Merge branch 'vol_integration_api' into json-vol

15 files changed, 795 insertions, 594 deletions

diff --git a/src/H5A.c b/src/H5A.c
index 5f548ad..55d5e27 100644
--- a/src/H5A.c
+++ b/src/H5A.c
@@ -460,7 +460,7 @@ done:
         const char *attr_name;  IN: Name of attribute to locate and open
         hid_t aapl_id;          IN: Attribute access property list
  RETURNS
-    ID of attribute on success, negative on failure
+    ID of attribute on success, H5I_INVALID_HID on failure
 
  DESCRIPTION
         This function opens an existing attribute for access.  The attribute
@@ -471,43 +471,49 @@ done:
 hid_t
 H5Aopen(hid_t loc_id, const char *attr_name, hid_t aapl_id)
 {
-    H5G_loc_t    	loc;            /* Object location */
-    H5A_t               *attr = NULL;   /* Attribute opened */
-    hid_t               dxpl_id  = H5AC_ind_read_dxpl_id; /* dxpl used by library */
-    hid_t		ret_value;
+    void *attr = NULL;                /* attr token from VOL plugin */
+    H5VL_object_t *obj = NULL;        /* object token of loc_id */
+    H5VL_loc_params_t loc_params; 
+    hid_t dxpl_id = H5AC_ind_read_dxpl_id; /* dxpl used by library */
+    hid_t ret_value = H5I_INVALID_HID;
 
-    FUNC_ENTER_API(FAIL)
+    FUNC_ENTER_API(H5I_INVALID_HID)
     H5TRACE3("i", "i*si", loc_id, attr_name, aapl_id);
 
-    /* check arguments */
-    if(H5I_ATTR == H5I_get_type(loc_id))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
-    if(H5G_loc(loc_id, &loc) < 0)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
-    if(!attr_name || !*attr_name)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no attribute name")
+    /* Check arguments */
+    if (H5I_ATTR == H5I_get_type(loc_id))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "location is not valid for an attribute")
+    if (!attr_name)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "name parameter cannot be NULL")
+    if (!*attr_name)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "name parameter cannot be an empty string")
 
     /* Verify access property list and get correct dxpl */
-    if(H5P_verify_apl_and_dxpl(&aapl_id, H5P_CLS_AACC, &dxpl_id, loc_id, FALSE) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
+    if (H5P_verify_apl_and_dxpl(&aapl_id, H5P_CLS_AACC, &dxpl_id, loc_id, FALSE) < 0)
+        HGOTO_ERROR(H5E_ATTR, H5E_CANTSET, H5I_INVALID_HID, "can't set access and transfer property lists")
 
-    /* Read in attribute from object header */
-    if(NULL == (attr = H5O_attr_open_by_name(loc.oloc, attr_name, dxpl_id)))
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, FAIL, "unable to load attribute info from object header for attribute: '%s'", attr_name)
+    /* Set location struct fields */
+    loc_params.type         = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type     = H5I_get_type(loc_id);
 
-    /* Finish initializing attribute */
-    if(H5A__open_common(&loc, attr) < 0)
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, FAIL, "unable to initialize attribute")
+    /* Get the location object */
+    if (NULL == (obj = H5VL_get_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid location identifier")
 
-    /* Register the attribute and get an ID for it */
-    if((ret_value = H5I_register(H5I_ATTR, attr, TRUE)) < 0)
-        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to register attribute for ID")
+    /* Open the attribute through the VOL */
+    if (NULL == (attr = H5VL_attr_open(obj->vol_obj, loc_params, obj->vol_info->vol_cls, 
+                                      attr_name, aapl_id, dxpl_id, H5_REQUEST_NULL)))
+        HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, H5I_INVALID_HID, "unable to open attribute")
+
+    /* Get an atom for the attribute */
+    if ((ret_value = H5VL_register_id(H5I_ATTR, attr, obj->vol_info, TRUE)) < 0)
+        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, H5I_INVALID_HID, "unable to atomize attribute handle")
 
 done:
     /* Cleanup on failure */
-    if(ret_value < 0)
-        if(attr && H5A_close(attr) < 0)
-            HDONE_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
+    if (H5I_INVALID_HID == ret_value)
+        if (attr && H5VL_attr_close(attr, obj->vol_info->vol_cls, dxpl_id, H5_REQUEST_NULL) < 0)
+            HDONE_ERROR(H5E_ATTR, H5E_CLOSEERROR, H5I_INVALID_HID, "unable to release attr")
 
     FUNC_LEAVE_API(ret_value)
 } /* H5Aopen() */
@@ -1490,22 +1496,32 @@ done:
 herr_t
 H5Adelete(hid_t loc_id, const char *name)
 {
-    H5G_loc_t	loc;		        /* Object location */
-    herr_t	ret_value = SUCCEED;    /* Return value */
+    H5VL_object_t      *obj = NULL;
+    H5VL_loc_params_t   loc_params;
+    herr_t	            ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE2("e", "i*s", loc_id, name);
 
-    /* check arguments */
-    if(H5I_ATTR == H5I_get_type(loc_id))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
-    if(H5G_loc(loc_id, &loc) < 0)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
-    if(!name || !*name)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name")
+    /* Check arguments */
+    if (H5I_ATTR == H5I_get_type(loc_id))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "location is not valid for an attribute")
+    if (!name)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "name parameter cannot be NULL")
+    if (!*name)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "name parameter cannot be an empty string")
 
-    /* Delete the attribute from the location */
-    if(H5O_attr_remove(loc.oloc, name, H5AC_ind_read_dxpl_id) < 0)
+    /* Fill in location struct fields */
+    loc_params.type         = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type     = H5I_get_type(loc_id);
+
+    /* Get the object */
+    if (NULL == (obj = H5VL_get_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid object identifier")
+
+    /* Delete the attribute through the VOL */
+    if ((ret_value = H5VL_attr_specific(obj->vol_obj, loc_params, obj->vol_info->vol_cls, H5VL_ATTR_DELETE,
+                                       H5AC_ind_read_dxpl_id, H5_REQUEST_NULL, name)) < 0)
         HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete attribute")
 
 done:
diff --git a/src/H5F.c b/src/H5F.c
index 860ed06..12285bb 100644
--- a/src/H5F.c
+++ b/src/H5F.c
@@ -1041,24 +1041,26 @@ done:
  * Return:      Success:    Bytes copied / number of bytes needed
  *
  *              Failure:    -1
+ *
  *-------------------------------------------------------------------------
  */
 ssize_t
 H5Fget_file_image(hid_t file_id, void *buf_ptr, size_t buf_len)
 {
-    H5F_t      *file;                   /* File object for file ID */
-    ssize_t     ret_value;              /* Return value */
+    H5VL_object_t  *file;           /* File object for file ID  */
+    ssize_t         ret_value;      /* Return value             */
 
     FUNC_ENTER_API((-1))
     H5TRACE3("Zs", "i*xz", file_id, buf_ptr, buf_len);
 
     /* Check args */
-    if (NULL == (file = (H5F_t *)H5I_object_verify(file_id, H5I_FILE)))
+    if (NULL == (file = (H5VL_object_t *)H5I_object_verify(file_id, H5I_FILE)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, (-1), "not a file ID")
 
-    /* call private get_file_image function */
-    if ((ret_value = H5F_get_file_image(file, buf_ptr, buf_len, H5AC_ind_read_dxpl_id, H5AC_rawdata_dxpl_id)) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTGET, (-1), "unable to get file image")
+    /* Get image through the VOL */
+    if (H5VL_file_optional(file->vol_obj, file->vol_info->vol_cls, H5AC_ind_read_dxpl_id, H5_REQUEST_NULL, 
+                          H5VL_FILE_GET_FILE_IMAGE, buf_ptr, &ret_value, buf_len) < 0)
+        HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, (-1), "unable to get file image")
 
 done:
     FUNC_LEAVE_API(ret_value)
diff --git a/src/H5Fpkg.h b/src/H5Fpkg.h
index 82b0997..0b72376 100644
--- a/src/H5Fpkg.h
+++ b/src/H5Fpkg.h
@@ -402,6 +402,7 @@ typedef struct {
 } H5F_trav_obj_cnt_t;
 
 /* User data for traversal routine to get ID lists */
+/* XXX: Type of obj_count and max_objs should be identical! */
 typedef struct {
     size_t max_objs;
     hid_t *oid_list;
diff --git a/src/H5G.c b/src/H5G.c
index 74e2048..c2ba13b 100644
--- a/src/H5G.c
+++ b/src/H5G.c
@@ -384,9 +384,9 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Gcreate_anon
+ * Function:    H5Gcreate_anon
  *
- * Purpose:	Creates a new group relative to LOC_ID, giving it the
+ * Purpose:     Creates a new group relative to LOC_ID, giving it the
  *              specified creation property list GCPL_ID and access
  *              property list GAPL_ID.
  *
@@ -402,78 +402,63 @@ done:
  *                  hid_t gcpl_id;	  IN: Property list for group creation
  *                  hid_t gapl_id;	  IN: Property list for group access
  *
- * Example:	To create missing groups "A" and "B01" along the given path "/A/B01/grp"
+ * Example:     To create missing groups "A" and "B01" along the given path "/A/B01/grp"
  *              hid_t create_id = H5Pcreate(H5P_GROUP_CREATE);
  *              int   status = H5Pset_create_intermediate_group(create_id, TRUE);
  *              hid_t gid = H5Gcreate_anon(file_id, "/A/B01/grp", create_id, H5P_DEFAULT);
  *
- * Return:	Success:	The object ID of a new, empty group open for
- *				writing.  Call H5Gclose() when finished with
- *				the group.
- *
- *		Failure:	FAIL
+ * Return:      Success:    The object ID of a new, empty group open for
+ *                          writing. Call H5Gclose() when finished with
+ *                          the group.
  *
- * Programmer:  Peter Cao
- *	        May 08, 2005
+ *              Failure:    H5I_INVALID_HID
  *
  *-------------------------------------------------------------------------
  */
 hid_t
 H5Gcreate_anon(hid_t loc_id, hid_t gcpl_id, hid_t gapl_id)
 {
-    H5G_loc_t	    loc;
-    H5G_t	   *grp = NULL;
-    H5G_obj_create_t gcrt_info;         /* Information for group creation */
-    hid_t           dxpl_id = H5AC_ind_read_dxpl_id; /* dxpl used by library */
-    hid_t	    ret_value;
+    void *grp = NULL;                   /* group token from VOL plugin */
+    H5VL_object_t *obj = NULL;          /* object token of loc_id */
+    H5VL_loc_params_t loc_params;
+    hid_t dxpl_id = H5AC_ind_read_dxpl_id; /* dxpl used by library */
+    hid_t ret_value = H5I_INVALID_HID;                    /* Return value */
 
-    FUNC_ENTER_API(FAIL)
+    FUNC_ENTER_API(H5I_INVALID_HID)
     H5TRACE3("i", "iii", loc_id, gcpl_id, gapl_id);
 
-    /* Check arguments */
-    if(H5G_loc(loc_id, &loc) < 0)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
-
     /* Check group creation property list */
-    if(H5P_DEFAULT == gcpl_id)
+    if (H5P_DEFAULT == gcpl_id)
         gcpl_id = H5P_GROUP_CREATE_DEFAULT;
     else
-        if(TRUE != H5P_isa_class(gcpl_id, H5P_GROUP_CREATE))
-            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not group create property list")
+        if (TRUE != H5P_isa_class(gcpl_id, H5P_GROUP_CREATE))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not group create property list")
 
     /* Verify access property list and get correct dxpl */
-    if(H5P_verify_apl_and_dxpl(&gapl_id, H5P_CLS_GACC, &dxpl_id, loc_id, TRUE) < 0)
-        HGOTO_ERROR(H5E_SYM, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
-
-    /* Set up group creation info */
-    gcrt_info.gcpl_id = gcpl_id;
-    gcrt_info.cache_type = H5G_NOTHING_CACHED;
-    HDmemset(&gcrt_info.cache, 0, sizeof(gcrt_info.cache));
+    if (H5P_verify_apl_and_dxpl(&gapl_id, H5P_CLS_GACC, &dxpl_id, loc_id, TRUE) < 0)
+        HGOTO_ERROR(H5E_SYM, H5E_CANTSET, H5I_INVALID_HID, "can't set access and transfer property lists")
 
-    /* Create the new group & get its ID */
-    if(NULL == (grp = H5G__create(loc.oloc->file, &gcrt_info, dxpl_id)))
-        HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create group")
-    if((ret_value = H5I_register(H5I_GROUP, grp, TRUE)) < 0)
-	HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to register group")
+    /* Set location struct fields */
+    loc_params.type         = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type     = H5I_get_type(loc_id);
 
