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_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
  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 dm_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 dm_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
 109 static struct dm_block_validator dm_sm_bitmap_validator = {
 110         .name = "sm_bitmap",
 111         .prepare_for_write = dm_bitmap_prepare_for_write,
 112         .check = dm_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 dm_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                     dm_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         memset(ll, 0, sizeof(struct ll_disk));
 194
 195         ll->tm = tm;
 196
 197         ll->bitmap_info.tm = tm;
 198         ll->bitmap_info.levels = 1;
 199
 200         /*
 201          * Because the new bitmap blocks are created via a shadow
 202          * operation, the old entry has already had its reference count
 203          * decremented and we don't need the btree to do any bookkeeping.
 204          */
 205         ll->bitmap_info.value_type.size = sizeof(struct disk_index_entry);
 206         ll->bitmap_info.value_type.inc = NULL;
 207         ll->bitmap_info.value_type.dec = NULL;
 208         ll->bitmap_info.value_type.equal = NULL;
 209
 210         ll->ref_count_info.tm = tm;
 211         ll->ref_count_info.levels = 1;
 212         ll->ref_count_info.value_type.size = sizeof(uint32_t);
 213         ll->ref_count_info.value_type.inc = NULL;
 214         ll->ref_count_info.value_type.dec = NULL;
 215         ll->ref_count_info.value_type.equal = NULL;
 216
 217         ll->block_size = dm_bm_block_size(dm_tm_get_bm(tm));
 218
 219         if (ll->block_size > (1 << 30)) {
 220                 DMERR("block size too big to hold bitmaps");
 221                 return -EINVAL;
 222         }
 223
 224         ll->entries_per_block = (ll->block_size - sizeof(struct disk_bitmap_header)) *
 225                 ENTRIES_PER_BYTE;
 226         ll->nr_blocks = 0;
 227         ll->bitmap_root = 0;
 228         ll->ref_count_root = 0;
 229         ll->bitmap_index_changed = false;
 230
 231         return 0;
 232 }
 233
 234 int sm_ll_extend(struct ll_disk *ll, dm_block_t extra_blocks)
 235 {
 236         int r;
 237         dm_block_t i, nr_blocks, nr_indexes;
 238         unsigned old_blocks, blocks;
 239
 240         nr_blocks = ll->nr_blocks + extra_blocks;
 241         old_blocks = dm_sector_div_up(ll->nr_blocks, ll->entries_per_block);
 242         blocks = dm_sector_div_up(nr_blocks, ll->entries_per_block);
 243
 244         nr_indexes = dm_sector_div_up(nr_blocks, ll->entries_per_block);
 245         if (nr_indexes > ll->max_entries(ll)) {
 246                 DMERR("space map too large");
 247                 return -EINVAL;
 248         }
 249
 250         /*
 251          * We need to set this before the dm_tm_new_block() call below.
 252          */
 253         ll->nr_blocks = nr_blocks;
 254         for (i = old_blocks; i < blocks; i++) {
 255                 struct dm_block *b;
 256                 struct disk_index_entry idx;
 257
 258                 r = dm_tm_new_block(ll->tm, &dm_sm_bitmap_validator, &b);
 259                 if (r < 0)
 260                         return r;
 261
 262                 idx.blocknr = cpu_to_le64(dm_block_location(b));
 263
 264                 dm_tm_unlock(ll->tm, b);
 265
 266                 idx.nr_free = cpu_to_le32(ll->entries_per_block);
 267                 idx.none_free_before = 0;
 268
 269                 r = ll->save_ie(ll, i, &idx);
 270                 if (r < 0)
 271                         return r;
 272         }
 273
 274         return 0;
 275 }
 276
 277 int sm_ll_lookup_bitmap(struct ll_disk *ll, dm_block_t b, uint32_t *result)
 278 {
 279         int r;
 280         dm_block_t index = b;
 281         struct disk_index_entry ie_disk;
 282         struct dm_block *blk;
 283
 284         if (b >= ll->nr_blocks) {
 285                 DMERR_LIMIT("metadata block out of bounds");
 286                 return -EINVAL;
 287         }
 288
 289         b = do_div(index, ll->entries_per_block);
