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 */ 30struct writeset_metadata { 31 uint32_t nr_bits; 32 dm_block_t root; 33}; 34 35struct 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 */ 49static void writeset_free(struct writeset *ws) 50{ 51 vfree(ws->bits); 52 ws->bits = NULL; 53} 54 55static 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 67static 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 */ 75static 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 */ 89static 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 106static bool writeset_marked(struct writeset *ws, dm_block_t block) 107{ 108 return test_bit(block, ws->bits); 109} 110 111static 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 */ 136static 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 162struct writeset_disk { 163 __le32 nr_bits; 164 __le64 root; 165} __packed; 166 167struct 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 */ 199static void sb_prepare_for_write(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 211static 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 224static int sb_check(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 257static 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 271struct 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 311static 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 318static 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 325static 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 */ 333static 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 364static 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 370static 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 376static 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 390static 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 404static 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 411static 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 424static 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 437static 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 446static 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 473bad: 474 dm_sm_destroy(md->sm); 475 dm_tm_destroy(md->tm); 476 477 return r; 478} 479 480static 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 493static 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 */ 505static 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 527static 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 */ 552static 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 570static 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 616bad: 617 dm_bm_unlock(sblock); 618 return r; 619} 620 621static 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 637static 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 656static 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 */ 666static 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 */ 681struct 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 691static int metadata_digest_lookup_writeset(struct era_metadata *md, 692 struct digest *d); 693 694static 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 713static 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 747static 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 789static 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 */ 806static 