drivers/md/dm-table.c

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