1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Copyright (C) 2018-2023 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_sb.h"
16 #include "xfs_alloc.h"
17 #include "xfs_alloc_btree.h"
18 #include "xfs_ialloc.h"
19 #include "xfs_ialloc_btree.h"
20 #include "xfs_rmap.h"
21 #include "xfs_rmap_btree.h"
22 #include "xfs_refcount_btree.h"
23 #include "xfs_ag.h"
24 #include "xfs_inode.h"
25 #include "xfs_iunlink_item.h"
26 #include "scrub/scrub.h"
27 #include "scrub/common.h"
28 #include "scrub/trace.h"
29 #include "scrub/repair.h"
30 #include "scrub/bitmap.h"
31 #include "scrub/agb_bitmap.h"
32 #include "scrub/agino_bitmap.h"
33 #include "scrub/reap.h"
34 #include "scrub/xfile.h"
35 #include "scrub/xfarray.h"
36
37 /* Superblock */
38
39 /* Repair the superblock. */
40 int
41 xrep_superblock(
42 struct xfs_scrub *sc)
43 {
44 struct xfs_mount *mp = sc->mp;
45 struct xfs_buf *bp;
46 xfs_agnumber_t agno;
47 int error;
48
49 /* Don't try to repair AG 0's sb; let xfs_repair deal with it. */
50 agno = sc->sm->sm_agno;
51 if (agno == 0)
52 return -EOPNOTSUPP;
53
54 error = xfs_sb_get_secondary(mp, sc->tp, agno, &bp);
55 if (error)
56 return error;
57
58 /* Last chance to abort before we start committing fixes. */
59 if (xchk_should_terminate(sc, &error))
60 return error;
61
62 /* Copy AG 0's superblock to this one. */
63 xfs_buf_zero(bp, 0, BBTOB(bp->b_length));
64 xfs_sb_to_disk(bp->b_addr, &mp->m_sb);
65
66 /*
67 * Don't write out a secondary super with NEEDSREPAIR or log incompat
68 * features set, since both are ignored when set on a secondary.
69 */
70 if (xfs_has_crc(mp)) {
71 struct xfs_dsb *sb = bp->b_addr;
72
73 sb->sb_features_incompat &=
74 ~cpu_to_be32(XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR);
75 sb->sb_features_log_incompat = 0;
76 }
77
78 /* Write this to disk. */
79 xfs_trans_buf_set_type(sc->tp, bp, XFS_BLFT_SB_BUF);
80 xfs_trans_log_buf(sc->tp, bp, 0, BBTOB(bp->b_length) - 1);
81 return 0;
82 }
83
84 /* AGF */
85
86 struct xrep_agf_allocbt {
87 struct xfs_scrub *sc;
88 xfs_agblock_t freeblks;
89 xfs_agblock_t longest;
90 };
91
92 /* Record free space shape information. */
93 STATIC int
94 xrep_agf_walk_allocbt(
95 struct xfs_btree_cur *cur,
96 const struct xfs_alloc_rec_incore *rec,
97 void *priv)
98 {
99 struct xrep_agf_allocbt *raa = priv;
100 int error = 0;
101
102 if (xchk_should_terminate(raa->sc, &error))
103 return error;
104
105 raa->freeblks += rec->ar_blockcount;
106 if (rec->ar_blockcount > raa->longest)
107 raa->longest = rec->ar_blockcount;
108 return error;
109 }
110
111 /* Does this AGFL block look sane? */
112 STATIC int
113 xrep_agf_check_agfl_block(
114 struct xfs_mount *mp,
115 xfs_agblock_t agbno,
116 void *priv)
117 {
118 struct xfs_scrub *sc = priv;
119
120 if (!xfs_verify_agbno(sc->sa.pag, agbno))
121 return -EFSCORRUPTED;
122 return 0;
123 }
124
125 /*
126 * Offset within the xrep_find_ag_btree array for each btree type. Avoid the
127 * XFS_BTNUM_ names here to avoid creating a sparse array.
128 */
129 enum {
130 XREP_AGF_BNOBT = 0,
131 XREP_AGF_CNTBT,
132 XREP_AGF_RMAPBT,
133 XREP_AGF_REFCOUNTBT,
134 XREP_AGF_END,
135 XREP_AGF_MAX
136 };
137
138 /* Check a btree root candidate. */
139 static inline bool
140 xrep_check_btree_root(
141 struct xfs_scrub *sc,
142 struct xrep_find_ag_btree *fab)
143 {
144 return xfs_verify_agbno(sc->sa.pag, fab->root) &&
145 fab->height <= fab->maxlevels;
146 }
147
148 /*
149 * Given the btree roots described by *fab, find the roots, check them for
150 * sanity, and pass the root data back out via *fab.
151 *
152 * This is /also/ a chicken and egg problem because we have to use the rmapbt
153 * (rooted in the AGF) to find the btrees rooted in the AGF. We also have no
154 * idea if the btrees make any sense. If we hit obvious corruptions in those
155 * btrees we'll bail out.
156 */
157 STATIC int
158 xrep_agf_find_btrees(
159 struct xfs_scrub *sc,
160 struct xfs_buf *agf_bp,
161 struct xrep_find_ag_btree *fab,
162 struct xfs_buf *agfl_bp)
163 {
164 struct xfs_agf *old_agf = agf_bp->b_addr;
165 int error;
166
167 /* Go find the root data. */
168 error = xrep_find_ag_btree_roots(sc, agf_bp, fab, agfl_bp);
169 if (error)
170 return error;
171
172 /* We must find the bnobt, cntbt, and rmapbt roots. */
173 if (!xrep_check_btree_root(sc, &fab[XREP_AGF_BNOBT]) ||
174 !xrep_check_btree_root(sc, &fab[XREP_AGF_CNTBT]) ||
175 !xrep_check_btree_root(sc, &fab[XREP_AGF_RMAPBT]))
176 return -EFSCORRUPTED;
177
178 /*
179 * We relied on the rmapbt to reconstruct the AGF. If we get a
180 * different root then something's seriously wrong.
181 */
182 if (fab[XREP_AGF_RMAPBT].root != be32_to_cpu(old_agf->agf_rmap_root))
183 return -EFSCORRUPTED;
184
185 /* We must find the refcountbt root if that feature is enabled. */
186 if (xfs_has_reflink(sc->mp) &&
187 !xrep_check_btree_root(sc, &fab[XREP_AGF_REFCOUNTBT]))
188 return -EFSCORRUPTED;
189
190 return 0;
191 }
192
193 /*
194 * Reinitialize the AGF header, making an in-core copy of the old contents so
195 * that we know which in-core state needs to be reinitialized.
