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v6.2
   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#include "dm-rq.h"
  10
  11#include <linux/module.h>
  12#include <linux/vmalloc.h>
  13#include <linux/blkdev.h>
  14#include <linux/blk-integrity.h>
  15#include <linux/namei.h>
  16#include <linux/ctype.h>
  17#include <linux/string.h>
  18#include <linux/slab.h>
  19#include <linux/interrupt.h>
  20#include <linux/mutex.h>
  21#include <linux/delay.h>
  22#include <linux/atomic.h>
  23#include <linux/blk-mq.h>
  24#include <linux/mount.h>
  25#include <linux/dax.h>
  26
  27#define DM_MSG_PREFIX "table"
  28
 
  29#define NODE_SIZE L1_CACHE_BYTES
  30#define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t))
  31#define CHILDREN_PER_NODE (KEYS_PER_NODE + 1)
  32
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  33/*
  34 * Similar to ceiling(log_size(n))
  35 */
  36static unsigned int int_log(unsigned int n, unsigned int base)
  37{
  38	int result = 0;
  39
  40	while (n > 1) {
  41		n = dm_div_up(n, base);
  42		result++;
  43	}
  44
  45	return result;
  46}
  47
  48/*
  49 * Calculate the index of the child node of the n'th node k'th key.
  50 */
  51static inline unsigned int get_child(unsigned int n, unsigned int k)
  52{
  53	return (n * CHILDREN_PER_NODE) + k;
  54}
  55
  56/*
  57 * Return the n'th node of level l from table t.
  58 */
  59static inline sector_t *get_node(struct dm_table *t,
  60				 unsigned int l, unsigned int n)
  61{
  62	return t->index[l] + (n * KEYS_PER_NODE);
  63}
  64
  65/*
  66 * Return the highest key that you could lookup from the n'th
  67 * node on level l of the btree.
  68 */
  69static sector_t high(struct dm_table *t, unsigned int l, unsigned int n)
  70{
  71	for (; l < t->depth - 1; l++)
  72		n = get_child(n, CHILDREN_PER_NODE - 1);
  73
  74	if (n >= t->counts[l])
  75		return (sector_t) - 1;
  76
  77	return get_node(t, l, n)[KEYS_PER_NODE - 1];
  78}
  79
  80/*
  81 * Fills in a level of the btree based on the highs of the level
  82 * below it.
  83 */
  84static int setup_btree_index(unsigned int l, struct dm_table *t)
  85{
  86	unsigned int n, k;
  87	sector_t *node;
  88
  89	for (n = 0U; n < t->counts[l]; n++) {
  90		node = get_node(t, l, n);
  91
  92		for (k = 0U; k < KEYS_PER_NODE; k++)
  93			node[k] = high(t, l + 1, get_child(n, k));
  94	}
  95
  96	return 0;
  97}
  98
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  99/*
 100 * highs, and targets are managed as dynamic arrays during a
 101 * table load.
 102 */
 103static int alloc_targets(struct dm_table *t, unsigned int num)
 104{
 105	sector_t *n_highs;
 106	struct dm_target *n_targets;
 107
 108	/*
 109	 * Allocate both the target array and offset array at once.
 
 
 110	 */
 111	n_highs = kvcalloc(num, sizeof(struct dm_target) + sizeof(sector_t),
 112			   GFP_KERNEL);
 113	if (!n_highs)
 114		return -ENOMEM;
 115
 116	n_targets = (struct dm_target *) (n_highs + num);
 117
 118	memset(n_highs, -1, sizeof(*n_highs) * num);
 119	kvfree(t->highs);
 120
 121	t->num_allocated = num;
 122	t->highs = n_highs;
 123	t->targets = n_targets;
 124
 125	return 0;
 126}
 127
 128int dm_table_create(struct dm_table **result, fmode_t mode,
 129		    unsigned num_targets, struct mapped_device *md)
 130{
 131	struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
 132
 133	if (!t)
 134		return -ENOMEM;
 135
 136	INIT_LIST_HEAD(&t->devices);
 
 137
 138	if (!num_targets)
 139		num_targets = KEYS_PER_NODE;
 140
 141	num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
 142
 143	if (!num_targets) {
 144		kfree(t);
 145		return -ENOMEM;
 146	}
 147
 148	if (alloc_targets(t, num_targets)) {
 149		kfree(t);
 150		return -ENOMEM;
 151	}
 152
 153	t->type = DM_TYPE_NONE;
 154	t->mode = mode;
 155	t->md = md;
 156	*result = t;
 157	return 0;
 158}
 159
 160static void free_devices(struct list_head *devices, struct mapped_device *md)
 161{
 162	struct list_head *tmp, *next;
 163
 164	list_for_each_safe(tmp, next, devices) {
 165		struct dm_dev_internal *dd =
 166		    list_entry(tmp, struct dm_dev_internal, list);
 167		DMWARN("%s: dm_table_destroy: dm_put_device call missing for %s",
 168		       dm_device_name(md), dd->dm_dev->name);
 169		dm_put_table_device(md, dd->dm_dev);
 170		kfree(dd);
 171	}
 172}
 173
 174static void dm_table_destroy_crypto_profile(struct dm_table *t);
 175
 176void dm_table_destroy(struct dm_table *t)
 177{
 
 
 178	if (!t)
 179		return;
 180
 181	/* free the indexes */
 182	if (t->depth >= 2)
 183		kvfree(t->index[t->depth - 2]);
 184
 185	/* free the targets */
 186	for (unsigned int i = 0; i < t->num_targets; i++) {
 187		struct dm_target *ti = dm_table_get_target(t, i);
 188
 189		if (ti->type->dtr)
 190			ti->type->dtr(ti);
 191
 192		dm_put_target_type(ti->type);
 193	}
 194
 195	kvfree(t->highs);
 196
 197	/* free the device list */
 198	free_devices(&t->devices, t->md);
 199
 200	dm_free_md_mempools(t->mempools);
 201
 202	dm_table_destroy_crypto_profile(t);
 203
 204	kfree(t);
 205}
 206
 207/*
 208 * See if we've already got a device in the list.
 209 */
 210static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
 211{
 212	struct dm_dev_internal *dd;
 213
 214	list_for_each_entry (dd, l, list)
 215		if (dd->dm_dev->bdev->bd_dev == dev)
 216			return dd;
 217
 218	return NULL;
 219}
 220
 221/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 222 * If possible, this checks an area of a destination device is invalid.
 223 */
 224static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
 225				  sector_t start, sector_t len, void *data)
 226{
 
 227	struct queue_limits *limits = data;
 228	struct block_device *bdev = dev->bdev;
 229	sector_t dev_size = bdev_nr_sectors(bdev);
 
 230	unsigned short logical_block_size_sectors =
 231		limits->logical_block_size >> SECTOR_SHIFT;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 232
 233	if (!dev_size)
 234		return 0;
 235
 236	if ((start >= dev_size) || (start + len > dev_size)) {
 237		DMERR("%s: %pg too small for target: "
 238		      "start=%llu, len=%llu, dev_size=%llu",
 239		      dm_device_name(ti->table->md), bdev,
 240		      (unsigned long long)start,
 241		      (unsigned long long)len,
 242		      (unsigned long long)dev_size);
 243		return 1;
 244	}
 245
 246	/*
 247	 * If the target is mapped to zoned block device(s), check
 248	 * that the zones are not partially mapped.
 249	 */
 250	if (bdev_is_zoned(bdev)) {
 251		unsigned int zone_sectors = bdev_zone_sectors(bdev);
 252
 253		if (start & (zone_sectors - 1)) {
 254			DMERR("%s: start=%llu not aligned to h/w zone size %u of %pg",
 255			      dm_device_name(ti->table->md),
 256			      (unsigned long long)start,
 257			      zone_sectors, bdev);
 258			return 1;
 259		}
 260
 261		/*
 262		 * Note: The last zone of a zoned block device may be smaller
 263		 * than other zones. So for a target mapping the end of a
 264		 * zoned block device with such a zone, len would not be zone
 265		 * aligned. We do not allow such last smaller zone to be part
 266		 * of the mapping here to ensure that mappings with multiple
 267		 * devices do not end up with a smaller zone in the middle of
 268		 * the sector range.
 269		 */
 270		if (len & (zone_sectors - 1)) {
 271			DMERR("%s: len=%llu not aligned to h/w zone size %u of %pg",
 272			      dm_device_name(ti->table->md),
 273			      (unsigned long long)len,
 274			      zone_sectors, bdev);
 275			return 1;
 276		}
 277	}
 278
 279	if (logical_block_size_sectors <= 1)
 280		return 0;
 281
 282	if (start & (logical_block_size_sectors - 1)) {
 283		DMERR("%s: start=%llu not aligned to h/w "
 284		      "logical block size %u of %pg",
 285		      dm_device_name(ti->table->md),
 286		      (unsigned long long)start,
 287		      limits->logical_block_size, bdev);
 288		return 1;
 289	}
 290
 291	if (len & (logical_block_size_sectors - 1)) {
 292		DMERR("%s: len=%llu not aligned to h/w "
 293		      "logical block size %u of %pg",
 294		      dm_device_name(ti->table->md),
 295		      (unsigned long long)len,
 296		      limits->logical_block_size, bdev);
 297		return 1;
 298	}
 299
 300	return 0;
 301}
 302
 303/*
 304 * This upgrades the mode on an already open dm_dev, being
 305 * careful to leave things as they were if we fail to reopen the
 306 * device and not to touch the existing bdev field in case
 307 * it is accessed concurrently.
 308 */
 309static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
 310			struct mapped_device *md)
 311{
 312	int r;
 313	struct dm_dev *old_dev, *new_dev;
 
 
 314
 315	old_dev = dd->dm_dev;
 
 316
 317	r = dm_get_table_device(md, dd->dm_dev->bdev->bd_dev,
 318				dd->dm_dev->mode | new_mode, &new_dev);
 319	if (r)
 320		return r;
 321
 322	dd->dm_dev = new_dev;
 323	dm_put_table_device(md, old_dev);
 324
 325	return 0;
 326}
 327
 328/*
 329 * Convert the path to a device
 330 */
 331dev_t dm_get_dev_t(const char *path)
 332{
 333	dev_t dev;
 334
 335	if (lookup_bdev(path, &dev))
 336		dev = name_to_dev_t(path);
 337	return dev;
 338}
 339EXPORT_SYMBOL_GPL(dm_get_dev_t);
 340
 341/*
 342 * Add a device to the list, or just increment the usage count if
 343 * it's already present.
 344 */
 345int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
 346		  struct dm_dev **result)
 347{
 348	int r;
 349	dev_t dev;
 350	unsigned int major, minor;
 351	char dummy;
 352	struct dm_dev_internal *dd;
 
 353	struct dm_table *t = ti->table;
 
 354
 355	BUG_ON(!t);
 356
 357	if (sscanf(path, "%u:%u%c", &major, &minor, &dummy) == 2) {
 358		/* Extract the major/minor numbers */
 359		dev = MKDEV(major, minor);
 360		if (MAJOR(dev) != major || MINOR(dev) != minor)
 361			return -EOVERFLOW;
 362	} else {
 363		dev = dm_get_dev_t(path);
 364		if (!dev)
 365			return -ENODEV;
 
 
 
 
 366	}
 367
 368	dd = find_device(&t->devices, dev);
 369	if (!dd) {
 370		dd = kmalloc(sizeof(*dd), GFP_KERNEL);
 371		if (!dd)
 372			return -ENOMEM;
 373
 374		if ((r = dm_get_table_device(t->md, dev, mode, &dd->dm_dev))) {
 
 
 
 375			kfree(dd);
 376			return r;
 377		}
 378
 379		refcount_set(&dd->count, 1);
 
 
 380		list_add(&dd->list, &t->devices);
 381		goto out;
 382
 383	} else if (dd->dm_dev->mode != (mode | dd->dm_dev->mode)) {
 384		r = upgrade_mode(dd, mode, t->md);
 385		if (r)
 386			return r;
 387	}
 388	refcount_inc(&dd->count);
 389out:
 390	*result = dd->dm_dev;
 391	return 0;
 392}
 393EXPORT_SYMBOL(dm_get_device);
 394
 395static int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
 396				sector_t start, sector_t len, void *data)
 397{
 398	struct queue_limits *limits = data;
 399	struct block_device *bdev = dev->bdev;
 400	struct request_queue *q = bdev_get_queue(bdev);
 
 401
 402	if (unlikely(!q)) {
 403		DMWARN("%s: Cannot set limits for nonexistent device %pg",
 404		       dm_device_name(ti->table->md), bdev);
 405		return 0;
 406	}
 407
 408	if (blk_stack_limits(limits, &q->limits,
 409			get_start_sect(bdev) + start) < 0)
 410		DMWARN("%s: adding target device %pg caused an alignment inconsistency: "
 411		       "physical_block_size=%u, logical_block_size=%u, "
 412		       "alignment_offset=%u, start=%llu",
 413		       dm_device_name(ti->table->md), bdev,
 414		       q->limits.physical_block_size,
 415		       q->limits.logical_block_size,
 416		       q->limits.alignment_offset,
 417		       (unsigned long long) start << SECTOR_SHIFT);
 
 
 
 
 
 
 
 
 
