xref: /linux/fs/xfs/scrub/agheader.c (revision ef69f8d2ff09518657c3ecaf2db8408c16549829)
1 /*
2  * Copyright (C) 2017 Oracle.  All Rights Reserved.
3  *
4  * Author: Darrick J. Wong <darrick.wong@oracle.com>
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License
8  * as published by the Free Software Foundation; either version 2
9  * of the License, or (at your option) any later version.
10  *
11  * This program is distributed in the hope that it would be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write the Free Software Foundation,
18  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301, USA.
19  */
20 #include "xfs.h"
21 #include "xfs_fs.h"
22 #include "xfs_shared.h"
23 #include "xfs_format.h"
24 #include "xfs_trans_resv.h"
25 #include "xfs_mount.h"
26 #include "xfs_defer.h"
27 #include "xfs_btree.h"
28 #include "xfs_bit.h"
29 #include "xfs_log_format.h"
30 #include "xfs_trans.h"
31 #include "xfs_sb.h"
32 #include "xfs_inode.h"
33 #include "xfs_alloc.h"
34 #include "xfs_ialloc.h"
35 #include "scrub/xfs_scrub.h"
36 #include "scrub/scrub.h"
37 #include "scrub/common.h"
38 #include "scrub/trace.h"
39 
40 /*
41  * Set up scrub to check all the static metadata in each AG.
42  * This means the SB, AGF, AGI, and AGFL headers.
43  */
44 int
45 xfs_scrub_setup_ag_header(
46 	struct xfs_scrub_context	*sc,
47 	struct xfs_inode		*ip)
48 {
49 	struct xfs_mount		*mp = sc->mp;
50 
51 	if (sc->sm->sm_agno >= mp->m_sb.sb_agcount ||
52 	    sc->sm->sm_ino || sc->sm->sm_gen)
53 		return -EINVAL;
54 	return xfs_scrub_setup_fs(sc, ip);
55 }
56 
57 /* Walk all the blocks in the AGFL. */
58 int
59 xfs_scrub_walk_agfl(
60 	struct xfs_scrub_context	*sc,
61 	int				(*fn)(struct xfs_scrub_context *,
62 					      xfs_agblock_t bno, void *),
63 	void				*priv)
64 {
65 	struct xfs_agf			*agf;
66 	__be32				*agfl_bno;
67 	struct xfs_mount		*mp = sc->mp;
68 	unsigned int			flfirst;
69 	unsigned int			fllast;
70 	int				i;
71 	int				error;
72 
73 	agf = XFS_BUF_TO_AGF(sc->sa.agf_bp);
74 	agfl_bno = XFS_BUF_TO_AGFL_BNO(mp, sc->sa.agfl_bp);
75 	flfirst = be32_to_cpu(agf->agf_flfirst);
76 	fllast = be32_to_cpu(agf->agf_fllast);
77 
78 	/* Nothing to walk in an empty AGFL. */
79 	if (agf->agf_flcount == cpu_to_be32(0))
80 		return 0;
81 
82 	/* first to last is a consecutive list. */
83 	if (fllast >= flfirst) {
84 		for (i = flfirst; i <= fllast; i++) {
85 			error = fn(sc, be32_to_cpu(agfl_bno[i]), priv);
86 			if (error)
87 				return error;
88 			if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
89 				return error;
90 		}
91 
92 		return 0;
93 	}
94 
95 	/* first to the end */
96 	for (i = flfirst; i < XFS_AGFL_SIZE(mp); i++) {
97 		error = fn(sc, be32_to_cpu(agfl_bno[i]), priv);
98 		if (error)
99 			return error;
100 		if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
101 			return error;
102 	}
103 
104 	/* the start to last. */
105 	for (i = 0; i <= fllast; i++) {
106 		error = fn(sc, be32_to_cpu(agfl_bno[i]), priv);
107 		if (error)
108 			return error;
109 		if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
110 			return error;
111 	}
112 
113 	return 0;
114 }
115 
116 /* Superblock */
117 
118 /*
119  * Scrub the filesystem superblock.
