1 // SPDX-License-Identifier: GPL-2.0 2 3 #include "bcachefs.h" 4 #include "bkey_methods.h" 5 #include "bkey_buf.h" 6 #include "btree_cache.h" 7 #include "btree_iter.h" 8 #include "btree_journal_iter.h" 9 #include "btree_key_cache.h" 10 #include "btree_locking.h" 11 #include "btree_update.h" 12 #include "debug.h" 13 #include "error.h" 14 #include "extents.h" 15 #include "journal.h" 16 #include "journal_io.h" 17 #include "replicas.h" 18 #include "snapshot.h" 19 #include "trace.h" 20 21 #include <linux/random.h> 22 #include <linux/prefetch.h> 23 24 static inline void btree_path_list_remove(struct btree_trans *, struct btree_path *); 25 static inline void btree_path_list_add(struct btree_trans *, 26 btree_path_idx_t, btree_path_idx_t); 27 28 static inline unsigned long btree_iter_ip_allocated(struct btree_iter *iter) 29 { 30 #ifdef TRACK_PATH_ALLOCATED 31 return iter->ip_allocated; 32 #else 33 return 0; 34 #endif 35 } 36 37 static btree_path_idx_t btree_path_alloc(struct btree_trans *, btree_path_idx_t); 38 static void bch2_trans_srcu_lock(struct btree_trans *); 39 40 static inline int __btree_path_cmp(const struct btree_path *l, 41 enum btree_id r_btree_id, 42 bool r_cached, 43 struct bpos r_pos, 44 unsigned r_level) 45 { 46 /* 47 * Must match lock ordering as defined by __bch2_btree_node_lock: 48 */ 49 return cmp_int(l->btree_id, r_btree_id) ?: 50 cmp_int((int) l->cached, (int) r_cached) ?: 51 bpos_cmp(l->pos, r_pos) ?: 52 -cmp_int(l->level, r_level); 53 } 54 55 static inline int btree_path_cmp(const struct btree_path *l, 56 const struct btree_path *r) 57 { 58 return __btree_path_cmp(l, r->btree_id, r->cached, r->pos, r->level); 59 } 60 61 static inline struct bpos bkey_successor(struct btree_iter *iter, struct bpos p) 62 { 63 /* Are we iterating over keys in all snapshots? */ 64 if (iter->flags & BTREE_ITER_all_snapshots) { 65 p = bpos_successor(p); 66 } else { 67 p = bpos_nosnap_successor(p); 68 p.snapshot = iter->snapshot; 69 } 70 71 return p; 72 } 73 74 static inline struct bpos bkey_predecessor(struct btree_iter *iter, struct bpos p) 75 { 76 /* Are we iterating over keys in all snapshots? */ 77 if (iter->flags & BTREE_ITER_all_snapshots) { 78 p = bpos_predecessor(p); 79 } else { 80 p = bpos_nosnap_predecessor(p); 81 p.snapshot = iter->snapshot; 82 } 83 84 return p; 85 } 86 87 static inline struct bpos btree_iter_search_key(struct btree_iter *iter) 88 { 89 struct bpos pos = iter->pos; 90 91 if ((iter->flags & BTREE_ITER_is_extents) && 92 !bkey_eq(pos, POS_MAX)) 93 pos = bkey_successor(iter, pos); 94 return pos; 95 } 96 97 static inline bool btree_path_pos_before_node(struct btree_path *path, 98 struct btree *b) 99 { 100 return bpos_lt(path->pos, b->data->min_key); 101 } 102 103 static inline bool btree_path_pos_after_node(struct btree_path *path, 104 struct btree *b) 105 { 106 return bpos_gt(path->pos, b->key.k.p); 107 } 108 109 static inline bool btree_path_pos_in_node(struct btree_path *path, 110 struct btree *b) 111 { 112 return path->btree_id == b->c.btree_id && 113 !btree_path_pos_before_node(path, b) && 114 !btree_path_pos_after_node(path, b); 115 } 116 117 /* Btree iterator: */ 118 119 #ifdef CONFIG_BCACHEFS_DEBUG 120 121 static void bch2_btree_path_verify_cached(struct btree_trans *trans, 122 struct btree_path *path) 123 { 124 struct bkey_cached *ck; 125 bool locked = btree_node_locked(path, 0); 126 127 if (!bch2_btree_node_relock(trans, path, 0)) 128 return; 129 130 ck = (void *) path->l[0].b; 131 BUG_ON(ck->key.btree_id != path->btree_id || 132 !bkey_eq(ck->key.pos, path->pos)); 133 134 if (!locked) 135 btree_node_unlock(trans, path, 0); 136 } 137 138 static void bch2_btree_path_verify_level(struct btree_trans *trans, 139 struct btree_path *path, unsigned level) 140 { 141 struct btree_path_level *l; 142 struct btree_node_iter tmp; 143 bool locked; 144 struct bkey_packed *p, *k; 145 struct printbuf buf1 = PRINTBUF; 146 struct printbuf buf2 = PRINTBUF; 147 struct printbuf buf3 = PRINTBUF; 148 const char *msg; 149 150 if (!bch2_debug_check_iterators) 151 return; 152 153 l = &path->l[level]; 154 tmp = l->iter; 155 locked = btree_node_locked(path, level); 156 157 if (path->cached) { 158 if (!level) 159 bch2_btree_path_verify_cached(trans, path); 160 return; 161 } 162 163 if (!btree_path_node(path, level)) 164 return; 165 166 if (!bch2_btree_node_relock_notrace(trans, path, level)) 167 return; 168 169 BUG_ON(!btree_path_pos_in_node(path, l->b)); 170 171 bch2_btree_node_iter_verify(&l->iter, l->b); 172 173 /* 174 * For interior nodes, the iterator will have skipped past deleted keys: 175 */ 176 p = level 177 ? bch2_btree_node_iter_prev(&tmp, l->b) 178 : bch2_btree_node_iter_prev_all(&tmp, l->b); 179 k = bch2_btree_node_iter_peek_all(&l->iter, l->b); 180 181 if (p && bkey_iter_pos_cmp(l->b, p, &path->pos) >= 0) { 182 msg = "before"; 183 goto err; 184 } 185 186 if (k && bkey_iter_pos_cmp(l->b, k, &path->pos) < 0) { 187 msg = "after"; 188 goto err; 189 } 190 191 if (!locked) 192 btree_node_unlock(trans, path, level); 193 return; 194 err: 195 bch2_bpos_to_text(&buf1, path->pos); 196 197 if (p) { 198 struct bkey uk = bkey_unpack_key(l->b, p); 199 200 bch2_bkey_to_text(&buf2, &uk); 201 } else { 202 prt_printf(&buf2, "(none)"); 203 } 204 205 if (k) { 206 struct bkey uk = bkey_unpack_key(l->b, k); 207 208 bch2_bkey_to_text(&buf3, &uk); 209 } else { 210 prt_printf(&buf3, "(none)"); 211 } 212 213 panic("path should be %s key at level %u:\n" 214 "path pos %s\n" 215 "prev key %s\n" 216 "cur key %s\n", 217 msg, level, buf1.buf, buf2.buf, buf3.buf); 218 } 219 220 static void bch2_btree_path_verify(struct btree_trans *trans, 221 struct btree_path *path) 222 { 223 struct bch_fs *c = trans->c; 224 225 for (unsigned i = 0; i < (!path->cached ? BTREE_MAX_DEPTH : 1); i++) { 226 if (!path->l[i].b) { 227 BUG_ON(!path->cached && 228 bch2_btree_id_root(c, path->btree_id)->b->c.level > i); 229 break; 230 } 231 232 bch2_btree_path_verify_level(trans, path, i); 233 } 234 235 bch2_btree_path_verify_locks(path); 236 } 237 238 void bch2_trans_verify_paths(struct btree_trans *trans) 239 { 240 struct btree_path *path; 241 unsigned iter; 242 243 trans_for_each_path(trans, path, iter) 244 bch2_btree_path_verify(trans, path); 245 } 246 247 static void bch2_btree_iter_verify(struct btree_iter *iter) 248 { 249 struct btree_trans *trans = iter->trans; 250 251 BUG_ON(!!(iter->flags & BTREE_ITER_cached) != btree_iter_path(trans, iter)->cached); 252 253 BUG_ON((iter->flags & BTREE_ITER_is_extents) && 254 (iter->flags & BTREE_ITER_all_snapshots)); 255 256 BUG_ON(!(iter->flags & BTREE_ITER_snapshot_field) && 257 (iter->flags & BTREE_ITER_all_snapshots) && 258 !btree_type_has_snapshot_field(iter->btree_id)); 259 260 if (iter->update_path) 261 bch2_btree_path_verify(trans, &trans->paths[iter->update_path]); 262 bch2_btree_path_verify(trans, btree_iter_path(trans, iter)); 263 } 264 265 static void bch2_btree_iter_verify_entry_exit(struct btree_iter *iter) 266 { 267 BUG_ON((iter->flags & BTREE_ITER_filter_snapshots) && 268 !iter->pos.snapshot); 269 270 BUG_ON(!(iter->flags & BTREE_ITER_all_snapshots) && 271 iter->pos.snapshot != iter->snapshot); 272 273 BUG_ON(bkey_lt(iter->pos, bkey_start_pos(&iter->k)) || 274 bkey_gt(iter->pos, iter->k.p)); 275 } 276 277 static int bch2_btree_iter_verify_ret(struct btree_iter *iter, struct bkey_s_c k) 278 { 279 struct btree_trans *trans = iter->trans; 280 struct btree_iter copy; 281 struct bkey_s_c prev; 282 int ret = 0; 283 284 if (!bch2_debug_check_iterators) 285 return 0; 286 287 if (!(iter->flags & BTREE_ITER_filter_snapshots)) 288 return 0; 289 290 if (bkey_err(k) || !k.k) 291 return 0; 292 293 BUG_ON(!bch2_snapshot_is_ancestor(trans->c, 294 iter->snapshot, 295 k.k->p.snapshot)); 296 297 bch2_trans_iter_init(trans, ©, iter->btree_id, iter->pos, 298 BTREE_ITER_nopreserve| 299 BTREE_ITER_all_snapshots); 300 prev = bch2_btree_iter_prev(©); 301 if (!prev.k) 302 goto out; 303 304 ret = bkey_err(prev); 305 if (ret) 306 goto out; 307 308 if (bkey_eq(prev.k->p, k.k->p) && 309 bch2_snapshot_is_ancestor(trans->c, iter->snapshot, 310 prev.k->p.snapshot) > 0) { 311 struct printbuf buf1 = PRINTBUF, buf2 = PRINTBUF; 312 313 bch2_bkey_to_text(&buf1, k.k); 314 bch2_bkey_to_text(&buf2, prev.k); 315 316 panic("iter snap %u\n" 317 "k %s\n" 318 "prev %s\n", 319 iter->snapshot, 320 buf1.buf, buf2.buf); 321 } 322 out: 323 bch2_trans_iter_exit(trans, ©); 324 return ret; 325 } 326 327 void bch2_assert_pos_locked(struct btree_trans *trans, enum btree_id id, 328 struct bpos pos) 329 { 330 bch2_trans_verify_not_unlocked(trans); 331 332 struct btree_path *path; 333 struct trans_for_each_path_inorder_iter iter; 334 struct printbuf buf = PRINTBUF; 335 336 btree_trans_sort_paths(trans); 337 338 trans_for_each_path_inorder(trans, path, iter) { 339 if (path->btree_id != id || 340 !btree_node_locked(path, 0) || 341 !path->should_be_locked) 342 continue; 343 344 if (!path->cached) { 345 if (bkey_ge(pos, path->l[0].b->data->min_key) && 346 bkey_le(pos, path->l[0].b->key.k.p)) 347 return; 348 } else { 349 if (bkey_eq(pos, path->pos)) 350 return; 351 } 352 } 353 354 bch2_dump_trans_paths_updates(trans); 355 bch2_bpos_to_text(&buf, pos); 356 357 panic("not locked: %s %s\n", bch2_btree_id_str(id), buf.buf); 358 } 359 360 #else 361 362 static inline void bch2_btree_path_verify_level(struct btree_trans *trans, 363 struct btree_path *path, unsigned l) {} 364 static inline void bch2_btree_path_verify(struct btree_trans *trans, 365 struct btree_path *path) {} 366 static inline void bch2_btree_iter_verify(struct btree_iter *iter) {} 367 static inline void bch2_btree_iter_verify_entry_exit(struct btree_iter *iter) {} 368 static inline int bch2_btree_iter_verify_ret(struct btree_iter *iter, struct bkey_s_c k) { return 0; } 369 370 #endif 371 372 /* Btree path: fixups after btree updates */ 373 374 static void btree_node_iter_set_set_pos(struct btree_node_iter *iter, 375 struct btree *b, 376 struct bset_tree *t, 377 struct bkey_packed *k) 378 { 379 struct btree_node_iter_set *set; 380 381 btree_node_iter_for_each(iter, set) 382 if (set->end == t->end_offset) { 383 set->k = __btree_node_key_to_offset(b, k); 384 bch2_btree_node_iter_sort(iter, b); 385 return; 386 } 387 388 bch2_btree_node_iter_push(iter, b, k, btree_bkey_last(b, t)); 389 } 390 391 static void __bch2_btree_path_fix_key_modified(struct btree_path *path, 392 struct btree *b, 393 struct bkey_packed *where) 394 { 395 struct btree_path_level *l = &path->l[b->c.level]; 396 397 if (where != bch2_btree_node_iter_peek_all(&l->iter, l->b)) 398 return; 399 400 if (bkey_iter_pos_cmp(l->b, where, &path->pos) < 0) 401 bch2_btree_node_iter_advance(&l->iter, l->b); 402 } 403 404 void bch2_btree_path_fix_key_modified(struct btree_trans *trans, 405 struct btree *b, 406 struct bkey_packed *where) 407 { 408 struct btree_path *path; 409 unsigned i; 410 411 trans_for_each_path_with_node(trans, b, path, i) { 412 __bch2_btree_path_fix_key_modified(path, b, where); 413 bch2_btree_path_verify_level(trans, path, b->c.level); 414 } 415 } 416 417 static void __bch2_btree_node_iter_fix(struct btree_path *path, 418 struct btree *b, 419 struct btree_node_iter *node_iter, 420 struct bset_tree *t, 421 struct bkey_packed *where, 422 unsigned clobber_u64s, 423 unsigned new_u64s) 424 { 425 const struct bkey_packed *end = btree_bkey_last(b, t); 426 struct btree_node_iter_set *set; 427 unsigned offset = __btree_node_key_to_offset(b, where); 428 int shift = new_u64s - clobber_u64s; 429 unsigned old_end = t->end_offset - shift; 430 unsigned orig_iter_pos = node_iter->data[0].k; 431 bool iter_current_key_modified = 432 orig_iter_pos >= offset && 433 orig_iter_pos <= offset + clobber_u64s; 434 435 btree_node_iter_for_each(node_iter, set) 436 if (set->end == old_end) 437 goto found; 438 439 /* didn't find the bset in the iterator - might have to readd it: */ 440 if (new_u64s && 441 bkey_iter_pos_cmp(b, where, &path->pos) >= 0) { 442 bch2_btree_node_iter_push(node_iter, b, where, end); 443 goto fixup_done; 444 } else { 445 /* Iterator is after key that changed */ 446 return; 447 } 448 found: 449 set->end = t->end_offset; 450 451 /* Iterator hasn't gotten to the key that changed yet: */ 452 if (set->k < offset) 453 return; 454 455 if (new_u64s && 456 bkey_iter_pos_cmp(b, where, &path->pos) >= 0) { 457 set->k = offset; 458 } else if (set->k < offset + clobber_u64s) { 459 set->k = offset + new_u64s; 460 if (set->k == set->end) 461 bch2_btree_node_iter_set_drop(node_iter, set); 462 } else { 463 /* Iterator is after key that changed */ 464 set->k = (int) set->k + shift; 465 return; 466 } 467 468 bch2_btree_node_iter_sort(node_iter, b); 469 fixup_done: 470 if (node_iter->data[0].k != orig_iter_pos) 471 iter_current_key_modified = true; 472 473 /* 474 * When a new key is added, and the node iterator now points to that 475 * key, the