Merge branch 'hdf5_1_12' of https://bitbucket.hdfgroup.org/scm/hdffv/hdf5 into hdf5_1_12

21 files changed, 326 insertions, 250 deletions

diff --git a/src/H5Fprivate.h b/src/H5Fprivate.h
index c9a1b25..e1a8a2f 100644
--- a/src/H5Fprivate.h
+++ b/src/H5Fprivate.h
@@ -26,7 +26,6 @@ typedef struct H5F_t H5F_t;
 
 /* Public headers needed by this file */
 #include "H5FDpublic.h"         /* File drivers                */
-#include "H5VLpublic.h"         /* Virtual Object Layer        */
 
 /* Private headers needed by this file */
 #include "H5MMprivate.h"	/* Memory management	       */
@@ -34,6 +33,7 @@ typedef struct H5F_t H5F_t;
 #include "H5Pprivate.h"         /* Property lists              */
 #endif /* H5_HAVE_PARALLEL */
 #include "H5VMprivate.h"        /* Vectors and arrays          */
+#include "H5VLprivate.h"        /* Virtual Object Layer        */
 
 
 /**************************/
@@ -337,6 +337,7 @@ typedef struct H5F_t H5F_t;
 #define H5F_GET_MIN_DSET_OHDR(F) ((F)->shared->crt_dset_min_ohdr_flag)
 #define H5F_SET_MIN_DSET_OHDR(F, V) ((F)->shared->crt_dset_min_ohdr_flag = (V))
 #define H5F_VOL_CLS(F)          ((F)->shared->vol_cls)
+#define H5F_VOL_OBJ(F)          ((F)->vol_obj)
 #else /* H5F_MODULE */
 #define H5F_LOW_BOUND(F)        (H5F_get_low_bound(F))
 #define H5F_HIGH_BOUND(F)       (H5F_get_high_bound(F))
@@ -398,6 +399,7 @@ typedef struct H5F_t H5F_t;
 #define H5F_GET_MIN_DSET_OHDR(F) (H5F_get_min_dset_ohdr(F))
 #define H5F_SET_MIN_DSET_OHDR(F, V) (H5F_set_min_dset_ohdr((F), (V)))
 #define H5F_VOL_CLS(F)          (H5F_get_vol_cls(F))
+#define H5F_VOL_OBJ(F)          (H5F_get_vol_obj(F))
 #endif /* H5F_MODULE */
 
 
@@ -759,6 +761,7 @@ H5_DLL hbool_t H5F_get_null_fsm_addr(const H5F_t *f);
 H5_DLL hbool_t H5F_get_min_dset_ohdr(const H5F_t *f);
 H5_DLL herr_t H5F_set_min_dset_ohdr(H5F_t *f, hbool_t minimize);
 H5_DLL const H5VL_class_t *H5F_get_vol_cls(const H5F_t *f);
+H5_DLL H5VL_object_t *H5F_get_vol_obj(const H5F_t *f);
 
 /* Functions than retrieve values set/cached from the superblock/FCPL */
 H5_DLL haddr_t H5F_get_base_addr(const H5F_t *f);
diff --git a/src/H5Fquery.c b/src/H5Fquery.c
index 32743c4..68ad8e5 100644
--- a/src/H5Fquery.c
+++ b/src/H5Fquery.c
@@ -1306,6 +1306,26 @@ H5F_get_vol_cls(const H5F_t *f)
 
 
 /*-------------------------------------------------------------------------
+ * Function: H5F_get_vol_obj
+ *
+ * Purpose:  Get the VOL object for the file
+ *
+ * Return:   VOL object pointer for file, can't fail
+ *
+ *-------------------------------------------------------------------------
+ */
+H5VL_object_t *
+H5F_get_vol_obj(const H5F_t *f)
+{
+    FUNC_ENTER_NOAPI_NOINIT_NOERR
+
+    HDassert(f);
+
+    FUNC_LEAVE_NOAPI(f->vol_obj)
+} /* end H5F_get_vol_obj */
+
+
+/*-------------------------------------------------------------------------
  * Function:    H5F_get_cont_info
  *
  * Purpose:     Get the VOL container info for the file
diff --git a/src/H5Ocopy_ref.c b/src/H5Ocopy_ref.c
index 3b18073..d8efeb5 100644
--- a/src/H5Ocopy_ref.c
+++ b/src/H5Ocopy_ref.c
@@ -333,7 +333,7 @@ H5O__copy_expand_ref_object2(H5O_loc_t *src_oloc, hid_t tid_src, H5T_t *dt_src,
     /* create reference datatype at the destinaton file */
     if(NULL == (dt_dst = H5T_copy(dt_src, H5T_COPY_TRANSIENT)))
         HGOTO_ERROR(H5E_OHDR, H5E_CANTINIT, FAIL, "unable to copy")
-    if(H5T_set_loc(dt_dst, dst_oloc->file, H5T_LOC_DISK) < 0) {
+    if(H5T_set_loc(dt_dst, H5F_VOL_OBJ(dst_oloc->file), H5T_LOC_DISK) < 0) {
         (void)H5T_close_real(dt_dst);
         HGOTO_ERROR(H5E_OHDR, H5E_CANTINIT, FAIL, "cannot mark datatype on disk")
     } /* end if */
diff --git a/src/H5R.c b/src/H5R.c
index 11b75ca..162bd8c 100644
--- a/src/H5R.c
+++ b/src/H5R.c
@@ -74,7 +74,7 @@
  *-------------------------------------------------------------------------
  */
 herr_t
-H5Rcreate_object(hid_t loc_id, const char *name, H5R_ref_t *ref_ptr)
+H5Rcreate_object(hid_t loc_id, const char *name, hid_t oapl_id, H5R_ref_t *ref_ptr)
 {
     H5VL_object_t *vol_obj = NULL;  /* Object token of loc_id */
     H5I_type_t obj_type;            /* Object type of loc_id */
@@ -86,13 +86,22 @@ H5Rcreate_object(hid_t loc_id, const char *name, H5R_ref_t *ref_ptr)
     herr_t ret_value = SUCCEED;     /* Return value */
 
     FUNC_ENTER_API(FAIL)
-    H5TRACE3("e", "i*s*Rr", loc_id, name, ref_ptr);
+    H5TRACE4("e", "i*si*Rr", loc_id, name, oapl_id, ref_ptr);
 
     /* Check args */
     if(ref_ptr == NULL)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "invalid reference pointer")
     if(!name || !*name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name given")
+    if(oapl_id < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a property list")
+
+    /* Get object access property list */
+    if(H5P_DEFAULT == oapl_id)
+        oapl_id = H5P_LINK_ACCESS_DEFAULT;
+    else
+        if(TRUE != H5P_isa_class(oapl_id, H5P_LINK_ACCESS))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "oapl_id is not a link access property list ID")
 
     /* Get the VOL object */
     if(NULL == (vol_obj = H5VL_vol_object(loc_id)))
@@ -117,6 +126,7 @@ H5Rcreate_object(hid_t loc_id, const char *name, H5R_ref_t *ref_ptr)
     /* Set location parameters */
     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 = oapl_id;
     loc_params.obj_type = obj_type;
 
     /* Get the object token */
@@ -152,7 +162,7 @@ done:
  */
 herr_t
 H5Rcreate_region(hid_t loc_id, const char *name, hid_t space_id,
-    H5R_ref_t *ref_ptr)
+    hid_t oapl_id, H5R_ref_t *ref_ptr)
 {
     H5VL_object_t *vol_obj = NULL;  /* Object token of loc_id */
     H5I_type_t obj_type;            /* Object type of loc_id */
@@ -165,7 +175,7 @@ H5Rcreate_region(hid_t loc_id, const char *name, hid_t space_id,
     herr_t ret_value = SUCCEED;     /* Return value */
 
     FUNC_ENTER_API(FAIL)
-    H5TRACE4("e", "i*si*Rr", loc_id, name, space_id, ref_ptr);
+    H5TRACE5("e", "i*sii*Rr", loc_id, name, space_id, oapl_id, ref_ptr);
 
     /* Check args */
     if(ref_ptr == NULL)
@@ -176,6 +186,15 @@ H5Rcreate_region(hid_t loc_id, const char *name, hid_t space_id,
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "reference region dataspace id must be valid")
     if(NULL == (space = (struct H5S_t *)H5I_object_verify(space_id, H5I_DATASPACE)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a dataspace")
+    if(oapl_id < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a property list")
+
+    /* Get object access property list */
+    if(H5P_DEFAULT == oapl_id)
+        oapl_id = H5P_LINK_ACCESS_DEFAULT;
+    else
+        if(TRUE != H5P_isa_class(oapl_id, H5P_LINK_ACCESS))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "oapl_id is not a link access property list ID")
 
     /* Get the VOL object */
     if(NULL == (vol_obj = H5VL_vol_object(loc_id)))
@@ -200,6 +219,7 @@ H5Rcreate_region(hid_t loc_id, const char *name, hid_t space_id,
     /* Set location parameters */
     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 = oapl_id;
     loc_params.obj_type = obj_type;
 
     /* Get the object token */
@@ -234,7 +254,7 @@ done:
  */
 herr_t
 H5Rcreate_attr(hid_t loc_id, const char *name, const char *attr_name,
-    H5R_ref_t *ref_ptr)
+    hid_t oapl_id, H5R_ref_t *ref_ptr)
 {
     H5VL_object_t *vol_obj = NULL;  /* Object token of loc_id */
     H5I_type_t obj_type;            /* Object type of loc_id */
@@ -246,7 +266,7 @@ H5Rcreate_attr(hid_t loc_id, const char *name, const char *attr_name,
     herr_t ret_value = SUCCEED;     /* Return value */
 
     FUNC_ENTER_API(FAIL)
-    H5TRACE4("e", "i*s*s*Rr", loc_id, name, attr_name, ref_ptr);
+    H5TRACE5("e", "i*s*si*Rr", loc_id, name, attr_name, oapl_id, ref_ptr);
 
     /* Check args */
     if(ref_ptr == NULL)
@@ -255,6 +275,15 @@ H5Rcreate_attr(hid_t loc_id, const char *name, const char *attr_name,
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name given")
     if(!attr_name || !*attr_name)
         HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no attribute name given")
+    if(oapl_id < 0)
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a property list")
+
+    /* Get object access property list */
+    if(H5P_DEFAULT == oapl_id)
+        oapl_id = H5P_LINK_ACCESS_DEFAULT;
+    else
+        if(TRUE != H5P_isa_class(oapl_id, H5P_LINK_ACCESS))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "oapl_id is not a link access property list ID")
 
     /* Get the VOL object */
     if(NULL == (vol_obj = H5VL_vol_object(loc_id)))
@@ -279,6 +308,7 @@ H5Rcreate_attr(hid_t loc_id, const char *name, const char *attr_name,
     /* Set location parameters */
     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 = oapl_id;
     loc_params.obj_type = obj_type;
 
     /* Get the object token */
diff --git a/src/H5Rdeprec.c b/src/H5Rdeprec.c
index b9bdffa..f0dc503 100644
--- a/src/H5Rdeprec.c
+++ b/src/H5Rdeprec.c
@@ -258,6 +258,7 @@ H5Rcreate(void *ref, hid_t loc_id, const char *name, H5R_type_t ref_type,
     /* Set location parameters */
     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 = H5P_LINK_ACCESS_DEFAULT;
     loc_params.obj_type = vol_obj_type;
 
     /* Get the object token */
diff --git a/src/H5Rpublic.h b/src/H5Rpublic.h
index 1f0887a..3577ef9 100644
--- a/src/H5Rpublic.h
+++ b/src/H5Rpublic.h
@@ -104,9 +104,9 @@ extern "C" {
 #endif
 
 /* Constructors */
-H5_DLL herr_t   H5Rcreate_object(hid_t loc_id, const char *name, H5R_ref_t *ref_ptr);
-H5_DLL herr_t   H5Rcreate_region(hid_t loc_id, const char *name, hid_t space_id, H5R_ref_t *ref_ptr);
-H5_DLL herr_t   H5Rcreate_attr(hid_t loc_id, const char *name, const char *attr_name, H5R_ref_t *ref_ptr);
+H5_DLL herr_t   H5Rcreate_object(hid_t loc_id, const char *name, hid_t oapl_id, H5R_ref_t *ref_ptr);
+H5_DLL herr_t   H5Rcreate_region(hid_t loc_id, const char *name, hid_t space_id, hid_t oapl_id, H5R_ref_t *ref_ptr);
+H5_DLL herr_t   H5Rcreate_attr(hid_t loc_id, const char *name, const char *attr_name, hid_t oapl_id, H5R_ref_t *ref_ptr);
 H5_DLL herr_t   H5Rdestroy(H5R_ref_t *ref_ptr);
 
 /* Info */
diff --git a/src/H5Shyper.c b/src/H5Shyper.c
index 2c7502a..c6314de 100644
--- a/src/H5Shyper.c
+++ b/src/H5Shyper.c
@@ -4263,6 +4263,9 @@ H5S__hyper_deserialize(H5S_t **space, const uint8_t **p)
     /* Decode version */
     UINT32DECODE(pp, version);
 
+    if(version < H5S_HYPER_VERSION_1 || version > H5S_HYPER_VERSION_LATEST)
+        HGOTO_ERROR(H5E_DATASPACE, H5E_BADVALUE, FAIL, "bad version number for hyperslab selection")
+
     if(version >= (uint32_t)H5S_HYPER_VERSION_2) {
         /* Decode flags */
         flags = *(pp)++;
diff --git a/src/H5Smpio.c b/src/H5Smpio.c
index 46c43da..800913f 100644
--- a/src/H5Smpio.c
+++ b/src/H5Smpio.c
@@ -86,7 +86,7 @@ static herr_t H5S__mpio_span_hyper_type(const H5S_t *space, size_t elmt_size,
 static herr_t H5S__release_datatype(H5S_mpio_mpitype_list_t *type_list);
 static herr_t H5S__obtain_datatype(H5S_hyper_span_info_t *spans, const hsize_t *down,
     size_t elmt_size, const MPI_Datatype *elmt_type, MPI_Datatype *span_type,
-    H5S_mpio_mpitype_list_t *type_list, uint64_t op_gen);
+    H5S_mpio_mpitype_list_t *type_list, unsigned op_info_i, uint64_t op_gen);
 
 
 /*****************************/
diff --git a/src/H5Spkg.h b/src/H5Spkg.h
index 6809643..2f15a74 100644
--- a/src/H5Spkg.h
+++ b/src/H5Spkg.h
@@ -41,9 +41,10 @@
 #define H5S_SELECT_FLAG_BITS    (H5S_HYPER_REGULAR)
 
 /* Versions for H5S_SEL_HYPER selection info */
-#define H5S_HYPER_VERSION_1     1
-#define H5S_HYPER_VERSION_2     2
-#define H5S_HYPER_VERSION_3     3
+#define H5S_HYPER_VERSION_1         1
+#define H5S_HYPER_VERSION_2         2
+#define H5S_HYPER_VERSION_3         3
+#define H5S_HYPER_VERSION_LATEST    H5S_HYPER_VERSION_3
 
 /* Versions for H5S_SEL_POINTS selection info */
 #define H5S_POINT_VERSION_1     1
diff --git a/src/H5T.c b/src/H5T.c
index e7d6467..23c7ff6 100644
--- a/src/H5T.c
+++ b/src/H5T.c
@@ -227,7 +227,7 @@
     H5T_INIT_TYPE_ALLOC_COMMON(H5T_REFERENCE)               \
     H5T_INIT_TYPE_NUM_COMMON(H5T_ORDER_NONE)                \
     dt->shared->force_conv = TRUE;                          \
-    dt->shared->u.atomic.u.r.f = NULL;                      \
+    dt->shared->u.atomic.u.r.file = NULL;                   \
     dt->shared->u.atomic.u.r.loc = H5T_LOC_BADLOC;          \
     dt->shared->u.atomic.u.r.cls = NULL;                    \
 }
@@ -254,6 +254,7 @@
     dt->shared->u.atomic.u.r.rtype = H5R_OBJECT2;           \
     dt->shared->u.atomic.u.r.opaque = TRUE;                 \
     dt->shared->u.atomic.u.r.version = H5R_ENCODE_VERSION;  \
+    dt->shared->version = H5O_DTYPE_VERSION_4;              \
 }
 
 /* Define the code templates for the "SIZE_TMPL" in the H5T_INIT_TYPE macro */
@@ -5532,7 +5533,7 @@ H5T_set_loc(H5T_t *dt, H5VL_object_t *file, H5T_loc_t loc)
 
             case H5T_REFERENCE:
                 /* Reference types go through type conversion */
-                if((ret_value = H5T__ref_set_loc(dt, f, loc)) < 0)
+                if((ret_value = H5T__ref_set_loc(dt, file, loc)) < 0)
                     HGOTO_ERROR(H5E_DATATYPE, H5E_CANTSET, FAIL, "Unable to set reference location");
                 break;
 
diff --git a/src/H5Tconv.c b/src/H5Tconv.c
index 111ae92..6aea00e 100644
--- a/src/H5Tconv.c
+++ b/src/H5Tconv.c
@@ -3183,18 +3183,18 @@ H5T__conv_vlen(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, size_t nelmts,
                     hbool_t is_nil;      /* Whether sequence is "nil" */
 
                     /* Check for "nil" source sequence */
-                    if((*(src->shared->u.vlen.cls->isnull))(src->shared->u.vlen.f, s, &is_nil) < 0)
+                    if((*(src->shared->u.vlen.cls->isnull))(src->shared->u.vlen.file, s, &is_nil) < 0)
                         HGOTO_ERROR(H5E_DATATYPE, H5E_CANTGET, FAIL, "can't check if VL data is 'nil'")
                     else if(is_nil) {
                         /* Write "nil" sequence to destination location */
-                        if((*(dst->shared->u.vlen.cls->setnull))(dst->shared->u.vlen.f, d, b) < 0)
+                        if((*(dst->shared->u.vlen.cls->setnull))(dst->shared->u.vlen.file, d, b) < 0)
                             HGOTO_ERROR(H5E_DATATYPE, H5E_WRITEERROR, FAIL, "can't set VL data to 'nil'")
                     } /* end else-if */
                     else {
                         size_t 	seq_len;    /* The number of elements in the current sequence */
 
                         /* Get length of element sequences */
-                        if((*(src->shared->u.vlen.cls->getlen))(src->shared->u.vlen.f, s, &seq_len) < 0)
+                        if((*(src->shared->u.vlen.cls->getlen))(src->shared->u.vlen.file, s, &seq_len) < 0)
                             HGOTO_ERROR(H5E_DATATYPE, H5E_CANTGET, FAIL, "bad sequence length")
 
                         /* If we are reading from memory and there is no conversion, just get the pointer to sequence */
@@ -3226,7 +3226,7 @@ H5T__conv_vlen(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, size_t nelmts,
                             } /* end else-if */
 
                             /* Read in VL sequence */
-                            if((*(src->shared->u.vlen.cls->read))(src->shared->u.vlen.f, s, conv_buf, src_size) < 0)
+                            if((*(src->shared->u.vlen.cls->read))(src->shared->u.vlen.file, s, conv_buf, src_size) < 0)
                                 HGOTO_ERROR(H5E_DATATYPE, H5E_READERROR, FAIL, "can't read VL data")
                         } /* end else */
 
@@ -3248,7 +3248,7 @@ H5T__conv_vlen(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, size_t nelmts,
                                 HDassert(write_to_file);
 
                                 /* Get length of background element sequence */
-                                if((*(dst->shared->u.vlen.cls->getlen))(dst->shared->u.vlen.f, b, &bg_seq_len) < 0)
+                                if((*(dst->shared->u.vlen.cls->getlen))(dst->shared->u.vlen.file, b, &bg_seq_len) < 0)
                                     HGOTO_ERROR(H5E_DATATYPE, H5E_CANTGET, FAIL, "bad sequence length")
 
                                 /* Read sequence if length > 0 */
@@ -3261,7 +3261,7 @@ H5T__conv_vlen(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, size_t nelmts,
                                     } /* end if */
 
                                     /* Read in background VL sequence */
-                                    if((*(dst->shared->u.vlen.cls->read))(dst->shared->u.vlen.f, b, tmp_buf, bg_seq_len) < 0)
+                                    if((*(dst->shared->u.vlen.cls->read))(dst->shared->u.vlen.file, b, tmp_buf, bg_seq_len * dst_base_size) < 0)
                                         HGOTO_ERROR(H5E_DATATYPE, H5E_READERROR, FAIL, "can't read VL data")
                                 } /* end if */
 
@@ -3276,7 +3276,7 @@ H5T__conv_vlen(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, size_t nelmts,
                         } /* end if */
 
                         /* Write sequence to destination location */
-                        if((*(dst->shared->u.vlen.cls->write))(dst->shared->u.vlen.f, &vl_alloc_info, d, conv_buf, b, seq_len, dst_base_size) < 0)
+                        if((*(dst->shared->u.vlen.cls->write))(dst->shared->u.vlen.file, &vl_alloc_info, d, conv_buf, b, seq_len, dst_base_size) < 0)
                             HGOTO_ERROR(H5E_DATATYPE, H5E_WRITEERROR, FAIL, "can't write VL data")
 
                         if(!noop_conv) {
@@ -3291,7 +3291,7 @@ H5T__conv_vlen(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, size_t nelmts,
                                 tmp = (uint8_t *)tmp_buf + seq_len * dst_base_size;
                                 for(u = seq_len; u < bg_seq_len; u++, tmp += dst_base_size) {
                                     /* Delete sequence in destination location */
-                                    if((*(dst->shared->u.vlen.cls->del))(dst->shared->u.vlen.f, tmp) < 0)
+                                    if((*(dst->shared->u.vlen.cls->del))(dst->shared->u.vlen.file, tmp) < 0)
                                         HGOTO_ERROR(H5E_DATATYPE, H5E_CANTREMOVE, FAIL, "unable to remove heap object")
                                 } /* end for */
                             } /* end if */
@@ -3612,8 +3612,8 @@ H5T__conv_ref(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, size_t nelmts,
 
                     /* Get size of references */
                     if(0 == (buf_size = src->shared->u.atomic.u.r.cls->getsize(
-                        src->shared->u.atomic.u.r.f, s, src->shared->size,
-                        dst->shared->u.atomic.u.r.f, &dst_copy)))
+                        src->shared->u.atomic.u.r.file, s, src->shared->size,
+                        dst->shared->u.atomic.u.r.file, &dst_copy)))
                         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "incorrect size")
 
                     /* Check if conversion buffer is large enough, resize if necessary. */
@@ -3629,8 +3629,8 @@ H5T__conv_ref(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, size_t nelmts,
                     } else {
                         /* Read reference */
                         if(src->shared->u.atomic.u.r.cls->read(
-                            src->shared->u.atomic.u.r.f, s, src->shared->size,
-                            dst->shared->u.atomic.u.r.f, conv_buf, buf_size) < 0)
+                            src->shared->u.atomic.u.r.file, s, src->shared->size,
+                            dst->shared->u.atomic.u.r.file, conv_buf, buf_size) < 0)
                             HGOTO_ERROR(H5E_DATATYPE, H5E_READERROR, FAIL, "can't read reference data")
                     }
 
