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 unsigned i;
225
226 EBUG_ON(path->btree_id >= BTREE_ID_NR);
227
228 for (i = 0; i < (!path->cached ? BTREE_MAX_DEPTH : 1); i++) {
229 if (!path->l[i].b) {
230 BUG_ON(!path->cached &&
231 bch2_btree_id_root(c, path->btree_id)->b->c.level > i);
232 break;
233 }
234
235 bch2_btree_path_verify_level(trans, path, i);
236 }
237
238 bch2_btree_path_verify_locks(path);
239 }
240
bch2_trans_verify_paths(struct btree_trans * trans)241 void bch2_trans_verify_paths(struct btree_trans *trans)
242 {
243 struct btree_path *path;
244 unsigned iter;
245
246 trans_for_each_path(trans, path, iter)
247 bch2_btree_path_verify(trans, path);
248 }
249
bch2_btree_iter_verify(struct btree_iter * iter)250 static void bch2_btree_iter_verify(struct btree_iter *iter)
251 {
252 struct btree_trans *trans = iter->trans;
253
254 BUG_ON(iter->btree_id >= BTREE_ID_NR);
255
256 BUG_ON(!!(iter->flags & BTREE_ITER_CACHED) != btree_iter_path(trans, iter)->cached);
257
258 BUG_ON((iter->flags & BTREE_ITER_IS_EXTENTS) &&
259 (iter->flags & BTREE_ITER_ALL_SNAPSHOTS));
260
261 BUG_ON(!(iter->flags & __BTREE_ITER_ALL_SNAPSHOTS) &&
262 (iter->flags & BTREE_ITER_ALL_SNAPSHOTS) &&
263 !btree_type_has_snapshot_field(iter->btree_id));
264
265 if (iter->update_path)
266 bch2_btree_path_verify(trans, &trans->paths[iter->update_path]);
267 bch2_btree_path_verify(trans, btree_iter_path(trans, iter));
268 }
269
bch2_btree_iter_verify_entry_exit(struct btree_iter * iter)270 static void bch2_btree_iter_verify_entry_exit(struct btree_iter *iter)
271 {
272 BUG_ON((iter->flags & BTREE_ITER_FILTER_SNAPSHOTS) &&
273 !iter->pos.snapshot);
274
275 BUG_ON(!(iter->flags & BTREE_ITER_ALL_SNAPSHOTS) &&
276 iter->pos.snapshot != iter->snapshot);
277
278 BUG_ON(bkey_lt(iter->pos, bkey_start_pos(&iter->k)) ||
279 bkey_gt(iter->pos, iter->k.p));
280 }
281
bch2_btree_iter_verify_ret(struct btree_iter * iter,struct bkey_s_c k)282 static int bch2_btree_iter_verify_ret(struct btree_iter *iter, struct bkey_s_c k)
283 {
284 struct btree_trans *trans = iter->trans;
285 struct btree_iter copy;
286 struct bkey_s_c prev;
287 int ret = 0;
288
289 if (!bch2_debug_check_iterators)
290 return 0;
291
292 if (!(iter->flags & BTREE_ITER_FILTER_SNAPSHOTS))
293 return 0;
294
295 if (bkey_err(k) || !k.k)
296 return 0;
297
298 BUG_ON(!bch2_snapshot_is_ancestor(trans->c,
299 iter->snapshot,
300 k.k->p.snapshot));
301
302 bch2_trans_iter_init(trans, ©, iter->btree_id, iter->pos,
303 BTREE_ITER_NOPRESERVE|
304 BTREE_ITER_ALL_SNAPSHOTS);
305 prev = bch2_btree_iter_prev(©);
306 if (!prev.k)
307 goto out;
308
309 ret = bkey_err(prev);
310 if (ret)
311 goto out;
312
313 if (bkey_eq(prev.k->p, k.k->p) &&
314 bch2_snapshot_is_ancestor(trans->c, iter->snapshot,
315 prev.k->p.snapshot) > 0) {
316 struct printbuf buf1 = PRINTBUF, buf2 = PRINTBUF;
317
318 bch2_bkey_to_text(&buf1, k.k);
319 bch2_bkey_to_text(&buf2, prev.k);
320
321 panic("iter snap %u\n"
322 "k %s\n"
323 "prev %s\n",
324 iter->snapshot,
325 buf1.buf, buf2.buf);
326 }
327 out:
328 bch2_trans_iter_exit(trans, ©);
329 return ret;
330 }
331
bch2_assert_pos_locked(struct btree_trans * trans,enum btree_id id,struct bpos pos,bool key_cache)332 void bch2_assert_pos_locked(struct btree_trans *trans, enum btree_id id,
333 struct bpos pos, bool key_cache)
334 {
335 struct btree_path *path;
336 struct trans_for_each_path_inorder_iter iter;
337 struct printbuf buf = PRINTBUF;
338
339 btree_trans_sort_paths(trans);
340
341 trans_for_each_path_inorder(trans, path, iter) {
342 int cmp = cmp_int(path->btree_id, id) ?:
343 cmp_int(path->cached, key_cache);
344
345 if (cmp > 0)
346 break;
347 if (cmp < 0)
348 continue;
349
350 if (!btree_node_locked(path, 0) ||
351 !path->should_be_locked)
352 continue;
353
354 if (!key_cache) {
355 if (bkey_ge(pos, path->l[0].b->data->min_key) &&
356 bkey_le(pos, path->l[0].b->key.k.p))
357 return;
358 } else {
359 if (bkey_eq(pos, path->pos))
360 return;
361 }
362 }
363
364 bch2_dump_trans_paths_updates(trans);
365 bch2_bpos_to_text(&buf, pos);
366
367 panic("not locked: %s %s%s\n",
368 bch2_btree_id_str(id), buf.buf,
369 key_cache ? " cached" : "");
370 }
371
372 #else
373
bch2_btree_path_verify_level(struct btree_trans * trans,struct btree_path * path,unsigned l)374 static inline void bch2_btree_path_verify_level(struct btree_trans *trans,
375 struct btree_path *path, unsigned l) {}
bch2_btree_path_verify(struct btree_trans * trans,struct btree_path * path)376 static inline void bch2_btree_path_verify(struct btree_trans *trans,
377 struct btree_path *path) {}
bch2_btree_iter_verify(struct btree_iter * iter)378 static inline void bch2_btree_iter_verify(struct btree_iter *iter) {}
bch2_btree_iter_verify_entry_exit(struct btree_iter * iter)379 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)380 static inline int bch2_btree_iter_verify_ret(struct btree_iter *iter, struct bkey_s_c k) { return 0; }
381
382 #endif
383
384 /* Btree path: fixups after btree updates */
385
btree_node_iter_set_set_pos(struct btree_node_iter * iter,struct btree * b,struct bset_tree * t,struct bkey_packed * k)386 static void btree_node_iter_set_set_pos(struct btree_node_iter *iter,
387 struct btree *b,
388 struct bset_tree *t,
389 struct bkey_packed *k)
390 {
391 struct btree_node_iter_set *set;
392
393 btree_node_iter_for_each(iter, set)
394 if (set->end == t->end_offset) {
395 set->k = __btree_node_key_to_offset(b, k);
396 bch2_btree_node_iter_sort(iter, b);
397 return;
398 }
399
400 bch2_btree_node_iter_push(iter, b, k, btree_bkey_last(b, t));
401 }
402
__bch2_btree_path_fix_key_modified(struct btree_path * path,struct btree * b,struct bkey_packed * where)403 static void __bch2_btree_path_fix_key_modified(struct btree_path *path,
404 struct btree *b,
405 struct bkey_packed *where)
406 {
407 struct btree_path_level *l = &path->l[b->c.level];
408
409 if (where != bch2_btree_node_iter_peek_all(&l->iter, l->b))
410 return;
411
412 if (bkey_iter_pos_cmp(l->b, where, &path->pos) < 0)
413 bch2_btree_node_iter_advance(&l->iter, l->b);
414 }
415
bch2_btree_path_fix_key_modified(struct btree_trans * trans,struct btree * b,struct bkey_packed * where)416 void bch2_btree_path_fix_key_modified(struct btree_trans *trans,
417 struct btree *b,
418 struct bkey_packed *where)
419 {
420 struct btree_path *path;
421 unsigned i;
422
423 trans_for_each_path_with_node(trans, b, path, i) {
424 __bch2_btree_path_fix_key_modified(path, b, where);
425 bch2_btree_path_verify_level(trans, path, b->c.level);
426 }
427 }
428
__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)429 static void __bch2_btree_node_iter_fix(struct btree_path *path,
430 struct btree *b,
431 struct btree_node_iter *node_iter,
432 struct bset_tree *t,
433 struct bkey_packed *where,
434 unsigned clobber_u64s,
435 unsigned new_u64s)
436 {
437 const struct bkey_packed *end = btree_bkey_last(b, t);
438 struct btree_node_iter_set *set;
439 unsigned offset = __btree_node_key_to_offset(b, where);
440 int shift = new_u64s - clobber_u64s;
441 unsigned old_end = t->end_offset - shift;
442 unsigned orig_iter_pos = node_iter->data[0].k;
443 bool iter_current_key_modified =
444 orig_iter_pos >= offset &&
445 orig_iter_pos <= offset + clobber_u64s;
446
447 btree_node_iter_for_each(node_iter, set)
448 if (set->end == old_end)
449 goto found;
450
451 /* didn't find the bset in the iterator - might have to readd it: */
452 if (new_u64s &&
453 bkey_iter_pos_cmp(b, where, &path->pos) >= 0) {
454 bch2_btree_node_iter_push(node_iter, b, where, end);
455 goto fixup_done;
456 } else {
457 /* Iterator is after key that changed */
458 return;
459 }
460 found:
461 set->end = t->end_offset;
462
463 /* Iterator hasn't gotten to the key that changed yet: */
464 if (set->k < offset)
465 return;
466
467 if (new_u64s &&
468 bkey_iter_pos_cmp(b, where, &path->pos) >= 0) {
469 set->k = offset;
470 } else if (set->k < offset + clobber_u64s) {
471 set->k = offset + new_u64s;
472 if (set->k == set->end)
473 bch2_btree_node_iter_set_drop(node_iter, set);
474 } else {
475 /* Iterator is after key that changed */
476 set->k = (int) set->k + shift;
477 return;
478 }
479
480 bch2_btree_node_iter_sort(node_iter, b);
481 fixup_done:
482 if (node_iter->data[0].k != orig_iter_pos)
483 iter_current_key_modified = true;
484
485 /*
486 * When a new key is added, and the node iterator now points to that
487 * key, the iterator might have skipped past deleted keys that should
488 * come after the key the iterator now points to. We have to rewind to
489 * before those deleted keys - otherwise
490 * bch2_btree_node_iter_prev_all() breaks:
491 */
492 if (!bch2_btree_node_iter_end(node_iter) &&
493 iter_current_key_modified &&
494 b->c.level) {
495 struct bkey_packed *k, *k2, *p;
496
497 k = bch2_btree_node_iter_peek_all(node_iter, b);
498
499 for_each_bset(b, t) {
500 bool set_pos = false;
501
502 if (node_iter->data[0].end == t->end_offset)
503 continue;
504
505 k2 = bch2_btree_node_iter_bset_pos(node_iter, b, t);
506
507 while ((p = bch2_bkey_prev_all(b, t, k2)) &&
508 bkey_iter_cmp(b, k, p) < 0) {
509 k2 = p;
510 set_pos = true;
511 }
512
513 if (set_pos)
514 btree_node_iter_set_set_pos(node_iter,
515 b, t, k2);
516 }
517 }
518 }
519
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)520 void bch2_btree_node_iter_fix(struct btree_trans *trans,
521 struct btree_path *path,
522 struct btree *b,
523 struct btree_node_iter *node_iter,
524 struct bkey_packed *where,
525 unsigned clobber_u64s,
526 unsigned new_u64s)
527 {
528 struct bset_tree *t = bch2_bkey_to_bset_inlined(b, where);
529 struct btree_path *linked;
530 unsigned i;
531
532 if (node_iter != &path->l[b->c.level].iter) {
533 __bch2_btree_node_iter_fix(path, b, node_iter, t,
534 where, clobber_u64s, new_u64s);
535
536 if (bch2_debug_check_iterators)
537 bch2_btree_node_iter_verify(node_iter, b);
538 }
539
540 trans_for_each_path_with_node(trans, b, linked, i) {
541 __bch2_btree_node_iter_fix(linked, b,
542 &linked->l[b->c.level].iter, t,
543 where, clobber_u64s, new_u64s);
544 bch2_btree_path_verify_level(trans, linked, b->c.level);
545 }
546 }
547
548 /* Btree path level: pointer to a particular btree node and node iter */
549
__btree_iter_unpack(struct bch_fs * c,struct btree_path_level * l,struct bkey * u,struct bkey_packed * k)550 static inline struct bkey_s_c __btree_iter_unpack(struct bch_fs *c,
551 struct btree_path_level *l,
552 struct bkey *u,
553 struct bkey_packed *k)
554 {
555 if (unlikely(!k)) {
556 /*
557 * signal to bch2_btree_iter_peek_slot() that we're currently at
558 * a hole
559 */
560 u->type = KEY_TYPE_deleted;
561 return bkey_s_c_null;
562 }
563
564 return bkey_disassemble(l->b, k, u);
565 }
566
btree_path_level_peek_all(struct bch_fs * c,struct btree_path_level * l,struct bkey * u)567 static inline struct bkey_s_c btree_path_level_peek_all(struct bch_fs *c,
568 struct btree_path_level *l,
569 struct bkey *u)
570 {
571 return __btree_iter_unpack(c, l, u,
572 bch2_btree_node_iter_peek_all(&l->iter, l->b));
573 }
574
btree_path_level_peek(struct btree_trans * trans,struct btree_path * path,struct btree_path_level * l,struct bkey * u)575 static inline struct bkey_s_c btree_path_level_peek(struct btree_trans *trans,
576 struct btree_path *path,
577 struct btree_path_level *l,
578 struct bkey *u)
579 {
580 struct bkey_s_c k = __btree_iter_unpack(trans->c, l, u,
581 bch2_btree_node_iter_peek(&l->iter, l->b));
582
583 path->pos = k.k ? k.k->p : l->b->key.k.p;
584 trans->paths_sorted = false;
585 bch2_btree_path_verify_level(trans, path, l - path->l);
586 return k;
587 }
588
btree_path_level_prev(struct btree_trans * trans,struct btree_path * path,struct btree_path_level * l,struct bkey * u)589 static inline struct bkey_s_c btree_path_level_prev(struct btree_trans *trans,
590 struct btree_path *path,
591 struct btree_path_level *l,
592 struct bkey *u)
593 {
594 struct bkey_s_c k = __btree_iter_unpack(trans->c, l, u,
595 bch2_btree_node_iter_prev(&l->iter, l->b));
596
597 path->pos = k.k ? k.k->p : l->b->data->min_key;
598 trans->paths_sorted = false;
599 bch2_btree_path_verify_level(trans, path, l - path->l);
600 return k;
601 }
602
btree_path_advance_to_pos(struct btree_path * path,struct btree_path_level * l,int max_advance)603 static inline bool btree_path_advance_to_pos(struct btree_path *path,
604 struct btree_path_level *l,
605 int max_advance)
606 {
607 struct bkey_packed *k;
608 int nr_advanced = 0;
609
610 while ((k = bch2_btree_node_iter_peek_all(&l->iter, l->b)) &&
611 bkey_iter_pos_cmp(l->b, k, &path->pos) < 0) {
612 if (max_advance > 0 && nr_advanced >= max_advance)
613 return false;
614
