drivers/md/persistent-data/dm-space-map-common.c

   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
  22 static 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
  34 static 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("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("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
  59 static 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
  72 static 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
  84 static 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("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("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
 109 static 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
 120 static 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
 127 static 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
 138 static 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
 150 static 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
 168 static 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
 191 static 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
 228         return 0;
 229 }
 230
 231 int sm_ll_extend(struct ll_disk *ll, dm_block_t extra_blocks)
 232 {
 233         int r;
 234         dm_block_t i, nr_blocks, nr_indexes;
 235         unsigned old_blocks, blocks;
 236
 237         nr_blocks = ll->nr_blocks + extra_blocks;
 238         old_blocks = dm_sector_div_up(ll->nr_blocks, ll->entries_per_block);
 239         blocks = dm_sector_div_up(nr_blocks, ll->entries_per_block);
 240
 241         nr_indexes = dm_sector_div_up(nr_blocks, ll->entries_per_block);
 242         if (nr_indexes > ll->max_entries(ll)) {
 243                 DMERR("space map too large");
 244                 return -EINVAL;
 245         }
 246
 247         for (i = old_blocks; i < blocks; i++) {
 248                 struct dm_block *b;
 249                 struct disk_index_entry idx;
 250
 251                 r = dm_tm_new_block(ll->tm, &dm_sm_bitmap_validator, &b);
 252                 if (r < 0)
 253                         return r;
 254                 idx.blocknr = cpu_to_le64(dm_block_location(b));
 255
 256                 r = dm_tm_unlock(ll->tm, b);
 257                 if (r < 0)
 258                         return r;
 259
 260                 idx.nr_free = cpu_to_le32(ll->entries_per_block);
 261                 idx.none_free_before = 0;
 262
 263                 r = ll->save_ie(ll, i, &idx);
 264                 if (r < 0)
 265                         return r;
 266         }
 267
 268         ll->nr_blocks = nr_blocks;
 269         return 0;
 270 }
 271
 272 int sm_ll_lookup_bitmap(struct ll_disk *ll, dm_block_t b, uint32_t *result)
 273 {
 274         int r;
 275         dm_block_t index = b;
 276         struct disk_index_entry ie_disk;
 277         struct dm_block *blk;
 278
 279         b = do_div(index, ll->entries_per_block);
 280         r = ll->load_ie(ll, index, &ie_disk);
 281         if (r < 0)
 282                 return r;
 283
 284         r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr),
 285                             &dm_sm_bitmap_validator, &blk);
 286         if (r < 0)
 287                 return r;
 288
 289         *result = sm_lookup_bitmap(dm_bitmap_data(blk), b);
 290
 291         return dm_tm_unlock(ll->tm, blk);
 292 }
 293
 294 int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result)
 295 {
 296         __le32 le_rc;
 297         int r = sm_ll_lookup_bitmap(ll, b, result);
 298
 299         if (r)
 300                 return r;
 301
 302         if (*result != 3)
 303                 return 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
 314 int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
 315                           dm_block_t end, dm_block_t *result)
 316 {
 317         int r;
 318         struct disk_index_entry ie_disk;
 319         dm_block_t i, index_begin = begin;
 320         dm_block_t index_end = dm_sector_div_up(end, ll->entries_per_block);
 321
 322         /*
 323          * FIXME: Use shifts
 324          */
 325         begin = do_div(index_begin, ll->entries_per_block);
 326         end = do_div(end, ll->entries_per_block);
 327
 328         for (i = index_begin; i < index_end; i++, begin = 0) {
 329                 struct dm_block *blk;
 330                 unsigned position;
 331                 uint32_t bit_end;
 332
 333                 r = ll->load_ie(ll, i, &ie_disk);
 334                 if (r < 0)
 335                         return r;
 336
 337                 if (le32_to_cpu(ie_disk.nr_free) == 0)
 338                         continue;
 339
 340                 r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr),
 341                                     &dm_sm_bitmap_validator, &blk);
 342                 if (r < 0)
 343                         return r;
 344
 345                 bit_end = (i == index_end - 1) ?  end : ll->entries_per_block;
 346
 347                 r = sm_find_free(dm_bitmap_data(blk),
 348                                  max_t(unsigned, begin, le32_to_cpu(ie_disk.none_free_before)),
 349                                  bit_end, &position);
 350                 if (r == -ENOSPC) {
 351                         /*
 352                          * This might happen because we started searching
 353                          * part way through the bitmap.
