[svn-r5894] Purpose:

    Bug fix/Code cleanup/New Feature

Description:
    Correct problems with writing fill-values to external storage and allocate
    the data storage at the correct times.

    Also, mostly straighten out the strange code which allocates and fills
    raw data storage for datasets.  Things are still a bit odd in that the
    fill-values for chunked datasets are written when the space is allocated,
    instead of in a separate routine, but there are two reasons for this:
    it's inefficient (especially in parallel) to iterate through all the chunks
    twice, and (more importantly) the space needed to store compressed chunks
    isn't known until we've got a buffer of compressed fill-values ready to
    write to the chunk.

    Additionally, add in the H5D_SPACE_ALLOC_INCR and H5D_SPACE_ALLOC_DEFAULT
    setting for the "space time", which incorporate the previous behavior of
    the space allocation for chunked datasets.

    The default settings for the different types of dataset storage are now
    as follows:
        Contiguous - Late
        Chunked    - Incremental
        Compact    - Early

    This checkin also incorporates a change to the behavior of external data
    storage in two ways - fill-values are _never_ written to external storage
    (under the assumption that writing fill-values is triggered by allocating
    space in an HDF5 file, and since space is not allocated in the file, the
    fill-values should not be written) and external data files are now created
    if they don't exist when data is written to them.  The fill-value will
    probably need to be revisited at some time in the future, this just seemed
    like the safer course currently.

    I think I cleaned up some compiler errors also, before getting bogged down
    in the fixes for the space allocation and fill-values.

Platforms tested:
    FreeBSD 4.6 (sleipnir) w/serial & parallel.  Will be testing on IRIX64
    6.5 (modi4) in serial & parallel shortly.

20 files changed, 857 insertions, 410 deletions

diff --git a/src/H5D.c b/src/H5D.c
index 645e81b..577e25f 100644
--- a/src/H5D.c
+++ b/src/H5D.c
@@ -22,6 +22,7 @@
 #include "H5Gprivate.h"		/* Group headers		  	*/
 #include "H5HLprivate.h"	/* Name heap				*/
 #include "H5Iprivate.h"		/* IDs			  		*/
+#include "H5MFprivate.h"	/* File space management		*/
 #include "H5MMprivate.h"	/* Memory management			*/
 #include "H5Oprivate.h"		/* Object headers		  	*/
 #include "H5Pprivate.h"		/* Property lists			*/
@@ -44,8 +45,11 @@
 #   include "H5Rpublic.h"
 #endif /*H5_HAVE_PARALLEL*/
 
+/* Pablo information */
 #define PABLO_MASK	H5D_mask
 
+/* Local typedefs */
+
 /*
  * A dataset is the following struct.
  */
@@ -56,11 +60,22 @@ struct H5D_t {
     H5O_layout_t	layout;		/* data layout			*/
 };
 
+/* Enumerated type for allocating dataset's storage */
+typedef enum {
+    H5D_ALLOC_CREATE,           /* Dataset is being created */
+    H5D_ALLOC_OPEN,             /* Dataset is being opened */
+    H5D_ALLOC_EXTEND,           /* Dataset's dataspace is being extended */
+    H5D_ALLOC_WRITE             /* Dataset is being extended */
+} H5D_alloc_time_t;
 
+/* Interface initialization */
 static int interface_initialize_g = 0;
 #define INTERFACE_INIT H5D_init_interface
+
+/* Local functions */
 static herr_t H5D_init_interface(void);
-static herr_t H5D_init_storage(H5D_t *dataset, const H5S_t *space);
+static herr_t H5D_alloc_storage (H5F_t *f, H5D_t *dset,H5D_alloc_time_t alloc_time);
+static herr_t H5D_init_storage(H5D_t *dataset);
 H5D_t * H5D_new(hid_t dcpl_id);
 static herr_t H5D_fill(const void *fill, const H5T_t *fill_type, void *buf,
     const H5T_t *buf_type, const H5S_t *space);
@@ -70,7 +85,7 @@ static herr_t H5D_get_space_status(H5D_t *dset, H5D_space_status_t *allocation);
 H5FL_DEFINE_STATIC(H5D_t);
 
 /* Declare a free list to manage blocks of type conversion data */
-H5FL_BLK_DEFINE_STATIC(type_conv);
+H5FL_BLK_DEFINE(type_conv);
 
 /* Declare a free list to manage blocks of single datatype element data */
 H5FL_BLK_DEFINE(type_elem);
@@ -1533,22 +1548,46 @@ H5D_create(H5G_entry_t *loc, const char *name, const H5T_t *type,
         HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't retrieve pipeline filter");
     if(H5P_get(plist, H5D_CRT_LAYOUT_NAME, &dcpl_layout) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't retrieve layout");
-    if(H5P_get(plist, H5D_CRT_SPACE_TIME_NAME, &space_time) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't retrieve space allocation time");
     if(dcpl_pline.nfilters > 0 && H5D_CHUNKED != dcpl_layout)
         HGOTO_ERROR(H5E_DATASET, H5E_BADVALUE, NULL, "filters can only be used with chunked layout");
-    if(dcpl_layout==H5D_COMPACT && space_time==H5D_SPACE_ALLOC_LATE)
+    if(H5P_get(plist, H5D_CRT_SPACE_TIME_NAME, &space_time) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't retrieve space allocation time");
+
+    /* Check if the space_time is the default and set it accordingly */
+    if(space_time==H5D_SPACE_ALLOC_DEFAULT) {
+        switch(dcpl_layout) {
+            case H5D_COMPACT:
+                space_time=H5D_SPACE_ALLOC_EARLY;
+                break;
+
+            case H5D_CONTIGUOUS:
+                space_time=H5D_SPACE_ALLOC_LATE;
+                break;
+
+            case H5D_CHUNKED:
+                space_time=H5D_SPACE_ALLOC_INCR;
+                break;
+
+            default:
+                HGOTO_ERROR(H5E_DATASET, H5E_UNSUPPORTED, NULL, "not implemented yet");
+        } /* end switch */
+    } /* end if */
+
+    /* Don't allow compact datasets to allocate space later */
+    if(dcpl_layout==H5D_COMPACT && space_time!=H5D_SPACE_ALLOC_EARLY)
         HGOTO_ERROR(H5E_DATASET, H5E_BADVALUE, NULL, "compact dataset doesn't support late space allocation");
 
     /* What file is the dataset being added to? */
     if (NULL==(f=H5G_insertion_file(loc, name)))
         HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL, "unable to locate insertion point");
 
-#ifdef H5_HAVE_PARALLEL
     /* If MPIO or MPIPOSIX is used, no filter support yet. */
     if((IS_H5FD_MPIO(f) || IS_H5FD_MPIPOSIX(f)) && dcpl_pline.nfilters > 0) 
         HGOTO_ERROR(H5E_DATASET, H5E_UNSUPPORTED, NULL, "Parallel I/O does not support filters yet");
-#endif /*H5_HAVE_PARALLEL*/
+
+    /* Check if this dataset is going into a parallel file and set space allocation time */
+    if(IS_H5FD_MPIO(f) || IS_H5FD_MPIPOSIX(f))
+        space_time=H5D_SPACE_ALLOC_EARLY;
    
     if(H5P_get(plist, H5D_CRT_FILL_TIME_NAME, &fill_time) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't retrieve fill time");
@@ -1576,6 +1615,10 @@ H5D_create(H5G_entry_t *loc, const char *name, const H5T_t *type,
     if (NULL == (new_plist = H5I_object(new_dset->dcpl_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "can't get dataset creation property list");
 
+    /* Set the space_time for the dataset, in case the default was used */
+    if(H5P_set(new_plist, H5D_CRT_SPACE_TIME_NAME, &space_time) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, NULL, "can't set allocation time");  
+
     if(H5P_get(new_plist, H5D_CRT_CHUNK_DIM_NAME, &chunk_ndims) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't retrieve layout");
     
@@ -1588,6 +1631,7 @@ H5D_create(H5G_entry_t *loc, const char *name, const H5T_t *type,
     new_dset->layout.ndims = H5S_get_simple_extent_ndims(space) + 1;
     assert((unsigned)(new_dset->layout.ndims) <= NELMTS(new_dset->layout.dim));
     new_dset->layout.dim[new_dset->layout.ndims-1] = H5T_get_size(new_dset->type);    
+    new_dset->layout.addr = HADDR_UNDEF;        /* Initialize to no address */
 
     switch (new_dset->layout.type) {
         case H5D_CONTIGUOUS:
@@ -1741,34 +1785,11 @@ H5D_create(H5G_entry_t *loc, const char *name, const H5T_t *type,
         HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL, "unable to name dataset");
 
     /*
-     * Allocate storage.  We assume that external storage is already
-     * allocated by the caller, or at least will be before I/O is performed.
-     * For parallelization, space is always allocated now except using 
-     * external storage. For contiguous layout, space is allocated now if 
-     * space allocate time is early; otherwise delay allocation until H5Dwrite.
-     * For compact dataset, space is allocated regardless of space allocation
-     * time.
+     * Allocate storage if space allocate time is early; otherwise delay allocation until later.
      */
-#ifdef H5_HAVE_PARALLEL
-    if (0==efl.nused) {
-        if(H5F_arr_create(f, &(new_dset->layout))<0)
-            HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL, "unable to initialize storage");
-    } /* end if */
-    else
-	new_dset->layout.addr = HADDR_UNDEF;
-#else /*H5_HAVE_PARALLEL*/
-    if (0==efl.nused) {
-        if(dcpl_layout==H5D_CHUNKED || dcpl_layout==H5D_COMPACT || 
-            (dcpl_layout==H5D_CONTIGUOUS && space_time==H5D_SPACE_ALLOC_EARLY)) {
-            if (H5F_arr_create(f, &(new_dset->layout))<0)
-            	HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL, "unable to initialize storage"); 
-        } /* end if */
-        else
-	    new_dset->layout.addr = HADDR_UNDEF;
-    } /* end if */
-    else
-        new_dset->layout.addr = HADDR_UNDEF;
-#endif /*H5_HAVE_PARALLEL*/
+    if(space_time==H5D_SPACE_ALLOC_EARLY)
+        if (H5D_alloc_storage(f, new_dset,H5D_ALLOC_CREATE)<0)
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL, "unable to initialize storage"); 
 
     /* Update external storage message */
     if (efl.nused>0) {
@@ -1791,34 +1812,9 @@ H5D_create(H5G_entry_t *loc, const char *name, const H5T_t *type,
             HGOTO_ERROR (H5E_DATASET, H5E_CANTINIT, NULL, "unable to update external file list message");
     } /* end if */
 
-    /* Initialize the raw data when it's 
-     *  1. Parallel I/O
-     *  2. layout is contiguous, space allocation time is early, fill value 
-     *     writing time is upon allocation 
-     *  3. external space is treated the same as internal except it's always
-     *     assumed as early for space allocation time
-     *  4. compact dataset and fill value writing time is upon allocation
-     */
-#ifdef H5_HAVE_PARALLEL
-    if (H5D_init_storage(new_dset, space)<0)
-	HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL, "unable to initialize storage");
-#else /*H5_HAVE_PARALLEL*/
-    if(fill_time==H5D_FILL_TIME_ALLOC) {
-        if((dcpl_layout==H5D_CONTIGUOUS && space_time==H5D_SPACE_ALLOC_EARLY)
-            || (dcpl_layout==H5D_CHUNKED && space_time==H5D_SPACE_ALLOC_EARLY) 
-            || dcpl_layout==H5D_COMPACT ) {
-	    if (H5D_init_storage(new_dset, space)<0) {
-	        HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL, "unable to initialize storage");
-            }
-        }
-     }
-#endif /*H5_HAVE_PARALLEL*/
-
     /* Update layout message */
     if (H5D_COMPACT != new_dset->layout.type && H5O_modify (&(new_dset->ent), H5O_LAYOUT, 0, 0, &(new_dset->layout))<0)
          HGOTO_ERROR (H5E_DATASET, H5E_CANTINIT, NULL, "unable to update layout"); 
-    if (H5D_COMPACT == new_dset->layout.type)
-         new_dset->layout.dirty = TRUE;
     
     /* Success */
     ret_value = new_dset;
@@ -1969,7 +1965,6 @@ H5D_open_oid(H5G_entry_t *ent)
 {
     H5D_t 	*dataset = NULL;	/*new dataset struct 		*/
     H5D_t 	*ret_value = NULL;	/*return value			*/
-    H5S_t	*space = NULL;		/*data space			*/
     H5O_fill_new_t  fill = {NULL, 0, NULL, H5D_SPACE_ALLOC_LATE, H5D_FILL_TIME_ALLOC, TRUE}; 
     H5O_fill_t      fill_prop = {NULL, 0, NULL};
     H5O_pline_t pline;                  /* I/O pipeline information */
@@ -1997,47 +1992,11 @@ H5D_open_oid(H5G_entry_t *ent)
     /* Get the type and space */
     if (NULL==(dataset->type=H5O_read(&(dataset->ent), H5O_DTYPE, 0, NULL)))
         HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL, "unable to load type info from dataset header");
-    if (NULL==(space=H5S_read (&(dataset->ent))))
-        HGOTO_ERROR (H5E_DATASET, H5E_CANTINIT, NULL, "unable to read data space info from dataset header");
 
