lkml.org 
[lkml]   [2012]   [Nov]   [26]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    /
    SubjectRe: [PATCH 028/270] ext4: remove erroneous ext4_superblock_csum_set() in update_backups()
    From
    Date
    On Mon, 2012-11-26 at 14:55 -0200, Herton Ronaldo Krzesinski wrote:
    > 3.5.7u1 -stable review patch. If anyone has any objections, please let me know.
    >
    > ------------------
    >
    > From: Tao Ma <boyu.mt@taobao.com>
    >
    > commit bef53b01faeb791e27605cba1a71ba21364cb23e upstream.
    >
    > The update_backups() function is used to backup all the metadata
    > blocks, so we should not take it for granted that 'data' is pointed to
    > a super block and use ext4_superblock_csum_set to calculate the
    > checksum there. In case where the data is a group descriptor block,
    > it will corrupt the last group descriptor, and then e2fsck will
    > complain about it it.
    >
    > As all the metadata checksums should already be OK when we do the
    > backup, remove the wrong ext4_superblock_csum_set and it should be
    > just fine.
    >
    > Reported-by: "Theodore Ts'o" <tytso@mit.edu>
    > Signed-off-by: Tao Ma <boyu.mt@taobao.com>
    > Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
    > [ herton: adjust context ]
    > Signed-off-by: Herton Ronaldo Krzesinski <herton.krzesinski@canonical.com>

    This should also be applicable to 3.6.

    Ben.

    > ---
    > fs/ext4/resize.c | 2 --
    > 1 file changed, 2 deletions(-)
    >
    > diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
    > index b0bdd10..dc1affc 100644
    > --- a/fs/ext4/resize.c
    > +++ b/fs/ext4/resize.c
    > @@ -979,8 +979,6 @@ static void update_backups(struct super_block *sb,
    > goto exit_err;
    > }
    >
    > - ext4_superblock_csum_set(sb, (struct ext4_super_block *)data);
    > -
    > while ((group = ext4_list_backups(sb, &three, &five, &seven)) < last) {
    > struct buffer_head *bh;
    >

    --
    Ben Hutchings
    Never attribute to conspiracy what can adequately be explained by stupidity.
    [unhandled content-type:application/pgp-signature]
    \
     
     \ /
      Last update: 2012-11-27 04:01    [W:4.072 / U:0.044 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site