linux/drivers/md/dm-thin-metadata.c
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   1/*
   2 * Copyright (C) 2011-2012 Red Hat, Inc.
   3 *
   4 * This file is released under the GPL.
   5 */
   6
   7#include "dm-thin-metadata.h"
   8#include "persistent-data/dm-btree.h"
   9#include "persistent-data/dm-space-map.h"
  10#include "persistent-data/dm-space-map-disk.h"
  11#include "persistent-data/dm-transaction-manager.h"
  12
  13#include <linux/list.h>
  14#include <linux/device-mapper.h>
  15#include <linux/workqueue.h>
  16
  17/*--------------------------------------------------------------------------
  18 * As far as the metadata goes, there is:
  19 *
  20 * - A superblock in block zero, taking up fewer than 512 bytes for
  21 *   atomic writes.
  22 *
  23 * - A space map managing the metadata blocks.
  24 *
  25 * - A space map managing the data blocks.
  26 *
  27 * - A btree mapping our internal thin dev ids onto struct disk_device_details.
  28 *
  29 * - A hierarchical btree, with 2 levels which effectively maps (thin
  30 *   dev id, virtual block) -> block_time.  Block time is a 64-bit
  31 *   field holding the time in the low 24 bits, and block in the top 48
  32 *   bits.
  33 *
  34 * BTrees consist solely of btree_nodes, that fill a block.  Some are
  35 * internal nodes, as such their values are a __le64 pointing to other
  36 * nodes.  Leaf nodes can store data of any reasonable size (ie. much
  37 * smaller than the block size).  The nodes consist of the header,
  38 * followed by an array of keys, followed by an array of values.  We have
  39 * to binary search on the keys so they're all held together to help the
  40 * cpu cache.
  41 *
  42 * Space maps have 2 btrees:
  43 *
  44 * - One maps a uint64_t onto a struct index_entry.  Which points to a
  45 *   bitmap block, and has some details about how many free entries there
  46 *   are etc.
  47 *
  48 * - The bitmap blocks have a header (for the checksum).  Then the rest
  49 *   of the block is pairs of bits.  With the meaning being:
  50 *
  51 *   0 - ref count is 0
  52 *   1 - ref count is 1
  53 *   2 - ref count is 2
  54 *   3 - ref count is higher than 2
  55 *
  56 * - If the count is higher than 2 then the ref count is entered in a
  57 *   second btree that directly maps the block_address to a uint32_t ref
  58 *   count.
  59 *
  60 * The space map metadata variant doesn't have a bitmaps btree.  Instead
  61 * it has one single blocks worth of index_entries.  This avoids
  62 * recursive issues with the bitmap btree needing to allocate space in
  63 * order to insert.  With a small data block size such as 64k the
  64 * metadata support data devices that are hundreds of terrabytes.
  65 *
  66 * The space maps allocate space linearly from front to back.  Space that
  67 * is freed in a transaction is never recycled within that transaction.
  68 * To try and avoid fragmenting _free_ space the allocator always goes
  69 * back and fills in gaps.
  70 *
  71 * All metadata io is in THIN_METADATA_BLOCK_SIZE sized/aligned chunks
  72 * from the block manager.
  73 *--------------------------------------------------------------------------*/
  74
  75#define DM_MSG_PREFIX   "thin metadata"
  76
  77#define THIN_SUPERBLOCK_MAGIC 27022010
  78#define THIN_SUPERBLOCK_LOCATION 0
  79#define THIN_VERSION 1
  80#define THIN_METADATA_CACHE_SIZE 64
  81#define SECTOR_TO_BLOCK_SHIFT 3
  82
  83/*
  84 *  3 for btree insert +
  85 *  2 for btree lookup used within space map
  86 */
  87#define THIN_MAX_CONCURRENT_LOCKS 5
  88
  89/* This should be plenty */
  90#define SPACE_MAP_ROOT_SIZE 128
  91
  92/*
  93 * Little endian on-disk superblock and device details.
  94 */
  95struct thin_disk_superblock {
  96        __le32 csum;    /* Checksum of superblock except for this field. */
  97        __le32 flags;
  98        __le64 blocknr; /* This block number, dm_block_t. */
  99
 100        __u8 uuid[16];
 101        __le64 magic;
 102        __le32 version;
 103        __le32 time;
 104
 105        __le64 trans_id;
 106
 107        /*
 108         * Root held by userspace transactions.
 109         */
 110        __le64 held_root;
 111
 112        __u8 data_space_map_root[SPACE_MAP_ROOT_SIZE];
 113        __u8 metadata_space_map_root[SPACE_MAP_ROOT_SIZE];
 114
 115        /*
 116         * 2-level btree mapping (dev_id, (dev block, time)) -> data block
 117         */
 118        __le64 data_mapping_root;
 119
 120        /*
 121         * Device detail root mapping dev_id -> device_details
 122         */
 123        __le64 device_details_root;
 124
 125        __le32 data_block_size;         /* In 512-byte sectors. */
 126
 127        __le32 metadata_block_size;     /* In 512-byte sectors. */
 128        __le64 metadata_nr_blocks;
 129
 130        __le32 compat_flags;
 131        __le32 compat_ro_flags;
 132        __le32 incompat_flags;
 133} __packed;
 134
 135struct disk_device_details {
 136        __le64 mapped_blocks;
 137        __le64 transaction_id;          /* When created. */
 138        __le32 creation_time;
 139        __le32 snapshotted_time;
 140} __packed;
 141
 142struct dm_pool_metadata {
 143        struct hlist_node hash;
 144
 145        struct block_device *bdev;
 146        struct dm_block_manager *bm;
 147        struct dm_space_map *metadata_sm;
 148        struct dm_space_map *data_sm;
 149        struct dm_transaction_manager *tm;
 150        struct dm_transaction_manager *nb_tm;
 151
 152        /*
 153         * Two-level btree.
 154         * First level holds thin_dev_t.
 155         * Second level holds mappings.
 156         */
 157        struct dm_btree_info info;
 158
 159        /*
 160         * Non-blocking version of the above.
 161         */
 162        struct dm_btree_info nb_info;
 163
 164        /*
 165         * Just the top level for deleting whole devices.
 166         */
 167        struct dm_btree_info tl_info;
 168
 169        /*
 170         * Just the bottom level for creating new devices.
 171         */
 172        struct dm_btree_info bl_info;
 173
 174        /*
 175         * Describes the device details btree.
 176         */
 177        struct dm_btree_info details_info;
 178
 179        struct rw_semaphore root_lock;
 180        uint32_t time;
 181        dm_block_t root;
 182        dm_block_t details_root;
 183        struct list_head thin_devices;
 184        uint64_t trans_id;
 185        unsigned long flags;
 186        sector_t data_block_size;
 187        bool read_only:1;
 188
 189        /*
 190         * Set if a transaction has to be aborted but the attempt to roll back
 191         * to the previous (good) transaction failed.  The only pool metadata
 192         * operation possible in this state is the closing of the device.
