1// SPDX-License-Identifier: GPL-2.0 2 3#include "bcachefs.h" 4#include "btree_locking.h" 5#include "btree_types.h" 6 7static struct lock_class_key bch2_btree_node_lock_key; 8 9void bch2_btree_lock_init(struct btree_bkey_cached_common *b, 10 enum six_lock_init_flags flags) 11{ 12 __six_lock_init(&b->lock, "b->c.lock", &bch2_btree_node_lock_key, flags); 13 lockdep_set_novalidate_class(&b->lock); 14} 15 16#ifdef CONFIG_LOCKDEP 17void bch2_assert_btree_nodes_not_locked(void) 18{ 19#if 0 20 //Re-enable when lock_class_is_held() is merged: 21 BUG_ON(lock_class_is_held(&bch2_btree_node_lock_key)); 22#endif 23} 24#endif 25 26/* Btree node locking: */ 27 28struct six_lock_count bch2_btree_node_lock_counts(struct btree_trans *trans, 29 struct btree_path *skip, 30 struct btree_bkey_cached_common *b, 31 unsigned level) 32{ 33 struct btree_path *path; 34 struct six_lock_count ret; 35 unsigned i; 36 37 memset(&ret, 0, sizeof(ret)); 38 39 if (IS_ERR_OR_NULL(b)) 40 return ret; 41 42 trans_for_each_path(trans, path, i) 43 if (path != skip && &path->l[level].b->c == b) { 44 int t = btree_node_locked_type(path, level); 45 46 if (t != BTREE_NODE_UNLOCKED) 47 ret.n[t]++; 48 } 49 50 return ret; 51} 52 53/* unlock */ 54 55void bch2_btree_node_unlock_write(struct btree_trans *trans, 56 struct btree_path *path, struct btree *b) 57{ 58 bch2_btree_node_unlock_write_inlined(trans, path, b); 59} 60 61/* lock */ 62 63/* 64 * @trans wants to lock @b with type @type 65 */ 66struct trans_waiting_for_lock { 67 struct btree_trans *trans; 68 struct btree_bkey_cached_common *node_want; 69 enum six_lock_type lock_want; 70 71 /* for iterating over held locks :*/ 72 u8 path_idx; 73 u8 level; 74 u64 lock_start_time; 75}; 76 77struct lock_graph { 78 struct trans_waiting_for_lock g[8]; 79 unsigned nr; 80}; 81 82static noinline void print_cycle(struct printbuf *out, struct lock_graph *g) 83{ 84 struct trans_waiting_for_lock *i; 85 86 prt_printf(out, "Found lock cycle (%u entries):", g->nr); 87 prt_newline(out); 88 89 for (i = g->g; i < g->g + g->nr; i++) { 90 struct task_struct *task = READ_ONCE(i->trans->locking_wait.task); 91 if (!task) 92 continue; 93 94 bch2_btree_trans_to_text(out, i->trans); 95 bch2_prt_task_backtrace(out, task, i == g->g ? 5 : 1, GFP_NOWAIT); 96 } 97} 98 99static noinline void print_chain(struct printbuf *out, struct lock_graph *g) 100{ 101 struct trans_waiting_for_lock *i; 102 103 for (i = g->g; i != g->g + g->nr; i++) { 104 struct task_struct *task = i->trans->locking_wait.task; 105 if (i != g->g) 106 prt_str(out, "<- "); 107 prt_printf(out, "%u ", task ?task->pid : 0); 108 } 109 prt_newline(out); 110} 111 112static void lock_graph_up(struct lock_graph *g) 113{ 114 closure_put(&g->g[--g->nr].trans->ref); 115} 116 117static noinline void lock_graph_pop_all(struct lock_graph *g) 118{ 119 while (g->nr) 120 lock_graph_up(g); 121} 122 123static void __lock_graph_down(struct lock_graph *g, struct btree_trans *trans) 124{ 125 g->g[g->nr++] = (struct trans_waiting_for_lock) { 126 .trans = trans, 127 .node_want = trans->locking, 128 .lock_want = trans->locking_wait.lock_want, 129 }; 130} 131 132static void lock_graph_down(struct lock_graph *g, struct btree_trans *trans) 133{ 134 