120  *
121  * Note: We do /not/ attempt to check AG 0's superblock.  Mount is
122  * responsible for validating all the geometry information in sb 0, so
123  * if the filesystem is capable of initiating online scrub, then clearly
124  * sb 0 is ok and we can use its information to check everything else.
125  */
126 int
127 xfs_scrub_superblock(
128 	struct xfs_scrub_context	*sc)
129 {
130 	struct xfs_mount		*mp = sc->mp;
131 	struct xfs_buf			*bp;
132 	struct xfs_dsb			*sb;
133 	xfs_agnumber_t			agno;
134 	uint32_t			v2_ok;
135 	__be32				features_mask;
136 	int				error;
137 	__be16				vernum_mask;
138 
139 	agno = sc->sm->sm_agno;
140 	if (agno == 0)
141 		return 0;
142 
143 	error = xfs_trans_read_buf(mp, sc->tp, mp->m_ddev_targp,
144 		  XFS_AGB_TO_DADDR(mp, agno, XFS_SB_BLOCK(mp)),
145 		  XFS_FSS_TO_BB(mp, 1), 0, &bp, &xfs_sb_buf_ops);
146 	if (!xfs_scrub_process_error(sc, agno, XFS_SB_BLOCK(mp), &error))
147 		return error;
148 
149 	sb = XFS_BUF_TO_SBP(bp);
150 
151 	/*
152 	 * Verify the geometries match.  Fields that are permanently
153 	 * set by mkfs are checked; fields that can be updated later
154 	 * (and are not propagated to backup superblocks) are preen
155 	 * checked.
156 	 */
157 	if (sb->sb_blocksize != cpu_to_be32(mp->m_sb.sb_blocksize))
158 		xfs_scrub_block_set_corrupt(sc, bp);
159 
160 	if (sb->sb_dblocks != cpu_to_be64(mp->m_sb.sb_dblocks))
161 		xfs_scrub_block_set_corrupt(sc, bp);
162 
163 	if (sb->sb_rblocks != cpu_to_be64(mp->m_sb.sb_rblocks))
164 		xfs_scrub_block_set_corrupt(sc, bp);
165 
166 	if (sb->sb_rextents != cpu_to_be64(mp->m_sb.sb_rextents))
167 		xfs_scrub_block_set_corrupt(sc, bp);
168 
169 	if (!uuid_equal(&sb->sb_uuid, &mp->m_sb.sb_uuid))
170 		xfs_scrub_block_set_preen(sc, bp);
171 
172 	if (sb->sb_logstart != cpu_to_be64(mp->m_sb.sb_logstart))
173 		xfs_scrub_block_set_corrupt(sc, bp);
174 
175 	if (sb->sb_rootino != cpu_to_be64(mp->m_sb.sb_rootino))
176 		xfs_scrub_block_set_preen(sc, bp);
177 
178 	if (sb->sb_rbmino != cpu_to_be64(mp->m_sb.sb_rbmino))
179 		xfs_scrub_block_set_preen(sc, bp);
180 
181 	if (sb->sb_rsumino != cpu_to_be64(mp->m_sb.sb_rsumino))
182 		xfs_scrub_block_set_preen(sc, bp);
183 
184 	if (sb->sb_rextsize != cpu_to_be32(mp->m_sb.sb_rextsize))
185 		xfs_scrub_block_set_corrupt(sc, bp);
186 
187 	if (sb->sb_agblocks != cpu_to_be32(mp->m_sb.sb_agblocks))
188 		xfs_scrub_block_set_corrupt(sc, bp);
189 
190 	if (sb->sb_agcount != cpu_to_be32(mp->m_sb.sb_agcount))
191 		xfs_scrub_block_set_corrupt(sc, bp);
192 
193 	if (sb->sb_rbmblocks != cpu_to_be32(mp->m_sb.sb_rbmblocks))
194 		xfs_scrub_block_set_corrupt(sc, bp);