     /* Get dataset creation property list object */
     if (NULL == (plist = H5I_object(dataset->dcpl_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "can't get dataset creation property list");
 
-    /* Retrieve & release the previous fill-value settings */
-    if(H5P_get(plist, H5D_CRT_FILL_VALUE_NAME, &fill_prop) < 0)
-        HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, NULL, "can't get fill value");
-    H5O_reset(H5O_FILL, &fill_prop);
-
-    /* Get the new fill value message */
-    if(NULL == H5O_read(&(dataset->ent), H5O_FILL_NEW, 0, &fill)) {
-        H5E_clear();
-        HDmemset(&fill, 0, sizeof(fill));
-    }
-    if(fill.fill_defined) {
-        if(NULL==H5O_copy(H5O_FILL, &fill, &fill_prop))
-            HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL, "can't copy fill value");
-    } else {
-	/* For compatibility with v1.4.  Retrieve the old fill value message.
- 	 * If size is 0, make it -1 for undefined. */
-        if(NULL == H5O_read(&(dataset->ent), H5O_FILL, 0, &fill_prop)) {
-            H5E_clear();
-            HDmemset(&fill_prop, 0, sizeof(fill_prop));
-        }
-        if(fill_prop.size == 0) {
-	    fill_prop.type = fill_prop.buf = NULL;
-	    fill_prop.size = (size_t)-1;
-	}
-    } /* end else */
-	
-    /* Set fill value properties */ 
-    if(H5P_set(plist, H5D_CRT_FILL_VALUE_NAME, &fill_prop) < 0)
-        HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, NULL, "can't set fill value");
-    if(H5P_set(plist, H5D_CRT_SPACE_TIME_NAME, &fill.space_time) < 0)
-        HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, NULL, "can't set fill value");
-    if(H5P_set(plist, H5D_CRT_FILL_TIME_NAME, &fill.fill_time) < 0)
-        HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, NULL, "can't set fill value");
-
     /* Get the optional filters message */
     HDmemset(&pline,0,sizeof(H5O_pline_t));
     if(NULL == H5O_read(&(dataset->ent), H5O_PLINE, 0, &pline)) {
@@ -2047,11 +2006,9 @@ H5D_open_oid(H5G_entry_t *ent)
     if(H5P_set(plist, H5D_CRT_DATA_PIPELINE_NAME, &pline) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, NULL, "can't set pipeline");
 
-#ifdef H5_HAVE_PARALLEL
     /* If MPIO or MPIPOSIX is used, no filter support yet. */
     if((IS_H5FD_MPIO(dataset->ent.file) || IS_H5FD_MPIPOSIX(dataset->ent.file)) && pline.nfilters > 0)
         HGOTO_ERROR (H5E_DATASET, H5E_UNSUPPORTED, NULL, "Parallel IO does not support filters yet");
-#endif /*H5_HAVE_PARALLEL*/
     
     /*
      * Get the raw data layout info.  It's actually stored in two locations:
@@ -2094,6 +2051,58 @@ H5D_open_oid(H5G_entry_t *ent)
             HGOTO_ERROR(H5E_DATASET, H5E_UNSUPPORTED, NULL, "not implemented yet");
     } /* end switch */
 
+    /* Retrieve & release the previous fill-value settings */
+    if(H5P_get(plist, H5D_CRT_FILL_VALUE_NAME, &fill_prop) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, NULL, "can't get fill value");
+    H5O_reset(H5O_FILL, &fill_prop);
+
+    /* Get the new fill value message */
+    if(NULL == H5O_read(&(dataset->ent), H5O_FILL_NEW, 0, &fill)) {
+        H5E_clear();
+        HDmemset(&fill, 0, sizeof(fill));
+
+        /* Set the space allocation time appropriately, based on the type of dataset storage */
+        switch (dataset->layout.type) {
+            case H5D_COMPACT:
+                fill.space_time=H5D_SPACE_ALLOC_EARLY;
+                break;
+
+            case H5D_CONTIGUOUS:
+                fill.space_time=H5D_SPACE_ALLOC_LATE;
+                break;
+
+            case H5D_CHUNKED:
+                fill.space_time=H5D_SPACE_ALLOC_INCR;
+                break;
+                
+            default:
+                HGOTO_ERROR(H5E_DATASET, H5E_UNSUPPORTED, NULL, "not implemented yet");
+        } /* end switch */
+    } /* end if */
+    if(fill.fill_defined) {
+        if(NULL==H5O_copy(H5O_FILL, &fill, &fill_prop))
+            HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL, "can't copy fill value");
+    } else {
+	/* For compatibility with v1.4.  Retrieve the old fill value message.
+ 	 * If size is 0, make it -1 for undefined. */
+        if(NULL == H5O_read(&(dataset->ent), H5O_FILL, 0, &fill_prop)) {
+            H5E_clear();
+            HDmemset(&fill_prop, 0, sizeof(fill_prop));
+        }
+        if(fill_prop.size == 0) {
+	    fill_prop.type = fill_prop.buf = NULL;
+	    fill_prop.size = (size_t)-1;
+	}
+    } /* end else */
+	
+    /* Set fill value properties */ 
+    if(H5P_set(plist, H5D_CRT_FILL_VALUE_NAME, &fill_prop) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, NULL, "can't set fill value");
+    if(H5P_set(plist, H5D_CRT_SPACE_TIME_NAME, &fill.space_time) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, NULL, "can't set fill value");
+    if(H5P_set(plist, H5D_CRT_FILL_TIME_NAME, &fill.fill_time) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, NULL, "can't set fill value");
+
     /* Get the external file list message, which might not exist.  Space is
      * also undefined when space allocate time is H5D_SPACE_ALLOC_LATE. */
     if( !H5F_addr_defined(dataset->layout.addr)) {
@@ -2103,12 +2112,14 @@ H5D_open_oid(H5G_entry_t *ent)
             	HGOTO_ERROR(H5E_DATASET, H5E_CANTSET, NULL, "can't set external file list");
     }
     /*
-     * Make sure all storage is properly initialized for chunked datasets.
-     * This is especially important for parallel I/O where the B-tree must
-     * be fully populated before I/O can happen.
+     * Make sure all storage is properly initialized.
+     * This is important only for parallel I/O where the space must
+     * be fully allocated before I/O can happen.
      */
-    if ((H5F_get_intent(dataset->ent.file) & H5F_ACC_RDWR) && H5D_CHUNKED==dataset->layout.type) {
-        if (H5D_init_storage(dataset, space)<0)
+    if ((H5F_get_intent(dataset->ent.file) & H5F_ACC_RDWR)
+            && (dataset->layout.type!=H5D_COMPACT && dataset->layout.addr==HADDR_UNDEF)
+            && (IS_H5FD_MPIO(dataset->ent.file) || IS_H5FD_MPIPOSIX(dataset->ent.file))) {
+        if (H5D_alloc_storage(dataset->ent.file, dataset,H5D_ALLOC_OPEN)<0)
             HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, NULL, "unable to initialize file storage");
     }
 
@@ -2116,8 +2127,6 @@ H5D_open_oid(H5G_entry_t *ent)
     ret_value = dataset;
 
 done:
-    if (space)
-        H5S_close(space);
     if (ret_value==NULL && dataset) {
         if (H5F_addr_defined(dataset->ent.header))
             H5O_close(&(dataset->ent));
@@ -2360,7 +2369,7 @@ H5D_read(H5D_t *dataset, const H5T_t *mem_type, const H5S_t *mem_space,
      * fill time is NEVER, there is no way to tell whether part of data
      * has been overwritten.  So just proceed in reading.     
      */ 
-    if(nelmts > 0 && efl.nused==0 && dataset->layout.type==H5D_CONTIGUOUS 
+    if(nelmts > 0 && efl.nused==0 && dataset->layout.type!=H5D_COMPACT 
             && dataset->layout.addr==HADDR_UNDEF) {
 
         /* Should be impossible, but check anyway... */
@@ -2695,6 +2704,7 @@ H5D_write(H5D_t *dataset, const H5T_t *mem_type, const H5S_t *mem_space,
     H5O_efl_t   efl;                    /* External File List info */
     H5O_fill_t  fill;                   /* Fill value info */
     H5D_fill_time_t	fill_time;      /* When to write the fill values */
+    H5D_space_time_t    space_time;     /* When to allocate raw data space */
     H5P_genplist_t *dx_plist=NULL;      /* Data transfer property list */
     H5P_genplist_t *dc_plist;           /* Dataset creation roperty list */
     unsigned	sconv_flags=0;	        /* Flags for the space conversion */
@@ -2728,14 +2738,11 @@ H5D_write(H5D_t *dataset, const H5T_t *mem_type, const H5S_t *mem_space,
         mem_space = file_space;                                                                                                          
     nelmts = (*mem_space->select.get_npoints)(mem_space);            
 
-#ifdef H5_HAVE_PARALLEL
     /* If MPIO or MPIPOSIX is used, no VL datatype support yet. */
     /* This is because they use the global heap in the file and we don't */
     /* support parallel access of that yet */
     if ( (IS_H5FD_MPIO(dataset->ent.file) || IS_H5FD_MPIPOSIX(dataset->ent.file)) && H5T_get_class(mem_type)==H5T_VLEN)
         HGOTO_ERROR (H5E_DATASET, H5E_UNSUPPORTED, FAIL, "Parallel IO does not support writing VL datatypes yet");
-#endif /*H5_HAVE_PARALLEL*/
-#ifdef H5_HAVE_PARALLEL
     /* If MPIO or MPIPOSIX is used, no dataset region reference datatype support yet. */
     /* This is because they use the global heap in the file and we don't */
     /* support parallel access of that yet */
@@ -2743,7 +2750,6 @@ H5D_write(H5D_t *dataset, const H5T_t *mem_type, const H5S_t *mem_space,
             H5T_get_class(mem_type)==H5T_REFERENCE &&
             H5T_get_ref_type(mem_type)==H5R_DATASET_REGION)
         HGOTO_ERROR (H5E_DATASET, H5E_UNSUPPORTED, FAIL, "Parallel IO does not support writing region reference datatypes yet");
-#endif /*H5_HAVE_PARALLEL*/
 
     if (0==(H5F_get_intent(dataset->ent.file) & H5F_ACC_RDWR))
 	HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "no write intent on file");
@@ -2794,24 +2800,15 @@ H5D_write(H5D_t *dataset, const H5T_t *mem_type, const H5S_t *mem_space,
         HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't retrieve fill time");
     if(H5P_get(dc_plist, H5D_CRT_EXT_FILE_LIST_NAME, &efl) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't retrieve external file list");
+    if(H5P_get(dc_plist, H5D_CRT_SPACE_TIME_NAME, &space_time) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't retrieve space allocation time");
 
-    /* Allocate data space and initialize it if it hasn't been.  Also modify
-     * header message for layout(this is only for forward compatibility). */
-    if(nelmts > 0 && efl.nused==0 && dataset->layout.type==H5D_CONTIGUOUS &&
+    /* Allocate data space and initialize it if it hasn't been. */
+    if(nelmts > 0 && dataset->layout.type!=H5D_COMPACT &&
             dataset->layout.addr==HADDR_UNDEF) {
  	/* Allocate storage */
-        if(H5F_arr_create(dataset->ent.file, &(dataset->layout))<0)
+        if(H5D_alloc_storage(dataset->ent.file, dataset,H5D_ALLOC_WRITE)<0)
             HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to initialize storage");
-
-        /* Initialize raw data */
-        if(fill_time==H5D_FILL_TIME_ALLOC)
-            if(H5D_init_storage(dataset, file_space) < 0)
-                HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to initialize dataset with fill value");
-
-        /* Update layout message */
-        if (H5O_modify (&(dataset->ent), H5O_LAYOUT, 0, H5O_FLAG_CONSTANT, 
-	    		&(dataset->layout)) < 0)
-            HGOTO_ERROR (H5E_DATASET, H5E_CANTINIT, FAIL, "unable to update layout message");
     } /* end if */
 
