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authorDave Chinner <dchinner@redhat.com>2012-11-14 17:44:56 +1100
committerBen Myers <bpm@sgi.com>2012-11-15 21:34:10 -0600
commit5d5f527d13369d0047d52b7ac4ddee4f8c0ad173 (patch)
treebe5aa9ed00828ca05ace198a78eed422a5627cc1 /fs/xfs
parent98021821a502db347bd9c7671beeee6e8ce07ea6 (diff)
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>
Diffstat (limited to 'fs/xfs')
-rw-r--r--fs/xfs/xfs_alloc.c68
1 files changed, 42 insertions, 26 deletions
diff --git a/fs/xfs/xfs_alloc.c b/fs/xfs/xfs_alloc.c
index 21c3db08fd0..c9eb955a49c 100644
--- a/fs/xfs/xfs_alloc.c
+++ b/fs/xfs/xfs_alloc.c
@@ -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;
}