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_log_format.h"
13 #include "xfs_trans.h"
14 #include "xfs_inode.h"
15 #include "xfs_icache.h"
16 #include "xfs_dir2.h"
17 #include "xfs_dir2_priv.h"
18 #include "xfs_health.h"
19 #include "xfs_attr.h"
20 #include "xfs_parent.h"
21 #include "scrub/scrub.h"
22 #include "scrub/common.h"
23 #include "scrub/dabtree.h"
24 #include "scrub/readdir.h"
25 #include "scrub/health.h"
26 #include "scrub/repair.h"
27 #include "scrub/trace.h"
28 #include "scrub/xfile.h"
29 #include "scrub/xfarray.h"
30 #include "scrub/xfblob.h"
31
32 /* Set us up to scrub directories. */
33 int
34 xchk_setup_directory(
35 struct xfs_scrub *sc)
36 {
37 int error;
38
39 if (xchk_could_repair(sc)) {
40 error = xrep_setup_directory(sc);
41 if (error)
42 return error;
43 }
44
45 return xchk_setup_inode_contents(sc, 0);
46 }
47
48 /* Directories */
49
50 /* Deferred directory entry that we saved for later. */
51 struct xchk_dirent {
52 /* Cookie for retrieval of the dirent name. */
53 xfblob_cookie name_cookie;
54
55 /* Child inode number. */
56 xfs_ino_t ino;
57
58 /* Length of the pptr name. */
59 uint8_t namelen;
60 };
61
62 struct xchk_dir {
63 struct xfs_scrub *sc;
64
65 /* information for parent pointer validation. */
66 struct xfs_parent_rec pptr_rec;
67 struct xfs_da_args pptr_args;
68
69 /* Fixed-size array of xchk_dirent structures. */
70 struct xfarray *dir_entries;
71
72 /* Blobs containing dirent names. */
73 struct xfblob *dir_names;
74
75 /* If we've cycled the ILOCK, we must revalidate deferred dirents. */
76 bool need_revalidate;
77
78 /* Name buffer for dirent revalidation. */
79 struct xfs_name xname;
80 uint8_t namebuf[MAXNAMELEN];
81 };
82
83 /* Scrub a directory entry. */
84
85 /* Check that an inode's mode matches a given XFS_DIR3_FT_* type. */
86 STATIC void
87 xchk_dir_check_ftype(
88 struct xfs_scrub *sc,
89 xfs_fileoff_t offset,
90 struct xfs_inode *ip,
91 int ftype)
92 {
93 struct xfs_mount *mp = sc->mp;
94
95 if (!xfs_has_ftype(mp)) {
96 if (ftype != XFS_DIR3_FT_UNKNOWN && ftype != XFS_DIR3_FT_DIR)
97 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
98 return;
99 }
100
101 if (xfs_mode_to_ftype(VFS_I(ip)->i_mode) != ftype)
102 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
103 }
104
105 /*
106 * Try to lock a child file for checking parent pointers. Returns the inode
107 * flags for the locks we now hold, or zero if we failed.
108 */
109 STATIC unsigned int
110 xchk_dir_lock_child(
111 struct xfs_scrub *sc,
112 struct xfs_inode *ip)
113 {
114 if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED))
115 return 0;
116
117 if (!xfs_ilock_nowait(ip, XFS_ILOCK_SHARED)) {
118 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
119 return 0;
120 }
121
122 if (!xfs_inode_has_attr_fork(ip) || !xfs_need_iread_extents(&ip->i_af))
123 return XFS_IOLOCK_SHARED | XFS_ILOCK_SHARED;
124
125 xfs_iunlock(ip, XFS_ILOCK_SHARED);
126
127 if (!xfs_ilock_nowait(ip, XFS_ILOCK_EXCL)) {
128 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
129 return 0;
130 }
131
132 return XFS_IOLOCK_SHARED | XFS_ILOCK_EXCL;
133 }
134
135 /* Check the backwards link (parent pointer) associated with this dirent. */
136 STATIC int
137 xchk_dir_parent_pointer(
138 struct xchk_dir *sd,
139 const struct xfs_name *name,
140 struct xfs_inode *ip)
141 {
142 struct xfs_scrub *sc = sd->sc;
143 int error;
144
145 xfs_inode_to_parent_rec(&sd->pptr_rec, sc->ip);
146 error = xfs_parent_lookup(sc->tp, ip, name, &sd->pptr_rec,
147 &sd->pptr_args);
148 if (error == -ENOATTR)
149 xchk_fblock_xref_set_corrupt(sc, XFS_DATA_FORK, 0);
150
151 return 0;
152 }
153
154 /* Look for a parent pointer matching this dirent, if the child isn't busy. */
155 STATIC int
156 xchk_dir_check_pptr_fast(
157 struct xchk_dir *sd,
158 xfs_dir2_dataptr_t dapos,
159 const struct xfs_name *name,
160 struct xfs_inode *ip)
161 {
162 struct xfs_scrub *sc = sd->sc;
163 unsigned int lockmode;
164 int error;
165
166 /* dot and dotdot entries do not have parent pointers */
167 if (xfs_dir2_samename(name, &xfs_name_dot) ||
168 xfs_dir2_samename(name, &xfs_name_dotdot))
169 return 0;
170
171 /* No self-referential non-dot or dotdot dirents. */
172 if (ip == sc->ip) {
173 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
174 return -ECANCELED;
175 }
176
177 /* Try to lock the inode. */
178 lockmode = xchk_dir_lock_child(sc, ip);
179 if (!lockmode) {
180 struct xchk_dirent save_de = {
181 .namelen = name->len,
182 .ino = ip->i_ino,
183 };
184
185 /* Couldn't lock the inode, so save the dirent for later. */
186 trace_xchk_dir_defer(sc->ip, name, ip->i_ino);
187
188 error = xfblob_storename(sd->dir_names, &save_de.name_cookie,
189 name);
190 if (!xchk_fblock_xref_process_error(sc, XFS_DATA_FORK, 0,
191 &error))
192 return error;
193
194 error = xfarray_append(sd->dir_entries, &save_de);
195 if (!xchk_fblock_xref_process_error(sc, XFS_DATA_FORK, 0,
196 &error))
197 return error;
198
199 return 0;
200 }
201
202 error = xchk_dir_parent_pointer(sd, name, ip);
203 xfs_iunlock(ip, lockmode);
204 return error;
205 }
206
207 /*
208 * Scrub a single directory entry.
