Merge all of my changes from merge-back-to-feature-vfd_swmr-attempt-1,

including the merge of `hdffv/hdf5/develop`, back to the branch that Vailin and
I share.

Now I need to put this branch on a fork with a less confusing name than
vchoi_fork!

1 files changed, 423 insertions, 132 deletions

diff --git a/src/H5O.c b/src/H5O.c
index b33e6e2..ffb49d9 100644
--- a/src/H5O.c
+++ b/src/H5O.c
@@ -38,6 +38,8 @@
 #include "H5Lprivate.h"         /* Links                                    */
 #include "H5Opkg.h"             /* Object headers                           */
 
+#include "H5VLnative_private.h" /* Native VOL connector                     */
+
 
 /****************/
 /* Local Macros */
@@ -100,15 +102,16 @@
 hid_t
 H5Oopen(hid_t loc_id, const char *name, hid_t lapl_id)
 {
-    H5G_loc_t	loc;                    /* Location of group */
+    H5VL_object_t *vol_obj;             /* Object token of loc_id */
+    H5I_type_t      opened_type;
+    void           *opened_obj  = NULL;
+    H5VL_loc_params_t loc_params;
     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, H5I_INVALID_HID, "not a location")
     if(!name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "name parameter cannot be NULL")
     if(!*name)
@@ -118,10 +121,24 @@ H5Oopen(hid_t loc_id, const char *name, hid_t lapl_id)
     if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, FALSE) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, H5I_INVALID_HID, "can't set access property list info")
 
+    /* Get the location object */
+    if(NULL == (vol_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 */
-    if((ret_value = H5O_open_name(&loc, name, TRUE)) < 0)
+    if(NULL == (opened_obj = H5VL_object_open(vol_obj, &loc_params, &opened_type, H5P_DATASET_XFER_DEFAULT, 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(opened_type, opened_obj, vol_obj->connector, TRUE)) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTREGISTER, H5I_INVALID_HID, "unable to atomize object handle")
+
 done:
     FUNC_LEAVE_API(ret_value)
 } /* end H5Oopen() */
@@ -154,15 +171,16 @@ hid_t
 H5Oopen_by_idx(hid_t loc_id, const char *group_name, H5_index_t idx_type,
     H5_iter_order_t order, hsize_t n, hid_t lapl_id)
 {
-    H5G_loc_t	loc;                    /* Location of group */
+    H5VL_object_t *vol_obj;             /* Object token of loc_id */
+    H5I_type_t opened_type;
+    void *opened_obj = NULL;
+    H5VL_loc_params_t loc_params;
     hid_t ret_value = H5I_INVALID_HID;
 
     FUNC_ENTER_API(H5I_INVALID_HID)
     H5TRACE6("i", "i*sIiIohi", loc_id, group_name, idx_type, order, n, lapl_id);
 
     /* Check args */
-    if(H5G_loc(loc_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a location")
     if(!group_name || !*group_name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "no name specified")
     if(idx_type <= H5_INDEX_UNKNOWN || idx_type >= H5_INDEX_N)
@@ -174,10 +192,25 @@ H5Oopen_by_idx(hid_t loc_id, const char *group_name, H5_index_t idx_type,
     if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, FALSE) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, H5I_INVALID_HID, "can't set access property list info")
 
+    loc_params.type = H5VL_OBJECT_BY_IDX;
+    loc_params.loc_data.loc_by_idx.name = group_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.lapl_id = lapl_id;
+    loc_params.obj_type = H5I_get_type(loc_id);
+
+    /* get the location object */
+    if(NULL == (vol_obj = (H5VL_object_t *)H5I_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid location identifier")
+
     /* Open the object */
-    if((ret_value = H5O_open_by_idx(&loc, group_name, idx_type, order, n)) < 0)
+    if(NULL == (opened_obj = H5VL_object_open(vol_obj, &loc_params, &opened_type, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL)))
         HGOTO_ERROR(H5E_OHDR, H5E_CANTOPENOBJ, H5I_INVALID_HID, "unable to open object")
 
+    if((ret_value = H5VL_register(opened_type, opened_obj, vol_obj->connector, TRUE)) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTREGISTER, H5I_INVALID_HID, "unable to atomize object handle")
+
 done:
     FUNC_LEAVE_API(ret_value)
 } /* end H5Oopen_by_idx() */
@@ -221,23 +254,60 @@ done:
 hid_t
 H5Oopen_by_addr(hid_t loc_id, haddr_t addr)
 {
-    H5G_loc_t	loc;                    /* Location within file */
-    hid_t       ret_value = H5I_INVALID_HID;	/* Return value */
+    H5VL_object_t *vol_obj;             /* Object token of loc_id */
+    H5I_type_t vol_obj_type = H5I_BADID;/* Object type of loc_id */
+    H5I_type_t opened_type;             /* Opened object type */
+    void *opened_obj = NULL;            /* Opened object */
+    H5VL_loc_params_t loc_params;       /* Location parameters */
+    H5VL_token_t obj_token = {0};       /* Object token */
+    hid_t file_id = H5I_INVALID_HID;    /* File ID */
+    void *vol_obj_file = NULL;          /* Object token of file_id */
+    H5F_t *f = NULL;
+    uint8_t *p = NULL;
+    hid_t ret_value = H5I_INVALID_HID;  /* Return value */
 
