HRETURN_ERROR (H5E_INTERNAL, H5E_CANTINIT, FAIL,
+		       "unable to copy file creation properties");
+    }
+
+    /* Create an atom */
     if ((ret_value = H5C_create(H5C_FILE_CREATE, tmpl)) < 0) {
-        HRETURN_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL,
-                      "can't register template");
+	H5C_close (H5C_FILE_CREATE, tmpl);
+	HRETURN_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL,
+		      "unable to register property list");
     }
+    
     FUNC_LEAVE(ret_value);
 }
 
 
+/*-------------------------------------------------------------------------
+ * Function:	H5Fget_access_template
+ *
+ * Purpose:	Returns a copy of the file access template of the specified
+ *		file.
+ *
+ * Return:	Success:	Object ID for a copy of the file access
+ *				template.
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Robb Matzke
+ *              Wednesday, February 18, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+hid_t
+H5Fget_access_template (hid_t file_id)
+{
+    H5F_t		*f = NULL;
+    H5F_access_t	*tmpl = NULL;
+    hid_t		ret_value = FAIL;
+    
+    FUNC_ENTER (H5Fget_access_template, FAIL);
+
+    /* Check args */
+    if (H5_FILE!=H5A_group (file_id) || NULL==(f=H5A_object (file_id))) {
+	HRETURN_ERROR (H5E_ARGS, H5E_BADTYPE, FAIL, "not a file");
+    }
+
+    /* Create the template object to return */
+    if (NULL==(tmpl=H5C_copy (H5C_FILE_ACCESS,
+			      &(f->shared->access_parms)))) {
+	HRETURN_ERROR (H5E_INTERNAL, H5E_CANTINIT, FAIL,
+		       "unable to copy file access properties");
+    }
+
+    /* Create an atom */
+    if ((ret_value = H5C_create (H5C_FILE_ACCESS, tmpl))<0) {
+	H5C_close (H5C_FILE_ACCESS, tmpl);
+	HRETURN_ERROR (H5E_ATOM, H5E_CANTREGISTER, FAIL,
+		       "unable to register property list");
+    }
+
+    FUNC_LEAVE (ret_value);
+}
+	    
+
 /*--------------------------------------------------------------------------
  NAME
        H5F_compare_files -- compare file objects for the atom API
  USAGE
        intn HPcompare_filename(obj, key)
-       const void * obj;             IN: pointer to the file record
-       const void * key;             IN: pointer to the search key
+       const void * obj;	     IN: pointer to the file record
+       const void * key;	     IN: pointer to the search key
 
  ERRORS
 
@@ -283,55 +345,57 @@ H5Fget_create_template(hid_t fid)
 static intn
 H5F_compare_files(const void * _obj, const void * _key)
 {
-    const H5F_t            *obj = (const H5F_t *) _obj;
-    const H5F_search_t     *key = (const H5F_search_t *) _key;
-    int                     ret_value = FALSE;
+    const H5F_t		*obj = (const H5F_t *) _obj;
+    const H5F_search_t	*key = (const H5F_search_t *) _key;
+    int			ret_value = FALSE;
 
     FUNC_ENTER(H5F_compare_files, FALSE);
 
     ret_value = (obj->shared->key.dev == key->dev &&
-                 obj->shared->key.ino == key->ino);
+		 obj->shared->key.ino == key->ino);
 
     FUNC_LEAVE(ret_value);
 }
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_locate_signature
+ * Function:	H5F_locate_signature
  *
- * Purpose:     Finds the HDF5 boot block signature in a file.  The signature
- *              can appear at address 0, or any power of two beginning with
- *              512.
+ * Purpose:	Finds the HDF5 boot block signature in a file.	The signature
+ *		can appear at address 0, or any power of two beginning with
+ *		512.
  *
- * Return:      Success:        SUCCEED.  The address of the signature is
- *                              returned through the ADDR argument.
+ * Return:	Success:	SUCCEED.  The address of the signature is
+ *				returned through the ADDR argument.
  *
- *              Failure:        FAIL
+ *		Failure:	FAIL
  *
- * Programmer:  Robb Matzke
- *              Friday, November  7, 1997
+ * Programmer:	Robb Matzke
+ *		Friday, November  7, 1997
  *
  * Modifications:
  *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F_locate_signature(H5F_low_t *f_handle, haddr_t *addr /*out */ )
+H5F_locate_signature(H5F_low_t *f_handle, const H5F_access_t *access_parms,
+		     haddr_t *addr/*out*/)
 {
-    haddr_t                 max_addr;
-    uint8                   buf[H5F_SIGNATURE_LEN];
-    uintn                   n = 9;
+    haddr_t		    max_addr;
+    uint8		    buf[H5F_SIGNATURE_LEN];
+    uintn		    n = 9;
 
     FUNC_ENTER(H5F_locate_signature, FAIL);
 
     H5F_low_size(f_handle, &max_addr);
     H5F_addr_reset(addr);
     while (H5F_addr_lt(addr, &max_addr)) {
-        if (H5F_low_read(f_handle, addr, H5F_SIGNATURE_LEN, buf) < 0) {
-            HRETURN_ERROR(H5E_IO, H5E_READERROR, FAIL, "can't read file");
-        }
-        if (!HDmemcmp(buf, H5F_SIGNATURE, H5F_SIGNATURE_LEN))
-            break;
-        H5F_addr_pow2(n++, addr);
+	if (H5F_low_read(f_handle, access_parms, addr,
+			 H5F_SIGNATURE_LEN, buf) < 0) {
+	    HRETURN_ERROR(H5E_IO, H5E_READERROR, FAIL, "can't read file");
+	}
+	if (!HDmemcmp(buf, H5F_SIGNATURE, H5F_SIGNATURE_LEN))
+	    break;
+	H5F_addr_pow2(n++, addr);
     }
 
     FUNC_LEAVE(SUCCEED);
@@ -347,14 +411,14 @@ H5F_locate_signature(H5F_low_t *f_handle, haddr_t *addr /*out */ )
 
  USAGE
     hbool_t H5Fis_hdf5(filename)
-        const char *filename;   IN: Name of the file to check
+	const char *filename;	IN: Name of the file to check
  ERRORS
-    ARGS      BADRANGE      No filename specified. 
-    FILE      BADFILE       Low-level file open failure. 
-    IO        READERROR     Read error. 
-    IO        READERROR     Seek error. 
-    IO        SEEKERROR     Unable to determine length of file due to seek
-                            failure. 
+    ARGS      BADRANGE	    No filename specified. 
+    FILE      BADFILE	    Low-level file open failure. 
+    IO	      READERROR	    Read error. 
+    IO	      READERROR	    Seek error. 
+    IO	      SEEKERROR	    Unable to determine length of file due to seek
+			    failure. 
 
  RETURNS
     TRUE/FALSE/FAIL
@@ -365,71 +429,80 @@ H5F_locate_signature(H5F_low_t *f_handle, haddr_t *addr /*out */ )
 hbool_t 
 H5Fis_hdf5(const char *filename)
 {
-    H5F_low_t              *f_handle = NULL;    /* file handle */
-    haddr_t                 addr;       /* Address of file signature & header */
-    hbool_t                 ret_value = FALSE;
+    H5F_low_t	*f_handle = NULL;	/* file handle */
+    haddr_t	addr;		       /* Address of file signature & header */
+    hbool_t	ret_value = FALSE;
+    const H5F_low_class_t *type = NULL;
 
     FUNC_ENTER(H5Fis_hdf5, FAIL);
 
     /* Check args and all the boring stuff. */
-    if (filename == NULL)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADRANGE, FAIL, "no filename specified");
+    if (filename == NULL) {
+	HGOTO_ERROR(H5E_ARGS, H5E_BADRANGE, FAIL, "no filename specified");
+    }
 
-    /* Open the file */
-    if (NULL == (f_handle = H5F_low_open(H5F_LOW_DFLT, filename, 0, NULL))) {
-        HGOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL,
-                    "low-level file open failure");
+    /* Open the file at the low level driver */
+    type = H5F_low_class (H5F_access_dflt.driver);
+    assert (type);
+    if (NULL == (f_handle = H5F_low_open(type, filename, &H5F_access_dflt,
+					 0, NULL))) {
+	HGOTO_ERROR(H5E_FILE, H5E_BADFILE, FAIL,
+		    "low-level file open failure");
     }
-    if (H5F_locate_signature(f_handle, &addr) >= 0) {
-        ret_value = TRUE;
+    if (H5F_locate_signature(f_handle, &H5F_access_dflt, &addr) >= 0) {
+	ret_value = TRUE;
     }
+    
   done:
-    H5F_low_close(f_handle);    /* close the file we opened */
+    if (f_handle) {
+	H5F_low_close(f_handle, &H5F_access_dflt); /*close the file we opened*/
+    }
+    
     FUNC_LEAVE(ret_value);
 }
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_new
+ * Function:	H5F_new
  *
- * Purpose:     Creates a new file object and initializes it.  The
- *              H5Fopen and H5Fcreate functions then fill in various
- *              fields.  If SHARED is a non-null pointer then the shared info
- *              to which it points has the reference count incremented.
- *              Otherwise a new, empty shared info struct is created.
+ * Purpose:	Creates a new file object and initializes it.  The
+ *		H5Fopen and H5Fcreate functions then fill in various
+ *		fields.	 If SHARED is a non-null pointer then the shared info
+ *		to which it points has the reference count incremented.
+ *		Otherwise a new, empty shared info struct is created.
  *
  * Errors:
  *
- * Return:      Success:        Ptr to a new file struct.
+ * Return:	Success:	Ptr to a new file struct.
  *
- *              Failure:        NULL
+ *		Failure:	NULL
  *
- * Programmer:  Robb Matzke
- *              matzke@llnl.gov
- *              Jul 18 1997
+ * Programmer:	Robb Matzke
+ *		matzke@llnl.gov
+ *		Jul 18 1997
  *
  * Modifications:
  *
  *-------------------------------------------------------------------------
  */
-static H5F_t           *
+static H5F_t *
 H5F_new(H5F_file_t *shared)
 {
-    H5F_t                  *f = NULL;
+    H5F_t		   *f = NULL;
     FUNC_ENTER(H5F_new, NULL);
 
     f = H5MM_xcalloc(1, sizeof(H5F_t));
     f->shared = shared;
 
     if (!f->shared) {
-        f->shared = H5MM_xcalloc(1, sizeof(H5F_file_t));
-        H5F_addr_undef(&(f->shared->boot_addr));
-        H5F_addr_undef(&(f->shared->base_addr));
-        H5F_addr_undef(&(f->shared->smallobj_addr));
-        H5F_addr_undef(&(f->shared->freespace_addr));
-        H5F_addr_undef(&(f->shared->hdf5_eof));
-
-        /* Create a main cache */
-        H5AC_create(f, H5AC_NSLOTS);
+	f->shared = H5MM_xcalloc(1, sizeof(H5F_file_t));
+	H5F_addr_undef(&(f->shared->boot_addr));
+	H5F_addr_undef(&(f->shared->base_addr));
+	H5F_addr_undef(&(f->shared->smallobj_addr));
+	H5F_addr_undef(&(f->shared->freespace_addr));
+	H5F_addr_undef(&(f->shared->hdf5_eof));
+
+	/* Create a main cache */
+	H5AC_create(f, H5AC_NSLOTS);
     }
     f->shared->nrefs++;
 
@@ -437,221 +510,174 @@ H5F_new(H5F_file_t *shared)
 }
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_dest
+ * Function:	H5F_dest
  *
- * Purpose:     Destroys a file structure.  This function does not flush
- *              the cache or anything else; it only frees memory associated
- *              with the file struct.  The shared info for the file is freed
- *              only when its reference count reaches zero.
+ * Purpose:	Destroys a file structure.  This function does not flush
+ *		the cache or anything else; it only frees memory associated
+ *		with the file struct.  The shared info for the file is freed
+ *		only when its reference count reaches zero.
  *
  * Errors:
  *
- * Return:      Success:        NULL
+ * Return:	Success:	NULL
  *
- *              Failure:        NULL
+ *		Failure:	NULL
  *
- * Programmer:  Robb Matzke
- *              matzke@llnl.gov
- *              Jul 18 1997
+ * Programmer:	Robb Matzke
+ *		matzke@llnl.gov
+ *		Jul 18 1997
  *
  * Modifications:
  *
  *-------------------------------------------------------------------------
  */
-static H5F_t           *
+static H5F_t *
 H5F_dest(H5F_t *f)
 {
     FUNC_ENTER(H5F_dest, NULL);
 
     if (f) {
-        if (0 == --(f->shared->nrefs)) {
-            H5AC_dest(f);
-            f->shared->root_ent = H5MM_xfree(f->shared->root_ent);
-            f->shared = H5MM_xfree(f->shared);
-        }
-        f->name = H5MM_xfree(f->name);
-        H5MM_xfree(f);
+	if (0 == --(f->shared->nrefs)) {
+	    H5AC_dest(f);
+	    f->shared->root_ent = H5MM_xfree(f->shared->root_ent);
+	    f->shared = H5MM_xfree(f->shared);
+	}
+	f->name = H5MM_xfree(f->name);
+	H5MM_xfree(f);
     }
     FUNC_LEAVE(NULL);
 }
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_open
- *
- * Purpose:     Opens (or creates) a file.  This function understands the
- *              following flags which are similar in nature to the Posix
- *              open(2) flags.
+ * Function:	H5F_open
  *
- *              H5F_ACC_WRITE:  Open with read/write access. If the file is
- *                              currently open for read-only access then it
- *                              will be reopened. Absence of this flag
- *                              implies read-only access.
+ * Purpose:	Opens (or creates) a file.  This function understands the
+ *		following flags which are similar in nature to the Posix
+ *		open(2) flags.
  *
- *              H5F_ACC_CREAT:  Create a new file if it doesn't exist yet.
- *                              The permissions are 0666 bit-wise AND with
- *                              the current umask.  H5F_ACC_WRITE must also
- *                              be specified.
+ *		H5F_ACC_WRITE:	Open with read/write access. If the file is
+ *				currently open for read-only access then it
+ *				will be reopened. Absence of this flag
+ *				implies read-only access.
  *
- *              H5F_ACC_EXCL:   This flag causes H5F_open() to fail if the
- *                              file already exists.
+ *		H5F_ACC_CREAT:	Create a new file if it doesn't exist yet.
+ *				The permissions are 0666 bit-wise AND with
+ *				the current umask.  H5F_ACC_WRITE must also
+ *				be specified.
  *
- *              H5F_ACC_TRUNC:  The file is truncated and a new HDF5 boot
- *                              block is written.  This operation will fail
- *                              if the file is already open.
+ *		H5F_ACC_EXCL:	This flag causes H5F_open() to fail if the
+ *				file already exists.
  *
- *              Unlinking the file name from the group directed graph while
- *              the file is opened causes the file to continue to exist but
- *              one will not be able to upgrade the file from read-only
- *              access to read-write access by reopening it. Disk resources
- *              for the file are released when all handles to the file are
- *              closed. NOTE: This paragraph probably only applies to Unix;
- *              deleting the file name in other OS's has undefined results.
+ *		H5F_ACC_TRUNC:	The file is truncated and a new HDF5 boot
+ *				block is written.  This operation will fail
+ *				if the file is already open.
  *
- *              The CREATE_PARMS argument is optional.  A null pointer will
- *              cause the default file creation parameters to be used.
+ *		Unlinking the file name from the group directed graph while
+ *		the file is opened causes the file to continue to exist but
+ *		one will not be able to upgrade the file from read-only
+ *		access to read-write access by reopening it. Disk resources
+ *		for the file are released when all handles to the file are
+ *		closed. NOTE: This paragraph probably only applies to Unix;
+ *		deleting the file name in other OS's has undefined results.
  *
- *              The ACCESS_PARMS argument is not used yet.
+ *		The CREATE_PARMS argument is optional.	A null pointer will
+ *		cause the default file creation parameters to be used.
  *
- *              The TYPE argument determins the low-level type of file that
- *              is opened.  The special value H5F_LOW_DFLT uses the default
- *              method which is defined at compile time.
+ *		The ACCESS_PARMS argument is optional.  A null pointer will
+ *		cause the default file access parameters to be used.
  *
  * Errors:
- *              ATOM      BADATOM       Can't unatomize default template
- *                                      id. 
- *              FILE      BADVALUE      Can't create file without write
- *                                      intent. 
- *              FILE      BADVALUE      Can't truncate without write intent. 
- *              FILE      CANTCREATE    Can't create file. 
- *              FILE      CANTCREATE    Can't truncate file. 
- *              FILE      CANTINIT      Can't get default file create template
- *                                      id. 
- *              FILE      CANTINIT      Can't write file boot block. 
- *              FILE      CANTOPENFILE  Bad address size. 
- *              FILE      CANTOPENFILE  Bad boot block version number. 
- *              FILE      CANTOPENFILE  Bad free space version number. 
- *              FILE      CANTOPENFILE  Bad length size. 
- *              FILE      CANTOPENFILE  Bad object dir version number. 
- *              FILE      CANTOPENFILE  Bad shared header version number. 
- *              FILE      CANTOPENFILE  Bad small object heap version number. 
- *              FILE      CANTOPENFILE  Bad symbol table internal node 1/2
- *                                      rank. 
- *              FILE      CANTOPENFILE  Bad symbol table leaf node 1/2 rank. 
- *              FILE      CANTOPENFILE  Can't read root symbol entry. 
- *              FILE      CANTOPENFILE  Cannot open existing file. 
- *              FILE      CANTOPENFILE  File cannot be reopened with write
- *                                      access. 
- *              FILE      CANTOPENFILE  File does not exist. 
- *              FILE      CANTOPENFILE  Invalid file family name. 
- *              FILE      FILEEXISTS    File already exists - CREAT EXCL
- *                                      failed. 
- *              FILE      FILEOPEN      File already open - TRUNC failed. 
- *              FILE      NOTHDF5       Can't find signature. 
- *              FILE      NOTHDF5       Can't read boot block. 
- *              FILE      READERROR     File is not readable. 
- *              FILE      TRUNCATED     Truncated file? 
- *              FILE      WRITEERROR    File is not writable. 
- *              IO        READERROR     Can't read boot block. 
- *
- * Return:      Success:        Ptr to the file pointer.
- *
- *              Failure:        NULL
- *
- * Programmer:  Robb Matzke
- *              Tuesday, September 23, 1997
+ *		ATOM	  BADATOM	Can't unatomize default template
+ *					id. 
+ *		FILE	  BADVALUE	Can't create file without write
+ *					intent. 
+ *		FILE	  BADVALUE	Can't truncate without write intent. 
+ *		FILE	  CANTCREATE	Can't create file. 
+ *		FILE	  CANTCREATE	Can't truncate file. 
+ *		FILE	  CANTINIT	Can't get default file create template
+ *					id. 
+ *		FILE	  CANTINIT	Can't write file boot block. 
+ *		FILE	  CANTOPENFILE	Bad address size. 
+ *		FILE	  CANTOPENFILE	Bad boot block version number. 
+ *		FILE	  CANTOPENFILE	Bad free space version number. 
+ *		FILE	  CANTOPENFILE	Bad length size. 
+ *		FILE	  CANTOPENFILE	Bad object dir version number. 
+ *		FILE	  CANTOPENFILE	Bad shared header version number. 
+ *		FILE	  CANTOPENFILE	Bad small object heap version number. 
+ *		FILE	  CANTOPENFILE	Bad symbol table internal node 1/2
+ *					rank. 
+ *		FILE	  CANTOPENFILE	Bad symbol table leaf node 1/2 rank. 
+ *		FILE	  CANTOPENFILE	Can't read root symbol entry. 
+ *		FILE	  CANTOPENFILE	Cannot open existing file. 
+ *		FILE	  CANTOPENFILE	File cannot be reopened with write
+ *					access. 
+ *		FILE	  CANTOPENFILE	File does not exist. 
+ *		FILE	  CANTOPENFILE	Invalid file family name. 
+ *		FILE	  FILEEXISTS	File already exists - CREAT EXCL
+ *					failed. 
+ *		FILE	  FILEOPEN	File already open - TRUNC failed. 
+ *		FILE	  NOTHDF5	Can't find signature. 
+ *		FILE	  NOTHDF5	Can't read boot block. 
+ *		FILE	  READERROR	File is not readable. 
+ *		FILE	  TRUNCATED	Truncated file? 
+ *		FILE	  WRITEERROR	File is not writable. 
+ *		IO	  READERROR	Can't read boot block. 
+ *
+ * Return:	Success:	Ptr to the file pointer.
+ *
+ *		Failure:	NULL
+ *
+ * Programmer:	Robb Matzke
+ *		Tuesday, September 23, 1997
  *
  * Modifications:
  *
- *      Robb Matzke, 11 Nov 1997
- *      If the name contains the pattern /[^%]%\d*[duxX]/ then the file is
- *      assumed to be a family of files.  The TYPE argument is ignored and
- *      H5F_LOW_FAM is used instead.
+ *	Robb Matzke, 11 Nov 1997
+ *	If the name contains the pattern /[^%]%\d*[duxX]/ then the file is
+ *	assumed to be a family of files.  The TYPE argument is ignored and
+ *	H5F_LOW_FAM is used instead.
+ *
+ *	Albert Cheng, 5 Feb 1998
+ *	Added the access_parms argument to pass down access template
+ *	information.
  *
- *      Albert Cheng, 5 Feb 1998
- *      Added the access_parms argument to pass down access template
- *      information.
+ * 	Robb Matzke, 18 Feb 1998
+ *	The H5F_access_t changed to allow more generality.  The low level
+ *	driver is part of the file access template so the TYPE argument has
+ *	been removed.
  *
  *-------------------------------------------------------------------------
  */
-H5F_t                  *
-H5F_open(const H5F_low_class_t *type, const char *name, uintn flags,
-         const H5F_create_t *create_parms, const H5F_access_t *access_parms)
+H5F_t *
+H5F_open(const char *name, uintn flags,
+	 const H5F_create_t *create_parms, const H5F_access_t *access_parms)
 {
-    H5F_t                  *f = NULL;   /*return value                  */
-    H5F_t                  *ret_value = NULL;   /*a copy of `f'                 */
-    H5F_t                  *old = NULL;         /*a file already opened         */
-    H5F_search_t            search;     /*file search key               */
-    H5F_low_t              *fd = NULL;  /*low level file desc           */
-    hbool_t                 empty_file = FALSE;         /*is file empty?                */
-    hbool_t                 file_exists = FALSE;        /*file already exists           */
-    uint8                   buf[256];   /*I/O buffer..                  */
-    const uint8            *p = NULL;   /*         ..and pointer into it */
-    size_t                  fixed_size = 24;    /*size of fixed part of boot blk */
-    size_t                  variable_size;      /*variable part of boot block   */
-    H5F_create_t           *cp = NULL;  /*file creation parameters      */
-    haddr_t                 addr1, addr2;       /*temporary address             */
-    H5G_entry_t             root_ent;   /*root symbol table entry       */
-    const char             *s = name;
+    H5F_t		*f = NULL;	/*return value			*/
+    H5F_t		*ret_value = NULL; /*a copy of `f'		*/
+    H5F_t		*old = NULL;	/*a file already opened		*/
+    H5F_search_t	search;		/*file search key		*/
+    H5F_low_t		*fd = NULL;	/*low level file desc		*/
+    hbool_t		empty_file = FALSE; /*is file empty?		*/
+    hbool_t		file_exists = FALSE; /*file already exists	*/
+    uint8		buf[256];	/*I/O buffer..			*/
+    const uint8		*p = NULL;	/*        ..and pointer into it */
+    size_t		fixed_size = 24; /*size of fixed part of boot blk*/
+    size_t		variable_size;	/*variable part of boot block	*/
+    H5F_create_t	*cp = NULL;	/*file creation parameters	*/
+    haddr_t		addr1, addr2;	/*temporary address		*/
+    H5G_entry_t		root_ent;	/*root symbol table entry	*/
+    const H5F_low_class_t *type = NULL;	/*low-level file driver		*/
 
     FUNC_ENTER(H5F_open, NULL);
 
     assert(name && *name);
 