     /*
@@ -3084,10 +3081,11 @@ done:
 herr_t
 H5D_extend (H5D_t *dataset, const hsize_t *size)
 {
-    herr_t	changed, ret_value=SUCCEED;
-    H5S_t	*space = NULL;
-    H5O_fill_t  fill;
-    H5P_genplist_t *plist;      /* Property list */
+    int	changed;                        /* Flag to indicate that the dataspace was successfully extended */
+    H5S_t	*space = NULL;          /* Dataset's dataspace */
+    H5D_space_time_t    space_time;     /* When to allocate raw data space */
+    H5P_genplist_t *plist;              /* Property list */
+    herr_t	ret_value=SUCCEED;      /* Return value */
 
     FUNC_ENTER_NOAPI(H5D_extend, FAIL);
 
@@ -3095,6 +3093,12 @@ H5D_extend (H5D_t *dataset, const hsize_t *size)
     assert (dataset);
     assert (size);
 
+    /* Get the dataset creation property list */
+    if (NULL == (plist = H5I_object(dataset->dcpl_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataset creation property list");
+    if(H5P_get(plist, H5D_CRT_SPACE_TIME_NAME, &space_time) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't retrieve space allocation time");
+
     /*
      * NOTE: Restrictions on extensions were checked when the dataset was
      *	     created.  All extensions are allowed here since none should be
@@ -3112,26 +3116,10 @@ H5D_extend (H5D_t *dataset, const hsize_t *size)
 	if (H5S_modify (&(dataset->ent), space)<0)
 	    HGOTO_ERROR (H5E_DATASET, H5E_WRITEERROR, FAIL, "unable to update file with new dataspace");
 
-	/* Initialize the new parts of the dataset */
-#ifdef LATER
-	if (H5S_select_all(space)<0 ||
-                H5S_select_hyperslab(space, H5S_SELECT_DIFF, zero, NULL, old_dims, NULL)<0)
-	    HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to select new extents for fill value");
-#else
-	/*
-	 * We don't have the H5S_SELECT_DIFF operator yet.  We really only
-	 * need it for contiguous datasets because the chunked datasets will
-	 * either fill on demand during I/O or attempt a fill of all chunks.
-	 */
-        if (NULL == (plist = H5I_object(dataset->dcpl_id)))
-            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataset creation property list");
-        if(H5P_get(plist, H5D_CRT_FILL_VALUE_NAME, &fill) < 0)
-            HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't get fill value");
-        if(H5D_CONTIGUOUS == dataset->layout.type && fill.buf) 
-            HGOTO_ERROR(H5E_DATASET, H5E_UNSUPPORTED, FAIL, "unable to select fill value region"); 
-#endif
-	if (H5D_init_storage(dataset, space)<0)
-	    HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to initialize dataset with fill value");
+	/* Allocate space for the new parts of the dataset, if appropriate */
+        if(space_time==H5D_SPACE_ALLOC_EARLY)
+            if (H5D_alloc_storage(dataset->ent.file, dataset, H5D_ALLOC_EXTEND)<0)
+                HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to initialize dataset with fill value");
     } /* end if */
 
 done:
@@ -3226,6 +3214,128 @@ H5D_get_file (const H5D_t *dset)
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5D_alloc_storage
+ *
+ * Purpose:	Allocate storage for the raw data of a dataset.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Robb Matzke
+ *              Friday, January 16, 1998
+ *
+ * Modifications:
+ *              Quincey Koziol
+ *              Thursday, August 22, 2002
+ *              Moved here from H5F_arr_create and moved more logic into
+ *              this function from places where it was being called.
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5D_alloc_storage (H5F_t *f, H5D_t *dset/*in,out*/, H5D_alloc_time_t alloc_time)
+{
+    H5P_genplist_t     *plist;          /* Dataset's creation property list */
+    H5O_efl_t           efl;            /* External File List info */
+    H5D_fill_time_t fill_time;          /* When to write fill values */
+    H5D_space_time_t    space_time;     /* When to allocate raw data space */
+    struct H5O_layout_t *layout;        /* The dataset's layout information */
+    hsize_t	nbytes;                 /* The number of bytes in the dataset */
+    unsigned space_allocated=0;         /* Flag to indicate that space was allocated */
+    unsigned	u;                      /* Local index variable */
+    herr_t      ret_value = SUCCEED;    /* Return value */
+   
+    FUNC_ENTER_NOINIT(H5D_alloc_storage);
+
+    /* check args */
+    assert (f);
+    assert (dset);
+
+    /* Get external file list properties */
+    if (NULL == (plist = H5I_object(dset->dcpl_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataset creation property list");
+    if(H5P_get(plist, H5D_CRT_EXT_FILE_LIST_NAME, &efl) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't retrieve external file list");
+
+    /* If the data is stored in external files, don't set an address for the layout
+     * We assume that external storage is already
+     * allocated by the caller, or at least will be before I/O is performed.
+     */
+    if(efl.nused==0) {
+        /* Get properties needed */
+        if(H5P_get(plist, H5D_CRT_FILL_TIME_NAME, &fill_time) < 0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't retrieve fill time");
+        if(H5P_get(plist, H5D_CRT_SPACE_TIME_NAME, &space_time) < 0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't retrieve space allocation time");
+
+        /* Get a pointer to the dataset's layout information */
+        layout=&(dset->layout);
+
+        switch (layout->type) {
+            case H5D_CONTIGUOUS:
+                if(layout->addr==HADDR_UNDEF) {
+                    /* Reserve space in the file for the entire array */
+                    for (u=0, nbytes=1; u<layout->ndims; u++)
+                        nbytes *= layout->dim[u];
+                    assert (nbytes>0);
+                    if (HADDR_UNDEF==(layout->addr=H5MF_alloc(f, H5FD_MEM_DRAW, nbytes)))
+                        HGOTO_ERROR (H5E_IO, H5E_NOSPACE, FAIL, "unable to reserve file space");
+
+                    /* Indicate that we allocated space */
+                    space_allocated=1;
+                } /* end if */
+                break;
+
+            case H5D_CHUNKED:
+                if(layout->addr==HADDR_UNDEF) {
+                    /* Create the root of the B-tree that describes chunked storage */
+                    if (H5F_istore_create (f, layout/*out*/)<0)
+                        HGOTO_ERROR (H5E_IO, H5E_CANTINIT, FAIL, "unable to initialize chunked storage");
+
+                    /* Indicate that we allocated space */
+                    space_allocated=1;
+                } /* end if */
+                break;
+
+            case H5D_COMPACT:               
+                /* Check if space is already allocated */
+                if(layout->buf==NULL) {
+                    /* Reserve space in layout header message for the entire array. */
+                    assert(layout->size>0);
+                    if (NULL==(layout->buf=H5MM_malloc(layout->size)))
+                        HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, NULL, "unable to allocate memory for compact dataset");
+                    layout->dirty = TRUE;
+
+                    /* Indicate that we allocated space */
+                    space_allocated=1;
+                } /* end if */
+                break;
+                
+            default:
+                assert ("not implemented yet" && 0);
+                HGOTO_ERROR (H5E_IO, H5E_UNSUPPORTED, FAIL, "unsupported storage layout");
+        } /* end switch */
+
+        /* If we are filling the dataset on allocation, do that now */
+        if(fill_time==H5D_FILL_TIME_ALLOC
+                && !(space_time==H5D_SPACE_ALLOC_INCR && alloc_time==H5D_ALLOC_WRITE)) {
+            if(H5D_init_storage(dset) < 0)
+                HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to initialize dataset with fill value");
+        } /* end if */
+
+        /* Also update header message for layout with new address
+          * (this is only for forward compatibility).
+          */
+        if(space_allocated && alloc_time!=H5D_ALLOC_CREATE)
+            if (H5O_modify (&(dset->ent), H5O_LAYOUT, 0, H5O_FLAG_CONSTANT, &(dset->layout)) < 0)
+                HGOTO_ERROR (H5E_DATASET, H5E_CANTINIT, FAIL, "unable to update layout message");
+    } /* end if */
+
+done:
+    FUNC_LEAVE (ret_value);
+} /* end H5D_alloc_storage() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5D_init_storage
  *
  * Purpose:	Initialize the data for a new dataset.  If a selection is
@@ -3247,32 +3357,31 @@ H5D_get_file (const H5D_t *dset)
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5D_init_storage(H5D_t *dset, const H5S_t *space)
+H5D_init_storage(H5D_t *dset)
 {
     hssize_t            snpoints;       /* Number of points in space (for error checking) */
     size_t              npoints;        /* Number of points in space */
-    size_t              ptsperbuf;      /* Maximum # of points which fit in the buffer */
-    size_t		bufsize=64*1024;    /* Size of buffer to write */
-    size_t		size;           /* Current # of points to write */
-    hsize_t		addr;           /* Offset in dataset */
-    void		*buf = NULL;    /* Buffer for fill value writing */
+    H5S_t	        *space = NULL;	/* Dataset's dataspace */
     H5O_fill_t          fill;           /* Fill value information */
-    H5D_space_time_t    space_time;     /* When to allocate space */
+    H5O_efl_t           efl;            /* External File List info */
     H5P_genplist_t     *plist;          /* Property list */
     herr_t		ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_NOINIT(H5D_init_storage);
 
     assert(dset);
-    assert(space);
 
     /* Get fill value, external file list, and data pipeline properties */
     if (NULL == (plist = H5I_object(dset->dcpl_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataset creation property list");
     if(H5P_get(plist, H5D_CRT_FILL_VALUE_NAME, &fill) < 0)
         HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't get fill value");
-    if(H5P_get(plist, H5D_CRT_SPACE_TIME_NAME, &space_time) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't retrieve space allocation time");
+    if(H5P_get(plist, H5D_CRT_EXT_FILE_LIST_NAME, &efl) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't retrieve external file list");
+
+    /* Get the dataset's dataspace */
+    if (NULL==(space=H5S_read (&(dset->ent))))
+        HGOTO_ERROR (H5E_DATASET, H5E_CANTINIT, FAIL, "unable to read data space from dataset header");
 
     /* Get the number of elements in the dataset's dataspace */
     snpoints = H5S_get_simple_extent_npoints(space);
@@ -3290,54 +3399,17 @@ H5D_init_storage(H5D_t *dset, const H5S_t *space)
             break;
 
         case H5D_CONTIGUOUS:
-            /* If fill value is library default, get the dataset's type's size */
-            if(!fill.buf) {
-                fill.size=H5T_get_size(dset->type);
-                assert(fill.size);
-            } /* end if */
-            
-            /*
-             * Fill the entire current extent with the fill value.  We can do
-             * this quite efficiently by making sure we copy the fill value
-             * in relatively large pieces.
-             */
-             ptsperbuf = MAX(1, bufsize/fill.size);
-             bufsize = ptsperbuf*fill.size;
-
-             /* Allocate temporary buffer */
-             if ((buf=H5FL_BLK_ALLOC(type_conv,bufsize,0))==NULL)
-                 HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for fill buffer");
-
-             /* Fill the buffer with the user's fill value */
-             if(fill.buf)
-                H5V_array_fill(buf, fill.buf, fill.size, ptsperbuf);
-             else /* Fill the buffer with the default fill value */
-                HDmemset(buf,0,bufsize);
-             
-             /* Start at the beginning of the dataset */
-             addr = 0;
-
-             /* Loop through writing the fill value to the dataset */
-             while (npoints>0) {
-                  size = MIN(ptsperbuf, npoints) * fill.size;
-                  if (H5F_seq_write(dset->ent.file, H5P_DATASET_XFER_DEFAULT,
-                          &(dset->layout), plist, space, fill.size, size, addr, buf)<0)
-                      HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to write fill value to dataset");
-                  npoints -= MIN(ptsperbuf, npoints);
-                  addr += size;
-              } /* end while */
+            if (H5F_contig_fill(dset->ent.file, H5P_DATASET_XFER_DEFAULT,
+                     &(dset->layout), plist, space, H5T_get_size(dset->type))<0)
+                HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to allocate all chunks of dataset");
              break;
 
         case H5D_CHUNKED:
             /*        
-             * If the dataset is accessed via parallel I/O, allocate file space                    
+             * Allocate file space                    
              * for all chunks now and initialize each chunk with the fill value.                                 
              */
-            if (space_time==H5D_SPACE_ALLOC_EARLY
-#ifdef H5_HAVE_PARALLEL
-                    || (IS_H5FD_MPIO(dset->ent.file) || IS_H5FD_MPIPOSIX(dset->ent.file))
-#endif /*H5_HAVE_PARALLEL*/
-                    ) {
+            {
                 /* We only handle simple data spaces so far */
                 int             ndims;
                 hsize_t         dim[H5O_LAYOUT_NDIMS];
@@ -3345,7 +3417,6 @@ H5D_init_storage(H5D_t *dset, const H5S_t *space)
                 if ((ndims=H5S_get_simple_extent_dims(space, dim, NULL))<0)
                      HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to get simple data space info");
                 dim[ndims] = dset->layout.dim[ndims];
-                ndims++;
 
                 if (H5F_istore_allocate(dset->ent.file, H5P_DATASET_XFER_DEFAULT,
                          &(dset->layout), dim, plist)<0)
@@ -3355,8 +3426,8 @@ H5D_init_storage(H5D_t *dset, const H5S_t *space)
     } /* end switch */
     
 done:
-    if (buf)
-        H5FL_BLK_FREE(type_conv,buf);
+    if (space)
+        H5S_close(space);
 
