From: Zheng Bin <zhengbin13@huawei.com> mainline inclusion from mainline-v5.6 commit d0c7feaf87678371c2c09b3709400be416b2dc62 category: bugfix bugzilla: 30215 CVE: NA --------------------------- We recently used fuzz(hydra) to test XFS and automatically generate tmp.img(XFS v5 format, but some metadata is wrong) xfs_repair information(just one AG): agf_freeblks 0, counted 3224 in ag 0 agf_longest 536874136, counted 3224 in ag 0 sb_fdblocks 613, counted 3228 Test as follows: mount tmp.img tmpdir cp file1M tmpdir sync In 4.19-stable, sync will stuck, the reason is: xfs_mountfs xfs_check_summary_counts if ((!xfs_sb_version_haslazysbcount(&mp->m_sb) || XFS_LAST_UNMOUNT_WAS_CLEAN(mp)) && !xfs_fs_has_sickness(mp, XFS_SICK_FS_COUNTERS)) return 0; -->just return, incore sb_fdblocks still be 613 xfs_initialize_perag_data cp file1M tmpdir -->ok(write file to pagecache) sync -->stuck(write pagecache to disk) xfs_map_blocks xfs_iomap_write_allocate while (count_fsb != 0) { nimaps = 0; while (nimaps == 0) { --> endless loop nimaps = 1; xfs_bmapi_write(..., &nimaps) --> nimaps becomes 0 again xfs_bmapi_write xfs_bmap_alloc xfs_bmap_btalloc xfs_alloc_vextent xfs_alloc_fix_freelist xfs_alloc_space_available -->fail(agf_freeblks is 0) In linux-next, sync not stuck, cause commit c2b3164320b5 ("xfs: use the latest extent at writeback delalloc conversion time") remove the above while, dmesg is as follows: [ 55.250114] XFS (loop0): page discard on page ffffea0008bc7380, inode 0x1b0c, offset 0. Users do not know why this page is discard, the better soultion is: 1. Like xfs_repair, make sure sb_fdblocks is equal to counted (xfs_initialize_perag_data did this, who is not called at this mount) 2. Add agf verify, if fail, will tell users to repair This patch use the second soultion. Signed-off-by: Zheng Bin <zhengbin13@huawei.com> Signed-off-by: Ren Xudong <renxudong1@huawei.com> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Zheng Bin <zhengbin13@huawei.com> Reviewed-by: zhangyi (F) <yi.zhang@huawei.com> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- fs/xfs/libxfs/xfs_alloc.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c index 4be387d..4ec8235 100644 --- a/fs/xfs/libxfs/xfs_alloc.c +++ b/fs/xfs/libxfs/xfs_alloc.c @@ -2596,6 +2596,13 @@ STATIC int xfs_alloc_ag_vextent_small(xfs_alloc_arg_t *, be32_to_cpu(agf->agf_flcount) <= xfs_agfl_size(mp))) return __this_address; + if (be32_to_cpu(agf->agf_length) > mp->m_sb.sb_dblocks) + return __this_address; + + if (be32_to_cpu(agf->agf_freeblks) < be32_to_cpu(agf->agf_longest) || + be32_to_cpu(agf->agf_freeblks) > be32_to_cpu(agf->agf_length)) + return __this_address; + if (be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]) < 1 || be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]) < 1 || be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]) > XFS_BTREE_MAXLEVELS || @@ -2607,6 +2614,10 @@ STATIC int xfs_alloc_ag_vextent_small(xfs_alloc_arg_t *, be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]) > XFS_BTREE_MAXLEVELS)) return __this_address; + if (xfs_sb_version_hasrmapbt(&mp->m_sb) && + be32_to_cpu(agf->agf_rmap_blocks) > be32_to_cpu(agf->agf_length)) + return __this_address; + /* * during growfs operations, the perag is not fully initialised, * so we can't use it for any useful checking. growfs ensures we can't @@ -2621,6 +2632,11 @@ STATIC int xfs_alloc_ag_vextent_small(xfs_alloc_arg_t *, return __this_address; if (xfs_sb_version_hasreflink(&mp->m_sb) && + be32_to_cpu(agf->agf_refcount_blocks) > + be32_to_cpu(agf->agf_length)) + return __this_address; + + if (xfs_sb_version_hasreflink(&mp->m_sb) && (be32_to_cpu(agf->agf_refcount_level) < 1 || be32_to_cpu(agf->agf_refcount_level) > XFS_BTREE_MAXLEVELS)) return __this_address; -- 1.8.3