xref: /linux/fs/xfs/scrub/agheader_repair.c (revision eb01fe7abbe2d0b38824d2a93fdb4cc3eaf2ccc1)
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 "scrub/scrub.h"
25 #include "scrub/common.h"
26 #include "scrub/trace.h"
27 #include "scrub/repair.h"
28 #include "scrub/bitmap.h"
29 #include "scrub/agb_bitmap.h"
30 #include "scrub/reap.h"
31 
32 /* Superblock */
33 
34 /* Repair the superblock. */
35 int
36 xrep_superblock(
37 	struct xfs_scrub	*sc)
38 {
39 	struct xfs_mount	*mp = sc->mp;
40 	struct xfs_buf		*bp;
41 	xfs_agnumber_t		agno;
42 	int			error;
43 
44 	/* Don't try to repair AG 0's sb; let xfs_repair deal with it. */
45 	agno = sc->sm->sm_agno;
46 	if (agno == 0)
47 		return -EOPNOTSUPP;
48 
49 	error = xfs_sb_get_secondary(mp, sc->tp, agno, &bp);
50 	if (error)
51 		return error;
52 
53 	/* Last chance to abort before we start committing fixes. */
54 	if (xchk_should_terminate(sc, &error))
55 		return error;
56 
57 	/* Copy AG 0's superblock to this one. */
58 	xfs_buf_zero(bp, 0, BBTOB(bp->b_length));
59 	xfs_sb_to_disk(bp->b_addr, &mp->m_sb);
60 
61 	/*
62 	 * Don't write out a secondary super with NEEDSREPAIR or log incompat
63 	 * features set, since both are ignored when set on a secondary.
64 	 */
65 	if (xfs_has_crc(mp)) {
66 		struct xfs_dsb		*sb = bp->b_addr;
67 
68 		sb->sb_features_incompat &=
69 				~cpu_to_be32(XFS_SB_FEAT_INCOMPAT_NEEDSREPAIR);
70 		sb->sb_features_log_incompat = 0;
71 	}
72 
73 	/* Write this to disk. */
74 	xfs_trans_buf_set_type(sc->tp, bp, XFS_BLFT_SB_BUF);
75 	xfs_trans_log_buf(sc->tp, bp, 0, BBTOB(bp->b_length) - 1);
76 	return 0;
77 }
78 
79 /* AGF */
80 
81 struct xrep_agf_allocbt {
82 	struct xfs_scrub	*sc;
83 	xfs_agblock_t		freeblks;
84 	xfs_agblock_t		longest;
85 };
86 
87 /* Record free space shape information. */
88 STATIC int
89 xrep_agf_walk_allocbt(
90 	struct xfs_btree_cur		*cur,
91 	const struct xfs_alloc_rec_incore *rec,
92 	void				*priv)
93 {
94 	struct xrep_agf_allocbt		*raa = priv;
95 	int				error = 0;
96 
97 	if (xchk_should_terminate(raa->sc, &error))
98 		return error;
99 
100 	raa->freeblks += rec->ar_blockcount;
101 	if (rec->ar_blockcount > raa->longest)
102 		raa->longest = rec->ar_blockcount;
103 	return error;
104 }
105 
106 /* Does this AGFL block look sane? */
107 STATIC int
108 xrep_agf_check_agfl_block(
109 	struct xfs_mount	*mp,
110 	xfs_agblock_t		agbno,
111 	void			*priv)
112 {
113 	struct xfs_scrub	*sc = priv;
114 
115 	if (!xfs_verify_agbno(sc->sa.pag, agbno))
116 		return -EFSCORRUPTED;
117 	return 0;
118 }
119 
120 /*
121  * Offset within the xrep_find_ag_btree array for each btree type.  Avoid the
122  * XFS_BTNUM_ names here to avoid creating a sparse array.
123  */
124 enum {
125 	XREP_AGF_BNOBT = 0,
126 	XREP_AGF_CNTBT,
127 	XREP_AGF_RMAPBT,
128 	XREP_AGF_REFCOUNTBT,
129 	XREP_AGF_END,
130 	XREP_AGF_MAX
131 };
132 
133 /* Check a btree root candidate. */
134 static inline bool
135 xrep_check_btree_root(
136 	struct xfs_scrub		*sc,
137 	struct xrep_find_ag_btree	*fab)
138 {
139 	return xfs_verify_agbno(sc->sa.pag, fab->root) &&
140 	       fab->height <= fab->maxlevels;
141 }
142 
143 /*
144  * Given the btree roots described by *fab, find the roots, check them for
145  * sanity, and pass the root data back out via *fab.
146  *
147  * This is /also/ a chicken and egg problem because we have to use the rmapbt
148  * (rooted in the AGF) to find the btrees rooted in the AGF.  We also have no
149  * idea if the btrees make any sense.  If we hit obvious corruptions in those
150  * btrees we'll bail out.
151  */
152 STATIC int
153 xrep_agf_find_btrees(
154 	struct xfs_scrub		*sc,
155 	struct xfs_buf			*agf_bp,
156 	struct xrep_find_ag_btree	*fab,
157 	struct xfs_buf			*agfl_bp)
158 {
159 	struct xfs_agf			*old_agf = agf_bp->b_addr;
160 	int				error;
161 
162 	/* Go find the root data. */
163 	error = xrep_find_ag_btree_roots(sc, agf_bp, fab, agfl_bp);
164 	if (error)
165 		return error;
166 
167 	/* We must find the bnobt, cntbt, and rmapbt roots. */
168 	if (!xrep_check_btree_root(sc, &fab[XREP_AGF_BNOBT]) ||
169 	    !xrep_check_btree_root(sc, &fab[XREP_AGF_CNTBT]) ||
170 	    !xrep_check_btree_root(sc, &fab[XREP_AGF_RMAPBT]))
171 		return -EFSCORRUPTED;
172 
173 	/*
174 	 * We relied on the rmapbt to reconstruct the AGF.  If we get a
175 	 * different root then something's seriously wrong.
