xref: /linux/fs/xfs/scrub/bmap.c (revision f2bf88c4afc8c5ab92b40af24819933e57d0968c)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2017 Oracle.  All Rights Reserved.
4  * Author: Darrick J. Wong <darrick.wong@oracle.com>
5  */
6 #include "xfs.h"
7 #include "xfs_fs.h"
8 #include "xfs_shared.h"
9 #include "xfs_format.h"
10 #include "xfs_trans_resv.h"
11 #include "xfs_mount.h"
12 #include "xfs_btree.h"
13 #include "xfs_bit.h"
14 #include "xfs_log_format.h"
15 #include "xfs_trans.h"
16 #include "xfs_inode.h"
17 #include "xfs_alloc.h"
18 #include "xfs_bmap.h"
19 #include "xfs_bmap_btree.h"
20 #include "xfs_rmap.h"
21 #include "xfs_rmap_btree.h"
22 #include "scrub/scrub.h"
23 #include "scrub/common.h"
24 #include "scrub/btree.h"
25 
26 /* Set us up with an inode's bmap. */
27 int
28 xchk_setup_inode_bmap(
29 	struct xfs_scrub	*sc,
30 	struct xfs_inode	*ip)
31 {
32 	int			error;
33 
34 	error = xchk_get_inode(sc, ip);
35 	if (error)
36 		goto out;
37 
38 	sc->ilock_flags = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
39 	xfs_ilock(sc->ip, sc->ilock_flags);
40 
41 	/*
42 	 * We don't want any ephemeral data fork updates sitting around
43 	 * while we inspect block mappings, so wait for directio to finish
44 	 * and flush dirty data if we have delalloc reservations.
45 	 */
46 	if (S_ISREG(VFS_I(sc->ip)->i_mode) &&
47 	    sc->sm->sm_type == XFS_SCRUB_TYPE_BMBTD) {
48 		struct address_space	*mapping = VFS_I(sc->ip)->i_mapping;
49 
50 		inode_dio_wait(VFS_I(sc->ip));
51 
52 		/*
53 		 * Try to flush all incore state to disk before we examine the
54 		 * space mappings for the data fork.  Leave accumulated errors
55 		 * in the mapping for the writer threads to consume.
56 		 *
57 		 * On ENOSPC or EIO writeback errors, we continue into the
58 		 * extent mapping checks because write failures do not
59 		 * necessarily imply anything about the correctness of the file
60 		 * metadata.  The metadata and the file data could be on
61 		 * completely separate devices; a media failure might only
62 		 * affect a subset of the disk, etc.  We can handle delalloc
63 		 * extents in the scrubber, so leaving them in memory is fine.
64 		 */
65 		error = filemap_fdatawrite(mapping);
66 		if (!error)
67 			error = filemap_fdatawait_keep_errors(mapping);
68 		if (error && (error != -ENOSPC && error != -EIO))
69 			goto out;
70 	}
71 
72 	/* Got the inode, lock it and we're ready to go. */
73 	error = xchk_trans_alloc(sc, 0);
74 	if (error)
75 		goto out;
76 	sc->ilock_flags |= XFS_ILOCK_EXCL;
77 	xfs_ilock(sc->ip, XFS_ILOCK_EXCL);
78 
79 out:
80 	/* scrub teardown will unlock and release the inode */
81 	return error;
82 }
83 
84 /*
85  * Inode fork block mapping (BMBT) scrubber.
86  * More complex than the others because we have to scrub
87  * all the extents regardless of whether or not the fork
88  * is in btree format.