209 *
210 * Check the inode number to make sure it's sane, then we check that we can
211 * look up this filename. Finally, we check the ftype.
212 */
213 STATIC int
214 xchk_dir_actor(
215 struct xfs_scrub *sc,
216 struct xfs_inode *dp,
217 xfs_dir2_dataptr_t dapos,
218 const struct xfs_name *name,
219 xfs_ino_t ino,
220 void *priv)
221 {
222 struct xfs_mount *mp = dp->i_mount;
223 struct xfs_inode *ip;
224 struct xchk_dir *sd = priv;
225 xfs_ino_t lookup_ino;
226 xfs_dablk_t offset;
227 int error = 0;
228
229 offset = xfs_dir2_db_to_da(mp->m_dir_geo,
230 xfs_dir2_dataptr_to_db(mp->m_dir_geo, dapos));
231
232 if (xchk_should_terminate(sc, &error))
233 return error;
234
235 /* Does this inode number make sense? */
236 if (!xfs_verify_dir_ino(mp, ino)) {
237 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
238 return -ECANCELED;
239 }
240
241 /* Does this name make sense? */
242 if (!xfs_dir2_namecheck(name->name, name->len)) {
243 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
244 return -ECANCELED;
245 }
246
247 if (xfs_dir2_samename(name, &xfs_name_dot)) {
248 /* If this is "." then check that the inum matches the dir. */
249 if (ino != dp->i_ino)
250 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
251 } else if (xfs_dir2_samename(name, &xfs_name_dotdot)) {
252 /*
253 * If this is ".." in the root inode, check that the inum
254 * matches this dir.
255 */
256 if (dp->i_ino == mp->m_sb.sb_rootino && ino != dp->i_ino)
257 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
258 }
259
260 /* Verify that we can look up this name by hash. */
261 error = xchk_dir_lookup(sc, dp, name, &lookup_ino);
262 /* ENOENT means the hash lookup failed and the dir is corrupt */
263 if (error == -ENOENT)
264 error = -EFSCORRUPTED;
265 if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, offset, &error))
266 goto out;
267 if (lookup_ino != ino) {
268 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, offset);
269 return -ECANCELED;
270 }
271
272 /*
273 * Grab the inode pointed to by the dirent. We release the inode
274 * before we cancel the scrub transaction.
275 *
276 * If _iget returns -EINVAL or -ENOENT then the child inode number is
277 * garbage and the directory is corrupt. If the _iget returns
278 * -EFSCORRUPTED or -EFSBADCRC then the child is corrupt which is a
279 * cross referencing error. Any other error is an operational error.
