[svn-r11022] Purpose:

    Bug fix & code cleanup

Description:
    Don't unmount child files from a parent file if the parent file is
being held open by an object.

    Also, moved the mounting routines into their own source file and the
superblock routines into their own file also.

Solution:
    Moved the code for unmounting child files down in the H5F_close routine
and also add checks to the file and group mounting code to unmount child
files when the last object holding open a file closes.

Platforms tested:
    FreeBSD 4.11 (sleipnir)
    h5committest

9 files changed, 1456 insertions, 1164 deletions

diff --git a/src/H5F.c b/src/H5F.c
index 8c73e86..d1dfba1 100644
--- a/src/H5F.c
+++ b/src/H5F.c
@@ -61,21 +61,15 @@ typedef struct H5F_olist_t {
 } H5F_olist_t;    
 
 /* PRIVATE PROTOTYPES */
-static herr_t H5F_close(H5F_t *f);
 
 #ifdef NOT_YET
 static herr_t H5F_flush_all(hbool_t invalidate);
 static int H5F_flush_all_cb(void *f, hid_t fid, void *_invalidate);
 #endif /* NOT_YET */
 
-static hsize_t H5F_init_superblock(const H5F_t *f, hid_t dxpl_id);
-static herr_t H5F_write_superblock(H5F_t *f, hid_t dxpl_id, uint8_t *buf);
-static herr_t H5F_read_superblock(H5F_t *f, hid_t dxpl_id, H5G_entry_t *root_ent, haddr_t addr, uint8_t *buf, size_t buf_size);
-
 static H5F_t *H5F_new(H5F_file_t *shared, hid_t fcpl_id, hid_t fapl_id);
 static herr_t H5F_dest(H5F_t *f, hid_t dxpl_id);
 static herr_t H5F_flush(H5F_t *f, hid_t dxpl_id, H5F_scope_t scope, unsigned flags);
-static haddr_t H5F_locate_signature(H5FD_t *file, hid_t dxpl_id);
 static int H5F_get_objects(const H5F_t *f, unsigned types, int max_objs, hid_t *obj_id_list);
 static int H5F_get_objects_cb(void *obj_ptr, hid_t obj_id, void *key);
 static herr_t H5F_get_vfd_handle(const H5F_t *file, hid_t fapl, void** file_handle);
@@ -415,53 +409,6 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5F_term_unmount_cb 
- *
- * Purpose:	H5F_term_interface' callback function.  This routine
- *              unmounts child files from files that are in the "closing"
- *              state.
- *
- * Programmer:  Quincey Koziol
- *              Thursday, Jun 30, 2005
- *
- * Modification:
- *
- *-------------------------------------------------------------------------
- */
-static int
-H5F_term_unmount_cb(void *obj_ptr, hid_t obj_id, void UNUSED *key)
-{
-    H5F_t *f = (H5F_t *)obj_ptr;    /* Alias for search info */
-    unsigned u;                     /* Local index */
-    int      ret_value = FALSE;     /* Return value */
- 
-    FUNC_ENTER_NOAPI_NOINIT(H5F_term_unmount_cb)
-
-    assert(f);
-
-    if(f->mtab.nmounts) {
-        /* Unmount all child files */
-        for (u=0; u<f->mtab.nmounts; u++) {
-            f->mtab.child[u].file->mtab.parent = NULL;
-            if(H5G_close(f->mtab.child[u].group)<0)
-                HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEOBJ, FAIL, "can't close child group")
-            if(H5F_close(f->mtab.child[u].file)<0)
-                HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL, "can't close child file")
-        } /* end if */
-        f->mtab.nmounts = 0;
-
-        /* Decrement reference count for file */
-        H5I_dec_ref(obj_id);
-    } /* end if */
-    else
-        HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL, "no files to unmount")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value);
-} /* end H5F_term_unmount_cb() */
-
-
-/*-------------------------------------------------------------------------
  * Function:	H5F_term_interface
  *
  * Purpose:	Terminate this interface: free all memory and reset global
@@ -1400,7 +1347,7 @@ H5F_equal(void *_haystack, hid_t UNUSED id, void *_needle)
  *		Rewritten to use the virtual file layer.
  *-------------------------------------------------------------------------
  */
-static haddr_t
+haddr_t
 H5F_locate_signature(H5FD_t *file, hid_t dxpl_id)
 {
     haddr_t	    addr, eoa;
@@ -2202,10 +2149,8 @@ done:
 hid_t
 H5Fcreate(const char *filename, unsigned flags, hid_t fcpl_id, hid_t fapl_id)
 {
-    
     H5F_t	*new_file = NULL;	/*file struct for new file	*/
     hid_t	ret_value;	        /*return value			*/
-    hid_t       estack_id;
 