closure_get(&trans->ref); 135 __lock_graph_down(g, trans); 136} 137 138static bool lock_graph_remove_non_waiters(struct lock_graph *g) 139{ 140 struct trans_waiting_for_lock *i; 141 142 for (i = g->g + 1; i < g->g + g->nr; i++) 143 if (i->trans->locking != i->node_want || 144 i->trans->locking_wait.start_time != i[-1].lock_start_time) { 145 while (g->g + g->nr > i) 146 lock_graph_up(g); 147 return true; 148 } 149 150 return false; 151} 152 153static void trace_would_deadlock(struct lock_graph *g, struct btree_trans *trans) 154{ 155 struct bch_fs *c = trans->c; 156 157 count_event(c, trans_restart_would_deadlock); 158 159 if (trace_trans_restart_would_deadlock_enabled()) { 160 struct printbuf buf = PRINTBUF; 161 162 buf.atomic++; 163 print_cycle(&buf, g); 164 165 trace_trans_restart_would_deadlock(trans, buf.buf); 166 printbuf_exit(&buf); 167 } 168} 169 170static int abort_lock(struct lock_graph *g, struct trans_waiting_for_lock *i) 171{ 172 if (i == g->g) { 173 trace_would_deadlock(g, i->trans); 174 return btree_trans_restart(i->trans, BCH_ERR_transaction_restart_would_deadlock); 175 } else { 176 i->trans->lock_must_abort = true; 177 wake_up_process(i->trans->locking_wait.task); 178 return 0; 179 } 180} 181 182static int btree_trans_abort_preference(struct btree_trans *trans) 183{ 184 if (trans->lock_may_not_fail) 185 return 0; 186 if (trans->locking_wait.lock_want == SIX_LOCK_write) 187 return 1; 188 if (!trans->in_traverse_all) 189 return 2; 190 return 3; 191} 192 193static noinline int break_cycle(struct lock_graph *g, struct printbuf *cycle) 194{ 195 struct trans_waiting_for_lock *i, *abort = NULL; 196 unsigned best = 0, pref; 197 int ret; 198 199 if (lock_graph_remove_non_waiters(g)) 200 return 0; 201 202 /* Only checking, for debugfs: */ 203 if (cycle) { 204 print_cycle(cycle, g); 205 ret = -1; 206 goto out; 207 } 208 209 for (i = g->g; i < g->g + g->nr; i++) { 210 pref = btree_trans_abort_preference(i->trans); 211 if (pref > best) { 212 abort = i; 213 best = pref; 214 } 215 } 216 217 if (unlikely(!best)) { 218 struct printbuf buf = PRINTBUF; 219 220 prt_printf(&buf, bch2_fmt(g->g->trans->c, "cycle of nofail locks")); 221 222 for (i = g->g; i < g->g + g->nr; i++) { 223 struct btree_trans *trans = i->trans; 224 225 bch2_btree_trans_to_text(&buf, trans); 226 227 prt_printf(&buf, "backtrace:"); 228 prt_newline(&buf); 229 printbuf_indent_add(&buf, 2); 230 bch2_prt_task_backtrace(&buf, trans->locking_wait.task, 2, GFP_NOWAIT); 231 printbuf_indent_sub(&buf, 2); 232 prt_newline(&buf); 233 } 234 235 bch2_print_string_as_lines(KERN_ERR, buf.buf); 236 printbuf_exit(&buf); 237 BUG(); 238 } 239 240 ret = abort_lock(g, abort); 241out: 242 if (ret) 243 while (g->nr) 244 lock_graph_up(g); 245 return ret; 246} 247 248static int lock_graph_descend(struct lock_graph *g, struct btree_trans *trans, 249 struct printbuf *cycle) 250{ 251 struct btree_trans *orig_trans = g->g->trans; 252 struct trans_waiting_for_lock *i; 253 254 for (i = g->g; i < g->g + g->nr; i++) 255 if (i->trans == trans) { 256 closure_put(&trans->ref); 257 return break_cycle(g, cycle); 258 } 259 260 if (g->nr == ARRAY_SIZE(g->g)) { 261 closure_put(&trans->ref); 262 263 if (orig_trans->lock_may_not_fail) 