drivers/md/dm-table.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2001 Sistina Software (UK) Limited.
   4  * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
   5  *
   6  * This file is released under the GPL.
   7  */
   8
   9 #include "dm-core.h"
  10 #include "dm-rq.h"
  11
  12 #include <linux/module.h>
  13 #include <linux/vmalloc.h>
  14 #include <linux/blkdev.h>
  15 #include <linux/blk-integrity.h>
  16 #include <linux/namei.h>
  17 #include <linux/ctype.h>
  18 #include <linux/string.h>
  19 #include <linux/slab.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/mutex.h>
  22 #include <linux/delay.h>
  23 #include <linux/atomic.h>
  24 #include <linux/blk-mq.h>
  25 #include <linux/mount.h>
  26 #include <linux/dax.h>
  27
  28 #define DM_MSG_PREFIX "table"
  29
  30 #define NODE_SIZE L1_CACHE_BYTES
  31 #define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t))
  32 #define CHILDREN_PER_NODE (KEYS_PER_NODE + 1)
  33
  34 /*
  35  * Similar to ceiling(log_size(n))
  36  */
  37 static unsigned int int_log(unsigned int n, unsigned int base)
  38 {
  39         int result = 0;
  40
  41         while (n > 1) {
  42                 n = dm_div_up(n, base);
  43                 result++;
  44         }
  45
  46         return result;
  47 }
  48
  49 /*
  50  * Calculate the index of the child node of the n'th node k'th key.
  51  */
  52 static inline unsigned int get_child(unsigned int n, unsigned int k)
  53 {
  54         return (n * CHILDREN_PER_NODE) + k;
  55 }
  56
  57 /*
  58  * Return the n'th node of level l from table t.
  59  */
  60 static inline sector_t *get_node(struct dm_table *t,
  61                                  unsigned int l, unsigned int n)
  62 {
  63         return t->index[l] + (n * KEYS_PER_NODE);
  64 }
  65
  66 /*
  67  * Return the highest key that you could lookup from the n'th
  68  * node on level l of the btree.
  69  */
  70 static sector_t high(struct dm_table *t, unsigned int l, unsigned int n)
  71 {
  72         for (; l < t->depth - 1; l++)
  73                 n = get_child(n, CHILDREN_PER_NODE - 1);
  74
  75         if (n >= t->counts[l])
  76                 return (sector_t) -1;
  77
  78         return get_node(t, l, n)[KEYS_PER_NODE - 1];
  79 }
  80
  81 /*
  82  * Fills in a level of the btree based on the highs of the level
  83  * below it.
  84  */
  85 static int setup_btree_index(unsigned int l, struct dm_table *t)
  86 {
  87         unsigned int n, k;
  88         sector_t *node;
  89
  90         for (n = 0U; n < t->counts[l]; n++) {
  91                 node = get_node(t, l, n);
  92
  93                 for (k = 0U; k < KEYS_PER_NODE; k++)
  94                         node[k] = high(t, l + 1, get_child(n, k));
  95         }
  96
  97         return 0;
  98 }
  99
 100 /*
 101  * highs, and targets are managed as dynamic arrays during a
 102  * table load.
 103  */
 104 static int alloc_targets(struct dm_table *t, unsigned int num)
 105 {
 106         sector_t *n_highs;
 107         struct dm_target *n_targets;
 108
 109         /*
 110          * Allocate both the target array and offset array at once.
 111          */
 112         n_highs = kvcalloc(num, sizeof(struct dm_target) + sizeof(sector_t),
 113                            GFP_KERNEL);
 114         if (!n_highs)
 115                 return -ENOMEM;
 116
 117         n_targets = (struct dm_target *) (n_highs + num);
 118
 119         memset(n_highs, -1, sizeof(*n_highs) * num);
 120         kvfree(t->highs);
 121
 122         t->num_allocated = num;
 123         t->highs = n_highs;
 124         t->targets = n_targets;
 125
 126         return 0;
 127 }
 128
 129 int dm_table_create(struct dm_table **result, fmode_t mode,
 130                     unsigned int num_targets, struct mapped_device *md)
 131 {
 132         struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
 133
 134         if (!t)
 135                 return -ENOMEM;
 136
 137         INIT_LIST_HEAD(&t->devices);
 138
 139         if (!num_targets)
 140                 num_targets = KEYS_PER_NODE;
 141
 142         num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
 143
 144         if (!num_targets) {
 145                 kfree(t);
 146                 return -ENOMEM;
 147         }
 148
 149         if (alloc_targets(t, num_targets)) {
 150                 kfree(t);
 151                 return -ENOMEM;
 152         }
 153
 154         t->type = DM_TYPE_NONE;
 155         t->mode = mode;
 156         t->md = md;
 157         *result = t;
 158         return 0;
 159 }
 160
 161 static void free_devices(struct list_head *devices, struct mapped_device *md)
 162 {
 163         struct list_head *tmp, *next;
 164
 165         list_for_each_safe(tmp, next, devices) {
 166                 struct dm_dev_internal *dd =
 167                     list_entry(tmp, struct dm_dev_internal, list);
 168                 DMWARN("%s: dm_table_destroy: dm_put_device call missing for %s",
 169                        dm_device_name(md), dd->dm_dev->name);
 170                 dm_put_table_device(md, dd->dm_dev);
 171                 kfree(dd);
 172         }
 173 }
 174
 175 static void dm_table_destroy_crypto_profile(struct dm_table *t);
 176
 177 void dm_table_destroy(struct dm_table *t)
 178 {
 179         if (!t)
 180                 return;
 181
 182         /* free the indexes */
 183         if (t->depth >= 2)
 184                 kvfree(t->index[t->depth - 2]);
 185
 186         /* free the targets */
 187         for (unsigned int i = 0; i < t->num_targets; i++) {
 188                 struct dm_target *ti = dm_table_get_target(t, i);
 189
 190                 if (ti->type->dtr)
 191                         ti->type->dtr(ti);
 192
 193                 dm_put_target_type(ti->type);
 194         }
 195
 196         kvfree(t->highs);
 197
 198         /* free the device list */
 199         free_devices(&t->devices, t->md);
 200
 201         dm_free_md_mempools(t->mempools);
 202
 203         dm_table_destroy_crypto_profile(t);
 204
 205         kfree(t);
 206 }
 207
 208 /*
 209  * See if we've already got a device in the list.
 210  */
 211 static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
 212 {
 213         struct dm_dev_internal *dd;
 214
 215         list_for_each_entry(dd, l, list)
 216                 if (dd->dm_dev->bdev->bd_dev == dev)
 217                         return dd;
 218
 219         return NULL;
 220 }
 221
 222 /*
 223  * If possible, this checks an area of a destination device is invalid.
 224  */
 225 static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
 226                                   sector_t start, sector_t len, void *data)
 227 {
 228         struct queue_limits *limits = data;
 229         struct block_device *bdev = dev->bdev;
 230         sector_t dev_size = bdev_nr_sectors(bdev);
 231         unsigned short logical_block_size_sectors =
 232                 limits->logical_block_size >> SECTOR_SHIFT;
 233
 234         if (!dev_size)
 235                 return 0;
 236
 237         if ((start >= dev_size) || (start + len > dev_size)) {
 238                 DMERR("%s: %pg too small for target: start=%llu, len=%llu, dev_size=%llu",
 239                       dm_device_name(ti->table->md), bdev,
 240                       (unsigned long long)start,
 241                       (unsigned long long)len,
 242                       (unsigned long long)dev_size);
 243                 return 1;
 244         }
 245
 246         /*
 247          * If the target is mapped to zoned block device(s), check
 248          * that the zones are not partially mapped.
 249          */
 250         if (bdev_is_zoned(bdev)) {
 251                 unsigned int zone_sectors = bdev_zone_sectors(bdev);
 252
 253                 if (start & (zone_sectors - 1)) {
 254                         DMERR("%s: start=%llu not aligned to h/w zone size %u of %pg",
 255                               dm_device_name(ti->table->md),
 256                               (unsigned long long)start,
 257                               zone_sectors, bdev);
 258                         return 1;
 259                 }
 260
 261                 /*
 262                  * Note: The last zone of a zoned block device may be smaller
 263                  * than other zones. So for a target mapping the end of a
 264                  * zoned block device with such a zone, len would not be zone
 265                  * aligned. We do not allow such last smaller zone to be part
 266                  * of the mapping here to ensure that mappings with multiple
 267                  * devices do not end up with a smaller zone in the middle of
 268                  * the sector range.
 269                  */
 270                 if (len & (zone_sectors - 1)) {
 271                         DMERR("%s: len=%llu not aligned to h/w zone size %u of %pg",
 272                               dm_device_name(ti->table->md),
 273                               (unsigned long long)len,
 274                               zone_sectors, bdev);
 275                         return 1;
 276                 }
 277         }
 278
 279         if (logical_block_size_sectors <= 1)
 280                 return 0;
 281
 282         if (start & (logical_block_size_sectors - 1)) {
 283                 DMERR("%s: start=%llu not aligned to h/w logical block size %u of %pg",
 284                       dm_device_name(ti->table->md),
 285                       (unsigned long long)start,
 286                       limits->logical_block_size, bdev);
 287                 return 1;
 288         }
 289
 290         if (len & (logical_block_size_sectors - 1)) {
 291                 DMERR("%s: len=%llu not aligned to h/w logical block size %u of %pg",
 292                       dm_device_name(ti->table->md),
 293                       (unsigned long long)len,
 294                       limits->logical_block_size, bdev);
 295                 return 1;
 296         }
 297
 298         return 0;
 299 }
 300
 301 /*
 302  * This upgrades the mode on an already open dm_dev, being
 303  * careful to leave things as they were if we fail to reopen the
 304  * device and not to touch the existing bdev field in case
 305  * it is accessed concurrently.
 306  */
 307 static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
 308                         struct mapped_device *md)
 309 {
 310         int r;
 311         struct dm_dev *old_dev, *new_dev;
 312
 313         old_dev = dd->dm_dev;
 314
 315         r = dm_get_table_device(md, dd->dm_dev->bdev->bd_dev,
 316                                 dd->dm_dev->mode | new_mode, &new_dev);
 317         if (r)
 318                 return r;
 319
 320         dd->dm_dev = new_dev;
 321         dm_put_table_device(md, old_dev);
 322
 323         return 0;
 324 }
 325
 326 /*
 327  * Convert the path to a device
 328  */
 329 dev_t dm_get_dev_t(const char *path)
 330 {
 331         dev_t dev;
 332
 333         if (lookup_bdev(path, &dev))
 334                 dev = name_to_dev_t(path);
 335         return dev;
 336 }
 337 EXPORT_SYMBOL_GPL(dm_get_dev_t);
 338
 339 /*
 340  * Add a device to the list, or just increment the usage count if
 341  * it's already present.
 342  */
 343 int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
 344                   struct dm_dev **result)
 345 {
 346         int r;
 347         dev_t dev;
 348         unsigned int major, minor;
 349         char dummy;
 350         struct dm_dev_internal *dd;
 351         struct dm_table *t = ti->table;
 352
 353         BUG_ON(!t);
 354
 355         if (sscanf(path, "%u:%u%c", &major, &minor, &dummy) == 2) {
 356                 /* Extract the major/minor numbers */
 357                 dev = MKDEV(major, minor);
 358                 if (MAJOR(dev) != major || MINOR(dev) != minor)
 359                         return -EOVERFLOW;
 360         } else {
 361                 dev = dm_get_dev_t(path);
 362                 if (!dev)
 363                         return -ENODEV;
 364         }
 365         if (dev == disk_devt(t->md->disk))
 366                 return -EINVAL;
 367
 368         dd = find_device(&t->devices, dev);
 369         if (!dd) {
 370                 dd = kmalloc(sizeof(*dd), GFP_KERNEL);
 371                 if (!dd)
 372                         return -ENOMEM;
 373
 374                 r = dm_get_table_device(t->md, dev, mode, &dd->dm_dev);
 375                 if (r) {
 376                         kfree(dd);
 377                         return r;
 378                 }
 379
 380                 refcount_set(&dd->count, 1);
 381                 list_add(&dd->list, &t->devices);
 382                 goto out;
 383
 384         } else if (dd->dm_dev->mode != (mode | dd->dm_dev->mode)) {
 385                 r = upgrade_mode(dd, mode, t->md);
 386                 if (r)
 387                         return r;
 388         }
 389         refcount_inc(&dd->count);
 390 out:
 391         *result = dd->dm_dev;
 392         return 0;
 393 }
 394 EXPORT_SYMBOL(dm_get_device);
 395
 396 static int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
 397                                 sector_t start, sector_t len, void *data)
 398 {
 399         struct queue_limits *limits = data;
 400         struct block_device *bdev = dev->bdev;
 401         struct request_queue *q = bdev_get_queue(bdev);
 402
 403         if (unlikely(!q)) {
 404                 DMWARN("%s: Cannot set limits for nonexistent device %pg",
 405                        dm_device_name(ti->table->md), bdev);
 406                 return 0;
 407         }
 408
 409         if (blk_stack_limits(limits, &q->limits,
 410                         get_start_sect(bdev) + start) < 0)
 411                 DMWARN("%s: adding target device %pg caused an alignment inconsistency: "
 412                        "physical_block_size=%u, logical_block_size=%u, "
 413                        "alignment_offset=%u, start=%llu",
 414                        dm_device_name(ti->table->md), bdev,
 415                        q->limits.physical_block_size,
 416                        q->limits.logical_block_size,
 417                        q->limits.alignment_offset,
 418                        (unsigned long long) start << SECTOR_SHIFT);
 419         return 0;
 420 }
 421
 422 /*
 423  * Decrement a device's use count and remove it if necessary.
 424  */
 425 void dm_put_device(struct dm_target *ti, struct dm_dev *d)
 426 {
 427         int found = 0;
 428         struct list_head *devices = &ti->table->devices;
 429         struct dm_dev_internal *dd;
 430
 431         list_for_each_entry(dd, devices, list) {
 432                 if (dd->dm_dev == d) {
 433                         found = 1;
 434                         break;
 435                 }
 436         }
 437         if (!found) {
 438                 DMERR("%s: device %s not in table devices list",
 439                       dm_device_name(ti->table->md), d->name);
 440                 return;
 441         }
 442         if (refcount_dec_and_test(&dd->count)) {
 443                 dm_put_table_device(ti->table->md, d);
 444                 list_del(&dd->list);
 445                 kfree(dd);
 446         }
 447 }
 448 EXPORT_SYMBOL(dm_put_device);
 449
 450 /*
 451  * Checks to see if the target joins onto the end of the table.
 452  */
 453 static int adjoin(struct dm_table *t, struct dm_target *ti)
 454 {
 455         struct dm_target *prev;
 456
 457         if (!t->num_targets)
 458                 return !ti->begin;
 459
 460         prev = &t->targets[t->num_targets - 1];
 461         return (ti->begin == (prev->begin + prev->len));
 462 }
 463
 464 /*
 465  * Used to dynamically allocate the arg array.
 466  *
 467  * We do first allocation with GFP_NOIO because dm-mpath and dm-thin must
 468  * process messages even if some device is suspended. These messages have a
 469  * small fixed number of arguments.
 470  *
 471  * On the other hand, dm-switch needs to process bulk data using messages and
 472  * excessive use of GFP_NOIO could cause trouble.
 473  */
 474 static char **realloc_argv(unsigned int *size, char **old_argv)
 475 {
 476         char **argv;
 477         unsigned int new_size;
 478         gfp_t gfp;
 479
 480         if (*size) {
 481                 new_size = *size * 2;
 482                 gfp = GFP_KERNEL;
 483         } else {
 484                 new_size = 8;
 485                 gfp = GFP_NOIO;
 486         }
 487         argv = kmalloc_array(new_size, sizeof(*argv), gfp);
 488         if (argv && old_argv) {
 489                 memcpy(argv, old_argv, *size * sizeof(*argv));
 490                 *size = new_size;
 491         }
 492
 493         kfree(old_argv);
 494         return argv;
 495 }
 496
 497 /*
 498  * Destructively splits up the argument list to pass to ctr.
 499  */
 500 int dm_split_args(int *argc, char ***argvp, char *input)
 501 {
 502         char *start, *end = input, *out, **argv = NULL;
 503         unsigned int array_size = 0;
 504
 505         *argc = 0;
 506
 507         if (!input) {
 508                 *argvp = NULL;
 509                 return 0;
 510         }
 511
 512         argv = realloc_argv(&array_size, argv);
 513         if (!argv)
 514                 return -ENOMEM;
 515
 516         while (1) {
 517                 /* Skip whitespace */
 518                 start = skip_spaces(end);
 519
 520                 if (!*start)
 521                         break;  /* success, we hit the end */
 522
 523                 /* 'out' is used to remove any back-quotes */
 524                 end = out = start;
 525                 while (*end) {
 526                         /* Everything apart from '\0' can be quoted */
 527                         if (*end == '\\' && *(end + 1)) {
 528                                 *out++ = *(end + 1);
 529                                 end += 2;
 530                                 continue;
 531                         }
 532
 533                         if (isspace(*end))
 534                                 break;  /* end of token */
 535
 536                         *out++ = *end++;
 537                 }
 538
 539                 /* have we already filled the array ? */
 540                 if ((*argc + 1) > array_size) {
 541                         argv = realloc_argv(&array_size, argv);
 542                         if (!argv)
 543                                 return -ENOMEM;
 544                 }
 545
 546                 /* we know this is whitespace */
 547                 if (*end)
 548                         end++;
 549
 550                 /* terminate the string and put it in the array */
 551                 *out = '\0';
 552                 argv[*argc] = start;
 553                 (*argc)++;
 554         }
 555
 556         *argvp = argv;
 557         return 0;
 558 }
 559
 560 /*
 561  * Impose necessary and sufficient conditions on a devices's table such
 562  * that any incoming bio which respects its logical_block_size can be
 563  * processed successfully.  If it falls across the boundary between
 564  * two or more targets, the size of each piece it gets split into must
 565  * be compatible with the logical_block_size of the target processing it.
 566  */
 567 static int validate_hardware_logical_block_alignment(struct dm_table *t,
 568                                                      struct queue_limits *limits)
 569 {
 570         /*
 571          * This function uses arithmetic modulo the logical_block_size
 572          * (in units of 512-byte sectors).