     FUNC_ENTER_API(H5Fcreate, FAIL)
     H5TRACE4("i","sIuii",filename,flags,fcpl_id,fapl_id);
@@ -2430,600 +2375,6 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:    H5F_read_superblock
- *
- * Purpose:     Reads the superblock from the file or from the BUF. If
- *              ADDR is a valid address, then it reads it from the file.
- *              If not, then BUF must be non-NULL for it to read from the
- *              BUF.
- *
- * Return:      Success:        SUCCEED
- *              Failure:        FAIL
- *
- * Programmer:  Bill Wendling
- *              wendling@ncsa.uiuc.edu
- *              Sept 12, 2003
- *
- * Modifications:
- *              Raymond Lu
- *              May 24, 2005
- *              Started to check if driver(only family and multi drivers) 
- *              matches driver information saved in the superblock.  Wrong
- *              driver will result in a failure.
- * 
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5F_read_superblock(H5F_t *f, hid_t dxpl_id, H5G_entry_t *root_ent, haddr_t addr, uint8_t *buf, size_t buf_size)
-{
-    haddr_t             stored_eoa;         /*relative end-of-addr in file  */
-    haddr_t             eof;                /*end of file address           */
-    uint8_t            *q;                  /*ptr into temp I/O buffer      */
-    size_t              sizeof_addr = 0;
-    size_t              sizeof_size = 0;
-    const size_t        fixed_size = 24;    /*fixed sizeof superblock       */
-    unsigned            sym_leaf_k = 0;
-    size_t              variable_size;      /*variable sizeof superblock    */
-    unsigned            btree_k[H5B_NUM_BTREE_ID];  /* B-tree internal node 'K' values */
-    H5F_file_t         *shared = NULL;      /* shared part of `file'        */
-    H5FD_t             *lf = NULL;          /* file driver part of `shared' */
-    uint8_t            *p;                  /* Temporary pointer into encoding buffers */
-    uint8_t            *start_p;            /* Start of encoding buffers    */
-    unsigned            i;                  /* Index variable               */
-    unsigned            chksum;             /* Checksum temporary variable  */
-    size_t              driver_size;        /* Size of driver info block, in bytes */
-    char                driver_name[9];     /* Name of driver, for driver info block */
-    unsigned            super_vers;         /* Super block version          */
-    unsigned            freespace_vers;     /* Freespace info version       */
-    unsigned            obj_dir_vers;       /* Object header info version   */
-    unsigned            share_head_vers;    /* Shared header info version   */
-    uint8_t             sbuf[H5F_SUPERBLOCK_SIZE];     /* Local buffer                 */
-    H5P_genplist_t     *c_plist;            /* File creation property list  */
-    herr_t              ret_value = SUCCEED;
-
-    /* Decoding */
-    FUNC_ENTER_NOAPI(H5F_read_superblock, FAIL)
-
-    /* Short cuts */
-    shared = f->shared;
-    lf = shared->lf;
-
-    /* Get the shared file creation property list */
-    if (NULL == (c_plist = H5I_object(shared->fcpl_id)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
-
-    /* Read the superblock if it hasn't been read before. */
-    if (addr == HADDR_UNDEF) {
-        if (HADDR_UNDEF == (shared->super_addr=H5F_locate_signature(lf,dxpl_id)))
-            HGOTO_ERROR(H5E_FILE, H5E_NOTHDF5, FAIL, "unable to find file signature")
-    } else {
-        shared->super_addr = addr;
-    }
-
-    if (!buf) {
-        start_p = p = sbuf;
-        buf_size=sizeof(sbuf);
-
-        if (H5FD_set_eoa(lf, shared->super_addr + fixed_size) < 0 ||
-                H5FD_read(lf, H5FD_MEM_SUPER, dxpl_id, shared->super_addr, fixed_size, p) < 0)
-            HGOTO_ERROR(H5E_FILE, H5E_READERROR, FAIL, "unable to read superblock")
-    } else {
-        start_p = p = buf;
-    }
-
-    /* Signature, already checked */
-    p += H5F_SIGNATURE_LEN;
-
-    /* Superblock version */
-    super_vers = *p++;
-    if (super_vers > HDF5_SUPERBLOCK_VERSION_MAX) 
-        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "bad superblock version number")
-    if (H5P_set(c_plist, H5F_CRT_SUPER_VERS_NAME, &super_vers) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "unable to set superblock version")
-
-    /* Freespace version */
-    freespace_vers = *p++;
-    if (HDF5_FREESPACE_VERSION != freespace_vers) 
-        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "bad free space version number")
-    if (H5P_set(c_plist, H5F_CRT_FREESPACE_VERS_NAME, &freespace_vers) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "unable to free space version")
-
-    /* Root group version number */
-    obj_dir_vers = *p++;
-    if (HDF5_OBJECTDIR_VERSION != obj_dir_vers) 
-        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "bad object directory version number")
-    if (H5P_set(c_plist, H5F_CRT_OBJ_DIR_VERS_NAME, &obj_dir_vers) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "unable to set object directory version")
-
-    /* Skip over reserved byte */
-    p++;
-
-    /* Shared header version number */
-    share_head_vers = *p++;
-    if (HDF5_SHAREDHEADER_VERSION != share_head_vers) 
-        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "bad shared-header format version number")
-    if (H5P_set(c_plist, H5F_CRT_SHARE_HEAD_VERS_NAME, &share_head_vers) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "unable to set shared-header format version")
-
-    /* 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, FAIL, "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, FAIL, "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, FAIL, "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, FAIL, "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, FAIL, "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, FAIL, "unable to set rank for symbol table leaf nodes")
-    shared->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, FAIL, "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, FAIL, "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 consistency flags. Not really used yet */
-    UINT32DECODE(p, shared->consist_flags);
-    assert(((size_t)(p - start_p)) == fixed_size);
-
-    /* Decode the variable-length part of the superblock... */
-    variable_size = (super_vers>0 ? 4 : 0) +    /* Potential indexed storage B-tree internal 'K' value */
-                    H5F_SIZEOF_ADDR(f) +        /*base addr*/
-                    H5F_SIZEOF_ADDR(f) +        /*global free list*/
-                    H5F_SIZEOF_ADDR(f) +        /*end-of-address*/
-                    H5F_SIZEOF_ADDR(f) +        /*reserved address*/
-                    H5G_SIZEOF_ENTRY(f);        /*root group ptr*/
-    assert(fixed_size + variable_size <= buf_size);
-
-    /* The buffer (buf) is either passed in or the "local_buf" variable now */
-    if(!buf) {
-        if (H5FD_set_eoa(lf, shared->super_addr + fixed_size+variable_size) < 0 ||
-                H5FD_read(lf, H5FD_MEM_SUPER, dxpl_id, shared->super_addr + fixed_size,
-                          variable_size, p) < 0)
-            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "unable to read superblock")
-    } /* end if */
-
-    /*
-     * If the superblock version # is greater than 0, read in the indexed
-     * storage B-tree internal 'K' value
-     */
-    if (super_vers > 0) {
-        UINT16DECODE(p, btree_k[H5B_ISTORE_ID]);
-        p += 2;   /* reserved */
-    }
-    else
-        btree_k[H5B_ISTORE_ID] = HDF5_BTREE_ISTORE_IK_DEF;
-
-    /* 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, FAIL, "unable to set rank for btree internal nodes")
-    HDmemcpy(shared->btree_k, btree_k, sizeof(unsigned) * (size_t)H5B_NUM_BTREE_ID);    /* Keep a local copy also */
-
-    H5F_addr_decode(f, (const uint8_t **)&p, &shared->base_addr/*out*/);
-    H5F_addr_decode(f, (const uint8_t **)&p, &shared->freespace_addr/*out*/);
-    H5F_addr_decode(f, (const uint8_t **)&p, &stored_eoa/*out*/);
-    H5F_addr_decode(f, (const uint8_t **)&p, &shared->driver_addr/*out*/);
-    if (H5G_ent_decode(f, (const uint8_t **)&p, root_ent/*out*/) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "unable to read root symbol entry")
-
-    /*
-     * Check if superblock address is different from base address and
-     * adjust base address and "end of address" address if so.
-     */
-    if (!H5F_addr_eq(shared->super_addr,shared->base_addr)) {
-        /* Check if the superblock moved earlier in the file */
-        if (H5F_addr_lt(shared->super_addr, shared->base_addr))
-            stored_eoa -= (shared->base_addr - shared->super_addr);
-        else
-            /* The superblock moved later in the file */
-            stored_eoa += (shared->super_addr - shared->base_addr);
-
-        shared->base_addr = shared->super_addr;
-    } /* end if */
-
-    /* Compute super block checksum */
-    assert(sizeof(chksum) == sizeof(shared->super_chksum));
-    for (q = (uint8_t *)&chksum, chksum = 0, i = 0; i < fixed_size + variable_size; ++i)
-        q[i % sizeof(shared->super_chksum)] ^= start_p[i];
-
-    /* Set the super block checksum */
-    shared->super_chksum = chksum;
-
-    /* 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(shared->fam_to_sec2)
-        shared->driver_addr = HADDR_UNDEF;
-            
-    /* Decode the optional driver information block */
-    if (H5F_addr_defined(shared->driver_addr)) {
-        haddr_t drv_addr = shared->base_addr + shared->driver_addr;
-        uint8_t dbuf[H5F_DRVINFOBLOCK_SIZE];     /* Local buffer                 */
-        size_t dbuf_size;               /* Size available for driver info */
-        const uint8_t *driver_p;        /* Remember beginning of driver info block */
-
-        if(!buf) {
-            driver_p = p = dbuf;
-            dbuf_size=sizeof(dbuf);
-
-            if (H5FD_set_eoa(lf, drv_addr + 16) < 0 ||
-                    H5FD_read(lf, H5FD_MEM_SUPER, dxpl_id, drv_addr, (size_t)16, p) < 0)
-                HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "unable to read driver information block")
-        } /* end if */
-        else {
-            driver_p = p;
-            dbuf_size=buf_size-(p-start_p);
-        } /* end else */
-
-        /* Version number */
-        if (HDF5_DRIVERINFO_VERSION != *p++)
-            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "bad driver information block version number")
-
-        p += 3; /* reserved */
-
-        /* Driver info size */
-        UINT32DECODE(p, driver_size);
-
-        /* Driver name and/or version */
-        HDstrncpy(driver_name, (const char *)p, (size_t)8);
-        driver_name[8] = '\0';
-        p += 8; /* advance past name/version */
-
-        /* Read driver information and decode */
-        assert((driver_size + 16) <= dbuf_size);
-
-        if(!buf) {
-            if (H5FD_set_eoa(lf, drv_addr + 16 + driver_size) < 0 ||
-                    H5FD_read(lf, H5FD_MEM_SUPER, dxpl_id, drv_addr+16, driver_size, p) < 0)
-                HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "unable to read file driver information")
-        } /* end if */
-
-        /* Check if driver matches driver information saved. Unfortunately, we can't push this 
-         * function to each specific driver because we're checking if the driver is correct.*/
-        if(!HDstrncmp(driver_name, "NCSAfami", 8) && HDstrcmp(lf->cls->name, "family"))
-            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "family driver should be used")
-        if(!HDstrncmp(driver_name, "NCSAmult", 8) && HDstrcmp(lf->cls->name, "multi"))
-            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "multi driver should be used")
-           
-        if (H5FD_sb_decode(lf, driver_name, p) < 0)
-            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "unable to decode driver information")
-    
-        /* Compute driver info block checksum */
-        assert(sizeof(chksum) == sizeof(shared->drvr_chksum));
-        for (q = (uint8_t *)&chksum, chksum = 0, i = 0; i < (driver_size + 16); ++i)
-            q[i % sizeof(shared->drvr_chksum)] ^= driver_p[i];
-
-        /* Set the driver info block checksum */
-        shared->drvr_chksum = chksum;
-    } /* end if */
-    
-    /*
-     * The user-defined data is the area of the file before the base
-     * address.
-     */
-    if (H5P_set(c_plist, H5F_CRT_USER_BLOCK_NAME, &shared->base_addr) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "unable to set usr block size")
-
-    /*
-     * 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)))
-        HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "unable to determine file size")
-
-#ifdef H5_HAVE_FPHDF5
-    if (!H5FD_is_fphdf5_driver(lf) || H5FD_fphdf5_is_captain(lf))
-#endif  /* !H5_HAVE_FPHDF5 */
-        if (eof < stored_eoa)
-            HGOTO_ERROR(H5E_FILE, H5E_TRUNCATED, FAIL, "truncated file")
-    
-    /*
-     * Tell the file driver how much address space has already been
-     * allocated so that it knows how to allocate additional memory.
-     */
-    if (H5FD_set_eoa(lf, stored_eoa) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "unable to set end-of-address marker for file")
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-}
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5F_init_superblock
- *
- * Purpose:     Allocates the superblock for the file and initializes
- *              information about the superblock in memory.  Does not write
- *              any superblock information to the file.
- *
- * Return:      Success:        SUCCEED
- *              Failure:        FAIL
- *
- * Programmer:  Quincey Koziol
- *              koziol@ncsa.uiuc.edu
- *              Sept 15, 2003
- *
- * Modifications:
- *
- *-------------------------------------------------------------------------
- */
-static hsize_t
-H5F_init_superblock(const H5F_t *f, hid_t dxpl_id)
-{
-    hsize_t         userblock_size = 0;         /* Size of userblock, in bytes */
-    size_t          superblock_size;            /* Size of superblock, in bytes     */
-    size_t          driver_size;                /* Size of driver info block (bytes)*/
-    unsigned        super_vers;                 /* Super block version              */
-    haddr_t         addr;                       /* Address of superblock            */
-    H5P_genplist_t *plist;                      /* Property list                    */
-    hsize_t         ret_value;
-
-    /* Encoding */
-    FUNC_ENTER_NOAPI(H5F_init_superblock, UFAIL)
-
-    /* Get the shared file creation property list */
-    if (NULL == (plist = H5I_object(f->shared->fcpl_id)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, UFAIL, "not a property list")
-
-    /*
-     * The superblock starts immediately after the user-defined
-     * header, which we have already insured is a proper size. The
-     * base address is set to the same thing as the superblock for
-     * now.
-     */
-    if(H5P_get(plist, H5F_CRT_USER_BLOCK_NAME, &userblock_size) < 0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTGET, UFAIL, "unable to get user block size")
-    f->shared->super_addr = userblock_size;
-    f->shared->base_addr = f->shared->super_addr;
-    f->shared->consist_flags = 0x03;
-
-    /* Grab superblock version from property list */
-    if (H5P_get(plist, H5F_CRT_SUPER_VERS_NAME, &super_vers) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, UFAIL, "unable to get super block version")
-
-    /* Compute the size of the superblock */
-    superblock_size=H5F_SIGNATURE_LEN   /* Signature length (8 bytes) */
-        + 16                            /* Length of required fixed-size portion */
-        + ((super_vers>0) ? 4 : 0)      /* Version specific fixed-size portion */
-        + 4 * H5F_sizeof_addr(f)        /* Variable-sized addresses */
-        + H5G_SIZEOF_ENTRY(f);          /* Size of root group symbol table entry */
-
-    /* Compute the size of the driver information block. */
-    H5_ASSIGN_OVERFLOW(driver_size, H5FD_sb_size(f->shared->lf), hsize_t, size_t);
-    if (driver_size > 0)
-	driver_size += 16; /* Driver block header */
-
-    /*
-     * Allocate space for the userblock, superblock, and driver info
-     * block. We do it with one allocation request because the
-     * userblock and superblock need to be at the beginning of the
-     * file and only the first allocation request is required to
-     * return memory at format address zero.
-     */
-
-    H5_CHECK_OVERFLOW(f->shared->base_addr, haddr_t, hsize_t);
-    addr = H5FD_alloc(f->shared->lf, H5FD_MEM_SUPER, dxpl_id,
-                      ((hsize_t)f->shared->base_addr + superblock_size + driver_size));
-
-    if (HADDR_UNDEF == addr)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, UFAIL,
-                    "unable to allocate file space for userblock and/or superblock")
-
-    if (0 != addr)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, UFAIL,
-                    "file driver failed to allocate userblock and/or superblock at address zero")
-
-    /*
-     * The file driver information block begins immediately after the
-     * superblock.
-     */
-    if (driver_size > 0)
-        f->shared->driver_addr = superblock_size;
-
-    /* Return the size of the super block+driver info block */
-    ret_value=superblock_size+driver_size;
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5F_init_superblock() */
-
-
-/*-------------------------------------------------------------------------
- * Function:    H5F_write_superblock
- *
- * Purpose:     Writes (and optionally allocates) the superblock for the file.
- *              If BUF is non-NULL, then write the serialized superblock
- *              information into it. It should be a buffer of size
- *              H5F_SUPERBLOCK_SIZE + H5F_DRVINFOBLOCK_SIZE or larger.
- *
- * Return:      Success:        SUCCEED
- *              Failure:        FAIL
- *
- * Programmer:  Bill Wendling
- *              wendling@ncsa.uiuc.edu
- *              Sept 12, 2003
- *
- * Modifications:
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5F_write_superblock(H5F_t *f, hid_t dxpl_id, uint8_t *buf)
-{
-    uint8_t         sbuf[H5F_SUPERBLOCK_SIZE];  /* Superblock encoding buffer       */
-    uint8_t         dbuf[H5F_DRVINFOBLOCK_SIZE];/* Driver info block encoding buffer*/
-    uint8_t        *p = NULL;                   /* Ptr into encoding buffers        */
-    unsigned        i;                          /* Index variable                   */
-    unsigned        chksum;                     /* Checksum temporary variable      */
-    size_t          superblock_size;            /* Size of superblock, in bytes     */
-    size_t          driver_size;                /* Size of driver info block (bytes)*/
-    char            driver_name[9];             /* Name of driver, for driver info block */
-    unsigned        super_vers;                 /* Super block version              */
-    unsigned        freespace_vers;             /* Freespace info version           */
-    unsigned        obj_dir_vers;               /* Object header info version       */
-    unsigned        share_head_vers;            /* Shared header info version       */
-    H5P_genplist_t *plist;                      /* Property list                    */
-    herr_t          ret_value = SUCCEED;
-
-    /* Encoding */
-    FUNC_ENTER_NOAPI(H5F_write_superblock, FAIL)
-
-    /* Get the shared file creation property list */
-    if (NULL == (plist = H5I_object(f->shared->fcpl_id)))
-        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a property list")
-
-    /* Grab values from property list */
-    if (H5P_get(plist, H5F_CRT_SUPER_VERS_NAME, &super_vers) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "unable to get super block version")
-    if (H5P_get(plist, H5F_CRT_FREESPACE_VERS_NAME, &freespace_vers) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "unable to get free space version")
-    if (H5P_get(plist, H5F_CRT_OBJ_DIR_VERS_NAME, &obj_dir_vers) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "unable to get object directory version")
-    if (H5P_get(plist, H5F_CRT_SHARE_HEAD_VERS_NAME, &share_head_vers) < 0)
-        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "unable to get shared-header format version")
-
-    /* Encode the file super block */
-    p = sbuf;
-    HDmemcpy(p, H5F_SIGNATURE, (size_t)H5F_SIGNATURE_LEN);
-    p += H5F_SIGNATURE_LEN;
-    *p++ = (uint8_t)super_vers;
-    *p++ = (uint8_t)freespace_vers;
-    *p++ = (uint8_t)obj_dir_vers;
-    *p++ = 0;   /* reserved*/
-    *p++ = (uint8_t)share_head_vers;
-    assert (H5F_SIZEOF_ADDR(f) <= 255);
-    *p++ = (uint8_t)H5F_SIZEOF_ADDR(f);
-    assert (H5F_SIZEOF_SIZE(f) <= 255);
-    *p++ = (uint8_t)H5F_SIZEOF_SIZE(f);
-    *p++ = 0;   /* reserved */
-    UINT16ENCODE(p, f->shared->sym_leaf_k);
-    UINT16ENCODE(p, f->shared->btree_k[H5B_SNODE_ID]);
-    UINT32ENCODE(p, f->shared->consist_flags);    
-
-    /*
-     * Versions of the superblock >0 have the indexed storage B-tree
-     * internal 'K' value stored
-     */
-    if (super_vers > 0) {
-        UINT16ENCODE(p, f->shared->btree_k[H5B_ISTORE_ID]);
-        *p++ = 0;   /*reserved */
-        *p++ = 0;   /*reserved */
-    }
-
-    H5F_addr_encode(f, &p, f->shared->base_addr);
-    H5F_addr_encode(f, &p, f->shared->freespace_addr);
-    H5F_addr_encode(f, &p, H5FD_get_eoa(f->shared->lf));
-    H5F_addr_encode(f, &p, f->shared->driver_addr);
-    if(H5G_ent_encode(f, &p, H5G_entof(f->shared->root_grp))<0)
-        HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "unable to encode root group information")
-
-    H5_ASSIGN_OVERFLOW(superblock_size, p - sbuf, int, size_t);
-
-    /* Double check we didn't overrun the block (unlikely) */
-    assert(superblock_size <= sizeof(sbuf));
-
-    /* Encode the driver information block. */
-    H5_ASSIGN_OVERFLOW(driver_size, H5FD_sb_size(f->shared->lf), hsize_t, size_t);
-
-    if (driver_size > 0) {
-	driver_size += 16; /* Driver block header */
-
-        /* Double check we didn't overrun the block (unlikely) */
-	assert(driver_size <= sizeof(dbuf));
-
-        /* Encode the driver information block */
-	p = dbuf;
-
-	*p++ = HDF5_DRIVERINFO_VERSION; /* Version */
-	*p++ = 0; /* reserved */
-	*p++ = 0; /* reserved */
-	*p++ = 0; /* reserved */
-
-	/* Driver info size, excluding header */
-	UINT32ENCODE(p, driver_size - 16);
-
-	/* Encode driver-specific data */
-	if (H5FD_sb_encode(f->shared->lf, driver_name, dbuf + 16) < 0)
-	    HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "unable to encode driver information")
-
-	/* Driver name */
-	HDmemcpy(dbuf + 8, driver_name, (size_t)8);
-    } /* end if */
-
-    /* Compute super block checksum */
-    assert(sizeof(chksum) == sizeof(f->shared->super_chksum));
-
-    for (p = (uint8_t *)&chksum, chksum = 0, i = 0; i < superblock_size; ++i)
-        p[i % sizeof(f->shared->super_chksum)] ^= sbuf[i];
-
-    /* Compare with current checksums */
-    if (chksum != f->shared->super_chksum) {
-        /* Write superblock */
-        if (H5FD_write(f->shared->lf, H5FD_MEM_SUPER, dxpl_id,
-                       f->shared->super_addr, superblock_size, sbuf) < 0)
-            HGOTO_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "unable to write superblock")
-
-        /* Update checksum information if different */
-        f->shared->super_chksum = chksum;
-    } /* end if */
-
-    /* Check for driver info block */
-    if (HADDR_UNDEF != f->shared->driver_addr) {
-        /* Compute driver info block checksum */
-        assert(sizeof(chksum) == sizeof(f->shared->drvr_chksum));
-
-        for (p = (uint8_t *)&chksum, chksum = 0, i = 0; i < driver_size; ++i)
-            p[i % sizeof(f->shared->drvr_chksum)] ^= dbuf[i];
-
-        /* Compare with current checksums */
-        if (chksum != f->shared->drvr_chksum) {
-            /* Write driver information block */
-            if (H5FD_write(f->shared->lf, H5FD_MEM_SUPER, dxpl_id,
-                           f->shared->base_addr + f->shared->driver_addr, driver_size, dbuf) < 0)
-                HGOTO_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "unable to write driver information block")
-
-            /* Update checksum information if different */
-            f->shared->drvr_chksum = chksum;
-        } /* end if */
-    } /* end if */
-
-    /* Update the user's buffer, if given */
-    if (buf) {
-        HDmemcpy(buf, sbuf, superblock_size);
-        HDmemcpy(&buf[superblock_size], dbuf, driver_size);
-    } /* end if */
-
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-}
-
-
-/*-------------------------------------------------------------------------
  * Function:	H5F_flush
  *
  * Purpose:	Flushes (and optionally invalidates) cached data plus the
@@ -3250,10 +2601,9 @@ done:
  *
  *-------------------------------------------------------------------------
  */
-static herr_t
+herr_t
 H5F_close(H5F_t *f)
 {
-    unsigned		u;              /* Local index variable */
     herr_t	        ret_value = SUCCEED;    /* Return value */
 
