1/*
   2 * Copyright (C) 2001 Sistina Software (UK) Limited.
   3 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
   4 *
   5 * This file is released under the GPL.
   6 */
   7
   8#include "dm-core.h"
   9
  10#include <linux/module.h>
  11#include <linux/vmalloc.h>
  12#include <linux/blkdev.h>
  13#include <linux/namei.h>
  14#include <linux/ctype.h>
  15#include <linux/string.h>
  16#include <linux/slab.h>
  17#include <linux/interrupt.h>
  18#include <linux/mutex.h>
  19#include <linux/delay.h>
  20#include <linux/atomic.h>
  21#include <linux/blk-mq.h>
  22#include <linux/mount.h>
  23#include <linux/dax.h>
  24
  25#define DM_MSG_PREFIX "table"
  26
  27#define MAX_DEPTH 16
  28#define NODE_SIZE L1_CACHE_BYTES
  29#define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t))
  30#define CHILDREN_PER_NODE (KEYS_PER_NODE + 1)
  31
  32struct dm_table {
  33	struct mapped_device *md;
  34	enum dm_queue_mode type;
  35
  36	/* btree table */
  37	unsigned int depth;
  38	unsigned int counts[MAX_DEPTH];	/* in nodes */
  39	sector_t *index[MAX_DEPTH];
  40
  41	unsigned int num_targets;
  42	unsigned int num_allocated;
  43	sector_t *highs;
  44	struct dm_target *targets;
  45
  46	struct target_type *immutable_target_type;
  47
  48	bool integrity_supported:1;
  49	bool singleton:1;
  50	unsigned integrity_added:1;
  51
  52	/*
  53	 * Indicates the rw permissions for the new logical
  54	 * device.  This should be a combination of FMODE_READ
  55	 * and FMODE_WRITE.
  56	 */
  57	fmode_t mode;
  58
  59	/* a list of devices used by this table */
  60	struct list_head devices;
  61
  62	/* events get handed up using this callback */
  63	void (*event_fn)(void *);
  64	void *event_context;
  65
  66	struct dm_md_mempools *mempools;
 
 
  67};
  68
  69/*
  70 * Similar to ceiling(log_size(n))
  71 */
  72static unsigned int int_log(unsigned int n, unsigned int base)
  73{
  74	int result = 0;
  75
  76	while (n > 1) {
  77		n = dm_div_up(n, base);
  78		result++;
  79	}
  80
  81	return result;
  82}
  83
  84/*
  85 * Calculate the index of the child node of the n'th node k'th key.
  86 */
  87static inline unsigned int get_child(unsigned int n, unsigned int k)
  88{
  89	return (n * CHILDREN_PER_NODE) + k;
  90}
  91
  92/*
  93 * Return the n'th node of level l from table t.
  94 */
  95static inline sector_t *get_node(struct dm_table *t,
  96				 unsigned int l, unsigned int n)
  97{
  98	return t->index[l] + (n * KEYS_PER_NODE);
  99}
 100
 101/*
 102 * Return the highest key that you could lookup from the n'th
 103 * node on level l of the btree.
 104 */
 105static sector_t high(struct dm_table *t, unsigned int l, unsigned int n)
 106{
 107	for (; l < t->depth - 1; l++)
 108		n = get_child(n, CHILDREN_PER_NODE - 1);
 109
 110	if (n >= t->counts[l])
 111		return (sector_t) - 1;
 112
 113	return get_node(t, l, n)[KEYS_PER_NODE - 1];
 114}
 115
 116/*
 117 * Fills in a level of the btree based on the highs of the level
 118 * below it.
 119 */
 120static int setup_btree_index(unsigned int l, struct dm_table *t)
 121{
 122	unsigned int n, k;
 123	sector_t *node;
 124
 125	for (n = 0U; n < t->counts[l]; n++) {
 126		node = get_node(t, l, n);
 127
 128		for (k = 0U; k < KEYS_PER_NODE; k++)
 129			node[k] = high(t, l + 1, get_child(n, k));
 130	}
 131
 132	return 0;
 133}
 134
 135void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size)
 136{
 137	unsigned long size;
 138	void *addr;
 139
 140	/*
 141	 * Check that we're not going to overflow.
