[svn-r27237] Description:

    Merge v3 metadata cache changes to trunk.  Yay! :-)

Tested on:
    MacOSX/64 10.10.3 (amazon) w/serial & parallel
    Linux/32 2.6.x (jam) w/serial & parallel
    (daily tested on branch)

1 files changed, 752 insertions, 687 deletions

diff --git a/src/H5Fsuper_cache.c b/src/H5Fsuper_cache.c
index ded845d..cf14770 100644
--- a/src/H5Fsuper_cache.c
+++ b/src/H5Fsuper_cache.c
@@ -51,9 +51,6 @@
 /* Local Macros */
 /****************/
 
-/* Maximum size of super-block buffers */
-#define H5F_MAX_SUPERBLOCK_SIZE  134
-
 
 /******************/
 /* Local Typedefs */
@@ -70,28 +67,70 @@
 /********************/
 
 /* Metadata cache (H5AC) callbacks */
-static H5F_super_t *H5F_sblock_load(H5F_t *f, hid_t dxpl_id, haddr_t addr, void *udata);
-static herr_t H5F_sblock_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t addr, H5F_super_t *sblock);
-static herr_t H5F_sblock_dest(H5F_t *f, H5F_super_t * sblock);
-static herr_t H5F_sblock_clear(H5F_t *f, H5F_super_t *sblock, hbool_t destroy);
-static herr_t H5F_sblock_size(const H5F_t *f, const H5F_super_t *sblock, size_t *size_ptr);
+static herr_t H5F__cache_superblock_get_load_size(const void *udata, size_t *image_len);
+static void *H5F__cache_superblock_deserialize(const void *image, size_t len,
+    void *udata, hbool_t *dirty);
+static herr_t H5F__cache_superblock_image_len(const void *thing, 
+    size_t *image_len, hbool_t *compressed_ptr, 
+    size_t *compressed_image_len_ptr);
+static herr_t H5F__cache_superblock_pre_serialize(const H5F_t *f, 
+    hid_t dxpl_id, void *thing, haddr_t addr, size_t len, 
+    size_t compressed_len, haddr_t *new_addr, size_t *new_len, 
+    size_t *new_compressed_len, unsigned *flags);
+static herr_t H5F__cache_superblock_serialize(const H5F_t *f, void *image, size_t len,
+    void *thing);
+static herr_t H5F__cache_superblock_free_icr(void *thing);
+
+static herr_t H5F__cache_drvrinfo_get_load_size(const void *udata, size_t *image_len);
+static void *H5F__cache_drvrinfo_deserialize(const void *image, size_t len,
+    void *udata, hbool_t *dirty);
+static herr_t H5F__cache_drvrinfo_image_len(const void *thing, 
+    size_t *image_len, hbool_t *compressed_ptr, 
+    size_t *compressed_image_len_ptr);
+static herr_t H5F__cache_drvrinfo_serialize(const H5F_t *f, void *image, size_t len,
+    void *thing);
+static herr_t H5F__cache_drvrinfo_free_icr(void *thing);
 
 
 /*********************/
 /* Package Variables */
 /*********************/
 
-/* H5F inherits cache-like properties from H5AC */
+/* H5F superblock inherits cache-like properties from H5AC */
 const H5AC_class_t H5AC_SUPERBLOCK[1] = {{
-    H5AC_SUPERBLOCK_ID,
-    (H5AC_load_func_t)H5F_sblock_load,
-    (H5AC_flush_func_t)H5F_sblock_flush,
-    (H5AC_dest_func_t)H5F_sblock_dest,
-    (H5AC_clear_func_t)H5F_sblock_clear,
-    (H5AC_notify_func_t)NULL,
-    (H5AC_size_func_t)H5F_sblock_size,
+    H5AC_SUPERBLOCK_ID,                 /* Metadata client ID */
+    "Superblock",                       /* Metadata client name (for debugging) */
+    H5FD_MEM_SUPER,                     /* File space memory type for client */
+    H5AC__CLASS_SPECULATIVE_LOAD_FLAG,  /* Client class behavior flags */
+    H5F__cache_superblock_get_load_size,/* 'get_load_size' callback */
+    H5F__cache_superblock_deserialize,  /* 'deserialize' callback */
+    H5F__cache_superblock_image_len,    /* 'image_len' callback */
+    H5F__cache_superblock_pre_serialize,/* 'pre_serialize' callback */
+    H5F__cache_superblock_serialize,    /* 'serialize' callback */
+    NULL,                               /* 'notify' callback */
+    H5F__cache_superblock_free_icr,     /* 'free_icr' callback */
+    NULL,				/* 'clear' callback */
+    NULL,                               /* 'fsf_size' callback */
+}};
+
+/* H5F driver info block inherits cache-like properties from H5AC */
+const H5AC_class_t H5AC_DRVRINFO[1] = {{
+    H5AC_DRVRINFO_ID,                   /* Metadata client ID */
+    "Driver info block",                /* Metadata client name (for debugging) */
+    H5FD_MEM_SUPER,                     /* File space memory type for client */
+    H5AC__CLASS_SPECULATIVE_LOAD_FLAG,  /* Client class behavior flags */
+    H5F__cache_drvrinfo_get_load_size,  /* 'get_load_size' callback */
+    H5F__cache_drvrinfo_deserialize,    /* 'deserialize' callback */
+    H5F__cache_drvrinfo_image_len,      /* 'image_len' callback */
+    NULL,                               /* 'pre_serialize' callback */
+    H5F__cache_drvrinfo_serialize,      /* 'serialize' callback */
+    NULL,                               /* 'notify' callback */
+    H5F__cache_drvrinfo_free_icr,       /* 'free_icr' callback */
+    NULL,				/* 'clear' callback */
+    NULL,                               /* 'fsf_size' callback */
 }};
 
+
 /*****************************/
 /* Library Private Variables */
 /*****************************/
@@ -107,546 +146,470 @@ H5FL_EXTERN(H5F_super_t);
 
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_sblock_load
+ * Function:    H5F__cache_superblock_get_load_size
  *
- * Purpose:     Loads the superblock from the file, and deserializes
- *              its information into the H5F_super_t structure.
+ * Purpose:     Compute the size of the data structure on disk.
  *
- * Return:      Success:        SUCCEED
- *              Failure:        NULL
+ * Return:      Non-negative on success/Negative on failure
  *
- * Programmer:  Mike McGreevy
- *              mamcgree@hdfgroup.org
- *              April 8, 2009
+ * Programmer:  Quincey Koziol
+ *              koziol@hdfgroup.org
+ *              July 17, 2013
  *
  *-------------------------------------------------------------------------
  */
-static H5F_super_t *
-H5F_sblock_load(H5F_t *f, hid_t dxpl_id, haddr_t H5_ATTR_UNUSED addr, void *_udata)
+static herr_t
+H5F__cache_superblock_get_load_size(const void H5_ATTR_UNUSED *udata, size_t *image_len)
 {
-    H5F_super_t        *sblock = NULL;      /* File's superblock */
-    haddr_t             base_addr = HADDR_UNDEF;        /* Base address of file */
-    uint8_t             sbuf[H5F_MAX_SUPERBLOCK_SIZE];     /* Buffer for superblock */
-    H5P_genplist_t     *dxpl;               /* DXPL object */
-    H5P_genplist_t     *c_plist;            /* File creation property list  */
-    H5F_file_t         *shared;             /* shared part of `file'        */
-    H5FD_t             *lf;                 /* file driver part of `shared' */
-    haddr_t             stored_eof;         /* stored end-of-file address in file  */
-    haddr_t             eof;                /* end of file address           */
-    uint8_t             sizeof_addr;        /* Size of offsets in the file (in bytes) */
-    uint8_t             sizeof_size;        /* Size of lengths in the file (in bytes) */
-    const size_t        fixed_size = H5F_SUPERBLOCK_FIXED_SIZE; /*fixed sizeof superblock   */
-    size_t              variable_size;      /*variable sizeof superblock    */
-    uint8_t            *p;                  /* Temporary pointer into encoding buffer */
-    unsigned            super_vers;         /* Superblock version          */
-    hbool_t            *dirtied = (hbool_t *)_udata;  /* Set up dirtied out value */
-    H5F_super_t        *ret_value;          /* Return value */
-
-    FUNC_ENTER_NOAPI_NOINIT
+    FUNC_ENTER_STATIC_NOERR
 
     /* Check arguments */
-    HDassert(f);
-    HDassert(H5F_addr_eq(addr, 0));
-    HDassert(dirtied);
+    HDassert(image_len);
 
-    /* Short cuts */
-    shared = f->shared;
-    lf = shared->lf;
+    /* Set the initial image length size */
+    *image_len = H5F_SUPERBLOCK_FIXED_SIZE +    /* Fixed size of superblock */
+        H5F_SUPERBLOCK_MINIMAL_VARLEN_SIZE;
 
-    /* Get the shared file creation property list */
-    if(NULL == (c_plist = (H5P_genplist_t *)H5I_object(shared->fcpl_id)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "can't get property list")
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5F__cache_superblock_get_load_size() */
 
-    /* Get the base address for the file in the VFD */
-    if(HADDR_UNDEF == (base_addr = H5FD_get_base_addr(lf)))
-        HGOTO_ERROR(H5E_FILE, H5E_CANTGET, NULL, "failed to get base address for file driver")
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F__cache_superblock_deserialize
+ *
+ * Purpose:	Loads an object from the disk.
+ *
+ * Return:	Success:	Pointer to new object
+ *		Failure:	NULL
+ *
+ * Programmer:	Quincey Koziol
+ *		koziol@hdfgroup.org
+ *		July 18 2013
+ *
+ *-------------------------------------------------------------------------
+ */
+static void *
+H5F__cache_superblock_deserialize(const void *_image, size_t len, void *_udata,
+    hbool_t H5_ATTR_UNUSED *dirty)
+{
+    H5F_super_t         *sblock = NULL; /* File's superblock */
+    H5F_superblock_cache_ud_t *udata = (H5F_superblock_cache_ud_t *)_udata; /* User data */
+    const uint8_t	*image = (const uint8_t *)_image;       /* Pointer into raw data buffer */
+    size_t              variable_size;  /* Sariable size of superblock */
+    unsigned            super_vers;     /* Superblock version */
+    uint8_t             sizeof_addr;    /* Size of offsets in the file (in bytes) */
+    uint8_t             sizeof_size;    /* Size of lengths in the file (in bytes) */
+    H5F_super_t         *ret_value;     /* Return value */
+
+    FUNC_ENTER_STATIC
+
+    /* Check arguments */
+    HDassert(image);
+    HDassert(udata);
+    HDassert(udata->f);
 