195 
196 	if (sb->sb_logblocks != cpu_to_be32(mp->m_sb.sb_logblocks))
197 		xfs_scrub_block_set_corrupt(sc, bp);
198 
199 	/* Check sb_versionnum bits that are set at mkfs time. */
200 	vernum_mask = cpu_to_be16(~XFS_SB_VERSION_OKBITS |
201 				  XFS_SB_VERSION_NUMBITS |
202 				  XFS_SB_VERSION_ALIGNBIT |
203 				  XFS_SB_VERSION_DALIGNBIT |
204 				  XFS_SB_VERSION_SHAREDBIT |
205 				  XFS_SB_VERSION_LOGV2BIT |
206 				  XFS_SB_VERSION_SECTORBIT |
207 				  XFS_SB_VERSION_EXTFLGBIT |
208 				  XFS_SB_VERSION_DIRV2BIT);
209 	if ((sb->sb_versionnum & vernum_mask) !=
210 	    (cpu_to_be16(mp->m_sb.sb_versionnum) & vernum_mask))
211 		xfs_scrub_block_set_corrupt(sc, bp);
212 
213 	/* Check sb_versionnum bits that can be set after mkfs time. */
214 	vernum_mask = cpu_to_be16(XFS_SB_VERSION_ATTRBIT |
215 				  XFS_SB_VERSION_NLINKBIT |
216 				  XFS_SB_VERSION_QUOTABIT);
217 	if ((sb->sb_versionnum & vernum_mask) !=
218 	    (cpu_to_be16(mp->m_sb.sb_versionnum) & vernum_mask))
219 		xfs_scrub_block_set_preen(sc, bp);
220 
221 	if (sb->sb_sectsize != cpu_to_be16(mp->m_sb.sb_sectsize))
222 		xfs_scrub_block_set_corrupt(sc, bp);
223 
224 	if (sb->sb_inodesize != cpu_to_be16(mp->m_sb.sb_inodesize))
225 		xfs_scrub_block_set_corrupt(sc, bp);
226 
227 	if (sb->sb_inopblock != cpu_to_be16(mp->m_sb.sb_inopblock))
228 		xfs_scrub_block_set_corrupt(sc, bp);
229 
230 	if (memcmp(sb->sb_fname, mp->m_sb.sb_fname, sizeof(sb->sb_fname)))
231 		xfs_scrub_block_set_preen(sc, bp);
232 
233 	if (sb->sb_blocklog != mp->m_sb.sb_blocklog)
234 		xfs_scrub_block_set_corrupt(sc, bp);
235 
236 	if (sb->sb_sectlog != mp->m_sb.sb_sectlog)
237 		xfs_scrub_block_set_corrupt(sc, bp);
238 
239 	if (sb->sb_inodelog != mp->m_sb.sb_inodelog)
240 		xfs_scrub_block_set_corrupt(sc, bp);
241 
242 	if (sb->sb_inopblog != mp->m_sb.sb_inopblog)
243 		xfs_scrub_block_set_corrupt(sc, bp);
244 
245 	if (sb->sb_agblklog != mp->m_sb.sb_agblklog)
246 		xfs_scrub_block_set_corrupt(sc, bp);
247 
248 	if (sb->sb_rextslog != mp->m_sb.sb_rextslog)
249 		xfs_scrub_block_set_corrupt(sc, bp);
250 
251 	if (sb->sb_imax_pct != mp->m_sb.sb_imax_pct)
252 		xfs_scrub_block_set_preen(sc, bp);
253 
254 	/*
255 	 * Skip the summary counters since we track them in memory anyway.
256 	 * sb_icount, sb_ifree, sb_fdblocks, sb_frexents
257 	 */
258 
259 	if (sb->sb_uquotino != cpu_to_be64(mp->m_sb.sb_uquotino))
260 		xfs_scrub_block_set_preen(sc, bp);
261 
262 	if (sb->sb_gquotino != cpu_to_be64(mp->m_sb.sb_gquotino))
263 		xfs_scrub_block_set_preen(sc, bp);
264 
265 	/*
266 	 * Skip the quota flags since repair will force quotacheck.