 142	 */
 143	if (nmemb > (ULONG_MAX / elem_size))
 144		return NULL;
 145
 146	size = nmemb * elem_size;
 147	addr = vzalloc(size);
 148
 149	return addr;
 150}
 151EXPORT_SYMBOL(dm_vcalloc);
 152
 153/*
 154 * highs, and targets are managed as dynamic arrays during a
 155 * table load.
 156 */
 157static int alloc_targets(struct dm_table *t, unsigned int num)
 158{
 159	sector_t *n_highs;
 160	struct dm_target *n_targets;
 161
 162	/*
 163	 * Allocate both the target array and offset array at once.
 164	 */
 165	n_highs = (sector_t *) dm_vcalloc(num, sizeof(struct dm_target) +
 166					  sizeof(sector_t));
 167	if (!n_highs)
 168		return -ENOMEM;
 169
 170	n_targets = (struct dm_target *) (n_highs + num);
 171
 172	memset(n_highs, -1, sizeof(*n_highs) * num);
 173	vfree(t->highs);
 174
 175	t->num_allocated = num;
 176	t->highs = n_highs;
 177	t->targets = n_targets;
 178
 179	return 0;
 180}
 181
 182int dm_table_create(struct dm_table **result, fmode_t mode,
 183		    unsigned num_targets, struct mapped_device *md)
 184{
 185	struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL);
 186
 187	if (!t)
 188		return -ENOMEM;
 189
 190	INIT_LIST_HEAD(&t->devices);
 
 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->type = DM_TYPE_NONE;
 208	t->mode = mode;
 209	t->md = md;
 210	*result = t;
 211	return 0;
 212}
 213
 214static void free_devices(struct list_head *devices, struct mapped_device *md)
 215{
 216	struct list_head *tmp, *next;
 217
 218	list_for_each_safe(tmp, next, devices) {
 219		struct dm_dev_internal *dd =
 220		    list_entry(tmp, struct dm_dev_internal, list);
 221		DMWARN("%s: dm_table_destroy: dm_put_device call missing for %s",
 222		       dm_device_name(md), dd->dm_dev->name);
 223		dm_put_table_device(md, dd->dm_dev);
 224		kfree(dd);
 225	}
 226}
 227
 228void dm_table_destroy(struct dm_table *t)
 229{
 230	unsigned int i;
 231
 232	if (!t)
 233		return;
 234
 235	/* free the indexes */
 236	if (t->depth >= 2)
 237		vfree(t->index[t->depth - 2]);
 238
 239	/* free the targets */
 240	for (i = 0; i < t->num_targets; i++) {
 241		struct dm_target *tgt = t->targets + i;
 242
 243		if (tgt->type->dtr)
 244			tgt->type->dtr(tgt);
 245
 246		dm_put_target_type(tgt->type);
 247	}
 248
 249	vfree(t->highs);
 250
 251	/* free the device list */
 252	free_devices(&t->devices, t->md);
 253
 254	dm_free_md_mempools(t->mempools);
 255
 256	kfree(t);
 257}
 258
 259/*
 260 * See if we've already got a device in the list.
 261 */
 262static struct dm_dev_internal *find_device(struct list_head *l, dev_t dev)
 263{
 264	struct dm_dev_internal *dd;
 265
 266	list_for_each_entry (dd, l, list)
 267		if (dd->dm_dev->bdev->bd_dev == dev)
 268			return dd;
 269
 270	return NULL;
 271}
 272
 273/*
 274 * If possible, this checks an area of a destination device is invalid.
 275 */
 276static int device_area_is_invalid(struct dm_target *ti, struct dm_dev *dev,
 277				  sector_t start, sector_t len, void *data)
 278{
 
 279	struct queue_limits *limits = data;
 280	struct block_device *bdev = dev->bdev;
 281	sector_t dev_size =
 282		i_size_read(bdev->bd_inode) >> SECTOR_SHIFT;
 283	unsigned short logical_block_size_sectors =
 284		limits->logical_block_size >> SECTOR_SHIFT;
 285	char b[BDEVNAME_SIZE];
 286
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 287	if (!dev_size)
 288		return 0;
 289
 290	if ((start >= dev_size) || (start + len > dev_size)) {
 291		DMWARN("%s: %s too small for target: "
 292		       "start=%llu, len=%llu, dev_size=%llu",
 293		       dm_device_name(ti->table->md), bdevname(bdev, b),
 294		       (unsigned long long)start,
 295		       (unsigned long long)len,
 296		       (unsigned long long)dev_size);
 297		return 1;
 298	}
 299
 300	/*
 301	 * If the target is mapped to zoned block device(s), check
 302	 * that the zones are not partially mapped.