     FUNC_ENTER_API(H5I_INVALID_HID)
     H5TRACE2("i", "ia", loc_id, addr);
 
-    /* Check args */
-    if(H5G_loc(loc_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a location")
-    if(!H5F_addr_defined(addr))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, H5I_INVALID_HID, "no address supplied")
+    /* Get the location object */
+    if(NULL == (vol_obj = (H5VL_object_t *)H5I_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid location identifier")
+
+    /* Get object type */
+    if((vol_obj_type = H5I_get_type(loc_id)) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid location identifier")
+
+    /* Get the file for the object */
+    if((file_id = H5F_get_file_id(loc_id, vol_obj_type, FALSE)) < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "not a file or file object")
+
+    /* Retrieve VOL object */
+    if(NULL == (vol_obj_file = H5VL_vol_object(file_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid location identifier")
+
+    /* Retrieve file from VOL object */
+    if(NULL == (f = (H5F_t *)H5VL_object_data(vol_obj_file)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, H5I_INVALID_HID, "invalid VOL object")
+
+    /* This is a native specific routine that requires serialization of the token */
+    p = obj_token;
+    H5F_addr_encode(f, &p, addr);
+
+    loc_params.type = H5VL_OBJECT_BY_TOKEN;
+    loc_params.loc_data.loc_by_token.token = obj_token;
+    loc_params.obj_type = vol_obj_type;
 
     /* Open the object */
-    if((ret_value = H5O_open_by_addr(&loc, addr)) < 0)
+    if(NULL == (opened_obj = H5VL_object_open(vol_obj, &loc_params, &opened_type, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL)))
         HGOTO_ERROR(H5E_OHDR, H5E_CANTOPENOBJ, H5I_INVALID_HID, "unable to open object")
 
+    /* Register the dataset ID */
+    if((ret_value = H5VL_register(opened_type, opened_obj, vol_obj->connector, TRUE)) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTREGISTER, H5I_INVALID_HID, "unable to atomize object handle")
+
 done:
+    if(file_id != H5I_INVALID_HID && H5I_dec_ref(file_id) < 0)
+        HDONE_ERROR(H5E_REFERENCE, H5E_CANTDEC, H5I_INVALID_HID, "unable to decrement refcount on file")
     FUNC_LEAVE_API(ret_value)
 } /* end H5Oopen_by_addr() */
 
@@ -267,20 +337,19 @@ herr_t
 H5Olink(hid_t obj_id, hid_t new_loc_id, const char *new_name, hid_t lcpl_id,
     hid_t lapl_id)
 {
-    H5G_loc_t	new_loc;		/* Location of group to link from */
-    H5G_loc_t	obj_loc;		/* Location of object to link to */
-    herr_t      ret_value = SUCCEED;       /* Return value */
+    H5VL_object_t    *vol_obj1 = NULL;        /* object token of obj_id */
+    H5VL_object_t    *vol_obj2 = NULL;        /* object token of new_loc_id */
+    H5VL_object_t     tmp_vol_obj;            /* Temporary object token of */
+    H5VL_loc_params_t loc_params1;
+    H5VL_loc_params_t loc_params2;
+    herr_t         ret_value = SUCCEED;       /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE5("e", "ii*sii", obj_id, new_loc_id, new_name, lcpl_id, lapl_id);
 
     /* Check arguments */
-    if(H5G_loc(obj_id, &obj_loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
     if(new_loc_id == H5L_SAME_LOC)
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "cannot use H5L_SAME_LOC when only one location is specified")
-    if(H5G_loc(new_loc_id, &new_loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
     if(!new_name || !*new_name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name specified")
 /* Avoid compiler warning on 32-bit machines */
@@ -291,12 +360,42 @@ H5Olink(hid_t obj_id, hid_t new_loc_id, const char *new_name, hid_t lcpl_id,
     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 group access property list */
+    if(H5P_DEFAULT == lcpl_id)
+        lcpl_id = H5P_LINK_CREATE_DEFAULT;
+
     /* Verify access property list and set up collective metadata if appropriate */
     if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, obj_id, TRUE) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set access property list info")
 