     FUNC_ENTER_NOAPI_NOINIT(H5F_close)
@@ -3280,19 +2630,6 @@ H5F_close(H5F_t *f)
         HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL, "can't close file, there are objects still open")
 
     /*
-     * Unmount and close each child before closing the current file.
-     */
-    assert(NULL==f->mtab.parent);
-    for (u=0; u<f->mtab.nmounts; u++) {
-	f->mtab.child[u].file->mtab.parent = NULL;
-	if(H5G_close(f->mtab.child[u].group)<0)
-            HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEOBJ, FAIL, "can't close child group")
-	if(H5F_close(f->mtab.child[u].file)<0)
-            HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL, "can't close child file")
-    } /* end if */
-    f->mtab.nmounts = 0;
-
-    /*
      * Close file according to close degree:
      *
      *  H5F_CLOSE_WEAK:	if there are still objects open, wait until
@@ -3323,6 +2660,26 @@ H5F_close(H5F_t *f)
                     1 == f->nopen_objs?"that header is":"those headers are");
                 }
 #endif
+                /* If the only open objects are the groups that are mount points, */
+                /* allow the file to close and shut things down */
+                if(f->nopen_objs == f->mtab.nmounts) {
+                    unsigned u;         /* Local index variable */
+                    hbool_t really_close;  /* Whether to delay the file close by going to a "closing" state */
+
+                    /* Check for open groups on mount points */
+                    really_close = TRUE;
+                    for(u = 0; u < f->mtab.nmounts; u++) {
+                        if(H5G_get_shared_count(f->mtab.child[u].group) > 1) {
+                            really_close = FALSE;
+                            break;
+                        } /* end if */
+                    } /* end for */
+
+                    /* If we really want to close this file now */
+                    if(really_close)
+                        break;
+                } /* end if */
+
                 /* Register an ID for closing the file later */
                 if (!f->closing)
                     f->closing  = H5I_register(H5I_FILE_CLOSING, f);
@@ -3395,6 +2752,13 @@ H5F_close(H5F_t *f)
             HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL, "can't close file, unknown file close degree")
     } /* end switch */
 
+    /*
+     * Unmount and close each child before closing the current file.
+     */
+    assert(NULL==f->mtab.parent);
+    if(H5F_close_mounts(f) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL, "can't unmount child file")
+
     /* Invalidate file ID */
     f->file_id = -1;
 
@@ -3493,490 +2857,6 @@ done:
 
 
 /*-------------------------------------------------------------------------
- * Function:	H5F_mount
- *
- * Purpose:	Mount file CHILD onto the group specified by LOC and NAME,
- *		using mount properties in PLIST.  CHILD must not already be
- *		mouted and must not be a mount ancestor of the mount-point.
- *
- * Return:	Non-negative on success/Negative on failure
- *
- * Programmer:	Robb Matzke
- *              Tuesday, October  6, 1998
- *
- * Modifications:
- *
- * 	Robb Matzke, 1998-10-14
- *	The reference count for the mounted H5F_t is incremented.
- *
- *      Pedro Vicente, <pvn@ncsa.uiuc.edu> 22 Aug 2002
- *      Added `id to name' support.
- *
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5F_mount(H5G_entry_t *loc, const char *name, H5F_t *child,
-	  hid_t UNUSED plist_id, hid_t dxpl_id)
-{
-    H5G_t	*mount_point = NULL;	/*mount point group		*/
-    H5G_entry_t	*mp_ent = NULL;		/*mount point symbol table entry*/
-    H5F_t	*ancestor = NULL;	/*ancestor files		*/
-    H5F_t	*parent = NULL;		/*file containing mount point	*/
-    unsigned	lt, rt, md;		/*binary search indices		*/
-    int		cmp;			/*binary search comparison value*/
-    H5G_entry_t	*ent = NULL;		/*temporary symbol table entry	*/
-    H5G_entry_t  mp_open_ent;     /* entry of moint point to be opened */
-    H5RS_str_t  *name_r;                /* Ref-counted version of name */
-    herr_t	ret_value = SUCCEED;	/*return value			*/
-    
-    FUNC_ENTER_NOAPI_NOINIT(H5F_mount)
-
-    assert(loc);
-    assert(name && *name);
-    assert(child);
-    assert(TRUE==H5P_isa_class(plist_id,H5P_MOUNT));
-
-    /*
-     * Check that the child isn't mounted, that the mount point exists, and
-     * that the mount wouldn't introduce a cycle in the mount tree.
-     */
-    if (child->mtab.parent)
-        HGOTO_ERROR(H5E_FILE, H5E_MOUNT, FAIL, "file is already mounted")
-    if (H5G_find(loc, name, NULL, &mp_open_ent/*out*/, H5AC_dxpl_id) < 0)
-        HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "group not found")
-    if (NULL==(mount_point=H5G_open(&mp_open_ent, dxpl_id)))
-        HGOTO_ERROR(H5E_FILE, H5E_MOUNT, FAIL, "mount point not found")
-
-    parent = H5G_fileof(mount_point);
-    mp_ent = H5G_entof(mount_point);
-    for (ancestor=parent; ancestor; ancestor=ancestor->mtab.parent) {
-	if (ancestor==child)
-	    HGOTO_ERROR(H5E_FILE, H5E_MOUNT, FAIL, "mount would introduce a cycle")
-    }
-    
-    /*
-     * Use a binary search to locate the position that the child should be
-     * inserted into the parent mount table.  At the end of this paragraph
-     * `md' will be the index where the child should be inserted.
-     */
-    lt = md = 0;
-    rt=parent->mtab.nmounts;
-    cmp = -1;
-    while (lt<rt && cmp) {
-	md = (lt+rt)/2;
-	ent = H5G_entof(parent->mtab.child[md].group);
-	cmp = H5F_addr_cmp(mp_ent->header, ent->header);
-	if (cmp<0) {
-	    rt = md;
-	} else if (cmp>0) {
-	    lt = md+1;
-	}
-    }
-    if (cmp>0)
-        md++;
-    if (!cmp)
-	HGOTO_ERROR(H5E_FILE, H5E_MOUNT, FAIL, "mount point is already in use")
-    
-    /* Make room in the table */
-    if (parent->mtab.nmounts>=parent->mtab.nalloc) {
-	unsigned n = MAX(16, 2*parent->mtab.nalloc);
-	H5F_mount_t *x = H5MM_realloc(parent->mtab.child,
-				      n*sizeof(parent->mtab.child[0]));
-	if (!x)
-	    HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for mount table")
-	parent->mtab.child = x;
-	parent->mtab.nalloc = n;
-    }
-
-    /* Insert into table */
-    HDmemmove(parent->mtab.child+md+1, parent->mtab.child+md,
-        (parent->mtab.nmounts-md)*sizeof(parent->mtab.child[0]));
-    parent->mtab.nmounts++;
-    parent->mtab.child[md].group = mount_point;
-    parent->mtab.child[md].file = child;
-    child->mtab.parent = parent;
-    child->nrefs++;
-
-    /* Search the open IDs and replace names for mount operation */
-    /* We pass H5G_UNKNOWN as object type; search all IDs */
-    name_r=H5RS_wrap(name);
-    assert(name_r);
-    if (H5G_replace_name( H5G_UNKNOWN, loc, name_r, NULL, NULL, NULL, OP_MOUNT )<0)
-	HGOTO_ERROR(H5E_FILE, H5E_MOUNT, FAIL, "unable to replace name")
-    if(H5RS_decr(name_r)<0)
-	HGOTO_ERROR(H5E_FILE, H5E_CANTDEC, FAIL, "unable to decrement name string")
-
-done:
-    if (ret_value<0 && mount_point)
-	if(H5G_close(mount_point)<0)
-            HDONE_ERROR(H5E_FILE, H5E_CANTCLOSEOBJ, FAIL, "unable to close mounted group")
-
-    FUNC_LEAVE_NOAPI(ret_value)
-}
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5F_unmount
- *
- * Purpose:	Unmount the child which is mounted at the group specified by
- *		LOC and NAME or fail if nothing is mounted there.  Neither
- *		file is closed.
- *
- *		Because the mount point is specified by name and opened as a
- *		group, the H5G_namei() will resolve it to the root of the
- *		mounted file, not the group where the file is mounted.
- *
- * Return:	Non-negative on success/Negative on failure
- *
- * Programmer:	Robb Matzke
- *              Tuesday, October  6, 1998
- *
- * Modifications:
- *
- *      Robb Matzke, 1998-10-14
- *      The ref count for the child is decremented by calling H5F_close().
- *
- *      Pedro Vicente, <pvn@ncsa.uiuc.edu> 22 Aug 2002
- *      Added `id to name' support.
- * 
- *-------------------------------------------------------------------------
- */
-static herr_t
-H5F_unmount(H5G_entry_t *loc, const char *name, hid_t dxpl_id)
-{
-    H5G_t	*mounted = NULL;	/*mount point group		*/
-    H5G_entry_t	*mnt_ent = NULL;	/*mounted symbol table entry	*/
-    H5F_t	*child = NULL;		/*mounted file			*/
-    H5F_t	*parent = NULL;		/*file where mounted		*/
-    H5G_entry_t	*ent = NULL;		/*temporary symbol table entry	*/
-    H5G_entry_t mnt_open_ent;       /* entry used to open mount point*/
-    herr_t	ret_value = FAIL;	/*return value			*/
-    unsigned	i;			/*coutners			*/
-    unsigned	lt, rt, md=0;	        /*binary search indices		*/
-    int 	cmp;		        /*binary search comparison value*/
-    
-    FUNC_ENTER_NOAPI_NOINIT(H5F_unmount)
-
-    assert(loc);
-    assert(name && *name);
-
-    /*
-     * Get the mount point, or more precisely the root of the mounted file.
-     * If we get the root group and the file has a parent in the mount tree,
-     * then we must have found the mount point.
-     */
-    if (H5G_find(loc, name, NULL, &mnt_open_ent/*out*/, H5AC_dxpl_id) < 0)
-        HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "group not found")
-    if (NULL==(mounted=H5G_open(&mnt_open_ent, dxpl_id)))
-        HGOTO_ERROR(H5E_FILE, H5E_MOUNT, FAIL, "mount point not found")
-    child = H5G_fileof(mounted);
-    mnt_ent = H5G_entof(mounted);
-    ent = H5G_entof(child->shared->root_grp);
-
-    if (child->mtab.parent &&
-	H5F_addr_eq(mnt_ent->header, ent->header)) {
-	/*
-	 * We've been given the root group of the child.  We do a reverse
-	 * lookup in the parent's mount table to find the correct entry.
-	 */
-	parent = child->mtab.parent;
-	for (i=0; i<parent->mtab.nmounts; i++) {
-	    if (parent->mtab.child[i].file==child) {
-                /* Search the open IDs replace names to reflect unmount operation */
-                if (H5G_replace_name( H5G_UNKNOWN, mnt_ent, mnt_ent->user_path_r, NULL, NULL, NULL, OP_UNMOUNT )<0)
-                    HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to replace name ")
-
-		/* Unmount the child */
-		parent->mtab.nmounts -= 1;
-		if(H5G_close(parent->mtab.child[i].group)<0)
-                    HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEOBJ, FAIL, "unable to close unmounted group")
-		child->mtab.parent = NULL;
-		if(H5F_close(child)<0)
-                    HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL, "unable to close unmounted file")
-		HDmemmove(parent->mtab.child+i, parent->mtab.child+i+1,
-                    (parent->mtab.nmounts-i)* sizeof(parent->mtab.child[0]));
-		ret_value = SUCCEED;
-	    }
-	}
-	assert(ret_value>=0);
-	
-    } else {
-	/*
-	 * We've been given the mount point in the parent.  We use a binary
-	 * search in the parent to locate the mounted file, if any.
-	 */
-	parent = child; /*we guessed wrong*/
-	lt = 0;
-        rt = parent->mtab.nmounts;
-	cmp = -1;
-	while (lt<rt && cmp) {
-	    md = (lt+rt)/2;
-	    ent = H5G_entof(parent->mtab.child[md].group);
-	    cmp = H5F_addr_cmp(mnt_ent->header, ent->header);
-	    if (cmp<0) {
-		rt = md;
-	    } else {
-		lt = md+1;
-	    }
-	}
-	if (cmp)
-	    HGOTO_ERROR(H5E_FILE, H5E_MOUNT, FAIL, "not a mount point")
-
-	/* Unmount the child */
-	parent->mtab.nmounts -= 1;
-	if(H5G_close(parent->mtab.child[md].group)<0)
-            HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEOBJ, FAIL, "unable to close unmounted group")
-	parent->mtab.child[md].file->mtab.parent = NULL;
-	if(H5F_close(parent->mtab.child[md].file)<0)
-            HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL, "unable to close unmounted file")
-	HDmemmove(parent->mtab.child+md, parent->mtab.child+md+1,
-            (parent->mtab.nmounts-md)*sizeof(parent->mtab.child[0]));
-	ret_value = SUCCEED;
-    }
-    
-done:
-    if (mounted)
-        if(H5G_close(mounted)<0 && ret_value>=0)
-	    HDONE_ERROR(H5E_FILE, H5E_CANTCLOSEOBJ, FAIL, "can't close group")
-
-    FUNC_LEAVE_NOAPI(ret_value)
-}
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5F_mountpoint
- *
- * Purpose:	If ENT is a mount point then copy the entry for the root
- *		group of the mounted file into ENT.
- *
- * Return:	Non-negative on success/Negative on failure
- *
- * Programmer:	Robb Matzke
- *              Tuesday, October  6, 1998
- *
- * Modifications:
- *
- *      Pedro Vicente, <pvn@ncsa.uiuc.edu> 22 Aug 2002
- *      Added `id to name' support.
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5F_mountpoint(H5G_entry_t *find/*in,out*/)
-{
-    H5F_t	*parent = find->file;
-    unsigned	lt, rt, md=0;
-    int cmp;
-    H5G_entry_t	*ent = NULL;
-    herr_t ret_value=SUCCEED;   /* Return value */
-    
-    FUNC_ENTER_NOAPI(H5F_mountpoint, FAIL)
-
-    assert(find);
-
-    /*
-     * The loop is necessary because we might have file1 mounted at the root
-     * of file2, which is mounted somewhere in file3.
-     */
-    do {
-	/*
-	 * Use a binary search to find the potential mount point in the mount
-	 * table for the parent
-	 */
-	lt = 0;
-	rt = parent->mtab.nmounts;
-	cmp = -1;
-	while (lt<rt && cmp) {
-	    md = (lt+rt)/2;
-	    ent = H5G_entof(parent->mtab.child[md].group);
-	    cmp = H5F_addr_cmp(find->header, ent->header);
-	    if (cmp<0) {
-		rt = md;
-	    } else {
-		lt = md+1;
-	    }
-	}
-
-	/* Copy root info over to ENT */
-	if (0==cmp) {
-            /* Get the entry for the root group in the child's file */
-	    ent = H5G_entof(parent->mtab.child[md].file->shared->root_grp);
-
-            /* Don't lose the user path of the group when we copy the root group's entry */
-            if(H5G_ent_copy(find,ent,H5G_COPY_LIMITED)<0)
-                HGOTO_ERROR(H5E_FILE, H5E_CANTCOPY, FAIL, "unable to copy group entry")
-
-            /* Switch to child's file */
-	    parent = ent->file;
-	}
-    } while (!cmp);
-    
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-}
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5F_has_mount
- *
- * Purpose:	Check if a file has mounted files within it.
- *
- * Return:	Success:	TRUE/FALSE
- *		Failure:	Negative
- *
- * Programmer:	Quincey Koziol
- *              Thursday, January  2, 2002
- *
- * Modifications:
- *
- *-------------------------------------------------------------------------
- */
-htri_t
-H5F_has_mount(const H5F_t *file)
-{
-    htri_t ret_value;   /* Return value */
-    
-    FUNC_ENTER_NOAPI(H5F_has_mount, FAIL)
-
-    assert(file);
-
-    if(file->mtab.nmounts>0)
-        ret_value=TRUE;
-    else
-        ret_value=FALSE;
-    
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5F_has_mount() */
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5F_is_mount
- *
- * Purpose:	Check if a file is mounted within another file.
- *
- * Return:	Success:	TRUE/FALSE
- *		Failure:	Negative
- *
- * Programmer:	Quincey Koziol
- *              Thursday, January  2, 2002
- *
- * Modifications:
- *
- *-------------------------------------------------------------------------
- */
-htri_t
-H5F_is_mount(const H5F_t *file)
-{
-    htri_t ret_value;   /* Return value */
-    
-    FUNC_ENTER_NOAPI(H5F_is_mount, FAIL)
-
-    assert(file);
-
-    if(file->mtab.parent!=NULL)
-        ret_value=TRUE;
-    else
-        ret_value=FALSE;
-    
-done:
-    FUNC_LEAVE_NOAPI(ret_value)
-} /* end H5F_is_mount() */
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5Fmount
- *
- * Purpose:	Mount file CHILD_ID onto the group specified by LOC_ID and
- *		NAME using mount properties PLIST_ID.
- *
- * Return:	Non-negative on success/Negative on failure
- *
- * Programmer:	Robb Matzke
- *              Tuesday, October  6, 1998
- *
- * Modifications:
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5Fmount(hid_t loc_id, const char *name, hid_t child_id, hid_t plist_id)
-{
-    H5G_entry_t		*loc = NULL;
-    H5F_t		*child = NULL;
-    herr_t      ret_value=SUCCEED;       /* Return value */
-    
-    FUNC_ENTER_API(H5Fmount, FAIL)
-    H5TRACE4("e","isii",loc_id,name,child_id,plist_id);
-
-    /* Check arguments */
-    if (NULL==(loc=H5G_loc(loc_id)))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
-    if (!name || !*name)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name")
-    if (NULL==(child=H5I_object_verify(child_id,H5I_FILE)))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file")
-    if(H5P_DEFAULT == plist_id)
-        plist_id = H5P_MOUNT_DEFAULT;
-    else
-        if(TRUE != H5P_isa_class(plist_id, H5P_MOUNT))
-            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not property list")
-
-    /* Do the mount */
-    if (H5F_mount(loc, name, child, plist_id, H5AC_dxpl_id)<0)
-	HGOTO_ERROR(H5E_FILE, H5E_MOUNT, FAIL, "unable to mount file")
-
-done:
-    FUNC_LEAVE_API(ret_value)
-}
-
-
-/*-------------------------------------------------------------------------
- * Function:	H5Funmount
- *
- * Purpose:	Given a mount point, dissassociate the mount point's file
- *		from the file mounted there.  Do not close either file.
- *
- *		The mount point can either be the group in the parent or the
- *		root group of the mounted file (both groups have the same
- *		name).  If the mount point was opened before the mount then
- *		it's the group in the parent, but if it was opened after the
- *		mount then it's the root group of the child.
- *
- * Return:	Non-negative on success/Negative on failure
- *
- * Programmer:	Robb Matzke
- *              Tuesday, October  6, 1998
- *
- * Modifications:
- *
- *-------------------------------------------------------------------------
- */
-herr_t
-H5Funmount(hid_t loc_id, const char *name)
-{
-    H5G_entry_t		*loc = NULL;
-    herr_t      ret_value=SUCCEED;       /* Return value */
-    
-    FUNC_ENTER_API(H5Funmount, FAIL)
-    H5TRACE2("e","is",loc_id,name);
-
-    /* Check args */
-    if (NULL==(loc=H5G_loc(loc_id)))
-	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
-    if (!name || !*name)
-	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name")
-
-    /* Unmount */
-    if (H5F_unmount(loc, name, H5AC_dxpl_id)<0)
-	HGOTO_ERROR(H5E_FILE, H5E_MOUNT, FAIL, "unable to unmount file")
-
-done:
-    FUNC_LEAVE_API(ret_value)
-}
-
-
-/*-------------------------------------------------------------------------
  * Function:	H5Freopen
  *
  * Purpose:	Reopen a file.  The new file handle which is returned points
@@ -4145,7 +3025,8 @@ H5F_sizeof_size(const H5F_t *f)
  *		Added this header and removed unused ret_value variable.
  *-------------------------------------------------------------------------
  */
-unsigned H5F_sym_leaf_k(const H5F_t *f)
+unsigned
+H5F_sym_leaf_k(const H5F_t *f)
 {
     /* Use FUNC_ENTER_NOAPI_NOINIT_NOFUNC here to avoid performance issues */
     FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5F_sym_leaf_k)
@@ -4212,7 +3093,8 @@ H5F_Kvalue(const H5F_t *f, const H5B_class_t *type)
  *
  *-------------------------------------------------------------------------
  */
-size_t H5F_rdcc_nelmts(const H5F_t *f)
+size_t
+H5F_rdcc_nelmts(const H5F_t *f)
 {
     /* Use FUNC_ENTER_NOAPI_NOINIT_NOFUNC here to avoid performance issues */
     FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5F_rdcc_nelmts)
@@ -4244,7 +3126,8 @@ size_t H5F_rdcc_nelmts(const H5F_t *f)
  *
  *-------------------------------------------------------------------------
  */
-size_t H5F_rdcc_nbytes(const H5F_t *f)
+size_t
+H5F_rdcc_nbytes(const H5F_t *f)
 {
     /* Use FUNC_ENTER_NOAPI_NOINIT_NOFUNC here to avoid performance issues */
     FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5F_rdcc_nbytes)
@@ -4276,7 +3159,8 @@ size_t H5F_rdcc_nbytes(const H5F_t *f)
  *
  *-------------------------------------------------------------------------
  */
-double H5F_rdcc_w0(const H5F_t *f)
+double
+H5F_rdcc_w0(const H5F_t *f)
 {
     /* Use FUNC_ENTER_NOAPI_NOINIT_NOFUNC here to avoid performance issues */
     FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5F_rdcc_w0)
@@ -4304,7 +3188,8 @@ double H5F_rdcc_w0(const H5F_t *f)
  *
  *-------------------------------------------------------------------------
  */
-hbool_t H5F_has_feature(const H5F_t *f, unsigned feature)
+hbool_t
+H5F_has_feature(const H5F_t *f, unsigned feature)
 {
     /* Use FUNC_ENTER_NOAPI_NOINIT_NOFUNC here to avoid performance issues */
     FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5F_has_feature)
diff --git a/src/H5FDfamily.c b/src/H5FDfamily.c
index bac0826..73cb11c 100644
--- a/src/H5FDfamily.c
+++ b/src/H5FDfamily.c
@@ -576,12 +576,12 @@ done:
  *-------------------------------------------------------------------------
  */
 static hsize_t
-H5FD_family_sb_size(H5FD_t *_file)
+H5FD_family_sb_size(H5FD_t UNUSED *_file)
 {
     H5FD_family_t	*file = (H5FD_family_t*)_file;
     hsize_t		ret_value = 0; /*size of header*/
 
