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 SECTOR_TO_BLOCK_SHIFT 3 81 82 /* 83 * For btree insert: 84 * 3 for btree insert + 85 * 2 for btree lookup used within space map 86 * For btree remove: 87 * 2 for shadow spine + 88 * 4 for rebalance 3 child node 89 */ 90 #define THIN_MAX_CONCURRENT_LOCKS 6 91 92 /* This should be plenty */ 93 #define SPACE_MAP_ROOT_SIZE 128 94 95 /* 96 * Little endian on-disk superblock and device details. 97 */ 98 struct thin_disk_superblock { 99 __le32 csum; /* Checksum of superblock except for this field. */ 100 __le32 flags; 101 __le64 blocknr; /* This block number, dm_block_t. */ 102 103 __u8 uuid[16]; 104 __le64 magic; 105 __le32 version; 106 __le32 time; 107 108 __le64 trans_id; 109 110 /* 111 * Root held by userspace transactions. 112 */ 113 __le64 held_root; 114 115 __u8 data_space_map_root[SPACE_MAP_ROOT_SIZE]; 116 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE]; 117 118 /* 119 * 2-level btree mapping (dev_id, (dev block, time)) -> data block 120 */ 121 __le64 data_mapping_root; 122 123 /* 124 * Device detail root mapping dev_id -> device_details 125 */ 126 __le64 device_details_root; 127 128 __le32 data_block_size; /* In 512-byte sectors. */ 129 130 __le32 metadata_block_size; /* In 512-byte sectors. */ 131 __le64 metadata_nr_blocks; 132 133 __le32 compat_flags; 134 __le32 compat_ro_flags; 135 __le32 incompat_flags; 136 } __packed; 137 138 struct disk_device_details { 139 __le64 mapped_blocks; 140 __le64 transaction_id; /* When created. */ 141 __le32 creation_time; 142 __le32 snapshotted_time; 143 } __packed; 144 145 struct dm_pool_metadata { 146 struct hlist_node hash; 147 148 struct block_device *bdev; 149 struct dm_block_manager *bm; 150 struct dm_space_map *metadata_sm; 151 struct dm_space_map *data_sm; 152 struct dm_transaction_manager *tm; 153 struct dm_transaction_manager *nb_tm; 154 155 /* 156 * Two-level btree. 157 * First level holds thin_dev_t. 158 * Second level holds mappings. 159 */ 160 struct dm_btree_info info; 161 162 /* 163 * Non-blocking version of the above. 164 */ 165 struct dm_btree_info nb_info; 166 167 /* 168 * Just the top level for deleting whole devices. 169 */ 170 struct dm_btree_info tl_info; 171 172 /* 173 * Just the bottom level for creating new devices. 174 */ 175 struct dm_btree_info bl_info; 176 177 /* 178 * Describes the device details btree. 179 */ 180 struct dm_btree_info details_info; 181 182 struct rw_semaphore root_lock; 183 uint32_t time; 184 dm_block_t root; 185 dm_block_t details_root; 186 struct list_head thin_devices; 187 uint64_t trans_id; 188 unsigned long flags; 189 sector_t data_block_size; 190 191 /* 192 * Set if a transaction has to be aborted but the attempt to roll back 193 * to the previous (good) transaction failed. The only pool metadata 194 * operation possible in this state is the closing of the device. 195 */ 196 bool fail_io:1; 197 198 /* 199 * Reading the space map roots can fail, so we read it into these 200 * buffers before the superblock is locked and updated. 201 */ 202 __u8 data_space_map_root[SPACE_MAP_ROOT_SIZE]; 203 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE]; 204 }; 205 206 struct dm_thin_device { 207 struct list_head list; 208 struct dm_pool_metadata *pmd; 209 dm_thin_id id; 210 211 int open_count; 212 bool changed:1; 213 bool aborted_with_changes:1; 214 uint64_t mapped_blocks; 215 uint64_t transaction_id; 216 uint32_t creation_time; 217 uint32_t snapshotted_time; 218 }; 219 220 /*---------------------------------------------------------------- 221 * superblock validator 222 *--------------------------------------------------------------*/ 223 224 #define SUPERBLOCK_CSUM_XOR 160774 225 226 static void sb_prepare_for_write(struct dm_block_validator *v, 227 struct dm_block *b, 228 size_t block_size) 229 { 230 struct thin_disk_superblock *disk_super = dm_block_data(b); 231 232 disk_super->blocknr = cpu_to_le64(dm_block_location(b)); 233 disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags, 234 block_size - sizeof(__le32), 235 SUPERBLOCK_CSUM_XOR)); 236 } 237 238 static int sb_check(struct dm_block_validator *v, 239 struct dm_block *b, 240 size_t block_size) 241 { 242 struct thin_disk_superblock *disk_super = dm_block_data(b); 243 __le32 csum_le; 244 245 if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) { 246 DMERR("sb_check failed: blocknr %llu: " 247 "wanted %llu", le64_to_cpu(disk_super->blocknr), 248 (unsigned long long)dm_block_location(b)); 249 return -ENOTBLK; 250 } 251 252 if (le64_to_cpu(disk_super->magic) != THIN_SUPERBLOCK_MAGIC) { 253 DMERR("sb_check failed: magic %llu: " 254 "wanted %llu", le64_to_cpu(disk_super->magic), 255 (unsigned long long)THIN_SUPERBLOCK_MAGIC); 256 return -EILSEQ; 257 } 258 259 csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags, 260 block_size - sizeof(__le32), 261 SUPERBLOCK_CSUM_XOR)); 262 if (csum_le != disk_super->csum) { 263 DMERR("sb_check failed: csum %u: wanted %u", 264 le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum)); 265 return -EILSEQ; 266 } 267 268 return 0; 269 } 270 271 static struct dm_block_validator sb_validator = { 272 .name = "superblock", 273 .prepare_for_write = sb_prepare_for_write, 274 .check = sb_check 275 }; 276 277 /*---------------------------------------------------------------- 278 * Methods for the btree value types 279 *--------------------------------------------------------------*/ 280 281 static uint64_t pack_block_time(dm_block_t b, uint32_t t) 282 { 283 return (b << 24) | t; 284 } 285 286 static void unpack_block_time(uint64_t v, dm_block_t *b, uint32_t *t) 287 { 288 *b = v >> 24; 289 *t = v & ((1 << 24) - 1); 290 } 291 292 static void data_block_inc(void *context, const void *value_le) 293 { 294 struct dm_space_map *sm = context; 295 __le64 v_le; 296 uint64_t b; 297 uint32_t t; 298 299 memcpy(&v_le, value_le, sizeof(v_le)); 300 unpack_block_time(le64_to_cpu(v_le), &b, &t); 301 dm_sm_inc_block(sm, b); 302 } 303 304 static void data_block_dec(void *context, const void *value_le) 305 { 306 struct dm_space_map *sm = context; 307 __le64 v_le; 308 