267 	 * sb_qflags
268 	 */
269 
270 	if (sb->sb_flags != mp->m_sb.sb_flags)
271 		xfs_scrub_block_set_corrupt(sc, bp);
272 
273 	if (sb->sb_shared_vn != mp->m_sb.sb_shared_vn)
274 		xfs_scrub_block_set_corrupt(sc, bp);
275 
276 	if (sb->sb_inoalignmt != cpu_to_be32(mp->m_sb.sb_inoalignmt))
277 		xfs_scrub_block_set_corrupt(sc, bp);
278 
279 	if (sb->sb_unit != cpu_to_be32(mp->m_sb.sb_unit))
280 		xfs_scrub_block_set_preen(sc, bp);
281 
282 	if (sb->sb_width != cpu_to_be32(mp->m_sb.sb_width))
283 		xfs_scrub_block_set_preen(sc, bp);
284 
285 	if (sb->sb_dirblklog != mp->m_sb.sb_dirblklog)
286 		xfs_scrub_block_set_corrupt(sc, bp);
287 
288 	if (sb->sb_logsectlog != mp->m_sb.sb_logsectlog)
289 		xfs_scrub_block_set_corrupt(sc, bp);
290 
291 	if (sb->sb_logsectsize != cpu_to_be16(mp->m_sb.sb_logsectsize))
292 		xfs_scrub_block_set_corrupt(sc, bp);
293 
294 	if (sb->sb_logsunit != cpu_to_be32(mp->m_sb.sb_logsunit))
295 		xfs_scrub_block_set_corrupt(sc, bp);
296 
297 	/* Do we see any invalid bits in sb_features2? */
298 	if (!xfs_sb_version_hasmorebits(&mp->m_sb)) {
299 		if (sb->sb_features2 != 0)
300 			xfs_scrub_block_set_corrupt(sc, bp);
301 	} else {
302 		v2_ok = XFS_SB_VERSION2_OKBITS;
303 		if (XFS_SB_VERSION_NUM(&mp->m_sb) >= XFS_SB_VERSION_5)
304 			v2_ok |= XFS_SB_VERSION2_CRCBIT;
305 
306 		if (!!(sb->sb_features2 & cpu_to_be32(~v2_ok)))
307 			xfs_scrub_block_set_corrupt(sc, bp);
308 
309 		if (sb->sb_features2 != sb->sb_bad_features2)
310 			xfs_scrub_block_set_preen(sc, bp);
311 	}
312 
313 	/* Check sb_features2 flags that are set at mkfs time. */
314 	features_mask = cpu_to_be32(XFS_SB_VERSION2_LAZYSBCOUNTBIT |
315 				    XFS_SB_VERSION2_PROJID32BIT |
316 				    XFS_SB_VERSION2_CRCBIT |
317 				    XFS_SB_VERSION2_FTYPE);
318 	if ((sb->sb_features2 & features_mask) !=
319 	    (cpu_to_be32(mp->m_sb.sb_features2) & features_mask))
320 		xfs_scrub_block_set_corrupt(sc, bp);
321 
322 	/* Check sb_features2 flags that can be set after mkfs time. */
323 	features_mask = cpu_to_be32(XFS_SB_VERSION2_ATTR2BIT);
324 	if ((sb->sb_features2 & features_mask) !=
325 	    (cpu_to_be32(mp->m_sb.sb_features2) & features_mask))
326 		xfs_scrub_block_set_corrupt(sc, bp);
327 
328 	if (!xfs_sb_version_hascrc(&mp->m_sb)) {
329 		/* all v5 fields must be zero */
330 		if (memchr_inv(&sb->sb_features_compat, 0,
331 				sizeof(struct xfs_dsb) -
332 				offsetof(struct xfs_dsb, sb_features_compat)))
333 			xfs_scrub_block_set_corrupt(sc, bp);
334 	} else {
335 		/* Check compat flags; all are set at mkfs time. */
336 		features_mask = cpu_to_be32(XFS_SB_FEAT_COMPAT_UNKNOWN);