176 	 */
177 	if (fab[XREP_AGF_RMAPBT].root != be32_to_cpu(old_agf->agf_rmap_root))
178 		return -EFSCORRUPTED;
179 
180 	/* We must find the refcountbt root if that feature is enabled. */
181 	if (xfs_has_reflink(sc->mp) &&
182 	    !xrep_check_btree_root(sc, &fab[XREP_AGF_REFCOUNTBT]))
183 		return -EFSCORRUPTED;
184 
185 	return 0;
186 }
187 
188 /*
189  * Reinitialize the AGF header, making an in-core copy of the old contents so
190  * that we know which in-core state needs to be reinitialized.
191  */
192 STATIC void
193 xrep_agf_init_header(
194 	struct xfs_scrub	*sc,
195 	struct xfs_buf		*agf_bp,
196 	struct xfs_agf		*old_agf)
197 {
198 	struct xfs_mount	*mp = sc->mp;
199 	struct xfs_perag	*pag = sc->sa.pag;
200 	struct xfs_agf		*agf = agf_bp->b_addr;
201 
202 	memcpy(old_agf, agf, sizeof(*old_agf));
203 	memset(agf, 0, BBTOB(agf_bp->b_length));
204 	agf->agf_magicnum = cpu_to_be32(XFS_AGF_MAGIC);
205 	agf->agf_versionnum = cpu_to_be32(XFS_AGF_VERSION);
206 	agf->agf_seqno = cpu_to_be32(pag->pag_agno);
207 	agf->agf_length = cpu_to_be32(pag->block_count);
208 	agf->agf_flfirst = old_agf->agf_flfirst;
209 	agf->agf_fllast = old_agf->agf_fllast;
210 	agf->agf_flcount = old_agf->agf_flcount;
211 	if (xfs_has_crc(mp))
212 		uuid_copy(&agf->agf_uuid, &mp->m_sb.sb_meta_uuid);
213 
214 	/* Mark the incore AGF data stale until we're done fixing things. */
215 	ASSERT(xfs_perag_initialised_agf(pag));
216 	clear_bit(XFS_AGSTATE_AGF_INIT, &pag->pag_opstate);
217 }
218 
219 /* Set btree root information in an AGF. */
220 STATIC void
221 xrep_agf_set_roots(
222 	struct xfs_scrub		*sc,
223 	struct xfs_agf			*agf,
224 	struct xrep_find_ag_btree	*fab)
225 {
226 	agf->agf_bno_root = cpu_to_be32(fab[XREP_AGF_BNOBT].root);
227 	agf->agf_bno_level = cpu_to_be32(fab[XREP_AGF_BNOBT].height);
228 
229 	agf->agf_cnt_root = cpu_to_be32(fab[XREP_AGF_CNTBT].root);
230 	agf->agf_cnt_level = cpu_to_be32(fab[XREP_AGF_CNTBT].height);
231 
232 	agf->agf_rmap_root = cpu_to_be32(fab[XREP_AGF_RMAPBT].root);
233 	agf->agf_rmap_level = cpu_to_be32(fab[XREP_AGF_RMAPBT].height);
234 
235 	if (xfs_has_reflink(sc->mp)) {
236 		agf->agf_refcount_root =
237 				cpu_to_be32(fab[XREP_AGF_REFCOUNTBT].root);
238 		agf->agf_refcount_level =
239 				cpu_to_be32(fab[XREP_AGF_REFCOUNTBT].height);
240 	}
241 }
242 
243 /* Update all AGF fields which derive from btree contents. */
244 STATIC int
245 xrep_agf_calc_from_btrees(
246 	struct xfs_scrub	*sc,
247 	struct xfs_buf		*agf_bp)
248 {
249 	struct xrep_agf_allocbt	raa = { .sc = sc };
250 	struct xfs_btree_cur	*cur = NULL;
251 	struct xfs_agf		*agf = agf_bp->b_addr;
252 	struct xfs_mount	*mp = sc->mp;
253 	xfs_agblock_t		btreeblks;
254 	xfs_agblock_t		blocks;
255 	int			error;
256 
257 	/* Update the AGF counters from the bnobt. */
258 	cur = xfs_bnobt_init_cursor(mp, sc->tp, agf_bp, sc->sa.pag);
259 	error = xfs_alloc_query_all(cur, xrep_agf_walk_allocbt, &raa);
260 	if (error)
261 		goto err;
262 	error = xfs_btree_count_blocks(cur, &blocks);
263 	if (error)
264 		goto err;
265 	xfs_btree_del_cursor(cur, error);
266 	btreeblks = blocks - 1;
267 	agf->agf_freeblks = cpu_to_be32(raa.freeblks);
268 	agf->agf_longest = cpu_to_be32(raa.longest);
269 
270 	/* Update the AGF counters from the cntbt. */
271 	cur = xfs_cntbt_init_cursor(mp, sc->tp, agf_bp, sc->sa.pag);
272 	error = xfs_btree_count_blocks(cur, &blocks);