iterator might have skipped past deleted keys that should 476 * come after the key the iterator now points to. We have to rewind to 477 * before those deleted keys - otherwise 478 * bch2_btree_node_iter_prev_all() breaks: 479 */ 480 if (!bch2_btree_node_iter_end(node_iter) && 481 iter_current_key_modified && 482 b->c.level) { 483 struct bkey_packed *k, *k2, *p; 484 485 k = bch2_btree_node_iter_peek_all(node_iter, b); 486 487 for_each_bset(b, t) { 488 bool set_pos = false; 489 490 if (node_iter->data[0].end == t->end_offset) 491 continue; 492 493 k2 = bch2_btree_node_iter_bset_pos(node_iter, b, t); 494 495 while ((p = bch2_bkey_prev_all(b, t, k2)) && 496 bkey_iter_cmp(b, k, p) < 0) { 497 k2 = p; 498 set_pos = true; 499 } 500 501 if (set_pos) 502 btree_node_iter_set_set_pos(node_iter, 503 b, t, k2); 504 } 505 } 506 } 507 508 void bch2_btree_node_iter_fix(struct btree_trans *trans, 509 struct btree_path *path, 510 struct btree *b, 511 struct btree_node_iter *node_iter, 512 struct bkey_packed *where, 513 unsigned clobber_u64s, 514 unsigned new_u64s) 515 { 516 struct bset_tree *t = bch2_bkey_to_bset_inlined(b, where); 517 struct btree_path *linked; 518 unsigned i; 519 520 if (node_iter != &path->l[b->c.level].iter) { 521 __bch2_btree_node_iter_fix(path, b, node_iter, t, 522 where, clobber_u64s, new_u64s); 523 524 if (bch2_debug_check_iterators) 525 bch2_btree_node_iter_verify(node_iter, b); 526 } 527 528 trans_for_each_path_with_node(trans, b, linked, i) { 529 __bch2_btree_node_iter_fix(linked, b, 530 &linked->l[b->c.level].iter, t, 531 where, clobber_u64s, new_u64s); 532 bch2_btree_path_verify_level(trans, linked, b->c.level); 533 } 534 } 535 536 /* Btree path level: pointer to a particular btree node and node iter */ 537 538 static inline struct bkey_s_c __btree_iter_unpack(struct bch_fs *c, 539 struct btree_path_level *l, 540 struct bkey *u, 541 struct bkey_packed *k) 542 { 543 if (unlikely(!k)) { 544 /* 545 * signal to bch2_btree_iter_peek_slot() that we're currently at 546 * a hole 547 */ 548 u->type = KEY_TYPE_deleted; 549 return bkey_s_c_null; 550 } 551 552 return bkey_disassemble(l->b, k, u); 553 } 554 555 static inline struct bkey_s_c btree_path_level_peek_all(struct bch_fs *c, 556 struct btree_path_level *l, 557 struct bkey *u) 558 { 559 return __btree_iter_unpack(c, l, u, 560 bch2_btree_node_iter_peek_all(&l->iter, l->b)); 561 } 562 563 static inline struct bkey_s_c btree_path_level_peek(struct btree_trans *trans, 564 struct btree_path *path, 565 struct btree_path_level *l, 566 struct bkey *u) 567 { 568 struct bkey_s_c k = __btree_iter_unpack(trans->c, l, u, 569 bch2_btree_node_iter_peek(&l->iter, l->b)); 570 571 path->pos = k.k ? k.k->p : l->b->key.k.p; 572 trans->paths_sorted = false; 573 bch2_btree_path_verify_level(trans, path, l - path->l); 574 return k; 575 } 576 577 static inline struct bkey_s_c btree_path_level_prev(struct btree_trans *trans, 578 struct btree_path *path, 579 struct btree_path_level *l, 580 struct bkey *u) 581 { 582 struct bkey_s_c k = __btree_iter_unpack(trans->c, l, u, 583 bch2_btree_node_iter_prev(&l->iter, l->b)); 584 585 path->pos = k.k ? k.k->p : l->b->data->min_key; 586 trans->paths_sorted = false; 587 bch2_btree_path_verify_level(trans, path, l - path->l); 588 return k; 589 } 590 591 static inline bool btree_path_advance_to_pos(struct btree_path *path, 592 struct btree_path_level *l, 593 int max_advance) 594 { 595 struct bkey_packed *k; 596 int nr_advanced = 0; 597 598 while ((k = bch2_btree_node_iter_peek_all(&l->iter, l->b)) && 599 bkey_iter_pos_cmp(l->b, k, &path->pos) < 0) { 600 if (max_advance > 0 && nr_advanced >= max_advance) 601 return false; 602 603 bch2_btree_node_iter_advance(&l->iter, l->b); 604 nr_advanced++; 605 } 606 607 return true; 608 } 609 610 static inline void __btree_path_level_init(struct btree_path *path, 611 unsigned level) 612 { 613 struct btree_path_level *l = &path->l[level]; 614 615 bch2_btree_node_iter_init(&l->iter, l->b, &path->pos); 616 617 /* 618 * Iterators to interior nodes should always be pointed at the first non 619 * whiteout: 620 */ 621 if (level) 622 bch2_btree_node_iter_peek(&l->iter, l->b); 623 } 624 625 void bch2_btree_path_level_init(struct btree_trans *trans, 626 struct btree_path *path, 627 struct btree *b) 628 { 629 BUG_ON(path->cached); 630 631 EBUG_ON(!btree_path_pos_in_node(path, b)); 632 633 path->l[b->c.level].lock_seq = six_lock_seq(&b->c.lock); 634 path->l[b->c.level].b = b; 635 __btree_path_level_init(path, b->c.level); 636 } 637 638 /* Btree path: fixups after btree node updates: */ 639 640 static void bch2_trans_revalidate_updates_in_node(struct btree_trans *trans, struct btree *b) 641 { 642 struct bch_fs *c = trans->c; 643 644 trans_for_each_update(trans, i) 645 if (!i->cached && 646 i->level == b->c.level && 647 i->btree_id == b->c.btree_id && 648 bpos_cmp(i->k->k.p, b->data->min_key) >= 0 && 649 bpos_cmp(i->k->k.p, b->data->max_key) <= 0) { 650 i->old_v = bch2_btree_path_peek_slot(trans->paths + i->path, &i->old_k).v; 651 652 if (unlikely(trans->journal_replay_not_finished)) { 653 struct bkey_i *j_k = 654 bch2_journal_keys_peek_slot(c, i->btree_id, i->level, 655 i->k->k.p); 656 657 if (j_k) { 658 i->old_k = j_k->k; 659 i->old_v = &j_k->v; 660 } 661 } 662 } 663 } 664 665 /* 666 * A btree node is being replaced - update the iterator to point to the new 667 * node: 668 */ 669 void bch2_trans_node_add(struct btree_trans *trans, 670 struct btree_path *path, 671 struct btree *b) 672 { 673 struct btree_path *prev; 674 675 BUG_ON(!btree_path_pos_in_node(path, b)); 676 677 while ((prev = prev_btree_path(trans, path)) && 678 btree_path_pos_in_node(prev, b)) 679 path = prev; 680 681 for (; 682 path && btree_path_pos_in_node(path, b); 683 path = next_btree_path(trans, path)) 684 if (path->uptodate == BTREE_ITER_UPTODATE && !path->cached) { 685 enum btree_node_locked_type t = 686 btree_lock_want(path, b->c.level); 687 688 if (t != BTREE_NODE_UNLOCKED) { 689 btree_node_unlock(trans, path, b->c.level); 690 six_lock_increment(&b->c.lock, (enum six_lock_type) t); 691 mark_btree_node_locked(trans, path, b->c.level, t); 692 } 693 694 bch2_btree_path_level_init(trans, path, b); 695 } 696 697 bch2_trans_revalidate_updates_in_node(trans, b); 698 } 699 700 /* 701 * A btree node has been modified in such a way as to invalidate iterators - fix 702 * them: 703 */ 704 void bch2_trans_node_reinit_iter(struct btree_trans *trans, struct btree *b) 705 { 706 struct btree_path *path; 707 unsigned i; 708 709 trans_for_each_path_with_node(trans, b, path, i) 710 __btree_path_level_init(path, b->c.level); 711 712 bch2_trans_revalidate_updates_in_node(trans, b); 713 } 714 715 /* Btree path: traverse, set_pos: */ 716 717 static inline int btree_path_lock_root(struct btree_trans *trans, 718 struct btree_path *path, 719 unsigned depth_want, 720 unsigned long trace_ip) 721 { 722 struct bch_fs *c = trans->c; 723 struct btree *b, **rootp = &bch2_btree_id_root(c, path->btree_id)->b; 724 enum six_lock_type lock_type; 725 unsigned i; 726 int ret; 727 728 EBUG_ON(path->nodes_locked); 729 730 while (1) { 731 b = READ_ONCE(*rootp); 732 path->level = READ_ONCE(b->c.level); 733 734 if (unlikely(path->level < depth_want)) { 735 /* 736 * the root is at a lower depth than the depth we want: 737 * got to the end of the btree, or we're walking nodes 738 * greater than some depth and there are no nodes >= 739 * that depth 740 */ 741 path->level = depth_want; 742 for (i = path->level; i < BTREE_MAX_DEPTH; i++) 743 path->l[i].b = NULL; 744 return 1; 745 } 746 747 lock_type = __btree_lock_want(path, path->level); 748 ret = btree_node_lock(trans, path, &b->c, 749 path->level, lock_type, trace_ip); 750 if (unlikely(ret)) { 751 if (bch2_err_matches(ret, BCH_ERR_lock_fail_root_changed)) 752 continue; 753 if (bch2_err_matches(ret, BCH_ERR_transaction_restart)) 754 return ret; 755 BUG(); 756 } 757 758 if (likely(b == READ_ONCE(*rootp) && 759 b->c.level == path->level && 760 !race_fault())) { 761 for (i = 0; i < path->level; i++) 762 path->l[i].b = ERR_PTR(-BCH_ERR_no_btree_node_lock_root); 763 path->l[path->level].b = b; 764 for (i = path->level + 1; i < BTREE_MAX_DEPTH; i++) 765 path->l[i].b = NULL; 766 767 mark_btree_node_locked(trans, path, path->level, 768 (enum btree_node_locked_type) lock_type); 769 bch2_btree_path_level_init(trans, path, b); 770 return 0; 771 } 772 773 six_unlock_type(&b->c.lock, lock_type); 774 } 775 } 776 777 noinline 778 static int btree_path_prefetch(struct btree_trans *trans, struct btree_path *path) 779 { 780 struct bch_fs *c = trans->c; 781 struct btree_path_level *l = path_l(path); 782 struct btree_node_iter node_iter = l->iter; 783 struct bkey_packed *k; 784 struct bkey_buf tmp; 785 unsigned nr = test_bit(BCH_FS_started, &c->flags) 786 ? (path->level > 1 ? 0 : 2) 787 : (path->level > 1 ? 1 : 16); 788 bool was_locked = btree_node_locked(path, path->level); 789 int ret = 0; 790 791 bch2_bkey_buf_init(&tmp); 792 793 while (nr-- && !ret) { 794 if (!bch2_btree_node_relock(trans, path, path->level)) 795 break; 796 797 bch2_btree_node_iter_advance(&node_iter, l->b); 798 k = bch2_btree_node_iter_peek(&node_iter, l->b); 799 if (!k) 800 break; 801 802 bch2_bkey_buf_unpack(&tmp, c, l->b, k); 803 ret = bch2_btree_node_prefetch(trans, path, tmp.k, path->btree_id, 804 path->level - 1); 805 } 806 807 if (!was_locked) 808 btree_node_unlock(trans, path, path->level); 809 810 bch2_bkey_buf_exit(&tmp, c); 811 return ret; 812 } 813 814 static int btree_path_prefetch_j(struct btree_trans *trans, struct btree_path *path, 815 struct btree_and_journal_iter *jiter) 816 { 817 struct bch_fs *c = trans->c; 818 struct bkey_s_c k; 819 struct bkey_buf tmp; 820 unsigned nr = test_bit(BCH_FS_started, &c->flags) 821 ? (path->level > 1 ? 0 : 2) 822 : (path->level > 1 ? 1 : 16); 823 bool was_locked = btree_node_locked(path, path->level); 824 int ret = 0; 825 826 bch2_bkey_buf_init(&tmp); 827 828 while (nr-- && !ret) { 829 if (!bch2_btree_node_relock(trans, path, path->level)) 830 break; 831 832 bch2_btree_and_journal_iter_advance(jiter); 833 k = bch2_btree_and_journal_iter_peek(jiter); 834 if (!k.k) 835 break; 836 837 bch2_bkey_buf_reassemble(&tmp, c, k); 838 ret = bch2_btree_node_prefetch(trans, path, tmp.k, path->btree_id, 839 path->level - 1); 840 } 841 842 if (!was_locked) 843 btree_node_unlock(trans, path, path->level); 844 845 bch2_bkey_buf_exit(&tmp, c); 846 return ret; 847 } 848 849 static noinline void btree_node_mem_ptr_set(struct btree_trans *trans, 850 struct btree_path *path, 851 unsigned plevel, struct btree *b) 852 { 853 struct btree_path_level *l = &path->l[plevel]; 854 bool locked = btree_node_locked(path, plevel); 855 struct bkey_packed *k; 856 struct bch_btree_ptr_v2 *bp; 857 858 if (!bch2_btree_node_relock(trans, path, plevel)) 859 return; 860 861 k = bch2_btree_node_iter_peek_all(&l->iter, l->b); 862 BUG_ON(k->type != KEY_TYPE_btree_ptr_v2); 863 864 bp = (void *) bkeyp_val(&l->b->format, k); 865 bp->mem_ptr = (unsigned long)b; 866 867 if (!locked) 868 btree_node_unlock(trans, path, plevel); 869 } 870 871 static noinline int btree_node_iter_and_journal_peek(struct btree_trans *trans, 872 struct btree_path *path, 873 unsigned flags, 874 struct bkey_buf *out) 875 { 876 struct bch_fs *c = trans->c; 877 struct btree_path_level *l = path_l(path); 878 struct btree_and_journal_iter jiter; 879 struct bkey_s_c k; 880 int ret = 0; 881 882 __bch2_btree_and_journal_iter_init_node_iter(trans, &jiter, l->b, l->iter, path->pos); 883 884 k = bch2_btree_and_journal_iter_peek(&jiter); 885 886 bch2_bkey_buf_reassemble(out, c, k); 887 888 if ((flags & BTREE_ITER_prefetch) && 889 c->opts.btree_node_prefetch) 890 ret = btree_path_prefetch_j(trans, path, &jiter); 891 892 bch2_btree_and_journal_iter_exit(&jiter); 893 return ret; 894 } 895 896 static __always_inline int btree_path_down(struct btree_trans *trans, 897 struct btree_path *path, 898 unsigned flags, 899 unsigned long trace_ip) 900 { 901 struct bch_fs *c = trans->c; 902 struct btree_path_level *l = path_l(path); 903 struct btree *b; 904 unsigned level = path->level - 1; 905 enum six_lock_type lock_type = __btree_lock_want(path, level); 906 struct bkey_buf tmp; 907 int ret; 908 909 EBUG_ON(!btree_node_locked(path, path->level)); 910 911 bch2_bkey_buf_init(&tmp); 912 913 if (unlikely(trans->journal_replay_not_finished)) { 914 ret = btree_node_iter_and_journal_peek(trans, path, flags, &tmp); 915 if (ret) 916 goto err; 917 } else { 918 struct bkey_packed *k = bch2_btree_node_iter_peek(&l->iter, l->b); 919 if (!k) { 920 struct printbuf buf = PRINTBUF; 921 922 prt_str(&buf, "node not found at pos "); 923 bch2_bpos_to_text(&buf, path->pos); 924 prt_str(&buf, " within parent node "); 925 bch2_bkey_val_to_text(&buf, c, bkey_i_to_s_c(&l->b->key)); 926 927 bch2_fs_fatal_error(c, "%s", buf.buf); 928 printbuf_exit(&buf); 929 ret = -BCH_ERR_btree_need_topology_repair; 930 goto err; 931 } 932 933 bch2_bkey_buf_unpack(&tmp, c, l->b, k); 934 935 if ((flags & BTREE_ITER_prefetch) && 936 c->opts.btree_node_prefetch) { 937 ret = btree_path_prefetch(trans, path); 938 if (ret) 939 goto err; 940 } 941 } 942 943 b = bch2_btree_node_get(trans, path, tmp.k, level, lock_type, trace_ip); 944 ret = PTR_ERR_OR_ZERO(b); 945 if (unlikely(ret)) 946 goto err; 947 948 if (likely(!trans->journal_replay_not_finished && 949 tmp.k->k.type == KEY_TYPE_btree_ptr_v2) && 950 unlikely(b != btree_node_mem_ptr(tmp.k))) 951 btree_node_mem_ptr_set(trans, path, level + 1, b); 952 953 if (btree_node_read_locked(path, level + 1)) 954 btree_node_unlock(trans, path, level + 1); 955 956 mark_btree_node_locked(trans, path, level, 957 (enum btree_node_locked_type) lock_type); 958 path->level = level; 959 bch2_btree_path_level_init(trans, path, b); 960 961 bch2_btree_path_verify_locks(path); 962 err: 963 bch2_bkey_buf_exit(&tmp, c); 964 return ret; 965 } 966 967 static int bch2_btree_path_traverse_all(struct btree_trans *trans) 968 { 969 struct bch_fs *c = trans->c; 970 struct btree_path *path; 971 unsigned long trace_ip = _RET_IP_; 972 unsigned i; 973 int ret = 0; 974 975 if (trans->in_traverse_all) 976 return -BCH_ERR_transaction_restart_in_traverse_all; 977 978 trans->in_traverse_all = true; 979 retry_all: 980 trans->restarted = 0; 981 trans->last_restarted_ip = 0; 982 983 trans_for_each_path(trans, path, i) 984 path->should_be_locked = false; 985 986 btree_trans_sort_paths(trans); 987 988 bch2_trans_unlock(trans); 989 cond_resched(); 990 trans_set_locked(trans); 991 992 if (unlikely(trans->memory_allocation_failure)) { 993 struct closure cl; 994 995 closure_init_stack(&cl); 996 997 do { 998 ret = bch2_btree_cache_cannibalize_lock(trans, &cl); 999 closure_sync(&cl); 1000 } while (ret); 1001 } 1002 1003 /* Now, redo traversals in correct order: */ 1004 i = 0; 1005 while (i < trans->nr_sorted) { 1006 btree_path_idx_t idx = trans->sorted[i]; 1007 1008 /* 1009 * Traversing a path can cause another path to be added at about 1010 * the same position: 1011 */ 1012 if (trans->paths[idx].uptodate) { 1013 __btree_path_get(trans, &trans->paths[idx], false); 1014 ret = bch2_btree_path_traverse_one(trans, idx, 0, _THIS_IP_); 1015 __btree_path_put(trans, &trans->paths[idx], false); 1016 1017 if (bch2_err_matches(ret, BCH_ERR_transaction_restart) || 1018 bch2_err_matches(ret, ENOMEM)) 1019 goto retry_all; 1020 if (ret) 1021 goto err; 1022 } else { 1023 i++; 1024 } 1025 } 1026 1027 /* 1028 * We used to assert that all paths had been traversed here 1029 * (path->uptodate < BTREE_ITER_NEED_TRAVERSE); however, since 1030 * path->should_be_locked is not set yet, we might have unlocked and 1031 * then failed to relock a path - that's fine. 1032 */ 1033 err: 1034 bch2_btree_cache_cannibalize_unlock(trans); 1035 1036 trans->in_traverse_all = false; 1037 1038 trace_and_count(c, trans_traverse_all, trans, trace_ip); 1039 return ret; 1040 } 1041 1042 static inline bool btree_path_check_pos_in_node(struct btree_path *path, 1043 unsigned l, int check_pos) 1044 { 1045 if (check_pos < 0 && btree_path_pos_before_node(path, path->l[l].b)) 1046 return false; 1047 if (check_pos > 0 && btree_path_pos_after_node(path, path->l[l].b)) 1048 return false; 1049 return true; 1050 } 1051 1052 static inline bool btree_path_good_node(struct btree_trans *trans, 1053 struct btree_path *path, 1054 unsigned l, int check_pos) 1055 { 1056 return is_btree_node(path, l) && 1057 bch2_btree_node_relock(trans, path, l) && 1058 btree_path_check_pos_in_node(path, l, check_pos); 1059 } 1060 1061 static void btree_path_set_level_down(struct btree_trans *trans, 1062 struct btree_path *path, 1063 unsigned new_level) 1064 { 1065 unsigned l; 1066 1067 path->level = new_level; 1068 1069 for (l = path->level + 1; l < BTREE_MAX_DEPTH; l++) 1070 if (btree_lock_want(path, l) == BTREE_NODE_UNLOCKED) 1071 btree_node_unlock(trans, path, l); 1072 1073 btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE); 1074 bch2_btree_path_verify(trans, path); 1075 } 1076 1077 static noinline unsigned __btree_path_up_until_good_node(struct btree_trans *trans, 1078 struct btree_path *path, 1079 int check_pos) 1080 { 1081 unsigned i, l = path->level; 1082 again: 1083 while (btree_path_node(path, l) && 1084 !btree_path_good_node(trans, path, l, check_pos)) 1085 __btree_path_set_level_up(trans, path, l++); 1086 1087 /* If we need intent locks, take them too: */ 1088 for (i = l + 1; 1089 i < path->locks_want && btree_path_node(path, i); 1090 i++) 1091 if (!bch2_btree_node_relock(trans, path, i)) { 1092 while (l <= i) 1093 __btree_path_set_level_up(trans, path, l++); 1094 goto again; 1095 } 1096 1097 return l; 1098 } 1099 1100 static inline unsigned btree_path_up_until_good_node(struct btree_trans *trans, 1101 struct btree_path *path, 1102 int check_pos) 1103 { 1104 return likely(btree_node_locked(path, path->level) && 1105 btree_path_check_pos_in_node(path, path->level, check_pos)) 1106 ? path->level 1107 : __btree_path_up_until_good_node(trans, path, check_pos); 1108 } 1109 1110 /* 1111 * This is the main state machine for walking down the btree - walks down to a 1112 * specified depth 1113 * 1114 * Returns 0 on success, -EIO on error (error reading in a btree node). 1115 * 1116 * On error, caller (peek_node()/peek_key()) must return NULL; the error is 1117 * stashed in the iterator and returned from bch2_trans_exit(). 1118 */ 1119 int bch2_btree_path_traverse_one(struct btree_trans *trans, 1120 btree_path_idx_t path_idx, 1121 unsigned flags, 1122 unsigned long trace_ip) 1123 { 1124 struct btree_path *path = &trans->paths[path_idx]; 1125 unsigned depth_want = path->level; 1126 int ret = -((int) trans->restarted); 1127 1128 if (unlikely(ret)) 1129 goto out; 1130 1131 if (unlikely(!trans->srcu_held)) 1132 bch2_trans_srcu_lock(trans); 1133 1134 trace_btree_path_traverse_start(trans, path); 1135 1136 /* 1137 * Ensure we obey path->should_be_locked: if it's set, we can't unlock 1138 * and re-traverse the path without a transaction restart: 1139 */ 1140 if (path->should_be_locked) { 1141 ret = bch2_btree_path_relock(trans, path, trace_ip); 1142 goto out; 1143 } 1144 1145 if (path->cached) { 1146 ret = bch2_btree_path_traverse_cached(trans, path, flags); 1147 goto out; 1148 } 1149 1150 path = &trans->paths[path_idx]; 1151 1152 if (unlikely(path->level >= BTREE_MAX_DEPTH)) 1153 goto out_uptodate; 1154 1155 path->level = btree_path_up_until_good_node(trans, path, 0); 1156 unsigned max_level = path->level; 1157 1158 EBUG_ON(btree_path_node(path, path->level) && 1159 !btree_node_locked(path, path->level)); 1160 1161 /* 1162 * Note: path->nodes[path->level] may be temporarily NULL here - that 1163 * would indicate to other code that we got to the end of the btree, 1164 * here it indicates that relocking the root failed - it's critical that 1165 * btree_path_lock_root() comes next and that it can't fail 1166 */ 1167 while (path->level > depth_want) { 1168 ret = btree_path_node(path, path->level) 1169 ? btree_path_down(trans, path, flags, trace_ip) 1170 : btree_path_lock_root(trans, path, depth_want, trace_ip); 1171 if (unlikely(ret)) { 1172 if (ret == 1) { 1173 /* 1174 * No nodes at this level - got to the end of 1175 * the btree: 1176 */ 1177 ret = 0; 1178 goto out; 1179 } 1180 1181 __bch2_btree_path_unlock(trans, path); 1182 path->level = depth_want; 1183 path->l[path->level].b = ERR_PTR(ret); 1184 goto out; 1185 } 1186 } 1187 1188 if (unlikely(max_level > path->level)) { 1189 struct btree_path *linked; 1190 unsigned iter; 1191 1192 trans_for_each_path_with_node(trans, path_l(path)->b, linked, iter) 1193 for (unsigned j = path->level + 1; j < max_level; j++) 1194 linked->l[j] = path->l[j]; 1195 } 1196 1197 out_uptodate: 1198 path->uptodate = BTREE_ITER_UPTODATE; 1199 trace_btree_path_traverse_end(trans, path); 1200 out: 1201 if (bch2_err_matches(ret, BCH_ERR_transaction_restart) != !!trans->restarted) 1202 panic("ret %s (%i) trans->restarted %s (%i)\n", 1203 bch2_err_str(ret), ret, 1204 bch2_err_str(trans->restarted), trans->restarted); 1205 bch2_btree_path_verify(trans, path); 1206 return ret; 1207 } 1208 1209 static inline void btree_path_copy(struct btree_trans *trans, struct btree_path *dst, 1210 struct btree_path *src) 1211 { 1212 unsigned i, offset = offsetof(struct btree_path, pos); 1213 1214 memcpy((void *) dst + offset, 1215 (void *) src + offset, 1216 sizeof(struct btree_path) - offset); 1217 1218 for (i = 0; i < BTREE_MAX_DEPTH; i++) { 1219 unsigned t = btree_node_locked_type(dst, i); 1220 1221 if (t != BTREE_NODE_UNLOCKED) 1222 six_lock_increment(&dst->l[i].b->c.lock, t); 1223 } 1224 } 1225 1226 static btree_path_idx_t btree_path_clone(struct btree_trans *trans, btree_path_idx_t src, 1227 bool intent, unsigned long ip) 1228 { 1229 btree_path_idx_t new = btree_path_alloc(trans, src); 1230 btree_path_copy(trans, trans->paths + new, trans->paths + src); 1231 __btree_path_get(trans, trans->paths + new, intent); 1232 #ifdef TRACK_PATH_ALLOCATED 1233 trans->paths[new].ip_allocated = ip; 1234 #endif 1235 return new; 1236 } 1237 1238 __flatten 1239 btree_path_idx_t __bch2_btree_path_make_mut(struct btree_trans *trans, 1240 btree_path_idx_t path, bool intent, unsigned long ip) 1241 { 1242 struct btree_path *old = trans->paths + path; 1243 __btree_path_put(trans, trans->paths + path, intent); 1244 path = btree_path_clone(trans, path, intent, ip); 1245 trace_btree_path_clone(trans, old, trans->paths + path); 1246 trans->paths[path].preserve = false; 1247 return path; 1248 } 1249 1250 btree_path_idx_t __must_check 1251 __bch2_btree_path_set_pos(struct btree_trans *trans, 1252 btree_path_idx_t path_idx, struct bpos new_pos, 1253 bool intent, unsigned long ip) 1254 { 1255 int cmp = bpos_cmp(new_pos, trans->paths[path_idx].pos); 1256 1257 bch2_trans_verify_not_in_restart(trans); 1258 EBUG_ON(!trans->paths[path_idx].ref); 1259 1260 trace_btree_path_set_pos(trans, trans->paths + path_idx, &new_pos); 1261 1262 path_idx = bch2_btree_path_make_mut(trans, path_idx, intent, ip); 1263 1264 struct btree_path *path = trans->paths + path_idx; 1265 path->pos = new_pos; 1266 trans->paths_sorted = false; 1267 1268 if (unlikely(path->cached)) { 1269 btree_node_unlock(trans, path, 0); 1270 path->l[0].b = ERR_PTR(-BCH_ERR_no_btree_node_up); 1271 btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE); 1272 goto out; 1273 } 1274 1275 unsigned level = btree_path_up_until_good_node(trans, path, cmp); 1276 1277 if (btree_path_node(path, level)) { 1278 struct btree_path_level *l = &path->l[level]; 1279 1280 BUG_ON(!btree_node_locked(path, level)); 1281 /* 1282 * We might have to skip over many keys, or just a few: try 1283 * advancing the node iterator, and if we have to skip over too 1284 * many keys just reinit it (or if we're rewinding, since that 1285 * is expensive). 1286 */ 1287 if (cmp < 0 || 1288 !btree_path_advance_to_pos(path, l, 8)) 1289 bch2_btree_node_iter_init(&l->iter, l->b, &path->pos); 1290 1291 /* 1292 * Iterators to interior nodes should always be pointed at the first non 1293 * whiteout: 1294 */ 1295 if (unlikely(level)) 1296 bch2_btree_node_iter_peek(&l->iter, l->b); 1297 } 1298 1299 if (unlikely(level != path->level)) { 1300 btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE); 1301 __bch2_btree_path_unlock(trans, path); 1302 } 1303 out: 1304 bch2_btree_path_verify(trans, path); 1305 return path_idx; 1306 } 1307 1308 /* Btree path: main interface: */ 1309 1310 static struct btree_path *have_path_at_pos(struct btree_trans *trans, struct btree_path *path) 1311 { 1312 struct btree_path *sib; 1313 1314 sib = prev_btree_path(trans, path); 1315 if (sib && !btree_path_cmp(sib, path)) 1316 return sib; 1317 1318 sib = next_btree_path(trans, path); 1319 if (sib && !btree_path_cmp(sib, path)) 1320 return sib; 1321 1322 return NULL; 1323 } 1324 1325 static struct btree_path *have_node_at_pos(struct btree_trans *trans, struct btree_path *path) 1326 { 1327 struct btree_path *sib; 1328 1329 sib = prev_btree_path(trans, path); 1330 if (sib && sib->level == path->level && path_l(sib)->b == path_l(path)->b) 1331 return sib; 1332 1333 sib = next_btree_path(trans, path); 1334 if (sib && sib->level == path->level && path_l(sib)->b == path_l(path)->b) 1335 return sib; 1336 1337 return NULL; 1338 } 1339 1340 static inline void __bch2_path_free(struct btree_trans *trans, btree_path_idx_t path) 1341 { 1342 __bch2_btree_path_unlock(trans, trans->paths + path); 1343 btree_path_list_remove(trans, trans->paths + path); 1344 __clear_bit(path, trans->paths_allocated); 1345 } 1346 1347 static bool bch2_btree_path_can_relock(struct btree_trans *trans, struct btree_path *path) 1348 { 1349 unsigned l = path->level; 1350 1351 do { 1352 if (!btree_path_node(path, l)) 1353 break; 1354 1355 if (!is_btree_node(path, l)) 1356 return false; 1357 1358 if (path->l[l].lock_seq != path->l[l].b->c.lock.seq) 1359 return false; 1360 1361 l++; 1362 } while (l < path->locks_want); 1363 1364 return true; 1365 } 1366 1367 void bch2_path_put(struct btree_trans *trans, btree_path_idx_t path_idx, bool intent) 1368 { 1369 struct btree_path *path = trans->paths + path_idx, *dup; 1370 1371 if (!