196 */
197 STATIC void
198 xrep_agf_init_header(
199 struct xfs_scrub *sc,
200 struct xfs_buf *agf_bp,
201 struct xfs_agf *old_agf)
202 {
203 struct xfs_mount *mp = sc->mp;
204 struct xfs_perag *pag = sc->sa.pag;
205 struct xfs_agf *agf = agf_bp->b_addr;
206
207 memcpy(old_agf, agf, sizeof(*old_agf));
208 memset(agf, 0, BBTOB(agf_bp->b_length));
209 agf->agf_magicnum = cpu_to_be32(XFS_AGF_MAGIC);
210 agf->agf_versionnum = cpu_to_be32(XFS_AGF_VERSION);
211 agf->agf_seqno = cpu_to_be32(pag->pag_agno);
212 agf->agf_length = cpu_to_be32(pag->block_count);
213 agf->agf_flfirst = old_agf->agf_flfirst;
214 agf->agf_fllast = old_agf->agf_fllast;
215 agf->agf_flcount = old_agf->agf_flcount;
216 if (xfs_has_crc(mp))
217 uuid_copy(&agf->agf_uuid, &mp->m_sb.sb_meta_uuid);
218
219 /* Mark the incore AGF data stale until we're done fixing things. */
220 ASSERT(xfs_perag_initialised_agf(pag));
221 clear_bit(XFS_AGSTATE_AGF_INIT, &pag->pag_opstate);
222 }
223
224 /* Set btree root information in an AGF. */
225 STATIC void
226 xrep_agf_set_roots(
227 struct xfs_scrub *sc,
228 struct xfs_agf *agf,
229 struct xrep_find_ag_btree *fab)
230 {
231 agf->agf_bno_root = cpu_to_be32(fab[XREP_AGF_BNOBT].root);
232 agf->agf_bno_level = cpu_to_be32(fab[XREP_AGF_BNOBT].height);
233
234 agf->agf_cnt_root = cpu_to_be32(fab[XREP_AGF_CNTBT].root);
235 agf->agf_cnt_level = cpu_to_be32(fab[XREP_AGF_CNTBT].height);
236
237 agf->agf_rmap_root = cpu_to_be32(fab[XREP_AGF_RMAPBT].root);
238 agf->agf_rmap_level = cpu_to_be32(fab[XREP_AGF_RMAPBT].height);
239
240 if (xfs_has_reflink(sc->mp)) {
241 agf->agf_refcount_root =
242 cpu_to_be32(fab[XREP_AGF_REFCOUNTBT].root);
243 agf->agf_refcount_level =
244 cpu_to_be32(fab[XREP_AGF_REFCOUNTBT].height);
245 }
246 }
247
248 /* Update all AGF fields which derive from btree contents. */
249 STATIC int
250 xrep_agf_calc_from_btrees(
251 struct xfs_scrub *sc,
252 struct xfs_buf *agf_bp)
253 {
254 struct xrep_agf_allocbt raa = { .sc = sc };
255 struct xfs_btree_cur *cur = NULL;
256 struct xfs_agf *agf = agf_bp->b_addr;
257 struct xfs_mount *mp = sc->mp;
258 xfs_agblock_t btreeblks;
259 xfs_agblock_t blocks;
260 int error;
261
262 /* Update the AGF counters from the bnobt. */
263 cur = xfs_bnobt_init_cursor(mp, sc->tp, agf_bp, sc->sa.pag);
264 error = xfs_alloc_query_all(cur, xrep_agf_walk_allocbt, &raa);
265 if (error)
266 goto err;
267 error = xfs_btree_count_blocks(cur, &blocks);
268 if (error)
269 goto err;
270 xfs_btree_del_cursor(cur, error);
271 btreeblks = blocks - 1;
272 agf->agf_freeblks = cpu_to_be32(raa.freeblks);
273 agf->agf_longest = cpu_to_be32(raa.longest);
274
275 /* Update the AGF counters from the cntbt. */
276 cur = xfs_cntbt_init_cursor(mp, sc->tp, agf_bp, sc->sa.pag);
277 error = xfs_btree_count_blocks(cur, &blocks);
278 if (error)
279 goto err;
280 xfs_btree_del_cursor(cur, error);
281 btreeblks += blocks - 1;
282
283 /* Update the AGF counters from the rmapbt. */
284 cur = xfs_rmapbt_init_cursor(mp, sc->tp, agf_bp, sc->sa.pag);
285 error = xfs_btree_count_blocks(cur, &blocks);
286 if (error)
287 goto err;
288 xfs_btree_del_cursor(cur, error);
289 agf->agf_rmap_blocks = cpu_to_be32(blocks);
290 btreeblks += blocks - 1;
291
292 agf->agf_btreeblks = cpu_to_be32(btreeblks);
293
294 /* Update the AGF counters from the refcountbt. */
295 if (xfs_has_reflink(mp)) {
296 cur = xfs_refcountbt_init_cursor(mp, sc->tp, agf_bp,
297 sc->sa.pag);
298 error = xfs_btree_count_blocks(cur, &blocks);
299 if (error)
300 goto err;
301 xfs_btree_del_cursor(cur, error);
302 agf->agf_refcount_blocks = cpu_to_be32(blocks);
303 }
304
305 return 0;
306 err:
307 xfs_btree_del_cursor(cur, error);
308 return error;
309 }
310
311 /* Commit the new AGF and reinitialize the incore state. */
312 STATIC int
313 xrep_agf_commit_new(
314 struct xfs_scrub *sc,
315 struct xfs_buf *agf_bp)
316 {
317 struct xfs_perag *pag;
318 struct xfs_agf *agf = agf_bp->b_addr;
319
320 /* Trigger fdblocks recalculation */
321 xfs_force_summary_recalc(sc->mp);
322
323 /* Write this to disk. */
324 xfs_trans_buf_set_type(sc->tp, agf_bp, XFS_BLFT_AGF_BUF);
325 xfs_trans_log_buf(sc->tp, agf_bp, 0, BBTOB(agf_bp->b_length) - 1);
326
327 /* Now reinitialize the in-core counters we changed. */
328 pag = sc->sa.pag;
329 pag->pagf_btreeblks = be32_to_cpu(agf->agf_btreeblks);
330 pag->pagf_freeblks = be32_to_cpu(agf->agf_freeblks);
331 pag->pagf_longest = be32_to_cpu(agf->agf_longest);
332 pag->pagf_bno_level = be32_to_cpu(agf->agf_bno_level);
333 pag->pagf_cnt_level = be32_to_cpu(agf->agf_cnt_level);
334 pag->pagf_rmap_level = be32_to_cpu(agf->agf_rmap_level);
335 pag->pagf_refcount_level = be32_to_cpu(agf->agf_refcount_level);
336 set_bit(XFS_AGSTATE_AGF_INIT, &pag->pag_opstate);
337
338 return xrep_roll_ag_trans(sc);
339 }
340
341 /* Repair the AGF. v5 filesystems only. */
342 int
343 xrep_agf(
344 struct xfs_scrub *sc)
345 {
346 struct xrep_find_ag_btree fab[XREP_AGF_MAX] = {
347 [XREP_AGF_BNOBT] = {
348 .rmap_owner = XFS_RMAP_OWN_AG,
349 .buf_ops = &xfs_bnobt_buf_ops,
350 .maxlevels = sc->mp->m_alloc_maxlevels,
351 },
352 [XREP_AGF_CNTBT] = {
353 .rmap_owner = XFS_RMAP_OWN_AG,
354 .buf_ops = &xfs_cntbt_buf_ops,
355 .maxlevels = sc->mp->m_alloc_maxlevels,
356 },
357 [XREP_AGF_RMAPBT] = {
358 .rmap_owner = XFS_RMAP_OWN_AG,
359 .buf_ops = &xfs_rmapbt_buf_ops,
360 .maxlevels = sc->mp->m_rmap_maxlevels,
361 },
362 [XREP_AGF_REFCOUNTBT] = {
363 .rmap_owner = XFS_RMAP_OWN_REFC,
364 .buf_ops = &xfs_refcountbt_buf_ops,
365 .maxlevels = sc->mp->m_refc_maxlevels,
366 },
367 [XREP_AGF_END] = {
368 .buf_ops = NULL,
369 },
370 };
371 struct xfs_agf old_agf;
372 struct xfs_mount *mp = sc->mp;
373 struct xfs_buf *agf_bp;
374 struct xfs_buf *agfl_bp;
375 struct xfs_agf *agf;
376 int error;
377
378 /* We require the rmapbt to rebuild anything. */
379 if (!xfs_has_rmapbt(mp))
380 return -EOPNOTSUPP;
381
382 /*
383 * Make sure we have the AGF buffer, as scrub might have decided it
384 * was corrupt after xfs_alloc_read_agf failed with -EFSCORRUPTED.
385 */
386 error = xfs_trans_read_buf(mp, sc->tp, mp->m_ddev_targp,
387 XFS_AG_DADDR(mp, sc->sa.pag->pag_agno,
388 XFS_AGF_DADDR(mp)),
389 XFS_FSS_TO_BB(mp, 1), 0, &agf_bp, NULL);
390 if (error)
391 return error;
392 agf_bp->b_ops = &xfs_agf_buf_ops;
393 agf = agf_bp->b_addr;
394
395 /*
396 * Load the AGFL so that we can screen out OWN_AG blocks that are on
397 * the AGFL now; these blocks might have once been part of the
398 * bno/cnt/rmap btrees but are not now. This is a chicken and egg
399 * problem: the AGF is corrupt, so we have to trust the AGFL contents
400 * because we can't do any serious cross-referencing with any of the
401 * btrees rooted in the AGF. If the AGFL contents are obviously bad
402 * then we'll bail out.
403 */
404 error = xfs_alloc_read_agfl(sc->sa.pag, sc->tp, &agfl_bp);
405 if (error)
406 return error;
407
408 /*
409 * Spot-check the AGFL blocks; if they're obviously corrupt then
410 * there's nothing we can do but bail out.
411 */
412 error = xfs_agfl_walk(sc->mp, agf_bp->b_addr, agfl_bp,
413 xrep_agf_check_agfl_block, sc);
414 if (error)
415 return error;
416
417 /*
418 * Find the AGF btree roots. This is also a chicken-and-egg situation;
419 * see the function for more details.
