Hi Nitesh, kernel test robot noticed the following build warnings: [auto build test WARNING on f7dc24b3413851109c4047b22997bd0d95ed52a2] url: https://github.com/intel-lab-lkp/linux/commits/Nitesh-Shetty/block-Introduce-queue-limits-and-sysfs-for-copy-offload-support/20230811-192259 base: f7dc24b3413851109c4047b22997bd0d95ed52a2 patch link: https://lore.kernel.org/r/20230811105300.15889-8-nj.shetty%40samsung.com patch subject: [PATCH v14 07/11] nvme: add copy offload support config: arm64-randconfig-r013-20230812 (https://download.01.org/0day-ci/archive/20230812/202308120736.Od5Pc9vy-lkp@xxxxxxxxx/config) compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a) reproduce: (https://download.01.org/0day-ci/archive/20230812/202308120736.Od5Pc9vy-lkp@xxxxxxxxx/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@xxxxxxxxx> | Closes: https://lore.kernel.org/oe-kbuild-all/202308120736.Od5Pc9vy-lkp@xxxxxxxxx/ All warnings (new ones prefixed by >>): >> drivers/nvme/host/core.c:782:2: warning: variable 'dst_lba' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] 782 | __rq_for_each_bio(bio, req) { | ^~~~~~~~~~~~~~~~~~~~~~~~~~~ include/linux/blk-mq.h:1008:6: note: expanded from macro '__rq_for_each_bio' 1008 | if ((rq->bio)) \ | ^~~~~~~~~ drivers/nvme/host/core.c:804:33: note: uninitialized use occurs here 804 | cmnd->copy.sdlba = cpu_to_le64(dst_lba); | ^~~~~~~ include/linux/byteorder/generic.h:86:21: note: expanded from macro 'cpu_to_le64' 86 | #define cpu_to_le64 __cpu_to_le64 | ^ include/uapi/linux/byteorder/little_endian.h:32:51: note: expanded from macro '__cpu_to_le64' 32 | #define __cpu_to_le64(x) ((__force __le64)(__u64)(x)) | ^ drivers/nvme/host/core.c:782:2: note: remove the 'if' if its condition is always true 782 | __rq_for_each_bio(bio, req) { | ^ include/linux/blk-mq.h:1008:2: note: expanded from macro '__rq_for_each_bio' 1008 | if ((rq->bio)) \ | ^ drivers/nvme/host/core.c:772:13: note: initialize the variable 'dst_lba' to silence this warning 772 | u64 dst_lba, src_lba, n_lba; | ^ | = 0 1 warning generated. vim +782 drivers/nvme/host/core.c 765 766 static inline blk_status_t nvme_setup_copy_offload(struct nvme_ns *ns, 767 struct request *req, 768 struct nvme_command *cmnd) 769 { 770 struct nvme_copy_range *range = NULL; 771 struct bio *bio; 772 u64 dst_lba, src_lba, n_lba; 773 u16 nr_range = 1, control = 0, seg = 1; 774 775 if (blk_rq_nr_phys_segments(req) != COPY_MAX_SEGMENTS) 776 return BLK_STS_IOERR; 777 778 /* 779 * First bio contains information about source and last bio contains 780 * information about destination. 781 */ > 782 __rq_for_each_bio(bio, req) { 783 if (seg == blk_rq_nr_phys_segments(req)) { 784 dst_lba = nvme_sect_to_lba(ns, bio->bi_iter.bi_sector); 785 if (n_lba != bio->bi_iter.bi_size >> ns->lba_shift) 786 return BLK_STS_IOERR; 787 } else { 788 src_lba = nvme_sect_to_lba(ns, bio->bi_iter.bi_sector); 789 n_lba = bio->bi_iter.bi_size >> ns->lba_shift; 790 } 791 seg++; 792 } 793 794 if (req->cmd_flags & REQ_FUA) 795 control |= NVME_RW_FUA; 796 797 if (req->cmd_flags & REQ_FAILFAST_DEV) 798 control |= NVME_RW_LR; 799 800 memset(cmnd, 0, sizeof(*cmnd)); 801 cmnd->copy.opcode = nvme_cmd_copy; 802 cmnd->copy.nsid = cpu_to_le32(ns->head->ns_id); 803 cmnd->copy.control = cpu_to_le16(control); 804 cmnd->copy.sdlba = cpu_to_le64(dst_lba); 805 cmnd->copy.nr_range = 0; 806 807 range = kmalloc_array(nr_range, sizeof(*range), 808 GFP_ATOMIC | __GFP_NOWARN); 809 if (!range) 810 return BLK_STS_RESOURCE; 811 812 range[0].slba = cpu_to_le64(src_lba); 813 range[0].nlb = cpu_to_le16(n_lba - 1); 814 815 req->special_vec.bv_page = virt_to_page(range); 816 req->special_vec.bv_offset = offset_in_page(range); 817 req->special_vec.bv_len = sizeof(*range) * nr_range; 818 req->rq_flags |= RQF_SPECIAL_PAYLOAD; 819 820 return BLK_STS_OK; 821 } 822 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki
