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