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 "journal_io.h"
17 #include "replicas.h"
18 #include "snapshot.h"
19 #include "trace.h"
20
21 #include <linux/random.h>
22 #include <linux/prefetch.h>
23
24 static inline void btree_path_list_remove(struct btree_trans *, struct btree_path *);
25 static inline void btree_path_list_add(struct btree_trans *,
26 btree_path_idx_t, btree_path_idx_t);
27
btree_iter_ip_allocated(struct btree_iter * iter)28 static inline unsigned long btree_iter_ip_allocated(struct btree_iter *iter)
29 {
30 #ifdef TRACK_PATH_ALLOCATED
31 return iter->ip_allocated;
32 #else
33 return 0;
34 #endif
35 }
36
37 static btree_path_idx_t btree_path_alloc(struct btree_trans *, btree_path_idx_t);
38 static void bch2_trans_srcu_lock(struct btree_trans *);
39
__btree_path_cmp(const struct btree_path * l,enum btree_id r_btree_id,bool r_cached,struct bpos r_pos,unsigned r_level)40 static inline int __btree_path_cmp(const struct btree_path *l,
41 enum btree_id r_btree_id,
42 bool r_cached,
43 struct bpos r_pos,
44 unsigned r_level)
45 {
46 /*
47 * Must match lock ordering as defined by __bch2_btree_node_lock:
48 */
49 return cmp_int(l->btree_id, r_btree_id) ?:
50 cmp_int((int) l->cached, (int) r_cached) ?:
51 bpos_cmp(l->pos, r_pos) ?:
52 -cmp_int(l->level, r_level);
53 }
54
btree_path_cmp(const struct btree_path * l,const struct btree_path * r)55 static inline int btree_path_cmp(const struct btree_path *l,
56 const struct btree_path *r)
57 {
58 return __btree_path_cmp(l, r->btree_id, r->cached, r->pos, r->level);
59 }
60
bkey_successor(struct btree_iter * iter,struct bpos p)61 static inline struct bpos bkey_successor(struct btree_iter *iter, struct bpos p)
62 {
63 /* Are we iterating over keys in all snapshots? */
64 if (iter->flags & BTREE_ITER_all_snapshots) {
65 p = bpos_successor(p);
66 } else {
67 p = bpos_nosnap_successor(p);
68 p.snapshot = iter->snapshot;
69 }
70
71 return p;
72 }
73
bkey_predecessor(struct btree_iter * iter,struct bpos p)74 static inline struct bpos bkey_predecessor(struct btree_iter *iter, struct bpos p)
75 {
76 /* Are we iterating over keys in all snapshots? */
77 if (iter->flags & BTREE_ITER_all_snapshots) {
78 p = bpos_predecessor(p);
79 } else {
80 p = bpos_nosnap_predecessor(p);
81 p.snapshot = iter->snapshot;
82 }
83
84 return p;
85 }
86
btree_iter_search_key(struct btree_iter * iter)87 static inline struct bpos btree_iter_search_key(struct btree_iter *iter)
88 {
89 struct bpos pos = iter->pos;
90
91 if ((iter->flags & BTREE_ITER_is_extents) &&
92 !bkey_eq(pos, POS_MAX))
93 pos = bkey_successor(iter, pos);
94 return pos;
95 }
96
btree_path_pos_before_node(struct btree_path * path,struct btree * b)97 static inline bool btree_path_pos_before_node(struct btree_path *path,
98 struct btree *b)
99 {
100 return bpos_lt(path->pos, b->data->min_key);
101 }
102
btree_path_pos_after_node(struct btree_path * path,struct btree * b)103 static inline bool btree_path_pos_after_node(struct btree_path *path,
104 struct btree *b)
105 {
106 return bpos_gt(path->pos, b->key.k.p);
107 }
108
btree_path_pos_in_node(struct btree_path * path,struct btree * b)109 static inline bool btree_path_pos_in_node(struct btree_path *path,
110 struct btree *b)
111 {
112 return path->btree_id == b->c.btree_id &&
113 !btree_path_pos_before_node(path, b) &&
114 !btree_path_pos_after_node(path, b);
115 }
116
117 /* Btree iterator: */
118
119 #ifdef CONFIG_BCACHEFS_DEBUG
120
bch2_btree_path_verify_cached(struct btree_trans * trans,struct btree_path * path)121 static void bch2_btree_path_verify_cached(struct btree_trans *trans,
122 struct btree_path *path)
123 {
124 struct bkey_cached *ck;
125 bool locked = btree_node_locked(path, 0);
126
127 if (!bch2_btree_node_relock(trans, path, 0))
128 return;
129
130 ck = (void *) path->l[0].b;
131 BUG_ON(ck->key.btree_id != path->btree_id ||
132 !bkey_eq(ck->key.pos, path->pos));
133
134 if (!locked)
135 btree_node_unlock(trans, path, 0);
136 }
137
bch2_btree_path_verify_level(struct btree_trans * trans,struct btree_path * path,unsigned level)138 static void bch2_btree_path_verify_level(struct btree_trans *trans,
139 struct btree_path *path, unsigned level)
140 {
141 struct btree_path_level *l;
142 struct btree_node_iter tmp;
143 bool locked;
144 struct bkey_packed *p, *k;
145 struct printbuf buf1 = PRINTBUF;
146 struct printbuf buf2 = PRINTBUF;
147 struct printbuf buf3 = PRINTBUF;
148 const char *msg;
149
150 if (!bch2_debug_check_iterators)
151 return;
152
153 l = &path->l[level];
154 tmp = l->iter;
155 locked = btree_node_locked(path, level);
156
157 if (path->cached) {
158 if (!level)
159 bch2_btree_path_verify_cached(trans, path);
160 return;
161 }
162
163 if (!btree_path_node(path, level))
164 return;
165
166 if (!bch2_btree_node_relock_notrace(trans, path, level))
167 return;
168
169 BUG_ON(!btree_path_pos_in_node(path, l->b));
170
171 bch2_btree_node_iter_verify(&l->iter, l->b);
172
173 /*
174 * For interior nodes, the iterator will have skipped past deleted keys:
175 */
176 p = level
177 ? bch2_btree_node_iter_prev(&tmp, l->b)
178 : bch2_btree_node_iter_prev_all(&tmp, l->b);
179 k = bch2_btree_node_iter_peek_all(&l->iter, l->b);
180
181 if (p && bkey_iter_pos_cmp(l->b, p, &path->pos) >= 0) {
182 msg = "before";
183 goto err;
184 }
185
186 if (k && bkey_iter_pos_cmp(l->b, k, &path->pos) < 0) {
187 msg = "after";
188 goto err;
189 }
190
191 if (!locked)
192 btree_node_unlock(trans, path, level);
193 return;
194 err:
195 bch2_bpos_to_text(&buf1, path->pos);
196
197 if (p) {
198 struct bkey uk = bkey_unpack_key(l->b, p);
199
200 bch2_bkey_to_text(&buf2, &uk);
201 } else {
202 prt_printf(&buf2, "(none)");
203 }
204
205 if (k) {
206 struct bkey uk = bkey_unpack_key(l->b, k);
207
208 bch2_bkey_to_text(&buf3, &uk);
209 } else {
210 prt_printf(&buf3, "(none)");
211 }
212
213 panic("path should be %s key at level %u:\n"
214 "path pos %s\n"
215 "prev key %s\n"
216 "cur key %s\n",
217 msg, level, buf1.buf, buf2.buf, buf3.buf);
218 }
219
bch2_btree_path_verify(struct btree_trans * trans,struct btree_path * path)220 static void bch2_btree_path_verify(struct btree_trans *trans,
221 struct btree_path *path)
222 {
223 struct bch_fs *c = trans->c;
224
225 for (unsigned i = 0; i < (!path->cached ? BTREE_MAX_DEPTH : 1); i++) {
226 if (!path->l[i].b) {
227 BUG_ON(!path->cached &&
228 bch2_btree_id_root(c, path->btree_id)->b->c.level > i);
229 break;
230 }
231
232 bch2_btree_path_verify_level(trans, path, i);
233 }
234
235 bch2_btree_path_verify_locks(path);
236 }
237
bch2_trans_verify_paths(struct btree_trans * trans)238 void bch2_trans_verify_paths(struct btree_trans *trans)
239 {
240 struct btree_path *path;
241 unsigned iter;
242
243 trans_for_each_path(trans, path, iter)
244 bch2_btree_path_verify(trans, path);
245 }
246
bch2_btree_iter_verify(struct btree_iter * iter)247 static void bch2_btree_iter_verify(struct btree_iter *iter)
248 {
249 struct btree_trans *trans = iter->trans;
250
251 BUG_ON(!!(iter->flags & BTREE_ITER_cached) != btree_iter_path(trans, iter)->cached);
252
253 BUG_ON((iter->flags & BTREE_ITER_is_extents) &&
254 (iter->flags & BTREE_ITER_all_snapshots));
255
256 BUG_ON(!(iter->flags & BTREE_ITER_snapshot_field) &&
257 (iter->flags & BTREE_ITER_all_snapshots) &&
258 !btree_type_has_snapshot_field(iter->btree_id));
259
260 if (iter->update_path)
261 bch2_btree_path_verify(trans, &trans->paths[iter->update_path]);
262 bch2_btree_path_verify(trans, btree_iter_path(trans, iter));
263 }
264
bch2_btree_iter_verify_entry_exit(struct btree_iter * iter)265 static void bch2_btree_iter_verify_entry_exit(struct btree_iter *iter)
266 {
267 BUG_ON((iter->flags & BTREE_ITER_filter_snapshots) &&
268 !iter->pos.snapshot);
269
270 BUG_ON(!(iter->flags & BTREE_ITER_all_snapshots) &&
271 iter->pos.snapshot != iter->snapshot);
272
273 BUG_ON(bkey_lt(iter->pos, bkey_start_pos(&iter->k)) ||
274 bkey_gt(iter->pos, iter->k.p));
275 }
276
bch2_btree_iter_verify_ret(struct btree_iter * iter,struct bkey_s_c k)277 static int bch2_btree_iter_verify_ret(struct btree_iter *iter, struct bkey_s_c k)
278 {
279 struct btree_trans *trans = iter->trans;
280 struct btree_iter copy;
281 struct bkey_s_c prev;
282 int ret = 0;
283
284 if (!bch2_debug_check_iterators)
285 return 0;
286
287 if (!(iter->flags & BTREE_ITER_filter_snapshots))
288 return 0;
289
290 if (bkey_err(k) || !k.k)
291 return 0;
292
293 BUG_ON(!bch2_snapshot_is_ancestor(trans->c,
294 iter->snapshot,
295 k.k->p.snapshot));
296
297 bch2_trans_iter_init(trans, ©, iter->btree_id, iter->pos,
298 BTREE_ITER_nopreserve|
299 BTREE_ITER_all_snapshots);
300 prev = bch2_btree_iter_prev(©);
301 if (!prev.k)
302 goto out;
303
304 ret = bkey_err(prev);
305 if (ret)
306 goto out;
307
308 if (bkey_eq(prev.k->p, k.k->p) &&
309 bch2_snapshot_is_ancestor(trans->c, iter->snapshot,
310 prev.k->p.snapshot) > 0) {
311 struct printbuf buf1 = PRINTBUF, buf2 = PRINTBUF;
312
313 bch2_bkey_to_text(&buf1, k.k);
314 bch2_bkey_to_text(&buf2, prev.k);
315
316 panic("iter snap %u\n"
317 "k %s\n"
318 "prev %s\n",
319 iter->snapshot,
320 buf1.buf, buf2.buf);
321 }
322 out:
323 bch2_trans_iter_exit(trans, ©);
324 return ret;
325 }
326
bch2_assert_pos_locked(struct btree_trans * trans,enum btree_id id,struct bpos pos)327 void bch2_assert_pos_locked(struct btree_trans *trans, enum btree_id id,
328 struct bpos pos)
329 {
330 bch2_trans_verify_not_unlocked(trans);
331
332 struct btree_path *path;
333 struct trans_for_each_path_inorder_iter iter;
334 struct printbuf buf = PRINTBUF;
335
336 btree_trans_sort_paths(trans);
337
338 trans_for_each_path_inorder(trans, path, iter) {
339 if (path->btree_id != id ||
340 !btree_node_locked(path, 0) ||
341 !path->should_be_locked)
342 continue;
343
344 if (!path->cached) {
345 if (bkey_ge(pos, path->l[0].b->data->min_key) &&
346 bkey_le(pos, path->l[0].b->key.k.p))
347 return;
348 } else {
349 if (bkey_eq(pos, path->pos))
350 return;
351 }
352 }
353
354 bch2_dump_trans_paths_updates(trans);
355 bch2_bpos_to_text(&buf, pos);
356
357 panic("not locked: %s %s\n", bch2_btree_id_str(id), buf.buf);
358 }
359
360 #else
361
bch2_btree_path_verify_level(struct btree_trans * trans,struct btree_path * path,unsigned l)362 static inline void bch2_btree_path_verify_level(struct btree_trans *trans,
363 struct btree_path *path, unsigned l) {}
bch2_btree_path_verify(struct btree_trans * trans,struct btree_path * path)364 static inline void bch2_btree_path_verify(struct btree_trans *trans,
365 struct btree_path *path) {}
bch2_btree_iter_verify(struct btree_iter * iter)366 static inline void bch2_btree_iter_verify(struct btree_iter *iter) {}
bch2_btree_iter_verify_entry_exit(struct btree_iter * iter)367 static inline void bch2_btree_iter_verify_entry_exit(struct btree_iter *iter) {}
bch2_btree_iter_verify_ret(struct btree_iter * iter,struct bkey_s_c k)368 static inline int bch2_btree_iter_verify_ret(struct btree_iter *iter, struct bkey_s_c k) { return 0; }
369
370 #endif
371
372 /* Btree path: fixups after btree updates */
373
btree_node_iter_set_set_pos(struct btree_node_iter * iter,struct btree * b,struct bset_tree * t,struct bkey_packed * k)374 static void btree_node_iter_set_set_pos(struct btree_node_iter *iter,
375 struct btree *b,
376 struct bset_tree *t,
377 struct bkey_packed *k)
378 {
379 struct btree_node_iter_set *set;
380
381 btree_node_iter_for_each(iter, set)
382 if (set->end == t->end_offset) {
383 set->k = __btree_node_key_to_offset(b, k);
384 bch2_btree_node_iter_sort(iter, b);
385 return;
386 }
387
388 bch2_btree_node_iter_push(iter, b, k, btree_bkey_last(b, t));
389 }
390
__bch2_btree_path_fix_key_modified(struct btree_path * path,struct btree * b,struct bkey_packed * where)391 static void __bch2_btree_path_fix_key_modified(struct btree_path *path,
392 struct btree *b,
393 struct bkey_packed *where)
394 {
395 struct btree_path_level *l = &path->l[b->c.level];
396
397 if (where != bch2_btree_node_iter_peek_all(&l->iter, l->b))
398 return;
399
400 if (bkey_iter_pos_cmp(l->b, where, &path->pos) < 0)
401 bch2_btree_node_iter_advance(&l->iter, l->b);
402 }
403
bch2_btree_path_fix_key_modified(struct btree_trans * trans,struct btree * b,struct bkey_packed * where)404 void bch2_btree_path_fix_key_modified(struct btree_trans *trans,
405 struct btree *b,
406 struct bkey_packed *where)
407 {
408 struct btree_path *path;
409 unsigned i;
410
411 trans_for_each_path_with_node(trans, b, path, i) {
412 __bch2_btree_path_fix_key_modified(path, b, where);
413 bch2_btree_path_verify_level(trans, path, b->c.level);
414 }
415 }
416
__bch2_btree_node_iter_fix(struct btree_path * path,struct btree * b,struct btree_node_iter * node_iter,struct bset_tree * t,struct bkey_packed * where,unsigned clobber_u64s,unsigned new_u64s)417 static void __bch2_btree_node_iter_fix(struct btree_path *path,
418 struct btree *b,
419 struct btree_node_iter *node_iter,
420 struct bset_tree *t,
421 struct bkey_packed *where,
422 unsigned clobber_u64s,
423 unsigned new_u64s)
424 {
425 const struct bkey_packed *end = btree_bkey_last(b, t);
426 struct btree_node_iter_set *set;
427 unsigned offset = __btree_node_key_to_offset(b, where);
428 int shift = new_u64s - clobber_u64s;
429 unsigned old_end = t->end_offset - shift;
430 unsigned orig_iter_pos = node_iter->data[0].k;
431 bool iter_current_key_modified =
432 orig_iter_pos >= offset &&
433 orig_iter_pos <= offset + clobber_u64s;
434
435 btree_node_iter_for_each(node_iter, set)
436 if (set->end == old_end)
437 goto found;
438
439 /* didn't find the bset in the iterator - might have to readd it: */
440 if (new_u64s &&
441 bkey_iter_pos_cmp(b, where, &path->pos) >= 0) {
442 bch2_btree_node_iter_push(node_iter, b, where, end);
443 goto fixup_done;
444 } else {
445 /* Iterator is after key that changed */
446 return;
447 }
448 found:
449 set->end = t->end_offset;
450
451 /* Iterator hasn't gotten to the key that changed yet: */
452 if (set->k < offset)
453 return;
454
455 if (new_u64s &&
456 bkey_iter_pos_cmp(b, where, &path->pos) >= 0) {
457 set->k = offset;
458 } else if (set->k < offset + clobber_u64s) {
459 set->k = offset + new_u64s;
460 if (set->k == set->end)
461 bch2_btree_node_iter_set_drop(node_iter, set);
462 } else {
463 /* Iterator is after key that changed */
464 set->k = (int) set->k + shift;
465 return;
466 }
467
468 bch2_btree_node_iter_sort(node_iter, b);
469 fixup_done:
470 if (node_iter->data[0].k != orig_iter_pos)
471 iter_current_key_modified = true;
472
473 /*
474 * When a new key is added, and the node iterator now points to that
475 * key, the iterator might have skipped past deleted keys that should
476 * come after the key the iterator now points to. We have to rewind to
477 * before those deleted keys - otherwise
478 * bch2_btree_node_iter_prev_all() breaks:
479 */
480 if (!bch2_btree_node_iter_end(node_iter) &&
481 iter_current_key_modified &&
482 b->c.level) {
483 struct bkey_packed *k, *k2, *p;
484
485 k = bch2_btree_node_iter_peek_all(node_iter, b);
486
487 for_each_bset(b, t) {
488 bool set_pos = false;
489
490 if (node_iter->data[0].end == t->end_offset)
491 continue;
492
493 k2 = bch2_btree_node_iter_bset_pos(node_iter, b, t);
494
495 while ((p = bch2_bkey_prev_all(b, t, k2)) &&
496 bkey_iter_cmp(b, k, p) < 0) {
497 k2 = p;
498 set_pos = true;
499 }
500
501 if (set_pos)
502 btree_node_iter_set_set_pos(node_iter,
503 b, t, k2);
504 }
505 }
506 }
507
bch2_btree_node_iter_fix(struct btree_trans * trans,struct btree_path * path,struct btree * b,struct btree_node_iter * node_iter,struct bkey_packed * where,unsigned clobber_u64s,unsigned new_u64s)508 void bch2_btree_node_iter_fix(struct btree_trans *trans,
509 struct btree_path *path,
510 struct btree *b,
511 struct btree_node_iter *node_iter,
512 struct bkey_packed *where,
513 unsigned clobber_u64s,
