xref: /linux/fs/xfs/scrub/inode.c (revision 7f71507851fc7764b36a3221839607d3a45c2025)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Copyright (C) 2017-2023 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_trans_resv.h"
11 #include "xfs_mount.h"
12 #include "xfs_btree.h"
13 #include "xfs_log_format.h"
14 #include "xfs_trans.h"
15 #include "xfs_ag.h"
16 #include "xfs_inode.h"
17 #include "xfs_ialloc.h"
18 #include "xfs_icache.h"
19 #include "xfs_da_format.h"
20 #include "xfs_reflink.h"
21 #include "xfs_rmap.h"
22 #include "xfs_bmap_util.h"
23 #include "xfs_rtbitmap.h"
24 #include "scrub/scrub.h"
25 #include "scrub/common.h"
26 #include "scrub/btree.h"
27 #include "scrub/trace.h"
28 #include "scrub/repair.h"
29 
30 /* Prepare the attached inode for scrubbing. */
31 static inline int
32 xchk_prepare_iscrub(
33 	struct xfs_scrub	*sc)
34 {
35 	int			error;
36 
37 	xchk_ilock(sc, XFS_IOLOCK_EXCL);
38 
39 	error = xchk_trans_alloc(sc, 0);
40 	if (error)
41 		return error;
42 
43 	error = xchk_ino_dqattach(sc);
44 	if (error)
45 		return error;
46 
47 	xchk_ilock(sc, XFS_ILOCK_EXCL);
48 	return 0;
49 }
50 
51 /* Install this scrub-by-handle inode and prepare it for scrubbing. */
52 static inline int
53 xchk_install_handle_iscrub(
54 	struct xfs_scrub	*sc,
55 	struct xfs_inode	*ip)
56 {
57 	int			error;
58 
59 	error = xchk_install_handle_inode(sc, ip);
60 	if (error)
61 		return error;
62 
63 	/*
64 	 * Don't allow scrubbing by handle of any non-directory inode records
65 	 * in the metadata directory tree.  We don't know if any of the scans
66 	 * launched by this scrubber will end up indirectly trying to lock this
67 	 * file.
68 	 *
69 	 * Scrubbers of inode-rooted metadata files (e.g. quota files) will
70 	 * attach all the resources needed to scrub the inode and call
71 	 * xchk_inode directly.  Userspace cannot call this directly.
72 	 */
73 	if (xfs_is_metadir_inode(ip) && !S_ISDIR(VFS_I(ip)->i_mode)) {
74 		xchk_irele(sc, ip);
75 		sc->ip = NULL;
76 		return -ENOENT;
77 	}
78 
79 	return xchk_prepare_iscrub(sc);
80 }
81 
82 /*
83  * Grab total control of the inode metadata.  In the best case, we grab the
84  * incore inode and take all locks on it.  If the incore inode cannot be
85  * constructed due to corruption problems, lock the AGI so that we can single
86  * step the loading process to fix everything that can go wrong.
87  */
88 int
89 xchk_setup_inode(
90 	struct xfs_scrub	*sc)
91 {
92 	struct xfs_imap		imap;
93 	struct xfs_inode	*ip;
94 	struct xfs_mount	*mp = sc->mp;
95 	struct xfs_inode	*ip_in = XFS_I(file_inode(sc->file));
96 	struct xfs_buf		*agi_bp;
97 	struct xfs_perag	*pag;
98 	xfs_agnumber_t		agno = XFS_INO_TO_AGNO(mp, sc->sm->sm_ino);
99 	int			error;
100 
101 	if (xchk_need_intent_drain(sc))
102 		xchk_fsgates_enable(sc, XCHK_FSGATES_DRAIN);
103 
104 	/* We want to scan the opened inode, so lock it and exit. */
105 	if (sc->sm->sm_ino == 0 || sc->sm->sm_ino == ip_in->i_ino) {
106 		error = xchk_install_live_inode(sc, ip_in);
107 		if (error)
108 			return error;
109 
110 		return xchk_prepare_iscrub(sc);
111 	}
112 
113 	/*
114 	 * On pre-metadir filesystems, reject internal metadata files.  For
115 	 * metadir filesystems, limited scrubbing of any file in the metadata
116 	 * directory tree by handle is allowed, because that is the only way to
117 	 * validate the lack of parent pointers in the sb-root metadata inodes.
