1 // SPDX-License-Identifier: GPL-2.0 2 #include "bcachefs.h" 3 #include "bbpos.h" 4 #include "alloc_background.h" 5 #include "backpointers.h" 6 #include "btree_cache.h" 7 #include "btree_update.h" 8 #include "btree_write_buffer.h" 9 #include "error.h" 10 11 #include <linux/mm.h> 12 13 static bool extent_matches_bp(struct bch_fs *c, 14 enum btree_id btree_id, unsigned level, 15 struct bkey_s_c k, 16 struct bpos bucket, 17 struct bch_backpointer bp) 18 { 19 struct bkey_ptrs_c ptrs = bch2_bkey_ptrs_c(k); 20 const union bch_extent_entry *entry; 21 struct extent_ptr_decoded p; 22 23 bkey_for_each_ptr_decode(k.k, ptrs, p, entry) { 24 struct bpos bucket2; 25 struct bch_backpointer bp2; 26 27 if (p.ptr.cached) 28 continue; 29 30 bch2_extent_ptr_to_bp(c, btree_id, level, k, p, 31 &bucket2, &bp2); 32 if (bpos_eq(bucket, bucket2) && 33 !memcmp(&bp, &bp2, sizeof(bp))) 34 return true; 35 } 36 37 return false; 38 } 39 40 int bch2_backpointer_invalid(const struct bch_fs *c, struct bkey_s_c k, 41 enum bkey_invalid_flags flags, 42 struct printbuf *err) 43 { 44 struct bkey_s_c_backpointer bp = bkey_s_c_to_backpointer(k); 45 struct bpos bucket = bp_pos_to_bucket(c, bp.k->p); 46 47 if (!bpos_eq(bp.k->p, bucket_pos_to_bp(c, bucket, bp.v->bucket_offset))) { 48 prt_str(err, "backpointer at wrong pos"); 49 return -BCH_ERR_invalid_bkey; 50 } 51 52 return 0; 53 } 54 55 void bch2_backpointer_to_text(struct printbuf *out, const struct bch_backpointer *bp) 56 { 57 prt_printf(out, "btree=%s l=%u offset=%llu:%u len=%u pos=", 58 bch2_btree_ids[bp->btree_id], 59 bp->level, 60 (u64) (bp->bucket_offset >> MAX_EXTENT_COMPRESS_RATIO_SHIFT), 61 (u32) bp->bucket_offset & ~(~0U << MAX_EXTENT_COMPRESS_RATIO_SHIFT), 62 bp->bucket_len); 63 bch2_bpos_to_text(out, bp->pos); 64 } 65 66 void bch2_backpointer_k_to_text(struct printbuf *out, struct bch_fs *c, struct bkey_s_c k) 67 { 68 prt_str(out, "bucket="); 69 bch2_bpos_to_text(out, bp_pos_to_bucket(c, k.k->p)); 70 prt_str(out, " "); 71 72 bch2_backpointer_to_text(out, bkey_s_c_to_backpointer(k).v); 73 } 74 75 void bch2_backpointer_swab(struct bkey_s k) 76 { 77 struct bkey_s_backpointer bp = bkey_s_to_backpointer(k); 78 79 bp.v->bucket_offset = swab32(bp.v->bucket_offset); 80 bp.v->bucket_len = swab32(bp.v->bucket_len); 81 bch2_bpos_swab(&bp.v->pos); 82 } 83 84 static noinline int backpointer_mod_err(struct btree_trans *trans, 85 struct bch_backpointer bp, 86 struct bkey_s_c bp_k, 87 struct bkey_s_c orig_k, 88 bool insert) 89 { 90 struct bch_fs *c = trans->c; 91 struct printbuf buf = PRINTBUF; 92 93 if (insert) { 94 prt_printf(&buf, "existing backpointer found when inserting "); 95 bch2_backpointer_to_text(&buf, &bp); 96 prt_newline(&buf); 97 printbuf_indent_add(&buf, 2); 98 99 prt_printf(&buf, "found "); 100 bch2_bkey_val_to_text(&buf, c, bp_k); 101 prt_newline(&buf); 102 103 prt_printf(&buf, "for "); 104 bch2_bkey_val_to_text(&buf, c, orig_k); 105 106 bch_err(c, "%s", buf.buf); 