 193         */
 194        bool fail_io:1;
 195};
 196
 197struct dm_thin_device {
 198        struct list_head list;
 199        struct dm_pool_metadata *pmd;
 200        dm_thin_id id;
 201
 202        int open_count;
 203        bool changed:1;
 204        bool aborted_with_changes:1;
 205        uint64_t mapped_blocks;
 206        uint64_t transaction_id;
 207        uint32_t creation_time;
 208        uint32_t snapshotted_time;
 209};
 210
 211/*----------------------------------------------------------------
 212 * superblock validator
 213 *--------------------------------------------------------------*/
 214
 215#define SUPERBLOCK_CSUM_XOR 160774
 216
 217static void sb_prepare_for_write(struct dm_block_validator *v,
 218                                 struct dm_block *b,
 219                                 size_t block_size)
 220{
 221        struct thin_disk_superblock *disk_super = dm_block_data(b);
 222
 223        disk_super->blocknr = cpu_to_le64(dm_block_location(b));
 224        disk_super->csum = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
 225                                                      block_size - sizeof(__le32),
 226                                                      SUPERBLOCK_CSUM_XOR));
 227}
 228
 229static int sb_check(struct dm_block_validator *v,
 230                    struct dm_block *b,
 231                    size_t block_size)
 232{
 233        struct thin_disk_superblock *disk_super = dm_block_data(b);
 234        __le32 csum_le;
 235
 236        if (dm_block_location(b) != le64_to_cpu(disk_super->blocknr)) {
 237                DMERR("sb_check failed: blocknr %llu: "
 238                      "wanted %llu", le64_to_cpu(disk_super->blocknr),
 239                      (unsigned long long)dm_block_location(b));
 240                return -ENOTBLK;
 241        }
 242
 243        if (le64_to_cpu(disk_super->magic) != THIN_SUPERBLOCK_MAGIC) {
 244                DMERR("sb_check failed: magic %llu: "
 245                      "wanted %llu", le64_to_cpu(disk_super->magic),
 246                      (unsigned long long)THIN_SUPERBLOCK_MAGIC);
 247                return -EILSEQ;
 248        }
 249
 250        csum_le = cpu_to_le32(dm_bm_checksum(&disk_super->flags,
 251                                             block_size - sizeof(__le32),
 252                                             SUPERBLOCK_CSUM_XOR));
 253        if (csum_le != disk_super->csum) {
 254                DMERR("sb_check failed: csum %u: wanted %u",
 255                      le32_to_cpu(csum_le), le32_to_cpu(disk_super->csum));
 256                return -EILSEQ;
 257        }
 258
 259        return 0;
 260}
 261
 262static struct dm_block_validator sb_validator = {
 263        .name = "superblock",
 264        .prepare_for_write = sb_prepare_for_write,
 265        .check = sb_check
 266};
 267
 268/*----------------------------------------------------------------
 269 * Methods for the btree value types
 270 *--------------------------------------------------------------*/
 271
 272static uint64_t pack_block_time(dm_block_t b, uint32_t t)
 273{
 274        return (b << 24) | t;
 275}
 276
 277static void unpack_block_time(uint64_t v, dm_block_t *b, uint32_t *t)
 278{
 279        *b = v >> 24;
 280        *t = v & ((1 << 24) - 1);
 281}
 282
 283static void data_block_inc(void *context, const void *value_le)
 284{
 285        struct dm_space_map *sm = context;
 286        __le64 v_le;
 287        uint64_t b;
 288        uint32_t t;
 289
 290        memcpy(&v_le, value_le, sizeof(v_le));
 291        unpack_block_time(le64_to_cpu(v_le), &b, &t);
 292        dm_sm_inc_block(sm, b);
 293}
 294
 295static void data_block_dec(void *context, const void *value_le)
 296{
 297        struct dm_space_map *sm = context;
 298        __le64 v_le;
 299        uint64_t b;
 300        uint32_t t;
 301
 302        memcpy(&v_le, value_le, sizeof(v_le));
 303        unpack_block_time(le64_to_cpu(v_le), &b, &t);
 304        dm_sm_dec_block(sm, b);
 305}
 306
 307static int data_block_equal(void *context, const void *value1_le, const void *value2_le)
 308{
 309        __le64 v1_le, v2_le;
 310        uint64_t b1, b2;
 311        uint32_t t;
 312
 313        memcpy(&v1_le, value1_le, sizeof(v1_le));
 314        memcpy(&v2_le, value2_le, sizeof(v2_le));
 315        unpack_block_time(le64_to_cpu(v1_le), &b1, &t);
 316        unpack_block_time(le64_to_cpu(v2_le), &b2, &t);
 317
 318        return b1 == b2;
 319}
 320
 321static void subtree_inc(void *context, const void *value)
 322{
 323        struct dm_btree_info *info = context;
 324        __le64 root_le;
 325        uint64_t root;
 326
 327        memcpy(&root_le, value, sizeof(root_le));
 328        root = le64_to_cpu(root_le);
 329        dm_tm_inc(info->tm, root);
 330}
 331
 332static void subtree_dec(void *context, const void *value)
 333{
 334        struct dm_btree_info *info = context;
 335        __le64 root_le;
 336        uint64_t root;
 337
 338        memcpy(&root_le, value, sizeof(root_le));
 339        root = le64_to_cpu(root_le);
 340        if (dm_btree_del(info, root))
 341                DMERR("btree delete failed\n");
 342}
 343
 344static int subtree_equal(void *context, const void *value1_le, const void *value2_le)
 345{
 346        __le64 v1_le, v2_le;
 347        memcpy(&v1_le, value1_le, sizeof(v1_le));
 348        memcpy(&v2_le, value2_le, sizeof(v2_le));
 349
 350        return v1_le == v2_le;
 351}
 352
 353/*----------------------------------------------------------------*/
 354
 355static int superblock_lock_zero(struct dm_pool_metadata *pmd,
 356                                struct dm_block **sblock)
 357{
 358        return dm_bm_write_lock_zero(pmd->bm, THIN_SUPERBLOCK_LOCATION,
 359                                     &sb_validator, sblock);
 360}
 361
 362static int superblock_lock(struct dm_pool_metadata *pmd,
 363                           struct dm_block **sblock)
 364{
 365        return dm_bm_write_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
 366                                &sb_validator, sblock);
 367}
 368
 369static int __superblock_all_zeroes(struct dm_block_manager *bm, int *result)
 370{
 371        int r;
 372        unsigned i;
 373        struct dm_block *b;
 374        __le64 *data_le, zero = cpu_to_le64(0);
 375        unsigned block_size = dm_bm_block_size(bm) / sizeof(__le64);
 376
 377        /*
 378         * We can't use a validator here - it may be all zeroes.
