xref: /linux/fs/bcachefs/backpointers.c (revision 4abcd80f23357808b0444d261ed08e5a77dbaa9a)
1 // SPDX-License-Identifier: GPL-2.0
2 #include "bcachefs.h"
3 #include "bbpos.h"
4 #include "alloc_background.h"
5 #include "backpointers.h"
6 #include "bkey_buf.h"
7 #include "btree_cache.h"
8 #include "btree_update.h"
9 #include "btree_update_interior.h"
10 #include "btree_write_buffer.h"
11 #include "checksum.h"
12 #include "disk_accounting.h"
13 #include "error.h"
14 
15 #include <linux/mm.h>
16 
extent_matches_bp(struct bch_fs * c,enum btree_id btree_id,unsigned level,struct bkey_s_c k,struct bpos bucket,struct bch_backpointer bp)17 static bool extent_matches_bp(struct bch_fs *c,
18 			      enum btree_id btree_id, unsigned level,
19 			      struct bkey_s_c k,
20 			      struct bpos bucket,
21 			      struct bch_backpointer bp)
22 {
23 	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k);
24 	const union bch_extent_entry *entry;
25 	struct extent_ptr_decoded p;
26 
27 	rcu_read_lock();
28 	bkey_for_each_ptr_decode(k.k, ptrs, p, entry) {
29 		struct bpos bucket2;
30 		struct bch_backpointer bp2;
31 
32 		if (p.ptr.cached)
33 			continue;
34 
35 		struct bch_dev *ca = bch2_dev_rcu(c, p.ptr.dev);
36 		if (!ca)
37 			continue;
38 
39 		bch2_extent_ptr_to_bp(c, ca, btree_id, level, k, p, entry, &bucket2, &bp2);
40 		if (bpos_eq(bucket, bucket2) &&
41 		    !memcmp(&bp, &bp2, sizeof(bp))) {
42 			rcu_read_unlock();
43 			return true;
44 		}
45 	}
46 	rcu_read_unlock();
47 
48 	return false;
49 }
50 
bch2_backpointer_validate(struct bch_fs * c,struct bkey_s_c k,enum bch_validate_flags flags)51 int bch2_backpointer_validate(struct bch_fs *c, struct bkey_s_c k,
52 			      enum bch_validate_flags flags)
53 {
54 	struct bkey_s_c_backpointer bp = bkey_s_c_to_backpointer(k);
55 	int ret = 0;
56 
57 	bkey_fsck_err_on(bp.v->level > BTREE_MAX_DEPTH,
58 			 c, backpointer_level_bad,
59 			 "backpointer level bad: %u >= %u",
60 			 bp.v->level, BTREE_MAX_DEPTH);
61 
62 	rcu_read_lock();
63 	struct bch_dev *ca = bch2_dev_rcu_noerror(c, bp.k->p.inode);
64 	if (!ca) {
65 		/* these will be caught by fsck */
66 		rcu_read_unlock();
67 		return 0;
68 	}
69 
70 	struct bpos bucket = bp_pos_to_bucket(ca, bp.k->p);
71 	struct bpos bp_pos = bucket_pos_to_bp_noerror(ca, bucket, bp.v->bucket_offset);
72 	rcu_read_unlock();
73 
74 	bkey_fsck_err_on((bp.v->bucket_offset >> MAX_EXTENT_COMPRESS_RATIO_SHIFT) >= ca->mi.bucket_size ||
75 			 !bpos_eq(bp.k->p, bp_pos),
76 			 c, backpointer_bucket_offset_wrong,
77 			 "backpointer bucket_offset wrong");
78 fsck_err:
79 	return ret;
80 }
81 
bch2_backpointer_to_text(struct printbuf * out,const struct bch_backpointer * bp)82 void bch2_backpointer_to_text(struct printbuf *out, const struct bch_backpointer *bp)
83 {
84 	prt_printf(out, "btree=%s l=%u offset=%llu:%u len=%u pos=",
85 	       bch2_btree_id_str(bp->btree_id),
86 	       bp->level,
87 	       (u64) (bp->bucket_offset >> MAX_EXTENT_COMPRESS_RATIO_SHIFT),
88 	       (u32) bp->bucket_offset & ~(~0U << MAX_EXTENT_COMPRESS_RATIO_SHIFT),
89 	       bp->bucket_len);
90 	bch2_bpos_to_text(out, bp->pos);
91 }
92 
bch2_backpointer_k_to_text(struct printbuf * out,struct bch_fs * c,struct bkey_s_c k)93 void bch2_backpointer_k_to_text(struct printbuf *out, struct bch_fs *c, struct bkey_s_c k)
94 {
95 	rcu_read_lock();
96 	struct bch_dev *ca = bch2_dev_rcu_noerror(c, k.k->p.inode);
97 	if (ca) {
98 		struct bpos bucket = bp_pos_to_bucket(ca, k.k->p);
99 		rcu_read_unlock();
100 		prt_str(out, "bucket=");
101 		bch2_bpos_to_text(out, bucket);
102 		prt_str(out, " ");
103 	} else {
104 		rcu_read_unlock();
105 	}
106 
107 	bch2_backpointer_to_text(out, bkey_s_c_to_backpointer(k).v);
108 }
109 
bch2_backpointer_swab(struct bkey_s k)110 void bch2_backpointer_swab(struct bkey_s k)
111 {
112 	struct bkey_s_backpointer bp = bkey_s_to_backpointer(k);
113 
114 	bp.v->bucket_offset	= swab40(bp.v->bucket_offset);
115 	bp.v->bucket_len	= swab32(bp.v->bucket_len);
116 	bch2_bpos_swab(&bp.v->pos);
117 }
118 
backpointer_mod_err(struct btree_trans * trans,struct bch_backpointer bp,struct bkey_s_c bp_k,struct bkey_s_c orig_k,bool insert)119 static noinline int backpointer_mod_err(struct btree_trans *trans,
120 					struct bch_backpointer bp,
121 					struct bkey_s_c bp_k,
122 					struct bkey_s_c orig_k,
123 					bool insert)
124 {
125 	struct bch_fs *c = trans->c;
