rtrefcount.c

  1// SPDX-License-Identifier: GPL-2.0-or-later
  2/*
  3 * Copyright (c) 2021-2024 Oracle.  All Rights Reserved.
  4 * Author: Darrick J. Wong <djwong@kernel.org>
  5 */
  6#include "xfs.h"
  7#include "xfs_fs.h"
  8#include "xfs_shared.h"
  9#include "xfs_format.h"
 10#include "xfs_log_format.h"
 11#include "xfs_trans_resv.h"
 12#include "xfs_mount.h"
 13#include "xfs_trans.h"
 14#include "xfs_btree.h"
 15#include "xfs_rmap.h"
 16#include "xfs_refcount.h"
 17#include "xfs_inode.h"
 18#include "xfs_rtbitmap.h"
 19#include "xfs_rtgroup.h"
 20#include "xfs_metafile.h"
 21#include "xfs_rtrefcount_btree.h"
 22#include "xfs_rtalloc.h"
 23#include "scrub/scrub.h"
 24#include "scrub/common.h"
 25#include "scrub/btree.h"
 26#include "scrub/repair.h"
 27
 28/* Set us up with the realtime refcount metadata locked. */
 29int
 30xchk_setup_rtrefcountbt(
 31	struct xfs_scrub	*sc)
 32{
 33	int			error;
 34
 35	if (xchk_need_intent_drain(sc))
 36		xchk_fsgates_enable(sc, XCHK_FSGATES_DRAIN);
 37
 38	if (xchk_could_repair(sc)) {
 39		error = xrep_setup_rtrefcountbt(sc);
 40		if (error)
 41			return error;
 42	}
 43
 44	error = xchk_rtgroup_init(sc, sc->sm->sm_agno, &sc->sr);
 45	if (error)
 46		return error;
 47
 48	error = xchk_setup_rt(sc);
 49	if (error)
 50		return error;
 51
 52	error = xchk_install_live_inode(sc, rtg_refcount(sc->sr.rtg));
 53	if (error)
 54		return error;
 55
 56	return xchk_rtgroup_lock(sc, &sc->sr, XCHK_RTGLOCK_ALL);
 57}
 58
 59/* Realtime Reference count btree scrubber. */
 60
 61/*
 62 * Confirming Reference Counts via Reverse Mappings
 63 *
 64 * We want to count the reverse mappings overlapping a refcount record
 65 * (bno, len, refcount), allowing for the possibility that some of the
 66 * overlap may come from smaller adjoining reverse mappings, while some
 67 * comes from single extents which overlap the range entirely.  The
 68 * outer loop is as follows:
 69 *
 70 * 1. For all reverse mappings overlapping the refcount extent,
 71 *    a. If a given rmap completely overlaps, mark it as seen.
 72 *    b. Otherwise, record the fragment (in agbno order) for later
 73 *       processing.
 74 *
 75 * Once we've seen all the rmaps, we know that for all blocks in the
 76 * refcount record we want to find $refcount owners and we've already
 77 * visited $seen extents that overlap all the blocks.  Therefore, we
 78 * need to find ($refcount - $seen) owners for every block in the
 79 * extent; call that quantity $target_nr.  Proceed as follows:
 80 *
 81 * 2. Pull the first $target_nr fragments from the list; all of them
 82 *    should start at or before the start of the extent.
 83 *    Call this subset of fragments the working set.
 84 * 3. Until there are no more unprocessed fragments,
 85 *    a. Find the shortest fragments in the set and remove them.
 86 *    b. Note the block number of the end of these fragments.
 87 *    c. Pull the same number of fragments from the list.  All of these
 88 *       fragments should start at the block number recorded in the
 89 *       previous step.
 90 *    d. Put those fragments in the set.
 91 * 4. Check that there are $target_nr fragments remaining in the list,
 92 *    and that they all end at or beyond the end of the refcount extent.
 93 *
 94 * If the refcount is correct, all the check conditions in the algorithm
 95 * should always hold true.  If not, the refcount is incorrect.
