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 * We reserve a section of the metadata for commit overhead. 193 * All reported space does *not* include this. 194 */ 195 dm_block_t metadata_reserve; 196 197 /* 198 * Set if a transaction has to be aborted but the attempt to roll back 199 * to the previous (good) transaction failed. The only pool metadata 200 * operation possible in this state is the closing of the device. 201 */ 202 bool fail_io:1; 203 204 /* 205 * Reading the space map roots can fail, so we read it into these 206 * buffers before the superblock is locked and updated. 207 */ 208 __u8 data_space_map_root[SPACE_MAP_ROOT_SIZE]; 209 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE]; 210 }; 211 212 struct dm_thin_device { 213 struct list_head list; 214 struct dm_pool_metadata *pmd; 215 dm_thin_id id; 216 217 int open_count; 218 bool changed:1; 219 bool aborted_with_changes:1; 220 uint64_t mapped_blocks; 221 uint64_t transaction_id; 222 uint32_t creation_time; 223 uint32_t snapshotted_time; 224 }; 225 226 /*---------------------------------------------------------------- 227 * superblock validator 228 *--------------------------------------------------------------*/ 229 230 #define SUPERBLOCK_CSUM_XOR 160774 231 232 static void sb_prepare_for_write(struct dm_block_validator *v, 233 struct dm_block *b, 234 size_t block_size) 235 { 236 struct thin_disk_superblock *disk_super = dm_block_data(b); 237 238 disk_super->blocknr = cpu_to_le64(dm_block_location(b)); 239 disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags, 240 block_size - sizeof(__le32), 241 SUPERBLOCK_CSUM_XOR)); 242 } 243 244 static int sb_check(struct dm_block_validator *v, 245 struct dm_block *b, 246 size_t block_size) 247 { 248 struct thin_disk_superblock *disk_super = dm_block_data(b); 249 __le32 csum_le; 250 251 if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) { 252 DMERR("sb_check failed: blocknr %llu: " 253 "wanted %llu", le64_to_cpu(disk_super->blocknr), 254 (unsigned long long)dm_block_location(b)); 255 return -ENOTBLK; 256 } 257 258 if (le64_to_cpu(disk_super->magic) != THIN_SUPERBLOCK_MAGIC) { 259 DMERR("sb_check failed: magic %llu: " 260 "wanted %llu", le64_to_cpu(disk_super->magic), 261 (unsigned long long)THIN_SUPERBLOCK_MAGIC); 262 return -EILSEQ; 263 } 264 265 csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags, 266 block_size - sizeof(__le32), 267 SUPERBLOCK_CSUM_XOR)); 268 if (csum_le != disk_super->csum) { 269 DMERR("sb_check failed: csum %u: wanted %u", 270 le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum)); 271 return -EILSEQ; 272 } 273 274 return 0; 275 } 276 277 static struct dm_block_validator sb_validator = { 278 .name = "superblock", 279 .prepare_for_write = sb_prepare_for_write, 280 .check = sb_check 281 }; 282 283 /*---------------------------------------------------------------- 284 * Methods for the btree value types 285 *--------------------------------------------------------------*/ 286 287 static uint64_t pack_block_time(dm_block_t b, uint32_t t) 288 { 289 return (b << 24) | t; 290 } 291 292 static void unpack_block_time(uint64_t v, dm_block_t *b, uint32_t *t) 293 { 294 *b = v >> 24; 295 *t = v & ((1 << 24) - 1); 296 } 297 298 static void data_block_inc(void *context, const void *value_le) 299 { 300 struct dm_space_map *sm = context; 301 __le64 v_le; 302 uint64_t b; 303 uint32_t t; 304 305 memcpy(&v_le, value_le, sizeof(v_le)); 306 unpack_block_time(le64_to_cpu(v_le), &b, &t); 307 dm_sm_inc_block(sm, b); 308 } 309 310 static void data_block_dec(void *context, const void *value_le) 311 { 312 struct dm_space_map *sm = context; 313 __le64 v_le; 314 uint64_t b; 315 uint32_t t; 316 317 memcpy(&v_le, value_le, sizeof(v_le)); 318 unpack_block_time(le64_to_cpu(v_le), &b, &t); 319 dm_sm_dec_block(sm, b); 320 } 321 322 static int data_block_equal(void *context, const void *value1_le, const void *value2_le) 323 { 324 __le64 v1_le, v2_le; 325 uint64_t b1, b2; 326 uint32_t t; 327 328 memcpy(&v1_le, value1_le, sizeof(v1_le)); 329 memcpy(&v2_le, value2_le, sizeof(v2_le)); 330 unpack_block_time(le64_to_cpu(v1_le), &b1, &t); 331 unpack_block_time(le64_to_cpu(v2_le), &b2, &t); 332 333 return b1 == b2; 334 } 335 336 static void subtree_inc(void *context, const void *value) 337 { 338 struct dm_btree_info *info = context; 339 __le64 root_le; 340 uint64_t root; 341 342 memcpy(&root_le, value, sizeof(root_le)); 343 root = le64_to_cpu(root_le); 344 dm_tm_inc(info->tm, root); 345 } 346 347 static void subtree_dec(void *context, const void *value) 348 { 349 struct dm_btree_info *info = context; 350 __le64 root_le; 351 uint64_t root; 352 353 memcpy(&root_le, value, sizeof(root_le)); 354 root = le64_to_cpu(root_le); 355 if (dm_btree_del(info, root)) 356 DMERR("btree delete failed"); 357 } 358 359 static int subtree_equal(void *context, const void *value1_le, const void *value2_le) 360 { 361 __le64 v1_le, v2_le; 362 memcpy(&v1_le, value1_le, sizeof(v1_le)); 363 memcpy(&v2_le, value2_le, sizeof(v2_le)); 364 365 return v1_le == v2_le; 366 } 367 368 /*----------------------------------------------------------------*/ 369 370 static int superblock_lock_zero(struct dm_pool_metadata *pmd, 371 struct dm_block **sblock) 372 { 373 return dm_bm_write_lock_zero(pmd->bm, THIN_SUPERBLOCK_LOCATION, 374 &sb_validator, sblock); 375 } 376 377 static int superblock_lock(struct dm_pool_metadata *pmd, 378 struct dm_block **sblock) 379 { 380 return dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION, 381 &sb_validator, sblock); 382 } 383 384 static int __superblock_all_zeroes(struct dm_block_manager *bm, int *result) 385 { 386 int r; 387 unsigned i; 388 struct dm_block *b; 389 __le64 *data_le, zero = cpu_to_le64(0); 390 unsigned block_size = dm_bm_block_size(bm) / sizeof(__le64); 391 392 /* 393 * We can't use a validator here - it may be all zeroes. 