     /* Allocate space for the superblock */
     if(NULL == (sblock = H5FL_CALLOC(H5F_super_t)))
         HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, NULL, "memory allocation failed")
 
-    /* The superblock must be flushed last (and collectively in parallel) */
-    sblock->cache_info.flush_me_last = TRUE;
-#ifdef H5_HAVE_PARALLEL
-    sblock->cache_info.flush_me_collectively = TRUE;
-#endif
-
-    /* Get the DXPL plist object for DXPL ID */
-    if(NULL == (dxpl = (H5P_genplist_t *)H5I_object(dxpl_id)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, NULL, "can't get property list")
-
-    /* Read fixed-size portion of the superblock */
-    p = sbuf;
-    H5_CHECK_OVERFLOW(fixed_size, size_t, haddr_t);
-    if(H5FD_set_eoa(lf, H5FD_MEM_SUPER, (haddr_t)fixed_size) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, NULL, "set end of space allocation request failed")
-    if(H5FD_read(lf, dxpl, H5FD_MEM_SUPER, (haddr_t)0, fixed_size, p) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_READERROR, NULL, "unable to read superblock")
-
     /* Skip over signature (already checked when locating the superblock) */
-    p += H5F_SIGNATURE_LEN;
+    image += H5F_SIGNATURE_LEN;
 
     /* Superblock version */
-    super_vers = *p++;
+    super_vers = *image++;
     if(super_vers > HDF5_SUPERBLOCK_VERSION_LATEST)
         HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, NULL, "bad superblock version number")
-    if(H5P_set(c_plist, H5F_CRT_SUPER_VERS_NAME, &super_vers) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, NULL, "unable to set superblock version")
 
     /* Record the superblock version */
     sblock->super_vers = super_vers;
 
     /* Sanity check */
-    HDassert(((size_t)(p - sbuf)) == fixed_size);
+    HDassert(((size_t)(image - (const uint8_t *)_image)) == H5F_SUPERBLOCK_FIXED_SIZE);
+    HDassert(len >= H5F_SUPERBLOCK_FIXED_SIZE + 6);
+
+    /* Determine the size of addresses & size of offsets, for computing the
+     * variable-sized portion of the superblock.
+     */
+    if(super_vers < HDF5_SUPERBLOCK_VERSION_2) {
+        sizeof_addr = image[4];
+        sizeof_size = image[5];
+    } /* end if */
+    else {
+        sizeof_addr = image[0];
+        sizeof_size = image[1];
+    } /* end else */
+    if(sizeof_addr != 2 && sizeof_addr != 4 &&
+            sizeof_addr != 8 && sizeof_addr != 16 && sizeof_addr != 32)
+        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, NULL, "bad byte number in an address")
+    if(sizeof_size != 2 && sizeof_size != 4 &&
+            sizeof_size != 8 && sizeof_size != 16 && sizeof_size != 32)
+        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, NULL, "bad byte number for object size")
+    sblock->sizeof_addr = sizeof_addr;
+    sblock->sizeof_size = sizeof_size;
 
     /* Determine the size of the variable-length part of the superblock */
-    variable_size = (size_t)H5F_SUPERBLOCK_VARLEN_SIZE(super_vers, f);
+    variable_size = (size_t)H5F_SUPERBLOCK_VARLEN_SIZE(super_vers, sizeof_addr, sizeof_size);
     HDassert(variable_size > 0);
-    HDassert(fixed_size + variable_size <= sizeof(sbuf));
 
-    /* Read in variable-sized portion of superblock */
-    if(H5FD_set_eoa(lf, H5FD_MEM_SUPER, (haddr_t)(fixed_size + variable_size)) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, NULL, "set end of space allocation request failed")
-    if(H5FD_read(lf, dxpl, H5FD_MEM_SUPER, (haddr_t)fixed_size, variable_size, p) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to read superblock")
+    /* Handle metadata cache retry for variable-sized portion of the superblock */
+    if(len != (H5F_SUPERBLOCK_FIXED_SIZE + variable_size)) {
+        /* Sanity check */
+        HDassert(len == (H5F_SUPERBLOCK_FIXED_SIZE + H5F_SUPERBLOCK_MINIMAL_VARLEN_SIZE));
 
-    /* Check for older version of superblock format */
-    if(super_vers < HDF5_SUPERBLOCK_VERSION_2) {
-        uint32_t	status_flags;	    /* File status flags	   */
-        unsigned        btree_k[H5B_NUM_BTREE_ID];  /* B-tree internal node 'K' values */
-        unsigned        sym_leaf_k;         /* Symbol table leaf node's 'K' value */
-
-        /* Freespace version (hard-wired) */
-        if(HDF5_FREESPACE_VERSION != *p++)
-            HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, NULL, "bad free space version number")
-
-        /* Root group version number (hard-wired) */
-        if(HDF5_OBJECTDIR_VERSION != *p++)
-            HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, NULL, "bad object directory version number")
-
-        /* Skip over reserved byte */
-        p++;
-
-        /* Shared header version number (hard-wired) */
-        if(HDF5_SHAREDHEADER_VERSION != *p++)
-            HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, NULL, "bad shared-header format version number")
-
-        /* Size of file addresses */
-        sizeof_addr = *p++;
-        if(sizeof_addr != 2 && sizeof_addr != 4 &&
-                sizeof_addr != 8 && sizeof_addr != 16 && sizeof_addr != 32)
-            HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, NULL, "bad byte number in an address")
-        if(H5P_set(c_plist, H5F_CRT_ADDR_BYTE_NUM_NAME, &sizeof_addr) < 0)
-            HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, NULL, "unable to set byte number in an address")
-        shared->sizeof_addr = sizeof_addr;  /* Keep a local copy also */
-
-        /* Size of file sizes */
-        sizeof_size = *p++;
-        if(sizeof_size != 2 && sizeof_size != 4 &&
-                sizeof_size != 8 && sizeof_size != 16 && sizeof_size != 32)
-            HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, NULL, "bad byte number for object size")
-        if(H5P_set(c_plist, H5F_CRT_OBJ_BYTE_NUM_NAME, &sizeof_size) < 0)
-            HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, NULL, "unable to set byte number for object size")
-        shared->sizeof_size = sizeof_size;  /* Keep a local copy also */
-
-        /* Skip over reserved byte */
-        p++;
-
-        /* Various B-tree sizes */
-        UINT16DECODE(p, sym_leaf_k);
-        if(sym_leaf_k == 0)
-            HGOTO_ERROR(H5E_FILE, H5E_BADRANGE, NULL, "bad symbol table leaf node 1/2 rank")
-        if(H5P_set(c_plist, H5F_CRT_SYM_LEAF_NAME, &sym_leaf_k) < 0)
-            HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, NULL, "unable to set rank for symbol table leaf nodes")
-        sblock->sym_leaf_k = sym_leaf_k;    /* Keep a local copy also */
-
-        /* Need 'get' call to set other array values */
-        if(H5P_get(c_plist, H5F_CRT_BTREE_RANK_NAME, btree_k) < 0)
-            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "unable to get rank for btree internal nodes")
-        UINT16DECODE(p, btree_k[H5B_SNODE_ID]);
-        if(btree_k[H5B_SNODE_ID] == 0)
-            HGOTO_ERROR(H5E_FILE, H5E_BADRANGE, NULL, "bad 1/2 rank for btree internal nodes")
-        /*
-         * Delay setting the value in the property list until we've checked
-         * for the indexed storage B-tree internal 'K' value later.
-         */
-
-        /* File status flags (not really used yet) */
-        UINT32DECODE(p, status_flags);
-        HDassert(status_flags <= 255);
-        sblock->status_flags = (uint8_t)status_flags;
-        if(sblock->status_flags & ~H5F_SUPER_ALL_FLAGS)
-            HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, NULL, "bad flag value for superblock")
-
-        /*
-         * If the superblock version # is greater than 0, read in the indexed
-         * storage B-tree internal 'K' value
-         */
-        if(super_vers > HDF5_SUPERBLOCK_VERSION_DEF) {
-            UINT16DECODE(p, btree_k[H5B_CHUNK_ID]);
-            /* Reserved bytes are present only in version 1 */
-            if(super_vers == HDF5_SUPERBLOCK_VERSION_1)
-                p += 2;   /* reserved */
-        } /* end if */
-        else
-            btree_k[H5B_CHUNK_ID] = HDF5_BTREE_CHUNK_IK_DEF;
+        /* Make certain we can read the variabled-sized portion of the superblock */
+        if(H5F__set_eoa(udata->f, H5FD_MEM_SUPER, (haddr_t)(H5F_SUPERBLOCK_FIXED_SIZE + variable_size)) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, NULL, "set end of space allocation request failed")
+    } /* end if */
+    else {
+        /* Check for older version of superblock format */
+        if(super_vers < HDF5_SUPERBLOCK_VERSION_2) {
+            uint32_t    status_flags;	    /* File status flags	   */
+            unsigned    sym_leaf_k;         /* Symbol table leaf node's 'K' value */
+            unsigned    snode_btree_k;      /* B-tree symbol table internal node 'K' value */
+            unsigned    chunk_btree_k;      /* B-tree chunk internal node 'K' value */
+
+            /* Freespace version (hard-wired) */
+            if(HDF5_FREESPACE_VERSION != *image++)
+                HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, NULL, "bad free space version number")
+
+            /* Root group version number (hard-wired) */
+            if(HDF5_OBJECTDIR_VERSION != *image++)
+                HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, NULL, "bad object directory version number")
+
+            /* Skip over reserved byte */
+            image++;
+
+            /* Shared header version number (hard-wired) */
+            if(HDF5_SHAREDHEADER_VERSION != *image++)
+                HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, NULL, "bad shared-header format version number")
+
+            /* Size of file addresses */
+            sizeof_addr = *image++;
+            if(sizeof_addr != 2 && sizeof_addr != 4 &&
+                    sizeof_addr != 8 && sizeof_addr != 16 && sizeof_addr != 32)
+                HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, NULL, "bad byte number in an address")
+            sblock->sizeof_addr = sizeof_addr;
+            udata->f->shared->sizeof_addr = sizeof_addr;  /* Keep a local copy also */
+
+            /* Size of file sizes */
+            sizeof_size = *image++;
+            if(sizeof_size != 2 && sizeof_size != 4 &&
+                    sizeof_size != 8 && sizeof_size != 16 && sizeof_size != 32)
+                HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, NULL, "bad byte number for object size")
+            sblock->sizeof_size = sizeof_size;
+            udata->f->shared->sizeof_size = sizeof_size;  /* Keep a local copy also */
+
+            /* Skip over reserved byte */
+            image++;
+
+            /* Various B-tree sizes */
+            UINT16DECODE(image, sym_leaf_k);
+            if(sym_leaf_k == 0)
+                HGOTO_ERROR(H5E_FILE, H5E_BADRANGE, NULL, "bad symbol table leaf node 1/2 rank")
+            udata->sym_leaf_k = sym_leaf_k;    /* Keep a local copy also */
+
+            /* Need 'get' call to set other array values */
+            UINT16DECODE(image, snode_btree_k);
+            if(snode_btree_k == 0)
+                HGOTO_ERROR(H5E_FILE, H5E_BADRANGE, NULL, "bad 1/2 rank for btree internal nodes")
+            udata->btree_k[H5B_SNODE_ID] = snode_btree_k;
 
