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/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 NODE_SIZE L1_CACHE_BYTES
  28 #define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t))
  29 #define CHILDREN_PER_NODE (KEYS_PER_NODE + 1)
  30
  31 /*
  32  * Similar to ceiling(log_size(n))
  33  */
  34 static unsigned int int_log(unsigned int n, unsigned int base)
  35 {
  36         int result = 0;
  37
  38         while (n > 1) {
  39                 n = dm_div_up(n, base);
  40                 result++;
  41         }
  42
  43         return result;
  44 }
  45
  46 /*
  47  * Calculate the index of the child node of the n'th node k'th key.
  48  */
  49 static inline unsigned int get_child(unsigned int n, unsigned int k)
  50 {
  51         return (n * CHILDREN_PER_NODE) + k;
  52 }
  53
  54 /*
  55  * Return the n'th node of level l from table t.
  56  */
  57 static inline sector_t *get_node(struct dm_table *t,
  58                                  unsigned int l, unsigned int n)
  59 {
  60         return t->index[l] + (n * KEYS_PER_NODE);
  61 }
  62
  63 /*
  64  * Return the highest key that you could lookup from the n'th
  65  * node on level l of the btree.
  66  */
  67 static sector_t high(struct dm_table *t, unsigned int l, unsigned int n)
  68 {
  69         for (; l < t->depth - 1; l++)
  70                 n = get_child(n, CHILDREN_PER_NODE - 1);
  71
  72         if (n >= t->counts[l])
  73                 return (sector_t) - 1;
  74
  75         return get_node(t, l, n)[KEYS_PER_NODE - 1];
  76 }
  77
  78 /*
  79  * Fills in a level of the btree based on the highs of the level
  80  * below it.
  81  */
  82 static int setup_btree_index(unsigned int l, struct dm_table *t)
  83 {
  84         unsigned int n, k;
  85         sector_t *node;
  86
  87         for (n = 0U; n < t->counts[l]; n++) {
  88                 node = get_node(t, l, n);
  89
  90                 for (k = 0U; k < KEYS_PER_NODE; k++)
  91                         node[k] = high(t, l + 1, get_child(n, k));
  92         }
  93
  94         return 0;
  95 }
  96
  97 /*
  98  * highs, and targets are managed as dynamic arrays during a
  99  * table load.
 100  */
 101 static int alloc_targets(struct dm_table *t, unsigned int num)
 102 {
 103         sector_t *n_highs;
 104         struct dm_target *n_targets;
 105
 106         /*
 107          * Allocate both the target array and offset array at once.
 108          */
 109         n_highs = kvcalloc(num, sizeof(struct dm_target) + sizeof(sector_t),
 110                            GFP_KERNEL);
 111         if (!n_highs)
 112                 return -ENOMEM;
 113
 114         n_targets = (struct dm_target *) (n_highs + num);
 115
 116         memset(n_highs, -1, sizeof(*n_highs) * num);
 117         kvfree(t->highs);
 118
 119         t->num_allocated = num;
 120         t->highs = n_highs;
 121         t->targets = n_targets;
 122
 123         return 0;
 124 }
 125
 126 int dm_table_create(struct dm_table **result, fmode_t mode,
 127                     unsigned num_targets, struct mapped_device *md)
 128 {
 129         struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
 130
 131         if (!t)
 132                 return -ENOMEM;
 133
 134         INIT_LIST_HEAD(&t->devices);
 135
 136         if (!num_targets)
 137                 num_targets = KEYS_PER_NODE;
 138
 139         num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
 140
 141         if (!num_targets) {
 142                 kfree(t);
 143                 return -ENOMEM;
 144         }
 145
 146         if (alloc_targets(t, num_targets)) {
 147                 kfree(t);
 148                 return -ENOMEM;
 149         }
 150
 151         t->type = DM_TYPE_NONE;
 152         t->mode = mode;
 153         t->md = md;
 154         *result = t;
 155         return 0;
 156 }
 157
 158 static void free_devices(struct list_head *devices, struct mapped_device *md)
 159 {
 160         struct list_head *tmp, *next;
 161
 162         list_for_each_safe(tmp, next, devices) {
 163                 struct dm_dev_internal *dd =
 164                     list_entry(tmp, struct dm_dev_internal, list);
 165                 DMWARN("%s: dm_table_destroy: dm_put_device call missing for %s",
 166                        dm_device_name(md), dd->dm_dev->name);
 167                 dm_put_table_device(md, dd->dm_dev);
 168                 kfree(dd);
 169         }
 170 }
 171
 172 static void dm_table_destroy_keyslot_manager(struct dm_table *t);
 173
 174 void dm_table_destroy(struct dm_table *t)
 175 {
 176         unsigned int i;
 177
 178         if (!t)
 179                 return;
 180
 181         /* free the indexes */
 182         if (t->depth >= 2)
 183                 kvfree(t->index[t->depth - 2]);
 184
 185         /* free the targets */
 186         for (i = 0; i < t->num_targets; i++) {
 187                 struct dm_target *tgt = t->targets + i;
 188
 189                 if (tgt->type->dtr)
 190                         tgt->type->dtr(tgt);
 191
 192                 dm_put_target_type(tgt->type);
 193         }
 194
 195         kvfree(t->highs);
 196
 197         /* free the device list */
 198         free_devices(&t->devices, t->md);
 199
 200         dm_free_md_mempools(t->mempools);
 201
 202         dm_table_destroy_keyslot_manager(t);
 203
 204         kfree(t);
 205 }
 206
 207 /*
 208  * See if we've already got a device in the list.
 209  */
 210 static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
 211 {
 212         struct dm_dev_internal *dd;
 213
 214         list_for_each_entry (dd, l, list)
 215                 if (dd->dm_dev->bdev->bd_dev == dev)
 216                         return dd;
 217
 218         return NULL;
 219 }
 220
 221 /*
 222  * If possible, this checks an area of a destination device is invalid.
 223  */
 224 static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
 225                                   sector_t start, sector_t len, void *data)
 226 {
 227         struct queue_limits *limits = data;
 228         struct block_device *bdev = dev->bdev;
 229         sector_t dev_size =
 230                 i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
 231         unsigned short logical_block_size_sectors =
 232                 limits->logical_block_size >> SECTOR_SHIFT;
 233         char b[BDEVNAME_SIZE];
 234
 235         if (!dev_size)
 236                 return 0;
 237
 238         if ((start >= dev_size) || (start + len > dev_size)) {
 239                 DMWARN("%s: %s too small for target: "
 240                        "start=%llu, len=%llu, dev_size=%llu",
 241                        dm_device_name(ti->table->md), bdevname(bdev, b),
 242                        (unsigned long long)start,
 243                        (unsigned long long)len,
 244                        (unsigned long long)dev_size);
 245                 return 1;
 246         }
 247
 248         /*
 249          * If the target is mapped to zoned block device(s), check
 250          * that the zones are not partially mapped.
 251          */
 252         if (bdev_is_zoned(bdev)) {
 253                 unsigned int zone_sectors = bdev_zone_sectors(bdev);
 254
 255                 if (start & (zone_sectors - 1)) {
 256                         DMWARN("%s: start=%llu not aligned to h/w zone size %u of %s",
 257                                dm_device_name(ti->table->md),
 258                                (unsigned long long)start,
 259                                zone_sectors, bdevname(bdev, b));
 260                         return 1;
 261                 }
 262
 263                 /*
 264                  * Note: The last zone of a zoned block device may be smaller
 265                  * than other zones. So for a target mapping the end of a
 266                  * zoned block device with such a zone, len would not be zone
 267                  * aligned. We do not allow such last smaller zone to be part
 268                  * of the mapping here to ensure that mappings with multiple
 269                  * devices do not end up with a smaller zone in the middle of
 270                  * the sector range.
 271                  */
 272                 if (len & (zone_sectors - 1)) {
 273                         DMWARN("%s: len=%llu not aligned to h/w zone size %u of %s",
 274                                dm_device_name(ti->table->md),
 275                                (unsigned long long)len,
 276                                zone_sectors, bdevname(bdev, b));
 277                         return 1;
 278                 }
 279         }
 280
 281         if (logical_block_size_sectors <= 1)
 282                 return 0;
 283
 284         if (start & (logical_block_size_sectors - 1)) {
 285                 DMWARN("%s: start=%llu not aligned to h/w "
 286                        "logical block size %u of %s",
 287                        dm_device_name(ti->table->md),
 288                        (unsigned long long)start,
 289                        limits->logical_block_size, bdevname(bdev, b));
 290                 return 1;
 291         }
 292
 293         if (len & (logical_block_size_sectors - 1)) {
 294                 DMWARN("%s: len=%llu not aligned to h/w "
 295                        "logical block size %u of %s",
 296                        dm_device_name(ti->table->md),
 297                        (unsigned long long)len,
 298                        limits->logical_block_size, bdevname(bdev, b));
 299                 return 1;
 300         }
 301
 302         return 0;
 303 }
 304
 305 /*
 306  * This upgrades the mode on an already open dm_dev, being
 307  * careful to leave things as they were if we fail to reopen the
 308  * device and not to touch the existing bdev field in case
 309  * it is accessed concurrently.
