[PATCH 06/16] xfs_repair: fix rmapbt record order check

Darrick J. Wong
2020-05-09T16:30:39Z

From: Darrick J. Wong <darrick.wong@oracle.com>

The rmapbt record order checks here don't quite work properly. For
non-shared filesystems, we fail to check that the startblock of the nth
record comes entirely after the previous record.

However, for filesystems with shared blocks (reflink) we correctly check
that the startblock/owner/offset of the nth record comes after the
previous one.

Therefore, make the reflink fs checks use "laststartblock" to preserve
that functionality while making the non-reflink fs checks use
"lastblock" to fix the problem outlined above.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
repair/scan.c | 12 +++++++-----
1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/repair/scan.c b/repair/scan.c
index 7c46ab89..7508f7e8 100644
--- a/repair/scan.c
+++ b/repair/scan.c
@@ -925,15 +925,15 @@ struct rmap_priv {
static bool
rmap_in_order(
xfs_agblock_t b,
- xfs_agblock_t lastblock,
+ xfs_agblock_t laststartblock,
uint64_t owner,
uint64_t lastowner,
uint64_t offset,
uint64_t lastoffset)
{
- if (b > lastblock)
+ if (b > laststartblock)
return true;
- else if (b < lastblock)
+ else if (b < laststartblock)
return false;

if (owner > lastowner)
@@ -964,6 +964,7 @@ scan_rmapbt(
int hdr_errors = 0;
int numrecs;
int state;
+ xfs_agblock_t laststartblock = 0;
xfs_agblock_t lastblock = 0;
uint64_t lastowner = 0;
uint64_t lastoffset = 0;
@@ -1101,14 +1102,15 @@ _("%s rmap btree block claimed (state %d), agno %d, bno %d, suspect %d\n"),
/* Check for out of order records. */
if (i == 0) {
advance:
- lastblock = b;
+ laststartblock = b;
+ lastblock = end - 1;
lastowner = owner;
lastoffset = offset;
} else {
bool bad;

if (xfs_sb_version_hasreflink(&mp->m_sb))
- bad = !rmap_in_order(b, lastblock,
+ bad = !rmap_in_order(b, laststartblock,
owner, lastowner,
offset, lastoffset);
else