107 } else if (c->curr_recovery_pass > BCH_RECOVERY_PASS_check_extents_to_backpointers) { 108 prt_printf(&buf, "backpointer not found when deleting"); 109 prt_newline(&buf); 110 printbuf_indent_add(&buf, 2); 111 112 prt_printf(&buf, "searching for "); 113 bch2_backpointer_to_text(&buf, &bp); 114 prt_newline(&buf); 115 116 prt_printf(&buf, "got "); 117 bch2_bkey_val_to_text(&buf, c, bp_k); 118 prt_newline(&buf); 119 120 prt_printf(&buf, "for "); 121 bch2_bkey_val_to_text(&buf, c, orig_k); 122 123 bch_err(c, "%s", buf.buf); 124 } 125 126 printbuf_exit(&buf); 127 128 if (c->curr_recovery_pass > BCH_RECOVERY_PASS_check_extents_to_backpointers) { 129 bch2_inconsistent_error(c); 130 return -EIO; 131 } else { 132 return 0; 133 } 134 } 135 136 int bch2_bucket_backpointer_mod_nowritebuffer(struct btree_trans *trans, 137 struct bkey_i_backpointer *bp_k, 138 struct bch_backpointer bp, 139 struct bkey_s_c orig_k, 140 bool insert) 141 { 142 struct btree_iter bp_iter; 143 struct bkey_s_c k; 144 int ret; 145 146 k = bch2_bkey_get_iter(trans, &bp_iter, BTREE_ID_backpointers, 147 bp_k->k.p, 148 BTREE_ITER_INTENT| 149 BTREE_ITER_SLOTS| 150 BTREE_ITER_WITH_UPDATES); 151 ret = bkey_err(k); 152 if (ret) 153 goto err; 154 155 if (insert 156 ? k.k->type 157 : (k.k->type != KEY_TYPE_backpointer || 158 memcmp(bkey_s_c_to_backpointer(k).v, &bp, sizeof(bp)))) { 159 ret = backpointer_mod_err(trans, bp, k, orig_k, insert); 160 if (ret) 161 goto err; 162 } 163 164 ret = bch2_trans_update(trans, &bp_iter, &bp_k->k_i, 0); 165 err: 166 bch2_trans_iter_exit(trans, &bp_iter); 167 return ret; 168 } 169 170 /* 171 * Find the next backpointer >= *bp_offset: 172 */ 173 int bch2_get_next_backpointer(struct btree_trans *trans, 174 struct bpos bucket, int gen, 175 struct bpos *bp_pos, 176 struct bch_backpointer *bp, 177 unsigned iter_flags) 178 { 179 struct bch_fs *c = trans->c; 180 struct bpos bp_end_pos = bucket_pos_to_bp(c, bpos_nosnap_successor(bucket), 0); 181 struct btree_iter alloc_iter = { NULL }, bp_iter = { NULL }; 182 struct bkey_s_c k; 183 int ret = 0; 184 185 if (bpos_ge(*bp_pos, bp_end_pos)) 186 goto done; 187 188 if (gen >= 0) { 189 k = bch2_bkey_get_iter(trans, &alloc_iter, BTREE_ID_alloc, 190 bucket, BTREE_ITER_CACHED|iter_flags); 191 ret = bkey_err(k); 192 if (ret) 193 goto out; 194 195 if (k.k->type != KEY_TYPE_alloc_v4 || 196 bkey_s_c_to_alloc_v4(k).v->gen != gen) 197 goto done; 198 } 199 200 *bp_pos = bpos_max(*bp_pos, bucket_pos_to_bp(c, bucket, 0)); 201 202 for_each_btree_key_norestart(trans, bp_iter, BTREE_ID_backpointers, 203 *bp_pos, iter_flags, k, ret) { 204 if (bpos_ge(k.k->p, bp_end_pos)) 205 break; 206 207 *bp_pos = k.k->p; 208 *bp = *bkey_s_c_to_backpointer(k).v; 209 goto out; 210 } 211 done: 212 *bp_pos = SPOS_MAX; 213 out: 214 bch2_trans_iter_exit(trans, &bp_iter); 215 bch2_trans_iter_exit(trans, &alloc_iter); 216 return ret; 217 } 218 219 static void backpointer_not_found(struct