xfs: Fix off-by-in in loop termination in xfs_find_get_desired_pgoff()

There is an off-by-one error in loop termination conditions in
xfs_find_get_desired_pgoff() since 'end' may index a page beyond end of
desired range if 'endoff' is page aligned. It doesn't have any visible
effects but still it is good to fix it.

Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Orabug: 27093425

(backport upstream commit d7fd24257aa60316bf81093f7f909dc9475ae974)

Signed-off-by: Shan Hai <shan.hai@oracle.com>

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 4b9d0276acf9665075769363d46a360c745e8032..668f70e6d1c2eae5ab11fdc59dc544d0f5a74ecd 100644 (file)
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -1188,7 +1188,7 @@ xfs_find_get_desired_pgoff(
 
        index = startoff >> PAGE_CACHE_SHIFT;
        endoff = XFS_FSB_TO_B(mp, map->br_startoff + map->br_blockcount);
-       end = endoff >> PAGE_CACHE_SHIFT;
+       end = (endoff - 1) >> PAGE_CACHE_SHIFT;
        do {
                int             want;
                unsigned        nr_pages;