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         /*
 248          * We need to set this before the dm_tm_new_block() call below.
 249          */
 250         ll->nr_blocks = nr_blocks;
 251         for (i = old_blocks; i < blocks; i++) {
 252                 struct dm_block *b;
 253                 struct disk_index_entry idx;
 254
 255                 r = dm_tm_new_block(ll->tm, &dm_sm_bitmap_validator, &b);
 256                 if (r < 0)
 257                         return r;
 258
 259                 idx.blocknr = cpu_to_le64(dm_block_location(b));
 260
 261                 r = dm_tm_unlock(ll->tm, b);
 262                 if (r < 0)
 263                         return r;
 264
 265                 idx.nr_free = cpu_to_le32(ll->entries_per_block);
 266                 idx.none_free_before = 0;
 267
 268                 r = ll->save_ie(ll, i, &idx);
 269                 if (r < 0)
 270                         return r;
 271         }
 272
 273         return 0;
 274 }
 275
 276 int sm_ll_lookup_bitmap(struct ll_disk *ll, dm_block_t b, uint32_t *result)
 277 {
 278         int r;
 279         dm_block_t index = b;
 280         struct disk_index_entry ie_disk;
 281         struct dm_block *blk;
 282
 283         b = do_div(index, ll->entries_per_block);
 284         r = ll->load_ie(ll, index, &ie_disk);
 285         if (r < 0)
 286                 return r;
 287
 288         r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr),
 289                             &dm_sm_bitmap_validator, &blk);
 290         if (r < 0)
 291                 return r;
 292
 293         *result = sm_lookup_bitmap(dm_bitmap_data(blk), b);
 294
 295         return dm_tm_unlock(ll->tm, blk);
 296 }
 297
 298 int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result)
 299 {
 300         __le32 le_rc;
 301         int r = sm_ll_lookup_bitmap(ll, b, result);
 302
 303         if (r)
 304                 return r;
 305
 306         if (*result != 3)
 307                 return r;
 308
 309         r = dm_btree_lookup(&ll->ref_count_info, ll->ref_count_root, &b, &le_rc);
 310         if (r < 0)
 311                 return r;
 312
 313         *result = le32_to_cpu(le_rc);
 314
 315         return r;
 316 }
 317
 318 int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
 319                           dm_block_t end, dm_block_t *result)
 320 {
 321         int r;
 322         struct disk_index_entry ie_disk;
 323         dm_block_t i, index_begin = begin;
 324         dm_block_t index_end = dm_sector_div_up(end, ll->entries_per_block);
 325
 326         /*
 327          * FIXME: Use shifts
 328          */
 329         begin = do_div(index_begin, ll->entries_per_block);
 330         end = do_div(end, ll->entries_per_block);
 331
 332         for (i = index_begin; i < index_end; i++, begin = 0) {
 333                 struct dm_block *blk;
 334                 unsigned position;
 335                 uint32_t bit_end;
 336
 337                 r = ll->load_ie(ll, i, &ie_disk);
 338                 if (r < 0)
 339                         return r;
 340
 341                 if (le32_to_cpu(ie_disk.nr_free) == 0)
 342                         continue;
 343
 344                 r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr),
 345                                     &dm_sm_bitmap_validator, &blk);
 346                 if (r < 0)
 347                         return r;
 348
 349                 bit_end = (i == index_end - 1) ?  end : ll->entries_per_block;
 350
 351                 r = sm_find_free(dm_bitmap_data(blk),
 352                                  max_t(unsigned, begin, le32_to_cpu(ie_disk.none_free_before)),
 353                                  bit_end, &position);
 354                 if (r == -ENOSPC) {
 355                         /*
 356                          * This might happen because we started searching
 357                          * part way through the bitmap.