     /*
-     * Does the name look like a family name?  A family name always has a
-     * percent (not preceded by a percent) followed by an optional plus and/or
-     * minus, followed by optional digits, followed by the letter `d', `u',
-     * `x', or `X'. This is a printf() format for an integer.
-     */
-    while (*s) {
-        if ('%' != *s++)
-            continue;
-        if ('%' == *s) {
-            s++;
-            continue;
-        }
-        while (*s && isdigit(*s))
-            s++;
-        if ('d' != *s && 'u' != *s && 'x' != *s && 'X' != *s)
-            continue;
-        break;
-    }
-    if (*s) {
-#ifdef H5F_DEBUG
-        if (type != H5F_LOW_FAM) {
-            fprintf(stderr, "HDF5-DIAG: opening a file family\n");
-        }
-#endif
-        type = H5F_LOW_FAM;
-    } else if (type == H5F_LOW_FAM) {
-        HRETURN_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
-                      "invalid file family name");
-    }
-    /*
-     * If the name ends with `.h5' and there's another file that ends with
-     * `.raw' then open the file as a split file.
-     */
-    {
-        if (H5F_LOW_SPLIT != type && (s = strstr(name, ".h5")) && !s[3]) {
-            char                    fullname[4096];
-            strncpy(fullname, name, s - name);
-            strcpy(fullname + (s - name), ".raw");
-            if (H5F_low_access(H5F_LOW_DFLT, fullname, F_OK, NULL)) {
-#ifdef H5F_DEBUG
-                fprintf(stderr, "HDF5-DIAG: opening a split file\n");
-#endif
-                fullname[s - name] = '\0';
-                f = H5F_open(H5F_LOW_SPLIT, fullname, flags, create_parms, access_parms);
-                HRETURN(f);
-            }
-        }
-    }
-
-    /*
-     * If no file creation parameters are supplied then use defaults.
+     * If no file creation parameters or file access parameters are supplied
+     * then use defaults.
      */
-    if (!create_parms)
-        create_parms = &H5F_create_dflt;
+    if (!create_parms) create_parms = &H5F_create_dflt;
+    if (!access_parms) access_parms = &H5F_access_dflt;
 
     /*
      * Does the file exist?  If so, get the device and i-node values so we can
@@ -659,112 +685,119 @@ H5F_open(const H5F_low_class_t *type, const char *name, uintn flags,
      * with hard or soft links) it doesn't work to compare files based only on
      * their full path name.
      */
-    file_exists = H5F_low_access(type, name, F_OK, &search);
+    type = H5F_low_class (access_parms->driver);
+    assert (type);
+    file_exists = H5F_low_access(type, name, access_parms, F_OK, &search);
 
     /*
      * Open the low-level file (if necessary) and create an H5F_t struct that
      * points to an H5F_file_t struct.
      */
     if (file_exists) {
-        if (flags & H5F_ACC_EXCL) {
-            HRETURN_ERROR(H5E_FILE, H5E_FILEEXISTS, NULL,
-                          "file already exists - CREAT EXCL failed");
-        }
-        if (!H5F_low_access(type, name, R_OK, NULL)) {
-            HRETURN_ERROR(H5E_FILE, H5E_READERROR, NULL,
-                          "file is not readable");
-        }
-        if ((flags & H5F_ACC_WRITE) &&
-            !H5F_low_access(type, name, W_OK, NULL)) {
-            HRETURN_ERROR(H5E_FILE, H5E_WRITEERROR, NULL,
-                          "file is not writable");
-        }
-        if ((old = H5A_search(H5_FILE, H5F_compare_files, &search))) {
-            if (flags & H5F_ACC_TRUNC) {
-                HRETURN_ERROR(H5E_FILE, H5E_FILEOPEN, NULL,
-                              "file already open - TRUNC failed");
-            }
-            if ((flags & H5F_ACC_WRITE) &&
-                0 == (old->shared->flags & H5F_ACC_WRITE)) {
-                if (NULL == (fd = H5F_low_open(type, name, H5F_ACC_WRITE, NULL))) {
-                    HRETURN_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
-                               "file cannot be reopened with write access");
-                }
-                H5F_low_close(old->shared->lf);
-                old->shared->lf = fd;
-                old->shared->flags |= H5F_ACC_WRITE;
-                fd = NULL;      /*so we don't close it during error */
-            }
-            f = H5F_new(old->shared);
-
-        } else if (flags & H5F_ACC_TRUNC) {
-            /* Truncate existing file */
-            if (0 == (flags & H5F_ACC_WRITE)) {
-                HRETURN_ERROR(H5E_FILE, H5E_BADVALUE, NULL,
-                              "can't truncate without write intent");
-            }
-            fd = H5F_low_open(type, name, H5F_ACC_WRITE | H5F_ACC_TRUNC, NULL);
-            if (!fd) {
-                HRETURN_ERROR(H5E_FILE, H5E_CANTCREATE, NULL,
-                              "can't truncate file");
-            }
-            f = H5F_new(NULL);
-            f->shared->key = search;
-            f->shared->flags = flags;
-            f->shared->lf = fd;
-            empty_file = TRUE;
-
-        } else {
-            fd = H5F_low_open(type, name, (flags & H5F_ACC_WRITE), NULL);
-            if (!fd) {
-                HRETURN_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
-                              "cannot open existing file");
-            }
-            f = H5F_new(NULL);
-            f->shared->key = search;
-            f->shared->flags = flags;
-            f->shared->lf = fd;
-        }
+	if (flags & H5F_ACC_EXCL) {
+	    HRETURN_ERROR(H5E_FILE, H5E_FILEEXISTS, NULL,
+			  "file already exists - CREAT EXCL failed");
+	}
+	if (!H5F_low_access(type, name, access_parms, R_OK, NULL)) {
+	    HRETURN_ERROR(H5E_FILE, H5E_READERROR, NULL,
+			  "file is not readable");
+	}
+	if ((flags & H5F_ACC_RDWR) &&
+	    !H5F_low_access(type, name, access_parms, W_OK, NULL)) {
+	    HRETURN_ERROR(H5E_FILE, H5E_WRITEERROR, NULL,
+			  "file is not writable");
+	}
+	if ((old = H5A_search(H5_FILE, H5F_compare_files, &search))) {
+	    if (flags & H5F_ACC_TRUNC) {
+		HRETURN_ERROR(H5E_FILE, H5E_FILEOPEN, NULL,
+			      "file already open - TRUNC failed");
+	    }
+	    if ((flags & H5F_ACC_RDWR) &&
+		0 == (old->shared->flags & H5F_ACC_RDWR)) {
+		if (NULL==(fd=H5F_low_open(type, name, access_parms,
+					   H5F_ACC_RDWR, NULL))) {
+		    HRETURN_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
+				  "file cannot be reopened with write access");
+		}
+		H5F_low_close(old->shared->lf, access_parms);
+		old->shared->lf = fd;
+		old->shared->flags |= H5F_ACC_RDWR;
+		fd = NULL;	/*so we don't close it during error */
+	    }
+	    f = H5F_new(old->shared);
+
+	} else if (flags & H5F_ACC_TRUNC) {
+	    /* Truncate existing file */
+	    if (0 == (flags & H5F_ACC_RDWR)) {
+		HRETURN_ERROR(H5E_FILE, H5E_BADVALUE, NULL,
+			      "can't truncate without write intent");
+	    }
+	    fd = H5F_low_open(type, name, access_parms,
+			      H5F_ACC_RDWR | H5F_ACC_TRUNC, NULL);
+	    if (!fd) {
+		HRETURN_ERROR(H5E_FILE, H5E_CANTCREATE, NULL,
+			      "can't truncate file");
+	    }
+	    f = H5F_new(NULL);
+	    f->shared->key = search;
+	    f->shared->flags = flags;
+	    f->shared->lf = fd;
+	    empty_file = TRUE;
+
+	} else {
+	    fd = H5F_low_open(type, name, access_parms,
+			      (flags & H5F_ACC_RDWR), NULL);
+	    if (!fd) {
+		HRETURN_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
+			      "cannot open existing file");
+	    }
+	    f = H5F_new(NULL);
+	    f->shared->key = search;
+	    f->shared->flags = flags;
+	    f->shared->lf = fd;
+	}
 
     } else if (flags & H5F_ACC_CREAT) {
-        if (0 == (flags & H5F_ACC_WRITE)) {
-            HRETURN_ERROR(H5E_FILE, H5E_BADVALUE, NULL,
-                          "can't create file without write intent");
-        }
+	if (0 == (flags & H5F_ACC_RDWR)) {
+	    HRETURN_ERROR(H5E_FILE, H5E_BADVALUE, NULL,
+			  "can't create file without write intent");
+	}
 #ifdef HAVE_PARALLEL
-	/* ROMIO cannot handle file-open with EXCL Create due to racing problem */
-	/* The first process creates the file which then fails all */
-	/* other processes.  Turn on TRUNC bit here.  It does not matter */
-	/* since the file does not exist at this point. */
-        fd = H5F_low_open(type, name,
-                          H5F_ACC_WRITE | H5F_ACC_CREAT |
+	/*
+	 * ROMIO cannot handle file-open with EXCL Create due to racing
+	 * problem.  The first process creates the file which then fails all
+	 * other processes.  Turn on TRUNC bit here.  It does not matter since
+	 * the file does not exist at this point.
+	 */
+	fd = H5F_low_open(type, name, access_parms,
+			  H5F_ACC_RDWR | H5F_ACC_CREAT |
 			  (flags & H5F_ACC_TRUNC),
-                          &search);
+			  &search);
 #else
-        fd = H5F_low_open(type, name,
-                          H5F_ACC_WRITE | H5F_ACC_CREAT |
+	fd = H5F_low_open(type, name, access_parms,
+			  H5F_ACC_RDWR | H5F_ACC_CREAT |
 			  (flags & H5F_ACC_EXCL) | (flags & H5F_ACC_TRUNC),
-                          &search);
+			  &search);
 #endif /*HAVE_PARALLEL*/
-        if (!fd) {
-            HRETURN_ERROR(H5E_FILE, H5E_CANTCREATE, NULL,
-                          "can't create file");
-        }
-        f = H5F_new(NULL);
-        f->shared->key = search;
-        f->shared->flags = flags;
-        f->shared->lf = fd;
-        empty_file = TRUE;
+	if (!fd) {
+	    HRETURN_ERROR(H5E_FILE, H5E_CANTCREATE, NULL,
+			  "can't create file");
+	}
+	f = H5F_new(NULL);
+	f->shared->key = search;
+	f->shared->flags = flags;
+	f->shared->lf = fd;
+	empty_file = TRUE;
 
     } else {
-        HRETURN_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
-                      "file does not exist");
+	HRETURN_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
+		      "file does not exist");
     }
     assert(f);
 
     /*
      * The intent at the top level file struct are not necessarily the same as
-     * the flags at the bottom.  The top level describes how the file can be
+     * the flags at the bottom.	 The top level describes how the file can be
      * accessed through the HDF5 library.  The bottom level describes how the
      * file can be accessed through the C library.
      */
@@ -772,11 +805,12 @@ H5F_open(const H5F_low_class_t *type, const char *name, uintn flags,
     f->name = H5MM_xstrdup(name);
 
     /*
-     * Update the file creation parameters with default values if this is the
-     * first time this file is opened.
+     * Update the file creation parameters and file access parameters with
+     * default values if this is the first time this file is opened.
      */
     if (1 == f->shared->nrefs) {
-        f->shared->create_parms = *create_parms;
+	f->shared->create_parms = *create_parms;
+	f->shared->access_parms = *access_parms;
     }
     cp = &(f->shared->create_parms);
 
@@ -784,131 +818,140 @@ H5F_open(const H5F_low_class_t *type, const char *name, uintn flags,
      * Read or write the file boot block.
      */
     if (empty_file) {
-        /*
-         * For new files we must write the boot block.  The boot block starts
-         * immediately after the user-defined header, which we have already
-         * insured is a proper size.  The base address is set to the same thing
-         * as the boot block.
-         */
-        H5F_addr_reset(&(f->shared->boot_addr));
-        H5F_addr_inc(&(f->shared->boot_addr),
-                     f->shared->create_parms.userblock_size);
-        f->shared->base_addr = f->shared->boot_addr;
-
-        f->shared->consist_flags = 0x03;
-        if (H5F_flush(f, FALSE) < 0) {
-            HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, NULL,
-                        "can't write file boot block");
-        }
+	/*
+	 * For new files we must write the boot block.	The boot block starts
+	 * immediately after the user-defined header, which we have already
+	 * insured is a proper size.  The base address is set to the same thing
+	 * as the boot block.
+	 */
+	H5F_addr_reset(&(f->shared->boot_addr));
+	H5F_addr_inc(&(f->shared->boot_addr),
+		     f->shared->create_parms.userblock_size);
+	f->shared->base_addr = f->shared->boot_addr;
+
+	f->shared->consist_flags = 0x03;
+	if (H5F_flush(f, FALSE) < 0) {
+	    HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, NULL,
+			"can't write file boot block");
+	}
+	
     } else if (1 == f->shared->nrefs) {
-        /* For existing files we must read the boot block. */
-        if (H5F_locate_signature(f->shared->lf, &(f->shared->boot_addr)) < 0) {
-            HGOTO_ERROR(H5E_FILE, H5E_NOTHDF5, NULL, "can't find signature");
-        }
-        if (H5F_low_read(f->shared->lf, &(f->shared->boot_addr),
-                         fixed_size, buf) < 0) {
-            HGOTO_ERROR(H5E_IO, H5E_READERROR, NULL, "can't read boot block");
-        }
-        /*
-         * Decode the fixed size part of the boot block.  For each of the
-         * version parameters, check that the library is able to handle that
-         * version.
-         */
-        p = buf + H5F_SIGNATURE_LEN;    /*already checked */
-
-        cp->bootblock_ver = *p++;
-        if (cp->bootblock_ver != HDF5_BOOTBLOCK_VERSION) {
-            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
-                        "bad boot block version number");
-        }
-        cp->smallobject_ver = *p++;
-        if (cp->smallobject_ver != HDF5_SMALLOBJECT_VERSION) {
-            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
-                        "bad small object heap version number");
-        }
-        cp->freespace_ver = *p++;
-        if (cp->freespace_ver != HDF5_FREESPACE_VERSION) {
-            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
-                        "bad free space version number");
-        }
-        cp->objectdir_ver = *p++;
-        if (cp->objectdir_ver != HDF5_OBJECTDIR_VERSION) {
-            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
-                        "bad object dir version number");
-        }
-        cp->sharedheader_ver = *p++;
-        if (cp->sharedheader_ver != HDF5_SHAREDHEADER_VERSION) {
-            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
-                        "bad shared header version number");
-        }
-        cp->sizeof_addr = *p++;
-        if (cp->sizeof_addr != 2 &&
-            cp->sizeof_addr != 4 &&
-            cp->sizeof_addr != 8 &&
-            cp->sizeof_addr != 16 &&
-            cp->sizeof_addr != 32) {
-            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
-                        "bad address size");
-        }
-        cp->sizeof_size = *p++;
-        if (cp->sizeof_size != 2 &&
-            cp->sizeof_size != 4 &&
-            cp->sizeof_size != 8 &&
-            cp->sizeof_size != 16 &&
-            cp->sizeof_size != 32) {
-            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
-                        "bad length size");
-        }
-        /* Reserved byte */
-        p++;
-
-        UINT16DECODE(p, cp->sym_leaf_k);
-        if (cp->sym_leaf_k < 1) {
-            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
-                        "bad symbol table leaf node 1/2 rank");
-        }
-        UINT16DECODE(p, cp->btree_k[H5B_SNODE_ID]);
-        if (cp->btree_k[H5B_SNODE_ID] < 1) {
-            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
-                        "bad symbol table internal node 1/2 rank");
-        }
-        UINT32DECODE(p, f->shared->consist_flags);
-        /* nothing to check for consistency flags */
-
-        assert(p - buf == fixed_size);
-
-        /* Read the variable length part of the boot block... */
-        variable_size = H5F_SIZEOF_ADDR(f) +    /*base address */
-            H5F_SIZEOF_ADDR(f) +        /*global small obj heap */
-            H5F_SIZEOF_ADDR(f) +        /*global free list addr */
-            H5F_SIZEOF_ADDR(f) +        /*logical file size */
-            H5G_SIZEOF_ENTRY(f);
-        assert(variable_size <= sizeof buf);
-        addr1 = f->shared->boot_addr;
-        H5F_addr_inc(&addr1, fixed_size);
-        if (H5F_low_read(f->shared->lf, &addr1, variable_size, buf) < 0) {
-            HGOTO_ERROR(H5E_FILE, H5E_NOTHDF5, NULL,
-                        "can't read boot block");
-        }
-        p = buf;
-        H5F_addr_decode(f, &p, &(f->shared->base_addr));
-        H5F_addr_decode(f, &p, &(f->shared->smallobj_addr));
-        H5F_addr_decode(f, &p, &(f->shared->freespace_addr));
-        H5F_addr_decode(f, &p, &(f->shared->hdf5_eof));
-        if (H5G_ent_decode(f, &p, &root_ent) < 0) {
-            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
-                        "can't read root symbol entry");
-        }
-        if (H5F_addr_defined(&(root_ent.header))) {
-            f->shared->root_ent = H5MM_xmalloc(sizeof(H5G_entry_t));
-            *(f->shared->root_ent) = root_ent;
-        }
-        /*
-         * The userdefined data is the area of the file before the base
-         * address.
-         */
-        f->shared->create_parms.userblock_size = f->shared->base_addr.offset;
+	/* For existing files we must read the boot block. */
+	if (H5F_locate_signature(f->shared->lf,
+				 &(f->shared->access_parms),
+				 &(f->shared->boot_addr)) < 0) {
+	    HGOTO_ERROR(H5E_FILE, H5E_NOTHDF5, NULL, "can't find signature");
+	}
+	if (H5F_low_read(f->shared->lf, access_parms, &(f->shared->boot_addr),
+			 fixed_size, buf) < 0) {
+	    HGOTO_ERROR(H5E_IO, H5E_READERROR, NULL, "can't read boot block");
+	}
+	
+	/*
+	 * Decode the fixed size part of the boot block.  For each of the
+	 * version parameters, check that the library is able to handle that
+	 * version.
+	 */
+	p = buf + H5F_SIGNATURE_LEN;	/*already checked */
+
+	cp->bootblock_ver = *p++;
+	if (cp->bootblock_ver != HDF5_BOOTBLOCK_VERSION) {
+	    HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
+			"bad boot block version number");
+	}
+	cp->smallobject_ver = *p++;
+	if (cp->smallobject_ver != HDF5_SMALLOBJECT_VERSION) {
+	    HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
+			"bad small object heap version number");
+	}
+	cp->freespace_ver = *p++;
+	if (cp->freespace_ver != HDF5_FREESPACE_VERSION) {
+	    HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
+			"bad free space version number");
+	}
+	cp->objectdir_ver = *p++;
+	if (cp->objectdir_ver != HDF5_OBJECTDIR_VERSION) {
+	    HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
+			"bad object dir version number");
+	}
+	cp->sharedheader_ver = *p++;
+	if (cp->sharedheader_ver != HDF5_SHAREDHEADER_VERSION) {
+	    HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
+			"bad shared header version number");
+	}
+	cp->sizeof_addr = *p++;
+	if (cp->sizeof_addr != 2 &&
+	    cp->sizeof_addr != 4 &&
+	    cp->sizeof_addr != 8 &&
+	    cp->sizeof_addr != 16 &&
+	    cp->sizeof_addr != 32) {
+	    HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
+			"bad address size");
+	}
+	cp->sizeof_size = *p++;
+	if (cp->sizeof_size != 2 &&
+	    cp->sizeof_size != 4 &&
+	    cp->sizeof_size != 8 &&
+	    cp->sizeof_size != 16 &&
+	    cp->sizeof_size != 32) {
+	    HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
+			"bad length size");
+	}
+	
+	/* Reserved byte */
+	p++;
+
+	UINT16DECODE(p, cp->sym_leaf_k);
+	if (cp->sym_leaf_k < 1) {
+	    HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
+			"bad symbol table leaf node 1/2 rank");
+	}
+	UINT16DECODE(p, cp->btree_k[H5B_SNODE_ID]);
+	if (cp->btree_k[H5B_SNODE_ID] < 1) {
+	    HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
+			"bad symbol table internal node 1/2 rank");
+	}
+	UINT32DECODE(p, f->shared->consist_flags);
+	
+	/* nothing to check for consistency flags */
+
+	assert(p - buf == fixed_size);
+
+	/* Read the variable length part of the boot block... */
+	variable_size = H5F_SIZEOF_ADDR(f) +	/*base address */
+			H5F_SIZEOF_ADDR(f) +	/*global small obj heap */
+			H5F_SIZEOF_ADDR(f) +	/*global free list addr */
+			H5F_SIZEOF_ADDR(f) +	/*logical file size */
+			H5G_SIZEOF_ENTRY(f);
+	assert(variable_size <= sizeof buf);
+	addr1 = f->shared->boot_addr;
+	H5F_addr_inc(&addr1, fixed_size);
+	if (H5F_low_read(f->shared->lf, access_parms, &addr1, variable_size,
+			 buf) < 0) {
+	    HGOTO_ERROR(H5E_FILE, H5E_NOTHDF5, NULL,
+			"can't read boot block");
+	}
+	p = buf;
+	H5F_addr_decode(f, &p, &(f->shared->base_addr));
+	H5F_addr_decode(f, &p, &(f->shared->smallobj_addr));
+	H5F_addr_decode(f, &p, &(f->shared->freespace_addr));
+	H5F_addr_decode(f, &p, &(f->shared->hdf5_eof));
+	if (H5G_ent_decode(f, &p, &root_ent) < 0) {
+	    HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL,
+			"can't read root symbol entry");
+	}
+	if (H5F_addr_defined(&(root_ent.header))) {
+	    f->shared->root_ent = H5MM_xmalloc(sizeof(H5G_entry_t));
+	    *(f->shared->root_ent) = root_ent;
+	}
+	
+	/*
+	 * The userdefined data is the area of the file before the base
+	 * address.
+	 */
+	f->shared->create_parms.userblock_size = f->shared->base_addr.offset;
     }
+    
     /*
      * What is the current size of the file? The max_addr field is a relative
      * address while H5F_low_size() returns an absolute address.
@@ -917,265 +960,243 @@ H5F_open(const H5F_low_class_t *type, const char *name, uintn flags,
     addr2 = f->shared->hdf5_eof;
     H5F_addr_add(&addr2, &(f->shared->base_addr));
     if (H5F_addr_lt(&addr1, &addr2)) {
-        /*
-         * Truncated file? This might happen if one tries to open the first
-         * member of a file family.
-         */
-        HGOTO_ERROR(H5E_FILE, H5E_TRUNCATED, NULL, "truncated file");
+	/*
+	 * Truncated file? This might happen if one tries to open the first
+	 * member of a file family.
+	 */
+	HGOTO_ERROR(H5E_FILE, H5E_TRUNCATED, NULL, "truncated file");
+	
     } else if (H5F_addr_gt(&addr1, &addr2)) {
-        /*
-         * The file is larger than the hdf5 data.  It either has extra junk at
-         * the end, or a wrapper.  In either case, make the file think it's
-         * shorter so when we allocate memory from the file for hdf5 it's
-         * allocated immediately after the end of the previous hdf5 data.  This
-         * will cause internal wrappers to be overwritten if they follow the
-         * hdf5 data.
-         */
+	/*
+	 * The file is larger than the hdf5 data.  It either has extra junk at
+	 * the end, or a wrapper.  In either case, make the file think it's
+	 * shorter so when we allocate memory from the file for hdf5 it's
+	 * allocated immediately after the end of the previous hdf5 data.  This
+	 * will cause internal wrappers to be overwritten if they follow the
+	 * hdf5 data.
+	 */
 #ifdef H5F_DEBUG
-        fprintf(stderr, "HDF5-DIAG: resetting EOF from ");
-        H5F_addr_print(stderr, &addr1);
-        fprintf(stderr, " to ");
-        H5F_addr_print(stderr, &addr2);
-        fprintf(stderr, " (abs)\n");
+	fprintf(stderr, "HDF5-DIAG: resetting EOF from ");
+	H5F_addr_print(stderr, &addr1);
+	fprintf(stderr, " to ");
+	H5F_addr_print(stderr, &addr2);
+	fprintf(stderr, " (abs)\n");
 #endif
-        H5F_low_seteof(f->shared->lf, &addr2);
+	H5F_low_seteof(f->shared->lf, &addr2);
     }
+    
     /* Success! */
     ret_value = f;
 
   done:
     if (!ret_value) {
-        if (f)
-            H5F_dest(f);
-        H5F_low_close(fd);
+	if (f) H5F_dest(f);
+	H5F_low_close(fd, access_parms);
     }
     FUNC_LEAVE(ret_value);
 }
 