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(sizeof(*md), GFP_KERNEL); 812 813 if (!md) 814 return NULL; 815 816 md->bdev = bdev; 817 md->block_size = block_size; 818 819 md->writesets[0].md.root = INVALID_WRITESET_ROOT; 820 md->writesets[1].md.root = INVALID_WRITESET_ROOT; 821 md->current_writeset = &md->writesets[0]; 822 823 r = create_persistent_data_objects(md, may_format); 824 if (r) { 825 kfree(md); 826 return ERR_PTR(r); 827 } 828 829 return md; 830} 831 832static void metadata_close(struct era_metadata *md) 833{ 834 writeset_free(&md->writesets[0]); 835 writeset_free(&md->writesets[1]); 836 destroy_persistent_data_objects(md); 837 kfree(md); 838} 839 840static bool valid_nr_blocks(dm_block_t n) 841{ 842 /* 843 * dm_bitset restricts us to 2^32. test_bit & co. restrict us 844 * further to 2^31 - 1 845 */ 846 return n < (1ull << 31); 847} 848 849static int metadata_resize(struct era_metadata *md, void *arg) 850{ 851 int r; 852 dm_block_t *new_size = arg; 853 __le32 value; 854 855 if (!valid_nr_blocks(*new_size)) { 856 DMERR("Invalid number of origin blocks %llu", 857 (unsigned long long) *new_size); 858 return -EINVAL; 859 } 860 861 writeset_free(&md->writesets[0]); 862 writeset_free(&md->writesets[1]); 863 864 r = writeset_alloc(&md->writesets[0], *new_size); 865 if (r) { 866 DMERR("%s: writeset_alloc failed for writeset 0", __func__); 867 return r; 868 } 869 870 r = writeset_alloc(&md->writesets[1], *new_size); 871 if (r) { 872 DMERR("%s: writeset_alloc failed for writeset 1", __func__); 873 writeset_free(&md->writesets[0]); 874 return r; 875 } 876 877 value = cpu_to_le32(0u); 878 __dm_bless_for_disk(&value); 879 r = dm_array_resize(&md->era_array_info, md->era_array_root, 880 md->nr_blocks, *new_size, 881 &value, &md->era_array_root); 882 if (r) { 883 DMERR("%s: dm_array_resize failed", __func__); 884 writeset_free(&md->writesets[0]); 885 writeset_free(&md->writesets[1]); 886 return r; 887 } 888 889 md->nr_blocks = *new_size; 890 return 0; 891} 892 893static int metadata_era_archive(struct era_metadata *md) 894{ 895 int r; 896 uint64_t keys[1]; 897 struct writeset_disk value; 898 899 r = dm_bitset_flush(&md->bitset_info, md->current_writeset->md.root, 900 &md->current_writeset->md.root); 901 if (r) { 902 DMERR("%s: dm_bitset_flush failed", __func__); 903 return r; 904 } 905 906 ws_pack(&md->current_writeset->md, &value); 907 908 keys[0] = md->current_era; 909 __dm_bless_for_disk(&value); 910 r = dm_btree_insert(&md->writeset_tree_info, md->writeset_tree_root, 911 keys, &value, &md->writeset_tree_root); 912 if (r) { 913 DMERR("%s: couldn't insert writeset into btree", __func__); 914 /* FIXME: fail mode */ 915 return r; 916 } 917 918 md->current_writeset->md.root = INVALID_WRITESET_ROOT; 919 md->archived_writesets = true; 920 921 return 0; 922} 923 924static struct writeset *next_writeset(struct era_metadata *md) 925{ 926 return (md->current_writeset == &md->writesets[0]) ? 927 &md->writesets[1] : &md->writesets[0]; 928} 929 930static int metadata_new_era(struct era_metadata *md) 931{ 932 int r; 933 struct writeset *new_writeset = next_writeset(md); 934 935 r = writeset_init(&md->bitset_info, new_writeset, md->nr_blocks); 936 if (r) { 937 DMERR("%s: writeset_init failed", __func__); 938 return r; 939 } 940 941 swap_writeset(md, new_writeset); 942 md->current_era++; 943 944 return 0; 945} 946 947static int metadata_era_rollover(struct era_metadata *md) 948{ 949 int r; 950 951 if (md->current_writeset->md.root != INVALID_WRITESET_ROOT) { 952 r = metadata_era_archive(md); 953 if (r) { 954 DMERR("%s: metadata_archive_era failed", __func__); 955 /* FIXME: fail mode? */ 956 return r; 957 } 958 } 959 960 r = metadata_new_era(md); 961 if (r) { 962 DMERR("%s: new era failed", __func__); 963 /* FIXME: fail mode */ 964 return r; 965 } 966 967 return 0; 968} 969 970static bool metadata_current_marked(struct era_metadata *md, dm_block_t block) 971{ 972 bool r; 973 struct writeset *ws; 974 975 rcu_read_lock(); 976 ws = rcu_dereference(md->current_writeset); 977 r = writeset_marked(ws, block); 978 rcu_read_unlock(); 979 980 return r; 981} 982 983static int metadata_commit(struct era_metadata *md) 984{ 985 int r; 986 struct dm_block *sblock; 987 988 if (md->current_writeset->md.root != INVALID_WRITESET_ROOT) { 989 r = dm_bitset_flush(&md->bitset_info, md->current_writeset->md.root, 990 &md->current_writeset->md.root); 991 if (r) { 992 DMERR("%s: bitset flush failed", __func__); 993 return r; 994 } 995 } 996 997 r = dm_tm_pre_commit(md->tm); 998 if (r) { 999 DMERR("%s: pre commit failed", __func__); 1000 return r; 1001 } 1002 1003 r = save_sm_root(md); 1004 if (r) { 1005 DMERR("%s: save_sm_root failed", __func__); 1006 return r; 1007 } 1008 1009 r = superblock_lock(md, &sblock); 1010 if (r) { 1011 DMERR("%s: superblock lock failed", __func__); 1012 return r; 1013 } 1014 1015 prepare_superblock(md, dm_block_data(sblock)); 1016 1017 return dm_tm_commit(md->tm, sblock); 1018} 1019 1020static int metadata_checkpoint(struct era_metadata *md) 1021{ 1022 /* 1023 * For now we just rollover, but later I want to put a check in to 1024 * avoid this if the filter is still pretty fresh. 1025 */ 1026 return metadata_era_rollover(md); 1027} 1028 1029/* 1030 * Metadata snapshots allow userland to access era data. 1031 */ 1032static int metadata_take_snap(struct era_metadata *md) 1033{ 1034 int r, inc; 1035 struct dm_block *clone; 1036 1037 if (md->metadata_snap != SUPERBLOCK_LOCATION) { 1038 DMERR("%s: metadata snapshot already exists", __func__); 1039 return -EINVAL; 1040 } 1041 1042 r = metadata_era_rollover(md); 1043 if (r) { 1044 DMERR("%s: era rollover failed", __func__); 1045 return r; 1046 } 1047 1048 r = metadata_commit(md); 1049 if (r) { 1050 DMERR("%s: pre commit failed", __func__); 1051 return r; 1052 } 1053 1054 r = dm_sm_inc_block(md->sm, SUPERBLOCK_LOCATION); 1055 if (r) { 1056 DMERR("%s: couldn't increment superblock", __func__); 1057 return r; 1058 } 1059 1060 r = dm_tm_shadow_block(md->tm, SUPERBLOCK_LOCATION, 1061 &sb_validator, &clone, &inc); 1062 if (r) { 1063 DMERR("%s: couldn't shadow superblock", __func__); 1064 dm_sm_dec_block(md->sm, SUPERBLOCK_LOCATION); 1065 return r; 1066 } 1067 BUG_ON(!inc); 1068 1069 r = dm_sm_inc_block(md->sm, md->writeset_tree_root); 1070 if (r) { 1071 DMERR("%s: couldn't inc writeset tree root", __func__); 1072 dm_tm_unlock(md->tm, clone); 1073 return r; 1074 } 1075 1076 r = dm_sm_inc_block(md->sm, md->era_array_root); 1077 if (r) { 1078 DMERR("%s: couldn't inc era tree root", __func__); 1079 dm_sm_dec_block(md->sm, md->writeset_tree_root); 1080 dm_tm_unlock(md->tm, clone); 1081 return r; 1082 } 1083 1084 md->metadata_snap = dm_block_location(clone); 1085 1086 dm_tm_unlock(md->tm, clone); 1087 1088 return 0; 1089} 1090 1091static int metadata_drop_snap(struct era_metadata *md) 1092{ 