Hi Qu, Thank you for the patch! Yet something to improve: [auto build test ERROR on kdave/for-next] [also build test ERROR on v5.9-rc6 next-20200921] [cannot apply to btrfs/next] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Qu-Wenruo/btrfs-fix-false-alert-... base: https://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux.git for-next config: x86_64-randconfig-s021-20200920 (attached as .config) compiler: gcc-9 (Debian 9.3.0-15) 9.3.0 reproduce: # apt-get install sparse # sparse version: v0.6.2-201-g24bdaac6-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: 651 | static __inline__ size_t btrfs_legacy_root_item_size(void) | ^~~~~~ ./usr/include/linux/btrfs_tree.h: In function 'btrfs_legacy_root_item_size': 653 | return offsetof(struct btrfs_root_item, generation_v2); | ^~~~~~~~ ./usr/include/linux/btrfs_tree.h:6:1: note: 'offsetof' is defined in header '<stddef.h>'; did you forget to '#include <stddef.h>'? 5 | #include <linux/btrfs.h> +++ |+#include <stddef.h> 6 | #include <linux/types.h> 653 | return offsetof(struct btrfs_root_item, generation_v2); | ^~~~~~ cc1: some warnings being treated as errors --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org