-        /* Set the B-tree internal node values, etc */
-        if(H5P_set(c_plist, H5F_CRT_BTREE_RANK_NAME, btree_k) < 0)
-            HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, NULL, "unable to set rank for btree internal nodes")
-        HDmemcpy(sblock->btree_k, btree_k, sizeof(unsigned) * (size_t)H5B_NUM_BTREE_ID);    /* Keep a local copy also */
+            /*
+             * Delay setting the value in the property list until we've checked
+             * for the indexed storage B-tree internal 'K' value later.
+             */
 
-        /* Remainder of "variable-sized" portion of superblock */
-        H5F_addr_decode(f, (const uint8_t **)&p, &sblock->base_addr/*out*/);
-        H5F_addr_decode(f, (const uint8_t **)&p, &sblock->ext_addr/*out*/);
-        H5F_addr_decode(f, (const uint8_t **)&p, &stored_eof/*out*/);
-        H5F_addr_decode(f, (const uint8_t **)&p, &sblock->driver_addr/*out*/);
+            /* File status flags (not really used yet) */
+            UINT32DECODE(image, status_flags);
+            HDassert(status_flags <= 255);
+            sblock->status_flags = (uint8_t)status_flags;
+            if(sblock->status_flags & ~H5F_SUPER_ALL_FLAGS)
+                HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, NULL, "bad flag value for superblock")
 
-        /* Allocate space for the root group symbol table entry */
-        HDassert(!sblock->root_ent);
-        if(NULL == (sblock->root_ent = (H5G_entry_t *)H5MM_calloc(sizeof(H5G_entry_t))))
-            HGOTO_ERROR(H5E_FILE, H5E_CANTALLOC, NULL, "can't allocate space for root group symbol table entry")
+            /*
+             * If the superblock version # is greater than 0, read in the indexed
+             * storage B-tree internal 'K' value
+             */
+            if(super_vers > HDF5_SUPERBLOCK_VERSION_DEF) {
+                UINT16DECODE(image, chunk_btree_k);
 
-        /* decode the root group symbol table entry */
-        if(H5G_ent_decode(f, (const uint8_t **)&p, sblock->root_ent) < 0)
-            HGOTO_ERROR(H5E_FILE, H5E_CANTDECODE, NULL, "can't decode root group symbol table entry")
+                /* Reserved bytes are present only in version 1 */
+                if(super_vers == HDF5_SUPERBLOCK_VERSION_1)
+                    image += 2;   /* reserved */
+            } /* end if */
+            else
+                chunk_btree_k = HDF5_BTREE_CHUNK_IK_DEF;
+            udata->btree_k[H5B_CHUNK_ID] = chunk_btree_k;
+
+            /* Remainder of "variable-sized" portion of superblock */
+            H5F_addr_decode(udata->f, (const uint8_t **)&image, &sblock->base_addr/*out*/);
+            H5F_addr_decode(udata->f, (const uint8_t **)&image, &sblock->ext_addr/*out*/);
+            H5F_addr_decode(udata->f, (const uint8_t **)&image, &udata->stored_eof/*out*/);
+            H5F_addr_decode(udata->f, (const uint8_t **)&image, &sblock->driver_addr/*out*/);
+
+            /* Allocate space for the root group symbol table entry */
+            HDassert(!sblock->root_ent);
+            if(NULL == (sblock->root_ent = (H5G_entry_t *)H5MM_calloc(sizeof(H5G_entry_t))))
+                HGOTO_ERROR(H5E_FILE, H5E_CANTALLOC, NULL, "can't allocate space for root group symbol table entry")
+
+            /* decode the root group symbol table entry */
+            if(H5G_ent_decode(udata->f, (const uint8_t **)&image, sblock->root_ent) < 0)
+                HGOTO_ERROR(H5E_FILE, H5E_CANTDECODE, NULL, "can't decode root group symbol table entry")
+
+            /* Set the root group address to the correct value */
+            sblock->root_addr = sblock->root_ent->header;
+
+            /* This step is for h5repart tool only. If user wants to change file driver
+             *  from family to sec2 while using h5repart, set the driver address to
+             *  undefined to let the library ignore the family driver information saved
+             *  in the superblock.
+             */
+            if(udata->ignore_drvrinfo && H5F_addr_defined(sblock->driver_addr)) {
+                /* Eliminate the driver info */
+                sblock->driver_addr = HADDR_UNDEF;
+                udata->drvrinfo_removed = TRUE;
+            } /* end if */
 
-        /* Set the root group address to the correct value */
-        sblock->root_addr = sblock->root_ent->header;
+            /* NOTE: Driver info block is decoded separately, later */
 
-        /*
-         * Check if superblock address is different from base address and
-         * adjust base address and "end of address" address if so.
-         */
-        if(!H5F_addr_eq(base_addr, sblock->base_addr)) {
-            /* Check if the superblock moved earlier in the file */
-            if(H5F_addr_lt(base_addr, sblock->base_addr))
-                stored_eof -= (sblock->base_addr - base_addr);
-            else
-                /* The superblock moved later in the file */
-                stored_eof += (base_addr - sblock->base_addr);
+        } /* end if */
+        else {
+            uint32_t computed_chksum;       /* Computed checksum  */
+            uint32_t read_chksum;           /* Checksum read from file  */
+
+            /* Size of file addresses */
+            sizeof_addr = *image++;
+            if(sizeof_addr != 2 && sizeof_addr != 4 &&
+                    sizeof_addr != 8 && sizeof_addr != 16 && sizeof_addr != 32)
+                HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, NULL, "bad byte number in an address")
+            sblock->sizeof_addr = sizeof_addr;
+            udata->f->shared->sizeof_addr = sizeof_addr;  /* Keep a local copy also */
+
+            /* Size of file sizes */
+            sizeof_size = *image++;
+            if(sizeof_size != 2 && sizeof_size != 4 &&
+                    sizeof_size != 8 && sizeof_size != 16 && sizeof_size != 32)
+                HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, NULL, "bad byte number for object size")
+            sblock->sizeof_size = sizeof_size;
+            udata->f->shared->sizeof_size = sizeof_size;  /* Keep a local copy also */
+
+            /* File status flags (not really used yet) */
+            sblock->status_flags = *image++;
+            if(sblock->status_flags & ~H5F_SUPER_ALL_FLAGS)
+                HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, NULL, "bad flag value for superblock")
+
+            /* Base, superblock extension, end of file & root group object header addresses */
+            H5F_addr_decode(udata->f, (const uint8_t **)&image, &sblock->base_addr/*out*/);
+            H5F_addr_decode(udata->f, (const uint8_t **)&image, &sblock->ext_addr/*out*/);
+            H5F_addr_decode(udata->f, (const uint8_t **)&image, &udata->stored_eof/*out*/);
+            H5F_addr_decode(udata->f, (const uint8_t **)&image, &sblock->root_addr/*out*/);
+
+            /* Compute checksum for superblock */
+            computed_chksum = H5_checksum_metadata(_image, (size_t)(image - (const uint8_t *)_image), 0);
+
+            /* Decode checksum */
+            UINT32DECODE(image, read_chksum);
+
+            /* Verify correct checksum */
+            if(read_chksum != computed_chksum)
+                HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "bad checksum on driver information block")
+
+            /* The Driver Information Block may not appear with the version
+             * 2 super block.  Thus we set the driver_addr field of the in 
+             * core representation of the super block HADDR_UNDEF to prevent 
+             * any attempt to load the Driver Information Block.
+             */
+            sblock->driver_addr = HADDR_UNDEF;
+        } /* end else */
+    } /* end else */
 
-            /* Adjust base address for offsets of the HDF5 data in the file */
-            sblock->base_addr = base_addr;
+    /* Sanity check */
+    HDassert((size_t)(image - (const uint8_t *)_image) <= len);
 
-            /* Set the base address for the file in the VFD now */
-            if(H5FD_set_base_addr(lf, sblock->base_addr) < 0)
-                HGOTO_ERROR(H5E_FILE, H5E_CANTSET, NULL, "failed to set base address for file driver")
+    /* Set return value */
+    ret_value = sblock;
 
-            /* Indicate that the superblock should be marked dirty */
-            *dirtied = TRUE;
-        } /* end if */
+done:
+    /* Release the [possibly partially initialized] superblock on error */
+    if(!ret_value && sblock)
+        if(H5F__super_free(sblock) < 0)
+            HDONE_ERROR(H5E_FILE, H5E_CANTFREE, NULL, "unable to destroy superblock data")
 