-    /* Link to the object */
-    if(H5L_link(&new_loc, new_name, &obj_loc, lcpl_id) < 0)
+    loc_params1.type = H5VL_OBJECT_BY_SELF;
+    loc_params1.obj_type = H5I_get_type(obj_id);
+
+    loc_params2.type = H5VL_OBJECT_BY_NAME;
+    loc_params2.obj_type = H5I_get_type(new_loc_id);
+    loc_params2.loc_data.loc_by_name.name = new_name;
+    loc_params2.loc_data.loc_by_name.lapl_id = lapl_id;
+
+    if(H5L_SAME_LOC != obj_id)
+        /* get the location object */
+        if(NULL == (vol_obj1 = H5VL_vol_object(obj_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+    if(H5L_SAME_LOC != new_loc_id)
+        /* get the location object */
+        if(NULL == (vol_obj2 = H5VL_vol_object(new_loc_id)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+
+    /* Make sure that the VOL connectors are the same */
+    if(vol_obj1 && vol_obj2)
+        if (vol_obj1->connector->cls->value != vol_obj2->connector->cls->value)
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "Objects are accessed through different VOL connectors and can't be linked")
+
+    /* Construct a temporary VOL object */
+    tmp_vol_obj.data = vol_obj2->data;
+    tmp_vol_obj.connector = (vol_obj1 != NULL ? vol_obj1->connector : vol_obj2->connector);
+
+    /* Create a link to the object */
+    if(H5VL_link_create(H5VL_LINK_CREATE_HARD, &tmp_vol_obj, &loc_params2, lcpl_id, lapl_id, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, vol_obj1->data, &loc_params1) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTCREATE, FAIL, "unable to create link")
 
 done:
@@ -327,22 +426,26 @@ done:
 herr_t
 H5Oincr_refcount(hid_t object_id)
 {
-    H5O_loc_t  *oloc;			/* Object location */
-    herr_t      ret_value = SUCCEED;	/* Return value */
+    H5VL_object_t *vol_obj;             /* Object token of loc_id */
+    H5VL_loc_params_t loc_params;
+    herr_t      ret_value = SUCCEED;
 
     FUNC_ENTER_API(FAIL)
     H5TRACE1("e", "i", object_id);
 
-    /* Get the object's oloc so we can adjust its link count */
-    if((oloc = H5O_get_loc(object_id)) == NULL)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "unable to get object location from ID")
+    loc_params.type = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type = H5I_get_type(object_id);
+
+    /* Get the location object */
+    if(NULL == (vol_obj = H5VL_vol_object(object_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
 
     /* Set up collective metadata if appropriate */
     if(H5CX_set_loc(object_id) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set access property list info")
 
     /* Change the object's reference count */
-    if(H5O_link(oloc, 1) < 0)
+    if(H5VL_object_specific(vol_obj, &loc_params, H5VL_OBJECT_CHANGE_REF_COUNT, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, 1) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_LINKCOUNT, FAIL, "modifying object link count failed")
 
 done:
@@ -373,22 +476,26 @@ done:
 herr_t
 H5Odecr_refcount(hid_t object_id)
 {
-    H5O_loc_t  *oloc;			/* Object location */
+    H5VL_object_t *vol_obj;             /* Object token of loc_id */
+    H5VL_loc_params_t loc_params;
     herr_t      ret_value = SUCCEED;	/* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE1("e", "i", object_id);
 
-    /* Get the object's oloc so we can adjust its link count */
-    if((oloc = H5O_get_loc(object_id)) == NULL)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "unable to get object location from ID")
+    loc_params.type = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type = H5I_get_type(object_id);
+
+    /* Get the location object */
+    if(NULL == (vol_obj = H5VL_vol_object(object_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
 
     /* Set up collective metadata if appropriate */
     if(H5CX_set_loc(object_id) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set access property list info")
 
     /* Change the object's reference count */
-    if(H5O_link(oloc, -1) < 0)
+    if(H5VL_object_specific(vol_obj, &loc_params, H5VL_OBJECT_CHANGE_REF_COUNT, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, -1) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_LINKCOUNT, FAIL, "modifying object link count failed")
 
 done:
@@ -412,15 +519,14 @@ done:
 htri_t
 H5Oexists_by_name(hid_t loc_id, const char *name, hid_t lapl_id)
 {
-    H5G_loc_t	loc;                    /* Location info */
+    H5VL_object_t *vol_obj;             /* Object token of loc_id */
+    H5VL_loc_params_t loc_params;
     htri_t      ret_value = FAIL;       /* Return value */
 
