1/* 2 * Copyright (C) 2011-2012 Red Hat, Inc. 3 * 4 * This file is released under the GPL. 5 */ 6 7#include "dm-thin-metadata.h" 8#include "persistent-data/dm-btree.h" 9#include "persistent-data/dm-space-map.h" 10#include "persistent-data/dm-space-map-disk.h" 11#include "persistent-data/dm-transaction-manager.h" 12 13#include <linux/list.h> 14#include <linux/device-mapper.h> 15#include <linux/workqueue.h> 16 17/*-------------------------------------------------------------------------- 18 * As far as the metadata goes, there is: 19 * 20 * - A superblock in block zero, taking up fewer than 512 bytes for 21 * atomic writes. 22 * 23 * - A space map managing the metadata blocks. 24 * 25 * - A space map managing the data blocks. 26 * 27 * - A btree mapping our internal thin dev ids onto struct disk_device_details. 28 * 29 * - A hierarchical btree, with 2 levels which effectively maps (thin 30 * dev id, virtual block) -> block_time. Block time is a 64-bit 31 * field holding the time in the low 24 bits, and block in the top 48 32 * bits. 33 * 34 * BTrees consist solely of btree_nodes, that fill a block. Some are 35 * internal nodes, as such their values are a __le64 pointing to other 36 * nodes. Leaf nodes can store data of any reasonable size (ie. much 37 * smaller than the block size). The nodes consist of the header, 38 * followed by an array of keys, followed by an array of values. We have 39 * to binary search on the keys so they're all held together to help the 40 * cpu cache. 41 * 42 * Space maps have 2 btrees: 43 * 44 * - One maps a uint64_t onto a struct index_entry. Which points to a 45 * bitmap block, and has some details about how many free entries there 46 * are etc. 47 * 48 * - The bitmap blocks have a header (for the checksum). Then the rest 49 * of the block is pairs of bits. With the meaning being: 50 * 51 * 0 - ref count is 0 52 * 1 - ref count is 1 53 * 2 - ref count is 2 54 * 3 - ref count is higher than 2 55 * 56 * - If the count is higher than 2 then the ref count is entered in a 57 * second btree that directly maps the block_address to a uint32_t ref 58 * count. 59 * 60 * The space map metadata variant doesn't have a bitmaps btree. Instead 61 * it has one single blocks worth of index_entries. This avoids 62 * recursive issues with the bitmap btree needing to allocate space in 63 * order to insert. With a small data block size such as 64k the 64 * metadata support data devices that are hundreds of terrabytes. 65 * 66 * The space maps allocate space linearly from front to back. Space that 67 * is freed in a transaction is never recycled within that transaction. 68 * To try and avoid fragmenting _free_ space the allocator always goes 69 * back and fills in gaps. 70 * 71 * All metadata io is in THIN_METADATA_BLOCK_SIZE sized/aligned chunks 72 * from the block manager. 73 *--------------------------------------------------------------------------*/ 74 75#define DM_MSG_PREFIX "thin metadata" 76 77#define THIN_SUPERBLOCK_MAGIC 27022010 78#define THIN_SUPERBLOCK_LOCATION 0 79#define THIN_VERSION 2 80#define THIN_METADATA_CACHE_SIZE 64 81#define SECTOR_TO_BLOCK_SHIFT 3 82 83/* 84 * 3 for btree insert + 85 * 2 for btree lookup used within space map 86 */ 87#define THIN_MAX_CONCURRENT_LOCKS 5 88 89/* This should be plenty */ 90#define SPACE_MAP_ROOT_SIZE 128 91 92/* 93 * Little endian on-disk superblock and device details. 94 */ 95struct thin_disk_superblock { 96 __le32 csum; /* Checksum of superblock except for this field. */ 97 __le32 flags; 98 __le64 blocknr; /* This block number, dm_block_t. */ 99 100 __u8 uuid[16]; 101 __le64 magic; 102 __le32 version; 103 __le32 time; 104 105 __le64 trans_id; 106 107 /* 108 * Root held by userspace transactions. 109 */ 110 __le64 held_root; 111 112 __u8 data_space_map_root[SPACE_MAP_ROOT_SIZE]; 113 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE]; 114 115 /* 116 * 2-level btree mapping (dev_id, (dev block, time)) -> data block 117 */ 118 __le64 data_mapping_root; 119 120 /* 121 * Device detail root mapping dev_id -> device_details 122 */ 123 __le64 device_details_root; 124 125 __le32 data_block_size; /* In 512-byte sectors. */ 126 127 __le32 metadata_block_size; /* In 512-byte sectors. */ 128 __le64 metadata_nr_blocks; 129 130 __le32 compat_flags; 131 __le32 compat_ro_flags; 132 __le32 incompat_flags; 133} __packed; 134 135struct disk_device_details { 136 __le64 mapped_blocks; 137 __le64 transaction_id; /* When created. */ 138 __le32 creation_time; 139 __le32 snapshotted_time; 140} __packed; 141 142struct dm_pool_metadata { 143 struct hlist_node hash; 144 145 struct block_device *bdev; 146 struct dm_block_manager *bm; 147 struct dm_space_map *metadata_sm; 148 struct dm_space_map *data_sm; 149 struct dm_transaction_manager *tm; 150 struct dm_transaction_manager *nb_tm; 151 152 /* 153 * Two-level btree. 154 * First level holds thin_dev_t. 155 * Second level holds mappings. 156 */ 157 struct dm_btree_info info; 158 159 /* 160 * Non-blocking version of the above. 161 */ 162 struct dm_btree_info nb_info; 163 164 /* 165 * Just the top level for deleting whole devices. 166 */ 167 struct dm_btree_info tl_info; 168 169 /* 170 * Just the bottom level for creating new devices. 171 */ 172 struct dm_btree_info bl_info; 173 174 /* 175 * Describes the device details btree. 176 */ 177 struct dm_btree_info details_info; 178 179 struct rw_semaphore root_lock; 180 uint32_t time; 181 dm_block_t root; 182 dm_block_t details_root; 183 struct list_head thin_devices; 184 uint64_t trans_id; 185 unsigned long flags; 186 sector_t data_block_size; 187 188 /* 189 * Set if a transaction has to be aborted but the attempt to roll back 190 * to the previous (good) transaction failed. The only pool metadata 191 * operation possible in this state is the closing of the device. 192 */ 193 bool fail_io:1; 194 195 /* 196 * Reading the space map roots can fail, so we read it into these 197 * buffers before the superblock is locked and updated. 