 379         */
 380        r = dm_bm_read_lock(bm, THIN_SUPERBLOCK_LOCATION, NULL, &b);
 381        if (r)
 382                return r;
 383
 384        data_le = dm_block_data(b);
 385        *result = 1;
 386        for (i = 0; i < block_size; i++) {
 387                if (data_le[i] != zero) {
 388                        *result = 0;
 389                        break;
 390                }
 391        }
 392
 393        return dm_bm_unlock(b);
 394}
 395
 396static void __setup_btree_details(struct dm_pool_metadata *pmd)
 397{
 398        pmd->info.tm = pmd->tm;
 399        pmd->info.levels = 2;
 400        pmd->info.value_type.context = pmd->data_sm;
 401        pmd->info.value_type.size = sizeof(__le64);
 402        pmd->info.value_type.inc = data_block_inc;
 403        pmd->info.value_type.dec = data_block_dec;
 404        pmd->info.value_type.equal = data_block_equal;
 405
 406        memcpy(&pmd->nb_info, &pmd->info, sizeof(pmd->nb_info));
 407        pmd->nb_info.tm = pmd->nb_tm;
 408
 409        pmd->tl_info.tm = pmd->tm;
 410        pmd->tl_info.levels = 1;
 411        pmd->tl_info.value_type.context = &pmd->bl_info;
 412        pmd->tl_info.value_type.size = sizeof(__le64);
 413        pmd->tl_info.value_type.inc = subtree_inc;
 414        pmd->tl_info.value_type.dec = subtree_dec;
 415        pmd->tl_info.value_type.equal = subtree_equal;
 416
 417        pmd->bl_info.tm = pmd->tm;
 418        pmd->bl_info.levels = 1;
 419        pmd->bl_info.value_type.context = pmd->data_sm;
 420        pmd->bl_info.value_type.size = sizeof(__le64);
 421        pmd->bl_info.value_type.inc = data_block_inc;
 422        pmd->bl_info.value_type.dec = data_block_dec;
 423        pmd->bl_info.value_type.equal = data_block_equal;
 424
 425        pmd->details_info.tm = pmd->tm;
 426        pmd->details_info.levels = 1;
 427        pmd->details_info.value_type.context = NULL;
 428        pmd->details_info.value_type.size = sizeof(struct disk_device_details);
 429        pmd->details_info.value_type.inc = NULL;
 430        pmd->details_info.value_type.dec = NULL;
 431        pmd->details_info.value_type.equal = NULL;
 432}
 433
 434static int __write_initial_superblock(struct dm_pool_metadata *pmd)
 435{
 436        int r;
 437        struct dm_block *sblock;
 438        size_t metadata_len, data_len;
 439        struct thin_disk_superblock *disk_super;
 440        sector_t bdev_size = i_size_read(pmd->bdev->bd_inode) >> SECTOR_SHIFT;
 441
 442        if (bdev_size > THIN_METADATA_MAX_SECTORS)
 443                bdev_size = THIN_METADATA_MAX_SECTORS;
 444
 445        r = dm_sm_root_size(pmd->metadata_sm, &metadata_len);
 446        if (r < 0)
 447                return r;
 448
 449        r = dm_sm_root_size(pmd->data_sm, &data_len);
 450        if (r < 0)
 451                return r;
 452
 453        r = dm_sm_commit(pmd->data_sm);
 454        if (r < 0)
 455                return r;
 456
 457        r = dm_tm_pre_commit(pmd->tm);
 458        if (r < 0)
 459                return r;
 460
 461        r = superblock_lock_zero(pmd, &sblock);
 462        if (r)
 463                return r;
 464
 465        disk_super = dm_block_data(sblock);
 466        disk_super->flags = 0;
 467        memset(disk_super->uuid, 0, sizeof(disk_super->uuid));
 468        disk_super->magic = cpu_to_le64(THIN_SUPERBLOCK_MAGIC);
 469        disk_super->version = cpu_to_le32(THIN_VERSION);
 470        disk_super->time = 0;
 471        disk_super->trans_id = 0;
 472        disk_super->held_root = 0;
 473
 474        r = dm_sm_copy_root(pmd->metadata_sm, &disk_super->metadata_space_map_root,
 475                            metadata_len);
 476        if (r < 0)
 477                goto bad_locked;
 478
 479        r = dm_sm_copy_root(pmd->data_sm, &disk_super->data_space_map_root,
 480                            data_len);
 481        if (r < 0)
 482                goto bad_locked;
 483
 484        disk_super->data_mapping_root = cpu_to_le64(pmd->root);
 485        disk_super->device_details_root = cpu_to_le64(pmd->details_root);
 486        disk_super->metadata_block_size = cpu_to_le32(THIN_METADATA_BLOCK_SIZE >> SECTOR_SHIFT);
 487        disk_super->metadata_nr_blocks = cpu_to_le64(bdev_size >> SECTOR_TO_BLOCK_SHIFT);
 488        disk_super->data_block_size = cpu_to_le32(pmd->data_block_size);
 489
 490        return dm_tm_commit(pmd->tm, sblock);
 491
 492bad_locked:
 493        dm_bm_unlock(sblock);
 494        return r;
 495}
 496
 497static int __format_metadata(struct dm_pool_metadata *pmd)
 498{
 499        int r;
 500
 501        r = dm_tm_create_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION,
 502                                 &pmd->tm, &pmd->metadata_sm);
 503        if (r < 0) {
 504                DMERR("tm_create_with_sm failed");
 505                return r;
 506        }
 507
 508        pmd->data_sm = dm_sm_disk_create(pmd->tm, 0);
 509        if (IS_ERR(pmd->data_sm)) {
 510                DMERR("sm_disk_create failed");
 511                r = PTR_ERR(pmd->data_sm);
 512                goto bad_cleanup_tm;
 513        }
 514
 515        pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);
 516        if (!pmd->nb_tm) {
 517                DMERR("could not create non-blocking clone tm");
 518                r = -ENOMEM;
 519                goto bad_cleanup_data_sm;
 520        }
 521
 522        __setup_btree_details(pmd);
 523
 524        r = dm_btree_empty(&pmd->info, &pmd->root);
 525        if (r < 0)
 526                goto bad_cleanup_nb_tm;
 527
 528        r = dm_btree_empty(&pmd->details_info, &pmd->details_root);
 529        if (r < 0) {
 530                DMERR("couldn't create devices root");
 531                goto bad_cleanup_nb_tm;
 532        }
 533
 534        r = __write_initial_superblock(pmd);
 535        if (r)
 536                goto bad_cleanup_nb_tm;
 537
 538        return 0;
 539
 540bad_cleanup_nb_tm:
 541        dm_tm_destroy(pmd->nb_tm);
 542bad_cleanup_data_sm:
 543        dm_sm_destroy(pmd->data_sm);
 544bad_cleanup_tm:
 545        dm_tm_destroy(pmd->tm);
 546        dm_sm_destroy(pmd->metadata_sm);
 547
 548        return r;
 549}
 550
 551static int __check_incompat_features(struct thin_disk_superblock *disk_super,
 552                                     struct dm_pool_metadata *pmd)
 553{
 554        uint32_t features;
 555
 556        features = le32_to_cpu(disk_super->incompat_flags) & ~THIN_FEATURE_INCOMPAT_SUPP;
 557        if (features) {
 558                DMERR("could not access metadata due to unsupported optional features (%lx).",
 559                      (unsigned long)features);
 560                return -EINVAL;
 561        }
 562
 563        /*
 564         * Check for read-only metadata to skip the following RDWR checks.