 96 */
 97struct xchk_rtrefcnt_frag {
 98	struct list_head	list;
 99	struct xfs_rmap_irec	rm;
100};
101
102struct xchk_rtrefcnt_check {
103	struct xfs_scrub	*sc;
104	struct list_head	fragments;
105
106	/* refcount extent we're examining */
107	xfs_rgblock_t		bno;
108	xfs_extlen_t		len;
109	xfs_nlink_t		refcount;
110
111	/* number of owners seen */
112	xfs_nlink_t		seen;
113};
114
115/*
116 * Decide if the given rmap is large enough that we can redeem it
117 * towards refcount verification now, or if it's a fragment, in
118 * which case we'll hang onto it in the hopes that we'll later
119 * discover that we've collected exactly the correct number of
120 * fragments as the rtrefcountbt says we should have.
121 */
122STATIC int
123xchk_rtrefcountbt_rmap_check(
124	struct xfs_btree_cur		*cur,
125	const struct xfs_rmap_irec	*rec,
126	void				*priv)
127{
128	struct xchk_rtrefcnt_check	*refchk = priv;
129	struct xchk_rtrefcnt_frag	*frag;
130	xfs_rgblock_t			rm_last;
131	xfs_rgblock_t			rc_last;
132	int				error = 0;
133
134	if (xchk_should_terminate(refchk->sc, &error))
135		return error;
136
137	rm_last = rec->rm_startblock + rec->rm_blockcount - 1;
138	rc_last = refchk->bno + refchk->len - 1;
139
140	/* Confirm that a single-owner refc extent is a CoW stage. */
141	if (refchk->refcount == 1 && rec->rm_owner != XFS_RMAP_OWN_COW) {
142		xchk_btree_xref_set_corrupt(refchk->sc, cur, 0);
143		return 0;
144	}
145
146	if (rec->rm_startblock <= refchk->bno && rm_last >= rc_last) {
147		/*
148		 * The rmap overlaps the refcount record, so we can confirm
149		 * one refcount owner seen.
150		 */
151		refchk->seen++;
152	} else {
153		/*
154		 * This rmap covers only part of the refcount record, so
155		 * save the fragment for later processing.  If the rmapbt
156		 * is healthy each rmap_irec we see will be in agbno order
157		 * so we don't need insertion sort here.
158		 */
159		frag = kmalloc(sizeof(struct xchk_rtrefcnt_frag),
160				XCHK_GFP_FLAGS);
161		if (!frag)
162			return -ENOMEM;
163		memcpy(&frag->rm, rec, sizeof(frag->rm));
164		list_add_tail(&frag->list, &refchk->fragments);
165	}
166
167	return 0;
168}
169
170/*
171 * Given a bunch of rmap fragments, iterate through them, keeping
172 * a running tally of the refcount.  If this ever deviates from
173 * what we expect (which is the rtrefcountbt's refcount minus the
174 * number of extents that totally covered the rtrefcountbt extent),
175 * we have a rtrefcountbt error.
176 */
177STATIC void
178xchk_rtrefcountbt_process_rmap_fragments(
179	struct xchk_rtrefcnt_check	*refchk)
180{
181	struct list_head		worklist;
182	struct xchk_rtrefcnt_frag	*frag;
183	struct xchk_rtrefcnt_frag	*n;
184	xfs_rgblock_t			bno;
185	xfs_rgblock_t			rbno;
186	xfs_rgblock_t			next_rbno;
187	xfs_nlink_t			nr;
188	xfs_nlink_t			target_nr;
189
190	target_nr = refchk->refcount - refchk->seen;
191	if (target_nr == 0)
192		return;
193
194	/*
195	 * There are (refchk->rc.rc_refcount - refchk->nr refcount)
196	 * references we haven't found yet.  Pull that many off the
197	 * fragment list and figure out where the smallest rmap ends
198	 * (and therefore the next rmap should start).  All the rmaps
199	 * we pull off should start at or before the beginning of the
200	 * refcount record's range.
201	 */
202	INIT_LIST_HEAD(&worklist);
203	rbno = NULLRGBLOCK;
204
205	/* Make sure the fragments actually /are/ in bno order. */
206	bno = 0;
207	list_for_each_entry(frag, &refchk->fragments, list) {
208		if (frag->rm.rm_startblock < bno)
209			goto done;
210		bno = frag->rm.rm_startblock;
211	}
212
213	/*
214	 * Find all the rmaps that start at or before the refc extent,
215	 * and put them on the worklist.