514 unsigned new_u64s)
515 {
516 struct bset_tree *t = bch2_bkey_to_bset_inlined(b, where);
517 struct btree_path *linked;
518 unsigned i;
519
520 if (node_iter != &path->l[b->c.level].iter) {
521 __bch2_btree_node_iter_fix(path, b, node_iter, t,
522 where, clobber_u64s, new_u64s);
523
524 if (bch2_debug_check_iterators)
525 bch2_btree_node_iter_verify(node_iter, b);
526 }
527
528 trans_for_each_path_with_node(trans, b, linked, i) {
529 __bch2_btree_node_iter_fix(linked, b,
530 &linked->l[b->c.level].iter, t,
531 where, clobber_u64s, new_u64s);
532 bch2_btree_path_verify_level(trans, linked, b->c.level);
533 }
534 }
535
536 /* Btree path level: pointer to a particular btree node and node iter */
537
__btree_iter_unpack(struct bch_fs * c,struct btree_path_level * l,struct bkey * u,struct bkey_packed * k)538 static inline struct bkey_s_c __btree_iter_unpack(struct bch_fs *c,
539 struct btree_path_level *l,
540 struct bkey *u,
541 struct bkey_packed *k)
542 {
543 if (unlikely(!k)) {
544 /*
545 * signal to bch2_btree_iter_peek_slot() that we're currently at
546 * a hole
547 */
548 u->type = KEY_TYPE_deleted;
549 return bkey_s_c_null;
550 }
551
552 return bkey_disassemble(l->b, k, u);
553 }
554
btree_path_level_peek_all(struct bch_fs * c,struct btree_path_level * l,struct bkey * u)555 static inline struct bkey_s_c btree_path_level_peek_all(struct bch_fs *c,
556 struct btree_path_level *l,
557 struct bkey *u)
558 {
559 return __btree_iter_unpack(c, l, u,
560 bch2_btree_node_iter_peek_all(&l->iter, l->b));
561 }
562
btree_path_level_peek(struct btree_trans * trans,struct btree_path * path,struct btree_path_level * l,struct bkey * u)563 static inline struct bkey_s_c btree_path_level_peek(struct btree_trans *trans,
564 struct btree_path *path,
565 struct btree_path_level *l,
566 struct bkey *u)
567 {
568 struct bkey_s_c k = __btree_iter_unpack(trans->c, l, u,
569 bch2_btree_node_iter_peek(&l->iter, l->b));
570
571 path->pos = k.k ? k.k->p : l->b->key.k.p;
572 trans->paths_sorted = false;
573 bch2_btree_path_verify_level(trans, path, l - path->l);
574 return k;
575 }
576
btree_path_level_prev(struct btree_trans * trans,struct btree_path * path,struct btree_path_level * l,struct bkey * u)577 static inline struct bkey_s_c btree_path_level_prev(struct btree_trans *trans,
578 struct btree_path *path,
579 struct btree_path_level *l,
580 struct bkey *u)
581 {
582 struct bkey_s_c k = __btree_iter_unpack(trans->c, l, u,
583 bch2_btree_node_iter_prev(&l->iter, l->b));
584
585 path->pos = k.k ? k.k->p : l->b->data->min_key;
586 trans->paths_sorted = false;
587 bch2_btree_path_verify_level(trans, path, l - path->l);
588 return k;
589 }
590
btree_path_advance_to_pos(struct btree_path * path,struct btree_path_level * l,int max_advance)591 static inline bool btree_path_advance_to_pos(struct btree_path *path,
592 struct btree_path_level *l,
593 int max_advance)
594 {
595 struct bkey_packed *k;
596 int nr_advanced = 0;
597
598 while ((k = bch2_btree_node_iter_peek_all(&l->iter, l->b)) &&
599 bkey_iter_pos_cmp(l->b, k, &path->pos) < 0) {
600 if (max_advance > 0 && nr_advanced >= max_advance)
601 return false;
602
603 bch2_btree_node_iter_advance(&l->iter, l->b);
604 nr_advanced++;
605 }
606
607 return true;
608 }
609
__btree_path_level_init(struct btree_path * path,unsigned level)610 static inline void __btree_path_level_init(struct btree_path *path,
611 unsigned level)
612 {
613 struct btree_path_level *l = &path->l[level];
614
615 bch2_btree_node_iter_init(&l->iter, l->b, &path->pos);
616
617 /*
618 * Iterators to interior nodes should always be pointed at the first non
619 * whiteout:
620 */
621 if (level)
622 bch2_btree_node_iter_peek(&l->iter, l->b);
623 }
624
bch2_btree_path_level_init(struct btree_trans * trans,struct btree_path * path,struct btree * b)625 void bch2_btree_path_level_init(struct btree_trans *trans,
626 struct btree_path *path,
627 struct btree *b)
628 {
629 BUG_ON(path->cached);
630
631 EBUG_ON(!btree_path_pos_in_node(path, b));
632
633 path->l[b->c.level].lock_seq = six_lock_seq(&b->c.lock);
634 path->l[b->c.level].b = b;
635 __btree_path_level_init(path, b->c.level);
636 }
637
638 /* Btree path: fixups after btree node updates: */
639
bch2_trans_revalidate_updates_in_node(struct btree_trans * trans,struct btree * b)640 static void bch2_trans_revalidate_updates_in_node(struct btree_trans *trans, struct btree *b)
641 {
642 struct bch_fs *c = trans->c;
643
644 trans_for_each_update(trans, i)
645 if (!i->cached &&
646 i->level == b->c.level &&
647 i->btree_id == b->c.btree_id &&
648 bpos_cmp(i->k->k.p, b->data->min_key) >= 0 &&
649 bpos_cmp(i->k->k.p, b->data->max_key) <= 0) {
650 i->old_v = bch2_btree_path_peek_slot(trans->paths + i->path, &i->old_k).v;
651
652 if (unlikely(trans->journal_replay_not_finished)) {
653 struct bkey_i *j_k =
654 bch2_journal_keys_peek_slot(c, i->btree_id, i->level,
655 i->k->k.p);
656
657 if (j_k) {
658 i->old_k = j_k->k;
659 i->old_v = &j_k->v;
660 }
661 }
662 }
663 }
664
665 /*
666 * A btree node is being replaced - update the iterator to point to the new
667 * node:
668 */
bch2_trans_node_add(struct btree_trans * trans,struct btree_path * path,struct btree * b)669 void bch2_trans_node_add(struct btree_trans *trans,
670 struct btree_path *path,
671 struct btree *b)
672 {
673 struct btree_path *prev;
674
675 BUG_ON(!btree_path_pos_in_node(path, b));
676
677 while ((prev = prev_btree_path(trans, path)) &&
678 btree_path_pos_in_node(prev, b))
679 path = prev;
680
681 for (;
682 path && btree_path_pos_in_node(path, b);
683 path = next_btree_path(trans, path))
684 if (path->uptodate == BTREE_ITER_UPTODATE && !path->cached) {
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 */
bch2_trans_node_reinit_iter(struct btree_trans * trans,struct btree * b)704 void bch2_trans_node_reinit_iter(struct btree_trans *trans, struct btree *b)
705 {
706 struct btree_path *path;
707 unsigned i;
708
709 trans_for_each_path_with_node(trans, b, path, i)
710 __btree_path_level_init(path, b->c.level);
711
712 bch2_trans_revalidate_updates_in_node(trans, b);
713 }
714
715 /* Btree path: traverse, set_pos: */
716
btree_path_lock_root(struct btree_trans * trans,struct btree_path * path,unsigned depth_want,unsigned long trace_ip)717 static inline int btree_path_lock_root(struct btree_trans *trans,
718 struct btree_path *path,
719 unsigned depth_want,
720 unsigned long trace_ip)
721 {
722 struct bch_fs *c = trans->c;
723 struct btree *b, **rootp = &bch2_btree_id_root(c, path->btree_id)->b;
724 enum six_lock_type lock_type;
725 unsigned i;
726 int ret;
727
728 EBUG_ON(path->nodes_locked);
729
730 while (1) {
731 b = READ_ONCE(*rootp);
732 path->level = READ_ONCE(b->c.level);
733
734 if (unlikely(path->level < depth_want)) {
735 /*
736 * the root is at a lower depth than the depth we want:
737 * got to the end of the btree, or we're walking nodes
738 * greater than some depth and there are no nodes >=
739 * that depth
740 */
741 path->level = depth_want;
742 for (i = path->level; i < BTREE_MAX_DEPTH; i++)
743 path->l[i].b = NULL;
744 return 1;
745 }
746
747 lock_type = __btree_lock_want(path, path->level);
748 ret = btree_node_lock(trans, path, &b->c,
749 path->level, lock_type, trace_ip);
750 if (unlikely(ret)) {
751 if (bch2_err_matches(ret, BCH_ERR_lock_fail_root_changed))
752 continue;
753 if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
754 return ret;
755 BUG();
756 }
757
758 if (likely(b == READ_ONCE(*rootp) &&
759 b->c.level == path->level &&
760 !race_fault())) {
761 for (i = 0; i < path->level; i++)
762 path->l[i].b = ERR_PTR(-BCH_ERR_no_btree_node_lock_root);
763 path->l[path->level].b = b;
764 for (i = path->level + 1; i < BTREE_MAX_DEPTH; i++)
765 path->l[i].b = NULL;
766
767 mark_btree_node_locked(trans, path, path->level,
768 (enum btree_node_locked_type) lock_type);
769 bch2_btree_path_level_init(trans, path, b);
770 return 0;
771 }
772
773 six_unlock_type(&b->c.lock, lock_type);
774 }
775 }
776
777 noinline
btree_path_prefetch(struct btree_trans * trans,struct btree_path * path)778 static int btree_path_prefetch(struct btree_trans *trans, struct btree_path *path)
779 {
780 struct bch_fs *c = trans->c;
781 struct btree_path_level *l = path_l(path);
782 struct btree_node_iter node_iter = l->iter;
783 struct bkey_packed *k;
784 struct bkey_buf tmp;
785 unsigned nr = test_bit(BCH_FS_started, &c->flags)
786 ? (path->level > 1 ? 0 : 2)
787 : (path->level > 1 ? 1 : 16);
788 bool was_locked = btree_node_locked(path, path->level);
789 int ret = 0;
790
791 bch2_bkey_buf_init(&tmp);
792
793 while (nr-- && !ret) {
794 if (!bch2_btree_node_relock(trans, path, path->level))
795 break;
796
797 bch2_btree_node_iter_advance(&node_iter, l->b);
798 k = bch2_btree_node_iter_peek(&node_iter, l->b);
799 if (!k)
800 break;
801
802 bch2_bkey_buf_unpack(&tmp, c, l->b, k);
803 ret = bch2_btree_node_prefetch(trans, path, tmp.k, path->btree_id,
804 path->level - 1);
805 }
806
807 if (!was_locked)
808 btree_node_unlock(trans, path, path->level);
809
810 bch2_bkey_buf_exit(&tmp, c);
811 return ret;
812 }
813
btree_path_prefetch_j(struct btree_trans * trans,struct btree_path * path,struct btree_and_journal_iter * jiter)814 static int btree_path_prefetch_j(struct btree_trans *trans, struct btree_path *path,
815 struct btree_and_journal_iter *jiter)
816 {
817 struct bch_fs *c = trans->c;
818 struct bkey_s_c k;
819 struct bkey_buf tmp;
820 unsigned nr = test_bit(BCH_FS_started, &c->flags)
821 ? (path->level > 1 ? 0 : 2)
822 : (path->level > 1 ? 1 : 16);
823 bool was_locked = btree_node_locked(path, path->level);
824 int ret = 0;
825
826 bch2_bkey_buf_init(&tmp);
827
828 while (nr-- && !ret) {
829 if (!bch2_btree_node_relock(trans, path, path->level))
830 break;
831
832 bch2_btree_and_journal_iter_advance(jiter);
833 k = bch2_btree_and_journal_iter_peek(jiter);
834 if (!k.k)
835 break;
836
837 bch2_bkey_buf_reassemble(&tmp, c, k);
838 ret = bch2_btree_node_prefetch(trans, path, tmp.k, path->btree_id,
839 path->level - 1);
840 }
841
842 if (!was_locked)
843 btree_node_unlock(trans, path, path->level);
844
845 bch2_bkey_buf_exit(&tmp, c);
846 return ret;
847 }
848
btree_node_mem_ptr_set(struct btree_trans * trans,struct btree_path * path,unsigned plevel,struct btree * b)849 static noinline void btree_node_mem_ptr_set(struct btree_trans *trans,
850 struct btree_path *path,
851 unsigned plevel, struct btree *b)
852 {
853 struct btree_path_level *l = &path->l[plevel];
854 bool locked = btree_node_locked(path, plevel);
855 struct bkey_packed *k;
856 struct bch_btree_ptr_v2 *bp;
857
858 if (!bch2_btree_node_relock(trans, path, plevel))
859 return;
860
861 k = bch2_btree_node_iter_peek_all(&l->iter, l->b);
862 BUG_ON(k->type != KEY_TYPE_btree_ptr_v2);
863
864 bp = (void *) bkeyp_val(&l->b->format, k);
865 bp->mem_ptr = (unsigned long)b;
866
867 if (!locked)
868 btree_node_unlock(trans, path, plevel);
869 }
870
btree_node_iter_and_journal_peek(struct btree_trans * trans,struct btree_path * path,unsigned flags,struct bkey_buf * out)871 static noinline int btree_node_iter_and_journal_peek(struct btree_trans *trans,
872 struct btree_path *path,
873 unsigned flags,
874 struct bkey_buf *out)
875 {
876 struct bch_fs *c = trans->c;
877 struct btree_path_level *l = path_l(path);
878 struct btree_and_journal_iter jiter;
879 struct bkey_s_c k;
880 int ret = 0;
881
882 __bch2_btree_and_journal_iter_init_node_iter(trans, &jiter, l->b, l->iter, path->pos);
883
884 k = bch2_btree_and_journal_iter_peek(&jiter);
885
886 bch2_bkey_buf_reassemble(out, c, k);
887
888 if ((flags & BTREE_ITER_prefetch) &&
889 c->opts.btree_node_prefetch)
890 ret = btree_path_prefetch_j(trans, path, &jiter);
891
892 bch2_btree_and_journal_iter_exit(&jiter);
893 return ret;
894 }
895
btree_path_down(struct btree_trans * trans,struct btree_path * path,unsigned flags,unsigned long trace_ip)896 static __always_inline int btree_path_down(struct btree_trans *trans,
897 struct btree_path *path,
898 unsigned flags,
899 unsigned long trace_ip)
900 {
901 struct bch_fs *c = trans->c;
902 struct btree_path_level *l = path_l(path);
903 struct btree *b;
904 unsigned level = path->level - 1;
905 enum six_lock_type lock_type = __btree_lock_want(path, level);
906 struct bkey_buf tmp;
907 int ret;
908
909 EBUG_ON(!btree_node_locked(path, path->level));
910
911 bch2_bkey_buf_init(&tmp);
912
913 if (unlikely(trans->journal_replay_not_finished)) {
914 ret = btree_node_iter_and_journal_peek(trans, path, flags, &tmp);
915 if (ret)
916 goto err;
917 } else {
918 struct bkey_packed *k = bch2_btree_node_iter_peek(&l->iter, l->b);
919 if (!k) {
920 struct printbuf buf = PRINTBUF;
921
922 prt_str(&buf, "node not found at pos ");
923 bch2_bpos_to_text(&buf, path->pos);
924 prt_str(&buf, " within parent node ");
925 bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(&l->b->key));
926
927 bch2_fs_fatal_error(c, "%s", buf.buf);
928 printbuf_exit(&buf);
929 ret = -BCH_ERR_btree_need_topology_repair;
930 goto err;
931 }
932
933 bch2_bkey_buf_unpack(&tmp, c, l->b, k);
934
935 if ((flags & BTREE_ITER_prefetch) &&
936 c->opts.btree_node_prefetch) {
937 ret = btree_path_prefetch(trans, path);
938 if (ret)
939 goto err;
940 }
941 }
942
943 b = bch2_btree_node_get(trans, path, tmp.k, level, lock_type, trace_ip);
944 ret = PTR_ERR_OR_ZERO(b);
945 if (unlikely(ret))
946 goto err;
947
948 if (likely(!trans->journal_replay_not_finished &&
949 tmp.k->k.type == KEY_TYPE_btree_ptr_v2) &&
950 unlikely(b != btree_node_mem_ptr(tmp.k)))
951 btree_node_mem_ptr_set(trans, path, level + 1, b);
952
953 if (btree_node_read_locked(path, level + 1))
954 btree_node_unlock(trans, path, level + 1);
955
956 mark_btree_node_locked(trans, path, level,
957 (enum btree_node_locked_type) lock_type);
958 path->level = level;
959 bch2_btree_path_level_init(trans, path, b);
960
961 bch2_btree_path_verify_locks(path);
962 err:
963 bch2_bkey_buf_exit(&tmp, c);
964 return ret;
965 }
966
bch2_btree_path_traverse_all(struct btree_trans * trans)967 static int bch2_btree_path_traverse_all(struct btree_trans *trans)
968 {
969 struct bch_fs *c = trans->c;
970 struct btree_path *path;
971 unsigned long trace_ip = _RET_IP_;
972 unsigned i;
973 int ret = 0;
974
975 if (trans->in_traverse_all)
976 return -BCH_ERR_transaction_restart_in_traverse_all;
977
978 trans->in_traverse_all = true;
979 retry_all:
980 trans->restarted = 0;
981 trans->last_restarted_ip = 0;
982
983 trans_for_each_path(trans, path, i)
984 path->should_be_locked = false;
985
986 btree_trans_sort_paths(trans);
987
988 bch2_trans_unlock(trans);
989 cond_resched();
990 trans_set_locked(trans);
991
992 if (unlikely(trans->memory_allocation_failure)) {
993 struct closure cl;
994
995 closure_init_stack(&cl);
996
997 do {
998 ret = bch2_btree_cache_cannibalize_lock(trans, &cl);
999 closure_sync(&cl);
1000 } while (ret);
1001 }
1002
1003 /* Now, redo traversals in correct order: */
1004 i = 0;
1005 while (i < trans->nr_sorted) {
1006 btree_path_idx_t idx = trans->sorted[i];
1007
1008 /*
1009 * Traversing a path can cause another path to be added at about
1010 * the same position:
1011 */
1012 if (trans->paths[idx].uptodate) {
1013 __btree_path_get(trans, &trans->paths[idx], false);
1014 ret = bch2_btree_path_traverse_one(trans, idx, 0, _THIS_IP_);
1015 __btree_path_put(trans, &trans->paths[idx], false);
1016
1017 if (bch2_err_matches(ret, BCH_ERR_transaction_restart) ||
1018 bch2_err_matches(ret, ENOMEM))
1019 goto retry_all;
1020 if (ret)
1021 goto err;
1022 } else {
1023 i++;
1024 }
1025 }
1026
1027 /*
1028 * We used to assert that all paths had been traversed here
1029 * (path->uptodate < BTREE_ITER_NEED_TRAVERSE); however, since
1030 * path->should_be_locked is not set yet, we might have unlocked and
1031 * then failed to relock a path - that's fine.
