drivers/md/dm-table.c

   1 /*
   2  * Copyright (C) 2001 Sistina Software (UK) Limited.
   3  * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
   4  *
   5  * This file is released under the GPL.
   6  */
   7
   8 #include "dm-core.h"
   9
  10 #include <linux/module.h>
  11 #include <linux/vmalloc.h>
  12 #include <linux/blkdev.h>
  13 #include <linux/namei.h>
  14 #include <linux/ctype.h>
  15 #include <linux/string.h>
  16 #include <linux/slab.h>
  17 #include <linux/interrupt.h>
  18 #include <linux/mutex.h>
  19 #include <linux/delay.h>
  20 #include <linux/atomic.h>
  21 #include <linux/blk-mq.h>
  22 #include <linux/mount.h>
  23 #include <linux/dax.h>
  24
  25 #define DM_MSG_PREFIX "table"
  26
  27 #define MAX_DEPTH 16
  28 #define NODE_SIZE L1_CACHE_BYTES
  29 #define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t))
  30 #define CHILDREN_PER_NODE (KEYS_PER_NODE + 1)
  31
  32 struct dm_table {
  33         struct mapped_device *md;
  34         enum dm_queue_mode type;
  35
  36         /* btree table */
  37         unsigned int depth;
  38         unsigned int counts[MAX_DEPTH]; /* in nodes */
  39         sector_t *index[MAX_DEPTH];
  40
  41         unsigned int num_targets;
  42         unsigned int num_allocated;
  43         sector_t *highs;
  44         struct dm_target *targets;
  45
  46         struct target_type *immutable_target_type;
  47
  48         bool integrity_supported:1;
  49         bool singleton:1;
  50         unsigned integrity_added:1;
  51
  52         /*
  53          * Indicates the rw permissions for the new logical
  54          * device.  This should be a combination of FMODE_READ
  55          * and FMODE_WRITE.
  56          */
  57         fmode_t mode;
  58
  59         /* a list of devices used by this table */
  60         struct list_head devices;
  61
  62         /* events get handed up using this callback */
  63         void (*event_fn)(void *);
  64         void *event_context;
  65
  66         struct dm_md_mempools *mempools;
  67
  68         struct list_head target_callbacks;
  69 };
  70
  71 /*
  72  * Similar to ceiling(log_size(n))
  73  */
  74 static unsigned int int_log(unsigned int n, unsigned int base)
  75 {
  76         int result = 0;
  77
  78         while (n > 1) {
  79                 n = dm_div_up(n, base);
  80                 result++;
  81         }
  82
  83         return result;
  84 }
  85
  86 /*
  87  * Calculate the index of the child node of the n'th node k'th key.
  88  */
  89 static inline unsigned int get_child(unsigned int n, unsigned int k)
  90 {
  91         return (n * CHILDREN_PER_NODE) + k;
  92 }
  93
  94 /*
  95  * Return the n'th node of level l from table t.
  96  */
  97 static inline sector_t *get_node(struct dm_table *t,
  98                                  unsigned int l, unsigned int n)
  99 {
 100         return t->index[l] + (n * KEYS_PER_NODE);
 101 }
 102
 103 /*
 104  * Return the highest key that you could lookup from the n'th
 105  * node on level l of the btree.
 106  */
 107 static sector_t high(struct dm_table *t, unsigned int l, unsigned int n)
 108 {
 109         for (; l < t->depth - 1; l++)
 110                 n = get_child(n, CHILDREN_PER_NODE - 1);
 111
 112         if (n >= t->counts[l])
 113                 return (sector_t) - 1;
 114
 115         return get_node(t, l, n)[KEYS_PER_NODE - 1];
 116 }
 117
 118 /*
 119  * Fills in a level of the btree based on the highs of the level
 120  * below it.
 121  */
 122 static int setup_btree_index(unsigned int l, struct dm_table *t)
 123 {
 124         unsigned int n, k;
 125         sector_t *node;
 126
 127         for (n = 0U; n < t->counts[l]; n++) {
 128                 node = get_node(t, l, n);
 129
 130                 for (k = 0U; k < KEYS_PER_NODE; k++)
 131                         node[k] = high(t, l + 1, get_child(n, k));
 132         }
 133
 134         return 0;
 135 }
 136
 137 void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size)
 138 {
 139         unsigned long size;
 140         void *addr;
 141
 142         /*
 143          * Check that we're not going to overflow.
 144          */
 145         if (nmemb > (ULONG_MAX / elem_size))
 146                 return NULL;
 147
 148         size = nmemb * elem_size;
 149         addr = vzalloc(size);
 150
 151         return addr;
 152 }
 153 EXPORT_SYMBOL(dm_vcalloc);
 154
 155 /*
 156  * highs, and targets are managed as dynamic arrays during a
 157  * table load.
 158  */
 159 static int alloc_targets(struct dm_table *t, unsigned int num)
 160 {
 161         sector_t *n_highs;
 162         struct dm_target *n_targets;
 163
 164         /*
 165          * Allocate both the target array and offset array at once.
 166          * Append an empty entry to catch sectors beyond the end of
 167          * the device.
 168          */
 169         n_highs = (sector_t *) dm_vcalloc(num + 1, sizeof(struct dm_target) +
 170                                           sizeof(sector_t));
 171         if (!n_highs)
 172                 return -ENOMEM;
 173
 174         n_targets = (struct dm_target *) (n_highs + num);
 175
 176         memset(n_highs, -1, sizeof(*n_highs) * num);
 177         vfree(t->highs);
 178
 179         t->num_allocated = num;
 180         t->highs = n_highs;
 181         t->targets = n_targets;
 182
 183         return 0;
 184 }
 185
 186 int dm_table_create(struct dm_table **result, fmode_t mode,
 187                     unsigned num_targets, struct mapped_device *md)
 188 {
 189         struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
 190
 191         if (!t)
 192                 return -ENOMEM;
 193
 194         INIT_LIST_HEAD(&t->devices);
 195         INIT_LIST_HEAD(&t->target_callbacks);
 196
 197         if (!num_targets)
 198                 num_targets = KEYS_PER_NODE;
 199
 200         num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
 201
 202         if (!num_targets) {
 203                 kfree(t);
 204                 return -ENOMEM;
 205         }
 206
 207         if (alloc_targets(t, num_targets)) {
 208                 kfree(t);
 209                 return -ENOMEM;
 210         }
 211
 212         t->type = DM_TYPE_NONE;
 213         t->mode = mode;
 214         t->md = md;
 215         *result = t;
 216         return 0;
 217 }
 218
 219 static void free_devices(struct list_head *devices, struct mapped_device *md)
 220 {
 221         struct list_head *tmp, *next;
 222
 223         list_for_each_safe(tmp, next, devices) {
 224                 struct dm_dev_internal *dd =
 225                     list_entry(tmp, struct dm_dev_internal, list);
 226                 DMWARN("%s: dm_table_destroy: dm_put_device call missing for %s",
 227                        dm_device_name(md), dd->dm_dev->name);
 228                 dm_put_table_device(md, dd->dm_dev);
 229                 kfree(dd);
 230         }
 231 }
 232
 233 void dm_table_destroy(struct dm_table *t)
 234 {
 235         unsigned int i;
 236
 237         if (!t)
 238                 return;
 239
 240         /* free the indexes */
 241         if (t->depth >= 2)
 242                 vfree(t->index[t->depth - 2]);
 243
 244         /* free the targets */
 245         for (i = 0; i < t->num_targets; i++) {
 246                 struct dm_target *tgt = t->targets + i;
 247
 248                 if (tgt->type->dtr)
 249                         tgt->type->dtr(tgt);
 250
 251                 dm_put_target_type(tgt->type);
 252         }
 253
 254         vfree(t->highs);
 255
 256         /* free the device list */
 257         free_devices(&t->devices, t->md);
 258
 259         dm_free_md_mempools(t->mempools);
 260
 261         kfree(t);
 262 }
 263
 264 /*
 265  * See if we've already got a device in the list.
 266  */
 267 static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
 268 {
 269         struct dm_dev_internal *dd;
 270
 271         list_for_each_entry (dd, l, list)
 272                 if (dd->dm_dev->bdev->bd_dev == dev)
 273                         return dd;
 274
 275         return NULL;
 276 }
 277
 278 /*
 279  * If possible, this checks an area of a destination device is invalid.
 280  */
 281 static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
 282                                   sector_t start, sector_t len, void *data)
 283 {
 284         struct request_queue *q;
 285         struct queue_limits *limits = data;
 286         struct block_device *bdev = dev->bdev;
 287         sector_t dev_size =
 288                 i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
 289         unsigned short logical_block_size_sectors =
 290                 limits->logical_block_size >> SECTOR_SHIFT;
 291         char b[BDEVNAME_SIZE];
 292
 293         /*
 294          * Some devices exist without request functions,
 295          * such as loop devices not yet bound to backing files.