198 */ 199 __u8 data_space_map_root[SPACE_MAP_ROOT_SIZE]; 200 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE]; 201}; 202 203struct dm_thin_device { 204 struct list_head list; 205 struct dm_pool_metadata *pmd; 206 dm_thin_id id; 207 208 int open_count; 209 bool changed:1; 210 bool aborted_with_changes:1; 211 uint64_t mapped_blocks; 212 uint64_t transaction_id; 213 uint32_t creation_time; 214 uint32_t snapshotted_time; 215}; 216 217/*---------------------------------------------------------------- 218 * superblock validator 219 *--------------------------------------------------------------*/ 220 221#define SUPERBLOCK_CSUM_XOR 160774 222 223static void sb_prepare_for_write(struct dm_block_validator *v, 224 struct dm_block *b, 225 size_t block_size) 226{ 227 struct thin_disk_superblock *disk_super = dm_block_data(b); 228 229 disk_super->blocknr = cpu_to_le64(dm_block_location(b)); 230 disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags, 231 block_size - sizeof(__le32), 232 SUPERBLOCK_CSUM_XOR)); 233} 234 235static int sb_check(struct dm_block_validator *v, 236 struct dm_block *b, 237 size_t block_size) 238{ 239 struct thin_disk_superblock *disk_super = dm_block_data(b); 240 __le32 csum_le; 241 242 if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) { 243 DMERR("sb_check failed: blocknr %llu: " 244 "wanted %llu", le64_to_cpu(disk_super->blocknr), 245 (unsigned long long)dm_block_location(b)); 246 return -ENOTBLK; 247 } 248 249 if (le64_to_cpu(disk_super->magic) != THIN_SUPERBLOCK_MAGIC) { 250 DMERR("sb_check failed: magic %llu: " 251 "wanted %llu", le64_to_cpu(disk_super->magic), 252 (unsigned long long)THIN_SUPERBLOCK_MAGIC); 253 return -EILSEQ; 254 } 255 256 csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags, 257 block_size - sizeof(__le32), 258 SUPERBLOCK_CSUM_XOR)); 259 if (csum_le != disk_super->csum) { 260 DMERR("sb_check failed: csum %u: wanted %u", 261 le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum)); 262 return -EILSEQ; 263 } 264 265 return 0; 266} 267 268static struct dm_block_validator sb_validator = { 269 .name = "superblock", 270 .prepare_for_write = sb_prepare_for_write, 271 .check = sb_check 272}; 273 274/*---------------------------------------------------------------- 275 * Methods for the btree value types 276 *--------------------------------------------------------------*/ 277 278static uint64_t pack_block_time(dm_block_t b, uint32_t t) 279{ 280 return (b << 24) | t; 281} 282 283static void unpack_block_time(uint64_t v, dm_block_t *b, uint32_t *t) 284{ 285 *b = v >> 24; 286 *t = v & ((1 << 24) - 1); 287} 288 289static void data_block_inc(void *context, const void *value_le) 290{ 291 struct dm_space_map *sm = context; 292 __le64 v_le; 293 uint64_t b; 294 uint32_t t; 295 296 memcpy(&v_le, value_le, sizeof(v_le)); 297 unpack_block_time(le64_to_cpu(v_le), &b, &t); 298 dm_sm_inc_block(sm, b); 299} 300 301static void data_block_dec(void *context, const void *value_le) 302{ 303 struct dm_space_map *sm = context; 304 __le64 v_le; 305 uint64_t b; 306 uint32_t t; 307 308 memcpy(&v_le, value_le, sizeof(v_le)); 309 unpack_block_time(le64_to_cpu(v_le), &b, &t); 310 dm_sm_dec_block(sm, b); 311} 312 313static int data_block_equal(void *context, const void *value1_le, const void *value2_le) 314{ 315 __le64 v1_le, v2_le; 316 uint64_t b1, b2; 317 uint32_t t; 318 319 memcpy(&v1_le, value1_le, sizeof(v1_le)); 320 memcpy(&v2_le, value2_le, sizeof(v2_le)); 321 unpack_block_time(le64_to_cpu(v1_le), &b1, &t); 322 unpack_block_time(le64_to_cpu(v2_le), &b2, &t); 323 324 return b1 == b2; 325} 326 327static void subtree_inc(void *context, const void *value) 328{ 329 struct dm_btree_info *info = context; 330 __le64 root_le; 331 uint64_t root; 332 333 memcpy(&root_le, value, sizeof(root_le)); 334 root = le64_to_cpu(root_le); 335 dm_tm_inc(info->tm, root); 336} 337 338static void subtree_dec(void *context, const void *value) 339{ 340 struct dm_btree_info *info = context; 341 __le64 root_le; 342 uint64_t root; 343 344 memcpy(&root_le, value, sizeof(root_le)); 345 root = le64_to_cpu(root_le); 346 if (dm_btree_del(info, root)) 347 DMERR("btree delete failed\n"); 348} 349 350static int subtree_equal(void *context, const void *value1_le, const void *value2_le) 351{ 352 __le64 v1_le, v2_le; 353 memcpy(&v1_le, value1_le, sizeof(v1_le)); 354 memcpy(&v2_le, value2_le, sizeof(v2_le)); 355 356 return v1_le == v2_le; 357} 358 359/*----------------------------------------------------------------*/ 360 361static int superblock_lock_zero(struct dm_pool_metadata *pmd, 362 struct dm_block **sblock) 363{ 364 return dm_bm_write_lock_zero(pmd->bm, THIN_SUPERBLOCK_LOCATION, 365 &sb_validator, sblock); 366} 367 368static int superblock_lock(struct dm_pool_metadata *pmd, 369 struct dm_block **sblock) 370{ 371 return dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION, 372 &sb_validator, sblock); 373} 374 375static int __superblock_all_zeroes(struct dm_block_manager *bm, int *result) 376{ 377 int r; 378 unsigned i; 379 struct dm_block *b; 380 __le64 *data_le, zero = cpu_to_le64(0); 381 unsigned block_size = dm_bm_block_size(bm) / sizeof(__le64); 382 383 /* 384 * We can't use a validator here - it may be all zeroes. 385 */ 386 r = dm_bm_read_lock(bm, THIN_SUPERBLOCK_LOCATION, NULL, &b); 387 if (r) 388 return r; 389 390 data_le = dm_block_data(b); 391 *result = 1; 392 for (i = 0; i < block_size; i++) { 393 if (data_le[i] != zero) { 394 *result = 0; 395 break; 396 } 397 } 398 399 dm_bm_unlock(b); 400 401 return 0; 402} 403 404static void __setup_btree_details(struct dm_pool_metadata *pmd) 405{ 406 pmd->info.tm = pmd->tm; 407 pmd->info.levels = 2; 408 pmd->info.value_type.context = pmd->data_sm; 409 pmd->info.value_type.size = sizeof(__le64); 410 pmd->info.value_type.inc = data_block_inc; 411 pmd->info.value_type.dec = data_block_dec; 412 pmd->info.value_type.equal = data_block_equal; 413 414 memcpy(&pmd->nb_info, &pmd->info, sizeof(pmd->nb_info)); 415 pmd->nb_info.tm = pmd->nb_tm; 416 417 pmd->tl_info.tm = pmd->tm; 418 pmd->tl_info.levels = 1; 419 pmd->tl_info.value_type.context = &pmd->bl_info; 420 pmd->tl_info.value_type.size = sizeof(__le64); 421 pmd->tl_info.value_type.inc = subtree_inc; 422 pmd->tl_info.value_type.dec = subtree_dec; 423 pmd->tl_info.value_type.equal = subtree_equal; 424 425 pmd->bl_info.tm = pmd->tm; 426 pmd->bl_info.levels = 1; 427 pmd->bl_info.value_type.context = pmd->data_sm; 428 pmd->bl_info.value_type.size = sizeof(__le64); 429 pmd->bl_info.value_type.inc = data_block_inc; 430 pmd->bl_info.value_type.dec = data_block_dec; 431 pmd->bl_info.value_type.equal = data_block_equal; 432 433 pmd->details_info.tm = pmd->tm; 434 pmd->details_info.levels = 1; 435 pmd->details_info.value_type.context = NULL; 436 pmd->details_info.value_type.size = sizeof(struct disk_device_details); 437 pmd->details_info.value_type.inc = NULL; 438 pmd->details_info.value_type.dec = NULL; 439 pmd->details_info.value_type.equal = NULL; 440} 441 442static int save_sm_roots(struct dm_pool_metadata *pmd) 443{ 444 int r; 445 size_t len; 446 447 r = dm_sm_root_size(pmd->metadata_sm, &len); 448 if (r < 0) 449 return r; 450 451 r = dm_sm_copy_root(pmd->metadata_sm, &pmd->metadata_space_map_root, len); 452 if (r < 0) 453 return r; 454 455 r = dm_sm_root_size(pmd->data_sm, &len); 456 if (r < 0) 457 return r; 458 459 return dm_sm_copy_root(pmd->data_sm, &pmd->data_space_map_root, len); 460} 461 462static void copy_sm_roots(struct dm_pool_metadata *pmd, 463 struct thin_disk_superblock *disk) 464{ 465 memcpy(&disk->metadata_space_map_root, 466 &pmd->metadata_space_map_root, 467 sizeof(pmd->metadata_space_map_root)); 468 469 memcpy(&disk->data_space_map_root, 470 &pmd->data_space_map_root, 471 sizeof(pmd->data_space_map_root)); 472} 473 474static int __write_initial_superblock(struct dm_pool_metadata *pmd) 475{ 476 int r; 477 struct dm_block *sblock; 478 struct thin_disk_superblock *disk_super; 479 sector_t bdev_size = i_size_read(pmd->bdev->bd_inode) >> SECTOR_SHIFT; 480 481 if (bdev_size > THIN_METADATA_MAX_SECTORS) 482 bdev_size = THIN_METADATA_MAX_SECTORS; 483 484 r = dm_sm_commit(pmd->data_sm); 485 if (r < 0) 486 return r; 487 488 r = save_sm_roots(pmd); 489 if (r < 0) 490 return r; 491 492 r = dm_tm_pre_commit(pmd->tm); 493 if (r < 0) 494 return r; 495 496 r = superblock_lock_zero(pmd, &sblock); 497 if (r) 498 return r; 499 500 disk_super = dm_block_data(sblock); 501 disk_super->flags = 0; 502 memset(disk_super->uuid, 0, sizeof(disk_super->uuid)); 503 disk_super->magic = cpu_to_le64(THIN_SUPERBLOCK_MAGIC); 504 disk_super->version = cpu_to_le32(THIN_VERSION); 505 disk_super->time = 0; 506 disk_super->trans_id = 0; 507 disk_super->held_root = 0; 508 509 copy_sm_roots(pmd, disk_super); 510 511 disk_super->data_mapping_root = cpu_to_le64(pmd->root); 512 disk_super->device_details_root = cpu_to_le64(pmd->details_root); 513 disk_super->metadata_block_size = cpu_to_le32(THIN_METADATA_BLOCK_SIZE); 514 disk_super->metadata_nr_blocks = cpu_to_le64(bdev_size >> SECTOR_TO_BLOCK_SHIFT); 515 disk_super->data_block_size = cpu_to_le32(pmd->data_block_size); 516 517 return dm_tm_commit(pmd->tm, sblock); 518} 519 520static int __format_metadata(struct dm_pool_metadata *pmd) 521{ 522 int r; 523 524 r = dm_tm_create_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION, 525 &pmd->tm, &pmd->metadata_sm); 526 if (r < 0) { 527 DMERR("tm_create_with_sm failed"); 528 return r; 529 } 530 531 pmd->data_sm = dm_sm_disk_create(pmd->tm, 0); 532 if (IS_ERR(pmd->data_sm)) { 533 DMERR("sm_disk_create failed"); 534 r = PTR_ERR(pmd->data_sm); 535 goto bad_cleanup_tm; 536 } 537 538 pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm); 539 if (!pmd->nb_tm) { 540 DMERR("could not create non-blocking clone tm"); 541 r = -ENOMEM; 542 goto bad_cleanup_data_sm; 543 } 544 545 __setup_btree_details(pmd); 546 547 r = dm_btree_empty(&pmd->info, &pmd->root); 548 if (r < 0) 549 goto bad_cleanup_nb_tm; 550 551 r = dm_btree_empty(&pmd->details_info, &pmd->details_root); 552 if (r < 0) { 553 DMERR("couldn't create devices root"); 554 goto bad_cleanup_nb_tm; 555 } 556 557 r = __write_initial_superblock(pmd); 558 if (r) 559 goto bad_cleanup_nb_tm; 560 561 return 0; 562 563bad_cleanup_nb_tm: 564 dm_tm_destroy(pmd->nb_tm); 565bad_cleanup_data_sm: 566 dm_sm_destroy(pmd->data_sm); 567bad_cleanup_tm: 568 dm_tm_destroy(pmd->tm); 569 dm_sm_destroy(pmd->metadata_sm); 570 571 return r; 572} 573 574static int __check_incompat_features(struct thin_disk_superblock *disk_super, 575 struct dm_pool_metadata *pmd) 576{ 577 uint32_t features; 578 579 features = le32_to_cpu(disk_super->incompat_flags) & ~THIN_FEATURE_INCOMPAT_SUPP; 580 if (features) { 581 DMERR("could not access metadata due to unsupported optional features (%lx).", 582 (unsigned long)features); 583 return -EINVAL; 584 } 585 586 /* 587 * Check for read-only metadata to skip the following RDWR checks. 588 */ 589 if (get_disk_ro(pmd->bdev->bd_disk)) 590 return 0; 591 592 features = le32_to_cpu(disk_super->compat_ro_flags) & ~THIN_FEATURE_COMPAT_RO_SUPP; 593 if (features) { 594 DMERR("could not access metadata RDWR due to unsupported optional features (%lx).", 595 (unsigned long)features); 596 return -EINVAL; 597 } 598 599 return 0; 600} 601 602static int __open_metadata(struct dm_pool_metadata *pmd) 603{ 604 int r; 605 struct dm_block *sblock; 606 struct thin_disk_superblock *disk_super; 607 608 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION, 609 &sb_validator, &sblock); 610 if (r < 0) { 611 DMERR("couldn't read superblock"); 612 return r; 613 } 614 615 disk_super = dm_block_data(sblock); 616 617 /* Verify the data block size hasn't changed */ 618 if (le32_to_cpu(disk_super->data_block_size) != pmd->data_block_size) { 619 DMERR("changing the data block size (from %u to %llu) is not supported", 620 le32_to_cpu(disk_super->data_block_size), 621 (unsigned long long)pmd->data_block_size); 622 r = -EINVAL; 623 goto bad_unlock_sblock; 624 } 625 626 r = __check_incompat_features(disk_super, pmd); 627 if (r < 0) 628 goto bad_unlock_sblock; 629 630 r = dm_tm_open_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION, 631 disk_super->metadata_space_map_root, 632 sizeof(disk_super->metadata_space_map_root), 633 &pmd->tm, &pmd->metadata_sm); 634 if (r < 0) { 635 DMERR("tm_open_with_sm failed"); 636 goto bad_unlock_sblock; 637 } 638 639 pmd->data_sm = dm_sm_disk_open(pmd->tm, disk_super->data_space_map_root, 640 sizeof(disk_super->data_space_map_root)); 641 if (IS_ERR(pmd->data_sm)) { 642 DMERR("sm_disk_open failed"); 643 r = PTR_ERR(pmd->data_sm); 644 goto bad_cleanup_tm; 645 } 646 647 pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm); 648 if (!pmd->nb_tm) { 649 DMERR("could not create non-blocking clone tm"); 650 r = -ENOMEM; 651 goto bad_cleanup_data_sm; 652 } 653 654 __setup_btree_details(pmd); 655 dm_bm_unlock(sblock); 656 657 return 0; 658 659bad_cleanup_data_sm: 660 dm_sm_destroy(pmd->data_sm); 661bad_cleanup_tm: 662 dm_tm_destroy(pmd->tm); 663 dm_sm_destroy(pmd->metadata_sm); 664bad_unlock_sblock: 665 dm_bm_unlock(sblock); 666 667 return r; 668} 669 670static int __open_or_format_metadata(struct dm_pool_metadata *pmd, bool format_device) 671{ 672 int r, unformatted; 673 674 r = __superblock_all_zeroes(pmd->bm, &unformatted); 675 if (r) 676 return r; 677 678 if (unformatted) 679 return format_device ? __format_metadata(pmd) : -EPERM; 680 681 return __open_metadata(pmd); 682} 683 684static int __create_persistent_data_objects(struct dm_pool_metadata *pmd, bool format_device) 685{ 686 int r; 687 688 pmd->bm = dm_block_manager_create(pmd->bdev, THIN_METADATA_BLOCK_SIZE << SECTOR_SHIFT, 689 THIN_METADATA_CACHE_SIZE, 690 THIN_MAX_CONCURRENT_LOCKS); 691 if (IS_ERR(pmd->bm)) { 692 DMERR("could not create block manager"); 693 return PTR_ERR(pmd->bm); 694 } 695 696 r = __open_or_format_metadata(pmd, format_device); 697 if (r) 698 dm_block_manager_destroy(pmd->bm); 699 700 return r; 701} 702 703static void __destroy_persistent_data_objects(struct dm_pool_metadata *pmd) 704{ 705 dm_sm_destroy(pmd->data_sm); 706 dm_sm_destroy(pmd->metadata_sm); 707 dm_tm_destroy(pmd->nb_tm); 708 dm_tm_destroy(pmd->tm); 709 dm_block_manager_destroy(pmd->bm); 710} 711 712static int __begin_transaction(struct dm_pool_metadata *pmd) 713{ 714 int r; 715 struct thin_disk_superblock *disk_super; 716 struct dm_block *sblock; 717 718 /* 719 * We re-read the superblock every time. Shouldn't need to do this 720 * really. 721 */ 722 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION, 723 &sb_validator, &sblock); 724 if (r) 725 return r; 726 727 disk_super = dm_block_data(sblock); 728 pmd->time = le32_to_cpu(disk_super->time); 729 pmd->root = le64_to_cpu(disk_super->data_mapping_root); 730 pmd->details_root = le64_to_cpu(disk_super->device_details_root); 731 pmd->trans_id = le64_to_cpu(disk_super->trans_id); 732 pmd->flags = le32_to_cpu(disk_super->flags); 733 pmd->data_block_size = le32_to_cpu(disk_super->data_block_size); 734 735 dm_bm_unlock(sblock); 736 return 0; 737} 738 739static int __write_changed_details(struct dm_pool_metadata *pmd) 740{ 741 int r; 742 struct dm_thin_device *td, *tmp; 743 struct disk_device_details details; 744 uint64_t key; 745 746 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) { 747 if (!td->changed) 748 continue; 749 750 key = td->id; 751 752 details.mapped_blocks = cpu_to_le64(td->mapped_blocks); 753 details.transaction_id = cpu_to_le64(td->transaction_id); 754 details.creation_time = cpu_to_le32(td->creation_time); 755 details.snapshotted_time = cpu_to_le32(td->snapshotted_time); 756 __dm_bless_for_disk(&details); 757 758 r = dm_btree_insert(&pmd->details_info, pmd->details_root, 759 &key, &details, &pmd->details_root); 760 if (r) 761 return r; 762 763 if (td->open_count) 764 td->changed = 0; 765 else { 766 list_del(&td->list); 767 kfree(td); 768 } 769 } 770 771 return 0; 772} 773 774static int __commit_transaction(struct dm_pool_metadata *pmd) 775{ 776 int r; 777 size_t metadata_len, data_len; 778 struct thin_disk_superblock *disk_super; 779 struct dm_block *sblock; 780 781 /* 782 * We need to know if the thin_disk_superblock exceeds a 512-byte sector. 783 */ 784 BUILD_BUG_ON(sizeof(struct thin_disk_superblock) > 512); 785 786 r = __write_changed_details(pmd); 787 if (r < 0) 788 return r; 789 790 r = dm_sm_commit(pmd->data_sm); 791 if (r < 0) 792 return r; 793 794 r = dm_tm_pre_commit(pmd->tm); 795 if (r < 0) 796 return r; 797 798 r = dm_sm_root_size(pmd->metadata_sm, &metadata_len); 799 if (r < 0) 800 return r; 801 802 r = dm_sm_root_size(pmd->data_sm, &data_len); 803 if (r < 0) 804 return r; 805 806 r = save_sm_roots(pmd); 807 if (r < 0) 808 return r; 809 810 r = superblock_lock(pmd, &sblock); 811 if (r) 812 return r; 813 814 disk_super = dm_block_data(sblock); 815 disk_super->time = cpu_to_le32(pmd->time); 816 disk_super->data_mapping_root = cpu_to_le64(pmd->root); 817 disk_super->device_details_root = cpu_to_le64(pmd->details_root); 818 disk_super->trans_id = cpu_to_le64(pmd->trans_id); 819 disk_super->flags = cpu_to_le32(pmd->flags); 820 821 copy_sm_roots(pmd, disk_super); 822 823 return dm_tm_commit(pmd->tm, sblock); 824} 825 826struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev, 827 sector_t data_block_size, 828 bool format_device) 829{ 830 int r; 831 struct dm_pool_metadata *pmd; 832 833 pmd = kmalloc(sizeof(*pmd), GFP_KERNEL); 834 if (!pmd) { 835 DMERR("could not allocate metadata struct"); 836 return ERR_PTR(-ENOMEM); 837 } 838 839 init_rwsem(&pmd->root_lock); 840 pmd->time = 0; 841 INIT_LIST_HEAD(&pmd->thin_devices); 842 pmd->fail_io = false; 843 pmd->bdev = bdev; 844 pmd->data_block_size = data_block_size; 845 846 r = __create_persistent_data_objects(pmd, format_device); 847 if (r) { 848 kfree(pmd); 849 return ERR_PTR(r); 850 } 851 852 r = __begin_transaction(pmd); 853 if (r < 0) { 854 if (dm_pool_metadata_close(pmd) < 0) 855 DMWARN("%s: dm_pool_metadata_close() failed.", __func__); 856 return ERR_PTR(r); 857 } 858 859 return pmd; 860} 861 862int dm_pool_metadata_close(struct dm_pool_metadata *pmd) 863{ 864 int r; 865 unsigned open_devices = 0; 866 struct dm_thin_device *td, *tmp; 867 868 down_read(&pmd->root_lock); 869 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) { 870 if (td->open_count) 871 open_devices++; 872 else { 873 list_del(&td->list); 874 kfree(td); 875 } 876 } 877 up_read(&pmd->root_lock); 878 879 if (open_devices) { 880 DMERR("attempt to close pmd when %u device(s) are still open", 881 open_devices); 882 return -EBUSY; 883 } 884 885 if (!dm_bm_is_read_only(pmd->bm) && !pmd->fail_io) { 886 r = __commit_transaction(pmd); 887 if (r < 0) 888 DMWARN("%s: __commit_transaction() failed, error = %d", 889 __func__, r); 890 } 891 892 if (!pmd->fail_io) 893 __destroy_persistent_data_objects(pmd); 894 895 kfree(pmd); 896 return 0; 897} 898 899/* 900 * __open_device: Returns @td corresponding to device with id @dev, 901 * creating it if @create is set and incrementing @td->open_count. 