1032 */
1033 err:
1034 bch2_btree_cache_cannibalize_unlock(trans);
1035
1036 trans->in_traverse_all = false;
1037
1038 trace_and_count(c, trans_traverse_all, trans, trace_ip);
1039 return ret;
1040 }
1041
btree_path_check_pos_in_node(struct btree_path * path,unsigned l,int check_pos)1042 static inline bool btree_path_check_pos_in_node(struct btree_path *path,
1043 unsigned l, int check_pos)
1044 {
1045 if (check_pos < 0 && btree_path_pos_before_node(path, path->l[l].b))
1046 return false;
1047 if (check_pos > 0 && btree_path_pos_after_node(path, path->l[l].b))
1048 return false;
1049 return true;
1050 }
1051
btree_path_good_node(struct btree_trans * trans,struct btree_path * path,unsigned l,int check_pos)1052 static inline bool btree_path_good_node(struct btree_trans *trans,
1053 struct btree_path *path,
1054 unsigned l, int check_pos)
1055 {
1056 return is_btree_node(path, l) &&
1057 bch2_btree_node_relock(trans, path, l) &&
1058 btree_path_check_pos_in_node(path, l, check_pos);
1059 }
1060
btree_path_set_level_down(struct btree_trans * trans,struct btree_path * path,unsigned new_level)1061 static void btree_path_set_level_down(struct btree_trans *trans,
1062 struct btree_path *path,
1063 unsigned new_level)
1064 {
1065 unsigned l;
1066
1067 path->level = new_level;
1068
1069 for (l = path->level + 1; l < BTREE_MAX_DEPTH; l++)
1070 if (btree_lock_want(path, l) == BTREE_NODE_UNLOCKED)
1071 btree_node_unlock(trans, path, l);
1072
1073 btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE);
1074 bch2_btree_path_verify(trans, path);
1075 }
1076
__btree_path_up_until_good_node(struct btree_trans * trans,struct btree_path * path,int check_pos)1077 static noinline unsigned __btree_path_up_until_good_node(struct btree_trans *trans,
1078 struct btree_path *path,
1079 int check_pos)
1080 {
1081 unsigned i, l = path->level;
1082 again:
1083 while (btree_path_node(path, l) &&
1084 !btree_path_good_node(trans, path, l, check_pos))
1085 __btree_path_set_level_up(trans, path, l++);
1086
1087 /* If we need intent locks, take them too: */
1088 for (i = l + 1;
1089 i < path->locks_want && btree_path_node(path, i);
1090 i++)
1091 if (!bch2_btree_node_relock(trans, path, i)) {
1092 while (l <= i)
1093 __btree_path_set_level_up(trans, path, l++);
1094 goto again;
1095 }
1096
1097 return l;
1098 }
1099
btree_path_up_until_good_node(struct btree_trans * trans,struct btree_path * path,int check_pos)1100 static inline unsigned btree_path_up_until_good_node(struct btree_trans *trans,
1101 struct btree_path *path,
1102 int check_pos)
1103 {
1104 return likely(btree_node_locked(path, path->level) &&
1105 btree_path_check_pos_in_node(path, path->level, check_pos))
1106 ? path->level
1107 : __btree_path_up_until_good_node(trans, path, check_pos);
1108 }
1109
1110 /*
1111 * This is the main state machine for walking down the btree - walks down to a
1112 * specified depth
1113 *
1114 * Returns 0 on success, -EIO on error (error reading in a btree node).
1115 *
1116 * On error, caller (peek_node()/peek_key()) must return NULL; the error is
1117 * stashed in the iterator and returned from bch2_trans_exit().
1118 */
bch2_btree_path_traverse_one(struct btree_trans * trans,btree_path_idx_t path_idx,unsigned flags,unsigned long trace_ip)1119 int bch2_btree_path_traverse_one(struct btree_trans *trans,
1120 btree_path_idx_t path_idx,
1121 unsigned flags,
1122 unsigned long trace_ip)
1123 {
1124 struct btree_path *path = &trans->paths[path_idx];
1125 unsigned depth_want = path->level;
1126 int ret = -((int) trans->restarted);
1127
1128 if (unlikely(ret))
1129 goto out;
1130
1131 if (unlikely(!trans->srcu_held))
1132 bch2_trans_srcu_lock(trans);
1133
1134 trace_btree_path_traverse_start(trans, path);
1135
1136 /*
1137 * Ensure we obey path->should_be_locked: if it's set, we can't unlock
1138 * and re-traverse the path without a transaction restart:
1139 */
1140 if (path->should_be_locked) {
1141 ret = bch2_btree_path_relock(trans, path, trace_ip);
1142 goto out;
1143 }
1144
1145 if (path->cached) {
1146 ret = bch2_btree_path_traverse_cached(trans, path, flags);
1147 goto out;
1148 }
1149
1150 path = &trans->paths[path_idx];
1151
1152 if (unlikely(path->level >= BTREE_MAX_DEPTH))
1153 goto out_uptodate;
1154
1155 path->level = btree_path_up_until_good_node(trans, path, 0);
1156 unsigned max_level = path->level;
1157
1158 EBUG_ON(btree_path_node(path, path->level) &&
1159 !btree_node_locked(path, path->level));
1160
1161 /*
1162 * Note: path->nodes[path->level] may be temporarily NULL here - that
1163 * would indicate to other code that we got to the end of the btree,
1164 * here it indicates that relocking the root failed - it's critical that
1165 * btree_path_lock_root() comes next and that it can't fail
1166 */
1167 while (path->level > depth_want) {
1168 ret = btree_path_node(path, path->level)
1169 ? btree_path_down(trans, path, flags, trace_ip)
1170 : btree_path_lock_root(trans, path, depth_want, trace_ip);
1171 if (unlikely(ret)) {
1172 if (ret == 1) {
1173 /*
1174 * No nodes at this level - got to the end of
1175 * the btree:
1176 */
1177 ret = 0;
1178 goto out;
1179 }
1180
1181 __bch2_btree_path_unlock(trans, path);
1182 path->level = depth_want;
1183 path->l[path->level].b = ERR_PTR(ret);
1184 goto out;
1185 }
1186 }
1187
1188 if (unlikely(max_level > path->level)) {
1189 struct btree_path *linked;
1190 unsigned iter;
1191
1192 trans_for_each_path_with_node(trans, path_l(path)->b, linked, iter)
1193 for (unsigned j = path->level + 1; j < max_level; j++)
1194 linked->l[j] = path->l[j];
1195 }
1196
1197 out_uptodate:
1198 path->uptodate = BTREE_ITER_UPTODATE;
1199 trace_btree_path_traverse_end(trans, path);
1200 out:
1201 if (bch2_err_matches(ret, BCH_ERR_transaction_restart) != !!trans->restarted)
1202 panic("ret %s (%i) trans->restarted %s (%i)\n",
1203 bch2_err_str(ret), ret,
1204 bch2_err_str(trans->restarted), trans->restarted);
1205 bch2_btree_path_verify(trans, path);
1206 return ret;
1207 }
1208
btree_path_copy(struct btree_trans * trans,struct btree_path * dst,struct btree_path * src)1209 static inline void btree_path_copy(struct btree_trans *trans, struct btree_path *dst,
1210 struct btree_path *src)
1211 {
1212 unsigned i, offset = offsetof(struct btree_path, pos);
1213
1214 memcpy((void *) dst + offset,
1215 (void *) src + offset,
1216 sizeof(struct btree_path) - offset);
1217
1218 for (i = 0; i < BTREE_MAX_DEPTH; i++) {
1219 unsigned t = btree_node_locked_type(dst, i);
1220
1221 if (t != BTREE_NODE_UNLOCKED)
1222 six_lock_increment(&dst->l[i].b->c.lock, t);
1223 }
1224 }
1225
btree_path_clone(struct btree_trans * trans,btree_path_idx_t src,bool intent,unsigned long ip)1226 static btree_path_idx_t btree_path_clone(struct btree_trans *trans, btree_path_idx_t src,
1227 bool intent, unsigned long ip)
1228 {
1229 btree_path_idx_t new = btree_path_alloc(trans, src);
1230 btree_path_copy(trans, trans->paths + new, trans->paths + src);
1231 __btree_path_get(trans, trans->paths + new, intent);
1232 #ifdef TRACK_PATH_ALLOCATED
1233 trans->paths[new].ip_allocated = ip;
1234 #endif
1235 return new;
1236 }
1237
1238 __flatten
__bch2_btree_path_make_mut(struct btree_trans * trans,btree_path_idx_t path,bool intent,unsigned long ip)1239 btree_path_idx_t __bch2_btree_path_make_mut(struct btree_trans *trans,
1240 btree_path_idx_t path, bool intent, unsigned long ip)
1241 {
1242 struct btree_path *old = trans->paths + path;
1243 __btree_path_put(trans, trans->paths + path, intent);
1244 path = btree_path_clone(trans, path, intent, ip);
1245 trace_btree_path_clone(trans, old, trans->paths + path);
1246 trans->paths[path].preserve = false;
1247 return path;
1248 }
1249
1250 btree_path_idx_t __must_check
__bch2_btree_path_set_pos(struct btree_trans * trans,btree_path_idx_t path_idx,struct bpos new_pos,bool intent,unsigned long ip)1251 __bch2_btree_path_set_pos(struct btree_trans *trans,
1252 btree_path_idx_t path_idx, struct bpos new_pos,
1253 bool intent, unsigned long ip)
1254 {
1255 int cmp = bpos_cmp(new_pos, trans->paths[path_idx].pos);
1256
1257 bch2_trans_verify_not_in_restart(trans);
1258 EBUG_ON(!trans->paths[path_idx].ref);
1259
1260 trace_btree_path_set_pos(trans, trans->paths + path_idx, &new_pos);
1261
1262 path_idx = bch2_btree_path_make_mut(trans, path_idx, intent, ip);
1263
1264 struct btree_path *path = trans->paths + path_idx;
1265 path->pos = new_pos;
1266 trans->paths_sorted = false;
1267
1268 if (unlikely(path->cached)) {
1269 btree_node_unlock(trans, path, 0);
1270 path->l[0].b = ERR_PTR(-BCH_ERR_no_btree_node_up);
1271 btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE);
1272 goto out;
1273 }
1274
1275 unsigned level = btree_path_up_until_good_node(trans, path, cmp);
1276
1277 if (btree_path_node(path, level)) {
1278 struct btree_path_level *l = &path->l[level];
1279
1280 BUG_ON(!btree_node_locked(path, level));
1281 /*
1282 * We might have to skip over many keys, or just a few: try
1283 * advancing the node iterator, and if we have to skip over too
1284 * many keys just reinit it (or if we're rewinding, since that
1285 * is expensive).
