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 b = do_div(index, ll->entries_per_block); 285 r = ll->load_ie(ll, index, &ie_disk); 286 if (r < 0) 287 return r; 288 289 r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr), 290 &dm_sm_bitmap_validator, &blk); 291 if (r < 0) 292 return r; 293 294 *result = sm_lookup_bitmap(dm_bitmap_data(blk), b); 295 296 dm_tm_unlock(ll->tm, blk); 297 298 return 0; 299 } 300 301 static int sm_ll_lookup_big_ref_count(struct ll_disk *ll, dm_block_t b, 302 uint32_t *result) 303 { 304 __le32 le_rc; 305 int r; 306 307 r = dm_btree_lookup(&ll->ref_count_info, ll->ref_count_root, &b, &le_rc); 308 if (r < 0) 309 return r; 310 311 *result = le32_to_cpu(le_rc); 312 313 return r; 314 } 315 316 int sm_ll_lookup(struct ll_disk *ll, dm_block_t b, uint32_t *result) 317 { 318 int r = sm_ll_lookup_bitmap(ll, b, result); 319 320 if (r) 321 return r; 322 323 if (*result != 3) 324 return r; 325 326 return sm_ll_lookup_big_ref_count(ll, b, result); 327 } 328 329 int sm_ll_find_free_block(struct ll_disk *ll, dm_block_t begin, 330 dm_block_t end, dm_block_t *result) 331 { 332 int r; 333 struct disk_index_entry ie_disk; 334 dm_block_t i, index_begin = begin; 335 dm_block_t index_end = dm_sector_div_up(end, ll->entries_per_block); 336 337 /* 338 * FIXME: Use shifts 339 */ 340 begin = do_div(index_begin, ll->entries_per_block); 341 end = do_div(end, ll->entries_per_block); 342 343 for (i = index_begin; i < index_end; i++, begin = 0) { 344 struct dm_block *blk; 345 unsigned position; 346 uint32_t bit_end; 347 348 r = ll->load_ie(ll, i, &ie_disk); 349 if (r < 0) 350 return r; 351 352 if (le32_to_cpu(ie_disk.nr_free) == 0) 353 continue; 354 355 r = dm_tm_read_lock(ll->tm, le64_to_cpu(ie_disk.blocknr), 356 &dm_sm_bitmap_validator, &blk); 357 if (r < 0) 358 return r; 359 360 bit_end = (i == index_end - 1) ? end : ll->entries_per_block; 361 362 r = sm_find_free(dm_bitmap_data(blk), 363 max_t(unsigned, begin, le32_to_cpu(ie_disk.none_free_before)), 364 bit_end, &position); 365 if (r == -ENOSPC) { 366 /* 367 * This might happen because we started searching 368 * part way through the bitmap. 369 */ 370 dm_tm_unlock(ll->tm, blk); 371 continue; 372 373 } else if (r < 0) { 374 dm_tm_unlock(ll->tm, blk); 375 return r; 376 } 377 378 dm_tm_unlock(ll->tm, blk); 379 380 *result = i * ll->entries_per_block + (dm_block_t) position; 381 return 0; 382 } 383 384 return -ENOSPC; 385 } 386 387 static int sm_ll_mutate(struct ll_disk *ll, dm_block_t b, 388 int (*mutator)(void *context, uint32_t old, uint32_t *new), 389 void *context, enum allocation_event *ev) 390 { 391 int r; 392 uint32_t bit, old, ref_count; 393 struct dm_block *nb; 394 dm_block_t index = b; 395 struct disk_index_entry ie_disk; 396 void *bm_le; 397 int inc; 398 399 bit = do_div(index, ll->entries_per_block); 400 r = ll->load_ie(ll, index, &ie_disk); 401 if (r < 0) 402 return r; 403 404 r = dm_tm_shadow_block(ll->tm, le64_to_cpu(ie_disk.blocknr), 405 &dm_sm_bitmap_validator, &nb, &inc); 406 if (r < 0) { 407 DMERR("dm_tm_shadow_block() failed"); 408 return r; 409 } 410 ie_disk.blocknr = cpu_to_le64(dm_block_location(nb)); 411 412 bm_le = dm_bitmap_data(nb); 413 old = sm_lookup_bitmap(bm_le, bit); 414 415 if (old > 2) { 416 r = sm_ll_lookup_big_ref_count(ll, b, &old); 417 if (r < 0) { 418 dm_tm_unlock(ll->tm, nb); 419 return r; 420 } 421 } 422 423 r = mutator(context, old, &ref_count); 424 if (r) { 425 dm_tm_unlock(ll->tm, nb); 426 return r; 427 } 428 429 if (ref_count <= 2) { 430 sm_set_bitmap(bm_le, bit, ref_count); 431 432 dm_tm_unlock(ll->tm, nb); 433 434 if (old > 2) { 435 r = dm_btree_remove(&ll->ref_count_info, 436 ll->ref_count_root, 437 &b, &ll->ref_count_root); 438 if (r) 439 return r; 440 } 441 442 } else { 443 __le32 le_rc = cpu_to_le32(ref_count); 444 445 sm_set_bitmap(bm_le, bit, 3); 446 