linux/drivers/md/persistent-data/dm-space-map-common.c
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   1/*
   2 * Copyright (C) 2011 Red Hat, Inc.
   3 *
   4 * This file is released under the GPL.
   5 */
   6
   7#include "dm-space-map-common.h"
   8#include "dm-transaction-manager.h"
   9
  10#include <linux/bitops.h>
  11#include <linux/device-mapper.h>
  12
  13#define DM_MSG_PREFIX "space map common"
  14
  15/*----------------------------------------------------------------*/
  16
  17/*
  18 * Index validator.
  19 */
  20#define INDEX_CSUM_XOR 160478
  21
  22static void index_prepare_for_write(struct dm_block_validator *v,
  23                                    struct dm_block *b,
  24                                    size_t block_size)
  25{
  26        struct disk_metadata_index *mi_le = dm_block_data(b);
  27
  28        mi_le->blocknr = cpu_to_le64(dm_block_location(b));
  29        mi_le->csum = cpu_to_le32(dm_bm_checksum(&mi_le->padding,
  30                                                 block_size - sizeof(__le32),
  31                                                 INDEX_CSUM_XOR));
  32}
  33
  34static int index_check(struct dm_block_validator *v,
  35                       struct dm_block *b,
  36                       size_t block_size)
  37{
  38        struct disk_metadata_index *mi_le = dm_block_data(b);
  39        __le32 csum_disk;
  40
  41        if (dm_block_location(b) != le64_to_cpu(mi_le->blocknr)) {
  42                DMERR_LIMIT("index_check failed: blocknr %llu != wanted %llu",
  43                            le64_to_cpu(mi_le->blocknr), dm_block_location(b));
  44                return -ENOTBLK;
  45        }
  46
  47        csum_disk = cpu_to_le32(dm_bm_checksum(&mi_le->padding,
  48                                               block_size - sizeof(__le32),
  49                                               INDEX_CSUM_XOR));
  50        if (csum_disk != mi_le->csum) {
  51                DMERR_LIMIT("index_check failed: csum %u != wanted %u",
  52                            le32_to_cpu(csum_disk), le32_to_cpu(mi_le->csum));
  53                return -EILSEQ;
  54        }
  55
  56        return 0;
  57}
  58
  59static struct dm_block_validator index_validator = {
  60        .name = "index",
  61        .prepare_for_write = index_prepare_for_write,
  62        .check = index_check
  63};
  64
  65/*----------------------------------------------------------------*/
  66
  67/*
  68 * Bitmap validator
  69 */
  70#define BITMAP_CSUM_XOR 240779
  71
  72static void bitmap_prepare_for_write(struct dm_block_validator *v,
  73                                     struct dm_block *b,
  74                                     size_t block_size)
  75{
  76        struct disk_bitmap_header *disk_header = dm_block_data(b);
  77
  78        disk_header->blocknr = cpu_to_le64(dm_block_location(b));
  79        disk_header->csum = cpu_to_le32(dm_bm_checksum(&disk_header->not_used,
  80                                                       block_size - sizeof(__le32),
  81                                                       BITMAP_CSUM_XOR));
  82}
  83
  84static int bitmap_check(struct dm_block_validator *v,
  85                        struct dm_block *b,
  86                        size_t block_size)
  87{
  88        struct disk_bitmap_header *disk_header = dm_block_data(b);
  89        __le32 csum_disk;
  90
  91        if (dm_block_location(b) != le64_to_cpu(disk_header->blocknr)) {
  92                DMERR_LIMIT("bitmap check failed: blocknr %llu != wanted %llu",
  93                            le64_to_cpu(disk_header->blocknr), dm_block_location(b));
  94                return -ENOTBLK;
  95        }
  96
  97        csum_disk = cpu_to_le32(dm_bm_checksum(&disk_header->not_used,
  98                                               block_size - sizeof(__le32),
  99                                               BITMAP_CSUM_XOR));
 100        if (csum_disk != disk_header->csum) {
 101                DMERR_LIMIT("bitmap check failed: csum %u != wanted %u",
 102                            le32_to_cpu(csum_disk), le32_to_cpu(disk_header->csum));
 103                return -EILSEQ;
 104        }
 105
 106        return 0;
 107}
 108
 109static struct dm_block_validator dm_sm_bitmap_validator = {
 110        .name = "sm_bitmap",
 111        .prepare_for_write = bitmap_prepare_for_write,
 112        .check = bitmap_check
 113};
 114
 115/*----------------------------------------------------------------*/
 116
 117#define ENTRIES_PER_WORD 32
