[svn-r22501] change the interface callbacks for the VOL to use objects pointers and public VL structure instead of IDs.

tests will fail now because of named datatypes.

1 files changed, 474 insertions, 86 deletions

diff --git a/src/H5A.c b/src/H5A.c
index df22e16..793be98 100644
--- a/src/H5A.c
+++ b/src/H5A.c
@@ -140,7 +140,7 @@ H5A_init_interface(void)
     /*
      * Create attribute ID type.
      */
-    if(H5I_register_type(H5I_ATTR, (size_t)H5I_ATTRID_HASHSIZE, H5A_RESERVED_ATOMS, (H5I_free_t)H5A_close) < H5I_FILE)
+    if(H5I_register_type(H5I_ATTR, (size_t)H5I_ATTRID_HASHSIZE, H5A_RESERVED_ATOMS, NULL) < H5I_FILE)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTINIT, FAIL, "unable to initialize interface")
 
 done:
@@ -217,8 +217,11 @@ hid_t
 H5Acreate2(hid_t loc_id, const char *attr_name, hid_t type_id, hid_t space_id,
     hid_t acpl_id, hid_t UNUSED aapl_id)
 {
+    void    *attr = NULL;       /* attr token from VOL plugin */
+    void    *obj = NULL;        /* object token of loc_id */
+    H5VL_t  *vol_plugin;        /* VOL plugin information */
     H5P_genplist_t      *plist;            /* Property list pointer */
-    H5VL_loc_params_t loc_params;
+    H5VL_loc_params_t   loc_params;
     hid_t		ret_value;              /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -234,9 +237,6 @@ H5Acreate2(hid_t loc_id, const char *attr_name, hid_t type_id, hid_t space_id,
     if(H5P_DEFAULT == acpl_id)
         acpl_id = H5P_ATTRIBUTE_CREATE_DEFAULT;
 
-    loc_params.type = H5VL_OBJECT_BY_ID;
-    loc_params.loc_data.loc_by_id.id = loc_id;
-
     /* Get the plist structure */
     if(NULL == (plist = (H5P_genplist_t *)H5I_object(acpl_id)))
         HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't find object for ID")
@@ -246,14 +246,37 @@ H5Acreate2(hid_t loc_id, const char *attr_name, hid_t type_id, hid_t space_id,
         HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't set property value for datatype id")
     if(H5P_set(plist, H5VL_ATTR_SPACE_ID, &space_id) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't set property value for space id")
-    if(H5P_set(plist, H5VL_ATTR_LOC_PARAMS, &loc_params) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't set property value for location")
+            //if(H5P_set(plist, H5VL_ATTR_LOC_PARAMS, &loc_params) < 0)
+            //HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't set property value for location")
+
+    loc_params.type = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type = H5I_get_type(loc_id);
+
+    /* get the file object */
+    if(NULL == (obj = (void *)H5I_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
+    /* get the plugin pointer */
+    if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* Create the attribute through the VOL */
-    if((ret_value = H5VL_attr_create(loc_id, attr_name, acpl_id, aapl_id, H5_REQUEST_NULL)) < 0)
+    if(NULL == (attr = H5VL_attr_create(obj, loc_params, vol_plugin, attr_name, acpl_id, aapl_id, H5_REQUEST_NULL)))
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create attribute")
 
+    /* Get an atom for the attribute */
+    if((ret_value = H5I_register(H5I_ATTR, attr, TRUE)) < 0)
+	HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to atomize attribute handle")
+
+    /* attach VOL information to the ID */
+    if (H5I_register_aux(ret_value, vol_plugin, (H5I_free2_t)H5A_close_attr) < 0)
+        HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "can't attach vol info to ID")
+
+    vol_plugin->nrefs ++;
+
 done:
+    if (ret_value < 0 && attr)
+        if(H5VL_attr_close (attr, vol_plugin, H5_REQUEST_NULL) < 0)
+            HDONE_ERROR(H5E_DATASET, H5E_CLOSEERROR, FAIL, "unable to release dataset")
     FUNC_LEAVE_API(ret_value)
 } /* H5Acreate2() */
 
@@ -294,6 +317,9 @@ H5Acreate_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
     hid_t type_id, hid_t space_id, hid_t acpl_id, hid_t aapl_id,
     hid_t lapl_id)
 {
+    void    *attr = NULL;       /* attr token from VOL plugin */
+    void    *obj = NULL;        /* object token of loc_id */
+    H5VL_t  *vol_plugin;        /* VOL plugin information */
     H5P_genplist_t      *plist;            /* Property list pointer */
     H5VL_loc_params_t    loc_params;
     hid_t		 ret_value;        /* Return value */
@@ -314,10 +340,6 @@ H5Acreate_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
     if(H5P_DEFAULT == acpl_id)
         acpl_id = H5P_ATTRIBUTE_CREATE_DEFAULT;
 
-    loc_params.type = H5VL_OBJECT_BY_NAME;
-    loc_params.loc_data.loc_by_name.name = obj_name;
-    loc_params.loc_data.loc_by_name.plist_id = lapl_id;
-
     /* Get the plist structure */
     if(NULL == (plist = (H5P_genplist_t *)H5I_object(acpl_id)))
         HGOTO_ERROR(H5E_ATOM, H5E_BADATOM, FAIL, "can't find object for ID")
@@ -327,14 +349,38 @@ H5Acreate_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
         HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't set property value for datatype id")
     if(H5P_set(plist, H5VL_ATTR_SPACE_ID, &space_id) < 0)
         HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't set property value for space id")
-    if(H5P_set(plist, H5VL_ATTR_LOC_PARAMS, &loc_params) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "can't set property value for location")
+
+    loc_params.type = H5VL_OBJECT_BY_NAME;
+    loc_params.obj_type = H5I_get_type(loc_id);
+    loc_params.loc_data.loc_by_name.name = obj_name;
+    loc_params.loc_data.loc_by_name.plist_id = lapl_id;
+
+    /* get the file object */
+    if(NULL == (obj = (void *)H5I_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
+
+    /* get the plugin pointer */
+    if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
     /* Create the attribute through the VOL */
-    if((ret_value = H5VL_attr_create(loc_id, attr_name, acpl_id, aapl_id, H5_REQUEST_NULL)) < 0)
+    if(NULL == (attr = H5VL_attr_create(obj, loc_params, vol_plugin, attr_name, acpl_id, aapl_id, H5_REQUEST_NULL)))
 	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to create attribute")
 