 565         */
 566        if (get_disk_ro(pmd->bdev->bd_disk))
 567                return 0;
 568
 569        features = le32_to_cpu(disk_super->compat_ro_flags) & ~THIN_FEATURE_COMPAT_RO_SUPP;
 570        if (features) {
 571                DMERR("could not access metadata RDWR due to unsupported optional features (%lx).",
 572                      (unsigned long)features);
 573                return -EINVAL;
 574        }
 575
 576        return 0;
 577}
 578
 579static int __open_metadata(struct dm_pool_metadata *pmd)
 580{
 581        int r;
 582        struct dm_block *sblock;
 583        struct thin_disk_superblock *disk_super;
 584
 585        r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
 586                            &sb_validator, &sblock);
 587        if (r < 0) {
 588                DMERR("couldn't read superblock");
 589                return r;
 590        }
 591
 592        disk_super = dm_block_data(sblock);
 593
 594        r = __check_incompat_features(disk_super, pmd);
 595        if (r < 0)
 596                goto bad_unlock_sblock;
 597
 598        r = dm_tm_open_with_sm(pmd->bm, THIN_SUPERBLOCK_LOCATION,
 599                               disk_super->metadata_space_map_root,
 600                               sizeof(disk_super->metadata_space_map_root),
 601                               &pmd->tm, &pmd->metadata_sm);
 602        if (r < 0) {
 603                DMERR("tm_open_with_sm failed");
 604                goto bad_unlock_sblock;
 605        }
 606
 607        pmd->data_sm = dm_sm_disk_open(pmd->tm, disk_super->data_space_map_root,
 608                                       sizeof(disk_super->data_space_map_root));
 609        if (IS_ERR(pmd->data_sm)) {
 610                DMERR("sm_disk_open failed");
 611                r = PTR_ERR(pmd->data_sm);
 612                goto bad_cleanup_tm;
 613        }
 614
 615        pmd->nb_tm = dm_tm_create_non_blocking_clone(pmd->tm);
 616        if (!pmd->nb_tm) {
 617                DMERR("could not create non-blocking clone tm");
 618                r = -ENOMEM;
 619                goto bad_cleanup_data_sm;
 620        }
 621
 622        __setup_btree_details(pmd);
 623        return dm_bm_unlock(sblock);
 624
 625bad_cleanup_data_sm:
 626        dm_sm_destroy(pmd->data_sm);
 627bad_cleanup_tm:
 628        dm_tm_destroy(pmd->tm);
 629        dm_sm_destroy(pmd->metadata_sm);
 630bad_unlock_sblock:
 631        dm_bm_unlock(sblock);
 632
 633        return r;
 634}
 635
 636static int __open_or_format_metadata(struct dm_pool_metadata *pmd, bool format_device)
 637{
 638        int r, unformatted;
 639
 640        r = __superblock_all_zeroes(pmd->bm, &unformatted);
 641        if (r)
 642                return r;
 643
 644        if (unformatted)
 645                return format_device ? __format_metadata(pmd) : -EPERM;
 646
 647        return __open_metadata(pmd);
 648}
 649
 650static int __create_persistent_data_objects(struct dm_pool_metadata *pmd, bool format_device)
 651{
 652        int r;
 653
 654        pmd->bm = dm_block_manager_create(pmd->bdev, THIN_METADATA_BLOCK_SIZE,
 655                                          THIN_METADATA_CACHE_SIZE,
 656                                          THIN_MAX_CONCURRENT_LOCKS);
 657        if (IS_ERR(pmd->bm)) {
 658                DMERR("could not create block manager");
 659                return PTR_ERR(pmd->bm);
 660        }
 661
 662        r = __open_or_format_metadata(pmd, format_device);
 663        if (r)
 664                dm_block_manager_destroy(pmd->bm);
 665
 666        return r;
 667}
 668
 669static void __destroy_persistent_data_objects(struct dm_pool_metadata *pmd)
 670{
 671        dm_sm_destroy(pmd->data_sm);
 672        dm_sm_destroy(pmd->metadata_sm);
 673        dm_tm_destroy(pmd->nb_tm);
 674        dm_tm_destroy(pmd->tm);
 675        dm_block_manager_destroy(pmd->bm);
 676}
 677
 678static int __begin_transaction(struct dm_pool_metadata *pmd)
 679{
 680        int r;
 681        struct thin_disk_superblock *disk_super;
 682        struct dm_block *sblock;
 683
 684        /*
 685         * We re-read the superblock every time.  Shouldn't need to do this
 686         * really.
 687         */
 688        r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
 689                            &sb_validator, &sblock);
 690        if (r)
 691                return r;
 692
 693        disk_super = dm_block_data(sblock);
 694        pmd->time = le32_to_cpu(disk_super->time);
 695        pmd->root = le64_to_cpu(disk_super->data_mapping_root);
 696        pmd->details_root = le64_to_cpu(disk_super->device_details_root);
 697        pmd->trans_id = le64_to_cpu(disk_super->trans_id);
 698        pmd->flags = le32_to_cpu(disk_super->flags);
 699        pmd->data_block_size = le32_to_cpu(disk_super->data_block_size);
 700
 701        dm_bm_unlock(sblock);
 702        return 0;
 703}
 704
 705static int __write_changed_details(struct dm_pool_metadata *pmd)
 706{
 707        int r;
 708        struct dm_thin_device *td, *tmp;
 709        struct disk_device_details details;
 710        uint64_t key;
 711
 712        list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
 713                if (!td->changed)
 714                        continue;
 715
 716                key = td->id;
 717
 718                details.mapped_blocks = cpu_to_le64(td->mapped_blocks);
 719                details.transaction_id = cpu_to_le64(td->transaction_id);
 720                details.creation_time = cpu_to_le32(td->creation_time);
 721                details.snapshotted_time = cpu_to_le32(td->snapshotted_time);
 722                __dm_bless_for_disk(&details);
 723
 724                r = dm_btree_insert(&pmd->details_info, pmd->details_root,
 725                                    &key, &details, &pmd->details_root);
 726                if (r)
 727                        return r;
 728
 729                if (td->open_count)
 730                        td->changed = 0;
 731                else {
 732                        list_del(&td->list);
 733                        kfree(td);
 734                }
 735        }
 736
 737        return 0;
 738}
 739
 740static int __commit_transaction(struct dm_pool_metadata *pmd)
 741{
 742        int r;
 743        size_t metadata_len, data_len;
 744        struct thin_disk_superblock *disk_super;
 745        struct dm_block *sblock;
 746
 747        /*
 748         * We need to know if the thin_disk_superblock exceeds a 512-byte sector.
