drivers/md/dm-table.c

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