__btree_path_put(trans, path, intent)) 1372 return; 1373 1374 dup = path->preserve 1375 ? have_path_at_pos(trans, path) 1376 : have_node_at_pos(trans, path); 1377 1378 trace_btree_path_free(trans, path_idx, dup); 1379 1380 if (!dup && !(!path->preserve && !is_btree_node(path, path->level))) 1381 return; 1382 1383 if (path->should_be_locked && !trans->restarted) { 1384 if (!dup) 1385 return; 1386 1387 if (!(trans->locked 1388 ? bch2_btree_path_relock_norestart(trans, dup) 1389 : bch2_btree_path_can_relock(trans, dup))) 1390 return; 1391 } 1392 1393 if (dup) { 1394 dup->preserve |= path->preserve; 1395 dup->should_be_locked |= path->should_be_locked; 1396 } 1397 1398 __bch2_path_free(trans, path_idx); 1399 } 1400 1401 static void bch2_path_put_nokeep(struct btree_trans *trans, btree_path_idx_t path, 1402 bool intent) 1403 { 1404 if (!__btree_path_put(trans, trans->paths + path, intent)) 1405 return; 1406 1407 __bch2_path_free(trans, path); 1408 } 1409 1410 void __noreturn bch2_trans_restart_error(struct btree_trans *trans, u32 restart_count) 1411 { 1412 panic("trans->restart_count %u, should be %u, last restarted by %pS\n", 1413 trans->restart_count, restart_count, 1414 (void *) trans->last_begin_ip); 1415 } 1416 1417 void __noreturn bch2_trans_in_restart_error(struct btree_trans *trans) 1418 { 1419 panic("in transaction restart: %s, last restarted by %pS\n", 1420 bch2_err_str(trans->restarted), 1421 (void *) trans->last_restarted_ip); 1422 } 1423 1424 void __noreturn bch2_trans_unlocked_error(struct btree_trans *trans) 1425 { 1426 panic("trans should be locked, unlocked by %pS\n", 1427 (void *) trans->last_unlock_ip); 1428 } 1429 1430 noinline __cold 1431 void bch2_trans_updates_to_text(struct printbuf *buf, struct btree_trans *trans) 1432 { 1433 prt_printf(buf, "%u transaction updates for %s journal seq %llu\n", 1434 trans->nr_updates, trans->fn, trans->journal_res.seq); 1435 printbuf_indent_add(buf, 2); 1436 1437 trans_for_each_update(trans, i) { 1438 struct bkey_s_c old = { &i->old_k, i->old_v }; 1439 1440 prt_printf(buf, "update: btree=%s cached=%u %pS\n", 1441 bch2_btree_id_str(i->btree_id), 1442 i->cached, 1443 (void *) i->ip_allocated); 1444 1445 prt_printf(buf, " old "); 1446 bch2_bkey_val_to_text(buf, trans->c, old); 1447 prt_newline(buf); 1448 1449 prt_printf(buf, " new "); 1450 bch2_bkey_val_to_text(buf, trans->c, bkey_i_to_s_c(i->k)); 1451 prt_newline(buf); 1452 } 1453 1454 for (struct jset_entry *e = trans->journal_entries; 1455 e != btree_trans_journal_entries_top(trans); 1456 e = vstruct_next(e)) 1457 bch2_journal_entry_to_text(buf, trans->c, e); 1458 1459 printbuf_indent_sub(buf, 2); 1460 } 1461 1462 noinline __cold 1463 void bch2_dump_trans_updates(struct btree_trans *trans) 1464 { 1465 struct printbuf buf = PRINTBUF; 1466 1467 bch2_trans_updates_to_text(&buf, trans); 1468 bch2_print_str(trans->c, buf.buf); 1469 printbuf_exit(&buf); 1470 } 1471 1472 static void bch2_btree_path_to_text_short(struct printbuf *out, struct btree_trans *trans, btree_path_idx_t path_idx) 1473 { 1474 struct btree_path *path = trans->paths + path_idx; 1475 1476 prt_printf(out, "path: idx %3u ref %u:%u %c %c %c btree=%s l=%u pos ", 1477 path_idx, path->ref, path->intent_ref, 1478 path->preserve ? 'P' : ' ', 1479 path->should_be_locked ? 'S' : ' ', 1480 path->cached ? 'C' : 'B', 1481 bch2_btree_id_str(path->btree_id), 1482 path->level); 1483 bch2_bpos_to_text(out, path->pos); 1484 1485 if (!path->cached && btree_node_locked(path, path->level)) { 1486 prt_char(out, ' '); 1487 struct btree *b = path_l(path)->b; 1488 bch2_bpos_to_text(out, b->data->min_key); 1489 prt_char(out, '-'); 1490 bch2_bpos_to_text(out, b->key.k.p); 1491 } 1492 1493 #ifdef TRACK_PATH_ALLOCATED 1494 prt_printf(out, " %pS", (void *) path->ip_allocated); 1495 #endif 1496 } 1497 1498 static const char *btree_node_locked_str(enum btree_node_locked_type t) 1499 { 1500 switch (t) { 1501 case BTREE_NODE_UNLOCKED: 1502 return "unlocked"; 1503 case BTREE_NODE_READ_LOCKED: 1504 return "read"; 1505 case BTREE_NODE_INTENT_LOCKED: 1506 return "intent"; 1507 case BTREE_NODE_WRITE_LOCKED: 1508 return "write"; 1509 default: 1510 return NULL; 1511 } 1512 } 1513 1514 void bch2_btree_path_to_text(struct printbuf *out, struct btree_trans *trans, btree_path_idx_t path_idx) 1515 { 1516 bch2_btree_path_to_text_short(out, trans, path_idx); 1517 1518 struct btree_path *path = trans->paths + path_idx; 1519 1520 prt_printf(out, " uptodate %u locks_want %u", path->uptodate, path->locks_want); 1521 prt_newline(out); 1522 1523 printbuf_indent_add(out, 2); 1524 for (unsigned l = 0; l < BTREE_MAX_DEPTH; l++) { 1525 prt_printf(out, "l=%u locks %s seq %u node ", l, 1526 btree_node_locked_str(btree_node_locked_type(path, l)), 1527 path->l[l].lock_seq); 1528 1529 int ret = PTR_ERR_OR_ZERO(path->l[l].b); 1530 if (ret) 1531 prt_str(out, bch2_err_str(ret)); 1532 else 1533 prt_printf(out, "%px", path->l[l].b); 1534 prt_newline(out); 1535 } 1536 printbuf_indent_sub(out, 2); 1537 } 1538 1539 static noinline __cold 1540 void __bch2_trans_paths_to_text(struct printbuf *out, struct btree_trans *trans, 1541 bool nosort) 1542 { 1543 struct trans_for_each_path_inorder_iter iter; 1544 1545 if (!nosort) 1546 btree_trans_sort_paths(trans); 1547 1548 trans_for_each_path_idx_inorder(trans, iter) { 1549 bch2_btree_path_to_text_short(out, trans, iter.path_idx); 1550 prt_newline(out); 1551 } 1552 } 1553 1554 noinline __cold 1555 void bch2_trans_paths_to_text(struct printbuf *out, struct btree_trans *trans) 1556 { 1557 __bch2_trans_paths_to_text(out, trans, false); 1558 } 1559 1560 static noinline __cold 1561 void __bch2_dump_trans_paths_updates(struct btree_trans *trans, bool nosort) 1562 { 1563 struct printbuf buf = PRINTBUF; 1564 1565 __bch2_trans_paths_to_text(&buf, trans, nosort); 1566 bch2_trans_updates_to_text(&buf, trans); 1567 1568 bch2_print_str(trans->c, buf.buf); 1569 printbuf_exit(&buf); 1570 } 1571 1572 noinline __cold 1573 void bch2_dump_trans_paths_updates(struct btree_trans *trans) 1574 { 1575 __bch2_dump_trans_paths_updates(trans, false); 1576 } 1577 1578 noinline __cold 1579 static void bch2_trans_update_max_paths(struct btree_trans *trans) 1580 { 1581 struct btree_transaction_stats *s = btree_trans_stats(trans); 1582 struct printbuf buf = PRINTBUF; 1583 size_t nr = bitmap_weight(trans->paths_allocated, trans->nr_paths); 1584 1585 bch2_trans_paths_to_text(&buf, trans); 1586 1587 if (!buf.allocation_failure) { 1588 mutex_lock(&s->lock); 1589 if (nr > s->nr_max_paths) { 1590 s->nr_max_paths = nr; 1591 swap(s->max_paths_text, buf.buf); 1592 } 1593 mutex_unlock(&s->lock); 1594 } 1595 1596 printbuf_exit(&buf); 1597 1598 trans->nr_paths_max = nr; 1599 } 1600 1601 noinline __cold 1602 int __bch2_btree_trans_too_many_iters(struct btree_trans *trans) 1603 { 1604 if (trace_trans_restart_too_many_iters_enabled()) { 1605 struct printbuf buf = PRINTBUF; 1606 1607 bch2_trans_paths_to_text(&buf, trans); 1608 trace_trans_restart_too_many_iters(trans, _THIS_IP_, buf.buf); 1609 printbuf_exit(&buf); 1610 } 1611 1612 count_event(trans->c, trans_restart_too_many_iters); 1613 1614 return btree_trans_restart(trans, BCH_ERR_transaction_restart_too_many_iters); 1615 } 1616 1617 static noinline void btree_path_overflow(struct btree_trans *trans) 1618 { 1619 bch2_dump_trans_paths_updates(trans); 1620 bch_err(trans->c, "trans path overflow"); 1621 } 1622 1623 static noinline void btree_paths_realloc(struct btree_trans *trans) 1624 { 1625 unsigned nr = trans->nr_paths * 2; 1626 1627 void *p = kvzalloc(BITS_TO_LONGS(nr) * sizeof(unsigned long) + 1628 sizeof(struct btree_trans_paths) + 1629 nr * sizeof(struct btree_path) + 1630 nr * sizeof(btree_path_idx_t) + 8 + 1631 nr * sizeof(struct btree_insert_entry), GFP_KERNEL|__GFP_NOFAIL); 1632 1633 unsigned long *paths_allocated = p; 1634 memcpy(paths_allocated, trans->paths_allocated, BITS_TO_LONGS(trans->nr_paths) * sizeof(unsigned long)); 1635 p += BITS_TO_LONGS(nr) * sizeof(unsigned long); 1636 1637 p += sizeof(struct btree_trans_paths); 1638 struct btree_path *paths = p; 1639 *trans_paths_nr(paths) = nr; 1640 memcpy(paths, trans->paths, trans->nr_paths * sizeof(struct btree_path)); 1641 p += nr * sizeof(struct btree_path); 1642 1643 btree_path_idx_t *sorted = p; 1644 memcpy(sorted, trans->sorted, trans->nr_sorted * sizeof(btree_path_idx_t)); 1645 p += nr * sizeof(btree_path_idx_t) + 8; 1646 1647 struct btree_insert_entry *updates = p; 1648 memcpy(updates, trans->updates, trans->nr_paths * sizeof(struct btree_insert_entry)); 1649 1650 unsigned long *old = trans->paths_allocated; 1651 1652 rcu_assign_pointer(trans->paths_allocated, paths_allocated); 1653 rcu_assign_pointer(trans->paths, paths); 1654 rcu_assign_pointer(trans->sorted, sorted); 1655 rcu_assign_pointer(trans->updates, updates); 1656 1657 trans->nr_paths = nr; 1658 1659 if (old != trans->_paths_allocated) 1660 kfree_rcu_mightsleep(old); 1661 } 1662 1663 static inline btree_path_idx_t btree_path_alloc(struct btree_trans *trans, 1664 btree_path_idx_t pos) 1665 { 1666 btree_path_idx_t idx = find_first_zero_bit(trans->paths_allocated, trans->nr_paths); 1667 1668 if (unlikely(idx == trans->nr_paths)) { 1669 if (trans->nr_paths == BTREE_ITER_MAX) { 1670 btree_path_overflow(trans); 1671 return 0; 1672 } 1673 1674 btree_paths_realloc(trans); 1675 } 1676 1677 /* 1678 * Do this before marking the new path as allocated, since it won't be 1679 * initialized yet: 1680 */ 1681 if (unlikely(idx > trans->nr_paths_max)) 1682 bch2_trans_update_max_paths(trans); 1683 1684 __set_bit(idx, trans->paths_allocated); 1685 1686 struct btree_path *path = &trans->paths[idx]; 1687 path->ref = 0; 1688 path->intent_ref = 0; 1689 path->nodes_locked = 0; 1690 1691 btree_path_list_add(trans, pos, idx); 1692 trans->paths_sorted = false; 1693 return idx; 1694 } 1695 1696 btree_path_idx_t bch2_path_get(struct btree_trans *trans, 1697 enum btree_id btree_id, struct bpos pos, 1698 unsigned locks_want, unsigned level, 1699 unsigned flags, unsigned long ip) 1700 { 1701 struct btree_path *path; 1702 bool cached = flags & BTREE_ITER_cached; 1703 bool intent = flags & BTREE_ITER_intent; 1704 struct trans_for_each_path_inorder_iter iter; 1705 btree_path_idx_t path_pos = 0, path_idx; 1706 1707 bch2_trans_verify_not_unlocked(trans); 1708 bch2_trans_verify_not_in_restart(trans); 1709 bch2_trans_verify_locks(trans); 1710 1711 btree_trans_sort_paths(trans); 1712 1713 trans_for_each_path_inorder(trans, path, iter) { 1714 if (__btree_path_cmp(path, 1715 btree_id, 1716 cached, 1717 pos, 1718 level) > 0) 1719 break; 1720 1721 path_pos = iter.path_idx; 1722 } 1723 1724 if (path_pos && 1725 trans->paths[path_pos].cached == cached && 1726 trans->paths[path_pos].btree_id == btree_id && 1727 trans->paths[path_pos].level == level) { 1728 trace_btree_path_get(trans, trans->paths + path_pos, &pos); 1729 1730 __btree_path_get(trans, trans->paths + path_pos, intent); 1731 path_idx = bch2_btree_path_set_pos(trans, path_pos, pos, intent, ip); 1732 path = trans->paths + path_idx; 1733 } else { 1734 path_idx = btree_path_alloc(trans, path_pos); 1735 path = trans->paths + path_idx; 1736 1737 __btree_path_get(trans, path, intent); 1738 path->pos = pos; 1739 path->btree_id = btree_id; 1740 path->cached = cached; 1741 path->uptodate = BTREE_ITER_NEED_TRAVERSE; 1742 path->should_be_locked = false; 1743 path->level = level; 1744 path->locks_want = locks_want; 1745 path->nodes_locked = 0; 1746 for (unsigned i = 0; i < ARRAY_SIZE(path->l); i++) 1747 path->l[i].b = ERR_PTR(-BCH_ERR_no_btree_node_init); 1748 #ifdef TRACK_PATH_ALLOCATED 1749 path->ip_allocated = ip; 1750 #endif 1751 trans->paths_sorted = false; 1752 1753 trace_btree_path_alloc(trans, path); 1754 } 1755 1756 if (!(flags & BTREE_ITER_nopreserve)) 1757 path->preserve = true; 1758 1759 if (path->intent_ref) 1760 locks_want = max(locks_want, level + 1); 1761 1762 /* 1763 * If the path has locks_want greater than requested, we don't downgrade 1764 * it here - on transaction restart because btree node split needs to 1765 * upgrade locks, we might be putting/getting the iterator again. 1766 * Downgrading iterators only happens via bch2_trans_downgrade(), after 1767 * a successful transaction commit. 