126 	struct printbuf buf = PRINTBUF;
127 
128 	if (insert) {
129 		prt_printf(&buf, "existing backpointer found when inserting ");
130 		bch2_backpointer_to_text(&buf, &bp);
131 		prt_newline(&buf);
132 		printbuf_indent_add(&buf, 2);
133 
134 		prt_printf(&buf, "found ");
135 		bch2_bkey_val_to_text(&buf, c, bp_k);
136 		prt_newline(&buf);
137 
138 		prt_printf(&buf, "for ");
139 		bch2_bkey_val_to_text(&buf, c, orig_k);
140 
141 		bch_err(c, "%s", buf.buf);
142 	} else if (c->curr_recovery_pass > BCH_RECOVERY_PASS_check_extents_to_backpointers) {
143 		prt_printf(&buf, "backpointer not found when deleting\n");
144 		printbuf_indent_add(&buf, 2);
145 
146 		prt_printf(&buf, "searching for ");
147 		bch2_backpointer_to_text(&buf, &bp);
148 		prt_newline(&buf);
149 
150 		prt_printf(&buf, "got ");
151 		bch2_bkey_val_to_text(&buf, c, bp_k);
152 		prt_newline(&buf);
153 
154 		prt_printf(&buf, "for ");
155 		bch2_bkey_val_to_text(&buf, c, orig_k);
156 
157 		bch_err(c, "%s", buf.buf);
158 	}
159 
160 	printbuf_exit(&buf);
161 
162 	if (c->curr_recovery_pass > BCH_RECOVERY_PASS_check_extents_to_backpointers) {
163 		return bch2_inconsistent_error(c) ? BCH_ERR_erofs_unfixed_errors : 0;
164 	} else {
165 		return 0;
166 	}
167 }
168 
bch2_bucket_backpointer_mod_nowritebuffer(struct btree_trans * trans,struct bch_dev * ca,struct bpos bucket,struct bch_backpointer bp,struct bkey_s_c orig_k,bool insert)169 int bch2_bucket_backpointer_mod_nowritebuffer(struct btree_trans *trans,
170 				struct bch_dev *ca,
171 				struct bpos bucket,
172 				struct bch_backpointer bp,
173 				struct bkey_s_c orig_k,
174 				bool insert)
175 {
176 	struct btree_iter bp_iter;
177 	struct bkey_s_c k;
178 	struct bkey_i_backpointer *bp_k;
179 	int ret;
180 
181 	bp_k = bch2_trans_kmalloc_nomemzero(trans, sizeof(struct bkey_i_backpointer));
182 	ret = PTR_ERR_OR_ZERO(bp_k);
183 	if (ret)
184 		return ret;
185 
186 	bkey_backpointer_init(&bp_k->k_i);
187 	bp_k->k.p = bucket_pos_to_bp(ca, bucket, bp.bucket_offset);
188 	bp_k->v = bp;
189 
190 	if (!insert) {
191 		bp_k->k.type = KEY_TYPE_deleted;
192 		set_bkey_val_u64s(&bp_k->k, 0);
193 	}
194 
195 	k = bch2_bkey_get_iter(trans, &bp_iter, BTREE_ID_backpointers,
196 			       bp_k->k.p,
197 			       BTREE_ITER_intent|
198 			       BTREE_ITER_slots|
199 			       BTREE_ITER_with_updates);
200 	ret = bkey_err(k);
201 	if (ret)
202 		goto err;
203 
204 	if (insert
205 	    ? k.k->type
206 	    : (k.k->type != KEY_TYPE_backpointer ||
207 	       memcmp(bkey_s_c_to_backpointer(k).v, &bp, sizeof(bp)))) {
208 		ret = backpointer_mod_err(trans, bp, k, orig_k, insert);
209 		if (ret)
210 			goto err;
211 	}
212 
213 	ret = bch2_trans_update(trans, &bp_iter, &bp_k->k_i, 0);
214 err:
215 	bch2_trans_iter_exit(trans, &bp_iter);
216 	return ret;
217 }
218 
219 /*
220  * Find the next backpointer >= *bp_offset:
221  */
bch2_get_next_backpointer(struct btree_trans * trans,struct bch_dev * ca,struct bpos bucket,int gen,struct bpos * bp_pos,struct bch_backpointer * bp,unsigned iter_flags)222 int bch2_get_next_backpointer(struct btree_trans *trans,
223 			      struct bch_dev *ca,
224 			      struct bpos bucket, int gen,
225 			      struct bpos *bp_pos,
226 			      struct bch_backpointer *bp,
227 			      unsigned iter_flags)
228 {
229 	struct bpos bp_end_pos = bucket_pos_to_bp(ca, bpos_nosnap_successor(bucket), 0);
230 	struct btree_iter alloc_iter = { NULL }, bp_iter = { NULL };
231 	struct bkey_s_c k;
232 	int ret = 0;
233 
234 	if (bpos_ge(*bp_pos, bp_end_pos))
235 		goto done;
236 
237 	if (gen >= 0) {
238 		k = bch2_bkey_get_iter(trans, &alloc_iter, BTREE_ID_alloc,
239 				       bucket, BTREE_ITER_cached|iter_flags);
240 		ret = bkey_err(k);
241 		if (ret)
242 			goto out;
243 
244 		if (k.k->type != KEY_TYPE_alloc_v4 ||
245 		    bkey_s_c_to_alloc_v4(k).v->gen != gen)
246 			goto done;
247 	}
248 
249 	*bp_pos = bpos_max(*bp_pos, bucket_pos_to_bp(ca, bucket, 0));
250 
251 	for_each_btree_key_norestart(trans, bp_iter, BTREE_ID_backpointers,
252 				     *bp_pos, iter_flags, k, ret) {
253 		if (bpos_ge(k.k->p, bp_end_pos))
254 			break;
255 
256 		*bp_pos = k.k->p;
257 		*bp = *bkey_s_c_to_backpointer(k).v;
258 		goto out;
259 	}
260 done:
261 	*bp_pos = SPOS_MAX;
262 out:
263 	bch2_trans_iter_exit(trans, &bp_iter);
264 	bch2_trans_iter_exit(trans, &alloc_iter);
265 	return ret;
266 }
267 