 
-/*--------------------------------------------------------------------------
- NAME
-    H5Fcreate
-
- PURPOSE
-    Create a new HDF5 file.
-
- USAGE
-    int32 H5Fcreate(filename, flags, create_temp, access_temp)
-        const char *filename;   IN: Name of the file to create
-        uintn flags;            IN: Flags to indicate various options.
-        hid_t create_temp;    IN: File-creation template ID
-        hid_t access_temp;    IN: File-access template ID
-
- ERRORS
-    ARGS      BADVALUE      Invalid file name. 
-    ARGS      BADVALUE      Invalid flags. 
-    ATOM      BADATOM       Can't unatomize template. 
-    ATOM      CANTREGISTER  Can't atomize file. 
-    FILE      CANTOPENFILE  Can't create file. 
-
- RETURNS
-    Returns file ID on success, FAIL on failure
-
- DESCRIPTION
-        This is the primary function for creating HDF5 files . The flags
-    parameter determines whether an existing file will be overwritten or not.
-    All newly created files are opened for both reading and writing.  All flags
-    may be combined with the "||" (logical OR operator) to change the behavior
-    of the file open call.
-        The flags currently defined:
-            H5ACC_OVERWRITE - Truncate file, if it already exists. The file
-                will be truncated, erasing all data previously stored in the
-                file.
-        The more complex behaviors of a file's creation and access are
-    controlled through the file-creation and file-access templates.  The value
-    of 0 for a template value indicates that the library should use the default
-    values for the appropriate template.  (Documented in the template module).
-    [Access templates are currently unused in this routine, although they will
-    be implemented in the future]
-
- MODIFICATIONS:
-    Robb Matzke, 18 Jul 1997
-    File struct creation and destruction is through H5F_new() H5F_dest().
-    Writing the root symbol table entry is done with H5G_encode().
-
-    Robb Matzke, 29 Aug 1997
-    Moved creation of the boot block to H5F_flush().
- 
-    Robb Matzke, 23 Sep 1997
-    Most of the work is now done by H5F_open() since H5Fcreate() and H5Fopen()
-    originally contained almost identical code.
---------------------------------------------------------------------------*/
+/*-------------------------------------------------------------------------
+ * Function:	H5Fcreate
+ *
+ * Purpose:	This is the primary function for creating HDF5 files . The
+ *		flags parameter determines whether an existing file will be
+ *		overwritten or not.  All newly created files are opened for
+ *		both reading and writing.  All flags may be combined with the
+ *		bit-wise OR operator (`|') to change the behavior of the file
+ *		create call.
+ *
+ *		The more complex behaviors of a file's creation and access
+ *		are controlled through the file-creation and file-access
+ *		property lists.  The value of H5C_DEFAULT for a template
+ *		value indicates that the library should use the default
+ *		values for the appropriate template.
+ *
+ * See also:	H5Fpublic.h for the list of supported flags. H5Cpublic.h for
+ * 		the list of file creation and file access properties.
+ *
+ * Return:	Success:	A file ID
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Unknown
+ *
+ * Modifications:
+ * 
+ * 	Robb Matzke, 18 Jul 1997
+ *	File struct creation and destruction is through H5F_new() H5F_dest().
+ *	Writing the root symbol table entry is done with H5G_encode().
+ *	
+ *  	Robb Matzke, 29 Aug 1997
+ *	Moved creation of the boot block to H5F_flush().
+ *	
+ *  	Robb Matzke, 23 Sep 1997
+ *	Most of the work is now done by H5F_open() since H5Fcreate() and
+ *	H5Fopen() originally contained almost identical code.
+ *
+ * 	Robb Matzke, 18 Feb 1998
+ *	Better error checking for the creation and access property lists. It
+ *	used to be possible to swap the two and core the library.  Also, zero
+ *	is no longer valid as a default property list; one must use
+ *	H5C_DEFAULT instead.
+ *
+ *-------------------------------------------------------------------------
+ */
 hid_t 
-H5Fcreate(const char *filename, uintn flags, hid_t create_temp,
-          hid_t access_temp)
+H5Fcreate(const char *filename, uintn flags, hid_t create_id,
+	  hid_t access_id)
 {
-    H5F_t                  *new_file = NULL;    /* file struct for new file */
-    const H5F_create_t     *create_parms;       /* pointer to the parameters to
-                                                   * use when creating the file
-                                                 */
-    const H5F_access_t     *access_parms;       /* pointer to the file access
-    						 * parameters to use when creating
-						 * the file
-                                                 */
-    const H5F_low_class_t        *type;		/* File type */
-    hid_t                   ret_value = FAIL;
+    
+    H5F_t		*new_file = NULL;	/* file struct for new file */
+    const H5F_create_t	*create_parms;		/* pointer to the parameters to
+						 * use when creating the file
+						 */
+    const H5F_access_t	*access_parms;		/* pointer to the file access
+						 * parameters to use when
+						 * creating the file
+						 */
+    hid_t		  ret_value = FAIL;
 
     FUNC_ENTER(H5Fcreate, FAIL);
 
     /* Check/fix arguments */
-    if (!filename || !*filename)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid file name");
-    if (flags & ~H5ACC_OVERWRITE)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid flags");
-    flags = (H5F_ACC_WRITE | H5F_ACC_CREAT) |
-        (H5ACC_OVERWRITE == flags ? H5F_ACC_TRUNC : H5F_ACC_EXCL);
-
-    if (create_temp <= 0) {
-        create_parms = &H5F_create_dflt;
-    } else if (NULL == (create_parms = H5A_object(create_temp))) {
-        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't unatomize template");
+    if (!filename || !*filename) {
+	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid file name");
     }
-    if (access_temp <= 0) {
-        access_parms = &H5F_access_dflt;
-    } else if (NULL == (access_parms = H5A_object(access_temp))) {
-        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't unatomize template");
+    if (flags & ~(H5F_ACC_EXCL|H5F_ACC_TRUNC)) {
+	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid flags");
     }
-    /* figure out what kind of file I/O to use. */
-    /* Currently, MPIO is the only alternative than default I/O */
-    switch (access_parms->access_mode){
-    case H5ACC_DEFAULT:
-	type = H5F_LOW_DFLT;
-	break;
-#ifdef HAVE_PARALLEL
-    case H5ACC_INDEPENDENT:
-	type = H5F_LOW_MPIO;
-	break;
-    case H5ACC_COLLECTIVE:
-	/* not implemented yet */
-	/* type = H5F_LOW_MPIO; */
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "Invalid file access mode");
-#endif
-    default:
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "Invalid file access mode");
+    if ((flags & H5F_ACC_EXCL) && (flags & H5F_ACC_EXCL)) {
+	HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL,
+		     "mutually exclusive flags for file creation");
     }
-	
+    if (H5C_DEFAULT==create_id) {
+	create_parms = &H5F_create_dflt;
+    } else if (H5C_FILE_CREATE!=H5Cget_class (create_id) ||
+	       NULL == (create_parms = H5A_object(create_id))) {
+	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
+		    "not a file creation property list");
+    }
+    if (H5C_DEFAULT==access_id) {
+	access_parms = &H5F_access_dflt;
+    } else if (H5C_FILE_ACCESS!=H5Cget_class (access_id) ||
+	       NULL == (access_parms = H5A_object(access_id))) {
+	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
+		    "not a file access property list");
+    }
+
+    /*
+     * Adjust bit flags by turning on the creation bit and making sure that
+     * the EXCL or TRUNC bit is set.  All newly-created files are opened for
+     * reading and writing.
+     */
+    if (0==(flags & (H5F_ACC_EXCL|H5F_ACC_TRUNC))) {
+	flags |= H5F_ACC_EXCL;	 /*default*/
+    }
+    flags |= H5F_ACC_RDWR | H5F_ACC_CREAT;
+
     /*
      * Create a new file or truncate an existing file.
      */
-    if (NULL == (new_file = H5F_open(type, filename, flags,
-                                     create_parms, access_parms))) {
-        HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "can't create file");
+    if (NULL == (new_file = H5F_open(filename, flags, create_parms,
+				     access_parms))) {
+	HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "unable to create file");
     }
+    
     /* Get an atom for the file */
-    if ((ret_value = H5A_register(H5_FILE, new_file)) < 0)
-        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "can't atomize file");
+    if ((ret_value = H5A_register(H5_FILE, new_file)) < 0) {
+	HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL,
+		    "unable to atomize file");
+    }
 
   done:
     if (ret_value < 0 && new_file) {
-        /* Error condition cleanup */
-        H5F_close(new_file);
+	/* Error condition cleanup */
+	H5F_close(new_file);
     }
-    /* Normal function cleanup */
 
     FUNC_LEAVE(ret_value);
 }
 
 
-/*--------------------------------------------------------------------------
- NAME
-    H5Fopen
-
- PURPOSE
-    Open an existing HDF5 file.
-
- USAGE
-    hid_t H5Fopen(filename, flags, access_temp)
-        const char *filename;   IN: Name of the file to create
-        uintn flags;            IN: Flags to indicate various options.
-        hid_t access_temp;    IN: File-access template
-
- ERRORS
-    ARGS      BADRANGE      Invalid file name. 
-    ATOM      BADATOM       Can't unatomize template. 
-    ATOM      CANTREGISTER  Can't atomize file. 
-    FILE      CANTOPENFILE  Cant open file. 
-
- RETURNS
-    Returns file ID on success, FAIL on failure
-
- DESCRIPTION
-        This is the primary function for accessing existing HDF5 files. The
-    flags parameter determines whether writing to an existing file will be
-    allowed or not.  All flags may be combined with the "||" (logical OR
-    operator) to change the behavior of the file open call.
-        The flags currently defined:
-            H5ACC_WRITE - Allow writing to the file.
-        The more complex behaviors of a file's access are controlled through
-    the file-access template.
-
- MODIFICATIONS:
-    Robb Matzke, 18 Jul 1997
-    File struct creation and destruction is through H5F_new() H5F_dest().
-    Reading the root symbol table entry is done with H5G_decode().
-
-    Robb Matzke, 23 Sep 1997
-    Most of the work is now done by H5F_open() since H5Fcreate() and H5Fopen()
-    originally contained almost identical code.
---------------------------------------------------------------------------*/
+/*-------------------------------------------------------------------------
+ * Function:	H5Fopen
+ *
+ * Purpose:	This is the primary function for accessing existing HDF5
+ *		files.  The FLAGS argument determines whether writing to an
+ *		existing file will be allowed or not.  All flags may be
+ *		combined with the bit-wise OR operator (`|') to change the
+ *		behavior of the file open call.  The more complex behaviors
+ *		of a file's access are controlled through the file-access
+ *		property list.
+ *
+ * See Also:	H5Fpublic.h for a list of possible values for FLAGS.
+ *
+ * Return:	Success:	A file ID
+ *
+ *		Failure:	FAIL
+ *
+ * Programmer:	Unknown
+ *
+ * Modifications:
+ * 
+ *  	Robb Matzke, 18 Jul 1997
+ *	File struct creation and destruction is through H5F_new() H5F_dest().
+ *	Reading the root symbol table entry is done with H5G_decode().
+ *	
+ *  	Robb Matzke, 23 Sep 1997
+ *	Most of the work is now done by H5F_open() since H5Fcreate() and
+ *	H5Fopen() originally contained almost identical code.
+ *
+ * 	Robb Matzke, 18 Feb 1998
+ *	Added better error checking for the flags and the file access
+ *	property list.  It used to be possible to make the library dump core
+ *	by passing an object ID that was not a file access property list.
+ *
+ *-------------------------------------------------------------------------
+ */
 hid_t 
-H5Fopen(const char *filename, uintn flags, hid_t access_temp)
+H5Fopen(const char *filename, uintn flags, hid_t access_id)
 {
-    H5F_t                  *new_file = NULL;    /* file struct for new file */
-    const H5F_access_t     *access_parms;       /* pointer to the file access
-    						 * parameters to use when creating
-						 * the file
-                                                 */
-    const H5F_low_class_t        *type;		/* File type */
-    hid_t                   ret_value = FAIL;
+    H5F_t		*new_file = NULL;	/* file struct for new file */
+    const H5F_access_t	*access_parms;		/* pointer to the file access
+						 * parameters to use when
+						 * creating the file
+						 */
+    hid_t		  ret_value = FAIL;
 
     FUNC_ENTER(H5Fopen, FAIL);
 
     /* Check/fix arguments. */
-    if (!filename || !*filename)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADRANGE, FAIL, "invalid file name");
-    flags = flags & H5ACC_WRITE ? H5F_ACC_WRITE : 0;
-
-    if (access_temp <= 0) {
-        access_parms = &H5F_access_dflt;
-    } else if (NULL == (access_parms = H5A_object(access_temp))) {
-        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't unatomize template");
+    if (!filename || !*filename) {
+	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid file name");
     }
-    /* figure out what kind of file I/O to use. */
-    /* Currently, MPIO is the only alternative than default I/O */
-    switch (access_parms->access_mode){
-    case H5ACC_DEFAULT:
-	type = H5F_LOW_DFLT;
-	break;
-#ifdef HAVE_PARALLEL
-    case H5ACC_INDEPENDENT:
-	type = H5F_LOW_MPIO;
-	break;
-    case H5ACC_COLLECTIVE:
-	/* not implemented yet */
-	/* type = H5F_LOW_MPIO; */
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "Invalid file access mode");
-#endif
-    default:
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "Invalid file access mode");
+    if ((flags & ~H5F_ACC_PUBLIC_FLAGS) ||
+	(flags & H5F_ACC_TRUNC) || (flags & H5F_ACC_EXCL)) {
+	HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL, "invalid file open flags");
+    }
+    if (H5C_DEFAULT==access_id) {
+	access_parms = &H5F_access_dflt;
+    } else if (H5C_FILE_ACCESS!=H5Cget_class (access_id) ||
+	       NULL == (access_parms = H5A_object(access_id))) {
+	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL,
+		    "not a file access property list");
     }
 
     /* Open the file */
-    if (NULL == (new_file = H5F_open(type, filename, flags, NULL, access_parms))) {
-        HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "cant open file");
+    if (NULL==(new_file=H5F_open(filename, flags, NULL, access_parms))) {
+	HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "cant open file");
     }
+
     /* Get an atom for the file */
-    if ((ret_value = H5A_register(H5_FILE, new_file)) < 0)
-        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "can't atomize file");
+    if ((ret_value = H5A_register(H5_FILE, new_file)) < 0) {
+	HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "can't atomize file");
+    }
 
-  done:
+ done:
     if (ret_value < 0 && new_file) {
-        H5F_close(new_file);
+	H5F_close(new_file);
     }
     /* Normal function cleanup */
 
@@ -1183,23 +1204,23 @@ H5Fopen(const char *filename, uintn flags, hid_t access_temp)
 }
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_flush
+ * Function:	H5F_flush
  *
- * Purpose:     Flushes (and optionally invalidates) cached data plus the
- *              file boot block.  If the logical file size field is zero
- *              then it is updated to be the length of the boot block.
+ * Purpose:	Flushes (and optionally invalidates) cached data plus the
+ *		file boot block.  If the logical file size field is zero
+ *		then it is updated to be the length of the boot block.
  *
  * Errors:
- *              CACHE     CANTFLUSH     Can't flush cache. 
- *              IO        WRITEERROR    Can't write header. 
+ *		CACHE	  CANTFLUSH	Can't flush cache. 
+ *		IO	  WRITEERROR	Can't write header. 
  *
- * Return:      Success:        SUCCEED
+ * Return:	Success:	SUCCEED
  *
- *              Failure:        FAIL
+ *		Failure:	FAIL
  *
- * Programmer:  Robb Matzke
- *              matzke@llnl.gov
- *              Aug 29 1997
+ * Programmer:	Robb Matzke
+ *		matzke@llnl.gov
+ *		Aug 29 1997
  *
  * Modifications:
  *
@@ -1208,23 +1229,24 @@ H5Fopen(const char *filename, uintn flags, hid_t access_temp)
 static herr_t
 H5F_flush(H5F_t *f, hbool_t invalidate)
 {
-    uint8                   buf[2048], *p = buf;
+    uint8		    buf[2048], *p = buf;
 
     FUNC_ENTER(H5F_flush, FAIL);
 
     /*
-     * Nothing to do if the file is read only.  This determination is made at
+     * Nothing to do if the file is read only.	This determination is made at
      * the shared open(2) flags level, implying that opening a file twice,
      * once for read-only and once for read-write, and then calling
      * H5F_flush() with the read-only handle, still causes data to be flushed.
      */
-    if (0 == (H5F_ACC_WRITE & f->shared->flags))
-        HRETURN(SUCCEED);
+    if (0 == (H5F_ACC_RDWR & f->shared->flags))
+	HRETURN(SUCCEED);
 
     /* flush (and invalidate) the entire cache */
     if (H5AC_flush(f, NULL, 0, invalidate) < 0) {
-        HRETURN_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "can't flush cache");
+	HRETURN_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "can't flush cache");
     }
+
     /* encode the file boot block */
     HDmemcpy(p, H5F_SIGNATURE, H5F_SIGNATURE_LEN);
     p += H5F_SIGNATURE_LEN;
@@ -1238,7 +1260,7 @@ H5F_flush(H5F_t *f, hbool_t invalidate)
     *p++ = (uint8)H5F_SIZEOF_ADDR(f);
     assert (H5F_SIZEOF_SIZE(f)<=255);
     *p++ = (uint8)H5F_SIZEOF_SIZE(f);
-    *p++ = 0;                   /*reserved */
+    *p++ = 0;			/*reserved */
     UINT16ENCODE(p, f->shared->create_parms.sym_leaf_k);
     UINT16ENCODE(p, f->shared->create_parms.btree_k[H5B_SNODE_ID]);
     UINT32ENCODE(p, f->shared->consist_flags);
@@ -1250,32 +1272,35 @@ H5F_flush(H5F_t *f, hbool_t invalidate)
 
     /* update file length if necessary */
     if (!H5F_addr_defined(&(f->shared->hdf5_eof))) {
-        H5F_addr_reset(&(f->shared->hdf5_eof));
-        H5F_addr_inc(&(f->shared->hdf5_eof), p - buf);
-        H5F_low_seteof(f->shared->lf, &(f->shared->hdf5_eof));
+	H5F_addr_reset(&(f->shared->hdf5_eof));
+	H5F_addr_inc(&(f->shared->hdf5_eof), p - buf);
+	H5F_low_seteof(f->shared->lf, &(f->shared->hdf5_eof));
     }
+    
     /* write the boot block to disk */
-    if (H5F_low_write(f->shared->lf, &(f->shared->boot_addr), p - buf, buf) < 0) {
-        HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "can't write header");
+    if (H5F_low_write(f->shared->lf, &(f->shared->access_parms),
+		      &(f->shared->boot_addr), p-buf, buf)<0) {
+	HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "can't write header");
     }
+    
     /* Flush file buffers to disk */
-    if (H5F_low_flush(f->shared->lf) < 0) {
-        HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "low level flush failed");
+    if (H5F_low_flush(f->shared->lf, &(f->shared->access_parms)) < 0) {
+	HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "low level flush failed");
     }
     FUNC_LEAVE(SUCCEED);
 }
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_close
+ * Function:	H5F_close
  *
- * Purpose:     Closes an open HDF5 file.
+ * Purpose:	Closes an open HDF5 file.
  *
- * Return:      Success:        SUCCEED
+ * Return:	Success:	SUCCEED
  *
- *              Failure:        FAIL
+ *		Failure:	FAIL
  *
- * Programmer:  Robb Matzke
- *              Tuesday, September 23, 1997
+ * Programmer:	Robb Matzke
+ *		Tuesday, September 23, 1997
  *
  * Modifications:
  *
@@ -1287,13 +1312,13 @@ H5F_close(H5F_t *f)
     FUNC_ENTER(H5F_close, FAIL);
 
     /* Close all current working groups */
-    while (H5G_pop(f) >= 0)     /*void */
-        ;
+    while (H5G_pop(f) >= 0) /*void*/;
 
     /* Flush the boot block and caches */
     if (H5F_flush(f, TRUE) < 0) {
-        HRETURN_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "can't flush cache");
+	HRETURN_ERROR(H5E_CACHE, H5E_CANTFLUSH, FAIL, "can't flush cache");
     }
+    
     /*
      * If object headers are still open then delay deletion of resources until
      * they have all been closed.  The file is in a consistent state now, so
@@ -1301,25 +1326,25 @@ H5F_close(H5F_t *f)
      */
     if (f->nopen > 0) {
 #ifndef NDEBUG
-        fprintf(stderr, "HDF5-DIAG: H5F_close: %d object header%s still "
-                "open (file close will complete when %s closed)\n",
-                f->nopen,
-                1 == f->nopen ? " is" : "s are",
-                1 == f->nopen ? "that header is" : "those headers are");
+	fprintf(stderr, "HDF5-DIAG: H5F_close: %d object header%s still "
+		"open (file close will complete when %s closed)\n",
+		f->nopen,
+		1 == f->nopen ? " is" : "s are",
+		1 == f->nopen ? "that header is" : "those headers are");
 #endif
-        f->close_pending = TRUE;
-        HRETURN(SUCCEED);
+	f->close_pending = TRUE;
+	HRETURN(SUCCEED);
     } else if (f->close_pending) {
 #ifndef NDEBUG
-        fprintf(stderr, "HDF5-DIAG: H5F_close: operation completed\n");
+	fprintf(stderr, "HDF5-DIAG: H5F_close: operation completed\n");
 #endif
     }
+    
     /* Dump debugging info */
-    if (f->intent & H5F_ACC_DEBUG)
-        H5AC_debug(f);
+    if (f->intent & H5F_ACC_DEBUG) H5AC_debug(f);
 
     /* Close files and release resources */
-    H5F_low_close(f->shared->lf);
+    H5F_low_close(f->shared->lf, &(f->shared->access_parms));
     f = H5F_dest(f);
 
     FUNC_LEAVE(SUCCEED);
@@ -1335,19 +1360,19 @@ H5F_close(H5F_t *f)
 
  USAGE
     herr_t H5Fclose(fid)
-        int32 fid;      IN: File ID of file to close
+	int32 fid;	IN: File ID of file to close
 
  ERRORS
-    ARGS      BADTYPE       Not a file atom. 
-    ATOM      BADATOM       Can't remove atom. 
-    ATOM      BADATOM       Can't unatomize file. 
-    CACHE     CANTFLUSH     Can't flush cache. 
+    ARGS      BADTYPE	    Not a file atom. 
+    ATOM      BADATOM	    Can't remove atom. 
+    ATOM      BADATOM	    Can't unatomize file. 
+    CACHE     CANTFLUSH	    Can't flush cache. 
 
  RETURNS
     SUCCEED/FAIL
 
  DESCRIPTION
-        This function terminates access to an HDF5 file.  If this is the last
+	This function terminates access to an HDF5 file.  If this is the last
     file ID open for a file and if access IDs are still in use, this function
     will fail.
 
