1 // SPDX-License-Identifier: GPL-2.0-only 2 #include "dm.h" 3 #include "persistent-data/dm-transaction-manager.h" 4 #include "persistent-data/dm-bitset.h" 5 #include "persistent-data/dm-space-map.h" 6 7 #include <linux/dm-io.h> 8 #include <linux/dm-kcopyd.h> 9 #include <linux/init.h> 10 #include <linux/mempool.h> 11 #include <linux/module.h> 12 #include <linux/slab.h> 13 #include <linux/vmalloc.h> 14 15 #define DM_MSG_PREFIX "era" 16 17 #define SUPERBLOCK_LOCATION 0 18 #define SUPERBLOCK_MAGIC 2126579579 19 #define SUPERBLOCK_CSUM_XOR 146538381 20 #define MIN_ERA_VERSION 1 21 #define MAX_ERA_VERSION 1 22 #define INVALID_WRITESET_ROOT SUPERBLOCK_LOCATION 23 #define MIN_BLOCK_SIZE 8 24 25 /* 26 *-------------------------------------------------------------- 27 * Writeset 28 *-------------------------------------------------------------- 29 */ 30 struct writeset_metadata { 31 uint32_t nr_bits; 32 dm_block_t root; 33 }; 34 35 struct writeset { 36 struct writeset_metadata md; 37 38 /* 39 * An in core copy of the bits to save constantly doing look ups on 40 * disk. 41 */ 42 unsigned long *bits; 43 }; 44 45 /* 46 * This does not free off the on disk bitset as this will normally be done 47 * after digesting into the era array. 48 */ 49 static void writeset_free(struct writeset *ws) 50 { 51 vfree(ws->bits); 52 ws->bits = NULL; 53 } 54 55 static int setup_on_disk_bitset(struct dm_disk_bitset *info, 56 unsigned int nr_bits, dm_block_t *root) 57 { 58 int r; 59 60 r = dm_bitset_empty(info, root); 61 if (r) 62 return r; 63 64 return dm_bitset_resize(info, *root, 0, nr_bits, false, root); 65 } 66 67 static size_t bitset_size(unsigned int nr_bits) 68 { 69 return sizeof(unsigned long) * dm_div_up(nr_bits, BITS_PER_LONG); 70 } 71 72 /* 73 * Allocates memory for the in core bitset. 74 */ 75 static int writeset_alloc(struct writeset *ws, dm_block_t nr_blocks) 76 { 77 ws->bits = vzalloc(bitset_size(nr_blocks)); 78 if (!ws->bits) { 79 DMERR("%s: couldn't allocate in memory bitset", __func__); 80 return -ENOMEM; 81 } 82 83 return 0; 84 } 85 86 /* 87 * Wipes the in-core bitset, and creates a new on disk bitset. 88 */ 89 static int writeset_init(struct dm_disk_bitset *info, struct writeset *ws, 90 dm_block_t nr_blocks) 91 { 92 int r; 93 94 memset(ws->bits, 0, bitset_size(nr_blocks)); 95 96 ws->md.nr_bits = nr_blocks; 97 r = setup_on_disk_bitset(info, ws->md.nr_bits, &ws->md.root); 98 if (r) { 99 DMERR("%s: setup_on_disk_bitset failed", __func__); 100 return r; 101 } 102 103 return 0; 104 } 105 106 static bool writeset_marked(struct writeset *ws, dm_block_t block) 107 { 108 return test_bit(block, ws->bits); 109 } 110 111 static int writeset_marked_on_disk(struct dm_disk_bitset *info, 112 struct writeset_metadata *m, dm_block_t block, 113 bool *result) 114 { 115 int r; 116 dm_block_t old = m->root; 117 118 /* 119 * The bitset was flushed when it was archived, so we know there'll 120 * be no change to the root. 121 */ 122 r = dm_bitset_test_bit(info, m->root, block, &m->root, result); 123 if (r) { 124 DMERR("%s: dm_bitset_test_bit failed", __func__); 125 return r; 126 } 127 128 BUG_ON(m->root != old); 129 130 return r; 131 } 132 133 /* 134 * Returns < 0 on error, 0 if the bit wasn't previously set, 1 if it was. 135 */ 136 static int writeset_test_and_set(struct dm_disk_bitset *info, 137 struct writeset *ws, uint32_t block) 138 { 139 int r; 140 141 if (!test_bit(block, ws->bits)) { 142 r = dm_bitset_set_bit(info, ws->md.root, block, &ws->md.root); 143 if (r) { 144 /* FIXME: fail mode */ 145 return r; 146 } 147 148 return 0; 149 } 150 151 return 1; 152 } 153 154 /* 155 *-------------------------------------------------------------- 156 * On disk metadata layout 157 *-------------------------------------------------------------- 158 */ 159 #define SPACE_MAP_ROOT_SIZE 128 160 #define UUID_LEN 16 161 162 struct writeset_disk { 163 __le32 nr_bits; 164 __le64 root; 165 } __packed; 166 167 struct superblock_disk { 168 __le32 csum; 169 __le32 flags; 170 __le64 blocknr; 171 172 __u8 uuid[UUID_LEN]; 173 __le64 magic; 174 __le32 version; 175 176 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE]; 177 178 __le32 data_block_size; 179 __le32 metadata_block_size; 180 __le32 nr_blocks; 181 182 __le32 current_era; 183 struct writeset_disk current_writeset; 184 185 /* 186 * Only these two fields are valid within the metadata snapshot. 187 */ 188 __le64 writeset_tree_root; 189 __le64 era_array_root; 190 191 __le64 metadata_snap; 192 } __packed; 193 194 /* 195 *-------------------------------------------------------------- 196 * Superblock validation 197 *-------------------------------------------------------------- 198 */ 199 static void sb_prepare_for_write(const struct dm_block_validator *v, 200 struct dm_block *b, 201 size_t sb_block_size) 202 { 203 struct superblock_disk *disk = dm_block_data(b); 204 205 disk->blocknr = cpu_to_le64(dm_block_location(b)); 206 disk->csum = cpu_to_le32(dm_bm_checksum(&disk->flags, 207 sb_block_size - sizeof(__le32), 208 SUPERBLOCK_CSUM_XOR)); 209 } 210 211 static int check_metadata_version(struct superblock_disk *disk) 212 { 213 uint32_t metadata_version = le32_to_cpu(disk->version); 214 215 if (metadata_version < MIN_ERA_VERSION || metadata_version > MAX_ERA_VERSION) { 216 DMERR("Era metadata version %u found, but only versions between %u and %u supported.", 217 metadata_version, MIN_ERA_VERSION, MAX_ERA_VERSION); 218 return -EINVAL; 219 } 220 221 return 0; 222 } 223 224 static int sb_check(const struct dm_block_validator *v, 225 struct dm_block *b, 226 size_t sb_block_size) 227 { 228 struct superblock_disk *disk = dm_block_data(b); 