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         unsigned integrity_added:1;
  51
  52         /*
  53          * Indicates the rw permissions for the new logical
  54          * device.  This should be a combination of FMODE_READ
  55          * and FMODE_WRITE.
  56          */
  57         fmode_t mode;
  58
  59         /* a list of devices used by this table */
  60         struct list_head devices;
  61
  62         /* events get handed up using this callback */
  63         void (*event_fn)(void *);
  64         void *event_context;
  65
  66         struct dm_md_mempools *mempools;
  67
  68         struct list_head target_callbacks;
  69 };
  70
  71 /*
  72  * Similar to ceiling(log_size(n))
  73  */
  74 static unsigned int int_log(unsigned int n, unsigned int base)
  75 {
  76         int result = 0;
  77
  78         while (n > 1) {
  79                 n = dm_div_up(n, base);
  80                 result++;
  81         }
  82
  83         return result;
  84 }
  85
  86 /*
  87  * Calculate the index of the child node of the n'th node k'th key.
  88  */
  89 static inline unsigned int get_child(unsigned int n, unsigned int k)
  90 {
  91         return (n * CHILDREN_PER_NODE) + k;
  92 }
  93
  94 /*
  95  * Return the n'th node of level l from table t.
  96  */
  97 static inline sector_t *get_node(struct dm_table *t,
  98                                  unsigned int l, unsigned int n)
  99 {
 100         return t->index[l] + (n * KEYS_PER_NODE);
 101 }
 102
 103 /*
 104  * Return the highest key that you could lookup from the n'th
 105  * node on level l of the btree.
 106  */
 107 static sector_t high(struct dm_table *t, unsigned int l, unsigned int n)
 108 {
 109         for (; l < t->depth - 1; l++)
 110                 n = get_child(n, CHILDREN_PER_NODE - 1);
 111
 112         if (n >= t->counts[l])
 113                 return (sector_t) - 1;
 114
 115         return get_node(t, l, n)[KEYS_PER_NODE - 1];
 116 }
 117
 118 /*
 119  * Fills in a level of the btree based on the highs of the level
 120  * below it.
 121  */
 122 static int setup_btree_index(unsigned int l, struct dm_table *t)
 123 {
 124         unsigned int n, k;
 125         sector_t *node;
 126
 127         for (n = 0U; n < t->counts[l]; n++) {
 128                 node = get_node(t, l, n);
 129
 130                 for (k = 0U; k < KEYS_PER_NODE; k++)
 131                         node[k] = high(t, l + 1, get_child(n, k));
 132         }
 133
 134         return 0;
 135 }
 136
 137 void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size)
 138 {
 139         unsigned long size;
 140         void *addr;
 141
 142         /*
 143          * Check that we're not going to overflow.
 144          */
 145         if (nmemb > (ULONG_MAX / elem_size))
 146                 return NULL;
 147
 148         size = nmemb * elem_size;
 149         addr = vzalloc(size);
 150
 151         return addr;
 152 }
 153 EXPORT_SYMBOL(dm_vcalloc);
 154
 155 /*
 156  * highs, and targets are managed as dynamic arrays during a
 157  * table load.
 158  */
 159 static int alloc_targets(struct dm_table *t, unsigned int num)
 160 {
 161         sector_t *n_highs;
 162         struct dm_target *n_targets;
 163
 164         /*
 165          * Allocate both the target array and offset array at once.
 166          * Append an empty entry to catch sectors beyond the end of
 167          * the device.
 168          */
 169         n_highs = (sector_t *) dm_vcalloc(num + 1, sizeof(struct dm_target) +
 170                                           sizeof(sector_t));
 171         if (!n_highs)
 172                 return -ENOMEM;
 173
 174         n_targets = (struct dm_target *) (n_highs + num);
 175
 176         memset(n_highs, -1, sizeof(*n_highs) * num);
 177         vfree(t->highs);
 178
 179         t->num_allocated = num;
 180         t->highs = n_highs;
 181         t->targets = n_targets;
 182
 183         return 0;
 184 }
 185
 186 int dm_table_create(struct dm_table **result, fmode_t mode,
 187                     unsigned num_targets, struct mapped_device *md)
 188 {
 189         struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
 190
 191         if (!t)
 192                 return -ENOMEM;
 193
 194         INIT_LIST_HEAD(&t->devices);
 195         INIT_LIST_HEAD(&t->target_callbacks);
 196
 197         if (!num_targets)
 198                 num_targets = KEYS_PER_NODE;
 199
 200         num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
 201
 202         if (!num_targets) {
 203                 kfree(t);
 204                 return -ENOMEM;
 205         }
 206
 207         if (alloc_targets(t, num_targets)) {
 208                 kfree(t);
 209                 return -ENOMEM;
 210         }
 211
 212         t->type = DM_TYPE_NONE;
 213         t->mode = mode;
 214         t->md = md;
 215         *result = t;
 216         return 0;
 217 }
 218
 219 static void free_devices(struct list_head *devices, struct mapped_device *md)
 220 {
 221         struct list_head *tmp, *next;
 222
 223         list_for_each_safe(tmp, next, devices) {
 224                 struct dm_dev_internal *dd =
 225                     list_entry(tmp, struct dm_dev_internal, list);
 226                 DMWARN("%s: dm_table_destroy: dm_put_device call missing for %s",
 227                        dm_device_name(md), dd->dm_dev->name);
 228                 dm_put_table_device(md, dd->dm_dev);
 229                 kfree(dd);
 230         }
 231 }
 232
 233 void dm_table_destroy(struct dm_table *t)
 234 {
 235         unsigned int i;
 236
 237         if (!t)
 238                 return;
 239
 240         /* free the indexes */
 241         if (t->depth >= 2)
 242                 vfree(t->index[t->depth - 2]);
 243
 244         /* free the targets */
 245         for (i = 0; i < t->num_targets; i++) {
 246                 struct dm_target *tgt = t->targets + i;
 247
 248                 if (tgt->type->dtr)
 249                         tgt->type->dtr(tgt);
 250
 251                 dm_put_target_type(tgt->type);
 252         }
 253
 254         vfree(t->highs);
 255
 256         /* free the device list */
 257         free_devices(&t->devices, t->md);
 258
 259         dm_free_md_mempools(t->mempools);
 260
 261         kfree(t);
 262 }
 263
 264 /*
 265  * See if we've already got a device in the list.
 266  */
 267 static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
 268 {
 269         struct dm_dev_internal *dd;
 270
 271         list_for_each_entry (dd, l, list)
 272                 if (dd->dm_dev->bdev->bd_dev == dev)
 273                         return dd;
 274
 275         return NULL;
 276 }
 277
 278 /*
 279  * If possible, this checks an area of a destination device is invalid.
