src/patches/suse-2.6.27.31/patches.fixes/reiserfs-prealloc-fix

   1 From: Jeff Mahoney <jeffm@suse.com>
   2 Subject: [PATCH] reiserfs: Use list_del_init in use_preallocated_list_if_available
   3 References: bnc#378095
   4
   5  __discard_prealloc() calls list_del on ei->i_prealloc_list regardless of
   6  the state of ei->i_prealloc_count. The rest of the action in that function
   7  is safe regardless of if the list is empty or not.
   8
   9  If the list hasn't been used, then i_prealloc_list will be just initialized.
  10  If it has, and use_preallocated_list_if_available() has been called, and
  11  the prealloc list has been depleted, then the list entry will be poisoned.
  12
  13  This patch uses list_del_init so the list_head is initialized and we don't
  14  oops on the poisoned value.
  15
  16 Signed-off-by: Jeff Mahoney <jeffm@suse.com>
  17
  18 ---
  19  fs/reiserfs/bitmap.c |   11 ++++++-----
  20  1 file changed, 6 insertions(+), 5 deletions(-)
  21
  22 --- a/fs/reiserfs/bitmap.c
  23 +++ b/fs/reiserfs/bitmap.c
  24 @@ -1145,17 +1145,18 @@ static int use_preallocated_list_if_avai
  25                                               int amount_needed)
  26  {
  27         struct inode *inode = hint->inode;
  28 +       struct reiserfs_inode_info *ei = REISERFS_I(inode);
  29
  30 -       if (REISERFS_I(inode)->i_prealloc_count > 0) {
  31 +       if (ei->i_prealloc_count > 0) {
  32                 while (amount_needed) {
  33
  34 -                       *new_blocknrs++ = REISERFS_I(inode)->i_prealloc_block++;
  35 -                       REISERFS_I(inode)->i_prealloc_count--;
  36 +                       *new_blocknrs++ = ei->i_prealloc_block++;
  37 +                       ei->i_prealloc_count--;
  38
  39                         amount_needed--;
  40
  41 -                       if (REISERFS_I(inode)->i_prealloc_count <= 0) {
  42 -                               list_del(&REISERFS_I(inode)->i_prealloc_list);
  43 +                       if (ei->i_prealloc_count <= 0) {
  44 +                               list_del_init(&ei->i_prealloc_list);
  45                                 break;
  46                         }
  47                 }