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>

diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index d2ac518..3e6e410 100644 (file)
--- 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;
 }