 280  */
 281 static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
 282                                   sector_t start, sector_t len, void *data)
 283 {
 284         struct request_queue *q;
 285         struct queue_limits *limits = data;
 286         struct block_device *bdev = dev->bdev;
 287         sector_t dev_size =
 288                 i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
 289         unsigned short logical_block_size_sectors =
 290                 limits->logical_block_size >> SECTOR_SHIFT;
 291         char b[BDEVNAME_SIZE];
 292
 293         /*
 294          * Some devices exist without request functions,
 295          * such as loop devices not yet bound to backing files.
 296          * Forbid the use of such devices.
 297          */
 298         q = bdev_get_queue(bdev);
 299         if (!q || !q->make_request_fn) {
 300                 DMWARN("%s: %s is not yet initialised: "
 301                        "start=%llu, len=%llu, dev_size=%llu",
 302                        dm_device_name(ti->table->md), bdevname(bdev, b),
 303                        (unsigned long long)start,
 304                        (unsigned long long)len,
 305                        (unsigned long long)dev_size);
 306                 return 1;
 307         }
 308
 309         if (!dev_size)
 310                 return 0;
 311
 312         if ((start >= dev_size) || (start + len > dev_size)) {
 313                 DMWARN("%s: %s too small for target: "
 314                        "start=%llu, len=%llu, dev_size=%llu",
 315                        dm_device_name(ti->table->md), bdevname(bdev, b),
 316                        (unsigned long long)start,
 317                        (unsigned long long)len,
 318                        (unsigned long long)dev_size);
 319                 return 1;
 320         }
 321
 322         /*
 323          * If the target is mapped to zoned block device(s), check
 324          * that the zones are not partially mapped.
 325          */
 326         if (bdev_zoned_model(bdev) != BLK_ZONED_NONE) {
 327                 unsigned int zone_sectors = bdev_zone_sectors(bdev);
 328
 329                 if (start & (zone_sectors - 1)) {
 330                         DMWARN("%s: start=%llu not aligned to h/w zone size %u of %s",
 331                                dm_device_name(ti->table->md),
 332                                (unsigned long long)start,
 333                                zone_sectors, bdevname(bdev, b));
 334                         return 1;
 335                 }
 336
 337                 /*
 338                  * Note: The last zone of a zoned block device may be smaller
 339                  * than other zones. So for a target mapping the end of a
 340                  * zoned block device with such a zone, len would not be zone
 341                  * aligned. We do not allow such last smaller zone to be part
 342                  * of the mapping here to ensure that mappings with multiple
 343                  * devices do not end up with a smaller zone in the middle of
 344                  * the sector range.
 345                  */
 346                 if (len & (zone_sectors - 1)) {
 347                         DMWARN("%s: len=%llu not aligned to h/w zone size %u of %s",
 348                                dm_device_name(ti->table->md),
 349                                (unsigned long long)len,
 350                                zone_sectors, bdevname(bdev, b));
 351                         return 1;
 352                 }
 353         }
 354
 355         if (logical_block_size_sectors <= 1)
 356                 return 0;
 357
 358         if (start & (logical_block_size_sectors - 1)) {
 359                 DMWARN("%s: start=%llu not aligned to h/w "
 360                        "logical block size %u of %s",
 361                        dm_device_name(ti->table->md),
 362                        (unsigned long long)start,
 363                        limits->logical_block_size, bdevname(bdev, b));
 364                 return 1;
 365         }
 366
 367         if (len & (logical_block_size_sectors - 1)) {
 368                 DMWARN("%s: len=%llu not aligned to h/w "
 369                        "logical block size %u of %s",
 370                        dm_device_name(ti->table->md),
 371                        (unsigned long long)len,
 372                        limits->logical_block_size, bdevname(bdev, b));
 373                 return 1;
 374         }
 375
 376         return 0;
 377 }
 378
 379 /*
 380  * This upgrades the mode on an already open dm_dev, being
 381  * careful to leave things as they were if we fail to reopen the
 382  * device and not to touch the existing bdev field in case
 383  * it is accessed concurrently inside dm_table_any_congested().
 384  */
 385 static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
 386                         struct mapped_device *md)
 387 {
 388         int r;
 389         struct dm_dev *old_dev, *new_dev;
 390
 391         old_dev = dd->dm_dev;
 392
 393         r = dm_get_table_device(md, dd->dm_dev->bdev->bd_dev,
 394                                 dd->dm_dev->mode | new_mode, &new_dev);
 395         if (r)
 396                 return r;
 397
 398         dd->dm_dev = new_dev;
 399         dm_put_table_device(md, old_dev);
 400
 401         return 0;
 402 }
 403
 404 /*
 405  * Convert the path to a device
 406  */
 407 dev_t dm_get_dev_t(const char *path)
 408 {
 409         dev_t dev;
 410         struct block_device *bdev;
 411
 412         bdev = lookup_bdev(path);
 413         if (IS_ERR(bdev))
 414                 dev = name_to_dev_t(path);
 415         else {
 416                 dev = bdev->bd_dev;
 417                 bdput(bdev);
 418         }
 419
 420         return dev;
 421 }
 422 EXPORT_SYMBOL_GPL(dm_get_dev_t);
 423
 424 /*
 425  * Add a device to the list, or just increment the usage count if
 426  * it's already present.