     FUNC_ENTER_API(FAIL)
     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)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "name parameter cannot be NULL")
     if(!*name)
@@ -430,8 +536,18 @@ H5Oexists_by_name(hid_t loc_id, const char *name, hid_t lapl_id)
     if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, FALSE) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set access property list info")
 
+    /* Get the location object */
+    if(NULL == (vol_obj = H5VL_vol_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "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 */
-    if((ret_value = H5G_loc_exists(&loc, name)) < 0)
+    if(H5VL_object_specific(vol_obj, &loc_params, H5VL_OBJECT_EXISTS, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &ret_value) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "unable to determine if '%s' exists", name)
 
 done:
@@ -456,22 +572,29 @@ done:
 herr_t
 H5Oget_info2(hid_t loc_id, H5O_info_t *oinfo, unsigned fields)
 {
-    H5G_loc_t   loc;                    /* Location of group */
+    H5VL_object_t *vol_obj;             /* Object token of loc_id */
+    H5VL_loc_params_t   loc_params;
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE3("e", "i*xIu", loc_id, oinfo, fields);
 
     /* 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, "oinfo parameter cannot be NULL")
     if(fields & ~H5O_INFO_ALL)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid fields")
 
+    /* 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 == (vol_obj = H5VL_vol_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+
     /* Retrieve the object's information */
-    if(H5G_loc_info(&loc, ".", oinfo, fields) < 0)
+    if(H5VL_object_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_OBJECT_GET_INFO, &loc_params, oinfo, fields) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "can't get info for object")
 
 done:
@@ -497,15 +620,14 @@ herr_t
 H5Oget_info_by_name2(hid_t loc_id, const char *name, H5O_info_t *oinfo,
     unsigned fields, hid_t lapl_id)
 {
-    H5G_loc_t	loc;                    /* Location of group */
+    H5VL_object_t *vol_obj;             /* Object token of loc_id */
+    H5VL_loc_params_t loc_params;
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE5("e", "i*s*xIui", loc_id, name, oinfo, fields, lapl_id);
 
     /* Check args */
-    if(H5G_loc(loc_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
     if(!name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "name parameter cannot be NULL")
     if(!*name)
@@ -519,8 +641,18 @@ H5Oget_info_by_name2(hid_t loc_id, const char *name, H5O_info_t *oinfo,
     if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, FALSE) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set access property list info")
 
+    /* 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 == (vol_obj = H5VL_vol_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+
     /* Retrieve the object's information */
-    if(H5G_loc_info(&loc, name, oinfo/*out*/, fields) < 0)
+    if(H5VL_object_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_OBJECT_GET_INFO, &loc_params, oinfo, fields) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "can't get info for object: '%s'", name)
 
 done:
@@ -548,7 +680,8 @@ herr_t
 H5Oget_info_by_idx2(hid_t loc_id, const char *group_name, H5_index_t idx_type,
     H5_iter_order_t order, hsize_t n, H5O_info_t *oinfo, unsigned fields, hid_t lapl_id)
 {
-    H5G_loc_t	loc;                    /* Location of group */
+    H5VL_object_t *vol_obj;             /* Object token of loc_id */
+    H5VL_loc_params_t loc_params;
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -556,8 +689,6 @@ H5Oget_info_by_idx2(hid_t loc_id, const char *group_name, H5_index_t idx_type,
              fields, lapl_id);
 
     /* Check args */
-    if(H5G_loc(loc_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
     if(!group_name || !*group_name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name specified")
     if(idx_type <= H5_INDEX_UNKNOWN || idx_type >= H5_INDEX_N)
@@ -573,8 +704,20 @@ H5Oget_info_by_idx2(hid_t loc_id, const char *group_name, H5_index_t idx_type,
     if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, FALSE) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set access property list info")
 
+    loc_params.type = H5VL_OBJECT_BY_IDX;
+    loc_params.loc_data.loc_by_idx.name = group_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.lapl_id = lapl_id;
+    loc_params.obj_type = H5I_get_type(loc_id);
+
+    /* Get the location object */
+    if(NULL == (vol_obj = H5VL_vol_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+
     /* Retrieve the object's information */
-    if(H5O__get_info_by_idx(&loc, group_name, idx_type, order, n, oinfo, fields) < 0)
+    if(H5VL_object_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_OBJECT_GET_INFO, &loc_params, oinfo, fields) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "can't get info for object")
 
 done:
@@ -602,22 +745,27 @@ done:
 herr_t
 H5Oset_comment(hid_t obj_id, const char *comment)
 {
-    H5G_loc_t	loc;                    /* Location of group */
+    H5VL_object_t *vol_obj;             /* 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*s", obj_id, comment);
 