 296          * Forbid the use of such devices.
 297          */
 298         q = bdev_get_queue(bdev);
 299         if (!q || !q->make_request_fn) {
 300                 DMWARN("%s: %s is not yet initialised: "
 301                        "start=%llu, len=%llu, dev_size=%llu",
 302                        dm_device_name(ti->table->md), bdevname(bdev, b),
 303                        (unsigned long long)start,
 304                        (unsigned long long)len,
 305                        (unsigned long long)dev_size);
 306                 return 1;
 307         }
 308
 309         if (!dev_size)
 310                 return 0;
 311
 312         if ((start >= dev_size) || (start + len > dev_size)) {
 313                 DMWARN("%s: %s too small for target: "
 314                        "start=%llu, len=%llu, dev_size=%llu",
 315                        dm_device_name(ti->table->md), bdevname(bdev, b),
 316                        (unsigned long long)start,
 317                        (unsigned long long)len,
 318                        (unsigned long long)dev_size);
 319                 return 1;
 320         }
 321
 322         /*
 323          * If the target is mapped to zoned block device(s), check
 324          * that the zones are not partially mapped.
 325          */
 326         if (bdev_zoned_model(bdev) != BLK_ZONED_NONE) {
 327                 unsigned int zone_sectors = bdev_zone_sectors(bdev);
 328
 329                 if (start & (zone_sectors - 1)) {
 330                         DMWARN("%s: start=%llu not aligned to h/w zone size %u of %s",
 331                                dm_device_name(ti->table->md),
 332                                (unsigned long long)start,
 333                                zone_sectors, bdevname(bdev, b));
 334                         return 1;
 335                 }
 336
 337                 /*
 338                  * Note: The last zone of a zoned block device may be smaller
 339                  * than other zones. So for a target mapping the end of a
 340                  * zoned block device with such a zone, len would not be zone
 341                  * aligned. We do not allow such last smaller zone to be part
 342                  * of the mapping here to ensure that mappings with multiple
 343                  * devices do not end up with a smaller zone in the middle of
 344                  * the sector range.
 345                  */
 346                 if (len & (zone_sectors - 1)) {
 347                         DMWARN("%s: len=%llu not aligned to h/w zone size %u of %s",
 348                                dm_device_name(ti->table->md),
 349                                (unsigned long long)len,
 350                                zone_sectors, bdevname(bdev, b));
 351                         return 1;
 352                 }
 353         }
 354
 355         if (logical_block_size_sectors <= 1)
 356                 return 0;
 357
 358         if (start & (logical_block_size_sectors - 1)) {
 359                 DMWARN("%s: start=%llu not aligned to h/w "
 360                        "logical block size %u of %s",
 361                        dm_device_name(ti->table->md),
 362                        (unsigned long long)start,
 363                        limits->logical_block_size, bdevname(bdev, b));
 364                 return 1;
 365         }
 366
 367         if (len & (logical_block_size_sectors - 1)) {
 368                 DMWARN("%s: len=%llu not aligned to h/w "
 369                        "logical block size %u of %s",
 370                        dm_device_name(ti->table->md),
 371                        (unsigned long long)len,
 372                        limits->logical_block_size, bdevname(bdev, b));
 373                 return 1;
 374         }
 375
 376         return 0;
 377 }
 378
 379 /*
 380  * This upgrades the mode on an already open dm_dev, being
 381  * careful to leave things as they were if we fail to reopen the
 382  * device and not to touch the existing bdev field in case
 383  * it is accessed concurrently inside dm_table_any_congested().
 384  */
 385 static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
 386                         struct mapped_device *md)
 387 {
 388         int r;
 389         struct dm_dev *old_dev, *new_dev;
 390
 391         old_dev = dd->dm_dev;
 392
 393         r = dm_get_table_device(md, dd->dm_dev->bdev->bd_dev,
 394                                 dd->dm_dev->mode | new_mode, &new_dev);
 395         if (r)
 396                 return r;
 397
 398         dd->dm_dev = new_dev;
 399         dm_put_table_device(md, old_dev);
 400
 401         return 0;
 402 }
 403
 404 /*
 405  * Convert the path to a device
 406  */
 407 dev_t dm_get_dev_t(const char *path)
 408 {
 409         dev_t dev;
 410         struct block_device *bdev;
 411
 412         bdev = lookup_bdev(path);
 413         if (IS_ERR(bdev))
 414                 dev = name_to_dev_t(path);
 415         else {
 416                 dev = bdev->bd_dev;
 417                 bdput(bdev);
 418         }
 419
 420         return dev;
 421 }
 422 EXPORT_SYMBOL_GPL(dm_get_dev_t);
 423
 424 /*
 425  * Add a device to the list, or just increment the usage count if
 426  * it's already present.
 427  */
 428 int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
 429                   struct dm_dev **result)
 430 {
 431         int r;
 432         dev_t dev;
 433         struct dm_dev_internal *dd;
 434         struct dm_table *t = ti->table;
 435
 436         BUG_ON(!t);
 437
 438         dev = dm_get_dev_t(path);
 439         if (!dev)
 440                 return -ENODEV;
 441
 442         dd = find_device(&t->devices, dev);
 443         if (!dd) {
 444                 dd = kmalloc(sizeof(*dd), GFP_KERNEL);
 445                 if (!dd)
 446                         return -ENOMEM;
 447
 448                 if ((r = dm_get_table_device(t->md, dev, mode, &dd->dm_dev))) {
 449                         kfree(dd);
 450                         return r;
 451                 }
 452
 453                 refcount_set(&dd->count, 1);
 454                 list_add(&dd->list, &t->devices);
 455                 goto out;
 456
 457         } else if (dd->dm_dev->mode != (mode | dd->dm_dev->mode)) {
 458                 r = upgrade_mode(dd, mode, t->md);
 459                 if (r)
 460                         return r;
 461         }
 462         refcount_inc(&dd->count);
 463 out:
 464         *result = dd->dm_dev;
 465         return 0;
 466 }
 467 EXPORT_SYMBOL(dm_get_device);
 468
 469 static int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
 470                                 sector_t start, sector_t len, void *data)
 471 {
 472         struct queue_limits *limits = data;
 473         struct block_device *bdev = dev->bdev;
 474         struct request_queue *q = bdev_get_queue(bdev);
 475         char b[BDEVNAME_SIZE];
 476
 477         if (unlikely(!q)) {
 478                 DMWARN("%s: Cannot set limits for nonexistent device %s",
 479                        dm_device_name(ti->table->md), bdevname(bdev, b));
 480                 return 0;
 481         }
 482
 483         if (bdev_stack_limits(limits, bdev, start) < 0)
 484                 DMWARN("%s: adding target device %s caused an alignment inconsistency: "
 485                        "physical_block_size=%u, logical_block_size=%u, "
 486                        "alignment_offset=%u, start=%llu",
 487                        dm_device_name(ti->table->md), bdevname(bdev, b),
 488                        q->limits.physical_block_size,
 489                        q->limits.logical_block_size,
 490                        q->limits.alignment_offset,
 491                        (unsigned long long) start << SECTOR_SHIFT);
 492
 493         limits->zoned = blk_queue_zoned_model(q);
 494
 495         return 0;
 496 }
 497
 498 /*
 499  * Decrement a device's use count and remove it if necessary.
 500  */
 501 void dm_put_device(struct dm_target *ti, struct dm_dev *d)
 502 {
 503         int found = 0;
 504         struct list_head *devices = &ti->table->devices;
 505         struct dm_dev_internal *dd;
 506
 507         list_for_each_entry(dd, devices, list) {
 508                 if (dd->dm_dev == d) {
 509                         found = 1;
 510                         break;
 511                 }
 512         }
 513         if (!found) {
 514                 DMWARN("%s: device %s not in table devices list",
 515                        dm_device_name(ti->table->md), d->name);
 516                 return;
 517         }
 518         if (refcount_dec_and_test(&dd->count)) {
 519                 dm_put_table_device(ti->table->md, d);
 520                 list_del(&dd->list);
 521                 kfree(dd);
 522         }
 523 }
 524 EXPORT_SYMBOL(dm_put_device);
 525
 526 /*
 527  * Checks to see if the target joins onto the end of the table.
 528  */
 529 static int adjoin(struct dm_table *table, struct dm_target *ti)
 530 {
 531         struct dm_target *prev;
 532
 533         if (!table->num_targets)
 534                 return !ti->begin;
 535
 536         prev = &table->targets[table->num_targets - 1];
 537         return (ti->begin == (prev->begin + prev->len));
 538 }
 539
 540 /*
 541  * Used to dynamically allocate the arg array.
 542  *
 543  * We do first allocation with GFP_NOIO because dm-mpath and dm-thin must
 544  * process messages even if some device is suspended. These messages have a
 545  * small fixed number of arguments.