 427  */
 428 int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
 429                   struct dm_dev **result)
 430 {
 431         int r;
 432         dev_t dev;
 433         struct dm_dev_internal *dd;
 434         struct dm_table *t = ti->table;
 435
 436         BUG_ON(!t);
 437
 438         dev = dm_get_dev_t(path);
 439         if (!dev)
 440                 return -ENODEV;
 441
 442         dd = find_device(&t->devices, dev);
 443         if (!dd) {
 444                 dd = kmalloc(sizeof(*dd), GFP_KERNEL);
 445                 if (!dd)
 446                         return -ENOMEM;
 447
 448                 if ((r = dm_get_table_device(t->md, dev, mode, &dd->dm_dev))) {
 449                         kfree(dd);
 450                         return r;
 451                 }
 452
 453                 refcount_set(&dd->count, 1);
 454                 list_add(&dd->list, &t->devices);
 455                 goto out;
 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         refcount_inc(&dd->count);
 463 out:
 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 (refcount_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 *size, char **old_argv)
 551 {
 552         char **argv;
 553         unsigned new_size;
 554         gfp_t gfp;
 555
 556         if (*size) {
 557                 new_size = *size * 2;
 558                 gfp = GFP_KERNEL;
 559         } else {
 560                 new_size = 8;
 561                 gfp = GFP_NOIO;
 562         }
 563         argv = kmalloc_array(new_size, sizeof(*argv), gfp);
 564         if (argv && old_argv) {
 565                 memcpy(argv, old_argv, *size * sizeof(*argv));
 566                 *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                 table_type == DM_TYPE_NVME_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 }
 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 /* validate the dax capability of the target device span */
 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         int blocksize = *(int *) data;
 888
 889         return generic_fsdax_supported(dev->dax_dev, dev->bdev, blocksize,
 890                         start, len);
 891 }
 892
 893 bool dm_table_supports_dax(struct dm_table *t, int blocksize)
 894 {
 895         struct dm_target *ti;
 896         unsigned i;
 897
 898         /* Ensure that all targets support DAX. */
 899         for (i = 0; i < dm_table_get_num_targets(t); i++) {
 900                 ti = dm_table_get_target(t, i);
 901
 902                 if (!ti->type->direct_access)
 903                         return false;
 904
 905                 if (!ti->type->iterate_devices ||
 906                     !ti->type->iterate_devices(ti, device_supports_dax,
 907                             &blocksize))
 908                         return false;
 909         }
 910
 911         return true;
 912 }
 913
 914 static bool dm_table_does_not_support_partial_completion(struct dm_table *t);
 915
 916 struct verify_rq_based_data {
 917         unsigned sq_count;
 918         unsigned mq_count;
 919 };
 920
 921 static int device_is_rq_based(struct dm_target *ti, struct dm_dev *dev,
 922                               sector_t start, sector_t len, void *data)
 923 {
 924         struct request_queue *q = bdev_get_queue(dev->bdev);
 925         struct verify_rq_based_data *v = data;
 926
 927         if (queue_is_mq(q))
 928                 v->mq_count++;
 929         else
 930                 v->sq_count++;
 931
 932         return queue_is_mq(q);
 933 }
 934
 935 static int dm_table_determine_type(struct dm_table *t)
 936 {
 937         unsigned i;
 938         unsigned bio_based = 0, request_based = 0, hybrid = 0;
 939         struct verify_rq_based_data v = {.sq_count = 0, .mq_count = 0};
 940         struct dm_target *tgt;
 941         struct list_head *devices = dm_table_get_devices(t);
 942         enum dm_queue_mode live_md_type = dm_get_md_type(t->md);
 943
 944         if (t->type != DM_TYPE_NONE) {
 945                 /* target already set the table's type */
 946                 if (t->type == DM_TYPE_BIO_BASED) {
 947                         /* possibly upgrade to a variant of bio-based */
 948                         goto verify_bio_based;
 949                 }
 950                 BUG_ON(t->type == DM_TYPE_DAX_BIO_BASED);
 951                 BUG_ON(t->type == DM_TYPE_NVME_BIO_BASED);
 952                 goto verify_rq_based;
 953         }
 954
 955         for (i = 0; i < t->num_targets; i++) {
 956                 tgt = t->targets + i;
 957                 if (dm_target_hybrid(tgt))
 958                         hybrid = 1;
 959                 else if (dm_target_request_based(tgt))
 960                         request_based = 1;
 961                 else
 962                         bio_based = 1;
 963
 964                 if (bio_based && request_based) {
 965                         DMERR("Inconsistent table: different target types"
 966                               " can't be mixed up");
 967                         return -EINVAL;
 968                 }
 969         }
 970
 971         if (hybrid && !bio_based && !request_based) {
 972                 /*
 973                  * The targets can work either way.
 974                  * Determine the type from the live device.
 975                  * Default to bio-based if device is new.
 976                  */
 977                 if (__table_type_request_based(live_md_type))
 978                         request_based = 1;
 979                 else
 980                         bio_based = 1;
 981         }
 982
 983         if (bio_based) {
 984 verify_bio_based:
 985                 /* We must use this table as bio-based */
 986                 t->type = DM_TYPE_BIO_BASED;
 987                 if (dm_table_supports_dax(t, PAGE_SIZE) ||
 988                     (list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED)) {
 989                         t->type = DM_TYPE_DAX_BIO_BASED;
 990                 } else {
 991                         /* Check if upgrading to NVMe bio-based is valid or required */
 992                         tgt = dm_table_get_immutable_target(t);
 993                         if (tgt && !tgt->max_io_len && dm_table_does_not_support_partial_completion(t)) {
 994                                 t->type = DM_TYPE_NVME_BIO_BASED;
 995                                 goto verify_rq_based; /* must be stacked directly on NVMe (blk-mq) */
 996                         } else if (list_empty(devices) && live_md_type == DM_TYPE_NVME_BIO_BASED) {
 997                                 t->type = DM_TYPE_NVME_BIO_BASED;
 998                         }
 999                 }
1000                 return 0;
1001         }
1002
1003         BUG_ON(!request_based); /* No targets in this table */
1004
1005         t->type = DM_TYPE_REQUEST_BASED;
1006
1007 verify_rq_based:
1008         /*
1009          * Request-based dm supports only tables that have a single target now.
1010          * To support multiple targets, request splitting support is needed,
1011          * and that needs lots of changes in the block-layer.
1012          * (e.g. request completion process for partial completion.)
1013          */
1014         if (t->num_targets > 1) {
1015                 DMERR("%s DM doesn't support multiple targets",
1016                       t->type == DM_TYPE_NVME_BIO_BASED ? "nvme bio-based" : "request-based");
1017                 return -EINVAL;
1018         }
1019
1020         if (list_empty(devices)) {
1021                 int srcu_idx;
1022                 struct dm_table *live_table = dm_get_live_table(t->md, &srcu_idx);
1023
1024                 /* inherit live table's type */
1025                 if (live_table)
1026                         t->type = live_table->type;
1027                 dm_put_live_table(t->md, srcu_idx);
1028                 return 0;
1029         }
1030
1031         tgt = dm_table_get_immutable_target(t);
1032         if (!tgt) {
1033                 DMERR("table load rejected: immutable target is required");
1034                 return -EINVAL;
1035         } else if (tgt->max_io_len) {
1036                 DMERR("table load rejected: immutable target that splits IO is not supported");
1037                 return -EINVAL;
1038         }
1039
1040         /* Non-request-stackable devices can't be used for request-based dm */
1041         if (!tgt->type->iterate_devices ||
1042             !tgt->type->iterate_devices(tgt, device_is_rq_based, &v)) {