-    /* Check args */
-    if(H5G_loc(obj_id, &loc) < 0)
+    /* Get the location object */
+    if(NULL == (vol_obj = H5VL_vol_object(obj_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
 
     /* Set up collective metadata if appropriate */
     if(H5CX_set_loc(obj_id) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set collective metadata read info")
 
+    /* Fill in location struct fields */
+    loc_params.type = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type = H5I_get_type(obj_id);
+
     /* (Re)set the object's comment */
-    if(H5G_loc_set_comment(&loc, ".", comment) < 0)
+    if(H5VL_object_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_OBJECT_SET_COMMENT, &loc_params, comment) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set comment for object")
 
 done:
@@ -646,15 +794,14 @@ herr_t
 H5Oset_comment_by_name(hid_t loc_id, const char *name, const char *comment,
     hid_t lapl_id)
 {
-    H5G_loc_t	loc;                    /* Location of group */
+    H5VL_object_t *vol_obj;             /* Object token of loc_id */
+    H5VL_loc_params_t loc_params;
     herr_t      ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE4("e", "i*s*si", loc_id, name, comment, 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")
 
@@ -662,8 +809,18 @@ H5Oset_comment_by_name(hid_t loc_id, const char *name, const char *comment,
     if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, TRUE) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set access property list info")
 
+    /* Fill in 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);
+
+    /* Get the location object */
+    if(NULL == (vol_obj = H5VL_vol_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+
     /* (Re)set the object's comment */
-    if(H5G_loc_set_comment(&loc, name, comment) < 0)
+    if(H5VL_object_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_OBJECT_SET_COMMENT, &loc_params, comment) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set comment for object: '%s'", name)
 
 done:
@@ -690,18 +847,23 @@ done:
 ssize_t
 H5Oget_comment(hid_t obj_id, char *comment, size_t bufsize)
 {
-    H5G_loc_t	loc;                    /* Location of group */
+    H5VL_object_t *vol_obj;             /* Object token of loc_id */
+    H5VL_loc_params_t loc_params;
     ssize_t     ret_value = -1;              /* Return value */
 
     FUNC_ENTER_API((-1))
     H5TRACE3("Zs", "i*sz", obj_id, comment, bufsize);
 
-    /* Check args */
-    if(H5G_loc(obj_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, (-1), "not a location")
+    /* Get the object */
+    if(NULL == (vol_obj = H5VL_vol_object(obj_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, (-1), "invalid location identifier")
+
+    /* Set fields in the location struct */
+    loc_params.type         = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type     = H5I_get_type(obj_id);
 
     /* Retrieve the object's comment */
-    if((ret_value = H5G_loc_get_comment(&loc, ".", comment/*out*/, bufsize)) < 0)
+    if(H5VL_object_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_OBJECT_GET_COMMENT, &loc_params, comment, bufsize, &ret_value) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, (-1), "can't get comment for object")
 
 done:
@@ -729,15 +891,14 @@ ssize_t
 H5Oget_comment_by_name(hid_t loc_id, const char *name, char *comment, size_t bufsize,
     hid_t lapl_id)
 {
-    H5G_loc_t	loc;                    /* Location of group */
+    H5VL_object_t *vol_obj;             /* Object token of loc_id */
+    H5VL_loc_params_t loc_params;
     ssize_t     ret_value = -1;              /* Return value */
 
     FUNC_ENTER_API((-1))
     H5TRACE5("Zs", "i*s*szi", loc_id, name, comment, bufsize, lapl_id);
 
     /* Check args */
-    if(H5G_loc(loc_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, (-1), "not a location")
     if(!name || !*name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, (-1), "no name")
 
@@ -745,8 +906,18 @@ H5Oget_comment_by_name(hid_t loc_id, const char *name, char *comment, size_t buf
     if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, FALSE) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, (-1), "can't set access property list info")
 
+    /* Fill in 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);
+
+    /* Get the location object */
+    if(NULL == (vol_obj = H5VL_vol_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, (-1), "invalid location identifier")
+
     /* Retrieve the object's comment */
-    if((ret_value = H5G_loc_get_comment(&loc, name, comment/*out*/, bufsize)) < 0)
+    if(H5VL_object_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_OBJECT_GET_COMMENT, &loc_params, comment, bufsize, &ret_value) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, (-1), "can't get comment for object: '%s'", name)
 
 done:
@@ -793,15 +964,14 @@ herr_t
 H5Ovisit2(hid_t obj_id, H5_index_t idx_type, H5_iter_order_t order,
     H5O_iterate_t op, void *op_data, unsigned fields)
 {
-    H5G_loc_t           loc;
+    H5VL_object_t *vol_obj;             /* Object token of loc_id */
+    H5VL_loc_params_t   loc_params;
     herr_t              ret_value;              /* Return value */
 