+    /* Get an atom for the attribute */
+    if((ret_value = H5I_register(H5I_ATTR, attr, TRUE)) < 0)
+	HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to atomize attribute handle")
+
+    /* attach VOL information to the ID */
+    if (H5I_register_aux(ret_value, vol_plugin, (H5I_free2_t)H5A_close_attr) < 0)
+        HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "can't attach vol info to ID")
+
+    vol_plugin->nrefs ++;
+
 done:
+    if (ret_value < 0 && attr)
+        if(H5VL_attr_close (attr, vol_plugin, H5_REQUEST_NULL) < 0)
+            HDONE_ERROR(H5E_DATASET, H5E_CLOSEERROR, FAIL, "unable to release dataset")
     FUNC_LEAVE_API(ret_value)
 } /* H5Acreate_by_name() */
 
@@ -361,6 +407,9 @@ done:
 hid_t
 H5Aopen(hid_t loc_id, const char *attr_name, hid_t aapl_id)
 {
+    void    *attr = NULL;       /* attr token from VOL plugin */
+    void    *obj = NULL;        /* object token of loc_id */
+    H5VL_t  *vol_plugin;        /* VOL plugin information */
     H5VL_loc_params_t loc_params; 
     hid_t		ret_value;
 
@@ -373,14 +422,35 @@ H5Aopen(hid_t loc_id, const char *attr_name, hid_t aapl_id)
     if(!attr_name || !*attr_name)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no attribute name")
 
-    loc_params.type = H5VL_OBJECT_BY_ID;
-    loc_params.loc_data.loc_by_id.id = loc_id;
+    loc_params.type = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type = H5I_get_type(loc_id);
 
-    /* Open the attribute through the VOL */
-    if((ret_value = H5VL_attr_open(loc_id, loc_params, attr_name, aapl_id, H5_REQUEST_NULL)) < 0)
-	HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, FAIL, "unable to open attribute")
+    /* get the file object */
+    if(NULL == (obj = (void *)H5I_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
+
+    /* get the plugin pointer */
+    if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
+
+    /* Create the attribute through the VOL */
+    if(NULL == (attr = H5VL_attr_open(obj, loc_params, vol_plugin, attr_name, aapl_id, H5_REQUEST_NULL)))
+	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to open attribute")
+
+    /* Get an atom for the attribute */
+    if((ret_value = H5I_register(H5I_ATTR, attr, TRUE)) < 0)
+	HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to atomize attribute handle")
+
+    /* attach VOL information to the ID */
+    if (H5I_register_aux(ret_value, vol_plugin, (H5I_free2_t)H5A_close_attr) < 0)
+        HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "can't attach vol info to ID")
+
+    vol_plugin->nrefs ++;
 
 done:
+    if (ret_value < 0 && attr)
+        if(H5VL_attr_close (attr, vol_plugin, H5_REQUEST_NULL) < 0)
+            HDONE_ERROR(H5E_DATASET, H5E_CLOSEERROR, FAIL, "unable to release dataset")
     FUNC_LEAVE_API(ret_value)
 } /* H5Aopen() */
 
@@ -410,6 +480,9 @@ hid_t
 H5Aopen_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
     hid_t aapl_id, hid_t lapl_id)
 {
+    void    *attr = NULL;       /* attr token from VOL plugin */
+    void    *obj = NULL;        /* object token of loc_id */
+    H5VL_t  *vol_plugin;        /* VOL plugin information */
     H5VL_loc_params_t   loc_params;
     hid_t		ret_value;
 
@@ -432,12 +505,34 @@ H5Aopen_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
     loc_params.type = H5VL_OBJECT_BY_NAME;
     loc_params.loc_data.loc_by_name.name = obj_name;
     loc_params.loc_data.loc_by_name.plist_id = lapl_id;
+    loc_params.obj_type = H5I_get_type(loc_id);
 
-    /* Open the attribute through the VOL */
-    if((ret_value = H5VL_attr_open(loc_id, loc_params, attr_name, aapl_id, H5_REQUEST_NULL)) < 0)
-	HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, FAIL, "unable to open attribute")
+    /* get the file object */
+    if(NULL == (obj = (void *)H5I_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
+
+    /* get the plugin pointer */
+    if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
+
+    /* Create the attribute through the VOL */
+    if(NULL == (attr = H5VL_attr_open(obj, loc_params, vol_plugin, attr_name, aapl_id, H5_REQUEST_NULL)))
+	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to open attribute")
+
+    /* Get an atom for the attribute */
+    if((ret_value = H5I_register(H5I_ATTR, attr, TRUE)) < 0)
+	HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to atomize attribute handle")
+
+    /* attach VOL information to the ID */
+    if (H5I_register_aux(ret_value, vol_plugin, (H5I_free2_t)H5A_close_attr) < 0)
+        HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "can't attach vol info to ID")
+
+    vol_plugin->nrefs ++;
 
 done:
+    if (ret_value < 0 && attr)
+        if(H5VL_attr_close (attr, vol_plugin, H5_REQUEST_NULL) < 0)
+            HDONE_ERROR(H5E_DATASET, H5E_CLOSEERROR, FAIL, "unable to release dataset")
     FUNC_LEAVE_API(ret_value)
 } /* H5Aopen_by_name() */
 
