fix-error-handling-in-ext4_ext_shift_extents

   1 ext4: fix error handling in ext4_ext_shift_extents
   2
   3 From: Dmitry Monakhov <dmonakhov@openvz.org>
   4
   5 Fix error handling by adding some.  :-)
   6
   7 Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
   8 Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
   9 ---
  10  fs/ext4/extents.c |   11 +++++++++--
  11  1 files changed, 9 insertions(+), 2 deletions(-)
  12
  13 diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
  14 index 96e0a4b..38be063 100644
  15 --- a/fs/ext4/extents.c
  16 +++ b/fs/ext4/extents.c
  17 @@ -5314,11 +5314,18 @@ ext4_ext_shift_extents(struct inode *inode, handle_t *handle,
  18          * enough to accomodate the shift.
  19          */
  20         path = ext4_ext_find_extent(inode, start - 1, NULL, 0);
  21 +       if (IS_ERR(path))
  22 +               return PTR_ERR(path);
  23         depth = path->p_depth;
  24         extent =  path[depth].p_ext;
  25 -       ex_start = le32_to_cpu(extent->ee_block);
  26 -       ex_end = le32_to_cpu(extent->ee_block) +
  27 +       if (extent) {
  28 +               ex_start = le32_to_cpu(extent->ee_block);
  29 +               ex_end = le32_to_cpu(extent->ee_block) +
  30                         ext4_ext_get_actual_len(extent);
  31 +       } else {
  32 +               ex_start = 0;
  33 +               ex_end = 0;
  34 +       }
  35         ext4_ext_drop_refs(path);
  36         kfree(path);
  37
  38 --
  39 1.7.1
  40
  41