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                 atomic_set(&dd->count, 0);
 455                 list_add(&dd->list, &t->devices);
 456
 457         } else if (dd->dm_dev->mode != (mode | dd->dm_dev->mode)) {
 458                 r = upgrade_mode(dd, mode, t->md);
 459                 if (r)
 460                         return r;
 461         }
 462         atomic_inc(&dd->count);
 463
 464         *result = dd->dm_dev;
 465         return 0;
 466 }
 467 EXPORT_SYMBOL(dm_get_device);
 468
 469 static int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
 470                                 sector_t start, sector_t len, void *data)
 471 {
 472         struct queue_limits *limits = data;
 473         struct block_device *bdev = dev->bdev;
 474         struct request_queue *q = bdev_get_queue(bdev);
 475         char b[BDEVNAME_SIZE];
 476
 477         if (unlikely(!q)) {
 478                 DMWARN("%s: Cannot set limits for nonexistent device %s",
 479                        dm_device_name(ti->table->md), bdevname(bdev, b));
 480                 return 0;
 481         }
 482
 483         if (bdev_stack_limits(limits, bdev, start) < 0)
 484                 DMWARN("%s: adding target device %s caused an alignment inconsistency: "
 485                        "physical_block_size=%u, logical_block_size=%u, "
 486                        "alignment_offset=%u, start=%llu",
 487                        dm_device_name(ti->table->md), bdevname(bdev, b),
 488                        q->limits.physical_block_size,
 489                        q->limits.logical_block_size,
 490                        q->limits.alignment_offset,
 491                        (unsigned long long) start << SECTOR_SHIFT);
 492
 493         limits->zoned = blk_queue_zoned_model(q);
 494
 495         return 0;
 496 }
 497
 498 /*
 499  * Decrement a device's use count and remove it if necessary.
 500  */
 501 void dm_put_device(struct dm_target *ti, struct dm_dev *d)
 502 {
 503         int found = 0;
 504         struct list_head *devices = &ti->table->devices;
 505         struct dm_dev_internal *dd;
 506
 507         list_for_each_entry(dd, devices, list) {
 508                 if (dd->dm_dev == d) {
 509                         found = 1;
 510                         break;
 511                 }
 512         }
 513         if (!found) {
 514                 DMWARN("%s: device %s not in table devices list",
 515                        dm_device_name(ti->table->md), d->name);
 516                 return;
 517         }
 518         if (atomic_dec_and_test(&dd->count)) {
 519                 dm_put_table_device(ti->table->md, d);
 520                 list_del(&dd->list);
 521                 kfree(dd);
 522         }
 523 }
 524 EXPORT_SYMBOL(dm_put_device);
 525
 526 /*
 527  * Checks to see if the target joins onto the end of the table.
 528  */
 529 static int adjoin(struct dm_table *table, struct dm_target *ti)
 530 {
 531         struct dm_target *prev;
 532
 533         if (!table->num_targets)
 534                 return !ti->begin;
 535
 536         prev = &table->targets[table->num_targets - 1];
 537         return (ti->begin == (prev->begin + prev->len));
 538 }
 539
 540 /*
 541  * Used to dynamically allocate the arg array.
 542  *
 543  * We do first allocation with GFP_NOIO because dm-mpath and dm-thin must
 544  * process messages even if some device is suspended. These messages have a
 545  * small fixed number of arguments.
 546  *
 547  * On the other hand, dm-switch needs to process bulk data using messages and
 548  * excessive use of GFP_NOIO could cause trouble.
 549  */
 550 static char **realloc_argv(unsigned *array_size, char **old_argv)
 551 {
 552         char **argv;
 553         unsigned new_size;
 554         gfp_t gfp;
 555
 556         if (*array_size) {
 557                 new_size = *array_size * 2;
 558                 gfp = GFP_KERNEL;
 559         } else {
 560                 new_size = 8;
 561                 gfp = GFP_NOIO;
 562         }
 563         argv = kmalloc(new_size * sizeof(*argv), gfp);
 564         if (argv) {
 565                 memcpy(argv, old_argv, *array_size * sizeof(*argv));
 566                 *array_size = new_size;
 567         }
 568
 569         kfree(old_argv);
 570         return argv;
 571 }
 572
 573 /*
 574  * Destructively splits up the argument list to pass to ctr.
 575  */
 576 int dm_split_args(int *argc, char ***argvp, char *input)
 577 {
 578         char *start, *end = input, *out, **argv = NULL;
 579         unsigned array_size = 0;
 580
 581         *argc = 0;
 582
 583         if (!input) {
 584                 *argvp = NULL;
 585                 return 0;
 586         }
 587
 588         argv = realloc_argv(&array_size, argv);
 589         if (!argv)
 590                 return -ENOMEM;
 591
 592         while (1) {
 593                 /* Skip whitespace */
 594                 start = skip_spaces(end);
 595
 596                 if (!*start)
 597                         break;  /* success, we hit the end */
 598
 599                 /* 'out' is used to remove any back-quotes */
 600                 end = out = start;
 601                 while (*end) {
 602                         /* Everything apart from '\0' can be quoted */
 603                         if (*end == '\\' && *(end + 1)) {
 604                                 *out++ = *(end + 1);
 605                                 end += 2;
 606                                 continue;
 607                         }
 608
 609                         if (isspace(*end))
 610                                 break;  /* end of token */
 611
 612                         *out++ = *end++;
 613                 }
 614
 615                 /* have we already filled the array ? */
 616                 if ((*argc + 1) > array_size) {
 617                         argv = realloc_argv(&array_size, argv);
 618                         if (!argv)
 619                                 return -ENOMEM;
 620                 }
 621
 622                 /* we know this is whitespace */
 623                 if (*end)
 624                         end++;
 625
 626                 /* terminate the string and put it in the array */
 627                 *out = '\0';
 628                 argv[*argc] = start;
 629                 (*argc)++;
 630         }
 631
 632         *argvp = argv;
 633         return 0;
 634 }
 635
 636 /*
 637  * Impose necessary and sufficient conditions on a devices's table such
 638  * that any incoming bio which respects its logical_block_size can be
 639  * processed successfully.  If it falls across the boundary between
 640  * two or more targets, the size of each piece it gets split into must
 641  * be compatible with the logical_block_size of the target processing it.
 642  */
 643 static int validate_hardware_logical_block_alignment(struct dm_table *table,
 644                                                  struct queue_limits *limits)
 645 {
 646         /*
 647          * This function uses arithmetic modulo the logical_block_size
 648          * (in units of 512-byte sectors).