     FUNC_LEAVE(ret_value);
 }
@@ -3430,23 +3501,29 @@ H5D_get_storage_size(H5D_t *dset)
 
     switch(dset->layout.type) {
         case H5D_CHUNKED:
-            ret_value = H5F_istore_allocated(dset->ent.file, dset->layout.ndims,
+            if(dset->layout.addr == HADDR_UNDEF)
+                ret_value=0;
+            else
+                ret_value = H5F_istore_allocated(dset->ent.file, dset->layout.ndims,
                                              dset->layout.addr);
             break;
+
         case H5D_CONTIGUOUS:
             /* Datasets which are not allocated yet are using no space on disk */
             if(dset->layout.addr == HADDR_UNDEF)
-                 ret_value=0;
+                ret_value=0;
             else {
                  for (u=0, ret_value=1; u<dset->layout.ndims; u++)
                      ret_value *= dset->layout.dim[u];
             } /* end else */
             break;
+
         case H5D_COMPACT:
             ret_value = dset->layout.size;
             break;
+
         default:
-            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataset type");
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "not a dataset type");
     }
      
 done:
@@ -4001,8 +4078,11 @@ H5D_set_extent(H5D_t *dset, const hsize_t *size)
     herr_t                  ret_value = SUCCEED;        /* Return value */
     H5S_t                  *space = NULL;
     H5P_genplist_t         *plist;
+    H5D_space_time_t        space_time;         /* When to allocate raw data space */
     int                     u;
-    int                     shrink = 0;
+    unsigned                shrink = 0;         /* Flag to indicate a dimension has shrank */
+    unsigned                expand = 0;         /* Flag to indicate a dimension has grown */
+    int                     changed = 0;
 
     FUNC_ENTER_NOAPI(H5D_set_extent, FAIL);
 
@@ -4018,56 +4098,62 @@ H5D_set_extent(H5D_t *dset, const hsize_t *size)
 	HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to read data space info from dset header");
 
  /*-------------------------------------------------------------------------
-  * Check if we are shrinking in any of the dimensions
+  * Check if we are shrinking or expanding any of the dimensions
   *-------------------------------------------------------------------------
   */
     if((rank = H5S_get_simple_extent_dims(space, curr_dims, NULL)) < 0)
 	HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't get dataset dimensions");
 
     for(u = 0; u < rank; u++) {
-	if(size[u] < curr_dims[u]) {
+	if(size[u] < curr_dims[u])
 	    shrink = 1;
-	    break;
-	}
+	if(size[u] > curr_dims[u])
+	    expand = 1;
     }
 
  /*-------------------------------------------------------------------------
   * Modify the size of the data space
   *-------------------------------------------------------------------------
   */
-    if(H5S_set_extent(space, size) < 0)
+    if((changed=H5S_set_extent(space, size)) < 0)
 	HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to modify size of data space");
 
- /*-------------------------------------------------------------------------
-  * Modify the dataset storage
-  *-------------------------------------------------------------------------
-  */
-    /* Save the new dataspace in the file if necessary */
-    if(H5S_modify(&(dset->ent), space) < 0)
-        HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "unable to update file with new dataspace");
-
-    /* Initialize the new parts of the dset */
-    if(H5D_init_storage(dset, space) < 0)
-        HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to initialize dataset storage");
-
-
- /*-------------------------------------------------------------------------
-  * Remove chunk information in the case of chunked datasets
-  * This removal takes place only in case we are shrinking the dateset
-  *-------------------------------------------------------------------------
-  */
-    if(shrink && H5D_CHUNKED == dset->layout.type) {
-        /* Remove excess chunks */
-	if(H5F_istore_prune_by_extent(dset->ent.file, &dset->layout, space) < 0)
-	    HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "unable to remove chunks ");
-
+    /* Don't bother updating things, unless they've changed */
+    if(changed) {
         /* Get the dataset creation property list */
-	if(NULL == (plist = H5I_object(dset->dcpl_id)))
-	    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dset creation property list");
-
-        /* Reset the elements outsize the new dimensions, but in existing chunks */
-	if(H5F_istore_initialize_by_extent(dset->ent.file, &dset->layout, plist, space) < 0)
-	    HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "unable to initialize chunks ");
+        if(NULL == (plist = H5I_object(dset->dcpl_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dset creation property list");
+        if(H5P_get(plist, H5D_CRT_SPACE_TIME_NAME, &space_time) < 0)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't retrieve space allocation time");
+
+     /*-------------------------------------------------------------------------
+      * Modify the dataset storage
+      *-------------------------------------------------------------------------
+      */
+        /* Save the new dataspace in the file if necessary */
+        if(H5S_modify(&(dset->ent), space) < 0)
+            HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "unable to update file with new dataspace");
+
+	/* Allocate space for the new parts of the dataset, if appropriate */
+        if(expand && space_time==H5D_SPACE_ALLOC_EARLY)
+            if(H5D_alloc_storage(dset->ent.file, dset, H5D_ALLOC_EXTEND) < 0)
+                HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to initialize dataset storage");
+
+
+     /*-------------------------------------------------------------------------
+      * Remove chunk information in the case of chunked datasets
+      * This removal takes place only in case we are shrinking the dateset
+      *-------------------------------------------------------------------------
+      */
+        if(shrink && H5D_CHUNKED == dset->layout.type) {
+            /* Remove excess chunks */
+            if(H5F_istore_prune_by_extent(dset->ent.file, &dset->layout, space) < 0)
+                HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "unable to remove chunks ");
+
+            /* Reset the elements outsize the new dimensions, but in existing chunks */
+            if(H5F_istore_initialize_by_extent(dset->ent.file, &dset->layout, plist, space) < 0)
+                HGOTO_ERROR(H5E_DATASET, H5E_WRITEERROR, FAIL, "unable to initialize chunks ");
+        } /* end if */
     } /* end if */
 
 done:
diff --git a/src/H5Dcompact.c b/src/H5Dcompact.c
index 3a36edb..0a21211 100644
--- a/src/H5Dcompact.c
+++ b/src/H5Dcompact.c
@@ -44,9 +44,9 @@ static int              interface_initialize_g = 0;
  *-------------------------------------------------------------------------
  */
 herr_t
-H5F_compact_readv(H5F_t *f, const H5O_layout_t *layout, size_t nseq, 
+H5F_compact_readv(H5F_t UNUSED *f, const H5O_layout_t *layout, size_t nseq, 
                   size_t size_arr[], hsize_t offset_arr[], 
-                  hid_t dxpl_id, void *_buf/*out*/)
+                  hid_t UNUSED dxpl_id, void *_buf/*out*/)
 {
     unsigned char       *buf=(unsigned char *)_buf;
     size_t              size;
@@ -93,11 +93,11 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5F_compact_writev(H5F_t *f, H5O_layout_t *layout, size_t nseq,
+H5F_compact_writev(H5F_t UNUSED *f, H5O_layout_t *layout, size_t nseq,
                   size_t size_arr[], hsize_t offset_arr[], 
-                  hid_t dxpl_id, const void *_buf)
+                  hid_t UNUSED dxpl_id, const void *_buf)
 {
-    unsigned char       *buf=(unsigned char *)_buf;
+    const unsigned char       *buf=(const unsigned char *)_buf;
     size_t              size;
     haddr_t             offset;
     unsigned            u;
diff --git a/src/H5Dcontig.c b/src/H5Dcontig.c
index 89f9fc5..fce1ba9 100644
--- a/src/H5Dcontig.c
+++ b/src/H5Dcontig.c
@@ -14,11 +14,19 @@
 
 #define H5F_PACKAGE		/*suppress error about including H5Fpkg	  */
 
-#include "H5private.h"
-#include "H5Eprivate.h"
+#include "H5private.h"		/* Generic Functions			*/
+#include "H5Dprivate.h"		/* Dataset functions			*/
+#include "H5Eprivate.h"		/* Error handling		  	*/
 #include "H5Fpkg.h"
 #include "H5FDprivate.h"	/*file driver				  */
 #include "H5FLprivate.h"	/*Free Lists	  */
+#include "H5Oprivate.h"		/* Object headers		  	*/
+#include "H5Pprivate.h"		/* Property lists			*/
+#include "H5Vprivate.h"		/* Vector and array functions		*/
+
+/* MPIO & MPIPOSIX drivers needed for special checks */
+#include "H5FDmpio.h"
+#include "H5FDmpiposix.h"
 
 /* Interface initialization */
 #define PABLO_MASK	H5Fcontig_mask
@@ -28,6 +36,187 @@ static int		interface_initialize_g = 0;
 /* Declare a PQ free list to manage the sieve buffer information */
 H5FL_BLK_DEFINE(sieve_buf);
 
