Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 639 insertions, 0 deletions

diff --git a/fs/xfs/scrub/rmap.c b/fs/xfs/scrub/rmap.c
new file mode 100644
index 0000000000..d29a26ecdd
--- /dev/null
+++ b/fs/xfs/scrub/rmap.c
@@ -0,0 +1,639 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2017-2023 Oracle.  All Rights Reserved.
+ * Author: Darrick J. Wong <djwong@kernel.org>
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_log_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_mount.h"
+#include "xfs_trans.h"
+#include "xfs_btree.h"
+#include "xfs_rmap.h"
+#include "xfs_refcount.h"
+#include "xfs_ag.h"
+#include "xfs_bit.h"
+#include "xfs_alloc.h"
+#include "xfs_alloc_btree.h"
+#include "xfs_ialloc_btree.h"
+#include "xfs_refcount_btree.h"
+#include "scrub/scrub.h"
+#include "scrub/common.h"
+#include "scrub/btree.h"
+#include "scrub/bitmap.h"
+
+/*
+ * Set us up to scrub reverse mapping btrees.
+ */
+int
+xchk_setup_ag_rmapbt(
+	struct xfs_scrub	*sc)
+{
+	if (xchk_need_intent_drain(sc))
+		xchk_fsgates_enable(sc, XCHK_FSGATES_DRAIN);
+
+	return xchk_setup_ag_btree(sc, false);
+}
+
+/* Reverse-mapping scrubber. */
+
+struct xchk_rmap {
+	/*
+	 * The furthest-reaching of the rmapbt records that we've already
+	 * processed.  This enables us to detect overlapping records for space
+	 * allocations that cannot be shared.
+	 */
+	struct xfs_rmap_irec	overlap_rec;
+
+	/*
+	 * The previous rmapbt record, so that we can check for two records
+	 * that could be one.
+	 */
+	struct xfs_rmap_irec	prev_rec;
+
+	/* Bitmaps containing all blocks for each type of AG metadata. */
+	struct xagb_bitmap	fs_owned;
+	struct xagb_bitmap	log_owned;
+	struct xagb_bitmap	ag_owned;
+	struct xagb_bitmap	inobt_owned;
+	struct xagb_bitmap	refcbt_owned;
+
+	/* Did we complete the AG space metadata bitmaps? */
+	bool			bitmaps_complete;
+};
+
+/* Cross-reference a rmap against the refcount btree. */
+STATIC void
+xchk_rmapbt_xref_refc(
+	struct xfs_scrub	*sc,
+	struct xfs_rmap_irec	*irec)
+{
+	xfs_agblock_t		fbno;
+	xfs_extlen_t		flen;
+	bool			non_inode;
+	bool			is_bmbt;
+	bool			is_attr;
+	bool			is_unwritten;
+	int			error;
+
+	if (!sc->sa.refc_cur || xchk_skip_xref(sc->sm))
+		return;
+
+	non_inode = XFS_RMAP_NON_INODE_OWNER(irec->rm_owner);
+	is_bmbt = irec->rm_flags & XFS_RMAP_BMBT_BLOCK;
+	is_attr = irec->rm_flags & XFS_RMAP_ATTR_FORK;
+	is_unwritten = irec->rm_flags & XFS_RMAP_UNWRITTEN;
+
+	/* If this is shared, must be a data fork extent. */
+	error = xfs_refcount_find_shared(sc->sa.refc_cur, irec->rm_startblock,
+			irec->rm_blockcount, &fbno, &flen, false);
+	if (!xchk_should_check_xref(sc, &error, &sc->sa.refc_cur))
+		return;
+	if (flen != 0 && (non_inode || is_attr || is_bmbt || is_unwritten))
+		xchk_btree_xref_set_corrupt(sc, sc->sa.refc_cur, 0);
+}
+
+/* Cross-reference with the other btrees. */
+STATIC void
+xchk_rmapbt_xref(
+	struct xfs_scrub	*sc,
+	struct xfs_rmap_irec	*irec)
+{
+	xfs_agblock_t		agbno = irec->rm_startblock;
+	xfs_extlen_t		len = irec->rm_blockcount;
+
+	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+		return;
+
+	xchk_xref_is_used_space(sc, agbno, len);
+	if (irec->rm_owner == XFS_RMAP_OWN_INODES)
+		xchk_xref_is_inode_chunk(sc, agbno, len);
+	else
+		xchk_xref_is_not_inode_chunk(sc, agbno, len);
+	if (irec->rm_owner == XFS_RMAP_OWN_COW)
+		xchk_xref_is_cow_staging(sc, irec->rm_startblock,
+				irec->rm_blockcount);
+	else
+		xchk_rmapbt_xref_refc(sc, irec);
+}
+
+/*
+ * Check for bogus UNWRITTEN flags in the rmapbt node block keys.
+ *
+ * In reverse mapping records, the file mapping extent state
+ * (XFS_RMAP_OFF_UNWRITTEN) is a record attribute, not a key field.  It is not
+ * involved in lookups in any way.  In older kernels, the functions that
+ * convert rmapbt records to keys forgot to filter out the extent state bit,
+ * even though the key comparison functions have filtered the flag correctly.
+ * If we spot an rmap key with the unwritten bit set in rm_offset, we should
+ * mark the btree as needing optimization to rebuild the btree without those
+ * flags.
+ */
+STATIC void
+xchk_rmapbt_check_unwritten_in_keyflags(
+	struct xchk_btree	*bs)
+{
+	struct xfs_scrub	*sc = bs->sc;
+	struct xfs_btree_cur	*cur = bs->cur;
+	struct xfs_btree_block	*keyblock;
+	union xfs_btree_key	*lkey, *hkey;
+	__be64			badflag = cpu_to_be64(XFS_RMAP_OFF_UNWRITTEN);
+	unsigned int		level;
+
+	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_PREEN)
+		return;
+
+	for (level = 1; level < cur->bc_nlevels; level++) {
+		struct xfs_buf	*bp;
+		unsigned int	ptr;
+
+		/* Only check the first time we've seen this node block. */
+		if (cur->bc_levels[level].ptr > 1)
+			continue;
+
+		keyblock = xfs_btree_get_block(cur, level, &bp);
+		for (ptr = 1; ptr <= be16_to_cpu(keyblock->bb_numrecs); ptr++) {
+			lkey = xfs_btree_key_addr(cur, ptr, keyblock);
+
+			if (lkey->rmap.rm_offset & badflag) {
+				xchk_btree_set_preen(sc, cur, level);
+				break;
+			}
+
+			hkey = xfs_btree_high_key_addr(cur, ptr, keyblock);
+			if (hkey->rmap.rm_offset & badflag) {
+				xchk_btree_set_preen(sc, cur, level);
+				break;
+			}
+		}
+	}
+}
+
+static inline bool
+xchk_rmapbt_is_shareable(
+	struct xfs_scrub		*sc,
+	const struct xfs_rmap_irec	*irec)
+{
+	if (!xfs_has_reflink(sc->mp))
+		return false;
+	if (XFS_RMAP_NON_INODE_OWNER(irec->rm_owner))
+		return false;
+	if (irec->rm_flags & (XFS_RMAP_BMBT_BLOCK | XFS_RMAP_ATTR_FORK |
+			      XFS_RMAP_UNWRITTEN))
+		return false;
+	return true;
+}
+
+/* Flag failures for records that overlap but cannot. */
+STATIC void
+xchk_rmapbt_check_overlapping(
+	struct xchk_btree		*bs,
+	struct xchk_rmap		*cr,
+	const struct xfs_rmap_irec	*irec)
+{
+	xfs_agblock_t			pnext, inext;
+
+	if (bs->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+		return;
+
+	/* No previous record? */
+	if (cr->overlap_rec.rm_blockcount == 0)
+		goto set_prev;
+
+	/* Do overlap_rec and irec overlap? */
+	pnext = cr->overlap_rec.rm_startblock + cr->overlap_rec.rm_blockcount;
+	if (pnext <= irec->rm_startblock)
+		goto set_prev;
+
+	/* Overlap is only allowed if both records are data fork mappings. */
+	if (!xchk_rmapbt_is_shareable(bs->sc, &cr->overlap_rec) ||
+	    !xchk_rmapbt_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;
+	if (pnext > inext)
+		return;
+
+set_prev:
+	memcpy(&cr->overlap_rec, irec, sizeof(struct xfs_rmap_irec));
+}
+
+/* Decide if two reverse-mapping records can be merged. */
+static inline bool
+xchk_rmap_mergeable(
+	struct xchk_rmap		*cr,
+	const struct xfs_rmap_irec	*r2)
+{
+	const struct xfs_rmap_irec	*r1 = &cr->prev_rec;
+
+	/* Ignore if prev_rec is not yet initialized. */
+	if (cr->prev_rec.rm_blockcount == 0)
+		return false;
+
+	if (r1->rm_owner != r2->rm_owner)
+		return false;
+	if (r1->rm_startblock + r1->rm_blockcount != r2->rm_startblock)
+		return false;
+	if ((unsigned long long)r1->rm_blockcount + r2->rm_blockcount >
+	    XFS_RMAP_LEN_MAX)
+		return false;
+	if (XFS_RMAP_NON_INODE_OWNER(r2->rm_owner))
+		return true;
+	/* must be an inode owner below here */
+	if (r1->rm_flags != r2->rm_flags)
+		return false;
+	if (r1->rm_flags & XFS_RMAP_BMBT_BLOCK)
+		return true;
+	return r1->rm_offset + r1->rm_blockcount == r2->rm_offset;
+}
+
+/* Flag failures for records that could be merged. */
+STATIC void
+xchk_rmapbt_check_mergeable(
+	struct xchk_btree		*bs,
+	struct xchk_rmap		*cr,
+	const struct xfs_rmap_irec	*irec)
+{
+	if (bs->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+		return;
+
+	if (xchk_rmap_mergeable(cr, irec))
+		xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
+
+	memcpy(&cr->prev_rec, irec, sizeof(struct xfs_rmap_irec));
+}
+
+/* Compare an rmap for AG metadata against the metadata walk. */
+STATIC int
+xchk_rmapbt_mark_bitmap(
+	struct xchk_btree		*bs,
+	struct xchk_rmap		*cr,
+	const struct xfs_rmap_irec	*irec)
+{
+	struct xfs_scrub		*sc = bs->sc;
+	struct xagb_bitmap		*bmp = NULL;
+	xfs_extlen_t			fsbcount = irec->rm_blockcount;
+
+	/*
+	 * Skip corrupt records.  It is essential that we detect records in the
+	 * btree that cannot overlap but do, flag those as CORRUPT, and skip
+	 * the bitmap comparison to avoid generating false XCORRUPT reports.
+	 */
+	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
+		return 0;
+
+	/*
+	 * If the AG metadata walk didn't complete, there's no point in
+	 * comparing against partial results.
+	 */
+	if (!cr->bitmaps_complete)
+		return 0;
+
+	switch (irec->rm_owner) {
+	case XFS_RMAP_OWN_FS:
+		bmp = &cr->fs_owned;
+		break;
+	case XFS_RMAP_OWN_LOG:
+		bmp = &cr->log_owned;
+		break;
+	case XFS_RMAP_OWN_AG:
+		bmp = &cr->ag_owned;
+		break;
+	case XFS_RMAP_OWN_INOBT:
+		bmp = &cr->inobt_owned;
+		break;
+	case XFS_RMAP_OWN_REFC:
+		bmp = &cr->refcbt_owned;
+		break;
+	}
+
+	if (!bmp)
+		return 0;
+
+	if (xagb_bitmap_test(bmp, irec->rm_startblock, &fsbcount)) {
+		/*
+		 * The start of this reverse mapping corresponds to a set
+		 * region in the bitmap.  If the mapping covers more area than
+		 * the set region, then it covers space that wasn't found by
+		 * the AG metadata walk.
+		 */
+		if (fsbcount < irec->rm_blockcount)
+			xchk_btree_xref_set_corrupt(bs->sc,
+					bs->sc->sa.rmap_cur, 0);
+	} else {
+		/*
+		 * The start of this reverse mapping does not correspond to a
+		 * completely set region in the bitmap.  The region wasn't
+		 * fully set by walking the AG metadata, so this is a
+		 * cross-referencing corruption.
+		 */
+		xchk_btree_xref_set_corrupt(bs->sc, bs->sc->sa.rmap_cur, 0);
+	}
+
+	/* Unset the region so that we can detect missing rmap records. */
+	return xagb_bitmap_clear(bmp, irec->rm_startblock, irec->rm_blockcount);
+}
+
+/* Scrub an rmapbt record. */
+STATIC int
+xchk_rmapbt_rec(
+	struct xchk_btree	*bs,
+	const union xfs_btree_rec *rec)
+{
+	struct xchk_rmap	*cr = bs->private;
+	struct xfs_rmap_irec	irec;
+
+	if (xfs_rmap_btrec_to_irec(rec, &irec) != NULL ||
+	    xfs_rmap_check_irec(bs->cur, &irec) != NULL) {
+		xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
+		return 0;
+	}
+
+	xchk_rmapbt_check_unwritten_in_keyflags(bs);
+	xchk_rmapbt_check_mergeable(bs, cr, &irec);
+	xchk_rmapbt_check_overlapping(bs, cr, &irec);
+	xchk_rmapbt_xref(bs->sc, &irec);
+
+	return xchk_rmapbt_mark_bitmap(bs, cr, &irec);
+}
+
+/* Add an AGFL block to the rmap list. */
+STATIC int
+xchk_rmapbt_walk_agfl(
+	struct xfs_mount	*mp,
+	xfs_agblock_t		agbno,
+	void			*priv)
+{
+	struct xagb_bitmap	*bitmap = priv;
+
+	return xagb_bitmap_set(bitmap, agbno, 1);
+}
+
+/*
+ * Set up bitmaps mapping all the AG metadata to compare with the rmapbt
+ * records.
+ *
+ * Grab our own btree cursors here if the scrub setup function didn't give us a
+ * btree cursor due to reports of poor health.  We need to find out if the
+ * rmapbt disagrees with primary metadata btrees to tag the rmapbt as being
+ * XCORRUPT.
+ */
+STATIC int
+xchk_rmapbt_walk_ag_metadata(
+	struct xfs_scrub	*sc,
+	struct xchk_rmap	*cr)
+{
+	struct xfs_mount	*mp = sc->mp;
+	struct xfs_buf		*agfl_bp;
+	struct xfs_agf		*agf = sc->sa.agf_bp->b_addr;
+	struct xfs_btree_cur	*cur;
+	int			error;
+
+	/* OWN_FS: AG headers */
+	error = xagb_bitmap_set(&cr->fs_owned, XFS_SB_BLOCK(mp),
+			XFS_AGFL_BLOCK(mp) - XFS_SB_BLOCK(mp) + 1);
+	if (error)
+		goto out;
+
+	/* OWN_LOG: Internal log */
+	if (xfs_ag_contains_log(mp, sc->sa.pag->pag_agno)) {
+		error = xagb_bitmap_set(&cr->log_owned,
+				XFS_FSB_TO_AGBNO(mp, mp->m_sb.sb_logstart),
+				mp->m_sb.sb_logblocks);
+		if (error)
+			goto out;
+	}
+
+	/* OWN_AG: bnobt, cntbt, rmapbt, and AGFL */
+	cur = sc->sa.bno_cur;
+	if (!cur)
+		cur = xfs_allocbt_init_cursor(sc->mp, sc->tp, sc->sa.agf_bp,
+				sc->sa.pag, XFS_BTNUM_BNO);
+	error = xagb_bitmap_set_btblocks(&cr->ag_owned, cur);
+	if (cur != sc->sa.bno_cur)
