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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
xchk_setup_inode_bmap(struct xfs_scrub * sc,struct xfs_inode * ip)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
xchk_bmap_get_rmap(struct xchk_bmap_info * info,struct xfs_bmbt_irec * irec,xfs_agblock_t agbno,uint64_t owner,struct xfs_rmap_irec * rmap)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 	if (irec->br_state == XFS_EXT_UNWRITTEN)
117 		rflags |= XFS_RMAP_UNWRITTEN;
118 
119 	/*
120 	 * CoW staging extents are owned (on disk) by the refcountbt, so
121 	 * their rmaps do not have offsets.
122 	 */
123 	if (info->whichfork == XFS_COW_FORK)
124 		offset = 0;
125 	else
126 		offset = irec->br_startoff;
127 
128 	/*
129 	 * If the caller thinks this could be a shared bmbt extent (IOWs,
130 	 * any data fork extent of a reflink inode) then we have to use the
131 	 * range rmap lookup to make sure we get the correct owner/offset.
132 	 */
133 	if (info->is_shared) {
134 		error = xfs_rmap_lookup_le_range(info->sc->sa.rmap_cur, agbno,
135 				owner, offset, rflags, rmap, &has_rmap);
136 		if (!xchk_should_check_xref(info->sc, &error,
137 				&info->sc->sa.rmap_cur))
138 			return false;
139 		goto out;
140 	}
141 
142 	/*
143 	 * Otherwise, use the (faster) regular lookup.
144 	 */
145 	error = xfs_rmap_lookup_le(info->sc->sa.rmap_cur, agbno, 0, owner,
146 			offset, rflags, &has_rmap);
147 	if (!xchk_should_check_xref(info->sc, &error,
148 			&info->sc->sa.rmap_cur))
149 		return false;
150 	if (!has_rmap)
151 		goto out;
152 
153 	error = xfs_rmap_get_rec(info->sc->sa.rmap_cur, rmap, &has_rmap);
154 	if (!xchk_should_check_xref(info->sc, &error,
155 			&info->sc->sa.rmap_cur))
156 		return false;
157 
158 out:
159 	if (!has_rmap)
160 		xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
161 			irec->br_startoff);
162 	return has_rmap;
163 }
164 
165 /* Make sure that we have rmapbt records for this extent. */
166 STATIC void
xchk_bmap_xref_rmap(struct xchk_bmap_info * info,struct xfs_bmbt_irec * irec,xfs_agblock_t agbno)167 xchk_bmap_xref_rmap(
168 	struct xchk_bmap_info	*info,
169 	struct xfs_bmbt_irec	*irec,
170 	xfs_agblock_t		agbno)
171 {
172 	struct xfs_rmap_irec	rmap;
173 	unsigned long long	rmap_end;
174 	uint64_t		owner;
175 
176 	if (!info->sc->sa.rmap_cur || xchk_skip_xref(info->sc->sm))
177 		return;
178 
179 	if (info->whichfork == XFS_COW_FORK)
180 		owner = XFS_RMAP_OWN_COW;
181 	else
182 		owner = info->sc->ip->i_ino;
183 
184 	/* Find the rmap record for this irec. */
185 	if (!xchk_bmap_get_rmap(info, irec, agbno, owner, &rmap))
186 		return;
187 
188 	/* Check the rmap. */
189 	rmap_end = (unsigned long long)rmap.rm_startblock + rmap.rm_blockcount;
190 	if (rmap.rm_startblock > agbno ||
191 	    agbno + irec->br_blockcount > rmap_end)
192 		xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
193 				irec->br_startoff);
194 
195 	/*
196 	 * Check the logical offsets if applicable.  CoW staging extents
197 	 * don't track logical offsets since the mappings only exist in
198 	 * memory.