229 __le32 csum_le; 230 231 if (dm_block_location(b) != le64_to_cpu(disk->blocknr)) { 232 DMERR("%s failed: blocknr %llu: wanted %llu", 233 __func__, le64_to_cpu(disk->blocknr), 234 (unsigned long long)dm_block_location(b)); 235 return -ENOTBLK; 236 } 237 238 if (le64_to_cpu(disk->magic) != SUPERBLOCK_MAGIC) { 239 DMERR("%s failed: magic %llu: wanted %llu", 240 __func__, le64_to_cpu(disk->magic), 241 (unsigned long long) SUPERBLOCK_MAGIC); 242 return -EILSEQ; 243 } 244 245 csum_le = cpu_to_le32(dm_bm_checksum(&disk->flags, 246 sb_block_size - sizeof(__le32), 247 SUPERBLOCK_CSUM_XOR)); 248 if (csum_le != disk->csum) { 249 DMERR("%s failed: csum %u: wanted %u", 250 __func__, le32_to_cpu(csum_le), le32_to_cpu(disk->csum)); 251 return -EILSEQ; 252 } 253 254 return check_metadata_version(disk); 255 } 256 257 static const struct dm_block_validator sb_validator = { 258 .name = "superblock", 259 .prepare_for_write = sb_prepare_for_write, 260 .check = sb_check 261 }; 262 263 /* 264 *-------------------------------------------------------------- 265 * Low level metadata handling 266 *-------------------------------------------------------------- 267 */ 268 #define DM_ERA_METADATA_BLOCK_SIZE 4096 269 #define ERA_MAX_CONCURRENT_LOCKS 5 270 271 struct era_metadata { 272 struct block_device *bdev; 273 struct dm_block_manager *bm; 274 struct dm_space_map *sm; 275 struct dm_transaction_manager *tm; 276 277 dm_block_t block_size; 278 uint32_t nr_blocks; 279 280 uint32_t current_era; 281 282 /* 283 * We preallocate 2 writesets. When an era rolls over we 284 * switch between them. This means the allocation is done at 285 * preresume time, rather than on the io path. 286 */ 287 struct writeset writesets[2]; 288 struct writeset *current_writeset; 289 290 dm_block_t writeset_tree_root; 291 dm_block_t era_array_root; 292 293 struct dm_disk_bitset bitset_info; 294 struct dm_btree_info writeset_tree_info; 295 struct dm_array_info era_array_info; 296 297 dm_block_t metadata_snap; 298 299 /* 300 * A flag that is set whenever a writeset has been archived. 301 */ 302 bool archived_writesets; 303 304 /* 305 * Reading the space map root can fail, so we read it into this 306 * buffer before the superblock is locked and updated. 307 */ 308 __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE]; 309 }; 310 311 static int superblock_read_lock(struct era_metadata *md, 312 struct dm_block **sblock) 313 { 314 return dm_bm_read_lock(md->bm, SUPERBLOCK_LOCATION, 315 &sb_validator, sblock); 316 } 317 318 static int superblock_lock_zero(struct era_metadata *md, 319 struct dm_block **sblock) 320 { 321 return dm_bm_write_lock_zero(md->bm, SUPERBLOCK_LOCATION, 322 &sb_validator, sblock); 323 } 324 325 static int superblock_lock(struct era_metadata *md, 326 struct dm_block **sblock) 327 { 328 return dm_bm_write_lock(md->bm, SUPERBLOCK_LOCATION, 329 &sb_validator, sblock); 330 } 331 332 /* FIXME: duplication with cache and thin */ 333 static int superblock_all_zeroes(struct dm_block_manager *bm, bool *result) 334 { 335 int r; 336 unsigned int i; 337 struct dm_block *b; 338 __le64 *data_le, zero = cpu_to_le64(0); 339 unsigned int sb_block_size = dm_bm_block_size(bm) / sizeof(__le64); 340 341 /* 342 * We can't use a validator here - it may be all zeroes. 343 */ 344 r = dm_bm_read_lock(bm, SUPERBLOCK_LOCATION, NULL, &b); 345 if (r) 346 return r; 347 348 data_le = dm_block_data(b); 349 *result = true; 350 for (i = 0; i < sb_block_size; i++) { 351 if (data_le[i] != zero) { 352 *result = false; 353 break; 354 } 355 } 356 357 dm_bm_unlock(b); 358 359 return 0; 360 } 361 362 /*----------------------------------------------------------------*/ 363 364 static void ws_pack(const struct writeset_metadata *core, struct writeset_disk *disk) 365 { 366 disk->nr_bits = cpu_to_le32(core->nr_bits); 367 disk->root = cpu_to_le64(core->root); 368 } 369 370 static void ws_unpack(const struct writeset_disk *disk, struct writeset_metadata *core) 371 { 372 core->nr_bits = le32_to_cpu(disk->nr_bits); 373 core->root = le64_to_cpu(disk->root); 374 } 375 376 static void ws_inc(void *context, const void *value, unsigned int count) 377 { 378 struct era_metadata *md = context; 379 struct writeset_disk ws_d; 380 dm_block_t b; 381 unsigned int i; 382 383 for (i = 0; i < count; i++) { 384 memcpy(&ws_d, value + (i * sizeof(ws_d)), sizeof(ws_d)); 385 b = le64_to_cpu(ws_d.root); 386 dm_tm_inc(md->tm, b); 387 } 388 } 389 390 static void ws_dec(void *context, const void *value, unsigned int count) 391 { 392 struct era_metadata *md = context; 393 struct writeset_disk ws_d; 394 dm_block_t b; 395 unsigned int i; 396 397 for (i = 0; i < count; i++) { 398 memcpy(&ws_d, value + (i * sizeof(ws_d)), sizeof(ws_d)); 399 b = le64_to_cpu(ws_d.root); 400 dm_bitset_del(&md->bitset_info, b); 401 } 402 } 403 404 static int ws_eq(void *context, const void *value1, const void *value2) 405 { 406 return !memcmp(value1, value2, sizeof(struct writeset_disk)); 407 } 408 409 /*----------------------------------------------------------------*/ 410 411 static void setup_writeset_tree_info(struct era_metadata *md) 412 { 413 struct dm_btree_value_type *vt = &md->writeset_tree_info.value_type; 414 415 md->writeset_tree_info.tm = md->tm; 416 md->writeset_tree_info.levels = 1; 417 vt->context = md; 418 vt->size = sizeof(struct writeset_disk); 419 vt->inc = ws_inc; 420 vt->dec = ws_dec; 421 vt->equal = ws_eq; 422 } 423 424 static void setup_era_array_info(struct era_metadata *md) 425 { 426 struct dm_btree_value_type vt; 427 428 vt.context = NULL; 429 vt.size = sizeof(__le32); 430 vt.inc = NULL; 431 vt.dec = NULL; 432 vt.equal = NULL; 433 434 dm_array_info_init(&md->era_array_info, md->tm, &vt); 435 } 436 437 static void setup_infos(struct era_metadata *md) 438 { 439 dm_disk_bitset_init(md->tm, &md->bitset_info); 440 setup_writeset_tree_info(md); 441 setup_era_array_info(md); 442 } 443 444 /*----------------------------------------------------------------*/ 445 446 static int create_fresh_metadata(struct era_metadata *md) 447 { 448 int r; 449 450 r = dm_tm_create_with_sm(md->bm, SUPERBLOCK_LOCATION, 451 &md->tm, &md->sm); 452 if (r < 0) { 453 DMERR("dm_tm_create_with_sm failed"); 454 return r; 455 } 456 457 setup_infos(md); 458 459 r = dm_btree_empty(&md->writeset_tree_info, &md->writeset_tree_root); 460 if (r) { 461 DMERR("couldn't create new writeset tree"); 462 goto bad; 463 } 464 465 r = dm_array_empty(&md->era_array_info, &md->era_array_root); 466 if (r) { 467 DMERR("couldn't create era array"); 468 goto bad; 469 } 470 471 return 0; 472 473 bad: 474 dm_sm_destroy(md->sm); 475 dm_tm_destroy(md->tm); 476 477 return r; 478 } 479 480 static int save_sm_root(struct era_metadata *md) 481 { 482 int r; 483 size_t metadata_len; 484 485 r = dm_sm_root_size(md->sm, &metadata_len); 486 if (r < 0) 487 return r; 488 489 return dm_sm_copy_root(md->sm, &md->metadata_space_map_root, 490 metadata_len); 491 } 492 493 static void copy_sm_root(struct era_metadata *md, struct superblock_disk *disk) 494 { 495 memcpy(&disk->metadata_space_map_root, 496 &md->metadata_space_map_root, 497 sizeof(md->metadata_space_map_root)); 498 } 499 500 /* 501 * Writes a superblock, including the static fields that don't get updated 502 * with every commit (possible optimisation here). 'md' should be fully 503 * constructed when this is called. 504 */ 505 static void prepare_superblock(struct era_metadata *md, struct superblock_disk *disk) 506 { 507 disk->magic = cpu_to_le64(SUPERBLOCK_MAGIC); 508 disk->flags = cpu_to_le32(0ul); 509 510 /* FIXME: can't keep blanking the uuid (uuid is currently unused though) */ 511 memset(disk->uuid, 0, sizeof(disk->uuid)); 512 disk->version = cpu_to_le32(MAX_ERA_VERSION); 513 514 copy_sm_root(md, disk); 515 516 disk->data_block_size = cpu_to_le32(md->block_size); 517 disk->metadata_block_size = cpu_to_le32(DM_ERA_METADATA_BLOCK_SIZE >> SECTOR_SHIFT); 518 disk->nr_blocks = cpu_to_le32(md->nr_blocks); 519 disk->current_era = cpu_to_le32(md->current_era); 520 521 ws_pack(&md->current_writeset->md, &disk->current_writeset); 522 disk->writeset_tree_root = cpu_to_le64(md->writeset_tree_root); 523 disk->era_array_root = cpu_to_le64(md->era_array_root); 524 disk->metadata_snap = cpu_to_le64(md->metadata_snap); 525 } 526 527 static int write_superblock(struct era_metadata *md) 528 { 529 int r; 530 struct dm_block *sblock; 531 struct superblock_disk *disk; 532 533 r = save_sm_root(md); 534 if (r) { 535 DMERR("%s: save_sm_root failed", __func__); 536 return r; 537 } 538 539 r = superblock_lock_zero(md, &sblock); 540 if (r) 541 return r; 542 543 disk = dm_block_data(sblock); 544 prepare_superblock(md, disk); 545 546 return dm_tm_commit(md->tm, sblock); 547 } 548 549 /* 550 * Assumes block_size and the infos are set. 551 */ 552 static int format_metadata(struct era_metadata *md) 553 { 554 int r; 555 556 r = create_fresh_metadata(md); 557 if (r) 558 return r; 559 560 r = write_superblock(md); 561 if (r) { 562 dm_sm_destroy(md->sm); 563 dm_tm_destroy(md->tm); 564 return r; 565 } 566 567 return 0; 568 } 569 570 static int open_metadata(struct era_metadata *md) 571 { 572 int r; 573 struct dm_block *sblock; 574 struct superblock_disk *disk; 575 576 r = superblock_read_lock(md, &sblock); 577 if (r) { 578 DMERR("couldn't read_lock superblock"); 579 return r; 580 } 581 582 disk = dm_block_data(sblock); 583 584 /* Verify the data block size hasn't changed */ 585 if (le32_to_cpu(disk->data_block_size) != md->block_size) { 586 DMERR("changing the data block size (from %u to %llu) is not supported", 587 le32_to_cpu(disk->data_block_size), md->block_size); 588 r = -EINVAL; 589 goto bad; 590 } 591 592 r = dm_tm_open_with_sm(md->bm, SUPERBLOCK_LOCATION, 593 disk->metadata_space_map_root, 594 sizeof(disk->metadata_space_map_root), 595 &md->tm, &md->sm); 596 if (r) { 597 DMERR("dm_tm_open_with_sm failed"); 598 goto bad; 599 } 600 601 setup_infos(md); 602 603 md->nr_blocks = le32_to_cpu(disk->nr_blocks); 604 md->current_era = le32_to_cpu(disk->current_era); 605 606 ws_unpack(&disk->current_writeset, &md->current_writeset->md); 607 md->writeset_tree_root = le64_to_cpu(disk->writeset_tree_root); 608 md->era_array_root = le64_to_cpu(disk->era_array_root); 609 md->metadata_snap = le64_to_cpu(disk->metadata_snap); 610 md->archived_writesets = true; 611 612 dm_bm_unlock(sblock); 613 614 return 0; 615 616 bad: 617 dm_bm_unlock(sblock); 618 return r; 619 } 620 621 static int open_or_format_metadata(struct era_metadata *md, 622 bool may_format) 623 { 624 int r; 625 bool unformatted = false; 626 627 r = superblock_all_zeroes(md->bm, &unformatted); 628 if (r) 629 return r; 630 631 if (unformatted) 632 return may_format ? format_metadata(md) : -EPERM; 633 634 return open_metadata(md); 635 } 636 637 static int create_persistent_data_objects(struct era_metadata *md, 638 bool may_format) 639 { 640 int r; 641 642 md->bm = dm_block_manager_create(md->bdev, DM_ERA_METADATA_BLOCK_SIZE, 643 ERA_MAX_CONCURRENT_LOCKS); 644 if (IS_ERR(md->bm)) { 645 DMERR("could not create block manager"); 646 return PTR_ERR(md->bm); 647 } 648 649 r = open_or_format_metadata(md, may_format); 650 if (r) 651 dm_block_manager_destroy(md->bm); 652 653 return r; 654 } 655 656 static void destroy_persistent_data_objects(struct era_metadata *md) 657 { 658 dm_sm_destroy(md->sm); 659 dm_tm_destroy(md->tm); 660 dm_block_manager_destroy(md->bm); 661 } 662 663 /* 664 * This waits until all era_map threads have picked up the new filter. 