420 */
421 error = xrep_agf_find_btrees(sc, agf_bp, fab, agfl_bp);
422 if (error)
423 return error;
424
425 /* Last chance to abort before we start committing fixes. */
426 if (xchk_should_terminate(sc, &error))
427 return error;
428
429 /* Start rewriting the header and implant the btrees we found. */
430 xrep_agf_init_header(sc, agf_bp, &old_agf);
431 xrep_agf_set_roots(sc, agf, fab);
432 error = xrep_agf_calc_from_btrees(sc, agf_bp);
433 if (error)
434 goto out_revert;
435
436 /* Commit the changes and reinitialize incore state. */
437 return xrep_agf_commit_new(sc, agf_bp);
438
439 out_revert:
440 /* Mark the incore AGF state stale and revert the AGF. */
441 clear_bit(XFS_AGSTATE_AGF_INIT, &sc->sa.pag->pag_opstate);
442 memcpy(agf, &old_agf, sizeof(old_agf));
443 return error;
444 }
445
446 /* AGFL */
447
448 struct xrep_agfl {
449 /* Bitmap of alleged AGFL blocks that we're not going to add. */
450 struct xagb_bitmap crossed;
451
452 /* Bitmap of other OWN_AG metadata blocks. */
453 struct xagb_bitmap agmetablocks;
454
455 /* Bitmap of free space. */
456 struct xagb_bitmap *freesp;
457
458 /* rmapbt cursor for finding crosslinked blocks */
459 struct xfs_btree_cur *rmap_cur;
460
461 struct xfs_scrub *sc;
462 };
463
464 /* Record all OWN_AG (free space btree) information from the rmap data. */
465 STATIC int
466 xrep_agfl_walk_rmap(
467 struct xfs_btree_cur *cur,
468 const struct xfs_rmap_irec *rec,
469 void *priv)
470 {
471 struct xrep_agfl *ra = priv;
472 int error = 0;
473
474 if (xchk_should_terminate(ra->sc, &error))
475 return error;
476
477 /* Record all the OWN_AG blocks. */
478 if (rec->rm_owner == XFS_RMAP_OWN_AG) {
479 error = xagb_bitmap_set(ra->freesp, rec->rm_startblock,
480 rec->rm_blockcount);
481 if (error)
482 return error;
483 }
484
485 return xagb_bitmap_set_btcur_path(&ra->agmetablocks, cur);
486 }
487
488 /* Strike out the blocks that are cross-linked according to the rmapbt. */
489 STATIC int
490 xrep_agfl_check_extent(
491 uint32_t agbno,
492 uint32_t len,
493 void *priv)
494 {
495 struct xrep_agfl *ra = priv;
496 xfs_agblock_t last_agbno = agbno + len - 1;
497 int error;
498
499 while (agbno <= last_agbno) {
500 bool other_owners;
501
502 error = xfs_rmap_has_other_keys(ra->rmap_cur, agbno, 1,
503 &XFS_RMAP_OINFO_AG, &other_owners);
504 if (error)
505 return error;
506
507 if (other_owners) {
508 error = xagb_bitmap_set(&ra->crossed, agbno, 1);
509 if (error)
510 return error;
511 }
512
513 if (xchk_should_terminate(ra->sc, &error))
514 return error;
515 agbno++;
516 }
517
518 return 0;
519 }
520
521 /*
522 * Map out all the non-AGFL OWN_AG space in this AG so that we can deduce
523 * which blocks belong to the AGFL.
524 *
525 * Compute the set of old AGFL blocks by subtracting from the list of OWN_AG
526 * blocks the list of blocks owned by all other OWN_AG metadata (bnobt, cntbt,
527 * rmapbt). These are the old AGFL blocks, so return that list and the number
528 * of blocks we're actually going to put back on the AGFL.
529 */
530 STATIC int
531 xrep_agfl_collect_blocks(
532 struct xfs_scrub *sc,
533 struct xfs_buf *agf_bp,
534 struct xagb_bitmap *agfl_extents,
535 xfs_agblock_t *flcount)
536 {
537 struct xrep_agfl ra;
538 struct xfs_mount *mp = sc->mp;
539 struct xfs_btree_cur *cur;
540 int error;
541
542 ra.sc = sc;
543 ra.freesp = agfl_extents;
544 xagb_bitmap_init(&ra.agmetablocks);
545 xagb_bitmap_init(&ra.crossed);
546
547 /* Find all space used by the free space btrees & rmapbt. */
548 cur = xfs_rmapbt_init_cursor(mp, sc->tp, agf_bp, sc->sa.pag);
549 error = xfs_rmap_query_all(cur, xrep_agfl_walk_rmap, &ra);
550 xfs_btree_del_cursor(cur, error);
551 if (error)
552 goto out_bmp;
553
554 /* Find all blocks currently being used by the bnobt. */
555 cur = xfs_bnobt_init_cursor(mp, sc->tp, agf_bp, sc->sa.pag);
556 error = xagb_bitmap_set_btblocks(&ra.agmetablocks, cur);
557 xfs_btree_del_cursor(cur, error);
558 if (error)
559 goto out_bmp;
560
561 /* Find all blocks currently being used by the cntbt. */
562 cur = xfs_cntbt_init_cursor(mp, sc->tp, agf_bp, sc->sa.pag);
563 error = xagb_bitmap_set_btblocks(&ra.agmetablocks, cur);
564 xfs_btree_del_cursor(cur, error);
565 if (error)
566 goto out_bmp;
567
568 /*
569 * Drop the freesp meta blocks that are in use by btrees.
570 * The remaining blocks /should/ be AGFL blocks.
571 */
572 error = xagb_bitmap_disunion(agfl_extents, &ra.agmetablocks);
573 if (error)
574 goto out_bmp;
575
576 /* Strike out the blocks that are cross-linked. */
577 ra.rmap_cur = xfs_rmapbt_init_cursor(mp, sc->tp, agf_bp, sc->sa.pag);
578 error = xagb_bitmap_walk(agfl_extents, xrep_agfl_check_extent, &ra);
579 xfs_btree_del_cursor(ra.rmap_cur, error);
580 if (error)
581 goto out_bmp;
582 error = xagb_bitmap_disunion(agfl_extents, &ra.crossed);
583 if (error)
584 goto out_bmp;
585
586 /*
587 * Calculate the new AGFL size. If we found more blocks than fit in
588 * the AGFL we'll free them later.
589 */
590 *flcount = min_t(uint64_t, xagb_bitmap_hweight(agfl_extents),
591 xfs_agfl_size(mp));
592
593 out_bmp:
594 xagb_bitmap_destroy(&ra.crossed);
595 xagb_bitmap_destroy(&ra.agmetablocks);
596 return error;
597 }
598
599 /* Update the AGF and reset the in-core state. */
600 STATIC void
601 xrep_agfl_update_agf(
602 struct xfs_scrub *sc,
603 struct xfs_buf *agf_bp,
604 xfs_agblock_t flcount)
605 {
606 struct xfs_agf *agf = agf_bp->b_addr;
607
608 ASSERT(flcount <= xfs_agfl_size(sc->mp));
609
610 /* Trigger fdblocks recalculation */
611 xfs_force_summary_recalc(sc->mp);
612
613 /* Update the AGF counters. */
614 if (xfs_perag_initialised_agf(sc->sa.pag)) {
615 sc->sa.pag->pagf_flcount = flcount;
616 clear_bit(XFS_AGSTATE_AGFL_NEEDS_RESET,
617 &sc->sa.pag->pag_opstate);
618 }
619 agf->agf_flfirst = cpu_to_be32(0);
620 agf->agf_flcount = cpu_to_be32(flcount);
621 if (flcount)
622 agf->agf_fllast = cpu_to_be32(flcount - 1);
623 else
624 agf->agf_fllast = cpu_to_be32(xfs_agfl_size(sc->mp) - 1);
625
626 xfs_alloc_log_agf(sc->tp, agf_bp,
627 XFS_AGF_FLFIRST | XFS_AGF_FLLAST | XFS_AGF_FLCOUNT);
628 }
629
630 struct xrep_agfl_fill {
631 struct xagb_bitmap used_extents;
632 struct xfs_scrub *sc;
633 __be32 *agfl_bno;
634 xfs_agblock_t flcount;
635 unsigned int fl_off;
636 };
637
638 /* Fill the AGFL with whatever blocks are in this extent. */
639 static int
640 xrep_agfl_fill(
641 uint32_t start,
642 uint32_t len,
643 void *priv)
644 {
645 struct xrep_agfl_fill *af = priv;
646 struct xfs_scrub *sc = af->sc;
647 xfs_agblock_t agbno = start;
648 int error;
649
650 trace_xrep_agfl_insert(sc->sa.pag, agbno, len);
651
652 while (agbno < start + len && af->fl_off < af->flcount)
653 af->agfl_bno[af->fl_off++] = cpu_to_be32(agbno++);
654
655 error = xagb_bitmap_set(&af->used_extents, start, agbno - 1);
656 if (error)
657 return error;
658
659 if (af->fl_off == af->flcount)
660 return -ECANCELED;
661
662 return 0;
663 }
664
665 /* Write out a totally new AGFL. */
666 STATIC int
667 xrep_agfl_init_header(
668 struct xfs_scrub *sc,
669 struct xfs_buf *agfl_bp,
670 struct xagb_bitmap *agfl_extents,
671 xfs_agblock_t flcount)
672 {
673 struct xrep_agfl_fill af = {
674 .sc = sc,
675 .flcount = flcount,
676 };
677 struct xfs_mount *mp = sc->mp;
678 struct xfs_agfl *agfl;
679 int error;
680
681 ASSERT(flcount <= xfs_agfl_size(mp));
682
683 /*
684 * Start rewriting the header by setting the bno[] array to
685 * NULLAGBLOCK, then setting AGFL header fields.