394 */ 395 r = dm_bm_read_lock(bm, THIN_SUPERBLOCK_LOCATION, NULL, &b); 396 if (r) 397 return r; 398 399 data_le = dm_block_data(b); 400 *result = 1; 401 for (i = 0; i < block_size; i++) { 402 if (data_le[i] != zero) { 403 *result = 0; 404 break; 405 } 406 } 407 408 dm_bm_unlock(b); 409 410 return 0; 411 } 412 413 static void __setup_btree_details(struct dm_pool_metadata *pmd) 414 { 415 pmd->info.tm = pmd->tm; 416 pmd->info.levels = 2; 417 pmd->info.value_type.context = pmd->data_sm; 418 pmd->info.value_type.size = sizeof(__le64); 419 pmd->info.value_type.inc = data_block_inc; 420 pmd->info.value_type.dec = data_block_dec; 421 pmd->info.value_type.equal = data_block_equal; 422 423 memcpy(&pmd->nb_info, &pmd->info, sizeof(pmd->nb_info)); 424 pmd->nb_info.tm = pmd->nb_tm; 425 426 pmd->tl_info.tm = pmd->tm; 427 pmd->tl_info.levels = 1; 428 pmd->tl_info.value_type.context = &pmd->bl_info; 429 pmd->tl_info.value_type.size = sizeof(__le64); 430 pmd->tl_info.value_type.inc = subtree_inc; 431 pmd->tl_info.value_type.dec = subtree_dec; 432 pmd->tl_info.value_type.equal = subtree_equal; 433 434 pmd->bl_info.tm = pmd->tm; 435 pmd->bl_info.levels = 1; 436 pmd->bl_info.value_type.context = pmd->data_sm; 437 pmd->bl_info.value_type.size = sizeof(__le64); 438 pmd->bl_info.value_type.inc = data_block_inc; 439 pmd->bl_info.value_type.dec = data_block_dec; 440 pmd->bl_info.value_type.equal = data_block_equal; 441 442 pmd->details_info.tm = pmd->tm; 443 pmd->details_info.levels = 1; 444 pmd->details_info.value_type.context = NULL; 445 pmd->details_info.value_type.size = sizeof(struct disk_device_details); 446 pmd->details_info.value_type.inc = NULL; 447 pmd->details_info.value_type.dec = NULL; 448 pmd->details_info.value_type.equal = NULL; 449 } 450 451 static int save_sm_roots(struct dm_pool_metadata *pmd) 452 { 453 int r; 454 size_t len; 455 456 r = dm_sm_root_size(pmd->metadata_sm, &len); 457 if (r < 0) 458 return r; 459 460 r = dm_sm_copy_root(pmd->metadata_sm, &pmd->metadata_space_map_root, len); 461 if (r < 0) 462 return r; 463 464 r = dm_sm_root_size(pmd->data_sm, &len); 465 if (r < 0) 466 return r; 467 468 return dm_sm_copy_root(pmd->data_sm, &pmd->data_space_map_root, len); 469 } 470 471 static void copy_sm_roots(struct dm_pool_metadata *pmd, 472 struct thin_disk_superblock *disk) 473 { 474 memcpy(&disk->metadata_space_map_root, 475 &pmd->metadata_space_map_root, 476 sizeof(pmd->metadata_space_map_root)); 477 478 memcpy(&disk->data_space_map_root, 479 &pmd->data_space_map_root, 480 sizeof(pmd->data_space_map_root)); 481 } 482 483 static int __write_initial_superblock(struct dm_pool_metadata *pmd) 484 { 485 int r; 486 struct dm_block *sblock; 487 struct thin_disk_superblock *disk_super; 488 sector_t bdev_size = i_size_read(pmd->bdev->bd_inode) >> SECTOR_SHIFT; 489 490 if (bdev_size > THIN_METADATA_MAX_SECTORS) 491 bdev_size = THIN_METADATA_MAX_SECTORS; 492 493 r = dm_sm_commit(pmd->data_sm); 494 if (r < 0) 495 return r; 496 497 r = dm_tm_pre_commit(pmd->tm); 498 if (r < 0) 499 return r; 500 501 r = save_sm_roots(pmd); 502 if (r < 0) 503 return r; 504 505 r = superblock_lock_zero(pmd, &sblock); 506 if (r) 507 return r; 508 509 disk_super = dm_block_data(sblock); 510 disk_super->flags = 0; 511 memset(disk_super->uuid, 0, sizeof(disk_super->uuid)); 512 disk_super->magic = cpu_to_le64(THIN_SUPERBLOCK_MAGIC); 513 disk_super->version = cpu_to_le32(THIN_VERSION); 514 disk_super->time = 0; 515 disk_super->trans_id = 0; 516 disk_super->held_root = 0; 517 518 copy_sm_roots(pmd, disk_super); 519 520 disk_super->data_mapping_root = cpu_to_le64(pmd->root); 521 disk_super->device_details_root = cpu_to_le64(pmd->details_root); 522 disk_super->metadata_block_size = cpu_to_le32(THIN_METADATA_BLOCK_SIZE); 523 disk_super->metadata_nr_blocks = cpu_to_le64(bdev_size >> SECTOR_TO_BLOCK_SHIFT); 524 disk_super->data_block_size = cpu_to_le32(pmd->data_block_size); 525 526 return dm_tm_commit(pmd->tm, sblock); 527 } 528 529 static int __format_metadata(struct dm_pool_metadata *pmd) 530 { 531 int r; 532 533 r = dm_tm_create_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION, 534 &pmd->tm, &pmd->metadata_sm); 535 if (r < 0) { 536 DMERR("tm_create_with_sm failed"); 537 return r; 538 } 539 540 pmd->data_sm = dm_sm_disk_create(pmd->tm, 0); 541 if (IS_ERR(pmd->data_sm)) { 542 DMERR("sm_disk_create failed"); 543 r = PTR_ERR(pmd->data_sm); 544 goto bad_cleanup_tm; 545 } 546 547 pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm); 548 if (!pmd->nb_tm) { 549 DMERR("could not create non-blocking clone tm"); 550 r = -ENOMEM; 551 goto bad_cleanup_data_sm; 552 } 553 554 __setup_btree_details(pmd); 555 556 r = dm_btree_empty(&pmd->info, &pmd->root); 557 if (r < 0) 558 goto bad_cleanup_nb_tm; 559 560 r = dm_btree_empty(&pmd->details_info, &pmd->details_root); 561 if (r < 0) { 562 DMERR("couldn't create devices root"); 563 goto bad_cleanup_nb_tm; 564 } 565 566 r = __write_initial_superblock(pmd); 567 if (r) 568 goto bad_cleanup_nb_tm; 569 570 return 0; 571 572 bad_cleanup_nb_tm: 573 dm_tm_destroy(pmd->nb_tm); 574 bad_cleanup_data_sm: 575 dm_sm_destroy(pmd->data_sm); 576 bad_cleanup_tm: 577 dm_tm_destroy(pmd->tm); 578 dm_sm_destroy(pmd->metadata_sm); 579 580 return r; 581 } 582 583 static int __check_incompat_features(struct thin_disk_superblock *disk_super, 584 struct dm_pool_metadata *pmd) 585 { 586 uint32_t features; 587 588 features = le32_to_cpu(disk_super->incompat_flags) & ~THIN_FEATURE_INCOMPAT_SUPP; 589 if (features) { 590 DMERR("could not access metadata due to unsupported optional features (%lx).", 591 (unsigned long)features); 592 return -EINVAL; 593 } 594 595 /* 596 * Check for read-only metadata to skip the following RDWR checks. 