+/* Extern the free list to manage blocks of type conversion data */
+H5FL_BLK_EXTERN(type_conv);
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_contig_fill
+ *
+ * Purpose:	Write fill values to a contiguously stored dataset.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Quincey Koziol
+ *		August 22, 2002
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5F_contig_fill(H5F_t *f, hid_t dxpl_id, struct H5O_layout_t *layout,
+    struct H5P_genplist_t *dc_plist, const struct H5S_t *space,
+    size_t elmt_size)
+{
+    H5O_fill_t  fill;           /* Fill value information */
+    H5O_efl_t   efl;            /* External File List info */
+    hssize_t    snpoints;       /* Number of points in space (for error checking) */
+    size_t      npoints;        /* Number of points in space */
+    size_t      ptsperbuf;      /* Maximum # of points which fit in the buffer */
+    size_t	bufsize=64*1024; /* Size of buffer to write */
+    size_t	size;           /* Current # of points to write */
+    hsize_t	addr;           /* Offset in dataset */
+    void       *buf = NULL;     /* Buffer for fill value writing */
+#ifdef H5_HAVE_PARALLEL
+    MPI_Comm	mpi_comm=MPI_COMM_NULL;	/* MPI communicator for file */
+    int         mpi_rank=(-1);  /* This process's rank  */
+    int         mpi_size=(-1);  /* Total # of processes */
+    int         mpi_round=0;    /* Current process responsible for I/O */
+    int         mpi_code;       /* MPI return code */
+    unsigned    blocks_written=0; /* Flag to indicate that chunk was actually written */
+    unsigned    using_mpi=0;    /* Flag to indicate that the file is being accessed with an MPI-capable file driver */
+#endif /* H5_HAVE_PARALLEL */
+    herr_t	ret_value=SUCCEED;	/* Return value */
+    
+    FUNC_ENTER_NOAPI(H5F_contig_fill, FAIL);
+
+    /* Check args */
+    assert(f);
+    assert(TRUE==H5P_isa_class(dxpl_id,H5P_DATASET_XFER));
+    assert(layout && H5D_CONTIGUOUS==layout->type);
+    assert(layout->ndims>0 && layout->ndims<=H5O_LAYOUT_NDIMS);
+    assert(H5F_addr_defined(layout->addr));
+    assert(dc_plist!=NULL);
+    assert(space);
+    assert(elmt_size>0);
+
+    /* Get necessary properties from dataset creation property list */
+    if(H5P_get(dc_plist, H5D_CRT_FILL_VALUE_NAME, &fill) < 0)
+        HGOTO_ERROR(H5E_STORAGE, H5E_CANTGET, FAIL, "can't get fill value");
+    if(H5P_get(dc_plist, H5D_CRT_EXT_FILE_LIST_NAME, &efl) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't retrieve external file list");
+
+#ifdef H5_HAVE_PARALLEL
+    /* Retrieve up MPI parameters */
+    if(IS_H5FD_MPIO(f)) {
+        /* Get the MPI communicator */
+        if (MPI_COMM_NULL == (mpi_comm=H5FD_mpio_communicator(f->shared->lf)))
+            HGOTO_ERROR(H5E_INTERNAL, H5E_MPI, FAIL, "Can't retrieve MPI communicator");
+
+        /* Get the MPI rank & size */
+        if ((mpi_rank=H5FD_mpio_mpi_rank(f->shared->lf))<0)
+            HGOTO_ERROR(H5E_INTERNAL, H5E_MPI, FAIL, "Can't retrieve MPI rank");
+        if ((mpi_size=H5FD_mpio_mpi_size(f->shared->lf))<0)
+            HGOTO_ERROR(H5E_INTERNAL, H5E_MPI, FAIL, "Can't retrieve MPI size");
+
+        /* Set the MPI-capable file driver flag */
+        using_mpi=1;
+    } /* end if */
+    else {
+        if(IS_H5FD_MPIPOSIX(f)) {
+            /* Get the MPI communicator */
+            if (MPI_COMM_NULL == (mpi_comm=H5FD_mpiposix_communicator(f->shared->lf)))
+                HGOTO_ERROR(H5E_INTERNAL, H5E_MPI, FAIL, "Can't retrieve MPI communicator");
+
+            /* Get the MPI rank & size */
+            if ((mpi_rank=H5FD_mpiposix_mpi_rank(f->shared->lf))<0)
+                HGOTO_ERROR(H5E_INTERNAL, H5E_MPI, FAIL, "Can't retrieve MPI rank");
+            if ((mpi_size=H5FD_mpiposix_mpi_size(f->shared->lf))<0)
+                HGOTO_ERROR(H5E_INTERNAL, H5E_MPI, FAIL, "Can't retrieve MPI size");
+
+            /* Set the MPI-capable file driver flag */
+            using_mpi=1;
+        } /* end if */
+    } /* end else */
+#endif /* H5_HAVE_PARALLEL */
+
+    /* Get the number of elements in the dataset's dataspace */
+    snpoints = H5S_get_simple_extent_npoints(space);
+    assert(snpoints>=0);
+    H5_ASSIGN_OVERFLOW(npoints,snpoints,hssize_t,size_t);
+
+    /* Don't write default fill-values to external files */
+    if(efl.nused>0 && !fill.buf)
+        HGOTO_DONE(SUCCEED);
+
+    /* If fill value is library default, use the element size */
+    if(!fill.buf)
+        fill.size=elmt_size;
+
+    /*
+     * Fill the entire current extent with the fill value.  We can do
+     * this quite efficiently by making sure we copy the fill value
+     * in relatively large pieces.
+     */
+     ptsperbuf = MAX(1, bufsize/fill.size);
+     bufsize = ptsperbuf*fill.size;
+
+     /* Allocate temporary buffer */
+     if ((buf=H5FL_BLK_ALLOC(type_conv,bufsize,0))==NULL)
+         HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for fill buffer");
+
+     /* Fill the buffer with the user's fill value */
+     if(fill.buf)
+        H5V_array_fill(buf, fill.buf, fill.size, ptsperbuf);
+     else /* Fill the buffer with the default fill value */
+        HDmemset(buf,0,bufsize);
+     
+     /* Start at the beginning of the dataset */
+     addr = 0;
+
+     /* Loop through writing the fill value to the dataset */
+     while (npoints>0) {
+          size = MIN(ptsperbuf, npoints) * fill.size;
+
+#ifdef H5_HAVE_PARALLEL
+            /* Check if this file is accessed with an MPI-capable file driver */
+            if(using_mpi) {
+                /* Round-robin write the chunks out from only one process */
+                if(mpi_round==mpi_rank) {
+                    if (H5F_seq_write(f, dxpl_id, layout, dc_plist, space,
+                            fill.size, size, addr, buf)<0)
+                        HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to write fill value to dataset");
+                } /* end if */
+                mpi_round=(++mpi_round)%mpi_size;
+
+                /* Indicate that blocks are being written */
+                blocks_written=1;
+            } /* end if */
+            else {
+#endif /* H5_HAVE_PARALLEL */
+                if (H5F_seq_write(f, dxpl_id, layout, dc_plist, space,
+                        fill.size, size, addr, buf)<0)
+                    HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to write fill value to dataset");
+#ifdef H5_HAVE_PARALLEL
+            } /* end else */
+#endif /* H5_HAVE_PARALLEL */
+
+          npoints -= MIN(ptsperbuf, npoints);
+          addr += size;
+      } /* end while */
+            
+#ifdef H5_HAVE_PARALLEL
+    /* Only need to block at the barrier if we actually wrote fill values */
+    /* And if we are using an MPI-capable file driver */
+    if(using_mpi && blocks_written) {
+        /* Wait at barrier to avoid race conditions where some processes are
+         * still writing out fill values and other processes race ahead to data
+         * in, getting bogus data.
+         */
+        if (MPI_SUCCESS != (mpi_code=MPI_Barrier(mpi_comm)))
+            HMPI_GOTO_ERROR(FAIL, "MPI_Barrier failed", mpi_code);
+    } /* end if */
+#endif /* H5_HAVE_PARALLEL */
+
+done:
+    /* Free the buffer for fill values */
+    if (buf)
+        H5FL_BLK_FREE(type_conv,buf);
+
+    FUNC_LEAVE(ret_value);
+}
+
 
 /*-------------------------------------------------------------------------
  * Function:	H5F_contig_read
diff --git a/src/H5Distore.c b/src/H5Distore.c
index 0bba74e..f36b6200 100644
--- a/src/H5Distore.c
+++ b/src/H5Distore.c
@@ -1758,7 +1758,6 @@ H5F_istore_read(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
         if ((chunk_size>f->shared->rdcc_nbytes && pline.nfilters==0 &&
                 chunk_addr!=HADDR_UNDEF)
 
-#ifdef H5_HAVE_PARALLEL
         /*
          * If MPIO or MPIPOSIX is used and file can be written to, we must bypass the
          * chunk-cache scheme because other MPI processes could be writing to
@@ -1766,7 +1765,6 @@ H5F_istore_read(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
          * Do a direct write-through of only the elements requested.
          */
             || ((IS_H5FD_MPIO(f) ||IS_H5FD_MPIPOSIX(f)) && (H5F_ACC_RDWR & f->shared->flags))
-#endif /* H5_HAVE_PARALLEL */
             ) {
             H5O_layout_t	l;	/* temporary layout */
 
@@ -1942,14 +1940,12 @@ H5F_istore_write(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
         if ((chunk_size>f->shared->rdcc_nbytes && pline.nfilters==0 &&
                 chunk_addr!=HADDR_UNDEF)
 
-#ifdef H5_HAVE_PARALLEL
         /*
          * If MPIO or MPIPOSIX is used, must bypass the chunk-cache scheme because other
          * MPI processes could be writing to other elements in the same chunk.
          * Do a direct write-through of only the elements requested.
          */
             || ((IS_H5FD_MPIO(f) ||IS_H5FD_MPIPOSIX(f)) && (H5F_ACC_RDWR & f->shared->flags))
-#endif /* H5_HAVE_PARALLEL */
             ) {
             H5O_layout_t	l;	/* temporary layout */
 
@@ -2334,6 +2330,7 @@ H5F_istore_allocate(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
     H5P_genplist_t *dx_plist;   /* Data xfer property list */
     double	split_ratios[3];/* B-tree node splitting ratios		*/
 #ifdef H5_HAVE_PARALLEL
+    MPI_Comm	mpi_comm=MPI_COMM_NULL;	/* MPI communicator for file */
     int         mpi_rank=(-1);  /* This process's rank  */
     int         mpi_size=(-1);  /* Total # of processes */
     int         mpi_round=0;    /* Current process responsible for I/O */
@@ -2342,6 +2339,7 @@ H5F_istore_allocate(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
     unsigned    using_mpi=0;    /* Flag to indicate that the file is being accessed with an MPI-capable file driver */
 #endif /* H5_HAVE_PARALLEL */
     int		carry;          /* Flag to indicate that chunk increment carrys to higher dimension (sorta) */
+    unsigned	chunk_exists;   /* Flag to indicate whether a chunk exists already */
     int		i;              /* Local index variable */
     unsigned	u;              /* Local index variable */
     herr_t	ret_value=SUCCEED;	/* Return value */
@@ -2374,6 +2372,11 @@ H5F_istore_allocate(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
 #ifdef H5_HAVE_PARALLEL
     /* Retrieve up MPI parameters */
     if(IS_H5FD_MPIO(f)) {
+        /* Get the MPI communicator */
+        if (MPI_COMM_NULL == (mpi_comm=H5FD_mpio_communicator(f->shared->lf)))
+            HGOTO_ERROR(H5E_INTERNAL, H5E_MPI, FAIL, "Can't retrieve MPI communicator");
+
+        /* Get the MPI rank & size */
         if ((mpi_rank=H5FD_mpio_mpi_rank(f->shared->lf))<0)
             HGOTO_ERROR(H5E_INTERNAL, H5E_MPI, FAIL, "Can't retrieve MPI rank");
         if ((mpi_size=H5FD_mpio_mpi_size(f->shared->lf))<0)
@@ -2384,6 +2387,10 @@ H5F_istore_allocate(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
     } /* end if */
     else {
         if(IS_H5FD_MPIPOSIX(f)) {
+            /* Get the MPI communicator */
+            if (MPI_COMM_NULL == (mpi_comm=H5FD_mpiposix_communicator(f->shared->lf)))
+                HGOTO_ERROR(H5E_INTERNAL, H5E_MPI, FAIL, "Can't retrieve MPI communicator");
+
             /* Get the MPI rank & size */
             if ((mpi_rank=H5FD_mpiposix_mpi_rank(f->shared->lf))<0)
                 HGOTO_ERROR(H5E_INTERNAL, H5E_MPI, FAIL, "Can't retrieve MPI rank");
@@ -2396,12 +2403,6 @@ H5F_istore_allocate(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
     } /* end else */
 #endif /* H5_HAVE_PARALLEL */
 
-#ifdef H5_HAVE_PARALLEL
-    /* Can't use data I/O pipeline in parallel (yet) */
-    if (using_mpi && pline.nfilters>0)
-        HGOTO_ERROR(H5E_STORAGE, H5E_UNSUPPORTED, FAIL, "can't use data pipeline in parallel");
-#endif /* H5_HAVE_PARALLEL */
-
     /*
      * Setup indice to go through all chunks. (Future improvement
      * should allocate only chunks that have no file space assigned yet.
@@ -2450,8 +2451,32 @@ H5F_istore_allocate(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
     /* Loop over all chunks */
     carry=0;
     while (carry==0) {
-        /* Check if the chunk exists yet */
+        /* Check if the chunk exists yet on disk */
+        chunk_exists=1;
         if(H5F_istore_get_addr(f,layout,chunk_offset)==HADDR_UNDEF) {
+            H5F_rdcc_t             *rdcc = &(f->shared->rdcc);	/*raw data chunk cache */
+            H5F_rdcc_ent_t         *ent = NULL;              	/*cache entry  */
+
+            /* Didn't find the chunk on disk */
+            chunk_exists = 0;
+
+            /* Look for chunk in cache */
+            for(ent = rdcc->head; ent && !chunk_exists; ent = ent->next) {
+                /* Make certain we are dealing with the correct B-tree, etc */
+                if (layout->ndims==ent->layout->ndims &&
+                        H5F_addr_eq(layout->addr, ent->layout->addr)) {
+
+                    /* Assume a match */
+                    chunk_exists = 1;
+                    for(u = 0; u < layout->ndims && chunk_exists; u++) {
+                        if(ent->offset[u] != chunk_offset[u])
+                            chunk_exists = 0;       /* Reset if no match */
+                    } /* end for */
+                } /* end if */
+            } /* end for */
+        } /* end if */
+
+        if(!chunk_exists) {
             /* Initialize the chunk information */
             udata.mesg = *layout;
             udata.key.filter_mask = 0;
@@ -2507,17 +2532,8 @@ H5F_istore_allocate(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
          * still writing out chunks and other processes race ahead to read
          * them in, getting bogus data.
          */
-        if(IS_H5FD_MPIO(f)) {
-            if (MPI_SUCCESS != (mpi_code=MPI_Barrier(H5FD_mpio_communicator(f->shared->lf))))
-                HMPI_GOTO_ERROR(FAIL, "MPI_Barrier failed", mpi_code);
-        } /* end if */
-        else {
-            /* Sanity Check */
-            assert(IS_H5FD_MPIPOSIX(f));
-
-            if (MPI_SUCCESS!=(mpi_code=MPI_Barrier(H5FD_mpiposix_communicator(f->shared->lf))))
-                HMPI_GOTO_ERROR(FAIL, "MPI_Barrier failed", mpi_code);
-        } /* end else */
+        if (MPI_SUCCESS != (mpi_code=MPI_Barrier(mpi_comm)))
+            HMPI_GOTO_ERROR(FAIL, "MPI_Barrier failed", mpi_code);
     } /* end if */
 #endif /* H5_HAVE_PARALLEL */
 
@@ -2662,13 +2678,17 @@ H5F_istore_prune_by_extent(H5F_t *f, const H5O_layout_t *layout, const H5S_t * s
     for(ent = rdcc->head; ent; ent = next) {
 	next = ent->next;
 