665 */ 666 static void swap_writeset(struct era_metadata *md, struct writeset *new_writeset) 667 { 668 rcu_assign_pointer(md->current_writeset, new_writeset); 669 synchronize_rcu(); 670 } 671 672 /* 673 *------------------------------------------------------------------------ 674 * Writesets get 'digested' into the main era array. 675 * 676 * We're using a coroutine here so the worker thread can do the digestion, 677 * thus avoiding synchronisation of the metadata. Digesting a whole 678 * writeset in one go would cause too much latency. 679 *------------------------------------------------------------------------ 680 */ 681 struct digest { 682 uint32_t era; 683 unsigned int nr_bits, current_bit; 684 struct writeset_metadata writeset; 685 __le32 value; 686 struct dm_disk_bitset info; 687 688 int (*step)(struct era_metadata *md, struct digest *d); 689 }; 690 691 static int metadata_digest_lookup_writeset(struct era_metadata *md, 692 struct digest *d); 693 694 static int metadata_digest_remove_writeset(struct era_metadata *md, 695 struct digest *d) 696 { 697 int r; 698 uint64_t key = d->era; 699 700 r = dm_btree_remove(&md->writeset_tree_info, md->writeset_tree_root, 701 &key, &md->writeset_tree_root); 702 if (r) { 703 DMERR("%s: dm_btree_remove failed", __func__); 704 return r; 705 } 706 707 d->step = metadata_digest_lookup_writeset; 708 return 0; 709 } 710 711 #define INSERTS_PER_STEP 100 712 713 static int metadata_digest_transcribe_writeset(struct era_metadata *md, 714 struct digest *d) 715 { 716 int r; 717 bool marked; 718 unsigned int b, e = min(d->current_bit + INSERTS_PER_STEP, d->nr_bits); 719 720 for (b = d->current_bit; b < e; b++) { 721 r = writeset_marked_on_disk(&d->info, &d->writeset, b, &marked); 722 if (r) { 723 DMERR("%s: writeset_marked_on_disk failed", __func__); 724 return r; 725 } 726 727 if (!marked) 728 continue; 729 730 __dm_bless_for_disk(&d->value); 731 r = dm_array_set_value(&md->era_array_info, md->era_array_root, 732 b, &d->value, &md->era_array_root); 733 if (r) { 734 DMERR("%s: dm_array_set_value failed", __func__); 735 return r; 736 } 737 } 738 739 if (b == d->nr_bits) 740 d->step = metadata_digest_remove_writeset; 741 else 742 d->current_bit = b; 743 744 return 0; 745 } 746 747 static int metadata_digest_lookup_writeset(struct era_metadata *md, 748 struct digest *d) 749 { 750 int r; 751 uint64_t key; 752 struct writeset_disk disk; 753 754 r = dm_btree_find_lowest_key(&md->writeset_tree_info, 755 md->writeset_tree_root, &key); 756 if (r < 0) 757 return r; 758 759 d->era = key; 760 761 r = dm_btree_lookup(&md->writeset_tree_info, 762 md->writeset_tree_root, &key, &disk); 763 if (r) { 764 if (r == -ENODATA) { 765 d->step = NULL; 766 return 0; 767 } 768 769 DMERR("%s: dm_btree_lookup failed", __func__); 770 return r; 771 } 772 773 ws_unpack(&disk, &d->writeset); 774 d->value = cpu_to_le32(key); 775 776 /* 777 * We initialise another bitset info to avoid any caching side effects 778 * with the previous one. 779 */ 780 dm_disk_bitset_init(md->tm, &d->info); 781 782 d->nr_bits = min(d->writeset.nr_bits, md->nr_blocks); 783 d->current_bit = 0; 784 d->step = metadata_digest_transcribe_writeset; 785 786 return 0; 787 } 788 789 static int metadata_digest_start(struct era_metadata *md, struct digest *d) 790 { 791 if (d->step) 792 return 0; 793 794 memset(d, 0, sizeof(*d)); 795 d->step = metadata_digest_lookup_writeset; 796 797 return 0; 798 } 799 800 /* 801 *----------------------------------------------------------------- 802 * High level metadata interface. Target methods should use these, 803 * and not the lower level ones. 804 *----------------------------------------------------------------- 805 */ 806 static struct era_metadata *metadata_open(struct block_device *bdev, 807 sector_t block_size, 808 bool may_format) 809 { 810 int r; 811 struct era_metadata *md = kzalloc_obj(*md); 812 813 if (!md) { 814 DMERR("could not allocate metadata struct"); 815 return ERR_PTR(-ENOMEM); 816 } 817 818 md->bdev = bdev; 819 md->block_size = block_size; 820 821 md->writesets[0].md.root = INVALID_WRITESET_ROOT; 822 md->writesets[1].md.root = INVALID_WRITESET_ROOT; 823 md->current_writeset = &md->writesets[0]; 824 825 r = create_persistent_data_objects(md, may_format); 826 if (r) { 827 kfree(md); 828 return ERR_PTR(r); 829 } 830 831 return md; 832 } 833 834 static void metadata_close(struct era_metadata *md) 835 { 836 writeset_free(&md->writesets[0]); 837 writeset_free(&md->writesets[1]); 838 destroy_persistent_data_objects(md); 839 kfree(md); 840 } 841 842 static bool valid_nr_blocks(dm_block_t n) 843 { 844 /* 845 * dm_bitset restricts us to 2^32. test_bit & co. restrict us 846 * further to 2^31 - 1 847 */ 848 return n < (1ull << 31); 849 } 850 851 static int metadata_resize(struct era_metadata *md, void *arg) 852 { 853 int r; 854 dm_block_t *new_size = arg; 855 __le32 value; 856 857 if (!valid_nr_blocks(*new_size)) { 858 DMERR("Invalid number of origin blocks %llu", 859 (unsigned long long) *new_size); 860 return -EINVAL; 861 } 862 863 writeset_free(&md->writesets[0]); 864 writeset_free(&md->writesets[1]); 865 866 r = writeset_alloc(&md->writesets[0], *new_size); 867 if (r) { 868 DMERR("%s: writeset_alloc failed for writeset 0", __func__); 869 return r; 870 } 871 872 r = writeset_alloc(&md->writesets[1], *new_size); 873 if (r) { 874 DMERR("%s: writeset_alloc failed for writeset 1", __func__); 875 