@@ -3639,8 +3639,8 @@ H5T__conv_ref(hid_t src_id, hid_t dst_id, H5T_cdata_t *cdata, size_t nelmts,
                     } else {
                         /* Write reference to destination location */
                         if(dst->shared->u.atomic.u.r.cls->write(
-                            src->shared->u.atomic.u.r.f, conv_buf, buf_size, src->shared->u.atomic.u.r.rtype,
-                            dst->shared->u.atomic.u.r.f, d, dst->shared->size, b) < 0)
+                            src->shared->u.atomic.u.r.file, conv_buf, buf_size, src->shared->u.atomic.u.r.rtype,
+                            dst->shared->u.atomic.u.r.file, d, dst->shared->size, b) < 0)
                             HGOTO_ERROR(H5E_DATATYPE, H5E_WRITEERROR, FAIL, "can't write reference data")
                     }
 
diff --git a/src/H5Tpkg.h b/src/H5Tpkg.h
index eec486c..1dbc229 100644
--- a/src/H5Tpkg.h
+++ b/src/H5Tpkg.h
@@ -182,9 +182,9 @@ struct H5T_path_t {
 };
 
 /* Reference function pointers */
-typedef size_t (*H5T_ref_getsizefunc_t)(H5F_t *src_f, const void *src_buf, size_t src_size, H5F_t *dst_f, hbool_t *dst_copy);
-typedef herr_t (*H5T_ref_readfunc_t)(H5F_t *src_f, const void *src_buf, size_t src_size, H5F_t *dst_f, void *dst_buf, size_t dst_size);
-typedef herr_t (*H5T_ref_writefunc_t)(H5F_t *src_f, const void *src_buf, size_t src_size, H5R_type_t src_type, H5F_t *dst_f, void *dst_buf, size_t dst_size, void *bg_buf);
+typedef size_t (*H5T_ref_getsizefunc_t)(H5VL_object_t *src_file, const void *src_buf, size_t src_size, H5VL_object_t *dst_file, hbool_t *dst_copy);
+typedef herr_t (*H5T_ref_readfunc_t)(H5VL_object_t *src_file, const void *src_buf, size_t src_size, H5VL_object_t *dst_file, void *dst_buf, size_t dst_size);
+typedef herr_t (*H5T_ref_writefunc_t)(H5VL_object_t *src_file, const void *src_buf, size_t src_size, H5R_type_t src_type, H5VL_object_t *dst_file, void *dst_buf, size_t dst_size, void *bg_buf);
 
 typedef struct H5T_ref_class_t {
     H5T_ref_getsizefunc_t   getsize;    /* get reference size (bytes)   */
@@ -224,7 +224,7 @@ typedef struct H5T_atomic_t {
             unsigned    version;    /* version of encoded reference         */
             hbool_t     opaque;     /* opaque reference type                */
             H5T_loc_t   loc;        /* location of data in buffer           */
-            H5F_t       *f;         /* file pointer (if data is on disk)    */
+            H5VL_object_t *file;    /* file VOL pointer (if data is on disk) */
             const H5T_ref_class_t *cls; /* Pointer to ref class callbacks */
         } r;    /* reference types */
     } u;
@@ -273,13 +273,13 @@ typedef enum {
 } H5T_vlen_type_t;
 
 /* VL function pointers */
-typedef herr_t (*H5T_vlen_getlen_func_t)(H5F_t *f, const void *vl_addr, size_t *len);
+typedef herr_t (*H5T_vlen_getlen_func_t)(H5VL_object_t *file, const void *vl_addr, size_t *len);
 typedef void * (*H5T_vlen_getptr_func_t)(void *vl_addr);
-typedef herr_t (*H5T_vlen_isnull_func_t)(const H5F_t *f, void *vl_addr, hbool_t *isnull);
-typedef herr_t (*H5T_vlen_setnull_func_t)(H5F_t *f, void *_vl, void *_bg);
-typedef herr_t (*H5T_vlen_read_func_t)(H5F_t *f, void *_vl, void *buf, size_t len);
-typedef herr_t (*H5T_vlen_write_func_t)(H5F_t *f, const H5T_vlen_alloc_info_t *vl_alloc_info, void *_vl, void *buf, void *_bg, size_t seq_len, size_t base_size);
-typedef herr_t (*H5T_vlen_delete_func_t)(H5F_t *f, const void *_vl);
+typedef herr_t (*H5T_vlen_isnull_func_t)(const H5VL_object_t *file, void *vl_addr, hbool_t *isnull);
+typedef herr_t (*H5T_vlen_setnull_func_t)(H5VL_object_t *file, void *_vl, void *_bg);
+typedef herr_t (*H5T_vlen_read_func_t)(H5VL_object_t *file, void *_vl, void *buf, size_t len);
+typedef herr_t (*H5T_vlen_write_func_t)(H5VL_object_t *file, const H5T_vlen_alloc_info_t *vl_alloc_info, void *_vl, void *buf, void *_bg, size_t seq_len, size_t base_size);
+typedef herr_t (*H5T_vlen_delete_func_t)(H5VL_object_t *file, const void *_vl);
 
 /* VL datatype callbacks */
 typedef struct H5T_vlen_class_t {
@@ -299,7 +299,7 @@ typedef struct H5T_vlen_t {
     H5T_cset_t          cset;   /* For VL string: character set */
     H5T_str_t           pad;    /* For VL string: space or null padding of
                                  * extra bytes */
-    H5F_t *f;                   /* File ID (if VL data is on disk) */
+    H5VL_object_t *file;            /* File object (if VL data is on disk) */
     const H5T_vlen_class_t *cls;    /* Pointer to VL class callbacks */
 } H5T_vlen_t;
 
@@ -1183,7 +1183,7 @@ H5_DLL int    H5T__get_array_ndims(const H5T_t *dt);
 H5_DLL int    H5T__get_array_dims(const H5T_t *dt, hsize_t dims[]);
 
 /* Reference functions */
-H5_DLL htri_t H5T__ref_set_loc(const H5T_t *dt, H5F_t *f, H5T_loc_t loc);
+H5_DLL htri_t H5T__ref_set_loc(const H5T_t *dt, H5VL_object_t *file, H5T_loc_t loc);
 
 /* Compound functions */
 H5_DLL herr_t H5T__insert(H5T_t *parent, const char *name, size_t offset,
diff --git a/src/H5Tref.c b/src/H5Tref.c
index 937dc92..2e52954 100644
--- a/src/H5Tref.c
+++ b/src/H5Tref.c
@@ -27,6 +27,8 @@
 #include "H5Rpkg.h"             /* References           */
 #include "H5Tpkg.h"             /* Datatypes            */
 
+#include "H5VLnative_private.h" /* Native VOL connector                     */
+
 /****************/
 /* Local Macros */
 /****************/
@@ -52,20 +54,20 @@ struct H5Tref_dsetreg {
 /* Local Prototypes */
 /********************/
 
-static size_t H5T__ref_mem_getsize(H5F_t *src_f, const void *src_buf, size_t src_size, H5F_t *dst_f, hbool_t *dst_copy);
-static herr_t H5T__ref_mem_read(H5F_t *src_f, const void *src_buf, size_t src_size, H5F_t *dst_f, void *dst_buf, size_t dst_size);
-static herr_t H5T__ref_mem_write(H5F_t *src_f, const void *src_buf, size_t src_size, H5R_type_t src_type, H5F_t *dst_f, void *dst_buf, size_t dst_size, void *bg_buf);
+static size_t H5T__ref_mem_getsize(H5VL_object_t *src_file, const void *src_buf, size_t src_size, H5VL_object_t *dst_file, hbool_t *dst_copy);
+static herr_t H5T__ref_mem_read(H5VL_object_t *src_file, const void *src_buf, size_t src_size, H5VL_object_t *dst_file, void *dst_buf, size_t dst_size);
+static herr_t H5T__ref_mem_write(H5VL_object_t *src_file, const void *src_buf, size_t src_size, H5R_type_t src_type, H5VL_object_t *dst_file, void *dst_buf, size_t dst_size, void *bg_buf);
 
-static size_t H5T__ref_disk_getsize(H5F_t *src_f, const void *src_buf, size_t src_size, H5F_t *dst_f, hbool_t *dst_copy);
-static herr_t H5T__ref_disk_read(H5F_t *src_f, const void *src_buf, size_t src_size, H5F_t *dst_f, void *dst_buf, size_t dst_size);
-static herr_t H5T__ref_disk_write(H5F_t *src_f, const void *src_buf, size_t src_size, H5R_type_t src_type, H5F_t *dst_f, void *dst_buf, size_t dst_size, void *bg_buf);
+static size_t H5T__ref_disk_getsize(H5VL_object_t *src_file, const void *src_buf, size_t src_size, H5VL_object_t *dst_file, hbool_t *dst_copy);
+static herr_t H5T__ref_disk_read(H5VL_object_t *src_file, const void *src_buf, size_t src_size, H5VL_object_t *dst_file, void *dst_buf, size_t dst_size);
+static herr_t H5T__ref_disk_write(H5VL_object_t *src_file, const void *src_buf, size_t src_size, H5R_type_t src_type, H5VL_object_t *dst_file, void *dst_buf, size_t dst_size, void *bg_buf);
 
 /* For compatibility */
-static size_t H5T__ref_obj_disk_getsize(H5F_t *src_f, const void *src_buf, size_t src_size, H5F_t *dst_f, hbool_t *dst_copy);
-static herr_t H5T__ref_obj_disk_read(H5F_t *src_f, const void *src_buf, size_t src_size, H5F_t *dst_f, void *dst_buf, size_t dst_size);
+static size_t H5T__ref_obj_disk_getsize(H5VL_object_t *src_file, const void *src_buf, size_t src_size, H5VL_object_t *dst_file, hbool_t *dst_copy);
+static herr_t H5T__ref_obj_disk_read(H5VL_object_t *src_file, const void *src_buf, size_t src_size, H5VL_object_t *dst_file, void *dst_buf, size_t dst_size);
 
-static size_t H5T__ref_dsetreg_disk_getsize(H5F_t *src_f, const void *src_buf, size_t src_size, H5F_t *dst_f, hbool_t *dst_copy);
-static herr_t H5T__ref_dsetreg_disk_read(H5F_t *src_f, const void *src_buf, size_t src_size, H5F_t *dst_f, void *dst_buf, size_t dst_size);
+static size_t H5T__ref_dsetreg_disk_getsize(H5VL_object_t *src_file, const void *src_buf, size_t src_size, H5VL_object_t *dst_file, hbool_t *dst_copy);
+static herr_t H5T__ref_dsetreg_disk_read(H5VL_object_t *src_file, const void *src_buf, size_t src_size, H5VL_object_t *dst_file, void *dst_buf, size_t dst_size);
 
 /*******************/
 /* Local Variables */
@@ -112,7 +114,7 @@ static const H5T_ref_class_t H5T_ref_dsetreg_disk_g = {
  *-------------------------------------------------------------------------
  */
 htri_t
-H5T__ref_set_loc(const H5T_t *dt, H5F_t *f, H5T_loc_t loc)
+H5T__ref_set_loc(const H5T_t *dt, H5VL_object_t *file, H5T_loc_t loc)
 {
     htri_t ret_value = FALSE; /* Indicate success, but no location change */
 