280 */
281 error = xchk_iget(sc, ino, &ip);
282 if (error == -EINVAL || error == -ENOENT) {
283 error = -EFSCORRUPTED;
284 xchk_fblock_process_error(sc, XFS_DATA_FORK, 0, &error);
285 goto out;
286 }
287 if (!xchk_fblock_xref_process_error(sc, XFS_DATA_FORK, offset, &error))
288 goto out;
289
290 xchk_dir_check_ftype(sc, offset, ip, name->type);
291
292 if (xfs_has_parent(mp)) {
293 error = xchk_dir_check_pptr_fast(sd, dapos, name, ip);
294 if (error)
295 goto out_rele;
296 }
297
298 out_rele:
299 xchk_irele(sc, ip);
300 out:
301 if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
302 return -ECANCELED;
303 return error;
304 }
305
306 /* Scrub a directory btree record. */
307 STATIC int
308 xchk_dir_rec(
309 struct xchk_da_btree *ds,
310 int level)
311 {
312 struct xfs_name dname = { };
313 struct xfs_da_state_blk *blk = &ds->state->path.blk[level];
314 struct xfs_mount *mp = ds->state->mp;
315 struct xfs_inode *dp = ds->dargs.dp;
316 struct xfs_da_geometry *geo = mp->m_dir_geo;
317 struct xfs_dir2_data_entry *dent;
318 struct xfs_buf *bp;
319 struct xfs_dir2_leaf_entry *ent;
320 unsigned int end;
321 unsigned int iter_off;
322 xfs_ino_t ino;
323 xfs_dablk_t rec_bno;
324 xfs_dir2_db_t db;
325 xfs_dir2_data_aoff_t off;
326 xfs_dir2_dataptr_t ptr;
327 xfs_dahash_t calc_hash;
328 xfs_dahash_t hash;
329 struct xfs_dir3_icleaf_hdr hdr;
330 unsigned int tag;
331 int error;
332
333 ASSERT(blk->magic == XFS_DIR2_LEAF1_MAGIC ||
334 blk->magic == XFS_DIR2_LEAFN_MAGIC);
335
336 xfs_dir2_leaf_hdr_from_disk(mp, &hdr, blk->bp->b_addr);
337 ent = hdr.ents + blk->index;
338
339 /* Check the hash of the entry. */
340 error = xchk_da_btree_hash(ds, level, &ent->hashval);
341 if (error)
342 goto out;
343
344 /* Valid hash pointer? */
345 ptr = be32_to_cpu(ent->address);
346 if (ptr == 0)
347 return 0;
348
349 /* Find the directory entry's location. */
350 db = xfs_dir2_dataptr_to_db(geo, ptr);
351 off = xfs_dir2_dataptr_to_off(geo, ptr);
352 rec_bno = xfs_dir2_db_to_da(geo, db);
353
354 if (rec_bno >= geo->leafblk) {
355 xchk_da_set_corrupt(ds, level);
356 goto out;
357 }
358 error = xfs_dir3_data_read(ds->dargs.trans, dp, ds->dargs.owner,
359 rec_bno, XFS_DABUF_MAP_HOLE_OK, &bp);
360 if (!xchk_fblock_process_error(ds->sc, XFS_DATA_FORK, rec_bno,
361 &error))
362 goto out;
363 if (!bp) {
364 xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
365 goto out;
366 }
367 xchk_buffer_recheck(ds->sc, bp);
368
369 if (ds->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
370 goto out_relse;
371
372 dent = bp->b_addr + off;
373
374 /* Make sure we got a real directory entry. */
375 iter_off = geo->data_entry_offset;
376 end = xfs_dir3_data_end_offset(geo, bp->b_addr);
377 if (!end) {
378 xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
379 goto out_relse;
380 }
381 for (;;) {
382 struct xfs_dir2_data_entry *dep = bp->b_addr + iter_off;
383 struct xfs_dir2_data_unused *dup = bp->b_addr + iter_off;
384
385 if (iter_off >= end) {
386 xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
387 goto out_relse;
388 }
389
390 if (be16_to_cpu(dup->freetag) == XFS_DIR2_DATA_FREE_TAG) {
391 iter_off += be16_to_cpu(dup->length);
392 continue;
393 }
394 if (dep == dent)
395 break;
396 iter_off += xfs_dir2_data_entsize(mp, dep->namelen);
397 }
398
399 /* Retrieve the entry, sanity check it, and compare hashes. */
400 ino = be64_to_cpu(dent->inumber);
401 hash = be32_to_cpu(ent->hashval);
402 tag = be16_to_cpup(xfs_dir2_data_entry_tag_p(mp, dent));
403 if (!xfs_verify_dir_ino(mp, ino) || tag != off)
404 xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
405 if (dent->namelen == 0) {
406 xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
407 goto out_relse;
408 }
409
410 /* Does the directory hash match? */
411 dname.name = dent->name;
412 dname.len = dent->namelen;
413 calc_hash = xfs_dir2_hashname(mp, &dname);
414 if (calc_hash != hash)
415 xchk_fblock_set_corrupt(ds->sc, XFS_DATA_FORK, rec_bno);
416
417 out_relse:
418 xfs_trans_brelse(ds->dargs.trans, bp);
419 out:
420 return error;
421 }
422
423 /*
424 * Is this unused entry either in the bestfree or smaller than all of
425 * them? We've already checked that the bestfrees are sorted longest to
426 * shortest, and that there aren't any bogus entries.