-done:
-    /* Release the group's object header, if it was created */
-    if(grp) {
-        H5O_loc_t *oloc;         /* Object location for group */
+    /* get the location object */
+    if (NULL == (obj = (H5VL_object_t *)H5I_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid location identifier")
 
-        /* Get the new group's object location */
-        if(NULL == (oloc = H5G_oloc(grp)))
-            HDONE_ERROR(H5E_SYM, H5E_CANTGET, FAIL, "unable to get object location of group")
+    /* Create the group through the VOL */
+    if (NULL == (grp = H5VL_group_create(obj->vol_obj, loc_params, obj->vol_info->vol_cls, NULL, 
+                                        gcpl_id, gapl_id, dxpl_id, H5_REQUEST_NULL)))
+        HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, H5I_INVALID_HID, "unable to create group")
 
-        /* Decrement refcount on group's object header in memory */
-        if(H5O_dec_rc_by_loc(oloc, dxpl_id) < 0)
-           HDONE_ERROR(H5E_SYM, H5E_CANTDEC, FAIL, "unable to decrement refcount on newly created object")
-    } /* end if */
+    /* Get an atom for the group */
+    if ((ret_value = H5VL_register_id(H5I_GROUP, grp, obj->vol_info, TRUE)) < 0)
+        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, H5I_INVALID_HID, "unable to atomize group handle")
 
-    /* Cleanup on failure */
-    if(ret_value < 0)
-        if(grp && H5G_close(grp) < 0)
-            HDONE_ERROR(H5E_SYM, H5E_CLOSEERROR, FAIL, "unable to release group")
+done:
+    if (H5I_INVALID_HID == ret_value)
+        if (grp && H5VL_group_close(grp, obj->vol_info->vol_cls, dxpl_id, H5_REQUEST_NULL) < 0)
+            HDONE_ERROR(H5E_SYM, H5E_CLOSEERROR, H5I_INVALID_HID, "unable to release group")
 
     FUNC_LEAVE_API(ret_value)
 } /* end H5Gcreate_anon() */
diff --git a/src/H5I.c b/src/H5I.c
index 448e3df..7f3274a 100644
--- a/src/H5I.c
+++ b/src/H5I.c
@@ -1886,7 +1886,7 @@ static herr_t
 H5I__iterate_pub_cb(void H5_ATTR_UNUSED *obj, hid_t id, void *_udata)
 {
     H5I_iterate_pub_ud_t *udata = (H5I_iterate_pub_ud_t *)_udata; /* User data for callback */
-    herr_t ret_value;   /* Callback return value */
+    herr_t ret_value = FAIL;   /* Callback return value */
 
     FUNC_ENTER_NOAPI_NOINIT_NOERR
 
@@ -1965,16 +1965,24 @@ H5I__iterate_cb(void *_item, void H5_ATTR_UNUSED *_key, void *_udata)
     FUNC_ENTER_STATIC_NOERR
 
     /* Don't make callback if app_ref is set and the appl. ref count is 0 */
-    if((!udata->app_ref) || (item->app_count > 0)) {
-        herr_t cb_ret_val;
+    if ((!udata->app_ref) || (item->app_count > 0)) {
+        H5I_type_t type = udata->obj_type;
+        const void *obj_ptr = NULL;
+
+        if (H5I_FILE == type || H5I_GROUP == type || H5I_DATASET == type || H5I_ATTR == type) {
+            const H5VL_object_t *obj = (const H5VL_object_t *)item->obj_ptr;
+            obj_ptr = obj->vol_obj;
+        }
+        else if (H5I_DATATYPE == type) {
+            const H5T_t *dt = (const H5T_t *)item->obj_ptr;
+            obj_ptr = (void *)H5T_get_actual_type(dt);
+        }
+        else
+            obj_ptr = item->obj_ptr;
 
         /* (Casting away const OK) */
-        cb_ret_val = (*udata->user_func)((void *)item->obj_ptr, item->id, udata->user_udata);
-        if(cb_ret_val > 0)
-            ret_value = H5_ITER_STOP;	/* terminate iteration early */
-        else if(cb_ret_val < 0)
-            ret_value = H5_ITER_ERROR;  /* indicate failure (which terminates iteration) */
-    } /* end if */
+        ret_value = (*udata->user_func)((void *)obj_ptr, item->id, udata->user_udata);
+    }
 
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5I__iterate_cb() */
@@ -2008,8 +2016,8 @@ H5I__iterate_cb(void *_item, void H5_ATTR_UNUSED *_key, void *_udata)
 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	*/
-    herr_t	   ret_value = SUCCEED;	/*return value		*/
+    H5I_id_type_t *type_ptr;            /* Pointer to the type  */
+    herr_t	   ret_value = SUCCEED;     /* Return value         */
 
     FUNC_ENTER_NOAPI(FAIL)
 
@@ -2024,9 +2032,9 @@ H5I_iterate(H5I_type_t type, H5I_search_func_t func, void *udata, hbool_t app_re
         herr_t iter_status;             /* Iteration status */
 
         /* Set up iterator user data */
-        iter_udata.user_func = func;
-        iter_udata.user_udata = udata;
-        iter_udata.app_ref = app_ref;
+        iter_udata.user_func    = func;
+        iter_udata.user_udata   = udata;
+        iter_udata.app_ref      = app_ref;
 
         /* Iterate over IDs */
         if ((iter_status = H5SL_iterate(type_ptr->ids, H5I__iterate_cb, &iter_udata)) < 0)
@@ -2134,66 +2142,49 @@ done:
 hid_t
 H5Iget_file_id(hid_t obj_id)
 {
-    hid_t ret_value = H5I_INVALID_HID;          /* Return value */
+    H5VL_object_t  *obj;
+    void           *file        = NULL;
+    H5I_type_t      type;                           /* ID type */
+    hid_t           ret_value   = H5I_INVALID_HID;  /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE1("i", "i", obj_id);
 
-    if ((ret_value = H5I_get_file_id(obj_id, TRUE)) < 0)
-        HGOTO_ERROR(H5E_ATOM, H5E_CANTGET, H5I_INVALID_HID, "can't retrieve file ID")
-
-done:
-    FUNC_LEAVE_API(ret_value)
-} /* end H5Iget_file_id() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5I_get_file_id
- *
- * Purpose:     The private version of H5Iget_file_id(), obtains the file
- *              ID given an object ID.
- *
- * Return:      Success:    The file ID associated with the object
- *
- *              Failure:	H5I_INVALID_HID
- *
- *-------------------------------------------------------------------------
- */
-hid_t
-H5I_get_file_id(hid_t obj_id, hbool_t app_ref)
-{
-    H5I_type_t  type;                           /* ID type                  */
-    hid_t       ret_value = H5I_INVALID_HID;    /* Return value             */
-
-    FUNC_ENTER_NOAPI_NOINIT
-
     /* Get object type */
     type = H5I_TYPE(obj_id);
-    if (type == H5I_FILE) {
-        /* Increment reference count on file ID */
-        if(H5I_inc_ref(obj_id, app_ref) < 0)
-            HGOTO_ERROR(H5E_ATOM, H5E_CANTSET, H5I_INVALID_HID, "incrementing file ID failed")
-
-        /* Set return value */
-        ret_value = obj_id;
-    }
-    else if (type == H5I_DATATYPE || type == H5I_GROUP || type == H5I_DATASET || type == H5I_ATTR) {
-        H5G_loc_t loc;              /* Location of object */
 
-        /* Get the object location information */
-        if(H5G_loc(obj_id, &loc) < 0)
-            HGOTO_ERROR(H5E_ATOM, H5E_CANTGET, H5I_INVALID_HID, "can't get object location")
-
-        /* Get the file ID for the object */
-        if((ret_value = H5F_get_id(loc.oloc->file, app_ref)) < 0)
-            HGOTO_ERROR(H5E_ATOM, H5E_CANTGET, H5I_INVALID_HID, "can't get file ID")
+    if(H5I_FILE == type || H5I_DATATYPE == type || H5I_GROUP == type || 
+       H5I_DATASET == type || H5I_ATTR == type) {
+        /* Get the object pointer*/
+        if (NULL == (obj = H5VL_get_object(obj_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid identifier")
+
+        /* Get the file through the VOL */
+        if (H5VL_file_get(obj->vol_obj, obj->vol_info->vol_cls, H5VL_OBJECT_GET_FILE, 
+                         H5AC_ind_read_dxpl_id, H5_REQUEST_NULL, type, &file) < 0)
+            HGOTO_ERROR(H5E_INTERNAL, H5E_CANTINIT, H5I_INVALID_HID, "unable to get file")
+
+        if (NULL == file)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, H5I_INVALID_HID, "unable to reopen file")
+
+        /* Check if the ID already exists and procceed accordingly */
+        if (FAIL == (ret_value = H5I_get_id(file, H5I_FILE))) {
+            /* Get an atom for the file */
+            if ((ret_value = H5VL_register_id(H5I_FILE, file, obj->vol_info, TRUE)) < 0)
+                HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, H5I_INVALID_HID, "unable to atomize file handle")
+        }
+        else {
+            /* Increment ref count on existing ID */
+            if (H5I_inc_ref(ret_value, TRUE) < 0)
+                HGOTO_ERROR(H5E_ATOM, H5E_CANTSET, H5I_INVALID_HID, "incrementing file ID failed")
+        }
     }
     else
         HGOTO_ERROR(H5E_ARGS, H5E_BADRANGE, H5I_INVALID_HID, "invalid object ID")
 
 done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5I_get_file_id() */
+    FUNC_LEAVE_API(ret_value)
+} /* end H5Iget_file_id() */
 
 
 /*-------------------------------------------------------------------------
diff --git a/src/H5Iprivate.h b/src/H5Iprivate.h
index 04160aa..3d0d03a 100644
--- a/src/H5Iprivate.h
+++ b/src/H5Iprivate.h
@@ -72,7 +72,6 @@ H5_DLL void *H5I_subst(hid_t id, const void *new_object);
 H5_DLL void *H5I_object(hid_t id);
 H5_DLL void *H5I_object_verify(hid_t id, H5I_type_t id_type);
 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 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);
diff --git a/src/H5L.c b/src/H5L.c
index 4c2f225..5cae026 100644
--- a/src/H5L.c
+++ b/src/H5L.c
@@ -33,6 +33,7 @@
 #include "H5Oprivate.h"         /* File objects                             */
 #include "H5Pprivate.h"         /* Property lists                           */
 #include "H5VLprivate.h"        /* Virtual Object Layer                     */
+#include "H5VLnative.h"         /* Virtual Object Layer (native)            */
 
 
 /****************/
@@ -264,19 +265,16 @@ H5L_term_package(void)
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Lmove
+ * Function:    H5Lmove
  *
- * Purpose:	Renames an object within an HDF5 file and moves it to a new
+ * Purpose:     Renames an object within an HDF5 file and moves it to a new
  *              group.  The original name SRC is unlinked from the group graph
  *              and then inserted with the new name DST (which can specify a
  *              new path for the object) as an atomic operation. The names
- *              are interpreted relative to SRC_LOC_ID and
- *              DST_LOC_ID, which are either file IDs or group ID.
+ *              are interpreted relative to SRC_LOC_ID and DST_LOC_ID,
+ *              which are either file IDs or group ID.
  *
- * Return:	Non-negative on success/Negative on failure
- *
- * Programmer:	James Laird
- *              Wednesday, March 29, 2006
+ * Return:      SUCCEED/FAIL
  *
  *-------------------------------------------------------------------------
  */
@@ -284,47 +282,72 @@ herr_t
 H5Lmove(hid_t src_loc_id, const char *src_name, hid_t dst_loc_id,
     const char *dst_name, hid_t lcpl_id, hid_t lapl_id)
 {
-    H5G_loc_t	src_loc, *src_loc_p;
-    H5G_loc_t	dst_loc, *dst_loc_p;
-    hid_t       dxpl_id = H5AC_ind_read_dxpl_id;         /* dxpl used by library */
-    herr_t      ret_value=SUCCEED;              /* Return value */
+    H5VL_object_t      *obj1            = NULL;         /* Object token of src_id */
+    H5VL_loc_params_t   loc_params1;
+    H5VL_object_t      *obj2            = NULL;         /* Object token of dst_id */
+    H5VL_loc_params_t   loc_params2;
+    hid_t               dxpl_id         = H5AC_ind_read_dxpl_id;    /* dxpl used by library */
+    herr_t              ret_value       = SUCCEED;      /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE6("e", "i*si*sii", src_loc_id, src_name, dst_loc_id, dst_name, lcpl_id,
              lapl_id);
 
