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->paths[idx], false); 1014 ret = bch2_btree_path_traverse_one(trans, idx, 0, _THIS_IP_); 1015 __btree_path_put(&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 /* 1135 * Ensure we obey path->should_be_locked: if it's set, we can't unlock 1136 * and re-traverse the path without a transaction restart: 1137 */ 1138 if (path->should_be_locked) { 1139 ret = bch2_btree_path_relock(trans, path, trace_ip); 1140 goto out; 1141 } 1142 1143 if (path->cached) { 1144 ret = bch2_btree_path_traverse_cached(trans, path, flags); 1145 goto out; 1146 } 1147 1148 path = &trans->paths[path_idx]; 1149 1150 if (unlikely(path->level >= BTREE_MAX_DEPTH)) 1151 goto out_uptodate; 1152 1153 path->level = btree_path_up_until_good_node(trans, path, 0); 1154 unsigned max_level = path->level; 1155 1156 EBUG_ON(btree_path_node(path, path->level) && 1157 !btree_node_locked(path, path->level)); 1158 1159 /* 1160 * Note: path->nodes[path->level] may be temporarily NULL here - that 1161 * would indicate to other code that we got to the end of the btree, 1162 * here it indicates that relocking the root failed - it's critical that 1163 * btree_path_lock_root() comes next and that it can't fail 1164 */ 1165 while (path->level > depth_want) { 1166 ret = btree_path_node(path, path->level) 1167 ? btree_path_down(trans, path, flags, trace_ip) 1168 : btree_path_lock_root(trans, path, depth_want, trace_ip); 1169 if (unlikely(ret)) { 1170 if (ret == 1) { 1171 /* 1172 * No nodes at this level - got to the end of 1173 * the btree: 1174 */ 1175 ret = 0; 1176 goto out; 1177 } 1178 1179 __bch2_btree_path_unlock(trans, path); 1180 path->level = depth_want; 1181 path->l[path->level].b = ERR_PTR(ret); 1182 goto out; 1183 } 1184 } 1185 1186 if (unlikely(max_level > path->level)) { 1187 struct btree_path *linked; 1188 unsigned iter; 1189 1190 trans_for_each_path_with_node(trans, path_l(path)->b, linked, iter) 1191 for (unsigned j = path->level + 1; j < max_level; j++) 1192 linked->l[j] = path->l[j]; 1193 } 1194 1195 out_uptodate: 1196 path->uptodate = BTREE_ITER_UPTODATE; 1197 out: 1198 if (bch2_err_matches(ret, BCH_ERR_transaction_restart) != !!trans->restarted) 1199 panic("ret %s (%i) trans->restarted %s (%i)\n", 1200 bch2_err_str(ret), ret, 1201 bch2_err_str(trans->restarted), trans->restarted); 1202 bch2_btree_path_verify(trans, path); 1203 return ret; 1204 } 1205 1206 static inline void btree_path_copy(struct btree_trans *trans, struct btree_path *dst, 1207 struct btree_path *src) 1208 { 1209 unsigned i, offset = offsetof(struct btree_path, pos); 1210 1211 memcpy((void *) dst + offset, 1212 (void *) src + offset, 1213 sizeof(struct btree_path) - offset); 1214 1215 for (i = 0; i < BTREE_MAX_DEPTH; i++) { 1216 unsigned t = btree_node_locked_type(dst, i); 1217 1218 if (t != BTREE_NODE_UNLOCKED) 1219 six_lock_increment(&dst->l[i].b->c.lock, t); 1220 } 1221 } 1222 1223 static btree_path_idx_t btree_path_clone(struct btree_trans *trans, btree_path_idx_t src, 1224 bool intent, unsigned long ip) 1225 { 1226 btree_path_idx_t new = btree_path_alloc(trans, src); 1227 btree_path_copy(trans, trans->paths + new, trans->paths + src); 1228 __btree_path_get(trans->paths + new, intent); 1229 #ifdef TRACK_PATH_ALLOCATED 1230 trans->paths[new].ip_allocated = ip; 1231 #endif 1232 return new; 1233 } 1234 1235 __flatten 1236 btree_path_idx_t __bch2_btree_path_make_mut(struct btree_trans *trans, 1237 btree_path_idx_t path, bool intent, unsigned long ip) 1238 { 1239 __btree_path_put(trans->paths + path, intent); 1240 path = btree_path_clone(trans, path, intent, ip); 1241 trans->paths[path].preserve = false; 1242 return path; 1243 } 1244 1245 btree_path_idx_t __must_check 1246 __bch2_btree_path_set_pos(struct btree_trans *trans, 1247 btree_path_idx_t path_idx, struct bpos new_pos, 1248 bool intent, unsigned long ip) 1249 { 1250 int cmp = bpos_cmp(new_pos, trans->paths[path_idx].pos); 1251 1252 bch2_trans_verify_not_in_restart(trans); 1253 EBUG_ON(!trans->paths[path_idx].ref); 1254 1255 path_idx = bch2_btree_path_make_mut(trans, path_idx, intent, ip); 1256 1257 struct btree_path *path = trans->paths + path_idx; 1258 path->pos = new_pos; 1259 trans->paths_sorted = false; 1260 1261 if (unlikely(path->cached)) { 1262 btree_node_unlock(trans, path, 0); 1263 path->l[0].b = ERR_PTR(-BCH_ERR_no_btree_node_up); 1264 btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE); 1265 goto out; 1266 } 1267 1268 unsigned level = btree_path_up_until_good_node(trans, path, cmp); 1269 1270 if (btree_path_node(path, level)) { 1271 struct btree_path_level *l = &path->l[level]; 1272 1273 BUG_ON(!btree_node_locked(path, level)); 1274 /* 1275 * We might have to skip over many keys, or just a few: try 1276 * advancing the node iterator, and if we have to skip over too 1277 * many keys just reinit it (or if we're rewinding, since that 1278 * is expensive). 1279 */ 1280 if (cmp < 0 || 1281 !btree_path_advance_to_pos(path, l, 8)) 1282 bch2_btree_node_iter_init(&l->iter, l->b, &path->pos); 1283 1284 /* 1285 * Iterators to interior nodes should always be pointed at the first non 1286 * whiteout: 1287 */ 1288 if (unlikely(level)) 1289 bch2_btree_node_iter_peek(&l->iter, l->b); 1290 } 1291 1292 if (unlikely(level != path->level)) { 1293 btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE); 1294 __bch2_btree_path_unlock(trans, path); 1295 } 1296 out: 1297 bch2_btree_path_verify(trans, path); 1298 return path_idx; 1299 } 1300 1301 /* Btree path: main interface: */ 1302 1303 static struct btree_path *have_path_at_pos(struct btree_trans *trans, struct btree_path *path) 1304 { 1305 struct btree_path *sib; 1306 1307 sib = prev_btree_path(trans, path); 1308 if (sib && !btree_path_cmp(sib, path)) 1309 return sib; 1310 1311 sib = next_btree_path(trans, path); 1312 if (sib && !btree_path_cmp(sib, path)) 1313 return sib; 1314 1315 return NULL; 1316 } 1317 1318 static struct btree_path *have_node_at_pos(struct btree_trans *trans, struct btree_path *path) 1319 { 1320 struct btree_path *sib; 1321 1322 sib = prev_btree_path(trans, path); 1323 if (sib && sib->level == path->level && path_l(sib)->b == path_l(path)->b) 1324 return sib; 1325 1326 sib = next_btree_path(trans, path); 1327 if (sib && sib->level == path->level && path_l(sib)->b == path_l(path)->b) 1328 return sib; 1329 1330 return NULL; 1331 } 1332 1333 static inline void __bch2_path_free(struct btree_trans *trans, btree_path_idx_t path) 1334 { 1335 __bch2_btree_path_unlock(trans, trans->paths + path); 1336 btree_path_list_remove(trans, trans->paths + path); 1337 __clear_bit(path, trans->paths_allocated); 1338 } 1339 1340 static bool bch2_btree_path_can_relock(struct btree_trans *trans, struct btree_path *path) 1341 { 1342 unsigned l = path->level; 1343 1344 do { 1345 if (!btree_path_node(path, l)) 1346 break; 1347 1348 if (!is_btree_node(path, l)) 1349 return false; 1350 1351 if (path->l[l].lock_seq != path->l[l].b->c.lock.seq) 1352 return false; 1353 1354 l++; 1355 } while (l < path->locks_want); 1356 1357 return true; 1358 } 1359 1360 void bch2_path_put(struct btree_trans *trans, btree_path_idx_t path_idx, bool intent) 1361 { 1362 struct btree_path *path = trans->paths + path_idx, *dup; 1363 1364 if (!__btree_path_put(path, intent)) 1365 return; 1366 1367 dup = path->preserve 1368 ? have_path_at_pos(trans, path) 1369 : have_node_at_pos(trans, path); 1370 1371 if (!dup && !(!path->preserve && !is_btree_node(path, path->level))) 1372 return; 1373 1374 if (path->should_be_locked && !trans->restarted) { 1375 if (!dup) 1376 return; 1377 1378 if (!(trans->locked 1379 ? bch2_btree_path_relock_norestart(trans, dup) 1380 : bch2_btree_path_can_relock(trans, dup))) 1381 return; 1382 } 1383 1384 if (dup) { 1385 dup->preserve |= path->preserve; 1386 dup->should_be_locked |= path->should_be_locked; 1387 } 1388 1389 __bch2_path_free(trans, path_idx); 1390 } 1391 1392 static void bch2_path_put_nokeep(struct btree_trans *trans, btree_path_idx_t path, 1393 bool intent) 1394 { 1395 if (!__btree_path_put(trans->paths + path, intent)) 1396 return; 1397 1398 __bch2_path_free(trans, path); 1399 } 1400 1401 void __noreturn bch2_trans_restart_error(struct btree_trans *trans, u32 restart_count) 1402 { 1403 panic("trans->restart_count %u, should be %u, last restarted by %pS\n", 1404 trans->restart_count, restart_count, 1405 (void *) trans->last_begin_ip); 1406 } 1407 1408 void __noreturn bch2_trans_in_restart_error(struct btree_trans *trans) 1409 { 1410 panic("in transaction restart: %s, last restarted by %pS\n", 1411 bch2_err_str(trans->restarted), 1412 (void *) trans->last_restarted_ip); 1413 } 1414 1415 void __noreturn bch2_trans_unlocked_error(struct btree_trans *trans) 1416 { 1417 panic("trans should be locked, unlocked by %pS\n", 1418 (void *) trans->last_unlock_ip); 1419 } 1420 1421 noinline __cold 1422 void bch2_trans_updates_to_text(struct printbuf *buf, struct btree_trans *trans) 1423 { 1424 prt_printf(buf, "transaction updates for %s journal seq %llu\n", 1425 trans->fn, trans->journal_res.seq); 1426 printbuf_indent_add(buf, 2); 1427 1428 trans_for_each_update(trans, i) { 1429 struct bkey_s_c old = { &i->old_k, i->old_v }; 1430 1431 prt_printf(buf, "update: btree=%s cached=%u %pS\n", 1432 bch2_btree_id_str(i->btree_id), 1433 i->cached, 1434 (void *) i->ip_allocated); 1435 1436 prt_printf(buf, " old "); 1437 bch2_bkey_val_to_text(buf, trans->c, old); 1438 prt_newline(buf); 1439 1440 prt_printf(buf, " new "); 1441 bch2_bkey_val_to_text(buf, trans->c, bkey_i_to_s_c(i->k)); 1442 prt_newline(buf); 1443 } 1444 1445 for (struct jset_entry *e = trans->journal_entries; 1446 e != btree_trans_journal_entries_top(trans); 1447 e = vstruct_next(e)) 1448 bch2_journal_entry_to_text(buf, trans->c, e); 1449 1450 printbuf_indent_sub(buf, 2); 1451 } 1452 1453 noinline __cold 1454 void bch2_dump_trans_updates(struct btree_trans *trans) 1455 { 1456 struct printbuf buf = PRINTBUF; 1457 1458 bch2_trans_updates_to_text(&buf, trans); 1459 bch2_print_str(trans->c, buf.buf); 1460 printbuf_exit(&buf); 1461 } 1462 1463 static void bch2_btree_path_to_text_short(struct printbuf *out, struct btree_trans *trans, btree_path_idx_t path_idx) 1464 { 1465 struct btree_path *path = trans->paths + path_idx; 1466 1467 prt_printf(out, "path: idx %2u ref %u:%u %c %c %c btree=%s l=%u pos ", 1468 path_idx, path->ref, path->intent_ref, 1469 path->preserve ? 'P' : ' ', 1470 path->should_be_locked ? 'S' : ' ', 1471 path->cached ? 'C' : 'B', 1472 bch2_btree_id_str(path->btree_id), 1473 path->level); 1474 bch2_bpos_to_text(out, path->pos); 1475 1476 if (!path->cached && btree_node_locked(path, path->level)) { 1477 prt_char(out, ' '); 1478 struct btree *b = path_l(path)->b; 1479 bch2_bpos_to_text(out, b->data->min_key); 1480 prt_char(out, '-'); 1481 bch2_bpos_to_text(out, b->key.k.p); 1482 } 1483 1484 #ifdef TRACK_PATH_ALLOCATED 1485 prt_printf(out, " %pS", (void *) path->ip_allocated); 1486 #endif 1487 } 1488 1489 static const char *btree_node_locked_str(enum btree_node_locked_type t) 1490 { 1491 switch (t) { 1492 case BTREE_NODE_UNLOCKED: 1493 return "unlocked"; 1494 case BTREE_NODE_READ_LOCKED: 1495 return "read"; 1496 case BTREE_NODE_INTENT_LOCKED: 1497 return "intent"; 1498 case BTREE_NODE_WRITE_LOCKED: 1499 return "write"; 1500 default: 1501 return NULL; 1502 } 1503 } 1504 1505 void bch2_btree_path_to_text(struct printbuf *out, struct btree_trans *trans, btree_path_idx_t path_idx) 1506 { 1507 bch2_btree_path_to_text_short(out, trans, path_idx); 1508 1509 struct btree_path *path = trans->paths + path_idx; 1510 1511 prt_printf(out, " uptodate %u locks_want %u", path->uptodate, path->locks_want); 1512 prt_newline(out); 1513 1514 printbuf_indent_add(out, 2); 1515 for (unsigned l = 0; l < BTREE_MAX_DEPTH; l++) { 1516 prt_printf(out, "l=%u locks %s seq %u node ", l, 1517 btree_node_locked_str(btree_node_locked_type(path, l)), 1518 path->l[l].lock_seq); 1519 1520 int ret = PTR_ERR_OR_ZERO(path->l[l].b); 1521 if (ret) 1522 prt_str(out, bch2_err_str(ret)); 1523 else 1524 prt_printf(out, "%px", path->l[l].b); 1525 prt_newline(out); 1526 } 1527 printbuf_indent_sub(out, 2); 1528 } 1529 1530 static noinline __cold 1531 void __bch2_trans_paths_to_text(struct printbuf *out, struct btree_trans *trans, 1532 bool nosort) 1533 { 1534 struct trans_for_each_path_inorder_iter iter; 1535 1536 if (!nosort) 1537 btree_trans_sort_paths(trans); 1538 1539 trans_for_each_path_idx_inorder(trans, iter) { 1540 bch2_btree_path_to_text_short(out, trans, iter.path_idx); 1541 prt_newline(out); 1542 } 1543 } 1544 1545 noinline __cold 1546 void bch2_trans_paths_to_text(struct printbuf *out, struct btree_trans *trans) 1547 { 1548 __bch2_trans_paths_to_text(out, trans, false); 1549 } 1550 1551 static noinline __cold 1552 void __bch2_dump_trans_paths_updates(struct btree_trans *trans, bool nosort) 1553 { 1554 struct printbuf buf = PRINTBUF; 1555 1556 __bch2_trans_paths_to_text(&buf, trans, nosort); 1557 bch2_trans_updates_to_text(&buf, trans); 1558 1559 bch2_print_str(trans->c, buf.buf); 1560 printbuf_exit(&buf); 1561 } 1562 1563 noinline __cold 1564 void bch2_dump_trans_paths_updates(struct btree_trans *trans) 1565 { 1566 __bch2_dump_trans_paths_updates(trans, false); 1567 } 1568 1569 noinline __cold 1570 static void bch2_trans_update_max_paths(struct btree_trans *trans) 1571 { 1572 struct btree_transaction_stats *s = btree_trans_stats(trans); 1573 struct printbuf buf = PRINTBUF; 1574 size_t nr = bitmap_weight(trans->paths_allocated, trans->nr_paths); 1575 1576 bch2_trans_paths_to_text(&buf, trans); 1577 1578 if (!buf.allocation_failure) { 1579 mutex_lock(&s->lock); 1580 if (nr > s->nr_max_paths) { 1581 s->nr_max_paths = nr; 1582 swap(s->max_paths_text, buf.buf); 1583 } 1584 mutex_unlock(&s->lock); 1585 } 1586 1587 printbuf_exit(&buf); 1588 1589 trans->nr_paths_max = nr; 1590 } 1591 1592 noinline __cold 1593 int __bch2_btree_trans_too_many_iters(struct btree_trans *trans) 1594 { 1595 if (trace_trans_restart_too_many_iters_enabled()) { 1596 struct printbuf buf = PRINTBUF; 1597 1598 bch2_trans_paths_to_text(&buf, trans); 1599 trace_trans_restart_too_many_iters(trans, _THIS_IP_, buf.buf); 1600 printbuf_exit(&buf); 1601 } 1602 1603 count_event(trans->c, trans_restart_too_many_iters); 1604 1605 return btree_trans_restart(trans, BCH_ERR_transaction_restart_too_many_iters); 1606 } 1607 1608 static noinline void btree_path_overflow(struct btree_trans *trans) 1609 { 1610 bch2_dump_trans_paths_updates(trans); 1611 bch_err(trans->c, "trans path overflow"); 1612 } 1613 1614 static noinline void btree_paths_realloc(struct btree_trans *trans) 1615 { 1616 unsigned nr = trans->nr_paths * 2; 1617 1618 void *p = kvzalloc(BITS_TO_LONGS(nr) * sizeof(unsigned long) + 1619 sizeof(struct btree_trans_paths) + 1620 nr * sizeof(struct btree_path) + 1621 nr * sizeof(btree_path_idx_t) + 8 + 1622 nr * sizeof(struct btree_insert_entry), GFP_KERNEL|__GFP_NOFAIL); 1623 1624 unsigned long *paths_allocated = p; 1625 memcpy(paths_allocated, trans->paths_allocated, BITS_TO_LONGS(trans->nr_paths) * sizeof(unsigned long)); 1626 p += BITS_TO_LONGS(nr) * sizeof(unsigned long); 1627 1628 p += sizeof(struct btree_trans_paths); 1629 struct btree_path *paths = p; 1630 *trans_paths_nr(paths) = nr; 1631 memcpy(paths, trans->paths, trans->nr_paths * sizeof(struct btree_path)); 1632 p += nr * sizeof(struct btree_path); 1633 1634 btree_path_idx_t *sorted = p; 1635 memcpy(sorted, trans->sorted, trans->nr_sorted * sizeof(btree_path_idx_t)); 1636 p += nr * sizeof(btree_path_idx_t) + 8; 1637 1638 struct btree_insert_entry *updates = p; 1639 memcpy(updates, trans->updates, trans->nr_paths * sizeof(struct btree_insert_entry)); 1640 1641 unsigned long *old = trans->paths_allocated; 1642 1643 rcu_assign_pointer(trans->paths_allocated, paths_allocated); 1644 rcu_assign_pointer(trans->paths, paths); 1645 rcu_assign_pointer(trans->sorted, sorted); 1646 rcu_assign_pointer(trans->updates, updates); 1647 1648 trans->nr_paths = nr; 1649 1650 if (old != trans->_paths_allocated) 1651 kfree_rcu_mightsleep(old); 1652 } 1653 1654 static inline btree_path_idx_t btree_path_alloc(struct btree_trans *trans, 1655 btree_path_idx_t pos) 1656 { 1657 btree_path_idx_t idx = find_first_zero_bit(trans->paths_allocated, trans->nr_paths); 1658 1659 if (unlikely(idx == trans->nr_paths)) { 1660 if (trans->nr_paths == BTREE_ITER_MAX) { 1661 btree_path_overflow(trans); 1662 return 0; 1663 } 1664 1665 btree_paths_realloc(trans); 1666 } 1667 1668 /* 1669 * Do this before marking the new path as allocated, since it won't be 1670 * initialized yet: 1671 */ 1672 if (unlikely(idx > trans->nr_paths_max)) 1673 bch2_trans_update_max_paths(trans); 1674 1675 __set_bit(idx, trans->paths_allocated); 1676 1677 struct btree_path *path = &trans->paths[idx]; 1678 path->ref = 0; 1679 path->intent_ref = 0; 1680 path->nodes_locked = 0; 1681 1682 btree_path_list_add(trans, pos, idx); 1683 trans->paths_sorted = false; 1684 return idx; 1685 } 1686 1687 btree_path_idx_t bch2_path_get(struct btree_trans *trans, 1688 enum btree_id btree_id, struct bpos pos, 1689 unsigned locks_want, unsigned level, 1690 unsigned flags, unsigned long ip) 1691 { 1692 struct btree_path *path; 1693 bool cached = flags & BTREE_ITER_cached; 1694 bool intent = flags & BTREE_ITER_intent; 1695 struct trans_for_each_path_inorder_iter iter; 1696 btree_path_idx_t path_pos = 0, path_idx; 1697 1698 bch2_trans_verify_not_unlocked(trans); 1699 bch2_trans_verify_not_in_restart(trans); 1700 bch2_trans_verify_locks(trans); 1701 1702 btree_trans_sort_paths(trans); 1703 1704 trans_for_each_path_inorder(trans, path, iter) { 1705 if (__btree_path_cmp(path, 1706 btree_id, 1707 cached, 1708 pos, 1709 level) > 0) 1710 break; 1711 1712 path_pos = iter.path_idx; 1713 } 1714 1715 if (path_pos && 1716 trans->paths[path_pos].cached == cached && 1717 trans->paths[path_pos].btree_id == btree_id && 1718 trans->paths[path_pos].level == level) { 1719 __btree_path_get(trans->paths + path_pos, intent); 1720 path_idx = bch2_btree_path_set_pos(trans, path_pos, pos, intent, ip); 1721 path = trans->paths + path_idx; 1722 } else { 1723 path_idx = btree_path_alloc(trans, path_pos); 1724 path = trans->paths + path_idx; 1725 1726 __btree_path_get(path, intent); 1727 path->pos = pos; 1728 path->btree_id = btree_id; 1729 path->cached = cached; 1730 path->uptodate = BTREE_ITER_NEED_TRAVERSE; 1731 path->should_be_locked = false; 1732 path->level = level; 1733 path->locks_want = locks_want; 1734 path->nodes_locked = 0; 1735 for (unsigned i = 0; i < ARRAY_SIZE(path->l); i++) 1736 path->l[i].b = ERR_PTR(-BCH_ERR_no_btree_node_init); 1737 #ifdef TRACK_PATH_ALLOCATED 1738 path->ip_allocated = ip; 1739 #endif 1740 trans->paths_sorted = false; 1741 } 1742 1743 if (!