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 struct dm_keyslot_evict_args {
1206         const struct blk_crypto_key *key;
1207         int err;
1208 };
1209
1210 static int dm_keyslot_evict_callback(struct dm_target *ti, struct dm_dev *dev,
1211                                      sector_t start, sector_t len, void *data)
1212 {
1213         struct dm_keyslot_evict_args *args = data;
1214         int err;
1215
1216         err = blk_crypto_evict_key(dev->bdev, args->key);
1217         if (!args->err)
1218                 args->err = err;
1219         /* Always try to evict the key from all devices. */
1220         return 0;
1221 }
1222
1223 /*
1224  * When an inline encryption key is evicted from a device-mapper device, evict
1225  * it from all the underlying devices.
1226  */
1227 static int dm_keyslot_evict(struct blk_crypto_profile *profile,
1228                             const struct blk_crypto_key *key, unsigned int slot)
1229 {
1230         struct mapped_device *md =
1231                 container_of(profile, struct dm_crypto_profile, profile)->md;
1232         struct dm_keyslot_evict_args args = { key };
1233         struct dm_table *t;
1234         int srcu_idx;
1235
1236         t = dm_get_live_table(md, &srcu_idx);
1237         if (!t)
1238                 return 0;
1239
1240         for (unsigned int i = 0; i < t->num_targets; i++) {
1241                 struct dm_target *ti = dm_table_get_target(t, i);
1242
1243                 if (!ti->type->iterate_devices)
1244                         continue;
1245                 ti->type->iterate_devices(ti, dm_keyslot_evict_callback, &args);
1246         }
1247
1248         dm_put_live_table(md, srcu_idx);
1249         return args.err;
1250 }
1251
1252 static int
1253 device_intersect_crypto_capabilities(struct dm_target *ti, struct dm_dev *dev,
1254                                      sector_t start, sector_t len, void *data)
1255 {
1256         struct blk_crypto_profile *parent = data;
1257         struct blk_crypto_profile *child =
1258                 bdev_get_queue(dev->bdev)->crypto_profile;
1259
1260         blk_crypto_intersect_capabilities(parent, child);
1261         return 0;
1262 }
1263
1264 void dm_destroy_crypto_profile(struct blk_crypto_profile *profile)
1265 {
1266         struct dm_crypto_profile *dmcp = container_of(profile,
1267                                                       struct dm_crypto_profile,
1268                                                       profile);
1269
1270         if (!profile)
1271                 return;
1272
1273         blk_crypto_profile_destroy(profile);
1274         kfree(dmcp);
1275 }
1276
1277 static void dm_table_destroy_crypto_profile(struct dm_table *t)
1278 {
1279         dm_destroy_crypto_profile(t->crypto_profile);
1280         t->crypto_profile = NULL;
1281 }
1282
1283 /*
1284  * Constructs and initializes t->crypto_profile with a crypto profile that
1285  * represents the common set of crypto capabilities of the devices described by
1286  * the dm_table.  However, if the constructed crypto profile doesn't support all
1287  * crypto capabilities that are supported by the current mapped_device, it
1288  * returns an error instead, since we don't support removing crypto capabilities
1289  * on table changes.  Finally, if the constructed crypto profile is "empty" (has
1290  * no crypto capabilities at all), it just sets t->crypto_profile to NULL.
1291  */
1292 static int dm_table_construct_crypto_profile(struct dm_table *t)
1293 {
1294         struct dm_crypto_profile *dmcp;
1295         struct blk_crypto_profile *profile;
1296         unsigned int i;
1297         bool empty_profile = true;
1298
1299         dmcp = kmalloc(sizeof(*dmcp), GFP_KERNEL);
1300         if (!dmcp)
1301                 return -ENOMEM;
1302         dmcp->md = t->md;
1303
1304         profile = &dmcp->profile;
1305         blk_crypto_profile_init(profile, 0);
1306         profile->ll_ops.keyslot_evict = dm_keyslot_evict;
1307         profile->max_dun_bytes_supported = UINT_MAX;
1308         memset(profile->modes_supported, 0xFF,
1309                sizeof(profile->modes_supported));
1310
1311         for (i = 0; i < t->num_targets; i++) {
1312                 struct dm_target *ti = dm_table_get_target(t, i);
1313
1314                 if (!dm_target_passes_crypto(ti->type)) {
1315                         blk_crypto_intersect_capabilities(profile, NULL);
1316                         break;
1317                 }
1318                 if (!ti->type->iterate_devices)
1319                         continue;
1320                 ti->type->iterate_devices(ti,
1321                                           device_intersect_crypto_capabilities,
1322                                           profile);
1323         }
1324
1325         if (t->md->queue &&
1326             !blk_crypto_has_capabilities(profile,
1327                                          t->md->queue->crypto_profile)) {
1328                 DMERR("Inline encryption capabilities of new DM table were more restrictive than the old table's. This is not supported!");
1329                 dm_destroy_crypto_profile(profile);
1330                 return -EINVAL;
1331         }
1332
1333         /*
1334          * If the new profile doesn't actually support any crypto capabilities,
1335          * we may as well represent it with a NULL profile.
1336          */
1337         for (i = 0; i < ARRAY_SIZE(profile->modes_supported); i++) {
1338                 if (profile->modes_supported[i]) {
1339                         empty_profile = false;
1340                         break;
1341                 }
1342         }
1343
1344         if (empty_profile) {
1345                 dm_destroy_crypto_profile(profile);
1346                 profile = NULL;
1347         }
1348
1349         /*
1350          * t->crypto_profile is only set temporarily while the table is being
1351          * set up, and it gets set to NULL after the profile has been
1352          * transferred to the request_queue.
1353          */
1354         t->crypto_profile = profile;
1355
1356         return 0;
1357 }
1358
1359 static void dm_update_crypto_profile(struct request_queue *q,
1360                                      struct dm_table *t)
1361 {
1362         if (!t->crypto_profile)
1363                 return;
1364
1365         /* Make the crypto profile less restrictive. */
1366         if (!q->crypto_profile) {
1367                 blk_crypto_register(t->crypto_profile, q);
1368         } else {
1369                 blk_crypto_update_capabilities(q->crypto_profile,
1370                                                t->crypto_profile);
1371                 dm_destroy_crypto_profile(t->crypto_profile);
1372         }
1373         t->crypto_profile = NULL;
1374 }
1375
1376 #else /* CONFIG_BLK_INLINE_ENCRYPTION */
1377
1378 static int dm_table_construct_crypto_profile(struct dm_table *t)
1379 {
1380         return 0;
1381 }
1382
1383 void dm_destroy_crypto_profile(struct blk_crypto_profile *profile)
1384 {
1385 }
1386
1387 static void dm_table_destroy_crypto_profile(struct dm_table *t)
1388 {
1389 }
1390
1391 static void dm_update_crypto_profile(struct request_queue *q,
1392                                      struct dm_table *t)
1393 {
1394 }
1395
1396 #endif /* !CONFIG_BLK_INLINE_ENCRYPTION */
1397
1398 /*
1399  * Prepares the table for use by building the indices,
1400  * setting the type, and allocating mempools.