 649          */
 650         unsigned short device_logical_block_size_sects =
 651                 limits->logical_block_size >> SECTOR_SHIFT;
 652
 653         /*
 654          * Offset of the start of the next table entry, mod logical_block_size.
 655          */
 656         unsigned short next_target_start = 0;
 657
 658         /*
 659          * Given an aligned bio that extends beyond the end of a
 660          * target, how many sectors must the next target handle?
 661          */
 662         unsigned short remaining = 0;
 663
 664         struct dm_target *uninitialized_var(ti);
 665         struct queue_limits ti_limits;
 666         unsigned i;
 667
 668         /*
 669          * Check each entry in the table in turn.
 670          */
 671         for (i = 0; i < dm_table_get_num_targets(table); i++) {
 672                 ti = dm_table_get_target(table, i);
 673
 674                 blk_set_stacking_limits(&ti_limits);
 675
 676                 /* combine all target devices' limits */
 677                 if (ti->type->iterate_devices)
 678                         ti->type->iterate_devices(ti, dm_set_device_limits,
 679                                                   &ti_limits);
 680
 681                 /*
 682                  * If the remaining sectors fall entirely within this
 683                  * table entry are they compatible with its logical_block_size?
 684                  */
 685                 if (remaining < ti->len &&
 686                     remaining & ((ti_limits.logical_block_size >>
 687                                   SECTOR_SHIFT) - 1))
 688                         break;  /* Error */
 689
 690                 next_target_start =
 691                     (unsigned short) ((next_target_start + ti->len) &
 692                                       (device_logical_block_size_sects - 1));
 693                 remaining = next_target_start ?
 694                     device_logical_block_size_sects - next_target_start : 0;
 695         }
 696
 697         if (remaining) {
 698                 DMWARN("%s: table line %u (start sect %llu len %llu) "
 699                        "not aligned to h/w logical block size %u",
 700                        dm_device_name(table->md), i,
 701                        (unsigned long long) ti->begin,
 702                        (unsigned long long) ti->len,
 703                        limits->logical_block_size);
 704                 return -EINVAL;
 705         }
 706
 707         return 0;
 708 }
 709
 710 int dm_table_add_target(struct dm_table *t, const char *type,
 711                         sector_t start, sector_t len, char *params)
 712 {
 713         int r = -EINVAL, argc;
 714         char **argv;
 715         struct dm_target *tgt;
 716
 717         if (t->singleton) {
 718                 DMERR("%s: target type %s must appear alone in table",
 719                       dm_device_name(t->md), t->targets->type->name);
 720                 return -EINVAL;
 721         }
 722
 723         BUG_ON(t->num_targets >= t->num_allocated);
 724
 725         tgt = t->targets + t->num_targets;
 726         memset(tgt, 0, sizeof(*tgt));
 727
 728         if (!len) {
 729                 DMERR("%s: zero-length target", dm_device_name(t->md));
 730                 return -EINVAL;
 731         }
 732
 733         tgt->type = dm_get_target_type(type);
 734         if (!tgt->type) {
 735                 DMERR("%s: %s: unknown target type", dm_device_name(t->md), type);
 736                 return -EINVAL;
 737         }
 738
 739         if (dm_target_needs_singleton(tgt->type)) {
 740                 if (t->num_targets) {
 741                         tgt->error = "singleton target type must appear alone in table";
 742                         goto bad;
 743                 }
 744                 t->singleton = true;
 745         }
 746
 747         if (dm_target_always_writeable(tgt->type) && !(t->mode & FMODE_WRITE)) {
 748                 tgt->error = "target type may not be included in a read-only table";
 749                 goto bad;
 750         }
 751
 752         if (t->immutable_target_type) {
 753                 if (t->immutable_target_type != tgt->type) {
 754                         tgt->error = "immutable target type cannot be mixed with other target types";
 755                         goto bad;
 756                 }
 757         } else if (dm_target_is_immutable(tgt->type)) {
 758                 if (t->num_targets) {
 759                         tgt->error = "immutable target type cannot be mixed with other target types";
 760                         goto bad;
 761                 }
 762                 t->immutable_target_type = tgt->type;
 763         }
 764
 765         if (dm_target_has_integrity(tgt->type))
 766                 t->integrity_added = 1;
 767
 768         tgt->table = t;
 769         tgt->begin = start;
 770         tgt->len = len;
 771         tgt->error = "Unknown error";
 772
 773         /*
 774          * Does this target adjoin the previous one ?
 775          */
 776         if (!adjoin(t, tgt)) {
 777                 tgt->error = "Gap in table";
 778                 goto bad;
 779         }
 780
 781         r = dm_split_args(&argc, &argv, params);
 782         if (r) {
 783                 tgt->error = "couldn't split parameters (insufficient memory)";
 784                 goto bad;
 785         }
 786
 787         r = tgt->type->ctr(tgt, argc, argv);
 788         kfree(argv);
 789         if (r)
 790                 goto bad;
 791
 792         t->highs[t->num_targets++] = tgt->begin + tgt->len - 1;
 793
 794         if (!tgt->num_discard_bios && tgt->discards_supported)
 795                 DMWARN("%s: %s: ignoring discards_supported because num_discard_bios is zero.",
 796                        dm_device_name(t->md), type);
 797
 798         return 0;
 799
 800  bad:
 801         DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error);
 802         dm_put_target_type(tgt->type);
 803         return r;
 804 }
 805
 806 /*
 807  * Target argument parsing helpers.
