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
  32struct 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 */
  74static 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 */
  89static 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 */
  97static 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 */
 107static 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 */
 122static 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
 137void *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}
 153EXPORT_SYMBOL(dm_vcalloc);
 154
 155/*
 156 * highs, and targets are managed as dynamic arrays during a
 157 * table load.
 158 */
 159static 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
 184int 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
 217static 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
 231void 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 */
 265static 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 */
 279static 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 request_queue *q;
 283	struct queue_limits *limits = data;
 284	struct block_device *bdev = dev->bdev;
 285	sector_t dev_size =
 286		i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
 287	unsigned short logical_block_size_sectors =
 288		limits->logical_block_size >> SECTOR_SHIFT;
 289	char b[BDEVNAME_SIZE];
 290
 291	/*
 292	 * Some devices exist without request functions,
 293	 * such as loop devices not yet bound to backing files.
 294	 * Forbid the use of such devices.
 295	 */
 296	q = bdev_get_queue(bdev);
 297	if (!q || !q->make_request_fn) {
 298		DMWARN("%s: %s is not yet initialised: "
 299		       "start=%llu, len=%llu, dev_size=%llu",
 300		       dm_device_name(ti->table->md), bdevname(bdev, b),
 301		       (unsigned long long)start,
 302		       (unsigned long long)len,
 303		       (unsigned long long)dev_size);
 304		return 1;
 305	}
 306
 307	if (!dev_size)
 308		return 0;
 309
 310	if ((start >= dev_size) || (start + len > dev_size)) {
 311		DMWARN("%s: %s too small for target: "
 312		       "start=%llu, len=%llu, dev_size=%llu",
 313		       dm_device_name(ti->table->md), bdevname(bdev, b),
 314		       (unsigned long long)start,
 315		       (unsigned long long)len,
 316		       (unsigned long long)dev_size);
 317		return 1;
 318	}
 319
 320	/*
 321	 * If the target is mapped to zoned block device(s), check
 322	 * that the zones are not partially mapped.
 323	 */
 324	if (bdev_zoned_model(bdev) != BLK_ZONED_NONE) {
 325		unsigned int zone_sectors = bdev_zone_sectors(bdev);
 326
 327		if (start & (zone_sectors - 1)) {
 328			DMWARN("%s: start=%llu not aligned to h/w zone size %u of %s",
 329			       dm_device_name(ti->table->md),
 330			       (unsigned long long)start,
 331			       zone_sectors, bdevname(bdev, b));
 332			return 1;
 333		}
 334
 335		/*
 336		 * Note: The last zone of a zoned block device may be smaller
 337		 * than other zones. So for a target mapping the end of a
 338		 * zoned block device with such a zone, len would not be zone
 339		 * aligned. We do not allow such last smaller zone to be part
 340		 * of the mapping here to ensure that mappings with multiple
 341		 * devices do not end up with a smaller zone in the middle of
 342		 * the sector range.
 343		 */
 344		if (len & (zone_sectors - 1)) {
 345			DMWARN("%s: len=%llu not aligned to h/w zone size %u of %s",
 346			       dm_device_name(ti->table->md),
 347			       (unsigned long long)len,
 348			       zone_sectors, bdevname(bdev, b));
 349			return 1;
 350		}
 351	}
 352
 353	if (logical_block_size_sectors <= 1)
 354		return 0;
 355
 356	if (start & (logical_block_size_sectors - 1)) {
 357		DMWARN("%s: start=%llu not aligned to h/w "
 358		       "logical block size %u of %s",
 359		       dm_device_name(ti->table->md),
 360		       (unsigned long long)start,
 361		       limits->logical_block_size, bdevname(bdev, b));
 362		return 1;
 363	}
 364
 365	if (len & (logical_block_size_sectors - 1)) {
 366		DMWARN("%s: len=%llu not aligned to h/w "
 367		       "logical block size %u of %s",
 368		       dm_device_name(ti->table->md),
 369		       (unsigned long long)len,
 370		       limits->logical_block_size, bdevname(bdev, b));
 371		return 1;
 372	}
 373
 374	return 0;
 375}
 376
 377/*
 378 * This upgrades the mode on an already open dm_dev, being
 379 * careful to leave things as they were if we fail to reopen the
 380 * device and not to touch the existing bdev field in case
 381 * it is accessed concurrently inside dm_table_any_congested().
 382 */
 383static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
 384			struct mapped_device *md)
 385{
 386	int r;
 387	struct dm_dev *old_dev, *new_dev;
 388
 389	old_dev = dd->dm_dev;
 390
 391	r = dm_get_table_device(md, dd->dm_dev->bdev->bd_dev,
 392				dd->dm_dev->mode | new_mode, &new_dev);
 393	if (r)
 394		return r;
 395
 396	dd->dm_dev = new_dev;
 397	dm_put_table_device(md, old_dev);
 398
 399	return 0;
 400}
 401
 402/*
 403 * Convert the path to a device
 404 */
 405dev_t dm_get_dev_t(const char *path)
 406{
 407	dev_t dev;
 408	struct block_device *bdev;
 409
 410	bdev = lookup_bdev(path);
 411	if (IS_ERR(bdev))
 412		dev = name_to_dev_t(path);
 413	else {
 414		dev = bdev->bd_dev;
 415		bdput(bdev);
 416	}
 417
 418	return dev;
 419}
 420EXPORT_SYMBOL_GPL(dm_get_dev_t);
 421
 422/*
 423 * Add a device to the list, or just increment the usage count if
 424 * it's already present.
 425 */
 426int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
 427		  struct dm_dev **result)
 428{
 429	int r;
 430	dev_t dev;
 431	struct dm_dev_internal *dd;
 432	struct dm_table *t = ti->table;
 433
 434	BUG_ON(!t);
 435
 436	dev = dm_get_dev_t(path);
 437	if (!dev)
 438		return -ENODEV;
 439
 440	dd = find_device(&t->devices, dev);
 441	if (!dd) {
 442		dd = kmalloc(sizeof(*dd), GFP_KERNEL);
 443		if (!dd)
 444			return -ENOMEM;
 445
 446		if ((r = dm_get_table_device(t->md, dev, mode, &dd->dm_dev))) {
 447			kfree(dd);
 448			return r;
 449		}
 450
 451		refcount_set(&dd->count, 1);
 452		list_add(&dd->list, &t->devices);
 453		goto out;
 454
 455	} else if (dd->dm_dev->mode != (mode | dd->dm_dev->mode)) {
 456		r = upgrade_mode(dd, mode, t->md);
 457		if (r)
 458			return r;
 459	}
 460	refcount_inc(&dd->count);
 461out:
 462	*result = dd->dm_dev;
 463	return 0;
 464}
 465EXPORT_SYMBOL(dm_get_device);
 466
 467static int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
 468				sector_t start, sector_t len, void *data)
 469{
 470	struct queue_limits *limits = data;
 471	struct block_device *bdev = dev->bdev;
 472	struct request_queue *q = bdev_get_queue(bdev);
 473	char b[BDEVNAME_SIZE];
 474
 475	if (unlikely(!q)) {
 476		DMWARN("%s: Cannot set limits for nonexistent device %s",
 477		       dm_device_name(ti->table->md), bdevname(bdev, b));
 478		return 0;
 479	}
 480
 481	if (bdev_stack_limits(limits, bdev, start) < 0)
 482		DMWARN("%s: adding target device %s caused an alignment inconsistency: "
 483		       "physical_block_size=%u, logical_block_size=%u, "
 484		       "alignment_offset=%u, start=%llu",
 485		       dm_device_name(ti->table->md), bdevname(bdev, b),
 486		       q->limits.physical_block_size,
 487		       q->limits.logical_block_size,
 488		       q->limits.alignment_offset,
 489		       (unsigned long long) start << SECTOR_SHIFT);
 490
 491	limits->zoned = blk_queue_zoned_model(q);
 492
 493	return 0;
 494}
 495
 496/*
 497 * Decrement a device's use count and remove it if necessary.
 498 */
 499void dm_put_device(struct dm_target *ti, struct dm_dev *d)
 500{
 501	int found = 0;
 502	struct list_head *devices = &ti->table->devices;
 503	struct dm_dev_internal *dd;
 504
 505	list_for_each_entry(dd, devices, list) {
 506		if (dd->dm_dev == d) {
 507			found = 1;
 508			break;
 509		}
 510	}
 511	if (!found) {
 512		DMWARN("%s: device %s not in table devices list",
 513		       dm_device_name(ti->table->md), d->name);
 514		return;
 515	}
 516	if (refcount_dec_and_test(&dd->count)) {
 517		dm_put_table_device(ti->table->md, d);
 518		list_del(&dd->list);
 519		kfree(dd);
 520	}
 521}
 522EXPORT_SYMBOL(dm_put_device);
 523
 524/*
 525 * Checks to see if the target joins onto the end of the table.
 526 */
 527static int adjoin(struct dm_table *table, struct dm_target *ti)
 528{
 529	struct dm_target *prev;
 530
 531	if (!table->num_targets)
 532		return !ti->begin;
 533
 534	prev = &table->targets[table->num_targets - 1];
 535	return (ti->begin == (prev->begin + prev->len));
 536}
 537
 538/*
 539 * Used to dynamically allocate the arg array.
 540 *
 541 * We do first allocation with GFP_NOIO because dm-mpath and dm-thin must
 542 * process messages even if some device is suspended. These messages have a
 543 * small fixed number of arguments.
 544 *
 545 * On the other hand, dm-switch needs to process bulk data using messages and
