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

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2011 Red Hat, Inc.
   4  *
   5  * This file is released under the GPL.
   6  */
   7
   8 #include "dm-space-map.h"
   9 #include "dm-space-map-common.h"
  10 #include "dm-space-map-metadata.h"
  11
  12 #include <linux/list.h>
  13 #include <linux/slab.h>
  14 #include <linux/device-mapper.h>
  15 #include <linux/kernel.h>
  16
  17 #define DM_MSG_PREFIX "space map metadata"
  18
  19 /*----------------------------------------------------------------*/
  20
  21 /*
  22  * An edge triggered threshold.
  23  */
  24 struct threshold {
  25         bool threshold_set;
  26         bool value_set;
  27         dm_block_t threshold;
  28         dm_block_t current_value;
  29         dm_sm_threshold_fn fn;
  30         void *context;
  31 };
  32
  33 static void threshold_init(struct threshold *t)
  34 {
  35         t->threshold_set = false;
  36         t->value_set = false;
  37 }
  38
  39 static void set_threshold(struct threshold *t, dm_block_t value,
  40                           dm_sm_threshold_fn fn, void *context)
  41 {
  42         t->threshold_set = true;
  43         t->threshold = value;
  44         t->fn = fn;
  45         t->context = context;
  46 }
  47
  48 static bool below_threshold(struct threshold *t, dm_block_t value)
  49 {
  50         return t->threshold_set && value <= t->threshold;
  51 }
  52
  53 static bool threshold_already_triggered(struct threshold *t)
  54 {
  55         return t->value_set && below_threshold(t, t->current_value);
  56 }
  57
  58 static void check_threshold(struct threshold *t, dm_block_t value)
  59 {
  60         if (below_threshold(t, value) &&
  61             !threshold_already_triggered(t))
  62                 t->fn(t->context);
  63
  64         t->value_set = true;
  65         t->current_value = value;
  66 }
  67
  68 /*----------------------------------------------------------------*/
  69
  70 /*
  71  * Space map interface.
  72  *
  73  * The low level disk format is written using the standard btree and
  74  * transaction manager.  This means that performing disk operations may
  75  * cause us to recurse into the space map in order to allocate new blocks.
  76  * For this reason we have a pool of pre-allocated blocks large enough to
  77  * service any metadata_ll_disk operation.
  78  */
  79
  80 /*
  81  * FIXME: we should calculate this based on the size of the device.
  82  * Only the metadata space map needs this functionality.
  83  */
  84 #define MAX_RECURSIVE_ALLOCATIONS 1024
  85
  86 enum block_op_type {
  87         BOP_INC,
  88         BOP_DEC
  89 };
  90
  91 struct block_op {
  92         enum block_op_type type;
  93         dm_block_t b;
  94         dm_block_t e;
  95 };
  96
  97 struct bop_ring_buffer {
  98         unsigned int begin;
  99         unsigned int end;
 100         struct block_op bops[MAX_RECURSIVE_ALLOCATIONS + 1];
 101 };
 102
 103 static void brb_init(struct bop_ring_buffer *brb)
 104 {
 105         brb->begin = 0;
 106         brb->end = 0;
 107 }
 108
 109 static bool brb_empty(struct bop_ring_buffer *brb)
 110 {
 111         return brb->begin == brb->end;
 112 }
 113
 114 static unsigned int brb_next(struct bop_ring_buffer *brb, unsigned int old)
 115 {
 116         unsigned int r = old + 1;
 117
 118         return r >= ARRAY_SIZE(brb->bops) ? 0 : r;
 119 }
 120
 121 static int brb_push(struct bop_ring_buffer *brb,
 122                     enum block_op_type type, dm_block_t b, dm_block_t e)
 123 {
 124         struct block_op *bop;
 125         unsigned int next = brb_next(brb, brb->end);
 126
 127         /*
 128          * We don't allow the last bop to be filled, this way we can
 129          * differentiate between full and empty.