686 */
687 agfl = XFS_BUF_TO_AGFL(agfl_bp);
688 memset(agfl, 0xFF, BBTOB(agfl_bp->b_length));
689 agfl->agfl_magicnum = cpu_to_be32(XFS_AGFL_MAGIC);
690 agfl->agfl_seqno = cpu_to_be32(sc->sa.pag->pag_agno);
691 uuid_copy(&agfl->agfl_uuid, &mp->m_sb.sb_meta_uuid);
692
693 /*
694 * Fill the AGFL with the remaining blocks. If agfl_extents has more
695 * blocks than fit in the AGFL, they will be freed in a subsequent
696 * step.
697 */
698 xagb_bitmap_init(&af.used_extents);
699 af.agfl_bno = xfs_buf_to_agfl_bno(agfl_bp);
700 xagb_bitmap_walk(agfl_extents, xrep_agfl_fill, &af);
701 error = xagb_bitmap_disunion(agfl_extents, &af.used_extents);
702 if (error)
703 return error;
704
705 /* Write new AGFL to disk. */
706 xfs_trans_buf_set_type(sc->tp, agfl_bp, XFS_BLFT_AGFL_BUF);
707 xfs_trans_log_buf(sc->tp, agfl_bp, 0, BBTOB(agfl_bp->b_length) - 1);
708 xagb_bitmap_destroy(&af.used_extents);
709 return 0;
710 }
711
712 /* Repair the AGFL. */
713 int
714 xrep_agfl(
715 struct xfs_scrub *sc)
716 {
717 struct xagb_bitmap agfl_extents;
718 struct xfs_mount *mp = sc->mp;
719 struct xfs_buf *agf_bp;
720 struct xfs_buf *agfl_bp;
721 xfs_agblock_t flcount;
722 int error;
723
724 /* We require the rmapbt to rebuild anything. */
725 if (!xfs_has_rmapbt(mp))
726 return -EOPNOTSUPP;
727
728 xagb_bitmap_init(&agfl_extents);
729
730 /*
731 * Read the AGF so that we can query the rmapbt. We hope that there's
732 * nothing wrong with the AGF, but all the AG header repair functions
733 * have this chicken-and-egg problem.
734 */
735 error = xfs_alloc_read_agf(sc->sa.pag, sc->tp, 0, &agf_bp);
736 if (error)
737 return error;
738
739 /*
740 * Make sure we have the AGFL buffer, as scrub might have decided it
741 * was corrupt after xfs_alloc_read_agfl failed with -EFSCORRUPTED.
742 */
743 error = xfs_trans_read_buf(mp, sc->tp, mp->m_ddev_targp,
744 XFS_AG_DADDR(mp, sc->sa.pag->pag_agno,
745 XFS_AGFL_DADDR(mp)),
746 XFS_FSS_TO_BB(mp, 1), 0, &agfl_bp, NULL);
747 if (error)
748 return error;
749 agfl_bp->b_ops = &xfs_agfl_buf_ops;
750
751 /* Gather all the extents we're going to put on the new AGFL. */
752 error = xrep_agfl_collect_blocks(sc, agf_bp, &agfl_extents, &flcount);
753 if (error)
754 goto err;
755
756 /* Last chance to abort before we start committing fixes. */
757 if (xchk_should_terminate(sc, &error))
758 goto err;
759
760 /*
761 * Update AGF and AGFL. We reset the global free block counter when
762 * we adjust the AGF flcount (which can fail) so avoid updating any
763 * buffers until we know that part works.
764 */
765 xrep_agfl_update_agf(sc, agf_bp, flcount);
766 error = xrep_agfl_init_header(sc, agfl_bp, &agfl_extents, flcount);
767 if (error)
768 goto err;
769
770 /*
771 * Ok, the AGFL should be ready to go now. Roll the transaction to
772 * make the new AGFL permanent before we start using it to return
773 * freespace overflow to the freespace btrees.
774 */
775 sc->sa.agf_bp = agf_bp;
776 error = xrep_roll_ag_trans(sc);
777 if (error)
778 goto err;
779
780 /* Dump any AGFL overflow. */
781 error = xrep_reap_agblocks(sc, &agfl_extents, &XFS_RMAP_OINFO_AG,
782 XFS_AG_RESV_AGFL);
783 if (error)
784 goto err;
785
786 err:
787 xagb_bitmap_destroy(&agfl_extents);
788 return error;
789 }
790
791 /* AGI */
792
793 /*
794 * Offset within the xrep_find_ag_btree array for each btree type. Avoid the
795 * XFS_BTNUM_ names here to avoid creating a sparse array.
796 */
797 enum {
798 XREP_AGI_INOBT = 0,
799 XREP_AGI_FINOBT,
800 XREP_AGI_END,
801 XREP_AGI_MAX
802 };
803
804 #define XREP_AGI_LOOKUP_BATCH 32
805
806 struct xrep_agi {
807 struct xfs_scrub *sc;
808
809 /* AGI buffer, tracked separately */
810 struct xfs_buf *agi_bp;
811
812 /* context for finding btree roots */
813 struct xrep_find_ag_btree fab[XREP_AGI_MAX];
814
815 /* old AGI contents in case we have to revert */
816 struct xfs_agi old_agi;
817
818 /* bitmap of which inodes are unlinked */
819 struct xagino_bitmap iunlink_bmp;
820
821 /* heads of the unlinked inode bucket lists */
822 xfs_agino_t iunlink_heads[XFS_AGI_UNLINKED_BUCKETS];
823
824 /* scratchpad for batched lookups of the radix tree */
825 struct xfs_inode *lookup_batch[XREP_AGI_LOOKUP_BATCH];
826
827 /* Map of ino -> next_ino for unlinked inode processing. */
828 struct xfarray *iunlink_next;
829
830 /* Map of ino -> prev_ino for unlinked inode processing. */
831 struct xfarray *iunlink_prev;
832 };
833
834 static void
835 xrep_agi_buf_cleanup(
836 void *buf)
837 {
838 struct xrep_agi *ragi = buf;
839
840 xfarray_destroy(ragi->iunlink_prev);
841 xfarray_destroy(ragi->iunlink_next);
842 xagino_bitmap_destroy(&ragi->iunlink_bmp);
843 }
844
845 /*
846 * Given the inode btree roots described by *fab, find the roots, check them
847 * for sanity, and pass the root data back out via *fab.
848 */
849 STATIC int
850 xrep_agi_find_btrees(
851 struct xrep_agi *ragi)
852 {
853 struct xfs_scrub *sc = ragi->sc;
854 struct xrep_find_ag_btree *fab = ragi->fab;
855 struct xfs_buf *agf_bp;
856 struct xfs_mount *mp = sc->mp;
857 int error;
858
859 /* Read the AGF. */
860 error = xfs_alloc_read_agf(sc->sa.pag, sc->tp, 0, &agf_bp);
861 if (error)
862 return error;
863
864 /* Find the btree roots. */
865 error = xrep_find_ag_btree_roots(sc, agf_bp, fab, NULL);
866 if (error)
867 return error;
868
869 /* We must find the inobt root. */
870 if (!xrep_check_btree_root(sc, &fab[XREP_AGI_INOBT]))
871 return -EFSCORRUPTED;
872
873 /* We must find the finobt root if that feature is enabled. */
874 if (xfs_has_finobt(mp) &&
875 !xrep_check_btree_root(sc, &fab[XREP_AGI_FINOBT]))
876 return -EFSCORRUPTED;
877
878 return 0;
879 }
880
881 /*
882 * Reinitialize the AGI header, making an in-core copy of the old contents so
883 * that we know which in-core state needs to be reinitialized.
884 */
885 STATIC void
886 xrep_agi_init_header(
887 struct xrep_agi *ragi)
888 {
889 struct xfs_scrub *sc = ragi->sc;
890 struct xfs_buf *agi_bp = ragi->agi_bp;
891 struct xfs_agi *old_agi = &ragi->old_agi;
892 struct xfs_agi *agi = agi_bp->b_addr;
893 struct xfs_perag *pag = sc->sa.pag;
894 struct xfs_mount *mp = sc->mp;
895
896 memcpy(old_agi, agi, sizeof(*old_agi));
897 memset(agi, 0, BBTOB(agi_bp->b_length));
898 agi->agi_magicnum = cpu_to_be32(XFS_AGI_MAGIC);
899 agi->agi_versionnum = cpu_to_be32(XFS_AGI_VERSION);
900 agi->agi_seqno = cpu_to_be32(pag->pag_agno);
901 agi->agi_length = cpu_to_be32(pag->block_count);
902 agi->agi_newino = cpu_to_be32(NULLAGINO);
903 agi->agi_dirino = cpu_to_be32(NULLAGINO);
904 if (xfs_has_crc(mp))
905 uuid_copy(&agi->agi_uuid, &mp->m_sb.sb_meta_uuid);
906
907 /* Mark the incore AGF data stale until we're done fixing things. */
908 ASSERT(xfs_perag_initialised_agi(pag));
909 clear_bit(XFS_AGSTATE_AGI_INIT, &pag->pag_opstate);
910 }
911
912 /* Set btree root information in an AGI. */
913 STATIC void
914 xrep_agi_set_roots(
915 struct xrep_agi *ragi)
916 {
917 struct xfs_scrub *sc = ragi->sc;
918 struct xfs_agi *agi = ragi->agi_bp->b_addr;
919 struct xrep_find_ag_btree *fab = ragi->fab;
920
921 agi->agi_root = cpu_to_be32(fab[XREP_AGI_INOBT].root);
922 agi->agi_level = cpu_to_be32(fab[XREP_AGI_INOBT].height);
923
924 if (xfs_has_finobt(sc->mp)) {
925 agi->agi_free_root = cpu_to_be32(fab[XREP_AGI_FINOBT].root);
926 agi->agi_free_level = cpu_to_be32(fab[XREP_AGI_FINOBT].height);
927 }
928 }
929
930 /* Update the AGI counters. */
931 STATIC int
932 xrep_agi_calc_from_btrees(
933 struct xrep_agi *ragi)
934 {
935 struct xfs_scrub *sc = ragi->sc;
936 struct xfs_buf *agi_bp = ragi->agi_bp;
937 struct xfs_btree_cur *cur;
938 struct xfs_agi *agi = agi_bp->b_addr;
939 struct xfs_mount *mp = sc->mp;
940 xfs_agino_t count;
941 xfs_agino_t freecount;
942 int error;
943
944 cur = xfs_inobt_init_cursor(sc->sa.pag, sc->tp, agi_bp);
945 error = xfs_ialloc_count_inodes(cur, &count, &freecount);
946 if (error)
947 goto err;
948 if (xfs_has_inobtcounts(mp)) {
949 xfs_agblock_t blocks;
950
951 error = xfs_btree_count_blocks(cur, &blocks);
952 if (error)
953 goto err;
954 agi->agi_iblocks = cpu_to_be32(blocks);
955 }
956 xfs_btree_del_cursor(cur, error);
957
958 agi->agi_count = cpu_to_be32(count);
959 agi->agi_freecount = cpu_to_be32(freecount);
960
961 if (xfs_has_finobt(mp) && xfs_has_inobtcounts(mp)) {
962 xfs_agblock_t blocks;
963
964 cur = xfs_finobt_init_cursor(sc->sa.pag, sc->tp, agi_bp);
965 error = xfs_btree_count_blocks(cur, &blocks);
966 if (error)
967 goto err;
968 xfs_btree_del_cursor(cur, error);
969 agi->agi_fblocks = cpu_to_be32(blocks);
970 }
971
972 return 0;
973 err:
974 xfs_btree_del_cursor(cur, error);
975 return error;
976 }
977
978 /*
979 * Record a forwards unlinked chain pointer from agino -> next_agino in our
980 * staging information.
981 */
982 static inline int
983 xrep_iunlink_store_next(
984 struct xrep_agi *ragi,
985 xfs_agino_t agino,
986 xfs_agino_t next_agino)
987 {
988 ASSERT(next_agino != 0);
989
990 return xfarray_store(ragi->iunlink_next, agino, &next_agino);
991 }
992
993 /*
994 * Record a backwards unlinked chain pointer from prev_ino <- agino in our
995 * staging information.
996 */
997 static inline int
998 xrep_iunlink_store_prev(
999 struct xrep_agi *ragi,
1000 xfs_agino_t agino,
1001 xfs_agino_t prev_agino)
1002 {
1003 ASSERT(prev_agino != 0);
1004
1005 return xfarray_store(ragi->iunlink_prev, agino, &prev_agino);
1006 }
1007
1008 /*
1009 * Given an @agino, look up the next inode in the iunlink bucket. Returns
1010 * NULLAGINO if we're at the end of the chain, 0 if @agino is not in memory
1011 * like it should be, or a per-AG inode number.
1012 */
1013 static inline xfs_agino_t
1014 xrep_iunlink_next(
1015 struct xfs_scrub *sc,
1016 xfs_agino_t agino)
1017 {
1018 struct xfs_inode *ip;
1019
1020 ip = xfs_iunlink_lookup(sc->sa.pag, agino);
1021 if (!ip)
1022 return 0;
1023
1024 return ip->i_next_unlinked;
1025 }
1026
1027 /*
1028 * Load the inode @agino into memory, set its i_prev_unlinked, and drop the
1029 * inode so it can be inactivated. Returns NULLAGINO if we're at the end of
1030 * the chain or if we should stop walking the chain due to corruption; or a
1031 * per-AG inode number.
1032 */
1033 STATIC xfs_agino_t
1034 xrep_iunlink_reload_next(
1035 struct xrep_agi *ragi,
1036 xfs_agino_t prev_agino,
1037 xfs_agino_t agino)
1038 {
1039 struct xfs_scrub *sc = ragi->sc;
1040 struct xfs_inode *ip;
1041 xfs_ino_t ino;
1042 xfs_agino_t ret = NULLAGINO;
1043 int error;
1044
1045 ino = XFS_AGINO_TO_INO(sc->mp, sc->sa.pag->pag_agno, agino);
1046 error = xchk_iget(ragi->sc, ino, &ip);
1047 if (error)
1048 return ret;
1049
1050 trace_xrep_iunlink_reload_next(ip, prev_agino);
1051
1052 /* If this is a linked inode, stop processing the chain. */
1053 if (VFS_I(ip)->i_nlink != 0) {
1054 xrep_iunlink_store_next(ragi, agino, NULLAGINO);
1055 goto rele;
1056 }
1057
1058 ip->i_prev_unlinked = prev_agino;
1059 ret = ip->i_next_unlinked;
1060
1061 /*
1062 * Drop the inode reference that we just took. We hold the AGI, so
1063 * this inode cannot move off the unlinked list and hence cannot be
1064 * reclaimed.
1065 */
1066 rele:
1067 xchk_irele(sc, ip);
1068 return ret;
1069 }
1070
1071 /*
1072 * Walk an AGI unlinked bucket's list to load incore any unlinked inodes that
1073 * still existed at mount time. This can happen if iunlink processing fails
1074 * during log recovery.
1075 */
1076 STATIC int
1077 xrep_iunlink_walk_ondisk_bucket(
1078 struct xrep_agi *ragi,
1079 unsigned int bucket)
1080 {
1081 struct xfs_scrub *sc = ragi->sc;
1082 struct xfs_agi *agi = sc->sa.agi_bp->b_addr;
1083 xfs_agino_t prev_agino = NULLAGINO;
1084 xfs_agino_t next_agino;
1085 int error = 0;
1086
1087 next_agino = be32_to_cpu(agi->agi_unlinked[bucket]);
1088 while (next_agino != NULLAGINO) {
1089 xfs_agino_t agino = next_agino;
1090
1091 if (xchk_should_terminate(ragi->sc, &error))
1092 return error;
1093
1094 trace_xrep_iunlink_walk_ondisk_bucket(sc->sa.pag, bucket,
1095 prev_agino, agino);
1096
1097 if (bucket != agino % XFS_AGI_UNLINKED_BUCKETS)
1098 break;
1099
1100 next_agino = xrep_iunlink_next(sc, agino);
1101 if (!next_agino)
1102 next_agino = xrep_iunlink_reload_next(ragi, prev_agino,
1103 agino);
1104
1105 prev_agino = agino;
1106 }
1107
1108 return 0;
1109 }
1110
1111 /* Decide if this is an unlinked inode in this AG. */
1112 STATIC bool
1113 xrep_iunlink_igrab(
1114 struct xfs_perag *pag,
1115 struct xfs_inode *ip)
1116 {
1117 struct xfs_mount *mp = pag->pag_mount;
1118
1119 if (XFS_INO_TO_AGNO(mp, ip->i_ino) != pag->pag_agno)
1120 return false;
1121
1122 if (!xfs_inode_on_unlinked_list(ip))
1123 return false;
1124
1125 return true;
1126 }
1127
1128 /*
1129 * Mark the given inode in the lookup batch in our unlinked inode bitmap, and
1130 * remember if this inode is the start of the unlinked chain.