89  */
90 
91 struct xchk_bmap_info {
92 	struct xfs_scrub	*sc;
93 	xfs_fileoff_t		lastoff;
94 	bool			is_rt;
95 	bool			is_shared;
96 	bool			was_loaded;
97 	int			whichfork;
98 };
99 
100 /* Look for a corresponding rmap for this irec. */
101 static inline bool
102 xchk_bmap_get_rmap(
103 	struct xchk_bmap_info	*info,
104 	struct xfs_bmbt_irec	*irec,
105 	xfs_agblock_t		agbno,
106 	uint64_t		owner,
107 	struct xfs_rmap_irec	*rmap)
108 {
109 	xfs_fileoff_t		offset;
110 	unsigned int		rflags = 0;
111 	int			has_rmap;
112 	int			error;
113 
114 	if (info->whichfork == XFS_ATTR_FORK)
115 		rflags |= XFS_RMAP_ATTR_FORK;
116 
117 	/*
118 	 * CoW staging extents are owned (on disk) by the refcountbt, so
119 	 * their rmaps do not have offsets.
120 	 */
121 	if (info->whichfork == XFS_COW_FORK)
122 		offset = 0;
123 	else
124 		offset = irec->br_startoff;
125 
126 	/*
127 	 * If the caller thinks this could be a shared bmbt extent (IOWs,
128 	 * any data fork extent of a reflink inode) then we have to use the
129 	 * range rmap lookup to make sure we get the correct owner/offset.
130 	 */
131 	if (info->is_shared) {
132 		error = xfs_rmap_lookup_le_range(info->sc->sa.rmap_cur, agbno,
133 				owner, offset, rflags, rmap, &has_rmap);
134 		if (!xchk_should_check_xref(info->sc, &error,
135 				&info->sc->sa.rmap_cur))
136 			return false;
137 		goto out;
138 	}
139 
140 	/*
141 	 * Otherwise, use the (faster) regular lookup.
142 	 */
143 	error = xfs_rmap_lookup_le(info->sc->sa.rmap_cur, agbno, 0, owner,
144 			offset, rflags, &has_rmap);
145 	if (!xchk_should_check_xref(info->sc, &error,
146 			&info->sc->sa.rmap_cur))
147 		return false;
148 	if (!has_rmap)
149 		goto out;
150 
151 	error = xfs_rmap_get_rec(info->sc->sa.rmap_cur, rmap, &has_rmap);
152 	if (!xchk_should_check_xref(info->sc, &error,
153 			&info->sc->sa.rmap_cur))
154 		return false;
155 
156 out:
157 	if (!has_rmap)
158 		xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
159 			irec->br_startoff);
160 	return has_rmap;
161 }
162 
163 /* Make sure that we have rmapbt records for this extent. */
164 STATIC void
165 xchk_bmap_xref_rmap(
166 	struct xchk_bmap_info	*info,
167 	struct xfs_bmbt_irec	*irec,
168 	xfs_agblock_t		agbno)
169 {
170 	struct xfs_rmap_irec	rmap;
171 	unsigned long long	rmap_end;
172 	uint64_t		owner;
173 
174 	if (!info->sc->sa.rmap_cur || xchk_skip_xref(info->sc->sm))
175 		return;
176 
177 	if (info->whichfork == XFS_COW_FORK)
178 		owner = XFS_RMAP_OWN_COW;
179 	else
180 		owner = info->sc->ip->i_ino;
181 
182 	/* Find the rmap record for this irec. */
183 	if (!xchk_bmap_get_rmap(info, irec, agbno, owner, &rmap))
184 		return;
185 
186 	/* Check the rmap. */
187 	rmap_end = (unsigned long long)rmap.rm_startblock + rmap.rm_blockcount;
188 	if (rmap.rm_startblock > agbno ||
189 	    agbno + irec->br_blockcount > rmap_end)
190 		xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
191 				irec->br_startoff);
192 
193 	/*
194 	 * Check the logical offsets if applicable.  CoW staging extents
195 	 * don't track logical offsets since the mappings only exist in
196 	 * memory.