@@ -468,8 +563,12 @@ done:
 --------------------------------------------------------------------------*/
 hid_t
 H5Aopen_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
-    H5_iter_order_t order, hsize_t n, hid_t UNUSED aapl_id, hid_t lapl_id)
+    H5_iter_order_t order, hsize_t n, hid_t aapl_id, hid_t lapl_id)
 {
+    void    *attr = NULL;       /* attr token from VOL plugin */
+    void    *obj = NULL;        /* object token of loc_id */
+    H5VL_t  *vol_plugin;        /* VOL plugin information */
+    H5VL_loc_params_t   loc_params;
     hid_t	ret_value;      /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -491,11 +590,40 @@ H5Aopen_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
         if(TRUE != H5P_isa_class(lapl_id, H5P_LINK_ACCESS))
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not link access property list ID")
 
-    if(H5VL_object_misc(loc_id, H5VL_ATTR_OPEN_BY_IDX, H5_REQUEST_NULL, &ret_value, 
-                         obj_name, idx_type, order, n, aapl_id, lapl_id) < 0)
-        HGOTO_ERROR(H5E_INTERNAL, H5E_CANTINIT, FAIL, "unable to open attribute")
+    loc_params.type = H5VL_OBJECT_BY_IDX;
+    loc_params.loc_data.loc_by_idx.name = obj_name;
+    loc_params.loc_data.loc_by_idx.idx_type = idx_type;
+    loc_params.loc_data.loc_by_idx.order = order;
+    loc_params.loc_data.loc_by_idx.n = n;
+    loc_params.loc_data.loc_by_idx.plist_id = lapl_id;
+    loc_params.obj_type = H5I_get_type(loc_id);
+
+    /* get the file object */
+    if(NULL == (obj = (void *)H5I_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
+
+    /* get the plugin pointer */
+    if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
+
+    /* Create the attribute through the VOL */
+    if(NULL == (attr = H5VL_attr_open(obj, loc_params, vol_plugin, NULL, aapl_id, H5_REQUEST_NULL)))
+	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to open attribute")
+
+    /* Get an atom for the attribute */
+    if((ret_value = H5I_register(H5I_ATTR, attr, TRUE)) < 0)
+	HGOTO_ERROR(H5E_ATOM, H5E_CANTREGISTER, FAIL, "unable to atomize attribute handle")
+
+    /* attach VOL information to the ID */
+    if (H5I_register_aux(ret_value, vol_plugin, (H5I_free2_t)H5A_close_attr) < 0)
+        HGOTO_ERROR(H5E_VOL, H5E_CANTINIT, FAIL, "can't attach vol info to ID")
+
+    vol_plugin->nrefs ++;
 
 done:
+    if (ret_value < 0 && attr)
+        if(H5VL_attr_close (attr, vol_plugin, H5_REQUEST_NULL) < 0)
+            HDONE_ERROR(H5E_DATASET, H5E_CLOSEERROR, FAIL, "unable to release dataset")
     FUNC_LEAVE_API(ret_value)
 } /* H5Aopen_by_idx() */
 
@@ -519,6 +647,8 @@ done:
 herr_t
 H5Awrite(hid_t attr_id, hid_t dtype_id, const void *buf)
 {
+    H5VL_t     *vol_plugin;
+    void       *attr;
     herr_t ret_value;           /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -528,8 +658,15 @@ H5Awrite(hid_t attr_id, hid_t dtype_id, const void *buf)
     if(NULL == buf)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "null attribute buffer")
 
+    /* get the plugin pointer */
+    if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(attr_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
+    /* get the dataset object */
+    if(NULL == (attr = (void *)H5I_object(attr_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid attribute identifier")
+
     /* write the data through the VOL */
-    if((ret_value = H5VL_attr_write(attr_id, dtype_id, buf, H5_REQUEST_NULL)) < 0)
+    if((ret_value = H5VL_attr_write(attr, vol_plugin, dtype_id, buf, H5_REQUEST_NULL)) < 0)
 	HGOTO_ERROR(H5E_ATTR, H5E_READERROR, FAIL, "can't read data")
 
 done:
@@ -556,6 +693,8 @@ done:
 herr_t
 H5Aread(hid_t attr_id, hid_t dtype_id, void *buf)
 {
+    H5VL_t     *vol_plugin;
+    void       *attr;
     herr_t ret_value;           /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -565,8 +704,15 @@ H5Aread(hid_t attr_id, hid_t dtype_id, void *buf)
     if(NULL == buf)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "null attribute buffer")
 
+    /* get the plugin pointer */
+    if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(attr_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
+    /* get the dataset object */
+    if(NULL == (attr = (void *)H5I_object(attr_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid attribute identifier")
+
     /* Read the data through the VOL */
-    if((ret_value = H5VL_attr_read(attr_id, dtype_id, buf, H5_REQUEST_NULL)) < 0)
+    if((ret_value = H5VL_attr_read(attr, vol_plugin, dtype_id, buf, H5_REQUEST_NULL)) < 0)
 	HGOTO_ERROR(H5E_ATTR, H5E_READERROR, FAIL, "can't read data")
 
 done:
@@ -593,13 +739,22 @@ done:
 hid_t
 H5Aget_space(hid_t attr_id)
 {
+    H5VL_t     *vol_plugin;
+    void       *attr;
     hid_t	ret_value;
 
     FUNC_ENTER_API(FAIL)
     H5TRACE1("i", "i", attr_id);
 
