[svn-r22228] Description:

	Bring r22219 from trunk to 1.8 branch: (with release manager's blessing)

      Merge "file image" changes from feature branch back to trunk.

Tested on:
   h5committested

26 files changed, 1230 insertions, 271 deletions

diff --git a/src/H5Dint.c b/src/H5Dint.c
index 98d3447..0fb31a4 100644
--- a/src/H5Dint.c
+++ b/src/H5Dint.c
@@ -2438,7 +2438,8 @@ H5D_flush(const H5F_t *f, hid_t dxpl_id)
     udata.dxpl_id = dxpl_id;
 
     /* Iterate over all the open datasets */
-    H5I_search(H5I_DATASET, H5D_flush_cb, &udata, FALSE);
+    if(H5I_iterate(H5I_DATASET, H5D_flush_cb, &udata, FALSE) < 0)
+        HGOTO_ERROR(H5E_DATASET, H5E_BADITER, FAIL, "unable to flush cached dataset info")
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
diff --git a/src/H5E.c b/src/H5E.c
index 4c4433e..5baf7a5 100644
--- a/src/H5E.c
+++ b/src/H5E.c
@@ -107,7 +107,7 @@ static H5E_cls_t *H5E_register_class(const char *cls_name, const char *lib_name,
                                 const char *version);
 static herr_t  H5E_unregister_class(H5E_cls_t *cls);
 static ssize_t H5E_get_class_name(const H5E_cls_t *cls, char *name, size_t size);
-static int H5E_close_msg_cb(void *obj_ptr, hid_t obj_id, void *key);
+static int H5E_close_msg_cb(void *obj_ptr, hid_t obj_id, void *udata);
 static herr_t  H5E_close_msg(H5E_msg_t *err);
 static H5E_msg_t *H5E_create_msg(H5E_cls_t *cls, H5E_type_t msg_type, const char *msg);
 static H5E_t  *H5E_get_current_stack(void);
@@ -543,8 +543,8 @@ H5E_unregister_class(H5E_cls_t *cls)
     HDassert(cls);
 
     /* Iterate over all the messages and delete those in this error class */
-    /* (Ignore return value, since callback isn't designed to return a particular object) */
-    (void)H5I_search(H5I_ERROR_MSG, H5E_close_msg_cb, cls, FALSE);
+    if(H5I_iterate(H5I_ERROR_MSG, H5E_close_msg_cb, cls, FALSE) < 0)
+        HGOTO_ERROR(H5E_ERROR, H5E_BADITER, FAIL, "unable to free all messages in this error class")
 
     /* Free error class structure */
     if(H5E_free_class(cls) < 0)
@@ -631,7 +631,7 @@ H5E_get_class_name(const H5E_cls_t *cls, char *name, size_t size)
 /*-------------------------------------------------------------------------
  * Function:    H5E_close_msg_cb
  *
- * Purpose:     H5I_search callback function to close error messages in the
+ * Purpose:     H5I_iterate callback function to close error messages in the
  *              error class.
  *
  * Return:	Non-negative value on success/Negative on failure
@@ -642,10 +642,10 @@ H5E_get_class_name(const H5E_cls_t *cls, char *name, size_t size)
  *-------------------------------------------------------------------------
  */
 static int
-H5E_close_msg_cb(void *obj_ptr, hid_t obj_id, void *key)
+H5E_close_msg_cb(void *obj_ptr, hid_t obj_id, void *udata)
 {
     H5E_msg_t   *err_msg = (H5E_msg_t*)obj_ptr;
-    H5E_cls_t   *cls = (H5E_cls_t*)key;
+    H5E_cls_t   *cls = (H5E_cls_t*)udata;
     herr_t      ret_value = SUCCEED;       /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
diff --git a/src/H5Edefin.h b/src/H5Edefin.h
index 9ca9371..b6bde20 100644
--- a/src/H5Edefin.h
+++ b/src/H5Edefin.h
@@ -91,6 +91,7 @@ hid_t H5E_CANTRELEASE_g    = FAIL;      /* Unable to release object */
 hid_t H5E_CANTGET_g        = FAIL;      /* Can't get value */
 hid_t H5E_CANTSET_g        = FAIL;      /* Can't set value */
 hid_t H5E_DUPCLASS_g       = FAIL;      /* Duplicate class name in parent class */
+hid_t H5E_SETDISALLOWED_g  = FAIL;      /* Disallowed operation */
 
 /* Free space errors */
 hid_t H5E_CANTMERGE_g      = FAIL;      /* Can't merge objects */
diff --git a/src/H5Einit.h b/src/H5Einit.h
index 36b17a0..34fac7b 100644
--- a/src/H5Einit.h
+++ b/src/H5Einit.h
@@ -329,6 +329,11 @@ if((msg = H5E_create_msg(cls, H5E_MINOR, "Duplicate class name in parent class")
     HGOTO_ERROR(H5E_ERROR, H5E_CANTINIT, FAIL, "error message initialization failed")
 if((H5E_DUPCLASS_g = H5I_register(H5I_ERROR_MSG, msg, FALSE))<0)
     HGOTO_ERROR(H5E_ERROR, H5E_CANTREGISTER, FAIL, "can't register error message")
+assert(H5E_SETDISALLOWED_g==(-1));
+if((msg = H5E_create_msg(cls, H5E_MINOR, "Disallowed operation"))==NULL)
+    HGOTO_ERROR(H5E_ERROR, H5E_CANTINIT, FAIL, "error message initialization failed")
+if((H5E_SETDISALLOWED_g = H5I_register(H5I_ERROR_MSG, msg, FALSE))<0)
+    HGOTO_ERROR(H5E_ERROR, H5E_CANTREGISTER, FAIL, "can't register error message")
 
 /* Free space errors */
 assert(H5E_CANTMERGE_g==(-1));
diff --git a/src/H5Epubgen.h b/src/H5Epubgen.h
index 68fd177..1540b07 100644
--- a/src/H5Epubgen.h
+++ b/src/H5Epubgen.h
@@ -151,9 +151,11 @@ H5_DLLVAR hid_t H5E_CANTRELEASE_g;   /* Unable to release object */
 #define H5E_CANTGET          (H5OPEN H5E_CANTGET_g)
 #define H5E_CANTSET          (H5OPEN H5E_CANTSET_g)
 #define H5E_DUPCLASS         (H5OPEN H5E_DUPCLASS_g)
+#define H5E_SETDISALLOWED    (H5OPEN H5E_SETDISALLOWED_g)
 H5_DLLVAR hid_t H5E_CANTGET_g;       /* Can't get value */
 H5_DLLVAR hid_t H5E_CANTSET_g;       /* Can't set value */
 H5_DLLVAR hid_t H5E_DUPCLASS_g;      /* Duplicate class name in parent class */
+H5_DLLVAR hid_t H5E_SETDISALLOWED_g; /* Disallowed operation */
 
 /* Free space errors */
 #define H5E_CANTMERGE        (H5OPEN H5E_CANTMERGE_g)
diff --git a/src/H5Eterm.h b/src/H5Eterm.h
index 85eb19e..10a6014 100644
--- a/src/H5Eterm.h
+++ b/src/H5Eterm.h
@@ -92,7 +92,8 @@ H5E_CANTRELEASE_g=
 /* Property list errors */    
 H5E_CANTGET_g=    
 H5E_CANTSET_g=    
-H5E_DUPCLASS_g=
+H5E_DUPCLASS_g=    
+H5E_SETDISALLOWED_g=
 
 /* Free space errors */    
 H5E_CANTMERGE_g=    
diff --git a/src/H5F.c b/src/H5F.c
index a74570a..79a3c41 100644
--- a/src/H5F.c
+++ b/src/H5F.c
@@ -65,7 +65,7 @@ typedef struct H5F_olist_t {
 } H5F_olist_t;
 
 /* PRIVATE PROTOTYPES */
-static size_t H5F_get_objects(const H5F_t *f, unsigned types, size_t max_objs, hid_t *obj_id_list, hbool_t app_ref);
+static herr_t H5F_get_objects(const H5F_t *f, unsigned types, size_t max_index, hid_t *obj_id_list, hbool_t app_ref, size_t *obj_id_count_ptr);
 static int H5F_get_objects_cb(void *obj_ptr, hid_t obj_id, void *key);
 static H5F_t *H5F_new(H5F_file_t *shared, hid_t fcpl_id, hid_t fapl_id,
                       H5FD_t *lf);
@@ -376,11 +376,6 @@ done:
  *
  * Programmer:	Raymond Lu
  *		Wednesday, Dec 5, 2001
- * Modification:
- *              Raymond Lu
- *              24 September 2008
- *              Changed the return value to ssize_t to  accommadate
- *              potential large number of objects.
  *
  *-------------------------------------------------------------------------
  */
@@ -388,18 +383,24 @@ ssize_t
 H5Fget_obj_count(hid_t file_id, unsigned types)
 {
     H5F_t    *f = NULL;         /* File to query */
-    ssize_t  ret_value;            /* Return value */
+    size_t  obj_count = 0;      /* Number of opened objects */
+    ssize_t  ret_value;         /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE2("Zs", "iIu", file_id, types);
 
+    /* Check arguments */
     if(file_id != (hid_t)H5F_OBJ_ALL && (NULL == (f = (H5F_t *)H5I_object_verify(file_id, H5I_FILE))))
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "not a file id")
     if(0 == (types & H5F_OBJ_ALL))
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "not an object type")
 
-    /* H5F_get_obj_count doesn't fail */
-    ret_value = (ssize_t)H5F_get_obj_count(f, types, TRUE);
+    /* Perform the query */
+    if(H5F_get_obj_count(f, types, TRUE, &obj_count) < 0)
+	HGOTO_ERROR(H5E_INTERNAL, H5E_BADITER, FAIL, "H5F_get_obj_count failed")
+
+    /* Set the return value */
+    ret_value = (ssize_t)obj_count;
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -412,31 +413,30 @@ done:
  * Purpose:	Private function return the number of opened object IDs
  *		(files, datasets, groups, datatypes) in the same file.
  *
- * Return:      Non-negative on success; can't fail.
+ * Return:      SUCCEED on success, FAIL on failure.
  *
  * Programmer:  Raymond Lu
  *              Wednesday, Dec 5, 2001
  *
- * Modification:
- *              Raymond Lu
- *              24 September 2008
- *              Changed the return value to size_t to accommadate
- *              potential large number of objects.
- *
  *-------------------------------------------------------------------------
  */
-size_t
-H5F_get_obj_count(const H5F_t *f, unsigned types, hbool_t app_ref)
+herr_t
+H5F_get_obj_count(const H5F_t *f, unsigned types, hbool_t app_ref, size_t *obj_id_count_ptr)
 {
-    size_t   ret_value;            /* Return value */
+    herr_t   ret_value = SUCCEED;
 
-    FUNC_ENTER_NOAPI_NOINIT_NOERR
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity check */
+    HDassert(obj_id_count_ptr);
 
-    /* H5F_get_objects doesn't fail */
-    ret_value = H5F_get_objects(f, types, 0, NULL, app_ref);
+    /* Perform the query */
+    if((ret_value = H5F_get_objects(f, types, 0, NULL, app_ref, obj_id_count_ptr)) < 0)
+        HGOTO_ERROR(H5E_INTERNAL, H5E_BADITER, FAIL, "H5F_get_objects failed")
 
+done:
     FUNC_LEAVE_NOAPI(ret_value)
-}
+} /* end H5F_get_obj_count() */
 
 
 /*-------------------------------------------------------------------------
@@ -461,19 +461,25 @@ ssize_t
 H5Fget_obj_ids(hid_t file_id, unsigned types, size_t max_objs, hid_t *oid_list)
 {
     H5F_t    *f = NULL;         /* File to query */
-    ssize_t   ret_value;         /* Return value */
+    size_t    obj_id_count = 0; /* Number of open objects */
+    ssize_t   ret_value;        /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE4("Zs", "iIuz*i", file_id, types, max_objs, oid_list);
 
+    /* Check arguments */
     if(file_id != (hid_t)H5F_OBJ_ALL && (NULL == (f = (H5F_t *)H5I_object_verify(file_id, H5I_FILE))))
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "not a file id")
     if(0 == (types & H5F_OBJ_ALL))
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "not an object type")
     HDassert(oid_list);
 
-    /* H5F_get_objects doesn't fail */
-    ret_value = (ssize_t)H5F_get_obj_ids(f, types, max_objs, oid_list, TRUE);
+    /* Perform the query */
+    if(H5F_get_obj_ids(f, types, max_objs, oid_list, TRUE, &obj_id_count) < 0)
+        HGOTO_ERROR(H5E_INTERNAL, H5E_BADITER, FAIL, "H5F_get_obj_ids failed")
+
+    /* Set the return value */
+    ret_value = (ssize_t)obj_id_count;
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -490,26 +496,25 @@ done:
  * Programmer:  Raymond Lu
  *              Wednesday, Dec 5, 2001
  *
- * Modification:
- *              Raymond Lu
- *              24 September 2008
- *              Changed the return value and MAX_OBJTS to size_t to accommadate
- *              potential large number of objects.
- *
  *-------------------------------------------------------------------------
  */
-size_t
-H5F_get_obj_ids(const H5F_t *f, unsigned types, size_t max_objs, hid_t *oid_list, hbool_t app_ref)
+herr_t
+H5F_get_obj_ids(const H5F_t *f, unsigned types, size_t max_objs, hid_t *oid_list, hbool_t app_ref, size_t *obj_id_count_ptr)
 {
-    size_t ret_value;              /* Return value */
+    herr_t ret_value = SUCCEED;              /* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT_NOERR
+    FUNC_ENTER_NOAPI(FAIL)
+
+    /* Sanity check */
+    HDassert(obj_id_count_ptr);
 
