diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 549a5f327428..944877a363fa 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1179,7 +1179,6 @@ static void submit_one_async_extent(struct async_chunk *async_chunk,
 		goto done;
 	}
 
-	lock_extent(io_tree, start, end, NULL);
 	ret = btrfs_reserve_extent(root, async_extent->ram_size,
 				   async_extent->compressed_size,
 				   async_extent->compressed_size,
@@ -1195,6 +1194,8 @@ static void submit_one_async_extent(struct async_chunk *async_chunk,
 		goto done;
 	}
 
+	lock_extent(io_tree, start, end, NULL);
+
 	/* Here we're doing allocation and writeback of the compressed pages */
 	em = create_io_em(inode, start,
 			  async_extent->ram_size,	/* len */