1093 int r; 1094 dm_block_t location; 1095 struct dm_block *clone; 1096 struct superblock_disk *disk; 1097 1098 if (md->metadata_snap == SUPERBLOCK_LOCATION) { 1099 DMERR("%s: no snap to drop", __func__); 1100 return -EINVAL; 1101 } 1102 1103 r = dm_tm_read_lock(md->tm, md->metadata_snap, &sb_validator, &clone); 1104 if (r) { 1105 DMERR("%s: couldn't read lock superblock clone", __func__); 1106 return r; 1107 } 1108 1109 /* 1110 * Whatever happens now we'll commit with no record of the metadata 1111 * snap. 1112 */ 1113 md->metadata_snap = SUPERBLOCK_LOCATION; 1114 1115 disk = dm_block_data(clone); 1116 r = dm_btree_del(&md->writeset_tree_info, 1117 le64_to_cpu(disk->writeset_tree_root)); 1118 if (r) { 1119 DMERR("%s: error deleting writeset tree clone", __func__); 1120 dm_tm_unlock(md->tm, clone); 1121 return r; 1122 } 1123 1124 r = dm_array_del(&md->era_array_info, le64_to_cpu(disk->era_array_root)); 1125 if (r) { 1126 DMERR("%s: error deleting era array clone", __func__); 1127 dm_tm_unlock(md->tm, clone); 1128 return r; 1129 } 1130 1131 location = dm_block_location(clone); 1132 dm_tm_unlock(md->tm, clone); 1133 1134 return dm_sm_dec_block(md->sm, location); 1135} 1136 1137struct metadata_stats { 1138 dm_block_t used; 1139 dm_block_t total; 1140 dm_block_t snap; 1141 uint32_t era; 1142}; 1143 1144static int metadata_get_stats(struct era_metadata *md, void *ptr) 1145{ 1146 int r; 1147 struct metadata_stats *s = ptr; 1148 dm_block_t nr_free, nr_total; 1149 1150 r = dm_sm_get_nr_free(md->sm, &nr_free); 1151 if (r) { 1152 DMERR("dm_sm_get_nr_free returned %d", r); 1153 return r; 1154 } 1155 1156 r = dm_sm_get_nr_blocks(md->sm, &nr_total); 1157 if (r) { 1158 DMERR("dm_pool_get_metadata_dev_size returned %d", r); 1159 return r; 1160 } 1161 1162 s->used = nr_total - nr_free; 1163 s->total = nr_total; 1164 s->snap = md->metadata_snap; 1165 s->era = md->current_era; 1166 1167 return 0; 1168} 1169 1170/*----------------------------------------------------------------*/ 1171 1172struct era { 1173 struct dm_target *ti; 1174 1175 struct dm_dev *metadata_dev; 1176 struct dm_dev *origin_dev; 1177 1178 dm_block_t nr_blocks; 1179 uint32_t sectors_per_block; 1180 int sectors_per_block_shift; 1181 struct era_metadata *md; 1182 1183 struct workqueue_struct *wq; 1184 struct work_struct worker; 1185 1186 spinlock_t deferred_lock; 1187 struct bio_list deferred_bios; 1188 1189 spinlock_t rpc_lock; 1190 struct list_head rpc_calls; 1191 1192 struct digest digest; 1193 atomic_t suspended; 1194}; 1195 1196struct rpc { 1197 struct list_head list; 1198 1199 int (*fn0)(struct era_metadata *md); 1200 int (*fn1)(struct era_metadata *md, void *ref); 1201 void *arg; 1202 int result; 1203 1204 struct completion complete; 1205}; 1206 1207/* 1208 *--------------------------------------------------------------- 1209 * Remapping. 1210 *--------------------------------------------------------------- 1211 */ 1212static bool block_size_is_power_of_two(struct era *era) 1213{ 1214 return era->sectors_per_block_shift >= 0; 1215} 1216 1217static dm_block_t get_block(struct era *era, struct bio *bio) 1218{ 1219 sector_t block_nr = bio->bi_iter.bi_sector; 1220 1221 if (!block_size_is_power_of_two(era)) 1222 (void) sector_div(block_nr, era->sectors_per_block); 1223 else 1224 block_nr >>= era->sectors_per_block_shift; 1225 1226 return block_nr; 1227} 1228 1229static void remap_to_origin(struct