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 struct btree *bch2_btree_iter_peek_node_and_restart(struct btree_iter *iter) 1904 { 1905 struct btree *b; 1906 1907 while (b = bch2_btree_iter_peek_node(iter), 1908 bch2_err_matches(PTR_ERR_OR_ZERO(b), BCH_ERR_transaction_restart)) 1909 bch2_trans_begin(iter->trans); 1910 1911 return b; 1912 } 1913 1914 struct btree *bch2_btree_iter_next_node(struct btree_iter *iter) 1915 { 1916 struct btree_trans *trans = iter->trans; 1917 struct btree *b = NULL; 1918 int ret; 1919 1920 EBUG_ON(trans->paths[iter->path].cached); 1921 bch2_trans_verify_not_in_restart(trans); 1922 bch2_btree_iter_verify(iter); 1923 1924 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags); 1925 if (ret) 1926 goto err; 1927 1928 1929 struct btree_path *path = btree_iter_path(trans, iter); 1930 1931 /* already at end? */ 1932 if (!btree_path_node(path, path->level)) 1933 return NULL; 1934 1935 /* got to end? */ 1936 if (!btree_path_node(path, path->level + 1)) { 1937 btree_path_set_level_up(trans, path); 1938 return NULL; 1939 } 1940 1941 if (!bch2_btree_node_relock(trans, path, path->level + 1)) { 1942 __bch2_btree_path_unlock(trans, path); 1943 path->l[path->level].b = ERR_PTR(-BCH_ERR_no_btree_node_relock); 1944 path->l[path->level + 1].b = ERR_PTR(-BCH_ERR_no_btree_node_relock); 1945 btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE); 1946 trace_and_count(trans->c, trans_restart_relock_next_node, trans, _THIS_IP_, path); 1947 ret = btree_trans_restart(trans, BCH_ERR_transaction_restart_relock); 1948 goto err; 1949 } 1950 1951 b = btree_path_node(path, path->level + 1); 1952 1953 if (bpos_eq(iter->pos, b->key.k.p)) { 1954 __btree_path_set_level_up(trans, path, path->level++); 1955 } else { 1956 if (btree_lock_want(path, path->level + 1) == BTREE_NODE_UNLOCKED) 1957 btree_node_unlock(trans, path, path->level + 1); 1958 1959 /* 1960 * Haven't gotten to the end of the parent node: go back down to 1961 * the next child node 1962 */ 1963 iter->path = bch2_btree_path_set_pos(trans, iter->path, 1964 bpos_successor(iter->pos), 1965 iter->flags & BTREE_ITER_intent, 1966 btree_iter_ip_allocated(iter)); 1967 1968 path = btree_iter_path(trans, iter); 1969 btree_path_set_level_down(trans, path, iter->min_depth); 1970 1971 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags); 1972 if (ret) 1973 goto err; 1974 1975 path = btree_iter_path(trans, iter); 1976 b = path->l[path->level].b; 1977 } 1978 1979 bkey_init(&iter->k); 1980 iter->k.p = iter->pos = b->key.k.p; 1981 1982 iter->path = bch2_btree_path_set_pos(trans, iter->path, b->key.k.p, 1983 iter->flags & BTREE_ITER_intent, 1984 btree_iter_ip_allocated(iter)); 1985 btree_path_set_should_be_locked(btree_iter_path(trans, iter)); 1986 EBUG_ON(btree_iter_path(trans, iter)->uptodate); 1987 out: 1988 bch2_btree_iter_verify_entry_exit(iter); 1989 bch2_btree_iter_verify(iter); 1990 1991 return b; 1992 err: 1993 b = ERR_PTR(ret); 1994 goto out; 1995 } 1996 1997 /* Iterate across keys (in leaf nodes only) */ 1998 1999 inline bool bch2_btree_iter_advance(struct btree_iter *iter) 2000 { 2001 struct bpos pos = iter->k.p; 2002 bool ret = !(iter->flags & BTREE_ITER_all_snapshots 2003 ? bpos_eq(pos, SPOS_MAX) 2004 : bkey_eq(pos, SPOS_MAX)); 2005 2006 if (ret && !(iter->flags & BTREE_ITER_is_extents)) 2007 pos = bkey_successor(iter, pos); 2008 bch2_btree_iter_set_pos(iter, pos); 2009 return ret; 2010 } 2011 2012 inline bool bch2_btree_iter_rewind(struct btree_iter *iter) 2013 { 2014 struct bpos pos = bkey_start_pos(&iter->k); 2015 bool ret = !(iter->flags & BTREE_ITER_all_snapshots 2016 ? bpos_eq(pos, POS_MIN) 2017 : bkey_eq(pos, POS_MIN)); 2018 2019 if (ret && !(iter->flags & BTREE_ITER_is_extents)) 2020 pos = bkey_predecessor(iter, pos); 2021 bch2_btree_iter_set_pos(iter, pos); 2022 return ret; 2023 } 2024 2025 static noinline 2026 void bch2_btree_trans_peek_prev_updates(struct btree_trans *trans, struct btree_iter *iter, 2027 struct bkey_s_c *k) 2028 { 2029 struct bpos end = path_l(btree_iter_path(trans, iter))->b->data->min_key; 2030 2031 trans_for_each_update(trans, i) 2032 if (!i->key_cache_already_flushed && 2033 i->btree_id == iter->btree_id && 2034 bpos_le(i->k->k.p, iter->pos) && 2035 bpos_ge(i->k->k.p, k->k ? k->k->p : end)) { 2036 iter->k = i->k->k; 2037 *k = bkey_i_to_s_c(i->k); 2038 } 2039 } 2040 2041 static noinline 2042 void bch2_btree_trans_peek_updates(struct btree_trans *trans, struct btree_iter *iter, 2043 struct bkey_s_c *k) 2044 { 2045 struct btree_path *path = btree_iter_path(trans, iter); 2046 struct bpos end = path_l(path)->b->key.k.p; 2047 2048 trans_for_each_update(trans, i) 2049 if (!i->key_cache_already_flushed && 2050 i->btree_id == iter->btree_id && 2051 bpos_ge(i->k->k.p, path->pos) && 2052 bpos_le(i->k->k.p, k->k ? k->k->p : end)) { 2053 iter->k = i->k->k; 2054 *k = bkey_i_to_s_c(i->k); 2055 } 2056 } 2057 2058 static noinline 2059 void bch2_btree_trans_peek_slot_updates(struct btree_trans *trans, struct btree_iter *iter, 2060 struct bkey_s_c *k) 2061 { 2062 trans_for_each_update(trans, i) 2063 if (!i->key_cache_already_flushed && 2064 i->btree_id == iter->btree_id && 2065 bpos_eq(i->k->k.p, iter->pos)) { 2066 iter->k = i->k->k; 2067 *k = bkey_i_to_s_c(i->k); 2068 } 2069 } 2070 2071 static struct bkey_i *bch2_btree_journal_peek(struct btree_trans *trans, 2072 struct btree_iter *iter, 2073 struct bpos end_pos) 2074 { 2075 struct btree_path *path = btree_iter_path(trans, iter); 2076 2077 return bch2_journal_keys_peek_upto(trans->c, iter->btree_id, 2078 path->level, 2079 path->pos, 2080 end_pos, 2081 &iter->journal_idx); 2082 } 2083 2084 static noinline 2085 struct bkey_s_c btree_trans_peek_slot_journal(struct btree_trans *trans, 2086 struct btree_iter *iter) 2087 { 2088 struct btree_path *path = btree_iter_path(trans, iter); 2089 struct bkey_i *k = bch2_btree_journal_peek(trans, iter, path->pos); 2090 2091 if (k) { 2092 iter->k = k->k; 2093 return bkey_i_to_s_c(k); 2094 } else { 2095 return bkey_s_c_null; 2096 } 2097 } 2098 2099 static noinline 2100 struct bkey_s_c btree_trans_peek_journal(struct btree_trans *trans, 2101 struct btree_iter *iter, 2102 struct bkey_s_c k) 2103 { 2104 struct btree_path *path = btree_iter_path(trans, iter); 2105 struct bkey_i *next_journal = 2106 bch2_btree_journal_peek(trans, iter, 2107 k.k ? k.k->p : path_l(path)->b->key.k.p); 2108 2109 if (next_journal) { 2110 iter->k = next_journal->k; 2111 k = bkey_i_to_s_c(next_journal); 2112 } 2113 2114 return k; 2115 } 2116 2117 /* 2118 * Checks btree key cache for key at iter->pos and returns it if present, or 2119 * bkey_s_c_null: 2120 */ 2121 static noinline 2122 struct bkey_s_c btree_trans_peek_key_cache(struct btree_iter *iter, struct bpos pos) 2123 { 2124 struct btree_trans *trans = iter->trans; 2125 struct bch_fs *c = trans->c; 2126 struct bkey u; 2127 struct bkey_s_c k; 2128 int ret; 2129 2130 bch2_trans_verify_not_in_restart(trans); 2131 bch2_trans_verify_not_unlocked(trans); 2132 2133 if ((iter->flags & BTREE_ITER_key_cache_fill) && 2134 bpos_eq(iter->pos, pos)) 2135 return bkey_s_c_null; 2136 2137 if (!bch2_btree_key_cache_find(c, iter->btree_id, pos)) 2138 return bkey_s_c_null; 2139 2140 if (!iter->key_cache_path) 2141 iter->key_cache_path = bch2_path_get(trans, iter->btree_id, pos, 2142 iter->flags & BTREE_ITER_intent, 0, 2143 iter->flags|BTREE_ITER_cached| 2144 BTREE_ITER_cached_nofill, 2145 _THIS_IP_); 2146 2147 iter->key_cache_path = bch2_btree_path_set_pos(trans, iter->key_cache_path, pos, 2148 iter->flags & BTREE_ITER_intent, 2149 btree_iter_ip_allocated(iter)); 2150 2151 ret = bch2_btree_path_traverse(trans, iter->key_cache_path, 2152 iter->flags|BTREE_ITER_cached) ?: 2153 bch2_btree_path_relock(trans, btree_iter_path(trans, iter), _THIS_IP_); 2154 if (unlikely(ret)) 2155 return bkey_s_c_err(ret); 2156 2157 btree_path_set_should_be_locked(trans->paths + iter->key_cache_path); 2158 2159 k = bch2_btree_path_peek_slot(trans->paths + iter->key_cache_path, &u); 2160 if (k.k && !bkey_err(k)) { 2161 iter->k = u; 2162 k.k = &iter->k; 2163 } 2164 return k; 2165 } 2166 2167 static struct bkey_s_c __bch2_btree_iter_peek(struct btree_iter *iter, struct bpos search_key) 2168 { 2169 struct btree_trans *trans = iter->trans; 2170 struct bkey_s_c k, k2; 2171 int ret; 2172 2173 EBUG_ON(btree_iter_path(trans, iter)->cached); 2174 bch2_btree_iter_verify(iter); 2175 2176 while (1) { 2177 struct btree_path_level *l; 2178 2179 iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key, 2180 iter->flags & BTREE_ITER_intent, 2181 btree_iter_ip_allocated(iter)); 2182 2183 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags); 2184 if (unlikely(ret)) { 2185 /* ensure that iter->k is consistent with iter->pos: */ 2186 bch2_btree_iter_set_pos(iter, iter->pos); 2187 k = bkey_s_c_err(ret); 2188 goto out; 2189 } 2190 2191 struct btree_path *path = btree_iter_path(trans, iter); 2192 l = path_l(path); 2193 2194 if (unlikely(!l->b)) { 2195 /* No btree nodes at requested level: */ 2196 bch2_btree_iter_set_pos(iter, SPOS_MAX); 2197 k = bkey_s_c_null; 2198 goto out; 2199 } 2200 2201 btree_path_set_should_be_locked(path); 2202 2203 k = btree_path_level_peek_all(trans->c, l, &iter->k); 2204 2205 if (unlikely(iter->flags & BTREE_ITER_with_key_cache) && 2206 k.k && 2207 (k2 = btree_trans_peek_key_cache(iter, k.k->p)).k) { 2208 k = k2; 2209 ret = bkey_err(k); 2210 if (ret) { 2211 bch2_btree_iter_set_pos(iter, iter->pos); 2212 goto out; 2213 } 2214 } 2215 2216 if (unlikely(iter->flags & BTREE_ITER_with_journal)) 2217 k = btree_trans_peek_journal(trans, iter, k); 2218 2219 if (unlikely((iter->flags & BTREE_ITER_with_updates) && 2220 trans->nr_updates)) 2221 bch2_btree_trans_peek_updates(trans, iter, &k); 2222 2223 if (k.k && bkey_deleted(k.k)) { 2224 /* 2225 * If we've got a whiteout, and it's after the search 2226 * key, advance the search key to the whiteout instead 2227 * of just after the whiteout - it might be a btree 2228 * whiteout, with a real key at the same position, since 2229 * in the btree deleted keys sort before non deleted. 2230 */ 2231 search_key = !bpos_eq(search_key, k.k->p) 2232 ? k.k->p 2233 : bpos_successor(k.k->p); 2234 continue; 2235 } 2236 2237 if (likely(k.k)) { 2238 break; 2239 } else if (likely(!bpos_eq(l->b->key.k.p, SPOS_MAX))) { 2240 /* Advance to next leaf node: */ 2241 search_key = bpos_successor(l->b->key.k.p); 2242 } else { 2243 /* End of btree: */ 2244 bch2_btree_iter_set_pos(iter, SPOS_MAX); 2245 k = bkey_s_c_null; 2246 goto out; 2247 } 2248 } 2249 out: 2250 bch2_btree_iter_verify(iter); 2251 2252 return k; 2253 } 2254 2255 /** 2256 * bch2_btree_iter_peek_upto() - returns first key greater than or equal to 2257 * iterator's current position 2258 * @iter: iterator to peek from 2259 * @end: search limit: returns keys less than or equal to @end 2260 * 2261 * Returns: key if found, or an error extractable with bkey_err(). 2262 */ 2263 struct bkey_s_c bch2_btree_iter_peek_upto(struct btree_iter *iter, struct bpos end) 2264 { 2265 struct btree_trans *trans = iter->trans; 2266 struct bpos search_key = btree_iter_search_key(iter); 2267 struct bkey_s_c k; 2268 struct bpos iter_pos; 2269 int ret; 2270 2271 bch2_trans_verify_not_unlocked(trans); 2272 EBUG_ON((iter->flags & BTREE_ITER_filter_snapshots) && bkey_eq(end, POS_MAX)); 2273 2274 if (iter->update_path) { 2275 bch2_path_put_nokeep(trans, iter->update_path, 2276 iter->flags & BTREE_ITER_intent); 2277 iter->update_path = 0; 2278 } 2279 2280 bch2_btree_iter_verify_entry_exit(iter); 2281 2282 while (1) { 2283 k = __bch2_btree_iter_peek(iter, search_key); 2284 if (unlikely(!k.k)) 2285 goto end; 2286 if (unlikely(bkey_err(k))) 2287 goto out_no_locked; 2288 2289 /* 2290 * We need to check against @end before FILTER_SNAPSHOTS because 2291 * if we get to a different inode that requested we might be 2292 * seeing keys for a different snapshot tree that will all be 2293 * filtered out. 2294 * 2295 * But we can't do the full check here, because bkey_start_pos() 2296 * isn't monotonically increasing before FILTER_SNAPSHOTS, and 2297 * that's what we check against in extents mode: 2298 */ 2299 if (unlikely(!(iter->flags & BTREE_ITER_is_extents) 2300 ? bkey_gt(k.k->p, end) 2301 : k.k->p.inode > end.inode)) 2302 goto end; 2303 2304 if (iter->update_path && 2305 !bkey_eq(trans->paths[iter->update_path].pos, k.k->p)) { 2306 bch2_path_put_nokeep(trans, iter->update_path, 2307 iter->flags & BTREE_ITER_intent); 2308 iter->update_path = 0; 2309 } 2310 2311 if ((iter->flags & BTREE_ITER_filter_snapshots) && 2312 (iter->flags & BTREE_ITER_intent) && 2313 !(iter->flags & BTREE_ITER_is_extents) && 2314 !iter->update_path) { 2315 struct bpos pos = k.k->p; 2316 2317 if (pos.snapshot < iter->snapshot) { 2318 search_key = bpos_successor(k.k->p); 2319 continue; 2320 } 2321 2322 pos.snapshot = iter->snapshot; 2323 2324 /* 2325 * advance, same as on exit for iter->path, but only up 2326 * to snapshot 2327 */ 2328 __btree_path_get(trans->paths + iter->path, iter->flags & BTREE_ITER_intent); 2329 iter->update_path = iter->path; 2330 2331 iter->update_path = bch2_btree_path_set_pos(trans, 2332 iter->update_path, pos, 2333 iter->flags & BTREE_ITER_intent, 2334 _THIS_IP_); 2335 ret = bch2_btree_path_traverse(trans, iter->update_path, iter->flags); 2336 if (unlikely(ret)) { 2337 k = bkey_s_c_err(ret); 2338 goto out_no_locked; 2339 } 2340 } 2341 2342 /* 2343 * We can never have a key in a leaf node at POS_MAX, so 2344 * we don't have to check these successor() calls: 2345 */ 2346 if ((iter->flags & BTREE_ITER_filter_snapshots) && 2347 !bch2_snapshot_is_ancestor(trans->c, 2348 iter->snapshot, 2349 k.k->p.snapshot)) { 2350 search_key = bpos_successor(k.k->p); 2351 continue; 2352 } 2353 2354 if (bkey_whiteout(k.k) && 2355 !(iter->flags & BTREE_ITER_all_snapshots)) { 2356 search_key = bkey_successor(iter, k.k->p); 2357 continue; 2358 } 2359 2360 /* 2361 * iter->pos should be mononotically increasing, and always be 2362 * equal to the key we just returned - except extents can 2363 * straddle iter->pos: 2364 */ 2365 if (!(iter->flags & BTREE_ITER_is_extents)) 2366 iter_pos = k.k->p; 2367 else 2368 iter_pos = bkey_max(iter->pos, bkey_start_pos(k.k)); 2369 2370 if (unlikely(!(iter->flags & BTREE_ITER_is_extents) 2371 ? bkey_gt(iter_pos, end) 2372 : bkey_ge(iter_pos, end))) 2373 goto end; 2374 2375 break; 2376 } 2377 2378 iter->pos = iter_pos; 2379 2380 iter->path = bch2_btree_path_set_pos(trans, iter->path, k.k->p, 2381 iter->flags & BTREE_ITER_intent, 2382 btree_iter_ip_allocated(iter)); 2383 2384 btree_path_set_should_be_locked(btree_iter_path(trans, iter)); 2385 out_no_locked: 2386 if (iter->update_path) { 2387 ret = bch2_btree_path_relock(trans, trans->paths + iter->update_path, _THIS_IP_); 2388 if (unlikely(ret)) 2389 k = bkey_s_c_err(ret); 2390 else 2391 btree_path_set_should_be_locked(trans->paths + iter->update_path); 2392 } 2393 2394 if (!(iter->flags & BTREE_ITER_all_snapshots)) 2395 iter->pos.snapshot = iter->snapshot; 2396 2397 ret = bch2_btree_iter_verify_ret(iter, k); 2398 if (unlikely(ret)) { 2399 bch2_btree_iter_set_pos(iter, iter->pos); 2400 k = bkey_s_c_err(ret); 2401 } 2402 2403 bch2_btree_iter_verify_entry_exit(iter); 2404 2405 return k; 2406 end: 2407 bch2_btree_iter_set_pos(iter, end); 2408 k = bkey_s_c_null; 2409 goto out_no_locked; 2410 } 2411 2412 /** 2413 * bch2_btree_iter_next() - returns first key greater than iterator's current 2414 * position 2415 * @iter: iterator to peek from 2416 * 2417 * Returns: key if found, or an error extractable with bkey_err(). 2418 */ 2419 struct bkey_s_c bch2_btree_iter_next(struct btree_iter *iter) 2420 { 2421 if (!bch2_btree_iter_advance(iter)) 2422 return bkey_s_c_null; 2423 2424 return bch2_btree_iter_peek(iter); 2425 } 2426 2427 /** 2428 * bch2_btree_iter_peek_prev() - returns first key less than or equal to 2429 * iterator's current position 2430 * @iter: iterator to peek from 2431 * 2432 * Returns: key if found, or an error extractable with bkey_err(). 2433 */ 2434 struct bkey_s_c bch2_btree_iter_peek_prev(struct btree_iter *iter) 2435 { 2436 struct btree_trans *trans = iter->trans; 2437 struct bpos search_key = iter->pos; 2438 struct bkey_s_c k; 2439 struct bkey saved_k; 2440 const struct bch_val *saved_v; 2441 btree_path_idx_t saved_path = 0; 2442 int ret; 2443 2444 bch2_trans_verify_not_unlocked(trans); 2445 EBUG_ON(btree_iter_path(trans, iter)->cached || 2446 btree_iter_path(trans, iter)->level); 2447 2448 if (iter->flags & BTREE_ITER_with_journal) 2449 return bkey_s_c_err(-BCH_ERR_btree_iter_with_journal_not_supported); 2450 2451 bch2_btree_iter_verify(iter); 2452 bch2_btree_iter_verify_entry_exit(iter); 2453 2454 if (iter->flags & BTREE_ITER_filter_snapshots) 2455 search_key.snapshot = U32_MAX; 2456 2457 while (1) { 2458 iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key, 2459 iter->flags & BTREE_ITER_intent, 2460 btree_iter_ip_allocated(iter)); 2461 2462 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags); 2463 if (unlikely(ret)) { 2464 /* ensure that iter->k is consistent with iter->pos: */ 2465 bch2_btree_iter_set_pos(iter, iter->pos); 2466 k = bkey_s_c_err(ret); 2467 goto out_no_locked; 2468 } 2469 2470 struct btree_path *path = btree_iter_path(trans, iter); 2471 2472 k = btree_path_level_peek(trans, path, &path->l[0], &iter->k); 2473 if (!k.k || 2474 ((iter->flags & BTREE_ITER_is_extents) 2475 ? bpos_ge(bkey_start_pos(k.k), search_key) 2476 : bpos_gt(k.k->p, search_key))) 2477 k = btree_path_level_prev(trans, path, &path->l[0], &iter->k); 2478 2479 if (unlikely((iter->flags & BTREE_ITER_with_updates) && 2480 trans->nr_updates)) 2481 bch2_btree_trans_peek_prev_updates(trans, iter, &k); 2482 2483 if (likely(k.k)) { 2484 if (iter->flags & BTREE_ITER_filter_snapshots) { 2485 if (k.k->p.snapshot == iter->snapshot) 2486 goto got_key; 2487 2488 /* 2489 * If we have a saved candidate, and we're no 2490 * longer at the same _key_ (not pos), return 2491 * that candidate 2492 */ 2493 if (saved_path && !bkey_eq(k.k->p, saved_k.p)) { 2494 bch2_path_put_nokeep(trans, iter->path, 2495 iter->flags & BTREE_ITER_intent); 2496 iter->path = saved_path; 2497 saved_path = 0; 2498 iter->k = saved_k; 2499 k.v = saved_v; 2500 goto got_key; 2501 } 2502 2503 if (bch2_snapshot_is_ancestor(trans->c, 2504 iter->snapshot, 2505 k.k->p.snapshot)) { 2506 if (saved_path) 2507 bch2_path_put_nokeep(trans, saved_path, 2508 iter->flags & BTREE_ITER_intent); 2509 saved_path = btree_path_clone(trans, iter->path, 2510 iter->flags & BTREE_ITER_intent, 2511 _THIS_IP_); 2512 path = btree_iter_path(trans, iter); 2513 saved_k = *k.k; 2514 saved_v = k.v; 2515 } 2516 2517 search_key = bpos_predecessor(k.k->p); 2518 continue; 2519 } 2520 got_key: 2521 if (bkey_whiteout(k.k) && 2522 !(iter->flags & BTREE_ITER_all_snapshots)) { 2523 search_key = bkey_predecessor(iter, k.k->p); 2524 if (iter->flags & BTREE_ITER_filter_snapshots) 2525 search_key.snapshot = U32_MAX; 2526 continue; 2527 } 2528 2529 btree_path_set_should_be_locked(path); 2530 break; 2531 } else if (likely(!bpos_eq(path->l[0].b->data->min_key, POS_MIN))) { 2532 /* Advance to previous leaf node: */ 2533 search_key = bpos_predecessor(path->l[0].b->data->min_key); 2534 } else { 2535 /* Start of btree: */ 2536 bch2_btree_iter_set_pos(iter, POS_MIN); 2537 k = bkey_s_c_null; 2538 goto out_no_locked; 2539 } 2540 } 2541 2542 EBUG_ON(bkey_gt(bkey_start_pos(k.k), iter->pos)); 2543 2544 /* Extents can straddle iter->pos: */ 2545 if (bkey_lt(k.k->p, iter->pos)) 2546 iter->pos = k.k->p; 2547 2548 if (iter->flags & BTREE_ITER_filter_snapshots) 2549 iter->pos.snapshot = iter->snapshot; 2550 out_no_locked: 2551 if (saved_path) 2552 bch2_path_put_nokeep(trans, saved_path, iter->flags & BTREE_ITER_intent); 2553 2554 bch2_btree_iter_verify_entry_exit(iter); 2555 bch2_btree_iter_verify(iter); 2556 2557 return k; 2558 } 2559 2560 /** 2561 * bch2_btree_iter_prev() - returns first key less than iterator's current 2562 * position 2563 * @iter: iterator to peek from 2564 * 2565 * Returns: key if found, or an error extractable with bkey_err(). 2566 */ 2567 struct bkey_s_c bch2_btree_iter_prev(struct btree_iter *iter) 2568 { 2569 if (!bch2_btree_iter_rewind(iter)) 2570 return bkey_s_c_null; 2571 2572 return bch2_btree_iter_peek_prev(iter); 2573 } 2574 2575 struct bkey_s_c bch2_btree_iter_peek_slot(struct btree_iter *iter) 2576 { 2577 struct btree_trans *trans = iter->trans; 2578 struct bpos search_key; 2579 struct bkey_s_c k; 2580 int ret; 2581 2582 bch2_trans_verify_not_unlocked(trans); 2583 bch2_btree_iter_verify(iter); 2584 bch2_btree_iter_verify_entry_exit(iter); 2585 EBUG_ON(btree_iter_path(trans, iter)->level && (iter->flags & BTREE_ITER_with_key_cache)); 2586 2587 /* extents can't span inode numbers: */ 2588 if ((iter->flags & BTREE_ITER_is_extents) && 2589 unlikely(iter->pos.offset == KEY_OFFSET_MAX)) { 2590 if (iter->pos.inode == KEY_INODE_MAX) 2591 return bkey_s_c_null; 2592 2593 bch2_btree_iter_set_pos(iter, bpos_nosnap_successor(iter->pos)); 2594 } 2595 2596 search_key = btree_iter_search_key(iter); 2597 iter->path = bch2_btree_path_set_pos(trans, iter->path, search_key, 2598 iter->flags & BTREE_ITER_intent, 2599 btree_iter_ip_allocated(iter)); 2600 2601 ret = bch2_btree_path_traverse(trans, iter->path, iter->flags); 2602 if (unlikely(ret)) { 2603 k = bkey_s_c_err(ret); 2604 goto out_no_locked; 2605 } 2606 2607 if ((iter->flags & BTREE_ITER_cached) || 2608 !(iter->flags & (BTREE_ITER_is_extents|BTREE_ITER_filter_snapshots))) { 2609 k = bkey_s_c_null; 2610 2611 if (unlikely((iter->flags & BTREE_ITER_with_updates) && 2612 trans->nr_updates)) { 2613 bch2_btree_trans_peek_slot_updates(trans, iter, &k); 2614 if (k.k) 2615 goto out; 2616 } 2617 2618 if (unlikely(iter->flags & BTREE_ITER_with_journal) && 2619 (k = btree_trans_peek_slot_journal(trans, iter)).k) 2620 goto out; 2621 2622 if (unlikely(iter->flags & BTREE_ITER_with_key_cache) && 2623 (k = btree_trans_peek_key_cache(iter, iter->pos)).k) { 2624 if (!bkey_err(k)) 2625 iter->k = *k.k; 2626 /* We're not returning a key from iter->path: */ 2627 goto out_no_locked; 2628 } 2629 2630 k = bch2_btree_path_peek_slot(trans->paths + iter->path, &iter->k); 2631 if (unlikely(!k.k)) 2632 goto out_no_locked; 2633 } else { 2634 struct bpos next; 2635 struct bpos end = iter->pos; 2636 2637 if (iter->flags & BTREE_ITER_is_extents) 2638 end.offset = U64_MAX; 2639 2640 EBUG_ON(btree_iter_path(trans, iter)->level); 2641 2642 if (iter->flags & BTREE_ITER_intent) { 2643 struct btree_iter iter2; 2644 2645 bch2_trans_copy_iter(&iter2, iter); 2646 k = bch2_btree_iter_peek_upto(&iter2, end); 2647 2648 if (k.k && !bkey_err(k)) { 2649 swap(iter->key_cache_path, iter2.key_cache_path); 2650 iter->k = iter2.k; 2651 k.k = &iter->k; 2652 } 2653 bch2_trans_iter_exit(trans, &iter2); 2654 } else { 2655 struct bpos pos = iter->pos; 2656 2657 k = bch2_btree_iter_peek_upto(iter, end); 2658 if (unlikely(bkey_err(k))) 2659 bch2_btree_iter_set_pos(iter, pos); 2660 else 2661 iter->pos = pos; 2662 } 2663 2664 if (unlikely(bkey_err(k))) 2665 goto out_no_locked; 2666 2667 next = k.k ? bkey_start_pos(k.k) : POS_MAX; 2668 2669 if (bkey_lt(iter->pos, next)) { 2670 bkey_init(&iter->k); 2671 iter->k.p = iter->pos; 2672 2673 if (iter->flags & BTREE_ITER_is_extents) { 2674 bch2_key_resize(&iter->k, 2675 min_t(u64, KEY_SIZE_MAX, 2676 (next.inode == iter->pos.inode 2677 ? next.offset 2678 : KEY_OFFSET_MAX) - 2679 iter->pos.offset)); 2680 EBUG_ON(!iter->k.size); 2681 } 2682 2683 k = (struct bkey_s_c) { &iter->k, NULL }; 2684 } 2685 } 2686 out: 2687 btree_path_set_should_be_locked(btree_iter_path(trans, iter)); 2688 out_no_locked: 2689 