197 	 */
198 	if (info->whichfork != XFS_COW_FORK) {
199 		rmap_end = (unsigned long long)rmap.rm_offset +
200 				rmap.rm_blockcount;
201 		if (rmap.rm_offset > irec->br_startoff ||
202 		    irec->br_startoff + irec->br_blockcount > rmap_end)
203 			xchk_fblock_xref_set_corrupt(info->sc,
204 					info->whichfork, irec->br_startoff);
205 	}
206 
207 	if (rmap.rm_owner != owner)
208 		xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
209 				irec->br_startoff);
210 
211 	/*
212 	 * Check for discrepancies between the unwritten flag in the irec and
213 	 * the rmap.  Note that the (in-memory) CoW fork distinguishes between
214 	 * unwritten and written extents, but we don't track that in the rmap
215 	 * records because the blocks are owned (on-disk) by the refcountbt,
216 	 * which doesn't track unwritten state.
217 	 */
218 	if (owner != XFS_RMAP_OWN_COW &&
219 	    irec->br_state == XFS_EXT_UNWRITTEN &&
220 	    !(rmap.rm_flags & XFS_RMAP_UNWRITTEN))
221 		xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
222 				irec->br_startoff);
223 
224 	if (info->whichfork == XFS_ATTR_FORK &&
225 	    !(rmap.rm_flags & XFS_RMAP_ATTR_FORK))
226 		xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
227 				irec->br_startoff);
228 	if (rmap.rm_flags & XFS_RMAP_BMBT_BLOCK)
229 		xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
230 				irec->br_startoff);
231 }
232 
233 /* Cross-reference a single rtdev extent record. */
234 STATIC void
235 xchk_bmap_rt_iextent_xref(
236 	struct xfs_inode	*ip,
237 	struct xchk_bmap_info	*info,
238 	struct xfs_bmbt_irec	*irec)
239 {
240 	xchk_xref_is_used_rt_space(info->sc, irec->br_startblock,
241 			irec->br_blockcount);
242 }
243 
244 /* Cross-reference a single datadev extent record. */
245 STATIC void
246 xchk_bmap_iextent_xref(
247 	struct xfs_inode	*ip,
248 	struct xchk_bmap_info	*info,
249 	struct xfs_bmbt_irec	*irec)
250 {
251 	struct xfs_mount	*mp = info->sc->mp;
252 	xfs_agnumber_t		agno;
253 	xfs_agblock_t		agbno;
254 	xfs_extlen_t		len;
255 	int			error;
256 
257 	agno = XFS_FSB_TO_AGNO(mp, irec->br_startblock);
258 	agbno = XFS_FSB_TO_AGBNO(mp, irec->br_startblock);
259 	len = irec->br_blockcount;
260 
261 	error = xchk_ag_init(info->sc, agno, &info->sc->sa);
262 	if (!xchk_fblock_process_error(info->sc, info->whichfork,
263 			irec->br_startoff, &error))
264 		return;
265 
266 	xchk_xref_is_used_space(info->sc, agbno, len);
267 	xchk_xref_is_not_inode_chunk(info->sc, agbno, len);
268 	xchk_bmap_xref_rmap(info, irec, agbno);
269 	switch (info->whichfork) {
270 	case XFS_DATA_FORK:
271 		if (xfs_is_reflink_inode(info->sc->ip))
272 			break;
273 		/* fall through */
274 	case XFS_ATTR_FORK:
275 		xchk_xref_is_not_shared(info->sc, agbno,
276 				irec->br_blockcount);
277 		break;
278 	case XFS_COW_FORK:
279 		xchk_xref_is_cow_staging(info->sc, agbno,
280 				irec->br_blockcount);
281 		break;
282 	}
283 
284 	xchk_ag_free(info->sc, &info->sc->sa);
285 }
286 
287 /*
288  * Directories and attr forks should never have blocks that can't be addressed
289  * by a xfs_dablk_t.