 808  */
 809 static int validate_next_arg(const struct dm_arg *arg,
 810                              struct dm_arg_set *arg_set,
 811                              unsigned *value, char **error, unsigned grouped)
 812 {
 813         const char *arg_str = dm_shift_arg(arg_set);
 814         char dummy;
 815
 816         if (!arg_str ||
 817             (sscanf(arg_str, "%u%c", value, &dummy) != 1) ||
 818             (*value < arg->min) ||
 819             (*value > arg->max) ||
 820             (grouped && arg_set->argc < *value)) {
 821                 *error = arg->error;
 822                 return -EINVAL;
 823         }
 824
 825         return 0;
 826 }
 827
 828 int dm_read_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
 829                 unsigned *value, char **error)
 830 {
 831         return validate_next_arg(arg, arg_set, value, error, 0);
 832 }
 833 EXPORT_SYMBOL(dm_read_arg);
 834
 835 int dm_read_arg_group(const struct dm_arg *arg, struct dm_arg_set *arg_set,
 836                       unsigned *value, char **error)
 837 {
 838         return validate_next_arg(arg, arg_set, value, error, 1);
 839 }
 840 EXPORT_SYMBOL(dm_read_arg_group);
 841
 842 const char *dm_shift_arg(struct dm_arg_set *as)
 843 {
 844         char *r;
 845
 846         if (as->argc) {
 847                 as->argc--;
 848                 r = *as->argv;
 849                 as->argv++;
 850                 return r;
 851         }
 852
 853         return NULL;
 854 }
 855 EXPORT_SYMBOL(dm_shift_arg);
 856
 857 void dm_consume_args(struct dm_arg_set *as, unsigned num_args)
 858 {
 859         BUG_ON(as->argc < num_args);
 860         as->argc -= num_args;
 861         as->argv += num_args;
 862 }
 863 EXPORT_SYMBOL(dm_consume_args);
 864
 865 static bool __table_type_bio_based(enum dm_queue_mode table_type)
 866 {
 867         return (table_type == DM_TYPE_BIO_BASED ||
 868                 table_type == DM_TYPE_DAX_BIO_BASED);
 869 }
 870
 871 static bool __table_type_request_based(enum dm_queue_mode table_type)
 872 {
 873         return (table_type == DM_TYPE_REQUEST_BASED ||
 874                 table_type == DM_TYPE_MQ_REQUEST_BASED);
 875 }
 876
 877 void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type)
 878 {
 879         t->type = type;
 880 }
 881 EXPORT_SYMBOL_GPL(dm_table_set_type);
 882
 883 static int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,
 884                                sector_t start, sector_t len, void *data)
 885 {
 886         struct request_queue *q = bdev_get_queue(dev->bdev);
 887
 888         return q && blk_queue_dax(q);
 889 }
 890
 891 static bool dm_table_supports_dax(struct dm_table *t)
 892 {
 893         struct dm_target *ti;
 894         unsigned i;
 895
 896         /* Ensure that all targets support DAX. */
 897         for (i = 0; i < dm_table_get_num_targets(t); i++) {
 898                 ti = dm_table_get_target(t, i);
 899
 900                 if (!ti->type->direct_access)
 901                         return false;
 902
 903                 if (!ti->type->iterate_devices ||
 904                     !ti->type->iterate_devices(ti, device_supports_dax, NULL))
 905                         return false;
 906         }
 907
 908         return true;
 909 }
 910
 911 static int dm_table_determine_type(struct dm_table *t)
 912 {
 913         unsigned i;
 914         unsigned bio_based = 0, request_based = 0, hybrid = 0;
 915         unsigned sq_count = 0, mq_count = 0;
 916         struct dm_target *tgt;
 917         struct dm_dev_internal *dd;
 918         struct list_head *devices = dm_table_get_devices(t);
 919         enum dm_queue_mode live_md_type = dm_get_md_type(t->md);
 920
 921         if (t->type != DM_TYPE_NONE) {
 922                 /* target already set the table's type */
 923                 if (t->type == DM_TYPE_BIO_BASED)
 924                         return 0;
 925                 BUG_ON(t->type == DM_TYPE_DAX_BIO_BASED);
 926                 goto verify_rq_based;
 927         }
 928
 929         for (i = 0; i < t->num_targets; i++) {
 930                 tgt = t->targets + i;
 931                 if (dm_target_hybrid(tgt))
 932                         hybrid = 1;
 933                 else if (dm_target_request_based(tgt))
 934                         request_based = 1;
 935                 else
 936                         bio_based = 1;
 937
 938                 if (bio_based && request_based) {
 939                         DMWARN("Inconsistent table: different target types"
 940                                " can't be mixed up");
 941                         return -EINVAL;
 942                 }
 943         }
 944
 945         if (hybrid && !bio_based && !request_based) {
 946                 /*
 947                  * The targets can work either way.
 948                  * Determine the type from the live device.
 949                  * Default to bio-based if device is new.
 950                  */
 951                 if (__table_type_request_based(live_md_type))
 952                         request_based = 1;
 953                 else
 954                         bio_based = 1;
 955         }
 956
 957         if (bio_based) {
 958                 /* We must use this table as bio-based */
 959                 t->type = DM_TYPE_BIO_BASED;
 960                 if (dm_table_supports_dax(t) ||
 961                     (list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED))
 962                         t->type = DM_TYPE_DAX_BIO_BASED;
 963                 return 0;
 964         }
 965
 966         BUG_ON(!request_based); /* No targets in this table */
 967
 968         /*
 969          * The only way to establish DM_TYPE_MQ_REQUEST_BASED is by
 970          * having a compatible target use dm_table_set_type.
 971          */
 972         t->type = DM_TYPE_REQUEST_BASED;
 973
 974 verify_rq_based:
 975         /*
 976          * Request-based dm supports only tables that have a single target now.
 977          * To support multiple targets, request splitting support is needed,
 978          * and that needs lots of changes in the block-layer.
 979          * (e.g. request completion process for partial completion.)