337 		if ((sb->sb_features_compat & features_mask) !=
338 		    (cpu_to_be32(mp->m_sb.sb_features_compat) & features_mask))
339 			xfs_scrub_block_set_corrupt(sc, bp);
340 
341 		/* Check ro compat flags; all are set at mkfs time. */
342 		features_mask = cpu_to_be32(XFS_SB_FEAT_RO_COMPAT_UNKNOWN |
343 					    XFS_SB_FEAT_RO_COMPAT_FINOBT |
344 					    XFS_SB_FEAT_RO_COMPAT_RMAPBT |
345 					    XFS_SB_FEAT_RO_COMPAT_REFLINK);
346 		if ((sb->sb_features_ro_compat & features_mask) !=
347 		    (cpu_to_be32(mp->m_sb.sb_features_ro_compat) &
348 		     features_mask))
349 			xfs_scrub_block_set_corrupt(sc, bp);
350 
351 		/* Check incompat flags; all are set at mkfs time. */
352 		features_mask = cpu_to_be32(XFS_SB_FEAT_INCOMPAT_UNKNOWN |
353 					    XFS_SB_FEAT_INCOMPAT_FTYPE |
354 					    XFS_SB_FEAT_INCOMPAT_SPINODES |
355 					    XFS_SB_FEAT_INCOMPAT_META_UUID);
356 		if ((sb->sb_features_incompat & features_mask) !=
357 		    (cpu_to_be32(mp->m_sb.sb_features_incompat) &
358 		     features_mask))
359 			xfs_scrub_block_set_corrupt(sc, bp);
360 
361 		/* Check log incompat flags; all are set at mkfs time. */
362 		features_mask = cpu_to_be32(XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN);
363 		if ((sb->sb_features_log_incompat & features_mask) !=
364 		    (cpu_to_be32(mp->m_sb.sb_features_log_incompat) &
365 		     features_mask))
366 			xfs_scrub_block_set_corrupt(sc, bp);
367 
368 		/* Don't care about sb_crc */
369 
370 		if (sb->sb_spino_align != cpu_to_be32(mp->m_sb.sb_spino_align))
371 			xfs_scrub_block_set_corrupt(sc, bp);
372 
373 		if (sb->sb_pquotino != cpu_to_be64(mp->m_sb.sb_pquotino))
374 			xfs_scrub_block_set_preen(sc, bp);
375 
376 		/* Don't care about sb_lsn */
377 	}
378 
379 	if (xfs_sb_version_hasmetauuid(&mp->m_sb)) {
380 		/* The metadata UUID must be the same for all supers */
381 		if (!uuid_equal(&sb->sb_meta_uuid, &mp->m_sb.sb_meta_uuid))
382 			xfs_scrub_block_set_corrupt(sc, bp);
383 	}
384 
385 	/* Everything else must be zero. */
386 	if (memchr_inv(sb + 1, 0,
387 			BBTOB(bp->b_length) - sizeof(struct xfs_dsb)))
388 		xfs_scrub_block_set_corrupt(sc, bp);
389 
390 	return error;
391 }
392 
393 /* AGF */
394 
395 /* Scrub the AGF. */
396 int
397 xfs_scrub_agf(
398 	struct xfs_scrub_context	*sc)
399 {
400 	struct xfs_mount		*mp = sc->mp;
401 	struct xfs_agf			*agf;
402 	xfs_agnumber_t			agno;
403 	xfs_agblock_t			agbno;
404 	xfs_agblock_t			eoag;
405 	xfs_agblock_t			agfl_first;
406 	xfs_agblock_t			agfl_last;
407 	xfs_agblock_t			agfl_count;
408 	xfs_agblock_t			fl_count;
409 	int				level;
