1 /* 2 * Copyright (C) 2012 Red Hat, Inc. 3 * 4 * This file is released under the GPL. 5 */ 6 7 #include "dm-cache-metadata.h" 8 9 #include "persistent-data/dm-array.h" 10 #include "persistent-data/dm-bitset.h" 11 #include "persistent-data/dm-space-map.h" 12 #include "persistent-data/dm-space-map-disk.h" 13 #include "persistent-data/dm-transaction-manager.h" 14 15 #include <linux/device-mapper.h> 16 #include <linux/refcount.h> 17 18 /*----------------------------------------------------------------*/ 19 20 #define DM_MSG_PREFIX "cache metadata" 21 22 #define CACHE_SUPERBLOCK_MAGIC 06142003 23 #define CACHE_SUPERBLOCK_LOCATION 0 24 25 /* 26 * defines a range of metadata versions that this module can handle. 27 */ 28 #define MIN_CACHE_VERSION 1 29 #define MAX_CACHE_VERSION 2 30 31 /* 32 * 3 for btree insert + 33 * 2 for btree lookup used within space map 34 */ 35 #define CACHE_MAX_CONCURRENT_LOCKS 5 36 #define SPACE_MAP_ROOT_SIZE 128 37 38 enum superblock_flag_bits { 39 /* for spotting crashes that would invalidate the dirty bitset */ 40 CLEAN_SHUTDOWN, 41 /* metadata must be checked using the tools */ 42 NEEDS_CHECK, 43 }; 44 45 /* 46 * Each mapping from cache block -> origin block carries a set of flags. 47 */ 48 enum mapping_bits { 49 /* 50 * A valid mapping. Because we're using an array we clear this 51 * flag for an non existant mapping. 52 */ 53 M_VALID = 1, 54 55 /* 56 * The data on the cache is different from that on the origin. 57 * This flag is only used by metadata format 1. 58 */ 59 M_DIRTY = 2 60 }; 61 62 struct cache_disk_superblock { 63 __le32 csum; 64 __le32 flags; 65 __le64 blocknr; 66 67 __u8 uuid[16]; 68 __le64 magic; 69 __le32 version; 70 71 __u8 policy_name[CACHE_POLICY_NAME_SIZE]; 72 __le32 policy_hint_size; 73 74 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE]; 75 __le64 mapping_root; 76 __le64 hint_root; 77 78 __le64 discard_root; 79 __le64 discard_block_size; 80 __le64 discard_nr_blocks; 81 82 __le32 data_block_size; 83 __le32 metadata_block_size; 84 __le32 cache_blocks; 85 86 __le32 compat_flags; 87 __le32 compat_ro_flags; 88 __le32 incompat_flags; 89 90 __le32 read_hits; 91 __le32 read_misses; 92 __le32 write_hits; 93 __le32 write_misses; 94 95 __le32 policy_version[CACHE_POLICY_VERSION_SIZE]; 96 97 /* 98 * Metadata format 2 fields. 99 */ 100 __le64 dirty_root; 101 } __packed; 102 103 struct dm_cache_metadata { 104 refcount_t ref_count; 105 struct list_head list; 106 107 unsigned version; 108 struct block_device *bdev; 109 struct dm_block_manager *bm; 110 struct dm_space_map *metadata_sm; 111 struct dm_transaction_manager *tm; 112 113 struct dm_array_info info; 114 struct dm_array_info hint_info; 115 struct dm_disk_bitset discard_info; 116 117 struct rw_semaphore root_lock; 118 unsigned long flags; 119 dm_block_t root; 120 dm_block_t hint_root; 121 dm_block_t discard_root; 122 123 sector_t discard_block_size; 124 dm_dblock_t discard_nr_blocks; 125 126 sector_t data_block_size; 127 dm_cblock_t cache_blocks; 128 bool changed:1; 129 bool clean_when_opened:1; 130 131 char policy_name[CACHE_POLICY_NAME_SIZE]; 132 unsigned policy_version[CACHE_POLICY_VERSION_SIZE]; 133 size_t policy_hint_size; 134 struct dm_cache_statistics stats; 135 136 /* 137 * Reading the space map root can fail, so we read it into this 138 * buffer before the superblock is locked and updated. 139 */ 140 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE]; 141 142 /* 143 * Set if a transaction has to be aborted but the attempt to roll 144 * back to the previous (good) transaction failed. The only 145 * metadata operation permissible in this state is the closing of 146 * the device. 147 */ 148 bool fail_io:1; 149 150 /* 151 * Metadata format 2 fields. 152 */ 153 dm_block_t dirty_root; 154 struct dm_disk_bitset dirty_info; 155 156 /* 157 * These structures are used when loading metadata. They're too 158 * big to put on the stack. 159 */ 160 struct dm_array_cursor mapping_cursor; 161 struct dm_array_cursor hint_cursor; 162 struct dm_bitset_cursor dirty_cursor; 163 }; 164 165 /*------------------------------------------------------------------- 166 * superblock validator 167 *-----------------------------------------------------------------*/ 168 169 #define SUPERBLOCK_CSUM_XOR 9031977 170 171 static void sb_prepare_for_write(struct dm_block_validator *v, 172 struct dm_block *b, 173 size_t sb_block_size) 174 { 175 struct cache_disk_superblock *disk_super = dm_block_data(b); 176 177 disk_super->blocknr = cpu_to_le64(dm_block_location(b)); 178 disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags, 179 sb_block_size - sizeof(__le32), 180 SUPERBLOCK_CSUM_XOR)); 181 } 182 183 static int check_metadata_version(struct cache_disk_superblock *disk_super) 184 { 185 uint32_t metadata_version = le32_to_cpu(disk_super->version); 186 187 if (metadata_version < MIN_CACHE_VERSION || metadata_version > MAX_CACHE_VERSION) { 188 DMERR("Cache metadata version %u found, but only versions between %u and %u supported.", 189 metadata_version, MIN_CACHE_VERSION, MAX_CACHE_VERSION); 190 return -EINVAL; 191 } 192 193 return 0; 194 } 195 196 static int sb_check(struct dm_block_validator *v, 197 struct dm_block *b, 198 size_t sb_block_size) 199 { 200 struct cache_disk_superblock *disk_super = dm_block_data(b); 201 __le32 csum_le; 202 203 if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) { 204 DMERR("sb_check failed: blocknr %llu: wanted %llu", 205 le64_to_cpu(disk_super->blocknr), 206 (unsigned long long)dm_block_location(b)); 207 return -ENOTBLK; 208 } 209 210 if (le64_to_cpu(disk_super->magic) != CACHE_SUPERBLOCK_MAGIC) { 211 DMERR("sb_check failed: magic %llu: wanted %llu", 212 le64_to_cpu(disk_super->magic), 213 (unsigned long long)CACHE_SUPERBLOCK_MAGIC); 214 return -EILSEQ; 215 } 216 217 csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags, 218 sb_block_size - sizeof(__le32), 219 SUPERBLOCK_CSUM_XOR)); 220 if (csum_le != disk_super->csum) { 221 DMERR("sb_check failed: csum %u: wanted %u", 222 