 303	 */
 304	if (bdev_zoned_model(bdev) != BLK_ZONED_NONE) {
 305		unsigned int zone_sectors = bdev_zone_sectors(bdev);
 306
 307		if (start & (zone_sectors - 1)) {
 308			DMWARN("%s: start=%llu not aligned to h/w zone size %u of %s",
 309			       dm_device_name(ti->table->md),
 310			       (unsigned long long)start,
 311			       zone_sectors, bdevname(bdev, b));
 312			return 1;
 313		}
 314
 315		/*
 316		 * Note: The last zone of a zoned block device may be smaller
 317		 * than other zones. So for a target mapping the end of a
 318		 * zoned block device with such a zone, len would not be zone
 319		 * aligned. We do not allow such last smaller zone to be part
 320		 * of the mapping here to ensure that mappings with multiple
 321		 * devices do not end up with a smaller zone in the middle of
 322		 * the sector range.
 323		 */
 324		if (len & (zone_sectors - 1)) {
 325			DMWARN("%s: len=%llu not aligned to h/w zone size %u of %s",
 326			       dm_device_name(ti->table->md),
 327			       (unsigned long long)len,
 328			       zone_sectors, bdevname(bdev, b));
 329			return 1;
 330		}
 331	}
 332
 333	if (logical_block_size_sectors <= 1)
 334		return 0;
 335
 336	if (start & (logical_block_size_sectors - 1)) {
 337		DMWARN("%s: start=%llu not aligned to h/w "
 338		       "logical block size %u of %s",
 339		       dm_device_name(ti->table->md),
 340		       (unsigned long long)start,
 341		       limits->logical_block_size, bdevname(bdev, b));
 342		return 1;
 343	}
 344
 345	if (len & (logical_block_size_sectors - 1)) {
 346		DMWARN("%s: len=%llu not aligned to h/w "
 347		       "logical block size %u of %s",
 348		       dm_device_name(ti->table->md),
 349		       (unsigned long long)len,
 350		       limits->logical_block_size, bdevname(bdev, b));
 351		return 1;
 352	}
 353
 354	return 0;
 355}
 356
 357/*
 358 * This upgrades the mode on an already open dm_dev, being
 359 * careful to leave things as they were if we fail to reopen the
 360 * device and not to touch the existing bdev field in case
 361 * it is accessed concurrently.
 362 */
 363static int upgrade_mode(struct dm_dev_internal *dd, fmode_t new_mode,
 364			struct mapped_device *md)
 365{
 366	int r;
 367	struct dm_dev *old_dev, *new_dev;
 368
 369	old_dev = dd->dm_dev;
 370
 371	r = dm_get_table_device(md, dd->dm_dev->bdev->bd_dev,
 372				dd->dm_dev->mode | new_mode, &new_dev);
 373	if (r)
 374		return r;
 375
 376	dd->dm_dev = new_dev;
 377	dm_put_table_device(md, old_dev);
 378
 379	return 0;
 380}
 381
 382/*
 383 * Convert the path to a device
 384 */
 385dev_t dm_get_dev_t(const char *path)
 386{
 387	dev_t dev;
 388	struct block_device *bdev;
 389
 390	bdev = lookup_bdev(path);
 391	if (IS_ERR(bdev))
 392		dev = name_to_dev_t(path);
 393	else {
 394		dev = bdev->bd_dev;
 395		bdput(bdev);
 396	}
 397
 398	return dev;
 399}
 400EXPORT_SYMBOL_GPL(dm_get_dev_t);
 401
 402/*
 403 * Add a device to the list, or just increment the usage count if
 404 * it's already present.