btree_trans *trans, 220 struct bpos bp_pos, 221 struct bch_backpointer bp, 222 struct bkey_s_c k, 223 const char *thing_it_points_to) 224 { 225 struct bch_fs *c = trans->c; 226 struct printbuf buf = PRINTBUF; 227 struct bpos bucket = bp_pos_to_bucket(c, bp_pos); 228 229 if (likely(!bch2_backpointers_no_use_write_buffer)) 230 return; 231 232 prt_printf(&buf, "backpointer doesn't match %s it points to:\n ", 233 thing_it_points_to); 234 prt_printf(&buf, "bucket: "); 235 bch2_bpos_to_text(&buf, bucket); 236 prt_printf(&buf, "\n "); 237 238 prt_printf(&buf, "backpointer pos: "); 239 bch2_bpos_to_text(&buf, bp_pos); 240 prt_printf(&buf, "\n "); 241 242 bch2_backpointer_to_text(&buf, &bp); 243 prt_printf(&buf, "\n "); 244 bch2_bkey_val_to_text(&buf, c, k); 245 if (c->curr_recovery_pass >= BCH_RECOVERY_PASS_check_extents_to_backpointers) 246 bch_err_ratelimited(c, "%s", buf.buf); 247 else 248 bch2_trans_inconsistent(trans, "%s", buf.buf); 249 250 printbuf_exit(&buf); 251 } 252 253 struct bkey_s_c bch2_backpointer_get_key(struct btree_trans *trans, 254 struct btree_iter *iter, 255 struct bpos bp_pos, 256 struct bch_backpointer bp, 257 unsigned iter_flags) 258 { 259 struct bch_fs *c = trans->c; 260 struct btree_root *r = bch2_btree_id_root(c, bp.btree_id); 261 struct bpos bucket = bp_pos_to_bucket(c, bp_pos); 262 struct bkey_s_c k; 263 264 bch2_trans_node_iter_init(trans, iter, 265 bp.btree_id, 266 bp.pos, 267 0, 268 min(bp.level, r->level), 269 iter_flags); 270 k = bch2_btree_iter_peek_slot(iter); 271 if (bkey_err(k)) { 272 bch2_trans_iter_exit(trans, iter); 273 return k; 274 } 275 276 if (bp.level == r->level + 1) 277 k = bkey_i_to_s_c(&r->key); 278 279 if (k.k && extent_matches_bp(c, bp.btree_id, bp.level, k, bucket, bp)) 280 return k; 281 282 bch2_trans_iter_exit(trans, iter); 283 284 if (unlikely(bch2_backpointers_no_use_write_buffer)) { 285 if (bp.level) { 286 struct btree *b; 287 288 /* 289 * If a backpointer for a btree node wasn't found, it may be 290 * because it was overwritten by a new btree node that hasn't 291 * been written out yet - backpointer_get_node() checks for 292 * this: 293 */ 294 b = bch2_backpointer_get_node(trans, iter, bp_pos, bp); 295 if (!IS_ERR_OR_NULL(b)) 296 return bkey_i_to_s_c(&b->key); 297 298 bch2_trans_iter_exit(trans, iter); 299 300 if (IS_ERR(b)) 301 return bkey_s_c_err(PTR_ERR(b)); 302 return bkey_s_c_null; 303 } 304 305 backpointer_not_found(trans, bp_pos, bp, k, "extent"); 306 } 307 308 return bkey_s_c_null; 309 } 310 311 struct btree *bch2_backpointer_get_node(struct btree_trans *trans, 312 struct btree_iter *iter, 313 struct bpos bp_pos, 314 struct bch_backpointer bp) 315 { 316 struct bch_fs *c = trans->c; 317 struct bpos bucket = bp_pos_to_bucket(c, bp_pos); 318 struct btree *b; 319 320 BUG_ON(!bp.level); 321 322 bch2_trans_node_iter_init(trans, iter, 323 bp.btree_id, 324 bp.pos, 325 0, 326 bp.level - 1, 327 0); 328 b = bch2_btree_iter_peek_node(iter); 