bch2_btree_iter_verify_entry_exit(iter); 2690 bch2_btree_iter_verify(iter); 2691 ret = bch2_btree_iter_verify_ret(iter, k); 2692 if (unlikely(ret)) 2693 return bkey_s_c_err(ret); 2694 2695 return k; 2696 } 2697 2698 struct bkey_s_c bch2_btree_iter_next_slot(struct btree_iter *iter) 2699 { 2700 if (!bch2_btree_iter_advance(iter)) 2701 return bkey_s_c_null; 2702 2703 return bch2_btree_iter_peek_slot(iter); 2704 } 2705 2706 struct bkey_s_c bch2_btree_iter_prev_slot(struct btree_iter *iter) 2707 { 2708 if (!bch2_btree_iter_rewind(iter)) 2709 return bkey_s_c_null; 2710 2711 return bch2_btree_iter_peek_slot(iter); 2712 } 2713 2714 struct bkey_s_c bch2_btree_iter_peek_and_restart_outlined(struct btree_iter *iter) 2715 { 2716 struct bkey_s_c k; 2717 2718 while (btree_trans_too_many_iters(iter->trans) || 2719 (k = bch2_btree_iter_peek_type(iter, iter->flags), 2720 bch2_err_matches(bkey_err(k), BCH_ERR_transaction_restart))) 2721 bch2_trans_begin(iter->trans); 2722 2723 return k; 2724 } 2725 2726 /* new transactional stuff: */ 2727 2728 #ifdef CONFIG_BCACHEFS_DEBUG 2729 static void btree_trans_verify_sorted_refs(struct btree_trans *trans) 2730 { 2731 struct btree_path *path; 2732 unsigned i; 2733 2734 BUG_ON(trans->nr_sorted != bitmap_weight(trans->paths_allocated, trans->nr_paths) - 1); 2735 2736 trans_for_each_path(trans, path, i) { 2737 BUG_ON(path->sorted_idx >= trans->nr_sorted); 2738 BUG_ON(trans->sorted[path->sorted_idx] != i); 2739 } 2740 2741 for (i = 0; i < trans->nr_sorted; i++) { 2742 unsigned idx = trans->sorted[i]; 2743 2744 BUG_ON(!test_bit(idx, trans->paths_allocated)); 2745 BUG_ON(trans->paths[idx].sorted_idx != i); 2746 } 2747 } 2748 2749 static void btree_trans_verify_sorted(struct btree_trans *trans) 2750 { 2751 struct btree_path *path, *prev = NULL; 2752 struct trans_for_each_path_inorder_iter iter; 2753 2754 if (!bch2_debug_check_iterators) 2755 return; 2756 2757 trans_for_each_path_inorder(trans, path, iter) { 2758 if (prev && btree_path_cmp(prev, path) > 0) { 2759 __bch2_dump_trans_paths_updates(trans, true); 2760 panic("trans paths out of order!\n"); 2761 } 2762 prev = path; 2763 } 2764 } 2765 #else 2766 static inline void btree_trans_verify_sorted_refs(struct btree_trans *trans) {} 2767 static inline void btree_trans_verify_sorted(struct btree_trans *trans) {} 2768 #endif 2769 2770 void __bch2_btree_trans_sort_paths(struct btree_trans *trans) 2771 { 2772 int i, l = 0, r = trans->nr_sorted, inc = 1; 2773 bool swapped; 2774 2775 btree_trans_verify_sorted_refs(trans); 2776 2777 if (trans->paths_sorted) 2778 goto out; 2779 2780 /* 2781 * Cocktail shaker sort: this is efficient because iterators will be 2782 * mostly sorted. 2783 */ 2784 do { 2785 swapped = false; 2786 2787 for (i = inc > 0 ? l : r - 2; 2788 i + 1 < r && i >= l; 2789 i += inc) { 2790 if (btree_path_cmp(trans->paths + trans->sorted[i], 2791 trans->paths + trans->sorted[i + 1]) > 0) { 2792 swap(trans->sorted[i], trans->sorted[i + 1]); 2793 trans->paths[trans->sorted[i]].sorted_idx = i; 2794 trans->paths[trans->sorted[i + 1]].sorted_idx = i + 1; 2795 swapped = true; 2796 } 2797 } 2798 2799 if (inc > 0) 2800 --r; 2801 else 2802 l++; 2803 inc = -inc; 2804 } while (swapped); 2805 2806 trans->paths_sorted = true; 2807 out: 2808 btree_trans_verify_sorted(trans); 2809 } 2810 2811 static inline void btree_path_list_remove(struct btree_trans *trans, 2812 struct btree_path *path) 2813 { 2814 EBUG_ON(path->sorted_idx >= trans->nr_sorted); 2815 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 2816 trans->nr_sorted--; 2817 memmove_u64s_down_small(trans->sorted + path->sorted_idx, 2818 trans->sorted + path->sorted_idx + 1, 2819 DIV_ROUND_UP(trans->nr_sorted - path->sorted_idx, 2820 sizeof(u64) / sizeof(btree_path_idx_t))); 2821 #else 2822 array_remove_item(trans->sorted, trans->nr_sorted, path->sorted_idx); 2823 #endif 2824 for (unsigned i = path->sorted_idx; i < trans->nr_sorted; i++) 2825 trans->paths[trans->sorted[i]].sorted_idx = i; 2826 } 2827 2828 static inline void btree_path_list_add(struct btree_trans *trans, 2829 btree_path_idx_t pos, 2830 btree_path_idx_t path_idx) 2831 { 2832 struct btree_path *path = trans->paths + path_idx; 2833 2834 path->sorted_idx = pos ? trans->paths[pos].sorted_idx + 1 : trans->nr_sorted; 2835 2836 #ifdef CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS 2837 memmove_u64s_up_small(trans->sorted + path->sorted_idx + 1, 2838 trans->sorted + path->sorted_idx, 2839 DIV_ROUND_UP(trans->nr_sorted - path->sorted_idx, 2840 sizeof(u64) / sizeof(btree_path_idx_t))); 2841 trans->nr_sorted++; 2842 trans->sorted[path->sorted_idx] = path_idx; 2843 #else 2844 array_insert_item(trans->sorted, trans->nr_sorted, path->sorted_idx, path_idx); 2845 #endif 2846 2847 for (unsigned i = path->sorted_idx; i < trans->nr_sorted; i++) 2848 trans->paths[trans->sorted[i]].sorted_idx = i; 2849 2850 btree_trans_verify_sorted_refs(trans); 2851 } 2852 2853 void bch2_trans_iter_exit(struct btree_trans *trans, struct btree_iter *iter) 2854 { 2855 if (iter->update_path) 2856 bch2_path_put_nokeep(trans, iter->update_path, 2857 iter->flags & BTREE_ITER_intent); 2858 if (iter->path) 2859 bch2_path_put(trans, iter->path, 2860 iter->flags & BTREE_ITER_intent); 2861 if (iter->key_cache_path) 2862 bch2_path_put(trans, iter->key_cache_path, 2863 iter->flags & BTREE_ITER_intent); 2864 iter->path = 0; 2865 iter->update_path = 0; 2866 iter->key_cache_path = 0; 2867 iter->trans = NULL; 2868 } 2869 2870 void bch2_trans_iter_init_outlined(struct btree_trans *trans, 2871 struct btree_iter *iter, 2872 enum btree_id btree_id, struct bpos pos, 2873 unsigned flags) 2874 { 2875 bch2_trans_iter_init_common(trans, iter, btree_id, pos, 0, 0, 2876 bch2_btree_iter_flags(trans, btree_id, flags), 2877 _RET_IP_); 2878 } 2879 2880 void bch2_trans_node_iter_init(struct btree_trans *trans, 2881 struct btree_iter *iter, 2882 enum btree_id btree_id, 2883 struct bpos