 546 * excessive use of GFP_NOIO could cause trouble.
 547 */
 548static char **realloc_argv(unsigned *size, char **old_argv)
 549{
 550	char **argv;
 551	unsigned new_size;
 552	gfp_t gfp;
 553
 554	if (*size) {
 555		new_size = *size * 2;
 556		gfp = GFP_KERNEL;
 557	} else {
 558		new_size = 8;
 559		gfp = GFP_NOIO;
 560	}
 561	argv = kmalloc_array(new_size, sizeof(*argv), gfp);
 562	if (argv && old_argv) {
 563		memcpy(argv, old_argv, *size * sizeof(*argv));
 564		*size = new_size;
 565	}
 566
 567	kfree(old_argv);
 568	return argv;
 569}
 570
 571/*
 572 * Destructively splits up the argument list to pass to ctr.
 573 */
 574int dm_split_args(int *argc, char ***argvp, char *input)
 575{
 576	char *start, *end = input, *out, **argv = NULL;
 577	unsigned array_size = 0;
 578
 579	*argc = 0;
 580
 581	if (!input) {
 582		*argvp = NULL;
 583		return 0;
 584	}
 585
 586	argv = realloc_argv(&array_size, argv);
 587	if (!argv)
 588		return -ENOMEM;
 589
 590	while (1) {
 591		/* Skip whitespace */
 592		start = skip_spaces(end);
 593
 594		if (!*start)
 595			break;	/* success, we hit the end */
 596
 597		/* 'out' is used to remove any back-quotes */
 598		end = out = start;
 599		while (*end) {
 600			/* Everything apart from '\0' can be quoted */
 601			if (*end == '\\' && *(end + 1)) {
 602				*out++ = *(end + 1);
 603				end += 2;
 604				continue;
 605			}
 606
 607			if (isspace(*end))
 608				break;	/* end of token */
 609
 610			*out++ = *end++;
 611		}
 612
 613		/* have we already filled the array ? */
 614		if ((*argc + 1) > array_size) {
 615			argv = realloc_argv(&array_size, argv);
 616			if (!argv)
 617				return -ENOMEM;
 618		}
 619
 620		/* we know this is whitespace */
 621		if (*end)
 622			end++;
 623
 624		/* terminate the string and put it in the array */
 625		*out = '\0';
 626		argv[*argc] = start;
 627		(*argc)++;
 628	}
 629
 630	*argvp = argv;
 631	return 0;
 632}
 633
 634/*
 635 * Impose necessary and sufficient conditions on a devices's table such
 636 * that any incoming bio which respects its logical_block_size can be
 637 * processed successfully.  If it falls across the boundary between
 638 * two or more targets, the size of each piece it gets split into must
 639 * be compatible with the logical_block_size of the target processing it.
 640 */
 641static int validate_hardware_logical_block_alignment(struct dm_table *table,
 642						 struct queue_limits *limits)
 643{
 644	/*
 645	 * This function uses arithmetic modulo the logical_block_size
 646	 * (in units of 512-byte sectors).
 647	 */
 648	unsigned short device_logical_block_size_sects =
 649		limits->logical_block_size >> SECTOR_SHIFT;
 650
 651	/*
 652	 * Offset of the start of the next table entry, mod logical_block_size.
 653	 */
 654	unsigned short next_target_start = 0;
 655
 656	/*
 657	 * Given an aligned bio that extends beyond the end of a
 658	 * target, how many sectors must the next target handle?
 659	 */
 660	unsigned short remaining = 0;
 661
 662	struct dm_target *uninitialized_var(ti);
 663	struct queue_limits ti_limits;
 664	unsigned i;
 665
 666	/*
 667	 * Check each entry in the table in turn.
 668	 */
 669	for (i = 0; i < dm_table_get_num_targets(table); i++) {
 670		ti = dm_table_get_target(table, i);
 671
 672		blk_set_stacking_limits(&ti_limits);
 673
 674		/* combine all target devices' limits */
 675		if (ti->type->iterate_devices)
 676			ti->type->iterate_devices(ti, dm_set_device_limits,
 677						  &ti_limits);
 678
 679		/*
 680		 * If the remaining sectors fall entirely within this
 681		 * table entry are they compatible with its logical_block_size?
 682		 */
 683		if (remaining < ti->len &&
 684		    remaining & ((ti_limits.logical_block_size >>
 685				  SECTOR_SHIFT) - 1))
 686			break;	/* Error */
 687
 688		next_target_start =
 689		    (unsigned short) ((next_target_start + ti->len) &
 690				      (device_logical_block_size_sects - 1));
 691		remaining = next_target_start ?
 692		    device_logical_block_size_sects - next_target_start : 0;
 693	}
 694
 695	if (remaining) {
 696		DMWARN("%s: table line %u (start sect %llu len %llu) "
 697		       "not aligned to h/w logical block size %u",
 698		       dm_device_name(table->md), i,
 699		       (unsigned long long) ti->begin,
 700		       (unsigned long long) ti->len,
 701		       limits->logical_block_size);
 702		return -EINVAL;
 703	}
 704
 705	return 0;
 706}
 707
 708int dm_table_add_target(struct dm_table *t, const char *type,
 709			sector_t start, sector_t len, char *params)
 710{
 711	int r = -EINVAL, argc;
 712	char **argv;
 713	struct dm_target *tgt;
 714
 715	if (t->singleton) {
 716		DMERR("%s: target type %s must appear alone in table",
 717		      dm_device_name(t->md), t->targets->type->name);
 718		return -EINVAL;
 719	}
 720
 721	BUG_ON(t->num_targets >= t->num_allocated);
 722
 723	tgt = t->targets + t->num_targets;
 724	memset(tgt, 0, sizeof(*tgt));
 725
 726	if (!len) {
 727		DMERR("%s: zero-length target", dm_device_name(t->md));
 728		return -EINVAL;
 729	}
 730
 731	tgt->type = dm_get_target_type(type);
 732	if (!tgt->type) {
 733		DMERR("%s: %s: unknown target type", dm_device_name(t->md), type);
 734		return -EINVAL;
 735	}
 736
 737	if (dm_target_needs_singleton(tgt->type)) {
 738		if (t->num_targets) {
 739			tgt->error = "singleton target type must appear alone in table";
 740			goto bad;
 741		}
 742		t->singleton = true;
 743	}
 744
 745	if (dm_target_always_writeable(tgt->type) && !(t->mode & FMODE_WRITE)) {
 746		tgt->error = "target type may not be included in a read-only table";
 747		goto bad;
 748	}
 749
 750	if (t->immutable_target_type) {
 751		if (t->immutable_target_type != tgt->type) {
 752			tgt->error = "immutable target type cannot be mixed with other target types";
 753			goto bad;
 754		}
 755	} else if (dm_target_is_immutable(tgt->type)) {
 756		if (t->num_targets) {
 757			tgt->error = "immutable target type cannot be mixed with other target types";
 758			goto bad;
 759		}
 760		t->immutable_target_type = tgt->type;
 761	}
 762
 763	if (dm_target_has_integrity(tgt->type))
 764		t->integrity_added = 1;
 765
 766	tgt->table = t;
 767	tgt->begin = start;
 768	tgt->len = len;
 769	tgt->error = "Unknown error";
 770
 771	/*
 772	 * Does this target adjoin the previous one ?
 773	 */
 774	if (!adjoin(t, tgt)) {
 775		tgt->error = "Gap in table";
 776		goto bad;
 777	}
 778
 779	r = dm_split_args(&argc, &argv, params);
 780	if (r) {
 781		tgt->error = "couldn't split parameters (insufficient memory)";
 782		goto bad;
 783	}
 784
 785	r = tgt->type->ctr(tgt, argc, argv);
 786	kfree(argv);
 787	if (r)
 788		goto bad;
 789
 790	t->highs[t->num_targets++] = tgt->begin + tgt->len - 1;
 791
 792	if (!tgt->num_discard_bios && tgt->discards_supported)
 793		DMWARN("%s: %s: ignoring discards_supported because num_discard_bios is zero.",
 794		       dm_device_name(t->md), type);
 795
 796	return 0;
 797
 798 bad:
 799	DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error);
 800	dm_put_target_type(tgt->type);
 801	return r;
 802}
 803
 804/*
 805 * Target argument parsing helpers.
 806 */
 807static int validate_next_arg(const struct dm_arg *arg,
 808			     struct dm_arg_set *arg_set,
 809			     unsigned *value, char **error, unsigned grouped)
 810{
 811	const char *arg_str = dm_shift_arg(arg_set);
 812	char dummy;
 813
 814	if (!arg_str ||
 815	    (sscanf(arg_str, "%u%c", value, &dummy) != 1) ||
 816	    (*value < arg->min) ||
 817	    (*value > arg->max) ||
 818	    (grouped && arg_set->argc < *value)) {
 819		*error = arg->error;
 820		return -EINVAL;
 821	}
 822
 823	return 0;
 824}
 825
 826int dm_read_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
 827		unsigned *value, char **error)
 828{
 829	return validate_next_arg(arg, arg_set, value, error, 0);
 830}
 831EXPORT_SYMBOL(dm_read_arg);
 832
 833int dm_read_arg_group(const struct dm_arg *arg, struct dm_arg_set *arg_set,
 834		      unsigned *value, char **error)
 835{
 836	return validate_next_arg(arg, arg_set, value, error, 1);
 837}
 838EXPORT_SYMBOL(dm_read_arg_group);
 839
 840const char *dm_shift_arg(struct dm_arg_set *as)
 841{
 842	char *r;
 843
 844	if (as->argc) {
 845		as->argc--;
 846		r = *as->argv;
 847		as->argv++;
 848		return r;
 849	}
 850
 851	return NULL;
 852}
 853EXPORT_SYMBOL(dm_shift_arg);
 854
 855void dm_consume_args(struct dm_arg_set *as, unsigned num_args)
 856{
 857	BUG_ON(as->argc < num_args);
 858	as->argc -= num_args;
 859	as->argv += num_args;
 860}
 861EXPORT_SYMBOL(dm_consume_args);
 862
 863static bool __table_type_bio_based(enum dm_queue_mode table_type)
 864{
 865	return (table_type == DM_TYPE_BIO_BASED ||
 866		table_type == DM_TYPE_DAX_BIO_BASED ||
 867		table_type == DM_TYPE_NVME_BIO_BASED);
 868}
 869
 870static bool __table_type_request_based(enum dm_queue_mode table_type)
 871{
 872	return table_type == DM_TYPE_REQUEST_BASED;
 
