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-a015-20200719 (attached as .config) compiler: clang version 12.0.0 (https://github.com/llvm/llvm-project cf1105069648446d58adfb7a6cc590013d6886ba) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # install x86_64 cross compiling tool for clang build # apt-get install binutils-x86-64-linux-gnu # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross 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 <built-in>:1: ./usr/include/linux/mount.h:124:2: error: unknown type name '__u64' __u64 attr_set; ^ ./usr/include/linux/mount.h:125:2: error: unknown type name '__u64' __u64 attr_clr; ^ __u32 propagation; ^ ./usr/include/linux/mount.h:127:2: error: unknown type name '__u32' __u32 atime; ^ 4 errors generated. --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org