diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index ef6865c..fe5aec9 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2903,6 +2903,7 @@
 
 	spin_lock(&delayed_refs->lock);
 	if (delayed_refs->num_entries == 0) {
+		spin_unlock(&delayed_refs->lock);
 		printk(KERN_INFO "delayed_refs has NO entry\n");
 		return ret;
 	}