pos, 2884 unsigned locks_want, 2885 unsigned depth, 2886 unsigned flags) 2887 { 2888 flags |= BTREE_ITER_not_extents; 2889 flags |= BTREE_ITER_snapshot_field; 2890 flags |= BTREE_ITER_all_snapshots; 2891 2892 bch2_trans_iter_init_common(trans, iter, btree_id, pos, locks_want, depth, 2893 __bch2_btree_iter_flags(trans, btree_id, flags), 2894 _RET_IP_); 2895 2896 iter->min_depth = depth; 2897 2898 struct btree_path *path = btree_iter_path(trans, iter); 2899 BUG_ON(path->locks_want < min(locks_want, BTREE_MAX_DEPTH)); 2900 BUG_ON(path->level != depth); 2901 BUG_ON(iter->min_depth != depth); 2902 } 2903 2904 void bch2_trans_copy_iter(struct btree_iter *dst, struct btree_iter *src) 2905 { 2906 struct btree_trans *trans = src->trans; 2907 2908 *dst = *src; 2909 #ifdef TRACK_PATH_ALLOCATED 2910 dst->ip_allocated = _RET_IP_; 2911 #endif 2912 if (src->path) 2913 __btree_path_get(trans->paths + src->path, src->flags & BTREE_ITER_intent); 2914 if (src->update_path) 2915 __btree_path_get(trans->paths + src->update_path, src->flags & BTREE_ITER_intent); 2916 dst->key_cache_path = 0; 2917 } 2918 2919 void *__bch2_trans_kmalloc(struct btree_trans *trans, size_t size) 2920 { 2921 struct bch_fs *c = trans->c; 2922 unsigned new_top = trans->mem_top + size; 2923 unsigned old_bytes = trans->mem_bytes; 2924 unsigned new_bytes = roundup_pow_of_two(new_top); 2925 int ret; 2926 void *new_mem; 2927 void *p; 2928 2929 WARN_ON_ONCE(new_bytes > BTREE_TRANS_MEM_MAX); 2930 2931 struct btree_transaction_stats *s = btree_trans_stats(trans); 2932 s->max_mem = max(s->max_mem, new_bytes); 2933 2934 if (trans->used_mempool) { 2935 if (trans->mem_bytes >= new_bytes) 2936 goto out_change_top; 2937 2938 /* No more space from mempool item, need malloc new one */ 2939 new_mem = kmalloc(new_bytes, GFP_NOWAIT|__GFP_NOWARN); 2940 if (unlikely(!new_mem)) { 2941 bch2_trans_unlock(trans); 2942 2943 new_mem = kmalloc(new_bytes, GFP_KERNEL); 2944 if (!new_mem) 2945 return ERR_PTR(-BCH_ERR_ENOMEM_trans_kmalloc); 2946 2947 ret = bch2_trans_relock(trans); 2948 if (ret) { 2949 kfree(new_mem); 2950 return ERR_PTR(ret); 2951 } 2952 } 2953 memcpy(new_mem, trans->mem, trans->mem_top); 2954 trans->used_mempool = false; 2955 mempool_free(trans->mem, &c->btree_trans_mem_pool); 2956 goto out_new_mem; 2957 } 2958 2959 new_mem = krealloc(trans->mem, new_bytes, GFP_NOWAIT|__GFP_NOWARN); 2960 if (unlikely(!new_mem)) { 2961 bch2_trans_unlock(trans); 2962 2963 new_mem = krealloc(trans->mem, new_bytes, GFP_KERNEL); 2964 if (!new_mem && new_bytes <= BTREE_TRANS_MEM_MAX) { 2965 new_mem = mempool_alloc(&c->btree_trans_mem_pool, GFP_KERNEL); 2966 new_bytes = BTREE_TRANS_MEM_MAX; 2967 memcpy(new_mem, trans->mem, trans->mem_top); 2968 trans->used_mempool = true; 2969 kfree(trans->mem); 2970 } 2971 2972 if (!new_mem) 2973 return ERR_PTR(-BCH_ERR_ENOMEM_trans_kmalloc); 2974 2975 trans->mem = new_mem; 2976 trans->mem_bytes = new_bytes; 2977 2978 ret = bch2_trans_relock(trans); 2979 if (ret) 2980 return ERR_PTR(ret); 2981 } 2982 out_new_mem: 2983 trans->mem = new_mem; 2984 trans->mem_bytes = new_bytes; 2985 2986 if (old_bytes) { 2987 trace_and_count(c, trans_restart_mem_realloced, trans, _RET_IP_, new_bytes); 2988 return ERR_PTR(btree_trans_restart(trans, BCH_ERR_transaction_restart_mem_realloced)); 2989 } 2990 out_change_top: 2991 p = trans->mem + trans->mem_top; 2992 trans->mem_top += size; 2993 memset(p, 0, size); 2994 return p; 2995 } 2996 2997 static inline void check_srcu_held_too_long(struct btree_trans *trans) 2998 { 2999 WARN(trans->srcu_held && time_after(jiffies, trans->srcu_lock_time + HZ * 10), 3000 "btree trans held srcu lock (delaying memory reclaim) for %lu seconds", 3001 (jiffies - trans->srcu_lock_time) / HZ); 3002 } 3003 3004 void bch2_trans_srcu_unlock(struct btree_trans *trans) 3005 { 3006 if (trans->srcu_held) { 3007 struct bch_fs *c = trans->c; 3008 struct btree_path *path; 3009 unsigned i; 3010 3011 trans_for_each_path(trans, path, i) 3012 if (path->cached && !btree_node_locked(path, 0)) 3013 path->l[0].b = ERR_PTR(-BCH_ERR_no_btree_node_srcu_reset); 3014 3015 check_srcu_held_too_long(trans); 3016 srcu_read_unlock(&c->btree_trans_barrier, trans->srcu_idx); 3017 trans->srcu_held = false; 3018 } 3019 } 3020 3021 static void bch2_trans_srcu_lock(struct btree_trans *trans) 3022 { 3023 if (!trans->srcu_held) { 3024 trans->srcu_idx = srcu_read_lock(&trans->c->btree_trans_barrier); 3025 trans->srcu_lock_time = jiffies; 3026 trans->srcu_held = true; 3027 } 3028 } 3029 3030 /** 3031 * bch2_trans_begin() - reset a transaction after a interrupted attempt 3032 * @trans: transaction to reset 3033 * 3034 * Returns: current restart counter, to be used with trans_was_restarted() 3035 * 3036 * While iterating over nodes or updating nodes a attempt to lock a btree node 3037 * may return BCH_ERR_transaction_restart when the trylock fails. When this 3038 * occurs bch2_trans_begin() should be called and the transaction retried. 3039 */ 3040 u32 bch2_trans_begin(struct btree_trans *trans) 3041 { 3042 struct btree_path *path; 3043 unsigned i; 3044 u64 now; 3045 3046 bch2_trans_reset_updates(trans); 3047 3048 trans->restart_count++; 3049 trans->mem_top = 0; 3050 trans->journal_entries = NULL; 3051 3052 trans_for_each_path(trans, path, i) { 3053 path->should_be_locked = false; 3054 3055 /* 3056 * If the transaction wasn't restarted, we're presuming to be 3057 * doing something new: dont keep iterators excpt the ones that 3058 * are in use - except for the subvolumes btree: 3059 */ 3060 if (!trans->restarted && path->btree_id != BTREE_ID_subvolumes) 3061 path->preserve = false; 3062 3063 /* 3064 * XXX: we probably shouldn't be doing this if the transaction 3065 * was restarted, but currently we still overflow transaction 3066 * iterators if we do that 3067 */ 3068 if (!path->ref && !path->preserve) 3069 __bch2_path_free(trans, i); 3070 else 3071 path->preserve = false; 3072 } 