uint64_t b; 309 uint32_t t; 310 311 memcpy(&v_le, value_le, sizeof(v_le)); 312 unpack_block_time(le64_to_cpu(v_le), &b, &t); 313 dm_sm_dec_block(sm, b); 314 } 315 316 static int data_block_equal(void *context, const void *value1_le, const void *value2_le) 317 { 318 __le64 v1_le, v2_le; 319 uint64_t b1, b2; 320 uint32_t t; 321 322 memcpy(&v1_le, value1_le, sizeof(v1_le)); 323 memcpy(&v2_le, value2_le, sizeof(v2_le)); 324 unpack_block_time(le64_to_cpu(v1_le), &b1, &t); 325 unpack_block_time(le64_to_cpu(v2_le), &b2, &t); 326 327 return b1 == b2; 328 } 329 330 static void subtree_inc(void *context, const void *value) 331 { 332 struct dm_btree_info *info = context; 333 __le64 root_le; 334 uint64_t root; 335 336 memcpy(&root_le, value, sizeof(root_le)); 337 root = le64_to_cpu(root_le); 338 dm_tm_inc(info->tm, root); 339 } 340 341 static void subtree_dec(void *context, const void *value) 342 { 343 struct dm_btree_info *info = context; 344 __le64 root_le; 345 uint64_t root; 346 347 memcpy(&root_le, value, sizeof(root_le)); 348 root = le64_to_cpu(root_le); 349 if (dm_btree_del(info, root)) 350 DMERR("btree delete failed"); 351 } 352 353 static int subtree_equal(void *context, const void *value1_le, const void *value2_le) 354 { 355 __le64 v1_le, v2_le; 356 memcpy(&v1_le, value1_le, sizeof(v1_le)); 357 memcpy(&v2_le, value2_le, sizeof(v2_le)); 358 359 return v1_le == v2_le; 360 } 361 362 /*----------------------------------------------------------------*/ 363 364 static int superblock_lock_zero(struct dm_pool_metadata *pmd, 365 struct dm_block **sblock) 366 { 367 return dm_bm_write_lock_zero(pmd->bm, THIN_SUPERBLOCK_LOCATION, 368 &sb_validator, sblock); 369 } 370 371 static int superblock_lock(struct dm_pool_metadata *pmd, 372 struct dm_block **sblock) 373 { 374 return dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION, 375 &sb_validator, sblock); 376 } 377 378 static int __superblock_all_zeroes(struct dm_block_manager *bm, int *result) 379 { 380 int r; 381 unsigned i; 382 struct dm_block *b; 383 __le64 *data_le, zero = cpu_to_le64(0); 384 unsigned block_size = dm_bm_block_size(bm) / sizeof(__le64); 385 386 /* 387 * We can't use a validator here - it may be all zeroes. 388 */ 389 r = dm_bm_read_lock(bm, THIN_SUPERBLOCK_LOCATION, NULL, &b); 390 if (r) 391 return r; 392 393 data_le = dm_block_data(b); 394 *result = 1; 395 for (i = 0; i < block_size; i++) { 396 if (data_le[i] != zero) { 397 *result = 0; 398 break; 399 } 400 } 401 402 dm_bm_unlock(b); 403 404 return 0; 405 } 406 407 static void __setup_btree_details(struct dm_pool_metadata *pmd) 408 { 409 pmd->info.tm = pmd->tm; 410 pmd->info.levels = 2; 411 pmd->info.value_type.context = pmd->data_sm; 412 pmd->info.value_type.size = sizeof(__le64); 413 pmd->info.value_type.inc = data_block_inc; 414 pmd->info.value_type.dec = data_block_dec; 415 pmd->info.value_type.equal = data_block_equal; 416 417 memcpy(&pmd->nb_info, &pmd->info, sizeof(pmd->nb_info)); 418 pmd->nb_info.tm = pmd->nb_tm; 419 420 pmd->tl_info.tm = pmd->tm; 421 pmd->tl_info.levels = 1; 422 pmd->tl_info.value_type.context = &pmd->bl_info; 423 pmd->tl_info.value_type.size = sizeof(__le64); 424 pmd->tl_info.value_type.inc = subtree_inc; 425 pmd->tl_info.value_type.dec = subtree_dec; 426 pmd->tl_info.value_type.equal = subtree_equal; 427 428 pmd->bl_info.tm = pmd->tm; 429 pmd->bl_info.levels = 1; 430 pmd->bl_info.value_type.context = pmd->data_sm; 431 pmd->bl_info.value_type.size = sizeof(__le64); 432 pmd->bl_info.value_type.inc = data_block_inc; 433 pmd->bl_info.value_type.dec = data_block_dec; 434 pmd->bl_info.value_type.equal = data_block_equal; 435 436 pmd->details_info.tm = pmd->tm; 437 pmd->details_info.levels = 1; 438 pmd->details_info.value_type.context = NULL; 439 pmd->details_info.value_type.size = sizeof(struct disk_device_details); 440 pmd->details_info.value_type.inc = NULL; 441 pmd->details_info.value_type.dec = NULL; 442 pmd->details_info.value_type.equal = NULL; 443 } 444 445 static int save_sm_roots(struct dm_pool_metadata *pmd) 446 { 447 int r; 448 size_t len; 449 450 r = dm_sm_root_size(pmd->metadata_sm, &len); 451 if (r < 0) 452 return r; 453 454 r = dm_sm_copy_root(pmd->metadata_sm, &pmd->metadata_space_map_root, len); 455 if (r < 0) 456 return r; 457 458 r = dm_sm_root_size(pmd->data_sm, &len); 459 if (r < 0) 460 return r; 461 462 return dm_sm_copy_root(pmd->data_sm, &pmd->data_space_map_root, len); 463 } 464 465 static void copy_sm_roots(struct dm_pool_metadata *pmd, 466 struct thin_disk_superblock *disk) 467 { 468 memcpy(&disk->metadata_space_map_root, 469 &pmd->metadata_space_map_root, 470 sizeof(pmd->metadata_space_map_root)); 471 472 memcpy(&disk->data_space_map_root, 473 &pmd->data_space_map_root, 474 sizeof(pmd->data_space_map_root)); 475 } 476 477 static int __write_initial_superblock(struct dm_pool_metadata *pmd) 478 { 479 int r; 480 struct dm_block *sblock; 481 struct thin_disk_superblock *disk_super; 482 sector_t bdev_size = i_size_read(pmd->bdev->bd_inode) >> SECTOR_SHIFT; 483 484 if (bdev_size > THIN_METADATA_MAX_SECTORS) 485 bdev_size = THIN_METADATA_MAX_SECTORS; 486 487 r = dm_sm_commit(pmd->data_sm); 488 if (r < 0) 489 return r; 490 491 r = dm_tm_pre_commit(pmd->tm); 492 if (r < 0) 493 return r; 494 495 r = save_sm_roots(pmd); 496 if (r < 0) 497 return r; 498 499 r = superblock_lock_zero(pmd, &sblock); 500 if (r) 501 return r; 502 503 disk_super = dm_block_data(sblock); 504 disk_super->flags = 0; 505 memset(disk_super->uuid, 0, sizeof(disk_super->uuid)); 506 disk_super->magic = cpu_to_le64(THIN_SUPERBLOCK_MAGIC); 507 disk_super->version = cpu_to_le32(THIN_VERSION); 508 disk_super->time = 0; 509 disk_super->trans_id = 0; 510 disk_super->held_root = 0; 511 512 copy_sm_roots(pmd, disk_super); 513 514 disk_super->data_mapping_root = cpu_to_le64(pmd->root); 515 disk_super->device_details_root = cpu_to_le64(pmd->details_root); 516 disk_super->metadata_block_size = cpu_to_le32(THIN_METADATA_BLOCK_SIZE); 517 disk_super->metadata_nr_blocks = cpu_to_le64(bdev_size >> SECTOR_TO_BLOCK_SHIFT); 518 disk_super->data_block_size = cpu_to_le32(pmd->data_block_size); 