--- linux-4.9.37/fs/Makefile	2017-07-12 16:42:41.000000000 +0300
+++ linux-4.9.y/fs/Makefile	2021-06-07 13:01:34.000000000 +0300
@@ -129,3 +129,4 @@
 obj-$(CONFIG_CEPH_FS)		+= ceph/
 obj-$(CONFIG_PSTORE)		+= pstore/
 obj-$(CONFIG_EFIVAR_FS)		+= efivarfs/
+obj-$(CONFIG_YAFFS_FS)		+= yaffs2/