615 bch2_btree_node_iter_advance(&l->iter, l->b);
616 nr_advanced++;
617 }
618
619 return true;
620 }
621
__btree_path_level_init(struct btree_path * path,unsigned level)622 static inline void __btree_path_level_init(struct btree_path *path,
623 unsigned level)
624 {
625 struct btree_path_level *l = &path->l[level];
626
627 bch2_btree_node_iter_init(&l->iter, l->b, &path->pos);
628
629 /*
630 * Iterators to interior nodes should always be pointed at the first non
631 * whiteout:
632 */
633 if (level)
634 bch2_btree_node_iter_peek(&l->iter, l->b);
635 }
636
bch2_btree_path_level_init(struct btree_trans * trans,struct btree_path * path,struct btree * b)637 void bch2_btree_path_level_init(struct btree_trans *trans,
638 struct btree_path *path,
639 struct btree *b)
640 {
641 BUG_ON(path->cached);
642
643 EBUG_ON(!btree_path_pos_in_node(path, b));
644
645 path->l[b->c.level].lock_seq = six_lock_seq(&b->c.lock);
646 path->l[b->c.level].b = b;
647 __btree_path_level_init(path, b->c.level);
648 }
649
650 /* Btree path: fixups after btree node updates: */
651
bch2_trans_revalidate_updates_in_node(struct btree_trans * trans,struct btree * b)652 static void bch2_trans_revalidate_updates_in_node(struct btree_trans *trans, struct btree *b)
653 {
654 struct bch_fs *c = trans->c;
655
656 trans_for_each_update(trans, i)
657 if (!i->cached &&
658 i->level == b->c.level &&
659 i->btree_id == b->c.btree_id &&
660 bpos_cmp(i->k->k.p, b->data->min_key) >= 0 &&
661 bpos_cmp(i->k->k.p, b->data->max_key) <= 0) {
662 i->old_v = bch2_btree_path_peek_slot(trans->paths + i->path, &i->old_k).v;
663
664 if (unlikely(trans->journal_replay_not_finished)) {
665 struct bkey_i *j_k =
666 bch2_journal_keys_peek_slot(c, i->btree_id, i->level,
667 i->k->k.p);
668
669 if (j_k) {
670 i->old_k = j_k->k;
671 i->old_v = &j_k->v;
672 }
673 }
674 }
675 }
676
677 /*
678 * A btree node is being replaced - update the iterator to point to the new
679 * node:
680 */
bch2_trans_node_add(struct btree_trans * trans,struct btree_path * path,struct btree * b)681 void bch2_trans_node_add(struct btree_trans *trans,
682 struct btree_path *path,
683 struct btree *b)
684 {
685 struct btree_path *prev;
686
687 BUG_ON(!btree_path_pos_in_node(path, b));
688
689 while ((prev = prev_btree_path(trans, path)) &&
690 btree_path_pos_in_node(prev, b))
691 path = prev;
692
693 for (;
694 path && btree_path_pos_in_node(path, b);
695 path = next_btree_path(trans, path))
696 if (path->uptodate == BTREE_ITER_UPTODATE && !path->cached) {
697 enum btree_node_locked_type t =
698 btree_lock_want(path, b->c.level);
699
700 if (t != BTREE_NODE_UNLOCKED) {
701 btree_node_unlock(trans, path, b->c.level);
702 six_lock_increment(&b->c.lock, (enum six_lock_type) t);
703 mark_btree_node_locked(trans, path, b->c.level, t);
704 }
705
706 bch2_btree_path_level_init(trans, path, b);
707 }
708
709 bch2_trans_revalidate_updates_in_node(trans, b);
710 }
711
712 /*
713 * A btree node has been modified in such a way as to invalidate iterators - fix
714 * them:
715 */
bch2_trans_node_reinit_iter(struct btree_trans * trans,struct btree * b)716 void bch2_trans_node_reinit_iter(struct btree_trans *trans, struct btree *b)
717 {
718 struct btree_path *path;
719 unsigned i;
720
721 trans_for_each_path_with_node(trans, b, path, i)
722 __btree_path_level_init(path, b->c.level);
723
724 bch2_trans_revalidate_updates_in_node(trans, b);
725 }
726
727 /* Btree path: traverse, set_pos: */
728
btree_path_lock_root(struct btree_trans * trans,struct btree_path * path,unsigned depth_want,unsigned long trace_ip)729 static inline int btree_path_lock_root(struct btree_trans *trans,
730 struct btree_path *path,
731 unsigned depth_want,
732 unsigned long trace_ip)
733 {
734 struct bch_fs *c = trans->c;
735 struct btree *b, **rootp = &bch2_btree_id_root(c, path->btree_id)->b;
736 enum six_lock_type lock_type;
737 unsigned i;
738 int ret;
739
740 EBUG_ON(path->nodes_locked);
741
742 while (1) {
743 b = READ_ONCE(*rootp);
744 path->level = READ_ONCE(b->c.level);
745
746 if (unlikely(path->level < depth_want)) {
747 /*
748 * the root is at a lower depth than the depth we want:
749 * got to the end of the btree, or we're walking nodes
750 * greater than some depth and there are no nodes >=
751 * that depth
752 */
753 path->level = depth_want;
754 for (i = path->level; i < BTREE_MAX_DEPTH; i++)
755 path->l[i].b = NULL;
756 return 1;
757 }
758
759 lock_type = __btree_lock_want(path, path->level);
760 ret = btree_node_lock(trans, path, &b->c,
761 path->level, lock_type, trace_ip);
762 if (unlikely(ret)) {
763 if (bch2_err_matches(ret, BCH_ERR_lock_fail_root_changed))
764 continue;
765 if (bch2_err_matches(ret, BCH_ERR_transaction_restart))
766 return ret;
767 BUG();
768 }
769
770 if (likely(b == READ_ONCE(*rootp) &&
771 b->c.level == path->level &&
772 !race_fault())) {
773 for (i = 0; i < path->level; i++)
774 path->l[i].b = ERR_PTR(-BCH_ERR_no_btree_node_lock_root);
775 path->l[path->level].b = b;
776 for (i = path->level + 1; i < BTREE_MAX_DEPTH; i++)
777 path->l[i].b = NULL;
778
779 mark_btree_node_locked(trans, path, path->level,
780 (enum btree_node_locked_type) lock_type);
781 bch2_btree_path_level_init(trans, path, b);
782 return 0;
783 }
784
785 six_unlock_type(&b->c.lock, lock_type);
786 }
787 }
788
789 noinline
btree_path_prefetch(struct btree_trans * trans,struct btree_path * path)790 static int btree_path_prefetch(struct btree_trans *trans, struct btree_path *path)
791 {
792 struct bch_fs *c = trans->c;
793 struct btree_path_level *l = path_l(path);
794 struct btree_node_iter node_iter = l->iter;
795 struct bkey_packed *k;
796 struct bkey_buf tmp;
797 unsigned nr = test_bit(BCH_FS_started, &c->flags)
798 ? (path->level > 1 ? 0 : 2)
799 : (path->level > 1 ? 1 : 16);
800 bool was_locked = btree_node_locked(path, path->level);
801 int ret = 0;
802
803 bch2_bkey_buf_init(&tmp);
804
805 while (nr-- && !ret) {
806 if (!bch2_btree_node_relock(trans, path, path->level))
807 break;
808
809 bch2_btree_node_iter_advance(&node_iter, l->b);
810 k = bch2_btree_node_iter_peek(&node_iter, l->b);
811 if (!k)
812 break;
813
814 bch2_bkey_buf_unpack(&tmp, c, l->b, k);
815 ret = bch2_btree_node_prefetch(trans, path, tmp.k, path->btree_id,
816 path->level - 1);
817 }
818
819 if (!was_locked)
820 btree_node_unlock(trans, path, path->level);
821
822 bch2_bkey_buf_exit(&tmp, c);
823 return ret;
824 }
825
btree_path_prefetch_j(struct btree_trans * trans,struct btree_path * path,struct btree_and_journal_iter * jiter)826 static int btree_path_prefetch_j(struct btree_trans *trans, struct btree_path *path,
827 struct btree_and_journal_iter *jiter)
828 {
829 struct bch_fs *c = trans->c;
830 struct bkey_s_c k;
831 struct bkey_buf tmp;
832 unsigned nr = test_bit(BCH_FS_started, &c->flags)
833 ? (path->level > 1 ? 0 : 2)
834 : (path->level > 1 ? 1 : 16);
835 bool was_locked = btree_node_locked(path, path->level);
836 int ret = 0;
837
838 bch2_bkey_buf_init(&tmp);
839
840 while (nr-- && !ret) {
841 if (!bch2_btree_node_relock(trans, path, path->level))
842 break;
843
844 bch2_btree_and_journal_iter_advance(jiter);
845 k = bch2_btree_and_journal_iter_peek(jiter);
846 if (!k.k)
847 break;
848
849 bch2_bkey_buf_reassemble(&tmp, c, k);
850 ret = bch2_btree_node_prefetch(trans, path, tmp.k, path->btree_id,
851 path->level - 1);
852 }
853
854 if (!was_locked)
855 btree_node_unlock(trans, path, path->level);
856
857 bch2_bkey_buf_exit(&tmp, c);
858 return ret;
859 }
860
btree_node_mem_ptr_set(struct btree_trans * trans,struct btree_path * path,unsigned plevel,struct btree * b)861 static noinline void btree_node_mem_ptr_set(struct btree_trans *trans,
862 struct btree_path *path,
863 unsigned plevel, struct btree *b)
864 {
865 struct btree_path_level *l = &path->l[plevel];
866 bool locked = btree_node_locked(path, plevel);
867 struct bkey_packed *k;
868 struct bch_btree_ptr_v2 *bp;
869
870 if (!bch2_btree_node_relock(trans, path, plevel))
871 return;
872
873 k = bch2_btree_node_iter_peek_all(&l->iter, l->b);
874 BUG_ON(k->type != KEY_TYPE_btree_ptr_v2);
875
876 bp = (void *) bkeyp_val(&l->b->format, k);
877 bp->mem_ptr = (unsigned long)b;
878
879 if (!locked)
880 btree_node_unlock(trans, path, plevel);
881 }
882
btree_node_iter_and_journal_peek(struct btree_trans * trans,struct btree_path * path,unsigned flags,struct bkey_buf * out)883 static noinline int btree_node_iter_and_journal_peek(struct btree_trans *trans,
884 struct btree_path *path,
885 unsigned flags,
886 struct bkey_buf *out)
887 {
888 struct bch_fs *c = trans->c;
889 struct btree_path_level *l = path_l(path);
890 struct btree_and_journal_iter jiter;
891 struct bkey_s_c k;
892 int ret = 0;
893
894 __bch2_btree_and_journal_iter_init_node_iter(&jiter, c, l->b, l->iter, path->pos);
895
896 k = bch2_btree_and_journal_iter_peek(&jiter);
897
898 bch2_bkey_buf_reassemble(out, c, k);
899
900 if ((flags & BTREE_ITER_PREFETCH) &&
901 c->opts.btree_node_prefetch)
902 ret = btree_path_prefetch_j(trans, path, &jiter);
903
904 bch2_btree_and_journal_iter_exit(&jiter);
905 return ret;
906 }
907
btree_path_down(struct btree_trans * trans,struct btree_path * path,unsigned flags,unsigned long trace_ip)908 static __always_inline int btree_path_down(struct btree_trans *trans,
909 struct btree_path *path,
910 unsigned flags,
911 unsigned long trace_ip)
912 {
913 struct bch_fs *c = trans->c;
914 struct btree_path_level *l = path_l(path);
915 struct btree *b;
916 unsigned level = path->level - 1;
917 enum six_lock_type lock_type = __btree_lock_want(path, level);
918 struct bkey_buf tmp;
919 int ret;
920
921 EBUG_ON(!btree_node_locked(path, path->level));
922
923 bch2_bkey_buf_init(&tmp);
924
925 if (unlikely(trans->journal_replay_not_finished)) {
926 ret = btree_node_iter_and_journal_peek(trans, path, flags, &tmp);
927 if (ret)
928 goto err;
929 } else {
930 bch2_bkey_buf_unpack(&tmp, c, l->b,
931 bch2_btree_node_iter_peek(&l->iter, l->b));
932
933 if ((flags & BTREE_ITER_PREFETCH) &&
934 c->opts.btree_node_prefetch) {
935 ret = btree_path_prefetch(trans, path);
936 if (ret)
937 goto err;
938 }
939 }
940
941 b = bch2_btree_node_get(trans, path, tmp.k, level, lock_type, trace_ip);
942 ret = PTR_ERR_OR_ZERO(b);
943 if (unlikely(ret))
944 goto err;
945
946 if (likely(!trans->journal_replay_not_finished &&
947 tmp.k->k.type == KEY_TYPE_btree_ptr_v2) &&
948 unlikely(b != btree_node_mem_ptr(tmp.k)))
949 btree_node_mem_ptr_set(trans, path, level + 1, b);
950
951 if (btree_node_read_locked(path, level + 1))
952 btree_node_unlock(trans, path, level + 1);
953
954 mark_btree_node_locked(trans, path, level,
955 (enum btree_node_locked_type) lock_type);
956 path->level = level;
957 bch2_btree_path_level_init(trans, path, b);
958
959 bch2_btree_path_verify_locks(path);
960 err:
961 bch2_bkey_buf_exit(&tmp, c);
962 return ret;
963 }
964
965
bch2_btree_path_traverse_all(struct btree_trans * trans)966 static int bch2_btree_path_traverse_all(struct btree_trans *trans)
967 {
968 struct bch_fs *c = trans->c;
969 struct btree_path *path;
970 unsigned long trace_ip = _RET_IP_;
971 unsigned i;
972 int ret = 0;
973
974 if (trans->in_traverse_all)
975 return -BCH_ERR_transaction_restart_in_traverse_all;
976
977 trans->in_traverse_all = true;
978 retry_all:
979 trans->restarted = 0;
980 trans->last_restarted_ip = 0;
981
982 trans_for_each_path(trans, path, i)
983 path->should_be_locked = false;
984
985 btree_trans_sort_paths(trans);
986
987 bch2_trans_unlock(trans);
988 cond_resched();
989
990 if (unlikely(trans->memory_allocation_failure)) {
991 struct closure cl;
992
993 closure_init_stack(&cl);
994
995 do {
996 ret = bch2_btree_cache_cannibalize_lock(trans, &cl);
997 closure_sync(&cl);
998 } while (ret);
999 }
1000
1001 /* Now, redo traversals in correct order: */
1002 i = 0;
1003 while (i < trans->nr_sorted) {
1004 btree_path_idx_t idx = trans->sorted[i];
1005
1006 /*
1007 * Traversing a path can cause another path to be added at about
1008 * the same position:
1009 */
1010 if (trans->paths[idx].uptodate) {
1011 __btree_path_get(&trans->paths[idx], false);
1012 ret = bch2_btree_path_traverse_one(trans, idx, 0, _THIS_IP_);
1013 __btree_path_put(&trans->paths[idx], false);
1014
1015 if (bch2_err_matches(ret, BCH_ERR_transaction_restart) ||
1016 bch2_err_matches(ret, ENOMEM))
1017 goto retry_all;
1018 if (ret)
1019 goto err;
1020 } else {
1021 i++;
1022 }
1023 }
1024
1025 /*
1026 * We used to assert that all paths had been traversed here
1027 * (path->uptodate < BTREE_ITER_NEED_TRAVERSE); however, since
1028 * path->should_be_locked is not set yet, we might have unlocked and
1029 * then failed to relock a path - that's fine.
1030 */
1031 err:
1032 bch2_btree_cache_cannibalize_unlock(trans);
1033
1034 trans->in_traverse_all = false;
1035
1036 trace_and_count(c, trans_traverse_all, trans, trace_ip);
1037 return ret;
1038 }
1039
btree_path_check_pos_in_node(struct btree_path * path,unsigned l,int check_pos)1040 static inline bool btree_path_check_pos_in_node(struct btree_path *path,
1041 unsigned l, int check_pos)
1042 {
1043 if (check_pos < 0 && btree_path_pos_before_node(path, path->l[l].b))
1044 return false;
1045 if (check_pos > 0 && btree_path_pos_after_node(path, path->l[l].b))
1046 return false;
1047 return true;
1048 }
1049
btree_path_good_node(struct btree_trans * trans,struct btree_path * path,unsigned l,int check_pos)1050 static inline bool btree_path_good_node(struct btree_trans *trans,
1051 struct btree_path *path,
1052 unsigned l, int check_pos)
1053 {
1054 return is_btree_node(path, l) &&
1055 bch2_btree_node_relock(trans, path, l) &&
1056 btree_path_check_pos_in_node(path, l, check_pos);
1057 }
1058
btree_path_set_level_down(struct btree_trans * trans,struct btree_path * path,unsigned new_level)1059 static void btree_path_set_level_down(struct btree_trans *trans,
1060 struct btree_path *path,
1061 unsigned new_level)
1062 {
1063 unsigned l;
1064
1065 path->level = new_level;
1066
1067 for (l = path->level + 1; l < BTREE_MAX_DEPTH; l++)
1068 if (btree_lock_want(path, l) == BTREE_NODE_UNLOCKED)
1069 btree_node_unlock(trans, path, l);
1070
1071 btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE);
1072 bch2_btree_path_verify(trans, path);
1073 }
1074
__btree_path_up_until_good_node(struct btree_trans * trans,struct btree_path * path,int check_pos)1075 static noinline unsigned __btree_path_up_until_good_node(struct btree_trans *trans,
1076 struct btree_path *path,
1077 int check_pos)
1078 {
1079 unsigned i, l = path->level;
1080 again:
1081 while (btree_path_node(path, l) &&
1082 !btree_path_good_node(trans, path, l, check_pos))
1083 __btree_path_set_level_up(trans, path, l++);
1084
1085 /* If we need intent locks, take them too: */
1086 for (i = l + 1;
1087 i < path->locks_want && btree_path_node(path, i);
1088 i++)
1089 if (!bch2_btree_node_relock(trans, path, i)) {
1090 while (l <= i)
1091 __btree_path_set_level_up(trans, path, l++);
1092 goto again;
1093 }
1094
1095 return l;
1096 }
1097
btree_path_up_until_good_node(struct btree_trans * trans,struct btree_path * path,int check_pos)1098 static inline unsigned btree_path_up_until_good_node(struct btree_trans *trans,
1099 struct btree_path *path,
1100 int check_pos)
1101 {
1102 return likely(btree_node_locked(path, path->level) &&
1103 btree_path_check_pos_in_node(path, path->level, check_pos))
1104 ? path->level
1105 : __btree_path_up_until_good_node(trans, path, check_pos);
1106 }
1107
1108 /*
1109 * This is the main state machine for walking down the btree - walks down to a
1110 * specified depth
1111 *
1112 * Returns 0 on success, -EIO on error (error reading in a btree node).
1113 *
1114 * On error, caller (peek_node()/peek_key()) must return NULL; the error is
1115 * stashed in the iterator and returned from bch2_trans_exit().
1116 */
bch2_btree_path_traverse_one(struct btree_trans * trans,btree_path_idx_t path_idx,unsigned flags,unsigned long trace_ip)1117 int bch2_btree_path_traverse_one(struct btree_trans *trans,
1118 btree_path_idx_t path_idx,
1119 unsigned flags,
1120 unsigned long trace_ip)
1121 {
1122 struct btree_path *path = &trans->paths[path_idx];
1123 unsigned depth_want = path->level;
1124 int ret = -((int) trans->restarted);
1125
1126 if (unlikely(ret))
1127 goto out;
1128
1129 if (unlikely(!trans->srcu_held))
1130 bch2_trans_srcu_lock(trans);
1131
1132 /*
1133 * Ensure we obey path->should_be_locked: if it's set, we can't unlock
1134 * and re-traverse the path without a transaction restart:
1135 */
1136 if (path->should_be_locked) {
1137 ret = bch2_btree_path_relock(trans, path, trace_ip);
1138 goto out;
1139 }
1140
1141 if (path->cached) {
1142 ret = bch2_btree_path_traverse_cached(trans, path, flags);
1143 goto out;
1144 }
1145
1146 path = &trans->paths[path_idx];
1147
1148 if (unlikely(path->level >= BTREE_MAX_DEPTH))
1149 goto out;
1150
1151 path->level = btree_path_up_until_good_node(trans, path, 0);
1152
1153 EBUG_ON(btree_path_node(path, path->level) &&
1154 !btree_node_locked(path, path->level));
1155
1156 /*
1157 * Note: path->nodes[path->level] may be temporarily NULL here - that
1158 * would indicate to other code that we got to the end of the btree,
1159 * here it indicates that relocking the root failed - it's critical that
1160 * btree_path_lock_root() comes next and that it can't fail
1161 */
1162 while (path->level > depth_want) {
1163 ret = btree_path_node(path, path->level)
1164 ? btree_path_down(trans, path, flags, trace_ip)
1165 : btree_path_lock_root(trans, path, depth_want, trace_ip);
1166 if (unlikely(ret)) {
1167 if (ret == 1) {
1168 /*
1169 * No nodes at this level - got to the end of
1170 * the btree:
1171 */
1172 ret = 0;
1173 goto out;
1174 }
1175
1176 __bch2_btree_path_unlock(trans, path);
1177 path->level = depth_want;
1178 path->l[path->level].b = ERR_PTR(ret);
1179 goto out;
1180 }
1181 }
1182
1183 path->uptodate = BTREE_ITER_UPTODATE;
1184 out:
1185 if (bch2_err_matches(ret, BCH_ERR_transaction_restart) != !!trans->restarted)
1186 panic("ret %s (%i) trans->restarted %s (%i)\n",
1187 bch2_err_str(ret), ret,
1188 bch2_err_str(trans->restarted), trans->restarted);
1189 bch2_btree_path_verify(trans, path);
1190 return ret;
1191 }
1192
btree_path_copy(struct btree_trans * trans,struct btree_path * dst,struct btree_path * src)1193 static inline void btree_path_copy(struct btree_trans *trans, struct btree_path *dst,
1194 struct btree_path *src)
1195 {
1196 unsigned i, offset = offsetof(struct btree_path, pos);
1197
1198 memcpy((void *) dst + offset,
1199 (void *) src + offset,
1200 sizeof(struct btree_path) - offset);
1201
1202 for (i = 0; i < BTREE_MAX_DEPTH; i++) {
1203 unsigned t = btree_node_locked_type(dst, i);
1204
1205 if (t != BTREE_NODE_UNLOCKED)
1206 six_lock_increment(&dst->l[i].b->c.lock, t);
1207 }
1208 }
1209
btree_path_clone(struct btree_trans * trans,btree_path_idx_t src,bool intent)1210 static btree_path_idx_t btree_path_clone(struct btree_trans *trans, btree_path_idx_t src,
1211 bool intent)
1212 {
1213 btree_path_idx_t new = btree_path_alloc(trans, src);
1214 btree_path_copy(trans, trans->paths + new, trans->paths + src);
1215 __btree_path_get(trans->paths + new, intent);
1216 return new;
1217 }
1218
1219 __flatten
__bch2_btree_path_make_mut(struct btree_trans * trans,btree_path_idx_t path,bool intent,unsigned long ip)1220 btree_path_idx_t __bch2_btree_path_make_mut(struct btree_trans *trans,
1221 btree_path_idx_t path, bool intent, unsigned long ip)
1222 {
1223 __btree_path_put(trans->paths + path, intent);
1224 path = btree_path_clone(trans, path, intent);
1225 trans->paths[path].preserve = false;
1226 return path;
1227 }
1228
1229 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)1230 __bch2_btree_path_set_pos(struct btree_trans *trans,
1231 btree_path_idx_t path_idx, struct bpos new_pos,
1232 bool intent, unsigned long ip)
1233 {
1234 int cmp = bpos_cmp(new_pos, trans->paths[path_idx].pos);
1235
1236 bch2_trans_verify_not_in_restart(trans);
1237 EBUG_ON(!trans->paths[path_idx].ref);
1238
1239 path_idx = bch2_btree_path_make_mut(trans, path_idx, intent, ip);
1240
1241 struct btree_path *path = trans->paths + path_idx;
1242 path->pos = new_pos;
1243 trans->paths_sorted = false;
1244
1245 if (unlikely(path->cached)) {
1246 btree_node_unlock(trans, path, 0);
1247 path->l[0].b = ERR_PTR(-BCH_ERR_no_btree_node_up);
1248 btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE);
1249 goto out;
1250 }
1251
1252 unsigned level = btree_path_up_until_good_node(trans, path, cmp);
1253
1254 if (btree_path_node(path, level)) {
1255 struct btree_path_level *l = &path->l[level];
1256
1257 BUG_ON(!btree_node_locked(path, level));
1258 /*
1259 * We might have to skip over many keys, or just a few: try
1260 * advancing the node iterator, and if we have to skip over too
1261 * many keys just reinit it (or if we're rewinding, since that
1262 * is expensive).
1263 */
1264 if (cmp < 0 ||
1265 !btree_path_advance_to_pos(path, l, 8))
1266 bch2_btree_node_iter_init(&l->iter, l->b, &path->pos);
1267
1268 /*
1269 * Iterators to interior nodes should always be pointed at the first non
1270 * whiteout:
1271 */
1272 if (unlikely(level))
1273 bch2_btree_node_iter_peek(&l->iter, l->b);
1274 }
1275
1276 if (unlikely(level != path->level)) {
1277 btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE);
1278 __bch2_btree_path_unlock(trans, path);
1279 }
1280 out:
1281 bch2_btree_path_verify(trans, path);
1282 return path_idx;
1283 }
1284
1285 /* Btree path: main interface: */
1286
have_path_at_pos(struct btree_trans * trans,struct btree_path * path)1287 static struct btree_path *have_path_at_pos(struct btree_trans *trans, struct btree_path *path)
1288 {
1289 struct btree_path *sib;
1290
1291 sib = prev_btree_path(trans, path);
1292 if (sib && !btree_path_cmp(sib, path))
1293 return sib;
1294
1295 sib = next_btree_path(trans, path);
1296 if (sib && !btree_path_cmp(sib, path))
1297 return sib;
1298
1299 return NULL;
1300 }
1301
have_node_at_pos(struct btree_trans * trans,struct btree_path * path)1302 static struct btree_path *have_node_at_pos(struct btree_trans *trans, struct btree_path *path)
1303 {
1304 struct btree_path *sib;
1305
1306 sib = prev_btree_path(trans, path);
1307 if (sib && sib->level == path->level && path_l(sib)->b == path_l(path)->b)
1308 return sib;
1309
1310 sib = next_btree_path(trans, path);
1311 if (sib && sib->level == path->level && path_l(sib)->b == path_l(path)->b)
1312 return sib;
1313
1314 return NULL;
1315 }
1316
__bch2_path_free(struct btree_trans * trans,btree_path_idx_t path)1317 static inline void __bch2_path_free(struct btree_trans *trans, btree_path_idx_t path)
1318 {
1319 __bch2_btree_path_unlock(trans, trans->paths + path);
1320 btree_path_list_remove(trans, trans->paths + path);
1321 __clear_bit(path, trans->paths_allocated);
1322 }
1323
bch2_path_put(struct btree_trans * trans,btree_path_idx_t path_idx,bool intent)1324 void bch2_path_put(struct btree_trans *trans, btree_path_idx_t path_idx, bool intent)
1325 {
1326 struct btree_path *path = trans->paths + path_idx, *dup;
1327
1328 if (!__btree_path_put(path, intent))
1329 return;
1330
1331 dup = path->preserve
1332 ? have_path_at_pos(trans, path)
1333 : have_node_at_pos(trans, path);
1334
1335 if (!dup && !(!path->preserve && !is_btree_node(path, path->level)))
1336 return;
1337
1338 if (path->should_be_locked &&
1339 !trans->restarted &&
1340 (!dup || !bch2_btree_path_relock_norestart(trans, dup)))
1341 return;
1342
1343 if (dup) {
1344 dup->preserve |= path->preserve;
1345 dup->should_be_locked |= path->should_be_locked;
1346 }
1347
1348 __bch2_path_free(trans, path_idx);
1349 }
1350
bch2_path_put_nokeep(struct btree_trans * trans,btree_path_idx_t path,bool intent)1351 static void bch2_path_put_nokeep(struct btree_trans *trans, btree_path_idx_t path,
1352 bool intent)
1353 {
1354 if (!__btree_path_put(trans->paths + path, intent))
1355 return;
1356
1357 __bch2_path_free(trans, path);
1358 }
1359
bch2_trans_restart_error(struct btree_trans * trans,u32 restart_count)1360 void __noreturn bch2_trans_restart_error(struct btree_trans *trans, u32 restart_count)
1361 {
1362 panic("trans->restart_count %u, should be %u, last restarted by %pS\n",
1363 trans->restart_count, restart_count,
1364 (void *) trans->last_begin_ip);
1365 }
1366
bch2_trans_in_restart_error(struct btree_trans * trans)1367 void __noreturn bch2_trans_in_restart_error(struct btree_trans *trans)
1368 {
1369 panic("in transaction restart: %s, last restarted by %pS\n",
1370 bch2_err_str(trans->restarted),
1371 (void *) trans->last_restarted_ip);
1372 }
1373
1374 noinline __cold
bch2_trans_updates_to_text(struct printbuf * buf,struct btree_trans * trans)1375 void bch2_trans_updates_to_text(struct printbuf *buf, struct btree_trans *trans)
1376 {
1377 prt_printf(buf, "transaction updates for %s journal seq %llu",
1378 trans->fn, trans->journal_res.seq);
1379 prt_newline(buf);
1380 printbuf_indent_add(buf, 2);
1381
1382 trans_for_each_update(trans, i) {
1383 struct bkey_s_c old = { &i->old_k, i->old_v };
1384
1385 prt_printf(buf, "update: btree=%s cached=%u %pS",
1386 bch2_btree_id_str(i->btree_id),
1387 i->cached,
1388 (void *) i->ip_allocated);