519 520 return dm_tm_commit(pmd->tm, sblock); 521 } 522 523 static int __format_metadata(struct dm_pool_metadata *pmd) 524 { 525 int r; 526 527 r = dm_tm_create_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION, 528 &pmd->tm, &pmd->metadata_sm); 529 if (r < 0) { 530 DMERR("tm_create_with_sm failed"); 531 return r; 532 } 533 534 pmd->data_sm = dm_sm_disk_create(pmd->tm, 0); 535 if (IS_ERR(pmd->data_sm)) { 536 DMERR("sm_disk_create failed"); 537 r = PTR_ERR(pmd->data_sm); 538 goto bad_cleanup_tm; 539 } 540 541 pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm); 542 if (!pmd->nb_tm) { 543 DMERR("could not create non-blocking clone tm"); 544 r = -ENOMEM; 545 goto bad_cleanup_data_sm; 546 } 547 548 __setup_btree_details(pmd); 549 550 r = dm_btree_empty(&pmd->info, &pmd->root); 551 if (r < 0) 552 goto bad_cleanup_nb_tm; 553 554 r = dm_btree_empty(&pmd->details_info, &pmd->details_root); 555 if (r < 0) { 556 DMERR("couldn't create devices root"); 557 goto bad_cleanup_nb_tm; 558 } 559 560 r = __write_initial_superblock(pmd); 561 if (r) 562 goto bad_cleanup_nb_tm; 563 564 return 0; 565 566 bad_cleanup_nb_tm: 567 dm_tm_destroy(pmd->nb_tm); 568 bad_cleanup_data_sm: 569 dm_sm_destroy(pmd->data_sm); 570 bad_cleanup_tm: 571 dm_tm_destroy(pmd->tm); 572 dm_sm_destroy(pmd->metadata_sm); 573 574 return r; 575 } 576 577 static int __check_incompat_features(struct thin_disk_superblock *disk_super, 578 struct dm_pool_metadata *pmd) 579 { 580 uint32_t features; 581 582 features = le32_to_cpu(disk_super->incompat_flags) & ~THIN_FEATURE_INCOMPAT_SUPP; 583 if (features) { 584 DMERR("could not access metadata due to unsupported optional features (%lx).", 585 (unsigned long)features); 586 return -EINVAL; 587 } 588 589 /* 590 * Check for read-only metadata to skip the following RDWR checks. 591 */ 592 if (get_disk_ro(pmd->bdev->bd_disk)) 593 return 0; 594 595 features = le32_to_cpu(disk_super->compat_ro_flags) & ~THIN_FEATURE_COMPAT_RO_SUPP; 596 if (features) { 597 DMERR("could not access metadata RDWR due to unsupported optional features (%lx).", 598 (unsigned long)features); 599 return -EINVAL; 600 } 601 602 return 0; 603 } 604 605 static int __open_metadata(struct dm_pool_metadata *pmd) 606 { 607 int r; 608 struct dm_block *sblock; 609 struct thin_disk_superblock *disk_super; 610 611 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION, 612 &sb_validator, &sblock); 613 if (r < 0) { 614 DMERR("couldn't read superblock"); 615 return r; 616 } 617 618 disk_super = dm_block_data(sblock); 619 620 /* Verify the data block size hasn't changed */ 621 if (le32_to_cpu(disk_super->data_block_size) != pmd->data_block_size) { 622 DMERR("changing the data block size (from %u to %llu) is not supported", 623 le32_to_cpu(disk_super->data_block_size), 624 (unsigned long long)pmd->data_block_size); 625 r = -EINVAL; 626 goto bad_unlock_sblock; 627 } 628 629 r = __check_incompat_features(disk_super, pmd); 630 if (r < 0) 631 goto bad_unlock_sblock; 632 633 r = dm_tm_open_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION, 634 disk_super->metadata_space_map_root, 635 sizeof(disk_super->metadata_space_map_root), 636 &pmd->tm, &pmd->metadata_sm); 637 if (r < 0) { 638 DMERR("tm_open_with_sm failed"); 639 goto bad_unlock_sblock; 640 } 641 642 pmd->data_sm = dm_sm_disk_open(pmd->tm, disk_super->data_space_map_root, 643 sizeof(disk_super->data_space_map_root)); 644 if (IS_ERR(pmd->data_sm)) { 645 DMERR("sm_disk_open failed"); 646 r = PTR_ERR(pmd->data_sm); 647 goto bad_cleanup_tm; 648 } 649 650 pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm); 651 if (!pmd->nb_tm) { 652 DMERR("could not create non-blocking clone tm"); 653 r = -ENOMEM; 654 goto bad_cleanup_data_sm; 655 } 656 657 __setup_btree_details(pmd); 658 dm_bm_unlock(sblock); 659 660 return 0; 661 662 bad_cleanup_data_sm: 663 dm_sm_destroy(pmd->data_sm); 664 bad_cleanup_tm: 665 dm_tm_destroy(pmd->tm); 666 dm_sm_destroy(pmd->metadata_sm); 667 bad_unlock_sblock: 668 dm_bm_unlock(sblock); 669 670 return r; 671 } 672 673 static int __open_or_format_metadata(struct dm_pool_metadata *pmd, bool format_device) 674 { 675 int r, unformatted; 676 677 r = __superblock_all_zeroes(pmd->bm, &unformatted); 678 if (r) 679 return r; 680 681 if (unformatted) 682 return format_device ? __format_metadata(pmd) : -EPERM; 683 684 return __open_metadata(pmd); 685 } 686 687 static int __create_persistent_data_objects(struct dm_pool_metadata *pmd, bool format_device) 688 { 689 int r; 690 691 pmd->bm = dm_block_manager_create(pmd->bdev, THIN_METADATA_BLOCK_SIZE << SECTOR_SHIFT, 692 THIN_MAX_CONCURRENT_LOCKS); 693 if (IS_ERR(pmd->bm)) { 694 DMERR("could not create block manager"); 695 return PTR_ERR(pmd->bm); 696 } 697 698 r = __open_or_format_metadata(pmd, format_device); 699 if (r) 700 dm_block_manager_destroy(pmd->bm); 701 702 return r; 703 } 704 705 static void __destroy_persistent_data_objects(struct dm_pool_metadata *pmd) 706 { 707 dm_sm_destroy(pmd->data_sm); 708 dm_sm_destroy(pmd->metadata_sm); 709 dm_tm_destroy(pmd->nb_tm); 710 dm_tm_destroy(pmd->tm); 711 dm_block_manager_destroy(pmd->bm); 712 } 713 714 static int __begin_transaction(struct dm_pool_metadata *pmd) 715 { 716 int r; 717 struct thin_disk_superblock *disk_super; 718 struct dm_block *sblock; 719 720 /* 721 * We re-read the superblock every time. Shouldn't need to do this 722 * really. 