-	found = 0;
-	for(u = 0; u < ent->layout->ndims - 1; u++) {
-	    if((hsize_t)ent->offset[u] > curr_dims[u]) {
-		found = 1;
-		break;
-	    }
-	}
+        /* Make certain we are dealing with the correct B-tree, etc */
+        if (layout->ndims==ent->layout->ndims &&
+                H5F_addr_eq(layout->addr, ent->layout->addr)) {
+            found = 0;
+            for(u = 0; u < ent->layout->ndims - 1; u++) {
+                if((hsize_t)ent->offset[u] > curr_dims[u]) {
+                    found = 1;
+                    break;
+                }
+            }
+        } /* end if */
 
 	if(found) {
 #if defined (H5F_ISTORE_DEBUG)
diff --git a/src/H5Dprivate.h b/src/H5Dprivate.h
index a60c041..d1d0a02 100644
--- a/src/H5Dprivate.h
+++ b/src/H5Dprivate.h
@@ -63,7 +63,7 @@
 /* Definitions for space allocation time */
 #define H5D_CRT_SPACE_TIME_NAME   "space_time"
 #define H5D_CRT_SPACE_TIME_SIZE   sizeof(H5D_space_time_t)
-#define H5D_CRT_SPACE_TIME_DEF    H5D_SPACE_ALLOC_LATE
+#define H5D_CRT_SPACE_TIME_DEF    H5D_SPACE_ALLOC_DEFAULT
 /* Definitions for time of fill value writing */
 #define H5D_CRT_FILL_TIME_NAME     "fill_time"
 #define H5D_CRT_FILL_TIME_SIZE     sizeof(H5D_fill_time_t)
diff --git a/src/H5Dpublic.h b/src/H5Dpublic.h
index 855f05f..3cad621 100644
--- a/src/H5Dpublic.h
+++ b/src/H5Dpublic.h
@@ -33,8 +33,10 @@ typedef enum H5D_layout_t {
 /* Values for the space allocation time property */
 typedef enum H5D_space_time_t {
     H5D_SPACE_ALLOC_ERROR	=-1,
-    H5D_SPACE_ALLOC_LATE  	=0,
-    H5D_SPACE_ALLOC_EARLY	=1
+    H5D_SPACE_ALLOC_DEFAULT  	=0,
+    H5D_SPACE_ALLOC_EARLY	=1,
+    H5D_SPACE_ALLOC_LATE	=2,
+    H5D_SPACE_ALLOC_INCR	=3
 } H5D_space_time_t;   
 
 /* Values for the status of space allocation */
diff --git a/src/H5FDmpio.h b/src/H5FDmpio.h
index c5133f3..f1dd6f7 100644
--- a/src/H5FDmpio.h
+++ b/src/H5FDmpio.h
@@ -34,8 +34,12 @@ typedef struct H5FD_mpio_dxpl_t {
     H5FD_mpio_xfer_t	xfer_mode;	/*collective or independent I/O	*/
 } H5FD_mpio_dxpl_t;
     
-#ifdef H5_HAVE_PARALLEL
 /* Macros */
+
+#define IS_H5FD_MPIO(f)	/* (H5F_t *f) */				    \
+    (H5FD_MPIO==H5F_get_driver_id(f))
+
+#ifdef H5_HAVE_PARALLEL
 /*Turn on H5FDmpio_debug if H5F_DEBUG is on */
 #ifdef H5F_DEBUG
 #ifndef H5FDmpio_DEBUG
@@ -43,9 +47,6 @@ typedef struct H5FD_mpio_dxpl_t {
 #endif
 #endif
 
-#define IS_H5FD_MPIO(f)	/* (H5F_t *f) */				    \
-    (H5FD_MPIO==H5F_get_driver_id(f))
-
 /* Function prototypes */
 #ifdef __cplusplus
 extern "C" {
diff --git a/src/H5FDmpiposix.h b/src/H5FDmpiposix.h
index 81d05d4..3f262e1 100644
--- a/src/H5FDmpiposix.h
+++ b/src/H5FDmpiposix.h
@@ -31,13 +31,13 @@
 #   define H5FD_MPIPOSIX	(-1)
 #endif
 
-#ifdef H5_HAVE_PARALLEL
-
 /* Macros */
 
 #define IS_H5FD_MPIPOSIX(f)	/* (H5F_t *f) */				    \
     (H5FD_MPIPOSIX==H5F_get_driver_id(f))
 
+#ifdef H5_HAVE_PARALLEL
+
 /* Function prototypes */
 #ifdef __cplusplus
 extern "C" {
diff --git a/src/H5Farray.c b/src/H5Farray.c
index e3657d0..8e01099 100644
--- a/src/H5Farray.c
+++ b/src/H5Farray.c
@@ -20,7 +20,6 @@
 #include "H5Fpkg.h"
 #include "H5FDprivate.h"	/*file driver				  */
 #include "H5Iprivate.h"
-#include "H5MFprivate.h"
 #include "H5MMprivate.h"	/*memory management			  */
 #include "H5Oprivate.h"
 #include "H5Pprivate.h"
@@ -37,69 +36,6 @@ static int interface_initialize_g = 0;
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5F_arr_create
- *
- * Purpose:	Creates an array of bytes.
- *
- * Return:	Non-negative on success/Negative on failure
- *
- * Programmer:	Robb Matzke
- *              Friday, January 16, 1998
- *
- * Modifications:
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5F_arr_create (H5F_t *f, struct H5O_layout_t *layout/*in,out*/)
-{
-    unsigned	u;
-    hsize_t	nbytes;
-    herr_t      ret_value = SUCCEED;            /* Return value */
-   
-    FUNC_ENTER_NOAPI(H5F_arr_create, FAIL);
-
-    /* check args */
-    assert (f);
-    assert (layout);
-    layout->addr = HADDR_UNDEF; /*just in case we fail*/
-   
-    switch (layout->type) {
-        case H5D_CONTIGUOUS:
-            /* Reserve space in the file for the entire array */
-            for (u=0, nbytes=1; u<layout->ndims; u++)
-                nbytes *= layout->dim[u];
-            assert (nbytes>0);
-            if (HADDR_UNDEF==(layout->addr=H5MF_alloc(f, H5FD_MEM_DRAW, nbytes)))
-                HGOTO_ERROR (H5E_IO, H5E_NOSPACE, FAIL, "unable to reserve file space");
-            break;
-
-        case H5D_CHUNKED:
-            /* Create the root of the B-tree that describes chunked storage */
-            if (H5F_istore_create (f, layout/*out*/)<0)
-                HGOTO_ERROR (H5E_IO, H5E_CANTINIT, FAIL, "unable to initialize chunked storage");
-            break;
-
-        case H5D_COMPACT:               
-            /* Reserve space in layout header message for the entire array. */
-            assert(layout->size>0);
-            if (NULL==(layout->buf=H5MM_malloc(layout->size)))
-                HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, NULL, "unable to allocate memory for compact dataset");
-            layout->dirty = TRUE;
-            break;
-            
-        default:
-            assert ("not implemented yet" && 0);
-            HGOTO_ERROR (H5E_IO, H5E_UNSUPPORTED, FAIL,
-                   "unsupported storage layout");
-    } /* end switch */
-
-done:
-    FUNC_LEAVE (ret_value);
-}
-
-
-/*-------------------------------------------------------------------------
  * Function:	H5F_arr_read
  *
  * Purpose:	Reads a hyperslab of a file byte array into a hyperslab of
diff --git a/src/H5Fcompact.c b/src/H5Fcompact.c
index 3a36edb..0a21211 100644
--- a/src/H5Fcompact.c
+++ b/src/H5Fcompact.c
@@ -44,9 +44,9 @@ static int              interface_initialize_g = 0;
  *-------------------------------------------------------------------------
  */
 herr_t
-H5F_compact_readv(H5F_t *f, const H5O_layout_t *layout, size_t nseq, 
+H5F_compact_readv(H5F_t UNUSED *f, const H5O_layout_t *layout, size_t nseq, 
                   size_t size_arr[], hsize_t offset_arr[], 
-                  hid_t dxpl_id, void *_buf/*out*/)
+                  hid_t UNUSED dxpl_id, void *_buf/*out*/)
 {
     unsigned char       *buf=(unsigned char *)_buf;
     size_t              size;
@@ -93,11 +93,11 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5F_compact_writev(H5F_t *f, H5O_layout_t *layout, size_t nseq,
+H5F_compact_writev(H5F_t UNUSED *f, H5O_layout_t *layout, size_t nseq,
                   size_t size_arr[], hsize_t offset_arr[], 
-                  hid_t dxpl_id, const void *_buf)
+                  hid_t UNUSED dxpl_id, const void *_buf)
 {
-    unsigned char       *buf=(unsigned char *)_buf;
+    const unsigned char       *buf=(const unsigned char *)_buf;
     size_t              size;
     haddr_t             offset;
     unsigned            u;
diff --git a/src/H5Fcontig.c b/src/H5Fcontig.c
index 89f9fc5..fce1ba9 100644
--- a/src/H5Fcontig.c
+++ b/src/H5Fcontig.c
@@ -14,11 +14,19 @@
 
 #define H5F_PACKAGE		/*suppress error about including H5Fpkg	  */
 
-#include "H5private.h"
-#include "H5Eprivate.h"
+#include "H5private.h"		/* Generic Functions			*/
+#include "H5Dprivate.h"		/* Dataset functions			*/
+#include "H5Eprivate.h"		/* Error handling		  	*/
 #include "H5Fpkg.h"
 #include "H5FDprivate.h"	/*file driver				  */
 #include "H5FLprivate.h"	/*Free Lists	  */
+#include "H5Oprivate.h"		/* Object headers		  	*/
+#include "H5Pprivate.h"		/* Property lists			*/
+#include "H5Vprivate.h"		/* Vector and array functions		*/
+
+/* MPIO & MPIPOSIX drivers needed for special checks */
+#include "H5FDmpio.h"
+#include "H5FDmpiposix.h"
 
 /* Interface initialization */
 #define PABLO_MASK	H5Fcontig_mask
@@ -28,6 +36,187 @@ static int		interface_initialize_g = 0;
 /* Declare a PQ free list to manage the sieve buffer information */
 H5FL_BLK_DEFINE(sieve_buf);
 