597 */ 598 if (get_disk_ro(pmd->bdev->bd_disk)) 599 return 0; 600 601 features = le32_to_cpu(disk_super->compat_ro_flags) & ~THIN_FEATURE_COMPAT_RO_SUPP; 602 if (features) { 603 DMERR("could not access metadata RDWR due to unsupported optional features (%lx).", 604 (unsigned long)features); 605 return -EINVAL; 606 } 607 608 return 0; 609 } 610 611 static int __open_metadata(struct dm_pool_metadata *pmd) 612 { 613 int r; 614 struct dm_block *sblock; 615 struct thin_disk_superblock *disk_super; 616 617 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION, 618 &sb_validator, &sblock); 619 if (r < 0) { 620 DMERR("couldn't read superblock"); 621 return r; 622 } 623 624 disk_super = dm_block_data(sblock); 625 626 /* Verify the data block size hasn't changed */ 627 if (le32_to_cpu(disk_super->data_block_size) != pmd->data_block_size) { 628 DMERR("changing the data block size (from %u to %llu) is not supported", 629 le32_to_cpu(disk_super->data_block_size), 630 (unsigned long long)pmd->data_block_size); 631 r = -EINVAL; 632 goto bad_unlock_sblock; 633 } 634 635 r = __check_incompat_features(disk_super, pmd); 636 if (r < 0) 637 goto bad_unlock_sblock; 638 639 r = dm_tm_open_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION, 640 disk_super->metadata_space_map_root, 641 sizeof(disk_super->metadata_space_map_root), 642 &pmd->tm, &pmd->metadata_sm); 643 if (r < 0) { 644 DMERR("tm_open_with_sm failed"); 645 goto bad_unlock_sblock; 646 } 647 648 pmd->data_sm = dm_sm_disk_open(pmd->tm, disk_super->data_space_map_root, 649 sizeof(disk_super->data_space_map_root)); 650 if (IS_ERR(pmd->data_sm)) { 651 DMERR("sm_disk_open failed"); 652 r = PTR_ERR(pmd->data_sm); 653 goto bad_cleanup_tm; 654 } 655 656 pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm); 657 if (!pmd->nb_tm) { 658 DMERR("could not create non-blocking clone tm"); 659 r = -ENOMEM; 660 goto bad_cleanup_data_sm; 661 } 662 663 __setup_btree_details(pmd); 664 dm_bm_unlock(sblock); 665 666 return 0; 667 668 bad_cleanup_data_sm: 669 dm_sm_destroy(pmd->data_sm); 670 bad_cleanup_tm: 671 dm_tm_destroy(pmd->tm); 672 dm_sm_destroy(pmd->metadata_sm); 673 bad_unlock_sblock: 674 dm_bm_unlock(sblock); 675 676 return r; 677 } 678 679 static int __open_or_format_metadata(struct dm_pool_metadata *pmd, bool format_device) 680 { 681 int r, unformatted; 682 683 r = __superblock_all_zeroes(pmd->bm, &unformatted); 684 if (r) 685 return r; 686 687 if (unformatted) 688 return format_device ? __format_metadata(pmd) : -EPERM; 689 690 return __open_metadata(pmd); 691 } 692 693 static int __create_persistent_data_objects(struct dm_pool_metadata *pmd, bool format_device) 694 { 695 int r; 696 697 pmd->bm = dm_block_manager_create(pmd->bdev, THIN_METADATA_BLOCK_SIZE << SECTOR_SHIFT, 698 THIN_MAX_CONCURRENT_LOCKS); 699 if (IS_ERR(pmd->bm)) { 700 DMERR("could not create block manager"); 701 return PTR_ERR(pmd->bm); 702 } 703 704 r = __open_or_format_metadata(pmd, format_device); 705 if (r) 706 dm_block_manager_destroy(pmd->bm); 707 708 return r; 709 } 710 711 static void __destroy_persistent_data_objects(struct dm_pool_metadata *pmd) 712 { 713 dm_sm_destroy(pmd->data_sm); 714 dm_sm_destroy(pmd->metadata_sm); 715 dm_tm_destroy(pmd->nb_tm); 716 dm_tm_destroy(pmd->tm); 717 dm_block_manager_destroy(pmd->bm); 718 } 719 720 static int __begin_transaction(struct dm_pool_metadata *pmd) 721 { 722 int r; 723 struct thin_disk_superblock *disk_super; 724 struct dm_block *sblock; 725 726 /* 727 * We re-read the superblock every time. Shouldn't need to do this 728 * really. 729 */ 730 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION, 731 &sb_validator, &sblock); 732 if (r) 733 return r; 734 735 disk_super = dm_block_data(sblock); 736 pmd->time = le32_to_cpu(disk_super->time); 737 pmd->root = le64_to_cpu(disk_super->data_mapping_root); 738 pmd->details_root = le64_to_cpu(disk_super->device_details_root); 739 pmd->trans_id = le64_to_cpu(disk_super->trans_id); 740 pmd->flags = le32_to_cpu(disk_super->flags); 741 pmd->data_block_size = le32_to_cpu(disk_super->data_block_size); 742 743 dm_bm_unlock(sblock); 744 return 0; 745 } 746 747 static int __write_changed_details(struct dm_pool_metadata *pmd) 748 { 749 int r; 750 struct dm_thin_device *td, *tmp; 751 struct disk_device_details details; 752 uint64_t key; 753 754 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) { 755 if (!td->changed) 756 continue; 757 758 key = td->id; 759 760 details.mapped_blocks = cpu_to_le64(td->mapped_blocks); 761 details.transaction_id = cpu_to_le64(td->transaction_id); 762 details.creation_time = cpu_to_le32(td->creation_time); 763 details.snapshotted_time = cpu_to_le32(td->snapshotted_time); 764 __dm_bless_for_disk(&details); 765 766 r = dm_btree_insert(&pmd->details_info, pmd->details_root, 767 &key, &details, &pmd->details_root); 768 if (r) 769 return r; 770 771 if (td->open_count) 772 td->changed = 0; 773 else { 774 list_del(&td->list); 775 kfree(td); 776 } 777 } 778 779 return 0; 780 } 781 782 static int __commit_transaction(struct dm_pool_metadata *pmd) 783 { 784 int r; 785 struct thin_disk_superblock *disk_super; 786 struct dm_block *sblock; 787 788 /* 789 * We need to know if the thin_disk_superblock exceeds a 512-byte sector. 