216	 */
217	nr = 0;
218	list_for_each_entry_safe(frag, n, &refchk->fragments, list) {
219		if (frag->rm.rm_startblock > refchk->bno || nr > target_nr)
220			break;
221		bno = frag->rm.rm_startblock + frag->rm.rm_blockcount;
222		if (bno < rbno)
223			rbno = bno;
224		list_move_tail(&frag->list, &worklist);
225		nr++;
226	}
227
228	/*
229	 * We should have found exactly $target_nr rmap fragments starting
230	 * at or before the refcount extent.
231	 */
232	if (nr != target_nr)
233		goto done;
234
235	while (!list_empty(&refchk->fragments)) {
236		/* Discard any fragments ending at rbno from the worklist. */
237		nr = 0;
238		next_rbno = NULLRGBLOCK;
239		list_for_each_entry_safe(frag, n, &worklist, list) {
240			bno = frag->rm.rm_startblock + frag->rm.rm_blockcount;
241			if (bno != rbno) {
242				if (bno < next_rbno)
243					next_rbno = bno;
244				continue;
245			}
246			list_del(&frag->list);
247			kfree(frag);
248			nr++;
249		}
250
251		/* Try to add nr rmaps starting at rbno to the worklist. */
252		list_for_each_entry_safe(frag, n, &refchk->fragments, list) {
253			bno = frag->rm.rm_startblock + frag->rm.rm_blockcount;
254			if (frag->rm.rm_startblock != rbno)
255				goto done;
256			list_move_tail(&frag->list, &worklist);
257			if (next_rbno > bno)
258				next_rbno = bno;
259			nr--;
260			if (nr == 0)
261				break;
262		}
263
264		/*
265		 * If we get here and nr > 0, this means that we added fewer
266		 * items to the worklist than we discarded because the fragment
267		 * list ran out of items.  Therefore, we cannot maintain the
268		 * required refcount.  Something is wrong, so we're done.
269		 */
270		if (nr)
271			goto done;
272
273		rbno = next_rbno;
274	}
275
276	/*
277	 * Make sure the last extent we processed ends at or beyond
278	 * the end of the refcount extent.
279	 */
280	if (rbno < refchk->bno + refchk->len)
281		goto done;
282
283	/* Actually record us having seen the remaining refcount. */
284	refchk->seen = refchk->refcount;
285done:
286	/* Delete fragments and work list. */
287	list_for_each_entry_safe(frag, n, &worklist, list) {
288		list_del(&frag->list);
289		kfree(frag);
290	}
291	list_for_each_entry_safe(frag, n, &refchk->fragments, list) {
292		list_del(&frag->list);
293		kfree(frag);
294	}
295}
296
297/* Use the rmap entries covering this extent to verify the refcount. */
298STATIC void
299xchk_rtrefcountbt_xref_rmap(
300	struct xfs_scrub		*sc,
301	const struct xfs_refcount_irec	*irec)
302{
303	struct xchk_rtrefcnt_check	refchk = {
304		.sc			= sc,
305		.bno			= irec->rc_startblock,
306		.len			= irec->rc_blockcount,
307		.refcount		= irec->rc_refcount,
308		.seen			= 0,
309	};
310	struct xfs_rmap_irec		low;
311	struct xfs_rmap_irec		high;
312	struct xchk_rtrefcnt_frag	*frag;
313	struct xchk_rtrefcnt_frag	*n;
314	int				error;
315
316	if (!sc->sr.rmap_cur || xchk_skip_xref(sc->sm))
317		return;
318
319	/* Cross-reference with the rmapbt to confirm the refcount. */
320	memset(&low, 0, sizeof(low));
321	low.rm_startblock = irec->rc_startblock;
322	memset(&high, 0xFF, sizeof(high));
