tree: https://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux.git online-fsuuid-ops head: 8ba53cec9e21583583121dbf00e661051371c35f commit: 4bf40510d99839ff689cf55e160013b80622801f [171/173] vfs: create ioctls to query and set the filesystem uuids config: x86_64-randconfig-s2-20200229 (attached as .config) compiler: gcc-4.9 (Debian 4.9.2-10+deb8u1) 4.9.2 reproduce: git checkout 4bf40510d99839ff689cf55e160013b80622801f # save the attached .config to linux build tree make ARCH=x86_64 If you fix the issue, kindly add following tag Reported-by: kbuild test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): In file included from ./usr/include/linux/romfs_fs.h:6:0, from <command-line>:1: uint32_t fu_flags; ^ uint16_t fu_length; ^ ./usr/include/linux/fs.h:145:2: error: unknown type name 'uint16_t' uint16_t fu_reserved; ^ uint64_t fu_reserved1; ^ static __inline__ size_t ioc_fsuuid_sizeof(size_t payload_len) ^ ./usr/include/linux/fs.h:157:44: error: unknown type name 'size_t' static __inline__ size_t ioc_fsuuid_sizeof(size_t payload_len) ^ --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org