[30/43] xfs: allow overlapping rtrmapbt records for shared data extents

Commit Message

Darrick J. Wong Dec. 19, 2024, 7:40 p.m. UTC

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

Allow overlapping realtime reverse mapping records if they both describe
shared data extents and the fs supports reflink on the realtime volume.

Signed-off-by: "Darrick J. Wong" <[e-mail]>
Reviewed-by: Christoph Hellwig <[e-mail]>
---
 fs/xfs/scrub/rtrmap.c |   17 ++++++++++++++++-
 1 file changed, 16 insertions(+), 1 deletion(-)

Patch

diff --git a/fs/xfs/scrub/rtrmap.c b/fs/xfs/scrub/rtrmap.c
index 3d5419682d6528..12989fe80e8bda 100644
--- a/fs/xfs/scrub/rtrmap.c
+++ b/fs/xfs/scrub/rtrmap.c
@@ -78,6 +78,18 @@  struct xchk_rtrmap {
 	struct xfs_rmap_irec	prev_rec;
 };
 
+static inline bool
+xchk_rtrmapbt_is_shareable(
+	struct xfs_scrub		*sc,
+	const struct xfs_rmap_irec	*irec)
+{
+	if (!xfs_has_rtreflink(sc->mp))
+		return false;
+	if (irec->rm_flags & XFS_RMAP_UNWRITTEN)
+		return false;
+	return true;
+}
+
 /* Flag failures for records that overlap but cannot. */
 STATIC void
 xchk_rtrmapbt_check_overlapping(
@@ -99,7 +111,10 @@  xchk_rtrmapbt_check_overlapping(
 	if (pnext <= irec->rm_startblock)
 		goto set_prev;
 
-	xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
+	/* Overlap is only allowed if both records are data fork mappings. */
+	if (!xchk_rtrmapbt_is_shareable(bs->sc, &cr->overlap_rec) ||
+	    !xchk_rtrmapbt_is_shareable(bs->sc, irec))
+		xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
 
 	/* Save whichever rmap record extends furthest. */
 	inext = irec->rm_startblock + irec->rm_blockcount;