1043                 DMERR("table load rejected: including non-request-stackable devices");
1044                 return -EINVAL;
1045         }
1046         if (v.sq_count > 0) {
1047                 DMERR("table load rejected: not all devices are blk-mq request-stackable");
1048                 return -EINVAL;
1049         }
1050
1051         return 0;
1052 }
1053
1054 enum dm_queue_mode dm_table_get_type(struct dm_table *t)
1055 {
1056         return t->type;
1057 }
1058
1059 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
1060 {
1061         return t->immutable_target_type;
1062 }
1063
1064 struct dm_target *dm_table_get_immutable_target(struct dm_table *t)
1065 {
1066         /* Immutable target is implicitly a singleton */
1067         if (t->num_targets > 1 ||
1068             !dm_target_is_immutable(t->targets[0].type))
1069                 return NULL;
1070
1071         return t->targets;
1072 }
1073
1074 struct dm_target *dm_table_get_wildcard_target(struct dm_table *t)
1075 {
1076         struct dm_target *ti;
1077         unsigned i;
1078
1079         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1080                 ti = dm_table_get_target(t, i);
1081                 if (dm_target_is_wildcard(ti->type))
1082                         return ti;
1083         }
1084
1085         return NULL;
1086 }
1087
1088 bool dm_table_bio_based(struct dm_table *t)
1089 {
1090         return __table_type_bio_based(dm_table_get_type(t));
1091 }
1092
1093 bool dm_table_request_based(struct dm_table *t)
1094 {
1095         return __table_type_request_based(dm_table_get_type(t));
1096 }
1097
1098 static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device *md)
1099 {
1100         enum dm_queue_mode type = dm_table_get_type(t);
1101         unsigned per_io_data_size = 0;
1102         unsigned min_pool_size = 0;
1103         struct dm_target *ti;
1104         unsigned i;
1105
1106         if (unlikely(type == DM_TYPE_NONE)) {
1107                 DMWARN("no table type is set, can't allocate mempools");
1108                 return -EINVAL;
1109         }
1110
1111         if (__table_type_bio_based(type))
1112                 for (i = 0; i < t->num_targets; i++) {
1113                         ti = t->targets + i;
1114                         per_io_data_size = max(per_io_data_size, ti->per_io_data_size);
1115                         min_pool_size = max(min_pool_size, ti->num_flush_bios);
1116                 }
1117
1118         t->mempools = dm_alloc_md_mempools(md, type, t->integrity_supported,
1119                                            per_io_data_size, min_pool_size);
1120         if (!t->mempools)
1121                 return -ENOMEM;
1122
1123         return 0;
1124 }
1125
1126 void dm_table_free_md_mempools(struct dm_table *t)
1127 {
1128         dm_free_md_mempools(t->mempools);
1129         t->mempools = NULL;
1130 }
1131
1132 struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t)
1133 {
1134         return t->mempools;
1135 }
1136
1137 static int setup_indexes(struct dm_table *t)
1138 {
1139         int i;
1140         unsigned int total = 0;
1141         sector_t *indexes;
1142
1143         /* allocate the space for *all* the indexes */
1144         for (i = t->depth - 2; i >= 0; i--) {
1145                 t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
1146                 total += t->counts[i];
1147         }
1148
1149         indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE);
1150         if (!indexes)
1151                 return -ENOMEM;
1152
1153         /* set up internal nodes, bottom-up */
1154         for (i = t->depth - 2; i >= 0; i--) {
1155                 t->index[i] = indexes;
1156                 indexes += (KEYS_PER_NODE * t->counts[i]);
1157                 setup_btree_index(i, t);
1158         }
1159
1160         return 0;
1161 }
1162
1163 /*
1164  * Builds the btree to index the map.
1165  */
1166 static int dm_table_build_index(struct dm_table *t)
1167 {
1168         int r = 0;
1169         unsigned int leaf_nodes;
1170
1171         /* how many indexes will the btree have ? */
1172         leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
1173         t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
1174
1175         /* leaf layer has already been set up */
1176         t->counts[t->depth - 1] = leaf_nodes;
1177         t->index[t->depth - 1] = t->highs;
1178
1179         if (t->depth >= 2)
1180                 r = setup_indexes(t);
1181
1182         return r;
1183 }
1184
1185 static bool integrity_profile_exists(struct gendisk *disk)
1186 {
1187         return !!blk_get_integrity(disk);
1188 }
1189
1190 /*
1191  * Get a disk whose integrity profile reflects the table's profile.
1192  * Returns NULL if integrity support was inconsistent or unavailable.
1193  */
1194 static struct gendisk * dm_table_get_integrity_disk(struct dm_table *t)
1195 {
1196         struct list_head *devices = dm_table_get_devices(t);
1197         struct dm_dev_internal *dd = NULL;
1198         struct gendisk *prev_disk = NULL, *template_disk = NULL;
1199         unsigned i;
1200
1201         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1202                 struct dm_target *ti = dm_table_get_target(t, i);
1203                 if (!dm_target_passes_integrity(ti->type))
1204                         goto no_integrity;
1205         }
1206
1207         list_for_each_entry(dd, devices, list) {
1208                 template_disk = dd->dm_dev->bdev->bd_disk;
1209                 if (!integrity_profile_exists(template_disk))
1210                         goto no_integrity;
1211                 else if (prev_disk &&
1212                          blk_integrity_compare(prev_disk, template_disk) < 0)
1213                         goto no_integrity;
1214                 prev_disk = template_disk;
1215         }
1216
1217         return template_disk;
1218
1219 no_integrity:
1220         if (prev_disk)
1221                 DMWARN("%s: integrity not set: %s and %s profile mismatch",
1222                        dm_device_name(t->md),
1223                        prev_disk->disk_name,
1224                        template_disk->disk_name);
1225         return NULL;
1226 }
1227
1228 /*
1229  * Register the mapped device for blk_integrity support if the
1230  * underlying devices have an integrity profile.  But all devices may
1231  * not have matching profiles (checking all devices isn't reliable
1232  * during table load because this table may use other DM device(s) which
1233  * must be resumed before they will have an initialized integity
1234  * profile).  Consequently, stacked DM devices force a 2 stage integrity
1235  * profile validation: First pass during table load, final pass during
1236  * resume.
1237  */
1238 static int dm_table_register_integrity(struct dm_table *t)
1239 {
1240         struct mapped_device *md = t->md;
1241         struct gendisk *template_disk = NULL;
1242
1243         /* If target handles integrity itself do not register it here. */
1244         if (t->integrity_added)
1245                 return 0;
1246
1247         template_disk = dm_table_get_integrity_disk(t);
1248         if (!template_disk)
1249                 return 0;
1250
1251         if (!integrity_profile_exists(dm_disk(md))) {
1252                 t->integrity_supported = true;
1253                 /*
1254                  * Register integrity profile during table load; we can do
1255                  * this because the final profile must match during resume.
1256                  */
1257                 blk_integrity_register(dm_disk(md),
1258                                        blk_get_integrity(template_disk));
1259                 return 0;
1260         }
1261
1262         /*
1263          * If DM device already has an initialized integrity
1264          * profile the new profile should not conflict.
1265          */
1266         if (blk_integrity_compare(dm_disk(md), template_disk) < 0) {
1267                 DMWARN("%s: conflict with existing integrity profile: "
1268                        "%s profile mismatch",
1269                        dm_device_name(t->md),
1270                        template_disk->disk_name);
1271                 return 1;
1272         }
1273
1274         /* Preserve existing integrity profile */
1275         t->integrity_supported = true;
1276         return 0;
1277 }
1278
1279 /*
1280  * Prepares the table for use by building the indices,
1281  * setting the type, and allocating mempools.