3073 3074 now = local_clock(); 3075 3076 if (!IS_ENABLED(CONFIG_BCACHEFS_NO_LATENCY_ACCT) && 3077 time_after64(now, trans->last_begin_time + 10)) 3078 __bch2_time_stats_update(&btree_trans_stats(trans)->duration, 3079 trans->last_begin_time, now); 3080 3081 if (!trans->restarted && 3082 (need_resched() || 3083 time_after64(now, trans->last_begin_time + BTREE_TRANS_MAX_LOCK_HOLD_TIME_NS))) { 3084 bch2_trans_unlock(trans); 3085 cond_resched(); 3086 now = local_clock(); 3087 } 3088 trans->last_begin_time = now; 3089 3090 if (unlikely(trans->srcu_held && 3091 time_after(jiffies, trans->srcu_lock_time + msecs_to_jiffies(10)))) 3092 bch2_trans_srcu_unlock(trans); 3093 3094 trans->last_begin_ip = _RET_IP_; 3095 3096 trans_set_locked(trans); 3097 3098 if (trans->restarted) { 3099 bch2_btree_path_traverse_all(trans); 3100 trans->notrace_relock_fail = false; 3101 } 3102 3103 bch2_trans_verify_not_unlocked(trans); 3104 return trans->restart_count; 3105 } 3106 3107 const char *bch2_btree_transaction_fns[BCH_TRANSACTIONS_NR] = { "(unknown)" }; 3108 3109 unsigned bch2_trans_get_fn_idx(const char *fn) 3110 { 3111 for (unsigned i = 0; i < ARRAY_SIZE(bch2_btree_transaction_fns); i++) 3112 if (!bch2_btree_transaction_fns[i] || 3113 bch2_btree_transaction_fns[i] == fn) { 3114 bch2_btree_transaction_fns[i] = fn; 3115 return i; 3116 } 3117 3118 pr_warn_once("BCH_TRANSACTIONS_NR not big enough!"); 3119 return 0; 3120 } 3121 3122 struct btree_trans *__bch2_trans_get(struct bch_fs *c, unsigned fn_idx) 3123 __acquires(&c->btree_trans_barrier) 3124 { 3125 struct btree_trans *trans; 3126 3127 if (IS_ENABLED(__KERNEL__)) { 3128 trans = this_cpu_xchg(c->btree_trans_bufs->trans, NULL); 3129 if (trans) { 3130 memset(trans, 0, offsetof(struct btree_trans, list)); 3131 goto got_trans; 3132 } 3133 } 3134 3135 trans = mempool_alloc(&c->btree_trans_pool, GFP_NOFS); 3136 memset(trans, 0, sizeof(*trans)); 3137 3138 seqmutex_lock(&c->btree_trans_lock); 3139 if (IS_ENABLED(CONFIG_BCACHEFS_DEBUG)) { 3140 struct btree_trans *pos; 3141 pid_t pid = current->pid; 3142 3143 trans->locking_wait.task = current; 3144 3145 list_for_each_entry(pos, &c->btree_trans_list, list) { 3146 struct task_struct *pos_task = READ_ONCE(pos->locking_wait.task); 3147 /* 3148 * We'd much prefer to be stricter here and completely 3149 * disallow multiple btree_trans in the same thread - 3150 * but the data move path calls bch2_write when we 3151 * already have a btree_trans initialized. 3152 */ 3153 BUG_ON(pos_task && 3154 pid == pos_task->pid && 3155 pos->locked); 3156 } 3157 } 3158 3159 list_add(&trans->list, &c->btree_trans_list); 3160 seqmutex_unlock(&c->btree_trans_lock); 3161 got_trans: 3162 trans->c = c; 3163 trans->last_begin_time = local_clock(); 3164 trans->fn_idx = fn_idx; 3165 trans->locking_wait.task = current; 3166 trans->journal_replay_not_finished = 3167 unlikely(!test_bit(JOURNAL_replay_done, &c->journal.flags)) && 3168 atomic_inc_not_zero(&c->journal_keys.ref); 3169 trans->nr_paths = ARRAY_SIZE(trans->_paths); 3170 trans->paths_allocated = trans->_paths_allocated; 3171 trans->sorted = trans->_sorted; 3172 trans->paths = trans->_paths; 3173 trans->updates = trans->_updates; 3174 3175 *trans_paths_nr(trans->paths) = BTREE_ITER_INITIAL; 3176 3177 trans->paths_allocated[0] = 1; 3178 3179 static struct lock_class_key lockdep_key; 3180 lockdep_init_map(&trans->dep_map, "bcachefs_btree", &lockdep_key, 0); 3181 3182 if (fn_idx < BCH_TRANSACTIONS_NR) { 3183 trans->fn = bch2_btree_transaction_fns[fn_idx]; 3184 3185 struct btree_transaction_stats *s = &c->btree_transaction_stats[fn_idx]; 3186 3187 if (s->max_mem) { 3188 unsigned expected_mem_bytes = roundup_pow_of_two(s->max_mem); 3189 3190 trans->mem = kmalloc(expected_mem_bytes, GFP_KERNEL); 3191 if (likely(trans->mem)) 3192 trans->mem_bytes = expected_mem_bytes; 3193 } 3194 3195 trans->nr_paths_max = s->nr_max_paths; 3196 trans->journal_entries_size = s->journal_entries_size; 3197 } 3198 3199 trans->srcu_idx = srcu_read_lock(&c->btree_trans_barrier); 3200 trans->srcu_lock_time = jiffies; 3201 trans->srcu_held = true; 3202 trans_set_locked(trans); 3203 3204 closure_init_stack_release(&trans->ref); 3205 return trans; 3206 } 3207 3208 static void check_btree_paths_leaked(struct btree_trans *trans) 3209 { 3210 #ifdef CONFIG_BCACHEFS_DEBUG 3211 struct bch_fs *c = trans->c; 3212 struct btree_path *path; 3213 unsigned i; 3214 3215 trans_for_each_path(trans, path, i) 3216 if (path->ref) 3217 goto leaked; 3218 return; 3219 leaked: 3220 bch_err(c, "btree paths leaked from %s!", trans->fn); 3221 trans_for_each_path(trans, path, i) 3222 if (path->ref) 3223 printk(KERN_ERR " btree %s %pS\n", 3224 bch2_btree_id_str(path->btree_id), 3225 (void *) path->ip_allocated); 3226 /* Be noisy about this: */ 3227 bch2_fatal_error(c); 3228 #endif 3229 } 3230 3231 void bch2_trans_put(struct btree_trans *trans) 3232 __releases(&c->btree_trans_barrier) 3233 { 3234 struct bch_fs *c = trans->c; 3235 3236 bch2_trans_unlock(trans); 3237 3238 trans_for_each_update(trans, i) 3239 __btree_path_put(trans->paths + i->path, true); 3240 trans->nr_updates = 0; 3241 3242 check_btree_paths_leaked(trans); 3243 3244 if (trans->srcu_held) { 3245 check_srcu_held_too_long(trans); 3246 srcu_read_unlock(&c->btree_trans_barrier, trans->srcu_idx); 3247 } 3248 3249 if (unlikely(trans->journal_replay_not_finished)) 3250 bch2_journal_keys_put(c); 3251 3252 /* 3253 * trans->ref protects trans->locking_wait.task, btree_paths array; used 3254 * by cycle detector 3255 */ 3256 closure_return_sync(&trans->ref); 3257 trans->locking_wait.task = NULL; 3258 3259 unsigned long *paths_allocated = trans->paths_allocated; 3260 trans->paths_allocated = NULL; 3261 trans->paths = NULL; 3262 3263 if (paths_allocated != trans->_paths_allocated) 3264 kvfree_rcu_mightsleep(paths_allocated); 3265 3266 if (trans->used_mempool) 3267 mempool_free(trans->mem, &c->btree_trans_mem_pool); 