 310  */
 311 static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
 312                         struct mapped_device *md)
 313 {
 314         int r;
 315         struct dm_dev *old_dev, *new_dev;
 316
 317         old_dev = dd->dm_dev;
 318
 319         r = dm_get_table_device(md, dd->dm_dev->bdev->bd_dev,
 320                                 dd->dm_dev->mode | new_mode, &new_dev);
 321         if (r)
 322                 return r;
 323
 324         dd->dm_dev = new_dev;
 325         dm_put_table_device(md, old_dev);
 326
 327         return 0;
 328 }
 329
 330 /*
 331  * Convert the path to a device
 332  */
 333 dev_t dm_get_dev_t(const char *path)
 334 {
 335         dev_t dev;
 336
 337         if (lookup_bdev(path, &dev))
 338                 dev = name_to_dev_t(path);
 339         return dev;
 340 }
 341 EXPORT_SYMBOL_GPL(dm_get_dev_t);
 342
 343 /*
 344  * Add a device to the list, or just increment the usage count if
 345  * it's already present.
 346  */
 347 int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
 348                   struct dm_dev **result)
 349 {
 350         int r;
 351         dev_t dev;
 352         unsigned int major, minor;
 353         char dummy;
 354         struct dm_dev_internal *dd;
 355         struct dm_table *t = ti->table;
 356
 357         BUG_ON(!t);
 358
 359         if (sscanf(path, "%u:%u%c", &major, &minor, &dummy) == 2) {
 360                 /* Extract the major/minor numbers */
 361                 dev = MKDEV(major, minor);
 362                 if (MAJOR(dev) != major || MINOR(dev) != minor)
 363                         return -EOVERFLOW;
 364         } else {
 365                 dev = dm_get_dev_t(path);
 366                 if (!dev)
 367                         return -ENODEV;
 368         }
 369
 370         dd = find_device(&t->devices, dev);
 371         if (!dd) {
 372                 dd = kmalloc(sizeof(*dd), GFP_KERNEL);
 373                 if (!dd)
 374                         return -ENOMEM;
 375
 376                 if ((r = dm_get_table_device(t->md, dev, mode, &dd->dm_dev))) {
 377                         kfree(dd);
 378                         return r;
 379                 }
 380
 381                 refcount_set(&dd->count, 1);
 382                 list_add(&dd->list, &t->devices);
 383                 goto out;
 384
 385         } else if (dd->dm_dev->mode != (mode | dd->dm_dev->mode)) {
 386                 r = upgrade_mode(dd, mode, t->md);
 387                 if (r)
 388                         return r;
 389         }
 390         refcount_inc(&dd->count);
 391 out:
 392         *result = dd->dm_dev;
 393         return 0;
 394 }
 395 EXPORT_SYMBOL(dm_get_device);
 396
 397 static int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
 398                                 sector_t start, sector_t len, void *data)
 399 {
 400         struct queue_limits *limits = data;
 401         struct block_device *bdev = dev->bdev;
 402         struct request_queue *q = bdev_get_queue(bdev);
 403         char b[BDEVNAME_SIZE];
 404
 405         if (unlikely(!q)) {
 406                 DMWARN("%s: Cannot set limits for nonexistent device %s",
 407                        dm_device_name(ti->table->md), bdevname(bdev, b));
 408                 return 0;
 409         }
 410
 411         if (blk_stack_limits(limits, &q->limits,
 412                         get_start_sect(bdev) + start) < 0)
 413                 DMWARN("%s: adding target device %s caused an alignment inconsistency: "
 414                        "physical_block_size=%u, logical_block_size=%u, "
 415                        "alignment_offset=%u, start=%llu",
 416                        dm_device_name(ti->table->md), bdevname(bdev, b),
 417                        q->limits.physical_block_size,
 418                        q->limits.logical_block_size,
 419                        q->limits.alignment_offset,
 420                        (unsigned long long) start << SECTOR_SHIFT);
 421         return 0;
 422 }
 423
 424 /*
 425  * Decrement a device's use count and remove it if necessary.
 426  */
 427 void dm_put_device(struct dm_target *ti, struct dm_dev *d)
 428 {
 429         int found = 0;
 430         struct list_head *devices = &ti->table->devices;
 431         struct dm_dev_internal *dd;
 432
 433         list_for_each_entry(dd, devices, list) {
 434                 if (dd->dm_dev == d) {
 435                         found = 1;
 436                         break;
 437                 }
 438         }
 439         if (!found) {
 440                 DMWARN("%s: device %s not in table devices list",
 441                        dm_device_name(ti->table->md), d->name);
 442                 return;
 443         }
 444         if (refcount_dec_and_test(&dd->count)) {
 445                 dm_put_table_device(ti->table->md, d);
 446                 list_del(&dd->list);
 447                 kfree(dd);
 448         }
 449 }
 450 EXPORT_SYMBOL(dm_put_device);
 451
 452 /*
 453  * Checks to see if the target joins onto the end of the table.
 454  */
 455 static int adjoin(struct dm_table *table, struct dm_target *ti)
 456 {
 457         struct dm_target *prev;
 458
 459         if (!table->num_targets)
 460                 return !ti->begin;
 461
 462         prev = &table->targets[table->num_targets - 1];
 463         return (ti->begin == (prev->begin + prev->len));
 464 }
 465
 466 /*
 467  * Used to dynamically allocate the arg array.
 468  *
 469  * We do first allocation with GFP_NOIO because dm-mpath and dm-thin must
 470  * process messages even if some device is suspended. These messages have a
 471  * small fixed number of arguments.
 472  *
 473  * On the other hand, dm-switch needs to process bulk data using messages and
 474  * excessive use of GFP_NOIO could cause trouble.
 475  */
 476 static char **realloc_argv(unsigned *size, char **old_argv)
 477 {
 478         char **argv;
 479         unsigned new_size;
 480         gfp_t gfp;
 481
 482         if (*size) {
 483                 new_size = *size * 2;
 484                 gfp = GFP_KERNEL;
 485         } else {
 486                 new_size = 8;
 487                 gfp = GFP_NOIO;
 488         }
 489         argv = kmalloc_array(new_size, sizeof(*argv), gfp);
 490         if (argv && old_argv) {
 491                 memcpy(argv, old_argv, *size * sizeof(*argv));
 492                 *size = new_size;
 493         }
 494
 495         kfree(old_argv);
 496         return argv;
 497 }
 498
 499 /*
 500  * Destructively splits up the argument list to pass to ctr.
 501  */
 502 int dm_split_args(int *argc, char ***argvp, char *input)
 503 {
 504         char *start, *end = input, *out, **argv = NULL;
 505         unsigned array_size = 0;
 506
 507         *argc = 0;
 508
 509         if (!input) {
 510                 *argvp = NULL;
 511                 return 0;
 512         }
 513
 514         argv = realloc_argv(&array_size, argv);
 515         if (!argv)
 516                 return -ENOMEM;
 517
 518         while (1) {
 519                 /* Skip whitespace */
 520                 start = skip_spaces(end);
 521
 522                 if (!*start)
 523                         break;  /* success, we hit the end */
 524
 525                 /* 'out' is used to remove any back-quotes */
 526                 end = out = start;
 527                 while (*end) {
 528                         /* Everything apart from '\0' can be quoted */
 529                         if (*end == '\\' && *(end + 1)) {
 530                                 *out++ = *(end + 1);
 531                                 end += 2;
 532                                 continue;
 533                         }
 534
 535                         if (isspace(*end))
 536                                 break;  /* end of token */
 537
 538                         *out++ = *end++;
 539                 }
 540
 541                 /* have we already filled the array ? */
 542                 if ((*argc + 1) > array_size) {
 543                         argv = realloc_argv(&array_size, argv);
 544                         if (!argv)
 545                                 return -ENOMEM;
 546                 }
 547
 548                 /* we know this is whitespace */
 549                 if (*end)
 550                         end++;
 551
 552                 /* terminate the string and put it in the array */
 553                 *out = '\0';
 554                 argv[*argc] = start;
 555                 (*argc)++;
 556         }
 557
 558         *argvp = argv;
 559         return 0;
 560 }
 561
 562 /*
 563  * Impose necessary and sufficient conditions on a devices's table such
 564  * that any incoming bio which respects its logical_block_size can be
 565  * processed successfully.  If it falls across the boundary between
 566  * two or more targets, the size of each piece it gets split into must
 567  * be compatible with the logical_block_size of the target processing it.
 568  */
 569 static int validate_hardware_logical_block_alignment(struct dm_table *table,
 570                                                  struct queue_limits *limits)
 571 {
 572         /*
 573          * This function uses arithmetic modulo the logical_block_size
 574          * (in units of 512-byte sectors).
 575          */
 576         unsigned short device_logical_block_size_sects =
 577                 limits->logical_block_size >> SECTOR_SHIFT;
 578
 579         /*
 580          * Offset of the start of the next table entry, mod logical_block_size.
 581          */
 582         unsigned short next_target_start = 0;
 583
 584         /*
 585          * Given an aligned bio that extends beyond the end of a
 586          * target, how many sectors must the next target handle?
 587          */
 588         unsigned short remaining = 0;
 589
 590         struct dm_target *ti;
 591         struct queue_limits ti_limits;
 592         unsigned i;
 593
 594         /*
 595          * Check each entry in the table in turn.