199 	 */
200 	if (info->whichfork != XFS_COW_FORK) {
201 		rmap_end = (unsigned long long)rmap.rm_offset +
202 				rmap.rm_blockcount;
203 		if (rmap.rm_offset > irec->br_startoff ||
204 		    irec->br_startoff + irec->br_blockcount > rmap_end)
205 			xchk_fblock_xref_set_corrupt(info->sc,
206 					info->whichfork, irec->br_startoff);
207 	}
208 
209 	if (rmap.rm_owner != owner)
210 		xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
211 				irec->br_startoff);
212 
213 	/*
214 	 * Check for discrepancies between the unwritten flag in the irec and
215 	 * the rmap.  Note that the (in-memory) CoW fork distinguishes between
216 	 * unwritten and written extents, but we don't track that in the rmap
217 	 * records because the blocks are owned (on-disk) by the refcountbt,
218 	 * which doesn't track unwritten state.
219 	 */
220 	if (owner != XFS_RMAP_OWN_COW &&
221 	    !!(irec->br_state == XFS_EXT_UNWRITTEN) !=
222 	    !!(rmap.rm_flags & XFS_RMAP_UNWRITTEN))
223 		xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
224 				irec->br_startoff);
225 
226 	if (!!(info->whichfork == XFS_ATTR_FORK) !=
227 	    !!(rmap.rm_flags & XFS_RMAP_ATTR_FORK))
228 		xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
229 				irec->br_startoff);
230 	if (rmap.rm_flags & XFS_RMAP_BMBT_BLOCK)
231 		xchk_fblock_xref_set_corrupt(info->sc, info->whichfork,
232 				irec->br_startoff);
233 }
234 
235 /* Cross-reference a single rtdev extent record. */
236 STATIC void
xchk_bmap_rt_iextent_xref(struct xfs_inode * ip,struct xchk_bmap_info * info,struct xfs_bmbt_irec * irec)237 xchk_bmap_rt_iextent_xref(
238 	struct xfs_inode	*ip,
239 	struct xchk_bmap_info	*info,
240 	struct xfs_bmbt_irec	*irec)
241 {
242 	xchk_xref_is_used_rt_space(info->sc, irec->br_startblock,
243 			irec->br_blockcount);
244 }
245 
246 /* Cross-reference a single datadev extent record. */
247 STATIC void
xchk_bmap_iextent_xref(struct xfs_inode * ip,struct xchk_bmap_info * info,struct xfs_bmbt_irec * irec)248 xchk_bmap_iextent_xref(
249 	struct xfs_inode	*ip,
250 	struct xchk_bmap_info	*info,
251 	struct xfs_bmbt_irec	*irec)
252 {
253 	struct xfs_mount	*mp = info->sc->mp;
254 	xfs_agnumber_t		agno;
255 	xfs_agblock_t		agbno;
256 	xfs_extlen_t		len;
257 	int			error;
258 
259 	agno = XFS_FSB_TO_AGNO(mp, irec->br_startblock);
260 	agbno = XFS_FSB_TO_AGBNO(mp, irec->br_startblock);
261 	len = irec->br_blockcount;
262 
263 	error = xchk_ag_init(info->sc, agno, &info->sc->sa);
264 	if (!xchk_fblock_process_error(info->sc, info->whichfork,
265 			irec->br_startoff, &error))
266 		return;
267 
268 	xchk_xref_is_used_space(info->sc, agbno, len);
269 	xchk_xref_is_not_inode_chunk(info->sc, agbno, len);
270 	xchk_bmap_xref_rmap(info, irec, agbno);
271 	switch (info->whichfork) {
272 	case XFS_DATA_FORK:
273 		if (xfs_is_reflink_inode(info->sc->ip))
274 			break;
275 		/* fall through */
276 	case XFS_ATTR_FORK:
277 		xchk_xref_is_not_shared(info->sc, agbno,
278 				irec->br_blockcount);
279 		break;
280 	case XFS_COW_FORK:
281 		xchk_xref_is_cow_staging(info->sc, agbno,
282 				irec->br_blockcount);
283 		break;
284 	}
285 
286 	xchk_ag_free(info->sc, &info->sc->sa);
287 }
288 
289 /*
290  * Directories and attr forks should never have blocks that can't be addressed
291  * by a xfs_dablk_t.