+/* Extern the free list to manage blocks of type conversion data */
+H5FL_BLK_EXTERN(type_conv);
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_contig_fill
+ *
+ * Purpose:	Write fill values to a contiguously stored dataset.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Quincey Koziol
+ *		August 22, 2002
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5F_contig_fill(H5F_t *f, hid_t dxpl_id, struct H5O_layout_t *layout,
+    struct H5P_genplist_t *dc_plist, const struct H5S_t *space,
+    size_t elmt_size)
+{
+    H5O_fill_t  fill;           /* Fill value information */
+    H5O_efl_t   efl;            /* External File List info */
+    hssize_t    snpoints;       /* Number of points in space (for error checking) */
+    size_t      npoints;        /* Number of points in space */
+    size_t      ptsperbuf;      /* Maximum # of points which fit in the buffer */
+    size_t	bufsize=64*1024; /* Size of buffer to write */
+    size_t	size;           /* Current # of points to write */
+    hsize_t	addr;           /* Offset in dataset */
+    void       *buf = NULL;     /* Buffer for fill value writing */
+#ifdef H5_HAVE_PARALLEL
+    MPI_Comm	mpi_comm=MPI_COMM_NULL;	/* MPI communicator for file */
+    int         mpi_rank=(-1);  /* This process's rank  */
+    int         mpi_size=(-1);  /* Total # of processes */
+    int         mpi_round=0;    /* Current process responsible for I/O */
+    int         mpi_code;       /* MPI return code */
+    unsigned    blocks_written=0; /* Flag to indicate that chunk was actually written */
+    unsigned    using_mpi=0;    /* Flag to indicate that the file is being accessed with an MPI-capable file driver */
+#endif /* H5_HAVE_PARALLEL */
+    herr_t	ret_value=SUCCEED;	/* Return value */
+    
+    FUNC_ENTER_NOAPI(H5F_contig_fill, FAIL);
+
+    /* Check args */
+    assert(f);
+    assert(TRUE==H5P_isa_class(dxpl_id,H5P_DATASET_XFER));
+    assert(layout && H5D_CONTIGUOUS==layout->type);
+    assert(layout->ndims>0 && layout->ndims<=H5O_LAYOUT_NDIMS);
+    assert(H5F_addr_defined(layout->addr));
+    assert(dc_plist!=NULL);
+    assert(space);
+    assert(elmt_size>0);
+
+    /* Get necessary properties from dataset creation property list */
+    if(H5P_get(dc_plist, H5D_CRT_FILL_VALUE_NAME, &fill) < 0)
+        HGOTO_ERROR(H5E_STORAGE, H5E_CANTGET, FAIL, "can't get fill value");
+    if(H5P_get(dc_plist, H5D_CRT_EXT_FILE_LIST_NAME, &efl) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_CANTGET, FAIL, "can't retrieve external file list");
+
+#ifdef H5_HAVE_PARALLEL
+    /* Retrieve up MPI parameters */
+    if(IS_H5FD_MPIO(f)) {
+        /* Get the MPI communicator */
+        if (MPI_COMM_NULL == (mpi_comm=H5FD_mpio_communicator(f->shared->lf)))
+            HGOTO_ERROR(H5E_INTERNAL, H5E_MPI, FAIL, "Can't retrieve MPI communicator");
+
+        /* Get the MPI rank & size */
+        if ((mpi_rank=H5FD_mpio_mpi_rank(f->shared->lf))<0)
+            HGOTO_ERROR(H5E_INTERNAL, H5E_MPI, FAIL, "Can't retrieve MPI rank");
+        if ((mpi_size=H5FD_mpio_mpi_size(f->shared->lf))<0)
+            HGOTO_ERROR(H5E_INTERNAL, H5E_MPI, FAIL, "Can't retrieve MPI size");
+
+        /* Set the MPI-capable file driver flag */
+        using_mpi=1;
+    } /* end if */
+    else {
+        if(IS_H5FD_MPIPOSIX(f)) {
+            /* Get the MPI communicator */
+            if (MPI_COMM_NULL == (mpi_comm=H5FD_mpiposix_communicator(f->shared->lf)))
+                HGOTO_ERROR(H5E_INTERNAL, H5E_MPI, FAIL, "Can't retrieve MPI communicator");
+
+            /* Get the MPI rank & size */
+            if ((mpi_rank=H5FD_mpiposix_mpi_rank(f->shared->lf))<0)
+                HGOTO_ERROR(H5E_INTERNAL, H5E_MPI, FAIL, "Can't retrieve MPI rank");
+            if ((mpi_size=H5FD_mpiposix_mpi_size(f->shared->lf))<0)
+                HGOTO_ERROR(H5E_INTERNAL, H5E_MPI, FAIL, "Can't retrieve MPI size");
+
+            /* Set the MPI-capable file driver flag */
+            using_mpi=1;
+        } /* end if */
+    } /* end else */
+#endif /* H5_HAVE_PARALLEL */
+
+    /* Get the number of elements in the dataset's dataspace */
+    snpoints = H5S_get_simple_extent_npoints(space);
+    assert(snpoints>=0);
+    H5_ASSIGN_OVERFLOW(npoints,snpoints,hssize_t,size_t);
+
+    /* Don't write default fill-values to external files */
+    if(efl.nused>0 && !fill.buf)
+        HGOTO_DONE(SUCCEED);
+
+    /* If fill value is library default, use the element size */
+    if(!fill.buf)
+        fill.size=elmt_size;
+
+    /*
+     * Fill the entire current extent with the fill value.  We can do
+     * this quite efficiently by making sure we copy the fill value
+     * in relatively large pieces.
+     */
+     ptsperbuf = MAX(1, bufsize/fill.size);
+     bufsize = ptsperbuf*fill.size;
+
+     /* Allocate temporary buffer */
+     if ((buf=H5FL_BLK_ALLOC(type_conv,bufsize,0))==NULL)
+         HGOTO_ERROR (H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for fill buffer");
+
+     /* Fill the buffer with the user's fill value */
+     if(fill.buf)
+        H5V_array_fill(buf, fill.buf, fill.size, ptsperbuf);
+     else /* Fill the buffer with the default fill value */
+        HDmemset(buf,0,bufsize);
+     
+     /* Start at the beginning of the dataset */
+     addr = 0;
+
+     /* Loop through writing the fill value to the dataset */
+     while (npoints>0) {
+          size = MIN(ptsperbuf, npoints) * fill.size;
+
+#ifdef H5_HAVE_PARALLEL
+            /* Check if this file is accessed with an MPI-capable file driver */
+            if(using_mpi) {
+                /* Round-robin write the chunks out from only one process */
+                if(mpi_round==mpi_rank) {
+                    if (H5F_seq_write(f, dxpl_id, layout, dc_plist, space,
+                            fill.size, size, addr, buf)<0)
+                        HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to write fill value to dataset");
+                } /* end if */
+                mpi_round=(++mpi_round)%mpi_size;
+
+                /* Indicate that blocks are being written */
+                blocks_written=1;
+            } /* end if */
+            else {
+#endif /* H5_HAVE_PARALLEL */
+                if (H5F_seq_write(f, dxpl_id, layout, dc_plist, space,
+                        fill.size, size, addr, buf)<0)
+                    HGOTO_ERROR(H5E_DATASET, H5E_CANTINIT, FAIL, "unable to write fill value to dataset");
+#ifdef H5_HAVE_PARALLEL
+            } /* end else */
+#endif /* H5_HAVE_PARALLEL */
+
+          npoints -= MIN(ptsperbuf, npoints);
+          addr += size;
+      } /* end while */
+            
+#ifdef H5_HAVE_PARALLEL
+    /* Only need to block at the barrier if we actually wrote fill values */
+    /* And if we are using an MPI-capable file driver */
+    if(using_mpi && blocks_written) {
+        /* Wait at barrier to avoid race conditions where some processes are
+         * still writing out fill values and other processes race ahead to data
+         * in, getting bogus data.
+         */
+        if (MPI_SUCCESS != (mpi_code=MPI_Barrier(mpi_comm)))
+            HMPI_GOTO_ERROR(FAIL, "MPI_Barrier failed", mpi_code);
+    } /* end if */
+#endif /* H5_HAVE_PARALLEL */
+
+done:
+    /* Free the buffer for fill values */
+    if (buf)
+        H5FL_BLK_FREE(type_conv,buf);
+
+    FUNC_LEAVE(ret_value);
+}
+
 
 /*-------------------------------------------------------------------------
  * Function:	H5F_contig_read
diff --git a/src/H5Fistore.c b/src/H5Fistore.c
index 0bba74e..f36b6200 100644
--- a/src/H5Fistore.c
+++ b/src/H5Fistore.c
@@ -1758,7 +1758,6 @@ H5F_istore_read(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
         if ((chunk_size>f->shared->rdcc_nbytes && pline.nfilters==0 &&
                 chunk_addr!=HADDR_UNDEF)
 
-#ifdef H5_HAVE_PARALLEL
         /*
          * If MPIO or MPIPOSIX is used and file can be written to, we must bypass the
          * chunk-cache scheme because other MPI processes could be writing to
@@ -1766,7 +1765,6 @@ H5F_istore_read(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
          * Do a direct write-through of only the elements requested.
          */
             || ((IS_H5FD_MPIO(f) ||IS_H5FD_MPIPOSIX(f)) && (H5F_ACC_RDWR & f->shared->flags))
-#endif /* H5_HAVE_PARALLEL */
             ) {
             H5O_layout_t	l;	/* temporary layout */
 
@@ -1942,14 +1940,12 @@ H5F_istore_write(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
         if ((chunk_size>f->shared->rdcc_nbytes && pline.nfilters==0 &&
                 chunk_addr!=HADDR_UNDEF)
 
-#ifdef H5_HAVE_PARALLEL
         /*
          * If MPIO or MPIPOSIX is used, must bypass the chunk-cache scheme because other
          * MPI processes could be writing to other elements in the same chunk.
          * Do a direct write-through of only the elements requested.
          */
             || ((IS_H5FD_MPIO(f) ||IS_H5FD_MPIPOSIX(f)) && (H5F_ACC_RDWR & f->shared->flags))
-#endif /* H5_HAVE_PARALLEL */
             ) {
             H5O_layout_t	l;	/* temporary layout */
 
@@ -2334,6 +2330,7 @@ H5F_istore_allocate(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
     H5P_genplist_t *dx_plist;   /* Data xfer property list */
     double	split_ratios[3];/* B-tree node splitting ratios		*/
 #ifdef H5_HAVE_PARALLEL
+    MPI_Comm	mpi_comm=MPI_COMM_NULL;	/* MPI communicator for file */
     int         mpi_rank=(-1);  /* This process's rank  */
     int         mpi_size=(-1);  /* Total # of processes */
     int         mpi_round=0;    /* Current process responsible for I/O */
@@ -2342,6 +2339,7 @@ H5F_istore_allocate(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
     unsigned    using_mpi=0;    /* Flag to indicate that the file is being accessed with an MPI-capable file driver */
 #endif /* H5_HAVE_PARALLEL */
     int		carry;          /* Flag to indicate that chunk increment carrys to higher dimension (sorta) */
+    unsigned	chunk_exists;   /* Flag to indicate whether a chunk exists already */
     int		i;              /* Local index variable */
     unsigned	u;              /* Local index variable */
     herr_t	ret_value=SUCCEED;	/* Return value */
@@ -2374,6 +2372,11 @@ H5F_istore_allocate(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
 #ifdef H5_HAVE_PARALLEL
     /* Retrieve up MPI parameters */
     if(IS_H5FD_MPIO(f)) {
+        /* Get the MPI communicator */
+        if (MPI_COMM_NULL == (mpi_comm=H5FD_mpio_communicator(f->shared->lf)))
+            HGOTO_ERROR(H5E_INTERNAL, H5E_MPI, FAIL, "Can't retrieve MPI communicator");
+
+        /* Get the MPI rank & size */
         if ((mpi_rank=H5FD_mpio_mpi_rank(f->shared->lf))<0)
             HGOTO_ERROR(H5E_INTERNAL, H5E_MPI, FAIL, "Can't retrieve MPI rank");
         if ((mpi_size=H5FD_mpio_mpi_size(f->shared->lf))<0)
@@ -2384,6 +2387,10 @@ H5F_istore_allocate(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
     } /* end if */
     else {
         if(IS_H5FD_MPIPOSIX(f)) {
+            /* Get the MPI communicator */
+            if (MPI_COMM_NULL == (mpi_comm=H5FD_mpiposix_communicator(f->shared->lf)))
+                HGOTO_ERROR(H5E_INTERNAL, H5E_MPI, FAIL, "Can't retrieve MPI communicator");
+
             /* Get the MPI rank & size */
             if ((mpi_rank=H5FD_mpiposix_mpi_rank(f->shared->lf))<0)
                 HGOTO_ERROR(H5E_INTERNAL, H5E_MPI, FAIL, "Can't retrieve MPI rank");
@@ -2396,12 +2403,6 @@ H5F_istore_allocate(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
     } /* end else */
 #endif /* H5_HAVE_PARALLEL */
 
-#ifdef H5_HAVE_PARALLEL
-    /* Can't use data I/O pipeline in parallel (yet) */
-    if (using_mpi && pline.nfilters>0)
-        HGOTO_ERROR(H5E_STORAGE, H5E_UNSUPPORTED, FAIL, "can't use data pipeline in parallel");
-#endif /* H5_HAVE_PARALLEL */
-
     /*
      * Setup indice to go through all chunks. (Future improvement
      * should allocate only chunks that have no file space assigned yet.
@@ -2450,8 +2451,32 @@ H5F_istore_allocate(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
     /* Loop over all chunks */
     carry=0;
     while (carry==0) {
-        /* Check if the chunk exists yet */
+        /* Check if the chunk exists yet on disk */
+        chunk_exists=1;
         if(H5F_istore_get_addr(f,layout,chunk_offset)==HADDR_UNDEF) {
+            H5F_rdcc_t             *rdcc = &(f->shared->rdcc);	/*raw data chunk cache */
+            H5F_rdcc_ent_t         *ent = NULL;              	/*cache entry  */
+
+            /* Didn't find the chunk on disk */
+            chunk_exists = 0;
+
+            /* Look for chunk in cache */
+            for(ent = rdcc->head; ent && !chunk_exists; ent = ent->next) {
+                /* Make certain we are dealing with the correct B-tree, etc */
+                if (layout->ndims==ent->layout->ndims &&
+                        H5F_addr_eq(layout->addr, ent->layout->addr)) {
+
+                    /* Assume a match */
+                    chunk_exists = 1;
+                    for(u = 0; u < layout->ndims && chunk_exists; u++) {
+                        if(ent->offset[u] != chunk_offset[u])
+                            chunk_exists = 0;       /* Reset if no match */
+                    } /* end for */
+                } /* end if */
+            } /* end for */
+        } /* end if */
+
+        if(!chunk_exists) {
             /* Initialize the chunk information */
             udata.mesg = *layout;
             udata.key.filter_mask = 0;
@@ -2507,17 +2532,8 @@ H5F_istore_allocate(H5F_t *f, hid_t dxpl_id, const H5O_layout_t *layout,
          * still writing out chunks and other processes race ahead to read
          * them in, getting bogus data.
          */
-        if(IS_H5FD_MPIO(f)) {
-            if (MPI_SUCCESS != (mpi_code=MPI_Barrier(H5FD_mpio_communicator(f->shared->lf))))
-                HMPI_GOTO_ERROR(FAIL, "MPI_Barrier failed", mpi_code);
-        } /* end if */
-        else {
-            /* Sanity Check */
-            assert(IS_H5FD_MPIPOSIX(f));
-
-            if (MPI_SUCCESS!=(mpi_code=MPI_Barrier(H5FD_mpiposix_communicator(f->shared->lf))))
-                HMPI_GOTO_ERROR(FAIL, "MPI_Barrier failed", mpi_code);
-        } /* end else */
+        if (MPI_SUCCESS != (mpi_code=MPI_Barrier(mpi_comm)))
+            HMPI_GOTO_ERROR(FAIL, "MPI_Barrier failed", mpi_code);
     } /* end if */
 #endif /* H5_HAVE_PARALLEL */
 