1131 */
1132 STATIC int
1133 xrep_iunlink_visit(
1134 struct xrep_agi *ragi,
1135 unsigned int batch_idx)
1136 {
1137 struct xfs_mount *mp = ragi->sc->mp;
1138 struct xfs_inode *ip = ragi->lookup_batch[batch_idx];
1139 xfs_agino_t agino;
1140 unsigned int bucket;
1141 int error;
1142
1143 ASSERT(XFS_INO_TO_AGNO(mp, ip->i_ino) == ragi->sc->sa.pag->pag_agno);
1144 ASSERT(xfs_inode_on_unlinked_list(ip));
1145
1146 agino = XFS_INO_TO_AGINO(mp, ip->i_ino);
1147 bucket = agino % XFS_AGI_UNLINKED_BUCKETS;
1148
1149 trace_xrep_iunlink_visit(ragi->sc->sa.pag, bucket,
1150 ragi->iunlink_heads[bucket], ip);
1151
1152 error = xagino_bitmap_set(&ragi->iunlink_bmp, agino, 1);
1153 if (error)
1154 return error;
1155
1156 if (ip->i_prev_unlinked == NULLAGINO) {
1157 if (ragi->iunlink_heads[bucket] == NULLAGINO)
1158 ragi->iunlink_heads[bucket] = agino;
1159 }
1160
1161 return 0;
1162 }
1163
1164 /*
1165 * Find all incore unlinked inodes so that we can rebuild the unlinked buckets.
1166 * We hold the AGI so there should not be any modifications to the unlinked
1167 * list.
1168 */
1169 STATIC int
1170 xrep_iunlink_mark_incore(
1171 struct xrep_agi *ragi)
1172 {
1173 struct xfs_perag *pag = ragi->sc->sa.pag;
1174 struct xfs_mount *mp = pag->pag_mount;
1175 uint32_t first_index = 0;
1176 bool done = false;
1177 unsigned int nr_found = 0;
1178
1179 do {
1180 unsigned int i;
1181 int error = 0;
1182
1183 if (xchk_should_terminate(ragi->sc, &error))
1184 return error;
1185
1186 rcu_read_lock();
1187
1188 nr_found = radix_tree_gang_lookup(&pag->pag_ici_root,
1189 (void **)&ragi->lookup_batch, first_index,
1190 XREP_AGI_LOOKUP_BATCH);
1191 if (!nr_found) {
1192 rcu_read_unlock();
1193 return 0;
1194 }
1195
1196 for (i = 0; i < nr_found; i++) {
1197 struct xfs_inode *ip = ragi->lookup_batch[i];
1198
1199 if (done || !xrep_iunlink_igrab(pag, ip))
1200 ragi->lookup_batch[i] = NULL;
1201
1202 /*
1203 * Update the index for the next lookup. Catch
1204 * overflows into the next AG range which can occur if
1205 * we have inodes in the last block of the AG and we
1206 * are currently pointing to the last inode.
1207 *
1208 * Because we may see inodes that are from the wrong AG
1209 * due to RCU freeing and reallocation, only update the
1210 * index if it lies in this AG. It was a race that lead
1211 * us to see this inode, so another lookup from the
1212 * same index will not find it again.
1213 */
1214 if (XFS_INO_TO_AGNO(mp, ip->i_ino) != pag->pag_agno)
1215 continue;
1216 first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1);
1217 if (first_index < XFS_INO_TO_AGINO(mp, ip->i_ino))
1218 done = true;
1219 }
1220
1221 /* unlock now we've grabbed the inodes. */
1222 rcu_read_unlock();
1223
1224 for (i = 0; i < nr_found; i++) {
1225 if (!ragi->lookup_batch[i])
1226 continue;
1227 error = xrep_iunlink_visit(ragi, i);
1228 if (error)
1229 return error;
1230 }
1231 } while (!done);
1232
1233 return 0;
1234 }
1235
1236 /* Mark all the unlinked ondisk inodes in this inobt record in iunlink_bmp. */
1237 STATIC int
1238 xrep_iunlink_mark_ondisk_rec(
1239 struct xfs_btree_cur *cur,
1240 const union xfs_btree_rec *rec,
1241 void *priv)
1242 {
1243 struct xfs_inobt_rec_incore irec;
1244 struct xrep_agi *ragi = priv;
1245 struct xfs_scrub *sc = ragi->sc;
1246 struct xfs_mount *mp = cur->bc_mp;
1247 xfs_agino_t agino;
1248 unsigned int i;
1249 int error = 0;
1250
1251 xfs_inobt_btrec_to_irec(mp, rec, &irec);
1252
1253 for (i = 0, agino = irec.ir_startino;
1254 i < XFS_INODES_PER_CHUNK;
1255 i++, agino++) {
1256 struct xfs_inode *ip;
1257 unsigned int len = 1;
1258
1259 /* Skip free inodes */
1260 if (XFS_INOBT_MASK(i) & irec.ir_free)
1261 continue;
1262 /* Skip inodes we've seen before */
1263 if (xagino_bitmap_test(&ragi->iunlink_bmp, agino, &len))
1264 continue;
1265
1266 /*
1267 * Skip incore inodes; these were already picked up by
1268 * the _mark_incore step.
1269 */
1270 rcu_read_lock();
1271 ip = radix_tree_lookup(&sc->sa.pag->pag_ici_root, agino);
1272 rcu_read_unlock();
1273 if (ip)
1274 continue;
1275
1276 /*
1277 * Try to look up this inode. If we can't get it, just move
1278 * on because we haven't actually scrubbed the inobt or the
1279 * inodes yet.
1280 */
1281 error = xchk_iget(ragi->sc,
1282 XFS_AGINO_TO_INO(mp, sc->sa.pag->pag_agno,
1283 agino),
1284 &ip);
1285 if (error)
1286 continue;
1287
1288 trace_xrep_iunlink_reload_ondisk(ip);
1289
1290 if (VFS_I(ip)->i_nlink == 0)
1291 error = xagino_bitmap_set(&ragi->iunlink_bmp, agino, 1);
1292 xchk_irele(sc, ip);
1293 if (error)
1294 break;
1295 }
1296
1297 return error;
1298 }
1299
1300 /*
1301 * Find ondisk inodes that are unlinked and not in cache, and mark them in
1302 * iunlink_bmp. We haven't checked the inobt yet, so we don't error out if
1303 * the btree is corrupt.
1304 */
1305 STATIC void
1306 xrep_iunlink_mark_ondisk(
1307 struct xrep_agi *ragi)
1308 {
1309 struct xfs_scrub *sc = ragi->sc;
1310 struct xfs_buf *agi_bp = ragi->agi_bp;
1311 struct xfs_btree_cur *cur;
1312 int error;
1313
1314 cur = xfs_inobt_init_cursor(sc->sa.pag, sc->tp, agi_bp);
1315 error = xfs_btree_query_all(cur, xrep_iunlink_mark_ondisk_rec, ragi);
1316 xfs_btree_del_cursor(cur, error);
1317 }
1318
1319 /*
1320 * Walk an iunlink bucket's inode list. For each inode that should be on this
1321 * chain, clear its entry in in iunlink_bmp because it's ok and we don't need
1322 * to touch it further.
1323 */
1324 STATIC int
1325 xrep_iunlink_resolve_bucket(
1326 struct xrep_agi *ragi,
1327 unsigned int bucket)
1328 {
1329 struct xfs_scrub *sc = ragi->sc;
1330 struct xfs_inode *ip;
1331 xfs_agino_t prev_agino = NULLAGINO;
1332 xfs_agino_t next_agino = ragi->iunlink_heads[bucket];
1333 int error = 0;
1334
1335 while (next_agino != NULLAGINO) {
1336 if (xchk_should_terminate(ragi->sc, &error))
1337 return error;
1338
1339 /* Find the next inode in the chain. */
1340 ip = xfs_iunlink_lookup(sc->sa.pag, next_agino);
1341 if (!ip) {
1342 /* Inode not incore? Terminate the chain. */
1343 trace_xrep_iunlink_resolve_uncached(sc->sa.pag,
1344 bucket, prev_agino, next_agino);
1345
1346 next_agino = NULLAGINO;
1347 break;
1348 }
1349
1350 if (next_agino % XFS_AGI_UNLINKED_BUCKETS != bucket) {
1351 /*
1352 * Inode is in the wrong bucket. Advance the list,
1353 * but pretend we didn't see this inode.
