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); 386 387 r = dm_bitset_empty(&cmd->discard_info, &cmd->discard_root); 388 if (r < 0) 389 goto bad; 390 391 cmd->discard_block_size = 0; 392 cmd->discard_nr_blocks = 0; 393 394 r = __write_initial_superblock(cmd); 395 if (r) 396 goto bad; 397 398 cmd->clean_when_opened = true; 399 return 0; 400 401 bad: 402 dm_tm_destroy(cmd->tm); 403 dm_sm_destroy(cmd->metadata_sm); 404 405 return r; 406 } 407 408 static int __check_incompat_features(struct cache_disk_superblock *disk_super, 409 struct dm_cache_metadata *cmd) 410 { 411 uint32_t features; 412 413 features = le32_to_cpu(disk_super->incompat_flags) & ~DM_CACHE_FEATURE_INCOMPAT_SUPP; 414 if (features) { 415 DMERR("could not access metadata due to unsupported optional features (%lx).", 416 (unsigned long)features); 417 return -EINVAL; 418 } 419 420 /* 421 * Check for read-only metadata to skip the following RDWR checks. 422 */ 423 if (get_disk_ro(cmd->bdev->bd_disk)) 424 return 0; 425 426 features = le32_to_cpu(disk_super->compat_ro_flags) & ~DM_CACHE_FEATURE_COMPAT_RO_SUPP; 427 if (features) { 428 DMERR("could not access metadata RDWR due to unsupported optional features (%lx).", 429 (unsigned long)features); 430 return -EINVAL; 431 } 432 433 return 0; 434 } 435 436 static int __open_metadata(struct dm_cache_metadata *cmd) 437 { 438 int r; 439 struct dm_block *sblock; 440 struct cache_disk_superblock *disk_super; 441 unsigned long sb_flags; 442 443 r = superblock_read_lock(cmd, &sblock); 444 if (r < 0) { 445 DMERR("couldn't read lock superblock"); 446 return r; 447 } 448 449 disk_super = dm_block_data(sblock); 450 451 /* Verify the data block size hasn't changed */ 452 if (le32_to_cpu(disk_super->data_block_size) != cmd->data_block_size) { 453 DMERR("changing the data block size (from %u to %llu) is not supported", 454 le32_to_cpu(disk_super->data_block_size), 455 (unsigned long long)cmd->data_block_size); 456 r = -EINVAL; 457 goto bad; 458 } 459 460 r = __check_incompat_features(disk_super, cmd); 461 if (r < 0) 462 goto bad; 463 464 r = dm_tm_open_with_sm(cmd->bm, CACHE_SUPERBLOCK_LOCATION, 465 disk_super->metadata_space_map_root, 466 sizeof(disk_super->metadata_space_map_root), 467 &cmd->tm, &cmd->metadata_sm); 468 if (r < 0) { 469 DMERR("tm_open_with_sm failed"); 470 goto bad; 471 } 472 473 __setup_mapping_info(cmd); 474 dm_disk_bitset_init(cmd->tm, &cmd->discard_info); 475 sb_flags = le32_to_cpu(disk_super->flags); 476 cmd->clean_when_opened = test_bit(CLEAN_SHUTDOWN, &sb_flags); 477 dm_bm_unlock(sblock); 478 479 return 0; 480 481 bad: 482 dm_bm_unlock(sblock); 483 return r; 484 } 485 486 static int __open_or_format_metadata(struct dm_cache_metadata *cmd, 487 bool format_device) 488 { 489 int r; 490 bool unformatted = false; 491 492 r = __superblock_all_zeroes(cmd->bm, &unformatted); 493 if (r) 494 return r; 495 496 if (unformatted) 497 return format_device ? __format_metadata(cmd) : -EPERM; 498 499 return __open_metadata(cmd); 500 } 501 502 static int __create_persistent_data_objects(struct dm_cache_metadata *cmd, 503 bool may_format_device) 504 { 505 int r; 506 cmd->bm = dm_block_manager_create(cmd->bdev, DM_CACHE_METADATA_BLOCK_SIZE << SECTOR_SHIFT, 507 CACHE_METADATA_CACHE_SIZE, 508 CACHE_MAX_CONCURRENT_LOCKS); 509 if (IS_ERR(cmd->bm)) { 510 DMERR("could not create block manager"); 511 return PTR_ERR(cmd->bm); 512 } 513 514 r = __open_or_format_metadata(cmd, may_format_device); 515 if (r) 516 dm_block_manager_destroy(cmd->bm); 517 518 return r; 519 } 520 521 static void __destroy_persistent_data_objects(struct dm_cache_metadata *cmd) 522 { 523 dm_sm_destroy(cmd->metadata_sm); 524 dm_tm_destroy(cmd->tm); 525 dm_block_manager_destroy(cmd->bm); 526 } 527 528 typedef unsigned long (*flags_mutator)(unsigned