273 	if (error)
274 		goto err;
275 	xfs_btree_del_cursor(cur, error);
276 	btreeblks += blocks - 1;
277 
278 	/* Update the AGF counters from the rmapbt. */
279 	cur = xfs_rmapbt_init_cursor(mp, sc->tp, agf_bp, sc->sa.pag);
280 	error = xfs_btree_count_blocks(cur, &blocks);
281 	if (error)
282 		goto err;
283 	xfs_btree_del_cursor(cur, error);
284 	agf->agf_rmap_blocks = cpu_to_be32(blocks);
285 	btreeblks += blocks - 1;
286 
287 	agf->agf_btreeblks = cpu_to_be32(btreeblks);
288 
289 	/* Update the AGF counters from the refcountbt. */
290 	if (xfs_has_reflink(mp)) {
291 		cur = xfs_refcountbt_init_cursor(mp, sc->tp, agf_bp,
292 				sc->sa.pag);
293 		error = xfs_btree_count_blocks(cur, &blocks);
294 		if (error)
295 			goto err;
296 		xfs_btree_del_cursor(cur, error);
297 		agf->agf_refcount_blocks = cpu_to_be32(blocks);
298 	}
299 
300 	return 0;
301 err:
302 	xfs_btree_del_cursor(cur, error);
303 	return error;
304 }
305 
306 /* Commit the new AGF and reinitialize the incore state. */
307 STATIC int
308 xrep_agf_commit_new(
309 	struct xfs_scrub	*sc,
310 	struct xfs_buf		*agf_bp)
311 {
312 	struct xfs_perag	*pag;
313 	struct xfs_agf		*agf = agf_bp->b_addr;
314 
315 	/* Trigger fdblocks recalculation */
316 	xfs_force_summary_recalc(sc->mp);
317 
318 	/* Write this to disk. */
319 	xfs_trans_buf_set_type(sc->tp, agf_bp, XFS_BLFT_AGF_BUF);
320 	xfs_trans_log_buf(sc->tp, agf_bp, 0, BBTOB(agf_bp->b_length) - 1);
321 
322 	/* Now reinitialize the in-core counters we changed. */
323 	pag = sc->sa.pag;
324 	pag->pagf_btreeblks = be32_to_cpu(agf->agf_btreeblks);
325 	pag->pagf_freeblks = be32_to_cpu(agf->agf_freeblks);
326 	pag->pagf_longest = be32_to_cpu(agf->agf_longest);
327 	pag->pagf_bno_level = be32_to_cpu(agf->agf_bno_level);
328 	pag->pagf_cnt_level = be32_to_cpu(agf->agf_cnt_level);
329 	pag->pagf_rmap_level = be32_to_cpu(agf->agf_rmap_level);
330 	pag->pagf_refcount_level = be32_to_cpu(agf->agf_refcount_level);
331 	set_bit(XFS_AGSTATE_AGF_INIT, &pag->pag_opstate);
332 
333 	return xrep_roll_ag_trans(sc);
334 }
335 
336 /* Repair the AGF. v5 filesystems only. */
337 int
338 xrep_agf(
339 	struct xfs_scrub		*sc)
340 {
341 	struct xrep_find_ag_btree	fab[XREP_AGF_MAX] = {
342 		[XREP_AGF_BNOBT] = {
343 			.rmap_owner = XFS_RMAP_OWN_AG,
344 			.buf_ops = &xfs_bnobt_buf_ops,
345 			.maxlevels = sc->mp->m_alloc_maxlevels,
346 		},
347 		[XREP_AGF_CNTBT] = {
348 			.rmap_owner = XFS_RMAP_OWN_AG,
349 			.buf_ops = &xfs_cntbt_buf_ops,
350 			.maxlevels = sc->mp->m_alloc_maxlevels,
351 		},
352 		[XREP_AGF_RMAPBT] = {
353 			.rmap_owner = XFS_RMAP_OWN_AG,
354 			.buf_ops = &xfs_rmapbt_buf_ops,
355 			.maxlevels = sc->mp->m_rmap_maxlevels,
356 		},
357 		[XREP_AGF_REFCOUNTBT] = {
358 			.rmap_owner = XFS_RMAP_OWN_REFC,
359 			.buf_ops = &xfs_refcountbt_buf_ops,
360 			.maxlevels = sc->mp->m_refc_maxlevels,
361 		},
362 		[XREP_AGF_END] = {
363 			.buf_ops = NULL,
364 		},
365 	};
366 	struct xfs_agf			old_agf;
367 	struct xfs_mount		*mp = sc->mp;
368 	struct xfs_buf			*agf_bp;
369 	struct xfs_buf			*agfl_bp;
370 	struct xfs_agf			*agf;
371 	int				error;
372 
373 	/* We require the rmapbt to rebuild anything. */
374 	if (!xfs_has_rmapbt(mp))
375 		return -EOPNOTSUPP;
376 
377 	/*
378 	 * Make sure we have the AGF buffer, as scrub might have decided it
379 	 * was corrupt after xfs_alloc_read_agf failed with -EFSCORRUPTED.