-    FUNC_ENTER_NOAPI(H5FD_family_sb_size, FAIL)
+    FUNC_ENTER_NOAPI(H5FD_family_sb_size, UFAIL)
 
     /* 8 bytes field for the size of member file size field should be 
      * enough for now. */
@@ -657,7 +657,7 @@ done:
  *-------------------------------------------------------------------------
  */
 static herr_t
-H5FD_family_sb_decode(H5FD_t *_file, const char *name, const unsigned char *buf)
+H5FD_family_sb_decode(H5FD_t *_file, const char UNUSED *name, const unsigned char *buf)
 {
     H5FD_family_t	*file = (H5FD_family_t*)_file;
     uint64_t            msize = 0;
@@ -685,7 +685,7 @@ H5FD_family_sb_decode(H5FD_t *_file, const char *name, const unsigned char *buf)
 
     /* Check if member size from file access property is correct */
     if(msize != file->pmem_size) {
-        sprintf(err_msg, "family member size should be %lu", msize);
+        sprintf(err_msg, "family member size should be %lu", (unsigned long)msize);
         HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, err_msg)
     }
 
diff --git a/src/H5Fmount.c b/src/H5Fmount.c
new file mode 100644
index 0000000..73a450d
--- /dev/null
+++ b/src/H5Fmount.c
@@ -0,0 +1,713 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by the Board of Trustees of the University of Illinois.         *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the files COPYING and Copyright.html.  COPYING can be found at the root   *
+ * of the source code distribution tree; Copyright.html can be found at the  *
+ * root level of an installed copy of the electronic HDF5 document set and   *
+ * is linked from the top-level documents page.  It can also be found at     *
+ * http://hdf.ncsa.uiuc.edu/HDF5/doc/Copyright.html.  If you do not have     *
+ * access to either file, you may request a copy from hdfhelp@ncsa.uiuc.edu. *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#define H5F_PACKAGE		/*suppress error about including H5Fpkg	  */
+
+/* Interface initialization */
+#define H5_INTERFACE_INIT_FUNC	H5F_init_mount_interface
+
+
+/* Packages needed by this file... */
+#include "H5private.h"		/* Generic Functions			*/
+#include "H5Eprivate.h"		/* Error handling		  	*/
+#include "H5Fpkg.h"             /* File access				*/
+#include "H5Gprivate.h"		/* Groups				*/
+#include "H5Iprivate.h"		/* IDs			  		*/
+#include "H5Pprivate.h"		/* Property lists			*/
+#include "H5MMprivate.h"	/* Memory management			*/
+
+/* PRIVATE PROTOTYPES */
+
+
+/*--------------------------------------------------------------------------
+NAME
+   H5F_init_mount_interface -- Initialize interface-specific information
+USAGE
+    herr_t H5T_init_mount_interface()
+   
+RETURNS
+    Non-negative on success/Negative on failure
+DESCRIPTION
+    Initializes any interface-specific data or routines.  (Just calls
+    H5F_init_iterface currently).
+
+--------------------------------------------------------------------------*/
+static herr_t
+H5F_init_mount_interface(void)
+{
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5F_init_mount_interface)
+
+    FUNC_LEAVE_NOAPI(H5F_init())
+} /* H5F_init_mount_interface() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_close_mounts
+ *
+ * Purpose:	Close all mounts for a given file
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Quincey Koziol
+ *              Saturday, July  2, 2005
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5F_close_mounts(H5F_t *f)
+{
+    unsigned u;                 /* Local index */
+    herr_t ret_value=SUCCEED;   /* Return value */
+    
+    FUNC_ENTER_NOAPI(H5F_close_mounts, FAIL)
+
+    HDassert(f);
+
+    /* Unmount all child files */
+    for (u = 0; u < f->mtab.nmounts; u++) {
+        f->mtab.child[u].file->mtab.parent = NULL;
+        if(H5G_close(f->mtab.child[u].group) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEOBJ, FAIL, "can't close child group")
+        if(H5F_close(f->mtab.child[u].file) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL, "can't close child file")
+    } /* end if */
+    f->mtab.nmounts = 0;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5F_close_mounts() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_term_unmount_cb 
+ *
+ * Purpose:	H5F_term_interface' callback function.  This routine
+ *              unmounts child files from files that are in the "closing"
+ *              state.
+ *
+ * Programmer:  Quincey Koziol
+ *              Thursday, Jun 30, 2005
+ *
+ * Modification:
+ *
+ *-------------------------------------------------------------------------
+ */
+int
+H5F_term_unmount_cb(void *obj_ptr, hid_t obj_id, void UNUSED *key)
+{
+    H5F_t *f = (H5F_t *)obj_ptr;    /* Alias for search info */
+    int      ret_value = FALSE;     /* Return value */
+ 
+    FUNC_ENTER_NOAPI_NOINIT(H5F_term_unmount_cb)
+
+    assert(f);
+
+    if(f->mtab.nmounts) {
+        /* Unmount all child files */
+        if(H5F_close_mounts(f) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL, "can't unmount child file")
+
+        /* Decrement reference count for file */
+        H5I_dec_ref(obj_id);
+    } /* end if */
+    else
+        HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL, "no files to unmount")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value);
+} /* end H5F_term_unmount_cb() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_mount
+ *
+ * Purpose:	Mount file CHILD onto the group specified by LOC and NAME,
+ *		using mount properties in PLIST.  CHILD must not already be
+ *		mouted and must not be a mount ancestor of the mount-point.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Robb Matzke
+ *              Tuesday, October  6, 1998
+ *
+ * Modifications:
+ *
+ * 	Robb Matzke, 1998-10-14
+ *	The reference count for the mounted H5F_t is incremented.
+ *
+ *      Pedro Vicente, <pvn@ncsa.uiuc.edu> 22 Aug 2002
+ *      Added `id to name' support.
+ *
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5F_mount(H5G_entry_t *loc, const char *name, H5F_t *child,
+	  hid_t UNUSED plist_id, hid_t dxpl_id)
+{
+    H5G_t	*mount_point = NULL;	/*mount point group		*/
+    H5G_entry_t	*mp_ent = NULL;		/*mount point symbol table entry*/
+    H5F_t	*ancestor = NULL;	/*ancestor files		*/
+    H5F_t	*parent = NULL;		/*file containing mount point	*/
+    unsigned	lt, rt, md;		/*binary search indices		*/
+    int		cmp;			/*binary search comparison value*/
+    H5G_entry_t	*ent = NULL;		/*temporary symbol table entry	*/
+    H5G_entry_t  mp_open_ent;     /* entry of moint point to be opened */
+    H5RS_str_t  *name_r;                /* Ref-counted version of name */
+    herr_t	ret_value = SUCCEED;	/*return value			*/
+    
+    FUNC_ENTER_NOAPI_NOINIT(H5F_mount)
+
+    assert(loc);
+    assert(name && *name);
+    assert(child);
+    assert(TRUE==H5P_isa_class(plist_id,H5P_MOUNT));
+
+    /*
+     * Check that the child isn't mounted, that the mount point exists, and
+     * that the mount wouldn't introduce a cycle in the mount tree.
+     */
+    if (child->mtab.parent)
+        HGOTO_ERROR(H5E_FILE, H5E_MOUNT, FAIL, "file is already mounted")
+    if (H5G_find(loc, name, NULL, &mp_open_ent/*out*/, H5AC_dxpl_id) < 0)
+        HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "group not found")
+    if (NULL==(mount_point=H5G_open(&mp_open_ent, dxpl_id)))
+        HGOTO_ERROR(H5E_FILE, H5E_MOUNT, FAIL, "mount point not found")
+
+    parent = H5G_fileof(mount_point);
+    mp_ent = H5G_entof(mount_point);
+    for (ancestor=parent; ancestor; ancestor=ancestor->mtab.parent) {
+	if (ancestor==child)
+	    HGOTO_ERROR(H5E_FILE, H5E_MOUNT, FAIL, "mount would introduce a cycle")
+    }
+    
+    /*
+     * Use a binary search to locate the position that the child should be
+     * inserted into the parent mount table.  At the end of this paragraph
+     * `md' will be the index where the child should be inserted.
+     */
+    lt = md = 0;
+    rt=parent->mtab.nmounts;
+    cmp = -1;
+    while (lt<rt && cmp) {
+	md = (lt+rt)/2;
+	ent = H5G_entof(parent->mtab.child[md].group);
+	cmp = H5F_addr_cmp(mp_ent->header, ent->header);
+	if (cmp<0) {
+	    rt = md;
+	} else if (cmp>0) {
+	    lt = md+1;
+	}
+    }
+    if (cmp>0)
+        md++;
+    if (!cmp)
+	HGOTO_ERROR(H5E_FILE, H5E_MOUNT, FAIL, "mount point is already in use")
+    
+    /* Make room in the table */
+    if (parent->mtab.nmounts>=parent->mtab.nalloc) {
+	unsigned n = MAX(16, 2*parent->mtab.nalloc);
+	H5F_mount_t *x = H5MM_realloc(parent->mtab.child,
+				      n*sizeof(parent->mtab.child[0]));
+	if (!x)
+	    HGOTO_ERROR(H5E_RESOURCE, H5E_NOSPACE, FAIL, "memory allocation failed for mount table")
+	parent->mtab.child = x;
+	parent->mtab.nalloc = n;
+    }
+
+    /* Insert into table */
+    HDmemmove(parent->mtab.child+md+1, parent->mtab.child+md,
+        (parent->mtab.nmounts-md)*sizeof(parent->mtab.child[0]));
+    parent->mtab.nmounts++;
+    parent->mtab.child[md].group = mount_point;
+    parent->mtab.child[md].file = child;
+    child->mtab.parent = parent;
+    child->nrefs++;
+
+    /* Search the open IDs and replace names for mount operation */
+    /* We pass H5G_UNKNOWN as object type; search all IDs */
+    name_r=H5RS_wrap(name);
+    assert(name_r);
+    if (H5G_replace_name( H5G_UNKNOWN, loc, name_r, NULL, NULL, NULL, OP_MOUNT )<0)
+	HGOTO_ERROR(H5E_FILE, H5E_MOUNT, FAIL, "unable to replace name")
+    if(H5RS_decr(name_r)<0)
+	HGOTO_ERROR(H5E_FILE, H5E_CANTDEC, FAIL, "unable to decrement name string")
+
+done:
+    if (ret_value<0 && mount_point)
+	if(H5G_close(mount_point)<0)
+            HDONE_ERROR(H5E_FILE, H5E_CANTCLOSEOBJ, FAIL, "unable to close mounted group")
+
+    FUNC_LEAVE_NOAPI(ret_value)
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_unmount
+ *
+ * Purpose:	Unmount the child which is mounted at the group specified by
+ *		LOC and NAME or fail if nothing is mounted there.  Neither
+ *		file is closed.
+ *
+ *		Because the mount point is specified by name and opened as a
+ *		group, the H5G_namei() will resolve it to the root of the
+ *		mounted file, not the group where the file is mounted.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Robb Matzke
+ *              Tuesday, October  6, 1998
+ *
+ * Modifications:
+ *
+ *      Robb Matzke, 1998-10-14
+ *      The ref count for the child is decremented by calling H5F_close().
+ *
+ *      Pedro Vicente, <pvn@ncsa.uiuc.edu> 22 Aug 2002
+ *      Added `id to name' support.
+ * 
+ *-------------------------------------------------------------------------
+ */
+static herr_t
+H5F_unmount(H5G_entry_t *loc, const char *name, hid_t dxpl_id)
+{
+    H5G_t	*mounted = NULL;	/*mount point group		*/
+    H5G_entry_t	*mnt_ent = NULL;	/*mounted symbol table entry	*/
+    H5F_t	*child = NULL;		/*mounted file			*/
+    H5F_t	*parent = NULL;		/*file where mounted		*/
+    H5G_entry_t	*ent = NULL;		/*temporary symbol table entry	*/
+    H5G_entry_t mnt_open_ent;       /* entry used to open mount point*/
+    herr_t	ret_value = FAIL;	/*return value			*/
+    unsigned	i;			/*coutners			*/
+    unsigned	lt, rt, md=0;	        /*binary search indices		*/
+    int 	cmp;		        /*binary search comparison value*/
+    
+    FUNC_ENTER_NOAPI_NOINIT(H5F_unmount)
+
+    assert(loc);
+    assert(name && *name);
+
+    /*
+     * Get the mount point, or more precisely the root of the mounted file.
+     * If we get the root group and the file has a parent in the mount tree,
+     * then we must have found the mount point.
+     */
+    if (H5G_find(loc, name, NULL, &mnt_open_ent/*out*/, H5AC_dxpl_id) < 0)
+        HGOTO_ERROR(H5E_SYM, H5E_NOTFOUND, FAIL, "group not found")
+    if (NULL==(mounted=H5G_open(&mnt_open_ent, dxpl_id)))
+        HGOTO_ERROR(H5E_FILE, H5E_MOUNT, FAIL, "mount point not found")
+    child = H5G_fileof(mounted);
+    mnt_ent = H5G_entof(mounted);
+    ent = H5G_entof(child->shared->root_grp);
+
+    if (child->mtab.parent &&
+	H5F_addr_eq(mnt_ent->header, ent->header)) {
+	/*
+	 * We've been given the root group of the child.  We do a reverse