@@ -1362,45 +1387,48 @@ H5F_close(H5F_t *f)
 herr_t 
 H5Fclose(hid_t fid)
 {
-    H5F_t                  *file = NULL;        /* file struct for file to close */
-    herr_t                  ret_value = SUCCEED;
+    H5F_t	*file = NULL;	/* file struct for file to close */
+    herr_t	ret_value = SUCCEED;
 
     FUNC_ENTER(H5Fclose, FAIL);
 
     /* Check/fix arguments. */
-    if (H5_FILE != H5A_group(fid))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file atom");
-    if (NULL == (file = H5A_object(fid)))
-        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't unatomize file");
+    if (H5_FILE != H5A_group(fid)) {
+	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file atom");
+    }
+    if (NULL == (file = H5A_object(fid))) {
+	HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't unatomize file");
+    }
 
     /* Close the file */
     ret_value = H5F_close(file);
 
     /* Remove the file atom */
     if (NULL == H5A_remove(fid)) {
-        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't remove atom");
+	HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't remove atom");
     }
-  done:
+
+ done:
     FUNC_LEAVE(ret_value < 0 ? FAIL : SUCCEED);
 }
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_block_read
+ * Function:	H5F_block_read
  *
- * Purpose:     Reads some data from a file/server/etc into a buffer.
- *              The data is contiguous.  The address is relative to the base
- *              address for the file.
+ * Purpose:	Reads some data from a file/server/etc into a buffer.
+ *		The data is contiguous.	 The address is relative to the base
+ *		address for the file.
  *
  * Errors:
- *              IO        READERROR     Low-level read failed. 
+ *		IO	  READERROR	Low-level read failed. 
  *
- * Return:      Success:        SUCCEED
+ * Return:	Success:	SUCCEED
  *
- *              Failure:        FAIL
+ *		Failure:	FAIL
  *
- * Programmer:  Robb Matzke
- *              matzke@llnl.gov
- *              Jul 10 1997
+ * Programmer:	Robb Matzke
+ *		matzke@llnl.gov
+ *		Jul 10 1997
  *
  * Modifications:
  *
@@ -1409,42 +1437,43 @@ H5Fclose(hid_t fid)
 herr_t
 H5F_block_read(H5F_t *f, const haddr_t *addr, size_t size, void *buf)
 {
-    haddr_t                 abs_addr;
+    haddr_t		    abs_addr;
 
     FUNC_ENTER(H5F_block_read, FAIL);
 
     if (0 == size)
-        return 0;
+	return 0;
 
     /* convert the relative address to an absolute address */
     abs_addr = f->shared->base_addr;
     H5F_addr_add(&abs_addr, addr);
 
     /* Read the data */
-    if (H5F_low_read(f->shared->lf, &abs_addr, size, buf) < 0) {
-        HRETURN_ERROR(H5E_IO, H5E_READERROR, FAIL, "low-level read failed");
+    if (H5F_low_read(f->shared->lf, &(f->shared->access_parms),
+		     &abs_addr, size, buf) < 0) {
+	HRETURN_ERROR(H5E_IO, H5E_READERROR, FAIL, "low-level read failed");
     }
     FUNC_LEAVE(SUCCEED);
 }
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_block_write
+ * Function:	H5F_block_write
  *
- * Purpose:     Writes some data from memory to a file/server/etc.  The
- *              data is contiguous.  The address is relative to the base
- *              address.
+ * Purpose:	Writes some data from memory to a file/server/etc.  The
+ *		data is contiguous.  The address is relative to the base
+ *		address.
  *
  * Errors:
- *              IO        WRITEERROR    Low-level write failed. 
- *              IO        WRITEERROR    No write intent. 
+ *		IO	  WRITEERROR	Low-level write failed. 
+ *		IO	  WRITEERROR	No write intent. 
  *
- * Return:      Success:        SUCCEED
+ * Return:	Success:	SUCCEED
  *
- *              Failure:        FAIL
+ *		Failure:	FAIL
  *
- * Programmer:  Robb Matzke
- *              matzke@llnl.gov
- *              Jul 10 1997
+ * Programmer:	Robb Matzke
+ *		matzke@llnl.gov
+ *		Jul 10 1997
  *
  * Modifications:
  *
@@ -1453,43 +1482,46 @@ H5F_block_read(H5F_t *f, const haddr_t *addr, size_t size, void *buf)
 herr_t
 H5F_block_write(H5F_t *f, const haddr_t *addr, size_t size, const void *buf)
 {
-    haddr_t                 abs_addr;
+    haddr_t		    abs_addr;
 
     FUNC_ENTER(H5F_block_write, FAIL);
 
     if (0 == size)
-        return 0;
+	return 0;
 
-    if (0 == (f->intent & H5F_ACC_WRITE)) {
-        HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "no write intent");
+    if (0 == (f->intent & H5F_ACC_RDWR)) {
+	HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "no write intent");
     }
+
     /* Convert the relative address to an absolute address */
     abs_addr = f->shared->base_addr;
     H5F_addr_add(&abs_addr, addr);
 
     /* Write the data */
-    if (H5F_low_write(f->shared->lf, &abs_addr, size, buf)) {
-        HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "low-level write failed");
+    if (H5F_low_write(f->shared->lf, &(f->shared->access_parms),
+		      &abs_addr, size, buf)) {
+	HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "low-level write failed");
     }
+
     FUNC_LEAVE(SUCCEED);
 }
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_debug
+ * Function:	H5F_debug
  *
- * Purpose:     Prints a file header to the specified stream.  Each line
- *              is indented and the field name occupies the specified width
- *              number of characters.
+ * Purpose:	Prints a file header to the specified stream.  Each line
+ *		is indented and the field name occupies the specified width
+ *		number of characters.
  *
  * Errors:
  *
- * Return:      Success:        SUCCEED
+ * Return:	Success:	SUCCEED
  *
- *              Failure:        FAIL
+ *		Failure:	FAIL
  *
- * Programmer:  Robb Matzke
- *              matzke@llnl.gov
- *              Aug  1 1997
+ * Programmer:	Robb Matzke
+ *		matzke@llnl.gov
+ *		Aug  1 1997
  *
  * Modifications:
  *
@@ -1497,7 +1529,7 @@ H5F_block_write(H5F_t *f, const haddr_t *addr, size_t size, const void *buf)
  */
 herr_t
 H5F_debug(H5F_t *f, const haddr_t *addr, FILE * stream, intn indent,
-          intn fwidth)
+	  intn fwidth)
 {
     FUNC_ENTER(H5F_debug, FAIL);
 
@@ -1512,80 +1544,80 @@ H5F_debug(H5F_t *f, const haddr_t *addr, FILE * stream, intn indent,
     fprintf(stream, "%*sFile Boot Block...\n", indent, "");
 
     fprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,
-            "File name:",
-            f->name);
+	    "File name:",
+	    f->name);
     fprintf(stream, "%*s%-*s 0x%08x\n", indent, "", fwidth,
-            "Flags",
-            (unsigned) (f->shared->flags));
+	    "Flags",
+	    (unsigned) (f->shared->flags));
     fprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
-            "Reference count:",
-            (unsigned) (f->shared->nrefs));
+	    "Reference count:",
+	    (unsigned) (f->shared->nrefs));
     fprintf(stream, "%*s%-*s 0x%08lx\n", indent, "", fwidth,
-            "Consistency flags:",
-            (unsigned long) (f->shared->consist_flags));
+	    "Consistency flags:",
+	    (unsigned long) (f->shared->consist_flags));
 
     fprintf(stream, "%*s%-*s ", indent, "", fwidth,
-            "Address of boot block:");
+	    "Address of boot block:");
     H5F_addr_print(stream, &(f->shared->boot_addr));
     fprintf(stream, " (abs)\n");
 
     fprintf(stream, "%*s%-*s ", indent, "", fwidth,
-            "Base address:");
+	    "Base address:");
     H5F_addr_print(stream, &(f->shared->base_addr));
     fprintf(stream, " (abs)\n");
 
     fprintf(stream, "%*s%-*s ", indent, "", fwidth,
-            "Small object heap address:");
+	    "Small object heap address:");
     H5F_addr_print(stream, &(f->shared->smallobj_addr));
     fprintf(stream, " (rel)\n");
 
     fprintf(stream, "%*s%-*s ", indent, "", fwidth,
-            "Free list address:");
+	    "Free list address:");
     H5F_addr_print(stream, &(f->shared->freespace_addr));
     fprintf(stream, " (rel)\n");
 
     fprintf(stream, "%*s%-*s ", indent, "", fwidth,
-            "Total size of hdf5 data:");
+	    "Total size of hdf5 data:");
     H5F_addr_print(stream, &(f->shared->hdf5_eof));
     fprintf(stream, " bytes\n");
 
     fprintf(stream, "%*s%-*s %lu bytes\n", indent, "", fwidth,
-            "Size of user block:",
-            (unsigned long) (f->shared->create_parms.userblock_size));
+	    "Size of user block:",
+	    (unsigned long) (f->shared->create_parms.userblock_size));
     fprintf(stream, "%*s%-*s %u bytes\n", indent, "", fwidth,
-            "Size of file size_t type:",
-            (unsigned) (f->shared->create_parms.sizeof_size));
+	    "Size of file size_t type:",
+	    (unsigned) (f->shared->create_parms.sizeof_size));
     fprintf(stream, "%*s%-*s %u bytes\n", indent, "", fwidth,
-            "Size of file haddr_t type:",
-            (unsigned) (f->shared->create_parms.sizeof_addr));
+	    "Size of file haddr_t type:",
+	    (unsigned) (f->shared->create_parms.sizeof_addr));
     fprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
-            "Symbol table leaf node 1/2 rank:",
-            (unsigned) (f->shared->create_parms.sym_leaf_k));
+	    "Symbol table leaf node 1/2 rank:",
+	    (unsigned) (f->shared->create_parms.sym_leaf_k));
     fprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
-            "Symbol table internal node 1/2 rank:",
-            (unsigned) (f->shared->create_parms.btree_k[H5B_SNODE_ID]));
+	    "Symbol table internal node 1/2 rank:",
+	    (unsigned) (f->shared->create_parms.btree_k[H5B_SNODE_ID]));
     fprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
-            "Boot block version number:",
-            (unsigned) (f->shared->create_parms.bootblock_ver));
+	    "Boot block version number:",
+	    (unsigned) (f->shared->create_parms.bootblock_ver));
     fprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
-            "Small object heap version number:",
-            (unsigned) (f->shared->create_parms.smallobject_ver));
+	    "Small object heap version number:",
+	    (unsigned) (f->shared->create_parms.smallobject_ver));
     fprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
-            "Free list version number:",
-            (unsigned) (f->shared->create_parms.freespace_ver));
+	    "Free list version number:",
+	    (unsigned) (f->shared->create_parms.freespace_ver));
     fprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
-            "Object directory version number:",
-            (unsigned) (f->shared->create_parms.objectdir_ver));
+	    "Object directory version number:",
+	    (unsigned) (f->shared->create_parms.objectdir_ver));
     fprintf(stream, "%*s%-*s %u\n", indent, "", fwidth,
-            "Shared header version number:",
-            (unsigned) (f->shared->create_parms.sharedheader_ver));
+	    "Shared header version number:",
+	    (unsigned) (f->shared->create_parms.sharedheader_ver));
 
     fprintf(stream, "%*s%-*s %s\n", indent, "", fwidth,
-            "Root symbol table entry:",
-            f->shared->root_ent ? "" : "(none)");
+	    "Root symbol table entry:",
+	    f->shared->root_ent ? "" : "(none)");
     if (f->shared->root_ent) {
-        H5G_ent_debug(f, f->shared->root_ent, stream,
-                      indent + 3, MAX(0, fwidth - 3));
+	H5G_ent_debug(f, f->shared->root_ent, stream,
+		      indent + 3, MAX(0, fwidth - 3));
     }
     FUNC_LEAVE(SUCCEED);
 }
diff --git a/src/H5Fcore.c b/src/H5Fcore.c
index 9069df5..d274422 100644
--- a/src/H5Fcore.c
+++ b/src/H5Fcore.c
@@ -19,32 +19,35 @@
 #include <H5Fprivate.h>
 #include <H5MMprivate.h>
 
-#define H5F_CORE_INC    10240   /*amount by which to grow file            */
 #define H5F_CORE_DEV    0xffff  /*pseudo dev for core until we fix things */
 
 #define PABLO_MASK      H5F_core
 static hbool_t          interface_initialize_g = FALSE;
 #define INTERFACE_INIT NULL
 
-static hbool_t          H5F_core_access(const char *name, int mode, H5F_search_t *key);
-static H5F_low_t       *H5F_core_open(const char *name, uintn flags, H5F_search_t *);
-static herr_t           H5F_core_close(H5F_low_t *lf);
-static herr_t           H5F_core_read(H5F_low_t *lf, const haddr_t *addr, size_t size,
-                                      uint8 *buf);
-static herr_t           H5F_core_write(H5F_low_t *lf, const haddr_t *addr, size_t size,
-                                       const uint8 *buf);
+static hbool_t H5F_core_access(const char *name,
+			       const H5F_access_t *access_parms, int mode,
+			       H5F_search_t *key/*out*/);
+static H5F_low_t *H5F_core_open(const char *name,
+				const H5F_access_t *access_parms, uintn flags,
+				H5F_search_t *key/*out*/);
+static herr_t H5F_core_close(H5F_low_t *lf, const H5F_access_t *access_parms);
+static herr_t H5F_core_read(H5F_low_t *lf, const H5F_access_t *access_parms,
+			    const haddr_t *addr, size_t size, uint8 *buf);
+static herr_t H5F_core_write(H5F_low_t *lf, const H5F_access_t *access_parms,
+			     const haddr_t *addr, size_t size,
+			     const uint8 *buf);
+
+const H5F_low_class_t   H5F_LOW_CORE_g[1] = {{
+    H5F_core_access,        /* access method                        */
+    H5F_core_open,          /* open method                          */
+    H5F_core_close,         /* close method                         */
+    H5F_core_read,          /* read method                          */
+    H5F_core_write,         /* write method                         */
+    NULL,                   /* flush method                         */
+    NULL,                   /* extend method                        */
+}};
 
-const H5F_low_class_t   H5F_LOW_CORE[1] =
-{
-    {
-        H5F_core_access,        /* access method                        */
-        H5F_core_open,          /* open method                          */
-        H5F_core_close,         /* close method                         */
-        H5F_core_read,          /* read method                          */
-        H5F_core_write,         /* write method                         */
-        NULL,                   /* flush method                         */
-        NULL,                   /* extend method                        */
-    }};
 
 /*-------------------------------------------------------------------------
  * Function:    H5F_core_access
@@ -66,11 +69,13 @@ const H5F_low_class_t   H5F_LOW_CORE[1] =
  *-------------------------------------------------------------------------
  */
 static hbool_t
-H5F_core_access(const char *name, int mode, H5F_search_t *key /*out */ )
+H5F_core_access(const char *name, const H5F_access_t *access_parms,
+		int mode, H5F_search_t *key/*out*/)
 {
     FUNC_ENTER(H5F_core_access, FAIL);
     FUNC_LEAVE(FALSE);
 }
+
 
 /*-------------------------------------------------------------------------
  * Function:    H5F_core_open
@@ -93,21 +98,23 @@ H5F_core_access(const char *name, int mode, H5F_search_t *key /*out */ )
  *
  *-------------------------------------------------------------------------
  */
-static H5F_low_t       *
-H5F_core_open(const char *name, uintn flags, H5F_search_t *key)
+static H5F_low_t *
+H5F_core_open(const char *name, const H5F_access_t *access_parms,
+	      uintn flags, H5F_search_t *key/*out*/)
 {
     H5F_low_t              *lf = NULL;
     static ino_t            ino = 0;
 
     FUNC_ENTER(H5F_core_open, NULL);
 
-    if (0 == (flags & H5F_ACC_WRITE) || 0 == (flags & H5F_ACC_CREAT)) {
+    if (0 == (flags & H5F_ACC_RDWR) || 0 == (flags & H5F_ACC_CREAT)) {
         HRETURN_ERROR(H5E_IO, H5E_CANTOPENFILE, NULL,
                       "must creat file with write access");
     }
+    
     lf = H5MM_xcalloc(1, sizeof(H5F_low_t));
-    lf->u.core.mem = H5MM_xmalloc(H5F_CORE_INC);
-    lf->u.core.alloc = H5F_CORE_INC;
+    lf->u.core.mem = NULL;
+    lf->u.core.alloc = 0;
     lf->u.core.size = 0;
     H5F_addr_reset(&(lf->eof));
 
@@ -115,8 +122,10 @@ H5F_core_open(const char *name, uintn flags, H5F_search_t *key)
         key->dev = H5F_CORE_DEV;
         key->ino = ino++;
     }
+    
     FUNC_LEAVE(lf);
 }
+
 
 /*-------------------------------------------------------------------------
  * Function:    H5F_core_close
@@ -137,7 +146,7 @@ H5F_core_open(const char *name, uintn flags, H5F_search_t *key)
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F_core_close(H5F_low_t *lf)
+H5F_core_close(H5F_low_t *lf, const H5F_access_t *access_parms)
 {
     FUNC_ENTER(H5F_core_close, FAIL);
 
@@ -147,6 +156,7 @@ H5F_core_close(H5F_low_t *lf)
 
     FUNC_LEAVE(SUCCEED);
 }
+
 
 /*-------------------------------------------------------------------------
  * Function:    H5F_core_read
@@ -169,7 +179,8 @@ H5F_core_close(H5F_low_t *lf)
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F_core_read(H5F_low_t *lf, const haddr_t *addr, size_t size, uint8 *buf)
+H5F_core_read(H5F_low_t *lf, const H5F_access_t *access_parms,
+	      const haddr_t *addr, size_t size, uint8 *buf)
 {
     size_t                  n;
     size_t                  eof;
@@ -192,6 +203,7 @@ H5F_core_read(H5F_low_t *lf, const haddr_t *addr, size_t size, uint8 *buf)
 
     FUNC_LEAVE(SUCCEED);
 }
+
 
 /*-------------------------------------------------------------------------
  * Function:    H5F_core_write
@@ -214,27 +226,39 @@ H5F_core_read(H5F_low_t *lf, const haddr_t *addr, size_t size, uint8 *buf)
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F_core_write(H5F_low_t *lf, const haddr_t *addr, size_t size,
-               const uint8 *buf)
+H5F_core_write(H5F_low_t *lf, const H5F_access_t *access_parms,
+	       const haddr_t *addr, size_t size, const uint8 *buf)
 {
-    size_t                  inc_amount;
+    size_t		need_more;
+    size_t		increment = 1;
+    
 
     FUNC_ENTER(H5F_core_write, FAIL);
 
     assert(lf);
     assert(addr && H5F_addr_defined(addr));
     assert(buf);
+    assert (!access_parms || H5F_LOW_CORE==access_parms->driver);
 
-    /* Allocate more space */
+    /*
+     * Allocate more space.  We always allocate a multiple of the increment
+     * size, which is either defined in the file access property list or
+     * which defaults to one.
+     */
     if (addr->offset + size > lf->u.core.alloc) {
-        inc_amount = MAX(addr->offset + size - lf->u.core.alloc, H5F_CORE_INC);
-        lf->u.core.alloc = lf->u.core.alloc + inc_amount;
+	if (access_parms) increment = access_parms->u.core.increment;
+	need_more = addr->offset+size - lf->u.core.alloc;
+	need_more = increment*((need_more+increment-1)/increment);
+
+        lf->u.core.alloc = lf->u.core.alloc + need_more;
         lf->u.core.mem = H5MM_xrealloc(lf->u.core.mem, lf->u.core.alloc);
     }
+    
     /* Move the physical EOF marker */
     if (addr->offset + size > lf->u.core.size) {
         lf->u.core.size = addr->offset + size;
     }
+    
     /* Copy data */
     HDmemcpy(lf->u.core.mem + addr->offset, buf, size);
 
diff --git a/src/H5Ffamily.c b/src/H5Ffamily.c
index 025039c..dba22f1 100644
--- a/src/H5Ffamily.c
+++ b/src/H5Ffamily.c
@@ -1,25 +1,25 @@
 /*
  * Copyright (C) 1997 Spizella Software
- *                    All rights reserved.
+ *		      All rights reserved.
  *
  * Programmer: Robb Matzke <matzke@llnl.gov>
- *             Monday, November 10, 1997
- *
- * Purpose:     Implements a family of files that acts as a single hdf5
- *              file.  The purpose is to be able to split a huge file on a
- *              64-bit platform, transfer all the <2GB members to a 32-bit
- *              platform, and then access the entire huge file on the 32-bit
- *              platform.
- *
- *              All family members are logically the same size although their
- *              physical sizes may vary.  The logical member size is
- *              determined by looking at the physical size of the first
- *              member and rounding that up to the next power of two.  When
- *              creating a file family, the first member is created with a
- *              predefined physical size (actually, this happens when the
- *              file family is flushed, and can be quite time consuming on
- *              file systems that don't implement holes, like nfs).
- *              
+ *	       Monday, November 10, 1997
+ *
+ * Purpose:	Implements a family of files that acts as a single hdf5
+ *		file.  The purpose is to be able to split a huge file on a
+ *		64-bit platform, transfer all the <2GB members to a 32-bit
+ *		platform, and then access the entire huge file on the 32-bit
+ *		platform.
+ *
+ *		All family members are logically the same size although their
+ *		physical sizes may vary.  The logical member size is
+ *		determined by looking at the physical size of the first
+ *		member and rounding that up to the next power of two.  When
+ *		creating a file family, the first member is created with a
+ *		predefined physical size (actually, this happens when the
+ *		file family is flushed, and can be quite time consuming on
+ *		file systems that don't implement holes, like nfs).
+ *		
  */
 #include <H5private.h>
 #include <H5Eprivate.h>
@@ -27,7 +27,7 @@
 #include <H5MMprivate.h>
 
 #define PABLO_MASK H5F_family
-static hbool_t          interface_initialize_g = FALSE;
+static hbool_t		interface_initialize_g = FALSE;
 #define INTERFACE_INIT NULL
 
 /*
@@ -38,81 +38,104 @@ static hbool_t          interface_initialize_g = FALSE;
  * Smaller values result in files of a more manageable size (from a human
  * perspective) but also limit the total logical size of the hdf5 file.
  */
-#define H5F_FAM_DFLT_NBITS      26u     /*64MB */
-
-#define H5F_FAM_MASK(N)         (((uint64)1<<(N))-1)
-#define H5F_FAM_OFFSET(ADDR,N)  ((off_t)((ADDR)->offset & H5F_FAM_MASK(N)))
-#define H5F_FAM_MEMBNO(ADDR,N)  ((intn)((ADDR)->offset >> N))
-
-static hbool_t H5F_fam_access(const char *name, int mode, H5F_search_t *key);
-static H5F_low_t *H5F_fam_open(const char *name, uintn flags, H5F_search_t *);
-static herr_t H5F_fam_close(H5F_low_t *lf);
-static herr_t H5F_fam_read(H5F_low_t *lf, const haddr_t *addr, size_t size,
-			   uint8 *buf);
-static herr_t H5F_fam_write(H5F_low_t *lf, const haddr_t *addr, size_t size,
+#define H5F_FAM_DFLT_NBITS	26u	/*64MB */
+
+#define H5F_FAM_MASK(N)		(((uint64)1<<(N))-1)
+#define H5F_FAM_OFFSET(ADDR,N)	((off_t)((ADDR)->offset & H5F_FAM_MASK(N)))
+#define H5F_FAM_MEMBNO(ADDR,N)	((intn)((ADDR)->offset >> N))
+
+static hbool_t H5F_fam_access(const char *name,
+			      const H5F_access_t *access_parms, int mode,
+			      H5F_search_t *key/*out*/);
+static H5F_low_t *H5F_fam_open(const char *name,
+			       const H5F_access_t *access_parms, uintn flags,
+			       H5F_search_t *key/*out*/);
+static herr_t H5F_fam_close(H5F_low_t *lf, const H5F_access_t *access_parms);
+static herr_t H5F_fam_read(H5F_low_t *lf, const H5F_access_t *access_parms,
+			   const haddr_t *addr, size_t size, uint8 *buf);
+static herr_t H5F_fam_write(H5F_low_t *lf, const H5F_access_t *access_parms,
+			    const haddr_t *addr, size_t size,
 			    const uint8 *buf);
-static herr_t H5F_fam_flush(H5F_low_t *lf);
-
-const H5F_low_class_t H5F_LOW_FAM[1] = {{
-    H5F_fam_access,         /* access method                        */
-    H5F_fam_open,           /* open method                          */
-    H5F_fam_close,          /* close method                         */
-    H5F_fam_read,           /* read method                          */
-    H5F_fam_write,          /* write method                         */
-    H5F_fam_flush,          /* flush method                         */
-    NULL,                   /* extend method                        */
+static herr_t H5F_fam_flush(H5F_low_t *lf, const H5F_access_t *access_parms);
+
+const H5F_low_class_t H5F_LOW_FAMILY_g[1] = {{
+    H5F_fam_access,	    /* access method			    */
+    H5F_fam_open,	    /* open method			    */
+    H5F_fam_close,	    /* close method			    */
+    H5F_fam_read,	    /* read method			    */
+    H5F_fam_write,	    /* write method			    */
+    H5F_fam_flush,	    /* flush method			    */
+    NULL,		    /* extend method			    */
 }};
 
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_fam_open
+ * Function:	H5F_fam_open
  *
- * Purpose:     Opens a file family with the specified base name.  The name
- *              should contain a printf-style "%d" field which will be
- *              expanded with a zero-origin family member number.
+ * Purpose:	Opens a file family with the specified base name.  The name
+ *		should contain a printf-style "%d" field which will be
+ *		expanded with a zero-origin family member number.
  *
- * Bugs:        We don't check for overflow on the name, so keep it under
- *              4kb, please.  Also, we don't actually check for the `%d'
- *              field because we assume that the caller already did.  Who
- *              knows what happens when all the family member names are the
- *              same!
+ * Bugs:	We don't check for overflow on the name, so keep it under
+ *		4kb, please.  Also, we don't actually check for the `%d'
+ *		field because we assume that the caller already did.  Who
+ *		knows what happens when all the family member names are the
+ *		same!
  *
- * Return:      Success:        Low-level file pointer
+ * Return:	Success:	Low-level file pointer
  *
- *              Failure:        NULL
+ *		Failure:	NULL
  *
- * Programmer:  Robb Matzke
- *              Monday, November 10, 1997
+ * Programmer:	Robb Matzke
+ *		Monday, November 10, 1997
  *
  * Modifications:
  *
  *-------------------------------------------------------------------------
  */
-static H5F_low_t       *
-H5F_fam_open(const char *name, uintn flags, H5F_search_t *key /*out */ )
+static H5F_low_t *
+H5F_fam_open(const char *name, const H5F_access_t *access_parms,
+	     uintn flags, H5F_search_t *key/*out*/)
 {
-    H5F_low_t              *ret_value = NULL, *lf = NULL;
-    H5F_low_t              *member = NULL;      /*a family member               */
-    char                    member_name[4096];  /*name of family member         */
-    intn                    membno;     /*member number (zero-origin)   */
-    size_t                  nbits = H5F_FAM_DFLT_NBITS;         /*num bits in an offset        */
-    haddr_t                 tmp_addr;   /*temporary address             */
+    H5F_low_t	*ret_value = NULL;
+    H5F_low_t	*lf = NULL;
+    H5F_low_t	*member = NULL;		/*a family member		*/
+    char	member_name[4096];	/*name of family member		*/
+    intn	membno;			/*member number (zero-origin)	*/
+    size_t	nbits = H5F_FAM_DFLT_NBITS; /*num bits in an offset     */
+    haddr_t	tmp_addr;		/*temporary address		*/
+    const H5F_low_class_t *memb_type;	/*type of family member		*/
 
