diff --git a/[refs] b/[refs]
index a4cdea36d7c0..7bedf2060ea5 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: e942f883bc6651d50be139477baf6fb0eed3d5bb
+refs/heads/master: 1cba0cdf5e4dbcd9e5fa5b54d7a028e55e2ca057
diff --git a/trunk/fs/btrfs/volumes.c b/trunk/fs/btrfs/volumes.c
index 7992dc4ea4cc..5d6010ba8b7e 100644
--- a/trunk/fs/btrfs/volumes.c
+++ b/trunk/fs/btrfs/volumes.c
@@ -650,6 +650,7 @@ static int __btrfs_close_devices(struct btrfs_fs_devices *fs_devices)
 		new_device->writeable = 0;
 		new_device->in_fs_metadata = 0;
 		new_device->can_discard = 0;
+		spin_lock_init(&new_device->io_lock);
 		list_replace_rcu(&device->dev_list, &new_device->dev_list);
 
 		call_rcu(&device->rcu, free_device);