 873}
 874
 875void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type)
 876{
 877	t->type = type;
 878}
 879EXPORT_SYMBOL_GPL(dm_table_set_type);
 880
 881/* validate the dax capability of the target device span */
 882int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,
 883			sector_t start, sector_t len, void *data)
 884{
 885	int blocksize = *(int *) data;
 886
 887	return generic_fsdax_supported(dev->dax_dev, dev->bdev, blocksize,
 888				       start, len);
 889}
 890
 891/* Check devices support synchronous DAX */
 892static int device_dax_synchronous(struct dm_target *ti, struct dm_dev *dev,
 893				  sector_t start, sector_t len, void *data)
 894{
 895	return dev->dax_dev && dax_synchronous(dev->dax_dev);
 896}
 897
 898bool dm_table_supports_dax(struct dm_table *t,
 899			   iterate_devices_callout_fn iterate_fn, int *blocksize)
 900{
 901	struct dm_target *ti;
 902	unsigned i;
 903
 904	/* Ensure that all targets support DAX. */
 905	for (i = 0; i < dm_table_get_num_targets(t); i++) {
 906		ti = dm_table_get_target(t, i);
 907
 908		if (!ti->type->direct_access)
 909			return false;
 910
 911		if (!ti->type->iterate_devices ||
 912		    !ti->type->iterate_devices(ti, iterate_fn, blocksize))
 913			return false;
 914	}
 915
 916	return true;
 917}
 918
 919static bool dm_table_does_not_support_partial_completion(struct dm_table *t);
 920
 921struct verify_rq_based_data {
 922	unsigned sq_count;
 923	unsigned mq_count;
 924};
 925
 926static int device_is_rq_based(struct dm_target *ti, struct dm_dev *dev,
 927			      sector_t start, sector_t len, void *data)
 928{
 929	struct request_queue *q = bdev_get_queue(dev->bdev);
 930	struct verify_rq_based_data *v = data;
 931
 932	if (queue_is_mq(q))
 933		v->mq_count++;
 934	else
 935		v->sq_count++;
 936
 937	return queue_is_mq(q);
 938}
 939
 940static int dm_table_determine_type(struct dm_table *t)
 941{
 942	unsigned i;
 943	unsigned bio_based = 0, request_based = 0, hybrid = 0;
 944	struct verify_rq_based_data v = {.sq_count = 0, .mq_count = 0};
 945	struct dm_target *tgt;
 946	struct list_head *devices = dm_table_get_devices(t);
 947	enum dm_queue_mode live_md_type = dm_get_md_type(t->md);
 948	int page_size = PAGE_SIZE;
 949
 950	if (t->type != DM_TYPE_NONE) {
 951		/* target already set the table's type */
 952		if (t->type == DM_TYPE_BIO_BASED) {
 953			/* possibly upgrade to a variant of bio-based */
 954			goto verify_bio_based;
 955		}
 956		BUG_ON(t->type == DM_TYPE_DAX_BIO_BASED);
 957		BUG_ON(t->type == DM_TYPE_NVME_BIO_BASED);
 958		goto verify_rq_based;
 959	}
 960
 961	for (i = 0; i < t->num_targets; i++) {
 962		tgt = t->targets + i;
 963		if (dm_target_hybrid(tgt))
 964			hybrid = 1;
 965		else if (dm_target_request_based(tgt))
 966			request_based = 1;
 967		else
 968			bio_based = 1;
 969
 970		if (bio_based && request_based) {
 971			DMERR("Inconsistent table: different target types"
 972			      " can't be mixed up");
 973			return -EINVAL;
 974		}
 975	}
 976
 977	if (hybrid && !bio_based && !request_based) {
 978		/*
 979		 * The targets can work either way.
 980		 * Determine the type from the live device.
 981		 * Default to bio-based if device is new.
 982		 */
 983		if (__table_type_request_based(live_md_type))
 984			request_based = 1;
 985		else
 986			bio_based = 1;
 987	}
 988
 989	if (bio_based) {
 990verify_bio_based:
 991		/* We must use this table as bio-based */
 992		t->type = DM_TYPE_BIO_BASED;
 993		if (dm_table_supports_dax(t, device_supports_dax, &page_size) ||
 994		    (list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED)) {
 995			t->type = DM_TYPE_DAX_BIO_BASED;
 996		} else {
 997			/* Check if upgrading to NVMe bio-based is valid or required */
 998			tgt = dm_table_get_immutable_target(t);
 999			if (tgt && !tgt->max_io_len && dm_table_does_not_support_partial_completion(t)) {
1000				t->type = DM_TYPE_NVME_BIO_BASED;
1001				goto verify_rq_based; /* must be stacked directly on NVMe (blk-mq) */
1002			} else if (list_empty(devices) && live_md_type == DM_TYPE_NVME_BIO_BASED) {
1003				t->type = DM_TYPE_NVME_BIO_BASED;
1004			}
1005		}
1006		return 0;
1007	}
1008
1009	BUG_ON(!request_based); /* No targets in this table */
1010
 