+    /* get the plugin pointer */
+    if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(attr_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
+    /* get the dataset object */
+    if(NULL == (attr = (void *)H5I_object(attr_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid attribute identifier")
+
     /* get the dataspace through the VOL */
-    if(H5VL_attr_get(attr_id, H5VL_ATTR_GET_SPACE, H5_REQUEST_NULL, &ret_value) < 0)
+    if(H5VL_attr_get(attr, vol_plugin, H5VL_ATTR_GET_SPACE, H5_REQUEST_NULL, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get data space")
 
 done:
@@ -626,13 +781,22 @@ done:
 hid_t
 H5Aget_type(hid_t attr_id)
 {
+    H5VL_t     *vol_plugin;
+    void       *attr;
     hid_t	 ret_value;     /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE1("i", "i", attr_id);
 
+    /* get the plugin pointer */
+    if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(attr_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
+    /* get the dataset object */
+    if(NULL == (attr = (void *)H5I_object(attr_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid attribute identifier")
+
     /* get the datatype through the VOL */
-    if(H5VL_attr_get(attr_id, H5VL_ATTR_GET_TYPE, H5_REQUEST_NULL, &ret_value) < 0)
+    if(H5VL_attr_get(attr, vol_plugin, H5VL_ATTR_GET_TYPE, H5_REQUEST_NULL, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get type")
 
 done:
@@ -662,15 +826,24 @@ done:
 hid_t
 H5Aget_create_plist(hid_t attr_id)
 {
-    hid_t		ret_value;
+    H5VL_t     *vol_plugin;
+    void       *attr;
+    hid_t	ret_value;
 
     FUNC_ENTER_API(FAIL)
     H5TRACE1("i", "i", attr_id);
 
     HDassert(H5P_LST_ATTRIBUTE_CREATE_g != -1);
 
+    /* get the plugin pointer */
+    if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(attr_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
+    /* get the dataset object */
+    if(NULL == (attr = (void *)H5I_object(attr_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid attribute identifier")
+
     /* get the acpl through the VOL */
-    if(H5VL_attr_get(attr_id, H5VL_ATTR_GET_ACPL, H5_REQUEST_NULL, &ret_value) < 0)
+    if(H5VL_attr_get(attr, vol_plugin, H5VL_ATTR_GET_ACPL, H5_REQUEST_NULL, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get acpl")
 
 done:
@@ -702,7 +875,10 @@ done:
 ssize_t
 H5Aget_name(hid_t attr_id, size_t buf_size, char *buf)
 {
-    ssize_t		ret_value;
+    H5VL_t     *vol_plugin;
+    void       *attr;
+    H5VL_loc_params_t loc_params;
+    ssize_t	ret_value;
 
     FUNC_ENTER_API(FAIL)
     H5TRACE3("Zs", "iz*s", attr_id, buf_size, buf);
@@ -711,8 +887,18 @@ H5Aget_name(hid_t attr_id, size_t buf_size, char *buf)
     if(!buf && buf_size)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid buffer")
 
+    loc_params.type = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type = H5I_get_type(attr_id);
+
+    /* get the plugin pointer */
+    if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(attr_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
+    /* get the dataset object */
+    if(NULL == (attr = (void *)H5I_object(attr_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid attribute identifier")
+
     /* get the name through the VOL */
-    if(H5VL_attr_get(attr_id, H5VL_ATTR_GET_NAME, H5_REQUEST_NULL, &ret_value, buf_size, buf) < 0)
+    if(H5VL_attr_get(attr, vol_plugin, H5VL_ATTR_GET_NAME, H5_REQUEST_NULL, loc_params, buf_size, buf, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get name")
 
 done:
@@ -742,7 +928,9 @@ H5Aget_name_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
     H5_iter_order_t order, hsize_t n, char *name /*out*/, size_t size,
     hid_t lapl_id)
 {
-    hid_t       attr_id = -1;
+    H5VL_t     *vol_plugin;
+    void       *obj;
+    H5VL_loc_params_t loc_params;
     ssize_t	ret_value;      /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -764,6 +952,26 @@ H5Aget_name_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
         if(TRUE != H5P_isa_class(lapl_id, H5P_LINK_ACCESS))
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not link access property list ID")
 
+    /* get the plugin pointer */
+    if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
+    /* get the dataset object */
+    if(NULL == (obj = (void *)H5I_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid object identifier")
+
+    loc_params.type = H5VL_OBJECT_BY_IDX;
+    loc_params.loc_data.loc_by_idx.name = obj_name;
+    loc_params.loc_data.loc_by_idx.idx_type = idx_type;
+    loc_params.loc_data.loc_by_idx.order = order;
+    loc_params.loc_data.loc_by_idx.n = n;
+    loc_params.loc_data.loc_by_idx.plist_id = lapl_id;
+    loc_params.obj_type = H5I_get_type(loc_id);
+
+    /* get the name through the VOL */
+    if(H5VL_attr_get(obj, vol_plugin, H5VL_ATTR_GET_NAME, H5_REQUEST_NULL, loc_params, size, name, &ret_value) < 0)
+        HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get name")
+
+#if 0
     if(H5VL_object_misc(loc_id, H5VL_ATTR_OPEN_BY_IDX, H5_REQUEST_NULL, &attr_id, 
                          obj_name, idx_type, order, n, H5P_DEFAULT, lapl_id) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTINIT, FAIL, "unable to open attribute")
@@ -771,28 +979,9 @@ H5Aget_name_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
     /* get the name through the VOL */
     if(H5VL_attr_get(attr_id, H5VL_ATTR_GET_NAME, H5_REQUEST_NULL, &ret_value, size, name) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get name")
-
-#if 0
-    /* Open the attribute on the object header */
-    if(NULL == (attr = H5A_open_by_idx(&loc, obj_name, idx_type, order, n, lapl_id, H5AC_ind_dxpl_id)))
-        HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "can't open attribute")
-
-    /* Get the length of the name */
-    ret_value = (ssize_t)HDstrlen(attr->shared->name);
-
-    /* Copy the name into the user's buffer, if given */
-    if(name) {
-        HDstrncpy(name, attr->shared->name, MIN((size_t)(ret_value + 1), size));
-        if((size_t)ret_value >= size)
-            name[size - 1]='\0';
-    } /* end if */
 #endif
 
