4.9-stable review patch. If anyone has any objections, please let me know.
------------------
From: Liu Bo bo.li.liu@oracle.com
commit e89166990f11c3f21e1649d760dd35f9e410321c upstream.
@cur_offset is not set back to what it should be (@cow_start) if btrfs_next_leaf() returns something wrong, and the range [cow_start, cur_offset) remains locked forever.
cc: stable@vger.kernel.org Signed-off-by: Liu Bo bo.li.liu@oracle.com Reviewed-by: Josef Bacik jbacik@fb.com Signed-off-by: David Sterba dsterba@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- fs/btrfs/inode.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
--- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -1320,8 +1320,11 @@ next_slot: leaf = path->nodes[0]; if (path->slots[0] >= btrfs_header_nritems(leaf)) { ret = btrfs_next_leaf(root, path); - if (ret < 0) + if (ret < 0) { + if (cow_start != (u64)-1) + cur_offset = cow_start; goto error; + } if (ret > 0) break; leaf = path->nodes[0];