380 	 */
381 	error = xfs_trans_read_buf(mp, sc->tp, mp->m_ddev_targp,
382 			XFS_AG_DADDR(mp, sc->sa.pag->pag_agno,
383 						XFS_AGF_DADDR(mp)),
384 			XFS_FSS_TO_BB(mp, 1), 0, &agf_bp, NULL);
385 	if (error)
386 		return error;
387 	agf_bp->b_ops = &xfs_agf_buf_ops;
388 	agf = agf_bp->b_addr;
389 
390 	/*
391 	 * Load the AGFL so that we can screen out OWN_AG blocks that are on
392 	 * the AGFL now; these blocks might have once been part of the
393 	 * bno/cnt/rmap btrees but are not now.  This is a chicken and egg
394 	 * problem: the AGF is corrupt, so we have to trust the AGFL contents
395 	 * because we can't do any serious cross-referencing with any of the
396 	 * btrees rooted in the AGF.  If the AGFL contents are obviously bad
397 	 * then we'll bail out.
398 	 */
399 	error = xfs_alloc_read_agfl(sc->sa.pag, sc->tp, &agfl_bp);
400 	if (error)
401 		return error;
402 
403 	/*
404 	 * Spot-check the AGFL blocks; if they're obviously corrupt then
405 	 * there's nothing we can do but bail out.
406 	 */
407 	error = xfs_agfl_walk(sc->mp, agf_bp->b_addr, agfl_bp,
408 			xrep_agf_check_agfl_block, sc);
409 	if (error)
410 		return error;
411 
412 	/*
413 	 * Find the AGF btree roots.  This is also a chicken-and-egg situation;
414 	 * see the function for more details.
415 	 */
416 	error = xrep_agf_find_btrees(sc, agf_bp, fab, agfl_bp);
417 	if (error)
418 		return error;
419 
420 	/* Last chance to abort before we start committing fixes. */
421 	if (xchk_should_terminate(sc, &error))
422 		return error;
423 
424 	/* Start rewriting the header and implant the btrees we found. */
425 	xrep_agf_init_header(sc, agf_bp, &old_agf);
426 	xrep_agf_set_roots(sc, agf, fab);
427 	error = xrep_agf_calc_from_btrees(sc, agf_bp);
428 	if (error)
429 		goto out_revert;
430 
431 	/* Commit the changes and reinitialize incore state. */
432 	return xrep_agf_commit_new(sc, agf_bp);
433 
434 out_revert:
435 	/* Mark the incore AGF state stale and revert the AGF. */
436 	clear_bit(XFS_AGSTATE_AGF_INIT, &sc->sa.pag->pag_opstate);
437 	memcpy(agf, &old_agf, sizeof(old_agf));
438 	return error;
439 }
440 
441 /* AGFL */
442 
443 struct xrep_agfl {
444 	/* Bitmap of alleged AGFL blocks that we're not going to add. */
445 	struct xagb_bitmap	crossed;
446 
447 	/* Bitmap of other OWN_AG metadata blocks. */
448 	struct xagb_bitmap	agmetablocks;
449 
450 	/* Bitmap of free space. */
451 	struct xagb_bitmap	*freesp;
452 
453 	/* rmapbt cursor for finding crosslinked blocks */
454 	struct xfs_btree_cur	*rmap_cur;
455 
456 	struct xfs_scrub	*sc;
457 };
458 
459 /* Record all OWN_AG (free space btree) information from the rmap data. */
460 STATIC int
461 xrep_agfl_walk_rmap(
462 	struct xfs_btree_cur	*cur,
463 	const struct xfs_rmap_irec *rec,
464 	void			*priv)
465 {
466 	struct xrep_agfl	*ra = priv;
467 	int			error = 0;
468 
469 	if (xchk_should_terminate(ra->sc, &error))
470 		return error;
471 
472 	/* Record all the OWN_AG blocks. */
473 	if (rec->rm_owner == XFS_RMAP_OWN_AG) {
474 		error = xagb_bitmap_set(ra->freesp, rec->rm_startblock,
475 				rec->rm_blockcount);
476 		if (error)
477 			return error;
478 	}
479 
480 	return xagb_bitmap_set_btcur_path(&ra->agmetablocks, cur);
481 }
482 
483 /* Strike out the blocks that are cross-linked according to the rmapbt. */
484 STATIC int
485 xrep_agfl_check_extent(
486 	uint32_t		agbno,
487 	uint32_t		len,
488 	void			*priv)
489 {
490 	struct xrep_agfl	*ra = priv;
491 	xfs_agblock_t		last_agbno = agbno + len - 1;
492 	int			error;
493 
494 	while (agbno <= last_agbno) {
495 		bool		other_owners;
496 
497 		error = xfs_rmap_has_other_keys(ra->rmap_cur, agbno, 1,
498 				&XFS_RMAP_OINFO_AG, &other_owners);
499 		if (error)
500 			return error;
501 
502 		if (other_owners) {
503 			error = xagb_bitmap_set(&ra->crossed, agbno, 1);
504 			if (error)
505 				return error;
506 		}
507 
508 		if (xchk_should_terminate(ra->sc, &error))
509 			return error;
510 		agbno++;
511 	}
512 
513 	return 0;
514 }
515 
516 /*
517  * Map out all the non-AGFL OWN_AG space in this AG so that we can deduce
518  * which blocks belong to the AGFL.
519  *
520  * Compute the set of old AGFL blocks by subtracting from the list of OWN_AG
521  * blocks the list of blocks owned by all other OWN_AG metadata (bnobt, cntbt,
522  * rmapbt).  These are the old AGFL blocks, so return that list and the number
523  * of blocks we're actually going to put back on the AGFL.