1401  */
1402 int dm_table_complete(struct dm_table *t)
1403 {
1404         int r;
1405
1406         r = dm_table_determine_type(t);
1407         if (r) {
1408                 DMERR("unable to determine table type");
1409                 return r;
1410         }
1411
1412         r = dm_table_build_index(t);
1413         if (r) {
1414                 DMERR("unable to build btrees");
1415                 return r;
1416         }
1417
1418         r = dm_table_register_integrity(t);
1419         if (r) {
1420                 DMERR("could not register integrity profile.");
1421                 return r;
1422         }
1423
1424         r = dm_table_construct_crypto_profile(t);
1425         if (r) {
1426                 DMERR("could not construct crypto profile.");
1427                 return r;
1428         }
1429
1430         r = dm_table_alloc_md_mempools(t, t->md);
1431         if (r)
1432                 DMERR("unable to allocate mempools");
1433
1434         return r;
1435 }
1436
1437 static DEFINE_MUTEX(_event_lock);
1438 void dm_table_event_callback(struct dm_table *t,
1439                              void (*fn)(void *), void *context)
1440 {
1441         mutex_lock(&_event_lock);
1442         t->event_fn = fn;
1443         t->event_context = context;
1444         mutex_unlock(&_event_lock);
1445 }
1446
1447 void dm_table_event(struct dm_table *t)
1448 {
1449         mutex_lock(&_event_lock);
1450         if (t->event_fn)
1451                 t->event_fn(t->event_context);
1452         mutex_unlock(&_event_lock);
1453 }
1454 EXPORT_SYMBOL(dm_table_event);
1455
1456 inline sector_t dm_table_get_size(struct dm_table *t)
1457 {
1458         return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1459 }
1460 EXPORT_SYMBOL(dm_table_get_size);
1461
1462 /*
1463  * Search the btree for the correct target.
1464  *
1465  * Caller should check returned pointer for NULL
1466  * to trap I/O beyond end of device.
1467  */
1468 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1469 {
1470         unsigned int l, n = 0, k = 0;
1471         sector_t *node;
1472
1473         if (unlikely(sector >= dm_table_get_size(t)))
1474                 return NULL;
1475
1476         for (l = 0; l < t->depth; l++) {
1477                 n = get_child(n, k);
1478                 node = get_node(t, l, n);
1479
1480                 for (k = 0; k < KEYS_PER_NODE; k++)
1481                         if (node[k] >= sector)
1482                                 break;
1483         }
1484
1485         return &t->targets[(KEYS_PER_NODE * n) + k];
1486 }
1487
1488 static int device_not_poll_capable(struct dm_target *ti, struct dm_dev *dev,
1489                                    sector_t start, sector_t len, void *data)
1490 {
1491         struct request_queue *q = bdev_get_queue(dev->bdev);
1492
1493         return !test_bit(QUEUE_FLAG_POLL, &q->queue_flags);
1494 }
1495
1496 /*
1497  * type->iterate_devices() should be called when the sanity check needs to
1498  * iterate and check all underlying data devices. iterate_devices() will
1499  * iterate all underlying data devices until it encounters a non-zero return
1500  * code, returned by whether the input iterate_devices_callout_fn, or
1501  * iterate_devices() itself internally.
1502  *
1503  * For some target type (e.g. dm-stripe), one call of iterate_devices() may
1504  * iterate multiple underlying devices internally, in which case a non-zero
1505  * return code returned by iterate_devices_callout_fn will stop the iteration
1506  * in advance.
1507  *
1508  * Cases requiring _any_ underlying device supporting some kind of attribute,
1509  * should use the iteration structure like dm_table_any_dev_attr(), or call
1510  * it directly. @func should handle semantics of positive examples, e.g.
1511  * capable of something.
1512  *
1513  * Cases requiring _all_ underlying devices supporting some kind of attribute,
1514  * should use the iteration structure like dm_table_supports_nowait() or
1515  * dm_table_supports_discards(). Or introduce dm_table_all_devs_attr() that
1516  * uses an @anti_func that handle semantics of counter examples, e.g. not
1517  * capable of something. So: return !dm_table_any_dev_attr(t, anti_func, data);
1518  */
1519 static bool dm_table_any_dev_attr(struct dm_table *t,
1520                                   iterate_devices_callout_fn func, void *data)
1521 {
1522         for (unsigned int i = 0; i < t->num_targets; i++) {
1523                 struct dm_target *ti = dm_table_get_target(t, i);
1524
1525                 if (ti->type->iterate_devices &&
1526                     ti->type->iterate_devices(ti, func, data))
1527                         return true;
1528         }
1529
1530         return false;
1531 }
1532
1533 static int count_device(struct dm_target *ti, struct dm_dev *dev,
1534                         sector_t start, sector_t len, void *data)
1535 {
1536         unsigned int *num_devices = data;
1537
1538         (*num_devices)++;
1539
1540         return 0;
1541 }
1542
1543 static bool dm_table_supports_poll(struct dm_table *t)
1544 {
1545         for (unsigned int i = 0; i < t->num_targets; i++) {
1546                 struct dm_target *ti = dm_table_get_target(t, i);
1547
1548                 if (!ti->type->iterate_devices ||
1549                     ti->type->iterate_devices(ti, device_not_poll_capable, NULL))
1550                         return false;
1551         }
1552
1553         return true;
1554 }
1555
1556 /*
1557  * Check whether a table has no data devices attached using each
1558  * target's iterate_devices method.
1559  * Returns false if the result is unknown because a target doesn't
1560  * support iterate_devices.
1561  */
1562 bool dm_table_has_no_data_devices(struct dm_table *t)
1563 {
1564         for (unsigned int i = 0; i < t->num_targets; i++) {
1565                 struct dm_target *ti = dm_table_get_target(t, i);
1566                 unsigned int num_devices = 0;
1567
1568                 if (!ti->type->iterate_devices)
1569                         return false;
1570
1571                 ti->type->iterate_devices(ti, count_device, &num_devices);
1572                 if (num_devices)
1573                         return false;
1574         }
1575
1576         return true;
1577 }
1578
1579 static int device_not_zoned_model(struct dm_target *ti, struct dm_dev *dev,
1580                                   sector_t start, sector_t len, void *data)
1581 {
1582         struct request_queue *q = bdev_get_queue(dev->bdev);
1583         enum blk_zoned_model *zoned_model = data;
1584
1585         return blk_queue_zoned_model(q) != *zoned_model;
1586 }
1587
1588 /*
1589  * Check the device zoned model based on the target feature flag. If the target
1590  * has the DM_TARGET_ZONED_HM feature flag set, host-managed zoned devices are
1591  * also accepted but all devices must have the same zoned model. If the target
1592  * has the DM_TARGET_MIXED_ZONED_MODEL feature set, the devices can have any
1593  * zoned model with all zoned devices having the same zone size.
1594  */
1595 static bool dm_table_supports_zoned_model(struct dm_table *t,
1596                                           enum blk_zoned_model zoned_model)
1597 {
1598         for (unsigned int i = 0; i < t->num_targets; i++) {
1599                 struct dm_target *ti = dm_table_get_target(t, i);
1600
1601                 if (dm_target_supports_zoned_hm(ti->type)) {
1602                         if (!ti->type->iterate_devices ||
1603                             ti->type->iterate_devices(ti, device_not_zoned_model,
1604                                                       &zoned_model))
1605                                 return false;
1606                 } else if (!dm_target_supports_mixed_zoned_model(ti->type)) {
1607                         if (zoned_model == BLK_ZONED_HM)
1608                                 return false;
1609                 }
1610         }
1611
1612         return true;
1613 }
1614
1615 static int device_not_matches_zone_sectors(struct dm_target *ti, struct dm_dev *dev,
1616                                            sector_t start, sector_t len, void *data)
1617 {
1618         unsigned int *zone_sectors = data;
1619
1620         if (!bdev_is_zoned(dev->bdev))
1621                 return 0;
1622         return bdev_zone_sectors(dev->bdev) != *zone_sectors;
1623 }
1624
1625 /*
1626  * Check consistency of zoned model and zone sectors across all targets. For
1627  * zone sectors, if the destination device is a zoned block device, it shall
1628  * have the specified zone_sectors.
1629  */
1630 static int validate_hardware_zoned_model(struct dm_table *t,
1631                                          enum blk_zoned_model zoned_model,
1632                                          unsigned int zone_sectors)
1633 {
1634         if (zoned_model == BLK_ZONED_NONE)
1635                 return 0;
1636
1637         if (!dm_table_supports_zoned_model(t, zoned_model)) {
1638                 DMERR("%s: zoned model is not consistent across all devices",
1639                       dm_device_name(t->md));
1640                 return -EINVAL;
1641         }
1642
1643         /* Check zone size validity and compatibility */
1644         if (!zone_sectors || !is_power_of_2(zone_sectors))
1645                 return -EINVAL;
1646
1647         if (dm_table_any_dev_attr(t, device_not_matches_zone_sectors, &zone_sectors)) {
1648                 DMERR("%s: zone sectors is not consistent across all zoned devices",
1649                       dm_device_name(t->md));
1650                 return -EINVAL;
1651         }
1652
1653         return 0;
1654 }
1655
1656 /*
1657  * Establish the new table's queue_limits and validate them.
1658  */
1659 int dm_calculate_queue_limits(struct dm_table *t,
1660                               struct queue_limits *limits)
1661 {
1662         struct queue_limits ti_limits;
1663         enum blk_zoned_model zoned_model = BLK_ZONED_NONE;
1664         unsigned int zone_sectors = 0;
1665
1666         blk_set_stacking_limits(limits);
1667
1668         for (unsigned int i = 0; i < t->num_targets; i++) {
1669                 struct dm_target *ti = dm_table_get_target(t, i);
1670
1671                 blk_set_stacking_limits(&ti_limits);
1672
1673                 if (!ti->type->iterate_devices)
1674                         goto combine_limits;
1675
1676                 /*
1677                  * Combine queue limits of all the devices this target uses.
1678                  */
1679                 ti->type->iterate_devices(ti, dm_set_device_limits,
1680                                           &ti_limits);
1681
1682                 if (zoned_model == BLK_ZONED_NONE && ti_limits.zoned != BLK_ZONED_NONE) {
1683                         /*
1684                          * After stacking all limits, validate all devices
1685                          * in table support this zoned model and zone sectors.
1686                          */
1687                         zoned_model = ti_limits.zoned;
1688                         zone_sectors = ti_limits.chunk_sectors;
1689                 }
1690
1691                 /* Set I/O hints portion of queue limits */
1692                 if (ti->type->io_hints)
1693                         ti->type->io_hints(ti, &ti_limits);
1694
1695                 /*
1696                  * Check each device area is consistent with the target's
1697                  * overall queue limits.
1698                  */
1699                 if (ti->type->iterate_devices(ti, device_area_is_invalid,
1700                                               &ti_limits))
1701                         return -EINVAL;
1702
1703 combine_limits:
1704                 /*
1705                  * Merge this target's queue limits into the overall limits
1706                  * for the table.
1707                  */
1708                 if (blk_stack_limits(limits, &ti_limits, 0) < 0)
1709                         DMWARN("%s: adding target device (start sect %llu len %llu) "
1710                                "caused an alignment inconsistency",
1711                                dm_device_name(t->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(t, zoned_model, zone_sectors))
1732                 return -EINVAL;
1733
1734         return validate_hardware_logical_block_alignment(t, 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         /*
1779          * Require at least one underlying device to support flushes.
1780          * t->devices includes internal dm devices such as mirror logs
1781          * so we need to use iterate_devices here, which targets
1782          * supporting flushes must provide.
1783          */
1784         for (unsigned int i = 0; i < t->num_targets; i++) {
1785                 struct dm_target *ti = dm_table_get_target(t, i);
1786
1787                 if (!ti->num_flush_bios)
1788                         continue;
1789
1790                 if (ti->flush_supported)
1791                         return true;
1792
1793                 if (ti->type->iterate_devices &&
1794                     ti->type->iterate_devices(ti, device_flush_capable, (void *) flush))
1795                         return true;
1796         }
1797
1798         return false;
1799 }
1800
1801 static int device_dax_write_cache_enabled(struct dm_target *ti,
1802                                           struct dm_dev *dev, sector_t start,
1803                                           sector_t len, void *data)
1804 {
1805         struct dax_device *dax_dev = dev->dax_dev;
1806
1807         if (!dax_dev)
1808                 return false;
1809
1810         if (dax_write_cache_enabled(dax_dev))
1811                 return true;
1812         return false;
1813 }
1814
1815 static int device_is_rotational(struct dm_target *ti, struct dm_dev *dev,
1816                                 sector_t start, sector_t len, void *data)
1817 {
1818         return !bdev_nonrot(dev->bdev);
1819 }
1820
1821 static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
1822                              sector_t start, sector_t len, void *data)
1823 {
1824         struct request_queue *q = bdev_get_queue(dev->bdev);
1825
1826         return !blk_queue_add_random(q);
1827 }
1828
1829 static int device_not_write_zeroes_capable(struct dm_target *ti, struct dm_dev *dev,
1830                                            sector_t start, sector_t len, void *data)
1831 {
1832         struct request_queue *q = bdev_get_queue(dev->bdev);
1833
1834         return !q->limits.max_write_zeroes_sectors;
1835 }
1836
1837 static bool dm_table_supports_write_zeroes(struct dm_table *t)
1838 {
1839         for (unsigned int i = 0; i < t->num_targets; i++) {
1840                 struct dm_target *ti = dm_table_get_target(t, i);
1841
1842                 if (!ti->num_write_zeroes_bios)
1843                         return false;
1844
1845                 if (!ti->type->iterate_devices ||
1846                     ti->type->iterate_devices(ti, device_not_write_zeroes_capable, NULL))
1847                         return false;
1848         }
1849
1850         return true;
1851 }
1852
1853 static int device_not_nowait_capable(struct dm_target *ti, struct dm_dev *dev,
1854                                      sector_t start, sector_t len, void *data)
1855 {
1856         return !bdev_nowait(dev->bdev);
1857 }
1858
1859 static bool dm_table_supports_nowait(struct dm_table *t)
1860 {
1861         for (unsigned int i = 0; i < t->num_targets; i++) {
1862                 struct dm_target *ti = dm_table_get_target(t, i);
1863
1864                 if (!dm_target_supports_nowait(ti->type))
1865                         return false;
1866
1867                 if (!ti->type->iterate_devices ||
1868                     ti->type->iterate_devices(ti, device_not_nowait_capable, NULL))
1869                         return false;
1870         }
1871
1872         return true;
1873 }
1874
1875 static int device_not_discard_capable(struct dm_target *ti, struct dm_dev *dev,
1876                                       sector_t start, sector_t len, void *data)
1877 {
1878         return !bdev_max_discard_sectors(dev->bdev);
1879 }
1880
1881 static bool dm_table_supports_discards(struct dm_table *t)
1882 {
1883         for (unsigned int i = 0; i < t->num_targets; i++) {
1884                 struct dm_target *ti = dm_table_get_target(t, i);
1885
1886                 if (!ti->num_discard_bios)
1887                         return false;
1888
1889                 /*
1890                  * Either the target provides discard support (as implied by setting
1891                  * 'discards_supported') or it relies on _all_ data devices having
1892                  * discard support.
1893                  */
1894                 if (!ti->discards_supported &&
1895                     (!ti->type->iterate_devices ||
1896                      ti->type->iterate_devices(ti, device_not_discard_capable, NULL)))
1897                         return false;
1898         }
1899
1900         return true;
1901 }
1902
1903 static int device_not_secure_erase_capable(struct dm_target *ti,
1904                                            struct dm_dev *dev, sector_t start,
1905                                            sector_t len, void *data)
1906 {
1907         return !bdev_max_secure_erase_sectors(dev->bdev);
1908 }
1909
1910 static bool dm_table_supports_secure_erase(struct dm_table *t)
1911 {
1912         for (unsigned int i = 0; i < t->num_targets; i++) {
1913                 struct dm_target *ti = dm_table_get_target(t, i);
1914
1915                 if (!ti->num_secure_erase_bios)
1916                         return false;
1917
1918                 if (!ti->type->iterate_devices ||
1919                     ti->type->iterate_devices(ti, device_not_secure_erase_capable, NULL))
1920                         return false;
1921         }
1922
1923         return true;
1924 }
1925
1926 static int device_requires_stable_pages(struct dm_target *ti,
1927                                         struct dm_dev *dev, sector_t start,
1928                                         sector_t len, void *data)
1929 {
1930         return bdev_stable_writes(dev->bdev);
1931 }
1932
1933 int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1934                               struct queue_limits *limits)
1935 {
1936         bool wc = false, fua = false;
1937         int r;
1938
1939         /*
1940          * Copy table's limits to the DM device's request_queue
1941          */
1942         q->limits = *limits;
1943
1944         if (dm_table_supports_nowait(t))
1945                 blk_queue_flag_set(QUEUE_FLAG_NOWAIT, q);
1946         else
1947                 blk_queue_flag_clear(QUEUE_FLAG_NOWAIT, q);
1948
1949         if (!dm_table_supports_discards(t)) {
1950                 q->limits.max_discard_sectors = 0;
1951                 q->limits.max_hw_discard_sectors = 0;
1952                 q->limits.discard_granularity = 0;
1953                 q->limits.discard_alignment = 0;
1954                 q->limits.discard_misaligned = 0;
1955         }
1956
1957         if (!dm_table_supports_secure_erase(t))
1958                 q->limits.max_secure_erase_sectors = 0;
1959
1960         if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_WC))) {
1961                 wc = true;
1962                 if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_FUA)))
1963                         fua = true;
1964         }
1965         blk_queue_write_cache(q, wc, fua);
1966
1967         if (dm_table_supports_dax(t, device_not_dax_capable)) {
1968                 blk_queue_flag_set(QUEUE_FLAG_DAX, q);
1969                 if (dm_table_supports_dax(t, device_not_dax_synchronous_capable))
1970                         set_dax_synchronous(t->md->dax_dev);
1971         } else
1972                 blk_queue_flag_clear(QUEUE_FLAG_DAX, q);
1973
1974         if (dm_table_any_dev_attr(t, device_dax_write_cache_enabled, NULL))
1975                 dax_write_cache(t->md->dax_dev, true);
1976
1977         /* Ensure that all underlying devices are non-rotational. */
1978         if (dm_table_any_dev_attr(t, device_is_rotational, NULL))
1979                 blk_queue_flag_clear(QUEUE_FLAG_NONROT, q);
1980         else
1981                 blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
1982
1983         if (!dm_table_supports_write_zeroes(t))
1984                 q->limits.max_write_zeroes_sectors = 0;
1985
1986         dm_table_verify_integrity(t);
1987
1988         /*
1989          * Some devices don't use blk_integrity but still want stable pages
1990          * because they do their own checksumming.
1991          * If any underlying device requires stable pages, a table must require
1992          * them as well.  Only targets that support iterate_devices are considered:
1993          * don't want error, zero, etc to require stable pages.
1994          */
1995         if (dm_table_any_dev_attr(t, device_requires_stable_pages, NULL))
1996                 blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, q);
1997         else
1998                 blk_queue_flag_clear(QUEUE_FLAG_STABLE_WRITES, q);
1999
2000         /*
2001          * Determine whether or not this queue's I/O timings contribute
2002          * to the entropy pool, Only request-based targets use this.
2003          * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
2004          * have it set.
2005          */
2006         if (blk_queue_add_random(q) &&
2007             dm_table_any_dev_attr(t, device_is_not_random, NULL))
2008                 blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, q);
2009
2010         /*
2011          * For a zoned target, setup the zones related queue attributes
2012          * and resources necessary for zone append emulation if necessary.
2013          */
2014         if (blk_queue_is_zoned(q)) {
2015                 r = dm_set_zones_restrictions(t, q);
2016                 if (r)
2017                         return r;
2018                 if (!static_key_enabled(&zoned_enabled.key))
2019                         static_branch_enable(&zoned_enabled);
2020         }
2021
2022         dm_update_crypto_profile(q, t);
2023         disk_update_readahead(t->md->disk);
2024
2025         /*
2026          * Check for request-based device is left to
2027          * dm_mq_init_request_queue()->blk_mq_init_allocated_queue().
2028          *
2029          * For bio-based device, only set QUEUE_FLAG_POLL when all
2030          * underlying devices supporting polling.
2031          */
2032         if (__table_type_bio_based(t->type)) {
2033                 if (dm_table_supports_poll(t))
2034                         blk_queue_flag_set(QUEUE_FLAG_POLL, q);
2035                 else
2036                         blk_queue_flag_clear(QUEUE_FLAG_POLL, q);
2037         }
2038
2039         return 0;
2040 }
2041
2042 struct list_head *dm_table_get_devices(struct dm_table *t)
2043 {
2044         return &t->devices;
2045 }
2046
2047 fmode_t dm_table_get_mode(struct dm_table *t)
2048 {
2049         return t->mode;
2050 }
2051 EXPORT_SYMBOL(dm_table_get_mode);
2052
2053 enum suspend_mode {
2054         PRESUSPEND,
2055         PRESUSPEND_UNDO,
2056         POSTSUSPEND,
2057 };
2058
2059 static void suspend_targets(struct dm_table *t, enum suspend_mode mode)
2060 {
2061         lockdep_assert_held(&t->md->suspend_lock);
2062
2063         for (unsigned int i = 0; i < t->num_targets; i++) {
2064                 struct dm_target *ti = dm_table_get_target(t, i);
2065
2066                 switch (mode) {
2067                 case PRESUSPEND:
2068                         if (ti->type->presuspend)
2069                                 ti->type->presuspend(ti);
2070                         break;
2071                 case PRESUSPEND_UNDO:
2072                         if (ti->type->presuspend_undo)
2073                                 ti->type->presuspend_undo(ti);
2074                         break;
2075                 case POSTSUSPEND:
2076                         if (ti->type->postsuspend)
2077                                 ti->type->postsuspend(ti);
2078                         break;
2079                 }
2080         }
2081 }
2082
2083 void dm_table_presuspend_targets(struct dm_table *t)
2084 {
2085         if (!t)
2086                 return;
2087
2088         suspend_targets(t, PRESUSPEND);
2089 }
2090
2091 void dm_table_presuspend_undo_targets(struct dm_table *t)
2092 {
2093         if (!t)
2094                 return;
2095
2096         suspend_targets(t, PRESUSPEND_UNDO);
2097 }
2098
2099 void dm_table_postsuspend_targets(struct dm_table *t)
2100 {
2101         if (!t)
2102                 return;
2103
2104         suspend_targets(t, POSTSUSPEND);
2105 }
2106
2107 int dm_table_resume_targets(struct dm_table *t)
2108 {
2109         unsigned int i;
2110         int r = 0;
2111
2112         lockdep_assert_held(&t->md->suspend_lock);
2113
2114         for (i = 0; i < t->num_targets; i++) {
2115                 struct dm_target *ti = dm_table_get_target(t, i);
2116
2117                 if (!ti->type->preresume)
2118                         continue;
2119
2120                 r = ti->type->preresume(ti);
2121                 if (r) {
2122                         DMERR("%s: %s: preresume failed, error = %d",
2123                               dm_device_name(t->md), ti->type->name, r);
2124                         return r;
2125                 }
2126         }
2127
2128         for (i = 0; i < t->num_targets; i++) {
2129                 struct dm_target *ti = dm_table_get_target(t, i);
2130
2131                 if (ti->type->resume)
2132                         ti->type->resume(ti);
2133         }
2134
2135         return 0;
2136 }
2137
2138 struct mapped_device *dm_table_get_md(struct dm_table *t)
2139 {
2140         return t->md;
2141 }
2142 EXPORT_SYMBOL(dm_table_get_md);
2143
2144 const char *dm_table_device_name(struct dm_table *t)
2145 {
2146         return dm_device_name(t->md);
2147 }
2148 EXPORT_SYMBOL_GPL(dm_table_device_name);
2149
2150 void dm_table_run_md_queue_async(struct dm_table *t)
2151 {
2152         if (!dm_table_request_based(t))
2153                 return;
2154
2155         if (t->md->queue)
2156                 blk_mq_run_hw_queues(t->md->queue, true);
2157 }
2158 EXPORT_SYMBOL(dm_table_run_md_queue_async);
2159