 418	return 0;
 419}
 
 420
 421/*
 422 * Decrement a device's use count and remove it if necessary.
 423 */
 424void dm_put_device(struct dm_target *ti, struct dm_dev *d)
 425{
 426	int found = 0;
 427	struct list_head *devices = &ti->table->devices;
 428	struct dm_dev_internal *dd;
 429
 430	list_for_each_entry(dd, devices, list) {
 431		if (dd->dm_dev == d) {
 432			found = 1;
 433			break;
 434		}
 435	}
 436	if (!found) {
 437		DMERR("%s: device %s not in table devices list",
 438		      dm_device_name(ti->table->md), d->name);
 439		return;
 440	}
 441	if (refcount_dec_and_test(&dd->count)) {
 442		dm_put_table_device(ti->table->md, d);
 443		list_del(&dd->list);
 444		kfree(dd);
 445	}
 446}
 447EXPORT_SYMBOL(dm_put_device);
 448
 449/*
 450 * Checks to see if the target joins onto the end of the table.
 451 */
 452static int adjoin(struct dm_table *t, struct dm_target *ti)
 453{
 454	struct dm_target *prev;
 455
 456	if (!t->num_targets)
 457		return !ti->begin;
 458
 459	prev = &t->targets[t->num_targets - 1];
 460	return (ti->begin == (prev->begin + prev->len));
 461}
 462
 463/*
 464 * Used to dynamically allocate the arg array.
 465 *
 466 * We do first allocation with GFP_NOIO because dm-mpath and dm-thin must
 467 * process messages even if some device is suspended. These messages have a
 468 * small fixed number of arguments.
 469 *
 470 * On the other hand, dm-switch needs to process bulk data using messages and
 471 * excessive use of GFP_NOIO could cause trouble.
 472 */
 473static char **realloc_argv(unsigned *size, char **old_argv)
 474{
 475	char **argv;
 476	unsigned new_size;
 477	gfp_t gfp;
 478
 479	if (*size) {
 480		new_size = *size * 2;
 481		gfp = GFP_KERNEL;
 482	} else {
 483		new_size = 8;
 484		gfp = GFP_NOIO;
 485	}
 486	argv = kmalloc_array(new_size, sizeof(*argv), gfp);
 487	if (argv && old_argv) {
 488		memcpy(argv, old_argv, *size * sizeof(*argv));
 489		*size = new_size;
 490	}
 491
 492	kfree(old_argv);
 493	return argv;
 494}
 495
 496/*
 497 * Destructively splits up the argument list to pass to ctr.
 498 */
 499int dm_split_args(int *argc, char ***argvp, char *input)
 500{
 501	char *start, *end = input, *out, **argv = NULL;
 502	unsigned array_size = 0;
 503
 504	*argc = 0;
 505
 506	if (!input) {
 507		*argvp = NULL;
 508		return 0;
 509	}
 510
 511	argv = realloc_argv(&array_size, argv);
 512	if (!argv)
 513		return -ENOMEM;
 514
 515	while (1) {
 516		/* Skip whitespace */
 517		start = skip_spaces(end);
 518
 519		if (!*start)
 520			break;	/* success, we hit the end */
 521
 522		/* 'out' is used to remove any back-quotes */
 523		end = out = start;
 524		while (*end) {
 525			/* Everything apart from '\0' can be quoted */
 526			if (*end == '\\' && *(end + 1)) {
 527				*out++ = *(end + 1);
 528				end += 2;
 529				continue;
 530			}
 531
 532			if (isspace(*end))
 533				break;	/* end of token */
 534
 535			*out++ = *end++;
 536		}
 537
 538		/* have we already filled the array ? */
 539		if ((*argc + 1) > array_size) {
 540			argv = realloc_argv(&array_size, argv);
 541			if (!argv)
 542				return -ENOMEM;
 543		}
 544
 545		/* we know this is whitespace */
 546		if (*end)
 547			end++;
 548
 549		/* terminate the string and put it in the array */
 550		*out = '\0';
 551		argv[*argc] = start;
 552		(*argc)++;
 553	}
 554
 555	*argvp = argv;
 556	return 0;
 557}
 558
 559/*
 560 * Impose necessary and sufficient conditions on a devices's table such
 561 * that any incoming bio which respects its logical_block_size can be
 562 * processed successfully.  If it falls across the boundary between
 563 * two or more targets, the size of each piece it gets split into must
 564 * be compatible with the logical_block_size of the target processing it.
 565 */
 566static int validate_hardware_logical_block_alignment(struct dm_table *t,
 567						     struct queue_limits *limits)
 568{
 569	/*
 570	 * This function uses arithmetic modulo the logical_block_size
 571	 * (in units of 512-byte sectors).
 572	 */
 573	unsigned short device_logical_block_size_sects =
 574		limits->logical_block_size >> SECTOR_SHIFT;
 575
 576	/*
 577	 * Offset of the start of the next table entry, mod logical_block_size.
 578	 */
 579	unsigned short next_target_start = 0;
 580
 581	/*
 582	 * Given an aligned bio that extends beyond the end of a
 583	 * target, how many sectors must the next target handle?
 584	 */
 585	unsigned short remaining = 0;
 586
 587	struct dm_target *ti;
 588	struct queue_limits ti_limits;
 589	unsigned int i;
 590
 591	/*
 592	 * Check each entry in the table in turn.
 593	 */
 594	for (i = 0; i < t->num_targets; i++) {
 595		ti = dm_table_get_target(t, i);
 596
 597		blk_set_stacking_limits(&ti_limits);
 598
 599		/* combine all target devices' limits */
 600		if (ti->type->iterate_devices)
 601			ti->type->iterate_devices(ti, dm_set_device_limits,
 602						  &ti_limits);
 603
 604		/*
 605		 * If the remaining sectors fall entirely within this
 606		 * table entry are they compatible with its logical_block_size?
 607		 */
 608		if (remaining < ti->len &&
 609		    remaining & ((ti_limits.logical_block_size >>
 610				  SECTOR_SHIFT) - 1))
 611			break;	/* Error */
 612
 613		next_target_start =
 614		    (unsigned short) ((next_target_start + ti->len) &
 615				      (device_logical_block_size_sects - 1));
 616		remaining = next_target_start ?
 617		    device_logical_block_size_sects - next_target_start : 0;
 618	}
 619
 620	if (remaining) {
 621		DMERR("%s: table line %u (start sect %llu len %llu) "
 622		      "not aligned to h/w logical block size %u",
 623		      dm_device_name(t->md), i,
 624		      (unsigned long long) ti->begin,
 625		      (unsigned long long) ti->len,
 626		      limits->logical_block_size);
 627		return -EINVAL;
 628	}
 629
 630	return 0;
 631}
 632
 633int dm_table_add_target(struct dm_table *t, const char *type,
 634			sector_t start, sector_t len, char *params)
 635{
 636	int r = -EINVAL, argc;
 637	char **argv;
 638	struct dm_target *ti;
 639
 640	if (t->singleton) {
 641		DMERR("%s: target type %s must appear alone in table",
 642		      dm_device_name(t->md), t->targets->type->name);
 643		return -EINVAL;
 644	}
 645
 646	BUG_ON(t->num_targets >= t->num_allocated);
 647
 648	ti = t->targets + t->num_targets;
 649	memset(ti, 0, sizeof(*ti));
 650
 651	if (!len) {
 652		DMERR("%s: zero-length target", dm_device_name(t->md));
 653		return -EINVAL;
 654	}
 655
 656	ti->type = dm_get_target_type(type);
 657	if (!ti->type) {
 658		DMERR("%s: %s: unknown target type", dm_device_name(t->md), type);
 
 659		return -EINVAL;
 660	}
 661
 662	if (dm_target_needs_singleton(ti->type)) {
 663		if (t->num_targets) {
 664			ti->error = "singleton target type must appear alone in table";
 665			goto bad;
 
 666		}
 667		t->singleton = true;
 668	}
 669
 670	if (dm_target_always_writeable(ti->type) && !(t->mode & FMODE_WRITE)) {
 671		ti->error = "target type may not be included in a read-only table";
 672		goto bad;
 
 673	}
 674
 675	if (t->immutable_target_type) {
 676		if (t->immutable_target_type != ti->type) {
 677			ti->error = "immutable target type cannot be mixed with other target types";
 678			goto bad;
 
 679		}
 680	} else if (dm_target_is_immutable(ti->type)) {
 681		if (t->num_targets) {
 682			ti->error = "immutable target type cannot be mixed with other target types";
 683			goto bad;
 
 684		}
 685		t->immutable_target_type = ti->type;
 686	}
 687
 688	if (dm_target_has_integrity(ti->type))
 689		t->integrity_added = 1;
 690
 691	ti->table = t;
 692	ti->begin = start;
 693	ti->len = len;
 694	ti->error = "Unknown error";
 695
 696	/*
 697	 * Does this target adjoin the previous one ?
 698	 */
 699	if (!adjoin(t, ti)) {
 700		ti->error = "Gap in table";
 
 701		goto bad;
 702	}
 703
 704	r = dm_split_args(&argc, &argv, params);
 705	if (r) {
 706		ti->error = "couldn't split parameters";
 707		goto bad;
 708	}
 709
 710	r = ti->type->ctr(ti, argc, argv);
 711	kfree(argv);
 712	if (r)
 713		goto bad;
 714
 715	t->highs[t->num_targets++] = ti->begin + ti->len - 1;
 716
 717	if (!ti->num_discard_bios && ti->discards_supported)
 718		DMWARN("%s: %s: ignoring discards_supported because num_discard_bios is zero.",
 719		       dm_device_name(t->md), type);
 720
 721	if (ti->limit_swap_bios && !static_key_enabled(&swap_bios_enabled.key))
 722		static_branch_enable(&swap_bios_enabled);
 723
 724	return 0;
 725
 726 bad:
 727	DMERR("%s: %s: %s (%pe)", dm_device_name(t->md), type, ti->error, ERR_PTR(r));
 728	dm_put_target_type(ti->type);
 729	return r;
 730}
 731
 732/*
 733 * Target argument parsing helpers.
 734 */
 735static int validate_next_arg(const struct dm_arg *arg,
 736			     struct dm_arg_set *arg_set,
 737			     unsigned *value, char **error, unsigned grouped)
 738{
 739	const char *arg_str = dm_shift_arg(arg_set);
 740	char dummy;
 741
 742	if (!arg_str ||
 743	    (sscanf(arg_str, "%u%c", value, &dummy) != 1) ||
 744	    (*value < arg->min) ||
 745	    (*value > arg->max) ||
 746	    (grouped && arg_set->argc < *value)) {
 747		*error = arg->error;
 748		return -EINVAL;
 749	}
 750
 751	return 0;
 752}
 753
 754int dm_read_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
 755		unsigned *value, char **error)
 756{
 757	return validate_next_arg(arg, arg_set, value, error, 0);
 758}
 759EXPORT_SYMBOL(dm_read_arg);
 760
 761int dm_read_arg_group(const struct dm_arg *arg, struct dm_arg_set *arg_set,
 762		      unsigned *value, char **error)
 763{
 764	return validate_next_arg(arg, arg_set, value, error, 1);
 765}
 766EXPORT_SYMBOL(dm_read_arg_group);
 767
 768const char *dm_shift_arg(struct dm_arg_set *as)
 769{
 770	char *r;
 771
 772	if (as->argc) {
 773		as->argc--;
 774		r = *as->argv;
 775		as->argv++;
 776		return r;
 777	}
 778
 779	return NULL;
 780}
 781EXPORT_SYMBOL(dm_shift_arg);
 782
 783void dm_consume_args(struct dm_arg_set *as, unsigned num_args)
 784{
 785	BUG_ON(as->argc < num_args);
 786	as->argc -= num_args;
 787	as->argv += num_args;
 788}
 789EXPORT_SYMBOL(dm_consume_args);
 790
 791static bool __table_type_bio_based(enum dm_queue_mode table_type)
 792{
 793	return (table_type == DM_TYPE_BIO_BASED ||
 794		table_type == DM_TYPE_DAX_BIO_BASED);
 795}
 796
 797static bool __table_type_request_based(enum dm_queue_mode table_type)
 798{
 799	return table_type == DM_TYPE_REQUEST_BASED;
 800}
 801
 802void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type)
 803{
 804	t->type = type;
 805}
 806EXPORT_SYMBOL_GPL(dm_table_set_type);
 807
 808/* validate the dax capability of the target device span */
 809static int device_not_dax_capable(struct dm_target *ti, struct dm_dev *dev,
 810			sector_t start, sector_t len, void *data)
 811{
 812	if (dev->dax_dev)
 813		return false;
 814
 815	DMDEBUG("%pg: error: dax unsupported by block device", dev->bdev);
 816	return true;
 817}
 818
 819/* Check devices support synchronous DAX */
 820static int device_not_dax_synchronous_capable(struct dm_target *ti, struct dm_dev *dev,
 821					      sector_t start, sector_t len, void *data)
 822{
 823	return !dev->dax_dev || !dax_synchronous(dev->dax_dev);
 824}
 825
 826static bool dm_table_supports_dax(struct dm_table *t,
 827				  iterate_devices_callout_fn iterate_fn)
 828{
 829	/* Ensure that all targets support DAX. */
 830	for (unsigned int i = 0; i < t->num_targets; i++) {
 831		struct dm_target *ti = dm_table_get_target(t, i);
 832
 833		if (!ti->type->direct_access)
 834			return false;
 835
 836		if (!ti->type->iterate_devices ||
 837		    ti->type->iterate_devices(ti, iterate_fn, NULL))
 838			return false;
 839	}
 840
 841	return true;
 842}
 843
 844static int device_is_rq_stackable(struct dm_target *ti, struct dm_dev *dev,
 845				  sector_t start, sector_t len, void *data)
 846{
 847	struct block_device *bdev = dev->bdev;
 848	struct request_queue *q = bdev_get_queue(bdev);
 849
 850	/* request-based cannot stack on partitions! */
 851	if (bdev_is_partition(bdev))
 852		return false;
 853
 854	return queue_is_mq(q);
 855}
 856
 857static int dm_table_determine_type(struct dm_table *t)
 858{
 
 859	unsigned bio_based = 0, request_based = 0, hybrid = 0;
 860	struct dm_target *ti;
 861	struct list_head *devices = dm_table_get_devices(t);
 862	enum dm_queue_mode live_md_type = dm_get_md_type(t->md);
 863
 864	if (t->type != DM_TYPE_NONE) {
 865		/* target already set the table's type */
 866		if (t->type == DM_TYPE_BIO_BASED) {
 867			/* possibly upgrade to a variant of bio-based */
 868			goto verify_bio_based;
 869		}
 870		BUG_ON(t->type == DM_TYPE_DAX_BIO_BASED);
 871		goto verify_rq_based;
 872	}
 873
 874	for (unsigned int i = 0; i < t->num_targets; i++) {
 875		ti = dm_table_get_target(t, i);
 876		if (dm_target_hybrid(ti))
 877			hybrid = 1;
 878		else if (dm_target_request_based(ti))
 879			request_based = 1;
 880		else
 881			bio_based = 1;
 882
 883		if (bio_based && request_based) {
 884			DMERR("Inconsistent table: different target types"
 885			      " can't be mixed up");
 886			return -EINVAL;
 887		}
 888	}
 889
 890	if (hybrid && !bio_based && !request_based) {
 891		/*
 892		 * The targets can work either way.
 893		 * Determine the type from the live device.
 894		 * Default to bio-based if device is new.
 895		 */
 896		if (__table_type_request_based(live_md_type))
 
 897			request_based = 1;
 898		else
 899			bio_based = 1;
 900	}
 901
 902	if (bio_based) {
 903verify_bio_based:
 904		/* We must use this table as bio-based */
 905		t->type = DM_TYPE_BIO_BASED;
 906		if (dm_table_supports_dax(t, device_not_dax_capable) ||
 907		    (list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED)) {
 908			t->type = DM_TYPE_DAX_BIO_BASED;
 909		}
 910		return 0;
 911	}
 912
 913	BUG_ON(!request_based); /* No targets in this table */
 914
 915	t->type = DM_TYPE_REQUEST_BASED;
 
 
 
 
 
 
 
 
 916
 917verify_rq_based:
 918	/*
 919	 * Request-based dm supports only tables that have a single target now.
 920	 * To support multiple targets, request splitting support is needed,
 921	 * and that needs lots of changes in the block-layer.
 922	 * (e.g. request completion process for partial completion.)
 923	 */
 924	if (t->num_targets > 1) {
 925		DMERR("request-based DM doesn't support multiple targets");
 926		return -EINVAL;
 927	}
 928
 929	if (list_empty(devices)) {
 930		int srcu_idx;
 931		struct dm_table *live_table = dm_get_live_table(t->md, &srcu_idx);
 932
 933		/* inherit live table's type */
 934		if (live_table)
 935			t->type = live_table->type;
 936		dm_put_live_table(t->md, srcu_idx);
 937		return 0;
 938	}
 939
 940	ti = dm_table_get_immutable_target(t);
 941	if (!ti) {
 942		DMERR("table load rejected: immutable target is required");
 943		return -EINVAL;
 944	} else if (ti->max_io_len) {
 945		DMERR("table load rejected: immutable target that splits IO is not supported");
 946		return -EINVAL;
 947	}
 948
 949	/* Non-request-stackable devices can't be used for request-based dm */
 950	if (!ti->type->iterate_devices ||
 951	    !ti->type->iterate_devices(ti, device_is_rq_stackable, NULL)) {
 952		DMERR("table load rejected: including non-request-stackable devices");
 953		return -EINVAL;
 954	}
 955
 956	return 0;
 957}
 958
 959enum dm_queue_mode dm_table_get_type(struct dm_table *t)
 960{
 961	return t->type;
 962}
 963
 964struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
 965{
 966	return t->immutable_target_type;
 967}
 968
 969struct dm_target *dm_table_get_immutable_target(struct dm_table *t)
 970{
 971	/* Immutable target is implicitly a singleton */
 972	if (t->num_targets > 1 ||
 973	    !dm_target_is_immutable(t->targets[0].type))
 974		return NULL;
 975
 976	return t->targets;
 977}
 978
 979struct dm_target *dm_table_get_wildcard_target(struct dm_table *t)
 980{
 981	for (unsigned int i = 0; i < t->num_targets; i++) {
 982		struct dm_target *ti = dm_table_get_target(t, i);
 