 358                          */
 359                         dm_tm_unlock(ll->tm, blk);
 360                         continue;
 361
 362                 } else if (r < 0) {
 363                         dm_tm_unlock(ll->tm, blk);
 364                         return r;
 365                 }
 366
 367                 r = dm_tm_unlock(ll->tm, blk);
 368                 if (r < 0)
 369                         return r;
 370
 371                 *result = i * ll->entries_per_block + (dm_block_t) position;
 372                 return 0;
 373         }
 374
 375         return -ENOSPC;
 376 }
 377
 378 int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
 379                  uint32_t ref_count, enum allocation_event *ev)
 380 {
 381         int r;
 382         uint32_t bit, old;
 383         struct dm_block *nb;
 384         dm_block_t index = b;
 385         struct disk_index_entry ie_disk;
 386         void *bm_le;
 387         int inc;
 388
 389         bit = do_div(index, ll->entries_per_block);
 390         r = ll->load_ie(ll, index, &ie_disk);
 391         if (r < 0)
 392                 return r;
 393
 394         r = dm_tm_shadow_block(ll->tm, le64_to_cpu(ie_disk.blocknr),
 395                                &dm_sm_bitmap_validator, &nb, &inc);
 396         if (r < 0) {
 397                 DMERR("dm_tm_shadow_block() failed");
 398                 return r;
 399         }
 400         ie_disk.blocknr = cpu_to_le64(dm_block_location(nb));
 401
 402         bm_le = dm_bitmap_data(nb);
 403         old = sm_lookup_bitmap(bm_le, bit);
 404
 405         if (ref_count <= 2) {
 406                 sm_set_bitmap(bm_le, bit, ref_count);
 407
 408                 r = dm_tm_unlock(ll->tm, nb);
 409                 if (r < 0)
 410                         return r;
 411
 412                 if (old > 2) {
 413                         r = dm_btree_remove(&ll->ref_count_info,
 414                                             ll->ref_count_root,
 415                                             &b, &ll->ref_count_root);
 416                         if (r)
 417                                 return r;
 418                 }
 419
 420         } else {
 421                 __le32 le_rc = cpu_to_le32(ref_count);
 422
 423                 sm_set_bitmap(bm_le, bit, 3);
 424                 r = dm_tm_unlock(ll->tm, nb);
 425                 if (r < 0)
 426                         return r;
 427
 428                 __dm_bless_for_disk(&le_rc);
 429                 r = dm_btree_insert(&ll->ref_count_info, ll->ref_count_root,
 430                                     &b, &le_rc, &ll->ref_count_root);
 431                 if (r < 0) {
 432                         DMERR("ref count insert failed");
 433                         return r;
 434                 }
 435         }
 436
 437         if (ref_count && !old) {
 438                 *ev = SM_ALLOC;
 439                 ll->nr_allocated++;
 440                 ie_disk.nr_free = cpu_to_le32(le32_to_cpu(ie_disk.nr_free) - 1);
 441                 if (le32_to_cpu(ie_disk.none_free_before) == bit)
 442                         ie_disk.none_free_before = cpu_to_le32(bit + 1);
 443
 444         } else if (old && !ref_count) {
 445                 *ev = SM_FREE;
 446                 ll->nr_allocated--;
 447                 ie_disk.nr_free = cpu_to_le32(le32_to_cpu(ie_disk.nr_free) + 1);
 448                 ie_disk.none_free_before = cpu_to_le32(min(le32_to_cpu(ie_disk.none_free_before), bit));
 449         }
 450
 451         return ll->save_ie(ll, index, &ie_disk);
 452 }
 453
 454 int sm_ll_inc(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
 455 {
 456         int r;
 457         uint32_t rc;
 458
 459         r = sm_ll_lookup(ll, b, &rc);
 460         if (r)
 461                 return r;