era *era, struct bio *bio) 1230{ 1231 bio_set_dev(bio, era->origin_dev->bdev); 1232} 1233 1234/* 1235 *-------------------------------------------------------------- 1236 * Worker thread 1237 *-------------------------------------------------------------- 1238 */ 1239static void wake_worker(struct era *era) 1240{ 1241 if (!atomic_read(&era->suspended)) 1242 queue_work(era->wq, &era->worker); 1243} 1244 1245static void process_old_eras(struct era *era) 1246{ 1247 int r; 1248 1249 if (!era->digest.step) 1250 return; 1251 1252 r = era->digest.step(era->md, &era->digest); 1253 if (r < 0) { 1254 DMERR("%s: digest step failed, stopping digestion", __func__); 1255 era->digest.step = NULL; 1256 1257 } else if (era->digest.step) 1258 wake_worker(era); 1259} 1260 1261static void process_deferred_bios(struct era *era) 1262{ 1263 int r; 1264 struct bio_list deferred_bios, marked_bios; 1265 struct bio *bio; 1266 struct blk_plug plug; 1267 bool commit_needed = false; 1268 bool failed = false; 1269 struct writeset *ws = era->md->current_writeset; 1270 1271 bio_list_init(&deferred_bios); 1272 bio_list_init(&marked_bios); 1273 1274 spin_lock(&era->deferred_lock); 1275 bio_list_merge(&deferred_bios, &era->deferred_bios); 1276 bio_list_init(&era->deferred_bios); 1277 spin_unlock(&era->deferred_lock); 1278 1279 if (bio_list_empty(&deferred_bios)) 1280 return; 1281 1282 while ((bio = bio_list_pop(&deferred_bios))) { 1283 r = writeset_test_and_set(&era->md->bitset_info, ws, 1284 get_block(era, bio)); 1285 if (r < 0) { 1286 /* 1287 * This is bad news, we need to rollback. 1288 * FIXME: finish. 1289 */ 1290 failed = true; 1291 } else if (r == 0) 1292 commit_needed = true; 1293 1294 bio_list_add(&marked_bios, bio); 1295 } 1296 1297 if (commit_needed) { 1298 r = metadata_commit(era->md); 1299 if (r) 1300 failed = true; 1301 } 1302 1303 if (failed) 1304 while ((bio = bio_list_pop(&marked_bios))) 1305 bio_io_error(bio); 1306 else { 1307 blk_start_plug(&plug); 1308 while ((bio = bio_list_pop(&marked_bios))) { 1309 /* 1310 * Only update the in-core writeset if the on-disk one 1311 * was updated too. 1312 */ 1313 if (commit_needed) 1314 set_bit(get_block(era, bio), ws->bits); 1315 submit_bio_noacct(bio); 1316 } 1317 blk_finish_plug(&plug); 1318 } 1319} 1320 1321static void process_rpc_calls(struct era *era) 1322{ 1323 int r; 1324 bool need_commit = false; 1325 struct list_head calls; 1326 struct rpc *rpc, *tmp; 1327 1328 INIT_LIST_HEAD(&calls); 1329 spin_lock(&era->rpc_lock); 1330 list_splice_init(&era->rpc_calls, &calls); 1331 spin_unlock(&era->rpc_lock); 1332 1333 list_for_each_entry_safe(rpc, tmp, &calls, list) { 1334 rpc->result = rpc->fn0 ? rpc->fn0(era->md) : rpc->fn1(era->md, rpc->arg); 1335 need_commit = true; 1336 } 1337 1338 if (need_commit) { 1339 r = metadata_commit(era->md); 1340 if (r) 1341 list_for_each_entry_safe(rpc, tmp, &calls, list) 1342 rpc->result = r; 1343 } 1344 1345 list_for_each_entry_safe(rpc, tmp, &calls, list) 1346 complete(&rpc->complete); 1347} 1348 1349static void kick_off_digest(struct era *era) 1350{ 1351 if (era->md->archived_writesets) { 1352 era->md->archived_writesets = false; 1353 metadata_digest_start(era->md, &era->digest); 1354 } 1355} 1356 1357static void do_work(struct work_struct *ws) 1358{ 1359 struct era *era = container_of(ws, struct era, worker); 1360 1361 kick_off_digest(era); 1362 process_old_eras(era); 1363 process_deferred_bios(era); 1364 process_rpc_calls(era); 1365} 1366 1367static void defer_bio(struct era *era, struct bio *bio) 1368{ 1369 spin_lock(&era->deferred_lock); 1370 bio_list_add(&era->deferred_bios, bio); 1371 spin_unlock(&era->deferred_lock); 1372 1373 wake_worker(era); 1374} 1375 1376/* 1377 * Make an rpc call to the worker to change the metadata. 