drivers/md/dm-table.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2001 Sistina Software (UK) Limited.
   4  * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
   5  *
   6  * This file is released under the GPL.
   7  */
   8
   9 #include "dm-core.h"
  10 #include "dm-rq.h"
  11
  12 #include <linux/module.h>
  13 #include <linux/vmalloc.h>
  14 #include <linux/blkdev.h>
  15 #include <linux/blk-integrity.h>
  16 #include <linux/namei.h>
  17 #include <linux/ctype.h>
  18 #include <linux/string.h>
  19 #include <linux/slab.h>
  20 #include <linux/interrupt.h>
  21 #include <linux/mutex.h>
  22 #include <linux/delay.h>
  23 #include <linux/atomic.h>
  24 #include <linux/blk-mq.h>
  25 #include <linux/mount.h>
  26 #include <linux/dax.h>
  27
  28 #define DM_MSG_PREFIX "table"
  29
  30 #define NODE_SIZE L1_CACHE_BYTES
  31 #define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t))
  32 #define CHILDREN_PER_NODE (KEYS_PER_NODE + 1)
  33
  34 /*
  35  * Similar to ceiling(log_size(n))
  36  */
  37 static unsigned int int_log(unsigned int n, unsigned int base)
  38 {
  39         int result = 0;
  40
  41         while (n > 1) {
  42                 n = dm_div_up(n, base);
  43                 result++;
  44         }
  45
  46         return result;
  47 }
  48
  49 /*
  50  * Calculate the index of the child node of the n'th node k'th key.
  51  */
  52 static inline unsigned int get_child(unsigned int n, unsigned int k)
  53 {
  54         return (n * CHILDREN_PER_NODE) + k;
  55 }
  56
  57 /*
  58  * Return the n'th node of level l from table t.
  59  */
  60 static inline sector_t *get_node(struct dm_table *t,
  61                                  unsigned int l, unsigned int n)
  62 {
  63         return t->index[l] + (n * KEYS_PER_NODE);
  64 }
  65
  66 /*
  67  * Return the highest key that you could lookup from the n'th
  68  * node on level l of the btree.
  69  */
  70 static sector_t high(struct dm_table *t, unsigned int l, unsigned int n)
  71 {
  72         for (; l < t->depth - 1; l++)
  73                 n = get_child(n, CHILDREN_PER_NODE - 1);
  74
  75         if (n >= t->counts[l])
  76                 return (sector_t) -1;
  77
  78         return get_node(t, l, n)[KEYS_PER_NODE - 1];
  79 }
  80
  81 /*
  82  * Fills in a level of the btree based on the highs of the level
  83  * below it.
  84  */
  85 static int setup_btree_index(unsigned int l, struct dm_table *t)
  86 {
  87         unsigned int n, k;
  88         sector_t *node;
  89
  90         for (n = 0U; n < t->counts[l]; n++) {
  91                 node = get_node(t, l, n);
  92
  93                 for (k = 0U; k < KEYS_PER_NODE; k++)
  94                         node[k] = high(t, l + 1, get_child(n, k));
  95         }
  96
  97         return 0;
  98 }
  99
 100 /*
 101  * highs, and targets are managed as dynamic arrays during a
 102  * table load.
 103  */
 104 static int alloc_targets(struct dm_table *t, unsigned int num)
 105 {
 106         sector_t *n_highs;
 107         struct dm_target *n_targets;
 108
 109         /*
 110          * Allocate both the target array and offset array at once.
 111          */
 112         n_highs = kvcalloc(num, sizeof(struct dm_target) + sizeof(sector_t),
 113                            GFP_KERNEL);
 114         if (!n_highs)
 115                 return -ENOMEM;
 116
 117         n_targets = (struct dm_target *) (n_highs + num);
 118
 119         memset(n_highs, -1, sizeof(*n_highs) * num);
 120         kvfree(t->highs);
 121
 122         t->num_allocated = num;
 123         t->highs = n_highs;
 124         t->targets = n_targets;
 125
 126         return 0;
 127 }
 128
 129 int dm_table_create(struct dm_table **result, blk_mode_t mode,
 130                     unsigned int num_targets, struct mapped_device *md)
 131 {
 132         struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
 133
 134         if (!t)
 135                 return -ENOMEM;
 136
 137         INIT_LIST_HEAD(&t->devices);
 138         init_rwsem(&t->devices_lock);
 139
 140         if (!num_targets)
 141                 num_targets = KEYS_PER_NODE;
 142
 143         num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
 144
 145         if (!num_targets) {
 146                 kfree(t);
 147                 return -ENOMEM;
 148         }
 149
 150         if (alloc_targets(t, num_targets)) {
 151                 kfree(t);
 152                 return -ENOMEM;
 153         }
 154
 155         t->type = DM_TYPE_NONE;
 156         t->mode = mode;
 157         t->md = md;
 158         *result = t;
 159         return 0;
 160 }
 161
 162 static void free_devices(struct list_head *devices, struct mapped_device *md)
 163 {
 164         struct list_head *tmp, *next;
 165
 166         list_for_each_safe(tmp, next, devices) {
 167                 struct dm_dev_internal *dd =
 168                     list_entry(tmp, struct dm_dev_internal, list);
 169                 DMWARN("%s: dm_table_destroy: dm_put_device call missing for %s",
 170                        dm_device_name(md), dd->dm_dev->name);
 171                 dm_put_table_device(md, dd->dm_dev);
 172                 kfree(dd);
 173         }
 174 }
 175
 176 static void dm_table_destroy_crypto_profile(struct dm_table *t);
 177
 178 void dm_table_destroy(struct dm_table *t)
 179 {
 180         if (!t)
 181                 return;
 182
 183         /* free the indexes */
 184         if (t->depth >= 2)
 185                 kvfree(t->index[t->depth - 2]);
 186
 187         /* free the targets */
 188         for (unsigned int i = 0; i < t->num_targets; i++) {
 189                 struct dm_target *ti = dm_table_get_target(t, i);
 190
 191                 if (ti->type->dtr)
 192                         ti->type->dtr(ti);
 193
 194                 dm_put_target_type(ti->type);
 195         }
 196
 197         kvfree(t->highs);
 198
 199         /* free the device list */
 200         free_devices(&t->devices, t->md);
 201
 202         dm_free_md_mempools(t->mempools);
 203
 204         dm_table_destroy_crypto_profile(t);
 205
 206         kfree(t);
 207 }
 208
 209 /*
 210  * See if we've already got a device in the list.
 211  */
 212 static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
 213 {
 214         struct dm_dev_internal *dd;
 215
 216         list_for_each_entry(dd, l, list)
 217                 if (dd->dm_dev->bdev->bd_dev == dev)
 218                         return dd;
 219
 220         return NULL;
 221 }
 222
 223 /*
 224  * If possible, this checks an area of a destination device is invalid.
 225  */
 226 static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
 227                                   sector_t start, sector_t len, void *data)
 228 {
 229         struct queue_limits *limits = data;
 230         struct block_device *bdev = dev->bdev;
 231         sector_t dev_size = bdev_nr_sectors(bdev);
 232         unsigned short logical_block_size_sectors =
 233                 limits->logical_block_size >> SECTOR_SHIFT;
 234
 235         if (!dev_size)
 236                 return 0;
 237
 238         if ((start >= dev_size) || (start + len > dev_size)) {
 239                 DMERR("%s: %pg too small for target: start=%llu, len=%llu, dev_size=%llu",
 240                       dm_device_name(ti->table->md), bdev,
 241                       (unsigned long long)start,
 242                       (unsigned long long)len,
 243                       (unsigned long long)dev_size);
 244                 return 1;
 245         }
 246
 247         /*
 248          * If the target is mapped to zoned block device(s), check
 249          * that the zones are not partially mapped.
 250          */
 251         if (bdev_is_zoned(bdev)) {
 252                 unsigned int zone_sectors = bdev_zone_sectors(bdev);
 253
 254                 if (start & (zone_sectors - 1)) {
 255                         DMERR("%s: start=%llu not aligned to h/w zone size %u of %pg",
 256                               dm_device_name(ti->table->md),
 257                               (unsigned long long)start,
 258                               zone_sectors, bdev);
 259                         return 1;
 260                 }
 261
 262                 /*
 263                  * Note: The last zone of a zoned block device may be smaller
 264                  * than other zones. So for a target mapping the end of a
 265                  * zoned block device with such a zone, len would not be zone
 266                  * aligned. We do not allow such last smaller zone to be part
 267                  * of the mapping here to ensure that mappings with multiple
 268                  * devices do not end up with a smaller zone in the middle of
 269                  * the sector range.
 270                  */
 271                 if (len & (zone_sectors - 1)) {
 272                         DMERR("%s: len=%llu not aligned to h/w zone size %u of %pg",
 273                               dm_device_name(ti->table->md),
 274                               (unsigned long long)len,
 275                               zone_sectors, bdev);
 276                         return 1;
 277                 }
 278         }
 279
 280         if (logical_block_size_sectors <= 1)
 281                 return 0;
 282
 283         if (start & (logical_block_size_sectors - 1)) {
 284                 DMERR("%s: start=%llu not aligned to h/w logical block size %u of %pg",
 285                       dm_device_name(ti->table->md),
 286                       (unsigned long long)start,
 287                       limits->logical_block_size, bdev);
 288                 return 1;
 289         }
 290
 291         if (len & (logical_block_size_sectors - 1)) {
 292                 DMERR("%s: len=%llu not aligned to h/w logical block size %u of %pg",
 293                       dm_device_name(ti->table->md),
 294                       (unsigned long long)len,
 295                       limits->logical_block_size, bdev);
 296                 return 1;
 297         }
 298
 299         return 0;
 300 }
 301
 302 /*
 303  * This upgrades the mode on an already open dm_dev, being
 304  * careful to leave things as they were if we fail to reopen the
 305  * device and not to touch the existing bdev field in case
 306  * it is accessed concurrently.