 596          */
 597         for (i = 0; i < dm_table_get_num_targets(table); i++) {
 598                 ti = dm_table_get_target(table, i);
 599
 600                 blk_set_stacking_limits(&ti_limits);
 601
 602                 /* combine all target devices' limits */
 603                 if (ti->type->iterate_devices)
 604                         ti->type->iterate_devices(ti, dm_set_device_limits,
 605                                                   &ti_limits);
 606
 607                 /*
 608                  * If the remaining sectors fall entirely within this
 609                  * table entry are they compatible with its logical_block_size?
 610                  */
 611                 if (remaining < ti->len &&
 612                     remaining & ((ti_limits.logical_block_size >>
 613                                   SECTOR_SHIFT) - 1))
 614                         break;  /* Error */
 615
 616                 next_target_start =
 617                     (unsigned short) ((next_target_start + ti->len) &
 618                                       (device_logical_block_size_sects - 1));
 619                 remaining = next_target_start ?
 620                     device_logical_block_size_sects - next_target_start : 0;
 621         }
 622
 623         if (remaining) {
 624                 DMWARN("%s: table line %u (start sect %llu len %llu) "
 625                        "not aligned to h/w logical block size %u",
 626                        dm_device_name(table->md), i,
 627                        (unsigned long long) ti->begin,
 628                        (unsigned long long) ti->len,
 629                        limits->logical_block_size);
 630                 return -EINVAL;
 631         }
 632
 633         return 0;
 634 }
 635
 636 int dm_table_add_target(struct dm_table *t, const char *type,
 637                         sector_t start, sector_t len, char *params)
 638 {
 639         int r = -EINVAL, argc;
 640         char **argv;
 641         struct dm_target *tgt;
 642
 643         if (t->singleton) {
 644                 DMERR("%s: target type %s must appear alone in table",
 645                       dm_device_name(t->md), t->targets->type->name);
 646                 return -EINVAL;
 647         }
 648
 649         BUG_ON(t->num_targets >= t->num_allocated);
 650
 651         tgt = t->targets + t->num_targets;
 652         memset(tgt, 0, sizeof(*tgt));
 653
 654         if (!len) {
 655                 DMERR("%s: zero-length target", dm_device_name(t->md));
 656                 return -EINVAL;
 657         }
 658
 659         tgt->type = dm_get_target_type(type);
 660         if (!tgt->type) {
 661                 DMERR("%s: %s: unknown target type", dm_device_name(t->md), type);
 662                 return -EINVAL;
 663         }
 664
 665         if (dm_target_needs_singleton(tgt->type)) {
 666                 if (t->num_targets) {
 667                         tgt->error = "singleton target type must appear alone in table";
 668                         goto bad;
 669                 }
 670                 t->singleton = true;
 671         }
 672
 673         if (dm_target_always_writeable(tgt->type) && !(t->mode & FMODE_WRITE)) {
 674                 tgt->error = "target type may not be included in a read-only table";
 675                 goto bad;
 676         }
 677
 678         if (t->immutable_target_type) {
 679                 if (t->immutable_target_type != tgt->type) {
 680                         tgt->error = "immutable target type cannot be mixed with other target types";
 681                         goto bad;
 682                 }
 683         } else if (dm_target_is_immutable(tgt->type)) {
 684                 if (t->num_targets) {
 685                         tgt->error = "immutable target type cannot be mixed with other target types";
 686                         goto bad;
 687                 }
 688                 t->immutable_target_type = tgt->type;
 689         }
 690
 691         if (dm_target_has_integrity(tgt->type))
 692                 t->integrity_added = 1;
 693
 694         tgt->table = t;
 695         tgt->begin = start;
 696         tgt->len = len;
 697         tgt->error = "Unknown error";
 698
 699         /*
 700          * Does this target adjoin the previous one ?
 701          */
 702         if (!adjoin(t, tgt)) {
 703                 tgt->error = "Gap in table";
 704                 goto bad;
 705         }
 706
 707         r = dm_split_args(&argc, &argv, params);
 708         if (r) {
 709                 tgt->error = "couldn't split parameters (insufficient memory)";
 710                 goto bad;
 711         }
 712
 713         r = tgt->type->ctr(tgt, argc, argv);
 714         kfree(argv);
 715         if (r)
 716                 goto bad;
 717
 718         t->highs[t->num_targets++] = tgt->begin + tgt->len - 1;
 719
 720         if (!tgt->num_discard_bios && tgt->discards_supported)
 721                 DMWARN("%s: %s: ignoring discards_supported because num_discard_bios is zero.",
 722                        dm_device_name(t->md), type);
 723
 724         return 0;
 725
 726  bad:
 727         DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error);
 728         dm_put_target_type(tgt->type);
 729         return r;
 730 }
 731
 732 /*
 733  * Target argument parsing helpers.
 734  */
 735 static int validate_next_arg(const struct dm_arg *arg,
 736                              struct dm_arg_set *arg_set,
 737                              unsigned *value, char **error, unsigned grouped)
 738 {
 739         const char *arg_str = dm_shift_arg(arg_set);
 740         char dummy;
 741
 742         if (!arg_str ||
 743             (sscanf(arg_str, "%u%c", value, &dummy) != 1) ||
 744             (*value < arg->min) ||
 745             (*value > arg->max) ||
 746             (grouped && arg_set->argc < *value)) {
 747                 *error = arg->error;
 748                 return -EINVAL;
 749         }
 750
 751         return 0;
 752 }
 753
 754 int dm_read_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
 755                 unsigned *value, char **error)
 756 {
 757         return validate_next_arg(arg, arg_set, value, error, 0);
 758 }
 759 EXPORT_SYMBOL(dm_read_arg);
 760
 761 int dm_read_arg_group(const struct dm_arg *arg, struct dm_arg_set *arg_set,
 762                       unsigned *value, char **error)
 763 {
 764         return validate_next_arg(arg, arg_set, value, error, 1);
 765 }
 766 EXPORT_SYMBOL(dm_read_arg_group);
 767
 768 const char *dm_shift_arg(struct dm_arg_set *as)
 769 {
 770         char *r;
 771
 772         if (as->argc) {
 773                 as->argc--;
 774                 r = *as->argv;
 775                 as->argv++;
 776                 return r;
 777         }
 778
 779         return NULL;
 780 }
 781 EXPORT_SYMBOL(dm_shift_arg);
 782
 783 void dm_consume_args(struct dm_arg_set *as, unsigned num_args)
 784 {
 785         BUG_ON(as->argc < num_args);
 786         as->argc -= num_args;
 787         as->argv += num_args;
 788 }
 789 EXPORT_SYMBOL(dm_consume_args);
 790
 791 static bool __table_type_bio_based(enum dm_queue_mode table_type)
 792 {
 793         return (table_type == DM_TYPE_BIO_BASED ||
 794                 table_type == DM_TYPE_DAX_BIO_BASED);
 795 }
 796
 797 static bool __table_type_request_based(enum dm_queue_mode table_type)
 798 {
 799         return table_type == DM_TYPE_REQUEST_BASED;
 800 }
 801
 802 void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type)
 803 {
 804         t->type = type;
 805 }
 806 EXPORT_SYMBOL_GPL(dm_table_set_type);
 807
 808 /* validate the dax capability of the target device span */
 809 int device_not_dax_capable(struct dm_target *ti, struct dm_dev *dev,
 810                         sector_t start, sector_t len, void *data)
 811 {
 812         int blocksize = *(int *) data, id;
 813         bool rc;
 814
 815         id = dax_read_lock();
 816         rc = !dax_supported(dev->dax_dev, dev->bdev, blocksize, start, len);
 817         dax_read_unlock(id);
 818
 819         return rc;
 820 }
 821
 822 /* Check devices support synchronous DAX */
 823 static int device_not_dax_synchronous_capable(struct dm_target *ti, struct dm_dev *dev,
 824                                               sector_t start, sector_t len, void *data)
 825 {
 826         return !dev->dax_dev || !dax_synchronous(dev->dax_dev);
 827 }
 828
 829 bool dm_table_supports_dax(struct dm_table *t,
 830                            iterate_devices_callout_fn iterate_fn, int *blocksize)
 831 {
 832         struct dm_target *ti;
 833         unsigned i;
 834
 835         /* Ensure that all targets support DAX. */
 836         for (i = 0; i < dm_table_get_num_targets(t); i++) {
 837                 ti = dm_table_get_target(t, i);
 838
 839                 if (!ti->type->direct_access)
 840                         return false;
 841
 842                 if (!ti->type->iterate_devices ||
 843                     ti->type->iterate_devices(ti, iterate_fn, blocksize))
 844                         return false;
 845         }
 846
 847         return true;
 848 }
 849
 850 static int device_is_rq_stackable(struct dm_target *ti, struct dm_dev *dev,
 851                                   sector_t start, sector_t len, void *data)
 852 {
 853         struct block_device *bdev = dev->bdev;
 854         struct request_queue *q = bdev_get_queue(bdev);
 855
 856         /* request-based cannot stack on partitions! */
 857         if (bdev_is_partition(bdev))
 858                 return false;
 859
 860         return queue_is_mq(q);
 861 }
 862
 863 static int dm_table_determine_type(struct dm_table *t)
 864 {
 865         unsigned i;
 866         unsigned bio_based = 0, request_based = 0, hybrid = 0;
 867         struct dm_target *tgt;
 868         struct list_head *devices = dm_table_get_devices(t);
 869         enum dm_queue_mode live_md_type = dm_get_md_type(t->md);
 870         int page_size = PAGE_SIZE;
 871
 872         if (t->type != DM_TYPE_NONE) {
 873                 /* target already set the table's type */
 874                 if (t->type == DM_TYPE_BIO_BASED) {
 875                         /* possibly upgrade to a variant of bio-based */
 876                         goto verify_bio_based;
 877                 }
 878                 BUG_ON(t->type == DM_TYPE_DAX_BIO_BASED);
 879                 goto verify_rq_based;
 880         }
 881
 882         for (i = 0; i < t->num_targets; i++) {
 883                 tgt = t->targets + i;
 884                 if (dm_target_hybrid(tgt))
 885                         hybrid = 1;
 886                 else if (dm_target_request_based(tgt))
 887                         request_based = 1;
 888                 else
 889                         bio_based = 1;
 890
 891                 if (bio_based && request_based) {
 892                         DMERR("Inconsistent table: different target types"
 893                               " can't be mixed up");
 894                         return -EINVAL;
 895                 }
 896         }
 897
 898         if (hybrid && !bio_based && !request_based) {
 899                 /*
 900                  * The targets can work either way.