 749         */
 750        BUILD_BUG_ON(sizeof(struct thin_disk_superblock) > 512);
 751
 752        r = __write_changed_details(pmd);
 753        if (r < 0)
 754                return r;
 755
 756        r = dm_sm_commit(pmd->data_sm);
 757        if (r < 0)
 758                return r;
 759
 760        r = dm_tm_pre_commit(pmd->tm);
 761        if (r < 0)
 762                return r;
 763
 764        r = dm_sm_root_size(pmd->metadata_sm, &metadata_len);
 765        if (r < 0)
 766                return r;
 767
 768        r = dm_sm_root_size(pmd->data_sm, &data_len);
 769        if (r < 0)
 770                return r;
 771
 772        r = superblock_lock(pmd, &sblock);
 773        if (r)
 774                return r;
 775
 776        disk_super = dm_block_data(sblock);
 777        disk_super->time = cpu_to_le32(pmd->time);
 778        disk_super->data_mapping_root = cpu_to_le64(pmd->root);
 779        disk_super->device_details_root = cpu_to_le64(pmd->details_root);
 780        disk_super->trans_id = cpu_to_le64(pmd->trans_id);
 781        disk_super->flags = cpu_to_le32(pmd->flags);
 782
 783        r = dm_sm_copy_root(pmd->metadata_sm, &disk_super->metadata_space_map_root,
 784                            metadata_len);
 785        if (r < 0)
 786                goto out_locked;
 787
 788        r = dm_sm_copy_root(pmd->data_sm, &disk_super->data_space_map_root,
 789                            data_len);
 790        if (r < 0)
 791                goto out_locked;
 792
 793        return dm_tm_commit(pmd->tm, sblock);
 794
 795out_locked:
 796        dm_bm_unlock(sblock);
 797        return r;
 798}
 799
 800struct dm_pool_metadata *dm_pool_metadata_open(struct block_device *bdev,
 801                                               sector_t data_block_size,
 802                                               bool format_device)
 803{
 804        int r;
 805        struct dm_pool_metadata *pmd;
 806
 807        pmd = kmalloc(sizeof(*pmd), GFP_KERNEL);
 808        if (!pmd) {
 809                DMERR("could not allocate metadata struct");
 810                return ERR_PTR(-ENOMEM);
 811        }
 812
 813        init_rwsem(&pmd->root_lock);
 814        pmd->time = 0;
 815        INIT_LIST_HEAD(&pmd->thin_devices);
 816        pmd->read_only = false;
 817        pmd->fail_io = false;
 818        pmd->bdev = bdev;
 819        pmd->data_block_size = data_block_size;
 820
 821        r = __create_persistent_data_objects(pmd, format_device);
 822        if (r) {
 823                kfree(pmd);
 824                return ERR_PTR(r);
 825        }
 826
 827        r = __begin_transaction(pmd);
 828        if (r < 0) {
 829                if (dm_pool_metadata_close(pmd) < 0)
 830                        DMWARN("%s: dm_pool_metadata_close() failed.", __func__);
 831                return ERR_PTR(r);
 832        }
 833
 834        return pmd;
 835}
 836
 837int dm_pool_metadata_close(struct dm_pool_metadata *pmd)
 838{
 839        int r;
 840        unsigned open_devices = 0;
 841        struct dm_thin_device *td, *tmp;
 842
 843        down_read(&pmd->root_lock);
 844        list_for_each_entry_safe(td, tmp, &pmd->thin_devices, list) {
 845                if (td->open_count)
 846                        open_devices++;
 847                else {
 848                        list_del(&td->list);
 849                        kfree(td);
 850                }
 851        }
 852        up_read(&pmd->root_lock);
 853
 854        if (open_devices) {
 855                DMERR("attempt to close pmd when %u device(s) are still open",
 856                       open_devices);
 857                return -EBUSY;
 858        }
 859
 860        if (!pmd->read_only && !pmd->fail_io) {
 861                r = __commit_transaction(pmd);
 862                if (r < 0)
 863                        DMWARN("%s: __commit_transaction() failed, error = %d",
 864                               __func__, r);
 865        }
 866
 867        if (!pmd->fail_io)
 868                __destroy_persistent_data_objects(pmd);
 869
 870        kfree(pmd);
 871        return 0;
 872}
 873
 874/*
 875 * __open_device: Returns @td corresponding to device with id @dev,
 876 * creating it if @create is set and incrementing @td->open_count.
 877 * On failure, @td is undefined.
 878 */
 879static int __open_device(struct dm_pool_metadata *pmd,
 880                         dm_thin_id dev, int create,
 881                         struct dm_thin_device **td)
 882{
 883        int r, changed = 0;
 884        struct dm_thin_device *td2;
 885        uint64_t key = dev;
 886        struct disk_device_details details_le;
 887
 888        /*
 889         * If the device is already open, return it.
 890         */
 891        list_for_each_entry(td2, &pmd->thin_devices, list)
 892                if (td2->id == dev) {
 893                        /*
 894                         * May not create an already-open device.
 895                         */
 896                        if (create)
 897                                return -EEXIST;
 898
 899                        td2->open_count++;
 900                        *td = td2;
 901                        return 0;
 902                }
 903
 904        /*
 905         * Check the device exists.
 906         */
 907        r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
 908                            &key, &details_le);
 909        if (r) {
 910                if (r != -ENODATA || !create)
 911                        return r;
 912
 913                /*
 914                 * Create new device.
 915                 */
 916                changed = 1;
 917                details_le.mapped_blocks = 0;
 918                details_le.transaction_id = cpu_to_le64(pmd->trans_id);
 919                details_le.creation_time = cpu_to_le32(pmd->time);
 920                details_le.snapshotted_time = cpu_to_le32(pmd->time);
 921        }
 922
 923        *td = kmalloc(sizeof(**td), GFP_NOIO);
 924        if (!*td)
 925                return -ENOMEM;
 926
 927        (*td)->pmd = pmd;
 928        (*td)->id = dev;
 929        (*td)->open_count = 1;
 930        (*td)->changed = changed;
 931        (*td)->aborted_with_changes = false;
 932        (*td)->mapped_blocks = le64_to_cpu(details_le.mapped_blocks);
 933        (*td)->transaction_id = le64_to_cpu(details_le.transaction_id);
 934        (*td)->creation_time = le32_to_cpu(details_le.creation_time);
 935        (*td)->snapshotted_time = le32_to_cpu(details_le.snapshotted_time);
 936
 937        list_add(&(*td)->list, &pmd->thin_devices);
 938
 939        return 0;
 940}
 941
 942static void __close_device(struct dm_thin_device *td)
 943{
 944        --td->open_count;
 945}
 946
 947static int __create_thin(struct dm_pool_metadata *pmd,
 948                         dm_thin_id dev)
 949{
 950        int r;
 951        dm_block_t dev_root;
 952        uint64_t key = dev;
 953        struct disk_device_details details_le;
 954        struct dm_thin_device *td;
 955        __le64 value;
 956
 957        r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
 958                            &key, &details_le);
 959        if (!r)
 960                return -EEXIST;
 961
 962        /*
 963         * Create an empty btree for the mappings.
 964         */
 965        r = dm_btree_empty(&pmd->bl_info, &dev_root);
 966        if (r)
 967                return r;
 968
 969        /*
 970         * Insert it into the main mapping tree.