 573          */
 574         unsigned short device_logical_block_size_sects =
 575                 limits->logical_block_size >> SECTOR_SHIFT;
 576
 577         /*
 578          * Offset of the start of the next table entry, mod logical_block_size.
 579          */
 580         unsigned short next_target_start = 0;
 581
 582         /*
 583          * Given an aligned bio that extends beyond the end of a
 584          * target, how many sectors must the next target handle?
 585          */
 586         unsigned short remaining = 0;
 587
 588         struct dm_target *ti;
 589         struct queue_limits ti_limits;
 590         unsigned int i;
 591
 592         /*
 593          * Check each entry in the table in turn.
 594          */
 595         for (i = 0; i < t->num_targets; i++) {
 596                 ti = dm_table_get_target(t, i);
 597
 598                 blk_set_stacking_limits(&ti_limits);
 599
 600                 /* combine all target devices' limits */
 601                 if (ti->type->iterate_devices)
 602                         ti->type->iterate_devices(ti, dm_set_device_limits,
 603                                                   &ti_limits);
 604
 605                 /*
 606                  * If the remaining sectors fall entirely within this
 607                  * table entry are they compatible with its logical_block_size?
 608                  */
 609                 if (remaining < ti->len &&
 610                     remaining & ((ti_limits.logical_block_size >>
 611                                   SECTOR_SHIFT) - 1))
 612                         break;  /* Error */
 613
 614                 next_target_start =
 615                     (unsigned short) ((next_target_start + ti->len) &
 616                                       (device_logical_block_size_sects - 1));
 617                 remaining = next_target_start ?
 618                     device_logical_block_size_sects - next_target_start : 0;
 619         }
 620
 621         if (remaining) {
 622                 DMERR("%s: table line %u (start sect %llu len %llu) "
 623                       "not aligned to h/w logical block size %u",
 624                       dm_device_name(t->md), i,
 625                       (unsigned long long) ti->begin,
 626                       (unsigned long long) ti->len,
 627                       limits->logical_block_size);
 628                 return -EINVAL;
 629         }
 630
 631         return 0;
 632 }
 633
 634 int dm_table_add_target(struct dm_table *t, const char *type,
 635                         sector_t start, sector_t len, char *params)
 636 {
 637         int r = -EINVAL, argc;
 638         char **argv;
 639         struct dm_target *ti;
 640
 641         if (t->singleton) {
 642                 DMERR("%s: target type %s must appear alone in table",
 643                       dm_device_name(t->md), t->targets->type->name);
 644                 return -EINVAL;
 645         }
 646
 647         BUG_ON(t->num_targets >= t->num_allocated);
 648
 649         ti = t->targets + t->num_targets;
 650         memset(ti, 0, sizeof(*ti));
 651
 652         if (!len) {
 653                 DMERR("%s: zero-length target", dm_device_name(t->md));
 654                 return -EINVAL;
 655         }
 656
 657         ti->type = dm_get_target_type(type);
 658         if (!ti->type) {
 659                 DMERR("%s: %s: unknown target type", dm_device_name(t->md), type);
 660                 return -EINVAL;
 661         }
 662
 663         if (dm_target_needs_singleton(ti->type)) {
 664                 if (t->num_targets) {
 665                         ti->error = "singleton target type must appear alone in table";
 666                         goto bad;
 667                 }
 668                 t->singleton = true;
 669         }
 670
 671         if (dm_target_always_writeable(ti->type) && !(t->mode & FMODE_WRITE)) {
 672                 ti->error = "target type may not be included in a read-only table";
 673                 goto bad;
 674         }
 675
 676         if (t->immutable_target_type) {
 677                 if (t->immutable_target_type != ti->type) {
 678                         ti->error = "immutable target type cannot be mixed with other target types";
 679                         goto bad;
 680                 }
 681         } else if (dm_target_is_immutable(ti->type)) {
 682                 if (t->num_targets) {
 683                         ti->error = "immutable target type cannot be mixed with other target types";
 684                         goto bad;
 685                 }
 686                 t->immutable_target_type = ti->type;
 687         }
 688
 689         if (dm_target_has_integrity(ti->type))
 690                 t->integrity_added = 1;
 691
 692         ti->table = t;
 693         ti->begin = start;
 694         ti->len = len;
 695         ti->error = "Unknown error";
 696
 697         /*
 698          * Does this target adjoin the previous one ?
 699          */
 700         if (!adjoin(t, ti)) {
 701                 ti->error = "Gap in table";
 702                 goto bad;
 703         }
 704
 705         r = dm_split_args(&argc, &argv, params);
 706         if (r) {
 707                 ti->error = "couldn't split parameters";
 708                 goto bad;
 709         }
 710
 711         r = ti->type->ctr(ti, argc, argv);
 712         kfree(argv);
 713         if (r)
 714                 goto bad;
 715
 716         t->highs[t->num_targets++] = ti->begin + ti->len - 1;
 717
 718         if (!ti->num_discard_bios && ti->discards_supported)
 719                 DMWARN("%s: %s: ignoring discards_supported because num_discard_bios is zero.",
 720                        dm_device_name(t->md), type);
 721
 722         if (ti->limit_swap_bios && !static_key_enabled(&swap_bios_enabled.key))
 723                 static_branch_enable(&swap_bios_enabled);
 724
 725         return 0;
 726
 727  bad:
 728         DMERR("%s: %s: %s (%pe)", dm_device_name(t->md), type, ti->error, ERR_PTR(r));
 729         dm_put_target_type(ti->type);
 730         return r;
 731 }
 732
 733 /*
 734  * Target argument parsing helpers.
 735  */
 736 static int validate_next_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
 737                              unsigned int *value, char **error, unsigned int grouped)
 738 {
 739         const char *arg_str = dm_shift_arg(arg_set);
 740         char dummy;
 741
 742         if (!arg_str ||
 743             (sscanf(arg_str, "%u%c", value, &dummy) != 1) ||
 744             (*value < arg->min) ||
 745             (*value > arg->max) ||
 746             (grouped && arg_set->argc < *value)) {
 747                 *error = arg->error;
 748                 return -EINVAL;
 749         }
 750
 751         return 0;
 752 }
 753
 754 int dm_read_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
 755                 unsigned int *value, char **error)
 756 {
 757         return validate_next_arg(arg, arg_set, value, error, 0);
 758 }
 759 EXPORT_SYMBOL(dm_read_arg);
 760
 761 int dm_read_arg_group(const struct dm_arg *arg, struct dm_arg_set *arg_set,
 762                       unsigned int *value, char **error)
 763 {
 764         return validate_next_arg(arg, arg_set, value, error, 1);
 765 }
 766 EXPORT_SYMBOL(dm_read_arg_group);
 767
 768 const char *dm_shift_arg(struct dm_arg_set *as)
 769 {
 770         char *r;
 771
 772         if (as->argc) {
 773                 as->argc--;
 774                 r = *as->argv;
 775                 as->argv++;
 776                 return r;
 777         }
 778
 779         return NULL;
 780 }
 781 EXPORT_SYMBOL(dm_shift_arg);
 782
 783 void dm_consume_args(struct dm_arg_set *as, unsigned int num_args)
 784 {
 785         BUG_ON(as->argc < num_args);
 786         as->argc -= num_args;
 787         as->argv += num_args;
 788 }
 789 EXPORT_SYMBOL(dm_consume_args);
 790
 791 static bool __table_type_bio_based(enum dm_queue_mode table_type)
 792 {
 793         return (table_type == DM_TYPE_BIO_BASED ||
 794                 table_type == DM_TYPE_DAX_BIO_BASED);
 795 }
 796
 797 static bool __table_type_request_based(enum dm_queue_mode table_type)
 798 {
 799         return table_type == DM_TYPE_REQUEST_BASED;
 800 }
 801
 802 void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type)
 803 {
 804         t->type = type;
 805 }
 806 EXPORT_SYMBOL_GPL(dm_table_set_type);
 807
 808 /* validate the dax capability of the target device span */
 809 static int device_not_dax_capable(struct dm_target *ti, struct dm_dev *dev,
 810                         sector_t start, sector_t len, void *data)
 811 {
 812         if (dev->dax_dev)
 813                 return false;
 814
 815         DMDEBUG("%pg: error: dax unsupported by block device", dev->bdev);
 816         return true;
 817 }
 818
 819 /* Check devices support synchronous DAX */
 820 static int device_not_dax_synchronous_capable(struct dm_target *ti, struct dm_dev *dev,
 821                                               sector_t start, sector_t len, void *data)
 822 {
 823         return !dev->dax_dev || !dax_synchronous(dev->dax_dev);
 824 }
 825
 826 static bool dm_table_supports_dax(struct dm_table *t,
 827                                   iterate_devices_callout_fn iterate_fn)
 828 {
 829         /* Ensure that all targets support DAX. */
 830         for (unsigned int i = 0; i < t->num_targets; i++) {
 831                 struct dm_target *ti = dm_table_get_target(t, i);
 832
 833                 if (!ti->type->direct_access)
 834                         return false;
 835
 836                 if (!ti->type->iterate_devices ||
 837                     ti->type->iterate_devices(ti, iterate_fn, NULL))
 838                         return false;
 839         }
 840
 841         return true;
 842 }
 843
 844 static int device_is_rq_stackable(struct dm_target *ti, struct dm_dev *dev,
 845                                   sector_t start, sector_t len, void *data)
 846 {
 847         struct block_device *bdev = dev->bdev;
 848         struct request_queue *q = bdev_get_queue(bdev);
 849
 850         /* request-based cannot stack on partitions! */
 851         if (bdev_is_partition(bdev))
 852                 return false;
 853
 854         return queue_is_mq(q);
 855 }
 856
 857 static int dm_table_determine_type(struct dm_table *t)
 858 {
 859         unsigned int bio_based = 0, request_based = 0, hybrid = 0;
 860         struct dm_target *ti;
 861         struct list_head *devices = dm_table_get_devices(t);
 862         enum dm_queue_mode live_md_type = dm_get_md_type(t->md);
 863
 864         if (t->type != DM_TYPE_NONE) {
 865                 /* target already set the table's type */
 866                 if (t->type == DM_TYPE_BIO_BASED) {
 867                         /* possibly upgrade to a variant of bio-based */
 868                         goto verify_bio_based;
 869                 }
 870                 BUG_ON(t->type == DM_TYPE_DAX_BIO_BASED);
 871                 goto verify_rq_based;
 872         }
 873
 874         for (unsigned int i = 0; i < t->num_targets; i++) {
 875                 ti = dm_table_get_target(t, i);
 876                 if (dm_target_hybrid(ti))
 877                         hybrid = 1;
 878                 else if (dm_target_request_based(ti))
 879                         request_based = 1;
 880                 else
 881                         bio_based = 1;
 882
 883                 if (bio_based && request_based) {
 884                         DMERR("Inconsistent table: different target types can't be mixed up");
 885                         return -EINVAL;
 886                 }
 887         }
 888
 889         if (hybrid && !bio_based && !request_based) {
 890                 /*
 891                  * The targets can work either way.