 290         r = ll->load_ie(ll, index, &ie_disk);
 291         if (r < 0)
 292                 return r;
 293
 294         r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr),
 295                             &dm_sm_bitmap_validator, &blk);
 296         if (r < 0)
 297                 return r;
 298
 299         *result = sm_lookup_bitmap(dm_bitmap_data(blk), b);
 300
 301         dm_tm_unlock(ll->tm, blk);
 302
 303         return 0;
 304 }
 305
 306 static int sm_ll_lookup_big_ref_count(struct ll_disk *ll, dm_block_t b,
 307                                       uint32_t *result)
 308 {
 309         __le32 le_rc;
 310         int r;
 311
 312         r = dm_btree_lookup(&ll->ref_count_info, ll->ref_count_root, &b, &le_rc);
 313         if (r < 0)
 314                 return r;
 315
 316         *result = le32_to_cpu(le_rc);
 317
 318         return r;
 319 }
 320
 321 int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result)
 322 {
 323         int r = sm_ll_lookup_bitmap(ll, b, result);
 324
 325         if (r)
 326                 return r;
 327
 328         if (*result != 3)
 329                 return r;
 330
 331         return sm_ll_lookup_big_ref_count(ll, b, result);
 332 }
 333
 334 int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin,
 335                           dm_block_t end, dm_block_t *result)
 336 {
 337         int r;
 338         struct disk_index_entry ie_disk;
 339         dm_block_t i, index_begin = begin;
 340         dm_block_t index_end = dm_sector_div_up(end, ll->entries_per_block);
 341
 342         /*
 343          * FIXME: Use shifts
 344          */
 345         begin = do_div(index_begin, ll->entries_per_block);
 346         end = do_div(end, ll->entries_per_block);
 347         if (end == 0)
 348                 end = ll->entries_per_block;
 349
 350         for (i = index_begin; i < index_end; i++, begin = 0) {
 351                 struct dm_block *blk;
 352                 unsigned position;
 353                 uint32_t bit_end;
 354
 355                 r = ll->load_ie(ll, i, &ie_disk);
 356                 if (r < 0)
 357                         return r;
 358
 359                 if (le32_to_cpu(ie_disk.nr_free) == 0)
 360                         continue;
 361
 362                 r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr),
 363                                     &dm_sm_bitmap_validator, &blk);
 364                 if (r < 0)
 365                         return r;
 366
 367                 bit_end = (i == index_end - 1) ?  end : ll->entries_per_block;
 368
 369                 r = sm_find_free(dm_bitmap_data(blk),
 370                                  max_t(unsigned, begin, le32_to_cpu(ie_disk.none_free_before)),
 371                                  bit_end, &position);
 372                 if (r == -ENOSPC) {
 373                         /*
 374                          * This might happen because we started searching
 375                          * part way through the bitmap.
 376                          */
 377                         dm_tm_unlock(ll->tm, blk);
 378                         continue;
 379                 }
 380
 381                 dm_tm_unlock(ll->tm, blk);
 382
 383                 *result = i * ll->entries_per_block + (dm_block_t) position;
 384                 return 0;
 385         }
 386
 387         return -ENOSPC;
 388 }
 389
 390 int sm_ll_find_common_free_block(struct ll_disk *old_ll, struct ll_disk *new_ll,
 391                                  dm_block_t begin, dm_block_t end, dm_block_t *b)
 392 {
 393         int r;
 394         uint32_t count;
 395
 396         do {
 397                 r = sm_ll_find_free_block(new_ll, begin, new_ll->nr_blocks, b);
 398                 if (r)
 399                         break;
 400
 401                 /* double check this block wasn't used in the old transaction */
 402                 if (*b >= old_ll->nr_blocks)
 403                         count = 0;
 404                 else {
 405                         r = sm_ll_lookup(old_ll, *b, &count);
 406                         if (r)
 407                                 break;
 408
 409                         if (count)