 405 */
 406int dm_get_device(struct dm_target *ti, const char *path, fmode_t mode,
 407		  struct dm_dev **result)
 408{
 409	int r;
 410	dev_t dev;
 411	struct dm_dev_internal *dd;
 412	struct dm_table *t = ti->table;
 413
 414	BUG_ON(!t);
 415
 416	dev = dm_get_dev_t(path);
 417	if (!dev)
 418		return -ENODEV;
 419
 420	dd = find_device(&t->devices, dev);
 421	if (!dd) {
 422		dd = kmalloc(sizeof(*dd), GFP_KERNEL);
 423		if (!dd)
 424			return -ENOMEM;
 425
 426		if ((r = dm_get_table_device(t->md, dev, mode, &dd->dm_dev))) {
 427			kfree(dd);
 428			return r;
 429		}
 430
 431		refcount_set(&dd->count, 1);
 432		list_add(&dd->list, &t->devices);
 433		goto out;
 434
 435	} else if (dd->dm_dev->mode != (mode | dd->dm_dev->mode)) {
 436		r = upgrade_mode(dd, mode, t->md);
 437		if (r)
 438			return r;
 439	}
 440	refcount_inc(&dd->count);
 441out:
 442	*result = dd->dm_dev;
 443	return 0;
 444}
 445EXPORT_SYMBOL(dm_get_device);
 446
 447static int dm_set_device_limits(struct dm_target *ti, struct dm_dev *dev,
 448				sector_t start, sector_t len, void *data)
 449{
 450	struct queue_limits *limits = data;
 451	struct block_device *bdev = dev->bdev;
 452	struct request_queue *q = bdev_get_queue(bdev);
 453	char b[BDEVNAME_SIZE];
 454
 455	if (unlikely(!q)) {
 456		DMWARN("%s: Cannot set limits for nonexistent device %s",
 457		       dm_device_name(ti->table->md), bdevname(bdev, b));
 458		return 0;
 459	}
 460
 461	if (blk_stack_limits(limits, &q->limits,
 462			get_start_sect(bdev) + start) < 0)
 463		DMWARN("%s: adding target device %s caused an alignment inconsistency: "
 464		       "physical_block_size=%u, logical_block_size=%u, "
 465		       "alignment_offset=%u, start=%llu",
 466		       dm_device_name(ti->table->md), bdevname(bdev, b),
 467		       q->limits.physical_block_size,
 468		       q->limits.logical_block_size,
 469		       q->limits.alignment_offset,
 470		       (unsigned long long) start << SECTOR_SHIFT);
 
 
 
 471	return 0;
 472}
 473
 474/*
 475 * Decrement a device's use count and remove it if necessary.
 476 */
 477void dm_put_device(struct dm_target *ti, struct dm_dev *d)
 478{
 479	int found = 0;
 480	struct list_head *devices = &ti->table->devices;
 481	struct dm_dev_internal *dd;
 482
 483	list_for_each_entry(dd, devices, list) {
 484		if (dd->dm_dev == d) {
 485			found = 1;
 486			break;
 487		}
 488	}
 489	if (!found) {
 490		DMWARN("%s: device %s not in table devices list",
 491		       dm_device_name(ti->table->md), d->name);
 492		return;
 493	}
 494	if (refcount_dec_and_test(&dd->count)) {
 495		dm_put_table_device(ti->table->md, d);
 496		list_del(&dd->list);
 497		kfree(dd);
 498	}
 499}
 500EXPORT_SYMBOL(dm_put_device);
 501
 502/*
 503 * Checks to see if the target joins onto the end of the table.
 504 */
 505static int adjoin(struct dm_table *table, struct dm_target *ti)
 506{
 507	struct dm_target *prev;
 508
 509	if (!table->num_targets)
 510		return !ti->begin;
 511
 512	prev = &table->targets[table->num_targets - 1];
 513	return (ti->begin == (prev->begin + prev->len));
 514}
 515
 516/*
 517 * Used to dynamically allocate the arg array.
 518 *
 519 * We do first allocation with GFP_NOIO because dm-mpath and dm-thin must
 520 * process messages even if some device is suspended. These messages have a
 521 * small fixed number of arguments.
 522 *
 523 * On the other hand, dm-switch needs to process bulk data using messages and
 524 * excessive use of GFP_NOIO could cause trouble.
