drivers/md/persistent-data/dm-space-map-metadata.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.h"
   8 #include "dm-space-map-common.h"
   9 #include "dm-space-map-metadata.h"
  10
  11 #include <linux/list.h>
  12 #include <linux/slab.h>
  13 #include <linux/device-mapper.h>
  14
  15 #define DM_MSG_PREFIX "space map metadata"
  16
  17 /*----------------------------------------------------------------*/
  18
  19 /*
  20  * An edge triggered threshold.
  21  */
  22 struct threshold {
  23         bool threshold_set;
  24         bool value_set;
  25         dm_block_t threshold;
  26         dm_block_t current_value;
  27         dm_sm_threshold_fn fn;
  28         void *context;
  29 };
  30
  31 static void threshold_init(struct threshold *t)
  32 {
  33         t->threshold_set = false;
  34         t->value_set = false;
  35 }
  36
  37 static void set_threshold(struct threshold *t, dm_block_t value,
  38                           dm_sm_threshold_fn fn, void *context)
  39 {
  40         t->threshold_set = true;
  41         t->threshold = value;
  42         t->fn = fn;
  43         t->context = context;
  44 }
  45
  46 static bool below_threshold(struct threshold *t, dm_block_t value)
  47 {
  48         return t->threshold_set && value <= t->threshold;
  49 }
  50
  51 static bool threshold_already_triggered(struct threshold *t)
  52 {
  53         return t->value_set && below_threshold(t, t->current_value);
  54 }
  55
  56 static void check_threshold(struct threshold *t, dm_block_t value)
  57 {
  58         if (below_threshold(t, value) &&
  59             !threshold_already_triggered(t))
  60                 t->fn(t->context);
  61
  62         t->value_set = true;
  63         t->current_value = value;
  64 }
  65
  66 /*----------------------------------------------------------------*/
  67
  68 /*
  69  * Space map interface.
  70  *
  71  * The low level disk format is written using the standard btree and
  72  * transaction manager.  This means that performing disk operations may
  73  * cause us to recurse into the space map in order to allocate new blocks.
  74  * For this reason we have a pool of pre-allocated blocks large enough to
  75  * service any metadata_ll_disk operation.
  76  */
  77
  78 /*
  79  * FIXME: we should calculate this based on the size of the device.
  80  * Only the metadata space map needs this functionality.
  81  */
  82 #define MAX_RECURSIVE_ALLOCATIONS 1024
  83
  84 enum block_op_type {
  85         BOP_INC,
  86         BOP_DEC
  87 };
  88
  89 struct block_op {
  90         enum block_op_type type;
  91         dm_block_t block;
  92 };
  93
  94 struct bop_ring_buffer {
  95         unsigned begin;
  96         unsigned end;
  97         struct block_op bops[MAX_RECURSIVE_ALLOCATIONS + 1];
  98 };
  99
 100 static void brb_init(struct bop_ring_buffer *brb)
 101 {
 102         brb->begin = 0;
 103         brb->end = 0;
 104 }
 105
 106 static bool brb_empty(struct bop_ring_buffer *brb)
 107 {
 108         return brb->begin == brb->end;
 109 }
 110
 111 static unsigned brb_next(struct bop_ring_buffer *brb, unsigned old)
 112 {
 113         unsigned r = old + 1;
 114         return (r >= (sizeof(brb->bops) / sizeof(*brb->bops))) ? 0 : r;
 115 }
 116
 117 static int brb_push(struct bop_ring_buffer *brb,
 118                     enum block_op_type type, dm_block_t b)
 119 {
 120         struct block_op *bop;
 121         unsigned next = brb_next(brb, brb->end);
 122
 123         /*
 124          * We don't allow the last bop to be filled, this way we can
 125          * differentiate between full and empty.