1378 */ 1379static int perform_rpc(struct era *era, struct rpc *rpc) 1380{ 1381 rpc->result = 0; 1382 init_completion(&rpc->complete); 1383 1384 spin_lock(&era->rpc_lock); 1385 list_add(&rpc->list, &era->rpc_calls); 1386 spin_unlock(&era->rpc_lock); 1387 1388 wake_worker(era); 1389 wait_for_completion(&rpc->complete); 1390 1391 return rpc->result; 1392} 1393 1394static int in_worker0(struct era *era, int (*fn)(struct era_metadata *md)) 1395{ 1396 struct rpc rpc; 1397 1398 rpc.fn0 = fn; 1399 rpc.fn1 = NULL; 1400 1401 return perform_rpc(era, &rpc); 1402} 1403 1404static int in_worker1(struct era *era, 1405 int (*fn)(struct era_metadata *md, void *ref), void *arg) 1406{ 1407 struct rpc rpc; 1408 1409 rpc.fn0 = NULL; 1410 rpc.fn1 = fn; 1411 rpc.arg = arg; 1412 1413 return perform_rpc(era, &rpc); 1414} 1415 1416static void start_worker(struct era *era) 1417{ 1418 atomic_set(&era->suspended, 0); 1419} 1420 1421static void stop_worker(struct era *era) 1422{ 1423 atomic_set(&era->suspended, 1); 1424 drain_workqueue(era->wq); 1425} 1426 1427/* 1428 *-------------------------------------------------------------- 1429 * Target methods 1430 *-------------------------------------------------------------- 1431 */ 1432static void era_destroy(struct era *era) 1433{ 1434 if (era->md) 1435 metadata_close(era->md); 1436 1437 if (era->wq) 1438 destroy_workqueue(era->wq); 1439 1440 if (era->origin_dev) 1441 dm_put_device(era->ti, era->origin_dev); 1442 1443 if (era->metadata_dev) 1444 dm_put_device(era->ti, era->metadata_dev); 1445 1446 kfree(era); 1447} 1448 1449static dm_block_t calc_nr_blocks(struct era *era) 1450{ 1451 return dm_sector_div_up(era->ti->len, era->sectors_per_block); 1452} 1453 1454static bool valid_block_size(dm_block_t block_size) 1455{ 1456 bool greater_than_zero = block_size > 0; 1457 bool multiple_of_min_block_size = (block_size & (MIN_BLOCK_SIZE - 1)) == 0; 1458 1459 return greater_than_zero && multiple_of_min_block_size; 1460} 1461 1462/* 1463 * <metadata dev> <data dev> <data block size (sectors)> 1464 */ 1465static int era_ctr(struct dm_target *ti, unsigned int argc, char **argv) 1466{ 1467 int r; 1468 char dummy; 1469 struct era *era; 1470 struct era_metadata *md; 1471 1472 if (argc != 3) { 1473 ti->error = "Invalid argument count"; 1474 return -EINVAL; 1475 } 1476 1477 era = kzalloc(sizeof(*era), GFP_KERNEL); 1478 if (!era) { 1479 ti->error = "Error allocating era structure"; 1480 return -ENOMEM; 1481 } 1482 1483 era->ti = ti; 1484 1485 r = dm_get_device(ti, argv[0], BLK_OPEN_READ | BLK_OPEN_WRITE, 1486 &era->metadata_dev); 1487 if (r) { 1488 ti->error = "Error opening metadata device"; 1489 era_destroy(era); 1490 return -EINVAL; 1491 } 1492 1493 r = dm_get_device(ti, argv[1], BLK_OPEN_READ | BLK_OPEN_WRITE, 1494 &era->origin_dev); 1495 if (r) { 1496 ti->error = "Error opening data device"; 1497 era_destroy(era); 1498 return -EINVAL; 1499 } 1500 1501 r = sscanf(argv[2], "%u%c", &era->sectors_per_block, &dummy); 1502 if (r != 1) { 1503 ti->error = "Error parsing block size"; 1504 era_destroy(era); 1505 