790 */ 791 BUILD_BUG_ON(sizeof(struct thin_disk_superblock) > 512); 792 793 r = __write_changed_details(pmd); 794 if (r < 0) 795 return r; 796 797 r = dm_sm_commit(pmd->data_sm); 798 if (r < 0) 799 return r; 800 801 r = dm_tm_pre_commit(pmd->tm); 802 if (r < 0) 803 return r; 804 805 r = save_sm_roots(pmd); 806 if (r < 0) 807 return r; 808 809 r = superblock_lock(pmd, &sblock); 810 if (r) 811 return r; 812 813 disk_super = dm_block_data(sblock); 814 disk_super->time = cpu_to_le32(pmd->time); 815 disk_super->data_mapping_root = cpu_to_le64(pmd->root); 816 disk_super->device_details_root = cpu_to_le64(pmd->details_root); 817 disk_super->trans_id = cpu_to_le64(pmd->trans_id); 818 disk_super->flags = cpu_to_le32(pmd->flags); 819 820 copy_sm_roots(pmd, disk_super); 821 822 return dm_tm_commit(pmd->tm, sblock); 823 } 824 825 static void __set_metadata_reserve(struct dm_pool_metadata *pmd) 826 { 827 int r; 828 dm_block_t total; 829 dm_block_t max_blocks = 4096; /* 16M */ 830 831 r = dm_sm_get_nr_blocks(pmd->metadata_sm, &total); 832 if (r) { 833 DMERR("could not get size of metadata device"); 834 pmd->metadata_reserve = max_blocks; 835 } else 836 pmd->metadata_reserve = min(max_blocks, div_u64(total, 10)); 837 } 838 839 struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev, 840 sector_t data_block_size, 841 bool format_device) 842 { 843 int r; 844 struct dm_pool_metadata *pmd; 845 846 pmd = kmalloc(sizeof(*pmd), GFP_KERNEL); 847 if (!pmd) { 848 DMERR("could not allocate metadata struct"); 849 return ERR_PTR(-ENOMEM); 850 } 851 852 init_rwsem(&pmd->root_lock); 853 pmd->time = 0; 854 INIT_LIST_HEAD(&pmd->thin_devices); 855 pmd->fail_io = false; 856 pmd->bdev = bdev; 857 pmd->data_block_size = data_block_size; 858 859 r = __create_persistent_data_objects(pmd, format_device); 860 if (r) { 861 kfree(pmd); 862 return ERR_PTR(r); 863 } 864 865 r = __begin_transaction(pmd); 866 if (r < 0) { 867 if (dm_pool_metadata_close(pmd) < 0) 868 DMWARN("%s: dm_pool_metadata_close() failed.", __func__); 869 return ERR_PTR(r); 870 } 871 872 __set_metadata_reserve(pmd); 873 874 return pmd; 875 } 876 877 int dm_pool_metadata_close(struct dm_pool_metadata *pmd) 878 { 879 int r; 880 unsigned open_devices = 0; 881 struct dm_thin_device *td, *tmp; 882 883 down_read(&pmd->root_lock); 884 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) { 885 if (td->open_count) 886 open_devices++; 887 else { 888 list_del(&td->list); 889 kfree(td); 890 } 891 } 892 up_read(&pmd->root_lock); 893 894 if (open_devices) { 895 DMERR("attempt to close pmd when %u device(s) are still open", 896 open_devices); 897 return -EBUSY; 898 } 899 900 if (!dm_bm_is_read_only(pmd->bm) && !pmd->fail_io) { 901 r = __commit_transaction(pmd); 902 if (r < 0) 903 DMWARN("%s: __commit_transaction() failed, error = %d", 904 __func__, r); 905 } 906 907 if (!pmd->fail_io) 908 __destroy_persistent_data_objects(pmd); 909 910 kfree(pmd); 911 return 0; 912 } 913 914 /* 915 * __open_device: Returns @td corresponding to device with id @dev, 916 * creating it if @create is set and incrementing @td->open_count. 917 * On failure, @td is undefined. 918 */ 919 static int __open_device(struct dm_pool_metadata *pmd, 920 dm_thin_id dev, int create, 921 struct dm_thin_device **td) 922 { 923 int r, changed = 0; 924 struct dm_thin_device *td2; 925 uint64_t key = dev; 926 struct disk_device_details details_le; 927 928 /* 929 * If the device is already open, return it. 930 */ 931 list_for_each_entry(td2, &pmd->thin_devices, list) 932 if (td2->id == dev) { 933 /* 934 * May not create an already-open device. 935 */ 936 if (create) 937 return -EEXIST; 938 939 td2->open_count++; 940 *td = td2; 941 return 0; 942 } 943 944 /* 945 * Check the device exists. 946 */ 947 r = dm_btree_lookup(&pmd->details_info, pmd->details_root, 948 &key, &details_le); 949 if (r) { 950 if (r != -ENODATA || !create) 951 return r; 952 953 /* 954 * Create new device. 955 */ 956 changed = 1; 957 details_le.mapped_blocks = 0; 958 details_le.transaction_id = cpu_to_le64(pmd->trans_id); 959 details_le.creation_time = cpu_to_le32(pmd->time); 960 details_le.snapshotted_time = cpu_to_le32(pmd->time); 961 } 962 963 *td = kmalloc(sizeof(**td), GFP_NOIO); 964 if (!*td) 965 return -ENOMEM; 966 967 (*td)->pmd = pmd; 968 (*td)->id = dev; 969 (*td)->open_count = 1; 970 (*td)->changed = changed; 971 (*td)->aborted_with_changes = false; 972 (*td)->mapped_blocks = le64_to_cpu(details_le.mapped_blocks); 973 (*td)->transaction_id = le64_to_cpu(details_le.transaction_id); 974 (*td)->creation_time = le32_to_cpu(details_le.creation_time); 975 (*td)->snapshotted_time = le32_to_cpu(details_le.snapshotted_time); 976 977 list_add(&(*td)->list, &pmd->thin_devices); 978 979 return 0; 980 } 981 982 static void __close_device(struct dm_thin_device *td) 983 { 984 --td->open_count; 985 } 986 987 static int __create_thin(struct dm_pool_metadata *pmd, 988 dm_thin_id dev) 989 { 990 int r; 991 dm_block_t dev_root; 992 uint64_t key = dev; 993 struct disk_device_details details_le; 994 struct dm_thin_device *td; 995 __le64 value; 996 997 r = dm_btree_lookup(&pmd->details_info, pmd->details_root, 998 &key, &details_le); 999 if (!r) 1000 return -EEXIST; 1001 1002 /* 1003 * Create an empty btree for the mappings. 1004 */ 1005 r = dm_btree_empty(&pmd->bl_info, &dev_root); 1006 if (r) 1007 return r; 1008 1009 /* 1010 * Insert it into the main mapping tree. 1011 */ 1012 value = cpu_to_le64(dev_root); 1013 __dm_bless_for_disk(&value); 1014 r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root); 1015 if (r) { 1016 dm_btree_del(&pmd->bl_info, dev_root); 1017 return r; 1018 } 1019 1020 r = __open_device(pmd, dev, 1, &td); 1021 if (r) { 1022 dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root); 1023 dm_btree_del(&pmd->bl_info, dev_root); 1024 return r; 1025 } 1026 __close_device(td); 1027 1028 return r; 1029 } 1030 1031 int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev) 1032 { 1033 int r = -EINVAL; 1034 1035 down_write(&pmd->root_lock); 1036 if (!pmd->fail_io) 1037 r = __create_thin(pmd, dev); 1038 up_write(&pmd->root_lock); 1039 1040 return r; 1041 } 1042 1043 static int __set_snapshot_details(struct dm_pool_metadata *pmd, 1044 struct dm_thin_device *snap, 1045 dm_thin_id origin, uint32_t time) 1046 { 1047 int r; 1048 struct dm_thin_device *td; 1049 1050 r = __open_device(pmd, origin, 0, &td); 1051 if (r) 1052 return r; 1053 1054 td->changed = 1; 1055 td->snapshotted_time = time; 1056 1057 snap->mapped_blocks = td->mapped_blocks; 1058 snap->snapshotted_time = time; 1059 __close_device(td); 1060 1061 return 0; 1062 } 1063 1064 static int __create_snap(struct dm_pool_metadata *pmd, 1065 dm_thin_id dev, dm_thin_id origin) 1066 { 1067 int r; 1068 dm_block_t origin_root; 