[22/26] xfs: don't coalesce file mappings that cross rtgroup boundaries in scrub

Commit Message

Darrick J. Wong Aug. 23, 2024, 12:26 a.m. UTC

From: Darrick J. Wong <[e-mail]>

The bmbt scrubber will combine file mappings if they are mergeable to
reduce the number of cross-referencing checks.  However, we shouldn't
combine mappings that cross rt group boundaries because that will cause
verifiers to trip incorrectly.

Signed-off-by: Darrick J. Wong <[e-mail]>
---
 fs/xfs/scrub/bmap.c |   16 +++++++++++++++-
 1 file changed, 15 insertions(+), 1 deletion(-)

Comments

Christoph Hellwig Aug. 23, 2024, 5:19 a.m. UTC | #1

Looks good:

Reviewed-by: Christoph Hellwig <[e-mail]>

Patch

diff --git a/fs/xfs/scrub/bmap.c b/fs/xfs/scrub/bmap.c
index 69dac1bd6a83e..173c371e822f5 100644
--- a/fs/xfs/scrub/bmap.c
+++ b/fs/xfs/scrub/bmap.c
@@ -835,9 +835,12 @@  xchk_bmap_iext_mapping(
 /* Are these two mappings contiguous with each other? */
 static inline bool
 xchk_are_bmaps_contiguous(
+	const struct xchk_bmap_info	*info,
 	const struct xfs_bmbt_irec	*b1,
 	const struct xfs_bmbt_irec	*b2)
 {
+	struct xfs_mount		*mp = info->sc->mp;
+
 	/* Don't try to combine unallocated mappings. */
 	if (!xfs_bmap_is_real_extent(b1))
 		return false;
@@ -851,6 +854,17 @@  xchk_are_bmaps_contiguous(
 		return false;
 	if (b1->br_state != b2->br_state)
 		return false;
+
+	/*
+	 * Don't combine bmaps that would cross rtgroup boundaries.  This is a
+	 * valid state, but if combined they will fail rtb extent checks.
+	 */
+	if (info->is_rt && xfs_has_rtgroups(mp)) {
+		if (xfs_rtb_to_rgno(mp, b1->br_startblock) !=
+		    xfs_rtb_to_rgno(mp, b2->br_startblock))
+			return false;
+	}
+
 	return true;
 }
 
@@ -888,7 +902,7 @@  xchk_bmap_iext_iter(
 	 * that we just read, if possible.
 	 */
 	while (xfs_iext_peek_next_extent(ifp, &info->icur, &got)) {
-		if (!xchk_are_bmaps_contiguous(irec, &got))
+		if (!xchk_are_bmaps_contiguous(info, irec, &got))
 			break;
 
 		if (!xchk_bmap_iext_mapping(info, &got)) {