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