 410                                 begin = *b + 1;
 411                 }
 412         } while (count);
 413
 414         return r;
 415 }
 416
 417 static int sm_ll_mutate(struct ll_disk *ll, dm_block_t b,
 418                         int (*mutator)(void *context, uint32_t old, uint32_t *new),
 419                         void *context, enum allocation_event *ev)
 420 {
 421         int r;
 422         uint32_t bit, old, ref_count;
 423         struct dm_block *nb;
 424         dm_block_t index = b;
 425         struct disk_index_entry ie_disk;
 426         void *bm_le;
 427         int inc;
 428
 429         bit = do_div(index, ll->entries_per_block);
 430         r = ll->load_ie(ll, index, &ie_disk);
 431         if (r < 0)
 432                 return r;
 433
 434         r = dm_tm_shadow_block(ll->tm, le64_to_cpu(ie_disk.blocknr),
 435                                &dm_sm_bitmap_validator, &nb, &inc);
 436         if (r < 0) {
 437                 DMERR("dm_tm_shadow_block() failed");
 438                 return r;
 439         }
 440         ie_disk.blocknr = cpu_to_le64(dm_block_location(nb));
 441
 442         bm_le = dm_bitmap_data(nb);
 443         old = sm_lookup_bitmap(bm_le, bit);
 444
 445         if (old > 2) {
 446                 r = sm_ll_lookup_big_ref_count(ll, b, &old);
 447                 if (r < 0) {
 448                         dm_tm_unlock(ll->tm, nb);
 449                         return r;
 450                 }
 451         }
 452
 453         r = mutator(context, old, &ref_count);
 454         if (r) {
 455                 dm_tm_unlock(ll->tm, nb);
 456                 return r;
 457         }
 458
 459         if (ref_count <= 2) {
 460                 sm_set_bitmap(bm_le, bit, ref_count);
 461
 462                 dm_tm_unlock(ll->tm, nb);
 463
 464                 if (old > 2) {
 465                         r = dm_btree_remove(&ll->ref_count_info,
 466                                             ll->ref_count_root,
 467                                             &b, &ll->ref_count_root);
 468                         if (r)
 469                                 return r;
 470                 }
 471
 472         } else {
 473                 __le32 le_rc = cpu_to_le32(ref_count);
 474
 475                 sm_set_bitmap(bm_le, bit, 3);
 476                 dm_tm_unlock(ll->tm, nb);
 477
 478                 __dm_bless_for_disk(&le_rc);
 479                 r = dm_btree_insert(&ll->ref_count_info, ll->ref_count_root,
 480                                     &b, &le_rc, &ll->ref_count_root);
 481                 if (r < 0) {
 482                         DMERR("ref count insert failed");
 483                         return r;
 484                 }
 485         }
 486
 487         if (ref_count && !old) {
 488                 *ev = SM_ALLOC;
 489                 ll->nr_allocated++;
 490                 le32_add_cpu(&ie_disk.nr_free, -1);
 491                 if (le32_to_cpu(ie_disk.none_free_before) == bit)
 492                         ie_disk.none_free_before = cpu_to_le32(bit + 1);
 493
 494         } else if (old && !ref_count) {
 495                 *ev = SM_FREE;
 496                 ll->nr_allocated--;
 497                 le32_add_cpu(&ie_disk.nr_free, 1);
 498                 ie_disk.none_free_before = cpu_to_le32(min(le32_to_cpu(ie_disk.none_free_before), bit));
 499         } else
 500                 *ev = SM_NONE;
 501
 502         return ll->save_ie(ll, index, &ie_disk);
 503 }
 504
 505 static int set_ref_count(void *context, uint32_t old, uint32_t *new)
 506 {
 507         *new = *((uint32_t *) context);
 508         return 0;
 509 }
 510
 511 int sm_ll_insert(struct ll_disk *ll, dm_block_t b,
 512                  uint32_t ref_count, enum allocation_event *ev)
 513 {
 514         return sm_ll_mutate(ll, b, set_ref_count, &ref_count, ev);
 515 }
 516
 517 static int inc_ref_count(void *context, uint32_t old, uint32_t *new)
 518 {
 519         *new = old + 1;
 520         return 0;
 521 }
 522
 523 int sm_ll_inc(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
 524 {
 525         return sm_ll_mutate(ll, b, inc_ref_count, NULL, ev);
 526 }
 527