backpointer_not_found(struct btree_trans * trans,struct bpos bp_pos,struct bch_backpointer bp,struct bkey_s_c k)268 static void backpointer_not_found(struct btree_trans *trans,
269 				  struct bpos bp_pos,
270 				  struct bch_backpointer bp,
271 				  struct bkey_s_c k)
272 {
273 	struct bch_fs *c = trans->c;
274 	struct printbuf buf = PRINTBUF;
275 
276 	/*
277 	 * If we're using the btree write buffer, the backpointer we were
278 	 * looking at may have already been deleted - failure to find what it
279 	 * pointed to is not an error:
280 	 */
281 	if (likely(!bch2_backpointers_no_use_write_buffer))
282 		return;
283 
284 	struct bpos bucket;
285 	if (!bp_pos_to_bucket_nodev(c, bp_pos, &bucket))
286 		return;
287 
288 	prt_printf(&buf, "backpointer doesn't match %s it points to:\n  ",
289 		   bp.level ? "btree node" : "extent");
290 	prt_printf(&buf, "bucket: ");
291 	bch2_bpos_to_text(&buf, bucket);
292 	prt_printf(&buf, "\n  ");
293 
294 	prt_printf(&buf, "backpointer pos: ");
295 	bch2_bpos_to_text(&buf, bp_pos);
296 	prt_printf(&buf, "\n  ");
297 
298 	bch2_backpointer_to_text(&buf, &bp);
299 	prt_printf(&buf, "\n  ");
300 	bch2_bkey_val_to_text(&buf, c, k);
301 	if (c->curr_recovery_pass >= BCH_RECOVERY_PASS_check_extents_to_backpointers)
302 		bch_err_ratelimited(c, "%s", buf.buf);
303 	else
304 		bch2_trans_inconsistent(trans, "%s", buf.buf);
305 
306 	printbuf_exit(&buf);
307 }
308 
bch2_backpointer_get_key(struct btree_trans * trans,struct btree_iter * iter,struct bpos bp_pos,struct bch_backpointer bp,unsigned iter_flags)309 struct bkey_s_c bch2_backpointer_get_key(struct btree_trans *trans,
310 					 struct btree_iter *iter,
311 					 struct bpos bp_pos,
312 					 struct bch_backpointer bp,
313 					 unsigned iter_flags)
314 {
315 	if (likely(!bp.level)) {
316 		struct bch_fs *c = trans->c;
317 
318 		struct bpos bucket;
319 		if (!bp_pos_to_bucket_nodev(c, bp_pos, &bucket))
320 			return bkey_s_c_err(-EIO);
321 
322 		bch2_trans_node_iter_init(trans, iter,
323 					  bp.btree_id,
324 					  bp.pos,
325 					  0, 0,
326 					  iter_flags);
327 		struct bkey_s_c k = bch2_btree_iter_peek_slot(iter);
328 		if (bkey_err(k)) {
329 			bch2_trans_iter_exit(trans, iter);
330 			return k;
331 		}
332 
333 		if (k.k && extent_matches_bp(c, bp.btree_id, bp.level, k, bucket, bp))
334 			return k;
335 
336 		bch2_trans_iter_exit(trans, iter);
337 		backpointer_not_found(trans, bp_pos, bp, k);
338 		return bkey_s_c_null;
339 	} else {
340 		struct btree *b = bch2_backpointer_get_node(trans, iter, bp_pos, bp);
341 
342 		if (IS_ERR_OR_NULL(b)) {
343 			bch2_trans_iter_exit(trans, iter);
344 			return IS_ERR(b) ? bkey_s_c_err(PTR_ERR(b)) : bkey_s_c_null;
345 		}
346 		return bkey_i_to_s_c(&b->key);
347 	}
348 }
349 
bch2_backpointer_get_node(struct btree_trans * trans,struct btree_iter * iter,struct bpos bp_pos,struct bch_backpointer bp)350 struct btree *bch2_backpointer_get_node(struct btree_trans *trans,
351 					struct btree_iter *iter,
352 					struct bpos bp_pos,
353 					struct bch_backpointer bp)
354 {
355 	struct bch_fs *c = trans->c;
356 
357 	BUG_ON(!bp.level);
358 
359 	struct bpos bucket;
360 	if (!bp_pos_to_bucket_nodev(c, bp_pos, &bucket))
361 		return ERR_PTR(-EIO);
362 
363 	bch2_trans_node_iter_init(trans, iter,
364 				  bp.btree_id,
365 				  bp.pos,
366 				  0,
367 				  bp.level - 1,
368 				  0);
369 	struct btree *b = bch2_btree_iter_peek_node(iter);
370 	if (IS_ERR_OR_NULL(b))
371 		goto err;
372 
373 	BUG_ON(b->c.level != bp.level - 1);
374 
375 	if (extent_matches_bp(c, bp.btree_id, bp.level,
376 			      bkey_i_to_s_c(&b->key),
377 			      bucket, bp))
378 		return b;
379 
380 	if (btree_node_will_make_reachable(b)) {
381 		b = ERR_PTR(-BCH_ERR_backpointer_to_overwritten_btree_node);
382 	} else {
383 		backpointer_not_found(trans, bp_pos, bp, bkey_i_to_s_c(&b->key));
384 		b = NULL;
385 	}
386 err:
387 	bch2_trans_iter_exit(trans, iter);
388 	return b;
389 }
390 
bch2_check_btree_backpointer(struct btree_trans * trans,struct btree_iter * bp_iter,struct bkey_s_c k)391 static int bch2_check_btree_backpointer(struct btree_trans *trans, struct btree_iter *bp_iter,
392 					struct bkey_s_c k)
393 {
394 	struct bch_fs *c = trans->c;
395 	struct btree_iter alloc_iter = { NULL };
396 	struct bkey_s_c alloc_k;
397 	struct printbuf buf = PRINTBUF;
398 	int ret = 0;
399 
400 	struct bpos bucket;