1286 */
1287 if (cmp < 0 ||
1288 !btree_path_advance_to_pos(path, l, 8))
1289 bch2_btree_node_iter_init(&l->iter, l->b, &path->pos);
1290
1291 /*
1292 * Iterators to interior nodes should always be pointed at the first non
1293 * whiteout:
1294 */
1295 if (unlikely(level))
1296 bch2_btree_node_iter_peek(&l->iter, l->b);
1297 }
1298
1299 if (unlikely(level != path->level)) {
1300 btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE);
1301 __bch2_btree_path_unlock(trans, path);
1302 }
1303 out:
1304 bch2_btree_path_verify(trans, path);
1305 return path_idx;
1306 }
1307
1308 /* Btree path: main interface: */
1309
have_path_at_pos(struct btree_trans * trans,struct btree_path * path)1310 static struct btree_path *have_path_at_pos(struct btree_trans *trans, struct btree_path *path)
1311 {
1312 struct btree_path *sib;
1313
1314 sib = prev_btree_path(trans, path);
1315 if (sib && !btree_path_cmp(sib, path))
1316 return sib;
1317
1318 sib = next_btree_path(trans, path);
1319 if (sib && !btree_path_cmp(sib, path))
1320 return sib;
1321
1322 return NULL;
1323 }
1324
have_node_at_pos(struct btree_trans * trans,struct btree_path * path)1325 static struct btree_path *have_node_at_pos(struct btree_trans *trans, struct btree_path *path)
1326 {
1327 struct btree_path *sib;
1328
1329 sib = prev_btree_path(trans, path);
1330 if (sib && sib->level == path->level && path_l(sib)->b == path_l(path)->b)
1331 return sib;
1332
1333 sib = next_btree_path(trans, path);
1334 if (sib && sib->level == path->level && path_l(sib)->b == path_l(path)->b)
1335 return sib;
1336
1337 return NULL;
1338 }
1339
__bch2_path_free(struct btree_trans * trans,btree_path_idx_t path)1340 static inline void __bch2_path_free(struct btree_trans *trans, btree_path_idx_t path)
1341 {
1342 __bch2_btree_path_unlock(trans, trans->paths + path);
1343 btree_path_list_remove(trans, trans->paths + path);
1344 __clear_bit(path, trans->paths_allocated);
1345 }
1346
bch2_btree_path_can_relock(struct btree_trans * trans,struct btree_path * path)1347 static bool bch2_btree_path_can_relock(struct btree_trans *trans, struct btree_path *path)
1348 {
1349 unsigned l = path->level;
1350
1351 do {
1352 if (!btree_path_node(path, l))
1353 break;
1354
1355 if (!is_btree_node(path, l))
1356 return false;
1357
1358 if (path->l[l].lock_seq != path->l[l].b->c.lock.seq)
1359 return false;
1360
1361 l++;
1362 } while (l < path->locks_want);
1363
1364 return true;
1365 }
1366
bch2_path_put(struct btree_trans * trans,btree_path_idx_t path_idx,bool intent)1367 void bch2_path_put(struct btree_trans *trans, btree_path_idx_t path_idx, bool intent)
1368 {
1369 struct btree_path *path = trans->paths + path_idx, *dup;
1370
1371 if (!__btree_path_put(trans, path, intent))
1372 return;
1373
1374 dup = path->preserve
1375 ? have_path_at_pos(trans, path)
1376 : have_node_at_pos(trans, path);
1377
1378 trace_btree_path_free(trans, path_idx, dup);
1379
1380 if (!dup && !(!path->preserve && !is_btree_node(path, path->level)))
1381 return;
1382
1383 if (path->should_be_locked && !trans->restarted) {
1384 if (!dup)
1385 return;
1386
1387 if (!(trans->locked
1388 ? bch2_btree_path_relock_norestart(trans, dup)
1389 : bch2_btree_path_can_relock(trans, dup)))
1390 return;
1391 }
1392
1393 if (dup) {
1394 dup->preserve |= path->preserve;
1395 dup->should_be_locked |= path->should_be_locked;
1396 }
1397
1398 __bch2_path_free(trans, path_idx);
1399 }
1400
bch2_path_put_nokeep(struct btree_trans * trans,btree_path_idx_t path,bool intent)1401 static void bch2_path_put_nokeep(struct btree_trans *trans, btree_path_idx_t path,
1402 bool intent)
1403 {
1404 if (!__btree_path_put(trans, trans->paths + path, intent))
1405 return;
1406
1407 __bch2_path_free(trans, path);
1408 }
1409
bch2_trans_restart_error(struct btree_trans * trans,u32 restart_count)1410 void __noreturn bch2_trans_restart_error(struct btree_trans *trans, u32 restart_count)
1411 {
1412 panic("trans->restart_count %u, should be %u, last restarted by %pS\n",
1413 trans->restart_count, restart_count,
1414 (void *) trans->last_begin_ip);
1415 }
1416
bch2_trans_in_restart_error(struct btree_trans * trans)1417 void __noreturn bch2_trans_in_restart_error(struct btree_trans *trans)
1418 {
1419 panic("in transaction restart: %s, last restarted by %pS\n",
1420 bch2_err_str(trans->restarted),
1421 (void *) trans->last_restarted_ip);
1422 }
1423
bch2_trans_unlocked_error(struct btree_trans * trans)1424 void __noreturn bch2_trans_unlocked_error(struct btree_trans *trans)
1425 {
1426 panic("trans should be locked, unlocked by %pS\n",
1427 (void *) trans->last_unlock_ip);
1428 }
1429
1430 noinline __cold
bch2_trans_updates_to_text(struct printbuf * buf,struct btree_trans * trans)1431 void bch2_trans_updates_to_text(struct printbuf *buf, struct btree_trans *trans)
1432 {
1433 prt_printf(buf, "%u transaction updates for %s journal seq %llu\n",
1434 trans->nr_updates, trans->fn, trans->journal_res.seq);
1435 printbuf_indent_add(buf, 2);
1436
1437 trans_for_each_update(trans, i) {
1438 struct bkey_s_c old = { &i->old_k, i->old_v };
1439
1440 prt_printf(buf, "update: btree=%s cached=%u %pS\n",
1441 bch2_btree_id_str(i->btree_id),
1442 i->cached,
1443 (void *) i->ip_allocated);
1444
1445 prt_printf(buf, " old ");
1446 bch2_bkey_val_to_text(buf, trans->c, old);
1447 prt_newline(buf);
1448
1449 prt_printf(buf, " new ");
1450 bch2_bkey_val_to_text(buf, trans->c, bkey_i_to_s_c(i->k));
1451 prt_newline(buf);
1452 }
1453
1454 for (struct jset_entry *e = trans->journal_entries;
1455 e != btree_trans_journal_entries_top(trans);
1456 e = vstruct_next(e))
1457 bch2_journal_entry_to_text(buf, trans->c, e);
1458
1459 printbuf_indent_sub(buf, 2);
1460 }
1461
1462 noinline __cold
bch2_dump_trans_updates(struct btree_trans * trans)1463 void bch2_dump_trans_updates(struct btree_trans *trans)
1464 {
1465 struct printbuf buf = PRINTBUF;
1466
1467 bch2_trans_updates_to_text(&buf, trans);
1468 bch2_print_str(trans->c, buf.buf);
1469 printbuf_exit(&buf);
1470 }
1471
bch2_btree_path_to_text_short(struct printbuf * out,struct btree_trans * trans,btree_path_idx_t path_idx)1472 static void bch2_btree_path_to_text_short(struct printbuf *out, struct btree_trans *trans, btree_path_idx_t path_idx)
1473 {
1474 struct btree_path *path = trans->paths + path_idx;
1475
1476 prt_printf(out, "path: idx %3u ref %u:%u %c %c %c btree=%s l=%u pos ",
1477 path_idx, path->ref, path->intent_ref,
1478 path->preserve ? 'P' : ' ',
1479 path->should_be_locked ? 'S' : ' ',
1480 path->cached ? 'C' : 'B',
1481 bch2_btree_id_str(path->btree_id),
1482 path->level);
1483 bch2_bpos_to_text(out, path->pos);
1484
1485 if (!path->cached && btree_node_locked(path, path->level)) {
1486 prt_char(out, ' ');
1487 struct btree *b = path_l(path)->b;
1488 bch2_bpos_to_text(out, b->data->min_key);
1489 prt_char(out, '-');
1490 bch2_bpos_to_text(out, b->key.k.p);
1491 }
1492
1493 #ifdef TRACK_PATH_ALLOCATED
1494 prt_printf(out, " %pS", (void *) path->ip_allocated);
1495 #endif
1496 }
1497
btree_node_locked_str(enum btree_node_locked_type t)1498 static const char *btree_node_locked_str(enum btree_node_locked_type t)
1499 {
1500 switch (t) {
1501 case BTREE_NODE_UNLOCKED:
1502 return "unlocked";
1503 case BTREE_NODE_READ_LOCKED:
1504 return "read";
1505 case BTREE_NODE_INTENT_LOCKED:
1506 return "intent";
1507 case BTREE_NODE_WRITE_LOCKED:
1508 return "write";
1509 default:
1510 return NULL;
1511 }
1512 }
1513
bch2_btree_path_to_text(struct printbuf * out,struct btree_trans * trans,btree_path_idx_t path_idx)1514 void bch2_btree_path_to_text(struct printbuf *out, struct btree_trans *trans, btree_path_idx_t path_idx)
1515 {
1516 bch2_btree_path_to_text_short(out, trans, path_idx);
1517
1518 struct btree_path *path = trans->paths + path_idx;
1519
1520 prt_printf(out, " uptodate %u locks_want %u", path->uptodate, path->locks_want);
1521 prt_newline(out);
1522
1523 printbuf_indent_add(out, 2);
1524 for (unsigned l = 0; l < BTREE_MAX_DEPTH; l++) {
1525 prt_printf(out, "l=%u locks %s seq %u node ", l,
1526 btree_node_locked_str(btree_node_locked_type(path, l)),
1527 path->l[l].lock_seq);
1528
1529 int ret = PTR_ERR_OR_ZERO(path->l[l].b);
1530 if (ret)
1531 prt_str(out, bch2_err_str(ret));
1532 else
1533 prt_printf(out, "%px", path->l[l].b);
1534 prt_newline(out);
1535 }
1536 printbuf_indent_sub(out, 2);
1537 }
1538
1539 static noinline __cold
__bch2_trans_paths_to_text(struct printbuf * out,struct btree_trans * trans,bool nosort)1540 void __bch2_trans_paths_to_text(struct printbuf *out, struct btree_trans *trans,
1541 bool nosort)
1542 {
1543 struct trans_for_each_path_inorder_iter iter;
1544
1545 if (!nosort)
1546 btree_trans_sort_paths(trans);
1547
1548 trans_for_each_path_idx_inorder(trans, iter) {
1549 bch2_btree_path_to_text_short(out, trans, iter.path_idx);
1550 prt_newline(out);
1551 }
1552 }
1553
1554 noinline __cold
bch2_trans_paths_to_text(struct printbuf * out,struct btree_trans * trans)1555 void bch2_trans_paths_to_text(struct printbuf *out, struct btree_trans *trans)
1556 {
1557 __bch2_trans_paths_to_text(out, trans, false);
1558 }
1559
1560 static noinline __cold
__bch2_dump_trans_paths_updates(struct btree_trans * trans,bool nosort)1561 void __bch2_dump_trans_paths_updates(struct btree_trans *trans, bool nosort)
1562 {
1563 struct printbuf buf = PRINTBUF;
1564
1565 __bch2_trans_paths_to_text(&buf, trans, nosort);
1566 bch2_trans_updates_to_text(&buf, trans);
1567
1568 bch2_print_str(trans->c, buf.buf);
1569 printbuf_exit(&buf);
1570 }
1571
1572 noinline __cold
bch2_dump_trans_paths_updates(struct btree_trans * trans)1573 void bch2_dump_trans_paths_updates(struct btree_trans *trans)
1574 {
1575 __bch2_dump_trans_paths_updates(trans, false);
1576 }
1577
1578 noinline __cold
bch2_trans_update_max_paths(struct btree_trans * trans)1579 static void bch2_trans_update_max_paths(struct btree_trans *trans)
1580 {
1581 struct btree_transaction_stats *s = btree_trans_stats(trans);
1582 struct printbuf buf = PRINTBUF;
1583 size_t nr = bitmap_weight(trans->paths_allocated, trans->nr_paths);
1584
1585 bch2_trans_paths_to_text(&buf, trans);
1586
1587 if (!buf.allocation_failure) {
1588 mutex_lock(&s->lock);
1589 if (nr > s->nr_max_paths) {
1590 s->nr_max_paths = nr;
1591 swap(s->max_paths_text, buf.buf);
1592 }
1593 mutex_unlock(&s->lock);
1594 }
1595
1596 printbuf_exit(&buf);
1597
1598 trans->nr_paths_max = nr;
1599 }
1600
1601 noinline __cold
__bch2_btree_trans_too_many_iters(struct btree_trans * trans)1602 int __bch2_btree_trans_too_many_iters(struct btree_trans *trans)
1603 {
1604 if (trace_trans_restart_too_many_iters_enabled()) {
1605 struct printbuf buf = PRINTBUF;
1606
1607 bch2_trans_paths_to_text(&buf, trans);
1608 trace_trans_restart_too_many_iters(trans, _THIS_IP_, buf.buf);
1609 printbuf_exit(&buf);
1610 }
1611
1612 count_event(trans->c, trans_restart_too_many_iters);
1613
1614 return btree_trans_restart(trans, BCH_ERR_transaction_restart_too_many_iters);
1615 }
1616
btree_path_overflow(struct btree_trans * trans)1617 static noinline void btree_path_overflow(struct btree_trans *trans)
1618 {
1619 bch2_dump_trans_paths_updates(trans);
1620 bch_err(trans->c, "trans path overflow");
1621 }
1622
btree_paths_realloc(struct btree_trans * trans)1623 static noinline void btree_paths_realloc(struct btree_trans *trans)
1624 {
1625 unsigned nr = trans->nr_paths * 2;
1626
1627 void *p = kvzalloc(BITS_TO_LONGS(nr) * sizeof(unsigned long) +
1628 sizeof(struct btree_trans_paths) +
1629 nr * sizeof(struct btree_path) +
1630 nr * sizeof(btree_path_idx_t) + 8 +
1631 nr * sizeof(struct btree_insert_entry), GFP_KERNEL|__GFP_NOFAIL);
1632
1633 unsigned long *paths_allocated = p;
1634 memcpy(paths_allocated, trans->paths_allocated, BITS_TO_LONGS(trans->nr_paths) * sizeof(unsigned long));
1635 p += BITS_TO_LONGS(nr) * sizeof(unsigned long);
1636
1637 p += sizeof(struct btree_trans_paths);
1638 struct btree_path *paths = p;
1639 *trans_paths_nr(paths) = nr;
1640 memcpy(paths, trans->paths, trans->nr_paths * sizeof(struct btree_path));
1641 p += nr * sizeof(struct btree_path);
1642
1643 btree_path_idx_t *sorted = p;
1644 memcpy(sorted, trans->sorted, trans->nr_sorted * sizeof(btree_path_idx_t));
1645 p += nr * sizeof(btree_path_idx_t) + 8;
1646
1647 struct btree_insert_entry *updates = p;
1648 memcpy(updates, trans->updates, trans->nr_paths * sizeof(struct btree_insert_entry));
1649
1650 unsigned long *old = trans->paths_allocated;
1651
1652 rcu_assign_pointer(trans->paths_allocated, paths_allocated);
1653 rcu_assign_pointer(trans->paths, paths);
1654 rcu_assign_pointer(trans->sorted, sorted);
1655 rcu_assign_pointer(trans->updates, updates);
1656
1657 trans->nr_paths = nr;
1658
1659 if (old != trans->_paths_allocated)
1660 kfree_rcu_mightsleep(old);
1661 }
1662
btree_path_alloc(struct btree_trans * trans,btree_path_idx_t pos)1663 static inline btree_path_idx_t btree_path_alloc(struct btree_trans *trans,
1664 btree_path_idx_t pos)
1665 {
1666 btree_path_idx_t idx = find_first_zero_bit(trans->paths_allocated, trans->nr_paths);
1667
1668 if (unlikely(idx == trans->nr_paths)) {
1669 if (trans->nr_paths == BTREE_ITER_MAX) {
1670 btree_path_overflow(trans);
1671 return 0;
1672 }
1673
1674 btree_paths_realloc(trans);
1675 }
1676
1677 /*
1678 * Do this before marking the new path as allocated, since it won't be
1679 * initialized yet:
1680 */
1681 if (unlikely(idx > trans->nr_paths_max))
1682 bch2_trans_update_max_paths(trans);
1683
1684 __set_bit(idx, trans->paths_allocated);
1685
1686 struct btree_path *path = &trans->paths[idx];
1687 path->ref = 0;
1688 path->intent_ref = 0;
1689 path->nodes_locked = 0;
1690
1691 btree_path_list_add(trans, pos, idx);
1692 trans->paths_sorted = false;
1693 return idx;
1694 }
1695
bch2_path_get(struct btree_trans * trans,enum btree_id btree_id,struct bpos pos,unsigned locks_want,unsigned level,unsigned flags,unsigned long ip)1696 btree_path_idx_t bch2_path_get(struct btree_trans *trans,
1697 enum btree_id btree_id, struct bpos pos,
1698 unsigned locks_want, unsigned level,
1699 unsigned flags, unsigned long ip)
1700 {
1701 struct btree_path *path;
1702 bool cached = flags & BTREE_ITER_cached;
1703 bool intent = flags & BTREE_ITER_intent;
1704 struct trans_for_each_path_inorder_iter iter;
1705 btree_path_idx_t path_pos = 0, path_idx;
1706
1707 bch2_trans_verify_not_unlocked(trans);
1708 bch2_trans_verify_not_in_restart(trans);
1709 bch2_trans_verify_locks(trans);
1710
1711 btree_trans_sort_paths(trans);
1712
1713 trans_for_each_path_inorder(trans, path, iter) {
1714 if (__btree_path_cmp(path,
1715 btree_id,
1716 cached,
1717 pos,
1718 level) > 0)
1719 break;
1720
1721 path_pos = iter.path_idx;
1722 }
1723
1724 if (path_pos &&
1725 trans->paths[path_pos].cached == cached &&
1726 trans->paths[path_pos].btree_id == btree_id &&
1727 trans->paths[path_pos].level == level) {
1728 trace_btree_path_get(trans, trans->paths + path_pos, &pos);
1729
1730 __btree_path_get(trans, trans->paths + path_pos, intent);
1731 path_idx = bch2_btree_path_set_pos(trans, path_pos, pos, intent, ip);
1732 path = trans->paths + path_idx;
1733 } else {
1734 path_idx = btree_path_alloc(trans, path_pos);
1735 path = trans->paths + path_idx;
1736
1737 __btree_path_get(trans, path, intent);
1738 path->pos = pos;
1739 path->btree_id = btree_id;
1740 path->cached = cached;
1741 path->uptodate = BTREE_ITER_NEED_TRAVERSE;
1742 path->should_be_locked = false;
1743 path->level = level;
1744 path->locks_want = locks_want;
1745 path->nodes_locked = 0;
1746 for (unsigned i = 0; i < ARRAY_SIZE(path->l); i++)
1747 path->l[i].b = ERR_PTR(-BCH_ERR_no_btree_node_init);
1748 #ifdef TRACK_PATH_ALLOCATED
1749 path->ip_allocated = ip;
1750 #endif
1751 trans->paths_sorted = false;
1752
1753 trace_btree_path_alloc(trans, path);
1754 }
1755
1756 if (!(flags & BTREE_ITER_nopreserve))
1757 path->preserve = true;
1758
1759 if (path->intent_ref)
1760 locks_want = max(locks_want, level + 1);
1761
1762 /*
1763 * If the path has locks_want greater than requested, we don't downgrade
1764 * it here - on transaction restart because btree node split needs to
1765 * upgrade locks, we might be putting/getting the iterator again.
1766 * Downgrading iterators only happens via bch2_trans_downgrade(), after
1767 * a successful transaction commit.