     FUNC_ENTER(H5F_fam_open, NULL);
 
+    assert (access_parms);
+    assert (H5F_LOW_FAMILY==access_parms->driver);
+
+    /*
+     * Use the default file driver or the specified driver for each of the
+     * family members.
+     */
+    if (access_parms->u.fam.memb_access) {
+	memb_type = H5F_low_class (access_parms->u.fam.memb_access->driver);
+    } else {
+	memb_type = H5F_low_class (H5F_LOW_DFLT);
+    }
+
     /*
      * If we're truncating the file then delete all but the first family
-     * member.  Use the default number of bits for the offset.
+     * member.	Use the default number of bits for the offset.
      */
-    if ((flags & H5F_ACC_WRITE) && (flags & H5F_ACC_TRUNC)) {
-        for (membno = 1; /*void */ ; membno++) {
-            sprintf(member_name, name, membno);
-            if (!H5F_low_access(H5F_LOW_DFLT, member_name, F_OK, NULL)) {
-                break;
-            } else if (unlink(member_name) < 0) {
-                HGOTO_ERROR(H5E_IO, H5E_CANTINIT, NULL, "can't delete member");
-            }
-        }
+    if ((flags & H5F_ACC_RDWR) && (flags & H5F_ACC_TRUNC)) {
+	for (membno = 1; /*void*/; membno++) {
+	    sprintf(member_name, name, membno);
+	    if (!H5F_low_access(memb_type, member_name,
+				access_parms->u.fam.memb_access,
+				F_OK, NULL)) {
+		break;
+	    } else if (unlink(member_name) < 0) {
+		HGOTO_ERROR(H5E_IO, H5E_CANTINIT, NULL, "can't delete member");
+	    }
+	}
     }
     /* Create the file descriptor */
     lf = H5MM_xcalloc(1, sizeof(H5F_low_t));
@@ -120,33 +143,34 @@ H5F_fam_open(const char *name, uintn flags, H5F_search_t *key /*out */ )
     lf->u.fam.flags = (flags & ~H5F_ACC_CREAT);
 
     /* Open all existing members */
-    for (membno = 0; /*void */ ; membno++) {
-        sprintf(member_name, name, membno);
-
-        /*
-         * Open the family member.  After the first member is opened or created,
-         * turn off the creation flag so we don't create a zillion family
-         * members.
-         */
-        member = H5F_low_open(H5F_LOW_DFLT, member_name, flags,
-                              0 == membno ? key : NULL);
-        if (!member) {
-            if (0 == membno) {
-                HGOTO_ERROR(H5E_IO, H5E_CANTOPENFILE, NULL,
-                            "can't open first family member");
-            }
-            break;
-        }
-        flags &= ~H5F_ACC_CREAT;
-
-        /* Add the member to the family */
-        if (lf->u.fam.nmemb >= lf->u.fam.nalloc) {
-            lf->u.fam.nalloc = MAX(100, 2 * lf->u.fam.nalloc);
-            lf->u.fam.memb = H5MM_xrealloc(lf->u.fam.memb,
-                                    lf->u.fam.nalloc * sizeof(H5F_low_t *));
-        }
-        lf->u.fam.memb[lf->u.fam.nmemb++] = member;
-        member = NULL;
+    for (membno = 0; /*void*/; membno++) {
+	sprintf(member_name, name, membno);
+
+	/*
+	 * Open the family member.  After the first member is opened or
+	 * created, turn off the creation flag so we don't create a zillion
+	 * family members.
+	 */
+	member = H5F_low_open(memb_type, member_name,
+			      access_parms->u.fam.memb_access, flags,
+			      0 == membno ? key : NULL);
+	if (!member) {
+	    if (0 == membno) {
+		HGOTO_ERROR(H5E_IO, H5E_CANTOPENFILE, NULL,
+			    "can't open first family member");
+	    }
+	    break;
+	}
+	flags &= ~H5F_ACC_CREAT;
+
+	/* Add the member to the family */
+	if (lf->u.fam.nmemb >= lf->u.fam.nalloc) {
+	    lf->u.fam.nalloc = MAX(100, 2 * lf->u.fam.nalloc);
+	    lf->u.fam.memb = H5MM_xrealloc(lf->u.fam.memb,
+				       lf->u.fam.nalloc * sizeof(H5F_low_t *));
+	}
+	lf->u.fam.memb[lf->u.fam.nmemb++] = member;
+	member = NULL;
     }
 
     /*
@@ -155,32 +179,36 @@ H5F_fam_open(const char *name, uintn flags, H5F_search_t *key /*out */ )
      * member.
      */
     if (lf->u.fam.nmemb >= 2) {
-        size_t                  size = H5F_low_size(lf->u.fam.memb[0], &tmp_addr);
-        for (nbits = 8 * sizeof(size_t) - 1; nbits > 0; --nbits) {
-            size_t                  mask = (size_t) 1 << nbits;
-            if (size & mask) {
-                if (size != mask) {
-                    size++;
+	size_t size = H5F_low_size(lf->u.fam.memb[0], &tmp_addr);
+	for (nbits=8*sizeof(size_t)-1; nbits>0; --nbits) {
+	    size_t mask = (size_t)1 << nbits;
+	    if (size & mask) {
+		if (size != mask) {
+		    size++;
 #ifdef H5F_DEBUG
-                    fprintf(stderr, "HDF5-DIAG: family member size was rounded up "
-                            "to a power of 2");
+		    fprintf(stderr, "HDF5-DIAG: family member size was rounded up "
+			    "to a power of 2");
 #endif
-                }
-                break;
-            }
-        }
+		}
+		break;
+	    }
+	}
     }
     lf->u.fam.offset_bits = nbits;
 
 #ifdef H5F_DEBUG
     if (nbits >= 30) {
-        fprintf(stderr, "HDF5-DIAG: family members are %dGB\n", 1 << (nbits - 30));
+	fprintf(stderr, "HDF5-DIAG: family members are %dGB\n",
+		1 << (nbits-30));
     } else if (nbits >= 20) {
-        fprintf(stderr, "HDF5-DIAG: family members are %dMB\n", 1 << (nbits - 20));
+	fprintf(stderr, "HDF5-DIAG: family members are %dMB\n",
+		1 << (nbits-20));
     } else if (nbits >= 10) {
-        fprintf(stderr, "HDF5-DIAG: family members are %dkB\n", 1 << (nbits - 10));
+	fprintf(stderr, "HDF5-DIAG: family members are %dkB\n",
+		1 << (nbits-10));
     } else {
-        fprintf(stderr, "HDF5-DIAG: family members are %d bytes\n", 1 << nbits);
+	fprintf(stderr, "HDF5-DIAG: family members are %d bytes\n",
+		1 << nbits);
     }
 #endif
 
@@ -188,50 +216,51 @@ H5F_fam_open(const char *name, uintn flags, H5F_search_t *key /*out */ )
      * Get the total family size and store it in the max_addr field.
      */
     assert(lf->u.fam.nmemb >= 1);
-    lf->eof.offset = (size_t) 1 << lf->u.fam.offset_bits;
-    lf->eof.offset *= (lf->u.fam.nmemb - 1);
-    lf->eof.offset += lf->u.fam.memb[lf->u.fam.nmemb - 1]->eof.offset;
+    lf->eof.offset = (size_t)1 << lf->u.fam.offset_bits;
+    lf->eof.offset *= (lf->u.fam.nmemb-1);
+    lf->eof.offset += lf->u.fam.memb[lf->u.fam.nmemb-1]->eof.offset;
 
     HRETURN(lf);
 
   done:
     if (!ret_value) {
-        if (lf) {
-            H5F_fam_close(lf);
-            H5MM_xfree(lf);
-        }
+	if (lf) {
+	    H5F_fam_close(lf, access_parms);
+	    H5MM_xfree(lf);
+	}
     }
     FUNC_LEAVE(ret_value);
 }
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_fam_close
+ * Function:	H5F_fam_close
  *
- * Purpose:     Closes all members of a file family and releases resources
- *              used by the file descriptor.
+ * Purpose:	Closes all members of a file family and releases resources
+ *		used by the file descriptor.
  *
- * Return:      Success:        SUCCEED
+ * Return:	Success:	SUCCEED
  *
- *              Failure:        FAIL
+ *		Failure:	FAIL
  *
- * Programmer:  Robb Matzke
- *              Monday, November 10, 1997
+ * Programmer:	Robb Matzke
+ *		Monday, November 10, 1997
  *
  * Modifications:
  *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F_fam_close(H5F_low_t *lf)
+H5F_fam_close(H5F_low_t *lf, const H5F_access_t *access_parms)
 {
-    intn                    membno;
+    intn		    membno;
 
     FUNC_ENTER(H5F_fam_close, FAIL);
 
     assert(lf);
 
     for (membno = 0; membno < lf->u.fam.nmemb; membno++) {
-        lf->u.fam.memb[membno] = H5F_low_close(lf->u.fam.memb[membno]);
+	lf->u.fam.memb[membno] = H5F_low_close(lf->u.fam.memb[membno],
+					      access_parms->u.fam.memb_access);
     }
     H5MM_xfree(lf->u.fam.memb);
     H5MM_xfree(lf->u.fam.name);
@@ -240,36 +269,37 @@ H5F_fam_close(H5F_low_t *lf)
 }
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_fam_read
+ * Function:	H5F_fam_read
  *
- * Purpose:     Reads a chunk of contiguous data from the file family.
- *              Reading past the physical end of a file returns zeros instead
- *              of failing. We must insure that if the logical end of file is
- *              before the physical end of file that we will read zeros there
- *              also (the only time this can happen is if we create a family
- *              and then close it before the first member is filled, since
- *              flushing the file causes the first member to be physically
- *              extended to it's maximum size).
+ * Purpose:	Reads a chunk of contiguous data from the file family.
+ *		Reading past the physical end of a file returns zeros instead
+ *		of failing. We must insure that if the logical end of file is
+ *		before the physical end of file that we will read zeros there
+ *		also (the only time this can happen is if we create a family
+ *		and then close it before the first member is filled, since
+ *		flushing the file causes the first member to be physically
+ *		extended to it's maximum size).
  *
- * Return:      Success:        SUCCEED
+ * Return:	Success:	SUCCEED
  *
- *              Failure:        FAIL
+ *		Failure:	FAIL
  *
- * Programmer:  Robb Matzke
- *              Monday, November 10, 1997
+ * Programmer:	Robb Matzke
+ *		Monday, November 10, 1997
  *
  * Modifications:
  *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F_fam_read(H5F_low_t *lf, const haddr_t *addr, size_t size, uint8 *buf)
+H5F_fam_read(H5F_low_t *lf, const H5F_access_t *access_parms,
+	     const haddr_t *addr, size_t size, uint8 *buf)
 {
-    size_t                  nbytes;
-    haddr_t                 cur_addr;
-    uintn                   membno;
-    off_t                   offset;
-    size_t                  member_size;
+    size_t		    nbytes;
+    haddr_t		    cur_addr;
+    uintn		    membno;
+    off_t		    offset;
+    size_t		    member_size;
 
     FUNC_ENTER(H5F_fam_read, FAIL);
 
@@ -283,154 +313,168 @@ H5F_fam_read(H5F_low_t *lf, const haddr_t *addr, size_t size, uint8 *buf)
     cur_addr = *addr;
 
     while (size > 0) {
-        if (membno >= lf->u.fam.nmemb) {
-            HDmemset(buf, 0, size);
-            break;
-        } else {
-            nbytes = MIN(size, member_size - offset);
-            cur_addr.offset = offset;
-            if (H5F_low_read(lf->u.fam.memb[membno], &cur_addr,
-                             nbytes, buf) < 0) {
-                HRETURN_ERROR(H5E_IO, H5E_READERROR, FAIL,
-                              "can't read from family member");
-            }
-            buf += nbytes;
-            size -= nbytes;
-            membno++;
-            offset = 0;
-        }
+	if (membno >= lf->u.fam.nmemb) {
+	    HDmemset(buf, 0, size);
+	    break;
+	} else {
+	    nbytes = MIN(size, member_size - offset);
+	    cur_addr.offset = offset;
+	    if (H5F_low_read(lf->u.fam.memb[membno],
+			     access_parms->u.fam.memb_access,
+			     &cur_addr, nbytes, buf) < 0) {
+		HRETURN_ERROR(H5E_IO, H5E_READERROR, FAIL,
+			      "can't read from family member");
+	    }
+	    buf += nbytes;
+	    size -= nbytes;
+	    membno++;
+	    offset = 0;
+	}
     }
 
     FUNC_LEAVE(SUCCEED);
 }
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_fam_write
+ * Function:	H5F_fam_write
  *
- * Purpose:     Writes BUF to the family of files.  The superclass has
- *              already insured that we aren't writing past the logical end
- *              of file, so this function will extend the physical file to
- *              accommodate the new data if necessary.
+ * Purpose:	Writes BUF to the family of files.  The superclass has
+ *		already insured that we aren't writing past the logical end
+ *		of file, so this function will extend the physical file to
+ *		accommodate the new data if necessary.
  *
- * Return:      Success:        SUCCEED
+ * Return:	Success:	SUCCEED
  *
- *              Failure:        FAIL
+ *		Failure:	FAIL
  *
- * Programmer:  Robb Matzke
- *              Monday, November 10, 1997
+ * Programmer:	Robb Matzke
+ *		Monday, November 10, 1997
  *
  * Modifications:
  *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F_fam_write(H5F_low_t *lf, const haddr_t *addr, size_t size,
-              const uint8 *buf)
+H5F_fam_write(H5F_low_t *lf, const H5F_access_t *access_parms,
+	      const haddr_t *addr, size_t size, const uint8 *buf)
 {
-    size_t                  nbytes;
-    haddr_t                 cur_addr, max_addr;
-    uintn                   membno;
-    off_t                   offset;
-    H5F_low_t              *member = NULL;
-    char                    member_name[4096];
-    intn                    i;
-    size_t                  member_size;
-
+    size_t		   	nbytes;
+    haddr_t		    	cur_addr, max_addr;
+    uintn		    	membno;
+    off_t		    	offset;
+    H5F_low_t		   	*member = NULL;
+    char		    	member_name[4096];
+    intn		    	i;
+    size_t		    	member_size;
+    const H5F_low_class_t	*memb_type = NULL;
+    
     FUNC_ENTER(H5F_fam_write, FAIL);
 
+    /* Check args */
     assert(lf);
     assert(addr && H5F_addr_defined(addr));
     assert(buf);
+    assert (access_parms);
+    assert (H5F_LOW_FAMILY==access_parms->driver);
 
+    /* Get the member driver */
+    if (access_parms->u.fam.memb_access) {
+	memb_type = H5F_low_class (access_parms->u.fam.memb_access->driver);
+    } else {
+	memb_type = H5F_low_class (H5F_LOW_DFLT);
+    }
+    
     member_size = (size_t) 1 << lf->u.fam.offset_bits;
     membno = H5F_FAM_MEMBNO(addr, lf->u.fam.offset_bits);
     offset = H5F_FAM_OFFSET(addr, lf->u.fam.offset_bits);
     cur_addr = *addr;
 
     while (size > 0) {
-        nbytes = MIN(size, member_size - offset);
-        cur_addr.offset = offset;
-
-        if (membno >= lf->u.fam.nmemb) {
-            /*
-             * We're writing past the end of the last family member--create the
-             * new family member(s)
-             */
-            for (i = lf->u.fam.nmemb; i <= membno; i++) {
-                sprintf(member_name, lf->u.fam.name, i);
-                member = H5F_low_open(H5F_LOW_DFLT, member_name,
-                                      lf->u.fam.flags | H5F_ACC_CREAT,
-                                      NULL);
-                if (!member) {
-                    HRETURN_ERROR(H5E_IO, H5E_CANTOPENFILE, FAIL,
-                                  "can't create a new member");
-                }
-                /*
-                 * For members in the middle, set their logical eof to the
-                 * maximum possible value.
-                 */
-                if (i < membno) {
-                    H5F_addr_reset(&max_addr);
-                    H5F_addr_inc(&max_addr, member_size);
-                    H5F_low_seteof(member, &max_addr);
-                }
-                if (lf->u.fam.nmemb >= lf->u.fam.nalloc) {
-                    lf->u.fam.nalloc *= 2;
-                    lf->u.fam.memb = H5MM_xrealloc(lf->u.fam.memb,
-                                                   (lf->u.fam.nalloc *
-                                                    sizeof(H5F_low_t *)));
-                }
-                lf->u.fam.memb[lf->u.fam.nmemb++] = member;
-            }
-        }
-        /*
-         * Make sure the logical eof is large enough to handle the request.
-         */
-        max_addr = cur_addr;
-        H5F_addr_inc(&max_addr, nbytes);
-        H5F_low_seteof(lf->u.fam.memb[membno], &max_addr);
-
-        /* Write the data to the member */
-        if (H5F_low_write(lf->u.fam.memb[membno], &cur_addr,
-                          nbytes, buf) < 0) {
-            HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, FAIL,
-                          "can't write to family member");
-        }
-        buf += nbytes;
-        size -= nbytes;
-        membno++;
-        offset = 0;
+	nbytes = MIN(size, member_size - offset);
+	cur_addr.offset = offset;
+
+	if (membno >= lf->u.fam.nmemb) {
+	    /*
+	     * We're writing past the end of the last family member--create the
+	     * new family member(s)
+	     */
+	    for (i = lf->u.fam.nmemb; i <= membno; i++) {
+		sprintf(member_name, lf->u.fam.name, i);
+		member = H5F_low_open(memb_type, member_name,
+				      access_parms->u.fam.memb_access, 
+				      lf->u.fam.flags | H5F_ACC_CREAT,
+				      NULL);
+		if (!member) {
+		    HRETURN_ERROR(H5E_IO, H5E_CANTOPENFILE, FAIL,
+				  "can't create a new member");
+		}
+		/*
+		 * For members in the middle, set their logical eof to the
+		 * maximum possible value.
+		 */
+		if (i < membno) {
+		    H5F_addr_reset(&max_addr);
+		    H5F_addr_inc(&max_addr, member_size);
+		    H5F_low_seteof(member, &max_addr);
+		}
+		if (lf->u.fam.nmemb >= lf->u.fam.nalloc) {
+		    lf->u.fam.nalloc *= 2;
+		    lf->u.fam.memb = H5MM_xrealloc(lf->u.fam.memb,
+						   (lf->u.fam.nalloc *
+						    sizeof(H5F_low_t *)));
+		}
+		lf->u.fam.memb[lf->u.fam.nmemb++] = member;
+	    }
+	}
+	/*
+	 * Make sure the logical eof is large enough to handle the request.
+	 */
+	max_addr = cur_addr;
+	H5F_addr_inc(&max_addr, nbytes);
+	H5F_low_seteof(lf->u.fam.memb[membno], &max_addr);
+
+	/* Write the data to the member */
+	if (H5F_low_write(lf->u.fam.memb[membno],
+			  access_parms->u.fam.memb_access,
+			  &cur_addr, nbytes, buf) < 0) {
+	    HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, FAIL,
+			  "can't write to family member");
+	}
+	buf += nbytes;
+	size -= nbytes;
+	membno++;
+	offset = 0;
     }
 
     FUNC_LEAVE(SUCCEED);
 }
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_fam_flush
+ * Function:	H5F_fam_flush
  *
- * Purpose:     Flushes all data to disk and makes sure that the first member
- *              is as large as a member can be so we can accurately detect
- *              the member size if we open this file for read access at a
- *              later date.
+ * Purpose:	Flushes all data to disk and makes sure that the first member
+ *		is as large as a member can be so we can accurately detect
+ *		the member size if we open this file for read access at a
+ *		later date.
  *
- * Return:      Success:        SUCCEED
+ * Return:	Success:	SUCCEED
  *
- *              Failure:        FAIL
+ *		Failure:	FAIL
  *
- * Programmer:  Robb Matzke
- *              Monday, November 10, 1997
+ * Programmer:	Robb Matzke
+ *		Monday, November 10, 1997
  *
  * Modifications:
  *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F_fam_flush(H5F_low_t *lf)
+H5F_fam_flush(H5F_low_t *lf, const H5F_access_t *access_parms)
 {
-    int                     membno, nerrors = 0;
-    uint8                   buf[1];
-    haddr_t                 addr1, addr2, addr3;
-    size_t                  max_offset;
+    int			    membno, nerrors = 0;
+    uint8		    buf[1];
+    haddr_t		    addr1, addr2, addr3;
+    size_t		    max_offset;
 
     FUNC_ENTER(H5F_fam_flush, FAIL);
 
@@ -444,98 +488,118 @@ H5F_fam_flush(H5F_low_t *lf)
     max_offset = H5F_FAM_MASK(lf->u.fam.offset_bits);
     H5F_addr_reset(&addr1);
     H5F_addr_inc(&addr1, max_offset);
-    H5F_low_size(lf->u.fam.memb[0], &addr2);    /*remember logical eof */
+    H5F_low_size(lf->u.fam.memb[0], &addr2);	/*remember logical eof */
     addr3 = addr1;
     H5F_addr_inc(&addr3, (size_t) 1);
-    H5F_low_seteof(lf->u.fam.memb[0], &addr3);  /*prevent a warning */
-    if (H5F_low_read(lf->u.fam.memb[0], &addr1, 1, buf) < 0) {
-        HRETURN_ERROR(H5E_IO, H5E_READERROR, FAIL,
-                      "can't read from first family member");
+    H5F_low_seteof(lf->u.fam.memb[0], &addr3);	/*prevent a warning */
+    if (H5F_low_read(lf->u.fam.memb[0], access_parms->u.fam.memb_access,
+		     &addr1, 1, buf) < 0) {
+	HRETURN_ERROR(H5E_IO, H5E_READERROR, FAIL,
+		      "can't read from first family member");
     }
-    if (H5F_low_write(lf->u.fam.memb[0], &addr1, 1, buf) < 0) {
-        HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, FAIL,
-                      "can't write to first family member");
+    if (H5F_low_write(lf->u.fam.memb[0], access_parms->u.fam.memb_access,
+		      &addr1, 1, buf) < 0) {
+	HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, FAIL,
+		      "can't write to first family member");
     }
-    H5F_low_seteof(lf->u.fam.memb[0], &addr2);  /*reset old eof */
+    H5F_low_seteof(lf->u.fam.memb[0], &addr2);	/*reset old eof */
 
     /*
-     * Flush each member file.  Don't return an error status until we've
+     * Flush each member file.	Don't return an error status until we've
      * flushed as much as possible.
      */
     for (membno = 0; membno < lf->u.fam.nmemb; membno++) {
-        if (H5F_low_flush(lf->u.fam.memb[membno]) < 0) {
-            nerrors++;
-        }
+	if (H5F_low_flush(lf->u.fam.memb[membno],
+			  access_parms->u.fam.memb_access) < 0) {
+	    nerrors++;
+	}
     }
     if (nerrors) {
-        HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, FAIL,
-                      "can't flush family member");
+	HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, FAIL,
+		      "can't flush family member");
     }
     FUNC_LEAVE(SUCCEED);
 }
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_fam_access
+ * Function:	H5F_fam_access
  *
- * Purpose:     Determines if all members of the file family can be accessed
- *              and returns the key for the first member of the family.
+ * Purpose:	Determines if all members of the file family can be accessed
+ *		and returns the key for the first member of the family.
  *
- * Return:      Success:        TRUE or FALSE
+ * Return:	Success:	TRUE or FALSE
  *
- *              Failure:        FAIL
+ *		Failure:	FAIL
  *
- * Programmer:  Robb Matzke
- *              Monday, November 10, 1997
+ * Programmer:	Robb Matzke
+ *		Monday, November 10, 1997
  *
  * Modifications:
  *
  *-------------------------------------------------------------------------
  */
 static hbool_t
-H5F_fam_access(const char *name, int mode, H5F_search_t *key /*out */ )
+H5F_fam_access(const char *name, const H5F_access_t *access_parms,
+	       int mode, H5F_search_t *key/*out*/)
 {
-    intn        membno;
-    char        member_name[4096];
-    hbool_t     status;
-    hbool_t	ret_value = FALSE;
+    intn			membno;
+    char			member_name[4096];
+    hbool_t			status;
+    hbool_t			ret_value = FALSE;
+    const H5F_low_class_t	*memb_type = NULL;
 
     FUNC_ENTER(H5F_fam_access, FAIL);
 