1282  */
1283 int dm_table_complete(struct dm_table *t)
1284 {
1285         int r;
1286
1287         r = dm_table_determine_type(t);
1288         if (r) {
1289                 DMERR("unable to determine table type");
1290                 return r;
1291         }
1292
1293         r = dm_table_build_index(t);
1294         if (r) {
1295                 DMERR("unable to build btrees");
1296                 return r;
1297         }
1298
1299         r = dm_table_register_integrity(t);
1300         if (r) {
1301                 DMERR("could not register integrity profile.");
1302                 return r;
1303         }
1304
1305         r = dm_table_alloc_md_mempools(t, t->md);
1306         if (r)
1307                 DMERR("unable to allocate mempools");
1308
1309         return r;
1310 }
1311
1312 static DEFINE_MUTEX(_event_lock);
1313 void dm_table_event_callback(struct dm_table *t,
1314                              void (*fn)(void *), void *context)
1315 {
1316         mutex_lock(&_event_lock);
1317         t->event_fn = fn;
1318         t->event_context = context;
1319         mutex_unlock(&_event_lock);
1320 }
1321
1322 void dm_table_event(struct dm_table *t)
1323 {
1324         /*
1325          * You can no longer call dm_table_event() from interrupt
1326          * context, use a bottom half instead.
1327          */
1328         BUG_ON(in_interrupt());
1329
1330         mutex_lock(&_event_lock);
1331         if (t->event_fn)
1332                 t->event_fn(t->event_context);
1333         mutex_unlock(&_event_lock);
1334 }
1335 EXPORT_SYMBOL(dm_table_event);
1336
1337 sector_t dm_table_get_size(struct dm_table *t)
1338 {
1339         return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1340 }
1341 EXPORT_SYMBOL(dm_table_get_size);
1342
1343 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index)
1344 {
1345         if (index >= t->num_targets)
1346                 return NULL;
1347
1348         return t->targets + index;
1349 }
1350
1351 /*
1352  * Search the btree for the correct target.
1353  *
1354  * Caller should check returned pointer with dm_target_is_valid()
1355  * to trap I/O beyond end of device.
1356  */
1357 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1358 {
1359         unsigned int l, n = 0, k = 0;
1360         sector_t *node;
1361
1362         for (l = 0; l < t->depth; l++) {
1363                 n = get_child(n, k);
1364                 node = get_node(t, l, n);
1365
1366                 for (k = 0; k < KEYS_PER_NODE; k++)
1367                         if (node[k] >= sector)
1368                                 break;
1369         }
1370
1371         return &t->targets[(KEYS_PER_NODE * n) + k];
1372 }
1373
1374 static int count_device(struct dm_target *ti, struct dm_dev *dev,
1375                         sector_t start, sector_t len, void *data)
1376 {
1377         unsigned *num_devices = data;
1378
1379         (*num_devices)++;
1380
1381         return 0;
1382 }
1383
1384 /*
1385  * Check whether a table has no data devices attached using each
1386  * target's iterate_devices method.
1387  * Returns false if the result is unknown because a target doesn't
1388  * support iterate_devices.
1389  */
1390 bool dm_table_has_no_data_devices(struct dm_table *table)
1391 {
1392         struct dm_target *ti;
1393         unsigned i, num_devices;
1394
1395         for (i = 0; i < dm_table_get_num_targets(table); i++) {
1396                 ti = dm_table_get_target(table, i);
1397
1398                 if (!ti->type->iterate_devices)
1399                         return false;
1400
1401                 num_devices = 0;
1402                 ti->type->iterate_devices(ti, count_device, &num_devices);
1403                 if (num_devices)
1404                         return false;
1405         }
1406
1407         return true;
1408 }
1409
1410 static int device_is_zoned_model(struct dm_target *ti, struct dm_dev *dev,
1411                                  sector_t start, sector_t len, void *data)
1412 {
1413         struct request_queue *q = bdev_get_queue(dev->bdev);
1414         enum blk_zoned_model *zoned_model = data;
1415
1416         return q && blk_queue_zoned_model(q) == *zoned_model;
1417 }
1418
1419 static bool dm_table_supports_zoned_model(struct dm_table *t,
1420                                           enum blk_zoned_model zoned_model)
1421 {
1422         struct dm_target *ti;
1423         unsigned i;
1424
1425         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1426                 ti = dm_table_get_target(t, i);
1427
1428                 if (zoned_model == BLK_ZONED_HM &&
1429                     !dm_target_supports_zoned_hm(ti->type))
1430                         return false;
1431
1432                 if (!ti->type->iterate_devices ||
1433                     !ti->type->iterate_devices(ti, device_is_zoned_model, &zoned_model))
1434                         return false;
1435         }
1436
1437         return true;
1438 }
1439
1440 static int device_matches_zone_sectors(struct dm_target *ti, struct dm_dev *dev,
1441                                        sector_t start, sector_t len, void *data)
1442 {
1443         struct request_queue *q = bdev_get_queue(dev->bdev);
1444         unsigned int *zone_sectors = data;
1445
1446         return q && blk_queue_zone_sectors(q) == *zone_sectors;
1447 }
1448
1449 static bool dm_table_matches_zone_sectors(struct dm_table *t,
1450                                           unsigned int zone_sectors)
1451 {
1452         struct dm_target *ti;
1453         unsigned i;
1454
1455         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1456                 ti = dm_table_get_target(t, i);
1457
1458                 if (!ti->type->iterate_devices ||
1459                     !ti->type->iterate_devices(ti, device_matches_zone_sectors, &zone_sectors))
1460                         return false;
1461         }
1462
1463         return true;
1464 }
1465
1466 static int validate_hardware_zoned_model(struct dm_table *table,
1467                                          enum blk_zoned_model zoned_model,
1468                                          unsigned int zone_sectors)
1469 {
1470         if (zoned_model == BLK_ZONED_NONE)
1471                 return 0;
1472
1473         if (!dm_table_supports_zoned_model(table, zoned_model)) {
1474                 DMERR("%s: zoned model is not consistent across all devices",
1475                       dm_device_name(table->md));
1476                 return -EINVAL;
1477         }
1478
1479         /* Check zone size validity and compatibility */
1480         if (!zone_sectors || !is_power_of_2(zone_sectors))
1481                 return -EINVAL;
1482
1483         if (!dm_table_matches_zone_sectors(table, zone_sectors)) {
1484                 DMERR("%s: zone sectors is not consistent across all devices",
1485                       dm_device_name(table->md));
1486                 return -EINVAL;
1487         }
1488
1489         return 0;
1490 }
1491
1492 /*
1493  * Establish the new table's queue_limits and validate them.
1494  */
1495 int dm_calculate_queue_limits(struct dm_table *table,
1496                               struct queue_limits *limits)
1497 {
1498         struct dm_target *ti;
1499         struct queue_limits ti_limits;
1500         unsigned i;
1501         enum blk_zoned_model zoned_model = BLK_ZONED_NONE;
1502         unsigned int zone_sectors = 0;
1503
1504         blk_set_stacking_limits(limits);
1505
1506         for (i = 0; i < dm_table_get_num_targets(table); i++) {
1507                 blk_set_stacking_limits(&ti_limits);
1508
1509                 ti = dm_table_get_target(table, i);
1510
1511                 if (!ti->type->iterate_devices)
1512                         goto combine_limits;
1513
1514                 /*
1515                  * Combine queue limits of all the devices this target uses.
