drivers/md/dm-table.c

   1 /*
   2  * Copyright (C) 2001 Sistina Software (UK) Limited.
   3  * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
   4  *
   5  * This file is released under the GPL.
   6  */
   7
   8 #include "dm-core.h"
   9
  10 #include <linux/module.h>
  11 #include <linux/vmalloc.h>
  12 #include <linux/blkdev.h>
  13 #include <linux/namei.h>
  14 #include <linux/ctype.h>
  15 #include <linux/string.h>
  16 #include <linux/slab.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/mutex.h>
  19 #include <linux/delay.h>
  20 #include <linux/atomic.h>
  21 #include <linux/blk-mq.h>
  22 #include <linux/mount.h>
  23 #include <linux/dax.h>
  24
  25 #define DM_MSG_PREFIX "table"
  26
  27 #define NODE_SIZE L1_CACHE_BYTES
  28 #define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t))
  29 #define CHILDREN_PER_NODE (KEYS_PER_NODE + 1)
  30
  31 /*
  32  * Similar to ceiling(log_size(n))
  33  */
  34 static unsigned int int_log(unsigned int n, unsigned int base)
  35 {
  36         int result = 0;
  37
  38         while (n > 1) {
  39                 n = dm_div_up(n, base);
  40                 result++;
  41         }
  42
  43         return result;
  44 }
  45
  46 /*
  47  * Calculate the index of the child node of the n'th node k'th key.
  48  */
  49 static inline unsigned int get_child(unsigned int n, unsigned int k)
  50 {
  51         return (n * CHILDREN_PER_NODE) + k;
  52 }
  53
  54 /*
  55  * Return the n'th node of level l from table t.
  56  */
  57 static inline sector_t *get_node(struct dm_table *t,
  58                                  unsigned int l, unsigned int n)
  59 {
  60         return t->index[l] + (n * KEYS_PER_NODE);
  61 }
  62
  63 /*
  64  * Return the highest key that you could lookup from the n'th
  65  * node on level l of the btree.
  66  */
  67 static sector_t high(struct dm_table *t, unsigned int l, unsigned int n)
  68 {
  69         for (; l < t->depth - 1; l++)
  70                 n = get_child(n, CHILDREN_PER_NODE - 1);
  71
  72         if (n >= t->counts[l])
  73                 return (sector_t) - 1;
  74
  75         return get_node(t, l, n)[KEYS_PER_NODE - 1];
  76 }
  77
  78 /*
  79  * Fills in a level of the btree based on the highs of the level
  80  * below it.
  81  */
  82 static int setup_btree_index(unsigned int l, struct dm_table *t)
  83 {
  84         unsigned int n, k;
  85         sector_t *node;
  86
  87         for (n = 0U; n < t->counts[l]; n++) {
  88                 node = get_node(t, l, n);
  89
  90                 for (k = 0U; k < KEYS_PER_NODE; k++)
  91                         node[k] = high(t, l + 1, get_child(n, k));
  92         }
  93
  94         return 0;
  95 }
  96
  97 void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size)
  98 {
  99         unsigned long size;
 100         void *addr;
 101
 102         /*
 103          * Check that we're not going to overflow.
 104          */
 105         if (nmemb > (ULONG_MAX / elem_size))
 106                 return NULL;
 107
 108         size = nmemb * elem_size;
 109         addr = vzalloc(size);
 110
 111         return addr;
 112 }
 113 EXPORT_SYMBOL(dm_vcalloc);
 114
 115 /*
 116  * highs, and targets are managed as dynamic arrays during a
 117  * table load.
 118  */
 119 static int alloc_targets(struct dm_table *t, unsigned int num)
 120 {
 121         sector_t *n_highs;
 122         struct dm_target *n_targets;
 123
 124         /*
 125          * Allocate both the target array and offset array at once.
 126          */
 127         n_highs = (sector_t *) dm_vcalloc(num, sizeof(struct dm_target) +
 128                                           sizeof(sector_t));
 129         if (!n_highs)
 130                 return -ENOMEM;
 131
 132         n_targets = (struct dm_target *) (n_highs + num);
 133
 134         memset(n_highs, -1, sizeof(*n_highs) * num);
 135         vfree(t->highs);
 136
 137         t->num_allocated = num;
 138         t->highs = n_highs;
 139         t->targets = n_targets;
 140
 141         return 0;
 142 }
 143
 144 int dm_table_create(struct dm_table **result, fmode_t mode,
 145                     unsigned num_targets, struct mapped_device *md)
 146 {
 147         struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
 148
 149         if (!t)
 150                 return -ENOMEM;
 151
 152         INIT_LIST_HEAD(&t->devices);
 153
 154         if (!num_targets)
 155                 num_targets = KEYS_PER_NODE;
 156
 157         num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
 158
 159         if (!num_targets) {
 160                 kfree(t);
 161                 return -ENOMEM;
 162         }
 163
 164         if (alloc_targets(t, num_targets)) {
 165                 kfree(t);
 166                 return -ENOMEM;
 167         }
 168
 169         t->type = DM_TYPE_NONE;
 170         t->mode = mode;
 171         t->md = md;
 172         *result = t;
 173         return 0;
 174 }
 175
 176 static void free_devices(struct list_head *devices, struct mapped_device *md)
 177 {
 178         struct list_head *tmp, *next;
 179
 180         list_for_each_safe(tmp, next, devices) {
 181                 struct dm_dev_internal *dd =
 182                     list_entry(tmp, struct dm_dev_internal, list);
 183                 DMWARN("%s: dm_table_destroy: dm_put_device call missing for %s",
 184                        dm_device_name(md), dd->dm_dev->name);
 185                 dm_put_table_device(md, dd->dm_dev);
 186                 kfree(dd);
 187         }
 188 }
 189
 190 static void dm_table_destroy_keyslot_manager(struct dm_table *t);
 191
 192 void dm_table_destroy(struct dm_table *t)
 193 {
 194         unsigned int i;
 195
 196         if (!t)
 197                 return;
 198
 199         /* free the indexes */
 200         if (t->depth >= 2)
 201                 vfree(t->index[t->depth - 2]);
 202
 203         /* free the targets */
 204         for (i = 0; i < t->num_targets; i++) {
 205                 struct dm_target *tgt = t->targets + i;
 206
 207                 if (tgt->type->dtr)
 208                         tgt->type->dtr(tgt);
 209
 210                 dm_put_target_type(tgt->type);
 211         }
 212
 213         vfree(t->highs);
 214
 215         /* free the device list */
 216         free_devices(&t->devices, t->md);
 217
 218         dm_free_md_mempools(t->mempools);
 219
 220         dm_table_destroy_keyslot_manager(t);
 221
 222         kfree(t);
 223 }
 224
 225 /*
 226  * See if we've already got a device in the list.
 227  */
 228 static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
 229 {
 230         struct dm_dev_internal *dd;
 231
 232         list_for_each_entry (dd, l, list)
 233                 if (dd->dm_dev->bdev->bd_dev == dev)
 234                         return dd;
 235
 236         return NULL;
 237 }
 238
 239 /*
 240  * If possible, this checks an area of a destination device is invalid.
 241  */
 242 static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
 243                                   sector_t start, sector_t len, void *data)
 244 {
 245         struct queue_limits *limits = data;
 246         struct block_device *bdev = dev->bdev;
 247         sector_t dev_size =
 248                 i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
 249         unsigned short logical_block_size_sectors =
 250                 limits->logical_block_size >> SECTOR_SHIFT;
 251         char b[BDEVNAME_SIZE];
 252
 253         if (!dev_size)
 254                 return 0;
 255
 256         if ((start >= dev_size) || (start + len > dev_size)) {
 257                 DMWARN("%s: %s too small for target: "
 258                        "start=%llu, len=%llu, dev_size=%llu",
 259                        dm_device_name(ti->table->md), bdevname(bdev, b),
 260                        (unsigned long long)start,
 261                        (unsigned long long)len,
 262                        (unsigned long long)dev_size);
 263                 return 1;
 264         }
 265
 266         /*
 267          * If the target is mapped to zoned block device(s), check
 268          * that the zones are not partially mapped.
 269          */
 270         if (bdev_zoned_model(bdev) != BLK_ZONED_NONE) {
 271                 unsigned int zone_sectors = bdev_zone_sectors(bdev);
 272
 273                 if (start & (zone_sectors - 1)) {
 274                         DMWARN("%s: start=%llu not aligned to h/w zone size %u of %s",
 275                                dm_device_name(ti->table->md),
 276                                (unsigned long long)start,
 277                                zone_sectors, bdevname(bdev, b));
 278                         return 1;
 279                 }
 280
 281                 /*
 282                  * Note: The last zone of a zoned block device may be smaller
 283                  * than other zones. So for a target mapping the end of a
 284                  * zoned block device with such a zone, len would not be zone
 285                  * aligned. We do not allow such last smaller zone to be part
 286                  * of the mapping here to ensure that mappings with multiple
 287                  * devices do not end up with a smaller zone in the middle of
 288                  * the sector range.