+    /* Check args */
+    assert (name && *name);
+    assert (access_parms);
+    assert (H5F_LOW_FAMILY==access_parms->driver);
+
+    /* Get the driver for the family members */
+    if (access_parms->u.fam.memb_access) {
+	memb_type = H5F_low_class (access_parms->u.fam.memb_access->driver);
+    } else {
+	memb_type = H5F_low_class (H5F_LOW_DFLT);
+    }
+
+    /* Access the members */
     for (membno=0; /*void*/; membno++) {
-        sprintf(member_name, name, membno);
-        status = H5F_low_access(H5F_LOW_DFLT, member_name, mode,
-                                0 == membno ? key : NULL);
-
-        if (!status) {
-            if (F_OK == mode) {
-                /*
-                 * If we didn't find a member then we must have gotten to the end
-                 * of the family.  As long as we found the first member(s) the
-                 * family exists.
-                 */
-                ret_value = membno > 0 ? TRUE : FALSE;
+	sprintf(member_name, name, membno);
+	status = H5F_low_access(memb_type, member_name, NULL, mode,
+				0 == membno ? key : NULL);
+
+	if (!status) {
+	    if (F_OK == mode) {
+		/*
+		 * If we didn't find a member then we must have gotten to the
+		 * end of the family.  As long as we found the first
+		 * member(s) the family exists.
+		 */
+		ret_value = membno > 0 ? TRUE : FALSE;
 		break;
 		
-            } else if (H5F_low_access(H5F_LOW_DFLT, member_name, F_OK, NULL)) {
-                /*
-                 * The file exists but didn't have the write access permissions.
-                 */
+	    } else if (H5F_low_access(memb_type, member_name,
+				      access_parms->u.fam.memb_access,
+				      F_OK, NULL)) {
+		/*
+		 * The file exists but didn't have the write access permissions.
+		 */
 		ret_value = FALSE;
 		break;
 		
-            } else {
-                /*
-                 * The file doesn't exist because we got to the end of the
-                 * family.
-                 */
+	    } else {
+		/*
+		 * The file doesn't exist because we got to the end of the
+		 * family.
+		 */
 		ret_value = TRUE;
 		break;
-            }
-        }
-        if (status < 0) {
-            HRETURN_ERROR(H5E_IO, H5E_CANTOPENFILE, FAIL,
-                          "access method failed for a member file");
-        }
+	    }
+	}
+	if (status < 0) {
+	    HRETURN_ERROR(H5E_IO, H5E_CANTOPENFILE, FAIL,
+			  "access method failed for a member file");
+	}
     }
 
     FUNC_LEAVE(ret_value);
diff --git a/src/H5Flow.c b/src/H5Flow.c
index edafc1f..6455571 100644
--- a/src/H5Flow.c
+++ b/src/H5Flow.c
@@ -23,6 +23,67 @@
 #define PABLO_MASK      H5F_low
 static hbool_t          interface_initialize_g = FALSE;
 #define INTERFACE_INIT NULL
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_low_class
+ *
+ * Purpose:	Given a driver identifier return the class pointer for that
+ *		low-level driver.
+ *
+ * Return:	Success:	A low-level driver class pointer.
+ *
+ *		Failure:	NULL
+ *
+ * Programmer:	Robb Matzke
+ *              Wednesday, February 18, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+const H5F_low_class_t *
+H5F_low_class (H5F_driver_t driver)
+{
+    const H5F_low_class_t	*type = NULL;
+    
+    FUNC_ENTER (H5F_low_class, NULL);
+
+    switch (driver) {
+    case H5F_LOW_STDIO:
+	type = H5F_LOW_STDIO_g;
+	break;
+
+    case H5F_LOW_SEC2:
+	type = H5F_LOW_SEC2_g;
+	break;
+
+    case H5F_LOW_CORE:
+	type = H5F_LOW_CORE_g;
+	break;
+
+#ifdef HAVE_PARALLEL
+    case H5F_LOW_MPIO:
+	type = H5F_LOW_MPIO_g;
+	break;
+#endif
+
+    case H5F_LOW_SPLIT:
+	type = H5F_LOW_SPLIT_g;
+	break;
+
+    case H5F_LOW_FAMILY:
+	type = H5F_LOW_FAMILY_g;
+	break;
+
+    default:
+	HRETURN_ERROR (H5E_IO, H5E_UNSUPPORTED, NULL,
+		       "unknown low-level driver");
+    }
+
+    FUNC_LEAVE (type);
+}
+	
 
 /*-------------------------------------------------------------------------
  * Function:    H5F_low_open
@@ -67,9 +128,10 @@ static hbool_t          interface_initialize_g = FALSE;
  *
  *-------------------------------------------------------------------------
  */
-H5F_low_t              *
-H5F_low_open(const H5F_low_class_t *type, const char *name, uintn flags,
-             H5F_search_t *key /*out */ )
+H5F_low_t *
+H5F_low_open(const H5F_low_class_t *type, const char *name,
+	     const H5F_access_t *access_parms, uintn flags,
+	     H5F_search_t *key/*out*/)
 {
     H5F_low_t              *lf = NULL;
 
@@ -78,7 +140,7 @@ H5F_low_open(const H5F_low_class_t *type, const char *name, uintn flags,
     assert(type && type->open);
     assert(name && *name);
 
-    if (NULL == (lf = (type->open) (name, flags, key))) {
+    if (NULL == (lf = (type->open) (name, access_parms, flags, key))) {
         HRETURN_ERROR(H5E_IO, H5E_CANTOPENFILE, NULL, "open failed");
     }
     lf->type = type;
@@ -114,13 +176,13 @@ H5F_low_open(const H5F_low_class_t *type, const char *name, uintn flags,
  *
  *-------------------------------------------------------------------------
  */
-H5F_low_t              *
-H5F_low_close(H5F_low_t *lf)
+H5F_low_t *
+H5F_low_close(H5F_low_t *lf, const H5F_access_t *access_parms)
 {
     FUNC_ENTER(H5F_low_close, NULL);
 
     if (lf) {
-        if ((lf->type->close) (lf) < 0) {
+        if ((lf->type->close) (lf, access_parms) < 0) {
             H5MM_xfree(lf);
             HRETURN_ERROR(H5E_IO, H5E_CLOSEERROR, NULL, "close failed");
         }
@@ -156,8 +218,8 @@ H5F_low_close(H5F_low_t *lf)
  *-------------------------------------------------------------------------
  */
 herr_t
-H5F_low_read(H5F_low_t *lf, const haddr_t *addr, size_t size,
-             uint8 *buf /*out */ )
+H5F_low_read(H5F_low_t *lf, const H5F_access_t *access_parms,
+	     const haddr_t *addr, size_t size, uint8 *buf/*out*/)
 {
     herr_t                  ret_value = FAIL;
 
@@ -168,7 +230,8 @@ H5F_low_read(H5F_low_t *lf, const haddr_t *addr, size_t size,
     assert(buf);
 
     if (lf->type->read) {
-        if ((ret_value = (lf->type->read) (lf, addr, size, buf)) < 0) {
+        if ((ret_value = (lf->type->read) (lf, access_parms, addr, size,
+					   buf)) < 0) {
             HRETURN_ERROR(H5E_IO, H5E_READERROR, ret_value, "read failed");
         }
     } else {
@@ -204,8 +267,8 @@ H5F_low_read(H5F_low_t *lf, const haddr_t *addr, size_t size,
  *-------------------------------------------------------------------------
  */
 herr_t
-H5F_low_write(H5F_low_t *lf, const haddr_t *addr, size_t size,
-              const uint8 *buf)
+H5F_low_write(H5F_low_t *lf, const H5F_access_t *access_parms,
+	      const haddr_t *addr, size_t size, const uint8 *buf)
 {
     herr_t                  ret_value = FAIL;
     haddr_t                 tmp_addr;
@@ -225,7 +288,8 @@ H5F_low_write(H5F_low_t *lf, const haddr_t *addr, size_t size,
     }
     /* Write the data */
     if (lf->type->write) {
-        if ((ret_value = (lf->type->write) (lf, addr, size, buf)) < 0) {
+        if ((ret_value = (lf->type->write) (lf, access_parms, addr, size,
+					    buf)) < 0) {
             HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, ret_value, "write failed");
         }
     } else {
@@ -260,7 +324,7 @@ H5F_low_write(H5F_low_t *lf, const haddr_t *addr, size_t size,
  *-------------------------------------------------------------------------
  */
 herr_t
-H5F_low_flush(H5F_low_t *lf)
+H5F_low_flush(H5F_low_t *lf, const H5F_access_t *access_parms)
 {
     haddr_t                 last_byte;
     uint8                   buf[1];
@@ -274,13 +338,13 @@ H5F_low_flush(H5F_low_t *lf)
     if (addr_defined(&(lf->eof)) && H5F_addr_gt(&(lf->eof), &last_byte)) {
         last_byte = lf->eof;
         last_byte.offset -= 1;
-        if (H5F_low_read(lf, &last_byte, 1, buf) >= 0) {
-            H5F_low_write(lf, &last_byte, 1, buf);
+        if (H5F_low_read(lf, access_parms, &last_byte, 1, buf) >= 0) {
+            H5F_low_write(lf, access_parms, &last_byte, 1, buf);
         }
     }
     /* Invoke the subclass the flush method */
     if (lf->type->flush) {
-        if ((lf->type->flush) (lf) < 0) {
+        if ((lf->type->flush) (lf, access_parms) < 0) {
             HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, FAIL,
                           "low level flush failed");
         }
@@ -372,8 +436,9 @@ H5F_low_size(H5F_low_t *lf, haddr_t *eof /*out */ )
  *-------------------------------------------------------------------------
  */
 hbool_t
-H5F_low_access(const H5F_low_class_t *type, const char *name, int mode,
-               H5F_search_t *key /*out */ )
+H5F_low_access(const H5F_low_class_t *type, const char *name,
+	       const H5F_access_t *access_parms, int mode,
+               H5F_search_t *key/*out*/)
 {
     hbool_t                 ret_value;
     struct stat             sb;
@@ -382,7 +447,7 @@ H5F_low_access(const H5F_low_class_t *type, const char *name, int mode,
     assert(type);
 
     if (type->access) {
-        ret_value = (type->access) (name, mode, key /*out */ );
+        ret_value = (type->access) (name, access_parms, mode, key /*out*/);
 
     } else {
         ret_value = (0 == access(name, mode) ? TRUE : FALSE);
@@ -418,7 +483,8 @@ H5F_low_access(const H5F_low_class_t *type, const char *name, int mode,
  *-------------------------------------------------------------------------
  */
 herr_t
-H5F_low_extend(H5F_low_t *lf, intn op, size_t size, haddr_t *addr /*out */ )
+H5F_low_extend(H5F_low_t *lf, const H5F_access_t *access_parms, intn op,
+	       size_t size, haddr_t *addr/*out*/)
 {
     FUNC_ENTER(H5F_low_alloc, FAIL);
 
@@ -427,7 +493,7 @@ H5F_low_extend(H5F_low_t *lf, intn op, size_t size, haddr_t *addr /*out */ )
     assert(addr);
 
     if (lf->type->extend) {
-        if ((lf->type->extend) (lf, op, size, addr /*out */ ) < 0) {
+        if ((lf->type->extend) (lf, access_parms, op, size, addr/*out*/) < 0) {
             HRETURN_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL,
                           "unable to extend file");
         }
diff --git a/src/H5Fmpio.c b/src/H5Fmpio.c
index 4c24621..c36500e 100644
--- a/src/H5Fmpio.c
+++ b/src/H5Fmpio.c
@@ -15,15 +15,16 @@
  *		  and to infer the access flags.  If the file is opened,
  *		  we close it without reading or writing it.
  *		- It is not possible within MPI-IO to determine whether or not
- *		  the names "file1" and "file2" refer to the same physical fileC
+ *		  the names "file1" and "file2" refer to the same physical file
  *		  (at least not without writing one and reading the other).
  *		  So we do what H5F_core_open() does: return a bogus device
  *		  number and a unique inode number.
  *		  This has the side effect that calling H5Fopen() twice
  *		  with the same name really does open the file twice
  *		  and the two handles don't communicate with each other,
- *		  resulting in trashing the file.  It also runs the (very small)
- *		  risk of having two unrelated names be seen as the same file.
+ *		  resulting in trashing the file.  It also runs the (very
+ *		  small) risk of having two unrelated names be seen as the
+ *		  same file.
  *
  *	H5F_mpio_open
  *		- should take MPI communicator and MPI info as parameters
@@ -57,32 +58,35 @@ static hbool_t          interface_initialize_g = FALSE;	/* rky??? */
 #define H5F_MPIO_DEV    0xfffe  /*pseudo dev for MPI-IO until we fix things */
 				/* Make sure this differs from H5F_CORE_DEV */
 
-static hbool_t          H5F_mpio_access(const char *name, int mode,
-                                       H5F_search_t *key /*out */ );
-static H5F_low_t       *H5F_mpio_open(const char *name, uintn flags,
-                                       H5F_search_t *key);
-static herr_t           H5F_mpio_close(H5F_low_t *lf);
-static herr_t           H5F_mpio_read(H5F_low_t *lf, const haddr_t *addr,
-				       size_t size, uint8 *buf);
-static herr_t           H5F_mpio_write(H5F_low_t *lf, const haddr_t *addr,
-				       size_t size, const uint8 *buf);
-static herr_t           H5F_mpio_flush(H5F_low_t *lf);
-static herr_t		H5F_MPIOff_to_haddr( MPI_Offset mpi_off, haddr_t *addr);
-static herr_t		H5F_haddr_to_MPIOff( haddr_t addr, MPI_Offset *mpi_off);
-
-const H5F_low_class_t   H5F_LOW_MPIO[1] =
-{
-    {
-        H5F_mpio_access,       /* access method                        */
-        H5F_mpio_open,         /* open method                          */
-        H5F_mpio_close,        /* close method                         */
-        H5F_mpio_read,         /* read method                          */
-        H5F_mpio_write,        /* write method                         */
-        H5F_mpio_flush,        /* flush method                         */
-        NULL                   /* extend method                        */
-    }};
+static hbool_t H5F_mpio_access(const char *name,
+			       const H5F_access_t *access_parms, int mode,
+			       H5F_search_t *key/*out*/);
+static H5F_low_t *H5F_mpio_open(const char *name,
+				const H5F_access_t *access_parms, uintn flags,
+				H5F_search_t *key/*out*/);
+static herr_t H5F_mpio_close(H5F_low_t *lf, const H5F_access_t *access_parms);
+static herr_t H5F_mpio_read(H5F_low_t *lf, const H5F_access_t *access_parms,
+			    const haddr_t *addr, size_t size,
+			    uint8 *buf/*out*/);
+static herr_t H5F_mpio_write(H5F_low_t *lf, const H5F_access_t *access_parms,
+			     const haddr_t *addr, size_t size,
+			     const uint8 *buf);
+static herr_t H5F_mpio_flush(H5F_low_t *lf, const H5F_access_t *access_parms);
+static herr_t H5F_MPIOff_to_haddr(MPI_Offset mpi_off, haddr_t *addr);
+static herr_t H5F_haddr_to_MPIOff(haddr_t addr, MPI_Offset *mpi_off);
+
+const H5F_low_class_t   H5F_LOW_MPIO_g[1] = {{
+    H5F_mpio_access,       /* access method                        */
+    H5F_mpio_open,         /* open method                          */
+    H5F_mpio_close,        /* close method                         */
+    H5F_mpio_read,         /* read method                          */
+    H5F_mpio_write,        /* write method                         */
+    H5F_mpio_flush,        /* flush method                         */
+    NULL                   /* extend method                        */
+}};
 
 ino_t mpio_inode_num = 0;      /* fake "inode" number */
+
 
 /*-------------------------------------------------------------------------
  * Function:    H5F_mpio_access
@@ -121,10 +125,14 @@ ino_t mpio_inode_num = 0;      /* fake "inode" number */
  *
  * Modifications:
  *
+ * 	Robb Matzke, 18 Feb 1998
+ *	Added the ACCESS_PARMS argument.
+ *
  *-------------------------------------------------------------------------
  */
 static hbool_t
-H5F_mpio_access(const char *name, int mode, H5F_search_t *key /*out */ )
+H5F_mpio_access(const char *name, const H5F_access_t *access_parms, int mode,
+		H5F_search_t *key/*out*/)
 {
     hbool_t		   ret_val = FALSE;
     MPI_File		   fh;
@@ -209,10 +217,15 @@ H5F_mpio_access(const char *name, int mode, H5F_search_t *key /*out */ )
  *
  * Modifications:
  *
+ * 	Robb Matzke, 18 Feb 1998
+ *	Added the ACCESS_PARMS argument.  Moved some error checking here from
+ *	elsewhere.
+ *
  *-------------------------------------------------------------------------
  */
-static H5F_low_t       *
-H5F_mpio_open(const char *name, uintn flags, H5F_search_t *key /*out */ )
+static H5F_low_t *
+H5F_mpio_open(const char *name, const H5F_access_t *access_parms, uintn flags,
+	      H5F_search_t *key/*out*/)
 {
     H5F_low_t              *lf = NULL;
     MPI_File                fh;
@@ -226,9 +239,22 @@ H5F_mpio_open(const char *name, uintn flags, H5F_search_t *key /*out */ )
     fprintf(stdout, "Entering H5F_mpio_open name=%s flags=%x\n", name, flags );
 #endif
 
+    switch (access_parms->u.mpio.access_mode){
+    case H5ACC_INDEPENDENT:
+	/*void*/
+	break;
+	
+    case H5ACC_COLLECTIVE:
+	HRETURN_ERROR(H5E_IO, H5E_UNSUPPORTED, NULL,
+		      "collective I/O is not supported yet");
+
+    default:
+	HRETURN_ERROR(H5E_IO, H5E_BADVALUE, NULL, "invalid file access mode");
+    }
+
     /* convert HDF5 flags to MPI-IO flags */
     /* some combinations are illegal; let MPI-IO figure it out */
-    mpi_amode  = (flags&H5F_ACC_WRITE) ? MPI_MODE_RDWR : MPI_MODE_RDONLY;
+    mpi_amode  = (flags&H5F_ACC_RDWR) ? MPI_MODE_RDWR : MPI_MODE_RDONLY;
     if (flags&H5F_ACC_CREAT)	mpi_amode |= MPI_MODE_CREATE;
     if (flags&H5F_ACC_EXCL)	mpi_amode |= MPI_MODE_EXCL;
 
@@ -303,10 +329,13 @@ H5F_mpio_open(const char *name, uintn flags, H5F_search_t *key /*out */ )
  *
  * Modifications:
  *
+ * 	Robb Matzke, 18 Feb 1998
+ *	Added the ACCESS_PARMS argument.
+ *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F_mpio_close(H5F_low_t *lf)
+H5F_mpio_close(H5F_low_t *lf, const H5F_access_t *access_parms)
 {
     int                     mpierr;
     char                    mpierrmsg[MPI_MAX_ERROR_STRING];
@@ -351,10 +380,14 @@ H5F_mpio_close(H5F_low_t *lf)
  *
  * Modifications:
  *
+ * 	Robb Matzke, 18 Feb 1998
+ *	Added the ACCESS_PARMS argument.
+ *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F_mpio_read(H5F_low_t *lf, const haddr_t *addr, size_t size, uint8 *buf)
+H5F_mpio_read(H5F_low_t *lf, const H5F_access_t *access_parms,
+	      const haddr_t *addr, size_t size, uint8 *buf/*out*/)
 {
     MPI_Offset              mpi_off;
     int                     size_i, bytes_read, n;
@@ -449,11 +482,15 @@ H5F_mpio_read(H5F_low_t *lf, const haddr_t *addr, size_t size, uint8 *buf)
  *
  * Modifications:
  *
+ * 	Robb Matzke, 18 Feb 1998
+ *	Added the ACCESS_PARMS argument.
+ *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F_mpio_write(H5F_low_t *lf, const haddr_t *addr, size_t size,
-                const uint8 *buf)
+H5F_mpio_write(H5F_low_t *lf, const H5F_access_t *access_parms,
+	       const haddr_t *addr, size_t size,
+	       const uint8 *buf)
 {
     MPI_Offset              mpi_off;
     MPI_Status              mpi_stat;
@@ -511,10 +548,13 @@ H5F_mpio_write(H5F_low_t *lf, const haddr_t *addr, size_t size,
  *
  * Modifications:
  *
+ * 	Robb Matzke, 18 Feb 1998
+ *	Added the ACCESS_PARMS argument.
+ *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F_mpio_flush(H5F_low_t *lf)
+H5F_mpio_flush(H5F_low_t *lf, const H5F_access_t *access_parms)
 {
     int                     mpierr;
     char                    mpierrmsg[MPI_MAX_ERROR_STRING];
diff --git a/src/H5Fprivate.h b/src/H5Fprivate.h
index 14c7e72..7daf090 100644
--- a/src/H5Fprivate.h
+++ b/src/H5Fprivate.h
@@ -53,13 +53,11 @@
 #define H5F_SIZEOF_SIZE(F)	((F)->shared->create_parms.sizeof_size)
 
 /*
- * File open flags.
+ * Private file open flags.
  */
-#define H5F_ACC_WRITE	0x0001	/* Open file for read/write access	  */
-#define H5F_ACC_CREAT	0x0002	/* Create non-existing files		  */
-#define H5F_ACC_EXCL	0x0004	/* Fail if file exists			  */
-#define H5F_ACC_TRUNC	0x0008	/* Truncate existing file	  */
-#define H5F_ACC_DEBUG	0x00010 /* Print debug info			  */
+#define H5F_ACC_PUBLIC_FLAGS 	0x00ff
+
+#define H5F_ACC_CREAT	0x0100	/* Create non-existing files		  */
 
 /*
  * Encode and decode macros for file meta-data.
@@ -204,8 +202,10 @@
 
 #define NBYTEENCODE(d, s, n) {	 HDmemcpy(d,s,n); p+=n }
 
-/* Note! the NBYTEDECODE macro is backwards from the memcpy() routine, */
-/*	in the spirit of the other DECODE macros */
+/*
+ * Note:  the NBYTEDECODE macro is backwards from the memcpy() routine, in
+ *	  the spirit of the other DECODE macros.
+ */
 #define NBYTEDECODE(s, d, n) {	 HDmemcpy(d,s,n); p+=n }
 
 /*
@@ -228,11 +228,35 @@ typedef struct H5F_create_t {
  * File-access template.
  */
 typedef struct H5F_access_t {
-    uintn	access_mode;	/* file access mode                     */
+    H5F_driver_t driver;	/* Low level file driver		*/
+    union {
+
+	/* Properties for in-core files */
+	struct {
+	    size_t increment;		/*amount by which to increment size*/
+	} core;
+
+	/* Properties for file families */
+	struct {
+	    struct H5F_access_t *memb_access; /*plist for the members*/
+	} fam;
+
+	/* Properties for the split driver */
+	struct {
+	    struct H5F_access_t *meta_access; /*plist for meta file	*/
+	    struct H5F_access_t *raw_access;  /*plist for raw data file	*/
+	} split;
+	
 #ifdef HAVE_PARALLEL
-    MPI_Comm    comm;           /* communicator for file access         */
-    MPI_Info    info;           /* optional info for MPI-IO             */
-#endif /*HAVE_PARALLEL*/
+	/* Properties for parallel I/O */
+	struct {
+	    uintn access_mode;	/* independent or collective variety?   */
+	    MPI_Comm    comm;   /* communicator for file access         */
+	    MPI_Info    info;   /* optional info for MPI-IO             */
+	} mpio;
+#endif
+	
+    } u;
 } H5F_access_t;
 
 /*
@@ -255,18 +279,27 @@ typedef enum {
  * Define the low-level file interface.
  */
 typedef struct H5F_low_class_t {
-    hbool_t	(*access)(const char *, int, H5F_search_t *);
-    struct H5F_low_t *(*open)(const char *, uintn, H5F_search_t *);
-    herr_t	(*close)(struct H5F_low_t *);
-    herr_t	(*read)(struct H5F_low_t *, const haddr_t *, size_t, uint8 *);
-    herr_t	(*write)(struct H5F_low_t *, const haddr_t *, size_t,
-			 const uint8 *);
-    herr_t	(*flush)(struct H5F_low_t *);
-    herr_t	(*extend)(struct H5F_low_t *, intn, size_t, haddr_t *);
+    hbool_t	(*access)(const char *name, const H5F_access_t *access_parms,
+			  int mode, H5F_search_t *key/*out*/);
+    struct H5F_low_t *(*open)(const char *name,
+			      const H5F_access_t *access_parms, uintn flags,
+			      H5F_search_t *key/*out*/);
+    herr_t	(*close)(struct H5F_low_t *lf,
+			 const H5F_access_t *access_parms);
+    herr_t	(*read)(struct H5F_low_t *lf, const H5F_access_t *access_parms,
+			const haddr_t *addr, size_t size, uint8 *buf);
+    herr_t	(*write)(struct H5F_low_t *lf,
+			 const H5F_access_t *access_parms,
+			 const haddr_t *addr, size_t size, const uint8 *buf);
+    herr_t	(*flush)(struct H5F_low_t *lf,
+			 const H5F_access_t *access_parms);
+    herr_t	(*extend)(struct H5F_low_t *lf,
+			  const H5F_access_t *access_parms,
+			  intn op, size_t size, haddr_t *addr);
 } H5F_low_class_t;
 
 typedef struct H5F_low_t {
-    const H5F_low_class_t *type;	/* What type of file is this?		*/
+    const H5F_low_class_t *type;/* What type of file is this?		*/
     haddr_t		eof;	/* Address of logical end-of-file	*/
     union {
 