427 */
428 STATIC void
429 xchk_directory_check_free_entry(
430 struct xfs_scrub *sc,
431 xfs_dablk_t lblk,
432 struct xfs_dir2_data_free *bf,
433 struct xfs_dir2_data_unused *dup)
434 {
435 struct xfs_dir2_data_free *dfp;
436 unsigned int dup_length;
437
438 dup_length = be16_to_cpu(dup->length);
439
440 /* Unused entry is shorter than any of the bestfrees */
441 if (dup_length < be16_to_cpu(bf[XFS_DIR2_DATA_FD_COUNT - 1].length))
442 return;
443
444 for (dfp = &bf[XFS_DIR2_DATA_FD_COUNT - 1]; dfp >= bf; dfp--)
445 if (dup_length == be16_to_cpu(dfp->length))
446 return;
447
448 /* Unused entry should be in the bestfrees but wasn't found. */
449 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
450 }
451
452 /* Check free space info in a directory data block. */
453 STATIC int
454 xchk_directory_data_bestfree(
455 struct xfs_scrub *sc,
456 xfs_dablk_t lblk,
457 bool is_block)
458 {
459 struct xfs_dir2_data_unused *dup;
460 struct xfs_dir2_data_free *dfp;
461 struct xfs_buf *bp;
462 struct xfs_dir2_data_free *bf;
463 struct xfs_mount *mp = sc->mp;
464 u16 tag;
465 unsigned int nr_bestfrees = 0;
466 unsigned int nr_frees = 0;
467 unsigned int smallest_bestfree;
468 int newlen;
469 unsigned int offset;
470 unsigned int end;
471 int error;
472
473 if (is_block) {
474 /* dir block format */
475 if (lblk != XFS_B_TO_FSBT(mp, XFS_DIR2_DATA_OFFSET))
476 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
477 error = xfs_dir3_block_read(sc->tp, sc->ip, sc->ip->i_ino, &bp);
478 } else {
479 /* dir data format */
480 error = xfs_dir3_data_read(sc->tp, sc->ip, sc->ip->i_ino, lblk,
481 0, &bp);
482 }
483 if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
484 goto out;
485 xchk_buffer_recheck(sc, bp);
486
487 /* XXX: Check xfs_dir3_data_hdr.pad is zero once we start setting it. */
488
489 if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
490 goto out_buf;
491
492 /* Do the bestfrees correspond to actual free space? */
493 bf = xfs_dir2_data_bestfree_p(mp, bp->b_addr);
494 smallest_bestfree = UINT_MAX;
495 for (dfp = &bf[0]; dfp < &bf[XFS_DIR2_DATA_FD_COUNT]; dfp++) {
496 offset = be16_to_cpu(dfp->offset);
497 if (offset == 0)
498 continue;
499 if (offset >= mp->m_dir_geo->blksize) {
500 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
501 goto out_buf;
502 }
503 dup = bp->b_addr + offset;
504 tag = be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup));
505
506 /* bestfree doesn't match the entry it points at? */
507 if (dup->freetag != cpu_to_be16(XFS_DIR2_DATA_FREE_TAG) ||
508 be16_to_cpu(dup->length) != be16_to_cpu(dfp->length) ||
509 tag != offset) {
510 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
511 goto out_buf;
512 }
513
514 /* bestfree records should be ordered largest to smallest */
515 if (smallest_bestfree < be16_to_cpu(dfp->length)) {
516 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
517 goto out_buf;
518 }
519
520 smallest_bestfree = be16_to_cpu(dfp->length);
521 nr_bestfrees++;
522 }
523
524 /* Make sure the bestfrees are actually the best free spaces. */
525 offset = mp->m_dir_geo->data_entry_offset;
526 end = xfs_dir3_data_end_offset(mp->m_dir_geo, bp->b_addr);
527
528 /* Iterate the entries, stopping when we hit or go past the end. */
529 while (offset < end) {
530 dup = bp->b_addr + offset;
531
532 /* Skip real entries */
533 if (dup->freetag != cpu_to_be16(XFS_DIR2_DATA_FREE_TAG)) {
534 struct xfs_dir2_data_entry *dep = bp->b_addr + offset;
535
536 newlen = xfs_dir2_data_entsize(mp, dep->namelen);
537 if (newlen <= 0) {
538 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK,
539 lblk);
540 goto out_buf;
541 }
542 offset += newlen;
543 continue;
544 }
545
546 /* Spot check this free entry */
547 tag = be16_to_cpu(*xfs_dir2_data_unused_tag_p(dup));
548 if (tag != offset) {
549 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
550 goto out_buf;
551 }
552
553 /*
554 * Either this entry is a bestfree or it's smaller than
555 * any of the bestfrees.
556 */
557 xchk_directory_check_free_entry(sc, lblk, bf, dup);
558 if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
559 goto out_buf;
560
561 /* Move on. */
562 newlen = be16_to_cpu(dup->length);
563 if (newlen <= 0) {
564 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
565 goto out_buf;
566 }
567 offset += newlen;
568 if (offset <= end)
569 nr_frees++;
570 }
571
572 /* We're required to fill all the space. */
573 if (offset != end)
574 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
575
576 /* Did we see at least as many free slots as there are bestfrees? */
577 if (nr_frees < nr_bestfrees)
578 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
579 out_buf:
580 xfs_trans_brelse(sc->tp, bp);
581 out:
582 return error;
583 }
584
585 /*
586 * Does the free space length in the free space index block ($len) match
587 * the longest length in the directory data block's bestfree array?
588 * Assume that we've already checked that the data block's bestfree
589 * array is in order.