1069 uint64_t key = origin, dev_key = dev; 1070 struct dm_thin_device *td; 1071 struct disk_device_details details_le; 1072 __le64 value; 1073 1074 /* check this device is unused */ 1075 r = dm_btree_lookup(&pmd->details_info, pmd->details_root, 1076 &dev_key, &details_le); 1077 if (!r) 1078 return -EEXIST; 1079 1080 /* find the mapping tree for the origin */ 1081 r = dm_btree_lookup(&pmd->tl_info, pmd->root, &key, &value); 1082 if (r) 1083 return r; 1084 origin_root = le64_to_cpu(value); 1085 1086 /* clone the origin, an inc will do */ 1087 dm_tm_inc(pmd->tm, origin_root); 1088 1089 /* insert into the main mapping tree */ 1090 value = cpu_to_le64(origin_root); 1091 __dm_bless_for_disk(&value); 1092 key = dev; 1093 r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root); 1094 if (r) { 1095 dm_tm_dec(pmd->tm, origin_root); 1096 return r; 1097 } 1098 1099 pmd->time++; 1100 1101 r = __open_device(pmd, dev, 1, &td); 1102 if (r) 1103 goto bad; 1104 1105 r = __set_snapshot_details(pmd, td, origin, pmd->time); 1106 __close_device(td); 1107 1108 if (r) 1109 goto bad; 1110 1111 return 0; 1112 1113 bad: 1114 dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root); 1115 dm_btree_remove(&pmd->details_info, pmd->details_root, 1116 &key, &pmd->details_root); 1117 return r; 1118 } 1119 1120 int dm_pool_create_snap(struct dm_pool_metadata *pmd, 1121 dm_thin_id dev, 1122 dm_thin_id origin) 1123 { 1124 int r = -EINVAL; 1125 1126 down_write(&pmd->root_lock); 1127 if (!pmd->fail_io) 1128 r = __create_snap(pmd, dev, origin); 1129 up_write(&pmd->root_lock); 1130 1131 return r; 1132 } 1133 1134 static int __delete_device(struct dm_pool_metadata *pmd, dm_thin_id dev) 1135 { 1136 int r; 1137 uint64_t key = dev; 1138 struct dm_thin_device *td; 1139 1140 /* TODO: failure should mark the transaction invalid */ 1141 r = __open_device(pmd, dev, 0, &td); 1142 if (r) 1143 return r; 1144 1145 if (td->open_count > 1) { 1146 __close_device(td); 1147 return -EBUSY; 1148 } 1149 1150 list_del(&td->list); 1151 kfree(td); 1152 r = dm_btree_remove(&pmd->details_info, pmd->details_root, 1153 &key, &pmd->details_root); 1154 if (r) 1155 return r; 1156 1157 r = dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root); 1158 if (r) 1159 return r; 1160 1161 return 0; 1162 } 1163 1164 int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd, 1165 dm_thin_id dev) 1166 { 1167 int r = -EINVAL; 1168 1169 down_write(&pmd->root_lock); 1170 if (!pmd->fail_io) 1171 r = __delete_device(pmd, dev); 1172 up_write(&pmd->root_lock); 1173 1174 return r; 1175 } 1176 1177 int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd, 1178 uint64_t current_id, 1179 uint64_t new_id) 1180 { 1181 int r = -EINVAL; 1182 1183 down_write(&pmd->root_lock); 1184 1185 if (pmd->fail_io) 1186 goto out; 1187 1188 if (pmd->trans_id != current_id) { 1189 DMERR("mismatched transaction id"); 1190 goto out; 1191 } 1192 1193 pmd->trans_id = new_id; 1194 r = 0; 1195 1196 out: 1197 up_write(&pmd->root_lock); 1198 1199 return r; 1200 } 1201 1202 int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd, 1203 uint64_t *result) 1204 { 1205 int r = -EINVAL; 1206 1207 down_read(&pmd->root_lock); 1208 if (!pmd->fail_io) { 1209 *result = pmd->trans_id; 1210 r = 0; 1211 } 1212 up_read(&pmd->root_lock); 1213 1214 return r; 1215 } 1216 1217 static int __reserve_metadata_snap(struct dm_pool_metadata *pmd) 1218 { 1219 int r, inc; 1220 struct thin_disk_superblock *disk_super; 1221 struct dm_block *copy, *sblock; 1222 dm_block_t held_root; 1223 1224 /* 1225 * We commit to ensure the btree roots which we increment in a 1226 * moment are up to date. 1227 */ 1228 __commit_transaction(pmd); 1229 1230 /* 1231 * Copy the superblock. 1232 */ 1233 dm_sm_inc_block(pmd->metadata_sm, THIN_SUPERBLOCK_LOCATION); 1234 r = dm_tm_shadow_block(pmd->tm, THIN_SUPERBLOCK_LOCATION, 1235 &sb_validator, ©, &inc); 1236 if (r) 1237 return r; 1238 1239 BUG_ON(!inc); 1240 1241 held_root = dm_block_location(copy); 1242 disk_super = dm_block_data(copy); 1243 1244 if (le64_to_cpu(disk_super->held_root)) { 1245 DMWARN("Pool metadata snapshot already exists: release this before taking another."); 1246 1247 dm_tm_dec(pmd->tm, held_root); 1248 dm_tm_unlock(pmd->tm, copy); 1249 return -EBUSY; 1250 } 1251 1252 /* 1253 * Wipe the spacemap since we're not publishing this. 1254 */ 1255 memset(&disk_super->data_space_map_root, 0, 1256 sizeof(disk_super->data_space_map_root)); 1257 memset(&disk_super->metadata_space_map_root, 0, 1258 sizeof(disk_super->metadata_space_map_root)); 1259 1260 /* 1261 * Increment the data structures that need to be preserved. 1262 */ 1263 dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->data_mapping_root)); 1264 dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->device_details_root)); 1265 dm_tm_unlock(pmd->tm, copy); 1266 1267 /* 1268 * Write the held root into the superblock. 1269 */ 1270 r = superblock_lock(pmd, &sblock); 1271 if (r) { 1272 dm_tm_dec(pmd->tm, held_root); 1273 return r; 1274 } 1275 1276 disk_super = dm_block_data(sblock); 1277 disk_super->held_root = cpu_to_le64(held_root); 1278 dm_bm_unlock(sblock); 1279 return 0; 1280 } 1281 1282 int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd) 1283 { 1284 int r = -EINVAL; 1285 1286 down_write(&pmd->root_lock); 1287 if (!pmd->fail_io) 1288 r = __reserve_metadata_snap(pmd); 1289 up_write(&pmd->root_lock); 1290 1291 return r; 1292 } 1293 1294 static int __release_metadata_snap(struct dm_pool_metadata *pmd) 1295 { 1296 int r; 1297 struct thin_disk_superblock *disk_super; 1298 struct dm_block *sblock, *copy; 1299 dm_block_t held_root; 1300 1301 r = superblock_lock(pmd, &sblock); 1302 if (r) 1303 return r; 1304 1305 disk_super = dm_block_data(sblock); 1306 held_root = le64_to_cpu(disk_super->held_root); 1307 disk_super->held_root = cpu_to_le64(0); 1308 1309 dm_bm_unlock(sblock); 1310 1311 if (!held_root) { 