v4.19.13 snapshot.
diff --git a/include/linux/msdos_fs.h b/include/linux/msdos_fs.h
new file mode 100644
index 0000000..b7a5d4c
--- /dev/null
+++ b/include/linux/msdos_fs.h
@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_MSDOS_FS_H
+#define _LINUX_MSDOS_FS_H
+
+#include <uapi/linux/msdos_fs.h>
+
+/* media of boot sector */
+static inline int fat_valid_media(u8 media)
+{
+	return 0xf8 <= media || media == 0xf0;
+}
+#endif /* !_LINUX_MSDOS_FS_H */