590 */
591 STATIC void
592 xchk_directory_check_freesp(
593 struct xfs_scrub *sc,
594 xfs_dablk_t lblk,
595 struct xfs_buf *dbp,
596 unsigned int len)
597 {
598 struct xfs_dir2_data_free *dfp;
599
600 dfp = xfs_dir2_data_bestfree_p(sc->mp, dbp->b_addr);
601
602 if (len != be16_to_cpu(dfp->length))
603 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
604
605 if (len > 0 && be16_to_cpu(dfp->offset) == 0)
606 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
607 }
608
609 /* Check free space info in a directory leaf1 block. */
610 STATIC int
611 xchk_directory_leaf1_bestfree(
612 struct xfs_scrub *sc,
613 struct xfs_da_args *args,
614 xfs_dir2_db_t last_data_db,
615 xfs_dablk_t lblk)
616 {
617 struct xfs_dir3_icleaf_hdr leafhdr;
618 struct xfs_dir2_leaf_tail *ltp;
619 struct xfs_dir2_leaf *leaf;
620 struct xfs_buf *dbp;
621 struct xfs_buf *bp;
622 struct xfs_da_geometry *geo = sc->mp->m_dir_geo;
623 __be16 *bestp;
624 __u16 best;
625 __u32 hash;
626 __u32 lasthash = 0;
627 __u32 bestcount;
628 unsigned int stale = 0;
629 int i;
630 int error;
631
632 /* Read the free space block. */
633 error = xfs_dir3_leaf_read(sc->tp, sc->ip, sc->ip->i_ino, lblk, &bp);
634 if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
635 return error;
636 xchk_buffer_recheck(sc, bp);
637
638 leaf = bp->b_addr;
639 xfs_dir2_leaf_hdr_from_disk(sc->ip->i_mount, &leafhdr, leaf);
640 ltp = xfs_dir2_leaf_tail_p(geo, leaf);
641 bestcount = be32_to_cpu(ltp->bestcount);
642 bestp = xfs_dir2_leaf_bests_p(ltp);
643
644 if (xfs_has_crc(sc->mp)) {
645 struct xfs_dir3_leaf_hdr *hdr3 = bp->b_addr;
646
647 if (hdr3->pad != cpu_to_be32(0))
648 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
649 }
650
651 /*
652 * There must be enough bestfree slots to cover all the directory data
653 * blocks that we scanned. It is possible for there to be a hole
654 * between the last data block and i_disk_size. This seems like an
655 * oversight to the scrub author, but as we have been writing out
656 * directories like this (and xfs_repair doesn't mind them) for years,
657 * that's what we have to check.
658 */
659 if (bestcount != last_data_db + 1) {
660 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
661 goto out;
662 }
663
664 /* Is the leaf count even remotely sane? */
665 if (leafhdr.count > geo->leaf_max_ents) {
666 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
667 goto out;
668 }
669
670 /* Leaves and bests don't overlap in leaf format. */
671 if ((char *)&leafhdr.ents[leafhdr.count] > (char *)bestp) {
672 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
673 goto out;
674 }
675
676 /* Check hash value order, count stale entries. */
677 for (i = 0; i < leafhdr.count; i++) {
678 hash = be32_to_cpu(leafhdr.ents[i].hashval);
679 if (i > 0 && lasthash > hash)
680 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
681 lasthash = hash;
682 if (leafhdr.ents[i].address ==
683 cpu_to_be32(XFS_DIR2_NULL_DATAPTR))
684 stale++;
685 }
686 if (leafhdr.stale != stale)
687 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
688 if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
689 goto out;
690
691 /* Check all the bestfree entries. */
692 for (i = 0; i < bestcount; i++, bestp++) {
693 best = be16_to_cpu(*bestp);
694 error = xfs_dir3_data_read(sc->tp, sc->ip, args->owner,
695 xfs_dir2_db_to_da(args->geo, i),
696 XFS_DABUF_MAP_HOLE_OK, &dbp);
697 if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk,
698 &error))
699 break;
700
701 if (!dbp) {
702 if (best != NULLDATAOFF) {
703 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK,
704 lblk);
705 break;
706 }
707 continue;
708 }
709
710 if (best == NULLDATAOFF)
711 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
712 else
713 xchk_directory_check_freesp(sc, lblk, dbp, best);
714 xfs_trans_brelse(sc->tp, dbp);
715 if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
716 break;
717 }
718 out:
719 xfs_trans_brelse(sc->tp, bp);
720 return error;
721 }
722
723 /* Check free space info in a directory freespace block. */
724 STATIC int
725 xchk_directory_free_bestfree(
726 struct xfs_scrub *sc,
727 struct xfs_da_args *args,
728 xfs_dablk_t lblk)
729 {
730 struct xfs_dir3_icfree_hdr freehdr;
731 struct xfs_buf *dbp;
732 struct xfs_buf *bp;
733 __u16 best;
734 unsigned int stale = 0;
735 int i;
736 int error;
737
738 /* Read the free space block */
739 error = xfs_dir2_free_read(sc->tp, sc->ip, sc->ip->i_ino, lblk, &bp);