(flags & BTREE_ITER_nopreserve)) 1744 path->preserve = true; 1745 1746 if (path->intent_ref) 1747 locks_want = max(locks_want, level + 1); 1748 1749 /* 1750 * If the path has locks_want greater than requested, we don't downgrade 1751 * it here - on transaction restart because btree node split needs to 1752 * upgrade locks, we might be putting/getting the iterator again. 1753 * Downgrading iterators only happens via bch2_trans_downgrade(), after 1754 * a successful transaction commit. 1755 */ 1756 1757 locks_want = min(locks_want, BTREE_MAX_DEPTH); 1758 if (locks_want > path->locks_want) 1759 bch2_btree_path_upgrade_noupgrade_sibs(trans, path, locks_want, NULL); 1760 1761 return path_idx; 1762 } 1763 1764 btree_path_idx_t bch2_path_get_unlocked_mut(struct btree_trans *trans, 1765 enum btree_id btree_id, 1766 unsigned level, 1767 struct bpos pos) 1768 { 1769 btree_path_idx_t path_idx = bch2_path_get(trans, btree_id, pos, level + 1, level, 1770 BTREE_ITER_nopreserve| 1771 BTREE_ITER_intent, _RET_IP_); 1772 path_idx = bch2_btree_path_make_mut(trans, path_idx, true, _RET_IP_); 1773 1774 struct btree_path *path = trans->paths + path_idx; 1775 bch2_btree_path_downgrade(trans, path); 1776 __bch2_btree_path_unlock(trans, path); 1777 return path_idx; 1778 } 1779 1780 struct bkey_s_c bch2_btree_path_peek_slot(struct btree_path *path, struct bkey *u) 1781 { 1782 1783 struct btree_path_level *l = path_l(path); 1784 struct bkey_packed *_k; 1785 struct bkey_s_c k; 1786 1787 if (unlikely(!l->b)) 1788 return bkey_s_c_null; 1789 1790 EBUG_ON(path->uptodate != BTREE_ITER_UPTODATE); 1791 EBUG_ON(!btree_node_locked(path, path->level)); 1792 1793 if (!path->cached) { 1794 _k = bch2_btree_node_iter_peek_all(&l->iter, l->b); 1795 k = _k ? bkey_disassemble(l->b, _k, u) : bkey_s_c_null; 1796 1797 EBUG_ON(k.k && bkey_deleted(k.k) && bpos_eq(k.k->p, path->pos)); 1798 1799 if (!k.k || !bpos_eq(path->pos, k.k->p)) 1800 goto hole; 1801 } else { 1802 struct bkey_cached *ck = (void *) path->l[0].b; 1803 if (!ck) 1804 return bkey_s_c_null; 1805 1806 EBUG_ON(path->btree_id != ck->key.btree_id || 1807 !bkey_eq(path->pos, ck->key.pos)); 1808 1809 *u = ck->k->k; 1810 k = bkey_i_to_s_c(ck->k); 1811 } 1812 1813 return k; 1814 hole: 1815 bkey_init(u); 1816 u->p = path->pos; 1817 return (struct bkey_s_c) { u, NULL }; 1818 } 1819 1820 1821 void bch2_set_btree_iter_dontneed(struct btree_iter *iter) 1822 { 1823 struct btree_trans *trans = iter->trans; 1824 1825 if (!iter->path || trans->restarted) 1826 return; 1827 1828 struct btree_path *path = btree_iter_path(trans, iter); 1829 path->preserve = false; 1830 if (path->ref == 1) 1831 path->should_be_locked = false; 1832 } 1833 /* Btree iterators: */ 1834 1835 int __must_check 1836 __bch2_btree_iter_traverse(struct btree_iter *iter) 1837 { 1838 return bch2_btree_path_traverse(iter->trans, iter->path, iter->flags); 1839 } 1840 1841 int __must_check 1842 bch2_btree_iter_traverse(struct btree_iter *iter) 1843 { 1844 struct btree_trans *trans = iter->trans; 1845 int ret; 1846 1847 bch2_trans_verify_not_unlocked(trans); 1848 1849 iter->path = bch2_btree_path_set_pos(trans, iter->path, 1850 btree_iter_search_key(iter), 1851 iter->flags & BTREE_ITER_intent, 1852 btree_iter_ip_allocated(iter)); 1853 1854 ret = bch2_btree_path_traverse(iter->trans, iter->path, iter->flags); 1855 if (ret) 1856 return ret; 1857 1858 struct btree_path *path = btree_iter_path(trans, iter); 1859 if (btree_path_node(path, path->level)) 1860 btree_path_set_should_be_locked(path); 1861 return 0; 1862 } 1863 1864 /* Iterate across nodes (leaf and interior nodes) */ 1865 1866 struct btree *bch2_btree_iter_peek_node(struct btree_iter *iter) 1867 { 1868 struct btree_trans *trans = iter->trans; 1869 struct btree *b = NULL; 1870 int ret; 1871 1872 EBUG_ON(trans->paths[iter->path].cached); 1873 bch2_btree_iter_verify(iter); 1874 1875 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags); 1876 if (ret) 1877 goto err; 1878 1879 struct btree_path *path = btree_iter_path(trans, iter); 1880 b = btree_path_node(path, path->level); 1881 if (!b) 1882 goto out; 1883 1884 BUG_ON(bpos_lt(b->key.k.p, iter->pos)); 1885 1886 bkey_init(&iter->k); 1887 iter->k.p = iter->pos = b->key.k.p; 1888 1889 iter->path = bch2_btree_path_set_pos(trans, iter->path, b->key.k.p, 1890 iter->flags & BTREE_ITER_intent, 1891 btree_iter_ip_allocated(iter)); 1892 btree_path_set_should_be_locked(btree_iter_path(trans, iter)); 1893 out: 1894 bch2_btree_iter_verify_entry_exit(iter); 1895 bch2_btree_iter_verify(iter); 1896 1897 return b; 1898 err: 1899 b = ERR_PTR(ret); 1900 goto out; 1901 } 1902 1903 /* Only kept for -tools */ 1904 struct btree *bch2_btree_iter_peek_node_and_restart(struct btree_iter *iter) 1905 { 1906 struct btree *b; 1907 1908 while (b = bch2_btree_iter_peek_node(iter), 1909 bch2_err_matches(PTR_ERR_OR_ZERO(b), BCH_ERR_transaction_restart)) 1910 bch2_trans_begin(iter->trans); 1911 1912 return b; 1913 } 1914 1915 struct btree *bch2_btree_iter_next_node(struct btree_iter *iter) 1916 { 1917 struct btree_trans *trans = iter->trans; 1918 struct btree *b = NULL; 1919 int ret; 1920 1921 EBUG_ON(trans->paths[iter->path].cached); 1922 bch2_trans_verify_not_in_restart(trans); 1923 bch2_btree_iter_verify(iter); 1924 1925 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags); 1926 if (ret) 1927 goto err; 1928 1929 1930 struct btree_path *path = btree_iter_path(trans, iter); 1931 1932 /* already at end? */ 1933 if (!btree_path_node(path, path->level)) 1934 return NULL; 1935 1936 /* got to end? */ 1937 if (!btree_path_node(path, path->level + 1)) { 1938 btree_path_set_level_up(trans, path); 1939 return NULL; 1940 } 1941 1942 if (!bch2_btree_node_relock(trans, path, path->level + 1)) { 1943 __bch2_btree_path_unlock(trans, path); 1944 path->l[path->level].b = ERR_PTR(-BCH_ERR_no_btree_node_relock); 1945 path->l[path->level + 1].b = ERR_PTR(-BCH_ERR_no_btree_node_relock); 1946 btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE); 1947 trace_and_count(trans->c, trans_restart_relock_next_node, trans, _THIS_IP_, path); 1948 ret = btree_trans_restart(trans, BCH_ERR_transaction_restart_relock); 1949 goto err; 1950 } 1951 1952 b = btree_path_node(path, path->level + 1); 1953 1954 if (bpos_eq(iter->pos, b->key.k.p)) { 1955 __btree_path_set_level_up(trans, path, path->level++); 1956 } else { 1957 if (btree_lock_want(path, path->level + 1) == BTREE_NODE_UNLOCKED) 1958 btree_node_unlock(trans, path, path->level + 1); 1959 1960 /* 1961 * Haven't gotten to the end of the parent node: go back down to 1962 * the next child node 1963 */ 1964 iter->path = bch2_btree_path_set_pos(trans, iter->path, 1965 bpos_successor(iter->pos), 1966 iter->flags & BTREE_ITER_intent, 1967 btree_iter_ip_allocated(iter)); 1968 1969 path = btree_iter_path(trans, iter); 1970 btree_path_set_level_down(trans, path, iter->min_depth); 1971 1972 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags); 1973 if (ret) 1974 goto err; 1975 1976 path = btree_iter_path(trans, iter); 1977 b = path->l[path->level].b; 1978 } 1979 1980 bkey_init(&iter->k); 1981 iter->k.p = iter->pos = b->key.k.p; 1982 1983 iter->path = bch2_btree_path_set_pos(trans, iter->path, b->key.k.p, 1984 iter->flags & BTREE_ITER_intent, 1985 btree_iter_ip_allocated(iter)); 1986 btree_path_set_should_be_locked(btree_iter_path(trans, iter)); 1987 EBUG_ON(btree_iter_path(trans, iter)->uptodate); 1988 out: 1989 bch2_btree_iter_verify_entry_exit(iter); 1990 bch2_btree_iter_verify(iter); 1991 1992 return b; 1993 err: 1994 b = ERR_PTR(ret); 1995 goto out; 1996 } 1997 1998 /* Iterate across keys (in leaf nodes only) */ 1999 2000 inline bool bch2_btree_iter_advance(struct btree_iter *iter) 2001 { 2002 struct bpos pos = iter->k.p; 2003 bool ret = !(iter->flags & BTREE_ITER_all_snapshots 2004 ? bpos_eq(pos, SPOS_MAX) 2005 : bkey_eq(pos, SPOS_MAX)); 2006 2007 if (ret && !(iter->flags & BTREE_ITER_is_extents)) 2008 pos = bkey_successor(iter, pos); 2009 bch2_btree_iter_set_pos(iter, pos); 2010 return ret; 2011 } 2012 2013 inline bool bch2_btree_iter_rewind(struct btree_iter *iter) 2014 { 2015 struct bpos pos = bkey_start_pos(&iter->k); 2016 bool ret = !(iter->flags & BTREE_ITER_all_snapshots 2017 ? bpos_eq(pos, POS_MIN) 2018 : bkey_eq(pos, POS_MIN)); 2019 2020 if (ret && !(iter->flags & BTREE_ITER_is_extents)) 2021 pos = bkey_predecessor(iter, pos); 2022 bch2_btree_iter_set_pos(iter, pos); 2023 return ret; 2024 } 2025 2026 static noinline 2027 void bch2_btree_trans_peek_prev_updates(struct btree_trans *trans, struct btree_iter *iter, 2028 struct bkey_s_c *k) 2029 { 2030 struct bpos end = path_l(btree_iter_path(trans, iter))->b->data->min_key; 2031 2032 trans_for_each_update(trans, i) 2033 if (!i->key_cache_already_flushed && 2034 i->btree_id == iter->btree_id && 2035 bpos_le(i->k->k.p, iter->pos) && 2036 bpos_ge(i->k->k.p, k->k ? k->k->p : end)) { 2037 iter->k = i->k->k; 2038 *k = bkey_i_to_s_c(i->k); 2039 } 2040 } 2041 2042 static noinline 2043 void bch2_btree_trans_peek_updates(struct btree_trans *trans, struct btree_iter *iter, 2044 struct bkey_s_c *k) 2045 { 2046 struct btree_path *path = btree_iter_path(trans, iter); 2047 struct bpos end = path_l(path)->b->key.k.p; 2048 2049 trans_for_each_update(trans, i) 2050 if (!i->key_cache_already_flushed && 2051 i->btree_id == iter->btree_id && 2052 bpos_ge(i->k->k.p, path->pos) && 2053 bpos_le(i->k->k.p, k->k ? k->k->p : end)) { 2054 iter->k = i->k->k; 2055 *k = bkey_i_to_s_c(i->k); 2056 } 2057 } 2058 2059 static noinline 2060 void bch2_btree_trans_peek_slot_updates(struct btree_trans *trans, struct btree_iter *iter, 2061 struct bkey_s_c *k) 2062 { 2063 trans_for_each_update(trans, i) 2064 if (!i->key_cache_already_flushed && 2065 i->btree_id == iter->btree_id && 2066 bpos_eq(i->k->k.p, iter->pos)) { 2067 iter->k = i->k->k; 2068 *k = bkey_i_to_s_c(i->k); 2069 } 2070 } 2071 2072 static struct bkey_i *bch2_btree_journal_peek(struct btree_trans *trans, 2073 struct btree_iter *iter, 2074 struct bpos end_pos) 2075 { 2076 struct btree_path *path = btree_iter_path(trans, iter); 2077 2078 return bch2_journal_keys_peek_upto(trans->c, iter->btree_id, 2079 path->level, 2080 path->pos, 2081 end_pos, 2082 &iter->journal_idx); 2083 } 2084 2085 static noinline 2086 struct bkey_s_c btree_trans_peek_slot_journal(struct btree_trans *trans, 2087 struct btree_iter *iter) 2088 { 2089 struct btree_path *path = btree_iter_path(trans, iter); 2090 struct bkey_i *k = bch2_btree_journal_peek(trans, iter, path->pos); 2091 2092 if (k) { 2093 iter->k = k->k; 2094 return bkey_i_to_s_c(k); 2095 } else { 2096 return bkey_s_c_null; 2097 } 2098 } 2099 2100 static noinline 2101 struct bkey_s_c btree_trans_peek_journal(struct btree_trans *trans, 2102 struct btree_iter *iter, 2103 struct bkey_s_c k) 2104 { 2105 struct btree_path *path = btree_iter_path(trans, iter); 2106 struct bkey_i *next_journal = 2107 bch2_btree_journal_peek(trans, iter, 2108 k.k ? k.k->p : path_l(path)->b->key.k.p); 2109 2110 if (next_journal) { 2111 iter->k = next_journal->k; 2112 k = bkey_i_to_s_c(next_journal); 2113 } 2114 2115 return k; 2116 } 2117 2118 /* 2119 * Checks btree key cache for key at iter->pos and returns it if present, or 2120 * bkey_s_c_null: 2121 */ 2122 static noinline 2123 struct bkey_s_c btree_trans_peek_key_cache(struct btree_iter *iter, struct bpos pos) 2124 { 2125 struct btree_trans *trans = iter->trans; 2126 struct bch_fs *c = trans->c; 2127 struct bkey u; 2128 struct bkey_s_c k; 2129 int ret; 2130 2131 bch2_trans_verify_not_in_restart(trans); 2132 bch2_trans_verify_not_unlocked(trans); 2133 2134 if ((iter->flags & BTREE_ITER_key_cache_fill) && 2135 bpos_eq(iter->pos, pos)) 2136 return bkey_s_c_null; 2137 2138 if (!bch2_btree_key_cache_find(c, iter->btree_id, pos)) 2139 return bkey_s_c_null; 2140 2141 if (!iter->key_cache_path) 2142 iter->key_cache_path = bch2_path_get(trans, iter->btree_id, pos, 2143 iter->flags & BTREE_ITER_intent, 0, 2144 iter->flags|BTREE_ITER_cached| 2145 BTREE_ITER_cached_nofill, 2146 _THIS_IP_); 2147 2148 iter->key_cache_path = bch2_btree_path_set_pos(trans, iter->key_cache_path, pos, 2149 iter->flags & BTREE_ITER_intent, 2150 btree_iter_ip_allocated(iter)); 2151 2152 ret = bch2_btree_path_traverse(trans, iter->key_cache_path, 2153 iter->flags|BTREE_ITER_cached) ?: 2154 bch2_btree_path_relock(trans, btree_iter_path(trans, iter), _THIS_IP_); 2155 if (unlikely(ret)) 2156 return bkey_s_c_err(ret); 2157 2158 btree_path_set_should_be_locked(trans->paths + iter->key_cache_path); 2159 2160 k = bch2_btree_path_peek_slot(trans->paths + iter->key_cache_path, &u); 2161 if (k.k && !bkey_err(k)) { 2162 iter->k = u; 2163 k.k = &iter->k; 2164 } 2165 return k; 2166 } 2167 2168 static struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter, struct bpos search_key) 2169 { 2170 struct btree_trans *trans = iter->trans; 2171 struct bkey_s_c k, k2; 2172 int ret; 2173 2174 EBUG_ON(btree_iter_path(trans, iter)->cached); 2175 bch2_btree_iter_verify(iter); 2176 2177 while (1) { 2178 struct btree_path_level *l; 2179 2180 iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key, 2181 iter->flags & BTREE_ITER_intent, 2182 btree_iter_ip_allocated(iter)); 2183 2184 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags); 2185 if (unlikely(ret)) { 2186 /* ensure that iter->k is consistent with iter->pos: */ 2187 bch2_btree_iter_set_pos(iter, iter->pos); 2188 k = bkey_s_c_err(ret); 2189 goto out; 2190 } 2191 2192 struct btree_path *path = btree_iter_path(trans, iter); 2193 l = path_l(path); 2194 2195 if (unlikely(!l->b)) { 2196 /* No btree nodes at requested level: */ 2197 bch2_btree_iter_set_pos(iter, SPOS_MAX); 2198 k = bkey_s_c_null; 2199 goto out; 2200 } 2201 2202 btree_path_set_should_be_locked(path); 2203 2204 k = btree_path_level_peek_all(trans->c, l, &iter->k); 2205 2206 if (unlikely(iter->flags & BTREE_ITER_with_key_cache) && 2207 k.k && 2208 (k2 = btree_trans_peek_key_cache(iter, k.k->p)).k) { 2209 k = k2; 2210 ret = bkey_err(k); 2211 if (ret) { 2212 bch2_btree_iter_set_pos(iter, iter->pos); 2213 goto out; 2214 } 2215 } 2216 2217 if (unlikely(iter->flags & BTREE_ITER_with_journal)) 2218 k = btree_trans_peek_journal(trans, iter, k); 2219 2220 if (unlikely((iter->flags & BTREE_ITER_with_updates) && 2221 trans->nr_updates)) 2222 bch2_btree_trans_peek_updates(trans, iter, &k); 2223 2224 if (k.k && bkey_deleted(k.k)) { 2225 /* 2226 * If we've got a whiteout, and it's after the search 2227 * key, advance the search key to the whiteout instead 2228 * of just after the whiteout - it might be a btree 2229 * whiteout, with a real key at the same position, since 2230 * in the btree deleted keys sort before non deleted. 2231 */ 2232 search_key = !bpos_eq(search_key, k.k->p) 2233 ? k.k->p 2234 : bpos_successor(k.k->p); 2235 continue; 2236 } 2237 2238 if (likely(k.k)) { 2239 break; 2240 } else if (likely(!bpos_eq(l->b->key.k.p, SPOS_MAX))) { 2241 /* Advance to next leaf node: */ 2242 search_key = bpos_successor(l->b->key.k.p); 2243 } else { 2244 /* End of btree: */ 2245 bch2_btree_iter_set_pos(iter, SPOS_MAX); 2246 k = bkey_s_c_null; 2247 goto out; 2248 } 2249 } 2250 out: 2251 bch2_btree_iter_verify(iter); 2252 2253 return k; 2254 } 2255 2256 /** 2257 * bch2_btree_iter_peek_upto() - returns first key greater than or equal to 2258 * iterator's current position 2259 * @iter: iterator to peek from 2260 * @end: search limit: returns keys less than or equal to @end 2261 * 2262 * Returns: key if found, or an error extractable with bkey_err(). 2263 */ 2264 struct bkey_s_c bch2_btree_iter_peek_upto(struct btree_iter *iter, struct bpos end) 2265 { 2266 struct btree_trans *trans = iter->trans; 2267 struct bpos search_key = btree_iter_search_key(iter); 2268 struct bkey_s_c k; 2269 struct bpos iter_pos; 2270 int ret; 2271 2272 bch2_trans_verify_not_unlocked(trans); 2273 EBUG_ON((iter->flags & BTREE_ITER_filter_snapshots) && bkey_eq(end, POS_MAX)); 2274 2275 if (iter->update_path) { 2276 bch2_path_put_nokeep(trans, iter->update_path, 2277 iter->flags & BTREE_ITER_intent); 2278 iter->update_path = 0; 2279 } 2280 2281 bch2_btree_iter_verify_entry_exit(iter); 2282 2283 while (1) { 2284 k = __bch2_btree_iter_peek(iter, search_key); 2285 if (unlikely(!k.k)) 2286 goto end; 2287 if (unlikely(bkey_err(k))) 2288 goto out_no_locked; 2289 2290 /* 2291 * We need to check against @end before FILTER_SNAPSHOTS because 2292 * if we get to a different inode that requested we might be 2293 * seeing keys for a different snapshot tree that will all be 2294 * filtered out. 2295 * 2296 * But we can't do the full check here, because bkey_start_pos() 2297 * isn't monotonically increasing before FILTER_SNAPSHOTS, and 2298 * that's what we check against in extents mode: 2299 */ 2300 if (unlikely(!(iter->flags & BTREE_ITER_is_extents) 2301 ? bkey_gt(k.k->p, end) 2302 : k.k->p.inode > end.inode)) 2303 goto end; 2304 2305 if (iter->update_path && 2306 !bkey_eq(trans->paths[iter->update_path].pos, k.k->p)) { 2307 bch2_path_put_nokeep(trans, iter->update_path, 2308 iter->flags & BTREE_ITER_intent); 2309 iter->update_path = 0; 2310 } 2311 2312 if ((iter->flags & BTREE_ITER_filter_snapshots) && 2313 (iter->flags & BTREE_ITER_intent) && 2314 !(iter->flags & BTREE_ITER_is_extents) && 2315 !iter->update_path) { 2316 struct bpos pos = k.k->p; 2317 2318 if (pos.snapshot < iter->snapshot) { 2319 search_key = bpos_successor(k.k->p); 2320 continue; 2321 } 2322 2323 pos.snapshot = iter->snapshot; 2324 2325 /* 2326 * advance, same as on exit for iter->path, but only up 2327 * to snapshot 2328 */ 2329 __btree_path_get(trans->paths + iter->path, iter->flags & BTREE_ITER_intent); 2330 iter->update_path = iter->path; 2331 2332 iter->update_path = bch2_btree_path_set_pos(trans, 2333 iter->update_path, pos, 2334 iter->flags & BTREE_ITER_intent, 2335 _THIS_IP_); 2336 ret = bch2_btree_path_traverse(trans, iter->update_path, iter->flags); 2337 if (unlikely(ret)) { 2338 k = bkey_s_c_err(ret); 2339 goto out_no_locked; 2340 } 2341 } 2342 2343 /* 2344 * We can never have a key in a leaf node at POS_MAX, so 2345 * we don't have to check these successor() calls: 2346 */ 2347 if ((iter->flags & BTREE_ITER_filter_snapshots) && 2348 !bch2_snapshot_is_ancestor(trans->c, 2349 iter->snapshot, 2350 k.k->p.snapshot)) { 2351 search_key = bpos_successor(k.k->p); 2352 continue; 2353 } 2354 2355 if (bkey_whiteout(k.k) && 2356 !(iter->flags & BTREE_ITER_all_snapshots)) { 2357 search_key = bkey_successor(iter, k.k->p); 2358 continue; 2359 } 2360 2361 /* 2362 * iter->pos should be mononotically increasing, and always be 2363 * equal to the key we just returned - except extents can 2364 * straddle iter->pos: 2365 */ 2366 if (!(iter->flags & BTREE_ITER_is_extents)) 2367 iter_pos = k.k->p; 2368 else 2369 iter_pos = bkey_max(iter->pos, bkey_start_pos(k.k)); 2370 2371 if (unlikely(!(iter->flags & BTREE_ITER_is_extents) 2372 ? bkey_gt(iter_pos, end) 2373 : bkey_ge(iter_pos, end))) 2374 goto end; 2375 2376 break; 2377 } 2378 2379 iter->pos = iter_pos; 2380 2381 iter->path = bch2_btree_path_set_pos(trans, iter->path, k.k->p, 2382 iter->flags & BTREE_ITER_intent, 2383 btree_iter_ip_allocated(iter)); 2384 2385 btree_path_set_should_be_locked(btree_iter_path(trans, iter)); 2386 out_no_locked: 2387 if (iter->update_path) { 2388 ret = bch2_btree_path_relock(trans, trans->paths + iter->update_path, _THIS_IP_); 2389 if (unlikely(ret)) 2390 k = bkey_s_c_err(ret); 2391 else 2392 btree_path_set_should_be_locked(trans->paths + iter->update_path); 2393 } 2394 2395 if (!(iter->flags & BTREE_ITER_all_snapshots)) 2396 iter->pos.snapshot = iter->snapshot; 2397 2398 ret = bch2_btree_iter_verify_ret(iter, k); 2399 if (unlikely(ret)) { 2400 bch2_btree_iter_set_pos(iter, iter->pos); 2401 k = bkey_s_c_err(ret); 2402 } 2403 2404 bch2_btree_iter_verify_entry_exit(iter); 2405 2406 return k; 2407 end: 2408 bch2_btree_iter_set_pos(iter, end); 2409 k = bkey_s_c_null; 2410 goto out_no_locked; 2411 } 2412 2413 /** 2414 * bch2_btree_iter_next() - returns first key greater than iterator's current 2415 * position 2416 * @iter: iterator to peek from 2417 * 2418 * Returns: key if found, or an error extractable with bkey_err(). 2419 */ 2420 struct bkey_s_c bch2_btree_iter_next(struct btree_iter *iter) 2421 { 2422 if (!bch2_btree_iter_advance(iter)) 2423 return bkey_s_c_null; 2424 2425 return bch2_btree_iter_peek(iter); 2426 } 2427 2428 /** 2429 * bch2_btree_iter_peek_prev() - returns first key less than or equal to 2430 * iterator's current position 2431 * @iter: iterator to peek from 2432 * 2433 * Returns: key if found, or an error extractable with bkey_err(). 2434 */ 2435 struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *iter) 2436 { 2437 struct btree_trans *trans = iter->trans; 2438 struct bpos search_key = iter->pos; 2439 struct bkey_s_c k; 2440 struct bkey saved_k; 2441 const struct bch_val *saved_v; 2442 btree_path_idx_t saved_path = 0; 2443 int ret; 2444 2445 bch2_trans_verify_not_unlocked(trans); 2446 EBUG_ON(btree_iter_path(trans, iter)->cached || 2447 btree_iter_path(trans, iter)->level); 2448 2449 if (iter->flags & BTREE_ITER_with_journal) 2450 return bkey_s_c_err(-BCH_ERR_btree_iter_with_journal_not_supported); 2451 2452 bch2_btree_iter_verify(iter); 2453 bch2_btree_iter_verify_entry_exit(iter); 2454 2455 if (iter->flags & BTREE_ITER_filter_snapshots) 2456 search_key.snapshot = U32_MAX; 2457 2458 while (1) { 2459 iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key, 2460 iter->flags & BTREE_ITER_intent, 2461 btree_iter_ip_allocated(iter)); 2462 2463 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags); 2464 if (unlikely(ret)) { 2465 /* ensure that iter->k is consistent with iter->pos: */ 2466 bch2_btree_iter_set_pos(iter, iter->pos); 2467 k = bkey_s_c_err(ret); 2468 goto out_no_locked; 2469 } 2470 2471 struct btree_path *path = btree_iter_path(trans, iter); 2472 2473 k = btree_path_level_peek(trans, path, &path->l[0], &iter->k); 2474 if (!k.k || 2475 ((iter->flags & BTREE_ITER_is_extents) 2476 ? bpos_ge(bkey_start_pos(k.k), search_key) 2477 : bpos_gt(k.k->p, search_key))) 2478 k = btree_path_level_prev(trans, path, &path->l[0], &iter->k); 2479 2480 if (unlikely((iter->flags & BTREE_ITER_with_updates) && 2481 trans->nr_updates)) 2482 bch2_btree_trans_peek_prev_updates(trans, iter, &k); 2483 2484 if (likely(k.k)) { 2485 if (iter->flags & BTREE_ITER_filter_snapshots) { 2486 if (k.k->p.snapshot == iter->snapshot) 2487 goto got_key; 2488 2489 /* 2490 * If we have a saved candidate, and we're no 2491 * longer at the same _key_ (not pos), return 2492 * that candidate 2493 */ 2494 if (saved_path && !bkey_eq(k.k->p, saved_k.p)) { 2495 bch2_path_put_nokeep(trans, iter->path, 2496 iter->flags & BTREE_ITER_intent); 2497 iter->path = saved_path; 2498 saved_path = 0; 2499 iter->k = saved_k; 2500 k.v = saved_v; 2501 goto got_key; 2502 } 2503 2504 if (bch2_snapshot_is_ancestor(trans->c, 2505 iter->snapshot, 2506 k.k->p.snapshot)) { 2507 if (saved_path) 2508 bch2_path_put_nokeep(trans, saved_path, 2509 iter->flags & BTREE_ITER_intent); 2510 saved_path = btree_path_clone(trans, iter->path, 2511 iter->flags & BTREE_ITER_intent, 2512 _THIS_IP_); 2513 path = btree_iter_path(trans, iter); 2514 saved_k = *k.k; 2515 saved_v = k.v; 2516 } 2517 2518 search_key = bpos_predecessor(k.k->p); 2519 continue; 2520 } 2521 got_key: 2522 if (bkey_whiteout(k.k) && 2523 !(iter->flags & BTREE_ITER_all_snapshots)) { 2524 search_key = bkey_predecessor(iter, k.k->p); 2525 if (iter->flags & BTREE_ITER_filter_snapshots) 2526 search_key.snapshot = U32_MAX; 2527 continue; 2528 } 2529 2530 btree_path_set_should_be_locked(path); 2531 break; 2532 } else if (likely(!bpos_eq(path->l[0].b->data->min_key, POS_MIN))) { 2533 /* Advance to previous leaf node: */ 2534 search_key = bpos_predecessor(path->l[0].b->data->min_key); 2535 } else { 2536 /* Start of btree: */ 2537 bch2_btree_iter_set_pos(iter, POS_MIN); 2538 k = bkey_s_c_null; 2539 goto out_no_locked; 2540 } 2541 } 2542 2543 EBUG_ON(bkey_gt(bkey_start_pos(k.k), iter->pos)); 2544 2545 /* Extents can straddle iter->pos: */ 2546 if (bkey_lt(k.k->p, iter->pos)) 2547 iter->pos = k.k->p; 2548 2549 if (iter->flags & BTREE_ITER_filter_snapshots) 2550 iter->pos.snapshot = iter->snapshot; 2551 out_no_locked: 2552 if (saved_path) 2553 bch2_path_put_nokeep(trans, saved_path, iter->flags & BTREE_ITER_intent); 2554 2555 bch2_btree_iter_verify_entry_exit(iter); 2556 bch2_btree_iter_verify(iter); 2557 2558 return k; 2559 } 2560 2561 /** 2562 * bch2_btree_iter_prev() - returns first key less than iterator's current 2563 * position 2564 * @iter: iterator to peek from 2565 * 2566 * Returns: key if found, or an error extractable with bkey_err(). 2567 */ 2568 struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *iter) 2569 { 2570 if (!bch2_btree_iter_rewind(iter)) 2571 return bkey_s_c_null; 2572 2573 return bch2_btree_iter_peek_prev(iter); 2574 } 2575 2576 struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *iter) 2577 { 2578 struct btree_trans *trans = iter->trans; 2579 struct bpos search_key; 2580 struct bkey_s_c k; 2581 int ret; 2582 2583 bch2_trans_verify_not_unlocked(trans); 2584 bch2_btree_iter_verify(iter); 2585 bch2_btree_iter_verify_entry_exit(iter); 2586 EBUG_ON(btree_iter_path(trans, iter)->level && (iter->flags & BTREE_ITER_with_key_cache)); 2587 2588 /* extents can't span inode numbers: */ 2589 if ((iter->flags & BTREE_ITER_is_extents) && 2590 unlikely(iter->pos.offset == KEY_OFFSET_MAX)) { 2591 if (iter->pos.inode == KEY_INODE_MAX) 2592 return bkey_s_c_null; 2593 2594 bch2_btree_iter_set_pos(iter, bpos_nosnap_successor(iter->pos)); 2595 } 2596 2597 search_key = btree_iter_search_key(iter); 2598 iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key, 2599 iter->flags & BTREE_ITER_intent, 2600 btree_iter_ip_allocated(iter)); 2601 2602 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags); 2603 if (unlikely(ret)) { 2604 k = bkey_s_c_err(ret); 2605 goto out_no_locked; 2606 } 2607 2608 if ((iter->flags & BTREE_ITER_cached) || 2609 !(iter->flags & (BTREE_ITER_is_extents|BTREE_ITER_filter_snapshots))) { 2610 k = bkey_s_c_null; 2611 2612 if (unlikely((iter->flags & BTREE_ITER_with_updates) && 2613 trans->nr_updates)) { 2614 bch2_btree_trans_peek_slot_updates(trans, iter, &k); 2615 if (k.k) 2616 goto out; 2617 } 2618 2619 if (unlikely(iter->flags & BTREE_ITER_with_journal) && 2620 (k = btree_trans_peek_slot_journal(trans, iter)).k) 2621 goto out; 2622 2623 if (unlikely(iter->flags & BTREE_ITER_with_key_cache) && 2624 (k = btree_trans_peek_key_cache(iter, iter->pos)).k) { 2625 if (!bkey_err(k)) 2626 iter->k = *k.k; 2627 /* We're not returning a key from iter->path: */ 2628 goto out_no_locked; 2629 } 2630 2631 k = bch2_btree_path_peek_slot(trans->paths + iter->path, &iter->k); 2632 if (unlikely(!k.k)) 2633 goto out_no_locked; 2634 } else { 2635 struct bpos next; 2636 struct bpos end = iter->pos; 2637 2638 if (iter->flags & BTREE_ITER_is_extents) 2639 end.offset = U64_MAX; 2640 2641 EBUG_ON(btree_iter_path(trans, iter)->level); 2642 2643 if (iter->flags & BTREE_ITER_intent) { 2644 struct btree_iter iter2; 2645 2646 bch2_trans_copy_iter(&iter2, iter); 2647 k = bch2_btree_iter_peek_upto(&iter2, end); 2648 2649 if (k.k && !bkey_err(k)) { 2650 swap(iter->key_cache_path, iter2.key_cache_path); 2651 iter->k = iter2.k; 2652 k.k = &iter->k; 2653 } 2654 bch2_trans_iter_exit(trans, &iter2); 2655 } else { 2656 struct bpos pos = iter->pos; 2657 2658 k = bch2_btree_iter_peek_upto(iter, end); 2659 if (unlikely(bkey_err(k))) 2660 bch2_btree_iter_set_pos(iter, pos); 2661 else 2662 iter->pos = pos; 2663 } 2664 2665 if (unlikely(bkey_err(k))) 2666 goto out_no_locked; 2667 2668 next = k.k ? bkey_start_pos(k.k) : POS_MAX; 2669 2670 if (bkey_lt(iter->pos, next)) { 2671 bkey_init(&iter->k); 2672 iter->k.p = iter->pos; 2673 2674 if (iter->flags & BTREE_ITER_is_extents) { 2675 bch2_key_resize(&iter->k, 2676 min_t(u64, KEY_SIZE_MAX, 2677 (next.inode == iter->pos.inode 2678 ? next.offset 2679 : KEY_OFFSET_MAX) - 2680 iter->pos.offset)); 2681 EBUG_ON(!iter->k.size); 2682 } 2683 2684 k = (struct bkey_s_c) { &iter->k, NULL }; 2685 } 2686 } 2687 out: 2688 btree_path_set_should_be_locked(btree_iter_path(trans, iter)); 2689 out_no_locked: 2690 bch2_btree_iter_verify_entry_exit(iter); 2691 bch2_btree_iter_verify(iter); 2692 ret = bch2_btree_iter_verify_ret(iter, k); 2693 if (unlikely(ret)) 2694 return bkey_s_c_err(ret); 2695 2696 return k; 2697 } 2698 2699 struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *iter) 2700 { 2701 if (!bch2_btree_iter_advance(iter)) 2702 return bkey_s_c_null; 2703 2704 return bch2_btree_iter_peek_slot(iter); 2705 } 2706 2707 struct bkey_s_c bch2_btree_iter_prev_slot(struct btree_iter *iter) 2708 { 2709 if (!bch2_btree_iter_rewind(iter)) 2710 return bkey_s_c_null; 2711 2712 return bch2_btree_iter_peek_slot(iter); 2713 } 2714 2715 struct bkey_s_c bch2_btree_iter_peek_and_restart_outlined(struct btree_iter *iter) 2716 { 2717 struct bkey_s_c k; 2718 2719 while (btree_trans_too_many_iters(iter->trans) || 2720 (k = bch2_btree_iter_peek_type(iter, iter->flags), 2721 bch2_err_matches(bkey_err(k), BCH_ERR_transaction_restart))) 2722 bch2_trans_begin(iter->trans); 2723 2724 return k; 2725 } 2726 2727 /* new transactional stuff: */ 2728 2729 #ifdef CONFIG_BCACHEFS_DEBUG 2730 static void btree_trans_verify_sorted_refs(struct btree_trans *trans) 2731 { 2732 struct btree_path *path; 2733 unsigned i; 2734 2735 BUG_ON(trans->nr_sorted != bitmap_weight(trans->paths_allocated, trans->nr_paths) - 1); 2736 2737 trans_for_each_path(trans, path, i) { 2738 BUG_ON(path->sorted_idx >= trans->nr_sorted); 2739 BUG_ON(trans->sorted[path->sorted_idx] != i); 2740 } 2741 2742 for (i = 0; i < trans->nr_sorted; i++) { 2743 unsigned idx = trans->sorted[i]; 2744 2745 BUG_ON(!test_bit(idx, trans->paths_allocated)); 2746 BUG_ON(trans->paths[idx].sorted_idx != i); 2747 } 2748 } 2749 2750 static void btree_trans_verify_sorted(struct btree_trans *trans) 2751 { 2752 struct btree_path *path, *prev = NULL; 2753 struct trans_for_each_path_inorder_iter iter; 2754 2755 if (!bch2_debug_check_iterators) 2756 return; 2757 2758 trans_for_each_path_inorder(trans, path, iter) { 2759 if (prev && btree_path_cmp(prev, path) > 0) { 2760 __bch2_dump_trans_paths_updates(trans, true); 2761 panic("trans paths out of order!\n"); 2762 } 2763 prev = path; 2764 } 2765 } 2766 #else 2767 static inline void btree_trans_verify_sorted_refs(struct btree_trans *trans) {} 2768 static inline void btree_trans_verify_sorted(struct btree_trans *trans) {} 2769 #endif 2770 2771 void __bch2_btree_trans_sort_paths(struct btree_trans *trans) 2772 { 2773 int i, l = 0, r = trans->nr_sorted, inc = 1; 2774 bool swapped; 2775 2776 btree_trans_verify_sorted_refs(trans); 2777 2778 if (trans->paths_sorted) 2779 goto out; 2780 2781 /* 2782 * Cocktail shaker sort: this is efficient because iterators will be 2783 * mostly sorted. 2784 */ 2785 do { 2786 swapped = false; 2787 2788 for (i = inc > 0 ? l : r - 2; 2789 i + 1 < r && i >= l; 2790 i += inc) { 2791 if (btree_path_cmp(trans->paths + trans->sorted[i], 2792 trans->paths + trans->sorted[i + 1]) > 0) { 2793 swap(trans->sorted[i], trans->sorted[i + 1]); 2794 trans->paths[trans->sorted[i]].sorted_idx = i; 2795 trans->paths[trans->sorted[i + 1]].sorted_idx = i + 1; 2796 swapped = true; 2797 } 2798 } 2799 2800 if (inc > 0) 2801 --r; 2802 else 2803 l++; 2804 inc = -inc; 2805 } while (swapped); 2806 2807 trans->paths_sorted = true; 2808 out: 2809 btree_trans_verify_sorted(trans); 2810 } 2811 2812 static inline void btree_path_list_remove(struct btree_trans *trans, 2813 struct btree_path *path) 2814 { 2815 EBUG_ON(path->sorted_idx >= trans->nr_sorted); 2816 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 2817 trans->nr_sorted--; 2818 memmove_u64s_down_small(trans->sorted + path->sorted_idx, 2819 trans->sorted + path->sorted_idx + 1, 2820 DIV_ROUND_UP(trans->nr_sorted - path->sorted_idx, 2821 sizeof(u64) / sizeof(btree_path_idx_t))); 2822 #else 2823 array_remove_item(trans->sorted, trans->nr_sorted, path->sorted_idx); 2824 #endif 2825 for (unsigned i = path->sorted_idx; i < trans->nr_sorted; i++) 2826 trans->paths[trans->sorted[i]].sorted_idx = i; 2827 } 2828 2829 static inline void btree_path_list_add(struct btree_trans *trans, 2830 btree_path_idx_t pos, 2831 btree_path_idx_t path_idx) 2832 { 2833 struct btree_path *path = trans->paths + path_idx; 2834 2835 path->sorted_idx = pos ? trans->paths[pos].sorted_idx + 1 : trans->nr_sorted; 2836 2837 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 2838 memmove_u64s_up_small(trans->sorted + path->sorted_idx + 1, 2839 trans->sorted + path->sorted_idx, 2840 DIV_ROUND_UP(trans->nr_sorted - path->sorted_idx, 2841 sizeof(u64) / sizeof(btree_path_idx_t))); 2842 trans->nr_sorted++; 2843 trans->sorted[path->sorted_idx] = path_idx; 2844 #else 2845 array_insert_item(trans->sorted, trans->nr_sorted, path->sorted_idx, path_idx); 2846 #endif 2847 2848 for (unsigned i = path->sorted_idx; i < trans->nr_sorted; i++) 2849 trans->paths[trans->sorted[i]].sorted_idx = i; 2850 2851 btree_trans_verify_sorted_refs(trans); 2852 } 2853 2854 void bch2_trans_iter_exit(struct btree_trans *trans, struct btree_iter *iter) 2855 { 2856 if (iter->update_path) 2857 bch2_path_put_nokeep(trans, iter->update_path, 2858 iter->flags & BTREE_ITER_intent); 2859 if (iter->path) 2860 bch2_path_put(trans, iter->path, 2861 iter->flags & BTREE_ITER_intent); 2862 if (iter->key_cache_path) 2863 bch2_path_put(trans, iter->key_cache_path, 2864 iter->flags & BTREE_ITER_intent); 2865 iter->path = 0; 2866 iter->update_path = 0; 2867 iter->key_cache_path = 0; 2868 iter->trans = NULL; 2869 } 2870 2871 void bch2_trans_iter_init_outlined(struct btree_trans *trans, 2872 struct btree_iter *iter, 2873 enum btree_id btree_id, struct bpos pos, 2874 unsigned flags) 2875 { 2876 bch2_trans_iter_init_common(trans, iter, btree_id, pos, 0, 0, 2877 bch2_btree_iter_flags(trans, btree_id, flags), 2878 _RET_IP_); 2879 } 2880 2881 void bch2_trans_node_iter_init(struct btree_trans *trans, 2882 struct btree_iter *iter, 2883 enum btree_id btree_id, 2884 struct bpos pos, 2885 unsigned locks_want, 2886 unsigned depth, 2887 unsigned flags) 2888 { 