1389 prt_newline(buf);
1390
1391 prt_printf(buf, " old ");
1392 bch2_bkey_val_to_text(buf, trans->c, old);
1393 prt_newline(buf);
1394
1395 prt_printf(buf, " new ");
1396 bch2_bkey_val_to_text(buf, trans->c, bkey_i_to_s_c(i->k));
1397 prt_newline(buf);
1398 }
1399
1400 for (struct jset_entry *e = trans->journal_entries;
1401 e != btree_trans_journal_entries_top(trans);
1402 e = vstruct_next(e))
1403 bch2_journal_entry_to_text(buf, trans->c, e);
1404
1405 printbuf_indent_sub(buf, 2);
1406 }
1407
1408 noinline __cold
bch2_dump_trans_updates(struct btree_trans * trans)1409 void bch2_dump_trans_updates(struct btree_trans *trans)
1410 {
1411 struct printbuf buf = PRINTBUF;
1412
1413 bch2_trans_updates_to_text(&buf, trans);
1414 bch2_print_string_as_lines(KERN_ERR, buf.buf);
1415 printbuf_exit(&buf);
1416 }
1417
bch2_btree_path_to_text(struct printbuf * out,struct btree_trans * trans,btree_path_idx_t path_idx)1418 static void bch2_btree_path_to_text(struct printbuf *out, struct btree_trans *trans, btree_path_idx_t path_idx)
1419 {
1420 struct btree_path *path = trans->paths + path_idx;
1421
1422 prt_printf(out, "path: idx %2u ref %u:%u %c %c btree=%s l=%u pos ",
1423 path_idx, path->ref, path->intent_ref,
1424 path->preserve ? 'P' : ' ',
1425 path->should_be_locked ? 'S' : ' ',
1426 bch2_btree_id_str(path->btree_id),
1427 path->level);
1428 bch2_bpos_to_text(out, path->pos);
1429
1430 prt_printf(out, " locks %u", path->nodes_locked);
1431 #ifdef TRACK_PATH_ALLOCATED
1432 prt_printf(out, " %pS", (void *) path->ip_allocated);
1433 #endif
1434 prt_newline(out);
1435 }
1436
1437 static noinline __cold
__bch2_trans_paths_to_text(struct printbuf * out,struct btree_trans * trans,bool nosort)1438 void __bch2_trans_paths_to_text(struct printbuf *out, struct btree_trans *trans,
1439 bool nosort)
1440 {
1441 struct trans_for_each_path_inorder_iter iter;
1442
1443 if (!nosort)
1444 btree_trans_sort_paths(trans);
1445
1446 trans_for_each_path_idx_inorder(trans, iter)
1447 bch2_btree_path_to_text(out, trans, iter.path_idx);
1448 }
1449
1450 noinline __cold
bch2_trans_paths_to_text(struct printbuf * out,struct btree_trans * trans)1451 void bch2_trans_paths_to_text(struct printbuf *out, struct btree_trans *trans)
1452 {
1453 __bch2_trans_paths_to_text(out, trans, false);
1454 }
1455
1456 static noinline __cold
__bch2_dump_trans_paths_updates(struct btree_trans * trans,bool nosort)1457 void __bch2_dump_trans_paths_updates(struct btree_trans *trans, bool nosort)
1458 {
1459 struct printbuf buf = PRINTBUF;
1460
1461 __bch2_trans_paths_to_text(&buf, trans, nosort);
1462 bch2_trans_updates_to_text(&buf, trans);
1463
1464 bch2_print_string_as_lines(KERN_ERR, buf.buf);
1465 printbuf_exit(&buf);
1466 }
1467
1468 noinline __cold
bch2_dump_trans_paths_updates(struct btree_trans * trans)1469 void bch2_dump_trans_paths_updates(struct btree_trans *trans)
1470 {
1471 __bch2_dump_trans_paths_updates(trans, false);
1472 }
1473
1474 noinline __cold
bch2_trans_update_max_paths(struct btree_trans * trans)1475 static void bch2_trans_update_max_paths(struct btree_trans *trans)
1476 {
1477 struct btree_transaction_stats *s = btree_trans_stats(trans);
1478 struct printbuf buf = PRINTBUF;
1479 size_t nr = bitmap_weight(trans->paths_allocated, trans->nr_paths);
1480
1481 bch2_trans_paths_to_text(&buf, trans);
1482
1483 if (!buf.allocation_failure) {
1484 mutex_lock(&s->lock);
1485 if (nr > s->nr_max_paths) {
1486 s->nr_max_paths = nr;
1487 swap(s->max_paths_text, buf.buf);
1488 }
1489 mutex_unlock(&s->lock);
1490 }
1491
1492 printbuf_exit(&buf);
1493
1494 trans->nr_paths_max = nr;
1495 }
1496
1497 noinline __cold
__bch2_btree_trans_too_many_iters(struct btree_trans * trans)1498 int __bch2_btree_trans_too_many_iters(struct btree_trans *trans)
1499 {
1500 if (trace_trans_restart_too_many_iters_enabled()) {
1501 struct printbuf buf = PRINTBUF;
1502
1503 bch2_trans_paths_to_text(&buf, trans);
1504 trace_trans_restart_too_many_iters(trans, _THIS_IP_, buf.buf);
1505 printbuf_exit(&buf);
1506 }
1507
1508 count_event(trans->c, trans_restart_too_many_iters);
1509
1510 return btree_trans_restart(trans, BCH_ERR_transaction_restart_too_many_iters);
1511 }
1512
btree_path_overflow(struct btree_trans * trans)1513 static noinline void btree_path_overflow(struct btree_trans *trans)
1514 {
1515 bch2_dump_trans_paths_updates(trans);
1516 bch_err(trans->c, "trans path overflow");
1517 }
1518
btree_paths_realloc(struct btree_trans * trans)1519 static noinline void btree_paths_realloc(struct btree_trans *trans)
1520 {
1521 unsigned nr = trans->nr_paths * 2;
1522
1523 void *p = kzalloc(BITS_TO_LONGS(nr) * sizeof(unsigned long) +
1524 sizeof(struct btree_trans_paths) +
1525 nr * sizeof(struct btree_path) +
1526 nr * sizeof(btree_path_idx_t) + 8 +
1527 nr * sizeof(struct btree_insert_entry), GFP_KERNEL|__GFP_NOFAIL);
1528
1529 unsigned long *paths_allocated = p;
1530 memcpy(paths_allocated, trans->paths_allocated, BITS_TO_LONGS(trans->nr_paths) * sizeof(unsigned long));
1531 p += BITS_TO_LONGS(nr) * sizeof(unsigned long);
1532
1533 p += sizeof(struct btree_trans_paths);
1534 struct btree_path *paths = p;
1535 *trans_paths_nr(paths) = nr;
1536 memcpy(paths, trans->paths, trans->nr_paths * sizeof(struct btree_path));
1537 p += nr * sizeof(struct btree_path);
1538
1539 btree_path_idx_t *sorted = p;
1540 memcpy(sorted, trans->sorted, trans->nr_sorted * sizeof(btree_path_idx_t));
1541 p += nr * sizeof(btree_path_idx_t) + 8;
1542
1543 struct btree_insert_entry *updates = p;
1544 memcpy(updates, trans->updates, trans->nr_paths * sizeof(struct btree_insert_entry));
1545
1546 unsigned long *old = trans->paths_allocated;
1547
1548 rcu_assign_pointer(trans->paths_allocated, paths_allocated);
1549 rcu_assign_pointer(trans->paths, paths);
1550 rcu_assign_pointer(trans->sorted, sorted);
1551 rcu_assign_pointer(trans->updates, updates);
1552
1553 trans->nr_paths = nr;
1554
1555 if (old != trans->_paths_allocated)
1556 kfree_rcu_mightsleep(old);
1557 }
1558
btree_path_alloc(struct btree_trans * trans,btree_path_idx_t pos)1559 static inline btree_path_idx_t btree_path_alloc(struct btree_trans *trans,
1560 btree_path_idx_t pos)
1561 {
1562 btree_path_idx_t idx = find_first_zero_bit(trans->paths_allocated, trans->nr_paths);
1563
1564 if (unlikely(idx == trans->nr_paths)) {
1565 if (trans->nr_paths == BTREE_ITER_MAX) {
1566 btree_path_overflow(trans);
1567 return 0;
1568 }
1569
1570 btree_paths_realloc(trans);
1571 }
1572
1573 /*
1574 * Do this before marking the new path as allocated, since it won't be
1575 * initialized yet:
1576 */
1577 if (unlikely(idx > trans->nr_paths_max))
1578 bch2_trans_update_max_paths(trans);
1579
1580 __set_bit(idx, trans->paths_allocated);
1581
1582 struct btree_path *path = &trans->paths[idx];
1583 path->ref = 0;
1584 path->intent_ref = 0;
1585 path->nodes_locked = 0;
1586
1587 btree_path_list_add(trans, pos, idx);
1588 trans->paths_sorted = false;
1589 return idx;
1590 }
1591
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)1592 btree_path_idx_t bch2_path_get(struct btree_trans *trans,
1593 enum btree_id btree_id, struct bpos pos,
1594 unsigned locks_want, unsigned level,
1595 unsigned flags, unsigned long ip)
1596 {
1597 struct btree_path *path;
1598 bool cached = flags & BTREE_ITER_CACHED;
1599 bool intent = flags & BTREE_ITER_INTENT;
1600 struct trans_for_each_path_inorder_iter iter;
1601 btree_path_idx_t path_pos = 0, path_idx;
1602
1603 bch2_trans_verify_not_in_restart(trans);
1604 bch2_trans_verify_locks(trans);
1605
1606 btree_trans_sort_paths(trans);
1607
1608 trans_for_each_path_inorder(trans, path, iter) {
1609 if (__btree_path_cmp(path,
1610 btree_id,
1611 cached,
1612 pos,
1613 level) > 0)
1614 break;
1615
1616 path_pos = iter.path_idx;
1617 }
1618
1619 if (path_pos &&
1620 trans->paths[path_pos].cached == cached &&
1621 trans->paths[path_pos].btree_id == btree_id &&
1622 trans->paths[path_pos].level == level) {
1623 __btree_path_get(trans->paths + path_pos, intent);
1624 path_idx = bch2_btree_path_set_pos(trans, path_pos, pos, intent, ip);
1625 path = trans->paths + path_idx;
1626 } else {
1627 path_idx = btree_path_alloc(trans, path_pos);
1628 path = trans->paths + path_idx;
1629
1630 __btree_path_get(path, intent);
1631 path->pos = pos;
1632 path->btree_id = btree_id;
1633 path->cached = cached;
1634 path->uptodate = BTREE_ITER_NEED_TRAVERSE;
1635 path->should_be_locked = false;
1636 path->level = level;
1637 path->locks_want = locks_want;
1638 path->nodes_locked = 0;
1639 for (unsigned i = 0; i < ARRAY_SIZE(path->l); i++)
1640 path->l[i].b = ERR_PTR(-BCH_ERR_no_btree_node_init);
1641 #ifdef TRACK_PATH_ALLOCATED
1642 path->ip_allocated = ip;
1643 #endif
1644 trans->paths_sorted = false;
1645 }
1646
1647 if (!(flags & BTREE_ITER_NOPRESERVE))
1648 path->preserve = true;
1649
1650 if (path->intent_ref)
1651 locks_want = max(locks_want, level + 1);
1652
1653 /*
1654 * If the path has locks_want greater than requested, we don't downgrade
1655 * it here - on transaction restart because btree node split needs to
1656 * upgrade locks, we might be putting/getting the iterator again.
1657 * Downgrading iterators only happens via bch2_trans_downgrade(), after
1658 * a successful transaction commit.
1659 */
1660
1661 locks_want = min(locks_want, BTREE_MAX_DEPTH);
1662 if (locks_want > path->locks_want)
1663 bch2_btree_path_upgrade_noupgrade_sibs(trans, path, locks_want, NULL);
1664
1665 return path_idx;
1666 }
1667
bch2_btree_path_peek_slot(struct btree_path * path,struct bkey * u)1668 struct bkey_s_c bch2_btree_path_peek_slot(struct btree_path *path, struct bkey *u)
1669 {
1670
1671 struct btree_path_level *l = path_l(path);
1672 struct bkey_packed *_k;
1673 struct bkey_s_c k;
1674
1675 if (unlikely(!l->b))
1676 return bkey_s_c_null;
1677
1678 EBUG_ON(path->uptodate != BTREE_ITER_UPTODATE);
1679 EBUG_ON(!btree_node_locked(path, path->level));
1680
1681 if (!path->cached) {
1682 _k = bch2_btree_node_iter_peek_all(&l->iter, l->b);
1683 k = _k ? bkey_disassemble(l->b, _k, u) : bkey_s_c_null;
1684
1685 EBUG_ON(k.k && bkey_deleted(k.k) && bpos_eq(k.k->p, path->pos));
1686
1687 if (!k.k || !bpos_eq(path->pos, k.k->p))
1688 goto hole;
1689 } else {
1690 struct bkey_cached *ck = (void *) path->l[0].b;
1691
1692 EBUG_ON(ck &&
1693 (path->btree_id != ck->key.btree_id ||
1694 !bkey_eq(path->pos, ck->key.pos)));
1695 if (!ck || !ck->valid)
1696 return bkey_s_c_null;
1697
1698 *u = ck->k->k;
1699 k = bkey_i_to_s_c(ck->k);
1700 }
1701
1702 return k;
1703 hole:
1704 bkey_init(u);
1705 u->p = path->pos;
1706 return (struct bkey_s_c) { u, NULL };
1707 }
1708
1709 /* Btree iterators: */
1710
1711 int __must_check
__bch2_btree_iter_traverse(struct btree_iter * iter)1712 __bch2_btree_iter_traverse(struct btree_iter *iter)
1713 {
1714 return bch2_btree_path_traverse(iter->trans, iter->path, iter->flags);
1715 }
1716
1717 int __must_check
bch2_btree_iter_traverse(struct btree_iter * iter)1718 bch2_btree_iter_traverse(struct btree_iter *iter)
1719 {
1720 struct btree_trans *trans = iter->trans;
1721 int ret;
1722
1723 iter->path = bch2_btree_path_set_pos(trans, iter->path,
1724 btree_iter_search_key(iter),
1725 iter->flags & BTREE_ITER_INTENT,
1726 btree_iter_ip_allocated(iter));
1727
1728 ret = bch2_btree_path_traverse(iter->trans, iter->path, iter->flags);
1729 if (ret)
1730 return ret;
1731
1732 btree_path_set_should_be_locked(trans->paths + iter->path);
1733 return 0;
1734 }
1735
1736 /* Iterate across nodes (leaf and interior nodes) */
1737
bch2_btree_iter_peek_node(struct btree_iter * iter)1738 struct btree *bch2_btree_iter_peek_node(struct btree_iter *iter)
1739 {
1740 struct btree_trans *trans = iter->trans;
1741 struct btree *b = NULL;
1742 int ret;
1743
1744 EBUG_ON(trans->paths[iter->path].cached);
1745 bch2_btree_iter_verify(iter);
1746
1747 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
1748 if (ret)
1749 goto err;
1750
1751 struct btree_path *path = btree_iter_path(trans, iter);
1752 b = btree_path_node(path, path->level);
1753 if (!b)
1754 goto out;
1755
1756 BUG_ON(bpos_lt(b->key.k.p, iter->pos));
1757
1758 bkey_init(&iter->k);
1759 iter->k.p = iter->pos = b->key.k.p;
1760
1761 iter->path = bch2_btree_path_set_pos(trans, iter->path, b->key.k.p,
1762 iter->flags & BTREE_ITER_INTENT,
1763 btree_iter_ip_allocated(iter));
1764 btree_path_set_should_be_locked(btree_iter_path(trans, iter));
1765 out:
1766 bch2_btree_iter_verify_entry_exit(iter);
1767 bch2_btree_iter_verify(iter);
1768
1769 return b;
1770 err:
1771 b = ERR_PTR(ret);