 980          */
 981         if (t->num_targets > 1) {
 982                 DMWARN("Request-based dm doesn't support multiple targets yet");
 983                 return -EINVAL;
 984         }
 985
 986         if (list_empty(devices)) {
 987                 int srcu_idx;
 988                 struct dm_table *live_table = dm_get_live_table(t->md, &srcu_idx);
 989
 990                 /* inherit live table's type and all_blk_mq */
 991                 if (live_table) {
 992                         t->type = live_table->type;
 993                         t->all_blk_mq = live_table->all_blk_mq;
 994                 }
 995                 dm_put_live_table(t->md, srcu_idx);
 996                 return 0;
 997         }
 998
 999         /* Non-request-stackable devices can't be used for request-based dm */
1000         list_for_each_entry(dd, devices, list) {
1001                 struct request_queue *q = bdev_get_queue(dd->dm_dev->bdev);
1002
1003                 if (!blk_queue_stackable(q)) {
1004                         DMERR("table load rejected: including"
1005                               " non-request-stackable devices");
1006                         return -EINVAL;
1007                 }
1008
1009                 if (q->mq_ops)
1010                         mq_count++;
1011                 else
1012                         sq_count++;
1013         }
1014         if (sq_count && mq_count) {
1015                 DMERR("table load rejected: not all devices are blk-mq request-stackable");
1016                 return -EINVAL;
1017         }
1018         t->all_blk_mq = mq_count > 0;
1019
1020         if (t->type == DM_TYPE_MQ_REQUEST_BASED && !t->all_blk_mq) {
1021                 DMERR("table load rejected: all devices are not blk-mq request-stackable");
1022                 return -EINVAL;
1023         }
1024
1025         return 0;
1026 }
1027
1028 enum dm_queue_mode dm_table_get_type(struct dm_table *t)
1029 {
1030         return t->type;
1031 }
1032
1033 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
1034 {
1035         return t->immutable_target_type;
1036 }
1037
1038 struct dm_target *dm_table_get_immutable_target(struct dm_table *t)
1039 {
1040         /* Immutable target is implicitly a singleton */
1041         if (t->num_targets > 1 ||
1042             !dm_target_is_immutable(t->targets[0].type))
1043                 return NULL;
1044
1045         return t->targets;
1046 }
1047
1048 struct dm_target *dm_table_get_wildcard_target(struct dm_table *t)
1049 {
1050         struct dm_target *ti;
1051         unsigned i;
1052
1053         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1054                 ti = dm_table_get_target(t, i);
1055                 if (dm_target_is_wildcard(ti->type))
1056                         return ti;
1057         }
1058
1059         return NULL;
1060 }
1061
1062 bool dm_table_bio_based(struct dm_table *t)
1063 {
1064         return __table_type_bio_based(dm_table_get_type(t));
1065 }
1066
1067 bool dm_table_request_based(struct dm_table *t)
1068 {
1069         return __table_type_request_based(dm_table_get_type(t));
1070 }
1071
1072 bool dm_table_all_blk_mq_devices(struct dm_table *t)
1073 {
1074         return t->all_blk_mq;
1075 }
1076
1077 static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device *md)
1078 {
1079         enum dm_queue_mode type = dm_table_get_type(t);
1080         unsigned per_io_data_size = 0;
1081         struct dm_target *tgt;
1082         unsigned i;
1083
1084         if (unlikely(type == DM_TYPE_NONE)) {
1085                 DMWARN("no table type is set, can't allocate mempools");
1086                 return -EINVAL;
1087         }
1088
1089         if (__table_type_bio_based(type))
1090                 for (i = 0; i < t->num_targets; i++) {
1091                         tgt = t->targets + i;
1092                         per_io_data_size = max(per_io_data_size, tgt->per_io_data_size);
1093                 }
1094
1095         t->mempools = dm_alloc_md_mempools(md, type, t->integrity_supported, per_io_data_size);
1096         if (!t->mempools)
1097                 return -ENOMEM;
1098
1099         return 0;
1100 }
1101
1102 void dm_table_free_md_mempools(struct dm_table *t)
1103 {
1104         dm_free_md_mempools(t->mempools);
1105         t->mempools = NULL;
1106 }
1107
1108 struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t)
1109 {
1110         return t->mempools;
1111 }
1112
1113 static int setup_indexes(struct dm_table *t)
1114 {
1115         int i;
1116         unsigned int total = 0;
1117         sector_t *indexes;
1118
1119         /* allocate the space for *all* the indexes */
1120         for (i = t->depth - 2; i >= 0; i--) {
1121                 t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
1122                 total += t->counts[i];
1123         }
1124
1125         indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE);
1126         if (!indexes)
1127                 return -ENOMEM;
1128
1129         /* set up internal nodes, bottom-up */
1130         for (i = t->depth - 2; i >= 0; i--) {
1131                 t->index[i] = indexes;
1132                 indexes += (KEYS_PER_NODE * t->counts[i]);
1133                 setup_btree_index(i, t);
1134         }
1135
1136         return 0;
1137 }
1138
1139 /*
1140  * Builds the btree to index the map.
1141  */
1142 static int dm_table_build_index(struct dm_table *t)
1143 {
1144         int r = 0;
1145         unsigned int leaf_nodes;
1146
1147         /* how many indexes will the btree have ? */
1148         leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
1149         t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
1150
1151         /* leaf layer has already been set up */
1152         t->counts[t->depth - 1] = leaf_nodes;
1153         t->index[t->depth - 1] = t->highs;
1154
1155         if (t->depth >= 2)
1156                 r = setup_indexes(t);
1157
1158         return r;
1159 }
1160
1161 static bool integrity_profile_exists(struct gendisk *disk)
1162 {
1163         return !!blk_get_integrity(disk);
1164 }
1165
1166 /*
1167  * Get a disk whose integrity profile reflects the table's profile.
1168  * Returns NULL if integrity support was inconsistent or unavailable.
1169  */
1170 static struct gendisk * dm_table_get_integrity_disk(struct dm_table *t)
1171 {
1172         struct list_head *devices = dm_table_get_devices(t);
1173         struct dm_dev_internal *dd = NULL;
1174         struct gendisk *prev_disk = NULL, *template_disk = NULL;
1175         unsigned i;
1176
1177         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1178                 struct dm_target *ti = dm_table_get_target(t, i);
1179                 if (!dm_target_passes_integrity(ti->type))
1180                         goto no_integrity;
1181         }
1182
1183         list_for_each_entry(dd, devices, list) {
1184                 template_disk = dd->dm_dev->bdev->bd_disk;
1185                 if (!integrity_profile_exists(template_disk))
1186                         goto no_integrity;
1187                 else if (prev_disk &&
1188                          blk_integrity_compare(prev_disk, template_disk) < 0)
1189                         goto no_integrity;
1190                 prev_disk = template_disk;
1191         }
1192
1193         return template_disk;
1194
1195 no_integrity:
1196         if (prev_disk)
1197                 DMWARN("%s: integrity not set: %s and %s profile mismatch",
1198                        dm_device_name(t->md),
1199                        prev_disk->disk_name,
1200                        template_disk->disk_name);
1201         return NULL;
1202 }
1203
1204 /*
1205  * Register the mapped device for blk_integrity support if the
1206  * underlying devices have an integrity profile.  But all devices may
1207  * not have matching profiles (checking all devices isn't reliable
1208  * during table load because this table may use other DM device(s) which
1209  * must be resumed before they will have an initialized integity
1210  * profile).  Consequently, stacked DM devices force a 2 stage integrity
1211  * profile validation: First pass during table load, final pass during
1212  * resume.
1213  */
1214 static int dm_table_register_integrity(struct dm_table *t)
1215 {
1216         struct mapped_device *md = t->md;
1217         struct gendisk *template_disk = NULL;
1218
1219         /* If target handles integrity itself do not register it here. */
1220         if (t->integrity_added)
1221                 return 0;
1222
1223         template_disk = dm_table_get_integrity_disk(t);
1224         if (!template_disk)
1225                 return 0;
1226
1227         if (!integrity_profile_exists(dm_disk(md))) {
1228                 t->integrity_supported = true;
1229                 /*
1230                  * Register integrity profile during table load; we can do
1231                  * this because the final profile must match during resume.
1232                  */
1233                 blk_integrity_register(dm_disk(md),
1234                                        blk_get_integrity(template_disk));
1235                 return 0;
1236         }
1237
1238         /*
1239          * If DM device already has an initialized integrity
1240          * profile the new profile should not conflict.
1241          */
1242         if (blk_integrity_compare(dm_disk(md), template_disk) < 0) {
1243                 DMWARN("%s: conflict with existing integrity profile: "
1244                        "%s profile mismatch",
1245                        dm_device_name(t->md),
1246                        template_disk->disk_name);
1247                 return 1;
1248         }
1249
1250         /* Preserve existing integrity profile */
1251         t->integrity_supported = true;
1252         return 0;
1253 }
1254
1255 /*
1256  * Prepares the table for use by building the indices,
1257  * setting the type, and allocating mempools.
1258  */
1259 int dm_table_complete(struct dm_table *t)
1260 {
1261         int r;
1262
1263         r = dm_table_determine_type(t);
1264         if (r) {
1265                 DMERR("unable to determine table type");
1266                 return r;
1267         }
1268
1269         r = dm_table_build_index(t);
1270         if (r) {
1271                 DMERR("unable to build btrees");
1272                 return r;
1273         }
1274
1275         r = dm_table_register_integrity(t);
1276         if (r) {
1277                 DMERR("could not register integrity profile.");
1278                 return r;
1279         }
1280
1281         r = dm_table_alloc_md_mempools(t, t->md);
1282         if (r)
1283                 DMERR("unable to allocate mempools");
1284
1285         return r;
1286 }
1287
1288 static DEFINE_MUTEX(_event_lock);
1289 void dm_table_event_callback(struct dm_table *t,
1290                              void (*fn)(void *), void *context)
1291 {
1292         mutex_lock(&_event_lock);
1293         t->event_fn = fn;
1294         t->event_context = context;
1295         mutex_unlock(&_event_lock);
1296 }
1297
1298 void dm_table_event(struct dm_table *t)
1299 {
1300         /*
1301          * You can no longer call dm_table_event() from interrupt
1302          * context, use a bottom half instead.
1303          */
1304         BUG_ON(in_interrupt());
1305
1306         mutex_lock(&_event_lock);
1307         if (t->event_fn)
1308                 t->event_fn(t->event_context);
1309         mutex_unlock(&_event_lock);
1310 }
1311 EXPORT_SYMBOL(dm_table_event);
1312
1313 sector_t dm_table_get_size(struct dm_table *t)
1314 {
1315         return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1316 }
1317 EXPORT_SYMBOL(dm_table_get_size);
1318
1319 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index)
1320 {
1321         if (index >= t->num_targets)
1322                 return NULL;
1323
1324         return t->targets + index;
1325 }
1326
1327 /*
1328  * Search the btree for the correct target.
1329  *
1330  * Caller should check returned pointer with dm_target_is_valid()
1331  * to trap I/O beyond end of device.
1332  */
1333 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1334 {
1335         unsigned int l, n = 0, k = 0;
1336         sector_t *node;
1337
1338         for (l = 0; l < t->depth; l++) {
1339                 n = get_child(n, k);
1340                 node = get_node(t, l, n);
1341
1342                 for (k = 0; k < KEYS_PER_NODE; k++)
1343                         if (node[k] >= sector)
1344                                 break;
1345         }
1346
1347         return &t->targets[(KEYS_PER_NODE * n) + k];
1348 }
1349
1350 static int count_device(struct dm_target *ti, struct dm_dev *dev,
1351                         sector_t start, sector_t len, void *data)
1352 {
1353         unsigned *num_devices = data;
1354
1355         (*num_devices)++;
1356
1357         return 0;
1358 }
1359
1360 /*
1361  * Check whether a table has no data devices attached using each
1362  * target's iterate_devices method.
1363  * Returns false if the result is unknown because a target doesn't
1364  * support iterate_devices.
1365  */
1366 bool dm_table_has_no_data_devices(struct dm_table *table)
1367 {
1368         struct dm_target *ti;
1369         unsigned i, num_devices;
1370
1371         for (i = 0; i < dm_table_get_num_targets(table); i++) {
1372                 ti = dm_table_get_target(table, i);
1373
1374                 if (!ti->type->iterate_devices)
1375                         return false;
1376
1377                 num_devices = 0;
1378                 ti->type->iterate_devices(ti, count_device, &num_devices);
1379                 if (num_devices)
1380                         return false;
1381         }
1382
1383         return true;
1384 }
1385
1386 static int device_is_zoned_model(struct dm_target *ti, struct dm_dev *dev,
1387                                  sector_t start, sector_t len, void *data)
1388 {
1389         struct request_queue *q = bdev_get_queue(dev->bdev);
1390         enum blk_zoned_model *zoned_model = data;
1391
1392         return q && blk_queue_zoned_model(q) == *zoned_model;
1393 }
1394
1395 static bool dm_table_supports_zoned_model(struct dm_table *t,
1396                                           enum blk_zoned_model zoned_model)
1397 {
1398         struct dm_target *ti;
1399         unsigned i;
1400
1401         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1402                 ti = dm_table_get_target(t, i);
1403
1404                 if (zoned_model == BLK_ZONED_HM &&
1405                     !dm_target_supports_zoned_hm(ti->type))
1406                         return false;
1407
1408                 if (!ti->type->iterate_devices ||
1409                     !ti->type->iterate_devices(ti, device_is_zoned_model, &zoned_model))
1410                         return false;
1411         }
1412
1413         return true;
1414 }
1415
1416 static int device_matches_zone_sectors(struct dm_target *ti, struct dm_dev *dev,
1417                                        sector_t start, sector_t len, void *data)
1418 {
1419         struct request_queue *q = bdev_get_queue(dev->bdev);
1420         unsigned int *zone_sectors = data;
1421
1422         return q && blk_queue_zone_sectors(q) == *zone_sectors;
1423 }
1424
1425 static bool dm_table_matches_zone_sectors(struct dm_table *t,
1426                                           unsigned int zone_sectors)
1427 {
1428         struct dm_target *ti;
1429         unsigned i;
1430
1431         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1432                 ti = dm_table_get_target(t, i);
1433
1434                 if (!ti->type->iterate_devices ||
1435                     !ti->type->iterate_devices(ti, device_matches_zone_sectors, &zone_sectors))
1436                         return false;
1437         }
1438
1439         return true;
1440 }
1441
1442 static int validate_hardware_zoned_model(struct dm_table *table,
1443                                          enum blk_zoned_model zoned_model,
1444                                          unsigned int zone_sectors)
1445 {
1446         if (zoned_model == BLK_ZONED_NONE)
1447                 return 0;
1448
1449         if (!dm_table_supports_zoned_model(table, zoned_model)) {
1450                 DMERR("%s: zoned model is not consistent across all devices",
1451                       dm_device_name(table->md));
1452                 return -EINVAL;
1453         }
1454
1455         /* Check zone size validity and compatibility */
1456         if (!zone_sectors || !is_power_of_2(zone_sectors))
1457                 return -EINVAL;
1458
1459         if (!dm_table_matches_zone_sectors(table, zone_sectors)) {
1460                 DMERR("%s: zone sectors is not consistent across all devices",
1461                       dm_device_name(table->md));
1462                 return -EINVAL;
1463         }
1464
1465         return 0;
1466 }
1467
1468 /*
1469  * Establish the new table's queue_limits and validate them.