@@ -123,18 +125,18 @@ H5T__ref_set_loc(const H5T_t *dt, H5F_t *f, H5T_loc_t loc)
     HDassert(loc >= H5T_LOC_BADLOC && loc < H5T_LOC_MAXLOC);
 
     /* Only change the location if it's different */
-    if(loc == dt->shared->u.atomic.u.r.loc && f == dt->shared->u.atomic.u.r.f)
+    if(loc == dt->shared->u.atomic.u.r.loc && file == dt->shared->u.atomic.u.r.file)
         HGOTO_DONE(FALSE)
 
     switch(loc) {
         case H5T_LOC_MEMORY: /* Memory based reference datatype */
-            HDassert(NULL == f);
+            HDassert(NULL == file);
 
             /* Mark this type as being stored in memory */
             dt->shared->u.atomic.u.r.loc = H5T_LOC_MEMORY;
 
             /* Reset file ID (since this reference is in memory) */
-            dt->shared->u.atomic.u.r.f = f;     /* f is NULL */
+            dt->shared->u.atomic.u.r.file = file;     /* file is NULL */
 
             if(dt->shared->u.atomic.u.r.opaque) {
                 /* Size in memory, disk size is different */
@@ -164,15 +166,24 @@ H5T__ref_set_loc(const H5T_t *dt, H5F_t *f, H5T_loc_t loc)
             break;
 
         case H5T_LOC_DISK: /* Disk based reference datatype */
-            HDassert(f);
+            HDassert(file);
 
             /* Mark this type as being stored on disk */
             dt->shared->u.atomic.u.r.loc = H5T_LOC_DISK;
 
             /* Set file pointer (since this reference is on disk) */
-            dt->shared->u.atomic.u.r.f = f;
+            dt->shared->u.atomic.u.r.file = file;
 
             if(dt->shared->u.atomic.u.r.rtype == H5R_OBJECT1) {
+                H5F_t *f;
+
+                /* We should assert here that the terminal connector is H5VL_NATIVE once
+                 * there is a facility to do so -NAF 2019/10/30 */
+
+                /* Retrieve file from VOL object */
+                if(NULL == (f = (H5F_t *)H5VL_object_data(file)))
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid VOL object")
+
                 /* Size on disk, memory size is different */
                 dt->shared->size = H5T_REF_OBJ_DISK_SIZE(f);
                 dt->shared->u.atomic.prec = 8 * dt->shared->size;
@@ -181,6 +192,15 @@ H5T__ref_set_loc(const H5T_t *dt, H5F_t *f, H5T_loc_t loc)
                 dt->shared->u.atomic.u.r.cls = &H5T_ref_obj_disk_g;
 
             } else if(dt->shared->u.atomic.u.r.rtype == H5R_DATASET_REGION1) {
+                H5F_t *f;
+
+                /* We should assert here that the terminal connector is H5VL_NATIVE once
+                 * there is a facility to do so -NAF 2019/10/30 */
+
+                /* Retrieve file from VOL object */
+                if(NULL == (f = (H5F_t *)H5VL_object_data(file)))
+                    HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid VOL object")
+
                 /* Size on disk, memory size is different */
                 dt->shared->size = H5T_REF_DSETREG_DISK_SIZE(f);
                 dt->shared->u.atomic.prec = 8 * dt->shared->size;
@@ -194,8 +214,8 @@ H5T__ref_set_loc(const H5T_t *dt, H5F_t *f, H5T_loc_t loc)
                 H5R_ref_priv_t fixed_ref;
 
                 /* Get container info */
-                if(H5F__get_cont_info(f, &cont_info) < 0)
-                    HGOTO_ERROR(H5E_DATATYPE, H5E_CANTGET, FAIL, "can't get file container info")
+                if(H5VL_file_get(file, H5VL_FILE_GET_CONT_INFO, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &cont_info) < 0)
+                    HGOTO_ERROR(H5E_DATATYPE, H5E_CANTGET, FAIL, "unable to get container info")
 
                 /* Retrieve min encode size (when references have no vlen part) */
                 HDmemset(&fixed_ref, 0, sizeof(fixed_ref));
@@ -226,7 +246,7 @@ H5T__ref_set_loc(const H5T_t *dt, H5F_t *f, H5T_loc_t loc)
             dt->shared->u.atomic.u.r.loc = H5T_LOC_BADLOC;
 
             /* Reset file pointer */
-            dt->shared->u.atomic.u.r.f = NULL;
+            dt->shared->u.atomic.u.r.file = NULL;
 
             /* Reset the function pointers */
             dt->shared->u.atomic.u.r.cls = NULL;
@@ -257,10 +277,12 @@ done:
  *-------------------------------------------------------------------------
  */
 static size_t
-H5T__ref_mem_getsize(H5F_t H5_ATTR_UNUSED *src_f, const void *src_buf,
-    size_t H5_ATTR_UNUSED src_size, H5F_t *dst_f, hbool_t *dst_copy)
+H5T__ref_mem_getsize(H5VL_object_t H5_ATTR_UNUSED *src_file, const void *src_buf,
+    size_t H5_ATTR_UNUSED src_size, H5VL_object_t *dst_file, hbool_t *dst_copy)
 {
-    void *vol_obj = NULL;
+    H5F_t *src_f;
+    H5F_t *dst_f;
+    H5VL_object_t *vol_obj = NULL;
     const H5R_ref_priv_t *src_ref = (const H5R_ref_priv_t *)src_buf;
     unsigned flags = 0;
     size_t ret_value = 0;
@@ -274,9 +296,14 @@ H5T__ref_mem_getsize(H5F_t H5_ATTR_UNUSED *src_f, const void *src_buf,
     if(NULL == (vol_obj = H5VL_vol_object(src_ref->loc_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "invalid location identifier")
 
-    /* Retrieve file from VOL object */
+    /* We should assert here that the terminal connector is H5VL_NATIVE once
+     * there is a facility to do so -NAF 2019/10/30 */
+
+    /* Retrieve files from VOL objects */
     if(NULL == (src_f = (H5F_t *)H5VL_object_data(vol_obj)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "invalid VOL object")
+    if(NULL == (dst_f = (H5F_t *)H5VL_object_data(dst_file)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "invalid VOL object")
 
     /* Set external flag if referenced file is not destination file */
     flags |= (src_f->shared != dst_f->shared) ? H5R_IS_EXTERNAL : 0;
@@ -315,11 +342,13 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5T__ref_mem_read(H5F_t H5_ATTR_UNUSED *src_f, const void *src_buf,
-    size_t H5_ATTR_UNUSED src_size, H5F_t *dst_f, void *dst_buf,
+H5T__ref_mem_read(H5VL_object_t H5_ATTR_UNUSED *src_file, const void *src_buf,
+    size_t H5_ATTR_UNUSED src_size, H5VL_object_t *dst_file, void *dst_buf,
     size_t dst_size)
 {
-    void *vol_obj = NULL;
+    H5F_t *src_f;
+    H5F_t *dst_f;
+    H5VL_object_t *vol_obj = NULL;
     const H5R_ref_priv_t *src_ref = (const H5R_ref_priv_t *)src_buf;
     unsigned flags = 0;
     herr_t ret_value = SUCCEED;
@@ -328,7 +357,7 @@ H5T__ref_mem_read(H5F_t H5_ATTR_UNUSED *src_f, const void *src_buf,
 
     HDassert(src_buf);
     HDassert(src_size == H5T_REF_MEM_SIZE);
-    HDassert(dst_f);
+    HDassert(dst_file);
     HDassert(dst_buf);
     HDassert(dst_size);
 
@@ -336,9 +365,14 @@ H5T__ref_mem_read(H5F_t H5_ATTR_UNUSED *src_f, const void *src_buf,
     if(NULL == (vol_obj = H5VL_vol_object(src_ref->loc_id)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "invalid location identifier")
 
-    /* Retrieve file from VOL object */
+    /* We should assert here that the terminal connector is H5VL_NATIVE once
+     * there is a facility to do so -NAF 2019/10/30 */
+
+    /* Retrieve files from VOL objects */
     if(NULL == (src_f = (H5F_t *)H5VL_object_data(vol_obj)))
         HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "invalid VOL object")
+    if(NULL == (dst_f = (H5F_t *)H5VL_object_data(dst_file)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "invalid VOL object")
 
     /* Set external flag if referenced file is not destination file */
     flags |= (src_f->shared != dst_f->shared) ? H5R_IS_EXTERNAL : 0;
@@ -349,7 +383,7 @@ H5T__ref_mem_read(H5F_t H5_ATTR_UNUSED *src_f, const void *src_buf,
         H5CX_set_libver_bounds(dst_f);
 
     /* Encode reference */
-    if(H5R__encode(H5F_ACTUAL_NAME(src_f), src_ref, dst_buf, &dst_size, flags) < 0)
+    if(H5R__encode(H5F_ACTUAL_NAME(src_f), src_ref, (unsigned char *)dst_buf, &dst_size, flags) < 0)
         HGOTO_ERROR(H5E_REFERENCE, H5E_CANTENCODE, FAIL, "Cannot encode reference")
 
 done:
@@ -367,22 +401,30 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5T__ref_mem_write(H5F_t *src_f, const void *src_buf, size_t src_size,
-    H5R_type_t src_type, H5F_t H5_ATTR_UNUSED *dst_f, void *dst_buf,
+H5T__ref_mem_write(H5VL_object_t *src_file, const void *src_buf, size_t src_size,
+    H5R_type_t src_type, H5VL_object_t H5_ATTR_UNUSED *dst_file, void *dst_buf,
     size_t dst_size, void H5_ATTR_UNUSED *bg_buf)
 {
+    H5F_t *src_f;
     hid_t file_id = H5I_INVALID_HID;
     H5R_ref_priv_t *dst_ref = (H5R_ref_priv_t *)dst_buf;
     herr_t ret_value = SUCCEED;
 
     FUNC_ENTER_STATIC
 
-    HDassert(src_f);
+    HDassert(src_file);
     HDassert(src_buf);
     HDassert(src_size);
     HDassert(dst_buf);
     HDassert(dst_size == H5T_REF_MEM_SIZE);
 
+    /* We should assert here that the terminal connector is H5VL_NATIVE once
+     * there is a facility to do so -NAF 2019/10/30 */
+
+    /* Retrieve file from VOL object */
+    if(NULL == (src_f = (H5F_t *)H5VL_object_data(src_file)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid VOL object")
+
     /* Make sure reference buffer is correctly initialized */
     HDmemset(dst_buf, 0, dst_size);
 
@@ -451,8 +493,8 @@ done:
  *-------------------------------------------------------------------------
  */
 static size_t
-H5T__ref_disk_getsize(H5F_t H5_ATTR_UNUSED *src_f, const void *src_buf,
-    size_t src_size, H5F_t H5_ATTR_UNUSED *dst_f, hbool_t *dst_copy)
+H5T__ref_disk_getsize(H5VL_object_t H5_ATTR_UNUSED *src_file, const void *src_buf,
+    size_t src_size, H5VL_object_t H5_ATTR_UNUSED *dst_file, hbool_t *dst_copy)
 {
     const uint8_t *p = (const uint8_t *)src_buf;
     unsigned flags;
@@ -499,50 +541,36 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5T__ref_disk_read(H5F_t *src_f, const void *src_buf, size_t src_size,
-    H5F_t H5_ATTR_UNUSED *dst_f, void *dst_buf, size_t dst_size)
+H5T__ref_disk_read(H5VL_object_t *src_file, const void *src_buf, size_t src_size,
+    H5VL_object_t H5_ATTR_UNUSED *dst_file, void *dst_buf, size_t dst_size)
 {
-    H5VL_object_t *vol_obj = NULL;  /* Object info */
-    hid_t file_id = H5I_INVALID_HID;
     const uint8_t *p = (const uint8_t *)src_buf;
     uint8_t *q = (uint8_t *)dst_buf;
-    size_t buf_size_left = src_size;
-    size_t expected_size = dst_size;
+    size_t blob_size = dst_size;
     herr_t ret_value = SUCCEED;
 