1312 DMWARN("No pool metadata snapshot found: nothing to release."); 1313 return -EINVAL; 1314 } 1315 1316 r = dm_tm_read_lock(pmd->tm, held_root, &sb_validator, ©); 1317 if (r) 1318 return r; 1319 1320 disk_super = dm_block_data(copy); 1321 dm_btree_del(&pmd->info, le64_to_cpu(disk_super->data_mapping_root)); 1322 dm_btree_del(&pmd->details_info, le64_to_cpu(disk_super->device_details_root)); 1323 dm_sm_dec_block(pmd->metadata_sm, held_root); 1324 1325 dm_tm_unlock(pmd->tm, copy); 1326 1327 return 0; 1328 } 1329 1330 int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd) 1331 { 1332 int r = -EINVAL; 1333 1334 down_write(&pmd->root_lock); 1335 if (!pmd->fail_io) 1336 r = __release_metadata_snap(pmd); 1337 up_write(&pmd->root_lock); 1338 1339 return r; 1340 } 1341 1342 static int __get_metadata_snap(struct dm_pool_metadata *pmd, 1343 dm_block_t *result) 1344 { 1345 int r; 1346 struct thin_disk_superblock *disk_super; 1347 struct dm_block *sblock; 1348 1349 r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION, 1350 &sb_validator, &sblock); 1351 if (r) 1352 return r; 1353 1354 disk_super = dm_block_data(sblock); 1355 *result = le64_to_cpu(disk_super->held_root); 1356 1357 dm_bm_unlock(sblock); 1358 1359 return 0; 1360 } 1361 1362 int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd, 1363 dm_block_t *result) 1364 { 1365 int r = -EINVAL; 1366 1367 down_read(&pmd->root_lock); 1368 if (!pmd->fail_io) 1369 r = __get_metadata_snap(pmd, result); 1370 up_read(&pmd->root_lock); 1371 1372 return r; 1373 } 1374 1375 int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev, 1376 struct dm_thin_device **td) 1377 { 1378 int r = -EINVAL; 1379 1380 down_write(&pmd->root_lock); 1381 if (!pmd->fail_io) 1382 r = __open_device(pmd, dev, 0, td); 1383 up_write(&pmd->root_lock); 1384 1385 return r; 1386 } 1387 1388 int dm_pool_close_thin_device(struct dm_thin_device *td) 1389 { 1390 down_write(&td->pmd->root_lock); 1391 __close_device(td); 1392 up_write(&td->pmd->root_lock); 1393 1394 return 0; 1395 } 1396 1397 dm_thin_id dm_thin_dev_id(struct dm_thin_device *td) 1398 { 1399 return td->id; 1400 } 1401 1402 /* 1403 * Check whether @time (of block creation) is older than @td's last snapshot. 1404 * If so then the associated block is shared with the last snapshot device. 1405 * Any block on a device created *after* the device last got snapshotted is 1406 * necessarily not shared. 1407 */ 1408 static bool __snapshotted_since(struct dm_thin_device *td, uint32_t time) 1409 { 1410 return td->snapshotted_time > time; 1411 } 1412 1413 static void unpack_lookup_result(struct dm_thin_device *td, __le64 value, 1414 struct dm_thin_lookup_result *result) 1415 { 1416 uint64_t block_time = 0; 1417 dm_block_t exception_block; 1418 uint32_t exception_time; 1419 1420 block_time = le64_to_cpu(value); 1421 unpack_block_time(block_time, &exception_block, &exception_time); 1422 result->block = exception_block; 1423 result->shared = __snapshotted_since(td, exception_time); 1424 } 1425 1426 static int __find_block(struct dm_thin_device *td, dm_block_t block, 1427 int can_issue_io, struct dm_thin_lookup_result *result) 1428 { 1429 int r; 1430 __le64 value; 1431 struct dm_pool_metadata *pmd = td->pmd; 1432 dm_block_t keys[2] = { td->id, block }; 1433 struct dm_btree_info *info; 1434 1435 if (can_issue_io) { 1436 info = &pmd->info; 1437 } else 1438 info = &pmd->nb_info; 1439 1440 r = dm_btree_lookup(info, pmd->root, keys, &value); 1441 if (!r) 1442 unpack_lookup_result(td, value, result); 1443 1444 return r; 1445 } 1446 1447 int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block, 1448 int can_issue_io, struct dm_thin_lookup_result *result) 1449 { 1450 int r; 1451 struct dm_pool_metadata *pmd = td->pmd; 1452 1453 down_read(&pmd->root_lock); 1454 if (pmd->fail_io) { 1455 up_read(&pmd->root_lock); 1456 return -EINVAL; 1457 } 1458 1459 r = __find_block(td, block, can_issue_io, result); 1460 1461 up_read(&pmd->root_lock); 1462 return r; 1463 } 1464 1465 static int __find_next_mapped_block(struct dm_thin_device *td, dm_block_t block, 1466 dm_block_t *vblock, 1467 struct dm_thin_lookup_result *result) 1468 { 1469 int r; 1470 __le64 value; 1471 struct dm_pool_metadata *pmd = td->pmd; 1472 dm_block_t keys[2] = { td->id, block }; 1473 1474 r = dm_btree_lookup_next(&pmd->info, pmd->root, keys, vblock, &value); 1475 if (!r) 1476 unpack_lookup_result(td, value, result); 1477 1478 return r; 1479 } 1480 1481 static int __find_mapped_range(struct dm_thin_device *td, 1482 dm_block_t begin, dm_block_t end, 1483 dm_block_t *thin_begin, dm_block_t *thin_end, 1484 dm_block_t *pool_begin, bool *maybe_shared) 1485 { 1486 int r; 1487 dm_block_t pool_end; 1488 struct dm_thin_lookup_result lookup; 1489 1490 if (end < begin) 1491 return -ENODATA; 1492 1493 r = __find_next_mapped_block(td, begin, &begin, &lookup); 1494 if (r) 1495 return r; 1496 1497 if (begin >= end) 1498 return -ENODATA; 1499 1500 *thin_begin = begin; 1501 *pool_begin = lookup.block; 1502 *maybe_shared = lookup.shared; 1503 1504 begin++; 1505 pool_end = *pool_begin + 1; 1506 while (begin != end) { 1507 r = __find_block(td, begin, true, &lookup); 1508 if (r) { 1509 if (r == -ENODATA) 1510 break; 1511 else 1512 return r; 1513 } 1514 1515 if ((lookup.block != pool_end) || 1516 (lookup.shared != *maybe_shared)) 1517 break; 1518 1519 pool_end++; 1520 begin++; 1521 } 1522 1523 *thin_end = begin; 1524 return 0; 1525 } 1526 1527 int dm_thin_find_mapped_range(struct dm_thin_device *td, 1528 dm_block_t begin, dm_block_t end, 1529 dm_block_t *thin_begin, dm_block_t *thin_end, 1530 dm_block_t *pool_begin, bool *maybe_shared) 1531 { 1532 int r = -EINVAL; 1533 struct dm_pool_metadata *pmd = td->pmd; 1534 1535 down_read(&pmd->root_lock); 1536 if (!pmd->fail_io) { 1537 r = __find_mapped_range(td, begin, end, thin_begin, thin_end, 1538 pool_begin, maybe_shared); 1539 } 1540 