+	 * lookup in the parent's mount table to find the correct entry.
+	 */
+	parent = child->mtab.parent;
+	for (i=0; i<parent->mtab.nmounts; i++) {
+	    if (parent->mtab.child[i].file==child) {
+                /* Search the open IDs replace names to reflect unmount operation */
+                if (H5G_replace_name( H5G_UNKNOWN, mnt_ent, mnt_ent->user_path_r, NULL, NULL, NULL, OP_UNMOUNT )<0)
+                    HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to replace name ")
+
+		/* Unmount the child */
+		parent->mtab.nmounts -= 1;
+		if(H5G_close(parent->mtab.child[i].group)<0)
+                    HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEOBJ, FAIL, "unable to close unmounted group")
+		child->mtab.parent = NULL;
+		if(H5F_close(child)<0)
+                    HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL, "unable to close unmounted file")
+		HDmemmove(parent->mtab.child+i, parent->mtab.child+i+1,
+                    (parent->mtab.nmounts-i)* sizeof(parent->mtab.child[0]));
+		ret_value = SUCCEED;
+	    }
+	}
+	assert(ret_value>=0);
+	
+    } else {
+	/*
+	 * We've been given the mount point in the parent.  We use a binary
+	 * search in the parent to locate the mounted file, if any.
+	 */
+	parent = child; /*we guessed wrong*/
+	lt = 0;
+        rt = parent->mtab.nmounts;
+	cmp = -1;
+	while (lt<rt && cmp) {
+	    md = (lt+rt)/2;
+	    ent = H5G_entof(parent->mtab.child[md].group);
+	    cmp = H5F_addr_cmp(mnt_ent->header, ent->header);
+	    if (cmp<0) {
+		rt = md;
+	    } else {
+		lt = md+1;
+	    }
+	}
+	if (cmp)
+	    HGOTO_ERROR(H5E_FILE, H5E_MOUNT, FAIL, "not a mount point")
+
+	/* Unmount the child */
+	parent->mtab.nmounts -= 1;
+	if(H5G_close(parent->mtab.child[md].group)<0)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEOBJ, FAIL, "unable to close unmounted group")
+	parent->mtab.child[md].file->mtab.parent = NULL;
+	if(H5F_close(parent->mtab.child[md].file)<0)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL, "unable to close unmounted file")
+	HDmemmove(parent->mtab.child+md, parent->mtab.child+md+1,
+            (parent->mtab.nmounts-md)*sizeof(parent->mtab.child[0]));
+	ret_value = SUCCEED;
+    }
+    
+done:
+    if (mounted)
+        if(H5G_close(mounted)<0 && ret_value>=0)
+	    HDONE_ERROR(H5E_FILE, H5E_CANTCLOSEOBJ, FAIL, "can't close group")
+
+    FUNC_LEAVE_NOAPI(ret_value)
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_mountpoint
+ *
+ * Purpose:	If ENT is a mount point then copy the entry for the root
+ *		group of the mounted file into ENT.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Robb Matzke
+ *              Tuesday, October  6, 1998
+ *
+ * Modifications:
+ *
+ *      Pedro Vicente, <pvn@ncsa.uiuc.edu> 22 Aug 2002
+ *      Added `id to name' support.
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5F_mountpoint(H5G_entry_t *find/*in,out*/)
+{
+    H5F_t	*parent = find->file;
+    unsigned	lt, rt, md=0;
+    int cmp;
+    H5G_entry_t	*ent = NULL;
+    herr_t ret_value=SUCCEED;   /* Return value */
+    
+    FUNC_ENTER_NOAPI(H5F_mountpoint, FAIL)
+
+    assert(find);
+
+    /*
+     * The loop is necessary because we might have file1 mounted at the root
+     * of file2, which is mounted somewhere in file3.
+     */
+    do {
+	/*
+	 * Use a binary search to find the potential mount point in the mount
+	 * table for the parent
+	 */
+	lt = 0;
+	rt = parent->mtab.nmounts;
+	cmp = -1;
+	while (lt<rt && cmp) {
+	    md = (lt+rt)/2;
+	    ent = H5G_entof(parent->mtab.child[md].group);
+	    cmp = H5F_addr_cmp(find->header, ent->header);
+	    if (cmp<0) {
+		rt = md;
+	    } else {
+		lt = md+1;
+	    }
+	}
+
+	/* Copy root info over to ENT */
+	if (0==cmp) {
+            /* Get the entry for the root group in the child's file */
+	    ent = H5G_entof(parent->mtab.child[md].file->shared->root_grp);
+
+            /* Don't lose the user path of the group when we copy the root group's entry */
+            if(H5G_ent_copy(find,ent,H5G_COPY_LIMITED)<0)
+                HGOTO_ERROR(H5E_FILE, H5E_CANTCOPY, FAIL, "unable to copy group entry")
+
+            /* Switch to child's file */
+	    parent = ent->file;
+	}
+    } while (!cmp);
+    
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_has_mount
+ *
+ * Purpose:	Check if a file has mounted files within it.
+ *
+ * Return:	Success:	TRUE/FALSE
+ *		Failure:	Negative
+ *
+ * Programmer:	Quincey Koziol
+ *              Thursday, January  2, 2002
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+htri_t
+H5F_has_mount(const H5F_t *file)
+{
+    htri_t ret_value;   /* Return value */
+    
+    FUNC_ENTER_NOAPI(H5F_has_mount, FAIL)
+
+    assert(file);
+
+    if(file->mtab.nmounts>0)
+        ret_value=TRUE;
+    else
+        ret_value=FALSE;
+    
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5F_has_mount() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_is_mount
+ *
+ * Purpose:	Check if a file is mounted within another file.
+ *
+ * Return:	Success:	TRUE/FALSE
+ *		Failure:	Negative
+ *
+ * Programmer:	Quincey Koziol
+ *              Thursday, January  2, 2002
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+htri_t
+H5F_is_mount(const H5F_t *file)
+{
+    htri_t ret_value;   /* Return value */
+    
+    FUNC_ENTER_NOAPI(H5F_is_mount, FAIL)
+
+    assert(file);
+
+    if(file->mtab.parent!=NULL)
+        ret_value=TRUE;
+    else
+        ret_value=FALSE;
+    
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5F_is_mount() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Fmount
+ *
+ * Purpose:	Mount file CHILD_ID onto the group specified by LOC_ID and
+ *		NAME using mount properties PLIST_ID.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Robb Matzke
+ *              Tuesday, October  6, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Fmount(hid_t loc_id, const char *name, hid_t child_id, hid_t plist_id)
+{
+    H5G_entry_t		*loc = NULL;
+    H5F_t		*child = NULL;
+    herr_t      ret_value=SUCCEED;       /* Return value */
+    
+    FUNC_ENTER_API(H5Fmount, FAIL)
+    H5TRACE4("e","isii",loc_id,name,child_id,plist_id);
+
+    /* Check arguments */
+    if (NULL==(loc=H5G_loc(loc_id)))
+	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
+    if (!name || !*name)
+	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name")
+    if (NULL==(child=H5I_object_verify(child_id,H5I_FILE)))
+	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a file")
+    if(H5P_DEFAULT == plist_id)
+        plist_id = H5P_MOUNT_DEFAULT;
+    else
+        if(TRUE != H5P_isa_class(plist_id, H5P_MOUNT))
+            HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not property list")
+
+    /* Do the mount */
+    if (H5F_mount(loc, name, child, plist_id, H5AC_dxpl_id)<0)
+	HGOTO_ERROR(H5E_FILE, H5E_MOUNT, FAIL, "unable to mount file")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5Funmount
+ *
+ * Purpose:	Given a mount point, dissassociate the mount point's file
+ *		from the file mounted there.  Do not close either file.
+ *
+ *		The mount point can either be the group in the parent or the
+ *		root group of the mounted file (both groups have the same
+ *		name).  If the mount point was opened before the mount then
+ *		it's the group in the parent, but if it was opened after the
+ *		mount then it's the root group of the child.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Robb Matzke
+ *              Tuesday, October  6, 1998
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5Funmount(hid_t loc_id, const char *name)
+{
+    H5G_entry_t		*loc = NULL;
+    herr_t      ret_value=SUCCEED;       /* Return value */
+    
+    FUNC_ENTER_API(H5Funmount, FAIL)
+    H5TRACE2("e","is",loc_id,name);
+
+    /* Check args */
+    if (NULL==(loc=H5G_loc(loc_id)))
+	HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a location")
+    if (!name || !*name)
+	HGOTO_ERROR(H5E_ARGS, H5E_BADVALUE, FAIL, "no name")
+
+    /* Unmount */
+    if (H5F_unmount(loc, name, H5AC_dxpl_id)<0)
+	HGOTO_ERROR(H5E_FILE, H5E_MOUNT, FAIL, "unable to unmount file")
+
+done:
+    FUNC_LEAVE_API(ret_value)
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_check_mounts_recurse
+ *
+ * Purpose:	Helper routine for checking for file mounting hierarchies to
+ *              close.
+ *
+ * Return:	TRUE if entire hierarchy can be closed / FALSE otherwise
+ *
+ * Programmer:	Quincey Koziol
+ *              Saturday, July  2, 2005
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+static hbool_t
+H5F_check_mounts_recurse(H5F_t *f)
+{
+    hbool_t ret_value;          /* Return value */
+
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5F_check_mounts_recurse)
+
+    /* Check if this file is closing and if the only objects left open are
+     * the mount points */
+    if(f->closing && f->nopen_objs == f->mtab.nmounts) {
+        unsigned u;
+
+        /* Iterate over files mounted in this file and check if all can be closed */
+        for(u = 0; u < f->mtab.nmounts; u++) {
+            if(H5G_get_shared_count(f->mtab.child[u].group) > 1
+                    || !H5F_check_mounts_recurse(f->mtab.child[u].file))
+                HGOTO_DONE(FALSE)
+        } /* end for */
+    } /* end if */
+
+    ret_value = TRUE;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5F_check_mounts_recurse() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:	H5F_check_mounts
+ *
+ * Purpose:	Check for file mounting hierarchies that have been created
+ *              and that now are composed completely of files that are closing
+ *              and have no more open objects in them.
+ *
+ *              When such a mounting hierarchy is detected, unmount and close
+ *              all the files involved.
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Quincey Koziol
+ *              Saturday, July  2, 2005
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5F_check_mounts(H5F_t *f)
+{
+    herr_t      ret_value=SUCCEED;       /* Return value */
+    
+    FUNC_ENTER_NOAPI(H5F_check_mounts, FAIL)
+
+    /* Only try to close files for files involved in a mounting hierarchy */
+    if(f->mtab.parent || f->mtab.nmounts) {
+        H5F_t *top = f;         /* Pointer to the top file in the hierarchy */
+
+        /* Find the top file in the mounting hierarchy */
+        while(top->mtab.parent) {
+            /* Get out early if we detect that this hierarchy won't close */
+            if(top->nopen_objs != top->mtab.nmounts || !top->closing)
+                HGOTO_DONE(SUCCEED)
+
+            /* Advance toward the top of the hierarchy */
+            top = top->mtab.parent;
+        } /* end while */
+
+        /* Check for closing the hierarchy */
+        if(H5F_check_mounts_recurse(top)) {
+            /* Unmount all child files */
+            if(H5F_close_mounts(top) < 0)
+                HGOTO_ERROR(H5E_FILE, H5E_CANTCLOSEFILE, FAIL, "can't unmount child file")
+
+            H5I_dec_ref(top->closing);
+        } /* end if */
+    } /* end if */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5F_check_mounts() */
+
diff --git a/src/H5Fpkg.h b/src/H5Fpkg.h
index c7b9e95..363c1e6 100644
--- a/src/H5Fpkg.h
+++ b/src/H5Fpkg.h
@@ -163,7 +163,21 @@ union H5D_storage_t;
 #ifdef NOT_YET
 H5_DLL void H5F_encode_length_unusual(const H5F_t *f, uint8_t **p, uint8_t *l);
 #endif /* NOT_YET */
+
+/* General routines */
+H5_DLL herr_t H5F_close(H5F_t *f);
+H5_DLL haddr_t H5F_locate_signature(H5FD_t *file, hid_t dxpl_id);
+
+/* File mount related routines */
 H5_DLL herr_t H5F_mountpoint(struct H5G_entry_t *find/*in,out*/);
+H5_DLL herr_t H5F_close_mounts(H5F_t *f);
+H5_DLL int H5F_term_unmount_cb(void *obj_ptr, hid_t obj_id, void *key);
+H5_DLL herr_t H5F_check_mounts(H5F_t *f);
+
+/* Superblock related routines */
+H5_DLL hsize_t H5F_init_superblock(const H5F_t *f, hid_t dxpl_id);
+H5_DLL herr_t H5F_write_superblock(H5F_t *f, hid_t dxpl_id, uint8_t *buf);
+H5_DLL herr_t H5F_read_superblock(H5F_t *f, hid_t dxpl_id, H5G_entry_t *root_ent, haddr_t addr, uint8_t *buf, size_t buf_size);
 