 354                          */
 355                         dm_tm_unlock(ll->tm, blk);
 356                         continue;
 357
 358                 } else if (r < 0) {
 359                         dm_tm_unlock(ll->tm, blk);
 360                         return r;
 361                 }
 362
 363                 r = dm_tm_unlock(ll->tm, blk);
 364                 if (r < 0)
 365                         return r;
 366
 367                 *result = i * ll->entries_per_block + (dm_block_t) position;
 368                 return 0;
 369         }
 370
 371         return -ENOSPC;
 372 }
 373
 374 int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
 375                  uint32_t ref_count, enum allocation_event *ev)
 376 {
 377         int r;
 378         uint32_t bit, old;
 379         struct dm_block *nb;
 380         dm_block_t index = b;
 381         struct disk_index_entry ie_disk;
 382         void *bm_le;
 383         int inc;
 384
 385         bit = do_div(index, ll->entries_per_block);
 386         r = ll->load_ie(ll, index, &ie_disk);
 387         if (r < 0)
 388                 return r;
 389
 390         r = dm_tm_shadow_block(ll->tm, le64_to_cpu(ie_disk.blocknr),
 391                                &dm_sm_bitmap_validator, &nb, &inc);
 392         if (r < 0) {
 393                 DMERR("dm_tm_shadow_block() failed");
 394                 return r;
 395         }
 396         ie_disk.blocknr = cpu_to_le64(dm_block_location(nb));
 397
 398         bm_le = dm_bitmap_data(nb);
 399         old = sm_lookup_bitmap(bm_le, bit);
 400
 401         if (ref_count <= 2) {
 402                 sm_set_bitmap(bm_le, bit, ref_count);
 403
 404                 r = dm_tm_unlock(ll->tm, nb);
 405                 if (r < 0)
 406                         return r;
 407
 408                 if (old > 2) {
 409                         r = dm_btree_remove(&ll->ref_count_info,
 410                                             ll->ref_count_root,
 411                                             &b, &ll->ref_count_root);
 412                         if (r)
 413                                 return r;
 414                 }
 415
 416         } else {
 417                 __le32 le_rc = cpu_to_le32(ref_count);
 418
 419                 sm_set_bitmap(bm_le, bit, 3);
 420                 r = dm_tm_unlock(ll->tm, nb);
 421                 if (r < 0)
 422                         return r;
 423
 424                 __dm_bless_for_disk(&le_rc);
 425                 r = dm_btree_insert(&ll->ref_count_info, ll->ref_count_root,
 426                                     &b, &le_rc, &ll->ref_count_root);
 427                 if (r < 0) {
 428                         DMERR("ref count insert failed");
 429                         return r;
 430                 }
 431         }
 432
 433         if (ref_count && !old) {
 434                 *ev = SM_ALLOC;
 435                 ll->nr_allocated++;
 436                 ie_disk.nr_free = cpu_to_le32(le32_to_cpu(ie_disk.nr_free) - 1);
 437                 if (le32_to_cpu(ie_disk.none_free_before) == bit)
 438                         ie_disk.none_free_before = cpu_to_le32(bit + 1);
 439
 440         } else if (old && !ref_count) {
 441                 *ev = SM_FREE;
 442                 ll->nr_allocated--;
 443                 ie_disk.nr_free = cpu_to_le32(le32_to_cpu(ie_disk.nr_free) + 1);
 444                 ie_disk.none_free_before = cpu_to_le32(min(le32_to_cpu(ie_disk.none_free_before), bit));
 445         }
 446
 447         return ll->save_ie(ll, index, &ie_disk);
 448 }
 449
 450 int sm_ll_inc(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
 451 {
 452         int r;
 453         uint32_t rc;
 454
 455         r = sm_ll_lookup(ll, b, &rc);
 456         if (r)
 457                 return r;