1470  */
1471 int dm_calculate_queue_limits(struct dm_table *table,
1472                               struct queue_limits *limits)
1473 {
1474         struct dm_target *ti;
1475         struct queue_limits ti_limits;
1476         unsigned i;
1477         enum blk_zoned_model zoned_model = BLK_ZONED_NONE;
1478         unsigned int zone_sectors = 0;
1479
1480         blk_set_stacking_limits(limits);
1481
1482         for (i = 0; i < dm_table_get_num_targets(table); i++) {
1483                 blk_set_stacking_limits(&ti_limits);
1484
1485                 ti = dm_table_get_target(table, i);
1486
1487                 if (!ti->type->iterate_devices)
1488                         goto combine_limits;
1489
1490                 /*
1491                  * Combine queue limits of all the devices this target uses.
1492                  */
1493                 ti->type->iterate_devices(ti, dm_set_device_limits,
1494                                           &ti_limits);
1495
1496                 if (zoned_model == BLK_ZONED_NONE && ti_limits.zoned != BLK_ZONED_NONE) {
1497                         /*
1498                          * After stacking all limits, validate all devices
1499                          * in table support this zoned model and zone sectors.
1500                          */
1501                         zoned_model = ti_limits.zoned;
1502                         zone_sectors = ti_limits.chunk_sectors;
1503                 }
1504
1505                 /* Set I/O hints portion of queue limits */
1506                 if (ti->type->io_hints)
1507                         ti->type->io_hints(ti, &ti_limits);
1508
1509                 /*
1510                  * Check each device area is consistent with the target's
1511                  * overall queue limits.
1512                  */
1513                 if (ti->type->iterate_devices(ti, device_area_is_invalid,
1514                                               &ti_limits))
1515                         return -EINVAL;
1516
1517 combine_limits:
1518                 /*
1519                  * Merge this target's queue limits into the overall limits
1520                  * for the table.
1521                  */
1522                 if (blk_stack_limits(limits, &ti_limits, 0) < 0)
1523                         DMWARN("%s: adding target device "
1524                                "(start sect %llu len %llu) "
1525                                "caused an alignment inconsistency",
1526                                dm_device_name(table->md),
1527                                (unsigned long long) ti->begin,
1528                                (unsigned long long) ti->len);
1529
1530                 /*
1531                  * FIXME: this should likely be moved to blk_stack_limits(), would
1532                  * also eliminate limits->zoned stacking hack in dm_set_device_limits()
1533                  */
1534                 if (limits->zoned == BLK_ZONED_NONE && ti_limits.zoned != BLK_ZONED_NONE) {
1535                         /*
1536                          * By default, the stacked limits zoned model is set to
1537                          * BLK_ZONED_NONE in blk_set_stacking_limits(). Update
1538                          * this model using the first target model reported
1539                          * that is not BLK_ZONED_NONE. This will be either the
1540                          * first target device zoned model or the model reported
1541                          * by the target .io_hints.
1542                          */
1543                         limits->zoned = ti_limits.zoned;
1544                 }
1545         }
1546
1547         /*
1548          * Verify that the zoned model and zone sectors, as determined before
1549          * any .io_hints override, are the same across all devices in the table.
1550          * - this is especially relevant if .io_hints is emulating a disk-managed
1551          *   zoned model (aka BLK_ZONED_NONE) on host-managed zoned block devices.
1552          * BUT...
1553          */
1554         if (limits->zoned != BLK_ZONED_NONE) {
1555                 /*
1556                  * ...IF the above limits stacking determined a zoned model
1557                  * validate that all of the table's devices conform to it.
1558                  */
1559                 zoned_model = limits->zoned;
1560                 zone_sectors = limits->chunk_sectors;
1561         }
1562         if (validate_hardware_zoned_model(table, zoned_model, zone_sectors))
1563                 return -EINVAL;
1564
1565         return validate_hardware_logical_block_alignment(table, limits);
1566 }
1567
1568 /*
1569  * Verify that all devices have an integrity profile that matches the
1570  * DM device's registered integrity profile.  If the profiles don't
1571  * match then unregister the DM device's integrity profile.
1572  */
1573 static void dm_table_verify_integrity(struct dm_table *t)
1574 {
1575         struct gendisk *template_disk = NULL;
1576
1577         if (t->integrity_added)
1578                 return;
1579
1580         if (t->integrity_supported) {
1581                 /*
1582                  * Verify that the original integrity profile
1583                  * matches all the devices in this table.
1584                  */
1585                 template_disk = dm_table_get_integrity_disk(t);
1586                 if (template_disk &&
1587                     blk_integrity_compare(dm_disk(t->md), template_disk) >= 0)
1588                         return;
1589         }
1590
1591         if (integrity_profile_exists(dm_disk(t->md))) {
1592                 DMWARN("%s: unable to establish an integrity profile",
1593                        dm_device_name(t->md));
1594                 blk_integrity_unregister(dm_disk(t->md));
1595         }
1596 }
1597
1598 static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
1599                                 sector_t start, sector_t len, void *data)
1600 {
1601         unsigned long flush = (unsigned long) data;
1602         struct request_queue *q = bdev_get_queue(dev->bdev);
1603
1604         return q && (q->queue_flags & flush);
1605 }
1606
1607 static bool dm_table_supports_flush(struct dm_table *t, unsigned long flush)
1608 {
1609         struct dm_target *ti;
1610         unsigned i;
1611
1612         /*
1613          * Require at least one underlying device to support flushes.