524  */
525 STATIC int
526 xrep_agfl_collect_blocks(
527 	struct xfs_scrub	*sc,
528 	struct xfs_buf		*agf_bp,
529 	struct xagb_bitmap	*agfl_extents,
530 	xfs_agblock_t		*flcount)
531 {
532 	struct xrep_agfl	ra;
533 	struct xfs_mount	*mp = sc->mp;
534 	struct xfs_btree_cur	*cur;
535 	int			error;
536 
537 	ra.sc = sc;
538 	ra.freesp = agfl_extents;
539 	xagb_bitmap_init(&ra.agmetablocks);
540 	xagb_bitmap_init(&ra.crossed);
541 
542 	/* Find all space used by the free space btrees & rmapbt. */
543 	cur = xfs_rmapbt_init_cursor(mp, sc->tp, agf_bp, sc->sa.pag);
544 	error = xfs_rmap_query_all(cur, xrep_agfl_walk_rmap, &ra);
545 	xfs_btree_del_cursor(cur, error);
546 	if (error)
547 		goto out_bmp;
548 
549 	/* Find all blocks currently being used by the bnobt. */
550 	cur = xfs_bnobt_init_cursor(mp, sc->tp, agf_bp, sc->sa.pag);
551 	error = xagb_bitmap_set_btblocks(&ra.agmetablocks, cur);
552 	xfs_btree_del_cursor(cur, error);
553 	if (error)
554 		goto out_bmp;
555 
556 	/* Find all blocks currently being used by the cntbt. */
557 	cur = xfs_cntbt_init_cursor(mp, sc->tp, agf_bp, sc->sa.pag);
558 	error = xagb_bitmap_set_btblocks(&ra.agmetablocks, cur);
559 	xfs_btree_del_cursor(cur, error);
560 	if (error)
561 		goto out_bmp;
562 
563 	/*
564 	 * Drop the freesp meta blocks that are in use by btrees.
565 	 * The remaining blocks /should/ be AGFL blocks.
566 	 */
567 	error = xagb_bitmap_disunion(agfl_extents, &ra.agmetablocks);
568 	if (error)
569 		goto out_bmp;
570 
571 	/* Strike out the blocks that are cross-linked. */
572 	ra.rmap_cur = xfs_rmapbt_init_cursor(mp, sc->tp, agf_bp, sc->sa.pag);
573 	error = xagb_bitmap_walk(agfl_extents, xrep_agfl_check_extent, &ra);
574 	xfs_btree_del_cursor(ra.rmap_cur, error);
575 	if (error)
576 		goto out_bmp;
577 	error = xagb_bitmap_disunion(agfl_extents, &ra.crossed);
578 	if (error)
579 		goto out_bmp;
580 
581 	/*
582 	 * Calculate the new AGFL size.  If we found more blocks than fit in
583 	 * the AGFL we'll free them later.
584 	 */
585 	*flcount = min_t(uint64_t, xagb_bitmap_hweight(agfl_extents),
586 			 xfs_agfl_size(mp));
587 
588 out_bmp:
589 	xagb_bitmap_destroy(&ra.crossed);
590 	xagb_bitmap_destroy(&ra.agmetablocks);
591 	return error;
592 }
593 
594 /* Update the AGF and reset the in-core state. */
595 STATIC void
596 xrep_agfl_update_agf(
597 	struct xfs_scrub	*sc,
598 	struct xfs_buf		*agf_bp,
599 	xfs_agblock_t		flcount)
600 {
601 	struct xfs_agf		*agf = agf_bp->b_addr;
602 
603 	ASSERT(flcount <= xfs_agfl_size(sc->mp));
604 
605 	/* Trigger fdblocks recalculation */
606 	xfs_force_summary_recalc(sc->mp);
607 
608 	/* Update the AGF counters. */
609 	if (xfs_perag_initialised_agf(sc->sa.pag)) {
610 		sc->sa.pag->pagf_flcount = flcount;
611 		clear_bit(XFS_AGSTATE_AGFL_NEEDS_RESET,
612 				&sc->sa.pag->pag_opstate);
613 	}
614 	agf->agf_flfirst = cpu_to_be32(0);
615 	agf->agf_flcount = cpu_to_be32(flcount);
616 	if (flcount)
617 		agf->agf_fllast = cpu_to_be32(flcount - 1);
618 	else
619 		agf->agf_fllast = cpu_to_be32(xfs_agfl_size(sc->mp) - 1);
620 
621 	xfs_alloc_log_agf(sc->tp, agf_bp,
622 			XFS_AGF_FLFIRST | XFS_AGF_FLLAST | XFS_AGF_FLCOUNT);
623 }
624 
625 struct xrep_agfl_fill {
626 	struct xagb_bitmap	used_extents;
627 	struct xfs_scrub	*sc;
628 	__be32			*agfl_bno;
629 	xfs_agblock_t		flcount;
630 	unsigned int		fl_off;
631 };
632 
633 /* Fill the AGFL with whatever blocks are in this extent. */
634 static int
635 xrep_agfl_fill(
636 	uint32_t		start,
637 	uint32_t		len,
638 	void			*priv)
639 {
640 	struct xrep_agfl_fill	*af = priv;
641 	struct xfs_scrub	*sc = af->sc;
642 	xfs_agblock_t		agbno = start;
643 	int			error;
644 
645 	trace_xrep_agfl_insert(sc->sa.pag, agbno, len);
646 
647 	while (agbno < start + len && af->fl_off < af->flcount)
648 		af->agfl_bno[af->fl_off++] = cpu_to_be32(agbno++);
649 
650 	error = xagb_bitmap_set(&af->used_extents, start, agbno - 1);
651 	if (error)
652 		return error;
653 
654 	if (af->fl_off == af->flcount)
655 		return -ECANCELED;
656 
657 	return 0;
658 }
659 
660 /* Write out a totally new AGFL. */
661 STATIC int
662 xrep_agfl_init_header(
663 	struct xfs_scrub	*sc,
664 	struct xfs_buf		*agfl_bp,
665 	struct xagb_bitmap	*agfl_extents,
666 	xfs_agblock_t		flcount)
667 {
668 	struct xrep_agfl_fill	af = {
669 		.sc		= sc,
670 		.flcount	= flcount,
671 	};
672 	struct xfs_mount	*mp = sc->mp;
673 	struct xfs_agfl		*agfl;
674 	int			error;
675 
676 	ASSERT(flcount <= xfs_agfl_size(mp));
677 
678 	/*
679 	 * Start rewriting the header by setting the bno[] array to
680 	 * NULLAGBLOCK, then setting AGFL header fields.