264 return 0; 265 266 while (g->nr) 267 lock_graph_up(g); 268 269 if (cycle) 270 return 0; 271 272 trace_and_count(trans->c, trans_restart_would_deadlock_recursion_limit, trans, _RET_IP_); 273 return btree_trans_restart(orig_trans, BCH_ERR_transaction_restart_deadlock_recursion_limit); 274 } 275 276 __lock_graph_down(g, trans); 277 return 0; 278} 279 280static bool lock_type_conflicts(enum six_lock_type t1, enum six_lock_type t2) 281{ 282 return t1 + t2 > 1; 283} 284 285int bch2_check_for_deadlock(struct btree_trans *trans, struct printbuf *cycle) 286{ 287 struct lock_graph g; 288 struct trans_waiting_for_lock *top; 289 struct btree_bkey_cached_common *b; 290 btree_path_idx_t path_idx; 291 int ret = 0; 292 293 g.nr = 0; 294 295 if (trans->lock_must_abort) { 296 if (cycle) 297 return -1; 298 299 trace_would_deadlock(&g, trans); 300 return btree_trans_restart(trans, BCH_ERR_transaction_restart_would_deadlock); 301 } 302 303 lock_graph_down(&g, trans); 304 305 /* trans->paths is rcu protected vs. freeing */ 306 rcu_read_lock(); 307 if (cycle) 308 cycle->atomic++; 309next: 310 if (!g.nr) 311 goto out; 312 313 top = &g.g[g.nr - 1]; 314 315 struct btree_path *paths = rcu_dereference(top->trans->paths); 316 if (!paths) 317 goto up; 318 319 unsigned long *paths_allocated = trans_paths_allocated(paths); 320 321 trans_for_each_path_idx_from(paths_allocated, *trans_paths_nr(paths), 322 path_idx, top->path_idx) { 323 struct btree_path *path = paths + path_idx; 324 if (!path->nodes_locked) 325 continue; 326 327 if (path_idx != top->path_idx) { 328 top->path_idx = path_idx; 329 top->level = 0; 330 top->lock_start_time = 0; 331 } 332 333 for (; 334 top->level < BTREE_MAX_DEPTH; 335 top->level++, top->lock_start_time = 0) { 336 int lock_held = btree_node_locked_type(path, top->level); 337 338 if (lock_held == BTREE_NODE_UNLOCKED) 339 continue; 340 341 b = &READ_ONCE(path->l[top->level].b)->c; 342 343 if (IS_ERR_OR_NULL(b)) { 344 /* 345 * If we get here, it means we raced with the 346 * other thread updating its btree_path 347 * structures - which means it can't be blocked 348 * waiting on a lock: 349 */ 350 if (!lock_graph_remove_non_waiters(&g)) { 351 /* 352 * If lock_graph_remove_non_waiters() 353 * didn't do anything, it must be 354 * because we're being called by debugfs 355 * checking for lock cycles, which 356 * invokes us on btree_transactions that 357 * aren't actually waiting on anything. 358 * Just bail out: 359 */ 360 lock_graph_pop_all(&g); 361 } 362 363 goto next; 364 } 365 366 if (list_empty_careful(&b->lock.wait_list)) 367 continue; 368 369 raw_spin_lock(&b->lock.wait_lock); 370 list_for_each_entry(trans, &b->lock.wait_list, locking_wait.list) { 371 BUG_ON(b != trans->locking); 372 373 if (top->lock_start_time && 374 time_after_eq64(top->lock_start_time, trans->locking_wait.start_time)) 375 continue; 376 377 top->lock_start_time = trans->locking_wait.start_time; 378 379 /* Don't check for self deadlock: */ 380 if (trans == top->trans || 381 !lock_type_conflicts(lock_held, trans->locking_wait.lock_want)) 382 continue; 383 384 closure_get(&trans->ref); 385 raw_spin_unlock(&b->lock.wait_lock); 386 387 ret = lock_graph_descend(&g, trans, cycle); 388 if (ret) 389 