[PATCH 19/26] xfs: don't cross reference rmapbt with bitmaps if they're incomplete

[Eduard Zateev <hackerowskiy@gmail.com>]

From: "Darrick J. Wong" <djwong@kernel.org>

LOLLM points out that runtime errors (e.g. ENOMEM) when we're trying to
compute space usag bitmaps are silently dropped by the rmapbt scrubber.
We ought to flag that as an incomplete scrub instead of reporting
cross-referencing errors based on faulty data.

Cc: stable@vger.kernel.org # v6.4
Fixes: fed050f3452da0 ("xfs: cross-reference rmap records with ag btrees")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Assisted-by: LOLLM # finding obvious bugs
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Carlos Maiolino <cem@kernel.org>
---
 fs/xfs/scrub/rmap.c | 20 ++++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/fs/xfs/scrub/rmap.c b/fs/xfs/scrub/rmap.c
index 0cd3eecd2ca5..68e2847c962b 100644
--- a/fs/xfs/scrub/rmap.c
+++ b/fs/xfs/scrub/rmap.c
@@ -493,11 +493,18 @@ xchk_rmapbt_walk_ag_metadata(
 	 * If there's an error, set XFAIL and disable the bitmap
 	 * cross-referencing checks, but proceed with the scrub anyway.
 	 */
-	if (error)
-		xchk_btree_xref_process_error(sc, sc->sa.rmap_cur,
-				sc->sa.rmap_cur->bc_nlevels - 1, &error);
-	else
-		cr->bitmaps_complete = true;
+	if (error) {
+		if (!xchk_btree_xref_process_error(sc, sc->sa.rmap_cur,
+				sc->sa.rmap_cur->bc_nlevels - 1, &error)) {
+			/* only set incomplete if we didn't set xfail */
+			if (error)
+				xchk_set_incomplete(sc);
+		}
+
+		return 0;
+	}
+
+	cr->bitmaps_complete = true;
 	return 0;
 }
 
@@ -567,7 +574,8 @@ xchk_rmapbt(
 	if (error)
 		goto out;
 
-	xchk_rmapbt_check_bitmaps(sc, cr);
+	if (cr->bitmaps_complete)
+		xchk_rmapbt_check_bitmaps(sc, cr);
 
 out:
 	xagb_bitmap_destroy(&cr->refcbt_owned);
-- 
2.55.0