 462
 463         return sm_ll_insert(ll, b, rc + 1, ev);
 464 }
 465
 466 int sm_ll_dec(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
 467 {
 468         int r;
 469         uint32_t rc;
 470
 471         r = sm_ll_lookup(ll, b, &rc);
 472         if (r)
 473                 return r;
 474
 475         if (!rc)
 476                 return -EINVAL;
 477
 478         return sm_ll_insert(ll, b, rc - 1, ev);
 479 }
 480
 481 int sm_ll_commit(struct ll_disk *ll)
 482 {
 483         return ll->commit(ll);
 484 }
 485
 486 /*----------------------------------------------------------------*/
 487
 488 static int metadata_ll_load_ie(struct ll_disk *ll, dm_block_t index,
 489                                struct disk_index_entry *ie)
 490 {
 491         memcpy(ie, ll->mi_le.index + index, sizeof(*ie));
 492         return 0;
 493 }
 494
 495 static int metadata_ll_save_ie(struct ll_disk *ll, dm_block_t index,
 496                                struct disk_index_entry *ie)
 497 {
 498         memcpy(ll->mi_le.index + index, ie, sizeof(*ie));
 499         return 0;
 500 }
 501
 502 static int metadata_ll_init_index(struct ll_disk *ll)
 503 {
 504         int r;
 505         struct dm_block *b;
 506
 507         r = dm_tm_new_block(ll->tm, &index_validator, &b);
 508         if (r < 0)
 509                 return r;
 510
 511         memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le));
 512         ll->bitmap_root = dm_block_location(b);
 513
 514         return dm_tm_unlock(ll->tm, b);
 515 }
 516
 517 static int metadata_ll_open(struct ll_disk *ll)
 518 {
 519         int r;
 520         struct dm_block *block;
 521
 522         r = dm_tm_read_lock(ll->tm, ll->bitmap_root,
 523                             &index_validator, &block);
 524         if (r)
 525                 return r;
 526
 527         memcpy(&ll->mi_le, dm_block_data(block), sizeof(ll->mi_le));
 528         return dm_tm_unlock(ll->tm, block);
 529 }
 530
 531 static dm_block_t metadata_ll_max_entries(struct ll_disk *ll)
 532 {
 533         return MAX_METADATA_BITMAPS;
 534 }
 535
 536 static int metadata_ll_commit(struct ll_disk *ll)
 537 {
 538         int r, inc;
 539         struct dm_block *b;
 540
 541         r = dm_tm_shadow_block(ll->tm, ll->bitmap_root, &index_validator, &b, &inc);
 542         if (r)
 543                 return r;
 544
 545         memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le));
 546         ll->bitmap_root = dm_block_location(b);
 547
 548         return dm_tm_unlock(ll->tm, b);
 549 }
 550
 551 int sm_ll_new_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm)
 552 {
 553         int r;
 554
 555         r = sm_ll_init(ll, tm);
 556         if (r < 0)
 557                 return r;
 558
 559         ll->load_ie = metadata_ll_load_ie;
 560         ll->save_ie = metadata_ll_save_ie;
 561         ll->init_index = metadata_ll_init_index;
 562         ll->open_index = metadata_ll_open;
 563         ll->max_entries = metadata_ll_max_entries;
 564         ll->commit = metadata_ll_commit;
 565
 566         ll->nr_blocks = 0;
 567         ll->nr_allocated = 0;
 568
 569         r = ll->init_index(ll);
 570         if (r < 0)
 571                 return r;
 572
 573         r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
 574         if (r < 0)
 575                 return r;
 576
 577         return 0;
 578 }
 579
 580 int sm_ll_open_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm,
 581                         void *root_le, size_t len)
 582 {
 583         int r;
 584         struct disk_sm_root *smr = root_le;
 585
 586         if (len < sizeof(struct disk_sm_root)) {
 587                 DMERR("sm_metadata root too small");
 588                 return -ENOMEM;
 589         }
 590