 done:
-    /* Release resources */
-    if(attr_id > 0 && H5VL_attr_close(attr_id, H5_REQUEST_NULL) < 0)
-        HDONE_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
-
     FUNC_LEAVE_API(ret_value)
 } /* end H5Aget_name_by_idx() */
 
@@ -817,13 +1006,22 @@ done:
 hsize_t
 H5Aget_storage_size(hid_t attr_id)
 {
+    H5VL_t     *vol_plugin;
+    void       *attr;
     hsize_t	ret_value;      /* Return value */
 
     FUNC_ENTER_API(0)
     H5TRACE1("h", "i", attr_id);
 
+    /* get the plugin pointer */
+    if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(attr_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "ID does not contain VOL information")
+    /* get the dataset object */
+    if(NULL == (attr = (void *)H5I_object(attr_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "invalid attribute identifier")
+
     /* get the storage size through the VOL */
-    if(H5VL_attr_get(attr_id, H5VL_ATTR_GET_STORAGE_SIZE, H5_REQUEST_NULL, &ret_value) < 0)
+    if(H5VL_attr_get(attr, vol_plugin, H5VL_ATTR_GET_STORAGE_SIZE, H5_REQUEST_NULL, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, 0, "unable to get acpl")
 
 done:
@@ -847,13 +1045,26 @@ done:
 herr_t
 H5Aget_info(hid_t attr_id, H5A_info_t *ainfo)
 {
+    H5VL_t     *vol_plugin;
+    void       *attr;
+    H5VL_loc_params_t loc_params;
     herr_t	ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE2("e", "i*x", attr_id, ainfo);
 
+    /* get the plugin pointer */
+    if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(attr_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
+    /* get the dataset object */
+    if(NULL == (attr = (void *)H5I_object(attr_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid attribute identifier")
+
+    loc_params.type = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type = H5I_get_type(attr_id);
+
     /* get the attribute info through the VOL */
-    if(H5VL_attr_get(attr_id, H5VL_ATTR_GET_INFO, H5_REQUEST_NULL, ainfo) < 0)
+    if(H5VL_attr_get(attr, vol_plugin, H5VL_ATTR_GET_INFO, H5_REQUEST_NULL, loc_params, ainfo) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get attribute info")
 
 done:
@@ -878,8 +1089,9 @@ herr_t
 H5Aget_info_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
     H5A_info_t *ainfo, hid_t lapl_id)
 {
+    H5VL_t     *vol_plugin;
+    void       *obj;
     H5VL_loc_params_t   loc_params;
-    hid_t attr_id = -1;
     herr_t	ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -903,7 +1115,20 @@ H5Aget_info_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
     loc_params.type = H5VL_OBJECT_BY_NAME;
     loc_params.loc_data.loc_by_name.name = obj_name;
     loc_params.loc_data.loc_by_name.plist_id = lapl_id;
+    loc_params.obj_type = H5I_get_type(loc_id);
+
+    /* get the plugin pointer */
+    if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
+    /* get the dataset object */
+    if(NULL == (obj = (void *)H5I_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid object identifier")
 
+    /* get the attribute info through the VOL */
+    if(H5VL_attr_get(obj, vol_plugin, H5VL_ATTR_GET_INFO, H5_REQUEST_NULL, loc_params, ainfo, attr_name) < 0)
+        HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get attribute info")
+
+#if 0
     /* Open the attribute through the VOL */
     if((attr_id = H5VL_attr_open(loc_id, loc_params, attr_name, H5P_DEFAULT, H5_REQUEST_NULL)) < 0)
 	HGOTO_ERROR(H5E_ATTR, H5E_CANTINIT, FAIL, "unable to open attribute")
@@ -911,11 +1136,14 @@ H5Aget_info_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
     /* get the attribute info through the VOL */
     if(H5VL_attr_get(attr_id, H5VL_ATTR_GET_INFO, H5_REQUEST_NULL, ainfo) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get attribute info")
-done:
+
     /* release resources */
     if(attr_id > 0 && H5VL_attr_close(attr_id, H5_REQUEST_NULL) < 0)
         HDONE_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
 
+#endif
+
+done:
     FUNC_LEAVE_API(ret_value)
 } /* end H5Aget_info_by_name() */
 
@@ -938,7 +1166,9 @@ herr_t
 H5Aget_info_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
     H5_iter_order_t order, hsize_t n, H5A_info_t *ainfo, hid_t lapl_id)
 {
-    hid_t attr_id = FAIL;
+    H5VL_t     *vol_plugin;
+    void       *obj;
+    H5VL_loc_params_t   loc_params;
     herr_t	ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -962,6 +1192,26 @@ H5Aget_info_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
         if(TRUE != H5P_isa_class(lapl_id, H5P_LINK_ACCESS))
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not link access property list ID")
 