118 	 */
119 	if (!xfs_has_metadir(mp) && xfs_is_sb_inum(mp, sc->sm->sm_ino))
120 		return -ENOENT;
121 	/* Reject obviously bad inode numbers. */
122 	if (!xfs_verify_ino(sc->mp, sc->sm->sm_ino))
123 		return -ENOENT;
124 
125 	/* Try a safe untrusted iget. */
126 	error = xchk_iget_safe(sc, sc->sm->sm_ino, &ip);
127 	if (!error)
128 		return xchk_install_handle_iscrub(sc, ip);
129 	if (error == -ENOENT)
130 		return error;
131 	if (error != -EFSCORRUPTED && error != -EFSBADCRC && error != -EINVAL)
132 		goto out_error;
133 
134 	/*
135 	 * EINVAL with IGET_UNTRUSTED probably means one of several things:
136 	 * userspace gave us an inode number that doesn't correspond to fs
137 	 * space; the inode btree lacks a record for this inode; or there is
138 	 * a record, and it says this inode is free.
139 	 *
140 	 * EFSCORRUPTED/EFSBADCRC could mean that the inode was mappable, but
141 	 * some other metadata corruption (e.g. inode forks) prevented
142 	 * instantiation of the incore inode.  Or it could mean the inobt is
143 	 * corrupt.
144 	 *
145 	 * We want to look up this inode in the inobt directly to distinguish
146 	 * three different scenarios: (1) the inobt says the inode is free,
147 	 * in which case there's nothing to do; (2) the inobt is corrupt so we
148 	 * should flag the corruption and exit to userspace to let it fix the
149 	 * inobt; and (3) the inobt says the inode is allocated, but loading it
150 	 * failed due to corruption.
151 	 *
152 	 * Allocate a transaction and grab the AGI to prevent inobt activity in
153 	 * this AG.  Retry the iget in case someone allocated a new inode after
154 	 * the first iget failed.
155 	 */
156 	error = xchk_trans_alloc(sc, 0);
157 	if (error)
158 		goto out_error;
159 
160 	error = xchk_iget_agi(sc, sc->sm->sm_ino, &agi_bp, &ip);
161 	if (error == 0) {
162 		/* Actually got the incore inode, so install it and proceed. */
163 		xchk_trans_cancel(sc);
164 		return xchk_install_handle_iscrub(sc, ip);
165 	}
166 	if (error == -ENOENT)
167 		goto out_gone;
168 	if (error != -EFSCORRUPTED && error != -EFSBADCRC && error != -EINVAL)
169 		goto out_cancel;
170 
171 	/* Ensure that we have protected against inode allocation/freeing. */
172 	if (agi_bp == NULL) {
173 		ASSERT(agi_bp != NULL);
174 		error = -ECANCELED;
175 		goto out_cancel;
176 	}
177 
178 	/*
179 	 * Untrusted iget failed a second time.  Let's try an inobt lookup.
180 	 * If the inobt doesn't think this is an allocated inode then we'll
181 	 * return ENOENT to signal that the check can be skipped.
182 	 *
183 	 * If the lookup signals corruption, we'll mark this inode corrupt and
184 	 * exit to userspace.  There's little chance of fixing anything until
185 	 * the inobt is straightened out, but there's nothing we can do here.
186 	 *
187 	 * If the lookup encounters a runtime error, exit to userspace.
188 	 */
189 	pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, sc->sm->sm_ino));
190 	if (!pag) {
191 		error = -EFSCORRUPTED;
192 		goto out_cancel;
193 	}
194 
195 	error = xfs_imap(pag, sc->tp, sc->sm->sm_ino, &imap,
196 			XFS_IGET_UNTRUSTED);
197 	xfs_perag_put(pag);
198 	if (error == -EINVAL || error == -ENOENT)
199 		goto out_gone;
200 	if (error)
201 		goto out_cancel;
202 
203 	/*
204 	 * The lookup succeeded.  Chances are the ondisk inode is corrupt and
205 	 * preventing iget from reading it.  Retain the scrub transaction and
206 	 * the AGI buffer to prevent anyone from allocating or freeing inodes.