 118#define ENTRIES_SHIFT   5
 119
 120static void *dm_bitmap_data(struct dm_block *b)
 121{
 122        return dm_block_data(b) + sizeof(struct disk_bitmap_header);
 123}
 124
 125#define WORD_MASK_HIGH 0xAAAAAAAAAAAAAAAAULL
 126
 127static unsigned bitmap_word_used(void *addr, unsigned b)
 128{
 129        __le64 *words_le = addr;
 130        __le64 *w_le = words_le + (b >> ENTRIES_SHIFT);
 131
 132        uint64_t bits = le64_to_cpu(*w_le);
 133        uint64_t mask = (bits + WORD_MASK_HIGH + 1) & WORD_MASK_HIGH;
 134
 135        return !(~bits & mask);
 136}
 137
 138static unsigned sm_lookup_bitmap(void *addr, unsigned b)
 139{
 140        __le64 *words_le = addr;
 141        __le64 *w_le = words_le + (b >> ENTRIES_SHIFT);
 142        unsigned hi, lo;
 143
 144        b = (b & (ENTRIES_PER_WORD - 1)) << 1;
 145        hi = !!test_bit_le(b, (void *) w_le);
 146        lo = !!test_bit_le(b + 1, (void *) w_le);
 147        return (hi << 1) | lo;
 148}
 149
 150static void sm_set_bitmap(void *addr, unsigned b, unsigned val)
 151{
 152        __le64 *words_le = addr;
 153        __le64 *w_le = words_le + (b >> ENTRIES_SHIFT);
 154
 155        b = (b & (ENTRIES_PER_WORD - 1)) << 1;
 156
 157        if (val & 2)
 158                __set_bit_le(b, (void *) w_le);
 159        else
 160                __clear_bit_le(b, (void *) w_le);
 161
 162        if (val & 1)
 163                __set_bit_le(b + 1, (void *) w_le);
 164        else
 165                __clear_bit_le(b + 1, (void *) w_le);
 166}
 167
 168static int sm_find_free(void *addr, unsigned begin, unsigned end,
 169                        unsigned *result)
 170{
 171        while (begin < end) {
 172                if (!(begin & (ENTRIES_PER_WORD - 1)) &&
 173                    bitmap_word_used(addr, begin)) {
 174                        begin += ENTRIES_PER_WORD;
 175                        continue;
 176                }
 177
 178                if (!sm_lookup_bitmap(addr, begin)) {
 179                        *result = begin;
 180                        return 0;
 181                }
 182
 183                begin++;
 184        }
 185
 186        return -ENOSPC;
 187}
 188
 189/*----------------------------------------------------------------*/
 190
 191static int sm_ll_init(struct ll_disk *ll, struct dm_transaction_manager *tm)
 192{
 193        ll->tm = tm;
 194
 195        ll->bitmap_info.tm = tm;
 196        ll->bitmap_info.levels = 1;
 197
 198        /*
 199         * Because the new bitmap blocks are created via a shadow
 200         * operation, the old entry has already had its reference count
 201         * decremented and we don't need the btree to do any bookkeeping.
 202         */
 203        ll->bitmap_info.value_type.size = sizeof(struct disk_index_entry);
 204        ll->bitmap_info.value_type.inc = NULL;
 205        ll->bitmap_info.value_type.dec = NULL;
 206        ll->bitmap_info.value_type.equal = NULL;
 207
 208        ll->ref_count_info.tm = tm;
 209        ll->ref_count_info.levels = 1;
 210        ll->ref_count_info.value_type.size = sizeof(uint32_t);
 211        ll->ref_count_info.value_type.inc = NULL;
 212        ll->ref_count_info.value_type.dec = NULL;
 213        ll->ref_count_info.value_type.equal = NULL;
 214
 215        ll->block_size = dm_bm_block_size(dm_tm_get_bm(tm));
 216
 217        if (ll->block_size > (1 << 30)) {
 218                DMERR("block size too big to hold bitmaps");
 219                return -EINVAL;
 220        }
 221
 222        ll->entries_per_block = (ll->block_size - sizeof(struct disk_bitmap_header)) *
 223                ENTRIES_PER_BYTE;
 224        ll->nr_blocks = 0;
 225        ll->bitmap_root = 0;
 226        ll->ref_count_root = 0;
 227        ll->bitmap_index_changed = false;
 228
 229        return 0;
 230}
 231
 232int sm_ll_extend(struct ll_disk *ll, dm_block_t extra_blocks)
 233{
 234        int r;
 235        dm_block_t i, nr_blocks, nr_indexes;
 236        unsigned old_blocks, blocks;
 237
 238        nr_blocks = ll->nr_blocks + extra_blocks;
 239        old_blocks = dm_sector_div_up(ll->nr_blocks, ll->entries_per_block);
 240        blocks = dm_sector_div_up(nr_blocks, ll->entries_per_block);
 241
 242        nr_indexes = dm_sector_div_up(nr_blocks, ll->entries_per_block);
 243        if (nr_indexes > ll->max_entries(ll)) {
 244                DMERR("space map too large");
 245                return -EINVAL;
 246        }
 247
 248        /*
 249         * We need to set this before the dm_tm_new_block() call below.