long); 529 530 static void update_flags(struct cache_disk_superblock *disk_super, 531 flags_mutator mutator) 532 { 533 uint32_t sb_flags = mutator(le32_to_cpu(disk_super->flags)); 534 disk_super->flags = cpu_to_le32(sb_flags); 535 } 536 537 static unsigned long set_clean_shutdown(unsigned long flags) 538 { 539 set_bit(CLEAN_SHUTDOWN, &flags); 540 return flags; 541 } 542 543 static unsigned long clear_clean_shutdown(unsigned long flags) 544 { 545 clear_bit(CLEAN_SHUTDOWN, &flags); 546 return flags; 547 } 548 549 static void read_superblock_fields(struct dm_cache_metadata *cmd, 550 struct cache_disk_superblock *disk_super) 551 { 552 cmd->flags = le32_to_cpu(disk_super->flags); 553 cmd->root = le64_to_cpu(disk_super->mapping_root); 554 cmd->hint_root = le64_to_cpu(disk_super->hint_root); 555 cmd->discard_root = le64_to_cpu(disk_super->discard_root); 556 cmd->discard_block_size = le64_to_cpu(disk_super->discard_block_size); 557 cmd->discard_nr_blocks = to_dblock(le64_to_cpu(disk_super->discard_nr_blocks)); 558 cmd->data_block_size = le32_to_cpu(disk_super->data_block_size); 559 cmd->cache_blocks = to_cblock(le32_to_cpu(disk_super->cache_blocks)); 560 strncpy(cmd->policy_name, disk_super->policy_name, sizeof(cmd->policy_name)); 561 cmd->policy_version[0] = le32_to_cpu(disk_super->policy_version[0]); 562 cmd->policy_version[1] = le32_to_cpu(disk_super->policy_version[1]); 563 cmd->policy_version[2] = le32_to_cpu(disk_super->policy_version[2]); 564 cmd->policy_hint_size = le32_to_cpu(disk_super->policy_hint_size); 565 566 cmd->stats.read_hits = le32_to_cpu(disk_super->read_hits); 567 cmd->stats.read_misses = le32_to_cpu(disk_super->read_misses); 568 cmd->stats.write_hits = le32_to_cpu(disk_super->write_hits); 569 cmd->stats.write_misses = le32_to_cpu(disk_super->write_misses); 570 571 cmd->changed = false; 572 } 573 574 /* 575 * The mutator updates the superblock flags. 576 */ 577 static int __begin_transaction_flags(struct dm_cache_metadata *cmd, 578 flags_mutator mutator) 579 { 580 int r; 581 struct cache_disk_superblock *disk_super; 582 struct dm_block *sblock; 583 584 r = superblock_lock(cmd, &sblock); 585 if (r) 586 return r; 587 588 disk_super = dm_block_data(sblock); 589 update_flags(disk_super, mutator); 590 read_superblock_fields(cmd, disk_super); 591 dm_bm_unlock(sblock); 592 593 return dm_bm_flush(cmd->bm); 594 } 595 596 static int __begin_transaction(struct dm_cache_metadata *cmd) 597 { 598 int r; 599 struct cache_disk_superblock *disk_super; 600 struct dm_block *sblock; 601 602 /* 603 * We re-read the superblock every time. Shouldn't need to do this 604 * really. 605 */ 606 r = superblock_read_lock(cmd, &sblock); 607 if (r) 608 return r; 609 610 disk_super = dm_block_data(sblock); 611 read_superblock_fields(cmd, disk_super); 612 dm_bm_unlock(sblock); 613 614 return 0; 615 } 616 617 static int __commit_transaction(struct dm_cache_metadata *cmd, 618 flags_mutator mutator) 619 { 620 int r; 621 struct cache_disk_superblock *disk_super; 622 struct dm_block *sblock; 623 624 /* 625 * We need to know if the cache_disk_superblock exceeds a 512-byte sector. 626 */ 627 BUILD_BUG_ON(sizeof(struct cache_disk_superblock) > 512); 628 629 r = dm_bitset_flush(&cmd->discard_info, cmd->discard_root, 630 &cmd->discard_root); 631 if (r) 632 return r; 633 634 r = dm_tm_pre_commit(cmd->tm); 635 if (r < 0) 636 return r; 637 638 r = __save_sm_root(cmd); 639 if (r) 640 return r; 641 642 r = superblock_lock(cmd, &sblock); 643 if (r) 644 return r; 645 646 disk_super = dm_block_data(sblock); 647 648 disk_super->flags = cpu_to_le32(cmd->flags); 649 if (mutator) 650 update_flags(disk_super, mutator); 651 652 disk_super->mapping_root = cpu_to_le64(cmd->root); 653 disk_super->hint_root = cpu_to_le64(cmd->hint_root); 