 892                  * Determine the type from the live device.
 893                  * Default to bio-based if device is new.
 894                  */
 895                 if (__table_type_request_based(live_md_type))
 896                         request_based = 1;
 897                 else
 898                         bio_based = 1;
 899         }
 900
 901         if (bio_based) {
 902 verify_bio_based:
 903                 /* We must use this table as bio-based */
 904                 t->type = DM_TYPE_BIO_BASED;
 905                 if (dm_table_supports_dax(t, device_not_dax_capable) ||
 906                     (list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED)) {
 907                         t->type = DM_TYPE_DAX_BIO_BASED;
 908                 }
 909                 return 0;
 910         }
 911
 912         BUG_ON(!request_based); /* No targets in this table */
 913
 914         t->type = DM_TYPE_REQUEST_BASED;
 915
 916 verify_rq_based:
 917         /*
 918          * Request-based dm supports only tables that have a single target now.
 919          * To support multiple targets, request splitting support is needed,
 920          * and that needs lots of changes in the block-layer.
 921          * (e.g. request completion process for partial completion.)
 922          */
 923         if (t->num_targets > 1) {
 924                 DMERR("request-based DM doesn't support multiple targets");
 925                 return -EINVAL;
 926         }
 927
 928         if (list_empty(devices)) {
 929                 int srcu_idx;
 930                 struct dm_table *live_table = dm_get_live_table(t->md, &srcu_idx);
 931
 932                 /* inherit live table's type */
 933                 if (live_table)
 934                         t->type = live_table->type;
 935                 dm_put_live_table(t->md, srcu_idx);
 936                 return 0;
 937         }
 938
 939         ti = dm_table_get_immutable_target(t);
 940         if (!ti) {
 941                 DMERR("table load rejected: immutable target is required");
 942                 return -EINVAL;
 943         } else if (ti->max_io_len) {
 944                 DMERR("table load rejected: immutable target that splits IO is not supported");
 945                 return -EINVAL;
 946         }
 947
 948         /* Non-request-stackable devices can't be used for request-based dm */
 949         if (!ti->type->iterate_devices ||
 950             !ti->type->iterate_devices(ti, device_is_rq_stackable, NULL)) {
 951                 DMERR("table load rejected: including non-request-stackable devices");
 952                 return -EINVAL;
 953         }
 954
 955         return 0;
 956 }
 957
 958 enum dm_queue_mode dm_table_get_type(struct dm_table *t)
 959 {
 960         return t->type;
 961 }
 962
 963 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
 964 {
 965         return t->immutable_target_type;
 966 }
 967
 968 struct dm_target *dm_table_get_immutable_target(struct dm_table *t)
 969 {
 970         /* Immutable target is implicitly a singleton */
 971         if (t->num_targets > 1 ||
 972             !dm_target_is_immutable(t->targets[0].type))
 973                 return NULL;
 974
 975         return t->targets;
 976 }
 977
 978 struct dm_target *dm_table_get_wildcard_target(struct dm_table *t)
 979 {
 980         for (unsigned int i = 0; i < t->num_targets; i++) {
 981                 struct dm_target *ti = dm_table_get_target(t, i);
 982
 983                 if (dm_target_is_wildcard(ti->type))
 984                         return ti;
 985         }
 986
 987         return NULL;
 988 }
 989
 990 bool dm_table_bio_based(struct dm_table *t)
 991 {
 992         return __table_type_bio_based(dm_table_get_type(t));
 993 }
 994
 995 bool dm_table_request_based(struct dm_table *t)
 996 {
 997         return __table_type_request_based(dm_table_get_type(t));
 998 }
 999
1000 static bool dm_table_supports_poll(struct dm_table *t);
1001
1002 static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device *md)
1003 {
1004         enum dm_queue_mode type = dm_table_get_type(t);
1005         unsigned int per_io_data_size = 0, front_pad, io_front_pad;
1006         unsigned int min_pool_size = 0, pool_size;
1007         struct dm_md_mempools *pools;
1008
1009         if (unlikely(type == DM_TYPE_NONE)) {
1010                 DMERR("no table type is set, can't allocate mempools");
1011                 return -EINVAL;
1012         }
1013
1014         pools = kzalloc_node(sizeof(*pools), GFP_KERNEL, md->numa_node_id);
1015         if (!pools)
1016                 return -ENOMEM;
1017
1018         if (type == DM_TYPE_REQUEST_BASED) {
1019                 pool_size = dm_get_reserved_rq_based_ios();
1020                 front_pad = offsetof(struct dm_rq_clone_bio_info, clone);
1021                 goto init_bs;
1022         }
1023
1024         for (unsigned int i = 0; i < t->num_targets; i++) {
1025                 struct dm_target *ti = dm_table_get_target(t, i);
1026
1027                 per_io_data_size = max(per_io_data_size, ti->per_io_data_size);
1028                 min_pool_size = max(min_pool_size, ti->num_flush_bios);
1029         }
1030         pool_size = max(dm_get_reserved_bio_based_ios(), min_pool_size);
1031         front_pad = roundup(per_io_data_size,
1032                 __alignof__(struct dm_target_io)) + DM_TARGET_IO_BIO_OFFSET;
1033
1034         io_front_pad = roundup(per_io_data_size,
1035                 __alignof__(struct dm_io)) + DM_IO_BIO_OFFSET;
1036         if (bioset_init(&pools->io_bs, pool_size, io_front_pad,
1037                         dm_table_supports_poll(t) ? BIOSET_PERCPU_CACHE : 0))
1038                 goto out_free_pools;
1039         if (t->integrity_supported &&
1040             bioset_integrity_create(&pools->io_bs, pool_size))
1041                 goto out_free_pools;
1042 init_bs:
1043         if (bioset_init(&pools->bs, pool_size, front_pad, 0))
1044                 goto out_free_pools;
1045         if (t->integrity_supported &&
1046             bioset_integrity_create(&pools->bs, pool_size))
1047                 goto out_free_pools;
1048
1049         t->mempools = pools;
1050         return 0;
1051
1052 out_free_pools:
1053         dm_free_md_mempools(pools);
1054         return -ENOMEM;
1055 }
1056
1057 static int setup_indexes(struct dm_table *t)
1058 {
1059         int i;
1060         unsigned int total = 0;
1061         sector_t *indexes;
1062
1063         /* allocate the space for *all* the indexes */
1064         for (i = t->depth - 2; i >= 0; i--) {
1065                 t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
1066                 total += t->counts[i];
1067         }
1068
1069         indexes = kvcalloc(total, NODE_SIZE, GFP_KERNEL);
1070         if (!indexes)
1071                 return -ENOMEM;
1072
1073         /* set up internal nodes, bottom-up */
1074         for (i = t->depth - 2; i >= 0; i--) {
1075                 t->index[i] = indexes;
1076                 indexes += (KEYS_PER_NODE * t->counts[i]);
1077                 setup_btree_index(i, t);
1078         }
1079
1080         return 0;
1081 }
1082
1083 /*
1084  * Builds the btree to index the map.
1085  */
1086 static int dm_table_build_index(struct dm_table *t)
1087 {
1088         int r = 0;
1089         unsigned int leaf_nodes;
1090
1091         /* how many indexes will the btree have ? */
1092         leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
1093         t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
1094
1095         /* leaf layer has already been set up */
1096         t->counts[t->depth - 1] = leaf_nodes;
1097         t->index[t->depth - 1] = t->highs;
1098
1099         if (t->depth >= 2)
1100                 r = setup_indexes(t);
1101
1102         return r;
1103 }
1104
1105 static bool integrity_profile_exists(struct gendisk *disk)
1106 {
1107         return !!blk_get_integrity(disk);
1108 }
1109
1110 /*
1111  * Get a disk whose integrity profile reflects the table's profile.