 901                  * Determine the type from the live device.
 902                  * Default to bio-based if device is new.
 903                  */
 904                 if (__table_type_request_based(live_md_type))
 905                         request_based = 1;
 906                 else
 907                         bio_based = 1;
 908         }
 909
 910         if (bio_based) {
 911 verify_bio_based:
 912                 /* We must use this table as bio-based */
 913                 t->type = DM_TYPE_BIO_BASED;
 914                 if (dm_table_supports_dax(t, device_not_dax_capable, &page_size) ||
 915                     (list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED)) {
 916                         t->type = DM_TYPE_DAX_BIO_BASED;
 917                 }
 918                 return 0;
 919         }
 920
 921         BUG_ON(!request_based); /* No targets in this table */
 922
 923         t->type = DM_TYPE_REQUEST_BASED;
 924
 925 verify_rq_based:
 926         /*
 927          * Request-based dm supports only tables that have a single target now.
 928          * To support multiple targets, request splitting support is needed,
 929          * and that needs lots of changes in the block-layer.
 930          * (e.g. request completion process for partial completion.)
 931          */
 932         if (t->num_targets > 1) {
 933                 DMERR("request-based DM doesn't support multiple targets");
 934                 return -EINVAL;
 935         }
 936
 937         if (list_empty(devices)) {
 938                 int srcu_idx;
 939                 struct dm_table *live_table = dm_get_live_table(t->md, &srcu_idx);
 940
 941                 /* inherit live table's type */
 942                 if (live_table)
 943                         t->type = live_table->type;
 944                 dm_put_live_table(t->md, srcu_idx);
 945                 return 0;
 946         }
 947
 948         tgt = dm_table_get_immutable_target(t);
 949         if (!tgt) {
 950                 DMERR("table load rejected: immutable target is required");
 951                 return -EINVAL;
 952         } else if (tgt->max_io_len) {
 953                 DMERR("table load rejected: immutable target that splits IO is not supported");
 954                 return -EINVAL;
 955         }
 956
 957         /* Non-request-stackable devices can't be used for request-based dm */
 958         if (!tgt->type->iterate_devices ||
 959             !tgt->type->iterate_devices(tgt, device_is_rq_stackable, NULL)) {
 960                 DMERR("table load rejected: including non-request-stackable devices");
 961                 return -EINVAL;
 962         }
 963
 964         return 0;
 965 }
 966
 967 enum dm_queue_mode dm_table_get_type(struct dm_table *t)
 968 {
 969         return t->type;
 970 }
 971
 972 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
 973 {
 974         return t->immutable_target_type;
 975 }
 976
 977 struct dm_target *dm_table_get_immutable_target(struct dm_table *t)
 978 {
 979         /* Immutable target is implicitly a singleton */
 980         if (t->num_targets > 1 ||
 981             !dm_target_is_immutable(t->targets[0].type))
 982                 return NULL;
 983
 984         return t->targets;
 985 }
 986
 987 struct dm_target *dm_table_get_wildcard_target(struct dm_table *t)
 988 {
 989         struct dm_target *ti;
 990         unsigned i;
 991
 992         for (i = 0; i < dm_table_get_num_targets(t); i++) {
 993                 ti = dm_table_get_target(t, i);
 994                 if (dm_target_is_wildcard(ti->type))
 995                         return ti;
 996         }
 997
 998         return NULL;
 999 }
1000
1001 bool dm_table_bio_based(struct dm_table *t)
1002 {
1003         return __table_type_bio_based(dm_table_get_type(t));
1004 }
1005
1006 bool dm_table_request_based(struct dm_table *t)
1007 {
1008         return __table_type_request_based(dm_table_get_type(t));
1009 }
1010
1011 static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device *md)
1012 {
1013         enum dm_queue_mode type = dm_table_get_type(t);
1014         unsigned per_io_data_size = 0;
1015         unsigned min_pool_size = 0;
1016         struct dm_target *ti;
1017         unsigned i;
1018
1019         if (unlikely(type == DM_TYPE_NONE)) {
1020                 DMWARN("no table type is set, can't allocate mempools");
1021                 return -EINVAL;
1022         }
1023
1024         if (__table_type_bio_based(type))
1025                 for (i = 0; i < t->num_targets; i++) {
1026                         ti = t->targets + i;
1027                         per_io_data_size = max(per_io_data_size, ti->per_io_data_size);
1028                         min_pool_size = max(min_pool_size, ti->num_flush_bios);
1029                 }
1030
1031         t->mempools = dm_alloc_md_mempools(md, type, t->integrity_supported,
1032                                            per_io_data_size, min_pool_size);
1033         if (!t->mempools)
1034                 return -ENOMEM;
1035
1036         return 0;
1037 }
1038
1039 void dm_table_free_md_mempools(struct dm_table *t)
1040 {
1041         dm_free_md_mempools(t->mempools);
1042         t->mempools = NULL;
1043 }
1044
1045 struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t)
1046 {
1047         return t->mempools;
1048 }
1049
1050 static int setup_indexes(struct dm_table *t)
1051 {
1052         int i;
1053         unsigned int total = 0;
1054         sector_t *indexes;
1055
1056         /* allocate the space for *all* the indexes */
1057         for (i = t->depth - 2; i >= 0; i--) {
1058                 t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
1059                 total += t->counts[i];
1060         }
1061
1062         indexes = kvcalloc(total, NODE_SIZE, GFP_KERNEL);
1063         if (!indexes)
1064                 return -ENOMEM;
1065
1066         /* set up internal nodes, bottom-up */
1067         for (i = t->depth - 2; i >= 0; i--) {
1068                 t->index[i] = indexes;
1069                 indexes += (KEYS_PER_NODE * t->counts[i]);
1070                 setup_btree_index(i, t);
1071         }
1072
1073         return 0;
1074 }
1075
1076 /*
1077  * Builds the btree to index the map.
1078  */
1079 static int dm_table_build_index(struct dm_table *t)
1080 {
1081         int r = 0;
1082         unsigned int leaf_nodes;
1083
1084         /* how many indexes will the btree have ? */
1085         leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
1086         t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
1087
1088         /* leaf layer has already been set up */
1089         t->counts[t->depth - 1] = leaf_nodes;
1090         t->index[t->depth - 1] = t->highs;
1091
1092         if (t->depth >= 2)
1093                 r = setup_indexes(t);
1094
1095         return r;
1096 }
1097
1098 static bool integrity_profile_exists(struct gendisk *disk)
1099 {
1100         return !!blk_get_integrity(disk);
1101 }
1102
1103 /*
1104  * Get a disk whose integrity profile reflects the table's profile.
1105  * Returns NULL if integrity support was inconsistent or unavailable.
1106  */
1107 static struct gendisk * dm_table_get_integrity_disk(struct dm_table *t)
1108 {
1109         struct list_head *devices = dm_table_get_devices(t);
1110         struct dm_dev_internal *dd = NULL;
1111         struct gendisk *prev_disk = NULL, *template_disk = NULL;
1112         unsigned i;
1113
1114         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1115                 struct dm_target *ti = dm_table_get_target(t, i);
1116                 if (!dm_target_passes_integrity(ti->type))
1117                         goto no_integrity;
1118         }
1119
1120         list_for_each_entry(dd, devices, list) {
1121                 template_disk = dd->dm_dev->bdev->bd_disk;
1122                 if (!integrity_profile_exists(template_disk))
1123                         goto no_integrity;
1124                 else if (prev_disk &&
1125                          blk_integrity_compare(prev_disk, template_disk) < 0)
1126                         goto no_integrity;
1127                 prev_disk = template_disk;
1128         }
1129
1130         return template_disk;
1131
1132 no_integrity:
1133         if (prev_disk)
1134                 DMWARN("%s: integrity not set: %s and %s profile mismatch",
1135                        dm_device_name(t->md),
1136                        prev_disk->disk_name,
1137                        template_disk->disk_name);
1138         return NULL;
1139 }
1140
1141 /*
1142  * Register the mapped device for blk_integrity support if the
1143  * underlying devices have an integrity profile.  But all devices may
1144  * not have matching profiles (checking all devices isn't reliable
1145  * during table load because this table may use other DM device(s) which
1146  * must be resumed before they will have an initialized integity
1147  * profile).  Consequently, stacked DM devices force a 2 stage integrity
1148  * profile validation: First pass during table load, final pass during
1149  * resume.