290  */
291 STATIC void
292 xchk_bmap_dirattr_extent(
293 	struct xfs_inode	*ip,
294 	struct xchk_bmap_info	*info,
295 	struct xfs_bmbt_irec	*irec)
296 {
297 	struct xfs_mount	*mp = ip->i_mount;
298 	xfs_fileoff_t		off;
299 
300 	if (!S_ISDIR(VFS_I(ip)->i_mode) && info->whichfork != XFS_ATTR_FORK)
301 		return;
302 
303 	if (!xfs_verify_dablk(mp, irec->br_startoff))
304 		xchk_fblock_set_corrupt(info->sc, info->whichfork,
305 				irec->br_startoff);
306 
307 	off = irec->br_startoff + irec->br_blockcount - 1;
308 	if (!xfs_verify_dablk(mp, off))
309 		xchk_fblock_set_corrupt(info->sc, info->whichfork, off);
310 }
311 
312 /* Scrub a single extent record. */
313 STATIC int
314 xchk_bmap_iextent(
315 	struct xfs_inode	*ip,
316 	struct xchk_bmap_info	*info,
317 	struct xfs_bmbt_irec	*irec)
318 {
319 	struct xfs_mount	*mp = info->sc->mp;
320 	xfs_filblks_t		end;
321 	int			error = 0;
322 
323 	/*
324 	 * Check for out-of-order extents.  This record could have come
325 	 * from the incore list, for which there is no ordering check.
326 	 */
327 	if (irec->br_startoff < info->lastoff)
328 		xchk_fblock_set_corrupt(info->sc, info->whichfork,
329 				irec->br_startoff);
330 
331 	xchk_bmap_dirattr_extent(ip, info, irec);
332 
333 	/* There should never be a "hole" extent in either extent list. */
334 	if (irec->br_startblock == HOLESTARTBLOCK)
335 		xchk_fblock_set_corrupt(info->sc, info->whichfork,
336 				irec->br_startoff);
337 
338 	/*
339 	 * Check for delalloc extents.  We never iterate the ones in the
340 	 * in-core extent scan, and we should never see these in the bmbt.
341 	 */
342 	if (isnullstartblock(irec->br_startblock))
343 		xchk_fblock_set_corrupt(info->sc, info->whichfork,
344 				irec->br_startoff);
345 
346 	/* Make sure the extent points to a valid place. */
347 	if (irec->br_blockcount > MAXEXTLEN)
348 		xchk_fblock_set_corrupt(info->sc, info->whichfork,
349 				irec->br_startoff);
350 	if (irec->br_startblock + irec->br_blockcount <= irec->br_startblock)
351 		xchk_fblock_set_corrupt(info->sc, info->whichfork,
352 				irec->br_startoff);
353 	end = irec->br_startblock + irec->br_blockcount - 1;
354 	if (info->is_rt &&
355 	    (!xfs_verify_rtbno(mp, irec->br_startblock) ||
356 	     !xfs_verify_rtbno(mp, end)))
357 		xchk_fblock_set_corrupt(info->sc, info->whichfork,
358 				irec->br_startoff);
359 	if (!info->is_rt &&
360 	    (!xfs_verify_fsbno(mp, irec->br_startblock) ||
361 	     !xfs_verify_fsbno(mp, end) ||
362 	     XFS_FSB_TO_AGNO(mp, irec->br_startblock) !=
363 				XFS_FSB_TO_AGNO(mp, end)))
364 		xchk_fblock_set_corrupt(info->sc, info->whichfork,
365 				irec->br_startoff);
366 
367 	/* We don't allow unwritten extents on attr forks. */
368 	if (irec->br_state == XFS_EXT_UNWRITTEN &&
369 	    info->whichfork == XFS_ATTR_FORK)
370 		xchk_fblock_set_corrupt(info->sc, info->whichfork,
371 				irec->br_startoff);
372 
373 	if (info->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
374 		return 0;
375 
376 	if (info->is_rt)
377 		xchk_bmap_rt_iextent_xref(ip, info, irec);
378 	else
379 		xchk_bmap_iextent_xref(ip, info, irec);
380 
381 	info->lastoff = irec->br_startoff + irec->br_blockcount;
382 	return error;
383 }
384 
385 /* Scrub a bmbt record. */
386 STATIC int
387 xchk_bmapbt_rec(
388 	struct xchk_btree	*bs,
389 	union xfs_btree_rec	*rec)
390 {
391 	struct xfs_bmbt_irec	irec;
392 	struct xfs_bmbt_irec	iext_irec;
393 	struct xfs_iext_cursor	icur;
394 	struct xchk_bmap_info	*info = bs->private;
395 	struct xfs_inode	*ip = bs->cur->bc_ino.ip;
396 	struct xfs_buf		*bp = NULL;
397 	struct xfs_btree_block	*block;
398 	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, info->whichfork);
399 	uint64_t		owner;
400 	int			i;
401 
402 	/*
403 	 * Check the owners of the btree blocks up to the level below
404 	 * the root since the verifiers don't do that.