207 	 * This ensures that we preserve the inconsistency between the inobt
208 	 * saying the inode is allocated and the icache being unable to load
209 	 * the inode until we can flag the corruption in xchk_inode.  The
210 	 * scrub function has to note the corruption, since we're not really
211 	 * supposed to do that from the setup function.  Save the mapping to
212 	 * make repairs to the ondisk inode buffer.
213 	 */
214 	if (xchk_could_repair(sc))
215 		xrep_setup_inode(sc, &imap);
216 	return 0;
217 
218 out_cancel:
219 	xchk_trans_cancel(sc);
220 out_error:
221 	trace_xchk_op_error(sc, agno, XFS_INO_TO_AGBNO(mp, sc->sm->sm_ino),
222 			error, __return_address);
223 	return error;
224 out_gone:
225 	/* The file is gone, so there's nothing to check. */
226 	xchk_trans_cancel(sc);
227 	return -ENOENT;
228 }
229 
230 /* Inode core */
231 
232 /* Validate di_extsize hint. */
233 STATIC void
234 xchk_inode_extsize(
235 	struct xfs_scrub	*sc,
236 	struct xfs_dinode	*dip,
237 	xfs_ino_t		ino,
238 	uint16_t		mode,
239 	uint16_t		flags)
240 {
241 	xfs_failaddr_t		fa;
242 	uint32_t		value = be32_to_cpu(dip->di_extsize);
243 
244 	fa = xfs_inode_validate_extsize(sc->mp, value, mode, flags);
245 	if (fa)
246 		xchk_ino_set_corrupt(sc, ino);
247 
248 	/*
249 	 * XFS allows a sysadmin to change the rt extent size when adding a rt
250 	 * section to a filesystem after formatting.  If there are any
251 	 * directories with extszinherit and rtinherit set, the hint could
252 	 * become misaligned with the new rextsize.  The verifier doesn't check
253 	 * this, because we allow rtinherit directories even without an rt
254 	 * device.  Flag this as an administrative warning since we will clean
255 	 * this up eventually.
256 	 */
257 	if ((flags & XFS_DIFLAG_RTINHERIT) &&
258 	    (flags & XFS_DIFLAG_EXTSZINHERIT) &&
259 	    xfs_extlen_to_rtxmod(sc->mp, value) > 0)
260 		xchk_ino_set_warning(sc, ino);
261 }
262 
263 /*
264  * Validate di_cowextsize hint.
265  *
266  * The rules are documented at xfs_ioctl_setattr_check_cowextsize().
267  * These functions must be kept in sync with each other.
268  */
269 STATIC void
270 xchk_inode_cowextsize(
271 	struct xfs_scrub	*sc,
272 	struct xfs_dinode	*dip,
273 	xfs_ino_t		ino,
274 	uint16_t		mode,
275 	uint16_t		flags,
276 	uint64_t		flags2)
277 {
278 	xfs_failaddr_t		fa;
279 
280 	fa = xfs_inode_validate_cowextsize(sc->mp,
281 			be32_to_cpu(dip->di_cowextsize), mode, flags,
282 			flags2);
283 	if (fa)
284 		xchk_ino_set_corrupt(sc, ino);
285 }
286 
287 /* Make sure the di_flags make sense for the inode. */
288 STATIC void
289 xchk_inode_flags(
290 	struct xfs_scrub	*sc,
291 	struct xfs_dinode	*dip,
292 	xfs_ino_t		ino,
293 	uint16_t		mode,
294 	uint16_t		flags)
295 {
296 	struct xfs_mount	*mp = sc->mp;
297 
298 	/* di_flags are all taken, last bit cannot be used */
299 	if (flags & ~XFS_DIFLAG_ANY)
300 		goto bad;
301 
302 	/* rt flags require rt device */
303 	if ((flags & XFS_DIFLAG_REALTIME) && !mp->m_rtdev_targp)
304 		goto bad;
305 
306 	/* new rt bitmap flag only valid for rbmino */
307 	if ((flags & XFS_DIFLAG_NEWRTBM) && ino != mp->m_sb.sb_rbmino)
308 		goto bad;
309 
310 	/* directory-only flags */
311 	if ((flags & (XFS_DIFLAG_RTINHERIT |
312 		     XFS_DIFLAG_EXTSZINHERIT |