-    /* H5F_get_objects doesn't fail */
-    ret_value = H5F_get_objects(f, types, max_objs, oid_list, app_ref);
+    /* Perform the query */
+    if((ret_value = H5F_get_objects(f, types, max_objs, oid_list, app_ref, obj_id_count_ptr)) < 0)
+        HGOTO_ERROR(H5E_INTERNAL, H5E_BADITER, FAIL, "H5F_get_objects failed")
 
+done:
     FUNC_LEAVE_NOAPI(ret_value)
-}
+} /* end H5F_get_obj_ids() */
 
 
 /*---------------------------------------------------------------------------
@@ -525,14 +530,18 @@ H5F_get_obj_ids(const H5F_t *f, unsigned types, size_t max_objs, hid_t *oid_list
  *
  *---------------------------------------------------------------------------
  */
-static size_t
-H5F_get_objects(const H5F_t *f, unsigned types, size_t max_index, hid_t *obj_id_list, hbool_t app_ref)
+static herr_t
+H5F_get_objects(const H5F_t *f, unsigned types, size_t max_index, hid_t *obj_id_list, hbool_t app_ref, size_t *obj_id_count_ptr)
 {
     size_t obj_id_count=0;      /* Number of open IDs */
     H5F_olist_t olist;          /* Structure to hold search results */
-    size_t ret_value;          /* Return value */
+    htri_t type_exists;         /* Whether objects of a type are open */
+    herr_t ret_value = SUCCEED; /* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT_NOERR
+    FUNC_ENTER_NOAPI_NOINIT
+
+    /* Sanity check */
+    HDassert(obj_id_count_ptr);
 
     /* Set up search information */
     olist.obj_id_list  = (max_index==0 ? NULL : obj_id_list);
@@ -550,45 +559,50 @@ H5F_get_objects(const H5F_t *f, unsigned types, size_t max_index, hid_t *obj_id_
         olist.file_info.ptr.shared = f ? f->shared : NULL;
     } /* end else */
 
-    /* Search through file IDs to count the number, and put their
-     * IDs on the object list.  H5I_search returns NULL if no object
-     * is found, so don't return failure in this function. */
+    /* Iterate through file IDs to count the number, and put their
+     * IDs on the object list.  */
     if(types & H5F_OBJ_FILE) {
         olist.obj_type = H5I_FILE;
-        (void)H5I_search(H5I_FILE, H5F_get_objects_cb, &olist, app_ref);
+        if(H5I_iterate(H5I_FILE, H5F_get_objects_cb, &olist, app_ref) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_BADITER, FAIL, "iteration failed(1)")
     } /* end if */
 
     /* Search through dataset IDs to count number of datasets, and put their
      * IDs on the object list */
     if(types & H5F_OBJ_DATASET) {
         olist.obj_type = H5I_DATASET;
-        (void)H5I_search(H5I_DATASET, H5F_get_objects_cb, &olist, app_ref);
-    }
+        if(H5I_iterate(H5I_DATASET, H5F_get_objects_cb, &olist, app_ref) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_BADITER, FAIL, "iteration failed(2)")
+    } /* end if */
 
     /* Search through group IDs to count number of groups, and put their
      * IDs on the object list */
     if(types & H5F_OBJ_GROUP) {
         olist.obj_type = H5I_GROUP;
-        (void)H5I_search(H5I_GROUP, H5F_get_objects_cb, &olist, app_ref);
-    }
+        if(H5I_iterate(H5I_GROUP, H5F_get_objects_cb, &olist, app_ref) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_BADITER, FAIL, "iteration failed(3)")
+    } /* end if */
 
     /* Search through datatype IDs to count number of named datatypes, and put their
      * IDs on the object list */
     if(types & H5F_OBJ_DATATYPE) {
         olist.obj_type = H5I_DATATYPE;
-        (void)H5I_search(H5I_DATATYPE, H5F_get_objects_cb, &olist, app_ref);
-    }
+        if(H5I_iterate(H5I_DATATYPE, H5F_get_objects_cb, &olist, app_ref) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_BADITER, FAIL, "iteration failed(4)")
+    } /* end if */
 
     /* Search through attribute IDs to count number of attributes, and put their
      * IDs on the object list */
     if(types & H5F_OBJ_ATTR) {
         olist.obj_type = H5I_ATTR;
-        (void)H5I_search(H5I_ATTR, H5F_get_objects_cb, &olist, app_ref);
-    }
+        if(H5I_iterate(H5I_ATTR, H5F_get_objects_cb, &olist, app_ref) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_BADITER, FAIL, "iteration failed(5)")
+    } /* end if */
 
     /* Set the number of objects currently open */
-    ret_value = obj_id_count;
+    *obj_id_count_ptr = obj_id_count;
 
+done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5F_get_objects() */
 
@@ -606,8 +620,6 @@ H5F_get_objects(const H5F_t *f, unsigned types, size_t max_index, hid_t *obj_id_
  * Programmer:  Raymond Lu
  *              Wednesday, Dec 5, 2001
  *
- * Modification:
- *
  *-------------------------------------------------------------------------
  */
 static int
@@ -639,8 +651,8 @@ H5F_get_objects_cb(void *obj_ptr, hid_t obj_id, void *key)
 
             /* Check if we've filled up the array.  Return TRUE only if
              * we have filled up the array. Otherwise return FALSE(RET_VALUE is
-             * preset to FALSE) because H5I_search needs the return value of FALSE
-             * to continue searching. */
+             * preset to FALSE) because H5I_iterate needs the return value of 
+ 	     * FALSE to continue the iteration. */
             if(olist->max_index>0 && olist->list_index>=olist->max_index)
                 HGOTO_DONE(TRUE)  /* Indicate that the iterator should stop */
 	}
@@ -704,8 +716,8 @@ H5F_get_objects_cb(void *obj_ptr, hid_t obj_id, void *key)
 
             /* Check if we've filled up the array.  Return TRUE only if
              * we have filled up the array. Otherwise return FALSE(RET_VALUE is
-             * preset to FALSE) because H5I_search needs the return value of FALSE
-             * to continue searching. */
+             * preset to FALSE) because H5I_iterate needs the return value of 
+	     * FALSE to continue iterating. */
             if(olist->max_index>0 && olist->list_index>=olist->max_index)
                 HGOTO_DONE(TRUE)  /* Indicate that the iterator should stop */
     	} /* end if */
@@ -1792,8 +1804,6 @@ done:
  * Programmer:	Quincey Koziol
  *		Tuesday, July 19, 2005
  *
- * Modifications:
- *
  *-------------------------------------------------------------------------
  */
 herr_t
@@ -1875,27 +1885,36 @@ H5F_try_close(H5F_t *f)
         if(f->nopen_objs > 0) {
             size_t obj_count;       /* # of open objects */
             hid_t objs[128];        /* Array of objects to close */
+            herr_t result;          /* Local result from obj ID query */
             size_t u;               /* Local index variable */
 
             /* Get the list of IDs of open dataset, group, & attribute objects */
-            while((obj_count = H5F_get_obj_ids(f, H5F_OBJ_LOCAL|H5F_OBJ_DATASET|H5F_OBJ_GROUP|H5F_OBJ_ATTR, (int)(sizeof(objs)/sizeof(objs[0])), objs, FALSE)) != 0) {
+            while((result = H5F_get_obj_ids(f, H5F_OBJ_LOCAL | H5F_OBJ_DATASET | H5F_OBJ_GROUP | H5F_OBJ_ATTR, (int)(sizeof(objs) / sizeof(objs[0])), objs, FALSE, &obj_count)) <= 0
+                    && obj_count != 0 ) {
+
                 /* Try to close all the open objects in this file */
                 for(u = 0; u < obj_count; u++)
                     if(H5I_dec_ref(objs[u]) < 0)
                         HGOTO_ERROR(H5E_ATOM, H5E_CLOSEERROR, FAIL, "can't close object")
             } /* end while */
+            if(result < 0)
+                HGOTO_ERROR(H5E_INTERNAL, H5E_BADITER, FAIL, "H5F_get_obj_ids failed(1)")
 
             /* Get the list of IDs of open named datatype objects */
             /* (Do this separately from the dataset & attribute IDs, because
              * they could be using one of the named datatypes and then the
              * open named datatype ID will get closed twice)
              */
-            while((obj_count = H5F_get_obj_ids(f, H5F_OBJ_LOCAL|H5F_OBJ_DATATYPE, (int)(sizeof(objs)/sizeof(objs[0])), objs, FALSE)) != 0) {
+            while((result = H5F_get_obj_ids(f, H5F_OBJ_LOCAL | H5F_OBJ_DATATYPE, (int)(sizeof(objs) / sizeof(objs[0])), objs, FALSE, &obj_count)) <= 0
+                    && obj_count != 0) {
+
                 /* Try to close all the open objects in this file */
                 for(u = 0; u < obj_count; u++)
                     if(H5I_dec_ref(objs[u]) < 0)
                         HGOTO_ERROR(H5E_ATOM, H5E_CLOSEERROR, FAIL, "can't close object")
             } /* end while */
+            if(result < 0)
+                HGOTO_ERROR(H5E_INTERNAL, H5E_BADITER, FAIL, "H5F_get_obj_ids failed(2)")
         } /* end if */
     } /* end if */
 
@@ -2558,6 +2577,139 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:    H5Fget_file_image
+ *
+ * Purpose:     If a buffer is provided (via the buf_ptr argument) and is 
+ *		big enough (size in buf_len argument), load *buf_ptr with
+ *		an image of the open file whose ID is provided in the 
+ *		file_id parameter, and return the number of bytes copied
+ *		to the buffer.
+ *
+ *		If the buffer exists, but is too small to contain an image
+ *		of the indicated file, return a negative number.
+ *
+ *		Finally, if no buffer is provided, return the size of the 
+ *		buffer needed.  This value is simply the eoa of the target 
+ *		file.
+ *
+ *		Note that any user block is skipped.
+ *
+ *		Also note that the function may not be used on files 
+ *		opened with either the split/multi file driver or the
+ *		family file driver.
+ *
+ *		In the former case, the sparse address space makes the 
+ *		get file image operation impractical, due to the size of
+ *		the image typically required.
+ *
+ *		In the case of the family file driver, the problem is
+ *		the driver message in the super block, which will prevent
+ *		the image being opened with any driver other than the
+ *		family file driver -- which negates the purpose of the 
+ *		operation.  This can be fixed, but no resources for 
+ *		this now.
+ *
+ * Return:      Success:        Bytes copied / number of bytes needed.
+ *              Failure:        negative value
+ *
+ * Programmer:  John Mainzer
+ *              11/15/11
+ *
+ *-------------------------------------------------------------------------
+ */
+ssize_t
+H5Fget_file_image(hid_t file_id, void *buf_ptr, size_t buf_len)
+{
+    H5F_t      *file;                   /* File object for file ID */
+    H5FD_t     *fd_ptr;                 /* file driver */
+    haddr_t     eoa;                    /* End of file address */
+    ssize_t     ret_value;              /* Return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE3("Zs", "i*xz", file_id, buf_ptr, buf_len);
+
+    /* Check args */
+    if(NULL == (file = (H5F_t *)H5I_object_verify(file_id, H5I_FILE)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "not a file ID")
+    if(!file || !file->shared || !file->shared->lf)
+        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "file_id yields invalid file pointer")
+    fd_ptr = file->shared->lf;
+    if(!fd_ptr->cls)
+        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "fd_ptr yields invalid class pointer")
+
+    /* the address space used by the split and multi file drivers is not
+     * a good fit for this call.  Since the plan is to depreciate these
+     * drivers anyway, don't bother to do a "force fit".
+     *
+     * The following clause tests for the multi file driver, and fails
+     * if the supplied file has the multi file driver as its top level
+     * file driver.  However, this test will not work if there is some
+     * other file driver sitting on top of the multi file driver.
+     *
+     * I'm not sure if this is possible at present, but in all likelyhood,
+     * it will become possible in the future.  On the other hand, we may
+     * remove the split/multi file drivers before then.
+     *
+     * I am leaving this solution in for now, but we should review it,
+     * and improve the solution if necessary.
+     *
+     *                                          JRM -- 11/11/22
+     */
+    if(HDstrcmp(fd_ptr->cls->name, "multi") == 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "Not supported for multi file driver.")
+
+    /* While the family file driver is conceptually fully compatible 
+     * with the get file image operation, it sets a file driver message
+     * in the super block that prevents the image being opened with any
+     * driver other than the family file driver.  Needless to say, this
+     * rather defeats the purpose of the get file image operation.
+     *
+     * While this problem is quire solvable, the required time and 
+     * resources are lacking at present.  Hence, for now, we don't
+     * allow the get file image operation to be perfomed on files 
+     * opened with the family file driver.
+     *
+     * Observe that the following test only looks at the top level 
+     * driver, and fails if there is some other driver sitting on to
+     * of the family file driver.  
+     *
+     * I don't think this can happen at present, but that may change
+     * in the future.
+     *                                   JRM -- 12/21/11
+     */
+    if(HDstrcmp(fd_ptr->cls->name, "family") == 0)
+        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "Not supported for family file driver.")
+
+
+    /* Go get the actual file size */
+    if(HADDR_UNDEF == (eoa = H5FD_get_eoa(file->shared->lf, H5FD_MEM_DEFAULT)))
+        HGOTO_ERROR(H5E_FILE, H5E_CANTGET, FAIL, "unable to get file size")
+
+    /* set ret_value = to eoa -- will overwrite this if appropriate */
+    ret_value = (ssize_t)eoa;
+
+    /* test to see if a buffer was provided -- if not, we are done */
+    if(buf_ptr != NULL) {
+        size_t	space_needed;		/* size of file image */
+
+        /* Check for buffer too small */
+        if((haddr_t)buf_len < eoa)
+            HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "supplied buffer too small")
+
+        space_needed = (size_t)eoa;
+
+        /* read in the file image */
+        /* (Note compensation for base address addition in internal routine) */
+        if(H5FD_read(fd_ptr, H5AC_ind_dxpl_id, H5FD_MEM_DEFAULT, 0, space_needed, buf_ptr) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_READERROR, FAIL, "file image read request failed")
+    } /* end if */
+    
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* H5Fget_file_image() */
+
+
+/*-------------------------------------------------------------------------
  * Function:    H5Fget_mdc_config
  *
  * Purpose:     Retrieves the current automatic cache resize configuration
diff --git a/src/H5FD.c b/src/H5FD.c
index ba2bee4..99dd076 100644
--- a/src/H5FD.c
+++ b/src/H5FD.c
@@ -81,6 +81,10 @@ static herr_t H5FD_pl_copy(void *(*copy_func)(const void *), size_t pl_size,
 static herr_t H5FD_pl_close(hid_t driver_id, herr_t (*free_func)(void *),
     void *pl);
 static herr_t H5FD_free_cls(H5FD_class_t *cls);
+static herr_t H5FD_fapl_copy(hid_t driver_id, const void *fapl, void **copied_fapl);
+static herr_t H5FD_dxpl_copy(hid_t driver_id, const void *dxpl, void **copied_dxpl);
+static int H5FD_query(const H5FD_t *f, unsigned long *flags/*out*/);
+static int H5FD_driver_query(const H5FD_class_t *driver, unsigned long *flags/*out*/);
 
 /*********************/
 /* Package Variables */
@@ -768,17 +772,15 @@ done:
  * Programmer:	Robb Matzke
  *              Tuesday, August  3, 1999
  *
- * Modifications:
- *
  *-------------------------------------------------------------------------
  */
-herr_t
+static herr_t
 H5FD_fapl_copy(hid_t driver_id, const void *old_fapl, void **copied_fapl)
 {
     H5FD_class_t *driver;
     herr_t ret_value = SUCCEED;       /* Return value */
 
-    FUNC_ENTER_NOAPI(FAIL)
+    FUNC_ENTER_NOAPI_NOINIT
 
     /* Check args */
     if(NULL == (driver = (H5FD_class_t *)H5I_object(driver_id)))
@@ -889,17 +891,15 @@ done:
  * Programmer:	Robb Matzke
  *              Tuesday, August  3, 1999
  *
- * Modifications:
- *
  *-------------------------------------------------------------------------
  */
-herr_t
+static herr_t
 H5FD_dxpl_copy(hid_t driver_id, const void *old_dxpl, void **copied_dxpl)
 {
     H5FD_class_t *driver;
     herr_t ret_value = SUCCEED;       /* Return value */
 
-    FUNC_ENTER_NOAPI(FAIL)
+    FUNC_ENTER_NOAPI_NOINIT
 
     /* Check args */
     if(NULL == (driver = (H5FD_class_t *)H5I_object(driver_id)))
@@ -1057,6 +1057,8 @@ H5FD_open(const char *name, unsigned flags, hid_t fapl_id, haddr_t maxaddr)
     H5FD_t		*file = NULL;           /* VFD file struct */
     hid_t               driver_id = -1;         /* VFD ID */
     H5P_genplist_t      *plist;                 /* Property list pointer */
+    unsigned long       driver_flags = 0;       /* File-inspecific driver feature flags */
+    H5FD_file_image_info_t file_image_info;     /* Initial file image */
     H5FD_t		*ret_value;             /* Return value */
 
     FUNC_ENTER_NOAPI(NULL)
@@ -1079,6 +1081,19 @@ H5FD_open(const char *name, unsigned flags, hid_t fapl_id, haddr_t maxaddr)
     if(NULL == driver->open)
 	HGOTO_ERROR(H5E_VFL, H5E_UNSUPPORTED, NULL, "file driver has no `open' method")
 
+    /* Query driver flag */
+    H5FD_driver_query(driver, &driver_flags);
+
+    /* Get initial file image info */
+    if(H5P_get(plist, H5F_ACS_FILE_IMAGE_INFO_NAME, &file_image_info) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get file image info")
+
+    /* If an image is provided, make sure the driver supports this feature */
+    HDassert(((file_image_info.buffer != NULL) && (file_image_info.size > 0)) ||
+             ((file_image_info.buffer == NULL) && (file_image_info.size == 0)));
+    if((file_image_info.buffer != NULL) && !(driver_flags & H5FD_FEAT_ALLOW_FILE_IMAGE))
+        HGOTO_ERROR(H5E_VFL, H5E_UNSUPPORTED, NULL, "file image set, but not supported.")
+
     /* Dispatch to file driver */
     if(HADDR_UNDEF == maxaddr)
         maxaddr = driver->maxaddr;
@@ -1336,19 +1351,17 @@ done:
  * Programmer:	Quincey Koziol
  *              Friday, August 25, 2000
  *
- * Modifications:
- *
  *-------------------------------------------------------------------------
  */
-int
+static int
 H5FD_query(const H5FD_t *f, unsigned long *flags/*out*/)
 {
-    int	ret_value=0;
+    int	ret_value = 0;          /* Return value */
 
-    FUNC_ENTER_NOAPI(FAIL)
+    FUNC_ENTER_NOAPI_NOINIT
 
-    assert(f);
-    assert(flags);
+    HDassert(f);
+    HDassert(flags);
 
     /* Check for query driver and call it */
     if(f->cls->query)
@@ -1358,7 +1371,44 @@ H5FD_query(const H5FD_t *f, unsigned long *flags/*out*/)
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-}
+} /* end H5FD_query() */
+
+
+/*-------------------------------------------------------------------------
+* Function:    H5FD_driver_query
+*
+* Purpose: Similar to H5FD_query(), but intended for cases when we don't
+*          have a file available (e.g. before one is opened). Since we
+*          can't use the file to get the driver, the driver is passed in
+*          as a parameter.
+*
+* Return:  Success:    non-negative
+*          Failure:    negative
+*
+* Programmer:  Jacob Gruber
+*              Wednesday, August 17, 2011
+*
+*-------------------------------------------------------------------------
+*/
+static int
+H5FD_driver_query(const H5FD_class_t *driver, unsigned long *flags/*out*/)
+{
+    int ret_value = 0;          /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    HDassert(driver);
+    HDassert(flags);
+
+    /* Check for the driver to query and then query it */
+    if(driver->query)
+        ret_value = (driver->query)(NULL, flags);
+    else 
+        *flags = 0;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5FD_driver_query() */
 
 
 /*-------------------------------------------------------------------------
diff --git a/src/H5FDcore.c b/src/H5FDcore.c
index 68b9dfc..6f9a41a 100644
--- a/src/H5FDcore.c
+++ b/src/H5FDcore.c
@@ -101,6 +101,7 @@ typedef struct H5FD_core_t {
     HANDLE          hFile;      /* Native windows file handle */
 #endif /* H5_HAVE_WIN32_API */
     hbool_t  dirty;      /*changes not saved?    */
+    H5FD_file_image_callbacks_t fi_callbacks; /* file image callbacks */
 } H5FD_core_t;
 
 /* Driver-specific file access properties */
@@ -408,9 +409,10 @@ H5FD_core_open(const char *name, unsigned flags, hid_t fapl_id,
 #ifdef H5_HAVE_WIN32_API
     struct _BY_HANDLE_FILE_INFORMATION fileinfo;
 #endif
-    h5_stat_t    sb;
-    int      fd=-1;
-    H5FD_t    *ret_value;
+    h5_stat_t		sb;
+    int			fd=-1;
+    H5FD_file_image_info_t   file_image_info;
+    H5FD_t		*ret_value;
 
     FUNC_ENTER_NOAPI_NOINIT
 
@@ -432,10 +434,32 @@ H5FD_core_open(const char *name, unsigned flags, hid_t fapl_id,
     if(H5F_ACC_CREAT & flags) o_flags |= O_CREAT;
     if(H5F_ACC_EXCL & flags) o_flags |= O_EXCL;
 
+    /* Retrieve initial file image info */
+    if(H5P_get(plist, H5F_ACS_FILE_IMAGE_INFO_NAME, &file_image_info) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "can't get initial file image info")
+
+    /* If the file image exists and this is an open, make sure the file doesn't exist */
+    HDassert(((file_image_info.buffer != NULL) && (file_image_info.size > 0)) ||
+             ((file_image_info.buffer == NULL) && (file_image_info.size == 0)));
+    if((file_image_info.buffer != NULL) && !(H5F_ACC_CREAT & flags)) {
+        if(HDopen(name, o_flags, 0666) >= 0)
+            HGOTO_ERROR(H5E_FILE, H5E_FILEEXISTS, NULL, "file already exists")
+        
+        /* If backing store is requested, create and stat the file
+         * Note: We are forcing the O_CREAT flag here, even though this is 
+         * technically an open.
+         */
+        if(fa->backing_store) {
+            if((fd = HDopen(name, o_flags | O_CREAT, 0666)) < 0)
+                HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to create file")
+            if(HDfstat(fd, &sb) < 0)
+                HSYS_GOTO_ERROR(H5E_FILE, H5E_BADFILE, NULL, "unable to fstat file")
+        } /* end if */
+    }  /* end if */
     /* Open backing store, and get stat() from file.  The only case that backing
      * store is off is when  the backing_store flag is off and H5F_ACC_CREAT is
      * on. */
-    if(fa->backing_store || !(H5F_ACC_CREAT & flags)) {
+    else if(fa->backing_store || !(H5F_ACC_CREAT & flags)) {
         if(fa && (fd = HDopen(name, o_flags, 0666)) < 0)
             HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to open file")
         if(HDfstat(fd, &sb) < 0)
@@ -458,6 +482,9 @@ H5FD_core_open(const char *name, unsigned flags, hid_t fapl_id,
     /* If save data in backing store. */
     file->backing_store = fa->backing_store;
 
+    /* Save file image callbacks */
+    file->fi_callbacks = file_image_info.callbacks;
+
     if(fd >= 0) {
         /* Retrieve information for determining uniqueness of file */
 #ifdef H5_HAVE_WIN32_API
@@ -489,51 +516,70 @@ H5FD_core_open(const char *name, unsigned flags, hid_t fapl_id,
         size_t size;
 
         /* Retrieve file size */
-  size = (size_t)sb.st_size;
+        if(file_image_info.buffer && file_image_info.size > 0)
+            size = file_image_info.size;
+        else
+            size = (size_t)sb.st_size;
 
         /* Check if we should allocate the memory buffer and read in existing data */
         if(size) {
-            /* Allocate memory for the file's data */
-            if(NULL == (file->mem = (unsigned char*)H5MM_malloc(size)))
-                HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "unable to allocate memory block")
+            /* Allocate memory for the file's data, using the file image callback if available. */
+            if(file->fi_callbacks.image_malloc) {
+                if(NULL == (file->mem = (unsigned char*)file->fi_callbacks.image_malloc(size, H5FD_FILE_IMAGE_OP_FILE_OPEN, file->fi_callbacks.udata)))
+                    HGOTO_ERROR(H5E_FILE, H5E_CANTALLOC, NULL, "image malloc callback failed")
+            } /* end if */
+            else {
+                if(NULL == (file->mem = (unsigned char*)H5MM_malloc(size)))
+                    HGOTO_ERROR(H5E_FILE, H5E_CANTALLOC, NULL, "unable to allocate memory block")
+            } /* end else */
 
             /* Set up data structures */
             file->eof = size;
 
-            /* Read in existing data, being careful of interrupted system calls,
-             * partial results, and the end of the file.
-             */
-            while(size > 0) {
-
-                h5_core_io_t        bytes_in        = 0;    /* # of bytes to read       */
-                h5_core_io_ret_t    bytes_read      = -1;   /* # of bytes actually read */
-                
-                /* Trying to read more bytes than the return type can handle is
-                 * undefined behavior in POSIX.
-                 */
-                if(size > H5_CORE_MAX_IO_BYTES_g)
-                    bytes_in = H5_CORE_MAX_IO_BYTES_g;
-                else
-                    bytes_in = (h5_core_io_t)size;
-                
-                do {
-                    bytes_read = HDread(file->fd, file->mem, bytes_in);
-                } while(-1 == bytes_read && EINTR == errno);
-                
-                if(-1 == bytes_read) { /* error */
-                    int myerrno = errno;
-                    time_t mytime = HDtime(NULL);
-                    HDoff_t myoffset = HDlseek(file->fd, (HDoff_t)0, SEEK_CUR);
-
-                    HGOTO_ERROR(H5E_IO, H5E_READERROR, NULL, "file read failed: time = %s, filename = '%s', file descriptor = %d, errno = %d, error message = '%s', file->mem = %p, size = %lu, offset = %llu", HDctime(&mytime), file->name, file->fd, myerrno, HDstrerror(myerrno), file->mem, (unsigned long)size, (unsigned long long)myoffset);
+            /* If there is an initial file image, copy it, using the callback if possible */
+            if(file_image_info.buffer && file_image_info.size > 0) {
+                if(file->fi_callbacks.image_memcpy) {
+                    if(file->mem != file->fi_callbacks.image_memcpy(file->mem, file_image_info.buffer, size, H5FD_FILE_IMAGE_OP_FILE_OPEN, file->fi_callbacks.udata))
+                        HGOTO_ERROR(H5E_FILE, H5E_CANTCOPY, NULL, "image_memcpy callback failed")
                 } /* end if */
-                
-                HDassert(bytes_read >= 0);
-                HDassert((size_t)bytes_read <= size);
-                
-                size -= (size_t)bytes_read;
-                
-            } /* end while */
+                else
+                    HDmemcpy(file->mem, file_image_info.buffer, size);
+            } /* end if */
+            /* Read in existing data from the file if there is no image */
+            else {
+                /* Read in existing data, being careful of interrupted system calls,
+                 * partial results, and the end of the file.
+                 */
+                while(size > 0) {
+                    h5_core_io_t        bytes_in        = 0;    /* # of bytes to read       */
+                    h5_core_io_ret_t    bytes_read      = -1;   /* # of bytes actually read */
+                    
+                    /* Trying to read more bytes than the return type can handle is
+                     * undefined behavior in POSIX.
+                     */
+                    if(size > H5_CORE_MAX_IO_BYTES_g)
+                        bytes_in = H5_CORE_MAX_IO_BYTES_g;
+                    else
+                        bytes_in = (h5_core_io_t)size;
+                    
+                    do {
+                        bytes_read = HDread(file->fd, file->mem, bytes_in);
+                    } while(-1 == bytes_read && EINTR == errno);
+                    
+                    if(-1 == bytes_read) { /* error */
+                        int myerrno = errno;
+                        time_t mytime = HDtime(NULL);
+                        HDoff_t myoffset = HDlseek(file->fd, (HDoff_t)0, SEEK_CUR);
+
+                        HGOTO_ERROR(H5E_IO, H5E_READERROR, NULL, "file read failed: time = %s, filename = '%s', file descriptor = %d, errno = %d, error message = '%s', file->mem = %p, size = %lu, offset = %llu", HDctime(&mytime), file->name, file->fd, myerrno, HDstrerror(myerrno), file->mem, (unsigned long)size, (unsigned long long)myoffset);
+                    } /* end if */
+                    
+                    HDassert(bytes_read >= 0);
+                    HDassert((size_t)bytes_read <= size);
+                    
+                    size -= (size_t)bytes_read;
+                } /* end while */
+            } /* end else */
         } /* end if */
     } /* end if */
 