405 	 */
406 	if (xfs_sb_version_hascrc(&bs->cur->bc_mp->m_sb) &&
407 	    bs->cur->bc_ptrs[0] == 1) {
408 		for (i = 0; i < bs->cur->bc_nlevels - 1; i++) {
409 			block = xfs_btree_get_block(bs->cur, i, &bp);
410 			owner = be64_to_cpu(block->bb_u.l.bb_owner);
411 			if (owner != ip->i_ino)
412 				xchk_fblock_set_corrupt(bs->sc,
413 						info->whichfork, 0);
414 		}
415 	}
416 
417 	/*
418 	 * Check that the incore extent tree contains an extent that matches
419 	 * this one exactly.  We validate those cached bmaps later, so we don't
420 	 * need to check them here.  If the incore extent tree was just loaded
421 	 * from disk by the scrubber, we assume that its contents match what's
422 	 * on disk (we still hold the ILOCK) and skip the equivalence check.
423 	 */
424 	if (!info->was_loaded)
425 		return 0;
426 
427 	xfs_bmbt_disk_get_all(&rec->bmbt, &irec);
428 	if (!xfs_iext_lookup_extent(ip, ifp, irec.br_startoff, &icur,
429 				&iext_irec) ||
430 	    irec.br_startoff != iext_irec.br_startoff ||
431 	    irec.br_startblock != iext_irec.br_startblock ||
432 	    irec.br_blockcount != iext_irec.br_blockcount ||
433 	    irec.br_state != iext_irec.br_state)
434 		xchk_fblock_set_corrupt(bs->sc, info->whichfork,
435 				irec.br_startoff);
436 	return 0;
437 }
438 
439 /* Scan the btree records. */
440 STATIC int
441 xchk_bmap_btree(
442 	struct xfs_scrub	*sc,
443 	int			whichfork,
444 	struct xchk_bmap_info	*info)
445 {
446 	struct xfs_owner_info	oinfo;
447 	struct xfs_ifork	*ifp = XFS_IFORK_PTR(sc->ip, whichfork);
448 	struct xfs_mount	*mp = sc->mp;
449 	struct xfs_inode	*ip = sc->ip;
450 	struct xfs_btree_cur	*cur;
451 	int			error;
452 
453 	/* Load the incore bmap cache if it's not loaded. */
454 	info->was_loaded = ifp->if_flags & XFS_IFEXTENTS;
455 	if (!info->was_loaded) {
456 		error = xfs_iread_extents(sc->tp, ip, whichfork);
457 		if (!xchk_fblock_process_error(sc, whichfork, 0, &error))
458 			goto out;
459 	}
460 
461 	/* Check the btree structure. */
462 	cur = xfs_bmbt_init_cursor(mp, sc->tp, ip, whichfork);
463 	xfs_rmap_ino_bmbt_owner(&oinfo, ip->i_ino, whichfork);
464 	error = xchk_btree(sc, cur, xchk_bmapbt_rec, &oinfo, info);
465 	xfs_btree_del_cursor(cur, error);
466 out:
467 	return error;
468 }
469 
470 struct xchk_bmap_check_rmap_info {
471 	struct xfs_scrub	*sc;
472 	int			whichfork;
473 	struct xfs_iext_cursor	icur;
474 };
475 
476 /* Can we find bmaps that fit this rmap? */
477 STATIC int