313 		     XFS_DIFLAG_PROJINHERIT |
314 		     XFS_DIFLAG_NOSYMLINKS)) &&
315 	    !S_ISDIR(mode))
316 		goto bad;
317 
318 	/* file-only flags */
319 	if ((flags & (XFS_DIFLAG_REALTIME | FS_XFLAG_EXTSIZE)) &&
320 	    !S_ISREG(mode))
321 		goto bad;
322 
323 	/* filestreams and rt make no sense */
324 	if ((flags & XFS_DIFLAG_FILESTREAM) && (flags & XFS_DIFLAG_REALTIME))
325 		goto bad;
326 
327 	return;
328 bad:
329 	xchk_ino_set_corrupt(sc, ino);
330 }
331 
332 /* Make sure the di_flags2 make sense for the inode. */
333 STATIC void
334 xchk_inode_flags2(
335 	struct xfs_scrub	*sc,
336 	struct xfs_dinode	*dip,
337 	xfs_ino_t		ino,
338 	uint16_t		mode,
339 	uint16_t		flags,
340 	uint64_t		flags2)
341 {
342 	struct xfs_mount	*mp = sc->mp;
343 
344 	/* Unknown di_flags2 could be from a future kernel */
345 	if (flags2 & ~XFS_DIFLAG2_ANY)
346 		xchk_ino_set_warning(sc, ino);
347 
348 	/* reflink flag requires reflink feature */
349 	if ((flags2 & XFS_DIFLAG2_REFLINK) &&
350 	    !xfs_has_reflink(mp))
351 		goto bad;
352 
353 	/* cowextsize flag is checked w.r.t. mode separately */
354 
355 	/* file/dir-only flags */
356 	if ((flags2 & XFS_DIFLAG2_DAX) && !(S_ISREG(mode) || S_ISDIR(mode)))
357 		goto bad;
358 
359 	/* file-only flags */
360 	if ((flags2 & XFS_DIFLAG2_REFLINK) && !S_ISREG(mode))
361 		goto bad;
362 
363 	/* realtime and reflink make no sense, currently */
364 	if ((flags & XFS_DIFLAG_REALTIME) && (flags2 & XFS_DIFLAG2_REFLINK))
365 		goto bad;
366 
367 	/* no bigtime iflag without the bigtime feature */
368 	if (xfs_dinode_has_bigtime(dip) && !xfs_has_bigtime(mp))
369 		goto bad;
370 
371 	/* no large extent counts without the filesystem feature */
372 	if ((flags2 & XFS_DIFLAG2_NREXT64) && !xfs_has_large_extent_counts(mp))
373 		goto bad;
374 
375 	return;
376 bad:
377 	xchk_ino_set_corrupt(sc, ino);
378 }
379 
380 static inline void
381 xchk_dinode_nsec(
382 	struct xfs_scrub	*sc,
383 	xfs_ino_t		ino,
384 	struct xfs_dinode	*dip,
385 	const xfs_timestamp_t	ts)
386 {
387 	struct timespec64	tv;
388 
389 	tv = xfs_inode_from_disk_ts(dip, ts);
390 	if (tv.tv_nsec < 0 || tv.tv_nsec >= NSEC_PER_SEC)
391 		xchk_ino_set_corrupt(sc, ino);
392 }
393 
394 /* Scrub all the ondisk inode fields. */
395 STATIC void
396 xchk_dinode(
397 	struct xfs_scrub	*sc,
398 	struct xfs_dinode	*dip,
399 	xfs_ino_t		ino)
400 {
401 	struct xfs_mount	*mp = sc->mp;
402 	size_t			fork_recs;
403 	unsigned long long	isize;
404 	uint64_t		flags2;
405 	xfs_extnum_t		nextents;
406 	xfs_extnum_t		naextents;
407 	prid_t			prid;
408 	uint16_t		flags;
409 	uint16_t		mode;
410 
411 	flags = be16_to_cpu(dip->di_flags);
412 	if (dip->di_version >= 3)
413 		flags2 = be64_to_cpu(dip->di_flags2);
414 	else
415 		flags2 = 0;
416 
417 	/* di_mode */
418 	mode = be16_to_cpu(dip->di_mode);
419 	switch (mode & S_IFMT) {
420 	case S_IFLNK:
421 	case S_IFREG:
422 	case S_IFDIR:
423 	case S_IFCHR:
424 	case S_IFBLK:
425 	case S_IFIFO:
426 	case S_IFSOCK:
427 		/* mode is recognized */
428 		break;
429 	default:
430 		xchk_ino_set_corrupt(sc, ino);
431 		break;
432 	}
433 
434 	/* v1/v2 fields */
435 	switch (dip->di_version) {
436 	case 1:
437 		/*
438 		 * We autoconvert v1 inodes into v2 inodes on writeout,
439 		 * so just mark this inode for preening.