goto out; 390 goto next; 391 392 } 393 raw_spin_unlock(&b->lock.wait_lock); 394 } 395 } 396up: 397 if (g.nr > 1 && cycle) 398 print_chain(cycle, &g); 399 lock_graph_up(&g); 400 goto next; 401out: 402 if (cycle) 403 --cycle->atomic; 404 rcu_read_unlock(); 405 return ret; 406} 407 408int bch2_six_check_for_deadlock(struct six_lock *lock, void *p) 409{ 410 struct btree_trans *trans = p; 411 412 return bch2_check_for_deadlock(trans, NULL); 413} 414 415int __bch2_btree_node_lock_write(struct btree_trans *trans, struct btree_path *path, 416 struct btree_bkey_cached_common *b, 417 bool lock_may_not_fail) 418{ 419 int readers = bch2_btree_node_lock_counts(trans, NULL, b, b->level).n[SIX_LOCK_read]; 420 int ret; 421 422 /* 423 * Must drop our read locks before calling six_lock_write() - 424 * six_unlock() won't do wakeups until the reader count 425 * goes to 0, and it's safe because we have the node intent 426 * locked: 427 */ 428 six_lock_readers_add(&b->lock, -readers); 429 ret = __btree_node_lock_nopath(trans, b, SIX_LOCK_write, 430 lock_may_not_fail, _RET_IP_); 431 six_lock_readers_add(&b->lock, readers); 432 433 if (ret) 434 mark_btree_node_locked_noreset(path, b->level, BTREE_NODE_INTENT_LOCKED); 435 436 return ret; 437} 438 439void bch2_btree_node_lock_write_nofail(struct btree_trans *trans, 440 struct btree_path *path, 441 struct btree_bkey_cached_common *b) 442{ 443 int ret = __btree_node_lock_write(trans, path, b, true); 444 BUG_ON(ret); 445} 446 447/* relock */ 448 449static inline bool btree_path_get_locks(struct btree_trans *trans, 450 struct btree_path *path, 451 bool upgrade, 452 struct get_locks_fail *f) 453{ 454 unsigned l = path->level; 455 int fail_idx = -1; 456 457 do { 458 if (!btree_path_node(path, l)) 459 break; 460 461 if (!(upgrade 462 ? bch2_btree_node_upgrade(trans, path, l) 463 : bch2_btree_node_relock(trans, path, l))) { 464 fail_idx = l; 465 466 if (f) { 467 f->l = l; 468 f->b = path->l[l].b; 469 } 470 } 471 472 l++; 473 } while (l < path->locks_want); 474 475 /* 476 * When we fail to get a lock, we have to ensure that any child nodes 477 * can't be relocked so bch2_btree_path_traverse has to walk back up to 478 * the node that we failed to relock: 479 */ 480 if (fail_idx >= 0) { 481 __bch2_btree_path_unlock(trans, path); 482 btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE); 483 484 do { 485 path->l[fail_idx].b = upgrade 486 ? ERR_PTR(-BCH_ERR_no_btree_node_upgrade) 487 : ERR_PTR(-BCH_ERR_no_btree_node_relock); 488 --fail_idx; 489 } while (fail_idx >= 0); 490 } 491 492 if (path->uptodate == BTREE_ITER_NEED_RELOCK) 493 path->uptodate = BTREE_ITER_UPTODATE; 494 495 bch2_trans_verify_locks(trans); 496 497 return path->uptodate < BTREE_ITER_NEED_RELOCK; 498} 499 500bool __bch2_btree_node_relock(struct btree_trans *trans, 501 struct btree_path *path, unsigned level, 502 bool trace) 503{ 504 struct btree *b = btree_path_node(path, level); 505 int want = __btree_lock_want(path, level); 506 507 if (race_fault()) 508 goto fail; 509 510 if (six_relock_type(&b->c.lock, want, path->l[level].lock_seq) || 511 (btree_node_lock_seq_matches(path, b, level) && 512 btree_node_lock_increment(trans, &b->c, level, want))) { 513 