Btrfs: remove BUG_ON() due to mounting bad filesystem

Mounting a bad filesystem caused a BUG_ON(). The following is steps to
reproduce it.
 # mkfs.btrfs /dev/sda2
 # mount /dev/sda2 /mnt
 # mkfs.btrfs /dev/sda1 /dev/sda2
 (the program says that /dev/sda2 was mounted, and then exits. )
 # umount /mnt
 # mount /dev/sda1 /mnt

At the third step, mkfs.btrfs exited in the way of make filesystem. So the
initialization of the filesystem didn't finish. So the filesystem was bad, and
it caused BUG_ON() when mounting it. But BUG_ON() should be called by the wrong
code, not user's operation, so I think it is a bug of btrfs.

This patch fixes it.

Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <chris.mason@oracle.com>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index ed3e4a2ec2c8..ab7ab5318745 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -3764,7 +3764,8 @@ out:
                                        BTRFS_DATA_RELOC_TREE_OBJECTID);
                 if (IS_ERR(fs_root))
                         err = PTR_ERR(fs_root);
-                btrfs_orphan_cleanup(fs_root);
+                else
+                        btrfs_orphan_cleanup(fs_root);
         }
         return err;
 }