Hi Johannes, kernel test robot noticed the following build warnings: https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Johannes-Thumshirn/btrfs-handle-bio_split-error/20241029-171227 base: https://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux.git for-next patch link: https://lore.kernel.org/r/20241029091121.16281-1-jth%40kernel.org patch subject: [PATCH] btrfs: handle bio_split() error config: openrisc-randconfig-r072-20241030 (https://download.01.org/0day-ci/archive/20241031/202410310231.WMcRwBhG-lkp@xxxxxxxxx/config) compiler: or1k-linux-gcc (GCC) 14.1.0 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> | Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> | Closes: https://lore.kernel.org/r/202410310231.WMcRwBhG-lkp@xxxxxxxxx/ smatch warnings: fs/btrfs/bio.c:763 btrfs_submit_chunk() error: 'bbio' dereferencing possible ERR_PTR() vim +/bbio +763 fs/btrfs/bio.c ae42a154ca8972 Christoph Hellwig 2023-03-07 660 static bool btrfs_submit_chunk(struct btrfs_bio *bbio, int mirror_num) 103c19723c80bf Christoph Hellwig 2022-11-15 661 { d5e4377d505189 Christoph Hellwig 2023-01-21 662 struct btrfs_inode *inode = bbio->inode; 4317ff0056bedf Qu Wenruo 2023-03-23 663 struct btrfs_fs_info *fs_info = bbio->fs_info; ae42a154ca8972 Christoph Hellwig 2023-03-07 664 struct bio *bio = &bbio->bio; adbe7e388e4239 Anand Jain 2023-04-15 665 u64 logical = bio->bi_iter.bi_sector << SECTOR_SHIFT; 103c19723c80bf Christoph Hellwig 2022-11-15 666 u64 length = bio->bi_iter.bi_size; 103c19723c80bf Christoph Hellwig 2022-11-15 667 u64 map_length = length; 921603c76246a7 Christoph Hellwig 2022-12-12 668 bool use_append = btrfs_use_zone_append(bbio); 103c19723c80bf Christoph Hellwig 2022-11-15 669 struct btrfs_io_context *bioc = NULL; 103c19723c80bf Christoph Hellwig 2022-11-15 670 struct btrfs_io_stripe smap; 9ba0004bd95e05 Christoph Hellwig 2023-01-21 671 blk_status_t ret; 9ba0004bd95e05 Christoph Hellwig 2023-01-21 672 int error; 103c19723c80bf Christoph Hellwig 2022-11-15 673 f4d39cf1cebfb8 Johannes Thumshirn 2024-07-31 674 if (!bbio->inode || btrfs_is_data_reloc_root(inode->root)) f4d39cf1cebfb8 Johannes Thumshirn 2024-07-31 675 smap.rst_search_commit_root = true; f4d39cf1cebfb8 Johannes Thumshirn 2024-07-31 676 else f4d39cf1cebfb8 Johannes Thumshirn 2024-07-31 677 smap.rst_search_commit_root = false; 9acaa64187f9b4 Johannes Thumshirn 2023-09-14 678 103c19723c80bf Christoph Hellwig 2022-11-15 679 btrfs_bio_counter_inc_blocked(fs_info); cd4efd210edfb3 Christoph Hellwig 2023-05-31 680 error = btrfs_map_block(fs_info, btrfs_op(bio), logical, &map_length, 9fb2acc2fe07f1 Qu Wenruo 2023-09-17 681 &bioc, &smap, &mirror_num); 9ba0004bd95e05 Christoph Hellwig 2023-01-21 682 if (error) { 9ba0004bd95e05 Christoph Hellwig 2023-01-21 683 ret = errno_to_blk_status(error); 9ba0004bd95e05 Christoph Hellwig 2023-01-21 684 goto fail; 103c19723c80bf Christoph Hellwig 2022-11-15 685 } 103c19723c80bf Christoph Hellwig 2022-11-15 686 852eee62d31abd Christoph Hellwig 2023-01-21 687 map_length = min(map_length, length); d5e4377d505189 Christoph Hellwig 2023-01-21 688 if (use_append) b35243a447b9fe Christoph Hellwig 2024-08-26 689 map_length = btrfs_append_map_length(bbio, map_length); d5e4377d505189 Christoph Hellwig 2023-01-21 690 103c19723c80bf Christoph Hellwig 2022-11-15 691 if (map_length < length) { b35243a447b9fe Christoph Hellwig 2024-08-26 692 bbio = btrfs_split_bio(fs_info, bbio, map_length); 28c02a018d50ae Johannes Thumshirn 2024-10-29 693 if (IS_ERR(bbio)) { 28c02a018d50ae Johannes Thumshirn 2024-10-29 694 ret = PTR_ERR(bbio); 28c02a018d50ae Johannes Thumshirn 2024-10-29 695 goto fail; We hit this goto. We know from the if statement that map_length < length. 28c02a018d50ae Johannes Thumshirn 2024-10-29 696 } 2cef0c79bb81d8 Christoph Hellwig 2023-03-07 697 bio = &bbio->bio; 103c19723c80bf Christoph Hellwig 2022-11-15 698 } 103c19723c80bf Christoph Hellwig 2022-11-15 699 1c2b3ee3b0ec4b Christoph Hellwig 2023-01-21 700 /* 1c2b3ee3b0ec4b Christoph Hellwig 2023-01-21 701 * Save the iter for the end_io handler and preload the checksums for 1c2b3ee3b0ec4b Christoph Hellwig 2023-01-21 702 * data reads. 1c2b3ee3b0ec4b Christoph Hellwig 2023-01-21 703 */ fbe960877b6f43 Christoph Hellwig 2023-05-31 704 if (bio_op(bio) == REQ_OP_READ && is_data_bbio(bbio)) { 0d3acb25e70d5f Christoph Hellwig 2023-01-21 705 bbio->saved_iter = bio->bi_iter; 1c2b3ee3b0ec4b Christoph Hellwig 2023-01-21 706 ret = btrfs_lookup_bio_sums(bbio); 1c2b3ee3b0ec4b Christoph Hellwig 2023-01-21 707 if (ret) 10d9d8c3512f16 Qu Wenruo 2024-08-17 708 goto fail; 1c2b3ee3b0ec4b Christoph Hellwig 2023-01-21 709 } 7276aa7d38255b Christoph Hellwig 2023-01-21 710 f8a53bb58ec7e2 Christoph Hellwig 2023-01-21 711 if (btrfs_op(bio) == BTRFS_MAP_WRITE) { d5e4377d505189 Christoph Hellwig 2023-01-21 712 if (use_append) { d5e4377d505189 Christoph Hellwig 2023-01-21 713 bio->bi_opf &= ~REQ_OP_WRITE; d5e4377d505189 Christoph Hellwig 2023-01-21 714 bio->bi_opf |= REQ_OP_ZONE_APPEND; 69ccf3f4244abc Christoph Hellwig 2023-01-21 715 } 69ccf3f4244abc Christoph Hellwig 2023-01-21 716 02c372e1f016e5 Johannes Thumshirn 2023-09-14 717 if (is_data_bbio(bbio) && bioc && 02c372e1f016e5 Johannes Thumshirn 2023-09-14 718 btrfs_need_stripe_tree_update(bioc->fs_info, bioc->map_type)) { 02c372e1f016e5 Johannes Thumshirn 2023-09-14 719 /* 02c372e1f016e5 Johannes Thumshirn 2023-09-14 720 * No locking for the list update, as we only add to 02c372e1f016e5 Johannes Thumshirn 2023-09-14 721 * the list in the I/O submission path, and list 02c372e1f016e5 Johannes Thumshirn 2023-09-14 722 * iteration only happens in the completion path, which 02c372e1f016e5 Johannes Thumshirn 2023-09-14 723 * can't happen until after the last submission. 02c372e1f016e5 Johannes Thumshirn 2023-09-14 724 */ 02c372e1f016e5 Johannes Thumshirn 2023-09-14 725 btrfs_get_bioc(bioc); 02c372e1f016e5 Johannes Thumshirn 2023-09-14 726 list_add_tail(&bioc->rst_ordered_entry, &bbio->ordered->bioc_list); 02c372e1f016e5 Johannes Thumshirn 2023-09-14 727 } 02c372e1f016e5 Johannes Thumshirn 2023-09-14 728 f8a53bb58ec7e2 Christoph Hellwig 2023-01-21 729 /* f8a53bb58ec7e2 Christoph Hellwig 2023-01-21 730 * Csum items for reloc roots have already been cloned at this f8a53bb58ec7e2 Christoph Hellwig 2023-01-21 731 * point, so they are handled as part of the no-checksum case. f8a53bb58ec7e2 Christoph Hellwig 2023-01-21 732 */ 4317ff0056bedf Qu Wenruo 2023-03-23 733 if (inode && !