1768 */
1769
1770 locks_want = min(locks_want, BTREE_MAX_DEPTH);
1771 if (locks_want > path->locks_want)
1772 bch2_btree_path_upgrade_noupgrade_sibs(trans, path, locks_want, NULL);
1773
1774 return path_idx;
1775 }
1776
bch2_path_get_unlocked_mut(struct btree_trans * trans,enum btree_id btree_id,unsigned level,struct bpos pos)1777 btree_path_idx_t bch2_path_get_unlocked_mut(struct btree_trans *trans,
1778 enum btree_id btree_id,
1779 unsigned level,
1780 struct bpos pos)
1781 {
1782 btree_path_idx_t path_idx = bch2_path_get(trans, btree_id, pos, level + 1, level,
1783 BTREE_ITER_nopreserve|
1784 BTREE_ITER_intent, _RET_IP_);
1785 path_idx = bch2_btree_path_make_mut(trans, path_idx, true, _RET_IP_);
1786
1787 struct btree_path *path = trans->paths + path_idx;
1788 bch2_btree_path_downgrade(trans, path);
1789 __bch2_btree_path_unlock(trans, path);
1790 return path_idx;
1791 }
1792
bch2_btree_path_peek_slot(struct btree_path * path,struct bkey * u)1793 struct bkey_s_c bch2_btree_path_peek_slot(struct btree_path *path, struct bkey *u)
1794 {
1795
1796 struct btree_path_level *l = path_l(path);
1797 struct bkey_packed *_k;
1798 struct bkey_s_c k;
1799
1800 if (unlikely(!l->b))
1801 return bkey_s_c_null;
1802
1803 EBUG_ON(path->uptodate != BTREE_ITER_UPTODATE);
1804 EBUG_ON(!btree_node_locked(path, path->level));
1805
1806 if (!path->cached) {
1807 _k = bch2_btree_node_iter_peek_all(&l->iter, l->b);
1808 k = _k ? bkey_disassemble(l->b, _k, u) : bkey_s_c_null;
1809
1810 EBUG_ON(k.k && bkey_deleted(k.k) && bpos_eq(k.k->p, path->pos));
1811
1812 if (!k.k || !bpos_eq(path->pos, k.k->p))
1813 goto hole;
1814 } else {
1815 struct bkey_cached *ck = (void *) path->l[0].b;
1816 if (!ck)
1817 return bkey_s_c_null;
1818
1819 EBUG_ON(path->btree_id != ck->key.btree_id ||
1820 !bkey_eq(path->pos, ck->key.pos));
1821
1822 *u = ck->k->k;
1823 k = bkey_i_to_s_c(ck->k);
1824 }
1825
1826 return k;
1827 hole:
1828 bkey_init(u);
1829 u->p = path->pos;
1830 return (struct bkey_s_c) { u, NULL };
1831 }
1832
1833
bch2_set_btree_iter_dontneed(struct btree_iter * iter)1834 void bch2_set_btree_iter_dontneed(struct btree_iter *iter)
1835 {
1836 struct btree_trans *trans = iter->trans;
1837
1838 if (!iter->path || trans->restarted)
1839 return;
1840
1841 struct btree_path *path = btree_iter_path(trans, iter);
1842 path->preserve = false;
1843 if (path->ref == 1)
1844 path->should_be_locked = false;
1845 }
1846 /* Btree iterators: */
1847
1848 int __must_check
__bch2_btree_iter_traverse(struct btree_iter * iter)1849 __bch2_btree_iter_traverse(struct btree_iter *iter)
1850 {
1851 return bch2_btree_path_traverse(iter->trans, iter->path, iter->flags);
1852 }
1853
1854 int __must_check
bch2_btree_iter_traverse(struct btree_iter * iter)1855 bch2_btree_iter_traverse(struct btree_iter *iter)
1856 {
1857 struct btree_trans *trans = iter->trans;
1858 int ret;
1859
1860 bch2_trans_verify_not_unlocked(trans);
1861
1862 iter->path = bch2_btree_path_set_pos(trans, iter->path,
1863 btree_iter_search_key(iter),
1864 iter->flags & BTREE_ITER_intent,
1865 btree_iter_ip_allocated(iter));
1866
1867 ret = bch2_btree_path_traverse(iter->trans, iter->path, iter->flags);
1868 if (ret)
1869 return ret;
1870
1871 struct btree_path *path = btree_iter_path(trans, iter);
1872 if (btree_path_node(path, path->level))
1873 btree_path_set_should_be_locked(trans, path);
1874 return 0;
1875 }
1876
1877 /* Iterate across nodes (leaf and interior nodes) */
1878
bch2_btree_iter_peek_node(struct btree_iter * iter)1879 struct btree *bch2_btree_iter_peek_node(struct btree_iter *iter)
1880 {
1881 struct btree_trans *trans = iter->trans;
1882 struct btree *b = NULL;
1883 int ret;
1884
1885 EBUG_ON(trans->paths[iter->path].cached);
1886 bch2_btree_iter_verify(iter);
1887
1888 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
1889 if (ret)
1890 goto err;
1891
1892 struct btree_path *path = btree_iter_path(trans, iter);
1893 b = btree_path_node(path, path->level);
1894 if (!b)
1895 goto out;
1896
1897 BUG_ON(bpos_lt(b->key.k.p, iter->pos));
1898
1899 bkey_init(&iter->k);
1900 iter->k.p = iter->pos = b->key.k.p;
1901
1902 iter->path = bch2_btree_path_set_pos(trans, iter->path, b->key.k.p,
1903 iter->flags & BTREE_ITER_intent,
1904 btree_iter_ip_allocated(iter));
1905 btree_path_set_should_be_locked(trans, btree_iter_path(trans, iter));
1906 out:
1907 bch2_btree_iter_verify_entry_exit(iter);
1908 bch2_btree_iter_verify(iter);
1909
1910 return b;
1911 err:
1912 b = ERR_PTR(ret);
1913 goto out;
1914 }
1915
1916 /* Only kept for -tools */
bch2_btree_iter_peek_node_and_restart(struct btree_iter * iter)1917 struct btree *bch2_btree_iter_peek_node_and_restart(struct btree_iter *iter)
1918 {
1919 struct btree *b;
1920
1921 while (b = bch2_btree_iter_peek_node(iter),
1922 bch2_err_matches(PTR_ERR_OR_ZERO(b), BCH_ERR_transaction_restart))
1923 bch2_trans_begin(iter->trans);
1924
1925 return b;
1926 }
1927
bch2_btree_iter_next_node(struct btree_iter * iter)1928 struct btree *bch2_btree_iter_next_node(struct btree_iter *iter)
1929 {
1930 struct btree_trans *trans = iter->trans;
1931 struct btree *b = NULL;
1932 int ret;
1933
1934 EBUG_ON(trans->paths[iter->path].cached);
1935 bch2_trans_verify_not_in_restart(trans);
1936 bch2_btree_iter_verify(iter);
1937
1938 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
1939 if (ret)
1940 goto err;
1941
1942
1943 struct btree_path *path = btree_iter_path(trans, iter);
1944
1945 /* already at end? */
1946 if (!btree_path_node(path, path->level))
1947 return NULL;
1948
1949 /* got to end? */
1950 if (!btree_path_node(path, path->level + 1)) {
1951 btree_path_set_level_up(trans, path);
1952 return NULL;
1953 }
1954
1955 if (!bch2_btree_node_relock(trans, path, path->level + 1)) {
1956 __bch2_btree_path_unlock(trans, path);
1957 path->l[path->level].b = ERR_PTR(-BCH_ERR_no_btree_node_relock);
1958 path->l[path->level + 1].b = ERR_PTR(-BCH_ERR_no_btree_node_relock);
1959 btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE);
1960 trace_and_count(trans->c, trans_restart_relock_next_node, trans, _THIS_IP_, path);
1961 ret = btree_trans_restart(trans, BCH_ERR_transaction_restart_relock);
1962 goto err;
1963 }
1964
1965 b = btree_path_node(path, path->level + 1);
1966
1967 if (bpos_eq(iter->pos, b->key.k.p)) {
1968 __btree_path_set_level_up(trans, path, path->level++);
1969 } else {
1970 if (btree_lock_want(path, path->level + 1) == BTREE_NODE_UNLOCKED)
1971 btree_node_unlock(trans, path, path->level + 1);
1972
1973 /*
1974 * Haven't gotten to the end of the parent node: go back down to
1975 * the next child node
1976 */
1977 iter->path = bch2_btree_path_set_pos(trans, iter->path,
1978 bpos_successor(iter->pos),
1979 iter->flags & BTREE_ITER_intent,
1980 btree_iter_ip_allocated(iter));
1981
1982 path = btree_iter_path(trans, iter);
1983 btree_path_set_level_down(trans, path, iter->min_depth);
1984
1985 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
1986 if (ret)
1987 goto err;
1988
1989 path = btree_iter_path(trans, iter);
1990 b = path->l[path->level].b;
1991 }
1992
1993 bkey_init(&iter->k);
1994 iter->k.p = iter->pos = b->key.k.p;
1995
1996 iter->path = bch2_btree_path_set_pos(trans, iter->path, b->key.k.p,
1997 iter->flags & BTREE_ITER_intent,
1998 btree_iter_ip_allocated(iter));
1999 btree_path_set_should_be_locked(trans, btree_iter_path(trans, iter));
2000 EBUG_ON(btree_iter_path(trans, iter)->uptodate);
2001 out:
2002 bch2_btree_iter_verify_entry_exit(iter);
2003 bch2_btree_iter_verify(iter);
2004
2005 return b;
2006 err:
2007 b = ERR_PTR(ret);
2008 goto out;
2009 }
2010
2011 /* Iterate across keys (in leaf nodes only) */
2012
bch2_btree_iter_advance(struct btree_iter * iter)2013 inline bool bch2_btree_iter_advance(struct btree_iter *iter)
2014 {
2015 struct bpos pos = iter->k.p;
2016 bool ret = !(iter->flags & BTREE_ITER_all_snapshots
2017 ? bpos_eq(pos, SPOS_MAX)
2018 : bkey_eq(pos, SPOS_MAX));
2019
2020 if (ret && !(iter->flags & BTREE_ITER_is_extents))
2021 pos = bkey_successor(iter, pos);
2022 bch2_btree_iter_set_pos(iter, pos);
2023 return ret;
2024 }
2025
bch2_btree_iter_rewind(struct btree_iter * iter)2026 inline bool bch2_btree_iter_rewind(struct btree_iter *iter)
2027 {
2028 struct bpos pos = bkey_start_pos(&iter->k);
2029 bool ret = !(iter->flags & BTREE_ITER_all_snapshots
2030 ? bpos_eq(pos, POS_MIN)
2031 : bkey_eq(pos, POS_MIN));
2032
2033 if (ret && !(iter->flags & BTREE_ITER_is_extents))
2034 pos = bkey_predecessor(iter, pos);
2035 bch2_btree_iter_set_pos(iter, pos);
2036 return ret;
2037 }
2038
2039 static noinline
bch2_btree_trans_peek_prev_updates(struct btree_trans * trans,struct btree_iter * iter,struct bkey_s_c * k)2040 void bch2_btree_trans_peek_prev_updates(struct btree_trans *trans, struct btree_iter *iter,
2041 struct bkey_s_c *k)
2042 {
2043 struct bpos end = path_l(btree_iter_path(trans, iter))->b->data->min_key;
2044
2045 trans_for_each_update(trans, i)
2046 if (!i->key_cache_already_flushed &&
2047 i->btree_id == iter->btree_id &&
2048 bpos_le(i->k->k.p, iter->pos) &&
2049 bpos_ge(i->k->k.p, k->k ? k->k->p : end)) {
2050 iter->k = i->k->k;
2051 *k = bkey_i_to_s_c(i->k);
2052 }
2053 }
2054
2055 static noinline
bch2_btree_trans_peek_updates(struct btree_trans * trans,struct btree_iter * iter,struct bkey_s_c * k)2056 void bch2_btree_trans_peek_updates(struct btree_trans *trans, struct btree_iter *iter,
2057 struct bkey_s_c *k)
2058 {
2059 struct btree_path *path = btree_iter_path(trans, iter);
2060 struct bpos end = path_l(path)->b->key.k.p;
2061
2062 trans_for_each_update(trans, i)
2063 if (!i->key_cache_already_flushed &&
2064 i->btree_id == iter->btree_id &&
2065 bpos_ge(i->k->k.p, path->pos) &&
2066 bpos_le(i->k->k.p, k->k ? k->k->p : end)) {
2067 iter->k = i->k->k;
2068 *k = bkey_i_to_s_c(i->k);
2069 }
2070 }
2071
2072 static noinline
bch2_btree_trans_peek_slot_updates(struct btree_trans * trans,struct btree_iter * iter,struct bkey_s_c * k)2073 void bch2_btree_trans_peek_slot_updates(struct btree_trans *trans, struct btree_iter *iter,
2074 struct bkey_s_c *k)
2075 {
2076 trans_for_each_update(trans, i)
2077 if (!i->key_cache_already_flushed &&
2078 i->btree_id == iter->btree_id &&
2079 bpos_eq(i->k->k.p, iter->pos)) {
2080 iter->k = i->k->k;
2081 *k = bkey_i_to_s_c(i->k);
2082 }
2083 }
2084
bch2_btree_journal_peek(struct btree_trans * trans,struct btree_iter * iter,struct bpos end_pos)2085 static struct bkey_i *bch2_btree_journal_peek(struct btree_trans *trans,
2086 struct btree_iter *iter,
2087 struct bpos end_pos)
2088 {
2089 struct btree_path *path = btree_iter_path(trans, iter);
2090
2091 return bch2_journal_keys_peek_upto(trans->c, iter->btree_id,
2092 path->level,
2093 path->pos,
2094 end_pos,
2095 &iter->journal_idx);
2096 }
2097
2098 static noinline
btree_trans_peek_slot_journal(struct btree_trans * trans,struct btree_iter * iter)2099 struct bkey_s_c btree_trans_peek_slot_journal(struct btree_trans *trans,
2100 struct btree_iter *iter)
2101 {
2102 struct btree_path *path = btree_iter_path(trans, iter);
2103 struct bkey_i *k = bch2_btree_journal_peek(trans, iter, path->pos);
2104
2105 if (k) {
2106 iter->k = k->k;
2107 return bkey_i_to_s_c(k);
2108 } else {
2109 return bkey_s_c_null;
2110 }
2111 }
2112
2113 static noinline
btree_trans_peek_journal(struct btree_trans * trans,struct btree_iter * iter,struct bkey_s_c k)2114 struct bkey_s_c btree_trans_peek_journal(struct btree_trans *trans,
2115 struct btree_iter *iter,
2116 struct bkey_s_c k)
2117 {
2118 struct btree_path *path = btree_iter_path(trans, iter);
2119 struct bkey_i *next_journal =
2120 bch2_btree_journal_peek(trans, iter,
2121 k.k ? k.k->p : path_l(path)->b->key.k.p);
2122
2123 if (next_journal) {
2124 iter->k = next_journal->k;
2125 k = bkey_i_to_s_c(next_journal);
2126 }
2127
2128 return k;
2129 }
2130
2131 /*
2132 * Checks btree key cache for key at iter->pos and returns it if present, or
2133 * bkey_s_c_null:
2134 */
2135 static noinline
btree_trans_peek_key_cache(struct btree_iter * iter,struct bpos pos)2136 struct bkey_s_c btree_trans_peek_key_cache(struct btree_iter *iter, struct bpos pos)
2137 {
2138 struct btree_trans *trans = iter->trans;
2139 struct bch_fs *c = trans->c;
2140 struct bkey u;
2141 struct bkey_s_c k;
2142 int ret;
2143
2144 bch2_trans_verify_not_in_restart(trans);
2145 bch2_trans_verify_not_unlocked(trans);
2146
2147 if ((iter->flags & BTREE_ITER_key_cache_fill) &&
2148 bpos_eq(iter->pos, pos))
2149 return bkey_s_c_null;
2150
2151 if (!bch2_btree_key_cache_find(c, iter->btree_id, pos))
2152 return bkey_s_c_null;
2153
2154 if (!iter->key_cache_path)
2155 iter->key_cache_path = bch2_path_get(trans, iter->btree_id, pos,
2156 iter->flags & BTREE_ITER_intent, 0,
2157 iter->flags|BTREE_ITER_cached|
2158 BTREE_ITER_cached_nofill,
2159 _THIS_IP_);
2160
2161 iter->key_cache_path = bch2_btree_path_set_pos(trans, iter->key_cache_path, pos,
2162 iter->flags & BTREE_ITER_intent,
2163 btree_iter_ip_allocated(iter));
2164
2165 ret = bch2_btree_path_traverse(trans, iter->key_cache_path,
2166 iter->flags|BTREE_ITER_cached) ?:
2167 bch2_btree_path_relock(trans, btree_iter_path(trans, iter), _THIS_IP_);
2168 if (unlikely(ret))
2169 return bkey_s_c_err(ret);
2170
2171 btree_path_set_should_be_locked(trans, trans->paths + iter->key_cache_path);
2172
2173 k = bch2_btree_path_peek_slot(trans->paths + iter->key_cache_path, &u);
2174 if (k.k && !bkey_err(k)) {
2175 iter->k = u;
2176 k.k = &iter->k;
2177 }
2178 return k;
2179 }
2180
__bch2_btree_iter_peek(struct btree_iter * iter,struct bpos search_key)2181 static struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter, struct bpos search_key)
2182 {
2183 struct btree_trans *trans = iter->trans;
2184 struct bkey_s_c k, k2;
2185 int ret;
2186
2187 EBUG_ON(btree_iter_path(trans, iter)->cached);
2188 bch2_btree_iter_verify(iter);
2189
2190 while (1) {
2191 struct btree_path_level *l;
2192
2193 iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key,
2194 iter->flags & BTREE_ITER_intent,
2195 btree_iter_ip_allocated(iter));
2196
2197 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
2198 if (unlikely(ret)) {
2199 /* ensure that iter->k is consistent with iter->pos: */
2200 bch2_btree_iter_set_pos(iter, iter->pos);
2201 k = bkey_s_c_err(ret);
2202 goto out;
2203 }
2204
2205 struct btree_path *path = btree_iter_path(trans, iter);
2206 l = path_l(path);
2207
2208 if (unlikely(!l->b)) {
2209 /* No btree nodes at requested level: */
2210 bch2_btree_iter_set_pos(iter, SPOS_MAX);
2211 k = bkey_s_c_null;
2212 goto out;
2213 }
2214
2215 btree_path_set_should_be_locked(trans, path);
2216
2217 k = btree_path_level_peek_all(trans->c, l, &iter->k);
2218
2219 if (unlikely(iter->flags & BTREE_ITER_with_key_cache) &&
2220 k.k &&
2221 (k2 = btree_trans_peek_key_cache(iter, k.k->p)).k) {
2222 k = k2;
2223 ret = bkey_err(k);
2224 if (ret) {
2225 bch2_btree_iter_set_pos(iter, iter->pos);
2226 goto out;
2227 }
2228 }
2229
2230 if (unlikely(iter->flags & BTREE_ITER_with_journal))
2231 k = btree_trans_peek_journal(trans, iter, k);
2232
2233 if (unlikely((iter->flags & BTREE_ITER_with_updates) &&
2234 trans->nr_updates))
2235 bch2_btree_trans_peek_updates(trans, iter, &k);
2236
2237 if (k.k && bkey_deleted(k.k)) {
2238 /*
2239 * If we've got a whiteout, and it's after the search
2240 * key, advance the search key to the whiteout instead
2241 * of just after the whiteout - it might be a btree
2242 * whiteout, with a real key at the same position, since
2243 * in the btree deleted keys sort before non deleted.
