diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 8de561fb1390..4e998bf8d379 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -468,7 +468,7 @@ static void fs_path_free(struct fs_path *p)
 	kfree(p);
 }
 
-static int fs_path_len(struct fs_path *p)
+static inline int fs_path_len(const struct fs_path *p)
 {
 	return p->end - p->start;
 }