 
 
 
1011	t->type = DM_TYPE_REQUEST_BASED;
1012
1013verify_rq_based:
1014	/*
1015	 * Request-based dm supports only tables that have a single target now.
1016	 * To support multiple targets, request splitting support is needed,
1017	 * and that needs lots of changes in the block-layer.
1018	 * (e.g. request completion process for partial completion.)
1019	 */
1020	if (t->num_targets > 1) {
1021		DMERR("%s DM doesn't support multiple targets",
1022		      t->type == DM_TYPE_NVME_BIO_BASED ? "nvme bio-based" : "request-based");
1023		return -EINVAL;
1024	}
1025
1026	if (list_empty(devices)) {
1027		int srcu_idx;
1028		struct dm_table *live_table = dm_get_live_table(t->md, &srcu_idx);
1029
1030		/* inherit live table's type */
1031		if (live_table)
1032			t->type = live_table->type;
 
 
1033		dm_put_live_table(t->md, srcu_idx);
1034		return 0;
1035	}
1036
1037	tgt = dm_table_get_immutable_target(t);
1038	if (!tgt) {
1039		DMERR("table load rejected: immutable target is required");
1040		return -EINVAL;
1041	} else if (tgt->max_io_len) {
1042		DMERR("table load rejected: immutable target that splits IO is not supported");
1043		return -EINVAL;
1044	}
1045
1046	/* Non-request-stackable devices can't be used for request-based dm */
1047	if (!tgt->type->iterate_devices ||
1048	    !tgt->type->iterate_devices(tgt, device_is_rq_based, &v)) {
1049		DMERR("table load rejected: including non-request-stackable devices");
1050		return -EINVAL;
1051	}
1052	if (v.sq_count > 0) {
1053		DMERR("table load rejected: not all devices are blk-mq request-stackable");
1054		return -EINVAL;
1055	}
 
 
 
 
 
 
 
1056
1057	return 0;
1058}
1059
1060enum dm_queue_mode dm_table_get_type(struct dm_table *t)
1061{
1062	return t->type;
1063}
1064
1065struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
1066{
1067	return t->immutable_target_type;
1068}
1069
1070struct dm_target *dm_table_get_immutable_target(struct dm_table *t)
1071{
1072	/* Immutable target is implicitly a singleton */
1073	if (t->num_targets > 1 ||
1074	    !dm_target_is_immutable(t->targets[0].type))
1075		return NULL;
1076
1077	return t->targets;
1078}
1079
1080struct dm_target *dm_table_get_wildcard_target(struct dm_table *t)
1081{
1082	struct dm_target *ti;
1083	unsigned i;
1084
1085	for (i = 0; i < dm_table_get_num_targets(t); i++) {
1086		ti = dm_table_get_target(t, i);
1087		if (dm_target_is_wildcard(ti->type))
1088			return ti;
1089	}
1090
1091	return NULL;
1092}
1093
1094bool dm_table_bio_based(struct dm_table *t)
1095{
1096	return __table_type_bio_based(dm_table_get_type(t));
1097}
1098
1099bool dm_table_request_based(struct dm_table *t)
1100{
1101	return __table_type_request_based(dm_table_get_type(t));
1102}
1103
 
 
 
 
 