writeset_free(&md->writesets[0]); 876 return r; 877 } 878 879 value = cpu_to_le32(0u); 880 __dm_bless_for_disk(&value); 881 r = dm_array_resize(&md->era_array_info, md->era_array_root, 882 md->nr_blocks, *new_size, 883 &value, &md->era_array_root); 884 if (r) { 885 DMERR("%s: dm_array_resize failed", __func__); 886 writeset_free(&md->writesets[0]); 887 writeset_free(&md->writesets[1]); 888 return r; 889 } 890 891 md->nr_blocks = *new_size; 892 return 0; 893 } 894 895 static int metadata_era_archive(struct era_metadata *md) 896 { 897 int r; 898 uint64_t keys[1]; 899 struct writeset_disk value; 900 901 r = dm_bitset_flush(&md->bitset_info, md->current_writeset->md.root, 902 &md->current_writeset->md.root); 903 if (r) { 904 DMERR("%s: dm_bitset_flush failed", __func__); 905 return r; 906 } 907 908 ws_pack(&md->current_writeset->md, &value); 909 910 keys[0] = md->current_era; 911 __dm_bless_for_disk(&value); 912 r = dm_btree_insert(&md->writeset_tree_info, md->writeset_tree_root, 913 keys, &value, &md->writeset_tree_root); 914 if (r) { 915 DMERR("%s: couldn't insert writeset into btree", __func__); 916 /* FIXME: fail mode */ 917 return r; 918 } 919 920 md->current_writeset->md.root = INVALID_WRITESET_ROOT; 921 md->archived_writesets = true; 922 923 return 0; 924 } 925 926 static struct writeset *next_writeset(struct era_metadata *md) 927 { 928 return (md->current_writeset == &md->writesets[0]) ? 929 &md->writesets[1] : &md->writesets[0]; 930 } 931 932 static int metadata_new_era(struct era_metadata *md) 933 { 934 int r; 935 struct writeset *new_writeset = next_writeset(md); 936 937 r = writeset_init(&md->bitset_info, new_writeset, md->nr_blocks); 938 if (r) { 939 DMERR("%s: writeset_init failed", __func__); 940 return r; 941 } 942 943 swap_writeset(md, new_writeset); 944 md->current_era++; 945 946 return 0; 947 } 948 949 static int metadata_era_rollover(struct era_metadata *md) 950 { 951 int r; 952 953 if (md->current_writeset->md.root != INVALID_WRITESET_ROOT) { 954 r = metadata_era_archive(md); 955 if (r) { 956 DMERR("%s: metadata_archive_era failed", __func__); 957 /* FIXME: fail mode? */ 958 return r; 959 } 960 } 961 962 r = metadata_new_era(md); 963 if (r) { 964 DMERR("%s: new era failed", __func__); 965 /* FIXME: fail mode */ 966 return r; 967 } 968 969 return 0; 970 } 971 972 static bool metadata_current_marked(struct era_metadata *md, dm_block_t block) 973 { 974 bool r; 975 struct writeset *ws; 976 977 rcu_read_lock(); 978 ws = rcu_dereference(md->current_writeset); 979 r = writeset_marked(ws, block); 980 rcu_read_unlock(); 981 982 return r; 983 } 984 985 static int metadata_commit(struct era_metadata *md) 986 { 987 int r; 988 struct dm_block *sblock; 989 990 if (md->current_writeset->md.root != INVALID_WRITESET_ROOT) { 991 r = dm_bitset_flush(&md->bitset_info, md->current_writeset->md.root, 992 &md->current_writeset->md.root); 993 if (r) { 994 DMERR("%s: bitset flush failed", __func__); 995 return r; 996 } 997 } 998 999 r = dm_tm_pre_commit(md->tm); 1000 if (r) { 1001 DMERR("%s: pre commit failed", __func__); 1002 return r; 1003 } 1004 1005 r = save_sm_root(md); 1006 if (r) { 1007 DMERR("%s: save_sm_root failed", __func__); 1008 return r; 1009 } 1010 1011 r = superblock_lock(md, &sblock); 1012 if (r) { 1013 DMERR("%s: superblock lock failed", __func__); 1014 return r; 1015 } 1016 1017 prepare_superblock(md, dm_block_data(sblock)); 1018 1019 return dm_tm_commit(md->tm, sblock); 1020 } 1021 1022 static int metadata_checkpoint(struct era_metadata *md) 1023 { 1024 /* 1025 * For now we just rollover, but later I want to put a check in to 1026 * avoid this if the filter is still pretty fresh. 1027 */ 1028 return metadata_era_rollover(md); 1029 } 1030 1031 /* 1032 * Metadata snapshots allow userland to access era data. 1033 */ 1034 static int metadata_take_snap(struct era_metadata *md) 1035 { 1036 int r, inc; 1037 struct dm_block *clone; 1038 1039 if (md->metadata_snap != SUPERBLOCK_LOCATION) { 1040 DMERR("%s: metadata snapshot already exists", __func__); 1041 return -EINVAL; 1042 } 1043 1044 r = metadata_era_rollover(md); 1045 if (r) { 1046 DMERR("%s: era rollover failed", __func__); 1047 return r; 1048 } 1049 1050 r = metadata_commit(md); 1051 if (r) { 1052 DMERR("%s: pre commit failed", __func__); 1053 return r; 1054 } 1055 1056 r = dm_sm_inc_block(md->sm, SUPERBLOCK_LOCATION); 1057 if (r) { 1058 DMERR("%s: couldn't increment superblock", __func__); 1059 return r; 1060 } 1061 1062 r = dm_tm_shadow_block(md->tm, SUPERBLOCK_LOCATION, 1063 &sb_validator, &clone, &inc); 1064 if (r) { 1065 DMERR("%s: couldn't shadow superblock", __func__); 1066 dm_sm_dec_block(md->sm, SUPERBLOCK_LOCATION); 1067 return r; 1068 } 1069 BUG_ON(!inc); 1070 1071 r = dm_sm_inc_block(md->sm, md->writeset_tree_root); 1072 if (r) { 1073 DMERR("%s: couldn't inc writeset tree root", __func__); 1074 dm_tm_unlock(md->tm, clone); 1075 return r; 1076 } 1077 1078 r = dm_sm_inc_block(md->sm, md->era_array_root); 1079 if (r) { 1080 DMERR("%s: couldn't inc era tree root", __func__); 1081 dm_sm_dec_block(md->sm, md->writeset_tree_root); 1082 dm_tm_unlock(md->tm, clone); 1083 return r; 1084 } 1085 1086 md->metadata_snap = dm_block_location(clone); 1087 1088 dm_tm_unlock(md->tm, clone); 1089 1090 return 0; 1091 } 1092 1093 static int metadata_drop_snap(struct era_metadata *md) 1094 { 1095 int r; 1096 dm_block_t location; 1097 struct dm_block *clone; 1098 struct superblock_disk *disk; 1099 1100 if (md->metadata_snap == SUPERBLOCK_LOCATION) { 1101 DMERR("%s: no snap to drop", __func__); 1102 return -EINVAL; 1103 } 1104 1105 r = dm_tm_read_lock(md->tm, md->metadata_snap, &sb_validator, &clone); 