+    loc_params.type = H5VL_OBJECT_BY_IDX;
+    loc_params.loc_data.loc_by_idx.name = obj_name;
+    loc_params.loc_data.loc_by_idx.idx_type = idx_type;
+    loc_params.loc_data.loc_by_idx.order = order;
+    loc_params.loc_data.loc_by_idx.n = n;
+    loc_params.loc_data.loc_by_idx.plist_id = lapl_id;
+    loc_params.obj_type = H5I_get_type(loc_id);
+
+    /* get the plugin pointer */
+    if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
+    /* get the dataset object */
+    if(NULL == (obj = (void *)H5I_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid object identifier")
+
+    /* get the attribute info through the VOL */
+    if(H5VL_attr_get(obj, vol_plugin, H5VL_ATTR_GET_INFO, H5_REQUEST_NULL, 
+                     loc_params, ainfo) < 0)
+        HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get attribute info")
+
 #if 0
     /* Open the attribute on the object header */
     if(NULL == (attr = H5A_open_by_idx(&loc, obj_name, idx_type, order, n, lapl_id, H5AC_ind_dxpl_id)))
@@ -970,7 +1220,6 @@ H5Aget_info_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
     /* Get the attribute information */
     if(H5A_get_info(attr, ainfo) < 0)
 	HGOTO_ERROR(H5E_ATTR, H5E_CANTGET, FAIL, "unable to get attribute info")
-#endif
 
     /* open the attribute through the VOL */
     if(H5VL_object_misc(loc_id, H5VL_ATTR_OPEN_BY_IDX, H5_REQUEST_NULL, &attr_id, 
@@ -981,11 +1230,12 @@ H5Aget_info_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
     if(H5VL_attr_get(attr_id, H5VL_ATTR_GET_INFO, H5_REQUEST_NULL, ainfo) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get attribute info")
 
-done:
     /* Release resources */
     if(attr_id && H5VL_attr_close(attr_id, H5_REQUEST_NULL) < 0)
         HDONE_ERROR(H5E_ATTR, H5E_CANTFREE, FAIL, "can't close attribute")
+#endif
 
+done:
     FUNC_LEAVE_API(ret_value)
 } /* end H5Aget_info_by_idx() */
 
@@ -1019,13 +1269,23 @@ H5Arename(hid_t loc_id, const char *old_name, const char *new_name)
 
     /* Avoid thrashing things if the names are the same */
     if(HDstrcmp(old_name, new_name)) {
+        H5VL_t     *vol_plugin;
+        void       *obj;
         H5VL_loc_params_t loc_params;
 
-        loc_params.type = H5VL_OBJECT_BY_ID;
-        loc_params.loc_data.loc_by_id.id = loc_id;
+        loc_params.type = H5VL_OBJECT_BY_SELF;
+        loc_params.obj_type = H5I_get_type(loc_id);
+
+        /* get the file object */
+        if(NULL == (obj = (void *)H5I_object(loc_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
+        /* get the plugin pointer */
+        if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(loc_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
         /* rename the attribute info through the VOL */
-        if(H5VL_object_misc(loc_id, H5VL_ATTR_RENAME, H5_REQUEST_NULL, loc_params, old_name, new_name) < 0)
+        if(H5VL_object_misc(obj, loc_params, vol_plugin, H5VL_ATTR_RENAME, H5_REQUEST_NULL, 
+                            old_name, new_name) < 0)
             HGOTO_ERROR(H5E_ATTR, H5E_CANTRENAME, FAIL, "can't rename attribute")
     }
 done:
@@ -1073,15 +1333,26 @@ H5Arename_by_name(hid_t loc_id, const char *obj_name, const char *old_attr_name,
 
     /* Avoid thrashing things if the names are the same */
     if(HDstrcmp(old_attr_name, new_attr_name)) {
+        H5VL_t     *vol_plugin;
+        void       *obj;
         H5VL_loc_params_t loc_params;
 
         loc_params.type = H5VL_OBJECT_BY_NAME;
         loc_params.loc_data.loc_by_name.name = obj_name;
         loc_params.loc_data.loc_by_name.plist_id = lapl_id;
+        loc_params.obj_type = H5I_get_type(loc_id);
+
+        /* get the file object */
+        if(NULL == (obj = (void *)H5I_object(loc_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid file identifier")
+        /* get the plugin pointer */
+        if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(loc_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
 
-        /* get the attribute info through the VOL */
-        if(H5VL_object_misc(loc_id, H5VL_ATTR_RENAME, H5_REQUEST_NULL, loc_params, old_attr_name, new_attr_name) < 0)
-            HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get attribute info")
+        /* rename the attribute info through the VOL */
+        if(H5VL_object_misc(obj, loc_params, vol_plugin, H5VL_ATTR_RENAME, H5_REQUEST_NULL, 
+                            old_attr_name, new_attr_name) < 0)
+            HGOTO_ERROR(H5E_ATTR, H5E_CANTRENAME, FAIL, "can't rename attribute")
     } /* end if */
 
 done:
@@ -1216,11 +1487,15 @@ H5Aiterate_by_name(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
     H5_iter_order_t order, hsize_t *idx, H5A_operator2_t op, void *op_data,
     hid_t lapl_id)
 {
+    H5G_loc_t	loc;	        /* Object location */
+    H5G_loc_t   obj_loc;        /* Location used to open group */
+    H5G_name_t  obj_path;       /* Opened object group hier. path */
+    H5O_loc_t   obj_oloc;       /* Opened object object location */
+    hbool_t     loc_found = FALSE;      /* Entry at 'obj_name' found */
     hid_t       obj_loc_id = (-1);      /* ID for object located */
     H5A_attr_iter_op_t attr_op; /* Attribute operator */
     hsize_t	start_idx;      /* Index of attribute to start iterating at */
     hsize_t	last_attr;      /* Index of last attribute examined */
-    H5VL_loc_params_t loc_params;
     herr_t	ret_value;      /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -1230,6 +1505,8 @@ H5Aiterate_by_name(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
     /* 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(!obj_name || !*obj_name)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no object name")
     if(idx_type <= H5_INDEX_UNKNOWN || idx_type >= H5_INDEX_N)
@@ -1242,13 +1519,19 @@ H5Aiterate_by_name(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
         if(TRUE != H5P_isa_class(lapl_id, H5P_LINK_ACCESS))
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not link access property list ID")
 
