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