440 		 */
441 		xchk_ino_set_preen(sc, ino);
442 		prid = 0;
443 		break;
444 	case 2:
445 	case 3:
446 		if (xfs_dinode_is_metadir(dip)) {
447 			if (be16_to_cpu(dip->di_metatype) >= XFS_METAFILE_MAX)
448 				xchk_ino_set_corrupt(sc, ino);
449 		} else {
450 			if (dip->di_metatype != 0)
451 				xchk_ino_set_corrupt(sc, ino);
452 		}
453 
454 		if (dip->di_mode == 0 && sc->ip)
455 			xchk_ino_set_corrupt(sc, ino);
456 
457 		if (dip->di_projid_hi != 0 &&
458 		    !xfs_has_projid32(mp))
459 			xchk_ino_set_corrupt(sc, ino);
460 
461 		prid = be16_to_cpu(dip->di_projid_lo);
462 		break;
463 	default:
464 		xchk_ino_set_corrupt(sc, ino);
465 		return;
466 	}
467 
468 	if (xfs_has_projid32(mp))
469 		prid |= (prid_t)be16_to_cpu(dip->di_projid_hi) << 16;
470 
471 	/*
472 	 * di_uid/di_gid -- -1 isn't invalid, but there's no way that
473 	 * userspace could have created that.
474 	 */
475 	if (dip->di_uid == cpu_to_be32(-1U) ||
476 	    dip->di_gid == cpu_to_be32(-1U))
477 		xchk_ino_set_warning(sc, ino);
478 
479 	/*
480 	 * project id of -1 isn't supposed to be valid, but the kernel didn't
481 	 * always validate that.
482 	 */
483 	if (prid == -1U)
484 		xchk_ino_set_warning(sc, ino);
485 
486 	/* di_format */
487 	switch (dip->di_format) {
488 	case XFS_DINODE_FMT_DEV:
489 		if (!S_ISCHR(mode) && !S_ISBLK(mode) &&
490 		    !S_ISFIFO(mode) && !S_ISSOCK(mode))
491 			xchk_ino_set_corrupt(sc, ino);
492 		break;
493 	case XFS_DINODE_FMT_LOCAL:
494 		if (!S_ISDIR(mode) && !S_ISLNK(mode))
495 			xchk_ino_set_corrupt(sc, ino);
496 		break;
497 	case XFS_DINODE_FMT_EXTENTS:
498 		if (!S_ISREG(mode) && !S_ISDIR(mode) && !S_ISLNK(mode))
499 			xchk_ino_set_corrupt(sc, ino);
500 		break;
501 	case XFS_DINODE_FMT_BTREE:
502 		if (!S_ISREG(mode) && !S_ISDIR(mode))
503 			xchk_ino_set_corrupt(sc, ino);
504 		break;
505 	case XFS_DINODE_FMT_UUID:
506 	default:
507 		xchk_ino_set_corrupt(sc, ino);
508 		break;
509 	}
510 
511 	/* di_[amc]time.nsec */
512 	xchk_dinode_nsec(sc, ino, dip, dip->di_atime);
513 	xchk_dinode_nsec(sc, ino, dip, dip->di_mtime);
514 	xchk_dinode_nsec(sc, ino, dip, dip->di_ctime);
515 
516 	/*
517 	 * di_size.  xfs_dinode_verify checks for things that screw up
518 	 * the VFS such as the upper bit being set and zero-length
519 	 * symlinks/directories, but we can do more here.