 250         */
 251        ll->nr_blocks = nr_blocks;
 252        for (i = old_blocks; i < blocks; i++) {
 253                struct dm_block *b;
 254                struct disk_index_entry idx;
 255
 256                r = dm_tm_new_block(ll->tm, &dm_sm_bitmap_validator, &b);
 257                if (r < 0)
 258                        return r;
 259
 260                idx.blocknr = cpu_to_le64(dm_block_location(b));
 261
 262                dm_tm_unlock(ll->tm, b);
 263
 264                idx.nr_free = cpu_to_le32(ll->entries_per_block);
 265                idx.none_free_before = 0;
 266
 267                r = ll->save_ie(ll, i, &idx);
 268                if (r < 0)
 269                        return r;
 270        }
 271
 272        return 0;
 273}
 274
 275int sm_ll_lookup_bitmap(struct ll_disk *ll, dm_block_t b, uint32_t *result)
 276{
 277        int r;
 278        dm_block_t index = b;
 279        struct disk_index_entry ie_disk;
 280        struct dm_block *blk;
 281
 282        b = do_div(index, ll->entries_per_block);
 283        r = ll->load_ie(ll, index, &ie_disk);
 284        if (r < 0)
 285                return r;
 286
 287        r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr),
 288                            &dm_sm_bitmap_validator, &blk);
 289        if (r < 0)
 290                return r;
 291
 292        *result = sm_lookup_bitmap(dm_bitmap_data(blk), b);
 293
 294        dm_tm_unlock(ll->tm, blk);
 295
 296        return 0;
 297}
 298
 299static int sm_ll_lookup_big_ref_count(struct ll_disk *ll, dm_block_t b,
 300                                      uint32_t *result)
 301{
 302        __le32 le_rc;
 303        int r;
 304
 305        r = dm_btree_lookup(&ll->ref_count_info, ll->ref_count_root, &b, &le_rc);
 306        if (r < 0)
 307                return r;
 308
 309        *result = le32_to_cpu(le_rc);
 310
 311        return r;
 312}
 313
 314int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result)
 315{
 316        int r = sm_ll_lookup_bitmap(ll, b, result);
 317
 318        if (r)
 319                return r;
 320
 321        if (*result != 3)
 322                return r;
 323
 324        return sm_ll_lookup_big_ref_count(ll, b, result);
 325}
 326
 327int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
 328                          dm_block_t end, dm_block_t *result)
 329{
 330        int r;
 331        struct disk_index_entry ie_disk;
 332        dm_block_t i, index_begin = begin;
 333        dm_block_t index_end = dm_sector_div_up(end, ll->entries_per_block);
 334
 335        /*
 336         * FIXME: Use shifts
 337         */
 338        begin = do_div(index_begin, ll->entries_per_block);
 339        end = do_div(end, ll->entries_per_block);
 340
 341        for (i = index_begin; i < index_end; i++, begin = 0) {
 342                struct dm_block *blk;
 343                unsigned position;
 344                uint32_t bit_end;
 345
 346                r = ll->load_ie(ll, i, &ie_disk);
 347                if (r < 0)
 348                        return r;
 349
 350                if (le32_to_cpu(ie_disk.nr_free) == 0)
 351                        continue;
 352
 353                r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr),
 354                                    &dm_sm_bitmap_validator, &blk);
 355                if (r < 0)
 356                        return r;
 357
 358                bit_end = (i == index_end - 1) ?  end : ll->entries_per_block;
 359
 360                r = sm_find_free(dm_bitmap_data(blk),
 361                                 max_t(unsigned, begin, le32_to_cpu(ie_disk.none_free_before)),
 362                                 bit_end, &position);
 363                if (r == -ENOSPC) {
 364                        /*
 365                         * This might happen because we started searching
 366                         * part way through the bitmap.
