fs/ntfs/usnjrnl.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * usnjrnl.h - NTFS kernel transaction log ($UsnJrnl) handling.  Part of the
   4  *             Linux-NTFS project.
   5  *
   6  * Copyright (c) 2005 Anton Altaparmakov
   7  */
   8
   9 #ifdef NTFS_RW
  10
  11 #include <linux/fs.h>
  12 #include <linux/highmem.h>
  13 #include <linux/mm.h>
  14
  15 #include "aops.h"
  16 #include "debug.h"
  17 #include "endian.h"
  18 #include "time.h"
  19 #include "types.h"
  20 #include "usnjrnl.h"
  21 #include "volume.h"
  22
  23 /**
  24  * ntfs_stamp_usnjrnl - stamp the transaction log ($UsnJrnl) on an ntfs volume
  25  * @vol:        ntfs volume on which to stamp the transaction log
  26  *
  27  * Stamp the transaction log ($UsnJrnl) on the ntfs volume @vol and return
  28  * 'true' on success and 'false' on error.
  29  *
  30  * This function assumes that the transaction log has already been loaded and
  31  * consistency checked by a call to fs/ntfs/super.c::load_and_init_usnjrnl().
  32  */
  33 bool ntfs_stamp_usnjrnl(ntfs_volume *vol)
  34 {
  35         ntfs_debug("Entering.");
  36         if (likely(!NVolUsnJrnlStamped(vol))) {
  37                 sle64 stamp;
  38                 struct page *page;
  39                 USN_HEADER *uh;
  40
  41                 page = ntfs_map_page(vol->usnjrnl_max_ino->i_mapping, 0);
  42                 if (IS_ERR(page)) {
  43                         ntfs_error(vol->sb, "Failed to read from "
  44                                         "$UsnJrnl/$DATA/$Max attribute.");
  45                         return false;
  46                 }
  47                 uh = (USN_HEADER*)page_address(page);
  48                 stamp = get_current_ntfs_time();
  49                 ntfs_debug("Stamping transaction log ($UsnJrnl): old "
  50                                 "journal_id 0x%llx, old lowest_valid_usn "
  51                                 "0x%llx, new journal_id 0x%llx, new "
  52                                 "lowest_valid_usn 0x%llx.",
  53                                 (long long)sle64_to_cpu(uh->journal_id),
  54                                 (long long)sle64_to_cpu(uh->lowest_valid_usn),
  55                                 (long long)sle64_to_cpu(stamp),
  56                                 i_size_read(vol->usnjrnl_j_ino));
  57                 uh->lowest_valid_usn =
  58                                 cpu_to_sle64(i_size_read(vol->usnjrnl_j_ino));
  59                 uh->journal_id = stamp;
  60                 flush_dcache_page(page);
  61                 set_page_dirty(page);
  62                 ntfs_unmap_page(page);
  63                 /* Set the flag so we do not have to do it again on remount. */
  64                 NVolSetUsnJrnlStamped(vol);
  65         }
  66         ntfs_debug("Done.");
  67         return true;
  68 }
  69
  70 #endif /* NTFS_RW */