1614          * t->devices includes internal dm devices such as mirror logs
1615          * so we need to use iterate_devices here, which targets
1616          * supporting flushes must provide.
1617          */
1618         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1619                 ti = dm_table_get_target(t, i);
1620
1621                 if (!ti->num_flush_bios)
1622                         continue;
1623
1624                 if (ti->flush_supported)
1625                         return true;
1626
1627                 if (ti->type->iterate_devices &&
1628                     ti->type->iterate_devices(ti, device_flush_capable, (void *) flush))
1629                         return true;
1630         }
1631
1632         return false;
1633 }
1634
1635 static int device_dax_write_cache_enabled(struct dm_target *ti,
1636                                           struct dm_dev *dev, sector_t start,
1637                                           sector_t len, void *data)
1638 {
1639         struct dax_device *dax_dev = dev->dax_dev;
1640
1641         if (!dax_dev)
1642                 return false;
1643
1644         if (dax_write_cache_enabled(dax_dev))
1645                 return true;
1646         return false;
1647 }
1648
1649 static int dm_table_supports_dax_write_cache(struct dm_table *t)
1650 {
1651         struct dm_target *ti;
1652         unsigned i;
1653
1654         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1655                 ti = dm_table_get_target(t, i);
1656
1657                 if (ti->type->iterate_devices &&
1658                     ti->type->iterate_devices(ti,
1659                                 device_dax_write_cache_enabled, NULL))
1660                         return true;
1661         }
1662
1663         return false;
1664 }
1665
1666 static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev,
1667                             sector_t start, sector_t len, void *data)
1668 {
1669         struct request_queue *q = bdev_get_queue(dev->bdev);
1670
1671         return q && blk_queue_nonrot(q);
1672 }
1673
1674 static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
1675                              sector_t start, sector_t len, void *data)
1676 {
1677         struct request_queue *q = bdev_get_queue(dev->bdev);
1678
1679         return q && !blk_queue_add_random(q);
1680 }
1681
1682 static int queue_supports_sg_merge(struct dm_target *ti, struct dm_dev *dev,
1683                                    sector_t start, sector_t len, void *data)
1684 {
1685         struct request_queue *q = bdev_get_queue(dev->bdev);
1686
1687         return q && !test_bit(QUEUE_FLAG_NO_SG_MERGE, &q->queue_flags);
1688 }
1689
1690 static bool dm_table_all_devices_attribute(struct dm_table *t,
1691                                            iterate_devices_callout_fn func)
1692 {
1693         struct dm_target *ti;
1694         unsigned i;
1695
1696         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1697                 ti = dm_table_get_target(t, i);
1698
1699                 if (!ti->type->iterate_devices ||
1700                     !ti->type->iterate_devices(ti, func, NULL))
1701                         return false;
1702         }
1703
1704         return true;
1705 }
1706
1707 static int device_not_write_same_capable(struct dm_target *ti, struct dm_dev *dev,
1708                                          sector_t start, sector_t len, void *data)
1709 {
1710         struct request_queue *q = bdev_get_queue(dev->bdev);
1711
1712         return q && !q->limits.max_write_same_sectors;
1713 }
1714
1715 static bool dm_table_supports_write_same(struct dm_table *t)
1716 {
1717         struct dm_target *ti;
1718         unsigned i;
1719
1720         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1721                 ti = dm_table_get_target(t, i);
1722
1723                 if (!ti->num_write_same_bios)
1724                         return false;
1725
1726                 if (!ti->type->iterate_devices ||
1727                     ti->type->iterate_devices(ti, device_not_write_same_capable, NULL))
1728                         return false;
1729         }
1730
1731         return true;
1732 }
1733
1734 static int device_not_write_zeroes_capable(struct dm_target *ti, struct dm_dev *dev,
1735                                            sector_t start, sector_t len, void *data)
1736 {
1737         struct request_queue *q = bdev_get_queue(dev->bdev);
1738
1739         return q && !q->limits.max_write_zeroes_sectors;
1740 }
1741
1742 static bool dm_table_supports_write_zeroes(struct dm_table *t)
1743 {
1744         struct dm_target *ti;
1745         unsigned i = 0;
1746
1747         while (i < dm_table_get_num_targets(t)) {
1748                 ti = dm_table_get_target(t, i++);
1749
1750                 if (!ti->num_write_zeroes_bios)
1751                         return false;
1752
1753                 if (!ti->type->iterate_devices ||
1754                     ti->type->iterate_devices(ti, device_not_write_zeroes_capable, NULL))
1755                         return false;
1756         }
1757
1758         return true;
1759 }
1760
1761
1762 static int device_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         /*
1776          * Unless any target used by the table set discards_supported,
1777          * require at least one underlying device to support discards.
1778          * t->devices includes internal dm devices such as mirror logs
1779          * so we need to use iterate_devices here, which targets
1780          * supporting discard selectively must provide.
1781          */
1782         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1783                 ti = dm_table_get_target(t, i);
1784
1785                 if (!ti->num_discard_bios)
1786                         continue;
1787
1788                 if (ti->discards_supported)
1789                         return true;
1790
1791                 if (ti->type->iterate_devices &&
1792                     ti->type->iterate_devices(ti, device_discard_capable, NULL))
1793                         return true;
1794         }
1795
1796         return false;
1797 }
1798
1799 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1800                                struct queue_limits *limits)
1801 {
1802         bool wc = false, fua = false;
1803
1804         /*
1805          * Copy table's limits to the DM device's request_queue
1806          */
1807         q->limits = *limits;
1808
1809         if (!dm_table_supports_discards(t))
1810                 queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q);
1811         else
1812                 queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
1813
1814         if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_WC))) {
1815                 wc = true;
1816                 if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_FUA)))
1817                         fua = true;
1818         }
1819         blk_queue_write_cache(q, wc, fua);
1820
1821         if (dm_table_supports_dax_write_cache(t))
1822                 dax_write_cache(t->md->dax_dev, true);
1823
1824         /* Ensure that all underlying devices are non-rotational. */
1825         if (dm_table_all_devices_attribute(t, device_is_nonrot))
1826                 queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
1827         else
1828                 queue_flag_clear_unlocked(QUEUE_FLAG_NONROT, q);
1829
1830         if (!dm_table_supports_write_same(t))
1831                 q->limits.max_write_same_sectors = 0;
1832         if (!dm_table_supports_write_zeroes(t))
1833                 q->limits.max_write_zeroes_sectors = 0;
1834
1835         if (dm_table_all_devices_attribute(t, queue_supports_sg_merge))
1836                 queue_flag_clear_unlocked(QUEUE_FLAG_NO_SG_MERGE, q);
1837         else
1838                 queue_flag_set_unlocked(QUEUE_FLAG_NO_SG_MERGE, q);
1839
1840         dm_table_verify_integrity(t);
1841
1842         /*
1843          * Determine whether or not this queue's I/O timings contribute
1844          * to the entropy pool, Only request-based targets use this.