     FUNC_ENTER_STATIC
 
-    HDassert(src_f);
+    HDassert(src_file);
     HDassert(src_buf);
     HDassert(dst_buf);
     HDassert(dst_size);
 
-    /* TODO temporary hack to retrieve file object */
-    if((file_id = H5F__get_file_id(src_f, FALSE)) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-    if(NULL == (vol_obj = H5VL_vol_object(file_id)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid object identifier")
-
     /* Copy header manually */
     HDmemcpy(q, p, H5R_ENCODE_HEADER_SIZE);
     p += H5R_ENCODE_HEADER_SIZE;
     q += H5R_ENCODE_HEADER_SIZE;
-    expected_size -= H5R_ENCODE_HEADER_SIZE;
+    blob_size -= H5R_ENCODE_HEADER_SIZE;
 
     /* Skip the length of the sequence */
     p += H5_SIZEOF_UINT32_T;
-    HDassert(buf_size_left > H5_SIZEOF_UINT32_T);
-    buf_size_left -= H5_SIZEOF_UINT32_T;
+    HDassert(src_size > (H5R_ENCODE_HEADER_SIZE + H5_SIZEOF_UINT32_T));
 
     /* Retrieve blob */
-    if(H5VL_blob_get(vol_obj, p, q, &dst_size, NULL) < 0)
+    if(H5VL_blob_get(src_file, p, q, blob_size, NULL) < 0)
         HGOTO_ERROR(H5E_DATATYPE, H5E_CANTGET, FAIL, "unable to get blob")
-    if(dst_size != expected_size)
-        HGOTO_ERROR(H5E_REFERENCE, H5E_CANTDECODE, FAIL, "Expected data size does not match")
 
 done:
-    if((file_id != H5I_INVALID_HID) && (H5I_dec_ref(file_id) < 0))
-        HDONE_ERROR(H5E_DATATYPE, H5E_CANTDEC, FAIL, "unable to decrement refcount on file id")
     FUNC_LEAVE_NOAPI(ret_value)
 }   /* end H5T__ref_disk_read() */
 
@@ -557,12 +585,10 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5T__ref_disk_write(H5F_t H5_ATTR_UNUSED *src_f, const void *src_buf,
-    size_t src_size, H5R_type_t H5_ATTR_UNUSED src_type, H5F_t *dst_f,
+H5T__ref_disk_write(H5VL_object_t H5_ATTR_UNUSED *src_file, const void *src_buf,
+    size_t src_size, H5R_type_t H5_ATTR_UNUSED src_type, H5VL_object_t *dst_file,
     void *dst_buf, size_t dst_size, void *bg_buf)
 {
-    H5VL_object_t *vol_obj = NULL;  /* Object info */
-    hid_t file_id = H5I_INVALID_HID;
     const uint8_t *p = (const uint8_t *)src_buf;
     uint8_t *q = (uint8_t *)dst_buf;
     size_t buf_size_left = dst_size;
@@ -573,15 +599,9 @@ H5T__ref_disk_write(H5F_t H5_ATTR_UNUSED *src_f, const void *src_buf,
 
     HDassert(src_buf);
     HDassert(src_size);
-    HDassert(dst_f);
+    HDassert(dst_file);
     HDassert(dst_buf);
 
-    /* TODO temporary hack to retrieve file object */
-    if((file_id = H5F__get_file_id(dst_f, FALSE)) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-    if(NULL == (vol_obj = H5VL_vol_object(file_id)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid object identifier")
-
     /* TODO Should get rid of bg stuff */
     if(p_bg) {
         size_t p_buf_size_left = dst_size;
@@ -592,7 +612,7 @@ H5T__ref_disk_write(H5F_t H5_ATTR_UNUSED *src_f, const void *src_buf,
         p_buf_size_left -= H5_SIZEOF_UINT32_T;
 
         /* Remove blob for old data */
-        if(H5VL_blob_specific(vol_obj, (void *)p_bg, H5VL_BLOB_DELETE) < 0)
+        if(H5VL_blob_specific(dst_file, (void *)p_bg, H5VL_BLOB_DELETE) < 0)
             HGOTO_ERROR(H5E_DATATYPE, H5E_CANTREMOVE, FAIL, "unable to delete blob")
     } /* end if */
 
@@ -609,12 +629,10 @@ H5T__ref_disk_write(H5F_t H5_ATTR_UNUSED *src_f, const void *src_buf,
     buf_size_left -= H5_SIZEOF_UINT32_T;
 
     /* Store blob */
-    if(H5VL_blob_put(vol_obj, p, src_size, q, NULL) < 0)
+    if(H5VL_blob_put(dst_file, p, src_size, q, NULL) < 0)
         HGOTO_ERROR(H5E_DATATYPE, H5E_CANTSET, FAIL, "unable to put blob")
 
 done:
-    if((file_id != H5I_INVALID_HID) && (H5I_dec_ref(file_id) < 0))
-        HDONE_ERROR(H5E_DATATYPE, H5E_CANTDEC, FAIL, "unable to decrement refcount on file id")
     FUNC_LEAVE_NOAPI(ret_value)
 }   /* end H5T__ref_disk_write() */
 
@@ -629,20 +647,30 @@ done:
  *-------------------------------------------------------------------------
  */
 static size_t
-H5T__ref_obj_disk_getsize(H5F_t *src_f, const void H5_ATTR_UNUSED *src_buf,
-    size_t H5_ATTR_UNUSED src_size, H5F_t H5_ATTR_UNUSED *dst_f,
+H5T__ref_obj_disk_getsize(H5VL_object_t *src_file, const void H5_ATTR_UNUSED *src_buf,
+    size_t H5_ATTR_UNUSED src_size, H5VL_object_t H5_ATTR_UNUSED *dst_file,
     hbool_t H5_ATTR_UNUSED *dst_copy)
 {
+    H5F_t *src_f;
     size_t ret_value = 0;
 
-    FUNC_ENTER_STATIC_NOERR
+    FUNC_ENTER_STATIC
 
-    HDassert(src_f);
+    HDassert(src_file);
     HDassert(src_buf);
+
+    /* We should assert here that the terminal connector is H5VL_NATIVE once
+     * there is a facility to do so -NAF 2019/10/30 */
+
+    /* Retrieve file from VOL object */
+    if(NULL == (src_f = (H5F_t *)H5VL_object_data(src_file)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "invalid VOL object")
+
     HDassert(src_size == H5T_REF_OBJ_DISK_SIZE(src_f));
 
     ret_value = H5T_REF_OBJ_DISK_SIZE(src_f);
 
+done:
     FUNC_LEAVE_NOAPI(ret_value)
 }   /* end H5T__ref_obj_disk_getsize() */
 
@@ -657,22 +685,31 @@ H5T__ref_obj_disk_getsize(H5F_t *src_f, const void H5_ATTR_UNUSED *src_buf,
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5T__ref_obj_disk_read(H5F_t *src_f, const void *src_buf, size_t src_size,
-    H5F_t H5_ATTR_UNUSED *dst_f, void *dst_buf, size_t H5_ATTR_UNUSED dst_size)
+H5T__ref_obj_disk_read(H5VL_object_t *src_file, const void *src_buf, size_t src_size,
+    H5VL_object_t H5_ATTR_UNUSED *dst_file, void *dst_buf, size_t H5_ATTR_UNUSED dst_size)
 {
+    H5F_t *src_f;
     herr_t ret_value = SUCCEED;
 
     FUNC_ENTER_STATIC
 
-    HDassert(src_f);
+    HDassert(src_file);
     HDassert(src_buf);
-    HDassert(src_size == H5T_REF_OBJ_DISK_SIZE(src_f));
     HDassert(dst_buf);
+
+    /* We should assert here that the terminal connector is H5VL_NATIVE once
+     * there is a facility to do so -NAF 2019/10/30 */
+
+    /* Retrieve file from VOL object */
+    if(NULL == (src_f = (H5F_t *)H5VL_object_data(src_file)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid VOL object")
+
+    HDassert(src_size == H5T_REF_OBJ_DISK_SIZE(src_f));
     HDassert(dst_size == H5F_SIZEOF_ADDR(src_f));
 
     /* Get object address */
     if(H5R__decode_token_obj_compat((const unsigned char *)src_buf, &src_size,
-        dst_buf, H5F_SIZEOF_ADDR(src_f)) < 0)
+        (unsigned char *)dst_buf, H5F_SIZEOF_ADDR(src_f)) < 0)
         HGOTO_ERROR(H5E_REFERENCE, H5E_CANTDECODE, FAIL, "unable to get object address")
 
 done:
@@ -690,17 +727,32 @@ done:
  *-------------------------------------------------------------------------
  */
 static size_t
-H5T__ref_dsetreg_disk_getsize(H5F_t H5_ATTR_UNUSED *f,
+H5T__ref_dsetreg_disk_getsize(H5VL_object_t H5_ATTR_UNUSED *file,
     const void H5_ATTR_UNUSED *buf, size_t H5_ATTR_UNUSED buf_size,
-    H5F_t H5_ATTR_UNUSED *dst_f, hbool_t H5_ATTR_UNUSED *dst_copy)
+    H5VL_object_t H5_ATTR_UNUSED *dst_file, hbool_t H5_ATTR_UNUSED *dst_copy)
 {
     size_t ret_value = sizeof(struct H5Tref_dsetreg);
 
-    FUNC_ENTER_STATIC_NOERR
+    FUNC_ENTER_STATIC
 
     HDassert(buf);
-    HDassert(buf_size == H5T_REF_DSETREG_DISK_SIZE(f));
 
+#ifndef NDEBUG
+    {
+        H5F_t *f;
+
+        /* We should assert here that the terminal connector is H5VL_NATIVE once
+         * there is a facility to do so -NAF 2019/10/30 */
+
+        /* Retrieve file from VOL object */
+        if(NULL == (f = (H5F_t *)H5VL_object_data(file)))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, 0, "invalid VOL object")
+
+        HDassert(buf_size == H5T_REF_DSETREG_DISK_SIZE(f));
+    } /* end block */
+#endif /* NDEBUG */
+
+done:
     FUNC_LEAVE_NOAPI(ret_value)
 }   /* end H5T__ref_dsetreg_disk_getsize() */
 
@@ -715,20 +767,29 @@ H5T__ref_dsetreg_disk_getsize(H5F_t H5_ATTR_UNUSED *f,
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5T__ref_dsetreg_disk_read(H5F_t *src_f, const void *src_buf, size_t src_size,
-    H5F_t H5_ATTR_UNUSED *dst_f, void *dst_buf, size_t H5_ATTR_UNUSED dst_size)
+H5T__ref_dsetreg_disk_read(H5VL_object_t *src_file, const void *src_buf, size_t src_size,
+    H5VL_object_t H5_ATTR_UNUSED *dst_file, void *dst_buf, size_t H5_ATTR_UNUSED dst_size)
 {
+    H5F_t *src_f;
     struct H5Tref_dsetreg *dst_reg = (struct H5Tref_dsetreg *)dst_buf;
     herr_t ret_value = SUCCEED;
 