723 */ 724 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION, 725 &sb_validator, &sblock); 726 if (r) 727 return r; 728 729 disk_super = dm_block_data(sblock); 730 pmd->time = le32_to_cpu(disk_super->time); 731 pmd->root = le64_to_cpu(disk_super->data_mapping_root); 732 pmd->details_root = le64_to_cpu(disk_super->device_details_root); 733 pmd->trans_id = le64_to_cpu(disk_super->trans_id); 734 pmd->flags = le32_to_cpu(disk_super->flags); 735 pmd->data_block_size = le32_to_cpu(disk_super->data_block_size); 736 737 dm_bm_unlock(sblock); 738 return 0; 739 } 740 741 static int __write_changed_details(struct dm_pool_metadata *pmd) 742 { 743 int r; 744 struct dm_thin_device *td, *tmp; 745 struct disk_device_details details; 746 uint64_t key; 747 748 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) { 749 if (!td->changed) 750 continue; 751 752 key = td->id; 753 754 details.mapped_blocks = cpu_to_le64(td->mapped_blocks); 755 details.transaction_id = cpu_to_le64(td->transaction_id); 756 details.creation_time = cpu_to_le32(td->creation_time); 757 details.snapshotted_time = cpu_to_le32(td->snapshotted_time); 758 __dm_bless_for_disk(&details); 759 760 r = dm_btree_insert(&pmd->details_info, pmd->details_root, 761 &key, &details, &pmd->details_root); 762 if (r) 763 return r; 764 765 if (td->open_count) 766 td->changed = 0; 767 else { 768 list_del(&td->list); 769 kfree(td); 770 } 771 } 772 773 return 0; 774 } 775 776 static int __commit_transaction(struct dm_pool_metadata *pmd) 777 { 778 int r; 779 struct thin_disk_superblock *disk_super; 780 struct dm_block *sblock; 781 782 /* 783 * We need to know if the thin_disk_superblock exceeds a 512-byte sector. 784 */ 785 BUILD_BUG_ON(sizeof(struct thin_disk_superblock) > 512); 786 787 r = __write_changed_details(pmd); 788 if (r < 0) 789 return r; 790 791 r = dm_sm_commit(pmd->data_sm); 792 if (r < 0) 793 return r; 794 795 r = dm_tm_pre_commit(pmd->tm); 796 if (r < 0) 797 return r; 798 799 r = save_sm_roots(pmd); 800 if (r < 0) 801 return r; 802 803 r = superblock_lock(pmd, &sblock); 804 if (r) 805 return r; 806 807 disk_super = dm_block_data(sblock); 808 disk_super->time = cpu_to_le32(pmd->time); 809 disk_super->data_mapping_root = cpu_to_le64(pmd->root); 810 disk_super->device_details_root = cpu_to_le64(pmd->details_root); 811 disk_super->trans_id = cpu_to_le64(pmd->trans_id); 812 disk_super->flags = cpu_to_le32(pmd->flags); 813 814 copy_sm_roots(pmd, disk_super); 815 816 return dm_tm_commit(pmd->tm, sblock); 817 } 818 819 struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev, 820 sector_t data_block_size, 821 bool format_device) 822 { 823 int r; 824 struct dm_pool_metadata *pmd; 825 826 pmd = kmalloc(sizeof(*pmd), GFP_KERNEL); 827 if (!pmd) { 828 DMERR("could not allocate metadata struct"); 829 return ERR_PTR(-ENOMEM); 830 } 831 832 init_rwsem(&pmd->root_lock); 833 pmd->time = 0; 834 INIT_LIST_HEAD(&pmd->thin_devices); 835 pmd->fail_io = false; 836 pmd->bdev = bdev; 837 pmd->data_block_size = data_block_size; 838 839 r = __create_persistent_data_objects(pmd, format_device); 840 if (r) { 841 kfree(pmd); 842 return ERR_PTR(r); 843 } 844 845 r = __begin_transaction(pmd); 846 if (r < 0) { 847 if (dm_pool_metadata_close(pmd) < 0) 848 DMWARN("%s: dm_pool_metadata_close() failed.", __func__); 849 return ERR_PTR(r); 850 } 851 852 return pmd; 853 } 854 855 int dm_pool_metadata_close(struct dm_pool_metadata *pmd) 856 { 857 int r; 858 unsigned open_devices = 0; 859 struct dm_thin_device *td, *tmp; 860 861 down_read(&pmd->root_lock); 862 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) { 863 if (td->open_count) 864 open_devices++; 865 else { 866 list_del(&td->list); 867 kfree(td); 868 } 869 } 870 up_read(&pmd->root_lock); 871 872 if (open_devices) { 873 DMERR("attempt to close pmd when %u device(s) are still open", 874 open_devices); 875 return -EBUSY; 876 } 877 878 if (!dm_bm_is_read_only(pmd->bm) && !pmd->fail_io) { 879 r = __commit_transaction(pmd); 880 if (r < 0) 881 DMWARN("%s: __commit_transaction() failed, error = %d", 882 __func__, r); 883 } 884 885 if (!pmd->fail_io) 886 __destroy_persistent_data_objects(pmd); 887 888 kfree(pmd); 889 return 0; 890 } 891 892 /* 893 * __open_device: Returns @td corresponding to device with id @dev, 894 * creating it if @create is set and incrementing @td->open_count. 895 * On failure, @td is undefined. 896 */ 897 static int __open_device(struct dm_pool_metadata *pmd, 898 dm_thin_id dev, int create, 899 struct dm_thin_device **td) 900 { 901 int r, changed = 0; 902 struct dm_thin_device *td2; 903 uint64_t key = dev; 904 struct disk_device_details details_le; 905 906 /* 907 * If the device is already open, return it. 908 */ 909 list_for_each_entry(td2, &pmd->thin_devices, list) 910 if (td2->id == dev) { 911 /* 912 * May not create an already-open device. 913 */ 914 if (create) 915 return -EEXIST; 916 917 td2->open_count++; 918 *td = td2; 919 return 0; 920 } 921 922 /* 923 * Check the device exists. 924 */ 925 r = dm_btree_lookup(&pmd->details_info, pmd->details_root, 926 &key, &details_le); 927 if (r) { 928 if (r != -ENODATA || !create) 929 return r; 930 931 /* 932 * Create new device. 933 */ 934 changed = 1; 935 details_le.mapped_blocks = 0; 936 details_le.transaction_id = cpu_to_le64(pmd->trans_id); 937 details_le.creation_time = cpu_to_le32(pmd->time); 938 details_le.snapshotted_time = cpu_to_le32(pmd->time); 939 } 940 941 *td = kmalloc(sizeof(**td), GFP_NOIO); 942 if (!*td) 943 return -ENOMEM; 944 945 (*td)->pmd = pmd; 946 (*td)->id = dev; 947 (*td)->open_count = 1; 948 (*td)->changed = changed; 949 (*td)->aborted_with_changes = false; 950 (*td)->mapped_blocks = le64_to_cpu(details_le.mapped_blocks); 951 (*td)->transaction_id = le64_to_cpu(details_le.transaction_id); 952 (*td)->creation_time = le32_to_cpu(details_le.creation_time); 953 (*td)->snapshotted_time = le32_to_cpu(details_le.snapshotted_time); 954 955 list_add(&(*td)->list, &pmd->thin_devices); 956 957 return 0; 958 } 959 960 static void __close_device(struct dm_thin_device *td) 961 { 962 --td->open_count; 963 } 964 965 static int __create_thin(struct dm_pool_metadata *pmd, 966 dm_thin_id dev) 967 { 968 int r; 969 dm_block_t dev_root; 970 uint64_t key = dev; 971 struct disk_device_details details_le; 972 struct dm_thin_device *td; 973 __le64 value; 974 975 r = dm_btree_lookup(&pmd->details_info, pmd->details_root, 976 &key, &details_le); 977 if (!r) 978 return -EEXIST; 979 980 /* 981 * Create an empty btree for the mappings. 