release/src-rt-6.x.4708/linux/linux-2.6.36/fs/ntfs/usnjrnl.c

   1 /*
   2  * usnjrnl.h - NTFS kernel transaction log ($UsnJrnl) handling.  Part of the
   3  *             Linux-NTFS project.
   4  *
   5  * Copyright (c) 2005 Anton Altaparmakov
   6  *
   7  * This program/include file is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU General Public License as published
   9  * by the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program/include file is distributed in the hope that it will be
  13  * useful, but WITHOUT ANY WARRANTY; without even the implied warranty
  14  * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program (in the main directory of the Linux-NTFS
  19  * distribution in the file COPYING); if not, write to the Free Software
  20  * Foundation,Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  21  */
  22
  23 #ifdef NTFS_RW
  24
  25 #include <linux/fs.h>
  26 #include <linux/highmem.h>
  27 #include <linux/mm.h>
  28
  29 #include "aops.h"
  30 #include "debug.h"
  31 #include "endian.h"
  32 #include "time.h"
  33 #include "types.h"
  34 #include "usnjrnl.h"
  35 #include "volume.h"
  36
  37 /**
  38  * ntfs_stamp_usnjrnl - stamp the transaction log ($UsnJrnl) on an ntfs volume
  39  * @vol:        ntfs volume on which to stamp the transaction log
  40  *
  41  * Stamp the transaction log ($UsnJrnl) on the ntfs volume @vol and return
  42  * 'true' on success and 'false' on error.
  43  *
  44  * This function assumes that the transaction log has already been loaded and
  45  * consistency checked by a call to fs/ntfs/super.c::load_and_init_usnjrnl().
  46  */
  47 bool ntfs_stamp_usnjrnl(ntfs_volume *vol)
  48 {
  49         ntfs_debug("Entering.");
  50         if (likely(!NVolUsnJrnlStamped(vol))) {
  51                 sle64 stamp;
  52                 struct page *page;
  53                 USN_HEADER *uh;
  54
  55                 page = ntfs_map_page(vol->usnjrnl_max_ino->i_mapping, 0);
  56                 if (IS_ERR(page)) {
  57                         ntfs_error(vol->sb, "Failed to read from "
  58                                         "$UsnJrnl/$DATA/$Max attribute.");
  59                         return false;
  60                 }
  61                 uh = (USN_HEADER*)page_address(page);
  62                 stamp = get_current_ntfs_time();
  63                 ntfs_debug("Stamping transaction log ($UsnJrnl): old "
  64                                 "journal_id 0x%llx, old lowest_valid_usn "
  65                                 "0x%llx, new journal_id 0x%llx, new "
  66                                 "lowest_valid_usn 0x%llx.",
  67                                 (long long)sle64_to_cpu(uh->journal_id),
  68                                 (long long)sle64_to_cpu(uh->lowest_valid_usn),
  69                                 (long long)sle64_to_cpu(stamp),
  70                                 i_size_read(vol->usnjrnl_j_ino));
  71                 uh->lowest_valid_usn =
  72                                 cpu_to_sle64(i_size_read(vol->usnjrnl_j_ino));
  73                 uh->journal_id = stamp;
  74                 flush_dcache_page(page);
  75                 set_page_dirty(page);
  76                 ntfs_unmap_page(page);
  77                 /* Set the flag so we do not have to do it again on remount. */
  78                 NVolSetUsnJrnlStamped(vol);
  79         }
  80         ntfs_debug("Done.");
  81         return true;
  82 }
  83
  84 #endif /* NTFS_RW */