 546  *
 547  * On the other hand, dm-switch needs to process bulk data using messages and
 548  * excessive use of GFP_NOIO could cause trouble.
 549  */
 550 static char **realloc_argv(unsigned *size, char **old_argv)
 551 {
 552         char **argv;
 553         unsigned new_size;
 554         gfp_t gfp;
 555
 556         if (*size) {
 557                 new_size = *size * 2;
 558                 gfp = GFP_KERNEL;
 559         } else {
 560                 new_size = 8;
 561                 gfp = GFP_NOIO;
 562         }
 563         argv = kmalloc_array(new_size, sizeof(*argv), gfp);
 564         if (argv && old_argv) {
 565                 memcpy(argv, old_argv, *size * sizeof(*argv));
 566                 *size = new_size;
 567         }
 568
 569         kfree(old_argv);
 570         return argv;
 571 }
 572
 573 /*
 574  * Destructively splits up the argument list to pass to ctr.
 575  */
 576 int dm_split_args(int *argc, char ***argvp, char *input)
 577 {
 578         char *start, *end = input, *out, **argv = NULL;
 579         unsigned array_size = 0;
 580
 581         *argc = 0;
 582
 583         if (!input) {
 584                 *argvp = NULL;
 585                 return 0;
 586         }
 587
 588         argv = realloc_argv(&array_size, argv);
 589         if (!argv)
 590                 return -ENOMEM;
 591
 592         while (1) {
 593                 /* Skip whitespace */
 594                 start = skip_spaces(end);
 595
 596                 if (!*start)
 597                         break;  /* success, we hit the end */
 598
 599                 /* 'out' is used to remove any back-quotes */
 600                 end = out = start;
 601                 while (*end) {
 602                         /* Everything apart from '\0' can be quoted */
 603                         if (*end == '\\' && *(end + 1)) {
 604                                 *out++ = *(end + 1);
 605                                 end += 2;
 606                                 continue;
 607                         }
 608
 609                         if (isspace(*end))
 610                                 break;  /* end of token */
 611
 612                         *out++ = *end++;
 613                 }
 614
 615                 /* have we already filled the array ? */
 616                 if ((*argc + 1) > array_size) {
 617                         argv = realloc_argv(&array_size, argv);
 618                         if (!argv)
 619                                 return -ENOMEM;
 620                 }
 621
 622                 /* we know this is whitespace */
 623                 if (*end)
 624                         end++;
 625
 626                 /* terminate the string and put it in the array */
 627                 *out = '\0';
 628                 argv[*argc] = start;
 629                 (*argc)++;
 630         }
 631
 632         *argvp = argv;
 633         return 0;
 634 }
 635
 636 /*
 637  * Impose necessary and sufficient conditions on a devices's table such
 638  * that any incoming bio which respects its logical_block_size can be
 639  * processed successfully.  If it falls across the boundary between
 640  * two or more targets, the size of each piece it gets split into must
 641  * be compatible with the logical_block_size of the target processing it.
 642  */
 643 static int validate_hardware_logical_block_alignment(struct dm_table *table,
 644                                                  struct queue_limits *limits)
 645 {
 646         /*
 647          * This function uses arithmetic modulo the logical_block_size
 648          * (in units of 512-byte sectors).
 649          */
 650         unsigned short device_logical_block_size_sects =
 651                 limits->logical_block_size >> SECTOR_SHIFT;
 652
 653         /*
 654          * Offset of the start of the next table entry, mod logical_block_size.
 655          */
 656         unsigned short next_target_start = 0;
 657
 658         /*
 659          * Given an aligned bio that extends beyond the end of a
 660          * target, how many sectors must the next target handle?
 661          */
 662         unsigned short remaining = 0;
 663
 664         struct dm_target *uninitialized_var(ti);
 665         struct queue_limits ti_limits;
 666         unsigned i;
 667
 668         /*
 669          * Check each entry in the table in turn.
 670          */
 671         for (i = 0; i < dm_table_get_num_targets(table); i++) {
 672                 ti = dm_table_get_target(table, i);
 673
 674                 blk_set_stacking_limits(&ti_limits);
 675
 676                 /* combine all target devices' limits */
 677                 if (ti->type->iterate_devices)
 678                         ti->type->iterate_devices(ti, dm_set_device_limits,
 679                                                   &ti_limits);
 680
 681                 /*
 682                  * If the remaining sectors fall entirely within this
 683                  * table entry are they compatible with its logical_block_size?
 684                  */
 685                 if (remaining < ti->len &&
 686                     remaining & ((ti_limits.logical_block_size >>
 687                                   SECTOR_SHIFT) - 1))
 688                         break;  /* Error */
 689
 690                 next_target_start =
 691                     (unsigned short) ((next_target_start + ti->len) &
 692                                       (device_logical_block_size_sects - 1));
 693                 remaining = next_target_start ?
 694                     device_logical_block_size_sects - next_target_start : 0;
 695         }
 696
 697         if (remaining) {
 698                 DMWARN("%s: table line %u (start sect %llu len %llu) "
 699                        "not aligned to h/w logical block size %u",
 700                        dm_device_name(table->md), i,
 701                        (unsigned long long) ti->begin,
 702                        (unsigned long long) ti->len,
 703                        limits->logical_block_size);
 704                 return -EINVAL;
 705         }
 706
 707         return 0;
 708 }
 709
 710 int dm_table_add_target(struct dm_table *t, const char *type,
 711                         sector_t start, sector_t len, char *params)
 712 {
 713         int r = -EINVAL, argc;
 714         char **argv;
 715         struct dm_target *tgt;
 716
 717         if (t->singleton) {
 718                 DMERR("%s: target type %s must appear alone in table",
 719                       dm_device_name(t->md), t->targets->type->name);
 720                 return -EINVAL;
 721         }
 722
 723         BUG_ON(t->num_targets >= t->num_allocated);
 724
 725         tgt = t->targets + t->num_targets;
 726         memset(tgt, 0, sizeof(*tgt));
 727
 728         if (!len) {
 729                 DMERR("%s: zero-length target", dm_device_name(t->md));
 730                 return -EINVAL;
 731         }
 732
 733         tgt->type = dm_get_target_type(type);
 734         if (!tgt->type) {
 735                 DMERR("%s: %s: unknown target type", dm_device_name(t->md), type);
 736                 return -EINVAL;
 737         }
 738
 739         if (dm_target_needs_singleton(tgt->type)) {
 740                 if (t->num_targets) {
 741                         tgt->error = "singleton target type must appear alone in table";
 742                         goto bad;
 743                 }
 744                 t->singleton = true;
 745         }
 746
 747         if (dm_target_always_writeable(tgt->type) && !(t->mode & FMODE_WRITE)) {
 748                 tgt->error = "target type may not be included in a read-only table";
 749                 goto bad;
 750         }
 751
 752         if (t->immutable_target_type) {
 753                 if (t->immutable_target_type != tgt->type) {
 754                         tgt->error = "immutable target type cannot be mixed with other target types";
 755                         goto bad;
 756                 }
 757         } else if (dm_target_is_immutable(tgt->type)) {
 758                 if (t->num_targets) {
 759                         tgt->error = "immutable target type cannot be mixed with other target types";
 760                         goto bad;
 761                 }
 762                 t->immutable_target_type = tgt->type;
 763         }
 764
 765         if (dm_target_has_integrity(tgt->type))
 766                 t->integrity_added = 1;
 767
 768         tgt->table = t;
 769         tgt->begin = start;
 770         tgt->len = len;
 771         tgt->error = "Unknown error";
 772
 773         /*
 774          * Does this target adjoin the previous one ?
 775          */
 776         if (!adjoin(t, tgt)) {
 777                 tgt->error = "Gap in table";
 778                 goto bad;
 779         }
 780
 781         r = dm_split_args(&argc, &argv, params);
 782         if (r) {
 783                 tgt->error = "couldn't split parameters (insufficient memory)";
 784                 goto bad;
 785         }
 786
 787         r = tgt->type->ctr(tgt, argc, argv);
 788         kfree(argv);
 789         if (r)
 790                 goto bad;
 791
 792         t->highs[t->num_targets++] = tgt->begin + tgt->len - 1;
 793
 794         if (!tgt->num_discard_bios && tgt->discards_supported)
 795                 DMWARN("%s: %s: ignoring discards_supported because num_discard_bios is zero.",
 796                        dm_device_name(t->md), type);
 797
 798         return 0;
 799
 800  bad:
 801         DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error);
 802         dm_put_target_type(tgt->type);
 803         return r;
 804 }
 805
 806 /*
 807  * Target argument parsing helpers.