902 * On failure, @td is undefined. 903 */ 904static int __open_device(struct dm_pool_metadata *pmd, 905 dm_thin_id dev, int create, 906 struct dm_thin_device **td) 907{ 908 int r, changed = 0; 909 struct dm_thin_device *td2; 910 uint64_t key = dev; 911 struct disk_device_details details_le; 912 913 /* 914 * If the device is already open, return it. 915 */ 916 list_for_each_entry(td2, &pmd->thin_devices, list) 917 if (td2->id == dev) { 918 /* 919 * May not create an already-open device. 920 */ 921 if (create) 922 return -EEXIST; 923 924 td2->open_count++; 925 *td = td2; 926 return 0; 927 } 928 929 /* 930 * Check the device exists. 931 */ 932 r = dm_btree_lookup(&pmd->details_info, pmd->details_root, 933 &key, &details_le); 934 if (r) { 935 if (r != -ENODATA || !create) 936 return r; 937 938 /* 939 * Create new device. 940 */ 941 changed = 1; 942 details_le.mapped_blocks = 0; 943 details_le.transaction_id = cpu_to_le64(pmd->trans_id); 944 details_le.creation_time = cpu_to_le32(pmd->time); 945 details_le.snapshotted_time = cpu_to_le32(pmd->time); 946 } 947 948 *td = kmalloc(sizeof(**td), GFP_NOIO); 949 if (!*td) 950 return -ENOMEM; 951 952 (*td)->pmd = pmd; 953 (*td)->id = dev; 954 (*td)->open_count = 1; 955 (*td)->changed = changed; 956 (*td)->aborted_with_changes = false; 957 (*td)->mapped_blocks = le64_to_cpu(details_le.mapped_blocks); 958 (*td)->transaction_id = le64_to_cpu(details_le.transaction_id); 959 (*td)->creation_time = le32_to_cpu(details_le.creation_time); 960 (*td)->snapshotted_time = le32_to_cpu(details_le.snapshotted_time); 961 962 list_add(&(*td)->list, &pmd->thin_devices); 963 964 return 0; 965} 966 967static void __close_device(struct dm_thin_device *td) 968{ 969 --td->open_count; 970} 971 972static int __create_thin(struct dm_pool_metadata *pmd, 973 dm_thin_id dev) 974{ 975 int r; 976 dm_block_t dev_root; 977 uint64_t key = dev; 978 struct disk_device_details details_le; 979 struct dm_thin_device *td; 980 __le64 value; 981 982 r = dm_btree_lookup(&pmd->details_info, pmd->details_root, 983 &key, &details_le); 984 if (!r) 985 return -EEXIST; 986 987 /* 988 * Create an empty btree for the mappings. 989 */ 990 r = dm_btree_empty(&pmd->bl_info, &dev_root); 991 if (r) 992 return r; 993 994 /* 995 * Insert it into the main mapping tree. 996 */ 997 value = cpu_to_le64(dev_root); 998 __dm_bless_for_disk(&value); 999 r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root); 1000 if (r) { 1001 dm_btree_del(&pmd->bl_info, dev_root); 1002 return r; 1003 } 1004 1005 r = __open_device(pmd, dev, 1, &td); 1006 if (r) { 1007 dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root); 1008 dm_btree_del(&pmd->bl_info, dev_root); 1009 return r; 1010 } 1011 __close_device(td); 1012 1013 return r; 1014} 1015 1016int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev) 1017{ 1018 int r = -EINVAL; 1019 1020 down_write(&pmd->root_lock); 1021 if (!pmd->fail_io) 1022 r = __create_thin(pmd, dev); 1023 up_write(&pmd->root_lock); 1024 1025 return r; 1026} 1027 1028static int __set_snapshot_details(struct dm_pool_metadata *pmd, 1029 struct dm_thin_device *snap, 1030 dm_thin_id origin, uint32_t time) 1031{ 1032 int r; 1033 struct dm_thin_device *td; 1034 1035 r = __open_device(pmd, origin, 0, &td); 1036 if (r) 1037 return r; 1038 1039 td->changed = 1; 1040 td->snapshotted_time = time; 1041 1042 snap->mapped_blocks = td->mapped_blocks; 1043 snap->snapshotted_time = time; 1044 __close_device(td); 1045 1046 return 0; 1047} 1048 1049static int __create_snap(struct dm_pool_metadata *pmd, 1050 dm_thin_id dev, dm_thin_id origin) 1051{ 1052 int r; 1053 dm_block_t origin_root; 1054 uint64_t key = origin, dev_key = dev; 1055 struct dm_thin_device *td; 1056 struct disk_device_details details_le; 1057 __le64 value; 1058 1059 /* check this device is unused */ 1060 r = dm_btree_lookup(&pmd->details_info, pmd->details_root, 1061 &dev_key, &details_le); 1062 if (!r) 1063 return -EEXIST; 1064 1065 /* find the mapping tree for the origin */ 1066 r = dm_btree_lookup(&pmd->tl_info, pmd->root, &key, &value); 1067 if (r) 1068 return r; 1069 origin_root = le64_to_cpu(value); 1070 1071 /* clone the origin, an inc will do */ 1072 dm_tm_inc(pmd->tm, origin_root); 1073 1074 /* insert into the main mapping tree */ 1075 value = cpu_to_le64(origin_root); 1076 __dm_bless_for_disk(&value); 1077 key = dev; 1078 r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root); 1079 if (r) { 1080 dm_tm_dec(pmd->tm, origin_root); 1081 return r; 1082 } 1083 1084 pmd->time++; 1085 1086 r = __open_device(pmd, dev, 1, &td); 1087 if (r) 1088 goto bad; 1089 1090 r = __set_snapshot_details(pmd, td, origin, pmd->time); 1091 __close_device(td); 1092 1093 if (r) 1094 goto bad; 1095 1096 return 0; 1097 1098bad: 1099 dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root); 1100 dm_btree_remove(&pmd->details_info, pmd->details_root, 1101 &key, &pmd->details_root); 1102 return r; 1103} 1104 1105int dm_pool_create_snap(struct dm_pool_metadata *pmd, 1106 dm_thin_id dev, 1107 dm_thin_id origin) 1108{ 1109 int r = -EINVAL; 1110 1111 down_write(&pmd->root_lock); 1112 if (!pmd->fail_io) 1113 r = __create_snap(pmd, dev, origin); 1114 up_write(&pmd->root_lock); 1115 1116 return r; 1117} 1118 1119static int __delete_device(struct dm_pool_metadata *pmd, dm_thin_id dev) 1120{ 1121 int r; 1122 uint64_t key = dev; 1123 struct dm_thin_device *td; 1124 1125 /* TODO: failure should mark the transaction invalid */ 1126 r = __open_device(pmd, dev, 0, &td); 1127 if (r) 1128 return r; 1129 1130 if (td->open_count > 1) { 1131 __close_device(td); 1132 return -EBUSY; 1133 } 1134 1135 list_del(&td->list); 1136 kfree(td); 1137 r = dm_btree_remove(&pmd->details_info, pmd->details_root, 1138 &key, &pmd->details_root); 1139 if (r) 1140 return r; 1141 1142 r = dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root); 1143 if (r) 1144 return r; 1145 1146 return 0; 1147} 1148 1149int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd, 1150 dm_thin_id dev) 1151{ 1152 int r = -EINVAL; 1153 1154 down_write(&pmd->root_lock); 1155 if (!pmd->fail_io) 1156 r = __delete_device(pmd, dev); 1157 up_write(&pmd->root_lock); 1158 1159 return r; 1160} 1161 1162int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd, 1163 