654 disk_super->discard_root = cpu_to_le64(cmd->discard_root); 655 disk_super->discard_block_size = cpu_to_le64(cmd->discard_block_size); 656 disk_super->discard_nr_blocks = cpu_to_le64(from_dblock(cmd->discard_nr_blocks)); 657 disk_super->cache_blocks = cpu_to_le32(from_cblock(cmd->cache_blocks)); 658 strncpy(disk_super->policy_name, cmd->policy_name, sizeof(disk_super->policy_name)); 659 disk_super->policy_version[0] = cpu_to_le32(cmd->policy_version[0]); 660 disk_super->policy_version[1] = cpu_to_le32(cmd->policy_version[1]); 661 disk_super->policy_version[2] = cpu_to_le32(cmd->policy_version[2]); 662 663 disk_super->read_hits = cpu_to_le32(cmd->stats.read_hits); 664 disk_super->read_misses = cpu_to_le32(cmd->stats.read_misses); 665 disk_super->write_hits = cpu_to_le32(cmd->stats.write_hits); 666 disk_super->write_misses = cpu_to_le32(cmd->stats.write_misses); 667 __copy_sm_root(cmd, disk_super); 668 669 return dm_tm_commit(cmd->tm, sblock); 670 } 671 672 /*----------------------------------------------------------------*/ 673 674 /* 675 * The mappings are held in a dm-array that has 64-bit values stored in 676 * little-endian format. The index is the cblock, the high 48bits of the 677 * value are the oblock and the low 16 bit the flags. 678 */ 679 #define FLAGS_MASK ((1 << 16) - 1) 680 681 static __le64 pack_value(dm_oblock_t block, unsigned flags) 682 { 683 uint64_t value = from_oblock(block); 684 value <<= 16; 685 value = value | (flags & FLAGS_MASK); 686 return cpu_to_le64(value); 687 } 688 689 static void unpack_value(__le64 value_le, dm_oblock_t *block, unsigned *flags) 690 { 691 uint64_t value = le64_to_cpu(value_le); 692 uint64_t b = value >> 16; 693 *block = to_oblock(b); 694 *flags = value & FLAGS_MASK; 695 } 696 697 /*----------------------------------------------------------------*/ 698 699 static struct dm_cache_metadata *metadata_open(struct block_device *bdev, 700 sector_t data_block_size, 701 bool may_format_device, 702 size_t policy_hint_size) 703 { 704 int r; 705 struct dm_cache_metadata *cmd; 706 707 cmd = kzalloc(sizeof(*cmd), GFP_KERNEL); 708 if (!cmd) { 709 DMERR("could not allocate metadata struct"); 710 return ERR_PTR(-ENOMEM); 711 } 712 713 atomic_set(&cmd->ref_count, 1); 714 init_rwsem(&cmd->root_lock); 715 cmd->bdev = bdev; 716 cmd->data_block_size = data_block_size; 717 cmd->cache_blocks = 0; 718 cmd->policy_hint_size = policy_hint_size; 719 cmd->changed = true; 720 cmd->fail_io = false; 721 722 r = __create_persistent_data_objects(cmd, may_format_device); 723 if (r) { 724 kfree(cmd); 725 return ERR_PTR(r); 726 } 727 728 r = __begin_transaction_flags(cmd, clear_clean_shutdown); 729 if (r < 0) { 730 dm_cache_metadata_close(cmd); 731 return ERR_PTR(r); 732 } 733 734 return cmd; 735 } 736 737 /* 738 * We keep a little list of ref counted metadata objects to prevent two 739 * different target instances creating separate bufio instances. This is 740 * an issue if a table is reloaded before the suspend. 741 */ 742 static DEFINE_MUTEX(table_lock); 743 static LIST_HEAD(table); 744 745 static struct dm_cache_metadata *lookup(struct block_device *bdev) 746 { 747 struct dm_cache_metadata *cmd; 748 749 list_for_each_entry(cmd, &table, list) 750 if (cmd->bdev == bdev) { 751 atomic_inc(&cmd->ref_count); 752 return cmd; 753 } 754 755 return NULL; 756 } 757 758 static struct dm_cache_metadata *lookup_or_open(struct block_device *bdev, 759 sector_t data_block_size, 760 bool may_format_device, 761 size_t policy_hint_size) 762 { 763 struct dm_cache_metadata *cmd, *cmd2; 764 765 mutex_lock(&table_lock); 766 cmd = lookup(bdev); 767 mutex_unlock(&table_lock); 768 769 if (cmd) 770 return cmd; 771 772 cmd = metadata_open(bdev, data_block_size, may_format_device, policy_hint_size); 773 if (!IS_ERR(cmd)) { 774 mutex_lock(&table_lock); 775 cmd2 = lookup(bdev); 776 if (cmd2) { 777 mutex_unlock(&table_lock); 778 __destroy_persistent_data_objects(cmd); 779 kfree(cmd); 780 return cmd2; 781 } 782 list_add(&cmd->list, &table); 783 mutex_unlock(&table_lock); 784 } 785 786 return cmd; 787 } 788 789 static bool same_params(struct dm_cache_metadata *cmd, sector_t data_block_size) 790 { 791 if (cmd->data_block_size != data_block_size) { 792 DMERR("data_block_size (%llu) different from that in metadata (%llu)\n", 793 (unsigned long long) data_block_size, 794 (unsigned long long) cmd->data_block_size); 795 return false; 796 } 797 798 return true; 799 } 800 801 struct dm_cache_metadata *dm_cache_metadata_open(struct block_device *bdev, 802 sector_t data_block_size, 803 bool may_format_device, 804 size_t policy_hint_size) 805 { 806 struct dm_cache_metadata *cmd = lookup_or_open(bdev, data_block_size, 807 may_format_device, policy_hint_size); 808 809 if (!IS_ERR(cmd) && !same_params(cmd, data_block_size)) { 810 dm_cache_metadata_close(cmd); 811 return ERR_PTR(-EINVAL); 812 } 813 814 return cmd; 815 } 816 817 void dm_cache_metadata_close(struct dm_cache_metadata *cmd) 818 { 819 if (atomic_dec_and_test(&cmd->ref_count)) { 820 mutex_lock(&table_lock); 821 list_del(&cmd->list); 822 mutex_unlock(&table_lock); 823 824 if (!cmd->fail_io) 825 __destroy_persistent_data_objects(cmd); 826 kfree(cmd); 827 } 828 } 829 830 /* 831 * Checks that the given cache block is either unmapped or clean. 832 */ 833 static int block_unmapped_or_clean(struct dm_cache_metadata *cmd, dm_cblock_t b, 834 bool *result) 835 { 836 int r; 837 __le64 value; 838 dm_oblock_t ob; 839 unsigned flags; 840 841 r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(b), &value); 842 if (r) { 843 DMERR("block_unmapped_or_clean failed"); 844 return r; 845 } 846 847 unpack_value(value, &ob, &flags); 848 *result = !((flags & M_VALID) && (flags & M_DIRTY)); 849 850 return 0; 851 } 852 853 static int blocks_are_unmapped_or_clean(struct dm_cache_metadata *cmd, 854 dm_cblock_t begin, dm_cblock_t end, 855 bool *result) 856 { 857 int r; 858 *result = true; 859 860 while (begin != end) { 861 r = block_unmapped_or_clean(cmd, begin, result); 862 if (r) 863 return r; 864 865 if (!*result) { 866 DMERR("cache block %llu is dirty", 867 (unsigned long long) from_cblock(begin)); 868 return 0; 869 } 870 871 begin = to_cblock(from_cblock(begin) + 1); 872 } 873 874 return 0; 875 } 876 877 static bool cmd_write_lock(struct dm_cache_metadata *cmd) 878 { 879 down_write(&cmd->root_lock); 880 if (cmd->fail_io || dm_bm_is_read_only(cmd->bm)) { 881 up_write(&cmd->root_lock); 882 return false; 883 } 884 return true; 885 } 886 887 #define WRITE_LOCK(cmd) \ 888 do { \ 889 if (!cmd_write_lock((cmd))) \ 890 return -EINVAL; \ 891 } while(0) 892 893 #define WRITE_LOCK_VOID(cmd) \ 894 do { \ 895 if (!cmd_write_lock((cmd))) \ 896 return; \ 897 } while(0) 898 899 #define WRITE_UNLOCK(cmd) \ 900 up_write(&(cmd)->root_lock) 901 902 static bool cmd_read_lock(struct dm_cache_metadata *cmd) 903 { 904 down_read(&cmd->root_lock); 905 if (cmd->fail_io) { 906 up_read(&cmd->root_lock); 907 return false; 908 } 909 return true; 910 } 911 912 #define READ_LOCK(cmd) \ 913 do { \ 914 if (!cmd_read_lock((cmd))) \ 915 return -EINVAL; \ 916 } while(0) 917 918 #define READ_LOCK_VOID(cmd) \ 919 do { \ 920 if (!cmd_read_lock((cmd))) \ 921 return; \ 922 } while(0) 923 924 #define READ_UNLOCK(cmd) \ 925 up_read(&(cmd)->root_lock) 926 927 int dm_cache_resize(struct dm_cache_metadata *cmd, dm_cblock_t new_cache_size) 928 { 929 int r; 930 bool clean; 931 __le64 null_mapping = pack_value(0, 0); 932 933 WRITE_LOCK(cmd); 934 __dm_bless_for_disk(&null_mapping); 935 936 if (from_cblock(new_cache_size) < from_cblock(cmd->cache_blocks)) { 937 r = blocks_are_unmapped_or_clean(cmd, new_cache_size, cmd->cache_blocks, &clean); 938 if (r) { 939 __dm_unbless_for_disk(&null_mapping); 940 goto out; 941 } 942 943 if (!clean) { 944 DMERR("unable to shrink cache due to dirty blocks"); 945 r = -EINVAL; 946 __dm_unbless_for_disk(&null_mapping); 947 goto out; 948 } 949 } 950 951 r = dm_array_resize(&cmd->info, cmd->root, from_cblock(cmd->cache_blocks), 952 from_cblock(new_cache_size), 953 &null_mapping, &cmd->root); 954 if (!r) 955 cmd->cache_blocks = new_cache_size; 956 cmd->changed = true; 957 958 out: 959 WRITE_UNLOCK(cmd); 960 961 return r; 962 } 963 964 int dm_cache_discard_bitset_resize(struct dm_cache_metadata *cmd, 965 sector_t discard_block_size, 966 dm_dblock_t new_nr_entries) 967 { 968 int r; 969 970 WRITE_LOCK(cmd); 971 r = dm_bitset_resize(&cmd->discard_info, 972 cmd->discard_root, 973 from_dblock(cmd->discard_nr_blocks), 974 from_dblock(new_nr_entries), 975 false, &cmd->discard_root); 976 if (!r) { 977 cmd->discard_block_size = discard_block_size; 978 cmd->discard_nr_blocks = new_nr_entries; 979 } 980 981 cmd->changed = true; 982 WRITE_UNLOCK(cmd); 983 984 return r; 985 } 986 987 static int __set_discard(struct dm_cache_metadata *cmd, dm_dblock_t b) 988 { 989 return dm_bitset_set_bit(&cmd->discard_info, cmd->discard_root, 990 from_dblock(b), &cmd->discard_root); 991 } 992 993 static int __clear_discard(struct dm_cache_metadata *cmd, dm_dblock_t b) 994 { 995 return dm_bitset_clear_bit(&cmd->discard_info, cmd->discard_root, 996 from_dblock(b), &cmd->discard_root); 997 } 998 999 static int __is_discarded(struct dm_cache_metadata *cmd, dm_dblock_t b, 1000 bool *is_discarded) 1001 { 1002 return dm_bitset_test_bit(&cmd->discard_info, cmd->discard_root, 1003 from_dblock(b), &cmd->discard_root, 1004 is_discarded); 1005 } 1006 1007 static int __discard(struct dm_cache_metadata *cmd, 1008 dm_dblock_t dblock, bool discard) 1009 { 1010 int r; 1011 1012 r = (discard ? __set_discard : __clear_discard)(cmd, dblock); 1013 if (r) 1014 return r; 1015 1016 cmd->changed = true; 1017 return 0; 1018 } 1019 1020 int dm_cache_set_discard(struct dm_cache_metadata *cmd, 1021 dm_dblock_t dblock, bool discard) 1022 { 1023 int r; 1024 1025 WRITE_LOCK(cmd); 1026 r = __discard(cmd, dblock, discard); 1027 WRITE_UNLOCK(cmd); 1028 1029 return r; 1030 } 1031 1032 static int __load_discards(struct dm_cache_metadata *cmd, 1033 load_discard_fn fn, void *context) 1034 { 1035 int r = 0; 1036 dm_block_t b; 1037 bool discard; 1038 1039 for (b = 0; b < from_dblock(cmd->discard_nr_blocks); b++) { 1040 dm_dblock_t dblock = to_dblock(b); 1041 1042 if (cmd->clean_when_opened) { 1043 r = __is_discarded(cmd, dblock, &discard); 1044 if (r) 1045 return r; 1046 } else 1047 discard = false; 1048 1049 r = fn(context, cmd->discard_block_size, dblock, discard); 1050 if (r) 1051 break; 1052 } 1053 1054 return r; 1055 } 1056 1057 int dm_cache_load_discards(struct dm_cache_metadata *cmd, 1058 load_discard_fn fn, void *context) 1059 { 1060 int r; 1061 1062 READ_LOCK(cmd); 1063 r = __load_discards(cmd, fn, context); 1064 READ_UNLOCK(cmd); 1065 1066 return r; 1067 } 1068 1069 int dm_cache_size(struct dm_cache_metadata *cmd, dm_cblock_t *result) 1070 { 1071 READ_LOCK(cmd); 1072 *result = cmd->cache_blocks; 1073 READ_UNLOCK(cmd); 1074 1075 return 0; 1076 } 1077 1078 static int __remove(struct dm_cache_metadata *cmd, dm_cblock_t cblock) 1079 { 1080 int r; 1081 __le64 value = pack_value(0, 0); 1082 1083 __dm_bless_for_disk(&value); 1084 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock), 1085 &value, &cmd->root); 1086 if (r) 1087 return r; 1088 1089 cmd->changed = true; 1090 return 0; 1091 } 1092 1093 int dm_cache_remove_mapping(struct dm_cache_metadata *cmd, dm_cblock_t