1516                  */
1517                 ti->type->iterate_devices(ti, dm_set_device_limits,
1518                                           &ti_limits);
1519
1520                 if (zoned_model == BLK_ZONED_NONE && ti_limits.zoned != BLK_ZONED_NONE) {
1521                         /*
1522                          * After stacking all limits, validate all devices
1523                          * in table support this zoned model and zone sectors.
1524                          */
1525                         zoned_model = ti_limits.zoned;
1526                         zone_sectors = ti_limits.chunk_sectors;
1527                 }
1528
1529                 /* Set I/O hints portion of queue limits */
1530                 if (ti->type->io_hints)
1531                         ti->type->io_hints(ti, &ti_limits);
1532
1533                 /*
1534                  * Check each device area is consistent with the target's
1535                  * overall queue limits.
1536                  */
1537                 if (ti->type->iterate_devices(ti, device_area_is_invalid,
1538                                               &ti_limits))
1539                         return -EINVAL;
1540
1541 combine_limits:
1542                 /*
1543                  * Merge this target's queue limits into the overall limits
1544                  * for the table.
1545                  */
1546                 if (blk_stack_limits(limits, &ti_limits, 0) < 0)
1547                         DMWARN("%s: adding target device "
1548                                "(start sect %llu len %llu) "
1549                                "caused an alignment inconsistency",
1550                                dm_device_name(table->md),
1551                                (unsigned long long) ti->begin,
1552                                (unsigned long long) ti->len);
1553
1554                 /*
1555                  * FIXME: this should likely be moved to blk_stack_limits(), would
1556                  * also eliminate limits->zoned stacking hack in dm_set_device_limits()
1557                  */
1558                 if (limits->zoned == BLK_ZONED_NONE && ti_limits.zoned != BLK_ZONED_NONE) {
1559                         /*
1560                          * By default, the stacked limits zoned model is set to
1561                          * BLK_ZONED_NONE in blk_set_stacking_limits(). Update
1562                          * this model using the first target model reported
1563                          * that is not BLK_ZONED_NONE. This will be either the
1564                          * first target device zoned model or the model reported
1565                          * by the target .io_hints.
1566                          */
1567                         limits->zoned = ti_limits.zoned;
1568                 }
1569         }
1570
1571         /*
1572          * Verify that the zoned model and zone sectors, as determined before
1573          * any .io_hints override, are the same across all devices in the table.
1574          * - this is especially relevant if .io_hints is emulating a disk-managed
1575          *   zoned model (aka BLK_ZONED_NONE) on host-managed zoned block devices.
1576          * BUT...
1577          */
1578         if (limits->zoned != BLK_ZONED_NONE) {
1579                 /*
1580                  * ...IF the above limits stacking determined a zoned model
1581                  * validate that all of the table's devices conform to it.
1582                  */
1583                 zoned_model = limits->zoned;
1584                 zone_sectors = limits->chunk_sectors;
1585         }
1586         if (validate_hardware_zoned_model(table, zoned_model, zone_sectors))
1587                 return -EINVAL;
1588
1589         return validate_hardware_logical_block_alignment(table, limits);
1590 }
1591
1592 /*
1593  * Verify that all devices have an integrity profile that matches the
1594  * DM device's registered integrity profile.  If the profiles don't
1595  * match then unregister the DM device's integrity profile.
1596  */
1597 static void dm_table_verify_integrity(struct dm_table *t)
1598 {
1599         struct gendisk *template_disk = NULL;
1600
1601         if (t->integrity_added)
1602                 return;
1603
1604         if (t->integrity_supported) {
1605                 /*
1606                  * Verify that the original integrity profile
1607                  * matches all the devices in this table.
1608                  */
1609                 template_disk = dm_table_get_integrity_disk(t);
1610                 if (template_disk &&
1611                     blk_integrity_compare(dm_disk(t->md), template_disk) >= 0)
1612                         return;
1613         }
1614
1615         if (integrity_profile_exists(dm_disk(t->md))) {
1616                 DMWARN("%s: unable to establish an integrity profile",
1617                        dm_device_name(t->md));
1618                 blk_integrity_unregister(dm_disk(t->md));
1619         }
1620 }
1621
1622 static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
1623                                 sector_t start, sector_t len, void *data)
1624 {
1625         unsigned long flush = (unsigned long) data;
1626         struct request_queue *q = bdev_get_queue(dev->bdev);
1627
1628         return q && (q->queue_flags & flush);
1629 }
1630
1631 static bool dm_table_supports_flush(struct dm_table *t, unsigned long flush)
1632 {
1633         struct dm_target *ti;
1634         unsigned i;
1635
1636         /*
1637          * Require at least one underlying device to support flushes.
1638          * t->devices includes internal dm devices such as mirror logs
1639          * so we need to use iterate_devices here, which targets
1640          * supporting flushes must provide.
1641          */
1642         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1643                 ti = dm_table_get_target(t, i);
1644
1645                 if (!ti->num_flush_bios)
1646                         continue;
1647
1648                 if (ti->flush_supported)
1649                         return true;
1650
1651                 if (ti->type->iterate_devices &&
1652                     ti->type->iterate_devices(ti, device_flush_capable, (void *) flush))
1653                         return true;
1654         }
1655
1656         return false;
1657 }
1658
1659 static int device_dax_write_cache_enabled(struct dm_target *ti,
1660                                           struct dm_dev *dev, sector_t start,
1661                                           sector_t len, void *data)
1662 {
1663         struct dax_device *dax_dev = dev->dax_dev;
1664
1665         if (!dax_dev)
1666                 return false;
1667
1668         if (dax_write_cache_enabled(dax_dev))
1669                 return true;
1670         return false;
1671 }
1672
1673 static int dm_table_supports_dax_write_cache(struct dm_table *t)
1674 {
1675         struct dm_target *ti;
1676         unsigned i;
1677
1678         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1679                 ti = dm_table_get_target(t, i);
1680
1681                 if (ti->type->iterate_devices &&
1682                     ti->type->iterate_devices(ti,
1683                                 device_dax_write_cache_enabled, NULL))
1684                         return true;
1685         }
1686
1687         return false;
1688 }
1689
1690 static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev,
1691                             sector_t start, sector_t len, void *data)
1692 {
1693         struct request_queue *q = bdev_get_queue(dev->bdev);
1694
1695         return q && blk_queue_nonrot(q);
1696 }
1697
1698 static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
1699                              sector_t start, sector_t len, void *data)
1700 {
1701         struct request_queue *q = bdev_get_queue(dev->bdev);
1702
1703         return q && !blk_queue_add_random(q);
1704 }
1705
1706 static bool dm_table_all_devices_attribute(struct dm_table *t,
1707                                            iterate_devices_callout_fn func)
1708 {
1709         struct dm_target *ti;
1710         unsigned i;
1711
1712         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1713                 ti = dm_table_get_target(t, i);
1714
1715                 if (!ti->type->iterate_devices ||