 #endif
 
diff --git a/src/H5Fsuper.c b/src/H5Fsuper.c
new file mode 100644
index 0000000..4cb1646
--- /dev/null
+++ b/src/H5Fsuper.c
@@ -0,0 +1,646 @@
+/* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
+ * Copyright by the Board of Trustees of the University of Illinois.         *
+ * All rights reserved.                                                      *
+ *                                                                           *
+ * This file is part of HDF5.  The full HDF5 copyright notice, including     *
+ * terms governing use, modification, and redistribution, is contained in    *
+ * the files COPYING and Copyright.html.  COPYING can be found at the root   *
+ * of the source code distribution tree; Copyright.html can be found at the  *
+ * root level of an installed copy of the electronic HDF5 document set and   *
+ * is linked from the top-level documents page.  It can also be found at     *
+ * http://hdf.ncsa.uiuc.edu/HDF5/doc/Copyright.html.  If you do not have     *
+ * access to either file, you may request a copy from hdfhelp@ncsa.uiuc.edu. *
+ * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
+
+#define H5F_PACKAGE		/*suppress error about including H5Fpkg	  */
+
+/* Interface initialization */
+#define H5_INTERFACE_INIT_FUNC	H5F_init_super_interface
+
+
+/* Packages needed by this file... */
+#include "H5private.h"		/* Generic Functions			*/
+#include "H5Eprivate.h"		/* Error handling		  	*/
+#include "H5Fpkg.h"             /* File access				*/
+#include "H5FDprivate.h"	/* File drivers				*/
+#include "H5Iprivate.h"		/* IDs			  		*/
+#include "H5Pprivate.h"		/* Property lists			*/
+
+/* PRIVATE PROTOTYPES */
+
+
+/*--------------------------------------------------------------------------
+NAME
+   H5F_init_super_interface -- Initialize interface-specific information
+USAGE
+    herr_t H5T_init_super_interface()
+   
+RETURNS
+    Non-negative on success/Negative on failure
+DESCRIPTION
+    Initializes any interface-specific data or routines.  (Just calls
+    H5F_init_iterface currently).
+
+--------------------------------------------------------------------------*/
+static herr_t
+H5F_init_super_interface(void)
+{
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5F_init_super_interface)
+
+    FUNC_LEAVE_NOAPI(H5F_init())
+} /* H5F_init_super_interface() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5F_read_superblock
+ *
+ * Purpose:     Reads the superblock from the file or from the BUF. If
+ *              ADDR is a valid address, then it reads it from the file.
+ *              If not, then BUF must be non-NULL for it to read from the
+ *              BUF.
+ *
+ * Return:      Success:        SUCCEED
+ *              Failure:        FAIL
+ *
+ * Programmer:  Bill Wendling
+ *              wendling@ncsa.uiuc.edu
+ *              Sept 12, 2003
+ *
+ * Modifications:
+ *              Raymond Lu
+ *              May 24, 2005
+ *              Started to check if driver(only family and multi drivers) 
+ *              matches driver information saved in the superblock.  Wrong
+ *              driver will result in a failure.
+ * 
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5F_read_superblock(H5F_t *f, hid_t dxpl_id, H5G_entry_t *root_ent, haddr_t addr, uint8_t *buf, size_t buf_size)
+{
+    haddr_t             stored_eoa;         /*relative end-of-addr in file  */
+    haddr_t             eof;                /*end of file address           */
+    uint8_t            *q;                  /*ptr into temp I/O buffer      */
+    size_t              sizeof_addr = 0;
+    size_t              sizeof_size = 0;
+    const size_t        fixed_size = 24;    /*fixed sizeof superblock       */
+    unsigned            sym_leaf_k = 0;
+    size_t              variable_size;      /*variable sizeof superblock    */
+    unsigned            btree_k[H5B_NUM_BTREE_ID];  /* B-tree internal node 'K' values */
+    H5F_file_t         *shared = NULL;      /* shared part of `file'        */
+    H5FD_t             *lf = NULL;          /* file driver part of `shared' */
+    uint8_t            *p;                  /* Temporary pointer into encoding buffers */
+    uint8_t            *start_p;            /* Start of encoding buffers    */
+    unsigned            i;                  /* Index variable               */
+    unsigned            chksum;             /* Checksum temporary variable  */
+    size_t              driver_size;        /* Size of driver info block, in bytes */
+    char                driver_name[9];     /* Name of driver, for driver info block */
+    unsigned            super_vers;         /* Super block version          */
+    unsigned            freespace_vers;     /* Freespace info version       */
+    unsigned            obj_dir_vers;       /* Object header info version   */
+    unsigned            share_head_vers;    /* Shared header info version   */
+    uint8_t             sbuf[H5F_SUPERBLOCK_SIZE];     /* Local buffer                 */
+    H5P_genplist_t     *c_plist;            /* File creation property list  */
+    herr_t              ret_value = SUCCEED;
+
+    /* Decoding */
+    FUNC_ENTER_NOAPI(H5F_read_superblock, FAIL)
+
+    /* Short cuts */
+    shared = f->shared;
+    lf = shared->lf;
+
+    /* Get the shared file creation property list */
+    if (NULL == (c_plist = H5I_object(shared->fcpl_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "can't get property list")
+
+    /* Read the superblock if it hasn't been read before. */
+    if (addr == HADDR_UNDEF) {
+        if (HADDR_UNDEF == (shared->super_addr=H5F_locate_signature(lf,dxpl_id)))
+            HGOTO_ERROR(H5E_FILE, H5E_NOTHDF5, FAIL, "unable to find file signature")
+    } else {
+        shared->super_addr = addr;
+    }
+
+    if (!buf) {
+        start_p = p = sbuf;
+        buf_size=sizeof(sbuf);
+
+        if (H5FD_set_eoa(lf, shared->super_addr + fixed_size) < 0 ||
+                H5FD_read(lf, H5FD_MEM_SUPER, dxpl_id, shared->super_addr, fixed_size, p) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_READERROR, FAIL, "unable to read superblock")
+    } else {
+        start_p = p = buf;
+    }
+
+    /* Signature, already checked */
+    p += H5F_SIGNATURE_LEN;
+
+    /* Superblock version */
+    super_vers = *p++;
+    if (super_vers > HDF5_SUPERBLOCK_VERSION_MAX) 
+        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "bad superblock version number")
+    if (H5P_set(c_plist, H5F_CRT_SUPER_VERS_NAME, &super_vers) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "unable to set superblock version")
+
+    /* Freespace version */
+    freespace_vers = *p++;
+    if (HDF5_FREESPACE_VERSION != freespace_vers) 
+        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "bad free space version number")
+    if (H5P_set(c_plist, H5F_CRT_FREESPACE_VERS_NAME, &freespace_vers) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "unable to free space version")
+
+    /* Root group version number */
+    obj_dir_vers = *p++;
+    if (HDF5_OBJECTDIR_VERSION != obj_dir_vers) 
+        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "bad object directory version number")
+    if (H5P_set(c_plist, H5F_CRT_OBJ_DIR_VERS_NAME, &obj_dir_vers) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "unable to set object directory version")
+
+    /* Skip over reserved byte */
+    p++;
+
+    /* Shared header version number */
+    share_head_vers = *p++;
+    if (HDF5_SHAREDHEADER_VERSION != share_head_vers) 
+        HGOTO_ERROR(H5E_FILE, H5E_BADVALUE, FAIL, "bad shared-header format version number")
+    if (H5P_set(c_plist, H5F_CRT_SHARE_HEAD_VERS_NAME, &share_head_vers) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "unable to set shared-header format version")
+
+    /* 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, FAIL, "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, FAIL, "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, FAIL, "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, FAIL, "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, FAIL, "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, FAIL, "unable to set rank for symbol table leaf nodes")
+    shared->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, FAIL, "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, FAIL, "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 consistency flags. Not really used yet */
+    UINT32DECODE(p, shared->consist_flags);
+    assert(((size_t)(p - start_p)) == fixed_size);
+
+    /* Decode the variable-length part of the superblock... */
+    variable_size = (super_vers>0 ? 4 : 0) +    /* Potential indexed storage B-tree internal 'K' value */
+                    H5F_SIZEOF_ADDR(f) +        /*base addr*/
+                    H5F_SIZEOF_ADDR(f) +        /*global free list*/
+                    H5F_SIZEOF_ADDR(f) +        /*end-of-address*/
+                    H5F_SIZEOF_ADDR(f) +        /*reserved address*/
+                    H5G_SIZEOF_ENTRY(f);        /*root group ptr*/
+    assert(fixed_size + variable_size <= buf_size);
+
+    /* The buffer (buf) is either passed in or the "local_buf" variable now */
+    if(!buf) {
+        if (H5FD_set_eoa(lf, shared->super_addr + fixed_size+variable_size) < 0 ||
+                H5FD_read(lf, H5FD_MEM_SUPER, dxpl_id, shared->super_addr + fixed_size,
+                          variable_size, p) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "unable to read superblock")
+    } /* end if */
+
+    /*
+     * If the superblock version # is greater than 0, read in the indexed
+     * storage B-tree internal 'K' value
+     */
+    if (super_vers > 0) {
+        UINT16DECODE(p, btree_k[H5B_ISTORE_ID]);
+        p += 2;   /* reserved */
+    }
+    else
+        btree_k[H5B_ISTORE_ID] = HDF5_BTREE_ISTORE_IK_DEF;
+
+    /* 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, FAIL, "unable to set rank for btree internal nodes")
+    HDmemcpy(shared->btree_k, btree_k, sizeof(unsigned) * (size_t)H5B_NUM_BTREE_ID);    /* Keep a local copy also */
+
+    H5F_addr_decode(f, (const uint8_t **)&p, &shared->base_addr/*out*/);
+    H5F_addr_decode(f, (const uint8_t **)&p, &shared->freespace_addr/*out*/);
+    H5F_addr_decode(f, (const uint8_t **)&p, &stored_eoa/*out*/);
+    H5F_addr_decode(f, (const uint8_t **)&p, &shared->driver_addr/*out*/);
+    if (H5G_ent_decode(f, (const uint8_t **)&p, root_ent/*out*/) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "unable to read root symbol entry")
+
+    /*
+     * Check if superblock address is different from base address and
+     * adjust base address and "end of address" address if so.
+     */
+    if (!H5F_addr_eq(shared->super_addr,shared->base_addr)) {
+        /* Check if the superblock moved earlier in the file */
+        if (H5F_addr_lt(shared->super_addr, shared->base_addr))
+            stored_eoa -= (shared->base_addr - shared->super_addr);
+        else
+            /* The superblock moved later in the file */
+            stored_eoa += (shared->super_addr - shared->base_addr);
+
+        shared->base_addr = shared->super_addr;
+    } /* end if */
+
+    /* Compute super block checksum */
+    assert(sizeof(chksum) == sizeof(shared->super_chksum));
+    for (q = (uint8_t *)&chksum, chksum = 0, i = 0; i < fixed_size + variable_size; ++i)
+        q[i % sizeof(shared->super_chksum)] ^= start_p[i];
+
+    /* Set the super block checksum */
+    shared->super_chksum = chksum;
+
+    /* 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(shared->fam_to_sec2)
+        shared->driver_addr = HADDR_UNDEF;
+            
+    /* Decode the optional driver information block */
+    if (H5F_addr_defined(shared->driver_addr)) {
+        haddr_t drv_addr = shared->base_addr + shared->driver_addr;
+        uint8_t dbuf[H5F_DRVINFOBLOCK_SIZE];     /* Local buffer                 */
+        size_t dbuf_size;               /* Size available for driver info */
+        const uint8_t *driver_p;        /* Remember beginning of driver info block */
+
+        if(!buf) {
+            driver_p = p = dbuf;
+            dbuf_size=sizeof(dbuf);
+
+            if (H5FD_set_eoa(lf, drv_addr + 16) < 0 ||
+                    H5FD_read(lf, H5FD_MEM_SUPER, dxpl_id, drv_addr, (size_t)16, p) < 0)
+                HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "unable to read driver information block")
+        } /* end if */
+        else {
+            driver_p = p;
+            dbuf_size=buf_size-(p-start_p);
+        } /* end else */
+
+        /* Version number */
+        if (HDF5_DRIVERINFO_VERSION != *p++)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "bad driver information block version number")
+
+        p += 3; /* reserved */
+
+        /* Driver info size */
+        UINT32DECODE(p, driver_size);
+
+        /* Driver name and/or version */
+        HDstrncpy(driver_name, (const char *)p, (size_t)8);
+        driver_name[8] = '\0';
+        p += 8; /* advance past name/version */
+
+        /* Read driver information and decode */
+        assert((driver_size + 16) <= dbuf_size);
+
+        if(!buf) {
+            if (H5FD_set_eoa(lf, drv_addr + 16 + driver_size) < 0 ||
+                    H5FD_read(lf, H5FD_MEM_SUPER, dxpl_id, drv_addr+16, driver_size, p) < 0)
+                HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "unable to read file driver information")
+        } /* end if */
+
+        /* Check if driver matches driver information saved. Unfortunately, we can't push this 
+         * function to each specific driver because we're checking if the driver is correct.*/
+        if(!HDstrncmp(driver_name, "NCSAfami", 8) && HDstrcmp(lf->cls->name, "family"))
+            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "family driver should be used")