 808  */
 809 static int validate_next_arg(const struct dm_arg *arg,
 810                              struct dm_arg_set *arg_set,
 811                              unsigned *value, char **error, unsigned grouped)
 812 {
 813         const char *arg_str = dm_shift_arg(arg_set);
 814         char dummy;
 815
 816         if (!arg_str ||
 817             (sscanf(arg_str, "%u%c", value, &dummy) != 1) ||
 818             (*value < arg->min) ||
 819             (*value > arg->max) ||
 820             (grouped && arg_set->argc < *value)) {
 821                 *error = arg->error;
 822                 return -EINVAL;
 823         }
 824
 825         return 0;
 826 }
 827
 828 int dm_read_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
 829                 unsigned *value, char **error)
 830 {
 831         return validate_next_arg(arg, arg_set, value, error, 0);
 832 }
 833 EXPORT_SYMBOL(dm_read_arg);
 834
 835 int dm_read_arg_group(const struct dm_arg *arg, struct dm_arg_set *arg_set,
 836                       unsigned *value, char **error)
 837 {
 838         return validate_next_arg(arg, arg_set, value, error, 1);
 839 }
 840 EXPORT_SYMBOL(dm_read_arg_group);
 841
 842 const char *dm_shift_arg(struct dm_arg_set *as)
 843 {
 844         char *r;
 845
 846         if (as->argc) {
 847                 as->argc--;
 848                 r = *as->argv;
 849                 as->argv++;
 850                 return r;
 851         }
 852
 853         return NULL;
 854 }
 855 EXPORT_SYMBOL(dm_shift_arg);
 856
 857 void dm_consume_args(struct dm_arg_set *as, unsigned num_args)
 858 {
 859         BUG_ON(as->argc < num_args);
 860         as->argc -= num_args;
 861         as->argv += num_args;
 862 }
 863 EXPORT_SYMBOL(dm_consume_args);
 864
 865 static bool __table_type_bio_based(enum dm_queue_mode table_type)
 866 {
 867         return (table_type == DM_TYPE_BIO_BASED ||
 868                 table_type == DM_TYPE_DAX_BIO_BASED ||
 869                 table_type == DM_TYPE_NVME_BIO_BASED);
 870 }
 871
 872 static bool __table_type_request_based(enum dm_queue_mode table_type)
 873 {
 874         return table_type == DM_TYPE_REQUEST_BASED;
 875 }
 876
 877 void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type)
 878 {
 879         t->type = type;
 880 }
 881 EXPORT_SYMBOL_GPL(dm_table_set_type);
 882
 883 /* validate the dax capability of the target device span */
 884 int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,
 885                         sector_t start, sector_t len, void *data)
 886 {
 887         int blocksize = *(int *) data;
 888
 889         return generic_fsdax_supported(dev->dax_dev, dev->bdev, blocksize,
 890                                        start, len);
 891 }
 892
 893 /* Check devices support synchronous DAX */
 894 static int device_dax_synchronous(struct dm_target *ti, struct dm_dev *dev,
 895                                   sector_t start, sector_t len, void *data)
 896 {
 897         return dev->dax_dev && dax_synchronous(dev->dax_dev);
 898 }
 899
 900 bool dm_table_supports_dax(struct dm_table *t,
 901                            iterate_devices_callout_fn iterate_fn, int *blocksize)
 902 {
 903         struct dm_target *ti;
 904         unsigned i;
 905
 906         /* Ensure that all targets support DAX. */
 907         for (i = 0; i < dm_table_get_num_targets(t); i++) {
 908                 ti = dm_table_get_target(t, i);
 909
 910                 if (!ti->type->direct_access)
 911                         return false;
 912
 913                 if (!ti->type->iterate_devices ||
 914                     !ti->type->iterate_devices(ti, iterate_fn, blocksize))
 915                         return false;
 916         }
 917
 918         return true;
 919 }
 920
 921 static bool dm_table_does_not_support_partial_completion(struct dm_table *t);
 922
 923 struct verify_rq_based_data {
 924         unsigned sq_count;
 925         unsigned mq_count;
 926 };
 927
 928 static int device_is_rq_based(struct dm_target *ti, struct dm_dev *dev,
 929                               sector_t start, sector_t len, void *data)
 930 {
 931         struct request_queue *q = bdev_get_queue(dev->bdev);
 932         struct verify_rq_based_data *v = data;
 933
 934         if (queue_is_mq(q))
 935                 v->mq_count++;
 936         else
 937                 v->sq_count++;
 938
 939         return queue_is_mq(q);
 940 }
 941
 942 static int dm_table_determine_type(struct dm_table *t)
 943 {
 944         unsigned i;
 945         unsigned bio_based = 0, request_based = 0, hybrid = 0;
 946         struct verify_rq_based_data v = {.sq_count = 0, .mq_count = 0};
 947         struct dm_target *tgt;
 948         struct list_head *devices = dm_table_get_devices(t);
 949         enum dm_queue_mode live_md_type = dm_get_md_type(t->md);
 950         int page_size = PAGE_SIZE;
 951
 952         if (t->type != DM_TYPE_NONE) {
 953                 /* target already set the table's type */
 954                 if (t->type == DM_TYPE_BIO_BASED) {
 955                         /* possibly upgrade to a variant of bio-based */
 956                         goto verify_bio_based;
 957                 }
 958                 BUG_ON(t->type == DM_TYPE_DAX_BIO_BASED);
 959                 BUG_ON(t->type == DM_TYPE_NVME_BIO_BASED);
 960                 goto verify_rq_based;
 961         }
 962
 963         for (i = 0; i < t->num_targets; i++) {
 964                 tgt = t->targets + i;
 965                 if (dm_target_hybrid(tgt))
 966                         hybrid = 1;
 967                 else if (dm_target_request_based(tgt))
 968                         request_based = 1;
 969                 else
 970                         bio_based = 1;
 971
 972                 if (bio_based && request_based) {
 973                         DMERR("Inconsistent table: different target types"
 974                               " can't be mixed up");
 975                         return -EINVAL;
 976                 }
 977         }
 978
 979         if (hybrid && !bio_based && !request_based) {
 980                 /*
 981                  * The targets can work either way.
 982                  * Determine the type from the live device.
 983                  * Default to bio-based if device is new.
 984                  */
 985                 if (__table_type_request_based(live_md_type))
 986                         request_based = 1;
 987                 else
 988                         bio_based = 1;
 989         }
 990
 991         if (bio_based) {
 992 verify_bio_based:
 993                 /* We must use this table as bio-based */
 994                 t->type = DM_TYPE_BIO_BASED;
 995                 if (dm_table_supports_dax(t, device_supports_dax, &page_size) ||
 996                     (list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED)) {
 997                         t->type = DM_TYPE_DAX_BIO_BASED;
 998                 } else {
 999                         /* Check if upgrading to NVMe bio-based is valid or required */
1000                         tgt = dm_table_get_immutable_target(t);
1001                         if (tgt && !tgt->max_io_len && dm_table_does_not_support_partial_completion(t)) {
1002                                 t->type = DM_TYPE_NVME_BIO_BASED;
1003                                 goto verify_rq_based; /* must be stacked directly on NVMe (blk-mq) */
1004                         } else if (list_empty(devices) && live_md_type == DM_TYPE_NVME_BIO_BASED) {
1005                                 t->type = DM_TYPE_NVME_BIO_BASED;
1006                         }
1007                 }
1008                 return 0;
1009         }
1010
1011         BUG_ON(!request_based); /* No targets in this table */
1012
1013         t->type = DM_TYPE_REQUEST_BASED;
1014
1015 verify_rq_based:
1016         /*
1017          * Request-based dm supports only tables that have a single target now.
1018          * To support multiple targets, request splitting support is needed,
1019          * and that needs lots of changes in the block-layer.
1020          * (e.g. request completion process for partial completion.)