 971         */
 972        value = cpu_to_le64(dev_root);
 973        __dm_bless_for_disk(&value);
 974        r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root);
 975        if (r) {
 976                dm_btree_del(&pmd->bl_info, dev_root);
 977                return r;
 978        }
 979
 980        r = __open_device(pmd, dev, 1, &td);
 981        if (r) {
 982                dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
 983                dm_btree_del(&pmd->bl_info, dev_root);
 984                return r;
 985        }
 986        __close_device(td);
 987
 988        return r;
 989}
 990
 991int dm_pool_create_thin(struct dm_pool_metadata *pmd, dm_thin_id dev)
 992{
 993        int r = -EINVAL;
 994
 995        down_write(&pmd->root_lock);
 996        if (!pmd->fail_io)
 997                r = __create_thin(pmd, dev);
 998        up_write(&pmd->root_lock);
 999
1000        return r;
1001}
1002
1003static int __set_snapshot_details(struct dm_pool_metadata *pmd,
1004                                  struct dm_thin_device *snap,
1005                                  dm_thin_id origin, uint32_t time)
1006{
1007        int r;
1008        struct dm_thin_device *td;
1009
1010        r = __open_device(pmd, origin, 0, &td);
1011        if (r)
1012                return r;
1013
1014        td->changed = 1;
1015        td->snapshotted_time = time;
1016
1017        snap->mapped_blocks = td->mapped_blocks;
1018        snap->snapshotted_time = time;
1019        __close_device(td);
1020
1021        return 0;
1022}
1023
1024static int __create_snap(struct dm_pool_metadata *pmd,
1025                         dm_thin_id dev, dm_thin_id origin)
1026{
1027        int r;
1028        dm_block_t origin_root;
1029        uint64_t key = origin, dev_key = dev;
1030        struct dm_thin_device *td;
1031        struct disk_device_details details_le;
1032        __le64 value;
1033
1034        /* check this device is unused */
1035        r = dm_btree_lookup(&pmd->details_info, pmd->details_root,
1036                            &dev_key, &details_le);
1037        if (!r)
1038                return -EEXIST;
1039
1040        /* find the mapping tree for the origin */
1041        r = dm_btree_lookup(&pmd->tl_info, pmd->root, &key, &value);
1042        if (r)
1043                return r;
1044        origin_root = le64_to_cpu(value);
1045
1046        /* clone the origin, an inc will do */
1047        dm_tm_inc(pmd->tm, origin_root);
1048
1049        /* insert into the main mapping tree */
1050        value = cpu_to_le64(origin_root);
1051        __dm_bless_for_disk(&value);
1052        key = dev;
1053        r = dm_btree_insert(&pmd->tl_info, pmd->root, &key, &value, &pmd->root);
1054        if (r) {
1055                dm_tm_dec(pmd->tm, origin_root);
1056                return r;
1057        }
1058
1059        pmd->time++;
1060
1061        r = __open_device(pmd, dev, 1, &td);
1062        if (r)
1063                goto bad;
1064
1065        r = __set_snapshot_details(pmd, td, origin, pmd->time);
1066        __close_device(td);
1067
1068        if (r)
1069                goto bad;
1070
1071        return 0;
1072
1073bad:
1074        dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
1075        dm_btree_remove(&pmd->details_info, pmd->details_root,
1076                        &key, &pmd->details_root);
1077        return r;
1078}
1079
1080int dm_pool_create_snap(struct dm_pool_metadata *pmd,
1081                                 dm_thin_id dev,
1082                                 dm_thin_id origin)
1083{
1084        int r = -EINVAL;
1085
1086        down_write(&pmd->root_lock);
1087        if (!pmd->fail_io)
1088                r = __create_snap(pmd, dev, origin);
1089        up_write(&pmd->root_lock);
1090
1091        return r;
1092}
1093
1094static int __delete_device(struct dm_pool_metadata *pmd, dm_thin_id dev)
1095{
1096        int r;
1097        uint64_t key = dev;
1098        struct dm_thin_device *td;
1099
1100        /* TODO: failure should mark the transaction invalid */
1101        r = __open_device(pmd, dev, 0, &td);
1102        if (r)
1103                return r;
1104
1105        if (td->open_count > 1) {
1106                __close_device(td);
1107                return -EBUSY;
1108        }
1109
1110        list_del(&td->list);
1111        kfree(td);
1112        r = dm_btree_remove(&pmd->details_info, pmd->details_root,
1113                            &key, &pmd->details_root);
1114        if (r)
1115                return r;
1116
1117        r = dm_btree_remove(&pmd->tl_info, pmd->root, &key, &pmd->root);
1118        if (r)
1119                return r;
1120
1121        return 0;
1122}
1123
1124int dm_pool_delete_thin_device(struct dm_pool_metadata *pmd,
1125                               dm_thin_id dev)
1126{
1127        int r = -EINVAL;
1128
1129        down_write(&pmd->root_lock);
1130        if (!pmd->fail_io)
1131                r = __delete_device(pmd, dev);
1132        up_write(&pmd->root_lock);
1133
1134        return r;
1135}
1136
1137int dm_pool_set_metadata_transaction_id(struct dm_pool_metadata *pmd,
1138                                        uint64_t current_id,
1139                                        uint64_t new_id)
1140{
1141        int r = -EINVAL;
1142
1143        down_write(&pmd->root_lock);
1144
1145        if (pmd->fail_io)
1146                goto out;
1147
1148        if (pmd->trans_id != current_id) {
1149                DMERR("mismatched transaction id");
1150                goto out;
1151        }
1152
1153        pmd->trans_id = new_id;
1154        r = 0;
1155
1156out:
1157        up_write(&pmd->root_lock);
1158
1159        return r;
1160}
1161
1162int dm_pool_get_metadata_transaction_id(struct dm_pool_metadata *pmd,
1163                                        uint64_t *result)
1164{
1165        int r = -EINVAL;
1166
1167        down_read(&pmd->root_lock);
1168        if (!pmd->fail_io) {
1169                *result = pmd->trans_id;
1170                r = 0;
1171        }
1172        up_read(&pmd->root_lock);
1173
1174        return r;
1175}
1176
1177static int __reserve_metadata_snap(struct dm_pool_metadata *pmd)
1178{
1179        int r, inc;
1180        struct thin_disk_superblock *disk_super;
1181        struct dm_block *copy, *sblock;
1182        dm_block_t held_root;
1183
1184        /*
1185         * Copy the superblock.
1186         */
1187        dm_sm_inc_block(pmd->metadata_sm, THIN_SUPERBLOCK_LOCATION);
1188        r = dm_tm_shadow_block(pmd->tm, THIN_SUPERBLOCK_LOCATION,
1189                               &sb_validator, &copy, &inc);
1190        if (r)
1191                return r;
1192
1193        BUG_ON(!inc);
1194
1195        held_root = dm_block_location(copy);
1196        disk_super = dm_block_data(copy);
1197
1198        if (le64_to_cpu(disk_super->held_root)) {
1199                DMWARN("Pool metadata snapshot already exists: release this before taking another.");
1200
1201                dm_tm_dec(pmd->tm, held_root);
1202                dm_tm_unlock(pmd->tm, copy);
1203                return -EBUSY;
1204        }
1205
1206        /*
1207         * Wipe the spacemap since we're not publishing this.
1208         */
1209        memset(&disk_super->data_space_map_root, 0,
1210               sizeof(disk_super->data_space_map_root));
1211        memset(&disk_super->metadata_space_map_root, 0,
1212               sizeof(disk_super->metadata_space_map_root));
1213
1214        /*
1215         * Increment the data structures that need to be preserved.
1216         */
1217        dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->data_mapping_root));
1218        dm_tm_inc(pmd->tm, le64_to_cpu(disk_super->device_details_root));
1219        dm_tm_unlock(pmd->tm, copy);
1220
1221        /*
1222         * Write the held root into the superblock.