292  */
293 STATIC void
xchk_bmap_dirattr_extent(struct xfs_inode * ip,struct xchk_bmap_info * info,struct xfs_bmbt_irec * irec)294 xchk_bmap_dirattr_extent(
295 	struct xfs_inode	*ip,
296 	struct xchk_bmap_info	*info,
297 	struct xfs_bmbt_irec	*irec)
298 {
299 	struct xfs_mount	*mp = ip->i_mount;
300 	xfs_fileoff_t		off;
301 
302 	if (!S_ISDIR(VFS_I(ip)->i_mode) && info->whichfork != XFS_ATTR_FORK)
303 		return;
304 
305 	if (!xfs_verify_dablk(mp, irec->br_startoff))
306 		xchk_fblock_set_corrupt(info->sc, info->whichfork,
307 				irec->br_startoff);
308 
309 	off = irec->br_startoff + irec->br_blockcount - 1;
310 	if (!xfs_verify_dablk(mp, off))
311 		xchk_fblock_set_corrupt(info->sc, info->whichfork, off);
312 }
313 
314 /* Scrub a single extent record. */
315 STATIC int
xchk_bmap_iextent(struct xfs_inode * ip,struct xchk_bmap_info * info,struct xfs_bmbt_irec * irec)316 xchk_bmap_iextent(
317 	struct xfs_inode	*ip,
318 	struct xchk_bmap_info	*info,
319 	struct xfs_bmbt_irec	*irec)
320 {
321 	struct xfs_mount	*mp = info->sc->mp;
322 	xfs_filblks_t		end;
323 	int			error = 0;
324 
325 	/*
326 	 * Check for out-of-order extents.  This record could have come
327 	 * from the incore list, for which there is no ordering check.
328 	 */
329 	if (irec->br_startoff < info->lastoff)
330 		xchk_fblock_set_corrupt(info->sc, info->whichfork,
331 				irec->br_startoff);
332 
333 	xchk_bmap_dirattr_extent(ip, info, irec);
334 
335 	/* There should never be a "hole" extent in either extent list. */
336 	if (irec->br_startblock == HOLESTARTBLOCK)
337 		xchk_fblock_set_corrupt(info->sc, info->whichfork,
338 				irec->br_startoff);
339 
340 	/*
341 	 * Check for delalloc extents.  We never iterate the ones in the
342 	 * in-core extent scan, and we should never see these in the bmbt.
343 	 */
344 	if (isnullstartblock(irec->br_startblock))
345 		xchk_fblock_set_corrupt(info->sc, info->whichfork,
346 				irec->br_startoff);
347 
348 	/* Make sure the extent points to a valid place. */
349 	if (irec->br_blockcount > MAXEXTLEN)
350 		xchk_fblock_set_corrupt(info->sc, info->whichfork,
351 				irec->br_startoff);
352 	if (irec->br_startblock + irec->br_blockcount <= irec->br_startblock)
353 		xchk_fblock_set_corrupt(info->sc, info->whichfork,
354 				irec->br_startoff);
355 	end = irec->br_startblock + irec->br_blockcount - 1;
356 	if (info->is_rt &&
357 	    (!xfs_verify_rtbno(mp, irec->br_startblock) ||
358 	     !xfs_verify_rtbno(mp, end)))
359 		xchk_fblock_set_corrupt(info->sc, info->whichfork,
360 				irec->br_startoff);
361 	if (!info->is_rt &&
362 	    (!xfs_verify_fsbno(mp, irec->br_startblock) ||
363 	     !xfs_verify_fsbno(mp, end) ||
364 	     XFS_FSB_TO_AGNO(mp, irec->br_startblock) !=
365 				XFS_FSB_TO_AGNO(mp, end)))
366 		xchk_fblock_set_corrupt(info->sc, info->whichfork,
367 				irec->br_startoff);
368 
369 	/* We don't allow unwritten extents on attr forks. */
370 	if (irec->br_state == XFS_EXT_UNWRITTEN &&
371 	    info->whichfork == XFS_ATTR_FORK)
372 		xchk_fblock_set_corrupt(info->sc, info->whichfork,
373 				irec->br_startoff);
374 
375 	if (info->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
376 		return 0;
377 
378 	if (info->is_rt)
379 		xchk_bmap_rt_iextent_xref(ip, info, irec);
380 	else
381 		xchk_bmap_iextent_xref(ip, info, irec);
382 
383 	info->lastoff = irec->br_startoff + irec->br_blockcount;
384 	return error;
385 }
386 
387 /* Scrub a bmbt record. */
388 STATIC int
xchk_bmapbt_rec(struct xchk_btree * bs,union xfs_btree_rec * rec)389 xchk_bmapbt_rec(
390 	struct xchk_btree	*bs,
391 	union xfs_btree_rec	*rec)
392 {
393 	struct xfs_bmbt_irec	irec;
394 	struct xfs_bmbt_irec	iext_irec;
395 	struct xfs_iext_cursor	icur;
396 	struct xchk_bmap_info	*info = bs->private;
397 	struct xfs_inode	*ip = bs->cur->bc_ino.ip;
398 	struct xfs_buf		*bp = NULL;
399 	struct xfs_btree_block	*block;
400 	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, info->whichfork);
401 	uint64_t		owner;
402 	int			i;
403 
404 	/*
405 	 * Check the owners of the btree blocks up to the level below
406 	 * the root since the verifiers don't do that.