323	high.rm_startblock = irec->rc_startblock + irec->rc_blockcount - 1;
324
325	INIT_LIST_HEAD(&refchk.fragments);
326	error = xfs_rmap_query_range(sc->sr.rmap_cur, &low, &high,
327			xchk_rtrefcountbt_rmap_check, &refchk);
328	if (!xchk_should_check_xref(sc, &error, &sc->sr.rmap_cur))
329		goto out_free;
330
331	xchk_rtrefcountbt_process_rmap_fragments(&refchk);
332	if (irec->rc_refcount != refchk.seen)
333		xchk_btree_xref_set_corrupt(sc, sc->sr.rmap_cur, 0);
334
335out_free:
336	list_for_each_entry_safe(frag, n, &refchk.fragments, list) {
337		list_del(&frag->list);
338		kfree(frag);
339	}
340}
341
342/* Cross-reference with the other btrees. */
343STATIC void
344xchk_rtrefcountbt_xref(
345	struct xfs_scrub		*sc,
346	const struct xfs_refcount_irec	*irec)
347{
348	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
349		return;
350
351	xchk_xref_is_used_rt_space(sc,
352			xfs_rgbno_to_rtb(sc->sr.rtg, irec->rc_startblock),
353			irec->rc_blockcount);
354	xchk_rtrefcountbt_xref_rmap(sc, irec);
355}
356
357struct xchk_rtrefcbt_records {
358	/* Previous refcount record. */
359	struct xfs_refcount_irec	prev_rec;
360
361	/* The next rtgroup block where we aren't expecting shared extents. */
362	xfs_rgblock_t			next_unshared_rgbno;
363
364	/* Number of CoW blocks we expect. */
365	xfs_extlen_t			cow_blocks;
366
367	/* Was the last record a shared or CoW staging extent? */
368	enum xfs_refc_domain		prev_domain;
369};
370
371static inline bool
372xchk_rtrefcount_mergeable(
373	struct xchk_rtrefcbt_records	*rrc,
374	const struct xfs_refcount_irec	*r2)
375{
376	const struct xfs_refcount_irec	*r1 = &rrc->prev_rec;
377
378	/* Ignore if prev_rec is not yet initialized. */
379	if (r1->rc_blockcount > 0)
380		return false;
381
382	if (r1->rc_startblock + r1->rc_blockcount != r2->rc_startblock)
383		return false;
384	if (r1->rc_refcount != r2->rc_refcount)
385		return false;
386	if ((unsigned long long)r1->rc_blockcount + r2->rc_blockcount >
387			XFS_REFC_LEN_MAX)
388		return false;
389
390	return true;
391}
392
393/* Flag failures for records that could be merged. */
394STATIC void
395xchk_rtrefcountbt_check_mergeable(
396	struct xchk_btree		*bs,
397	struct xchk_rtrefcbt_records	*rrc,
398	const struct xfs_refcount_irec	*irec)
399{
400	if (bs->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
401		return;
402
403	if (xchk_rtrefcount_mergeable(rrc, irec))
404		xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
405
406	memcpy(&rrc->prev_rec, irec, sizeof(struct xfs_refcount_irec));
407}
408
409STATIC int
410xchk_rtrefcountbt_rmap_check_gap(
411	struct xfs_btree_cur		*cur,
412	const struct xfs_rmap_irec	*rec,
413	void				*priv)
414{
415	xfs_rgblock_t			*next_bno = priv;
416
417	if (*next_bno != NULLRGBLOCK && rec->rm_startblock < *next_bno)
418		return -ECANCELED;
419
420	*next_bno = rec->rm_startblock + rec->rm_blockcount;
421	return 0;
422}
423
424/*
425 * Make sure that a gap in the reference count records does not correspond to
426 * overlapping records (i.e. shared extents) in the reverse mappings.
