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Merge tag 'loongarch-kvm-6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/chenhu...
[thirdparty/kernel/stable.git] / fs / bcachefs / btree_iter.c
1 // SPDX-License-Identifier: GPL-2.0
2
3 #include "bcachefs.h"
4 #include "bkey_methods.h"
5 #include "bkey_buf.h"
6 #include "btree_cache.h"
7 #include "btree_iter.h"
8 #include "btree_journal_iter.h"
9 #include "btree_key_cache.h"
10 #include "btree_locking.h"
11 #include "btree_update.h"
12 #include "debug.h"
13 #include "error.h"
14 #include "extents.h"
15 #include "journal.h"
16 #include "replicas.h"
17 #include "snapshot.h"
18 #include "trace.h"
19
20 #include <linux/random.h>
21 #include <linux/prefetch.h>
22
23 static inline void btree_path_list_remove(struct btree_trans *, struct btree_path *);
24 static inline void btree_path_list_add(struct btree_trans *, struct btree_path *,
25 struct btree_path *);
26
27 static inline unsigned long btree_iter_ip_allocated(struct btree_iter *iter)
28 {
29 #ifdef TRACK_PATH_ALLOCATED
30 return iter->ip_allocated;
31 #else
32 return 0;
33 #endif
34 }
35
36 static struct btree_path *btree_path_alloc(struct btree_trans *, struct btree_path *);
37
38 static inline int __btree_path_cmp(const struct btree_path *l,
39 enum btree_id r_btree_id,
40 bool r_cached,
41 struct bpos r_pos,
42 unsigned r_level)
43 {
44 /*
45 * Must match lock ordering as defined by __bch2_btree_node_lock:
46 */
47 return cmp_int(l->btree_id, r_btree_id) ?:
48 cmp_int((int) l->cached, (int) r_cached) ?:
49 bpos_cmp(l->pos, r_pos) ?:
50 -cmp_int(l->level, r_level);
51 }
52
53 static inline int btree_path_cmp(const struct btree_path *l,
54 const struct btree_path *r)
55 {
56 return __btree_path_cmp(l, r->btree_id, r->cached, r->pos, r->level);
57 }
58
59 static inline struct bpos bkey_successor(struct btree_iter *iter, struct bpos p)
60 {
61 /* Are we iterating over keys in all snapshots? */
62 if (iter->flags & BTREE_ITER_ALL_SNAPSHOTS) {
63 p = bpos_successor(p);
64 } else {
65 p = bpos_nosnap_successor(p);
66 p.snapshot = iter->snapshot;
67 }
68
69 return p;
70 }
71
72 static inline struct bpos bkey_predecessor(struct btree_iter *iter, struct bpos p)
73 {
74 /* Are we iterating over keys in all snapshots? */
75 if (iter->flags & BTREE_ITER_ALL_SNAPSHOTS) {
76 p = bpos_predecessor(p);
77 } else {
78 p = bpos_nosnap_predecessor(p);
79 p.snapshot = iter->snapshot;
80 }
81
82 return p;
83 }
84
85 static inline struct bpos btree_iter_search_key(struct btree_iter *iter)
86 {
87 struct bpos pos = iter->pos;
88
89 if ((iter->flags & BTREE_ITER_IS_EXTENTS) &&
90 !bkey_eq(pos, POS_MAX))
91 pos = bkey_successor(iter, pos);
92 return pos;
93 }
94
95 static inline bool btree_path_pos_before_node(struct btree_path *path,
96 struct btree *b)
97 {
98 return bpos_lt(path->pos, b->data->min_key);
99 }
100
101 static inline bool btree_path_pos_after_node(struct btree_path *path,
102 struct btree *b)
103 {
104 return bpos_gt(path->pos, b->key.k.p);
105 }
106
107 static inline bool btree_path_pos_in_node(struct btree_path *path,
108 struct btree *b)
109 {
110 return path->btree_id == b->c.btree_id &&
111 !btree_path_pos_before_node(path, b) &&
112 !btree_path_pos_after_node(path, b);
113 }
114
115 /* Btree iterator: */
116
117 #ifdef CONFIG_BCACHEFS_DEBUG
118
119 static void bch2_btree_path_verify_cached(struct btree_trans *trans,
120 struct btree_path *path)
121 {
122 struct bkey_cached *ck;
123 bool locked = btree_node_locked(path, 0);
124
125 if (!bch2_btree_node_relock(trans, path, 0))
126 return;
127
128 ck = (void *) path->l[0].b;
129 BUG_ON(ck->key.btree_id != path->btree_id ||
130 !bkey_eq(ck->key.pos, path->pos));
131
132 if (!locked)
133 btree_node_unlock(trans, path, 0);
134 }
135
136 static void bch2_btree_path_verify_level(struct btree_trans *trans,
137 struct btree_path *path, unsigned level)
138 {
139 struct btree_path_level *l;
140 struct btree_node_iter tmp;
141 bool locked;
142 struct bkey_packed *p, *k;
143 struct printbuf buf1 = PRINTBUF;
144 struct printbuf buf2 = PRINTBUF;
145 struct printbuf buf3 = PRINTBUF;
146 const char *msg;
147
148 if (!bch2_debug_check_iterators)
149 return;
150
151 l = &path->l[level];
152 tmp = l->iter;
153 locked = btree_node_locked(path, level);
154
155 if (path->cached) {
156 if (!level)
157 bch2_btree_path_verify_cached(trans, path);
158 return;
159 }
160
161 if (!btree_path_node(path, level))
162 return;
163
164 if (!bch2_btree_node_relock_notrace(trans, path, level))
165 return;
166
167 BUG_ON(!btree_path_pos_in_node(path, l->b));
168
169 bch2_btree_node_iter_verify(&l->iter, l->b);
170
171 /*
172 * For interior nodes, the iterator will have skipped past deleted keys:
173 */
174 p = level
175 ? bch2_btree_node_iter_prev(&tmp, l->b)
176 : bch2_btree_node_iter_prev_all(&tmp, l->b);
177 k = bch2_btree_node_iter_peek_all(&l->iter, l->b);
178
179 if (p && bkey_iter_pos_cmp(l->b, p, &path->pos) >= 0) {
180 msg = "before";
181 goto err;
182 }
183
184 if (k && bkey_iter_pos_cmp(l->b, k, &path->pos) < 0) {
185 msg = "after";
186 goto err;
187 }
188
189 if (!locked)
190 btree_node_unlock(trans, path, level);
191 return;
192 err:
193 bch2_bpos_to_text(&buf1, path->pos);
194
195 if (p) {
196 struct bkey uk = bkey_unpack_key(l->b, p);
197
198 bch2_bkey_to_text(&buf2, &uk);
199 } else {
200 prt_printf(&buf2, "(none)");
201 }
202
203 if (k) {
204 struct bkey uk = bkey_unpack_key(l->b, k);
205
206 bch2_bkey_to_text(&buf3, &uk);
207 } else {
208 prt_printf(&buf3, "(none)");
209 }
210
211 panic("path should be %s key at level %u:\n"
212 "path pos %s\n"
213 "prev key %s\n"
214 "cur key %s\n",
215 msg, level, buf1.buf, buf2.buf, buf3.buf);
216 }
217
218 static void bch2_btree_path_verify(struct btree_trans *trans,
219 struct btree_path *path)
220 {
221 struct bch_fs *c = trans->c;
222 unsigned i;
223
224 EBUG_ON(path->btree_id >= BTREE_ID_NR);
225
226 for (i = 0; i < (!path->cached ? BTREE_MAX_DEPTH : 1); i++) {
227 if (!path->l[i].b) {
228 BUG_ON(!path->cached &&
229 bch2_btree_id_root(c, path->btree_id)->b->c.level > i);
230 break;
231 }
232
233 bch2_btree_path_verify_level(trans, path, i);
234 }
235
236 bch2_btree_path_verify_locks(path);
237 }
238
239 void bch2_trans_verify_paths(struct btree_trans *trans)
240 {
241 struct btree_path *path;
242
243 trans_for_each_path(trans, path)
244 bch2_btree_path_verify(trans, path);
245 }
246
247 static void bch2_btree_iter_verify(struct btree_iter *iter)
248 {
249 struct btree_trans *trans = iter->trans;
250
251 BUG_ON(iter->btree_id >= BTREE_ID_NR);
252
253 BUG_ON(!!(iter->flags & BTREE_ITER_CACHED) != iter->path->cached);
254
255 BUG_ON((iter->flags & BTREE_ITER_IS_EXTENTS) &&
256 (iter->flags & BTREE_ITER_ALL_SNAPSHOTS));
257
258 BUG_ON(!(iter->flags & __BTREE_ITER_ALL_SNAPSHOTS) &&
259 (iter->flags & BTREE_ITER_ALL_SNAPSHOTS) &&
260 !btree_type_has_snapshot_field(iter->btree_id));
261
262 if (iter->update_path)
263 bch2_btree_path_verify(trans, iter->update_path);
264 bch2_btree_path_verify(trans, iter->path);
265 }
266
267 static void bch2_btree_iter_verify_entry_exit(struct btree_iter *iter)
268 {
269 BUG_ON((iter->flags & BTREE_ITER_FILTER_SNAPSHOTS) &&
270 !iter->pos.snapshot);
271
272 BUG_ON(!(iter->flags & BTREE_ITER_ALL_SNAPSHOTS) &&
273 iter->pos.snapshot != iter->snapshot);
274
275 BUG_ON(bkey_lt(iter->pos, bkey_start_pos(&iter->k)) ||
276 bkey_gt(iter->pos, iter->k.p));
277 }
278
279 static int bch2_btree_iter_verify_ret(struct btree_iter *iter, struct bkey_s_c k)
280 {
281 struct btree_trans *trans = iter->trans;
282 struct btree_iter copy;
283 struct bkey_s_c prev;
284 int ret = 0;
285
286 if (!bch2_debug_check_iterators)
287 return 0;
288
289 if (!(iter->flags & BTREE_ITER_FILTER_SNAPSHOTS))
290 return 0;
291
292 if (bkey_err(k) || !k.k)
293 return 0;
294
295 BUG_ON(!bch2_snapshot_is_ancestor(trans->c,
296 iter->snapshot,
297 k.k->p.snapshot));
298
299 bch2_trans_iter_init(trans, &copy, iter->btree_id, iter->pos,
300 BTREE_ITER_NOPRESERVE|
301 BTREE_ITER_ALL_SNAPSHOTS);
302 prev = bch2_btree_iter_prev(&copy);
303 if (!prev.k)
304 goto out;
305
306 ret = bkey_err(prev);
307 if (ret)
308 goto out;
309
310 if (bkey_eq(prev.k->p, k.k->p) &&
311 bch2_snapshot_is_ancestor(trans->c, iter->snapshot,
312 prev.k->p.snapshot) > 0) {
313 struct printbuf buf1 = PRINTBUF, buf2 = PRINTBUF;
314
315 bch2_bkey_to_text(&buf1, k.k);
316 bch2_bkey_to_text(&buf2, prev.k);
317
318 panic("iter snap %u\n"
319 "k %s\n"
320 "prev %s\n",
321 iter->snapshot,
322 buf1.buf, buf2.buf);
323 }
324 out:
325 bch2_trans_iter_exit(trans, &copy);
326 return ret;
327 }
328
329 void bch2_assert_pos_locked(struct btree_trans *trans, enum btree_id id,
330 struct bpos pos, bool key_cache)
331 {
332 struct btree_path *path;
333 unsigned idx;
334 struct printbuf buf = PRINTBUF;
335
336 btree_trans_sort_paths(trans);
337
338 trans_for_each_path_inorder(trans, path, idx) {
339 int cmp = cmp_int(path->btree_id, id) ?:
340 cmp_int(path->cached, key_cache);
341
342 if (cmp > 0)
343 break;
344 if (cmp < 0)
345 continue;
346
347 if (!btree_node_locked(path, 0) ||
348 !path->should_be_locked)
349 continue;
350
351 if (!key_cache) {
352 if (bkey_ge(pos, path->l[0].b->data->min_key) &&
353 bkey_le(pos, path->l[0].b->key.k.p))
354 return;
355 } else {
356 if (bkey_eq(pos, path->pos))
357 return;
358 }
359 }
360
361 bch2_dump_trans_paths_updates(trans);
362 bch2_bpos_to_text(&buf, pos);
363
364 panic("not locked: %s %s%s\n",
365 bch2_btree_id_str(id), buf.buf,
366 key_cache ? " cached" : "");
367 }
368
369 #else
370
371 static inline void bch2_btree_path_verify_level(struct btree_trans *trans,
372 struct btree_path *path, unsigned l) {}
373 static inline void bch2_btree_path_verify(struct btree_trans *trans,
374 struct btree_path *path) {}
375 static inline void bch2_btree_iter_verify(struct btree_iter *iter) {}
376 static inline void bch2_btree_iter_verify_entry_exit(struct btree_iter *iter) {}
377 static inline int bch2_btree_iter_verify_ret(struct btree_iter *iter, struct bkey_s_c k) { return 0; }
378
379 #endif
380
381 /* Btree path: fixups after btree updates */
382
383 static void btree_node_iter_set_set_pos(struct btree_node_iter *iter,
384 struct btree *b,
385 struct bset_tree *t,
386 struct bkey_packed *k)
387 {
388 struct btree_node_iter_set *set;
389
390 btree_node_iter_for_each(iter, set)
391 if (set->end == t->end_offset) {
392 set->k = __btree_node_key_to_offset(b, k);
393 bch2_btree_node_iter_sort(iter, b);
394 return;
395 }
396
397 bch2_btree_node_iter_push(iter, b, k, btree_bkey_last(b, t));
398 }
399
400 static void __bch2_btree_path_fix_key_modified(struct btree_path *path,
401 struct btree *b,
402 struct bkey_packed *where)
403 {
404 struct btree_path_level *l = &path->l[b->c.level];
405
406 if (where != bch2_btree_node_iter_peek_all(&l->iter, l->b))
407 return;
408
409 if (bkey_iter_pos_cmp(l->b, where, &path->pos) < 0)
410 bch2_btree_node_iter_advance(&l->iter, l->b);
411 }
412
413 void bch2_btree_path_fix_key_modified(struct btree_trans *trans,
414 struct btree *b,
415 struct bkey_packed *where)
416 {
417 struct btree_path *path;
418
419 trans_for_each_path_with_node(trans, b, path) {
420 __bch2_btree_path_fix_key_modified(path, b, where);
421 bch2_btree_path_verify_level(trans, path, b->c.level);
422 }
423 }
424
425 static void __bch2_btree_node_iter_fix(struct btree_path *path,
426 struct btree *b,
427 struct btree_node_iter *node_iter,
428 struct bset_tree *t,
429 struct bkey_packed *where,
430 unsigned clobber_u64s,
431 unsigned new_u64s)
432 {
433 const struct bkey_packed *end = btree_bkey_last(b, t);
434 struct btree_node_iter_set *set;
435 unsigned offset = __btree_node_key_to_offset(b, where);