 591         r = sm_ll_init(ll, tm);
 592         if (r < 0)
 593                 return r;
 594
 595         ll->load_ie = metadata_ll_load_ie;
 596         ll->save_ie = metadata_ll_save_ie;
 597         ll->init_index = metadata_ll_init_index;
 598         ll->open_index = metadata_ll_open;
 599         ll->max_entries = metadata_ll_max_entries;
 600         ll->commit = metadata_ll_commit;
 601
 602         ll->nr_blocks = le64_to_cpu(smr->nr_blocks);
 603         ll->nr_allocated = le64_to_cpu(smr->nr_allocated);
 604         ll->bitmap_root = le64_to_cpu(smr->bitmap_root);
 605         ll->ref_count_root = le64_to_cpu(smr->ref_count_root);
 606
 607         return ll->open_index(ll);
 608 }
 609
 610 /*----------------------------------------------------------------*/
 611
 612 static int disk_ll_load_ie(struct ll_disk *ll, dm_block_t index,
 613                            struct disk_index_entry *ie)
 614 {
 615         return dm_btree_lookup(&ll->bitmap_info, ll->bitmap_root, &index, ie);
 616 }
 617
 618 static int disk_ll_save_ie(struct ll_disk *ll, dm_block_t index,
 619                            struct disk_index_entry *ie)
 620 {
 621         __dm_bless_for_disk(ie);
 622         return dm_btree_insert(&ll->bitmap_info, ll->bitmap_root,
 623                                &index, ie, &ll->bitmap_root);
 624 }
 625
 626 static int disk_ll_init_index(struct ll_disk *ll)
 627 {
 628         return dm_btree_empty(&ll->bitmap_info, &ll->bitmap_root);
 629 }
 630
 631 static int disk_ll_open(struct ll_disk *ll)
 632 {
 633         /* nothing to do */
 634         return 0;
 635 }
 636
 637 static dm_block_t disk_ll_max_entries(struct ll_disk *ll)
 638 {
 639         return -1ULL;
 640 }
 641
 642 static int disk_ll_commit(struct ll_disk *ll)
 643 {
 644         return 0;
 645 }
 646
 647 int sm_ll_new_disk(struct ll_disk *ll, struct dm_transaction_manager *tm)
 648 {
 649         int r;
 650
 651         r = sm_ll_init(ll, tm);
 652         if (r < 0)
 653                 return r;
 654
 655         ll->load_ie = disk_ll_load_ie;
 656         ll->save_ie = disk_ll_save_ie;
 657         ll->init_index = disk_ll_init_index;
 658         ll->open_index = disk_ll_open;
 659         ll->max_entries = disk_ll_max_entries;
 660         ll->commit = disk_ll_commit;
 661
 662         ll->nr_blocks = 0;
 663         ll->nr_allocated = 0;
 664
 665         r = ll->init_index(ll);
 666         if (r < 0)
 667                 return r;
 668
 669         r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
 670         if (r < 0)
 671                 return r;
 672
 673         return 0;
 674 }
 675
 676 int sm_ll_open_disk(struct ll_disk *ll, struct dm_transaction_manager *tm,
 677                     void *root_le, size_t len)
 678 {
 679         int r;
 680         struct disk_sm_root *smr = root_le;
 681
 682         if (len < sizeof(struct disk_sm_root)) {
 683                 DMERR("sm_metadata root too small");
 684                 return -ENOMEM;
 685         }
 686
 687         r = sm_ll_init(ll, tm);
 688         if (r < 0)
 689                 return r;
 690
 691         ll->load_ie = disk_ll_load_ie;
 692         ll->save_ie = disk_ll_save_ie;
 693         ll->init_index = disk_ll_init_index;
 694         ll->open_index = disk_ll_open;
 695         ll->max_entries = disk_ll_max_entries;
 696         ll->commit = disk_ll_commit;
 697
 698         ll->nr_blocks = le64_to_cpu(smr->nr_blocks);
 699         ll->nr_allocated = le64_to_cpu(smr->nr_allocated);
 700         ll->bitmap_root = le64_to_cpu(smr->bitmap_root);
 701         ll->ref_count_root = le64_to_cpu(smr->ref_count_root);
 702
 703         return ll->open_index(ll);
 704 }
 705
 706 /*----------------------------------------------------------------*/