[PATCH 3.13 21/32] ext4: fix error return from ext4_ext_handle_uninitialized_extents()

Greg Kroah-Hartman
2014-04-21T04:37:09Z

From: Eric Whitney <enwlinux@gmail.com>

commit ce37c42919608e96ade3748fe23c3062a0a966c5 upstream.

Commit 3779473246 breaks the return of error codes from
ext4_ext_handle_uninitialized_extents() in ext4_ext_map_blocks(). A
portion of the patch assigns that function's signed integer return
value to an unsigned int. Consequently, negatively valued error codes
are lost and can be treated as a bogus allocated block count.

Signed-off-by: Eric Whitney <enwlinux@gmail.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
fs/ext4/extents.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -4128,7 +4128,7 @@ int ext4_ext_map_blocks(handle_t *handle
struct ext4_extent newex, *ex, *ex2;
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
ext4_fsblk_t newblock = 0;
- int free_on_err = 0, err = 0, depth;
+ int free_on_err = 0, err = 0, depth, ret;
unsigned int allocated = 0, offset = 0;
unsigned int allocated_clusters = 0;
struct ext4_allocation_request ar;
@@ -4189,9 +4189,13 @@ int ext4_ext_map_blocks(handle_t *handle
if (!ext4_ext_is_uninitialized(ex))
goto out;

- allocated = ext4_ext_handle_uninitialized_extents(
+ ret = ext4_ext_handle_uninitialized_extents(
handle, inode, map, path, flags,
allocated, newblock);
+ if (ret < 0)
+ err = ret;
+ else
+ allocated = ret;
goto out3;
}
}