-        /* This step is for h5repart tool only. If user wants to change file driver
-         *  from family to sec2 while using h5repart, set the driver address to
-         *  undefined to let the library ignore the family driver information saved
-         *  in the superblock.
-         */
-        if(H5F_HAS_FEATURE(f, H5FD_FEAT_IGNORE_DRVRINFO)) {
-            /* Eliminate the driver info */
-            sblock->driver_addr = HADDR_UNDEF;
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5F__cache_superblock_deserialize() */
 
-            /* Indicate that the superblock should be marked dirty */
-            *dirtied = TRUE;
-        } /* end if */
+
+/*-------------------------------------------------------------------------
+ * Function:    H5F__cache_superblock_image_len
+ *
+ * Purpose:     Compute the size of the data structure on disk.
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Quincey Koziol
+ *              koziol@hdfgroup.org
+ *              July 19, 2013
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5F__cache_superblock_image_len(const void *_thing, size_t *image_len, hbool_t *compressed_ptr, size_t H5_ATTR_UNUSED *compressed_image_len_ptr)
+{
+    const H5F_super_t *sblock = (const H5F_super_t *)_thing;    /* Pointer to the object */
 
-        /* Decode the optional driver information block */
-        if(H5F_addr_defined(sblock->driver_addr)) {
-            uint8_t dbuf[H5F_MAX_DRVINFOBLOCK_SIZE];     /* Buffer for driver info block */
-            char drv_name[9];       /* Name of driver */
-            unsigned drv_vers;      /* Version of driver info block */
-            size_t drv_variable_size; /* Size of variable-length portion of driver info block, in bytes */
-
-            /* Read in fixed-sized portion of driver info block */
-            p = dbuf;
-            if(H5FD_set_eoa(lf, H5FD_MEM_SUPER, sblock->driver_addr + H5F_DRVINFOBLOCK_HDR_SIZE) < 0)
-                HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, NULL, "set end of space allocation request failed")
-            if(H5FD_read(lf, dxpl, H5FD_MEM_SUPER, sblock->driver_addr, (size_t)H5F_DRVINFOBLOCK_HDR_SIZE, p) < 0)
-                HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to read driver information block")
-
-            /* Version number */
-            drv_vers = *p++;
-            if(drv_vers != HDF5_DRIVERINFO_VERSION_0)
-                HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "bad driver information block version number")
-
-            p += 3; /* reserved bytes */
-
-            /* Driver info size */
-            UINT32DECODE(p, drv_variable_size);
-
-            /* Sanity check */
-            HDassert(H5F_DRVINFOBLOCK_HDR_SIZE + drv_variable_size <= sizeof(dbuf));
-
-            /* Driver name and/or version */
-            HDstrncpy(drv_name, (const char *)p, (size_t)8);
-            drv_name[8] = '\0';
-            p += 8; /* advance past name/version */
-
-            /* Read in variable-sized portion of driver info block */
-            if(H5FD_set_eoa(lf, H5FD_MEM_SUPER, sblock->driver_addr + H5F_DRVINFOBLOCK_HDR_SIZE + drv_variable_size) < 0)
-                HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, NULL, "set end of space allocation request failed")
-            if(H5FD_read(lf, dxpl, H5FD_MEM_SUPER, sblock->driver_addr + H5F_DRVINFOBLOCK_HDR_SIZE, drv_variable_size, p) < 0)
-                HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to read file driver information")
-
-            /* Decode driver information */
-            if(H5FD_sb_load(lf, drv_name, p) < 0)
-                HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to decode driver information")
-        } /* end if */
-    } /* end if */
-    else {
-        uint32_t computed_chksum;       /* Computed checksum  */
-        uint32_t read_chksum;           /* Checksum read from file  */
-
-        /* Size of file addresses */
-        sizeof_addr = *p++;
-        if(sizeof_addr != 2 && sizeof_addr != 4 &&
-                sizeof_addr != 8 && sizeof_addr != 16 && sizeof_addr != 32)
-            HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, NULL, "bad byte number in an address")
-        if(H5P_set(c_plist, H5F_CRT_ADDR_BYTE_NUM_NAME, &sizeof_addr) < 0)
-            HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, NULL, "unable to set byte number in an address")
-        shared->sizeof_addr = sizeof_addr;  /* Keep a local copy also */
-
-        /* Size of file sizes */
-        sizeof_size = *p++;
-        if(sizeof_size != 2 && sizeof_size != 4 &&
-                sizeof_size != 8 && sizeof_size != 16 && sizeof_size != 32)
-            HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, NULL, "bad byte number for object size")
-        if(H5P_set(c_plist, H5F_CRT_OBJ_BYTE_NUM_NAME, &sizeof_size) < 0)
-            HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, NULL, "unable to set byte number for object size")
-        shared->sizeof_size = sizeof_size;  /* Keep a local copy also */
-
-        /* File status flags (not really used yet) */
-        sblock->status_flags = *p++;
-        if(sblock->status_flags & ~H5F_SUPER_ALL_FLAGS)
-            HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, NULL, "bad flag value for superblock")
-
-        /* Base, superblock extension, end of file & root group object header addresses */
-        H5F_addr_decode(f, (const uint8_t **)&p, &sblock->base_addr/*out*/);
-        H5F_addr_decode(f, (const uint8_t **)&p, &sblock->ext_addr/*out*/);
-        H5F_addr_decode(f, (const uint8_t **)&p, &stored_eof/*out*/);
-        H5F_addr_decode(f, (const uint8_t **)&p, &sblock->root_addr/*out*/);
-
-        /* Compute checksum for superblock */
-        computed_chksum = H5_checksum_metadata(sbuf, (size_t)(p - sbuf), 0);
-
-        /* Decode checksum */
-        UINT32DECODE(p, read_chksum);
-
-        /* Verify correct checksum */
-        if(read_chksum != computed_chksum)
-            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "bad checksum on driver information block")
+    FUNC_ENTER_STATIC_NOERR
 
-        /*
-         * Check if superblock address is different from base address and
-         * adjust base address and "end of address" address if so.
-         */
-        if(!H5F_addr_eq(base_addr, sblock->base_addr)) {
-            /* Check if the superblock moved earlier in the file */
-            if(H5F_addr_lt(base_addr, sblock->base_addr))
-                stored_eof -= (sblock->base_addr - base_addr);
-            else
-                /* The superblock moved later in the file */
-                stored_eof += (base_addr - sblock->base_addr);
+    /* Check arguments */
+    HDassert(sblock);
+    HDassert(sblock->cache_info.magic == H5C__H5C_CACHE_ENTRY_T_MAGIC);
+    HDassert(sblock->cache_info.type == H5AC_SUPERBLOCK);
+    HDassert(image_len);
+    HDassert(compressed_ptr);
 
-            /* Adjust base address for offsets of the HDF5 data in the file */
-            sblock->base_addr = base_addr;
+    /* Set the image length size */
+    *image_len = (size_t)H5F_SUPERBLOCK_SIZE(sblock);
 
-            /* Set the base address for the file in the VFD now */
-            if(H5FD_set_base_addr(lf, sblock->base_addr) < 0)
-                HGOTO_ERROR(H5E_FILE, H5E_CANTSET, NULL, "failed to set base address for file driver")
+    /* Set *compressed_ptr to FALSE unconditionally */
+    *compressed_ptr;
 
-            /* Indicate that the superblock should be marked dirty */
-            *dirtied = TRUE;
-        } /* end if */
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5F__cache_superblock_image_len() */
 
-        /* Get the B-tree internal node values, etc */
-        if(H5P_get(c_plist, H5F_CRT_BTREE_RANK_NAME, sblock->btree_k) < 0)
-            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "unable to get rank for btree internal nodes")
-        if(H5P_get(c_plist, H5F_CRT_SYM_LEAF_NAME, &sblock->sym_leaf_k) < 0)
-            HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, NULL, "unable to get rank for btree internal nodes")
-    } /* end else */
+
+/*-------------------------------------------------------------------------
+ * Function:    H5FS__cache_hdf_pre_serialize
+ *
+ * Purpose:	The current use of this function is a cludge to repair an 
+ *		oversight in the conversion of the superblock code to use the 
+ *		version 3 cache.  
+ *
+ *		In the V2 metadata cache callbacks, the superblock dirver info 
+ *     		message was updated in the flush routine.  Note that this 
+ *		operation only applies to version 2 or later superblocks.
+ *
+ *     		Somehow, this functionality was lost in the conversion to use 
+ *     		the V3 cache, causing failures with the multi file driver 
+ *     		(and possibly the family file driver as well).
+ *
+ *     		Performing this operation is impossible in the current 
+ *		serialize routine, as the dxpl_id is not available.  While 
+ *		I am pretty sure that this is not the correct place for this 
+ *		functionality, as I can see it causing problems with both 
+ *		journaling and possibly parallel HDF5 as well, I am placing 
+ *		code for the necessary update in the pre_serialize call for 
+ *		now for testing purposes.  We will almost certainly want to 
+ *		change this.
+ *
+ * Return:      Success:        SUCCEED
+ *              Failure:        FAIL
+ *
+ * Programmer:  John Mainzer
+ *              10/82/14
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5F__cache_superblock_pre_serialize(const H5F_t *f, hid_t dxpl_id, 
+    void *_thing, haddr_t H5_ATTR_UNUSED addr, size_t H5_ATTR_UNUSED len, 
+    size_t H5_ATTR_UNUSED compressed_len, haddr_t H5_ATTR_UNUSED *new_addr, 
+    size_t H5_ATTR_UNUSED *new_len, size_t H5_ATTR_UNUSED *new_compressed_len, 
+    unsigned H5_ATTR_UNUSED *flags)
+{
+    H5F_super_t *sblock = (H5F_super_t *)_thing; /* Pointer to the super block */
+    herr_t ret_value = SUCCEED; /* Return value */
 
-    /*
-     * The user-defined data is the area of the file before the base
-     * address.
-     */
-    if(H5P_set(c_plist, H5F_CRT_USER_BLOCK_NAME, &sblock->base_addr) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, NULL, "unable to set userblock size")
+    FUNC_ENTER_NOAPI_NOINIT
 