1223         */
1224        r = superblock_lock(pmd, &sblock);
1225        if (r) {
1226                dm_tm_dec(pmd->tm, held_root);
1227                return r;
1228        }
1229
1230        disk_super = dm_block_data(sblock);
1231        disk_super->held_root = cpu_to_le64(held_root);
1232        dm_bm_unlock(sblock);
1233        return 0;
1234}
1235
1236int dm_pool_reserve_metadata_snap(struct dm_pool_metadata *pmd)
1237{
1238        int r = -EINVAL;
1239
1240        down_write(&pmd->root_lock);
1241        if (!pmd->fail_io)
1242                r = __reserve_metadata_snap(pmd);
1243        up_write(&pmd->root_lock);
1244
1245        return r;
1246}
1247
1248static int __release_metadata_snap(struct dm_pool_metadata *pmd)
1249{
1250        int r;
1251        struct thin_disk_superblock *disk_super;
1252        struct dm_block *sblock, *copy;
1253        dm_block_t held_root;
1254
1255        r = superblock_lock(pmd, &sblock);
1256        if (r)
1257                return r;
1258
1259        disk_super = dm_block_data(sblock);
1260        held_root = le64_to_cpu(disk_super->held_root);
1261        disk_super->held_root = cpu_to_le64(0);
1262
1263        dm_bm_unlock(sblock);
1264
1265        if (!held_root) {
1266                DMWARN("No pool metadata snapshot found: nothing to release.");
1267                return -EINVAL;
1268        }
1269
1270        r = dm_tm_read_lock(pmd->tm, held_root, &sb_validator, &copy);
1271        if (r)
1272                return r;
1273
1274        disk_super = dm_block_data(copy);
1275        dm_sm_dec_block(pmd->metadata_sm, le64_to_cpu(disk_super->data_mapping_root));
1276        dm_sm_dec_block(pmd->metadata_sm, le64_to_cpu(disk_super->device_details_root));
1277        dm_sm_dec_block(pmd->metadata_sm, held_root);
1278
1279        return dm_tm_unlock(pmd->tm, copy);
1280}
1281
1282int dm_pool_release_metadata_snap(struct dm_pool_metadata *pmd)
1283{
1284        int r = -EINVAL;
1285
1286        down_write(&pmd->root_lock);
1287        if (!pmd->fail_io)
1288                r = __release_metadata_snap(pmd);
1289        up_write(&pmd->root_lock);
1290
1291        return r;
1292}
1293
1294static int __get_metadata_snap(struct dm_pool_metadata *pmd,
1295                               dm_block_t *result)
1296{
1297        int r;
1298        struct thin_disk_superblock *disk_super;
1299        struct dm_block *sblock;
1300
1301        r = dm_bm_read_lock(pmd->bm, THIN_SUPERBLOCK_LOCATION,
1302                            &sb_validator, &sblock);
1303        if (r)
1304                return r;
1305
1306        disk_super = dm_block_data(sblock);
1307        *result = le64_to_cpu(disk_super->held_root);
1308
1309        return dm_bm_unlock(sblock);
1310}
1311
1312int dm_pool_get_metadata_snap(struct dm_pool_metadata *pmd,
1313                              dm_block_t *result)
1314{
1315        int r = -EINVAL;
1316
1317        down_read(&pmd->root_lock);
1318        if (!pmd->fail_io)
1319                r = __get_metadata_snap(pmd, result);
1320        up_read(&pmd->root_lock);
1321
1322        return r;
1323}
1324
1325int dm_pool_open_thin_device(struct dm_pool_metadata *pmd, dm_thin_id dev,
1326                             struct dm_thin_device **td)
1327{
1328        int r = -EINVAL;
1329
1330        down_write(&pmd->root_lock);
1331        if (!pmd->fail_io)
1332                r = __open_device(pmd, dev, 0, td);
1333        up_write(&pmd->root_lock);
1334
1335        return r;
1336}
1337
1338int dm_pool_close_thin_device(struct dm_thin_device *td)
1339{
1340        down_write(&td->pmd->root_lock);
1341        __close_device(td);
1342        up_write(&td->pmd->root_lock);
1343
1344        return 0;
1345}
1346
1347dm_thin_id dm_thin_dev_id(struct dm_thin_device *td)
1348{
1349        return td->id;
1350}
1351
1352static bool __snapshotted_since(struct dm_thin_device *td, uint32_t time)
1353{
1354        return td->snapshotted_time > time;
1355}
1356
1357int dm_thin_find_block(struct dm_thin_device *td, dm_block_t block,
1358                       int can_block, struct dm_thin_lookup_result *result)
1359{
1360        int r = -EINVAL;
1361        uint64_t block_time = 0;
1362        __le64 value;
1363        struct dm_pool_metadata *pmd = td->pmd;
1364        dm_block_t keys[2] = { td->id, block };
1365        struct dm_btree_info *info;
1366
1367        if (can_block) {
1368                down_read(&pmd->root_lock);
1369                info = &pmd->info;
1370        } else if (down_read_trylock(&pmd->root_lock))
1371                info = &pmd->nb_info;
1372        else
1373                return -EWOULDBLOCK;
1374
1375        if (pmd->fail_io)
1376                goto out;
1377
1378        r = dm_btree_lookup(info, pmd->root, keys, &value);
1379        if (!r)
1380                block_time = le64_to_cpu(value);
1381
1382out:
1383        up_read(&pmd->root_lock);
1384
1385        if (!r) {
1386                dm_block_t exception_block;
1387                uint32_t exception_time;
1388                unpack_block_time(block_time, &exception_block,
1389                                  &exception_time);
1390                result->block = exception_block;
1391                result->shared = __snapshotted_since(td, exception_time);
1392        }
1393
1394        return r;
1395}
1396
1397static int __insert(struct dm_thin_device *td, dm_block_t block,
1398                    dm_block_t data_block)
1399{
1400        int r, inserted;
1401        __le64 value;
1402        struct dm_pool_metadata *pmd = td->pmd;
1403        dm_block_t keys[2] = { td->id, block };
1404
1405        value = cpu_to_le64(pack_block_time(data_block, pmd->time));
1406        __dm_bless_for_disk(&value);
1407
1408        r = dm_btree_insert_notify(&pmd->info, pmd->root, keys, &value,
1409                                   &pmd->root, &inserted);
1410        if (r)
1411                return r;
1412
1413        td->changed = 1;
1414        if (inserted)
1415                td->mapped_blocks++;
1416
1417        return 0;
1418}
1419
1420int dm_thin_insert_block(struct dm_thin_device *td, dm_block_t block,
1421                         dm_block_t data_block)
1422{
1423        int r = -EINVAL;
1424
1425        down_write(&td->pmd->root_lock);
1426        if (!td->pmd->fail_io)
1427                r = __insert(td, block, data_block);
1428        up_write(&td->pmd->root_lock);
1429
1430        return r;
1431}
1432
1433static int __remove(struct dm_thin_device *td, dm_block_t block)
1434{
1435        int r;
1436        struct dm_pool_metadata *pmd = td->pmd;
1437        dm_block_t keys[2] = { td->id, block };
1438
1439        r = dm_btree_remove(&pmd->info, pmd->root, keys, &pmd->root);
1440        if (r)
1441                return r;
1442
1443        td->mapped_blocks--;
1444        td->changed = 1;
1445
1446        return 0;
1447}
1448
1449int dm_thin_remove_block(struct dm_thin_device *td, dm_block_t block)
1450{
1451        int r = -EINVAL;
1452
1453        down_write(&td->pmd->root_lock);
1454        if (!td->pmd->fail_io)
1455                r = __remove(td, block);
1456        up_write(&td->pmd->root_lock);
1457
1458        return r;
1459}
1460
1461bool dm_thin_changed_this_transaction(struct dm_thin_device *td)
1462{
1463        int r;
1464
1465        down_read(&td->pmd->root_lock);
1466        r = td->changed;
1467        up_read(&td->pmd->root_lock);
1468
1469        return r;
1470}
1471
1472bool dm_thin_aborted_changes(struct dm_thin_device *td)
1473{
1474        bool r;
1475
1476        down_read(&td->pmd->root_lock);
1477        r = td->aborted_with_changes;
1478        up_read(&td->pmd->root_lock);
1479
1480        return r;
1481}
1482
1483int dm_pool_alloc_data_block(struct dm_pool_metadata *pmd, dm_block_t *result)
1484{
1485        int r = -EINVAL;
1486
1487        down_write(&pmd->root_lock);
1488        if (!pmd->fail_io)
1489                r = dm_sm_new_block(pmd->data_sm, result);
1490        up_write(&pmd->root_lock);
1491
1492        return r;
1493}
1494
1495int dm_pool_commit_metadata(struct dm_pool_metadata *pmd)
1496{
1497        int r = -EINVAL;
1498
1499        down_write(&pmd->root_lock);
1500        if (pmd->fail_io)
1501                goto out;
1502
1503        r = __commit_transaction(pmd);
1504        if (r <= 0)
1505                goto out;
1506
1507        /*
1508         * Open the next transaction.