+        if(!HDstrncmp(driver_name, "NCSAmult", 8) && HDstrcmp(lf->cls->name, "multi"))
+            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "multi driver should be used")
+           
+        if (H5FD_sb_decode(lf, driver_name, p) < 0)
+            HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "unable to decode driver information")
+
+        /* Compute driver info block checksum */
+        assert(sizeof(chksum) == sizeof(shared->drvr_chksum));
+        for (q = (uint8_t *)&chksum, chksum = 0, i = 0; i < (driver_size + 16); ++i)
+            q[i % sizeof(shared->drvr_chksum)] ^= driver_p[i];
+
+        /* Set the driver info block checksum */
+        shared->drvr_chksum = chksum;
+    } /* end if */
+    
+    /*
+     * The user-defined data is the area of the file before the base
+     * address.
+     */
+    if (H5P_set(c_plist, H5F_CRT_USER_BLOCK_NAME, &shared->base_addr) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTSET, FAIL, "unable to set usr block size")
+
+    /*
+     * 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)))
+        HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "unable to determine file size")
+
+#ifdef H5_HAVE_FPHDF5
+    if (!H5FD_is_fphdf5_driver(lf) || H5FD_fphdf5_is_captain(lf))
+#endif  /* !H5_HAVE_FPHDF5 */
+        if (eof < stored_eoa)
+            HGOTO_ERROR(H5E_FILE, H5E_TRUNCATED, FAIL, "truncated file")
+    
+    /*
+     * Tell the file driver how much address space has already been
+     * allocated so that it knows how to allocate additional memory.
+     */
+    if (H5FD_set_eoa(lf, stored_eoa) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTOPENFILE, FAIL, "unable to set end-of-address marker for file")
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+}
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5F_init_superblock
+ *
+ * Purpose:     Allocates the superblock for the file and initializes
+ *              information about the superblock in memory.  Does not write
+ *              any superblock information to the file.
+ *
+ * Return:      Success:        SUCCEED
+ *              Failure:        FAIL
+ *
+ * Programmer:  Quincey Koziol
+ *              koziol@ncsa.uiuc.edu
+ *              Sept 15, 2003
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+hsize_t
+H5F_init_superblock(const H5F_t *f, hid_t dxpl_id)
+{
+    hsize_t         userblock_size = 0;         /* Size of userblock, in bytes */
+    size_t          superblock_size;            /* Size of superblock, in bytes     */
+    size_t          driver_size;                /* Size of driver info block (bytes)*/
+    unsigned        super_vers;                 /* Super block version              */
+    haddr_t         addr;                       /* Address of superblock            */
+    H5P_genplist_t *plist;                      /* Property list                    */
+    hsize_t         ret_value;
+
+    /* Encoding */
+    FUNC_ENTER_NOAPI(H5F_init_superblock, UFAIL)
+
+    /* Get the shared file creation property list */
+    if (NULL == (plist = H5I_object(f->shared->fcpl_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, UFAIL, "not a property list")
+
+    /*
+     * The superblock starts immediately after the user-defined
+     * header, which we have already insured is a proper size. The
+     * base address is set to the same thing as the superblock for
+     * now.
+     */
+    if(H5P_get(plist, H5F_CRT_USER_BLOCK_NAME, &userblock_size) < 0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTGET, UFAIL, "unable to get user block size")
+    f->shared->super_addr = userblock_size;
+    f->shared->base_addr = f->shared->super_addr;
+    f->shared->consist_flags = 0x03;
+
+    /* Grab superblock version from property list */
+    if (H5P_get(plist, H5F_CRT_SUPER_VERS_NAME, &super_vers) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, UFAIL, "unable to get super block version")
+
+    /* Compute the size of the superblock */
+    superblock_size=H5F_SIGNATURE_LEN   /* Signature length (8 bytes) */
+        + 16                            /* Length of required fixed-size portion */
+        + ((super_vers>0) ? 4 : 0)      /* Version specific fixed-size portion */
+        + 4 * H5F_sizeof_addr(f)        /* Variable-sized addresses */
+        + H5G_SIZEOF_ENTRY(f);          /* Size of root group symbol table entry */
+
+    /* Compute the size of the driver information block. */
+    H5_ASSIGN_OVERFLOW(driver_size, H5FD_sb_size(f->shared->lf), hsize_t, size_t);
+    if (driver_size > 0)
+	driver_size += 16; /* Driver block header */
+
+    /*
+     * Allocate space for the userblock, superblock, and driver info
+     * block. We do it with one allocation request because the
+     * userblock and superblock need to be at the beginning of the
+     * file and only the first allocation request is required to
+     * return memory at format address zero.
+     */
+
+    H5_CHECK_OVERFLOW(f->shared->base_addr, haddr_t, hsize_t);
+    addr = H5FD_alloc(f->shared->lf, H5FD_MEM_SUPER, dxpl_id,
+                      ((hsize_t)f->shared->base_addr + superblock_size + driver_size));
+
+    if (HADDR_UNDEF == addr)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, UFAIL,
+                    "unable to allocate file space for userblock and/or superblock")
+
+    if (0 != addr)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, UFAIL,
+                    "file driver failed to allocate userblock and/or superblock at address zero")
+
+    /*
+     * The file driver information block begins immediately after the
+     * superblock.
+     */
+    if (driver_size > 0)
+        f->shared->driver_addr = superblock_size;
+
+    /* Return the size of the super block+driver info block */
+    ret_value=superblock_size+driver_size;
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+} /* end H5F_init_superblock() */
+
+
+/*-------------------------------------------------------------------------
+ * Function:    H5F_write_superblock
+ *
+ * Purpose:     Writes (and optionally allocates) the superblock for the file.
+ *              If BUF is non-NULL, then write the serialized superblock
+ *              information into it. It should be a buffer of size
+ *              H5F_SUPERBLOCK_SIZE + H5F_DRVINFOBLOCK_SIZE or larger.
+ *
+ * Return:      Success:        SUCCEED
+ *              Failure:        FAIL
+ *
+ * Programmer:  Bill Wendling
+ *              wendling@ncsa.uiuc.edu
+ *              Sept 12, 2003
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5F_write_superblock(H5F_t *f, hid_t dxpl_id, uint8_t *buf)
+{
+    uint8_t         sbuf[H5F_SUPERBLOCK_SIZE];  /* Superblock encoding buffer       */
+    uint8_t         dbuf[H5F_DRVINFOBLOCK_SIZE];/* Driver info block encoding buffer*/
+    uint8_t        *p = NULL;                   /* Ptr into encoding buffers        */
+    unsigned        i;                          /* Index variable                   */
+    unsigned        chksum;                     /* Checksum temporary variable      */
+    size_t          superblock_size;            /* Size of superblock, in bytes     */
+    size_t          driver_size;                /* Size of driver info block (bytes)*/
+    char            driver_name[9];             /* Name of driver, for driver info block */
+    unsigned        super_vers;                 /* Super block version              */
+    unsigned        freespace_vers;             /* Freespace info version           */
+    unsigned        obj_dir_vers;               /* Object header info version       */
+    unsigned        share_head_vers;            /* Shared header info version       */
+    H5P_genplist_t *plist;                      /* Property list                    */
+    herr_t          ret_value = SUCCEED;
+
+    /* Encoding */
+    FUNC_ENTER_NOAPI(H5F_write_superblock, FAIL)
+
+    /* Get the shared file creation property list */
+    if (NULL == (plist = H5I_object(f->shared->fcpl_id)))
+        HGOTO_ERROR(H5E_ARGS, H5E_BADTYPE, FAIL, "not a property list")
+
+    /* Grab values from property list */
+    if (H5P_get(plist, H5F_CRT_SUPER_VERS_NAME, &super_vers) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "unable to get super block version")
+    if (H5P_get(plist, H5F_CRT_FREESPACE_VERS_NAME, &freespace_vers) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "unable to get free space version")
+    if (H5P_get(plist, H5F_CRT_OBJ_DIR_VERS_NAME, &obj_dir_vers) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "unable to get object directory version")
+    if (H5P_get(plist, H5F_CRT_SHARE_HEAD_VERS_NAME, &share_head_vers) < 0)
+        HGOTO_ERROR(H5E_PLIST, H5E_CANTGET, FAIL, "unable to get shared-header format version")
+
+    /* Encode the file super block */
+    p = sbuf;
+    HDmemcpy(p, H5F_SIGNATURE, (size_t)H5F_SIGNATURE_LEN);
+    p += H5F_SIGNATURE_LEN;
+    *p++ = (uint8_t)super_vers;
+    *p++ = (uint8_t)freespace_vers;
+    *p++ = (uint8_t)obj_dir_vers;
+    *p++ = 0;   /* reserved*/
+    *p++ = (uint8_t)share_head_vers;
+    assert (H5F_SIZEOF_ADDR(f) <= 255);
+    *p++ = (uint8_t)H5F_SIZEOF_ADDR(f);
+    assert (H5F_SIZEOF_SIZE(f) <= 255);
+    *p++ = (uint8_t)H5F_SIZEOF_SIZE(f);
+    *p++ = 0;   /* reserved */
+    UINT16ENCODE(p, f->shared->sym_leaf_k);
+    UINT16ENCODE(p, f->shared->btree_k[H5B_SNODE_ID]);
+    UINT32ENCODE(p, f->shared->consist_flags);    
+
+    /*
+     * Versions of the superblock >0 have the indexed storage B-tree
+     * internal 'K' value stored
+     */
+    if (super_vers > 0) {
+        UINT16ENCODE(p, f->shared->btree_k[H5B_ISTORE_ID]);
+        *p++ = 0;   /*reserved */
+        *p++ = 0;   /*reserved */
+    }
+
+    H5F_addr_encode(f, &p, f->shared->base_addr);
+    H5F_addr_encode(f, &p, f->shared->freespace_addr);
+    H5F_addr_encode(f, &p, H5FD_get_eoa(f->shared->lf));
+    H5F_addr_encode(f, &p, f->shared->driver_addr);
+    if(H5G_ent_encode(f, &p, H5G_entof(f->shared->root_grp))<0)
+        HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "unable to encode root group information")
+
+    H5_ASSIGN_OVERFLOW(superblock_size, p - sbuf, int, size_t);
+
+    /* Double check we didn't overrun the block (unlikely) */
+    assert(superblock_size <= sizeof(sbuf));
+
+    /* Encode the driver information block. */
+    H5_ASSIGN_OVERFLOW(driver_size, H5FD_sb_size(f->shared->lf), hsize_t, size_t);
+
+    if (driver_size > 0) {
+	driver_size += 16; /* Driver block header */
+
+        /* Double check we didn't overrun the block (unlikely) */
+	assert(driver_size <= sizeof(dbuf));
+
+        /* Encode the driver information block */
+	p = dbuf;
+
+	*p++ = HDF5_DRIVERINFO_VERSION; /* Version */
+	*p++ = 0; /* reserved */
+	*p++ = 0; /* reserved */
+	*p++ = 0; /* reserved */
+
+	/* Driver info size, excluding header */
+	UINT32ENCODE(p, driver_size - 16);
+
+	/* Encode driver-specific data */
+	if (H5FD_sb_encode(f->shared->lf, driver_name, dbuf + 16) < 0)
+	    HGOTO_ERROR(H5E_FILE, H5E_CANTINIT, FAIL, "unable to encode driver information")
+
+	/* Driver name */
+	HDmemcpy(dbuf + 8, driver_name, (size_t)8);
+    } /* end if */
+
+    /* Compute super block checksum */
+    assert(sizeof(chksum) == sizeof(f->shared->super_chksum));
+
+    for (p = (uint8_t *)&chksum, chksum = 0, i = 0; i < superblock_size; ++i)
+        p[i % sizeof(f->shared->super_chksum)] ^= sbuf[i];
+
+    /* Compare with current checksums */
+    if (chksum != f->shared->super_chksum) {
+        /* Write superblock */
+        if (H5FD_write(f->shared->lf, H5FD_MEM_SUPER, dxpl_id,
+                       f->shared->super_addr, superblock_size, sbuf) < 0)
+            HGOTO_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "unable to write superblock")
+
+        /* Update checksum information if different */
+        f->shared->super_chksum = chksum;
+    } /* end if */
+
+    /* Check for driver info block */
+    if (HADDR_UNDEF != f->shared->driver_addr) {
+        /* Compute driver info block checksum */
+        assert(sizeof(chksum) == sizeof(f->shared->drvr_chksum));
+
+        for (p = (uint8_t *)&chksum, chksum = 0, i = 0; i < driver_size; ++i)
+            p[i % sizeof(f->shared->drvr_chksum)] ^= dbuf[i];
+
+        /* Compare with current checksums */
+        if (chksum != f->shared->drvr_chksum) {
+            /* Write driver information block */
+            if (H5FD_write(f->shared->lf, H5FD_MEM_SUPER, dxpl_id,
+                           f->shared->base_addr + f->shared->driver_addr, driver_size, dbuf) < 0)
+                HGOTO_ERROR(H5E_IO, H5E_WRITEERROR, FAIL, "unable to write driver information block")
+
+            /* Update checksum information if different */
+            f->shared->drvr_chksum = chksum;
+        } /* end if */
+    } /* end if */
+
+    /* Update the user's buffer, if given */
+    if (buf) {
+        HDmemcpy(buf, sbuf, superblock_size);
+        HDmemcpy(&buf[superblock_size], dbuf, driver_size);
+    } /* end if */
+
+done:
+    FUNC_LEAVE_NOAPI(ret_value)
+}
+
diff --git a/src/H5G.c b/src/H5G.c
index 86c541b..1f8a2ac 100644
--- a/src/H5G.c
+++ b/src/H5G.c
@@ -2254,6 +2254,11 @@ H5G_close(H5G_t *grp)
             HGOTO_ERROR(H5E_SYM, H5E_CANTINIT, FAIL, "unable to close");
         H5FL_FREE (H5G_shared_t, grp->shared);
     } else {
+        /* Check if this group was the last object holding open a mounted file
+         * hierarchy and close down the file hierarchy if so */
+        if(grp->shared->fo_count == 1)
+            H5F_check_mounts(grp->ent.file);
+
         if(H5G_free_ent_name(&(grp->ent))<0)
         {
             H5FL_FREE (H5G_t,grp);
@@ -4094,3 +4099,29 @@ done:
     FUNC_LEAVE_NOAPI(ret_value); 
 }
 