 289                  */
 290                 if (len & (zone_sectors - 1)) {
 291                         DMWARN("%s: len=%llu not aligned to h/w zone size %u of %s",
 292                                dm_device_name(ti->table->md),
 293                                (unsigned long long)len,
 294                                zone_sectors, bdevname(bdev, b));
 295                         return 1;
 296                 }
 297         }
 298
 299         if (logical_block_size_sectors <= 1)
 300                 return 0;
 301
 302         if (start & (logical_block_size_sectors - 1)) {
 303                 DMWARN("%s: start=%llu not aligned to h/w "
 304                        "logical block size %u of %s",
 305                        dm_device_name(ti->table->md),
 306                        (unsigned long long)start,
 307                        limits->logical_block_size, bdevname(bdev, b));
 308                 return 1;
 309         }
 310
 311         if (len & (logical_block_size_sectors - 1)) {
 312                 DMWARN("%s: len=%llu not aligned to h/w "
 313                        "logical block size %u of %s",
 314                        dm_device_name(ti->table->md),
 315                        (unsigned long long)len,
 316                        limits->logical_block_size, bdevname(bdev, b));
 317                 return 1;
 318         }
 319
 320         return 0;
 321 }
 322
 323 /*
 324  * This upgrades the mode on an already open dm_dev, being
 325  * careful to leave things as they were if we fail to reopen the
 326  * device and not to touch the existing bdev field in case
 327  * it is accessed concurrently.
 328  */
 329 static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
 330                         struct mapped_device *md)
 331 {
 332         int r;
 333         struct dm_dev *old_dev, *new_dev;
 334
 335         old_dev = dd->dm_dev;
 336
 337         r = dm_get_table_device(md, dd->dm_dev->bdev->bd_dev,
 338                                 dd->dm_dev->mode | new_mode, &new_dev);
 339         if (r)
 340                 return r;
 341
 342         dd->dm_dev = new_dev;
 343         dm_put_table_device(md, old_dev);
 344
 345         return 0;
 346 }
 347
 348 /*
 349  * Convert the path to a device
 350  */
 351 dev_t dm_get_dev_t(const char *path)
 352 {
 353         dev_t dev;
 354
 355         if (lookup_bdev(path, &dev))
 356                 dev = name_to_dev_t(path);
 357         return dev;
 358 }
 359 EXPORT_SYMBOL_GPL(dm_get_dev_t);
 360
 361 /*
 362  * Add a device to the list, or just increment the usage count if
 363  * it's already present.
 364  */
 365 int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
 366                   struct dm_dev **result)
 367 {
 368         int r;
 369         dev_t dev;
 370         unsigned int major, minor;
 371         char dummy;
 372         struct dm_dev_internal *dd;
 373         struct dm_table *t = ti->table;
 374
 375         BUG_ON(!t);
 376
 377         if (sscanf(path, "%u:%u%c", &major, &minor, &dummy) == 2) {
 378                 /* Extract the major/minor numbers */
 379                 dev = MKDEV(major, minor);
 380                 if (MAJOR(dev) != major || MINOR(dev) != minor)
 381                         return -EOVERFLOW;
 382         } else {
 383                 dev = dm_get_dev_t(path);
 384                 if (!dev)
 385                         return -ENODEV;
 386         }
 387
 388         dd = find_device(&t->devices, dev);
 389         if (!dd) {
 390                 dd = kmalloc(sizeof(*dd), GFP_KERNEL);
 391                 if (!dd)
 392                         return -ENOMEM;
 393
 394                 if ((r = dm_get_table_device(t->md, dev, mode, &dd->dm_dev))) {
 395                         kfree(dd);
 396                         return r;
 397                 }
 398
 399                 refcount_set(&dd->count, 1);
 400                 list_add(&dd->list, &t->devices);
 401                 goto out;
 402
 403         } else if (dd->dm_dev->mode != (mode | dd->dm_dev->mode)) {
 404                 r = upgrade_mode(dd, mode, t->md);
 405                 if (r)
 406                         return r;
 407         }
 408         refcount_inc(&dd->count);
 409 out:
 410         *result = dd->dm_dev;
 411         return 0;
 412 }
 413 EXPORT_SYMBOL(dm_get_device);
 414
 415 static int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
 416                                 sector_t start, sector_t len, void *data)
 417 {
 418         struct queue_limits *limits = data;
 419         struct block_device *bdev = dev->bdev;
 420         struct request_queue *q = bdev_get_queue(bdev);
 421         char b[BDEVNAME_SIZE];
 422
 423         if (unlikely(!q)) {
 424                 DMWARN("%s: Cannot set limits for nonexistent device %s",
 425                        dm_device_name(ti->table->md), bdevname(bdev, b));
 426                 return 0;
 427         }
 428
 429         if (blk_stack_limits(limits, &q->limits,
 430                         get_start_sect(bdev) + start) < 0)
 431                 DMWARN("%s: adding target device %s caused an alignment inconsistency: "
 432                        "physical_block_size=%u, logical_block_size=%u, "
 433                        "alignment_offset=%u, start=%llu",
 434                        dm_device_name(ti->table->md), bdevname(bdev, b),
 435                        q->limits.physical_block_size,
 436                        q->limits.logical_block_size,
 437                        q->limits.alignment_offset,
 438                        (unsigned long long) start << SECTOR_SHIFT);
 439         return 0;
 440 }
 441
 442 /*
 443  * Decrement a device's use count and remove it if necessary.
 444  */
 445 void dm_put_device(struct dm_target *ti, struct dm_dev *d)
 446 {
 447         int found = 0;
 448         struct list_head *devices = &ti->table->devices;
 449         struct dm_dev_internal *dd;
 450
 451         list_for_each_entry(dd, devices, list) {
 452                 if (dd->dm_dev == d) {
 453                         found = 1;
 454                         break;
 455                 }
 456         }
 457         if (!found) {
 458                 DMWARN("%s: device %s not in table devices list",
 459                        dm_device_name(ti->table->md), d->name);
 460                 return;
 461         }
 462         if (refcount_dec_and_test(&dd->count)) {
 463                 dm_put_table_device(ti->table->md, d);
 464                 list_del(&dd->list);
 465                 kfree(dd);
 466         }
 467 }
 468 EXPORT_SYMBOL(dm_put_device);
 469
 470 /*
 471  * Checks to see if the target joins onto the end of the table.
 472  */
 473 static int adjoin(struct dm_table *table, struct dm_target *ti)
 474 {
 475         struct dm_target *prev;
 476
 477         if (!table->num_targets)
 478                 return !ti->begin;
 479
 480         prev = &table->targets[table->num_targets - 1];
 481         return (ti->begin == (prev->begin + prev->len));
 482 }
 483
 484 /*
 485  * Used to dynamically allocate the arg array.
 486  *
 487  * We do first allocation with GFP_NOIO because dm-mpath and dm-thin must
 488  * process messages even if some device is suspended. These messages have a
 489  * small fixed number of arguments.
 490  *
 491  * On the other hand, dm-switch needs to process bulk data using messages and
 492  * excessive use of GFP_NOIO could cause trouble.
 493  */
 494 static char **realloc_argv(unsigned *size, char **old_argv)
 495 {
 496         char **argv;
 497         unsigned new_size;
 498         gfp_t gfp;
 499
 500         if (*size) {
 501                 new_size = *size * 2;
 502                 gfp = GFP_KERNEL;
 503         } else {
 504                 new_size = 8;
 505                 gfp = GFP_NOIO;
 506         }
 507         argv = kmalloc_array(new_size, sizeof(*argv), gfp);
 508         if (argv && old_argv) {
 509                 memcpy(argv, old_argv, *size * sizeof(*argv));
 510                 *size = new_size;
 511         }
 512
 513         kfree(old_argv);
 514         return argv;
 515 }
 516
 517 /*
 518  * Destructively splits up the argument list to pass to ctr.
 519  */
 520 int dm_split_args(int *argc, char ***argvp, char *input)
 521 {
 522         char *start, *end = input, *out, **argv = NULL;
 523         unsigned array_size = 0;
 524
 525         *argc = 0;
 526
 527         if (!input) {
 528                 *argvp = NULL;
 529                 return 0;
 530         }
 531
 532         argv = realloc_argv(&array_size, argv);
 533         if (!argv)
 534                 return -ENOMEM;
 535
 536         while (1) {
 537                 /* Skip whitespace */
 538                 start = skip_spaces(end);
 539
 540                 if (!*start)
 541                         break;  /* success, we hit the end */
 542
 543                 /* 'out' is used to remove any back-quotes */
 544                 end = out = start;
 545                 while (*end) {
 546                         /* Everything apart from '\0' can be quoted */
 547                         if (*end == '\\' && *(end + 1)) {
 548                                 *out++ = *(end + 1);
 549                                 end += 2;
 550                                 continue;
 551                         }
 552
 553                         if (isspace(*end))
 554                                 break;  /* end of token */
 555
 556                         *out++ = *end++;
 557                 }
 558
 559                 /* have we already filled the array ? */
 560                 if ((*argc + 1) > array_size) {
 561                         argv = realloc_argv(&array_size, argv);
 562                         if (!argv)
 563                                 return -ENOMEM;
 564                 }
 565
 566                 /* we know this is whitespace */
 567                 if (*end)
 568                         end++;
 569
 570                 /* terminate the string and put it in the array */
 571                 *out = '\0';
 572                 argv[*argc] = start;
 573                 (*argc)++;
 574         }
 575
 576         *argvp = argv;
 577         return 0;
 578 }
 579
 580 /*
 581  * Impose necessary and sufficient conditions on a devices's table such
 582  * that any incoming bio which respects its logical_block_size can be
 583  * processed successfully.  If it falls across the boundary between
 584  * two or more targets, the size of each piece it gets split into must
 585  * be compatible with the logical_block_size of the target processing it.