@@ -576,8 +622,15 @@ H5FD_core_close(H5FD_t *_file)
         HDclose(file->fd);
     if(file->name)
         H5MM_xfree(file->name);
-    if(file->mem)
-        H5MM_xfree(file->mem);
+    if(file->mem) {
+        /* Use image callback if available */
+        if(file->fi_callbacks.image_free) {
+            if(file->fi_callbacks.image_free(file->mem, H5FD_FILE_IMAGE_OP_FILE_CLOSE, file->fi_callbacks.udata) < 0)
+                HGOTO_ERROR(H5E_FILE, H5E_CANTFREE, FAIL, "image_free callback failed")
+        } /* end if */
+        else
+            H5MM_xfree(file->mem);
+    } /* end if */
     HDmemset(file, 0, sizeof(H5FD_core_t));
     H5MM_xfree(file);
 
@@ -698,9 +751,11 @@ H5FD_core_query(const H5FD_t * _file, unsigned long *flags /* out */)
         *flags |= H5FD_FEAT_ACCUMULATE_METADATA; /* OK to accumulate metadata for faster writes */
         *flags |= H5FD_FEAT_DATA_SIEVE;       /* OK to perform data sieving for faster raw data reads & writes */
         *flags |= H5FD_FEAT_AGGREGATE_SMALLDATA; /* OK to aggregate "small" raw data allocations */
+        *flags |= H5FD_FEAT_ALLOW_FILE_IMAGE;   /* OK to use file image feature with this VFD */
+        *flags |= H5FD_FEAT_CAN_USE_FILE_IMAGE_CALLBACKS;       /* OK to use file image callbacks with this VFD */
 
         /* If the backing store is open, a POSIX file handle is available */
-        if(file->fd >= 0 && file->backing_store)
+        if(file && file->fd >= 0 && file->backing_store)
             *flags |= H5FD_FEAT_POSIX_COMPAT_HANDLE; /* VFD handle is POSIX I/O call compatible */
     } /* end if */
 
@@ -974,9 +1029,16 @@ H5FD_core_write(H5FD_t *_file, H5FD_mem_t UNUSED type, hid_t UNUSED dxpl_id, had
         if((addr + size) % file->increment)
             new_eof += file->increment;
 
-        /* (Re)allocate memory for the file buffer */
-        if(NULL == (x = (unsigned char *)H5MM_realloc(file->mem, new_eof)))
-            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "unable to allocate memory block of %llu bytes", (unsigned long long)new_eof)
+        /* (Re)allocate memory for the file buffer, using callbacks if available */
+        if(file->fi_callbacks.image_realloc) {
+            if(NULL == (x = (unsigned char *)file->fi_callbacks.image_realloc(file->mem, new_eof, H5FD_FILE_IMAGE_OP_FILE_RESIZE, file->fi_callbacks.udata)))
+                HGOTO_ERROR(H5E_FILE, H5E_CANTALLOC, FAIL, "unable to allocate memory block of %llu bytes with callback", (unsigned long long)new_eof)
+        } /* end if */
+        else {
+            if(NULL == (x = (unsigned char *)H5MM_realloc(file->mem, new_eof)))
+                HGOTO_ERROR(H5E_FILE, H5E_CANTALLOC, FAIL, "unable to allocate memory block of %llu bytes", (unsigned long long)new_eof)
+        } /* end else */
+
 #ifdef H5_CLEAR_MEMORY
 HDmemset(x + file->eof, 0, (size_t)(new_eof - file->eof));
 #endif /* H5_CLEAR_MEMORY */
@@ -987,6 +1049,8 @@ HDmemset(x + file->eof, 0, (size_t)(new_eof - file->eof));
 
     /* Write from BUF to memory */
     HDmemcpy(file->mem + addr, buf, size);
+
+    /* Mark memory buffer as modified */
     file->dirty = TRUE;
 
 done:
@@ -1073,8 +1137,30 @@ done:
  * Purpose:  Makes sure that the true file size is the same (or larger)
  *    than the end-of-address.
  *
- * Return:  Success:  Non-negative
- *    Failure:  Negative
+ *		Addendum -- 12/2/11
+ *		For file images opened with the core file driver, it is 
+ *		necessary that we avoid reallocating the core file driver's
+ *		buffer uneccessarily.
+ *
+ *		To this end, I have made the following functional changes
+ *		to this function.  
+ *
+ *		If we are closing, and there is no backing store, this 
+ *		function becomes a no-op.
+ *
+ *		If we are closing, and there is backing store, we set the
+ *		eof to equal the eoa, and truncate the backing store to 
+ *		the new eof
+ *
+ *		If we are not closing, we realloc the buffer to size equal 
+ *		to the smallest multiple of the allocation increment that 
+ *		equals or exceeds the eoa and set the eof accordingly.  
+ *		Note that we no longer truncate	the backing store to the 
+ *		new eof if applicable.
+ *							-- JRM
+ *
+ * Return:	Success:	Non-negative
+ *		Failure:	Negative
  *
  * Programmer:  Quincey Koziol
  *              Tuesday, October  7, 2008
@@ -1083,7 +1169,7 @@ done:
  */
 /* ARGSUSED */
 static herr_t
-H5FD_core_truncate(H5FD_t *_file, hid_t UNUSED dxpl_id, hbool_t UNUSED closing)
+H5FD_core_truncate(H5FD_t *_file, hid_t UNUSED dxpl_id, hbool_t closing)
 {
     H5FD_core_t *file = (H5FD_core_t*)_file;
     size_t new_eof;                             /* New size of memory buffer */
@@ -1093,68 +1179,81 @@ H5FD_core_truncate(H5FD_t *_file, hid_t UNUSED dxpl_id, hbool_t UNUSED closing)
 
     HDassert(file);
 
-    /* Determine new size of memory buffer */
-    H5_ASSIGN_OVERFLOW(new_eof, file->increment * (file->eoa / file->increment), hsize_t, size_t);
-    if(file->eoa % file->increment)
-        new_eof += file->increment;
-
-    /* Extend the file to make sure it's large enough */
-    if(!H5F_addr_eq(file->eof, (haddr_t)new_eof)) {
-        unsigned char *x;       /* Pointer to new buffer for file data */
+    /* if we are closing and not using backing store, do nothing */
+    if(!closing || file->backing_store) {
+        if(closing) /* set eof to eoa */
+            new_eof = file->eoa;
+        else { /* set eof to smallest multiple of increment that exceeds eoa */
+            /* Determine new size of memory buffer */
+            H5_ASSIGN_OVERFLOW(new_eof, file->increment * (file->eoa / file->increment), hsize_t, size_t);
+            if(file->eoa % file->increment)
+                new_eof += file->increment;
+        } /* end else */
+
+        /* Extend the file to make sure it's large enough */
+        if(!H5F_addr_eq(file->eof, (haddr_t)new_eof)) {
+            unsigned char *x;       /* Pointer to new buffer for file data */
+
+            /* (Re)allocate memory for the file buffer, using callback if available */
+            if(file->fi_callbacks.image_realloc) {
+                if(NULL == (x = (unsigned char *)file->fi_callbacks.image_realloc(file->mem, new_eof, H5FD_FILE_IMAGE_OP_FILE_RESIZE, file->fi_callbacks.udata)))
+                  HGOTO_ERROR(H5E_FILE, H5E_CANTALLOC, FAIL, "unable to allocate memory block with callback")
+            } /* end if */
+            else {
+                if(NULL == (x = (unsigned char *)H5MM_realloc(file->mem, new_eof)))
+                    HGOTO_ERROR(H5E_FILE, H5E_CANTALLOC, FAIL, "unable to allocate memory block")
+            } /* end else */
 
-        /* (Re)allocate memory for the file buffer */
-        if(NULL == (x = (unsigned char *)H5MM_realloc(file->mem, new_eof)))
-            HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "unable to allocate memory block")
 #ifdef H5_CLEAR_MEMORY
-if(file->eof < new_eof)
-    HDmemset(x + file->eof, 0, (size_t)(new_eof - file->eof));
+            if(file->eof < new_eof)
+                HDmemset(x + file->eof, 0, (size_t)(new_eof - file->eof));
 #endif /* H5_CLEAR_MEMORY */
-        file->mem = x;
+            file->mem = x;
 
-        /* Update backing store, if using it */
-        if(file->fd >= 0 && file->backing_store) {
+            /* Update backing store, if using it and if closing */
+            if(closing && (file->fd >= 0) && file->backing_store) {
 #ifdef H5_HAVE_WIN32_API
-            LARGE_INTEGER   li;         /* 64-bit (union) integer for SetFilePointer() call */
-            DWORD           dwPtrLow;   /* Low-order pointer bits from SetFilePointer()
-                                         * Only used as an error code here.
-                                         */
-            DWORD           dwError;    /* DWORD error code from GetLastError() */
-            BOOL            bError;     /* Boolean error flag */
-
-            /* Windows uses this odd QuadPart union for 32/64-bit portability */
-            li.QuadPart = (__int64)file->eoa;
-
-            /* Extend the file to make sure it's large enough.
-             *
-             * Since INVALID_SET_FILE_POINTER can technically be a valid return value
-             * from SetFilePointer(), we also need to check GetLastError().
-             */
-            dwPtrLow = SetFilePointer(file->hFile, li.LowPart, &li.HighPart, FILE_BEGIN);
-            if(INVALID_SET_FILE_POINTER == dwPtrLow) {
-                dwError = GetLastError();
-                if(dwError != NO_ERROR )
-                    HGOTO_ERROR(H5E_FILE, H5E_FILEOPEN, FAIL, "unable to set file pointer")
-            }
-
-            bError = SetEndOfFile(file->hFile);
-            if(0 == bError)
-                HGOTO_ERROR(H5E_IO, H5E_SEEKERROR, FAIL, "unable to extend file properly")
+                LARGE_INTEGER   li;         /* 64-bit (union) integer for SetFilePointer() call */
+                DWORD           dwPtrLow;   /* Low-order pointer bits from SetFilePointer()
+                                             * Only used as an error code here.
+                                             */
+                DWORD           dwError;    /* DWORD error code from GetLastError() */
+                BOOL            bError;     /* Boolean error flag */
+
+                /* Windows uses this odd QuadPart union for 32/64-bit portability */
+                li.QuadPart = (__int64)file->eoa;
+
+                /* Extend the file to make sure it's large enough.
+                 *
+                 * Since INVALID_SET_FILE_POINTER can technically be a valid return value
+                 * from SetFilePointer(), we also need to check GetLastError().
+                 */
+                dwPtrLow = SetFilePointer(file->hFile, li.LowPart, &li.HighPart, FILE_BEGIN);
+                if(INVALID_SET_FILE_POINTER == dwPtrLow) {
+                    dwError = GetLastError();
+                    if(dwError != NO_ERROR )
+                        HGOTO_ERROR(H5E_FILE, H5E_FILEOPEN, FAIL, "unable to set file pointer")
+                }
+
+                bError = SetEndOfFile(file->hFile);
+                if(0 == bError)
+                    HGOTO_ERROR(H5E_IO, H5E_SEEKERROR, FAIL, "unable to extend file properly")
 #else /* H5_HAVE_WIN32_API */
 #ifdef H5_VMS
-            /* Reset seek offset to the beginning of the file, so that the file isn't
-             * re-extended later.  This may happen on Open VMS. */
-            if(-1 == HDlseek(file->fd, (HDoff_t)0, SEEK_SET))
-                HSYS_GOTO_ERROR(H5E_IO, H5E_SEEKERROR, FAIL, "unable to seek to proper position")
+                /* Reset seek offset to the beginning of the file, so that the file isn't
+                 * re-extended later.  This may happen on Open VMS. */
+                if(-1 == HDlseek(file->fd, (HDoff_t)0, SEEK_SET))
+                    HSYS_GOTO_ERROR(H5E_IO, H5E_SEEKERROR, FAIL, "unable to seek to proper position")
 #endif
-            if(-1 == HDftruncate(file->fd, (HDoff_t)new_eof))
-                HSYS_GOTO_ERROR(H5E_IO, H5E_SEEKERROR, FAIL, "unable to extend file properly")
+                if(-1 == HDftruncate(file->fd, (HDoff_t)new_eof))
+                    HSYS_GOTO_ERROR(H5E_IO, H5E_SEEKERROR, FAIL, "unable to extend file properly")
 #endif /* H5_HAVE_WIN32_API */
+            } /* end if */
 
+            /* Update the eof value */
+            file->eof = new_eof;
         } /* end if */
-
-        /* Update the eof value */
-        file->eof = new_eof;
-    } /* end if */
+    } /* end if(file->eof < file->eoa) */
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
diff --git a/src/H5FDfamily.c b/src/H5FDfamily.c
index 8b6b819..736efb8 100644
--- a/src/H5FDfamily.c
+++ b/src/H5FDfamily.c
@@ -996,7 +996,7 @@ H5FD_family_query(const H5FD_t * _file, unsigned long *flags /* out */)
         *flags |= H5FD_FEAT_AGGREGATE_SMALLDATA; /* OK to aggregate "small" raw data allocations */
 