dm_tm_unlock(ll->tm, nb); 447 448 __dm_bless_for_disk(&le_rc); 449 r = dm_btree_insert(&ll->ref_count_info, ll->ref_count_root, 450 &b, &le_rc, &ll->ref_count_root); 451 if (r < 0) { 452 DMERR("ref count insert failed"); 453 return r; 454 } 455 } 456 457 if (ref_count && !old) { 458 *ev = SM_ALLOC; 459 ll->nr_allocated++; 460 le32_add_cpu(&ie_disk.nr_free, -1); 461 if (le32_to_cpu(ie_disk.none_free_before) == bit) 462 ie_disk.none_free_before = cpu_to_le32(bit + 1); 463 464 } else if (old && !ref_count) { 465 *ev = SM_FREE; 466 ll->nr_allocated--; 467 le32_add_cpu(&ie_disk.nr_free, 1); 468 ie_disk.none_free_before = cpu_to_le32(min(le32_to_cpu(ie_disk.none_free_before), bit)); 469 } else 470 *ev = SM_NONE; 471 472 return ll->save_ie(ll, index, &ie_disk); 473 } 474 475 static int set_ref_count(void *context, uint32_t old, uint32_t *new) 476 { 477 *new = *((uint32_t *) context); 478 return 0; 479 } 480 481 int sm_ll_insert(struct ll_disk *ll, dm_block_t b, 482 uint32_t ref_count, enum allocation_event *ev) 483 { 484 return sm_ll_mutate(ll, b, set_ref_count, &ref_count, ev); 485 } 486 487 static int inc_ref_count(void *context, uint32_t old, uint32_t *new) 488 { 489 *new = old + 1; 490 return 0; 491 } 492 493 int sm_ll_inc(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev) 494 { 495 return sm_ll_mutate(ll, b, inc_ref_count, NULL, ev); 496 } 497 498 static int dec_ref_count(void *context, uint32_t old, uint32_t *new) 499 { 500 if (!old) { 501 DMERR_LIMIT("unable to decrement a reference count below 0"); 502 return -EINVAL; 503 } 504 505 *new = old - 1; 506 return 0; 507 } 508 509 int sm_ll_dec(struct ll_disk *ll, dm_block_t b, enum allocation_event *ev) 510 { 511 return sm_ll_mutate(ll, b, dec_ref_count, NULL, ev); 512 } 513 514 int sm_ll_commit(struct ll_disk *ll) 515 { 516 int r = 0; 517 518 if (ll->bitmap_index_changed) { 519 r = ll->commit(ll); 520 if (!r) 521 ll->bitmap_index_changed = false; 522 } 523 524 return r; 525 } 526 527 /*----------------------------------------------------------------*/ 528 529 static int metadata_ll_load_ie(struct ll_disk *ll, dm_block_t index, 530 struct disk_index_entry *ie) 531 { 532 memcpy(ie, ll->mi_le.index + index, sizeof(*ie)); 533 return 0; 534 } 535 536 static int metadata_ll_save_ie(struct ll_disk *ll, dm_block_t index, 537 struct disk_index_entry *ie) 538 { 539 ll->bitmap_index_changed = true; 540 memcpy(ll->mi_le.index + index, ie, sizeof(*ie)); 541 return 0; 542 } 543 544 static int metadata_ll_init_index(struct ll_disk *ll) 545 { 546 int r; 547 struct dm_block *b; 548 549 r = dm_tm_new_block(ll->tm, &index_validator, &b); 550 if (r < 0) 551 return r; 552 553 ll->bitmap_root = dm_block_location(b); 554 555 dm_tm_unlock(ll->tm, b); 556 557 return 0; 558 } 559 560 static int metadata_ll_open(struct ll_disk *ll) 561 { 562 int r; 563 struct dm_block *block; 564 565 r = dm_tm_read_lock(ll->tm, ll->bitmap_root, 566 &index_validator, &block); 567 if (r) 568 return r; 569 570 memcpy(&ll->mi_le, dm_block_data(block), sizeof(ll->mi_le)); 571 dm_tm_unlock(ll->tm, block); 572 573 return 0; 574 } 575 576 static dm_block_t metadata_ll_max_entries(struct ll_disk *ll) 577 { 578 return MAX_METADATA_BITMAPS; 579 } 580 581 static int metadata_ll_commit(struct ll_disk *ll) 582 { 583 int r, inc; 584 struct dm_block *b; 585 586 r = dm_tm_shadow_block(ll->tm, ll->bitmap_root, &index_validator, &b, &inc); 587 if (r) 588 return r; 589 590 memcpy(dm_block_data(b), &ll->mi_le, sizeof(ll->mi_le)); 591 ll->bitmap_root = dm_block_location(b); 592 593 dm_tm_unlock(ll->tm, b); 594 595 return 0; 596 } 597 598 int sm_ll_new_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm) 599 { 600 int r; 601 602 r = sm_ll_init(ll, tm); 603 if (r < 0) 604 return r; 605 606 ll->load_ie = metadata_ll_load_ie; 607 ll->save_ie = metadata_ll_save_ie; 608 ll->init_index = metadata_ll_init_index; 609 ll->open_index = metadata_ll_open; 610 ll->max_entries = metadata_ll_max_entries; 611 ll->commit = metadata_ll_commit; 612 613 ll->nr_blocks = 0; 614 ll->nr_allocated = 0; 615 616 r = ll->init_index(ll); 617 if (r < 0) 618 return r; 619 620 r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root); 621 if (r < 0) 622 return r; 623 624 return 0; 625 } 626 627 int sm_ll_open_metadata(struct ll_disk *ll, struct dm_transaction_manager *tm, 628 void *root_le, size_t len) 629 { 630 int r; 631 struct disk_sm_root smr; 632 633 if (len < sizeof(struct disk_sm_root)) { 634 DMERR("sm_metadata root too small"); 635 return -ENOMEM; 636 } 637 638 /* 639 * We don't know the alignment of the root_le buffer, so need to 640 * copy into a new structure. 641 */ 642 memcpy(&smr, root_le, sizeof(smr)); 643 644 r = sm_ll_init(ll, tm); 645 if (r < 0) 646 return r; 647 648 ll->load_ie = metadata_ll_load_ie; 649 ll->save_ie = metadata_ll_save_ie; 650 ll->init_index = metadata_ll_init_index; 651 ll->open_index = metadata_ll_open; 652 ll->max_entries = metadata_ll_max_entries; 653 ll->commit = metadata_ll_commit; 654 655 ll->nr_blocks = le64_to_cpu(smr.nr_blocks); 656 ll->nr_allocated = le64_to_cpu(smr.nr_allocated); 657 ll->bitmap_root = le64_to_cpu(smr.bitmap_root); 658 ll->ref_count_root = le64_to_cpu(smr.ref_count_root); 659 660 return ll->open_index(ll); 661 } 662 663 /*----------------------------------------------------------------*/ 664 665 static int disk_ll_load_ie(struct ll_disk *ll, dm_block_t index, 666 struct disk_index_entry *ie) 667 { 668 return dm_btree_lookup(&ll->bitmap_info, ll->bitmap_root, &index, ie); 669 } 670 671 static int disk_ll_save_ie(struct ll_disk *ll, dm_block_t index, 672 struct disk_index_entry *ie) 673 { 674 __dm_bless_for_disk(ie); 675 return dm_btree_insert(&ll->bitmap_info, ll->bitmap_root, 676 &index, ie, &ll->bitmap_root); 677 } 678 679 static int disk_ll_init_index(struct ll_disk *ll) 680 { 681 return dm_btree_empty(&ll->bitmap_info, &ll->bitmap_root); 682 } 683 684 static int disk_ll_open(struct ll_disk *ll) 685 { 686 /* nothing to do */ 687 return 0; 688 } 689 690 static dm_block_t disk_ll_max_entries(struct ll_disk *ll) 691 { 692 return -1ULL; 693 } 694 695 static int disk_ll_commit(struct ll_disk *ll) 696 { 697 return 0; 698 } 699 700 int sm_ll_new_disk(struct ll_disk *ll, struct dm_transaction_manager *tm) 701 { 702 int r; 703 704 r = sm_ll_init(ll, tm); 705 if (r < 0) 706 return r; 707 708 ll->load_ie = disk_ll_load_ie; 709 ll->save_ie = disk_ll_save_ie; 710 ll->init_index = disk_ll_init_index; 711 ll->open_index = disk_ll_open; 712 ll->max_entries = disk_ll_max_entries; 713 ll->commit = disk_ll_commit; 714 715 ll->nr_blocks = 0; 716 ll->nr_allocated = 0; 717 718 r = ll->init_index(ll); 719 if (r < 0) 720 return r; 721 722 r = dm_btree_empty(&ll->ref_count_info, &ll->ref_count_root); 723 if (r < 0) 724 return r; 725 726 return 0; 727 } 728 729 int sm_ll_open_disk(struct ll_disk *ll, struct dm_transaction_manager *tm, 730 void *root_le, size_t len) 731 { 732 int r; 733 struct disk_sm_root *smr = root_le; 734 735 if (len < sizeof(struct disk_sm_root)) { 736 DMERR("sm_metadata root too small"); 737 return -ENOMEM; 738 } 739 740 r = sm_ll_init(ll, tm); 741 if (r < 0) 742 return r; 743 744 ll->load_ie = disk_ll_load_ie; 745 ll->save_ie = disk_ll_save_ie; 746 ll->init_index = disk_ll_init_index; 747 ll->open_index = disk_ll_open; 748 ll->max_entries = disk_ll_max_entries; 749 ll->commit = disk_ll_commit; 750 751 ll->nr_blocks = le64_to_cpu(smr->nr_blocks); 752 ll->nr_allocated = le64_to_cpu(smr->nr_allocated); 753 ll->bitmap_root = le64_to_cpu(smr->bitmap_root); 754 ll->ref_count_root = le64_to_cpu(smr->ref_count_root); 755 756 return ll->open_index(ll); 757 } 758 759 /*----------------------------------------------------------------*/ 760