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