         /* Check for flags that are set by h5repart */
-        if(file->repart_members)
+        if(file && file->repart_members)
             *flags |= H5FD_FEAT_DIRTY_SBLK_LOAD; /* Mark the superblock dirty when it is loaded (so the family member sizes are rewritten) */
     } /* end if */
 
diff --git a/src/H5FDlog.c b/src/H5FDlog.c
index 8bb2392..e3d67359 100644
--- a/src/H5FDlog.c
+++ b/src/H5FDlog.c
@@ -916,7 +916,7 @@ H5FD_log_query(const H5FD_t *_file, unsigned long *flags /* out */)
         *flags |= H5FD_FEAT_POSIX_COMPAT_HANDLE; /* VFD handle is POSIX I/O call compatible */
 
         /* Check for flags that are set by h5repart */
-        if(file->fam_to_sec2)
+        if(file && file->fam_to_sec2)
             *flags |= H5FD_FEAT_IGNORE_DRVRINFO; /* Ignore the driver info when file is opened (which eliminates it) */
     } /* end if */
 
diff --git a/src/H5FDprivate.h b/src/H5FDprivate.h
index 4f7d059..9c19562 100644
--- a/src/H5FDprivate.h
+++ b/src/H5FDprivate.h
@@ -52,6 +52,29 @@ typedef enum {
 } H5FD_file_op_t;
 
 
+/* Define structure to hold initial file image and other relevant information */
+typedef struct {
+    void *buffer;
+    size_t size;
+    H5FD_file_image_callbacks_t callbacks;
+} H5FD_file_image_info_t;
+
+/* Define default file image info */
+#define H5FD_DEFAULT_FILE_IMAGE_INFO { \
+    /* file image buffer */ NULL,       \
+    /* buffer size */       0,          \
+    { /* Callbacks */                   \
+        /* image_malloc */      NULL,   \
+        /* image_memcpy */      NULL,   \
+        /* image_realloc */     NULL,   \
+        /* image_free */        NULL,   \
+        /* udata_copy */        NULL,   \
+        /* udata_free */        NULL,   \
+        /* udata */             NULL,   \
+    }                                   \
+}
+
+
 /*****************************/
 /* Library Private Variables */
 /*****************************/
@@ -72,17 +95,14 @@ H5_DLL herr_t H5FD_sb_encode(H5FD_t *file, char *name/*out*/, uint8_t *buf);
 H5_DLL herr_t H5FD_sb_decode(H5FD_t *file, const char *name, const uint8_t *buf);
 H5_DLL void *H5FD_fapl_get(H5FD_t *file);
 H5_DLL herr_t H5FD_fapl_open(struct H5P_genplist_t *plist, hid_t driver_id, const void *driver_info);
-H5_DLL herr_t H5FD_fapl_copy(hid_t driver_id, const void *fapl, void **copied_fapl);
 H5_DLL herr_t H5FD_fapl_close(hid_t driver_id, void *fapl);
 H5_DLL herr_t H5FD_dxpl_open(struct H5P_genplist_t *plist, hid_t driver_id, const void *driver_info);
-H5_DLL herr_t H5FD_dxpl_copy(hid_t driver_id, const void *dxpl, void **copied_dxpl);
 H5_DLL herr_t H5FD_dxpl_close(hid_t driver_id, void *dxpl);
 H5_DLL hid_t H5FD_register(const void *cls, size_t size, hbool_t app_ref);
 H5_DLL H5FD_t *H5FD_open(const char *name, unsigned flags, hid_t fapl_id,
 		  haddr_t maxaddr);
 H5_DLL herr_t H5FD_close(H5FD_t *file);
 H5_DLL int H5FD_cmp(const H5FD_t *f1, const H5FD_t *f2);
-H5_DLL int H5FD_query(const H5FD_t *f, unsigned long *flags/*out*/);
 H5_DLL haddr_t H5FD_alloc(H5FD_t *file, hid_t dxpl_id, H5FD_mem_t type, struct H5F_t *f,
     hsize_t size, haddr_t *align_addr, hsize_t *align_size);
 H5_DLL herr_t H5FD_free(H5FD_t *file, hid_t dxpl_id, H5FD_mem_t type, struct H5F_t *f,
diff --git a/src/H5FDpublic.h b/src/H5FDpublic.h
index cd6c964..0c5605c 100644
--- a/src/H5FDpublic.h
+++ b/src/H5FDpublic.h
@@ -177,6 +177,18 @@ typedef enum H5F_mem_t	H5FD_mem_t;
      * of type 'int' and is compatible with POSIX I/O calls.
      */
 #define H5FD_FEAT_POSIX_COMPAT_HANDLE   0x00000080
+    /* 
+     * Defining the H5FD_FEAT_ALLOW_FILE_IMAGE for a VFL driver means that
+     * the driver is able to use a file image in the fapl as the initial
+     * contents of a file.
+     */
+#define H5FD_FEAT_ALLOW_FILE_IMAGE      0x00000400
+    /*
+     * Defining the H5FD_FEAT_CAN_USE_FILE_IMAGE_CALLBACKS for a VFL driver
+     * means that the driver is able to use callbacks to make a copy of the
+     * image to store in memory.
+     */
+#define H5FD_FEAT_CAN_USE_FILE_IMAGE_CALLBACKS 0x00000800
 
 
 /* Forward declaration */
@@ -246,6 +258,33 @@ struct H5FD_t {
     hsize_t             alignment;      /* Allocation alignment     */
 };
 
+/* Define enum for the source of file image callbacks */
+typedef enum {
+    H5FD_FILE_IMAGE_OP_NO_OP,
+    H5FD_FILE_IMAGE_OP_PROPERTY_LIST_SET,     
+    H5FD_FILE_IMAGE_OP_PROPERTY_LIST_COPY,
+    H5FD_FILE_IMAGE_OP_PROPERTY_LIST_GET,
+    H5FD_FILE_IMAGE_OP_PROPERTY_LIST_CLOSE,
+    H5FD_FILE_IMAGE_OP_FILE_OPEN,
+    H5FD_FILE_IMAGE_OP_FILE_RESIZE,
+    H5FD_FILE_IMAGE_OP_FILE_CLOSE,
+} H5FD_file_image_op_t;
+
+/* Define structure to hold file image callbacks */
+typedef struct {
+    void   *(*image_malloc)(size_t size, H5FD_file_image_op_t file_image_op, 
+                            void *udata);
+    void   *(*image_memcpy)(void *dest, const void *src, size_t size,
+                            H5FD_file_image_op_t file_image_op, void *udata);
+    void   *(*image_realloc)(void *ptr, size_t size, 
+                            H5FD_file_image_op_t file_image_op, void *udata);
+    herr_t  (*image_free)(void *ptr, H5FD_file_image_op_t file_image_op, 
+                          void *udata);
+    void   *(*udata_copy)(void *udata);
+    herr_t  (*udata_free)(void *udata);
+    void *udata;
+} H5FD_file_image_callbacks_t;
+
 #ifdef __cplusplus
 extern "C" {
 #endif
diff --git a/src/H5FDsec2.c b/src/H5FDsec2.c
index c3a25c9..868d4a4 100644
--- a/src/H5FDsec2.c
+++ b/src/H5FDsec2.c
@@ -558,7 +558,7 @@ H5FD_sec2_query(const H5FD_t *_file, unsigned long *flags /* out */)
         *flags |= H5FD_FEAT_POSIX_COMPAT_HANDLE;    /* VFD handle is POSIX I/O call compatible                          */
 
         /* Check for flags that are set by h5repart */
-        if(file->fam_to_sec2)
+        if(file && file->fam_to_sec2)
             *flags |= H5FD_FEAT_IGNORE_DRVRINFO; /* Ignore the driver info when file is opened (which eliminates it) */
     } /* end if */
 
diff --git a/src/H5Fprivate.h b/src/H5Fprivate.h
index f659491..b0aaeec 100644
--- a/src/H5Fprivate.h
+++ b/src/H5Fprivate.h
@@ -415,6 +415,7 @@ typedef struct H5F_blk_aggr_t H5F_blk_aggr_t;
 #define H5F_ACS_LATEST_FORMAT_NAME              "latest_format" /* 'Use latest format version' flag */
 #define H5F_ACS_WANT_POSIX_FD_NAME              "want_posix_fd" /* Internal: query the file descriptor from the core VFD, instead of the memory address */
 #define H5F_ACS_EFC_SIZE_NAME                   "efc_size"      /* Size of external file cache */
+#define H5F_ACS_FILE_IMAGE_INFO_NAME            "file_image_info" /* struct containing initial file image and callback info */
 
 /* ======================== File Mount properties ====================*/
 #define H5F_MNT_SYM_LOCAL_NAME 		"local"                 /* Whether absolute symlinks local to file. */
@@ -516,8 +517,8 @@ H5_DLL H5F_t *H5F_get_parent(const H5F_t *f);
 H5_DLL unsigned H5F_get_nmounts(const H5F_t *f);
 H5_DLL hid_t H5F_get_access_plist(H5F_t *f, hbool_t app_ref);
 H5_DLL hid_t H5F_get_id(H5F_t *file, hbool_t app_ref);
-H5_DLL size_t H5F_get_obj_count(const H5F_t *f, unsigned types, hbool_t app_ref);
-H5_DLL size_t H5F_get_obj_ids(const H5F_t *f, unsigned types, size_t max_objs, hid_t *obj_id_list, hbool_t app_ref);
+H5_DLL herr_t H5F_get_obj_count(const H5F_t *f, unsigned types, hbool_t app_ref, size_t *obj_id_count_ptr);
+H5_DLL herr_t H5F_get_obj_ids(const H5F_t *f, unsigned types, size_t max_objs, hid_t *oid_list, hbool_t app_ref, size_t *obj_id_count_ptr);
 
 /* Functions than retrieve values set/cached from the superblock/FCPL */
 H5_DLL haddr_t H5F_get_base_addr(const H5F_t *f);
diff --git a/src/H5Fpublic.h b/src/H5Fpublic.h
index 454e43a..8466a26 100644
--- a/src/H5Fpublic.h
+++ b/src/H5Fpublic.h
@@ -169,6 +169,7 @@ H5_DLL herr_t H5Fmount(hid_t loc, const char *name, hid_t child, hid_t plist);
 H5_DLL herr_t H5Funmount(hid_t loc, const char *name);
 H5_DLL hssize_t H5Fget_freespace(hid_t file_id);
 H5_DLL herr_t H5Fget_filesize(hid_t file_id, hsize_t *size);
+H5_DLL ssize_t H5Fget_file_image(hid_t file_id, void * buf_ptr, size_t buf_len);
 H5_DLL herr_t H5Fget_mdc_config(hid_t file_id,
 				H5AC_cache_config_t * config_ptr);
 H5_DLL herr_t H5Fset_mdc_config(hid_t file_id,
diff --git a/src/H5Gname.c b/src/H5Gname.c
index 25639f2d..e925313 100644
--- a/src/H5Gname.c
+++ b/src/H5Gname.c
@@ -782,7 +782,7 @@ done:
 /*-------------------------------------------------------------------------
  * Function: H5G_name_replace_cb
  *
- * Purpose: H5I_search callback function to replace group entry names
+ * Purpose: H5I_iterate callback function to replace group entry names
  *
  * Return: Success: 0, Failure: -1
  *
@@ -1166,15 +1166,18 @@ H5G_name_replace(const H5O_link_t *lnk, H5G_names_op_t op, H5F_t *src_file,
 
             /* Search through group IDs */
             if(search_group)
-                H5I_search(H5I_GROUP, H5G_name_replace_cb, &names, FALSE);
+                if(H5I_iterate(H5I_GROUP, H5G_name_replace_cb, &names, FALSE) < 0)
+		    HGOTO_ERROR(H5E_SYM, H5E_BADITER, FAIL, "can't iterate over groups")
 
             /* Search through dataset IDs */
             if(search_dataset)
-                H5I_search(H5I_DATASET, H5G_name_replace_cb, &names, FALSE);
+                if(H5I_iterate(H5I_DATASET, H5G_name_replace_cb, &names, FALSE) < 0)
+		    HGOTO_ERROR(H5E_SYM, H5E_BADITER, FAIL, "can't iterate over datasets")
 
             /* Search through datatype IDs */
             if(search_datatype)
-                H5I_search(H5I_DATATYPE, H5G_name_replace_cb, &names, FALSE);
+                if(H5I_iterate(H5I_DATATYPE, H5G_name_replace_cb, &names, FALSE) < 0)
+		    HGOTO_ERROR(H5E_SYM, H5E_BADITER, FAIL, "can't iterate over datatypes")
         } /* end if */
     } /* end if */
 
diff --git a/src/H5I.c b/src/H5I.c
index 13a07f9..ce81f3c 100644
--- a/src/H5I.c
+++ b/src/H5I.c
@@ -115,6 +115,11 @@ typedef struct {
     H5I_id_info_t **id_list;	/*pointer to an array of ptrs to IDs	    */
 } H5I_id_type_t;
 
+typedef struct {
+    H5I_search_func_t app_cb;   /* Application's callback routine */
+    void *app_key;              /* Application's "key" (user data) */
+    void *ret_obj;              /* Object to return */
+} H5I_search_ud_t;
 
 /*-------------------- Locally scoped variables -----------------------------*/
 
@@ -134,6 +139,7 @@ H5FL_DEFINE_STATIC(H5I_id_info_t);
 
 /*--------------------- Local function prototypes ---------------------------*/
 static H5I_id_info_t *H5I_find_id(hid_t id);
+static int H5I_search_cb(void *obj, hid_t id, void *udata);
 #ifdef H5I_DEBUG_OUTPUT
 static herr_t H5I_debug(H5I_type_t type);
 #endif /* H5I_DEBUG_OUTPUT */
@@ -1978,6 +1984,40 @@ done:
 