 307  */
 308 static int upgrade_mode(struct dm_dev_internal *dd, blk_mode_t new_mode,
 309                         struct mapped_device *md)
 310 {
 311         int r;
 312         struct dm_dev *old_dev, *new_dev;
 313
 314         old_dev = dd->dm_dev;
 315
 316         r = dm_get_table_device(md, dd->dm_dev->bdev->bd_dev,
 317                                 dd->dm_dev->mode | new_mode, &new_dev);
 318         if (r)
 319                 return r;
 320
 321         dd->dm_dev = new_dev;
 322         dm_put_table_device(md, old_dev);
 323
 324         return 0;
 325 }
 326
 327 /*
 328  * Add a device to the list, or just increment the usage count if
 329  * it's already present.
 330  *
 331  * Note: the __ref annotation is because this function can call the __init
 332  * marked early_lookup_bdev when called during early boot code from dm-init.c.
 333  */
 334 int __ref dm_get_device(struct dm_target *ti, const char *path, blk_mode_t mode,
 335                   struct dm_dev **result)
 336 {
 337         int r;
 338         dev_t dev;
 339         unsigned int major, minor;
 340         char dummy;
 341         struct dm_dev_internal *dd;
 342         struct dm_table *t = ti->table;
 343
 344         BUG_ON(!t);
 345
 346         if (sscanf(path, "%u:%u%c", &major, &minor, &dummy) == 2) {
 347                 /* Extract the major/minor numbers */
 348                 dev = MKDEV(major, minor);
 349                 if (MAJOR(dev) != major || MINOR(dev) != minor)
 350                         return -EOVERFLOW;
 351         } else {
 352                 r = lookup_bdev(path, &dev);
 353 #ifndef MODULE
 354                 if (r && system_state < SYSTEM_RUNNING)
 355                         r = early_lookup_bdev(path, &dev);
 356 #endif
 357                 if (r)
 358                         return r;
 359         }
 360         if (dev == disk_devt(t->md->disk))
 361                 return -EINVAL;
 362
 363         down_write(&t->devices_lock);
 364
 365         dd = find_device(&t->devices, dev);
 366         if (!dd) {
 367                 dd = kmalloc(sizeof(*dd), GFP_KERNEL);
 368                 if (!dd) {
 369                         r = -ENOMEM;
 370                         goto unlock_ret_r;
 371                 }
 372
 373                 r = dm_get_table_device(t->md, dev, mode, &dd->dm_dev);
 374                 if (r) {
 375                         kfree(dd);
 376                         goto unlock_ret_r;
 377                 }
 378
 379                 refcount_set(&dd->count, 1);
 380                 list_add(&dd->list, &t->devices);
 381                 goto out;
 382
 383         } else if (dd->dm_dev->mode != (mode | dd->dm_dev->mode)) {
 384                 r = upgrade_mode(dd, mode, t->md);
 385                 if (r)
 386                         goto unlock_ret_r;
 387         }
 388         refcount_inc(&dd->count);
 389 out:
 390         up_write(&t->devices_lock);
 391         *result = dd->dm_dev;
 392         return 0;
 393
 394 unlock_ret_r:
 395         up_write(&t->devices_lock);
 396         return r;
 397 }
 398 EXPORT_SYMBOL(dm_get_device);
 399
 400 static int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
 401                                 sector_t start, sector_t len, void *data)
 402 {
 403         struct queue_limits *limits = data;
 404         struct block_device *bdev = dev->bdev;
 405         struct request_queue *q = bdev_get_queue(bdev);
 406
 407         if (unlikely(!q)) {
 408                 DMWARN("%s: Cannot set limits for nonexistent device %pg",
 409                        dm_device_name(ti->table->md), bdev);
 410                 return 0;
 411         }
 412
 413         if (blk_stack_limits(limits, &q->limits,
 414                         get_start_sect(bdev) + start) < 0)
 415                 DMWARN("%s: adding target device %pg caused an alignment inconsistency: "
 416                        "physical_block_size=%u, logical_block_size=%u, "
 417                        "alignment_offset=%u, start=%llu",
 418                        dm_device_name(ti->table->md), bdev,
 419                        q->limits.physical_block_size,
 420                        q->limits.logical_block_size,
 421                        q->limits.alignment_offset,
 422                        (unsigned long long) start << SECTOR_SHIFT);
 423         return 0;
 424 }
 425
 426 /*
 427  * Decrement a device's use count and remove it if necessary.
 428  */
 429 void dm_put_device(struct dm_target *ti, struct dm_dev *d)
 430 {
 431         int found = 0;
 432         struct dm_table *t = ti->table;
 433         struct list_head *devices = &t->devices;
 434         struct dm_dev_internal *dd;
 435
 436         down_write(&t->devices_lock);
 437
 438         list_for_each_entry(dd, devices, list) {
 439                 if (dd->dm_dev == d) {
 440                         found = 1;
 441                         break;
 442                 }
 443         }
 444         if (!found) {
 445                 DMERR("%s: device %s not in table devices list",
 446                       dm_device_name(t->md), d->name);
 447                 goto unlock_ret;
 448         }
 449         if (refcount_dec_and_test(&dd->count)) {
 450                 dm_put_table_device(t->md, d);
 451                 list_del(&dd->list);
 452                 kfree(dd);
 453         }
 454
 455 unlock_ret:
 456         up_write(&t->devices_lock);
 457 }
 458 EXPORT_SYMBOL(dm_put_device);
 459
 460 /*
 461  * Checks to see if the target joins onto the end of the table.
 462  */
 463 static int adjoin(struct dm_table *t, struct dm_target *ti)
 464 {
 465         struct dm_target *prev;
 466
 467         if (!t->num_targets)
 468                 return !ti->begin;
 469
 470         prev = &t->targets[t->num_targets - 1];
 471         return (ti->begin == (prev->begin + prev->len));
 472 }
 473
 474 /*
 475  * Used to dynamically allocate the arg array.
 476  *
 477  * We do first allocation with GFP_NOIO because dm-mpath and dm-thin must
 478  * process messages even if some device is suspended. These messages have a
 479  * small fixed number of arguments.
 480  *
 481  * On the other hand, dm-switch needs to process bulk data using messages and
 482  * excessive use of GFP_NOIO could cause trouble.
 483  */
 484 static char **realloc_argv(unsigned int *size, char **old_argv)
 485 {
 486         char **argv;
 487         unsigned int new_size;
 488         gfp_t gfp;
 489
 490         if (*size) {
 491                 new_size = *size * 2;
 492                 gfp = GFP_KERNEL;
 493         } else {
 494                 new_size = 8;
 495                 gfp = GFP_NOIO;
 496         }
 497         argv = kmalloc_array(new_size, sizeof(*argv), gfp);
 498         if (argv && old_argv) {
 499                 memcpy(argv, old_argv, *size * sizeof(*argv));
 500                 *size = new_size;
 501         }
 502
 503         kfree(old_argv);
 504         return argv;
 505 }
 506
 507 /*
 508  * Destructively splits up the argument list to pass to ctr.
 509  */
 510 int dm_split_args(int *argc, char ***argvp, char *input)
 511 {
 512         char *start, *end = input, *out, **argv = NULL;
 513         unsigned int array_size = 0;
 514
 515         *argc = 0;
 516
 517         if (!input) {
 518                 *argvp = NULL;
 519                 return 0;
 520         }
 521
 522         argv = realloc_argv(&array_size, argv);
 523         if (!argv)
 524                 return -ENOMEM;
 525
 526         while (1) {
 527                 /* Skip whitespace */
 528                 start = skip_spaces(end);
 529
 530                 if (!*start)
 531                         break;  /* success, we hit the end */
 532
 533                 /* 'out' is used to remove any back-quotes */
 534                 end = out = start;
 535                 while (*end) {
 536                         /* Everything apart from '\0' can be quoted */
 537                         if (*end == '\\' && *(end + 1)) {
 538                                 *out++ = *(end + 1);
 539                                 end += 2;
 540                                 continue;
 541                         }
 542
 543                         if (isspace(*end))
 544                                 break;  /* end of token */
 545
 546                         *out++ = *end++;
 547                 }
 548
 549                 /* have we already filled the array ? */
 550                 if ((*argc + 1) > array_size) {
 551                         argv = realloc_argv(&array_size, argv);
 552                         if (!argv)
 553                                 return -ENOMEM;
 554                 }
 555
 556                 /* we know this is whitespace */
 557                 if (*end)
 558                         end++;
 559
 560                 /* terminate the string and put it in the array */
 561                 *out = '\0';
 562                 argv[*argc] = start;
 563                 (*argc)++;
 564         }
 565
 566         *argvp = argv;
 567         return 0;
 568 }
 569
 570 /*
 571  * Impose necessary and sufficient conditions on a devices's table such
 572  * that any incoming bio which respects its logical_block_size can be
 573  * processed successfully.  If it falls across the boundary between
 574  * two or more targets, the size of each piece it gets split into must
 575  * be compatible with the logical_block_size of the target processing it.