1106 if (r) { 1107 DMERR("%s: couldn't read lock superblock clone", __func__); 1108 return r; 1109 } 1110 1111 /* 1112 * Whatever happens now we'll commit with no record of the metadata 1113 * snap. 1114 */ 1115 md->metadata_snap = SUPERBLOCK_LOCATION; 1116 1117 disk = dm_block_data(clone); 1118 r = dm_btree_del(&md->writeset_tree_info, 1119 le64_to_cpu(disk->writeset_tree_root)); 1120 if (r) { 1121 DMERR("%s: error deleting writeset tree clone", __func__); 1122 dm_tm_unlock(md->tm, clone); 1123 return r; 1124 } 1125 1126 r = dm_array_del(&md->era_array_info, le64_to_cpu(disk->era_array_root)); 1127 if (r) { 1128 DMERR("%s: error deleting era array clone", __func__); 1129 dm_tm_unlock(md->tm, clone); 1130 return r; 1131 } 1132 1133 location = dm_block_location(clone); 1134 dm_tm_unlock(md->tm, clone); 1135 1136 return dm_sm_dec_block(md->sm, location); 1137 } 1138 1139 struct metadata_stats { 1140 dm_block_t used; 1141 dm_block_t total; 1142 dm_block_t snap; 1143 uint32_t era; 1144 }; 1145 1146 static int metadata_get_stats(struct era_metadata *md, void *ptr) 1147 { 1148 int r; 1149 struct metadata_stats *s = ptr; 1150 dm_block_t nr_free, nr_total; 1151 1152 r = dm_sm_get_nr_free(md->sm, &nr_free); 1153 if (r) { 1154 DMERR("dm_sm_get_nr_free returned %d", r); 1155 return r; 1156 } 1157 1158 r = dm_sm_get_nr_blocks(md->sm, &nr_total); 1159 if (r) { 1160 DMERR("dm_pool_get_metadata_dev_size returned %d", r); 1161 return r; 1162 } 1163 1164 s->used = nr_total - nr_free; 1165 s->total = nr_total; 1166 s->snap = md->metadata_snap; 1167 s->era = md->current_era; 1168 1169 return 0; 1170 } 1171 1172 /*----------------------------------------------------------------*/ 1173 1174 struct era { 1175 struct dm_target *ti; 1176 1177 struct dm_dev *metadata_dev; 1178 struct dm_dev *origin_dev; 1179 1180 dm_block_t nr_blocks; 1181 uint32_t sectors_per_block; 1182 int sectors_per_block_shift; 1183 struct era_metadata *md; 1184 1185 struct workqueue_struct *wq; 1186 struct work_struct worker; 1187 1188 spinlock_t deferred_lock; 1189 struct bio_list deferred_bios; 1190 1191 spinlock_t rpc_lock; 1192 struct list_head rpc_calls; 1193 1194 struct digest digest; 1195 atomic_t suspended; 1196 }; 1197 1198 struct rpc { 1199 struct list_head list; 1200 1201 int (*fn0)(struct era_metadata *md); 1202 int (*fn1)(struct era_metadata *md, void *ref); 1203 void *arg; 1204 int result; 1205 1206 struct completion complete; 1207 }; 1208 1209 /* 1210 *--------------------------------------------------------------- 1211 * Remapping. 1212 *--------------------------------------------------------------- 1213 */ 1214 static bool block_size_is_power_of_two(struct era *era) 1215 { 1216 return era->sectors_per_block_shift >= 0; 1217 } 1218 1219 static dm_block_t get_block(struct era *era, struct bio *bio) 1220 { 1221 sector_t block_nr = bio->bi_iter.bi_sector; 1222 1223 if (!block_size_is_power_of_two(era)) 1224 (void) sector_div(block_nr, era->sectors_per_block); 1225 else 1226 block_nr >>= era->sectors_per_block_shift; 1227 1228 return block_nr; 1229 } 1230 1231 static void remap_to_origin(struct era *era, struct bio *bio) 1232 { 1233 bio_set_dev(bio, era->origin_dev->bdev); 1234 bio->bi_iter.bi_sector = dm_target_offset(era->ti, bio->bi_iter.bi_sector); 1235 } 1236 1237 /* 1238 *-------------------------------------------------------------- 1239 * Worker thread 1240 *-------------------------------------------------------------- 1241 */ 1242 static void wake_worker(struct era *era) 1243 { 1244 if (!atomic_read(&era->suspended)) 1245 queue_work(era->wq, &era->worker); 1246 } 1247 1248 static void process_old_eras(struct era *era) 1249 { 1250 int r; 1251 1252 if (!era->digest.step) 1253 return; 1254 1255 r = era->digest.step(era->md, &era->digest); 1256 if (r < 0) { 1257 DMERR("%s: digest step failed, stopping digestion", __func__); 1258 era->digest.step = NULL; 1259 1260 } else if (era->digest.step) 1261 wake_worker(era); 1262 } 1263 1264 static void process_deferred_bios(struct era *era) 1265 { 1266 int r; 1267 struct bio_list deferred_bios, marked_bios; 1268 struct bio *bio; 1269 struct blk_plug plug; 1270 bool commit_needed = false; 1271 bool failed = false; 1272 struct writeset *ws = era->md->current_writeset; 1273 1274 bio_list_init(&deferred_bios); 1275 bio_list_init(&marked_bios); 1276 1277 spin_lock(&era->deferred_lock); 1278 bio_list_merge_init(&deferred_bios, &era->deferred_bios); 1279 spin_unlock(&era->deferred_lock); 1280 1281 if (bio_list_empty(&deferred_bios)) 1282 return; 1283 1284 while ((bio = bio_list_pop(&deferred_bios))) { 1285 r = writeset_test_and_set(&era->md->bitset_info, ws, 1286 get_block(era, bio)); 1287 if (r < 0) { 1288 /* 1289 * This is bad news, we need to rollback. 1290 * FIXME: finish. 