 
 /*-------------------------------------------------------------------------
+ * Function:	H5I_search_cb
+ *
+ * Purpose:	Callback routine for H5Isearch, when it calls H5I_iterate.
+ *		Calls "user" callback search function, and then sets return
+ *		value, based on the result of that callback.
+ *
+ * Return:	Success:	The first object in the type for which FUNC
+ *				returns non-zero. NULL if FUNC returned zero
+ *				for every object in the type.
+ *		Failure:	NULL
+ *
+ * Programmer:	Quincey Koziol
+ *		Friday, March 30, 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+static int
+H5I_search_cb(void *obj, hid_t id, void *_udata)
+{
+    H5I_search_ud_t *udata = (H5I_search_ud_t *)_udata; /* User data for callback */
+    int ret_value;     /* Callback return value */
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    ret_value = (*udata->app_cb)(obj, id, udata->app_key);
+    if(ret_value > 0)
+        udata->ret_obj = obj;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5I_search_cb() */
+
+
+/*-------------------------------------------------------------------------
  * Function:	H5Isearch
  *
  * Purpose:	Apply function FUNC to each member of type TYPE and return a
@@ -2004,14 +2044,27 @@ done:
 void *
 H5Isearch(H5I_type_t type, H5I_search_func_t func, void *key)
 {
-    void * ret_value;                      /* Return value */
+    H5I_search_ud_t udata;      /* Context for iteration */
+    void *ret_value;            /* Return value */
 
     FUNC_ENTER_API(NULL)
 
+    /* Check arguments */
     if(H5I_IS_LIB_TYPE(type))
         HGOTO_ERROR(H5E_ATOM, H5E_BADGROUP, NULL, "cannot call public function on library type")
 
-    ret_value = H5I_search(type, func, key, TRUE);
+    /* Set up udata struct */
+    udata.app_cb = func;
+    udata.app_key = key;
+    udata.ret_obj = NULL;
+
+    /* Note that H5I_iterate returns an error code.  We ignore it 
+     * here, as we can't do anything with it without revising the API.
+     */
+    H5I_iterate(type, H5I_search_cb, &udata, TRUE);
+
+    /* Set return value */
+    ret_value = udata.ret_obj;
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -2019,62 +2072,71 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5I_search
+ * Function:	H5I_iterate
  *
- * Purpose:	Apply function FUNC to each member of type TYPE and return a
- *		pointer to the first object for which FUNC returns non-zero.
- *		The FUNC should take a pointer to the object and the KEY as
- *		arguments and return non-zero to terminate the search (zero
- *		to continue).
+ * Purpose:	Apply function FUNC to each member of type TYPE (with 
+ *		non-zero application reference count if app_ref is TRUE).  
+ *		Stop if FUNC returns a non zero value (i.e. anything 
+ *		other than H5_ITER_CONT).  
  *
- * Limitation:	Currently there is no way to start searching from where a
- *		previous search left off.
+ *		If FUNC returns a positive value (i.e. H5_ITER_STOP), 
+ *		return SUCCEED.
  *
- * Return:	Success:	The first object in the type for which FUNC
- *				returns non-zero. NULL if FUNC returned zero
- *				for every object in the type.
- *		Failure:	NULL
+ *		If FUNC returns a negative value (i.e. H5_ITER_ERROR), 
+ *		return FAIL.
+ *		
+ *		The FUNC should take a pointer to the object and the 
+ *		udata as arguments and return non-zero to terminate 
+ *		siteration, and zero to continue.
  *
- * Programmer:	Robb Matzke
- *		Friday, February 19, 1999
+ * Limitation:	Currently there is no way to start the iteration from 
+ *		where a previous iteration left off.
+ *
+ * Return:	Success:	SUCCEED
+ *		Failure:	FAIL
  *
- * Modifications:  Neil Fortner
- *      Wednesday, October 1, 2008
- *      Added app_ref parameter.  When set to TRUE, the function will only
- *      operate on ids that have a nonzero application reference count.
+ * Programmer:	John Mainzer
+ *		Monday, December 6, 2011
  *
  *-------------------------------------------------------------------------
  */
-void *
-H5I_search(H5I_type_t type, H5I_search_func_t func, void *key, hbool_t app_ref)
+herr_t
+H5I_iterate(H5I_type_t type, H5I_search_func_t func, void *udata, hbool_t app_ref)
 {
-    H5I_id_type_t	*type_ptr;	/*ptr to the type	*/
-    void		*ret_value = NULL;	/*return value		*/
+    H5I_id_type_t *type_ptr;		/*ptr to the type	*/
+    herr_t	   ret_value = SUCCEED;	/*return value		*/
 
-    FUNC_ENTER_NOAPI(NULL)
+    FUNC_ENTER_NOAPI(FAIL)
 
     /* Check arguments */
     if(type <= H5I_BADID || type >= H5I_next_type)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADRANGE, NULL, "invalid type number")
+	HGOTO_ERROR(H5E_ARGS, H5E_BADRANGE, FAIL, "invalid type number")
     type_ptr = H5I_id_type_list_g[type];
-    if(type_ptr == NULL || type_ptr->count <= 0)
-	HGOTO_ERROR(H5E_ATOM, H5E_BADGROUP, NULL, "invalid type")
 
-    /* Only iterate through hash table if there are IDs in group */
-    if(type_ptr->ids > 0) {
-        H5I_id_info_t	*id_ptr;	/*ptr to the new ID	*/
-        H5I_id_info_t	*next_id;	/*ptr to the next ID	*/
-        unsigned i;			/*counter		*/
+    /* Only iterate through hash table if it is initialized and there are IDs in group */
+    if(type_ptr && type_ptr->count > 0 && type_ptr->ids > 0) {
+        unsigned u;			/* Counter		*/
 
         /* Start at the beginning of the array */
-        for(i = 0; i < type_ptr->hash_size; i++) {
-            id_ptr = type_ptr->id_list[i];
+        for(u = 0; u < type_ptr->hash_size; u++) {
+            H5I_id_info_t	*id_ptr;	/* Ptr to the new ID	*/
+
+            id_ptr = type_ptr->id_list[u];
             while(id_ptr) {
-                next_id = id_ptr->next;      /* Protect against ID being deleted in callback */
-                /* (Casting away const OK -QAK) */
-                if((!app_ref || id_ptr->app_count) && (*func)((void *)id_ptr->obj_ptr, id_ptr->id, key))
-                    /* (Casting away const OK -QAK) */
-                    HGOTO_DONE((void *)id_ptr->obj_ptr);	/*found the item*/
+                H5I_id_info_t	*next_id;	/* Ptr to the next ID	*/
+
+                /* Protect against ID being deleted in callback */
+                next_id = id_ptr->next;
+                if((!app_ref) || (id_ptr->app_count > 0)) {
+                    herr_t cb_ret_val;  /* Callback return value */
+
+                    /* (Casting away const OK) */
+		    cb_ret_val = (*func)((void *)id_ptr->obj_ptr, id_ptr->id, udata);
+		    if(cb_ret_val > 0)
+                        HGOTO_DONE(SUCCEED)	/* terminate iteration early */
+		    else if(cb_ret_val < 0)
+			HGOTO_ERROR(H5E_ARGS, H5E_BADRANGE, FAIL, "func failed")
+		} /* end if */
                 id_ptr = next_id;
             } /* end while */
         } /* end for */
@@ -2082,7 +2144,7 @@ H5I_search(H5I_type_t type, H5I_search_func_t func, void *key, hbool_t app_ref)
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5I_search() */
+} /* end H5I_iterate() */
 
 
 /*-------------------------------------------------------------------------
diff --git a/src/H5Iprivate.h b/src/H5Iprivate.h
index 98423df..bc0ef41 100644
--- a/src/H5Iprivate.h
+++ b/src/H5Iprivate.h
@@ -62,7 +62,7 @@ H5_DLL H5I_type_t H5I_get_type(hid_t id);
 H5_DLL hid_t H5I_get_file_id(hid_t obj_id, hbool_t app_ref);
 H5_DLL void *H5I_remove(hid_t id);
 H5_DLL void *H5I_remove_verify(hid_t id, H5I_type_t id_type);
-H5_DLL void *H5I_search(H5I_type_t type, H5I_search_func_t func, void *key, hbool_t app_ref);
+H5_DLL herr_t H5I_iterate(H5I_type_t type, H5I_search_func_t func, void *udata, hbool_t app_ref);
 H5_DLL int H5I_get_ref(hid_t id, hbool_t app_ref);
 H5_DLL int H5I_inc_ref(hid_t id, hbool_t app_ref);
 H5_DLL int H5I_dec_ref(hid_t id);
diff --git a/src/H5Oattribute.c b/src/H5Oattribute.c
index bbaf72b..0ab74ac 100644
--- a/src/H5Oattribute.c
+++ b/src/H5Oattribute.c
@@ -711,18 +711,23 @@ H5O_attr_find_opened_attr(const H5O_loc_t *loc, H5A_t **attr, const char* name_t
         HGOTO_ERROR(H5E_ATTR, H5E_BADVALUE, FAIL, "can't get file serial number")
 
     /* Count all opened attributes */
-    num_open_attr = H5F_get_obj_count(loc->file, H5F_OBJ_ATTR | H5F_OBJ_LOCAL, FALSE);
+    if(H5F_get_obj_count(loc->file, H5F_OBJ_ATTR | H5F_OBJ_LOCAL, FALSE, &num_open_attr) < 0)
+        HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "can't count opened attributes")
 
     /* Find out whether the attribute has been opened */
     if(num_open_attr) {
+        size_t check_num_attr;  /* Number of open attribute IDs */
         size_t u;          /* Local index variable */
 
         /* Allocate space for the attribute ID list */
         if(NULL == (attr_id_list = (hid_t *)H5MM_malloc(num_open_attr * sizeof(hid_t))))
-            HGOTO_ERROR(H5E_ATTR, H5E_NOSPACE, FAIL, "unable to allocate memory for attribute ID list")
+            HGOTO_ERROR(H5E_ATTR, H5E_CANTALLOC, FAIL, "unable to allocate memory for attribute ID list")
 
         /* Retrieve the IDs of all opened attributes */
-        H5F_get_obj_ids(loc->file, H5F_OBJ_ATTR | H5F_OBJ_LOCAL, num_open_attr, attr_id_list, FALSE);
+        if(H5F_get_obj_ids(loc->file, H5F_OBJ_ATTR | H5F_OBJ_LOCAL, num_open_attr, attr_id_list, FALSE, &check_num_attr) < 0)
+            HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "can't get IDs of opened attributes")
+	if(check_num_attr != num_open_attr)
+            HGOTO_ERROR(H5E_INTERNAL, H5E_BADITER, FAIL, "open attribute count mismatch")
 
         /* Iterate over the attributes */
         for(u = 0; u < num_open_attr; u++) {
diff --git a/src/H5Pfapl.c b/src/H5Pfapl.c
index c3371c9..7f72c85 100644
--- a/src/H5Pfapl.c
+++ b/src/H5Pfapl.c
@@ -40,6 +40,7 @@
 #include "H5Fprivate.h"		/* Files		  	*/
 #include "H5FDprivate.h"	/* File drivers				*/
 #include "H5Iprivate.h"		/* IDs			  		*/
+#include "H5MMprivate.h"        /* Memory Management    */
 #include "H5Ppkg.h"		/* Property lists		  	*/
 
 /* Includes needed to set as default file driver */
@@ -122,6 +123,12 @@
 /* Definition for external file cache size */
 #define H5F_ACS_EFC_SIZE_SIZE                   sizeof(unsigned)
 #define H5F_ACS_EFC_SIZE_DEF                    0
+/* Definition of pointer to initial file image info */
+#define H5F_ACS_FILE_IMAGE_INFO_SIZE            sizeof(H5FD_file_image_info_t)
+#define H5F_ACS_FILE_IMAGE_INFO_DEF             H5FD_DEFAULT_FILE_IMAGE_INFO
+#define H5F_ACS_FILE_IMAGE_INFO_DEL             H5P_file_image_info_del
+#define H5F_ACS_FILE_IMAGE_INFO_COPY            H5P_file_image_info_copy
+#define H5F_ACS_FILE_IMAGE_INFO_CLOSE           H5P_file_image_info_close
 
 
 /******************/
@@ -149,6 +156,10 @@ static herr_t H5P_facc_reg_prop(H5P_genclass_t *pclass);
 static herr_t H5P_facc_create(hid_t fapl_id, void *copy_data);
 static herr_t H5P_facc_copy(hid_t new_plist_t, hid_t old_plist_t, void *copy_data);
 
+/* File image info property callbacks */
+static herr_t H5P_file_image_info_del(hid_t prop_id, const char *name, size_t size, void *value);
+static herr_t H5P_file_image_info_copy(const char *name, size_t size, void *value);
+static herr_t H5P_file_image_info_close(const char *name, size_t size, void *value);
 
 /*********************/
 /* Package Variables */
@@ -215,6 +226,7 @@ H5P_facc_reg_prop(H5P_genclass_t *pclass)
     hbool_t latest_format = H5F_ACS_LATEST_FORMAT_DEF;          /* Default setting for "use the latest version of the format" flag */
     hbool_t want_posix_fd = H5F_ACS_WANT_POSIX_FD_DEF;          /* Default setting for retrieving 'handle' from core VFD */
     unsigned efc_size = H5F_ACS_EFC_SIZE_DEF;                   /* Default external file cache size */
+    H5FD_file_image_info_t file_image_info = H5F_ACS_FILE_IMAGE_INFO_DEF;  /* Default file image info and callbacks */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
@@ -300,6 +312,10 @@ H5P_facc_reg_prop(H5P_genclass_t *pclass)
     if(H5P_register_real(pclass, H5F_ACS_EFC_SIZE_NAME, H5F_ACS_EFC_SIZE_SIZE, &efc_size, NULL, NULL, NULL, NULL, NULL, NULL, NULL) < 0)
          HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
 