329 if (IS_ERR(b)) 330 goto err; 331 332 if (b && extent_matches_bp(c, bp.btree_id, bp.level, 333 bkey_i_to_s_c(&b->key), 334 bucket, bp)) 335 return b; 336 337 if (b && btree_node_will_make_reachable(b)) { 338 b = ERR_PTR(-BCH_ERR_backpointer_to_overwritten_btree_node); 339 } else { 340 backpointer_not_found(trans, bp_pos, bp, 341 bkey_i_to_s_c(&b->key), "btree node"); 342 b = NULL; 343 } 344 err: 345 bch2_trans_iter_exit(trans, iter); 346 return b; 347 } 348 349 static int bch2_check_btree_backpointer(struct btree_trans *trans, struct btree_iter *bp_iter, 350 struct bkey_s_c k) 351 { 352 struct bch_fs *c = trans->c; 353 struct btree_iter alloc_iter = { NULL }; 354 struct bkey_s_c alloc_k; 355 struct printbuf buf = PRINTBUF; 356 int ret = 0; 357 358 if (fsck_err_on(!bch2_dev_exists2(c, k.k->p.inode), c, 359 "backpointer for missing device:\n%s", 360 (bch2_bkey_val_to_text(&buf, c, k), buf.buf))) { 361 ret = bch2_btree_delete_at(trans, bp_iter, 0); 362 goto out; 363 } 364 365 alloc_k = bch2_bkey_get_iter(trans, &alloc_iter, BTREE_ID_alloc, 366 bp_pos_to_bucket(c, k.k->p), 0); 367 ret = bkey_err(alloc_k); 368 if (ret) 369 goto out; 370 371 if (fsck_err_on(alloc_k.k->type != KEY_TYPE_alloc_v4, c, 372 "backpointer for nonexistent alloc key: %llu:%llu:0\n%s", 373 alloc_iter.pos.inode, alloc_iter.pos.offset, 374 (bch2_bkey_val_to_text(&buf, c, alloc_k), buf.buf))) { 375 ret = bch2_btree_delete_at(trans, bp_iter, 0); 376 goto out; 377 } 378 out: 379 fsck_err: 380 bch2_trans_iter_exit(trans, &alloc_iter); 381 printbuf_exit(&buf); 382 return ret; 383 } 384 385 /* verify that every backpointer has a corresponding alloc key */ 386 int bch2_check_btree_backpointers(struct bch_fs *c) 387 { 388 struct btree_iter iter; 389 struct bkey_s_c k; 390 int ret; 391 392 ret = bch2_trans_run(c, 393 for_each_btree_key_commit(trans, iter, 394 BTREE_ID_backpointers, POS_MIN, 0, k, 395 NULL, NULL, BTREE_INSERT_LAZY_RW|BTREE_INSERT_NOFAIL, 396 bch2_check_btree_backpointer(trans, &iter, k))); 397 if (ret) 398 bch_err_fn(c, ret); 399 return ret; 400 } 401 402 struct bpos_level { 403 unsigned level; 404 struct bpos pos; 405 }; 406 407 static int check_bp_exists(struct btree_trans *trans, 408 struct bpos bucket, 409 struct bch_backpointer bp, 410 struct bkey_s_c orig_k, 411 struct bpos bucket_start, 412 struct bpos bucket_end, 413 struct bpos_level *last_flushed) 414 { 415 struct bch_fs *c = trans->c; 416 struct btree_iter bp_iter = { NULL }; 417 struct printbuf buf = PRINTBUF; 418 struct bkey_s_c bp_k; 419 int ret; 420 421 if (bpos_lt(bucket, bucket_start) || 422 bpos_gt(bucket, bucket_end)) 423 return 0; 424 425 if (!bch2_dev_bucket_exists(c, bucket)) 426 goto missing; 427 428 bp_k = bch2_bkey_get_iter(trans, &bp_iter, BTREE_ID_backpointers, 429 bucket_pos_to_bp(c, bucket, bp.bucket_offset), 430 0); 431 ret = bkey_err(bp_k); 432 if (ret) 433 goto err; 434 435 if (bp_k.k->type != KEY_TYPE_backpointer || 436 