407 	 */
408 	if (xfs_sb_version_hascrc(&bs->cur->bc_mp->m_sb) &&
409 	    bs->cur->bc_ptrs[0] == 1) {
410 		for (i = 0; i < bs->cur->bc_nlevels - 1; i++) {
411 			block = xfs_btree_get_block(bs->cur, i, &bp);
412 			owner = be64_to_cpu(block->bb_u.l.bb_owner);
413 			if (owner != ip->i_ino)
414 				xchk_fblock_set_corrupt(bs->sc,
415 						info->whichfork, 0);
416 		}
417 	}
418 
419 	/*
420 	 * Check that the incore extent tree contains an extent that matches
421 	 * this one exactly.  We validate those cached bmaps later, so we don't
422 	 * need to check them here.  If the incore extent tree was just loaded
423 	 * from disk by the scrubber, we assume that its contents match what's
424 	 * on disk (we still hold the ILOCK) and skip the equivalence check.
425 	 */
426 	if (!info->was_loaded)
427 		return 0;
428 
429 	xfs_bmbt_disk_get_all(&rec->bmbt, &irec);
430 	if (!xfs_iext_lookup_extent(ip, ifp, irec.br_startoff, &icur,
431 				&iext_irec) ||
432 	    irec.br_startoff != iext_irec.br_startoff ||
433 	    irec.br_startblock != iext_irec.br_startblock ||
434 	    irec.br_blockcount != iext_irec.br_blockcount ||
435 	    irec.br_state != iext_irec.br_state)
436 		xchk_fblock_set_corrupt(bs->sc, info->whichfork,
437 				irec.br_startoff);
438 	return 0;
439 }
440 
441 /* Scan the btree records. */
442 STATIC int
xchk_bmap_btree(struct xfs_scrub * sc,int whichfork,struct xchk_bmap_info * info)443 xchk_bmap_btree(
444 	struct xfs_scrub	*sc,
445 	int			whichfork,
446 	struct xchk_bmap_info	*info)
447 {
448 	struct xfs_owner_info	oinfo;
449 	struct xfs_ifork	*ifp = XFS_IFORK_PTR(sc->ip, whichfork);
450 	struct xfs_mount	*mp = sc->mp;
451 	struct xfs_inode	*ip = sc->ip;
452 	struct xfs_btree_cur	*cur;
453 	int			error;
454 
455 	/* Load the incore bmap cache if it's not loaded. */
456 	info->was_loaded = ifp->if_flags & XFS_IFEXTENTS;
457 	if (!info->was_loaded) {
458 		error = xfs_iread_extents(sc->tp, ip, whichfork);
459 		if (!xchk_fblock_process_error(sc, whichfork, 0, &error))
460 			goto out;
461 	}
462 
463 	/* Check the btree structure. */
464 	cur = xfs_bmbt_init_cursor(mp, sc->tp, ip, whichfork);
465 	xfs_rmap_ino_bmbt_owner(&oinfo, ip->i_ino, whichfork);
466 	error = xchk_btree(sc, cur, xchk_bmapbt_rec, &oinfo, info);
467 	xfs_btree_del_cursor(cur, error);
468 out:
469 	return error;
470 }
471 
472 struct xchk_bmap_check_rmap_info {
473 	struct xfs_scrub	*sc;
474 	int			whichfork;
475 	struct xfs_iext_cursor	icur;
476 };
477 
478 /* Can we find bmaps that fit this rmap? */
479 STATIC int