-    /*
-     * Make sure that the data is not truncated. One case where this is
-     * possible is if the first file of a family of files was opened
-     * individually.
-     */
-    if(HADDR_UNDEF == (eof = H5FD_get_eof(lf, H5FD_MEM_DEFAULT)))
-        HGOTO_ERROR(H5E_FILE, H5E_CANTGET, NULL, "unable to determine file size")
-
-    /* (Account for the stored EOF being absolute offset -QAK) */
-    if((eof + sblock->base_addr) < stored_eof)
-        HGOTO_ERROR(H5E_FILE, H5E_TRUNCATED, NULL,
-                    "truncated file: eof = %llu, sblock->base_addr = %llu, stored_eof = %llu",
-                    (unsigned long long)eof, (unsigned long long)sblock->base_addr, (unsigned long long)stored_eof)
-
-    /*
-     * Tell the file driver how much address space has already been
-     * allocated so that it knows how to allocate additional memory.
-     */
-    /* (Account for the stored EOA being absolute offset -NAF) */
-    if(H5FD_set_eoa(lf, H5FD_MEM_SUPER, stored_eof - sblock->base_addr) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to set end-of-address marker for file")
-
-    /* Read the file's superblock extension, if there is one. */
-    if(H5F_addr_defined(sblock->ext_addr)) {
-        H5O_loc_t ext_loc;      /* "Object location" for superblock extension */
-        H5O_btreek_t btreek;    /* v1 B-tree 'K' value message from superblock extension */
-        H5O_drvinfo_t drvinfo;  /* Driver info message from superblock extension */
-	size_t u; 		/* Local index variable */
-        htri_t status;          /* Status for message existing */
-
-        /* Sanity check - superblock extension should only be defined for
-         *      superblock version >= 2.
+    /* Sanity check */
+    HDassert(f);
+    HDassert(sblock);
+    HDassert(sblock->cache_info.magic == H5C__H5C_CACHE_ENTRY_T_MAGIC);
+    HDassert(sblock->cache_info.type == H5AC_SUPERBLOCK);
+    HDassert(flags);
+
+    if(sblock->super_vers >= HDF5_SUPERBLOCK_VERSION_2) {
+        /* WARNING: This code almost certainly doesn't belong here.  Must
+         *          discuss with Quincey where to put it.  Note issues
+         *          for journaling and possibly parallel.
+         *
+         *                                            -- JRM
          */
-        HDassert(super_vers >= HDF5_SUPERBLOCK_VERSION_2);
-
-        /* Check for superblock extension being located "outside" the stored
-         *      'eoa' value, which can occur with the split/multi VFD.
+        /* Update the driver information message in the superblock extension
+         * if appropriate.
          */
-        if(H5F_addr_gt(sblock->ext_addr, stored_eof)) {
-            /* Set the 'eoa' for the object header memory type large enough
-             *  to give some room for a reasonably sized superblock extension.
-             *  (This is _rather_ a kludge -QAK)
-             */
-            if(H5FD_set_eoa(lf, H5FD_MEM_OHDR, (haddr_t)(sblock->ext_addr + 1024)) < 0)
-                HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to set end-of-address marker for file")
-        } /* end if */
+        if(H5F_addr_defined(sblock->ext_addr)) {
+            size_t     driver_size;    /* Size of driver info block (bytes)*/
+            H5O_loc_t  ext_loc;        /* "Object location" for superblock extension */
 
-        /* Open the superblock extension */
-	if(H5F_super_ext_open(f, sblock->ext_addr, &ext_loc) < 0)
-            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENOBJ, NULL, "unable to open file's superblock extension")
+            HDassert(sblock->super_vers >= HDF5_SUPERBLOCK_VERSION_2);
+
+            /* Open the superblock extension's object header */
+            if(H5F_super_ext_open((H5F_t *)f, sblock->ext_addr, &ext_loc) < 0)
+                HGOTO_ERROR(H5E_FILE, H5E_CANTOPENOBJ, FAIL, "unable to open file's superblock extension")
 
-        /* Check for the extension having a 'driver info' message */
-        if((status = H5O_msg_exists(&ext_loc, H5O_DRVINFO_ID, dxpl_id)) < 0)
-            HGOTO_ERROR(H5E_FILE, H5E_CANTGET, NULL, "unable to read object header")
-        if(status) {
             /* Check for ignoring the driver info for this file */
-            if(H5F_HAS_FEATURE(f, H5FD_FEAT_IGNORE_DRVRINFO)) {
-                /* Indicate that the superblock should be marked dirty */
-                *dirtied = TRUE;
-            } /* end if */
-            else {
-                /* Retrieve the 'driver info' structure */
-                if(NULL == H5O_msg_read(&ext_loc, H5O_DRVINFO_ID, &drvinfo, dxpl_id))
-                    HGOTO_ERROR(H5E_FILE, H5E_CANTGET, NULL, "driver info message not present")
-
-                /* Decode driver information */
-                if(H5FD_sb_load(lf, drvinfo.name, drvinfo.buf) < 0)
-                    HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to decode driver information")
-
-                /* Reset driver info message */
-                H5O_msg_reset(H5O_DRVINFO_ID, &drvinfo);
-            } /* end else */
-        } /* end if */
+            if(!H5F_HAS_FEATURE(f, H5FD_FEAT_IGNORE_DRVRINFO)) {
+                /* Check for driver info message */
+                H5_CHECKED_ASSIGN(driver_size, size_t, H5FD_sb_size(f->shared->lf), hsize_t);
+                if(driver_size > 0) {
+                    H5O_drvinfo_t drvinfo;      /* Driver info */
+                    uint8_t dbuf[H5F_MAX_DRVINFOBLOCK_SIZE];  /* Driver info block encoding buffer */
 
-        /* Read in the shared OH message information if there is any */
-        if(H5SM_get_info(&ext_loc, c_plist, dxpl_id) < 0)
-            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, NULL, "unable to read SOHM table information")
-
-        /* Check for the extension having a 'v1 B-tree "K"' message */
-        if((status = H5O_msg_exists(&ext_loc, H5O_BTREEK_ID, dxpl_id)) < 0)
-            HGOTO_ERROR(H5E_FILE, H5E_CANTGET, NULL, "unable to read object header")
-        if(status) {
-            /* Retrieve the 'v1 B-tree "K"' structure */
-            if(NULL == H5O_msg_read(&ext_loc, H5O_BTREEK_ID, &btreek, dxpl_id))
-                HGOTO_ERROR(H5E_FILE, H5E_CANTGET, NULL, "v1 B-tree 'K' info message not present")
-
-            /* Set non-default v1 B-tree 'K' value info from file */
-            sblock->btree_k[H5B_CHUNK_ID] = btreek.btree_k[H5B_CHUNK_ID];
-            sblock->btree_k[H5B_SNODE_ID] = btreek.btree_k[H5B_SNODE_ID];
-            sblock->sym_leaf_k = btreek.sym_leaf_k;
-
-            /* Set non-default v1 B-tree 'K' values in the property list */
-            if(H5P_set(c_plist, H5F_CRT_BTREE_RANK_NAME, btreek.btree_k) < 0)
-                HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, NULL, "unable to set rank for btree internal nodes")
-            if(H5P_set(c_plist, H5F_CRT_SYM_LEAF_NAME, &btreek.sym_leaf_k) < 0)
-                HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, NULL, "unable to set rank for symbol table leaf nodes")
-        } /* end if */
+                    /* Sanity check */
+                    HDassert(driver_size <= H5F_MAX_DRVINFOBLOCK_SIZE);
 
-        /* Check for the extension having a 'free-space manager info' message */
-        if((status = H5O_msg_exists(&ext_loc, H5O_FSINFO_ID, dxpl_id)) < 0)
-            HGOTO_ERROR(H5E_FILE, H5E_CANTGET, NULL, "unable to check object header")
-        if(status) {
-            H5O_fsinfo_t fsinfo;    /* Free-space manager info message from superblock extension */
-
-            /* Retrieve the 'free-space manager info' structure */
-	    if(NULL == H5O_msg_read(&ext_loc, H5O_FSINFO_ID, &fsinfo, dxpl_id))
-                HGOTO_ERROR(H5E_OHDR, H5E_CANTGET, NULL, "unable to get free-space manager info message")
-
-	    if(shared->fs_strategy != fsinfo.strategy) {
-		shared->fs_strategy = fsinfo.strategy;
-
-		/* Set non-default strategy in the property list */
-		if(H5P_set(c_plist, H5F_CRT_FILE_SPACE_STRATEGY_NAME, &fsinfo.strategy) < 0)
-		    HGOTO_ERROR(H5E_FILE, H5E_CANTSET, NULL, "unable to set file space strategy")
-	    } /* end if */
-	    if(shared->fs_threshold != fsinfo.threshold) {
-		shared->fs_threshold = fsinfo.threshold;
-
-		/* Set non-default threshold in the property list */
-		if(H5P_set(c_plist, H5F_CRT_FREE_SPACE_THRESHOLD_NAME, &fsinfo.threshold) < 0)
-		    HGOTO_ERROR(H5E_FILE, H5E_CANTSET, NULL, "unable to set file space strategy")
-	    } /* end if */
-
-	    /* set free-space manager addresses */
-	    shared->fs_addr[0] = HADDR_UNDEF;
-	    for(u = 1; u < NELMTS(f->shared->fs_addr); u++)
-		shared->fs_addr[u] = fsinfo.fs_addr[u-1];
-        } /* end if */
+                    /* Encode driver-specific data */
+                    if(H5FD_sb_encode(f->shared->lf, drvinfo.name, dbuf) < 0)
+                        HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "unable to encode driver information")
 
-        /* Close superblock extension */
-        if(H5F_super_ext_close(f, &ext_loc, dxpl_id, FALSE) < 0)
-	    HGOTO_ERROR(H5E_FILE, H5E_CANTRELEASE, NULL, "unable to close file's superblock extension")
-    } /* end if */
+                    /* Write driver info information to the superblock extension */
+                    drvinfo.len = driver_size;
+                    drvinfo.buf = dbuf;
+                    if(H5O_msg_write(&ext_loc, H5O_DRVINFO_ID, H5O_MSG_FLAG_DONTSHARE, H5O_UPDATE_TIME, &drvinfo, dxpl_id) < 0)
+                        HGOTO_ERROR(H5E_FILE, H5E_WRITEERROR, FAIL, "unable to update driver info header message")
+                } /* end if */
+            } /* end if */
 