1768 */ 1769 1770 locks_want = min(locks_want, BTREE_MAX_DEPTH); 1771 if (locks_want > path->locks_want) 1772 bch2_btree_path_upgrade_noupgrade_sibs(trans, path, locks_want, NULL); 1773 1774 return path_idx; 1775 } 1776 1777 btree_path_idx_t bch2_path_get_unlocked_mut(struct btree_trans *trans, 1778 enum btree_id btree_id, 1779 unsigned level, 1780 struct bpos pos) 1781 { 1782 btree_path_idx_t path_idx = bch2_path_get(trans, btree_id, pos, level + 1, level, 1783 BTREE_ITER_nopreserve| 1784 BTREE_ITER_intent, _RET_IP_); 1785 path_idx = bch2_btree_path_make_mut(trans, path_idx, true, _RET_IP_); 1786 1787 struct btree_path *path = trans->paths + path_idx; 1788 bch2_btree_path_downgrade(trans, path); 1789 __bch2_btree_path_unlock(trans, path); 1790 return path_idx; 1791 } 1792 1793 struct bkey_s_c bch2_btree_path_peek_slot(struct btree_path *path, struct bkey *u) 1794 { 1795 1796 struct btree_path_level *l = path_l(path); 1797 struct bkey_packed *_k; 1798 struct bkey_s_c k; 1799 1800 if (unlikely(!l->b)) 1801 return bkey_s_c_null; 1802 1803 EBUG_ON(path->uptodate != BTREE_ITER_UPTODATE); 1804 EBUG_ON(!btree_node_locked(path, path->level)); 1805 1806 if (!path->cached) { 1807 _k = bch2_btree_node_iter_peek_all(&l->iter, l->b); 1808 k = _k ? bkey_disassemble(l->b, _k, u) : bkey_s_c_null; 1809 1810 EBUG_ON(k.k && bkey_deleted(k.k) && bpos_eq(k.k->p, path->pos)); 1811 1812 if (!k.k || !bpos_eq(path->pos, k.k->p)) 1813 goto hole; 1814 } else { 1815 struct bkey_cached *ck = (void *) path->l[0].b; 1816 if (!ck) 1817 return bkey_s_c_null; 1818 1819 EBUG_ON(path->btree_id != ck->key.btree_id || 1820 !bkey_eq(path->pos, ck->key.pos)); 1821 1822 *u = ck->k->k; 1823 k = bkey_i_to_s_c(ck->k); 1824 } 1825 1826 return k; 1827 hole: 1828 bkey_init(u); 1829 u->p = path->pos; 1830 return (struct bkey_s_c) { u, NULL }; 1831 } 1832 1833 1834 void bch2_set_btree_iter_dontneed(struct btree_iter *iter) 1835 { 1836 struct btree_trans *trans = iter->trans; 1837 1838 if (!iter->path || trans->restarted) 1839 return; 1840 1841 struct btree_path *path = btree_iter_path(trans, iter); 1842 path->preserve = false; 1843 if (path->ref == 1) 1844 path->should_be_locked = false; 1845 } 1846 /* Btree iterators: */ 1847 1848 int __must_check 1849 __bch2_btree_iter_traverse(struct btree_iter *iter) 1850 { 1851 return bch2_btree_path_traverse(iter->trans, iter->path, iter->flags); 1852 } 1853 1854 int __must_check 1855 bch2_btree_iter_traverse(struct btree_iter *iter) 1856 { 1857 struct btree_trans *trans = iter->trans; 1858 int ret; 1859 1860 bch2_trans_verify_not_unlocked(trans); 1861 1862 iter->path = bch2_btree_path_set_pos(trans, iter->path, 1863 btree_iter_search_key(iter), 1864 iter->flags & BTREE_ITER_intent, 1865 btree_iter_ip_allocated(iter)); 1866 1867 ret = bch2_btree_path_traverse(iter->trans, iter->path, iter->flags); 1868 if (ret) 1869 return ret; 1870 1871 struct btree_path *path = btree_iter_path(trans, iter); 1872 if (btree_path_node(path, path->level)) 1873 btree_path_set_should_be_locked(trans, path); 1874 return 0; 1875 } 1876 1877 /* Iterate across nodes (leaf and interior nodes) */ 1878 1879 struct btree *bch2_btree_iter_peek_node(struct btree_iter *iter) 1880 { 1881 struct btree_trans *trans = iter->trans; 1882 struct btree *b = NULL; 1883 int ret; 1884 1885 EBUG_ON(trans->paths[iter->path].cached); 1886 bch2_btree_iter_verify(iter); 1887 1888 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags); 1889 if (ret) 1890 goto err; 1891 1892 struct btree_path *path = btree_iter_path(trans, iter); 1893 b = btree_path_node(path, path->level); 1894 if (!b) 1895 goto out; 1896 1897 BUG_ON(bpos_lt(b->key.k.p, iter->pos)); 1898 1899 bkey_init(&iter->k); 1900 iter->k.p = iter->pos = b->key.k.p; 1901 1902 iter->path = bch2_btree_path_set_pos(trans, iter->path, b->key.k.p, 1903 iter->flags & BTREE_ITER_intent, 1904 btree_iter_ip_allocated(iter)); 1905 btree_path_set_should_be_locked(trans, btree_iter_path(trans, iter)); 1906 out: 1907 bch2_btree_iter_verify_entry_exit(iter); 1908 bch2_btree_iter_verify(iter); 1909 1910 return b; 1911 err: 1912 b = ERR_PTR(ret); 1913 goto out; 1914 } 1915 1916 /* Only kept for -tools */ 1917 struct btree *bch2_btree_iter_peek_node_and_restart(struct btree_iter *iter) 1918 { 1919 struct btree *b; 1920 1921 while (b = bch2_btree_iter_peek_node(iter), 1922 bch2_err_matches(PTR_ERR_OR_ZERO(b), BCH_ERR_transaction_restart)) 1923 bch2_trans_begin(iter->trans); 1924 1925 return b; 1926 } 1927 1928 struct btree *bch2_btree_iter_next_node(struct btree_iter *iter) 1929 { 1930 struct btree_trans *trans = iter->trans; 1931 struct btree *b = NULL; 1932 int ret; 1933 1934 EBUG_ON(trans->paths[iter->path].cached); 1935 bch2_trans_verify_not_in_restart(trans); 1936 bch2_btree_iter_verify(iter); 1937 1938 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags); 1939 if (ret) 1940 goto err; 1941 1942 1943 struct btree_path *path = btree_iter_path(trans, iter); 1944 1945 /* already at end? */ 1946 if (!btree_path_node(path, path->level)) 1947 return NULL; 1948 1949 /* got to end? */ 1950 if (!btree_path_node(path, path->level + 1)) { 1951 btree_path_set_level_up(trans, path); 1952 return NULL; 1953 } 1954 1955 if (!bch2_btree_node_relock(trans, path, path->level + 1)) { 1956 __bch2_btree_path_unlock(trans, path); 1957 path->l[path->level].b = ERR_PTR(-BCH_ERR_no_btree_node_relock); 1958 path->l[path->level + 1].b = ERR_PTR(-BCH_ERR_no_btree_node_relock); 1959 btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE); 1960 trace_and_count(trans->c, trans_restart_relock_next_node, trans, _THIS_IP_, path); 1961 ret = btree_trans_restart(trans, BCH_ERR_transaction_restart_relock); 1962 goto err; 1963 } 1964 1965 b = btree_path_node(path, path->level + 1); 1966 1967 if (bpos_eq(iter->pos, b->key.k.p)) { 1968 __btree_path_set_level_up(trans, path, path->level++); 1969 } else { 1970 if (btree_lock_want(path, path->level + 1) == BTREE_NODE_UNLOCKED) 1971 btree_node_unlock(trans, path, path->level + 1); 1972 1973 /* 1974 * Haven't gotten to the end of the parent node: go back down to 1975 * the next child node 1976 */ 1977 iter->path = bch2_btree_path_set_pos(trans, iter->path, 1978 bpos_successor(iter->pos), 1979 iter->flags & BTREE_ITER_intent, 1980 btree_iter_ip_allocated(iter)); 1981 1982 path = btree_iter_path(trans, iter); 1983 btree_path_set_level_down(trans, path, iter->min_depth); 1984 1985 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags); 1986 if (ret) 1987 goto err; 1988 1989 path = btree_iter_path(trans, iter); 1990 b = path->l[path->level].b; 1991 } 1992 1993 bkey_init(&iter->k); 1994 iter->k.p = iter->pos = b->key.k.p; 1995 1996 iter->path = bch2_btree_path_set_pos(trans, iter->path, b->key.k.p, 1997 iter->flags & BTREE_ITER_intent, 1998 btree_iter_ip_allocated(iter)); 1999 btree_path_set_should_be_locked(trans, btree_iter_path(trans, iter)); 2000 EBUG_ON(btree_iter_path(trans, iter)->uptodate); 2001 out: 2002 bch2_btree_iter_verify_entry_exit(iter); 2003 bch2_btree_iter_verify(iter); 2004 2005 return b; 2006 err: 2007 b = ERR_PTR(ret); 2008 goto out; 2009 } 2010 2011 /* Iterate across keys (in leaf nodes only) */ 2012 2013 inline bool bch2_btree_iter_advance(struct btree_iter *iter) 2014 { 2015 struct bpos pos = iter->k.p; 2016 bool ret = !(iter->flags & BTREE_ITER_all_snapshots 2017 ? bpos_eq(pos, SPOS_MAX) 2018 : bkey_eq(pos, SPOS_MAX)); 2019 2020 if (ret && !(iter->flags & BTREE_ITER_is_extents)) 2021 pos = bkey_successor(iter, pos); 2022 bch2_btree_iter_set_pos(iter, pos); 2023 return ret; 2024 } 2025 2026 inline bool bch2_btree_iter_rewind(struct btree_iter *iter) 2027 { 2028 struct bpos pos = bkey_start_pos(&iter->k); 2029 bool ret = !(iter->flags & BTREE_ITER_all_snapshots 2030 ? bpos_eq(pos, POS_MIN) 2031 : bkey_eq(pos, POS_MIN)); 2032 2033 if (ret && !(iter->flags & BTREE_ITER_is_extents)) 2034 pos = bkey_predecessor(iter, pos); 2035 bch2_btree_iter_set_pos(iter, pos); 2036 return ret; 2037 } 2038 2039 static noinline 2040 void bch2_btree_trans_peek_prev_updates(struct btree_trans *trans, struct btree_iter *iter, 2041 struct bkey_s_c *k) 2042 { 2043 struct bpos end = path_l(btree_iter_path(trans, iter))->b->data->min_key; 2044 2045 trans_for_each_update(trans, i) 2046 if (!i->key_cache_already_flushed && 2047 i->btree_id == iter->btree_id && 2048 bpos_le(i->k->k.p, iter->pos) && 2049 bpos_ge(i->k->k.p, k->k ? k->k->p : end)) { 2050 iter->k = i->k->k; 2051 *k = bkey_i_to_s_c(i->k); 2052 } 2053 } 2054 2055 static noinline 2056 void bch2_btree_trans_peek_updates(struct btree_trans *trans, struct btree_iter *iter, 2057 struct bkey_s_c *k) 2058 { 2059 struct btree_path *path = btree_iter_path(trans, iter); 2060 struct bpos end = path_l(path)->b->key.k.p; 2061 2062 trans_for_each_update(trans, i) 2063 if (!i->key_cache_already_flushed && 2064 i->btree_id == iter->btree_id && 2065 bpos_ge(i->k->k.p, path->pos) && 2066 bpos_le(i->k->k.p, k->k ? k->k->p : end)) { 2067 iter->k = i->k->k; 2068 *k = bkey_i_to_s_c(i->k); 2069 } 2070 } 2071 2072 static noinline 2073 void bch2_btree_trans_peek_slot_updates(struct btree_trans *trans, struct btree_iter *iter, 2074 struct bkey_s_c *k) 2075 { 2076 trans_for_each_update(trans, i) 2077 if (!i->key_cache_already_flushed && 2078 i->btree_id == iter->btree_id && 2079 bpos_eq(i->k->k.p, iter->pos)) { 2080 iter->k = i->k->k; 2081 *k = bkey_i_to_s_c(i->k); 2082 } 2083 } 2084 2085 static struct bkey_i *bch2_btree_journal_peek(struct btree_trans *trans, 2086 struct btree_iter *iter, 2087 struct bpos end_pos) 2088 { 2089 struct btree_path *path = btree_iter_path(trans, iter); 2090 2091 return bch2_journal_keys_peek_upto(trans->c, iter->btree_id, 2092 path->level, 2093 path->pos, 2094 end_pos, 2095 &iter->journal_idx); 2096 } 2097 2098 static noinline 2099 struct bkey_s_c btree_trans_peek_slot_journal(struct btree_trans *trans, 2100 struct btree_iter *iter) 2101 { 2102 struct btree_path *path = btree_iter_path(trans, iter); 2103 struct bkey_i *k = bch2_btree_journal_peek(trans, iter, path->pos); 2104 2105 if (k) { 2106 iter->k = k->k; 2107 return bkey_i_to_s_c(k); 2108 } else { 2109 return bkey_s_c_null; 2110 } 2111 } 2112 2113 static noinline 2114 struct bkey_s_c btree_trans_peek_journal(struct btree_trans *trans, 2115 struct btree_iter *iter, 2116 struct bkey_s_c k) 2117 { 2118 struct btree_path *path = btree_iter_path(trans, iter); 2119 struct bkey_i *next_journal = 2120 bch2_btree_journal_peek(trans, iter, 2121 k.k ? k.k->p : path_l(path)->b->key.k.p); 2122 2123 if (next_journal) { 2124 iter->k = next_journal->k; 2125 k = bkey_i_to_s_c(next_journal); 2126 } 2127 2128 return k; 2129 } 2130 2131 /* 2132 * Checks btree key cache for key at iter->pos and returns it if present, or 2133 * bkey_s_c_null: 2134 */ 2135 static noinline 2136 struct bkey_s_c btree_trans_peek_key_cache(struct btree_iter *iter, struct bpos pos) 2137 { 2138 struct btree_trans *trans = iter->trans; 2139 struct bch_fs *c = trans->c; 2140 struct bkey u; 2141 struct bkey_s_c k; 2142 int ret; 2143 2144 bch2_trans_verify_not_in_restart(trans); 2145 bch2_trans_verify_not_unlocked(trans); 2146 2147 if ((iter->flags & BTREE_ITER_key_cache_fill) && 2148 bpos_eq(iter->pos, pos)) 2149 return bkey_s_c_null; 2150 2151 if (!bch2_btree_key_cache_find(c, iter->btree_id, pos)) 2152 return bkey_s_c_null; 2153 2154 if (!iter->key_cache_path) 2155 iter->key_cache_path = bch2_path_get(trans, iter->btree_id, pos, 2156 iter->flags & BTREE_ITER_intent, 0, 2157 iter->flags|BTREE_ITER_cached| 2158 BTREE_ITER_cached_nofill, 2159 _THIS_IP_); 2160 2161 iter->key_cache_path = bch2_btree_path_set_pos(trans, iter->key_cache_path, pos, 2162 iter->flags & BTREE_ITER_intent, 2163 btree_iter_ip_allocated(iter)); 2164 2165 ret = bch2_btree_path_traverse(trans, iter->key_cache_path, 2166 iter->flags|BTREE_ITER_cached) ?: 2167 bch2_btree_path_relock(trans, btree_iter_path(trans, iter), _THIS_IP_); 2168 if (unlikely(ret)) 2169 return bkey_s_c_err(ret); 2170 2171 btree_path_set_should_be_locked(trans, trans->paths + iter->key_cache_path); 2172 2173 k = bch2_btree_path_peek_slot(trans->paths + iter->key_cache_path, &u); 2174 if (k.k && !bkey_err(k)) { 2175 iter->k = u; 2176 k.k = &iter->k; 2177 } 2178 return k; 2179 } 2180 2181 static struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter, struct bpos search_key) 2182 { 2183 struct btree_trans *trans = iter->trans; 2184 struct bkey_s_c k, k2; 2185 int ret; 2186 2187 EBUG_ON(btree_iter_path(trans, iter)->cached); 2188 bch2_btree_iter_verify(iter); 2189 2190 while (1) { 2191 struct btree_path_level *l; 2192 2193 iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key, 2194 iter->flags & BTREE_ITER_intent, 2195 btree_iter_ip_allocated(iter)); 2196 2197 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags); 2198 if (unlikely(ret)) { 2199 /* ensure that iter->k is consistent with iter->pos: */ 2200 bch2_btree_iter_set_pos(iter, iter->pos); 2201 k = bkey_s_c_err(ret); 2202 goto out; 2203 } 2204 2205 struct btree_path *path = btree_iter_path(trans, iter); 2206 l = path_l(path); 2207 2208 if (unlikely(!l->b)) { 2209 /* No btree nodes at requested level: */ 2210 bch2_btree_iter_set_pos(iter, SPOS_MAX); 2211 k = bkey_s_c_null; 2212 goto out; 2213 } 2214 2215 btree_path_set_should_be_locked(trans, path); 2216 2217 k = btree_path_level_peek_all(trans->c, l, &iter->k); 2218 2219 if (unlikely(iter->flags & BTREE_ITER_with_key_cache) && 2220 k.k && 2221 (k2 = btree_trans_peek_key_cache(iter, k.k->p)).k) { 2222 k = k2; 2223 ret = bkey_err(k); 2224 if (ret) { 2225 bch2_btree_iter_set_pos(iter, iter->pos); 2226 goto out; 2227 } 2228 } 2229 2230 if (unlikely(iter->flags & BTREE_ITER_with_journal)) 2231 k = btree_trans_peek_journal(trans, iter, k); 2232 2233 if (unlikely((iter->flags & BTREE_ITER_with_updates) && 2234 trans->nr_updates)) 2235 bch2_btree_trans_peek_updates(trans, iter, &k); 2236 2237 if (k.k && bkey_deleted(k.k)) { 2238 /* 2239 * If we've got a whiteout, and it's after the search 2240 * key, advance the search key to the whiteout instead 2241 * of just after the whiteout - it might be a btree 2242 * whiteout, with a real key at the same position, since 2243 * in the btree deleted keys sort before non deleted. 2244 */ 2245 search_key = !bpos_eq(search_key, k.k->p) 2246 ? k.k->p 2247 : bpos_successor(k.k->p); 2248 continue; 2249 } 2250 2251 if (likely(k.k)) { 2252 break; 2253 } else if (likely(!bpos_eq(l->b->key.k.p, SPOS_MAX))) { 2254 /* Advance to next leaf node: */ 2255 search_key = bpos_successor(l->b->key.k.p); 2256 } else { 2257 /* End of btree: */ 2258 bch2_btree_iter_set_pos(iter, SPOS_MAX); 2259 k = bkey_s_c_null; 2260 goto out; 2261 } 2262 } 2263 out: 2264 bch2_btree_iter_verify(iter); 2265 2266 return k; 2267 } 2268 2269 /** 2270 * bch2_btree_iter_peek_upto() - returns first key greater than or equal to 2271 * iterator's current position 2272 * @iter: iterator to peek from 2273 * @end: search limit: returns keys less than or equal to @end 2274 * 2275 * Returns: key if found, or an error extractable with bkey_err(). 2276 */ 2277 struct bkey_s_c bch2_btree_iter_peek_upto(struct btree_iter *iter, struct bpos end) 2278 { 2279 struct btree_trans *trans = iter->trans; 2280 struct bpos search_key = btree_iter_search_key(iter); 2281 struct bkey_s_c k; 2282 struct bpos iter_pos; 2283 int ret; 2284 2285 bch2_trans_verify_not_unlocked(trans); 2286 EBUG_ON((iter->flags & BTREE_ITER_filter_snapshots) && bkey_eq(end, POS_MAX)); 2287 2288 if (iter->update_path) { 2289 bch2_path_put_nokeep(trans, iter->update_path, 2290 iter->flags & BTREE_ITER_intent); 2291 iter->update_path = 0; 2292 } 2293 2294 bch2_btree_iter_verify_entry_exit(iter); 2295 2296 while (1) { 2297 k = __bch2_btree_iter_peek(iter, search_key); 2298 if (unlikely(!k.k)) 2299 goto end; 2300 if (unlikely(bkey_err(k))) 2301 goto out_no_locked; 2302 2303 /* 2304 * We need to check against @end before FILTER_SNAPSHOTS because 2305 * if we get to a different inode that requested we might be 2306 * seeing keys for a different snapshot tree that will all be 2307 * filtered out. 2308 * 2309 * But we can't do the full check here, because bkey_start_pos() 2310 * isn't monotonically increasing before FILTER_SNAPSHOTS, and 2311 * that's what we check against in extents mode: 2312 */ 2313 if (unlikely(!(iter->flags & BTREE_ITER_is_extents) 2314 ? bkey_gt(k.k->p, end) 2315 : k.k->p.inode > end.inode)) 2316 goto end; 2317 2318 if (iter->update_path && 2319 !bkey_eq(trans->paths[iter->update_path].pos, k.k->p)) { 2320 bch2_path_put_nokeep(trans, iter->update_path, 2321 iter->flags & BTREE_ITER_intent); 2322 iter->update_path = 0; 2323 } 2324 2325 if ((iter->flags & BTREE_ITER_filter_snapshots) && 2326 (iter->flags & BTREE_ITER_intent) && 2327 !(iter->flags & BTREE_ITER_is_extents) && 2328 !iter->update_path) { 2329 struct bpos pos = k.k->p; 2330 2331 if (pos.snapshot < iter->snapshot) { 2332 search_key = bpos_successor(k.k->p); 2333 continue; 2334 } 2335 2336 pos.snapshot = iter->snapshot; 2337 2338 /* 2339 * advance, same as on exit for iter->path, but only up 2340 * to snapshot 2341 */ 2342 __btree_path_get(trans, trans->paths + iter->path, iter->flags & BTREE_ITER_intent); 2343 iter->update_path = iter->path; 2344 2345 iter->update_path = bch2_btree_path_set_pos(trans, 2346 iter->update_path, pos, 2347 iter->flags & BTREE_ITER_intent, 2348 _THIS_IP_); 2349 ret = bch2_btree_path_traverse(trans, iter->update_path, iter->flags); 2350 if (unlikely(ret)) { 2351 k = bkey_s_c_err(ret); 2352 goto out_no_locked; 2353 } 2354 } 2355 2356 /* 2357 * We can never have a key in a leaf node at POS_MAX, so 2358 * we don't have to check these successor() calls: 2359 */ 2360 if ((iter->flags & BTREE_ITER_filter_snapshots) && 2361 !bch2_snapshot_is_ancestor(trans->c, 2362 iter->snapshot, 2363 k.k->p.snapshot)) { 2364 search_key = bpos_successor(k.k->p); 2365 continue; 2366 } 2367 2368 if (bkey_whiteout(k.k) && 2369 !(iter->flags & BTREE_ITER_all_snapshots)) { 2370 search_key = bkey_successor(iter, k.k->p); 2371 continue; 2372 } 2373 2374 /* 2375 * iter->pos should be mononotically increasing, and always be 2376 * equal to the key we just returned - except extents can 2377 * straddle iter->pos: 2378 */ 2379 if (!(iter->flags & BTREE_ITER_is_extents)) 2380 iter_pos = k.k->p; 2381 else 2382 iter_pos = bkey_max(iter->pos, bkey_start_pos(k.k)); 2383 2384 if (unlikely(iter->flags & BTREE_ITER_all_snapshots ? bpos_gt(iter_pos, end) : 2385 iter->flags & BTREE_ITER_is_extents ? bkey_ge(iter_pos, end) : 2386 bkey_gt(iter_pos, end))) 2387 goto end; 2388 2389 break; 2390 } 2391 2392 iter->pos = iter_pos; 2393 2394 iter->path = bch2_btree_path_set_pos(trans, iter->path, k.k->p, 2395 iter->flags & BTREE_ITER_intent, 2396 btree_iter_ip_allocated(iter)); 2397 2398 btree_path_set_should_be_locked(trans, btree_iter_path(trans, iter)); 2399 out_no_locked: 2400 if (iter->update_path) { 2401 ret = bch2_btree_path_relock(trans, trans->paths + iter->update_path, _THIS_IP_); 2402 if (unlikely(ret)) 2403 k = bkey_s_c_err(ret); 2404 else 2405 btree_path_set_should_be_locked(trans, trans->paths + iter->update_path); 2406 } 2407 2408 if (!(iter->flags & BTREE_ITER_all_snapshots)) 2409 iter->pos.snapshot = iter->snapshot; 2410 2411 ret = bch2_btree_iter_verify_ret(iter, k); 2412 if (unlikely(ret)) { 2413 bch2_btree_iter_set_pos(iter, iter->pos); 2414 k = bkey_s_c_err(ret); 2415 } 2416 2417 bch2_btree_iter_verify_entry_exit(iter); 2418 2419 return k; 2420 end: 2421 bch2_btree_iter_set_pos(iter, end); 2422 k = bkey_s_c_null; 2423 goto out_no_locked; 2424 } 2425 2426 /** 2427 * bch2_btree_iter_next() - returns first key greater than iterator's current 2428 * position 2429 * @iter: iterator to peek from 2430 * 2431 * Returns: key if found, or an error extractable with bkey_err(). 2432 */ 2433 struct bkey_s_c bch2_btree_iter_next(struct btree_iter *iter) 2434 { 2435 if (!bch2_btree_iter_advance(iter)) 2436 return bkey_s_c_null; 2437 2438 return bch2_btree_iter_peek(iter); 2439 } 2440 2441 /** 2442 * bch2_btree_iter_peek_prev() - returns first key less than or equal to 2443 * iterator's current position 2444 * @iter: iterator to peek from 2445 * 2446 * Returns: key if found, or an error extractable with bkey_err(). 2447 */ 2448 struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *iter) 2449 { 2450 struct btree_trans *trans = iter->trans; 2451 struct bpos search_key = iter->pos; 2452 struct bkey_s_c k; 2453 struct bkey saved_k; 2454 const struct bch_val *saved_v; 2455 btree_path_idx_t saved_path = 0; 2456 int ret; 2457 2458 bch2_trans_verify_not_unlocked(trans); 2459 EBUG_ON(btree_iter_path(trans, iter)->cached || 2460 btree_iter_path(trans, iter)->level); 2461 2462 if (iter->flags & BTREE_ITER_with_journal) 2463 return bkey_s_c_err(-BCH_ERR_btree_iter_with_journal_not_supported); 2464 2465 bch2_btree_iter_verify(iter); 2466 bch2_btree_iter_verify_entry_exit(iter); 2467 2468 if (iter->flags & BTREE_ITER_filter_snapshots) 2469 search_key.snapshot = U32_MAX; 2470 2471 while (1) { 2472 iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key, 2473 iter->flags & BTREE_ITER_intent, 2474 btree_iter_ip_allocated(iter)); 2475 2476 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags); 2477 if (unlikely(ret)) { 2478 /* ensure that iter->k is consistent with iter->pos: */ 2479 bch2_btree_iter_set_pos(iter, iter->pos); 2480 k = bkey_s_c_err(ret); 2481 goto out_no_locked; 2482 } 2483 2484 struct btree_path *path = btree_iter_path(trans, iter); 2485 2486 k = btree_path_level_peek(trans, path, &path->l[0], &iter->k); 2487 if (!k.k || 2488 ((iter->flags & BTREE_ITER_is_extents) 2489 ? bpos_ge(bkey_start_pos(k.k), search_key) 2490 : bpos_gt(k.k->p, search_key))) 2491 k = btree_path_level_prev(trans, path, &path->l[0], &iter->k); 2492 2493 if (unlikely((iter->flags & BTREE_ITER_with_updates) && 2494 trans->nr_updates)) 2495 bch2_btree_trans_peek_prev_updates(trans, iter, &k); 2496 2497 if (likely(k.k)) { 2498 if (iter->flags & BTREE_ITER_filter_snapshots) { 2499 if (k.k->p.snapshot == iter->snapshot) 2500 goto got_key; 2501 2502 /* 2503 * If we have a saved candidate, and we're no 2504 * longer at the same _key_ (not pos), return 2505 * that candidate 2506 */ 2507 if (saved_path && !bkey_eq(k.k->p, saved_k.p)) { 2508 bch2_path_put_nokeep(trans, iter->path, 2509 iter->flags & BTREE_ITER_intent); 2510 iter->path = saved_path; 2511 saved_path = 0; 2512 iter->k = saved_k; 2513 k.v = saved_v; 2514 goto got_key; 2515 } 2516 2517 if (bch2_snapshot_is_ancestor(trans->c, 2518 iter->snapshot, 2519 k.k->p.snapshot)) { 2520 if (saved_path) 2521 bch2_path_put_nokeep(trans, saved_path, 2522 iter->flags & BTREE_ITER_intent); 2523 saved_path = btree_path_clone(trans, iter->path, 2524 iter->flags & BTREE_ITER_intent, 2525 _THIS_IP_); 2526 path = btree_iter_path(trans, iter); 2527 trace_btree_path_save_pos(trans, path, trans->paths + saved_path); 2528 saved_k = *k.k; 2529 saved_v = k.v; 2530 } 2531 2532 search_key = bpos_predecessor(k.k->p); 2533 continue; 2534 } 2535 got_key: 2536 if (bkey_whiteout(k.k) && 2537 !(iter->flags & BTREE_ITER_all_snapshots)) { 2538 search_key = bkey_predecessor(iter, k.k->p); 2539 if (iter->flags & BTREE_ITER_filter_snapshots) 2540 search_key.snapshot = U32_MAX; 2541 continue; 2542 } 2543 2544 btree_path_set_should_be_locked(trans, path); 2545 break; 2546 } else if (likely(!bpos_eq(path->l[0].b->data->min_key, POS_MIN))) { 2547 /* Advance to previous leaf node: */ 2548 search_key = bpos_predecessor(path->l[0].b->data->min_key); 2549 } else { 2550 /* Start of btree: */ 2551 bch2_btree_iter_set_pos(iter, POS_MIN); 2552 k = bkey_s_c_null; 2553 goto out_no_locked; 2554 } 2555 } 2556 2557 EBUG_ON(bkey_gt(bkey_start_pos(k.k), iter->pos)); 2558 2559 /* Extents can straddle iter->pos: */ 2560 if (bkey_lt(k.k->p, iter->pos)) 2561 iter->pos = k.k->p; 2562 2563 if (iter->flags & BTREE_ITER_filter_snapshots) 2564 iter->pos.snapshot = iter->snapshot; 2565 out_no_locked: 2566 if (saved_path) 2567 bch2_path_put_nokeep(trans, saved_path, iter->flags & BTREE_ITER_intent); 2568 2569 bch2_btree_iter_verify_entry_exit(iter); 2570 bch2_btree_iter_verify(iter); 2571 2572 return k; 2573 } 2574 2575 /** 2576 * bch2_btree_iter_prev() - returns first key less than iterator's current 2577 * position 2578 * @iter: iterator to peek from 2579 * 2580 * Returns: key if found, or an error extractable with bkey_err(). 2581 */ 2582 struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *iter) 2583 { 2584 if (!bch2_btree_iter_rewind(iter)) 2585 return bkey_s_c_null; 2586 2587 return bch2_btree_iter_peek_prev(iter); 2588 } 2589 2590 struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *iter) 2591 { 2592 struct btree_trans *trans = iter->trans; 2593 struct bpos search_key; 2594 struct bkey_s_c k; 2595 int ret; 2596 2597 bch2_trans_verify_not_unlocked(trans); 2598 bch2_btree_iter_verify(iter); 2599 bch2_btree_iter_verify_entry_exit(iter); 2600 EBUG_ON(btree_iter_path(trans, iter)->level && (iter->flags & BTREE_ITER_with_key_cache)); 2601 2602 /* extents can't span inode numbers: */ 2603 if ((iter->flags & BTREE_ITER_is_extents) && 2604 unlikely(iter->pos.offset == KEY_OFFSET_MAX)) { 2605 if (iter->pos.inode == KEY_INODE_MAX) 2606 return bkey_s_c_null; 2607 2608 bch2_btree_iter_set_pos(iter, bpos_nosnap_successor(iter->pos)); 2609 } 2610 2611 search_key = btree_iter_search_key(iter); 2612 iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key, 2613 iter->flags & BTREE_ITER_intent, 2614 btree_iter_ip_allocated(iter)); 2615 2616 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags); 2617 if (unlikely(ret)) { 2618 k = bkey_s_c_err(ret); 2619 goto out_no_locked; 2620 } 2621 2622 if ((iter->flags & BTREE_ITER_cached) || 2623 !