xchk_bmap_check_rmap(struct xfs_btree_cur * cur,struct xfs_rmap_irec * rec,void * priv)480 xchk_bmap_check_rmap(
481 	struct xfs_btree_cur		*cur,
482 	struct xfs_rmap_irec		*rec,
483 	void				*priv)
484 {
485 	struct xfs_bmbt_irec		irec;
486 	struct xchk_bmap_check_rmap_info	*sbcri = priv;
487 	struct xfs_ifork		*ifp;
488 	struct xfs_scrub		*sc = sbcri->sc;
489 	bool				have_map;
490 
491 	/* Is this even the right fork? */
492 	if (rec->rm_owner != sc->ip->i_ino)
493 		return 0;
494 	if ((sbcri->whichfork == XFS_ATTR_FORK) ^
495 	    !!(rec->rm_flags & XFS_RMAP_ATTR_FORK))
496 		return 0;
497 	if (rec->rm_flags & XFS_RMAP_BMBT_BLOCK)
498 		return 0;
499 
500 	/* Now look up the bmbt record. */
501 	ifp = XFS_IFORK_PTR(sc->ip, sbcri->whichfork);
502 	if (!ifp) {
503 		xchk_fblock_set_corrupt(sc, sbcri->whichfork,
504 				rec->rm_offset);
505 		goto out;
506 	}
507 	have_map = xfs_iext_lookup_extent(sc->ip, ifp, rec->rm_offset,
508 			&sbcri->icur, &irec);
509 	if (!have_map)
510 		xchk_fblock_set_corrupt(sc, sbcri->whichfork,
511 				rec->rm_offset);
512 	/*
513 	 * bmap extent record lengths are constrained to 2^21 blocks in length
514 	 * because of space constraints in the on-disk metadata structure.
515 	 * However, rmap extent record lengths are constrained only by AG
516 	 * length, so we have to loop through the bmbt to make sure that the
517 	 * entire rmap is covered by bmbt records.
518 	 */
519 	while (have_map) {
520 		if (irec.br_startoff != rec->rm_offset)
521 			xchk_fblock_set_corrupt(sc, sbcri->whichfork,
522 					rec->rm_offset);
523 		if (irec.br_startblock != XFS_AGB_TO_FSB(sc->mp,
524 				cur->bc_ag.agno, rec->rm_startblock))
525 			xchk_fblock_set_corrupt(sc, sbcri->whichfork,
526 					rec->rm_offset);
527 		if (irec.br_blockcount > rec->rm_blockcount)
528 			xchk_fblock_set_corrupt(sc, sbcri->whichfork,
529 					rec->rm_offset);
530 		if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
531 			break;
532 		rec->rm_startblock += irec.br_blockcount;
533 		rec->rm_offset += irec.br_blockcount;
534 		rec->rm_blockcount -= irec.br_blockcount;
535 		if (rec->rm_blockcount == 0)
536 			break;
537 		have_map = xfs_iext_next_extent(ifp, &sbcri->icur, &irec);
538 		if (!have_map)
539 			xchk_fblock_set_corrupt(sc, sbcri->whichfork,
540 					rec->rm_offset);
541 	}
542 
543 out:
544 	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
545 		return -ECANCELED;
546 	return 0;
547 }
548 
549 /* Make sure each rmap has a corresponding bmbt entry. */
550 STATIC int
xchk_bmap_check_ag_rmaps(struct xfs_scrub * sc,int whichfork,xfs_agnumber_t agno)551 xchk_bmap_check_ag_rmaps(