le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum)); 223 return -EILSEQ; 224 } 225 226 return check_metadata_version(disk_super); 227 } 228 229 static struct dm_block_validator sb_validator = { 230 .name = "superblock", 231 .prepare_for_write = sb_prepare_for_write, 232 .check = sb_check 233 }; 234 235 /*----------------------------------------------------------------*/ 236 237 static int superblock_read_lock(struct dm_cache_metadata *cmd, 238 struct dm_block **sblock) 239 { 240 return dm_bm_read_lock(cmd->bm, CACHE_SUPERBLOCK_LOCATION, 241 &sb_validator, sblock); 242 } 243 244 static int superblock_lock_zero(struct dm_cache_metadata *cmd, 245 struct dm_block **sblock) 246 { 247 return dm_bm_write_lock_zero(cmd->bm, CACHE_SUPERBLOCK_LOCATION, 248 &sb_validator, sblock); 249 } 250 251 static int superblock_lock(struct dm_cache_metadata *cmd, 252 struct dm_block **sblock) 253 { 254 return dm_bm_write_lock(cmd->bm, CACHE_SUPERBLOCK_LOCATION, 255 &sb_validator, sblock); 256 } 257 258 /*----------------------------------------------------------------*/ 259 260 static int __superblock_all_zeroes(struct dm_block_manager *bm, bool *result) 261 { 262 int r; 263 unsigned i; 264 struct dm_block *b; 265 __le64 *data_le, zero = cpu_to_le64(0); 266 unsigned sb_block_size = dm_bm_block_size(bm) / sizeof(__le64); 267 268 /* 269 * We can't use a validator here - it may be all zeroes. 270 */ 271 r = dm_bm_read_lock(bm, CACHE_SUPERBLOCK_LOCATION, NULL, &b); 272 if (r) 273 return r; 274 275 data_le = dm_block_data(b); 276 *result = true; 277 for (i = 0; i < sb_block_size; i++) { 278 if (data_le[i] != zero) { 279 *result = false; 280 break; 281 } 282 } 283 284 dm_bm_unlock(b); 285 286 return 0; 287 } 288 289 static void __setup_mapping_info(struct dm_cache_metadata *cmd) 290 { 291 struct dm_btree_value_type vt; 292 293 vt.context = NULL; 294 vt.size = sizeof(__le64); 295 vt.inc = NULL; 296 vt.dec = NULL; 297 vt.equal = NULL; 298 dm_array_info_init(&cmd->info, cmd->tm, &vt); 299 300 if (cmd->policy_hint_size) { 301 vt.size = sizeof(__le32); 302 dm_array_info_init(&cmd->hint_info, cmd->tm, &vt); 303 } 304 } 305 306 static int __save_sm_root(struct dm_cache_metadata *cmd) 307 { 308 int r; 309 size_t metadata_len; 310 311 r = dm_sm_root_size(cmd->metadata_sm, &metadata_len); 312 if (r < 0) 313 return r; 314 315 return dm_sm_copy_root(cmd->metadata_sm, &cmd->metadata_space_map_root, 316 metadata_len); 317 } 318 319 static void __copy_sm_root(struct dm_cache_metadata *cmd, 320 struct cache_disk_superblock *disk_super) 321 { 322 memcpy(&disk_super->metadata_space_map_root, 323 &cmd->metadata_space_map_root, 324 sizeof(cmd->metadata_space_map_root)); 325 } 326 327 static bool separate_dirty_bits(struct dm_cache_metadata *cmd) 328 { 329 return cmd->version >= 2; 330 } 331 332 static int __write_initial_superblock(struct dm_cache_metadata *cmd) 333 { 334 int r; 335 struct dm_block *sblock; 336 struct cache_disk_superblock *disk_super; 337 sector_t bdev_size = i_size_read(cmd->bdev->bd_inode) >> SECTOR_SHIFT; 338 339 /* FIXME: see if we can lose the max sectors limit */ 340 if (bdev_size > DM_CACHE_METADATA_MAX_SECTORS) 341 bdev_size = DM_CACHE_METADATA_MAX_SECTORS; 342 343 r = dm_tm_pre_commit(cmd->tm); 344 if (r < 0) 345 return r; 346 347 /* 348 * dm_sm_copy_root() can fail. So we need to do it before we start 349 * updating the superblock. 350 */ 351 r = __save_sm_root(cmd); 352 if (r) 353 return r; 354 355 r = superblock_lock_zero(cmd, &sblock); 356 if (r) 357 return r; 358 359 disk_super = dm_block_data(sblock); 360 disk_super->flags = 0; 361 memset(disk_super->uuid, 0, sizeof(disk_super->uuid)); 362 disk_super->magic = cpu_to_le64(CACHE_SUPERBLOCK_MAGIC); 363 disk_super->version = cpu_to_le32(cmd->version); 364 memset(disk_super->policy_name, 0, sizeof(disk_super->policy_name)); 365 memset(disk_super->policy_version, 0, sizeof(disk_super->policy_version)); 366 disk_super->policy_hint_size = cpu_to_le32(0); 367 368 __copy_sm_root(cmd, disk_super); 369 370 disk_super->mapping_root = cpu_to_le64(cmd->root); 371 disk_super->hint_root = cpu_to_le64(cmd->hint_root); 372 disk_super->discard_root = cpu_to_le64(cmd->discard_root); 373 disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size); 374 disk_super->discard_nr_blocks = cpu_to_le64(from_dblock(cmd->discard_nr_blocks)); 375 disk_super->metadata_block_size = cpu_to_le32(DM_CACHE_METADATA_BLOCK_SIZE); 376 disk_super->data_block_size = cpu_to_le32(cmd->data_block_size); 377 disk_super->cache_blocks = cpu_to_le32(0); 378 379 disk_super->read_hits = cpu_to_le32(0); 380 disk_super->read_misses = cpu_to_le32(0); 381 disk_super->write_hits = cpu_to_le32(0); 382 disk_super->write_misses = cpu_to_le32(0); 383 384 if (separate_dirty_bits(cmd)) 385 disk_super->dirty_root = cpu_to_le64(cmd->dirty_root); 386 387 return dm_tm_commit(cmd->tm, sblock); 388 } 389 390 static int __format_metadata(struct dm_cache_metadata *cmd) 391 { 392 int r; 393 394 r = dm_tm_create_with_sm(cmd->bm, CACHE_SUPERBLOCK_LOCATION, 395 &cmd->tm, &cmd->metadata_sm); 396 if (r < 0) { 397 DMERR("tm_create_with_sm failed"); 398 return r; 399 } 400 401 __setup_mapping_info(cmd); 402 403 r = dm_array_empty(&cmd->info, &cmd->root); 404 if (r < 0) 405 goto bad; 406 407 if (separate_dirty_bits(cmd)) { 408 dm_disk_bitset_init(cmd->tm, &cmd->dirty_info); 409 r = dm_bitset_empty(&cmd->dirty_info, &cmd->dirty_root); 410 if (r < 0) 411 goto bad; 412 } 413 414 dm_disk_bitset_init(cmd->tm, &cmd->discard_info); 415 r = dm_bitset_empty(&cmd->discard_info, &cmd->discard_root); 416 if (r < 0) 417 goto bad; 418 419 cmd->discard_block_size = 0; 420 cmd->discard_nr_blocks = 0; 421 422 r = __write_initial_superblock(cmd); 423 if (r) 424 goto bad; 425 426 cmd->clean_when_opened = true; 427 return 0; 428 429 bad: 430 dm_tm_destroy(cmd->tm); 431 dm_sm_destroy(cmd->metadata_sm); 432 433 return r; 434 } 435 436 static int __check_incompat_features(struct cache_disk_superblock *disk_super, 437 struct dm_cache_metadata *cmd) 438 { 439 uint32_t incompat_flags, features; 440 441 incompat_flags = le32_to_cpu(disk_super->incompat_flags); 442 features = incompat_flags & ~DM_CACHE_FEATURE_INCOMPAT_SUPP; 443 if (features) { 444 DMERR("could not access metadata due to unsupported optional features (%lx).", 445 (unsigned long)features); 446 return -EINVAL; 447 } 448 449 /* 450 * Check for read-only metadata to skip the following RDWR checks. 