(iter->flags & (BTREE_ITER_is_extents|BTREE_ITER_filter_snapshots))) { 2624 k = bkey_s_c_null; 2625 2626 if (unlikely((iter->flags & BTREE_ITER_with_updates) && 2627 trans->nr_updates)) { 2628 bch2_btree_trans_peek_slot_updates(trans, iter, &k); 2629 if (k.k) 2630 goto out; 2631 } 2632 2633 if (unlikely(iter->flags & BTREE_ITER_with_journal) && 2634 (k = btree_trans_peek_slot_journal(trans, iter)).k) 2635 goto out; 2636 2637 if (unlikely(iter->flags & BTREE_ITER_with_key_cache) && 2638 (k = btree_trans_peek_key_cache(iter, iter->pos)).k) { 2639 if (!bkey_err(k)) 2640 iter->k = *k.k; 2641 /* We're not returning a key from iter->path: */ 2642 goto out_no_locked; 2643 } 2644 2645 k = bch2_btree_path_peek_slot(trans->paths + iter->path, &iter->k); 2646 if (unlikely(!k.k)) 2647 goto out_no_locked; 2648 } else { 2649 struct bpos next; 2650 struct bpos end = iter->pos; 2651 2652 if (iter->flags & BTREE_ITER_is_extents) 2653 end.offset = U64_MAX; 2654 2655 EBUG_ON(btree_iter_path(trans, iter)->level); 2656 2657 if (iter->flags & BTREE_ITER_intent) { 2658 struct btree_iter iter2; 2659 2660 bch2_trans_copy_iter(&iter2, iter); 2661 k = bch2_btree_iter_peek_upto(&iter2, end); 2662 2663 if (k.k && !bkey_err(k)) { 2664 swap(iter->key_cache_path, iter2.key_cache_path); 2665 iter->k = iter2.k; 2666 k.k = &iter->k; 2667 } 2668 bch2_trans_iter_exit(trans, &iter2); 2669 } else { 2670 struct bpos pos = iter->pos; 2671 2672 k = bch2_btree_iter_peek_upto(iter, end); 2673 if (unlikely(bkey_err(k))) 2674 bch2_btree_iter_set_pos(iter, pos); 2675 else 2676 iter->pos = pos; 2677 } 2678 2679 if (unlikely(bkey_err(k))) 2680 goto out_no_locked; 2681 2682 next = k.k ? bkey_start_pos(k.k) : POS_MAX; 2683 2684 if (bkey_lt(iter->pos, next)) { 2685 bkey_init(&iter->k); 2686 iter->k.p = iter->pos; 2687 2688 if (iter->flags & BTREE_ITER_is_extents) { 2689 bch2_key_resize(&iter->k, 2690 min_t(u64, KEY_SIZE_MAX, 2691 (next.inode == iter->pos.inode 2692 ? next.offset 2693 : KEY_OFFSET_MAX) - 2694 iter->pos.offset)); 2695 EBUG_ON(!iter->k.size); 2696 } 2697 2698 k = (struct bkey_s_c) { &iter->k, NULL }; 2699 } 2700 } 2701 out: 2702 btree_path_set_should_be_locked(trans, btree_iter_path(trans, iter)); 2703 out_no_locked: 2704 bch2_btree_iter_verify_entry_exit(iter); 2705 bch2_btree_iter_verify(iter); 2706 ret = bch2_btree_iter_verify_ret(iter, k); 2707 if (unlikely(ret)) 2708 return bkey_s_c_err(ret); 2709 2710 return k; 2711 } 2712 2713 struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *iter) 2714 { 2715 if (!bch2_btree_iter_advance(iter)) 2716 return bkey_s_c_null; 2717 2718 return bch2_btree_iter_peek_slot(iter); 2719 } 2720 2721 struct bkey_s_c bch2_btree_iter_prev_slot(struct btree_iter *iter) 2722 { 2723 if (!bch2_btree_iter_rewind(iter)) 2724 return bkey_s_c_null; 2725 2726 return bch2_btree_iter_peek_slot(iter); 2727 } 2728 2729 /* Obsolete, but still used by rust wrapper in -tools */ 2730 struct bkey_s_c bch2_btree_iter_peek_and_restart_outlined(struct btree_iter *iter) 2731 { 2732 struct bkey_s_c k; 2733 2734 while (btree_trans_too_many_iters(iter->trans) || 2735 (k = bch2_btree_iter_peek_type(iter, iter->flags), 2736 bch2_err_matches(bkey_err(k), BCH_ERR_transaction_restart))) 2737 bch2_trans_begin(iter->trans); 2738 2739 return k; 2740 } 2741 2742 /* new transactional stuff: */ 2743 2744 #ifdef CONFIG_BCACHEFS_DEBUG 2745 static void btree_trans_verify_sorted_refs(struct btree_trans *trans) 2746 { 2747 struct btree_path *path; 2748 unsigned i; 2749 2750 BUG_ON(trans->nr_sorted != bitmap_weight(trans->paths_allocated, trans->nr_paths) - 1); 2751 2752 trans_for_each_path(trans, path, i) { 2753 BUG_ON(path->sorted_idx >= trans->nr_sorted); 2754 BUG_ON(trans->sorted[path->sorted_idx] != i); 2755 } 2756 2757 for (i = 0; i < trans->nr_sorted; i++) { 2758 unsigned idx = trans->sorted[i]; 2759 2760 BUG_ON(!test_bit(idx, trans->paths_allocated)); 2761 BUG_ON(trans->paths[idx].sorted_idx != i); 2762 } 2763 } 2764 2765 static void btree_trans_verify_sorted(struct btree_trans *trans) 2766 { 2767 struct btree_path *path, *prev = NULL; 2768 struct trans_for_each_path_inorder_iter iter; 2769 2770 if (!bch2_debug_check_iterators) 2771 return; 2772 2773 trans_for_each_path_inorder(trans, path, iter) { 2774 if (prev && btree_path_cmp(prev, path) > 0) { 2775 __bch2_dump_trans_paths_updates(trans, true); 2776 panic("trans paths out of order!\n"); 2777 } 2778 prev = path; 2779 } 2780 } 2781 #else 2782 static inline void btree_trans_verify_sorted_refs(struct btree_trans *trans) {} 2783 static inline void btree_trans_verify_sorted(struct btree_trans *trans) {} 2784 #endif 2785 2786 void __bch2_btree_trans_sort_paths(struct btree_trans *trans) 2787 { 2788 int i, l = 0, r = trans->nr_sorted, inc = 1; 2789 bool swapped; 2790 2791 btree_trans_verify_sorted_refs(trans); 2792 2793 if (trans->paths_sorted) 2794 goto out; 2795 2796 /* 2797 * Cocktail shaker sort: this is efficient because iterators will be 2798 * mostly sorted. 2799 */ 2800 do { 2801 swapped = false; 2802 2803 for (i = inc > 0 ? l : r - 2; 2804 i + 1 < r && i >= l; 2805 i += inc) { 2806 if (btree_path_cmp(trans->paths + trans->sorted[i], 2807 trans->paths + trans->sorted[i + 1]) > 0) { 2808 swap(trans->sorted[i], trans->sorted[i + 1]); 2809 trans->paths[trans->sorted[i]].sorted_idx = i; 2810 trans->paths[trans->sorted[i + 1]].sorted_idx = i + 1; 2811 swapped = true; 2812 } 2813 } 2814 2815 if (inc > 0) 2816 --r; 2817 else 2818 l++; 2819 inc = -inc; 2820 } while (swapped); 2821 2822 trans->paths_sorted = true; 2823 out: 2824 btree_trans_verify_sorted(trans); 2825 } 2826 2827 static inline void btree_path_list_remove(struct btree_trans *trans, 2828 struct btree_path *path) 2829 { 2830 EBUG_ON(path->sorted_idx >= trans->nr_sorted); 2831 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 2832 trans->nr_sorted--; 2833 memmove_u64s_down_small(trans->sorted + path->sorted_idx, 2834 trans->sorted + path->sorted_idx + 1, 2835 DIV_ROUND_UP(trans->nr_sorted - path->sorted_idx, 2836 sizeof(u64) / sizeof(btree_path_idx_t))); 2837 #else 2838 array_remove_item(trans->sorted, trans->nr_sorted, path->sorted_idx); 2839 #endif 2840 for (unsigned i = path->sorted_idx; i < trans->nr_sorted; i++) 2841 trans->paths[trans->sorted[i]].sorted_idx = i; 2842 } 2843 2844 static inline void btree_path_list_add(struct btree_trans *trans, 2845 btree_path_idx_t pos, 2846 btree_path_idx_t path_idx) 2847 { 2848 struct btree_path *path = trans->paths + path_idx; 2849 2850 path->sorted_idx = pos ? trans->paths[pos].sorted_idx + 1 : trans->nr_sorted; 2851 2852 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 2853 memmove_u64s_up_small(trans->sorted + path->sorted_idx + 1, 2854 trans->sorted + path->sorted_idx, 2855 DIV_ROUND_UP(trans->nr_sorted - path->sorted_idx, 2856 sizeof(u64) / sizeof(btree_path_idx_t))); 2857 trans->nr_sorted++; 2858 trans->sorted[path->sorted_idx] = path_idx; 2859 #else 2860 array_insert_item(trans->sorted, trans->nr_sorted, path->sorted_idx, path_idx); 2861 #endif 2862 2863 for (unsigned i = path->sorted_idx; i < trans->nr_sorted; i++) 2864 trans->paths[trans->sorted[i]].sorted_idx = i; 2865 2866 btree_trans_verify_sorted_refs(trans); 2867 } 2868 2869 void bch2_trans_iter_exit(struct btree_trans *trans, struct btree_iter *iter) 2870 { 2871 if (iter->update_path) 2872 bch2_path_put_nokeep(trans, iter->update_path, 2873 iter->flags & BTREE_ITER_intent); 2874 if (iter->path) 2875 bch2_path_put(trans, iter->path, 2876 iter->flags & BTREE_ITER_intent); 2877 if (iter->key_cache_path) 2878 bch2_path_put(trans, iter->key_cache_path, 2879 iter->flags & BTREE_ITER_intent); 2880 iter->path = 0; 2881 iter->update_path = 0; 2882 iter->key_cache_path = 0; 2883 iter->trans = NULL; 2884 } 2885 2886 void bch2_trans_iter_init_outlined(struct btree_trans *trans, 2887 struct btree_iter *iter, 2888 enum btree_id btree_id, struct bpos pos, 2889 unsigned flags) 2890 { 2891 bch2_trans_iter_init_common(trans, iter, btree_id, pos, 0, 0, 2892 bch2_btree_iter_flags(trans, btree_id, flags), 2893 _RET_IP_); 2894 } 2895 2896 void bch2_trans_node_iter_init(struct btree_trans *trans, 2897 struct btree_iter *iter, 2898 enum btree_id btree_id, 2899 struct bpos pos, 2900 unsigned locks_want, 2901 unsigned depth, 2902 unsigned flags) 2903 { 2904 flags |= BTREE_ITER_not_extents; 2905 flags |= BTREE_ITER_snapshot_field; 2906 flags |= BTREE_ITER_all_snapshots; 2907 2908 bch2_trans_iter_init_common(trans, iter, btree_id, pos, locks_want, depth, 2909 __bch2_btree_iter_flags(trans, btree_id, flags), 2910 _RET_IP_); 2911 2912 iter->min_depth = depth; 2913 2914 struct btree_path *path = btree_iter_path(trans, iter); 2915 BUG_ON(path->locks_want < min(locks_want, BTREE_MAX_DEPTH)); 2916 BUG_ON(path->level != depth); 2917 BUG_ON(iter->min_depth != depth); 2918 } 2919 2920 void bch2_trans_copy_iter(struct btree_iter *dst, struct btree_iter *src) 2921 { 2922 struct btree_trans *trans = src->trans; 2923 2924 *dst = *src; 2925 #ifdef TRACK_PATH_ALLOCATED 2926 dst->ip_allocated = _RET_IP_; 2927 #endif 2928 if (src->path) 2929 __btree_path_get(trans, trans->paths + src->path, src->flags & BTREE_ITER_intent); 2930 if (src->update_path) 2931 __btree_path_get(trans, trans->paths + src->update_path, src->flags & BTREE_ITER_intent); 2932 dst->key_cache_path = 0; 2933 } 2934 2935 void *__bch2_trans_kmalloc(struct btree_trans *trans, size_t size) 2936 { 2937 struct bch_fs *c = trans->c; 2938 unsigned new_top = trans->mem_top + size; 2939 unsigned old_bytes = trans->mem_bytes; 2940 unsigned new_bytes = roundup_pow_of_two(new_top); 2941 int ret; 2942 void *new_mem; 2943 void *p; 2944 2945 WARN_ON_ONCE(new_bytes > BTREE_TRANS_MEM_MAX); 2946 2947 struct btree_transaction_stats *s = btree_trans_stats(trans); 2948 s->max_mem = max(s->max_mem, new_bytes); 2949 2950 if (trans->used_mempool) { 2951 if (trans->mem_bytes >= new_bytes) 2952 goto out_change_top; 2953 2954 /* No more space from mempool item, need malloc new one */ 2955 new_mem = kmalloc(new_bytes, GFP_NOWAIT|__GFP_NOWARN); 2956 if (unlikely(!new_mem)) { 2957 bch2_trans_unlock(trans); 2958 2959 new_mem = kmalloc(new_bytes, GFP_KERNEL); 2960 if (!new_mem) 2961 return ERR_PTR(-BCH_ERR_ENOMEM_trans_kmalloc); 2962 2963 ret = bch2_trans_relock(trans); 2964 if (ret) { 2965 kfree(new_mem); 2966 return ERR_PTR(ret); 2967 } 2968 } 2969 memcpy(new_mem, trans->mem, trans->mem_top); 2970 trans->used_mempool = false; 2971 mempool_free(trans->mem, &c->btree_trans_mem_pool); 2972 goto out_new_mem; 2973 } 2974 2975 new_mem = krealloc(trans->mem, new_bytes, GFP_NOWAIT|__GFP_NOWARN); 2976 if (unlikely(!new_mem)) { 2977 bch2_trans_unlock(trans); 2978 2979 new_mem = krealloc(trans->mem, new_bytes, GFP_KERNEL); 2980 if (!new_mem && new_bytes <= BTREE_TRANS_MEM_MAX) { 2981 new_mem = mempool_alloc(&c->btree_trans_mem_pool, GFP_KERNEL); 2982 new_bytes = BTREE_TRANS_MEM_MAX; 2983 memcpy(new_mem, trans->mem, trans->mem_top); 2984 trans->used_mempool = true; 2985 kfree(trans->mem); 2986 } 2987 2988 if (!new_mem) 2989 return ERR_PTR(-BCH_ERR_ENOMEM_trans_kmalloc); 2990 2991 trans->mem = new_mem; 2992 trans->mem_bytes = new_bytes; 2993 2994 ret = bch2_trans_relock(trans); 2995 if (ret) 2996 return ERR_PTR(ret); 2997 } 2998 out_new_mem: 2999 trans->mem = new_mem; 3000 trans->mem_bytes = new_bytes; 3001 3002 if (old_bytes) { 3003 trace_and_count(c, trans_restart_mem_realloced, trans, _RET_IP_, new_bytes); 3004 return ERR_PTR(btree_trans_restart(trans, BCH_ERR_transaction_restart_mem_realloced)); 3005 } 3006 out_change_top: 3007 p = trans->mem + trans->mem_top; 3008 trans->mem_top += size; 3009 memset(p, 0, size); 3010 return p; 3011 } 3012 3013 static inline void check_srcu_held_too_long(struct btree_trans *trans) 3014 { 3015 WARN(trans->srcu_held && time_after(jiffies, trans->srcu_lock_time + HZ * 10), 3016 "btree trans held srcu lock (delaying memory reclaim) for %lu seconds", 3017 (jiffies - trans->srcu_lock_time) / HZ); 3018 } 3019 3020 void bch2_trans_srcu_unlock(struct btree_trans *trans) 3021 { 3022 if (trans->srcu_held) { 3023 struct bch_fs *c = trans->c; 3024 struct btree_path *path; 3025 unsigned i; 3026 3027 trans_for_each_path(trans, path, i) 3028 if (path->cached && !btree_node_locked(path, 0)) 3029 path->l[0].b = ERR_PTR(-BCH_ERR_no_btree_node_srcu_reset); 3030 3031 check_srcu_held_too_long(trans); 3032 srcu_read_unlock(&c->btree_trans_barrier, trans->srcu_idx); 3033 trans->srcu_held = false; 3034 } 3035 } 3036 3037 static void bch2_trans_srcu_lock(struct btree_trans *trans) 3038 { 3039 if (!trans->srcu_held) { 3040 trans->srcu_idx = srcu_read_lock(&trans->c->btree_trans_barrier); 3041 trans->srcu_lock_time = jiffies; 3042 trans->srcu_held = true; 3043 } 3044 } 3045 3046 /** 3047 * bch2_trans_begin() - reset a transaction after a interrupted attempt 3048 * @trans: transaction to reset 3049 * 3050 * Returns: current restart counter, to be used with trans_was_restarted() 3051 * 3052 * While iterating over nodes or updating nodes a attempt to lock a btree node 3053 * may return BCH_ERR_transaction_restart when the trylock fails. When this 3054 * occurs bch2_trans_begin() should be called and the transaction retried. 