 
 983
 984		if (dm_target_is_wildcard(ti->type))
 985			return ti;
 
 986	}
 987
 988	return NULL;
 989}
 
 
 
 990
 991bool dm_table_bio_based(struct dm_table *t)
 992{
 993	return __table_type_bio_based(dm_table_get_type(t));
 
 
 994}
 995
 996bool dm_table_request_based(struct dm_table *t)
 997{
 998	return __table_type_request_based(dm_table_get_type(t));
 
 999}
1000
1001static bool dm_table_supports_poll(struct dm_table *t);
1002
1003static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device *md)
1004{
1005	enum dm_queue_mode type = dm_table_get_type(t);
1006	unsigned int per_io_data_size = 0, front_pad, io_front_pad;
1007	unsigned int min_pool_size = 0, pool_size;
1008	struct dm_md_mempools *pools;
1009
1010	if (unlikely(type == DM_TYPE_NONE)) {
1011		DMERR("no table type is set, can't allocate mempools");
1012		return -EINVAL;
1013	}
1014
1015	pools = kzalloc_node(sizeof(*pools), GFP_KERNEL, md->numa_node_id);
1016	if (!pools)
1017		return -ENOMEM;
1018
1019	if (type == DM_TYPE_REQUEST_BASED) {
1020		pool_size = dm_get_reserved_rq_based_ios();
1021		front_pad = offsetof(struct dm_rq_clone_bio_info, clone);
1022		goto init_bs;
1023	}
1024
1025	for (unsigned int i = 0; i < t->num_targets; i++) {
1026		struct dm_target *ti = dm_table_get_target(t, i);
1027
1028		per_io_data_size = max(per_io_data_size, ti->per_io_data_size);
1029		min_pool_size = max(min_pool_size, ti->num_flush_bios);
1030	}
1031	pool_size = max(dm_get_reserved_bio_based_ios(), min_pool_size);
1032	front_pad = roundup(per_io_data_size,
1033		__alignof__(struct dm_target_io)) + DM_TARGET_IO_BIO_OFFSET;
1034
1035	io_front_pad = roundup(per_io_data_size,
1036		__alignof__(struct dm_io)) + DM_IO_BIO_OFFSET;
1037	if (bioset_init(&pools->io_bs, pool_size, io_front_pad,
1038			dm_table_supports_poll(t) ? BIOSET_PERCPU_CACHE : 0))
1039		goto out_free_pools;
1040	if (t->integrity_supported &&
1041	    bioset_integrity_create(&pools->io_bs, pool_size))
1042		goto out_free_pools;
1043init_bs:
1044	if (bioset_init(&pools->bs, pool_size, front_pad, 0))
1045		goto out_free_pools;
1046	if (t->integrity_supported &&
1047	    bioset_integrity_create(&pools->bs, pool_size))
1048		goto out_free_pools;
1049
1050	t->mempools = pools;
1051	return 0;
1052
1053out_free_pools:
1054	dm_free_md_mempools(pools);
1055	return -ENOMEM;
1056}
1057
1058static int setup_indexes(struct dm_table *t)
1059{
1060	int i;
1061	unsigned int total = 0;
1062	sector_t *indexes;
1063
1064	/* allocate the space for *all* the indexes */
1065	for (i = t->depth - 2; i >= 0; i--) {
1066		t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
1067		total += t->counts[i];
1068	}
1069
1070	indexes = kvcalloc(total, NODE_SIZE, GFP_KERNEL);
1071	if (!indexes)
1072		return -ENOMEM;
1073
1074	/* set up internal nodes, bottom-up */
1075	for (i = t->depth - 2; i >= 0; i--) {
1076		t->index[i] = indexes;
1077		indexes += (KEYS_PER_NODE * t->counts[i]);
1078		setup_btree_index(i, t);
1079	}
1080
1081	return 0;
1082}
1083
1084/*
1085 * Builds the btree to index the map.
1086 */
1087static int dm_table_build_index(struct dm_table *t)
1088{
1089	int r = 0;
1090	unsigned int leaf_nodes;
1091
1092	/* how many indexes will the btree have ? */
1093	leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
1094	t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
1095
1096	/* leaf layer has already been set up */
1097	t->counts[t->depth - 1] = leaf_nodes;
1098	t->index[t->depth - 1] = t->highs;
1099
1100	if (t->depth >= 2)
1101		r = setup_indexes(t);
1102
1103	return r;
1104}
1105
1106static bool integrity_profile_exists(struct gendisk *disk)
1107{
1108	return !!blk_get_integrity(disk);
1109}
1110
1111/*
1112 * Get a disk whose integrity profile reflects the table's profile.
 
 
 
1113 * Returns NULL if integrity support was inconsistent or unavailable.
1114 */
1115static struct gendisk *dm_table_get_integrity_disk(struct dm_table *t)
 
1116{
1117	struct list_head *devices = dm_table_get_devices(t);
1118	struct dm_dev_internal *dd = NULL;
1119	struct gendisk *prev_disk = NULL, *template_disk = NULL;
1120
1121	for (unsigned int i = 0; i < t->num_targets; i++) {
1122		struct dm_target *ti = dm_table_get_target(t, i);
1123
1124		if (!dm_target_passes_integrity(ti->type))
1125			goto no_integrity;
1126	}
1127
1128	list_for_each_entry(dd, devices, list) {
1129		template_disk = dd->dm_dev->bdev->bd_disk;
1130		if (!integrity_profile_exists(template_disk))
1131			goto no_integrity;
 
 
1132		else if (prev_disk &&
1133			 blk_integrity_compare(prev_disk, template_disk) < 0)
1134			goto no_integrity;
1135		prev_disk = template_disk;
1136	}
1137
1138	return template_disk;
1139
1140no_integrity:
1141	if (prev_disk)
1142		DMWARN("%s: integrity not set: %s and %s profile mismatch",
1143		       dm_device_name(t->md),
1144		       prev_disk->disk_name,
1145		       template_disk->disk_name);
1146	return NULL;
1147}
1148
1149/*
1150 * Register the mapped device for blk_integrity support if the
1151 * underlying devices have an integrity profile.  But all devices may
1152 * not have matching profiles (checking all devices isn't reliable
1153 * during table load because this table may use other DM device(s) which
1154 * must be resumed before they will have an initialized integity
1155 * profile).  Consequently, stacked DM devices force a 2 stage integrity
1156 * profile validation: First pass during table load, final pass during
1157 * resume.
1158 */
1159static int dm_table_register_integrity(struct dm_table *t)
1160{
1161	struct mapped_device *md = t->md;
1162	struct gendisk *template_disk = NULL;
1163
1164	/* If target handles integrity itself do not register it here. */
1165	if (t->integrity_added)
1166		return 0;
1167
1168	template_disk = dm_table_get_integrity_disk(t);
1169	if (!template_disk)
1170		return 0;
1171
1172	if (!integrity_profile_exists(dm_disk(md))) {
1173		t->integrity_supported = true;
1174		/*
1175		 * Register integrity profile during table load; we can do
1176		 * this because the final profile must match during resume.
1177		 */
1178		blk_integrity_register(dm_disk(md),
1179				       blk_get_integrity(template_disk));
1180		return 0;
1181	}
1182
1183	/*
1184	 * If DM device already has an initialized integrity
1185	 * profile the new profile should not conflict.
1186	 */
1187	if (blk_integrity_compare(dm_disk(md), template_disk) < 0) {
1188		DMERR("%s: conflict with existing integrity profile: "
1189		      "%s profile mismatch",
1190		      dm_device_name(t->md),
1191		      template_disk->disk_name);
 
1192		return 1;
1193	}
1194
1195	/* Preserve existing integrity profile */
1196	t->integrity_supported = true;
1197	return 0;
1198}
1199
1200#ifdef CONFIG_BLK_INLINE_ENCRYPTION
1201
1202struct dm_crypto_profile {
1203	struct blk_crypto_profile profile;
1204	struct mapped_device *md;
1205};
1206
1207struct dm_keyslot_evict_args {
1208	const struct blk_crypto_key *key;
1209	int err;
1210};
1211
1212static int dm_keyslot_evict_callback(struct dm_target *ti, struct dm_dev *dev,
1213				     sector_t start, sector_t len, void *data)
1214{
1215	struct dm_keyslot_evict_args *args = data;
1216	int err;
1217
1218	err = blk_crypto_evict_key(dev->bdev, args->key);
1219	if (!args->err)
1220		args->err = err;
1221	/* Always try to evict the key from all devices. */
1222	return 0;
1223}
1224
1225/*
1226 * When an inline encryption key is evicted from a device-mapper device, evict
1227 * it from all the underlying devices.
1228 */
1229static int dm_keyslot_evict(struct blk_crypto_profile *profile,
1230			    const struct blk_crypto_key *key, unsigned int slot)
1231{
1232	struct mapped_device *md =
1233		container_of(profile, struct dm_crypto_profile, profile)->md;
1234	struct dm_keyslot_evict_args args = { key };
1235	struct dm_table *t;
1236	int srcu_idx;
1237
1238	t = dm_get_live_table(md, &srcu_idx);
1239	if (!t)
1240		return 0;
1241
1242	for (unsigned int i = 0; i < t->num_targets; i++) {
1243		struct dm_target *ti = dm_table_get_target(t, i);
1244
1245		if (!ti->type->iterate_devices)
1246			continue;
1247		ti->type->iterate_devices(ti, dm_keyslot_evict_callback, &args);
1248	}
1249
1250	dm_put_live_table(md, srcu_idx);
1251	return args.err;
1252}
1253
1254static int
1255device_intersect_crypto_capabilities(struct dm_target *ti, struct dm_dev *dev,
1256				     sector_t start, sector_t len, void *data)
1257{
1258	struct blk_crypto_profile *parent = data;
1259	struct blk_crypto_profile *child =
1260		bdev_get_queue(dev->bdev)->crypto_profile;
1261
1262	blk_crypto_intersect_capabilities(parent, child);
1263	return 0;
1264}
1265
1266void dm_destroy_crypto_profile(struct blk_crypto_profile *profile)
1267{
1268	struct dm_crypto_profile *dmcp = container_of(profile,
1269						      struct dm_crypto_profile,
1270						      profile);
1271
1272	if (!profile)
1273		return;
1274
1275	blk_crypto_profile_destroy(profile);
1276	kfree(dmcp);
1277}
1278
1279static void dm_table_destroy_crypto_profile(struct dm_table *t)
1280{
1281	dm_destroy_crypto_profile(t->crypto_profile);
1282	t->crypto_profile = NULL;
1283}
1284
1285/*
1286 * Constructs and initializes t->crypto_profile with a crypto profile that
1287 * represents the common set of crypto capabilities of the devices described by
1288 * the dm_table.  However, if the constructed crypto profile doesn't support all
1289 * crypto capabilities that are supported by the current mapped_device, it
1290 * returns an error instead, since we don't support removing crypto capabilities
1291 * on table changes.  Finally, if the constructed crypto profile is "empty" (has
1292 * no crypto capabilities at all), it just sets t->crypto_profile to NULL.
1293 */
1294static int dm_table_construct_crypto_profile(struct dm_table *t)
1295{
1296	struct dm_crypto_profile *dmcp;
1297	struct blk_crypto_profile *profile;
1298	unsigned int i;
1299	bool empty_profile = true;
1300
1301	dmcp = kmalloc(sizeof(*dmcp), GFP_KERNEL);
1302	if (!dmcp)
1303		return -ENOMEM;
1304	dmcp->md = t->md;
1305
1306	profile = &dmcp->profile;
1307	blk_crypto_profile_init(profile, 0);
1308	profile->ll_ops.keyslot_evict = dm_keyslot_evict;
1309	profile->max_dun_bytes_supported = UINT_MAX;
1310	memset(profile->modes_supported, 0xFF,
1311	       sizeof(profile->modes_supported));
1312
1313	for (i = 0; i < t->num_targets; i++) {
1314		struct dm_target *ti = dm_table_get_target(t, i);
1315
1316		if (!dm_target_passes_crypto(ti->type)) {
1317			blk_crypto_intersect_capabilities(profile, NULL);
1318			break;
1319		}
1320		if (!ti->type->iterate_devices)
1321			continue;
1322		ti->type->iterate_devices(ti,
1323					  device_intersect_crypto_capabilities,
1324					  profile);
1325	}
1326
1327	if (t->md->queue &&
1328	    !blk_crypto_has_capabilities(profile,
1329					 t->md->queue->crypto_profile)) {
1330		DMERR("Inline encryption capabilities of new DM table were more restrictive than the old table's. This is not supported!");
1331		dm_destroy_crypto_profile(profile);
1332		return -EINVAL;
1333	}
1334
1335	/*
1336	 * If the new profile doesn't actually support any crypto capabilities,
1337	 * we may as well represent it with a NULL profile.
1338	 */
1339	for (i = 0; i < ARRAY_SIZE(profile->modes_supported); i++) {
1340		if (profile->modes_supported[i]) {
1341			empty_profile = false;
1342			break;
1343		}
1344	}
1345
1346	if (empty_profile) {
1347		dm_destroy_crypto_profile(profile);
1348		profile = NULL;
1349	}
1350
1351	/*
1352	 * t->crypto_profile is only set temporarily while the table is being
1353	 * set up, and it gets set to NULL after the profile has been
1354	 * transferred to the request_queue.
1355	 */
1356	t->crypto_profile = profile;
1357
1358	return 0;
1359}
1360
1361static void dm_update_crypto_profile(struct request_queue *q,
1362				     struct dm_table *t)
1363{
1364	if (!t->crypto_profile)
1365		return;
1366
1367	/* Make the crypto profile less restrictive. */
1368	if (!q->crypto_profile) {
1369		blk_crypto_register(t->crypto_profile, q);
1370	} else {
1371		blk_crypto_update_capabilities(q->crypto_profile,
1372					       t->crypto_profile);
1373		dm_destroy_crypto_profile(t->crypto_profile);
1374	}
1375	t->crypto_profile = NULL;
1376}
1377
1378#else /* CONFIG_BLK_INLINE_ENCRYPTION */
1379
1380static int dm_table_construct_crypto_profile(struct dm_table *t)
1381{
1382	return 0;
1383}
1384
1385void dm_destroy_crypto_profile(struct blk_crypto_profile *profile)
1386{
1387}
1388
1389static void dm_table_destroy_crypto_profile(struct dm_table *t)
1390{
1391}
1392
1393static void dm_update_crypto_profile(struct request_queue *q,
1394				     struct dm_table *t)
1395{
1396}
1397
1398#endif /* !CONFIG_BLK_INLINE_ENCRYPTION */
1399
1400/*
1401 * Prepares the table for use by building the indices,
1402 * setting the type, and allocating mempools.
1403 */
1404int dm_table_complete(struct dm_table *t)
1405{
1406	int r;
1407
1408	r = dm_table_determine_type(t);
1409	if (r) {
1410		DMERR("unable to determine table type");
1411		return r;
1412	}
1413
1414	r = dm_table_build_index(t);
1415	if (r) {
1416		DMERR("unable to build btrees");
1417		return r;
1418	}
1419
1420	r = dm_table_register_integrity(t);
1421	if (r) {
1422		DMERR("could not register integrity profile.");
1423		return r;
1424	}
1425
1426	r = dm_table_construct_crypto_profile(t);
1427	if (r) {
1428		DMERR("could not construct crypto profile.");
1429		return r;
1430	}
1431
1432	r = dm_table_alloc_md_mempools(t, t->md);
1433	if (r)
1434		DMERR("unable to allocate mempools");
1435
1436	return r;
1437}
1438
1439static DEFINE_MUTEX(_event_lock);
1440void dm_table_event_callback(struct dm_table *t,
1441			     void (*fn)(void *), void *context)
1442{
1443	mutex_lock(&_event_lock);
1444	t->event_fn = fn;
1445	t->event_context = context;
1446	mutex_unlock(&_event_lock);
1447}
1448
1449void dm_table_event(struct dm_table *t)
1450{
 
 
 
 
 
 
1451	mutex_lock(&_event_lock);
1452	if (t->event_fn)
1453		t->event_fn(t->event_context);
1454	mutex_unlock(&_event_lock);
1455}
1456EXPORT_SYMBOL(dm_table_event);
1457
1458inline sector_t dm_table_get_size(struct dm_table *t)
1459{
1460	return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1461}
1462EXPORT_SYMBOL(dm_table_get_size);
1463
 
 
 
 
 
 
 
 
1464/*
1465 * Search the btree for the correct target.
1466 *
1467 * Caller should check returned pointer for NULL
1468 * to trap I/O beyond end of device.
1469 */
1470struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1471{
1472	unsigned int l, n = 0, k = 0;
1473	sector_t *node;
1474
1475	if (unlikely(sector >= dm_table_get_size(t)))
1476		return NULL;
1477
1478	for (l = 0; l < t->depth; l++) {
1479		n = get_child(n, k);
1480		node = get_node(t, l, n);
1481
1482		for (k = 0; k < KEYS_PER_NODE; k++)
1483			if (node[k] >= sector)
1484				break;
1485	}
1486
1487	return &t->targets[(KEYS_PER_NODE * n) + k];
1488}
1489
1490static int device_not_poll_capable(struct dm_target *ti, struct dm_dev *dev,
1491				   sector_t start, sector_t len, void *data)
1492{
1493	struct request_queue *q = bdev_get_queue(dev->bdev);
1494
1495	return !test_bit(QUEUE_FLAG_POLL, &q->queue_flags);
1496}
1497
1498/*
1499 * type->iterate_devices() should be called when the sanity check needs to
1500 * iterate and check all underlying data devices. iterate_devices() will
1501 * iterate all underlying data devices until it encounters a non-zero return
1502 * code, returned by whether the input iterate_devices_callout_fn, or
1503 * iterate_devices() itself internally.
1504 *
1505 * For some target type (e.g. dm-stripe), one call of iterate_devices() may
1506 * iterate multiple underlying devices internally, in which case a non-zero
1507 * return code returned by iterate_devices_callout_fn will stop the iteration
1508 * in advance.
1509 *
1510 * Cases requiring _any_ underlying device supporting some kind of attribute,
1511 * should use the iteration structure like dm_table_any_dev_attr(), or call
1512 * it directly. @func should handle semantics of positive examples, e.g.
1513 * capable of something.
1514 *
1515 * Cases requiring _all_ underlying devices supporting some kind of attribute,
1516 * should use the iteration structure like dm_table_supports_nowait() or
1517 * dm_table_supports_discards(). Or introduce dm_table_all_devs_attr() that
1518 * uses an @anti_func that handle semantics of counter examples, e.g. not
1519 * capable of something. So: return !dm_table_any_dev_attr(t, anti_func, data);
1520 */
1521static bool dm_table_any_dev_attr(struct dm_table *t,
1522				  iterate_devices_callout_fn func, void *data)
1523{
1524	for (unsigned int i = 0; i < t->num_targets; i++) {
1525		struct dm_target *ti = dm_table_get_target(t, i);
1526
1527		if (ti->type->iterate_devices &&
1528		    ti->type->iterate_devices(ti, func, data))
1529			return true;
1530        }
1531
1532	return false;
1533}
1534
1535static int count_device(struct dm_target *ti, struct dm_dev *dev,
1536			sector_t start, sector_t len, void *data)
1537{
1538	unsigned *num_devices = data;
1539
1540	(*num_devices)++;
1541
1542	return 0;
1543}
1544
1545static bool dm_table_supports_poll(struct dm_table *t)
1546{
1547	for (unsigned int i = 0; i < t->num_targets; i++) {
1548		struct dm_target *ti = dm_table_get_target(t, i);
1549
1550		if (!ti->type->iterate_devices ||
1551		    ti->type->iterate_devices(ti, device_not_poll_capable, NULL))
1552			return false;
1553	}
1554
1555	return true;
1556}
1557
1558/*
1559 * Check whether a table has no data devices attached using each
1560 * target's iterate_devices method.
1561 * Returns false if the result is unknown because a target doesn't
1562 * support iterate_devices.
1563 */
1564bool dm_table_has_no_data_devices(struct dm_table *t)
1565{
1566	for (unsigned int i = 0; i < t->num_targets; i++) {
1567		struct dm_target *ti = dm_table_get_target(t, i);
1568		unsigned num_devices = 0;
 
 
1569
1570		if (!ti->type->iterate_devices)
1571			return false;
1572
1573		ti->type->iterate_devices(ti, count_device, &num_devices);
1574		if (num_devices)
1575			return false;
1576	}
1577
1578	return true;
1579}
1580
1581static int device_not_zoned_model(struct dm_target *ti, struct dm_dev *dev,
1582				  sector_t start, sector_t len, void *data)
1583{
1584	struct request_queue *q = bdev_get_queue(dev->bdev);
1585	enum blk_zoned_model *zoned_model = data;
1586
1587	return blk_queue_zoned_model(q) != *zoned_model;
1588}
1589
1590/*
1591 * Check the device zoned model based on the target feature flag. If the target
1592 * has the DM_TARGET_ZONED_HM feature flag set, host-managed zoned devices are
1593 * also accepted but all devices must have the same zoned model. If the target
1594 * has the DM_TARGET_MIXED_ZONED_MODEL feature set, the devices can have any
1595 * zoned model with all zoned devices having the same zone size.
1596 */
1597static bool dm_table_supports_zoned_model(struct dm_table *t,
1598					  enum blk_zoned_model zoned_model)
1599{
1600	for (unsigned int i = 0; i < t->num_targets; i++) {
1601		struct dm_target *ti = dm_table_get_target(t, i);
1602
1603		if (dm_target_supports_zoned_hm(ti->type)) {
1604			if (!ti->type->iterate_devices ||
1605			    ti->type->iterate_devices(ti, device_not_zoned_model,
1606						      &zoned_model))
1607				return false;
1608		} else if (!dm_target_supports_mixed_zoned_model(ti->type)) {
1609			if (zoned_model == BLK_ZONED_HM)
1610				return false;
1611		}
1612	}
1613
1614	return true;
1615}
1616
1617static int device_not_matches_zone_sectors(struct dm_target *ti, struct dm_dev *dev,
1618					   sector_t start, sector_t len, void *data)
1619{
1620	unsigned int *zone_sectors = data;
1621
1622	if (!bdev_is_zoned(dev->bdev))
1623		return 0;
1624	return bdev_zone_sectors(dev->bdev) != *zone_sectors;
1625}
1626
1627/*
1628 * Check consistency of zoned model and zone sectors across all targets. For
1629 * zone sectors, if the destination device is a zoned block device, it shall
1630 * have the specified zone_sectors.
1631 */
1632static int validate_hardware_zoned_model(struct dm_table *t,
1633					 enum blk_zoned_model zoned_model,
1634					 unsigned int zone_sectors)
1635{
1636	if (zoned_model == BLK_ZONED_NONE)
1637		return 0;
1638
1639	if (!dm_table_supports_zoned_model(t, zoned_model)) {
1640		DMERR("%s: zoned model is not consistent across all devices",
1641		      dm_device_name(t->md));
1642		return -EINVAL;
1643	}
1644
1645	/* Check zone size validity and compatibility */
1646	if (!zone_sectors || !is_power_of_2(zone_sectors))
1647		return -EINVAL;
1648
1649	if (dm_table_any_dev_attr(t, device_not_matches_zone_sectors, &zone_sectors)) {
1650		DMERR("%s: zone sectors is not consistent across all zoned devices",
1651		      dm_device_name(t->md));
1652		return -EINVAL;
1653	}
1654
1655	return 0;
1656}
1657
1658/*
1659 * Establish the new table's queue_limits and validate them.
1660 */
1661int dm_calculate_queue_limits(struct dm_table *t,
1662			      struct queue_limits *limits)
1663{
 
1664	struct queue_limits ti_limits;
1665	enum blk_zoned_model zoned_model = BLK_ZONED_NONE;
1666	unsigned int zone_sectors = 0;
1667
1668	blk_set_stacking_limits(limits);
1669
1670	for (unsigned int i = 0; i < t->num_targets; i++) {
1671		struct dm_target *ti = dm_table_get_target(t, i);
1672
1673		blk_set_stacking_limits(&ti_limits);
1674
 
 
1675		if (!ti->type->iterate_devices)
1676			goto combine_limits;
1677
1678		/*
1679		 * Combine queue limits of all the devices this target uses.
1680		 */
1681		ti->type->iterate_devices(ti, dm_set_device_limits,
1682					  &ti_limits);
1683
1684		if (zoned_model == BLK_ZONED_NONE && ti_limits.zoned != BLK_ZONED_NONE) {
1685			/*
1686			 * After stacking all limits, validate all devices
1687			 * in table support this zoned model and zone sectors.
1688			 */
1689			zoned_model = ti_limits.zoned;
1690			zone_sectors = ti_limits.chunk_sectors;
1691		}
1692
1693		/* Set I/O hints portion of queue limits */
1694		if (ti->type->io_hints)
1695			ti->type->io_hints(ti, &ti_limits);
1696
1697		/*
1698		 * Check each device area is consistent with the target's
1699		 * overall queue limits.
1700		 */
1701		if (ti->type->iterate_devices(ti, device_area_is_invalid,
1702					      &ti_limits))
1703			return -EINVAL;
1704
1705combine_limits:
1706		/*
1707		 * Merge this target's queue limits into the overall limits
1708		 * for the table.
1709		 */
1710		if (blk_stack_limits(limits, &ti_limits, 0) < 0)
1711			DMWARN("%s: adding target device "
1712			       "(start sect %llu len %llu) "
1713			       "caused an alignment inconsistency",
1714			       dm_device_name(t->md),
1715			       (unsigned long long) ti->begin,
1716			       (unsigned long long) ti->len);
1717	}
1718
1719	/*
1720	 * Verify that the zoned model and zone sectors, as determined before
1721	 * any .io_hints override, are the same across all devices in the table.
1722	 * - this is especially relevant if .io_hints is emulating a disk-managed
1723	 *   zoned model (aka BLK_ZONED_NONE) on host-managed zoned block devices.
1724	 * BUT...
1725	 */
1726	if (limits->zoned != BLK_ZONED_NONE) {
1727		/*
1728		 * ...IF the above limits stacking determined a zoned model
1729		 * validate that all of the table's devices conform to it.
1730		 */
1731		zoned_model = limits->zoned;
1732		zone_sectors = limits->chunk_sectors;
1733	}
1734	if (validate_hardware_zoned_model(t, zoned_model, zone_sectors))
1735		return -EINVAL;
1736
1737	return validate_hardware_logical_block_alignment(t, limits);
1738}
1739
1740/*
1741 * Verify that all devices have an integrity profile that matches the
1742 * DM device's registered integrity profile.  If the profiles don't
1743 * match then unregister the DM device's integrity profile.
 
 
1744 */
1745static void dm_table_verify_integrity(struct dm_table *t)
1746{
1747	struct gendisk *template_disk = NULL;
1748
1749	if (t->integrity_added)
1750		return;
1751
1752	if (t->integrity_supported) {
1753		/*
1754		 * Verify that the original integrity profile
1755		 * matches all the devices in this table.
1756		 */
1757		template_disk = dm_table_get_integrity_disk(t);
1758		if (template_disk &&
1759		    blk_integrity_compare(dm_disk(t->md), template_disk) >= 0)
1760			return;
1761	}
1762
1763	if (integrity_profile_exists(dm_disk(t->md))) {
1764		DMWARN("%s: unable to establish an integrity profile",
1765		       dm_device_name(t->md));
1766		blk_integrity_unregister(dm_disk(t->md));
1767	}
1768}
1769
1770static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
1771				sector_t start, sector_t len, void *data)
1772{
1773	unsigned long flush = (unsigned long) data;
1774	struct request_queue *q = bdev_get_queue(dev->bdev);
1775
1776	return (q->queue_flags & flush);
1777}
1778
1779static bool dm_table_supports_flush(struct dm_table *t, unsigned long flush)
1780{
 
 
 
1781	/*
1782	 * Require at least one underlying device to support flushes.
1783	 * t->devices includes internal dm devices such as mirror logs
1784	 * so we need to use iterate_devices here, which targets
1785	 * supporting flushes must provide.
1786	 */
1787	for (unsigned int i = 0; i < t->num_targets; i++) {
1788		struct dm_target *ti = dm_table_get_target(t, i);
1789
1790		if (!ti->num_flush_bios)
1791			continue;
1792
1793		if (ti->flush_supported)
1794			return true;
1795
1796		if (ti->type->iterate_devices &&
1797		    ti->type->iterate_devices(ti, device_flush_capable, (void *) flush))
1798			return true;
1799	}
1800
1801	return false;
1802}
1803
1804static int device_dax_write_cache_enabled(struct dm_target *ti,
1805					  struct dm_dev *dev, sector_t start,
1806					  sector_t len, void *data)
1807{
1808	struct dax_device *dax_dev = dev->dax_dev;
 
1809
1810	if (!dax_dev)
1811		return false;
 
1812
1813	if (dax_write_cache_enabled(dax_dev))
1814		return true;
1815	return false;
1816}
1817
1818static int device_is_rotational(struct dm_target *ti, struct dm_dev *dev,
1819				sector_t start, sector_t len, void *data)
1820{
1821	return !bdev_nonrot(dev->bdev);
1822}
1823
1824static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
1825			     sector_t start, sector_t len, void *data)
1826{
1827	struct request_queue *q = bdev_get_queue(dev->bdev);
1828
1829	return !blk_queue_add_random(q);
1830}
1831
1832static int device_not_write_zeroes_capable(struct dm_target *ti, struct dm_dev *dev,
1833					   sector_t start, sector_t len, void *data)
1834{
1835	struct request_queue *q = bdev_get_queue(dev->bdev);
1836
1837	return !q->limits.max_write_zeroes_sectors;
1838}
1839
1840static bool dm_table_supports_write_zeroes(struct dm_table *t)
 
1841{
1842	for (unsigned int i = 0; i < t->num_targets; i++) {
1843		struct dm_target *ti = dm_table_get_target(t, i);
1844
1845		if (!ti->num_write_zeroes_bios)
1846			return false;
1847
1848		if (!ti->type->iterate_devices ||
1849		    ti->type->iterate_devices(ti, device_not_write_zeroes_capable, NULL))
1850			return false;
1851	}
1852
1853	return true;
1854}
1855
1856static int device_not_nowait_capable(struct dm_target *ti, struct dm_dev *dev,
1857				     sector_t start, sector_t len, void *data)
1858{
1859	return !bdev_nowait(dev->bdev);
1860}
1861
1862static bool dm_table_supports_nowait(struct dm_table *t)
1863{
1864	for (unsigned int i = 0; i < t->num_targets; i++) {
1865		struct dm_target *ti = dm_table_get_target(t, i);
1866
1867		if (!dm_target_supports_nowait(ti->type))
1868			return false;
1869
1870		if (!ti->type->iterate_devices ||
1871		    ti->type->iterate_devices(ti, device_not_nowait_capable, NULL))
1872			return false;
1873	}
1874
1875	return true;
1876}
1877
1878static int device_not_discard_capable(struct dm_target *ti, struct dm_dev *dev,
1879				      sector_t start, sector_t len, void *data)
1880{
1881	return !bdev_max_discard_sectors(dev->bdev);
1882}
1883
1884static bool dm_table_supports_discards(struct dm_table *t)
 
1885{
1886	for (unsigned int i = 0; i < t->num_targets; i++) {
1887		struct dm_target *ti = dm_table_get_target(t, i);
1888
1889		if (!ti->num_discard_bios)
1890			return false;
1891
1892		/*
1893		 * Either the target provides discard support (as implied by setting
1894		 * 'discards_supported') or it relies on _all_ data devices having
1895		 * discard support.
1896		 */
1897		if (!ti->discards_supported &&
1898		    (!ti->type->iterate_devices ||
1899		     ti->type->iterate_devices(ti, device_not_discard_capable, NULL)))
1900			return false;
1901	}
1902
1903	return true;
1904}
1905
1906static int device_not_secure_erase_capable(struct dm_target *ti,
1907					   struct dm_dev *dev, sector_t start,
1908					   sector_t len, void *data)
1909{
1910	return !bdev_max_secure_erase_sectors(dev->bdev);
1911}
1912
1913static bool dm_table_supports_secure_erase(struct dm_table *t)
1914{
1915	for (unsigned int i = 0; i < t->num_targets; i++) {
1916		struct dm_target *ti = dm_table_get_target(t, i);
1917
1918		if (!ti->num_secure_erase_bios)
1919			return false;
1920
1921		if (!ti->type->iterate_devices ||
1922		    ti->type->iterate_devices(ti, device_not_secure_erase_capable, NULL))
1923			return false;
1924	}
1925
1926	return true;
1927}
1928
1929static int device_requires_stable_pages(struct dm_target *ti,
1930					struct dm_dev *dev, sector_t start,
1931					sector_t len, void *data)
1932{
1933	return bdev_stable_writes(dev->bdev);
1934}
1935
1936int dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1937			      struct queue_limits *limits)
1938{
1939	bool wc = false, fua = false;
1940	int r;
1941
1942	/*
1943	 * Copy table's limits to the DM device's request_queue
1944	 */
1945	q->limits = *limits;
1946
1947	if (dm_table_supports_nowait(t))
1948		blk_queue_flag_set(QUEUE_FLAG_NOWAIT, q);
1949	else
1950		blk_queue_flag_clear(QUEUE_FLAG_NOWAIT, q);
1951
1952	if (!dm_table_supports_discards(t)) {
1953		q->limits.max_discard_sectors = 0;
1954		q->limits.max_hw_discard_sectors = 0;
1955		q->limits.discard_granularity = 0;
1956		q->limits.discard_alignment = 0;
1957		q->limits.discard_misaligned = 0;
1958	}
1959
1960	if (!dm_table_supports_secure_erase(t))
1961		q->limits.max_secure_erase_sectors = 0;
1962
1963	if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_WC))) {
1964		wc = true;
1965		if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_FUA)))
1966			fua = true;
1967	}
1968	blk_queue_write_cache(q, wc, fua);
1969
1970	if (dm_table_supports_dax(t, device_not_dax_capable)) {
1971		blk_queue_flag_set(QUEUE_FLAG_DAX, q);
1972		if (dm_table_supports_dax(t, device_not_dax_synchronous_capable))
1973			set_dax_synchronous(t->md->dax_dev);
1974	}
1975	else
1976		blk_queue_flag_clear(QUEUE_FLAG_DAX, q);
1977
1978	if (dm_table_any_dev_attr(t, device_dax_write_cache_enabled, NULL))
1979		dax_write_cache(t->md->dax_dev, true);
1980
1981	/* Ensure that all underlying devices are non-rotational. */
1982	if (dm_table_any_dev_attr(t, device_is_rotational, NULL))
1983		blk_queue_flag_clear(QUEUE_FLAG_NONROT, q);
1984	else
1985		blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
1986
1987	if (!dm_table_supports_write_zeroes(t))
1988		q->limits.max_write_zeroes_sectors = 0;
1989
1990	dm_table_verify_integrity(t);
1991
1992	/*
1993	 * Some devices don't use blk_integrity but still want stable pages
1994	 * because they do their own checksumming.
1995	 * If any underlying device requires stable pages, a table must require
1996	 * them as well.  Only targets that support iterate_devices are considered:
1997	 * don't want error, zero, etc to require stable pages.
1998	 */
1999	if (dm_table_any_dev_attr(t, device_requires_stable_pages, NULL))
2000		blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, q);
2001	else
2002		blk_queue_flag_clear(QUEUE_FLAG_STABLE_WRITES, q);
2003
2004	/*
2005	 * Determine whether or not this queue's I/O timings contribute
2006	 * to the entropy pool, Only request-based targets use this.
2007	 * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
2008	 * have it set.
2009	 */
2010	if (blk_queue_add_random(q) &&
2011	    dm_table_any_dev_attr(t, device_is_not_random, NULL))
2012		blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, q);
2013
2014	/*
2015	 * For a zoned target, setup the zones related queue attributes
2016	 * and resources necessary for zone append emulation if necessary.
 
 
 
 
 
2017	 */
2018	if (blk_queue_is_zoned(q)) {
2019		r = dm_set_zones_restrictions(t, q);
2020		if (r)
2021			return r;
2022		if (!static_key_enabled(&zoned_enabled.key))
2023			static_branch_enable(&zoned_enabled);
2024	}
2025
2026	dm_update_crypto_profile(q, t);
2027	disk_update_readahead(t->md->disk);
2028
2029	/*
2030	 * Check for request-based device is left to
2031	 * dm_mq_init_request_queue()->blk_mq_init_allocated_queue().
2032	 *
2033	 * For bio-based device, only set QUEUE_FLAG_POLL when all
2034	 * underlying devices supporting polling.
2035	 */
2036	if (__table_type_bio_based(t->type)) {
2037		if (dm_table_supports_poll(t))
2038			blk_queue_flag_set(QUEUE_FLAG_POLL, q);
2039		else
2040			blk_queue_flag_clear(QUEUE_FLAG_POLL, q);
2041	}
2042
2043	return 0;
 
 
2044}
2045
2046struct list_head *dm_table_get_devices(struct dm_table *t)
2047{
2048	return &t->devices;
2049}
2050
2051fmode_t dm_table_get_mode(struct dm_table *t)
2052{
2053	return t->mode;
2054}
2055EXPORT_SYMBOL(dm_table_get_mode);
2056
2057enum suspend_mode {
2058	PRESUSPEND,
2059	PRESUSPEND_UNDO,
2060	POSTSUSPEND,
2061};
2062
2063static void suspend_targets(struct dm_table *t, enum suspend_mode mode)
2064{
2065	lockdep_assert_held(&t->md->suspend_lock);
 
2066
2067	for (unsigned int i = 0; i < t->num_targets; i++) {
2068		struct dm_target *ti = dm_table_get_target(t, i);
2069
2070		switch (mode) {
2071		case PRESUSPEND:
2072			if (ti->type->presuspend)
2073				ti->type->presuspend(ti);
2074			break;
2075		case PRESUSPEND_UNDO:
2076			if (ti->type->presuspend_undo)
2077				ti->type->presuspend_undo(ti);
2078			break;
2079		case POSTSUSPEND:
2080			if (ti->type->postsuspend)
2081				ti->type->postsuspend(ti);
2082			break;
2083		}
 
 
2084	}
2085}
2086
2087void dm_table_presuspend_targets(struct dm_table *t)
2088{
2089	if (!t)
2090		return;
2091
2092	suspend_targets(t, PRESUSPEND);
2093}
2094
2095void dm_table_presuspend_undo_targets(struct dm_table *t)
2096{
2097	if (!t)
2098		return;
2099
2100	suspend_targets(t, PRESUSPEND_UNDO);
2101}
2102
2103void dm_table_postsuspend_targets(struct dm_table *t)
2104{
2105	if (!t)
2106		return;
2107
2108	suspend_targets(t, POSTSUSPEND);
2109}
2110
2111int dm_table_resume_targets(struct dm_table *t)
2112{
2113	unsigned int i;
2114	int r = 0;
2115
2116	lockdep_assert_held(&t->md->suspend_lock);
2117
2118	for (i = 0; i < t->num_targets; i++) {
2119		struct dm_target *ti = dm_table_get_target(t, i);
2120
2121		if (!ti->type->preresume)
2122			continue;
2123
2124		r = ti->type->preresume(ti);
2125		if (r) {
2126			DMERR("%s: %s: preresume failed, error = %d",
2127			      dm_device_name(t->md), ti->type->name, r);
2128			return r;
2129		}
2130	}
2131
2132	for (i = 0; i < t->num_targets; i++) {
2133		struct dm_target *ti = dm_table_get_target(t, i);
2134
2135		if (ti->type->resume)
2136			ti->type->resume(ti);
2137	}
2138
2139	return 0;
2140}
2141
2142struct mapped_device *dm_table_get_md(struct dm_table *t)
2143{
2144	return t->md;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2145}
2146EXPORT_SYMBOL(dm_table_get_md);
2147
2148const char *dm_table_device_name(struct dm_table *t)
2149{
2150	return dm_device_name(t->md);
2151}
2152EXPORT_SYMBOL_GPL(dm_table_device_name);
2153
2154void dm_table_run_md_queue_async(struct dm_table *t)
2155{
 
 
 
 
2156	if (!dm_table_request_based(t))
2157		return;
2158
2159	if (t->md->queue)
2160		blk_mq_run_hw_queues(t->md->queue, true);
 
 
 
 
 
2161}
2162EXPORT_SYMBOL(dm_table_run_md_queue_async);
2163
v3.15
   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.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
  22#define DM_MSG_PREFIX "table"
  23
  24#define MAX_DEPTH 16
  25#define NODE_SIZE L1_CACHE_BYTES
  26#define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t))
  27#define CHILDREN_PER_NODE (KEYS_PER_NODE + 1)
  28
  29struct dm_table {
  30	struct mapped_device *md;
  31	unsigned type;
  32
  33	/* btree table */
  34	unsigned int depth;
  35	unsigned int counts[MAX_DEPTH];	/* in nodes */
  36	sector_t *index[MAX_DEPTH];
  37
  38	unsigned int num_targets;
  39	unsigned int num_allocated;
  40	sector_t *highs;
  41	struct dm_target *targets;
  42
  43	struct target_type *immutable_target_type;
  44	unsigned integrity_supported:1;
  45	unsigned singleton:1;
  46
  47	/*
  48	 * Indicates the rw permissions for the new logical
  49	 * device.  This should be a combination of FMODE_READ
  50	 * and FMODE_WRITE.
  51	 */
  52	fmode_t mode;
  53
  54	/* a list of devices used by this table */
  55	struct list_head devices;
  56
  57	/* events get handed up using this callback */
  58	void (*event_fn)(void *);
  59	void *event_context;
  60
  61	struct dm_md_mempools *mempools;
  62
  63	struct list_head target_callbacks;
  64};
  65
  66/*
  67 * Similar to ceiling(log_size(n))
  68 */
  69static unsigned int int_log(unsigned int n, unsigned int base)
  70{
  71	int result = 0;
  72
  73	while (n > 1) {
  74		n = dm_div_up(n, base);
  75		result++;
  76	}
  77
  78	return result;
  79}
  80
  81/*
  82 * Calculate the index of the child node of the n'th node k'th key.
  83 */
  84static inline unsigned int get_child(unsigned int n, unsigned int k)
  85{
  86	return (n * CHILDREN_PER_NODE) + k;
  87}
  88
  89/*
  90 * Return the n'th node of level l from table t.
  91 */
  92static inline sector_t *get_node(struct dm_table *t,
  93				 unsigned int l, unsigned int n)
  94{
  95	return t->index[l] + (n * KEYS_PER_NODE);
  96}
  97
  98/*
  99 * Return the highest key that you could lookup from the n'th
 100 * node on level l of the btree.
 101 */
 102static sector_t high(struct dm_table *t, unsigned int l, unsigned int n)
 103{
 104	for (; l < t->depth - 1; l++)
 105		n = get_child(n, CHILDREN_PER_NODE - 1);
 106
 107	if (n >= t->counts[l])
 108		return (sector_t) - 1;
 109
 110	return get_node(t, l, n)[KEYS_PER_NODE - 1];
 111}
 112
 113/*
 114 * Fills in a level of the btree based on the highs of the level
 115 * below it.
 116 */
 117static int setup_btree_index(unsigned int l, struct dm_table *t)
 118{
 119	unsigned int n, k;
 120	sector_t *node;
 121
 122	for (n = 0U; n < t->counts[l]; n++) {
 123		node = get_node(t, l, n);
 124
 125		for (k = 0U; k < KEYS_PER_NODE; k++)
 126			node[k] = high(t, l + 1, get_child(n, k));
 127	}
 128
 129	return 0;
 130}
 131
 132void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size)
 133{
 134	unsigned long size;
 135	void *addr;
 136
 137	/*
 138	 * Check that we're not going to overflow.
 139	 */
 140	if (nmemb > (ULONG_MAX / elem_size))
 141		return NULL;
 142
 143	size = nmemb * elem_size;
 144	addr = vzalloc(size);
 145
 146	return addr;
 147}
 148EXPORT_SYMBOL(dm_vcalloc);
 149
 150/*
 151 * highs, and targets are managed as dynamic arrays during a
 152 * table load.
 153 */
 154static int alloc_targets(struct dm_table *t, unsigned int num)
 155{
 156	sector_t *n_highs;
 157	struct dm_target *n_targets;
 158
 159	/*
 160	 * Allocate both the target array and offset array at once.
 161	 * Append an empty entry to catch sectors beyond the end of
 162	 * the device.
 163	 */
 164	n_highs = (sector_t *) dm_vcalloc(num + 1, sizeof(struct dm_target) +
 165					  sizeof(sector_t));
 166	if (!n_highs)
 167		return -ENOMEM;
 168
 169	n_targets = (struct dm_target *) (n_highs + num);
 170
 171	memset(n_highs, -1, sizeof(*n_highs) * num);
 172	vfree(t->highs);
 173
 174	t->num_allocated = num;
 175	t->highs = n_highs;
 176	t->targets = n_targets;
 177
 178	return 0;
 179}
 180
 181int dm_table_create(struct dm_table **result, fmode_t mode,
 182		    unsigned num_targets, struct mapped_device *md)
 183{
 184	struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
 185
 186	if (!t)
 187		return -ENOMEM;
 188
 189	INIT_LIST_HEAD(&t->devices);
 190	INIT_LIST_HEAD(&t->target_callbacks);
 191
 192	if (!num_targets)
 193		num_targets = KEYS_PER_NODE;
 194
 195	num_targets = dm_round_up(num_targets, KEYS_PER_NODE);
 196
 197	if (!num_targets) {
 198		kfree(t);
 199		return -ENOMEM;
 200	}
 201
 202	if (alloc_targets(t, num_targets)) {
 203		kfree(t);
 204		return -ENOMEM;
 205	}
 206
 
 207	t->mode = mode;
 208	t->md = md;
 209	*result = t;
 210	return 0;
 211}
 212
 213static void free_devices(struct list_head *devices)
 214{
 215	struct list_head *tmp, *next;
 216
 217	list_for_each_safe(tmp, next, devices) {
 218		struct dm_dev_internal *dd =
 219		    list_entry(tmp, struct dm_dev_internal, list);
 220		DMWARN("dm_table_destroy: dm_put_device call missing for %s",
 221		       dd->dm_dev.name);
 
 222		kfree(dd);
 223	}
 224}
 225
 
 
 226void dm_table_destroy(struct dm_table *t)
 227{
 228	unsigned int i;
 229
 230	if (!t)
 231		return;
 232
 233	/* free the indexes */
 234	if (t->depth >= 2)
 235		vfree(t->index[t->depth - 2]);
 236
 237	/* free the targets */
 238	for (i = 0; i < t->num_targets; i++) {
 239		struct dm_target *tgt = t->targets + i;
 240
 241		if (tgt->type->dtr)
 242			tgt->type->dtr(tgt);
 243
 244		dm_put_target_type(tgt->type);
 245	}
 246
 247	vfree(t->highs);
 248
 249	/* free the device list */
 250	free_devices(&t->devices);
 251
 252	dm_free_md_mempools(t->mempools);
 253
 
 
 254	kfree(t);
 255}
 256
 257/*
 258 * See if we've already got a device in the list.
 259 */
 260static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
 261{
 262	struct dm_dev_internal *dd;
 263
 264	list_for_each_entry (dd, l, list)
 265		if (dd->dm_dev.bdev->bd_dev == dev)
 266			return dd;
 267
 268	return NULL;
 269}
 270
 271/*
 272 * Open a device so we can use it as a map destination.
 273 */
 274static int open_dev(struct dm_dev_internal *d, dev_t dev,
 275		    struct mapped_device *md)
 276{
 277	static char *_claim_ptr = "I belong to device-mapper";
 278	struct block_device *bdev;
 279
 280	int r;
 281
 282	BUG_ON(d->dm_dev.bdev);
 283
 284	bdev = blkdev_get_by_dev(dev, d->dm_dev.mode | FMODE_EXCL, _claim_ptr);
 285	if (IS_ERR(bdev))
 286		return PTR_ERR(bdev);
 287
 288	r = bd_link_disk_holder(bdev, dm_disk(md));
 289	if (r) {
 290		blkdev_put(bdev, d->dm_dev.mode | FMODE_EXCL);
 291		return r;
 292	}
 293
 294	d->dm_dev.bdev = bdev;
 295	return 0;
 296}
 297
 298/*
 299 * Close a device that we've been using.
 300 */
 301static void close_dev(struct dm_dev_internal *d, struct mapped_device *md)
 302{
 303	if (!d->dm_dev.bdev)
 304		return;
 305
 306	bd_unlink_disk_holder(d->dm_dev.bdev, dm_disk(md));
 307	blkdev_put(d->dm_dev.bdev, d->dm_dev.mode | FMODE_EXCL);
 308	d->dm_dev.bdev = NULL;
 309}
 310
 311/*
 312 * If possible, this checks an area of a destination device is invalid.
 313 */
 314static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
 315				  sector_t start, sector_t len, void *data)
 316{
 317	struct request_queue *q;
 318	struct queue_limits *limits = data;
 319	struct block_device *bdev = dev->bdev;
 320	sector_t dev_size =
 321		i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
 322	unsigned short logical_block_size_sectors =
 323		limits->logical_block_size >> SECTOR_SHIFT;
 324	char b[BDEVNAME_SIZE];
 325
 326	/*
 327	 * Some devices exist without request functions,
 328	 * such as loop devices not yet bound to backing files.
 329	 * Forbid the use of such devices.
 330	 */
 331	q = bdev_get_queue(bdev);
 332	if (!q || !q->make_request_fn) {
 333		DMWARN("%s: %s is not yet initialised: "
 334		       "start=%llu, len=%llu, dev_size=%llu",
 335		       dm_device_name(ti->table->md), bdevname(bdev, b),
 336		       (unsigned long long)start,
 337		       (unsigned long long)len,
 338		       (unsigned long long)dev_size);
 339		return 1;
 340	}
 341
 342	if (!dev_size)
 343		return 0;
 344
 345	if ((start >= dev_size) || (start + len > dev_size)) {
 346		DMWARN("%s: %s too small for target: "
 347		       "start=%llu, len=%llu, dev_size=%llu",
 348		       dm_device_name(ti->table->md), bdevname(bdev, b),
 349		       (unsigned long long)start,
 350		       (unsigned long long)len,
 351		       (unsigned long long)dev_size);
 352		return 1;
 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 */
 385static 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_internal dd_new, dd_old;
 390
 391	dd_new = dd_old = *dd;
 392
 393	dd_new.dm_dev.mode |= new_mode;
 394	dd_new.dm_dev.bdev = NULL;
 395
 396	r = open_dev(&dd_new, dd->dm_dev.bdev->bd_dev, md);
 
 397	if (r)
 398		return r;
 399
 400	dd->dm_dev.mode |= new_mode;
 401	close_dev(&dd_old, md);
 402
 403	return 0;
 404}
 405
 406/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 407 * Add a device to the list, or just increment the usage count if
 408 * it's already present.
 409 */
 410int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
 411		  struct dm_dev **result)
 412{
 413	int r;
 414	dev_t uninitialized_var(dev);
 
 
 415	struct dm_dev_internal *dd;
 416	unsigned int major, minor;
 417	struct dm_table *t = ti->table;
 418	char dummy;
 419
 420	BUG_ON(!t);
 421
 422	if (sscanf(path, "%u:%u%c", &major, &minor, &dummy) == 2) {
 423		/* Extract the major/minor numbers */
 424		dev = MKDEV(major, minor);
 425		if (MAJOR(dev) != major || MINOR(dev) != minor)
 426			return -EOVERFLOW;
 427	} else {
 428		/* convert the path to a device */
 429		struct block_device *bdev = lookup_bdev(path);
 430
 431		if (IS_ERR(bdev))
 432			return PTR_ERR(bdev);
 433		dev = bdev->bd_dev;
 434		bdput(bdev);
 435	}
 436
 437	dd = find_device(&t->devices, dev);
 438	if (!dd) {
 439		dd = kmalloc(sizeof(*dd), GFP_KERNEL);
 440		if (!dd)
 441			return -ENOMEM;
 442
 443		dd->dm_dev.mode = mode;
 444		dd->dm_dev.bdev = NULL;
 445
 446		if ((r = open_dev(dd, dev, t->md))) {
 447			kfree(dd);
 448			return r;
 449		}
 450
 451		format_dev_t(dd->dm_dev.name, dev);
 452
 453		atomic_set(&dd->count, 0);
 454		list_add(&dd->list, &t->devices);
 
 455
 456	} else if (dd->dm_dev.mode != (mode | dd->dm_dev.mode)) {
 457		r = upgrade_mode(dd, mode, t->md);
 458		if (r)
 459			return r;
 460	}
 461	atomic_inc(&dd->count);
 462
 463	*result = &dd->dm_dev;
 464	return 0;
 465}
 466EXPORT_SYMBOL(dm_get_device);
 467
 468int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
 469			 sector_t start, sector_t len, void *data)
 470{
 471	struct queue_limits *limits = data;
 472	struct block_device *bdev = dev->bdev;
 473	struct request_queue *q = bdev_get_queue(bdev);
 474	char b[BDEVNAME_SIZE];
 475
 476	if (unlikely(!q)) {
 477		DMWARN("%s: Cannot set limits for nonexistent device %s",
 478		       dm_device_name(ti->table->md), bdevname(bdev, b));
 479		return 0;
 480	}
 481
 482	if (bdev_stack_limits(limits, bdev, start) < 0)
 483		DMWARN("%s: adding target device %s caused an alignment inconsistency: "
 
 484		       "physical_block_size=%u, logical_block_size=%u, "
 485		       "alignment_offset=%u, start=%llu",
 486		       dm_device_name(ti->table->md), bdevname(bdev, b),
 487		       q->limits.physical_block_size,
 488		       q->limits.logical_block_size,
 489		       q->limits.alignment_offset,
 490		       (unsigned long long) start << SECTOR_SHIFT);
 491
 492	/*
 493	 * Check if merge fn is supported.
 494	 * If not we'll force DM to use PAGE_SIZE or
 495	 * smaller I/O, just to be safe.
 496	 */
 497	if (dm_queue_merge_is_compulsory(q) && !ti->type->merge)
 498		blk_limits_max_hw_sectors(limits,
 499					  (unsigned int) (PAGE_SIZE >> 9));
 500	return 0;
 501}
 502EXPORT_SYMBOL_GPL(dm_set_device_limits);
 503
 504/*
 505 * Decrement a device's use count and remove it if necessary.
 506 */
 507void dm_put_device(struct dm_target *ti, struct dm_dev *d)
 508{
 509	struct dm_dev_internal *dd = container_of(d, struct dm_dev_internal,
 510						  dm_dev);
 
 511
 512	if (atomic_dec_and_test(&dd->count)) {
 513		close_dev(dd, ti->table->md);
 
 
 
 
 
 
 
 
 
 
 
 514		list_del(&dd->list);
 515		kfree(dd);
 516	}
 517}
 518EXPORT_SYMBOL(dm_put_device);
 519
 520/*
 521 * Checks to see if the target joins onto the end of the table.
 522 */
 523static int adjoin(struct dm_table *table, struct dm_target *ti)
 524{
 525	struct dm_target *prev;
 526
 527	if (!table->num_targets)
 528		return !ti->begin;
 529
 530	prev = &table->targets[table->num_targets - 1];
 531	return (ti->begin == (prev->begin + prev->len));
 532}
 533
 534/*
 535 * Used to dynamically allocate the arg array.
 536 *
 537 * We do first allocation with GFP_NOIO because dm-mpath and dm-thin must
 538 * process messages even if some device is suspended. These messages have a
 539 * small fixed number of arguments.
 540 *
 541 * On the other hand, dm-switch needs to process bulk data using messages and
 542 * excessive use of GFP_NOIO could cause trouble.
 543 */
 544static char **realloc_argv(unsigned *array_size, char **old_argv)
 545{
 546	char **argv;
 547	unsigned new_size;
 548	gfp_t gfp;
 549
 550	if (*array_size) {
 551		new_size = *array_size * 2;
 552		gfp = GFP_KERNEL;
 553	} else {
 554		new_size = 8;
 555		gfp = GFP_NOIO;
 556	}
 557	argv = kmalloc(new_size * sizeof(*argv), gfp);
 558	if (argv) {
 559		memcpy(argv, old_argv, *array_size * sizeof(*argv));
 560		*array_size = new_size;
 561	}
 562
 563	kfree(old_argv);
 564	return argv;
 565}
 566
 567/*
 568 * Destructively splits up the argument list to pass to ctr.
 569 */
 570int dm_split_args(int *argc, char ***argvp, char *input)
 571{
 572	char *start, *end = input, *out, **argv = NULL;
 573	unsigned array_size = 0;
 574
 575	*argc = 0;
 576
 577	if (!input) {
 578		*argvp = NULL;
 579		return 0;
 580	}
 581
 582	argv = realloc_argv(&array_size, argv);
 583	if (!argv)
 584		return -ENOMEM;
 585
 586	while (1) {
 587		/* Skip whitespace */
 588		start = skip_spaces(end);
 589
 590		if (!*start)
 591			break;	/* success, we hit the end */
 592
 593		/* 'out' is used to remove any back-quotes */
 594		end = out = start;
 595		while (*end) {
 596			/* Everything apart from '\0' can be quoted */
 597			if (*end == '\\' && *(end + 1)) {
 598				*out++ = *(end + 1);
 599				end += 2;
 600				continue;
 601			}
 602
 603			if (isspace(*end))
 604				break;	/* end of token */
 605
 606			*out++ = *end++;
 607		}
 608
 609		/* have we already filled the array ? */
 610		if ((*argc + 1) > array_size) {
 611			argv = realloc_argv(&array_size, argv);
 612			if (!argv)
 613				return -ENOMEM;
 614		}
 615
 616		/* we know this is whitespace */
 617		if (*end)
 618			end++;
 619
 620		/* terminate the string and put it in the array */
 621		*out = '\0';
 622		argv[*argc] = start;
 623		(*argc)++;
 624	}
 625
 626	*argvp = argv;
 627	return 0;
 628}
 629
 630/*
 631 * Impose necessary and sufficient conditions on a devices's table such
 632 * that any incoming bio which respects its logical_block_size can be
 633 * processed successfully.  If it falls across the boundary between
 634 * two or more targets, the size of each piece it gets split into must
 635 * be compatible with the logical_block_size of the target processing it.
 636 */
 637static int validate_hardware_logical_block_alignment(struct dm_table *table,
 638						 struct queue_limits *limits)
 639{
 640	/*
 641	 * This function uses arithmetic modulo the logical_block_size
 642	 * (in units of 512-byte sectors).
 643	 */
 644	unsigned short device_logical_block_size_sects =
 645		limits->logical_block_size >> SECTOR_SHIFT;
 646
 647	/*
 648	 * Offset of the start of the next table entry, mod logical_block_size.
 649	 */
 650	unsigned short next_target_start = 0;
 651
 652	/*
 653	 * Given an aligned bio that extends beyond the end of a
 654	 * target, how many sectors must the next target handle?
 655	 */
 656	unsigned short remaining = 0;
 657
 658	struct dm_target *uninitialized_var(ti);
 659	struct queue_limits ti_limits;
 660	unsigned i = 0;
 661
 662	/*
 663	 * Check each entry in the table in turn.
 664	 */
 665	while (i < dm_table_get_num_targets(table)) {
 666		ti = dm_table_get_target(table, i++);
 667
 668		blk_set_stacking_limits(&ti_limits);
 669
 670		/* combine all target devices' limits */
 671		if (ti->type->iterate_devices)
 672			ti->type->iterate_devices(ti, dm_set_device_limits,
 673						  &ti_limits);
 674
 675		/*
 676		 * If the remaining sectors fall entirely within this
 677		 * table entry are they compatible with its logical_block_size?
 678		 */
 679		if (remaining < ti->len &&
 680		    remaining & ((ti_limits.logical_block_size >>
 681				  SECTOR_SHIFT) - 1))
 682			break;	/* Error */
 683
 684		next_target_start =
 685		    (unsigned short) ((next_target_start + ti->len) &
 686				      (device_logical_block_size_sects - 1));
 687		remaining = next_target_start ?
 688		    device_logical_block_size_sects - next_target_start : 0;
 689	}
 690
 691	if (remaining) {
 692		DMWARN("%s: table line %u (start sect %llu len %llu) "
 693		       "not aligned to h/w logical block size %u",
 694		       dm_device_name(table->md), i,
 695		       (unsigned long long) ti->begin,
 696		       (unsigned long long) ti->len,
 697		       limits->logical_block_size);
 698		return -EINVAL;
 699	}
 700
 701	return 0;
 702}
 703
 704int dm_table_add_target(struct dm_table *t, const char *type,
 705			sector_t start, sector_t len, char *params)
 706{
 707	int r = -EINVAL, argc;
 708	char **argv;
 709	struct dm_target *tgt;
 710
 711	if (t->singleton) {
 712		DMERR("%s: target type %s must appear alone in table",
 713		      dm_device_name(t->md), t->targets->type->name);
 714		return -EINVAL;
 715	}
 716
 717	BUG_ON(t->num_targets >= t->num_allocated);
 718
 719	tgt = t->targets + t->num_targets;
 720	memset(tgt, 0, sizeof(*tgt));
 721
 722	if (!len) {
 723		DMERR("%s: zero-length target", dm_device_name(t->md));
 724		return -EINVAL;
 725	}
 726
 727	tgt->type = dm_get_target_type(type);
 728	if (!tgt->type) {
 729		DMERR("%s: %s: unknown target type", dm_device_name(t->md),
 730		      type);
 731		return -EINVAL;
 732	}
 733
 734	if (dm_target_needs_singleton(tgt->type)) {
 735		if (t->num_targets) {
 736			DMERR("%s: target type %s must appear alone in table",
 737			      dm_device_name(t->md), type);
 738			return -EINVAL;
 739		}
 740		t->singleton = 1;
 741	}
 742
 743	if (dm_target_always_writeable(tgt->type) && !(t->mode & FMODE_WRITE)) {
 744		DMERR("%s: target type %s may not be included in read-only tables",
 745		      dm_device_name(t->md), type);
 746		return -EINVAL;
 747	}
 748
 749	if (t->immutable_target_type) {
 750		if (t->immutable_target_type != tgt->type) {
 751			DMERR("%s: immutable target type %s cannot be mixed with other target types",
 752			      dm_device_name(t->md), t->immutable_target_type->name);
 753			return -EINVAL;
 754		}
 755	} else if (dm_target_is_immutable(tgt->type)) {
 756		if (t->num_targets) {
 757			DMERR("%s: immutable target type %s cannot be mixed with other target types",
 758			      dm_device_name(t->md), tgt->type->name);
 759			return -EINVAL;
 760		}
 761		t->immutable_target_type = tgt->type;
 762	}
 763
 764	tgt->table = t;
 765	tgt->begin = start;
 766	tgt->len = len;
 767	tgt->error = "Unknown error";
 
