diff --git a/[refs] b/[refs]
index e4a8ecf70f28..746094efe938 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 57a5a882031dba5cb7bc7ebc955b897498365fe2
+refs/heads/master: 55e591ffde38e0088b022129e035e18a8d04c7e6
diff --git a/trunk/fs/btrfs/extent-tree.c b/trunk/fs/btrfs/extent-tree.c
index 4e1b153b7c47..45c69c4184c9 100644
--- a/trunk/fs/btrfs/extent-tree.c
+++ b/trunk/fs/btrfs/extent-tree.c
@@ -4571,8 +4571,10 @@ int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes)
 	if (root->fs_info->quota_enabled) {
 		ret = btrfs_qgroup_reserve(root, num_bytes +
 					   nr_extents * root->leafsize);
-		if (ret)
+		if (ret) {
+			mutex_unlock(&BTRFS_I(inode)->delalloc_mutex);
 			return ret;
+		}
 	}
 
 	ret = reserve_metadata_bytes(root, block_rsv, to_reserve, flush);