keep-existing-extra-fields-when-inode-expands

   1 ext4: keep existing extra fields when inode expands
   2
   3 From: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
   4
   5 ext4_expand_extra_isize() should clear only space between old and new
   6 size.
   7
   8 Fixes: 6dd4ee7cab7e # v2.6.23
   9 Cc: stable@vger.kernel.org
  10 Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
  11 Signed-off-by: Theodore Ts'o <tytso@mit.edu>
  12 ---
  13  fs/ext4/inode.c |    5 +++--
  14  1 file changed, 3 insertions(+), 2 deletions(-)
  15
  16 diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
  17 index 5834c4d76be8..7204e1a2801a 100644
  18 --- a/fs/ext4/inode.c
  19 +++ b/fs/ext4/inode.c
  20 @@ -5637,8 +5637,9 @@ static int ext4_expand_extra_isize(struct inode *inode,
  21         /* No extended attributes present */
  22         if (!ext4_test_inode_state(inode, EXT4_STATE_XATTR) ||
  23             header->h_magic != cpu_to_le32(EXT4_XATTR_MAGIC)) {
  24 -               memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE, 0,
  25 -                       new_extra_isize);
  26 +               memset((void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE +
  27 +                      EXT4_I(inode)->i_extra_isize, 0,
  28 +                      new_extra_isize - EXT4_I(inode)->i_extra_isize);
  29                 EXT4_I(inode)->i_extra_isize = new_extra_isize;
  30                 return 0;
  31         }
  32
  33