(inode->flags & BTRFS_INODE_NODATASUM) && 169aaaf2e0be61 Qu Wenruo 2024-06-14 734 !test_bit(BTRFS_FS_STATE_NO_DATA_CSUMS, &fs_info->fs_state) && d5e4377d505189 Christoph Hellwig 2023-01-21 735 !btrfs_is_data_reloc_root(inode->root)) { f8a53bb58ec7e2 Christoph Hellwig 2023-01-21 736 if (should_async_write(bbio) && f8a53bb58ec7e2 Christoph Hellwig 2023-01-21 737 btrfs_wq_submit_bio(bbio, bioc, &smap, mirror_num)) 852eee62d31abd Christoph Hellwig 2023-01-21 738 goto done; 103c19723c80bf Christoph Hellwig 2022-11-15 739 f8a53bb58ec7e2 Christoph Hellwig 2023-01-21 740 ret = btrfs_bio_csum(bbio); f8a53bb58ec7e2 Christoph Hellwig 2023-01-21 741 if (ret) 10d9d8c3512f16 Qu Wenruo 2024-08-17 742 goto fail; cebae292e0c32a Johannes Thumshirn 2024-06-07 743 } else if (use_append || cebae292e0c32a Johannes Thumshirn 2024-06-07 744 (btrfs_is_zoned(fs_info) && inode && cebae292e0c32a Johannes Thumshirn 2024-06-07 745 inode->flags & BTRFS_INODE_NODATASUM)) { cbfce4c7fbde23 Christoph Hellwig 2023-05-24 746 ret = btrfs_alloc_dummy_sum(bbio); cbfce4c7fbde23 Christoph Hellwig 2023-05-24 747 if (ret) 10d9d8c3512f16 Qu Wenruo 2024-08-17 748 goto fail; f8a53bb58ec7e2 Christoph Hellwig 2023-01-21 749 } 103c19723c80bf Christoph Hellwig 2022-11-15 750 } f8a53bb58ec7e2 Christoph Hellwig 2023-01-21 751 22b4ef50dc1d11 David Sterba 2024-08-27 752 btrfs_submit_bio(bio, bioc, &smap, mirror_num); 852eee62d31abd Christoph Hellwig 2023-01-21 753 done: 852eee62d31abd Christoph Hellwig 2023-01-21 754 return map_length == length; 9ba0004bd95e05 Christoph Hellwig 2023-01-21 755 9ba0004bd95e05 Christoph Hellwig 2023-01-21 756 fail: 9ba0004bd95e05 Christoph Hellwig 2023-01-21 757 btrfs_bio_counter_dec(fs_info); 10d9d8c3512f16 Qu Wenruo 2024-08-17 758 /* 10d9d8c3512f16 Qu Wenruo 2024-08-17 759 * We have split the original bbio, now we have to end both the current 10d9d8c3512f16 Qu Wenruo 2024-08-17 760 * @bbio and remaining one, as the remaining one will never be submitted. 10d9d8c3512f16 Qu Wenruo 2024-08-17 761 */ 10d9d8c3512f16 Qu Wenruo 2024-08-17 762 if (map_length < length) { 10d9d8c3512f16 Qu Wenruo 2024-08-17 @763 struct btrfs_bio *remaining = bbio->private; ^^^^^^^^^^^^^ Error pointer dereference 10d9d8c3512f16 Qu Wenruo 2024-08-17 764 10d9d8c3512f16 Qu Wenruo 2024-08-17 765 ASSERT(bbio->bio.bi_pool == &btrfs_clone_bioset); 10d9d8c3512f16 Qu Wenruo 2024-08-17 766 ASSERT(remaining); 10d9d8c3512f16 Qu Wenruo 2024-08-17 767 9ca0e58cb752b0 Qu Wenruo 2024-08-24 768 btrfs_bio_end_io(remaining, ret); 10d9d8c3512f16 Qu Wenruo 2024-08-17 769 } 9ca0e58cb752b0 Qu Wenruo 2024-08-24 770 btrfs_bio_end_io(bbio, ret); 852eee62d31abd Christoph Hellwig 2023-01-21 771 /* Do not submit another chunk */ 852eee62d31abd Christoph Hellwig 2023-01-21 772 return true; 852eee62d31abd Christoph Hellwig 2023-01-21 773 } -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki