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 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 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 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 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 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 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 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 } 102 103 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 } 108 109 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 120 121 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 } 137 138 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 } 219 220 static void bch2_btree_path_verify(struct btree_trans *trans, 221 struct btree_path *path) 222 { 223 struct bch_fs *c = trans->c; 224 225 for (unsigned i = 0; i < (!path->cached ? BTREE_MAX_DEPTH : 1); i++) { 226 if (!path->l[i].b) { 227 BUG_ON(!path->cached && 228 bch2_btree_id_root(c, path->btree_id)->b->c.level > i); 229 break; 230 } 231 232 bch2_btree_path_verify_level(trans, path, i); 233 } 234 235 bch2_btree_path_verify_locks(path); 236 } 237 238 void bch2_trans_verify_paths(struct btree_trans *trans) 239 { 240 struct btree_path *path; 241 unsigned iter; 242 243 trans_for_each_path(trans, path, iter) 244 bch2_btree_path_verify(trans, path); 245 } 246 247 static void bch2_btree_iter_verify(struct btree_iter *iter) 248 { 249 struct btree_trans *trans = iter->trans; 250 251 BUG_ON(!!(iter->flags & BTREE_ITER_cached) != btree_iter_path(trans, iter)->cached); 252 253 BUG_ON((iter->flags & BTREE_ITER_is_extents) && 254 (iter->flags & BTREE_ITER_all_snapshots)); 255 256 BUG_ON(!(iter->flags & BTREE_ITER_snapshot_field) && 257 (iter->flags & BTREE_ITER_all_snapshots) && 258 !btree_type_has_snapshot_field(iter->btree_id)); 259 260 if (iter->update_path) 261 bch2_btree_path_verify(trans, &trans->paths[iter->update_path]); 262 bch2_btree_path_verify(trans, btree_iter_path(trans, iter)); 263 } 264 265 static void bch2_btree_iter_verify_entry_exit(struct btree_iter *iter) 266 { 267 BUG_ON((iter->flags & BTREE_ITER_filter_snapshots) && 268 !iter->pos.snapshot); 269 270 BUG_ON(!(iter->flags & BTREE_ITER_all_snapshots) && 271 iter->pos.snapshot != iter->snapshot); 272 273 BUG_ON(bkey_lt(iter->pos, bkey_start_pos(&iter->k)) || 274 bkey_gt(iter->pos, iter->k.p)); 275 } 276 277 static int bch2_btree_iter_verify_ret(struct btree_iter *iter, struct bkey_s_c k) 278 { 279 struct btree_trans *trans = iter->trans; 280 struct btree_iter copy; 281 struct bkey_s_c prev; 282 int ret = 0; 283 284 if (!bch2_debug_check_iterators) 285 return 0; 286 287 if (!(iter->flags & BTREE_ITER_filter_snapshots)) 288 return 0; 289 290 if (bkey_err(k) || !k.k) 291 return 0; 292 293 BUG_ON(!bch2_snapshot_is_ancestor(trans->c, 294 iter->snapshot, 295 k.k->p.snapshot)); 296 297 bch2_trans_iter_init(trans, ©, iter->btree_id, iter->pos, 298 BTREE_ITER_nopreserve| 299 BTREE_ITER_all_snapshots); 300 prev = bch2_btree_iter_prev(©); 301 if (!prev.k) 302 goto out; 303 304 ret = bkey_err(prev); 305 if (ret) 306 goto out; 307 308 if (bkey_eq(prev.k->p, k.k->p) && 309 bch2_snapshot_is_ancestor(trans->c, iter->snapshot, 310 prev.k->p.snapshot) > 0) { 311 struct printbuf buf1 = PRINTBUF, buf2 = PRINTBUF; 312 313 bch2_bkey_to_text(&buf1, k.k); 314 bch2_bkey_to_text(&buf2, prev.k); 315 316 panic("iter snap %u\n" 317 "k %s\n" 318 "prev %s\n", 319 iter->snapshot, 320 buf1.buf, buf2.buf); 321 } 322 out: 323 bch2_trans_iter_exit(trans, ©); 324 return ret; 325 } 326 327 void bch2_assert_pos_locked(struct btree_trans *trans, enum btree_id id, 328 struct bpos pos, bool key_cache) 329 { 330 bch2_trans_verify_not_unlocked(trans); 331 332 struct btree_path *path; 333 struct trans_for_each_path_inorder_iter iter; 334 struct printbuf buf = PRINTBUF; 335 336 btree_trans_sort_paths(trans); 337 338 trans_for_each_path_inorder(trans, path, iter) { 339 int cmp = cmp_int(path->btree_id, id) ?: 340 cmp_int(path->cached, key_cache); 341 342 if (cmp > 0) 343 break; 344 if (cmp < 0) 345 continue; 346 347 if (!btree_node_locked(path, 0) || 348 !path->should_be_locked) 349 continue; 350 351 if (!key_cache) { 352 if (bkey_ge(pos, path->l[0].b->data->min_key) && 353 bkey_le(pos, path->l[0].b->key.k.p)) 354 return; 355 } else { 356 if (bkey_eq(pos, path->pos)) 357 return; 358 } 359 } 360 361 bch2_dump_trans_paths_updates(trans); 362 bch2_bpos_to_text(&buf, pos); 363 364 panic("not locked: %s %s%s\n", 365 bch2_btree_id_str(id), buf.buf, 366 key_cache ? " cached" : ""); 367 } 368 369 #else 370 371 static inline void bch2_btree_path_verify_level(struct btree_trans *trans, 372 struct btree_path *path, unsigned l) {} 373 static inline void bch2_btree_path_verify(struct btree_trans *trans, 374 struct btree_path *path) {} 375 static inline void bch2_btree_iter_verify(struct btree_iter *iter) {} 376 static inline void bch2_btree_iter_verify_entry_exit(struct btree_iter *iter) {} 377 static inline int bch2_btree_iter_verify_ret(struct btree_iter *iter, struct bkey_s_c k) { return 0; } 378 379 #endif 380 381 /* Btree path: fixups after btree updates */ 382 383 static void btree_node_iter_set_set_pos(struct btree_node_iter *iter, 384 struct btree *b, 385 struct bset_tree *t, 386 struct bkey_packed *k) 387 { 388 struct btree_node_iter_set *set; 389 390 btree_node_iter_for_each(iter, set) 391 if (set->end == t->end_offset) { 392 set->k = __btree_node_key_to_offset(b, k); 393 bch2_btree_node_iter_sort(iter, b); 394 return; 395 } 396 397 bch2_btree_node_iter_push(iter, b, k, btree_bkey_last(b, t)); 398 } 399 400 static void __bch2_btree_path_fix_key_modified(struct btree_path *path, 401 struct btree *b, 402 struct bkey_packed *where) 403 { 404 struct btree_path_level *l = &path->l[b->c.level]; 405 406 if (where != bch2_btree_node_iter_peek_all(&l->iter, l->b)) 407 return; 408 409 if (bkey_iter_pos_cmp(l->b, where, &path->pos) < 0) 410 bch2_btree_node_iter_advance(&l->iter, l->b); 411 } 412 413 void bch2_btree_path_fix_key_modified(struct btree_trans *trans, 414 struct btree *b, 415 struct bkey_packed *where) 416 { 417 struct btree_path *path; 418 unsigned i; 419 420 trans_for_each_path_with_node(trans, b, path, i) { 421 __bch2_btree_path_fix_key_modified(path, b, where); 422 bch2_btree_path_verify_level(trans, path, b->c.level); 423 } 424 } 425 426 static void __bch2_btree_node_iter_fix(struct btree_path *path, 427 struct btree *b, 428 struct btree_node_iter *node_iter, 429 struct bset_tree *t, 430 struct bkey_packed *where, 431 unsigned clobber_u64s, 432 unsigned new_u64s) 433 { 434 const struct bkey_packed *end = btree_bkey_last(b, t); 435 struct btree_node_iter_set *set; 436 unsigned offset = __btree_node_key_to_offset(b, where); 437 int shift = new_u64s - clobber_u64s; 438 unsigned old_end = t->end_offset - shift; 439 unsigned orig_iter_pos = node_iter->data[0].k; 440 bool iter_current_key_modified = 441 orig_iter_pos >= offset && 442 orig_iter_pos <= offset + clobber_u64s; 443 444 btree_node_iter_for_each(node_iter, set) 445 if (set->end == old_end) 446 goto found; 447 448 /* didn't find the bset in the iterator - might have to readd it: */ 449 if (new_u64s && 450 bkey_iter_pos_cmp(b, where, &path->pos) >= 0) { 451 bch2_btree_node_iter_push(node_iter, b, where, end); 452 goto fixup_done; 453 } else { 454 /* Iterator is after key that changed */ 455 return; 456 } 457 found: 458 set->end = t->end_offset; 459 460 /* Iterator hasn't gotten to the key that changed yet: */ 461 if (set->k < offset) 462 return; 463 464 if (new_u64s && 465 bkey_iter_pos_cmp(b, where, &path->pos) >= 0) { 466 set->k = offset; 467 } else if (set->k < offset + clobber_u64s) { 468 set->k = offset + new_u64s; 469 if (set->k == set->end) 470 bch2_btree_node_iter_set_drop(node_iter, set); 471 } else { 472 /* Iterator is after key that changed */ 473 set->k = (int) set->k + shift; 474 return; 475 } 476 477 bch2_btree_node_iter_sort(node_iter, b); 478 fixup_done: 479 if (node_iter->data[0].k != orig_iter_pos) 480 iter_current_key_modified = true; 481 482 /* 483 * When a new key is added, and the node iterator now points to that 484 * key, the iterator might have skipped past deleted keys that should 485 * come after the key the iterator now points to. We have to rewind to 486 * before those deleted keys - otherwise 487 * bch2_btree_node_iter_prev_all() breaks: 488 */ 489 if (!bch2_btree_node_iter_end(node_iter) && 490 iter_current_key_modified && 491 b->c.level) { 492 struct bkey_packed *k, *k2, *p; 493 494 k = bch2_btree_node_iter_peek_all(node_iter, b); 495 496 for_each_bset(b, t) { 497 bool set_pos = false; 498 499 if (node_iter->data[0].end == t->end_offset) 500 continue; 501 502 k2 = bch2_btree_node_iter_bset_pos(node_iter, b, t); 503 504 while ((p = bch2_bkey_prev_all(b, t, k2)) && 505 bkey_iter_cmp(b, k, p) < 0) { 506 k2 = p; 507 set_pos = true; 508 } 509 510 if (set_pos) 511 btree_node_iter_set_set_pos(node_iter, 512 b, t, k2); 513 } 514 } 515 } 516 517 void bch2_btree_node_iter_fix(struct btree_trans *trans, 518 struct btree_path *path, 519 struct btree *b, 520 struct btree_node_iter *node_iter, 521 struct bkey_packed *where, 522 unsigned clobber_u64s, 523 unsigned new_u64s) 524 { 525 struct bset_tree *t = bch2_bkey_to_bset_inlined(b, where); 526 struct btree_path *linked; 527 unsigned i; 528 529 if (node_iter != &path->l[b->c.level].iter) { 530 __bch2_btree_node_iter_fix(path, b, node_iter, t, 531 where, clobber_u64s, new_u64s); 532 533 if (bch2_debug_check_iterators) 534 bch2_btree_node_iter_verify(node_iter, b); 535 } 536 537 trans_for_each_path_with_node(trans, b, linked, i) { 538 __bch2_btree_node_iter_fix(linked, b, 539 &linked->l[b->c.level].iter, t, 540 where, clobber_u64s, new_u64s); 541 bch2_btree_path_verify_level(trans, linked, b->c.level); 542 } 543 } 544 545 /* Btree path level: pointer to a particular btree node and node iter */ 546 547 static inline struct bkey_s_c __btree_iter_unpack(struct bch_fs *c, 548 struct btree_path_level *l, 549 struct bkey *u, 550 struct bkey_packed *k) 551 { 552 if (unlikely(!k)) { 553 /* 554 * signal to bch2_btree_iter_peek_slot() that we're currently at 555 * a hole 556 */ 557 u->type = KEY_TYPE_deleted; 558 return bkey_s_c_null; 559 } 560 561 return bkey_disassemble(l->b, k, u); 562 } 563 564 static inline struct bkey_s_c btree_path_level_peek_all(struct bch_fs *c, 565 struct btree_path_level *l, 566 struct bkey *u) 567 { 568 return __btree_iter_unpack(c, l, u, 569 bch2_btree_node_iter_peek_all(&l->iter, l->b)); 570 } 571 572 static inline struct bkey_s_c btree_path_level_peek(struct btree_trans *trans, 573 struct btree_path *path, 574 struct btree_path_level *l, 575 struct bkey *u) 576 { 577 struct bkey_s_c k = __btree_iter_unpack(trans->c, l, u, 578 bch2_btree_node_iter_peek(&l->iter, l->b)); 579 580 path->pos = k.k ? k.k->p : l->b->key.k.p; 581 trans->paths_sorted = false; 582 bch2_btree_path_verify_level(trans, path, l - path->l); 583 return k; 584 } 585 586 static inline struct bkey_s_c btree_path_level_prev(struct btree_trans *trans, 587 struct btree_path *path, 588 struct btree_path_level *l, 589 struct bkey *u) 590 { 591 struct bkey_s_c k = __btree_iter_unpack(trans->c, l, u, 592 bch2_btree_node_iter_prev(&l->iter, l->b)); 593 594 path->pos = k.k ? k.k->p : l->b->data->min_key; 595 trans->paths_sorted = false; 596 bch2_btree_path_verify_level(trans, path, l - path->l); 597 return k; 598 } 599 600 static inline bool btree_path_advance_to_pos(struct btree_path *path, 601 struct btree_path_level *l, 602 int max_advance) 603 { 604 struct bkey_packed *k; 605 int nr_advanced = 0; 606 607 while ((k = bch2_btree_node_iter_peek_all(&l->iter, l->b)) && 608 bkey_iter_pos_cmp(l->b, k, &path->pos) < 0) { 609 if (max_advance > 0 && nr_advanced >= max_advance) 610 return false; 611 612 bch2_btree_node_iter_advance(&l->iter, l->b); 613 nr_advanced++; 614 } 615 616 return true; 617 } 618 619 static inline void __btree_path_level_init(struct btree_path *path, 620 unsigned level) 621 { 622 struct btree_path_level *l = &path->l[level]; 623 624 bch2_btree_node_iter_init(&l->iter, l->b, &path->pos); 625 626 /* 627 * Iterators to interior nodes should always be pointed at the first non 628 * whiteout: 629 */ 630 if (level) 631 bch2_btree_node_iter_peek(&l->iter, l->b); 632 } 633 634 void bch2_btree_path_level_init(struct btree_trans *trans, 635 struct btree_path *path, 636 struct btree *b) 637 { 638 BUG_ON(path->cached); 639 640 EBUG_ON(!btree_path_pos_in_node(path, b)); 641 642 path->l[b->c.level].lock_seq = six_lock_seq(&b->c.lock); 643 path->l[b->c.level].b = b; 644 __btree_path_level_init(path, b->c.level); 645 } 646 647 /* Btree path: fixups after btree node updates: */ 648 649 static void bch2_trans_revalidate_updates_in_node(struct btree_trans *trans, struct btree *b) 650 { 651 struct bch_fs *c = trans->c; 652 653 trans_for_each_update(trans, i) 654 if (!i->cached && 655 i->level == b->c.level && 656 i->btree_id == b->c.btree_id && 657 bpos_cmp(i->k->k.p, b->data->min_key) >= 0 && 658 bpos_cmp(i->k->k.p, b->data->max_key) <= 0) { 659 i->old_v = bch2_btree_path_peek_slot(trans->paths + i->path, &i->old_k).v; 660 661 if (unlikely(trans->journal_replay_not_finished)) { 662 struct bkey_i *j_k = 663 bch2_journal_keys_peek_slot(c, i->btree_id, i->level, 664 i->k->k.p); 665 666 if (j_k) { 667 i->old_k = j_k->k; 668 i->old_v = &j_k->v; 669 } 670 } 671 } 672 } 673 674 /* 675 * A btree node is being replaced - update the iterator to point to the new 676 * node: 677 */ 678 void bch2_trans_node_add(struct btree_trans *trans, 679 struct btree_path *path, 680 struct btree *b) 681 { 682 struct btree_path *prev; 683 684 BUG_ON(!btree_path_pos_in_node(path, b)); 685 686 while ((prev = prev_btree_path(trans, path)) && 687 btree_path_pos_in_node(prev, b)) 688 path = prev; 689 690 for (; 691 path && btree_path_pos_in_node(path, b); 692 path = next_btree_path(trans, path)) 693 if (path->uptodate == BTREE_ITER_UPTODATE && !path->cached) { 694 enum btree_node_locked_type t = 695 btree_lock_want(path, b->c.level); 696 697 if (t != BTREE_NODE_UNLOCKED) { 698 btree_node_unlock(trans, path, b->c.level); 699 six_lock_increment(&b->c.lock, (enum six_lock_type) t); 700 mark_btree_node_locked(trans, path, b->c.level, t); 701 } 702 703 bch2_btree_path_level_init(trans, path, b); 704 } 705 706 bch2_trans_revalidate_updates_in_node(trans, b); 707 } 708 709 /* 710 * A btree node has been modified in such a way as to invalidate iterators - fix 711 * them: 712 */ 713 void bch2_trans_node_reinit_iter(struct btree_trans *trans, struct btree *b) 714 { 715 struct btree_path *path; 716 unsigned i; 717 718 trans_for_each_path_with_node(trans, b, path, i) 719 __btree_path_level_init(path, b->c.level); 720 721 bch2_trans_revalidate_updates_in_node(trans, b); 722 } 723 724 /* Btree path: traverse, set_pos: */ 725 726 static inline int btree_path_lock_root(struct btree_trans *trans, 727 struct btree_path *path, 728 unsigned depth_want, 729 unsigned long trace_ip) 730 { 731 struct bch_fs *c = trans->c; 732 struct btree *b, **rootp = &bch2_btree_id_root(c, path->btree_id)->b; 733 enum six_lock_type lock_type; 734 unsigned i; 735 int ret; 736 737 EBUG_ON(path->nodes_locked); 738 739 while (1) { 740 b = READ_ONCE(*rootp); 741 path->level = READ_ONCE(b->c.level); 742 743 if (unlikely(path->level < depth_want)) { 744 /* 745 * the root is at a lower depth than the depth we want: 746 * got to the end of the btree, or we're walking nodes 747 * greater than some depth and there are no nodes >= 748 * that depth 749 */ 750 path->level = depth_want; 751 for (i = path->level; i < BTREE_MAX_DEPTH; i++) 752 path->l[i].b = NULL; 753 return 1; 754 } 755 756 lock_type = __btree_lock_want(path, path->level); 757 ret = btree_node_lock(trans, path, &b->c, 758 path->level, lock_type, trace_ip); 759 if (unlikely(ret)) { 760 if (bch2_err_matches(ret, BCH_ERR_lock_fail_root_changed)) 761 continue; 762 if (bch2_err_matches(ret, BCH_ERR_transaction_restart)) 763 return ret; 764 BUG(); 765 } 766 767 if (likely(b == READ_ONCE(*rootp) && 768 b->c.level == path->level && 769 !race_fault())) { 770 for (i = 0; i < path->level; i++) 771 path->l[i].b = ERR_PTR(-BCH_ERR_no_btree_node_lock_root); 772 path->l[path->level].b = b; 773 for (i = path->level + 1; i < BTREE_MAX_DEPTH; i++) 774 path->l[i].b = NULL; 775 776 mark_btree_node_locked(trans, path, path->level, 777 (enum btree_node_locked_type) lock_type); 778 bch2_btree_path_level_init(trans, path, b); 779 return 0; 780 } 781 782 six_unlock_type(&b->c.lock, lock_type); 783 } 784 } 785 786 noinline 787 static int btree_path_prefetch(struct btree_trans *trans, struct btree_path *path) 788 { 789 struct bch_fs *c = trans->c; 790 struct btree_path_level *l = path_l(path); 791 struct btree_node_iter node_iter = l->iter; 792 struct bkey_packed *k; 793 struct bkey_buf tmp; 794 unsigned nr = test_bit(BCH_FS_started, &c->flags) 795 ? (path->level > 1 ? 0 : 2) 796 : (path->level > 1 ? 1 : 16); 797 bool was_locked = btree_node_locked(path, path->level); 798 int ret = 0; 799 800 bch2_bkey_buf_init(&tmp); 801 802 while (nr-- && !ret) { 803 if (!bch2_btree_node_relock(trans, path, path->level)) 804 break; 805 806 bch2_btree_node_iter_advance(&node_iter, l->b); 807 k = bch2_btree_node_iter_peek(&node_iter, l->b); 808 if (!k) 809 break; 810 811 bch2_bkey_buf_unpack(&tmp, c, l->b, k); 812 ret = bch2_btree_node_prefetch(trans, path, tmp.k, path->btree_id, 813 path->level - 1); 814 } 815 816 if (!was_locked) 817 btree_node_unlock(trans, path, path->level); 818 819 bch2_bkey_buf_exit(&tmp, c); 820 return ret; 821 } 822 823 static int btree_path_prefetch_j(struct btree_trans *trans, struct btree_path *path, 824 struct btree_and_journal_iter *jiter) 825 { 826 struct bch_fs *c = trans->c; 827 struct bkey_s_c k; 828 struct bkey_buf tmp; 829 unsigned nr = test_bit(BCH_FS_started, &c->flags) 830 ? (path->level > 1 ? 0 : 2) 831 : (path->level > 1 ? 1 : 16); 832 bool was_locked = btree_node_locked(path, path->level); 833 int ret = 0; 834 835 bch2_bkey_buf_init(&tmp); 836 837 while (nr-- && !ret) { 838 if (!bch2_btree_node_relock(trans, path, path->level)) 839 break; 840 841 bch2_btree_and_journal_iter_advance(jiter); 842 k = bch2_btree_and_journal_iter_peek(jiter); 843 if (!k.k) 844 break; 845 846 bch2_bkey_buf_reassemble(&tmp, c, k); 847 ret = bch2_btree_node_prefetch(trans, path, tmp.k, path->btree_id, 848 path->level - 1); 849 } 850 851 if (!was_locked) 852 btree_node_unlock(trans, path, path->level); 853 854 bch2_bkey_buf_exit(&tmp, c); 855 return ret; 856 } 857 858 static noinline void btree_node_mem_ptr_set(struct btree_trans *trans, 859 struct btree_path *path, 860 unsigned plevel, struct btree *b) 861 { 862 struct btree_path_level *l = &path->l[plevel]; 863 bool locked = btree_node_locked(path, plevel); 864 struct bkey_packed *k; 865 struct bch_btree_ptr_v2 *bp; 866 867 if (!bch2_btree_node_relock(trans, path, plevel)) 868 return; 869 870 k = bch2_btree_node_iter_peek_all(&l->iter, l->b); 871 BUG_ON(k->type != KEY_TYPE_btree_ptr_v2); 872 873 bp = (void *) bkeyp_val(&l->b->format, k); 874 bp->mem_ptr = (unsigned long)b; 875 876 if (!locked) 877 btree_node_unlock(trans, path, plevel); 878 } 879 880 static noinline int btree_node_iter_and_journal_peek(struct btree_trans *trans, 881 struct btree_path *path, 882 unsigned flags, 883 struct bkey_buf *out) 884 { 885 struct bch_fs *c = trans->c; 886 struct btree_path_level *l = path_l(path); 887 struct btree_and_journal_iter jiter; 888 struct bkey_s_c k; 889 int ret = 0; 890 891 __bch2_btree_and_journal_iter_init_node_iter(trans, &jiter, l->b, l->iter, path->pos); 892 893 k = bch2_btree_and_journal_iter_peek(&jiter); 894 895 bch2_bkey_buf_reassemble(out, c, k); 896 897 if ((flags & BTREE_ITER_prefetch) && 898 c->opts.btree_node_prefetch) 899 ret = btree_path_prefetch_j(trans, path, &jiter); 900 901 bch2_btree_and_journal_iter_exit(&jiter); 902 return ret; 903 } 904 905 static __always_inline int btree_path_down(struct btree_trans *trans, 906 struct btree_path *path, 907 unsigned flags, 908 unsigned long trace_ip) 909 { 910 struct bch_fs *c = trans->c; 911 struct btree_path_level *l = path_l(path); 912 struct btree *b; 913 unsigned level = path->level - 1; 914 enum six_lock_type lock_type = __btree_lock_want(path, level); 915 struct bkey_buf tmp; 916 int ret; 917 918 EBUG_ON(!btree_node_locked(path, path->level)); 919 920 bch2_bkey_buf_init(&tmp); 921 922 if (unlikely(trans->journal_replay_not_finished)) { 923 ret = btree_node_iter_and_journal_peek(trans, path, flags, &tmp); 924 if (ret) 925 goto err; 926 } else { 927 struct bkey_packed *k = bch2_btree_node_iter_peek(&l->iter, l->b); 928 if (!k) { 929 struct printbuf buf = PRINTBUF; 930 931 prt_str(&buf, "node not found at pos "); 932 bch2_bpos_to_text(&buf, path->pos); 933 prt_str(&buf, " within parent node "); 934 bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(&l->b->key)); 935 936 bch2_fs_fatal_error(c, "%s", buf.buf); 937 printbuf_exit(&buf); 938 ret = -BCH_ERR_btree_need_topology_repair; 939 goto err; 940 } 941 942 bch2_bkey_buf_unpack(&tmp, c, l->b, k); 943 944 if ((flags & BTREE_ITER_prefetch) && 945 c->opts.btree_node_prefetch) { 946 ret = btree_path_prefetch(trans, path); 947 if (ret) 948 goto err; 949 } 950 } 951 952 b = bch2_btree_node_get(trans, path, tmp.k, level, lock_type, trace_ip); 953 ret = PTR_ERR_OR_ZERO(b); 954 if (unlikely(ret)) 955 goto err; 956 957 if (likely(!trans->journal_replay_not_finished && 958 tmp.k->k.type == KEY_TYPE_btree_ptr_v2) && 959 unlikely(b != btree_node_mem_ptr(tmp.k))) 960 btree_node_mem_ptr_set(trans, path, level + 1, b); 961 962 if (btree_node_read_locked(path, level + 1)) 963 btree_node_unlock(trans, path, level + 1); 964 965 mark_btree_node_locked(trans, path, level, 966 (enum btree_node_locked_type) lock_type); 967 path->level = level; 968 bch2_btree_path_level_init(trans, path, b); 969 970 bch2_btree_path_verify_locks(path); 971 err: 972 bch2_bkey_buf_exit(&tmp, c); 973 return ret; 974 } 975 976 static int bch2_btree_path_traverse_all(struct btree_trans *trans) 977 { 978 struct bch_fs *c = trans->c; 979 struct btree_path *path; 980 unsigned long trace_ip = _RET_IP_; 981 unsigned i; 982 int ret = 0; 983 984 if (trans->in_traverse_all) 985 return -BCH_ERR_transaction_restart_in_traverse_all; 986 987 trans->in_traverse_all = true; 988 retry_all: 989 trans->restarted = 0; 990 trans->last_restarted_ip = 0; 991 992 trans_for_each_path(trans, path, i) 993 path->should_be_locked = false; 994 995 btree_trans_sort_paths(trans); 996 997 bch2_trans_unlock(trans); 998 cond_resched(); 999 trans->locked = true; 1000 1001 if (unlikely(trans->memory_allocation_failure)) { 1002 struct closure cl; 1003 1004 closure_init_stack(&cl); 1005 1006 do { 1007 ret = bch2_btree_cache_cannibalize_lock(trans, &cl); 1008 closure_sync(&cl); 1009 } while (ret); 1010 } 1011 1012 /* Now, redo traversals in correct order: */ 1013 i = 0; 1014 while (i < trans->nr_sorted) { 1015 btree_path_idx_t idx = trans->sorted[i]; 1016 1017 /* 1018 * Traversing a path can cause another path to be added at about 1019 * the same position: 1020 */ 1021 if (trans->paths[idx].uptodate) { 1022 __btree_path_get(&trans->paths[idx], false); 1023 ret = bch2_btree_path_traverse_one(trans, idx, 0, _THIS_IP_); 1024 __btree_path_put(&trans->paths[idx], false); 1025 1026 if (bch2_err_matches(ret, BCH_ERR_transaction_restart) || 1027 bch2_err_matches(ret, ENOMEM)) 1028 goto retry_all; 1029 if (ret) 1030 goto err; 1031 } else { 1032 i++; 1033 } 1034 } 1035 1036 /* 1037 * We used to assert that all paths had been traversed here 1038 * (path->uptodate < BTREE_ITER_NEED_TRAVERSE); however, since 1039 * path->should_be_locked is not set yet, we might have unlocked and 1040 * then failed to relock a path - that's fine. 1041 */ 1042 err: 1043 bch2_btree_cache_cannibalize_unlock(trans); 1044 1045 trans->in_traverse_all = false; 1046 1047 trace_and_count(c, trans_traverse_all, trans, trace_ip); 1048 return ret; 1049 } 1050 1051 static inline bool btree_path_check_pos_in_node(struct btree_path *path, 1052 unsigned l, int check_pos) 1053 { 1054 if (check_pos < 0 && btree_path_pos_before_node(path, path->l[l].b)) 1055 return false; 1056 if (check_pos > 0 && btree_path_pos_after_node(path, path->l[l].b)) 1057 return false; 1058 return true; 1059 } 1060 1061 static inline bool btree_path_good_node(struct btree_trans *trans, 1062 struct btree_path *path, 1063 unsigned l, int check_pos) 1064 { 1065 return is_btree_node(path, l) && 1066 bch2_btree_node_relock(trans, path, l) && 1067 btree_path_check_pos_in_node(path, l, check_pos); 1068 } 1069 1070 static void btree_path_set_level_down(struct btree_trans *trans, 1071 struct btree_path *path, 1072 unsigned new_level) 1073 { 1074 unsigned l; 1075 1076 path->level = new_level; 1077 1078 for (l = path->level + 1; l < BTREE_MAX_DEPTH; l++) 1079 if (btree_lock_want(path, l) == BTREE_NODE_UNLOCKED) 1080 btree_node_unlock(trans, path, l); 1081 1082 btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE); 1083 bch2_btree_path_verify(trans, path); 1084 } 1085 1086 static noinline unsigned __btree_path_up_until_good_node(struct btree_trans *trans, 1087 struct btree_path *path, 1088 int check_pos) 1089 { 1090 unsigned i, l = path->level; 1091 again: 1092 while (btree_path_node(path, l) && 1093 !btree_path_good_node(trans, path, l, check_pos)) 1094 __btree_path_set_level_up(trans, path, l++); 1095 1096 /* If we need intent locks, take them too: */ 1097 for (i = l + 1; 1098 i < path->locks_want && btree_path_node(path, i); 1099 i++) 1100 if (!bch2_btree_node_relock(trans, path, i)) { 1101 while (l <= i) 1102 __btree_path_set_level_up(trans, path, l++); 1103 goto again; 1104 } 1105 1106 return l; 1107 } 1108 1109 static inline unsigned btree_path_up_until_good_node(struct btree_trans *trans, 1110 struct btree_path *path, 1111 int check_pos) 1112 { 1113 return likely(btree_node_locked(path, path->level) && 1114 btree_path_check_pos_in_node(path, path->level, check_pos)) 1115 ? path->level 1116 : __btree_path_up_until_good_node(trans, path, check_pos); 1117 } 1118 1119 /* 1120 * This is the main state machine for walking down the btree - walks down to a 1121 * specified depth 1122 * 1123 * Returns 0 on success, -EIO on error (error reading in a btree node). 1124 * 1125 * On error, caller (peek_node()/peek_key()) must return NULL; the error is 1126 * stashed in the iterator and returned from bch2_trans_exit(). 1127 */ 1128 int bch2_btree_path_traverse_one(struct btree_trans *trans, 1129 btree_path_idx_t path_idx, 1130 unsigned flags, 1131 unsigned long trace_ip) 1132 { 1133 struct btree_path *path = &trans->paths[path_idx]; 1134 unsigned depth_want = path->level; 1135 int ret = -((int) trans->restarted); 1136 1137 if (unlikely(ret)) 1138 goto out; 1139 1140 if (unlikely(!trans->srcu_held)) 1141 bch2_trans_srcu_lock(trans); 1142 1143 /* 1144 * Ensure we obey path->should_be_locked: if it's set, we can't unlock 1145 * and re-traverse the path without a transaction restart: 1146 */ 1147 if (path->should_be_locked) { 1148 ret = bch2_btree_path_relock(trans, path, trace_ip); 1149 goto out; 1150 } 1151 1152 if (path->cached) { 1153 ret = bch2_btree_path_traverse_cached(trans, path, flags); 1154 goto out; 1155 } 1156 1157 path = &trans->paths[path_idx]; 1158 1159 if (unlikely(path->level >= BTREE_MAX_DEPTH)) 1160 goto out_uptodate; 1161 1162 path->level = btree_path_up_until_good_node(trans, path, 0); 1163 unsigned max_level = path->level; 1164 1165 EBUG_ON(btree_path_node(path, path->level) && 1166 !btree_node_locked(path, path->level)); 1167 1168 /* 1169 * Note: path->nodes[path->level] may be temporarily NULL here - that 1170 * would indicate to other code that we got to the end of the btree, 1171 * here it indicates that relocking the root failed - it's critical that 1172 * btree_path_lock_root() comes next and that it can't fail 1173 */ 1174 while (path->level > depth_want) { 1175 ret = btree_path_node(path, path->level) 1176 ? btree_path_down(trans, path, flags, trace_ip) 1177 : btree_path_lock_root(trans, path, depth_want, trace_ip); 1178 if (unlikely(ret)) { 1179 if (ret == 1) { 1180 /* 1181 * No nodes at this level - got to the end of 1182 * the btree: 1183 */ 1184 ret = 0; 1185 goto out; 1186 } 1187 1188 __bch2_btree_path_unlock(trans, path); 1189 path->level = depth_want; 1190 path->l[path->level].b = ERR_PTR(ret); 1191 goto out; 1192 } 1193 } 1194 1195 if (unlikely(max_level > path->level)) { 1196 struct btree_path *linked; 1197 unsigned iter; 1198 1199 trans_for_each_path_with_node(trans, path_l(path)->b, linked, iter) 1200 for (unsigned j = path->level + 1; j < max_level; j++) 1201 linked->l[j] = path->l[j]; 1202 } 1203 1204 out_uptodate: 1205 path->uptodate = BTREE_ITER_UPTODATE; 1206 out: 1207 if (bch2_err_matches(ret, BCH_ERR_transaction_restart) != !!trans->restarted) 1208 panic("ret %s (%i) trans->restarted %s (%i)\n", 1209 bch2_err_str(ret), ret, 1210 bch2_err_str(trans->restarted), trans->restarted); 1211 bch2_btree_path_verify(trans, path); 1212 return ret; 1213 } 1214 1215 static inline void btree_path_copy(struct btree_trans *trans, struct btree_path *dst, 1216 struct btree_path *src) 1217 { 1218 unsigned i, offset = offsetof(struct btree_path, pos); 1219 1220 memcpy((void *) dst + offset, 1221 (void *) src + offset, 1222 sizeof(struct btree_path) - offset); 1223 1224 for (i = 0; i < BTREE_MAX_DEPTH; i++) { 1225 unsigned t = btree_node_locked_type(dst, i); 1226 1227 if (t != BTREE_NODE_UNLOCKED) 1228 six_lock_increment(&dst->l[i].b->c.lock, t); 1229 } 1230 } 1231 1232 static btree_path_idx_t btree_path_clone(struct btree_trans *trans, btree_path_idx_t src, 1233 bool intent, unsigned long ip) 1234 { 1235 btree_path_idx_t new = btree_path_alloc(trans, src); 1236 btree_path_copy(trans, trans->paths + new, trans->paths + src); 1237 __btree_path_get(trans->paths + new, intent); 1238 #ifdef TRACK_PATH_ALLOCATED 1239 trans->paths[new].ip_allocated = ip; 1240 #endif 1241 return new; 1242 } 1243 1244 __flatten 1245 btree_path_idx_t __bch2_btree_path_make_mut(struct btree_trans *trans, 1246 btree_path_idx_t path, bool intent, unsigned long ip) 1247 { 1248 __btree_path_put(trans->paths + path, intent); 1249 path = btree_path_clone(trans, path, intent, ip); 1250 trans->paths[path].preserve = false; 1251 return path; 1252 } 1253 1254 btree_path_idx_t __must_check 1255 __bch2_btree_path_set_pos(struct btree_trans *trans, 1256 btree_path_idx_t path_idx, struct bpos new_pos, 1257 bool intent, unsigned long ip) 1258 { 1259 int cmp = bpos_cmp(new_pos, trans->paths[path_idx].pos); 1260 1261 bch2_trans_verify_not_in_restart(trans); 1262 EBUG_ON(!trans->paths[path_idx].ref); 1263 1264 path_idx = bch2_btree_path_make_mut(trans, path_idx, intent, ip); 1265 1266 struct btree_path *path = trans->paths + path_idx; 1267 path->pos = new_pos; 1268 trans->paths_sorted = false; 1269 1270 if (unlikely(path->cached)) { 1271 btree_node_unlock(trans, path, 0); 1272 path->l[0].b = ERR_PTR(-BCH_ERR_no_btree_node_up); 1273 btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE); 1274 goto out; 1275 } 1276 1277 unsigned level = btree_path_up_until_good_node(trans, path, cmp); 1278 1279 if (btree_path_node(path, level)) { 1280 struct btree_path_level *l = &path->l[level]; 1281 1282 BUG_ON(!btree_node_locked(path, level)); 1283 /* 1284 * We might have to skip over many keys, or just a few: try 1285 * advancing the node iterator, and if we have to skip over too 1286 * many keys just reinit it (or if we're rewinding, since that 1287 * is expensive). 1288 */ 1289 if (cmp < 0 || 1290 !btree_path_advance_to_pos(path, l, 8)) 1291 bch2_btree_node_iter_init(&l->iter, l->b, &path->pos); 1292 1293 /* 1294 * Iterators to interior nodes should always be pointed at the first non 1295 * whiteout: 1296 */ 1297 if (unlikely(level)) 1298 bch2_btree_node_iter_peek(&l->iter, l->b); 1299 } 1300 1301 if (unlikely(level != path->level)) { 1302 btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE); 1303 __bch2_btree_path_unlock(trans, path); 1304 } 1305 out: 1306 bch2_btree_path_verify(trans, path); 1307 return path_idx; 1308 } 1309 1310 /* Btree path: main interface: */ 1311 1312 static struct btree_path *have_path_at_pos(struct btree_trans *trans, struct btree_path *path) 1313 { 1314 struct btree_path *sib; 1315 1316 sib = prev_btree_path(trans, path); 1317 if (sib && !btree_path_cmp(sib, path)) 1318 return sib; 1319 1320 sib = next_btree_path(trans, path); 1321 if (sib && !btree_path_cmp(sib, path)) 1322 return sib; 1323 1324 return NULL; 1325 } 1326 1327 static struct btree_path *have_node_at_pos(struct btree_trans *trans, struct btree_path *path) 1328 { 1329 struct btree_path *sib; 1330 1331 sib = prev_btree_path(trans, path); 1332 if (sib && sib->level == path->level && path_l(sib)->b == path_l(path)->b) 1333 return sib; 1334 1335 sib = next_btree_path(trans, path); 1336 if (sib && sib->level == path->level && path_l(sib)->b == path_l(path)->b) 1337 return sib; 1338 1339 return NULL; 1340 } 1341 1342 static inline void __bch2_path_free(struct btree_trans *trans, btree_path_idx_t path) 1343 { 1344 __bch2_btree_path_unlock(trans, trans->paths + path); 1345 btree_path_list_remove(trans, trans->paths + path); 1346 __clear_bit(path, trans->paths_allocated); 1347 } 1348 1349 static bool bch2_btree_path_can_relock(struct btree_trans *trans, struct btree_path *path) 1350 { 1351 unsigned l = path->level; 1352 1353 do { 1354 if (!btree_path_node(path, l)) 1355 break; 1356 1357 if (!is_btree_node(path, l)) 1358 return false; 1359 1360 if (path->l[l].lock_seq != path->l[l].b->c.lock.seq) 1361 return false; 1362 1363 l++; 1364 } while (l < path->locks_want); 1365 1366 return true; 1367 } 1368 1369 void bch2_path_put(struct btree_trans *trans, btree_path_idx_t path_idx, bool intent) 1370 { 1371 struct btree_path *path = trans->paths + path_idx, *dup; 1372 1373 if (!__btree_path_put(path, intent)) 1374 return; 1375 1376 dup = path->preserve 1377 ? have_path_at_pos(trans, path) 1378 : have_node_at_pos(trans, path); 1379 1380 if (!dup && !(!path->preserve && !is_btree_node(path, path->level))) 1381 return; 1382 1383 if (path->should_be_locked && !trans->restarted) { 1384 if (!dup) 1385 return; 1386 1387 if (!(trans->locked 1388 ? bch2_btree_path_relock_norestart(trans, dup) 1389 : bch2_btree_path_can_relock(trans, dup))) 1390 return; 1391 } 1392 1393 if (dup) { 1394 dup->preserve |= path->preserve; 1395 dup->should_be_locked |= path->should_be_locked; 1396 } 1397 1398 __bch2_path_free(trans, path_idx); 1399 } 1400 1401 static void bch2_path_put_nokeep(struct btree_trans *trans, btree_path_idx_t path, 1402 bool intent) 1403 { 1404 if (!__btree_path_put(trans->paths + path, intent)) 1405 return; 1406 1407 __bch2_path_free(trans, path); 1408 } 1409 1410 void __noreturn bch2_trans_restart_error(struct btree_trans *trans, u32 restart_count) 1411 { 1412 panic("trans->restart_count %u, should be %u, last restarted by %pS\n", 1413 trans->restart_count, restart_count, 1414 (void *) trans->last_begin_ip); 1415 } 1416 1417 void __noreturn bch2_trans_in_restart_error(struct btree_trans *trans) 1418 { 1419 panic("in transaction restart: %s, last restarted by %pS\n", 1420 bch2_err_str(trans->restarted), 1421 (void *) trans->last_restarted_ip); 1422 } 1423 1424 void __noreturn bch2_trans_unlocked_error(struct btree_trans *trans) 1425 { 1426 panic("trans should be locked, unlocked by %pS\n", 1427 (void *) trans->last_unlock_ip); 1428 } 1429 1430 noinline __cold 1431 void bch2_trans_updates_to_text(struct printbuf *buf, struct btree_trans *trans) 1432 { 1433 prt_printf(buf, "transaction updates for %s journal seq %llu\n", 1434 trans->fn, trans->journal_res.seq); 1435 printbuf_indent_add(buf, 2); 1436 1437 trans_for_each_update(trans, i) { 1438 struct bkey_s_c old = { &i->old_k, i->old_v }; 1439 1440 prt_printf(buf, "update: btree=%s cached=%u %pS\n", 1441 bch2_btree_id_str(i->btree_id), 1442 i->cached, 1443 (void *) i->ip_allocated); 1444 1445 prt_printf(buf, " old "); 1446 bch2_bkey_val_to_text(buf, trans->c, old); 1447 prt_newline(buf); 1448 1449 prt_printf(buf, " new "); 1450 bch2_bkey_val_to_text(buf, trans->c, bkey_i_to_s_c(i->k)); 1451 prt_newline(buf); 1452 } 1453 1454 for (struct jset_entry *e = trans->journal_entries; 1455 e != btree_trans_journal_entries_top(trans); 1456 e = vstruct_next(e)) 1457 bch2_journal_entry_to_text(buf, trans->c, e); 1458 1459 printbuf_indent_sub(buf, 2); 1460 } 1461 1462 noinline __cold 1463 void bch2_dump_trans_updates(struct btree_trans *trans) 1464 { 1465 struct printbuf buf = PRINTBUF; 1466 1467 bch2_trans_updates_to_text(&buf, trans); 1468 bch2_print_string_as_lines(KERN_ERR, buf.buf); 1469 printbuf_exit(&buf); 1470 } 1471 1472 static void bch2_btree_path_to_text_short(struct printbuf *out, struct btree_trans *trans, btree_path_idx_t path_idx) 1473 { 1474 struct btree_path *path = trans->paths + path_idx; 1475 1476 prt_printf(out, "path: idx %2u ref %u:%u %c %c %c btree=%s l=%u pos ", 1477 path_idx, path->ref, path->intent_ref, 1478 path->preserve ? 'P' : ' ', 1479 path->should_be_locked ? 'S' : ' ', 1480 path->cached ? 'C' : 'B', 1481 bch2_btree_id_str(path->btree_id), 1482 path->level); 1483 bch2_bpos_to_text(out, path->pos); 1484 1485 #ifdef TRACK_PATH_ALLOCATED 1486 prt_printf(out, " %pS", (void *) path->ip_allocated); 1487 #endif 1488 } 1489 1490 static const char *btree_node_locked_str(enum btree_node_locked_type t) 1491 { 1492 switch (t) { 1493 case BTREE_NODE_UNLOCKED: 1494 return "unlocked"; 1495 case BTREE_NODE_READ_LOCKED: 1496 return "read"; 1497 case BTREE_NODE_INTENT_LOCKED: 1498 return "intent"; 1499 case BTREE_NODE_WRITE_LOCKED: 1500 return "write"; 1501 default: 1502 return NULL; 1503 } 1504 } 1505 1506 void bch2_btree_path_to_text(struct printbuf *out, struct btree_trans *trans, btree_path_idx_t path_idx) 1507 { 1508 bch2_btree_path_to_text_short(out, trans, path_idx); 1509 1510 struct btree_path *path = trans->paths + path_idx; 1511 1512 prt_printf(out, " uptodate %u locks_want %u", path->uptodate, path->locks_want); 1513 prt_newline(out); 1514 1515 printbuf_indent_add(out, 2); 1516 for (unsigned l = 0; l < BTREE_MAX_DEPTH; l++) { 1517 prt_printf(out, "l=%u locks %s seq %u node ", l, 1518 btree_node_locked_str(btree_node_locked_type(path, l)), 1519 path->l[l].lock_seq); 1520 1521 int ret = PTR_ERR_OR_ZERO(path->l[l].b); 1522 if (ret) 1523 prt_str(out, bch2_err_str(ret)); 1524 else 1525 prt_printf(out, "%px", path->l[l].b); 1526 prt_newline(out); 1527 } 1528 printbuf_indent_sub(out, 2); 1529 } 1530 1531 static noinline __cold 1532 void __bch2_trans_paths_to_text(struct printbuf *out, struct btree_trans *trans, 1533 bool nosort) 1534 { 1535 struct trans_for_each_path_inorder_iter iter; 1536 1537 if (!nosort) 1538 btree_trans_sort_paths(trans); 1539 1540 trans_for_each_path_idx_inorder(trans, iter) { 1541 bch2_btree_path_to_text_short(out, trans, iter.path_idx); 1542 prt_newline(out); 1543 } 1544 } 1545 1546 noinline __cold 1547 void bch2_trans_paths_to_text(struct printbuf *out, struct btree_trans *trans) 1548 { 1549 __bch2_trans_paths_to_text(out, trans, false); 1550 } 1551 1552 static noinline __cold 1553 void __bch2_dump_trans_paths_updates(struct btree_trans *trans, bool nosort) 1554 { 1555 struct printbuf buf = PRINTBUF; 1556 1557 __bch2_trans_paths_to_text(&buf, trans, nosort); 1558 bch2_trans_updates_to_text(&buf, trans); 1559 1560 bch2_print_string_as_lines(KERN_ERR, buf.buf); 1561 printbuf_exit(&buf); 1562 } 1563 1564 noinline __cold 1565 void bch2_dump_trans_paths_updates(struct btree_trans *trans) 1566 { 1567 __bch2_dump_trans_paths_updates(trans, false); 1568 } 1569 1570 noinline __cold 1571 static void bch2_trans_update_max_paths(struct btree_trans *trans) 1572 { 1573 struct btree_transaction_stats *s = btree_trans_stats(trans); 1574 struct printbuf buf = PRINTBUF; 1575 size_t nr = bitmap_weight(trans->paths_allocated, trans->nr_paths); 1576 1577 bch2_trans_paths_to_text(&buf, trans); 1578 1579 if (!buf.allocation_failure) { 1580 mutex_lock(&s->lock); 1581 if (nr > s->nr_max_paths) { 1582 s->nr_max_paths = nr; 1583 swap(s->max_paths_text, buf.buf); 1584 } 1585 mutex_unlock(&s->lock); 1586 } 1587 1588 printbuf_exit(&buf); 1589 1590 trans->nr_paths_max = nr; 1591 } 1592 1593 noinline __cold 1594 int __bch2_btree_trans_too_many_iters(struct btree_trans *trans) 1595 { 1596 if (trace_trans_restart_too_many_iters_enabled()) { 1597 struct printbuf buf = PRINTBUF; 1598 1599 bch2_trans_paths_to_text(&buf, trans); 1600 trace_trans_restart_too_many_iters(trans, _THIS_IP_, buf.buf); 1601 printbuf_exit(&buf); 1602 } 1603 1604 count_event(trans->c, trans_restart_too_many_iters); 1605 1606 return btree_trans_restart(trans, BCH_ERR_transaction_restart_too_many_iters); 1607 } 1608 1609 static noinline void btree_path_overflow(struct btree_trans *trans) 1610 { 1611 bch2_dump_trans_paths_updates(trans); 1612 bch_err(trans->c, "trans path overflow"); 1613 } 1614 1615 static noinline void btree_paths_realloc(struct btree_trans *trans) 1616 { 1617 unsigned nr = trans->nr_paths * 2; 1618 1619 void *p = kvzalloc(BITS_TO_LONGS(nr) * sizeof(unsigned long) + 1620 sizeof(struct btree_trans_paths) + 1621 nr * sizeof(struct btree_path) + 1622 nr * sizeof(btree_path_idx_t) + 8 + 1623 nr * sizeof(struct btree_insert_entry), GFP_KERNEL|__GFP_NOFAIL); 1624 1625 unsigned long *paths_allocated = p; 1626 memcpy(paths_allocated, trans->paths_allocated, BITS_TO_LONGS(trans->nr_paths) * sizeof(unsigned long)); 1627 p += BITS_TO_LONGS(nr) * sizeof(unsigned long); 1628 1629 p += sizeof(struct btree_trans_paths); 1630 struct btree_path *paths = p; 1631 *trans_paths_nr(paths) = nr; 1632 memcpy(paths, trans->paths, trans->nr_paths * sizeof(struct btree_path)); 1633 p += nr * sizeof(struct btree_path); 1634 1635 btree_path_idx_t *sorted = p; 1636 memcpy(sorted, trans->sorted, trans->nr_sorted * sizeof(btree_path_idx_t)); 1637 p += nr * sizeof(btree_path_idx_t) + 8; 1638 1639 struct btree_insert_entry *updates = p; 1640 memcpy(updates, trans->updates, trans->nr_paths * sizeof(struct btree_insert_entry)); 1641 1642 unsigned long *old = trans->paths_allocated; 1643 1644 rcu_assign_pointer(trans->paths_allocated, paths_allocated); 1645 rcu_assign_pointer(trans->paths, paths); 1646 rcu_assign_pointer(trans->sorted, sorted); 1647 rcu_assign_pointer(trans->updates, updates); 1648 1649 trans->nr_paths = nr; 1650 1651 if (old != trans->_paths_allocated) 1652 kfree_rcu_mightsleep(old); 1653 } 1654 1655 static inline btree_path_idx_t btree_path_alloc(struct btree_trans *trans, 1656 btree_path_idx_t pos) 1657 { 1658 btree_path_idx_t idx = find_first_zero_bit(trans->paths_allocated, trans->nr_paths); 1659 1660 if (unlikely(idx == trans->nr_paths)) { 1661 if (trans->nr_paths == BTREE_ITER_MAX) { 1662 btree_path_overflow(trans); 1663 return 0; 1664 } 1665 1666 btree_paths_realloc(trans); 1667 } 1668 1669 /* 1670 * Do this before marking the new path as allocated, since it won't be 1671 * initialized yet: 1672 */ 1673 if (unlikely(idx > trans->nr_paths_max)) 1674 bch2_trans_update_max_paths(trans); 1675 1676 __set_bit(idx, trans->paths_allocated); 1677 1678 struct btree_path *path = &trans->paths[idx]; 1679 path->ref = 0; 1680 path->intent_ref = 0; 1681 path->nodes_locked = 0; 1682 1683 btree_path_list_add(trans, pos, idx); 1684 trans->paths_sorted = false; 1685 return idx; 1686 } 1687 1688 btree_path_idx_t bch2_path_get(struct btree_trans *trans, 1689 enum btree_id btree_id, struct bpos pos, 1690 unsigned locks_want, unsigned level, 1691 unsigned flags, unsigned long ip) 1692 { 1693 struct btree_path *path; 1694 bool cached = flags & BTREE_ITER_cached; 1695 bool intent = flags & BTREE_ITER_intent; 1696 struct trans_for_each_path_inorder_iter iter; 1697 btree_path_idx_t path_pos = 0, path_idx; 1698 1699 bch2_trans_verify_not_unlocked(trans); 1700 bch2_trans_verify_not_in_restart(trans); 1701 bch2_trans_verify_locks(trans); 1702 1703 btree_trans_sort_paths(trans); 1704 1705 trans_for_each_path_inorder(trans, path, iter) { 1706 if (__btree_path_cmp(path, 1707 btree_id, 1708 cached, 1709 pos, 1710 level) > 0) 1711 break; 1712 1713 path_pos = iter.path_idx; 1714 } 1715 1716 if (path_pos && 1717 trans->paths[path_pos].cached == cached && 1718 trans->paths[path_pos].btree_id == btree_id && 1719 trans->paths[path_pos].level == level) { 1720 __btree_path_get(trans->paths + path_pos, intent); 1721 path_idx = bch2_btree_path_set_pos(trans, path_pos, pos, intent, ip); 1722 path = trans->paths + path_idx; 1723 } else { 1724 path_idx = btree_path_alloc(trans, path_pos); 1725 path = trans->paths + path_idx; 1726 1727 __btree_path_get(path, intent); 1728 path->pos = pos; 1729 path->btree_id = btree_id; 1730 path->cached = cached; 1731 path->uptodate = BTREE_ITER_NEED_TRAVERSE; 1732 path->should_be_locked = false; 1733 path->level = level; 1734 path->locks_want = locks_want; 1735 path->nodes_locked = 0; 1736 for (unsigned i = 0; i < ARRAY_SIZE(path->l); i++) 1737 path->l[i].b = ERR_PTR(-BCH_ERR_no_btree_node_init); 1738 #ifdef TRACK_PATH_ALLOCATED 1739 path->ip_allocated = ip; 1740 #endif 1741 trans->paths_sorted = false; 1742 } 1743 1744 if (!(flags & BTREE_ITER_nopreserve)) 1745 path->preserve = true; 1746 1747 if (path->intent_ref) 1748 locks_want = max(locks_want, level + 1); 1749 1750 /* 1751 * If the path has locks_want greater than requested, we don't downgrade 1752 * it here - on transaction restart because btree node split needs to 1753 * upgrade locks, we might be putting/getting the iterator again. 1754 * Downgrading iterators only happens via bch2_trans_downgrade(), after 1755 * a successful transaction commit. 1756 */ 1757 1758 locks_want = min(locks_want, BTREE_MAX_DEPTH); 1759 if (locks_want > path->locks_want) 1760 bch2_btree_path_upgrade_noupgrade_sibs(trans, path, locks_want, NULL); 1761 1762 return path_idx; 1763 } 1764 1765 btree_path_idx_t bch2_path_get_unlocked_mut(struct btree_trans *trans, 1766 enum btree_id btree_id, 1767 unsigned level, 1768 struct bpos pos) 1769 { 1770 btree_path_idx_t path_idx = bch2_path_get(trans, btree_id, pos, level + 1, level, 1771 BTREE_ITER_nopreserve| 1772 BTREE_ITER_intent, _RET_IP_); 1773 path_idx = bch2_btree_path_make_mut(trans, path_idx, true, _RET_IP_); 1774 1775 struct btree_path *path = trans->paths + path_idx; 1776 bch2_btree_path_downgrade(trans, path); 1777 __bch2_btree_path_unlock(trans, path); 1778 return path_idx; 1779 } 1780 1781 struct bkey_s_c bch2_btree_path_peek_slot(struct btree_path *path, struct bkey *u) 1782 { 1783 1784 struct btree_path_level *l = path_l(path); 1785 struct bkey_packed *_k; 1786 struct bkey_s_c k; 1787 1788 if (unlikely(!l->b)) 1789 return bkey_s_c_null; 1790 1791 EBUG_ON(path->uptodate != BTREE_ITER_UPTODATE); 1792 EBUG_ON(!btree_node_locked(path, path->level)); 1793 1794 if (!path->cached) { 1795 _k = bch2_btree_node_iter_peek_all(&l->iter, l->b); 1796 k = _k ? bkey_disassemble(l->b, _k, u) : bkey_s_c_null; 1797 1798 EBUG_ON(k.k && bkey_deleted(k.k) && bpos_eq(k.k->p, path->pos)); 1799 1800 if (!k.k || !bpos_eq(path->pos, k.k->p)) 1801 goto hole; 1802 } else { 1803 struct bkey_cached *ck = (void *) path->l[0].b; 1804 1805 EBUG_ON(ck && 1806 (path->btree_id != ck->key.btree_id || 1807 !bkey_eq(path->pos, ck->key.pos))); 1808 if (!ck || !ck->valid) 1809 return bkey_s_c_null; 1810 1811 *u = ck->k->k; 1812 k = bkey_i_to_s_c(ck->k); 1813 } 1814 1815 return k; 1816 hole: 1817 bkey_init(u); 1818 u->p = path->pos; 1819 return (struct bkey_s_c) { u, NULL }; 1820 } 1821 1822 1823 void bch2_set_btree_iter_dontneed(struct btree_iter *iter) 1824 { 1825 struct btree_trans *trans = iter->trans; 1826 1827 if (!iter->path || trans->restarted) 1828 return; 1829 1830 struct btree_path *path = btree_iter_path(trans, iter); 1831 path->preserve = false; 1832 if (path->ref == 1) 1833 path->should_be_locked = false; 1834 } 1835 /* Btree iterators: */ 1836 1837 int __must_check 1838 __bch2_btree_iter_traverse(struct btree_iter *iter) 1839 { 1840 return bch2_btree_path_traverse(iter->trans, iter->path, iter->flags); 1841 } 1842 1843 int __must_check 1844 bch2_btree_iter_traverse(struct btree_iter *iter) 1845 { 1846 struct btree_trans *trans = iter->trans; 1847 int ret; 1848 1849 bch2_trans_verify_not_unlocked(trans); 1850 1851 iter->path = bch2_btree_path_set_pos(trans, iter->path, 1852 btree_iter_search_key(iter), 1853 iter->flags & BTREE_ITER_intent, 1854 btree_iter_ip_allocated(iter)); 1855 1856 ret = bch2_btree_path_traverse(iter->trans, iter->path, iter->flags); 1857 if (ret) 1858 return ret; 1859 1860 struct btree_path *path = btree_iter_path(trans, iter); 1861 if (btree_path_node(path, path->level)) 1862 btree_path_set_should_be_locked(path); 1863 return 0; 1864 } 1865 1866 /* Iterate across nodes (leaf and interior nodes) */ 1867 1868 struct btree *bch2_btree_iter_peek_node(struct btree_iter *iter) 1869 { 1870 struct btree_trans *trans = iter->trans; 1871 struct btree *b = NULL; 1872 int ret; 1873 1874 EBUG_ON(trans->paths[iter->path].cached); 1875 bch2_btree_iter_verify(iter); 1876 1877 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags); 1878 if (ret) 1879 goto err; 1880 1881 struct btree_path *path = btree_iter_path(trans, iter); 1882 b = btree_path_node(path, path->level); 1883 if (!b) 1884 goto out; 1885 1886 BUG_ON(bpos_lt(b->key.k.p, iter->pos)); 1887 1888 bkey_init(&iter->k); 1889 iter->k.p = iter->pos = b->key.k.p; 1890 1891 iter->path = bch2_btree_path_set_pos(trans, iter->path, b->key.k.p, 1892 iter->flags & BTREE_ITER_intent, 1893 btree_iter_ip_allocated(iter)); 1894 btree_path_set_should_be_locked(btree_iter_path(trans, iter)); 1895 out: 1896 bch2_btree_iter_verify_entry_exit(iter); 1897 bch2_btree_iter_verify(iter); 1898 1899 return b; 1900 err: 1901 b = ERR_PTR(ret); 1902 goto out; 1903 } 1904 1905 struct btree *bch2_btree_iter_peek_node_and_restart(struct btree_iter *iter) 1906 { 1907 struct btree *b; 1908 1909 while (b = bch2_btree_iter_peek_node(iter), 1910 bch2_err_matches(PTR_ERR_OR_ZERO(b), BCH_ERR_transaction_restart)) 1911 bch2_trans_begin(iter->trans); 1912 1913 return b; 1914 } 1915 1916 struct btree *bch2_btree_iter_next_node(struct btree_iter *iter) 1917 { 1918 struct btree_trans *trans = iter->trans; 1919 struct btree *b = NULL; 1920 int ret; 1921 1922 EBUG_ON(trans->paths[iter->path].cached); 1923 bch2_trans_verify_not_in_restart(trans); 1924 bch2_btree_iter_verify(iter); 1925 1926 struct btree_path *path = btree_iter_path(trans, iter); 1927 1928 /* already at end? */ 1929 if (!btree_path_node(path, path->level)) 1930 return NULL; 1931 1932 /* got to end? */ 1933 if (!btree_path_node(path, path->level + 1)) { 1934 btree_path_set_level_up(trans, path); 1935 return NULL; 1936 } 1937 1938 if (!bch2_btree_node_relock(trans, path, path->level + 1)) { 1939 __bch2_btree_path_unlock(trans, path); 1940 path->l[path->level].b = ERR_PTR(-BCH_ERR_no_btree_node_relock); 1941 path->l[path->level + 1].b = ERR_PTR(-BCH_ERR_no_btree_node_relock); 1942 btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE); 1943 trace_and_count(trans->c, trans_restart_relock_next_node, trans, _THIS_IP_, path); 1944 ret = btree_trans_restart(trans, BCH_ERR_transaction_restart_relock); 1945 goto err; 1946 } 1947 1948 b = btree_path_node(path, path->level + 1); 1949 1950 if (bpos_eq(iter->pos, b->key.k.p)) { 1951 __btree_path_set_level_up(trans, path, path->level++); 1952 } else { 1953 if (btree_lock_want(path, path->level + 1) == BTREE_NODE_UNLOCKED) 1954 btree_node_unlock(trans, path, path->level + 1); 1955 1956 /* 1957 * Haven't gotten to the end of the parent node: go back down to 1958 * the next child node 1959 */ 1960 iter->path = bch2_btree_path_set_pos(trans, iter->path, 1961 bpos_successor(iter->pos), 1962 iter->flags & BTREE_ITER_intent, 1963 btree_iter_ip_allocated(iter)); 1964 1965 path = btree_iter_path(trans, iter); 1966 btree_path_set_level_down(trans, path, iter->min_depth); 1967 1968 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags); 1969 if (ret) 1970 goto err; 1971 1972 path = btree_iter_path(trans, iter); 1973 b = path->l[path->level].b; 1974 } 1975 1976 bkey_init(&iter->k); 1977 iter->k.p = iter->pos = b->key.k.p; 1978 1979 iter->path = bch2_btree_path_set_pos(trans, iter->path, b->key.k.p, 1980 iter->flags & BTREE_ITER_intent, 1981 btree_iter_ip_allocated(iter)); 1982 btree_path_set_should_be_locked(btree_iter_path(trans, iter)); 1983 EBUG_ON(btree_iter_path(trans, iter)->uptodate); 1984 out: 1985 bch2_btree_iter_verify_entry_exit(iter); 1986 bch2_btree_iter_verify(iter); 1987 1988 return b; 1989 err: 1990 b = ERR_PTR(ret); 1991 goto out; 1992 } 1993 1994 /* Iterate across keys (in leaf nodes only) */ 1995 1996 inline bool bch2_btree_iter_advance(struct btree_iter *iter) 1997 { 1998 struct bpos pos = iter->k.p; 1999 bool ret = !(iter->flags & BTREE_ITER_all_snapshots 2000 ? bpos_eq(pos, SPOS_MAX) 2001 : bkey_eq(pos, SPOS_MAX)); 2002 2003 if (ret && !(iter->flags & BTREE_ITER_is_extents)) 2004 pos = bkey_successor(iter, pos); 2005 bch2_btree_iter_set_pos(iter, pos); 2006 return ret; 2007 } 2008 2009 inline bool bch2_btree_iter_rewind(struct btree_iter *iter) 2010 { 2011 struct bpos pos = bkey_start_pos(&iter->k); 2012 bool ret = !(iter->flags & BTREE_ITER_all_snapshots 2013 ? bpos_eq(pos, POS_MIN) 2014 : bkey_eq(pos, POS_MIN)); 2015 2016 if (ret && !(iter->flags & BTREE_ITER_is_extents)) 2017 pos = bkey_predecessor(iter, pos); 2018 bch2_btree_iter_set_pos(iter, pos); 2019 return ret; 2020 } 2021 2022 static noinline 2023 void bch2_btree_trans_peek_prev_updates(struct btree_trans *trans, struct btree_iter *iter, 2024 struct bkey_s_c *k) 2025 { 2026 struct bpos end = path_l(btree_iter_path(trans, iter))->b->data->min_key; 2027 2028 trans_for_each_update(trans, i) 2029 if (!i->key_cache_already_flushed && 2030 i->btree_id == iter->btree_id && 2031 bpos_le(i->k->k.p, iter->pos) && 2032 bpos_ge(i->k->k.p, k->k ? k->k->p : end)) { 2033 iter->k = i->k->k; 2034 *k = bkey_i_to_s_c(i->k); 2035 } 2036 } 2037 2038 static noinline 2039 void bch2_btree_trans_peek_updates(struct btree_trans *trans, struct btree_iter *iter, 2040 struct bkey_s_c *k) 2041 { 2042 struct btree_path *path = btree_iter_path(trans, iter); 2043 struct bpos end = path_l(path)->b->key.k.p; 2044 2045 trans_for_each_update(trans, i) 2046 if (!i->key_cache_already_flushed && 2047 i->btree_id == iter->btree_id && 2048 bpos_ge(i->k->k.p, path->pos) && 2049 bpos_le(i->k->k.p, k->k ? k->k->p : end)) { 2050 iter->k = i->k->k; 2051 *k = bkey_i_to_s_c(i->k); 2052 } 2053 } 2054 2055 static noinline 2056 void bch2_btree_trans_peek_slot_updates(struct btree_trans *trans, struct btree_iter *iter, 2057 struct bkey_s_c *k) 2058 { 2059 trans_for_each_update(trans, i) 2060 if (!i->key_cache_already_flushed && 2061 i->btree_id == iter->btree_id && 2062 bpos_eq(i->k->k.p, iter->pos)) { 2063 iter->k = i->k->k; 2064 *k = bkey_i_to_s_c(i->k); 2065 } 2066 } 2067 2068 static struct bkey_i *bch2_btree_journal_peek(struct btree_trans *trans, 2069 struct btree_iter *iter, 2070 struct bpos end_pos) 2071 { 2072 struct btree_path *path = btree_iter_path(trans, iter); 2073 2074 return bch2_journal_keys_peek_upto(trans->c, iter->btree_id, 2075 path->level, 2076 path->pos, 2077 end_pos, 2078 &iter->journal_idx); 2079 } 2080 2081 static noinline 2082 struct bkey_s_c btree_trans_peek_slot_journal(struct btree_trans *trans, 2083 struct btree_iter *iter) 2084 { 2085 struct btree_path *path = btree_iter_path(trans, iter); 2086 struct bkey_i *k = bch2_btree_journal_peek(trans, iter, path->pos); 2087 2088 if (k) { 2089 iter->k = k->k; 2090 return bkey_i_to_s_c(k); 2091 } else { 2092 return bkey_s_c_null; 2093 } 2094 } 2095 2096 static noinline 2097 struct bkey_s_c btree_trans_peek_journal(struct btree_trans *trans, 2098 struct btree_iter *iter, 2099 struct bkey_s_c k) 2100 { 2101 struct btree_path *path = btree_iter_path(trans, iter); 2102 struct bkey_i *next_journal = 2103 bch2_btree_journal_peek(trans, iter, 2104 k.k ? k.k->p : path_l(path)->b->key.k.p); 2105 2106 if (next_journal) { 2107 iter->k = next_journal->k; 2108 k = bkey_i_to_s_c(next_journal); 2109 } 2110 2111 return k; 2112 } 2113 2114 /* 2115 * Checks btree key cache for key at iter->pos and returns it if present, or 2116 * bkey_s_c_null: 2117 */ 2118 static noinline 2119 struct bkey_s_c btree_trans_peek_key_cache(struct btree_iter *iter, struct bpos pos) 2120 { 2121 struct btree_trans *trans = iter->trans; 2122 struct bch_fs *c = trans->c; 2123 struct bkey u; 2124 struct bkey_s_c k; 2125 int ret; 2126 2127 bch2_trans_verify_not_in_restart(trans); 2128 bch2_trans_verify_not_unlocked(trans); 2129 2130 if ((iter->flags & BTREE_ITER_key_cache_fill) && 2131 bpos_eq(iter->pos, pos)) 2132 return bkey_s_c_null; 2133 2134 if (!bch2_btree_key_cache_find(c, iter->btree_id, pos)) 2135 return bkey_s_c_null; 2136 2137 if (!iter->key_cache_path) 2138 iter->key_cache_path = bch2_path_get(trans, iter->btree_id, pos, 2139 iter->flags & BTREE_ITER_intent, 0, 2140 iter->flags|BTREE_ITER_cached| 2141 BTREE_ITER_cached_nofill, 2142 _THIS_IP_); 2143 2144 iter->key_cache_path = bch2_btree_path_set_pos(trans, iter->key_cache_path, pos, 2145 iter->flags & BTREE_ITER_intent, 2146 btree_iter_ip_allocated(iter)); 2147 2148 ret = bch2_btree_path_traverse(trans, iter->key_cache_path, 2149 iter->flags|BTREE_ITER_cached) ?: 2150 bch2_btree_path_relock(trans, btree_iter_path(trans, iter), _THIS_IP_); 2151 if (unlikely(ret)) 2152 return bkey_s_c_err(ret); 2153 2154 btree_path_set_should_be_locked(trans->paths + iter->key_cache_path); 2155 2156 k = bch2_btree_path_peek_slot(trans->paths + iter->key_cache_path, &u); 2157 if (k.k && !bkey_err(k)) { 2158 iter->k = u; 2159 k.k = &iter->k; 2160 } 2161 return k; 2162 } 2163 2164 static struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter, struct bpos search_key) 2165 { 2166 struct btree_trans *trans = iter->trans; 2167 struct bkey_s_c k, k2; 2168 int ret; 2169 2170 EBUG_ON(btree_iter_path(trans, iter)->cached); 2171 bch2_btree_iter_verify(iter); 2172 2173 while (1) { 2174 struct btree_path_level *l; 2175 2176 iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key, 2177 iter->flags & BTREE_ITER_intent, 2178 btree_iter_ip_allocated(iter)); 2179 2180 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags); 2181 if (unlikely(ret)) { 2182 /* ensure that iter->k is consistent with iter->pos: */ 2183 bch2_btree_iter_set_pos(iter, iter->pos); 2184 k = bkey_s_c_err(ret); 2185 goto out; 2186 } 2187 2188 struct btree_path *path = btree_iter_path(trans, iter); 2189 l = path_l(path); 2190 2191 if (unlikely(!l->b)) { 2192 /* No btree nodes at requested level: */ 2193 bch2_btree_iter_set_pos(iter, SPOS_MAX); 2194 k = bkey_s_c_null; 2195 goto out; 2196 } 2197 2198 btree_path_set_should_be_locked(path); 2199 2200 k = btree_path_level_peek_all(trans->c, l, &iter->k); 2201 2202 if (unlikely(iter->flags & BTREE_ITER_with_key_cache) && 2203 k.k && 2204 (k2 = btree_trans_peek_key_cache(iter, k.k->p)).k) { 2205 k = k2; 2206 ret = bkey_err(k); 2207 if (ret) { 2208 bch2_btree_iter_set_pos(iter, iter->pos); 2209 goto out; 2210 } 2211 } 2212 2213 if (unlikely(iter->flags & BTREE_ITER_with_journal)) 2214 k = btree_trans_peek_journal(trans, iter, k); 2215 2216 if (unlikely((iter->flags & BTREE_ITER_with_updates) && 2217 trans->nr_updates)) 2218 bch2_btree_trans_peek_updates(trans, iter, &k); 2219 2220 if (k.k && bkey_deleted(k.k)) { 2221 /* 2222 * If we've got a whiteout, and it's after the search 2223 * key, advance the search key to the whiteout instead 2224 * of just after the whiteout - it might be a btree 2225 * whiteout, with a real key at the same position, since 2226 * in the btree deleted keys sort before non deleted. 2227 */ 2228 search_key = !bpos_eq(search_key, k.k->p) 2229 ? k.k->p 2230 : bpos_successor(k.k->p); 2231 continue; 2232 } 2233 2234 if (likely(k.k)) { 2235 break; 2236 } else if (likely(!bpos_eq(l->b->key.k.p, SPOS_MAX))) { 2237 /* Advance to next leaf node: */ 2238 search_key = bpos_successor(l->b->key.k.p); 2239 } else { 2240 /* End of btree: */ 2241 bch2_btree_iter_set_pos(iter, SPOS_MAX); 2242 k = bkey_s_c_null; 2243 goto out; 2244 } 2245 } 2246 out: 2247 bch2_btree_iter_verify(iter); 2248 2249 return k; 2250 } 2251 2252 /** 2253 * bch2_btree_iter_peek_upto() - returns first key greater than or equal to 2254 * iterator's current position 2255 * @iter: iterator to peek from 2256 * @end: search limit: returns keys less than or equal to @end 2257 * 2258 * Returns: key if found, or an error extractable with bkey_err(). 