681 	 */
682 	agfl = XFS_BUF_TO_AGFL(agfl_bp);
683 	memset(agfl, 0xFF, BBTOB(agfl_bp->b_length));
684 	agfl->agfl_magicnum = cpu_to_be32(XFS_AGFL_MAGIC);
685 	agfl->agfl_seqno = cpu_to_be32(sc->sa.pag->pag_agno);
686 	uuid_copy(&agfl->agfl_uuid, &mp->m_sb.sb_meta_uuid);
687 
688 	/*
689 	 * Fill the AGFL with the remaining blocks.  If agfl_extents has more
690 	 * blocks than fit in the AGFL, they will be freed in a subsequent
691 	 * step.
692 	 */
693 	xagb_bitmap_init(&af.used_extents);
694 	af.agfl_bno = xfs_buf_to_agfl_bno(agfl_bp),
695 	xagb_bitmap_walk(agfl_extents, xrep_agfl_fill, &af);
696 	error = xagb_bitmap_disunion(agfl_extents, &af.used_extents);
697 	if (error)
698 		return error;
699 
700 	/* Write new AGFL to disk. */
701 	xfs_trans_buf_set_type(sc->tp, agfl_bp, XFS_BLFT_AGFL_BUF);
702 	xfs_trans_log_buf(sc->tp, agfl_bp, 0, BBTOB(agfl_bp->b_length) - 1);
703 	xagb_bitmap_destroy(&af.used_extents);
704 	return 0;
705 }
706 
707 /* Repair the AGFL. */
708 int
709 xrep_agfl(
710 	struct xfs_scrub	*sc)
711 {
712 	struct xagb_bitmap	agfl_extents;
713 	struct xfs_mount	*mp = sc->mp;
714 	struct xfs_buf		*agf_bp;
715 	struct xfs_buf		*agfl_bp;
716 	xfs_agblock_t		flcount;
717 	int			error;
718 
719 	/* We require the rmapbt to rebuild anything. */
720 	if (!xfs_has_rmapbt(mp))
721 		return -EOPNOTSUPP;
722 
723 	xagb_bitmap_init(&agfl_extents);
724 
725 	/*
726 	 * Read the AGF so that we can query the rmapbt.  We hope that there's
727 	 * nothing wrong with the AGF, but all the AG header repair functions
728 	 * have this chicken-and-egg problem.
729 	 */
730 	error = xfs_alloc_read_agf(sc->sa.pag, sc->tp, 0, &agf_bp);
731 	if (error)
732 		return error;
733 
734 	/*
735 	 * Make sure we have the AGFL buffer, as scrub might have decided it
736 	 * was corrupt after xfs_alloc_read_agfl failed with -EFSCORRUPTED.
737 	 */
738 	error = xfs_trans_read_buf(mp, sc->tp, mp->m_ddev_targp,
739 			XFS_AG_DADDR(mp, sc->sa.pag->pag_agno,
740 						XFS_AGFL_DADDR(mp)),
741 			XFS_FSS_TO_BB(mp, 1), 0, &agfl_bp, NULL);
742 	if (error)
743 		return error;
744 	agfl_bp->b_ops = &xfs_agfl_buf_ops;
745 
746 	/* Gather all the extents we're going to put on the new AGFL. */
747 	error = xrep_agfl_collect_blocks(sc, agf_bp, &agfl_extents, &flcount);
748 	if (error)
749 		goto err;
750 
751 	/* Last chance to abort before we start committing fixes. */
752 	if (xchk_should_terminate(sc, &error))
753 		goto err;
754 
755 	/*
756 	 * Update AGF and AGFL.  We reset the global free block counter when
757 	 * we adjust the AGF flcount (which can fail) so avoid updating any
758 	 * buffers until we know that part works.
759 	 */
760 	xrep_agfl_update_agf(sc, agf_bp, flcount);
761 	error = xrep_agfl_init_header(sc, agfl_bp, &agfl_extents, flcount);
762 	if (error)
763 		goto err;
764 
765 	/*
766 	 * Ok, the AGFL should be ready to go now.  Roll the transaction to
767 	 * make the new AGFL permanent before we start using it to return
768 	 * freespace overflow to the freespace btrees.
