Hi Christian, I love your patch! Yet something to improve: [auto build test ERROR on dcb7fd82c75ee2d6e6f9d8cc71c52519ed52e258] url: https://github.com/0day-ci/linux/commits/Christian-Brauner/fs-add-mount_s... base: dcb7fd82c75ee2d6e6f9d8cc71c52519ed52e258 config: x86_64-randconfig-s022-20200719 (attached as .config) compiler: gcc-9 (Debian 9.3.0-14) 9.3.0 reproduce: # apt-get install sparse # sparse version: v0.6.2-49-g707c5017-dirty # save the attached .config to linux build tree make W=1 C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=x86_64 If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; All errors (new ones prefixed by >>): In file included from <command-line>:32: ./usr/include/linux/mount.h:124:2: error: unknown type name '__u64' 124 | __u64 attr_set; | ^~~~~ ./usr/include/linux/mount.h:125:2: error: unknown type name '__u64' 125 | __u64 attr_clr; | ^~~~~ 126 | __u32 propagation; | ^~~~~ ./usr/include/linux/mount.h:127:2: error: unknown type name '__u32' 127 | __u32 atime; | ^~~~~ --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org