 586  */
 587 static int validate_hardware_logical_block_alignment(struct dm_table *table,
 588                                                  struct queue_limits *limits)
 589 {
 590         /*
 591          * This function uses arithmetic modulo the logical_block_size
 592          * (in units of 512-byte sectors).
 593          */
 594         unsigned short device_logical_block_size_sects =
 595                 limits->logical_block_size >> SECTOR_SHIFT;
 596
 597         /*
 598          * Offset of the start of the next table entry, mod logical_block_size.
 599          */
 600         unsigned short next_target_start = 0;
 601
 602         /*
 603          * Given an aligned bio that extends beyond the end of a
 604          * target, how many sectors must the next target handle?
 605          */
 606         unsigned short remaining = 0;
 607
 608         struct dm_target *ti;
 609         struct queue_limits ti_limits;
 610         unsigned i;
 611
 612         /*
 613          * Check each entry in the table in turn.
 614          */
 615         for (i = 0; i < dm_table_get_num_targets(table); i++) {
 616                 ti = dm_table_get_target(table, i);
 617
 618                 blk_set_stacking_limits(&ti_limits);
 619
 620                 /* combine all target devices' limits */
 621                 if (ti->type->iterate_devices)
 622                         ti->type->iterate_devices(ti, dm_set_device_limits,
 623                                                   &ti_limits);
 624
 625                 /*
 626                  * If the remaining sectors fall entirely within this
 627                  * table entry are they compatible with its logical_block_size?
 628                  */
 629                 if (remaining < ti->len &&
 630                     remaining & ((ti_limits.logical_block_size >>
 631                                   SECTOR_SHIFT) - 1))
 632                         break;  /* Error */
 633
 634                 next_target_start =
 635                     (unsigned short) ((next_target_start + ti->len) &
 636                                       (device_logical_block_size_sects - 1));
 637                 remaining = next_target_start ?
 638                     device_logical_block_size_sects - next_target_start : 0;
 639         }
 640
 641         if (remaining) {
 642                 DMWARN("%s: table line %u (start sect %llu len %llu) "
 643                        "not aligned to h/w logical block size %u",
 644                        dm_device_name(table->md), i,
 645                        (unsigned long long) ti->begin,
 646                        (unsigned long long) ti->len,
 647                        limits->logical_block_size);
 648                 return -EINVAL;
 649         }
 650
 651         return 0;
 652 }
 653
 654 int dm_table_add_target(struct dm_table *t, const char *type,
 655                         sector_t start, sector_t len, char *params)
 656 {
 657         int r = -EINVAL, argc;
 658         char **argv;
 659         struct dm_target *tgt;
 660
 661         if (t->singleton) {
 662                 DMERR("%s: target type %s must appear alone in table",
 663                       dm_device_name(t->md), t->targets->type->name);
 664                 return -EINVAL;
 665         }
 666
 667         BUG_ON(t->num_targets >= t->num_allocated);
 668
 669         tgt = t->targets + t->num_targets;
 670         memset(tgt, 0, sizeof(*tgt));
 671
 672         if (!len) {
 673                 DMERR("%s: zero-length target", dm_device_name(t->md));
 674                 return -EINVAL;
 675         }
 676
 677         tgt->type = dm_get_target_type(type);
 678         if (!tgt->type) {
 679                 DMERR("%s: %s: unknown target type", dm_device_name(t->md), type);
 680                 return -EINVAL;
 681         }
 682
 683         if (dm_target_needs_singleton(tgt->type)) {
 684                 if (t->num_targets) {
 685                         tgt->error = "singleton target type must appear alone in table";
 686                         goto bad;
 687                 }
 688                 t->singleton = true;
 689         }
 690
 691         if (dm_target_always_writeable(tgt->type) && !(t->mode & FMODE_WRITE)) {
 692                 tgt->error = "target type may not be included in a read-only table";
 693                 goto bad;
 694         }
 695
 696         if (t->immutable_target_type) {
 697                 if (t->immutable_target_type != tgt->type) {
 698                         tgt->error = "immutable target type cannot be mixed with other target types";
 699                         goto bad;
 700                 }
 701         } else if (dm_target_is_immutable(tgt->type)) {
 702                 if (t->num_targets) {
 703                         tgt->error = "immutable target type cannot be mixed with other target types";
 704                         goto bad;
 705                 }
 706                 t->immutable_target_type = tgt->type;
 707         }
 708
 709         if (dm_target_has_integrity(tgt->type))
 710                 t->integrity_added = 1;
 711
 712         tgt->table = t;
 713         tgt->begin = start;
 714         tgt->len = len;
 715         tgt->error = "Unknown error";
 716
 717         /*
 718          * Does this target adjoin the previous one ?
 719          */
 720         if (!adjoin(t, tgt)) {
 721                 tgt->error = "Gap in table";
 722                 goto bad;
 723         }
 724
 725         r = dm_split_args(&argc, &argv, params);
 726         if (r) {
 727                 tgt->error = "couldn't split parameters (insufficient memory)";
 728                 goto bad;
 729         }
 730
 731         r = tgt->type->ctr(tgt, argc, argv);
 732         kfree(argv);
 733         if (r)
 734                 goto bad;
 735
 736         t->highs[t->num_targets++] = tgt->begin + tgt->len - 1;
 737
 738         if (!tgt->num_discard_bios && tgt->discards_supported)
 739                 DMWARN("%s: %s: ignoring discards_supported because num_discard_bios is zero.",
 740                        dm_device_name(t->md), type);
 741
 742         return 0;
 743
 744  bad:
 745         DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error);
 746         dm_put_target_type(tgt->type);
 747         return r;
 748 }
 749
 750 /*
 751  * Target argument parsing helpers.
 752  */
 753 static int validate_next_arg(const struct dm_arg *arg,
 754                              struct dm_arg_set *arg_set,
 755                              unsigned *value, char **error, unsigned grouped)
 756 {
 757         const char *arg_str = dm_shift_arg(arg_set);
 758         char dummy;
 759
 760         if (!arg_str ||
 761             (sscanf(arg_str, "%u%c", value, &dummy) != 1) ||
 762             (*value < arg->min) ||
 763             (*value > arg->max) ||
 764             (grouped && arg_set->argc < *value)) {
 765                 *error = arg->error;
 766                 return -EINVAL;
 767         }
 768
 769         return 0;
 770 }
 771
 772 int dm_read_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
 773                 unsigned *value, char **error)
 774 {
 775         return validate_next_arg(arg, arg_set, value, error, 0);
 776 }
 777 EXPORT_SYMBOL(dm_read_arg);
 778
 779 int dm_read_arg_group(const struct dm_arg *arg, struct dm_arg_set *arg_set,
 780                       unsigned *value, char **error)
 781 {
 782         return validate_next_arg(arg, arg_set, value, error, 1);
 783 }
 784 EXPORT_SYMBOL(dm_read_arg_group);
 785
 786 const char *dm_shift_arg(struct dm_arg_set *as)
 787 {
 788         char *r;
 789
 790         if (as->argc) {
 791                 as->argc--;
 792                 r = *as->argv;
 793                 as->argv++;
 794                 return r;
 795         }
 796
 797         return NULL;
 798 }
 799 EXPORT_SYMBOL(dm_shift_arg);
 800
 801 void dm_consume_args(struct dm_arg_set *as, unsigned num_args)
 802 {
 803         BUG_ON(as->argc < num_args);
 804         as->argc -= num_args;
 805         as->argv += num_args;
 806 }
 807 EXPORT_SYMBOL(dm_consume_args);
 808
 809 static bool __table_type_bio_based(enum dm_queue_mode table_type)
 810 {
 811         return (table_type == DM_TYPE_BIO_BASED ||
 812                 table_type == DM_TYPE_DAX_BIO_BASED);
 813 }
 814
 815 static bool __table_type_request_based(enum dm_queue_mode table_type)
 816 {
 817         return table_type == DM_TYPE_REQUEST_BASED;
 818 }
 819
 820 void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type)
 821 {
 822         t->type = type;
 823 }
 824 EXPORT_SYMBOL_GPL(dm_table_set_type);
 825
 826 /* validate the dax capability of the target device span */
 827 int device_not_dax_capable(struct dm_target *ti, struct dm_dev *dev,
 828                         sector_t start, sector_t len, void *data)
 829 {
 830         int blocksize = *(int *) data, id;
 831         bool rc;
 832
 833         id = dax_read_lock();
 834         rc = !dax_supported(dev->dax_dev, dev->bdev, blocksize, start, len);
 835         dax_read_unlock(id);
 836
 837         return rc;
 838 }
 839
 840 /* Check devices support synchronous DAX */
 841 static int device_not_dax_synchronous_capable(struct dm_target *ti, struct dm_dev *dev,
 842                                               sector_t start, sector_t len, void *data)
 843 {
 844         return !dev->dax_dev || !dax_synchronous(dev->dax_dev);
 845 }
 846
 847 bool dm_table_supports_dax(struct dm_table *t,
 848                            iterate_devices_callout_fn iterate_fn, int *blocksize)
 849 {
 850         struct dm_target *ti;
 851         unsigned i;
 852
 853         /* Ensure that all targets support DAX. */
 854         for (i = 0; i < dm_table_get_num_targets(t); i++) {
 855                 ti = dm_table_get_target(t, i);
 856
 857                 if (!ti->type->direct_access)
 858                         return false;
 859
 860                 if (!ti->type->iterate_devices ||
 861                     ti->type->iterate_devices(ti, iterate_fn, blocksize))
 862                         return false;
 863         }
 864
 865         return true;
 866 }
 867
 868 static int device_is_rq_stackable(struct dm_target *ti, struct dm_dev *dev,
 869                                   sector_t start, sector_t len, void *data)
 870 {
 871         struct block_device *bdev = dev->bdev;
 872         struct request_queue *q = bdev_get_queue(bdev);
 873
 874         /* request-based cannot stack on partitions! */
 875         if (bdev_is_partition(bdev))
 876                 return false;
 877
 878         return queue_is_mq(q);
 879 }
 880
 881 static int dm_table_determine_type(struct dm_table *t)
 882 {
 883         unsigned i;
 884         unsigned bio_based = 0, request_based = 0, hybrid = 0;
 885         struct dm_target *tgt;
 886         struct list_head *devices = dm_table_get_devices(t);
 887         enum dm_queue_mode live_md_type = dm_get_md_type(t->md);
 888         int page_size = PAGE_SIZE;
 889
 890         if (t->type != DM_TYPE_NONE) {
 891                 /* target already set the table's type */
 892                 if (t->type == DM_TYPE_BIO_BASED) {
 893                         /* possibly upgrade to a variant of bio-based */
 894                         goto verify_bio_based;
 895                 }
 896                 BUG_ON(t->type == DM_TYPE_DAX_BIO_BASED);
 897                 goto verify_rq_based;
 898         }
 899
 900         for (i = 0; i < t->num_targets; i++) {
 901                 tgt = t->targets + i;
 902                 if (dm_target_hybrid(tgt))
 903                         hybrid = 1;
 904                 else if (dm_target_request_based(tgt))
 905                         request_based = 1;
 906                 else
 907                         bio_based = 1;
 908
 909                 if (bio_based && request_based) {
 910                         DMERR("Inconsistent table: different target types"
 911                               " can't be mixed up");
 912                         return -EINVAL;
 913                 }
 914         }
 915
 916         if (hybrid && !bio_based && !request_based) {
 917                 /*
 918                  * The targets can work either way.
 919                  * Determine the type from the live device.
 920                  * Default to bio-based if device is new.
 921                  */
 922                 if (__table_type_request_based(live_md_type))
 923                         request_based = 1;
 924                 else
 925                         bio_based = 1;
 926         }
 927
 928         if (bio_based) {
 929 verify_bio_based:
 930                 /* We must use this table as bio-based */
 931                 t->type = DM_TYPE_BIO_BASED;
 932                 if (dm_table_supports_dax(t, device_not_dax_capable, &page_size) ||
 933                     (list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED)) {
 934                         t->type = DM_TYPE_DAX_BIO_BASED;
 935                 }
 936                 return 0;
 937         }
 938
 939         BUG_ON(!request_based); /* No targets in this table */
 940
 941         t->type = DM_TYPE_REQUEST_BASED;
 942
 943 verify_rq_based:
 944         /*
 945          * Request-based dm supports only tables that have a single target now.
 946          * To support multiple targets, request splitting support is needed,
 947          * and that needs lots of changes in the block-layer.
 948          * (e.g. request completion process for partial completion.)
 949          */
 950         if (t->num_targets > 1) {
 951                 DMERR("request-based DM doesn't support multiple targets");
 952                 return -EINVAL;
 953         }
 954
 955         if (list_empty(devices)) {
 956                 int srcu_idx;
 957                 struct dm_table *live_table = dm_get_live_table(t->md, &srcu_idx);
 958
 959                 /* inherit live table's type */
 960                 if (live_table)
 961                         t->type = live_table->type;
 962                 dm_put_live_table(t->md, srcu_idx);
 963                 return 0;
 964         }
 965
 966         tgt = dm_table_get_immutable_target(t);
 967         if (!tgt) {
 968                 DMERR("table load rejected: immutable target is required");
 969                 return -EINVAL;
 970         } else if (tgt->max_io_len) {
 971                 DMERR("table load rejected: immutable target that splits IO is not supported");
 972                 return -EINVAL;
 973         }
 974
 975         /* Non-request-stackable devices can't be used for request-based dm */
 976         if (!tgt->type->iterate_devices ||
 977             !tgt->type->iterate_devices(tgt, device_is_rq_stackable, NULL)) {
 978                 DMERR("table load rejected: including non-request-stackable devices");
 979                 return -EINVAL;
 980         }
 981
 982         return 0;
 983 }
 984
 985 enum dm_queue_mode dm_table_get_type(struct dm_table *t)
 986 {
 987         return t->type;
 988 }
 989
 990 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
 991 {
 992         return t->immutable_target_type;
 993 }
 994
 995 struct dm_target *dm_table_get_immutable_target(struct dm_table *t)
 996 {
 997         /* Immutable target is implicitly a singleton */
 998         if (t->num_targets > 1 ||
 999             !dm_target_is_immutable(t->targets[0].type))
1000                 return NULL;
1001
1002         return t->targets;
1003 }
1004
1005 struct dm_target *dm_table_get_wildcard_target(struct dm_table *t)
1006 {
1007         struct dm_target *ti;
1008         unsigned i;
1009
1010         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1011                 ti = dm_table_get_target(t, i);
1012                 if (dm_target_is_wildcard(ti->type))
1013                         return ti;
1014         }
1015
1016         return NULL;
1017 }
1018
1019 bool dm_table_bio_based(struct dm_table *t)
1020 {
1021         return __table_type_bio_based(dm_table_get_type(t));
1022 }
1023
1024 bool dm_table_request_based(struct dm_table *t)
1025 {
1026         return __table_type_request_based(dm_table_get_type(t));
1027 }
1028
1029 static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device *md)
1030 {
1031         enum dm_queue_mode type = dm_table_get_type(t);
1032         unsigned per_io_data_size = 0;
1033         unsigned min_pool_size = 0;
1034         struct dm_target *ti;
1035         unsigned i;
1036
1037         if (unlikely(type == DM_TYPE_NONE)) {
1038                 DMWARN("no table type is set, can't allocate mempools");
1039                 return -EINVAL;
1040         }
1041
1042         if (__table_type_bio_based(type))
1043                 for (i = 0; i < t->num_targets; i++) {
1044                         ti = t->targets + i;
1045                         per_io_data_size = max(per_io_data_size, ti->per_io_data_size);
1046                         min_pool_size = max(min_pool_size, ti->num_flush_bios);
1047                 }
1048
1049         t->mempools = dm_alloc_md_mempools(md, type, t->integrity_supported,
1050                                            per_io_data_size, min_pool_size);
1051         if (!t->mempools)
1052                 return -ENOMEM;
1053
1054         return 0;
1055 }
1056
1057 void dm_table_free_md_mempools(struct dm_table *t)
1058 {
1059         dm_free_md_mempools(t->mempools);
1060         t->mempools = NULL;
1061 }
1062
1063 struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t)
1064 {
1065         return t->mempools;
1066 }
1067
1068 static int setup_indexes(struct dm_table *t)
1069 {
1070         int i;
1071         unsigned int total = 0;
1072         sector_t *indexes;
1073
1074         /* allocate the space for *all* the indexes */
1075         for (i = t->depth - 2; i >= 0; i--) {
1076                 t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
1077                 total += t->counts[i];
1078         }
1079
1080         indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE);
1081         if (!indexes)
1082                 return -ENOMEM;
1083
1084         /* set up internal nodes, bottom-up */
1085         for (i = t->depth - 2; i >= 0; i--) {
1086                 t->index[i] = indexes;
1087                 indexes += (KEYS_PER_NODE * t->counts[i]);
1088                 setup_btree_index(i, t);
1089         }
1090
1091         return 0;
1092 }
1093
1094 /*
1095  * Builds the btree to index the map.
1096  */
1097 static int dm_table_build_index(struct dm_table *t)
1098 {
1099         int r = 0;
1100         unsigned int leaf_nodes;
1101
1102         /* how many indexes will the btree have ? */
1103         leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
1104         t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
1105
1106         /* leaf layer has already been set up */
1107         t->counts[t->depth - 1] = leaf_nodes;
1108         t->index[t->depth - 1] = t->highs;
1109
1110         if (t->depth >= 2)
1111                 r = setup_indexes(t);
1112
1113         return r;
1114 }
1115
1116 static bool integrity_profile_exists(struct gendisk *disk)
1117 {
1118         return !!blk_get_integrity(disk);
1119 }
1120
1121 /*
1122  * Get a disk whose integrity profile reflects the table's profile.
1123  * Returns NULL if integrity support was inconsistent or unavailable.