2244 */
2245 search_key = !bpos_eq(search_key, k.k->p)
2246 ? k.k->p
2247 : bpos_successor(k.k->p);
2248 continue;
2249 }
2250
2251 if (likely(k.k)) {
2252 break;
2253 } else if (likely(!bpos_eq(l->b->key.k.p, SPOS_MAX))) {
2254 /* Advance to next leaf node: */
2255 search_key = bpos_successor(l->b->key.k.p);
2256 } else {
2257 /* End of btree: */
2258 bch2_btree_iter_set_pos(iter, SPOS_MAX);
2259 k = bkey_s_c_null;
2260 goto out;
2261 }
2262 }
2263 out:
2264 bch2_btree_iter_verify(iter);
2265
2266 return k;
2267 }
2268
2269 /**
2270 * bch2_btree_iter_peek_upto() - returns first key greater than or equal to
2271 * iterator's current position
2272 * @iter: iterator to peek from
2273 * @end: search limit: returns keys less than or equal to @end
2274 *
2275 * Returns: key if found, or an error extractable with bkey_err().
2276 */
bch2_btree_iter_peek_upto(struct btree_iter * iter,struct bpos end)2277 struct bkey_s_c bch2_btree_iter_peek_upto(struct btree_iter *iter, struct bpos end)
2278 {
2279 struct btree_trans *trans = iter->trans;
2280 struct bpos search_key = btree_iter_search_key(iter);
2281 struct bkey_s_c k;
2282 struct bpos iter_pos;
2283 int ret;
2284
2285 bch2_trans_verify_not_unlocked(trans);
2286 EBUG_ON((iter->flags & BTREE_ITER_filter_snapshots) && bkey_eq(end, POS_MAX));
2287
2288 if (iter->update_path) {
2289 bch2_path_put_nokeep(trans, iter->update_path,
2290 iter->flags & BTREE_ITER_intent);
2291 iter->update_path = 0;
2292 }
2293
2294 bch2_btree_iter_verify_entry_exit(iter);
2295
2296 while (1) {
2297 k = __bch2_btree_iter_peek(iter, search_key);
2298 if (unlikely(!k.k))
2299 goto end;
2300 if (unlikely(bkey_err(k)))
2301 goto out_no_locked;
2302
2303 /*
2304 * We need to check against @end before FILTER_SNAPSHOTS because
2305 * if we get to a different inode that requested we might be
2306 * seeing keys for a different snapshot tree that will all be
2307 * filtered out.
2308 *
2309 * But we can't do the full check here, because bkey_start_pos()
2310 * isn't monotonically increasing before FILTER_SNAPSHOTS, and
2311 * that's what we check against in extents mode:
2312 */
2313 if (unlikely(!(iter->flags & BTREE_ITER_is_extents)
2314 ? bkey_gt(k.k->p, end)
2315 : k.k->p.inode > end.inode))
2316 goto end;
2317
2318 if (iter->update_path &&
2319 !bkey_eq(trans->paths[iter->update_path].pos, k.k->p)) {
2320 bch2_path_put_nokeep(trans, iter->update_path,
2321 iter->flags & BTREE_ITER_intent);
2322 iter->update_path = 0;
2323 }
2324
2325 if ((iter->flags & BTREE_ITER_filter_snapshots) &&
2326 (iter->flags & BTREE_ITER_intent) &&
2327 !(iter->flags & BTREE_ITER_is_extents) &&
2328 !iter->update_path) {
2329 struct bpos pos = k.k->p;
2330
2331 if (pos.snapshot < iter->snapshot) {
2332 search_key = bpos_successor(k.k->p);
2333 continue;
2334 }
2335
2336 pos.snapshot = iter->snapshot;
2337
2338 /*
2339 * advance, same as on exit for iter->path, but only up
2340 * to snapshot
2341 */
2342 __btree_path_get(trans, trans->paths + iter->path, iter->flags & BTREE_ITER_intent);
2343 iter->update_path = iter->path;
2344
2345 iter->update_path = bch2_btree_path_set_pos(trans,
2346 iter->update_path, pos,
2347 iter->flags & BTREE_ITER_intent,
2348 _THIS_IP_);
2349 ret = bch2_btree_path_traverse(trans, iter->update_path, iter->flags);
2350 if (unlikely(ret)) {
2351 k = bkey_s_c_err(ret);
2352 goto out_no_locked;
2353 }
2354 }
2355
2356 /*
2357 * We can never have a key in a leaf node at POS_MAX, so
2358 * we don't have to check these successor() calls:
2359 */
2360 if ((iter->flags & BTREE_ITER_filter_snapshots) &&
2361 !bch2_snapshot_is_ancestor(trans->c,
2362 iter->snapshot,
2363 k.k->p.snapshot)) {
2364 search_key = bpos_successor(k.k->p);
2365 continue;
2366 }
2367
2368 if (bkey_whiteout(k.k) &&
2369 !(iter->flags & BTREE_ITER_all_snapshots)) {
2370 search_key = bkey_successor(iter, k.k->p);
2371 continue;
2372 }
2373
2374 /*
2375 * iter->pos should be mononotically increasing, and always be
2376 * equal to the key we just returned - except extents can
2377 * straddle iter->pos:
2378 */
2379 if (!(iter->flags & BTREE_ITER_is_extents))
2380 iter_pos = k.k->p;
2381 else
2382 iter_pos = bkey_max(iter->pos, bkey_start_pos(k.k));
2383
2384 if (unlikely(!(iter->flags & BTREE_ITER_is_extents)
2385 ? bkey_gt(iter_pos, end)
2386 : bkey_ge(iter_pos, end)))
2387 goto end;
2388
2389 break;
2390 }
2391
2392 iter->pos = iter_pos;
2393
2394 iter->path = bch2_btree_path_set_pos(trans, iter->path, k.k->p,
2395 iter->flags & BTREE_ITER_intent,
2396 btree_iter_ip_allocated(iter));
2397
2398 btree_path_set_should_be_locked(trans, btree_iter_path(trans, iter));
2399 out_no_locked:
2400 if (iter->update_path) {
2401 ret = bch2_btree_path_relock(trans, trans->paths + iter->update_path, _THIS_IP_);
2402 if (unlikely(ret))
2403 k = bkey_s_c_err(ret);
2404 else
2405 btree_path_set_should_be_locked(trans, trans->paths + iter->update_path);
2406 }
2407
2408 if (!(iter->flags & BTREE_ITER_all_snapshots))
2409 iter->pos.snapshot = iter->snapshot;
2410
2411 ret = bch2_btree_iter_verify_ret(iter, k);
2412 if (unlikely(ret)) {
2413 bch2_btree_iter_set_pos(iter, iter->pos);
2414 k = bkey_s_c_err(ret);
2415 }
2416
2417 bch2_btree_iter_verify_entry_exit(iter);
2418
2419 return k;
2420 end:
2421 bch2_btree_iter_set_pos(iter, end);
2422 k = bkey_s_c_null;
2423 goto out_no_locked;
2424 }
2425
2426 /**
2427 * bch2_btree_iter_next() - returns first key greater than iterator's current
2428 * position
2429 * @iter: iterator to peek from
2430 *
2431 * Returns: key if found, or an error extractable with bkey_err().
2432 */
bch2_btree_iter_next(struct btree_iter * iter)2433 struct bkey_s_c bch2_btree_iter_next(struct btree_iter *iter)
2434 {
2435 if (!bch2_btree_iter_advance(iter))
2436 return bkey_s_c_null;
2437
2438 return bch2_btree_iter_peek(iter);
2439 }
2440
2441 /**
2442 * bch2_btree_iter_peek_prev() - returns first key less than or equal to
2443 * iterator's current position
2444 * @iter: iterator to peek from
2445 *
2446 * Returns: key if found, or an error extractable with bkey_err().
2447 */
bch2_btree_iter_peek_prev(struct btree_iter * iter)2448 struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *iter)
2449 {
2450 struct btree_trans *trans = iter->trans;
2451 struct bpos search_key = iter->pos;
2452 struct bkey_s_c k;
2453 struct bkey saved_k;
2454 const struct bch_val *saved_v;
2455 btree_path_idx_t saved_path = 0;
2456 int ret;
2457
2458 bch2_trans_verify_not_unlocked(trans);
2459 EBUG_ON(btree_iter_path(trans, iter)->cached ||
2460 btree_iter_path(trans, iter)->level);
2461
2462 if (iter->flags & BTREE_ITER_with_journal)
2463 return bkey_s_c_err(-BCH_ERR_btree_iter_with_journal_not_supported);
2464
2465 bch2_btree_iter_verify(iter);
2466 bch2_btree_iter_verify_entry_exit(iter);
2467
2468 if (iter->flags & BTREE_ITER_filter_snapshots)
2469 search_key.snapshot = U32_MAX;
2470
2471 while (1) {
2472 iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key,
2473 iter->flags & BTREE_ITER_intent,
2474 btree_iter_ip_allocated(iter));
2475
2476 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
2477 if (unlikely(ret)) {
2478 /* ensure that iter->k is consistent with iter->pos: */
2479 bch2_btree_iter_set_pos(iter, iter->pos);
2480 k = bkey_s_c_err(ret);
2481 goto out_no_locked;
2482 }
2483
2484 struct btree_path *path = btree_iter_path(trans, iter);
2485
2486 k = btree_path_level_peek(trans, path, &path->l[0], &iter->k);
2487 if (!k.k ||
2488 ((iter->flags & BTREE_ITER_is_extents)
2489 ? bpos_ge(bkey_start_pos(k.k), search_key)
2490 : bpos_gt(k.k->p, search_key)))
2491 k = btree_path_level_prev(trans, path, &path->l[0], &iter->k);
2492
2493 if (unlikely((iter->flags & BTREE_ITER_with_updates) &&
2494 trans->nr_updates))
2495 bch2_btree_trans_peek_prev_updates(trans, iter, &k);
2496
2497 if (likely(k.k)) {
2498 if (iter->flags & BTREE_ITER_filter_snapshots) {
2499 if (k.k->p.snapshot == iter->snapshot)
2500 goto got_key;
2501
2502 /*
2503 * If we have a saved candidate, and we're no
2504 * longer at the same _key_ (not pos), return
2505 * that candidate
2506 */
2507 if (saved_path && !bkey_eq(k.k->p, saved_k.p)) {
2508 bch2_path_put_nokeep(trans, iter->path,
2509 iter->flags & BTREE_ITER_intent);
2510 iter->path = saved_path;
2511 saved_path = 0;
2512 iter->k = saved_k;
2513 k.v = saved_v;
2514 goto got_key;
2515 }
2516
2517 if (bch2_snapshot_is_ancestor(trans->c,
2518 iter->snapshot,
2519 k.k->p.snapshot)) {
2520 if (saved_path)
2521 bch2_path_put_nokeep(trans, saved_path,
2522 iter->flags & BTREE_ITER_intent);
2523 saved_path = btree_path_clone(trans, iter->path,
2524 iter->flags & BTREE_ITER_intent,
2525 _THIS_IP_);
2526 path = btree_iter_path(trans, iter);
2527 trace_btree_path_save_pos(trans, path, trans->paths + saved_path);
2528 saved_k = *k.k;
2529 saved_v = k.v;
2530 }
2531
2532 search_key = bpos_predecessor(k.k->p);
2533 continue;
2534 }
2535 got_key:
2536 if (bkey_whiteout(k.k) &&
2537 !(iter->flags & BTREE_ITER_all_snapshots)) {
2538 search_key = bkey_predecessor(iter, k.k->p);
2539 if (iter->flags & BTREE_ITER_filter_snapshots)
2540 search_key.snapshot = U32_MAX;
2541 continue;
2542 }
2543
2544 btree_path_set_should_be_locked(trans, path);
2545 break;
2546 } else if (likely(!bpos_eq(path->l[0].b->data->min_key, POS_MIN))) {
2547 /* Advance to previous leaf node: */
2548 search_key = bpos_predecessor(path->l[0].b->data->min_key);
2549 } else {
2550 /* Start of btree: */
2551 bch2_btree_iter_set_pos(iter, POS_MIN);
2552 k = bkey_s_c_null;
2553 goto out_no_locked;
2554 }
2555 }
2556
2557 EBUG_ON(bkey_gt(bkey_start_pos(k.k), iter->pos));
2558
2559 /* Extents can straddle iter->pos: */
2560 if (bkey_lt(k.k->p, iter->pos))
2561 iter->pos = k.k->p;
2562
2563 if (iter->flags & BTREE_ITER_filter_snapshots)
2564 iter->pos.snapshot = iter->snapshot;
2565 out_no_locked:
2566 if (saved_path)
2567 bch2_path_put_nokeep(trans, saved_path, iter->flags & BTREE_ITER_intent);
2568
2569 bch2_btree_iter_verify_entry_exit(iter);
2570 bch2_btree_iter_verify(iter);
2571
2572 return k;
2573 }
2574
2575 /**
2576 * bch2_btree_iter_prev() - returns first key less than iterator's current
2577 * position
2578 * @iter: iterator to peek from
2579 *
2580 * Returns: key if found, or an error extractable with bkey_err().