mark_btree_node_locked(trans, path, level, want); 514 return true; 515 } 516fail: 517 if (trace && !trans->notrace_relock_fail) 518 trace_and_count(trans->c, btree_path_relock_fail, trans, _RET_IP_, path, level); 519 return false; 520} 521 522/* upgrade */ 523 524bool bch2_btree_node_upgrade(struct btree_trans *trans, 525 struct btree_path *path, unsigned level) 526{ 527 struct btree *b = path->l[level].b; 528 struct six_lock_count count = bch2_btree_node_lock_counts(trans, path, &b->c, level); 529 530 if (!is_btree_node(path, level)) 531 return false; 532 533 switch (btree_lock_want(path, level)) { 534 case BTREE_NODE_UNLOCKED: 535 BUG_ON(btree_node_locked(path, level)); 536 return true; 537 case BTREE_NODE_READ_LOCKED: 538 BUG_ON(btree_node_intent_locked(path, level)); 539 return bch2_btree_node_relock(trans, path, level); 540 case BTREE_NODE_INTENT_LOCKED: 541 break; 542 case BTREE_NODE_WRITE_LOCKED: 543 BUG(); 544 } 545 546 if (btree_node_intent_locked(path, level)) 547 return true; 548 549 if (race_fault()) 550 return false; 551 552 if (btree_node_locked(path, level)) { 553 bool ret; 554 555 six_lock_readers_add(&b->c.lock, -count.n[SIX_LOCK_read]); 556 ret = six_lock_tryupgrade(&b->c.lock); 557 six_lock_readers_add(&b->c.lock, count.n[SIX_LOCK_read]); 558 559 if (ret) 560 goto success; 561 } else { 562 if (six_relock_type(&b->c.lock, SIX_LOCK_intent, path->l[level].lock_seq)) 563 goto success; 564 } 565 566 /* 567 * Do we already have an intent lock via another path? If so, just bump 568 * lock count: 569 */ 570 if (btree_node_lock_seq_matches(path, b, level) && 571 btree_node_lock_increment(trans, &b->c, level, BTREE_NODE_INTENT_LOCKED)) { 572 btree_node_unlock(trans, path, level); 573 goto success; 574 } 575 576 trace_and_count(trans->c, btree_path_upgrade_fail, trans, _RET_IP_, path, level); 577 return false; 578success: 579 mark_btree_node_locked_noreset(path, level, BTREE_NODE_INTENT_LOCKED); 580 return true; 581} 582 583/* Btree path locking: */ 584 585/* 586 * Only for btree_cache.c - only relocks intent locks 587 */ 588int bch2_btree_path_relock_intent(struct btree_trans *trans, 589 struct btree_path *path) 590{ 591 unsigned l; 592 593 for (l = path->level; 594 l < path->locks_want && btree_path_node(path, l); 595 l++) { 596 if (!bch2_btree_node_relock(trans, path, l)) { 597 __bch2_btree_path_unlock(trans, path); 598 btree_path_set_dirty(path, BTREE_ITER_NEED_TRAVERSE); 599 trace_and_count(trans->c, trans_restart_relock_path_intent, trans, _RET_IP_, path); 600 return btree_trans_restart(trans, BCH_ERR_transaction_restart_relock_path_intent); 601 } 602 } 603 604 return 0; 605} 606 607__flatten 608bool bch2_btree_path_relock_norestart(struct btree_trans *trans, struct btree_path *path) 609{ 610 struct get_locks_fail f; 611 612 return btree_path_get_locks(trans, path, false, &f); 613} 614 615int __bch2_btree_path_relock(struct btree_trans *trans, 616 struct btree_path *path, unsigned long trace_ip) 617{ 618 if (!bch2_btree_path_relock_norestart(trans, path)) { 619 trace_and_count(trans->c, trans_restart_relock_path, trans, trace_ip, path); 620 return btree_trans_restart(trans, BCH_ERR_transaction_restart_relock_path); 621 } 622 623 return 0; 624} 625 626bool