1104static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device *md)
1105{
1106	enum dm_queue_mode type = dm_table_get_type(t);
1107	unsigned per_io_data_size = 0;
1108	unsigned min_pool_size = 0;
1109	struct dm_target *ti;
1110	unsigned i;
1111
1112	if (unlikely(type == DM_TYPE_NONE)) {
1113		DMWARN("no table type is set, can't allocate mempools");
1114		return -EINVAL;
1115	}
1116
1117	if (__table_type_bio_based(type))
1118		for (i = 0; i < t->num_targets; i++) {
1119			ti = t->targets + i;
1120			per_io_data_size = max(per_io_data_size, ti->per_io_data_size);
1121			min_pool_size = max(min_pool_size, ti->num_flush_bios);
1122		}
1123
1124	t->mempools = dm_alloc_md_mempools(md, type, t->integrity_supported,
1125					   per_io_data_size, min_pool_size);
1126	if (!t->mempools)
1127		return -ENOMEM;
1128
1129	return 0;
1130}
1131
1132void dm_table_free_md_mempools(struct dm_table *t)
1133{
1134	dm_free_md_mempools(t->mempools);
1135	t->mempools = NULL;
1136}
1137
1138struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t)
1139{
1140	return t->mempools;
1141}
1142
1143static int setup_indexes(struct dm_table *t)
1144{
1145	int i;
1146	unsigned int total = 0;
1147	sector_t *indexes;
1148
1149	/* allocate the space for *all* the indexes */
1150	for (i = t->depth - 2; i >= 0; i--) {
1151		t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
1152		total += t->counts[i];
1153	}
1154
1155	indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE);
1156	if (!indexes)
1157		return -ENOMEM;
1158
1159	/* set up internal nodes, bottom-up */
1160	for (i = t->depth - 2; i >= 0; i--) {
1161		t->index[i] = indexes;
1162		indexes += (KEYS_PER_NODE * t->counts[i]);
1163		setup_btree_index(i, t);
1164	}
1165
1166	return 0;
1167}
1168
1169/*
1170 * Builds the btree to index the map.
1171 */
1172static int dm_table_build_index(struct dm_table *t)
1173{
1174	int r = 0;
1175	unsigned int leaf_nodes;
1176
1177	/* how many indexes will the btree have ? */
1178	leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
1179	t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
1180
1181	/* leaf layer has already been set up */
1182	t->counts[t->depth - 1] = leaf_nodes;
1183	t->index[t->depth - 1] = t->highs;
1184
1185	if (t->depth >= 2)
1186		r = setup_indexes(t);
1187
1188	return r;
1189}
1190
1191static bool integrity_profile_exists(struct gendisk *disk)
1192{
1193	return !!blk_get_integrity(disk);
1194}
1195
1196/*
1197 * Get a disk whose integrity profile reflects the table's profile.
1198 * Returns NULL if integrity support was inconsistent or unavailable.
1199 */
1200static struct gendisk * dm_table_get_integrity_disk(struct dm_table *t)
1201{
1202	struct list_head *devices = dm_table_get_devices(t);
1203	struct dm_dev_internal *dd = NULL;
1204	struct gendisk *prev_disk = NULL, *template_disk = NULL;
1205	unsigned i;
1206
1207	for (i = 0; i < dm_table_get_num_targets(t); i++) {
1208		struct dm_target *ti = dm_table_get_target(t, i);
1209		if (!dm_target_passes_integrity(ti->type))
1210			goto no_integrity;
1211	}
1212
1213	list_for_each_entry(dd, devices, list) {
1214		template_disk = dd->dm_dev->bdev->bd_disk;
1215		if (!integrity_profile_exists(template_disk))
1216			goto no_integrity;
1217		else if (prev_disk &&
1218			 blk_integrity_compare(prev_disk, template_disk) < 0)
1219			goto no_integrity;
1220		prev_disk = template_disk;
1221	}
1222
1223	return template_disk;
1224
1225no_integrity:
1226	if (prev_disk)
1227		DMWARN("%s: integrity not set: %s and %s profile mismatch",
1228		       dm_device_name(t->md),
1229		       prev_disk->disk_name,
1230		       template_disk->disk_name);
1231	return NULL;
1232}
1233
1234/*
1235 * Register the mapped device for blk_integrity support if the
1236 * underlying devices have an integrity profile.  But all devices may
1237 * not have matching profiles (checking all devices isn't reliable
1238 * during table load because this table may use other DM device(s) which
1239 * must be resumed before they will have an initialized integity
1240 * profile).  Consequently, stacked DM devices force a 2 stage integrity
1241 * profile validation: First pass during table load, final pass during
1242 * resume.
1243 */
1244static int dm_table_register_integrity(struct dm_table *t)
1245{
1246	struct mapped_device *md = t->md;
1247	struct gendisk *template_disk = NULL;
1248
1249	/* If target handles integrity itself do not register it here. */
1250	if (t->integrity_added)
1251		return 0;
1252
1253	template_disk = dm_table_get_integrity_disk(t);
1254	if (!template_disk)
1255		return 0;
1256
1257	if (!integrity_profile_exists(dm_disk(md))) {
1258		t->integrity_supported = true;
1259		/*
1260		 * Register integrity profile during table load; we can do
1261		 * this because the final profile must match during resume.
1262		 */
1263		blk_integrity_register(dm_disk(md),
1264				       blk_get_integrity(template_disk));
1265		return 0;
1266	}
1267
1268	/*
1269	 * If DM device already has an initialized integrity
1270	 * profile the new profile should not conflict.
1271	 */
1272	if (blk_integrity_compare(dm_disk(md), template_disk) < 0) {
1273		DMWARN("%s: conflict with existing integrity profile: "
1274		       "%s profile mismatch",
1275		       dm_device_name(t->md),
1276		       template_disk->disk_name);
1277		return 1;
1278	}
1279
1280	/* Preserve existing integrity profile */
1281	t->integrity_supported = true;
1282	return 0;
1283}
1284
1285/*
1286 * Prepares the table for use by building the indices,
1287 * setting the type, and allocating mempools.
1288 */
1289int dm_table_complete(struct dm_table *t)
1290{
1291	int r;
1292
1293	r = dm_table_determine_type(t);
1294	if (r) {
1295		DMERR("unable to determine table type");
1296		return r;
1297	}
1298
1299	r = dm_table_build_index(t);
1300	if (r) {
1301		DMERR("unable to build btrees");
1302		return r;
1303	}
1304
1305	r = dm_table_register_integrity(t);
1306	if (r) {
1307		DMERR("could not register integrity profile.");
1308		return r;
1309	}
1310
1311	r = dm_table_alloc_md_mempools(t, t->md);
1312	if (r)
1313		DMERR("unable to allocate mempools");
1314
1315	return r;
1316}
1317
1318static DEFINE_MUTEX(_event_lock);
1319void dm_table_event_callback(struct dm_table *t,
1320			     void (*fn)(void *), void *context)
1321{
1322	mutex_lock(&_event_lock);
1323	t->event_fn = fn;
1324	t->event_context = context;
1325	mutex_unlock(&_event_lock);
1326}
1327
1328void dm_table_event(struct dm_table *t)
1329{
1330	/*
1331	 * You can no longer call dm_table_event() from interrupt
1332	 * context, use a bottom half instead.
1333	 */
1334	BUG_ON(in_interrupt());
1335
1336	mutex_lock(&_event_lock);
1337	if (t->event_fn)
1338		t->event_fn(t->event_context);
1339	mutex_unlock(&_event_lock);
1340}
1341EXPORT_SYMBOL(dm_table_event);
1342
1343inline sector_t dm_table_get_size(struct dm_table *t)
1344{
1345	return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1346}
1347EXPORT_SYMBOL(dm_table_get_size);
1348
1349struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index)
1350{
1351	if (index >= t->num_targets)
1352		return NULL;
1353
1354	return t->targets + index;
1355}
1356
1357/*
1358 * Search the btree for the correct target.
1359 *
1360 * Caller should check returned pointer for NULL
1361 * to trap I/O beyond end of device.
1362 */
1363struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1364{
1365	unsigned int l, n = 0, k = 0;
1366	sector_t *node;
1367
1368	if (unlikely(sector >= dm_table_get_size(t)))
1369		return NULL;
1370
1371	for (l = 0; l < t->depth; l++) {
1372		n = get_child(n, k);
1373		node = get_node(t, l, n);
1374
1375		for (k = 0; k < KEYS_PER_NODE; k++)
1376			if (node[k] >= sector)
1377				break;
1378	}
1379
1380	return &t->targets[(KEYS_PER_NODE * n) + k];
1381}
1382
1383static int count_device(struct dm_target *ti, struct dm_dev *dev,
1384			sector_t start, sector_t len, void *data)
1385{
1386	unsigned *num_devices = data;
1387
1388	(*num_devices)++;
1389
1390	return 0;
1391}
1392
1393/*
1394 * Check whether a table has no data devices attached using each
1395 * target's iterate_devices method.
1396 * Returns false if the result is unknown because a target doesn't
1397 * support iterate_devices.
1398 */
1399bool dm_table_has_no_data_devices(struct dm_table *table)
1400{
1401	struct dm_target *ti;
1402	unsigned i, num_devices;
1403
1404	for (i = 0; i < dm_table_get_num_targets(table); i++) {
1405		ti = dm_table_get_target(table, i);
1406
1407		if (!ti->type->iterate_devices)
1408			return false;
1409
1410		num_devices = 0;
1411		ti->type->iterate_devices(ti, count_device, &num_devices);
1412		if (num_devices)
1413			return false;
1414	}
1415
1416	return true;
1417}
1418
1419static int device_is_zoned_model(struct dm_target *ti, struct dm_dev *dev,
1420				 sector_t start, sector_t len, void *data)
1421{
1422	struct request_queue *q = bdev_get_queue(dev->bdev);