1150  */
1151 static int dm_table_register_integrity(struct dm_table *t)
1152 {
1153         struct mapped_device *md = t->md;
1154         struct gendisk *template_disk = NULL;
1155
1156         /* If target handles integrity itself do not register it here. */
1157         if (t->integrity_added)
1158                 return 0;
1159
1160         template_disk = dm_table_get_integrity_disk(t);
1161         if (!template_disk)
1162                 return 0;
1163
1164         if (!integrity_profile_exists(dm_disk(md))) {
1165                 t->integrity_supported = true;
1166                 /*
1167                  * Register integrity profile during table load; we can do
1168                  * this because the final profile must match during resume.
1169                  */
1170                 blk_integrity_register(dm_disk(md),
1171                                        blk_get_integrity(template_disk));
1172                 return 0;
1173         }
1174
1175         /*
1176          * If DM device already has an initialized integrity
1177          * profile the new profile should not conflict.
1178          */
1179         if (blk_integrity_compare(dm_disk(md), template_disk) < 0) {
1180                 DMWARN("%s: conflict with existing integrity profile: "
1181                        "%s profile mismatch",
1182                        dm_device_name(t->md),
1183                        template_disk->disk_name);
1184                 return 1;
1185         }
1186
1187         /* Preserve existing integrity profile */
1188         t->integrity_supported = true;
1189         return 0;
1190 }
1191
1192 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
1193
1194 struct dm_keyslot_manager {
1195         struct blk_keyslot_manager ksm;
1196         struct mapped_device *md;
1197 };
1198
1199 struct dm_keyslot_evict_args {
1200         const struct blk_crypto_key *key;
1201         int err;
1202 };
1203
1204 static int dm_keyslot_evict_callback(struct dm_target *ti, struct dm_dev *dev,
1205                                      sector_t start, sector_t len, void *data)
1206 {
1207         struct dm_keyslot_evict_args *args = data;
1208         int err;
1209
1210         err = blk_crypto_evict_key(bdev_get_queue(dev->bdev), args->key);
1211         if (!args->err)
1212                 args->err = err;
1213         /* Always try to evict the key from all devices. */
1214         return 0;
1215 }
1216
1217 /*
1218  * When an inline encryption key is evicted from a device-mapper device, evict
1219  * it from all the underlying devices.
1220  */
1221 static int dm_keyslot_evict(struct blk_keyslot_manager *ksm,
1222                             const struct blk_crypto_key *key, unsigned int slot)
1223 {
1224         struct dm_keyslot_manager *dksm = container_of(ksm,
1225                                                        struct dm_keyslot_manager,
1226                                                        ksm);
1227         struct mapped_device *md = dksm->md;
1228         struct dm_keyslot_evict_args args = { key };
1229         struct dm_table *t;
1230         int srcu_idx;
1231         int i;
1232         struct dm_target *ti;
1233
1234         t = dm_get_live_table(md, &srcu_idx);
1235         if (!t)
1236                 return 0;
1237         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1238                 ti = dm_table_get_target(t, i);
1239                 if (!ti->type->iterate_devices)
1240                         continue;
1241                 ti->type->iterate_devices(ti, dm_keyslot_evict_callback, &args);
1242         }
1243         dm_put_live_table(md, srcu_idx);
1244         return args.err;
1245 }
1246
1247 static const struct blk_ksm_ll_ops dm_ksm_ll_ops = {
1248         .keyslot_evict = dm_keyslot_evict,
1249 };
1250
1251 static int device_intersect_crypto_modes(struct dm_target *ti,
1252                                          struct dm_dev *dev, sector_t start,
1253                                          sector_t len, void *data)
1254 {
1255         struct blk_keyslot_manager *parent = data;
1256         struct blk_keyslot_manager *child = bdev_get_queue(dev->bdev)->ksm;
1257
1258         blk_ksm_intersect_modes(parent, child);
1259         return 0;
1260 }
1261
1262 void dm_destroy_keyslot_manager(struct blk_keyslot_manager *ksm)
1263 {
1264         struct dm_keyslot_manager *dksm = container_of(ksm,
1265                                                        struct dm_keyslot_manager,
1266                                                        ksm);
1267
1268         if (!ksm)
1269                 return;
1270
1271         blk_ksm_destroy(ksm);
1272         kfree(dksm);
1273 }
1274
1275 static void dm_table_destroy_keyslot_manager(struct dm_table *t)
1276 {
1277         dm_destroy_keyslot_manager(t->ksm);
1278         t->ksm = NULL;
1279 }
1280
1281 /*
1282  * Constructs and initializes t->ksm with a keyslot manager that
1283  * represents the common set of crypto capabilities of the devices
1284  * described by the dm_table. However, if the constructed keyslot
1285  * manager does not support a superset of the crypto capabilities
1286  * supported by the current keyslot manager of the mapped_device,
1287  * it returns an error instead, since we don't support restricting
1288  * crypto capabilities on table changes. Finally, if the constructed
1289  * keyslot manager doesn't actually support any crypto modes at all,
1290  * it just returns NULL.
1291  */
1292 static int dm_table_construct_keyslot_manager(struct dm_table *t)
1293 {
1294         struct dm_keyslot_manager *dksm;
1295         struct blk_keyslot_manager *ksm;
1296         struct dm_target *ti;
1297         unsigned int i;
1298         bool ksm_is_empty = true;
1299
1300         dksm = kmalloc(sizeof(*dksm), GFP_KERNEL);
1301         if (!dksm)
1302                 return -ENOMEM;
1303         dksm->md = t->md;
1304
1305         ksm = &dksm->ksm;
1306         blk_ksm_init_passthrough(ksm);
1307         ksm->ksm_ll_ops = dm_ksm_ll_ops;
1308         ksm->max_dun_bytes_supported = UINT_MAX;
1309         memset(ksm->crypto_modes_supported, 0xFF,
1310                sizeof(ksm->crypto_modes_supported));
1311
1312         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1313                 ti = dm_table_get_target(t, i);
1314
1315                 if (!dm_target_passes_crypto(ti->type)) {
1316                         blk_ksm_intersect_modes(ksm, NULL);
1317                         break;
1318                 }
1319                 if (!ti->type->iterate_devices)
1320                         continue;
1321                 ti->type->iterate_devices(ti, device_intersect_crypto_modes,
1322                                           ksm);
1323         }
1324
1325         if (t->md->queue && !blk_ksm_is_superset(ksm, t->md->queue->ksm)) {
1326                 DMWARN("Inline encryption capabilities of new DM table were more restrictive than the old table's. This is not supported!");
1327                 dm_destroy_keyslot_manager(ksm);
1328                 return -EINVAL;
1329         }
1330
1331         /*
1332          * If the new KSM doesn't actually support any crypto modes, we may as
1333          * well represent it with a NULL ksm.
1334          */
1335         ksm_is_empty = true;
1336         for (i = 0; i < ARRAY_SIZE(ksm->crypto_modes_supported); i++) {
1337                 if (ksm->crypto_modes_supported[i]) {
1338                         ksm_is_empty = false;
1339                         break;
1340                 }
1341         }
1342
1343         if (ksm_is_empty) {
1344                 dm_destroy_keyslot_manager(ksm);
1345                 ksm = NULL;
1346         }
1347
1348         /*
1349          * t->ksm is only set temporarily while the table is being set
1350          * up, and it gets set to NULL after the capabilities have
1351          * been transferred to the request_queue.
1352          */
1353         t->ksm = ksm;
1354
1355         return 0;
1356 }
1357
1358 static void dm_update_keyslot_manager(struct request_queue *q,
1359                                       struct dm_table *t)
1360 {
1361         if (!t->ksm)
1362                 return;
1363
1364         /* Make the ksm less restrictive */
1365         if (!q->ksm) {
1366                 blk_ksm_register(t->ksm, q);
1367         } else {
1368                 blk_ksm_update_capabilities(q->ksm, t->ksm);
1369                 dm_destroy_keyslot_manager(t->ksm);
1370         }
1371         t->ksm = NULL;
1372 }
1373
1374 #else /* CONFIG_BLK_INLINE_ENCRYPTION */
1375
1376 static int dm_table_construct_keyslot_manager(struct dm_table *t)
1377 {
1378         return 0;
1379 }
1380
1381 void dm_destroy_keyslot_manager(struct blk_keyslot_manager *ksm)
1382 {
1383 }
1384
1385 static void dm_table_destroy_keyslot_manager(struct dm_table *t)
1386 {
1387 }
1388
1389 static void dm_update_keyslot_manager(struct request_queue *q,
1390                                       struct dm_table *t)
1391 {
1392 }
1393
1394 #endif /* !CONFIG_BLK_INLINE_ENCRYPTION */
1395
1396 /*
1397  * Prepares the table for use by building the indices,
1398  * setting the type, and allocating mempools.