2259 */ 2260 struct bkey_s_c bch2_btree_iter_peek_upto(struct btree_iter *iter, struct bpos end) 2261 { 2262 struct btree_trans *trans = iter->trans; 2263 struct bpos search_key = btree_iter_search_key(iter); 2264 struct bkey_s_c k; 2265 struct bpos iter_pos; 2266 int ret; 2267 2268 bch2_trans_verify_not_unlocked(trans); 2269 EBUG_ON((iter->flags & BTREE_ITER_filter_snapshots) && bkey_eq(end, POS_MAX)); 2270 2271 if (iter->update_path) { 2272 bch2_path_put_nokeep(trans, iter->update_path, 2273 iter->flags & BTREE_ITER_intent); 2274 iter->update_path = 0; 2275 } 2276 2277 bch2_btree_iter_verify_entry_exit(iter); 2278 2279 while (1) { 2280 k = __bch2_btree_iter_peek(iter, search_key); 2281 if (unlikely(!k.k)) 2282 goto end; 2283 if (unlikely(bkey_err(k))) 2284 goto out_no_locked; 2285 2286 /* 2287 * We need to check against @end before FILTER_SNAPSHOTS because 2288 * if we get to a different inode that requested we might be 2289 * seeing keys for a different snapshot tree that will all be 2290 * filtered out. 2291 * 2292 * But we can't do the full check here, because bkey_start_pos() 2293 * isn't monotonically increasing before FILTER_SNAPSHOTS, and 2294 * that's what we check against in extents mode: 2295 */ 2296 if (unlikely(!(iter->flags & BTREE_ITER_is_extents) 2297 ? bkey_gt(k.k->p, end) 2298 : k.k->p.inode > end.inode)) 2299 goto end; 2300 2301 if (iter->update_path && 2302 !bkey_eq(trans->paths[iter->update_path].pos, k.k->p)) { 2303 bch2_path_put_nokeep(trans, iter->update_path, 2304 iter->flags & BTREE_ITER_intent); 2305 iter->update_path = 0; 2306 } 2307 2308 if ((iter->flags & BTREE_ITER_filter_snapshots) && 2309 (iter->flags & BTREE_ITER_intent) && 2310 !(iter->flags & BTREE_ITER_is_extents) && 2311 !iter->update_path) { 2312 struct bpos pos = k.k->p; 2313 2314 if (pos.snapshot < iter->snapshot) { 2315 search_key = bpos_successor(k.k->p); 2316 continue; 2317 } 2318 2319 pos.snapshot = iter->snapshot; 2320 2321 /* 2322 * advance, same as on exit for iter->path, but only up 2323 * to snapshot 2324 */ 2325 __btree_path_get(trans->paths + iter->path, iter->flags & BTREE_ITER_intent); 2326 iter->update_path = iter->path; 2327 2328 iter->update_path = bch2_btree_path_set_pos(trans, 2329 iter->update_path, pos, 2330 iter->flags & BTREE_ITER_intent, 2331 _THIS_IP_); 2332 ret = bch2_btree_path_traverse(trans, iter->update_path, iter->flags); 2333 if (unlikely(ret)) { 2334 k = bkey_s_c_err(ret); 2335 goto out_no_locked; 2336 } 2337 } 2338 2339 /* 2340 * We can never have a key in a leaf node at POS_MAX, so 2341 * we don't have to check these successor() calls: 2342 */ 2343 if ((iter->flags & BTREE_ITER_filter_snapshots) && 2344 !bch2_snapshot_is_ancestor(trans->c, 2345 iter->snapshot, 2346 k.k->p.snapshot)) { 2347 search_key = bpos_successor(k.k->p); 2348 continue; 2349 } 2350 2351 if (bkey_whiteout(k.k) && 2352 !(iter->flags & BTREE_ITER_all_snapshots)) { 2353 search_key = bkey_successor(iter, k.k->p); 2354 continue; 2355 } 2356 2357 /* 2358 * iter->pos should be mononotically increasing, and always be 2359 * equal to the key we just returned - except extents can 2360 * straddle iter->pos: 2361 */ 2362 if (!(iter->flags & BTREE_ITER_is_extents)) 2363 iter_pos = k.k->p; 2364 else 2365 iter_pos = bkey_max(iter->pos, bkey_start_pos(k.k)); 2366 2367 if (unlikely(!(iter->flags & BTREE_ITER_is_extents) 2368 ? bkey_gt(iter_pos, end) 2369 : bkey_ge(iter_pos, end))) 2370 goto end; 2371 2372 break; 2373 } 2374 2375 iter->pos = iter_pos; 2376 2377 iter->path = bch2_btree_path_set_pos(trans, iter->path, k.k->p, 2378 iter->flags & BTREE_ITER_intent, 2379 btree_iter_ip_allocated(iter)); 2380 2381 btree_path_set_should_be_locked(btree_iter_path(trans, iter)); 2382 out_no_locked: 2383 if (iter->update_path) { 2384 ret = bch2_btree_path_relock(trans, trans->paths + iter->update_path, _THIS_IP_); 2385 if (unlikely(ret)) 2386 k = bkey_s_c_err(ret); 2387 else 2388 btree_path_set_should_be_locked(trans->paths + iter->update_path); 2389 } 2390 2391 if (!(iter->flags & BTREE_ITER_all_snapshots)) 2392 iter->pos.snapshot = iter->snapshot; 2393 2394 ret = bch2_btree_iter_verify_ret(iter, k); 2395 if (unlikely(ret)) { 2396 bch2_btree_iter_set_pos(iter, iter->pos); 2397 k = bkey_s_c_err(ret); 2398 } 2399 2400 bch2_btree_iter_verify_entry_exit(iter); 2401 2402 return k; 2403 end: 2404 bch2_btree_iter_set_pos(iter, end); 2405 k = bkey_s_c_null; 2406 goto out_no_locked; 2407 } 2408 2409 /** 2410 * bch2_btree_iter_next() - returns first key greater than iterator's current 2411 * position 2412 * @iter: iterator to peek from 2413 * 2414 * Returns: key if found, or an error extractable with bkey_err(). 2415 */ 2416 struct bkey_s_c bch2_btree_iter_next(struct btree_iter *iter) 2417 { 2418 if (!bch2_btree_iter_advance(iter)) 2419 return bkey_s_c_null; 2420 2421 return bch2_btree_iter_peek(iter); 2422 } 2423 2424 /** 2425 * bch2_btree_iter_peek_prev() - returns first key less than or equal to 2426 * iterator's current position 2427 * @iter: iterator to peek from 2428 * 2429 * Returns: key if found, or an error extractable with bkey_err(). 2430 */ 2431 struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *iter) 2432 { 2433 struct btree_trans *trans = iter->trans; 2434 struct bpos search_key = iter->pos; 2435 struct bkey_s_c k; 2436 struct bkey saved_k; 2437 const struct bch_val *saved_v; 2438 btree_path_idx_t saved_path = 0; 2439 int ret; 2440 2441 bch2_trans_verify_not_unlocked(trans); 2442 EBUG_ON(btree_iter_path(trans, iter)->cached || 2443 btree_iter_path(trans, iter)->level); 2444 2445 if (iter->flags & BTREE_ITER_with_journal) 2446 return bkey_s_c_err(-BCH_ERR_btree_iter_with_journal_not_supported); 2447 2448 bch2_btree_iter_verify(iter); 2449 bch2_btree_iter_verify_entry_exit(iter); 2450 2451 if (iter->flags & BTREE_ITER_filter_snapshots) 2452 search_key.snapshot = U32_MAX; 2453 2454 while (1) { 2455 iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key, 2456 iter->flags & BTREE_ITER_intent, 2457 btree_iter_ip_allocated(iter)); 2458 2459 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags); 2460 if (unlikely(ret)) { 2461 /* ensure that iter->k is consistent with iter->pos: */ 2462 bch2_btree_iter_set_pos(iter, iter->pos); 2463 k = bkey_s_c_err(ret); 2464 goto out_no_locked; 2465 } 2466 2467 struct btree_path *path = btree_iter_path(trans, iter); 2468 2469 k = btree_path_level_peek(trans, path, &path->l[0], &iter->k); 2470 if (!k.k || 2471 ((iter->flags & BTREE_ITER_is_extents) 2472 ? bpos_ge(bkey_start_pos(k.k), search_key) 2473 : bpos_gt(k.k->p, search_key))) 2474 k = btree_path_level_prev(trans, path, &path->l[0], &iter->k); 2475 2476 if (unlikely((iter->flags & BTREE_ITER_with_updates) && 2477 trans->nr_updates)) 2478 bch2_btree_trans_peek_prev_updates(trans, iter, &k); 2479 2480 if (likely(k.k)) { 2481 if (iter->flags & BTREE_ITER_filter_snapshots) { 2482 if (k.k->p.snapshot == iter->snapshot) 2483 goto got_key; 2484 2485 /* 2486 * If we have a saved candidate, and we're no 2487 * longer at the same _key_ (not pos), return 2488 * that candidate 2489 */ 2490 if (saved_path && !bkey_eq(k.k->p, saved_k.p)) { 2491 bch2_path_put_nokeep(trans, iter->path, 2492 iter->flags & BTREE_ITER_intent); 2493 iter->path = saved_path; 2494 saved_path = 0; 2495 iter->k = saved_k; 2496 k.v = saved_v; 2497 goto got_key; 2498 } 2499 2500 if (bch2_snapshot_is_ancestor(trans->c, 2501 iter->snapshot, 2502 k.k->p.snapshot)) { 2503 if (saved_path) 2504 bch2_path_put_nokeep(trans, saved_path, 2505 iter->flags & BTREE_ITER_intent); 2506 saved_path = btree_path_clone(trans, iter->path, 2507 iter->flags & BTREE_ITER_intent, 2508 _THIS_IP_); 2509 path = btree_iter_path(trans, iter); 2510 saved_k = *k.k; 2511 saved_v = k.v; 2512 } 2513 2514 search_key = bpos_predecessor(k.k->p); 2515 continue; 2516 } 2517 got_key: 2518 if (bkey_whiteout(k.k) && 2519 !(iter->flags & BTREE_ITER_all_snapshots)) { 2520 search_key = bkey_predecessor(iter, k.k->p); 2521 if (iter->flags & BTREE_ITER_filter_snapshots) 2522 search_key.snapshot = U32_MAX; 2523 continue; 2524 } 2525 2526 btree_path_set_should_be_locked(path); 2527 break; 2528 } else if (likely(!bpos_eq(path->l[0].b->data->min_key, POS_MIN))) { 2529 /* Advance to previous leaf node: */ 2530 search_key = bpos_predecessor(path->l[0].b->data->min_key); 2531 } else { 2532 /* Start of btree: */ 2533 bch2_btree_iter_set_pos(iter, POS_MIN); 2534 k = bkey_s_c_null; 2535 goto out_no_locked; 2536 } 2537 } 2538 2539 EBUG_ON(bkey_gt(bkey_start_pos(k.k), iter->pos)); 2540 2541 /* Extents can straddle iter->pos: */ 2542 if (bkey_lt(k.k->p, iter->pos)) 2543 iter->pos = k.k->p; 2544 2545 if (iter->flags & BTREE_ITER_filter_snapshots) 2546 iter->pos.snapshot = iter->snapshot; 2547 out_no_locked: 2548 if (saved_path) 2549 bch2_path_put_nokeep(trans, saved_path, iter->flags & BTREE_ITER_intent); 2550 2551 bch2_btree_iter_verify_entry_exit(iter); 2552 bch2_btree_iter_verify(iter); 2553 2554 return k; 2555 } 2556 2557 /** 2558 * bch2_btree_iter_prev() - returns first key less than iterator's current 2559 * position 2560 * @iter: iterator to peek from 2561 * 2562 * Returns: key if found, or an error extractable with bkey_err(). 2563 */ 2564 struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *iter) 2565 { 2566 if (!bch2_btree_iter_rewind(iter)) 2567 return bkey_s_c_null; 2568 2569 return bch2_btree_iter_peek_prev(iter); 2570 } 2571 2572 struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *iter) 2573 { 2574 struct btree_trans *trans = iter->trans; 2575 struct bpos search_key; 2576 struct bkey_s_c k; 2577 int ret; 2578 2579 bch2_trans_verify_not_unlocked(trans); 2580 bch2_btree_iter_verify(iter); 2581 bch2_btree_iter_verify_entry_exit(iter); 2582 EBUG_ON(btree_iter_path(trans, iter)->level && (iter->flags & BTREE_ITER_with_key_cache)); 2583 2584 /* extents can't span inode numbers: */ 2585 if ((iter->flags & BTREE_ITER_is_extents) && 2586 unlikely(iter->pos.offset == KEY_OFFSET_MAX)) { 2587 if (iter->pos.inode == KEY_INODE_MAX) 2588 return bkey_s_c_null; 2589 2590 bch2_btree_iter_set_pos(iter, bpos_nosnap_successor(iter->pos)); 2591 } 2592 2593 search_key = btree_iter_search_key(iter); 2594 iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key, 2595 iter->flags & BTREE_ITER_intent, 2596 btree_iter_ip_allocated(iter)); 2597 2598 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags); 2599 if (unlikely(ret)) { 2600 k = bkey_s_c_err(ret); 2601 goto out_no_locked; 2602 } 2603 2604 if ((iter->flags & BTREE_ITER_cached) || 2605 !(iter->flags & (BTREE_ITER_is_extents|BTREE_ITER_filter_snapshots))) { 2606 k = bkey_s_c_null; 2607 2608 if (unlikely((iter->flags & BTREE_ITER_with_updates) && 2609 trans->nr_updates)) { 2610 bch2_btree_trans_peek_slot_updates(trans, iter, &k); 2611 if (k.k) 2612 goto out; 2613 } 2614 2615 if (unlikely(iter->flags & BTREE_ITER_with_journal) && 2616 (k = btree_trans_peek_slot_journal(trans, iter)).k) 2617 goto out; 2618 2619 if (unlikely(iter->flags & BTREE_ITER_with_key_cache) && 2620 (k = btree_trans_peek_key_cache(iter, iter->pos)).k) { 2621 if (!bkey_err(k)) 2622 iter->k = *k.k; 2623 /* We're not returning a key from iter->path: */ 2624 goto out_no_locked; 2625 } 2626 2627 k = bch2_btree_path_peek_slot(trans->paths + iter->path, &iter->k); 2628 if (unlikely(!k.k)) 2629 goto out_no_locked; 2630 } else { 2631 struct bpos next; 2632 struct bpos end = iter->pos; 2633 2634 if (iter->flags & BTREE_ITER_is_extents) 2635 end.offset = U64_MAX; 2636 2637 EBUG_ON(btree_iter_path(trans, iter)->level); 2638 2639 if (iter->flags & BTREE_ITER_intent) { 2640 struct btree_iter iter2; 2641 2642 bch2_trans_copy_iter(&iter2, iter); 2643 k = bch2_btree_iter_peek_upto(&iter2, end); 2644 2645 if (k.k && !bkey_err(k)) { 2646 swap(iter->key_cache_path, iter2.key_cache_path); 2647 iter->k = iter2.k; 2648 k.k = &iter->k; 2649 } 2650 bch2_trans_iter_exit(trans, &iter2); 2651 } else { 2652 struct bpos pos = iter->pos; 2653 2654 k = bch2_btree_iter_peek_upto(iter, end); 2655 if (unlikely(bkey_err(k))) 2656 bch2_btree_iter_set_pos(iter, pos); 2657 else 2658 iter->pos = pos; 2659 } 2660 2661 if (unlikely(bkey_err(k))) 2662 goto out_no_locked; 2663 2664 next = k.k ? bkey_start_pos(k.k) : POS_MAX; 2665 2666 if (bkey_lt(iter->pos, next)) { 2667 bkey_init(&iter->k); 2668 iter->k.p = iter->pos; 2669 2670 if (iter->flags & BTREE_ITER_is_extents) { 2671 bch2_key_resize(&iter->k, 2672 min_t(u64, KEY_SIZE_MAX, 2673 (next.inode == iter->pos.inode 2674 ? next.offset 2675 : KEY_OFFSET_MAX) - 2676 iter->pos.offset)); 2677 EBUG_ON(!iter->k.size); 2678 } 2679 2680 k = (struct bkey_s_c) { &iter->k, NULL }; 2681 } 2682 } 2683 out: 2684 btree_path_set_should_be_locked(btree_iter_path(trans, iter)); 2685 out_no_locked: 2686 bch2_btree_iter_verify_entry_exit(iter); 2687 bch2_btree_iter_verify(iter); 2688 ret = bch2_btree_iter_verify_ret(iter, k); 2689 if (unlikely(ret)) 2690 return bkey_s_c_err(ret); 2691 2692 return k; 2693 } 2694 2695 struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *iter) 2696 { 2697 if (!bch2_btree_iter_advance(iter)) 2698 return bkey_s_c_null; 2699 2700 return bch2_btree_iter_peek_slot(iter); 2701 } 2702 2703 struct bkey_s_c bch2_btree_iter_prev_slot(struct btree_iter *iter) 2704 { 2705 if (!bch2_btree_iter_rewind(iter)) 2706 return bkey_s_c_null; 2707 2708 return bch2_btree_iter_peek_slot(iter); 2709 } 2710 2711 struct bkey_s_c bch2_btree_iter_peek_and_restart_outlined(struct btree_iter *iter) 2712 { 2713 struct bkey_s_c k; 2714 2715 while (btree_trans_too_many_iters(iter->trans) || 2716 (k = bch2_btree_iter_peek_type(iter, iter->flags), 2717 bch2_err_matches(bkey_err(k), BCH_ERR_transaction_restart))) 2718 bch2_trans_begin(iter->trans); 2719 2720 return k; 2721 } 2722 2723 /* new transactional stuff: */ 2724 2725 #ifdef CONFIG_BCACHEFS_DEBUG 2726 static void btree_trans_verify_sorted_refs(struct btree_trans *trans) 2727 { 2728 struct btree_path *path; 2729 unsigned i; 2730 2731 BUG_ON(trans->nr_sorted != bitmap_weight(trans->paths_allocated, trans->nr_paths) - 1); 2732 2733 trans_for_each_path(trans, path, i) { 2734 BUG_ON(path->sorted_idx >= trans->nr_sorted); 2735 BUG_ON(trans->sorted[path->sorted_idx] != i); 2736 } 2737 2738 for (i = 0; i < trans->nr_sorted; i++) { 2739 unsigned idx = trans->sorted[i]; 2740 2741 BUG_ON(!test_bit(idx, trans->paths_allocated)); 2742 BUG_ON(trans->paths[idx].sorted_idx != i); 2743 } 2744 } 2745 2746 static void btree_trans_verify_sorted(struct btree_trans *trans) 2747 { 2748 struct btree_path *path, *prev = NULL; 2749 struct trans_for_each_path_inorder_iter iter; 2750 2751 if (!bch2_debug_check_iterators) 2752 return; 2753 2754 trans_for_each_path_inorder(trans, path, iter) { 2755 if (prev && btree_path_cmp(prev, path) > 0) { 2756 __bch2_dump_trans_paths_updates(trans, true); 2757 panic("trans paths out of order!\n"); 2758 } 2759 prev = path; 2760 } 2761 } 2762 #else 2763 static inline void btree_trans_verify_sorted_refs(struct btree_trans *trans) {} 2764 static inline void btree_trans_verify_sorted(struct btree_trans *trans) {} 2765 #endif 2766 2767 void __bch2_btree_trans_sort_paths(struct btree_trans *trans) 2768 { 2769 int i, l = 0, r = trans->nr_sorted, inc = 1; 2770 bool swapped; 2771 2772 btree_trans_verify_sorted_refs(trans); 2773 2774 if (trans->paths_sorted) 2775 goto out; 2776 2777 /* 2778 * Cocktail shaker sort: this is efficient because iterators will be 2779 * mostly sorted. 2780 */ 2781 do { 2782 swapped = false; 2783 2784 for (i = inc > 0 ? l : r - 2; 2785 i + 1 < r && i >= l; 2786 i += inc) { 2787 if (btree_path_cmp(trans->paths + trans->sorted[i], 2788 trans->paths + trans->sorted[i + 1]) > 0) { 2789 swap(trans->sorted[i], trans->sorted[i + 1]); 2790 trans->paths[trans->sorted[i]].sorted_idx = i; 2791 trans->paths[trans->sorted[i + 1]].sorted_idx = i + 1; 2792 swapped = true; 2793 } 2794 } 2795 2796 if (inc > 0) 2797 --r; 2798 else 2799 l++; 2800 inc = -inc; 2801 } while (swapped); 2802 2803 trans->paths_sorted = true; 2804 out: 2805 btree_trans_verify_sorted(trans); 2806 } 2807 2808 static inline void btree_path_list_remove(struct btree_trans *trans, 2809 struct btree_path *path) 2810 { 2811 EBUG_ON(path->sorted_idx >= trans->nr_sorted); 2812 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 2813 trans->nr_sorted--; 2814 memmove_u64s_down_small(trans->sorted + path->sorted_idx, 2815 trans->sorted + path->sorted_idx + 1, 2816 DIV_ROUND_UP(trans->nr_sorted - path->sorted_idx, 2817 sizeof(u64) / sizeof(btree_path_idx_t))); 2818 #else 2819 array_remove_item(trans->sorted, trans->nr_sorted, path->sorted_idx); 2820 #endif 2821 for (unsigned i = path->sorted_idx; i < trans->nr_sorted; i++) 2822 trans->paths[trans->sorted[i]].sorted_idx = i; 2823 } 2824 2825 static inline void btree_path_list_add(struct btree_trans *trans, 2826 btree_path_idx_t pos, 2827 btree_path_idx_t path_idx) 2828 { 2829 struct btree_path *path = trans->paths + path_idx; 2830 2831 path->sorted_idx = pos ? trans->paths[pos].sorted_idx + 1 : trans->nr_sorted; 2832 2833 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 2834 memmove_u64s_up_small(trans->sorted + path->sorted_idx + 1, 2835 trans->sorted + path->sorted_idx, 2836 DIV_ROUND_UP(trans->nr_sorted - path->sorted_idx, 2837 sizeof(u64) / sizeof(btree_path_idx_t))); 2838 trans->nr_sorted++; 2839 trans->sorted[path->sorted_idx] = path_idx; 2840 #else 2841 array_insert_item(trans->sorted, trans->nr_sorted, path->sorted_idx, path_idx); 2842 #endif 2843 2844 for (unsigned i = path->sorted_idx; i < trans->nr_sorted; i++) 2845 trans->paths[trans->sorted[i]].sorted_idx = i; 2846 2847 btree_trans_verify_sorted_refs(trans); 2848 } 2849 2850 void bch2_trans_iter_exit(struct btree_trans *trans, struct btree_iter *iter) 2851 { 2852 if (iter->update_path) 2853 bch2_path_put_nokeep(trans, iter->update_path, 2854 iter->flags & BTREE_ITER_intent); 2855 if (iter->path) 2856 bch2_path_put(trans, iter->path, 2857 iter->flags & BTREE_ITER_intent); 2858 if (iter->key_cache_path) 2859 bch2_path_put(trans, iter->key_cache_path, 2860 iter->flags & BTREE_ITER_intent); 2861 iter->path = 0; 2862 iter->update_path = 0; 2863 iter->key_cache_path = 0; 2864 iter->trans = NULL; 2865 } 2866 2867 void bch2_trans_iter_init_outlined(struct btree_trans *trans, 2868 struct btree_iter *iter, 2869 enum btree_id btree_id, struct bpos pos, 2870 unsigned flags) 2871 { 2872 bch2_trans_iter_init_common(trans, iter, btree_id, pos, 0, 0, 2873 bch2_btree_iter_flags(trans, btree_id, flags), 2874 _RET_IP_); 2875 } 2876 2877 void bch2_trans_node_iter_init(struct btree_trans *trans, 2878 struct btree_iter *iter, 2879 enum btree_id btree_id, 2880 struct bpos pos, 2881 unsigned locks_want, 2882 unsigned depth, 2883 unsigned flags) 2884 { 2885 flags |= BTREE_ITER_not_extents; 2886 flags |= BTREE_ITER_snapshot_field; 2887 flags |= BTREE_ITER_all_snapshots; 2888 2889 bch2_trans_iter_init_common(trans, iter, btree_id, pos, locks_want, depth, 2890 __bch2_btree_iter_flags(trans, btree_id, flags), 2891 _RET_IP_); 2892 2893 iter->min_depth = depth; 2894 2895 struct btree_path *path = btree_iter_path(trans, iter); 2896 BUG_ON(path->locks_want < min(locks_want, BTREE_MAX_DEPTH)); 2897 BUG_ON(path->level != depth); 2898 BUG_ON(iter->min_depth != depth); 2899 } 2900 2901 void bch2_trans_copy_iter(struct btree_iter *dst, struct btree_iter *src) 2902 { 2903 struct btree_trans *trans = src->trans; 2904 2905 *dst = *src; 2906 #ifdef TRACK_PATH_ALLOCATED 2907 dst->ip_allocated = _RET_IP_; 2908 #endif 2909 if (src->path) 2910 __btree_path_get(trans->paths + src->path, src->flags & BTREE_ITER_intent); 2911 if (src->update_path) 2912 __btree_path_get(trans->paths + src->update_path, src->flags & BTREE_ITER_intent); 2913 dst->key_cache_path = 0; 2914 } 2915 2916 void *__bch2_trans_kmalloc(struct btree_trans *trans, size_t size) 2917 { 2918 struct bch_fs *c = trans->c; 2919 unsigned new_top = trans->mem_top + size; 2920 unsigned old_bytes = trans->mem_bytes; 2921 unsigned new_bytes = roundup_pow_of_two(new_top); 2922 int ret; 2923 void *new_mem; 2924 void *p; 2925 2926 WARN_ON_ONCE(new_bytes > BTREE_TRANS_MEM_MAX); 2927 2928 struct btree_transaction_stats *s = btree_trans_stats(trans); 2929 s->max_mem = max(s->max_mem, new_bytes); 2930 2931 if (trans->used_mempool) { 2932 if (trans->mem_bytes >= new_bytes) 2933 goto out_change_top; 2934 2935 /* No more space from mempool item, need malloc new one */ 2936 new_mem = kmalloc(new_bytes, GFP_NOWAIT|__GFP_NOWARN); 2937 if (unlikely(!new_mem)) { 2938 bch2_trans_unlock(trans); 2939 2940 new_mem = kmalloc(new_bytes, GFP_KERNEL); 2941 if (!new_mem) 2942 return ERR_PTR(-BCH_ERR_ENOMEM_trans_kmalloc); 2943 2944 ret = bch2_trans_relock(trans); 2945 if (ret) { 2946 kfree(new_mem); 2947 return ERR_PTR(ret); 2948 } 2949 } 2950 memcpy(new_mem, trans->mem, trans->mem_top); 2951 trans->used_mempool = false; 2952 mempool_free(trans->mem, &c->btree_trans_mem_pool); 2953 goto out_new_mem; 2954 } 2955 2956 new_mem = krealloc(trans->mem, new_bytes, GFP_NOWAIT|__GFP_NOWARN); 2957 if (unlikely(!new_mem)) { 2958 bch2_trans_unlock(trans); 2959 2960 new_mem = krealloc(trans->mem, new_bytes, GFP_KERNEL); 2961 if (!new_mem && new_bytes <= BTREE_TRANS_MEM_MAX) { 2962 new_mem = mempool_alloc(&c->btree_trans_mem_pool, GFP_KERNEL); 2963 new_bytes = BTREE_TRANS_MEM_MAX; 2964 memcpy(new_mem, trans->mem, trans->mem_top); 2965 trans->used_mempool = true; 2966 kfree(trans->mem); 2967 } 2968 2969 if (!new_mem) 2970 return ERR_PTR(-BCH_ERR_ENOMEM_trans_kmalloc); 2971 2972 trans->mem = new_mem; 2973 trans->mem_bytes = new_bytes; 2974 2975 ret = bch2_trans_relock(trans); 2976 if (ret) 2977 return ERR_PTR(ret); 2978 } 2979 out_new_mem: 2980 trans->mem = new_mem; 2981 trans->mem_bytes = new_bytes; 2982 2983 if (old_bytes) { 2984 trace_and_count(c, trans_restart_mem_realloced, trans, _RET_IP_, new_bytes); 2985 return ERR_PTR(btree_trans_restart(trans, BCH_ERR_transaction_restart_mem_realloced)); 2986 } 2987 out_change_top: 2988 p = trans->mem + trans->mem_top; 2989 trans->mem_top += size; 2990 memset(p, 0, size); 2991 return p; 2992 } 2993 2994 static inline void check_srcu_held_too_long(struct btree_trans *trans) 2995 { 2996 WARN(trans->srcu_held && time_after(jiffies, trans->srcu_lock_time + HZ * 10), 2997 "btree trans held srcu lock (delaying memory reclaim) for %lu seconds", 2998 (jiffies - trans->srcu_lock_time) / HZ); 2999 } 3000 3001 void bch2_trans_srcu_unlock(struct btree_trans *trans) 3002 { 3003 if (trans->srcu_held) { 3004 struct bch_fs *c = trans->c; 3005 struct btree_path *path; 3006 unsigned i; 3007 3008 trans_for_each_path(trans, path, i) 3009 if (path->cached && !btree_node_locked(path, 0)) 3010 path->l[0].b = ERR_PTR(-BCH_ERR_no_btree_node_srcu_reset); 3011 3012 check_srcu_held_too_long(trans); 3013 srcu_read_unlock(&c->btree_trans_barrier, trans->srcu_idx); 3014 trans->srcu_held = false; 3015 } 3016 } 3017 3018 static void bch2_trans_srcu_lock(struct btree_trans *trans) 3019 { 3020 if (!trans->srcu_held) { 3021 trans->srcu_idx = srcu_read_lock(&trans->c->btree_trans_barrier); 3022 trans->srcu_lock_time = jiffies; 3023 trans->srcu_held = true; 3024 } 3025 } 3026 3027 /** 3028 * bch2_trans_begin() - reset a transaction after a interrupted attempt 3029 * @trans: transaction to reset 3030 * 3031 * Returns: current restart counter, to be used with trans_was_restarted() 3032 * 3033 * While iterating over nodes or updating nodes a attempt to lock a btree node 3034 * may return BCH_ERR_transaction_restart when the trylock fails. When this 3035 * occurs bch2_trans_begin() should be called and the transaction retried. 3036 */ 3037 u32 bch2_trans_begin(struct btree_trans *trans) 3038 { 3039 struct btree_path *path; 3040 unsigned i; 3041 u64 now; 3042 3043 bch2_trans_reset_updates(trans); 3044 3045 trans->restart_count++; 3046 trans->mem_top = 0; 3047 trans->journal_entries = NULL; 3048 3049 trans_for_each_path(trans, path, i) { 3050 path->should_be_locked = false; 3051 3052 /* 3053 * If the transaction wasn't restarted, we're presuming to be 3054 * doing something new: dont keep iterators excpt the ones that 3055 * are in use - except for the subvolumes btree: 3056 */ 3057 if (!trans->restarted && path->btree_id != BTREE_ID_subvolumes) 3058 path->preserve = false; 3059 3060 /* 3061 * XXX: we probably shouldn't be doing this if the transaction 3062 * was restarted, but currently we still overflow transaction 3063 * iterators if we do that 3064 */ 3065 if (!path->ref && !path->preserve) 3066 __bch2_path_free(trans, i); 3067 else 3068 path->preserve = false; 3069 } 3070 3071 now = local_clock(); 3072 3073 if (!IS_ENABLED(CONFIG_BCACHEFS_NO_LATENCY_ACCT) && 3074 time_after64(now, trans->last_begin_time + 10)) 3075 __bch2_time_stats_update(&btree_trans_stats(trans)->duration, 3076 trans->last_begin_time, now); 3077 3078 if (!trans->restarted && 3079 (need_resched() || 3080 time_after64(now, trans->last_begin_time + BTREE_TRANS_MAX_LOCK_HOLD_TIME_NS))) { 3081 bch2_trans_unlock(trans); 3082 cond_resched(); 3083 now = local_clock(); 3084 } 3085 trans->last_begin_time = now; 3086 3087 if (unlikely(trans->srcu_held && 3088 time_after(jiffies, trans->srcu_lock_time + msecs_to_jiffies(10)))) 3089 bch2_trans_srcu_unlock(trans); 3090 3091 trans->last_begin_ip = _RET_IP_; 3092 trans->locked = true; 3093 3094 if (trans->restarted) { 3095 bch2_btree_path_traverse_all(trans); 3096 trans->notrace_relock_fail = false; 3097 } 3098 3099 bch2_trans_verify_not_unlocked(trans); 3100 return trans->restart_count; 3101 } 3102 3103 const char *bch2_btree_transaction_fns[BCH_TRANSACTIONS_NR] = { "(unknown)" }; 3104 3105 unsigned bch2_trans_get_fn_idx(const char *fn) 3106 { 3107 for (unsigned i = 0; i < ARRAY_SIZE(bch2_btree_transaction_fns); i++) 3108 if (!bch2_btree_transaction_fns[i] || 3109 bch2_btree_transaction_fns[i] == fn) { 3110 bch2_btree_transaction_fns[i] = fn; 3111 return i; 3112 } 3113 3114 pr_warn_once("BCH_TRANSACTIONS_NR not big enough!"); 3115 return 0; 3116 } 3117 3118 struct btree_trans *__bch2_trans_get(struct bch_fs *c, unsigned fn_idx) 3119 __acquires(&c->btree_trans_barrier) 3120 { 3121 struct btree_trans *trans; 3122 3123 if (IS_ENABLED(__KERNEL__)) { 3124 trans = this_cpu_xchg(c->btree_trans_bufs->trans, NULL); 3125 if (trans) { 3126 memset(trans, 0, offsetof(struct btree_trans, list)); 3127 goto got_trans; 3128 } 3129 } 3130 3131 trans = mempool_alloc(&c->btree_trans_pool, GFP_NOFS); 3132 memset(trans, 0, sizeof(*trans)); 3133 3134 seqmutex_lock(&c->btree_trans_lock); 3135 if (IS_ENABLED(CONFIG_BCACHEFS_DEBUG)) { 3136 struct btree_trans *pos; 3137 pid_t pid = current->pid; 3138 3139 trans->locking_wait.task = current; 3140 3141 list_for_each_entry(pos, &c->btree_trans_list, list) { 3142 struct task_struct *pos_task = READ_ONCE(pos->locking_wait.task); 3143 /* 3144 * We'd much prefer to be stricter here and completely 3145 * disallow multiple btree_trans in the same thread - 3146 * but the data move path calls bch2_write when we 3147 * already have a btree_trans initialized. 3148 */ 3149 BUG_ON(pos_task && 3150 pid == pos_task->pid && 3151 pos->locked); 3152 } 3153 } 3154 3155 list_add(&trans->list, &c->btree_trans_list); 3156 seqmutex_unlock(&c->btree_trans_lock); 3157 got_trans: 3158 trans->c = c; 3159 trans->last_begin_time = local_clock(); 3160 trans->fn_idx = fn_idx; 3161 trans->locking_wait.task = current; 3162 trans->locked = true; 3163 trans->journal_replay_not_finished = 3164 unlikely(!test_bit(JOURNAL_replay_done, &c->journal.flags)) && 3165 atomic_inc_not_zero(&c->journal_keys.ref); 3166 trans->nr_paths = ARRAY_SIZE(trans->_paths); 3167 trans->paths_allocated = trans->_paths_allocated; 3168 trans->sorted = trans->_sorted; 3169 trans->paths = trans->_paths; 3170 trans->updates = trans->_updates; 3171 3172 *trans_paths_nr(trans->paths) = BTREE_ITER_INITIAL; 3173 3174 trans->paths_allocated[0] = 1; 3175 3176 if (fn_idx < BCH_TRANSACTIONS_NR) { 3177 trans->fn = bch2_btree_transaction_fns[fn_idx]; 3178 3179 struct btree_transaction_stats *s = &c->btree_transaction_stats[fn_idx]; 3180 3181 if (s->max_mem) { 3182 unsigned expected_mem_bytes = roundup_pow_of_two(s->max_mem); 3183 3184 trans->mem = kmalloc(expected_mem_bytes, GFP_KERNEL); 3185 if (likely(trans->mem)) 3186 trans->mem_bytes = expected_mem_bytes; 3187 } 3188 3189 trans->nr_paths_max = s->nr_max_paths; 3190 trans->journal_entries_size = s->journal_entries_size; 3191 } 3192 3193 trans->srcu_idx = srcu_read_lock(&c->btree_trans_barrier); 3194 trans->srcu_lock_time = jiffies; 3195 trans->srcu_held = true; 3196 3197 closure_init_stack_release(&trans->ref); 3198 return trans; 3199 } 3200 3201 static void check_btree_paths_leaked(struct btree_trans *trans) 3202 { 3203 #ifdef CONFIG_BCACHEFS_DEBUG 3204 struct bch_fs *c = trans->c; 3205 struct btree_path *path; 3206 unsigned i; 3207 3208 trans_for_each_path(trans, path, i) 3209 if (path->ref) 3210 goto leaked; 3211 return; 3212 leaked: 3213 bch_err(c, "btree paths leaked from %s!", trans->fn); 3214 trans_for_each_path(trans, path, i) 3215 if (path->ref) 3216 printk(KERN_ERR " btree %s %pS\n", 3217 bch2_btree_id_str(path->btree_id), 3218 (void *) path->ip_allocated); 3219 /* Be noisy about this: */ 3220 bch2_fatal_error(c); 3221 #endif 3222 } 3223 3224 void bch2_trans_put(struct btree_trans *trans) 3225 __releases(&c->btree_trans_barrier) 3226 { 3227 struct bch_fs *c = trans->c; 3228 3229 bch2_trans_unlock(trans); 3230 3231 trans_for_each_update(trans, i) 3232 __btree_path_put(trans->paths + i->path, true); 3233 trans->nr_updates = 0; 3234 3235 check_btree_paths_leaked(trans); 3236 3237 if (trans->srcu_held) { 3238 check_srcu_held_too_long(trans); 3239 srcu_read_unlock(&c->btree_trans_barrier, trans->srcu_idx); 3240 } 3241 3242 if (trans->fs_usage_deltas) { 3243 if (trans->fs_usage_deltas->size + sizeof(trans->fs_usage_deltas) == 3244 REPLICAS_DELTA_LIST_MAX) 3245 mempool_free(trans->fs_usage_deltas, 3246 &c->replicas_delta_pool); 3247 else 3248 kfree(trans->fs_usage_deltas); 3249 } 3250 3251 if (unlikely(trans->journal_replay_not_finished)) 3252 bch2_journal_keys_put(c); 3253 3254 /* 3255 * trans->ref protects trans->locking_wait.task, btree_paths array; used 3256 * by cycle detector 3257 */ 3258 closure_return_sync(&trans->ref); 3259 trans->locking_wait.task = NULL; 3260 3261 unsigned long *paths_allocated = trans->paths_allocated; 3262 trans->paths_allocated = NULL; 3263 trans->paths = NULL; 3264 3265 if (paths_allocated != trans->_paths_allocated) 3266 kvfree_rcu_mightsleep(paths_allocated); 3267 3268 if (trans->used_mempool) 3269 mempool_free(trans->mem, &c->btree_trans_mem_pool); 3270 else 3271 kfree(trans->mem); 3272 3273 /* Userspace doesn't have a real percpu implementation: */ 3274 if (IS_ENABLED(__KERNEL__)) 3275 trans = this_cpu_xchg(c->btree_trans_bufs->trans, trans); 3276 3277 if (trans) { 3278 seqmutex_lock(&c->btree_trans_lock); 3279 list_del(&trans->list); 3280 seqmutex_unlock(&c->btree_trans_lock); 3281 3282 mempool_free(trans, &c->btree_trans_pool); 3283 } 3284 } 3285 3286 static void __maybe_unused 3287 bch2_btree_bkey_cached_common_to_text(struct printbuf *out, 3288 struct btree_bkey_cached_common *b) 3289 { 3290 struct six_lock_count c = six_lock_counts(&b->lock); 3291 struct task_struct *owner; 3292 pid_t pid; 3293 3294 rcu_read_lock(); 3295 owner = READ_ONCE(b->lock.owner); 3296 pid = owner ? owner->pid : 0; 3297 rcu_read_unlock(); 3298 3299 prt_printf(out, "\t%px %c l=%u %s:", b, b->cached ? 'c' : 'b', 3300 b->level, bch2_btree_id_str(b->btree_id)); 3301 bch2_bpos_to_text(out, btree_node_pos(b)); 3302 3303 prt_printf(out, "\t locks %u:%u:%u held by pid %u", 3304 c.n[0], c.n[1], c.n[2], pid); 3305 } 3306 3307 void bch2_btree_trans_to_text(struct printbuf *out, struct btree_trans *trans) 3308 { 3309 struct btree_bkey_cached_common *b; 3310 static char lock_types[] = { 'r', 'i', 'w' }; 3311 struct task_struct *task = READ_ONCE(trans->locking_wait.task); 3312 unsigned l, idx; 3313 3314 /* before rcu_read_lock(): */ 3315 bch2_printbuf_make_room(out, 4096); 3316 3317 if (!out->nr_tabstops) { 3318 printbuf_tabstop_push(out, 16); 3319 printbuf_tabstop_push(out, 32); 3320 } 3321 3322 prt_printf(out, "%i %s\n", task ? task->pid : 0, trans->fn); 3323 3324 /* trans->paths is rcu protected vs. freeing */ 3325 rcu_read_lock(); 3326 out->atomic++; 3327 3328 struct btree_path *paths = rcu_dereference(trans->paths); 3329 if (!paths) 3330 goto out; 3331 3332 unsigned long *paths_allocated = trans_paths_allocated(paths); 3333 3334 trans_for_each_path_idx_from(paths_allocated, *trans_paths_nr(paths), idx, 1) { 3335 struct btree_path *path = paths + idx; 3336 if (!path->nodes_locked) 3337 continue; 3338 3339 prt_printf(out, " path %u %c l=%u %s:", 3340 idx, 3341 path->cached ? 'c' : 'b', 3342 path->level, 3343 bch2_btree_id_str(path->btree_id)); 3344 bch2_bpos_to_text(out, path->pos); 3345 prt_newline(out); 3346 3347 for (l = 0; l < BTREE_MAX_DEPTH; l++) { 3348 if (btree_node_locked(path, l) && 3349 !IS_ERR_OR_NULL(b = (void *) READ_ONCE(path->l[l].b))) { 3350 prt_printf(out, " %c l=%u ", 3351 lock_types[btree_node_locked_type(path, l)], l); 3352 bch2_btree_bkey_cached_common_to_text(out, b); 3353 prt_newline(out); 3354 } 3355 } 3356 } 3357 3358 b = READ_ONCE(trans->locking); 3359 if (b) { 3360 prt_printf(out, " blocked for %lluus on\n", 3361 div_u64(local_clock() - trans->locking_wait.start_time, 1000)); 3362 prt_printf(out, " %c", lock_types[trans->locking_wait.lock_want]); 3363 bch2_btree_bkey_cached_common_to_text(out, b); 3364 prt_newline(out); 3365 } 3366 out: 3367 --out->atomic; 3368 rcu_read_unlock(); 3369 } 3370 3371 void bch2_fs_btree_iter_exit(struct bch_fs *c) 3372 { 3373 struct btree_transaction_stats *s; 3374 struct btree_trans *trans; 3375 int cpu; 3376 3377 if (c->btree_trans_bufs) 3378 for_each_possible_cpu(cpu) { 3379 struct btree_trans *trans = 3380 per_cpu_ptr(c->btree_trans_bufs, cpu)->trans; 3381 3382 if (trans) { 3383 seqmutex_lock(&c->btree_trans_lock); 3384 list_del(&trans->list); 3385 seqmutex_unlock(&c->btree_trans_lock); 3386 } 3387 kfree(trans); 3388 } 3389 free_percpu(c->btree_trans_bufs); 3390 3391 trans = list_first_entry_or_null(&c->btree_trans_list, struct btree_trans, list); 3392 if (trans) 3393 panic("%s leaked btree_trans\n", trans->fn); 3394 3395 for (s = c->btree_transaction_stats; 3396 s < c->btree_transaction_stats + ARRAY_SIZE(c->btree_transaction_stats); 3397 s++) { 3398 kfree(s->max_paths_text); 3399 bch2_time_stats_exit(&s->lock_hold_times); 3400 } 3401 3402 if (c->btree_trans_barrier_initialized) { 3403 synchronize_srcu_expedited(&c->btree_trans_barrier); 3404 cleanup_srcu_struct(&c->btree_trans_barrier); 3405 } 3406 mempool_exit(&c->btree_trans_mem_pool); 3407 mempool_exit(&c->btree_trans_pool); 3408 } 3409 3410 void bch2_fs_btree_iter_init_early(struct bch_fs *c) 3411 { 3412 struct btree_transaction_stats *s; 3413 3414 for (s = c->btree_transaction_stats; 3415 s < c->btree_transaction_stats + ARRAY_SIZE(c->btree_transaction_stats); 3416 s++) { 3417 bch2_time_stats_init(&s->duration); 3418 bch2_time_stats_init(&s->lock_hold_times); 3419 mutex_init(&s->lock); 3420 } 3421 3422 INIT_LIST_HEAD(&c->btree_trans_list); 3423 seqmutex_init(&c->btree_trans_lock); 3424 } 3425 3426 int bch2_fs_btree_iter_init(struct bch_fs *c) 3427 { 3428 int ret; 3429 3430 c->btree_trans_bufs = alloc_percpu(struct btree_trans_buf); 3431 if (!c->btree_trans_bufs) 3432 return -ENOMEM; 3433 3434 ret = mempool_init_kmalloc_pool(&c->btree_trans_pool, 1, 3435 sizeof(struct btree_trans)) ?: 3436 mempool_init_kmalloc_pool(&c->btree_trans_mem_pool, 1, 3437 BTREE_TRANS_MEM_MAX) ?: 3438 init_srcu_struct(&c->btree_trans_barrier); 3439 if (!ret) 3440 c->btree_trans_barrier_initialized = true; 3441 return ret; 3442 } 3443