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

[Phil White]

On Thu, Oct 25, 2012 at 05:33:55PM +1100, Dave Chinner wrote:
> From: Dave Chinner <dchinner at 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 at redhat.com>
> Reviewed-by: Christoph Hellwig <hch at 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