2889 flags |= BTREE_ITER_not_extents; 2890 flags |= BTREE_ITER_snapshot_field; 2891 flags |= BTREE_ITER_all_snapshots; 2892 2893 bch2_trans_iter_init_common(trans, iter, btree_id, pos, locks_want, depth, 2894 __bch2_btree_iter_flags(trans, btree_id, flags), 2895 _RET_IP_); 2896 2897 iter->min_depth = depth; 2898 2899 struct btree_path *path = btree_iter_path(trans, iter); 2900 BUG_ON(path->locks_want < min(locks_want, BTREE_MAX_DEPTH)); 2901 BUG_ON(path->level != depth); 2902 BUG_ON(iter->min_depth != depth); 2903 } 2904 2905 void bch2_trans_copy_iter(struct btree_iter *dst, struct btree_iter *src) 2906 { 2907 struct btree_trans *trans = src->trans; 2908 2909 *dst = *src; 2910 #ifdef TRACK_PATH_ALLOCATED 2911 dst->ip_allocated = _RET_IP_; 2912 #endif 2913 if (src->path) 2914 __btree_path_get(trans->paths + src->path, src->flags & BTREE_ITER_intent); 2915 if (src->update_path) 2916 __btree_path_get(trans->paths + src->update_path, src->flags & BTREE_ITER_intent); 2917 dst->key_cache_path = 0; 2918 } 2919 2920 void *__bch2_trans_kmalloc(struct btree_trans *trans, size_t size) 2921 { 2922 struct bch_fs *c = trans->c; 2923 unsigned new_top = trans->mem_top + size; 2924 unsigned old_bytes = trans->mem_bytes; 2925 unsigned new_bytes = roundup_pow_of_two(new_top); 2926 int ret; 2927 void *new_mem; 2928 void *p; 2929 2930 WARN_ON_ONCE(new_bytes > BTREE_TRANS_MEM_MAX); 2931 2932 struct btree_transaction_stats *s = btree_trans_stats(trans); 2933 s->max_mem = max(s->max_mem, new_bytes); 2934 2935 if (trans->used_mempool) { 2936 if (trans->mem_bytes >= new_bytes) 2937 goto out_change_top; 2938 2939 /* No more space from mempool item, need malloc new one */ 2940 new_mem = kmalloc(new_bytes, GFP_NOWAIT|__GFP_NOWARN); 2941 if (unlikely(!new_mem)) { 2942 bch2_trans_unlock(trans); 2943 2944 new_mem = kmalloc(new_bytes, GFP_KERNEL); 2945 if (!new_mem) 2946 return ERR_PTR(-BCH_ERR_ENOMEM_trans_kmalloc); 2947 2948 ret = bch2_trans_relock(trans); 2949 if (ret) { 2950 kfree(new_mem); 2951 return ERR_PTR(ret); 2952 } 2953 } 2954 memcpy(new_mem, trans->mem, trans->mem_top); 2955 trans->used_mempool = false; 2956 mempool_free(trans->mem, &c->btree_trans_mem_pool); 2957 goto out_new_mem; 2958 } 2959 2960 new_mem = krealloc(trans->mem, new_bytes, GFP_NOWAIT|__GFP_NOWARN); 2961 if (unlikely(!new_mem)) { 2962 bch2_trans_unlock(trans); 2963 2964 new_mem = krealloc(trans->mem, new_bytes, GFP_KERNEL); 2965 if (!new_mem && new_bytes <= BTREE_TRANS_MEM_MAX) { 2966 new_mem = mempool_alloc(&c->btree_trans_mem_pool, GFP_KERNEL); 2967 new_bytes = BTREE_TRANS_MEM_MAX; 2968 memcpy(new_mem, trans->mem, trans->mem_top); 2969 trans->used_mempool = true; 2970 kfree(trans->mem); 2971 } 2972 2973 if (!new_mem) 2974 return ERR_PTR(-BCH_ERR_ENOMEM_trans_kmalloc); 2975 2976 trans->mem = new_mem; 2977 trans->mem_bytes = new_bytes; 2978 2979 ret = bch2_trans_relock(trans); 2980 if (ret) 2981 return ERR_PTR(ret); 2982 } 2983 out_new_mem: 2984 trans->mem = new_mem; 2985 trans->mem_bytes = new_bytes; 2986 2987 if (old_bytes) { 2988 trace_and_count(c, trans_restart_mem_realloced, trans, _RET_IP_, new_bytes); 2989 return ERR_PTR(btree_trans_restart(trans, BCH_ERR_transaction_restart_mem_realloced)); 2990 } 2991 out_change_top: 2992 p = trans->mem + trans->mem_top; 2993 trans->mem_top += size; 2994 memset(p, 0, size); 2995 return p; 2996 } 2997 2998 static inline void check_srcu_held_too_long(struct btree_trans *trans) 2999 { 3000 WARN(trans->srcu_held && time_after(jiffies, trans->srcu_lock_time + HZ * 10), 3001 "btree trans held srcu lock (delaying memory reclaim) for %lu seconds", 3002 (jiffies - trans->srcu_lock_time) / HZ); 3003 } 3004 3005 void bch2_trans_srcu_unlock(struct btree_trans *trans) 3006 { 3007 if (trans->srcu_held) { 3008 struct bch_fs *c = trans->c; 3009 struct btree_path *path; 3010 unsigned i; 3011 3012 trans_for_each_path(trans, path, i) 3013 if (path->cached && !btree_node_locked(path, 0)) 3014 path->l[0].b = ERR_PTR(-BCH_ERR_no_btree_node_srcu_reset); 3015 3016 check_srcu_held_too_long(trans); 3017 srcu_read_unlock(&c->btree_trans_barrier, trans->srcu_idx); 3018 trans->srcu_held = false; 3019 } 3020 } 3021 3022 static void bch2_trans_srcu_lock(struct btree_trans *trans) 3023 { 3024 if (!trans->srcu_held) { 3025 trans->srcu_idx = srcu_read_lock(&trans->c->btree_trans_barrier); 3026 trans->srcu_lock_time = jiffies; 3027 trans->srcu_held = true; 3028 } 3029 } 3030 3031 /** 3032 * bch2_trans_begin() - reset a transaction after a interrupted attempt 3033 * @trans: transaction to reset 3034 * 3035 * Returns: current restart counter, to be used with trans_was_restarted() 3036 * 3037 * While iterating over nodes or updating nodes a attempt to lock a btree node 3038 * may return BCH_ERR_transaction_restart when the trylock fails. When this 3039 * occurs bch2_trans_begin() should be called and the transaction retried. 3040 */ 3041 u32 bch2_trans_begin(struct btree_trans *trans) 3042 { 3043 struct btree_path *path; 3044 unsigned i; 3045 u64 now; 3046 3047 bch2_trans_reset_updates(trans); 3048 3049 trans->restart_count++; 3050 trans->mem_top = 0; 3051 trans->journal_entries = NULL; 3052 3053 trans_for_each_path(trans, path, i) { 3054 path->should_be_locked = false; 3055 3056 /* 3057 * If the transaction wasn't restarted, we're presuming to be 3058 * doing something new: dont keep iterators excpt the ones that 3059 * are in use - except for the subvolumes btree: 3060 */ 3061 if (!trans->restarted && path->btree_id != BTREE_ID_subvolumes) 3062 path->preserve = false; 3063 3064 /* 3065 * XXX: we probably shouldn't be doing this if the transaction 3066 * was restarted, but currently we still overflow transaction 3067 * iterators if we do that 3068 */ 3069 if (!path->ref && !path->preserve) 3070 __bch2_path_free(trans, i); 3071 else 3072 path->preserve = false; 3073 } 3074 3075 now = local_clock(); 3076 3077 if (!IS_ENABLED(CONFIG_BCACHEFS_NO_LATENCY_ACCT) && 3078 time_after64(now, trans->last_begin_time + 10)) 3079 __bch2_time_stats_update(&btree_trans_stats(trans)->duration, 3080 trans->last_begin_time, now); 3081 3082 if (!trans->restarted && 3083 (need_resched() || 3084 time_after64(now, trans->last_begin_time + BTREE_TRANS_MAX_LOCK_HOLD_TIME_NS))) { 3085 bch2_trans_unlock(trans); 3086 cond_resched(); 3087 now = local_clock(); 3088 } 3089 trans->last_begin_time = now; 3090 3091 if (unlikely(trans->srcu_held && 3092 time_after(jiffies, trans->srcu_lock_time + msecs_to_jiffies(10)))) 3093 bch2_trans_srcu_unlock(trans); 3094 3095 trans->last_begin_ip = _RET_IP_; 3096 3097 trans_set_locked(trans); 3098 3099 if (trans->restarted) { 3100 bch2_btree_path_traverse_all(trans); 3101 trans->notrace_relock_fail = false; 3102 } 3103 3104 bch2_trans_verify_not_unlocked(trans); 3105 return trans->restart_count; 3106 } 3107 3108 const char *bch2_btree_transaction_fns[BCH_TRANSACTIONS_NR] = { "(unknown)" }; 3109 3110 unsigned bch2_trans_get_fn_idx(const char *fn) 3111 { 3112 for (unsigned i = 0; i < ARRAY_SIZE(bch2_btree_transaction_fns); i++) 3113 if (!bch2_btree_transaction_fns[i] || 3114 bch2_btree_transaction_fns[i] == fn) { 3115 bch2_btree_transaction_fns[i] = fn; 3116 return i; 3117 } 3118 3119 pr_warn_once("BCH_TRANSACTIONS_NR not big enough!"); 3120 return 0; 3121 } 3122 3123 struct btree_trans *__bch2_trans_get(struct bch_fs *c, unsigned fn_idx) 3124 __acquires(&c->btree_trans_barrier) 3125 { 3126 struct btree_trans *trans; 3127 3128 if (IS_ENABLED(__KERNEL__)) { 3129 trans = this_cpu_xchg(c->btree_trans_bufs->trans, NULL); 3130 if (trans) { 3131 memset(trans, 0, offsetof(struct btree_trans, list)); 3132 goto got_trans; 3133 } 3134 } 3135 3136 trans = mempool_alloc(&c->btree_trans_pool, GFP_NOFS); 3137 memset(trans, 0, sizeof(*trans)); 3138 3139 seqmutex_lock(&c->btree_trans_lock); 3140 if (IS_ENABLED(CONFIG_BCACHEFS_DEBUG)) { 3141 struct btree_trans *pos; 3142 pid_t pid = current->pid; 3143 3144 trans->locking_wait.task = current; 3145 3146 list_for_each_entry(pos, &c->btree_trans_list, list) { 3147 struct task_struct *pos_task = READ_ONCE(pos->locking_wait.task); 3148 /* 3149 * We'd much prefer to be stricter here and completely 3150 * disallow multiple btree_trans in the same thread - 3151 * but the data move path calls bch2_write when we 3152 * already have a btree_trans initialized. 