up_read(&pmd->root_lock); 1541 1542 return r; 1543 } 1544 1545 static int __insert(struct dm_thin_device *td, dm_block_t block, 1546 dm_block_t data_block) 1547 { 1548 int r, inserted; 1549 __le64 value; 1550 struct dm_pool_metadata *pmd = td->pmd; 1551 dm_block_t keys[2] = { td->id, block }; 1552 1553 value = cpu_to_le64(pack_block_time(data_block, pmd->time)); 1554 __dm_bless_for_disk(&value); 1555 1556 r = dm_btree_insert_notify(&pmd->info, pmd->root, keys, &value, 1557 &pmd->root, &inserted); 1558 if (r) 1559 return r; 1560 1561 td->changed = 1; 1562 if (inserted) 1563 td->mapped_blocks++; 1564 1565 return 0; 1566 } 1567 1568 int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block, 1569 dm_block_t data_block) 1570 { 1571 int r = -EINVAL; 1572 1573 down_write(&td->pmd->root_lock); 1574 if (!td->pmd->fail_io) 1575 r = __insert(td, block, data_block); 1576 up_write(&td->pmd->root_lock); 1577 1578 return r; 1579 } 1580 1581 static int __remove(struct dm_thin_device *td, dm_block_t block) 1582 { 1583 int r; 1584 struct dm_pool_metadata *pmd = td->pmd; 1585 dm_block_t keys[2] = { td->id, block }; 1586 1587 r = dm_btree_remove(&pmd->info, pmd->root, keys, &pmd->root); 1588 if (r) 1589 return r; 1590 1591 td->mapped_blocks--; 1592 td->changed = 1; 1593 1594 return 0; 1595 } 1596 1597 static int __remove_range(struct dm_thin_device *td, dm_block_t begin, dm_block_t end) 1598 { 1599 int r; 1600 unsigned count, total_count = 0; 1601 struct dm_pool_metadata *pmd = td->pmd; 1602 dm_block_t keys[1] = { td->id }; 1603 __le64 value; 1604 dm_block_t mapping_root; 1605 1606 /* 1607 * Find the mapping tree 1608 */ 1609 r = dm_btree_lookup(&pmd->tl_info, pmd->root, keys, &value); 1610 if (r) 1611 return r; 1612 1613 /* 1614 * Remove from the mapping tree, taking care to inc the 1615 * ref count so it doesn't get deleted. 1616 */ 1617 mapping_root = le64_to_cpu(value); 1618 dm_tm_inc(pmd->tm, mapping_root); 1619 r = dm_btree_remove(&pmd->tl_info, pmd->root, keys, &pmd->root); 1620 if (r) 1621 return r; 1622 1623 /* 1624 * Remove leaves stops at the first unmapped entry, so we have to 1625 * loop round finding mapped ranges. 1626 */ 1627 while (begin < end) { 1628 r = dm_btree_lookup_next(&pmd->bl_info, mapping_root, &begin, &begin, &value); 1629 if (r == -ENODATA) 1630 break; 1631 1632 if (r) 1633 return r; 1634 1635 if (begin >= end) 1636 break; 1637 1638 r = dm_btree_remove_leaves(&pmd->bl_info, mapping_root, &begin, end, &mapping_root, &count); 1639 if (r) 1640 return r; 1641 1642 total_count += count; 1643 } 1644 1645 td->mapped_blocks -= total_count; 1646 td->changed = 1; 1647 1648 /* 1649 * Reinsert the mapping tree. 1650 */ 1651 value = cpu_to_le64(mapping_root); 1652 __dm_bless_for_disk(&value); 1653 return dm_btree_insert(&pmd->tl_info, pmd->root, keys, &value, &pmd->root); 1654 } 1655 1656 int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block) 1657 { 1658 int r = -EINVAL; 1659 1660 down_write(&td->pmd->root_lock); 1661 if (!td->pmd->fail_io) 1662 r = __remove(td, block); 1663 up_write(&td->pmd->root_lock); 1664 1665 return r; 1666 } 1667 1668 int dm_thin_remove_range(struct dm_thin_device *td, 1669 dm_block_t begin, dm_block_t end) 1670 { 1671 int r = -EINVAL; 1672 1673 down_write(&td->pmd->root_lock); 1674 if (!td->pmd->fail_io) 1675 r = __remove_range(td, begin, end); 1676 up_write(&td->pmd->root_lock); 1677 1678 return r; 1679 } 1680 1681 int dm_pool_block_is_shared(struct dm_pool_metadata *pmd, dm_block_t b, bool *result) 1682 { 1683 int r; 1684 uint32_t ref_count; 1685 1686 down_read(&pmd->root_lock); 1687 r = dm_sm_get_count(pmd->data_sm, b, &ref_count); 1688 if (!r) 1689 *result = (ref_count > 1); 1690 up_read(&pmd->root_lock); 1691 1692 return r; 1693 } 1694 1695 int dm_pool_inc_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e) 1696 { 1697 int r = 0; 1698 1699 down_write(&pmd->root_lock); 1700 for (; b != e; b++) { 1701 r = dm_sm_inc_block(pmd->data_sm, b); 1702 if (r) 1703 break; 1704 } 1705 up_write(&pmd->root_lock); 1706 1707 return r; 1708 } 1709 1710 int dm_pool_dec_data_range(struct dm_pool_metadata *pmd, dm_block_t b, dm_block_t e) 1711 { 1712 int r = 0; 1713 1714 down_write(&pmd->root_lock); 1715 for (; b != e; b++) { 1716 r = dm_sm_dec_block(pmd->data_sm, b); 1717 if (r) 1718 break; 1719 } 1720 up_write(&pmd->root_lock); 1721 1722 return r; 1723 } 1724 1725 bool dm_thin_changed_this_transaction(struct dm_thin_device *td) 1726 { 1727 int r; 1728 1729 down_read(&td->pmd->root_lock); 1730 r = td->changed; 1731 up_read(&td->pmd->root_lock); 1732 1733 return r; 1734 } 1735 1736 bool dm_pool_changed_this_transaction(struct dm_pool_metadata *pmd) 1737 { 1738 bool r = false; 1739 struct dm_thin_device *td, *tmp; 1740 1741 down_read(&pmd->root_lock); 1742 list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) { 1743 if (td->changed) { 1744 r = td->changed; 1745 break; 1746 } 1747 } 1748 up_read(&pmd->root_lock); 1749 1750 return r; 1751 } 1752 1753 bool dm_thin_aborted_changes(struct dm_thin_device *td) 1754 { 1755 bool r; 1756 1757 down_read(&td->pmd->root_lock); 1758 r = td->aborted_with_changes; 1759 up_read(&td->pmd->root_lock); 1760 1761 return r; 1762 } 1763 1764 int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result) 1765 { 1766 int r = -EINVAL; 1767 1768 down_write(&pmd->root_lock); 1769 if (!pmd->fail_io) 1770 r = dm_sm_new_block(pmd->data_sm, result); 1771 up_write(&pmd->root_lock); 1772 1773 return r; 1774 } 1775 1776 int dm_pool_commit_metadata(struct dm_pool_metadata *pmd) 1777 { 1778 int r = -EINVAL; 1779 1780 down_write(&pmd->root_lock); 1781 if (pmd->fail_io) 1782 goto out; 1783 1784 r = __commit_transaction(pmd); 1785 if (r <= 0) 1786 goto out; 1787 1788 /* 1789 * Open the next transaction. 