+    /* Register the initial file image info */
+    if(H5P_register_real(pclass, H5F_ACS_FILE_IMAGE_INFO_NAME, H5F_ACS_FILE_IMAGE_INFO_SIZE, &file_image_info, NULL, NULL, NULL, H5F_ACS_FILE_IMAGE_INFO_DEL, H5F_ACS_FILE_IMAGE_INFO_COPY, NULL, H5F_ACS_FILE_IMAGE_INFO_CLOSE) < 0)
+         HGOTO_ERROR(H5E_PLIST, H5E_CANTINSERT, FAIL, "can't insert property into class")
+
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5P_facc_reg_prop() */
@@ -2101,3 +2117,484 @@ done:
     FUNC_LEAVE_API(ret_value)
 } /* end H5Pget_elink_file_cache_size() */
 
+
+/*-------------------------------------------------------------------------
+ * Function: H5Pset_file_image
+ *
+ * Purpose:     Sets the initial file image. Some file drivers can initialize 
+ *              the starting data in a file from a buffer. 
+ *              
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Jacob Gruber
+ *              Thurday, August 11, 2011
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Pset_file_image(hid_t fapl_id, void *buf_ptr, size_t buf_len)
+{
+    H5P_genplist_t *fapl;               /* Property list pointer */
+    H5FD_file_image_info_t image_info;  /* File image info */
+    herr_t ret_value = SUCCEED;         /* Return value */
+    
+    FUNC_ENTER_API(FAIL)
+    H5TRACE3("e", "i*xz", fapl_id, buf_ptr, buf_len);
+
+    /* validate parameters */
+    if(!(((buf_ptr == NULL) && (buf_len == 0)) || ((buf_ptr != NULL) && (buf_len > 0))))
+        HGOTO_ERROR (H5E_ARGS, H5E_BADVALUE, FAIL, "inconsistant buf_ptr and buf_len");
+   
+    /* Get the plist structure */
+    if(NULL == (fapl = H5P_object_verify(fapl_id, H5P_FILE_ACCESS)))
+        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't find object for ID")
+        
+    /* Get old image info */
+    if(H5P_get(fapl, H5F_ACS_FILE_IMAGE_INFO_NAME, &image_info) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get old file image pointer")
+        
+    /* Release previous buffer, if it exists */
+    if(image_info.buffer != NULL) {
+        if(image_info.callbacks.image_free) {
+            if(SUCCEED != image_info.callbacks.image_free(image_info.buffer, H5FD_FILE_IMAGE_OP_PROPERTY_LIST_SET, image_info.callbacks.udata))
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, FAIL, "image_free callback failed")
+        } /* end if */
+        else
+            H5MM_xfree(image_info.buffer);
+    } /* end if */  
+    
+    /* Update struct */
+    if(buf_ptr) {
+        /* Allocate memory */
+        if(image_info.callbacks.image_malloc) {
+            if(NULL == (image_info.buffer = image_info.callbacks.image_malloc(buf_len,
+                    H5FD_FILE_IMAGE_OP_PROPERTY_LIST_SET, image_info.callbacks.udata)))
+                HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "image malloc callback failed")
+         } /* end if */
+         else
+            if(NULL == (image_info.buffer = H5MM_malloc(buf_len)))
+                HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "unable to allocate memory block")
+    
+        /* Copy data */
+        if(image_info.callbacks.image_memcpy) {
+            if(image_info.buffer != image_info.callbacks.image_memcpy(image_info.buffer, 
+                   buf_ptr, buf_len, H5FD_FILE_IMAGE_OP_PROPERTY_LIST_SET, 
+                   image_info.callbacks.udata))
+	        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTCOPY, FAIL, "image_memcpy callback failed")
+        } /* end if */
+	else
+            HDmemcpy(image_info.buffer, buf_ptr, buf_len);
+    } /* end if */
+    else
+        image_info.buffer = NULL;
+
+    image_info.size = buf_len;
+
+    /* Set values */
+    if(H5P_set(fapl, H5F_ACS_FILE_IMAGE_INFO_NAME, &image_info) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set file image info")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* end H5Pset_file_image() */
+
+
+/*-------------------------------------------------------------------------
+ * Function: H5Pget_file_image
+ *
+ * Purpose:     If the file image exists and buf_ptr_ptr is not NULL, 
+ *		allocate a buffer of the correct size, copy the image into 
+ *		the new buffer, and return the buffer to the caller in 
+ *		*buf_ptr_ptr.  Do this using the file image callbacks
+ *		if defined.  
+ *
+ *		NB: It is the responsibility of the caller to free the 
+ *		buffer whose address is returned in *buf_ptr_ptr.  Do
+ *		this using free if the file image callbacks are not 
+ *		defined, or with whatever method is appropriate if 
+ *		the callbacks are defined.
+ *
+ *              If buf_ptr_ptr is not NULL, and no image exists, set 
+ *		*buf_ptr_ptr to NULL.
+ *
+ *		If buf_len_ptr is not NULL, set *buf_len_ptr equal
+ *		to the length of the file image if it exists, and 
+ *		to 0 if it does not.
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Jacob Gruber
+ *              Thurday, August 11, 2011
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Pget_file_image(hid_t fapl_id, void **buf_ptr_ptr, size_t *buf_len_ptr)
+{
+    H5P_genplist_t *fapl;               /* Property list pointer */
+    H5FD_file_image_info_t image_info;  /* File image info */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE3("e", "i**x*z", fapl_id, buf_ptr_ptr, buf_len_ptr);
+
+    /* Get the plist structure */
+    if(NULL == (fapl = H5P_object_verify(fapl_id, H5P_FILE_ACCESS)))
+        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't find object for ID")
+
+    /* Get values */
+    if(H5P_get(fapl, H5F_ACS_FILE_IMAGE_INFO_NAME, &image_info) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get file image info")
+
+    /* verify file image field consistancy */
+    HDassert(((image_info.buffer != NULL) && (image_info.size > 0)) || 
+             ((image_info.buffer == NULL) && (image_info.size == 0)));
+
+    /* Set output size */
+    if(buf_len_ptr != NULL)
+        *buf_len_ptr = image_info.size;
+
+    /* Duplicate the image if desired, using callbacks if available */
+    if(buf_ptr_ptr != NULL) {
+        void * copy_ptr = NULL;         /* Copy of memory image */
+
+        if(image_info.buffer != NULL) {
+            /* Allocate memory */
+            if(image_info.callbacks.image_malloc) {
+                if(NULL == (copy_ptr = image_info.callbacks.image_malloc(image_info.size,
+                        H5FD_FILE_IMAGE_OP_PROPERTY_LIST_GET, image_info.callbacks.udata)))
+                    HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "image malloc callback failed")
+            } /* end if */
+            else
+                if(NULL == (copy_ptr = H5MM_malloc(image_info.size)))
+                    HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "unable to allocate copy")
+    
+            /* Copy data */
+            if(image_info.callbacks.image_memcpy) {
+                if(copy_ptr != image_info.callbacks.image_memcpy(copy_ptr, image_info.buffer,
+                        image_info.size, H5FD_FILE_IMAGE_OP_PROPERTY_LIST_GET, 
+                        image_info.callbacks.udata))
+                    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTCOPY, FAIL, "image_memcpy callback failed")
+            } /* end if */
+	    else
+                HDmemcpy(copy_ptr, image_info.buffer, image_info.size);
+        } /* end if */
+
+        *buf_ptr_ptr = copy_ptr;
+    } /* end if */
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* end H5Pget_file_image */
+
+
+/*-------------------------------------------------------------------------
+ * Function: H5Pset_file_image_callbacks
+ *
+ * Purpose:     Sets the callbacks for file images. Some file drivers allow
+ *              the use of user-defined callbacks for allocating, freeing and
+ *              copying the drivers internal buffer, potentially allowing a 
+ *              clever user to do optimizations such as avoiding large mallocs
+ *              and memcpys or to perform detailed logging.
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Jacob Gruber
+ *              Thurday, August 11, 2011
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Pset_file_image_callbacks(hid_t fapl_id, H5FD_file_image_callbacks_t *callbacks_ptr)
+{
+    H5P_genplist_t *fapl;               /* Property list pointer */
+    H5FD_file_image_info_t info;        /* File image info */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE2("e", "i*x", fapl_id, callbacks_ptr);
+
+    /* Get the plist structure */
+    if(NULL == (fapl = H5P_object_verify(fapl_id, H5P_FILE_ACCESS)))
+        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't find object for ID")
+
+    /* Get old info */
+    if(H5P_get(fapl, H5F_ACS_FILE_IMAGE_INFO_NAME, &info) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get old file image info")
+
+    /* verify file image field consistancy */
+    HDassert(((info.buffer != NULL) && (info.size > 0)) || 
+             ((info.buffer == NULL) && (info.size == 0)));
+
+    /* Make sure a file image hasn't already been set */
+    if(info.buffer != NULL || info.size > 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_SETDISALLOWED, FAIL, "setting callbacks when an image is already set is forbidden. It could cause memory leaks.")
+
+    /* verify that callbacks_ptr is not NULL */
+    if(NULL == callbacks_ptr)
+	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "NULL callbacks_ptr")
+
+    /* Make sure udata callbacks are going to be set if udata is going to be set */
+    if(callbacks_ptr->udata)
+        if(callbacks_ptr->udata_copy == NULL || callbacks_ptr->udata_free == NULL)
+            HGOTO_ERROR(H5E_PLIST, H5E_SETDISALLOWED, FAIL, "udata callbacks must be set if udata is set")
+
+    /* Release old udata if it exists */
+    if(info.callbacks.udata != NULL) {
+        HDassert(info.callbacks.udata_free);
+        if(info.callbacks.udata_free(info.callbacks.udata) < 0)
+	    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, FAIL, "udata_free callback failed")
+    } /* end if */
+
+    /* Update struct */
+    info.callbacks = *callbacks_ptr;
+
+    if(callbacks_ptr->udata) {
+        HDassert(callbacks_ptr->udata_copy);
+        HDassert(callbacks_ptr->udata_free);
+        if((info.callbacks.udata = callbacks_ptr->udata_copy(callbacks_ptr->udata)) == NULL)
+            HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't copy the suppplied udata")
+    } /* end if */
+
+    /* Set values */
+    if(H5P_set(fapl, H5F_ACS_FILE_IMAGE_INFO_NAME, &info) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't set file image info")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* end H5Pset_file_image_callbacks() */
+
+
+/*-------------------------------------------------------------------------
+ * Function: H5Pget_file_image_callbacks
+ *
+ * Purpose:     Sets the callbacks for file images. Some file drivers allow
+ *              the use of user-defined callbacks for allocating, freeing and
+ *              copying the drivers internal buffer, potentially allowing a 
+ *              clever user to do optimizations such as avoiding large mallocs
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Jacob Gruber
+ *              Thurday, August 11, 2011
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Pget_file_image_callbacks(hid_t fapl_id, H5FD_file_image_callbacks_t *callbacks_ptr)
+{
+    H5P_genplist_t *fapl;               /* Property list pointer */
+    H5FD_file_image_info_t info;        /* File image info */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_API(FAIL)
+    H5TRACE2("e", "i*x", fapl_id, callbacks_ptr);
+
+    /* Get the plist structure */
+    if(NULL == (fapl = H5P_object_verify(fapl_id, H5P_FILE_ACCESS)))
+        HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't find object for ID")
+
+    /* Get old info */
+    if(H5P_get(fapl, H5F_ACS_FILE_IMAGE_INFO_NAME, &info) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't get file image info")
+
+    /* verify file image field consistancy */
+    HDassert(((info.buffer != NULL) && (info.size > 0)) || 
+             ((info.buffer == NULL) && (info.size == 0)));
+
+    /* verify that callbacks_ptr is not NULL */
+    if(NULL == callbacks_ptr)
+	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "NULL callbacks_ptr")
+
+    /* Transfer values to parameters */
+    *callbacks_ptr = info.callbacks;
+
+    /* Copy udata if it exists */
+    if(info.callbacks.udata != NULL) {
+        HDassert(info.callbacks.udata_copy);
+        if((callbacks_ptr->udata = info.callbacks.udata_copy(info.callbacks.udata)) == 0)
+                HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "can't copy udata")
+    } /* end if */
+
+done:
+    FUNC_LEAVE_API(ret_value)
+} /* end H5Pget_file_image_callbacks() */
+
+
+/*-------------------------------------------------------------------------
+ * Function: H5P_file_image_info_del
+ *
+ * Purpose:     Delete callback for the file image info property, called
+ *              when the property is deleted from the plist. The buffer
+ *              and udata may need to be freed, possibly using their 
+ *              respective callbacks so the default free won't work.
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Jacob Gruber
+ *              Thurday, August 11, 2011
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5P_file_image_info_del(hid_t UNUSED prop_id, const char UNUSED *name, size_t UNUSED size, void *value)
+{
+    H5FD_file_image_info_t info;        /* Image info struct */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    if(value) {
+        info = *(H5FD_file_image_info_t *)value;
+
+        /* verify file image field consistancy */
+        HDassert(((info.buffer != NULL) && (info.size > 0)) || 
+                 ((info.buffer == NULL) && (info.size == 0)));
+
+        if(info.buffer && info.size > 0) {
+            /* Free buffer */
+            if(info.callbacks.image_free) {
+                if(info.callbacks.image_free(info.buffer, H5FD_FILE_IMAGE_OP_PROPERTY_LIST_CLOSE, info.callbacks.udata) < 0)
+		    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, FAIL, "image_free callback failed")
+            } /* end if */
+            else
+                free(info.buffer);
+        } /* end if */
+
+        /* Free udata if it exists */
+        if(info.callbacks.udata) {
+            if(NULL == info.callbacks.udata_free)
+                HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "udata_free not defined")
+
+            if(info.callbacks.udata_free(info.callbacks.udata) < 0)
+	        HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, FAIL, "udata_free callback failed")
+        } /* end if */
+    } /* end if */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5P_file_image_info_del() */
+
+
+/*-------------------------------------------------------------------------
+ * Function: H5P_file_image_info_copy
+ *
+ * Purpose:     Copy callback for the file image info property. The buffer
+ *              and udata may need to be copied, possibly using their 
+ *              respective callbacks so the default copy won't work.
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Jacob Gruber
+ *              Thurday, August 11, 2011
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5P_file_image_info_copy(const char UNUSED *name, size_t UNUSED size, void *value)
+{
+    H5FD_file_image_info_t *info;       /* Image info struct */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    if(value) {
+        info = (H5FD_file_image_info_t *)value;
+
+        /* verify file image field consistancy */
+        HDassert(((info->buffer != NULL) && (info->size > 0)) || 
+                 ((info->buffer == NULL) && (info->size == 0)));
+
+        if(info->buffer && info->size > 0) {
+            void *old_buffer;            /* Pointer to old image buffer */
+
+            /* Store the old buffer */
+            old_buffer = info->buffer;
+
+            /* Allocate new buffer */
+            if(info->callbacks.image_malloc) {
+                if(NULL == (info->buffer = info->callbacks.image_malloc(info->size,
+                        H5FD_FILE_IMAGE_OP_PROPERTY_LIST_COPY, info->callbacks.udata)))
+                    HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "image malloc callback failed")
+            } /* end if */
+            else {
+                if(NULL == (info->buffer = H5MM_malloc(info->size)))
+                    HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "unable to allocate memory block")
+            } /* end else */
+            
+            /* Copy data to new buffer */
+            if(info->callbacks.image_memcpy) {
+                if(info->buffer != info->callbacks.image_memcpy(info->buffer, old_buffer, 
+			info->size, H5FD_FILE_IMAGE_OP_PROPERTY_LIST_COPY, 
+			info->callbacks.udata))
+		    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTCOPY, FAIL, "image_memcpy callback failed")
+            } /* end if */
+	    else
+                HDmemcpy(info->buffer, old_buffer, info->size);
+        } /* end if */
+    } /* end if */
+
+    /* Copy udata if it exists */
+    if(info->callbacks.udata) {
+        void *old_udata = info->callbacks.udata;
+
+        if(NULL == info->callbacks.udata_copy)
+            HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "udata_copy not defined")
+
+        info->callbacks.udata = info->callbacks.udata_copy(old_udata);
+    } /* end if */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5P_file_image_info_copy() */
+
+
+/*-------------------------------------------------------------------------
+ * Function: H5P_file_image_info_close
+ *
+ * Purpose:     Close callback for the file image info property. The buffer
+ *              and udata may need to be freed, possibly using their 
+ *              respective callbacks so the standard free won't work.
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Jacob Gruber
+ *              Thurday, August 11, 2011
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5P_file_image_info_close(const char UNUSED *name, size_t UNUSED size, void *value)
+{
+    H5FD_file_image_info_t info;        /* Image info struct */
+    herr_t ret_value = SUCCEED;         /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    if(value) {
+        info = *(H5FD_file_image_info_t *)value;
+             
+        if(info.buffer != NULL && info.size > 0) { 
+            /* Free buffer */
+            if(info.callbacks.image_free) {
+                if(info.callbacks.image_free(info.buffer, H5FD_FILE_IMAGE_OP_PROPERTY_LIST_CLOSE,
+                        info.callbacks.udata) < 0)
+		    HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, FAIL, "image_free callback failed")
+            } /* end if */
+            else
+                H5MM_xfree(info.buffer);
+        } /* end if */
+    } /* end if */
+
+    /* Free udata if it exists */
+    if(info.callbacks.udata) {
+        if(NULL == info.callbacks.udata_free)
+            HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "udata_free not defined")
+        if(info.callbacks.udata_free(info.callbacks.udata) < 0)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTFREE, FAIL, "udata_free callback failed")
+    } /* end if */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5P_file_image_info_close() */
+
diff --git a/src/H5Pint.c b/src/H5Pint.c
index 08b8af6..46a06a0 100644
--- a/src/H5Pint.c
+++ b/src/H5Pint.c
@@ -51,6 +51,7 @@
 typedef struct {
     const H5P_genclass_t *parent;       /* Pointer to parent class */
     const char *name;                   /* Pointer to name to check */
+    H5P_genclass_t *new_class;          /* Pointer to class during path traversal */
 } H5P_check_class_t;
 