451 */ 452 if (get_disk_ro(cmd->bdev->bd_disk)) 453 return 0; 454 455 features = le32_to_cpu(disk_super->compat_ro_flags) & ~DM_CACHE_FEATURE_COMPAT_RO_SUPP; 456 if (features) { 457 DMERR("could not access metadata RDWR due to unsupported optional features (%lx).", 458 (unsigned long)features); 459 return -EINVAL; 460 } 461 462 return 0; 463 } 464 465 static int __open_metadata(struct dm_cache_metadata *cmd) 466 { 467 int r; 468 struct dm_block *sblock; 469 struct cache_disk_superblock *disk_super; 470 unsigned long sb_flags; 471 472 r = superblock_read_lock(cmd, &sblock); 473 if (r < 0) { 474 DMERR("couldn't read lock superblock"); 475 return r; 476 } 477 478 disk_super = dm_block_data(sblock); 479 480 /* Verify the data block size hasn't changed */ 481 if (le32_to_cpu(disk_super->data_block_size) != cmd->data_block_size) { 482 DMERR("changing the data block size (from %u to %llu) is not supported", 483 le32_to_cpu(disk_super->data_block_size), 484 (unsigned long long)cmd->data_block_size); 485 r = -EINVAL; 486 goto bad; 487 } 488 489 r = __check_incompat_features(disk_super, cmd); 490 if (r < 0) 491 goto bad; 492 493 r = dm_tm_open_with_sm(cmd->bm, CACHE_SUPERBLOCK_LOCATION, 494 disk_super->metadata_space_map_root, 495 sizeof(disk_super->metadata_space_map_root), 496 &cmd->tm, &cmd->metadata_sm); 497 if (r < 0) { 498 DMERR("tm_open_with_sm failed"); 499 goto bad; 500 } 501 502 __setup_mapping_info(cmd); 503 dm_disk_bitset_init(cmd->tm, &cmd->dirty_info); 504 dm_disk_bitset_init(cmd->tm, &cmd->discard_info); 505 sb_flags = le32_to_cpu(disk_super->flags); 506 cmd->clean_when_opened = test_bit(CLEAN_SHUTDOWN, &sb_flags); 507 dm_bm_unlock(sblock); 508 509 return 0; 510 511 bad: 512 dm_bm_unlock(sblock); 513 return r; 514 } 515 516 static int __open_or_format_metadata(struct dm_cache_metadata *cmd, 517 bool format_device) 518 { 519 int r; 520 bool unformatted = false; 521 522 r = __superblock_all_zeroes(cmd->bm, &unformatted); 523 if (r) 524 return r; 525 526 if (unformatted) 527 return format_device ? __format_metadata(cmd) : -EPERM; 528 529 return __open_metadata(cmd); 530 } 531 532 static int __create_persistent_data_objects(struct dm_cache_metadata *cmd, 533 bool may_format_device) 534 { 535 int r; 536 cmd->bm = dm_block_manager_create(cmd->bdev, DM_CACHE_METADATA_BLOCK_SIZE << SECTOR_SHIFT, 537 CACHE_MAX_CONCURRENT_LOCKS); 538 if (IS_ERR(cmd->bm)) { 539 DMERR("could not create block manager"); 540 return PTR_ERR(cmd->bm); 541 } 542 543 r = __open_or_format_metadata(cmd, may_format_device); 544 if (r) 545 dm_block_manager_destroy(cmd->bm); 546 547 return r; 548 } 549 550 static void __destroy_persistent_data_objects(struct dm_cache_metadata *cmd) 551 { 552 dm_sm_destroy(cmd->metadata_sm); 553 dm_tm_destroy(cmd->tm); 554 dm_block_manager_destroy(cmd->bm); 555 } 556 557 typedef unsigned long (*flags_mutator)(unsigned long); 558 559 static void update_flags(struct cache_disk_superblock *disk_super, 560 flags_mutator mutator) 561 { 562 uint32_t sb_flags = mutator(le32_to_cpu(disk_super->flags)); 563 disk_super->flags = cpu_to_le32(sb_flags); 564 } 565 566 static unsigned long set_clean_shutdown(unsigned long flags) 567 { 568 set_bit(CLEAN_SHUTDOWN, &flags); 569 return flags; 570 } 571 572 static unsigned long clear_clean_shutdown(unsigned long flags) 573 { 574 clear_bit(CLEAN_SHUTDOWN, &flags); 575 return flags; 576 } 577 578 static void read_superblock_fields(struct dm_cache_metadata *cmd, 579 struct cache_disk_superblock *disk_super) 580 { 581 cmd->version = le32_to_cpu(disk_super->version); 582 cmd->flags = le32_to_cpu(disk_super->flags); 583 cmd->root = le64_to_cpu(disk_super->mapping_root); 584 cmd->hint_root = le64_to_cpu(disk_super->hint_root); 585 cmd->discard_root = le64_to_cpu(disk_super->discard_root); 586 cmd->discard_block_size = le64_to_cpu(disk_super->discard_block_size); 587 cmd->discard_nr_blocks = to_dblock(le64_to_cpu(disk_super->discard_nr_blocks)); 588 cmd->data_block_size = le32_to_cpu(disk_super->data_block_size); 589 cmd->cache_blocks = to_cblock(le32_to_cpu(disk_super->cache_blocks)); 590 strncpy(cmd->policy_name, disk_super->policy_name, sizeof(cmd->policy_name)); 591 cmd->policy_version[0] = le32_to_cpu(disk_super->policy_version[0]); 592 cmd->policy_version[1] = le32_to_cpu(disk_super->policy_version[1]); 593 cmd->policy_version[2] = le32_to_cpu(disk_super->policy_version[2]); 594 cmd->policy_hint_size = le32_to_cpu(disk_super->policy_hint_size); 595 596 cmd->stats.read_hits = le32_to_cpu(disk_super->read_hits); 597 cmd->stats.read_misses = le32_to_cpu(disk_super->read_misses); 598 cmd->stats.write_hits = le32_to_cpu(disk_super->write_hits); 599 cmd->stats.write_misses = le32_to_cpu(disk_super->write_misses); 600 601 if (separate_dirty_bits(cmd)) 602 cmd->dirty_root = le64_to_cpu(disk_super->dirty_root); 603 604 cmd->changed = false; 605 } 606 607 /* 608 * The mutator updates the superblock flags. 609 */ 610 static int __begin_transaction_flags(struct dm_cache_metadata *cmd, 611 flags_mutator mutator) 612 { 613 int r; 614 struct cache_disk_superblock *disk_super; 615 struct dm_block *sblock; 616 617 r = superblock_lock(cmd, &sblock); 618 if (r) 619 return r; 620 621 disk_super = dm_block_data(sblock); 622 update_flags(disk_super, mutator); 623 read_superblock_fields(cmd, disk_super); 624 dm_bm_unlock(sblock); 625 626 return dm_bm_flush(cmd->bm); 627 } 628 629 static int __begin_transaction(struct dm_cache_metadata *cmd) 630 { 631 int r; 632 struct cache_disk_superblock *disk_super; 633 struct dm_block *sblock; 634 635 /* 636 * We re-read the superblock every time. Shouldn't need to do this 637 * really. 638 */ 639 r = superblock_read_lock(cmd, &sblock); 640 if (r) 641 return r; 642 643 disk_super = dm_block_data(sblock); 644 read_superblock_fields(cmd, disk_super); 645 dm_bm_unlock(sblock); 646 647 return 0; 648 } 649 650 static int __commit_transaction(struct dm_cache_metadata *cmd, 651 flags_mutator mutator) 652 { 653 int r; 654 struct cache_disk_superblock *disk_super; 655 struct dm_block *sblock; 656 657 /* 658 * We need to know if the cache_disk_superblock exceeds a 512-byte sector. 659 */ 660 BUILD_BUG_ON(sizeof(struct cache_disk_superblock) > 512); 661 662 if (separate_dirty_bits(cmd)) { 663 r = dm_bitset_flush(&cmd->dirty_info, cmd->dirty_root, 664 &cmd->dirty_root); 665 if (r) 666 return r; 667 } 668 669 r = dm_bitset_flush(&cmd->discard_info, cmd->discard_root, 670 &cmd->discard_root); 671 if (r) 672 return r; 673 674 r = dm_tm_pre_commit(cmd->tm); 675 if (r < 0) 676 return r; 677 678 r = __save_sm_root(cmd); 679 if (r) 680 return r; 681 682 r = superblock_lock(cmd, &sblock); 683 if (r) 684 return r; 685 686 disk_super = dm_block_data(sblock); 687 688 disk_super->flags = cpu_to_le32(cmd->flags); 689 if (mutator) 690 update_flags(disk_super, mutator); 691 692 disk_super->mapping_root = cpu_to_le64(cmd->root); 693 if (separate_dirty_bits(cmd)) 694 disk_super->dirty_root = cpu_to_le64(cmd->dirty_root); 695 disk_super->hint_root = cpu_to_le64(cmd->hint_root); 696 disk_super->discard_root = cpu_to_le64(cmd->discard_root); 697 disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size); 698 disk_super->discard_nr_blocks = cpu_to_le64(from_dblock(cmd->discard_nr_blocks)); 699 disk_super->cache_blocks = cpu_to_le32(from_cblock(cmd->cache_blocks)); 700 strncpy(disk_super->policy_name, cmd->policy_name, sizeof(disk_super->policy_name)); 701 disk_super->policy_version[0] = cpu_to_le32(cmd->policy_version[0]); 702 disk_super->policy_version[1] = cpu_to_le32(cmd->policy_version[1]); 703 disk_super->policy_version[2] = cpu_to_le32(cmd->policy_version[2]); 704 disk_super->policy_hint_size = cpu_to_le32(cmd->policy_hint_size); 705 706 disk_super->read_hits = cpu_to_le32(cmd->stats.read_hits); 707 disk_super->read_misses = cpu_to_le32(cmd->stats.read_misses); 708 disk_super->write_hits = cpu_to_le32(cmd->stats.write_hits); 709 disk_super->write_misses = cpu_to_le32(cmd->stats.write_misses); 710 __copy_sm_root(cmd, disk_super); 711 712 return dm_tm_commit(cmd->tm, sblock); 713 } 714 715 /*----------------------------------------------------------------*/ 716 717 /* 718 * The mappings are held in a dm-array that has 64-bit values stored in 719 * little-endian format. The index is the cblock, the high 48bits of the 720 * value are the oblock and the low 16 bit the flags. 721 */ 722 #define FLAGS_MASK ((1 << 16) - 1) 723 724 static __le64 pack_value(dm_oblock_t block, unsigned flags) 725 { 726 uint64_t value = from_oblock(block); 727 value <<= 16; 728 value = value | (flags & FLAGS_MASK); 729 return cpu_to_le64(value); 730 } 731 732 static void unpack_value(__le64 value_le, dm_oblock_t *block, unsigned *flags) 733 { 734 uint64_t value = le64_to_cpu(value_le); 735 uint64_t b = value >> 16; 736 *block = to_oblock(b); 737 *flags = value & FLAGS_MASK; 738 } 739 740 /*----------------------------------------------------------------*/ 741 742 static struct dm_cache_metadata *metadata_open(struct block_device *bdev, 743 sector_t data_block_size, 744 bool may_format_device, 745 size_t policy_hint_size, 746 unsigned metadata_version) 747 { 748 int r; 749 struct dm_cache_metadata *cmd; 750 751 cmd = kzalloc(sizeof(*cmd), GFP_KERNEL); 752 if (!cmd) { 753 DMERR("could not allocate metadata struct"); 754 return ERR_PTR(-ENOMEM); 755 } 756 757 cmd->version = metadata_version; 758 refcount_set(&cmd->ref_count, 1); 759 init_rwsem(&cmd->root_lock); 760 cmd->bdev = bdev; 761 cmd->data_block_size = data_block_size; 762 cmd->cache_blocks = 0; 763 cmd->policy_hint_size = policy_hint_size; 764 cmd->changed = true; 765 cmd->fail_io = false; 766 767 r = __create_persistent_data_objects(cmd, may_format_device); 768 if (r) { 769 kfree(cmd); 770 return ERR_PTR(r); 771 } 772 773 r = __begin_transaction_flags(cmd, clear_clean_shutdown); 774 if (r < 0) { 775 dm_cache_metadata_close(cmd); 776 return ERR_PTR(r); 777 } 778 779 return cmd; 780 } 781 782 /* 783 * We keep a little list of ref counted metadata objects to prevent two 784 * different target instances creating separate bufio instances. This is 785 * an issue if a table is reloaded before the suspend. 786 */ 787 static DEFINE_MUTEX(table_lock); 788 static LIST_HEAD(table); 789 790 static struct dm_cache_metadata *lookup(struct block_device *bdev) 791 { 792 struct dm_cache_metadata *cmd; 793 794 list_for_each_entry(cmd, &table, list) 795 if (cmd->bdev == bdev) { 796 refcount_inc(&cmd->ref_count); 797 return cmd; 798 } 799 800 return NULL; 801 } 802 803 static struct dm_cache_metadata *lookup_or_open(struct block_device *bdev, 804 sector_t data_block_size, 805 bool may_format_device, 806 size_t policy_hint_size, 807 unsigned metadata_version) 808 { 809 struct dm_cache_metadata *cmd, *cmd2; 810 811 mutex_lock(&table_lock); 812 cmd = lookup(bdev); 813 mutex_unlock(&table_lock); 814 815 if (cmd) 816 return cmd; 817 818 cmd = metadata_open(bdev, data_block_size, may_format_device, 819 policy_hint_size, metadata_version); 820 if (!IS_ERR(cmd)) { 821 mutex_lock(&table_lock); 822 cmd2 = lookup(bdev); 823 if (cmd2) { 824 mutex_unlock(&table_lock); 825 __destroy_persistent_data_objects(cmd); 826 kfree(cmd); 827 return cmd2; 828 } 829 list_add(&cmd->list, &table); 830 mutex_unlock(&table_lock); 831 } 832 833 return cmd; 834 } 835 836 static bool same_params(struct dm_cache_metadata *cmd, sector_t data_block_size) 837 { 838 if (cmd->data_block_size != data_block_size) { 839 DMERR("data_block_size (%llu) different from that in metadata (%llu)", 840 (unsigned long long) data_block_size, 841 (unsigned long long) cmd->data_block_size); 842 return false; 843 } 844 845 return true; 846 } 847 848 struct dm_cache_metadata *dm_cache_metadata_open(struct block_device *bdev, 849 sector_t data_block_size, 850 bool may_format_device, 851 size_t policy_hint_size, 852 unsigned metadata_version) 853 { 854 struct dm_cache_metadata *cmd = lookup_or_open(bdev, data_block_size, may_format_device, 855 policy_hint_size, metadata_version); 856 857 if (!IS_ERR(cmd) && !same_params(cmd, data_block_size)) { 858 dm_cache_metadata_close(cmd); 859 return ERR_PTR(-EINVAL); 860 } 861 862 return cmd; 863 } 864 865 void dm_cache_metadata_close(struct dm_cache_metadata *cmd) 866 { 867 if (refcount_dec_and_test(&cmd->ref_count)) { 868 mutex_lock(&table_lock); 869 list_del(&cmd->list); 870 mutex_unlock(&table_lock); 871 872 if (!cmd->fail_io) 873 __destroy_persistent_data_objects(cmd); 874 kfree(cmd); 875 } 876 } 877 878 /* 879 * Checks that the given cache block is either unmapped or clean. 880 */ 881 static int block_clean_combined_dirty(struct dm_cache_metadata *cmd, dm_cblock_t b, 882 bool *result) 883 { 884 int r; 885 __le64 value; 886 dm_oblock_t ob; 887 unsigned flags; 888 889 r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(b), &value); 890 if (r) 891 return r; 892 893 unpack_value(value, &ob, &flags); 894 *result = !((flags & M_VALID) && (flags & M_DIRTY)); 895 896 return 0; 897 } 898 899 static int blocks_are_clean_combined_dirty(struct dm_cache_metadata *cmd, 900 dm_cblock_t begin, dm_cblock_t end, 901 bool *result) 902 { 903 int r; 904 *result = true; 905 906 while (begin != end) { 907 r = block_clean_combined_dirty(cmd, begin, result); 908 if (r) { 909 DMERR("block_clean_combined_dirty failed"); 910 return r; 911 } 912 913 if (!*result) { 914 DMERR("cache block %llu is dirty", 915 (unsigned long long) from_cblock(begin)); 916 return 0; 917 } 918 919 begin = to_cblock(from_cblock(begin) + 1); 920 } 921 922 return 0; 923 } 924 925 static int blocks_are_clean_separate_dirty(struct dm_cache_metadata *cmd, 926 dm_cblock_t begin, dm_cblock_t end, 927 bool *result) 928 { 929 int r; 930 bool dirty_flag; 931 *result = true; 932 933 if (from_cblock(cmd->cache_blocks) == 0) 934 /* Nothing to do */ 935 return 0; 936 937 r = dm_bitset_cursor_begin(&cmd->dirty_info, cmd->dirty_root, 938 from_cblock(cmd->cache_blocks), &cmd->dirty_cursor); 939 if (r) { 940 DMERR("%s: dm_bitset_cursor_begin for dirty failed", __func__); 941 return r; 942 } 943 944 r = dm_bitset_cursor_skip(&cmd->dirty_cursor, from_cblock(begin)); 945 if (r) { 946 DMERR("%s: dm_bitset_cursor_skip for dirty failed", __func__); 947 dm_bitset_cursor_end(&cmd->dirty_cursor); 948 return r; 949 } 950 951 while (begin != end) { 952 /* 953 * We assume that unmapped blocks have their dirty bit 954 * cleared. 955 */ 956 dirty_flag = dm_bitset_cursor_get_value(&cmd->dirty_cursor); 957 if (dirty_flag) { 958 DMERR("%s: cache block %llu is dirty", __func__, 959 (unsigned long long) from_cblock(begin)); 960 dm_bitset_cursor_end(&cmd->dirty_cursor); 961 *result = false; 962 return 0; 963 } 964 965 begin = to_cblock(from_cblock(begin) + 1); 966 if (begin == end) 967 break; 968 969 r = dm_bitset_cursor_next(&cmd->dirty_cursor); 970 if (r) { 971 DMERR("%s: dm_bitset_cursor_next for dirty failed", __func__); 972 dm_bitset_cursor_end(&cmd->dirty_cursor); 973 return r; 974 } 975 } 976 977 dm_bitset_cursor_end(&cmd->dirty_cursor); 978 979 return 0; 980 } 981 982 static int blocks_are_unmapped_or_clean(struct dm_cache_metadata *cmd, 983 dm_cblock_t begin, dm_cblock_t end, 984 bool *result) 985 { 986 if (separate_dirty_bits(cmd)) 987 return blocks_are_clean_separate_dirty(cmd, begin, end, result); 988 else 989 return blocks_are_clean_combined_dirty(cmd, begin, end, result); 990 } 991 992 static bool cmd_write_lock(struct dm_cache_metadata *cmd) 993 { 994 down_write(&cmd->root_lock); 995 if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) { 996 up_write(&cmd->root_lock); 997 return false; 998 } 999 return true; 1000 } 1001 1002 #define WRITE_LOCK(cmd) \ 1003 do { \ 1004 if (!cmd_write_lock((cmd))) \ 1005 return -EINVAL; \ 1006 } while(0) 1007 1008 #define WRITE_LOCK_VOID(cmd) \ 1009 do { \ 1010 if (!cmd_write_lock((cmd))) \ 1011 return; \ 1012 } while(0) 1013 1014 #define WRITE_UNLOCK(cmd) \ 1015 up_write(&(cmd)->root_lock) 1016 1017 static bool cmd_read_lock(struct dm_cache_metadata *cmd) 1018 { 1019 down_read(&cmd->root_lock); 1020 if (cmd->fail_io) { 1021 up_read(&cmd->root_lock); 1022 return false; 1023 } 1024 return true; 1025 } 1026 1027 #define READ_LOCK(cmd) \ 1028 do { \ 1029 if (!cmd_read_lock((cmd))) \ 1030 return -EINVAL; \ 1031 } while(0) 1032 1033 #define READ_LOCK_VOID(cmd) \ 1034 do { \ 1035 if (!cmd_read_lock((cmd))) \ 1036 return; \ 1037 } while(0) 1038 1039 #define READ_UNLOCK(cmd) \ 1040 up_read(&(cmd)->root_lock) 1041 1042 int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size) 1043 { 1044 int r; 1045 bool clean; 1046 __le64 null_mapping = pack_value(0, 0); 1047 1048 WRITE_LOCK(cmd); 1049 __dm_bless_for_disk(&null_mapping); 1050 1051 if (from_cblock(new_cache_size) < from_cblock(cmd->cache_blocks)) { 1052 r = blocks_are_unmapped_or_clean(cmd, new_cache_size, cmd->cache_blocks, &clean); 1053 if (r) { 1054 __dm_unbless_for_disk(&null_mapping); 1055 goto out; 1056 } 1057 1058 if (!clean) { 1059 DMERR("unable to shrink cache due to dirty blocks"); 1060 r = -EINVAL; 1061 __dm_unbless_for_disk(&null_mapping); 1062 goto out; 1063 } 1064 } 1065 1066 r = dm_array_resize(&cmd->info, cmd->root, from_cblock(cmd->cache_blocks), 1067 from_cblock(new_cache_size), 1068 &null_mapping, &cmd->root); 1069 if (r) 1070 goto out; 1071 1072 if (separate_dirty_bits(cmd)) { 1073 r = dm_bitset_resize(&cmd->dirty_info, cmd->dirty_root, 1074 from_cblock(cmd->cache_blocks), from_cblock(new_cache_size), 1075 false, &cmd->dirty_root); 1076 if (r) 1077 goto out; 1078 } 1079 1080 cmd->cache_blocks = new_cache_size; 1081 cmd->changed = true; 1082 1083 out: 1084 WRITE_UNLOCK(cmd); 1085 1086 return r; 1087 } 1088 1089 int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd, 1090 sector_t discard_block_size, 1091 dm_dblock_t new_nr_entries) 1092 { 1093 int r; 1094 1095 WRITE_LOCK(cmd); 1096 r = dm_bitset_resize(&cmd->discard_info, 1097 cmd->discard_root, 1098 from_dblock(cmd->discard_nr_blocks), 1099 from_dblock(new_nr_entries), 1100 false, &cmd->discard_root); 1101 if (!r) { 1102 cmd->discard_block_size = discard_block_size; 1103 cmd->discard_nr_blocks = new_nr_entries; 1104 } 1105 1106 cmd->changed = true; 1107 WRITE_UNLOCK(cmd); 1108 1109 return r; 1110 } 1111 1112 static int __set_discard(struct dm_cache_metadata *cmd, dm_dblock_t b) 1113 { 1114 return dm_bitset_set_bit(&cmd->discard_info, cmd->discard_root, 1115 from_dblock(b), &cmd->discard_root); 1116 } 1117 1118 static int __clear_discard(struct dm_cache_metadata *cmd, dm_dblock_t b) 1119 { 1120 return dm_bitset_clear_bit(&cmd->discard_info, cmd->discard_root, 1121 from_dblock(b), &cmd->discard_root); 1122 } 1123 1124 static int __discard(struct dm_cache_metadata *cmd, 1125 dm_dblock_t dblock, bool discard) 1126 { 1127 int r; 1128 1129 r = (discard ? __set_discard : __clear_discard)(cmd, dblock); 1130 if (r) 1131 return r; 1132 1133 cmd->changed = true; 1134 return 0; 1135 } 1136 1137 int dm_cache_set_discard(struct dm_cache_metadata *cmd, 1138 dm_dblock_t dblock, bool discard) 1139 { 1140 int r; 1141 1142 WRITE_LOCK(cmd); 1143 r = __discard(cmd, dblock, discard); 1144 WRITE_UNLOCK(cmd); 1145 1146 return r; 1147 } 1148 1149 static int __load_discards(struct dm_cache_metadata *cmd, 1150 load_discard_fn fn, void *context) 1151 { 1152 int r = 0; 1153 uint32_t b; 1154 struct dm_bitset_cursor c; 1155 1156 if (from_dblock(cmd->discard_nr_blocks) == 0) 1157 /* nothing to do */ 1158 return 0; 1159 1160 if (cmd->clean_when_opened) { 1161 r = dm_bitset_flush(&cmd->discard_info, cmd->discard_root, &cmd->discard_root); 1162 if (r) 1163 return r; 1164 1165 r = dm_bitset_cursor_begin(&cmd->discard_info, cmd->discard_root, 1166 from_dblock(cmd->discard_nr_blocks), &c); 1167 if (r) 1168 return r; 1169 1170 for (b = 0; ; b++) { 1171 r = fn(context, cmd->discard_block_size, to_dblock(b), 1172 dm_bitset_cursor_get_value(&c)); 1173 if (r) 1174 break; 1175 1176 if (b >= (from_dblock(cmd->discard_nr_blocks) - 1)) 1177 break; 1178 1179 r = dm_bitset_cursor_next(&c); 1180 if (r) 1181 break; 1182 } 1183 1184 dm_bitset_cursor_end(&c); 1185 1186 } else { 1187 for (b = 0; b < from_dblock(cmd->discard_nr_blocks); b++) { 1188 r = fn(context, cmd->discard_block_size, to_dblock(b), false); 1189 if (r) 1190 return r; 1191 } 1192 } 1193 1194 return r; 1195 } 1196 1197 int dm_cache_load_discards(struct dm_cache_metadata *cmd, 1198 load_discard_fn fn, void *context) 1199 { 1200 int r; 1201 1202 READ_LOCK(cmd); 1203 r = __load_discards(cmd, fn, context); 1204 READ_UNLOCK(cmd); 1205 1206 return r; 1207 } 1208 1209 int dm_cache_size(struct dm_cache_metadata *cmd, dm_cblock_t *result) 1210 { 1211 READ_LOCK(cmd); 1212 *result = cmd->cache_blocks; 1213 READ_UNLOCK(cmd); 1214 1215 return 0; 1216 } 1217 1218 static int __remove(struct dm_cache_metadata *cmd, dm_cblock_t cblock) 1219 { 1220 int r; 1221 __le64 value = pack_value(0, 0); 1222 1223 __dm_bless_for_disk(&value); 1224 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock), 1225 &value, &cmd->root); 1226 if (r) 1227 return r; 1228 1229 cmd->changed = true; 1230 return 0; 1231 } 1232 1233 int dm_cache_remove_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock) 1234 { 1235 int r; 1236 1237 WRITE_LOCK(cmd); 1238 r = __remove(cmd, cblock); 1239 WRITE_UNLOCK(cmd); 1240 1241 return r; 1242 } 1243 1244 static int __insert(struct dm_cache_metadata *cmd, 1245 dm_cblock_t cblock, dm_oblock_t oblock) 1246 { 1247 int r; 1248 __le64 value = pack_value(oblock, M_VALID); 1249 __dm_bless_for_disk(&value); 1250 1251 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock), 1252 &value, &cmd->root); 1253 if (r) 1254 return r; 1255 1256 cmd->changed = true; 1257 return 0; 1258 } 1259 1260 int dm_cache_insert_mapping(struct dm_cache_metadata *cmd, 1261 dm_cblock_t cblock, dm_oblock_t oblock) 1262 { 1263 int r; 1264 1265 WRITE_LOCK(cmd); 1266 r = __insert(cmd, cblock, oblock); 1267 WRITE_UNLOCK(cmd); 1268 1269 return r; 1270 } 1271 1272 struct thunk { 1273 load_mapping_fn fn; 1274 void *context; 1275 1276 struct dm_cache_metadata *cmd; 1277 bool respect_dirty_flags; 1278 bool hints_valid; 1279 }; 1280 1281 static bool policy_unchanged(struct dm_cache_metadata *cmd, 1282 struct dm_cache_policy *policy) 1283 { 1284 const char *policy_name = dm_cache_policy_get_name(policy); 1285 const unsigned *policy_version = dm_cache_policy_get_version(policy); 1286 size_t policy_hint_size = dm_cache_policy_get_hint_size(policy); 1287 1288 /* 1289 * Ensure policy names match. 1290 */ 1291 if (strncmp(cmd->policy_name, policy_name, sizeof(cmd->policy_name))) 1292 return false; 1293 1294 /* 1295 * Ensure policy major versions match. 1296 */ 1297 if (cmd->policy_version[0] != policy_version[0]) 1298 return false; 1299 1300 /* 1301 * Ensure policy hint sizes match. 1302 */ 1303 if (cmd->policy_hint_size != policy_hint_size) 1304 return false; 1305 1306 return true; 1307 } 1308 1309 static bool hints_array_initialized(struct dm_cache_metadata *cmd) 1310 { 1311 return cmd->hint_root && cmd->policy_hint_size; 1312 } 1313 1314 static bool hints_array_available(struct dm_cache_metadata *cmd, 1315 struct dm_cache_policy *policy) 1316 { 1317 return cmd->clean_when_opened && policy_unchanged(cmd, policy) && 1318 hints_array_initialized(cmd); 1319 } 1320 1321 static int __load_mapping_v1(struct dm_cache_metadata *cmd, 1322 uint64_t cb, bool hints_valid, 1323 struct dm_array_cursor *mapping_cursor, 1324 struct dm_array_cursor *hint_cursor, 1325 load_mapping_fn fn, void *context) 1326 { 1327 int r = 0; 1328 1329 __le64 mapping; 1330 __le32 hint = 0; 1331 1332 __le64 *mapping_value_le; 1333 __le32 *hint_value_le; 1334 1335 dm_oblock_t oblock; 1336 unsigned flags; 1337 bool dirty = true; 1338 1339 dm_array_cursor_get_value(mapping_cursor, (void **) &mapping_value_le); 