releases/2.6.31.8/0079-ext4-wait-for-log-to-commit-when-umounting.patch

   1 From c086b107c572cba6d3600ae292a1e23627756fb0 Mon Sep 17 00:00:00 2001
   2 From: Josef Bacik <josef@redhat.com>
   3 Date: Tue, 8 Dec 2009 21:48:58 -0500
   4 Subject: [PATCH 79/85] ext4: wait for log to commit when umounting
   5
   6 (cherry picked from commit d4edac314e9ad0b21ba20ba8bc61b61f186f79e1)
   7
   8 There is a potential race when a transaction is committing right when
   9 the file system is being umounting.  This could reduce in a race
  10 because EXT4_SB(sb)->s_group_info could be freed in ext4_put_super
  11 before the commit code calls a callback so the mballoc code can
  12 release freed blocks in the transaction, resulting in a panic trying
  13 to access the freed s_group_info.
  14
  15 The fix is to wait for the transaction to finish committing before we
  16 shutdown the multiblock allocator.
  17
  18 Signed-off-by: Josef Bacik <josef@redhat.com>
  19 Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
  20 Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
  21 ---
  22  fs/ext4/super.c |   10 ++++++----
  23  1 file changed, 6 insertions(+), 4 deletions(-)
  24
  25 --- a/fs/ext4/super.c
  26 +++ b/fs/ext4/super.c
  27 @@ -610,10 +610,6 @@ static void ext4_put_super(struct super_
  28         if (sb->s_dirt)
  29                 ext4_commit_super(sb, 1);
  30
  31 -       ext4_release_system_zone(sb);
  32 -       ext4_mb_release(sb);
  33 -       ext4_ext_release(sb);
  34 -       ext4_xattr_put_super(sb);
  35         if (sbi->s_journal) {
  36                 err = jbd2_journal_destroy(sbi->s_journal);
  37                 sbi->s_journal = NULL;
  38 @@ -621,6 +617,12 @@ static void ext4_put_super(struct super_
  39                         ext4_abort(sb, __func__,
  40                                    "Couldn't clean up the journal");
  41         }
  42 +
  43 +       ext4_release_system_zone(sb);
  44 +       ext4_mb_release(sb);
  45 +       ext4_ext_release(sb);
  46 +       ext4_xattr_put_super(sb);
  47 +
  48         if (!(sb->s_flags & MS_RDONLY)) {
  49                 EXT4_CLEAR_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RECOVER);
  50                 es->s_state = cpu_to_le16(sbi->s_mount_state);