On Thu, Aug 17, 2017 at 04:31:29PM -0700, Darrick J. Wong wrote:
> Hi all,
>
> This RFC combines all the random little fixes and improvements to the
> verifiers that we've been talking about for the past month or so into a
> single patch series!
>
> We start by refactoring the long format btree block header verifier into
> a single helper functionn and de-macroing dir block verifiers to make
> them less shouty. Next, we change verifier functions to return the
> approximate instruction pointer of the faulting test so that we can
> report more precise fault information to dmesg/tracepoints.
Just jumping here quickly because I don't have time for a detailed
review:
How good does this instruction pointer thing resolved to the actual
issue? I'm currently watching a customer issue where a write verifier
triggers, and I gave them a patch to add a debug print to every failing
statement, including printing out the mismatch values if it's not
simply a binary comparism. I though about preparing that patch as
well as others for mainline. Here is the one I have at the moment:
---
>From 6c5e2efc6f857228461d439feb3c98be58fb9744 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@xxxxxx>
Date: Sat, 5 Aug 2017 16:34:15 +0200
Subject: xfs: print verbose information on dir leaf verifier failures
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
fs/xfs/libxfs/xfs_dir2_leaf.c | 33 ++++++++++++++++++++++++++-------
1 file changed, 26 insertions(+), 7 deletions(-)
diff --git a/fs/xfs/libxfs/xfs_dir2_leaf.c b/fs/xfs/libxfs/xfs_dir2_leaf.c
index b887fb2a2bcf..4386c68f72c6 100644
--- a/fs/xfs/libxfs/xfs_dir2_leaf.c
+++ b/fs/xfs/libxfs/xfs_dir2_leaf.c
@@ -113,27 +113,37 @@ xfs_dir3_leaf_check_int(
* Should factor in the size of the bests table as well.
* We can deduce a value for that from di_size.
*/
- if (hdr->count > ops->leaf_max_ents(geo))
+ if (hdr->count > ops->leaf_max_ents(geo)) {
+ xfs_warn(mp, "count (%d) above max (%d)\n",
+ hdr->count, ops->leaf_max_ents(geo));
return false;
+ }
/* Leaves and bests don't overlap in leaf format. */
if ((hdr->magic == XFS_DIR2_LEAF1_MAGIC ||
hdr->magic == XFS_DIR3_LEAF1_MAGIC) &&
- (char *)&ents[hdr->count] > (char *)xfs_dir2_leaf_bests_p(ltp))
+ (char *)&ents[hdr->count] > (char *)xfs_dir2_leaf_bests_p(ltp)) {
+ xfs_warn(mp, "ents overlappings bests\n");
return false;
+ }
/* Check hash value order, count stale entries. */
for (i = stale = 0; i < hdr->count; i++) {
if (i + 1 < hdr->count) {
if (be32_to_cpu(ents[i].hashval) >
- be32_to_cpu(ents[i + 1].hashval))
+ be32_to_cpu(ents[i + 1].hashval)) {
+ xfs_warn(mp, "broken hash order\n");
return false;
+ }
}
if (ents[i].address == cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
stale++;
}
- if (hdr->stale != stale)
+ if (hdr->stale != stale) {
+ xfs_warn(mp, "incorrect stalte count (%d, expected %d)\n",
+ hdr->stale, stale);
return false;
+ }
return true;
}
@@ -159,12 +169,21 @@ xfs_dir3_leaf_verify(
magic3 = (magic == XFS_DIR2_LEAF1_MAGIC) ? XFS_DIR3_LEAF1_MAGIC
: XFS_DIR3_LEAFN_MAGIC;
- if (leaf3->info.hdr.magic != cpu_to_be16(magic3))
+ if (leaf3->info.hdr.magic != cpu_to_be16(magic3)) {
+ xfs_warn(mp, "incorrect magic number (0x%hx, expected 0x%hx)\n",
+ leaf3->info.hdr.magic, magic3);
return false;
- if (!uuid_equal(&leaf3->info.uuid, &mp->m_sb.sb_meta_uuid))
+ }
+ if (!uuid_equal(&leaf3->info.uuid, &mp->m_sb.sb_meta_uuid)) {
+ xfs_warn(mp, "incorrect uuid, (%pUb, expected %pUb)\n",
+ &leaf3->info.uuid, &mp->m_sb.sb_meta_uuid);
return false;
- if (be64_to_cpu(leaf3->info.blkno) != bp->b_bn)
+ }
+ if (be64_to_cpu(leaf3->info.blkno) != bp->b_bn) {
+ xfs_warn(mp, "incorrect blkno, (%lld, expected %lld)\n",
+ be64_to_cpu(leaf3->info.blkno), bp->b_bn);
return false;
+ }
if (!xfs_log_check_lsn(mp, be64_to_cpu(leaf3->info.lsn)))
return false;
} else {
--
2.11.0
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