401 	if (!bp_pos_to_bucket_nodev_noerror(c, k.k->p, &bucket)) {
402 		if (fsck_err(trans, backpointer_to_missing_device,
403 			     "backpointer for missing device:\n%s",
404 			     (bch2_bkey_val_to_text(&buf, c, k), buf.buf)))
405 			ret = bch2_btree_delete_at(trans, bp_iter, 0);
406 		goto out;
407 	}
408 
409 	alloc_k = bch2_bkey_get_iter(trans, &alloc_iter, BTREE_ID_alloc, bucket, 0);
410 	ret = bkey_err(alloc_k);
411 	if (ret)
412 		goto out;
413 
414 	if (fsck_err_on(alloc_k.k->type != KEY_TYPE_alloc_v4,
415 			trans, backpointer_to_missing_alloc,
416 			"backpointer for nonexistent alloc key: %llu:%llu:0\n%s",
417 			alloc_iter.pos.inode, alloc_iter.pos.offset,
418 			(bch2_bkey_val_to_text(&buf, c, k), buf.buf))) {
419 		ret = bch2_btree_delete_at(trans, bp_iter, 0);
420 		goto out;
421 	}
422 out:
423 fsck_err:
424 	bch2_trans_iter_exit(trans, &alloc_iter);
425 	printbuf_exit(&buf);
426 	return ret;
427 }
428 
429 /* verify that every backpointer has a corresponding alloc key */
bch2_check_btree_backpointers(struct bch_fs * c)430 int bch2_check_btree_backpointers(struct bch_fs *c)
431 {
432 	int ret = bch2_trans_run(c,
433 		for_each_btree_key_commit(trans, iter,
434 			BTREE_ID_backpointers, POS_MIN, 0, k,
435 			NULL, NULL, BCH_TRANS_COMMIT_no_enospc,
436 		  bch2_check_btree_backpointer(trans, &iter, k)));
437 	bch_err_fn(c, ret);
438 	return ret;
439 }
440 
441 struct extents_to_bp_state {
442 	struct bpos	bucket_start;
443 	struct bpos	bucket_end;
444 	struct bkey_buf last_flushed;
445 };
446 
drop_dev_and_update(struct btree_trans * trans,enum btree_id btree,struct bkey_s_c extent,unsigned dev)447 static int drop_dev_and_update(struct btree_trans *trans, enum btree_id btree,
448 			       struct bkey_s_c extent, unsigned dev)
449 {
450 	struct bkey_i *n = bch2_bkey_make_mut_noupdate(trans, extent);
451 	int ret = PTR_ERR_OR_ZERO(n);
452 	if (ret)
453 		return ret;
454 
455 	bch2_bkey_drop_device(bkey_i_to_s(n), dev);
456 	return bch2_btree_insert_trans(trans, btree, n, 0);
457 }
458 
check_extent_checksum(struct btree_trans * trans,enum btree_id btree,struct bkey_s_c extent,enum btree_id o_btree,struct bkey_s_c extent2,unsigned dev)459 static int check_extent_checksum(struct btree_trans *trans,
460 				 enum btree_id btree, struct bkey_s_c extent,
461 				 enum btree_id o_btree, struct bkey_s_c extent2, unsigned dev)
462 {
463 	struct bch_fs *c = trans->c;
464 	struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(extent);
465 	const union bch_extent_entry *entry;
466 	struct extent_ptr_decoded p;
467 	struct printbuf buf = PRINTBUF;
468 	void *data_buf = NULL;
469 	struct bio *bio = NULL;
470 	size_t bytes;
471 	int ret = 0;
472 
473 	if (bkey_is_btree_ptr(extent.k))
474 		return false;
475 
476 	bkey_for_each_ptr_decode(extent.k, ptrs, p, entry)
477 		if (p.ptr.dev == dev)
478 			goto found;
479 	BUG();
480 found:
481 	if (!p.crc.csum_type)
482 		return false;
483 
484 	bytes = p.crc.compressed_size << 9;
485 
486 	struct bch_dev *ca = bch2_dev_get_ioref(c, dev, READ);
487 	if (!ca)
488 		return false;
489 
490 	data_buf = kvmalloc(bytes, GFP_KERNEL);
491 	if (!data_buf) {
492 		ret = -ENOMEM;
493 		goto err;
494 	}
495 
496 	bio = bio_alloc(ca->disk_sb.bdev, buf_pages(data_buf, bytes), REQ_OP_READ, GFP_KERNEL);
497 	bio->bi_iter.bi_sector = p.ptr.offset;
498 	bch2_bio_map(bio, data_buf, bytes);
499 	ret = submit_bio_wait(bio);
500 	if (ret)
501 		goto err;
502 
503 	prt_str(&buf, "extents pointing to same space, but first extent checksum bad:");
504 	prt_printf(&buf, "\n  %s ", bch2_btree_id_str(btree));
505 	bch2_bkey_val_to_text(&buf, c, extent);
506 	prt_printf(&buf, "\n  %s ", bch2_btree_id_str(o_btree));
507 	bch2_bkey_val_to_text(&buf, c, extent2);
508 
509 	struct nonce nonce = extent_nonce(extent.k->bversion, p.crc);
510 	struct bch_csum csum = bch2_checksum(c, p.crc.csum_type, nonce, data_buf, bytes);
511 	if (fsck_err_on(bch2_crc_cmp(csum, p.crc.csum),
512 			trans, dup_backpointer_to_bad_csum_extent,
513 			"%s", buf.buf))
514 		ret = drop_dev_and_update(trans, btree, extent, dev) ?: 1;
515 fsck_err:
516 err:
517 	if (bio)
518 		bio_put(bio);
519 	kvfree(data_buf);
520 	percpu_ref_put(&ca->io_ref);
521 	printbuf_exit(&buf);
522 	return ret;
523 }
524 
check_bp_exists(struct btree_trans * trans,struct extents_to_bp_state * s,struct bpos bucket,struct bch_backpointer bp,struct bkey_s_c orig_k)525 static int check_bp_exists(struct btree_trans *trans,