1772 goto out;
1773 }
1774
bch2_btree_iter_peek_node_and_restart(struct btree_iter * iter)1775 struct btree *bch2_btree_iter_peek_node_and_restart(struct btree_iter *iter)
1776 {
1777 struct btree *b;
1778
1779 while (b = bch2_btree_iter_peek_node(iter),
1780 bch2_err_matches(PTR_ERR_OR_ZERO(b), BCH_ERR_transaction_restart))
1781 bch2_trans_begin(iter->trans);
1782
1783 return b;
1784 }
1785
bch2_btree_iter_next_node(struct btree_iter * iter)1786 struct btree *bch2_btree_iter_next_node(struct btree_iter *iter)
1787 {
1788 struct btree_trans *trans = iter->trans;
1789 struct btree *b = NULL;
1790 int ret;
1791
1792 EBUG_ON(trans->paths[iter->path].cached);
1793 bch2_trans_verify_not_in_restart(trans);
1794 bch2_btree_iter_verify(iter);
1795
1796 struct btree_path *path = btree_iter_path(trans, iter);
1797
1798 /* already at end? */
1799 if (!btree_path_node(path, path->level))
1800 return NULL;
1801
1802 /* got to end? */
1803 if (!btree_path_node(path, path->level + 1)) {
1804 btree_path_set_level_up(trans, path);
1805 return NULL;
1806 }
1807
1808 if (!bch2_btree_node_relock(trans, path, path->level + 1)) {
1809 __bch2_btree_path_unlock(trans, path);
1810 path->l[path->level].b = ERR_PTR(-BCH_ERR_no_btree_node_relock);
1811 path->l[path->level + 1].b = ERR_PTR(-BCH_ERR_no_btree_node_relock);
1812 btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE);
1813 trace_and_count(trans->c, trans_restart_relock_next_node, trans, _THIS_IP_, path);
1814 ret = btree_trans_restart(trans, BCH_ERR_transaction_restart_relock);
1815 goto err;
1816 }
1817
1818 b = btree_path_node(path, path->level + 1);
1819
1820 if (bpos_eq(iter->pos, b->key.k.p)) {
1821 __btree_path_set_level_up(trans, path, path->level++);
1822 } else {
1823 /*
1824 * Haven't gotten to the end of the parent node: go back down to
1825 * the next child node
1826 */
1827 iter->path = bch2_btree_path_set_pos(trans, iter->path,
1828 bpos_successor(iter->pos),
1829 iter->flags & BTREE_ITER_INTENT,
1830 btree_iter_ip_allocated(iter));
1831
1832 path = btree_iter_path(trans, iter);
1833 btree_path_set_level_down(trans, path, iter->min_depth);
1834
1835 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
1836 if (ret)
1837 goto err;
1838
1839 path = btree_iter_path(trans, iter);
1840 b = path->l[path->level].b;
1841 }
1842
1843 bkey_init(&iter->k);
1844 iter->k.p = iter->pos = b->key.k.p;
1845
1846 iter->path = bch2_btree_path_set_pos(trans, iter->path, b->key.k.p,
1847 iter->flags & BTREE_ITER_INTENT,
1848 btree_iter_ip_allocated(iter));
1849 btree_path_set_should_be_locked(btree_iter_path(trans, iter));
1850 EBUG_ON(btree_iter_path(trans, iter)->uptodate);
1851 out:
1852 bch2_btree_iter_verify_entry_exit(iter);
1853 bch2_btree_iter_verify(iter);
1854
1855 return b;
1856 err:
1857 b = ERR_PTR(ret);
1858 goto out;
1859 }
1860
1861 /* Iterate across keys (in leaf nodes only) */
1862
bch2_btree_iter_advance(struct btree_iter * iter)1863 inline bool bch2_btree_iter_advance(struct btree_iter *iter)
1864 {
1865 struct bpos pos = iter->k.p;
1866 bool ret = !(iter->flags & BTREE_ITER_ALL_SNAPSHOTS
1867 ? bpos_eq(pos, SPOS_MAX)
1868 : bkey_eq(pos, SPOS_MAX));
1869
1870 if (ret && !(iter->flags & BTREE_ITER_IS_EXTENTS))
1871 pos = bkey_successor(iter, pos);
1872 bch2_btree_iter_set_pos(iter, pos);
1873 return ret;
1874 }
1875
bch2_btree_iter_rewind(struct btree_iter * iter)1876 inline bool bch2_btree_iter_rewind(struct btree_iter *iter)
1877 {
1878 struct bpos pos = bkey_start_pos(&iter->k);
1879 bool ret = !(iter->flags & BTREE_ITER_ALL_SNAPSHOTS
1880 ? bpos_eq(pos, POS_MIN)
1881 : bkey_eq(pos, POS_MIN));
1882
1883 if (ret && !(iter->flags & BTREE_ITER_IS_EXTENTS))
1884 pos = bkey_predecessor(iter, pos);
1885 bch2_btree_iter_set_pos(iter, pos);
1886 return ret;
1887 }
1888
1889 static noinline
bch2_btree_trans_peek_prev_updates(struct btree_trans * trans,struct btree_iter * iter,struct bkey_s_c * k)1890 void bch2_btree_trans_peek_prev_updates(struct btree_trans *trans, struct btree_iter *iter,
1891 struct bkey_s_c *k)
1892 {
1893 struct bpos end = path_l(btree_iter_path(trans, iter))->b->data->min_key;
1894
1895 trans_for_each_update(trans, i)
1896 if (!i->key_cache_already_flushed &&
1897 i->btree_id == iter->btree_id &&
1898 bpos_le(i->k->k.p, iter->pos) &&
1899 bpos_ge(i->k->k.p, k->k ? k->k->p : end)) {
1900 iter->k = i->k->k;
1901 *k = bkey_i_to_s_c(i->k);
1902 }
1903 }
1904
1905 static noinline
bch2_btree_trans_peek_updates(struct btree_trans * trans,struct btree_iter * iter,struct bkey_s_c * k)1906 void bch2_btree_trans_peek_updates(struct btree_trans *trans, struct btree_iter *iter,
1907 struct bkey_s_c *k)
1908 {
1909 struct btree_path *path = btree_iter_path(trans, iter);
1910 struct bpos end = path_l(path)->b->key.k.p;
1911
1912 trans_for_each_update(trans, i)
1913 if (!i->key_cache_already_flushed &&
1914 i->btree_id == iter->btree_id &&
1915 bpos_ge(i->k->k.p, path->pos) &&
1916 bpos_le(i->k->k.p, k->k ? k->k->p : end)) {
1917 iter->k = i->k->k;
1918 *k = bkey_i_to_s_c(i->k);
1919 }
1920 }
1921
1922 static noinline
bch2_btree_trans_peek_slot_updates(struct btree_trans * trans,struct btree_iter * iter,struct bkey_s_c * k)1923 void bch2_btree_trans_peek_slot_updates(struct btree_trans *trans, struct btree_iter *iter,
1924 struct bkey_s_c *k)
1925 {
1926 trans_for_each_update(trans, i)
1927 if (!i->key_cache_already_flushed &&
1928 i->btree_id == iter->btree_id &&
1929 bpos_eq(i->k->k.p, iter->pos)) {
1930 iter->k = i->k->k;
1931 *k = bkey_i_to_s_c(i->k);
1932 }
1933 }
1934
bch2_btree_journal_peek(struct btree_trans * trans,struct btree_iter * iter,struct bpos end_pos)1935 static struct bkey_i *bch2_btree_journal_peek(struct btree_trans *trans,
1936 struct btree_iter *iter,
1937 struct bpos end_pos)
1938 {
1939 struct btree_path *path = btree_iter_path(trans, iter);
1940
1941 return bch2_journal_keys_peek_upto(trans->c, iter->btree_id,
1942 path->level,
1943 path->pos,
1944 end_pos,
1945 &iter->journal_idx);
1946 }
1947
1948 static noinline
btree_trans_peek_slot_journal(struct btree_trans * trans,struct btree_iter * iter)1949 struct bkey_s_c btree_trans_peek_slot_journal(struct btree_trans *trans,
1950 struct btree_iter *iter)
1951 {
1952 struct btree_path *path = btree_iter_path(trans, iter);
1953 struct bkey_i *k = bch2_btree_journal_peek(trans, iter, path->pos);
1954
1955 if (k) {
1956 iter->k = k->k;
1957 return bkey_i_to_s_c(k);
1958 } else {
1959 return bkey_s_c_null;
1960 }
1961 }
1962
1963 static noinline
btree_trans_peek_journal(struct btree_trans * trans,struct btree_iter * iter,struct bkey_s_c k)1964 struct bkey_s_c btree_trans_peek_journal(struct btree_trans *trans,
1965 struct btree_iter *iter,
1966 struct bkey_s_c k)
1967 {
1968 struct btree_path *path = btree_iter_path(trans, iter);
1969 struct bkey_i *next_journal =
1970 bch2_btree_journal_peek(trans, iter,
1971 k.k ? k.k->p : path_l(path)->b->key.k.p);
1972
1973 if (next_journal) {
1974 iter->k = next_journal->k;
1975 k = bkey_i_to_s_c(next_journal);
1976 }
1977
1978 return k;
1979 }
1980
1981 /*
1982 * Checks btree key cache for key at iter->pos and returns it if present, or
1983 * bkey_s_c_null:
1984 */
1985 static noinline
btree_trans_peek_key_cache(struct btree_iter * iter,struct bpos pos)1986 struct bkey_s_c btree_trans_peek_key_cache(struct btree_iter *iter, struct bpos pos)
1987 {
1988 struct btree_trans *trans = iter->trans;
1989 struct bch_fs *c = trans->c;
1990 struct bkey u;
1991 struct bkey_s_c k;
1992 int ret;
1993
1994 if ((iter->flags & BTREE_ITER_KEY_CACHE_FILL) &&
1995 bpos_eq(iter->pos, pos))
1996 return bkey_s_c_null;
1997
1998 if (!bch2_btree_key_cache_find(c, iter->btree_id, pos))
1999 return bkey_s_c_null;
2000
2001 if (!iter->key_cache_path)
2002 iter->key_cache_path = bch2_path_get(trans, iter->btree_id, pos,
2003 iter->flags & BTREE_ITER_INTENT, 0,
2004 iter->flags|BTREE_ITER_CACHED|
2005 BTREE_ITER_CACHED_NOFILL,
2006 _THIS_IP_);
2007
2008 iter->key_cache_path = bch2_btree_path_set_pos(trans, iter->key_cache_path, pos,
2009 iter->flags & BTREE_ITER_INTENT,
2010 btree_iter_ip_allocated(iter));
2011
2012 ret = bch2_btree_path_traverse(trans, iter->key_cache_path,
2013 iter->flags|BTREE_ITER_CACHED) ?:
2014 bch2_btree_path_relock(trans, btree_iter_path(trans, iter), _THIS_IP_);
2015 if (unlikely(ret))
2016 return bkey_s_c_err(ret);
2017
2018 btree_path_set_should_be_locked(trans->paths + iter->key_cache_path);
2019
2020 k = bch2_btree_path_peek_slot(trans->paths + iter->key_cache_path, &u);
2021 if (k.k && !bkey_err(k)) {
2022 iter->k = u;
2023 k.k = &iter->k;
2024 }
2025 return k;
2026 }
2027
__bch2_btree_iter_peek(struct btree_iter * iter,struct bpos search_key)2028 static struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter, struct bpos search_key)
2029 {
2030 struct btree_trans *trans = iter->trans;
2031 struct bkey_s_c k, k2;
2032 int ret;
2033
2034 EBUG_ON(btree_iter_path(trans, iter)->cached);
2035 bch2_btree_iter_verify(iter);
2036
2037 while (1) {
2038 struct btree_path_level *l;
2039
2040 iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key,
2041 iter->flags & BTREE_ITER_INTENT,
2042 btree_iter_ip_allocated(iter));
2043
2044 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
2045 if (unlikely(ret)) {
2046 /* ensure that iter->k is consistent with iter->pos: */
2047 bch2_btree_iter_set_pos(iter, iter->pos);
2048 k = bkey_s_c_err(ret);
2049 goto out;
2050 }
2051
2052 struct btree_path *path = btree_iter_path(trans, iter);
2053 l = path_l(path);
2054
2055 if (unlikely(!l->b)) {
2056 /* No btree nodes at requested level: */
2057 bch2_btree_iter_set_pos(iter, SPOS_MAX);
2058 k = bkey_s_c_null;
2059 goto out;
2060 }
2061
2062 btree_path_set_should_be_locked(path);
2063
2064 k = btree_path_level_peek_all(trans->c, l, &iter->k);
2065
2066 if (unlikely(iter->flags & BTREE_ITER_WITH_KEY_CACHE) &&
2067 k.k &&
2068 (k2 = btree_trans_peek_key_cache(iter, k.k->p)).k) {
2069 k = k2;
2070 ret = bkey_err(k);
2071 if (ret) {
2072 bch2_btree_iter_set_pos(iter, iter->pos);
2073 goto out;
2074 }
2075 }
2076
2077 if (unlikely(iter->flags & BTREE_ITER_WITH_JOURNAL))
2078 k = btree_trans_peek_journal(trans, iter, k);
2079
2080 if (unlikely((iter->flags & BTREE_ITER_WITH_UPDATES) &&
2081 trans->nr_updates))
2082 bch2_btree_trans_peek_updates(trans, iter, &k);
2083
2084 if (k.k && bkey_deleted(k.k)) {
2085 /*
2086 * If we've got a whiteout, and it's after the search
2087 * key, advance the search key to the whiteout instead
2088 * of just after the whiteout - it might be a btree
2089 * whiteout, with a real key at the same position, since
2090 * in the btree deleted keys sort before non deleted.
2091 */
2092 search_key = !bpos_eq(search_key, k.k->p)
2093 ? k.k->p
2094 : bpos_successor(k.k->p);
2095 continue;
2096 }
2097
2098 if (likely(k.k)) {
2099 break;
2100 } else if (likely(!bpos_eq(l->b->key.k.p, SPOS_MAX))) {
2101 /* Advance to next leaf node: */
2102 search_key = bpos_successor(l->b->key.k.p);
2103 } else {
2104 /* End of btree: */
2105 bch2_btree_iter_set_pos(iter, SPOS_MAX);
2106 k = bkey_s_c_null;
2107 goto out;
2108 }
2109 }
2110 out:
2111 bch2_btree_iter_verify(iter);
2112
2113 return k;
2114 }
2115
2116 /**
2117 * bch2_btree_iter_peek_upto() - returns first key greater than or equal to
2118 * iterator's current position
2119 * @iter: iterator to peek from
2120 * @end: search limit: returns keys less than or equal to @end
2121 *
2122 * Returns: key if found, or an error extractable with bkey_err().
2123 */
bch2_btree_iter_peek_upto(struct btree_iter * iter,struct bpos end)2124 struct bkey_s_c bch2_btree_iter_peek_upto(struct btree_iter *iter, struct bpos end)
2125 {
2126 struct btree_trans *trans = iter->trans;
2127 struct bpos search_key = btree_iter_search_key(iter);
2128 struct bkey_s_c k;
2129 struct bpos iter_pos;
2130 int ret;
2131
2132 EBUG_ON((iter->flags & BTREE_ITER_FILTER_SNAPSHOTS) && bkey_eq(end, POS_MAX));
2133
2134 if (iter->update_path) {
2135 bch2_path_put_nokeep(trans, iter->update_path,
2136 iter->flags & BTREE_ITER_INTENT);
2137 iter->update_path = 0;
2138 }
2139
2140 bch2_btree_iter_verify_entry_exit(iter);
2141
2142 while (1) {
2143 k = __bch2_btree_iter_peek(iter, search_key);
2144 if (unlikely(!k.k))
2145 goto end;
2146 if (unlikely(bkey_err(k)))
2147 goto out_no_locked;
2148
2149 /*
2150 * We need to check against @end before FILTER_SNAPSHOTS because
2151 * if we get to a different inode that requested we might be
2152 * seeing keys for a different snapshot tree that will all be
2153 * filtered out.