-    /* Set return value */
-    ret_value = sblock;
+            /* Close the superblock extension object header */
+            if(H5F_super_ext_close((H5F_t *)f, &ext_loc, dxpl_id, FALSE) < 0)
+                HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEOBJ, FAIL, "unable to close file's superblock extension")
+        } /* end if */
+    } /* end if */
 
 done:
-    /* Release the [possibly partially initialized] superblock on errors */
-    if(!ret_value && sblock)
-        if(H5F__super_free(sblock) < 0)
-            HDONE_ERROR(H5E_FILE, H5E_CANTFREE, NULL, "unable to destroy superblock data")
-
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5F_sblock_load() */
+} /* end H5FS_cache_superblock_pre_serialize() */
 
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_sblock_flush
+ * Function:	H5F__cache_superblock_serialize
  *
- * Purpose:     Flushes the superblock.
+ * Purpose:	Flushes a dirty object to disk.
  *
- * Return:      Success:        SUCCEED
- *              Failure:        NULL
+ * Return:	Non-negative on success/Negative on failure
  *
- * Programmer:  Mike McGreevy
- *              mamcgree@hdfgroup.org
- *              April 8, 2009
+ * Programmer:	Quincey Koziol
+ *		koziol@hdfgroup.org
+ *		July 19 2013
  *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F_sblock_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t H5_ATTR_UNUSED addr,
-    H5F_super_t *sblock)
+H5F__cache_superblock_serialize(const H5F_t *f, void *_image, size_t H5_ATTR_UNUSED len,
+    void *_thing)
 {
-    herr_t          ret_value = SUCCEED;
+    H5F_super_t *sblock = (H5F_super_t *)_thing;      /* Pointer to the object */
+    uint8_t *image = (uint8_t *)_image;         /* Pointer into raw data buffer */
+    haddr_t rel_eof;            /* Relative EOF for file */
+    herr_t ret_value = SUCCEED; /* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT
+    FUNC_ENTER_STATIC
 
-    /* check arguments */
+    /* Sanity check */
     HDassert(f);
-    HDassert(H5F_addr_eq(addr, 0));
+    HDassert(image);
     HDassert(sblock);
-    
+
     /* Assert that the superblock is marked as being flushed last (and 
        collectively in parallel) */
     /* (We'll rely on the cache to make sure it actually *is* flushed
@@ -656,301 +619,403 @@ H5F_sblock_flush(H5F_t *f, hid_t dxpl_id, hbool_t destroy, haddr_t H5_ATTR_UNUSE
     HDassert(sblock->cache_info.flush_me_collectively);
 #endif
 
-    if(sblock->cache_info.is_dirty) {
-        H5P_genplist_t *dxpl;               /* DXPL object */
-        uint8_t         buf[H5F_MAX_SUPERBLOCK_SIZE + H5F_MAX_DRVINFOBLOCK_SIZE];  /* Superblock & driver info blockencoding buffer */
-        uint8_t        *p;                  /* Ptr into encoding buffer */
-        haddr_t         rel_eof;            /* Relative EOF for file */
-        size_t          superblock_size;    /* Size of superblock, in bytes */
-        size_t          driver_size;        /* Size of driver info block (bytes)*/
+    /* Encode the common portion of the file superblock for all versions */
+    HDmemcpy(image, H5F_SIGNATURE, (size_t)H5F_SIGNATURE_LEN);
+    image += H5F_SIGNATURE_LEN;
+    *image++ = (uint8_t)sblock->super_vers;
 
-        /* Encode the common portion of the file superblock for all versions */
-        p = buf;
-        HDmemcpy(p, H5F_SIGNATURE, (size_t)H5F_SIGNATURE_LEN);
-        p += H5F_SIGNATURE_LEN;
-        *p++ = (uint8_t)sblock->super_vers;
+    /* Check for older version of superblock format */
+    if(sblock->super_vers < HDF5_SUPERBLOCK_VERSION_2) {
+        *image++ = (uint8_t)HDF5_FREESPACE_VERSION;     /* (hard-wired) */
+        *image++ = (uint8_t)HDF5_OBJECTDIR_VERSION;     /* (hard-wired) */
+        *image++ = 0;   /* reserved*/
 
-        /* Check for older version of superblock format */
-        if(sblock->super_vers < HDF5_SUPERBLOCK_VERSION_2) {
-            *p++ = (uint8_t)HDF5_FREESPACE_VERSION;     /* (hard-wired) */
-            *p++ = (uint8_t)HDF5_OBJECTDIR_VERSION;     /* (hard-wired) */
-            *p++ = 0;   /* reserved*/
+        *image++ = (uint8_t)HDF5_SHAREDHEADER_VERSION;  /* (hard-wired) */
+        *image++ = sblock->sizeof_addr;
+        *image++ = sblock->sizeof_size;
+        *image++ = 0;   /* reserved */
 
-            *p++ = (uint8_t)HDF5_SHAREDHEADER_VERSION;  /* (hard-wired) */
-            *p++ = (uint8_t)H5F_SIZEOF_ADDR(f);
-            *p++ = (uint8_t)H5F_SIZEOF_SIZE(f);
-            *p++ = 0;   /* reserved */
+        UINT16ENCODE(image, sblock->sym_leaf_k);
+        UINT16ENCODE(image, sblock->btree_k[H5B_SNODE_ID]);
+        UINT32ENCODE(image, (uint32_t)sblock->status_flags);
 
-            UINT16ENCODE(p, sblock->sym_leaf_k);
-            UINT16ENCODE(p, sblock->btree_k[H5B_SNODE_ID]);
-            UINT32ENCODE(p, (uint32_t)sblock->status_flags);
+        /*
+         * Versions of the superblock >0 have the indexed storage B-tree
+         * internal 'K' value stored
+         */
+        if(sblock->super_vers > HDF5_SUPERBLOCK_VERSION_DEF) {
+            UINT16ENCODE(image, sblock->btree_k[H5B_CHUNK_ID]);
+            *image++ = 0;   /*reserved */
+            *image++ = 0;   /*reserved */
+        } /* end if */
 
-            /*
-             * Versions of the superblock >0 have the indexed storage B-tree
-             * internal 'K' value stored
-             */
-            if(sblock->super_vers > HDF5_SUPERBLOCK_VERSION_DEF) {
-                UINT16ENCODE(p, sblock->btree_k[H5B_CHUNK_ID]);
-                *p++ = 0;   /*reserved */
-                *p++ = 0;   /*reserved */
-            } /* end if */
+        /* Encode the base address */
+        H5F_addr_encode(f, &image, sblock->base_addr);
 
-            /* Encode the base address */
-            H5F_addr_encode(f, &p, sblock->base_addr);
-
-            /* Encode the address of global free-space index */
-            H5F_addr_encode(f, &p, sblock->ext_addr);
-
-            /* Encode the end-of-file address. Note that at this point in time,
-             * the EOF value itself may not be reflective of the file's size, as
-             * we will eventually truncate the file to match the EOA value. As
-             * such, use the EOA value in its place, knowing that the current EOF
-             * value will ultimately match it. */
-            if ((rel_eof = H5FD_get_eoa(f->shared->lf, H5FD_MEM_SUPER)) == HADDR_UNDEF)
-                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "driver get_eoa request failed")
-            H5F_addr_encode(f, &p, (rel_eof + sblock->base_addr));
-
-            /* Encode the driver informaton block address */
-            H5F_addr_encode(f, &p, sblock->driver_addr);
-
-            /* Encode the root group object entry, including the cached stab info */
-            if(H5G_ent_encode(f, &p, sblock->root_ent) < 0)
-                HGOTO_ERROR(H5E_FILE, H5E_CANTENCODE, FAIL, "can't encode root group symbol table entry")
-
-            /* Encode the driver information block. */
-            H5_CHECKED_ASSIGN(driver_size, size_t, H5FD_sb_size(f->shared->lf), hsize_t);
-
-            /* Checking whether driver block address is defined here is to handle backward
-             * compatibility.  If the file was created with v1.6 library or earlier and no
-             * driver info block was written in the superblock, we don't write it either even
-             * though there's some driver info.  Otherwise, the driver block extended will
-             * overwrite the (meta)data right after the superblock. This situation happens to
-             * the family driver particularly.  SLU - 2009/3/24
-             */
-            if(driver_size > 0 && H5F_addr_defined(sblock->driver_addr)) {
-                char driver_name[9];    /* Name of driver, for driver info block */
-                uint8_t *dbuf = p;      /* Pointer to beginning of driver info */
+        /* Encode the address of global free-space index */
+        H5F_addr_encode(f, &image, sblock->ext_addr);
 
-                /* Encode the driver information block */
-                *p++ = HDF5_DRIVERINFO_VERSION_0; /* Version */
-                *p++ = 0; /* reserved */
-                *p++ = 0; /* reserved */
-                *p++ = 0; /* reserved */
+        /* Encode the end-of-file address. Note that at this point in time,
+         * the EOF value itself may not be reflective of the file's size, as
+         * we will eventually truncate the file to match the EOA value. As
+         * such, use the EOA value in its place, knowing that the current EOF
+         * value will ultimately match it. */
+        if ((rel_eof = H5FD_get_eoa(f->shared->lf, H5FD_MEM_SUPER)) == HADDR_UNDEF)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "driver get_eoa request failed")
+        H5F_addr_encode(f, &image, (rel_eof + sblock->base_addr));
 
-                /* Driver info size, excluding header */
-                UINT32ENCODE(p, driver_size);
+        /* Encode the driver informaton block address */
+        H5F_addr_encode(f, &image, sblock->driver_addr);
 
-                /* Encode driver-specific data */
-                if(H5FD_sb_encode(f->shared->lf, driver_name, dbuf + H5F_DRVINFOBLOCK_HDR_SIZE) < 0)
-                    HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "unable to encode driver information")
+        /* Encode the root group object entry, including the cached stab info */
+        if(H5G_ent_encode(f, &image, sblock->root_ent) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTENCODE, FAIL, "can't encode root group symbol table entry")
 
-                /* Store driver name (set in 'H5FD_sb_encode' call above) */
-                HDmemcpy(p, driver_name, (size_t)8);
+        /* NOTE: Driver info block is handled separately */
 
