v4.19.13 snapshot.
diff --git a/include/linux/btrfs.h b/include/linux/btrfs.h
new file mode 100644
index 0000000..9a37a45
--- /dev/null
+++ b/include/linux/btrfs.h
@@ -0,0 +1,7 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_BTRFS_H
+#define _LINUX_BTRFS_H
+
+#include <uapi/linux/btrfs.h>
+
+#endif /* _LINUX_BTRFS_H */