478 xchk_bmap_check_rmap(
479 	struct xfs_btree_cur		*cur,
480 	struct xfs_rmap_irec		*rec,
481 	void				*priv)
482 {
483 	struct xfs_bmbt_irec		irec;
484 	struct xchk_bmap_check_rmap_info	*sbcri = priv;
485 	struct xfs_ifork		*ifp;
486 	struct xfs_scrub		*sc = sbcri->sc;
487 	bool				have_map;
488 
489 	/* Is this even the right fork? */
490 	if (rec->rm_owner != sc->ip->i_ino)
491 		return 0;
492 	if ((sbcri->whichfork == XFS_ATTR_FORK) ^
493 	    !!(rec->rm_flags & XFS_RMAP_ATTR_FORK))
494 		return 0;
495 	if (rec->rm_flags & XFS_RMAP_BMBT_BLOCK)
496 		return 0;
497 
498 	/* Now look up the bmbt record. */
499 	ifp = XFS_IFORK_PTR(sc->ip, sbcri->whichfork);
500 	if (!ifp) {
501 		xchk_fblock_set_corrupt(sc, sbcri->whichfork,
502 				rec->rm_offset);
503 		goto out;
504 	}
505 	have_map = xfs_iext_lookup_extent(sc->ip, ifp, rec->rm_offset,
506 			&sbcri->icur, &irec);
507 	if (!have_map)
508 		xchk_fblock_set_corrupt(sc, sbcri->whichfork,
509 				rec->rm_offset);
510 	/*
511 	 * bmap extent record lengths are constrained to 2^21 blocks in length
512 	 * because of space constraints in the on-disk metadata structure.
513 	 * However, rmap extent record lengths are constrained only by AG
514 	 * length, so we have to loop through the bmbt to make sure that the
515 	 * entire rmap is covered by bmbt records.
516 	 */
517 	while (have_map) {
518 		if (irec.br_startoff != rec->rm_offset)
519 			xchk_fblock_set_corrupt(sc, sbcri->whichfork,
520 					rec->rm_offset);
521 		if (irec.br_startblock != XFS_AGB_TO_FSB(sc->mp,
522 				cur->bc_ag.agno, rec->rm_startblock))
523 			xchk_fblock_set_corrupt(sc, sbcri->whichfork,
524 					rec->rm_offset);
525 		if (irec.br_blockcount > rec->rm_blockcount)
526 			xchk_fblock_set_corrupt(sc, sbcri->whichfork,
527 					rec->rm_offset);
528 		if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
529 			break;
530 		rec->rm_startblock += irec.br_blockcount;
531 		rec->rm_offset += irec.br_blockcount;
532 		rec->rm_blockcount -= irec.br_blockcount;
533 		if (rec->rm_blockcount == 0)
534 			break;
535 		have_map = xfs_iext_next_extent(ifp, &sbcri->icur, &irec);
536 		if (!have_map)
537 			xchk_fblock_set_corrupt(sc, sbcri->whichfork,
538 					rec->rm_offset);
539 	}
540 
541 out:
542 	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
543 		return -ECANCELED;
544 	return 0;
545 }
546 
547 /* Make sure each rmap has a corresponding bmbt entry. */
548 STATIC int
549 xchk_bmap_check_ag_rmaps(