 126          */
 127         if (next == brb->begin)
 128                 return -ENOMEM;
 129
 130         bop = brb->bops + brb->end;
 131         bop->type = type;
 132         bop->block = b;
 133
 134         brb->end = next;
 135
 136         return 0;
 137 }
 138
 139 static int brb_peek(struct bop_ring_buffer *brb, struct block_op *result)
 140 {
 141         struct block_op *bop;
 142
 143         if (brb_empty(brb))
 144                 return -ENODATA;
 145
 146         bop = brb->bops + brb->begin;
 147         result->type = bop->type;
 148         result->block = bop->block;
 149
 150         return 0;
 151 }
 152
 153 static int brb_pop(struct bop_ring_buffer *brb)
 154 {
 155         struct block_op *bop;
 156
 157         if (brb_empty(brb))
 158                 return -ENODATA;
 159
 160         bop = brb->bops + brb->begin;
 161         brb->begin = brb_next(brb, brb->begin);
 162
 163         return 0;
 164 }
 165
 166 /*----------------------------------------------------------------*/
 167
 168 struct sm_metadata {
 169         struct dm_space_map sm;
 170
 171         struct ll_disk ll;
 172         struct ll_disk old_ll;
 173
 174         dm_block_t begin;
 175
 176         unsigned recursion_count;
 177         unsigned allocated_this_transaction;
 178         struct bop_ring_buffer uncommitted;
 179
 180         struct threshold threshold;
 181 };
 182
 183 static int add_bop(struct sm_metadata *smm, enum block_op_type type, dm_block_t b)
 184 {
 185         int r = brb_push(&smm->uncommitted, type, b);
 186
 187         if (r) {
 188                 DMERR("too many recursive allocations");
 189                 return -ENOMEM;
 190         }
 191
 192         return 0;
 193 }
 194
 195 static int commit_bop(struct sm_metadata *smm, struct block_op *op)
 196 {
 197         int r = 0;
 198         enum allocation_event ev;
 199
 200         switch (op->type) {
 201         case BOP_INC:
 202                 r = sm_ll_inc(&smm->ll, op->block, &ev);
 203                 break;
 204
 205         case BOP_DEC:
 206                 r = sm_ll_dec(&smm->ll, op->block, &ev);
 207                 break;
 208         }
 209
 210         return r;
 211 }
 212
 213 static void in(struct sm_metadata *smm)
 214 {
 215         smm->recursion_count++;
 216 }
 217
 218 static int apply_bops(struct sm_metadata *smm)
 219 {
 220         int r = 0;
 221
 222         while (!brb_empty(&smm->uncommitted)) {
 223                 struct block_op bop;
 224
 225                 r = brb_peek(&smm->uncommitted, &bop);
 226                 if (r) {
 227                         DMERR("bug in bop ring buffer");
 228                         break;
 229                 }
 230
 231                 r = commit_bop(smm, &bop);
 232                 if (r)
 233                         break;
 234
 235                 brb_pop(&smm->uncommitted);
 236         }
 237
 238         return r;
 239 }
 240
 241 static int out(struct sm_metadata *smm)
 242 {
 243         int r = 0;
 244
 245         /*
 246          * If we're not recursing then very bad things are happening.
 247          */
 248         if (!smm->recursion_count) {
 249                 DMERR("lost track of recursion depth");
 250                 return -ENOMEM;
 251         }
 252
 253         if (smm->recursion_count == 1)
 254                 apply_bops(smm);
 255
 256         smm->recursion_count--;
 257
 258         return r;
 259 }
 260
 261 /*
 262  * When using the out() function above, we often want to combine an error
 263  * code for the operation run in the recursive context with that from
 264  * out().
 265  */
 266 static int combine_errors(int r1, int r2)
 267 {
 268         return r1 ? r1 : r2;
 269 }
 270
 271 static int recursing(struct sm_metadata *smm)
 272 {
 273         return smm->recursion_count;
 274 }
 275
 276 static void sm_metadata_destroy(struct dm_space_map *sm)
 277 {
 278         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 279
 280         kfree(smm);
 281 }
 282
 283 static int sm_metadata_get_nr_blocks(struct dm_space_map *sm, dm_block_t *count)
 284 {
 285         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 286
 287         *count = smm->ll.nr_blocks;
 288
 289         return 0;
 290 }
 291
 292 static int sm_metadata_get_nr_free(struct dm_space_map *sm, dm_block_t *count)
 293 {
 294         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 295
 296         *count = smm->old_ll.nr_blocks - smm->old_ll.nr_allocated -
 297                  smm->allocated_this_transaction;
 298
 299         return 0;
 300 }
 301
 302 static int sm_metadata_get_count(struct dm_space_map *sm, dm_block_t b,
 303                                  uint32_t *result)
 304 {
 305         int r;
 306         unsigned i;
 307         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 308         unsigned adjustment = 0;
 309
 310         /*
 311          * We may have some uncommitted adjustments to add.  This list
 312          * should always be really short.
