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    Subject[25/93] freeze_bdev: dont deactivate successfully frozen MS_RDONLY sb
    2.6.32-stable review patch.  If anyone has any objections, please let us know.


    From: Jun'ichi Nomura <>

    commit 4b06e5b9ad8abb20105b2b25e42c509ebe9b2d76 upstream.

    Thanks Thomas and Christoph for testing and review.
    I removed 'smp_wmb()' before up_write from the previous patch,
    since up_write() should have necessary ordering constraints.
    (I.e. the change of s_frozen is visible to others after up_write)
    I'm quite sure the change is harmless but if you are uncomfortable
    with Tested-by/Reviewed-by on the modified patch, please remove them.

    If MS_RDONLY, freeze_bdev should just up_write(s_umount) instead of
    Also, keep sb->s_frozen consistent so that remount can check the frozen state.

    Otherwise a crash reported here can happen:

    This patch should be applied for 2.6.32 stable series, too.

    Reviewed-by: Christoph Hellwig <>
    Tested-by: Thomas Backlund <>
    Signed-off-by: Jun'ichi Nomura <>
    Signed-off-by: Al Viro <>
    Signed-off-by: Greg Kroah-Hartman <>

    --- a/fs/block_dev.c
    +++ b/fs/block_dev.c
    @@ -246,7 +246,8 @@ struct super_block *freeze_bdev(struct block_device *bdev)
    if (!sb)
    goto out;
    if (sb->s_flags & MS_RDONLY) {
    - deactivate_locked_super(sb);
    + sb->s_frozen = SB_FREEZE_TRANS;
    + up_write(&sb->s_umount);
    return sb;
    @@ -307,7 +308,7 @@ int thaw_bdev(struct block_device *bdev, struct super_block *sb)
    BUG_ON(sb->s_bdev != bdev);
    if (sb->s_flags & MS_RDONLY)
    - goto out_deactivate;
    + goto out_unfrozen;

    if (sb->s_op->unfreeze_fs) {
    error = sb->s_op->unfreeze_fs(sb);
    @@ -321,11 +322,11 @@ int thaw_bdev(struct block_device *bdev, struct super_block *sb)

    sb->s_frozen = SB_UNFROZEN;

    if (sb)

     \ /
      Last update: 2010-02-19 18:17    [W:0.021 / U:41.636 seconds]
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