427 */
428static inline void
429xchk_rtrefcountbt_xref_gaps(
430	struct xfs_scrub	*sc,
431	struct xchk_rtrefcbt_records *rrc,
432	xfs_rtblock_t		bno)
433{
434	struct xfs_rmap_irec	low;
435	struct xfs_rmap_irec	high;
436	xfs_rgblock_t		next_bno = NULLRGBLOCK;
437	int			error;
438
439	if (bno <= rrc->next_unshared_rgbno || !sc->sr.rmap_cur ||
440            xchk_skip_xref(sc->sm))
441		return;
442
443	memset(&low, 0, sizeof(low));
444	low.rm_startblock = rrc->next_unshared_rgbno;
445	memset(&high, 0xFF, sizeof(high));
446	high.rm_startblock = bno - 1;
447
448	error = xfs_rmap_query_range(sc->sr.rmap_cur, &low, &high,
449			xchk_rtrefcountbt_rmap_check_gap, &next_bno);
450	if (error == -ECANCELED)
451		xchk_btree_xref_set_corrupt(sc, sc->sr.rmap_cur, 0);
452	else
453		xchk_should_check_xref(sc, &error, &sc->sr.rmap_cur);
454}
455
456/* Scrub a rtrefcountbt record. */
457STATIC int
458xchk_rtrefcountbt_rec(
459	struct xchk_btree		*bs,
460	const union xfs_btree_rec	*rec)
461{
462	struct xfs_mount		*mp = bs->cur->bc_mp;
463	struct xchk_rtrefcbt_records	*rrc = bs->private;
464	struct xfs_refcount_irec	irec;
465	u32				mod;
466
467	xfs_refcount_btrec_to_irec(rec, &irec);
468	if (xfs_rtrefcount_check_irec(to_rtg(bs->cur->bc_group), &irec) !=
469			NULL) {
470		xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
471		return 0;
472	}
473
474	/* We can only share full rt extents. */
475	mod = xfs_rgbno_to_rtxoff(mp, irec.rc_startblock);
476	if (mod)
477		xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
478	mod = xfs_extlen_to_rtxmod(mp, irec.rc_blockcount);
479	if (mod)
480		xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
481
482	if (irec.rc_domain == XFS_REFC_DOMAIN_COW)
483		rrc->cow_blocks += irec.rc_blockcount;
484
485	/* Shared records always come before CoW records. */
486	if (irec.rc_domain == XFS_REFC_DOMAIN_SHARED &&
487	    rrc->prev_domain == XFS_REFC_DOMAIN_COW)
488		xchk_btree_set_corrupt(bs->sc, bs->cur, 0);
489	rrc->prev_domain = irec.rc_domain;
490
491	xchk_rtrefcountbt_check_mergeable(bs, rrc, &irec);
492	xchk_rtrefcountbt_xref(bs->sc, &irec);
493
494	/*
495	 * If this is a record for a shared extent, check that all blocks
496	 * between the previous record and this one have at most one reverse
497	 * mapping.
498	 */
499	if (irec.rc_domain == XFS_REFC_DOMAIN_SHARED) {
500		xchk_rtrefcountbt_xref_gaps(bs->sc, rrc, irec.rc_startblock);
501		rrc->next_unshared_rgbno = irec.rc_startblock +
502					   irec.rc_blockcount;
503	}
504
505	return 0;
506}
507
508/* Make sure we have as many refc blocks as the rmap says. */
509STATIC void
510xchk_refcount_xref_rmap(
511	struct xfs_scrub	*sc,
512	const struct xfs_owner_info *btree_oinfo,
513	xfs_extlen_t		cow_blocks)
514{
515	xfs_filblks_t		refcbt_blocks = 0;
516	xfs_filblks_t		blocks;
517	int			error;
518
519	if (!sc->sr.rmap_cur || !sc->sa.rmap_cur || xchk_skip_xref(sc->sm))
520		return;
521
522	/* Check that we saw as many refcbt blocks as the rmap knows about. */
523	error = xfs_btree_count_blocks(sc->sr.refc_cur, &refcbt_blocks);
524	if (!xchk_btree_process_error(sc, sc->sr.refc_cur, 0, &error))
525		return;
526	error = xchk_count_rmap_ownedby_ag(sc, sc->sa.rmap_cur, btree_oinfo,
527			&blocks);
528	if (!xchk_should_check_xref(sc, &error, &sc->sa.rmap_cur))
529		return;
530	if (blocks != refcbt_blocks)
531		xchk_btree_xref_set_corrupt(sc, sc->sa.rmap_cur, 0);
532
533	/* Check that we saw as many cow blocks as the rmap knows about. */
534	error = xchk_count_rmap_ownedby_ag(sc, sc->sr.rmap_cur,
535			&XFS_RMAP_OINFO_COW, &blocks);
536	if (!xchk_should_check_xref(sc, &error, &sc->sr.rmap_cur))
537		return;
538	if (blocks != cow_blocks)
539		xchk_btree_xref_set_corrupt(sc, sc->sr.rmap_cur, 0);
540}
541
542/* Scrub the refcount btree for some AG. */
543int
544xchk_rtrefcountbt(
545	struct xfs_scrub	*sc)
546{
547	struct xfs_owner_info	btree_oinfo;
548	struct xchk_rtrefcbt_records rrc = {
549		.cow_blocks		= 0,
550		.next_unshared_rgbno	= 0,
551		.prev_domain		= XFS_REFC_DOMAIN_SHARED,
552	};
553	int			error;
554
555	error = xchk_metadata_inode_forks(sc);
556	if (error || (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
557		return error;
558
559	xfs_rmap_ino_bmbt_owner(&btree_oinfo, rtg_refcount(sc->sr.rtg)->i_ino,
560			XFS_DATA_FORK);
561	error = xchk_btree(sc, sc->sr.refc_cur, xchk_rtrefcountbt_rec,
562			&btree_oinfo, &rrc);
563	if (error || (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
564		return error;
565
566	/*
567	 * Check that all blocks between the last refcount > 1 record and the
568	 * end of the rt volume have at most one reverse mapping.