436 int shift = new_u64s - clobber_u64s;
437 unsigned old_end = t->end_offset - shift;
438 unsigned orig_iter_pos = node_iter->data[0].k;
439 bool iter_current_key_modified =
440 orig_iter_pos >= offset &&
441 orig_iter_pos <= offset + clobber_u64s;
442
443 btree_node_iter_for_each(node_iter, set)
444 if (set->end == old_end)
445 goto found;
446
447 /* didn't find the bset in the iterator - might have to readd it: */
448 if (new_u64s &&
449 bkey_iter_pos_cmp(b, where, &path->pos) >= 0) {
450 bch2_btree_node_iter_push(node_iter, b, where, end);
451 goto fixup_done;
452 } else {
453 /* Iterator is after key that changed */
454 return;
455 }
456 found:
457 set->end = t->end_offset;
458
459 /* Iterator hasn't gotten to the key that changed yet: */
460 if (set->k < offset)
461 return;
462
463 if (new_u64s &&
464 bkey_iter_pos_cmp(b, where, &path->pos) >= 0) {
465 set->k = offset;
466 } else if (set->k < offset + clobber_u64s) {
467 set->k = offset + new_u64s;
468 if (set->k == set->end)
469 bch2_btree_node_iter_set_drop(node_iter, set);
470 } else {
471 /* Iterator is after key that changed */
472 set->k = (int) set->k + shift;
473 return;
474 }
475
476 bch2_btree_node_iter_sort(node_iter, b);
477 fixup_done:
478 if (node_iter->data[0].k != orig_iter_pos)
479 iter_current_key_modified = true;
480
481 /*
482 * When a new key is added, and the node iterator now points to that
483 * key, the iterator might have skipped past deleted keys that should
484 * come after the key the iterator now points to. We have to rewind to
485 * before those deleted keys - otherwise
486 * bch2_btree_node_iter_prev_all() breaks:
487 */
488 if (!bch2_btree_node_iter_end(node_iter) &&
489 iter_current_key_modified &&
490 b->c.level) {
491 struct bkey_packed *k, *k2, *p;
492
493 k = bch2_btree_node_iter_peek_all(node_iter, b);
494
495 for_each_bset(b, t) {
496 bool set_pos = false;
497
498 if (node_iter->data[0].end == t->end_offset)
499 continue;
500
501 k2 = bch2_btree_node_iter_bset_pos(node_iter, b, t);
502
503 while ((p = bch2_bkey_prev_all(b, t, k2)) &&
504 bkey_iter_cmp(b, k, p) < 0) {
505 k2 = p;
506 set_pos = true;
507 }
508
509 if (set_pos)
510 btree_node_iter_set_set_pos(node_iter,
511 b, t, k2);
512 }
513 }
514 }
515
516 void bch2_btree_node_iter_fix(struct btree_trans *trans,
517 struct btree_path *path,
518 struct btree *b,
519 struct btree_node_iter *node_iter,
520 struct bkey_packed *where,
521 unsigned clobber_u64s,
522 unsigned new_u64s)
523 {
524 struct bset_tree *t = bch2_bkey_to_bset_inlined(b, where);
525 struct btree_path *linked;
526
527 if (node_iter != &path->l[b->c.level].iter) {
528 __bch2_btree_node_iter_fix(path, b, node_iter, t,
529 where, clobber_u64s, new_u64s);
530
531 if (bch2_debug_check_iterators)
532 bch2_btree_node_iter_verify(node_iter, b);
533 }
534
535 trans_for_each_path_with_node(trans, b, linked) {
536 __bch2_btree_node_iter_fix(linked, b,
537 &linked->l[b->c.level].iter, t,
538 where, clobber_u64s, new_u64s);
539 bch2_btree_path_verify_level(trans, linked, b->c.level);
540 }
541 }
542
543 /* Btree path level: pointer to a particular btree node and node iter */
544
545 static inline struct bkey_s_c __btree_iter_unpack(struct bch_fs *c,
546 struct btree_path_level *l,
547 struct bkey *u,
548 struct bkey_packed *k)
549 {
550 if (unlikely(!k)) {
551 /*
552 * signal to bch2_btree_iter_peek_slot() that we're currently at
553 * a hole
554 */
555 u->type = KEY_TYPE_deleted;
556 return bkey_s_c_null;
557 }
558
559 return bkey_disassemble(l->b, k, u);
560 }
561
562 static inline struct bkey_s_c btree_path_level_peek_all(struct bch_fs *c,
563 struct btree_path_level *l,
564 struct bkey *u)
565 {
566 return __btree_iter_unpack(c, l, u,
567 bch2_btree_node_iter_peek_all(&l->iter, l->b));
568 }
569
570 static inline struct bkey_s_c btree_path_level_peek(struct btree_trans *trans,
571 struct btree_path *path,
572 struct btree_path_level *l,
573 struct bkey *u)
574 {
575 struct bkey_s_c k = __btree_iter_unpack(trans->c, l, u,
576 bch2_btree_node_iter_peek(&l->iter, l->b));
577
578 path->pos = k.k ? k.k->p : l->b->key.k.p;
579 trans->paths_sorted = false;
580 bch2_btree_path_verify_level(trans, path, l - path->l);
581 return k;
582 }
583
584 static inline struct bkey_s_c btree_path_level_prev(struct btree_trans *trans,
585 struct btree_path *path,
586 struct btree_path_level *l,
587 struct bkey *u)
588 {
589 struct bkey_s_c k = __btree_iter_unpack(trans->c, l, u,
590 bch2_btree_node_iter_prev(&l->iter, l->b));
591
592 path->pos = k.k ? k.k->p : l->b->data->min_key;
593 trans->paths_sorted = false;
594 bch2_btree_path_verify_level(trans, path, l - path->l);
595 return k;
596 }
597
598 static inline bool btree_path_advance_to_pos(struct btree_path *path,
599 struct btree_path_level *l,
600 int max_advance)
601 {
602 struct bkey_packed *k;
603 int nr_advanced = 0;
604
605 while ((k = bch2_btree_node_iter_peek_all(&l->iter, l->b)) &&
606 bkey_iter_pos_cmp(l->b, k, &path->pos) < 0) {
607 if (max_advance > 0 && nr_advanced >= max_advance)
608 return false;
609
610 bch2_btree_node_iter_advance(&l->iter, l->b);
611 nr_advanced++;
612 }
613
614 return true;
615 }
616
617 static inline void __btree_path_level_init(struct btree_path *path,
618 unsigned level)
619 {
620 struct btree_path_level *l = &path->l[level];
621
622 bch2_btree_node_iter_init(&l->iter, l->b, &path->pos);
623
624 /*
625 * Iterators to interior nodes should always be pointed at the first non
626 * whiteout:
627 */
628 if (level)
629 bch2_btree_node_iter_peek(&l->iter, l->b);
630 }
631
632 void bch2_btree_path_level_init(struct btree_trans *trans,
633 struct btree_path *path,
634 struct btree *b)
635 {
636 BUG_ON(path->cached);
637
638 EBUG_ON(!btree_path_pos_in_node(path, b));
639
640 path->l[b->c.level].lock_seq = six_lock_seq(&b->c.lock);
641 path->l[b->c.level].b = b;
642 __btree_path_level_init(path, b->c.level);
643 }
644
645 /* Btree path: fixups after btree node updates: */
646
647 static void bch2_trans_revalidate_updates_in_node(struct btree_trans *trans, struct btree *b)
648 {
649 struct bch_fs *c = trans->c;
650 struct btree_insert_entry *i;
651
652 trans_for_each_update(trans, i)
653 if (!i->cached &&
654 i->level == b->c.level &&
655 i->btree_id == b->c.btree_id &&
656 bpos_cmp(i->k->k.p, b->data->min_key) >= 0 &&
657 bpos_cmp(i->k->k.p, b->data->max_key) <= 0) {
658 i->old_v = bch2_btree_path_peek_slot(i->path, &i->old_k).v;
659
660 if (unlikely(trans->journal_replay_not_finished)) {
661 struct bkey_i *j_k =
662 bch2_journal_keys_peek_slot(c, i->btree_id, i->level,
663 i->k->k.p);
664
665 if (j_k) {
666 i->old_k = j_k->k;
667 i->old_v = &j_k->v;
668 }
669 }
670 }
671 }
672
673 /*
674 * A btree node is being replaced - update the iterator to point to the new
675 * node:
676 */
677 void bch2_trans_node_add(struct btree_trans *trans, struct btree *b)
678 {
679 struct btree_path *path;
680
681 trans_for_each_path(trans, path)
682 if (path->uptodate == BTREE_ITER_UPTODATE &&
683 !path->cached &&
684 btree_path_pos_in_node(path, b)) {
685 enum btree_node_locked_type t =
686 btree_lock_want(path, b->c.level);
687
688 if (t != BTREE_NODE_UNLOCKED) {
689 btree_node_unlock(trans, path, b->c.level);
690 six_lock_increment(&b->c.lock, (enum six_lock_type) t);
691 mark_btree_node_locked(trans, path, b->c.level, t);
692 }
693
694 bch2_btree_path_level_init(trans, path, b);
695 }
696
697 bch2_trans_revalidate_updates_in_node(trans, b);
698 }
699
700 /*
701 * A btree node has been modified in such a way as to invalidate iterators - fix
702 * them:
703 */
704 void bch2_trans_node_reinit_iter(struct btree_trans *trans, struct btree *b)
705 {
706 struct btree_path *path;
707
708 trans_for_each_path_with_node(trans, b, path)
709 __btree_path_level_init(path, b->c.level);
710
711 bch2_trans_revalidate_updates_in_node(trans, b);
712 }
713
714 /* Btree path: traverse, set_pos: */
715
716 static inline int btree_path_lock_root(struct btree_trans *trans,
717 struct btree_path *path,
718 unsigned depth_want,
719 unsigned long trace_ip)
720 {
721 struct bch_fs *c = trans->c;
722 struct btree *b, **rootp = &bch2_btree_id_root(c, path->btree_id)->b;
723 enum six_lock_type lock_type;
724 unsigned i;
725 int ret;
726
727 EBUG_ON(path->nodes_locked);
728
729 while (1) {
730 b = READ_ONCE(*rootp);
731 path->level = READ_ONCE(b->c.level);
732
733 if (unlikely(path->level < depth_want)) {
734 /*
735 * the root is at a lower depth than the depth we want:
736 * got to the end of the btree, or we're walking nodes
737 * greater than some depth and there are no nodes >=
738 * that depth
739 */
740 path->level = depth_want;
741 for (i = path->level; i < BTREE_MAX_DEPTH; i++)
742 path->l[i].b = NULL;
743 return 1;
744 }
745
746 lock_type = __btree_lock_want(path, path->level);
747 ret = btree_node_lock(trans, path, &b->c,
748 path->level, lock_type, trace_ip);
749 if (unlikely(ret)) {
750 if (bch2_err_matches(ret, BCH_ERR_lock_fail_root_changed))
751 continue;
752 if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
753 return ret;
754 BUG();
755 }
756
757 if (likely(b == READ_ONCE(*rootp) &&
758 b->c.level == path->level &&
759 !race_fault())) {
760 for (i = 0; i < path->level; i++)
761 path->l[i].b = ERR_PTR(-BCH_ERR_no_btree_node_lock_root);
762 path->l[path->level].b = b;
763 for (i = path->level + 1; i < BTREE_MAX_DEPTH; i++)
764 path->l[i].b = NULL;
765
766 mark_btree_node_locked(trans, path, path->level,
767 (enum btree_node_locked_type) lock_type);
768 bch2_btree_path_level_init(trans, path, b);
769 return 0;
770 }
771
772 six_unlock_type(&b->c.lock, lock_type);
773 }
774 }
775
776 noinline
777 static int btree_path_prefetch(struct btree_trans *trans, struct btree_path *path)
778 {
779 struct bch_fs *c = trans->c;
780 struct btree_path_level *l = path_l(path);
781 struct btree_node_iter node_iter = l->iter;
782 struct bkey_packed *k;
783 struct bkey_buf tmp;
784 unsigned nr = test_bit(BCH_FS_STARTED, &c->flags)
785 ? (path->level > 1 ? 0 : 2)
786 : (path->level > 1 ? 1 : 16);
787 bool was_locked = btree_node_locked(path, path->level);
788 int ret = 0;
789
790 bch2_bkey_buf_init(&tmp);
791
792 while (nr-- && !ret) {
793 if (!bch2_btree_node_relock(trans, path, path->level))
794 break;
795
796 bch2_btree_node_iter_advance(&node_iter, l->b);
797 k = bch2_btree_node_iter_peek(&node_iter, l->b);
798 if (!k)
799 break;
800
801 bch2_bkey_buf_unpack(&tmp, c, l->b, k);
802 ret = bch2_btree_node_prefetch(trans, path, tmp.k, path->btree_id,
803 path->level - 1);
804 }
805
806 if (!was_locked)
807 btree_node_unlock(trans, path, path->level);
808
809 bch2_bkey_buf_exit(&tmp, c);
810 return ret;
811 }
812
813 static int btree_path_prefetch_j(struct btree_trans *trans, struct btree_path *path,
814 struct btree_and_journal_iter *jiter)
815 {
816 struct bch_fs *c = trans->c;
817 struct bkey_s_c k;
818 struct bkey_buf tmp;
819 unsigned nr = test_bit(BCH_FS_STARTED, &c->flags)
820 ? (path->level > 1 ? 0 : 2)
821 : (path->level > 1 ? 1 : 16);
822 bool was_locked = btree_node_locked(path, path->level);
823 int ret = 0;
824
825 bch2_bkey_buf_init(&tmp);
826
827 while (nr-- && !ret) {
828 if (!bch2_btree_node_relock(trans, path, path->level))
829 break;
830
831 bch2_btree_and_journal_iter_advance(jiter);
832 k = bch2_btree_and_journal_iter_peek(jiter);
833 if (!k.k)
834 break;
835
836 bch2_bkey_buf_reassemble(&tmp, c, k);
837 ret = bch2_btree_node_prefetch(trans, path, tmp.k, path->btree_id,
838 path->level - 1);
839 }
840
841 if (!was_locked)
842 btree_node_unlock(trans, path, path->level);
843
844 bch2_bkey_buf_exit(&tmp, c);
845 return ret;
846 }
847