     FUNC_ENTER_API(FAIL)
     H5TRACE6("e", "iIiIox*xIu", obj_id, idx_type, order, op, op_data, fields);
 
     /* Check args */
-    if(H5G_loc(obj_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
     if(idx_type <= H5_INDEX_UNKNOWN || idx_type >= H5_INDEX_N)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid index type specified")
     if(order <= H5_ITER_UNKNOWN || order >= H5_ITER_N)
@@ -811,8 +981,16 @@ H5Ovisit2(hid_t obj_id, H5_index_t idx_type, H5_iter_order_t order,
     if(fields & ~H5O_INFO_ALL)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid fields")
 
+    /* Get the location object */
+    if(NULL == (vol_obj = H5VL_vol_object(obj_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+
+    /* Set location parameters */
+    loc_params.type         = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type     = H5I_get_type(obj_id);
+
     /* Visit the objects */
-    if((ret_value = H5O__visit(&loc, ".", idx_type, order, op, op_data, fields)) < 0)
+    if((ret_value = H5VL_object_specific(vol_obj, &loc_params, H5VL_OBJECT_VISIT, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, (int)idx_type, (int)order, op, op_data, fields)) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_BADITER, FAIL, "object iteration failed")
 
 done:
@@ -859,7 +1037,8 @@ herr_t
 H5Ovisit_by_name2(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
     H5_iter_order_t order, H5O_iterate_t op, void *op_data, unsigned fields, hid_t lapl_id)
 {
-    H5G_loc_t           loc;
+    H5VL_object_t *vol_obj;             /* Object token of loc_id */
+    H5VL_loc_params_t   loc_params; 
     herr_t              ret_value;              /* Return value */
 
     FUNC_ENTER_API(FAIL)
@@ -867,8 +1046,6 @@ H5Ovisit_by_name2(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
              fields, lapl_id);
 
     /* Check args */
-    if(H5G_loc(loc_id, &loc) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
     if(!obj_name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "obj_name parameter cannot be NULL")
     if(!*obj_name)
@@ -886,8 +1063,18 @@ H5Ovisit_by_name2(hid_t loc_id, const char *obj_name, H5_index_t idx_type,
     if(H5CX_set_apl(&lapl_id, H5P_CLS_LACC, loc_id, FALSE) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_CANTSET, FAIL, "can't set access property list info")
 
+    /* Get the location object */
+    if(NULL == (vol_obj = H5VL_vol_object(loc_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid location identifier")
+
+    /* Set location parameters */
+    loc_params.type                         = H5VL_OBJECT_BY_NAME;
+    loc_params.loc_data.loc_by_name.name    = obj_name;
+    loc_params.loc_data.loc_by_name.lapl_id = lapl_id;
+    loc_params.obj_type                     = H5I_get_type(loc_id);
+
     /* Visit the objects */
-    if((ret_value = H5O__visit(&loc, obj_name, idx_type, order, op, op_data, fields)) < 0)
+    if((ret_value = H5VL_object_specific(vol_obj, &loc_params, H5VL_OBJECT_VISIT, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, (int)idx_type, (int)order, op, op_data, fields)) < 0)
         HGOTO_ERROR(H5E_OHDR, H5E_BADITER, FAIL, "object iteration failed")
 
 done:
@@ -925,6 +1112,7 @@ H5Oclose(hid_t object_id)
         case H5I_GROUP:
         case H5I_DATATYPE:
         case H5I_DATASET:
+        case H5I_MAP:
             if(H5I_object(object_id) == NULL)
                 HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "not a valid object")
             if(H5I_dec_app_ref(object_id) < 0)
@@ -936,13 +1124,14 @@ H5Oclose(hid_t object_id)
         case H5I_FILE:
         case H5I_DATASPACE:
         case H5I_ATTR:
-        case H5I_REFERENCE:
         case H5I_VFL:
+        case H5I_VOL:
         case H5I_GENPROP_CLS:
         case H5I_GENPROP_LST:
         case H5I_ERROR_CLASS:
         case H5I_ERROR_MSG:
         case H5I_ERROR_STACK:
+        case H5I_SPACE_SEL_ITER:
         case H5I_NTYPES:
         default:
             HGOTO_ERROR(H5E_ARGS, H5E_CANTRELEASE, FAIL, "not a valid file object ID (dataset, group, or datatype)")
@@ -955,113 +1144,215 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Odisable_mdc_flushes
+ * Function:    H5O_disable_mdc_flushes
  *
- * Purpose:	To "cork" an object:
- *		--keep dirty entries associated with the object in the metadata cache
+ * Purpose:     Private version of the metadata cache cork function.
  *
- * Return:	Success:	Non-negative
- *		Failure:	Negative
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5O_disable_mdc_flushes(H5O_loc_t *oloc)
+{
+    herr_t      ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI(FAIL);
+
+    if (H5AC_cork(oloc->file, oloc->addr, H5AC__SET_CORK, NULL) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTCORK, FAIL, "unable to cork object");
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value);
+} /* H5O_disable_mdc_flushes() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5Odisable_mdc_flushes
+ *
+ * Purpose:     "Cork" an object, keeping dirty entries associated with the
+ *              object in the metadata cache.
  *
- * Programmer:	Vailin Choi
- *		January 2014
+ * Return:      Success:    Non-negative
+ *              Failure:    Negative
+ *
+ * Programmer:  Vailin Choi
+ *              January 2014
  *
  *-------------------------------------------------------------------------
  */
 herr_t
 H5Odisable_mdc_flushes(hid_t object_id)
 {
-    H5O_loc_t  *oloc;			/* Object location */
-    herr_t      ret_value = SUCCEED;	/* Return value */
+    H5VL_object_t       *vol_obj;               /* Object token of loc_id */
+    H5VL_loc_params_t   loc_params;             /* Location parameters */
+    herr_t              ret_value = SUCCEED;    /* Return value */
 