3268 else 3269 kfree(trans->mem); 3270 3271 /* Userspace doesn't have a real percpu implementation: */ 3272 if (IS_ENABLED(__KERNEL__)) 3273 trans = this_cpu_xchg(c->btree_trans_bufs->trans, trans); 3274 3275 if (trans) { 3276 seqmutex_lock(&c->btree_trans_lock); 3277 list_del(&trans->list); 3278 seqmutex_unlock(&c->btree_trans_lock); 3279 3280 mempool_free(trans, &c->btree_trans_pool); 3281 } 3282 } 3283 3284 bool bch2_current_has_btree_trans(struct bch_fs *c) 3285 { 3286 seqmutex_lock(&c->btree_trans_lock); 3287 struct btree_trans *trans; 3288 bool ret = false; 3289 list_for_each_entry(trans, &c->btree_trans_list, list) 3290 if (trans->locking_wait.task == current && 3291 trans->locked) { 3292 ret = true; 3293 break; 3294 } 3295 seqmutex_unlock(&c->btree_trans_lock); 3296 return ret; 3297 } 3298 3299 static void __maybe_unused 3300 bch2_btree_bkey_cached_common_to_text(struct printbuf *out, 3301 struct btree_bkey_cached_common *b) 3302 { 3303 struct six_lock_count c = six_lock_counts(&b->lock); 3304 struct task_struct *owner; 3305 pid_t pid; 3306 3307 rcu_read_lock(); 3308 owner = READ_ONCE(b->lock.owner); 3309 pid = owner ? owner->pid : 0; 3310 rcu_read_unlock(); 3311 3312 prt_printf(out, "\t%px %c l=%u %s:", b, b->cached ? 'c' : 'b', 3313 b->level, bch2_btree_id_str(b->btree_id)); 3314 bch2_bpos_to_text(out, btree_node_pos(b)); 3315 3316 prt_printf(out, "\t locks %u:%u:%u held by pid %u", 3317 c.n[0], c.n[1], c.n[2], pid); 3318 } 3319 3320 void bch2_btree_trans_to_text(struct printbuf *out, struct btree_trans *trans) 3321 { 3322 struct btree_bkey_cached_common *b; 3323 static char lock_types[] = { 'r', 'i', 'w' }; 3324 struct task_struct *task = READ_ONCE(trans->locking_wait.task); 3325 unsigned l, idx; 3326 3327 /* before rcu_read_lock(): */ 3328 bch2_printbuf_make_room(out, 4096); 3329 3330 if (!out->nr_tabstops) { 3331 printbuf_tabstop_push(out, 16); 3332 printbuf_tabstop_push(out, 32); 3333 } 3334 3335 prt_printf(out, "%i %s\n", task ? task->pid : 0, trans->fn); 3336 3337 /* trans->paths is rcu protected vs. freeing */ 3338 rcu_read_lock(); 3339 out->atomic++; 3340 3341 struct btree_path *paths = rcu_dereference(trans->paths); 3342 if (!paths) 3343 goto out; 3344 3345 unsigned long *paths_allocated = trans_paths_allocated(paths); 3346 3347 trans_for_each_path_idx_from(paths_allocated, *trans_paths_nr(paths), idx, 1) { 3348 struct btree_path *path = paths + idx; 3349 if (!path->nodes_locked) 3350 continue; 3351 3352 prt_printf(out, " path %u %c l=%u %s:", 3353 idx, 3354 path->cached ? 'c' : 'b', 3355 path->level, 3356 bch2_btree_id_str(path->btree_id)); 3357 bch2_bpos_to_text(out, path->pos); 3358 prt_newline(out); 3359 3360 for (l = 0; l < BTREE_MAX_DEPTH; l++) { 3361 if (btree_node_locked(path, l) && 3362 !IS_ERR_OR_NULL(b = (void *) READ_ONCE(path->l[l].b))) { 3363 prt_printf(out, " %c l=%u ", 3364 lock_types[btree_node_locked_type(path, l)], l); 3365 bch2_btree_bkey_cached_common_to_text(out, b); 3366 prt_newline(out); 3367 } 3368 } 3369 } 3370 3371 b = READ_ONCE(trans->locking); 3372 if (b) { 3373 prt_printf(out, " blocked for %lluus on\n", 3374 div_u64(local_clock() - trans->locking_wait.start_time, 1000)); 3375 prt_printf(out, " %c", lock_types[trans->locking_wait.lock_want]); 3376 bch2_btree_bkey_cached_common_to_text(out, b); 3377 prt_newline(out); 3378 } 3379 out: 3380 --out->atomic; 3381 rcu_read_unlock(); 3382 } 3383 3384 void bch2_fs_btree_iter_exit(struct bch_fs *c) 3385 { 3386 struct btree_transaction_stats *s; 3387 struct btree_trans *trans; 3388 int cpu; 3389 3390 if (c->btree_trans_bufs) 3391 for_each_possible_cpu(cpu) { 3392 struct btree_trans *trans = 3393 per_cpu_ptr(c->btree_trans_bufs, cpu)->trans; 3394 3395 if (trans) { 3396 seqmutex_lock(&c->btree_trans_lock); 3397 list_del(&trans->list); 3398 seqmutex_unlock(&c->btree_trans_lock); 3399 } 3400 kfree(trans); 3401 } 3402 free_percpu(c->btree_trans_bufs); 3403 3404 trans = list_first_entry_or_null(&c->btree_trans_list, struct btree_trans, list); 3405 if (trans) 3406 panic("%s leaked btree_trans\n", trans->fn); 3407 3408 for (s = c->btree_transaction_stats; 3409 s < c->btree_transaction_stats + ARRAY_SIZE(c->btree_transaction_stats); 3410 s++) { 3411 kfree(s->max_paths_text); 3412 bch2_time_stats_exit(&s->lock_hold_times); 3413 } 3414 3415 if (c->btree_trans_barrier_initialized) { 3416 synchronize_srcu_expedited(&c->btree_trans_barrier); 3417 cleanup_srcu_struct(&c->btree_trans_barrier); 3418 } 3419 mempool_exit(&c->btree_trans_mem_pool); 3420 mempool_exit(&c->btree_trans_pool); 3421 } 3422 3423 void bch2_fs_btree_iter_init_early(struct bch_fs *c) 3424 { 3425 struct btree_transaction_stats *s; 3426 3427 for (s = c->btree_transaction_stats; 3428 s < c->btree_transaction_stats + ARRAY_SIZE(c->btree_transaction_stats); 3429 s++) { 3430 bch2_time_stats_init(&s->duration); 3431 bch2_time_stats_init(&s->lock_hold_times); 3432 mutex_init(&s->lock); 3433 } 3434 3435 INIT_LIST_HEAD(&c->btree_trans_list); 3436 seqmutex_init(&c->btree_trans_lock); 3437 } 3438 3439 int bch2_fs_btree_iter_init(struct bch_fs *c) 3440 { 3441 int ret; 3442 3443 c->btree_trans_bufs = alloc_percpu(struct btree_trans_buf); 3444 if (!c->btree_trans_bufs) 3445 return -ENOMEM; 3446 3447 ret = mempool_init_kmalloc_pool(&c->btree_trans_pool, 1, 3448 sizeof(struct btree_trans)) ?: 3449 mempool_init_kmalloc_pool(&c->btree_trans_mem_pool, 1, 3450 BTREE_TRANS_MEM_MAX) ?: 3451 init_srcu_struct(&c->btree_trans_barrier); 3452 if (ret) 3453 return ret; 3454 3455 /* 3456 * static annotation (hackily done) for lock ordering of reclaim vs. 3457 * btree node locks: 3458 */ 3459 #ifdef CONFIG_LOCKDEP 3460 fs_reclaim_acquire(GFP_KERNEL); 3461 struct btree_trans *trans = bch2_trans_get(c); 3462 trans_set_locked(trans); 3463 bch2_trans_put(trans); 3464 fs_reclaim_release(GFP_KERNEL); 3465 #endif 3466 3467 c->btree_trans_barrier_initialized = true; 3468 return 0; 3469 3470 } 3471