2154 *
2155 * But we can't do the full check here, because bkey_start_pos()
2156 * isn't monotonically increasing before FILTER_SNAPSHOTS, and
2157 * that's what we check against in extents mode:
2158 */
2159 if (unlikely(!(iter->flags & BTREE_ITER_IS_EXTENTS)
2160 ? bkey_gt(k.k->p, end)
2161 : k.k->p.inode > end.inode))
2162 goto end;
2163
2164 if (iter->update_path &&
2165 !bkey_eq(trans->paths[iter->update_path].pos, k.k->p)) {
2166 bch2_path_put_nokeep(trans, iter->update_path,
2167 iter->flags & BTREE_ITER_INTENT);
2168 iter->update_path = 0;
2169 }
2170
2171 if ((iter->flags & BTREE_ITER_FILTER_SNAPSHOTS) &&
2172 (iter->flags & BTREE_ITER_INTENT) &&
2173 !(iter->flags & BTREE_ITER_IS_EXTENTS) &&
2174 !iter->update_path) {
2175 struct bpos pos = k.k->p;
2176
2177 if (pos.snapshot < iter->snapshot) {
2178 search_key = bpos_successor(k.k->p);
2179 continue;
2180 }
2181
2182 pos.snapshot = iter->snapshot;
2183
2184 /*
2185 * advance, same as on exit for iter->path, but only up
2186 * to snapshot
2187 */
2188 __btree_path_get(trans->paths + iter->path, iter->flags & BTREE_ITER_INTENT);
2189 iter->update_path = iter->path;
2190
2191 iter->update_path = bch2_btree_path_set_pos(trans,
2192 iter->update_path, pos,
2193 iter->flags & BTREE_ITER_INTENT,
2194 _THIS_IP_);
2195 ret = bch2_btree_path_traverse(trans, iter->update_path, iter->flags);
2196 if (unlikely(ret)) {
2197 k = bkey_s_c_err(ret);
2198 goto out_no_locked;
2199 }
2200 }
2201
2202 /*
2203 * We can never have a key in a leaf node at POS_MAX, so
2204 * we don't have to check these successor() calls:
2205 */
2206 if ((iter->flags & BTREE_ITER_FILTER_SNAPSHOTS) &&
2207 !bch2_snapshot_is_ancestor(trans->c,
2208 iter->snapshot,
2209 k.k->p.snapshot)) {
2210 search_key = bpos_successor(k.k->p);
2211 continue;
2212 }
2213
2214 if (bkey_whiteout(k.k) &&
2215 !(iter->flags & BTREE_ITER_ALL_SNAPSHOTS)) {
2216 search_key = bkey_successor(iter, k.k->p);
2217 continue;
2218 }
2219
2220 /*
2221 * iter->pos should be mononotically increasing, and always be
2222 * equal to the key we just returned - except extents can
2223 * straddle iter->pos:
2224 */
2225 if (!(iter->flags & BTREE_ITER_IS_EXTENTS))
2226 iter_pos = k.k->p;
2227 else
2228 iter_pos = bkey_max(iter->pos, bkey_start_pos(k.k));
2229
2230 if (unlikely(!(iter->flags & BTREE_ITER_IS_EXTENTS)
2231 ? bkey_gt(iter_pos, end)
2232 : bkey_ge(iter_pos, end)))
2233 goto end;
2234
2235 break;
2236 }
2237
2238 iter->pos = iter_pos;
2239
2240 iter->path = bch2_btree_path_set_pos(trans, iter->path, k.k->p,
2241 iter->flags & BTREE_ITER_INTENT,
2242 btree_iter_ip_allocated(iter));
2243
2244 btree_path_set_should_be_locked(btree_iter_path(trans, iter));
2245 out_no_locked:
2246 if (iter->update_path) {
2247 ret = bch2_btree_path_relock(trans, trans->paths + iter->update_path, _THIS_IP_);
2248 if (unlikely(ret))
2249 k = bkey_s_c_err(ret);
2250 else
2251 btree_path_set_should_be_locked(trans->paths + iter->update_path);
2252 }
2253
2254 if (!(iter->flags & BTREE_ITER_ALL_SNAPSHOTS))
2255 iter->pos.snapshot = iter->snapshot;
2256
2257 ret = bch2_btree_iter_verify_ret(iter, k);
2258 if (unlikely(ret)) {
2259 bch2_btree_iter_set_pos(iter, iter->pos);
2260 k = bkey_s_c_err(ret);
2261 }
2262
2263 bch2_btree_iter_verify_entry_exit(iter);
2264
2265 return k;
2266 end:
2267 bch2_btree_iter_set_pos(iter, end);
2268 k = bkey_s_c_null;
2269 goto out_no_locked;
2270 }
2271
2272 /**
2273 * bch2_btree_iter_next() - returns first key greater than iterator's current
2274 * position
2275 * @iter: iterator to peek from
2276 *
2277 * Returns: key if found, or an error extractable with bkey_err().
2278 */
bch2_btree_iter_next(struct btree_iter * iter)2279 struct bkey_s_c bch2_btree_iter_next(struct btree_iter *iter)
2280 {
2281 if (!bch2_btree_iter_advance(iter))
2282 return bkey_s_c_null;
2283
2284 return bch2_btree_iter_peek(iter);
2285 }
2286
2287 /**
2288 * bch2_btree_iter_peek_prev() - returns first key less than or equal to
2289 * iterator's current position
2290 * @iter: iterator to peek from
2291 *
2292 * Returns: key if found, or an error extractable with bkey_err().
2293 */
bch2_btree_iter_peek_prev(struct btree_iter * iter)2294 struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *iter)
2295 {
2296 struct btree_trans *trans = iter->trans;
2297 struct bpos search_key = iter->pos;
2298 struct bkey_s_c k;
2299 struct bkey saved_k;
2300 const struct bch_val *saved_v;
2301 btree_path_idx_t saved_path = 0;
2302 int ret;
2303
2304 EBUG_ON(btree_iter_path(trans, iter)->cached ||
2305 btree_iter_path(trans, iter)->level);
2306
2307 if (iter->flags & BTREE_ITER_WITH_JOURNAL)
2308 return bkey_s_c_err(-EIO);
2309
2310 bch2_btree_iter_verify(iter);
2311 bch2_btree_iter_verify_entry_exit(iter);
2312
2313 if (iter->flags & BTREE_ITER_FILTER_SNAPSHOTS)
2314 search_key.snapshot = U32_MAX;
2315
2316 while (1) {
2317 iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key,
2318 iter->flags & BTREE_ITER_INTENT,
2319 btree_iter_ip_allocated(iter));
2320
2321 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
2322 if (unlikely(ret)) {
2323 /* ensure that iter->k is consistent with iter->pos: */
2324 bch2_btree_iter_set_pos(iter, iter->pos);
2325 k = bkey_s_c_err(ret);
2326 goto out_no_locked;
2327 }
2328
2329 struct btree_path *path = btree_iter_path(trans, iter);
2330
2331 k = btree_path_level_peek(trans, path, &path->l[0], &iter->k);
2332 if (!k.k ||
2333 ((iter->flags & BTREE_ITER_IS_EXTENTS)
2334 ? bpos_ge(bkey_start_pos(k.k), search_key)
2335 : bpos_gt(k.k->p, search_key)))
2336 k = btree_path_level_prev(trans, path, &path->l[0], &iter->k);
2337
2338 if (unlikely((iter->flags & BTREE_ITER_WITH_UPDATES) &&
2339 trans->nr_updates))
2340 bch2_btree_trans_peek_prev_updates(trans, iter, &k);
2341
2342 if (likely(k.k)) {
2343 if (iter->flags & BTREE_ITER_FILTER_SNAPSHOTS) {
2344 if (k.k->p.snapshot == iter->snapshot)
2345 goto got_key;
2346
2347 /*
2348 * If we have a saved candidate, and we're no
2349 * longer at the same _key_ (not pos), return
2350 * that candidate
2351 */
2352 if (saved_path && !bkey_eq(k.k->p, saved_k.p)) {
2353 bch2_path_put_nokeep(trans, iter->path,
2354 iter->flags & BTREE_ITER_INTENT);
2355 iter->path = saved_path;
2356 saved_path = 0;
2357 iter->k = saved_k;
2358 k.v = saved_v;
2359 goto got_key;
2360 }
2361
2362 if (bch2_snapshot_is_ancestor(trans->c,
2363 iter->snapshot,
2364 k.k->p.snapshot)) {
2365 if (saved_path)
2366 bch2_path_put_nokeep(trans, saved_path,
2367 iter->flags & BTREE_ITER_INTENT);
2368 saved_path = btree_path_clone(trans, iter->path,
2369 iter->flags & BTREE_ITER_INTENT);
2370 path = btree_iter_path(trans, iter);
2371 saved_k = *k.k;
2372 saved_v = k.v;
2373 }
2374
2375 search_key = bpos_predecessor(k.k->p);
2376 continue;
2377 }
2378 got_key:
2379 if (bkey_whiteout(k.k) &&
2380 !(iter->flags & BTREE_ITER_ALL_SNAPSHOTS)) {
2381 search_key = bkey_predecessor(iter, k.k->p);
2382 if (iter->flags & BTREE_ITER_FILTER_SNAPSHOTS)
2383 search_key.snapshot = U32_MAX;
2384 continue;
2385 }
2386
2387 btree_path_set_should_be_locked(path);
2388 break;
2389 } else if (likely(!bpos_eq(path->l[0].b->data->min_key, POS_MIN))) {
2390 /* Advance to previous leaf node: */
2391 search_key = bpos_predecessor(path->l[0].b->data->min_key);
2392 } else {
2393 /* Start of btree: */
2394 bch2_btree_iter_set_pos(iter, POS_MIN);
2395 k = bkey_s_c_null;
2396 goto out_no_locked;
2397 }
2398 }
2399
2400 EBUG_ON(bkey_gt(bkey_start_pos(k.k), iter->pos));
2401
2402 /* Extents can straddle iter->pos: */
2403 if (bkey_lt(k.k->p, iter->pos))
2404 iter->pos = k.k->p;
2405
2406 if (iter->flags & BTREE_ITER_FILTER_SNAPSHOTS)
2407 iter->pos.snapshot = iter->snapshot;
2408 out_no_locked:
2409 if (saved_path)
2410 bch2_path_put_nokeep(trans, saved_path, iter->flags & BTREE_ITER_INTENT);
2411
2412 bch2_btree_iter_verify_entry_exit(iter);
2413 bch2_btree_iter_verify(iter);
2414
2415 return k;
2416 }
2417
2418 /**
2419 * bch2_btree_iter_prev() - returns first key less than iterator's current
2420 * position
2421 * @iter: iterator to peek from
2422 *
2423 * Returns: key if found, or an error extractable with bkey_err().
2424 */
bch2_btree_iter_prev(struct btree_iter * iter)2425 struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *iter)
2426 {
2427 if (!bch2_btree_iter_rewind(iter))
2428 return bkey_s_c_null;
2429
2430 return bch2_btree_iter_peek_prev(iter);
2431 }
2432
bch2_btree_iter_peek_slot(struct btree_iter * iter)2433 struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *iter)
2434 {
2435 struct btree_trans *trans = iter->trans;
2436 struct bpos search_key;
2437 struct bkey_s_c k;
2438 int ret;
2439
2440 bch2_btree_iter_verify(iter);
2441 bch2_btree_iter_verify_entry_exit(iter);
2442 EBUG_ON(btree_iter_path(trans, iter)->level && (iter->flags & BTREE_ITER_WITH_KEY_CACHE));
2443
2444 /* extents can't span inode numbers: */
2445 if ((iter->flags & BTREE_ITER_IS_EXTENTS) &&
2446 unlikely(iter->pos.offset == KEY_OFFSET_MAX)) {
2447 if (iter->pos.inode == KEY_INODE_MAX)
2448 return bkey_s_c_null;
2449
2450 bch2_btree_iter_set_pos(iter, bpos_nosnap_successor(iter->pos));
2451 }
2452
2453 search_key = btree_iter_search_key(iter);
2454 iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key,
2455 iter->flags & BTREE_ITER_INTENT,
2456 btree_iter_ip_allocated(iter));
2457
2458 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags);
2459 if (unlikely(ret)) {
2460 k = bkey_s_c_err(ret);
2461 goto out_no_locked;
2462 }
2463
2464 if ((iter->flags & BTREE_ITER_CACHED) ||
2465 !(iter->flags & (BTREE_ITER_IS_EXTENTS|BTREE_ITER_FILTER_SNAPSHOTS))) {
2466 k = bkey_s_c_null;
2467
2468 if (unlikely((iter->flags & BTREE_ITER_WITH_UPDATES) &&
2469 trans->nr_updates)) {
2470 bch2_btree_trans_peek_slot_updates(trans, iter, &k);
2471 if (k.k)
2472 goto out;
2473 }
2474
2475 if (unlikely(iter->flags & BTREE_ITER_WITH_JOURNAL) &&
2476 (k = btree_trans_peek_slot_journal(trans, iter)).k)
2477 goto out;
2478
2479 if (unlikely(iter->flags & BTREE_ITER_WITH_KEY_CACHE) &&
2480 (k = btree_trans_peek_key_cache(iter, iter->pos)).k) {
2481 if (!bkey_err(k))
2482 iter->k = *k.k;
2483 /* We're not returning a key from iter->path: */
2484 goto out_no_locked;
2485 }
2486
2487 k = bch2_btree_path_peek_slot(trans->paths + iter->path, &iter->k);
2488 if (unlikely(!k.k))
2489 goto out_no_locked;
2490 } else {
2491 struct bpos next;
2492 struct bpos end = iter->pos;
2493
2494 if (iter->flags & BTREE_ITER_IS_EXTENTS)
2495 end.offset = U64_MAX;
2496
2497 EBUG_ON(btree_iter_path(trans, iter)->level);
2498
2499 if (iter->flags & BTREE_ITER_INTENT) {
2500 struct btree_iter iter2;
2501
2502 bch2_trans_copy_iter(&iter2, iter);
2503 k = bch2_btree_iter_peek_upto(&iter2, end);
2504
2505 if (k.k && !bkey_err(k)) {
2506 iter->k = iter2.k;
2507 k.k = &iter->k;
2508 }
2509 bch2_trans_iter_exit(trans, &iter2);
2510 } else {
2511 struct bpos pos = iter->pos;
2512
2513 k = bch2_btree_iter_peek_upto(iter, end);
2514 if (unlikely(bkey_err(k)))
2515 bch2_btree_iter_set_pos(iter, pos);
2516 else
2517 iter->pos = pos;
2518 }
2519
2520 if (unlikely(bkey_err(k)))
2521 goto out_no_locked;
2522
2523 next = k.k ? bkey_start_pos(k.k) : POS_MAX;
2524
2525 if (bkey_lt(iter->pos, next)) {
2526 bkey_init(&iter->k);
2527 iter->k.p = iter->pos;
2528
2529 if (iter->flags & BTREE_ITER_IS_EXTENTS) {
2530 bch2_key_resize(&iter->k,
2531 min_t(u64, KEY_SIZE_MAX,
2532 (next.inode == iter->pos.inode
2533 ? next.offset
2534 : KEY_OFFSET_MAX) -
2535 iter->pos.offset));
2536 EBUG_ON(!iter->k.size);
2537 }
2538
2539 k = (struct bkey_s_c) { &iter->k, NULL };
2540 }
2541 }
2542 out:
2543 btree_path_set_should_be_locked(btree_iter_path(trans, iter));
2544 out_no_locked:
2545 bch2_btree_iter_verify_entry_exit(iter);
2546 bch2_btree_iter_verify(iter);
2547 ret = bch2_btree_iter_verify_ret(iter, k);
2548 if (unlikely(ret))
2549 return bkey_s_c_err(ret);
2550
2551 return k;
2552 }
2553
bch2_btree_iter_next_slot(struct btree_iter * iter)2554 struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *iter)
2555 {
2556 if (!bch2_btree_iter_advance(iter))
2557 return bkey_s_c_null;
2558
2559 return bch2_btree_iter_peek_slot(iter);
2560 }
2561
bch2_btree_iter_prev_slot(struct btree_iter * iter)2562 struct bkey_s_c bch2_btree_iter_prev_slot(struct btree_iter *iter)
2563 {
2564 if (!bch2_btree_iter_rewind(iter))
2565 return bkey_s_c_null;
2566
2567 return bch2_btree_iter_peek_slot(iter);
2568 }
2569
bch2_btree_iter_peek_and_restart_outlined(struct btree_iter * iter)2570 struct bkey_s_c bch2_btree_iter_peek_and_restart_outlined(struct btree_iter *iter)
2571 {
2572 struct bkey_s_c k;
2573
2574 while (btree_trans_too_many_iters(iter->trans) ||
2575 (k = bch2_btree_iter_peek_type(iter, iter->flags),
2576 bch2_err_matches(bkey_err(k), BCH_ERR_transaction_restart)))
2577 bch2_trans_begin(iter->trans);
2578
2579 return k;
2580 }
2581
2582 /* new transactional stuff: */
2583
2584 #ifdef CONFIG_BCACHEFS_DEBUG
btree_trans_verify_sorted_refs(struct btree_trans * trans)2585 static void btree_trans_verify_sorted_refs(struct btree_trans *trans)
2586 {
2587 struct btree_path *path;
2588 unsigned i;
2589
2590 BUG_ON(trans->nr_sorted != bitmap_weight(trans->paths_allocated, trans->nr_paths) - 1);
2591
2592 trans_for_each_path(trans, path, i) {
2593 BUG_ON(path->sorted_idx >= trans->nr_sorted);
2594 BUG_ON(trans->sorted[path->sorted_idx] != i);
2595 }
2596
2597 for (i = 0; i < trans->nr_sorted; i++) {
2598 unsigned idx = trans->sorted[i];
2599
2600 BUG_ON(!test_bit(idx, trans->paths_allocated));
2601 BUG_ON(trans->paths[idx].sorted_idx != i);
2602 }
2603 }
2604
btree_trans_verify_sorted(struct btree_trans * trans)2605 static void btree_trans_verify_sorted(struct btree_trans *trans)
2606 {
2607 struct btree_path *path, *prev = NULL;
2608 struct trans_for_each_path_inorder_iter iter;
2609
2610 if (!bch2_debug_check_iterators)
2611 return;
2612
2613 trans_for_each_path_inorder(trans, path, iter) {
2614 if (prev && btree_path_cmp(prev, path) > 0) {
2615 __bch2_dump_trans_paths_updates(trans, true);
2616 panic("trans paths out of order!\n");
2617 }
2618 prev = path;
2619 }
2620 }
2621 #else
btree_trans_verify_sorted_refs(struct btree_trans * trans)2622 static inline void btree_trans_verify_sorted_refs(struct btree_trans *trans) {}
btree_trans_verify_sorted(struct btree_trans * trans)2623 static inline void btree_trans_verify_sorted(struct btree_trans *trans) {}
2624 #endif
2625
__bch2_btree_trans_sort_paths(struct btree_trans * trans)2626 void __bch2_btree_trans_sort_paths(struct btree_trans *trans)
2627 {
2628 int i, l = 0, r = trans->nr_sorted, inc = 1;
2629 bool swapped;
2630
2631 btree_trans_verify_sorted_refs(trans);
2632
2633 if (trans->paths_sorted)
2634 goto out;
2635
2636 /*
2637 * Cocktail shaker sort: this is efficient because iterators will be
2638 * mostly sorted.
