Merge tag 'v2.6.38' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

[mv-sheeva.git] / fs / xfs / xfs_iomap.c

diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index 55582bd66659140ed9592a85ec0189187bcfd4ac..8a0f044750c3207eff174c4137bcd77580465894 100644 (file)
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -337,7 +337,12 @@ xfs_iomap_prealloc_size(
                int shift = 0;
                int64_t freesp;
 
-               alloc_blocks = XFS_B_TO_FSB(mp, ip->i_size);
+               /*
+                * rounddown_pow_of_two() returns an undefined result
+                * if we pass in alloc_blocks = 0. Hence the "+ 1" to
+                * ensure we always pass in a non-zero value.
+                */
+               alloc_blocks = XFS_B_TO_FSB(mp, ip->i_size) + 1;
                alloc_blocks = XFS_FILEOFF_MIN(MAXEXTLEN,
                                        rounddown_pow_of_two(alloc_blocks));