982 */ 983 r = dm_btree_empty(&pmd->bl_info, &dev_root); 984 if (r) 985 return r; 986 987 /* 988 * Insert it into the main mapping tree. 989 */ 990 value = cpu_to_le64(dev_root); 991 __dm_bless_for_disk(&value); 992 r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root); 993 if (r) { 994 dm_btree_del(&pmd->bl_info, dev_root); 995 return r; 996 } 997 998 r = __open_device(pmd, dev, 1, &td); 999 if (r) { 1000 dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root); 1001 dm_btree_del(&pmd->bl_info, dev_root); 1002 return r; 1003 } 1004 __close_device(td); 1005 1006 return r; 1007 } 1008 1009 int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev) 1010 { 1011 int r = -EINVAL; 1012 1013 down_write(&pmd->root_lock); 1014 if (!pmd->fail_io) 1015 r = __create_thin(pmd, dev); 1016 up_write(&pmd->root_lock); 1017 1018 return r; 1019 } 1020 1021 static int __set_snapshot_details(struct dm_pool_metadata *pmd, 1022 struct dm_thin_device *snap, 1023 dm_thin_id origin, uint32_t time) 1024 { 1025 int r; 1026 struct dm_thin_device *td; 1027 1028 r = __open_device(pmd, origin, 0, &td); 1029 if (r) 1030 return r; 1031 1032 td->changed = 1; 1033 td->snapshotted_time = time; 1034 1035 snap->mapped_blocks = td->mapped_blocks; 1036 snap->snapshotted_time = time; 1037 __close_device(td); 1038 1039 return 0; 1040 } 1041 1042 static int __create_snap(struct dm_pool_metadata *pmd, 1043 dm_thin_id dev, dm_thin_id origin) 1044 { 1045 int r; 1046 dm_block_t origin_root; 1047 uint64_t key = origin, dev_key = dev; 1048 struct dm_thin_device *td; 1049 struct disk_device_details details_le; 1050 __le64 value; 1051 1052 /* check this device is unused */ 1053 r = dm_btree_lookup(&pmd->details_info, pmd->details_root, 1054 &dev_key, &details_le); 1055 if (!r) 1056 return -EEXIST; 1057 1058 /* find the mapping tree for the origin */ 1059 r = dm_btree_lookup(&pmd->tl_info, pmd->root, &key, &value); 1060 if (r) 1061 return r; 1062 origin_root = le64_to_cpu(value); 1063 1064 /* clone the origin, an inc will do */ 1065 dm_tm_inc(pmd->tm, origin_root); 1066 1067 /* insert into the main mapping tree */ 1068 value = cpu_to_le64(origin_root); 1069 __dm_bless_for_disk(&value); 1070 key = dev; 1071 r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root); 1072 if (r) { 1073 dm_tm_dec(pmd->tm, origin_root); 1074 return r; 1075 } 1076 1077 pmd->time++; 1078 1079 r = __open_device(pmd, dev, 1, &td); 1080 if (r) 1081 goto bad; 1082 1083 r = __set_snapshot_details(pmd, td, origin, pmd->time); 1084 __close_device(td); 1085 1086 if (r) 1087 goto bad; 1088 1089 return 0; 1090 1091 bad: 1092 dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root); 1093 dm_btree_remove(&pmd->details_info, pmd->details_root, 1094 &key, &pmd->details_root); 1095 return r; 1096 } 1097 1098 int dm_pool_create_snap(struct dm_pool_metadata *pmd, 1099 dm_thin_id dev, 1100 dm_thin_id origin) 1101 { 1102 int r = -EINVAL; 1103 1104 down_write(&pmd->root_lock); 1105 if (!pmd->fail_io) 1106 r = __create_snap(pmd, dev, origin); 1107 up_write(&pmd->root_lock); 1108 1109 return r; 1110 } 1111 1112 static int __delete_device(struct dm_pool_metadata *pmd, dm_thin_id dev) 1113 { 1114 int r; 1115 uint64_t key = dev; 1116 struct dm_thin_device *td; 1117 1118 /* TODO: failure should mark the transaction invalid */ 1119 r = __open_device(pmd, dev, 0, &td); 1120 if (r) 1121 return r; 1122 1123 if (td->open_count > 1) { 1124 __close_device(td); 1125 return -EBUSY; 1126 } 1127 1128 list_del(&td->list); 1129 kfree(td); 1130 r = dm_btree_remove(&pmd->details_info, pmd->details_root, 1131 &key, &pmd->details_root); 1132 if (r) 1133 return r; 1134 1135 r = dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root); 1136 if (r) 1137 return r; 1138 1139 return 0; 1140 } 1141 1142 int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd, 1143 dm_thin_id dev) 1144 { 1145 int r = -EINVAL; 1146 1147 down_write(&pmd->root_lock); 1148 if (!pmd->fail_io) 1149 r = __delete_device(pmd, dev); 1150 up_write(&pmd->root_lock); 1151 1152 return r; 1153 } 1154 1155 int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd, 1156 uint64_t current_id, 1157 uint64_t new_id) 1158 { 1159 int r = -EINVAL; 1160 1161 down_write(&pmd->root_lock); 1162 1163 if (pmd->fail_io) 1164 goto out; 1165 1166 if (pmd->trans_id != current_id) { 1167 DMERR("mismatched transaction id"); 1168 goto out; 1169 } 1170 1171 pmd->trans_id = new_id; 1172 r = 0; 1173 1174 out: 1175 up_write(&pmd->root_lock); 1176 1177 return r; 1178 } 1179 1180 int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd, 1181 uint64_t *result) 1182 { 1183 int r = -EINVAL; 1184 1185 down_read(&pmd->root_lock); 1186 if (!pmd->fail_io) { 1187 *result = pmd->trans_id; 1188 r = 0; 1189 } 1190 up_read(&pmd->root_lock); 1191 1192 return r; 1193 } 1194 1195 static int __reserve_metadata_snap(struct dm_pool_metadata *pmd) 1196 { 1197 int r, inc; 1198 struct thin_disk_superblock *disk_super; 1199 struct dm_block *copy, *sblock; 1200 dm_block_t held_root; 1201 1202 /* 1203 * We commit to ensure the btree roots which we increment in a 1204 * moment are up to date. 1205 */ 1206 __commit_transaction(pmd); 1207 1208 /* 1209 * Copy the superblock. 1210 */ 1211 dm_sm_inc_block(pmd->metadata_sm, THIN_SUPERBLOCK_LOCATION); 1212 r = dm_tm_shadow_block(pmd->tm, THIN_SUPERBLOCK_LOCATION, 1213 &sb_validator, ©, &inc); 1214 if (r) 1215 return r; 1216 1217 BUG_ON(!inc); 1218 1219 held_root = dm_block_location(copy); 1220 disk_super = dm_block_data(copy); 1221 1222 if (le64_to_cpu(disk_super->held_root)) { 1223 DMWARN("Pool metadata snapshot already exists: release this before taking another."); 1224 1225 dm_tm_dec(pmd->tm, held_root); 1226 dm_tm_unlock(pmd->tm, copy); 1227 return -EBUSY; 1228 } 1229 1230 /* 1231 * Wipe the spacemap since we're not publishing this. 1232 */ 1233 memset(&disk_super->data_space_map_root, 0, 1234 sizeof(disk_super->data_space_map_root)); 1235 memset(&disk_super->metadata_space_map_root, 0, 1236 sizeof(disk_super->metadata_space_map_root)); 1237 1238 /* 1239 * Increment the data structures that need to be preserved. 1240 */ 1241 dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->data_mapping_root)); 1242 dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->device_details_root)); 1243 dm_tm_unlock(pmd->tm, copy); 1244 1245 /* 1246 * Write the held root into the superblock. 