740 if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
741 return error;
742 xchk_buffer_recheck(sc, bp);
743
744 if (xfs_has_crc(sc->mp)) {
745 struct xfs_dir3_free_hdr *hdr3 = bp->b_addr;
746
747 if (hdr3->pad != cpu_to_be32(0))
748 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
749 }
750
751 /* Check all the entries. */
752 xfs_dir2_free_hdr_from_disk(sc->ip->i_mount, &freehdr, bp->b_addr);
753 for (i = 0; i < freehdr.nvalid; i++) {
754 best = be16_to_cpu(freehdr.bests[i]);
755 if (best == NULLDATAOFF) {
756 stale++;
757 continue;
758 }
759 error = xfs_dir3_data_read(sc->tp, sc->ip, args->owner,
760 (freehdr.firstdb + i) * args->geo->fsbcount,
761 0, &dbp);
762 if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk,
763 &error))
764 goto out;
765 xchk_directory_check_freesp(sc, lblk, dbp, best);
766 xfs_trans_brelse(sc->tp, dbp);
767 }
768
769 if (freehdr.nused + stale != freehdr.nvalid)
770 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
771 out:
772 xfs_trans_brelse(sc->tp, bp);
773 return error;
774 }
775
776 /* Check free space information in directories. */
777 STATIC int
778 xchk_directory_blocks(
779 struct xfs_scrub *sc)
780 {
781 struct xfs_bmbt_irec got;
782 struct xfs_da_args args = {
783 .dp = sc->ip,
784 .whichfork = XFS_DATA_FORK,
785 .geo = sc->mp->m_dir_geo,
786 .trans = sc->tp,
787 .owner = sc->ip->i_ino,
788 };
789 struct xfs_ifork *ifp = xfs_ifork_ptr(sc->ip, XFS_DATA_FORK);
790 struct xfs_mount *mp = sc->mp;
791 xfs_fileoff_t leaf_lblk;
792 xfs_fileoff_t free_lblk;
793 xfs_fileoff_t lblk;
794 struct xfs_iext_cursor icur;
795 xfs_dablk_t dabno;
796 xfs_dir2_db_t last_data_db = 0;
797 bool found;
798 bool is_block = false;
799 int error;
800
801 /* Ignore local format directories. */
802 if (ifp->if_format != XFS_DINODE_FMT_EXTENTS &&
803 ifp->if_format != XFS_DINODE_FMT_BTREE)
804 return 0;
805
806 lblk = XFS_B_TO_FSB(mp, XFS_DIR2_DATA_OFFSET);
807 leaf_lblk = XFS_B_TO_FSB(mp, XFS_DIR2_LEAF_OFFSET);
808 free_lblk = XFS_B_TO_FSB(mp, XFS_DIR2_FREE_OFFSET);
809
810 /* Is this a block dir? */
811 if (xfs_dir2_format(&args, &error) == XFS_DIR2_FMT_BLOCK)
812 is_block = true;
813 if (!xchk_fblock_process_error(sc, XFS_DATA_FORK, lblk, &error))
814 goto out;
815
816 /* Iterate all the data extents in the directory... */
817 found = xfs_iext_lookup_extent(sc->ip, ifp, lblk, &icur, &got);
818 while (found && !(sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)) {
819 /* No more data blocks... */
820 if (got.br_startoff >= leaf_lblk)
821 break;
822
823 /*
824 * Check each data block's bestfree data.
825 *
826 * Iterate all the fsbcount-aligned block offsets in
827 * this directory. The directory block reading code is
828 * smart enough to do its own bmap lookups to handle
829 * discontiguous directory blocks. When we're done
830 * with the extent record, re-query the bmap at the
831 * next fsbcount-aligned offset to avoid redundant
832 * block checks.
833 */
834 for (lblk = roundup((xfs_dablk_t)got.br_startoff,
835 args.geo->fsbcount);
836 lblk < got.br_startoff + got.br_blockcount;
837 lblk += args.geo->fsbcount) {
838 last_data_db = xfs_dir2_da_to_db(args.geo, lblk);
839 error = xchk_directory_data_bestfree(sc, lblk,
840 is_block);
841 if (error)
842 goto out;
843 }
844 dabno = got.br_startoff + got.br_blockcount;
845 lblk = roundup(dabno, args.geo->fsbcount);
846 found = xfs_iext_lookup_extent(sc->ip, ifp, lblk, &icur, &got);
847 }
848
849 if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
850 goto out;
851
852 /* Look for a leaf1 block, which has free info. */
853 if (xfs_iext_lookup_extent(sc->ip, ifp, leaf_lblk, &icur, &got) &&
854 got.br_startoff == leaf_lblk &&
855 got.br_blockcount == args.geo->fsbcount &&
856 !xfs_iext_next_extent(ifp, &icur, &got)) {
857 if (is_block) {
858 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
859 goto out;
860 }
861 error = xchk_directory_leaf1_bestfree(sc, &args, last_data_db,
862 leaf_lblk);
863 if (error)
864 goto out;
865 }
866
867 if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
868 goto out;
869
870 /* Scan for free blocks */
871 lblk = free_lblk;
872 found = xfs_iext_lookup_extent(sc->ip, ifp, lblk, &icur, &got);
873 while (found && !(sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)) {
874 /*
875 * Dirs can't have blocks mapped above 2^32.
876 * Single-block dirs shouldn't even be here.