     FUNC_ENTER_STATIC
 
-    HDassert(src_f);
+    HDassert(src_file);
     HDassert(src_buf);
-    HDassert(src_size == H5T_REF_DSETREG_DISK_SIZE(src_f));
     HDassert(dst_buf);
     HDassert(dst_size == sizeof(struct H5Tref_dsetreg));
 
+    /* We should assert here that the terminal connector is H5VL_NATIVE once
+     * there is a facility to do so -NAF 2019/10/30 */
+
+    /* Retrieve file from VOL object */
+    if(NULL == (src_f = (H5F_t *)H5VL_object_data(src_file)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid VOL object")
+
+    HDassert(src_size == H5T_REF_DSETREG_DISK_SIZE(src_f));
+
     /* Retrieve object address and space */
     if(H5R__decode_token_region_compat(src_f, (const unsigned char *)src_buf,
         &src_size, &dst_reg->token, H5F_SIZEOF_ADDR(src_f), &dst_reg->space) < 0)
diff --git a/src/H5Tvlen.c b/src/H5Tvlen.c
index a76cfbf..ec84879 100644
--- a/src/H5Tvlen.c
+++ b/src/H5Tvlen.c
@@ -33,6 +33,7 @@
 #include "H5Iprivate.h"         /* IDs                  */
 #include "H5MMprivate.h"        /* Memory management    */
 #include "H5Tpkg.h"             /* Datatypes            */
+#include "H5VLprivate.h"        /* Virtual Object Layer                     */
 
 /****************/
 /* Local Macros */
@@ -54,28 +55,28 @@
 /********************/
 
 /* Memory-based VL sequence callbacks */
-static herr_t H5T__vlen_mem_seq_getlen(H5F_t *f, const void *_vl, size_t *len);
+static herr_t H5T__vlen_mem_seq_getlen(H5VL_object_t *file, const void *_vl, size_t *len);
 static void * H5T__vlen_mem_seq_getptr(void *_vl);
-static herr_t H5T__vlen_mem_seq_isnull(const H5F_t *f, void *_vl, hbool_t *isnull);
-static herr_t H5T__vlen_mem_seq_setnull(H5F_t *f, void *_vl, void *_bg);
-static herr_t H5T__vlen_mem_seq_read(H5F_t *f, void *_vl, void *_buf, size_t len);
-static herr_t H5T__vlen_mem_seq_write(H5F_t *f, const H5T_vlen_alloc_info_t *vl_alloc_info, void *_vl, void *_buf, void *_bg, size_t seq_len, size_t base_size);
+static herr_t H5T__vlen_mem_seq_isnull(const H5VL_object_t *file, void *_vl, hbool_t *isnull);
+static herr_t H5T__vlen_mem_seq_setnull(H5VL_object_t *file, void *_vl, void *_bg);
+static herr_t H5T__vlen_mem_seq_read(H5VL_object_t *file, void *_vl, void *_buf, size_t len);
+static herr_t H5T__vlen_mem_seq_write(H5VL_object_t *file, const H5T_vlen_alloc_info_t *vl_alloc_info, void *_vl, void *_buf, void *_bg, size_t seq_len, size_t base_size);
 
 /* Memory-based VL string callbacks */
-static herr_t H5T__vlen_mem_str_getlen(H5F_t *f, const void *_vl, size_t *len);
+static herr_t H5T__vlen_mem_str_getlen(H5VL_object_t *file, const void *_vl, size_t *len);
 static void * H5T__vlen_mem_str_getptr(void *_vl);
-static herr_t H5T__vlen_mem_str_isnull(const H5F_t *f, void *_vl, hbool_t *isnull);
-static herr_t H5T__vlen_mem_str_setnull(H5F_t *f, void *_vl, void *_bg);
-static herr_t H5T__vlen_mem_str_read(H5F_t *f, void *_vl, void *_buf, size_t len);
-static herr_t H5T__vlen_mem_str_write(H5F_t *f, const H5T_vlen_alloc_info_t *vl_alloc_info, void *_vl, void *_buf, void *_bg, size_t seq_len, size_t base_size);
+static herr_t H5T__vlen_mem_str_isnull(const H5VL_object_t *file, void *_vl, hbool_t *isnull);
+static herr_t H5T__vlen_mem_str_setnull(H5VL_object_t *file, void *_vl, void *_bg);
+static herr_t H5T__vlen_mem_str_read(H5VL_object_t *file, void *_vl, void *_buf, size_t len);
+static herr_t H5T__vlen_mem_str_write(H5VL_object_t *file, const H5T_vlen_alloc_info_t *vl_alloc_info, void *_vl, void *_buf, void *_bg, size_t seq_len, size_t base_size);
 
 /* Disk-based VL sequence (and string) callbacks */
-static herr_t H5T__vlen_disk_getlen(H5F_t *f, const void *_vl, size_t *len);
-static herr_t H5T__vlen_disk_isnull(const H5F_t *f, void *_vl, hbool_t *isnull);
-static herr_t H5T__vlen_disk_setnull(H5F_t *f, void *_vl, void *_bg);
-static herr_t H5T__vlen_disk_read(H5F_t *f, void *_vl, void *_buf, size_t len);
-static herr_t H5T__vlen_disk_write(H5F_t *f, const H5T_vlen_alloc_info_t *vl_alloc_info, void *_vl, void *_buf, void *_bg, size_t seq_len, size_t base_size);
-static herr_t H5T__vlen_disk_delete(H5F_t *f, const void *_vl);
+static herr_t H5T__vlen_disk_getlen(H5VL_object_t *file, const void *_vl, size_t *len);
+static herr_t H5T__vlen_disk_isnull(const H5VL_object_t *file, void *_vl, hbool_t *isnull);
+static herr_t H5T__vlen_disk_setnull(H5VL_object_t *file, void *_vl, void *_bg);
+static herr_t H5T__vlen_disk_read(H5VL_object_t *file, void *_vl, void *_buf, size_t len);
+static herr_t H5T__vlen_disk_write(H5VL_object_t *file, const H5T_vlen_alloc_info_t *vl_alloc_info, void *_vl, void *_buf, void *_bg, size_t seq_len, size_t base_size);
+static herr_t H5T__vlen_disk_delete(H5VL_object_t *file, const void *_vl);
 
 
 /*********************/
@@ -299,12 +300,13 @@ H5T__vlen_set_loc(const H5T_t *dt, H5VL_object_t *file, H5T_loc_t loc)
                 /* Mark this type as being stored on disk */
                 dt->shared->u.vlen.loc = H5T_LOC_DISK;
 
-                /*
-                 * Size of element on disk is 4 bytes for the length, plus the size
-                 * of an address in this file, plus 4 bytes for the size of a heap
-                 * ID.  Memory size is different.
-                 */
-                dt->shared->size = 4 + (size_t)H5F_SIZEOF_ADDR(f) + 4;
+                /* Get container info */
+                if(H5VL_file_get(file, H5VL_FILE_GET_CONT_INFO, H5P_DATASET_XFER_DEFAULT, H5_REQUEST_NULL, &cont_info) < 0)
+                    HGOTO_ERROR(H5E_DATATYPE, H5E_CANTGET, FAIL, "unable to get container info")
+
+                /* The datatype size is equal to 4 bytes for the sequence length
+                 * plus the size of a blob id */
+                dt->shared->size = 4 + cont_info.blob_id_size;
 
                 /* Set up the function pointers to access the VL information on disk */
                 /* VL sequences and VL strings are stored identically on disk, so use the same functions */
@@ -324,7 +326,7 @@ H5T__vlen_set_loc(const H5T_t *dt, H5VL_object_t *file, H5T_loc_t loc)
                 dt->shared->u.vlen.cls = NULL;
 
                 /* Reset file pointer */
-                dt->shared->u.vlen.f = NULL;
+                dt->shared->u.vlen.file = NULL;
                 break;
 
             case H5T_LOC_MAXLOC:
@@ -355,7 +357,7 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5T__vlen_mem_seq_getlen(H5F_t H5_ATTR_UNUSED *f, const void *_vl, size_t *len)
+H5T__vlen_mem_seq_getlen(H5VL_object_t H5_ATTR_UNUSED *file, const void *_vl, size_t *len)
 {
 #ifdef H5_NO_ALIGNMENT_RESTRICTIONS
     const hvl_t *vl = (const hvl_t *)_vl; /* Pointer to the user's hvl_t information */
@@ -431,7 +433,7 @@ H5T__vlen_mem_seq_getptr(void *_vl)
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5T__vlen_mem_seq_isnull(const H5F_t H5_ATTR_UNUSED *f, void *_vl, hbool_t *isnull)
+H5T__vlen_mem_seq_isnull(const H5VL_object_t H5_ATTR_UNUSED *file, void *_vl, hbool_t *isnull)
 {
 #ifdef H5_NO_ALIGNMENT_RESTRICTIONS
     const hvl_t *vl = (const hvl_t *)_vl;   /* Pointer to the user's hvl_t information */
@@ -469,7 +471,7 @@ H5T__vlen_mem_seq_isnull(const H5F_t H5_ATTR_UNUSED *f, void *_vl, hbool_t *isnu
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5T__vlen_mem_seq_setnull(H5F_t H5_ATTR_UNUSED *f, void *_vl, void H5_ATTR_UNUSED *_bg)
+H5T__vlen_mem_seq_setnull(H5VL_object_t H5_ATTR_UNUSED *file, void *_vl, void H5_ATTR_UNUSED *_bg)
 {
     hvl_t vl;                       /* Temporary hvl_t to use during operation */
 
@@ -502,7 +504,7 @@ H5T__vlen_mem_seq_setnull(H5F_t H5_ATTR_UNUSED *f, void *_vl, void H5_ATTR_UNUSE
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5T__vlen_mem_seq_read(H5F_t H5_ATTR_UNUSED *f, void *_vl, void *buf, size_t len)
+H5T__vlen_mem_seq_read(H5VL_object_t H5_ATTR_UNUSED *file, void *_vl, void *buf, size_t len)
 {
 #ifdef H5_NO_ALIGNMENT_RESTRICTIONS
     const hvl_t *vl = (const hvl_t *)_vl;   /* Pointer to the user's hvl_t information */
@@ -543,7 +545,7 @@ H5T__vlen_mem_seq_read(H5F_t H5_ATTR_UNUSED *f, void *_vl, void *buf, size_t len
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5T__vlen_mem_seq_write(H5F_t H5_ATTR_UNUSED *f, const H5T_vlen_alloc_info_t *vl_alloc_info, void *_vl, void *buf, void H5_ATTR_UNUSED *_bg, size_t seq_len, size_t base_size)
+H5T__vlen_mem_seq_write(H5VL_object_t H5_ATTR_UNUSED *file, const H5T_vlen_alloc_info_t *vl_alloc_info, void *_vl, void *buf, void H5_ATTR_UNUSED *_bg, size_t seq_len, size_t base_size)
 {
     hvl_t vl;                       /* Temporary hvl_t to use during operation */
     herr_t ret_value = SUCCEED;     /* Return value */
@@ -596,7 +598,7 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5T__vlen_mem_str_getlen(H5F_t H5_ATTR_UNUSED *f, const void *_vl, size_t *len)
+H5T__vlen_mem_str_getlen(H5VL_object_t H5_ATTR_UNUSED *file, const void *_vl, size_t *len)
 {
 #ifdef H5_NO_ALIGNMENT_RESTRICTIONS
     const char *s = *(const char * const *)_vl; /* Pointer to the user's string information */
@@ -667,7 +669,7 @@ H5T__vlen_mem_str_getptr(void *_vl)
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5T__vlen_mem_str_isnull(const H5F_t H5_ATTR_UNUSED *f, void *_vl, hbool_t *isnull)
+H5T__vlen_mem_str_isnull(const H5VL_object_t H5_ATTR_UNUSED *file, void *_vl, hbool_t *isnull)
 {
 #ifdef H5_NO_ALIGNMENT_RESTRICTIONS
     char *s = *(char **)_vl;   /* Pointer to the user's string information */
@@ -700,7 +702,7 @@ H5T__vlen_mem_str_isnull(const H5F_t H5_ATTR_UNUSED *f, void *_vl, hbool_t *isnu
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5T__vlen_mem_str_setnull(H5F_t H5_ATTR_UNUSED *f, void *_vl, void H5_ATTR_UNUSED *_bg)
+H5T__vlen_mem_str_setnull(H5VL_object_t H5_ATTR_UNUSED *file, void *_vl, void H5_ATTR_UNUSED *_bg)
 {
     char *t = NULL;                   /* Pointer to temporary buffer allocated */
 