3055 */ 3056 u32 bch2_trans_begin(struct btree_trans *trans) 3057 { 3058 struct btree_path *path; 3059 unsigned i; 3060 u64 now; 3061 3062 bch2_trans_reset_updates(trans); 3063 3064 trans->restart_count++; 3065 trans->mem_top = 0; 3066 trans->journal_entries = NULL; 3067 3068 trans_for_each_path(trans, path, i) { 3069 path->should_be_locked = false; 3070 3071 /* 3072 * If the transaction wasn't restarted, we're presuming to be 3073 * doing something new: dont keep iterators excpt the ones that 3074 * are in use - except for the subvolumes btree: 3075 */ 3076 if (!trans->restarted && path->btree_id != BTREE_ID_subvolumes) 3077 path->preserve = false; 3078 3079 /* 3080 * XXX: we probably shouldn't be doing this if the transaction 3081 * was restarted, but currently we still overflow transaction 3082 * iterators if we do that 3083 */ 3084 if (!path->ref && !path->preserve) 3085 __bch2_path_free(trans, i); 3086 else 3087 path->preserve = false; 3088 } 3089 3090 now = local_clock(); 3091 3092 if (!IS_ENABLED(CONFIG_BCACHEFS_NO_LATENCY_ACCT) && 3093 time_after64(now, trans->last_begin_time + 10)) 3094 __bch2_time_stats_update(&btree_trans_stats(trans)->duration, 3095 trans->last_begin_time, now); 3096 3097 if (!trans->restarted && 3098 (need_resched() || 3099 time_after64(now, trans->last_begin_time + BTREE_TRANS_MAX_LOCK_HOLD_TIME_NS))) { 3100 bch2_trans_unlock(trans); 3101 cond_resched(); 3102 now = local_clock(); 3103 } 3104 trans->last_begin_time = now; 3105 3106 if (unlikely(trans->srcu_held && 3107 time_after(jiffies, trans->srcu_lock_time + msecs_to_jiffies(10)))) 3108 bch2_trans_srcu_unlock(trans); 3109 3110 trans->last_begin_ip = _RET_IP_; 3111 3112 trans_set_locked(trans); 3113 3114 if (trans->restarted) { 3115 bch2_btree_path_traverse_all(trans); 3116 trans->notrace_relock_fail = false; 3117 } 3118 3119 bch2_trans_verify_not_unlocked(trans); 3120 return trans->restart_count; 3121 } 3122 3123 const char *bch2_btree_transaction_fns[BCH_TRANSACTIONS_NR] = { "(unknown)" }; 3124 3125 unsigned bch2_trans_get_fn_idx(const char *fn) 3126 { 3127 for (unsigned i = 0; i < ARRAY_SIZE(bch2_btree_transaction_fns); i++) 3128 if (!bch2_btree_transaction_fns[i] || 3129 bch2_btree_transaction_fns[i] == fn) { 3130 bch2_btree_transaction_fns[i] = fn; 3131 return i; 3132 } 3133 3134 pr_warn_once("BCH_TRANSACTIONS_NR not big enough!"); 3135 return 0; 3136 } 3137 3138 struct btree_trans *__bch2_trans_get(struct bch_fs *c, unsigned fn_idx) 3139 __acquires(&c->btree_trans_barrier) 3140 { 3141 struct btree_trans *trans; 3142 3143 if (IS_ENABLED(__KERNEL__)) { 3144 trans = this_cpu_xchg(c->btree_trans_bufs->trans, NULL); 3145 if (trans) { 3146 memset(trans, 0, offsetof(struct btree_trans, list)); 3147 goto got_trans; 3148 } 3149 } 3150 3151 trans = mempool_alloc(&c->btree_trans_pool, GFP_NOFS); 3152 memset(trans, 0, sizeof(*trans)); 3153 3154 seqmutex_lock(&c->btree_trans_lock); 3155 if (IS_ENABLED(CONFIG_BCACHEFS_DEBUG)) { 3156 struct btree_trans *pos; 3157 pid_t pid = current->pid; 3158 3159 trans->locking_wait.task = current; 3160 3161 list_for_each_entry(pos, &c->btree_trans_list, list) { 3162 struct task_struct *pos_task = READ_ONCE(pos->locking_wait.task); 3163 /* 3164 * We'd much prefer to be stricter here and completely 3165 * disallow multiple btree_trans in the same thread - 3166 * but the data move path calls bch2_write when we 3167 * already have a btree_trans initialized. 3168 */ 3169 BUG_ON(pos_task && 3170 pid == pos_task->pid && 3171 pos->locked); 3172 } 3173 } 3174 3175 list_add(&trans->list, &c->btree_trans_list); 3176 seqmutex_unlock(&c->btree_trans_lock); 3177 got_trans: 3178 trans->c = c; 3179 trans->last_begin_time = local_clock(); 3180 trans->fn_idx = fn_idx; 3181 trans->locking_wait.task = current; 3182 trans->journal_replay_not_finished = 3183 unlikely(!test_bit(JOURNAL_replay_done, &c->journal.flags)) && 3184 atomic_inc_not_zero(&c->journal_keys.ref); 3185 trans->nr_paths = ARRAY_SIZE(trans->_paths); 3186 trans->paths_allocated = trans->_paths_allocated; 3187 trans->sorted = trans->_sorted; 3188 trans->paths = trans->_paths; 3189 trans->updates = trans->_updates; 3190 3191 *trans_paths_nr(trans->paths) = BTREE_ITER_INITIAL; 3192 3193 trans->paths_allocated[0] = 1; 3194 3195 static struct lock_class_key lockdep_key; 3196 lockdep_init_map(&trans->dep_map, "bcachefs_btree", &lockdep_key, 0); 3197 3198 if (fn_idx < BCH_TRANSACTIONS_NR) { 3199 trans->fn = bch2_btree_transaction_fns[fn_idx]; 3200 3201 struct btree_transaction_stats *s = &c->btree_transaction_stats[fn_idx]; 3202 3203 if (s->max_mem) { 3204 unsigned expected_mem_bytes = roundup_pow_of_two(s->max_mem); 3205 3206 trans->mem = kmalloc(expected_mem_bytes, GFP_KERNEL); 3207 if (likely(trans->mem)) 3208 trans->mem_bytes = expected_mem_bytes; 3209 } 3210 3211 trans->nr_paths_max = s->nr_max_paths; 3212 trans->journal_entries_size = s->journal_entries_size; 3213 } 3214 3215 trans->srcu_idx = srcu_read_lock(&c->btree_trans_barrier); 3216 trans->srcu_lock_time = jiffies; 3217 trans->srcu_held = true; 3218 trans_set_locked(trans); 3219 3220 closure_init_stack_release(&trans->ref); 3221 return trans; 3222 } 3223 3224 static void check_btree_paths_leaked(struct btree_trans *trans) 3225 { 3226 #ifdef CONFIG_BCACHEFS_DEBUG 3227 struct bch_fs *c = trans->c; 3228 struct btree_path *path; 3229 unsigned i; 3230 3231 trans_for_each_path(trans, path, i) 3232 if (path->ref) 3233 goto leaked; 3234 return; 3235 leaked: 3236 bch_err(c, "btree paths leaked from %s!", trans->fn); 3237 trans_for_each_path(trans, path, i) 3238 if (path->ref) 3239 printk(KERN_ERR " btree %s %pS\n", 3240 bch2_btree_id_str(path->btree_id), 3241 (void *) path->ip_allocated); 3242 /* Be noisy about this: */ 3243 bch2_fatal_error(c); 3244 #endif 3245 } 3246 3247 void bch2_trans_put(struct btree_trans *trans) 3248 __releases(&c->btree_trans_barrier) 3249 { 3250 struct bch_fs *c = trans->c; 3251 3252 bch2_trans_unlock(trans); 3253 3254 trans_for_each_update(trans, i) 3255 __btree_path_put(trans, trans->paths + i->path, true); 3256 trans->nr_updates = 0; 3257 3258 check_btree_paths_leaked(trans); 3259 3260 if (trans->srcu_held) { 3261 check_srcu_held_too_long(trans); 3262 srcu_read_unlock(&c->btree_trans_barrier, trans->srcu_idx); 3263 } 3264 3265 if (unlikely(trans->journal_replay_not_finished)) 3266 bch2_journal_keys_put(c); 3267 3268 /* 3269 * trans->ref protects trans->locking_wait.task, btree_paths array; used 3270 * by cycle detector 3271 */ 3272 closure_return_sync(&trans->ref); 3273 trans->locking_wait.task = NULL; 3274 3275 unsigned long *paths_allocated = trans->paths_allocated; 3276 trans->paths_allocated = NULL; 3277 trans->paths = NULL; 3278 3279 if (paths_allocated != trans->_paths_allocated) 3280 kvfree_rcu_mightsleep(paths_allocated); 3281 3282 if (trans->used_mempool) 3283 mempool_free(trans->mem, &c->btree_trans_mem_pool); 3284 else 3285 kfree(trans->mem); 3286 3287 /* Userspace doesn't have a real percpu implementation: */ 3288 if (IS_ENABLED(__KERNEL__)) 3289 trans = this_cpu_xchg(c->btree_trans_bufs->trans, trans); 3290 3291 if (trans) { 3292 seqmutex_lock(&c->btree_trans_lock); 3293 list_del(&trans->list); 3294 seqmutex_unlock(&c->btree_trans_lock); 3295 3296 mempool_free(trans, &c->btree_trans_pool); 3297 } 3298 } 3299 3300 bool bch2_current_has_btree_trans(struct bch_fs *c) 3301 { 3302 seqmutex_lock(&c->btree_trans_lock); 3303 struct btree_trans *trans; 3304 bool ret = false; 3305 list_for_each_entry(trans, &c->btree_trans_list, list) 3306 if (trans->locking_wait.task == current && 3307 trans->locked) { 3308 ret = true; 3309 break; 3310 } 3311 seqmutex_unlock(&c->btree_trans_lock); 3312 return ret; 3313 } 3314 3315 static void __maybe_unused 3316 bch2_btree_bkey_cached_common_to_text(struct printbuf *out, 3317 struct btree_bkey_cached_common *b) 3318 { 3319 struct six_lock_count c = six_lock_counts(&b->lock); 3320 struct task_struct *owner; 3321 pid_t pid; 3322 3323 rcu_read_lock(); 3324 owner = READ_ONCE(b->lock.owner); 3325 pid = owner ? owner->pid : 0; 3326 rcu_read_unlock(); 3327 3328 prt_printf(out, "\t%px %c l=%u %s:", b, b->cached ? 'c' : 'b', 3329 b->level, bch2_btree_id_str(b->btree_id)); 3330 bch2_bpos_to_text(out, btree_node_pos(b)); 3331 3332 prt_printf(out, "\t locks %u:%u:%u held by pid %u", 3333 c.n[0], c.n[1], c.n[2], pid); 3334 } 3335 3336 void bch2_btree_trans_to_text(struct printbuf *out, struct btree_trans *trans) 3337 { 3338 struct btree_bkey_cached_common *b; 3339 static char lock_types[] = { 'r', 'i', 'w' }; 3340 struct task_struct *task = READ_ONCE(trans->locking_wait.task); 3341 unsigned l, idx; 3342 3343 /* before rcu_read_lock(): */ 3344 bch2_printbuf_make_room(out, 4096); 3345 3346 if (!out->nr_tabstops) { 3347 printbuf_tabstop_push(out, 16); 3348 printbuf_tabstop_push(out, 32); 3349 } 3350 3351 prt_printf(out, "%i %s\n", task ? task->pid : 0, trans->fn); 3352 3353 /* trans->paths is rcu protected vs. freeing */ 3354 rcu_read_lock(); 3355 out->atomic++; 3356 3357 struct btree_path *paths = rcu_dereference(trans->paths); 3358 if (!paths) 3359 goto out; 3360 3361 unsigned long *paths_allocated = trans_paths_allocated(paths); 3362 3363 trans_for_each_path_idx_from(paths_allocated, *trans_paths_nr(paths), idx, 1) { 3364 struct btree_path *path = paths + idx; 3365 if (!path->nodes_locked) 3366 continue; 3367 3368 prt_printf(out, " path %u %c l=%u %s:", 3369 idx, 3370 path->cached ? 'c' : 'b', 3371 path->level, 3372 bch2_btree_id_str(path->btree_id)); 3373 bch2_bpos_to_text(out, path->pos); 3374 prt_newline(out); 3375 3376 for (l = 0; l < BTREE_MAX_DEPTH; l++) { 3377 if (btree_node_locked(path, l) && 3378 !IS_ERR_OR_NULL(b = (void *) READ_ONCE(path->l[l].b))) { 3379 prt_printf(out, " %c l=%u ", 3380 lock_types[btree_node_locked_type(path, l)], l); 3381 bch2_btree_bkey_cached_common_to_text(out, b); 3382 prt_newline(out); 3383 } 3384 } 3385 } 3386 3387 b = READ_ONCE(trans->locking); 3388 if (b) { 3389 prt_printf(out, " blocked for %lluus on\n", 3390 div_u64(local_clock() - trans->locking_wait.start_time, 1000)); 3391 prt_printf(out, " %c", lock_types[trans->locking_wait.lock_want]); 3392 bch2_btree_bkey_cached_common_to_text(out, b); 3393 prt_newline(out); 3394 } 3395 out: 3396 --out->atomic; 3397 rcu_read_unlock(); 3398 } 3399 3400 void bch2_fs_btree_iter_exit(struct bch_fs *c) 3401 { 3402 struct btree_transaction_stats *s; 3403 struct btree_trans *trans; 3404 int cpu; 3405 3406 if (c->btree_trans_bufs) 3407 for_each_possible_cpu(cpu) { 3408 struct btree_trans *trans = 3409 per_cpu_ptr(c->btree_trans_bufs, cpu)->trans; 3410 3411 if (trans) { 3412 seqmutex_lock(&c->btree_trans_lock); 3413 list_del(&trans->list); 3414 seqmutex_unlock(&c->btree_trans_lock); 3415 } 3416 kfree(trans); 3417 } 3418 free_percpu(c->btree_trans_bufs); 3419 3420 trans = list_first_entry_or_null(&c->btree_trans_list, struct btree_trans, list); 3421 if (trans) 3422 panic("%s leaked btree_trans\n", trans->fn); 3423 3424 for (s = c->btree_transaction_stats; 3425 s < c->btree_transaction_stats + ARRAY_SIZE(c->btree_transaction_stats); 3426 s++) { 3427 kfree(s->max_paths_text); 3428 bch2_time_stats_exit(&s->lock_hold_times); 3429 } 3430 3431 if (c->btree_trans_barrier_initialized) { 3432 synchronize_srcu_expedited(&c->btree_trans_barrier); 3433 cleanup_srcu_struct(&c->btree_trans_barrier); 3434 } 3435 mempool_exit(&c->btree_trans_mem_pool); 3436 mempool_exit(&c->btree_trans_pool); 3437 } 3438 3439 void bch2_fs_btree_iter_init_early(struct bch_fs *c) 3440 { 3441 struct btree_transaction_stats *s; 3442 3443 for (s = c->btree_transaction_stats; 3444 s < c->btree_transaction_stats + ARRAY_SIZE(c->btree_transaction_stats); 3445 s++) { 3446 bch2_time_stats_init(&s->duration); 3447 bch2_time_stats_init(&s->lock_hold_times); 3448 mutex_init(&s->lock); 3449 } 3450 3451 INIT_LIST_HEAD(&c->btree_trans_list); 3452 seqmutex_init(&c->btree_trans_lock); 3453 } 3454 3455 int bch2_fs_btree_iter_init(struct bch_fs *c) 3456 { 3457 int ret; 3458 3459 c->btree_trans_bufs = alloc_percpu(struct btree_trans_buf); 3460 if (!c->btree_trans_bufs) 3461 return -ENOMEM; 3462 3463 ret = mempool_init_kmalloc_pool(&c->btree_trans_pool, 1, 3464 sizeof(struct btree_trans)) ?: 3465 mempool_init_kmalloc_pool(&c->btree_trans_mem_pool, 1, 3466 BTREE_TRANS_MEM_MAX) ?: 3467 init_srcu_struct(&c->btree_trans_barrier); 3468 if (ret) 3469 return ret; 3470 3471 /* 3472 * static annotation (hackily done) for lock ordering of reclaim vs. 3473 * btree node locks: 3474 */ 3475 #ifdef CONFIG_LOCKDEP 3476 fs_reclaim_acquire(GFP_KERNEL); 3477 struct btree_trans *trans = bch2_trans_get(c); 3478 trans_set_locked(trans); 3479 bch2_trans_put(trans); 3480 fs_reclaim_release(GFP_KERNEL); 3481 #endif 3482 3483 c->btree_trans_barrier_initialized = true; 3484 return 0; 3485 3486 } 3487