 130          */
 131         if (next == brb->begin)
 132                 return -ENOMEM;
 133
 134         bop = brb->bops + brb->end;
 135         bop->type = type;
 136         bop->b = b;
 137         bop->e = e;
 138
 139         brb->end = next;
 140
 141         return 0;
 142 }
 143
 144 static int brb_peek(struct bop_ring_buffer *brb, struct block_op *result)
 145 {
 146         struct block_op *bop;
 147
 148         if (brb_empty(brb))
 149                 return -ENODATA;
 150
 151         bop = brb->bops + brb->begin;
 152         memcpy(result, bop, sizeof(*result));
 153         return 0;
 154 }
 155
 156 static int brb_pop(struct bop_ring_buffer *brb)
 157 {
 158         if (brb_empty(brb))
 159                 return -ENODATA;
 160
 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 int recursion_count;
 177         unsigned int 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, dm_block_t e)
 184 {
 185         int r = brb_push(&smm->uncommitted, type, b, e);
 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         int32_t nr_allocations;
 199
 200         switch (op->type) {
 201         case BOP_INC:
 202                 r = sm_ll_inc(&smm->ll, op->b, op->e, &nr_allocations);
 203                 break;
 204
 205         case BOP_DEC:
 206                 r = sm_ll_dec(&smm->ll, op->b, op->e, &nr_allocations);
 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                 r = 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         kvfree(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 int i;
 307         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 308         unsigned int 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 (b < op->b || b >= op->e)
 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 int 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 (b < op->b || b >= op->e)
 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         int32_t nr_allocations;
 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, &nr_allocations);
 408         r2 = out(smm);
 409
 410         return combine_errors(r, r2);
 411 }
 412
 413 static int sm_metadata_inc_blocks(struct dm_space_map *sm, dm_block_t b, dm_block_t e)
 414 {
 415         int r, r2 = 0;
 416         int32_t nr_allocations;
 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, e);
 421                 if (r)
 422                         return r;
 423         } else {
 424                 in(smm);
 425                 r = sm_ll_inc(&smm->ll, b, e, &nr_allocations);
 426                 r2 = out(smm);
 427         }
 428
 429         return combine_errors(r, r2);
 430 }
 431
 432 static int sm_metadata_dec_blocks(struct dm_space_map *sm, dm_block_t b, dm_block_t e)
 433 {
 434         int r, r2 = 0;
 435         int32_t nr_allocations;
 436         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 437
 438         if (recursing(smm))
 439                 r = add_bop(smm, BOP_DEC, b, e);
 440         else {
 441                 in(smm);
 442                 r = sm_ll_dec(&smm->ll, b, e, &nr_allocations);
 443                 r2 = out(smm);
 444         }
 445
 446         return combine_errors(r, r2);
 447 }
 448
 449 static int sm_metadata_new_block_(struct dm_space_map *sm, dm_block_t *b)
 450 {
 451         int r, r2 = 0;
 452         int32_t nr_allocations;
 453         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 454
 455         /*
 456          * Any block we allocate has to be free in both the old and current ll.
 457          */
 458         r = sm_ll_find_common_free_block(&smm->old_ll, &smm->ll, smm->begin, smm->ll.nr_blocks, b);
 459         if (r == -ENOSPC) {
 460                 /*
 461                  * There's no free block between smm->begin and the end of the metadata device.
 462                  * We search before smm->begin in case something has been freed.