     /* Check arguments */
-    if(src_loc_id == H5L_SAME_LOC && dst_loc_id == H5L_SAME_LOC)
+    if (src_loc_id == H5L_SAME_LOC && dst_loc_id == H5L_SAME_LOC)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "source and destination should not both be H5L_SAME_LOC")
-    if(src_loc_id != H5L_SAME_LOC && H5G_loc(src_loc_id, &src_loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
-    if(dst_loc_id != H5L_SAME_LOC && H5G_loc(dst_loc_id, &dst_loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
-    if(!src_name || !*src_name)
+    if (!src_name || !*src_name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no current name specified")
-    if(!dst_name || !*dst_name)
+    if (!dst_name || !*dst_name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no destination name specified")
-    if(lcpl_id != H5P_DEFAULT && (TRUE != H5P_isa_class(lcpl_id, H5P_LINK_CREATE)))
+    if (lcpl_id != H5P_DEFAULT && (TRUE != H5P_isa_class(lcpl_id, H5P_LINK_CREATE)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a link creation property list")
 
+    /* Check the link create property list */
+    if (H5P_DEFAULT == lcpl_id)
+        lcpl_id = H5P_LINK_CREATE_DEFAULT;
+
     /* Verify access property list and get correct dxpl */
-    if(H5P_verify_apl_and_dxpl(&lapl_id, H5P_CLS_LACC, &dxpl_id,
+    if (H5P_verify_apl_and_dxpl(&lapl_id, H5P_CLS_LACC, &dxpl_id,
                                ((src_loc_id != H5L_SAME_LOC) ? src_loc_id : dst_loc_id),
                                TRUE) < 0)
         HGOTO_ERROR(H5E_LINK, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
 
-    /* Set up src & dst location pointers */
-    src_loc_p = &src_loc;
-    dst_loc_p = &dst_loc;
-    if(src_loc_id == H5L_SAME_LOC)
-        src_loc_p = dst_loc_p;
-    else if(dst_loc_id == H5L_SAME_LOC)
-        dst_loc_p = src_loc_p;
+    /* Set location paramter for source object */
+    loc_params1.type                            = H5VL_OBJECT_BY_NAME;
+    loc_params1.loc_data.loc_by_name.name       = src_name;
+    loc_params1.loc_data.loc_by_name.lapl_id    = lapl_id;
+    loc_params1.obj_type                        = H5I_get_type(src_loc_id);
+
+    /* Set location paramter for destination object */
+    loc_params2.type                            = H5VL_OBJECT_BY_NAME;
+    loc_params2.loc_data.loc_by_name.name       = dst_name;
+    loc_params2.loc_data.loc_by_name.lapl_id    = lapl_id;
+    loc_params2.obj_type                        = H5I_get_type(dst_loc_id);
 
-    /* Move the link */
-    if(H5L_move(src_loc_p, src_name, dst_loc_p, dst_name, FALSE, lcpl_id,
-            lapl_id, dxpl_id) < 0)
-	HGOTO_ERROR(H5E_LINK, H5E_CANTMOVE, FAIL, "unable to move link")
+    if (H5L_SAME_LOC != src_loc_id) {
+        /* Get the location object */
+        if (NULL == (obj1 = (H5VL_object_t *)H5I_object(src_loc_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+    }
+    if (H5L_SAME_LOC != dst_loc_id) {
+        /* Get the location object */
+        if (NULL == (obj2 = (H5VL_object_t *)H5I_object(dst_loc_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+    }
+
+    /* Make sure that the VOL plugins are the same */
+    if (obj1 && obj2) {
+        if (obj1->vol_info->vol_cls->value != obj2->vol_info->vol_cls->value)
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "Objects are accessed through different VOL plugins and can't be linked")
+    }
+
+    /* Move the link through the VOL */
+    if (H5VL_link_move((obj1 ? obj1->vol_obj : NULL), loc_params1, 
+                      (obj2 ? obj2->vol_obj : NULL), loc_params2, 
+                      (obj1 ? obj1->vol_info->vol_cls : obj2->vol_info->vol_cls),
+                      lcpl_id, lapl_id, dxpl_id, H5_REQUEST_NULL) < 0)
+        HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create link")
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -332,16 +355,13 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Lcopy
+ * Function:    H5Lcopy
  *
- * Purpose:	Creates an identical copy of a link with the same creation
+ * Purpose:     Creates an identical copy of a link with the same creation
  *              time and target.  The new link can have a different name
  *              and be in a different location than the original.
  *
- * Return:	Non-negative on success/Negative on failure
- *
- * Programmer:	James Laird
- *              Wednesday, March 29, 2006
+ * Return:      SUCCEED/FAIL
  *
  *-------------------------------------------------------------------------
  */
@@ -349,47 +369,72 @@ herr_t
 H5Lcopy(hid_t src_loc_id, const char *src_name, hid_t dst_loc_id,
     const char *dst_name, hid_t lcpl_id, hid_t lapl_id)
 {
-    H5G_loc_t	src_loc, *src_loc_p;
-    H5G_loc_t	dst_loc, *dst_loc_p;
-    hid_t       dxpl_id = H5AC_ind_read_dxpl_id;         /* dxpl used by library */
-    herr_t      ret_value=SUCCEED;              /* Return value */
+    H5VL_object_t      *obj1            = NULL;         /* Object token of src_id */
+    H5VL_loc_params_t   loc_params1;
+    H5VL_object_t      *obj2            = NULL;         /* Object token of dst_id */
+    H5VL_loc_params_t   loc_params2;
+    hid_t               dxpl_id         = H5AC_ind_read_dxpl_id;    /* dxpl used by library */
+    herr_t              ret_value       = SUCCEED;      /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE6("e", "i*si*sii", src_loc_id, src_name, dst_loc_id, dst_name, lcpl_id,
              lapl_id);
 
     /* Check arguments */
-    if(src_loc_id == H5L_SAME_LOC && dst_loc_id == H5L_SAME_LOC)
+    if (src_loc_id == H5L_SAME_LOC && dst_loc_id == H5L_SAME_LOC)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "source and destination should not both be H5L_SAME_LOC")
-    if(src_loc_id != H5L_SAME_LOC && H5G_loc(src_loc_id, &src_loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
-    if(dst_loc_id != H5L_SAME_LOC && H5G_loc(dst_loc_id, &dst_loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
-    if(!src_name || !*src_name)
+    if (!src_name || !*src_name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no current name specified")
-    if(!dst_name || !*dst_name)
+    if (!dst_name || !*dst_name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no destination name specified")
-    if(lcpl_id != H5P_DEFAULT && (TRUE != H5P_isa_class(lcpl_id, H5P_LINK_CREATE)))
+    if (lcpl_id != H5P_DEFAULT && (TRUE != H5P_isa_class(lcpl_id, H5P_LINK_CREATE)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a link creation property list")
 
+    /* Check the link create property list */
+    if (H5P_DEFAULT == lcpl_id)
+        lcpl_id = H5P_LINK_CREATE_DEFAULT;
+
     /* Verify access property list and get correct dxpl */
-    if(H5P_verify_apl_and_dxpl(&lapl_id, H5P_CLS_LACC, &dxpl_id,
+    if (H5P_verify_apl_and_dxpl(&lapl_id, H5P_CLS_LACC, &dxpl_id,
                                ((src_loc_id != H5L_SAME_LOC) ? src_loc_id : dst_loc_id),
                                TRUE) < 0)
         HGOTO_ERROR(H5E_LINK, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
 
-    /* Set up src & dst location pointers */
-    src_loc_p = &src_loc;
-    dst_loc_p = &dst_loc;
-    if(src_loc_id == H5L_SAME_LOC)
-        src_loc_p = dst_loc_p;
-    else if(dst_loc_id == H5L_SAME_LOC)
-        dst_loc_p = src_loc_p;
+    /* Set location paramter for source object */
+    loc_params1.type                            = H5VL_OBJECT_BY_NAME;
+    loc_params1.loc_data.loc_by_name.name       = src_name;
+    loc_params1.loc_data.loc_by_name.lapl_id    = lapl_id;
+    loc_params1.obj_type                        = H5I_get_type(src_loc_id);
+
+    /* Set location paramter for destination object */
+    loc_params2.type                            = H5VL_OBJECT_BY_NAME;
+    loc_params2.loc_data.loc_by_name.name       = dst_name;
+    loc_params2.loc_data.loc_by_name.lapl_id    = lapl_id;
+    loc_params2.obj_type                        = H5I_get_type(dst_loc_id);
 
-    /* Copy the link */
-    if(H5L_move(src_loc_p, src_name, dst_loc_p, dst_name, TRUE, lcpl_id,
-                lapl_id, dxpl_id) < 0)
-	HGOTO_ERROR(H5E_LINK, H5E_CANTMOVE, FAIL, "unable to move link")
+    if (H5L_SAME_LOC != src_loc_id) {
+        /* Get the location object */
+        if (NULL == (obj1 = (H5VL_object_t *)H5I_object(src_loc_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+    }
+    if (H5L_SAME_LOC != dst_loc_id) {
+        /* Get the location object */
+        if (NULL == (obj2 = (H5VL_object_t *)H5I_object(dst_loc_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+    }
+
+    /* Make sure that the VOL plugins are the same */
+    if (obj1 && obj2) {
+        if (obj1->vol_info->vol_cls->value != obj2->vol_info->vol_cls->value)
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "Objects are accessed through different VOL plugins and can't be linked")
+    }
+
+    /* Move the link through the VOL */
+    if (H5VL_link_copy((obj1 ? obj1->vol_obj : NULL), loc_params1, 
+                      (obj2 ? obj2->vol_obj : NULL), loc_params2, 
+                      (obj1 ? obj1->vol_info->vol_cls : obj2->vol_info->vol_cls),
+                      lcpl_id, lapl_id, dxpl_id, H5_REQUEST_NULL) < 0)
+        HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create link")
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -1842,7 +1887,7 @@ H5L_link_cb(H5G_loc_t *grp_loc/*in*/, const char *name, const H5O_link_t H5_ATTR
             /* Set up location for user-defined callback */
             if((grp = H5G_open(&temp_loc, udata->dxpl_id)) == NULL)
                 HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open group")
-            if((grp_id = H5I_register(H5I_GROUP, grp, TRUE)) < 0)
+            if((grp_id = H5VL_native_register(H5I_GROUP, grp, TRUE)) < 0)
                 HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to register ID for group")
 
             /* Make callback */
@@ -2553,7 +2598,7 @@ H5L_move_dest_cb(H5G_loc_t *grp_loc/*in*/, const char *name,
             /* Set up location for user-defined callback */
             if((grp = H5G_open(&temp_loc, udata->dxpl_id)) == NULL)
                 HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, FAIL, "unable to open group")
-            if((grp_id = H5I_register(H5I_GROUP, grp, TRUE)) < 0)
+            if((grp_id = H5VL_native_register(H5I_GROUP, grp, TRUE)) < 0)
                 HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to register group ID")
 
             if(udata->copy) {
diff --git a/src/H5O.c b/src/H5O.c
index d98be2f..525a115 100644
--- a/src/H5O.c
+++ b/src/H5O.c
@@ -75,9 +75,9 @@
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Oopen
+ * Function:    H5Oopen
  *
- * Purpose:	Opens an object within an HDF5 file.
+ * Purpose:     Opens an object within an HDF5 file.
  *
  *              This function opens an object in the same way that H5Gopen2,
  *              H5Topen2, and H5Dopen2 do. However, H5Oopen doesn't require
@@ -88,38 +88,53 @@
  *              The opened object should be closed again with H5Oclose
  *              or H5Gclose, H5Tclose, or H5Dclose.
  *
- * Return:	Success:	An open object identifier
- *		Failure:	Negative
+ * Return:      Success:    An open object identifier
  *
- * Programmer:	James Laird
- *		July 14 2006
+ *              Failure:    H5I_INVALID_HID
  *
  *-------------------------------------------------------------------------
  */
 hid_t
 H5Oopen(hid_t loc_id, const char *name, hid_t lapl_id)
 {
-    H5G_loc_t	loc;
-    hid_t       dxpl_id = H5AC_ind_read_dxpl_id; /* dxpl used by library */
-    hid_t       ret_value = FAIL;
-
-    FUNC_ENTER_API(FAIL)
+    H5VL_object_t  *obj         = NULL;                     /* Object token of loc_id */
+    H5I_type_t      opened_type;
+    void           *opened_obj  = NULL;
+    H5VL_loc_params_t loc_params;
+    hid_t           dxpl_id     = H5AC_ind_read_dxpl_id;    /* dxpl used by library */
+    hid_t           ret_value   = H5I_INVALID_HID;
+
+    FUNC_ENTER_API(H5I_INVALID_HID)
     H5TRACE3("i", "i*si", loc_id, name, lapl_id);
 
     /* Check args */
-    if(H5G_loc(loc_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
-    if(!name || !*name)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name")
+    if (!name)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "name parameter cannot be NULL")
+    if (!*name)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "name parameter cannot be an empty string")
 