bch2_btree_path_upgrade_noupgrade_sibs(struct btree_trans *trans, 627 struct btree_path *path, 628 unsigned new_locks_want, 629 struct get_locks_fail *f) 630{ 631 EBUG_ON(path->locks_want >= new_locks_want); 632 633 path->locks_want = new_locks_want; 634 635 return btree_path_get_locks(trans, path, true, f); 636} 637 638bool __bch2_btree_path_upgrade(struct btree_trans *trans, 639 struct btree_path *path, 640 unsigned new_locks_want, 641 struct get_locks_fail *f) 642{ 643 if (bch2_btree_path_upgrade_noupgrade_sibs(trans, path, new_locks_want, f)) 644 return true; 645 646 /* 647 * XXX: this is ugly - we'd prefer to not be mucking with other 648 * iterators in the btree_trans here. 649 * 650 * On failure to upgrade the iterator, setting iter->locks_want and 651 * calling get_locks() is sufficient to make bch2_btree_path_traverse() 652 * get the locks we want on transaction restart. 653 * 654 * But if this iterator was a clone, on transaction restart what we did 655 * to this iterator isn't going to be preserved. 656 * 657 * Possibly we could add an iterator field for the parent iterator when 658 * an iterator is a copy - for now, we'll just upgrade any other 659 * iterators with the same btree id. 660 * 661 * The code below used to be needed to ensure ancestor nodes get locked 662 * before interior nodes - now that's handled by 663 * bch2_btree_path_traverse_all(). 664 */ 665 if (!path->cached && !trans->in_traverse_all) { 666 struct btree_path *linked; 667 unsigned i; 668 669 trans_for_each_path(trans, linked, i) 670 if (linked != path && 671 linked->cached == path->cached && 672 linked->btree_id == path->btree_id && 673 linked->locks_want < new_locks_want) { 674 linked->locks_want = new_locks_want; 675 btree_path_get_locks(trans, linked, true, NULL); 676 } 677 } 678 679 return false; 680} 681 682void __bch2_btree_path_downgrade(struct btree_trans *trans, 683 struct btree_path *path, 684 unsigned new_locks_want) 685{ 686 unsigned l, old_locks_want = path->locks_want; 687 688 if (trans->restarted) 689 return; 690 691 EBUG_ON(path->locks_want < new_locks_want); 692 693 path->locks_want = new_locks_want; 694 695 while (path->nodes_locked && 696 (l = btree_path_highest_level_locked(path)) >= path->locks_want) { 697 if (l > path->level) { 698 btree_node_unlock(trans, path, l); 699 } else { 700 if (btree_node_intent_locked(path, l)) { 701 six_lock_downgrade(&path->l[l].b->c.lock); 702 mark_btree_node_locked_noreset(path, l, BTREE_NODE_READ_LOCKED); 703 } 704 break; 705 } 706 } 707 708 bch2_btree_path_verify_locks(path); 709 710 trace_path_downgrade(trans, _RET_IP_, path, old_locks_want); 711} 712 713/* Btree transaction locking: */ 714 715void bch2_trans_downgrade(struct btree_trans *trans) 716{ 717 struct btree_path *path; 718 unsigned i; 719 720 if (trans->restarted) 721 return; 722 723 trans_for_each_path(trans, path, i) 724 if (path->ref) 725 bch2_btree_path_downgrade(trans, path); 726} 727 728int bch2_trans_relock(struct btree_trans *trans) 729{ 730 struct btree_path *path; 731 unsigned i; 732 733 if (unlikely(trans->restarted)) 734 return -((int) trans->restarted); 735 736 trans_for_each_path(trans, path, i) { 737 struct get_locks_fail f; 738 739 if (path->should_be_locked && 740 !btree_path_get_locks(trans, path, false, &f)) { 741 if (trace_trans_restart_relock_enabled()) { 742 struct printbuf buf = PRINTBUF; 743 744 bch2_bpos_to_text(&buf, path->pos); 745 prt_printf(&buf, " l=%u seq=%u node seq=", 746 f.l, path->l[f.l].lock_seq); 747 if (IS_ERR_OR_NULL(f.b)) { 748 prt_str(&buf, bch2_err_str(PTR_ERR(f.b))); 749 } else { 750 prt_printf(&buf, "%u", f.b->c.lock.seq); 751 752 struct six_lock_count c = 753 bch2_btree_node_lock_counts(trans, NULL, &f.b->c, f.l); 754 prt_printf(&buf, " self locked %u.%u.%u", c.n[0], c.n[1], c.n[2]); 755 756 c = six_lock_counts(&f.b->c.lock); 757 prt_printf(&buf, " total locked %u.%u.%u", c.n[0], c.n[1], c.n[2]); 758 } 759 760 trace_trans_restart_relock(trans, _RET_IP_, buf.buf); 761 printbuf_exit(&buf); 762 } 763 764 count_event(trans->c, trans_restart_relock); 765 return btree_trans_restart(trans, BCH_ERR_transaction_restart_relock); 766 } 767 } 768 769 return 0; 770} 771 772int bch2_trans_relock_notrace(struct btree_trans *trans) 773{ 774 struct btree_path *path; 775 unsigned i; 776 777 if (unlikely(trans->restarted)) 778 return -((int) trans->restarted); 779 780 trans_for_each_path(trans, path, i) 781 if (path->should_be_locked && 782 !bch2_btree_path_relock_norestart(trans, path)) { 783 return btree_trans_restart(trans, BCH_ERR_transaction_restart_relock); 784 } 785 return 0; 786} 787 788void bch2_trans_unlock_noassert(struct btree_trans *trans) 789{ 790 struct btree_path *path; 791 unsigned i; 792 793 trans_for_each_path(trans, path, i) 794 __bch2_btree_path_unlock(trans, path); 795} 796 797void bch2_trans_unlock(struct btree_trans *trans) 798{ 799 struct btree_path *path; 800 unsigned i; 801 802 trans_for_each_path(trans, path, i) 803 __bch2_btree_path_unlock(trans, path); 804} 805 806void bch2_trans_unlock_long(struct btree_trans *trans) 807{ 808 bch2_trans_unlock(trans); 809 bch2_trans_srcu_unlock(trans); 810} 811 812bool bch2_trans_locked(struct btree_trans *trans) 813{ 814 struct btree_path *path; 815 unsigned i; 816 817 trans_for_each_path(trans, path, i) 818 if (path->nodes_locked) 819 return true; 820 return false; 821} 822 823int __bch2_trans_mutex_lock(struct btree_trans *trans, 824 struct mutex *lock) 825{ 826 int ret = drop_locks_do(trans, (mutex_lock(lock), 0)); 827 828 if (ret) 829 mutex_unlock(lock); 830 return ret; 831} 832 833/* Debug */ 834 835#ifdef CONFIG_BCACHEFS_DEBUG 836 837void bch2_btree_path_verify_locks(struct btree_path *path) 838{ 839 unsigned l; 840 841 if (!path->nodes_locked) { 842 BUG_ON(path->uptodate == BTREE_ITER_UPTODATE && 843 btree_path_node(path, path->level)); 844 return; 845 } 846 847 for (l = 0; l < BTREE_MAX_DEPTH; l++) { 848 int want = btree_lock_want(path, l); 849 int have = btree_node_locked_type(path, l); 850 851 BUG_ON(!is_btree_node(path, l) && have != BTREE_NODE_UNLOCKED); 852 853 BUG_ON(is_btree_node(path, l) && 854 (want == BTREE_NODE_UNLOCKED || 855 have != BTREE_NODE_WRITE_LOCKED) && 856 want != have); 857 } 858} 859 860void bch2_trans_verify_locks(struct btree_trans *trans) 861{ 862 struct btree_path *path; 863 unsigned i; 864 865 trans_for_each_path(trans, path, i) 866 bch2_btree_path_verify_locks(path); 867} 868 869#endif 870