1291 */ 1292 failed = true; 1293 } else if (r == 0) 1294 commit_needed = true; 1295 1296 bio_list_add(&marked_bios, bio); 1297 } 1298 1299 if (commit_needed) { 1300 r = metadata_commit(era->md); 1301 if (r) 1302 failed = true; 1303 } 1304 1305 if (failed) 1306 while ((bio = bio_list_pop(&marked_bios))) 1307 bio_io_error(bio); 1308 else { 1309 blk_start_plug(&plug); 1310 while ((bio = bio_list_pop(&marked_bios))) { 1311 /* 1312 * Only update the in-core writeset if the on-disk one 1313 * was updated too. 1314 */ 1315 if (commit_needed) 1316 set_bit(get_block(era, bio), ws->bits); 1317 submit_bio_noacct(bio); 1318 } 1319 blk_finish_plug(&plug); 1320 } 1321 } 1322 1323 static void process_rpc_calls(struct era *era) 1324 { 1325 int r; 1326 bool need_commit = false; 1327 struct list_head calls; 1328 struct rpc *rpc, *tmp; 1329 1330 INIT_LIST_HEAD(&calls); 1331 spin_lock(&era->rpc_lock); 1332 list_splice_init(&era->rpc_calls, &calls); 1333 spin_unlock(&era->rpc_lock); 1334 1335 list_for_each_entry_safe(rpc, tmp, &calls, list) { 1336 rpc->result = rpc->fn0 ? rpc->fn0(era->md) : rpc->fn1(era->md, rpc->arg); 1337 need_commit = true; 1338 } 1339 1340 if (need_commit) { 1341 r = metadata_commit(era->md); 1342 if (r) 1343 list_for_each_entry_safe(rpc, tmp, &calls, list) 1344 rpc->result = r; 1345 } 1346 1347 list_for_each_entry_safe(rpc, tmp, &calls, list) 1348 complete(&rpc->complete); 1349 } 1350 1351 static void kick_off_digest(struct era *era) 1352 { 1353 if (era->md->archived_writesets) { 1354 era->md->archived_writesets = false; 1355 metadata_digest_start(era->md, &era->digest); 1356 } 1357 } 1358 1359 static void do_work(struct work_struct *ws) 1360 { 1361 struct era *era = container_of(ws, struct era, worker); 1362 1363 kick_off_digest(era); 1364 process_old_eras(era); 1365 process_deferred_bios(era); 1366 process_rpc_calls(era); 1367 } 1368 1369 static void defer_bio(struct era *era, struct bio *bio) 1370 { 1371 spin_lock(&era->deferred_lock); 1372 bio_list_add(&era->deferred_bios, bio); 1373 spin_unlock(&era->deferred_lock); 1374 1375 wake_worker(era); 1376 } 1377 1378 /* 1379 * Make an rpc call to the worker to change the metadata. 1380 */ 1381 static int perform_rpc(struct era *era, struct rpc *rpc) 1382 { 1383 rpc->result = 0; 1384 init_completion(&rpc->complete); 1385 1386 spin_lock(&era->rpc_lock); 1387 list_add(&rpc->list, &era->rpc_calls); 1388 spin_unlock(&era->rpc_lock); 1389 1390 wake_worker(era); 1391 wait_for_completion(&rpc->complete); 1392 1393 return rpc->result; 1394 } 1395 1396 static int in_worker0(struct era *era, int (*fn)(struct era_metadata *md)) 1397 { 1398 struct rpc rpc; 1399 1400 rpc.fn0 = fn; 1401 rpc.fn1 = NULL; 1402 1403 return perform_rpc(era, &rpc); 1404 } 1405 1406 static int in_worker1(struct era *era, 1407 int (*fn)(struct era_metadata *md, void *ref), void *arg) 1408 { 1409 struct rpc rpc; 1410 1411 rpc.fn0 = NULL; 1412 rpc.fn1 = fn; 1413 rpc.arg = arg; 1414 1415 return perform_rpc(era, &rpc); 1416 } 1417 1418 static void start_worker(struct era *era) 1419 { 1420 atomic_set(&era->suspended, 0); 1421 } 1422 1423 static void stop_worker(struct era *era) 1424 { 1425 atomic_set(&era->suspended, 1); 1426 drain_workqueue(era->wq); 1427 } 1428 1429 /* 1430 *-------------------------------------------------------------- 1431 * Target methods 1432 *-------------------------------------------------------------- 1433 */ 1434 static void era_destroy(struct era *era) 1435 { 1436 if (era->md) 1437 metadata_close(era->md); 1438 1439 if (era->wq) 1440 destroy_workqueue(era->wq); 1441 1442 if (era->origin_dev) 1443 dm_put_device(era->ti, era->origin_dev); 1444 1445 if (era->metadata_dev) 1446 dm_put_device(era->ti, era->metadata_dev); 1447 1448 kfree(era); 1449 } 1450 1451 static dm_block_t calc_nr_blocks(struct era *era) 1452 { 1453 return dm_sector_div_up(era->ti->len, era->sectors_per_block); 1454 } 1455 1456 static bool valid_block_size(dm_block_t block_size) 1457 { 1458 bool greater_than_zero = block_size > 0; 1459 bool multiple_of_min_block_size = (block_size & (MIN_BLOCK_SIZE - 1)) == 0; 1460 1461 return greater_than_zero && multiple_of_min_block_size; 1462 } 1463 1464 /* 1465 * <metadata dev> <data dev> <data block size (sectors)> 1466 */ 1467 static int era_ctr(struct dm_target *ti, unsigned int argc, char **argv) 1468 { 1469 int r; 1470 char dummy; 1471 struct era *era; 1472 struct era_metadata *md; 1473 1474 if (argc != 3) { 1475 ti->error = "Invalid argument count"; 1476 return -EINVAL; 1477 } 1478 1479 era = kzalloc_obj(*era); 1480 if (!era) { 1481 ti->error = "Error allocating era structure"; 1482 return -ENOMEM; 1483 } 1484 1485 era->ti = ti; 1486 1487 r = dm_get_device(ti, argv[0], BLK_OPEN_READ | BLK_OPEN_WRITE, 1488 &era->metadata_dev); 1489 if (r) { 1490 ti->error = "Error opening metadata device"; 1491 era_destroy(era); 1492 return r; 1493 } 1494 1495 r = dm_get_device(ti, argv[1], BLK_OPEN_READ | BLK_OPEN_WRITE, 1496 &era->origin_dev); 1497 if (r) { 1498 ti->error = "Error opening data device"; 1499 era_destroy(era); 1500 return r; 1501 } 1502 1503 r = sscanf(argv[2], "%u%c", &era->sectors_per_block, &dummy); 1504 if (r != 1) { 1505 ti->error = "Error parsing block size"; 1506 era_destroy(era); 1507 return -EINVAL; 1508 } 1509 1510 r = dm_set_target_max_io_len(ti, era->sectors_per_block); 1511 if (r) { 1512 ti->error = "could not set max io len"; 1513 era_destroy(era); 1514 return r; 1515 } 1516 1517 if (!valid_block_size(era->sectors_per_block)) { 1518 ti->error = "Invalid block size"; 1519 era_destroy(era); 1520 return -EINVAL; 1521 } 1522 if (era->sectors_per_block & (era->sectors_per_block - 1)) 1523 era->sectors_per_block_shift = -1; 1524 else 1525 era->sectors_per_block_shift = __ffs(era->sectors_per_block); 1526 1527 md = metadata_open(era->metadata_dev->bdev, era->sectors_per_block, true); 1528 if (IS_ERR(md)) { 1529 ti->error = "Error reading metadata"; 1530 era_destroy(era); 1531 return PTR_ERR(md); 1532 } 1533 era->md = md; 1534 1535 era->wq = alloc_ordered_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM); 1536 if (!era->wq) { 1537 ti->error = "could not create workqueue for metadata object"; 1538 era_destroy(era); 1539 return -ENOMEM; 1540 } 1541 INIT_WORK(&era->worker, do_work); 1542 1543 spin_lock_init(&era->deferred_lock); 1544 bio_list_init(&era->deferred_bios); 1545 1546 spin_lock_init(&era->rpc_lock); 1547 INIT_LIST_HEAD(&era->rpc_calls); 1548 1549 ti->private = era; 1550 ti->num_flush_bios = 1; 1551 ti->flush_supported = true; 1552 1553 ti->num_discard_bios = 1; 1554 1555 return 0; 1556 } 1557 1558 static void era_dtr(struct dm_target *ti) 1559 { 1560 era_destroy(ti->private); 1561 } 1562 1563 static int era_map(struct dm_target *ti, struct bio *bio) 1564 { 1565 struct era *era = ti->private; 1566 dm_block_t block; 1567 1568 /* 1569 * All bios get remapped to the origin device. We do this now, but 1570 * it may not get issued until later. Depending on whether the 1571 * block is marked in this era. 1572 */ 1573 remap_to_origin(era, bio); 1574 block = get_block(era, bio); 1575 1576 /* 1577 * REQ_PREFLUSH bios carry no data, so we're not interested in them. 1578 */ 1579 if (!