 367                         */
 368                        dm_tm_unlock(ll->tm, blk);
 369                        continue;
 370
 371                } else if (r < 0) {
 372                        dm_tm_unlock(ll->tm, blk);
 373                        return r;
 374                }
 375
 376                dm_tm_unlock(ll->tm, blk);
 377
 378                *result = i * ll->entries_per_block + (dm_block_t) position;
 379                return 0;
 380        }
 381
 382        return -ENOSPC;
 383}
 384
 385static int sm_ll_mutate(struct ll_disk *ll, dm_block_t b,
 386                        int (*mutator)(void *context, uint32_t old, uint32_t *new),
 387                        void *context, enum allocation_event *ev)
 388{
 389        int r;
 390        uint32_t bit, old, ref_count;
 391        struct dm_block *nb;
 392        dm_block_t index = b;
 393        struct disk_index_entry ie_disk;
 394        void *bm_le;
 395        int inc;
 396
 397        bit = do_div(index, ll->entries_per_block);
 398        r = ll->load_ie(ll, index, &ie_disk);
 399        if (r < 0)
 400                return r;
 401
 402        r = dm_tm_shadow_block(ll->tm, le64_to_cpu(ie_disk.blocknr),
 403                               &dm_sm_bitmap_validator, &nb, &inc);
 404        if (r < 0) {
 405                DMERR("dm_tm_shadow_block() failed");
 406                return r;
 407        }
 408        ie_disk.blocknr = cpu_to_le64(dm_block_location(nb));
 409
 410        bm_le = dm_bitmap_data(nb);
 411        old = sm_lookup_bitmap(bm_le, bit);
 412
 413        if (old > 2) {
 414                r = sm_ll_lookup_big_ref_count(ll, b, &old);
 415                if (r < 0) {
 416                        dm_tm_unlock(ll->tm, nb);
 417                        return r;
 418                }
 419        }
 420
 421        r = mutator(context, old, &ref_count);
 422        if (r) {
 423                dm_tm_unlock(ll->tm, nb);
 424                return r;
 425        }
 426
 427        if (ref_count <= 2) {
 428                sm_set_bitmap(bm_le, bit, ref_count);
 429
 430                dm_tm_unlock(ll->tm, nb);
 431
 432                if (old > 2) {
 433                        r = dm_btree_remove(&ll->ref_count_info,
 434                                            ll->ref_count_root,
 435                                            &b, &ll->ref_count_root);
 436                        if (r)
 437                                return r;
 438                }
 439
 440        } else {
 441                __le32 le_rc = cpu_to_le32(ref_count);
 442
 443                sm_set_bitmap(bm_le, bit, 3);
 444                dm_tm_unlock(ll->tm, nb);
 445
 446                __dm_bless_for_disk(&le_rc);
 447                r = dm_btree_insert(&ll->ref_count_info, ll->ref_count_root,
 448                                    &b, &le_rc, &ll->ref_count_root);
 449                if (r < 0) {
 450                        DMERR("ref count insert failed");
 451                        return r;
 452                }
 453        }
 454
 455        if (ref_count && !old) {
 456                *ev = SM_ALLOC;
 457                ll->nr_allocated++;
 458                le32_add_cpu(&ie_disk.nr_free, -1);
 459                if (le32_to_cpu(ie_disk.none_free_before) == bit)
 460                        ie_disk.none_free_before = cpu_to_le32(bit + 1);
 461
 462        } else if (old && !ref_count) {
 463                *ev = SM_FREE;
 464                ll->nr_allocated--;
 465                le32_add_cpu(&ie_disk.nr_free, 1);
 466                ie_disk.none_free_before = cpu_to_le32(min(le32_to_cpu(ie_disk.none_free_before), bit));
 467        } else
 468                *ev = SM_NONE;
 469
 470        return ll->save_ie(ll, index, &ie_disk);
 471}
 472
 473static int set_ref_count(void *context, uint32_t old, uint32_t *new)
 474{
 475        *new = *((uint32_t *) context);
 476        return 0;
 477}
 478
 479int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
 480                 uint32_t ref_count, enum allocation_event *ev)
 481{
 482        return sm_ll_mutate(ll, b, set_ref_count, &ref_count, ev);
 483}
 484
 485static int inc_ref_count(void *context, uint32_t old, uint32_t *new)
 486{
 487        *new = old + 1;