550 	struct xfs_scrub		*sc,
551 	int				whichfork,
552 	xfs_agnumber_t			agno)
553 {
554 	struct xchk_bmap_check_rmap_info	sbcri;
555 	struct xfs_btree_cur		*cur;
556 	struct xfs_buf			*agf;
557 	int				error;
558 
559 	error = xfs_alloc_read_agf(sc->mp, sc->tp, agno, 0, &agf);
560 	if (error)
561 		return error;
562 
563 	cur = xfs_rmapbt_init_cursor(sc->mp, sc->tp, agf, agno);
564 	if (!cur) {
565 		error = -ENOMEM;
566 		goto out_agf;
567 	}
568 
569 	sbcri.sc = sc;
570 	sbcri.whichfork = whichfork;
571 	error = xfs_rmap_query_all(cur, xchk_bmap_check_rmap, &sbcri);
572 	if (error == -ECANCELED)
573 		error = 0;
574 
575 	xfs_btree_del_cursor(cur, error);
576 out_agf:
577 	xfs_trans_brelse(sc->tp, agf);
578 	return error;
579 }
580 
581 /* Make sure each rmap has a corresponding bmbt entry. */
582 STATIC int
583 xchk_bmap_check_rmaps(
584 	struct xfs_scrub	*sc,
585 	int			whichfork)
586 {
587 	struct xfs_ifork	*ifp = XFS_IFORK_PTR(sc->ip, whichfork);
588 	xfs_agnumber_t		agno;
589 	bool			zero_size;
590 	int			error;
591 
592 	if (!xfs_sb_version_hasrmapbt(&sc->mp->m_sb) ||
593 	    whichfork == XFS_COW_FORK ||
594 	    (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
595 		return 0;
596 
597 	/* Don't support realtime rmap checks yet. */
598 	if (XFS_IS_REALTIME_INODE(sc->ip) && whichfork == XFS_DATA_FORK)
599 		return 0;
600 
601 	ASSERT(XFS_IFORK_PTR(sc->ip, whichfork) != NULL);
602 
603 	/*
604 	 * Only do this for complex maps that are in btree format, or for
605 	 * situations where we would seem to have a size but zero extents.
606 	 * The inode repair code can zap broken iforks, which means we have
607 	 * to flag this bmap as corrupt if there are rmaps that need to be
608 	 * reattached.
609 	 */
610 
611 	if (whichfork == XFS_DATA_FORK)
612 		zero_size = i_size_read(VFS_I(sc->ip)) == 0;
613 	else
614 		zero_size = false;
615 
616 	if (ifp->if_format != XFS_DINODE_FMT_BTREE &&
617 	    (zero_size || ifp->if_nextents > 0))
618 		return 0;
619 
620 	for (agno = 0; agno < sc->mp->m_sb.sb_agcount; agno++) {
621 		error = xchk_bmap_check_ag_rmaps(sc, whichfork, agno);
622 		if (error)
623 			return error;
624 		if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
625 			break;
626 	}
627 
628 	return 0;
629 }
630 
631 /*
632  * Scrub an inode fork's block mappings.
633  *
634  * First we scan every record in every btree block, if applicable.
635  * Then we unconditionally scan the incore extent cache.