877 */
878 lblk = got.br_startoff;
879 if (lblk & ~0xFFFFFFFFULL) {
880 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
881 goto out;
882 }
883 if (is_block) {
884 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, lblk);
885 goto out;
886 }
887
888 /*
889 * Check each dir free block's bestfree data.
890 *
891 * Iterate all the fsbcount-aligned block offsets in
892 * this directory. The directory block reading code is
893 * smart enough to do its own bmap lookups to handle
894 * discontiguous directory blocks. When we're done
895 * with the extent record, re-query the bmap at the
896 * next fsbcount-aligned offset to avoid redundant
897 * block checks.
898 */
899 for (lblk = roundup((xfs_dablk_t)got.br_startoff,
900 args.geo->fsbcount);
901 lblk < got.br_startoff + got.br_blockcount;
902 lblk += args.geo->fsbcount) {
903 error = xchk_directory_free_bestfree(sc, &args,
904 lblk);
905 if (error)
906 goto out;
907 }
908 dabno = got.br_startoff + got.br_blockcount;
909 lblk = roundup(dabno, args.geo->fsbcount);
910 found = xfs_iext_lookup_extent(sc->ip, ifp, lblk, &icur, &got);
911 }
912 out:
913 return error;
914 }
915
916 /*
917 * Revalidate a dirent that we collected in the past but couldn't check because
918 * of lock contention. Returns 0 if the dirent is still valid, -ENOENT if it
919 * has gone away on us, or a negative errno.
920 */
921 STATIC int
922 xchk_dir_revalidate_dirent(
923 struct xchk_dir *sd,
924 const struct xfs_name *xname,
925 xfs_ino_t ino)
926 {
927 struct xfs_scrub *sc = sd->sc;
928 xfs_ino_t child_ino;
929 int error;
930
931 /*
932 * Look up the directory entry. If we get -ENOENT, the directory entry
933 * went away and there's nothing to revalidate. Return any other
934 * error.
935 */
936 error = xchk_dir_lookup(sc, sc->ip, xname, &child_ino);
937 if (error)
938 return error;
939
940 /* The inode number changed, nothing to revalidate. */
941 if (ino != child_ino)
942 return -ENOENT;
943
944 return 0;
945 }
946
947 /*
948 * Check a directory entry's parent pointers the slow way, which means we cycle
949 * locks a bunch and put up with revalidation until we get it done.
950 */
951 STATIC int
952 xchk_dir_slow_dirent(
953 struct xchk_dir *sd,
954 struct xchk_dirent *dirent,
955 const struct xfs_name *xname)
956 {
957 struct xfs_scrub *sc = sd->sc;
958 struct xfs_inode *ip;
959 unsigned int lockmode;
960 int error;
961
962 /* Check that the deferred dirent still exists. */
963 if (sd->need_revalidate) {
964 error = xchk_dir_revalidate_dirent(sd, xname, dirent->ino);
965 if (error == -ENOENT)
966 return 0;
967 if (!xchk_fblock_xref_process_error(sc, XFS_DATA_FORK, 0,
968 &error))
969 return error;
970 }
971
972 error = xchk_iget(sc, dirent->ino, &ip);
973 if (error == -EINVAL || error == -ENOENT) {
974 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
975 return 0;
976 }
977 if (!xchk_fblock_xref_process_error(sc, XFS_DATA_FORK, 0, &error))
978 return error;
979
980 /*
981 * If we can grab both IOLOCK and ILOCK of the alleged child, we can
982 * proceed with the validation.
983 */
984 lockmode = xchk_dir_lock_child(sc, ip);
985 if (lockmode) {
986 trace_xchk_dir_slowpath(sc->ip, xname, ip->i_ino);
987 goto check_pptr;
988 }
989
990 /*
991 * We couldn't lock the child file. Drop all the locks and try to
992 * get them again, one at a time.