 313          */
 314         for (i = smm->uncommitted.begin;
 315              i != smm->uncommitted.end;
 316              i = brb_next(&smm->uncommitted, i)) {
 317                 struct block_op *op = smm->uncommitted.bops + i;
 318
 319                 if (op->block != b)
 320                         continue;
 321
 322                 switch (op->type) {
 323                 case BOP_INC:
 324                         adjustment++;
 325                         break;
 326
 327                 case BOP_DEC:
 328                         adjustment--;
 329                         break;
 330                 }
 331         }
 332
 333         r = sm_ll_lookup(&smm->ll, b, result);
 334         if (r)
 335                 return r;
 336
 337         *result += adjustment;
 338
 339         return 0;
 340 }
 341
 342 static int sm_metadata_count_is_more_than_one(struct dm_space_map *sm,
 343                                               dm_block_t b, int *result)
 344 {
 345         int r, adjustment = 0;
 346         unsigned i;
 347         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 348         uint32_t rc;
 349
 350         /*
 351          * We may have some uncommitted adjustments to add.  This list
 352          * should always be really short.
 353          */
 354         for (i = smm->uncommitted.begin;
 355              i != smm->uncommitted.end;
 356              i = brb_next(&smm->uncommitted, i)) {
 357
 358                 struct block_op *op = smm->uncommitted.bops + i;
 359
 360                 if (op->block != b)
 361                         continue;
 362
 363                 switch (op->type) {
 364                 case BOP_INC:
 365                         adjustment++;
 366                         break;
 367
 368                 case BOP_DEC:
 369                         adjustment--;
 370                         break;
 371                 }
 372         }
 373
 374         if (adjustment > 1) {
 375                 *result = 1;
 376                 return 0;
 377         }
 378
 379         r = sm_ll_lookup_bitmap(&smm->ll, b, &rc);
 380         if (r)
 381                 return r;
 382
 383         if (rc == 3)
 384                 /*
 385                  * We err on the side of caution, and always return true.
 386                  */
 387                 *result = 1;
 388         else
 389                 *result = rc + adjustment > 1;
 390
 391         return 0;
 392 }
 393
 394 static int sm_metadata_set_count(struct dm_space_map *sm, dm_block_t b,
 395                                  uint32_t count)
 396 {
 397         int r, r2;
 398         enum allocation_event ev;
 399         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 400
 401         if (smm->recursion_count) {
 402                 DMERR("cannot recurse set_count()");
 403                 return -EINVAL;
 404         }
 405
 406         in(smm);
 407         r = sm_ll_insert(&smm->ll, b, count, &ev);
 408         r2 = out(smm);
 409
 410         return combine_errors(r, r2);
 411 }
 412
 413 static int sm_metadata_inc_block(struct dm_space_map *sm, dm_block_t b)
 414 {
 415         int r, r2 = 0;
 416         enum allocation_event ev;
 417         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 418
 419         if (recursing(smm))
 420                 r = add_bop(smm, BOP_INC, b);
 421         else {
 422                 in(smm);
 423                 r = sm_ll_inc(&smm->ll, b, &ev);
 424                 r2 = out(smm);
 425         }
 426
 427         return combine_errors(r, r2);
 428 }
 429
 430 static int sm_metadata_dec_block(struct dm_space_map *sm, dm_block_t b)
 431 {
 432         int r, r2 = 0;
 433         enum allocation_event ev;
 434         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 435
 436         if (recursing(smm))
 437                 r = add_bop(smm, BOP_DEC, b);
 438         else {
 439                 in(smm);
 440                 r = sm_ll_dec(&smm->ll, b, &ev);
 441                 r2 = out(smm);
 442         }
 443
 444         return combine_errors(r, r2);
 445 }
 446
 447 static int sm_metadata_new_block_(struct dm_space_map *sm, dm_block_t *b)
 448 {
 449         int r, r2 = 0;