return -EINVAL; 1506 } 1507 1508 r = dm_set_target_max_io_len(ti, era->sectors_per_block); 1509 if (r) { 1510 ti->error = "could not set max io len"; 1511 era_destroy(era); 1512 return -EINVAL; 1513 } 1514 1515 if (!valid_block_size(era->sectors_per_block)) { 1516 ti->error = "Invalid block size"; 1517 era_destroy(era); 1518 return -EINVAL; 1519 } 1520 if (era->sectors_per_block & (era->sectors_per_block - 1)) 1521 era->sectors_per_block_shift = -1; 1522 else 1523 era->sectors_per_block_shift = __ffs(era->sectors_per_block); 1524 1525 md = metadata_open(era->metadata_dev->bdev, era->sectors_per_block, true); 1526 if (IS_ERR(md)) { 1527 ti->error = "Error reading metadata"; 1528 era_destroy(era); 1529 return PTR_ERR(md); 1530 } 1531 era->md = md; 1532 1533 era->wq = alloc_ordered_workqueue("dm-" DM_MSG_PREFIX, WQ_MEM_RECLAIM); 1534 if (!era->wq) { 1535 ti->error = "could not create workqueue for metadata object"; 1536 era_destroy(era); 1537 return -ENOMEM; 1538 } 1539 INIT_WORK(&era->worker, do_work); 1540 1541 spin_lock_init(&era->deferred_lock); 1542 bio_list_init(&era->deferred_bios); 1543 1544 spin_lock_init(&era->rpc_lock); 1545 INIT_LIST_HEAD(&era->rpc_calls); 1546 1547 ti->private = era; 1548 ti->num_flush_bios = 1; 1549 ti->flush_supported = true; 1550 1551 ti->num_discard_bios = 1; 1552 1553 return 0; 1554} 1555 1556static void era_dtr(struct dm_target *ti) 1557{ 1558 era_destroy(ti->private); 1559} 1560 1561static int era_map(struct dm_target *ti, struct bio *bio) 1562{ 1563 struct era *era = ti->private; 1564 dm_block_t block = get_block(era, bio); 1565 1566 /* 1567 * All bios get remapped to the origin device. We do this now, but 1568 * it may not get issued until later. Depending on whether the 1569 * block is marked in this era. 1570 */ 1571 remap_to_origin(era, bio); 1572 1573 /* 1574 * REQ_PREFLUSH bios carry no data, so we're not interested in them. 1575 */ 1576 if (!(bio->bi_opf & REQ_PREFLUSH) && 1577 (bio_data_dir(bio) == WRITE) && 1578 !metadata_current_marked(era->md, block)) { 1579 defer_bio(era, bio); 1580 return DM_MAPIO_SUBMITTED; 1581 } 1582 1583 return DM_MAPIO_REMAPPED; 1584} 1585 1586static void era_postsuspend(struct dm_target *ti) 1587{ 1588 int r; 1589 struct era *era = ti->private; 1590 1591 r = in_worker0(era, metadata_era_archive); 1592 if (r) { 1593 DMERR("%s: couldn't archive current era", __func__); 1594 /* FIXME: fail mode */ 1595 } 1596 1597 stop_worker(era); 1598 1599 r = metadata_commit(era->md); 1600 if (r) { 1601 DMERR("%s: metadata_commit failed", __func__); 1602 /* FIXME: fail mode */ 1603 } 1604} 1605 1606static int era_preresume(struct dm_target *ti) 1607{ 1608 int r; 1609 struct era *era = ti->private; 1610 dm_block_t new_size = calc_nr_blocks(era); 1611 1612 if (era->nr_blocks != new_size) { 1613 r = metadata_resize(era->md, &new_size); 1614 if (r) { 1615 DMERR("%s: metadata_resize failed", __func__); 1616 return r; 1617 } 1618 1619 r = metadata_commit(era->md); 1620 if (r) { 1621 DMERR("%s: metadata_commit failed", __func__); 1622 return r; 1623 } 1624 1625 era->nr_blocks = new_size; 1626 } 1627 1628 start_worker(era); 1629 1630 r = in_worker0(era, metadata_era_rollover); 1631 if (r) { 1632 DMERR("%s: metadata_era_rollover failed", __func__); 1633 return r; 1634 } 1635 1636 return 0; 1637} 1638 1639/* 1640 * Status format: 1641 * 1642 * <metadata block size> <#used metadata blocks>/<#total