+		xfs_btree_del_cursor(cur, error);
+	if (error)
+		goto out;
+
+	cur = sc->sa.cnt_cur;
+	if (!cur)
+		cur = xfs_allocbt_init_cursor(sc->mp, sc->tp, sc->sa.agf_bp,
+				sc->sa.pag, XFS_BTNUM_CNT);
+	error = xagb_bitmap_set_btblocks(&cr->ag_owned, cur);
+	if (cur != sc->sa.cnt_cur)
+		xfs_btree_del_cursor(cur, error);
+	if (error)
+		goto out;
+
+	error = xagb_bitmap_set_btblocks(&cr->ag_owned, sc->sa.rmap_cur);
+	if (error)
+		goto out;
+
+	error = xfs_alloc_read_agfl(sc->sa.pag, sc->tp, &agfl_bp);
+	if (error)
+		goto out;
+
+	error = xfs_agfl_walk(sc->mp, agf, agfl_bp, xchk_rmapbt_walk_agfl,
+			&cr->ag_owned);
+	xfs_trans_brelse(sc->tp, agfl_bp);
+	if (error)
+		goto out;
+
+	/* OWN_INOBT: inobt, finobt */
+	cur = sc->sa.ino_cur;
+	if (!cur)
+		cur = xfs_inobt_init_cursor(sc->sa.pag, sc->tp, sc->sa.agi_bp,
+				XFS_BTNUM_INO);
+	error = xagb_bitmap_set_btblocks(&cr->inobt_owned, cur);
+	if (cur != sc->sa.ino_cur)
+		xfs_btree_del_cursor(cur, error);
+	if (error)
+		goto out;
+
+	if (xfs_has_finobt(sc->mp)) {
+		cur = sc->sa.fino_cur;
+		if (!cur)
+			cur = xfs_inobt_init_cursor(sc->sa.pag, sc->tp,
+					sc->sa.agi_bp, XFS_BTNUM_FINO);
+		error = xagb_bitmap_set_btblocks(&cr->inobt_owned, cur);
+		if (cur != sc->sa.fino_cur)
+			xfs_btree_del_cursor(cur, error);
+		if (error)
+			goto out;
+	}
+
+	/* OWN_REFC: refcountbt */
+	if (xfs_has_reflink(sc->mp)) {
+		cur = sc->sa.refc_cur;
+		if (!cur)
+			cur = xfs_refcountbt_init_cursor(sc->mp, sc->tp,
+					sc->sa.agf_bp, sc->sa.pag);
+		error = xagb_bitmap_set_btblocks(&cr->refcbt_owned, cur);
+		if (cur != sc->sa.refc_cur)
+			xfs_btree_del_cursor(cur, error);
+		if (error)
+			goto out;
+	}
+
+out:
+	/*
+	 * 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;
+	return 0;
+}
+
+/*
+ * Check for set regions in the bitmaps; if there are any, the rmap records do
+ * not describe all the AG metadata.
+ */
+STATIC void
+xchk_rmapbt_check_bitmaps(
+	struct xfs_scrub	*sc,
+	struct xchk_rmap	*cr)
+{
+	struct xfs_btree_cur	*cur = sc->sa.rmap_cur;
+	unsigned int		level;
+
+	if (sc->sm->sm_flags & (XFS_SCRUB_OFLAG_CORRUPT |
+				XFS_SCRUB_OFLAG_XFAIL))
+		return;
+	if (!cur)
+		return;
+	level = cur->bc_nlevels - 1;
+
+	/*
+	 * Any bitmap with bits still set indicates that the reverse mapping
+	 * doesn't cover the entire primary structure.