-    loc_params.type = H5VL_OBJECT_BY_NAME;
-    loc_params.loc_data.loc_by_name.name = obj_name;
-    loc_params.loc_data.loc_by_name.plist_id = lapl_id;
+    /* Set up opened group location to fill in */
+    obj_loc.oloc = &obj_oloc;
+    obj_loc.path = &obj_path;
+    H5G_loc_reset(&obj_loc);
 
-    /* Open the object through the VOL */
-    if((obj_loc_id = H5VL_object_open(loc_id, loc_params, H5_REQUEST_NULL)) < 0)
-	HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to open object")
+    /* Find the object's location */
+    if(H5G_loc_find(&loc, obj_name, &obj_loc/*out*/, lapl_id, H5AC_ind_dxpl_id) < 0)
+        HGOTO_ERROR(H5E_ATTR, H5E_NOTFOUND, FAIL, "object not found")
+    loc_found = TRUE;
+
+    /* Open the object */
+    if((obj_loc_id = H5O_open_by_loc(&obj_loc, lapl_id, H5AC_ind_dxpl_id, TRUE)) < 0)
+        HGOTO_ERROR(H5E_ATTR, H5E_CANTOPENOBJ, FAIL, "unable to open object")
 
     /* Build attribute operator info */
     attr_op.op_type = H5A_ATTR_OP_APP2;
@@ -1269,6 +1552,8 @@ done:
         if(H5I_dec_app_ref(obj_loc_id) < 0)
             HDONE_ERROR(H5E_ATTR, H5E_CANTDEC, FAIL, "unable to close temporary object")
     } /* end if */
+    else if(loc_found && H5G_loc_free(&obj_loc) < 0)
+        HDONE_ERROR(H5E_ATTR, H5E_CANTRELEASE, FAIL, "can't free location")
 
     FUNC_LEAVE_API(ret_value)
 } /* H5Aiterate_by_name() */
@@ -1291,6 +1576,8 @@ done:
 herr_t
 H5Adelete(hid_t loc_id, const char *name)
 {
+    H5VL_t     *vol_plugin;
+    void       *obj;
     H5VL_loc_params_t loc_params;
     herr_t	ret_value = SUCCEED;    /* Return value */
 
@@ -1303,11 +1590,18 @@ H5Adelete(hid_t loc_id, const char *name)
     if(!name || !*name)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name")
 
-    loc_params.type = H5VL_OBJECT_BY_ID;
-    loc_params.loc_data.loc_by_id.id = loc_id;
+    loc_params.type = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type = H5I_get_type(loc_id);
+
+    /* get the plugin pointer */
+    if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
+    /* get the dataset object */
+    if(NULL == (obj = (void *)H5I_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid object identifier")
 
     /* Open the attribute through the VOL */
-    if(H5VL_attr_remove(loc_id, loc_params, name, H5_REQUEST_NULL) < 0)
+    if(H5VL_attr_remove(obj, loc_params, vol_plugin, name, H5_REQUEST_NULL) < 0)
 	HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete attribute")
 
 done:
@@ -1335,6 +1629,8 @@ herr_t
 H5Adelete_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
     hid_t lapl_id)
 {
+    H5VL_t     *vol_plugin;
+    void       *obj;
     H5VL_loc_params_t loc_params;
     herr_t	ret_value = SUCCEED;    /* Return value */
 
@@ -1357,9 +1653,17 @@ H5Adelete_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
     loc_params.type = H5VL_OBJECT_BY_NAME;
     loc_params.loc_data.loc_by_name.name = obj_name;
     loc_params.loc_data.loc_by_name.plist_id = lapl_id;
+    loc_params.obj_type = H5I_get_type(loc_id);
+
+    /* get the plugin pointer */
+    if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
+    /* get the dataset object */
+    if(NULL == (obj = (void *)H5I_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid object identifier")
 
     /* Open the attribute through the VOL */
-    if(H5VL_attr_remove(loc_id, loc_params, attr_name, H5_REQUEST_NULL) < 0)
+    if(H5VL_attr_remove(obj, loc_params, vol_plugin, attr_name, H5_REQUEST_NULL) < 0)
 	HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete attribute")
 
 done:
@@ -1395,6 +1699,8 @@ herr_t
 H5Adelete_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
     H5_iter_order_t order, hsize_t n, hid_t lapl_id)
 {
+    H5VL_t     *vol_plugin;
+    void       *obj;
     H5VL_loc_params_t loc_params;
     herr_t	ret_value = SUCCEED;    /* Return value */
 
@@ -1416,6 +1722,26 @@ H5Adelete_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
         if(TRUE != H5P_isa_class(lapl_id, H5P_LINK_ACCESS))
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not link access property list ID")
 