1790 */ 1791 r = __begin_transaction(pmd); 1792 out: 1793 up_write(&pmd->root_lock); 1794 return r; 1795 } 1796 1797 static void __set_abort_with_changes_flags(struct dm_pool_metadata *pmd) 1798 { 1799 struct dm_thin_device *td; 1800 1801 list_for_each_entry(td, &pmd->thin_devices, list) 1802 td->aborted_with_changes = td->changed; 1803 } 1804 1805 int dm_pool_abort_metadata(struct dm_pool_metadata *pmd) 1806 { 1807 int r = -EINVAL; 1808 1809 down_write(&pmd->root_lock); 1810 if (pmd->fail_io) 1811 goto out; 1812 1813 __set_abort_with_changes_flags(pmd); 1814 __destroy_persistent_data_objects(pmd); 1815 r = __create_persistent_data_objects(pmd, false); 1816 if (r) 1817 pmd->fail_io = true; 1818 1819 out: 1820 up_write(&pmd->root_lock); 1821 1822 return r; 1823 } 1824 1825 int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, dm_block_t *result) 1826 { 1827 int r = -EINVAL; 1828 1829 down_read(&pmd->root_lock); 1830 if (!pmd->fail_io) 1831 r = dm_sm_get_nr_free(pmd->data_sm, result); 1832 up_read(&pmd->root_lock); 1833 1834 return r; 1835 } 1836 1837 int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd, 1838 dm_block_t *result) 1839 { 1840 int r = -EINVAL; 1841 1842 down_read(&pmd->root_lock); 1843 if (!pmd->fail_io) 1844 r = dm_sm_get_nr_free(pmd->metadata_sm, result); 1845 1846 if (!r) { 1847 if (*result < pmd->metadata_reserve) 1848 *result = 0; 1849 else 1850 *result -= pmd->metadata_reserve; 1851 } 1852 up_read(&pmd->root_lock); 1853 1854 return r; 1855 } 1856 1857 int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd, 1858 dm_block_t *result) 1859 { 1860 int r = -EINVAL; 1861 1862 down_read(&pmd->root_lock); 1863 if (!pmd->fail_io) 1864 r = dm_sm_get_nr_blocks(pmd->metadata_sm, result); 1865 up_read(&pmd->root_lock); 1866 1867 return r; 1868 } 1869 1870 int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result) 1871 { 1872 int r = -EINVAL; 1873 1874 down_read(&pmd->root_lock); 1875 if (!pmd->fail_io) 1876 r = dm_sm_get_nr_blocks(pmd->data_sm, result); 1877 up_read(&pmd->root_lock); 1878 1879 return r; 1880 } 1881 1882 int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result) 1883 { 1884 int r = -EINVAL; 1885 struct dm_pool_metadata *pmd = td->pmd; 1886 1887 down_read(&pmd->root_lock); 1888 if (!pmd->fail_io) { 1889 *result = td->mapped_blocks; 1890 r = 0; 1891 } 1892 up_read(&pmd->root_lock); 1893 1894 return r; 1895 } 1896 1897 static int __highest_block(struct dm_thin_device *td, dm_block_t *result) 1898 { 1899 int r; 1900 __le64 value_le; 1901 dm_block_t thin_root; 1902 struct dm_pool_metadata *pmd = td->pmd; 1903 1904 r = dm_btree_lookup(&pmd->tl_info, pmd->root, &td->id, &value_le); 1905 if (r) 1906 return r; 1907 1908 thin_root = le64_to_cpu(value_le); 1909 1910 return dm_btree_find_highest_key(&pmd->bl_info, thin_root, result); 1911 } 1912 1913 int dm_thin_get_highest_mapped_block(struct dm_thin_device *td, 1914 dm_block_t *result) 1915 { 1916 int r = -EINVAL; 1917 struct dm_pool_metadata *pmd = td->pmd; 1918 1919 down_read(&pmd->root_lock); 1920 if (!pmd->fail_io) 1921 r = __highest_block(td, result); 1922 up_read(&pmd->root_lock); 1923 1924 return r; 1925 } 1926 1927 static int __resize_space_map(struct dm_space_map *sm, dm_block_t new_count) 1928 { 1929 int r; 1930 dm_block_t old_count; 1931 1932 r = dm_sm_get_nr_blocks(sm, &old_count); 1933 if (r) 1934 return r; 1935 1936 if (new_count == old_count) 1937 return 0; 1938 1939 if (new_count < old_count) { 1940 DMERR("cannot reduce size of space map"); 1941 return -EINVAL; 1942 } 1943 1944 return dm_sm_extend(sm, new_count - old_count); 1945 } 1946 1947 int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count) 1948 { 1949 int r = -EINVAL; 1950 1951 down_write(&pmd->root_lock); 1952 if (!pmd->fail_io) 1953 r = __resize_space_map(pmd->data_sm, new_count); 1954 up_write(&pmd->root_lock); 1955 1956 return r; 1957 } 1958 1959 int dm_pool_resize_metadata_dev(struct dm_pool_metadata *pmd, dm_block_t new_count) 1960 { 1961 int r = -EINVAL; 1962 1963 down_write(&pmd->root_lock); 1964 if (!pmd->fail_io) { 1965 r = __resize_space_map(pmd->metadata_sm, new_count); 1966 if (!r) 1967 __set_metadata_reserve(pmd); 1968 } 1969 up_write(&pmd->root_lock); 1970 1971 return r; 1972 } 1973 1974 void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd) 1975 { 1976 down_write(&pmd->root_lock); 1977 dm_bm_set_read_only(pmd->bm); 1978 up_write(&pmd->root_lock); 1979 } 1980 1981 void dm_pool_metadata_read_write(struct dm_pool_metadata *pmd) 1982 { 1983 down_write(&pmd->root_lock); 1984 dm_bm_set_read_write(pmd->bm); 1985 up_write(&pmd->root_lock); 1986 } 1987 1988 int dm_pool_register_metadata_threshold(struct dm_pool_metadata *pmd, 1989 dm_block_t threshold, 1990 dm_sm_threshold_fn fn, 1991 void *context) 1992 { 1993 int r; 1994 1995 down_write(&pmd->root_lock); 1996 r = dm_sm_register_threshold_callback(pmd->metadata_sm, threshold, fn, context); 1997 up_write(&pmd->root_lock); 1998 1999 return r; 2000 } 2001 2002 int dm_pool_metadata_set_needs_check(struct dm_pool_metadata *pmd) 2003 { 2004 int r; 2005 struct dm_block *sblock; 2006 struct thin_disk_superblock *disk_super; 2007 2008 down_write(&pmd->root_lock); 2009 pmd->flags |= THIN_METADATA_NEEDS_CHECK_FLAG; 2010 2011 r = superblock_lock(pmd, &sblock); 2012 if (r) { 2013 DMERR("couldn't read superblock"); 2014 goto out; 2015 } 2016 2017 disk_super = dm_block_data(sblock); 2018 disk_super->flags = cpu_to_le32(pmd->flags); 2019 2020 dm_bm_unlock(sblock); 2021 out: 2022 up_write(&pmd->root_lock); 2023 return r; 2024 } 2025 2026 bool dm_pool_metadata_needs_check(struct dm_pool_metadata *pmd) 2027 { 2028 bool needs_check; 2029 2030 down_read(&pmd->root_lock); 2031 needs_check = pmd->flags & THIN_METADATA_NEEDS_CHECK_FLAG; 2032 up_read(&pmd->root_lock); 2033 2034 return needs_check; 2035 } 2036 2037 void dm_pool_issue_prefetches(struct dm_pool_metadata *pmd) 2038 { 2039 down_read(&pmd->root_lock); 2040 if (!pmd->fail_io) 2041 dm_tm_issue_prefetches(pmd->tm); 2042 up_read(&pmd->root_lock); 2043 } 2044