1021          */
1022         if (t->num_targets > 1) {
1023                 DMERR("%s DM doesn't support multiple targets",
1024                       t->type == DM_TYPE_NVME_BIO_BASED ? "nvme bio-based" : "request-based");
1025                 return -EINVAL;
1026         }
1027
1028         if (list_empty(devices)) {
1029                 int srcu_idx;
1030                 struct dm_table *live_table = dm_get_live_table(t->md, &srcu_idx);
1031
1032                 /* inherit live table's type */
1033                 if (live_table)
1034                         t->type = live_table->type;
1035                 dm_put_live_table(t->md, srcu_idx);
1036                 return 0;
1037         }
1038
1039         tgt = dm_table_get_immutable_target(t);
1040         if (!tgt) {
1041                 DMERR("table load rejected: immutable target is required");
1042                 return -EINVAL;
1043         } else if (tgt->max_io_len) {
1044                 DMERR("table load rejected: immutable target that splits IO is not supported");
1045                 return -EINVAL;
1046         }
1047
1048         /* Non-request-stackable devices can't be used for request-based dm */
1049         if (!tgt->type->iterate_devices ||
1050             !tgt->type->iterate_devices(tgt, device_is_rq_based, &v)) {
1051                 DMERR("table load rejected: including non-request-stackable devices");
1052                 return -EINVAL;
1053         }
1054         if (v.sq_count > 0) {
1055                 DMERR("table load rejected: not all devices are blk-mq request-stackable");
1056                 return -EINVAL;
1057         }
1058
1059         return 0;
1060 }
1061
1062 enum dm_queue_mode dm_table_get_type(struct dm_table *t)
1063 {
1064         return t->type;
1065 }
1066
1067 struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
1068 {
1069         return t->immutable_target_type;
1070 }
1071
1072 struct dm_target *dm_table_get_immutable_target(struct dm_table *t)
1073 {
1074         /* Immutable target is implicitly a singleton */
1075         if (t->num_targets > 1 ||
1076             !dm_target_is_immutable(t->targets[0].type))
1077                 return NULL;
1078
1079         return t->targets;
1080 }
1081
1082 struct dm_target *dm_table_get_wildcard_target(struct dm_table *t)
1083 {
1084         struct dm_target *ti;
1085         unsigned i;
1086
1087         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1088                 ti = dm_table_get_target(t, i);
1089                 if (dm_target_is_wildcard(ti->type))
1090                         return ti;
1091         }
1092
1093         return NULL;
1094 }
1095
1096 bool dm_table_bio_based(struct dm_table *t)
1097 {
1098         return __table_type_bio_based(dm_table_get_type(t));
1099 }
1100
1101 bool dm_table_request_based(struct dm_table *t)
1102 {
1103         return __table_type_request_based(dm_table_get_type(t));
1104 }
1105
1106 static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device *md)
1107 {
1108         enum dm_queue_mode type = dm_table_get_type(t);
1109         unsigned per_io_data_size = 0;
1110         unsigned min_pool_size = 0;
1111         struct dm_target *ti;
1112         unsigned i;
1113
1114         if (unlikely(type == DM_TYPE_NONE)) {
1115                 DMWARN("no table type is set, can't allocate mempools");
1116                 return -EINVAL;
1117         }
1118
1119         if (__table_type_bio_based(type))
1120                 for (i = 0; i < t->num_targets; i++) {
1121                         ti = t->targets + i;
1122                         per_io_data_size = max(per_io_data_size, ti->per_io_data_size);
1123                         min_pool_size = max(min_pool_size, ti->num_flush_bios);
1124                 }
1125
1126         t->mempools = dm_alloc_md_mempools(md, type, t->integrity_supported,
1127                                            per_io_data_size, min_pool_size);
1128         if (!t->mempools)
1129                 return -ENOMEM;
1130
1131         return 0;
1132 }
1133
1134 void dm_table_free_md_mempools(struct dm_table *t)
1135 {
1136         dm_free_md_mempools(t->mempools);
1137         t->mempools = NULL;
1138 }
1139
1140 struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t)
1141 {
1142         return t->mempools;
1143 }
1144
1145 static int setup_indexes(struct dm_table *t)
1146 {
1147         int i;
1148         unsigned int total = 0;
1149         sector_t *indexes;
1150
1151         /* allocate the space for *all* the indexes */
1152         for (i = t->depth - 2; i >= 0; i--) {
1153                 t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
1154                 total += t->counts[i];
1155         }
1156
1157         indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE);
1158         if (!indexes)
1159                 return -ENOMEM;
1160
1161         /* set up internal nodes, bottom-up */
1162         for (i = t->depth - 2; i >= 0; i--) {
1163                 t->index[i] = indexes;
1164                 indexes += (KEYS_PER_NODE * t->counts[i]);
1165                 setup_btree_index(i, t);
1166         }
1167
1168         return 0;
1169 }
1170
1171 /*
1172  * Builds the btree to index the map.
1173  */
1174 static int dm_table_build_index(struct dm_table *t)
1175 {
1176         int r = 0;
1177         unsigned int leaf_nodes;
1178
1179         /* how many indexes will the btree have ? */
1180         leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
1181         t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
1182
1183         /* leaf layer has already been set up */
1184         t->counts[t->depth - 1] = leaf_nodes;
1185         t->index[t->depth - 1] = t->highs;
1186
1187         if (t->depth >= 2)
1188                 r = setup_indexes(t);
1189
1190         return r;
1191 }
1192
1193 static bool integrity_profile_exists(struct gendisk *disk)
1194 {
1195         return !!blk_get_integrity(disk);
1196 }
1197
1198 /*
1199  * Get a disk whose integrity profile reflects the table's profile.
1200  * Returns NULL if integrity support was inconsistent or unavailable.
1201  */
1202 static struct gendisk * dm_table_get_integrity_disk(struct dm_table *t)
1203 {
1204         struct list_head *devices = dm_table_get_devices(t);
1205         struct dm_dev_internal *dd = NULL;
1206         struct gendisk *prev_disk = NULL, *template_disk = NULL;
1207         unsigned i;
1208
1209         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1210                 struct dm_target *ti = dm_table_get_target(t, i);
1211                 if (!dm_target_passes_integrity(ti->type))
1212                         goto no_integrity;
1213         }
1214
1215         list_for_each_entry(dd, devices, list) {
1216                 template_disk = dd->dm_dev->bdev->bd_disk;
1217                 if (!integrity_profile_exists(template_disk))
1218                         goto no_integrity;
1219                 else if (prev_disk &&
1220                          blk_integrity_compare(prev_disk, template_disk) < 0)
1221                         goto no_integrity;
1222                 prev_disk = template_disk;
1223         }
1224
1225         return template_disk;
1226
1227 no_integrity:
1228         if (prev_disk)
1229                 DMWARN("%s: integrity not set: %s and %s profile mismatch",
1230                        dm_device_name(t->md),
1231                        prev_disk->disk_name,
1232                        template_disk->disk_name);
1233         return NULL;
1234 }
1235
1236 /*
1237  * Register the mapped device for blk_integrity support if the
1238  * underlying devices have an integrity profile.  But all devices may
1239  * not have matching profiles (checking all devices isn't reliable
1240  * during table load because this table may use other DM device(s) which
1241  * must be resumed before they will have an initialized integity
1242  * profile).  Consequently, stacked DM devices force a 2 stage integrity
1243  * profile validation: First pass during table load, final pass during
1244  * resume.
1245  */
1246 static int dm_table_register_integrity(struct dm_table *t)
1247 {
1248         struct mapped_device *md = t->md;
1249         struct gendisk *template_disk = NULL;
1250
1251         /* If target handles integrity itself do not register it here. */
1252         if (t->integrity_added)
1253                 return 0;
1254
1255         template_disk = dm_table_get_integrity_disk(t);
1256         if (!template_disk)
1257                 return 0;
1258
1259         if (!integrity_profile_exists(dm_disk(md))) {
1260                 t->integrity_supported = true;
1261                 /*
1262                  * Register integrity profile during table load; we can do
1263                  * this because the final profile must match during resume.
1264                  */
1265                 blk_integrity_register(dm_disk(md),
1266                                        blk_get_integrity(template_disk));
1267                 return 0;
1268         }
1269
1270         /*
1271          * If DM device already has an initialized integrity
1272          * profile the new profile should not conflict.
1273          */
1274         if (blk_integrity_compare(dm_disk(md), template_disk) < 0) {
1275                 DMWARN("%s: conflict with existing integrity profile: "
1276                        "%s profile mismatch",
1277                        dm_device_name(t->md),
1278                        template_disk->disk_name);
1279                 return 1;
1280         }
1281
1282         /* Preserve existing integrity profile */
1283         t->integrity_supported = true;
1284         return 0;
1285 }
1286
1287 /*
1288  * Prepares the table for use by building the indices,
1289  * setting the type, and allocating mempools.
1290  */
1291 int dm_table_complete(struct dm_table *t)
1292 {
1293         int r;
1294
1295         r = dm_table_determine_type(t);
1296         if (r) {
1297                 DMERR("unable to determine table type");
1298                 return r;
1299         }
1300
1301         r = dm_table_build_index(t);
1302         if (r) {
1303                 DMERR("unable to build btrees");
1304                 return r;
1305         }
1306
1307         r = dm_table_register_integrity(t);
1308         if (r) {
1309                 DMERR("could not register integrity profile.");
1310                 return r;
1311         }
1312
1313         r = dm_table_alloc_md_mempools(t, t->md);
1314         if (r)
1315                 DMERR("unable to allocate mempools");
1316
1317         return r;
1318 }
1319
1320 static DEFINE_MUTEX(_event_lock);
1321 void dm_table_event_callback(struct dm_table *t,
1322                              void (*fn)(void *), void *context)
1323 {
1324         mutex_lock(&_event_lock);
1325         t->event_fn = fn;
1326         t->event_context = context;
1327         mutex_unlock(&_event_lock);
1328 }
1329
1330 void dm_table_event(struct dm_table *t)
1331 {
1332         /*
1333          * You can no longer call dm_table_event() from interrupt
1334          * context, use a bottom half instead.