uint64_t current_id, 1164 uint64_t new_id) 1165{ 1166 int r = -EINVAL; 1167 1168 down_write(&pmd->root_lock); 1169 1170 if (pmd->fail_io) 1171 goto out; 1172 1173 if (pmd->trans_id != current_id) { 1174 DMERR("mismatched transaction id"); 1175 goto out; 1176 } 1177 1178 pmd->trans_id = new_id; 1179 r = 0; 1180 1181out: 1182 up_write(&pmd->root_lock); 1183 1184 return r; 1185} 1186 1187int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd, 1188 uint64_t *result) 1189{ 1190 int r = -EINVAL; 1191 1192 down_read(&pmd->root_lock); 1193 if (!pmd->fail_io) { 1194 *result = pmd->trans_id; 1195 r = 0; 1196 } 1197 up_read(&pmd->root_lock); 1198 1199 return r; 1200} 1201 1202static int __reserve_metadata_snap(struct dm_pool_metadata *pmd) 1203{ 1204 int r, inc; 1205 struct thin_disk_superblock *disk_super; 1206 struct dm_block *copy, *sblock; 1207 dm_block_t held_root; 1208 1209 /* 1210 * We commit to ensure the btree roots which we increment in a 1211 * moment are up to date. 1212 */ 1213 __commit_transaction(pmd); 1214 1215 /* 1216 * Copy the superblock. 1217 */ 1218 dm_sm_inc_block(pmd->metadata_sm, THIN_SUPERBLOCK_LOCATION); 1219 r = dm_tm_shadow_block(pmd->tm, THIN_SUPERBLOCK_LOCATION, 1220 &sb_validator, ©, &inc); 1221 if (r) 1222 return r; 1223 1224 BUG_ON(!inc); 1225 1226 held_root = dm_block_location(copy); 1227 disk_super = dm_block_data(copy); 1228 1229 if (le64_to_cpu(disk_super->held_root)) { 1230 DMWARN("Pool metadata snapshot already exists: release this before taking another."); 1231 1232 dm_tm_dec(pmd->tm, held_root); 1233 dm_tm_unlock(pmd->tm, copy); 1234 return -EBUSY; 1235 } 1236 1237 /* 1238 * Wipe the spacemap since we're not publishing this. 1239 */ 1240 memset(&disk_super->data_space_map_root, 0, 1241 sizeof(disk_super->data_space_map_root)); 1242 memset(&disk_super->metadata_space_map_root, 0, 1243 sizeof(disk_super->metadata_space_map_root)); 1244 1245 /* 1246 * Increment the data structures that need to be preserved. 1247 */ 1248 dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->data_mapping_root)); 1249 dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->device_details_root)); 1250 dm_tm_unlock(pmd->tm, copy); 1251 1252 /* 1253 * Write the held root into the superblock. 1254 */ 1255 r = superblock_lock(pmd, &sblock); 1256 if (r) { 1257 dm_tm_dec(pmd->tm, held_root); 1258 return r; 1259 } 1260 1261 disk_super = dm_block_data(sblock); 1262 disk_super->held_root = cpu_to_le64(held_root); 1263 dm_bm_unlock(sblock); 1264 return 0; 1265} 1266 1267int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd) 1268{ 1269 int r = -EINVAL; 1270 1271 down_write(&pmd->root_lock); 1272 if (!pmd->fail_io) 1273 r = __reserve_metadata_snap(pmd); 1274 up_write(&pmd->root_lock); 1275 1276 return r; 1277} 1278 1279static int __release_metadata_snap(struct dm_pool_metadata *pmd) 1280{ 1281 int r; 1282 struct thin_disk_superblock *disk_super; 1283 struct dm_block *sblock, *copy; 1284 dm_block_t held_root; 1285 1286 r = superblock_lock(pmd, &sblock); 1287 if (r) 1288 return r; 1289 1290 disk_super = dm_block_data(sblock); 1291 held_root = le64_to_cpu(disk_super->held_root); 1292 disk_super->held_root = cpu_to_le64(0); 1293 1294 dm_bm_unlock(sblock); 1295 1296 if (!held_root) { 1297 DMWARN("No pool metadata snapshot found: nothing to release."); 1298 return -EINVAL; 1299 } 1300 1301 r = dm_tm_read_lock(pmd->tm, held_root, &sb_validator, ©); 1302 if (r) 1303 return r; 1304 1305 disk_super = dm_block_data(copy); 1306 dm_btree_del(&pmd->info, le64_to_cpu(disk_super->data_mapping_root)); 1307 dm_btree_del(&pmd->details_info, le64_to_cpu(disk_super->device_details_root)); 1308 dm_sm_dec_block(pmd->metadata_sm, held_root); 1309 1310 dm_tm_unlock(pmd->tm, copy); 1311 1312 return 0; 1313} 1314 1315int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd) 1316{ 1317 int r = -EINVAL; 1318 1319 down_write(&pmd->root_lock); 1320 if (!pmd->fail_io) 1321 r = __release_metadata_snap(pmd); 1322 up_write(&pmd->root_lock); 1323 1324 return r; 1325} 1326 1327static int __get_metadata_snap(struct dm_pool_metadata *pmd, 1328 dm_block_t *result) 1329{ 1330 int r; 1331 struct thin_disk_superblock *disk_super; 1332 struct dm_block *sblock; 1333 1334 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION, 1335 &sb_validator, &sblock); 1336 if (r) 1337 return r; 1338 1339 disk_super = dm_block_data(sblock); 1340 *result = le64_to_cpu(disk_super->held_root); 1341 1342 dm_bm_unlock(sblock); 1343 1344 return 0; 1345} 1346 1347int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd, 1348 dm_block_t *result) 1349{ 1350 int r = -EINVAL; 1351 1352 down_read(&pmd->root_lock); 1353 if (!pmd->fail_io) 1354 r = __get_metadata_snap(pmd, result); 1355 up_read(&pmd->root_lock); 1356 1357 return r; 1358} 1359 1360int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev, 1361 struct dm_thin_device **td) 1362{ 1363 int r = -EINVAL; 1364 1365 down_write(&pmd->root_lock); 1366 if (!pmd->fail_io) 1367 r = __open_device(pmd, dev, 0, td); 1368 up_write(&pmd->root_lock); 1369 1370 return r; 1371} 1372 1373int dm_pool_close_thin_device(struct dm_thin_device *td) 1374{ 1375 down_write(&td->pmd->root_lock); 1376 __close_device(td); 1377 up_write(&td->pmd->root_lock); 1378 1379 return 0; 1380} 1381 1382dm_thin_id dm_thin_dev_id(struct dm_thin_device *td) 1383{ 1384 return td->id; 1385} 1386 1387/* 1388 * Check whether @time (of block creation) is older than @td's last snapshot. 1389 * If so then the associated block is shared with the last snapshot device. 1390 * Any block on a device created *after* the device last got snapshotted is 1391 * necessarily not shared. 