410 	int				error = 0;
411 
412 	agno = sc->sa.agno = sc->sm->sm_agno;
413 	error = xfs_scrub_ag_read_headers(sc, agno, &sc->sa.agi_bp,
414 			&sc->sa.agf_bp, &sc->sa.agfl_bp);
415 	if (!xfs_scrub_process_error(sc, agno, XFS_AGF_BLOCK(sc->mp), &error))
416 		goto out;
417 
418 	agf = XFS_BUF_TO_AGF(sc->sa.agf_bp);
419 
420 	/* Check the AG length */
421 	eoag = be32_to_cpu(agf->agf_length);
422 	if (eoag != xfs_ag_block_count(mp, agno))
423 		xfs_scrub_block_set_corrupt(sc, sc->sa.agf_bp);
424 
425 	/* Check the AGF btree roots and levels */
426 	agbno = be32_to_cpu(agf->agf_roots[XFS_BTNUM_BNO]);
427 	if (!xfs_verify_agbno(mp, agno, agbno))
428 		xfs_scrub_block_set_corrupt(sc, sc->sa.agf_bp);
429 
430 	agbno = be32_to_cpu(agf->agf_roots[XFS_BTNUM_CNT]);
431 	if (!xfs_verify_agbno(mp, agno, agbno))
432 		xfs_scrub_block_set_corrupt(sc, sc->sa.agf_bp);
433 
434 	level = be32_to_cpu(agf->agf_levels[XFS_BTNUM_BNO]);
435 	if (level <= 0 || level > XFS_BTREE_MAXLEVELS)
436 		xfs_scrub_block_set_corrupt(sc, sc->sa.agf_bp);
437 
438 	level = be32_to_cpu(agf->agf_levels[XFS_BTNUM_CNT]);
439 	if (level <= 0 || level > XFS_BTREE_MAXLEVELS)
440 		xfs_scrub_block_set_corrupt(sc, sc->sa.agf_bp);
441 
442 	if (xfs_sb_version_hasrmapbt(&mp->m_sb)) {
443 		agbno = be32_to_cpu(agf->agf_roots[XFS_BTNUM_RMAP]);
444 		if (!xfs_verify_agbno(mp, agno, agbno))
445 			xfs_scrub_block_set_corrupt(sc, sc->sa.agf_bp);
446 
447 		level = be32_to_cpu(agf->agf_levels[XFS_BTNUM_RMAP]);
448 		if (level <= 0 || level > XFS_BTREE_MAXLEVELS)
449 			xfs_scrub_block_set_corrupt(sc, sc->sa.agf_bp);
450 	}
451 
452 	if (xfs_sb_version_hasreflink(&mp->m_sb)) {
453 		agbno = be32_to_cpu(agf->agf_refcount_root);
454 		if (!xfs_verify_agbno(mp, agno, agbno))
455 			xfs_scrub_block_set_corrupt(sc, sc->sa.agf_bp);
456 
457 		level = be32_to_cpu(agf->agf_refcount_level);
458 		if (level <= 0 || level > XFS_BTREE_MAXLEVELS)
459 			xfs_scrub_block_set_corrupt(sc, sc->sa.agf_bp);
460 	}
461 
462 	/* Check the AGFL counters */
463 	agfl_first = be32_to_cpu(agf->agf_flfirst);
464 	agfl_last = be32_to_cpu(agf->agf_fllast);
465 	agfl_count = be32_to_cpu(agf->agf_flcount);
466 	if (agfl_last > agfl_first)
467 		fl_count = agfl_last - agfl_first + 1;
468 	else
469 		fl_count = XFS_AGFL_SIZE(mp) - agfl_first + agfl_last + 1;
470 	if (agfl_count != 0 && fl_count != agfl_count)
471 		xfs_scrub_block_set_corrupt(sc, sc->sa.agf_bp);
472 
473 out:
474 	return error;
475 }
476 
477 /* AGFL */
478 
479 struct xfs_scrub_agfl_info {
480 	unsigned int			sz_entries;
481 	unsigned int			nr_entries;
482 	xfs_agblock_t			*entries;