+
+/*-------------------------------------------------------------------------
+ * Function:	H5G_get_shared_count
+ *
+ * Purpose:	Queries the group object's "shared count"
+ *
+ * Return:	Non-negative on success/Negative on failure
+ *
+ * Programmer:	Quincey Koziol
+ *		Tuesday, July	 5, 2005
+ *
+ * Modifications:
+ *
+ *-------------------------------------------------------------------------
+ */
+herr_t
+H5G_get_shared_count(H5G_t *grp)
+{
+    FUNC_ENTER_NOAPI_NOINIT_NOFUNC(H5G_get_shared_count);
+
+    /* Check args */
+    assert(grp && grp->shared);
+
+    FUNC_LEAVE_NOAPI(grp->shared->fo_count);
+} /* end H5G_get_shared_count() */
+
diff --git a/src/H5Gprivate.h b/src/H5Gprivate.h
index ec83f3f..f1a57cb 100644
--- a/src/H5Gprivate.h
+++ b/src/H5Gprivate.h
@@ -166,6 +166,7 @@ H5_DLL  herr_t H5G_replace_name(H5G_obj_t type, H5G_entry_t *loc,
         H5RS_str_t *src_name, H5G_entry_t *src_loc,
         H5RS_str_t *dst_name, H5G_entry_t *dst_loc, H5G_names_op_t op);
 H5_DLL  herr_t H5G_free_grp_name(H5G_t *grp);
+H5_DLL herr_t H5G_get_shared_count(H5G_t *grp);
 
 /*
  * These functions operate on symbol table nodes.
diff --git a/src/Makefile.am b/src/Makefile.am
index 3a142fa..0349292 100755
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -47,7 +47,7 @@ libhdf5_la_SOURCES= H5.c H5A.c H5AC.c H5B.c H5B2.c H5B2cache.c H5B2dbg.c      \
         H5Dcontig.c \
         H5Dcompact.c \
         H5Defl.c H5Dio.c H5Distore.c H5Dmpio.c H5Dselect.c H5Dtest.c H5E.c H5F.c \
-        H5Fdbg.c H5FD.c H5FDcore.c  \
+        H5Fdbg.c H5Fmount.c H5Fsuper.c H5FD.c H5FDcore.c  \
         H5FDfamily.c H5FDfphdf5.c H5FDlog.c H5FDmpi.c H5FDmpio.c   \
         H5FDmpiposix.c H5FDmulti.c H5FDsec2.c H5FDstdio.c           \
         H5FDstream.c H5FL.c H5FO.c H5FP.c H5FPclient.c H5FPserver.c H5FS.c    \
diff --git a/src/Makefile.in b/src/Makefile.in
index b5ceba6..f22db4c 100644
--- a/src/Makefile.in
+++ b/src/Makefile.in
@@ -86,10 +86,10 @@ am_libhdf5_la_OBJECTS = H5.lo H5A.lo H5AC.lo H5B.lo H5B2.lo \
 	H5B2cache.lo H5B2dbg.lo H5B2test.lo H5BT.lo H5BTbtree2.lo \
 	H5BTcache.lo H5BTdbg.lo H5BTtest.lo H5C.lo H5D.lo H5Dcontig.lo \
 	H5Dcompact.lo H5Defl.lo H5Dio.lo H5Distore.lo H5Dmpio.lo \
-	H5Dselect.lo H5Dtest.lo H5E.lo H5F.lo H5Fdbg.lo H5FD.lo \
-	H5FDcore.lo H5FDfamily.lo H5FDfphdf5.lo H5FDlog.lo H5FDmpi.lo \
-	H5FDmpio.lo H5FDmpiposix.lo H5FDmulti.lo H5FDsec2.lo \
-	H5FDstdio.lo H5FDstream.lo H5FL.lo H5FO.lo H5FP.lo \
+	H5Dselect.lo H5Dtest.lo H5E.lo H5F.lo H5Fdbg.lo H5Fmount.lo \
+	H5Fsuper.lo H5FD.lo H5FDcore.lo H5FDfamily.lo H5FDfphdf5.lo \
+	H5FDlog.lo H5FDmpi.lo H5FDmpio.lo H5FDmpiposix.lo H5FDmulti.lo \
+	H5FDsec2.lo H5FDstdio.lo H5FDstream.lo H5FL.lo H5FO.lo H5FP.lo \
 	H5FPclient.lo H5FPserver.lo H5FS.lo H5G.lo H5Gent.lo \
 	H5Gnode.lo H5Gstab.lo H5HG.lo H5HGdbg.lo H5HL.lo H5HLdbg.lo \
 	H5HP.lo H5I.lo H5MF.lo H5MM.lo H5MP.lo H5MPtest.lo H5O.lo \
@@ -367,7 +367,7 @@ libhdf5_la_SOURCES = H5.c H5A.c H5AC.c H5B.c H5B2.c H5B2cache.c H5B2dbg.c      \
         H5Dcontig.c \
         H5Dcompact.c \
         H5Defl.c H5Dio.c H5Distore.c H5Dmpio.c H5Dselect.c H5Dtest.c H5E.c H5F.c \
-        H5Fdbg.c H5FD.c H5FDcore.c  \
+        H5Fdbg.c H5Fmount.c H5Fsuper.c H5FD.c H5FDcore.c  \
         H5FDfamily.c H5FDfphdf5.c H5FDlog.c H5FDmpi.c H5FDmpio.c   \
         H5FDmpiposix.c H5FDmulti.c H5FDsec2.c H5FDstdio.c           \
         H5FDstream.c H5FL.c H5FO.c H5FP.c H5FPclient.c H5FPserver.c H5FS.c    \
@@ -565,6 +565,8 @@ distclean-compile:
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5FPserver.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5FS.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5Fdbg.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5Fmount.Plo@am__quote@
+@AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5Fsuper.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5G.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5Gent.Plo@am__quote@
 @AMDEP_TRUE@@am__include@ @am__quote@./$(DEPDIR)/H5Gnode.Plo@am__quote@