520 	 */
521 	isize = be64_to_cpu(dip->di_size);
522 	if (isize & (1ULL << 63))
523 		xchk_ino_set_corrupt(sc, ino);
524 
525 	/* Devices, fifos, and sockets must have zero size */
526 	if (!S_ISDIR(mode) && !S_ISREG(mode) && !S_ISLNK(mode) && isize != 0)
527 		xchk_ino_set_corrupt(sc, ino);
528 
529 	/* Directories can't be larger than the data section size (32G) */
530 	if (S_ISDIR(mode) && (isize == 0 || isize >= XFS_DIR2_SPACE_SIZE))
531 		xchk_ino_set_corrupt(sc, ino);
532 
533 	/* Symlinks can't be larger than SYMLINK_MAXLEN */
534 	if (S_ISLNK(mode) && (isize == 0 || isize >= XFS_SYMLINK_MAXLEN))
535 		xchk_ino_set_corrupt(sc, ino);
536 
537 	/*
538 	 * Warn if the running kernel can't handle the kinds of offsets
539 	 * needed to deal with the file size.  In other words, if the
540 	 * pagecache can't cache all the blocks in this file due to
541 	 * overly large offsets, flag the inode for admin review.
542 	 */
543 	if (isize > mp->m_super->s_maxbytes)
544 		xchk_ino_set_warning(sc, ino);
545 
546 	/* di_nblocks */
547 	if (flags2 & XFS_DIFLAG2_REFLINK) {
548 		; /* nblocks can exceed dblocks */
549 	} else if (flags & XFS_DIFLAG_REALTIME) {
550 		/*
551 		 * nblocks is the sum of data extents (in the rtdev),
552 		 * attr extents (in the datadev), and both forks' bmbt
553 		 * blocks (in the datadev).  This clumsy check is the
554 		 * best we can do without cross-referencing with the
555 		 * inode forks.
556 		 */
557 		if (be64_to_cpu(dip->di_nblocks) >=
558 		    mp->m_sb.sb_dblocks + mp->m_sb.sb_rblocks)
559 			xchk_ino_set_corrupt(sc, ino);
560 	} else {
561 		if (be64_to_cpu(dip->di_nblocks) >= mp->m_sb.sb_dblocks)
562 			xchk_ino_set_corrupt(sc, ino);
563 	}
564 
565 	xchk_inode_flags(sc, dip, ino, mode, flags);
566 
567 	xchk_inode_extsize(sc, dip, ino, mode, flags);
568 
569 	nextents = xfs_dfork_data_extents(dip);
570 	naextents = xfs_dfork_attr_extents(dip);
571 
572 	/* di_nextents */
573 	fork_recs =  XFS_DFORK_DSIZE(dip, mp) / sizeof(struct xfs_bmbt_rec);
574 	switch (dip->di_format) {
575 	case XFS_DINODE_FMT_EXTENTS:
576 		if (nextents > fork_recs)
577 			xchk_ino_set_corrupt(sc, ino);
578 		break;
579 	case XFS_DINODE_FMT_BTREE:
580 		if (nextents <= fork_recs)
581 			xchk_ino_set_corrupt(sc, ino);
582 		break;
583 	default:
584 		if (nextents != 0)
585 			xchk_ino_set_corrupt(sc, ino);
586 		break;
587 	}
588 
589 	/* di_forkoff */
590 	if (XFS_DFORK_BOFF(dip) >= mp->m_sb.sb_inodesize)
591 		xchk_ino_set_corrupt(sc, ino);
592 	if (naextents != 0 && dip->di_forkoff == 0)
593 		xchk_ino_set_corrupt(sc, ino);
594 	if (dip->di_forkoff == 0 && dip->di_aformat != XFS_DINODE_FMT_EXTENTS)
595 		xchk_ino_set_corrupt(sc, ino);
596 
597 	/* di_aformat */
598 	if (dip->di_aformat != XFS_DINODE_FMT_LOCAL &&
599 	    dip->di_aformat != XFS_DINODE_FMT_EXTENTS &&
600 	    dip->di_aformat != XFS_DINODE_FMT_BTREE)
601 		xchk_ino_set_corrupt(sc, ino);
602 
603 	/* di_anextents */
604 	fork_recs =  XFS_DFORK_ASIZE(dip, mp) / sizeof(struct xfs_bmbt_rec);
605 	switch (dip->di_aformat) {
606 	case XFS_DINODE_FMT_EXTENTS:
607 		if (naextents > fork_recs)
608 			xchk_ino_set_corrupt(sc, ino);
609 		break;
610 	case XFS_DINODE_FMT_BTREE:
611 		if (naextents <= fork_recs)
612 			xchk_ino_set_corrupt(sc, ino);
613 		break;
614 	default:
615 		if (naextents != 0)
616 			xchk_ino_set_corrupt(sc, ino);
617 	}
618 
619 	if (dip->di_version >= 3) {
620 		xchk_dinode_nsec(sc, ino, dip, dip->di_crtime);
621 		xchk_inode_flags2(sc, dip, ino, mode, flags, flags2);
622 		xchk_inode_cowextsize(sc, dip, ino, mode, flags,
623 				flags2);
624 	}
625 }
626 
627 /*
628  * Make sure the finobt doesn't think this inode is free.