1423	enum blk_zoned_model *zoned_model = data;
1424
1425	return q && blk_queue_zoned_model(q) == *zoned_model;
1426}
1427
1428static bool dm_table_supports_zoned_model(struct dm_table *t,
1429					  enum blk_zoned_model zoned_model)
1430{
1431	struct dm_target *ti;
1432	unsigned i;
1433
1434	for (i = 0; i < dm_table_get_num_targets(t); i++) {
1435		ti = dm_table_get_target(t, i);
1436
1437		if (zoned_model == BLK_ZONED_HM &&
1438		    !dm_target_supports_zoned_hm(ti->type))
1439			return false;
1440
1441		if (!ti->type->iterate_devices ||
1442		    !ti->type->iterate_devices(ti, device_is_zoned_model, &zoned_model))
1443			return false;
1444	}
1445
1446	return true;
1447}
1448
1449static int device_matches_zone_sectors(struct dm_target *ti, struct dm_dev *dev,
1450				       sector_t start, sector_t len, void *data)
1451{
1452	struct request_queue *q = bdev_get_queue(dev->bdev);
1453	unsigned int *zone_sectors = data;
1454
1455	return q && blk_queue_zone_sectors(q) == *zone_sectors;
1456}
1457
1458static bool dm_table_matches_zone_sectors(struct dm_table *t,
1459					  unsigned int zone_sectors)
1460{
1461	struct dm_target *ti;
1462	unsigned i;
1463
1464	for (i = 0; i < dm_table_get_num_targets(t); i++) {
1465		ti = dm_table_get_target(t, i);
1466
1467		if (!ti->type->iterate_devices ||
1468		    !ti->type->iterate_devices(ti, device_matches_zone_sectors, &zone_sectors))
1469			return false;
1470	}
1471
1472	return true;
1473}
1474
1475static int validate_hardware_zoned_model(struct dm_table *table,
1476					 enum blk_zoned_model zoned_model,
1477					 unsigned int zone_sectors)
1478{
1479	if (zoned_model == BLK_ZONED_NONE)
1480		return 0;
1481
1482	if (!dm_table_supports_zoned_model(table, zoned_model)) {
1483		DMERR("%s: zoned model is not consistent across all devices",
1484		      dm_device_name(table->md));
1485		return -EINVAL;
1486	}
1487
1488	/* Check zone size validity and compatibility */
1489	if (!zone_sectors || !is_power_of_2(zone_sectors))
1490		return -EINVAL;
1491
1492	if (!dm_table_matches_zone_sectors(table, zone_sectors)) {
1493		DMERR("%s: zone sectors is not consistent across all devices",
1494		      dm_device_name(table->md));
1495		return -EINVAL;
1496	}
1497
1498	return 0;
1499}
1500
1501/*
1502 * Establish the new table's queue_limits and validate them.
1503 */
1504int dm_calculate_queue_limits(struct dm_table *table,
1505			      struct queue_limits *limits)
1506{
1507	struct dm_target *ti;
1508	struct queue_limits ti_limits;
1509	unsigned i;
1510	enum blk_zoned_model zoned_model = BLK_ZONED_NONE;
1511	unsigned int zone_sectors = 0;
1512
1513	blk_set_stacking_limits(limits);
1514
1515	for (i = 0; i < dm_table_get_num_targets(table); i++) {
1516		blk_set_stacking_limits(&ti_limits);
1517
1518		ti = dm_table_get_target(table, i);
1519
1520		if (!ti->type->iterate_devices)
1521			goto combine_limits;
1522
1523		/*
1524		 * Combine queue limits of all the devices this target uses.
1525		 */
1526		ti->type->iterate_devices(ti, dm_set_device_limits,
1527					  &ti_limits);
1528
1529		if (zoned_model == BLK_ZONED_NONE && ti_limits.zoned != BLK_ZONED_NONE) {
1530			/*
1531			 * After stacking all limits, validate all devices
1532			 * in table support this zoned model and zone sectors.
1533			 */
1534			zoned_model = ti_limits.zoned;
1535			zone_sectors = ti_limits.chunk_sectors;
1536		}
1537
1538		/* Set I/O hints portion of queue limits */
1539		if (ti->type->io_hints)
1540			ti->type->io_hints(ti, &ti_limits);
1541
1542		/*
1543		 * Check each device area is consistent with the target's
1544		 * overall queue limits.
1545		 */
1546		if (ti->type->iterate_devices(ti, device_area_is_invalid,
1547					      &ti_limits))
1548			return -EINVAL;
1549
1550combine_limits:
1551		/*
1552		 * Merge this target's queue limits into the overall limits
1553		 * for the table.
1554		 */
1555		if (blk_stack_limits(limits, &ti_limits, 0) < 0)
1556			DMWARN("%s: adding target device "
1557			       "(start sect %llu len %llu) "
1558			       "caused an alignment inconsistency",
1559			       dm_device_name(table->md),
1560			       (unsigned long long) ti->begin,
1561			       (unsigned long long) ti->len);
1562
1563		/*
1564		 * FIXME: this should likely be moved to blk_stack_limits(), would
1565		 * also eliminate limits->zoned stacking hack in dm_set_device_limits()
1566		 */
1567		if (limits->zoned == BLK_ZONED_NONE && ti_limits.zoned != BLK_ZONED_NONE) {
1568			/*
1569			 * By default, the stacked limits zoned model is set to
1570			 * BLK_ZONED_NONE in blk_set_stacking_limits(). Update
1571			 * this model using the first target model reported
1572			 * that is not BLK_ZONED_NONE. This will be either the
1573			 * first target device zoned model or the model reported
1574			 * by the target .io_hints.
1575			 */
1576			limits->zoned = ti_limits.zoned;
1577		}
1578	}
1579
1580	/*
1581	 * Verify that the zoned model and zone sectors, as determined before
1582	 * any .io_hints override, are the same across all devices in the table.
1583	 * - this is especially relevant if .io_hints is emulating a disk-managed
1584	 *   zoned model (aka BLK_ZONED_NONE) on host-managed zoned block devices.
1585	 * BUT...
1586	 */
1587	if (limits->zoned != BLK_ZONED_NONE) {
1588		/*
1589		 * ...IF the above limits stacking determined a zoned model
1590		 * validate that all of the table's devices conform to it.
1591		 */
1592		zoned_model = limits->zoned;
1593		zone_sectors = limits->chunk_sectors;
1594	}
1595	if (validate_hardware_zoned_model(table, zoned_model, zone_sectors))
1596		return -EINVAL;
1597
1598	return validate_hardware_logical_block_alignment(table, limits);
1599}
1600
1601/*
1602 * Verify that all devices have an integrity profile that matches the
1603 * DM device's registered integrity profile.  If the profiles don't
1604 * match then unregister the DM device's integrity profile.
1605 */
1606static void dm_table_verify_integrity(struct dm_table *t)
1607{
1608	struct gendisk *template_disk = NULL;
1609
1610	if (t->integrity_added)
1611		return;
1612
1613	if (t->integrity_supported) {
1614		/*
1615		 * Verify that the original integrity profile
1616		 * matches all the devices in this table.
1617		 */
1618		template_disk = dm_table_get_integrity_disk(t);
1619		if (template_disk &&
1620		    blk_integrity_compare(dm_disk(t->md), template_disk) >= 0)
1621			return;
1622	}
1623
1624	if (integrity_profile_exists(dm_disk(t->md))) {
1625		DMWARN("%s: unable to establish an integrity profile",
1626		       dm_device_name(t->md));
1627		blk_integrity_unregister(dm_disk(t->md));
1628	}
1629}
1630
1631static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
1632				sector_t start, sector_t len, void *data)
1633{
1634	unsigned long flush = (unsigned long) data;
1635	struct request_queue *q = bdev_get_queue(dev->bdev);
1636
1637	return q && (q->queue_flags & flush);
1638}
1639
1640static bool dm_table_supports_flush(struct dm_table *t, unsigned long flush)
1641{
1642	struct dm_target *ti;
1643	unsigned i;
1644
1645	/*
1646	 * Require at least one underlying device to support flushes.
1647	 * t->devices includes internal dm devices such as mirror logs
1648	 * so we need to use iterate_devices here, which targets
1649	 * supporting flushes must provide.
1650	 */
1651	for (i = 0; i < dm_table_get_num_targets(t); i++) {
1652		ti = dm_table_get_target(t, i);
1653
1654		if (!ti->num_flush_bios)
1655			continue;
1656
1657		if (ti->flush_supported)
1658			return true;
1659
1660		if (ti->type->iterate_devices &&
1661		    ti->type->iterate_devices(ti, device_flush_capable, (void *) flush))
1662			return true;
1663	}
1664
1665	return false;
1666}
1667
1668static int device_dax_write_cache_enabled(struct dm_target *ti,
1669					  struct dm_dev *dev, sector_t start,
1670					  sector_t len, void *data)
1671{
1672	struct dax_device *dax_dev = dev->dax_dev;
1673
1674	if (!dax_dev)
1675		return false;
1676
1677	if (dax_write_cache_enabled(dax_dev))
1678		return true;
1679	return false;
1680}
1681
1682static int dm_table_supports_dax_write_cache(struct dm_table *t)
1683{
1684	struct dm_target *ti;
1685	unsigned i;
1686
1687	for (i = 0; i < dm_table_get_num_targets(t); i++) {
1688		ti = dm_table_get_target(t, i);
1689
1690		if (ti->type->iterate_devices &&
1691		    ti->type->iterate_devices(ti,
1692				device_dax_write_cache_enabled, NULL))
1693			return true;
1694	}
1695
1696	return false;
1697}
1698
1699static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev,
1700			    sector_t start, sector_t len, void *data)
1701{
1702	struct request_queue *q = bdev_get_queue(dev->bdev);
1703
1704	return q && blk_queue_nonrot(q);
1705}
1706
1707static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
1708			     sector_t start, sector_t len, void *data)
1709{
1710	struct request_queue *q = bdev_get_queue(dev->bdev);
1711
1712	return q && !blk_queue_add_random(q);
1713}
1714
 
