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