Re: [PATCH 06/25] xfs: verify AGF blocks as they are read from disk

Phil White
2012-10-30T17:56:19Z

On Thu, Oct 25, 2012 at 05:33:55PM +1100, Dave Chinner wrote:
> From: Dave Chinner <dchinner@redhat.com>
>
> Add an AGF block verify callback function and pass it into the
> buffer read functions. This replaces the existing verification that
> is done after the read completes.
>
> Signed-off-by: Dave Chinner <dchinner@redhat.com>
> Reviewed-by: Christoph Hellwig <hch@lst.de>
> ---
> fs/xfs/xfs_alloc.c | 60 +++++++++++++++++++++++++++++-----------------------
> 1 file changed, 34 insertions(+), 26 deletions(-)
>
> diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c
> index 21c3db0..bd565a2 100644
> --- a/fs/xfs/xfs_alloc.c
> +++ b/fs/xfs/xfs_alloc.c
> @@ -2091,6 +2091,39 @@ xfs_alloc_put_freelist(
> return 0;
> }
>
> +static void
> +xfs_agf_read_verify(
> + struct xfs_buf *bp)
> + {
> + struct xfs_mount *mp = bp->b_target->bt_mount;
> + struct xfs_agf *agf;
> + int agf_ok;
> +
> + agf = XFS_BUF_TO_AGF(bp);
> +
> + agf_ok = agf->agf_magicnum == cpu_to_be32(XFS_AGF_MAGIC) &&
> + XFS_AGF_GOOD_VERSION(be32_to_cpu(agf->agf_versionnum)) &&
> + be32_to_cpu(agf->agf_freeblks) <= be32_to_cpu(agf->agf_length) &&
> + be32_to_cpu(agf->agf_flfirst) < XFS_AGFL_SIZE(mp) &&
> + be32_to_cpu(agf->agf_fllast) < XFS_AGFL_SIZE(mp) &&
> + be32_to_cpu(agf->agf_flcount) <= XFS_AGFL_SIZE(mp) &&
> + be32_to_cpu(agf->agf_seqno) == bp->b_pag->pag_agno;
> +
> + if (xfs_sb_version_haslazysbcount(&mp->m_sb))
> + agf_ok = agf_ok && be32_to_cpu(agf->agf_btreeblks) <=
> + be32_to_cpu(agf->agf_length);
> +
> + if (unlikely(XFS_TEST_ERROR(!agf_ok, mp, XFS_ERRTAG_ALLOC_READ_AGF,
> + XFS_RANDOM_ALLOC_READ_AGF))) {
> + XFS_CORRUPTION_ERROR("xfs_alloc_read_agf",
> + XFS_ERRLEVEL_LOW, mp, agf);
> + xfs_buf_ioerror(bp, EFSCORRUPTED);
> + }

Shouldn't this be XFS_CORRUPTION_ERROR("xfs_agf_read_verify", ...) ?

-Phil