-    FUNC_ENTER_API(FAIL)
+    FUNC_ENTER_API(FAIL);
     H5TRACE1("e", "i", object_id);
 
-    /* Get the object's oloc */
-    if(NULL == (oloc = H5O_get_loc(object_id)))
-        HGOTO_ERROR(H5E_OHDR, H5E_BADVALUE, FAIL, "unable to get object location from ID")
+    /* Make sure the ID is a file object */
+    if (H5I_is_file_object(object_id) != TRUE)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID is not a file object");
+
+    /* Get the VOL object */
+    if (NULL == (vol_obj = H5VL_vol_object(object_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid object ID");
 
-    if(H5AC_cork(oloc->file, oloc->addr, H5AC__SET_CORK, NULL) < 0)
-        HGOTO_ERROR(H5E_OHDR, H5E_CANTCORK, FAIL, "unable to cork an object")
+    /* Fill in location struct fields */
+    loc_params.type = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type = H5I_get_type(object_id);
+
+    /* Cork the object */
+    if(H5VL_object_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_OBJECT_DISABLE_MDC_FLUSHES, &loc_params) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTCORK, FAIL, "unable to cork object");
 
 done:
-    FUNC_LEAVE_API(ret_value)
+    FUNC_LEAVE_API(ret_value);
 } /* H5Odisable_mdc_flushes() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Oenable_mdc_flushes
+ * Function:    H5O_enable_mdc_flushes
  *
- * Purpose:	To "uncork" an object
- *		--release keeping dirty entries associated with the object 
- *		  in the metadata cache
+ * Purpose:     Private version of the metadata cache uncork function.
  *
- * Return:	Success:	Non-negative
- *		Failure:	Negative
+ * Return:      SUCCEED/FAIL
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5O_enable_mdc_flushes(H5O_loc_t *oloc)
+{
+    herr_t      ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI(FAIL);
+
+    if (H5AC_cork(oloc->file, oloc->addr, H5AC__UNCORK, NULL) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTUNCORK, FAIL, "unable to uncork object");
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value);
+} /* H5O_enable_mdc_flushes() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5Oenable_mdc_flushes
+ *
+ * Purpose:     "Uncork" an object, allowing dirty entries associated with
+ *              the object to be flushed.
+ *
+ * Return:      Success:    Non-negative
+ *              Failure:    Negative
  *
- * Programmer:	Vailin Choi
- *		January 2014
+ * Programmer:  Vailin Choi
+ *              January 2014
  *
  *-------------------------------------------------------------------------
  */
 herr_t
 H5Oenable_mdc_flushes(hid_t object_id)
 {
-    H5O_loc_t  *oloc;			/* Object location */
-    herr_t      ret_value = SUCCEED;	/* Return value */
+    H5VL_object_t       *vol_obj;               /* Object token of loc_id */
+    H5VL_loc_params_t   loc_params;             /* Location parameters */
+    herr_t              ret_value = SUCCEED;    /* Return value */
 
-    FUNC_ENTER_API(FAIL)
+    FUNC_ENTER_API(FAIL);
     H5TRACE1("e", "i", object_id);
 
-    /* Get the object's oloc */
-    if(NULL == (oloc = H5O_get_loc(object_id)))
-        HGOTO_ERROR(H5E_OHDR, H5E_BADVALUE, FAIL, "unable to get object location from ID")
+    /* Make sure the ID is a file object */
+    if (H5I_is_file_object(object_id) != TRUE)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID is not a file object");
+
+    /* Get the VOL object */
+    if (NULL == (vol_obj = H5VL_vol_object(object_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid object ID");
+
+    /* Fill in location struct fields */
+    loc_params.type = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type = H5I_get_type(object_id);
 