2639 */
2640 do {
2641 swapped = false;
2642
2643 for (i = inc > 0 ? l : r - 2;
2644 i + 1 < r && i >= l;
2645 i += inc) {
2646 if (btree_path_cmp(trans->paths + trans->sorted[i],
2647 trans->paths + trans->sorted[i + 1]) > 0) {
2648 swap(trans->sorted[i], trans->sorted[i + 1]);
2649 trans->paths[trans->sorted[i]].sorted_idx = i;
2650 trans->paths[trans->sorted[i + 1]].sorted_idx = i + 1;
2651 swapped = true;
2652 }
2653 }
2654
2655 if (inc > 0)
2656 --r;
2657 else
2658 l++;
2659 inc = -inc;
2660 } while (swapped);
2661
2662 trans->paths_sorted = true;
2663 out:
2664 btree_trans_verify_sorted(trans);
2665 }
2666
btree_path_list_remove(struct btree_trans * trans,struct btree_path * path)2667 static inline void btree_path_list_remove(struct btree_trans *trans,
2668 struct btree_path *path)
2669 {
2670 EBUG_ON(path->sorted_idx >= trans->nr_sorted);
2671 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
2672 trans->nr_sorted--;
2673 memmove_u64s_down_small(trans->sorted + path->sorted_idx,
2674 trans->sorted + path->sorted_idx + 1,
2675 DIV_ROUND_UP(trans->nr_sorted - path->sorted_idx,
2676 sizeof(u64) / sizeof(btree_path_idx_t)));
2677 #else
2678 array_remove_item(trans->sorted, trans->nr_sorted, path->sorted_idx);
2679 #endif
2680 for (unsigned i = path->sorted_idx; i < trans->nr_sorted; i++)
2681 trans->paths[trans->sorted[i]].sorted_idx = i;
2682 }
2683
btree_path_list_add(struct btree_trans * trans,btree_path_idx_t pos,btree_path_idx_t path_idx)2684 static inline void btree_path_list_add(struct btree_trans *trans,
2685 btree_path_idx_t pos,
2686 btree_path_idx_t path_idx)
2687 {
2688 struct btree_path *path = trans->paths + path_idx;
2689
2690 path->sorted_idx = pos ? trans->paths[pos].sorted_idx + 1 : trans->nr_sorted;
2691
2692 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS
2693 memmove_u64s_up_small(trans->sorted + path->sorted_idx + 1,
2694 trans->sorted + path->sorted_idx,
2695 DIV_ROUND_UP(trans->nr_sorted - path->sorted_idx,
2696 sizeof(u64) / sizeof(btree_path_idx_t)));
2697 trans->nr_sorted++;
2698 trans->sorted[path->sorted_idx] = path_idx;
2699 #else
2700 array_insert_item(trans->sorted, trans->nr_sorted, path->sorted_idx, path_idx);
2701 #endif
2702
2703 for (unsigned i = path->sorted_idx; i < trans->nr_sorted; i++)
2704 trans->paths[trans->sorted[i]].sorted_idx = i;
2705
2706 btree_trans_verify_sorted_refs(trans);
2707 }
2708
bch2_trans_iter_exit(struct btree_trans * trans,struct btree_iter * iter)2709 void bch2_trans_iter_exit(struct btree_trans *trans, struct btree_iter *iter)
2710 {
2711 if (iter->update_path)
2712 bch2_path_put_nokeep(trans, iter->update_path,
2713 iter->flags & BTREE_ITER_INTENT);
2714 if (iter->path)
2715 bch2_path_put(trans, iter->path,
2716 iter->flags & BTREE_ITER_INTENT);
2717 if (iter->key_cache_path)
2718 bch2_path_put(trans, iter->key_cache_path,
2719 iter->flags & BTREE_ITER_INTENT);
2720 iter->path = 0;
2721 iter->update_path = 0;
2722 iter->key_cache_path = 0;
2723 iter->trans = NULL;
2724 }
2725
bch2_trans_iter_init_outlined(struct btree_trans * trans,struct btree_iter * iter,enum btree_id btree_id,struct bpos pos,unsigned flags)2726 void bch2_trans_iter_init_outlined(struct btree_trans *trans,
2727 struct btree_iter *iter,
2728 enum btree_id btree_id, struct bpos pos,
2729 unsigned flags)
2730 {
2731 bch2_trans_iter_init_common(trans, iter, btree_id, pos, 0, 0,
2732 bch2_btree_iter_flags(trans, btree_id, flags),
2733 _RET_IP_);
2734 }
2735
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)2736 void bch2_trans_node_iter_init(struct btree_trans *trans,
2737 struct btree_iter *iter,
2738 enum btree_id btree_id,
2739 struct bpos pos,
2740 unsigned locks_want,
2741 unsigned depth,
2742 unsigned flags)
2743 {
2744 flags |= BTREE_ITER_NOT_EXTENTS;
2745 flags |= __BTREE_ITER_ALL_SNAPSHOTS;
2746 flags |= BTREE_ITER_ALL_SNAPSHOTS;
2747
2748 bch2_trans_iter_init_common(trans, iter, btree_id, pos, locks_want, depth,
2749 __bch2_btree_iter_flags(trans, btree_id, flags),
2750 _RET_IP_);
2751
2752 iter->min_depth = depth;
2753
2754 struct btree_path *path = btree_iter_path(trans, iter);
2755 BUG_ON(path->locks_want < min(locks_want, BTREE_MAX_DEPTH));
2756 BUG_ON(path->level != depth);
2757 BUG_ON(iter->min_depth != depth);
2758 }
2759
bch2_trans_copy_iter(struct btree_iter * dst,struct btree_iter * src)2760 void bch2_trans_copy_iter(struct btree_iter *dst, struct btree_iter *src)
2761 {
2762 struct btree_trans *trans = src->trans;
2763
2764 *dst = *src;
2765 if (src->path)
2766 __btree_path_get(trans->paths + src->path, src->flags & BTREE_ITER_INTENT);
2767 if (src->update_path)
2768 __btree_path_get(trans->paths + src->update_path, src->flags & BTREE_ITER_INTENT);
2769 dst->key_cache_path = 0;
2770 }
2771
__bch2_trans_kmalloc(struct btree_trans * trans,size_t size)2772 void *__bch2_trans_kmalloc(struct btree_trans *trans, size_t size)
2773 {
2774 struct bch_fs *c = trans->c;
2775 unsigned new_top = trans->mem_top + size;
2776 unsigned old_bytes = trans->mem_bytes;
2777 unsigned new_bytes = roundup_pow_of_two(new_top);
2778 int ret;
2779 void *new_mem;
2780 void *p;
2781
2782 WARN_ON_ONCE(new_bytes > BTREE_TRANS_MEM_MAX);
2783
2784 struct btree_transaction_stats *s = btree_trans_stats(trans);
2785 s->max_mem = max(s->max_mem, new_bytes);
2786
2787 new_mem = krealloc(trans->mem, new_bytes, GFP_NOWAIT|__GFP_NOWARN);
2788 if (unlikely(!new_mem)) {
2789 bch2_trans_unlock(trans);
2790
2791 new_mem = krealloc(trans->mem, new_bytes, GFP_KERNEL);
2792 if (!new_mem && new_bytes <= BTREE_TRANS_MEM_MAX) {
2793 new_mem = mempool_alloc(&c->btree_trans_mem_pool, GFP_KERNEL);
2794 new_bytes = BTREE_TRANS_MEM_MAX;
2795 kfree(trans->mem);
2796 }
2797
2798 if (!new_mem)
2799 return ERR_PTR(-BCH_ERR_ENOMEM_trans_kmalloc);
2800
2801 trans->mem = new_mem;
2802 trans->mem_bytes = new_bytes;
2803
2804 ret = bch2_trans_relock(trans);
2805 if (ret)
2806 return ERR_PTR(ret);
2807 }
2808
2809 trans->mem = new_mem;
2810 trans->mem_bytes = new_bytes;
2811
2812 if (old_bytes) {
2813 trace_and_count(c, trans_restart_mem_realloced, trans, _RET_IP_, new_bytes);
2814 return ERR_PTR(btree_trans_restart(trans, BCH_ERR_transaction_restart_mem_realloced));
2815 }
2816
2817 p = trans->mem + trans->mem_top;
2818 trans->mem_top += size;
2819 memset(p, 0, size);
2820 return p;
2821 }
2822
check_srcu_held_too_long(struct btree_trans * trans)2823 static inline void check_srcu_held_too_long(struct btree_trans *trans)
2824 {
2825 WARN(trans->srcu_held && time_after(jiffies, trans->srcu_lock_time + HZ * 10),
2826 "btree trans held srcu lock (delaying memory reclaim) for %lu seconds",
2827 (jiffies - trans->srcu_lock_time) / HZ);
2828 }
2829
bch2_trans_srcu_unlock(struct btree_trans * trans)2830 void bch2_trans_srcu_unlock(struct btree_trans *trans)
2831 {
2832 if (trans->srcu_held) {
2833 struct bch_fs *c = trans->c;
2834 struct btree_path *path;
2835 unsigned i;
2836
2837 trans_for_each_path(trans, path, i)
2838 if (path->cached && !btree_node_locked(path, 0))
2839 path->l[0].b = ERR_PTR(-BCH_ERR_no_btree_node_srcu_reset);
2840
2841 check_srcu_held_too_long(trans);
2842 srcu_read_unlock(&c->btree_trans_barrier, trans->srcu_idx);
2843 trans->srcu_held = false;
2844 }
2845 }
2846
bch2_trans_srcu_lock(struct btree_trans * trans)2847 static void bch2_trans_srcu_lock(struct btree_trans *trans)
2848 {
2849 if (!trans->srcu_held) {
2850 trans->srcu_idx = srcu_read_lock(&trans->c->btree_trans_barrier);
2851 trans->srcu_lock_time = jiffies;
2852 trans->srcu_held = true;
2853 }
2854 }
2855
2856 /**
2857 * bch2_trans_begin() - reset a transaction after a interrupted attempt
2858 * @trans: transaction to reset
2859 *
2860 * Returns: current restart counter, to be used with trans_was_restarted()
2861 *
2862 * While iterating over nodes or updating nodes a attempt to lock a btree node
2863 * may return BCH_ERR_transaction_restart when the trylock fails. When this
2864 * occurs bch2_trans_begin() should be called and the transaction retried.