483 };
484 
485 /* Scrub an AGFL block. */
486 STATIC int
487 xfs_scrub_agfl_block(
488 	struct xfs_scrub_context	*sc,
489 	xfs_agblock_t			agbno,
490 	void				*priv)
491 {
492 	struct xfs_mount		*mp = sc->mp;
493 	struct xfs_scrub_agfl_info	*sai = priv;
494 	xfs_agnumber_t			agno = sc->sa.agno;
495 
496 	if (xfs_verify_agbno(mp, agno, agbno) &&
497 	    sai->nr_entries < sai->sz_entries)
498 		sai->entries[sai->nr_entries++] = agbno;
499 	else
500 		xfs_scrub_block_set_corrupt(sc, sc->sa.agfl_bp);
501 
502 	return 0;
503 }
504 
505 static int
506 xfs_scrub_agblock_cmp(
507 	const void		*pa,
508 	const void		*pb)
509 {
510 	const xfs_agblock_t	*a = pa;
511 	const xfs_agblock_t	*b = pb;
512 
513 	return (int)*a - (int)*b;
514 }
515 
516 /* Scrub the AGFL. */
517 int
518 xfs_scrub_agfl(
519 	struct xfs_scrub_context	*sc)
520 {
521 	struct xfs_scrub_agfl_info	sai = { 0 };
522 	struct xfs_agf			*agf;
523 	xfs_agnumber_t			agno;
524 	unsigned int			agflcount;
525 	unsigned int			i;
526 	int				error;
527 
528 	agno = sc->sa.agno = sc->sm->sm_agno;
529 	error = xfs_scrub_ag_read_headers(sc, agno, &sc->sa.agi_bp,
530 			&sc->sa.agf_bp, &sc->sa.agfl_bp);
531 	if (!xfs_scrub_process_error(sc, agno, XFS_AGFL_BLOCK(sc->mp), &error))
532 		goto out;
533 	if (!sc->sa.agf_bp)
534 		return -EFSCORRUPTED;
535 
536 	/* Allocate buffer to ensure uniqueness of AGFL entries. */
537 	agf = XFS_BUF_TO_AGF(sc->sa.agf_bp);
538 	agflcount = be32_to_cpu(agf->agf_flcount);
539 	if (agflcount > XFS_AGFL_SIZE(sc->mp)) {
540 		xfs_scrub_block_set_corrupt(sc, sc->sa.agf_bp);
541 		goto out;
542 	}
543 	sai.sz_entries = agflcount;
544 	sai.entries = kmem_zalloc(sizeof(xfs_agblock_t) * agflcount, KM_NOFS);
545 	if (!sai.entries) {
546 		error = -ENOMEM;
547 		goto out;
548 	}
549 
550 	/* Check the blocks in the AGFL. */
551 	error = xfs_scrub_walk_agfl(sc, xfs_scrub_agfl_block, &sai);
552 	if (error)
553 		goto out_free;
554 
555 	if (agflcount != sai.nr_entries) {
556 		xfs_scrub_block_set_corrupt(sc, sc->sa.agf_bp);
557 		goto out_free;
558 	}
559 
560 	/* Sort entries, check for duplicates. */
561 	sort(sai.entries, sai.nr_entries, sizeof(sai.entries[0]),
562 			xfs_scrub_agblock_cmp, NULL);
563 	for (i = 1; i < sai.nr_entries; i++) {
564 		if (sai.entries[i] == sai.entries[i - 1]) {
565 			xfs_scrub_block_set_corrupt(sc, sc->sa.agf_bp);
566 			break;
567 		}
568 	}
569 
570 out_free:
571 	kmem_free(sai.entries);
572 out:
573 	return error;
574 }
575 
576 /* AGI */
577 
578 /* Scrub the AGI. */
579 int
580 xfs_scrub_agi(
581 	struct xfs_scrub_context	*sc)
582 {