 576  */
 577 static int validate_hardware_logical_block_alignment(struct dm_table *t,
 578                                                      struct queue_limits *limits)
 579 {
 580         /*
 581          * This function uses arithmetic modulo the logical_block_size
 582          * (in units of 512-byte sectors).
 583          */
 584         unsigned short device_logical_block_size_sects =
 585                 limits->logical_block_size >> SECTOR_SHIFT;
 586
 587         /*
 588          * Offset of the start of the next table entry, mod logical_block_size.
 589          */
 590         unsigned short next_target_start = 0;
 591
 592         /*
 593          * Given an aligned bio that extends beyond the end of a
 594          * target, how many sectors must the next target handle?
 595          */
 596         unsigned short remaining = 0;
 597
 598         struct dm_target *ti;
 599         struct queue_limits ti_limits;
 600         unsigned int i;
 601
 602         /*
 603          * Check each entry in the table in turn.
 604          */
 605         for (i = 0; i < t->num_targets; i++) {
 606                 ti = dm_table_get_target(t, i);
 607
 608                 blk_set_stacking_limits(&ti_limits);
 609
 610                 /* combine all target devices' limits */
 611                 if (ti->type->iterate_devices)
 612                         ti->type->iterate_devices(ti, dm_set_device_limits,
 613                                                   &ti_limits);
 614
 615                 /*
 616                  * If the remaining sectors fall entirely within this
 617                  * table entry are they compatible with its logical_block_size?
 618                  */
 619                 if (remaining < ti->len &&
 620                     remaining & ((ti_limits.logical_block_size >>
 621                                   SECTOR_SHIFT) - 1))
 622                         break;  /* Error */
 623
 624                 next_target_start =
 625                     (unsigned short) ((next_target_start + ti->len) &
 626                                       (device_logical_block_size_sects - 1));
 627                 remaining = next_target_start ?
 628                     device_logical_block_size_sects - next_target_start : 0;
 629         }
 630
 631         if (remaining) {
 632                 DMERR("%s: table line %u (start sect %llu len %llu) "
 633                       "not aligned to h/w logical block size %u",
 634                       dm_device_name(t->md), i,
 635                       (unsigned long long) ti->begin,
 636                       (unsigned long long) ti->len,
 637                       limits->logical_block_size);
 638                 return -EINVAL;
 639         }
 640
 641         return 0;
 642 }
 643
 644 int dm_table_add_target(struct dm_table *t, const char *type,
 645                         sector_t start, sector_t len, char *params)
 646 {
 647         int r = -EINVAL, argc;
 648         char **argv;
 649         struct dm_target *ti;
 650
 651         if (t->singleton) {
 652                 DMERR("%s: target type %s must appear alone in table",
 653                       dm_device_name(t->md), t->targets->type->name);
 654                 return -EINVAL;
 655         }
 656
 657         BUG_ON(t->num_targets >= t->num_allocated);
 658
 659         ti = t->targets + t->num_targets;
 660         memset(ti, 0, sizeof(*ti));
 661
 662         if (!len) {
 663                 DMERR("%s: zero-length target", dm_device_name(t->md));
 664                 return -EINVAL;
 665         }
 666
 667         ti->type = dm_get_target_type(type);
 668         if (!ti->type) {
 669                 DMERR("%s: %s: unknown target type", dm_device_name(t->md), type);
 670                 return -EINVAL;
 671         }
 672
 673         if (dm_target_needs_singleton(ti->type)) {
 674                 if (t->num_targets) {
 675                         ti->error = "singleton target type must appear alone in table";
 676                         goto bad;
 677                 }
 678                 t->singleton = true;
 679         }
 680
 681         if (dm_target_always_writeable(ti->type) &&
 682             !(t->mode & BLK_OPEN_WRITE)) {
 683                 ti->error = "target type may not be included in a read-only table";
 684                 goto bad;
 685         }
 686
 687         if (t->immutable_target_type) {
 688                 if (t->immutable_target_type != ti->type) {
 689                         ti->error = "immutable target type cannot be mixed with other target types";
 690                         goto bad;
 691                 }
 692         } else if (dm_target_is_immutable(ti->type)) {
 693                 if (t->num_targets) {
 694                         ti->error = "immutable target type cannot be mixed with other target types";
 695                         goto bad;
 696                 }
 697                 t->immutable_target_type = ti->type;
 698         }
 699
 700         if (dm_target_has_integrity(ti->type))
 701                 t->integrity_added = 1;
 702
 703         ti->table = t;
 704         ti->begin = start;
 705         ti->len = len;
 706         ti->error = "Unknown error";
 707
 708         /*
 709          * Does this target adjoin the previous one ?
 710          */
 711         if (!adjoin(t, ti)) {
 712                 ti->error = "Gap in table";
 713                 goto bad;
 714         }
 715
 716         r = dm_split_args(&argc, &argv, params);
 717         if (r) {
 718                 ti->error = "couldn't split parameters";
 719                 goto bad;
 720         }
 721
 722         r = ti->type->ctr(ti, argc, argv);
 723         kfree(argv);
 724         if (r)
 725                 goto bad;
 726
 727         t->highs[t->num_targets++] = ti->begin + ti->len - 1;
 728
 729         if (!ti->num_discard_bios && ti->discards_supported)
 730                 DMWARN("%s: %s: ignoring discards_supported because num_discard_bios is zero.",
 731                        dm_device_name(t->md), type);
 732
 733         if (ti->limit_swap_bios && !static_key_enabled(&swap_bios_enabled.key))
 734                 static_branch_enable(&swap_bios_enabled);
 735
 736         return 0;
 737
 738  bad:
 739         DMERR("%s: %s: %s (%pe)", dm_device_name(t->md), type, ti->error, ERR_PTR(r));
 740         dm_put_target_type(ti->type);
 741         return r;
 742 }
 743
 744 /*
 745  * Target argument parsing helpers.
 746  */
 747 static int validate_next_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
 748                              unsigned int *value, char **error, unsigned int grouped)
 749 {
 750         const char *arg_str = dm_shift_arg(arg_set);
 751         char dummy;
 752
 753         if (!arg_str ||
 754             (sscanf(arg_str, "%u%c", value, &dummy) != 1) ||
 755             (*value < arg->min) ||
 756             (*value > arg->max) ||
 757             (grouped && arg_set->argc < *value)) {
 758                 *error = arg->error;
 759                 return -EINVAL;
 760         }
 761
 762         return 0;
 763 }
 764
 765 int dm_read_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
 766                 unsigned int *value, char **error)
 767 {
 768         return validate_next_arg(arg, arg_set, value, error, 0);
 769 }
 770 EXPORT_SYMBOL(dm_read_arg);
 771
 772 int dm_read_arg_group(const struct dm_arg *arg, struct dm_arg_set *arg_set,
 773                       unsigned int *value, char **error)
 774 {
 775         return validate_next_arg(arg, arg_set, value, error, 1);
 776 }
 777 EXPORT_SYMBOL(dm_read_arg_group);
 778
 779 const char *dm_shift_arg(struct dm_arg_set *as)
 780 {
 781         char *r;
 782
 783         if (as->argc) {
 784                 as->argc--;
 785                 r = *as->argv;
 786                 as->argv++;
 787                 return r;
 788         }
 789
 790         return NULL;
 791 }
 792 EXPORT_SYMBOL(dm_shift_arg);
 793
 794 void dm_consume_args(struct dm_arg_set *as, unsigned int num_args)
 795 {
 796         BUG_ON(as->argc < num_args);
 797         as->argc -= num_args;
 798         as->argv += num_args;
 799 }
 800 EXPORT_SYMBOL(dm_consume_args);
 801
 802 static bool __table_type_bio_based(enum dm_queue_mode table_type)
 803 {
 804         return (table_type == DM_TYPE_BIO_BASED ||
 805                 table_type == DM_TYPE_DAX_BIO_BASED);
 806 }
 807
 808 static bool __table_type_request_based(enum dm_queue_mode table_type)
 809 {
 810         return table_type == DM_TYPE_REQUEST_BASED;
 811 }
 812
 813 void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type)
 814 {
 815         t->type = type;
 816 }
 817 EXPORT_SYMBOL_GPL(dm_table_set_type);
 818
 819 /* validate the dax capability of the target device span */
 820 static int device_not_dax_capable(struct dm_target *ti, struct dm_dev *dev,
 821                         sector_t start, sector_t len, void *data)
 822 {
 823         if (dev->dax_dev)
 824                 return false;
 825
 826         DMDEBUG("%pg: error: dax unsupported by block device", dev->bdev);
 827         return true;
 828 }
 829
 830 /* Check devices support synchronous DAX */
 831 static int device_not_dax_synchronous_capable(struct dm_target *ti, struct dm_dev *dev,
 832                                               sector_t start, sector_t len, void *data)
 833 {
 834         return !dev->dax_dev || !dax_synchronous(dev->dax_dev);
 835 }
 836
 837 static bool dm_table_supports_dax(struct dm_table *t,
 838                                   iterate_devices_callout_fn iterate_fn)
 839 {
 840         /* Ensure that all targets support DAX. */
 841         for (unsigned int i = 0; i < t->num_targets; i++) {
 842                 struct dm_target *ti = dm_table_get_target(t, i);
 843
 844                 if (!ti->type->direct_access)
 845                         return false;
 846
 847                 if (dm_target_is_wildcard(ti->type) ||
 848                     !ti->type->iterate_devices ||
 849                     ti->type->iterate_devices(ti, iterate_fn, NULL))
 850                         return false;
 851         }
 852
 853         return true;
 854 }
 855
 856 static int device_is_rq_stackable(struct dm_target *ti, struct dm_dev *dev,
 857                                   sector_t start, sector_t len, void *data)
 858 {
 859         struct block_device *bdev = dev->bdev;
 860         struct request_queue *q = bdev_get_queue(bdev);
 861
 862         /* request-based cannot stack on partitions! */
 863         if (bdev_is_partition(bdev))
 864                 return false;
 865
 866         return queue_is_mq(q);
 867 }
 868
 869 static int dm_table_determine_type(struct dm_table *t)
 870 {
 871         unsigned int bio_based = 0, request_based = 0, hybrid = 0;
 872         struct dm_target *ti;
 873         struct list_head *devices = dm_table_get_devices(t);
 874         enum dm_queue_mode live_md_type = dm_get_md_type(t->md);
 875
 876         if (t->type != DM_TYPE_NONE) {
 877                 /* target already set the table's type */
 878                 if (t->type == DM_TYPE_BIO_BASED) {
 879                         /* possibly upgrade to a variant of bio-based */
 880                         goto verify_bio_based;
 881                 }
 882                 BUG_ON(t->type == DM_TYPE_DAX_BIO_BASED);
 883                 goto verify_rq_based;
 884         }
 885
 886         for (unsigned int i = 0; i < t->num_targets; i++) {
 887                 ti = dm_table_get_target(t, i);
 888                 if (dm_target_hybrid(ti))
 889                         hybrid = 1;
 890                 else if (dm_target_request_based(ti))
 891                         request_based = 1;
 892                 else
 893                         bio_based = 1;
 894
 895                 if (bio_based && request_based) {
 896                         DMERR("Inconsistent table: different target types can't be mixed up");
 897                         return -EINVAL;
 898                 }
 899         }
 900
 901         if (hybrid && !bio_based && !request_based) {
 902                 /*
 903                  * The targets can work either way.