metadata blocks> 1643 * <current era> <held metadata root | '-'> 1644 */ 1645static void era_status(struct dm_target *ti, status_type_t type, 1646 unsigned int status_flags, char *result, unsigned int maxlen) 1647{ 1648 int r; 1649 struct era *era = ti->private; 1650 ssize_t sz = 0; 1651 struct metadata_stats stats; 1652 char buf[BDEVNAME_SIZE]; 1653 1654 switch (type) { 1655 case STATUSTYPE_INFO: 1656 r = in_worker1(era, metadata_get_stats, &stats); 1657 if (r) 1658 goto err; 1659 1660 DMEMIT("%u %llu/%llu %u", 1661 (unsigned int) (DM_ERA_METADATA_BLOCK_SIZE >> SECTOR_SHIFT), 1662 (unsigned long long) stats.used, 1663 (unsigned long long) stats.total, 1664 (unsigned int) stats.era); 1665 1666 if (stats.snap != SUPERBLOCK_LOCATION) 1667 DMEMIT(" %llu", stats.snap); 1668 else 1669 DMEMIT(" -"); 1670 break; 1671 1672 case STATUSTYPE_TABLE: 1673 format_dev_t(buf, era->metadata_dev->bdev->bd_dev); 1674 DMEMIT("%s ", buf); 1675 format_dev_t(buf, era->origin_dev->bdev->bd_dev); 1676 DMEMIT("%s %u", buf, era->sectors_per_block); 1677 break; 1678 1679 case STATUSTYPE_IMA: 1680 *result = '\0'; 1681 break; 1682 } 1683 1684 return; 1685 1686err: 1687 DMEMIT("Error"); 1688} 1689 1690static int era_message(struct dm_target *ti, unsigned int argc, char **argv, 1691 char *result, unsigned int maxlen) 1692{ 1693 struct era *era = ti->private; 1694 1695 if (argc != 1) { 1696 DMERR("incorrect number of message arguments"); 1697 return -EINVAL; 1698 } 1699 1700 if (!strcasecmp(argv[0], "checkpoint")) 1701 return in_worker0(era, metadata_checkpoint); 1702 1703 if (!strcasecmp(argv[0], "take_metadata_snap")) 1704 return in_worker0(era, metadata_take_snap); 1705 1706 if (!strcasecmp(argv[0], "drop_metadata_snap")) 1707 return in_worker0(era, metadata_drop_snap); 1708 1709 DMERR("unsupported message '%s'", argv[0]); 1710 return -EINVAL; 1711} 1712 1713static sector_t get_dev_size(struct dm_dev *dev) 1714{ 1715 return bdev_nr_sectors(dev->bdev); 1716} 1717 1718static int era_iterate_devices(struct dm_target *ti, 1719 iterate_devices_callout_fn fn, void *data) 1720{ 1721 struct era *era = ti->private; 1722 1723 return fn(ti, era->origin_dev, 0, get_dev_size(era->origin_dev), data); 1724} 1725 1726static void era_io_hints(struct dm_target *ti, struct queue_limits *limits) 1727{ 1728 struct era *era = ti->private; 1729 uint64_t io_opt_sectors = limits->io_opt >> SECTOR_SHIFT; 1730 1731 /* 1732 * If the system-determined stacked limits are compatible with the 1733 * era device's blocksize (io_opt is a factor) do not override them. 1734 */ 1735 if (io_opt_sectors < era->sectors_per_block || 1736 do_div(io_opt_sectors, era->sectors_per_block)) { 1737 blk_limits_io_min(limits, 0); 1738 blk_limits_io_opt(limits, era->sectors_per_block << SECTOR_SHIFT); 1739 } 1740} 1741 1742/*----------------------------------------------------------------*/ 1743 1744static struct target_type era_target = { 1745 .name = "era", 1746 .version = {1, 0, 0}, 1747 .module = THIS_MODULE, 1748 .ctr = era_ctr, 1749 .dtr = era_dtr, 1750 .map = era_map, 1751 .postsuspend = era_postsuspend, 1752 .preresume = era_preresume, 1753 .status = era_status, 1754 .message = era_message, 1755 .iterate_devices = era_iterate_devices, 1756 .io_hints = era_io_hints 1757}; 1758module_dm(era); 1759 1760MODULE_DESCRIPTION(DM_NAME " era target"); 1761MODULE_AUTHOR("Joe Thornber <ejt@redhat.com>"); 1762MODULE_LICENSE("GPL"); 1763