 
 
 
 
 
 
 
1715static bool dm_table_all_devices_attribute(struct dm_table *t,
1716					   iterate_devices_callout_fn func)
1717{
1718	struct dm_target *ti;
1719	unsigned i;
1720
1721	for (i = 0; i < dm_table_get_num_targets(t); i++) {
1722		ti = dm_table_get_target(t, i);
1723
1724		if (!ti->type->iterate_devices ||
1725		    !ti->type->iterate_devices(ti, func, NULL))
1726			return false;
1727	}
1728
1729	return true;
1730}
1731
1732static int device_no_partial_completion(struct dm_target *ti, struct dm_dev *dev,
1733					sector_t start, sector_t len, void *data)
1734{
1735	char b[BDEVNAME_SIZE];
1736
1737	/* For now, NVMe devices are the only devices of this class */
1738	return (strncmp(bdevname(dev->bdev, b), "nvme", 4) == 0);
1739}
1740
1741static bool dm_table_does_not_support_partial_completion(struct dm_table *t)
1742{
1743	return dm_table_all_devices_attribute(t, device_no_partial_completion);
1744}
1745
1746static int device_not_write_same_capable(struct dm_target *ti, struct dm_dev *dev,
1747					 sector_t start, sector_t len, void *data)
1748{
1749	struct request_queue *q = bdev_get_queue(dev->bdev);
1750
1751	return q && !q->limits.max_write_same_sectors;
1752}
1753
1754static bool dm_table_supports_write_same(struct dm_table *t)
1755{
1756	struct dm_target *ti;
1757	unsigned i;
1758
1759	for (i = 0; i < dm_table_get_num_targets(t); i++) {
1760		ti = dm_table_get_target(t, i);
1761
1762		if (!ti->num_write_same_bios)
1763			return false;
1764
1765		if (!ti->type->iterate_devices ||
1766		    ti->type->iterate_devices(ti, device_not_write_same_capable, NULL))
1767			return false;
1768	}
1769
1770	return true;
1771}
1772
1773static int device_not_write_zeroes_capable(struct dm_target *ti, struct dm_dev *dev,
1774					   sector_t start, sector_t len, void *data)
1775{
1776	struct request_queue *q = bdev_get_queue(dev->bdev);
1777
1778	return q && !q->limits.max_write_zeroes_sectors;
1779}
1780
1781static bool dm_table_supports_write_zeroes(struct dm_table *t)
1782{
1783	struct dm_target *ti;
1784	unsigned i = 0;
1785
1786	while (i < dm_table_get_num_targets(t)) {
1787		ti = dm_table_get_target(t, i++);
1788
1789		if (!ti->num_write_zeroes_bios)
1790			return false;
1791
1792		if (!ti->type->iterate_devices ||
1793		    ti->type->iterate_devices(ti, device_not_write_zeroes_capable, NULL))
1794			return false;
1795	}
1796
1797	return true;
1798}
1799
1800static int device_not_discard_capable(struct dm_target *ti, struct dm_dev *dev,
1801				      sector_t start, sector_t len, void *data)
1802{
1803	struct request_queue *q = bdev_get_queue(dev->bdev);
1804
1805	return q && !blk_queue_discard(q);
1806}
1807
1808static bool dm_table_supports_discards(struct dm_table *t)
1809{
1810	struct dm_target *ti;
1811	unsigned i;
1812
1813	for (i = 0; i < dm_table_get_num_targets(t); i++) {
1814		ti = dm_table_get_target(t, i);
1815
1816		if (!ti->num_discard_bios)
1817			return false;
1818
1819		/*
1820		 * Either the target provides discard support (as implied by setting
1821		 * 'discards_supported') or it relies on _all_ data devices having
1822		 * discard support.
1823		 */
1824		if (!ti->discards_supported &&
1825		    (!ti->type->iterate_devices ||
1826		     ti->type->iterate_devices(ti, device_not_discard_capable, NULL)))
1827			return false;
1828	}
1829
1830	return true;
1831}
1832
1833static int device_not_secure_erase_capable(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 && !blk_queue_secure_erase(q);
1840}
1841
1842static bool dm_table_supports_secure_erase(struct dm_table *t)
1843{
1844	struct dm_target *ti;
1845	unsigned int i;
1846
1847	for (i = 0; i < dm_table_get_num_targets(t); i++) {
1848		ti = dm_table_get_target(t, i);
1849
1850		if (!ti->num_secure_erase_bios)
1851			return false;
1852
1853		if (!ti->type->iterate_devices ||
1854		    ti->type->iterate_devices(ti, device_not_secure_erase_capable, NULL))
1855			return false;
1856	}
1857
1858	return true;
1859}
1860
1861static int device_requires_stable_pages(struct dm_target *ti,
1862					struct dm_dev *dev, sector_t start,
1863					sector_t len, void *data)
1864{
1865	struct request_queue *q = bdev_get_queue(dev->bdev);
1866
1867	return q && bdi_cap_stable_pages_required(q->backing_dev_info);
1868}
1869
1870/*
1871 * If any underlying device requires stable pages, a table must require
1872 * them as well.  Only targets that support iterate_devices are considered:
1873 * don't want error, zero, etc to require stable pages.
1874 */
1875static bool dm_table_requires_stable_pages(struct dm_table *t)
1876{
1877	struct dm_target *ti;
1878	unsigned i;
1879
1880	for (i = 0; i < dm_table_get_num_targets(t); i++) {
1881		ti = dm_table_get_target(t, i);
1882
1883		if (ti->type->iterate_devices &&
1884		    ti->type->iterate_devices(ti, device_requires_stable_pages, NULL))
1885			return true;
1886	}
1887
1888	return false;
1889}
1890
1891void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1892			       struct queue_limits *limits)
1893{
1894	bool wc = false, fua = false;
1895	int page_size = PAGE_SIZE;
1896
1897	/*
1898	 * Copy table's limits to the DM device's request_queue
1899	 */
1900	q->limits = *limits;
1901
1902	if (!dm_table_supports_discards(t)) {
1903		blk_queue_flag_clear(QUEUE_FLAG_DISCARD, q);
1904		/* Must also clear discard limits... */
1905		q->limits.max_discard_sectors = 0;
1906		q->limits.max_hw_discard_sectors = 0;
1907		q->limits.discard_granularity = 0;
1908		q->limits.discard_alignment = 0;
1909		q->limits.discard_misaligned = 0;
1910	} else
1911		blk_queue_flag_set(QUEUE_FLAG_DISCARD, q);
1912
1913	if (dm_table_supports_secure_erase(t))
1914		blk_queue_flag_set(QUEUE_FLAG_SECERASE, q);
1915
1916	if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_WC))) {
1917		wc = true;
1918		if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_FUA)))
1919			fua = true;
1920	}
1921	blk_queue_write_cache(q, wc, fua);
1922
1923	if (dm_table_supports_dax(t, device_supports_dax, &page_size)) {
1924		blk_queue_flag_set(QUEUE_FLAG_DAX, q);
1925		if (dm_table_supports_dax(t, device_dax_synchronous, NULL))
1926			set_dax_synchronous(t->md->dax_dev);
1927	}
1928	else
1929		blk_queue_flag_clear(QUEUE_FLAG_DAX, q);
1930
1931	if (dm_table_supports_dax_write_cache(t))
1932		dax_write_cache(t->md->dax_dev, true);
1933
1934	/* Ensure that all underlying devices are non-rotational. */
1935	if (dm_table_all_devices_attribute(t, device_is_nonrot))
1936		blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
1937	else
1938		blk_queue_flag_clear(QUEUE_FLAG_NONROT, q);
1939
1940	if (!dm_table_supports_write_same(t))
1941		q->limits.max_write_same_sectors = 0;
1942	if (!dm_table_supports_write_zeroes(t))
1943		q->limits.max_write_zeroes_sectors = 0;
1944
1945	dm_table_verify_integrity(t);
1946
1947	/*
1948	 * Some devices don't use blk_integrity but still want stable pages
1949	 * because they do their own checksumming.
1950	 */
1951	if (dm_table_requires_stable_pages(t))
1952		q->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES;
1953	else
1954		q->backing_dev_info->capabilities &= ~BDI_CAP_STABLE_WRITES;
 