1335          */
1336         BUG_ON(in_interrupt());
1337
1338         mutex_lock(&_event_lock);
1339         if (t->event_fn)
1340                 t->event_fn(t->event_context);
1341         mutex_unlock(&_event_lock);
1342 }
1343 EXPORT_SYMBOL(dm_table_event);
1344
1345 sector_t dm_table_get_size(struct dm_table *t)
1346 {
1347         return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1348 }
1349 EXPORT_SYMBOL(dm_table_get_size);
1350
1351 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index)
1352 {
1353         if (index >= t->num_targets)
1354                 return NULL;
1355
1356         return t->targets + index;
1357 }
1358
1359 /*
1360  * Search the btree for the correct target.
1361  *
1362  * Caller should check returned pointer with dm_target_is_valid()
1363  * to trap I/O beyond end of device.
1364  */
1365 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1366 {
1367         unsigned int l, n = 0, k = 0;
1368         sector_t *node;
1369
1370         for (l = 0; l < t->depth; l++) {
1371                 n = get_child(n, k);
1372                 node = get_node(t, l, n);
1373
1374                 for (k = 0; k < KEYS_PER_NODE; k++)
1375                         if (node[k] >= sector)
1376                                 break;
1377         }
1378
1379         return &t->targets[(KEYS_PER_NODE * n) + k];
1380 }
1381
1382 static int count_device(struct dm_target *ti, struct dm_dev *dev,
1383                         sector_t start, sector_t len, void *data)
1384 {
1385         unsigned *num_devices = data;
1386
1387         (*num_devices)++;
1388
1389         return 0;
1390 }
1391
1392 /*
1393  * Check whether a table has no data devices attached using each
1394  * target's iterate_devices method.
1395  * Returns false if the result is unknown because a target doesn't
1396  * support iterate_devices.
1397  */
1398 bool dm_table_has_no_data_devices(struct dm_table *table)
1399 {
1400         struct dm_target *ti;
1401         unsigned i, num_devices;
1402
1403         for (i = 0; i < dm_table_get_num_targets(table); i++) {
1404                 ti = dm_table_get_target(table, i);
1405
1406                 if (!ti->type->iterate_devices)
1407                         return false;
1408
1409                 num_devices = 0;
1410                 ti->type->iterate_devices(ti, count_device, &num_devices);
1411                 if (num_devices)
1412                         return false;
1413         }
1414
1415         return true;
1416 }
1417
1418 static int device_is_zoned_model(struct dm_target *ti, struct dm_dev *dev,
1419                                  sector_t start, sector_t len, void *data)
1420 {
1421         struct request_queue *q = bdev_get_queue(dev->bdev);
1422         enum blk_zoned_model *zoned_model = data;
1423
1424         return q && blk_queue_zoned_model(q) == *zoned_model;
1425 }
1426
1427 static bool dm_table_supports_zoned_model(struct dm_table *t,
1428                                           enum blk_zoned_model zoned_model)
1429 {
1430         struct dm_target *ti;
1431         unsigned i;
1432
1433         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1434                 ti = dm_table_get_target(t, i);
1435
1436                 if (zoned_model == BLK_ZONED_HM &&
1437                     !dm_target_supports_zoned_hm(ti->type))
1438                         return false;
1439
1440                 if (!ti->type->iterate_devices ||
1441                     !ti->type->iterate_devices(ti, device_is_zoned_model, &zoned_model))
1442                         return false;
1443         }
1444
1445         return true;
1446 }
1447
1448 static int device_matches_zone_sectors(struct dm_target *ti, struct dm_dev *dev,
1449                                        sector_t start, sector_t len, void *data)
1450 {
1451         struct request_queue *q = bdev_get_queue(dev->bdev);
1452         unsigned int *zone_sectors = data;
1453
1454         return q && blk_queue_zone_sectors(q) == *zone_sectors;
1455 }
1456
1457 static bool dm_table_matches_zone_sectors(struct dm_table *t,
1458                                           unsigned int zone_sectors)
1459 {
1460         struct dm_target *ti;
1461         unsigned i;
1462
1463         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1464                 ti = dm_table_get_target(t, i);
1465
1466                 if (!ti->type->iterate_devices ||
1467                     !ti->type->iterate_devices(ti, device_matches_zone_sectors, &zone_sectors))
1468                         return false;
1469         }
1470
1471         return true;
1472 }
1473
1474 static int validate_hardware_zoned_model(struct dm_table *table,
1475                                          enum blk_zoned_model zoned_model,
1476                                          unsigned int zone_sectors)
1477 {
1478         if (zoned_model == BLK_ZONED_NONE)
1479                 return 0;
1480
1481         if (!dm_table_supports_zoned_model(table, zoned_model)) {
1482                 DMERR("%s: zoned model is not consistent across all devices",
1483                       dm_device_name(table->md));
1484                 return -EINVAL;
1485         }
1486
1487         /* Check zone size validity and compatibility */
1488         if (!zone_sectors || !is_power_of_2(zone_sectors))
1489                 return -EINVAL;
1490
1491         if (!dm_table_matches_zone_sectors(table, zone_sectors)) {
1492                 DMERR("%s: zone sectors is not consistent across all devices",
1493                       dm_device_name(table->md));
1494                 return -EINVAL;
1495         }
1496
1497         return 0;
1498 }
1499
1500 /*
1501  * Establish the new table's queue_limits and validate them.
1502  */
1503 int dm_calculate_queue_limits(struct dm_table *table,
1504                               struct queue_limits *limits)
1505 {
1506         struct dm_target *ti;
1507         struct queue_limits ti_limits;
1508         unsigned i;
1509         enum blk_zoned_model zoned_model = BLK_ZONED_NONE;
1510         unsigned int zone_sectors = 0;
1511
1512         blk_set_stacking_limits(limits);
1513
1514         for (i = 0; i < dm_table_get_num_targets(table); i++) {
1515                 blk_set_stacking_limits(&ti_limits);
1516
1517                 ti = dm_table_get_target(table, i);
1518
1519                 if (!ti->type->iterate_devices)
1520                         goto combine_limits;
1521
1522                 /*
1523                  * Combine queue limits of all the devices this target uses.
1524                  */
1525                 ti->type->iterate_devices(ti, dm_set_device_limits,
1526                                           &ti_limits);
1527
1528                 if (zoned_model == BLK_ZONED_NONE && ti_limits.zoned != BLK_ZONED_NONE) {
1529                         /*
1530                          * After stacking all limits, validate all devices
1531                          * in table support this zoned model and zone sectors.
1532                          */
1533                         zoned_model = ti_limits.zoned;
1534                         zone_sectors = ti_limits.chunk_sectors;
1535                 }
1536
1537                 /* Set I/O hints portion of queue limits */
1538                 if (ti->type->io_hints)
1539                         ti->type->io_hints(ti, &ti_limits);
1540
1541                 /*
1542                  * Check each device area is consistent with the target's
1543                  * overall queue limits.
1544                  */
1545                 if (ti->type->iterate_devices(ti, device_area_is_invalid,
1546                                               &ti_limits))
1547                         return -EINVAL;
1548
1549 combine_limits:
1550                 /*
1551                  * Merge this target's queue limits into the overall limits
1552                  * for the table.
1553                  */
1554                 if (blk_stack_limits(limits, &ti_limits, 0) < 0)
1555                         DMWARN("%s: adding target device "
1556                                "(start sect %llu len %llu) "
1557                                "caused an alignment inconsistency",
1558                                dm_device_name(table->md),
1559                                (unsigned long long) ti->begin,
1560                                (unsigned long long) ti->len);
1561
1562                 /*
1563                  * FIXME: this should likely be moved to blk_stack_limits(), would
1564                  * also eliminate limits->zoned stacking hack in dm_set_device_limits()
1565                  */
1566                 if (limits->zoned == BLK_ZONED_NONE && ti_limits.zoned != BLK_ZONED_NONE) {
1567                         /*
1568                          * By default, the stacked limits zoned model is set to
1569                          * BLK_ZONED_NONE in blk_set_stacking_limits(). Update
1570                          * this model using the first target model reported
1571                          * that is not BLK_ZONED_NONE. This will be either the
1572                          * first target device zoned model or the model reported
1573                          * by the target .io_hints.
1574                          */
1575                         limits->zoned = ti_limits.zoned;
1576                 }
1577         }
1578
1579         /*
1580          * Verify that the zoned model and zone sectors, as determined before
1581          * any .io_hints override, are the same across all devices in the table.
1582          * - this is especially relevant if .io_hints is emulating a disk-managed
1583          *   zoned model (aka BLK_ZONED_NONE) on host-managed zoned block devices.
1584          * BUT...
1585          */
1586         if (limits->zoned != BLK_ZONED_NONE) {
1587                 /*
1588                  * ...IF the above limits stacking determined a zoned model
1589                  * validate that all of the table's devices conform to it.
1590                  */
1591                 zoned_model = limits->zoned;
1592                 zone_sectors = limits->chunk_sectors;
1593         }
1594         if (validate_hardware_zoned_model(table, zoned_model, zone_sectors))
1595                 return -EINVAL;
1596
1597         return validate_hardware_logical_block_alignment(table, limits);
1598 }
1599
1600 /*
1601  * Verify that all devices have an integrity profile that matches the
1602  * DM device's registered integrity profile.  If the profiles don't
1603  * match then unregister the DM device's integrity profile.
1604  */
1605 static void dm_table_verify_integrity(struct dm_table *t)
1606 {
1607         struct gendisk *template_disk = NULL;
1608
1609         if (t->integrity_added)
1610                 return;
1611
1612         if (t->integrity_supported) {
1613                 /*
1614                  * Verify that the original integrity profile
1615                  * matches all the devices in this table.
1616                  */
1617                 template_disk = dm_table_get_integrity_disk(t);
1618                 if (template_disk &&
1619                     blk_integrity_compare(dm_disk(t->md), template_disk) >= 0)
1620                         return;
1621         }
1622
1623         if (integrity_profile_exists(dm_disk(t->md))) {
1624                 DMWARN("%s: unable to establish an integrity profile",
1625                        dm_device_name(t->md));
1626                 blk_integrity_unregister(dm_disk(t->md));
1627         }
1628 }
1629
1630 static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
1631                                 sector_t start, sector_t len, void *data)
1632 {
1633         unsigned long flush = (unsigned long) data;
1634         struct request_queue *q = bdev_get_queue(dev->bdev);
1635
1636         return q && (q->queue_flags & flush);
1637 }
1638
1639 static bool dm_table_supports_flush(struct dm_table *t, unsigned long flush)
1640 {
1641         struct dm_target *ti;
1642         unsigned i;
1643
1644         /*
1645          * Require at least one underlying device to support flushes.
1646          * t->devices includes internal dm devices such as mirror logs
1647          * so we need to use iterate_devices here, which targets
1648          * supporting flushes must provide.
1649          */
1650         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1651                 ti = dm_table_get_target(t, i);
1652
1653                 if (!ti->num_flush_bios)
1654                         continue;
1655
1656                 if (ti->flush_supported)
1657                         return true;
1658
1659                 if (ti->type->iterate_devices &&
1660                     ti->type->iterate_devices(ti, device_flush_capable, (void *) flush))
1661                         return true;
1662         }
1663
1664         return false;
1665 }
1666
1667 static int device_dax_write_cache_enabled(struct dm_target *ti,
1668                                           struct dm_dev *dev, sector_t start,
1669                                           sector_t len, void *data)
1670 {
1671         struct dax_device *dax_dev = dev->dax_dev;
1672
1673         if (!dax_dev)
1674                 return false;
1675
1676         if (dax_write_cache_enabled(dax_dev))
1677                 return true;
1678         return false;
1679 }
1680
1681 static int dm_table_supports_dax_write_cache(struct dm_table *t)
1682 {
1683         struct dm_target *ti;
1684         unsigned i;
1685
1686         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1687                 ti = dm_table_get_target(t, i);
1688
1689                 if (ti->type->iterate_devices &&
1690                     ti->type->iterate_devices(ti,
1691                                 device_dax_write_cache_enabled, NULL))
1692                         return true;
1693         }
1694
1695         return false;
1696 }
1697
1698 static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev,
1699                             sector_t start, sector_t len, void *data)
1700 {
1701         struct request_queue *q = bdev_get_queue(dev->bdev);
1702
1703         return q && blk_queue_nonrot(q);
1704 }
1705
1706 static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
1707                              sector_t start, sector_t len, void *data)
1708 {
1709         struct request_queue *q = bdev_get_queue(dev->bdev);
1710
1711         return q && !blk_queue_add_random(q);
1712 }
1713
1714 static bool dm_table_all_devices_attribute(struct dm_table *t,
1715                                            iterate_devices_callout_fn func)
1716 {
1717         struct dm_target *ti;
1718         unsigned i;
1719
1720         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1721                 ti = dm_table_get_target(t, i);
1722
1723                 if (!ti->type->iterate_devices ||
1724                     !ti->type->iterate_devices(ti, func, NULL))
1725                         return false;
1726         }
1727
1728         return true;
1729 }
1730
1731 static int device_no_partial_completion(struct dm_target *ti, struct dm_dev *dev,
1732                                         sector_t start, sector_t len, void *data)
1733 {
1734         char b[BDEVNAME_SIZE];
1735
1736         /* For now, NVMe devices are the only devices of this class */
1737         return (strncmp(bdevname(dev->bdev, b), "nvme", 4) == 0);
1738 }
1739
1740 static bool dm_table_does_not_support_partial_completion(struct dm_table *t)
1741 {
1742         return dm_table_all_devices_attribute(t, device_no_partial_completion);
1743 }
1744
1745 static int device_not_write_same_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_same_sectors;
1751 }
1752
1753 static bool dm_table_supports_write_same(struct dm_table *t)
1754 {
1755         struct dm_target *ti;
1756         unsigned i;
1757
1758         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1759                 ti = dm_table_get_target(t, i);
1760
1761                 if (!ti->num_write_same_bios)
1762                         return false;
1763
1764                 if (!ti->type->iterate_devices ||
1765                     ti->type->iterate_devices(ti, device_not_write_same_capable, NULL))
1766                         return false;
1767         }
1768
1769         return true;
1770 }
1771
1772 static int device_not_write_zeroes_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 && !q->limits.max_write_zeroes_sectors;
1778 }
1779
1780 static bool dm_table_supports_write_zeroes(struct dm_table *t)
1781 {
1782         struct dm_target *ti;
1783         unsigned i = 0;
1784
1785         while (i < dm_table_get_num_targets(t)) {
1786                 ti = dm_table_get_target(t, i++);
1787
1788                 if (!ti->num_write_zeroes_bios)
1789                         return false;
1790
1791                 if (!ti->type->iterate_devices ||
1792                     ti->type->iterate_devices(ti, device_not_write_zeroes_capable, NULL))
1793                         return false;
1794         }
1795
1796         return true;
1797 }
1798
1799 static int device_not_discard_capable(struct dm_target *ti, struct dm_dev *dev,
1800                                       sector_t start, sector_t len, void *data)
1801 {
1802         struct request_queue *q = bdev_get_queue(dev->bdev);
1803
1804         return q && !blk_queue_discard(q);
1805 }
1806
1807 static bool dm_table_supports_discards(struct dm_table *t)
1808 {
1809         struct dm_target *ti;
1810         unsigned i;
1811
1812         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1813                 ti = dm_table_get_target(t, i);
1814
1815                 if (!ti->num_discard_bios)
1816                         return false;
1817
1818                 /*
1819                  * Either the target provides discard support (as implied by setting
1820                  * 'discards_supported') or it relies on _all_ data devices having
1821                  * discard support.
1822                  */
1823                 if (!ti->discards_supported &&
1824                     (!ti->type->iterate_devices ||
1825                      ti->type->iterate_devices(ti, device_not_discard_capable, NULL)))
1826                         return false;
1827         }
1828
1829         return true;
1830 }
1831
1832 static int device_not_secure_erase_capable(struct dm_target *ti,
1833                                            struct dm_dev *dev, sector_t start,
1834                                            sector_t len, void *data)
1835 {
1836         struct request_queue *q = bdev_get_queue(dev->bdev);
1837
1838         return q && !blk_queue_secure_erase(q);
1839 }
1840
1841 static bool dm_table_supports_secure_erase(struct dm_table *t)
1842 {
1843         struct dm_target *ti;
1844         unsigned int i;
1845
1846         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1847                 ti = dm_table_get_target(t, i);
1848
1849                 if (!ti->num_secure_erase_bios)
1850                         return false;
1851
1852                 if (!ti->type->iterate_devices ||
1853                     ti->type->iterate_devices(ti, device_not_secure_erase_capable, NULL))
1854                         return false;
1855         }
1856
1857         return true;
1858 }
1859
1860 static int device_requires_stable_pages(struct dm_target *ti,
1861                                         struct dm_dev *dev, sector_t start,
1862                                         sector_t len, void *data)
1863 {
1864         struct request_queue *q = bdev_get_queue(dev->bdev);
1865
1866         return q && bdi_cap_stable_pages_required(q->backing_dev_info);
1867 }
1868
1869 /*
1870  * If any underlying device requires stable pages, a table must require
1871  * them as well.  Only targets that support iterate_devices are considered:
1872  * don't want error, zero, etc to require stable pages.