 904                  * Determine the type from the live device.
 905                  * Default to bio-based if device is new.
 906                  */
 907                 if (__table_type_request_based(live_md_type))
 908                         request_based = 1;
 909                 else
 910                         bio_based = 1;
 911         }
 912
 913         if (bio_based) {
 914 verify_bio_based:
 915                 /* We must use this table as bio-based */
 916                 t->type = DM_TYPE_BIO_BASED;
 917                 if (dm_table_supports_dax(t, device_not_dax_capable) ||
 918                     (list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED)) {
 919                         t->type = DM_TYPE_DAX_BIO_BASED;
 920                 }
 921                 return 0;
 922         }
 923
 924         BUG_ON(!request_based); /* No targets in this table */
 925
 926         t->type = DM_TYPE_REQUEST_BASED;
 927
 928 verify_rq_based:
 929         /*
 930          * Request-based dm supports only tables that have a single target now.
 931          * To support multiple targets, request splitting support is needed,
 932          * and that needs lots of changes in the block-layer.
 933          * (e.g. request completion process for partial completion.)
 934          */
 935         if (t->num_targets > 1) {
 936                 DMERR("request-based DM doesn't support multiple targets");
 937                 return -EINVAL;
 938         }
 939
 940         if (list_empty(devices)) {
 941                 int srcu_idx;
 942                 struct dm_table *live_table = dm_get_live_table(t->md, &srcu_idx);
 943
 944                 /* inherit live table's type */
 945                 if (live_table)
 946                         t->type = live_table->type;
 947                 dm_put_live_table(t->md, srcu_idx);
 948                 return 0;
 949         }
 950
 951         ti = dm_table_get_immutable_target(t);
 952         if (!ti) {
 953                 DMERR("table load rejected: immutable target is required");
 954                 return -EINVAL;
 955         } else if (ti->max_io_len) {
 956                 DMERR("table load rejected: immutable target that splits IO is not supported");
 957                 return -EINVAL;
 958         }
 959
 960         /* Non-request-stackable devices can't be used for request-based dm */
 961         if (!ti->type->iterate_devices ||
 962             !ti->type->iterate_devices(ti, device_is_rq_stackable, NULL)) {
 963                 DMERR("table load rejected: including non-request-stackable devices");
 964                 return -EINVAL;
 965         }
 966
 967         return 0;
 968 }
 969
 970 enum dm_queue_mode dm_table_get_type(struct dm_table *t)
 971 {
 972         return t->type;
 973 }
 974
 975 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
 976 {
 977         return t->immutable_target_type;
 978 }
 979
 980 struct dm_target *dm_table_get_immutable_target(struct dm_table *t)
 981 {
 982         /* Immutable target is implicitly a singleton */
 983         if (t->num_targets > 1 ||
 984             !dm_target_is_immutable(t->targets[0].type))
 985                 return NULL;
 986
 987         return t->targets;
 988 }
 989
 990 struct dm_target *dm_table_get_wildcard_target(struct dm_table *t)
 991 {
 992         for (unsigned int i = 0; i < t->num_targets; i++) {
 993                 struct dm_target *ti = dm_table_get_target(t, i);
 994
 995                 if (dm_target_is_wildcard(ti->type))
 996                         return ti;
 997         }
 998
 999         return NULL;
1000 }
1001
1002 bool dm_table_bio_based(struct dm_table *t)
1003 {
1004         return __table_type_bio_based(dm_table_get_type(t));
1005 }
1006
1007 bool dm_table_request_based(struct dm_table *t)
1008 {
1009         return __table_type_request_based(dm_table_get_type(t));
1010 }
1011
1012 static bool dm_table_supports_poll(struct dm_table *t);
1013
1014 static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device *md)
1015 {
1016         enum dm_queue_mode type = dm_table_get_type(t);
1017         unsigned int per_io_data_size = 0, front_pad, io_front_pad;
1018         unsigned int min_pool_size = 0, pool_size;
1019         struct dm_md_mempools *pools;
1020
1021         if (unlikely(type == DM_TYPE_NONE)) {
1022                 DMERR("no table type is set, can't allocate mempools");
1023                 return -EINVAL;
1024         }
1025
1026         pools = kzalloc_node(sizeof(*pools), GFP_KERNEL, md->numa_node_id);
1027         if (!pools)
1028                 return -ENOMEM;
1029
1030         if (type == DM_TYPE_REQUEST_BASED) {
1031                 pool_size = dm_get_reserved_rq_based_ios();
1032                 front_pad = offsetof(struct dm_rq_clone_bio_info, clone);
1033                 goto init_bs;
1034         }
1035
1036         for (unsigned int i = 0; i < t->num_targets; i++) {
1037                 struct dm_target *ti = dm_table_get_target(t, i);
1038
1039                 per_io_data_size = max(per_io_data_size, ti->per_io_data_size);
1040                 min_pool_size = max(min_pool_size, ti->num_flush_bios);
1041         }
1042         pool_size = max(dm_get_reserved_bio_based_ios(), min_pool_size);
1043         front_pad = roundup(per_io_data_size,
1044                 __alignof__(struct dm_target_io)) + DM_TARGET_IO_BIO_OFFSET;
1045
1046         io_front_pad = roundup(per_io_data_size,
1047                 __alignof__(struct dm_io)) + DM_IO_BIO_OFFSET;
1048         if (bioset_init(&pools->io_bs, pool_size, io_front_pad,
1049                         dm_table_supports_poll(t) ? BIOSET_PERCPU_CACHE : 0))
1050                 goto out_free_pools;
1051         if (t->integrity_supported &&
1052             bioset_integrity_create(&pools->io_bs, pool_size))
1053                 goto out_free_pools;
1054 init_bs:
1055         if (bioset_init(&pools->bs, pool_size, front_pad, 0))
1056                 goto out_free_pools;
1057         if (t->integrity_supported &&
1058             bioset_integrity_create(&pools->bs, pool_size))
1059                 goto out_free_pools;
1060
1061         t->mempools = pools;
1062         return 0;
1063
1064 out_free_pools:
1065         dm_free_md_mempools(pools);
1066         return -ENOMEM;
1067 }
1068
1069 static int setup_indexes(struct dm_table *t)
1070 {
1071         int i;
1072         unsigned int total = 0;
1073         sector_t *indexes;
1074
1075         /* allocate the space for *all* the indexes */
1076         for (i = t->depth - 2; i >= 0; i--) {
1077                 t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
1078                 total += t->counts[i];
1079         }
1080
1081         indexes = kvcalloc(total, NODE_SIZE, GFP_KERNEL);
1082         if (!indexes)
1083                 return -ENOMEM;
1084
1085         /* set up internal nodes, bottom-up */
1086         for (i = t->depth - 2; i >= 0; i--) {
1087                 t->index[i] = indexes;
1088                 indexes += (KEYS_PER_NODE * t->counts[i]);
1089                 setup_btree_index(i, t);
1090         }
1091
1092         return 0;
1093 }
1094
1095 /*
1096  * Builds the btree to index the map.
1097  */
1098 static int dm_table_build_index(struct dm_table *t)
1099 {
1100         int r = 0;
1101         unsigned int leaf_nodes;
1102
1103         /* how many indexes will the btree have ? */
1104         leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
1105         t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
1106
1107         /* leaf layer has already been set up */
1108         t->counts[t->depth - 1] = leaf_nodes;
1109         t->index[t->depth - 1] = t->highs;
1110
1111         if (t->depth >= 2)
1112                 r = setup_indexes(t);
1113
1114         return r;
1115 }
1116
1117 static bool integrity_profile_exists(struct gendisk *disk)
1118 {
1119         return !!blk_get_integrity(disk);
1120 }
1121
1122 /*
1123  * Get a disk whose integrity profile reflects the table's profile.