1354 */
1355 trace_xrep_iunlink_resolve_wronglist(sc->sa.pag,
1356 bucket, prev_agino, next_agino);
1357
1358 next_agino = ip->i_next_unlinked;
1359 continue;
1360 }
1361
1362 if (!xfs_inode_on_unlinked_list(ip)) {
1363 /*
1364 * Incore inode doesn't think this inode is on an
1365 * unlinked list. This is probably because we reloaded
1366 * it from disk. Advance the list, but pretend we
1367 * didn't see this inode; we'll fix that later.
1368 */
1369 trace_xrep_iunlink_resolve_nolist(sc->sa.pag,
1370 bucket, prev_agino, next_agino);
1371 next_agino = ip->i_next_unlinked;
1372 continue;
1373 }
1374
1375 trace_xrep_iunlink_resolve_ok(sc->sa.pag, bucket, prev_agino,
1376 next_agino);
1377
1378 /*
1379 * Otherwise, this inode's unlinked pointers are ok. Clear it
1380 * from the unlinked bitmap since we're done with it, and make
1381 * sure the chain is still correct.
1382 */
1383 error = xagino_bitmap_clear(&ragi->iunlink_bmp, next_agino, 1);
1384 if (error)
1385 return error;
1386
1387 /* Remember the previous inode's next pointer. */
1388 if (prev_agino != NULLAGINO) {
1389 error = xrep_iunlink_store_next(ragi, prev_agino,
1390 next_agino);
1391 if (error)
1392 return error;
1393 }
1394
1395 /* Remember this inode's previous pointer. */
1396 error = xrep_iunlink_store_prev(ragi, next_agino, prev_agino);
1397 if (error)
1398 return error;
1399
1400 /* Advance the list and remember this inode. */
1401 prev_agino = next_agino;
1402 next_agino = ip->i_next_unlinked;
1403 }
1404
1405 /* Update the previous inode's next pointer. */
1406 if (prev_agino != NULLAGINO) {
1407 error = xrep_iunlink_store_next(ragi, prev_agino, next_agino);
1408 if (error)
1409 return error;
1410 }
1411
1412 return 0;
1413 }
1414
1415 /* Reinsert this unlinked inode into the head of the staged bucket list. */
1416 STATIC int
1417 xrep_iunlink_add_to_bucket(
1418 struct xrep_agi *ragi,
1419 xfs_agino_t agino)
1420 {
1421 xfs_agino_t current_head;
1422 unsigned int bucket;
1423 int error;
1424
1425 bucket = agino % XFS_AGI_UNLINKED_BUCKETS;
1426
1427 /* Point this inode at the current head of the bucket list. */
1428 current_head = ragi->iunlink_heads[bucket];
1429
1430 trace_xrep_iunlink_add_to_bucket(ragi->sc->sa.pag, bucket, agino,
1431 current_head);
1432
1433 error = xrep_iunlink_store_next(ragi, agino, current_head);
1434 if (error)
1435 return error;
1436
1437 /* Remember the head inode's previous pointer. */
1438 if (current_head != NULLAGINO) {
1439 error = xrep_iunlink_store_prev(ragi, current_head, agino);
1440 if (error)
1441 return error;
1442 }
1443
1444 ragi->iunlink_heads[bucket] = agino;
1445 return 0;
1446 }
1447
1448 /* Reinsert unlinked inodes into the staged iunlink buckets. */
1449 STATIC int
1450 xrep_iunlink_add_lost_inodes(
1451 uint32_t start,
1452 uint32_t len,
1453 void *priv)
1454 {
1455 struct xrep_agi *ragi = priv;
1456 int error;
1457
1458 for (; len > 0; start++, len--) {
1459 error = xrep_iunlink_add_to_bucket(ragi, start);
1460 if (error)
1461 return error;
1462 }
1463
1464 return 0;
1465 }
1466
1467 /*
1468 * Figure out the iunlink bucket values and find inodes that need to be
1469 * reinserted into the list.
1470 */
1471 STATIC int
1472 xrep_iunlink_rebuild_buckets(
1473 struct xrep_agi *ragi)
1474 {
1475 unsigned int i;
1476 int error;
1477
1478 /*
1479 * Walk the ondisk AGI unlinked list to find inodes that are on the
1480 * list but aren't in memory. This can happen if a past log recovery
1481 * tried to clear the iunlinked list but failed. Our scan rebuilds the
1482 * unlinked list using incore inodes, so we must load and link them
1483 * properly.
1484 */
1485 for (i = 0; i < XFS_AGI_UNLINKED_BUCKETS; i++) {
1486 error = xrep_iunlink_walk_ondisk_bucket(ragi, i);
1487 if (error)
1488 return error;
1489 }
1490
1491 /*
1492 * Record all the incore unlinked inodes in iunlink_bmp that we didn't
1493 * find by walking the ondisk iunlink buckets. This shouldn't happen,
1494 * but we can't risk forgetting an inode somewhere.
1495 */
1496 error = xrep_iunlink_mark_incore(ragi);
1497 if (error)
1498 return error;
1499
1500 /*
1501 * If there are ondisk inodes that are unlinked and are not been loaded
1502 * into cache, record them in iunlink_bmp.
1503 */
1504 xrep_iunlink_mark_ondisk(ragi);
1505
1506 /*
1507 * Walk each iunlink bucket to (re)construct as much of the incore list
1508 * as would be correct. For each inode that survives this step, mark
1509 * it clear in iunlink_bmp; we're done with those inodes.
1510 */
1511 for (i = 0; i < XFS_AGI_UNLINKED_BUCKETS; i++) {
1512 error = xrep_iunlink_resolve_bucket(ragi, i);
1513 if (error)
1514 return error;
1515 }
1516
1517 /*
1518 * Any unlinked inodes that we didn't find through the bucket list
1519 * walk (or was ignored by the walk) must be inserted into the bucket
1520 * list. Stage this in memory for now.
1521 */
1522 return xagino_bitmap_walk(&ragi->iunlink_bmp,
1523 xrep_iunlink_add_lost_inodes, ragi);
1524 }
1525
1526 /* Update i_next_iunlinked for the inode @agino. */
1527 STATIC int
1528 xrep_iunlink_relink_next(
1529 struct xrep_agi *ragi,
1530 xfarray_idx_t idx,
1531 xfs_agino_t next_agino)
1532 {
1533 struct xfs_scrub *sc = ragi->sc;
1534 struct xfs_perag *pag = sc->sa.pag;
1535 struct xfs_inode *ip;
1536 xfarray_idx_t agino = idx - 1;
1537 bool want_rele = false;
1538 int error = 0;
1539
1540 ip = xfs_iunlink_lookup(pag, agino);
1541 if (!ip) {
1542 xfs_ino_t ino;
1543 xfs_agino_t prev_agino;
1544
1545 /*
1546 * No inode exists in cache. Load it off the disk so that we
1547 * can reinsert it into the incore unlinked list.
1548 */
1549 ino = XFS_AGINO_TO_INO(sc->mp, pag->pag_agno, agino);
1550 error = xchk_iget(sc, ino, &ip);
1551 if (error)
1552 return -EFSCORRUPTED;
1553
1554 want_rele = true;
1555
1556 /* Set the backward pointer since this just came off disk. */
1557 error = xfarray_load(ragi->iunlink_prev, agino, &prev_agino);
1558 if (error)
1559 goto out_rele;
1560
1561 trace_xrep_iunlink_relink_prev(ip, prev_agino);
1562 ip->i_prev_unlinked = prev_agino;
1563 }
1564
1565 /* Update the forward pointer. */
1566 if (ip->i_next_unlinked != next_agino) {
1567 error = xfs_iunlink_log_inode(sc->tp, ip, pag, next_agino);
1568 if (error)
1569 goto out_rele;
1570
1571 trace_xrep_iunlink_relink_next(ip, next_agino);
1572 ip->i_next_unlinked = next_agino;
1573 }
1574
1575 out_rele:
1576 /*
1577 * The iunlink lookup doesn't igrab because we hold the AGI buffer lock
1578 * and the inode cannot be reclaimed. However, if we used iget to load
1579 * a missing inode, we must irele it here.
1580 */
1581 if (want_rele)
1582 xchk_irele(sc, ip);
1583 return error;
1584 }
1585
1586 /* Update i_prev_iunlinked for the inode @agino. */
1587 STATIC int
1588 xrep_iunlink_relink_prev(
1589 struct xrep_agi *ragi,
1590 xfarray_idx_t idx,
1591 xfs_agino_t prev_agino)
1592 {
1593 struct xfs_scrub *sc = ragi->sc;
1594 struct xfs_perag *pag = sc->sa.pag;
1595 struct xfs_inode *ip;
1596 xfarray_idx_t agino = idx - 1;
1597 bool want_rele = false;
1598 int error = 0;
1599
1600 ASSERT(prev_agino != 0);
1601
1602 ip = xfs_iunlink_lookup(pag, agino);
1603 if (!ip) {
1604 xfs_ino_t ino;
1605 xfs_agino_t next_agino;
1606
1607 /*
1608 * No inode exists in cache. Load it off the disk so that we
1609 * can reinsert it into the incore unlinked list.