@@ -726,7 +728,7 @@ H5T__vlen_mem_str_setnull(H5F_t H5_ATTR_UNUSED *f, void *_vl, void H5_ATTR_UNUSE
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5T__vlen_mem_str_read(H5F_t H5_ATTR_UNUSED *f, void *_vl, void *buf, size_t len)
+H5T__vlen_mem_str_read(H5VL_object_t H5_ATTR_UNUSED *file, void *_vl, void *buf, size_t len)
 {
 #ifdef H5_NO_ALIGNMENT_RESTRICTIONS
     char *s = *(char **)_vl;   /* Pointer to the user's string information */
@@ -766,7 +768,7 @@ H5T__vlen_mem_str_read(H5F_t H5_ATTR_UNUSED *f, void *_vl, void *buf, size_t len
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5T__vlen_mem_str_write(H5F_t H5_ATTR_UNUSED *f, const H5T_vlen_alloc_info_t *vl_alloc_info,
+H5T__vlen_mem_str_write(H5VL_object_t H5_ATTR_UNUSED *file, const H5T_vlen_alloc_info_t *vl_alloc_info,
     void *_vl, void *buf, void H5_ATTR_UNUSED *_bg, size_t seq_len, size_t base_size)
 {
     char *t;                        /* Pointer to temporary buffer allocated */
@@ -813,7 +815,7 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5T__vlen_disk_getlen(H5F_t H5_ATTR_UNUSED *f, const void *_vl, size_t *seq_len)
+H5T__vlen_disk_getlen(H5VL_object_t H5_ATTR_UNUSED *file, const void *_vl, size_t *seq_len)
 {
     const uint8_t *vl = (const uint8_t *)_vl; /* Pointer to the user's hvl_t information */
 
@@ -843,36 +845,26 @@ H5T__vlen_disk_getlen(H5F_t H5_ATTR_UNUSED *f, const void *_vl, size_t *seq_len)
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5T__vlen_disk_isnull(const H5F_t *f, void *_vl, hbool_t *isnull)
+H5T__vlen_disk_isnull(const H5VL_object_t *file, void *_vl, hbool_t *isnull)
 {
-    H5VL_object_t *vol_obj = NULL;/* Object info */
-    hid_t file_id = H5I_INVALID_HID;
     uint8_t *vl = (uint8_t *)_vl; /* Pointer to the user's hvl_t information */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_STATIC
 
     /* Check parameters */
-    HDassert(f);
+    HDassert(file);
     HDassert(vl);
     HDassert(isnull);
 
     /* Skip the sequence's length */
     vl += 4;
 
-    /* TODO temporary hack to retrieve file object */
-    if((file_id = H5F__get_file_id((H5F_t *)f, FALSE)) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-    if(NULL == (vol_obj = H5VL_vol_object(file_id)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid object identifier")
-
     /* Check if blob ID is "nil" */
-    if(H5VL_blob_specific(vol_obj, vl, H5VL_BLOB_ISNULL, isnull) < 0)
+    if(H5VL_blob_specific(file, vl, H5VL_BLOB_ISNULL, isnull) < 0)
         HGOTO_ERROR(H5E_DATATYPE, H5E_CANTGET, FAIL, "unable to check if a blob ID is 'nil'")
 
 done:
-    if((file_id != H5I_INVALID_HID) && (H5I_dec_ref(file_id) < 0))
-        HDONE_ERROR(H5E_DATATYPE, H5E_CANTDEC, FAIL, "unable to decrement refcount on file id")
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5T__vlen_disk_isnull() */
 
@@ -890,41 +882,31 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5T__vlen_disk_setnull(H5F_t *f, void *_vl, void *bg)
+H5T__vlen_disk_setnull(H5VL_object_t *file, void *_vl, void *bg)
 {
-    H5VL_object_t *vol_obj = NULL;/* Object info */
-    hid_t file_id = H5I_INVALID_HID;
     uint8_t *vl = (uint8_t *)_vl; /* Pointer to the user's hvl_t information */
     herr_t ret_value = SUCCEED;   /* Return value */
 
     FUNC_ENTER_STATIC
 
     /* check parameters */
-    HDassert(f);
+    HDassert(file);
     HDassert(vl);
 
     /* Free heap object for old data */
     if(bg != NULL)
         /* Delete sequence in destination location */
-        if(H5T__vlen_disk_delete(f, bg) < 0)
+        if(H5T__vlen_disk_delete(file, bg) < 0)
             HGOTO_ERROR(H5E_DATATYPE, H5E_CANTREMOVE, FAIL, "unable to remove background heap object")
 
     /* Set the length of the sequence */
     UINT32ENCODE(vl, 0);
 
-    /* TODO temporary hack to retrieve file object */
-    if((file_id = H5F__get_file_id(f, FALSE)) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-    if(NULL == (vol_obj = H5VL_vol_object(file_id)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid object identifier")
-
     /* Set blob ID to "nil" */
-    if(H5VL_blob_specific(vol_obj, vl, H5VL_BLOB_SETNULL) < 0)
+    if(H5VL_blob_specific(file, vl, H5VL_BLOB_SETNULL) < 0)
         HGOTO_ERROR(H5E_DATATYPE, H5E_CANTSET, FAIL, "unable to set a blob ID to 'nil'")
 
 done:
-    if((file_id != H5I_INVALID_HID) && (H5I_dec_ref(file_id) < 0))
-        HDONE_ERROR(H5E_DATATYPE, H5E_CANTDEC, FAIL, "unable to decrement refcount on file id")
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5T__vlen_disk_setnull() */
 
@@ -942,36 +924,26 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5T__vlen_disk_read(H5F_t *f, void *_vl, void *buf, size_t H5_ATTR_UNUSED len)
+H5T__vlen_disk_read(H5VL_object_t *file, void *_vl, void *buf, size_t len)
 {
-    H5VL_object_t *vol_obj = NULL;/* Object info */
-    hid_t file_id = H5I_INVALID_HID;
     const uint8_t *vl = (const uint8_t *)_vl; /* Pointer to the user's hvl_t information */
     herr_t ret_value = SUCCEED;     /* Return value */
 
     FUNC_ENTER_STATIC
 
     /* Check parameters */
-    HDassert(f);
+    HDassert(file);
     HDassert(vl);
     HDassert(buf);
 
     /* Skip the length of the sequence */
     vl += 4;
 
-    /* TODO temporary hack to retrieve file object */
-    if((file_id = H5F__get_file_id(f, FALSE)) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-    if(NULL == (vol_obj = H5VL_vol_object(file_id)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid object identifier")
-
     /* Retrieve blob */
-    if(H5VL_blob_get(vol_obj, vl, buf, NULL, NULL) < 0)
+    if(H5VL_blob_get(file, vl, buf, len, NULL) < 0)
         HGOTO_ERROR(H5E_DATATYPE, H5E_CANTGET, FAIL, "unable to get blob")
 
 done:
-    if((file_id != H5I_INVALID_HID) && (H5I_dec_ref(file_id) < 0))
-        HDONE_ERROR(H5E_DATATYPE, H5E_CANTDEC, FAIL, "unable to decrement refcount on file id")
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5T__vlen_disk_read() */
 
@@ -989,11 +961,10 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5T__vlen_disk_write(H5F_t *f, const H5T_vlen_alloc_info_t H5_ATTR_UNUSED *vl_alloc_info,
-    void *_vl, void *buf, void *_bg, size_t seq_len, size_t base_size)
+H5T__vlen_disk_write(H5VL_object_t *file,
+    const H5T_vlen_alloc_info_t H5_ATTR_UNUSED *vl_alloc_info, void *_vl,
+    void *buf, void *_bg, size_t seq_len, size_t base_size)
 {
-    H5VL_object_t *vol_obj = NULL;      /* Object info */
-    hid_t file_id = H5I_INVALID_HID;
     uint8_t *vl = (uint8_t *)_vl;       /* Pointer to the user's hvl_t information */
     const uint8_t *bg = (const uint8_t *)_bg; /* Pointer to the old data hvl_t */
     herr_t ret_value = SUCCEED;         /* Return value */
@@ -1007,25 +978,17 @@ H5T__vlen_disk_write(H5F_t *f, const H5T_vlen_alloc_info_t H5_ATTR_UNUSED *vl_al
 
     /* Free heap object for old data, if non-NULL */
     if(bg != NULL)
-        if(H5T__vlen_disk_delete(f, bg) < 0)
+        if(H5T__vlen_disk_delete(file, bg) < 0)
             HGOTO_ERROR(H5E_DATATYPE, H5E_CANTREMOVE, FAIL, "unable to remove background heap object")
 
     /* Set the length of the sequence */
     UINT32ENCODE(vl, seq_len);
 
-    /* TODO temporary hack to retrieve file object */
-    if((file_id = H5F__get_file_id(f, FALSE)) < 0)
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-    if(NULL == (vol_obj = H5VL_vol_object(file_id)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid object identifier")
-
     /* Store blob */
-    if(H5VL_blob_put(vol_obj, buf, (seq_len * base_size), vl, NULL) < 0)
+    if(H5VL_blob_put(file, buf, (seq_len * base_size), vl, NULL) < 0)
         HGOTO_ERROR(H5E_DATATYPE, H5E_CANTSET, FAIL, "unable to put blob")
 
 done:
-    if((file_id != H5I_INVALID_HID) && (H5I_dec_ref(file_id) < 0))
-        HDONE_ERROR(H5E_DATATYPE, H5E_CANTDEC, FAIL, "unable to decrement refcount on file id")
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5T__vlen_disk_write() */
 
@@ -1043,16 +1006,15 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5T__vlen_disk_delete(H5F_t *f, const void *_vl)
+H5T__vlen_disk_delete(H5VL_object_t *file, const void *_vl)
 {
     const uint8_t *vl = (const uint8_t *)_vl; /* Pointer to the user's hvl_t information */
-    hid_t file_id = H5I_INVALID_HID;
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_STATIC
 
     /* Check parameters */
-    HDassert(f);
+    HDassert(file);
 
     /* Free heap object for old data */
     if(vl != NULL) {
@@ -1062,23 +1024,12 @@ H5T__vlen_disk_delete(H5F_t *f, const void *_vl)
         UINT32DECODE(vl, seq_len);
 