+	 */
+	if (xagb_bitmap_hweight(&cr->fs_owned) != 0)
+		xchk_btree_xref_set_corrupt(sc, cur, level);
+
+	if (xagb_bitmap_hweight(&cr->log_owned) != 0)
+		xchk_btree_xref_set_corrupt(sc, cur, level);
+
+	if (xagb_bitmap_hweight(&cr->ag_owned) != 0)
+		xchk_btree_xref_set_corrupt(sc, cur, level);
+
+	if (xagb_bitmap_hweight(&cr->inobt_owned) != 0)
+		xchk_btree_xref_set_corrupt(sc, cur, level);
+
+	if (xagb_bitmap_hweight(&cr->refcbt_owned) != 0)
+		xchk_btree_xref_set_corrupt(sc, cur, level);
+}
+
+/* Scrub the rmap btree for some AG. */
+int
+xchk_rmapbt(
+	struct xfs_scrub	*sc)
+{
+	struct xchk_rmap	*cr;
+	int			error;
+
+	cr = kzalloc(sizeof(struct xchk_rmap), XCHK_GFP_FLAGS);
+	if (!cr)
+		return -ENOMEM;
+
+	xagb_bitmap_init(&cr->fs_owned);
+	xagb_bitmap_init(&cr->log_owned);
+	xagb_bitmap_init(&cr->ag_owned);
+	xagb_bitmap_init(&cr->inobt_owned);
+	xagb_bitmap_init(&cr->refcbt_owned);
+
+	error = xchk_rmapbt_walk_ag_metadata(sc, cr);
+	if (error)
+		goto out;
+
+	error = xchk_btree(sc, sc->sa.rmap_cur, xchk_rmapbt_rec,
+			&XFS_RMAP_OINFO_AG, cr);
+	if (error)
+		goto out;
+
+	xchk_rmapbt_check_bitmaps(sc, cr);
+
+out:
+	xagb_bitmap_destroy(&cr->refcbt_owned);
+	xagb_bitmap_destroy(&cr->inobt_owned);
+	xagb_bitmap_destroy(&cr->ag_owned);
+	xagb_bitmap_destroy(&cr->log_owned);
+	xagb_bitmap_destroy(&cr->fs_owned);
+	kfree(cr);
+	return error;
+}
+
+/* xref check that the extent is owned only by a given owner */
+void
+xchk_xref_is_only_owned_by(
+	struct xfs_scrub		*sc,
+	xfs_agblock_t			bno,
+	xfs_extlen_t			len,
+	const struct xfs_owner_info	*oinfo)
+{
+	struct xfs_rmap_matches		res;
+	int				error;
+
+	if (!sc->sa.rmap_cur || xchk_skip_xref(sc->sm))
+		return;
+
+	error = xfs_rmap_count_owners(sc->sa.rmap_cur, bno, len, oinfo, &res);
+	if (!xchk_should_check_xref(sc, &error, &sc->sa.rmap_cur))
+		return;
+	if (res.matches != 1)
+		xchk_btree_xref_set_corrupt(sc, sc->sa.rmap_cur, 0);
+	if (res.bad_non_owner_matches)
+		xchk_btree_xref_set_corrupt(sc, sc->sa.rmap_cur, 0);
+	if (res.non_owner_matches)
+		xchk_btree_xref_set_corrupt(sc, sc->sa.rmap_cur, 0);
+}
+
+/* xref check that the extent is not owned by a given owner */
+void
+xchk_xref_is_not_owned_by(
+	struct xfs_scrub		*sc,
+	xfs_agblock_t			bno,
+	xfs_extlen_t			len,
+	const struct xfs_owner_info	*oinfo)
+{
+	struct xfs_rmap_matches		res;
+	int				error;
+
+	if (!sc->sa.rmap_cur || xchk_skip_xref(sc->sm))
+		return;
+
+	error = xfs_rmap_count_owners(sc->sa.rmap_cur, bno, len, oinfo, &res);
+	if (!xchk_should_check_xref(sc, &error, &sc->sa.rmap_cur))
+		return;
+	if (res.matches != 0)
+		xchk_btree_xref_set_corrupt(sc, sc->sa.rmap_cur, 0);
+	if (res.bad_non_owner_matches)
+		xchk_btree_xref_set_corrupt(sc, sc->sa.rmap_cur, 0);
+}
+
+/* xref check that the extent has no reverse mapping at all */
+void
+xchk_xref_has_no_owner(
+	struct xfs_scrub	*sc,
+	xfs_agblock_t		bno,
+	xfs_extlen_t		len)
+{
+	enum xbtree_recpacking	outcome;
+	int			error;
+
+	if (!sc->sa.rmap_cur || xchk_skip_xref(sc->sm))
+		return;
+
+	error = xfs_rmap_has_records(sc->sa.rmap_cur, bno, len, &outcome);
+	if (!xchk_should_check_xref(sc, &error, &sc->sa.rmap_cur))
+		return;
+	if (outcome != XBTREE_RECPACKING_EMPTY)
+		xchk_btree_xref_set_corrupt(sc, sc->sa.rmap_cur, 0);
+}