848 static noinline void btree_node_mem_ptr_set(struct btree_trans *trans,
849 struct btree_path *path,
850 unsigned plevel, struct btree *b)
851 {
852 struct btree_path_level *l = &path->l[plevel];
853 bool locked = btree_node_locked(path, plevel);
854 struct bkey_packed *k;
855 struct bch_btree_ptr_v2 *bp;
856
857 if (!bch2_btree_node_relock(trans, path, plevel))
858 return;
859
860 k = bch2_btree_node_iter_peek_all(&l->iter, l->b);
861 BUG_ON(k->type != KEY_TYPE_btree_ptr_v2);
862
863 bp = (void *) bkeyp_val(&l->b->format, k);
864 bp->mem_ptr = (unsigned long)b;
865
866 if (!locked)
867 btree_node_unlock(trans, path, plevel);
868 }
869
870 static noinline int btree_node_iter_and_journal_peek(struct btree_trans *trans,
871 struct btree_path *path,
872 unsigned flags,
873 struct bkey_buf *out)
874 {
875 struct bch_fs *c = trans->c;
876 struct btree_path_level *l = path_l(path);
877 struct btree_and_journal_iter jiter;
878 struct bkey_s_c k;
879 int ret = 0;
880
881 __bch2_btree_and_journal_iter_init_node_iter(&jiter, c, l->b, l->iter, path->pos);
882
883 k = bch2_btree_and_journal_iter_peek(&jiter);
884
885 bch2_bkey_buf_reassemble(out, c, k);
886
887 if (flags & BTREE_ITER_PREFETCH)
888 ret = btree_path_prefetch_j(trans, path, &jiter);
889
890 bch2_btree_and_journal_iter_exit(&jiter);
891 return ret;
892 }
893
894 static __always_inline int btree_path_down(struct btree_trans *trans,
895 struct btree_path *path,
896 unsigned flags,
897 unsigned long trace_ip)
898 {
899 struct bch_fs *c = trans->c;
900 struct btree_path_level *l = path_l(path);
901 struct btree *b;
902 unsigned level = path->level - 1;
903 enum six_lock_type lock_type = __btree_lock_want(path, level);
904 struct bkey_buf tmp;
905 int ret;
906
907 EBUG_ON(!btree_node_locked(path, path->level));
908
909 bch2_bkey_buf_init(&tmp);
910
911 if (unlikely(trans->journal_replay_not_finished)) {
912 ret = btree_node_iter_and_journal_peek(trans, path, flags, &tmp);
913 if (ret)
914 goto err;
915 } else {
916 bch2_bkey_buf_unpack(&tmp, c, l->b,
917 bch2_btree_node_iter_peek(&l->iter, l->b));
918
919 if (flags & BTREE_ITER_PREFETCH) {
920 ret = btree_path_prefetch(trans, path);
921 if (ret)
922 goto err;
923 }
924 }
925
926 b = bch2_btree_node_get(trans, path, tmp.k, level, lock_type, trace_ip);
927 ret = PTR_ERR_OR_ZERO(b);
928 if (unlikely(ret))
929 goto err;
930
931 if (likely(!trans->journal_replay_not_finished &&
932 tmp.k->k.type == KEY_TYPE_btree_ptr_v2) &&
933 unlikely(b != btree_node_mem_ptr(tmp.k)))
934 btree_node_mem_ptr_set(trans, path, level + 1, b);
935
936 if (btree_node_read_locked(path, level + 1))
937 btree_node_unlock(trans, path, level + 1);
938
939 mark_btree_node_locked(trans, path, level,
940 (enum btree_node_locked_type) lock_type);
941 path->level = level;
942 bch2_btree_path_level_init(trans, path, b);
943
944 bch2_btree_path_verify_locks(path);
945 err:
946 bch2_bkey_buf_exit(&tmp, c);
947 return ret;
948 }
949
950
951 static int bch2_btree_path_traverse_all(struct btree_trans *trans)
952 {
953 struct bch_fs *c = trans->c;
954 struct btree_path *path;
955 unsigned long trace_ip = _RET_IP_;
956 int i, ret = 0;
957
958 if (trans->in_traverse_all)
959 return -BCH_ERR_transaction_restart_in_traverse_all;
960
961 trans->in_traverse_all = true;
962 retry_all:
963 trans->restarted = 0;
964 trans->last_restarted_ip = 0;
965
966 trans_for_each_path(trans, path)
967 path->should_be_locked = false;
968
969 btree_trans_sort_paths(trans);
970
971 bch2_trans_unlock(trans);
972 cond_resched();
973
974 if (unlikely(trans->memory_allocation_failure)) {
975 struct closure cl;
976
977 closure_init_stack(&cl);
978
979 do {
980 ret = bch2_btree_cache_cannibalize_lock(c, &cl);
981 closure_sync(&cl);
982 } while (ret);
983 }
984
985 /* Now, redo traversals in correct order: */
986 i = 0;
987 while (i < trans->nr_sorted) {
988 path = trans->paths + trans->sorted[i];
989
990 /*
991 * Traversing a path can cause another path to be added at about
992 * the same position:
993 */
994 if (path->uptodate) {
995 __btree_path_get(path, false);
996 ret = bch2_btree_path_traverse_one(trans, path, 0, _THIS_IP_);
997 __btree_path_put(path, false);
998
999 if (bch2_err_matches(ret, BCH_ERR_transaction_restart) ||
1000 bch2_err_matches(ret, ENOMEM))
1001 goto retry_all;
1002 if (ret)
1003 goto err;
1004 } else {
1005 i++;
1006 }
1007 }
1008
1009 /*
1010 * We used to assert that all paths had been traversed here
1011 * (path->uptodate < BTREE_ITER_NEED_TRAVERSE); however, since
1012 * path->should_be_locked is not set yet, we might have unlocked and
1013 * then failed to relock a path - that's fine.
1014 */
1015 err:
1016 bch2_btree_cache_cannibalize_unlock(c);
1017
1018 trans->in_traverse_all = false;
1019
1020 trace_and_count(c, trans_traverse_all, trans, trace_ip);
1021 return ret;
1022 }
1023
1024 static inline bool btree_path_check_pos_in_node(struct btree_path *path,
1025 unsigned l, int check_pos)
1026 {
1027 if (check_pos < 0 && btree_path_pos_before_node(path, path->l[l].b))
1028 return false;
1029 if (check_pos > 0 && btree_path_pos_after_node(path, path->l[l].b))
1030 return false;
1031 return true;
1032 }
1033
1034 static inline bool btree_path_good_node(struct btree_trans *trans,
1035 struct btree_path *path,
1036 unsigned l, int check_pos)
1037 {
1038 return is_btree_node(path, l) &&
1039 bch2_btree_node_relock(trans, path, l) &&
1040 btree_path_check_pos_in_node(path, l, check_pos);
1041 }
1042
1043 static void btree_path_set_level_down(struct btree_trans *trans,
1044 struct btree_path *path,
1045 unsigned new_level)
1046 {
1047 unsigned l;
1048
1049 path->level = new_level;
1050
1051 for (l = path->level + 1; l < BTREE_MAX_DEPTH; l++)
1052 if (btree_lock_want(path, l) == BTREE_NODE_UNLOCKED)
1053 btree_node_unlock(trans, path, l);
1054
1055 btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE);
1056 bch2_btree_path_verify(trans, path);
1057 }
1058
1059 static noinline unsigned __btree_path_up_until_good_node(struct btree_trans *trans,
1060 struct btree_path *path,
1061 int check_pos)
1062 {
1063 unsigned i, l = path->level;
1064 again:
1065 while (btree_path_node(path, l) &&
1066 !btree_path_good_node(trans, path, l, check_pos))
1067 __btree_path_set_level_up(trans, path, l++);
1068
1069 /* If we need intent locks, take them too: */
1070 for (i = l + 1;
1071 i < path->locks_want && btree_path_node(path, i);
1072 i++)
1073 if (!bch2_btree_node_relock(trans, path, i)) {
1074 while (l <= i)
1075 __btree_path_set_level_up(trans, path, l++);
1076 goto again;
1077 }
1078
1079 return l;
1080 }
1081
1082 static inline unsigned btree_path_up_until_good_node(struct btree_trans *trans,
1083 struct btree_path *path,
1084 int check_pos)
1085 {
1086 return likely(btree_node_locked(path, path->level) &&
1087 btree_path_check_pos_in_node(path, path->level, check_pos))
1088 ? path->level
1089 : __btree_path_up_until_good_node(trans, path, check_pos);
1090 }
1091
1092 /*
1093 * This is the main state machine for walking down the btree - walks down to a
1094 * specified depth
1095 *
1096 * Returns 0 on success, -EIO on error (error reading in a btree node).
1097 *
1098 * On error, caller (peek_node()/peek_key()) must return NULL; the error is
1099 * stashed in the iterator and returned from bch2_trans_exit().
1100 */
1101 int bch2_btree_path_traverse_one(struct btree_trans *trans,
1102 struct btree_path *path,
1103 unsigned flags,
1104 unsigned long trace_ip)
1105 {
1106 unsigned depth_want = path->level;
1107 int ret = -((int) trans->restarted);
1108
1109 if (unlikely(ret))
1110 goto out;
1111
1112 if (unlikely(!trans->srcu_held))
1113 bch2_trans_srcu_lock(trans);
1114
1115 /*
1116 * Ensure we obey path->should_be_locked: if it's set, we can't unlock
1117 * and re-traverse the path without a transaction restart:
1118 */
1119 if (path->should_be_locked) {
1120 ret = bch2_btree_path_relock(trans, path, trace_ip);
1121 goto out;
1122 }
1123
1124 if (path->cached) {
1125 ret = bch2_btree_path_traverse_cached(trans, path, flags);
1126 goto out;
1127 }
1128
1129 if (unlikely(path->level >= BTREE_MAX_DEPTH))
1130 goto out;
1131
1132 path->level = btree_path_up_until_good_node(trans, path, 0);
1133
1134 EBUG_ON(btree_path_node(path, path->level) &&
1135 !btree_node_locked(path, path->level));
1136
1137 /*
1138 * Note: path->nodes[path->level] may be temporarily NULL here - that
1139 * would indicate to other code that we got to the end of the btree,
1140 * here it indicates that relocking the root failed - it's critical that
1141 * btree_path_lock_root() comes next and that it can't fail
1142 */
1143 while (path->level > depth_want) {
1144 ret = btree_path_node(path, path->level)
1145 ? btree_path_down(trans, path, flags, trace_ip)
1146 : btree_path_lock_root(trans, path, depth_want, trace_ip);
1147 if (unlikely(ret)) {
1148 if (ret == 1) {
1149 /*
1150 * No nodes at this level - got to the end of
1151 * the btree:
1152 */
1153 ret = 0;
1154 goto out;
1155 }
1156
1157 __bch2_btree_path_unlock(trans, path);
1158 path->level = depth_want;
1159 path->l[path->level].b = ERR_PTR(ret);
1160 goto out;
1161 }
1162 }
1163
1164 path->uptodate = BTREE_ITER_UPTODATE;
1165 out:
1166 if (bch2_err_matches(ret, BCH_ERR_transaction_restart) != !!trans->restarted)
1167 panic("ret %s (%i) trans->restarted %s (%i)\n",
1168 bch2_err_str(ret), ret,
1169 bch2_err_str(trans->restarted), trans->restarted);
1170 bch2_btree_path_verify(trans, path);
1171 return ret;
1172 }
1173
1174 static inline void btree_path_copy(struct btree_trans *trans, struct btree_path *dst,
1175 struct btree_path *src)
1176 {
1177 unsigned i, offset = offsetof(struct btree_path, pos);
1178
1179 memcpy((void *) dst + offset,
1180 (void *) src + offset,
1181 sizeof(struct btree_path) - offset);
1182
1183 for (i = 0; i < BTREE_MAX_DEPTH; i++) {
1184 unsigned t = btree_node_locked_type(dst, i);
1185
1186 if (t != BTREE_NODE_UNLOCKED)
1187 six_lock_increment(&dst->l[i].b->c.lock, t);
1188 }
1189 }
1190
1191 static struct btree_path *btree_path_clone(struct btree_trans *trans, struct btree_path *src,
1192 bool intent)
1193 {
1194 struct btree_path *new = btree_path_alloc(trans, src);
1195
1196 btree_path_copy(trans, new, src);
1197 __btree_path_get(new, intent);
1198 return new;
1199 }
1200
1201 __flatten
1202 struct btree_path *__bch2_btree_path_make_mut(struct btree_trans *trans,
1203 struct btree_path *path, bool intent,
1204 unsigned long ip)
1205 {
1206 __btree_path_put(path, intent);
1207 path = btree_path_clone(trans, path, intent);
1208 path->preserve = false;
1209 return path;
1210 }
1211
1212 struct btree_path * __must_check
1213 __bch2_btree_path_set_pos(struct btree_trans *trans,
1214 struct btree_path *path, struct bpos new_pos,
1215 bool intent, unsigned long ip, int cmp)
1216 {
1217 unsigned level = path->level;
1218
1219 bch2_trans_verify_not_in_restart(trans);
1220 EBUG_ON(!path->ref);
1221
1222 path = bch2_btree_path_make_mut(trans, path, intent, ip);
1223
1224 path->pos = new_pos;
1225 trans->paths_sorted = false;
1226
1227 if (unlikely(path->cached)) {
1228 btree_node_unlock(trans, path, 0);
1229 path->l[0].b = ERR_PTR(-BCH_ERR_no_btree_node_up);
1230 btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE);
1231 goto out;
1232 }
1233
1234 level = btree_path_up_until_good_node(trans, path, cmp);
1235
1236 if (btree_path_node(path, level)) {
1237 struct btree_path_level *l = &path->l[level];
1238
1239 BUG_ON(!btree_node_locked(path, level));
1240 /*
1241 * We might have to skip over many keys, or just a few: try
1242 * advancing the node iterator, and if we have to skip over too
1243 * many keys just reinit it (or if we're rewinding, since that
1244 * is expensive).