 488        return 0;
 489}
 490
 491int sm_ll_inc(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
 492{
 493        return sm_ll_mutate(ll, b, inc_ref_count, NULL, ev);
 494}
 495
 496static int dec_ref_count(void *context, uint32_t old, uint32_t *new)
 497{
 498        if (!old) {
 499                DMERR_LIMIT("unable to decrement a reference count below 0");
 500                return -EINVAL;
 501        }
 502
 503        *new = old - 1;
 504        return 0;
 505}
 506
 507int sm_ll_dec(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
 508{
 509        return sm_ll_mutate(ll, b, dec_ref_count, NULL, ev);
 510}
 511
 512int sm_ll_commit(struct ll_disk *ll)
 513{
 514        int r = 0;
 515
 516        if (ll->bitmap_index_changed) {
 517                r = ll->commit(ll);
 518                if (!r)
 519                        ll->bitmap_index_changed = false;
 520        }
 521
 522        return r;
 523}
 524
 525/*----------------------------------------------------------------*/
 526
 527static int metadata_ll_load_ie(struct ll_disk *ll, dm_block_t index,
 528                               struct disk_index_entry *ie)
 529{
 530        memcpy(ie, ll->mi_le.index + index, sizeof(*ie));
 531        return 0;
 532}
 533
 534static int metadata_ll_save_ie(struct ll_disk *ll, dm_block_t index,
 535                               struct disk_index_entry *ie)
 536{
 537        ll->bitmap_index_changed = true;
 538        memcpy(ll->mi_le.index + index, ie, sizeof(*ie));
 539        return 0;
 540}
 541
 542static int metadata_ll_init_index(struct ll_disk *ll)
 543{
 544        int r;
 545        struct dm_block *b;
 546
 547        r = dm_tm_new_block(ll->tm, &index_validator, &b);
 548        if (r < 0)
 549                return r;
 550
 551        ll->bitmap_root = dm_block_location(b);
 552
 553        dm_tm_unlock(ll->tm, b);
 554
 555        return 0;
 556}
 557
 558static int metadata_ll_open(struct ll_disk *ll)
 559{
 560        int r;
 561        struct dm_block *block;
 562
 563        r = dm_tm_read_lock(ll->tm, ll->bitmap_root,
 564                            &index_validator, &block);
 565        if (r)
 566                return r;
 567
 568        memcpy(&ll->mi_le, dm_block_data(block), sizeof(ll->mi_le));
 569        dm_tm_unlock(ll->tm, block);
 570
 571        return 0;
 572}
 573
 574static dm_block_t metadata_ll_max_entries(struct ll_disk *ll)
 575{
 576        return MAX_METADATA_BITMAPS;
 577}
 578
 579static int metadata_ll_commit(struct ll_disk *ll)
 580{
 581        int r, inc;
 582        struct dm_block *b;
 583
 584        r = dm_tm_shadow_block(ll->tm, ll->bitmap_root, &index_validator, &b, &inc);
 585        if (r)
 586                return r;
 587
 588        memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le));
 589        ll->bitmap_root = dm_block_location(b);
 590
 591        dm_tm_unlock(ll->tm, b);
 592
 593        return 0;
 594}
 595
 596int sm_ll_new_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm)
 597{
 598        int r;
 599
 600        r = sm_ll_init(ll, tm);
 601        if (r < 0)
 602                return r;
 603
 604        ll->load_ie = metadata_ll_load_ie;
 605        ll->save_ie = metadata_ll_save_ie;
 606        ll->init_index = metadata_ll_init_index;
 607        ll->open_index = metadata_ll_open;
 608        ll->max_entries = metadata_ll_max_entries;
 609        ll->commit = metadata_ll_commit;
 610
 611        ll->nr_blocks = 0;
 612        ll->nr_allocated = 0;
 613
 614        r = ll->init_index(ll);
 615        if (r < 0)
 616                return r;
 617
 618        r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
 619        if (r < 0)
 620                return r;
 621
 622        return 0;
 623}
 624
 625int sm_ll_open_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm,
 626                        void *root_le, size_t len)
 627{
 628        int r;
 629        struct disk_sm_root smr;
 630
 631        if (len < sizeof(struct disk_sm_root)) {
 632                DMERR("sm_metadata root too small");
 633                return -ENOMEM;
 634        }
 635
 636        /*
 637         * We don't know the alignment of the root_le buffer, so need to
 638         * copy into a new structure.