1610 */
1611 ino = XFS_AGINO_TO_INO(sc->mp, pag->pag_agno, agino);
1612 error = xchk_iget(sc, ino, &ip);
1613 if (error)
1614 return -EFSCORRUPTED;
1615
1616 want_rele = true;
1617
1618 /* Set the forward pointer since this just came off disk. */
1619 error = xfarray_load(ragi->iunlink_prev, agino, &next_agino);
1620 if (error)
1621 goto out_rele;
1622
1623 error = xfs_iunlink_log_inode(sc->tp, ip, pag, next_agino);
1624 if (error)
1625 goto out_rele;
1626
1627 trace_xrep_iunlink_relink_next(ip, next_agino);
1628 ip->i_next_unlinked = next_agino;
1629 }
1630
1631 /* Update the backward pointer. */
1632 if (ip->i_prev_unlinked != prev_agino) {
1633 trace_xrep_iunlink_relink_prev(ip, prev_agino);
1634 ip->i_prev_unlinked = prev_agino;
1635 }
1636
1637 out_rele:
1638 /*
1639 * The iunlink lookup doesn't igrab because we hold the AGI buffer lock
1640 * and the inode cannot be reclaimed. However, if we used iget to load
1641 * a missing inode, we must irele it here.
1642 */
1643 if (want_rele)
1644 xchk_irele(sc, ip);
1645 return error;
1646 }
1647
1648 /* Log all the iunlink updates we need to finish regenerating the AGI. */
1649 STATIC int
1650 xrep_iunlink_commit(
1651 struct xrep_agi *ragi)
1652 {
1653 struct xfs_agi *agi = ragi->agi_bp->b_addr;
1654 xfarray_idx_t idx = XFARRAY_CURSOR_INIT;
1655 xfs_agino_t agino;
1656 unsigned int i;
1657 int error;
1658
1659 /* Fix all the forward links */
1660 while ((error = xfarray_iter(ragi->iunlink_next, &idx, &agino)) == 1) {
1661 error = xrep_iunlink_relink_next(ragi, idx, agino);
1662 if (error)
1663 return error;
1664 }
1665
1666 /* Fix all the back links */
1667 idx = XFARRAY_CURSOR_INIT;
1668 while ((error = xfarray_iter(ragi->iunlink_prev, &idx, &agino)) == 1) {
1669 error = xrep_iunlink_relink_prev(ragi, idx, agino);
1670 if (error)
1671 return error;
1672 }
1673
1674 /* Copy the staged iunlink buckets to the new AGI. */
1675 for (i = 0; i < XFS_AGI_UNLINKED_BUCKETS; i++) {
1676 trace_xrep_iunlink_commit_bucket(ragi->sc->sa.pag, i,
1677 be32_to_cpu(ragi->old_agi.agi_unlinked[i]),
1678 ragi->iunlink_heads[i]);
1679
1680 agi->agi_unlinked[i] = cpu_to_be32(ragi->iunlink_heads[i]);
1681 }
1682
1683 return 0;
1684 }
1685
1686 /* Trigger reinitialization of the in-core data. */
1687 STATIC int
1688 xrep_agi_commit_new(
1689 struct xrep_agi *ragi)
1690 {
1691 struct xfs_scrub *sc = ragi->sc;
1692 struct xfs_buf *agi_bp = ragi->agi_bp;
1693 struct xfs_perag *pag;
1694 struct xfs_agi *agi = agi_bp->b_addr;
1695
1696 /* Trigger inode count recalculation */
1697 xfs_force_summary_recalc(sc->mp);
1698
1699 /* Write this to disk. */
1700 xfs_trans_buf_set_type(sc->tp, agi_bp, XFS_BLFT_AGI_BUF);
1701 xfs_trans_log_buf(sc->tp, agi_bp, 0, BBTOB(agi_bp->b_length) - 1);
1702
1703 /* Now reinitialize the in-core counters if necessary. */
1704 pag = sc->sa.pag;
1705 pag->pagi_count = be32_to_cpu(agi->agi_count);
1706 pag->pagi_freecount = be32_to_cpu(agi->agi_freecount);
1707 set_bit(XFS_AGSTATE_AGI_INIT, &pag->pag_opstate);
1708
1709 return xrep_roll_ag_trans(sc);
1710 }
1711
1712 /* Repair the AGI. */
1713 int
1714 xrep_agi(
1715 struct xfs_scrub *sc)
1716 {
1717 struct xrep_agi *ragi;
1718 struct xfs_mount *mp = sc->mp;
1719 char *descr;
1720 unsigned int i;
1721 int error;
1722
1723 /* We require the rmapbt to rebuild anything. */
1724 if (!xfs_has_rmapbt(mp))
1725 return -EOPNOTSUPP;
1726
1727 sc->buf = kzalloc(sizeof(struct xrep_agi), XCHK_GFP_FLAGS);
1728 if (!sc->buf)
1729 return -ENOMEM;
1730 ragi = sc->buf;
1731 ragi->sc = sc;
1732
1733 ragi->fab[XREP_AGI_INOBT] = (struct xrep_find_ag_btree){
1734 .rmap_owner = XFS_RMAP_OWN_INOBT,
1735 .buf_ops = &xfs_inobt_buf_ops,
1736 .maxlevels = M_IGEO(sc->mp)->inobt_maxlevels,
1737 };
1738 ragi->fab[XREP_AGI_FINOBT] = (struct xrep_find_ag_btree){
1739 .rmap_owner = XFS_RMAP_OWN_INOBT,
1740 .buf_ops = &xfs_finobt_buf_ops,
1741 .maxlevels = M_IGEO(sc->mp)->inobt_maxlevels,
1742 };
1743 ragi->fab[XREP_AGI_END] = (struct xrep_find_ag_btree){
1744 .buf_ops = NULL,
1745 };
1746
1747 for (i = 0; i < XFS_AGI_UNLINKED_BUCKETS; i++)
1748 ragi->iunlink_heads[i] = NULLAGINO;
1749
1750 xagino_bitmap_init(&ragi->iunlink_bmp);
1751 sc->buf_cleanup = xrep_agi_buf_cleanup;
1752
1753 descr = xchk_xfile_ag_descr(sc, "iunlinked next pointers");
1754 error = xfarray_create(descr, 0, sizeof(xfs_agino_t),
1755 &ragi->iunlink_next);
1756 kfree(descr);
1757 if (error)
1758 return error;
1759
1760 descr = xchk_xfile_ag_descr(sc, "iunlinked prev pointers");
1761 error = xfarray_create(descr, 0, sizeof(xfs_agino_t),
1762 &ragi->iunlink_prev);
1763 kfree(descr);
1764 if (error)
1765 return error;
1766
1767 /*
1768 * Make sure we have the AGI buffer, as scrub might have decided it
1769 * was corrupt after xfs_ialloc_read_agi failed with -EFSCORRUPTED.
1770 */
1771 error = xfs_trans_read_buf(mp, sc->tp, mp->m_ddev_targp,
1772 XFS_AG_DADDR(mp, sc->sa.pag->pag_agno,
1773 XFS_AGI_DADDR(mp)),
1774 XFS_FSS_TO_BB(mp, 1), 0, &ragi->agi_bp, NULL);
1775 if (error)
1776 return error;
1777 ragi->agi_bp->b_ops = &xfs_agi_buf_ops;
1778
1779 /* Find the AGI btree roots. */
1780 error = xrep_agi_find_btrees(ragi);
1781 if (error)
1782 return error;
1783
1784 error = xrep_iunlink_rebuild_buckets(ragi);
1785 if (error)
1786 return error;
1787
1788 /* Last chance to abort before we start committing fixes. */
1789 if (xchk_should_terminate(sc, &error))
1790 return error;
1791
1792 /* Start rewriting the header and implant the btrees we found. */
1793 xrep_agi_init_header(ragi);
1794 xrep_agi_set_roots(ragi);
1795 error = xrep_agi_calc_from_btrees(ragi);
1796 if (error)
1797 goto out_revert;
1798 error = xrep_iunlink_commit(ragi);
1799 if (error)
1800 goto out_revert;
1801
1802 /* Reinitialize in-core state. */
1803 return xrep_agi_commit_new(ragi);
1804
1805 out_revert:
1806 /* Mark the incore AGI state stale and revert the AGI. */
1807 clear_bit(XFS_AGSTATE_AGI_INIT, &sc->sa.pag->pag_opstate);
1808 memcpy(ragi->agi_bp->b_addr, &ragi->old_agi, sizeof(struct xfs_agi));
1809 return error;
1810 }
1811
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