583 	struct xfs_mount		*mp = sc->mp;
584 	struct xfs_agi			*agi;
585 	xfs_agnumber_t			agno;
586 	xfs_agblock_t			agbno;
587 	xfs_agblock_t			eoag;
588 	xfs_agino_t			agino;
589 	xfs_agino_t			first_agino;
590 	xfs_agino_t			last_agino;
591 	xfs_agino_t			icount;
592 	int				i;
593 	int				level;
594 	int				error = 0;
595 
596 	agno = sc->sa.agno = sc->sm->sm_agno;
597 	error = xfs_scrub_ag_read_headers(sc, agno, &sc->sa.agi_bp,
598 			&sc->sa.agf_bp, &sc->sa.agfl_bp);
599 	if (!xfs_scrub_process_error(sc, agno, XFS_AGI_BLOCK(sc->mp), &error))
600 		goto out;
601 
602 	agi = XFS_BUF_TO_AGI(sc->sa.agi_bp);
603 
604 	/* Check the AG length */
605 	eoag = be32_to_cpu(agi->agi_length);
606 	if (eoag != xfs_ag_block_count(mp, agno))
607 		xfs_scrub_block_set_corrupt(sc, sc->sa.agi_bp);
608 
609 	/* Check btree roots and levels */
610 	agbno = be32_to_cpu(agi->agi_root);
611 	if (!xfs_verify_agbno(mp, agno, agbno))
612 		xfs_scrub_block_set_corrupt(sc, sc->sa.agi_bp);
613 
614 	level = be32_to_cpu(agi->agi_level);
615 	if (level <= 0 || level > XFS_BTREE_MAXLEVELS)
616 		xfs_scrub_block_set_corrupt(sc, sc->sa.agi_bp);
617 
618 	if (xfs_sb_version_hasfinobt(&mp->m_sb)) {
619 		agbno = be32_to_cpu(agi->agi_free_root);
620 		if (!xfs_verify_agbno(mp, agno, agbno))
621 			xfs_scrub_block_set_corrupt(sc, sc->sa.agi_bp);
622 
623 		level = be32_to_cpu(agi->agi_free_level);
624 		if (level <= 0 || level > XFS_BTREE_MAXLEVELS)
625 			xfs_scrub_block_set_corrupt(sc, sc->sa.agi_bp);
626 	}
627 
628 	/* Check inode counters */
629 	xfs_ialloc_agino_range(mp, agno, &first_agino, &last_agino);
630 	icount = be32_to_cpu(agi->agi_count);
631 	if (icount > last_agino - first_agino + 1 ||
632 	    icount < be32_to_cpu(agi->agi_freecount))
633 		xfs_scrub_block_set_corrupt(sc, sc->sa.agi_bp);
634 
635 	/* Check inode pointers */
636 	agino = be32_to_cpu(agi->agi_newino);
637 	if (agino != NULLAGINO && !xfs_verify_agino(mp, agno, agino))
638 		xfs_scrub_block_set_corrupt(sc, sc->sa.agi_bp);
639 
640 	agino = be32_to_cpu(agi->agi_dirino);
641 	if (agino != NULLAGINO && !xfs_verify_agino(mp, agno, agino))
642 		xfs_scrub_block_set_corrupt(sc, sc->sa.agi_bp);
643 
644 	/* Check unlinked inode buckets */
645 	for (i = 0; i < XFS_AGI_UNLINKED_BUCKETS; i++) {
646 		agino = be32_to_cpu(agi->agi_unlinked[i]);
647 		if (agino == NULLAGINO)
648 			continue;
649 		if (!xfs_verify_agino(mp, agno, agino))
650 			xfs_scrub_block_set_corrupt(sc, sc->sa.agi_bp);
651 	}
652 
653 	if (agi->agi_pad32 != cpu_to_be32(0))
654 		xfs_scrub_block_set_corrupt(sc, sc->sa.agi_bp);
655 
656 out:
657 	return error;
658 }
659