-    /* Set the value */
-    if(H5AC_cork(oloc->file, oloc->addr, H5AC__UNCORK, NULL) < 0)
-        HGOTO_ERROR(H5E_OHDR, H5E_CANTUNCORK, FAIL, "unable to uncork an object")
+    /* Uncork the object */
+    if (H5VL_object_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_OBJECT_ENABLE_MDC_FLUSHES, &loc_params) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTUNCORK, FAIL, "unable to uncork object");
 
 done:
-    FUNC_LEAVE_API(ret_value)
+    FUNC_LEAVE_API(ret_value);
 } /* H5Oenable_mdc_flushes() */
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5Oare_mdc_flushes_disabled
+ * Function:    H5O_are_mdc_flushes_disabled
  *
- * Purpose:	Retrieve the object's "cork" status in the parameter "are_disabled":
- *		  TRUE if mdc flushes for the object is disabled
- *		  FALSE if mdc flushes for the object is not disabled
- *		Return error if the parameter "are_disabled" is not supplied
+ * Purpose:     Private version of cork status getter.
  *
- * Return:	Success:	Non-negative
- *		Failure:	Negative
+ * Return:      SUCCEED/FAIL
  *
- * Programmer:	Vailin Choi
- *		January 2014
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5O_are_mdc_flushes_disabled(H5O_loc_t *oloc, hbool_t *are_disabled)
+{
+    herr_t      ret_value = SUCCEED;
+
+    FUNC_ENTER_NOAPI(FAIL);
+
+    HDassert(are_disabled);
+
+    if (H5AC_cork(oloc->file, oloc->addr, H5AC__GET_CORKED, are_disabled) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "unable to retrieve object's cork status");
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5O_are_mdc_flushes_disabled() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5Oare_mdc_flushes_disabled
+ *
+ * Purpose:     Retrieve the object's "cork" status in the parameter "are_disabled":
+ *                  TRUE if mdc flushes for the object is disabled
+ *                  FALSE if mdc flushes for the object is not disabled
+ *
+ *              Return error if the parameter "are_disabled" is not supplied
+ *
+ * Return:      Success:    Non-negative
+ *              Failure:    Negative
+ *
+ * Programmer:  Vailin Choi
+ *              January 2014
  *
  *-------------------------------------------------------------------------
  */
 herr_t
 H5Oare_mdc_flushes_disabled(hid_t object_id, hbool_t *are_disabled)
 {
-    H5O_loc_t  *oloc;			/* Object location */
-    herr_t      ret_value = SUCCEED;	/* Return value */
+    H5VL_object_t       *vol_obj;               /* Object token of loc_id */
+    H5VL_loc_params_t   loc_params;             /* Location parameters */
+    herr_t              ret_value = SUCCEED;    /* Return value */
 
-    FUNC_ENTER_API(FAIL)
+    FUNC_ENTER_API(FAIL);
     H5TRACE2("e", "i*b", object_id, are_disabled);
 
-    /* Check args */
+    /* Sanity check */
+    if (!are_disabled)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "unable to get object location from ID");
+
+    /* Make sure the ID is a file object */
+    if (H5I_is_file_object(object_id) != TRUE)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "ID is not a file object");
+
+    /* Get the VOL object */
+    if (NULL == (vol_obj = H5VL_vol_object(object_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid object ID");
 
-    /* Get the object's oloc */
-    if(NULL == (oloc = H5O_get_loc(object_id)))
-        HGOTO_ERROR(H5E_OHDR, H5E_BADVALUE, FAIL, "unable to get object location from ID")
-    if(!are_disabled)
-        HGOTO_ERROR(H5E_OHDR, H5E_BADVALUE, FAIL, "unable to get object location from ID")
+    /* Fill in location struct fields */
+    loc_params.type = H5VL_OBJECT_BY_SELF;
+    loc_params.obj_type = H5I_get_type(object_id);
 
     /* Get the cork status */
-    if(H5AC_cork(oloc->file, oloc->addr, H5AC__GET_CORKED, are_disabled) < 0)
-        HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "unable to retrieve an object's cork status")
+    if (H5VL_object_optional(vol_obj, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, H5VL_NATIVE_OBJECT_ARE_MDC_FLUSHES_DISABLED, &loc_params, are_disabled) < 0)
+        HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, FAIL, "unable to retrieve object's cork status");
 
 done:
     FUNC_LEAVE_API(ret_value)