1399  */
1400 int dm_table_complete(struct dm_table *t)
1401 {
1402         int r;
1403
1404         r = dm_table_determine_type(t);
1405         if (r) {
1406                 DMERR("unable to determine table type");
1407                 return r;
1408         }
1409
1410         r = dm_table_build_index(t);
1411         if (r) {
1412                 DMERR("unable to build btrees");
1413                 return r;
1414         }
1415
1416         r = dm_table_register_integrity(t);
1417         if (r) {
1418                 DMERR("could not register integrity profile.");
1419                 return r;
1420         }
1421
1422         r = dm_table_construct_keyslot_manager(t);
1423         if (r) {
1424                 DMERR("could not construct keyslot manager.");
1425                 return r;
1426         }
1427
1428         r = dm_table_alloc_md_mempools(t, t->md);
1429         if (r)
1430                 DMERR("unable to allocate mempools");
1431
1432         return r;
1433 }
1434
1435 static DEFINE_MUTEX(_event_lock);
1436 void dm_table_event_callback(struct dm_table *t,
1437                              void (*fn)(void *), void *context)
1438 {
1439         mutex_lock(&_event_lock);
1440         t->event_fn = fn;
1441         t->event_context = context;
1442         mutex_unlock(&_event_lock);
1443 }
1444
1445 void dm_table_event(struct dm_table *t)
1446 {
1447         mutex_lock(&_event_lock);
1448         if (t->event_fn)
1449                 t->event_fn(t->event_context);
1450         mutex_unlock(&_event_lock);
1451 }
1452 EXPORT_SYMBOL(dm_table_event);
1453
1454 inline sector_t dm_table_get_size(struct dm_table *t)
1455 {
1456         return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1457 }
1458 EXPORT_SYMBOL(dm_table_get_size);
1459
1460 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index)
1461 {
1462         if (index >= t->num_targets)
1463                 return NULL;
1464
1465         return t->targets + index;
1466 }
1467
1468 /*
1469  * Search the btree for the correct target.
1470  *
1471  * Caller should check returned pointer for NULL
1472  * to trap I/O beyond end of device.
1473  */
1474 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1475 {
1476         unsigned int l, n = 0, k = 0;
1477         sector_t *node;
1478
1479         if (unlikely(sector >= dm_table_get_size(t)))
1480                 return NULL;
1481
1482         for (l = 0; l < t->depth; l++) {
1483                 n = get_child(n, k);
1484                 node = get_node(t, l, n);
1485
1486                 for (k = 0; k < KEYS_PER_NODE; k++)
1487                         if (node[k] >= sector)
1488                                 break;
1489         }
1490
1491         return &t->targets[(KEYS_PER_NODE * n) + k];
1492 }
1493
1494 /*
1495  * type->iterate_devices() should be called when the sanity check needs to
1496  * iterate and check all underlying data devices. iterate_devices() will
1497  * iterate all underlying data devices until it encounters a non-zero return
1498  * code, returned by whether the input iterate_devices_callout_fn, or
1499  * iterate_devices() itself internally.
1500  *
1501  * For some target type (e.g. dm-stripe), one call of iterate_devices() may
1502  * iterate multiple underlying devices internally, in which case a non-zero
1503  * return code returned by iterate_devices_callout_fn will stop the iteration
1504  * in advance.
1505  *
1506  * Cases requiring _any_ underlying device supporting some kind of attribute,
1507  * should use the iteration structure like dm_table_any_dev_attr(), or call
1508  * it directly. @func should handle semantics of positive examples, e.g.
1509  * capable of something.
1510  *
1511  * Cases requiring _all_ underlying devices supporting some kind of attribute,
1512  * should use the iteration structure like dm_table_supports_nowait() or
1513  * dm_table_supports_discards(). Or introduce dm_table_all_devs_attr() that
1514  * uses an @anti_func that handle semantics of counter examples, e.g. not
1515  * capable of something. So: return !dm_table_any_dev_attr(t, anti_func, data);
1516  */
1517 static bool dm_table_any_dev_attr(struct dm_table *t,
1518                                   iterate_devices_callout_fn func, void *data)
1519 {
1520         struct dm_target *ti;
1521         unsigned int i;
1522
1523         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1524                 ti = dm_table_get_target(t, i);
1525
1526                 if (ti->type->iterate_devices &&
1527                     ti->type->iterate_devices(ti, func, data))
1528                         return true;
1529         }
1530
1531         return false;
1532 }
1533
1534 static int count_device(struct dm_target *ti, struct dm_dev *dev,
1535                         sector_t start, sector_t len, void *data)
1536 {
1537         unsigned *num_devices = data;
1538
1539         (*num_devices)++;
1540
1541         return 0;
1542 }
1543
1544 /*
1545  * Check whether a table has no data devices attached using each
1546  * target's iterate_devices method.
1547  * Returns false if the result is unknown because a target doesn't
1548  * support iterate_devices.
1549  */
1550 bool dm_table_has_no_data_devices(struct dm_table *table)
1551 {
1552         struct dm_target *ti;
1553         unsigned i, num_devices;
1554
1555         for (i = 0; i < dm_table_get_num_targets(table); i++) {
1556                 ti = dm_table_get_target(table, i);
1557
1558                 if (!ti->type->iterate_devices)
1559                         return false;
1560
1561                 num_devices = 0;
1562                 ti->type->iterate_devices(ti, count_device, &num_devices);
1563                 if (num_devices)
1564                         return false;
1565         }
1566
1567         return true;
1568 }
1569
1570 static int device_not_zoned_model(struct dm_target *ti, struct dm_dev *dev,
1571                                   sector_t start, sector_t len, void *data)
1572 {
1573         struct request_queue *q = bdev_get_queue(dev->bdev);
1574         enum blk_zoned_model *zoned_model = data;
1575
1576         return blk_queue_zoned_model(q) != *zoned_model;
1577 }
1578
1579 /*
1580  * Check the device zoned model based on the target feature flag. If the target
1581  * has the DM_TARGET_ZONED_HM feature flag set, host-managed zoned devices are
1582  * also accepted but all devices must have the same zoned model. If the target
1583  * has the DM_TARGET_MIXED_ZONED_MODEL feature set, the devices can have any
1584  * zoned model with all zoned devices having the same zone size.
1585  */
1586 static bool dm_table_supports_zoned_model(struct dm_table *t,
1587                                           enum blk_zoned_model zoned_model)
1588 {
1589         struct dm_target *ti;
1590         unsigned i;
1591
1592         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1593                 ti = dm_table_get_target(t, i);
1594
1595                 if (dm_target_supports_zoned_hm(ti->type)) {
1596                         if (!ti->type->iterate_devices ||
1597                             ti->type->iterate_devices(ti, device_not_zoned_model,
1598                                                       &zoned_model))
1599                                 return false;
1600                 } else if (!dm_target_supports_mixed_zoned_model(ti->type)) {
1601                         if (zoned_model == BLK_ZONED_HM)
1602                                 return false;
1603                 }
1604         }
1605
1606         return true;
1607 }
1608
1609 static int device_not_matches_zone_sectors(struct dm_target *ti, struct dm_dev *dev,
1610                                            sector_t start, sector_t len, void *data)
1611 {
1612         struct request_queue *q = bdev_get_queue(dev->bdev);
1613         unsigned int *zone_sectors = data;
1614
1615         if (!blk_queue_is_zoned(q))
1616                 return 0;
1617
1618         return blk_queue_zone_sectors(q) != *zone_sectors;
1619 }
1620
1621 /*
1622  * Check consistency of zoned model and zone sectors across all targets. For
1623  * zone sectors, if the destination device is a zoned block device, it shall
1624  * have the specified zone_sectors.
1625  */
1626 static int validate_hardware_zoned_model(struct dm_table *table,
1627                                          enum blk_zoned_model zoned_model,
1628                                          unsigned int zone_sectors)
1629 {
1630         if (zoned_model == BLK_ZONED_NONE)
1631                 return 0;
1632
1633         if (!dm_table_supports_zoned_model(table, zoned_model)) {
1634                 DMERR("%s: zoned model is not consistent across all devices",
1635                       dm_device_name(table->md));
1636                 return -EINVAL;
1637         }
1638
1639         /* Check zone size validity and compatibility */
1640         if (!zone_sectors || !is_power_of_2(zone_sectors))
1641                 return -EINVAL;
1642
1643         if (dm_table_any_dev_attr(table, device_not_matches_zone_sectors, &zone_sectors)) {
1644                 DMERR("%s: zone sectors is not consistent across all zoned devices",
1645                       dm_device_name(table->md));
1646                 return -EINVAL;
1647         }
1648
1649         return 0;
1650 }
1651
1652 /*
1653  * Establish the new table's queue_limits and validate them.