1340 memcpy(&mapping, mapping_value_le, sizeof(mapping)); 1341 unpack_value(mapping, &oblock, &flags); 1342 1343 if (flags & M_VALID) { 1344 if (hints_valid) { 1345 dm_array_cursor_get_value(hint_cursor, (void **) &hint_value_le); 1346 memcpy(&hint, hint_value_le, sizeof(hint)); 1347 } 1348 if (cmd->clean_when_opened) 1349 dirty = flags & M_DIRTY; 1350 1351 r = fn(context, oblock, to_cblock(cb), dirty, 1352 le32_to_cpu(hint), hints_valid); 1353 if (r) { 1354 DMERR("policy couldn't load cache block %llu", 1355 (unsigned long long) from_cblock(to_cblock(cb))); 1356 } 1357 } 1358 1359 return r; 1360 } 1361 1362 static int __load_mapping_v2(struct dm_cache_metadata *cmd, 1363 uint64_t cb, bool hints_valid, 1364 struct dm_array_cursor *mapping_cursor, 1365 struct dm_array_cursor *hint_cursor, 1366 struct dm_bitset_cursor *dirty_cursor, 1367 load_mapping_fn fn, void *context) 1368 { 1369 int r = 0; 1370 1371 __le64 mapping; 1372 __le32 hint = 0; 1373 1374 __le64 *mapping_value_le; 1375 __le32 *hint_value_le; 1376 1377 dm_oblock_t oblock; 1378 unsigned flags; 1379 bool dirty = true; 1380 1381 dm_array_cursor_get_value(mapping_cursor, (void **) &mapping_value_le); 1382 memcpy(&mapping, mapping_value_le, sizeof(mapping)); 1383 unpack_value(mapping, &oblock, &flags); 1384 1385 if (flags & M_VALID) { 1386 if (hints_valid) { 1387 dm_array_cursor_get_value(hint_cursor, (void **) &hint_value_le); 1388 memcpy(&hint, hint_value_le, sizeof(hint)); 1389 } 1390 if (cmd->clean_when_opened) 1391 dirty = dm_bitset_cursor_get_value(dirty_cursor); 1392 1393 r = fn(context, oblock, to_cblock(cb), dirty, 1394 le32_to_cpu(hint), hints_valid); 1395 if (r) { 1396 DMERR("policy couldn't load cache block %llu", 1397 (unsigned long long) from_cblock(to_cblock(cb))); 1398 } 1399 } 1400 1401 return r; 1402 } 1403 1404 static int __load_mappings(struct dm_cache_metadata *cmd, 1405 struct dm_cache_policy *policy, 1406 load_mapping_fn fn, void *context) 1407 { 1408 int r; 1409 uint64_t cb; 1410 1411 bool hints_valid = hints_array_available(cmd, policy); 1412 1413 if (from_cblock(cmd->cache_blocks) == 0) 1414 /* Nothing to do */ 1415 return 0; 1416 1417 r = dm_array_cursor_begin(&cmd->info, cmd->root, &cmd->mapping_cursor); 1418 if (r) 1419 return r; 1420 1421 if (hints_valid) { 1422 r = dm_array_cursor_begin(&cmd->hint_info, cmd->hint_root, &cmd->hint_cursor); 1423 if (r) { 1424 dm_array_cursor_end(&cmd->mapping_cursor); 1425 return r; 1426 } 1427 } 1428 1429 if (separate_dirty_bits(cmd)) { 1430 r = dm_bitset_cursor_begin(&cmd->dirty_info, cmd->dirty_root, 1431 from_cblock(cmd->cache_blocks), 1432 &cmd->dirty_cursor); 1433 if (r) { 1434 dm_array_cursor_end(&cmd->hint_cursor); 1435 dm_array_cursor_end(&cmd->mapping_cursor); 1436 return r; 1437 } 1438 } 1439 1440 for (cb = 0; ; cb++) { 1441 if (separate_dirty_bits(cmd)) 1442 r = __load_mapping_v2(cmd, cb, hints_valid, 1443 &cmd->mapping_cursor, 1444 &cmd->hint_cursor, 1445 &cmd->dirty_cursor, 1446 fn, context); 1447 else 1448 r = __load_mapping_v1(cmd, cb, hints_valid, 1449 &cmd->mapping_cursor, &cmd->hint_cursor, 1450 fn, context); 1451 if (r) 1452 goto out; 1453 1454 /* 1455 * We need to break out before we move the cursors. 1456 */ 1457 if (cb >= (from_cblock(cmd->cache_blocks) - 1)) 1458 break; 1459 1460 r = dm_array_cursor_next(&cmd->mapping_cursor); 1461 if (r) { 1462 DMERR("dm_array_cursor_next for mapping failed"); 1463 goto out; 1464 } 1465 1466 if (hints_valid) { 1467 r = dm_array_cursor_next(&cmd->hint_cursor); 1468 if (r) { 1469 dm_array_cursor_end(&cmd->hint_cursor); 1470 hints_valid = false; 1471 } 1472 } 1473 1474 if (separate_dirty_bits(cmd)) { 1475 r = dm_bitset_cursor_next(&cmd->dirty_cursor); 1476 if (r) { 1477 DMERR("dm_bitset_cursor_next for dirty failed"); 1478 goto out; 1479 } 1480 } 1481 } 1482 out: 1483 dm_array_cursor_end(&cmd->mapping_cursor); 1484 if (hints_valid) 1485 dm_array_cursor_end(&cmd->hint_cursor); 1486 1487 if (separate_dirty_bits(cmd)) 1488 dm_bitset_cursor_end(&cmd->dirty_cursor); 1489 1490 return r; 1491 } 1492 1493 int dm_cache_load_mappings(struct dm_cache_metadata *cmd, 1494 struct dm_cache_policy *policy, 1495 load_mapping_fn fn, void *context) 1496 { 1497 int r; 1498 1499 READ_LOCK(cmd); 1500 r = __load_mappings(cmd, policy, fn, context); 1501 READ_UNLOCK(cmd); 1502 1503 return r; 1504 } 1505 1506 static int __dump_mapping(void *context, uint64_t cblock, void *leaf) 1507 { 1508 int r = 0; 1509 __le64 value; 1510 dm_oblock_t oblock; 1511 unsigned flags; 1512 1513 memcpy(&value, leaf, sizeof(value)); 1514 unpack_value(value, &oblock, &flags); 1515 1516 return r; 1517 } 1518 1519 static int __dump_mappings(struct dm_cache_metadata *cmd) 1520 { 1521 return dm_array_walk(&cmd->info, cmd->root, __dump_mapping, NULL); 1522 } 1523 1524 void dm_cache_dump(struct dm_cache_metadata *cmd) 1525 { 1526 READ_LOCK_VOID(cmd); 1527 __dump_mappings(cmd); 1528 READ_UNLOCK(cmd); 1529 } 1530 1531 int dm_cache_changed_this_transaction(struct dm_cache_metadata *cmd) 1532 { 1533 int r; 1534 1535 READ_LOCK(cmd); 1536 r = cmd->changed; 1537 READ_UNLOCK(cmd); 1538 1539 return r; 1540 } 1541 1542 static int __dirty(struct dm_cache_metadata *cmd, dm_cblock_t cblock, bool dirty) 1543 { 1544 int r; 1545 unsigned flags; 1546 dm_oblock_t oblock; 1547 __le64 value; 1548 1549 r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(cblock), &value); 1550 if (r) 1551 return r; 1552 1553 unpack_value(value, &oblock, &flags); 1554 1555 if (((flags & M_DIRTY) && dirty) || (!