2865 */
bch2_trans_begin(struct btree_trans * trans)2866 u32 bch2_trans_begin(struct btree_trans *trans)
2867 {
2868 struct btree_path *path;
2869 unsigned i;
2870 u64 now;
2871
2872 bch2_trans_reset_updates(trans);
2873
2874 trans->restart_count++;
2875 trans->mem_top = 0;
2876 trans->journal_entries = NULL;
2877
2878 trans_for_each_path(trans, path, i) {
2879 path->should_be_locked = false;
2880
2881 /*
2882 * If the transaction wasn't restarted, we're presuming to be
2883 * doing something new: dont keep iterators excpt the ones that
2884 * are in use - except for the subvolumes btree:
2885 */
2886 if (!trans->restarted && path->btree_id != BTREE_ID_subvolumes)
2887 path->preserve = false;
2888
2889 /*
2890 * XXX: we probably shouldn't be doing this if the transaction
2891 * was restarted, but currently we still overflow transaction
2892 * iterators if we do that
2893 */
2894 if (!path->ref && !path->preserve)
2895 __bch2_path_free(trans, i);
2896 else
2897 path->preserve = false;
2898 }
2899
2900 now = local_clock();
2901
2902 if (!IS_ENABLED(CONFIG_BCACHEFS_NO_LATENCY_ACCT) &&
2903 time_after64(now, trans->last_begin_time + 10))
2904 __bch2_time_stats_update(&btree_trans_stats(trans)->duration,
2905 trans->last_begin_time, now);
2906
2907 if (!trans->restarted &&
2908 (need_resched() ||
2909 time_after64(now, trans->last_begin_time + BTREE_TRANS_MAX_LOCK_HOLD_TIME_NS))) {
2910 drop_locks_do(trans, (cond_resched(), 0));
2911 now = local_clock();
2912 }
2913 trans->last_begin_time = now;
2914
2915 if (unlikely(trans->srcu_held &&
2916 time_after(jiffies, trans->srcu_lock_time + msecs_to_jiffies(10))))
2917 bch2_trans_srcu_unlock(trans);
2918
2919 trans->last_begin_ip = _RET_IP_;
2920 if (trans->restarted) {
2921 bch2_btree_path_traverse_all(trans);
2922 trans->notrace_relock_fail = false;
2923 }
2924
2925 return trans->restart_count;
2926 }
2927
2928 const char *bch2_btree_transaction_fns[BCH_TRANSACTIONS_NR] = { "(unknown)" };
2929
bch2_trans_get_fn_idx(const char * fn)2930 unsigned bch2_trans_get_fn_idx(const char *fn)
2931 {
2932 for (unsigned i = 0; i < ARRAY_SIZE(bch2_btree_transaction_fns); i++)
2933 if (!bch2_btree_transaction_fns[i] ||
2934 bch2_btree_transaction_fns[i] == fn) {
2935 bch2_btree_transaction_fns[i] = fn;
2936 return i;
2937 }
2938
2939 pr_warn_once("BCH_TRANSACTIONS_NR not big enough!");
2940 return 0;
2941 }
2942
__bch2_trans_get(struct bch_fs * c,unsigned fn_idx)2943 struct btree_trans *__bch2_trans_get(struct bch_fs *c, unsigned fn_idx)
2944 __acquires(&c->btree_trans_barrier)
2945 {
2946 struct btree_trans *trans;
2947
2948 if (IS_ENABLED(__KERNEL__)) {
2949 trans = this_cpu_xchg(c->btree_trans_bufs->trans, NULL);
2950 if (trans) {
2951 memset(trans, 0, offsetof(struct btree_trans, list));
2952 goto got_trans;
2953 }
2954 }
2955
2956 trans = mempool_alloc(&c->btree_trans_pool, GFP_NOFS);
2957 memset(trans, 0, sizeof(*trans));
2958 closure_init_stack(&trans->ref);
2959
2960 seqmutex_lock(&c->btree_trans_lock);
2961 if (IS_ENABLED(CONFIG_BCACHEFS_DEBUG)) {
2962 struct btree_trans *pos;
2963 pid_t pid = current->pid;
2964
2965 trans->locking_wait.task = current;
2966
2967 list_for_each_entry(pos, &c->btree_trans_list, list) {
2968 struct task_struct *pos_task = READ_ONCE(pos->locking_wait.task);
2969 /*
2970 * We'd much prefer to be stricter here and completely
2971 * disallow multiple btree_trans in the same thread -
2972 * but the data move path calls bch2_write when we
2973 * already have a btree_trans initialized.
2974 */
2975 BUG_ON(pos_task &&
2976 pid == pos_task->pid &&
2977 bch2_trans_locked(pos));
2978
2979 if (pos_task && pid < pos_task->pid) {
2980 list_add_tail(&trans->list, &pos->list);
2981 goto list_add_done;
2982 }
2983 }
2984 }
2985 list_add_tail(&trans->list, &c->btree_trans_list);
2986 list_add_done:
2987 seqmutex_unlock(&c->btree_trans_lock);
2988 got_trans:
2989 trans->c = c;
2990 trans->last_begin_time = local_clock();
2991 trans->fn_idx = fn_idx;
2992 trans->locking_wait.task = current;
2993 trans->journal_replay_not_finished =
2994 unlikely(!test_bit(JOURNAL_REPLAY_DONE, &c->journal.flags)) &&
2995 atomic_inc_not_zero(&c->journal_keys.ref);
2996 trans->nr_paths = ARRAY_SIZE(trans->_paths);
2997 trans->paths_allocated = trans->_paths_allocated;
2998 trans->sorted = trans->_sorted;
2999 trans->paths = trans->_paths;
3000 trans->updates = trans->_updates;
3001
3002 *trans_paths_nr(trans->paths) = BTREE_ITER_INITIAL;
3003
3004 trans->paths_allocated[0] = 1;
3005
3006 if (fn_idx < BCH_TRANSACTIONS_NR) {
3007 trans->fn = bch2_btree_transaction_fns[fn_idx];
3008
3009 struct btree_transaction_stats *s = &c->btree_transaction_stats[fn_idx];
3010
3011 if (s->max_mem) {
3012 unsigned expected_mem_bytes = roundup_pow_of_two(s->max_mem);
3013
3014 trans->mem = kmalloc(expected_mem_bytes, GFP_KERNEL);
3015 if (likely(trans->mem))
3016 trans->mem_bytes = expected_mem_bytes;
3017 }
3018
3019 trans->nr_paths_max = s->nr_max_paths;
3020 trans->journal_entries_size = s->journal_entries_size;
3021 }
3022
3023 trans->srcu_idx = srcu_read_lock(&c->btree_trans_barrier);
3024 trans->srcu_lock_time = jiffies;
3025 trans->srcu_held = true;
3026 return trans;
3027 }
3028
check_btree_paths_leaked(struct btree_trans * trans)3029 static void check_btree_paths_leaked(struct btree_trans *trans)
3030 {
3031 #ifdef CONFIG_BCACHEFS_DEBUG
3032 struct bch_fs *c = trans->c;
3033 struct btree_path *path;
3034 unsigned i;
3035
3036 trans_for_each_path(trans, path, i)
3037 if (path->ref)
3038 goto leaked;
3039 return;
3040 leaked:
3041 bch_err(c, "btree paths leaked from %s!", trans->fn);
3042 trans_for_each_path(trans, path, i)
3043 if (path->ref)
3044 printk(KERN_ERR " btree %s %pS\n",
3045 bch2_btree_id_str(path->btree_id),
3046 (void *) path->ip_allocated);
3047 /* Be noisy about this: */
3048 bch2_fatal_error(c);
3049 #endif
3050 }
3051
bch2_trans_put(struct btree_trans * trans)3052 void bch2_trans_put(struct btree_trans *trans)
3053 __releases(&c->btree_trans_barrier)
3054 {
3055 struct bch_fs *c = trans->c;
3056
3057 bch2_trans_unlock(trans);
3058
3059 trans_for_each_update(trans, i)
3060 __btree_path_put(trans->paths + i->path, true);
3061 trans->nr_updates = 0;
3062 trans->locking_wait.task = NULL;
3063
3064 check_btree_paths_leaked(trans);
3065
3066 if (trans->srcu_held) {
3067 check_srcu_held_too_long(trans);
3068 srcu_read_unlock(&c->btree_trans_barrier, trans->srcu_idx);
3069 }
3070
3071 if (trans->fs_usage_deltas) {
3072 if (trans->fs_usage_deltas->size + sizeof(trans->fs_usage_deltas) ==
3073 REPLICAS_DELTA_LIST_MAX)
3074 mempool_free(trans->fs_usage_deltas,
3075 &c->replicas_delta_pool);
3076 else
3077 kfree(trans->fs_usage_deltas);
3078 }
3079
3080 if (unlikely(trans->journal_replay_not_finished))
3081 bch2_journal_keys_put(c);
3082
3083 unsigned long *paths_allocated = trans->paths_allocated;
3084 trans->paths_allocated = NULL;
3085 trans->paths = NULL;
3086
3087 if (paths_allocated != trans->_paths_allocated)
3088 kfree_rcu_mightsleep(paths_allocated);
3089
3090 if (trans->mem_bytes == BTREE_TRANS_MEM_MAX)
3091 mempool_free(trans->mem, &c->btree_trans_mem_pool);
3092 else
3093 kfree(trans->mem);
3094
3095 /* Userspace doesn't have a real percpu implementation: */
3096 if (IS_ENABLED(__KERNEL__))
3097 trans = this_cpu_xchg(c->btree_trans_bufs->trans, trans);
3098
3099 if (trans) {
3100 closure_sync(&trans->ref);
3101
3102 seqmutex_lock(&c->btree_trans_lock);
3103 list_del(&trans->list);
3104 seqmutex_unlock(&c->btree_trans_lock);
3105
3106 mempool_free(trans, &c->btree_trans_pool);
3107 }
3108 }
3109
3110 static void __maybe_unused
bch2_btree_bkey_cached_common_to_text(struct printbuf * out,struct btree_bkey_cached_common * b)3111 bch2_btree_bkey_cached_common_to_text(struct printbuf *out,
3112 struct btree_bkey_cached_common *b)
3113 {
3114 struct six_lock_count c = six_lock_counts(&b->lock);
3115 struct task_struct *owner;
3116 pid_t pid;
3117
3118 rcu_read_lock();
3119 owner = READ_ONCE(b->lock.owner);
3120 pid = owner ? owner->pid : 0;
3121 rcu_read_unlock();
3122
3123 prt_tab(out);
3124 prt_printf(out, "%px %c l=%u %s:", b, b->cached ? 'c' : 'b',
3125 b->level, bch2_btree_id_str(b->btree_id));
3126 bch2_bpos_to_text(out, btree_node_pos(b));
3127
3128 prt_tab(out);
3129 prt_printf(out, " locks %u:%u:%u held by pid %u",
3130 c.n[0], c.n[1], c.n[2], pid);
3131 }
3132
bch2_btree_trans_to_text(struct printbuf * out,struct btree_trans * trans)3133 void bch2_btree_trans_to_text(struct printbuf *out, struct btree_trans *trans)
3134 {
3135 struct btree_bkey_cached_common *b;
3136 static char lock_types[] = { 'r', 'i', 'w' };
3137 struct task_struct *task = READ_ONCE(trans->locking_wait.task);
3138 unsigned l, idx;
3139
3140 /* before rcu_read_lock(): */
3141 bch2_printbuf_make_room(out, 4096);
3142
3143 if (!out->nr_tabstops) {
3144 printbuf_tabstop_push(out, 16);
3145 printbuf_tabstop_push(out, 32);
3146 }
3147
3148 prt_printf(out, "%i %s\n", task ? task->pid : 0, trans->fn);
3149
3150 /* trans->paths is rcu protected vs. freeing */
3151 rcu_read_lock();
3152 out->atomic++;
3153
3154 struct btree_path *paths = rcu_dereference(trans->paths);
3155 if (!paths)
3156 goto out;
3157
3158 unsigned long *paths_allocated = trans_paths_allocated(paths);
3159
3160 trans_for_each_path_idx_from(paths_allocated, *trans_paths_nr(paths), idx, 1) {
3161 struct btree_path *path = paths + idx;
3162 if (!path->nodes_locked)
3163 continue;
3164
3165 prt_printf(out, " path %u %c l=%u %s:",
3166 idx,
3167 path->cached ? 'c' : 'b',
3168 path->level,
3169 bch2_btree_id_str(path->btree_id));
3170 bch2_bpos_to_text(out, path->pos);
3171 prt_newline(out);
3172
3173 for (l = 0; l < BTREE_MAX_DEPTH; l++) {
3174 if (btree_node_locked(path, l) &&
3175 !IS_ERR_OR_NULL(b = (void *) READ_ONCE(path->l[l].b))) {
3176 prt_printf(out, " %c l=%u ",
3177 lock_types[btree_node_locked_type(path, l)], l);
3178 bch2_btree_bkey_cached_common_to_text(out, b);
3179 prt_newline(out);
3180 }
3181 }
3182 }
3183
3184 b = READ_ONCE(trans->locking);
3185 if (b) {
3186 prt_printf(out, " blocked for %lluus on",
3187 div_u64(local_clock() - trans->locking_wait.start_time,
3188 1000));
3189 prt_newline(out);
3190 prt_printf(out, " %c", lock_types[trans->locking_wait.lock_want]);
3191 bch2_btree_bkey_cached_common_to_text(out, b);
3192 prt_newline(out);
3193 }
3194 out:
3195 --out->atomic;
3196 rcu_read_unlock();
3197 }
3198
bch2_fs_btree_iter_exit(struct bch_fs * c)3199 void bch2_fs_btree_iter_exit(struct bch_fs *c)
3200 {
3201 struct btree_transaction_stats *s;
3202 struct btree_trans *trans;
3203 int cpu;
3204
3205 if (c->btree_trans_bufs)
3206 for_each_possible_cpu(cpu) {
3207 struct btree_trans *trans =
3208 per_cpu_ptr(c->btree_trans_bufs, cpu)->trans;
3209
3210 if (trans) {
3211 closure_sync(&trans->ref);
3212
3213 seqmutex_lock(&c->btree_trans_lock);
3214 list_del(&trans->list);
3215 seqmutex_unlock(&c->btree_trans_lock);
3216 }
3217 kfree(trans);
3218 }
3219 free_percpu(c->btree_trans_bufs);
3220
3221 trans = list_first_entry_or_null(&c->btree_trans_list, struct btree_trans, list);
3222 if (trans)
3223 panic("%s leaked btree_trans\n", trans->fn);
3224
3225 for (s = c->btree_transaction_stats;
3226 s < c->btree_transaction_stats + ARRAY_SIZE(c->btree_transaction_stats);
3227 s++) {
3228 kfree(s->max_paths_text);
3229 bch2_time_stats_exit(&s->lock_hold_times);
3230 }
3231
3232 if (c->btree_trans_barrier_initialized)
3233 cleanup_srcu_struct(&c->btree_trans_barrier);
3234 mempool_exit(&c->btree_trans_mem_pool);
3235 mempool_exit(&c->btree_trans_pool);
3236 }
3237
bch2_fs_btree_iter_init_early(struct bch_fs * c)3238 void bch2_fs_btree_iter_init_early(struct bch_fs *c)
3239 {
3240 struct btree_transaction_stats *s;
3241
3242 for (s = c->btree_transaction_stats;
3243 s < c->btree_transaction_stats + ARRAY_SIZE(c->btree_transaction_stats);
3244 s++) {
3245 bch2_time_stats_init(&s->duration);
3246 bch2_time_stats_init(&s->lock_hold_times);
3247 mutex_init(&s->lock);
3248 }
3249
3250 INIT_LIST_HEAD(&c->btree_trans_list);
3251 seqmutex_init(&c->btree_trans_lock);
3252 }
3253
bch2_fs_btree_iter_init(struct bch_fs * c)3254 int bch2_fs_btree_iter_init(struct bch_fs *c)
3255 {
3256 int ret;
3257
3258 c->btree_trans_bufs = alloc_percpu(struct btree_trans_buf);
3259 if (!c->btree_trans_bufs)
3260 return -ENOMEM;
3261
3262 ret = mempool_init_kmalloc_pool(&c->btree_trans_pool, 1,
3263 sizeof(struct btree_trans)) ?:
3264 mempool_init_kmalloc_pool(&c->btree_trans_mem_pool, 1,
3265 BTREE_TRANS_MEM_MAX) ?:
3266 init_srcu_struct(&c->btree_trans_barrier);
3267 if (!ret)
3268 c->btree_trans_barrier_initialized = true;
3269 return ret;
3270 }
3271