Hi Naohiro, I love your patch! Perhaps something to improve: [auto build test WARNING on kdave/for-next] [cannot apply to v5.14-rc5 next-20210811] [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/Naohiro-Aota/ZNS-Support-for-Btr... base: https://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux.git for-next config: x86_64-randconfig-a012-20210810 (attached as .config) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project d39ebdae674c8efc84ebe8dc32716ec353220530) 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/ccecd271dc2436fe587af8d2083c3c96a... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Naohiro-Aota/ZNS-Support-for-Btrfs/20210811-222302 git checkout ccecd271dc2436fe587af8d2083c3c96ab86e309 # 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 warnings (new ones prefixed by >>): if (!device->zone_info->max_active_zones) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ fs/btrfs/zoned.c:1956:9: note: uninitialized use occurs here return ret; ^~~ fs/btrfs/zoned.c:1940:2: note: remove the 'if' if its condition is always true if (!device->zone_info->max_active_zones) { ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ fs/btrfs/zoned.c:1908:9: note: initialize the variable 'ret' to silence this warning int ret; ^ = 0 1 warning generated. vim +1940 fs/btrfs/zoned.c 1900 1901 int btrfs_zone_finish_endio(struct btrfs_fs_info *fs_info, u64 logical, 1902 u64 length) 1903 { 1904 struct btrfs_block_group *block_group; 1905 struct map_lookup *map; 1906 struct btrfs_device *device; 1907 u64 physical; 1908 int ret; 1909 1910 if (!btrfs_is_zoned(fs_info)) 1911 return 0; 1912 1913 block_group = btrfs_lookup_block_group(fs_info, logical); 1914 ASSERT(block_group); 1915 1916 if (logical + length < block_group->start + block_group->zone_capacity) { 1917 ret = 0; 1918 goto out; 1919 } 1920 1921 spin_lock(&block_group->lock); 1922 1923 if (!block_group->zone_is_active) { 1924 spin_unlock(&block_group->lock); 1925 ret = 0; 1926 goto out; 1927 } 1928 1929 block_group->zone_is_active = 0; 1930 /* We should have consumed all the free space */ 1931 ASSERT(block_group->alloc_offset == block_group->zone_capacity); 1932 ASSERT(block_group->free_space_ctl->free_space == 0); 1933 btrfs_clear_treelog_bg(block_group); 1934 spin_unlock(&block_group->lock); 1935 1936 map = block_group->physical_map; 1937 device = map->stripes[0].dev; 1938 physical = map->stripes[0].physical; 1939 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org