2581 */
bch2_btree_iter_prev(struct btree_iter * iter)2582 struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *iter)
2583 {
2584 if (!bch2_btree_iter_rewind(iter))
2585 return bkey_s_c_null;
2586
2587 return bch2_btree_iter_peek_prev(iter);
2588 }
2589
bch2_btree_iter_peek_slot(struct btree_iter * iter)2590 struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *iter)
2591 {
2592 struct btree_trans *trans = iter->trans;
2593 struct bpos search_key;
2594 struct bkey_s_c k;
2595 int ret;
2596
2597 bch2_trans_verify_not_unlocked(trans);
2598 bch2_btree_iter_verify(iter);
2599 bch2_btree_iter_verify_entry_exit(iter);
2600 EBUG_ON(btree_iter_path(trans, iter)->level && (iter->flags & BTREE_ITER_with_key_cache));
2601
2602 /* extents can't span inode numbers: */
2603 if ((iter->flags & BTREE_ITER_is_extents) &&
2604 unlikely(iter->pos.offset == KEY_OFFSET_MAX)) {
2605 if (iter->pos.inode == KEY_INODE_MAX)
2606 return bkey_s_c_null;
2607
2608 bch2_btree_iter_set_pos(iter, bpos_nosnap_successor(iter->pos));
2609 }
2610
2611 search_key = btree_iter_search_key(iter);
2612 iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key,
2613 iter->flags & BTREE_ITER_intent,
2614 btree_iter_ip_allocated(iter));
2615
2616 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
2617 if (unlikely(ret)) {
2618 k = bkey_s_c_err(ret);
2619 goto out_no_locked;
2620 }
2621
2622 if ((iter->flags & BTREE_ITER_cached) ||
2623 !(iter->flags & (BTREE_ITER_is_extents|BTREE_ITER_filter_snapshots))) {
2624 k = bkey_s_c_null;
2625
2626 if (unlikely((iter->flags & BTREE_ITER_with_updates) &&
2627 trans->nr_updates)) {
2628 bch2_btree_trans_peek_slot_updates(trans, iter, &k);
2629 if (k.k)
2630 goto out;
2631 }
2632
2633 if (unlikely(iter->flags & BTREE_ITER_with_journal) &&
2634 (k = btree_trans_peek_slot_journal(trans, iter)).k)
2635 goto out;
2636
2637 if (unlikely(iter->flags & BTREE_ITER_with_key_cache) &&
2638 (k = btree_trans_peek_key_cache(iter, iter->pos)).k) {
2639 if (!bkey_err(k))
2640 iter->k = *k.k;
2641 /* We're not returning a key from iter->path: */
2642 goto out_no_locked;
2643 }
2644
2645 k = bch2_btree_path_peek_slot(trans->paths + iter->path, &iter->k);
2646 if (unlikely(!k.k))
2647 goto out_no_locked;
2648 } else {
2649 struct bpos next;
2650 struct bpos end = iter->pos;
2651
2652 if (iter->flags & BTREE_ITER_is_extents)
2653 end.offset = U64_MAX;
2654
2655 EBUG_ON(btree_iter_path(trans, iter)->level);
2656
2657 if (iter->flags & BTREE_ITER_intent) {
2658 struct btree_iter iter2;
2659
2660 bch2_trans_copy_iter(&iter2, iter);
2661 k = bch2_btree_iter_peek_upto(&iter2, end);
2662
2663 if (k.k && !bkey_err(k)) {
2664 swap(iter->key_cache_path, iter2.key_cache_path);
2665 iter->k = iter2.k;
2666 k.k = &iter->k;
2667 }
2668 bch2_trans_iter_exit(trans, &iter2);
2669 } else {
2670 struct bpos pos = iter->pos;
2671
2672 k = bch2_btree_iter_peek_upto(iter, end);
2673 if (unlikely(bkey_err(k)))
2674 bch2_btree_iter_set_pos(iter, pos);
2675 else
2676 iter->pos = pos;
2677 }
2678
2679 if (unlikely(bkey_err(k)))
2680 goto out_no_locked;
2681
2682 next = k.k ? bkey_start_pos(k.k) : POS_MAX;
2683
2684 if (bkey_lt(iter->pos, next)) {
2685 bkey_init(&iter->k);
2686 iter->k.p = iter->pos;
2687
2688 if (iter->flags & BTREE_ITER_is_extents) {
2689 bch2_key_resize(&iter->k,
2690 min_t(u64, KEY_SIZE_MAX,
2691 (next.inode == iter->pos.inode
2692 ? next.offset
2693 : KEY_OFFSET_MAX) -
2694 iter->pos.offset));
2695 EBUG_ON(!iter->k.size);
2696 }
2697
2698 k = (struct bkey_s_c) { &iter->k, NULL };
2699 }
2700 }
2701 out:
2702 btree_path_set_should_be_locked(trans, btree_iter_path(trans, iter));
2703 out_no_locked:
2704 bch2_btree_iter_verify_entry_exit(iter);
2705 bch2_btree_iter_verify(iter);
2706 ret = bch2_btree_iter_verify_ret(iter, k);
2707 if (unlikely(ret))
2708 return bkey_s_c_err(ret);
2709
2710 return k;
2711 }
2712
bch2_btree_iter_next_slot(struct btree_iter * iter)2713 struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *iter)
2714 {
2715 if (!bch2_btree_iter_advance(iter))
2716 return bkey_s_c_null;
2717
2718 return bch2_btree_iter_peek_slot(iter);
2719 }
2720
bch2_btree_iter_prev_slot(struct btree_iter * iter)2721 struct bkey_s_c bch2_btree_iter_prev_slot(struct btree_iter *iter)
2722 {
2723 if (!bch2_btree_iter_rewind(iter))
2724 return bkey_s_c_null;
2725
2726 return bch2_btree_iter_peek_slot(iter);
2727 }
2728
2729 /* Obsolete, but still used by rust wrapper in -tools */
bch2_btree_iter_peek_and_restart_outlined(struct btree_iter * iter)2730 struct bkey_s_c bch2_btree_iter_peek_and_restart_outlined(struct btree_iter *iter)
2731 {
2732 struct bkey_s_c k;
2733
2734 while (btree_trans_too_many_iters(iter->trans) ||
2735 (k = bch2_btree_iter_peek_type(iter, iter->flags),
2736 bch2_err_matches(bkey_err(k), BCH_ERR_transaction_restart)))
2737 bch2_trans_begin(iter->trans);
2738
2739 return k;
2740 }
2741
2742 /* new transactional stuff: */
2743
2744 #ifdef CONFIG_BCACHEFS_DEBUG
btree_trans_verify_sorted_refs(struct btree_trans * trans)2745 static void btree_trans_verify_sorted_refs(struct btree_trans *trans)
2746 {
2747 struct btree_path *path;
2748 unsigned i;
2749
2750 BUG_ON(trans->nr_sorted != bitmap_weight(trans->paths_allocated, trans->nr_paths) - 1);
2751
2752 trans_for_each_path(trans, path, i) {
2753 BUG_ON(path->sorted_idx >= trans->nr_sorted);
2754 BUG_ON(trans->sorted[path->sorted_idx] != i);
2755 }
2756
2757 for (i = 0; i < trans->nr_sorted; i++) {
2758 unsigned idx = trans->sorted[i];
2759
2760 BUG_ON(!test_bit(idx, trans->paths_allocated));
2761 BUG_ON(trans->paths[idx].sorted_idx != i);
2762 }
2763 }
2764
btree_trans_verify_sorted(struct btree_trans * trans)2765 static void btree_trans_verify_sorted(struct btree_trans *trans)
2766 {
2767 struct btree_path *path, *prev = NULL;
2768 struct trans_for_each_path_inorder_iter iter;
2769
2770 if (!bch2_debug_check_iterators)
2771 return;
2772
2773 trans_for_each_path_inorder(trans, path, iter) {
2774 if (prev && btree_path_cmp(prev, path) > 0) {
2775 __bch2_dump_trans_paths_updates(trans, true);
2776 panic("trans paths out of order!\n");
2777 }
2778 prev = path;
2779 }
2780 }
2781 #else
btree_trans_verify_sorted_refs(struct btree_trans * trans)2782 static inline void btree_trans_verify_sorted_refs(struct btree_trans *trans) {}
btree_trans_verify_sorted(struct btree_trans * trans)2783 static inline void btree_trans_verify_sorted(struct btree_trans *trans) {}
2784 #endif
2785
__bch2_btree_trans_sort_paths(struct btree_trans * trans)2786 void __bch2_btree_trans_sort_paths(struct btree_trans *trans)
2787 {
2788 int i, l = 0, r = trans->nr_sorted, inc = 1;
2789 bool swapped;
2790
2791 btree_trans_verify_sorted_refs(trans);
2792
2793 if (trans->paths_sorted)
2794 goto out;
2795
2796 /*
2797 * Cocktail shaker sort: this is efficient because iterators will be
2798 * mostly sorted.
2799 */
2800 do {
2801 swapped = false;
2802
2803 for (i = inc > 0 ? l : r - 2;
2804 i + 1 < r && i >= l;
2805 i += inc) {
2806 if (btree_path_cmp(trans->paths + trans->sorted[i],
2807 trans->paths + trans->sorted[i + 1]) > 0) {
2808 swap(trans->sorted[i], trans->sorted[i + 1]);
2809 trans->paths[trans->sorted[i]].sorted_idx = i;
2810 trans->paths[trans->sorted[i + 1]].sorted_idx = i + 1;
2811 swapped = true;
2812 }
2813 }
2814
2815 if (inc > 0)
2816 --r;
2817 else
2818 l++;
2819 inc = -inc;
2820 } while (swapped);
2821
2822 trans->paths_sorted = true;
2823 out:
2824 btree_trans_verify_sorted(trans);
2825 }
2826
btree_path_list_remove(struct btree_trans * trans,struct btree_path * path)2827 static inline void btree_path_list_remove(struct btree_trans *trans,
2828 struct btree_path *path)
2829 {
2830 EBUG_ON(path->sorted_idx >= trans->nr_sorted);
2831 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
2832 trans->nr_sorted--;
2833 memmove_u64s_down_small(trans->sorted + path->sorted_idx,
2834 trans->sorted + path->sorted_idx + 1,
2835 DIV_ROUND_UP(trans->nr_sorted - path->sorted_idx,
2836 sizeof(u64) / sizeof(btree_path_idx_t)));
2837 #else
2838 array_remove_item(trans->sorted, trans->nr_sorted, path->sorted_idx);
2839 #endif
2840 for (unsigned i = path->sorted_idx; i < trans->nr_sorted; i++)
2841 trans->paths[trans->sorted[i]].sorted_idx = i;
2842 }
2843
btree_path_list_add(struct btree_trans * trans,btree_path_idx_t pos,btree_path_idx_t path_idx)2844 static inline void btree_path_list_add(struct btree_trans *trans,
2845 btree_path_idx_t pos,
2846 btree_path_idx_t path_idx)
2847 {
2848 struct btree_path *path = trans->paths + path_idx;
2849
2850 path->sorted_idx = pos ? trans->paths[pos].sorted_idx + 1 : trans->nr_sorted;
2851
2852 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
2853 memmove_u64s_up_small(trans->sorted + path->sorted_idx + 1,
2854 trans->sorted + path->sorted_idx,
2855 DIV_ROUND_UP(trans->nr_sorted - path->sorted_idx,
2856 sizeof(u64) / sizeof(btree_path_idx_t)));
2857 trans->nr_sorted++;
2858 trans->sorted[path->sorted_idx] = path_idx;
2859 #else
2860 array_insert_item(trans->sorted, trans->nr_sorted, path->sorted_idx, path_idx);
2861 #endif
2862
2863 for (unsigned i = path->sorted_idx; i < trans->nr_sorted; i++)
2864 trans->paths[trans->sorted[i]].sorted_idx = i;
2865
2866 btree_trans_verify_sorted_refs(trans);
2867 }
2868
bch2_trans_iter_exit(struct btree_trans * trans,struct btree_iter * iter)2869 void bch2_trans_iter_exit(struct btree_trans *trans, struct btree_iter *iter)
2870 {
2871 if (iter->update_path)
2872 bch2_path_put_nokeep(trans, iter->update_path,
2873 iter->flags & BTREE_ITER_intent);
2874 if (iter->path)
2875 bch2_path_put(trans, iter->path,
2876 iter->flags & BTREE_ITER_intent);
2877 if (iter->key_cache_path)
2878 bch2_path_put(trans, iter->key_cache_path,
2879 iter->flags & BTREE_ITER_intent);
2880 iter->path = 0;
2881 iter->update_path = 0;
2882 iter->key_cache_path = 0;
2883 iter->trans = NULL;
2884 }
2885
bch2_trans_iter_init_outlined(struct btree_trans * trans,struct btree_iter * iter,enum btree_id btree_id,struct bpos pos,unsigned flags)2886 void bch2_trans_iter_init_outlined(struct btree_trans *trans,
2887 struct btree_iter *iter,
2888 enum btree_id btree_id, struct bpos pos,
2889 unsigned flags)
2890 {
2891 bch2_trans_iter_init_common(trans, iter, btree_id, pos, 0, 0,
2892 bch2_btree_iter_flags(trans, btree_id, flags),
2893 _RET_IP_);
2894 }
2895
bch2_trans_node_iter_init(struct btree_trans * trans,struct btree_iter * iter,enum btree_id btree_id,struct bpos pos,unsigned locks_want,unsigned depth,unsigned flags)2896 void bch2_trans_node_iter_init(struct btree_trans *trans,
2897 struct btree_iter *iter,
2898 enum btree_id btree_id,
2899 struct bpos pos,
2900 unsigned locks_want,
2901 unsigned depth,
2902 unsigned flags)
2903 {
2904 flags |= BTREE_ITER_not_extents;
2905 flags |= BTREE_ITER_snapshot_field;
2906 flags |= BTREE_ITER_all_snapshots;
2907
2908 bch2_trans_iter_init_common(trans, iter, btree_id, pos, locks_want, depth,
2909 __bch2_btree_iter_flags(trans, btree_id, flags),
2910 _RET_IP_);
2911
2912 iter->min_depth = depth;
2913
2914 struct btree_path *path = btree_iter_path(trans, iter);
2915 BUG_ON(path->locks_want < min(locks_want, BTREE_MAX_DEPTH));
2916 BUG_ON(path->level != depth);
2917 BUG_ON(iter->min_depth != depth);
2918 }
2919
bch2_trans_copy_iter(struct btree_iter * dst,struct btree_iter * src)2920 void bch2_trans_copy_iter(struct btree_iter *dst, struct btree_iter *src)
2921 {
2922 struct btree_trans *trans = src->trans;
2923
2924 *dst = *src;
2925 #ifdef TRACK_PATH_ALLOCATED
2926 dst->ip_allocated = _RET_IP_;
2927 #endif
2928 if (src->path)
2929 __btree_path_get(trans, trans->paths + src->path, src->flags & BTREE_ITER_intent);
2930 if (src->update_path)
2931 __btree_path_get(trans, trans->paths + src->update_path, src->flags & BTREE_ITER_intent);
2932 dst->key_cache_path = 0;
2933 }
2934
__bch2_trans_kmalloc(struct btree_trans * trans,size_t size)2935 void *__bch2_trans_kmalloc(struct btree_trans *trans, size_t size)
2936 {
2937 struct bch_fs *c = trans->c;
2938 unsigned new_top = trans->mem_top + size;
2939 unsigned old_bytes = trans->mem_bytes;
2940 unsigned new_bytes = roundup_pow_of_two(new_top);
2941 int ret;
2942 void *new_mem;
2943 void *p;
2944
2945 WARN_ON_ONCE(new_bytes > BTREE_TRANS_MEM_MAX);
2946
2947 struct btree_transaction_stats *s = btree_trans_stats(trans);
2948 s->max_mem = max(s->max_mem, new_bytes);
2949
2950 if (trans->used_mempool) {
2951 if (trans->mem_bytes >= new_bytes)
2952 goto out_change_top;
2953
2954 /* No more space from mempool item, need malloc new one */
2955 new_mem = kmalloc(new_bytes, GFP_NOWAIT|__GFP_NOWARN);
2956 if (unlikely(!new_mem)) {
2957 bch2_trans_unlock(trans);
2958
2959 new_mem = kmalloc(new_bytes, GFP_KERNEL);
2960 if (!new_mem)
2961 return ERR_PTR(-BCH_ERR_ENOMEM_trans_kmalloc);
2962
2963 ret = bch2_trans_relock(trans);
2964 if (ret) {
2965 kfree(new_mem);
2966 return ERR_PTR(ret);
2967 }
2968 }
2969 memcpy(new_mem, trans->mem, trans->mem_top);
2970 trans->used_mempool = false;
2971 mempool_free(trans->mem, &c->btree_trans_mem_pool);
2972 goto out_new_mem;
2973 }
2974
2975 new_mem = krealloc(trans->mem, new_bytes, GFP_NOWAIT|__GFP_NOWARN);
2976 if (unlikely(!new_mem)) {
2977 bch2_trans_unlock(trans);
2978
2979 new_mem = krealloc(trans->mem, new_bytes, GFP_KERNEL);
2980 if (!new_mem && new_bytes <= BTREE_TRANS_MEM_MAX) {
2981 new_mem = mempool_alloc(&c->btree_trans_mem_pool, GFP_KERNEL);
2982 new_bytes = BTREE_TRANS_MEM_MAX;
2983 memcpy(new_mem, trans->mem, trans->mem_top);
2984 trans->used_mempool = true;
2985 kfree(trans->mem);
2986 }
2987
2988 if (!new_mem)
2989 return ERR_PTR(-BCH_ERR_ENOMEM_trans_kmalloc);
2990
2991 trans->mem = new_mem;
2992 trans->mem_bytes = new_bytes;
2993
2994 ret = bch2_trans_relock(trans);
2995 if (ret)
2996 return ERR_PTR(ret);
2997 }
2998 out_new_mem:
2999 trans->mem = new_mem;
3000 trans->mem_bytes = new_bytes;
3001
3002 if (old_bytes) {
3003 trace_and_count(c, trans_restart_mem_realloced, trans, _RET_IP_, new_bytes);
3004 return ERR_PTR(btree_trans_restart(trans, BCH_ERR_transaction_restart_mem_realloced));
3005 }
3006 out_change_top:
3007 p = trans->mem + trans->mem_top;
3008 trans->mem_top += size;
3009 memset(p, 0, size);
3010 return p;
3011 }
3012
check_srcu_held_too_long(struct btree_trans * trans)3013 static inline void check_srcu_held_too_long(struct btree_trans *trans)
3014 {
3015 WARN(trans->srcu_held && time_after(jiffies, trans->srcu_lock_time + HZ * 10),
3016 "btree trans held srcu lock (delaying memory reclaim) for %lu seconds",
3017 (jiffies - trans->srcu_lock_time) / HZ);
3018 }
3019
bch2_trans_srcu_unlock(struct btree_trans * trans)3020 void bch2_trans_srcu_unlock(struct btree_trans *trans)
3021 {
3022 if (trans->srcu_held) {
3023 struct bch_fs *c = trans->c;
3024 struct btree_path *path;
3025 unsigned i;
3026
3027 trans_for_each_path(trans, path, i)
3028 if (path->cached && !btree_node_locked(path, 0))
3029 path->l[0].b = ERR_PTR(-BCH_ERR_no_btree_node_srcu_reset);
3030
3031 check_srcu_held_too_long(trans);
3032 srcu_read_unlock(&c->btree_trans_barrier, trans->srcu_idx);
3033 trans->srcu_held = false;
3034 }
3035 }
3036
bch2_trans_srcu_lock(struct btree_trans * trans)3037 static void bch2_trans_srcu_lock(struct btree_trans *trans)
3038 {
3039 if (!trans->srcu_held) {
3040 trans->srcu_idx = srcu_read_lock(&trans->c->btree_trans_barrier);
3041 trans->srcu_lock_time = jiffies;
3042 trans->srcu_held = true;
3043 }
3044 }
3045
3046 /**
3047 * bch2_trans_begin() - reset a transaction after a interrupted attempt
3048 * @trans: transaction to reset
3049 *
3050 * Returns: current restart counter, to be used with trans_was_restarted()
3051 *
3052 * While iterating over nodes or updating nodes a attempt to lock a btree node
3053 * may return BCH_ERR_transaction_restart when the trylock fails. When this
3054 * occurs bch2_trans_begin() should be called and the transaction retried.