     /* Verify access property list and get correct dxpl */
-    if(H5P_verify_apl_and_dxpl(&lapl_id, H5P_CLS_LACC, &dxpl_id, loc_id, FALSE) < 0)
-        HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
+    if (H5P_verify_apl_and_dxpl(&lapl_id, H5P_CLS_LACC, &dxpl_id, loc_id, FALSE) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, H5I_INVALID_HID, "can't set access and transfer property lists")
 
-    /* Open the object */
-    if((ret_value = H5O_open_name(&loc, name, lapl_id, dxpl_id, TRUE)) < 0)
-        HGOTO_ERROR(H5E_OHDR, H5E_CANTOPENOBJ, FAIL, "unable to open object")
+    /* Get the location object */
+    if (NULL == (obj = (H5VL_object_t *)H5I_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid location identifier")
+
+    /* Set location struct fields */
+    loc_params.type                         = H5VL_OBJECT_BY_NAME;
+    loc_params.loc_data.loc_by_name.name    = name;
+    loc_params.loc_data.loc_by_name.lapl_id = lapl_id;
+    loc_params.obj_type                     = H5I_get_type(loc_id);
+
+    /* Open the object through the VOL */
+    if (NULL == (opened_obj = H5VL_object_open(obj->vol_obj, loc_params, obj->vol_info->vol_cls, 
+                                              &opened_type, dxpl_id, H5_REQUEST_NULL)))
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTOPENOBJ, H5I_INVALID_HID, "unable to open object")
 
+    /* Get an atom for the object */
+    if ((ret_value = H5VL_register_id(opened_type, opened_obj, obj->vol_info, TRUE)) < 0)
+        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, H5I_INVALID_HID, "unable to atomize object handle")
 done:
     FUNC_LEAVE_API(ret_value)
 } /* end H5Oopen() */
@@ -419,41 +434,50 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Oexists_by_name
- *
- * Purpose:	Determine if a linked-to object exists
+ * Function:    H5Oexists_by_name
  *
- * Return:	Success:	TRUE/FALSE
- * 		Failure:	Negative
+ * Purpose:     Determine if a linked-to object exists
  *
- * Programmer:	Quincey Koziol
- *		February  2 2010
+ * Return:      Success:    TRUE/FALSE
+ *              Failure:    -1
  *
  *-------------------------------------------------------------------------
  */
 htri_t
 H5Oexists_by_name(hid_t loc_id, const char *name, hid_t lapl_id)
 {
-    H5G_loc_t	loc;                    /* Location info */
-    hid_t       dxpl_id = H5AC_ind_read_dxpl_id; /* dxpl used by library */
-    htri_t      ret_value = FAIL;       /* Return value */
+    H5VL_object_t  *obj         = NULL;         /* Object token of loc_id */
+    H5VL_loc_params_t loc_params;
+    hid_t           dxpl_id     = H5AC_ind_read_dxpl_id; /* dxpl used by library */
+    htri_t          ret_value   = -1;           /* Return value */
 
-    FUNC_ENTER_API(FAIL)
+    FUNC_ENTER_API((-1))
     H5TRACE3("t", "i*si", loc_id, name, lapl_id);
 
     /* Check args */
-    if(H5G_loc(loc_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
-    if(!name || !*name)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name")
+    if (!name)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, (-1), "name parameter cannot be NULL")
+    if (!*name)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, (-1), "name parameter cannot be an empty string")
 
     /* Verify access property list and get correct dxpl */
-    if(H5P_verify_apl_and_dxpl(&lapl_id, H5P_CLS_LACC, &dxpl_id, loc_id, FALSE) < 0)
-        HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
+    if (H5P_verify_apl_and_dxpl(&lapl_id, H5P_CLS_LACC, &dxpl_id, loc_id, FALSE) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, (-1), "can't set access and transfer property lists")
 
-    /* Check if the object exists */
-    if((ret_value = H5G_loc_exists(&loc, name, lapl_id, dxpl_id)) < 0)
-        HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "unable to determine if '%s' exists", name)
+    /* Get the location object */
+    if (NULL == (obj = H5VL_get_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, (-1), "invalid location identifier")
+
+    /* Set the location struct fields */
+    loc_params.type                         = H5VL_OBJECT_BY_NAME;
+    loc_params.loc_data.loc_by_name.name    = name;
+    loc_params.loc_data.loc_by_name.lapl_id = lapl_id;
+    loc_params.obj_type                     = H5I_get_type(loc_id);
+
+    /* Check if the object exists via the VOL */
+    if (H5VL_object_specific(obj->vol_obj, loc_params, obj->vol_info->vol_cls, H5VL_OBJECT_EXISTS, 
+                            dxpl_id, H5_REQUEST_NULL, &ret_value) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, (-1), "unable to determine if '%s' exists", name)
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -461,36 +485,40 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Oget_info
+ * Function:    H5Oget_info
  *
- * Purpose:	Retrieve information about an object.
- *
- * Return:	Success:	Non-negative
- *		Failure:	Negative
+ * Purpose:     Retrieve information about an object.
  *
- * Programmer:	Quincey Koziol
- *		November 21 2006
+ * Return:      SUCCEED/FAIL
  *
  *-------------------------------------------------------------------------
  */
 herr_t
 H5Oget_info(hid_t loc_id, H5O_info_t *oinfo)
 {
-    H5G_loc_t	loc;                    /* Location of group */
-    herr_t      ret_value = SUCCEED;    /* Return value */
+    H5VL_object_t      *obj         = NULL;         /* Object token of loc_id */
+    H5VL_loc_params_t   loc_params;
+    herr_t              ret_value   = SUCCEED;      /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE2("e", "i*x", loc_id, oinfo);
 
     /* Check args */
-    if(H5G_loc(loc_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
-    if(!oinfo)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no info struct")
+    if (!oinfo)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "oinfo parameter cannot be NULL")
 
-    /* Retrieve the object's information */
-    if(H5G_loc_info(&loc, ".", TRUE, oinfo/*out*/, H5P_LINK_ACCESS_DEFAULT, H5AC_ind_read_dxpl_id) < 0)
-        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
+    /* Set location struct fields */
+    loc_params.type         = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type     = H5I_get_type(loc_id);
+
+    /* Get the location object */
+    if (NULL == (obj = H5VL_get_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+
+    /* Get the group info through the VOL using the location token */
+    if (H5VL_object_optional(obj->vol_obj, obj->vol_info->vol_cls, H5AC_ind_read_dxpl_id, 
+                            H5_REQUEST_NULL, H5VL_OBJECT_GET_INFO, loc_params, oinfo) < 0)
+        HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get group info")
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -498,22 +526,19 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Oget_info_by_name
+ * Function:    H5Oget_info_by_name
  *
- * Purpose:	Retrieve information about an object.
+ * Purpose:     Retrieve information about an object.
  *
- * Return:	Success:	Non-negative
- *		Failure:	Negative
- *
- * Programmer:	Quincey Koziol
- *		November 21 2006
+ * Return:      SUCCEED/FAIL
  *
  *-------------------------------------------------------------------------
  */
 herr_t
 H5Oget_info_by_name(hid_t loc_id, const char *name, H5O_info_t *oinfo, hid_t lapl_id)
 {
-    H5G_loc_t	loc;                    /* Location of group */
+    H5VL_object_t    *obj = NULL;        /* object token of loc_id */
+    H5VL_loc_params_t loc_params;
     hid_t       dxpl_id = H5AC_ind_read_dxpl_id; /* dxpl used by library */
     herr_t      ret_value = SUCCEED;    /* Return value */
 
@@ -521,20 +546,31 @@ H5Oget_info_by_name(hid_t loc_id, const char *name, H5O_info_t *oinfo, hid_t lap
     H5TRACE4("e", "i*s*xi", loc_id, name, oinfo, lapl_id);
 
     /* Check args */
-    if(H5G_loc(loc_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
-    if(!name || !*name)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name")
-    if(!oinfo)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no info struct")
+    if (!name)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "name parameter cannot be NULL")
+    if (!*name)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "name parameter cannot be an empty string")
+    if (!oinfo)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "oinfo parameter cannot be NULL")
 
     /* Verify access property list and get correct dxpl */
-    if(H5P_verify_apl_and_dxpl(&lapl_id, H5P_CLS_LACC, &dxpl_id, loc_id, FALSE) < 0)
+    if (H5P_verify_apl_and_dxpl(&lapl_id, H5P_CLS_LACC, &dxpl_id, loc_id, FALSE) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
 
-    /* Retrieve the object's information */
-    if(H5G_loc_info(&loc, name, TRUE, oinfo/*out*/, lapl_id, dxpl_id) < 0)
-        HGOTO_ERROR(H5E_OHDR, H5E_NOTFOUND, FAIL, "object not found")
+    /* Fill out location struct */
+    loc_params.type                         = H5VL_OBJECT_BY_NAME;
+    loc_params.loc_data.loc_by_name.name    = name;
+    loc_params.loc_data.loc_by_name.lapl_id = lapl_id;
+    loc_params.obj_type                     = H5I_get_type(loc_id);
+
+    /* Get the location object */
+    if (NULL == (obj = H5VL_get_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+
+    /* Get the group info through the VOL using the location token */
+    if (H5VL_object_optional(obj->vol_obj, obj->vol_info->vol_cls, dxpl_id, H5_REQUEST_NULL,
+                            H5VL_OBJECT_GET_INFO, loc_params, oinfo) < 0)
+        HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get group info")
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -927,20 +963,16 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Oclose
+ * Function:    H5Oclose
  *
- * Purpose:	Close an open file object.
+ * Purpose:     Close an open file object.
  *
  *              This is the companion to H5Oopen. It is used to close any
  *              open object in an HDF5 file (but not IDs are that not file
  *              objects, such as property lists and dataspaces). It has
  *              the same effect as calling H5Gclose, H5Dclose, or H5Tclose.
  *
- * Return:	Success:	Non-negative
- *          Failure:	Negative
- *
- * Programmer:	James Laird
- *		July 14 2006
+ * Return:      SUCCEED/FAIL
  *
  *-------------------------------------------------------------------------
  */
@@ -980,7 +1012,7 @@ H5Oclose(hid_t object_id)
         default:
             HGOTO_ERROR(H5E_ARGS, H5E_CANTRELEASE, FAIL, "not a valid file object ID (dataset, group, or datatype)")
         break;
-    } /* end switch */
+    }
 
 done:
     FUNC_LEAVE_API(ret_value)
diff --git a/src/H5Rint.c b/src/H5Rint.c
index 716a573..6855a36 100644
--- a/src/H5Rint.c
+++ b/src/H5Rint.c
@@ -750,7 +750,7 @@ H5R_get_name(H5F_t *f, hid_t lapl_id, hid_t dxpl_id, hid_t id, H5R_type_t ref_ty
     } /* end switch */
 
     /* Retrieve file ID for name search */
-    if ((file_id = H5I_get_file_id(id, FALSE)) < 0)
+    if ((file_id = H5F_get_id(id, FALSE)) < 0)
         HGOTO_ERROR(H5E_REFERENCE, H5E_CANTGET, FAIL, "can't retrieve file ID")
 
     /* Get name, length, etc. */
diff --git a/src/H5Tcommit.c b/src/H5Tcommit.c
index ba5aacf..8f66ec0 100644
--- a/src/H5Tcommit.c
+++ b/src/H5Tcommit.c
@@ -36,6 +36,7 @@
 #include "H5MMprivate.h"        /* Memory Management                        */
 #include "H5Pprivate.h"         /* Property lists                           */
 #include "H5Tpkg.h"             /* Datatypes                                */
+#include "H5VLprivate.h"        /* Virtual Object Layer                     */
 
 
 /****************/
@@ -78,18 +79,21 @@ static H5T_t *H5T_open_oid(const H5G_loc_t *loc, hid_t dxpl_id);
 /* Local Variables */
 /*******************/
 
+/* Declare a free list to manage the H5VL_t struct */
+H5FL_EXTERN(H5VL_t);
+
+/* Declare a free list to manage the H5VL_object_t struct */
+H5FL_EXTERN(H5VL_object_t);
+
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Tcommit2
+ * Function:    H5Tcommit2
  *
- * Purpose:	Save a transient datatype to a file and turn the type handle
- *		into a "named", immutable type.
+ * Purpose:     Save a transient datatype to a file and turn the type handle
+ *              into a "named", immutable type.
  *
- * Return:	Non-negative on success/Negative on failure
- *
- * Programmer:  Quincey Koziol
- *              April 5, 2007
+ * Return:      SUCCEED/FAIL
  *
  *-------------------------------------------------------------------------
  */
@@ -97,43 +101,68 @@ herr_t
 H5Tcommit2(hid_t loc_id, const char *name, hid_t type_id, hid_t lcpl_id,
     hid_t tcpl_id, hid_t tapl_id)
 {
-    H5G_loc_t	loc;                    /* Location to create datatype */
-    H5T_t	*type;                  /* Datatype for ID */
-    hid_t       dxpl_id = H5AC_ind_read_dxpl_id; /* dxpl used by library */ 
-    herr_t      ret_value = SUCCEED;    /* Return value */
+    void *dt = NULL;                    /* datatype object created by VOL plugin */
+    H5VL_object_t *new_obj = NULL;      /* VOL object that holds the datatype object and the VOL info */
+    H5T_t *type = NULL;                 /* high level datatype object that wraps the VOL object */
+    H5VL_object_t *obj = NULL;          /* object token of loc_id */
+    hid_t dxpl_id = H5AC_ind_read_dxpl_id; /* dxpl used by library */ 
+    H5VL_loc_params_t loc_params;
+    herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE6("e", "i*siiii", loc_id, name, type_id, lcpl_id, tcpl_id, tapl_id);
 
