Btrfs: fix off-by-one in fiemap

lock_extent/unlock_extent expect an exclusive end.

Tested-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index d2ac518f90e4..3e6e410002e5 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -3989,7 +3989,7 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
                 last_for_get_extent = isize;
         }
 
-        lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len, 0,
+        lock_extent_bits(&BTRFS_I(inode)->io_tree, start, start + len - 1, 0,
                          &cached_state);
 
         em = get_extent_skip_holes(inode, start, last_for_get_extent,
@@ -4076,7 +4076,7 @@ int extent_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 out_free:
         free_extent_map(em);
 out:
-        unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len,
+        unlock_extent_cached(&BTRFS_I(inode)->io_tree, start, start + len - 1,
                              &cached_state, GFP_NOFS);
         return ret;
 }