629  * We don't have to check the inobt ourselves because we got the inode via
630  * IGET_UNTRUSTED, which checks the inobt for us.
631  */
632 static void
633 xchk_inode_xref_finobt(
634 	struct xfs_scrub		*sc,
635 	xfs_ino_t			ino)
636 {
637 	struct xfs_inobt_rec_incore	rec;
638 	xfs_agino_t			agino;
639 	int				has_record;
640 	int				error;
641 
642 	if (!sc->sa.fino_cur || xchk_skip_xref(sc->sm))
643 		return;
644 
645 	agino = XFS_INO_TO_AGINO(sc->mp, ino);
646 
647 	/*
648 	 * Try to get the finobt record.  If we can't get it, then we're
649 	 * in good shape.
650 	 */
651 	error = xfs_inobt_lookup(sc->sa.fino_cur, agino, XFS_LOOKUP_LE,
652 			&has_record);
653 	if (!xchk_should_check_xref(sc, &error, &sc->sa.fino_cur) ||
654 	    !has_record)
655 		return;
656 
657 	error = xfs_inobt_get_rec(sc->sa.fino_cur, &rec, &has_record);
658 	if (!xchk_should_check_xref(sc, &error, &sc->sa.fino_cur) ||
659 	    !has_record)
660 		return;
661 
662 	/*
663 	 * Otherwise, make sure this record either doesn't cover this inode,
664 	 * or that it does but it's marked present.
665 	 */
666 	if (rec.ir_startino > agino ||
667 	    rec.ir_startino + XFS_INODES_PER_CHUNK <= agino)
668 		return;
669 
670 	if (rec.ir_free & XFS_INOBT_MASK(agino - rec.ir_startino))
671 		xchk_btree_xref_set_corrupt(sc, sc->sa.fino_cur, 0);
672 }
673 
674 /* Cross reference the inode fields with the forks. */
675 STATIC void
676 xchk_inode_xref_bmap(
677 	struct xfs_scrub	*sc,
678 	struct xfs_dinode	*dip)
679 {
680 	xfs_extnum_t		nextents;
681 	xfs_filblks_t		count;
682 	xfs_filblks_t		acount;
683 	int			error;
684 
685 	if (xchk_skip_xref(sc->sm))
686 		return;
687 
688 	/* Walk all the extents to check nextents/naextents/nblocks. */
689 	error = xfs_bmap_count_blocks(sc->tp, sc->ip, XFS_DATA_FORK,
690 			&nextents, &count);
691 	if (!xchk_should_check_xref(sc, &error, NULL))
692 		return;
693 	if (nextents < xfs_dfork_data_extents(dip))
694 		xchk_ino_xref_set_corrupt(sc, sc->ip->i_ino);
695 
696 	error = xfs_bmap_count_blocks(sc->tp, sc->ip, XFS_ATTR_FORK,
697 			&nextents, &acount);
698 	if (!xchk_should_check_xref(sc, &error, NULL))
699 		return;
700 	if (nextents != xfs_dfork_attr_extents(dip))
701 		xchk_ino_xref_set_corrupt(sc, sc->ip->i_ino);
702 
703 	/* Check nblocks against the inode. */
704 	if (count + acount != be64_to_cpu(dip->di_nblocks))
705 		xchk_ino_xref_set_corrupt(sc, sc->ip->i_ino);
706 }
707 
708 /* Cross-reference with the other btrees. */
709 STATIC void
710 xchk_inode_xref(
711 	struct xfs_scrub	*sc,
712 	xfs_ino_t		ino,
713 	struct xfs_dinode	*dip)
714 {
715 	xfs_agnumber_t		agno;
716 	xfs_agblock_t		agbno;
717 	int			error;
718 
719 	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
720 		return;
721 
722 	agno = XFS_INO_TO_AGNO(sc->mp, ino);
723 	agbno = XFS_INO_TO_AGBNO(sc->mp, ino);
724 
725 	error = xchk_ag_init_existing(sc, agno, &sc->sa);
726 	if (!xchk_xref_process_error(sc, agno, agbno, &error))
727 		goto out_free;
728 
729 	xchk_xref_is_used_space(sc, agbno, 1);
730 	xchk_inode_xref_finobt(sc, ino);
731 	xchk_xref_is_only_owned_by(sc, agbno, 1, &XFS_RMAP_OINFO_INODES);
732 	xchk_xref_is_not_shared(sc, agbno, 1);
733 	xchk_xref_is_not_cow_staging(sc, agbno, 1);
734 	xchk_inode_xref_bmap(sc, dip);
735 
736 out_free:
737 	xchk_ag_free(sc, &sc->sa);
738 }
739 
740 /*
741  * If the reflink iflag disagrees with a scan for shared data fork extents,
742  * either flag an error (shared extents w/ no flag) or a preen (flag set w/o
743  * any shared extents).  We already checked for reflink iflag set on a non
744  * reflink filesystem.