-                /* Advance buffer pointer past name & variable-sized portion of driver info */
-                /* (for later use in computing the superblock size) */
-                p += 8 + driver_size;
-            } /* end if */
-        } /* end if */
-        else {
-            uint32_t        chksum;                 /* Checksum temporary variable      */
-            H5O_loc_t       *root_oloc;             /* Pointer to root group's object location */
+    } /* end if */
+    else { /* sblock->super_vers >= HDF5_SUPERBLOCK_VERSION_2 */
+        uint32_t        chksum;                 /* Checksum temporary variable      */
+        H5O_loc_t       *root_oloc;             /* Pointer to root group's object location */
 
-            /* Size of file addresses & offsets, and status flags */
-            *p++ = (uint8_t)H5F_SIZEOF_ADDR(f);
-            *p++ = (uint8_t)H5F_SIZEOF_SIZE(f);
-            *p++ = sblock->status_flags;
+        /* Size of file addresses & offsets, and status flags */
+        *image++ = sblock->sizeof_addr;
+        *image++ = sblock->sizeof_size;
+        *image++ = sblock->status_flags;
 
-            /* Encode the base address */
-            H5F_addr_encode(f, &p, sblock->base_addr);
+        /* Encode the base address */
+        H5F_addr_encode(f, &image, sblock->base_addr);
 
-            /* Encode the address of the superblock extension */
-            H5F_addr_encode(f, &p, sblock->ext_addr);
+        /* Encode the address of the superblock extension */
+        H5F_addr_encode(f, &image, sblock->ext_addr);
 
-            /* At this point in time, the EOF value itself may
-             * not be reflective of the file's size, since we'll eventually
-             * truncate it to match the EOA value. As such, use the EOA value
-             * in its place, knowing that the current EOF value will
-             * ultimately match it. */
-            if ((rel_eof = H5FD_get_eoa(f->shared->lf, H5FD_MEM_SUPER)) == HADDR_UNDEF)
-                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "driver get_eoa request failed")
-            H5F_addr_encode(f, &p, (rel_eof + sblock->base_addr));
+        /* At this point in time, the EOF value itself may
+         * not be reflective of the file's size, since we'll eventually
+         * truncate it to match the EOA value. As such, use the EOA value
+         * in its place, knowing that the current EOF value will
+         * ultimately match it. */
+        if ((rel_eof = H5FD_get_eoa(f->shared->lf, H5FD_MEM_SUPER)) == HADDR_UNDEF)
+            HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, FAIL, "driver get_eoa request failed")
+        H5F_addr_encode(f, &image, (rel_eof + sblock->base_addr));
 
-            /* Retrieve information for root group */
-            if(NULL == (root_oloc = H5G_oloc(f->shared->root_grp)))
-                HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "unable to retrieve root group information")
+        /* Retrieve information for root group */
+        if(NULL == (root_oloc = H5G_oloc(f->shared->root_grp)))
+            HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "unable to retrieve root group information")
 
-            /* Encode address of root group's object header */
-            H5F_addr_encode(f, &p, root_oloc->addr);
+        /* Encode address of root group's object header */
+        H5F_addr_encode(f, &image, root_oloc->addr);
 
-            /* Compute superblock checksum */
-            chksum = H5_checksum_metadata(buf, ((size_t)H5F_SUPERBLOCK_SIZE(sblock->super_vers, f) - H5F_SIZEOF_CHKSUM), 0);
+        /* Compute superblock checksum */
+        chksum = H5_checksum_metadata(_image, ((size_t)H5F_SUPERBLOCK_SIZE(sblock) - H5F_SIZEOF_CHKSUM), 0);
 
-            /* Superblock checksum */
-            UINT32ENCODE(p, chksum);
+        /* Superblock checksum */
+        UINT32ENCODE(image, chksum);
 
-            /* Sanity check */
-            HDassert((size_t)(p - buf) == (size_t)H5F_SUPERBLOCK_SIZE(sblock->super_vers, f));
-        } /* end else */
+        /* Sanity check */
+        HDassert((size_t)(image - (uint8_t *)_image) == (size_t)H5F_SUPERBLOCK_SIZE(sblock));
+    } /* end else */
 
-        /* Retrieve the total size of the superblock info */
-        H5_CHECKED_ASSIGN(superblock_size, size_t, (p - buf), ptrdiff_t);
+    /* Sanity check */
+    HDassert((size_t)(image - (uint8_t *)_image) <= len);
 
-        /* Double check we didn't overrun the block (unlikely) */
-        HDassert(superblock_size <= sizeof(buf));
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5F__cache_superblock_serialize() */
 
-        /* Get the DXPL plist object for DXPL ID */
-        if(NULL == (dxpl = (H5P_genplist_t *)H5I_object(dxpl_id)))
-            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F__cache_superblock_free_icr
+ *
+ * Purpose:	Destroy/release an "in core representation" of a data
+ *              structure
+ *
+ * Note:	The metadata cache sets the object's cache_info.magic to
+ *		H5C__H5C_CACHE_ENTRY_T_BAD_MAGIC before calling a free_icr
+ *		callback (checked in assert).
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Quincey Koziol
+ *              koziol@hdfgroup.org
+ *              July 20, 2013
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5F__cache_superblock_free_icr(void *_thing)
+{
+    H5F_super_t *sblock = (H5F_super_t *)_thing;        /* Pointer to the object */
+    herr_t ret_value = SUCCEED;         /* Return value */
 
-        /* Write superblock */
-        /* (always at relative address 0) */
-        if(H5FD_write(f->shared->lf, dxpl, H5FD_MEM_SUPER, (haddr_t)0, superblock_size, buf) < 0)
-            HGOTO_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "unable to write superblock")
+    FUNC_ENTER_STATIC
 
-        /* Check for newer version of superblock format & superblock extension */
-        if(sblock->super_vers >= HDF5_SUPERBLOCK_VERSION_2 && H5F_addr_defined(sblock->ext_addr)) {
-            H5O_loc_t 	ext_loc;        /* "Object location" for superblock extension */
+    /* Sanity check */
+    HDassert(sblock);
+    HDassert(sblock->cache_info.magic == H5C__H5C_CACHE_ENTRY_T_BAD_MAGIC);
+    HDassert(sblock->cache_info.type == H5AC_SUPERBLOCK);
 
-            /* Open the superblock extension's object header */
-            if(H5F_super_ext_open(f, sblock->ext_addr, &ext_loc) < 0)
-                HGOTO_ERROR(H5E_FILE, H5E_CANTOPENOBJ, FAIL, "unable to open file's superblock extension")
+    /* Destroy superblock */
+    if(H5F__super_free(sblock) < 0)
+        HGOTO_ERROR(H5E_BTREE, H5E_CANTFREE, FAIL, "unable to free superblock")
 
-            /* Check for ignoring the driver info for this file */
-            if(!H5F_HAS_FEATURE(f, H5FD_FEAT_IGNORE_DRVRINFO)) {
-                /* Check for driver info message */
-                H5_CHECKED_ASSIGN(driver_size, size_t, H5FD_sb_size(f->shared->lf), hsize_t);
-                if(driver_size > 0) {
-                    H5O_drvinfo_t drvinfo;      /* Driver info */
-                    uint8_t dbuf[H5F_MAX_DRVINFOBLOCK_SIZE];  /* Driver info block encoding buffer */
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* H5F__cache_superblock_free_icr() */
 
-                    /* Sanity check */
-                    HDassert(driver_size <= H5F_MAX_DRVINFOBLOCK_SIZE);
+
+/*-------------------------------------------------------------------------
+ * Function:    H5F__cache_drvrinfo_get_load_size
+ *
+ * Purpose:     Compute the size of the data structure on disk.
+ *
+ * Return:      Non-negative on success/Negative on failure
+ *
+ * Programmer:  Quincey Koziol
+ *              koziol@hdfgroup.org
+ *              July 20, 2013
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5F__cache_drvrinfo_get_load_size(const void H5_ATTR_UNUSED *udata, size_t *image_len)
+{
+    FUNC_ENTER_STATIC_NOERR
 
-                    /* Encode driver-specific data */
-                    if(H5FD_sb_encode(f->shared->lf, drvinfo.name, dbuf) < 0)
-                        HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "unable to encode driver information")
+    /* Check arguments */
+    HDassert(image_len);
 
-                    /* Write driver info information to the superblock extension */
-                    drvinfo.len = driver_size;
-                    drvinfo.buf = dbuf;
-                    if(H5O_msg_write(&ext_loc, H5O_DRVINFO_ID, H5O_MSG_FLAG_DONTSHARE, H5O_UPDATE_TIME, &drvinfo, dxpl_id) < 0)
-                        HGOTO_ERROR(H5E_FILE, H5E_WRITEERROR, FAIL, "unable to update driver info header message")
+    /* Set the initial image length size */
+    *image_len = H5F_DRVINFOBLOCK_HDR_SIZE;     /* Fixed size portion of driver info block */
 
-                } /* end if */
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5F__cache_drvrinfo_get_load_size() */
 
-            } /* end if */
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F__cache_drvrinfo_deserialize
+ *
+ * Purpose:	Loads an object from the disk.
+ *
+ * Return:	Success:	Pointer to a new B-tree.
+ *		Failure:	NULL
+ *
+ * Programmer:	Quincey Koziol
+ *		koziol@hdfgroup.org
+ *		July 20 2013
+ *
+ *-------------------------------------------------------------------------
+ */
+static void *
+H5F__cache_drvrinfo_deserialize(const void *_image, size_t len, void *_udata,
+    hbool_t H5_ATTR_UNUSED *dirty)
+{
+    H5O_drvinfo_t       *drvinfo = NULL; /* Driver info */
+    H5F_drvrinfo_cache_ud_t *udata = (H5F_drvrinfo_cache_ud_t *)_udata;     /* User data */
+    const uint8_t	*image = (const uint8_t *)_image;       /* Pointer into raw data buffer */
+    char                drv_name[9];    /* Name of driver */
+    unsigned            drv_vers;       /* Version of driver info block */
+    H5O_drvinfo_t       *ret_value;     /* Return value */
 
