1 files changed, 1 insertions, 0 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index c25ef0a68f18..6c953a0e0aa3 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -300,6 +300,7 @@ static int __setup_root(int blocksize,
         memset(&root->defrag_progress, 0, sizeof(root->defrag_progress));
         memset(&root->root_kobj, 0, sizeof(root->root_kobj));
         init_completion(&root->kobj_unregister);
+        init_rwsem(&root->snap_sem);
         root->defrag_running = 0;
         root->defrag_level = 0;
         root->root_key.objectid = objectid;