552 	struct xfs_scrub		*sc,
553 	int				whichfork,
554 	xfs_agnumber_t			agno)
555 {
556 	struct xchk_bmap_check_rmap_info	sbcri;
557 	struct xfs_btree_cur		*cur;
558 	struct xfs_buf			*agf;
559 	int				error;
560 
561 	error = xfs_alloc_read_agf(sc->mp, sc->tp, agno, 0, &agf);
562 	if (error)
563 		return error;
564 
565 	cur = xfs_rmapbt_init_cursor(sc->mp, sc->tp, agf, agno);
566 	if (!cur) {
567 		error = -ENOMEM;
568 		goto out_agf;
569 	}
570 
571 	sbcri.sc = sc;
572 	sbcri.whichfork = whichfork;
573 	error = xfs_rmap_query_all(cur, xchk_bmap_check_rmap, &sbcri);
574 	if (error == -ECANCELED)
575 		error = 0;
576 
577 	xfs_btree_del_cursor(cur, error);
578 out_agf:
579 	xfs_trans_brelse(sc->tp, agf);
580 	return error;
581 }
582 
583 /* Make sure each rmap has a corresponding bmbt entry. */
584 STATIC int
xchk_bmap_check_rmaps(struct xfs_scrub * sc,int whichfork)585 xchk_bmap_check_rmaps(
586 	struct xfs_scrub	*sc,
587 	int			whichfork)
588 {
589 	struct xfs_ifork	*ifp = XFS_IFORK_PTR(sc->ip, whichfork);
590 	xfs_agnumber_t		agno;
591 	bool			zero_size;
592 	int			error;
593 
594 	if (!xfs_sb_version_hasrmapbt(&sc->mp->m_sb) ||
595 	    whichfork == XFS_COW_FORK ||
596 	    (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
597 		return 0;
598 
599 	/* Don't support realtime rmap checks yet. */
600 	if (XFS_IS_REALTIME_INODE(sc->ip) && whichfork == XFS_DATA_FORK)
601 		return 0;
602 
603 	ASSERT(XFS_IFORK_PTR(sc->ip, whichfork) != NULL);
604 
605 	/*
606 	 * Only do this for complex maps that are in btree format, or for
607 	 * situations where we would seem to have a size but zero extents.
608 	 * The inode repair code can zap broken iforks, which means we have
609 	 * to flag this bmap as corrupt if there are rmaps that need to be
610 	 * reattached.
611 	 */
612 
613 	if (whichfork == XFS_DATA_FORK)
614 		zero_size = i_size_read(VFS_I(sc->ip)) == 0;
615 	else
616 		zero_size = false;
617 
618 	if (ifp->if_format != XFS_DINODE_FMT_BTREE &&
619 	    (zero_size || ifp->if_nextents > 0))
620 		return 0;
621 
622 	for (agno = 0; agno < sc->mp->m_sb.sb_agcount; agno++) {
623 		error = xchk_bmap_check_ag_rmaps(sc, whichfork, agno);
624 		if (error)
625 			return error;
626 		if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
627 			break;
628 	}
629 
630 	return 0;
631 }
632 
633 /*
634  * Scrub an inode fork's block mappings.
635  *
636  * First we scan every record in every btree block, if applicable.
637  * Then we unconditionally scan the incore extent cache.