1873  */
1874 static bool dm_table_requires_stable_pages(struct dm_table *t)
1875 {
1876         struct dm_target *ti;
1877         unsigned i;
1878
1879         for (i = 0; i < dm_table_get_num_targets(t); i++) {
1880                 ti = dm_table_get_target(t, i);
1881
1882                 if (ti->type->iterate_devices &&
1883                     ti->type->iterate_devices(ti, device_requires_stable_pages, NULL))
1884                         return true;
1885         }
1886
1887         return false;
1888 }
1889
1890 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1891                                struct queue_limits *limits)
1892 {
1893         bool wc = false, fua = false;
1894         int page_size = PAGE_SIZE;
1895
1896         /*
1897          * Copy table's limits to the DM device's request_queue
1898          */
1899         q->limits = *limits;
1900
1901         if (!dm_table_supports_discards(t)) {
1902                 blk_queue_flag_clear(QUEUE_FLAG_DISCARD, q);
1903                 /* Must also clear discard limits... */
1904                 q->limits.max_discard_sectors = 0;
1905                 q->limits.max_hw_discard_sectors = 0;
1906                 q->limits.discard_granularity = 0;
1907                 q->limits.discard_alignment = 0;
1908                 q->limits.discard_misaligned = 0;
1909         } else
1910                 blk_queue_flag_set(QUEUE_FLAG_DISCARD, q);
1911
1912         if (dm_table_supports_secure_erase(t))
1913                 blk_queue_flag_set(QUEUE_FLAG_SECERASE, q);
1914
1915         if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_WC))) {
1916                 wc = true;
1917                 if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_FUA)))
1918                         fua = true;
1919         }
1920         blk_queue_write_cache(q, wc, fua);
1921
1922         if (dm_table_supports_dax(t, device_supports_dax, &page_size)) {
1923                 blk_queue_flag_set(QUEUE_FLAG_DAX, q);
1924                 if (dm_table_supports_dax(t, device_dax_synchronous, NULL))
1925                         set_dax_synchronous(t->md->dax_dev);
1926         }
1927         else
1928                 blk_queue_flag_clear(QUEUE_FLAG_DAX, q);
1929
1930         if (dm_table_supports_dax_write_cache(t))
1931                 dax_write_cache(t->md->dax_dev, true);
1932
1933         /* Ensure that all underlying devices are non-rotational. */
1934         if (dm_table_all_devices_attribute(t, device_is_nonrot))
1935                 blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
1936         else
1937                 blk_queue_flag_clear(QUEUE_FLAG_NONROT, q);
1938
1939         if (!dm_table_supports_write_same(t))
1940                 q->limits.max_write_same_sectors = 0;
1941         if (!dm_table_supports_write_zeroes(t))
1942                 q->limits.max_write_zeroes_sectors = 0;
1943
1944         dm_table_verify_integrity(t);
1945
1946         /*
1947          * Some devices don't use blk_integrity but still want stable pages
1948          * because they do their own checksumming.
1949          */
1950         if (dm_table_requires_stable_pages(t))
1951                 q->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES;
1952         else
1953                 q->backing_dev_info->capabilities &= ~BDI_CAP_STABLE_WRITES;
1954
1955         /*
1956          * Determine whether or not this queue's I/O timings contribute
1957          * to the entropy pool, Only request-based targets use this.
1958          * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
1959          * have it set.
1960          */
1961         if (blk_queue_add_random(q) && dm_table_all_devices_attribute(t, device_is_not_random))
1962                 blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, q);
1963
1964         /*
1965          * For a zoned target, the number of zones should be updated for the
1966          * correct value to be exposed in sysfs queue/nr_zones. For a BIO based
1967          * target, this is all that is needed. For a request based target, the
1968          * queue zone bitmaps must also be updated.
1969          * Use blk_revalidate_disk_zones() to handle this.
1970          */
1971         if (blk_queue_is_zoned(q))
1972                 blk_revalidate_disk_zones(t->md->disk);
1973
1974         /* Allow reads to exceed readahead limits */
1975         q->backing_dev_info->io_pages = limits->max_sectors >> (PAGE_SHIFT - 9);
1976 }
1977
1978 unsigned int dm_table_get_num_targets(struct dm_table *t)
1979 {
1980         return t->num_targets;
1981 }
1982
1983 struct list_head *dm_table_get_devices(struct dm_table *t)
1984 {
1985         return &t->devices;
1986 }
1987
1988 fmode_t dm_table_get_mode(struct dm_table *t)
1989 {
1990         return t->mode;
1991 }
1992 EXPORT_SYMBOL(dm_table_get_mode);
1993
1994 enum suspend_mode {
1995         PRESUSPEND,
1996         PRESUSPEND_UNDO,
1997         POSTSUSPEND,
1998 };
1999
2000 static void suspend_targets(struct dm_table *t, enum suspend_mode mode)
2001 {
2002         int i = t->num_targets;
2003         struct dm_target *ti = t->targets;
2004
2005         lockdep_assert_held(&t->md->suspend_lock);
2006
2007         while (i--) {
2008                 switch (mode) {
2009                 case PRESUSPEND:
2010                         if (ti->type->presuspend)
2011                                 ti->type->presuspend(ti);
2012                         break;
2013                 case PRESUSPEND_UNDO:
2014                         if (ti->type->presuspend_undo)
2015                                 ti->type->presuspend_undo(ti);
2016                         break;
2017                 case POSTSUSPEND:
2018                         if (ti->type->postsuspend)
2019                                 ti->type->postsuspend(ti);
2020                         break;
2021                 }
2022                 ti++;
2023         }
2024 }
2025
2026 void dm_table_presuspend_targets(struct dm_table *t)
2027 {
2028         if (!t)
2029                 return;
2030
2031         suspend_targets(t, PRESUSPEND);
2032 }
2033
2034 void dm_table_presuspend_undo_targets(struct dm_table *t)
2035 {
2036         if (!t)
2037                 return;
2038
2039         suspend_targets(t, PRESUSPEND_UNDO);
2040 }
2041
2042 void dm_table_postsuspend_targets(struct dm_table *t)
2043 {
2044         if (!t)
2045                 return;
2046
2047         suspend_targets(t, POSTSUSPEND);
2048 }
2049
2050 int dm_table_resume_targets(struct dm_table *t)
2051 {
2052         int i, r = 0;
2053
2054         lockdep_assert_held(&t->md->suspend_lock);
2055
2056         for (i = 0; i < t->num_targets; i++) {
2057                 struct dm_target *ti = t->targets + i;
2058
2059                 if (!ti->type->preresume)
2060                         continue;
2061
2062                 r = ti->type->preresume(ti);
2063                 if (r) {
2064                         DMERR("%s: %s: preresume failed, error = %d",
2065                               dm_device_name(t->md), ti->type->name, r);
2066                         return r;
2067                 }
2068         }
2069
2070         for (i = 0; i < t->num_targets; i++) {
2071                 struct dm_target *ti = t->targets + i;
2072
2073                 if (ti->type->resume)
2074                         ti->type->resume(ti);
2075         }
2076
2077         return 0;
2078 }
2079
2080 void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb)
2081 {
2082         list_add(&cb->list, &t->target_callbacks);
2083 }
2084 EXPORT_SYMBOL_GPL(dm_table_add_target_callbacks);
2085
2086 int dm_table_any_congested(struct dm_table *t, int bdi_bits)
2087 {
2088         struct dm_dev_internal *dd;
2089         struct list_head *devices = dm_table_get_devices(t);
2090         struct dm_target_callbacks *cb;
2091         int r = 0;
2092
2093         list_for_each_entry(dd, devices, list) {
2094                 struct request_queue *q = bdev_get_queue(dd->dm_dev->bdev);
2095                 char b[BDEVNAME_SIZE];
2096
2097                 if (likely(q))
2098                         r |= bdi_congested(q->backing_dev_info, bdi_bits);
2099                 else
2100                         DMWARN_LIMIT("%s: any_congested: nonexistent device %s",
2101                                      dm_device_name(t->md),
2102                                      bdevname(dd->dm_dev->bdev, b));
2103         }
2104
2105         list_for_each_entry(cb, &t->target_callbacks, list)
2106                 if (cb->congested_fn)
2107                         r |= cb->congested_fn(cb, bdi_bits);
2108
2109         return r;
2110 }
2111
2112 struct mapped_device *dm_table_get_md(struct dm_table *t)
2113 {
2114         return t->md;
2115 }
2116 EXPORT_SYMBOL(dm_table_get_md);
2117
2118 const char *dm_table_device_name(struct dm_table *t)
2119 {
2120         return dm_device_name(t->md);
2121 }
2122 EXPORT_SYMBOL_GPL(dm_table_device_name);
2123
2124 void dm_table_run_md_queue_async(struct dm_table *t)
2125 {
2126         struct mapped_device *md;
2127         struct request_queue *queue;
2128
2129         if (!dm_table_request_based(t))
2130                 return;
2131
2132         md = dm_table_get_md(t);
2133         queue = dm_get_md_queue(md);
2134         if (queue)
2135                 blk_mq_run_hw_queues(queue, true);
2136 }
2137 EXPORT_SYMBOL(dm_table_run_md_queue_async);
2138