 458
 459         return sm_ll_insert(ll, b, rc + 1, ev);
 460 }
 461
 462 int sm_ll_dec(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
 463 {
 464         int r;
 465         uint32_t rc;
 466
 467         r = sm_ll_lookup(ll, b, &rc);
 468         if (r)
 469                 return r;
 470
 471         if (!rc)
 472                 return -EINVAL;
 473
 474         return sm_ll_insert(ll, b, rc - 1, ev);
 475 }
 476
 477 int sm_ll_commit(struct ll_disk *ll)
 478 {
 479         return ll->commit(ll);
 480 }
 481
 482 /*----------------------------------------------------------------*/
 483
 484 static int metadata_ll_load_ie(struct ll_disk *ll, dm_block_t index,
 485                                struct disk_index_entry *ie)
 486 {
 487         memcpy(ie, ll->mi_le.index + index, sizeof(*ie));
 488         return 0;
 489 }
 490
 491 static int metadata_ll_save_ie(struct ll_disk *ll, dm_block_t index,
 492                                struct disk_index_entry *ie)
 493 {
 494         memcpy(ll->mi_le.index + index, ie, sizeof(*ie));
 495         return 0;
 496 }
 497
 498 static int metadata_ll_init_index(struct ll_disk *ll)
 499 {
 500         int r;
 501         struct dm_block *b;
 502
 503         r = dm_tm_new_block(ll->tm, &index_validator, &b);
 504         if (r < 0)
 505                 return r;
 506
 507         memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le));
 508         ll->bitmap_root = dm_block_location(b);
 509
 510         return dm_tm_unlock(ll->tm, b);
 511 }
 512
 513 static int metadata_ll_open(struct ll_disk *ll)
 514 {
 515         int r;
 516         struct dm_block *block;
 517
 518         r = dm_tm_read_lock(ll->tm, ll->bitmap_root,
 519                             &index_validator, &block);
 520         if (r)
 521                 return r;
 522
 523         memcpy(&ll->mi_le, dm_block_data(block), sizeof(ll->mi_le));
 524         return dm_tm_unlock(ll->tm, block);
 525 }
 526
 527 static dm_block_t metadata_ll_max_entries(struct ll_disk *ll)
 528 {
 529         return MAX_METADATA_BITMAPS;
 530 }
 531
 532 static int metadata_ll_commit(struct ll_disk *ll)
 533 {
 534         int r, inc;
 535         struct dm_block *b;
 536
 537         r = dm_tm_shadow_block(ll->tm, ll->bitmap_root, &index_validator, &b, &inc);
 538         if (r)
 539                 return r;
 540
 541         memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le));
 542         ll->bitmap_root = dm_block_location(b);
 543
 544         return dm_tm_unlock(ll->tm, b);
 545 }
 546
 547 int sm_ll_new_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm)
 548 {
 549         int r;
 550
 551         r = sm_ll_init(ll, tm);
 552         if (r < 0)
 553                 return r;
 554
 555         ll->load_ie = metadata_ll_load_ie;
 556         ll->save_ie = metadata_ll_save_ie;
 557         ll->init_index = metadata_ll_init_index;
 558         ll->open_index = metadata_ll_open;
 559         ll->max_entries = metadata_ll_max_entries;
 560         ll->commit = metadata_ll_commit;
 561
 562         ll->nr_blocks = 0;
 563         ll->nr_allocated = 0;
 564
 565         r = ll->init_index(ll);
 566         if (r < 0)
 567                 return r;
 568
 569         r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
 570         if (r < 0)
 571                 return r;
 572
 573         return 0;
 574 }
 575
 576 int sm_ll_open_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm,
 577                         void *root_le, size_t len)
 578 {
 579         int r;
 580         struct disk_sm_root *smr = root_le;
 581
 582         if (len < sizeof(struct disk_sm_root)) {
 583                 DMERR("sm_metadata root too small");
 584                 return -ENOMEM;
 585         }
 586
