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xfs: verify AGF blocks as they are read from disk

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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
1 changed files with 42 additions and 26 deletions
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68
fs/xfs/xfs_alloc.c
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@ -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;
}