1247 */ 1248 r = superblock_lock(pmd, &sblock); 1249 if (r) { 1250 dm_tm_dec(pmd->tm, held_root); 1251 return r; 1252 } 1253 1254 disk_super = dm_block_data(sblock); 1255 disk_super->held_root = cpu_to_le64(held_root); 1256 dm_bm_unlock(sblock); 1257 return 0; 1258 } 1259 1260 int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd) 1261 { 1262 int r = -EINVAL; 1263 1264 down_write(&pmd->root_lock); 1265 if (!pmd->fail_io) 1266 r = __reserve_metadata_snap(pmd); 1267 up_write(&pmd->root_lock); 1268 1269 return r; 1270 } 1271 1272 static int __release_metadata_snap(struct dm_pool_metadata *pmd) 1273 { 1274 int r; 1275 struct thin_disk_superblock *disk_super; 1276 struct dm_block *sblock, *copy; 1277 dm_block_t held_root; 1278 1279 r = superblock_lock(pmd, &sblock); 1280 if (r) 1281 return r; 1282 1283 disk_super = dm_block_data(sblock); 1284 held_root = le64_to_cpu(disk_super->held_root); 1285 disk_super->held_root = cpu_to_le64(0); 1286 1287 dm_bm_unlock(sblock); 1288 1289 if (!held_root) { 1290 DMWARN("No pool metadata snapshot found: nothing to release."); 1291 return -EINVAL; 1292 } 1293 1294 r = dm_tm_read_lock(pmd->tm, held_root, &sb_validator, ©); 1295 if (r) 1296 return r; 1297 1298 disk_super = dm_block_data(copy); 1299 dm_btree_del(&pmd->info, le64_to_cpu(disk_super->data_mapping_root)); 1300 dm_btree_del(&pmd->details_info, le64_to_cpu(disk_super->device_details_root)); 1301 dm_sm_dec_block(pmd->metadata_sm, held_root); 1302 1303 dm_tm_unlock(pmd->tm, copy); 1304 1305 return 0; 1306 } 1307 1308 int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd) 1309 { 1310 int r = -EINVAL; 1311 1312 down_write(&pmd->root_lock); 1313 if (!pmd->fail_io) 1314 r = __release_metadata_snap(pmd); 1315 up_write(&pmd->root_lock); 1316 1317 return r; 1318 } 1319 1320 static int __get_metadata_snap(struct dm_pool_metadata *pmd, 1321 dm_block_t *result) 1322 { 1323 int r; 1324 struct thin_disk_superblock *disk_super; 1325 struct dm_block *sblock; 1326 1327 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION, 1328 &sb_validator, &sblock); 1329 if (r) 1330 return r; 1331 1332 disk_super = dm_block_data(sblock); 1333 *result = le64_to_cpu(disk_super->held_root); 1334 1335 dm_bm_unlock(sblock); 1336 1337 return 0; 1338 } 1339 1340 int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd, 1341 dm_block_t *result) 1342 { 1343 int r = -EINVAL; 1344 1345 down_read(&pmd->root_lock); 1346 if (!pmd->fail_io) 1347 r = __get_metadata_snap(pmd, result); 1348 up_read(&pmd->root_lock); 1349 1350 return r; 1351 } 1352 1353 int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev, 1354 struct dm_thin_device **td) 1355 { 1356 int r = -EINVAL; 1357 1358 down_write(&pmd->root_lock); 1359 if (!pmd->fail_io) 1360 r = __open_device(pmd, dev, 0, td); 1361 up_write(&pmd->root_lock); 1362 1363 return r; 1364 } 1365 1366 int dm_pool_close_thin_device(struct dm_thin_device *td) 1367 { 1368 down_write(&td->pmd->root_lock); 1369 __close_device(td); 1370 up_write(&td->pmd->root_lock); 1371 1372 return 0; 1373 } 1374 1375 dm_thin_id dm_thin_dev_id(struct dm_thin_device *td) 1376 { 1377 return td->id; 1378 } 1379 1380 /* 1381 * Check whether @time (of block creation) is older than @td's last snapshot. 1382 * If so then the associated block is shared with the last snapshot device. 1383 * Any block on a device created *after* the device last got snapshotted is 1384 * necessarily not shared. 1385 */ 1386 static bool __snapshotted_since(struct dm_thin_device *td, uint32_t time) 1387 { 1388 return td->snapshotted_time > time; 1389 } 1390 1391 static void unpack_lookup_result(struct dm_thin_device *td, __le64 value, 1392 struct dm_thin_lookup_result *result) 1393 { 1394 uint64_t block_time = 0; 1395 dm_block_t exception_block; 1396 uint32_t exception_time; 1397 1398 block_time = le64_to_cpu(value); 1399 unpack_block_time(block_time, &exception_block, &exception_time); 1400 result->block = exception_block; 1401 result->shared = __snapshotted_since(td, exception_time); 1402 } 1403 1404 static int __find_block(struct dm_thin_device *td, dm_block_t block, 1405 int can_issue_io, struct dm_thin_lookup_result *result) 1406 { 1407 int r; 1408 __le64 value; 1409 struct dm_pool_metadata *pmd = td->pmd; 1410 dm_block_t keys[2] = { td->id, block }; 1411 struct dm_btree_info *info; 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 unpack_lookup_result(td, value, result); 1421 1422 return r; 1423 } 1424 1425 int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block, 1426 int can_issue_io, struct dm_thin_lookup_result *result) 1427 { 1428 int r; 1429 struct dm_pool_metadata *pmd = td->pmd; 1430 1431 down_read(&pmd->root_lock); 1432 if (pmd->fail_io) { 1433 up_read(&pmd->root_lock); 1434 return -EINVAL; 1435 } 1436 1437 r = __find_block(td, block, can_issue_io, result); 1438 1439 up_read(&pmd->root_lock); 1440 return r; 1441 } 1442 1443 static int __find_next_mapped_block(struct dm_thin_device *td, dm_block_t block, 1444 dm_block_t *vblock, 1445 struct dm_thin_lookup_result *result) 1446 { 1447 int r; 1448 __le64 value; 1449 struct dm_pool_metadata *pmd = td->pmd; 1450 dm_block_t keys[2] = { td->id, block }; 1451 1452 r = dm_btree_lookup_next(&pmd->info, pmd->root, keys, vblock, &value); 1453 if (!r) 1454 unpack_lookup_result(td, value, result); 1455 1456 return r; 1457 } 1458 1459 static int __find_mapped_range(struct dm_thin_device *td, 1460 dm_block_t begin, dm_block_t end, 1461 dm_block_t *thin_begin, dm_block_t *thin_end, 1462 dm_block_t *pool_begin, bool *maybe_shared) 1463 { 1464 int r; 1465 dm_block_t pool_end; 1466 struct dm_thin_lookup_result lookup; 1467 1468 if (end < begin) 1469 return -ENODATA; 1470 1471 r = __find_next_mapped_block(td, begin, &begin, &lookup); 1472 if (r) 1473 return r; 1474 1475 if (begin >= end) 1476 return -ENODATA; 1477 1478 *thin_begin = begin; 1479 *pool_begin = lookup.block; 1480 *maybe_shared = lookup.shared; 1481 1482 begin++; 1483 pool_end = *pool_begin + 1; 1484 while (begin != end) { 1485 r = __find_block(td, begin, true, &lookup); 1486 if (r) { 1487 if (r == -ENODATA) 1488 break; 1489 else 1490 return r; 1491 } 1492 1493 if ((lookup.block != pool_end) || 1494 (lookup.shared != *maybe_shared)) 1495 break; 1496 1497 pool_end++; 1498 begin++; 1499 } 1500 1501 *thin_end = begin; 1502 return 0; 1503 } 1504 1505 int dm_thin_find_mapped_range(struct dm_thin_device *td, 1506 dm_block_t begin, dm_block_t end, 1507 dm_block_t *thin_begin, dm_block_t *thin_end, 1508 dm_block_t *pool_begin, bool *maybe_shared) 1509 { 1510 int r = -EINVAL; 1511 struct dm_pool_metadata *pmd = td->pmd; 1512 1513 down_read(&pmd->root_lock); 1514 if (!pmd->fail_io) { 1515 r = __find_mapped_range(td, begin, end, thin_begin, thin_end, 1516 pool_begin, maybe_shared); 1517 } 1518 up_read(&pmd->root_lock); 1519 1520 return r; 1521 } 1522 1523 static int __insert(struct dm_thin_device *td, dm_block_t block, 1524 dm_block_t data_block) 1525 { 1526 int r, inserted; 1527 __le64 value; 1528 struct dm_pool_metadata *pmd = td->pmd; 1529 dm_block_t keys[2] = { td->id, block }; 1530 1531 value = cpu_to_le64(pack_block_time(data_block, pmd->time)); 1532 __dm_bless_for_disk(&value); 1533 1534 r = dm_btree_insert_notify(&pmd->info, pmd->root, keys, &value, 1535 &pmd->root, &inserted); 1536 if (r) 1537 return r; 1538 1539 td->changed = 1; 1540 if (inserted) 1541 td->mapped_blocks++; 1542 1543 return 0; 1544 } 1545 1546 int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block, 1547 dm_block_t data_block) 1548 { 1549 int r = -EINVAL; 1550 1551 down_write(&td->pmd->root_lock); 1552 if (!td->pmd->fail_io) 1553 r = __insert(td, block, data_block); 1554 up_write(&td->pmd->root_lock); 1555 1556 return r; 1557 } 1558 1559 static int __remove(struct dm_thin_device *td, dm_block_t block) 1560 { 1561 int r; 1562 struct dm_pool_metadata *pmd = td->pmd; 1563 dm_block_t keys[2] = { td->id, block }; 1564 1565 r = dm_btree_remove(&pmd->info, pmd->root, keys, &pmd->root); 1566 if (r) 1567 return r; 1568 1569 td->mapped_blocks--; 1570 td->changed = 1; 1571 1572 return 0; 1573 } 1574 1575 static int __remove_range(struct dm_thin_device *td, dm_block_t begin, dm_block_t end) 1576 { 1577 int r; 1578 unsigned count, total_count = 0; 1579 struct dm_pool_metadata *pmd = td->pmd; 1580 dm_block_t keys[1] = { td->id }; 1581 __le64 value; 1582 dm_block_t mapping_root; 1583 1584 /* 1585 * Find the mapping tree 1586 */ 1587 r = dm_btree_lookup(&pmd->tl_info, pmd->root, keys, &value); 1588 if (r) 1589 return r; 1590 1591 /* 1592 * Remove from the mapping tree, taking care to inc the 1593 * ref count so it doesn't get deleted. 1594 */ 1595 mapping_root = le64_to_cpu(value); 1596 dm_tm_inc(pmd->tm, mapping_root); 1597 r = dm_btree_remove(&pmd->tl_info, pmd->root, keys, &pmd->root); 1598 if (r) 1599 return r; 1600 1601 /* 1602 * Remove leaves stops at the first unmapped entry, so we have to 1603 * loop round finding mapped ranges. 1604 */ 1605 while (begin < end) { 1606 r = dm_btree_lookup_next(&pmd->bl_info, mapping_root, &begin, &begin, &value); 1607 if (r == -ENODATA) 1608 break; 1609 1610 if (r) 1611 return r; 1612 1613 if (begin >= end) 1614 break; 1615 1616 r = dm_btree_remove_leaves(&pmd->bl_info, mapping_root, &begin, end, &mapping_root, &count); 1617 if (r) 1618 return r; 1619 1620 total_count += count; 1621 } 1622 1623 td->mapped_blocks -= total_count; 1624 td->changed = 1; 1625 1626 /* 1627 * Reinsert the mapping tree. 1628 */ 1629 value = cpu_to_le64(mapping_root); 1630 __dm_bless_for_disk(&value); 1631 return dm_btree_insert(&pmd->tl_info, pmd->root, keys, &value, &pmd->root); 1632 } 1633 1634 int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block) 1635 { 1636 int r = -EINVAL; 1637 1638 down_write(&td->pmd->root_lock); 1639 if (!td->pmd->fail_io) 1640 r = __remove(td, block); 1641 up_write(&td->pmd->root_lock); 1642 1643 return r; 1644 } 1645 1646 int dm_thin_remove_range(struct dm_thin_device *td, 1647 dm_block_t begin, dm_block_t end) 1648 { 1649 int r = -EINVAL; 1650 1651 down_write(&td->pmd->root_lock); 1652 if (!td->pmd->fail_io) 1653 r = __remove_range(td, begin, end); 1654 up_write(&td->pmd->root_lock); 1655 1656 return r; 1657 } 1658 1659 int dm_pool_block_is_used(struct dm_pool_metadata *pmd, dm_block_t b, bool *result) 1660 { 1661 int r; 1662 uint32_t ref_count; 1663 1664 down_read(&pmd->root_lock); 1665 r = dm_sm_get_count(pmd->data_sm, b, &ref_count); 1666 if (!r) 1667 *result = (ref_count != 0); 1668 up_read(&pmd->root_lock); 1669 1670 return r; 1671 } 1672 1673 int dm_pool_inc_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e) 1674 { 1675 int r = 0; 1676 1677 down_write(&pmd->root_lock); 1678 for (; b != e; b++) { 1679 r = dm_sm_inc_block(pmd->data_sm, b); 1680 if (r) 1681 break; 1682 } 1683 up_write(&pmd->root_lock); 1684 1685 return r; 1686 } 1687 1688 int dm_pool_dec_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e) 1689 { 1690 int r = 0; 1691 1692 down_write(&pmd->root_lock); 1693 for (; b != e; b++) { 1694 r = dm_sm_dec_block(pmd->data_sm, b); 1695 if (r) 1696 break; 1697 } 1698 up_write(&pmd->root_lock); 1699 1700 return r; 1701 } 1702 1703 bool dm_thin_changed_this_transaction(struct dm_thin_device *td) 1704 { 1705 int r; 1706 1707 down_read(&td->pmd->root_lock); 1708 r = td->changed; 1709 up_read(&td->pmd->root_lock); 1710 1711 return r; 1712 } 1713 1714 bool dm_pool_changed_this_transaction(struct dm_pool_metadata *pmd) 1715 { 1716 bool r = false; 1717 struct dm_thin_device *td, *tmp; 1718 1719 down_read(&pmd->root_lock); 1720 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) { 1721 if (td->changed) { 1722 r = td->changed; 1723 break; 1724 } 1725 } 1726 up_read(&pmd->root_lock); 1727 1728 return r; 1729 } 1730 1731 bool dm_thin_aborted_changes(struct dm_thin_device *td) 1732 { 1733 bool r; 1734 1735 down_read(&td->pmd->root_lock); 1736 r = td->aborted_with_changes; 1737 up_read(&td->pmd->root_lock); 1738 1739 return r; 1740 } 1741 1742 int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result) 1743 { 1744 int r = -EINVAL; 1745 1746 down_write(&pmd->root_lock); 1747 if (!pmd->fail_io) 1748 r = dm_sm_new_block(pmd->data_sm, result); 1749 up_write(&pmd->root_lock); 1750 1751 return r; 1752 } 1753 1754 int dm_pool_commit_metadata(struct dm_pool_metadata *pmd) 1755 { 1756 int r = -EINVAL; 1757 1758 down_write(&pmd->root_lock); 1759 if (pmd->fail_io) 1760 goto out; 1761 1762 r = __commit_transaction(pmd); 1763 if (r <= 0) 1764 goto out; 1765 1766 /* 1767 * Open the next transaction. 