 450         enum allocation_event ev;
 451         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 452
 453         r = sm_ll_find_free_block(&smm->old_ll, smm->begin, smm->old_ll.nr_blocks, b);
 454         if (r)
 455                 return r;
 456
 457         smm->begin = *b + 1;
 458
 459         if (recursing(smm))
 460                 r = add_bop(smm, BOP_INC, *b);
 461         else {
 462                 in(smm);
 463                 r = sm_ll_inc(&smm->ll, *b, &ev);
 464                 r2 = out(smm);
 465         }
 466
 467         if (!r)
 468                 smm->allocated_this_transaction++;
 469
 470         return combine_errors(r, r2);
 471 }
 472
 473 static int sm_metadata_new_block(struct dm_space_map *sm, dm_block_t *b)
 474 {
 475         dm_block_t count;
 476         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 477
 478         int r = sm_metadata_new_block_(sm, b);
 479         if (r) {
 480                 DMERR_LIMIT("unable to allocate new metadata block");
 481                 return r;
 482         }
 483
 484         r = sm_metadata_get_nr_free(sm, &count);
 485         if (r) {
 486                 DMERR_LIMIT("couldn't get free block count");
 487                 return r;
 488         }
 489
 490         check_threshold(&smm->threshold, count);
 491
 492         return r;
 493 }
 494
 495 static int sm_metadata_commit(struct dm_space_map *sm)
 496 {
 497         int r;
 498         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 499
 500         r = sm_ll_commit(&smm->ll);
 501         if (r)
 502                 return r;
 503
 504         memcpy(&smm->old_ll, &smm->ll, sizeof(smm->old_ll));
 505         smm->begin = 0;
 506         smm->allocated_this_transaction = 0;
 507
 508         return 0;
 509 }
 510
 511 static int sm_metadata_register_threshold_callback(struct dm_space_map *sm,
 512                                                    dm_block_t threshold,
 513                                                    dm_sm_threshold_fn fn,
 514                                                    void *context)
 515 {
 516         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 517
 518         set_threshold(&smm->threshold, threshold, fn, context);
 519
 520         return 0;
 521 }
 522
 523 static int sm_metadata_root_size(struct dm_space_map *sm, size_t *result)
 524 {
 525         *result = sizeof(struct disk_sm_root);
 526
 527         return 0;
 528 }
 529
 530 static int sm_metadata_copy_root(struct dm_space_map *sm, void *where_le, size_t max)
 531 {
 532         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 533         struct disk_sm_root root_le;
 534
 535         root_le.nr_blocks = cpu_to_le64(smm->ll.nr_blocks);
 536         root_le.nr_allocated = cpu_to_le64(smm->ll.nr_allocated);
 537         root_le.bitmap_root = cpu_to_le64(smm->ll.bitmap_root);
 538         root_le.ref_count_root = cpu_to_le64(smm->ll.ref_count_root);
 539
 540         if (max < sizeof(root_le))
 541                 return -ENOSPC;
 542
 543         memcpy(where_le, &root_le, sizeof(root_le));
 544
 545         return 0;
 546 }
 547
 548 static int sm_metadata_extend(struct dm_space_map *sm, dm_block_t extra_blocks);
 549
 550 static struct dm_space_map ops = {
 551         .destroy = sm_metadata_destroy,
 552         .extend = sm_metadata_extend,
 553         .get_nr_blocks = sm_metadata_get_nr_blocks,
 554         .get_nr_free = sm_metadata_get_nr_free,
 555         .get_count = sm_metadata_get_count,
 556         .count_is_more_than_one = sm_metadata_count_is_more_than_one,
 557         .set_count = sm_metadata_set_count,
 558         .inc_block = sm_metadata_inc_block,
 559         .dec_block = sm_metadata_dec_block,
 560         .new_block = sm_metadata_new_block,
 561         .commit = sm_metadata_commit,
 562         .root_size = sm_metadata_root_size,
 563         .copy_root = sm_metadata_copy_root,
 564         .register_threshold_callback = sm_metadata_register_threshold_callback
 565 };
 566
 567 /*----------------------------------------------------------------*/
 568
 569 /*
 570  * When a new space map is created that manages its own space.  We use
 571  * this tiny bootstrap allocator.
 572  */
 573 static void sm_bootstrap_destroy(struct dm_space_map *sm)
 574 {
 575 }
 576
 577 static int sm_bootstrap_extend(struct dm_space_map *sm, dm_block_t extra_blocks)
 578 {
 579         DMERR("bootstrap doesn't support extend");
 580
 581         return -EINVAL;
 582 }
 583
 584 static int sm_bootstrap_get_nr_blocks(struct dm_space_map *sm, dm_block_t *count)
 585 {
 586         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 587
 588         *count = smm->ll.nr_blocks;
 589
 590         return 0;
 591 }
 592
 593 static int sm_bootstrap_get_nr_free(struct dm_space_map *sm, dm_block_t *count)
 594 {
 595         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 596
 597         *count = smm->ll.nr_blocks - smm->begin;
 598
 599         return 0;
 600 }
 601
 602 static int sm_bootstrap_get_count(struct dm_space_map *sm, dm_block_t b,
 603                                   uint32_t *result)
 604 {
 605         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 606
 607         *result = (b < smm->begin) ? 1 : 0;
 608
 609         return 0;
 610 }
 611
 612 static int sm_bootstrap_count_is_more_than_one(struct dm_space_map *sm,
 613                                                dm_block_t b, int *result)
 614 {
 615         *result = 0;
 616
 617         return 0;
 618 }
 619
 620 static int sm_bootstrap_set_count(struct dm_space_map *sm, dm_block_t b,
 621                                   uint32_t count)
 622 {
 623         DMERR("bootstrap doesn't support set_count");
 624
 625         return -EINVAL;
 626 }
 627
 628 static int sm_bootstrap_new_block(struct dm_space_map *sm, dm_block_t *b)
 629 {
 630         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 631
 632         /*
 633          * We know the entire device is unused.
 634          */
 635         if (smm->begin == smm->ll.nr_blocks)
 636                 return -ENOSPC;
 637
 638         *b = smm->begin++;
 639
 640         return 0;
 641 }
 642
 643 static int sm_bootstrap_inc_block(struct dm_space_map *sm, dm_block_t b)
 644 {
 645         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 646
 647         return add_bop(smm, BOP_INC, b);
 648 }
 649
 650 static int sm_bootstrap_dec_block(struct dm_space_map *sm, dm_block_t b)
 651 {
 652         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 653
 654         return add_bop(smm, BOP_DEC, b);
 655 }
 656
 657 static int sm_bootstrap_commit(struct dm_space_map *sm)
 658 {
 659         return 0;
 660 }
 661
 662 static int sm_bootstrap_root_size(struct dm_space_map *sm, size_t *result)
 663 {
 664         DMERR("bootstrap doesn't support root_size");
 665
 666         return -EINVAL;
 667 }
 668
 669 static int sm_bootstrap_copy_root(struct dm_space_map *sm, void *where,
 670                                   size_t max)
 671 {
 672         DMERR("bootstrap doesn't support copy_root");
 673
 674         return -EINVAL;
 675 }
 676
 677 static struct dm_space_map bootstrap_ops = {
 678         .destroy = sm_bootstrap_destroy,
 679         .extend = sm_bootstrap_extend,
 680         .get_nr_blocks = sm_bootstrap_get_nr_blocks,
 681         .get_nr_free = sm_bootstrap_get_nr_free,
 682         .get_count = sm_bootstrap_get_count,
 683         .count_is_more_than_one = sm_bootstrap_count_is_more_than_one,
 684         .set_count = sm_bootstrap_set_count,
 685         .inc_block = sm_bootstrap_inc_block,
 686         .dec_block = sm_bootstrap_dec_block,
 687         .new_block = sm_bootstrap_new_block,
 688         .commit = sm_bootstrap_commit,
 689         .root_size = sm_bootstrap_root_size,
 690         .copy_root = sm_bootstrap_copy_root,
 691         .register_threshold_callback = NULL
 692 };
 693
 694 /*----------------------------------------------------------------*/
 695
 696 static int sm_metadata_extend(struct dm_space_map *sm, dm_block_t extra_blocks)
 697 {
 698         int r, i;
 699         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 700         dm_block_t old_len = smm->ll.nr_blocks;
 701
 702         /*
 703          * Flick into a mode where all blocks get allocated in the new area.
 704          */
 705         smm->begin = old_len;
 706         memcpy(sm, &bootstrap_ops, sizeof(*sm));
 707
 708         /*
 709          * Extend.
 710          */
 711         r = sm_ll_extend(&smm->ll, extra_blocks);
 712         if (r)
 713                 goto out;
 714
 715         /*
 716          * We repeatedly increment then commit until the commit doesn't
 717          * allocate any new blocks.
 718          */
 719         do {
 720                 for (i = old_len; !r && i < smm->begin; i++)
 721                         r = add_bop(smm, BOP_INC, i);
 722
 723                 if (r)
 724                         goto out;
 725
 726                 old_len = smm->begin;
 727
 728                 r = apply_bops(smm);
 729                 if (r) {
 730                         DMERR("%s: apply_bops failed", __func__);
 731                         goto out;
 732                 }
 733
 734                 r = sm_ll_commit(&smm->ll);
 735                 if (r)
 736                         goto out;
 737
 738         } while (old_len != smm->begin);
 739
 740 out:
 741         /*
 742          * Switch back to normal behaviour.
 743          */
 744         memcpy(sm, &ops, sizeof(*sm));
 745         return r;
 746 }
 747
 748 /*----------------------------------------------------------------*/
 749
 750 struct dm_space_map *dm_sm_metadata_init(void)
 751 {
 752         struct sm_metadata *smm;
 753
 754         smm = kmalloc(sizeof(*smm), GFP_KERNEL);
 755         if (!smm)
 756                 return ERR_PTR(-ENOMEM);
 757
 758         memcpy(&smm->sm, &ops, sizeof(smm->sm));
 759
 760         return &smm->sm;
 761 }
 762
 763 int dm_sm_metadata_create(struct dm_space_map *sm,
 764                           struct dm_transaction_manager *tm,
 765                           dm_block_t nr_blocks,
 766                           dm_block_t superblock)
 767 {
 768         int r;
 769         dm_block_t i;
 770         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 771
 772         smm->begin = superblock + 1;
 773         smm->recursion_count = 0;
 774         smm->allocated_this_transaction = 0;
 775         brb_init(&smm->uncommitted);
 776         threshold_init(&smm->threshold);
 777
 778         memcpy(&smm->sm, &bootstrap_ops, sizeof(smm->sm));
 779
 780         r = sm_ll_new_metadata(&smm->ll, tm);
 781         if (r)
 782                 return r;
 783
 784         if (nr_blocks > DM_SM_METADATA_MAX_BLOCKS)
 785                 nr_blocks = DM_SM_METADATA_MAX_BLOCKS;
 786         r = sm_ll_extend(&smm->ll, nr_blocks);
 787         if (r)
 788                 return r;
 789
 790         memcpy(&smm->sm, &ops, sizeof(smm->sm));
 791
 792         /*
 793          * Now we need to update the newly created data structures with the
 794          * allocated blocks that they were built from.
 795          */
 796         for (i = superblock; !r && i < smm->begin; i++)
 797                 r = add_bop(smm, BOP_INC, i);
 798
 799         if (r)
 800                 return r;
 801
 802         r = apply_bops(smm);
 803         if (r) {
 804                 DMERR("%s: apply_bops failed", __func__);
 805                 return r;
 806         }
 807
 808         return sm_metadata_commit(sm);
 809 }
 810
 811 int dm_sm_metadata_open(struct dm_space_map *sm,
 812                         struct dm_transaction_manager *tm,
 813                         void *root_le, size_t len)
 814 {
 815         int r;
 816         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 817
 818         r = sm_ll_open_metadata(&smm->ll, tm, root_le, len);
 819         if (r)
 820                 return r;
 821
 822         smm->begin = 0;
 823         smm->recursion_count = 0;
 824         smm->allocated_this_transaction = 0;
 825         brb_init(&smm->uncommitted);
 826         threshold_init(&smm->threshold);
 827
 828         memcpy(&smm->old_ll, &smm->ll, sizeof(smm->old_ll));
 829         return 0;
 830 }