1245 */
1246 if (cmp < 0 ||
1247 !btree_path_advance_to_pos(path, l, 8))
1248 bch2_btree_node_iter_init(&l->iter, l->b, &path->pos);
1249
1250 /*
1251 * Iterators to interior nodes should always be pointed at the first non
1252 * whiteout:
1253 */
1254 if (unlikely(level))
1255 bch2_btree_node_iter_peek(&l->iter, l->b);
1256 }
1257
1258 if (unlikely(level != path->level)) {
1259 btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE);
1260 __bch2_btree_path_unlock(trans, path);
1261 }
1262 out:
1263 bch2_btree_path_verify(trans, path);
1264 return path;
1265 }
1266
1267 /* Btree path: main interface: */
1268
1269 static struct btree_path *have_path_at_pos(struct btree_trans *trans, struct btree_path *path)
1270 {
1271 struct btree_path *sib;
1272
1273 sib = prev_btree_path(trans, path);
1274 if (sib && !btree_path_cmp(sib, path))
1275 return sib;
1276
1277 sib = next_btree_path(trans, path);
1278 if (sib && !btree_path_cmp(sib, path))
1279 return sib;
1280
1281 return NULL;
1282 }
1283
1284 static struct btree_path *have_node_at_pos(struct btree_trans *trans, struct btree_path *path)
1285 {
1286 struct btree_path *sib;
1287
1288 sib = prev_btree_path(trans, path);
1289 if (sib && sib->level == path->level && path_l(sib)->b == path_l(path)->b)
1290 return sib;
1291
1292 sib = next_btree_path(trans, path);
1293 if (sib && sib->level == path->level && path_l(sib)->b == path_l(path)->b)
1294 return sib;
1295
1296 return NULL;
1297 }
1298
1299 static inline void __bch2_path_free(struct btree_trans *trans, struct btree_path *path)
1300 {
1301 __bch2_btree_path_unlock(trans, path);
1302 btree_path_list_remove(trans, path);
1303 trans->paths_allocated &= ~(1ULL << path->idx);
1304 }
1305
1306 void bch2_path_put(struct btree_trans *trans, struct btree_path *path, bool intent)
1307 {
1308 struct btree_path *dup;
1309
1310 EBUG_ON(trans->paths + path->idx != path);
1311 EBUG_ON(!path->ref);
1312
1313 if (!__btree_path_put(path, intent))
1314 return;
1315
1316 dup = path->preserve
1317 ? have_path_at_pos(trans, path)
1318 : have_node_at_pos(trans, path);
1319
1320 if (!dup && !(!path->preserve && !is_btree_node(path, path->level)))
1321 return;
1322
1323 if (path->should_be_locked &&
1324 !trans->restarted &&
1325 (!dup || !bch2_btree_path_relock_norestart(trans, dup, _THIS_IP_)))
1326 return;
1327
1328 if (dup) {
1329 dup->preserve |= path->preserve;
1330 dup->should_be_locked |= path->should_be_locked;
1331 }
1332
1333 __bch2_path_free(trans, path);
1334 }
1335
1336 static void bch2_path_put_nokeep(struct btree_trans *trans, struct btree_path *path,
1337 bool intent)
1338 {
1339 EBUG_ON(trans->paths + path->idx != path);
1340 EBUG_ON(!path->ref);
1341
1342 if (!__btree_path_put(path, intent))
1343 return;
1344
1345 __bch2_path_free(trans, path);
1346 }
1347
1348 void __noreturn bch2_trans_restart_error(struct btree_trans *trans, u32 restart_count)
1349 {
1350 panic("trans->restart_count %u, should be %u, last restarted by %pS\n",
1351 trans->restart_count, restart_count,
1352 (void *) trans->last_begin_ip);
1353 }
1354
1355 void __noreturn bch2_trans_in_restart_error(struct btree_trans *trans)
1356 {
1357 panic("in transaction restart: %s, last restarted by %pS\n",
1358 bch2_err_str(trans->restarted),
1359 (void *) trans->last_restarted_ip);
1360 }
1361
1362 noinline __cold
1363 void bch2_trans_updates_to_text(struct printbuf *buf, struct btree_trans *trans)
1364 {
1365 struct btree_insert_entry *i;
1366 struct btree_write_buffered_key *wb;
1367
1368 prt_printf(buf, "transaction updates for %s journal seq %llu",
1369 trans->fn, trans->journal_res.seq);
1370 prt_newline(buf);
1371 printbuf_indent_add(buf, 2);
1372
1373 trans_for_each_update(trans, i) {
1374 struct bkey_s_c old = { &i->old_k, i->old_v };
1375
1376 prt_printf(buf, "update: btree=%s cached=%u %pS",
1377 bch2_btree_id_str(i->btree_id),
1378 i->cached,
1379 (void *) i->ip_allocated);
1380 prt_newline(buf);
1381
1382 prt_printf(buf, " old ");
1383 bch2_bkey_val_to_text(buf, trans->c, old);
1384 prt_newline(buf);
1385
1386 prt_printf(buf, " new ");
1387 bch2_bkey_val_to_text(buf, trans->c, bkey_i_to_s_c(i->k));
1388 prt_newline(buf);
1389 }
1390
1391 trans_for_each_wb_update(trans, wb) {
1392 prt_printf(buf, "update: btree=%s wb=1 %pS",
1393 bch2_btree_id_str(wb->btree),
1394 (void *) i->ip_allocated);
1395 prt_newline(buf);
1396
1397 prt_printf(buf, " new ");
1398 bch2_bkey_val_to_text(buf, trans->c, bkey_i_to_s_c(&wb->k));
1399 prt_newline(buf);
1400 }
1401
1402 printbuf_indent_sub(buf, 2);
1403 }
1404
1405 noinline __cold
1406 void bch2_dump_trans_updates(struct btree_trans *trans)
1407 {
1408 struct printbuf buf = PRINTBUF;
1409
1410 bch2_trans_updates_to_text(&buf, trans);
1411 bch2_print_string_as_lines(KERN_ERR, buf.buf);
1412 printbuf_exit(&buf);
1413 }
1414
1415 noinline __cold
1416 void bch2_btree_path_to_text(struct printbuf *out, struct btree_path *path)
1417 {
1418 prt_printf(out, "path: idx %2u ref %u:%u %c %c btree=%s l=%u pos ",
1419 path->idx, path->ref, path->intent_ref,
1420 path->preserve ? 'P' : ' ',
1421 path->should_be_locked ? 'S' : ' ',
1422 bch2_btree_id_str(path->btree_id),
1423 path->level);
1424 bch2_bpos_to_text(out, path->pos);
1425
1426 prt_printf(out, " locks %u", path->nodes_locked);
1427 #ifdef TRACK_PATH_ALLOCATED
1428 prt_printf(out, " %pS", (void *) path->ip_allocated);
1429 #endif
1430 prt_newline(out);
1431 }
1432
1433 static noinline __cold
1434 void __bch2_trans_paths_to_text(struct printbuf *out, struct btree_trans *trans,
1435 bool nosort)
1436 {
1437 struct btree_path *path;
1438 unsigned idx;
1439
1440 if (!nosort)
1441 btree_trans_sort_paths(trans);
1442
1443 trans_for_each_path_inorder(trans, path, idx)
1444 bch2_btree_path_to_text(out, path);
1445 }
1446
1447 noinline __cold
1448 void bch2_trans_paths_to_text(struct printbuf *out, struct btree_trans *trans)
1449 {
1450 __bch2_trans_paths_to_text(out, trans, false);
1451 }
1452
1453 static noinline __cold
1454 void __bch2_dump_trans_paths_updates(struct btree_trans *trans, bool nosort)
1455 {
1456 struct printbuf buf = PRINTBUF;
1457
1458 __bch2_trans_paths_to_text(&buf, trans, nosort);
1459 bch2_trans_updates_to_text(&buf, trans);
1460
1461 bch2_print_string_as_lines(KERN_ERR, buf.buf);
1462 printbuf_exit(&buf);
1463 }
1464
1465 noinline __cold
1466 void bch2_dump_trans_paths_updates(struct btree_trans *trans)
1467 {
1468 __bch2_dump_trans_paths_updates(trans, false);
1469 }
1470
1471 noinline __cold
1472 static void bch2_trans_update_max_paths(struct btree_trans *trans)
1473 {
1474 struct btree_transaction_stats *s = btree_trans_stats(trans);
1475 struct printbuf buf = PRINTBUF;
1476
1477 if (!s)
1478 return;
1479
1480 bch2_trans_paths_to_text(&buf, trans);
1481
1482 if (!buf.allocation_failure) {
1483 mutex_lock(&s->lock);
1484 if (s->nr_max_paths < hweight64(trans->paths_allocated)) {
1485 s->nr_max_paths = trans->nr_max_paths =
1486 hweight64(trans->paths_allocated);
1487 swap(s->max_paths_text, buf.buf);
1488 }
1489 mutex_unlock(&s->lock);
1490 }
1491
1492 printbuf_exit(&buf);
1493
1494 trans->nr_max_paths = hweight64(trans->paths_allocated);
1495 }
1496
1497 static noinline void btree_path_overflow(struct btree_trans *trans)
1498 {
1499 bch2_dump_trans_paths_updates(trans);
1500 panic("trans path overflow\n");
1501 }
1502
1503 static inline struct btree_path *btree_path_alloc(struct btree_trans *trans,
1504 struct btree_path *pos)
1505 {
1506 struct btree_path *path;
1507 unsigned idx;
1508
1509 if (unlikely(trans->paths_allocated ==
1510 ~((~0ULL << 1) << (BTREE_ITER_MAX - 1))))
1511 btree_path_overflow(trans);
1512
1513 idx = __ffs64(~trans->paths_allocated);
1514
1515 /*
1516 * Do this before marking the new path as allocated, since it won't be
1517 * initialized yet:
1518 */
1519 if (unlikely(idx > trans->nr_max_paths))
1520 bch2_trans_update_max_paths(trans);
1521
1522 trans->paths_allocated |= 1ULL << idx;
1523
1524 path = &trans->paths[idx];
1525 path->idx = idx;
1526 path->ref = 0;
1527 path->intent_ref = 0;
1528 path->nodes_locked = 0;
1529 path->alloc_seq++;
1530
1531 btree_path_list_add(trans, pos, path);
1532 trans->paths_sorted = false;
1533 return path;
1534 }
1535
1536 struct btree_path *bch2_path_get(struct btree_trans *trans,
1537 enum btree_id btree_id, struct bpos pos,
1538 unsigned locks_want, unsigned level,
1539 unsigned flags, unsigned long ip)
1540 {
1541 struct btree_path *path, *path_pos = NULL;
1542 bool cached = flags & BTREE_ITER_CACHED;
1543 bool intent = flags & BTREE_ITER_INTENT;
1544 int i;
1545
1546 bch2_trans_verify_not_in_restart(trans);
1547 bch2_trans_verify_locks(trans);
1548
1549 btree_trans_sort_paths(trans);
1550
1551 trans_for_each_path_inorder(trans, path, i) {
1552 if (__btree_path_cmp(path,
1553 btree_id,
1554 cached,
1555 pos,
1556 level) > 0)
1557 break;
1558
1559 path_pos = path;
1560 }
1561
1562 if (path_pos &&
1563 path_pos->cached == cached &&
1564 path_pos->btree_id == btree_id &&
1565 path_pos->level == level) {
1566 __btree_path_get(path_pos, intent);
1567 path = bch2_btree_path_set_pos(trans, path_pos, pos, intent, ip);
1568 } else {
1569 path = btree_path_alloc(trans, path_pos);
1570 path_pos = NULL;
1571
1572 __btree_path_get(path, intent);
1573 path->pos = pos;
1574 path->btree_id = btree_id;
1575 path->cached = cached;
1576 path->uptodate = BTREE_ITER_NEED_TRAVERSE;
1577 path->should_be_locked = false;
1578 path->level = level;
1579 path->locks_want = locks_want;
1580 path->nodes_locked = 0;
1581 for (i = 0; i < ARRAY_SIZE(path->l); i++)
1582 path->l[i].b = ERR_PTR(-BCH_ERR_no_btree_node_init);
1583 #ifdef TRACK_PATH_ALLOCATED
1584 path->ip_allocated = ip;
1585 #endif
1586 trans->paths_sorted = false;
1587 }
1588
1589 if (!(flags & BTREE_ITER_NOPRESERVE))
1590 path->preserve = true;
1591
1592 if (path->intent_ref)
1593 locks_want = max(locks_want, level + 1);
1594
1595 /*
1596 * If the path has locks_want greater than requested, we don't downgrade
1597 * it here - on transaction restart because btree node split needs to
1598 * upgrade locks, we might be putting/getting the iterator again.
1599 * Downgrading iterators only happens via bch2_trans_downgrade(), after
1600 * a successful transaction commit.
1601 */
1602
1603 locks_want = min(locks_want, BTREE_MAX_DEPTH);
1604 if (locks_want > path->locks_want)
1605 bch2_btree_path_upgrade_noupgrade_sibs(trans, path, locks_want, NULL);
1606
1607 return path;
1608 }
1609
1610 struct bkey_s_c bch2_btree_path_peek_slot(struct btree_path *path, struct bkey *u)
1611 {
1612
1613 struct btree_path_level *l = path_l(path);
1614 struct bkey_packed *_k;
1615 struct bkey_s_c k;
1616
1617 if (unlikely(!l->b))
1618 return bkey_s_c_null;
1619
1620 EBUG_ON(path->uptodate != BTREE_ITER_UPTODATE);
1621 EBUG_ON(!btree_node_locked(path, path->level));
1622
1623 if (!path->cached) {
1624 _k = bch2_btree_node_iter_peek_all(&l->iter, l->b);
1625 k = _k ? bkey_disassemble(l->b, _k, u) : bkey_s_c_null;
1626
1627 EBUG_ON(k.k && bkey_deleted(k.k) && bpos_eq(k.k->p, path->pos));
1628
1629 if (!k.k || !bpos_eq(path->pos, k.k->p))
1630 goto hole;
1631 } else {
1632 struct bkey_cached *ck = (void *) path->l[0].b;
1633
1634 EBUG_ON(ck &&
1635 (path->btree_id != ck->key.btree_id ||
1636 !bkey_eq(path->pos, ck->key.pos)));
1637 if (!ck || !ck->valid)
1638 return bkey_s_c_null;
1639
1640 *u = ck->k->k;
1641 k = bkey_i_to_s_c(ck->k);
1642 }
1643
1644 return k;
1645 hole:
1646 bkey_init(u);
1647 u->p = path->pos;
1648 return (struct bkey_s_c) { u, NULL };
1649 }
1650
1651 /* Btree iterators: */
1652
1653 int __must_check
1654 __bch2_btree_iter_traverse(struct btree_iter *iter)
1655 {
1656 return bch2_btree_path_traverse(iter->trans, iter->path, iter->flags);
1657 }
1658
1659 int __must_check
1660 bch2_btree_iter_traverse(struct btree_iter *iter)
1661 {
1662 int ret;
1663
1664 iter->path = bch2_btree_path_set_pos(iter->trans, iter->path,
1665 btree_iter_search_key(iter),
1666 iter->flags & BTREE_ITER_INTENT,
1667 btree_iter_ip_allocated(iter));
1668
1669 ret = bch2_btree_path_traverse(iter->trans, iter->path, iter->flags);
1670 if (ret)
1671 return ret;
1672
1673 btree_path_set_should_be_locked(iter->path);
1674 return 0;
1675 }
1676
1677 /* Iterate across nodes (leaf and interior nodes) */
1678
1679 struct btree *bch2_btree_iter_peek_node(struct btree_iter *iter)
1680 {
1681 struct btree_trans *trans = iter->trans;
1682 struct btree *b = NULL;
1683 int ret;
1684
1685 EBUG_ON(iter->path->cached);
1686 bch2_btree_iter_verify(iter);
1687
1688 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
1689 if (ret)
1690 goto err;
1691
1692 b = btree_path_node(iter->path, iter->path->level);
1693 if (!b)
1694 goto out;
1695
1696 BUG_ON(bpos_lt(b->key.k.p, iter->pos));
1697
1698 bkey_init(&iter->k);
1699 iter->k.p = iter->pos = b->key.k.p;
1700
1701 iter->path = bch2_btree_path_set_pos(trans, iter->path, b->key.k.p,
1702 iter->flags & BTREE_ITER_INTENT,
1703 btree_iter_ip_allocated(iter));
1704 btree_path_set_should_be_locked(iter->path);
1705 out:
1706 bch2_btree_iter_verify_entry_exit(iter);
1707 bch2_btree_iter_verify(iter);
1708
1709 return b;
1710 err:
1711 b = ERR_PTR(ret);
1712 goto out;
1713 }
1714
1715 struct btree *bch2_btree_iter_peek_node_and_restart(struct btree_iter *iter)
1716 {
1717 struct btree *b;
1718
1719 while (b = bch2_btree_iter_peek_node(iter),
1720 bch2_err_matches(PTR_ERR_OR_ZERO(b), BCH_ERR_transaction_restart))
1721 bch2_trans_begin(iter->trans);
1722
1723 return b;
1724 }
1725
1726 struct btree *bch2_btree_iter_next_node(struct btree_iter *iter)
1727 {
1728 struct btree_trans *trans = iter->trans;
1729 struct btree_path *path = iter->path;
1730 struct btree *b = NULL;
1731 int ret;
1732
1733 bch2_trans_verify_not_in_restart(trans);
1734 EBUG_ON(iter->path->cached);
1735 bch2_btree_iter_verify(iter);
1736
1737 /* already at end? */
1738 if (!btree_path_node(path, path->level))
1739 return NULL;
1740
1741 /* got to end? */
1742 if (!btree_path_node(path, path->level + 1)) {
1743 btree_path_set_level_up(trans, path);
1744 return NULL;
1745 }
1746
1747 if (!bch2_btree_node_relock(trans, path, path->level + 1)) {
1748 __bch2_btree_path_unlock(trans, path);
1749 path->l[path->level].b = ERR_PTR(-BCH_ERR_no_btree_node_relock);
1750 path->l[path->level + 1].b = ERR_PTR(-BCH_ERR_no_btree_node_relock);
1751 btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE);
1752 trace_and_count(trans->c, trans_restart_relock_next_node, trans, _THIS_IP_, path);
1753 ret = btree_trans_restart(trans, BCH_ERR_transaction_restart_relock);
1754 goto err;
1755 }
1756
1757 b = btree_path_node(path, path->level + 1);
1758
1759 if (bpos_eq(iter->pos, b->key.k.p)) {
1760 __btree_path_set_level_up(trans, path, path->level++);
1761 } else {
1762 /*
1763 * Haven't gotten to the end of the parent node: go back down to
1764 * the next child node
1765 */
1766 path = iter->path =
1767 bch2_btree_path_set_pos(trans, path, bpos_successor(iter->pos),
1768 iter->flags & BTREE_ITER_INTENT,
1769 btree_iter_ip_allocated(iter));
1770
1771 btree_path_set_level_down(trans, path, iter->min_depth);
1772
1773 ret = bch2_btree_path_traverse(trans, path, iter->flags);
1774 if (ret)
1775 goto err;
1776
1777 b = path->l[path->level].b;
1778 }
1779
1780 bkey_init(&iter->k);
1781 iter->k.p = iter->pos = b->key.k.p;
1782
1783 iter->path = bch2_btree_path_set_pos(trans, iter->path, b->key.k.p,
1784 iter->flags & BTREE_ITER_INTENT,
1785 btree_iter_ip_allocated(iter));
1786 btree_path_set_should_be_locked(iter->path);
1787 BUG_ON(iter->path->uptodate);
1788 out:
1789 bch2_btree_iter_verify_entry_exit(iter);
1790 bch2_btree_iter_verify(iter);
1791
1792 return b;
1793 err:
1794 b = ERR_PTR(ret);
1795 goto out;
1796 }
1797
1798 /* Iterate across keys (in leaf nodes only) */
1799
1800 inline bool bch2_btree_iter_advance(struct btree_iter *iter)
1801 {
1802 if (likely(!(iter->flags & BTREE_ITER_ALL_LEVELS))) {
1803 struct bpos pos = iter->k.p;
1804 bool ret = !(iter->flags & BTREE_ITER_ALL_SNAPSHOTS
1805 ? bpos_eq(pos, SPOS_MAX)
1806 : bkey_eq(pos, SPOS_MAX));
1807
1808 if (ret && !(iter->flags & BTREE_ITER_IS_EXTENTS))
1809 pos = bkey_successor(iter, pos);
1810 bch2_btree_iter_set_pos(iter, pos);
1811 return ret;
1812 } else {
1813 if (!btree_path_node(iter->path, iter->path->level))
1814 return true;
1815
1816 iter->advanced = true;
1817 return false;
1818 }
1819 }
1820
1821 inline bool bch2_btree_iter_rewind(struct btree_iter *iter)
1822 {
1823 struct bpos pos = bkey_start_pos(&iter->k);
1824 bool ret = !(iter->flags & BTREE_ITER_ALL_SNAPSHOTS
1825 ? bpos_eq(pos, POS_MIN)
1826 : bkey_eq(pos, POS_MIN));
1827
1828 if (ret && !(iter->flags & BTREE_ITER_IS_EXTENTS))
1829 pos = bkey_predecessor(iter, pos);
1830 bch2_btree_iter_set_pos(iter, pos);
1831 return ret;
1832 }
1833
1834 static noinline
1835 struct bkey_i *__bch2_btree_trans_peek_updates(struct btree_iter *iter)
1836 {
1837 struct btree_insert_entry *i;
1838 struct bkey_i *ret = NULL;
1839
1840 trans_for_each_update(iter->trans, i) {
1841 if (i->btree_id < iter->btree_id)
1842 continue;
1843 if (i->btree_id > iter->btree_id)
1844 break;
1845 if (bpos_lt(i->k->k.p, iter->path->pos))
1846 continue;
1847 if (i->key_cache_already_flushed)
1848 continue;
1849 if (!ret || bpos_lt(i->k->k.p, ret->k.p))
1850 ret = i->k;
1851 }
1852
1853 return ret;
1854 }
1855
1856 static inline struct bkey_i *btree_trans_peek_updates(struct btree_iter *iter)
1857 {
1858 return iter->flags & BTREE_ITER_WITH_UPDATES
1859 ? __bch2_btree_trans_peek_updates(iter)
1860 : NULL;
1861 }
1862
1863 static struct bkey_i *bch2_btree_journal_peek(struct btree_trans *trans,
1864 struct btree_iter *iter,
1865 struct bpos end_pos)
1866 {
1867 struct bkey_i *k;
1868
1869 if (bpos_lt(iter->path->pos, iter->journal_pos))
1870 iter->journal_idx = 0;
1871
1872 k = bch2_journal_keys_peek_upto(trans->c, iter->btree_id,
1873 iter->path->level,
1874 iter->path->pos,
1875 end_pos,
1876 &iter->journal_idx);
1877
1878 iter->journal_pos = k ? k->k.p : end_pos;
1879 return k;
1880 }
1881
1882 static noinline
1883 struct bkey_s_c btree_trans_peek_slot_journal(struct btree_trans *trans,
1884 struct btree_iter *iter)
1885 {
1886 struct bkey_i *k = bch2_btree_journal_peek(trans, iter, iter->path->pos);
1887
1888 if (k) {
1889 iter->k = k->k;
1890 return bkey_i_to_s_c(k);
1891 } else {
1892 return bkey_s_c_null;
1893 }
1894 }
1895
1896 static noinline
1897 struct bkey_s_c btree_trans_peek_journal(struct btree_trans *trans,
1898 struct btree_iter *iter,
1899 struct bkey_s_c k)
1900 {
1901 struct bkey_i *next_journal =
1902 bch2_btree_journal_peek(trans, iter,
1903 k.k ? k.k->p : path_l(iter->path)->b->key.k.p);
1904
1905 if (next_journal) {
1906 iter->k = next_journal->k;
1907 k = bkey_i_to_s_c(next_journal);
1908 }
1909
1910 return k;
1911 }
1912
1913 /*
1914 * Checks btree key cache for key at iter->pos and returns it if present, or
1915 * bkey_s_c_null:
1916 */
1917 static noinline
1918 struct bkey_s_c btree_trans_peek_key_cache(struct btree_iter *iter, struct bpos pos)
1919 {
1920 struct btree_trans *trans = iter->trans;
1921 struct bch_fs *c = trans->c;
1922 struct bkey u;
1923 struct bkey_s_c k;
1924 int ret;
1925
1926 if ((iter->flags & BTREE_ITER_KEY_CACHE_FILL) &&
1927 bpos_eq(iter->pos, pos))
1928 return bkey_s_c_null;
1929
1930 if (!bch2_btree_key_cache_find(c, iter->btree_id, pos))
1931 return bkey_s_c_null;
1932
1933 if (!iter->key_cache_path)
1934 iter->key_cache_path = bch2_path_get(trans, iter->btree_id, pos,
1935 iter->flags & BTREE_ITER_INTENT, 0,
1936 iter->flags|BTREE_ITER_CACHED|
1937 BTREE_ITER_CACHED_NOFILL,
1938 _THIS_IP_);
1939
1940 iter->key_cache_path = bch2_btree_path_set_pos(trans, iter->key_cache_path, pos,
1941 iter->flags & BTREE_ITER_INTENT,
1942 btree_iter_ip_allocated(iter));
1943
1944 ret = bch2_btree_path_traverse(trans, iter->key_cache_path,
1945 iter->flags|BTREE_ITER_CACHED) ?:
1946 bch2_btree_path_relock(trans, iter->path, _THIS_IP_);
1947 if (unlikely(ret))
1948 return bkey_s_c_err(ret);
1949
1950 btree_path_set_should_be_locked(iter->key_cache_path);
1951
1952 k = bch2_btree_path_peek_slot(iter->key_cache_path, &u);
1953 if (k.k && !bkey_err(k)) {
1954 iter->k = u;
1955 k.k = &iter->k;
1956 }
1957 return k;
1958 }
1959
1960 static struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter, struct bpos search_key)
1961 {
1962 struct btree_trans *trans = iter->trans;
1963 struct bkey_i *next_update;
1964 struct bkey_s_c k, k2;
1965 int ret;
1966
1967 EBUG_ON(iter->path->cached);
1968 bch2_btree_iter_verify(iter);
1969
1970 while (1) {
1971 struct btree_path_level *l;
1972
1973 iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key,
1974 iter->flags & BTREE_ITER_INTENT,
1975 btree_iter_ip_allocated(iter));
1976
1977 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
1978 if (unlikely(ret)) {
1979 /* ensure that iter->k is consistent with iter->pos: */
1980 bch2_btree_iter_set_pos(iter, iter->pos);
1981 k = bkey_s_c_err(ret);
1982 goto out;
1983 }
1984
1985 l = path_l(iter->path);
1986
1987 if (unlikely(!l->b)) {
1988 /* No btree nodes at requested level: */
1989 bch2_btree_iter_set_pos(iter, SPOS_MAX);
1990 k = bkey_s_c_null;
1991 goto out;
1992 }
1993
1994 btree_path_set_should_be_locked(iter->path);
1995
1996 k = btree_path_level_peek_all(trans->c, l, &iter->k);
1997
1998 if (unlikely(iter->flags & BTREE_ITER_WITH_KEY_CACHE) &&
1999 k.k &&
2000 (k2 = btree_trans_peek_key_cache(iter, k.k->p)).k) {
2001 k = k2;
2002 ret = bkey_err(k);
2003 if (ret) {
2004 bch2_btree_iter_set_pos(iter, iter->pos);
2005 goto out;
2006 }
2007 }
2008
2009 if (unlikely(iter->flags & BTREE_ITER_WITH_JOURNAL))
2010 k = btree_trans_peek_journal(trans, iter, k);
2011
2012 next_update = btree_trans_peek_updates(iter);
2013
2014 if (next_update &&
2015 bpos_le(next_update->k.p,
2016 k.k ? k.k->p : l->b->key.k.p)) {
2017 iter->k = next_update->k;
2018 k = bkey_i_to_s_c(next_update);
2019 }
2020
2021 if (k.k && bkey_deleted(k.k)) {
2022 /*
2023 * If we've got a whiteout, and it's after the search
2024 * key, advance the search key to the whiteout instead
2025 * of just after the whiteout - it might be a btree
2026 * whiteout, with a real key at the same position, since
2027 * in the btree deleted keys sort before non deleted.
2028 */
2029 search_key = !bpos_eq(search_key, k.k->p)
2030 ? k.k->p
2031 : bpos_successor(k.k->p);
2032 continue;
2033 }
2034
2035 if (likely(k.k)) {
2036 break;
2037 } else if (likely(!bpos_eq(l->b->key.k.p, SPOS_MAX))) {
2038 /* Advance to next leaf node: */
2039 search_key = bpos_successor(l->b->key.k.p);
2040 } else {
2041 /* End of btree: */
2042 bch2_btree_iter_set_pos(iter, SPOS_MAX);
2043 k = bkey_s_c_null;
2044 goto out;
2045 }
2046 }
2047 out:
2048 bch2_btree_iter_verify(iter);
2049
2050 return k;
2051 }
2052
2053 /**
2054 * bch2_btree_iter_peek_upto() - returns first key greater than or equal to
2055 * iterator's current position
2056 * @iter: iterator to peek from
2057 * @end: search limit: returns keys less than or equal to @end
2058 *
2059 * Returns: key if found, or an error extractable with bkey_err().
2060 */
2061 struct bkey_s_c bch2_btree_iter_peek_upto(struct btree_iter *iter, struct bpos end)
2062 {
2063 struct btree_trans *trans = iter->trans;
2064 struct bpos search_key = btree_iter_search_key(iter);
2065 struct bkey_s_c k;
2066 struct bpos iter_pos;
2067 int ret;
2068
2069 EBUG_ON(iter->flags & BTREE_ITER_ALL_LEVELS);
2070 EBUG_ON((iter->flags & BTREE_ITER_FILTER_SNAPSHOTS) && bkey_eq(end, POS_MAX));
2071
2072 if (iter->update_path) {
2073 bch2_path_put_nokeep(trans, iter->update_path,
2074 iter->flags & BTREE_ITER_INTENT);
2075 iter->update_path = NULL;
2076 }
2077
2078 bch2_btree_iter_verify_entry_exit(iter);
2079
2080 while (1) {
2081 k = __bch2_btree_iter_peek(iter, search_key);
2082 if (unlikely(!k.k))
2083 goto end;
2084 if (unlikely(bkey_err(k)))
2085 goto out_no_locked;
2086
2087 /*
2088 * iter->pos should be mononotically increasing, and always be
2089 * equal to the key we just returned - except extents can
2090 * straddle iter->pos:
2091 */
2092 if (!(iter->flags & BTREE_ITER_IS_EXTENTS))
2093 iter_pos = k.k->p;
2094 else
2095 iter_pos = bkey_max(iter->pos, bkey_start_pos(k.k));
2096
2097 if (unlikely(!(iter->flags & BTREE_ITER_IS_EXTENTS)
2098 ? bkey_gt(iter_pos, end)
2099 : bkey_ge(iter_pos, end)))
2100 goto end;
2101
2102 if (iter->update_path &&
2103 !bkey_eq(iter->update_path->pos, k.k->p)) {
2104 bch2_path_put_nokeep(trans, iter->update_path,
2105 iter->flags & BTREE_ITER_INTENT);
2106 iter->update_path = NULL;
2107 }
2108
2109 if ((iter->flags & BTREE_ITER_FILTER_SNAPSHOTS) &&
2110 (iter->flags & BTREE_ITER_INTENT) &&
2111 !(iter->flags & BTREE_ITER_IS_EXTENTS) &&
2112 !iter->update_path) {
2113 struct bpos pos = k.k->p;
2114
2115 if (pos.snapshot < iter->snapshot) {
2116 search_key = bpos_successor(k.k->p);
2117 continue;
2118 }
2119
2120 pos.snapshot = iter->snapshot;
2121
2122 /*
2123 * advance, same as on exit for iter->path, but only up
2124 * to snapshot
2125 */
2126 __btree_path_get(iter->path, iter->flags & BTREE_ITER_INTENT);
2127 iter->update_path = iter->path;
2128
2129 iter->update_path = bch2_btree_path_set_pos(trans,
2130 iter->update_path, pos,
2131 iter->flags & BTREE_ITER_INTENT,
2132 _THIS_IP_);
2133 ret = bch2_btree_path_traverse(trans, iter->update_path, iter->flags);
2134 if (unlikely(ret)) {
2135 k = bkey_s_c_err(ret);
2136 goto out_no_locked;
2137 }
2138 }
2139
2140 /*
2141 * We can never have a key in a leaf node at POS_MAX, so
2142 * we don't have to check these successor() calls:
2143 */
2144 if ((iter->flags & BTREE_ITER_FILTER_SNAPSHOTS) &&
2145 !bch2_snapshot_is_ancestor(trans->c,
2146 iter->snapshot,
2147 k.k->p.snapshot)) {
2148 search_key = bpos_successor(k.k->p);
2149 continue;
2150 }
2151
2152 if (bkey_whiteout(k.k) &&
2153 !(iter->flags & BTREE_ITER_ALL_SNAPSHOTS)) {
2154 search_key = bkey_successor(iter, k.k->p);
2155 continue;
2156 }
2157
2158 break;
2159 }
2160
2161 iter->pos = iter_pos;
2162
2163 iter->path = bch2_btree_path_set_pos(trans, iter->path, k.k->p,
2164 iter->flags & BTREE_ITER_INTENT,
2165 btree_iter_ip_allocated(iter));
2166
2167 btree_path_set_should_be_locked(iter->path);
2168 out_no_locked:
2169 if (iter->update_path) {
2170 ret = bch2_btree_path_relock(trans, iter->update_path, _THIS_IP_);
2171 if (unlikely(ret))
2172 k = bkey_s_c_err(ret);
2173 else
2174 btree_path_set_should_be_locked(iter->update_path);
2175 }
2176
2177 if (!(iter->flags & BTREE_ITER_ALL_SNAPSHOTS))
2178 iter->pos.snapshot = iter->snapshot;
2179
2180 ret = bch2_btree_iter_verify_ret(iter, k);
2181 if (unlikely(ret)) {
2182 bch2_btree_iter_set_pos(iter, iter->pos);
2183 k = bkey_s_c_err(ret);
2184 }
2185
2186 bch2_btree_iter_verify_entry_exit(iter);
2187
2188 return k;
2189 end:
2190 bch2_btree_iter_set_pos(iter, end);
2191 k = bkey_s_c_null;
2192 goto out_no_locked;
2193 }
2194
2195 /**
2196 * bch2_btree_iter_peek_all_levels() - returns the first key greater than or
2197 * equal to iterator's current position, returning keys from every level of the
2198 * btree. For keys at different levels of the btree that compare equal, the key
2199 * from the lower level (leaf) is returned first.
2200 * @iter: iterator to peek from
2201 *
2202 * Returns: key if found, or an error extractable with bkey_err().
2203 */
2204 struct bkey_s_c bch2_btree_iter_peek_all_levels(struct btree_iter *iter)
2205 {
2206 struct btree_trans *trans = iter->trans;
2207 struct bkey_s_c k;
2208 int ret;
2209
2210 EBUG_ON(iter->path->cached);
2211 bch2_btree_iter_verify(iter);
2212 BUG_ON(iter->path->level < iter->min_depth);
2213 BUG_ON(!(iter->flags & BTREE_ITER_ALL_SNAPSHOTS));
2214 EBUG_ON(!(iter->flags & BTREE_ITER_ALL_LEVELS));
2215
2216 while (1) {
2217 iter->path = bch2_btree_path_set_pos(trans, iter->path, iter->pos,
2218 iter->flags & BTREE_ITER_INTENT,
2219 btree_iter_ip_allocated(iter));
2220
2221 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
2222 if (unlikely(ret)) {
2223 /* ensure that iter->k is consistent with iter->pos: */
2224 bch2_btree_iter_set_pos(iter, iter->pos);
2225 k = bkey_s_c_err(ret);
2226 goto out_no_locked;
2227 }
2228
2229 /* Already at end? */
2230 if (!btree_path_node(iter->path, iter->path->level)) {
2231 k = bkey_s_c_null;
2232 goto out_no_locked;
2233 }
2234
2235 k = btree_path_level_peek_all(trans->c,
2236 &iter->path->l[iter->path->level], &iter->k);
2237
2238 /* Check if we should go up to the parent node: */
2239 if (!k.k ||
2240 (iter->advanced &&
2241 bpos_eq(path_l(iter->path)->b->key.k.p, iter->pos))) {
2242 iter->pos = path_l(iter->path)->b->key.k.p;
2243 btree_path_set_level_up(trans, iter->path);
2244 iter->advanced = false;
2245 continue;
2246 }
2247
2248 /*
2249 * Check if we should go back down to a leaf:
2250 * If we're not in a leaf node, we only return the current key
2251 * if it exactly matches iter->pos - otherwise we first have to
2252 * go back to the leaf:
2253 */
2254 if (iter->path->level != iter->min_depth &&
2255 (iter->advanced ||
2256 !k.k ||
2257 !bpos_eq(iter->pos, k.k->p))) {
2258 btree_path_set_level_down(trans, iter->path, iter->min_depth);
2259 iter->pos = bpos_successor(iter->pos);
2260 iter->advanced = false;
2261 continue;
2262 }
2263
2264 /* Check if we should go to the next key: */
2265 if (iter->path->level == iter->min_depth &&
2266 iter->advanced &&
2267 k.k &&
2268 bpos_eq(iter->pos, k.k->p)) {
2269 iter->pos = bpos_successor(iter->pos);
2270 iter->advanced = false;
2271 continue;
2272 }
2273
2274 if (iter->advanced &&
2275 iter->path->level == iter->min_depth &&
2276 !bpos_eq(k.k->p, iter->pos))
2277 iter->advanced = false;
2278
2279 BUG_ON(iter->advanced);
2280 BUG_ON(!k.k);
2281 break;
2282 }
2283
2284 iter->pos = k.k->p;
2285 btree_path_set_should_be_locked(iter->path);
2286 out_no_locked:
2287 bch2_btree_iter_verify(iter);
2288
2289 return k;
2290 }
2291
2292 /**
2293 * bch2_btree_iter_next() - returns first key greater than iterator's current
2294 * position
2295 * @iter: iterator to peek from
2296 *
2297 * Returns: key if found, or an error extractable with bkey_err().
2298 */
2299 struct bkey_s_c bch2_btree_iter_next(struct btree_iter *iter)
2300 {
2301 if (!bch2_btree_iter_advance(iter))
2302 return bkey_s_c_null;
2303
2304 return bch2_btree_iter_peek(iter);
2305 }
2306
2307 /**
2308 * bch2_btree_iter_peek_prev() - returns first key less than or equal to
2309 * iterator's current position
2310 * @iter: iterator to peek from
2311 *
2312 * Returns: key if found, or an error extractable with bkey_err().
2313 */
2314 struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *iter)
2315 {
2316 struct btree_trans *trans = iter->trans;
2317 struct bpos search_key = iter->pos;
2318 struct btree_path *saved_path = NULL;
2319 struct bkey_s_c k;
2320 struct bkey saved_k;
2321 const struct bch_val *saved_v;
2322 int ret;
2323
2324 EBUG_ON(iter->path->cached || iter->path->level);
2325 EBUG_ON(iter->flags & BTREE_ITER_WITH_UPDATES);
2326
2327 if (iter->flags & BTREE_ITER_WITH_JOURNAL)
2328 return bkey_s_c_err(-EIO);
2329
2330 bch2_btree_iter_verify(iter);
2331 bch2_btree_iter_verify_entry_exit(iter);
2332
2333 if (iter->flags & BTREE_ITER_FILTER_SNAPSHOTS)
2334 search_key.snapshot = U32_MAX;
2335
2336 while (1) {
2337 iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key,
2338 iter->flags & BTREE_ITER_INTENT,
2339 btree_iter_ip_allocated(iter));
2340
2341 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
2342 if (unlikely(ret)) {
2343 /* ensure that iter->k is consistent with iter->pos: */
2344 bch2_btree_iter_set_pos(iter, iter->pos);
2345 k = bkey_s_c_err(ret);
2346 goto out_no_locked;
2347 }
2348
2349 k = btree_path_level_peek(trans, iter->path,
2350 &iter->path->l[0], &iter->k);
2351 if (!k.k ||
2352 ((iter->flags & BTREE_ITER_IS_EXTENTS)
2353 ? bpos_ge(bkey_start_pos(k.k), search_key)
2354 : bpos_gt(k.k->p, search_key)))
2355 k = btree_path_level_prev(trans, iter->path,
2356 &iter->path->l[0], &iter->k);
2357
2358 if (likely(k.k)) {
2359 if (iter->flags & BTREE_ITER_FILTER_SNAPSHOTS) {
2360 if (k.k->p.snapshot == iter->snapshot)
2361 goto got_key;
2362
2363 /*
2364 * If we have a saved candidate, and we're no
2365 * longer at the same _key_ (not pos), return
2366 * that candidate
2367 */
2368 if (saved_path && !bkey_eq(k.k->p, saved_k.p)) {
2369 bch2_path_put_nokeep(trans, iter->path,
2370 iter->flags & BTREE_ITER_INTENT);
2371 iter->path = saved_path;
2372 saved_path = NULL;
2373 iter->k = saved_k;
2374 k.v = saved_v;
2375 goto got_key;
2376 }
2377
2378 if (bch2_snapshot_is_ancestor(iter->trans->c,
2379 iter->snapshot,
2380 k.k->p.snapshot)) {
2381 if (saved_path)
2382 bch2_path_put_nokeep(trans, saved_path,
2383 iter->flags & BTREE_ITER_INTENT);
2384 saved_path = btree_path_clone(trans, iter->path,
2385 iter->flags & BTREE_ITER_INTENT);
2386 saved_k = *k.k;
2387 saved_v = k.v;
2388 }
2389
2390 search_key = bpos_predecessor(k.k->p);
2391 continue;
2392 }
2393 got_key:
2394 if (bkey_whiteout(k.k) &&
2395 !(iter->flags & BTREE_ITER_ALL_SNAPSHOTS)) {
2396 search_key = bkey_predecessor(iter, k.k->p);
2397 if (iter->flags & BTREE_ITER_FILTER_SNAPSHOTS)
2398 search_key.snapshot = U32_MAX;
2399 continue;
2400 }
2401
2402 break;
2403 } else if (likely(!bpos_eq(iter->path->l[0].b->data->min_key, POS_MIN))) {
2404 /* Advance to previous leaf node: */
2405 search_key = bpos_predecessor(iter->path->l[0].b->data->min_key);
2406 } else {
2407 /* Start of btree: */
2408 bch2_btree_iter_set_pos(iter, POS_MIN);
2409 k = bkey_s_c_null;
2410 goto out_no_locked;
2411 }
2412 }
2413
2414 EBUG_ON(bkey_gt(bkey_start_pos(k.k), iter->pos));
2415
2416 /* Extents can straddle iter->pos: */
2417 if (bkey_lt(k.k->p, iter->pos))
2418 iter->pos = k.k->p;
2419
2420 if (iter->flags & BTREE_ITER_FILTER_SNAPSHOTS)
2421 iter->pos.snapshot = iter->snapshot;
2422
2423 btree_path_set_should_be_locked(iter->path);
2424 out_no_locked:
2425 if (saved_path)
2426 bch2_path_put_nokeep(trans, saved_path, iter->flags & BTREE_ITER_INTENT);
2427
2428 bch2_btree_iter_verify_entry_exit(iter);
2429 bch2_btree_iter_verify(iter);
2430
2431 return k;
2432 }
2433
2434 /**
2435 * bch2_btree_iter_prev() - returns first key less than iterator's current
2436 * position
2437 * @iter: iterator to peek from
2438 *
2439 * Returns: key if found, or an error extractable with bkey_err().