1392 */ 1393static bool __snapshotted_since(struct dm_thin_device *td, uint32_t time) 1394{ 1395 return td->snapshotted_time > time; 1396} 1397 1398int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block, 1399 int can_issue_io, struct dm_thin_lookup_result *result) 1400{ 1401 int r; 1402 __le64 value; 1403 struct dm_pool_metadata *pmd = td->pmd; 1404 dm_block_t keys[2] = { td->id, block }; 1405 struct dm_btree_info *info; 1406 1407 down_read(&pmd->root_lock); 1408 if (pmd->fail_io) { 1409 up_read(&pmd->root_lock); 1410 return -EINVAL; 1411 } 1412 1413 if (can_issue_io) { 1414 info = &pmd->info; 1415 } else 1416 info = &pmd->nb_info; 1417 1418 r = dm_btree_lookup(info, pmd->root, keys, &value); 1419 if (!r) { 1420 uint64_t block_time = 0; 1421 dm_block_t exception_block; 1422 uint32_t exception_time; 1423 1424 block_time = le64_to_cpu(value); 1425 unpack_block_time(block_time, &exception_block, 1426 &exception_time); 1427 result->block = exception_block; 1428 result->shared = __snapshotted_since(td, exception_time); 1429 } 1430 1431 up_read(&pmd->root_lock); 1432 return r; 1433} 1434 1435/* FIXME: write a more efficient one in btree */ 1436int dm_thin_find_mapped_range(struct dm_thin_device *td, 1437 dm_block_t begin, dm_block_t end, 1438 dm_block_t *thin_begin, dm_block_t *thin_end, 1439 dm_block_t *pool_begin, bool *maybe_shared) 1440{ 1441 int r; 1442 dm_block_t pool_end; 1443 struct dm_thin_lookup_result lookup; 1444 1445 if (end < begin) 1446 return -ENODATA; 1447 1448 /* 1449 * Find first mapped block. 1450 */ 1451 while (begin < end) { 1452 r = dm_thin_find_block(td, begin, true, &lookup); 1453 if (r) { 1454 if (r != -ENODATA) 1455 return r; 1456 } else 1457 break; 1458 1459 begin++; 1460 } 1461 1462 if (begin == end) 1463 return -ENODATA; 1464 1465 *thin_begin = begin; 1466 *pool_begin = lookup.block; 1467 *maybe_shared = lookup.shared; 1468 1469 begin++; 1470 pool_end = *pool_begin + 1; 1471 while (begin != end) { 1472 r = dm_thin_find_block(td, begin, true, &lookup); 1473 if (r) { 1474 if (r == -ENODATA) 1475 break; 1476 else 1477 return r; 1478 } 1479 1480 if ((lookup.block != pool_end) || 1481 (lookup.shared != *maybe_shared)) 1482 break; 1483 1484 pool_end++; 1485 begin++; 1486 } 1487 1488 *thin_end = begin; 1489 return 0; 1490} 1491 1492static int __insert(struct dm_thin_device *td, dm_block_t block, 1493 dm_block_t data_block) 1494{ 1495 int r, inserted; 1496 __le64 value; 1497 struct dm_pool_metadata *pmd = td->pmd; 1498 dm_block_t keys[2] = { td->id, block }; 1499 1500 value = cpu_to_le64(pack_block_time(data_block, pmd->time)); 1501 __dm_bless_for_disk(&value); 1502 1503 r = dm_btree_insert_notify(&pmd->info, pmd->root, keys, &value, 1504 &pmd->root, &inserted); 1505 if (r) 1506 return r; 1507 1508 td->changed = 1; 1509 if (inserted) 1510 td->mapped_blocks++; 1511 1512 return 0; 1513} 1514 1515int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block, 1516 dm_block_t data_block) 1517{ 1518 int r = -EINVAL; 1519 1520 down_write(&td->pmd->root_lock); 1521 if (!td->pmd->fail_io) 1522 r = __insert(td, block, data_block); 1523 up_write(&td->pmd->root_lock); 1524 1525 return r; 1526} 1527 1528static int __remove(struct dm_thin_device *td, dm_block_t block) 1529{ 1530 int r; 1531 struct dm_pool_metadata *pmd = td->pmd; 1532 dm_block_t keys[2] = { td->id, block }; 1533 1534 r = dm_btree_remove(&pmd->info, pmd->root, keys, &pmd->root); 1535 if (r) 1536 return r; 1537 1538 td->mapped_blocks--; 1539 td->changed = 1; 1540 1541 return 0; 1542} 1543 1544static int __remove_range(struct dm_thin_device *td, dm_block_t begin, dm_block_t end) 1545{ 1546 int r; 1547 unsigned count, total_count = 0; 1548 struct dm_pool_metadata *pmd = td->pmd; 1549 dm_block_t keys[1] = { td->id }; 1550 __le64 value; 1551 dm_block_t mapping_root; 1552 1553 /* 1554 * Find the mapping tree 1555 */ 1556 r = dm_btree_lookup(&pmd->tl_info, pmd->root, keys, &value); 1557 if (r) 1558 return r; 1559 1560 /* 1561 * Remove from the mapping tree, taking care to inc the 1562 * ref count so it doesn't get deleted. 1563 */ 1564 mapping_root = le64_to_cpu(value); 1565 dm_tm_inc(pmd->tm, mapping_root); 1566 r = dm_btree_remove(&pmd->tl_info, pmd->root, keys, &pmd->root); 1567 if (r) 1568 return r; 1569 1570 /* 1571 * Remove leaves stops at the first unmapped entry, so we have to 1572 * loop round finding mapped ranges. 1573 */ 1574 while (begin < end) { 1575 r = dm_btree_lookup_next(&pmd->bl_info, mapping_root, &begin, &begin, &value); 1576 if (r == -ENODATA) 1577 break; 1578 1579 if (r) 1580 return r; 1581 1582 if (begin >= end) 1583 break; 1584 1585 r = dm_btree_remove_leaves(&pmd->bl_info, mapping_root, &begin, end, &mapping_root, &count); 1586 if (r) 1587 return r; 1588 1589 total_count += count; 1590 } 1591 1592 td->mapped_blocks -= total_count; 1593 td->changed = 1; 1594 1595 /* 1596 * Reinsert the mapping tree. 1597 */ 1598 value = cpu_to_le64(mapping_root); 1599 __dm_bless_for_disk(&value); 1600 return dm_btree_insert(&pmd->tl_info, pmd->root, keys, &value, &pmd->root); 1601} 1602 1603int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block) 1604{ 1605 int r = -EINVAL; 1606 1607 down_write(&td->pmd->root_lock); 1608 if (!td->pmd->fail_io) 1609 r = __remove(td, block); 1610 up_write(&td->pmd->root_lock); 1611 1612 return r; 1613} 1614 1615int dm_thin_remove_range(struct dm_thin_device *td, 1616 dm_block_t begin, dm_block_t end) 1617{ 1618 int r = -EINVAL; 1619 1620 down_write(&td->pmd->root_lock); 1621 if (!td->pmd->fail_io) 1622 r = __remove_range(td, begin, end); 1623 up_write(&td->pmd->root_lock); 1624 1625 return r; 1626} 1627 1628int dm_pool_block_is_used(struct dm_pool_metadata *pmd, dm_block_t b, bool *result) 1629{ 1630 int r; 1631 uint32_t ref_count; 1632 1633 down_read(&pmd->root_lock); 1634 r = dm_sm_get_count(pmd->data_sm, b, &ref_count); 1635 if (!r) 1636 *result = (ref_count != 0); 1637 up_read(&pmd->root_lock); 1638 1639 return r; 1640} 1641 1642bool dm_thin_changed_this_transaction(struct dm_thin_device *td) 1643{ 1644 int r; 1645 1646 down_read(&td->pmd->root_lock); 1647 r = td->changed; 1648 up_read(&td->pmd->root_lock); 1649 1650 return r; 1651} 1652 1653bool dm_pool_changed_this_transaction(struct dm_pool_metadata *pmd) 1654{ 1655 bool r = false; 1656 struct dm_thin_device *td, *tmp; 1657 1658 down_read(&pmd->root_lock); 1659 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) { 1660 if (td->changed) { 1661 r = td->changed; 1662 break; 1663 } 1664 } 1665 up_read(&pmd->root_lock); 1666 1667 return r; 1668} 1669 1670bool dm_thin_aborted_changes(struct dm_thin_device *td) 1671{ 1672 bool r; 1673 1674 down_read(&td->pmd->root_lock); 1675 r = td->aborted_with_changes; 1676 up_read(&td->pmd->root_lock); 1677 1678 return r; 1679} 1680 1681int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result) 1682{ 1683 int r = -EINVAL; 1684 1685 down_write(&pmd->root_lock); 1686 if (!pmd->fail_io) 1687 r = dm_sm_new_block(pmd->data_sm, result); 1688 up_write(&pmd->root_lock); 1689 1690 return r; 1691} 1692 1693int dm_pool_commit_metadata(struct dm_pool_metadata *pmd) 1694{ 1695 int r = -EINVAL; 1696 1697 down_write(&pmd->root_lock); 1698 if (pmd->fail_io) 1699 goto out; 1700 1701 r = __commit_transaction(pmd); 1702 if (r <= 0) 1703 goto out; 1704 1705 /* 1706 * Open the next transaction. 