 
 
 768
 769	/*
 770	 * Does this target adjoin the previous one ?
 771	 */
 772	if (!adjoin(t, tgt)) {
 773		tgt->error = "Gap in table";
 774		r = -EINVAL;
 775		goto bad;
 776	}
 777
 778	r = dm_split_args(&argc, &argv, params);
 779	if (r) {
 780		tgt->error = "couldn't split parameters (insufficient memory)";
 781		goto bad;
 782	}
 783
 784	r = tgt->type->ctr(tgt, argc, argv);
 785	kfree(argv);
 786	if (r)
 787		goto bad;
 788
 789	t->highs[t->num_targets++] = tgt->begin + tgt->len - 1;
 790
 791	if (!tgt->num_discard_bios && tgt->discards_supported)
 792		DMWARN("%s: %s: ignoring discards_supported because num_discard_bios is zero.",
 793		       dm_device_name(t->md), type);
 794
 
 
 
 795	return 0;
 796
 797 bad:
 798	DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error);
 799	dm_put_target_type(tgt->type);
 800	return r;
 801}
 802
 803/*
 804 * Target argument parsing helpers.
 805 */
 806static int validate_next_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
 
 807			     unsigned *value, char **error, unsigned grouped)
 808{
 809	const char *arg_str = dm_shift_arg(arg_set);
 810	char dummy;
 811
 812	if (!arg_str ||
 813	    (sscanf(arg_str, "%u%c", value, &dummy) != 1) ||
 814	    (*value < arg->min) ||
 815	    (*value > arg->max) ||
 816	    (grouped && arg_set->argc < *value)) {
 817		*error = arg->error;
 818		return -EINVAL;
 819	}
 820
 821	return 0;
 822}
 823
 824int dm_read_arg(struct dm_arg *arg, struct dm_arg_set *arg_set,
 825		unsigned *value, char **error)
 826{
 827	return validate_next_arg(arg, arg_set, value, error, 0);
 828}
 829EXPORT_SYMBOL(dm_read_arg);
 830
 831int dm_read_arg_group(struct dm_arg *arg, struct dm_arg_set *arg_set,
 832		      unsigned *value, char **error)
 833{
 834	return validate_next_arg(arg, arg_set, value, error, 1);
 835}
 836EXPORT_SYMBOL(dm_read_arg_group);
 837
 838const char *dm_shift_arg(struct dm_arg_set *as)
 839{
 840	char *r;
 841
 842	if (as->argc) {
 843		as->argc--;
 844		r = *as->argv;
 845		as->argv++;
 846		return r;
 847	}
 848
 849	return NULL;
 850}
 851EXPORT_SYMBOL(dm_shift_arg);
 852
 853void dm_consume_args(struct dm_arg_set *as, unsigned num_args)
 854{
 855	BUG_ON(as->argc < num_args);
 856	as->argc -= num_args;
 857	as->argv += num_args;
 858}
 859EXPORT_SYMBOL(dm_consume_args);
 860
 861static int dm_table_set_type(struct dm_table *t)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 862{
 863	unsigned i;
 864	unsigned bio_based = 0, request_based = 0, hybrid = 0;
 865	struct dm_target *tgt;
 866	struct dm_dev_internal *dd;
 867	struct list_head *devices;
 868	unsigned live_md_type;
 
 
 
 
 
 
 
 
 
 869
 870	for (i = 0; i < t->num_targets; i++) {
 871		tgt = t->targets + i;
 872		if (dm_target_hybrid(tgt))
 873			hybrid = 1;
 874		else if (dm_target_request_based(tgt))
 875			request_based = 1;
 876		else
 877			bio_based = 1;
 878
 879		if (bio_based && request_based) {
 880			DMWARN("Inconsistent table: different target types"
 881			       " can't be mixed up");
 882			return -EINVAL;
 883		}
 884	}
 885
 886	if (hybrid && !bio_based && !request_based) {
 887		/*
 888		 * The targets can work either way.
 889		 * Determine the type from the live device.
 890		 * Default to bio-based if device is new.
 891		 */
 892		live_md_type = dm_get_md_type(t->md);
 893		if (live_md_type == DM_TYPE_REQUEST_BASED)
 894			request_based = 1;
 895		else
 896			bio_based = 1;
 897	}
 898
 899	if (bio_based) {
 
 900		/* We must use this table as bio-based */
 901		t->type = DM_TYPE_BIO_BASED;
 
 
 
 
 902		return 0;
 903	}
 904
 905	BUG_ON(!request_based); /* No targets in this table */
 906
 907	/* Non-request-stackable devices can't be used for request-based dm */
 908	devices = dm_table_get_devices(t);
 909	list_for_each_entry(dd, devices, list) {
 910		if (!blk_queue_stackable(bdev_get_queue(dd->dm_dev.bdev))) {
 911			DMWARN("table load rejected: including"
 912			       " non-request-stackable devices");
 913			return -EINVAL;
 914		}
 915	}
 916
 
 917	/*
 918	 * Request-based dm supports only tables that have a single target now.
 919	 * To support multiple targets, request splitting support is needed,
 920	 * and that needs lots of changes in the block-layer.
 921	 * (e.g. request completion process for partial completion.)
 922	 */
 923	if (t->num_targets > 1) {
 924		DMWARN("Request-based dm doesn't support multiple targets yet");
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 925		return -EINVAL;
 926	}
 927
 928	t->type = DM_TYPE_REQUEST_BASED;
 
 
 
 
 
 929
 930	return 0;
 931}
 932
 933unsigned dm_table_get_type(struct dm_table *t)
 934{
 935	return t->type;
 936}
 937
 938struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
 939{
 940	return t->immutable_target_type;
 941}
 942
 943bool dm_table_request_based(struct dm_table *t)
 944{
 945	return dm_table_get_type(t) == DM_TYPE_REQUEST_BASED;
 
 
 
 
 
 946}
 947
 948static int dm_table_alloc_md_mempools(struct dm_table *t)
 949{
 950	unsigned type = dm_table_get_type(t);
 951	unsigned per_bio_data_size = 0;
 952	struct dm_target *tgt;
 953	unsigned i;
 954
 955	if (unlikely(type == DM_TYPE_NONE)) {
 956		DMWARN("no table type is set, can't allocate mempools");
 957		return -EINVAL;
 958	}
 959
 960	if (type == DM_TYPE_BIO_BASED)
 961		for (i = 0; i < t->num_targets; i++) {
 962			tgt = t->targets + i;
 963			per_bio_data_size = max(per_bio_data_size, tgt->per_bio_data_size);
 964		}
 965
 966	t->mempools = dm_alloc_md_mempools(type, t->integrity_supported, per_bio_data_size);
 967	if (!t->mempools)
 968		return -ENOMEM;
 969
 970	return 0;
 971}
 972
 973void dm_table_free_md_mempools(struct dm_table *t)
 974{
 975	dm_free_md_mempools(t->mempools);
 976	t->mempools = NULL;
 977}
 978
 979struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t)
 
 
 980{
 981	return t->mempools;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 982}
 983
 984static int setup_indexes(struct dm_table *t)
 985{
 986	int i;
 987	unsigned int total = 0;
 988	sector_t *indexes;
 989
 990	/* allocate the space for *all* the indexes */
 991	for (i = t->depth - 2; i >= 0; i--) {
 992		t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
 993		total += t->counts[i];
 994	}
 995
 996	indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE);
 997	if (!indexes)
 998		return -ENOMEM;
 999
1000	/* set up internal nodes, bottom-up */
1001	for (i = t->depth - 2; i >= 0; i--) {
1002		t->index[i] = indexes;
1003		indexes += (KEYS_PER_NODE * t->counts[i]);
1004		setup_btree_index(i, t);
1005	}
1006
1007	return 0;
1008}
1009
1010/*
1011 * Builds the btree to index the map.
1012 */
1013static int dm_table_build_index(struct dm_table *t)
1014{
1015	int r = 0;
1016	unsigned int leaf_nodes;
1017
1018	/* how many indexes will the btree have ? */
1019	leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
1020	t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
1021
1022	/* leaf layer has already been set up */
1023	t->counts[t->depth - 1] = leaf_nodes;
1024	t->index[t->depth - 1] = t->highs;
1025
1026	if (t->depth >= 2)
1027		r = setup_indexes(t);
1028
1029	return r;
1030}
1031
 
 
 
 
 
1032/*
1033 * Get a disk whose integrity profile reflects the table's profile.
1034 * If %match_all is true, all devices' profiles must match.
1035 * If %match_all is false, all devices must at least have an
1036 * allocated integrity profile; but uninitialized is ok.
1037 * Returns NULL if integrity support was inconsistent or unavailable.
1038 */
1039static struct gendisk * dm_table_get_integrity_disk(struct dm_table *t,
1040						    bool match_all)
1041{
1042	struct list_head *devices = dm_table_get_devices(t);
1043	struct dm_dev_internal *dd = NULL;
1044	struct gendisk *prev_disk = NULL, *template_disk = NULL;
1045
 
 
 
 
 
 
 
1046	list_for_each_entry(dd, devices, list) {
1047		template_disk = dd->dm_dev.bdev->bd_disk;
1048		if (!blk_get_integrity(template_disk))
1049			goto no_integrity;
1050		if (!match_all && !blk_integrity_is_initialized(template_disk))
1051			continue; /* skip uninitialized profiles */
1052		else if (prev_disk &&
1053			 blk_integrity_compare(prev_disk, template_disk) < 0)
1054			goto no_integrity;
1055		prev_disk = template_disk;
1056	}
1057
1058	return template_disk;
1059
1060no_integrity:
1061	if (prev_disk)
1062		DMWARN("%s: integrity not set: %s and %s profile mismatch",
1063		       dm_device_name(t->md),
1064		       prev_disk->disk_name,
1065		       template_disk->disk_name);
1066	return NULL;
1067}
1068
1069/*
1070 * Register the mapped device for blk_integrity support if
1071 * the underlying devices have an integrity profile.  But all devices
1072 * may not have matching profiles (checking all devices isn't reliable
1073 * during table load because this table may use other DM device(s) which
1074 * must be resumed before they will have an initialized integity profile).
1075 * Stacked DM devices force a 2 stage integrity profile validation:
1076 * 1 - during load, validate all initialized integrity profiles match
1077 * 2 - during resume, validate all integrity profiles match
1078 */
1079static int dm_table_prealloc_integrity(struct dm_table *t, struct mapped_device *md)
1080{
 
1081	struct gendisk *template_disk = NULL;
1082
1083	template_disk = dm_table_get_integrity_disk(t, false);
 
 
 
 
1084	if (!template_disk)
1085		return 0;
1086
1087	if (!blk_integrity_is_initialized(dm_disk(md))) {
1088		t->integrity_supported = 1;
1089		return blk_integrity_register(dm_disk(md), NULL);
 
 
 
 
 
 
1090	}
1091
1092	/*
1093	 * If DM device already has an initalized integrity
1094	 * profile the new profile should not conflict.
1095	 */
1096	if (blk_integrity_is_initialized(template_disk) &&
1097	    blk_integrity_compare(dm_disk(md), template_disk) < 0) {
1098		DMWARN("%s: conflict with existing integrity profile: "
1099		       "%s profile mismatch",
1100		       dm_device_name(t->md),
1101		       template_disk->disk_name);
1102		return 1;
1103	}
1104
1105	/* Preserve existing initialized integrity profile */
1106	t->integrity_supported = 1;
1107	return 0;
1108}
1109
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1110/*
1111 * Prepares the table for use by building the indices,
1112 * setting the type, and allocating mempools.
1113 */
1114int dm_table_complete(struct dm_table *t)
1115{
1116	int r;
1117
1118	r = dm_table_set_type(t);
1119	if (r) {
1120		DMERR("unable to set table type");
1121		return r;
1122	}
1123
1124	r = dm_table_build_index(t);
1125	if (r) {
1126		DMERR("unable to build btrees");
1127		return r;
1128	}
1129
1130	r = dm_table_prealloc_integrity(t, t->md);
1131	if (r) {
1132		DMERR("could not register integrity profile.");
1133		return r;
1134	}
1135
1136	r = dm_table_alloc_md_mempools(t);
 
 
 
 
 
 
1137	if (r)
1138		DMERR("unable to allocate mempools");
1139
1140	return r;
1141}
1142
1143static DEFINE_MUTEX(_event_lock);
1144void dm_table_event_callback(struct dm_table *t,
1145			     void (*fn)(void *), void *context)
1146{
1147	mutex_lock(&_event_lock);
1148	t->event_fn = fn;
1149	t->event_context = context;
1150	mutex_unlock(&_event_lock);
1151}
1152
1153void dm_table_event(struct dm_table *t)
1154{
1155	/*
1156	 * You can no longer call dm_table_event() from interrupt
1157	 * context, use a bottom half instead.
1158	 */
1159	BUG_ON(in_interrupt());
1160
1161	mutex_lock(&_event_lock);
1162	if (t->event_fn)
1163		t->event_fn(t->event_context);
1164	mutex_unlock(&_event_lock);
1165}
1166EXPORT_SYMBOL(dm_table_event);
1167
1168sector_t dm_table_get_size(struct dm_table *t)
1169{
1170	return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1171}
1172EXPORT_SYMBOL(dm_table_get_size);
1173
1174struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index)
1175{
1176	if (index >= t->num_targets)
1177		return NULL;
1178
1179	return t->targets + index;
1180}
1181
1182/*
1183 * Search the btree for the correct target.
1184 *
1185 * Caller should check returned pointer with dm_target_is_valid()
1186 * to trap I/O beyond end of device.
1187 */
1188struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1189{
1190	unsigned int l, n = 0, k = 0;
1191	sector_t *node;
1192
 
 
 
1193	for (l = 0; l < t->depth; l++) {
1194		n = get_child(n, k);
1195		node = get_node(t, l, n);
1196
1197		for (k = 0; k < KEYS_PER_NODE; k++)
1198			if (node[k] >= sector)
1199				break;
1200	}
1201
1202	return &t->targets[(KEYS_PER_NODE * n) + k];
1203}
1204
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1205static int count_device(struct dm_target *ti, struct dm_dev *dev,
1206			sector_t start, sector_t len, void *data)
1207{
1208	unsigned *num_devices = data;
1209
1210	(*num_devices)++;
1211
1212	return 0;
1213}
1214
 