1124  */
1125 static struct gendisk * dm_table_get_integrity_disk(struct dm_table *t)
1126 {
1127         struct list_head *devices = dm_table_get_devices(t);
1128         struct dm_dev_internal *dd = NULL;
1129         struct gendisk *prev_disk = NULL, *template_disk = NULL;
1130         unsigned i;
1131
1132         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1133                 struct dm_target *ti = dm_table_get_target(t, i);
1134                 if (!dm_target_passes_integrity(ti->type))
1135                         goto no_integrity;
1136         }
1137
1138         list_for_each_entry(dd, devices, list) {
1139                 template_disk = dd->dm_dev->bdev->bd_disk;
1140                 if (!integrity_profile_exists(template_disk))
1141                         goto no_integrity;
1142                 else if (prev_disk &&
1143                          blk_integrity_compare(prev_disk, template_disk) < 0)
1144                         goto no_integrity;
1145                 prev_disk = template_disk;
1146         }
1147
1148         return template_disk;
1149
1150 no_integrity:
1151         if (prev_disk)
1152                 DMWARN("%s: integrity not set: %s and %s profile mismatch",
1153                        dm_device_name(t->md),
1154                        prev_disk->disk_name,
1155                        template_disk->disk_name);
1156         return NULL;
1157 }
1158
1159 /*
1160  * Register the mapped device for blk_integrity support if the
1161  * underlying devices have an integrity profile.  But all devices may
1162  * not have matching profiles (checking all devices isn't reliable
1163  * during table load because this table may use other DM device(s) which
1164  * must be resumed before they will have an initialized integity
1165  * profile).  Consequently, stacked DM devices force a 2 stage integrity
1166  * profile validation: First pass during table load, final pass during
1167  * resume.
1168  */
1169 static int dm_table_register_integrity(struct dm_table *t)
1170 {
1171         struct mapped_device *md = t->md;
1172         struct gendisk *template_disk = NULL;
1173
1174         /* If target handles integrity itself do not register it here. */
1175         if (t->integrity_added)
1176                 return 0;
1177
1178         template_disk = dm_table_get_integrity_disk(t);
1179         if (!template_disk)
1180                 return 0;
1181
1182         if (!integrity_profile_exists(dm_disk(md))) {
1183                 t->integrity_supported = true;
1184                 /*
1185                  * Register integrity profile during table load; we can do
1186                  * this because the final profile must match during resume.
1187                  */
1188                 blk_integrity_register(dm_disk(md),
1189                                        blk_get_integrity(template_disk));
1190                 return 0;
1191         }
1192
1193         /*
1194          * If DM device already has an initialized integrity
1195          * profile the new profile should not conflict.
1196          */
1197         if (blk_integrity_compare(dm_disk(md), template_disk) < 0) {
1198                 DMWARN("%s: conflict with existing integrity profile: "
1199                        "%s profile mismatch",
1200                        dm_device_name(t->md),
1201                        template_disk->disk_name);
1202                 return 1;
1203         }
1204
1205         /* Preserve existing integrity profile */
1206         t->integrity_supported = true;
1207         return 0;
1208 }
1209
1210 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
1211
1212 struct dm_keyslot_manager {
1213         struct blk_keyslot_manager ksm;
1214         struct mapped_device *md;
1215 };
1216
1217 struct dm_keyslot_evict_args {
1218         const struct blk_crypto_key *key;
1219         int err;
1220 };
1221
1222 static int dm_keyslot_evict_callback(struct dm_target *ti, struct dm_dev *dev,
1223                                      sector_t start, sector_t len, void *data)
1224 {
1225         struct dm_keyslot_evict_args *args = data;
1226         int err;
1227
1228         err = blk_crypto_evict_key(bdev_get_queue(dev->bdev), args->key);
1229         if (!args->err)
1230                 args->err = err;
1231         /* Always try to evict the key from all devices. */
1232         return 0;
1233 }
1234
1235 /*
1236  * When an inline encryption key is evicted from a device-mapper device, evict
1237  * it from all the underlying devices.
1238  */
1239 static int dm_keyslot_evict(struct blk_keyslot_manager *ksm,
1240                             const struct blk_crypto_key *key, unsigned int slot)
1241 {
1242         struct dm_keyslot_manager *dksm = container_of(ksm,
1243                                                        struct dm_keyslot_manager,
1244                                                        ksm);
1245         struct mapped_device *md = dksm->md;
1246         struct dm_keyslot_evict_args args = { key };
1247         struct dm_table *t;
1248         int srcu_idx;
1249         int i;
1250         struct dm_target *ti;
1251
1252         t = dm_get_live_table(md, &srcu_idx);
1253         if (!t)
1254                 return 0;
1255         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1256                 ti = dm_table_get_target(t, i);
1257                 if (!ti->type->iterate_devices)
1258                         continue;
1259                 ti->type->iterate_devices(ti, dm_keyslot_evict_callback, &args);
1260         }
1261         dm_put_live_table(md, srcu_idx);
1262         return args.err;
1263 }
1264
1265 static struct blk_ksm_ll_ops dm_ksm_ll_ops = {
1266         .keyslot_evict = dm_keyslot_evict,
1267 };
1268
1269 static int device_intersect_crypto_modes(struct dm_target *ti,
1270                                          struct dm_dev *dev, sector_t start,
1271                                          sector_t len, void *data)
1272 {
1273         struct blk_keyslot_manager *parent = data;
1274         struct blk_keyslot_manager *child = bdev_get_queue(dev->bdev)->ksm;
1275
1276         blk_ksm_intersect_modes(parent, child);
1277         return 0;
1278 }
1279
1280 void dm_destroy_keyslot_manager(struct blk_keyslot_manager *ksm)
1281 {
1282         struct dm_keyslot_manager *dksm = container_of(ksm,
1283                                                        struct dm_keyslot_manager,
1284                                                        ksm);
1285
1286         if (!ksm)
1287                 return;
1288
1289         blk_ksm_destroy(ksm);
1290         kfree(dksm);
1291 }
1292
1293 static void dm_table_destroy_keyslot_manager(struct dm_table *t)
1294 {
1295         dm_destroy_keyslot_manager(t->ksm);
1296         t->ksm = NULL;
1297 }
1298
1299 /*
1300  * Constructs and initializes t->ksm with a keyslot manager that
1301  * represents the common set of crypto capabilities of the devices
1302  * described by the dm_table. However, if the constructed keyslot
1303  * manager does not support a superset of the crypto capabilities
1304  * supported by the current keyslot manager of the mapped_device,
1305  * it returns an error instead, since we don't support restricting
1306  * crypto capabilities on table changes. Finally, if the constructed
1307  * keyslot manager doesn't actually support any crypto modes at all,
1308  * it just returns NULL.
1309  */
1310 static int dm_table_construct_keyslot_manager(struct dm_table *t)
1311 {
1312         struct dm_keyslot_manager *dksm;
1313         struct blk_keyslot_manager *ksm;
1314         struct dm_target *ti;
1315         unsigned int i;
1316         bool ksm_is_empty = true;
1317
1318         dksm = kmalloc(sizeof(*dksm), GFP_KERNEL);
1319         if (!dksm)
1320                 return -ENOMEM;
1321         dksm->md = t->md;
1322
1323         ksm = &dksm->ksm;
1324         blk_ksm_init_passthrough(ksm);
1325         ksm->ksm_ll_ops = dm_ksm_ll_ops;
1326         ksm->max_dun_bytes_supported = UINT_MAX;
1327         memset(ksm->crypto_modes_supported, 0xFF,
1328                sizeof(ksm->crypto_modes_supported));
1329
1330         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1331                 ti = dm_table_get_target(t, i);
1332
1333                 if (!dm_target_passes_crypto(ti->type)) {
1334                         blk_ksm_intersect_modes(ksm, NULL);
1335                         break;
1336                 }
1337                 if (!ti->type->iterate_devices)
1338                         continue;
1339                 ti->type->iterate_devices(ti, device_intersect_crypto_modes,
1340                                           ksm);
1341         }
1342
1343         if (t->md->queue && !blk_ksm_is_superset(ksm, t->md->queue->ksm)) {
1344                 DMWARN("Inline encryption capabilities of new DM table were more restrictive than the old table's. This is not supported!");
1345                 dm_destroy_keyslot_manager(ksm);
1346                 return -EINVAL;
1347         }
1348
1349         /*
1350          * If the new KSM doesn't actually support any crypto modes, we may as
1351          * well represent it with a NULL ksm.
1352          */
1353         ksm_is_empty = true;
1354         for (i = 0; i < ARRAY_SIZE(ksm->crypto_modes_supported); i++) {
1355                 if (ksm->crypto_modes_supported[i]) {
1356                         ksm_is_empty = false;
1357                         break;
1358                 }
1359         }
1360
1361         if (ksm_is_empty) {
1362                 dm_destroy_keyslot_manager(ksm);
1363                 ksm = NULL;
1364         }
1365
1366         /*
1367          * t->ksm is only set temporarily while the table is being set
1368          * up, and it gets set to NULL after the capabilities have
1369          * been transferred to the request_queue.
1370          */
1371         t->ksm = ksm;
1372
1373         return 0;
1374 }
1375
1376 static void dm_update_keyslot_manager(struct request_queue *q,
1377                                       struct dm_table *t)
1378 {
1379         if (!t->ksm)
1380                 return;
1381
1382         /* Make the ksm less restrictive */
1383         if (!q->ksm) {
1384                 blk_ksm_register(t->ksm, q);
1385         } else {
1386                 blk_ksm_update_capabilities(q->ksm, t->ksm);
1387                 dm_destroy_keyslot_manager(t->ksm);
1388         }
1389         t->ksm = NULL;
1390 }
1391
1392 #else /* CONFIG_BLK_INLINE_ENCRYPTION */
1393
1394 static int dm_table_construct_keyslot_manager(struct dm_table *t)
1395 {
1396         return 0;
1397 }
1398
1399 void dm_destroy_keyslot_manager(struct blk_keyslot_manager *ksm)
1400 {
1401 }
1402
1403 static void dm_table_destroy_keyslot_manager(struct dm_table *t)
1404 {
1405 }
1406
1407 static void dm_update_keyslot_manager(struct request_queue *q,
1408                                       struct dm_table *t)
1409 {
1410 }
1411
1412 #endif /* !CONFIG_BLK_INLINE_ENCRYPTION */
1413
1414 /*
1415  * Prepares the table for use by building the indices,
1416  * setting the type, and allocating mempools.
1417  */
1418 int dm_table_complete(struct dm_table *t)
1419 {
1420         int r;
1421
1422         r = dm_table_determine_type(t);
1423         if (r) {
1424                 DMERR("unable to determine table type");
1425                 return r;
1426         }
1427
1428         r = dm_table_build_index(t);
1429         if (r) {
1430                 DMERR("unable to build btrees");
1431                 return r;
1432         }
1433
1434         r = dm_table_register_integrity(t);
1435         if (r) {
1436                 DMERR("could not register integrity profile.");
1437                 return r;
1438         }
1439
1440         r = dm_table_construct_keyslot_manager(t);
1441         if (r) {
1442                 DMERR("could not construct keyslot manager.");
1443                 return r;
1444         }
1445
1446         r = dm_table_alloc_md_mempools(t, t->md);
1447         if (r)
1448                 DMERR("unable to allocate mempools");
1449
1450         return r;
1451 }
1452
1453 static DEFINE_MUTEX(_event_lock);
1454 void dm_table_event_callback(struct dm_table *t,
1455                              void (*fn)(void *), void *context)
1456 {
1457         mutex_lock(&_event_lock);
1458         t->event_fn = fn;
1459         t->event_context = context;
1460         mutex_unlock(&_event_lock);
1461 }
1462
1463 void dm_table_event(struct dm_table *t)
1464 {
1465         mutex_lock(&_event_lock);
1466         if (t->event_fn)
1467                 t->event_fn(t->event_context);
1468         mutex_unlock(&_event_lock);
1469 }
1470 EXPORT_SYMBOL(dm_table_event);
1471
1472 inline sector_t dm_table_get_size(struct dm_table *t)
1473 {
1474         return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1475 }
1476 EXPORT_SYMBOL(dm_table_get_size);
1477
1478 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index)
1479 {
1480         if (index >= t->num_targets)
1481                 return NULL;
1482
1483         return t->targets + index;
1484 }
1485
1486 /*
1487  * Search the btree for the correct target.
1488  *
1489  * Caller should check returned pointer for NULL
1490  * to trap I/O beyond end of device.
1491  */
1492 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1493 {
1494         unsigned int l, n = 0, k = 0;
1495         sector_t *node;
1496
1497         if (unlikely(sector >= dm_table_get_size(t)))
1498                 return NULL;
1499
1500         for (l = 0; l < t->depth; l++) {
1501                 n = get_child(n, k);
1502                 node = get_node(t, l, n);
1503
1504                 for (k = 0; k < KEYS_PER_NODE; k++)
1505                         if (node[k] >= sector)
1506                                 break;
1507         }
1508
1509         return &t->targets[(KEYS_PER_NODE * n) + k];
1510 }
1511
1512 /*
1513  * type->iterate_devices() should be called when the sanity check needs to
1514  * iterate and check all underlying data devices. iterate_devices() will
1515  * iterate all underlying data devices until it encounters a non-zero return
1516  * code, returned by whether the input iterate_devices_callout_fn, or
1517  * iterate_devices() itself internally.
1518  *
1519  * For some target type (e.g. dm-stripe), one call of iterate_devices() may
1520  * iterate multiple underlying devices internally, in which case a non-zero
1521  * return code returned by iterate_devices_callout_fn will stop the iteration
1522  * in advance.
1523  *
1524  * Cases requiring _any_ underlying device supporting some kind of attribute,
1525  * should use the iteration structure like dm_table_any_dev_attr(), or call
1526  * it directly. @func should handle semantics of positive examples, e.g.
1527  * capable of something.
1528  *
1529  * Cases requiring _all_ underlying devices supporting some kind of attribute,
1530  * should use the iteration structure like dm_table_supports_nowait() or
1531  * dm_table_supports_discards(). Or introduce dm_table_all_devs_attr() that
1532  * uses an @anti_func that handle semantics of counter examples, e.g. not
1533  * capable of something. So: return !dm_table_any_dev_attr(t, anti_func, data);
1534  */
1535 static bool dm_table_any_dev_attr(struct dm_table *t,
1536                                   iterate_devices_callout_fn func, void *data)
1537 {
1538         struct dm_target *ti;
1539         unsigned int i;
1540
1541         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1542                 ti = dm_table_get_target(t, i);
1543
1544                 if (ti->type->iterate_devices &&
1545                     ti->type->iterate_devices(ti, func, data))
1546                         return true;
1547         }
1548
1549         return false;
1550 }
1551
1552 static int count_device(struct dm_target *ti, struct dm_dev *dev,
1553                         sector_t start, sector_t len, void *data)
1554 {
1555         unsigned *num_devices = data;
1556
1557         (*num_devices)++;
1558
1559         return 0;
1560 }
1561
1562 /*
1563  * Check whether a table has no data devices attached using each
1564  * target's iterate_devices method.
1565  * Returns false if the result is unknown because a target doesn't
1566  * support iterate_devices.
1567  */
1568 bool dm_table_has_no_data_devices(struct dm_table *table)
1569 {
1570         struct dm_target *ti;
1571         unsigned i, num_devices;
1572
1573         for (i = 0; i < dm_table_get_num_targets(table); i++) {
1574                 ti = dm_table_get_target(table, i);
1575
1576                 if (!ti->type->iterate_devices)
1577                         return false;
1578
1579                 num_devices = 0;
1580                 ti->type->iterate_devices(ti, count_device, &num_devices);
1581                 if (num_devices)
1582                         return false;
1583         }
1584
1585         return true;
1586 }
1587
1588 static int device_not_zoned_model(struct dm_target *ti, struct dm_dev *dev,
1589                                   sector_t start, sector_t len, void *data)
1590 {
1591         struct request_queue *q = bdev_get_queue(dev->bdev);
1592         enum blk_zoned_model *zoned_model = data;
1593
1594         return blk_queue_zoned_model(q) != *zoned_model;
1595 }
1596
1597 static bool dm_table_supports_zoned_model(struct dm_table *t,
1598                                           enum blk_zoned_model zoned_model)
1599 {
1600         struct dm_target *ti;
1601         unsigned i;
1602
1603         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1604                 ti = dm_table_get_target(t, i);
1605
1606                 if (zoned_model == BLK_ZONED_HM &&
1607                     !dm_target_supports_zoned_hm(ti->type))
1608                         return false;
1609
1610                 if (!ti->type->iterate_devices ||
1611                     ti->type->iterate_devices(ti, device_not_zoned_model, &zoned_model))
1612                         return false;
1613         }
1614
1615         return true;
1616 }
1617
1618 static int device_not_matches_zone_sectors(struct dm_target *ti, struct dm_dev *dev,
1619                                            sector_t start, sector_t len, void *data)
1620 {
1621         struct request_queue *q = bdev_get_queue(dev->bdev);
1622         unsigned int *zone_sectors = data;
1623
1624         return blk_queue_zone_sectors(q) != *zone_sectors;
1625 }
1626
1627 static int validate_hardware_zoned_model(struct dm_table *table,
1628                                          enum blk_zoned_model zoned_model,
1629                                          unsigned int zone_sectors)
1630 {
1631         if (zoned_model == BLK_ZONED_NONE)
1632                 return 0;
1633
1634         if (!dm_table_supports_zoned_model(table, zoned_model)) {
1635                 DMERR("%s: zoned model is not consistent across all devices",
1636                       dm_device_name(table->md));
1637                 return -EINVAL;
1638         }
1639
1640         /* Check zone size validity and compatibility */
1641         if (!zone_sectors || !is_power_of_2(zone_sectors))
1642                 return -EINVAL;
1643
1644         if (dm_table_any_dev_attr(table, device_not_matches_zone_sectors, &zone_sectors)) {
1645                 DMERR("%s: zone sectors is not consistent across all devices",
1646                       dm_device_name(table->md));
1647                 return -EINVAL;
1648         }
1649
1650         return 0;
1651 }
1652
1653 /*
1654  * Establish the new table's queue_limits and validate them.
1655  */
1656 int dm_calculate_queue_limits(struct dm_table *table,
1657                               struct queue_limits *limits)
1658 {
1659         struct dm_target *ti;
1660         struct queue_limits ti_limits;
1661         unsigned i;
1662         enum blk_zoned_model zoned_model = BLK_ZONED_NONE;
1663         unsigned int zone_sectors = 0;
1664
1665         blk_set_stacking_limits(limits);
1666
1667         for (i = 0; i < dm_table_get_num_targets(table); i++) {
1668                 blk_set_stacking_limits(&ti_limits);
1669
1670                 ti = dm_table_get_target(table, i);
1671
1672                 if (!ti->type->iterate_devices)
1673                         goto combine_limits;
1674
1675                 /*
1676                  * Combine queue limits of all the devices this target uses.
1677                  */
1678                 ti->type->iterate_devices(ti, dm_set_device_limits,
1679                                           &ti_limits);
1680
1681                 if (zoned_model == BLK_ZONED_NONE && ti_limits.zoned != BLK_ZONED_NONE) {
1682                         /*
1683                          * After stacking all limits, validate all devices
1684                          * in table support this zoned model and zone sectors.
1685                          */
1686                         zoned_model = ti_limits.zoned;
1687                         zone_sectors = ti_limits.chunk_sectors;
1688                 }
1689
1690                 /* Set I/O hints portion of queue limits */
1691                 if (ti->type->io_hints)
1692                         ti->type->io_hints(ti, &ti_limits);
1693
1694                 /*
1695                  * Check each device area is consistent with the target's
1696                  * overall queue limits.
1697                  */
1698                 if (ti->type->iterate_devices(ti, device_area_is_invalid,
1699                                               &ti_limits))
1700                         return -EINVAL;
1701
1702 combine_limits:
1703                 /*
1704                  * Merge this target's queue limits into the overall limits
1705                  * for the table.
1706                  */
1707                 if (blk_stack_limits(limits, &ti_limits, 0) < 0)
1708                         DMWARN("%s: adding target device "
1709                                "(start sect %llu len %llu) "
1710                                "caused an alignment inconsistency",
1711                                dm_device_name(table->md),
1712                                (unsigned long long) ti->begin,
1713                                (unsigned long long) ti->len);
1714         }
1715
1716         /*
1717          * Verify that the zoned model and zone sectors, as determined before
1718          * any .io_hints override, are the same across all devices in the table.
1719          * - this is especially relevant if .io_hints is emulating a disk-managed
1720          *   zoned model (aka BLK_ZONED_NONE) on host-managed zoned block devices.
1721          * BUT...
1722          */
1723         if (limits->zoned != BLK_ZONED_NONE) {
1724                 /*
1725                  * ...IF the above limits stacking determined a zoned model
1726                  * validate that all of the table's devices conform to it.
1727                  */
1728                 zoned_model = limits->zoned;
1729                 zone_sectors = limits->chunk_sectors;
1730         }
1731         if (validate_hardware_zoned_model(table, zoned_model, zone_sectors))
1732                 return -EINVAL;
1733
1734         return validate_hardware_logical_block_alignment(table, limits);
1735 }
1736
1737 /*
1738  * Verify that all devices have an integrity profile that matches the
1739  * DM device's registered integrity profile.  If the profiles don't
1740  * match then unregister the DM device's integrity profile.
1741  */
1742 static void dm_table_verify_integrity(struct dm_table *t)
1743 {
1744         struct gendisk *template_disk = NULL;
1745
1746         if (t->integrity_added)
1747                 return;
1748
1749         if (t->integrity_supported) {
1750                 /*
1751                  * Verify that the original integrity profile
1752                  * matches all the devices in this table.
1753                  */
1754                 template_disk = dm_table_get_integrity_disk(t);
1755                 if (template_disk &&
1756                     blk_integrity_compare(dm_disk(t->md), template_disk) >= 0)
1757                         return;
1758         }
1759
1760         if (integrity_profile_exists(dm_disk(t->md))) {
1761                 DMWARN("%s: unable to establish an integrity profile",
1762                        dm_device_name(t->md));
1763                 blk_integrity_unregister(dm_disk(t->md));
1764         }
1765 }
1766
1767 static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
1768                                 sector_t start, sector_t len, void *data)
1769 {
1770         unsigned long flush = (unsigned long) data;
1771         struct request_queue *q = bdev_get_queue(dev->bdev);
1772
1773         return (q->queue_flags & flush);
1774 }
1775
1776 static bool dm_table_supports_flush(struct dm_table *t, unsigned long flush)
1777 {
1778         struct dm_target *ti;
1779         unsigned i;
1780
1781         /*
1782          * Require at least one underlying device to support flushes.
1783          * t->devices includes internal dm devices such as mirror logs
1784          * so we need to use iterate_devices here, which targets
1785          * supporting flushes must provide.
1786          */
1787         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1788                 ti = dm_table_get_target(t, i);
1789
1790                 if (!ti->num_flush_bios)
1791                         continue;
1792
1793                 if (ti->flush_supported)
1794                         return true;
1795
1796                 if (ti->type->iterate_devices &&
1797                     ti->type->iterate_devices(ti, device_flush_capable, (void *) flush))
1798                         return true;
1799         }
1800
1801         return false;
1802 }
1803
1804 static int device_dax_write_cache_enabled(struct dm_target *ti,
1805                                           struct dm_dev *dev, sector_t start,
1806                                           sector_t len, void *data)
1807 {
1808         struct dax_device *dax_dev = dev->dax_dev;
1809
1810         if (!dax_dev)
1811                 return false;
1812
1813         if (dax_write_cache_enabled(dax_dev))
1814                 return true;
1815         return false;
1816 }
1817
1818 static int device_is_rotational(struct dm_target *ti, struct dm_dev *dev,
1819                                 sector_t start, sector_t len, void *data)
1820 {
1821         struct request_queue *q = bdev_get_queue(dev->bdev);
1822
1823         return !blk_queue_nonrot(q);
1824 }
1825
1826 static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
1827                              sector_t start, sector_t len, void *data)
1828 {
1829         struct request_queue *q = bdev_get_queue(dev->bdev);
1830
1831         return !blk_queue_add_random(q);
1832 }
1833
1834 static int device_not_write_same_capable(struct dm_target *ti, struct dm_dev *dev,
1835                                          sector_t start, sector_t len, void *data)
1836 {
1837         struct request_queue *q = bdev_get_queue(dev->bdev);
1838
1839         return !q->limits.max_write_same_sectors;
1840 }
1841
1842 static bool dm_table_supports_write_same(struct dm_table *t)
1843 {
1844         struct dm_target *ti;
1845         unsigned i;
1846
1847         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1848                 ti = dm_table_get_target(t, i);
1849
1850                 if (!ti->num_write_same_bios)
1851                         return false;
1852
1853                 if (!ti->type->iterate_devices ||
1854                     ti->type->iterate_devices(ti, device_not_write_same_capable, NULL))
1855                         return false;
1856         }
1857
1858         return true;
1859 }
1860
1861 static int device_not_write_zeroes_capable(struct dm_target *ti, struct dm_dev *dev,
1862                                            sector_t start, sector_t len, void *data)
1863 {
1864         struct request_queue *q = bdev_get_queue(dev->bdev);
1865
1866         return !q->limits.max_write_zeroes_sectors;
1867 }
1868
1869 static bool dm_table_supports_write_zeroes(struct dm_table *t)
1870 {
1871         struct dm_target *ti;
1872         unsigned i = 0;
1873
1874         while (i < dm_table_get_num_targets(t)) {
1875                 ti = dm_table_get_target(t, i++);
1876
1877                 if (!ti->num_write_zeroes_bios)
1878                         return false;
1879
1880                 if (!ti->type->iterate_devices ||
1881                     ti->type->iterate_devices(ti, device_not_write_zeroes_capable, NULL))
1882                         return false;
1883         }
1884
1885         return true;
1886 }
1887
1888 static int device_not_nowait_capable(struct dm_target *ti, struct dm_dev *dev,
1889                                      sector_t start, sector_t len, void *data)
1890 {
1891         struct request_queue *q = bdev_get_queue(dev->bdev);
1892
1893         return !blk_queue_nowait(q);
1894 }
1895
1896 static bool dm_table_supports_nowait(struct dm_table *t)
1897 {
1898         struct dm_target *ti;
1899         unsigned i = 0;
1900
1901         while (i < dm_table_get_num_targets(t)) {
1902                 ti = dm_table_get_target(t, i++);
1903
1904                 if (!dm_target_supports_nowait(ti->type))
1905                         return false;
1906
1907                 if (!ti->type->iterate_devices ||
1908                     ti->type->iterate_devices(ti, device_not_nowait_capable, NULL))
1909                         return false;
1910         }
1911
1912         return true;
1913 }
1914
1915 static int device_not_discard_capable(struct dm_target *ti, struct dm_dev *dev,
1916                                       sector_t start, sector_t len, void *data)
1917 {
1918         struct request_queue *q = bdev_get_queue(dev->bdev);
1919
1920         return !blk_queue_discard(q);
1921 }
1922
1923 static bool dm_table_supports_discards(struct dm_table *t)
1924 {
1925         struct dm_target *ti;
1926         unsigned i;
1927
1928         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1929                 ti = dm_table_get_target(t, i);
1930
1931                 if (!ti->num_discard_bios)
1932                         return false;
1933
1934                 /*
1935                  * Either the target provides discard support (as implied by setting
1936                  * 'discards_supported') or it relies on _all_ data devices having
1937                  * discard support.
1938                  */
1939                 if (!ti->discards_supported &&
1940                     (!ti->type->iterate_devices ||
1941                      ti->type->iterate_devices(ti, device_not_discard_capable, NULL)))
1942                         return false;
1943         }
1944
1945         return true;
1946 }
1947
1948 static int device_not_secure_erase_capable(struct dm_target *ti,
1949                                            struct dm_dev *dev, sector_t start,
1950                                            sector_t len, void *data)
1951 {
1952         struct request_queue *q = bdev_get_queue(dev->bdev);
1953
1954         return !blk_queue_secure_erase(q);
1955 }
1956
1957 static bool dm_table_supports_secure_erase(struct dm_table *t)
1958 {
1959         struct dm_target *ti;
1960         unsigned int i;
1961
1962         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1963                 ti = dm_table_get_target(t, i);
1964
1965                 if (!ti->num_secure_erase_bios)
1966                         return false;
1967
1968                 if (!ti->type->iterate_devices ||
1969                     ti->type->iterate_devices(ti, device_not_secure_erase_capable, NULL))
1970                         return false;
1971         }
1972
1973         return true;
1974 }
1975
1976 static int device_requires_stable_pages(struct dm_target *ti,
1977                                         struct dm_dev *dev, sector_t start,
1978                                         sector_t len, void *data)
1979 {
1980         struct request_queue *q = bdev_get_queue(dev->bdev);
1981
1982         return blk_queue_stable_writes(q);
1983 }
1984
1985 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1986                                struct queue_limits *limits)
1987 {
1988         bool wc = false, fua = false;
1989         int page_size = PAGE_SIZE;
1990
1991         /*
1992          * Copy table's limits to the DM device's request_queue
1993          */
1994         q->limits = *limits;
1995
1996         if (dm_table_supports_nowait(t))
1997                 blk_queue_flag_set(QUEUE_FLAG_NOWAIT, q);
1998         else
1999                 blk_queue_flag_clear(QUEUE_FLAG_NOWAIT, q);
2000
2001         if (!dm_table_supports_discards(t)) {
2002                 blk_queue_flag_clear(QUEUE_FLAG_DISCARD, q);
2003                 /* Must also clear discard limits... */
2004                 q->limits.max_discard_sectors = 0;
2005                 q->limits.max_hw_discard_sectors = 0;
2006                 q->limits.discard_granularity = 0;
2007                 q->limits.discard_alignment = 0;
2008                 q->limits.discard_misaligned = 0;
2009         } else
2010                 blk_queue_flag_set(QUEUE_FLAG_DISCARD, q);
2011
2012         if (dm_table_supports_secure_erase(t))
2013                 blk_queue_flag_set(QUEUE_FLAG_SECERASE, q);
2014
2015         if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_WC))) {
2016                 wc = true;
2017                 if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_FUA)))
2018                         fua = true;
2019         }
2020         blk_queue_write_cache(q, wc, fua);
2021
2022         if (dm_table_supports_dax(t, device_not_dax_capable, &page_size)) {
2023                 blk_queue_flag_set(QUEUE_FLAG_DAX, q);
2024                 if (dm_table_supports_dax(t, device_not_dax_synchronous_capable, NULL))
2025                         set_dax_synchronous(t->md->dax_dev);
2026         }
2027         else
2028                 blk_queue_flag_clear(QUEUE_FLAG_DAX, q);
2029
2030         if (dm_table_any_dev_attr(t, device_dax_write_cache_enabled, NULL))
2031                 dax_write_cache(t->md->dax_dev, true);
2032
2033         /* Ensure that all underlying devices are non-rotational. */
2034         if (dm_table_any_dev_attr(t, device_is_rotational, NULL))
2035                 blk_queue_flag_clear(QUEUE_FLAG_NONROT, q);
2036         else
2037                 blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
2038
2039         if (!dm_table_supports_write_same(t))
2040                 q->limits.max_write_same_sectors = 0;
2041         if (!dm_table_supports_write_zeroes(t))
2042                 q->limits.max_write_zeroes_sectors = 0;
2043
2044         dm_table_verify_integrity(t);
2045
2046         /*
2047          * Some devices don't use blk_integrity but still want stable pages
2048          * because they do their own checksumming.
2049          * If any underlying device requires stable pages, a table must require
2050          * them as well.  Only targets that support iterate_devices are considered:
2051          * don't want error, zero, etc to require stable pages.
2052          */
2053         if (dm_table_any_dev_attr(t, device_requires_stable_pages, NULL))
2054                 blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, q);
2055         else
2056                 blk_queue_flag_clear(QUEUE_FLAG_STABLE_WRITES, q);
2057
2058         /*
2059          * Determine whether or not this queue's I/O timings contribute
2060          * to the entropy pool, Only request-based targets use this.
2061          * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
2062          * have it set.
2063          */
2064         if (blk_queue_add_random(q) &&
2065             dm_table_any_dev_attr(t, device_is_not_random, NULL))
2066                 blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, q);
2067
2068         /*
2069          * For a zoned target, the number of zones should be updated for the
2070          * correct value to be exposed in sysfs queue/nr_zones. For a BIO based
2071          * target, this is all that is needed.
2072          */
2073 #ifdef CONFIG_BLK_DEV_ZONED
2074         if (blk_queue_is_zoned(q)) {
2075                 WARN_ON_ONCE(queue_is_mq(q));
2076                 q->nr_zones = blkdev_nr_zones(t->md->disk);
2077         }
2078 #endif
2079
2080         dm_update_keyslot_manager(q, t);
2081         blk_queue_update_readahead(q);
2082 }
2083
2084 unsigned int dm_table_get_num_targets(struct dm_table *t)
2085 {
2086         return t->num_targets;
2087 }
2088
2089 struct list_head *dm_table_get_devices(struct dm_table *t)
2090 {
2091         return &t->devices;
2092 }
2093
2094 fmode_t dm_table_get_mode(struct dm_table *t)
2095 {
2096         return t->mode;
2097 }
2098 EXPORT_SYMBOL(dm_table_get_mode);
2099
2100 enum suspend_mode {
2101         PRESUSPEND,
2102         PRESUSPEND_UNDO,
2103         POSTSUSPEND,
2104 };
2105
2106 static void suspend_targets(struct dm_table *t, enum suspend_mode mode)
2107 {
2108         int i = t->num_targets;
2109         struct dm_target *ti = t->targets;
2110
2111         lockdep_assert_held(&t->md->suspend_lock);
2112
2113         while (i--) {
2114                 switch (mode) {
2115                 case PRESUSPEND:
2116                         if (ti->type->presuspend)
2117                                 ti->type->presuspend(ti);
2118                         break;
2119                 case PRESUSPEND_UNDO:
2120                         if (ti->type->presuspend_undo)
2121                                 ti->type->presuspend_undo(ti);
2122                         break;
2123                 case POSTSUSPEND:
2124                         if (ti->type->postsuspend)
2125                                 ti->type->postsuspend(ti);
2126                         break;
2127                 }
2128                 ti++;
2129         }
2130 }
2131
2132 void dm_table_presuspend_targets(struct dm_table *t)
2133 {
2134         if (!t)
2135                 return;
2136
2137         suspend_targets(t, PRESUSPEND);
2138 }
2139
2140 void dm_table_presuspend_undo_targets(struct dm_table *t)
2141 {
2142         if (!t)
2143                 return;
2144
2145         suspend_targets(t, PRESUSPEND_UNDO);
2146 }
2147
2148 void dm_table_postsuspend_targets(struct dm_table *t)
2149 {
2150         if (!t)
2151                 return;
2152
2153         suspend_targets(t, POSTSUSPEND);
2154 }
2155
2156 int dm_table_resume_targets(struct dm_table *t)
2157 {
2158         int i, r = 0;
2159
2160         lockdep_assert_held(&t->md->suspend_lock);
2161
2162         for (i = 0; i < t->num_targets; i++) {
2163                 struct dm_target *ti = t->targets + i;
2164
2165                 if (!ti->type->preresume)
2166                         continue;
2167
2168                 r = ti->type->preresume(ti);
2169                 if (r) {
2170                         DMERR("%s: %s: preresume failed, error = %d",
2171                               dm_device_name(t->md), ti->type->name, r);
2172                         return r;
2173                 }
2174         }
2175
2176         for (i = 0; i < t->num_targets; i++) {
2177                 struct dm_target *ti = t->targets + i;
2178
2179                 if (ti->type->resume)
2180                         ti->type->resume(ti);
2181         }
2182
2183         return 0;
2184 }
2185
2186 struct mapped_device *dm_table_get_md(struct dm_table *t)
2187 {
2188         return t->md;
2189 }
2190 EXPORT_SYMBOL(dm_table_get_md);
2191
2192 const char *dm_table_device_name(struct dm_table *t)
2193 {
2194         return dm_device_name(t->md);
2195 }
2196 EXPORT_SYMBOL_GPL(dm_table_device_name);
2197
2198 void dm_table_run_md_queue_async(struct dm_table *t)
2199 {
2200         if (!dm_table_request_based(t))
2201                 return;
2202
2203         if (t->md->queue)
2204                 blk_mq_run_hw_queues(t->md->queue, true);
2205 }
2206 EXPORT_SYMBOL(dm_table_run_md_queue_async);
2207