526 			   struct extents_to_bp_state *s,
527 			   struct bpos bucket,
528 			   struct bch_backpointer bp,
529 			   struct bkey_s_c orig_k)
530 {
531 	struct bch_fs *c = trans->c;
532 	struct btree_iter bp_iter = {};
533 	struct btree_iter other_extent_iter = {};
534 	struct printbuf buf = PRINTBUF;
535 	struct bkey_s_c bp_k;
536 	int ret = 0;
537 
538 	struct bch_dev *ca = bch2_dev_bucket_tryget(c, bucket);
539 	if (!ca) {
540 		prt_str(&buf, "extent for nonexistent device:bucket ");
541 		bch2_bpos_to_text(&buf, bucket);
542 		prt_str(&buf, "\n  ");
543 		bch2_bkey_val_to_text(&buf, c, orig_k);
544 		bch_err(c, "%s", buf.buf);
545 		ret = -BCH_ERR_fsck_repair_unimplemented;
546 		goto err;
547 	}
548 
549 	if (bpos_lt(bucket, s->bucket_start) ||
550 	    bpos_gt(bucket, s->bucket_end))
551 		goto out;
552 
553 	bp_k = bch2_bkey_get_iter(trans, &bp_iter, BTREE_ID_backpointers,
554 				  bucket_pos_to_bp(ca, bucket, bp.bucket_offset),
555 				  0);
556 	ret = bkey_err(bp_k);
557 	if (ret)
558 		goto err;
559 
560 	if (bp_k.k->type != KEY_TYPE_backpointer ||
561 	    memcmp(bkey_s_c_to_backpointer(bp_k).v, &bp, sizeof(bp))) {
562 		ret = bch2_btree_write_buffer_maybe_flush(trans, orig_k, &s->last_flushed);
563 		if (ret)
564 			goto err;
565 
566 		goto check_existing_bp;
567 	}
568 out:
569 err:
570 fsck_err:
571 	bch2_trans_iter_exit(trans, &other_extent_iter);
572 	bch2_trans_iter_exit(trans, &bp_iter);
573 	bch2_dev_put(ca);
574 	printbuf_exit(&buf);
575 	return ret;
576 check_existing_bp:
577 	/* Do we have a backpointer for a different extent? */
578 	if (bp_k.k->type != KEY_TYPE_backpointer)
579 		goto missing;
580 
581 	struct bch_backpointer other_bp = *bkey_s_c_to_backpointer(bp_k).v;
582 
583 	struct bkey_s_c other_extent =
584 		bch2_backpointer_get_key(trans, &other_extent_iter, bp_k.k->p, other_bp, 0);
585 	ret = bkey_err(other_extent);
586 	if (ret == -BCH_ERR_backpointer_to_overwritten_btree_node)
587 		ret = 0;
588 	if (ret)
589 		goto err;
590 
591 	if (!other_extent.k)
592 		goto missing;
593 
594 	if (bch2_extents_match(orig_k, other_extent)) {
595 		printbuf_reset(&buf);
596 		prt_printf(&buf, "duplicate versions of same extent, deleting smaller\n  ");
597 		bch2_bkey_val_to_text(&buf, c, orig_k);
598 		prt_str(&buf, "\n  ");
599 		bch2_bkey_val_to_text(&buf, c, other_extent);
600 		bch_err(c, "%s", buf.buf);
601 
602 		if (other_extent.k->size <= orig_k.k->size) {
603 			ret = drop_dev_and_update(trans, other_bp.btree_id, other_extent, bucket.inode);
604 			if (ret)
605 				goto err;
606 			goto out;
607 		} else {
608 			ret = drop_dev_and_update(trans, bp.btree_id, orig_k, bucket.inode);
609 			if (ret)
610 				goto err;
611 			goto missing;
612 		}
613 	}
614 
615 	ret = check_extent_checksum(trans, other_bp.btree_id, other_extent, bp.btree_id, orig_k, bucket.inode);
616 	if (ret < 0)
617 		goto err;
618 	if (ret) {
619 		ret = 0;
620 		goto missing;
621 	}
622 
623 	ret = check_extent_checksum(trans, bp.btree_id, orig_k, other_bp.btree_id, other_extent, bucket.inode);
624 	if (ret < 0)
625 		goto err;
626 	if (ret) {
627 		ret = 0;
628 		goto out;
629 	}
630 
631 	printbuf_reset(&buf);
632 	prt_printf(&buf, "duplicate extents pointing to same space on dev %llu\n  ", bucket.inode);
633 	bch2_bkey_val_to_text(&buf, c, orig_k);
634 	prt_str(&buf, "\n  ");
635 	bch2_bkey_val_to_text(&buf, c, other_extent);
636 	bch_err(c, "%s", buf.buf);
637 	ret = -BCH_ERR_fsck_repair_unimplemented;
638 	goto err;
639 missing:
640 	printbuf_reset(&buf);
641 	prt_printf(&buf, "missing backpointer for btree=%s l=%u ",
642 	       bch2_btree_id_str(bp.btree_id), bp.level);
643 	bch2_bkey_val_to_text(&buf, c, orig_k);
644 	prt_printf(&buf, "\n  got:   ");
645 	bch2_bkey_val_to_text(&buf, c, bp_k);
646 
647 	struct bkey_i_backpointer n_bp_k;
648 	bkey_backpointer_init(&n_bp_k.k_i);
649 	n_bp_k.k.p = bucket_pos_to_bp(ca, bucket, bp.bucket_offset);
650 	n_bp_k.v = bp;
651 	prt_printf(&buf, "\n  want:  ");
652 	bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(&n_bp_k.k_i));
653 
654 	if (fsck_err(trans, ptr_to_missing_backpointer, "%s", buf.buf))
655 		ret = bch2_bucket_backpointer_mod(trans, ca, bucket, bp, orig_k, true);
656 
657 	goto out;
658 }
659 
check_extent_to_backpointers(struct btree_trans * trans,struct extents_to_bp_state * s,enum btree_id btree,unsigned level,struct bkey_s_c k)660 static int check_extent_to_backpointers(struct btree_trans *trans,