638  */
639 STATIC int
xchk_bmap(struct xfs_scrub * sc,int whichfork)640 xchk_bmap(
641 	struct xfs_scrub	*sc,
642 	int			whichfork)
643 {
644 	struct xfs_bmbt_irec	irec;
645 	struct xchk_bmap_info	info = { NULL };
646 	struct xfs_mount	*mp = sc->mp;
647 	struct xfs_inode	*ip = sc->ip;
648 	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
649 	xfs_fileoff_t		endoff;
650 	struct xfs_iext_cursor	icur;
651 	int			error = 0;
652 
653 	/* Non-existent forks can be ignored. */
654 	if (!ifp)
655 		goto out;
656 
657 	info.is_rt = whichfork == XFS_DATA_FORK && XFS_IS_REALTIME_INODE(ip);
658 	info.whichfork = whichfork;
659 	info.is_shared = whichfork == XFS_DATA_FORK && xfs_is_reflink_inode(ip);
660 	info.sc = sc;
661 
662 	switch (whichfork) {
663 	case XFS_COW_FORK:
664 		/* No CoW forks on non-reflink inodes/filesystems. */
665 		if (!xfs_is_reflink_inode(ip)) {
666 			xchk_ino_set_corrupt(sc, sc->ip->i_ino);
667 			goto out;
668 		}
669 		break;
670 	case XFS_ATTR_FORK:
671 		if (!xfs_sb_version_hasattr(&mp->m_sb) &&
672 		    !xfs_sb_version_hasattr2(&mp->m_sb))
673 			xchk_ino_set_corrupt(sc, sc->ip->i_ino);
674 		break;
675 	default:
676 		ASSERT(whichfork == XFS_DATA_FORK);
677 		break;
678 	}
679 
680 	/* Check the fork values */
681 	switch (ifp->if_format) {
682 	case XFS_DINODE_FMT_UUID:
683 	case XFS_DINODE_FMT_DEV:
684 	case XFS_DINODE_FMT_LOCAL:
685 		/* No mappings to check. */
686 		goto out;
687 	case XFS_DINODE_FMT_EXTENTS:
688 		if (!(ifp->if_flags & XFS_IFEXTENTS)) {
689 			xchk_fblock_set_corrupt(sc, whichfork, 0);
690 			goto out;
691 		}
692 		break;
693 	case XFS_DINODE_FMT_BTREE:
694 		if (whichfork == XFS_COW_FORK) {
695 			xchk_fblock_set_corrupt(sc, whichfork, 0);
696 			goto out;
697 		}
698 
699 		error = xchk_bmap_btree(sc, whichfork, &info);
700 		if (error)
701 			goto out;
702 		break;
703 	default:
704 		xchk_fblock_set_corrupt(sc, whichfork, 0);
705 		goto out;
706 	}
707 
708 	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
709 		goto out;
710 
711 	/* Find the offset of the last extent in the mapping. */
712 	error = xfs_bmap_last_offset(ip, &endoff, whichfork);
713 	if (!xchk_fblock_process_error(sc, whichfork, 0, &error))
714 		goto out;
715 
716 	/* Scrub extent records. */
717 	info.lastoff = 0;
718 	ifp = XFS_IFORK_PTR(ip, whichfork);
719 	for_each_xfs_iext(ifp, &icur, &irec) {
720 		if (xchk_should_terminate(sc, &error) ||
721 		    (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT))
722 			goto out;
723 		if (isnullstartblock(irec.br_startblock))
724 			continue;
725 		if (irec.br_startoff >= endoff) {
726 			xchk_fblock_set_corrupt(sc, whichfork,
727 					irec.br_startoff);
728 			goto out;
729 		}
730 		error = xchk_bmap_iextent(ip, &info, &irec);
731 		if (error)
732 			goto out;
733 	}
734 
735 	error = xchk_bmap_check_rmaps(sc, whichfork);
736 	if (!xchk_fblock_xref_process_error(sc, whichfork, 0, &error))
737 		goto out;
738 out:
739 	return error;
740 }
741 
742 /* Scrub an inode's data fork. */
743 int
xchk_bmap_data(struct xfs_scrub * sc)744 xchk_bmap_data(
745 	struct xfs_scrub	*sc)
746 {
747 	return xchk_bmap(sc, XFS_DATA_FORK);
748 }
749 
750 /* Scrub an inode's attr fork. */
751 int
xchk_bmap_attr(struct xfs_scrub * sc)752 xchk_bmap_attr(
753 	struct xfs_scrub	*sc)
754 {
755 	return xchk_bmap(sc, XFS_ATTR_FORK);
756 }
757 
758 /* Scrub an inode's CoW fork. */
759 int
xchk_bmap_cow(struct xfs_scrub * sc)760 xchk_bmap_cow(
761 	struct xfs_scrub	*sc)
762 {
763 	if (!xfs_is_reflink_inode(sc->ip))
764 		return -ENOENT;
765 
766 	return xchk_bmap(sc, XFS_COW_FORK);
767 }
768