From: "Darrick J. Wong" <darrick.wong@oracle.com> To: Zheng Bin <zhengbin13@huawei.com> Cc: sandeen@sandeen.net, bfoster@redhat.com, dchinner@redhat.com, linux-xfs@vger.kernel.org, renxudong1@huawei.com, yi.zhang@huawei.com Subject: Re: [PATCH v3] xfs: add agf freeblocks verify in xfs_agf_verify Date: Fri, 21 Feb 2020 07:38:03 -0800 [thread overview] Message-ID: <20200221153803.GP9506@magnolia> (raw) In-Reply-To: <1582260435-20939-1-git-send-email-zhengbin13@huawei.com> On Fri, Feb 21, 2020 at 12:47:15PM +0800, Zheng Bin wrote: > 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> Looks ok, will give this a run through fuzz testing... Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> --D > --- > > v1->v2: modify comment, add more agf verify > v2->v3: modify code which is suggested by hellwig & darrick > besides, remove the agf_freeblks < sb_fdblocks check, sb_fdblocks may not be true, > if we have lazysbcount or not umount clean. If we check this, we need to add > if ((!xfs_sb_version_haslazysbcount(&mp->m_sb) || > XFS_LAST_UNMOUNT_WAS_CLEAN(mp)) && > !xfs_fs_has_sickness(mp, XFS_SICK_FS_COUNTERS)) > like function xfs_check_summary_counts does. > > 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 d8053bc..183dc25 100644 > --- a/fs/xfs/libxfs/xfs_alloc.c > +++ b/fs/xfs/libxfs/xfs_alloc.c > @@ -2858,6 +2858,13 @@ xfs_agf_verify( > 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 || > @@ -2869,6 +2876,10 @@ xfs_agf_verify( > 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 > @@ -2883,6 +2894,11 @@ xfs_agf_verify( > 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; > -- > 2.7.4 >
next prev parent reply other threads:[~2020-02-21 15:38 UTC|newest] Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top 2020-02-21 4:47 Zheng Bin 2020-02-21 15:38 ` Darrick J. Wong [this message] 2020-02-29 11:21 ` zhengbin (A) 2020-02-29 17:00 ` Darrick J. Wong
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20200221153803.GP9506@magnolia \ --to=darrick.wong@oracle.com \ --cc=bfoster@redhat.com \ --cc=dchinner@redhat.com \ --cc=linux-xfs@vger.kernel.org \ --cc=renxudong1@huawei.com \ --cc=sandeen@sandeen.net \ --cc=yi.zhang@huawei.com \ --cc=zhengbin13@huawei.com \ --subject='Re: [PATCH v3] xfs: add agf freeblocks verify in xfs_agf_verify' \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: link
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).