     /* Check arguments */
-    if(H5G_loc(loc_id, &loc) < 0)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
-    if(!name || !*name)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name")
-    if(NULL == (type = (H5T_t *)H5I_object_verify(type_id, H5I_DATATYPE)))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a datatype")
+    if (!name)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "name parameter cannot be NULL")
+    if (!*name)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "name parameter cannot be an empty string")
+    if (NULL == (type = (H5T_t *)H5I_object_verify(type_id, H5I_DATATYPE)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a datatype")
+    if (H5T_is_named(type))
+        HGOTO_ERROR(H5E_ARGS, H5E_CANTSET, FAIL, "datatype is already committed")
 
     /* Get correct property list */
-    if(H5P_DEFAULT == lcpl_id)
+    if (H5P_DEFAULT == lcpl_id)
         lcpl_id = H5P_LINK_CREATE_DEFAULT;
     else
-        if(TRUE != H5P_isa_class(lcpl_id, H5P_LINK_CREATE))
+        if (TRUE != H5P_isa_class(lcpl_id, H5P_LINK_CREATE))
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not link creation property list")
 
     /* Get correct property list */
-    if(H5P_DEFAULT == tcpl_id)
+    if (H5P_DEFAULT == tcpl_id)
         tcpl_id = H5P_DATATYPE_CREATE_DEFAULT;
     else
-        if(TRUE != H5P_isa_class(tcpl_id, H5P_DATATYPE_CREATE))
+        if (TRUE != H5P_isa_class(tcpl_id, H5P_DATATYPE_CREATE))
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not datatype creation property list")
 
     /* Verify access property list and get correct dxpl */
-    if(H5P_verify_apl_and_dxpl(&tapl_id, H5P_CLS_TACC, &dxpl_id, loc_id, TRUE) < 0)
+    if (H5P_verify_apl_and_dxpl(&tapl_id, H5P_CLS_TACC, &dxpl_id, loc_id, TRUE) < 0)
         HGOTO_ERROR(H5E_DATATYPE, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
 
-    /* Commit the type */
-    if(H5T__commit_named(&loc, name, type, lcpl_id, tcpl_id, tapl_id, dxpl_id) < 0)
-	HGOTO_ERROR(H5E_DATATYPE, H5E_CANTINIT, FAIL, "unable to commit datatype")
+    /* Fill in location struct fields */
+    loc_params.type         = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type     = H5I_get_type(loc_id);
+
+    /* Get the object from the loc_id */
+    if (NULL == (obj = (H5VL_object_t *)H5I_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid object identifier")
+
+    /* Commit the datatype through the VOL */
+    if (NULL == (dt = H5VL_datatype_commit(obj->vol_obj, loc_params, obj->vol_info->vol_cls, 
+                                           name, type_id, lcpl_id, tcpl_id, tapl_id, 
+                                           dxpl_id, H5_REQUEST_NULL)))
+        HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to commit datatype")
+
+    /* setup VOL object */
+    if (NULL == (new_obj = H5FL_CALLOC(H5VL_object_t)))
+        HGOTO_ERROR(H5E_VOL, H5E_NOSPACE, FAIL, "can't allocate top object structure")
+    new_obj->vol_info = obj->vol_info;
+    new_obj->vol_info->nrefs ++;
+    new_obj->vol_obj = dt;
+
+    /* set the committed type object to the VOL driver pointer in the H5T_t struct */
+    type->vol_obj = new_obj;
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -506,150 +535,118 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Topen2
+ * Function:    H5Topen2
  *
- * Purpose:	Opens a named datatype using a Datatype Access Property
+ * Purpose:     Opens a named datatype using a Datatype Access Property
  *              List.
  *
- * Return:	Success:	Object ID of the named datatype.
- *		Failure:	Negative
+ * Return:      Success:    Object ID of the named datatype
  *
- * Programmer:	James Laird
- *              Thursday July 27, 2006
+ *              Failure:    H5I_INVALID_HID
  *
  *-------------------------------------------------------------------------
  */
 hid_t
 H5Topen2(hid_t loc_id, const char *name, hid_t tapl_id)
 {
-    H5T_t      *type = NULL;           /* Datatype opened in file */
-    H5G_loc_t	 loc;                   /* Group location of object to open */
-    H5G_name_t   path;            	/* Datatype group hier. path */
-    H5O_loc_t    oloc;            	/* Datatype object location */
-    H5O_type_t   obj_type;              /* Type of object at location */
-    H5G_loc_t    type_loc;              /* Group object for datatype */
-    hbool_t      obj_found = FALSE;     /* Object at 'name' found */
-    hid_t        dxpl_id = H5AC_ind_read_dxpl_id; /* dxpl to use to open datatype */
-    hid_t        ret_value = FAIL;      /* Return value */
+    void *vol_dt = NULL;           /* datatype token created by VOL plugin */
+    H5VL_object_t *obj = NULL;     /* object token of loc_id */
+    H5VL_loc_params_t loc_params;
+    hid_t dxpl_id = H5AC_ind_read_dxpl_id; /* dxpl used by library */
+    hid_t ret_value = H5I_INVALID_HID;    /* Return value */
 
-    FUNC_ENTER_API(FAIL)
+    FUNC_ENTER_API(H5I_INVALID_HID)
     H5TRACE3("i", "i*si", loc_id, name, tapl_id);
 
     /* Check args */
-    if(H5G_loc(loc_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
-    if(!name || !*name)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name")
+    if (!name)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "name parameter cannot be NULL")
+    if (!*name)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "name parameter cannot be an empty string")
 
     /* Verify access property list and get correct dxpl */
-    if(H5P_verify_apl_and_dxpl(&tapl_id, H5P_CLS_TACC, &dxpl_id, loc_id, FALSE) < 0)
-        HGOTO_ERROR(H5E_DATATYPE, H5E_CANTSET, FAIL, "can't set access and transfer property lists")
+    if (H5P_verify_apl_and_dxpl(&tapl_id, H5P_CLS_TACC, &dxpl_id, loc_id, FALSE) < 0)
+        HGOTO_ERROR(H5E_DATATYPE, H5E_CANTSET, H5I_INVALID_HID, "can't set access and transfer property lists")
 
-    /* Set up datatype location to fill in */
-    type_loc.oloc = &oloc;
-    type_loc.path = &path;
-    H5G_loc_reset(&type_loc);
+    /* Fill in location struct fields */
+    loc_params.type         = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type     = H5I_get_type(loc_id);
 
-    /*
-     * Find the named datatype object header and read the datatype message
-     * from it.
-     */
-    if(H5G_loc_find(&loc, name, &type_loc/*out*/, tapl_id, dxpl_id) < 0)
-        HGOTO_ERROR(H5E_DATATYPE, H5E_NOTFOUND, FAIL, "not found")
-    obj_found = TRUE;
+    /* get the location object */
+    if (NULL == (obj = (H5VL_object_t *)H5I_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid file identifier")
 
-    /* Check that the object found is the correct type */
-    if(H5O_obj_type(&oloc, &obj_type, dxpl_id) < 0)
-        HGOTO_ERROR(H5E_DATATYPE, H5E_CANTGET, FAIL, "can't get object type")
-    if(obj_type != H5O_TYPE_NAMED_DATATYPE)
-        HGOTO_ERROR(H5E_DATATYPE, H5E_BADTYPE, FAIL, "not a named datatype")
+    /* Create the datatype through the VOL */
+    if (NULL == (vol_dt = H5VL_datatype_open(obj->vol_obj, loc_params, obj->vol_info->vol_cls, 
+                                            name, tapl_id, dxpl_id, H5_REQUEST_NULL)))
+        HGOTO_ERROR(H5E_SYM, H5E_CANTOPENOBJ, H5I_INVALID_HID, "unable to open datatype")
 
-    /* Open it */
-    if(NULL == (type = H5T_open(&type_loc, dxpl_id)))
-        HGOTO_ERROR(H5E_DATATYPE, H5E_CANTOPENOBJ, FAIL, "unable to open named datatype")
-
-    /* Register the type and return the ID */
-    if((ret_value = H5I_register(H5I_DATATYPE, type, TRUE)) < 0)
-        HGOTO_ERROR(H5E_DATATYPE, H5E_CANTREGISTER, FAIL, "unable to register named datatype")
+    /* Get an atom for the datatype */
+    if ((ret_value = H5VL_register_id(H5I_DATATYPE, vol_dt, obj->vol_info, TRUE)) < 0)
+        HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, H5I_INVALID_HID, "unable to atomize datatype handle")
 
 done:
-    if(ret_value < 0) {
-        if(type != NULL)
-            H5T_close(type);
-        else {
-            if(obj_found && H5F_addr_defined(type_loc.oloc->addr))
-                H5G_loc_free(&type_loc);
-        } /* end else */
-    } /* end if */
-
+    if (H5I_INVALID_HID == ret_value)
+        if (vol_dt && H5VL_datatype_close (vol_dt, obj->vol_info->vol_cls, dxpl_id, H5_REQUEST_NULL) < 0)
+            HDONE_ERROR(H5E_SYM, H5E_CLOSEERROR, H5I_INVALID_HID, "unable to release datatype")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Topen2() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Tget_create_plist
+ * Function:    H5Tget_create_plist
  *
- * Purpose:	Returns a copy of the datatype creation property list.
+ * Purpose:     Returns a copy of the datatype creation property list.
  *
- * Return:	Success:	ID for a copy of the datatype creation
- *				property list.  The property list ID should be
- *				released by calling H5Pclose().
+ * Return:      Success:    ID for a copy of the datatype creation
+ *                          property list.  The property list ID should be
+ *                          released by calling H5Pclose().
  *
- *		Failure:	FAIL
- *
- * Programmer:	Quincey Koziol
- *		Tuesday, November 28, 2006
+ *              Failure:    H5I_INVALID_HID
  *
  *-------------------------------------------------------------------------
  */
 hid_t
 H5Tget_create_plist(hid_t dtype_id)
 {
-    H5T_t	        *type;          /* Datatype object for ID */
-    H5P_genplist_t      *tcpl_plist;    /* Existing datatype creation propertty list */
-    hid_t		new_tcpl_id = FAIL;     /* New datatype creation property list */
-    herr_t              status;         /* Generic status value */
-    hid_t		ret_value;      /* Return value */
+    H5T_t	       *type        = NULL;             /* Datatype object for ID */
+    H5P_genplist_t *tcpl_plist  = NULL;             /* Existing datatype creation propertty list */
+    htri_t          status;                         /* Generic status value */
+    hid_t           ret_value   = H5I_INVALID_HID;  /* Return value */
 
-    FUNC_ENTER_API(FAIL)
+    FUNC_ENTER_API(H5I_INVALID_HID)
     H5TRACE1("i", "i", dtype_id);
 
     /* Check arguments */
-    if(NULL == (type = (H5T_t *)H5I_object_verify(dtype_id, H5I_DATATYPE)))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a datatype")
-
-    /* Copy the default datatype creation property list */
-    if(NULL == (tcpl_plist = (H5P_genplist_t *)H5I_object(H5P_LST_DATATYPE_CREATE_ID_g)))
-         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get default creation property list")
-    if((new_tcpl_id = H5P_copy_plist(tcpl_plist, TRUE)) < 0)
-        HGOTO_ERROR(H5E_DATATYPE, H5E_CANTGET, FAIL, "unable to copy the creation property list")
+    if (NULL == (type = (H5T_t *)H5I_object_verify(dtype_id, H5I_DATATYPE)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a datatype")
 
     /* Check if the datatype is committed */
-    if((status = H5T_committed(type)) < 0)
-        HGOTO_ERROR(H5E_DATATYPE, H5E_CANTGET, FAIL, "can't check whether datatype is committed")
-
-    /* Retrieve further information, if the datatype is committed */
-    if(status > 0) {
-        H5P_genplist_t  *new_plist;     /* New datatype creation property list */
-
-        /* Get property list object for new TCPL */
-        if(NULL == (new_plist = (H5P_genplist_t *)H5I_object(new_tcpl_id)))
-            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
-
-        /* Retrieve any object creation properties */
-        if(H5O_get_create_plist(&type->oloc, H5AC_ind_read_dxpl_id, new_plist) < 0)
-            HGOTO_ERROR(H5E_DATATYPE, H5E_CANTGET, FAIL, "can't get object creation info")
-    } /* end if */
+    if ((status = H5T_is_named(type)) < 0)
+        HGOTO_ERROR(H5E_DATATYPE, H5E_CANTGET, H5I_INVALID_HID, "can't check whether datatype is committed")
+
+    /* If the datatype is not committed, just copy the default
+       creation property list and return that. */
+    if (FALSE == status) {
+        /* Copy the default datatype creation property list */
+        if (NULL == (tcpl_plist = (H5P_genplist_t *)H5I_object(H5P_LST_DATATYPE_CREATE_ID_g)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "can't get default creation property list")
+        if ((ret_value = H5P_copy_plist(tcpl_plist, TRUE)) < 0)
+            HGOTO_ERROR(H5E_DATATYPE, H5E_CANTGET, H5I_INVALID_HID, "unable to copy the creation property list")
+    }
+    /* If the datatype is committed, let the VOL create the creation
+     * property list ID.
+     */
+    else if (TRUE == status) {
+        H5VL_object_t *vol_dt = type->vol_obj;
 
-    /* Set the return value */
-    ret_value = new_tcpl_id;
+        /* get the rest of the plist through the VOL */
+        if (H5VL_datatype_get(vol_dt->vol_obj, vol_dt->vol_info->vol_cls, H5VL_DATATYPE_GET_TCPL, 
+                             H5AC_ind_read_dxpl_id, H5_REQUEST_NULL, &ret_value) < 0)
+            HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, H5I_INVALID_HID, "unable to get datatype")
+    }
 
 done:
-    if(ret_value < 0)
-        if(new_tcpl_id > 0)
-            if(H5I_dec_app_ref(new_tcpl_id) < 0)
-                HDONE_ERROR(H5E_DATATYPE, H5E_CANTDEC, FAIL, "unable to close temporary object")
-
     FUNC_LEAVE_API(ret_value)
 } /* end H5Tget_create_plist() */
 
diff --git a/src/H5VLnative.c b/src/H5VLnative.c
index e8b2725..d83d32e 100644
--- a/src/H5VLnative.c
+++ b/src/H5VLnative.c
@@ -1601,7 +1601,7 @@ H5VL_native_file_get(void *obj, H5VL_file_get_t get_type, hid_t H5_ATTR_UNUSED d
                 *ret = (ssize_t)len;
                 break;
             }
-        /* H5I_get_file_id */
+        /* H5Iget_file_id */
         case H5VL_OBJECT_GET_FILE:
             {
                 H5I_type_t  type = va_arg(arguments, H5I_type_t);
diff --git a/src/H5Z.c b/src/H5Z.c
index 6f173b2..901e65b 100644
--- a/src/H5Z.c
+++ b/src/H5Z.c
@@ -335,12 +335,12 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function: H5Zunregister
+ * Function:    H5Zunregister
  *
- * Purpose:  This function unregisters a filter.
+ * Purpose:     This function unregisters a filter.
+ *
+ * Return:      SUCCEED/FAIL
  *
- * Return:   Non-negative on success
- *           Negative on failure
  *-------------------------------------------------------------------------
  */
 herr_t
@@ -367,13 +367,13 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function: H5Z_unregister
+ * Function:    H5Z_unregister
  *
- * Purpose:  Same as the public version except this one allows filters
- *           to be unset for predefined method numbers <H5Z_FILTER_RESERVED
+ * Purpose:     Same as the public version except this one allows filters
+ *               to be unset for predefined method numbers <H5Z_FILTER_RESERVED
+ *
+ * Return:      SUCCEED/FAIL
  *
- * Return:   Non-negative on success
- *           Negative on failure
  *-------------------------------------------------------------------------
  */
 herr_t
@@ -432,12 +432,14 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function: H5Z__check_unregister
+ * Function:    H5Z__check_unregister
  *
- * Purpose: Check if an object uses the filter to be unregistered.
+ * Purpose:     Check if an object uses the filter to be unregistered.
+ *
+ * Return:      TRUE if the object uses the filter
+ *              FALSE if not
+ *              NEGATIVE on error
  *
- * Return:  TRUE if the object uses the filter.
- *          FALSE if not, NEGATIVE on error.
  *-------------------------------------------------------------------------
  */
 static htri_t
@@ -462,15 +464,17 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function: H5Z__check_unregister_group_cb
+ * Function:    H5Z__check_unregister_group_cb
+ *
+ * Purpose:     The callback function for H5Z_unregister. It iterates
+ *              through all opened objects.  If the object is a dataset
+ *              or a group and it uses the filter to be unregistered, the
+ *              function returns TRUE.
  *
- * Purpose:  The callback function for H5Z_unregister. It iterates
- *           through all opened objects.  If the object is a dataset
- *           or a group and it uses the filter to be unregistered, the
- *           function returns TRUE.
+ * Return:      TRUE if the object uses the filter
+ *              FALSE if not
+ *              NEGATIVE on error
  *
- * Return:   TRUE if the object uses the filter.
- *           FALSE otherwise.
  *-------------------------------------------------------------------------
  */
 static int
@@ -499,7 +503,7 @@ H5Z__check_unregister_group_cb(void *obj_ptr, hid_t H5_ATTR_UNUSED obj_id, void
     if (filter_in_pline) {
         object->found = TRUE;
         ret_value = TRUE;
-    } /* end if */
+    }
 
 done:
     if (ocpl_id > 0)
@@ -511,15 +515,17 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function: H5Z__check_unregister_dset_cb
+ * Function:    H5Z__check_unregister_dset_cb
  *
- * Purpose: The callback function for H5Z_unregister. It iterates
- *          through all opened objects.  If the object is a dataset
- *          or a group and it uses the filter to be unregistered, the
- *          function returns TRUE.
+ * Purpose:     The callback function for H5Z_unregister. It iterates
+ *              through all opened objects.  If the object is a dataset
+ *              or a group and it uses the filter to be unregistered, the
+ *              function returns TRUE.
+ *
+ * Return:      TRUE if the object uses the filter
+ *              FALSE if not
+ *              NEGATIVE on error
  *
- * Return:  TRUE if the object uses the filter.
- *          FALSE otherwise.
  *-------------------------------------------------------------------------
  */
 static int
@@ -548,7 +554,7 @@ H5Z__check_unregister_dset_cb(void *obj_ptr, hid_t H5_ATTR_UNUSED obj_id, void *
     if (filter_in_pline) {
         object->found = TRUE;
         ret_value = TRUE;
-    } /* end if */
+    }
 
 done:
     if (ocpl_id > 0)
@@ -560,13 +566,13 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function: H5Z__flush_file_cb
+ * Function:    H5Z__flush_file_cb
  *
- * Purpose:  The callback function for H5Z_unregister. It iterates
- *           through all opened files and flush them.
+ * Purpose:     The callback function for H5Z_unregister. It iterates
+ *              through all opened files and flush them.
  *
- * Return:   FALSE if finishes flushing and moves on
- *           FAIL if there is an error
+ * Return:      FALSE if finishes flushing and moves on
+ *              NEGATIVE if there is an error
  *-------------------------------------------------------------------------
  */
 static int
@@ -579,11 +585,12 @@ H5Z__flush_file_cb(void *obj_ptr, hid_t H5_ATTR_UNUSED obj_id, void H5_ATTR_UNUS
     HDassert(obj_ptr);
 
     /* Call the flush routine for mounted file hierarchies. Do a global flush
-     * if the file is opened for write */
+     * if the file is opened for write.
+     */
     if (H5F_ACC_RDWR & H5F_INTENT((H5F_t *)obj_ptr)) {
         if (H5F_flush_mounts((H5F_t *)obj_ptr, H5AC_ind_read_dxpl_id, H5AC_rawdata_dxpl_id) < 0)
             HGOTO_ERROR(H5E_PLINE, H5E_CANTFLUSH, FAIL, "unable to flush file hierarchy")
-    } /* end if */
+    }
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
diff --git a/test/fillval.c b/test/fillval.c
index 8c8e902..f0182c2 100644
--- a/test/fillval.c
+++ b/test/fillval.c
@@ -762,15 +762,17 @@ test_rdwr_cases(hid_t file, hid_t dcpl, const char *dname, void *_fillval,
     comp_datatype	*buf_c=NULL;
     H5D_space_status_t  allocation;
 
-    if(datatype==H5T_INTEGER)
+    if(datatype==H5T_INTEGER) {
         fillval = *(int*)_fillval;
+    }
     else if(datatype==H5T_COMPOUND) {
-	fill_c.a=((comp_datatype*)_fillval)->a;
+        fill_c.a=((comp_datatype*)_fillval)->a;
         fill_c.x=((comp_datatype*)_fillval)->x;
         fill_c.y=((comp_datatype*)_fillval)->y;
         fill_c.z=((comp_datatype*)_fillval)->z;
-    } else {
-        puts("Invalid type for test");
+    }
+    else {
+        HDputs("Invalid type for test");
         goto error;
     }
 
@@ -806,7 +808,8 @@ test_rdwr_cases(hid_t file, hid_t dcpl, const char *dname, void *_fillval,
 	        goto error;
 	    }
 	/* case for compound datatype */
-	} else if(datatype==H5T_COMPOUND) {
+	}
+    else if(datatype==H5T_COMPOUND) {
             if(H5Dread(dset2, ctype_id, mspace, fspace, H5P_DEFAULT,
                 &rd_c) < 0) goto error;
             if(fill_time != H5D_FILL_TIME_NEVER && (!H5_FLT_ABS_EQUAL(rd_c.a, fill_c.a) ||
@@ -828,10 +831,10 @@ test_rdwr_cases(hid_t file, hid_t dcpl, const char *dname, void *_fillval,
 
     /* Select all odd data locations in the file dataset */
     for (i=0, nelmts=1; i<5; i++) {
-	hs_size[i] = cur_size[i]/2;
-	hs_offset[i] = 0;
-	hs_stride[i] = 2;
-	nelmts *= hs_size[i];
+        hs_size[i] = cur_size[i]/2;
+        hs_offset[i] = 0;
+        hs_stride[i] = 2;
+        nelmts *= hs_size[i];
     }
     if((mspace=H5Screate_simple(5, hs_size, hs_size)) < 0) goto error;
     if(H5Sselect_hyperslab(fspace, H5S_SELECT_SET, hs_offset, hs_stride,
@@ -1092,14 +1095,20 @@ test_rdwr(hid_t fapl, const char *base_name, H5D_layout_t layout)
     if((file=H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, fapl)) < 0)
         goto error;
 
-    if((dcpl=H5Pcreate(H5P_DATASET_CREATE)) < 0) goto error;
+    if((dcpl=H5Pcreate(H5P_DATASET_CREATE)) < 0)
+        goto error;
+
     if(H5D_CHUNKED==layout) {
-        if(H5Pset_chunk(dcpl, 5, ch_size) < 0) goto error;
-    } else if(H5D_COMPACT==layout) {
-        if(H5Pset_layout(dcpl, H5D_COMPACT) < 0) goto error;
+        if(H5Pset_chunk(dcpl, 5, ch_size) < 0)
+            goto error;
+    }
+    else if(H5D_COMPACT==layout) {
+        if(H5Pset_layout(dcpl, H5D_COMPACT) < 0)
+            goto error;
     }
-    if((ctype_id=create_compound_type()) < 0) goto error;
 
+    if((ctype_id=create_compound_type()) < 0)
+        goto error;
 
     /* I. Test H5D_ALLOC_TIME_LATE space allocation cases */
     if(H5D_COMPACT != layout) {
@@ -2359,8 +2368,6 @@ test_partalloc(hid_t fapl, const char *base_name)
  * Programmer:	Robb Matzke
  *              Thursday, October  1, 1998
  *
- * Modifications:
- *
  *-------------------------------------------------------------------------
  */
 int
@@ -2380,8 +2387,8 @@ main(int argc, char *argv[])
             else if(!strcmp(argv[argno], "compact"))
                 test_compact =1;
             else {
-                fprintf(stderr, "usage: %s [contiguous] [chunked] [compact]\n", argv[0]);
-                exit(EXIT_FAILURE);
+                HDfprintf(stderr, "usage: %s [contiguous] [chunked] [compact]\n", argv[0]);
+                HDexit(EXIT_FAILURE);
             }
         } /* end for */
     } /* end if */
@@ -2444,15 +2451,15 @@ main(int argc, char *argv[])
 
     if(nerrors)
         goto error;
-    puts("All fill value tests passed.");
+    HDputs("All fill value tests passed.");
 
     if(h5_cleanup(FILENAME, fapl))
         HDremove(FILE_NAME_RAW);
 
-    return 0;
+    HDexit(EXIT_SUCCESS);
 
 error:
-    puts("***** FILL VALUE TESTS FAILED *****");
-    return 1;
+    HDputs("***** FILL VALUE TESTS FAILED *****");
+    HDexit(EXIT_FAILURE);
 }
 
diff --git a/test/unregister.c b/test/unregister.c
index a4bf24e..52f8a28 100644
--- a/test/unregister.c
+++ b/test/unregister.c
@@ -23,8 +23,8 @@ const char *FILENAME[] = {
     NULL
 };
 
-#define GROUP_NAME              "group"
-#define DSET_NAME               "dataset"
+#define GROUP_NAME              "test_group"
+#define DSET_NAME               "test_dataset"
 #define FILENAME_BUF_SIZE       1024
 #define DSET_DIM1               100
 #define DSET_DIM2               200
@@ -34,39 +34,34 @@ const char *FILENAME[] = {
 
 #define H5Z_FILTER_DUMMY        312
 
-static size_t filter_dummy(unsigned int flags, size_t cd_nelmts,
+static size_t do_nothing(unsigned int flags, size_t cd_nelmts,
     const unsigned int *cd_values, size_t nbytes, size_t *buf_size, void **buf);
 
 /* Dummy filter for test_unregister_filters only */
 const H5Z_class2_t H5Z_DUMMY[1] = {{
-    H5Z_CLASS_T_VERS,           /* H5Z_class_t version */
-    H5Z_FILTER_DUMMY,		/* Filter id number		*/
-    1, 1,                       /* Encoding and decoding enabled */
-    "dummy",			/* Filter name for debugging	*/
-    NULL,                       /* The "can apply" callback     */
-    NULL,                       /* The "set local" callback     */
-    filter_dummy,		/* The actual filter function	*/
+    H5Z_CLASS_T_VERS,           /* H5Z_class_t version              */
+    H5Z_FILTER_DUMMY,           /* Filter ID number                 */
+    1, 1,                       /* Encoding and decoding enabled    */
+    "dummy",                    /* Filter name for debugging        */
+    NULL,                       /* The "can apply" callback         */
+    NULL,                       /* The "set local" callback         */
+    do_nothing,                 /* The actual filter function       */
 }};
 
 
 /*-------------------------------------------------------------------------
- * Function:	filter_dummy
+ * Function:    do_nothing
  *
- * Purpose:	A dummy compression method that doesn't do anything.  This
- *              filter is only for test_unregister_filters.  Please don't 
+ * Purpose:     A dummy compression method that doesn't do anything. This
+ *              filter is only for test_unregister_filters. Please don't 
  *              use it for other tests because it may mess up this test.
  *
- * Return:	Success:	Data chunk size
- *
- *		Failure:	0
- *
- * Programmer:	Raymond Lu
- *              April 24, 2013
+ * Return:      Data chunk size
  *
  *-------------------------------------------------------------------------
  */
 static size_t
-filter_dummy(unsigned int H5_ATTR_UNUSED flags, size_t H5_ATTR_UNUSED cd_nelmts,
+do_nothing(unsigned int H5_ATTR_UNUSED flags, size_t H5_ATTR_UNUSED cd_nelmts,
       const unsigned int H5_ATTR_UNUSED *cd_values, size_t nbytes,
       size_t H5_ATTR_UNUSED *buf_size, void H5_ATTR_UNUSED **buf)
 {
@@ -74,181 +69,220 @@ filter_dummy(unsigned int H5_ATTR_UNUSED flags, size_t H5_ATTR_UNUSED cd_nelmts,
 }
 
 /*-------------------------------------------------------------------------
- * Function:	test_unregister_filters
+ * Function:    test_unregister_filters
  *
- * Purpose:	Tests unregistering filter before closing the file
+ * Purpose:     Tests unregistering filter before closing the file
  *
- * Return:	Success:	0
- *		Failure:	-1
- *
- * Programmer:	Raymond Lu
- *              11 April 2013
+ * Return:      SUCCEED/FAIL
  *
  *-------------------------------------------------------------------------
  */
 static herr_t
-test_unregister_filters(hid_t my_fapl)
+test_unregister_filters(hid_t fapl_id)
 {
-    hid_t	file1, file2;
-    hid_t	dc;
-    hid_t	gcpl, gid, group;
-    hid_t       dataset, space;
-    int		i, j, n;
-    char        gname[256];
+    hid_t       fid1        = H5I_INVALID_HID;
+    hid_t       fid2        = H5I_INVALID_HID;
+    hid_t       dcpl_id     = H5I_INVALID_HID;
+    hid_t       gcpl_id     = H5I_INVALID_HID;
+    hid_t       gid         = H5I_INVALID_HID;
+    hid_t       gid_loop    = H5I_INVALID_HID;
+    hid_t       did         = H5I_INVALID_HID;
+    hid_t       sid         = H5I_INVALID_HID;
+    int         i, j, n;
+    char        group_name[32];
     char        filename[FILENAME_BUF_SIZE];
-    const hsize_t chunk_size[2] = {FILTER_CHUNK_DIM1, FILTER_CHUNK_DIM2};  /* Chunk dimensions */
-    hsize_t	dims[2];
-    int	        points[DSET_DIM1][DSET_DIM2];
+    const hsize_t chunk_dims[2] = {FILTER_CHUNK_DIM1, FILTER_CHUNK_DIM2};  /* Chunk dimensions */
+    hsize_t     dims[2];
+    int	        data[DSET_DIM1][DSET_DIM2];
     herr_t      ret;
 
     TESTING("Unregistering filter");
 
     /* Create first file */
-    h5_fixname(FILENAME[0], my_fapl, filename, sizeof filename);
-    if((file1 = H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, my_fapl)) < 0) goto error;
+    h5_fixname(FILENAME[0], fapl_id, filename, sizeof(filename));
+    if ((fid1 = H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, fapl_id)) < 0)
+        goto error;
 
     /* Create second file */
-    h5_fixname(FILENAME[1], my_fapl, filename, sizeof filename);
-    if((file2 = H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, my_fapl)) < 0) goto error;
+    h5_fixname(FILENAME[1], fapl_id, filename, sizeof(filename));
+    if ((fid2 = H5Fcreate(filename, H5F_ACC_TRUNC, H5P_DEFAULT, fapl_id)) < 0)
+        goto error;
 
     /* Register DUMMY filter */
-    if(H5Zregister(H5Z_DUMMY) < 0) goto error;
-
-    if(H5Zfilter_avail(H5Z_FILTER_DUMMY)!=TRUE) goto error;
+    if (H5Zregister(H5Z_DUMMY) < 0)
+        goto error;
+    if (H5Zfilter_avail(H5Z_FILTER_DUMMY) != TRUE)
+        goto error;
+ 
+    /*******************
+     * PART 1 - GROUPS *
+     *******************/
 
-    if((gcpl = H5Pcreate(H5P_GROUP_CREATE)) < 0) goto error;
-  
     /* Use DUMMY filter for creating groups */ 
-    if(H5Pset_filter (gcpl, H5Z_FILTER_DUMMY, H5Z_FLAG_MANDATORY, (size_t)0, NULL) < 0) goto error;
+    if ((gcpl_id = H5Pcreate(H5P_GROUP_CREATE)) < 0)
+        goto error;
+    if (H5Pset_filter(gcpl_id, H5Z_FILTER_DUMMY, H5Z_FLAG_MANDATORY, (size_t)0, NULL) < 0)
+        goto error;
 
     /* Create a group using this filter */
-    if((gid = H5Gcreate2(file1, GROUP_NAME, H5P_DEFAULT, gcpl, H5P_DEFAULT)) < 0) goto error;
+    if ((gid = H5Gcreate2(fid1, GROUP_NAME, H5P_DEFAULT, gcpl_id, H5P_DEFAULT)) < 0)
+        goto error;
 
     /* Create multiple groups under the main group */
-    for (i=0; i < GROUP_ITERATION; i++) {
-        sprintf(gname, "group_%d", i);
-        if((group = H5Gcreate2(gid, gname, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0) goto error;
-        if(H5Gclose(group) < 0) goto error; 
+    for (i = 0; i < GROUP_ITERATION; i++) {
+        HDsprintf(group_name, "group_%d", i);
+        if ((gid_loop = H5Gcreate2(gid, group_name, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+            goto error;
+        if (H5Gclose(gid_loop) < 0)
+            goto error; 
     }
 
-    if(H5Fflush(file1, H5F_SCOPE_GLOBAL) < 0) goto error;
+    /* Flush the file containing the groups */
+    if (H5Fflush(fid1, H5F_SCOPE_GLOBAL) < 0)
+        goto error;
 
     /* Unregister the filter before closing the group.  It should fail */
     H5E_BEGIN_TRY {
         ret = H5Zunregister(H5Z_FILTER_DUMMY);
     } H5E_END_TRY;
-    if(ret>=0) {
+    if (ret >= 0) {
         H5_FAILED();
-        printf("    Line %d: Should not be able to unregister filter\n", __LINE__);
+        HDprintf("    Line %d: Should not be able to unregister filter\n", __LINE__);
         goto error;
-    } /* end if */
+    }
 
     /* Close the group */
-    if(H5Gclose(gid) < 0) goto error;
+    if (H5Gclose(gid) < 0)
+        goto error;
 
     /* Clean up objects used for this test */
-    if(H5Pclose (gcpl) < 0) goto error;
+    if (H5Pclose (gcpl_id) < 0)
+        goto error;
 
-    if((dc = H5Pcreate(H5P_DATASET_CREATE)) < 0) goto error;
-    if(H5Pset_chunk (dc, 2, chunk_size) < 0) goto error;
+    /*********************
+     * PART 2 - DATASETS *
+     *********************/
 
-    if(H5Pset_filter(dc, H5Z_FILTER_DUMMY, 0, (size_t)0, NULL) < 0) goto error;
+    /* Use DUMMY filter for creating datasets */ 
+    if ((dcpl_id = H5Pcreate(H5P_DATASET_CREATE)) < 0)
+        goto error;
+    if (H5Pset_chunk(dcpl_id, 2, chunk_dims) < 0)
+        goto error;
+    if(H5Pset_filter(dcpl_id, H5Z_FILTER_DUMMY, 0, (size_t)0, NULL) < 0)
+        goto error;
 
-    /* Initialize the dataset */
-    for(i = n = 0; i < DSET_DIM1; i++)
-        for(j = 0; j < DSET_DIM2; j++)
-            points[i][j] = n++;
+    /* Initialize the data for writing */
+    for (i = n = 0; i < DSET_DIM1; i++)
+        for (j = 0; j < DSET_DIM2; j++)
+            data[i][j] = n++;
 
-    /* Create the data space */
+    /* Create the dataspace */
     dims[0] = DSET_DIM1;
     dims[1] = DSET_DIM2;
-    if((space = H5Screate_simple(2, dims, NULL)) < 0) goto error;
+    if ((sid = H5Screate_simple(2, dims, NULL)) < 0)
+        goto error;
 
     /* Create a dataset in the first file */
-    if((dataset = H5Dcreate2(file1, DSET_NAME, H5T_NATIVE_INT, space,
-                             H5P_DEFAULT, dc, H5P_DEFAULT)) < 0) goto error;
+    if ((did = H5Dcreate2(fid1, DSET_NAME, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl_id, H5P_DEFAULT)) < 0)
+        goto error;
 
     /* Write the data to the dataset */
-    if(H5Dwrite(dataset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, points) < 0)
+    if (H5Dwrite(did, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, data) < 0)
         goto error;
 
     /* Unregister the filter before closing the dataset.  It should fail */
     H5E_BEGIN_TRY {
         ret = H5Zunregister(H5Z_FILTER_DUMMY);
     } H5E_END_TRY;
-    if(ret>=0) {
+    if (ret >= 0) {
         H5_FAILED();
-        printf("    Line %d: Should not be able to unregister filter\n", __LINE__);
+        HDprintf("    Line %d: Should not be able to unregister filter\n", __LINE__);
         goto error;
-    } /* end if */
+    }
 
-    if(H5Dclose(dataset) < 0) goto error;
+    /* Close the dataset */
+    if (H5Dclose(did) < 0)
+        goto error;
 
     /* Create a dataset in the second file */
-    if((dataset = H5Dcreate2(file2, DSET_NAME, H5T_NATIVE_INT, space,
-                             H5P_DEFAULT, dc, H5P_DEFAULT)) < 0) goto error;
+    if ((did = H5Dcreate2(fid2, DSET_NAME, H5T_NATIVE_INT, sid, H5P_DEFAULT, dcpl_id, H5P_DEFAULT)) < 0)
+        goto error;
 
