xfs: fix unsigned underflow in xfs_free_eofblocks

map_len is unsigned. Checking map_len <= 0 is buggy when it should be
below zero. So, check exact expression instead of map_len.

Signed-off-by: Kulikov Vasiliy <segooon@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Dave Chinner <david@fromorbit.com>
This commit is contained in:
Kulikov Vasiliy 2010-07-20 17:54:28 +10:00 committed by Alex Elder
parent aea1b95321
commit 3f34885cd7
1 changed files with 2 additions and 2 deletions

View File

@ -589,9 +589,9 @@ xfs_free_eofblocks(
*/
end_fsb = XFS_B_TO_FSB(mp, ((xfs_ufsize_t)ip->i_size));
last_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_MAXIOFFSET(mp));
map_len = last_fsb - end_fsb;
if (map_len <= 0)
if (last_fsb <= end_fsb)
return 0;
map_len = last_fsb - end_fsb;
nimaps = 1;
xfs_ilock(ip, XFS_ILOCK_SHARED);