1124  * Returns NULL if integrity support was inconsistent or unavailable.
1125  */
1126 static struct gendisk *dm_table_get_integrity_disk(struct dm_table *t)
1127 {
1128         struct list_head *devices = dm_table_get_devices(t);
1129         struct dm_dev_internal *dd = NULL;
1130         struct gendisk *prev_disk = NULL, *template_disk = NULL;
1131
1132         for (unsigned int i = 0; i < t->num_targets; i++) {
1133                 struct dm_target *ti = dm_table_get_target(t, i);
1134
1135                 if (!dm_target_passes_integrity(ti->type))
1136                         goto no_integrity;
1137         }
1138
1139         list_for_each_entry(dd, devices, list) {
1140                 template_disk = dd->dm_dev->bdev->bd_disk;
1141                 if (!integrity_profile_exists(template_disk))
1142                         goto no_integrity;
1143                 else if (prev_disk &&
1144                          blk_integrity_compare(prev_disk, template_disk) < 0)
1145                         goto no_integrity;
1146                 prev_disk = template_disk;
1147         }
1148
1149         return template_disk;
1150
1151 no_integrity:
1152         if (prev_disk)
1153                 DMWARN("%s: integrity not set: %s and %s profile mismatch",
1154                        dm_device_name(t->md),
1155                        prev_disk->disk_name,
1156                        template_disk->disk_name);
1157         return NULL;
1158 }
1159
1160 /*
1161  * Register the mapped device for blk_integrity support if the
1162  * underlying devices have an integrity profile.  But all devices may
1163  * not have matching profiles (checking all devices isn't reliable
1164  * during table load because this table may use other DM device(s) which
1165  * must be resumed before they will have an initialized integity
1166  * profile).  Consequently, stacked DM devices force a 2 stage integrity
1167  * profile validation: First pass during table load, final pass during
1168  * resume.
1169  */
1170 static int dm_table_register_integrity(struct dm_table *t)
1171 {
1172         struct mapped_device *md = t->md;
1173         struct gendisk *template_disk = NULL;
1174
1175         /* If target handles integrity itself do not register it here. */
1176         if (t->integrity_added)
1177                 return 0;
1178
1179         template_disk = dm_table_get_integrity_disk(t);
1180         if (!template_disk)
1181                 return 0;
1182
1183         if (!integrity_profile_exists(dm_disk(md))) {
1184                 t->integrity_supported = true;
1185                 /*
1186                  * Register integrity profile during table load; we can do
1187                  * this because the final profile must match during resume.
1188                  */
1189                 blk_integrity_register(dm_disk(md),
1190                                        blk_get_integrity(template_disk));
1191                 return 0;
1192         }
1193
1194         /*
1195          * If DM device already has an initialized integrity
1196          * profile the new profile should not conflict.
1197          */
1198         if (blk_integrity_compare(dm_disk(md), template_disk) < 0) {
1199                 DMERR("%s: conflict with existing integrity profile: %s profile mismatch",
1200                       dm_device_name(t->md),
1201                       template_disk->disk_name);
1202                 return 1;
1203         }
1204
1205         /* Preserve existing integrity profile */
1206         t->integrity_supported = true;
1207         return 0;
1208 }
1209
1210 #ifdef CONFIG_BLK_INLINE_ENCRYPTION
1211
1212 struct dm_crypto_profile {
1213         struct blk_crypto_profile profile;
1214         struct mapped_device *md;
1215 };
1216
1217 static int dm_keyslot_evict_callback(struct dm_target *ti, struct dm_dev *dev,
1218                                      sector_t start, sector_t len, void *data)
1219 {
1220         const struct blk_crypto_key *key = data;
1221
1222         blk_crypto_evict_key(dev->bdev, key);
1223         return 0;
1224 }
1225
1226 /*
1227  * When an inline encryption key is evicted from a device-mapper device, evict
1228  * it from all the underlying devices.
1229  */
1230 static int dm_keyslot_evict(struct blk_crypto_profile *profile,
1231                             const struct blk_crypto_key *key, unsigned int slot)
1232 {
1233         struct mapped_device *md =
1234                 container_of(profile, struct dm_crypto_profile, profile)->md;
1235         struct dm_table *t;
1236         int srcu_idx;
1237
1238         t = dm_get_live_table(md, &srcu_idx);
1239         if (!t)
1240                 return 0;
1241
1242         for (unsigned int i = 0; i < t->num_targets; i++) {
1243                 struct dm_target *ti = dm_table_get_target(t, i);
1244
1245                 if (!ti->type->iterate_devices)
1246                         continue;
1247                 ti->type->iterate_devices(ti, dm_keyslot_evict_callback,
1248                                           (void *)key);
1249         }
1250
1251         dm_put_live_table(md, srcu_idx);
1252         return 0;
1253 }
1254
1255 static int
1256 device_intersect_crypto_capabilities(struct dm_target *ti, struct dm_dev *dev,
1257                                      sector_t start, sector_t len, void *data)
1258 {
1259         struct blk_crypto_profile *parent = data;
1260         struct blk_crypto_profile *child =
1261                 bdev_get_queue(dev->bdev)->crypto_profile;
1262
1263         blk_crypto_intersect_capabilities(parent, child);
1264         return 0;
1265 }
1266
1267 void dm_destroy_crypto_profile(struct blk_crypto_profile *profile)
1268 {
1269         struct dm_crypto_profile *dmcp = container_of(profile,
1270                                                       struct dm_crypto_profile,
1271                                                       profile);
1272
1273         if (!profile)
1274                 return;
1275
1276         blk_crypto_profile_destroy(profile);
1277         kfree(dmcp);
1278 }
1279
1280 static void dm_table_destroy_crypto_profile(struct dm_table *t)
1281 {
1282         dm_destroy_crypto_profile(t->crypto_profile);
1283         t->crypto_profile = NULL;
1284 }
1285
1286 /*
1287  * Constructs and initializes t->crypto_profile with a crypto profile that
1288  * represents the common set of crypto capabilities of the devices described by
1289  * the dm_table.  However, if the constructed crypto profile doesn't support all
1290  * crypto capabilities that are supported by the current mapped_device, it
1291  * returns an error instead, since we don't support removing crypto capabilities
1292  * on table changes.  Finally, if the constructed crypto profile is "empty" (has
1293  * no crypto capabilities at all), it just sets t->crypto_profile to NULL.
1294  */
1295 static int dm_table_construct_crypto_profile(struct dm_table *t)
1296 {
1297         struct dm_crypto_profile *dmcp;
1298         struct blk_crypto_profile *profile;
1299         unsigned int i;
1300         bool empty_profile = true;
1301
1302         dmcp = kmalloc(sizeof(*dmcp), GFP_KERNEL);
1303         if (!dmcp)
1304                 return -ENOMEM;
1305         dmcp->md = t->md;
1306
1307         profile = &dmcp->profile;
1308         blk_crypto_profile_init(profile, 0);
1309         profile->ll_ops.keyslot_evict = dm_keyslot_evict;
1310         profile->max_dun_bytes_supported = UINT_MAX;
1311         memset(profile->modes_supported, 0xFF,
1312                sizeof(profile->modes_supported));
1313
1314         for (i = 0; i < t->num_targets; i++) {
1315                 struct dm_target *ti = dm_table_get_target(t, i);
1316
1317                 if (!dm_target_passes_crypto(ti->type)) {
1318                         blk_crypto_intersect_capabilities(profile, NULL);
1319                         break;
1320                 }
1321                 if (!ti->type->iterate_devices)
1322                         continue;
1323                 ti->type->iterate_devices(ti,
1324                                           device_intersect_crypto_capabilities,
1325                                           profile);
1326         }
1327
1328         if (t->md->queue &&
1329             !blk_crypto_has_capabilities(profile,
1330                                          t->md->queue->crypto_profile)) {
1331                 DMERR("Inline encryption capabilities of new DM table were more restrictive than the old table's. This is not supported!");
1332                 dm_destroy_crypto_profile(profile);
1333                 return -EINVAL;
1334         }
1335
1336         /*
1337          * If the new profile doesn't actually support any crypto capabilities,
1338          * we may as well represent it with a NULL profile.
1339          */
1340         for (i = 0; i < ARRAY_SIZE(profile->modes_supported); i++) {
1341                 if (profile->modes_supported[i]) {
1342                         empty_profile = false;
1343                         break;
1344                 }
1345         }
1346
1347         if (empty_profile) {
1348                 dm_destroy_crypto_profile(profile);
1349                 profile = NULL;
1350         }
1351
1352         /*
1353          * t->crypto_profile is only set temporarily while the table is being
1354          * set up, and it gets set to NULL after the profile has been
1355          * transferred to the request_queue.