 528 static int dec_ref_count(void *context, uint32_t old, uint32_t *new)
 529 {
 530         if (!old) {
 531                 DMERR_LIMIT("unable to decrement a reference count below 0");
 532                 return -EINVAL;
 533         }
 534
 535         *new = old - 1;
 536         return 0;
 537 }
 538
 539 int sm_ll_dec(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev)
 540 {
 541         return sm_ll_mutate(ll, b, dec_ref_count, NULL, ev);
 542 }
 543
 544 int sm_ll_commit(struct ll_disk *ll)
 545 {
 546         int r = 0;
 547
 548         if (ll->bitmap_index_changed) {
 549                 r = ll->commit(ll);
 550                 if (!r)
 551                         ll->bitmap_index_changed = false;
 552         }
 553
 554         return r;
 555 }
 556
 557 /*----------------------------------------------------------------*/
 558
 559 static int metadata_ll_load_ie(struct ll_disk *ll, dm_block_t index,
 560                                struct disk_index_entry *ie)
 561 {
 562         memcpy(ie, ll->mi_le.index + index, sizeof(*ie));
 563         return 0;
 564 }
 565
 566 static int metadata_ll_save_ie(struct ll_disk *ll, dm_block_t index,
 567                                struct disk_index_entry *ie)
 568 {
 569         ll->bitmap_index_changed = true;
 570         memcpy(ll->mi_le.index + index, ie, sizeof(*ie));
 571         return 0;
 572 }
 573
 574 static int metadata_ll_init_index(struct ll_disk *ll)
 575 {
 576         int r;
 577         struct dm_block *b;
 578
 579         r = dm_tm_new_block(ll->tm, &index_validator, &b);
 580         if (r < 0)
 581                 return r;
 582
 583         ll->bitmap_root = dm_block_location(b);
 584
 585         dm_tm_unlock(ll->tm, b);
 586
 587         return 0;
 588 }
 589
 590 static int metadata_ll_open(struct ll_disk *ll)
 591 {
 592         int r;
 593         struct dm_block *block;
 594
 595         r = dm_tm_read_lock(ll->tm, ll->bitmap_root,
 596                             &index_validator, &block);
 597         if (r)
 598                 return r;
 599
 600         memcpy(&ll->mi_le, dm_block_data(block), sizeof(ll->mi_le));
 601         dm_tm_unlock(ll->tm, block);
 602
 603         return 0;
 604 }
 605
 606 static dm_block_t metadata_ll_max_entries(struct ll_disk *ll)
 607 {
 608         return MAX_METADATA_BITMAPS;
 609 }
 610
 611 static int metadata_ll_commit(struct ll_disk *ll)
 612 {
 613         int r, inc;
 614         struct dm_block *b;
 615
 616         r = dm_tm_shadow_block(ll->tm, ll->bitmap_root, &index_validator, &b, &inc);
 617         if (r)
 618                 return r;
 619
 620         memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le));
 621         ll->bitmap_root = dm_block_location(b);
 622
 623         dm_tm_unlock(ll->tm, b);
 624
 625         return 0;
 626 }
 627
 628 int sm_ll_new_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm)
 629 {
 630         int r;
 631
 632         r = sm_ll_init(ll, tm);
 633         if (r < 0)
 634                 return r;
 635
 636         ll->load_ie = metadata_ll_load_ie;
 637         ll->save_ie = metadata_ll_save_ie;
 638         ll->init_index = metadata_ll_init_index;
 639         ll->open_index = metadata_ll_open;
 640         ll->max_entries = metadata_ll_max_entries;
 641         ll->commit = metadata_ll_commit;
 642
 643         ll->nr_blocks = 0;
 644         ll->nr_allocated = 0;
 645
 646         r = ll->init_index(ll);
 647         if (r < 0)
 648                 return r;
 649
 650         r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
 651         if (r < 0)
 652                 return r;
 653
 654         return 0;
 655 }
 656
 657 int sm_ll_open_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm,
 658                         void *root_le, size_t len)
 659 {
 660         int r;
 661         struct disk_sm_root smr;
 662
 663         if (len < sizeof(struct disk_sm_root)) {
 664                 DMERR("sm_metadata root too small");
 665                 return -ENOMEM;
 666         }
 667
 668         /*
 669          * We don't know the alignment of the root_le buffer, so need to
 670          * copy into a new structure.
 671          */
 672         memcpy(&smr, root_le, sizeof(smr));
 673
 674         r = sm_ll_init(ll, tm);
 675         if (r < 0)
 676                 return r;
 677
 678         ll->load_ie = metadata_ll_load_ie;
 679         ll->save_ie = metadata_ll_save_ie;
 680         ll->init_index = metadata_ll_init_index;
 681         ll->open_index = metadata_ll_open;
 682         ll->max_entries = metadata_ll_max_entries;
 683         ll->commit = metadata_ll_commit;
 684
 685         ll->nr_blocks = le64_to_cpu(smr.nr_blocks);
 686         ll->nr_allocated = le64_to_cpu(smr.nr_allocated);
 687         ll->bitmap_root = le64_to_cpu(smr.bitmap_root);
 688         ll->ref_count_root = le64_to_cpu(smr.ref_count_root);
 689
 690         return ll->open_index(ll);
 691 }
 692
 693 /*----------------------------------------------------------------*/
 694
 695 static int disk_ll_load_ie(struct ll_disk *ll, dm_block_t index,
 696                            struct disk_index_entry *ie)
 697 {
 698         return dm_btree_lookup(&ll->bitmap_info, ll->bitmap_root, &index, ie);
 699 }
 700
 701 static int disk_ll_save_ie(struct ll_disk *ll, dm_block_t index,
 702                            struct disk_index_entry *ie)
 703 {
 704         __dm_bless_for_disk(ie);
 705         return dm_btree_insert(&ll->bitmap_info, ll->bitmap_root,
 706                                &index, ie, &ll->bitmap_root);
 707 }
 708
 709 static int disk_ll_init_index(struct ll_disk *ll)
 710 {
 711         return dm_btree_empty(&ll->bitmap_info, &ll->bitmap_root);
 712 }
 713
 714 static int disk_ll_open(struct ll_disk *ll)
 715 {
 716         /* nothing to do */
 717         return 0;
 718 }
 719
 720 static dm_block_t disk_ll_max_entries(struct ll_disk *ll)
 721 {
 722         return -1ULL;
 723 }
 724
 725 static int disk_ll_commit(struct ll_disk *ll)
 726 {
 727         return 0;
 728 }
 729
 730 int sm_ll_new_disk(struct ll_disk *ll, struct dm_transaction_manager *tm)
 731 {
 732         int r;
 733
 734         r = sm_ll_init(ll, tm);
 735         if (r < 0)
 736                 return r;
 737
 738         ll->load_ie = disk_ll_load_ie;
 739         ll->save_ie = disk_ll_save_ie;
 740         ll->init_index = disk_ll_init_index;
 741         ll->open_index = disk_ll_open;
 742         ll->max_entries = disk_ll_max_entries;
 743         ll->commit = disk_ll_commit;
 744
 745         ll->nr_blocks = 0;
 746         ll->nr_allocated = 0;
 747
 748         r = ll->init_index(ll);
 749         if (r < 0)
 750                 return r;
 751
 752         r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root);
 753         if (r < 0)
 754                 return r;
 755
 756         return 0;
 757 }
 758
 759 int sm_ll_open_disk(struct ll_disk *ll, struct dm_transaction_manager *tm,
 760                     void *root_le, size_t len)
 761 {
 762         int r;
 763         struct disk_sm_root *smr = root_le;
 764
 765         if (len < sizeof(struct disk_sm_root)) {
 766                 DMERR("sm_metadata root too small");
 767                 return -ENOMEM;
 768         }
 769
 770         r = sm_ll_init(ll, tm);
 771         if (r < 0)
 772                 return r;
 773
 774         ll->load_ie = disk_ll_load_ie;
 775         ll->save_ie = disk_ll_save_ie;
 776         ll->init_index = disk_ll_init_index;
 777         ll->open_index = disk_ll_open;
 778         ll->max_entries = disk_ll_max_entries;
 779         ll->commit = disk_ll_commit;
 780
 781         ll->nr_blocks = le64_to_cpu(smr->nr_blocks);
 782         ll->nr_allocated = le64_to_cpu(smr->nr_allocated);
 783         ll->bitmap_root = le64_to_cpu(smr->bitmap_root);
 784         ll->ref_count_root = le64_to_cpu(smr->ref_count_root);
 785
 786         return ll->open_index(ll);
 787 }
 788
 789 /*----------------------------------------------------------------*/