Hi Harshad, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on ext4/dev] [also build test WARNING on linus/master v5.9-rc5 next-20200918] [cannot apply to tip/perf/core tytso-fscrypt/master] [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/Harshad-Shirwadkar/ext4-add-fast... base: https://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4.git dev config: arm-randconfig-s031-20200917 (attached as .config) compiler: arm-linux-gnueabi-gcc (GCC) 9.3.0 reproduce: wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # apt-get install sparse # sparse version: v0.6.2-201-g24bdaac6-dirty # save the attached .config to linux build tree COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross C=1 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__' ARCH=arm If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp(a)intel.com&gt; sparse warnings: (new ones prefixed by >>) # https://github.com/0day-ci/linux/commit/2384cbfbcf98b789d426c39b458c52adb... git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Harshad-Shirwadkar/ext4-add-fast-commits-feature/20200919-085652 git checkout 2384cbfbcf98b789d426c39b458c52adbb36d4f9 vim +806 fs/ext4/fast_commit.c 754 755 /* 756 * Writes updated data ranges for the inode in question. Updates CRC. 757 * Returns 0 on success, error otherwise. 758 */ 759 static int ext4_fc_write_data(struct inode *inode, u32 *crc) 760 { 761 ext4_lblk_t old_blk_size, cur_lblk_off, new_blk_size; 762 struct ext4_inode_info *ei = EXT4_I(inode); 763 struct ext4_map_blocks map; 764 struct ext4_fc_add_range fc_ext; 765 struct ext4_fc_del_range lrange; 766 struct ext4_extent *ex; 767 int ret; 768 769 mutex_lock(&ei->i_fc_lock); 770 if (ei->i_fc_lblk_len == 0) { 771 mutex_unlock(&ei->i_fc_lock); 772 return 0; 773 } 774 old_blk_size = ei->i_fc_lblk_start; 775 new_blk_size = ei->i_fc_lblk_start + ei->i_fc_lblk_len - 1; 776 ei->i_fc_lblk_len = 0; 777 mutex_unlock(&ei->i_fc_lock); 778 779 cur_lblk_off = old_blk_size; 780 jbd_debug(1, "%s: will try writing %d to %d for inode %ld\n", 781 __func__, cur_lblk_off, new_blk_size, inode->i_ino); 782 783 while (cur_lblk_off <= new_blk_size) { 784 map.m_lblk = cur_lblk_off; 785 map.m_len = new_blk_size - cur_lblk_off + 1; 786 ret = ext4_map_blocks(NULL, inode, &map, 0); 787 if (ret < 0) 788 return -ECANCELED; 789 790 if (map.m_len == 0) { 791 cur_lblk_off++; 792 continue; 793 } 794 795 if (ret == 0) { 796 lrange.fc_ino = cpu_to_le32(inode->i_ino); 797 lrange.fc_lblk = cpu_to_le32(map.m_lblk); 798 lrange.fc_len = cpu_to_le32(map.m_len); 799 if (!ext4_fc_add_tlv(inode->i_sb, EXT4_FC_TAG_DEL_RANGE, 800 sizeof(lrange), (u8 *)&lrange, crc)) 801 return -ENOSPC; 802 } else { 803 fc_ext.fc_ino = cpu_to_le32(inode->i_ino); 804 ex = (struct ext4_extent *)&fc_ext.fc_ex; 805 ex->ee_block = cpu_to_le32(map.m_lblk); 807 ext4_ext_store_pblock(ex, map.m_pblk); 808 if (map.m_flags & EXT4_MAP_UNWRITTEN) 809 ext4_ext_mark_unwritten(ex); 810 else 811 ext4_ext_mark_initialized(ex); 812 if (!ext4_fc_add_tlv(inode->i_sb, EXT4_FC_TAG_ADD_RANGE, 813 sizeof(fc_ext), (u8 *)&fc_ext, crc)) 814 return -ENOSPC; 815 } 816 817 cur_lblk_off += map.m_len; 818 } 819 820 return 0; 821 } 822 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@lists.01.org