1845          * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
1846          * have it set.
1847          */
1848         if (blk_queue_add_random(q) && dm_table_all_devices_attribute(t, device_is_not_random))
1849                 queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, q);
1850
1851         /*
1852          * QUEUE_FLAG_STACKABLE must be set after all queue settings are
1853          * visible to other CPUs because, once the flag is set, incoming bios
1854          * are processed by request-based dm, which refers to the queue
1855          * settings.
1856          * Until the flag set, bios are passed to bio-based dm and queued to
1857          * md->deferred where queue settings are not needed yet.
1858          * Those bios are passed to request-based dm at the resume time.
1859          */
1860         smp_mb();
1861         if (dm_table_request_based(t))
1862                 queue_flag_set_unlocked(QUEUE_FLAG_STACKABLE, q);
1863 }
1864
1865 unsigned int dm_table_get_num_targets(struct dm_table *t)
1866 {
1867         return t->num_targets;
1868 }
1869
1870 struct list_head *dm_table_get_devices(struct dm_table *t)
1871 {
1872         return &t->devices;
1873 }
1874
1875 fmode_t dm_table_get_mode(struct dm_table *t)
1876 {
1877         return t->mode;
1878 }
1879 EXPORT_SYMBOL(dm_table_get_mode);
1880
1881 enum suspend_mode {
1882         PRESUSPEND,
1883         PRESUSPEND_UNDO,
1884         POSTSUSPEND,
1885 };
1886
1887 static void suspend_targets(struct dm_table *t, enum suspend_mode mode)
1888 {
1889         int i = t->num_targets;
1890         struct dm_target *ti = t->targets;
1891
1892         lockdep_assert_held(&t->md->suspend_lock);
1893
1894         while (i--) {
1895                 switch (mode) {
1896                 case PRESUSPEND:
1897                         if (ti->type->presuspend)
1898                                 ti->type->presuspend(ti);
1899                         break;
1900                 case PRESUSPEND_UNDO:
1901                         if (ti->type->presuspend_undo)
1902                                 ti->type->presuspend_undo(ti);
1903                         break;
1904                 case POSTSUSPEND:
1905                         if (ti->type->postsuspend)
1906                                 ti->type->postsuspend(ti);
1907                         break;
1908                 }
1909                 ti++;
1910         }
1911 }
1912
1913 void dm_table_presuspend_targets(struct dm_table *t)
1914 {
1915         if (!t)
1916                 return;
1917
1918         suspend_targets(t, PRESUSPEND);
1919 }
1920
1921 void dm_table_presuspend_undo_targets(struct dm_table *t)
1922 {
1923         if (!t)
1924                 return;
1925
1926         suspend_targets(t, PRESUSPEND_UNDO);
1927 }
1928
1929 void dm_table_postsuspend_targets(struct dm_table *t)
1930 {
1931         if (!t)
1932                 return;
1933
1934         suspend_targets(t, POSTSUSPEND);
1935 }
1936
1937 int dm_table_resume_targets(struct dm_table *t)
1938 {
1939         int i, r = 0;
1940
1941         lockdep_assert_held(&t->md->suspend_lock);
1942
1943         for (i = 0; i < t->num_targets; i++) {
1944                 struct dm_target *ti = t->targets + i;
1945
1946                 if (!ti->type->preresume)
1947                         continue;
1948
1949                 r = ti->type->preresume(ti);
1950                 if (r) {
1951                         DMERR("%s: %s: preresume failed, error = %d",
1952                               dm_device_name(t->md), ti->type->name, r);
1953                         return r;
1954                 }
1955         }
1956
1957         for (i = 0; i < t->num_targets; i++) {
1958                 struct dm_target *ti = t->targets + i;
1959
1960                 if (ti->type->resume)
1961                         ti->type->resume(ti);
1962         }
1963
1964         return 0;
1965 }
1966
1967 void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb)
1968 {
1969         list_add(&cb->list, &t->target_callbacks);
1970 }
1971 EXPORT_SYMBOL_GPL(dm_table_add_target_callbacks);
1972
1973 int dm_table_any_congested(struct dm_table *t, int bdi_bits)
1974 {
1975         struct dm_dev_internal *dd;
1976         struct list_head *devices = dm_table_get_devices(t);
1977         struct dm_target_callbacks *cb;
1978         int r = 0;
1979
1980         list_for_each_entry(dd, devices, list) {
1981                 struct request_queue *q = bdev_get_queue(dd->dm_dev->bdev);
1982                 char b[BDEVNAME_SIZE];
1983
1984                 if (likely(q))
1985                         r |= bdi_congested(q->backing_dev_info, bdi_bits);
1986                 else
1987                         DMWARN_LIMIT("%s: any_congested: nonexistent device %s",
1988                                      dm_device_name(t->md),
1989                                      bdevname(dd->dm_dev->bdev, b));
1990         }
1991
1992         list_for_each_entry(cb, &t->target_callbacks, list)
1993                 if (cb->congested_fn)
1994                         r |= cb->congested_fn(cb, bdi_bits);
1995
1996         return r;
1997 }
1998
1999 struct mapped_device *dm_table_get_md(struct dm_table *t)
2000 {
2001         return t->md;
2002 }
2003 EXPORT_SYMBOL(dm_table_get_md);
2004
2005 void dm_table_run_md_queue_async(struct dm_table *t)
2006 {
2007         struct mapped_device *md;
2008         struct request_queue *queue;
2009         unsigned long flags;
2010
2011         if (!dm_table_request_based(t))
2012                 return;
2013
2014         md = dm_table_get_md(t);
2015         queue = dm_get_md_queue(md);
2016         if (queue) {
2017                 if (queue->mq_ops)
2018                         blk_mq_run_hw_queues(queue, true);
2019                 else {
2020                         spin_lock_irqsave(queue->queue_lock, flags);
2021                         blk_run_queue_async(queue);
2022                         spin_unlock_irqrestore(queue->queue_lock, flags);
2023                 }
2024         }
2025 }
2026 EXPORT_SYMBOL(dm_table_run_md_queue_async);
2027