2440 */
2441 struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *iter)
2442 {
2443 if (!bch2_btree_iter_rewind(iter))
2444 return bkey_s_c_null;
2445
2446 return bch2_btree_iter_peek_prev(iter);
2447 }
2448
2449 struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *iter)
2450 {
2451 struct btree_trans *trans = iter->trans;
2452 struct bpos search_key;
2453 struct bkey_s_c k;
2454 int ret;
2455
2456 bch2_btree_iter_verify(iter);
2457 bch2_btree_iter_verify_entry_exit(iter);
2458 EBUG_ON(iter->flags & BTREE_ITER_ALL_LEVELS);
2459 EBUG_ON(iter->path->level && (iter->flags & BTREE_ITER_WITH_KEY_CACHE));
2460
2461 /* extents can't span inode numbers: */
2462 if ((iter->flags & BTREE_ITER_IS_EXTENTS) &&
2463 unlikely(iter->pos.offset == KEY_OFFSET_MAX)) {
2464 if (iter->pos.inode == KEY_INODE_MAX)
2465 return bkey_s_c_null;
2466
2467 bch2_btree_iter_set_pos(iter, bpos_nosnap_successor(iter->pos));
2468 }
2469
2470 search_key = btree_iter_search_key(iter);
2471 iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key,
2472 iter->flags & BTREE_ITER_INTENT,
2473 btree_iter_ip_allocated(iter));
2474
2475 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
2476 if (unlikely(ret)) {
2477 k = bkey_s_c_err(ret);
2478 goto out_no_locked;
2479 }
2480
2481 if ((iter->flags & BTREE_ITER_CACHED) ||
2482 !(iter->flags & (BTREE_ITER_IS_EXTENTS|BTREE_ITER_FILTER_SNAPSHOTS))) {
2483 struct bkey_i *next_update;
2484
2485 if ((next_update = btree_trans_peek_updates(iter)) &&
2486 bpos_eq(next_update->k.p, iter->pos)) {
2487 iter->k = next_update->k;
2488 k = bkey_i_to_s_c(next_update);
2489 goto out;
2490 }
2491
2492 if (unlikely(iter->flags & BTREE_ITER_WITH_JOURNAL) &&
2493 (k = btree_trans_peek_slot_journal(trans, iter)).k)
2494 goto out;
2495
2496 if (unlikely(iter->flags & BTREE_ITER_WITH_KEY_CACHE) &&
2497 (k = btree_trans_peek_key_cache(iter, iter->pos)).k) {
2498 if (!bkey_err(k))
2499 iter->k = *k.k;
2500 /* We're not returning a key from iter->path: */
2501 goto out_no_locked;
2502 }
2503
2504 k = bch2_btree_path_peek_slot(iter->path, &iter->k);
2505 if (unlikely(!k.k))
2506 goto out_no_locked;
2507 } else {
2508 struct bpos next;
2509 struct bpos end = iter->pos;
2510
2511 if (iter->flags & BTREE_ITER_IS_EXTENTS)
2512 end.offset = U64_MAX;
2513
2514 EBUG_ON(iter->path->level);
2515
2516 if (iter->flags & BTREE_ITER_INTENT) {
2517 struct btree_iter iter2;
2518
2519 bch2_trans_copy_iter(&iter2, iter);
2520 k = bch2_btree_iter_peek_upto(&iter2, end);
2521
2522 if (k.k && !bkey_err(k)) {
2523 iter->k = iter2.k;
2524 k.k = &iter->k;
2525 }
2526 bch2_trans_iter_exit(trans, &iter2);
2527 } else {
2528 struct bpos pos = iter->pos;
2529
2530 k = bch2_btree_iter_peek_upto(iter, end);
2531 if (unlikely(bkey_err(k)))
2532 bch2_btree_iter_set_pos(iter, pos);
2533 else
2534 iter->pos = pos;
2535 }
2536
2537 if (unlikely(bkey_err(k)))
2538 goto out_no_locked;
2539
2540 next = k.k ? bkey_start_pos(k.k) : POS_MAX;
2541
2542 if (bkey_lt(iter->pos, next)) {
2543 bkey_init(&iter->k);
2544 iter->k.p = iter->pos;
2545
2546 if (iter->flags & BTREE_ITER_IS_EXTENTS) {
2547 bch2_key_resize(&iter->k,
2548 min_t(u64, KEY_SIZE_MAX,
2549 (next.inode == iter->pos.inode
2550 ? next.offset
2551 : KEY_OFFSET_MAX) -
2552 iter->pos.offset));
2553 EBUG_ON(!iter->k.size);
2554 }
2555
2556 k = (struct bkey_s_c) { &iter->k, NULL };
2557 }
2558 }
2559 out:
2560 btree_path_set_should_be_locked(iter->path);
2561 out_no_locked:
2562 bch2_btree_iter_verify_entry_exit(iter);
2563 bch2_btree_iter_verify(iter);
2564 ret = bch2_btree_iter_verify_ret(iter, k);
2565 if (unlikely(ret))
2566 return bkey_s_c_err(ret);
2567
2568 return k;
2569 }
2570
2571 struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *iter)
2572 {
2573 if (!bch2_btree_iter_advance(iter))
2574 return bkey_s_c_null;
2575
2576 return bch2_btree_iter_peek_slot(iter);
2577 }
2578
2579 struct bkey_s_c bch2_btree_iter_prev_slot(struct btree_iter *iter)
2580 {
2581 if (!bch2_btree_iter_rewind(iter))
2582 return bkey_s_c_null;
2583
2584 return bch2_btree_iter_peek_slot(iter);
2585 }
2586
2587 struct bkey_s_c bch2_btree_iter_peek_and_restart_outlined(struct btree_iter *iter)
2588 {
2589 struct bkey_s_c k;
2590
2591 while (btree_trans_too_many_iters(iter->trans) ||
2592 (k = bch2_btree_iter_peek_type(iter, iter->flags),
2593 bch2_err_matches(bkey_err(k), BCH_ERR_transaction_restart)))
2594 bch2_trans_begin(iter->trans);
2595
2596 return k;
2597 }
2598
2599 /* new transactional stuff: */
2600
2601 #ifdef CONFIG_BCACHEFS_DEBUG
2602 static void btree_trans_verify_sorted_refs(struct btree_trans *trans)
2603 {
2604 struct btree_path *path;
2605 unsigned i;
2606
2607 BUG_ON(trans->nr_sorted != hweight64(trans->paths_allocated));
2608
2609 trans_for_each_path(trans, path) {
2610 BUG_ON(path->sorted_idx >= trans->nr_sorted);
2611 BUG_ON(trans->sorted[path->sorted_idx] != path->idx);
2612 }
2613
2614 for (i = 0; i < trans->nr_sorted; i++) {
2615 unsigned idx = trans->sorted[i];
2616
2617 EBUG_ON(!(trans->paths_allocated & (1ULL << idx)));
2618 BUG_ON(trans->paths[idx].sorted_idx != i);
2619 }
2620 }
2621
2622 static void btree_trans_verify_sorted(struct btree_trans *trans)
2623 {
2624 struct btree_path *path, *prev = NULL;
2625 unsigned i;
2626
2627 if (!bch2_debug_check_iterators)
2628 return;
2629
2630 trans_for_each_path_inorder(trans, path, i) {
2631 if (prev && btree_path_cmp(prev, path) > 0) {
2632 __bch2_dump_trans_paths_updates(trans, true);
2633 panic("trans paths out of order!\n");
2634 }
2635 prev = path;
2636 }
2637 }
2638 #else
2639 static inline void btree_trans_verify_sorted_refs(struct btree_trans *trans) {}
2640 static inline void btree_trans_verify_sorted(struct btree_trans *trans) {}
2641 #endif
2642
2643 void __bch2_btree_trans_sort_paths(struct btree_trans *trans)
2644 {
2645 int i, l = 0, r = trans->nr_sorted, inc = 1;
2646 bool swapped;
2647
2648 btree_trans_verify_sorted_refs(trans);
2649
2650 if (trans->paths_sorted)
2651 goto out;
2652
2653 /*
2654 * Cocktail shaker sort: this is efficient because iterators will be
2655 * mostly sorted.
2656 */
2657 do {
2658 swapped = false;
2659
2660 for (i = inc > 0 ? l : r - 2;
2661 i + 1 < r && i >= l;
2662 i += inc) {
2663 if (btree_path_cmp(trans->paths + trans->sorted[i],
2664 trans->paths + trans->sorted[i + 1]) > 0) {
2665 swap(trans->sorted[i], trans->sorted[i + 1]);
2666 trans->paths[trans->sorted[i]].sorted_idx = i;
2667 trans->paths[trans->sorted[i + 1]].sorted_idx = i + 1;
2668 swapped = true;
2669 }
2670 }
2671
2672 if (inc > 0)
2673 --r;
2674 else
2675 l++;
2676 inc = -inc;
2677 } while (swapped);
2678
2679 trans->paths_sorted = true;
2680 out:
2681 btree_trans_verify_sorted(trans);
2682 }
2683
2684 static inline void btree_path_list_remove(struct btree_trans *trans,
2685 struct btree_path *path)
2686 {
2687 unsigned i;
2688
2689 EBUG_ON(path->sorted_idx >= trans->nr_sorted);
2690 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
2691 trans->nr_sorted--;
2692 memmove_u64s_down_small(trans->sorted + path->sorted_idx,
2693 trans->sorted + path->sorted_idx + 1,
2694 DIV_ROUND_UP(trans->nr_sorted - path->sorted_idx, 8));
2695 #else
2696 array_remove_item(trans->sorted, trans->nr_sorted, path->sorted_idx);
2697 #endif
2698 for (i = path->sorted_idx; i < trans->nr_sorted; i++)
2699 trans->paths[trans->sorted[i]].sorted_idx = i;
2700
2701 path->sorted_idx = U8_MAX;
2702 }
2703
2704 static inline void btree_path_list_add(struct btree_trans *trans,
2705 struct btree_path *pos,
2706 struct btree_path *path)
2707 {
2708 unsigned i;
2709
2710 path->sorted_idx = pos ? pos->sorted_idx + 1 : trans->nr_sorted;
2711
2712 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
2713 memmove_u64s_up_small(trans->sorted + path->sorted_idx + 1,
2714 trans->sorted + path->sorted_idx,
2715 DIV_ROUND_UP(trans->nr_sorted - path->sorted_idx, 8));
2716 trans->nr_sorted++;
2717 trans->sorted[path->sorted_idx] = path->idx;
2718 #else
2719 array_insert_item(trans->sorted, trans->nr_sorted, path->sorted_idx, path->idx);
2720 #endif
2721
2722 for (i = path->sorted_idx; i < trans->nr_sorted; i++)
2723 trans->paths[trans->sorted[i]].sorted_idx = i;
2724
2725 btree_trans_verify_sorted_refs(trans);
2726 }
2727
2728 void bch2_trans_iter_exit(struct btree_trans *trans, struct btree_iter *iter)
2729 {
2730 if (iter->update_path)
2731 bch2_path_put_nokeep(trans, iter->update_path,
2732 iter->flags & BTREE_ITER_INTENT);
2733 if (iter->path)
2734 bch2_path_put(trans, iter->path,
2735 iter->flags & BTREE_ITER_INTENT);
2736 if (iter->key_cache_path)
2737 bch2_path_put(trans, iter->key_cache_path,
2738 iter->flags & BTREE_ITER_INTENT);
2739 iter->path = NULL;
2740 iter->update_path = NULL;
2741 iter->key_cache_path = NULL;
2742 }
2743
2744 void bch2_trans_iter_init_outlined(struct btree_trans *trans,
2745 struct btree_iter *iter,
2746 enum btree_id btree_id, struct bpos pos,
2747 unsigned flags)
2748 {
2749 bch2_trans_iter_init_common(trans, iter, btree_id, pos, 0, 0,
2750 bch2_btree_iter_flags(trans, btree_id, flags),
2751 _RET_IP_);
2752 }
2753
2754 void bch2_trans_node_iter_init(struct btree_trans *trans,
2755 struct btree_iter *iter,
2756 enum btree_id btree_id,
2757 struct bpos pos,
2758 unsigned locks_want,
2759 unsigned depth,
2760 unsigned flags)
2761 {
2762 flags |= BTREE_ITER_NOT_EXTENTS;
2763 flags |= __BTREE_ITER_ALL_SNAPSHOTS;
2764 flags |= BTREE_ITER_ALL_SNAPSHOTS;
2765
2766 bch2_trans_iter_init_common(trans, iter, btree_id, pos, locks_want, depth,
2767 __bch2_btree_iter_flags(trans, btree_id, flags),
2768 _RET_IP_);
2769
2770 iter->min_depth = depth;
2771
2772 BUG_ON(iter->path->locks_want < min(locks_want, BTREE_MAX_DEPTH));
2773 BUG_ON(iter->path->level != depth);
2774 BUG_ON(iter->min_depth != depth);
2775 }
2776
2777 void bch2_trans_copy_iter(struct btree_iter *dst, struct btree_iter *src)
2778 {
2779 *dst = *src;
2780 if (src->path)
2781 __btree_path_get(src->path, src->flags & BTREE_ITER_INTENT);
2782 if (src->update_path)
2783 __btree_path_get(src->update_path, src->flags & BTREE_ITER_INTENT);
2784 dst->key_cache_path = NULL;
2785 }
2786
2787 void *__bch2_trans_kmalloc(struct btree_trans *trans, size_t size)
2788 {
2789 unsigned new_top = trans->mem_top + size;
2790 size_t old_bytes = trans->mem_bytes;
2791 size_t new_bytes = roundup_pow_of_two(new_top);
2792 int ret;
2793 void *new_mem;
2794 void *p;
2795
2796 trans->mem_max = max(trans->mem_max, new_top);
2797
2798 WARN_ON_ONCE(new_bytes > BTREE_TRANS_MEM_MAX);
2799
2800 new_mem = krealloc(trans->mem, new_bytes, GFP_NOWAIT|__GFP_NOWARN);
2801 if (unlikely(!new_mem)) {
2802 bch2_trans_unlock(trans);
2803
2804 new_mem = krealloc(trans->mem, new_bytes, GFP_KERNEL);
2805 if (!new_mem && new_bytes <= BTREE_TRANS_MEM_MAX) {
2806 new_mem = mempool_alloc(&trans->c->btree_trans_mem_pool, GFP_KERNEL);
2807 new_bytes = BTREE_TRANS_MEM_MAX;
2808 kfree(trans->mem);
2809 }
2810
2811 if (!new_mem)
2812 return ERR_PTR(-BCH_ERR_ENOMEM_trans_kmalloc);
2813
2814 trans->mem = new_mem;
2815 trans->mem_bytes = new_bytes;
2816
2817 ret = bch2_trans_relock(trans);
2818 if (ret)
2819 return ERR_PTR(ret);
2820 }
2821
2822 trans->mem = new_mem;
2823 trans->mem_bytes = new_bytes;
2824
2825 if (old_bytes) {
2826 trace_and_count(trans->c, trans_restart_mem_realloced, trans, _RET_IP_, new_bytes);
2827 return ERR_PTR(btree_trans_restart(trans, BCH_ERR_transaction_restart_mem_realloced));
2828 }
2829
2830 p = trans->mem + trans->mem_top;
2831 trans->mem_top += size;
2832 memset(p, 0, size);
2833 return p;
2834 }
2835
2836 static inline void check_srcu_held_too_long(struct btree_trans *trans)
2837 {
2838 WARN(trans->srcu_held && time_after(jiffies, trans->srcu_lock_time + HZ * 10),
2839 "btree trans held srcu lock (delaying memory reclaim) for %lu seconds",
2840 (jiffies - trans->srcu_lock_time) / HZ);
2841 }
2842
2843 void bch2_trans_srcu_unlock(struct btree_trans *trans)
2844 {
2845 if (trans->srcu_held) {
2846 struct bch_fs *c = trans->c;
2847 struct btree_path *path;
2848
2849 trans_for_each_path(trans, path)
2850 if (path->cached && !btree_node_locked(path, 0))
2851 path->l[0].b = ERR_PTR(-BCH_ERR_no_btree_node_srcu_reset);
2852
2853 check_srcu_held_too_long(trans);
2854 srcu_read_unlock(&c->btree_trans_barrier, trans->srcu_idx);
2855 trans->srcu_held = false;
2856 }
2857 }
2858
2859 void bch2_trans_srcu_lock(struct btree_trans *trans)
2860 {
2861 if (!trans->srcu_held) {
2862 trans->srcu_idx = srcu_read_lock(&trans->c->btree_trans_barrier);
2863 trans->srcu_lock_time = jiffies;
2864 trans->srcu_held = true;
2865 }
2866 }
2867
2868 /**
2869 * bch2_trans_begin() - reset a transaction after a interrupted attempt
2870 * @trans: transaction to reset
2871 *
2872 * Returns: current restart counter, to be used with trans_was_restarted()
2873 *
2874 * While iterating over nodes or updating nodes a attempt to lock a btree node
2875 * may return BCH_ERR_transaction_restart when the trylock fails. When this
2876 * occurs bch2_trans_begin() should be called and the transaction retried.