1509         */
1510        r = __begin_transaction(pmd);
1511out:
1512        up_write(&pmd->root_lock);
1513        return r;
1514}
1515
1516static void __set_abort_with_changes_flags(struct dm_pool_metadata *pmd)
1517{
1518        struct dm_thin_device *td;
1519
1520        list_for_each_entry(td, &pmd->thin_devices, list)
1521                td->aborted_with_changes = td->changed;
1522}
1523
1524int dm_pool_abort_metadata(struct dm_pool_metadata *pmd)
1525{
1526        int r = -EINVAL;
1527
1528        down_write(&pmd->root_lock);
1529        if (pmd->fail_io)
1530                goto out;
1531
1532        __set_abort_with_changes_flags(pmd);
1533        __destroy_persistent_data_objects(pmd);
1534        r = __create_persistent_data_objects(pmd, false);
1535        if (r)
1536                pmd->fail_io = true;
1537
1538out:
1539        up_write(&pmd->root_lock);
1540
1541        return r;
1542}
1543
1544int dm_pool_get_free_block_count(struct dm_pool_metadata *pmd, dm_block_t *result)
1545{
1546        int r = -EINVAL;
1547
1548        down_read(&pmd->root_lock);
1549        if (!pmd->fail_io)
1550                r = dm_sm_get_nr_free(pmd->data_sm, result);
1551        up_read(&pmd->root_lock);
1552
1553        return r;
1554}
1555
1556int dm_pool_get_free_metadata_block_count(struct dm_pool_metadata *pmd,
1557                                          dm_block_t *result)
1558{
1559        int r = -EINVAL;
1560
1561        down_read(&pmd->root_lock);
1562        if (!pmd->fail_io)
1563                r = dm_sm_get_nr_free(pmd->metadata_sm, result);
1564        up_read(&pmd->root_lock);
1565
1566        return r;
1567}
1568
1569int dm_pool_get_metadata_dev_size(struct dm_pool_metadata *pmd,
1570                                  dm_block_t *result)
1571{
1572        int r = -EINVAL;
1573
1574        down_read(&pmd->root_lock);
1575        if (!pmd->fail_io)
1576                r = dm_sm_get_nr_blocks(pmd->metadata_sm, result);
1577        up_read(&pmd->root_lock);
1578
1579        return r;
1580}
1581
1582int dm_pool_get_data_block_size(struct dm_pool_metadata *pmd, sector_t *result)
1583{
1584        down_read(&pmd->root_lock);
1585        *result = pmd->data_block_size;
1586        up_read(&pmd->root_lock);
1587
1588        return 0;
1589}
1590
1591int dm_pool_get_data_dev_size(struct dm_pool_metadata *pmd, dm_block_t *result)
1592{
1593        int r = -EINVAL;
1594
1595        down_read(&pmd->root_lock);
1596        if (!pmd->fail_io)
1597                r = dm_sm_get_nr_blocks(pmd->data_sm, result);
1598        up_read(&pmd->root_lock);
1599
1600        return r;
1601}
1602
1603int dm_thin_get_mapped_count(struct dm_thin_device *td, dm_block_t *result)
1604{
1605        int r = -EINVAL;
1606        struct dm_pool_metadata *pmd = td->pmd;
1607
1608        down_read(&pmd->root_lock);
1609        if (!pmd->fail_io) {
1610                *result = td->mapped_blocks;
1611                r = 0;
1612        }
1613        up_read(&pmd->root_lock);
1614
1615        return r;
1616}
1617
1618static int __highest_block(struct dm_thin_device *td, dm_block_t *result)
1619{
1620        int r;
1621        __le64 value_le;
1622        dm_block_t thin_root;
1623        struct dm_pool_metadata *pmd = td->pmd;
1624
1625        r = dm_btree_lookup(&pmd->tl_info, pmd->root, &td->id, &value_le);
1626        if (r)
1627                return r;
1628
1629        thin_root = le64_to_cpu(value_le);
1630
1631        return dm_btree_find_highest_key(&pmd->bl_info, thin_root, result);
1632}
1633
1634int dm_thin_get_highest_mapped_block(struct dm_thin_device *td,
1635                                     dm_block_t *result)
1636{
1637        int r = -EINVAL;
1638        struct dm_pool_metadata *pmd = td->pmd;
1639
1640        down_read(&pmd->root_lock);
1641        if (!pmd->fail_io)
1642                r = __highest_block(td, result);
1643        up_read(&pmd->root_lock);
1644
1645        return r;
1646}
1647
1648static int __resize_space_map(struct dm_space_map *sm, dm_block_t new_count)
1649{
1650        int r;
1651        dm_block_t old_count;
1652
1653        r = dm_sm_get_nr_blocks(sm, &old_count);
1654        if (r)
1655                return r;
1656
1657        if (new_count == old_count)
1658                return 0;
1659
1660        if (new_count < old_count) {
1661                DMERR("cannot reduce size of space map");
1662                return -EINVAL;
1663        }
1664
1665        return dm_sm_extend(sm, new_count - old_count);
1666}
1667
1668int dm_pool_resize_data_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
1669{
1670        int r = -EINVAL;
1671
1672        down_write(&pmd->root_lock);
1673        if (!pmd->fail_io)
1674                r = __resize_space_map(pmd->data_sm, new_count);
1675        up_write(&pmd->root_lock);
1676
1677        return r;
1678}
1679
1680int dm_pool_resize_metadata_dev(struct dm_pool_metadata *pmd, dm_block_t new_count)
1681{
1682        int r = -EINVAL;
1683
1684        down_write(&pmd->root_lock);
1685        if (!pmd->fail_io)
1686                r = __resize_space_map(pmd->metadata_sm, new_count);
1687        up_write(&pmd->root_lock);
1688
1689        return r;
1690}
1691
1692void dm_pool_metadata_read_only(struct dm_pool_metadata *pmd)
1693{
1694        down_write(&pmd->root_lock);
1695        pmd->read_only = true;
1696        dm_bm_set_read_only(pmd->bm);
1697        up_write(&pmd->root_lock);
1698}
1699
1700int dm_pool_register_metadata_threshold(struct dm_pool_metadata *pmd,
1701                                        dm_block_t threshold,
1702                                        dm_sm_threshold_fn fn,
1703                                        void *context)
1704{
1705        int r;
1706
1707        down_write(&pmd->root_lock);
1708        r = dm_sm_register_threshold_callback(pmd->metadata_sm, threshold, fn, context);
1709        up_write(&pmd->root_lock);
1710
1711        return r;
1712}
1713
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