diff --git a/fs/btrfs/hash.h b/fs/btrfs/hash.h
new file mode 100644
index 0000000..e56c467
--- /dev/null
+++ b/fs/btrfs/hash.h
@@ -0,0 +1,4 @@
+#ifndef __HASH__
+#define __HASH__
+int btrfs_name_hash(const char *name, int len, u64 *hash_result);
+#endif