3055 */
bch2_trans_begin(struct btree_trans * trans)3056 u32 bch2_trans_begin(struct btree_trans *trans)
3057 {
3058 struct btree_path *path;
3059 unsigned i;
3060 u64 now;
3061
3062 bch2_trans_reset_updates(trans);
3063
3064 trans->restart_count++;
3065 trans->mem_top = 0;
3066 trans->journal_entries = NULL;
3067
3068 trans_for_each_path(trans, path, i) {
3069 path->should_be_locked = false;
3070
3071 /*
3072 * If the transaction wasn't restarted, we're presuming to be
3073 * doing something new: dont keep iterators excpt the ones that
3074 * are in use - except for the subvolumes btree:
3075 */
3076 if (!trans->restarted && path->btree_id != BTREE_ID_subvolumes)
3077 path->preserve = false;
3078
3079 /*
3080 * XXX: we probably shouldn't be doing this if the transaction
3081 * was restarted, but currently we still overflow transaction
3082 * iterators if we do that
3083 */
3084 if (!path->ref && !path->preserve)
3085 __bch2_path_free(trans, i);
3086 else
3087 path->preserve = false;
3088 }
3089
3090 now = local_clock();
3091
3092 if (!IS_ENABLED(CONFIG_BCACHEFS_NO_LATENCY_ACCT) &&
3093 time_after64(now, trans->last_begin_time + 10))
3094 __bch2_time_stats_update(&btree_trans_stats(trans)->duration,
3095 trans->last_begin_time, now);
3096
3097 if (!trans->restarted &&
3098 (need_resched() ||
3099 time_after64(now, trans->last_begin_time + BTREE_TRANS_MAX_LOCK_HOLD_TIME_NS))) {
3100 bch2_trans_unlock(trans);
3101 cond_resched();
3102 now = local_clock();
3103 }
3104 trans->last_begin_time = now;
3105
3106 if (unlikely(trans->srcu_held &&
3107 time_after(jiffies, trans->srcu_lock_time + msecs_to_jiffies(10))))
3108 bch2_trans_srcu_unlock(trans);
3109
3110 trans->last_begin_ip = _RET_IP_;
3111
3112 trans_set_locked(trans);
3113
3114 if (trans->restarted) {
3115 bch2_btree_path_traverse_all(trans);
3116 trans->notrace_relock_fail = false;
3117 }
3118
3119 bch2_trans_verify_not_unlocked(trans);
3120 return trans->restart_count;
3121 }
3122
3123 const char *bch2_btree_transaction_fns[BCH_TRANSACTIONS_NR] = { "(unknown)" };
3124
bch2_trans_get_fn_idx(const char * fn)3125 unsigned bch2_trans_get_fn_idx(const char *fn)
3126 {
3127 for (unsigned i = 0; i < ARRAY_SIZE(bch2_btree_transaction_fns); i++)
3128 if (!bch2_btree_transaction_fns[i] ||
3129 bch2_btree_transaction_fns[i] == fn) {
3130 bch2_btree_transaction_fns[i] = fn;
3131 return i;
3132 }
3133
3134 pr_warn_once("BCH_TRANSACTIONS_NR not big enough!");
3135 return 0;
3136 }
3137
__bch2_trans_get(struct bch_fs * c,unsigned fn_idx)3138 struct btree_trans *__bch2_trans_get(struct bch_fs *c, unsigned fn_idx)
3139 __acquires(&c->btree_trans_barrier)
3140 {
3141 struct btree_trans *trans;
3142
3143 if (IS_ENABLED(__KERNEL__)) {
3144 trans = this_cpu_xchg(c->btree_trans_bufs->trans, NULL);
3145 if (trans) {
3146 memset(trans, 0, offsetof(struct btree_trans, list));
3147 goto got_trans;
3148 }
3149 }
3150
3151 trans = mempool_alloc(&c->btree_trans_pool, GFP_NOFS);
3152 memset(trans, 0, sizeof(*trans));
3153
3154 seqmutex_lock(&c->btree_trans_lock);
3155 if (IS_ENABLED(CONFIG_BCACHEFS_DEBUG)) {
3156 struct btree_trans *pos;
3157 pid_t pid = current->pid;
3158
3159 trans->locking_wait.task = current;
3160
3161 list_for_each_entry(pos, &c->btree_trans_list, list) {
3162 struct task_struct *pos_task = READ_ONCE(pos->locking_wait.task);
3163 /*
3164 * We'd much prefer to be stricter here and completely
3165 * disallow multiple btree_trans in the same thread -
3166 * but the data move path calls bch2_write when we
3167 * already have a btree_trans initialized.
3168 */
3169 BUG_ON(pos_task &&
3170 pid == pos_task->pid &&
3171 pos->locked);
3172 }
3173 }
3174
3175 list_add(&trans->list, &c->btree_trans_list);
3176 seqmutex_unlock(&c->btree_trans_lock);
3177 got_trans:
3178 trans->c = c;
3179 trans->last_begin_time = local_clock();
3180 trans->fn_idx = fn_idx;
3181 trans->locking_wait.task = current;
3182 trans->journal_replay_not_finished =
3183 unlikely(!test_bit(JOURNAL_replay_done, &c->journal.flags)) &&
3184 atomic_inc_not_zero(&c->journal_keys.ref);
3185 trans->nr_paths = ARRAY_SIZE(trans->_paths);
3186 trans->paths_allocated = trans->_paths_allocated;
3187 trans->sorted = trans->_sorted;
3188 trans->paths = trans->_paths;
3189 trans->updates = trans->_updates;
3190
3191 *trans_paths_nr(trans->paths) = BTREE_ITER_INITIAL;
3192
3193 trans->paths_allocated[0] = 1;
3194
3195 static struct lock_class_key lockdep_key;
3196 lockdep_init_map(&trans->dep_map, "bcachefs_btree", &lockdep_key, 0);
3197
3198 if (fn_idx < BCH_TRANSACTIONS_NR) {
3199 trans->fn = bch2_btree_transaction_fns[fn_idx];
3200
3201 struct btree_transaction_stats *s = &c->btree_transaction_stats[fn_idx];
3202
3203 if (s->max_mem) {
3204 unsigned expected_mem_bytes = roundup_pow_of_two(s->max_mem);
3205
3206 trans->mem = kmalloc(expected_mem_bytes, GFP_KERNEL);
3207 if (likely(trans->mem))
3208 trans->mem_bytes = expected_mem_bytes;
3209 }
3210
3211 trans->nr_paths_max = s->nr_max_paths;
3212 trans->journal_entries_size = s->journal_entries_size;
3213 }
3214
3215 trans->srcu_idx = srcu_read_lock(&c->btree_trans_barrier);
3216 trans->srcu_lock_time = jiffies;
3217 trans->srcu_held = true;
3218 trans_set_locked(trans);
3219
3220 closure_init_stack_release(&trans->ref);
3221 return trans;
3222 }
3223
check_btree_paths_leaked(struct btree_trans * trans)3224 static void check_btree_paths_leaked(struct btree_trans *trans)
3225 {
3226 #ifdef CONFIG_BCACHEFS_DEBUG
3227 struct bch_fs *c = trans->c;
3228 struct btree_path *path;
3229 unsigned i;
3230
3231 trans_for_each_path(trans, path, i)
3232 if (path->ref)
3233 goto leaked;
3234 return;
3235 leaked:
3236 bch_err(c, "btree paths leaked from %s!", trans->fn);
3237 trans_for_each_path(trans, path, i)
3238 if (path->ref)
3239 printk(KERN_ERR " btree %s %pS\n",
3240 bch2_btree_id_str(path->btree_id),
3241 (void *) path->ip_allocated);
3242 /* Be noisy about this: */
3243 bch2_fatal_error(c);
3244 #endif
3245 }
3246
bch2_trans_put(struct btree_trans * trans)3247 void bch2_trans_put(struct btree_trans *trans)
3248 __releases(&c->btree_trans_barrier)
3249 {
3250 struct bch_fs *c = trans->c;
3251
3252 bch2_trans_unlock(trans);
3253
3254 trans_for_each_update(trans, i)
3255 __btree_path_put(trans, trans->paths + i->path, true);
3256 trans->nr_updates = 0;
3257
3258 check_btree_paths_leaked(trans);
3259
3260 if (trans->srcu_held) {
3261 check_srcu_held_too_long(trans);
3262 srcu_read_unlock(&c->btree_trans_barrier, trans->srcu_idx);
3263 }
3264
3265 if (unlikely(trans->journal_replay_not_finished))
3266 bch2_journal_keys_put(c);
3267
3268 /*
3269 * trans->ref protects trans->locking_wait.task, btree_paths array; used
3270 * by cycle detector
3271 */
3272 closure_return_sync(&trans->ref);
3273 trans->locking_wait.task = NULL;
3274
3275 unsigned long *paths_allocated = trans->paths_allocated;
3276 trans->paths_allocated = NULL;
3277 trans->paths = NULL;
3278
3279 if (paths_allocated != trans->_paths_allocated)
3280 kvfree_rcu_mightsleep(paths_allocated);
3281
3282 if (trans->used_mempool)
3283 mempool_free(trans->mem, &c->btree_trans_mem_pool);
3284 else
3285 kfree(trans->mem);
3286
3287 /* Userspace doesn't have a real percpu implementation: */
3288 if (IS_ENABLED(__KERNEL__))
3289 trans = this_cpu_xchg(c->btree_trans_bufs->trans, trans);
3290
3291 if (trans) {
3292 seqmutex_lock(&c->btree_trans_lock);
3293 list_del(&trans->list);
3294 seqmutex_unlock(&c->btree_trans_lock);
3295
3296 mempool_free(trans, &c->btree_trans_pool);
3297 }
3298 }
3299
bch2_current_has_btree_trans(struct bch_fs * c)3300 bool bch2_current_has_btree_trans(struct bch_fs *c)
3301 {
3302 seqmutex_lock(&c->btree_trans_lock);
3303 struct btree_trans *trans;
3304 bool ret = false;
3305 list_for_each_entry(trans, &c->btree_trans_list, list)
3306 if (trans->locking_wait.task == current &&
3307 trans->locked) {
3308 ret = true;
3309 break;
3310 }
3311 seqmutex_unlock(&c->btree_trans_lock);
3312 return ret;
3313 }
3314
3315 static void __maybe_unused
bch2_btree_bkey_cached_common_to_text(struct printbuf * out,struct btree_bkey_cached_common * b)3316 bch2_btree_bkey_cached_common_to_text(struct printbuf *out,
3317 struct btree_bkey_cached_common *b)
3318 {
3319 struct six_lock_count c = six_lock_counts(&b->lock);
3320 struct task_struct *owner;
3321 pid_t pid;
3322
3323 rcu_read_lock();
3324 owner = READ_ONCE(b->lock.owner);
3325 pid = owner ? owner->pid : 0;
3326 rcu_read_unlock();
3327
3328 prt_printf(out, "\t%px %c l=%u %s:", b, b->cached ? 'c' : 'b',
3329 b->level, bch2_btree_id_str(b->btree_id));
3330 bch2_bpos_to_text(out, btree_node_pos(b));
3331
3332 prt_printf(out, "\t locks %u:%u:%u held by pid %u",
3333 c.n[0], c.n[1], c.n[2], pid);
3334 }
3335
bch2_btree_trans_to_text(struct printbuf * out,struct btree_trans * trans)3336 void bch2_btree_trans_to_text(struct printbuf *out, struct btree_trans *trans)
3337 {
3338 struct btree_bkey_cached_common *b;
3339 static char lock_types[] = { 'r', 'i', 'w' };
3340 struct task_struct *task = READ_ONCE(trans->locking_wait.task);
3341 unsigned l, idx;
3342
3343 /* before rcu_read_lock(): */
3344 bch2_printbuf_make_room(out, 4096);
3345
3346 if (!out->nr_tabstops) {
3347 printbuf_tabstop_push(out, 16);
3348 printbuf_tabstop_push(out, 32);
3349 }
3350
3351 prt_printf(out, "%i %s\n", task ? task->pid : 0, trans->fn);
3352
3353 /* trans->paths is rcu protected vs. freeing */
3354 rcu_read_lock();
3355 out->atomic++;
3356
3357 struct btree_path *paths = rcu_dereference(trans->paths);
3358 if (!paths)
3359 goto out;
3360
3361 unsigned long *paths_allocated = trans_paths_allocated(paths);
3362
3363 trans_for_each_path_idx_from(paths_allocated, *trans_paths_nr(paths), idx, 1) {
3364 struct btree_path *path = paths + idx;
3365 if (!path->nodes_locked)
3366 continue;
3367
3368 prt_printf(out, " path %u %c l=%u %s:",
3369 idx,
3370 path->cached ? 'c' : 'b',
3371 path->level,
3372 bch2_btree_id_str(path->btree_id));
3373 bch2_bpos_to_text(out, path->pos);
3374 prt_newline(out);
3375
3376 for (l = 0; l < BTREE_MAX_DEPTH; l++) {
3377 if (btree_node_locked(path, l) &&
3378 !IS_ERR_OR_NULL(b = (void *) READ_ONCE(path->l[l].b))) {
3379 prt_printf(out, " %c l=%u ",
3380 lock_types[btree_node_locked_type(path, l)], l);
3381 bch2_btree_bkey_cached_common_to_text(out, b);
3382 prt_newline(out);
3383 }
3384 }
3385 }
3386
3387 b = READ_ONCE(trans->locking);
3388 if (b) {
3389 prt_printf(out, " blocked for %lluus on\n",
3390 div_u64(local_clock() - trans->locking_wait.start_time, 1000));
3391 prt_printf(out, " %c", lock_types[trans->locking_wait.lock_want]);
3392 bch2_btree_bkey_cached_common_to_text(out, b);
3393 prt_newline(out);
3394 }
3395 out:
3396 --out->atomic;
3397 rcu_read_unlock();
3398 }
3399
bch2_fs_btree_iter_exit(struct bch_fs * c)3400 void bch2_fs_btree_iter_exit(struct bch_fs *c)
3401 {
3402 struct btree_transaction_stats *s;
3403 struct btree_trans *trans;
3404 int cpu;
3405
3406 if (c->btree_trans_bufs)
3407 for_each_possible_cpu(cpu) {
3408 struct btree_trans *trans =
3409 per_cpu_ptr(c->btree_trans_bufs, cpu)->trans;
3410
3411 if (trans) {
3412 seqmutex_lock(&c->btree_trans_lock);
3413 list_del(&trans->list);
3414 seqmutex_unlock(&c->btree_trans_lock);
3415 }
3416 kfree(trans);
3417 }
3418 free_percpu(c->btree_trans_bufs);
3419
3420 trans = list_first_entry_or_null(&c->btree_trans_list, struct btree_trans, list);
3421 if (trans)
3422 panic("%s leaked btree_trans\n", trans->fn);
3423
3424 for (s = c->btree_transaction_stats;
3425 s < c->btree_transaction_stats + ARRAY_SIZE(c->btree_transaction_stats);
3426 s++) {
3427 kfree(s->max_paths_text);
3428 bch2_time_stats_exit(&s->lock_hold_times);
3429 }
3430
3431 if (c->btree_trans_barrier_initialized) {
3432 synchronize_srcu_expedited(&c->btree_trans_barrier);
3433 cleanup_srcu_struct(&c->btree_trans_barrier);
3434 }
3435 mempool_exit(&c->btree_trans_mem_pool);
3436 mempool_exit(&c->btree_trans_pool);
3437 }
3438
bch2_fs_btree_iter_init_early(struct bch_fs * c)3439 void bch2_fs_btree_iter_init_early(struct bch_fs *c)
3440 {
3441 struct btree_transaction_stats *s;
3442
3443 for (s = c->btree_transaction_stats;
3444 s < c->btree_transaction_stats + ARRAY_SIZE(c->btree_transaction_stats);
3445 s++) {
3446 bch2_time_stats_init(&s->duration);
3447 bch2_time_stats_init(&s->lock_hold_times);
3448 mutex_init(&s->lock);
3449 }
3450
3451 INIT_LIST_HEAD(&c->btree_trans_list);
3452 seqmutex_init(&c->btree_trans_lock);
3453 }
3454
bch2_fs_btree_iter_init(struct bch_fs * c)3455 int bch2_fs_btree_iter_init(struct bch_fs *c)
3456 {
3457 int ret;
3458
3459 c->btree_trans_bufs = alloc_percpu(struct btree_trans_buf);
3460 if (!c->btree_trans_bufs)
3461 return -ENOMEM;
3462
3463 ret = mempool_init_kmalloc_pool(&c->btree_trans_pool, 1,
3464 sizeof(struct btree_trans)) ?:
3465 mempool_init_kmalloc_pool(&c->btree_trans_mem_pool, 1,
3466 BTREE_TRANS_MEM_MAX) ?:
3467 init_srcu_struct(&c->btree_trans_barrier);
3468 if (ret)
3469 return ret;
3470
3471 /*
3472 * static annotation (hackily done) for lock ordering of reclaim vs.
3473 * btree node locks:
3474 */
3475 #ifdef CONFIG_LOCKDEP
3476 fs_reclaim_acquire(GFP_KERNEL);
3477 struct btree_trans *trans = bch2_trans_get(c);
3478 trans_set_locked(trans);
3479 bch2_trans_put(trans);
3480 fs_reclaim_release(GFP_KERNEL);
3481 #endif
3482
3483 c->btree_trans_barrier_initialized = true;
3484 return 0;
3485
3486 }
3487