1654  */
1655 int dm_calculate_queue_limits(struct dm_table *table,
1656                               struct queue_limits *limits)
1657 {
1658         struct dm_target *ti;
1659         struct queue_limits ti_limits;
1660         unsigned i;
1661         enum blk_zoned_model zoned_model = BLK_ZONED_NONE;
1662         unsigned int zone_sectors = 0;
1663
1664         blk_set_stacking_limits(limits);
1665
1666         for (i = 0; i < dm_table_get_num_targets(table); i++) {
1667                 blk_set_stacking_limits(&ti_limits);
1668
1669                 ti = dm_table_get_target(table, i);
1670
1671                 if (!ti->type->iterate_devices)
1672                         goto combine_limits;
1673
1674                 /*
1675                  * Combine queue limits of all the devices this target uses.
1676                  */
1677                 ti->type->iterate_devices(ti, dm_set_device_limits,
1678                                           &ti_limits);
1679
1680                 if (zoned_model == BLK_ZONED_NONE && ti_limits.zoned != BLK_ZONED_NONE) {
1681                         /*
1682                          * After stacking all limits, validate all devices
1683                          * in table support this zoned model and zone sectors.
1684                          */
1685                         zoned_model = ti_limits.zoned;
1686                         zone_sectors = ti_limits.chunk_sectors;
1687                 }
1688
1689                 /* Set I/O hints portion of queue limits */
1690                 if (ti->type->io_hints)
1691                         ti->type->io_hints(ti, &ti_limits);
1692
1693                 /*
1694                  * Check each device area is consistent with the target's
1695                  * overall queue limits.
1696                  */
1697                 if (ti->type->iterate_devices(ti, device_area_is_invalid,
1698                                               &ti_limits))
1699                         return -EINVAL;
1700
1701 combine_limits:
1702                 /*
1703                  * Merge this target's queue limits into the overall limits
1704                  * for the table.
1705                  */
1706                 if (blk_stack_limits(limits, &ti_limits, 0) < 0)
1707                         DMWARN("%s: adding target device "
1708                                "(start sect %llu len %llu) "
1709                                "caused an alignment inconsistency",
1710                                dm_device_name(table->md),
1711                                (unsigned long long) ti->begin,
1712                                (unsigned long long) ti->len);
1713         }
1714
1715         /*
1716          * Verify that the zoned model and zone sectors, as determined before
1717          * any .io_hints override, are the same across all devices in the table.
1718          * - this is especially relevant if .io_hints is emulating a disk-managed
1719          *   zoned model (aka BLK_ZONED_NONE) on host-managed zoned block devices.
1720          * BUT...
1721          */
1722         if (limits->zoned != BLK_ZONED_NONE) {
1723                 /*
1724                  * ...IF the above limits stacking determined a zoned model
1725                  * validate that all of the table's devices conform to it.
1726                  */
1727                 zoned_model = limits->zoned;
1728                 zone_sectors = limits->chunk_sectors;
1729         }
1730         if (validate_hardware_zoned_model(table, zoned_model, zone_sectors))
1731                 return -EINVAL;
1732
1733         return validate_hardware_logical_block_alignment(table, limits);
1734 }
1735
1736 /*
1737  * Verify that all devices have an integrity profile that matches the
1738  * DM device's registered integrity profile.  If the profiles don't
1739  * match then unregister the DM device's integrity profile.
1740  */
1741 static void dm_table_verify_integrity(struct dm_table *t)
1742 {
1743         struct gendisk *template_disk = NULL;
1744
1745         if (t->integrity_added)
1746                 return;
1747
1748         if (t->integrity_supported) {
1749                 /*
1750                  * Verify that the original integrity profile
1751                  * matches all the devices in this table.
1752                  */
1753                 template_disk = dm_table_get_integrity_disk(t);
1754                 if (template_disk &&
1755                     blk_integrity_compare(dm_disk(t->md), template_disk) >= 0)
1756                         return;
1757         }
1758
1759         if (integrity_profile_exists(dm_disk(t->md))) {
1760                 DMWARN("%s: unable to establish an integrity profile",
1761                        dm_device_name(t->md));
1762                 blk_integrity_unregister(dm_disk(t->md));
1763         }
1764 }
1765
1766 static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
1767                                 sector_t start, sector_t len, void *data)
1768 {
1769         unsigned long flush = (unsigned long) data;
1770         struct request_queue *q = bdev_get_queue(dev->bdev);
1771
1772         return (q->queue_flags & flush);
1773 }
1774
1775 static bool dm_table_supports_flush(struct dm_table *t, unsigned long flush)
1776 {
1777         struct dm_target *ti;
1778         unsigned i;
1779
1780         /*
1781          * Require at least one underlying device to support flushes.
1782          * t->devices includes internal dm devices such as mirror logs
1783          * so we need to use iterate_devices here, which targets
1784          * supporting flushes must provide.
1785          */
1786         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1787                 ti = dm_table_get_target(t, i);
1788
1789                 if (!ti->num_flush_bios)
1790                         continue;
1791
1792                 if (ti->flush_supported)
1793                         return true;
1794
1795                 if (ti->type->iterate_devices &&
1796                     ti->type->iterate_devices(ti, device_flush_capable, (void *) flush))
1797                         return true;
1798         }
1799
1800         return false;
1801 }
1802
1803 static int device_dax_write_cache_enabled(struct dm_target *ti,
1804                                           struct dm_dev *dev, sector_t start,
1805                                           sector_t len, void *data)
1806 {
1807         struct dax_device *dax_dev = dev->dax_dev;
1808
1809         if (!dax_dev)
1810                 return false;
1811
1812         if (dax_write_cache_enabled(dax_dev))
1813                 return true;
1814         return false;
1815 }
1816
1817 static int device_is_rotational(struct dm_target *ti, struct dm_dev *dev,
1818                                 sector_t start, sector_t len, void *data)
1819 {
1820         struct request_queue *q = bdev_get_queue(dev->bdev);
1821
1822         return !blk_queue_nonrot(q);
1823 }
1824
1825 static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
1826                              sector_t start, sector_t len, void *data)
1827 {
1828         struct request_queue *q = bdev_get_queue(dev->bdev);
1829
1830         return !blk_queue_add_random(q);
1831 }
1832
1833 static int device_not_write_same_capable(struct dm_target *ti, struct dm_dev *dev,
1834                                          sector_t start, sector_t len, void *data)
1835 {
1836         struct request_queue *q = bdev_get_queue(dev->bdev);
1837
1838         return !q->limits.max_write_same_sectors;
1839 }
1840
1841 static bool dm_table_supports_write_same(struct dm_table *t)
1842 {
1843         struct dm_target *ti;
1844         unsigned i;
1845
1846         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1847                 ti = dm_table_get_target(t, i);
1848
1849                 if (!ti->num_write_same_bios)
1850                         return false;
1851
1852                 if (!ti->type->iterate_devices ||
1853                     ti->type->iterate_devices(ti, device_not_write_same_capable, NULL))
1854                         return false;
1855         }
1856
1857         return true;
1858 }
1859
1860 static int device_not_write_zeroes_capable(struct dm_target *ti, struct dm_dev *dev,
1861                                            sector_t start, sector_t len, void *data)
1862 {
1863         struct request_queue *q = bdev_get_queue(dev->bdev);
1864
1865         return !q->limits.max_write_zeroes_sectors;
1866 }
1867
1868 static bool dm_table_supports_write_zeroes(struct dm_table *t)
1869 {
1870         struct dm_target *ti;
1871         unsigned i = 0;
1872
1873         while (i < dm_table_get_num_targets(t)) {
1874                 ti = dm_table_get_target(t, i++);
1875
1876                 if (!ti->num_write_zeroes_bios)
1877                         return false;
1878
1879                 if (!ti->type->iterate_devices ||
1880                     ti->type->iterate_devices(ti, device_not_write_zeroes_capable, NULL))
1881                         return false;
1882         }
1883
1884         return true;
1885 }
1886
1887 static int device_not_nowait_capable(struct dm_target *ti, struct dm_dev *dev,
1888                                      sector_t start, sector_t len, void *data)
1889 {
1890         struct request_queue *q = bdev_get_queue(dev->bdev);
1891
1892         return !blk_queue_nowait(q);
1893 }
1894
1895 static bool dm_table_supports_nowait(struct dm_table *t)
1896 {
1897         struct dm_target *ti;
1898         unsigned i = 0;
1899
1900         while (i < dm_table_get_num_targets(t)) {
1901                 ti = dm_table_get_target(t, i++);
1902
1903                 if (!dm_target_supports_nowait(ti->type))
1904                         return false;
1905
1906                 if (!ti->type->iterate_devices ||
1907                     ti->type->iterate_devices(ti, device_not_nowait_capable, NULL))
1908                         return false;
1909         }
1910
1911         return true;
1912 }
1913
1914 static int device_not_discard_capable(struct dm_target *ti, struct dm_dev *dev,
1915                                       sector_t start, sector_t len, void *data)
1916 {
1917         struct request_queue *q = bdev_get_queue(dev->bdev);
1918
1919         return !blk_queue_discard(q);
1920 }
1921
1922 static bool dm_table_supports_discards(struct dm_table *t)
1923 {
1924         struct dm_target *ti;
1925         unsigned i;
1926
1927         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1928                 ti = dm_table_get_target(t, i);
1929
1930                 if (!ti->num_discard_bios)
1931                         return false;
1932
1933                 /*
1934                  * Either the target provides discard support (as implied by setting
1935                  * 'discards_supported') or it relies on _all_ data devices having
1936                  * discard support.