1356          */
1357         t->crypto_profile = profile;
1358
1359         return 0;
1360 }
1361
1362 static void dm_update_crypto_profile(struct request_queue *q,
1363                                      struct dm_table *t)
1364 {
1365         if (!t->crypto_profile)
1366                 return;
1367
1368         /* Make the crypto profile less restrictive. */
1369         if (!q->crypto_profile) {
1370                 blk_crypto_register(t->crypto_profile, q);
1371         } else {
1372                 blk_crypto_update_capabilities(q->crypto_profile,
1373                                                t->crypto_profile);
1374                 dm_destroy_crypto_profile(t->crypto_profile);
1375         }
1376         t->crypto_profile = NULL;
1377 }
1378
1379 #else /* CONFIG_BLK_INLINE_ENCRYPTION */
1380
1381 static int dm_table_construct_crypto_profile(struct dm_table *t)
1382 {
1383         return 0;
1384 }
1385
1386 void dm_destroy_crypto_profile(struct blk_crypto_profile *profile)
1387 {
1388 }
1389
1390 static void dm_table_destroy_crypto_profile(struct dm_table *t)
1391 {
1392 }
1393
1394 static void dm_update_crypto_profile(struct request_queue *q,
1395                                      struct dm_table *t)
1396 {
1397 }
1398
1399 #endif /* !CONFIG_BLK_INLINE_ENCRYPTION */
1400
1401 /*
1402  * Prepares the table for use by building the indices,
1403  * setting the type, and allocating mempools.
1404  */
1405 int dm_table_complete(struct dm_table *t)
1406 {
1407         int r;
1408
1409         r = dm_table_determine_type(t);
1410         if (r) {
1411                 DMERR("unable to determine table type");
1412                 return r;
1413         }
1414
1415         r = dm_table_build_index(t);
1416         if (r) {
1417                 DMERR("unable to build btrees");
1418                 return r;
1419         }
1420
1421         r = dm_table_register_integrity(t);
1422         if (r) {
1423                 DMERR("could not register integrity profile.");
1424                 return r;
1425         }
1426
1427         r = dm_table_construct_crypto_profile(t);
1428         if (r) {
1429                 DMERR("could not construct crypto profile.");
1430                 return r;
1431         }
1432
1433         r = dm_table_alloc_md_mempools(t, t->md);
1434         if (r)
1435                 DMERR("unable to allocate mempools");
1436
1437         return r;
1438 }
1439
1440 static DEFINE_MUTEX(_event_lock);
1441 void dm_table_event_callback(struct dm_table *t,
1442                              void (*fn)(void *), void *context)
1443 {
1444         mutex_lock(&_event_lock);
1445         t->event_fn = fn;
1446         t->event_context = context;
1447         mutex_unlock(&_event_lock);
1448 }
1449
1450 void dm_table_event(struct dm_table *t)
1451 {
1452         mutex_lock(&_event_lock);
1453         if (t->event_fn)
1454                 t->event_fn(t->event_context);
1455         mutex_unlock(&_event_lock);
1456 }
1457 EXPORT_SYMBOL(dm_table_event);
1458
1459 inline sector_t dm_table_get_size(struct dm_table *t)
1460 {
1461         return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1462 }
1463 EXPORT_SYMBOL(dm_table_get_size);
1464
1465 /*
1466  * Search the btree for the correct target.
1467  *
1468  * Caller should check returned pointer for NULL
1469  * to trap I/O beyond end of device.
1470  */
1471 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1472 {
1473         unsigned int l, n = 0, k = 0;
1474         sector_t *node;
1475
1476         if (unlikely(sector >= dm_table_get_size(t)))
1477                 return NULL;
1478
1479         for (l = 0; l < t->depth; l++) {
1480                 n = get_child(n, k);
1481                 node = get_node(t, l, n);
1482
1483                 for (k = 0; k < KEYS_PER_NODE; k++)
1484                         if (node[k] >= sector)
1485                                 break;
1486         }
1487
1488         return &t->targets[(KEYS_PER_NODE * n) + k];
1489 }
1490
1491 static int device_not_poll_capable(struct dm_target *ti, struct dm_dev *dev,
1492                                    sector_t start, sector_t len, void *data)
1493 {
1494         struct request_queue *q = bdev_get_queue(dev->bdev);
1495
1496         return !test_bit(QUEUE_FLAG_POLL, &q->queue_flags);
1497 }
1498
1499 /*
1500  * type->iterate_devices() should be called when the sanity check needs to
1501  * iterate and check all underlying data devices. iterate_devices() will
1502  * iterate all underlying data devices until it encounters a non-zero return
1503  * code, returned by whether the input iterate_devices_callout_fn, or
1504  * iterate_devices() itself internally.
1505  *
1506  * For some target type (e.g. dm-stripe), one call of iterate_devices() may
1507  * iterate multiple underlying devices internally, in which case a non-zero
1508  * return code returned by iterate_devices_callout_fn will stop the iteration
1509  * in advance.
1510  *
1511  * Cases requiring _any_ underlying device supporting some kind of attribute,
1512  * should use the iteration structure like dm_table_any_dev_attr(), or call
1513  * it directly. @func should handle semantics of positive examples, e.g.
1514  * capable of something.
1515  *
1516  * Cases requiring _all_ underlying devices supporting some kind of attribute,
1517  * should use the iteration structure like dm_table_supports_nowait() or
1518  * dm_table_supports_discards(). Or introduce dm_table_all_devs_attr() that
1519  * uses an @anti_func that handle semantics of counter examples, e.g. not
1520  * capable of something. So: return !dm_table_any_dev_attr(t, anti_func, data);
1521  */
1522 static bool dm_table_any_dev_attr(struct dm_table *t,
1523                                   iterate_devices_callout_fn func, void *data)
1524 {
1525         for (unsigned int i = 0; i < t->num_targets; i++) {
1526                 struct dm_target *ti = dm_table_get_target(t, i);
1527
1528                 if (ti->type->iterate_devices &&
1529                     ti->type->iterate_devices(ti, func, data))
1530                         return true;
1531         }
1532
1533         return false;
1534 }
1535
1536 static int count_device(struct dm_target *ti, struct dm_dev *dev,
1537                         sector_t start, sector_t len, void *data)
1538 {
1539         unsigned int *num_devices = data;
1540
1541         (*num_devices)++;
1542
1543         return 0;
1544 }
1545
1546 static bool dm_table_supports_poll(struct dm_table *t)
1547 {
1548         for (unsigned int i = 0; i < t->num_targets; i++) {
1549                 struct dm_target *ti = dm_table_get_target(t, i);
1550
1551                 if (!ti->type->iterate_devices ||
1552                     ti->type->iterate_devices(ti, device_not_poll_capable, NULL))
1553                         return false;
1554         }
1555
1556         return true;
1557 }
1558
1559 /*
1560  * Check whether a table has no data devices attached using each
1561  * target's iterate_devices method.
1562  * Returns false if the result is unknown because a target doesn't
1563  * support iterate_devices.
1564  */
1565 bool dm_table_has_no_data_devices(struct dm_table *t)
1566 {
1567         for (unsigned int i = 0; i < t->num_targets; i++) {
1568                 struct dm_target *ti = dm_table_get_target(t, i);
1569                 unsigned int num_devices = 0;
1570
1571                 if (!ti->type->iterate_devices)
1572                         return false;
1573
1574                 ti->type->iterate_devices(ti, count_device, &num_devices);
1575                 if (num_devices)
1576                         return false;
1577         }
1578
1579         return true;
1580 }
1581
1582 static int device_not_zoned(struct dm_target *ti, struct dm_dev *dev,
1583                             sector_t start, sector_t len, void *data)
1584 {
1585         bool *zoned = data;
1586
1587         return bdev_is_zoned(dev->bdev) != *zoned;
1588 }
1589
1590 static int device_is_zoned_model(struct dm_target *ti, struct dm_dev *dev,
1591                                  sector_t start, sector_t len, void *data)
1592 {
1593         return bdev_is_zoned(dev->bdev);
1594 }
1595
1596 /*
1597  * Check the device zoned model based on the target feature flag. If the target
1598  * has the DM_TARGET_ZONED_HM feature flag set, host-managed zoned devices are
1599  * also accepted but all devices must have the same zoned model. If the target
1600  * has the DM_TARGET_MIXED_ZONED_MODEL feature set, the devices can have any
1601  * zoned model with all zoned devices having the same zone size.
1602  */
1603 static bool dm_table_supports_zoned(struct dm_table *t, bool zoned)
1604 {
1605         for (unsigned int i = 0; i < t->num_targets; i++) {
1606                 struct dm_target *ti = dm_table_get_target(t, i);
1607
1608                 /*
1609                  * For the wildcard target (dm-error), if we do not have a
1610                  * backing device, we must always return false. If we have a
1611                  * backing device, the result must depend on checking zoned
1612                  * model, like for any other target. So for this, check directly
1613                  * if the target backing device is zoned as we get "false" when
1614                  * dm-error was set without a backing device.
1615                  */
1616                 if (dm_target_is_wildcard(ti->type) &&
1617                     !ti->type->iterate_devices(ti, device_is_zoned_model, NULL))
1618                         return false;
1619
1620                 if (dm_target_supports_zoned_hm(ti->type)) {
1621                         if (!ti->type->iterate_devices ||
1622                             ti->type->iterate_devices(ti, device_not_zoned,
1623                                                       &zoned))
1624                                 return false;
1625                 } else if (!dm_target_supports_mixed_zoned_model(ti->type)) {
1626                         if (zoned)
1627                                 return false;
1628                 }
1629         }
1630
1631         return true;
1632 }
1633
1634 static int device_not_matches_zone_sectors(struct dm_target *ti, struct dm_dev *dev,
1635                                            sector_t start, sector_t len, void *data)
1636 {
1637         unsigned int *zone_sectors = data;
1638
1639         if (!bdev_is_zoned(dev->bdev))
1640                 return 0;
1641         return bdev_zone_sectors(dev->bdev) != *zone_sectors;
1642 }
1643
1644 /*
1645  * Check consistency of zoned model and zone sectors across all targets. For
1646  * zone sectors, if the destination device is a zoned block device, it shall
1647  * have the specified zone_sectors.