1716                     !ti->type->iterate_devices(ti, func, NULL))
1717                         return false;
1718         }
1719
1720         return true;
1721 }
1722
1723 static int device_no_partial_completion(struct dm_target *ti, struct dm_dev *dev,
1724                                         sector_t start, sector_t len, void *data)
1725 {
1726         char b[BDEVNAME_SIZE];
1727
1728         /* For now, NVMe devices are the only devices of this class */
1729         return (strncmp(bdevname(dev->bdev, b), "nvme", 4) == 0);
1730 }
1731
1732 static bool dm_table_does_not_support_partial_completion(struct dm_table *t)
1733 {
1734         return dm_table_all_devices_attribute(t, device_no_partial_completion);
1735 }
1736
1737 static int device_not_write_same_capable(struct dm_target *ti, struct dm_dev *dev,
1738                                          sector_t start, sector_t len, void *data)
1739 {
1740         struct request_queue *q = bdev_get_queue(dev->bdev);
1741
1742         return q && !q->limits.max_write_same_sectors;
1743 }
1744
1745 static bool dm_table_supports_write_same(struct dm_table *t)
1746 {
1747         struct dm_target *ti;
1748         unsigned i;
1749
1750         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1751                 ti = dm_table_get_target(t, i);
1752
1753                 if (!ti->num_write_same_bios)
1754                         return false;
1755
1756                 if (!ti->type->iterate_devices ||
1757                     ti->type->iterate_devices(ti, device_not_write_same_capable, NULL))
1758                         return false;
1759         }
1760
1761         return true;
1762 }
1763
1764 static int device_not_write_zeroes_capable(struct dm_target *ti, struct dm_dev *dev,
1765                                            sector_t start, sector_t len, void *data)
1766 {
1767         struct request_queue *q = bdev_get_queue(dev->bdev);
1768
1769         return q && !q->limits.max_write_zeroes_sectors;
1770 }
1771
1772 static bool dm_table_supports_write_zeroes(struct dm_table *t)
1773 {
1774         struct dm_target *ti;
1775         unsigned i = 0;
1776
1777         while (i < dm_table_get_num_targets(t)) {
1778                 ti = dm_table_get_target(t, i++);
1779
1780                 if (!ti->num_write_zeroes_bios)
1781                         return false;
1782
1783                 if (!ti->type->iterate_devices ||
1784                     ti->type->iterate_devices(ti, device_not_write_zeroes_capable, NULL))
1785                         return false;
1786         }
1787
1788         return true;
1789 }
1790
1791 static int device_not_discard_capable(struct dm_target *ti, struct dm_dev *dev,
1792                                       sector_t start, sector_t len, void *data)
1793 {
1794         struct request_queue *q = bdev_get_queue(dev->bdev);
1795
1796         return q && !blk_queue_discard(q);
1797 }
1798
1799 static bool dm_table_supports_discards(struct dm_table *t)
1800 {
1801         struct dm_target *ti;
1802         unsigned i;
1803
1804         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1805                 ti = dm_table_get_target(t, i);
1806
1807                 if (!ti->num_discard_bios)
1808                         return false;
1809
1810                 /*
1811                  * Either the target provides discard support (as implied by setting
1812                  * 'discards_supported') or it relies on _all_ data devices having
1813                  * discard support.
1814                  */
1815                 if (!ti->discards_supported &&
1816                     (!ti->type->iterate_devices ||
1817                      ti->type->iterate_devices(ti, device_not_discard_capable, NULL)))
1818                         return false;
1819         }
1820
1821         return true;
1822 }
1823
1824 static int device_not_secure_erase_capable(struct dm_target *ti,
1825                                            struct dm_dev *dev, sector_t start,
1826                                            sector_t len, void *data)
1827 {
1828         struct request_queue *q = bdev_get_queue(dev->bdev);
1829
1830         return q && !blk_queue_secure_erase(q);
1831 }
1832
1833 static bool dm_table_supports_secure_erase(struct dm_table *t)
1834 {
1835         struct dm_target *ti;
1836         unsigned int i;
1837
1838         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1839                 ti = dm_table_get_target(t, i);
1840
1841                 if (!ti->num_secure_erase_bios)
1842                         return false;
1843
1844                 if (!ti->type->iterate_devices ||
1845                     ti->type->iterate_devices(ti, device_not_secure_erase_capable, NULL))
1846                         return false;
1847         }
1848
1849         return true;
1850 }
1851
1852 static int device_requires_stable_pages(struct dm_target *ti,
1853                                         struct dm_dev *dev, sector_t start,
1854                                         sector_t len, void *data)
1855 {
1856         struct request_queue *q = bdev_get_queue(dev->bdev);
1857
1858         return q && bdi_cap_stable_pages_required(q->backing_dev_info);
1859 }
1860
1861 /*
1862  * If any underlying device requires stable pages, a table must require
1863  * them as well.  Only targets that support iterate_devices are considered:
1864  * don't want error, zero, etc to require stable pages.
1865  */
1866 static bool dm_table_requires_stable_pages(struct dm_table *t)
1867 {
1868         struct dm_target *ti;
1869         unsigned i;
1870
1871         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1872                 ti = dm_table_get_target(t, i);
1873
1874                 if (ti->type->iterate_devices &&
1875                     ti->type->iterate_devices(ti, device_requires_stable_pages, NULL))
1876                         return true;
1877         }
1878
1879         return false;
1880 }
1881
1882 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1883                                struct queue_limits *limits)
1884 {
1885         bool wc = false, fua = false;
1886
1887         /*
1888          * Copy table's limits to the DM device's request_queue
1889          */
1890         q->limits = *limits;
1891
1892         if (!dm_table_supports_discards(t)) {
1893                 blk_queue_flag_clear(QUEUE_FLAG_DISCARD, q);
1894                 /* Must also clear discard limits... */
1895                 q->limits.max_discard_sectors = 0;
1896                 q->limits.max_hw_discard_sectors = 0;
1897                 q->limits.discard_granularity = 0;
1898                 q->limits.discard_alignment = 0;
1899                 q->limits.discard_misaligned = 0;
1900         } else
1901                 blk_queue_flag_set(QUEUE_FLAG_DISCARD, q);
1902
1903         if (dm_table_supports_secure_erase(t))
1904                 blk_queue_flag_set(QUEUE_FLAG_SECERASE, q);
1905
1906         if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_WC))) {
1907                 wc = true;
1908                 if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_FUA)))
1909                         fua = true;
1910         }
1911         blk_queue_write_cache(q, wc, fua);
1912
1913         if (dm_table_supports_dax(t, PAGE_SIZE))
1914                 blk_queue_flag_set(QUEUE_FLAG_DAX, q);
1915         else
1916                 blk_queue_flag_clear(QUEUE_FLAG_DAX, q);
1917
1918         if (dm_table_supports_dax_write_cache(t))
1919                 dax_write_cache(t->md->dax_dev, true);
1920
1921         /* Ensure that all underlying devices are non-rotational. */
1922         if (dm_table_all_devices_attribute(t, device_is_nonrot))
1923                 blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
1924         else
1925                 blk_queue_flag_clear(QUEUE_FLAG_NONROT, q);
1926
1927         if (!dm_table_supports_write_same(t))
1928                 q->limits.max_write_same_sectors = 0;
1929         if (!dm_table_supports_write_zeroes(t))
1930                 q->limits.max_write_zeroes_sectors = 0;
1931
1932         dm_table_verify_integrity(t);
1933
1934         /*
1935          * Some devices don't use blk_integrity but still want stable pages
1936          * because they do their own checksumming.