636  */
637 STATIC int
638 xchk_bmap(
639 	struct xfs_scrub	*sc,
640 	int			whichfork)
641 {
642 	struct xfs_bmbt_irec	irec;
643 	struct xchk_bmap_info	info = { NULL };
644 	struct xfs_mount	*mp = sc->mp;
645 	struct xfs_inode	*ip = sc->ip;
646 	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
647 	xfs_fileoff_t		endoff;
648 	struct xfs_iext_cursor	icur;
649 	int			error = 0;
650 
651 	/* Non-existent forks can be ignored. */
652 	if (!ifp)
653 		goto out;
654 
655 	info.is_rt = whichfork == XFS_DATA_FORK && XFS_IS_REALTIME_INODE(ip);
656 	info.whichfork = whichfork;
657 	info.is_shared = whichfork == XFS_DATA_FORK && xfs_is_reflink_inode(ip);
658 	info.sc = sc;
659 
660 	switch (whichfork) {
661 	case XFS_COW_FORK:
662 		/* No CoW forks on non-reflink inodes/filesystems. */
663 		if (!xfs_is_reflink_inode(ip)) {
664 			xchk_ino_set_corrupt(sc, sc->ip->i_ino);
665 			goto out;
666 		}
667 		break;
668 	case XFS_ATTR_FORK:
669 		if (!xfs_sb_version_hasattr(&mp->m_sb) &&
670 		    !xfs_sb_version_hasattr2(&mp->m_sb))
671 			xchk_ino_set_corrupt(sc, sc->ip->i_ino);
672 		break;
673 	default:
674 		ASSERT(whichfork == XFS_DATA_FORK);
675 		break;
676 	}
677 
678 	/* Check the fork values */
679 	switch (ifp->if_format) {
680 	case XFS_DINODE_FMT_UUID:
681 	case XFS_DINODE_FMT_DEV:
682 	case XFS_DINODE_FMT_LOCAL:
683 		/* No mappings to check. */
684 		goto out;
685 	case XFS_DINODE_FMT_EXTENTS:
686 		if (!(ifp->if_flags & XFS_IFEXTENTS)) {
687 			xchk_fblock_set_corrupt(sc, whichfork, 0);
688 			goto out;
689 		}
690 		break;
691 	case XFS_DINODE_FMT_BTREE:
692 		if (whichfork == XFS_COW_FORK) {
693 			xchk_fblock_set_corrupt(sc, whichfork, 0);
694 			goto out;
695 		}
696 
697 		error = xchk_bmap_btree(sc, whichfork, &info);
698 		if (error)
699 			goto out;
700 		break;
701 	default:
702 		xchk_fblock_set_corrupt(sc, whichfork, 0);
703 		goto out;
704 	}
705 
706 	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
707 		goto out;
708 
709 	/* Find the offset of the last extent in the mapping. */
710 	error = xfs_bmap_last_offset(ip, &endoff, whichfork);
711 	if (!xchk_fblock_process_error(sc, whichfork, 0, &error))
712 		goto out;
713 
714 	/* Scrub extent records. */
715 	info.lastoff = 0;
716 	ifp = XFS_IFORK_PTR(ip, whichfork);
717 	for_each_xfs_iext(ifp, &icur, &irec) {
718 		if (xchk_should_terminate(sc, &error) ||
719 		    (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
720 			goto out;
721 		if (isnullstartblock(irec.br_startblock))
722 			continue;
723 		if (irec.br_startoff >= endoff) {
724 			xchk_fblock_set_corrupt(sc, whichfork,
725 					irec.br_startoff);
726 			goto out;
727 		}
728 		error = xchk_bmap_iextent(ip, &info, &irec);
729 		if (error)
730 			goto out;
731 	}
732 
733 	error = xchk_bmap_check_rmaps(sc, whichfork);
734 	if (!xchk_fblock_xref_process_error(sc, whichfork, 0, &error))
735 		goto out;
736 out:
737 	return error;
738 }
739 
740 /* Scrub an inode's data fork. */
741 int
742 xchk_bmap_data(
743 	struct xfs_scrub	*sc)
744 {
745 	return xchk_bmap(sc, XFS_DATA_FORK);
746 }
747 
748 /* Scrub an inode's attr fork. */
749 int
750 xchk_bmap_attr(
751 	struct xfs_scrub	*sc)
752 {
753 	return xchk_bmap(sc, XFS_ATTR_FORK);
754 }
755 
756 /* Scrub an inode's CoW fork. */
757 int
758 xchk_bmap_cow(
759 	struct xfs_scrub	*sc)
760 {
761 	if (!xfs_is_reflink_inode(sc->ip))
762 		return -ENOENT;
763 
764 	return xchk_bmap(sc, XFS_COW_FORK);
765 }
766