(bio->bi_opf & REQ_PREFLUSH) && 1580 (bio_data_dir(bio) == WRITE) && 1581 !metadata_current_marked(era->md, block)) { 1582 defer_bio(era, bio); 1583 return DM_MAPIO_SUBMITTED; 1584 } 1585 1586 return DM_MAPIO_REMAPPED; 1587 } 1588 1589 static void era_postsuspend(struct dm_target *ti) 1590 { 1591 int r; 1592 struct era *era = ti->private; 1593 1594 r = in_worker0(era, metadata_era_archive); 1595 if (r) { 1596 DMERR("%s: couldn't archive current era", __func__); 1597 /* FIXME: fail mode */ 1598 } 1599 1600 stop_worker(era); 1601 1602 r = metadata_commit(era->md); 1603 if (r) { 1604 DMERR("%s: metadata_commit failed", __func__); 1605 /* FIXME: fail mode */ 1606 } 1607 } 1608 1609 static int era_preresume(struct dm_target *ti) 1610 { 1611 int r; 1612 struct era *era = ti->private; 1613 dm_block_t new_size = calc_nr_blocks(era); 1614 1615 if (era->nr_blocks != new_size) { 1616 r = metadata_resize(era->md, &new_size); 1617 if (r) { 1618 DMERR("%s: metadata_resize failed", __func__); 1619 return r; 1620 } 1621 1622 r = metadata_commit(era->md); 1623 if (r) { 1624 DMERR("%s: metadata_commit failed", __func__); 1625 return r; 1626 } 1627 1628 era->nr_blocks = new_size; 1629 } 1630 1631 start_worker(era); 1632 1633 r = in_worker0(era, metadata_era_rollover); 1634 if (r) { 1635 DMERR("%s: metadata_era_rollover failed", __func__); 1636 return r; 1637 } 1638 1639 return 0; 1640 } 1641 1642 /* 1643 * Status format: 1644 * 1645 * <metadata block size> <#used metadata blocks>/<#total metadata blocks> 1646 * <current era> <held metadata root | '-'> 1647 */ 1648 static void era_status(struct dm_target *ti, status_type_t type, 1649 unsigned int status_flags, char *result, unsigned int maxlen) 1650 { 1651 int r; 1652 struct era *era = ti->private; 1653 ssize_t sz = 0; 1654 struct metadata_stats stats; 1655 char buf[BDEVNAME_SIZE]; 1656 1657 switch (type) { 1658 case STATUSTYPE_INFO: 1659 r = in_worker1(era, metadata_get_stats, &stats); 1660 if (r) 1661 goto err; 1662 1663 DMEMIT("%u %llu/%llu %u", 1664 (unsigned int) (DM_ERA_METADATA_BLOCK_SIZE >> SECTOR_SHIFT), 1665 (unsigned long long) stats.used, 1666 (unsigned long long) stats.total, 1667 (unsigned int) stats.era); 1668 1669 if (stats.snap != SUPERBLOCK_LOCATION) 1670 DMEMIT(" %llu", stats.snap); 1671 else 1672 DMEMIT(" -"); 1673 break; 1674 1675 case STATUSTYPE_TABLE: 1676 format_dev_t(buf, era->metadata_dev->bdev->bd_dev); 1677 DMEMIT("%s ", buf); 1678 format_dev_t(buf, era->origin_dev->bdev->bd_dev); 1679 DMEMIT("%s %u", buf, era->sectors_per_block); 1680 break; 1681 1682 case STATUSTYPE_IMA: 1683 *result = '\0'; 1684 break; 1685 } 1686 1687 return; 1688 1689 err: 1690 DMEMIT("Error"); 1691 } 1692 1693 static int era_message(struct dm_target *ti, unsigned int argc, char **argv, 1694 char *result, unsigned int maxlen) 1695 { 1696 struct era *era = ti->private; 1697 1698 if (argc != 1) { 1699 DMERR("incorrect number of message arguments"); 1700 return -EINVAL; 1701 } 1702 1703 if (!strcasecmp(argv[0], "checkpoint")) 1704 return in_worker0(era, metadata_checkpoint); 1705 1706 if (!strcasecmp(argv[0], "take_metadata_snap")) 1707 return in_worker0(era, metadata_take_snap); 1708 1709 if (!strcasecmp(argv[0], "drop_metadata_snap")) 1710 return in_worker0(era, metadata_drop_snap); 1711 1712 DMERR("unsupported message '%s'", argv[0]); 1713 return -EINVAL; 1714 } 1715 1716 static sector_t get_dev_size(struct dm_dev *dev) 1717 { 1718 return bdev_nr_sectors(dev->bdev); 1719 } 1720 1721 static int era_iterate_devices(struct dm_target *ti, 1722 iterate_devices_callout_fn fn, void *data) 1723 { 1724 struct era *era = ti->private; 1725 1726 return fn(ti, era->origin_dev, 0, get_dev_size(era->origin_dev), data); 1727 } 1728 1729 static void era_io_hints(struct dm_target *ti, struct queue_limits *limits) 1730 { 1731 struct era *era = ti->private; 1732 uint64_t io_opt_sectors = limits->io_opt >> SECTOR_SHIFT; 1733 1734 /* 1735 * If the system-determined stacked limits are compatible with the 1736 * era device's blocksize (io_opt is a factor) do not override them. 1737 */ 1738 if (io_opt_sectors < era->sectors_per_block || 1739 do_div(io_opt_sectors, era->sectors_per_block)) { 1740 limits->io_min = 0; 1741 limits->io_opt = era->sectors_per_block << SECTOR_SHIFT; 1742 } 1743 } 1744 1745 /*----------------------------------------------------------------*/ 1746 1747 static struct target_type era_target = { 1748 .name = "era", 1749 .version = {1, 0, 0}, 1750 .module = THIS_MODULE, 1751 .ctr = era_ctr, 1752 .dtr = era_dtr, 1753 .map = era_map, 1754 .postsuspend = era_postsuspend, 1755 .preresume = era_preresume, 1756 .status = era_status, 1757 .message = era_message, 1758 .iterate_devices = era_iterate_devices, 1759 .io_hints = era_io_hints 1760 }; 1761 module_dm(era); 1762 1763 MODULE_DESCRIPTION(DM_NAME " era target"); 1764 MODULE_AUTHOR("Joe Thornber <ejt@redhat.com>"); 1765 MODULE_LICENSE("GPL"); 1766