1648  */
1649 static int validate_hardware_zoned(struct dm_table *t, bool zoned,
1650                                    unsigned int zone_sectors)
1651 {
1652         if (!zoned)
1653                 return 0;
1654
1655         if (!dm_table_supports_zoned(t, zoned)) {
1656                 DMERR("%s: zoned model is not consistent across all devices",
1657                       dm_device_name(t->md));
1658                 return -EINVAL;
1659         }
1660
1661         /* Check zone size validity and compatibility */
1662         if (!zone_sectors || !is_power_of_2(zone_sectors))
1663                 return -EINVAL;
1664
1665         if (dm_table_any_dev_attr(t, device_not_matches_zone_sectors, &zone_sectors)) {
1666                 DMERR("%s: zone sectors is not consistent across all zoned devices",
1667                       dm_device_name(t->md));
1668                 return -EINVAL;
1669         }
1670
1671         return 0;
1672 }
1673
1674 /*
1675  * Establish the new table's queue_limits and validate them.
1676  */
1677 int dm_calculate_queue_limits(struct dm_table *t,
1678                               struct queue_limits *limits)
1679 {
1680         struct queue_limits ti_limits;
1681         unsigned int zone_sectors = 0;
1682         bool zoned = false;
1683
1684         blk_set_stacking_limits(limits);
1685
1686         for (unsigned int i = 0; i < t->num_targets; i++) {
1687                 struct dm_target *ti = dm_table_get_target(t, i);
1688
1689                 blk_set_stacking_limits(&ti_limits);
1690
1691                 if (!ti->type->iterate_devices) {
1692                         /* Set I/O hints portion of queue limits */
1693                         if (ti->type->io_hints)
1694                                 ti->type->io_hints(ti, &ti_limits);
1695                         goto combine_limits;
1696                 }
1697
1698                 /*
1699                  * Combine queue limits of all the devices this target uses.
1700                  */
1701                 ti->type->iterate_devices(ti, dm_set_device_limits,
1702                                           &ti_limits);
1703
1704                 if (!zoned && ti_limits.zoned) {
1705                         /*
1706                          * After stacking all limits, validate all devices
1707                          * in table support this zoned model and zone sectors.
1708                          */
1709                         zoned = ti_limits.zoned;
1710                         zone_sectors = ti_limits.chunk_sectors;
1711                 }
1712
1713                 /* Set I/O hints portion of queue limits */
1714                 if (ti->type->io_hints)
1715                         ti->type->io_hints(ti, &ti_limits);
1716
1717                 /*
1718                  * Check each device area is consistent with the target's
1719                  * overall queue limits.
1720                  */
1721                 if (ti->type->iterate_devices(ti, device_area_is_invalid,
1722                                               &ti_limits))
1723                         return -EINVAL;
1724
1725 combine_limits:
1726                 /*
1727                  * Merge this target's queue limits into the overall limits
1728                  * for the table.
1729                  */
1730                 if (blk_stack_limits(limits, &ti_limits, 0) < 0)
1731                         DMWARN("%s: adding target device (start sect %llu len %llu) "
1732                                "caused an alignment inconsistency",
1733                                dm_device_name(t->md),
1734                                (unsigned long long) ti->begin,
1735                                (unsigned long long) ti->len);
1736         }
1737
1738         /*
1739          * Verify that the zoned model and zone sectors, as determined before
1740          * any .io_hints override, are the same across all devices in the table.
1741          * - this is especially relevant if .io_hints is emulating a disk-managed
1742          *   zoned model on host-managed zoned block devices.
1743          * BUT...
1744          */
1745         if (limits->zoned) {
1746                 /*
1747                  * ...IF the above limits stacking determined a zoned model
1748                  * validate that all of the table's devices conform to it.
1749                  */
1750                 zoned = limits->zoned;
1751                 zone_sectors = limits->chunk_sectors;
1752         }
1753         if (validate_hardware_zoned(t, zoned, zone_sectors))
1754                 return -EINVAL;
1755
1756         return validate_hardware_logical_block_alignment(t, limits);
1757 }
1758
1759 /*
1760  * Verify that all devices have an integrity profile that matches the
1761  * DM device's registered integrity profile.  If the profiles don't
1762  * match then unregister the DM device's integrity profile.
1763  */
1764 static void dm_table_verify_integrity(struct dm_table *t)
1765 {
1766         struct gendisk *template_disk = NULL;
1767
1768         if (t->integrity_added)
1769                 return;
1770
1771         if (t->integrity_supported) {
1772                 /*
1773                  * Verify that the original integrity profile
1774                  * matches all the devices in this table.
1775                  */
1776                 template_disk = dm_table_get_integrity_disk(t);
1777                 if (template_disk &&
1778                     blk_integrity_compare(dm_disk(t->md), template_disk) >= 0)
1779                         return;
1780         }
1781
1782         if (integrity_profile_exists(dm_disk(t->md))) {
1783                 DMWARN("%s: unable to establish an integrity profile",
1784                        dm_device_name(t->md));
1785                 blk_integrity_unregister(dm_disk(t->md));
1786         }
1787 }
1788
1789 static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
1790                                 sector_t start, sector_t len, void *data)
1791 {
1792         unsigned long flush = (unsigned long) data;
1793         struct request_queue *q = bdev_get_queue(dev->bdev);
1794
1795         return (q->queue_flags & flush);
1796 }
1797
1798 static bool dm_table_supports_flush(struct dm_table *t, unsigned long flush)
1799 {
1800         /*
1801          * Require at least one underlying device to support flushes.
1802          * t->devices includes internal dm devices such as mirror logs
1803          * so we need to use iterate_devices here, which targets
1804          * supporting flushes must provide.
1805          */
1806         for (unsigned int i = 0; i < t->num_targets; i++) {
1807                 struct dm_target *ti = dm_table_get_target(t, i);
1808
1809                 if (!ti->num_flush_bios)
1810                         continue;
1811
1812                 if (ti->flush_supported)
1813                         return true;
1814
1815                 if (ti->type->iterate_devices &&
1816                     ti->type->iterate_devices(ti, device_flush_capable, (void *) flush))
1817                         return true;
1818         }
1819
1820         return false;
1821 }
1822
1823 static int device_dax_write_cache_enabled(struct dm_target *ti,
1824                                           struct dm_dev *dev, sector_t start,
1825                                           sector_t len, void *data)
1826 {
1827         struct dax_device *dax_dev = dev->dax_dev;
1828
1829         if (!dax_dev)
1830                 return false;
1831
1832         if (dax_write_cache_enabled(dax_dev))
1833                 return true;
1834         return false;
1835 }
1836
1837 static int device_is_rotational(struct dm_target *ti, struct dm_dev *dev,
1838                                 sector_t start, sector_t len, void *data)
1839 {
1840         return !bdev_nonrot(dev->bdev);
1841 }
1842
1843 static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
1844                              sector_t start, sector_t len, void *data)
1845 {
1846         struct request_queue *q = bdev_get_queue(dev->bdev);
1847
1848         return !blk_queue_add_random(q);
1849 }
1850
1851 static int device_not_write_zeroes_capable(struct dm_target *ti, struct dm_dev *dev,
1852                                            sector_t start, sector_t len, void *data)
1853 {
1854         struct request_queue *q = bdev_get_queue(dev->bdev);
1855
1856         return !q->limits.max_write_zeroes_sectors;
1857 }
1858
1859 static bool dm_table_supports_write_zeroes(struct dm_table *t)
1860 {
1861         for (unsigned int i = 0; i < t->num_targets; i++) {
1862                 struct dm_target *ti = dm_table_get_target(t, i);
1863
1864                 if (!ti->num_write_zeroes_bios)
1865                         return false;
1866
1867                 if (!ti->type->iterate_devices ||
1868                     ti->type->iterate_devices(ti, device_not_write_zeroes_capable, NULL))
1869                         return false;
1870         }
1871
1872         return true;
1873 }
1874
1875 static int device_not_nowait_capable(struct dm_target *ti, struct dm_dev *dev,
1876                                      sector_t start, sector_t len, void *data)
1877 {
1878         return !bdev_nowait(dev->bdev);
1879 }
1880
1881 static bool dm_table_supports_nowait(struct dm_table *t)
1882 {
1883         for (unsigned int i = 0; i < t->num_targets; i++) {
1884                 struct dm_target *ti = dm_table_get_target(t, i);
1885
1886                 if (!dm_target_supports_nowait(ti->type))
1887                         return false;
1888
1889                 if (!ti->type->iterate_devices ||
1890                     ti->type->iterate_devices(ti, device_not_nowait_capable, NULL))
1891                         return false;
1892         }
1893
1894         return true;
1895 }
1896
1897 static int device_not_discard_capable(struct dm_target *ti, struct dm_dev *dev,
1898                                       sector_t start, sector_t len, void *data)
1899 {
1900         return !bdev_max_discard_sectors(dev->bdev);
1901 }
1902
1903 static bool dm_table_supports_discards(struct dm_table *t)
1904 {
1905         for (unsigned int i = 0; i < t->num_targets; i++) {
1906                 struct dm_target *ti = dm_table_get_target(t, i);
1907
1908                 if (!ti->num_discard_bios)
1909                         return false;
1910
1911                 /*
1912                  * Either the target provides discard support (as implied by setting
1913                  * 'discards_supported') or it relies on _all_ data devices having
1914                  * discard support.