         /* Delete object, if length > 0 */
-        if(seq_len > 0) {
-            H5VL_object_t *vol_obj = NULL; /* Object info */
-
-            /* TODO temporary hack to retrieve file object */
-            if((file_id = H5F__get_file_id(f, FALSE)) < 0)
-                HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file or file object")
-            if(NULL == (vol_obj = H5VL_vol_object(file_id)))
-                HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "invalid object identifier")
-
-            if(H5VL_blob_specific(vol_obj, (void *)vl, H5VL_BLOB_DELETE) < 0)   /* Casting away 'const' OK -QAK */
+        if(seq_len > 0)
+            if(H5VL_blob_specific(file, (void *)vl, H5VL_BLOB_DELETE) < 0)   /* Casting away 'const' OK -QAK */
                 HGOTO_ERROR(H5E_DATATYPE, H5E_CANTREMOVE, FAIL, "unable to delete blob")
-        }
     } /* end if */
 
 done:
-    if((file_id != H5I_INVALID_HID) && (H5I_dec_ref(file_id) < 0))
-        HDONE_ERROR(H5E_DATATYPE, H5E_CANTDEC, FAIL, "unable to decrement refcount on file id")
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5T__vlen_disk_delete() */
 
diff --git a/src/H5VLcallback.c b/src/H5VLcallback.c
index 1990c81..8d7368b 100644
--- a/src/H5VLcallback.c
+++ b/src/H5VLcallback.c
@@ -180,7 +180,7 @@ static herr_t H5VL__request_free(void *req, const H5VL_class_t *cls);
 static herr_t H5VL__blob_put(void *obj, const H5VL_class_t *cls,
     const void *buf, size_t size, void *blob_id, void *ctx);
 static herr_t H5VL__blob_get(void *obj, const H5VL_class_t *cls,
-    const void *blob_id, void *buf, size_t *size, void *ctx);
+    const void *blob_id, void *buf, size_t size, void *ctx);
 static herr_t H5VL__blob_specific(void *obj, const H5VL_class_t *cls,
     void *blob_id, H5VL_blob_specific_t specific_type, va_list arguments);
 
@@ -6692,7 +6692,7 @@ done:
  */
 static herr_t
 H5VL__blob_get(void *obj, const H5VL_class_t *cls, const void *blob_id,
-    void *buf, size_t *size, void *ctx)
+    void *buf, size_t size, void *ctx)
 {
     herr_t ret_value = SUCCEED;         /* Return value */
 
@@ -6702,7 +6702,7 @@ H5VL__blob_get(void *obj, const H5VL_class_t *cls, const void *blob_id,
     HDassert(obj);
     HDassert(cls);
     HDassert(blob_id);
-    HDassert(size || buf);
+    HDassert(buf);
 
     /* Check if the corresponding VOL callback exists */
     if(NULL == cls->blob_cls.get)
@@ -6728,7 +6728,7 @@ done:
  */
 herr_t
 H5VL_blob_get(const H5VL_object_t *vol_obj, const void *blob_id, void *buf,
-    size_t *size, void *ctx)
+    size_t size, void *ctx)
 {
     hbool_t vol_wrapper_set = FALSE;    /* Whether the VOL object wrapping context was set up */
     herr_t ret_value = SUCCEED;         /* Return value */
@@ -6738,7 +6738,7 @@ H5VL_blob_get(const H5VL_object_t *vol_obj, const void *blob_id, void *buf,
     /* Sanity check */
     HDassert(vol_obj);
     HDassert(blob_id);
-    HDassert(size || buf);
+    HDassert(buf);
 
     /* Set wrapper info in API context */
     if(H5VL_set_vol_wrapper(vol_obj->data, vol_obj->connector) < 0)
@@ -6768,13 +6768,13 @@ done:
  */
 herr_t
 H5VLblob_get(void *obj, hid_t connector_id, const void *blob_id, void *buf,
-    size_t *size, void *ctx)
+    size_t size, void *ctx)
 {
     H5VL_class_t *cls;                  /* VOL connector's class struct */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_API_NOINIT
-    H5TRACE6("e", "*xi*x*x*z*x", obj, connector_id, blob_id, buf, size, ctx);
+    H5TRACE6("e", "*xi*x*xz*x", obj, connector_id, blob_id, buf, size, ctx);
 
     /* Get class pointer */
     if(NULL == obj)
diff --git a/src/H5VLconnector.h b/src/H5VLconnector.h
index b1a8054..13cb2b5 100644
--- a/src/H5VLconnector.h
+++ b/src/H5VLconnector.h
@@ -381,7 +381,7 @@ typedef struct H5VL_request_class_t {
 /* 'blob' routines */
 typedef struct H5VL_blob_class_t {
     herr_t (*put)(void *obj, const void *buf, size_t size, void *blob_id, void *ctx);
-    herr_t (*get)(void *obj, const void *blob_id, void *buf, size_t *size, void *ctx);
+    herr_t (*get)(void *obj, const void *blob_id, void *buf, size_t size, void *ctx);
     herr_t (*specific)(void *obj, void *blob_id, H5VL_blob_specific_t specific_type, va_list arguments);
     herr_t (*optional)(void *obj, void *blob_id, va_list arguments);
 } H5VL_blob_class_t;
diff --git a/src/H5VLconnector_passthru.h b/src/H5VLconnector_passthru.h
index d0d73d2..a4c8742 100644
--- a/src/H5VLconnector_passthru.h
+++ b/src/H5VLconnector_passthru.h
@@ -160,7 +160,7 @@ H5_DLL herr_t H5VLrequest_free(void *req, hid_t connector_id);
 
 /* Public wrappers for blob callbacks */
 H5_DLL herr_t H5VLblob_put(void *obj, hid_t connector_id, const void *buf, size_t size, void *blob_id, void *ctx);
-H5_DLL herr_t H5VLblob_get(void *obj, hid_t connector_id, const void *blob_id, void *buf, size_t *size, void *ctx);
+H5_DLL herr_t H5VLblob_get(void *obj, hid_t connector_id, const void *blob_id, void *buf, size_t size, void *ctx);
 H5_DLL herr_t H5VLblob_specific(void *obj, hid_t connector_id, void *blob_id, H5VL_blob_specific_t specific_type, va_list arguments);
 
 /* Public wrappers for generic 'optional' callback */
diff --git a/src/H5VLnative_blob.c b/src/H5VLnative_blob.c
index b16b407..6c7f9b2 100644
--- a/src/H5VLnative_blob.c
+++ b/src/H5VLnative_blob.c
@@ -109,12 +109,13 @@ done:
  *-------------------------------------------------------------------------
  */
 herr_t
-H5VL__native_blob_get(void *obj, const void *blob_id, void *buf, size_t *size,
+H5VL__native_blob_get(void *obj, const void *blob_id, void *buf, size_t size,
     void H5_ATTR_UNUSED *ctx)
 {
     H5F_t *f = (H5F_t *)obj;            /* Retrieve file pointer */
     const uint8_t *id = (const uint8_t *)blob_id; /* Pointer to the disk blob ID */
     H5HG_t hobjid;                      /* Global heap ID for sequence */
+    size_t hobj_size;                   /* Global heap object size returned from H5HG_read() */
     herr_t ret_value = SUCCEED;         /* Return value */
 
     FUNC_ENTER_PACKAGE
@@ -131,9 +132,13 @@ H5VL__native_blob_get(void *obj, const void *blob_id, void *buf, size_t *size,
     /* Check if this sequence actually has any data */
     if(hobjid.addr > 0)
         /* Read the VL information from disk */
-        if(NULL == H5HG_read(f, &hobjid, buf, size))
+        if(NULL == H5HG_read(f, &hobjid, buf, &hobj_size))
             HGOTO_ERROR(H5E_VOL, H5E_READERROR, FAIL, "unable to read VL information")
 
+    /* Verify the size is correct */
+    if(hobj_size != size)
+        HGOTO_ERROR(H5E_VOL, H5E_CANTDECODE, FAIL, "Expected global heap object size does not match")
+
 done:
     FUNC_LEAVE_NOAPI(ret_value)
 } /* end H5VL__native_blob_get() */
@@ -175,7 +180,7 @@ H5VL__native_blob_specific(void *obj, void *blob_id,
                 H5F_addr_decode(f, &id, &(hobjid.addr));
                 UINT32DECODE(id, hobjid.idx);
 
-                /* Free heap object */
+                /* Get heap object's size */
                 if(hobjid.addr > 0) {
                     if(H5HG_get_obj_size(f, &hobjid, size) < 0)
                         HGOTO_ERROR(H5E_VOL, H5E_CANTREMOVE, FAIL, "unable to remove heap object")
diff --git a/src/H5VLnative_private.h b/src/H5VLnative_private.h
index 5ed0b1f..69a057e 100644
--- a/src/H5VLnative_private.h
+++ b/src/H5VLnative_private.h
@@ -103,7 +103,7 @@ H5_DLL herr_t H5VL__native_datatype_close(void *dt, hid_t dxpl_id, void **req);
 
 /* Blob callbacks */
 H5_DLL herr_t H5VL__native_blob_put(void *obj, const void *buf, size_t size, void *blob_id, void *ctx);
-H5_DLL herr_t H5VL__native_blob_get(void *obj, const void *blob_id, void *buf, size_t *size, void *ctx);
+H5_DLL herr_t H5VL__native_blob_get(void *obj, const void *blob_id, void *buf, size_t size, void *ctx);
 H5_DLL herr_t H5VL__native_blob_specific(void *obj, void *blob_id, H5VL_blob_specific_t specific_type, va_list arguments);
 
 #ifdef __cplusplus
diff --git a/src/H5VLpassthru.c b/src/H5VLpassthru.c
index 8e395e6..d9a207f 100644
--- a/src/H5VLpassthru.c
+++ b/src/H5VLpassthru.c
@@ -180,7 +180,7 @@ static herr_t H5VL_pass_through_request_free(void *req);
 
 /* Blob callbacks */
 static herr_t H5VL_pass_through_blob_put(void *obj, const void *buf, size_t size, void *blob_id, void *ctx);
-static herr_t H5VL_pass_through_blob_get(void *obj, const void *blob_id, void *buf, size_t *size, void *ctx);
+static herr_t H5VL_pass_through_blob_get(void *obj, const void *blob_id, void *buf, size_t size, void *ctx);
 static herr_t H5VL_pass_through_blob_specific(void *obj, void *blob_id, H5VL_blob_specific_t specific_type, va_list arguments);
 
 
@@ -2885,7 +2885,7 @@ H5VL_pass_through_blob_put(void *obj, const void *buf, size_t size,
  */
 herr_t
 H5VL_pass_through_blob_get(void *obj, const void *blob_id, void *buf,
-    size_t *size, void *ctx)
+    size_t size, void *ctx)
 {
     H5VL_pass_through_t *o = (H5VL_pass_through_t *)obj;
     herr_t ret_value;
diff --git a/src/H5VLprivate.h b/src/H5VLprivate.h
index 2449bdf..c572b79 100644
--- a/src/H5VLprivate.h
+++ b/src/H5VLprivate.h
@@ -196,7 +196,7 @@ H5_DLL herr_t H5VL_request_free(const H5VL_object_t *vol_obj);
 
 /* Blob functions */
 H5_DLL herr_t H5VL_blob_put(const H5VL_object_t *vol_obj, const void *buf, size_t size, void *blob_id, void *ctx);
-H5_DLL herr_t H5VL_blob_get(const H5VL_object_t *vol_obj, const void *blob_id, void *buf, size_t *size, void *ctx);
+H5_DLL herr_t H5VL_blob_get(const H5VL_object_t *vol_obj, const void *blob_id, void *buf, size_t size, void *ctx);
 H5_DLL herr_t H5VL_blob_specific(const H5VL_object_t *vol_obj, void *blob_id, H5VL_blob_specific_t specific_type, ...);
 
 /* Generic functions */