769 	 */
770 	sc->sa.agf_bp = agf_bp;
771 	error = xrep_roll_ag_trans(sc);
772 	if (error)
773 		goto err;
774 
775 	/* Dump any AGFL overflow. */
776 	error = xrep_reap_agblocks(sc, &agfl_extents, &XFS_RMAP_OINFO_AG,
777 			XFS_AG_RESV_AGFL);
778 	if (error)
779 		goto err;
780 
781 err:
782 	xagb_bitmap_destroy(&agfl_extents);
783 	return error;
784 }
785 
786 /* AGI */
787 
788 /*
789  * Offset within the xrep_find_ag_btree array for each btree type.  Avoid the
790  * XFS_BTNUM_ names here to avoid creating a sparse array.
791  */
792 enum {
793 	XREP_AGI_INOBT = 0,
794 	XREP_AGI_FINOBT,
795 	XREP_AGI_END,
796 	XREP_AGI_MAX
797 };
798 
799 /*
800  * Given the inode btree roots described by *fab, find the roots, check them
801  * for sanity, and pass the root data back out via *fab.
802  */
803 STATIC int
804 xrep_agi_find_btrees(
805 	struct xfs_scrub		*sc,
806 	struct xrep_find_ag_btree	*fab)
807 {
808 	struct xfs_buf			*agf_bp;
809 	struct xfs_mount		*mp = sc->mp;
810 	int				error;
811 
812 	/* Read the AGF. */
813 	error = xfs_alloc_read_agf(sc->sa.pag, sc->tp, 0, &agf_bp);
814 	if (error)
815 		return error;
816 
817 	/* Find the btree roots. */
818 	error = xrep_find_ag_btree_roots(sc, agf_bp, fab, NULL);
819 	if (error)
820 		return error;
821 
822 	/* We must find the inobt root. */
823 	if (!xrep_check_btree_root(sc, &fab[XREP_AGI_INOBT]))
824 		return -EFSCORRUPTED;
825 
826 	/* We must find the finobt root if that feature is enabled. */
827 	if (xfs_has_finobt(mp) &&
828 	    !xrep_check_btree_root(sc, &fab[XREP_AGI_FINOBT]))
829 		return -EFSCORRUPTED;
830 
831 	return 0;
832 }
833 
834 /*
835  * Reinitialize the AGI header, making an in-core copy of the old contents so
836  * that we know which in-core state needs to be reinitialized.
837  */
838 STATIC void
839 xrep_agi_init_header(
840 	struct xfs_scrub	*sc,
841 	struct xfs_buf		*agi_bp,
842 	struct xfs_agi		*old_agi)
843 {
844 	struct xfs_agi		*agi = agi_bp->b_addr;
845 	struct xfs_perag	*pag = sc->sa.pag;
846 	struct xfs_mount	*mp = sc->mp;
847 
848 	memcpy(old_agi, agi, sizeof(*old_agi));
849 	memset(agi, 0, BBTOB(agi_bp->b_length));
850 	agi->agi_magicnum = cpu_to_be32(XFS_AGI_MAGIC);
851 	agi->agi_versionnum = cpu_to_be32(XFS_AGI_VERSION);
852 	agi->agi_seqno = cpu_to_be32(pag->pag_agno);
853 	agi->agi_length = cpu_to_be32(pag->block_count);
854 	agi->agi_newino = cpu_to_be32(NULLAGINO);
855 	agi->agi_dirino = cpu_to_be32(NULLAGINO);
856 	if (xfs_has_crc(mp))
857 		uuid_copy(&agi->agi_uuid, &mp->m_sb.sb_meta_uuid);
858 
859 	/* We don't know how to fix the unlinked list yet. */
860 	memcpy(&agi->agi_unlinked, &old_agi->agi_unlinked,
861 			sizeof(agi->agi_unlinked));
862 
863 	/* Mark the incore AGF data stale until we're done fixing things. */
864 	ASSERT(xfs_perag_initialised_agi(pag));
865 	clear_bit(XFS_AGSTATE_AGI_INIT, &pag->pag_opstate);
866 }
867 
868 /* Set btree root information in an AGI. */
869 STATIC void
870 xrep_agi_set_roots(
871 	struct xfs_scrub		*sc,
872 	struct xfs_agi			*agi,
873 	struct xrep_find_ag_btree	*fab)
874 {
875 	agi->agi_root = cpu_to_be32(fab[XREP_AGI_INOBT].root);
876 	agi->agi_level = cpu_to_be32(fab[XREP_AGI_INOBT].height);
877 
878 	if (xfs_has_finobt(sc->mp)) {
879 		agi->agi_free_root = cpu_to_be32(fab[XREP_AGI_FINOBT].root);
880 		agi->agi_free_level = cpu_to_be32(fab[XREP_AGI_FINOBT].height);
881 	}
882 }
883 
884 /* Update the AGI counters. */
885 STATIC int
886 xrep_agi_calc_from_btrees(
887 	struct xfs_scrub	*sc,
888 	struct xfs_buf		*agi_bp)
889 {
890 	struct xfs_btree_cur	*cur;
891 	struct xfs_agi		*agi = agi_bp->b_addr;
892 	struct xfs_mount	*mp = sc->mp;
893 	xfs_agino_t		count;
894 	xfs_agino_t		freecount;
895 	int			error;
896 
897 	cur = xfs_inobt_init_cursor(sc->sa.pag, sc->tp, agi_bp);