 
@@ -1358,11 +1359,11 @@ H5P_access_class(H5P_genclass_t *pclass, H5P_class_mod_t mod)
 
 /*--------------------------------------------------------------------------
  NAME
-    H5P_check_class
+    H5P_open_class_path_cb
  PURPOSE
     Internal callback routine to check for duplicated names in parent class.
  USAGE
-    int H5P_check_class(obj, id, key)
+    int H5P_open_class_path_cb(obj, id, key)
         H5P_genclass_t *obj;    IN: Pointer to class
         hid_t id;               IN: ID of object being looked at
         const void *key;        IN: Pointer to information used to compare
@@ -1378,27 +1379,29 @@ H5P_access_class(H5P_genclass_t *pclass, H5P_class_mod_t mod)
  REVISION LOG
 --------------------------------------------------------------------------*/
 static int
-H5P_check_class(void *_obj, hid_t UNUSED id, void *_key)
+H5P_open_class_path_cb(void *_obj, hid_t UNUSED id, void *_key)
 {
-    H5P_genclass_t *obj=(H5P_genclass_t *)_obj; /* Pointer to the class for this ID */
-    const H5P_check_class_t *key=(const H5P_check_class_t *)_key; /* Pointer to key information for comparison */
-    int ret_value=0;    /* Return value */
+    H5P_genclass_t *obj = (H5P_genclass_t *)_obj; /* Pointer to the class for this ID */
+    H5P_check_class_t *key = (H5P_check_class_t *)_key; /* Pointer to key information for comparison */
+    int ret_value = 0;    /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT_NOERR
 
     HDassert(obj);
-    HDassert(H5I_GENPROP_CLS==H5I_get_type(id));
+    HDassert(H5I_GENPROP_CLS == H5I_get_type(id));
     HDassert(key);
 
     /* Check if the class object has the same parent as the new class */
-    if(obj->parent==key->parent) {
+    if(obj->parent == key->parent) {
         /* Check if they have the same name */
-        if(HDstrcmp(obj->name,key->name)==0)
-            ret_value=1;        /* Indicate a match */
+        if(HDstrcmp(obj->name, key->name) == 0) {
+            key->new_class = obj;
+            ret_value = 1;        /* Indicate a match */
+        } /* end if */
     } /* end if */
 
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5P_check_class() */
+} /* end H5P_open_class_path_cb() */
 
 
 /*--------------------------------------------------------------------------
@@ -4555,8 +4558,8 @@ H5P_open_class_path(const char *path)
     char *curr_name;            /* Pointer to current component of path name */
     char *delimit;              /* Pointer to path delimiter during traversal */
     H5P_genclass_t *curr_class; /* Pointer to class during path traversal */
-    H5P_genclass_t *ret_value;  /* Return value */
     H5P_check_class_t check_info;   /* Structure to hold the information for checking duplicate names */
+    H5P_genclass_t *ret_value;  /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT
 
@@ -4569,20 +4572,24 @@ H5P_open_class_path(const char *path)
     /* Find the generic property class with this full path */
     curr_name = tmp_path;
     curr_class = NULL;
-    while((delimit=HDstrchr(curr_name,'/'))!=NULL) {
+    while(NULL != (delimit = HDstrchr(curr_name, '/'))) {
         /* Change the delimiter to terminate the string */
-        *delimit='\0';
+        *delimit = '\0';
 
         /* Set up the search structure */
-        check_info.parent=curr_class;
-        check_info.name=curr_name;
+        check_info.parent = curr_class;
+        check_info.name = curr_name;
+        check_info.new_class = NULL;
 
         /* Find the class with this name & parent by iterating over the open classes */
-        if(NULL == (curr_class = (H5P_genclass_t *)H5I_search(H5I_GENPROP_CLS, H5P_check_class, &check_info, FALSE)))
-            HGOTO_ERROR(H5E_PLIST, H5E_NOTFOUND, NULL, "can't locate class")
+        if(H5I_iterate(H5I_GENPROP_CLS, H5P_open_class_path_cb, &check_info, FALSE) < 0)
+	    HGOTO_ERROR(H5E_PLIST, H5E_BADITER, NULL, "can't iterate over classes")
+	else if(NULL == check_info.new_class)
+	    HGOTO_ERROR(H5E_PLIST, H5E_NOTFOUND, NULL, "can't locate class")
 
         /* Advance the pointer in the path to the start of the next component */
-        curr_name=delimit+1;
+        curr_class = check_info.new_class;
+        curr_name = delimit + 1;
     } /* end while */
 
     /* Should be pointing to the last component in the path name now... */
@@ -4590,13 +4597,16 @@ H5P_open_class_path(const char *path)
     /* Set up the search structure */
     check_info.parent = curr_class;
     check_info.name = curr_name;
+    check_info.new_class = NULL;
 
     /* Find the class with this name & parent by iterating over the open classes */
-    if(NULL == (curr_class = (H5P_genclass_t *)H5I_search(H5I_GENPROP_CLS, H5P_check_class, &check_info, FALSE)))
+    if(H5I_iterate(H5I_GENPROP_CLS, H5P_open_class_path_cb, &check_info, FALSE) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_BADITER, NULL, "can't iterate over classes")
+    else if(NULL == check_info.new_class)
         HGOTO_ERROR(H5E_PLIST, H5E_NOTFOUND, NULL, "can't locate class")
 
     /* Copy it */
-    if(NULL == (ret_value = H5P_copy_pclass(curr_class)))
+    if(NULL == (ret_value = H5P_copy_pclass(check_info.new_class)))
         HGOTO_ERROR(H5E_PLIST, H5E_CANTCOPY, NULL, "can't copy property class")
 
 done:
@@ -4604,7 +4614,7 @@ done:
     H5MM_xfree(tmp_path);
 
     FUNC_LEAVE_NOAPI(ret_value)
-}   /* H5P_open_class_path() */
+} /* H5P_open_class_path() */
 
 
 /*--------------------------------------------------------------------------
diff --git a/src/H5Pocpypl.c b/src/H5Pocpypl.c
index e61a0d7..1aceab2 100644
--- a/src/H5Pocpypl.c
+++ b/src/H5Pocpypl.c
@@ -469,6 +469,7 @@ H5Padd_merge_committed_dtype_path(hid_t plist_id, const char *path)
     herr_t ret_value = SUCCEED; /* Return value */
 
     FUNC_ENTER_API(FAIL)
+    H5TRACE2("e", "i*s", plist_id, path);
 
     /* Check parameters */
     if(!path)
@@ -528,6 +529,7 @@ H5Pfree_merge_committed_dtype_paths(hid_t plist_id)
     herr_t ret_value = SUCCEED; /* Return value */
 
     FUNC_ENTER_API(FAIL)
+    H5TRACE1("e", "i", plist_id);
 
     /* Get the plist structure */
     if(NULL == (plist = H5P_object_verify(plist_id, H5P_OBJECT_COPY)))
diff --git a/src/H5Ppublic.h b/src/H5Ppublic.h
index e33b685..c06ab39 100644
--- a/src/H5Ppublic.h
+++ b/src/H5Ppublic.h
@@ -323,6 +323,12 @@ H5_DLL herr_t H5Pget_libver_bounds(hid_t plist_id, H5F_libver_t *low,
     H5F_libver_t *high);
 H5_DLL herr_t H5Pset_elink_file_cache_size(hid_t plist_id, unsigned efc_size);
 H5_DLL herr_t H5Pget_elink_file_cache_size(hid_t plist_id, unsigned *efc_size);
+H5_DLL herr_t H5Pset_file_image(hid_t fapl_id, void *buf_ptr, size_t buf_len);
+H5_DLL herr_t H5Pget_file_image(hid_t fapl_id, void **buf_ptr_ptr, size_t *buf_len_ptr);
+H5_DLL herr_t H5Pset_file_image_callbacks(hid_t fapl_id,
+       H5FD_file_image_callbacks_t *callbacks_ptr);
+H5_DLL herr_t H5Pget_file_image_callbacks(hid_t fapl_id,
+       H5FD_file_image_callbacks_t *callbacks_ptr);
 
 /* Dataset creation property list (DCPL) routines */
 H5_DLL herr_t H5Pset_layout(hid_t plist_id, H5D_layout_t layout);
diff --git a/src/H5T.c b/src/H5T.c
index fcc4ab3..37d4b68 100644
--- a/src/H5T.c
+++ b/src/H5T.c
@@ -1449,7 +1449,8 @@ H5T_term_interface(void)
 	H5T_g.asoft = 0;
 
 	/* Unlock all datatypes, then free them */
-	H5I_search(H5I_DATATYPE, H5T_unlock_cb, NULL, FALSE);
+	/* note that we are ignoring the return value from H5I_iterate() */
+	H5I_iterate(H5I_DATATYPE, H5T_unlock_cb, NULL, FALSE);
 	H5I_dec_type_ref(H5I_DATATYPE);
 
         /* Reset all the datatype IDs */
diff --git a/src/H5err.txt b/src/H5err.txt
index 275a8ff..b61e8d0 100644
--- a/src/H5err.txt
+++ b/src/H5err.txt
@@ -214,6 +214,7 @@ MINOR, DSPACE, H5E_CANTCOMPARE, Can't compare objects
 MINOR, PLIST, H5E_CANTGET, Can't get value
 MINOR, PLIST, H5E_CANTSET, Can't set value
 MINOR, PLIST, H5E_DUPCLASS, Duplicate class name in parent class
+MINOR, PLIST, H5E_SETDISALLOWED, Disallowed operation
 
 # Link errors
 MINOR, LINK, H5E_TRAVERSE, Link traversal failure