661 					struct extents_to_bp_state *s,
662 					enum btree_id btree, unsigned level,
663 					struct bkey_s_c k)
664 {
665 	struct bch_fs *c = trans->c;
666 	struct bkey_ptrs_c ptrs;
667 	const union bch_extent_entry *entry;
668 	struct extent_ptr_decoded p;
669 	int ret;
670 
671 	ptrs = bch2_bkey_ptrs_c(k);
672 	bkey_for_each_ptr_decode(k.k, ptrs, p, entry) {
673 		struct bpos bucket_pos = POS_MIN;
674 		struct bch_backpointer bp;
675 
676 		if (p.ptr.cached)
677 			continue;
678 
679 		rcu_read_lock();
680 		struct bch_dev *ca = bch2_dev_rcu_noerror(c, p.ptr.dev);
681 		if (ca)
682 			bch2_extent_ptr_to_bp(c, ca, btree, level, k, p, entry, &bucket_pos, &bp);
683 		rcu_read_unlock();
684 
685 		if (!ca)
686 			continue;
687 
688 		ret = check_bp_exists(trans, s, bucket_pos, bp, k);
689 		if (ret)
690 			return ret;
691 	}
692 
693 	return 0;
694 }
695 
check_btree_root_to_backpointers(struct btree_trans * trans,struct extents_to_bp_state * s,enum btree_id btree_id,int * level)696 static int check_btree_root_to_backpointers(struct btree_trans *trans,
697 					    struct extents_to_bp_state *s,
698 					    enum btree_id btree_id,
699 					    int *level)
700 {
701 	struct bch_fs *c = trans->c;
702 	struct btree_iter iter;
703 	struct btree *b;
704 	struct bkey_s_c k;
705 	int ret;
706 retry:
707 	bch2_trans_node_iter_init(trans, &iter, btree_id, POS_MIN,
708 				  0, bch2_btree_id_root(c, btree_id)->b->c.level, 0);
709 	b = bch2_btree_iter_peek_node(&iter);
710 	ret = PTR_ERR_OR_ZERO(b);
711 	if (ret)
712 		goto err;
713 
714 	if (b != btree_node_root(c, b)) {
715 		bch2_trans_iter_exit(trans, &iter);
716 		goto retry;
717 	}
718 
719 	*level = b->c.level;
720 
721 	k = bkey_i_to_s_c(&b->key);
722 	ret = check_extent_to_backpointers(trans, s, btree_id, b->c.level + 1, k);
723 err:
724 	bch2_trans_iter_exit(trans, &iter);
725 	return ret;
726 }
727 
bp_to_bbpos(struct bch_backpointer bp)728 static inline struct bbpos bp_to_bbpos(struct bch_backpointer bp)
729 {
730 	return (struct bbpos) {
731 		.btree	= bp.btree_id,
732 		.pos	= bp.pos,
733 	};
734 }
735 
mem_may_pin_bytes(struct bch_fs * c)736 static u64 mem_may_pin_bytes(struct bch_fs *c)
737 {
738 	struct sysinfo i;
739 	si_meminfo(&i);
740 
741 	u64 mem_bytes = i.totalram * i.mem_unit;
742 	return div_u64(mem_bytes * c->opts.fsck_memory_usage_percent, 100);
743 }
744 
btree_nodes_fit_in_ram(struct bch_fs * c)745 static size_t btree_nodes_fit_in_ram(struct bch_fs *c)
746 {
747 	return div_u64(mem_may_pin_bytes(c), c->opts.btree_node_size);
748 }
749 
bch2_get_btree_in_memory_pos(struct btree_trans * trans,u64 btree_leaf_mask,u64 btree_interior_mask,struct bbpos start,struct bbpos * end)750 static int bch2_get_btree_in_memory_pos(struct btree_trans *trans,
751 					u64 btree_leaf_mask,
752 					u64 btree_interior_mask,
753 					struct bbpos start, struct bbpos *end)
754 {
755 	struct bch_fs *c = trans->c;
756 	s64 mem_may_pin = mem_may_pin_bytes(c);
757 	int ret = 0;
758 
759 	bch2_btree_cache_unpin(c);
760 
761 	btree_interior_mask |= btree_leaf_mask;
762 
763 	c->btree_cache.pinned_nodes_mask[0]		= btree_leaf_mask;
764 	c->btree_cache.pinned_nodes_mask[1]		= btree_interior_mask;
765 	c->btree_cache.pinned_nodes_start		= start;
766 	c->btree_cache.pinned_nodes_end			= *end = BBPOS_MAX;
767 
768 	for (enum btree_id btree = start.btree;
769 	     btree < BTREE_ID_NR && !ret;
770 	     btree++) {
771 		unsigned depth = (BIT_ULL(btree) & btree_leaf_mask) ? 0 : 1;
772 
773 		if (!(BIT_ULL(btree) & btree_leaf_mask) &&
774 		    !(BIT_ULL(btree) & btree_interior_mask))
775 			continue;
776 
777 		ret = __for_each_btree_node(trans, iter, btree,
778 				      btree == start.btree ? start.pos : POS_MIN,
779 				      0, depth, BTREE_ITER_prefetch, b, ({
780 			mem_may_pin -= btree_buf_bytes(b);
781 			if (mem_may_pin <= 0) {
782 				c->btree_cache.pinned_nodes_end = *end =
783 					BBPOS(btree, b->key.k.p);
784 				break;
785 			}
786 			bch2_node_pin(c, b);
787 			0;
788 		}));
789 	}
790 
791 	return ret;
792 }
793 
794 struct progress_indicator_state {
795 	unsigned long		next_print;
796 	u64			nodes_seen;
797 	u64			nodes_total;
798 	struct btree		*last_node;
799 };
800 
progress_init(struct progress_indicator_state * s,struct bch_fs * c,u64 btree_id_mask)801 static inline void progress_init(struct progress_indicator_state *s,