569	 */
570	xchk_rtrefcountbt_xref_gaps(sc, &rrc, sc->mp->m_sb.sb_rblocks);
571
572	xchk_refcount_xref_rmap(sc, &btree_oinfo, rrc.cow_blocks);
573
574	return 0;
575}
576
577/* xref check that a cow staging extent is marked in the rtrefcountbt. */
578void
579xchk_xref_is_rt_cow_staging(
580	struct xfs_scrub		*sc,
581	xfs_rgblock_t			bno,
582	xfs_extlen_t			len)
583{
584	struct xfs_refcount_irec	rc;
585	int				has_refcount;
586	int				error;
587
588	if (!sc->sr.refc_cur || xchk_skip_xref(sc->sm))
589		return;
590
591	/* Find the CoW staging extent. */
592	error = xfs_refcount_lookup_le(sc->sr.refc_cur, XFS_REFC_DOMAIN_COW,
593			bno, &has_refcount);
594	if (!xchk_should_check_xref(sc, &error, &sc->sr.refc_cur))
595		return;
596	if (!has_refcount) {
597		xchk_btree_xref_set_corrupt(sc, sc->sr.refc_cur, 0);
598		return;
599	}
600
601	error = xfs_refcount_get_rec(sc->sr.refc_cur, &rc, &has_refcount);
602	if (!xchk_should_check_xref(sc, &error, &sc->sr.refc_cur))
603		return;
604	if (!has_refcount) {
605		xchk_btree_xref_set_corrupt(sc, sc->sr.refc_cur, 0);
606		return;
607	}
608
609	/* CoW lookup returned a shared extent record? */
610	if (rc.rc_domain != XFS_REFC_DOMAIN_COW)
611		xchk_btree_xref_set_corrupt(sc, sc->sa.refc_cur, 0);
612
613	/* Must be at least as long as what was passed in */
614	if (rc.rc_blockcount < len)
615		xchk_btree_xref_set_corrupt(sc, sc->sr.refc_cur, 0);
616}
617
618/*
619 * xref check that the extent is not shared.  Only file data blocks
620 * can have multiple owners.
621 */
622void
623xchk_xref_is_not_rt_shared(
624	struct xfs_scrub	*sc,
625	xfs_rgblock_t		bno,
626	xfs_extlen_t		len)
627{
628	enum xbtree_recpacking	outcome;
629	int			error;
630
631	if (!sc->sr.refc_cur || xchk_skip_xref(sc->sm))
632		return;
633
634	error = xfs_refcount_has_records(sc->sr.refc_cur,
635			XFS_REFC_DOMAIN_SHARED, bno, len, &outcome);
636	if (!xchk_should_check_xref(sc, &error, &sc->sr.refc_cur))
637		return;
638	if (outcome != XBTREE_RECPACKING_EMPTY)
639		xchk_btree_xref_set_corrupt(sc, sc->sr.refc_cur, 0);
640}
641
642/* xref check that the extent is not being used for CoW staging. */
643void
644xchk_xref_is_not_rt_cow_staging(
645	struct xfs_scrub	*sc,
646	xfs_rgblock_t		bno,
647	xfs_extlen_t		len)
648{
649	enum xbtree_recpacking	outcome;
650	int			error;
651
652	if (!sc->sr.refc_cur || xchk_skip_xref(sc->sm))
653		return;
654
655	error = xfs_refcount_has_records(sc->sr.refc_cur, XFS_REFC_DOMAIN_COW,
656			bno, len, &outcome);
657	if (!xchk_should_check_xref(sc, &error, &sc->sr.refc_cur))
658		return;
659	if (outcome != XBTREE_RECPACKING_EMPTY)
660		xchk_btree_xref_set_corrupt(sc, sc->sr.refc_cur, 0);
661}