memcmp(bkey_s_c_to_backpointer(bp_k).v, &bp, sizeof(bp))) { 437 if (last_flushed->level != bp.level || 438 !bpos_eq(last_flushed->pos, orig_k.k->p)) { 439 last_flushed->level = bp.level; 440 last_flushed->pos = orig_k.k->p; 441 442 ret = bch2_btree_write_buffer_flush_sync(trans) ?: 443 -BCH_ERR_transaction_restart_write_buffer_flush; 444 goto out; 445 } 446 goto missing; 447 } 448 out: 449 err: 450 fsck_err: 451 bch2_trans_iter_exit(trans, &bp_iter); 452 printbuf_exit(&buf); 453 return ret; 454 missing: 455 prt_printf(&buf, "missing backpointer for btree=%s l=%u ", 456 bch2_btree_ids[bp.btree_id], bp.level); 457 bch2_bkey_val_to_text(&buf, c, orig_k); 458 prt_printf(&buf, "\nbp pos "); 459 bch2_bpos_to_text(&buf, bp_iter.pos); 460 461 if (c->sb.version_upgrade_complete < bcachefs_metadata_version_backpointers || 462 c->opts.reconstruct_alloc || 463 fsck_err(c, "%s", buf.buf)) 464 ret = bch2_bucket_backpointer_mod(trans, bucket, bp, orig_k, true); 465 466 goto out; 467 } 468 469 static int check_extent_to_backpointers(struct btree_trans *trans, 470 struct btree_iter *iter, 471 struct bpos bucket_start, 472 struct bpos bucket_end, 473 struct bpos_level *last_flushed) 474 { 475 struct bch_fs *c = trans->c; 476 struct bkey_ptrs_c ptrs; 477 const union bch_extent_entry *entry; 478 struct extent_ptr_decoded p; 479 struct bkey_s_c k; 480 int ret; 481 482 k = bch2_btree_iter_peek_all_levels(iter); 483 ret = bkey_err(k); 484 if (ret) 485 return ret; 486 if (!k.k) 487 return 0; 488 489 ptrs = bch2_bkey_ptrs_c(k); 490 bkey_for_each_ptr_decode(k.k, ptrs, p, entry) { 491 struct bpos bucket_pos; 492 struct bch_backpointer bp; 493 494 if (p.ptr.cached) 495 continue; 496 497 bch2_extent_ptr_to_bp(c, iter->btree_id, iter->path->level, 498 k, p, &bucket_pos, &bp); 499 500 ret = check_bp_exists(trans, bucket_pos, bp, k, 501 bucket_start, bucket_end, 502 last_flushed); 503 if (ret) 504 return ret; 505 } 506 507 return 0; 508 } 509 510 static int check_btree_root_to_backpointers(struct btree_trans *trans, 511 enum btree_id btree_id, 512 struct bpos bucket_start, 513 struct bpos bucket_end, 514 struct bpos_level *last_flushed) 515 { 516 struct bch_fs *c = trans->c; 517 struct btree_root *r = bch2_btree_id_root(c, btree_id); 518 struct btree_iter iter; 519 struct btree *b; 520 struct bkey_s_c k; 521 struct bkey_ptrs_c ptrs; 522 struct extent_ptr_decoded p; 523 const union bch_extent_entry *entry; 524 int ret; 525 526 bch2_trans_node_iter_init(trans, &iter, btree_id, POS_MIN, 0, r->level, 0); 527 b = bch2_btree_iter_peek_node(&iter); 528 ret = PTR_ERR_OR_ZERO(b); 529 if (ret) 530 goto err; 531 532 BUG_ON(b != btree_node_root(c, b)); 533 534 k = bkey_i_to_s_c(&b->key); 535 ptrs = bch2_bkey_ptrs_c(k); 536 bkey_for_each_ptr_decode(k.k, ptrs, p, entry) { 537 struct bpos bucket_pos; 538 struct bch_backpointer bp; 539 540 if (p.ptr.cached) 541 continue; 542 543 bch2_extent_ptr_to_bp(c, iter.btree_id, b->c.level + 1, 544 k, p, &bucket_pos, &bp); 545 546 ret = check_bp_exists(trans, bucket_pos, bp, k, 547 bucket_start, bucket_end, 548 last_flushed); 549 if (ret) 550 goto err; 551 } 552 err: 553 bch2_trans_iter_exit(trans, &iter); 554 return ret; 555 } 556 557 static inline struct bbpos bp_to_bbpos(struct bch_backpointer bp) 558 { 559 return (struct bbpos) { 560 .btree = bp.btree_id, 561 .pos = bp.pos, 562 }; 563 } 564 565 static size_t btree_nodes_fit_in_ram(struct bch_fs *c) 566 { 567 struct sysinfo i; 568 u64 mem_bytes; 569 570 si_meminfo(&i); 571 mem_bytes = i.totalram * i.mem_unit; 572 return div_u64(mem_bytes >> 1, btree_bytes(c)); 573 } 574 575 static int bch2_get_btree_in_memory_pos(struct btree_trans *trans, 576 unsigned btree_leaf_mask, 577 unsigned btree_interior_mask, 578 struct bbpos start, struct bbpos *end) 579 { 580 struct btree_iter iter; 581 struct bkey_s_c k; 582 size_t btree_nodes = btree_nodes_fit_in_ram(trans->c); 583 enum btree_id btree; 584 int ret = 0; 585 586 for (btree = start.btree; btree < BTREE_ID_NR && !ret; btree++) { 587 unsigned depth = ((1U << btree) & btree_leaf_mask) ? 1 : 2; 588 589 if (!((1U << btree) & btree_leaf_mask) && 590 !((1U << btree) & btree_interior_mask)) 591 continue; 592 593 bch2_trans_node_iter_init(trans, &iter, btree, 594 btree == start.btree ? start.pos : POS_MIN, 595 0, depth, 0); 596 /* 597 * for_each_btree_key_contineu() doesn't check the return value 598 * from bch2_btree_iter_advance(), which is needed when 599 * iterating over interior nodes where we'll see keys at 600 * SPOS_MAX: 601 */ 602 do { 603 k = __bch2_btree_iter_peek_and_restart(trans, &iter, 0); 604 ret = bkey_err(k); 605 if (!k.k || ret) 606 break; 607 608 --btree_nodes; 609 if (!btree_nodes) { 610 *end = BBPOS(btree, k.k->p); 611 bch2_trans_iter_exit(trans, &iter); 612 return 0; 613 } 614 } while (bch2_btree_iter_advance(&iter)); 615 bch2_trans_iter_exit(trans, &iter); 616 } 617 618 *end = BBPOS_MAX; 619 return ret; 620 } 621 622 static int bch2_check_extents_to_backpointers_pass(struct btree_trans *trans, 623 struct bpos bucket_start, 624 struct bpos bucket_end) 625 { 626 struct bch_fs *c = trans->c; 627 struct btree_iter iter; 628 enum btree_id btree_id; 629 struct bpos_level last_flushed = { UINT_MAX, POS_MIN }; 630 int ret = 0; 631 632 for (btree_id = 0; btree_id < btree_id_nr_alive(c); btree_id++) { 633 unsigned depth = btree_type_has_ptrs(btree_id) ? 0 : 1; 634 635 bch2_trans_node_iter_init(trans, &iter, btree_id, POS_MIN, 0, 636 depth, 637 BTREE_ITER_ALL_LEVELS| 638 BTREE_ITER_PREFETCH); 639 640 do { 641 ret = commit_do(trans, NULL, NULL, 642 BTREE_INSERT_LAZY_RW| 643 BTREE_INSERT_NOFAIL, 644 check_extent_to_backpointers(trans, &iter, 645 bucket_start, bucket_end, 646 &last_flushed)); 647 if (ret) 648 break; 649 } while (!bch2_btree_iter_advance(&iter)); 650 651 bch2_trans_iter_exit(trans, &iter); 652 653 if (ret) 654 break; 655 656 ret = commit_do(trans, NULL, NULL, 