cblock) 1094 { 1095 int r; 1096 1097 WRITE_LOCK(cmd); 1098 r = __remove(cmd, cblock); 1099 WRITE_UNLOCK(cmd); 1100 1101 return r; 1102 } 1103 1104 static int __insert(struct dm_cache_metadata *cmd, 1105 dm_cblock_t cblock, dm_oblock_t oblock) 1106 { 1107 int r; 1108 __le64 value = pack_value(oblock, M_VALID); 1109 __dm_bless_for_disk(&value); 1110 1111 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock), 1112 &value, &cmd->root); 1113 if (r) 1114 return r; 1115 1116 cmd->changed = true; 1117 return 0; 1118 } 1119 1120 int dm_cache_insert_mapping(struct dm_cache_metadata *cmd, 1121 dm_cblock_t cblock, dm_oblock_t oblock) 1122 { 1123 int r; 1124 1125 WRITE_LOCK(cmd); 1126 r = __insert(cmd, cblock, oblock); 1127 WRITE_UNLOCK(cmd); 1128 1129 return r; 1130 } 1131 1132 struct thunk { 1133 load_mapping_fn fn; 1134 void *context; 1135 1136 struct dm_cache_metadata *cmd; 1137 bool respect_dirty_flags; 1138 bool hints_valid; 1139 }; 1140 1141 static bool policy_unchanged(struct dm_cache_metadata *cmd, 1142 struct dm_cache_policy *policy) 1143 { 1144 const char *policy_name = dm_cache_policy_get_name(policy); 1145 const unsigned *policy_version = dm_cache_policy_get_version(policy); 1146 size_t policy_hint_size = dm_cache_policy_get_hint_size(policy); 1147 1148 /* 1149 * Ensure policy names match. 1150 */ 1151 if (strncmp(cmd->policy_name, policy_name, sizeof(cmd->policy_name))) 1152 return false; 1153 1154 /* 1155 * Ensure policy major versions match. 1156 */ 1157 if (cmd->policy_version[0] != policy_version[0]) 1158 return false; 1159 1160 /* 1161 * Ensure policy hint sizes match. 1162 */ 1163 if (cmd->policy_hint_size != policy_hint_size) 1164 return false; 1165 1166 return true; 1167 } 1168 1169 static bool hints_array_initialized(struct dm_cache_metadata *cmd) 1170 { 1171 return cmd->hint_root && cmd->policy_hint_size; 1172 } 1173 1174 static bool hints_array_available(struct dm_cache_metadata *cmd, 1175 struct dm_cache_policy *policy) 1176 { 1177 return cmd->clean_when_opened && policy_unchanged(cmd, policy) && 1178 hints_array_initialized(cmd); 1179 } 1180 1181 static int __load_mapping(struct dm_cache_metadata *cmd, 1182 uint64_t cb, bool hints_valid, 1183 struct dm_array_cursor *mapping_cursor, 1184 struct dm_array_cursor *hint_cursor, 1185 load_mapping_fn fn, void *context) 1186 { 1187 int r = 0; 1188 1189 __le64 mapping; 1190 __le32 hint = 0; 1191 1192 __le64 *mapping_value_le; 1193 __le32 *hint_value_le; 1194 1195 dm_oblock_t oblock; 1196 unsigned flags; 1197 1198 dm_array_cursor_get_value(mapping_cursor, (void **) &mapping_value_le); 1199 memcpy(&mapping, mapping_value_le, sizeof(mapping)); 1200 unpack_value(mapping, &oblock, &flags); 1201 1202 if (flags & M_VALID) { 1203 if (hints_valid) { 1204 dm_array_cursor_get_value(hint_cursor, (void **) &hint_value_le); 1205 memcpy(&hint, hint_value_le, sizeof(hint)); 1206 } 1207 1208 r = fn(context, oblock, to_cblock(cb), flags & M_DIRTY, 1209 le32_to_cpu(hint), hints_valid); 1210 if (r) 1211 DMERR("policy couldn't load cblock"); 1212 } 1213 1214 return r; 1215 } 1216 1217 static int __load_mappings(struct dm_cache_metadata *cmd, 1218 struct dm_cache_policy *policy, 1219 load_mapping_fn fn, void *context) 1220 { 1221 int r; 1222 uint64_t cb; 1223 1224 bool hints_valid = hints_array_available(cmd, policy); 1225 1226 if (from_cblock(cmd->cache_blocks) == 0) 1227 /* Nothing to do */ 1228 return 0; 1229 1230 r = dm_array_cursor_begin(&cmd->info, cmd->root, &cmd->mapping_cursor); 1231 if (r) 1232 return r; 1233 1234 if (hints_valid) { 1235 r = dm_array_cursor_begin(&cmd->hint_info, cmd->hint_root, &cmd->hint_cursor); 1236 if (r) { 1237 dm_array_cursor_end(&cmd->mapping_cursor); 1238 return r; 1239 } 1240 } 1241 1242 for (cb = 0; ; cb++) { 1243 r = __load_mapping(cmd, cb, hints_valid, 1244 &cmd->mapping_cursor, &cmd->hint_cursor, 1245 fn, context); 1246 if (r) 1247 goto out; 1248 1249 /* 1250 * We need to break out before we move the cursors. 