drivers/md/dm-table.c

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