xfs: verify AGF blocks as they are read from disk

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>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
This commit is contained in:
Dave Chinner 2012-11-14 17:44:56 +11:00 committed by Ben Myers
parent 98021821a5
commit 5d5f527d13

View file

@ -2091,6 +2091,47 @@ 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);
/*
* during growfs operations, the perag is not fully initialised,
* so we can't use it for any useful checking. growfs ensures we can't
* use it by using uncached buffers that don't have the perag attached
* so we can detect and avoid this problem.
*/
if (bp->b_pag)
agf_ok = agf_ok && 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(__func__, XFS_ERRLEVEL_LOW, mp, agf);
xfs_buf_ioerror(bp, EFSCORRUPTED);
}
bp->b_iodone = NULL;
xfs_buf_ioend(bp, 0);
}
/*
* Read in the allocation group header (free/alloc section).
*/
@ -2102,44 +2143,19 @@ xfs_read_agf(
int flags, /* XFS_BUF_ */
struct xfs_buf **bpp) /* buffer for the ag freelist header */
{
struct xfs_agf *agf; /* ag freelist header */
int agf_ok; /* set if agf is consistent */
int error;
ASSERT(agno != NULLAGNUMBER);
error = xfs_trans_read_buf(
mp, tp, mp->m_ddev_targp,
XFS_AG_DADDR(mp, agno, XFS_AGF_DADDR(mp)),
XFS_FSS_TO_BB(mp, 1), flags, bpp, NULL);
XFS_FSS_TO_BB(mp, 1), flags, bpp, xfs_agf_read_verify);
if (error)
return error;
if (!*bpp)
return 0;
ASSERT(!(*bpp)->b_error);
agf = XFS_BUF_TO_AGF(*bpp);
/*
* Validate the magic number of the agf block.
*/
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) == 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_trans_brelse(tp, *bpp);
return XFS_ERROR(EFSCORRUPTED);
}
xfs_buf_set_ref(*bpp, XFS_AGF_REF);
return 0;
}