1251 */ 1252 if (cb >= (from_cblock(cmd->cache_blocks) - 1)) 1253 break; 1254 1255 r = dm_array_cursor_next(&cmd->mapping_cursor); 1256 if (r) { 1257 DMERR("dm_array_cursor_next for mapping failed"); 1258 goto out; 1259 } 1260 1261 if (hints_valid) { 1262 r = dm_array_cursor_next(&cmd->hint_cursor); 1263 if (r) { 1264 DMERR("dm_array_cursor_next for hint failed"); 1265 goto out; 1266 } 1267 } 1268 } 1269 out: 1270 dm_array_cursor_end(&cmd->mapping_cursor); 1271 if (hints_valid) 1272 dm_array_cursor_end(&cmd->hint_cursor); 1273 1274 return r; 1275 } 1276 1277 int dm_cache_load_mappings(struct dm_cache_metadata *cmd, 1278 struct dm_cache_policy *policy, 1279 load_mapping_fn fn, void *context) 1280 { 1281 int r; 1282 1283 READ_LOCK(cmd); 1284 r = __load_mappings(cmd, policy, fn, context); 1285 READ_UNLOCK(cmd); 1286 1287 return r; 1288 } 1289 1290 static int __dump_mapping(void *context, uint64_t cblock, void *leaf) 1291 { 1292 int r = 0; 1293 __le64 value; 1294 dm_oblock_t oblock; 1295 unsigned flags; 1296 1297 memcpy(&value, leaf, sizeof(value)); 1298 unpack_value(value, &oblock, &flags); 1299 1300 return r; 1301 } 1302 1303 static int __dump_mappings(struct dm_cache_metadata *cmd) 1304 { 1305 return dm_array_walk(&cmd->info, cmd->root, __dump_mapping, NULL); 1306 } 1307 1308 void dm_cache_dump(struct dm_cache_metadata *cmd) 1309 { 1310 READ_LOCK_VOID(cmd); 1311 __dump_mappings(cmd); 1312 READ_UNLOCK(cmd); 1313 } 1314 1315 int dm_cache_changed_this_transaction(struct dm_cache_metadata *cmd) 1316 { 1317 int r; 1318 1319 READ_LOCK(cmd); 1320 r = cmd->changed; 1321 READ_UNLOCK(cmd); 1322 1323 return r; 1324 } 1325 1326 static int __dirty(struct dm_cache_metadata *cmd, dm_cblock_t cblock, bool dirty) 1327 { 1328 int r; 1329 unsigned flags; 1330 dm_oblock_t oblock; 1331 __le64 value; 1332 1333 r = dm_array_get_value(&cmd->info, cmd->root, from_cblock(cblock), &value); 1334 if (r) 1335 return r; 1336 1337 unpack_value(value, &oblock, &flags); 1338 1339 if (((flags & M_DIRTY) && dirty) || (!(flags & M_DIRTY) && !dirty)) 1340 /* nothing to be done */ 1341 return 0; 1342 1343 value = pack_value(oblock, (flags & ~M_DIRTY) | (dirty ? M_DIRTY : 0)); 1344 __dm_bless_for_disk(&value); 1345 1346 r = dm_array_set_value(&cmd->info, cmd->root, from_cblock(cblock), 1347 &value, &cmd->root); 1348 if (r) 1349 return r; 1350 1351 cmd->changed = true; 1352 return 0; 1353 1354 } 1355 1356 int dm_cache_set_dirty(struct dm_cache_metadata *cmd, 1357 dm_cblock_t cblock, bool dirty) 1358 { 1359 int r; 1360 1361 WRITE_LOCK(cmd); 1362 r = __dirty(cmd, cblock, dirty); 1363 WRITE_UNLOCK(cmd); 1364 1365 return r; 1366 } 1367 1368 void dm_cache_metadata_get_stats(struct dm_cache_metadata *cmd, 1369 struct dm_cache_statistics *stats) 1370 { 1371 READ_LOCK_VOID(cmd); 1372 *stats = cmd->stats; 1373 READ_UNLOCK(cmd); 1374 } 1375 1376 void dm_cache_metadata_set_stats(struct dm_cache_metadata *cmd, 1377 struct dm_cache_statistics *stats) 1378 { 1379 WRITE_LOCK_VOID(cmd); 1380 cmd->stats = *stats; 1381 WRITE_UNLOCK(cmd); 1382 } 1383 1384 int dm_cache_commit(struct dm_cache_metadata *cmd, bool clean_shutdown) 1385 { 1386 int r; 1387 flags_mutator mutator = (clean_shutdown ? set_clean_shutdown : 1388 clear_clean_shutdown); 1389 1390 WRITE_LOCK(cmd); 1391 r = __commit_transaction(cmd, mutator); 1392 if (r) 1393 goto out; 1394 1395 r = __begin_transaction(cmd); 1396 1397 out: 1398 WRITE_UNLOCK(cmd); 1399 return r; 1400 } 1401 1402 int dm_cache_get_free_metadata_block_count(struct dm_cache_metadata *cmd, 1403 dm_block_t *result) 1404 { 1405 int r = -EINVAL; 1406 1407 READ_LOCK(cmd); 1408 r = dm_sm_get_nr_free(cmd->metadata_sm, result); 1409 READ_UNLOCK(cmd); 1410 1411 return r; 1412 } 1413 1414 int dm_cache_get_metadata_dev_size(struct dm_cache_metadata *cmd, 1415 dm_block_t *result) 1416 { 1417 int r = -EINVAL; 1418 1419 READ_LOCK(cmd); 1420 r = dm_sm_get_nr_blocks(cmd->metadata_sm, result); 1421 READ_UNLOCK(cmd); 1422 1423 return r; 1424 } 1425 1426 /*----------------------------------------------------------------*/ 1427 1428 static int get_hint(uint32_t index, void *value_le, void *context) 1429 { 1430 uint32_t value; 1431 struct dm_cache_policy *policy = context; 1432 1433 value = policy_get_hint(policy, to_cblock(index)); 1434 *((__le32 *) value_le) = cpu_to_le32(value); 1435 1436 return 0; 1437 } 1438 1439 /* 1440 * It's quicker to always delete the hint array, and recreate with 1441 * dm_array_new(). 1442 */ 1443 static int write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy) 1444 { 1445 int r; 1446 size_t hint_size; 1447 const char *policy_name = dm_cache_policy_get_name(policy); 1448 const unsigned *policy_version = dm_cache_policy_get_version(policy); 1449 1450 if (!policy_name[0] || 1451 (strlen(policy_name) > sizeof(cmd->policy_name) - 1)) 1452 return -EINVAL; 1453 1454 strncpy(cmd->policy_name, policy_name, sizeof(cmd->policy_name)); 1455 memcpy(cmd->policy_version, policy_version, sizeof(cmd->policy_version)); 1456 1457 hint_size = dm_cache_policy_get_hint_size(policy); 1458 if (!hint_size) 1459 return 0; /* short-circuit hints initialization */ 1460 cmd->policy_hint_size = hint_size; 1461 1462 if (cmd->hint_root) { 1463 r = dm_array_del(&cmd->hint_info, cmd->hint_root); 1464 if (r) 1465 return r; 1466 } 1467 1468 return dm_array_new(&cmd->hint_info, &cmd->hint_root, 1469 from_cblock(cmd->cache_blocks), 1470 get_hint, policy); 1471 } 1472 1473 int dm_cache_write_hints(struct dm_cache_metadata *cmd, struct dm_cache_policy *policy) 1474 { 1475 int r; 1476 1477 WRITE_LOCK(cmd); 1478 r = write_hints(cmd, policy); 1479 WRITE_UNLOCK(cmd); 1480 1481 return r; 1482 } 1483 1484 int dm_cache_metadata_all_clean(struct dm_cache_metadata *cmd, bool *result) 1485 { 1486 int r; 1487 1488 READ_LOCK(cmd); 1489 r = blocks_are_unmapped_or_clean(cmd, 0, cmd->cache_blocks, result); 1490 READ_UNLOCK(cmd); 1491 1492 return r; 1493 } 1494 1495 void dm_cache_metadata_set_read_only(struct dm_cache_metadata *cmd) 1496 { 1497 WRITE_LOCK_VOID(cmd); 1498 dm_bm_set_read_only(cmd->bm); 1499 WRITE_UNLOCK(cmd); 1500 } 1501 1502 void dm_cache_metadata_set_read_write(struct dm_cache_metadata *cmd) 1503 { 1504 WRITE_LOCK_VOID(cmd); 1505 dm_bm_set_read_write(cmd->bm); 1506 WRITE_UNLOCK(cmd); 1507 } 1508 1509 int dm_cache_metadata_set_needs_check(struct dm_cache_metadata *cmd) 1510 { 1511 int r; 1512 struct dm_block *sblock; 1513 struct cache_disk_superblock *disk_super; 1514 1515 WRITE_LOCK(cmd); 1516 set_bit(NEEDS_CHECK, &cmd->flags); 1517 1518 r = superblock_lock(cmd, &sblock); 1519 if (r) { 1520 DMERR("couldn't read superblock"); 1521 goto out; 1522 } 1523 1524 disk_super = dm_block_data(sblock); 1525 disk_super->flags = cpu_to_le32(cmd->flags); 1526 1527 dm_bm_unlock(sblock); 1528 1529 out: 1530 WRITE_UNLOCK(cmd); 1531 return r; 1532 } 1533 1534 int dm_cache_metadata_needs_check(struct dm_cache_metadata *cmd, bool *result) 1535 { 1536 READ_LOCK(cmd); 1537 *result = !!test_bit(NEEDS_CHECK, &cmd->flags); 1538 READ_UNLOCK(cmd); 1539 1540 return 0; 1541 } 1542 1543 int dm_cache_metadata_abort(struct dm_cache_metadata *cmd) 1544 { 1545 int r; 1546 1547 WRITE_LOCK(cmd); 1548 __destroy_persistent_data_objects(cmd); 1549 r = __create_persistent_data_objects(cmd, false); 1550 if (r) 1551 cmd->fail_io = true; 1552 WRITE_UNLOCK(cmd); 1553 1554 return r; 1555 } 1556