 639         */
 640        memcpy(&smr, root_le, sizeof(smr));
 641
 642        r = sm_ll_init(ll, tm);
 643        if (r < 0)
 644                return r;
 645
 646        ll->load_ie = metadata_ll_load_ie;
 647        ll->save_ie = metadata_ll_save_ie;
 648        ll->init_index = metadata_ll_init_index;
 649        ll->open_index = metadata_ll_open;
 650        ll->max_entries = metadata_ll_max_entries;
 651        ll->commit = metadata_ll_commit;
 652
 653        ll->nr_blocks = le64_to_cpu(smr.nr_blocks);
 654        ll->nr_allocated = le64_to_cpu(smr.nr_allocated);
 655        ll->bitmap_root = le64_to_cpu(smr.bitmap_root);
 656        ll->ref_count_root = le64_to_cpu(smr.ref_count_root);
 657
 658        return ll->open_index(ll);
 659}
 660
 661/*----------------------------------------------------------------*/
 662
 663static int disk_ll_load_ie(struct ll_disk *ll, dm_block_t index,
 664                           struct disk_index_entry *ie)
 665{
 666        return dm_btree_lookup(&ll->bitmap_info, ll->bitmap_root, &index, ie);
 667}
 668
 669static int disk_ll_save_ie(struct ll_disk *ll, dm_block_t index,
 670                           struct disk_index_entry *ie)
 671{
 672        __dm_bless_for_disk(ie);
 673        return dm_btree_insert(&ll->bitmap_info, ll->bitmap_root,
 674                               &index, ie, &ll->bitmap_root);
 675}
 676
 677static int disk_ll_init_index(struct ll_disk *ll)
 678{
 679        return dm_btree_empty(&ll->bitmap_info, &ll->bitmap_root);
 680}
 681
 682static int disk_ll_open(struct ll_disk *ll)
 683{
 684        /* nothing to do */
 685        return 0;
 686}
 687
 688static dm_block_t disk_ll_max_entries(struct ll_disk *ll)
 689{
 690        return -1ULL;
 691}
 692
 693static int disk_ll_commit(struct ll_disk *ll)
 694{
 695        return 0;
 696}
 697
 698int sm_ll_new_disk(struct ll_disk *ll, struct dm_transaction_manager *tm)
 699{
 700        int r;
 701
 702        r = sm_ll_init(ll, tm);
 703        if (r < 0)
 704                return r;
 705
 706        ll->load_ie = disk_ll_load_ie;
 707        ll->save_ie = disk_ll_save_ie;
 708        ll->init_index = disk_ll_init_index;
 709        ll->open_index = disk_ll_open;
 710        ll->max_entries = disk_ll_max_entries;
 711        ll->commit = disk_ll_commit;
 712
 713        ll->nr_blocks = 0;
 714        ll->nr_allocated = 0;
 715
 716        r = ll->init_index(ll);
 717        if (r < 0)
 718                return r;
 719
 720        r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
 721        if (r < 0)
 722                return r;
 723
 724        return 0;
 725}
 726
 727int sm_ll_open_disk(struct ll_disk *ll, struct dm_transaction_manager *tm,
 728                    void *root_le, size_t len)
 729{
 730        int r;
 731        struct disk_sm_root *smr = root_le;
 732
 733        if (len < sizeof(struct disk_sm_root)) {
 734                DMERR("sm_metadata root too small");
 735                return -ENOMEM;
 736        }
 737
 738        r = sm_ll_init(ll, tm);
 739        if (r < 0)
 740                return r;
 741
 742        ll->load_ie = disk_ll_load_ie;
 743        ll->save_ie = disk_ll_save_ie;
 744        ll->init_index = disk_ll_init_index;
 745        ll->open_index = disk_ll_open;
 746        ll->max_entries = disk_ll_max_entries;
 747        ll->commit = disk_ll_commit;
 748
 749        ll->nr_blocks = le64_to_cpu(smr->nr_blocks);
 750        ll->nr_allocated = le64_to_cpu(smr->nr_allocated);
 751        ll->bitmap_root = le64_to_cpu(smr->bitmap_root);
 752        ll->ref_count_root = le64_to_cpu(smr->ref_count_root);
 753
 754        return ll->open_index(ll);
 755}
 756
 757/*----------------------------------------------------------------*/
 758