993 */
994 xchk_iunlock(sc, sc->ilock_flags);
995 sd->need_revalidate = true;
996
997 trace_xchk_dir_ultraslowpath(sc->ip, xname, ip->i_ino);
998
999 error = xchk_dir_trylock_for_pptrs(sc, ip, &lockmode);
1000 if (error)
1001 goto out_rele;
1002
1003 /* Revalidate, since we just cycled the locks. */
1004 error = xchk_dir_revalidate_dirent(sd, xname, dirent->ino);
1005 if (error == -ENOENT) {
1006 error = 0;
1007 goto out_unlock;
1008 }
1009 if (!xchk_fblock_xref_process_error(sc, XFS_DATA_FORK, 0, &error))
1010 goto out_unlock;
1011
1012 check_pptr:
1013 error = xchk_dir_parent_pointer(sd, xname, ip);
1014 out_unlock:
1015 xfs_iunlock(ip, lockmode);
1016 out_rele:
1017 xchk_irele(sc, ip);
1018 return error;
1019 }
1020
1021 /* Check all the dirents that we deferred the first time around. */
1022 STATIC int
1023 xchk_dir_finish_slow_dirents(
1024 struct xchk_dir *sd)
1025 {
1026 xfarray_idx_t array_cur;
1027 int error;
1028
1029 foreach_xfarray_idx(sd->dir_entries, array_cur) {
1030 struct xchk_dirent dirent;
1031
1032 if (sd->sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
1033 return 0;
1034
1035 error = xfarray_load(sd->dir_entries, array_cur, &dirent);
1036 if (error)
1037 return error;
1038
1039 error = xfblob_loadname(sd->dir_names, dirent.name_cookie,
1040 &sd->xname, dirent.namelen);
1041 if (error)
1042 return error;
1043
1044 error = xchk_dir_slow_dirent(sd, &dirent, &sd->xname);
1045 if (error)
1046 return error;
1047 }
1048
1049 return 0;
1050 }
1051
1052 /* Scrub a whole directory. */
1053 int
1054 xchk_directory(
1055 struct xfs_scrub *sc)
1056 {
1057 struct xchk_dir *sd;
1058 int error;
1059
1060 if (!S_ISDIR(VFS_I(sc->ip)->i_mode))
1061 return -ENOENT;
1062
1063 if (xchk_file_looks_zapped(sc, XFS_SICK_INO_DIR_ZAPPED)) {
1064 xchk_fblock_set_corrupt(sc, XFS_DATA_FORK, 0);
1065 return 0;
1066 }
1067
1068 /* Plausible size? */
1069 if (sc->ip->i_disk_size < xfs_dir2_sf_hdr_size(0)) {
1070 xchk_ino_set_corrupt(sc, sc->ip->i_ino);
1071 return 0;
1072 }
1073
1074 /* Check directory tree structure */
1075 error = xchk_da_btree(sc, XFS_DATA_FORK, xchk_dir_rec, NULL);
1076 if (error)
1077 return error;
1078
1079 if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
1080 return 0;
1081
1082 /* Check the freespace. */
1083 error = xchk_directory_blocks(sc);
1084 if (error)
1085 return error;
1086
1087 if (sc->sm->sm_flags & XFS_SCRUB_OFLAG_CORRUPT)
1088 return 0;
1089
1090 sd = kvzalloc(sizeof(struct xchk_dir), XCHK_GFP_FLAGS);
1091 if (!sd)
1092 return -ENOMEM;
1093 sd->sc = sc;
1094 sd->xname.name = sd->namebuf;
1095
1096 if (xfs_has_parent(sc->mp)) {
1097 char *descr;
1098
1099 /*
1100 * Set up some staging memory for dirents that we can't check
1101 * due to locking contention.
1102 */
1103 descr = xchk_xfile_ino_descr(sc, "slow directory entries");
1104 error = xfarray_create(descr, 0, sizeof(struct xchk_dirent),
1105 &sd->dir_entries);
1106 kfree(descr);
1107 if (error)
1108 goto out_sd;
1109
1110 descr = xchk_xfile_ino_descr(sc, "slow directory entry names");
1111 error = xfblob_create(descr, &sd->dir_names);
1112 kfree(descr);
1113 if (error)
1114 goto out_entries;
1115 }
1116
1117 /* Look up every name in this directory by hash. */
1118 error = xchk_dir_walk(sc, sc->ip, xchk_dir_actor, sd);
1119 if (error == -ECANCELED)
1120 error = 0;
1121 if (error)
1122 goto out_names;
1123
1124 if (xfs_has_parent(sc->mp)) {
1125 error = xchk_dir_finish_slow_dirents(sd);
1126 if (error == -ETIMEDOUT) {
1127 /* Couldn't grab a lock, scrub was marked incomplete */
1128 error = 0;
1129 goto out_names;
1130 }
1131 if (error)
1132 goto out_names;
1133 }
1134
1135 out_names:
1136 if (sd->dir_names)
1137 xfblob_destroy(sd->dir_names);
1138 out_entries:
1139 if (sd->dir_entries)
1140 xfarray_destroy(sd->dir_entries);
1141 out_sd:
1142 kvfree(sd);
1143 if (error)
1144 return error;
1145
1146 /* If the dir is clean, it is clearly not zapped. */
1147 xchk_mark_healthy_if_clean(sc, XFS_SICK_INO_DIR_ZAPPED);
1148 return 0;
1149 }
1150
1151 /*
1152 * Decide if this directory has been zapped to satisfy the inode and ifork
1153 * verifiers. Checking and repairing should be postponed until the directory
1154 * is fixed.
1155 */
1156 bool
1157 xchk_dir_looks_zapped(
1158 struct xfs_inode *dp)
1159 {
1160 /* Repair zapped this dir's data fork a short time ago */
1161 if (xfs_ifork_zapped(dp, XFS_DATA_FORK))
1162 return true;
1163
1164 /*
1165 * If the dinode repair found a bad data fork, it will reset the fork
1166 * to extents format with zero records and wait for the bmapbtd
1167 * scrubber to reconstruct the block mappings. Directories always
1168 * contain some content, so this is a clear sign of a zapped directory.
1169 * The state checked by xfs_ifork_zapped is not persisted, so this is
1170 * the secondary strategy if repairs are interrupted by a crash or an
1171 * unmount.
1172 */
1173 return dp->i_df.if_format == XFS_DINODE_FMT_EXTENTS &&
1174 dp->i_df.if_nextents == 0;
1175 }
1176
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