1707 */ 1708 r = __begin_transaction(pmd); 1709out: 1710 up_write(&pmd->root_lock); 1711 return r; 1712} 1713 1714static void __set_abort_with_changes_flags(struct dm_pool_metadata *pmd) 1715{ 1716 struct dm_thin_device *td; 1717 1718 list_for_each_entry(td, &pmd->thin_devices, list) 1719 td->aborted_with_changes = td->changed; 1720} 1721 1722int dm_pool_abort_metadata(struct dm_pool_metadata *pmd) 1723{ 1724 int r = -EINVAL; 1725 1726 down_write(&pmd->root_lock); 1727 if (pmd->fail_io) 1728 goto out; 1729 1730 __set_abort_with_changes_flags(pmd); 1731 __destroy_persistent_data_objects(pmd); 1732 r = __create_persistent_data_objects(pmd, false); 1733 if (r) 1734 pmd->fail_io = true; 1735 1736out: 1737 up_write(&pmd->root_lock); 1738 1739 return r; 1740} 1741 1742int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, dm_block_t *result) 1743{ 1744 int r = -EINVAL; 1745 1746 down_read(&pmd->root_lock); 1747 if (!pmd->fail_io) 1748 r = dm_sm_get_nr_free(pmd->data_sm, result); 1749 up_read(&pmd->root_lock); 1750 1751 return r; 1752} 1753 1754int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd, 1755 dm_block_t *result) 1756{ 1757 int r = -EINVAL; 1758 1759 down_read(&pmd->root_lock); 1760 if (!pmd->fail_io) 1761 r = dm_sm_get_nr_free(pmd->metadata_sm, result); 1762 up_read(&pmd->root_lock); 1763 1764 return r; 1765} 1766 1767int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd, 1768 dm_block_t *result) 1769{ 1770 int r = -EINVAL; 1771 1772 down_read(&pmd->root_lock); 1773 if (!pmd->fail_io) 1774 r = dm_sm_get_nr_blocks(pmd->metadata_sm, result); 1775 up_read(&pmd->root_lock); 1776 1777 return r; 1778} 1779 1780int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result) 1781{ 1782 int r = -EINVAL; 1783 1784 down_read(&pmd->root_lock); 1785 if (!pmd->fail_io) 1786 r = dm_sm_get_nr_blocks(pmd->data_sm, result); 1787 up_read(&pmd->root_lock); 1788 1789 return r; 1790} 1791 1792int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result) 1793{ 1794 int r = -EINVAL; 1795 struct dm_pool_metadata *pmd = td->pmd; 1796 1797 down_read(&pmd->root_lock); 1798 if (!pmd->fail_io) { 1799 *result = td->mapped_blocks; 1800 r = 0; 1801 } 1802 up_read(&pmd->root_lock); 1803 1804 return r; 1805} 1806 1807static int __highest_block(struct dm_thin_device *td, dm_block_t *result) 1808{ 1809 int r; 1810 __le64 value_le; 1811 dm_block_t thin_root; 1812 struct dm_pool_metadata *pmd = td->pmd; 1813 1814 r = dm_btree_lookup(&pmd->tl_info, pmd->root, &td->id, &value_le); 1815 if (r) 1816 return r; 1817 1818 thin_root = le64_to_cpu(value_le); 1819 1820 return dm_btree_find_highest_key(&pmd->bl_info, thin_root, result); 1821} 1822 1823int dm_thin_get_highest_mapped_block(struct dm_thin_device *td, 1824 dm_block_t *result) 1825{ 1826 int r = -EINVAL; 1827 struct dm_pool_metadata *pmd = td->pmd; 1828 1829 down_read(&pmd->root_lock); 1830 if (!pmd->fail_io) 1831 r = __highest_block(td, result); 1832 up_read(&pmd->root_lock); 1833 1834 return r; 1835} 1836 1837static int __resize_space_map(struct dm_space_map *sm, dm_block_t new_count) 1838{ 1839 int r; 1840 dm_block_t old_count; 1841 1842 r = dm_sm_get_nr_blocks(sm, &old_count); 1843 if (r) 1844 return r; 1845 1846 if (new_count == old_count) 1847 return 0; 1848 1849 if (new_count < old_count) { 1850 DMERR("cannot reduce size of space map"); 1851 return -EINVAL; 1852 } 1853 1854 return dm_sm_extend(sm, new_count - old_count); 1855} 1856 1857int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count) 1858{ 1859 int r = -EINVAL; 1860 1861 down_write(&pmd->root_lock); 1862 if (!pmd->fail_io) 1863 r = __resize_space_map(pmd->data_sm, new_count); 1864 up_write(&pmd->root_lock); 1865 1866 return r; 1867} 1868 1869int dm_pool_resize_metadata_dev(struct dm_pool_metadata *pmd, dm_block_t new_count) 1870{ 1871 int r = -EINVAL; 1872 1873 down_write(&pmd->root_lock); 1874 if (!pmd->fail_io) 1875 r = __resize_space_map(pmd->metadata_sm, new_count); 1876 up_write(&pmd->root_lock); 1877 1878 return r; 1879} 1880 1881void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd) 1882{ 1883 down_write(&pmd->root_lock); 1884 dm_bm_set_read_only(pmd->bm); 1885 up_write(&pmd->root_lock); 1886} 1887 1888void dm_pool_metadata_read_write(struct dm_pool_metadata *pmd) 1889{ 1890 down_write(&pmd->root_lock); 1891 dm_bm_set_read_write(pmd->bm); 1892 up_write(&pmd->root_lock); 1893} 1894 1895int dm_pool_register_metadata_threshold(struct dm_pool_metadata *pmd, 1896 dm_block_t threshold, 1897 dm_sm_threshold_fn fn, 1898 void *context) 1899{ 1900 int r; 1901 1902 down_write(&pmd->root_lock); 1903 r = dm_sm_register_threshold_callback(pmd->metadata_sm, threshold, fn, context); 1904 up_write(&pmd->root_lock); 1905 1906 return r; 1907} 1908 1909int dm_pool_metadata_set_needs_check(struct dm_pool_metadata *pmd) 1910{ 1911 int r; 1912 struct dm_block *sblock; 1913 struct thin_disk_superblock *disk_super; 1914 1915 down_write(&pmd->root_lock); 1916 pmd->flags |= THIN_METADATA_NEEDS_CHECK_FLAG; 1917 1918 r = superblock_lock(pmd, &sblock); 1919 if (r) { 1920 DMERR("couldn't read superblock"); 1921 goto out; 1922 } 1923 1924 disk_super = dm_block_data(sblock); 1925 disk_super->flags = cpu_to_le32(pmd->flags); 1926 1927 dm_bm_unlock(sblock); 1928out: 1929 up_write(&pmd->root_lock); 1930 return r; 1931} 1932 1933bool dm_pool_metadata_needs_check(struct dm_pool_metadata *pmd) 1934{ 1935 bool needs_check; 1936 1937 down_read(&pmd->root_lock); 1938 needs_check = pmd->flags & THIN_METADATA_NEEDS_CHECK_FLAG; 1939 up_read(&pmd->root_lock); 1940 1941 return needs_check; 1942} 1943 1944void dm_pool_issue_prefetches(struct dm_pool_metadata *pmd) 1945{ 1946 down_read(&pmd->root_lock); 1947 if (!pmd->fail_io) 1948 dm_tm_issue_prefetches(pmd->tm); 1949 up_read(&pmd->root_lock); 1950} 1951