     /* Write the data to the dataset */
-    if(H5Dwrite(dataset, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, points) < 0)
+    if (H5Dwrite(did, H5T_NATIVE_INT, H5S_ALL, H5S_ALL, H5P_DEFAULT, data) < 0)
         goto error;
 
-    if(H5Dclose(dataset) < 0) goto error;
+    /* Close the dataset in the second file */
+    if (H5Dclose(did) < 0)
+        goto error;
 
     /* Unregister the filter after closing all objects but before closing files. 
-     * It should flush all files. */
-    if(H5Zunregister(H5Z_FILTER_DUMMY) < 0) goto error;
+     * It should flush all files.
+     */
+    if (H5Zunregister(H5Z_FILTER_DUMMY) < 0)
+        goto error;
 
     /* Clean up objects used for this test */
-    if(H5Pclose (dc) < 0) goto error;
-    if(H5Fclose(file1) < 0) goto error;
-    if(H5Fclose(file2) < 0) goto error;
+    if (H5Pclose(dcpl_id) < 0)
+        goto error;
+    if (H5Fclose(fid1) < 0)
+        goto error;
+    if (H5Fclose(fid2) < 0)
+        goto error;
 
     PASSED();
-    return 0;
+    return SUCCEED;
 
 error:
-    return -1;
+    H5E_BEGIN_TRY {
+        H5Fclose(fid1);
+        H5Fclose(fid2);
+        H5Pclose(dcpl_id);
+        H5Pclose(gcpl_id);
+        H5Gclose(gid);
+        H5Gclose(gid_loop);
+        H5Dclose(did);
+        H5Sclose(sid);
+    } H5E_END_TRY;
+
+    return FAIL;
 }
 
 
 /*-------------------------------------------------------------------------
- * Function:	main
- *
- * Purpose:	Tests unregistering filter with H5Zunregister
+ * Function:    main
  *
- * Return:	Success:	exit(EXIT_SUCCESS)
+ * Purpose:     Tests unregistering filter with H5Zunregister
  *
- *		Failure:	exit(EXIT_FAILURE)
- *
- * Programmer:	Raymond Lu
- *              11 April 2013
+ * Return:      EXIT_SUCCESS/EXIT_FAILURE
  *
  *-------------------------------------------------------------------------
  */
 int
 main(void)
 {
-    hid_t		fapl;
-    int	nerrors = 0;
+    hid_t   fapl_id = H5I_INVALID_HID;
+    int     nerrors = 0;
 
     /* Testing setup */
     h5_reset();
-    fapl = h5_fileaccess();
+    fapl_id = h5_fileaccess();
 
     /* Test unregistering filter in its own file */
-    nerrors += (test_unregister_filters(fapl) < 0           ? 1 : 0);
+    nerrors += (test_unregister_filters(fapl_id) < 0           ? 1 : 0);
 
-    if(nerrors)
+    h5_cleanup(FILENAME, fapl_id);
+
+    if (nerrors)
         goto error;
-    printf("All filter unregistration tests passed.\n");
-    h5_cleanup(FILENAME, fapl);
+    HDprintf("All filter unregistration tests passed.\n");
 
-    return 0;
+    HDexit(EXIT_SUCCESS);
 
 error:
     nerrors = MAX(1, nerrors);
-    printf("***** %d FILTER UNREGISTRATION TEST%s FAILED! *****\n",
+    HDprintf("***** %d FILTER UNREGISTRATION TEST%s FAILED! *****\n",
             nerrors, 1 == nerrors ? "" : "S");
-    return 1;
-}
+    HDexit(EXIT_FAILURE);
+} /* end main() */
 
diff --git a/test/vol.c b/test/vol.c
index bebe2bd..5f08df3 100644
--- a/test/vol.c
+++ b/test/vol.c
@@ -29,6 +29,9 @@
 #define NATIVE_VOL_TEST_ATTRIBUTE_NAME  "test_dataset"
 #define NATIVE_VOL_TEST_HARD_LINK_NAME  "test_hard_link"
 #define NATIVE_VOL_TEST_SOFT_LINK_NAME  "test_soft_link"
+#define NATIVE_VOL_TEST_MOVE_LINK_NAME  "test_move_link"
+#define NATIVE_VOL_TEST_COPY_LINK_NAME  "test_copy_link"
+#define NATIVE_VOL_TEST_DATATYPE_NAME   "test_datatype"
 
 #define N_ELEMENTS  10
 
@@ -334,6 +337,7 @@ test_basic_group_operation(void)
 {
     hid_t fid = H5I_INVALID_HID;
     hid_t gid = H5I_INVALID_HID;
+    hid_t gid_a = H5I_INVALID_HID;
     hid_t gcpl_id = H5I_INVALID_HID;
     H5G_info_t info;
 
@@ -374,8 +378,14 @@ test_basic_group_operation(void)
     if ((gid = H5Gopen2(fid, NATIVE_VOL_TEST_GROUP_NAME, H5P_DEFAULT)) < 0)
         TEST_ERROR;
 
+    /* H5Gcreate_anon */
+    if ((gid_a = H5Gcreate_anon(fid, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+        TEST_ERROR;
+
     if (H5Gclose(gid) < 0)
         TEST_ERROR;
+    if (H5Gclose(gid_a) < 0)
+        TEST_ERROR;
     if (H5Fclose(fid) < 0)
         TEST_ERROR;
 
@@ -606,6 +616,16 @@ test_basic_attribute_operation(void)
     if (H5Aclose(aid) < 0)
         TEST_ERROR;
 
+    /* H5Aopen */
+    if ((aid = H5Aopen(fid, NATIVE_VOL_TEST_ATTRIBUTE_NAME, H5P_DEFAULT)) < 0)
+        TEST_ERROR;
+    if (H5Aclose(aid) < 0)
+        TEST_ERROR;
+
+    /* H5Adelete */
+    if (H5Adelete(fid, NATIVE_VOL_TEST_ATTRIBUTE_NAME) < 0)
+        TEST_ERROR;
+
     if (H5Fclose(fid) < 0)
         TEST_ERROR;
 
@@ -639,14 +659,40 @@ static herr_t
 test_basic_object_operation(void)
 {
     hid_t fid       = H5I_INVALID_HID;
+    hid_t gid       = H5I_INVALID_HID;
+    hid_t oid       = H5I_INVALID_HID;
+
+    H5O_info_t object_info;
 
     TESTING("Basic VOL object operations");
 
     if ((fid = H5Fcreate(NATIVE_VOL_TEST_FILENAME, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT)) < 0)
         TEST_ERROR;
+    if ((gid = H5Gcreate2(fid, NATIVE_VOL_TEST_GROUP_NAME, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+        TEST_ERROR;
+
+    /* H5Oget_info */
+    if (H5Oget_info(fid, &object_info) < 0)
+        TEST_ERROR;
+
+    /* H5Oget_info_by_name */
+    if (H5Oget_info_by_name(fid, NATIVE_VOL_TEST_GROUP_NAME, &object_info, H5P_DEFAULT) < 0)
+        TEST_ERROR;
+
+    /* H5Oexists_by_name */
+    if (H5Oexists_by_name(fid, NATIVE_VOL_TEST_GROUP_NAME, H5P_DEFAULT) != TRUE) 
+        TEST_ERROR;
+
+    /* H5Oopen/close */
+    if ((oid = H5Oopen(fid, NATIVE_VOL_TEST_GROUP_NAME, H5P_DEFAULT)) < 0) 
+        TEST_ERROR;
+    if (H5Oclose(oid) < 0)
+        TEST_ERROR;
 
     if (H5Fclose(fid) < 0)
         TEST_ERROR;
+    if (H5Gclose(gid) < 0)
+        TEST_ERROR;
 
     HDremove(NATIVE_VOL_TEST_FILENAME);
 
@@ -656,6 +702,7 @@ test_basic_object_operation(void)
 error:
     H5E_BEGIN_TRY {
         H5Fclose(fid);
+        H5Gclose(gid);
     } H5E_END_TRY;
 
     return FAIL;
@@ -676,28 +723,41 @@ static herr_t
 test_basic_link_operation(void)
 {
     hid_t fid       = H5I_INVALID_HID;
+    hid_t gid       = H5I_INVALID_HID;
 
     TESTING("Basic VOL link operations");
 
     if ((fid = H5Fcreate(NATIVE_VOL_TEST_FILENAME, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT)) < 0)
         TEST_ERROR;
+    if ((gid = H5Gcreate2(fid, NATIVE_VOL_TEST_GROUP_NAME, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT)) < 0)
+        TEST_ERROR;
 
     /* H5Lcreate_hard */
-    if (H5Lcreate_hard(fid, "/", H5L_SAME_LOC, NATIVE_VOL_TEST_HARD_LINK_NAME, H5P_DEFAULT, H5P_DEFAULT) < 0)
+    if (H5Lcreate_hard(fid, "/", gid, NATIVE_VOL_TEST_HARD_LINK_NAME, H5P_DEFAULT, H5P_DEFAULT) < 0)
         TEST_ERROR;
 
-    /* H5Lcreate_soft */
+    /* H5Lcreate_soft (to itself) */
     if (H5Lcreate_soft("/", fid, NATIVE_VOL_TEST_SOFT_LINK_NAME, H5P_DEFAULT, H5P_DEFAULT) < 0)
         TEST_ERROR;
 
     /* H5Lexists */
+    if (H5Lexists(gid, NATIVE_VOL_TEST_HARD_LINK_NAME, H5P_DEFAULT) < 0)
+        TEST_ERROR;
     if (H5Lexists(fid, NATIVE_VOL_TEST_SOFT_LINK_NAME, H5P_DEFAULT) < 0)
         TEST_ERROR;
-    if (H5Lexists(fid, NATIVE_VOL_TEST_HARD_LINK_NAME, H5P_DEFAULT) < 0)
+
+    /* H5Lcopy */
+    if (H5Lcopy(gid, NATIVE_VOL_TEST_HARD_LINK_NAME, fid, NATIVE_VOL_TEST_COPY_LINK_NAME, H5P_DEFAULT, H5P_DEFAULT) < 0)
         TEST_ERROR;
 
+    /* H5Lmove */
+//    if (H5Lmove(fid, NATIVE_VOL_TEST_COPY_LINK_NAME, gid, NATIVE_VOL_TEST_MOVE_LINK_NAME, H5P_DEFAULT, H5P_DEFAULT) < 0)
+//        TEST_ERROR;
+
     if (H5Fclose(fid) < 0)
         TEST_ERROR;
+    if (H5Gclose(gid) < 0)
+        TEST_ERROR;
 
     HDremove(NATIVE_VOL_TEST_FILENAME);
 
@@ -707,6 +767,7 @@ test_basic_link_operation(void)
 error:
     H5E_BEGIN_TRY {
         H5Fclose(fid);
+        H5Fclose(gid);
     } H5E_END_TRY;
 
     return FAIL;
@@ -727,12 +788,34 @@ static herr_t
 test_basic_datatype_operation(void)
 {
     hid_t fid       = H5I_INVALID_HID;
+    hid_t tid       = H5I_INVALID_HID;
+    hid_t tcpl_id   = H5I_INVALID_HID;
 
     TESTING("Basic VOL datatype operations");
 
     if ((fid = H5Fcreate(NATIVE_VOL_TEST_FILENAME, H5F_ACC_TRUNC, H5P_DEFAULT, H5P_DEFAULT)) < 0)
         TEST_ERROR;
+    if ((tid = H5Tcopy(H5T_NATIVE_INT)) < 0)
+        TEST_ERROR;
+
+    /* H5Tcommit */
+    if (H5Tcommit2(fid, NATIVE_VOL_TEST_DATATYPE_NAME, tid, H5P_DEFAULT, H5P_DEFAULT, H5P_DEFAULT) < 0)
+        TEST_ERROR;
+    if (H5Tclose(tid) < 0)
+        TEST_ERROR;
 
+    /* H5Topen */
+    if ((tid = H5Topen2(fid, NATIVE_VOL_TEST_DATATYPE_NAME, H5P_DEFAULT)) < 0)
+        TEST_ERROR;
+
+    /* H5Tget_create_plist */
+    if ((tcpl_id = H5Tget_create_plist(tid)) < 0)
+        TEST_ERROR;
+
+    if (H5Pclose(tcpl_id) < 0)
+        TEST_ERROR;
+    if (H5Tclose(tid) < 0)
+        TEST_ERROR;
     if (H5Fclose(fid) < 0)
         TEST_ERROR;
 
@@ -743,7 +826,9 @@ test_basic_datatype_operation(void)
 
 error:
     H5E_BEGIN_TRY {
+        H5Pclose(tcpl_id);
         H5Fclose(fid);
+        H5Tclose(tid);
     } H5E_END_TRY;
 
     return FAIL;