657 BTREE_INSERT_LAZY_RW| 658 BTREE_INSERT_NOFAIL, 659 check_btree_root_to_backpointers(trans, btree_id, 660 bucket_start, bucket_end, 661 &last_flushed)); 662 if (ret) 663 break; 664 } 665 return ret; 666 } 667 668 static struct bpos bucket_pos_to_bp_safe(const struct bch_fs *c, 669 struct bpos bucket) 670 { 671 return bch2_dev_exists2(c, bucket.inode) 672 ? bucket_pos_to_bp(c, bucket, 0) 673 : bucket; 674 } 675 676 static int bch2_get_alloc_in_memory_pos(struct btree_trans *trans, 677 struct bpos start, struct bpos *end) 678 { 679 struct btree_iter alloc_iter; 680 struct btree_iter bp_iter; 681 struct bkey_s_c alloc_k, bp_k; 682 size_t btree_nodes = btree_nodes_fit_in_ram(trans->c); 683 bool alloc_end = false, bp_end = false; 684 int ret = 0; 685 686 bch2_trans_node_iter_init(trans, &alloc_iter, BTREE_ID_alloc, 687 start, 0, 1, 0); 688 bch2_trans_node_iter_init(trans, &bp_iter, BTREE_ID_backpointers, 689 bucket_pos_to_bp_safe(trans->c, start), 0, 1, 0); 690 while (1) { 691 alloc_k = !alloc_end 692 ? __bch2_btree_iter_peek_and_restart(trans, &alloc_iter, 0) 693 : bkey_s_c_null; 694 bp_k = !bp_end 695 ? __bch2_btree_iter_peek_and_restart(trans, &bp_iter, 0) 696 : bkey_s_c_null; 697 698 ret = bkey_err(alloc_k) ?: bkey_err(bp_k); 699 if ((!alloc_k.k && !bp_k.k) || ret) { 700 *end = SPOS_MAX; 701 break; 702 } 703 704 --btree_nodes; 705 if (!btree_nodes) { 706 *end = alloc_k.k ? alloc_k.k->p : SPOS_MAX; 707 break; 708 } 709 710 if (bpos_lt(alloc_iter.pos, SPOS_MAX) && 711 bpos_lt(bucket_pos_to_bp_safe(trans->c, alloc_iter.pos), bp_iter.pos)) { 712 if (!bch2_btree_iter_advance(&alloc_iter)) 713 alloc_end = true; 714 } else { 715 if (!bch2_btree_iter_advance(&bp_iter)) 716 bp_end = true; 717 } 718 } 719 bch2_trans_iter_exit(trans, &bp_iter); 720 bch2_trans_iter_exit(trans, &alloc_iter); 721 return ret; 722 } 723 724 int bch2_check_extents_to_backpointers(struct bch_fs *c) 725 { 726 struct btree_trans *trans = bch2_trans_get(c); 727 struct bpos start = POS_MIN, end; 728 int ret; 729 730 while (1) { 731 ret = bch2_get_alloc_in_memory_pos(trans, start, &end); 732 if (ret) 733 break; 734 735 if (bpos_eq(start, POS_MIN) && !bpos_eq(end, SPOS_MAX)) 736 bch_verbose(c, "%s(): alloc info does not fit in ram, running in multiple passes with %zu nodes per pass", 737 __func__, btree_nodes_fit_in_ram(c)); 738 739 if (!bpos_eq(start, POS_MIN) || !bpos_eq(end, SPOS_MAX)) { 740 struct printbuf buf = PRINTBUF; 741 742 prt_str(&buf, "check_extents_to_backpointers(): "); 743 bch2_bpos_to_text(&buf, start); 744 prt_str(&buf, "-"); 745 bch2_bpos_to_text(&buf, end); 746 747 bch_verbose(c, "%s", buf.buf); 748 printbuf_exit(&buf); 749 } 750 751 ret = bch2_check_extents_to_backpointers_pass(trans, start, end); 752 if (ret || bpos_eq(end, SPOS_MAX)) 753 break; 754 755 start = bpos_successor(end); 756 } 757 bch2_trans_put(trans); 758 759 if (ret) 760 bch_err_fn(c, ret); 761 return ret; 762 } 763 764 static