@@ -2662,13 +2678,17 @@ H5F_istore_prune_by_extent(H5F_t *f, const H5O_layout_t *layout, const H5S_t * s
     for(ent = rdcc->head; ent; ent = next) {
 	next = ent->next;
 
-	found = 0;
-	for(u = 0; u < ent->layout->ndims - 1; u++) {
-	    if((hsize_t)ent->offset[u] > curr_dims[u]) {
-		found = 1;
-		break;
-	    }
-	}
+        /* Make certain we are dealing with the correct B-tree, etc */
+        if (layout->ndims==ent->layout->ndims &&
+                H5F_addr_eq(layout->addr, ent->layout->addr)) {
+            found = 0;
+            for(u = 0; u < ent->layout->ndims - 1; u++) {
+                if((hsize_t)ent->offset[u] > curr_dims[u]) {
+                    found = 1;
+                    break;
+                }
+            }
+        } /* end if */
 
 	if(found) {
 #if defined (H5F_ISTORE_DEBUG)
diff --git a/src/H5Fpkg.h b/src/H5Fpkg.h
index 92e6a5b..fb2c58d 100644
--- a/src/H5Fpkg.h
+++ b/src/H5Fpkg.h
@@ -183,8 +183,6 @@ __DLL__ herr_t H5F_istore_init (H5F_t *f);
 __DLL__ herr_t H5F_istore_flush (H5F_t *f, hbool_t preempt);
 __DLL__ herr_t H5F_istore_dest (H5F_t *f);
 __DLL__ herr_t H5F_istore_stats (H5F_t *f, hbool_t headers);
-__DLL__ herr_t H5F_istore_create(H5F_t *f,
-				 struct H5O_layout_t *layout/*in,out*/);
 __DLL__ herr_t H5F_istore_read(H5F_t *f, hid_t dxpl_id,
                                 const struct H5O_layout_t *layout,
                                 struct H5P_genplist_t *dc_plist,
diff --git a/src/H5Fprivate.h b/src/H5Fprivate.h
index 15ef548..b3a48f3 100644
--- a/src/H5Fprivate.h
+++ b/src/H5Fprivate.h
@@ -345,8 +345,6 @@ __DLL__ herr_t H5F_get_obj_count(H5F_t *f, unsigned types,
 __DLL__ herr_t H5F_get_obj_ids(H5F_t *f, unsigned types, hid_t *obj_id_list);
 
 /* Functions that operate on array storage */
-__DLL__ herr_t H5F_arr_create(H5F_t *f,
-			      struct H5O_layout_t *layout /*in,out*/);
 __DLL__ herr_t H5F_arr_read (H5F_t *f, hid_t dxpl_id,
                             const struct H5O_layout_t *layout,
                             struct H5P_genplist_t *dc_plist,
@@ -393,7 +391,14 @@ __DLL__ herr_t H5F_seq_writev(H5F_t *f, hid_t dxpl_id,
         size_t seq_len[], hsize_t file_offset[], const void *_buf);
 
 
+/* Functions that operate on contiguous storage */
+__DLL__ herr_t H5F_contig_fill(H5F_t *f, hid_t dxpl_id,
+        struct H5O_layout_t *layout, struct H5P_genplist_t *dc_plist,
+        const struct H5S_t *space, size_t elmt_size);
+
 /* Functions that operate on indexed storage */
+__DLL__ herr_t H5F_istore_create(H5F_t *f,
+				 struct H5O_layout_t *layout/*in,out*/);
 __DLL__ herr_t H5F_istore_allocate (H5F_t *f, hid_t dxpl_id,
                                 const struct H5O_layout_t *layout,
                                 const hsize_t *space_dim,
diff --git a/src/H5Oefl.c b/src/H5Oefl.c
index eacdeb3..388aa4a 100644
--- a/src/H5Oefl.c
+++ b/src/H5Oefl.c
@@ -532,7 +532,7 @@ H5O_efl_write (H5F_t UNUSED *f, const H5O_efl_t *efl, haddr_t addr,
 	    HGOTO_ERROR (H5E_EFL, H5E_OVERFLOW, FAIL, "write past logical end of file");
 	if (H5F_OVERFLOW_HSIZET2OFFT (efl->slot[i].offset+skip))
 	    HGOTO_ERROR (H5E_EFL, H5E_OVERFLOW, FAIL, "external file address overflowed");
-	if ((fd=HDopen (efl->slot[i].name, O_RDWR, 0))<0) {
+	if ((fd=HDopen (efl->slot[i].name, O_CREAT|O_RDWR, 0666))<0) {
 	    if (HDaccess (efl->slot[i].name, F_OK)<0) {
 		HGOTO_ERROR (H5E_EFL, H5E_CANTOPENFILE, FAIL, "external raw data file does not exist");
 	    } else {
diff --git a/src/H5Olayout.c b/src/H5Olayout.c
index 65f4cdb..33797c6 100644
--- a/src/H5Olayout.c
+++ b/src/H5Olayout.c
@@ -211,7 +211,6 @@ H5O_layout_encode(H5F_t *f, uint8_t *p, const void *_mesg)
     if(mesg->type==H5D_COMPACT) {
         UINT32ENCODE(p, mesg->size);
         if(mesg->size>0 && mesg->buf) {
-            H5_CHECK_OVERFLOW(mesg->size,ssize_t,size_t);
             HDmemcpy(p, mesg->buf, mesg->size);
             p += mesg->size;
         }
diff --git a/src/H5S.c b/src/H5S.c
index 34eb4ea..6424ada 100644
--- a/src/H5S.c
+++ b/src/H5S.c
@@ -1899,11 +1899,11 @@ done:
  *
  *-------------------------------------------------------------------------
  */
-herr_t
+int
 H5S_set_extent( H5S_t *space, const hsize_t *size )
 {
     unsigned u;
-    herr_t ret_value=SUCCEED;
+    herr_t ret_value=0;
        
     FUNC_ENTER_NOAPI( H5S_set_extent, FAIL );
 
@@ -1911,19 +1911,21 @@ H5S_set_extent( H5S_t *space, const hsize_t *size )
     assert( space && H5S_SIMPLE==space->extent.type );
     assert( size);
 
-    /* Check for changing dimensions of a scalar dataspace */
-    if(space->extent.u.simple.rank==0)
-
     /* Verify that the dimensions being changed are allowed to change */
-    for ( u = 0; u < space->extent.u.simple.rank; u++ )
+    for ( u = 0; u < space->extent.u.simple.rank; u++ ) {
         if ( space->extent.u.simple.max &&
                  H5S_UNLIMITED != space->extent.u.simple.max[u] &&
-                 space->extent.u.simple.max[u]<size[u] )
+                 space->extent.u.simple.max[u]!=size[u] )
              HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL,"dimension cannot be modified");
+        ret_value++;
+    } /* end for */
 
-    /* Update dimensions with new values */
-    for ( u = 0; u < space->extent.u.simple.rank; u++ )
-        space->extent.u.simple.size[u] = size[u];
+    /* Update */
+    if (ret_value) {
+        /* Update dimensions with new values */
+        for ( u = 0; u < space->extent.u.simple.rank; u++ )
+            space->extent.u.simple.size[u] = size[u];
+    } /* end if */
 
 done:
     FUNC_LEAVE( ret_value );
diff --git a/src/H5Smpio.c b/src/H5Smpio.c
index 61297bb..125c946 100644
--- a/src/H5Smpio.c
+++ b/src/H5Smpio.c
@@ -915,7 +915,7 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5S_mpio_spaces_write(H5F_t *f, const H5O_layout_t *layout,
+H5S_mpio_spaces_write(H5F_t *f, H5O_layout_t *layout,
                     H5P_genplist_t UNUSED *dc_plist, size_t elmt_size,
 		    const H5S_t *file_space, const H5S_t *mem_space,
 		    hid_t dxpl_id, const void *buf)
diff --git a/src/H5Sprivate.h b/src/H5Sprivate.h
index 393f6bb..083847e 100644
--- a/src/H5Sprivate.h
+++ b/src/H5Sprivate.h
@@ -109,7 +109,7 @@ typedef struct H5S_conv_t {
 
 
     /* Write directly from app buffer to file */
-    herr_t (*write)(H5F_t *f, const struct H5O_layout_t *layout,
+    herr_t (*write)(H5F_t *f, struct H5O_layout_t *layout,
                    H5P_genplist_t *dc_plist, size_t elmt_size,
 		   const H5S_t *file_space, const H5S_t *mem_space,
 		   hid_t dxpl_id, const void *buf);
@@ -156,7 +156,7 @@ __DLL__ int H5S_cmp(const H5S_t *ds1, const H5S_t *ds2);
 __DLL__ htri_t H5S_is_simple(const H5S_t *sdim);
 __DLL__ herr_t H5S_extent_release(H5S_t *space);
 __DLL__ int H5S_extend(H5S_t *space, const hsize_t *size);
-__DLL__ herr_t H5S_set_extent(H5S_t *space, const hsize_t *size);
+__DLL__ int H5S_set_extent(H5S_t *space, const hsize_t *size);
 __DLL__ herr_t H5S_debug(H5F_t *f, const void *_mesg, FILE *stream,
 			 int indent, int fwidth);
 
@@ -168,7 +168,7 @@ __DLL__ herr_t H5S_select_iterate(void *buf, hid_t type_id, H5S_t *space,
 				H5D_operator_t op, void *operator_data);
 __DLL__ herr_t H5S_select_fill(void *fill, size_t fill_size,
                                 const H5S_t *space, void *buf);
-__DLL__ herr_t H5S_select_fscat (H5F_t *f, const struct H5O_layout_t *layout,
+__DLL__ herr_t H5S_select_fscat (H5F_t *f, struct H5O_layout_t *layout,
         H5P_genplist_t *dc_plist, size_t elmt_size, const H5S_t *file_space,
         H5S_sel_iter_t *file_iter, hsize_t nelmts, hid_t dxpl_id,
         const void *_buf);
@@ -185,7 +185,7 @@ __DLL__ hsize_t H5S_select_mgath (const void *_buf, size_t elmt_size,
 __DLL__ herr_t H5S_select_read(H5F_t *f, const struct H5O_layout_t *layout,
         H5P_genplist_t *dc_plist, size_t elmt_size, const H5S_t *file_space,
         const H5S_t *mem_space, hid_t dxpl_id, void *buf/*out*/);
-__DLL__ herr_t H5S_select_write(H5F_t *f, const struct H5O_layout_t *layout,
+__DLL__ herr_t H5S_select_write(H5F_t *f, struct H5O_layout_t *layout,
         H5P_genplist_t *dc_plist, size_t elmt_size, const H5S_t *file_space,
         const H5S_t *mem_space, hid_t dxpl_id, const void *buf/*out*/);
 
@@ -206,7 +206,7 @@ __DLL__ herr_t H5S_mpio_spaces_read(H5F_t *f,
 
 /* MPI-IO function to write directly from app buffer to file rky980813 */
 __DLL__ herr_t H5S_mpio_spaces_write(H5F_t *f,
-				    const struct H5O_layout_t *layout,
+				    struct H5O_layout_t *layout,
                                     H5P_genplist_t *dc_plist,
 				    size_t elmt_size, const H5S_t *file_space,
 				    const H5S_t *mem_space, hid_t dxpl_id,
diff --git a/src/H5Sselect.c b/src/H5Sselect.c
index 10ece00..70888e8 100644
--- a/src/H5Sselect.c
+++ b/src/H5Sselect.c
@@ -777,7 +777,7 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5S_select_fscat (H5F_t *f, const struct H5O_layout_t *layout,
+H5S_select_fscat (H5F_t *f, struct H5O_layout_t *layout,
                  H5P_genplist_t *dc_plist, size_t elmt_size,
 		 const H5S_t *space, H5S_sel_iter_t *iter,
 		 hsize_t nelmts, hid_t dxpl_id, const void *_buf)
@@ -1365,7 +1365,7 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5S_select_write(H5F_t *f, const H5O_layout_t *layout, H5P_genplist_t *dc_plist,
+H5S_select_write(H5F_t *f, H5O_layout_t *layout, H5P_genplist_t *dc_plist,
             size_t elmt_size, const H5S_t *file_space,
 	    const H5S_t *mem_space, hid_t dxpl_id, const void *_buf/*out*/)
 {