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authorChris Mason2009-10-09 11:29:53 -0400
committerChris Mason2009-10-09 11:29:53 -0400
commitac6889cbb254be1ffea376bea4a96ce9be0e0ed0 (patch)
tree8f0e073af940b1bdfb134b945a03a1b43b614352 /fs/btrfs
parente9061e214810c9534381a705a1b46533e09f2676 (diff)
Btrfs: fix file clone ioctl for bookend extents
The file clone ioctl was incorrectly taking the offset into the extent on disk into account when calculating the length of the cloned extent. The length never changes based on the offset into the physical extent. Test case: fallocate -l 1g image mke2fs image bcp image image2 e2fsck -f image2 (errors on image2) The math bug ends up wrapping the length of the extent, and things go wrong from there. Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs')
-rw-r--r--fs/btrfs/ioctl.c6
1 files changed, 4 insertions, 2 deletions
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index e8795becad4c..cdbb054102b9 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -1123,8 +1123,10 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
datao += off - key.offset;
datal -= off - key.offset;
}
- if (key.offset + datao + datal > off + len)
- datal = off + len - key.offset - datao;
+
+ if (key.offset + datal > off + len)
+ datal = off + len - key.offset;
+
/* disko == 0 means it's a hole */
if (!disko)
datao = 0;