3153 */ 3154 BUG_ON(pos_task && 3155 pid == pos_task->pid && 3156 pos->locked); 3157 } 3158 } 3159 3160 list_add(&trans->list, &c->btree_trans_list); 3161 seqmutex_unlock(&c->btree_trans_lock); 3162 got_trans: 3163 trans->c = c; 3164 trans->last_begin_time = local_clock(); 3165 trans->fn_idx = fn_idx; 3166 trans->locking_wait.task = current; 3167 trans->journal_replay_not_finished = 3168 unlikely(!test_bit(JOURNAL_replay_done, &c->journal.flags)) && 3169 atomic_inc_not_zero(&c->journal_keys.ref); 3170 trans->nr_paths = ARRAY_SIZE(trans->_paths); 3171 trans->paths_allocated = trans->_paths_allocated; 3172 trans->sorted = trans->_sorted; 3173 trans->paths = trans->_paths; 3174 trans->updates = trans->_updates; 3175 3176 *trans_paths_nr(trans->paths) = BTREE_ITER_INITIAL; 3177 3178 trans->paths_allocated[0] = 1; 3179 3180 static struct lock_class_key lockdep_key; 3181 lockdep_init_map(&trans->dep_map, "bcachefs_btree", &lockdep_key, 0); 3182 3183 if (fn_idx < BCH_TRANSACTIONS_NR) { 3184 trans->fn = bch2_btree_transaction_fns[fn_idx]; 3185 3186 struct btree_transaction_stats *s = &c->btree_transaction_stats[fn_idx]; 3187 3188 if (s->max_mem) { 3189 unsigned expected_mem_bytes = roundup_pow_of_two(s->max_mem); 3190 3191 trans->mem = kmalloc(expected_mem_bytes, GFP_KERNEL); 3192 if (likely(trans->mem)) 3193 trans->mem_bytes = expected_mem_bytes; 3194 } 3195 3196 trans->nr_paths_max = s->nr_max_paths; 3197 trans->journal_entries_size = s->journal_entries_size; 3198 } 3199 3200 trans->srcu_idx = srcu_read_lock(&c->btree_trans_barrier); 3201 trans->srcu_lock_time = jiffies; 3202 trans->srcu_held = true; 3203 trans_set_locked(trans); 3204 3205 closure_init_stack_release(&trans->ref); 3206 return trans; 3207 } 3208 3209 static void check_btree_paths_leaked(struct btree_trans *trans) 3210 { 3211 #ifdef CONFIG_BCACHEFS_DEBUG 3212 struct bch_fs *c = trans->c; 3213 struct btree_path *path; 3214 unsigned i; 3215 3216 trans_for_each_path(trans, path, i) 3217 if (path->ref) 3218 goto leaked; 3219 return; 3220 leaked: 3221 bch_err(c, "btree paths leaked from %s!", trans->fn); 3222 trans_for_each_path(trans, path, i) 3223 if (path->ref) 3224 printk(KERN_ERR " btree %s %pS\n", 3225 bch2_btree_id_str(path->btree_id), 3226 (void *) path->ip_allocated); 3227 /* Be noisy about this: */ 3228 bch2_fatal_error(c); 3229 #endif 3230 } 3231 3232 void bch2_trans_put(struct btree_trans *trans) 3233 __releases(&c->btree_trans_barrier) 3234 { 3235 struct bch_fs *c = trans->c; 3236 3237 bch2_trans_unlock(trans); 3238 3239 trans_for_each_update(trans, i) 3240 __btree_path_put(trans->paths + i->path, true); 3241 trans->nr_updates = 0; 3242 3243 check_btree_paths_leaked(trans); 3244 3245 if (trans->srcu_held) { 3246 check_srcu_held_too_long(trans); 3247 srcu_read_unlock(&c->btree_trans_barrier, trans->srcu_idx); 3248 } 3249 3250 if (unlikely(trans->journal_replay_not_finished)) 3251 bch2_journal_keys_put(c); 3252 3253 /* 3254 * trans->ref protects trans->locking_wait.task, btree_paths array; used 3255 * by cycle detector 3256 */ 3257 closure_return_sync(&trans->ref); 3258 trans->locking_wait.task = NULL; 3259 3260 unsigned long *paths_allocated = trans->paths_allocated; 3261 trans->paths_allocated = NULL; 3262 trans->paths = NULL; 3263 3264 if (paths_allocated != trans->_paths_allocated) 3265 kvfree_rcu_mightsleep(paths_allocated); 3266 3267 if (trans->used_mempool) 3268 mempool_free(trans->mem, &c->btree_trans_mem_pool); 3269 else 3270 kfree(trans->mem); 3271 3272 /* Userspace doesn't have a real percpu implementation: */ 3273 if (IS_ENABLED(__KERNEL__)) 3274 trans = this_cpu_xchg(c->btree_trans_bufs->trans, trans); 3275 3276 if (trans) { 3277 seqmutex_lock(&c->btree_trans_lock); 3278 list_del(&trans->list); 3279 seqmutex_unlock(&c->btree_trans_lock); 3280 3281 mempool_free(trans, &c->btree_trans_pool); 3282 } 3283 } 3284 3285 bool bch2_current_has_btree_trans(struct bch_fs *c) 3286 { 3287 seqmutex_lock(&c->btree_trans_lock); 3288 struct btree_trans *trans; 3289 bool ret = false; 3290 list_for_each_entry(trans, &c->btree_trans_list, list) 3291 if (trans->locking_wait.task == current && 3292 trans->locked) { 3293 ret = true; 3294 break; 3295 } 3296 seqmutex_unlock(&c->btree_trans_lock); 3297 return ret; 3298 } 3299 3300 static void __maybe_unused 3301 bch2_btree_bkey_cached_common_to_text(struct printbuf *out, 3302 struct btree_bkey_cached_common *b) 3303 { 3304 struct six_lock_count c = six_lock_counts(&b->lock); 3305 struct task_struct *owner; 3306 pid_t pid; 3307 3308 rcu_read_lock(); 3309 owner = READ_ONCE(b->lock.owner); 3310 pid = owner ? owner->pid : 0; 3311 rcu_read_unlock(); 3312 3313 prt_printf(out, "\t%px %c l=%u %s:", b, b->cached ? 'c' : 'b', 3314 b->level, bch2_btree_id_str(b->btree_id)); 3315 bch2_bpos_to_text(out, btree_node_pos(b)); 3316 3317 prt_printf(out, "\t locks %u:%u:%u held by pid %u", 3318 c.n[0], c.n[1], c.n[2], pid); 3319 } 3320 3321 void bch2_btree_trans_to_text(struct printbuf *out, struct btree_trans *trans) 3322 { 3323 struct btree_bkey_cached_common *b; 3324 static char lock_types[] = { 'r', 'i', 'w' }; 3325 struct task_struct *task = READ_ONCE(trans->locking_wait.task); 3326 unsigned l, idx; 3327 3328 /* before rcu_read_lock(): */ 3329 bch2_printbuf_make_room(out, 4096); 3330 3331 if (!out->nr_tabstops) { 3332 printbuf_tabstop_push(out, 16); 3333 printbuf_tabstop_push(out, 32); 3334 } 3335 3336 prt_printf(out, "%i %s\n", task ? task->pid : 0, trans->fn); 3337 3338 /* trans->paths is rcu protected vs. freeing */ 3339 rcu_read_lock(); 3340 out->atomic++; 3341 3342 struct btree_path *paths = rcu_dereference(trans->paths); 3343 if (!paths) 3344 goto out; 3345 3346 unsigned long *paths_allocated = trans_paths_allocated(paths); 3347 3348 trans_for_each_path_idx_from(paths_allocated, *trans_paths_nr(paths), idx, 1) { 3349 struct btree_path *path = paths + idx; 3350 if (!path->nodes_locked) 3351 continue; 3352 3353 prt_printf(out, " path %u %c l=%u %s:", 3354 idx, 3355 path->cached ? 'c' : 'b', 3356 path->level, 3357 bch2_btree_id_str(path->btree_id)); 3358 bch2_bpos_to_text(out, path->pos); 3359 prt_newline(out); 3360 3361 for (l = 0; l < BTREE_MAX_DEPTH; l++) { 3362 if (btree_node_locked(path, l) && 3363 !IS_ERR_OR_NULL(b = (void *) READ_ONCE(path->l[l].b))) { 3364 prt_printf(out, " %c l=%u ", 3365 lock_types[btree_node_locked_type(path, l)], l); 3366 bch2_btree_bkey_cached_common_to_text(out, b); 3367 prt_newline(out); 3368 } 3369 } 3370 } 3371 3372 b = READ_ONCE(trans->locking); 3373 if (b) { 3374 prt_printf(out, " blocked for %lluus on\n", 3375 div_u64(local_clock() - trans->locking_wait.start_time, 1000)); 3376 prt_printf(out, " %c", lock_types[trans->locking_wait.lock_want]); 3377 bch2_btree_bkey_cached_common_to_text(out, b); 3378 prt_newline(out); 3379 } 3380 out: 3381 --out->atomic; 3382 rcu_read_unlock(); 3383 } 3384 3385 void bch2_fs_btree_iter_exit(struct bch_fs *c) 3386 { 3387 struct btree_transaction_stats *s; 3388 struct btree_trans *trans; 3389 int cpu; 3390 3391 if (c->btree_trans_bufs) 3392 for_each_possible_cpu(cpu) { 3393 struct btree_trans *trans = 3394 per_cpu_ptr(c->btree_trans_bufs, cpu)->trans; 3395 3396 if (trans) { 3397 seqmutex_lock(&c->btree_trans_lock); 3398 list_del(&trans->list); 3399 seqmutex_unlock(&c->btree_trans_lock); 3400 } 3401 kfree(trans); 3402 } 3403 free_percpu(c->btree_trans_bufs); 3404 3405 trans = list_first_entry_or_null(&c->btree_trans_list, struct btree_trans, list); 3406 if (trans) 3407 panic("%s leaked btree_trans\n", trans->fn); 3408 3409 for (s = c->btree_transaction_stats; 3410 s < c->btree_transaction_stats + ARRAY_SIZE(c->btree_transaction_stats); 3411 s++) { 3412 kfree(s->max_paths_text); 3413 bch2_time_stats_exit(&s->lock_hold_times); 3414 } 3415 3416 if (c->btree_trans_barrier_initialized) { 3417 synchronize_srcu_expedited(&c->btree_trans_barrier); 3418 cleanup_srcu_struct(&c->btree_trans_barrier); 3419 } 3420 mempool_exit(&c->btree_trans_mem_pool); 3421 mempool_exit(&c->btree_trans_pool); 3422 } 3423 3424 void bch2_fs_btree_iter_init_early(struct bch_fs *c) 3425 { 3426 struct btree_transaction_stats *s; 3427 3428 for (s = c->btree_transaction_stats; 3429 s < c->btree_transaction_stats + ARRAY_SIZE(c->btree_transaction_stats); 3430 s++) { 3431 bch2_time_stats_init(&s->duration); 3432 bch2_time_stats_init(&s->lock_hold_times); 3433 mutex_init(&s->lock); 3434 } 3435 3436 INIT_LIST_HEAD(&c->btree_trans_list); 3437 seqmutex_init(&c->btree_trans_lock); 3438 } 3439 3440 int bch2_fs_btree_iter_init(struct bch_fs *c) 3441 { 3442 int ret; 3443 3444 c->btree_trans_bufs = alloc_percpu(struct btree_trans_buf); 3445 if (!c->btree_trans_bufs) 3446 return -ENOMEM; 3447 3448 ret = mempool_init_kmalloc_pool(&c->btree_trans_pool, 1, 3449 sizeof(struct btree_trans)) ?: 3450 mempool_init_kmalloc_pool(&c->btree_trans_mem_pool, 1, 3451 BTREE_TRANS_MEM_MAX) ?: 3452 init_srcu_struct(&c->btree_trans_barrier); 3453 if (ret) 3454 return ret; 3455 3456 /* 3457 * static annotation (hackily done) for lock ordering of reclaim vs. 3458 * btree node locks: 3459 */ 3460 #ifdef CONFIG_LOCKDEP 3461 fs_reclaim_acquire(GFP_KERNEL); 3462 struct btree_trans *trans = bch2_trans_get(c); 3463 trans_set_locked(trans); 3464 bch2_trans_put(trans); 3465 fs_reclaim_release(GFP_KERNEL); 3466 #endif 3467 3468 c->btree_trans_barrier_initialized = true; 3469 return 0; 3470 3471 } 3472