 463                  */
 464                 r = sm_ll_find_common_free_block(&smm->old_ll, &smm->ll, 0, smm->begin, b);
 465         }
 466
 467         if (r)
 468                 return r;
 469
 470         smm->begin = *b + 1;
 471
 472         if (recursing(smm))
 473                 r = add_bop(smm, BOP_INC, *b, *b + 1);
 474         else {
 475                 in(smm);
 476                 r = sm_ll_inc(&smm->ll, *b, *b + 1, &nr_allocations);
 477                 r2 = out(smm);
 478         }
 479
 480         if (!r)
 481                 smm->allocated_this_transaction++;
 482
 483         return combine_errors(r, r2);
 484 }
 485
 486 static int sm_metadata_new_block(struct dm_space_map *sm, dm_block_t *b)
 487 {
 488         dm_block_t count;
 489         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 490
 491         int r = sm_metadata_new_block_(sm, b);
 492
 493         if (r) {
 494                 DMERR_LIMIT("unable to allocate new metadata block");
 495                 return r;
 496         }
 497
 498         r = sm_metadata_get_nr_free(sm, &count);
 499         if (r) {
 500                 DMERR_LIMIT("couldn't get free block count");
 501                 return r;
 502         }
 503
 504         check_threshold(&smm->threshold, count);
 505
 506         return r;
 507 }
 508
 509 static int sm_metadata_commit(struct dm_space_map *sm)
 510 {
 511         int r;
 512         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 513
 514         r = sm_ll_commit(&smm->ll);
 515         if (r)
 516                 return r;
 517
 518         memcpy(&smm->old_ll, &smm->ll, sizeof(smm->old_ll));
 519         smm->allocated_this_transaction = 0;
 520
 521         return 0;
 522 }
 523
 524 static int sm_metadata_register_threshold_callback(struct dm_space_map *sm,
 525                                                    dm_block_t threshold,
 526                                                    dm_sm_threshold_fn fn,
 527                                                    void *context)
 528 {
 529         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 530
 531         set_threshold(&smm->threshold, threshold, fn, context);
 532
 533         return 0;
 534 }
 535
 536 static int sm_metadata_root_size(struct dm_space_map *sm, size_t *result)
 537 {
 538         *result = sizeof(struct disk_sm_root);
 539
 540         return 0;
 541 }
 542
 543 static int sm_metadata_copy_root(struct dm_space_map *sm, void *where_le, size_t max)
 544 {
 545         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 546         struct disk_sm_root root_le;
 547
 548         root_le.nr_blocks = cpu_to_le64(smm->ll.nr_blocks);
 549         root_le.nr_allocated = cpu_to_le64(smm->ll.nr_allocated);
 550         root_le.bitmap_root = cpu_to_le64(smm->ll.bitmap_root);
 551         root_le.ref_count_root = cpu_to_le64(smm->ll.ref_count_root);
 552
 553         if (max < sizeof(root_le))
 554                 return -ENOSPC;
 555
 556         memcpy(where_le, &root_le, sizeof(root_le));
 557
 558         return 0;
 559 }
 560
 561 static int sm_metadata_extend(struct dm_space_map *sm, dm_block_t extra_blocks);
 562
 563 static const struct dm_space_map ops = {
 564         .destroy = sm_metadata_destroy,
 565         .extend = sm_metadata_extend,
 566         .get_nr_blocks = sm_metadata_get_nr_blocks,
 567         .get_nr_free = sm_metadata_get_nr_free,
 568         .get_count = sm_metadata_get_count,
 569         .count_is_more_than_one = sm_metadata_count_is_more_than_one,
 570         .set_count = sm_metadata_set_count,
 571         .inc_blocks = sm_metadata_inc_blocks,
 572         .dec_blocks = sm_metadata_dec_blocks,
 573         .new_block = sm_metadata_new_block,
 574         .commit = sm_metadata_commit,
 575         .root_size = sm_metadata_root_size,
 576         .copy_root = sm_metadata_copy_root,
 577         .register_threshold_callback = sm_metadata_register_threshold_callback
 578 };
 579
 580 /*----------------------------------------------------------------*/
 581
 582 /*
 583  * When a new space map is created that manages its own space.  We use
 584  * this tiny bootstrap allocator.
 585  */
 586 static void sm_bootstrap_destroy(struct dm_space_map *sm)
 587 {
 588 }
 589
 590 static int sm_bootstrap_extend(struct dm_space_map *sm, dm_block_t extra_blocks)
 591 {
 592         DMERR("bootstrap doesn't support extend");
 593
 594         return -EINVAL;
 595 }
 596
 597 static int sm_bootstrap_get_nr_blocks(struct dm_space_map *sm, dm_block_t *count)
 598 {
 599         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 600
 601         *count = smm->ll.nr_blocks;
 602
 603         return 0;
 604 }
 605
 606 static int sm_bootstrap_get_nr_free(struct dm_space_map *sm, dm_block_t *count)
 607 {
 608         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 609
 610         *count = smm->ll.nr_blocks - smm->begin;
 611
 612         return 0;
 613 }
 614
 615 static int sm_bootstrap_get_count(struct dm_space_map *sm, dm_block_t b,
 616                                   uint32_t *result)
 617 {
 618         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 619
 620         *result = (b < smm->begin) ? 1 : 0;
 621
 622         return 0;
 623 }
 624
 625 static int sm_bootstrap_count_is_more_than_one(struct dm_space_map *sm,
 626                                                dm_block_t b, int *result)
 627 {
 628         *result = 0;
 629
 630         return 0;
 631 }
 632
 633 static int sm_bootstrap_set_count(struct dm_space_map *sm, dm_block_t b,
 634                                   uint32_t count)
 635 {
 636         DMERR("bootstrap doesn't support set_count");
 637
 638         return -EINVAL;
 639 }
 640
 641 static int sm_bootstrap_new_block(struct dm_space_map *sm, dm_block_t *b)
 642 {
 643         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 644
 645         /*
 646          * We know the entire device is unused.
 647          */
 648         if (smm->begin == smm->ll.nr_blocks)
 649                 return -ENOSPC;
 650
 651         *b = smm->begin++;
 652
 653         return 0;
 654 }
 655
 656 static int sm_bootstrap_inc_blocks(struct dm_space_map *sm, dm_block_t b, dm_block_t e)
 657 {
 658         int r;
 659         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 660
 661         r = add_bop(smm, BOP_INC, b, e);
 662         if (r)
 663                 return r;
 664
 665         return 0;
 666 }
 667
 668 static int sm_bootstrap_dec_blocks(struct dm_space_map *sm, dm_block_t b, dm_block_t e)
 669 {
 670         int r;
 671         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 672
 673         r = add_bop(smm, BOP_DEC, b, e);
 674         if (r)
 675                 return r;
 676
 677         return 0;
 678 }
 679
 680 static int sm_bootstrap_commit(struct dm_space_map *sm)
 681 {
 682         return 0;
 683 }
 684
 685 static int sm_bootstrap_root_size(struct dm_space_map *sm, size_t *result)
 686 {
 687         DMERR("bootstrap doesn't support root_size");
 688
 689         return -EINVAL;
 690 }
 691
 692 static int sm_bootstrap_copy_root(struct dm_space_map *sm, void *where,
 693                                   size_t max)
 694 {
 695         DMERR("bootstrap doesn't support copy_root");
 696
 697         return -EINVAL;
 698 }
 699
 700 static const struct dm_space_map bootstrap_ops = {
 701         .destroy = sm_bootstrap_destroy,
 702         .extend = sm_bootstrap_extend,
 703         .get_nr_blocks = sm_bootstrap_get_nr_blocks,
 704         .get_nr_free = sm_bootstrap_get_nr_free,
 705         .get_count = sm_bootstrap_get_count,
 706         .count_is_more_than_one = sm_bootstrap_count_is_more_than_one,
 707         .set_count = sm_bootstrap_set_count,
 708         .inc_blocks = sm_bootstrap_inc_blocks,
 709         .dec_blocks = sm_bootstrap_dec_blocks,
 710         .new_block = sm_bootstrap_new_block,
 711         .commit = sm_bootstrap_commit,
 712         .root_size = sm_bootstrap_root_size,
 713         .copy_root = sm_bootstrap_copy_root,
 714         .register_threshold_callback = NULL
 715 };
 716
 717 /*----------------------------------------------------------------*/
 718
 719 static int sm_metadata_extend(struct dm_space_map *sm, dm_block_t extra_blocks)
 720 {
 721         int r;
 722         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 723         dm_block_t old_len = smm->ll.nr_blocks;
 724
 725         /*
 726          * Flick into a mode where all blocks get allocated in the new area.
 727          */
 728         smm->begin = old_len;
 729         memcpy(sm, &bootstrap_ops, sizeof(*sm));
 730
 731         /*
 732          * Extend.
 733          */
 734         r = sm_ll_extend(&smm->ll, extra_blocks);
 735         if (r)
 736                 goto out;
 737
 738         /*
 739          * We repeatedly increment then commit until the commit doesn't
 740          * allocate any new blocks.
 741          */
 742         do {
 743                 r = add_bop(smm, BOP_INC, old_len, smm->begin);
 744                 if (r)
 745                         goto out;
 746
 747                 old_len = smm->begin;
 748
 749                 r = apply_bops(smm);
 750                 if (r) {
 751                         DMERR("%s: apply_bops failed", __func__);
 752                         goto out;
 753                 }
 754
 755                 r = sm_ll_commit(&smm->ll);
 756                 if (r)
 757                         goto out;
 758
 759         } while (old_len != smm->begin);
 760
 761 out:
 762         /*
 763          * Switch back to normal behaviour.
 764          */
 765         memcpy(sm, &ops, sizeof(*sm));
 766         return r;
 767 }
 768
 769 /*----------------------------------------------------------------*/
 770
 771 struct dm_space_map *dm_sm_metadata_init(void)
 772 {
 773         struct sm_metadata *smm;
 774
 775         smm = kvmalloc(sizeof(*smm), GFP_KERNEL);
 776         if (!smm)
 777                 return ERR_PTR(-ENOMEM);
 778
 779         memcpy(&smm->sm, &ops, sizeof(smm->sm));
 780
 781         return &smm->sm;
 782 }
 783
 784 int dm_sm_metadata_create(struct dm_space_map *sm,
 785                           struct dm_transaction_manager *tm,
 786                           dm_block_t nr_blocks,
 787                           dm_block_t superblock)
 788 {
 789         int r;
 790         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 791
 792         smm->begin = superblock + 1;
 793         smm->recursion_count = 0;
 794         smm->allocated_this_transaction = 0;
 795         brb_init(&smm->uncommitted);
 796         threshold_init(&smm->threshold);
 797
 798         memcpy(&smm->sm, &bootstrap_ops, sizeof(smm->sm));
 799
 800         r = sm_ll_new_metadata(&smm->ll, tm);
 801         if (!r) {
 802                 if (nr_blocks > DM_SM_METADATA_MAX_BLOCKS)
 803                         nr_blocks = DM_SM_METADATA_MAX_BLOCKS;
 804                 r = sm_ll_extend(&smm->ll, nr_blocks);
 805         }
 806         memcpy(&smm->sm, &ops, sizeof(smm->sm));
 807         if (r)
 808                 return r;
 809
 810         /*
 811          * Now we need to update the newly created data structures with the
 812          * allocated blocks that they were built from.
 813          */
 814         r = add_bop(smm, BOP_INC, superblock, smm->begin);
 815         if (r)
 816                 return r;
 817
 818         r = apply_bops(smm);
 819         if (r) {
 820                 DMERR("%s: apply_bops failed", __func__);
 821                 return r;
 822         }
 823
 824         return sm_metadata_commit(sm);
 825 }
 826
 827 int dm_sm_metadata_open(struct dm_space_map *sm,
 828                         struct dm_transaction_manager *tm,
 829                         void *root_le, size_t len)
 830 {
 831         int r;
 832         struct sm_metadata *smm = container_of(sm, struct sm_metadata, sm);
 833
 834         r = sm_ll_open_metadata(&smm->ll, tm, root_le, len);
 835         if (r)
 836                 return r;
 837
 838         smm->begin = 0;
 839         smm->recursion_count = 0;
 840         smm->allocated_this_transaction = 0;
 841         brb_init(&smm->uncommitted);
 842         threshold_init(&smm->threshold);
 843
 844         memcpy(&smm->old_ll, &smm->ll, sizeof(smm->old_ll));
 845         return 0;
 846 }