+    loc_params.type = H5VL_OBJECT_BY_IDX;
+    loc_params.loc_data.loc_by_idx.name = obj_name;
+    loc_params.loc_data.loc_by_idx.idx_type = idx_type;
+    loc_params.loc_data.loc_by_idx.order = order;
+    loc_params.loc_data.loc_by_idx.n = n;
+    loc_params.loc_data.loc_by_idx.plist_id = lapl_id;
+    loc_params.obj_type = H5I_get_type(loc_id);
+
+    /* get the plugin pointer */
+    if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
+    /* get the dataset object */
+    if(NULL == (obj = (void *)H5I_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid object identifier")
+
+    /* Open the attribute through the VOL */
+    if(H5VL_attr_remove(obj, loc_params, vol_plugin, NULL, H5_REQUEST_NULL) < 0)
+	HGOTO_ERROR(H5E_ATTR, H5E_CANTDELETE, FAIL, "unable to delete attribute")
+
+#if 0
     loc_params.type = H5VL_OBJECT_BY_NAME;
     loc_params.loc_data.loc_by_name.name = obj_name;
     loc_params.loc_data.loc_by_name.plist_id = lapl_id;
@@ -1424,6 +1750,7 @@ H5Adelete_by_idx(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
     if(H5VL_object_misc(loc_id, H5VL_ATTR_DELETE_BY_IDX, H5_REQUEST_NULL, loc_params, 
                         idx_type, order, n) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get attribute info")
+#endif
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -1453,9 +1780,13 @@ H5Aclose(hid_t attr_id)
     FUNC_ENTER_API(FAIL)
     H5TRACE1("e", "i", attr_id);
 
-    /* Close the attribute through the VOL */
-    if((ret_value = H5VL_attr_close(attr_id, H5_REQUEST_NULL)) < 0)
-	HGOTO_ERROR(H5E_ATTR, H5E_CANTRELEASE, FAIL, "unable to close attribute")
+    /* check arguments */
+    if(NULL == H5I_object_verify(attr_id, H5I_ATTR))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not an attribute")
+
+    /* Decrement references to that atom (and close it) */
+    if(H5I_dec_app_ref(attr_id) < 0)
+        HGOTO_ERROR(H5E_ATTR, H5E_CANTDEC, FAIL, "can't close attribute")
 
 done:
     FUNC_LEAVE_API(ret_value)
@@ -1479,6 +1810,8 @@ done:
 htri_t
 H5Aexists(hid_t obj_id, const char *attr_name)
 {
+    H5VL_t     *vol_plugin;
+    void       *obj;
     H5VL_loc_params_t loc_params;
     htri_t	ret_value;              /* Return value */
 
@@ -1491,11 +1824,18 @@ H5Aexists(hid_t obj_id, const char *attr_name)
     if(!attr_name || !*attr_name)
 	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no attribute name")
 
-    loc_params.type = H5VL_OBJECT_BY_ID;
-    loc_params.loc_data.loc_by_id.id = obj_id;
+    /* get the plugin pointer */
+    if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(obj_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
+    /* get the dataset object */
+    if(NULL == (obj = (void *)H5I_object(obj_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid object identifier")
+
+    loc_params.type = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type = H5I_get_type(obj_id);
 
     /* get the attribute info through the VOL */
-    if(H5VL_attr_get(obj_id, H5VL_ATTR_EXISTS, H5_REQUEST_NULL, attr_name, loc_params, &ret_value) < 0)
+    if(H5VL_attr_get(obj, vol_plugin, H5VL_ATTR_EXISTS, H5_REQUEST_NULL, loc_params, attr_name, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get attribute info")
 
 done:
@@ -1520,6 +1860,8 @@ htri_t
 H5Aexists_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
     hid_t lapl_id)
 {
+    H5VL_t     *vol_plugin;
+    void       *obj;
     H5VL_loc_params_t loc_params;
     htri_t	ret_value;              /* Return value */
 
@@ -1539,14 +1881,60 @@ H5Aexists_by_name(hid_t loc_id, const char *obj_name, const char *attr_name,
         if(TRUE != H5P_isa_class(lapl_id, H5P_LINK_ACCESS))
             HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not link access property list ID")
 
+    /* get the plugin pointer */
+    if (NULL == (vol_plugin = (H5VL_t *)H5I_get_aux(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID does not contain VOL information")
+    /* get the dataset object */
+    if(NULL == (obj = (void *)H5I_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid object identifier")
+
     loc_params.type = H5VL_OBJECT_BY_NAME;
     loc_params.loc_data.loc_by_name.name = obj_name;
     loc_params.loc_data.loc_by_name.plist_id = lapl_id;
+    loc_params.obj_type = H5I_get_type(loc_id);
 
     /* get the attribute info through the VOL */
-    if(H5VL_attr_get(loc_id, H5VL_ATTR_EXISTS, H5_REQUEST_NULL, attr_name, loc_params, &ret_value) < 0)
+    if(H5VL_attr_get(obj, vol_plugin, H5VL_ATTR_EXISTS, H5_REQUEST_NULL, loc_params, attr_name, &ret_value) < 0)
         HGOTO_ERROR(H5E_INTERNAL, H5E_CANTGET, FAIL, "unable to get attribute info")
 
 done:
     FUNC_LEAVE_API(ret_value)
 } /* H5Aexists_by_name() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5A_close_attr
+ *
+ * Purpose:	Called when the ref count reaches zero on the attr_id
+ *
+ * Return:	Success:	Non-negative
+ *
+ *		Failure:	Negative
+ *
+ * Programmer:	Mohamad Chaarawi
+ *              June 2012
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5A_close_attr(void *attr, H5VL_t *vol_plugin)
+{
+    herr_t              ret_value = SUCCEED;    /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT
+
+    /* Close the attr through the VOL*/
+    if((ret_value = H5VL_attr_close(attr, vol_plugin, H5_REQUEST_NULL)) < 0)
+	HGOTO_ERROR(H5E_ATTR, H5E_CLOSEERROR, FAIL, "unable to close attribute")
+
+    vol_plugin->nrefs --;
+    if (0 == vol_plugin->nrefs) {
+        if (NULL != vol_plugin->container_name)
+            H5MM_xfree(vol_plugin->container_name);
+        if (NULL != vol_plugin)
+            H5MM_free(vol_plugin);
+    }
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5A_close_attr() */