1915                  */
1916                 if (!ti->discards_supported &&
1917                     (!ti->type->iterate_devices ||
1918                      ti->type->iterate_devices(ti, device_not_discard_capable, NULL)))
1919                         return false;
1920         }
1921
1922         return true;
1923 }
1924
1925 static int device_not_secure_erase_capable(struct dm_target *ti,
1926                                            struct dm_dev *dev, sector_t start,
1927                                            sector_t len, void *data)
1928 {
1929         return !bdev_max_secure_erase_sectors(dev->bdev);
1930 }
1931
1932 static bool dm_table_supports_secure_erase(struct dm_table *t)
1933 {
1934         for (unsigned int i = 0; i < t->num_targets; i++) {
1935                 struct dm_target *ti = dm_table_get_target(t, i);
1936
1937                 if (!ti->num_secure_erase_bios)
1938                         return false;
1939
1940                 if (!ti->type->iterate_devices ||
1941                     ti->type->iterate_devices(ti, device_not_secure_erase_capable, NULL))
1942                         return false;
1943         }
1944
1945         return true;
1946 }
1947
1948 static int device_requires_stable_pages(struct dm_target *ti,
1949                                         struct dm_dev *dev, sector_t start,
1950                                         sector_t len, void *data)
1951 {
1952         return bdev_stable_writes(dev->bdev);
1953 }
1954
1955 int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1956                               struct queue_limits *limits)
1957 {
1958         bool wc = false, fua = false;
1959         int r;
1960
1961         /*
1962          * Copy table's limits to the DM device's request_queue
1963          */
1964         q->limits = *limits;
1965
1966         if (dm_table_supports_nowait(t))
1967                 blk_queue_flag_set(QUEUE_FLAG_NOWAIT, q);
1968         else
1969                 blk_queue_flag_clear(QUEUE_FLAG_NOWAIT, q);
1970
1971         if (!dm_table_supports_discards(t)) {
1972                 q->limits.max_discard_sectors = 0;
1973                 q->limits.max_hw_discard_sectors = 0;
1974                 q->limits.discard_granularity = 0;
1975                 q->limits.discard_alignment = 0;
1976                 q->limits.discard_misaligned = 0;
1977         }
1978
1979         if (!dm_table_supports_secure_erase(t))
1980                 q->limits.max_secure_erase_sectors = 0;
1981
1982         if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_WC))) {
1983                 wc = true;
1984                 if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_FUA)))
1985                         fua = true;
1986         }
1987         blk_queue_write_cache(q, wc, fua);
1988
1989         if (dm_table_supports_dax(t, device_not_dax_capable)) {
1990                 blk_queue_flag_set(QUEUE_FLAG_DAX, q);
1991                 if (dm_table_supports_dax(t, device_not_dax_synchronous_capable))
1992                         set_dax_synchronous(t->md->dax_dev);
1993         } else
1994                 blk_queue_flag_clear(QUEUE_FLAG_DAX, q);
1995
1996         if (dm_table_any_dev_attr(t, device_dax_write_cache_enabled, NULL))
1997                 dax_write_cache(t->md->dax_dev, true);
1998
1999         /* Ensure that all underlying devices are non-rotational. */
2000         if (dm_table_any_dev_attr(t, device_is_rotational, NULL))
2001                 blk_queue_flag_clear(QUEUE_FLAG_NONROT, q);
2002         else
2003                 blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
2004
2005         if (!dm_table_supports_write_zeroes(t))
2006                 q->limits.max_write_zeroes_sectors = 0;
2007
2008         dm_table_verify_integrity(t);
2009
2010         /*
2011          * Some devices don't use blk_integrity but still want stable pages
2012          * because they do their own checksumming.
2013          * If any underlying device requires stable pages, a table must require
2014          * them as well.  Only targets that support iterate_devices are considered:
2015          * don't want error, zero, etc to require stable pages.
2016          */
2017         if (dm_table_any_dev_attr(t, device_requires_stable_pages, NULL))
2018                 blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, q);
2019         else
2020                 blk_queue_flag_clear(QUEUE_FLAG_STABLE_WRITES, q);
2021
2022         /*
2023          * Determine whether or not this queue's I/O timings contribute
2024          * to the entropy pool, Only request-based targets use this.
2025          * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
2026          * have it set.
2027          */
2028         if (blk_queue_add_random(q) &&
2029             dm_table_any_dev_attr(t, device_is_not_random, NULL))
2030                 blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, q);
2031
2032         /*
2033          * For a zoned target, setup the zones related queue attributes
2034          * and resources necessary for zone append emulation if necessary.
2035          */
2036         if (blk_queue_is_zoned(q)) {
2037                 r = dm_set_zones_restrictions(t, q);
2038                 if (r)
2039                         return r;
2040                 if (!static_key_enabled(&zoned_enabled.key))
2041                         static_branch_enable(&zoned_enabled);
2042         }
2043
2044         dm_update_crypto_profile(q, t);
2045         disk_update_readahead(t->md->disk);
2046
2047         /*
2048          * Check for request-based device is left to
2049          * dm_mq_init_request_queue()->blk_mq_init_allocated_queue().
2050          *
2051          * For bio-based device, only set QUEUE_FLAG_POLL when all
2052          * underlying devices supporting polling.
2053          */
2054         if (__table_type_bio_based(t->type)) {
2055                 if (dm_table_supports_poll(t))
2056                         blk_queue_flag_set(QUEUE_FLAG_POLL, q);
2057                 else
2058                         blk_queue_flag_clear(QUEUE_FLAG_POLL, q);
2059         }
2060
2061         return 0;
2062 }
2063
2064 struct list_head *dm_table_get_devices(struct dm_table *t)
2065 {
2066         return &t->devices;
2067 }
2068
2069 blk_mode_t dm_table_get_mode(struct dm_table *t)
2070 {
2071         return t->mode;
2072 }
2073 EXPORT_SYMBOL(dm_table_get_mode);
2074
2075 enum suspend_mode {
2076         PRESUSPEND,
2077         PRESUSPEND_UNDO,
2078         POSTSUSPEND,
2079 };
2080
2081 static void suspend_targets(struct dm_table *t, enum suspend_mode mode)
2082 {
2083         lockdep_assert_held(&t->md->suspend_lock);
2084
2085         for (unsigned int i = 0; i < t->num_targets; i++) {
2086                 struct dm_target *ti = dm_table_get_target(t, i);
2087
2088                 switch (mode) {
2089                 case PRESUSPEND:
2090                         if (ti->type->presuspend)
2091                                 ti->type->presuspend(ti);
2092                         break;
2093                 case PRESUSPEND_UNDO:
2094                         if (ti->type->presuspend_undo)
2095                                 ti->type->presuspend_undo(ti);
2096                         break;
2097                 case POSTSUSPEND:
2098                         if (ti->type->postsuspend)
2099                                 ti->type->postsuspend(ti);
2100                         break;
2101                 }
2102         }
2103 }
2104
2105 void dm_table_presuspend_targets(struct dm_table *t)
2106 {
2107         if (!t)
2108                 return;
2109
2110         suspend_targets(t, PRESUSPEND);
2111 }
2112
2113 void dm_table_presuspend_undo_targets(struct dm_table *t)
2114 {
2115         if (!t)
2116                 return;
2117
2118         suspend_targets(t, PRESUSPEND_UNDO);
2119 }
2120
2121 void dm_table_postsuspend_targets(struct dm_table *t)
2122 {
2123         if (!t)
2124                 return;
2125
2126         suspend_targets(t, POSTSUSPEND);
2127 }
2128
2129 int dm_table_resume_targets(struct dm_table *t)
2130 {
2131         unsigned int i;
2132         int r = 0;
2133
2134         lockdep_assert_held(&t->md->suspend_lock);
2135
2136         for (i = 0; i < t->num_targets; i++) {
2137                 struct dm_target *ti = dm_table_get_target(t, i);
2138
2139                 if (!ti->type->preresume)
2140                         continue;
2141
2142                 r = ti->type->preresume(ti);
2143                 if (r) {
2144                         DMERR("%s: %s: preresume failed, error = %d",
2145                               dm_device_name(t->md), ti->type->name, r);
2146                         return r;
2147                 }
2148         }
2149
2150         for (i = 0; i < t->num_targets; i++) {
2151                 struct dm_target *ti = dm_table_get_target(t, i);
2152
2153                 if (ti->type->resume)
2154                         ti->type->resume(ti);
2155         }
2156
2157         return 0;
2158 }
2159
2160 struct mapped_device *dm_table_get_md(struct dm_table *t)
2161 {
2162         return t->md;
2163 }
2164 EXPORT_SYMBOL(dm_table_get_md);
2165
2166 const char *dm_table_device_name(struct dm_table *t)
2167 {
2168         return dm_device_name(t->md);
2169 }
2170 EXPORT_SYMBOL_GPL(dm_table_device_name);
2171
2172 void dm_table_run_md_queue_async(struct dm_table *t)
2173 {
2174         if (!dm_table_request_based(t))
2175                 return;
2176
2177         if (t->md->queue)
2178                 blk_mq_run_hw_queues(t->md->queue, true);
2179 }
2180 EXPORT_SYMBOL(dm_table_run_md_queue_async);
2181