745  */
746 static void
747 xchk_inode_check_reflink_iflag(
748 	struct xfs_scrub	*sc,
749 	xfs_ino_t		ino)
750 {
751 	struct xfs_mount	*mp = sc->mp;
752 	bool			has_shared;
753 	int			error;
754 
755 	if (!xfs_has_reflink(mp))
756 		return;
757 
758 	error = xfs_reflink_inode_has_shared_extents(sc->tp, sc->ip,
759 			&has_shared);
760 	if (!xchk_xref_process_error(sc, XFS_INO_TO_AGNO(mp, ino),
761 			XFS_INO_TO_AGBNO(mp, ino), &error))
762 		return;
763 	if (xfs_is_reflink_inode(sc->ip) && !has_shared)
764 		xchk_ino_set_preen(sc, ino);
765 	else if (!xfs_is_reflink_inode(sc->ip) && has_shared)
766 		xchk_ino_set_corrupt(sc, ino);
767 }
768 
769 /*
770  * If this inode has zero link count, it must be on the unlinked list.  If
771  * it has nonzero link count, it must not be on the unlinked list.
772  */
773 STATIC void
774 xchk_inode_check_unlinked(
775 	struct xfs_scrub	*sc)
776 {
777 	if (VFS_I(sc->ip)->i_nlink == 0) {
778 		if (!xfs_inode_on_unlinked_list(sc->ip))
779 			xchk_ino_set_corrupt(sc, sc->ip->i_ino);
780 	} else {
781 		if (xfs_inode_on_unlinked_list(sc->ip))
782 			xchk_ino_set_corrupt(sc, sc->ip->i_ino);
783 	}
784 }
785 
786 /* Scrub an inode. */
787 int
788 xchk_inode(
789 	struct xfs_scrub	*sc)
790 {
791 	struct xfs_dinode	di;
792 	int			error = 0;
793 
794 	/*
795 	 * If sc->ip is NULL, that means that the setup function called
796 	 * xfs_iget to look up the inode.  xfs_iget returned a EFSCORRUPTED
797 	 * and a NULL inode, so flag the corruption error and return.
798 	 */
799 	if (!sc->ip) {
800 		xchk_ino_set_corrupt(sc, sc->sm->sm_ino);
801 		return 0;
802 	}
803 
804 	/* Scrub the inode core. */
805 	xfs_inode_to_disk(sc->ip, &di, 0);
806 	xchk_dinode(sc, &di, sc->ip->i_ino);
807 	if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
808 		goto out;
809 
810 	/*
811 	 * Look for discrepancies between file's data blocks and the reflink
812 	 * iflag.  We already checked the iflag against the file mode when
813 	 * we scrubbed the dinode.
814 	 */
815 	if (S_ISREG(VFS_I(sc->ip)->i_mode))
816 		xchk_inode_check_reflink_iflag(sc, sc->ip->i_ino);
817 
818 	xchk_inode_check_unlinked(sc);
819 
820 	xchk_inode_xref(sc, sc->ip->i_ino, &di);
821 out:
822 	return error;
823 }
824