2877 */
2878 u32 bch2_trans_begin(struct btree_trans *trans)
2879 {
2880 struct btree_path *path;
2881 u64 now;
2882
2883 bch2_trans_reset_updates(trans);
2884
2885 trans->restart_count++;
2886 trans->mem_top = 0;
2887
2888 trans_for_each_path(trans, path) {
2889 path->should_be_locked = false;
2890
2891 /*
2892 * If the transaction wasn't restarted, we're presuming to be
2893 * doing something new: dont keep iterators excpt the ones that
2894 * are in use - except for the subvolumes btree:
2895 */
2896 if (!trans->restarted && path->btree_id != BTREE_ID_subvolumes)
2897 path->preserve = false;
2898
2899 /*
2900 * XXX: we probably shouldn't be doing this if the transaction
2901 * was restarted, but currently we still overflow transaction
2902 * iterators if we do that
2903 */
2904 if (!path->ref && !path->preserve)
2905 __bch2_path_free(trans, path);
2906 else
2907 path->preserve = false;
2908 }
2909
2910 now = local_clock();
2911 if (!trans->restarted &&
2912 (need_resched() ||
2913 now - trans->last_begin_time > BTREE_TRANS_MAX_LOCK_HOLD_TIME_NS)) {
2914 drop_locks_do(trans, (cond_resched(), 0));
2915 now = local_clock();
2916 }
2917 trans->last_begin_time = now;
2918
2919 if (unlikely(trans->srcu_held &&
2920 time_after(jiffies, trans->srcu_lock_time + msecs_to_jiffies(10))))
2921 bch2_trans_srcu_unlock(trans);
2922
2923 trans->last_begin_ip = _RET_IP_;
2924 if (trans->restarted) {
2925 bch2_btree_path_traverse_all(trans);
2926 trans->notrace_relock_fail = false;
2927 }
2928
2929 return trans->restart_count;
2930 }
2931
2932 static struct btree_trans *bch2_trans_alloc(struct bch_fs *c)
2933 {
2934 struct btree_trans *trans;
2935
2936 if (IS_ENABLED(__KERNEL__)) {
2937 trans = this_cpu_xchg(c->btree_trans_bufs->trans, NULL);
2938 if (trans)
2939 return trans;
2940 }
2941
2942 trans = mempool_alloc(&c->btree_trans_pool, GFP_NOFS);
2943 /*
2944 * paths need to be zeroed, bch2_check_for_deadlock looks at
2945 * paths in other threads
2946 */
2947 memset(&trans->paths, 0, sizeof(trans->paths));
2948 return trans;
2949 }
2950
2951 const char *bch2_btree_transaction_fns[BCH_TRANSACTIONS_NR];
2952
2953 unsigned bch2_trans_get_fn_idx(const char *fn)
2954 {
2955 unsigned i;
2956
2957 for (i = 0; i < ARRAY_SIZE(bch2_btree_transaction_fns); i++)
2958 if (!bch2_btree_transaction_fns[i] ||
2959 bch2_btree_transaction_fns[i] == fn) {
2960 bch2_btree_transaction_fns[i] = fn;
2961 return i;
2962 }
2963
2964 pr_warn_once("BCH_TRANSACTIONS_NR not big enough!");
2965 return i;
2966 }
2967
2968 struct btree_trans *__bch2_trans_get(struct bch_fs *c, unsigned fn_idx)
2969 __acquires(&c->btree_trans_barrier)
2970 {
2971 struct btree_trans *trans;
2972 struct btree_transaction_stats *s;
2973
2974 trans = bch2_trans_alloc(c);
2975
2976 memset(trans, 0, sizeof(*trans));
2977 trans->c = c;
2978 trans->fn = fn_idx < ARRAY_SIZE(bch2_btree_transaction_fns)
2979 ? bch2_btree_transaction_fns[fn_idx] : NULL;
2980 trans->last_begin_time = local_clock();
2981 trans->fn_idx = fn_idx;
2982 trans->locking_wait.task = current;
2983 trans->journal_replay_not_finished =
2984 unlikely(!test_bit(JOURNAL_REPLAY_DONE, &c->journal.flags)) &&
2985 atomic_inc_not_zero(&c->journal_keys.ref);
2986 closure_init_stack(&trans->ref);
2987
2988 s = btree_trans_stats(trans);
2989 if (s && s->max_mem) {
2990 unsigned expected_mem_bytes = roundup_pow_of_two(s->max_mem);
2991
2992 trans->mem = kmalloc(expected_mem_bytes, GFP_KERNEL);
2993
2994 if (!unlikely(trans->mem)) {
2995 trans->mem = mempool_alloc(&c->btree_trans_mem_pool, GFP_KERNEL);
2996 trans->mem_bytes = BTREE_TRANS_MEM_MAX;
2997 } else {
2998 trans->mem_bytes = expected_mem_bytes;
2999 }
3000 }
3001
3002 if (s) {
3003 trans->nr_max_paths = s->nr_max_paths;
3004 trans->wb_updates_size = s->wb_updates_size;
3005 }
3006
3007 trans->srcu_idx = srcu_read_lock(&c->btree_trans_barrier);
3008 trans->srcu_lock_time = jiffies;
3009 trans->srcu_held = true;
3010
3011 if (IS_ENABLED(CONFIG_BCACHEFS_DEBUG_TRANSACTIONS)) {
3012 struct btree_trans *pos;
3013
3014 seqmutex_lock(&c->btree_trans_lock);
3015 list_for_each_entry(pos, &c->btree_trans_list, list) {
3016 /*
3017 * We'd much prefer to be stricter here and completely
3018 * disallow multiple btree_trans in the same thread -
3019 * but the data move path calls bch2_write when we
3020 * already have a btree_trans initialized.
3021 */
3022 BUG_ON(trans->locking_wait.task->pid == pos->locking_wait.task->pid &&
3023 bch2_trans_locked(pos));
3024
3025 if (trans->locking_wait.task->pid < pos->locking_wait.task->pid) {
3026 list_add_tail(&trans->list, &pos->list);
3027 goto list_add_done;
3028 }
3029 }
3030 list_add_tail(&trans->list, &c->btree_trans_list);
3031 list_add_done:
3032 seqmutex_unlock(&c->btree_trans_lock);
3033 }
3034
3035 return trans;
3036 }
3037
3038 static void check_btree_paths_leaked(struct btree_trans *trans)
3039 {
3040 #ifdef CONFIG_BCACHEFS_DEBUG
3041 struct bch_fs *c = trans->c;
3042 struct btree_path *path;
3043
3044 trans_for_each_path(trans, path)
3045 if (path->ref)
3046 goto leaked;
3047 return;
3048 leaked:
3049 bch_err(c, "btree paths leaked from %s!", trans->fn);
3050 trans_for_each_path(trans, path)
3051 if (path->ref)
3052 printk(KERN_ERR " btree %s %pS\n",
3053 bch2_btree_id_str(path->btree_id),
3054 (void *) path->ip_allocated);
3055 /* Be noisy about this: */
3056 bch2_fatal_error(c);
3057 #endif
3058 }
3059
3060 void bch2_trans_put(struct btree_trans *trans)
3061 __releases(&c->btree_trans_barrier)
3062 {
3063 struct btree_insert_entry *i;
3064 struct bch_fs *c = trans->c;
3065 struct btree_transaction_stats *s = btree_trans_stats(trans);
3066
3067 bch2_trans_unlock(trans);
3068
3069 if (IS_ENABLED(CONFIG_BCACHEFS_DEBUG_TRANSACTIONS)) {
3070 seqmutex_lock(&c->btree_trans_lock);
3071 list_del(&trans->list);
3072 seqmutex_unlock(&c->btree_trans_lock);
3073 }
3074
3075 closure_sync(&trans->ref);
3076
3077 if (s)
3078 s->max_mem = max(s->max_mem, trans->mem_max);
3079
3080 trans_for_each_update(trans, i)
3081 __btree_path_put(i->path, true);
3082 trans->nr_updates = 0;
3083
3084 check_btree_paths_leaked(trans);
3085
3086 if (trans->srcu_held) {
3087 check_srcu_held_too_long(trans);
3088 srcu_read_unlock(&c->btree_trans_barrier, trans->srcu_idx);
3089 }
3090
3091 kfree(trans->extra_journal_entries.data);
3092
3093 if (trans->fs_usage_deltas) {
3094 if (trans->fs_usage_deltas->size + sizeof(trans->fs_usage_deltas) ==
3095 REPLICAS_DELTA_LIST_MAX)
3096 mempool_free(trans->fs_usage_deltas,
3097 &c->replicas_delta_pool);
3098 else
3099 kfree(trans->fs_usage_deltas);
3100 }
3101
3102 if (unlikely(trans->journal_replay_not_finished))
3103 bch2_journal_keys_put(c);
3104
3105 if (trans->mem_bytes == BTREE_TRANS_MEM_MAX)
3106 mempool_free(trans->mem, &c->btree_trans_mem_pool);
3107 else
3108 kfree(trans->mem);
3109
3110 /* Userspace doesn't have a real percpu implementation: */
3111 if (IS_ENABLED(__KERNEL__))
3112 trans = this_cpu_xchg(c->btree_trans_bufs->trans, trans);
3113 if (trans)
3114 mempool_free(trans, &c->btree_trans_pool);
3115 }
3116
3117 static void __maybe_unused
3118 bch2_btree_bkey_cached_common_to_text(struct printbuf *out,
3119 struct btree_bkey_cached_common *b)
3120 {
3121 struct six_lock_count c = six_lock_counts(&b->lock);
3122 struct task_struct *owner;
3123 pid_t pid;
3124
3125 rcu_read_lock();
3126 owner = READ_ONCE(b->lock.owner);
3127 pid = owner ? owner->pid : 0;
3128 rcu_read_unlock();
3129
3130 prt_tab(out);
3131 prt_printf(out, "%px %c l=%u %s:", b, b->cached ? 'c' : 'b',
3132 b->level, bch2_btree_id_str(b->btree_id));
3133 bch2_bpos_to_text(out, btree_node_pos(b));
3134
3135 prt_tab(out);
3136 prt_printf(out, " locks %u:%u:%u held by pid %u",
3137 c.n[0], c.n[1], c.n[2], pid);
3138 }
3139
3140 void bch2_btree_trans_to_text(struct printbuf *out, struct btree_trans *trans)
3141 {
3142 struct btree_path *path;
3143 struct btree_bkey_cached_common *b;
3144 static char lock_types[] = { 'r', 'i', 'w' };
3145 unsigned l, idx;
3146
3147 if (!out->nr_tabstops) {
3148 printbuf_tabstop_push(out, 16);
3149 printbuf_tabstop_push(out, 32);
3150 }
3151
3152 prt_printf(out, "%i %s\n", trans->locking_wait.task->pid, trans->fn);
3153
3154 trans_for_each_path_safe(trans, path, idx) {
3155 if (!path->nodes_locked)
3156 continue;
3157
3158 prt_printf(out, " path %u %c l=%u %s:",
3159 path->idx,
3160 path->cached ? 'c' : 'b',
3161 path->level,
3162 bch2_btree_id_str(path->btree_id));
3163 bch2_bpos_to_text(out, path->pos);
3164 prt_newline(out);
3165
3166 for (l = 0; l < BTREE_MAX_DEPTH; l++) {
3167 if (btree_node_locked(path, l) &&
3168 !IS_ERR_OR_NULL(b = (void *) READ_ONCE(path->l[l].b))) {
3169 prt_printf(out, " %c l=%u ",
3170 lock_types[btree_node_locked_type(path, l)], l);
3171 bch2_btree_bkey_cached_common_to_text(out, b);
3172 prt_newline(out);
3173 }
3174 }
3175 }
3176
3177 b = READ_ONCE(trans->locking);
3178 if (b) {
3179 prt_printf(out, " blocked for %lluus on",
3180 div_u64(local_clock() - trans->locking_wait.start_time,
3181 1000));
3182 prt_newline(out);
3183 prt_printf(out, " %c", lock_types[trans->locking_wait.lock_want]);
3184 bch2_btree_bkey_cached_common_to_text(out, b);
3185 prt_newline(out);
3186 }
3187 }
3188
3189 void bch2_fs_btree_iter_exit(struct bch_fs *c)
3190 {
3191 struct btree_transaction_stats *s;
3192 struct btree_trans *trans;
3193 int cpu;
3194
3195 trans = list_first_entry_or_null(&c->btree_trans_list, struct btree_trans, list);
3196 if (trans)
3197 panic("%s leaked btree_trans\n", trans->fn);
3198
3199 if (c->btree_trans_bufs)
3200 for_each_possible_cpu(cpu)
3201 kfree(per_cpu_ptr(c->btree_trans_bufs, cpu)->trans);
3202 free_percpu(c->btree_trans_bufs);
3203
3204 for (s = c->btree_transaction_stats;
3205 s < c->btree_transaction_stats + ARRAY_SIZE(c->btree_transaction_stats);
3206 s++) {
3207 kfree(s->max_paths_text);
3208 bch2_time_stats_exit(&s->lock_hold_times);
3209 }
3210
3211 if (c->btree_trans_barrier_initialized)
3212 cleanup_srcu_struct(&c->btree_trans_barrier);
3213 mempool_exit(&c->btree_trans_mem_pool);
3214 mempool_exit(&c->btree_trans_pool);
3215 }
3216
3217 int bch2_fs_btree_iter_init(struct bch_fs *c)
3218 {
3219 struct btree_transaction_stats *s;
3220 int ret;
3221
3222 for (s = c->btree_transaction_stats;
3223 s < c->btree_transaction_stats + ARRAY_SIZE(c->btree_transaction_stats);
3224 s++) {
3225 bch2_time_stats_init(&s->lock_hold_times);
3226 mutex_init(&s->lock);
3227 }
3228
3229 INIT_LIST_HEAD(&c->btree_trans_list);
3230 seqmutex_init(&c->btree_trans_lock);
3231
3232 c->btree_trans_bufs = alloc_percpu(struct btree_trans_buf);
3233 if (!c->btree_trans_bufs)
3234 return -ENOMEM;
3235
3236 ret = mempool_init_kmalloc_pool(&c->btree_trans_pool, 1,
3237 sizeof(struct btree_trans)) ?:
3238 mempool_init_kmalloc_pool(&c->btree_trans_mem_pool, 1,
3239 BTREE_TRANS_MEM_MAX) ?:
3240 init_srcu_struct(&c->btree_trans_barrier);
3241 if (!ret)
3242 c->btree_trans_barrier_initialized = true;
3243 return ret;
3244 }
Mirror https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git