int check_one_backpointer(struct btree_trans *trans, 765 struct bbpos start, 766 struct bbpos end, 767 struct bkey_s_c_backpointer bp, 768 struct bpos *last_flushed_pos) 769 { 770 struct bch_fs *c = trans->c; 771 struct btree_iter iter; 772 struct bbpos pos = bp_to_bbpos(*bp.v); 773 struct bkey_s_c k; 774 struct printbuf buf = PRINTBUF; 775 int ret; 776 777 if (bbpos_cmp(pos, start) < 0 || 778 bbpos_cmp(pos, end) > 0) 779 return 0; 780 781 k = bch2_backpointer_get_key(trans, &iter, bp.k->p, *bp.v, 0); 782 ret = bkey_err(k); 783 if (ret == -BCH_ERR_backpointer_to_overwritten_btree_node) 784 return 0; 785 if (ret) 786 return ret; 787 788 if (!k.k && !bpos_eq(*last_flushed_pos, bp.k->p)) { 789 *last_flushed_pos = bp.k->p; 790 ret = bch2_btree_write_buffer_flush_sync(trans) ?: 791 -BCH_ERR_transaction_restart_write_buffer_flush; 792 goto out; 793 } 794 795 if (fsck_err_on(!k.k, c, 796 "backpointer for missing extent\n %s", 797 (bch2_bkey_val_to_text(&buf, c, bp.s_c), buf.buf))) { 798 ret = bch2_btree_delete_at_buffered(trans, BTREE_ID_backpointers, bp.k->p); 799 goto out; 800 } 801 out: 802 fsck_err: 803 bch2_trans_iter_exit(trans, &iter); 804 printbuf_exit(&buf); 805 return ret; 806 } 807 808 static int bch2_check_backpointers_to_extents_pass(struct btree_trans *trans, 809 struct bbpos start, 810 struct bbpos end) 811 { 812 struct btree_iter iter; 813 struct bkey_s_c k; 814 struct bpos last_flushed_pos = SPOS_MAX; 815 816 return for_each_btree_key_commit(trans, iter, BTREE_ID_backpointers, 817 POS_MIN, BTREE_ITER_PREFETCH, k, 818 NULL, NULL, BTREE_INSERT_LAZY_RW|BTREE_INSERT_NOFAIL, 819 check_one_backpointer(trans, start, end, 820 bkey_s_c_to_backpointer(k), 821 &last_flushed_pos)); 822 } 823 824 int bch2_check_backpointers_to_extents(struct bch_fs *c) 825 { 826 struct btree_trans *trans = bch2_trans_get(c); 827 struct bbpos start = (struct bbpos) { .btree = 0, .pos = POS_MIN, }, end; 828 int ret; 829 830 while (1) { 831 ret = bch2_get_btree_in_memory_pos(trans, 832 (1U << BTREE_ID_extents)| 833 (1U << BTREE_ID_reflink), 834 ~0, 835 start, &end); 836 if (ret) 837 break; 838 839 if (!bbpos_cmp(start, BBPOS_MIN) && 840 bbpos_cmp(end, BBPOS_MAX)) 841 bch_verbose(c, "%s(): extents do not fit in ram, running in multiple passes with %zu nodes per pass", 842 __func__, btree_nodes_fit_in_ram(c)); 843 844 if (bbpos_cmp(start, BBPOS_MIN) || 845 bbpos_cmp(end, BBPOS_MAX)) { 846 struct printbuf buf = PRINTBUF; 847 848 prt_str(&buf, "check_backpointers_to_extents(): "); 849 bch2_bbpos_to_text(&buf, start); 850 prt_str(&buf, "-"); 851 bch2_bbpos_to_text(&buf, end); 852 853 bch_verbose(c, "%s", buf.buf); 854 printbuf_exit(&buf); 855 } 856 857 ret = bch2_check_backpointers_to_extents_pass(trans, start, end); 858 if (ret || !bbpos_cmp(end, BBPOS_MAX)) 859 break; 860 861 start = bbpos_successor(end); 862 } 863 bch2_trans_put(trans); 864 865 if (ret) 866 bch_err_fn(c, ret); 867 return ret; 868 } 869