1768 */ 1769 r = __begin_transaction(pmd); 1770 out: 1771 up_write(&pmd->root_lock); 1772 return r; 1773 } 1774 1775 static void __set_abort_with_changes_flags(struct dm_pool_metadata *pmd) 1776 { 1777 struct dm_thin_device *td; 1778 1779 list_for_each_entry(td, &pmd->thin_devices, list) 1780 td->aborted_with_changes = td->changed; 1781 } 1782 1783 int dm_pool_abort_metadata(struct dm_pool_metadata *pmd) 1784 { 1785 int r = -EINVAL; 1786 1787 down_write(&pmd->root_lock); 1788 if (pmd->fail_io) 1789 goto out; 1790 1791 __set_abort_with_changes_flags(pmd); 1792 __destroy_persistent_data_objects(pmd); 1793 r = __create_persistent_data_objects(pmd, false); 1794 if (r) 1795 pmd->fail_io = true; 1796 1797 out: 1798 up_write(&pmd->root_lock); 1799 1800 return r; 1801 } 1802 1803 int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, dm_block_t *result) 1804 { 1805 int r = -EINVAL; 1806 1807 down_read(&pmd->root_lock); 1808 if (!pmd->fail_io) 1809 r = dm_sm_get_nr_free(pmd->data_sm, result); 1810 up_read(&pmd->root_lock); 1811 1812 return r; 1813 } 1814 1815 int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd, 1816 dm_block_t *result) 1817 { 1818 int r = -EINVAL; 1819 1820 down_read(&pmd->root_lock); 1821 if (!pmd->fail_io) 1822 r = dm_sm_get_nr_free(pmd->metadata_sm, result); 1823 up_read(&pmd->root_lock); 1824 1825 return r; 1826 } 1827 1828 int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd, 1829 dm_block_t *result) 1830 { 1831 int r = -EINVAL; 1832 1833 down_read(&pmd->root_lock); 1834 if (!pmd->fail_io) 1835 r = dm_sm_get_nr_blocks(pmd->metadata_sm, result); 1836 up_read(&pmd->root_lock); 1837 1838 return r; 1839 } 1840 1841 int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result) 1842 { 1843 int r = -EINVAL; 1844 1845 down_read(&pmd->root_lock); 1846 if (!pmd->fail_io) 1847 r = dm_sm_get_nr_blocks(pmd->data_sm, result); 1848 up_read(&pmd->root_lock); 1849 1850 return r; 1851 } 1852 1853 int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result) 1854 { 1855 int r = -EINVAL; 1856 struct dm_pool_metadata *pmd = td->pmd; 1857 1858 down_read(&pmd->root_lock); 1859 if (!pmd->fail_io) { 1860 *result = td->mapped_blocks; 1861 r = 0; 1862 } 1863 up_read(&pmd->root_lock); 1864 1865 return r; 1866 } 1867 1868 static int __highest_block(struct dm_thin_device *td, dm_block_t *result) 1869 { 1870 int r; 1871 __le64 value_le; 1872 dm_block_t thin_root; 1873 struct dm_pool_metadata *pmd = td->pmd; 1874 1875 r = dm_btree_lookup(&pmd->tl_info, pmd->root, &td->id, &value_le); 1876 if (r) 1877 return r; 1878 1879 thin_root = le64_to_cpu(value_le); 1880 1881 return dm_btree_find_highest_key(&pmd->bl_info, thin_root, result); 1882 } 1883 1884 int dm_thin_get_highest_mapped_block(struct dm_thin_device *td, 1885 dm_block_t *result) 1886 { 1887 int r = -EINVAL; 1888 struct dm_pool_metadata *pmd = td->pmd; 1889 1890 down_read(&pmd->root_lock); 1891 if (!pmd->fail_io) 1892 r = __highest_block(td, result); 1893 up_read(&pmd->root_lock); 1894 1895 return r; 1896 } 1897 1898 static int __resize_space_map(struct dm_space_map *sm, dm_block_t new_count) 1899 { 1900 int r; 1901 dm_block_t old_count; 1902 1903 r = dm_sm_get_nr_blocks(sm, &old_count); 1904 if (r) 1905 return r; 1906 1907 if (new_count == old_count) 1908 return 0; 1909 1910 if (new_count < old_count) { 1911 DMERR("cannot reduce size of space map"); 1912 return -EINVAL; 1913 } 1914 1915 return dm_sm_extend(sm, new_count - old_count); 1916 } 1917 1918 int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count) 1919 { 1920 int r = -EINVAL; 1921 1922 down_write(&pmd->root_lock); 1923 if (!pmd->fail_io) 1924 r = __resize_space_map(pmd->data_sm, new_count); 1925 up_write(&pmd->root_lock); 1926 1927 return r; 1928 } 1929 1930 int dm_pool_resize_metadata_dev(struct dm_pool_metadata *pmd, dm_block_t new_count) 1931 { 1932 int r = -EINVAL; 1933 1934 down_write(&pmd->root_lock); 1935 if (!pmd->fail_io) 1936 r = __resize_space_map(pmd->metadata_sm, new_count); 1937 up_write(&pmd->root_lock); 1938 1939 return r; 1940 } 1941 1942 void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd) 1943 { 1944 down_write(&pmd->root_lock); 1945 dm_bm_set_read_only(pmd->bm); 1946 up_write(&pmd->root_lock); 1947 } 1948 1949 void dm_pool_metadata_read_write(struct dm_pool_metadata *pmd) 1950 { 1951 down_write(&pmd->root_lock); 1952 dm_bm_set_read_write(pmd->bm); 1953 up_write(&pmd->root_lock); 1954 } 1955 1956 int dm_pool_register_metadata_threshold(struct dm_pool_metadata *pmd, 1957 dm_block_t threshold, 1958 dm_sm_threshold_fn fn, 1959 void *context) 1960 { 1961 int r; 1962 1963 down_write(&pmd->root_lock); 1964 r = dm_sm_register_threshold_callback(pmd->metadata_sm, threshold, fn, context); 1965 up_write(&pmd->root_lock); 1966 1967 return r; 1968 } 1969 1970 int dm_pool_metadata_set_needs_check(struct dm_pool_metadata *pmd) 1971 { 1972 int r; 1973 struct dm_block *sblock; 1974 struct thin_disk_superblock *disk_super; 1975 1976 down_write(&pmd->root_lock); 1977 pmd->flags |= THIN_METADATA_NEEDS_CHECK_FLAG; 1978 1979 r = superblock_lock(pmd, &sblock); 1980 if (r) { 1981 DMERR("couldn't read superblock"); 1982 goto out; 1983 } 1984 1985 disk_super = dm_block_data(sblock); 1986 disk_super->flags = cpu_to_le32(pmd->flags); 1987 1988 dm_bm_unlock(sblock); 1989 out: 1990 up_write(&pmd->root_lock); 1991 return r; 1992 } 1993 1994 bool dm_pool_metadata_needs_check(struct dm_pool_metadata *pmd) 1995 { 1996 bool needs_check; 1997 1998 down_read(&pmd->root_lock); 1999 needs_check = pmd->flags & THIN_METADATA_NEEDS_CHECK_FLAG; 2000 up_read(&pmd->root_lock); 2001 2002 return needs_check; 2003 } 2004 2005 void dm_pool_issue_prefetches(struct dm_pool_metadata *pmd) 2006 { 2007 down_read(&pmd->root_lock); 2008 if (!pmd->fail_io) 2009 dm_tm_issue_prefetches(pmd->tm); 2010 up_read(&pmd->root_lock); 2011 } 2012