1112  * Returns NULL if integrity support was inconsistent or unavailable.
1113  */
1114 static struct gendisk *dm_table_get_integrity_disk(struct dm_table *t)
1115 {
1116         struct list_head *devices = dm_table_get_devices(t);
1117         struct dm_dev_internal *dd = NULL;
1118         struct gendisk *prev_disk = NULL, *template_disk = NULL;
1119
1120         for (unsigned int i = 0; i < t->num_targets; i++) {
1121                 struct dm_target *ti = dm_table_get_target(t, i);
1122
1123                 if (!dm_target_passes_integrity(ti->type))
1124                         goto no_integrity;
1125         }
1126
1127         list_for_each_entry(dd, devices, list) {
1128                 template_disk = dd->dm_dev->bdev->bd_disk;
1129                 if (!integrity_profile_exists(template_disk))
1130                         goto no_integrity;
1131                 else if (prev_disk &&
1132                          blk_integrity_compare(prev_disk, template_disk) < 0)
1133                         goto no_integrity;
1134                 prev_disk = template_disk;
1135         }
1136
1137         return template_disk;
1138
1139 no_integrity:
1140         if (prev_disk)
1141                 DMWARN("%s: integrity not set: %s and %s profile mismatch",
1142                        dm_device_name(t->md),
1143                        prev_disk->disk_name,
1144                        template_disk->disk_name);
1145         return NULL;
1146 }
1147
1148 /*
1149  * Register the mapped device for blk_integrity support if the
1150  * underlying devices have an integrity profile.  But all devices may
1151  * not have matching profiles (checking all devices isn't reliable
1152  * during table load because this table may use other DM device(s) which
1153  * must be resumed before they will have an initialized integity
1154  * profile).  Consequently, stacked DM devices force a 2 stage integrity
1155  * profile validation: First pass during table load, final pass during
1156  * resume.
1157  */
1158 static int dm_table_register_integrity(struct dm_table *t)
1159 {
1160         struct mapped_device *md = t->md;
1161         struct gendisk *template_disk = NULL;
1162
1163         /* If target handles integrity itself do not register it here. */
1164         if (t->integrity_added)
1165                 return 0;
1166
1167         template_disk = dm_table_get_integrity_disk(t);
1168         if (!template_disk)
1169                 return 0;
1170
1171         if (!integrity_profile_exists(dm_disk(md))) {
1172                 t->integrity_supported = true;
1173                 /*
1174                  * Register integrity profile during table load; we can do
1175                  * this because the final profile must match during resume.
1176                  */
1177                 blk_integrity_register(dm_disk(md),
1178                                        blk_get_integrity(template_disk));
1179                 return 0;
1180         }
1181
1182         /*
1183          * If DM device already has an initialized integrity
1184          * profile the new profile should not conflict.
1185          */
1186         if (blk_integrity_compare(dm_disk(md), template_disk) < 0) {
1187                 DMERR("%s: conflict with existing integrity profile: %s profile mismatch",
1188                       dm_device_name(t->md),
1189                       template_disk->disk_name);
1190                 return 1;
1191         }
1192
1193         /* Preserve existing integrity profile */
1194         t->integrity_supported = true;
1195         return 0;
1196 }
1197
1198 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
1199
1200 struct dm_crypto_profile {
1201         struct blk_crypto_profile profile;
1202         struct mapped_device *md;
1203 };
1204
1205 static int dm_keyslot_evict_callback(struct dm_target *ti, struct dm_dev *dev,
1206                                      sector_t start, sector_t len, void *data)
1207 {
1208         const struct blk_crypto_key *key = data;
1209
1210         blk_crypto_evict_key(dev->bdev, key);
1211         return 0;
1212 }
1213
1214 /*
1215  * When an inline encryption key is evicted from a device-mapper device, evict
1216  * it from all the underlying devices.
1217  */
1218 static int dm_keyslot_evict(struct blk_crypto_profile *profile,
1219                             const struct blk_crypto_key *key, unsigned int slot)
1220 {
1221         struct mapped_device *md =
1222                 container_of(profile, struct dm_crypto_profile, profile)->md;
1223         struct dm_table *t;
1224         int srcu_idx;
1225
1226         t = dm_get_live_table(md, &srcu_idx);
1227         if (!t)
1228                 return 0;
1229
1230         for (unsigned int i = 0; i < t->num_targets; i++) {
1231                 struct dm_target *ti = dm_table_get_target(t, i);
1232
1233                 if (!ti->type->iterate_devices)
1234                         continue;
1235                 ti->type->iterate_devices(ti, dm_keyslot_evict_callback,
1236                                           (void *)key);
1237         }
1238
1239         dm_put_live_table(md, srcu_idx);
1240         return 0;
1241 }
1242
1243 static int
1244 device_intersect_crypto_capabilities(struct dm_target *ti, struct dm_dev *dev,
1245                                      sector_t start, sector_t len, void *data)
1246 {
1247         struct blk_crypto_profile *parent = data;
1248         struct blk_crypto_profile *child =
1249                 bdev_get_queue(dev->bdev)->crypto_profile;
1250
1251         blk_crypto_intersect_capabilities(parent, child);
1252         return 0;
1253 }
1254
1255 void dm_destroy_crypto_profile(struct blk_crypto_profile *profile)
1256 {
1257         struct dm_crypto_profile *dmcp = container_of(profile,
1258                                                       struct dm_crypto_profile,
1259                                                       profile);
1260
1261         if (!profile)
1262                 return;
1263
1264         blk_crypto_profile_destroy(profile);
1265         kfree(dmcp);
1266 }
1267
1268 static void dm_table_destroy_crypto_profile(struct dm_table *t)
1269 {
1270         dm_destroy_crypto_profile(t->crypto_profile);
1271         t->crypto_profile = NULL;
1272 }
1273
1274 /*
1275  * Constructs and initializes t->crypto_profile with a crypto profile that
1276  * represents the common set of crypto capabilities of the devices described by
1277  * the dm_table.  However, if the constructed crypto profile doesn't support all
1278  * crypto capabilities that are supported by the current mapped_device, it
1279  * returns an error instead, since we don't support removing crypto capabilities
1280  * on table changes.  Finally, if the constructed crypto profile is "empty" (has
1281  * no crypto capabilities at all), it just sets t->crypto_profile to NULL.
1282  */
1283 static int dm_table_construct_crypto_profile(struct dm_table *t)
1284 {
1285         struct dm_crypto_profile *dmcp;
1286         struct blk_crypto_profile *profile;
1287         unsigned int i;
1288         bool empty_profile = true;
1289
1290         dmcp = kmalloc(sizeof(*dmcp), GFP_KERNEL);
1291         if (!dmcp)
1292                 return -ENOMEM;
1293         dmcp->md = t->md;
1294
1295         profile = &dmcp->profile;
1296         blk_crypto_profile_init(profile, 0);
1297         profile->ll_ops.keyslot_evict = dm_keyslot_evict;
1298         profile->max_dun_bytes_supported = UINT_MAX;
1299         memset(profile->modes_supported, 0xFF,
1300                sizeof(profile->modes_supported));
1301
1302         for (i = 0; i < t->num_targets; i++) {
1303                 struct dm_target *ti = dm_table_get_target(t, i);
1304
1305                 if (!dm_target_passes_crypto(ti->type)) {
1306                         blk_crypto_intersect_capabilities(profile, NULL);
1307                         break;
1308                 }
1309                 if (!ti->type->iterate_devices)
1310                         continue;
1311                 ti->type->iterate_devices(ti,
1312                                           device_intersect_crypto_capabilities,
1313                                           profile);
1314         }
1315
1316         if (t->md->queue &&
1317             !blk_crypto_has_capabilities(profile,
1318                                          t->md->queue->crypto_profile)) {
1319                 DMERR("Inline encryption capabilities of new DM table were more restrictive than the old table's. This is not supported!");
1320                 dm_destroy_crypto_profile(profile);
1321                 return -EINVAL;
1322         }
1323
1324         /*
1325          * If the new profile doesn't actually support any crypto capabilities,
1326          * we may as well represent it with a NULL profile.
1327          */
1328         for (i = 0; i < ARRAY_SIZE(profile->modes_supported); i++) {
1329                 if (profile->modes_supported[i]) {
1330                         empty_profile = false;
1331                         break;
1332                 }
1333         }
1334
1335         if (empty_profile) {
1336                 dm_destroy_crypto_profile(profile);
1337                 profile = NULL;
1338         }
1339
1340         /*
1341          * t->crypto_profile is only set temporarily while the table is being
1342          * set up, and it gets set to NULL after the profile has been
1343          * transferred to the request_queue.
1344          */
1345         t->crypto_profile = profile;
1346
1347         return 0;
1348 }
1349
1350 static void dm_update_crypto_profile(struct request_queue *q,
1351                                      struct dm_table *t)
1352 {
1353         if (!t->crypto_profile)
1354                 return;
1355
1356         /* Make the crypto profile less restrictive. */
1357         if (!q->crypto_profile) {
1358                 blk_crypto_register(t->crypto_profile, q);
1359         } else {
1360                 blk_crypto_update_capabilities(q->crypto_profile,
1361                                                t->crypto_profile);
1362                 dm_destroy_crypto_profile(t->crypto_profile);
1363         }
1364         t->crypto_profile = NULL;
1365 }
1366
1367 #else /* CONFIG_BLK_INLINE_ENCRYPTION */
1368
1369 static int dm_table_construct_crypto_profile(struct dm_table *t)
1370 {
1371         return 0;
1372 }
1373
1374 void dm_destroy_crypto_profile(struct blk_crypto_profile *profile)
1375 {
1376 }
1377
1378 static void dm_table_destroy_crypto_profile(struct dm_table *t)
1379 {
1380 }
1381
1382 static void dm_update_crypto_profile(struct request_queue *q,
1383                                      struct dm_table *t)
1384 {
1385 }
1386
1387 #endif /* !CONFIG_BLK_INLINE_ENCRYPTION */
1388
1389 /*
1390  * Prepares the table for use by building the indices,
1391  * setting the type, and allocating mempools.
1392  */
1393 int dm_table_complete(struct dm_table *t)
1394 {
1395         int r;
1396
1397         r = dm_table_determine_type(t);
1398         if (r) {
1399                 DMERR("unable to determine table type");
1400                 return r;
1401         }
1402
1403         r = dm_table_build_index(t);
1404         if (r) {
1405                 DMERR("unable to build btrees");
1406                 return r;
1407         }
1408
1409         r = dm_table_register_integrity(t);
1410         if (r) {
1411                 DMERR("could not register integrity profile.");
1412                 return r;
1413         }
1414
1415         r = dm_table_construct_crypto_profile(t);
1416         if (r) {
1417                 DMERR("could not construct crypto profile.");
1418                 return r;
1419         }
1420
1421         r = dm_table_alloc_md_mempools(t, t->md);
1422         if (r)
1423                 DMERR("unable to allocate mempools");
1424
1425         return r;
1426 }
1427
1428 static DEFINE_MUTEX(_event_lock);
1429 void dm_table_event_callback(struct dm_table *t,
1430                              void (*fn)(void *), void *context)
1431 {
1432         mutex_lock(&_event_lock);
1433         t->event_fn = fn;
1434         t->event_context = context;
1435         mutex_unlock(&_event_lock);
1436 }
1437
1438 void dm_table_event(struct dm_table *t)
1439 {
1440         mutex_lock(&_event_lock);
1441         if (t->event_fn)
1442                 t->event_fn(t->event_context);
1443         mutex_unlock(&_event_lock);
1444 }
1445 EXPORT_SYMBOL(dm_table_event);
1446
1447 inline sector_t dm_table_get_size(struct dm_table *t)
1448 {
1449         return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1450 }
1451 EXPORT_SYMBOL(dm_table_get_size);
1452
1453 /*
1454  * Search the btree for the correct target.
1455  *
1456  * Caller should check returned pointer for NULL
1457  * to trap I/O beyond end of device.
1458  */
1459 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1460 {
1461         unsigned int l, n = 0, k = 0;
1462         sector_t *node;
1463
1464         if (unlikely(sector >= dm_table_get_size(t)))
1465                 return NULL;
1466
1467         for (l = 0; l < t->depth; l++) {
1468                 n = get_child(n, k);
1469                 node = get_node(t, l, n);
1470
1471                 for (k = 0; k < KEYS_PER_NODE; k++)
1472                         if (node[k] >= sector)
1473                                 break;
1474         }
1475
1476         return &t->targets[(KEYS_PER_NODE * n) + k];
1477 }
1478
1479 static int device_not_poll_capable(struct dm_target *ti, struct dm_dev *dev,
1480                                    sector_t start, sector_t len, void *data)
1481 {
1482         struct request_queue *q = bdev_get_queue(dev->bdev);
1483
1484         return !test_bit(QUEUE_FLAG_POLL, &q->queue_flags);
1485 }
1486
1487 /*
1488  * type->iterate_devices() should be called when the sanity check needs to
1489  * iterate and check all underlying data devices. iterate_devices() will
1490  * iterate all underlying data devices until it encounters a non-zero return
1491  * code, returned by whether the input iterate_devices_callout_fn, or
1492  * iterate_devices() itself internally.
1493  *
1494  * For some target type (e.g. dm-stripe), one call of iterate_devices() may
1495  * iterate multiple underlying devices internally, in which case a non-zero
1496  * return code returned by iterate_devices_callout_fn will stop the iteration
1497  * in advance.
1498  *
1499  * Cases requiring _any_ underlying device supporting some kind of attribute,
1500  * should use the iteration structure like dm_table_any_dev_attr(), or call
1501  * it directly. @func should handle semantics of positive examples, e.g.
1502  * capable of something.
1503  *
1504  * Cases requiring _all_ underlying devices supporting some kind of attribute,
1505  * should use the iteration structure like dm_table_supports_nowait() or
1506  * dm_table_supports_discards(). Or introduce dm_table_all_devs_attr() that
1507  * uses an @anti_func that handle semantics of counter examples, e.g. not
1508  * capable of something. So: return !dm_table_any_dev_attr(t, anti_func, data);
1509  */
1510 static bool dm_table_any_dev_attr(struct dm_table *t,
1511                                   iterate_devices_callout_fn func, void *data)
1512 {
1513         for (unsigned int i = 0; i < t->num_targets; i++) {
1514                 struct dm_target *ti = dm_table_get_target(t, i);
1515
1516                 if (ti->type->iterate_devices &&
1517                     ti->type->iterate_devices(ti, func, data))
1518                         return true;
1519         }
1520
1521         return false;
1522 }
1523
1524 static int count_device(struct dm_target *ti, struct dm_dev *dev,
1525                         sector_t start, sector_t len, void *data)
1526 {
1527         unsigned int *num_devices = data;
1528
1529         (*num_devices)++;
1530
1531         return 0;
1532 }
1533
1534 static bool dm_table_supports_poll(struct dm_table *t)
1535 {
1536         for (unsigned int i = 0; i < t->num_targets; i++) {
1537                 struct dm_target *ti = dm_table_get_target(t, i);
1538
1539                 if (!ti->type->iterate_devices ||
1540                     ti->type->iterate_devices(ti, device_not_poll_capable, NULL))
1541                         return false;
1542         }
1543
1544         return true;
1545 }
1546
1547 /*
1548  * Check whether a table has no data devices attached using each
1549  * target's iterate_devices method.
1550  * Returns false if the result is unknown because a target doesn't
1551  * support iterate_devices.
1552  */
1553 bool dm_table_has_no_data_devices(struct dm_table *t)
1554 {
1555         for (unsigned int i = 0; i < t->num_targets; i++) {
1556                 struct dm_target *ti = dm_table_get_target(t, i);
1557                 unsigned int num_devices = 0;
1558
1559                 if (!ti->type->iterate_devices)
1560                         return false;
1561
1562                 ti->type->iterate_devices(ti, count_device, &num_devices);
1563                 if (num_devices)
1564                         return false;
1565         }
1566
1567         return true;
1568 }
1569
1570 static int device_not_zoned_model(struct dm_target *ti, struct dm_dev *dev,
1571                                   sector_t start, sector_t len, void *data)
1572 {
1573         struct request_queue *q = bdev_get_queue(dev->bdev);
1574         enum blk_zoned_model *zoned_model = data;
1575
1576         return blk_queue_zoned_model(q) != *zoned_model;
1577 }
1578
1579 /*
1580  * Check the device zoned model based on the target feature flag. If the target
1581  * has the DM_TARGET_ZONED_HM feature flag set, host-managed zoned devices are
1582  * also accepted but all devices must have the same zoned model. If the target
1583  * has the DM_TARGET_MIXED_ZONED_MODEL feature set, the devices can have any
1584  * zoned model with all zoned devices having the same zone size.
1585  */
1586 static bool dm_table_supports_zoned_model(struct dm_table *t,
1587                                           enum blk_zoned_model zoned_model)
1588 {
1589         for (unsigned int i = 0; i < t->num_targets; i++) {
1590                 struct dm_target *ti = dm_table_get_target(t, i);
1591
1592                 if (dm_target_supports_zoned_hm(ti->type)) {
1593                         if (!ti->type->iterate_devices ||
1594                             ti->type->iterate_devices(ti, device_not_zoned_model,
1595                                                       &zoned_model))
1596                                 return false;
1597                 } else if (!dm_target_supports_mixed_zoned_model(ti->type)) {
1598                         if (zoned_model == BLK_ZONED_HM)
1599                                 return false;
1600                 }
1601         }
1602
1603         return true;
1604 }
1605
1606 static int device_not_matches_zone_sectors(struct dm_target *ti, struct dm_dev *dev,
1607                                            sector_t start, sector_t len, void *data)
1608 {
1609         unsigned int *zone_sectors = data;
1610
1611         if (!bdev_is_zoned(dev->bdev))
1612                 return 0;
1613         return bdev_zone_sectors(dev->bdev) != *zone_sectors;
1614 }
1615
1616 /*
1617  * Check consistency of zoned model and zone sectors across all targets. For
1618  * zone sectors, if the destination device is a zoned block device, it shall
1619  * have the specified zone_sectors.
1620  */
1621 static int validate_hardware_zoned_model(struct dm_table *t,
1622                                          enum blk_zoned_model zoned_model,
1623                                          unsigned int zone_sectors)
1624 {
1625         if (zoned_model == BLK_ZONED_NONE)
1626                 return 0;
1627
1628         if (!dm_table_supports_zoned_model(t, zoned_model)) {
1629                 DMERR("%s: zoned model is not consistent across all devices",
1630                       dm_device_name(t->md));
1631                 return -EINVAL;
1632         }
1633
1634         /* Check zone size validity and compatibility */
1635         if (!zone_sectors || !is_power_of_2(zone_sectors))
1636                 return -EINVAL;
1637
1638         if (dm_table_any_dev_attr(t, device_not_matches_zone_sectors, &zone_sectors)) {
1639                 DMERR("%s: zone sectors is not consistent across all zoned devices",
1640                       dm_device_name(t->md));
1641                 return -EINVAL;
1642         }
1643
1644         return 0;
1645 }
1646
1647 /*
1648  * Establish the new table's queue_limits and validate them.
1649  */
1650 int dm_calculate_queue_limits(struct dm_table *t,
1651                               struct queue_limits *limits)
1652 {
1653         struct queue_limits ti_limits;
1654         enum blk_zoned_model zoned_model = BLK_ZONED_NONE;
1655         unsigned int zone_sectors = 0;
1656
1657         blk_set_stacking_limits(limits);
1658
1659         for (unsigned int i = 0; i < t->num_targets; i++) {
1660                 struct dm_target *ti = dm_table_get_target(t, i);
1661
1662                 blk_set_stacking_limits(&ti_limits);
1663
1664                 if (!ti->type->iterate_devices) {
1665                         /* Set I/O hints portion of queue limits */
1666                         if (ti->type->io_hints)
1667                                 ti->type->io_hints(ti, &ti_limits);
1668                         goto combine_limits;
1669                 }
1670
1671                 /*
1672                  * Combine queue limits of all the devices this target uses.
1673                  */
1674                 ti->type->iterate_devices(ti, dm_set_device_limits,
1675                                           &ti_limits);
1676
1677                 if (zoned_model == BLK_ZONED_NONE && ti_limits.zoned != BLK_ZONED_NONE) {
1678                         /*
1679                          * After stacking all limits, validate all devices
1680                          * in table support this zoned model and zone sectors.
1681                          */
1682                         zoned_model = ti_limits.zoned;
1683                         zone_sectors = ti_limits.chunk_sectors;
1684                 }
1685
1686                 /* Set I/O hints portion of queue limits */
1687                 if (ti->type->io_hints)
1688                         ti->type->io_hints(ti, &ti_limits);
1689
1690                 /*
1691                  * Check each device area is consistent with the target's
1692                  * overall queue limits.
1693                  */
1694                 if (ti->type->iterate_devices(ti, device_area_is_invalid,
1695                                               &ti_limits))
1696                         return -EINVAL;
1697
1698 combine_limits:
1699                 /*
1700                  * Merge this target's queue limits into the overall limits
1701                  * for the table.
1702                  */
1703                 if (blk_stack_limits(limits, &ti_limits, 0) < 0)
1704                         DMWARN("%s: adding target device (start sect %llu len %llu) "
1705                                "caused an alignment inconsistency",
1706                                dm_device_name(t->md),
1707                                (unsigned long long) ti->begin,
1708                                (unsigned long long) ti->len);
1709         }
1710
1711         /*
1712          * Verify that the zoned model and zone sectors, as determined before
1713          * any .io_hints override, are the same across all devices in the table.
1714          * - this is especially relevant if .io_hints is emulating a disk-managed
1715          *   zoned model (aka BLK_ZONED_NONE) on host-managed zoned block devices.
1716          * BUT...
1717          */
1718         if (limits->zoned != BLK_ZONED_NONE) {
1719                 /*
1720                  * ...IF the above limits stacking determined a zoned model
1721                  * validate that all of the table's devices conform to it.
1722                  */
1723                 zoned_model = limits->zoned;
1724                 zone_sectors = limits->chunk_sectors;
1725         }
1726         if (validate_hardware_zoned_model(t, zoned_model, zone_sectors))
1727                 return -EINVAL;
1728
1729         return validate_hardware_logical_block_alignment(t, limits);
1730 }
1731
1732 /*
1733  * Verify that all devices have an integrity profile that matches the
1734  * DM device's registered integrity profile.  If the profiles don't
1735  * match then unregister the DM device's integrity profile.
1736  */
1737 static void dm_table_verify_integrity(struct dm_table *t)
1738 {
1739         struct gendisk *template_disk = NULL;
1740
1741         if (t->integrity_added)
1742                 return;
1743
1744         if (t->integrity_supported) {
1745                 /*
1746                  * Verify that the original integrity profile
1747                  * matches all the devices in this table.
1748                  */
1749                 template_disk = dm_table_get_integrity_disk(t);
1750                 if (template_disk &&
1751                     blk_integrity_compare(dm_disk(t->md), template_disk) >= 0)
1752                         return;
1753         }
1754
1755         if (integrity_profile_exists(dm_disk(t->md))) {
1756                 DMWARN("%s: unable to establish an integrity profile",
1757                        dm_device_name(t->md));
1758                 blk_integrity_unregister(dm_disk(t->md));
1759         }
1760 }
1761
1762 static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
1763                                 sector_t start, sector_t len, void *data)
1764 {
1765         unsigned long flush = (unsigned long) data;
1766         struct request_queue *q = bdev_get_queue(dev->bdev);
1767
1768         return (q->queue_flags & flush);
1769 }
1770
1771 static bool dm_table_supports_flush(struct dm_table *t, unsigned long flush)
1772 {
1773         /*
1774          * Require at least one underlying device to support flushes.
1775          * t->devices includes internal dm devices such as mirror logs
1776          * so we need to use iterate_devices here, which targets
1777          * supporting flushes must provide.
1778          */
1779         for (unsigned int i = 0; i < t->num_targets; i++) {
1780                 struct dm_target *ti = dm_table_get_target(t, i);
1781
1782                 if (!ti->num_flush_bios)
1783                         continue;
1784
1785                 if (ti->flush_supported)
1786                         return true;
1787
1788                 if (ti->type->iterate_devices &&
1789                     ti->type->iterate_devices(ti, device_flush_capable, (void *) flush))
1790                         return true;
1791         }
1792
1793         return false;
1794 }
1795
1796 static int device_dax_write_cache_enabled(struct dm_target *ti,
1797                                           struct dm_dev *dev, sector_t start,
1798                                           sector_t len, void *data)
1799 {
1800         struct dax_device *dax_dev = dev->dax_dev;
1801
1802         if (!dax_dev)
1803                 return false;
1804
1805         if (dax_write_cache_enabled(dax_dev))
1806                 return true;
1807         return false;
1808 }
1809
1810 static int device_is_rotational(struct dm_target *ti, struct dm_dev *dev,
1811                                 sector_t start, sector_t len, void *data)
1812 {
1813         return !bdev_nonrot(dev->bdev);
1814 }
1815
1816 static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
1817                              sector_t start, sector_t len, void *data)
1818 {
1819         struct request_queue *q = bdev_get_queue(dev->bdev);
1820
1821         return !blk_queue_add_random(q);
1822 }
1823
1824 static int device_not_write_zeroes_capable(struct dm_target *ti, struct dm_dev *dev,
1825                                            sector_t start, sector_t len, void *data)
1826 {
1827         struct request_queue *q = bdev_get_queue(dev->bdev);
1828
1829         return !q->limits.max_write_zeroes_sectors;
1830 }
1831
1832 static bool dm_table_supports_write_zeroes(struct dm_table *t)
1833 {
1834         for (unsigned int i = 0; i < t->num_targets; i++) {
1835                 struct dm_target *ti = dm_table_get_target(t, i);
1836
1837                 if (!ti->num_write_zeroes_bios)
1838                         return false;
1839
1840                 if (!ti->type->iterate_devices ||
1841                     ti->type->iterate_devices(ti, device_not_write_zeroes_capable, NULL))
1842                         return false;
1843         }
1844
1845         return true;
1846 }
1847
1848 static int device_not_nowait_capable(struct dm_target *ti, struct dm_dev *dev,
1849                                      sector_t start, sector_t len, void *data)
1850 {
1851         return !bdev_nowait(dev->bdev);
1852 }
1853
1854 static bool dm_table_supports_nowait(struct dm_table *t)
1855 {
1856         for (unsigned int i = 0; i < t->num_targets; i++) {
1857                 struct dm_target *ti = dm_table_get_target(t, i);
1858
1859                 if (!dm_target_supports_nowait(ti->type))
1860                         return false;
1861
1862                 if (!ti->type->iterate_devices ||
1863                     ti->type->iterate_devices(ti, device_not_nowait_capable, NULL))
1864                         return false;
1865         }
1866
1867         return true;
1868 }
1869
1870 static int device_not_discard_capable(struct dm_target *ti, struct dm_dev *dev,
1871                                       sector_t start, sector_t len, void *data)
1872 {
1873         return !bdev_max_discard_sectors(dev->bdev);
1874 }
1875
1876 static bool dm_table_supports_discards(struct dm_table *t)
1877 {
1878         for (unsigned int i = 0; i < t->num_targets; i++) {
1879                 struct dm_target *ti = dm_table_get_target(t, i);
1880
1881                 if (!ti->num_discard_bios)
1882                         return false;
1883
1884                 /*
1885                  * Either the target provides discard support (as implied by setting
1886                  * 'discards_supported') or it relies on _all_ data devices having
1887                  * discard support.
1888                  */
1889                 if (!ti->discards_supported &&
1890                     (!ti->type->iterate_devices ||
1891                      ti->type->iterate_devices(ti, device_not_discard_capable, NULL)))
1892                         return false;
1893         }
1894
1895         return true;
1896 }
1897
1898 static int device_not_secure_erase_capable(struct dm_target *ti,
1899                                            struct dm_dev *dev, sector_t start,
1900                                            sector_t len, void *data)
1901 {
1902         return !bdev_max_secure_erase_sectors(dev->bdev);
1903 }
1904
1905 static bool dm_table_supports_secure_erase(struct dm_table *t)
1906 {
1907         for (unsigned int i = 0; i < t->num_targets; i++) {
1908                 struct dm_target *ti = dm_table_get_target(t, i);
1909
1910                 if (!ti->num_secure_erase_bios)
1911                         return false;
1912
1913                 if (!ti->type->iterate_devices ||
1914                     ti->type->iterate_devices(ti, device_not_secure_erase_capable, NULL))
1915                         return false;
1916         }
1917
1918         return true;
1919 }
1920
1921 static int device_requires_stable_pages(struct dm_target *ti,
1922                                         struct dm_dev *dev, sector_t start,
1923                                         sector_t len, void *data)
1924 {
1925         return bdev_stable_writes(dev->bdev);
1926 }
1927
1928 int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1929                               struct queue_limits *limits)
1930 {
1931         bool wc = false, fua = false;
1932         int r;
1933
1934         /*
1935          * Copy table's limits to the DM device's request_queue
1936          */
1937         q->limits = *limits;
1938
1939         if (dm_table_supports_nowait(t))
1940                 blk_queue_flag_set(QUEUE_FLAG_NOWAIT, q);
1941         else
1942                 blk_queue_flag_clear(QUEUE_FLAG_NOWAIT, q);
1943
1944         if (!dm_table_supports_discards(t)) {
1945                 q->limits.max_discard_sectors = 0;
1946                 q->limits.max_hw_discard_sectors = 0;
1947                 q->limits.discard_granularity = 0;
1948                 q->limits.discard_alignment = 0;
1949                 q->limits.discard_misaligned = 0;
1950         }
1951
1952         if (!dm_table_supports_secure_erase(t))
1953                 q->limits.max_secure_erase_sectors = 0;
1954
1955         if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_WC))) {
1956                 wc = true;
1957                 if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_FUA)))
1958                         fua = true;
1959         }
1960         blk_queue_write_cache(q, wc, fua);
1961
1962         if (dm_table_supports_dax(t, device_not_dax_capable)) {
1963                 blk_queue_flag_set(QUEUE_FLAG_DAX, q);
1964                 if (dm_table_supports_dax(t, device_not_dax_synchronous_capable))
1965                         set_dax_synchronous(t->md->dax_dev);
1966         } else
1967                 blk_queue_flag_clear(QUEUE_FLAG_DAX, q);
1968
1969         if (dm_table_any_dev_attr(t, device_dax_write_cache_enabled, NULL))
1970                 dax_write_cache(t->md->dax_dev, true);
1971
1972         /* Ensure that all underlying devices are non-rotational. */
1973         if (dm_table_any_dev_attr(t, device_is_rotational, NULL))
1974                 blk_queue_flag_clear(QUEUE_FLAG_NONROT, q);
1975         else
1976                 blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
1977
1978         if (!dm_table_supports_write_zeroes(t))
1979                 q->limits.max_write_zeroes_sectors = 0;
1980
1981         dm_table_verify_integrity(t);
1982
1983         /*
1984          * Some devices don't use blk_integrity but still want stable pages
1985          * because they do their own checksumming.
1986          * If any underlying device requires stable pages, a table must require
1987          * them as well.  Only targets that support iterate_devices are considered:
1988          * don't want error, zero, etc to require stable pages.
1989          */
1990         if (dm_table_any_dev_attr(t, device_requires_stable_pages, NULL))
1991                 blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, q);
1992         else
1993                 blk_queue_flag_clear(QUEUE_FLAG_STABLE_WRITES, q);
1994
1995         /*
1996          * Determine whether or not this queue's I/O timings contribute
1997          * to the entropy pool, Only request-based targets use this.
1998          * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
1999          * have it set.
2000          */
2001         if (blk_queue_add_random(q) &&
2002             dm_table_any_dev_attr(t, device_is_not_random, NULL))
2003                 blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, q);
2004
2005         /*
2006          * For a zoned target, setup the zones related queue attributes
2007          * and resources necessary for zone append emulation if necessary.
2008          */
2009         if (blk_queue_is_zoned(q)) {
2010                 r = dm_set_zones_restrictions(t, q);
2011                 if (r)
2012                         return r;
2013                 if (!static_key_enabled(&zoned_enabled.key))
2014                         static_branch_enable(&zoned_enabled);
2015         }
2016
2017         dm_update_crypto_profile(q, t);
2018         disk_update_readahead(t->md->disk);
2019
2020         /*
2021          * Check for request-based device is left to
2022          * dm_mq_init_request_queue()->blk_mq_init_allocated_queue().
2023          *
2024          * For bio-based device, only set QUEUE_FLAG_POLL when all
2025          * underlying devices supporting polling.
2026          */
2027         if (__table_type_bio_based(t->type)) {
2028                 if (dm_table_supports_poll(t))
2029                         blk_queue_flag_set(QUEUE_FLAG_POLL, q);
2030                 else
2031                         blk_queue_flag_clear(QUEUE_FLAG_POLL, q);
2032         }
2033
2034         return 0;
2035 }
2036
2037 struct list_head *dm_table_get_devices(struct dm_table *t)
2038 {
2039         return &t->devices;
2040 }
2041
2042 fmode_t dm_table_get_mode(struct dm_table *t)
2043 {
2044         return t->mode;
2045 }
2046 EXPORT_SYMBOL(dm_table_get_mode);
2047
2048 enum suspend_mode {
2049         PRESUSPEND,
2050         PRESUSPEND_UNDO,
2051         POSTSUSPEND,
2052 };
2053
2054 static void suspend_targets(struct dm_table *t, enum suspend_mode mode)
2055 {
2056         lockdep_assert_held(&t->md->suspend_lock);
2057
2058         for (unsigned int i = 0; i < t->num_targets; i++) {
2059                 struct dm_target *ti = dm_table_get_target(t, i);
2060
2061                 switch (mode) {
2062                 case PRESUSPEND:
2063                         if (ti->type->presuspend)
2064                                 ti->type->presuspend(ti);
2065                         break;
2066                 case PRESUSPEND_UNDO:
2067                         if (ti->type->presuspend_undo)
2068                                 ti->type->presuspend_undo(ti);
2069                         break;
2070                 case POSTSUSPEND:
2071                         if (ti->type->postsuspend)
2072                                 ti->type->postsuspend(ti);
2073                         break;
2074                 }
2075         }
2076 }
2077
2078 void dm_table_presuspend_targets(struct dm_table *t)
2079 {
2080         if (!t)
2081                 return;
2082
2083         suspend_targets(t, PRESUSPEND);
2084 }
2085
2086 void dm_table_presuspend_undo_targets(struct dm_table *t)
2087 {
2088         if (!t)
2089                 return;
2090
2091         suspend_targets(t, PRESUSPEND_UNDO);
2092 }
2093
2094 void dm_table_postsuspend_targets(struct dm_table *t)
2095 {
2096         if (!t)
2097                 return;
2098
2099         suspend_targets(t, POSTSUSPEND);
2100 }
2101
2102 int dm_table_resume_targets(struct dm_table *t)
2103 {
2104         unsigned int i;
2105         int r = 0;
2106
2107         lockdep_assert_held(&t->md->suspend_lock);
2108
2109         for (i = 0; i < t->num_targets; i++) {
2110                 struct dm_target *ti = dm_table_get_target(t, i);
2111
2112                 if (!ti->type->preresume)
2113                         continue;
2114
2115                 r = ti->type->preresume(ti);
2116                 if (r) {
2117                         DMERR("%s: %s: preresume failed, error = %d",
2118                               dm_device_name(t->md), ti->type->name, r);
2119                         return r;
2120                 }
2121         }
2122
2123         for (i = 0; i < t->num_targets; i++) {
2124                 struct dm_target *ti = dm_table_get_target(t, i);
2125
2126                 if (ti->type->resume)
2127                         ti->type->resume(ti);
2128         }
2129
2130         return 0;
2131 }
2132
2133 struct mapped_device *dm_table_get_md(struct dm_table *t)
2134 {
2135         return t->md;
2136 }
2137 EXPORT_SYMBOL(dm_table_get_md);
2138
2139 const char *dm_table_device_name(struct dm_table *t)
2140 {
2141         return dm_device_name(t->md);
2142 }
2143 EXPORT_SYMBOL_GPL(dm_table_device_name);
2144
2145 void dm_table_run_md_queue_async(struct dm_table *t)
2146 {
2147         if (!dm_table_request_based(t))
2148                 return;
2149
2150         if (t->md->queue)
2151                 blk_mq_run_hw_queues(t->md->queue, true);
2152 }
2153 EXPORT_SYMBOL(dm_table_run_md_queue_async);
2154