1 files changed, 2 insertions, 0 deletions

diff --git a/fs/btrfs/extent_map.c b/fs/btrfs/extent_map.c
index 9558d79faf1e..9d30acca55e1 100644
--- a/fs/btrfs/extent_map.c
+++ b/fs/btrfs/extent_map.c
@@ -384,6 +384,8 @@ int add_extent_mapping(struct extent_map_tree *tree,
 {
         int ret = 0;
 
+        lockdep_assert_held_write(&tree->lock);
+
         ret = tree_insert(&tree->map, em);
         if (ret)
                 goto out;