Hi Shiyang, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on linux/master] [also build test WARNING on linus/master v5.17-rc1] [cannot apply to xfs-linux/for-next hnaz-mm/master next-20220128] [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/Shiyang-Ruan/fsdax-introduce-fs-query-to-support-reflink/20220127-204239 base: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git 2c271fe77d52a0555161926c232cd5bc07178b39 config: x86_64-randconfig-c007-20220124 (https://download.01.org/0day-ci/archive/20220129/202201290206.TU7AHhWg-lkp@xxxxxxxxx/config) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project f32dccb9a43b02ce4e540d6ba5dbbdb188f2dc7d) 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 # https://github.com/0day-ci/linux/commit/26822296a70d211de3c5f4ef903d4c4cf29179bd git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Shiyang-Ruan/fsdax-introduce-fs-query-to-support-reflink/20220127-204239 git checkout 26822296a70d211de3c5f4ef903d4c4cf29179bd # save the config file to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross ARCH=x86_64 clang-analyzer If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@xxxxxxxxx> clang-analyzer warnings: (new ones prefixed by >>) >> fs/dax.c:339:2: warning: Value stored to 'mapping' is never read [clang-analyzer-deadcode.DeadStores] mapping = (struct address_space *)PAGE_MAPPING_DAX_COW; ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ vim +/mapping +339 fs/dax.c d2c997c0f14535 Dan Williams 2017-12-22 328 d2c997c0f14535 Dan Williams 2017-12-22 329 /* d2c997c0f14535 Dan Williams 2017-12-22 330 * Iterate through all mapped pfns represented by an entry, i.e. skip d2c997c0f14535 Dan Williams 2017-12-22 331 * 'empty' and 'zero' entries. d2c997c0f14535 Dan Williams 2017-12-22 332 */ d2c997c0f14535 Dan Williams 2017-12-22 333 #define for_each_mapped_pfn(entry, pfn) \ a77d19f46a37c0 Matthew Wilcox 2018-03-27 334 for (pfn = dax_to_pfn(entry); \ a77d19f46a37c0 Matthew Wilcox 2018-03-27 335 pfn < dax_end_pfn(entry); pfn++) d2c997c0f14535 Dan Williams 2017-12-22 336 26822296a70d21 Shiyang Ruan 2022-01-27 337 static inline void dax_mapping_set_cow_flag(struct address_space *mapping) 26822296a70d21 Shiyang Ruan 2022-01-27 338 { 26822296a70d21 Shiyang Ruan 2022-01-27 @339 mapping = (struct address_space *)PAGE_MAPPING_DAX_COW; 26822296a70d21 Shiyang Ruan 2022-01-27 340 } 26822296a70d21 Shiyang Ruan 2022-01-27 341 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx
