root/drivers/md/dm-table.c

DEFINITIONS

1. int_log
2. get_child
3. get_node
4. high
5. setup_btree_index
6. dm_vcalloc
7. alloc_targets
8. dm_table_create
9. free_devices
10. dm_table_destroy
11. find_device
12. device_area_is_invalid
13. upgrade_mode
14. dm_get_dev_t
15. dm_get_device
16. dm_set_device_limits
17. dm_put_device
18. adjoin
19. realloc_argv
20. dm_split_args
21. validate_hardware_logical_block_alignment
22. dm_table_add_target
23. validate_next_arg
24. dm_read_arg
25. dm_read_arg_group
26. dm_shift_arg
27. dm_consume_args
28. __table_type_bio_based
29. __table_type_request_based
30. dm_table_set_type
31. device_supports_dax
32. device_dax_synchronous
33. dm_table_supports_dax
34. device_is_rq_based
35. dm_table_determine_type
36. dm_table_get_type
37. dm_table_get_immutable_target_type
38. dm_table_get_immutable_target
39. dm_table_get_wildcard_target
40. dm_table_bio_based
41. dm_table_request_based
42. dm_table_alloc_md_mempools
43. dm_table_free_md_mempools
44. dm_table_get_md_mempools
45. setup_indexes
46. dm_table_build_index
47. integrity_profile_exists
48. dm_table_get_integrity_disk
49. dm_table_register_integrity
50. dm_table_complete
51. dm_table_event_callback
52. dm_table_event
53. dm_table_get_size
54. dm_table_get_target
55. dm_table_find_target
56. count_device
57. dm_table_has_no_data_devices
58. device_is_zoned_model
59. dm_table_supports_zoned_model
60. device_matches_zone_sectors
61. dm_table_matches_zone_sectors
62. validate_hardware_zoned_model
63. dm_calculate_queue_limits
64. dm_table_verify_integrity
65. device_flush_capable
66. dm_table_supports_flush
67. device_dax_write_cache_enabled
68. dm_table_supports_dax_write_cache
69. device_is_nonrot
70. device_is_not_random
71. dm_table_all_devices_attribute
72. device_no_partial_completion
73. dm_table_does_not_support_partial_completion
74. device_not_write_same_capable
75. dm_table_supports_write_same
76. device_not_write_zeroes_capable
77. dm_table_supports_write_zeroes
78. device_not_discard_capable
79. dm_table_supports_discards
80. device_not_secure_erase_capable
81. dm_table_supports_secure_erase
82. device_requires_stable_pages
83. dm_table_requires_stable_pages
84. dm_table_set_restrictions
85. dm_table_get_num_targets
86. dm_table_get_devices
87. dm_table_get_mode
88. suspend_targets
89. dm_table_presuspend_targets
90. dm_table_presuspend_undo_targets
91. dm_table_postsuspend_targets
92. dm_table_resume_targets
93. dm_table_add_target_callbacks
94. dm_table_any_congested
95. dm_table_get_md
96. dm_table_device_name
97. dm_table_run_md_queue_async

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