 
1955
1956	/*
1957	 * Determine whether or not this queue's I/O timings contribute
1958	 * to the entropy pool, Only request-based targets use this.
1959	 * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
1960	 * have it set.
1961	 */
1962	if (blk_queue_add_random(q) && dm_table_all_devices_attribute(t, device_is_not_random))
1963		blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, q);
1964
1965	/*
1966	 * For a zoned target, the number of zones should be updated for the
1967	 * correct value to be exposed in sysfs queue/nr_zones. For a BIO based
1968	 * target, this is all that is needed. For a request based target, the
1969	 * queue zone bitmaps must also be updated.
1970	 * Use blk_revalidate_disk_zones() to handle this.
1971	 */
1972	if (blk_queue_is_zoned(q))
1973		blk_revalidate_disk_zones(t->md->disk);
1974
1975	/* Allow reads to exceed readahead limits */
1976	q->backing_dev_info->io_pages = limits->max_sectors >> (PAGE_SHIFT - 9);
1977}
1978
1979unsigned int dm_table_get_num_targets(struct dm_table *t)
1980{
1981	return t->num_targets;
1982}
1983
1984struct list_head *dm_table_get_devices(struct dm_table *t)
1985{
1986	return &t->devices;
1987}
1988
1989fmode_t dm_table_get_mode(struct dm_table *t)
1990{
1991	return t->mode;
1992}
1993EXPORT_SYMBOL(dm_table_get_mode);
1994
1995enum suspend_mode {
1996	PRESUSPEND,
1997	PRESUSPEND_UNDO,
1998	POSTSUSPEND,
1999};
2000
2001static void suspend_targets(struct dm_table *t, enum suspend_mode mode)
2002{
2003	int i = t->num_targets;
2004	struct dm_target *ti = t->targets;
2005
2006	lockdep_assert_held(&t->md->suspend_lock);
2007
2008	while (i--) {
2009		switch (mode) {
2010		case PRESUSPEND:
2011			if (ti->type->presuspend)
2012				ti->type->presuspend(ti);
2013			break;
2014		case PRESUSPEND_UNDO:
2015			if (ti->type->presuspend_undo)
2016				ti->type->presuspend_undo(ti);
2017			break;
2018		case POSTSUSPEND:
2019			if (ti->type->postsuspend)
2020				ti->type->postsuspend(ti);
2021			break;
2022		}
2023		ti++;
2024	}
2025}
2026
2027void dm_table_presuspend_targets(struct dm_table *t)
2028{
2029	if (!t)
2030		return;
2031
2032	suspend_targets(t, PRESUSPEND);
2033}
2034
2035void dm_table_presuspend_undo_targets(struct dm_table *t)
2036{
2037	if (!t)
2038		return;
2039
2040	suspend_targets(t, PRESUSPEND_UNDO);
2041}
2042
2043void dm_table_postsuspend_targets(struct dm_table *t)
2044{
2045	if (!t)
2046		return;
2047
2048	suspend_targets(t, POSTSUSPEND);
2049}
2050
2051int dm_table_resume_targets(struct dm_table *t)
2052{
2053	int i, r = 0;
2054
2055	lockdep_assert_held(&t->md->suspend_lock);
2056
2057	for (i = 0; i < t->num_targets; i++) {
2058		struct dm_target *ti = t->targets + i;
2059
2060		if (!ti->type->preresume)
2061			continue;
2062
2063		r = ti->type->preresume(ti);
2064		if (r) {
2065			DMERR("%s: %s: preresume failed, error = %d",
2066			      dm_device_name(t->md), ti->type->name, r);
2067			return r;
2068		}
2069	}
2070
2071	for (i = 0; i < t->num_targets; i++) {
2072		struct dm_target *ti = t->targets + i;
2073
2074		if (ti->type->resume)
2075			ti->type->resume(ti);
2076	}
2077
2078	return 0;
2079}
2080
2081void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb)
2082{
2083	list_add(&cb->list, &t->target_callbacks);
2084}
2085EXPORT_SYMBOL_GPL(dm_table_add_target_callbacks);
2086
2087int dm_table_any_congested(struct dm_table *t, int bdi_bits)
2088{
2089	struct dm_dev_internal *dd;
2090	struct list_head *devices = dm_table_get_devices(t);
2091	struct dm_target_callbacks *cb;
2092	int r = 0;
2093
2094	list_for_each_entry(dd, devices, list) {
2095		struct request_queue *q = bdev_get_queue(dd->dm_dev->bdev);
2096		char b[BDEVNAME_SIZE];
2097
2098		if (likely(q))
2099			r |= bdi_congested(q->backing_dev_info, bdi_bits);
2100		else
2101			DMWARN_LIMIT("%s: any_congested: nonexistent device %s",
2102				     dm_device_name(t->md),
2103				     bdevname(dd->dm_dev->bdev, b));
2104	}
2105
2106	list_for_each_entry(cb, &t->target_callbacks, list)
2107		if (cb->congested_fn)
2108			r |= cb->congested_fn(cb, bdi_bits);
2109
2110	return r;
2111}
2112
2113struct mapped_device *dm_table_get_md(struct dm_table *t)
2114{
2115	return t->md;
2116}
2117EXPORT_SYMBOL(dm_table_get_md);
2118
2119const char *dm_table_device_name(struct dm_table *t)
2120{
2121	return dm_device_name(t->md);
2122}
2123EXPORT_SYMBOL_GPL(dm_table_device_name);
2124
2125void dm_table_run_md_queue_async(struct dm_table *t)
2126{
2127	struct mapped_device *md;
2128	struct request_queue *queue;
 
2129
2130	if (!dm_table_request_based(t))
2131		return;
2132
2133	md = dm_table_get_md(t);
2134	queue = dm_get_md_queue(md);
2135	if (queue)
2136		blk_mq_run_hw_queues(queue, true);
 
 
 
 
 
 
 
2137}
2138EXPORT_SYMBOL(dm_table_run_md_queue_async);
2139