-            /* Close the superblock extension object header */
-            if(H5F_super_ext_close(f, &ext_loc, dxpl_id, FALSE) < 0)
-                HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEOBJ, FAIL, "unable to close file's superblock extension")
-        } /* end if */
+    FUNC_ENTER_STATIC
+
+    /* Sanity check */
+    HDassert(image);
+    HDassert(len >= H5F_DRVINFOBLOCK_HDR_SIZE);
+    HDassert(udata);
+    HDassert(udata->f);
+
+    /* Allocate space for the driver info */
+    if(NULL == (drvinfo = (H5O_drvinfo_t *)H5MM_calloc(sizeof(H5O_drvinfo_t))))
+	HGOTO_ERROR(H5E_FILE, H5E_CANTALLOC, NULL, "memory allocation failed for driver info message")
+
+    /* Version number */
+    drv_vers = *image++;
+    if(drv_vers != HDF5_DRIVERINFO_VERSION_0)
+        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, NULL, "bad driver information block version number")
+
+    image += 3; /* reserved bytes */
+
+    /* Driver info size */
+    UINT32DECODE(image, drvinfo->len);
+
+    /* Driver name and/or version */
+    HDstrncpy(drv_name, (const char *)image, (size_t)8);
+    drv_name[8] = '\0';
+    image += 8; /* advance past name/version */
+
+    /* Handle metadata cache retry for variable-sized portion of the driver info block */
+    if(len != (H5F_DRVINFOBLOCK_HDR_SIZE + drvinfo->len)) {
+        /* Sanity check */
+        HDassert(len == H5F_DRVINFOBLOCK_HDR_SIZE);
+
+        /* extend the eoa if required so that we can read the complete driver info block */
+        {
+            haddr_t eoa;
+            haddr_t min_eoa;
+
+            /* get current eoa... */
+	    if ((eoa = H5FD_get_eoa(udata->f->shared->lf, H5FD_MEM_SUPER)) == HADDR_UNDEF)
+                HGOTO_ERROR(H5E_RESOURCE, H5E_CANTGET, NULL, "driver get_eoa request failed")
+
+            /* ... if it is too small, extend it. */
+            min_eoa = udata->driver_addr + H5F_DRVINFOBLOCK_HDR_SIZE + drvinfo->len;
+
+            if ( H5F_addr_gt(min_eoa, eoa) )
+                if(H5FD_set_eoa(udata->f->shared->lf, H5FD_MEM_SUPER, min_eoa) < 0)
+                    HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, NULL, \
+                        "set end of space allocation request failed")
+        }        
 
-        /* Reset the dirty flag.  */
-        sblock->cache_info.is_dirty = FALSE;
+    } /* end if */
+    else {
+        /* Validate and decode driver information */
+        if(H5FD_sb_load(udata->f->shared->lf, drv_name, image) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTDECODE, NULL, "unable to decode driver information")
     } /* end if */
 
-    if(destroy)
-        if(H5F_sblock_dest(f, sblock) < 0)
-            HGOTO_ERROR(H5E_FSPACE, H5E_CLOSEERROR, FAIL, "can't close superblock")
+    /* Sanity check */
+    HDassert((size_t)(image - (const uint8_t *)_image) <= len);
+
+    /* Set return value */
+    ret_value = drvinfo;
 
 done:
+    /* Release the [possibly partially initialized] driver info message on error */
+    if(!ret_value && drvinfo)
+        H5MM_xfree(drvinfo);
+
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5F_sblock_flush() */
+} /* end H5F__cache_drvrinfo_deserialize() */
 
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_sblock_dest
+ * Function:    H5F__cache_drvrinfo_image_len
  *
- * Purpose:     Frees memory used by the superblock.
+ * Purpose:     Compute the size of the data structure on disk.
  *
  * Return:      Non-negative on success/Negative on failure
  *
- * Programmer:  Mike McGreevy
- *              April 8, 2009
+ * Programmer:  Quincey Koziol
+ *              koziol@hdfgroup.org
+ *              July 20, 2013
  *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F_sblock_dest(H5F_t H5_ATTR_UNUSED *f, H5F_super_t* sblock)
+H5F__cache_drvrinfo_image_len(const void *_thing, size_t *image_len,
+    hbool_t H5_ATTR_UNUSED *compressed_ptr, size_t H5_ATTR_UNUSED *compressed_image_len_ptr)
 {
-    herr_t ret_value = SUCCEED;         /* Return value */
+    const H5O_drvinfo_t *drvinfo = (const H5O_drvinfo_t *)_thing;       /* Pointer to the object */
 
-    FUNC_ENTER_NOAPI_NOINIT
+    FUNC_ENTER_STATIC_NOERR
 
-    /* Sanity check */
-    HDassert(sblock);
+    /* Check arguments */
+    HDassert(drvinfo);
+    HDassert(drvinfo->cache_info.magic == H5C__H5C_CACHE_ENTRY_T_MAGIC);
+    HDassert(drvinfo->cache_info.type == H5AC_DRVRINFO);
+    HDassert(image_len);
+    HDassert(compressed_ptr);
 
-    /* Free superblock */
-    if(H5F__super_free(sblock) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTFREE, FAIL, "unable to destroy superblock")
+    /* Set the image length size */
+    *image_len = (size_t)(H5F_DRVINFOBLOCK_HDR_SIZE +   /* Fixed-size portion of driver info block */
+        drvinfo->len);                                  /* Variable-size portion of driver info block */
 
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5F_sblock_dest() */
+    FUNC_LEAVE_NOAPI(SUCCEED)
+} /* end H5F__cache_drvrinfo_image_len() */
 
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_sblock_clear
+ * Function:	H5F__cache_drvrinfo_serialize
  *
- * Purpose:     Mark the superblock as no longer being dirty.
+ * Purpose:	Flushes a dirty object to disk.
  *
- * Return:      Non-negative on success/Negative on failure
+ * Return:	Non-negative on success/Negative on failure
  *
- * Programmer:  Mike McGreevy
- *              April 8, 2009
+ * Programmer:	Quincey Koziol
+ *		koziol@hdfgroup.org
+ *		July 20 2013
  *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F_sblock_clear(H5F_t *f, H5F_super_t *sblock, hbool_t destroy)
+H5F__cache_drvrinfo_serialize(const H5F_t *f, void *_image, size_t len,
+    void *_thing)
 {
-    herr_t ret_value = SUCCEED;         /* Return value */
+    H5O_drvinfo_t *drvinfo = (H5O_drvinfo_t *)_thing;   /* Pointer to the object */
+    uint8_t *image = (uint8_t *)_image;         /* Pointer into raw data buffer */
+    uint8_t *dbuf;              /* Pointer to beginning of driver info */
+    herr_t ret_value = SUCCEED; /* Return value */
 
-    FUNC_ENTER_NOAPI_NOINIT
+    FUNC_ENTER_STATIC
 
-    /*
-     * Check arguments.
-     */
-    HDassert(sblock);
+    /* check arguments */
+    HDassert(f);
+    HDassert(image);
+    HDassert(drvinfo);
+    HDassert(drvinfo->cache_info.magic == H5C__H5C_CACHE_ENTRY_T_MAGIC);
+    HDassert(drvinfo->cache_info.type == H5AC_DRVRINFO);
+    HDassert(len == (size_t)(H5F_DRVINFOBLOCK_HDR_SIZE + drvinfo->len));
+
+    /* Save pointer to beginning of driver info */
+    dbuf = image;
+
+    /* Encode the driver information block */
+    *image++ = HDF5_DRIVERINFO_VERSION_0; /* Version */
+    *image++ = 0; /* reserved */
+    *image++ = 0; /* reserved */
+    *image++ = 0; /* reserved */
+
+    /* Driver info size, excluding header */
+    UINT32ENCODE(image, drvinfo->len);
 
-    /* Reset the dirty flag.  */
-    sblock->cache_info.is_dirty = FALSE;
+    /* Encode driver-specific data */
+    if(H5FD_sb_encode(f->shared->lf, (char *)image, dbuf + H5F_DRVINFOBLOCK_HDR_SIZE) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "unable to encode driver information")
 
-    if(destroy)
-        if(H5F_sblock_dest(f, sblock) < 0)
-            HGOTO_ERROR(H5E_FILE, H5E_CANTFREE, FAIL, "unable to delete superblock")
+    /* Advance buffer pointer past name & variable-sized portion of driver info */
+    image += 8 + drvinfo->len;
+
+    /* Sanity check */
+    HDassert((size_t)(image - (uint8_t *)_image) <= len);
 
 done:
     FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5F_sblock_clear() */
+} /* H5F__cache_drvrinfo_serialize() */
 
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_sblock_size
+ * Function:	H5F__cache_drvrinfo_free_icr
  *
- * Purpose:     Returns the size of the superblock encoded on disk.
+ * Purpose:	Destroy/release an "in core representation" of a data
+ *              structure
  *
- * Return:      Non-negative on success/Negative on failure
+ * Note:	The metadata cache sets the object's cache_info.magic to
+ *		H5C__H5C_CACHE_ENTRY_T_BAD_MAGIC before calling a free_icr
+ *		callback (checked in assert).
  *
- * Programmer:  Mike McGreevy
- *              April 8, 2009
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Quincey Koziol
+ *              koziol@hdfgroup.org
+ *              July 20, 2013
  *
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5F_sblock_size(const H5F_t *f, const H5F_super_t *sblock, size_t *size_ptr)
+H5F__cache_drvrinfo_free_icr(void *_thing)
 {
-    FUNC_ENTER_NOAPI_NOINIT_NOERR
+    H5O_drvinfo_t *drvinfo = (H5O_drvinfo_t *)_thing;    /* Pointer to the object */
 
-    /* check arguments */
-    HDassert(f);
-    HDassert(sblock);
-    HDassert(size_ptr);
+    FUNC_ENTER_STATIC_NOERR
+
+    /* Check arguments */
+    HDassert(drvinfo);
+    HDassert(drvinfo->cache_info.magic == H5C__H5C_CACHE_ENTRY_T_BAD_MAGIC);
+    HDassert(drvinfo->cache_info.type == H5AC_DRVRINFO);
 
-    /* Set size value */
-    *size_ptr = (size_t)H5F_SUPERBLOCK_SIZE(sblock->super_vers, f);
+    /* Destroy driver info message */
+    H5MM_xfree(drvinfo);
 
     FUNC_LEAVE_NOAPI(SUCCEED)
-} /* end H5F_sblock_size() */
+} /* H5F__cache_drvrinfo_free_icr() */