898 	error = xfs_ialloc_count_inodes(cur, &count, &freecount);
899 	if (error)
900 		goto err;
901 	if (xfs_has_inobtcounts(mp)) {
902 		xfs_agblock_t	blocks;
903 
904 		error = xfs_btree_count_blocks(cur, &blocks);
905 		if (error)
906 			goto err;
907 		agi->agi_iblocks = cpu_to_be32(blocks);
908 	}
909 	xfs_btree_del_cursor(cur, error);
910 
911 	agi->agi_count = cpu_to_be32(count);
912 	agi->agi_freecount = cpu_to_be32(freecount);
913 
914 	if (xfs_has_finobt(mp) && xfs_has_inobtcounts(mp)) {
915 		xfs_agblock_t	blocks;
916 
917 		cur = xfs_finobt_init_cursor(sc->sa.pag, sc->tp, agi_bp);
918 		error = xfs_btree_count_blocks(cur, &blocks);
919 		if (error)
920 			goto err;
921 		xfs_btree_del_cursor(cur, error);
922 		agi->agi_fblocks = cpu_to_be32(blocks);
923 	}
924 
925 	return 0;
926 err:
927 	xfs_btree_del_cursor(cur, error);
928 	return error;
929 }
930 
931 /* Trigger reinitialization of the in-core data. */
932 STATIC int
933 xrep_agi_commit_new(
934 	struct xfs_scrub	*sc,
935 	struct xfs_buf		*agi_bp)
936 {
937 	struct xfs_perag	*pag;
938 	struct xfs_agi		*agi = agi_bp->b_addr;
939 
940 	/* Trigger inode count recalculation */
941 	xfs_force_summary_recalc(sc->mp);
942 
943 	/* Write this to disk. */
944 	xfs_trans_buf_set_type(sc->tp, agi_bp, XFS_BLFT_AGI_BUF);
945 	xfs_trans_log_buf(sc->tp, agi_bp, 0, BBTOB(agi_bp->b_length) - 1);
946 
947 	/* Now reinitialize the in-core counters if necessary. */
948 	pag = sc->sa.pag;
949 	pag->pagi_count = be32_to_cpu(agi->agi_count);
950 	pag->pagi_freecount = be32_to_cpu(agi->agi_freecount);
951 	set_bit(XFS_AGSTATE_AGI_INIT, &pag->pag_opstate);
952 
953 	return xrep_roll_ag_trans(sc);
954 }
955 
956 /* Repair the AGI. */
957 int
958 xrep_agi(
959 	struct xfs_scrub		*sc)
960 {
961 	struct xrep_find_ag_btree	fab[XREP_AGI_MAX] = {
962 		[XREP_AGI_INOBT] = {
963 			.rmap_owner = XFS_RMAP_OWN_INOBT,
964 			.buf_ops = &xfs_inobt_buf_ops,
965 			.maxlevels = M_IGEO(sc->mp)->inobt_maxlevels,
966 		},
967 		[XREP_AGI_FINOBT] = {
968 			.rmap_owner = XFS_RMAP_OWN_INOBT,
969 			.buf_ops = &xfs_finobt_buf_ops,
970 			.maxlevels = M_IGEO(sc->mp)->inobt_maxlevels,
971 		},
972 		[XREP_AGI_END] = {
973 			.buf_ops = NULL
974 		},
975 	};
976 	struct xfs_agi			old_agi;
977 	struct xfs_mount		*mp = sc->mp;
978 	struct xfs_buf			*agi_bp;
979 	struct xfs_agi			*agi;
980 	int				error;
981 
982 	/* We require the rmapbt to rebuild anything. */
983 	if (!xfs_has_rmapbt(mp))
984 		return -EOPNOTSUPP;
985 
986 	/*
987 	 * Make sure we have the AGI buffer, as scrub might have decided it
988 	 * was corrupt after xfs_ialloc_read_agi failed with -EFSCORRUPTED.
989 	 */
990 	error = xfs_trans_read_buf(mp, sc->tp, mp->m_ddev_targp,
991 			XFS_AG_DADDR(mp, sc->sa.pag->pag_agno,
992 						XFS_AGI_DADDR(mp)),
993 			XFS_FSS_TO_BB(mp, 1), 0, &agi_bp, NULL);
994 	if (error)
995 		return error;
996 	agi_bp->b_ops = &xfs_agi_buf_ops;
997 	agi = agi_bp->b_addr;
998 
999 	/* Find the AGI btree roots. */
1000 	error = xrep_agi_find_btrees(sc, fab);
1001 	if (error)
1002 		return error;
1003 
1004 	/* Last chance to abort before we start committing fixes. */
1005 	if (xchk_should_terminate(sc, &error))
1006 		return error;
1007 
1008 	/* Start rewriting the header and implant the btrees we found. */
1009 	xrep_agi_init_header(sc, agi_bp, &old_agi);
1010 	xrep_agi_set_roots(sc, agi, fab);
1011 	error = xrep_agi_calc_from_btrees(sc, agi_bp);
1012 	if (error)
1013 		goto out_revert;
1014 
1015 	/* Reinitialize in-core state. */
1016 	return xrep_agi_commit_new(sc, agi_bp);
1017 
1018 out_revert:
1019 	/* Mark the incore AGI state stale and revert the AGI. */
1020 	clear_bit(XFS_AGSTATE_AGI_INIT, &sc->sa.pag->pag_opstate);
1021 	memcpy(agi, &old_agi, sizeof(old_agi));
1022 	return error;
1023 }
1024