802 				 struct bch_fs *c,
803 				 u64 btree_id_mask)
804 {
805 	memset(s, 0, sizeof(*s));
806 
807 	s->next_print = jiffies + HZ * 10;
808 
809 	for (unsigned i = 0; i < BTREE_ID_NR; i++) {
810 		if (!(btree_id_mask & BIT_ULL(i)))
811 			continue;
812 
813 		struct disk_accounting_pos acc = {
814 			.type		= BCH_DISK_ACCOUNTING_btree,
815 			.btree.id	= i,
816 		};
817 
818 		u64 v;
819 		bch2_accounting_mem_read(c, disk_accounting_pos_to_bpos(&acc), &v, 1);
820 		s->nodes_total += div64_ul(v, btree_sectors(c));
821 	}
822 }
823 
progress_update_p(struct progress_indicator_state * s)824 static inline bool progress_update_p(struct progress_indicator_state *s)
825 {
826 	bool ret = time_after_eq(jiffies, s->next_print);
827 
828 	if (ret)
829 		s->next_print = jiffies + HZ * 10;
830 	return ret;
831 }
832 
progress_update_iter(struct btree_trans * trans,struct progress_indicator_state * s,struct btree_iter * iter,const char * msg)833 static void progress_update_iter(struct btree_trans *trans,
834 				 struct progress_indicator_state *s,
835 				 struct btree_iter *iter,
836 				 const char *msg)
837 {
838 	struct bch_fs *c = trans->c;
839 	struct btree *b = path_l(btree_iter_path(trans, iter))->b;
840 
841 	s->nodes_seen += b != s->last_node;
842 	s->last_node = b;
843 
844 	if (progress_update_p(s)) {
845 		struct printbuf buf = PRINTBUF;
846 		unsigned percent = s->nodes_total
847 			? div64_u64(s->nodes_seen * 100, s->nodes_total)
848 			: 0;
849 
850 		prt_printf(&buf, "%s: %d%%, done %llu/%llu nodes, at ",
851 			   msg, percent, s->nodes_seen, s->nodes_total);
852 		bch2_bbpos_to_text(&buf, BBPOS(iter->btree_id, iter->pos));
853 
854 		bch_info(c, "%s", buf.buf);
855 		printbuf_exit(&buf);
856 	}
857 }
858 
bch2_check_extents_to_backpointers_pass(struct btree_trans * trans,struct extents_to_bp_state * s)859 static int bch2_check_extents_to_backpointers_pass(struct btree_trans *trans,
860 						   struct extents_to_bp_state *s)
861 {
862 	struct bch_fs *c = trans->c;
863 	struct progress_indicator_state progress;
864 	int ret = 0;
865 
866 	progress_init(&progress, trans->c, BIT_ULL(BTREE_ID_extents)|BIT_ULL(BTREE_ID_reflink));
867 
868 	for (enum btree_id btree_id = 0;
869 	     btree_id < btree_id_nr_alive(c);
870 	     btree_id++) {
871 		int level, depth = btree_type_has_ptrs(btree_id) ? 0 : 1;
872 
873 		ret = commit_do(trans, NULL, NULL,
874 				BCH_TRANS_COMMIT_no_enospc,
875 				check_btree_root_to_backpointers(trans, s, btree_id, &level));
876 		if (ret)
877 			return ret;
878 
879 		while (level >= depth) {
880 			struct btree_iter iter;
881 			bch2_trans_node_iter_init(trans, &iter, btree_id, POS_MIN, 0, level,
882 						  BTREE_ITER_prefetch);
883 
884 			ret = for_each_btree_key_continue(trans, iter, 0, k, ({
885 				progress_update_iter(trans, &progress, &iter, "extents_to_backpointers");
886 				check_extent_to_backpointers(trans, s, btree_id, level, k) ?:
887 				bch2_trans_commit(trans, NULL, NULL, BCH_TRANS_COMMIT_no_enospc);
888 			}));
889 			if (ret)
890 				return ret;
891 
892 			--level;
893 		}
894 	}
895 
896 	return 0;
897 }
898 
bch2_check_extents_to_backpointers(struct bch_fs * c)899 int bch2_check_extents_to_backpointers(struct bch_fs *c)
900 {
901 	struct btree_trans *trans = bch2_trans_get(c);
902 	struct extents_to_bp_state s = { .bucket_start = POS_MIN };
903 	int ret;
904 
905 	bch2_bkey_buf_init(&s.last_flushed);
906 	bkey_init(&s.last_flushed.k->k);
907 
908 	while (1) {
909 		struct bbpos end;
910 		ret = bch2_get_btree_in_memory_pos(trans,
911 				BIT_ULL(BTREE_ID_backpointers),
912 				BIT_ULL(BTREE_ID_backpointers),
913 				BBPOS(BTREE_ID_backpointers, s.bucket_start), &end);
914 		if (ret)
915 			break;
916 
917 		s.bucket_end = end.pos;
918 
919 		if ( bpos_eq(s.bucket_start, POS_MIN) &&
920 		    !bpos_eq(s.bucket_end, SPOS_MAX))
921 			bch_verbose(c, "%s(): alloc info does not fit in ram, running in multiple passes with %zu nodes per pass",
922 				    __func__, btree_nodes_fit_in_ram(c));
923 
924 		if (!bpos_eq(s.bucket_start, POS_MIN) ||
925 		    !bpos_eq(s.bucket_end, SPOS_MAX)) {
926 			struct printbuf buf = PRINTBUF;
927 
928 			prt_str(&buf, "check_extents_to_backpointers(): ");
929 			bch2_bpos_to_text(&buf, s.bucket_start);
930 			prt_str(&buf, "-");
931 			bch2_bpos_to_text(&buf, s.bucket_end);
932 