@@ -292,14 +325,22 @@ typedef struct H5F_low_t {
 	struct {
 	    int		fd;	/* The unix file descriptor		*/
 	    H5F_fileop_t op;	/* Previous file operation		*/
+#ifdef HAVE_LSEEK64
+	    off64_t	cur;	/* Current file position		*/
+#else
 	    off_t	cur;	/* Current file position		*/
+#endif
 	} sec2;
 
 	/* Posix stdio */
 	struct {
 	    FILE	*f;	/* Posix stdio file			*/
 	    H5F_fileop_t op;	/* Previous file operation		*/
+#ifdef HAVE_FSEEK64
+	    long long	cur;	/* Current file position		*/
+#else
 	    off_t	cur;	/* Current file position		*/
+#endif
 	} stdio;
 
 	/* In-core temp file */
@@ -323,13 +364,13 @@ typedef struct H5F_low_t {
 #ifndef H5F_LOW_DFLT
 #  define H5F_LOW_DFLT	H5F_LOW_STDIO	/* The default type	  */
 #endif
-extern const H5F_low_class_t H5F_LOW_SEC2[];	/* Posix section 2	*/
-extern const H5F_low_class_t H5F_LOW_STDIO[];	/* Posix stdio		*/
-extern const H5F_low_class_t H5F_LOW_CORE[];	/* In-core temp file	*/
-extern const H5F_low_class_t H5F_LOW_FAM[];	/* File family		*/
-extern const H5F_low_class_t H5F_LOW_SPLIT[];	/* Split meta/raw data	*/
+extern const H5F_low_class_t H5F_LOW_SEC2_g[];	/* Posix section 2	*/
+extern const H5F_low_class_t H5F_LOW_STDIO_g[];	/* Posix stdio		*/
+extern const H5F_low_class_t H5F_LOW_CORE_g[];	/* In-core temp file	*/
+extern const H5F_low_class_t H5F_LOW_FAMILY_g[];/* File family		*/
+extern const H5F_low_class_t H5F_LOW_SPLIT_g[];	/* Split meta/raw data	*/
 #ifdef HAVE_PARALLEL
-  extern const H5F_low_class_t H5F_LOW_MPIO[];	/* MPI-IO		*/
+extern const H5F_low_class_t H5F_LOW_MPIO_g[];	/* MPI-IO		*/
 #endif
 
 /*
@@ -349,9 +390,7 @@ typedef struct H5F_file_t {
     haddr_t	hdf5_eof;	/* Relative addr of end of all hdf5 data*/
     struct H5AC_t *cache;	/* The object cache			*/
     H5F_create_t create_parms;	/* File-creation template		*/
-#ifdef HAVE_PARALLEL
     H5F_access_t access_parms;  /* File-access template	*/
-#endif
     struct H5G_entry_t *root_ent; /* Root symbol table entry		*/
 } H5F_file_t;
 
@@ -411,18 +450,20 @@ struct H5O_layout_t;		/*forward decl for prototype arguments */
 
 /* library variables */
 extern const H5F_create_t H5F_create_dflt;
-extern const H5F_access_t H5F_access_dflt;
+extern H5F_access_t H5F_access_dflt;
 
 /* Private functions, not part of the publicly documented API */
+herr_t H5F_init_interface(void);
 void H5F_encode_length_unusual(const H5F_t *f, uint8 **p, uint8 *l);
-H5F_t *H5F_open(const H5F_low_class_t *type, const char *name, uintn flags,
-		const H5F_create_t *create_parms, const H5F_access_t *access_parms);
+H5F_t *H5F_open(const char *name, uintn flags,
+		const H5F_create_t *create_parms,
+		const H5F_access_t *access_parms);
 herr_t H5F_close(H5F_t *f);
 herr_t H5F_debug(H5F_t *f, const haddr_t *addr, FILE * stream, intn indent,
 		 intn fwidth);
 
 /* Functions that operate on array storage */
-herr_t H5F_arr_create(H5F_t *f, struct H5O_layout_t *layout /*in,out */ );
+herr_t H5F_arr_create(H5F_t *f, struct H5O_layout_t *layout /*in,out*/);
 herr_t H5F_arr_read (H5F_t *f, const struct H5O_layout_t *layout,
 		     const size_t _hslab_size[], const size_t mem_size[],
 		     const size_t mem_offset[], const size_t file_offset[],
@@ -433,7 +474,7 @@ herr_t H5F_arr_write (H5F_t *f, const struct H5O_layout_t *layout,
 		      const void *_buf);
 
 /* Functions that operate on indexed storage */
-herr_t H5F_istore_create(H5F_t *f, struct H5O_layout_t *layout /*in,out */ );
+herr_t H5F_istore_create(H5F_t *f, struct H5O_layout_t *layout /*in,out*/);
 herr_t H5F_istore_read(H5F_t *f, const struct H5O_layout_t *layout,
 		       const size_t offset[], const size_t size[],
 		       void *buf /*out */ );
@@ -447,19 +488,23 @@ herr_t H5F_block_write(H5F_t *f, const haddr_t *addr, size_t size,
 		       const void *buf);
 
 /* Functions that operate directly on low-level files */
-herr_t H5F_low_extend(H5F_low_t *lf, intn op, size_t size, haddr_t *addr);
+const H5F_low_class_t *H5F_low_class (H5F_driver_t driver);
+herr_t H5F_low_extend(H5F_low_t *lf, const H5F_access_t *access_parms,
+		      intn op, size_t size, haddr_t *addr);
 herr_t H5F_low_seteof(H5F_low_t *lf, const haddr_t *addr);
 hbool_t H5F_low_access(const H5F_low_class_t *type, const char *name,
-		       int mode, H5F_search_t *key);
+		       const H5F_access_t *access_parms, int mode,
+		       H5F_search_t *key);
 H5F_low_t *H5F_low_open(const H5F_low_class_t *type, const char *name,
-			uintn flags, H5F_search_t *key);
-H5F_low_t *H5F_low_close(H5F_low_t *lf);
+			const H5F_access_t *access_parms, uintn flags,
+			H5F_search_t *key);
+H5F_low_t *H5F_low_close(H5F_low_t *lf, const H5F_access_t *access_parms);
 size_t H5F_low_size(H5F_low_t *lf, haddr_t *addr);
-herr_t H5F_low_read(H5F_low_t *lf, const haddr_t *addr, size_t size,
-		    uint8 *buf);
-herr_t H5F_low_write(H5F_low_t *lf, const haddr_t *addr, size_t size,
-		     const uint8 *buf);
-herr_t H5F_low_flush(H5F_low_t *lf);
+herr_t H5F_low_read(H5F_low_t *lf, const H5F_access_t *access_parms,
+		    const haddr_t *addr, size_t size, uint8 *buf);
+herr_t H5F_low_write(H5F_low_t *lf, const H5F_access_t *access_parms,
+		     const haddr_t *addr, size_t size, const uint8 *buf);
+herr_t H5F_low_flush(H5F_low_t *lf, const H5F_access_t *access_parms);
 
 /* Functions that operate on addresses */
 #define H5F_addr_eq(A1,A2) (H5F_addr_cmp(A1,A2)==0)
diff --git a/src/H5Fpublic.h b/src/H5Fpublic.h
index 538b07b..51d4d56 100644
--- a/src/H5Fpublic.h
+++ b/src/H5Fpublic.h
@@ -20,15 +20,50 @@
 #include <H5public.h>
 #include <H5Apublic.h>
 
-/* file access codes */
-#define H5ACC_DEFAULT       0x0000/*use in H5Fopen & H5Fcreate to open a file with default access*/
-#define H5ACC_WRITE         0x0001/*use in H5Fopen to open a file with write access*/
-#define H5ACC_OVERWRITE     0x0002/*use in H5Fcreate truncate an existing file*/
-#ifdef HAVE_PARALLEL
-#define H5ACC_INDEPENDENT   0x0010/*use in H5Cset_mpi for MPI independent access*/
-#define H5ACC_COLLECTIVE    0x0011/*use in H5Cset_mpi for MPI collective access*/
+/*
+ * These are the bits that can be passed to the `flags' argument of
+ * H5Fcreate() and H5Fopen(). Use the bit-wise OR operator (|) to combine
+ * them as needed.
+ */
+#define H5F_ACC_RDONLY	0x0000	/*absence of write implies read only	*/
+#define H5F_ACC_RDWR	0x0001	/*open file for reading and writing	*/
+#define H5F_ACC_TRUNC	0x0002	/*overwrite existing files during create*/
+#define H5F_ACC_EXCL	0x0004	/*create fails if file already exists	*/
+#define H5F_ACC_DEBUG	0x0008  /*print debug info			*/
+
+
+#ifdef LATER
+/*
+ * These are here temporarily for backward compatibility with version
+ * 5.1.0.0a and should eventually be removed since they violate the naming
+ * scheme.
+ */
+#define H5ACC_DEFAULT	H5F_ACC_RDONLY
+#define H5ACC_WRITE	H5F_ACC_RDWR
+#define H5ACC_OVERWRITE	H5F_ACC_TRUNC
 #endif
 
+/*
+ * Low-level file drivers.  These values are returned by H5Cget_file_driver()
+ * and are set by the various H5Cset_...() functions that set file driver
+ * properties.
+ */
+typedef enum H5F_driver_t {
+    H5F_LOW_ERROR	= -1,	/*error return value			*/
+    H5F_LOW_STDIO	= 0,	/*use functions declared in stdio.h	*/
+    H5F_LOW_SEC2	= 1, 	/*use functions declared in unistd.h	*/
+    H5F_LOW_MPIO	= 2,	/*use indep or collective MPI-IO	*/
+    H5F_LOW_CORE	= 3,	/*use malloc() and free()		*/
+    H5F_LOW_SPLIT	= 4,	/*separate meta data from raw data	*/
+    H5F_LOW_FAMILY	= 5, 	/*split addr space over many files	*/
+} H5F_driver_t;
+
+
+/* Parallel styles passed to H5Cset_mpi() */
+#ifdef HAVE_PARALLEL
+#  define H5ACC_INDEPENDENT 0x0010	/*MPI independent access	*/
+#  define H5ACC_COLLECTIVE  0x0011	/*MPI collective access		*/
+#endif
 
 #ifdef __cplusplus
 extern "C" {
@@ -41,6 +76,7 @@ hid_t H5Fcreate (const char *filename, uintn flags, hid_t create_template,
 hid_t H5Fopen (const char *filename, uintn flags, hid_t access_template);
 herr_t H5Fclose (hid_t fid);
 hid_t H5Fget_create_template (hid_t fid);
+hid_t H5Fget_access_template (hid_t file_id);
 
 #ifdef __cplusplus
 }
diff --git a/src/H5Fsec2.c b/src/H5Fsec2.c
index 5fb3b08..dd0ab0f 100644
--- a/src/H5Fsec2.c
+++ b/src/H5Fsec2.c
@@ -1,18 +1,18 @@
 /*
  * Copyright (C) 1997 NCSA
- *                    All rights reserved.
+ *		      All rights reserved.
  *
  * Programmer: Robb Matzke <matzke@llnl.gov>
- *             Wednesday, October 22, 1997
+ *	       Wednesday, October 22, 1997
  *
  * Purpose:    This is the Posix section-2 I/O subclass of H5Flow.
  *
  * Notes:      This driver keeps track of its own file position in order to
- *             minimize the number of calls to lseek().  We assume that
- *             opening a file sets the current file position to the beginning
- *             and that read() and write() modify the file position as
- *             expected when they return successfully (unsuccessful return
- *             leaves the file position undefined).
+ *	       minimize the number of calls to lseek().	 We assume that
+ *	       opening a file sets the current file position to the beginning
+ *	       and that read() and write() modify the file position as
+ *	       expected when they return successfully (unsuccessful return
+ *	       leaves the file position undefined).
  */
 #include <H5private.h>
 #include <H5Eprivate.h>
@@ -22,66 +22,70 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 
-#define PABLO_MASK      H5F_sec2
-static hbool_t          interface_initialize_g = FALSE;
-#define INTERFACE_INIT  NULL
+#define PABLO_MASK	H5F_sec2
+static hbool_t		interface_initialize_g = FALSE;
+#define INTERFACE_INIT	NULL
 
-static H5F_low_t       *H5F_sec2_open(const char *name, uintn flags, H5F_search_t *);
-static herr_t           H5F_sec2_close(H5F_low_t *lf);
-static herr_t           H5F_sec2_read(H5F_low_t *lf, const haddr_t *addr, size_t size,
-                                      uint8 *buf);
-static herr_t           H5F_sec2_write(H5F_low_t *lf, const haddr_t *addr, size_t size,
-                                       const uint8 *buf);
+static H5F_low_t *H5F_sec2_open(const char *name,
+				const H5F_access_t *access_parms, uintn flags,
+				H5F_search_t *key/*out*/);
+static herr_t H5F_sec2_close(H5F_low_t *lf, const H5F_access_t *access_parms);
+static herr_t H5F_sec2_read(H5F_low_t *lf, const H5F_access_t *access_parms,
+			    const haddr_t *addr, size_t size,
+			    uint8 *buf/*out*/);
+static herr_t H5F_sec2_write(H5F_low_t *lf, const H5F_access_t *access_parms,
+			     const haddr_t *addr, size_t size,
+			     const uint8 *buf);
+
+const H5F_low_class_t	H5F_LOW_SEC2_g[1] = {{
+    NULL,			/* access method			*/
+    H5F_sec2_open,		/* open method				*/
+    H5F_sec2_close,		/* close method				*/
+    H5F_sec2_read,		/* read method				*/
+    H5F_sec2_write,		/* write method				*/
+    NULL,			/* flush method				*/
+    NULL,			/* extend method			*/
+}};
 
-const H5F_low_class_t   H5F_LOW_SEC2[1] =
-{
-    {
-        NULL,                   /* access method                        */
-        H5F_sec2_open,          /* open method                          */
-        H5F_sec2_close,         /* close method                         */
-        H5F_sec2_read,          /* read method                          */
-        H5F_sec2_write,         /* write method                         */
-        NULL,                   /* flush method                         */
-        NULL,                   /* extend method                        */
-    }};
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_sec2_open
+ * Function:	H5F_sec2_open
  *
- * Purpose:     Opens a file with name NAME.  The FLAGS are a bit field with
- *              the possible values defined in H5F_low_open().
+ * Purpose:	Opens a file with name NAME.  The FLAGS are a bit field with
+ *		the possible values defined in H5F_low_open().
  *
  * Errors:
- *              IO        CANTOPENFILE  Open failed. 
+ *		IO	  CANTOPENFILE	Open failed. 
  *
- * Return:      Success:        Low-level file pointer
+ * Return:	Success:	Low-level file pointer
  *
- *              Failure:        NULL
+ *		Failure:	NULL
  *
- * Programmer:  Robb Matzke
- *              Wednesday, October 22, 1997
+ * Programmer:	Robb Matzke
+ *		Wednesday, October 22, 1997
  *
  * Modifications:
  *
  *-------------------------------------------------------------------------
  */
-static H5F_low_t       *
-H5F_sec2_open(const char *name, uintn flags, H5F_search_t *key /*out */ )
+static H5F_low_t *
+H5F_sec2_open(const char *name, const H5F_access_t *access_parms, uintn flags,
+	      H5F_search_t *key/*out*/)
 {
-    uintn                   oflags;
-    H5F_low_t              *lf = NULL;
-    int                     fd;
-    struct stat             sb;
+    uintn		    oflags;
+    H5F_low_t		   *lf = NULL;
+    int			    fd;
+    struct stat		    sb;
 
     FUNC_ENTER(H5F_sec2_open, NULL);
 
-    oflags = (flags & H5F_ACC_WRITE) ? O_RDWR : O_RDONLY;
+    oflags = (flags & H5F_ACC_RDWR) ? O_RDWR : O_RDONLY;
     oflags |= (flags & H5F_ACC_CREAT) ? O_CREAT : 0;
     oflags |= (flags & H5F_ACC_EXCL) ? O_EXCL : 0;
     oflags |= (flags & H5F_ACC_TRUNC) ? O_TRUNC : 0;
 
     if ((fd = open(name, oflags, 0666)) < 0) {
-        HRETURN_ERROR(H5E_IO, H5E_CANTOPENFILE, NULL, "open failed");
+	HRETURN_ERROR(H5E_IO, H5E_CANTOPENFILE, NULL, "open failed");
     }
     lf = H5MM_xcalloc(1, sizeof(H5F_low_t));
     lf->u.sec2.fd = fd;
@@ -91,38 +95,38 @@ H5F_sec2_open(const char *name, uintn flags, H5F_search_t *key /*out */ )
     lf->eof.offset = sb.st_size;
 
     if (key) {
-        key->dev = sb.st_dev;
-        key->ino = sb.st_ino;
+	key->dev = sb.st_dev;
+	key->ino = sb.st_ino;
     }
     FUNC_LEAVE(lf);
 }
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_sec2_close
+ * Function:	H5F_sec2_close
  *
- * Purpose:     Closes a file.
+ * Purpose:	Closes a file.
  *
  * Errors:
- *              IO        CLOSEERROR    Close failed. 
+ *		IO	  CLOSEERROR	Close failed. 
  *
- * Return:      Success:        SUCCEED
+ * Return:	Success:	SUCCEED
  *
- *              Failure:        FAIL
+ *		Failure:	FAIL
  *
- * Programmer:  Robb Matzke
- *              Wednesday, October 22, 1997
+ * Programmer:	Robb Matzke
+ *		Wednesday, October 22, 1997
  *
  * Modifications:
  *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F_sec2_close(H5F_low_t *lf)
+H5F_sec2_close(H5F_low_t *lf, const H5F_access_t *access_parms)
 {
     FUNC_ENTER(H5F_sec2_close, FAIL);
 
     if (close(lf->u.sec2.fd) < 0) {
-        HRETURN_ERROR(H5E_IO, H5E_CLOSEERROR, FAIL, "close failed");
+	HRETURN_ERROR(H5E_IO, H5E_CLOSEERROR, FAIL, "close failed");
     }
     lf->u.sec2.fd = -1;
 
@@ -130,148 +134,181 @@ H5F_sec2_close(H5F_low_t *lf)
 }
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_sec2_read
+ * Function:	H5F_sec2_read
  *
- * Purpose:     Reads SIZE bytes beginning at address ADDR in file LF and
- *              places them in buffer BUF.  Reading past the logical or
- *              physical end of file returns zeros instead of failing.
+ * Purpose:	Reads SIZE bytes beginning at address ADDR in file LF and
+ *		places them in buffer BUF.  Reading past the logical or
+ *		physical end of file returns zeros instead of failing.
  *
  * Errors:
- *              IO        READERROR     Read failed. 
- *              IO        SEEKERROR     Lseek failed. 
+ *		IO	  READERROR	Read failed. 
+ *		IO	  SEEKERROR	Lseek failed. 
  *
- * Return:      Success:        SUCCEED
+ * Return:	Success:	SUCCEED
  *
- *              Failure:        FAIL
+ *		Failure:	FAIL
  *
- * Programmer:  Robb Matzke
- *              Wednesday, October 22, 1997
+ * Programmer:	Robb Matzke
+ *		Wednesday, October 22, 1997
  *
  * Modifications:
  *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F_sec2_read(H5F_low_t *lf, const haddr_t *addr, size_t size, uint8 *buf)
+H5F_sec2_read(H5F_low_t *lf, const H5F_access_t *access_parms,
+	      const haddr_t *addr, size_t size, uint8 *buf)
 {
-    ssize_t                 n;
-    off_t                   offset;
+    ssize_t		n;
+    uint64		mask;
+#ifdef HAVE_LSEEK64
+    off64_t		offset;
+#else
+    off_t		offset;
+#endif
 
     FUNC_ENTER(H5F_sec2_read, FAIL);
 
     /* Check for overflow */
-    offset = addr->offset; /*FIX_ME*/
-    assert("address overflowed" && offset == addr->offset);
-    assert("overflow" && offset + size >= offset);
+    mask = (uint64)1 << (8*sizeof(offset)-1);
+    if (addr->offset >= mask ||
+	addr->offset+size < addr->offset ||
+	addr->offset+size >= mask) {
+	HRETURN_ERROR (H5E_IO, H5E_OVERFLOW, FAIL, "file address overflowed");
+    }
+#ifdef HAVE_LSEEK64
+    offset = (off64_t)(addr->offset); /*checked for overflow*/
+#else
+    offset = (off_t)(addr->offset); /*checked for overflow*/
+#endif
 
     /* Check easy cases */
-    if (0 == size)
-        HRETURN(SUCCEED);
+    if (0 == size) HRETURN(SUCCEED);
     if (offset >= lf->eof.offset) {
-        HDmemset(buf, 0, size);
-        HRETURN(SUCCEED);
+	HDmemset(buf, 0, size);
+	HRETURN(SUCCEED);
     }
+
     /*
      * Optimize seeking.  If that optimization is disabled then always call
      * lseek().
      */
     if (!H5F_OPT_SEEK ||
-        lf->u.sec2.op == H5F_OP_UNKNOWN ||
-        lf->u.sec2.cur != offset) {
-        if (lseek(lf->u.sec2.fd, offset, SEEK_SET) < 0) {
-            HRETURN_ERROR(H5E_IO, H5E_SEEKERROR, FAIL, "lseek failed");
-        }
-        lf->u.sec2.cur = offset;
+	lf->u.sec2.op == H5F_OP_UNKNOWN ||
+	lf->u.sec2.cur != offset) {
+	if (lseek(lf->u.sec2.fd, offset, SEEK_SET) < 0) {
+	    HRETURN_ERROR(H5E_IO, H5E_SEEKERROR, FAIL, "lseek failed");
+	}
+	lf->u.sec2.cur = offset;
     }
+    
     /*
      * Read zeros past the logical end of file (physical is handled below)
      */
     if ((size_t) offset + size > lf->eof.offset) {
-        size_t                  nbytes = (size_t) offset + size - lf->eof.offset;
-        HDmemset(buf + size - nbytes, 0, nbytes);
-        size -= nbytes;
+	size_t nbytes = (size_t)offset + size - lf->eof.offset;
+	HDmemset(buf + size - nbytes, 0, nbytes);
+	size -= nbytes;
     }
+    
     /*
      * Read the data.  If a read error occurs then set the last file operation
      * to UNKNOWN because the file position isn't guaranteed by Posix.
      */
     if ((n = read(lf->u.sec2.fd, buf, size)) < 0) {
-        lf->u.sec2.op = H5F_OP_UNKNOWN;
-        HRETURN_ERROR(H5E_IO, H5E_READERROR, FAIL, "read failed");
+	lf->u.sec2.op = H5F_OP_UNKNOWN;
+	HRETURN_ERROR(H5E_IO, H5E_READERROR, FAIL, "read failed");
     } else if (n < size) {
-        HDmemset(buf + n, 0, size - n);
+	HDmemset(buf + n, 0, size - n);
     }
+
     /*
-     * Update the file position with the number of bytes actually read.  This
+     * Update the file position with the number of bytes actually read.	 This
      * might be different than the number requested.
      */
     lf->u.sec2.op = H5F_OP_READ;
     lf->u.sec2.cur = offset + n;
-    assert("address overflowed" && lf->u.sec2.cur >= offset);
 
     FUNC_LEAVE(SUCCEED);
 }
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_sec2_write
+ * Function:	H5F_sec2_write
  *
- * Purpose:     Writes SIZE bytes from the beginning of BUF into file LF at
- *              file address ADDR.
+ * Purpose:	Writes SIZE bytes from the beginning of BUF into file LF at
+ *		file address ADDR.
  *
  * Errors:
- *              IO        SEEKERROR     Lseek failed. 
- *              IO        WRITEERROR    Write failed. 
+ *		IO	  SEEKERROR	Lseek failed. 
+ *		IO	  WRITEERROR	Write failed. 
  *
- * Return:      Success:        SUCCEED
+ * Return:	Success:	SUCCEED
  *
- *              Failure:        FAIL
+ *		Failure:	FAIL
  *
- * Programmer:  Robb Matzke
- *              Wednesday, October 22, 1997
+ * Programmer:	Robb Matzke
+ *		Wednesday, October 22, 1997
  *
  * Modifications:
  *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F_sec2_write(H5F_low_t *lf, const haddr_t *addr, size_t size,
-               const uint8 *buf)
+H5F_sec2_write(H5F_low_t *lf, const H5F_access_t *access_parms,
+	       const haddr_t *addr, size_t size, const uint8 *buf)
 {
-    off_t                   offset;
+    uint64	mask;
+    ssize_t	n;
+#ifdef HAVE_LSEEK64
+    off64_t	offset;
+#else
+    off_t	offset;
+#endif
 