(flags & M_DIRTY) && !dirty)) 1556 /* nothing to be done */ 1557 return 0; 1558 1559 value = pack_value(oblock, (flags & ~M_DIRTY) | (dirty ? M_DIRTY : 0)); 1560 __dm_bless_for_disk(&value); 1561 1562 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock), 1563 &value, &cmd->root); 1564 if (r) 1565 return r; 1566 1567 cmd->changed = true; 1568 return 0; 1569 1570 } 1571 1572 static int __set_dirty_bits_v1(struct dm_cache_metadata *cmd, unsigned nr_bits, unsigned long *bits) 1573 { 1574 int r; 1575 unsigned i; 1576 for (i = 0; i < nr_bits; i++) { 1577 r = __dirty(cmd, to_cblock(i), test_bit(i, bits)); 1578 if (r) 1579 return r; 1580 } 1581 1582 return 0; 1583 } 1584 1585 static int is_dirty_callback(uint32_t index, bool *value, void *context) 1586 { 1587 unsigned long *bits = context; 1588 *value = test_bit(index, bits); 1589 return 0; 1590 } 1591 1592 static int __set_dirty_bits_v2(struct dm_cache_metadata *cmd, unsigned nr_bits, unsigned long *bits) 1593 { 1594 int r = 0; 1595 1596 /* nr_bits is really just a sanity check */ 1597 if (nr_bits != from_cblock(cmd->cache_blocks)) { 1598 DMERR("dirty bitset is wrong size"); 1599 return -EINVAL; 1600 } 1601 1602 r = dm_bitset_del(&cmd->dirty_info, cmd->dirty_root); 1603 if (r) 1604 return r; 1605 1606 cmd->changed = true; 1607 return dm_bitset_new(&cmd->dirty_info, &cmd->dirty_root, nr_bits, is_dirty_callback, bits); 1608 } 1609 1610 int dm_cache_set_dirty_bits(struct dm_cache_metadata *cmd, 1611 unsigned nr_bits, 1612 unsigned long *bits) 1613 { 1614 int r; 1615 1616 WRITE_LOCK(cmd); 1617 if (separate_dirty_bits(cmd)) 1618 r = __set_dirty_bits_v2(cmd, nr_bits, bits); 1619 else 1620 r = __set_dirty_bits_v1(cmd, nr_bits, bits); 1621 WRITE_UNLOCK(cmd); 1622 1623 return r; 1624 } 1625 1626 void dm_cache_metadata_get_stats(struct dm_cache_metadata *cmd, 1627 struct dm_cache_statistics *stats) 1628 { 1629 READ_LOCK_VOID(cmd); 1630 *stats = cmd->stats; 1631 READ_UNLOCK(cmd); 1632 } 1633 1634 void dm_cache_metadata_set_stats(struct dm_cache_metadata *cmd, 1635 struct dm_cache_statistics *stats) 1636 { 1637 WRITE_LOCK_VOID(cmd); 1638 cmd->stats = *stats; 1639 WRITE_UNLOCK(cmd); 1640 } 1641 1642 int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown) 1643 { 1644 int r = -EINVAL; 1645 flags_mutator mutator = (clean_shutdown ? set_clean_shutdown : 1646 clear_clean_shutdown); 1647 1648 WRITE_LOCK(cmd); 1649 if (cmd->fail_io) 1650 goto out; 1651 1652 r = __commit_transaction(cmd, mutator); 1653 if (r) 1654 goto out; 1655 1656 r = __begin_transaction(cmd); 1657 out: 1658 WRITE_UNLOCK(cmd); 1659 return r; 1660 } 1661 1662 int dm_cache_get_free_metadata_block_count(struct dm_cache_metadata *cmd, 1663 dm_block_t *result) 1664 { 1665 int r = -EINVAL; 1666 1667 READ_LOCK(cmd); 1668 if (!cmd->fail_io) 1669 r = dm_sm_get_nr_free(cmd->metadata_sm, result); 1670 READ_UNLOCK(cmd); 1671 1672 return r; 1673 } 1674 1675 int dm_cache_get_metadata_dev_size(struct dm_cache_metadata *cmd, 1676 dm_block_t *result) 1677 { 1678 int r = -EINVAL; 1679 1680 READ_LOCK(cmd); 1681 if (!cmd->fail_io) 1682 r = dm_sm_get_nr_blocks(cmd->metadata_sm, result); 1683 READ_UNLOCK(cmd); 1684 1685 return r; 1686 } 1687 1688 /*----------------------------------------------------------------*/ 1689 1690 static int get_hint(uint32_t index, void *value_le, void *context) 1691 { 1692 uint32_t value; 1693 struct dm_cache_policy *policy = context; 1694 1695 value = policy_get_hint(policy, to_cblock(index)); 1696 *((__le32 *) value_le) = cpu_to_le32(value); 1697 1698 return 0; 1699 } 1700 1701 /* 1702 * It's quicker to always delete the hint array, and recreate with 1703 * dm_array_new(). 1704 */ 1705 static int write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy) 1706 { 1707 int r; 1708 size_t hint_size; 1709 const char *policy_name = dm_cache_policy_get_name(policy); 1710 const unsigned *policy_version = dm_cache_policy_get_version(policy); 1711 1712 if (!policy_name[0] || 1713 (strlen(policy_name) > sizeof(cmd->policy_name) - 1)) 1714 return -EINVAL; 1715 1716 strncpy(cmd->policy_name, policy_name, sizeof(cmd->policy_name)); 1717 memcpy(cmd->policy_version, policy_version, sizeof(cmd->policy_version)); 1718 1719 hint_size = dm_cache_policy_get_hint_size(policy); 1720 if (!hint_size) 1721 return 0; /* short-circuit hints initialization */ 1722 cmd->policy_hint_size = hint_size; 1723 1724 if (cmd->hint_root) { 1725 r = dm_array_del(&cmd->hint_info, cmd->hint_root); 1726 if (r) 1727 return r; 1728 } 1729 1730 return dm_array_new(&cmd->hint_info, &cmd->hint_root, 1731 from_cblock(cmd->cache_blocks), 1732 get_hint, policy); 1733 } 1734 1735 int dm_cache_write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy) 1736 { 1737 int r; 1738 1739 WRITE_LOCK(cmd); 1740 r = write_hints(cmd, policy); 1741 WRITE_UNLOCK(cmd); 1742 1743 return r; 1744 } 1745 1746 int dm_cache_metadata_all_clean(struct dm_cache_metadata *cmd, bool *result) 1747 { 1748 int r; 1749 1750 READ_LOCK(cmd); 1751 r = blocks_are_unmapped_or_clean(cmd, 0, cmd->cache_blocks, result); 1752 READ_UNLOCK(cmd); 1753 1754 return r; 1755 } 1756 1757 void dm_cache_metadata_set_read_only(struct dm_cache_metadata *cmd) 1758 { 1759 WRITE_LOCK_VOID(cmd); 1760 dm_bm_set_read_only(cmd->bm); 1761 WRITE_UNLOCK(cmd); 1762 } 1763 1764 void dm_cache_metadata_set_read_write(struct dm_cache_metadata *cmd) 1765 { 1766 WRITE_LOCK_VOID(cmd); 1767 dm_bm_set_read_write(cmd->bm); 1768 WRITE_UNLOCK(cmd); 1769 } 1770 1771 int dm_cache_metadata_set_needs_check(struct dm_cache_metadata *cmd) 1772 { 1773 int r; 1774 struct dm_block *sblock; 1775 struct cache_disk_superblock *disk_super; 1776 1777 WRITE_LOCK(cmd); 1778 set_bit(NEEDS_CHECK, &cmd->flags); 1779 1780 r = superblock_lock(cmd, &sblock); 1781 if (r) { 1782 DMERR("couldn't read superblock"); 1783 goto out; 1784 } 1785 1786 disk_super = dm_block_data(sblock); 1787 disk_super->flags = cpu_to_le32(cmd->flags); 1788 1789 dm_bm_unlock(sblock); 1790 1791 out: 1792 WRITE_UNLOCK(cmd); 1793 return r; 1794 } 1795 1796 int dm_cache_metadata_needs_check(struct dm_cache_metadata *cmd, bool *result) 1797 { 1798 READ_LOCK(cmd); 1799 *result = !!test_bit(NEEDS_CHECK, &cmd->flags); 1800 READ_UNLOCK(cmd); 1801 1802 return 0; 1803 } 1804 1805 int dm_cache_metadata_abort(struct dm_cache_metadata *cmd) 1806 { 1807 int r; 1808 1809 WRITE_LOCK(cmd); 1810 __destroy_persistent_data_objects(cmd); 1811 r = __create_persistent_data_objects(cmd, false); 1812 if (r) 1813 cmd->fail_io = true; 1814 WRITE_UNLOCK(cmd); 1815 1816 return r; 1817 } 1818