From: Eric Sandeen <sandeen@sandeen.net>
To: Zheng Bin <zhengbin13@huawei.com>,
david@fromorbit.com, darrick.wong@oracle.com, sandeen@redhat.com,
linux-xfs@vger.kernel.org
Cc: renxudong1@huawei.com
Subject: Re: [PATCH] xfs: add agf freeblocks verify in xfs_agf_verify
Date: Thu, 13 Feb 2020 07:37:54 -0600 [thread overview]
Message-ID: <2ecaa8ec-cef0-4174-13ad-89288e1cc55e@sandeen.net> (raw)
In-Reply-To: <1581587639-130771-1-git-send-email-zhengbin13@huawei.com>
On 2/13/20 3:53 AM, Zheng Bin wrote:
> We recently used fuzz(hydra) to test XFS and automatically generate
> tmp.img(XFS v5 format, but some metadata is wrong)
>
> Test as follows:
> mount tmp.img tmpdir
> cp file1M tmpdir
> sync
I would leave this part out of the change log, because it is not a
useful testcase for anyone who does not have your test.img.
> tmpdir/file1M size is 1M, but its data can not sync to disk.
>
> This is because tmp.img has some problems, using xfs_repair detect
> information as follows:
>
> agf_freeblks 0, counted 3224 in ag 0
> agf_longest 536874136, counted 3224 in ag 0
> sb_fdblocks 613, counted 3228
>
> Add these agf freeblocks checks:
> 1. agf_longest < agf_freeblks
> 2. agf_freeblks < sb_fdblocks
This left out the 2nd check Dave suggested, that freeblocks is
less than the number of blocks in the AG, i.e.
b) agf_freeblks < sb_dblocks / sb_agcount
(and yes, it must special-case the last AG which may be smaller - see
xfs_ag_block_count())
-Eric
> Signed-off-by: Zheng Bin <zhengbin13@huawei.com>
> Signed-off-by: Ren Xudong <renxudong1@huawei.com>
> ---
> fs/xfs/libxfs/xfs_alloc.c | 4 ++++
> 1 file changed, 4 insertions(+)
>
> diff --git a/fs/xfs/libxfs/xfs_alloc.c b/fs/xfs/libxfs/xfs_alloc.c
> index d8053bc..0f4b4d1 100644
> --- a/fs/xfs/libxfs/xfs_alloc.c
> +++ b/fs/xfs/libxfs/xfs_alloc.c
> @@ -2858,6 +2858,10 @@ xfs_agf_verify(
> be32_to_cpu(agf->agf_flcount) <= xfs_agfl_size(mp)))
> return __this_address;
>
> + if (be32_to_cpu(agf->agf_freeblks) < be32_to_cpu(agf->agf_longest) ||
> + be32_to_cpu(agf->agf_freeblks) >= mp->m_sb.sb_fdblocks)
> + 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 ||
> --
> 2.7.4
>
next prev parent reply other threads:[~2020-02-13 13:37 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-13 9:53 [PATCH] xfs: add agf freeblocks verify in xfs_agf_verify Zheng Bin
2020-02-13 13:37 ` Eric Sandeen [this message]
2020-02-13 17:44 ` Darrick J. Wong
2020-02-13 20:55 ` Dave Chinner
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