 
 
 
 
 
 
 
 
 
 
 
 
1215/*
1216 * Check whether a table has no data devices attached using each
1217 * target's iterate_devices method.
1218 * Returns false if the result is unknown because a target doesn't
1219 * support iterate_devices.
1220 */
1221bool dm_table_has_no_data_devices(struct dm_table *table)
1222{
1223	struct dm_target *uninitialized_var(ti);
1224	unsigned i = 0, num_devices = 0;
1225
1226	while (i < dm_table_get_num_targets(table)) {
1227		ti = dm_table_get_target(table, i++);
1228
1229		if (!ti->type->iterate_devices)
1230			return false;
1231
1232		ti->type->iterate_devices(ti, count_device, &num_devices);
1233		if (num_devices)
1234			return false;
1235	}
1236
1237	return true;
1238}
1239
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1240/*
1241 * Establish the new table's queue_limits and validate them.
1242 */
1243int dm_calculate_queue_limits(struct dm_table *table,
1244			      struct queue_limits *limits)
1245{
1246	struct dm_target *uninitialized_var(ti);
1247	struct queue_limits ti_limits;
1248	unsigned i = 0;
 
1249
1250	blk_set_stacking_limits(limits);
1251
1252	while (i < dm_table_get_num_targets(table)) {
 
 
1253		blk_set_stacking_limits(&ti_limits);
1254
1255		ti = dm_table_get_target(table, i++);
1256
1257		if (!ti->type->iterate_devices)
1258			goto combine_limits;
1259
1260		/*
1261		 * Combine queue limits of all the devices this target uses.
1262		 */
1263		ti->type->iterate_devices(ti, dm_set_device_limits,
1264					  &ti_limits);
1265
 
 
 
 
 
 
 
 
 
1266		/* Set I/O hints portion of queue limits */
1267		if (ti->type->io_hints)
1268			ti->type->io_hints(ti, &ti_limits);
1269
1270		/*
1271		 * Check each device area is consistent with the target's
1272		 * overall queue limits.
1273		 */
1274		if (ti->type->iterate_devices(ti, device_area_is_invalid,
1275					      &ti_limits))
1276			return -EINVAL;
1277
1278combine_limits:
1279		/*
1280		 * Merge this target's queue limits into the overall limits
1281		 * for the table.
1282		 */
1283		if (blk_stack_limits(limits, &ti_limits, 0) < 0)
1284			DMWARN("%s: adding target device "
1285			       "(start sect %llu len %llu) "
1286			       "caused an alignment inconsistency",
1287			       dm_device_name(table->md),
1288			       (unsigned long long) ti->begin,
1289			       (unsigned long long) ti->len);
1290	}
1291
1292	return validate_hardware_logical_block_alignment(table, limits);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1293}
1294
1295/*
1296 * Set the integrity profile for this device if all devices used have
1297 * matching profiles.  We're quite deep in the resume path but still
1298 * don't know if all devices (particularly DM devices this device
1299 * may be stacked on) have matching profiles.  Even if the profiles
1300 * don't match we have no way to fail (to resume) at this point.
1301 */
1302static void dm_table_set_integrity(struct dm_table *t)
1303{
1304	struct gendisk *template_disk = NULL;
1305
1306	if (!blk_get_integrity(dm_disk(t->md)))
1307		return;
1308
1309	template_disk = dm_table_get_integrity_disk(t, true);
1310	if (template_disk)
1311		blk_integrity_register(dm_disk(t->md),
1312				       blk_get_integrity(template_disk));
1313	else if (blk_integrity_is_initialized(dm_disk(t->md)))
1314		DMWARN("%s: device no longer has a valid integrity profile",
1315		       dm_device_name(t->md));
1316	else
 
 
 
 
1317		DMWARN("%s: unable to establish an integrity profile",
1318		       dm_device_name(t->md));
 
 
1319}
1320
1321static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
1322				sector_t start, sector_t len, void *data)
1323{
1324	unsigned flush = (*(unsigned *)data);
1325	struct request_queue *q = bdev_get_queue(dev->bdev);
1326
1327	return q && (q->flush_flags & flush);
1328}
1329
1330static bool dm_table_supports_flush(struct dm_table *t, unsigned flush)
1331{
1332	struct dm_target *ti;
1333	unsigned i = 0;
1334
1335	/*
1336	 * Require at least one underlying device to support flushes.
1337	 * t->devices includes internal dm devices such as mirror logs
1338	 * so we need to use iterate_devices here, which targets
1339	 * supporting flushes must provide.
1340	 */
1341	while (i < dm_table_get_num_targets(t)) {
1342		ti = dm_table_get_target(t, i++);
1343
1344		if (!ti->num_flush_bios)
1345			continue;
1346
1347		if (ti->flush_supported)
1348			return 1;
1349
1350		if (ti->type->iterate_devices &&
1351		    ti->type->iterate_devices(ti, device_flush_capable, &flush))
1352			return 1;
1353	}
1354
1355	return 0;
1356}
1357
1358static bool dm_table_discard_zeroes_data(struct dm_table *t)
 
 
1359{
1360	struct dm_target *ti;
1361	unsigned i = 0;
1362
1363	/* Ensure that all targets supports discard_zeroes_data. */
1364	while (i < dm_table_get_num_targets(t)) {
1365		ti = dm_table_get_target(t, i++);
1366
1367		if (ti->discard_zeroes_data_unsupported)
1368			return 0;
1369	}
 
1370
1371	return 1;
 
 
 
1372}
1373
1374static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev,
1375			    sector_t start, sector_t len, void *data)
1376{
1377	struct request_queue *q = bdev_get_queue(dev->bdev);
1378
1379	return q && blk_queue_nonrot(q);
1380}
1381
1382static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
1383			     sector_t start, sector_t len, void *data)
1384{
1385	struct request_queue *q = bdev_get_queue(dev->bdev);
1386
1387	return q && !blk_queue_add_random(q);
1388}
1389
1390static bool dm_table_all_devices_attribute(struct dm_table *t,
1391					   iterate_devices_callout_fn func)
1392{
1393	struct dm_target *ti;
1394	unsigned i = 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1395
1396	while (i < dm_table_get_num_targets(t)) {
1397		ti = dm_table_get_target(t, i++);
1398
1399		if (!ti->type->iterate_devices ||
1400		    !ti->type->iterate_devices(ti, func, NULL))
1401			return 0;
1402	}
1403
1404	return 1;
 
 
 
 
 
 
1405}
1406
1407static int device_not_write_same_capable(struct dm_target *ti, struct dm_dev *dev,
1408					 sector_t start, sector_t len, void *data)
1409{
1410	struct request_queue *q = bdev_get_queue(dev->bdev);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1411
1412	return q && !q->limits.max_write_same_sectors;
1413}
1414
1415static bool dm_table_supports_write_same(struct dm_table *t)
 
 
1416{
1417	struct dm_target *ti;
1418	unsigned i = 0;
1419
1420	while (i < dm_table_get_num_targets(t)) {
1421		ti = dm_table_get_target(t, i++);
 
 
1422
1423		if (!ti->num_write_same_bios)
1424			return false;
1425
1426		if (!ti->type->iterate_devices ||
1427		    ti->type->iterate_devices(ti, device_not_write_same_capable, NULL))
1428			return false;
1429	}
1430
1431	return true;
1432}
1433
1434void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1435			       struct queue_limits *limits)
 
1436{
1437	unsigned flush = 0;
 
 
 
 
 
 
 
1438
1439	/*
1440	 * Copy table's limits to the DM device's request_queue
1441	 */
1442	q->limits = *limits;
1443
1444	if (!dm_table_supports_discards(t))
1445		queue_flag_clear_unlocked(QUEUE_FLAG_DISCARD, q);
1446	else
1447		queue_flag_set_unlocked(QUEUE_FLAG_DISCARD, q);
1448
1449	if (dm_table_supports_flush(t, REQ_FLUSH)) {
1450		flush |= REQ_FLUSH;
1451		if (dm_table_supports_flush(t, REQ_FUA))
1452			flush |= REQ_FUA;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1453	}
1454	blk_queue_flush(q, flush);
 
1455
1456	if (!dm_table_discard_zeroes_data(t))
1457		q->limits.discard_zeroes_data = 0;
1458
1459	/* Ensure that all underlying devices are non-rotational. */
1460	if (dm_table_all_devices_attribute(t, device_is_nonrot))
1461		queue_flag_set_unlocked(QUEUE_FLAG_NONROT, q);
1462	else
1463		queue_flag_clear_unlocked(QUEUE_FLAG_NONROT, q);
1464
1465	if (!dm_table_supports_write_same(t))
1466		q->limits.max_write_same_sectors = 0;
1467
1468	dm_table_set_integrity(t);
 
 
 
 
 
 
 
 
 
 
 
 
1469
1470	/*
1471	 * Determine whether or not this queue's I/O timings contribute
1472	 * to the entropy pool, Only request-based targets use this.
1473	 * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
1474	 * have it set.
1475	 */
1476	if (blk_queue_add_random(q) && dm_table_all_devices_attribute(t, device_is_not_random))
1477		queue_flag_clear_unlocked(QUEUE_FLAG_ADD_RANDOM, q);
 
1478
1479	/*
1480	 * QUEUE_FLAG_STACKABLE must be set after all queue settings are
1481	 * visible to other CPUs because, once the flag is set, incoming bios
1482	 * are processed by request-based dm, which refers to the queue
1483	 * settings.
1484	 * Until the flag set, bios are passed to bio-based dm and queued to
1485	 * md->deferred where queue settings are not needed yet.
1486	 * Those bios are passed to request-based dm at the resume time.
1487	 */
1488	smp_mb();
1489	if (dm_table_request_based(t))
1490		queue_flag_set_unlocked(QUEUE_FLAG_STACKABLE, q);
1491}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1492
1493unsigned int dm_table_get_num_targets(struct dm_table *t)
1494{
1495	return t->num_targets;
1496}
1497
1498struct list_head *dm_table_get_devices(struct dm_table *t)
1499{
1500	return &t->devices;
1501}
1502
1503fmode_t dm_table_get_mode(struct dm_table *t)
1504{
1505	return t->mode;
1506}
1507EXPORT_SYMBOL(dm_table_get_mode);
1508
1509static void suspend_targets(struct dm_table *t, unsigned postsuspend)
 
 
 
 
 
 
1510{
1511	int i = t->num_targets;
1512	struct dm_target *ti = t->targets;
1513
1514	while (i--) {
1515		if (postsuspend) {
 
 
 
 
 
 
 
 
 
 
 
1516			if (ti->type->postsuspend)
1517				ti->type->postsuspend(ti);
1518		} else if (ti->type->presuspend)
1519			ti->type->presuspend(ti);
1520
1521		ti++;
1522	}
1523}
1524
1525void dm_table_presuspend_targets(struct dm_table *t)
1526{
1527	if (!t)
1528		return;
1529
1530	suspend_targets(t, 0);
 
 
 
 
 
 
 
 
1531}
1532
1533void dm_table_postsuspend_targets(struct dm_table *t)
1534{
1535	if (!t)
1536		return;
1537
1538	suspend_targets(t, 1);
1539}
1540
1541int dm_table_resume_targets(struct dm_table *t)
1542{
1543	int i, r = 0;
 
 
 
1544
1545	for (i = 0; i < t->num_targets; i++) {
1546		struct dm_target *ti = t->targets + i;
1547
1548		if (!ti->type->preresume)
1549			continue;
1550
1551		r = ti->type->preresume(ti);
1552		if (r) {
1553			DMERR("%s: %s: preresume failed, error = %d",
1554			      dm_device_name(t->md), ti->type->name, r);
1555			return r;
1556		}
1557	}
1558
1559	for (i = 0; i < t->num_targets; i++) {
1560		struct dm_target *ti = t->targets + i;
1561
1562		if (ti->type->resume)
1563			ti->type->resume(ti);
1564	}
1565
1566	return 0;
1567}
1568
1569void dm_table_add_target_callbacks(struct dm_table *t, struct dm_target_callbacks *cb)
1570{
1571	list_add(&cb->list, &t->target_callbacks);
1572}
1573EXPORT_SYMBOL_GPL(dm_table_add_target_callbacks);
1574
1575int dm_table_any_congested(struct dm_table *t, int bdi_bits)
1576{
1577	struct dm_dev_internal *dd;
1578	struct list_head *devices = dm_table_get_devices(t);
1579	struct dm_target_callbacks *cb;
1580	int r = 0;
1581
1582	list_for_each_entry(dd, devices, list) {
1583		struct request_queue *q = bdev_get_queue(dd->dm_dev.bdev);
1584		char b[BDEVNAME_SIZE];
1585
1586		if (likely(q))
1587			r |= bdi_congested(&q->backing_dev_info, bdi_bits);
1588		else
1589			DMWARN_LIMIT("%s: any_congested: nonexistent device %s",
1590				     dm_device_name(t->md),
1591				     bdevname(dd->dm_dev.bdev, b));
1592	}
1593
1594	list_for_each_entry(cb, &t->target_callbacks, list)
1595		if (cb->congested_fn)
1596			r |= cb->congested_fn(cb, bdi_bits);
1597
1598	return r;
1599}
1600
1601int dm_table_any_busy_target(struct dm_table *t)
1602{
1603	unsigned i;
1604	struct dm_target *ti;
1605
1606	for (i = 0; i < t->num_targets; i++) {
1607		ti = t->targets + i;
1608		if (ti->type->busy && ti->type->busy(ti))
1609			return 1;
1610	}
1611
1612	return 0;
1613}
 
1614
1615struct mapped_device *dm_table_get_md(struct dm_table *t)
1616{
1617	return t->md;
1618}
1619EXPORT_SYMBOL(dm_table_get_md);
1620
1621void dm_table_run_md_queue_async(struct dm_table *t)
1622{
1623	struct mapped_device *md;
1624	struct request_queue *queue;
1625	unsigned long flags;
1626
1627	if (!dm_table_request_based(t))
1628		return;
1629
1630	md = dm_table_get_md(t);
1631	queue = dm_get_md_queue(md);
1632	if (queue) {
1633		spin_lock_irqsave(queue->queue_lock, flags);
1634		blk_run_queue_async(queue);
1635		spin_unlock_irqrestore(queue->queue_lock, flags);
1636	}
1637}
1638EXPORT_SYMBOL(dm_table_run_md_queue_async);
1639
1640static int device_discard_capable(struct dm_target *ti, struct dm_dev *dev,
1641				  sector_t start, sector_t len, void *data)
1642{
1643	struct request_queue *q = bdev_get_queue(dev->bdev);
1644
1645	return q && blk_queue_discard(q);
1646}
1647
1648bool dm_table_supports_discards(struct dm_table *t)
1649{
1650	struct dm_target *ti;
1651	unsigned i = 0;
1652
1653	/*
1654	 * Unless any target used by the table set discards_supported,
1655	 * require at least one underlying device to support discards.
1656	 * t->devices includes internal dm devices such as mirror logs
1657	 * so we need to use iterate_devices here, which targets
1658	 * supporting discard selectively must provide.
1659	 */
1660	while (i < dm_table_get_num_targets(t)) {
1661		ti = dm_table_get_target(t, i++);
1662
1663		if (!ti->num_discard_bios)
1664			continue;
1665
1666		if (ti->discards_supported)
1667			return 1;
1668
1669		if (ti->type->iterate_devices &&
1670		    ti->type->iterate_devices(ti, device_discard_capable, NULL))
1671			return 1;
1672	}
1673
1674	return 0;
1675}