933 			bch_verbose(c, "%s", buf.buf);
934 			printbuf_exit(&buf);
935 		}
936 
937 		ret = bch2_check_extents_to_backpointers_pass(trans, &s);
938 		if (ret || bpos_eq(s.bucket_end, SPOS_MAX))
939 			break;
940 
941 		s.bucket_start = bpos_successor(s.bucket_end);
942 	}
943 	bch2_trans_put(trans);
944 	bch2_bkey_buf_exit(&s.last_flushed, c);
945 
946 	bch2_btree_cache_unpin(c);
947 
948 	bch_err_fn(c, ret);
949 	return ret;
950 }
951 
check_one_backpointer(struct btree_trans * trans,struct bbpos start,struct bbpos end,struct bkey_s_c bp_k,struct bkey_buf * last_flushed)952 static int check_one_backpointer(struct btree_trans *trans,
953 				 struct bbpos start,
954 				 struct bbpos end,
955 				 struct bkey_s_c bp_k,
956 				 struct bkey_buf *last_flushed)
957 {
958 	if (bp_k.k->type != KEY_TYPE_backpointer)
959 		return 0;
960 
961 	struct bkey_s_c_backpointer bp = bkey_s_c_to_backpointer(bp_k);
962 	struct bch_fs *c = trans->c;
963 	struct btree_iter iter;
964 	struct bbpos pos = bp_to_bbpos(*bp.v);
965 	struct bkey_s_c k;
966 	struct printbuf buf = PRINTBUF;
967 	int ret;
968 
969 	if (bbpos_cmp(pos, start) < 0 ||
970 	    bbpos_cmp(pos, end) > 0)
971 		return 0;
972 
973 	k = bch2_backpointer_get_key(trans, &iter, bp.k->p, *bp.v, 0);
974 	ret = bkey_err(k);
975 	if (ret == -BCH_ERR_backpointer_to_overwritten_btree_node)
976 		return 0;
977 	if (ret)
978 		return ret;
979 
980 	if (!k.k) {
981 		ret = bch2_btree_write_buffer_maybe_flush(trans, bp.s_c, last_flushed);
982 		if (ret)
983 			goto out;
984 
985 		if (fsck_err(trans, backpointer_to_missing_ptr,
986 			     "backpointer for missing %s\n  %s",
987 			     bp.v->level ? "btree node" : "extent",
988 			     (bch2_bkey_val_to_text(&buf, c, bp.s_c), buf.buf))) {
989 			ret = bch2_btree_delete_at_buffered(trans, BTREE_ID_backpointers, bp.k->p);
990 			goto out;
991 		}
992 	}
993 out:
994 fsck_err:
995 	bch2_trans_iter_exit(trans, &iter);
996 	printbuf_exit(&buf);
997 	return ret;
998 }
999 
bch2_check_backpointers_to_extents_pass(struct btree_trans * trans,struct bbpos start,struct bbpos end)1000 static int bch2_check_backpointers_to_extents_pass(struct btree_trans *trans,
1001 						   struct bbpos start,
1002 						   struct bbpos end)
1003 {
1004 	struct bch_fs *c = trans->c;
1005 	struct bkey_buf last_flushed;
1006 	struct progress_indicator_state progress;
1007 
1008 	bch2_bkey_buf_init(&last_flushed);
1009 	bkey_init(&last_flushed.k->k);
1010 	progress_init(&progress, trans->c, BIT_ULL(BTREE_ID_backpointers));
1011 
1012 	int ret = for_each_btree_key_commit(trans, iter, BTREE_ID_backpointers,
1013 				  POS_MIN, BTREE_ITER_prefetch, k,
1014 				  NULL, NULL, BCH_TRANS_COMMIT_no_enospc, ({
1015 			progress_update_iter(trans, &progress, &iter, "backpointers_to_extents");
1016 			check_one_backpointer(trans, start, end, k, &last_flushed);
1017 	}));
1018 
1019 	bch2_bkey_buf_exit(&last_flushed, c);
1020 	return ret;
1021 }
1022 
bch2_check_backpointers_to_extents(struct bch_fs * c)1023 int bch2_check_backpointers_to_extents(struct bch_fs *c)
1024 {
1025 	struct btree_trans *trans = bch2_trans_get(c);
1026 	struct bbpos start = (struct bbpos) { .btree = 0, .pos = POS_MIN, }, end;
1027 	int ret;
1028 
1029 	while (1) {
1030 		ret = bch2_get_btree_in_memory_pos(trans,
1031 						   BIT_ULL(BTREE_ID_extents)|
1032 						   BIT_ULL(BTREE_ID_reflink),
1033 						   ~0,
1034 						   start, &end);
1035 		if (ret)
1036 			break;
1037 
1038 		if (!bbpos_cmp(start, BBPOS_MIN) &&
1039 		    bbpos_cmp(end, BBPOS_MAX))
1040 			bch_verbose(c, "%s(): extents do not fit in ram, running in multiple passes with %zu nodes per pass",
1041 				    __func__, btree_nodes_fit_in_ram(c));
1042 
1043 		if (bbpos_cmp(start, BBPOS_MIN) ||
1044 		    bbpos_cmp(end, BBPOS_MAX)) {
1045 			struct printbuf buf = PRINTBUF;
1046 
1047 			prt_str(&buf, "check_backpointers_to_extents(): ");
1048 			bch2_bbpos_to_text(&buf, start);
1049 			prt_str(&buf, "-");
1050 			bch2_bbpos_to_text(&buf, end);
1051 
1052 			bch_verbose(c, "%s", buf.buf);
1053 			printbuf_exit(&buf);
1054 		}
1055 
1056 		ret = bch2_check_backpointers_to_extents_pass(trans, start, end);
1057 		if (ret || !bbpos_cmp(end, BBPOS_MAX))
1058 			break;
1059 
1060 		start = bbpos_successor(end);
1061 	}
1062 	bch2_trans_put(trans);
1063 
1064 	bch2_btree_cache_unpin(c);
1065 
1066 	bch_err_fn(c, ret);
1067 	return ret;
1068 }
1069