1937          */
1938         if (dm_table_requires_stable_pages(t))
1939                 q->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES;
1940         else
1941                 q->backing_dev_info->capabilities &= ~BDI_CAP_STABLE_WRITES;
1942
1943         /*
1944          * Determine whether or not this queue's I/O timings contribute
1945          * to the entropy pool, Only request-based targets use this.
1946          * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
1947          * have it set.
1948          */
1949         if (blk_queue_add_random(q) && dm_table_all_devices_attribute(t, device_is_not_random))
1950                 blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, q);
1951
1952         /*
1953          * For a zoned target, the number of zones should be updated for the
1954          * correct value to be exposed in sysfs queue/nr_zones. For a BIO based
1955          * target, this is all that is needed. For a request based target, the
1956          * queue zone bitmaps must also be updated.
1957          * Use blk_revalidate_disk_zones() to handle this.
1958          */
1959         if (blk_queue_is_zoned(q))
1960                 blk_revalidate_disk_zones(t->md->disk);
1961
1962         /* Allow reads to exceed readahead limits */
1963         q->backing_dev_info->io_pages = limits->max_sectors >> (PAGE_SHIFT - 9);
1964 }
1965
1966 unsigned int dm_table_get_num_targets(struct dm_table *t)
1967 {
1968         return t->num_targets;
1969 }
1970
1971 struct list_head *dm_table_get_devices(struct dm_table *t)
1972 {
1973         return &t->devices;
1974 }
1975
1976 fmode_t dm_table_get_mode(struct dm_table *t)
1977 {
1978         return t->mode;
1979 }
1980 EXPORT_SYMBOL(dm_table_get_mode);
1981
1982 enum suspend_mode {
1983         PRESUSPEND,
1984         PRESUSPEND_UNDO,
1985         POSTSUSPEND,
1986 };
1987
1988 static void suspend_targets(struct dm_table *t, enum suspend_mode mode)
1989 {
1990         int i = t->num_targets;
1991         struct dm_target *ti = t->targets;
1992
1993         lockdep_assert_held(&t->md->suspend_lock);
1994
1995         while (i--) {
1996                 switch (mode) {
1997                 case PRESUSPEND:
1998                         if (ti->type->presuspend)
1999                                 ti->type->presuspend(ti);
2000                         break;
2001                 case PRESUSPEND_UNDO:
2002                         if (ti->type->presuspend_undo)
2003                                 ti->type->presuspend_undo(ti);
2004                         break;
2005                 case POSTSUSPEND:
2006                         if (ti->type->postsuspend)
2007                                 ti->type->postsuspend(ti);
2008                         break;
2009                 }
2010                 ti++;
2011         }
2012 }
2013
2014 void dm_table_presuspend_targets(struct dm_table *t)
2015 {
2016         if (!t)
2017                 return;
2018
2019         suspend_targets(t, PRESUSPEND);
2020 }
2021
2022 void dm_table_presuspend_undo_targets(struct dm_table *t)
2023 {
2024         if (!t)
2025                 return;
2026
2027         suspend_targets(t, PRESUSPEND_UNDO);
2028 }
2029
2030 void dm_table_postsuspend_targets(struct dm_table *t)
2031 {
2032         if (!t)
2033                 return;
2034
2035         suspend_targets(t, POSTSUSPEND);
2036 }
2037
2038 int dm_table_resume_targets(struct dm_table *t)
2039 {
2040         int i, r = 0;
2041
2042         lockdep_assert_held(&t->md->suspend_lock);
2043
2044         for (i = 0; i < t->num_targets; i++) {
2045                 struct dm_target *ti = t->targets + i;
2046
2047                 if (!ti->type->preresume)
2048                         continue;
2049
2050                 r = ti->type->preresume(ti);
2051                 if (r) {
2052                         DMERR("%s: %s: preresume failed, error = %d",
2053                               dm_device_name(t->md), ti->type->name, r);
2054                         return r;
2055                 }
2056         }
2057
2058         for (i = 0; i < t->num_targets; i++) {
2059                 struct dm_target *ti = t->targets + i;
2060
2061                 if (ti->type->resume)
2062                         ti->type->resume(ti);
2063         }
2064
2065         return 0;
2066 }
2067
2068 void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb)
2069 {
2070         list_add(&cb->list, &t->target_callbacks);
2071 }
2072 EXPORT_SYMBOL_GPL(dm_table_add_target_callbacks);
2073
2074 int dm_table_any_congested(struct dm_table *t, int bdi_bits)
2075 {
2076         struct dm_dev_internal *dd;
2077         struct list_head *devices = dm_table_get_devices(t);
2078         struct dm_target_callbacks *cb;
2079         int r = 0;
2080
2081         list_for_each_entry(dd, devices, list) {
2082                 struct request_queue *q = bdev_get_queue(dd->dm_dev->bdev);
2083                 char b[BDEVNAME_SIZE];
2084
2085                 if (likely(q))
2086                         r |= bdi_congested(q->backing_dev_info, bdi_bits);
2087                 else
2088                         DMWARN_LIMIT("%s: any_congested: nonexistent device %s",
2089                                      dm_device_name(t->md),
2090                                      bdevname(dd->dm_dev->bdev, b));
2091         }
2092
2093         list_for_each_entry(cb, &t->target_callbacks, list)
2094                 if (cb->congested_fn)
2095                         r |= cb->congested_fn(cb, bdi_bits);
2096
2097         return r;
2098 }
2099
2100 struct mapped_device *dm_table_get_md(struct dm_table *t)
2101 {
2102         return t->md;
2103 }
2104 EXPORT_SYMBOL(dm_table_get_md);
2105
2106 const char *dm_table_device_name(struct dm_table *t)
2107 {
2108         return dm_device_name(t->md);
2109 }
2110 EXPORT_SYMBOL_GPL(dm_table_device_name);
2111
2112 void dm_table_run_md_queue_async(struct dm_table *t)
2113 {
2114         struct mapped_device *md;
2115         struct request_queue *queue;
2116
2117         if (!dm_table_request_based(t))
2118                 return;
2119
2120         md = dm_table_get_md(t);
2121         queue = dm_get_md_queue(md);
2122         if (queue)
2123                 blk_mq_run_hw_queues(queue, true);
2124 }
2125 EXPORT_SYMBOL(dm_table_run_md_queue_async);
2126