     FUNC_ENTER(H5F_sec2_write, FAIL);
 
     /* Check for overflow */
-    offset = addr->offset; /*FIX_ME*/
-    assert("address overflowed" && offset == addr->offset);
-    assert("overflow" && offset + size >= offset);
+    mask = (uint64)1 << (8*sizeof(offset)-1);
+    if (addr->offset >= mask ||
+	addr->offset+size < addr->offset ||
+	addr->offset+size >= mask) {
+	HRETURN_ERROR (H5E_IO, H5E_OVERFLOW, FAIL, "file address overflowed");
+    }
+#ifdef HAVE_LSEEK64
+    offset = (off64_t)(addr->offset); /*checked for overflow*/
+    n = (off64_t)size; /*checked for overflow*/
+#else
+    offset = (off_t)(addr->offset); /*checked for overflow*/
+    n = (off_t)size; /*checked for overflow*/
+#endif
 
     /*
      * Optimize seeking. If that optimization is disabled then always call
      * lseek().
      */
     if (!H5F_OPT_SEEK ||
-        lf->u.sec2.op == H5F_OP_UNKNOWN ||
-        lf->u.sec2.cur != offset) {
-        if (lseek(lf->u.sec2.fd, offset, SEEK_SET) < 0) {
-            HRETURN_ERROR(H5E_IO, H5E_SEEKERROR, FAIL, "lseek failed");
-        }
-        lf->u.sec2.cur = offset;
+	lf->u.sec2.op == H5F_OP_UNKNOWN ||
+	lf->u.sec2.cur != offset) {
+	if (lseek(lf->u.sec2.fd, offset, SEEK_SET) < 0) {
+	    HRETURN_ERROR(H5E_IO, H5E_SEEKERROR, FAIL, "lseek failed");
+	}
+	lf->u.sec2.cur = offset;
     }
+
     /*
      * Write the data to the file.  If the write failed then set the
      * operation back to UNKNOWN since Posix doesn't gurantee its value.
      */
-    if (size != write(lf->u.sec2.fd, buf, size)) {
-        lf->u.sec2.op = H5F_OP_UNKNOWN;
-        HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "write failed");
+    if (n != write(lf->u.sec2.fd, buf, size)) {
+	lf->u.sec2.op = H5F_OP_UNKNOWN;
+	HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "write failed");
     }
+
     /*
      * Update the file position.
      */
     lf->u.sec2.op = H5F_OP_WRITE;
-    lf->u.sec2.cur = offset + size; /*FIX_ME*/
-    assert("address overflowed" && lf->u.sec2.cur >= offset);
+    lf->u.sec2.cur = offset + n;
 
     FUNC_LEAVE(SUCCEED);
 }
diff --git a/src/H5Fstdio.c b/src/H5Fstdio.c
index a7cb096..ed0cdb2 100644
--- a/src/H5Fstdio.c
+++ b/src/H5Fstdio.c
@@ -1,9 +1,9 @@
 /*
  * Copyright (C) 1997 NCSA
- *                    All rights reserved.
+ *		      All rights reserved.
  *
  * Programmer: Robb Matzke <matzke@llnl.gov>
- *             Wednesday, October 22, 1997
+ *	       Wednesday, October 22, 1997
  *
  * Purpose:    This is the Posix stdio.h I/O subclass of H5Flow.
  */
@@ -16,89 +16,92 @@
 #include <sys/types.h>
 #include <sys/stat.h>
 
-#define PABLO_MASK      H5F_stdio
-static hbool_t          interface_initialize_g = FALSE;
-#define INTERFACE_INIT  NULL
+#define PABLO_MASK	H5F_stdio
+static hbool_t		interface_initialize_g = FALSE;
+#define INTERFACE_INIT	NULL
 
-static H5F_low_t       *H5F_stdio_open(const char *name, uintn flags,
-                                       H5F_search_t *key);
-static herr_t           H5F_stdio_close(H5F_low_t *lf);
-static herr_t           H5F_stdio_read(H5F_low_t *lf, const haddr_t *addr, size_t size,
-                                       uint8 *buf);
-static herr_t           H5F_stdio_write(H5F_low_t *lf, const haddr_t *addr, size_t size,
-                                        const uint8 *buf);
-static herr_t           H5F_stdio_flush(H5F_low_t *lf);
+static H5F_low_t *H5F_stdio_open(const char *name,
+				 const H5F_access_t *access_parms, uintn flags,
+				 H5F_search_t *key/*out*/);
+static herr_t H5F_stdio_close(H5F_low_t *lf, const H5F_access_t *access_parms);
+static herr_t H5F_stdio_read(H5F_low_t *lf, const H5F_access_t *access_parms,
+			     const haddr_t *addr, size_t size,
+			     uint8 *buf/*out*/);
+static herr_t H5F_stdio_write(H5F_low_t *lf, const H5F_access_t *access_parms,
+			      const haddr_t *addr, size_t size,
+			      const uint8 *buf);
+static herr_t H5F_stdio_flush(H5F_low_t *lf, const H5F_access_t *access_parms);
+
+const H5F_low_class_t H5F_LOW_STDIO_g[1] = {{
+    NULL,			/* use default access(2) func		*/
+    H5F_stdio_open,		/* open method				*/
+    H5F_stdio_close,		/* close method				*/
+    H5F_stdio_read,		/* read method				*/
+    H5F_stdio_write,		/* write method				*/
+    H5F_stdio_flush,		/* flush method				*/
+    NULL,			/* extend method			*/
+}};
 
-const H5F_low_class_t   H5F_LOW_STDIO[1] =
-{
-    {
-        NULL,                   /* use default access(2) func           */
-        H5F_stdio_open,         /* open method                          */
-        H5F_stdio_close,        /* close method                         */
-        H5F_stdio_read,         /* read method                          */
-        H5F_stdio_write,        /* write method                         */
-        H5F_stdio_flush,        /* flush method                         */
-        NULL,                   /* extend method                        */
-    }};
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_stdio_open
+ * Function:	H5F_stdio_open
  *
- * Purpose:     Opens a file with name NAME.  The FLAGS are a bit field with
- *              the possible values defined in H5F_low_open().
+ * Purpose:	Opens a file with name NAME.  The FLAGS are a bit field with
+ *		the possible values defined in H5F_low_open().
  *
- * Bugs:        H5F_ACC_EXCL has a race condition.
+ * Bugs:	H5F_ACC_EXCL has a race condition.
  *
  * Errors:
- *              IO        CANTOPENFILE  File doesn't exist and CREAT wasn't
- *                                      specified. 
- *              IO        CANTOPENFILE  Fopen failed. 
- *              IO        FILEEXISTS    File exists but CREAT and EXCL were
- *                                      specified. 
+ *		IO	  CANTOPENFILE	File doesn't exist and CREAT wasn't
+ *					specified. 
+ *		IO	  CANTOPENFILE	Fopen failed. 
+ *		IO	  FILEEXISTS	File exists but CREAT and EXCL were
+ *					specified. 
  *
- * Return:      Success:        Low-level file pointer
+ * Return:	Success:	Low-level file pointer
  *
- *              Failure:        NULL
+ *		Failure:	NULL
  *
- * Programmer:  Robb Matzke
- *              Wednesday, October 22, 1997
+ * Programmer:	Robb Matzke
+ *		Wednesday, October 22, 1997
  *
  * Modifications:
  *
  *-------------------------------------------------------------------------
  */
-static H5F_low_t       *
-H5F_stdio_open(const char *name, uintn flags, H5F_search_t *key /*out */ )
+static H5F_low_t *
+H5F_stdio_open(const char *name, const H5F_access_t *access_parms,
+	       uintn flags, H5F_search_t *key/*out*/)
 {
-    H5F_low_t              *lf = NULL;
-    FILE                   *f = NULL;
-    struct stat             sb;
+    H5F_low_t		   *lf = NULL;
+    FILE		   *f = NULL;
+    struct stat		    sb;
 
     FUNC_ENTER(H5F_stdio_open, NULL);
 
     if (access(name, F_OK) < 0) {
-        if ((flags & H5F_ACC_CREAT) && (flags & H5F_ACC_WRITE)) {
-            f = fopen(name, "wb+");
-        } else {
-            HRETURN_ERROR(H5E_IO, H5E_CANTOPENFILE, NULL,
-                          "file doesn't exist and CREAT wasn't specified");
-        }
+	if ((flags & H5F_ACC_CREAT) && (flags & H5F_ACC_RDWR)) {
+	    f = fopen(name, "wb+");
+	} else {
+	    HRETURN_ERROR(H5E_IO, H5E_CANTOPENFILE, NULL,
+			  "file doesn't exist and CREAT wasn't specified");
+	}
 
     } else if ((flags & H5F_ACC_CREAT) && (flags & H5F_ACC_EXCL)) {
-        HRETURN_ERROR(H5E_IO, H5E_FILEEXISTS, NULL,
-                      "file exists but CREAT and EXCL were specified");
+	HRETURN_ERROR(H5E_IO, H5E_FILEEXISTS, NULL,
+		      "file exists but CREAT and EXCL were specified");
 
-    } else if (flags & H5F_ACC_WRITE) {
-        if (flags & H5F_ACC_TRUNC)
-            f = fopen(name, "wb+");
-        else
-            f = fopen(name, "rb+");
+    } else if (flags & H5F_ACC_RDWR) {
+	if (flags & H5F_ACC_TRUNC)
+	    f = fopen(name, "wb+");
+	else
+	    f = fopen(name, "rb+");
 
     } else {
-        f = fopen(name, "rb");
+	f = fopen(name, "rb");
     }
     if (!f)
-        HRETURN_ERROR(H5E_IO, H5E_CANTOPENFILE, NULL, "fopen failed");
+	HRETURN_ERROR(H5E_IO, H5E_CANTOPENFILE, NULL, "fopen failed");
 
     /* Build the return value */
     lf = H5MM_xcalloc(1, sizeof(H5F_low_t));
@@ -107,46 +110,46 @@ H5F_stdio_open(const char *name, uintn flags, H5F_search_t *key /*out */ )
     lf->u.stdio.cur = 0;
     H5F_addr_reset(&(lf->eof));
     if (fseek(lf->u.stdio.f, 0, SEEK_END) < 0) {
-        lf->u.stdio.op = H5F_OP_UNKNOWN;
+	lf->u.stdio.op = H5F_OP_UNKNOWN;
     } else {
-        H5F_addr_inc(&(lf->eof), ftell(lf->u.stdio.f));
+	H5F_addr_inc(&(lf->eof), ftell(lf->u.stdio.f));
     }
 
     /* The unique key */
     if (key) {
-        fstat(fileno(f), &sb);
-        key->dev = sb.st_dev;
-        key->ino = sb.st_ino;
+	fstat(fileno(f), &sb);
+	key->dev = sb.st_dev;
+	key->ino = sb.st_ino;
     }
     FUNC_LEAVE(lf);
 }
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_stdio_close
+ * Function:	H5F_stdio_close
  *
- * Purpose:     Closes a file.
+ * Purpose:	Closes a file.
  *
  * Errors:
- *              IO        CLOSEERROR    Fclose failed. 
+ *		IO	  CLOSEERROR	Fclose failed. 
  *
- * Return:      Success:        SUCCEED
+ * Return:	Success:	SUCCEED
  *
- *              Failure:        FAIL
+ *		Failure:	FAIL
  *
- * Programmer:  Robb Matzke
- *              Wednesday, October 22, 1997
+ * Programmer:	Robb Matzke
+ *		Wednesday, October 22, 1997
  *
  * Modifications:
  *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F_stdio_close(H5F_low_t *lf)
+H5F_stdio_close(H5F_low_t *lf, const H5F_access_t *access_parms)
 {
     FUNC_ENTER(H5F_stdio_close, FAIL);
 
     if (fclose(lf->u.stdio.f) < 0) {
-        HRETURN_ERROR(H5E_IO, H5E_CLOSEERROR, FAIL, "fclose failed");
+	HRETURN_ERROR(H5E_IO, H5E_CLOSEERROR, FAIL, "fclose failed");
     }
     lf->u.stdio.f = NULL;
 
@@ -154,66 +157,82 @@ H5F_stdio_close(H5F_low_t *lf)
 }
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_stdio_read
+ * Function:	H5F_stdio_read
  *
- * Purpose:     Reads SIZE bytes beginning at address ADDR in file LF and
- *              places them in buffer BUF.  Reading past the logical or
- *              physical end of file returns zeros instead of failing.
+ * Purpose:	Reads SIZE bytes beginning at address ADDR in file LF and
+ *		places them in buffer BUF.  Reading past the logical or
+ *		physical end of file returns zeros instead of failing.
  *
  * Errors:
- *              IO        READERROR     Fread failed. 
- *              IO        SEEKERROR     Fseek failed. 
+ *		IO	  READERROR	Fread failed. 
+ *		IO	  SEEKERROR	Fseek failed. 
  *
- * Return:      Success:        SUCCEED
+ * Return:	Success:	SUCCEED
  *
- *              Failure:        FAIL
+ *		Failure:	FAIL
  *
- * Programmer:  Robb Matzke
- *              Wednesday, October 22, 1997
+ * Programmer:	Robb Matzke
+ *		Wednesday, October 22, 1997
  *
  * Modifications:
  *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F_stdio_read(H5F_low_t *lf, const haddr_t *addr, size_t size, uint8 *buf)
+H5F_stdio_read(H5F_low_t *lf, const H5F_access_t *access_parms,
+	       const haddr_t *addr, size_t size, uint8 *buf/*out*/)
 {
-    size_t                  n;
-    off_t                   offset;
+    size_t		n;
+    uint64		mask;
+#ifdef HAVE_FSEEK64
+    long long		offset;
+#else
+    off_t		offset;
+#endif
 
     FUNC_ENTER(H5F_stdio_read, FAIL);
 
     /* Check for overflow */
-    offset = addr->offset; /*FIX_ME*/
-    assert("address overflowed" && offset == addr->offset);
-    assert("overflow" && offset + size >= offset);
+    mask = (uint64)1 << (8*sizeof(offset)-1);
+    if (addr->offset >= mask ||
+	addr->offset + size < addr->offset ||
+	addr->offset+size >= mask) {
+	HRETURN_ERROR (H5E_IO, H5E_OVERFLOW, FAIL, "file address overflowed");
+    }
+#ifdef HAVE_FSEEK64
+    offset = (long long)(addr->offset); /*checked for overflow*/
+#else
+    offset = (off_t)(addr->offset); /*checked for overflow*/
+#endif
 
     /* Check easy cases */
-    if (0 == size)
-        HRETURN(SUCCEED);
+    if (0 == size) HRETURN(SUCCEED);
     if (offset >= lf->eof.offset) {
-        HDmemset(buf, 0, size);
-        HRETURN(SUCCEED);
+	HDmemset(buf, 0, size);
+	HRETURN(SUCCEED);
     }
+
     /*
      * Seek to the correct file position.
      */
     if (!H5F_OPT_SEEK ||
-        lf->u.stdio.op != H5F_OP_READ ||
-        lf->u.stdio.cur != offset) {
-        if (fseek(lf->u.stdio.f, offset, SEEK_SET) < 0) {
-            HRETURN_ERROR(H5E_IO, H5E_SEEKERROR, FAIL, "fseek failed");
-        }
-        lf->u.stdio.cur = offset;
+	lf->u.stdio.op != H5F_OP_READ ||
+	lf->u.stdio.cur != offset) {
+	if (fseek(lf->u.stdio.f, offset, SEEK_SET) < 0) {
+	    HRETURN_ERROR(H5E_IO, H5E_SEEKERROR, FAIL, "fseek failed");
+	}
+	lf->u.stdio.cur = offset;
     }
+
     /*
      * Read zeros past the logical end of file (physical is handled below)
      */
     if ((size_t) offset + size > lf->eof.offset) {
-        size_t                  nbytes = (size_t) offset + size - lf->eof.offset;
-        HDmemset(buf + size - nbytes, 0, nbytes);
-        size -= nbytes;
+	size_t nbytes = (size_t) offset + size - lf->eof.offset;
+	HDmemset(buf + size - nbytes, 0, nbytes);
+	size -= nbytes;
     }
+    
     /*
      * Read the data.  Since we're reading single-byte values, a partial read
      * will advance the file position by N.  If N is negative or an error
@@ -221,102 +240,122 @@ H5F_stdio_read(H5F_low_t *lf, const haddr_t *addr, size_t size, uint8 *buf)
      */
     n = fread(buf, 1, size, lf->u.stdio.f);
     if (n <= 0 && ferror(lf->u.stdio.f)) {
-        lf->u.stdio.op = H5F_OP_UNKNOWN;
-        HRETURN_ERROR(H5E_IO, H5E_READERROR, FAIL, "fread failed");
+	lf->u.stdio.op = H5F_OP_UNKNOWN;
+	HRETURN_ERROR(H5E_IO, H5E_READERROR, FAIL, "fread failed");
     } else if (n < size) {
-        HDmemset(buf + n, 0, size - n);
+	HDmemset(buf + n, 0, size - n);
     }
+    
     /*
      * Update the file position data.
      */
     lf->u.stdio.op = H5F_OP_READ;
-    lf->u.stdio.cur = offset + n; /*FIX_ME*/
+    lf->u.stdio.cur = offset + n;
     FUNC_LEAVE(SUCCEED);
 }
+
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_stdio_write
+ * Function:	H5F_stdio_write
  *
- * Purpose:     Writes SIZE bytes from the beginning of BUF into file LF at
- *              file address ADDR.
+ * Purpose:	Writes SIZE bytes from the beginning of BUF into file LF at
+ *		file address ADDR.
  *
  * Errors:
- *              IO        SEEKERROR     Fseek failed. 
- *              IO        WRITEERROR    Fwrite failed. 
+ *		IO	  SEEKERROR	Fseek failed. 
+ *		IO	  WRITEERROR	Fwrite failed. 
  *
- * Return:      Success:        SUCCEED
+ * Return:	Success:	SUCCEED
  *
- *              Failure:        FAIL
+ *		Failure:	FAIL
  *
- * Programmer:  Robb Matzke
- *              Wednesday, October 22, 1997
+ * Programmer:	Robb Matzke
+ *		Wednesday, October 22, 1997
  *
  * Modifications:
  *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F_stdio_write(H5F_low_t *lf, const haddr_t *addr, size_t size,
-                const uint8 *buf)
+H5F_stdio_write(H5F_low_t *lf, const H5F_access_t *access_parms,
+		const haddr_t *addr, size_t size,
+		const uint8 *buf)
 {
-    off_t                   offset;
+    ssize_t		n;
+    uint64		mask;
+#ifdef HAVE_FSEEK64
+    long long		offset;
+#else
+    off_t		offset;
+#endif
 
     FUNC_ENTER(H5F_stdio_write, FAIL);
 
     /* Check for overflow */
-    offset = addr->offset; /*FIX_ME*/
-    assert("address overflowed" && offset == addr->offset);
-    assert("overflow" && offset + size >= offset);
+    mask = (uint64)1 << (8*sizeof(offset)-1);
+    if (addr->offset >= mask ||
+	addr->offset+size < addr->offset ||
+	addr->offset+size >= mask) {
+	HRETURN_ERROR (H5E_IO, H5E_OVERFLOW, FAIL, "file address overflowed");
+    }
+#ifdef HAVE_FSEEK64
+    offset = (long long)(addr->offset); /*checked for overflow*/
+    n = (long long)size; /*checked for overflow*/
+#else
+    offset = (long)(addr->offset); /*checked for overflow*/
+    n = (off_t)size; /*checked for overflow*/
+#endif
 
     /*
      * Seek to the correct file position.
      */
     if (!H5F_OPT_SEEK ||
-        lf->u.stdio.op != H5F_OP_WRITE ||
-        lf->u.stdio.cur != offset) {
-        if (fseek(lf->u.stdio.f, offset, SEEK_SET) < 0) {
-            HRETURN_ERROR(H5E_IO, H5E_SEEKERROR, FAIL, "fseek failed");
-        }
-        lf->u.stdio.cur = offset;
+	lf->u.stdio.op != H5F_OP_WRITE ||
+	lf->u.stdio.cur != offset) {
+	if (fseek(lf->u.stdio.f, offset, SEEK_SET) < 0) {
+	    HRETURN_ERROR(H5E_IO, H5E_SEEKERROR, FAIL, "fseek failed");
+	}
+	lf->u.stdio.cur = offset;
     }
     /*
      * Write the buffer.  On successful return, the file position will be
      * advanced by the number of bytes read.  Otherwise nobody knows where it
      * is.
      */
-    if (size != fwrite(buf, 1, size, lf->u.stdio.f)) {
-        lf->u.stdio.op = H5F_OP_UNKNOWN;
-        HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "fwrite failed");
+    if (n != fwrite(buf, 1, size, lf->u.stdio.f)) {
+	lf->u.stdio.op = H5F_OP_UNKNOWN;
+	HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "fwrite failed");
     }
     /*
      * Update seek optimizing data.
      */
     lf->u.stdio.op = H5F_OP_WRITE;
-    lf->u.stdio.cur = offset + size; /*FIX_ME*/
+    lf->u.stdio.cur = offset + n;
     FUNC_LEAVE(SUCCEED);
 }
+
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_stdio_flush
+ * Function:	H5F_stdio_flush
  *
- * Purpose:     Makes sure that all data is on disk.
+ * Purpose:	Makes sure that all data is on disk.
  *
  * Errors:
- *              IO        WRITEERROR    Fflush failed. 
+ *		IO	  WRITEERROR	Fflush failed. 
  *
- * Return:      Success:        SUCCEED
+ * Return:	Success:	SUCCEED
  *
- *              Failure:        FAIL
+ *		Failure:	FAIL
  *
- * Programmer:  Robb Matzke
- *              Wednesday, October 22, 1997
+ * Programmer:	Robb Matzke
+ *		Wednesday, October 22, 1997
  *
  * Modifications:
  *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F_stdio_flush(H5F_low_t *lf)
+H5F_stdio_flush(H5F_low_t *lf, const H5F_access_t *access_parms)
 {
     FUNC_ENTER(H5F_stdio_flush, FAIL);
 
@@ -330,7 +369,7 @@ H5F_stdio_flush(H5F_low_t *lf)
      * Flush
      */
     if (fflush(lf->u.stdio.f) < 0) {
-        HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "fflush failed");
+	HRETURN_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "fflush failed");
     }
     FUNC_LEAVE(SUCCEED);
 }
diff --git a/src/H5MF.c b/src/H5MF.c
index 6e0c257..8985490 100644
--- a/src/H5MF.c
+++ b/src/H5MF.c
@@ -68,7 +68,8 @@ H5MF_alloc(H5F_t *f, intn op, size_t size, haddr_t *addr /*out */ )
      * from there.  But for now we just allocate more memory from the end of
      * the file.
      */
-    if (H5F_low_extend(f->shared->lf, op, size, addr /*out */ ) < 0) {
+    if (H5F_low_extend(f->shared->lf, &(f->shared->access_parms), op,
+		       size, addr/*out*/) < 0) {
         HRETURN_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL,
                       "low level mem management failed");
     }
diff --git a/src/H5config.h.in b/src/H5config.h.in
index be212ba..6efe276 100644
--- a/src/H5config.h.in
+++ b/src/H5config.h.in
@@ -49,6 +49,12 @@
 /* The number of bytes in a short.  */
 #undef SIZEOF_SHORT
 
+/* Define if you have the fseek64 function.  */
+#undef HAVE_FSEEK64
+
+/* Define if you have the lseek64 function.  */
+#undef HAVE_LSEEK64
+
 /* Define if you have the mpi library (-lmpi).  */
 #undef HAVE_LIBMPI
 
diff --git a/src/H5private.h b/src/H5private.h
index 128f875..88187fd 100644
--- a/src/H5private.h
+++ b/src/H5private.h
@@ -46,15 +46,6 @@
 #  include <unistd.h>
 #endif
 
-#ifdef HAVE_PARALLEL
-/*
- * MPIO headers
- */
-#  include <mpi.h>
-#  include <mpio.h>
-#endif
-
-
 /*
  * Pablo support files.
  */
diff --git a/src/H5public.h b/src/H5public.h
index 9d7eee8..ed7933f 100644
--- a/src/H5public.h
+++ b/src/H5public.h
@@ -19,8 +19,8 @@
 #include <H5config.h>           /*from configure                             */
 #include <sys/types.h>
 #ifdef HAVE_PARALLEL
-#include <mpi.h>
-#include <mpio.h>
+#  include <mpi.h>
+#  include <mpio.h>
 #endif
 
 /*