1937                  */
1938                 if (!ti->discards_supported &&
1939                     (!ti->type->iterate_devices ||
1940                      ti->type->iterate_devices(ti, device_not_discard_capable, NULL)))
1941                         return false;
1942         }
1943
1944         return true;
1945 }
1946
1947 static int device_not_secure_erase_capable(struct dm_target *ti,
1948                                            struct dm_dev *dev, sector_t start,
1949                                            sector_t len, void *data)
1950 {
1951         struct request_queue *q = bdev_get_queue(dev->bdev);
1952
1953         return !blk_queue_secure_erase(q);
1954 }
1955
1956 static bool dm_table_supports_secure_erase(struct dm_table *t)
1957 {
1958         struct dm_target *ti;
1959         unsigned int i;
1960
1961         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1962                 ti = dm_table_get_target(t, i);
1963
1964                 if (!ti->num_secure_erase_bios)
1965                         return false;
1966
1967                 if (!ti->type->iterate_devices ||
1968                     ti->type->iterate_devices(ti, device_not_secure_erase_capable, NULL))
1969                         return false;
1970         }
1971
1972         return true;
1973 }
1974
1975 static int device_requires_stable_pages(struct dm_target *ti,
1976                                         struct dm_dev *dev, sector_t start,
1977                                         sector_t len, void *data)
1978 {
1979         struct request_queue *q = bdev_get_queue(dev->bdev);
1980
1981         return blk_queue_stable_writes(q);
1982 }
1983
1984 int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1985                               struct queue_limits *limits)
1986 {
1987         bool wc = false, fua = false;
1988         int page_size = PAGE_SIZE;
1989         int r;
1990
1991         /*
1992          * Copy table's limits to the DM device's request_queue
1993          */
1994         q->limits = *limits;
1995
1996         if (dm_table_supports_nowait(t))
1997                 blk_queue_flag_set(QUEUE_FLAG_NOWAIT, q);
1998         else
1999                 blk_queue_flag_clear(QUEUE_FLAG_NOWAIT, q);
2000
2001         if (!dm_table_supports_discards(t)) {
2002                 blk_queue_flag_clear(QUEUE_FLAG_DISCARD, q);
2003                 /* Must also clear discard limits... */
2004                 q->limits.max_discard_sectors = 0;
2005                 q->limits.max_hw_discard_sectors = 0;
2006                 q->limits.discard_granularity = 0;
2007                 q->limits.discard_alignment = 0;
2008                 q->limits.discard_misaligned = 0;
2009         } else
2010                 blk_queue_flag_set(QUEUE_FLAG_DISCARD, q);
2011
2012         if (dm_table_supports_secure_erase(t))
2013                 blk_queue_flag_set(QUEUE_FLAG_SECERASE, q);
2014
2015         if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_WC))) {
2016                 wc = true;
2017                 if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_FUA)))
2018                         fua = true;
2019         }
2020         blk_queue_write_cache(q, wc, fua);
2021
2022         if (dm_table_supports_dax(t, device_not_dax_capable, &page_size)) {
2023                 blk_queue_flag_set(QUEUE_FLAG_DAX, q);
2024                 if (dm_table_supports_dax(t, device_not_dax_synchronous_capable, NULL))
2025                         set_dax_synchronous(t->md->dax_dev);
2026         }
2027         else
2028                 blk_queue_flag_clear(QUEUE_FLAG_DAX, q);
2029
2030         if (dm_table_any_dev_attr(t, device_dax_write_cache_enabled, NULL))
2031                 dax_write_cache(t->md->dax_dev, true);
2032
2033         /* Ensure that all underlying devices are non-rotational. */
2034         if (dm_table_any_dev_attr(t, device_is_rotational, NULL))
2035                 blk_queue_flag_clear(QUEUE_FLAG_NONROT, q);
2036         else
2037                 blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
2038
2039         if (!dm_table_supports_write_same(t))
2040                 q->limits.max_write_same_sectors = 0;
2041         if (!dm_table_supports_write_zeroes(t))
2042                 q->limits.max_write_zeroes_sectors = 0;
2043
2044         dm_table_verify_integrity(t);
2045
2046         /*
2047          * Some devices don't use blk_integrity but still want stable pages
2048          * because they do their own checksumming.
2049          * If any underlying device requires stable pages, a table must require
2050          * them as well.  Only targets that support iterate_devices are considered:
2051          * don't want error, zero, etc to require stable pages.
2052          */
2053         if (dm_table_any_dev_attr(t, device_requires_stable_pages, NULL))
2054                 blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, q);
2055         else
2056                 blk_queue_flag_clear(QUEUE_FLAG_STABLE_WRITES, q);
2057
2058         /*
2059          * Determine whether or not this queue's I/O timings contribute
2060          * to the entropy pool, Only request-based targets use this.
2061          * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
2062          * have it set.
2063          */
2064         if (blk_queue_add_random(q) &&
2065             dm_table_any_dev_attr(t, device_is_not_random, NULL))
2066                 blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, q);
2067
2068         /*
2069          * For a zoned target, setup the zones related queue attributes
2070          * and resources necessary for zone append emulation if necessary.
2071          */
2072         if (blk_queue_is_zoned(q)) {
2073                 r = dm_set_zones_restrictions(t, q);
2074                 if (r)
2075                         return r;
2076         }
2077
2078         dm_update_keyslot_manager(q, t);
2079         disk_update_readahead(t->md->disk);
2080
2081         return 0;
2082 }
2083
2084 unsigned int dm_table_get_num_targets(struct dm_table *t)
2085 {
2086         return t->num_targets;
2087 }
2088
2089 struct list_head *dm_table_get_devices(struct dm_table *t)
2090 {
2091         return &t->devices;
2092 }
2093
2094 fmode_t dm_table_get_mode(struct dm_table *t)
2095 {
2096         return t->mode;
2097 }
2098 EXPORT_SYMBOL(dm_table_get_mode);
2099
2100 enum suspend_mode {
2101         PRESUSPEND,
2102         PRESUSPEND_UNDO,
2103         POSTSUSPEND,
2104 };
2105
2106 static void suspend_targets(struct dm_table *t, enum suspend_mode mode)
2107 {
2108         int i = t->num_targets;
2109         struct dm_target *ti = t->targets;
2110
2111         lockdep_assert_held(&t->md->suspend_lock);
2112
2113         while (i--) {
2114                 switch (mode) {
2115                 case PRESUSPEND:
2116                         if (ti->type->presuspend)
2117                                 ti->type->presuspend(ti);
2118                         break;
2119                 case PRESUSPEND_UNDO:
2120                         if (ti->type->presuspend_undo)
2121                                 ti->type->presuspend_undo(ti);
2122                         break;
2123                 case POSTSUSPEND:
2124                         if (ti->type->postsuspend)
2125                                 ti->type->postsuspend(ti);
2126                         break;
2127                 }
2128                 ti++;
2129         }
2130 }
2131
2132 void dm_table_presuspend_targets(struct dm_table *t)
2133 {
2134         if (!t)
2135                 return;
2136
2137         suspend_targets(t, PRESUSPEND);
2138 }
2139
2140 void dm_table_presuspend_undo_targets(struct dm_table *t)
2141 {
2142         if (!t)
2143                 return;
2144
2145         suspend_targets(t, PRESUSPEND_UNDO);
2146 }
2147
2148 void dm_table_postsuspend_targets(struct dm_table *t)
2149 {
2150         if (!t)
2151                 return;
2152
2153         suspend_targets(t, POSTSUSPEND);
2154 }
2155
2156 int dm_table_resume_targets(struct dm_table *t)
2157 {
2158         int i, r = 0;
2159
2160         lockdep_assert_held(&t->md->suspend_lock);
2161
2162         for (i = 0; i < t->num_targets; i++) {
2163                 struct dm_target *ti = t->targets + i;
2164
2165                 if (!ti->type->preresume)
2166                         continue;
2167
2168                 r = ti->type->preresume(ti);
2169                 if (r) {
2170                         DMERR("%s: %s: preresume failed, error = %d",
2171                               dm_device_name(t->md), ti->type->name, r);
2172                         return r;
2173                 }
2174         }
2175
2176         for (i = 0; i < t->num_targets; i++) {
2177                 struct dm_target *ti = t->targets + i;
2178
2179                 if (ti->type->resume)
2180                         ti->type->resume(ti);
2181         }
2182
2183         return 0;
2184 }
2185
2186 struct mapped_device *dm_table_get_md(struct dm_table *t)
2187 {
2188         return t->md;
2189 }
2190 EXPORT_SYMBOL(dm_table_get_md);
2191
2192 const char *dm_table_device_name(struct dm_table *t)
2193 {
2194         return dm_device_name(t->md);
2195 }
2196 EXPORT_SYMBOL_GPL(dm_table_device_name);
2197
2198 void dm_table_run_md_queue_async(struct dm_table *t)
2199 {
2200         if (!dm_table_request_based(t))
2201                 return;
2202
2203         if (t->md->queue)
2204                 blk_mq_run_hw_queues(t->md->queue, true);
2205 }
2206 EXPORT_SYMBOL(dm_table_run_md_queue_async);
2207