 587         r = sm_ll_init(ll, tm);
 588         if (r < 0)
 589                 return r;
 590
 591         ll->load_ie = metadata_ll_load_ie;
 592         ll->save_ie = metadata_ll_save_ie;
 593         ll->init_index = metadata_ll_init_index;
 594         ll->open_index = metadata_ll_open;
 595         ll->max_entries = metadata_ll_max_entries;
 596         ll->commit = metadata_ll_commit;
 597
 598         ll->nr_blocks = le64_to_cpu(smr->nr_blocks);
 599         ll->nr_allocated = le64_to_cpu(smr->nr_allocated);
 600         ll->bitmap_root = le64_to_cpu(smr->bitmap_root);
 601         ll->ref_count_root = le64_to_cpu(smr->ref_count_root);
 602
 603         return ll->open_index(ll);
 604 }
 605
 606 /*----------------------------------------------------------------*/
 607
 608 static int disk_ll_load_ie(struct ll_disk *ll, dm_block_t index,
 609                            struct disk_index_entry *ie)
 610 {
 611         return dm_btree_lookup(&ll->bitmap_info, ll->bitmap_root, &index, ie);
 612 }
 613
 614 static int disk_ll_save_ie(struct ll_disk *ll, dm_block_t index,
 615                            struct disk_index_entry *ie)
 616 {
 617         __dm_bless_for_disk(ie);
 618         return dm_btree_insert(&ll->bitmap_info, ll->bitmap_root,
 619                                &index, ie, &ll->bitmap_root);
 620 }
 621
 622 static int disk_ll_init_index(struct ll_disk *ll)
 623 {
 624         return dm_btree_empty(&ll->bitmap_info, &ll->bitmap_root);
 625 }
 626
 627 static int disk_ll_open(struct ll_disk *ll)
 628 {
 629         /* nothing to do */
 630         return 0;
 631 }
 632
 633 static dm_block_t disk_ll_max_entries(struct ll_disk *ll)
 634 {
 635         return -1ULL;
 636 }
 637
 638 static int disk_ll_commit(struct ll_disk *ll)
 639 {
 640         return 0;
 641 }
 642
 643 int sm_ll_new_disk(struct ll_disk *ll, struct dm_transaction_manager *tm)
 644 {
 645         int r;
 646
 647         r = sm_ll_init(ll, tm);
 648         if (r < 0)
 649                 return r;
 650
 651         ll->load_ie = disk_ll_load_ie;
 652         ll->save_ie = disk_ll_save_ie;
 653         ll->init_index = disk_ll_init_index;
 654         ll->open_index = disk_ll_open;
 655         ll->max_entries = disk_ll_max_entries;
 656         ll->commit = disk_ll_commit;
 657
 658         ll->nr_blocks = 0;
 659         ll->nr_allocated = 0;
 660
 661         r = ll->init_index(ll);
 662         if (r < 0)
 663                 return r;
 664
 665         r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
 666         if (r < 0)
 667                 return r;
 668
 669         return 0;
 670 }
 671
 672 int sm_ll_open_disk(struct ll_disk *ll, struct dm_transaction_manager *tm,
 673                     void *root_le, size_t len)
 674 {
 675         int r;
 676         struct disk_sm_root *smr = root_le;
 677
 678         if (len < sizeof(struct disk_sm_root)) {
 679                 DMERR("sm_metadata root too small");
 680                 return -ENOMEM;
 681         }
 682
 683         r = sm_ll_init(ll, tm);
 684         if (r < 0)
 685                 return r;
 686
 687         ll->load_ie = disk_ll_load_ie;
 688         ll->save_ie = disk_ll_save_ie;
 689         ll->init_index = disk_ll_init_index;
 690         ll->open_index = disk_ll_open;
 691         ll->max_entries = disk_ll_max_entries;
 692         ll->commit = disk_ll_commit;
 693
 694         ll->nr_blocks = le64_to_cpu(smr->nr_blocks);
 695         ll->nr_allocated = le64_to_cpu(smr->nr_allocated);
 696         ll->bitmap_root = le64_to_cpu(smr->bitmap_root);
 697         ll->ref_count_root = le64_to_cpu(smr->ref_count_root);
 698
 699         return ll->open_index(ll);
 700 }
 701
 702 /*----------------------------------------------------------------*/