 525 */
 526static char **realloc_argv(unsigned *size, char **old_argv)
 527{
 528	char **argv;
 529	unsigned new_size;
 530	gfp_t gfp;
 531
 532	if (*size) {
 533		new_size = *size * 2;
 534		gfp = GFP_KERNEL;
 535	} else {
 536		new_size = 8;
 537		gfp = GFP_NOIO;
 538	}
 539	argv = kmalloc_array(new_size, sizeof(*argv), gfp);
 540	if (argv && old_argv) {
 541		memcpy(argv, old_argv, *size * sizeof(*argv));
 542		*size = new_size;
 543	}
 544
 545	kfree(old_argv);
 546	return argv;
 547}
 548
 549/*
 550 * Destructively splits up the argument list to pass to ctr.
 551 */
 552int dm_split_args(int *argc, char ***argvp, char *input)
 553{
 554	char *start, *end = input, *out, **argv = NULL;
 555	unsigned array_size = 0;
 556
 557	*argc = 0;
 558
 559	if (!input) {
 560		*argvp = NULL;
 561		return 0;
 562	}
 563
 564	argv = realloc_argv(&array_size, argv);
 565	if (!argv)
 566		return -ENOMEM;
 567
 568	while (1) {
 569		/* Skip whitespace */
 570		start = skip_spaces(end);
 571
 572		if (!*start)
 573			break;	/* success, we hit the end */
 574
 575		/* 'out' is used to remove any back-quotes */
 576		end = out = start;
 577		while (*end) {
 578			/* Everything apart from '\0' can be quoted */
 579			if (*end == '\\' && *(end + 1)) {
 580				*out++ = *(end + 1);
 581				end += 2;
 582				continue;
 583			}
 584
 585			if (isspace(*end))
 586				break;	/* end of token */
 587
 588			*out++ = *end++;
 589		}
 590
 591		/* have we already filled the array ? */
 592		if ((*argc + 1) > array_size) {
 593			argv = realloc_argv(&array_size, argv);
 594			if (!argv)
 595				return -ENOMEM;
 596		}
 597
 598		/* we know this is whitespace */
 599		if (*end)
 600			end++;
 601
 602		/* terminate the string and put it in the array */
 603		*out = '\0';
 604		argv[*argc] = start;
 605		(*argc)++;
 606	}
 607
 608	*argvp = argv;
 609	return 0;
 610}
 611
 612/*
 613 * Impose necessary and sufficient conditions on a devices's table such
 614 * that any incoming bio which respects its logical_block_size can be
 615 * processed successfully.  If it falls across the boundary between
 616 * two or more targets, the size of each piece it gets split into must
 617 * be compatible with the logical_block_size of the target processing it.
 618 */
 619static int validate_hardware_logical_block_alignment(struct dm_table *table,
 620						 struct queue_limits *limits)
 621{
 622	/*
 623	 * This function uses arithmetic modulo the logical_block_size
 624	 * (in units of 512-byte sectors).
 625	 */
 626	unsigned short device_logical_block_size_sects =
 627		limits->logical_block_size >> SECTOR_SHIFT;
 628
 629	/*
 630	 * Offset of the start of the next table entry, mod logical_block_size.
 631	 */
 632	unsigned short next_target_start = 0;
 633
 634	/*
 635	 * Given an aligned bio that extends beyond the end of a
 636	 * target, how many sectors must the next target handle?
 637	 */
 638	unsigned short remaining = 0;
 639
 640	struct dm_target *ti;
 641	struct queue_limits ti_limits;
 642	unsigned i;
 643
 644	/*
 645	 * Check each entry in the table in turn.
 646	 */
 647	for (i = 0; i < dm_table_get_num_targets(table); i++) {
 648		ti = dm_table_get_target(table, i);
 649
 650		blk_set_stacking_limits(&ti_limits);
 651
 652		/* combine all target devices' limits */
 653		if (ti->type->iterate_devices)
 654			ti->type->iterate_devices(ti, dm_set_device_limits,
 655						  &ti_limits);
 656
 657		/*
 658		 * If the remaining sectors fall entirely within this
 659		 * table entry are they compatible with its logical_block_size?
 660		 */
 661		if (remaining < ti->len &&
 662		    remaining & ((ti_limits.logical_block_size >>
 663				  SECTOR_SHIFT) - 1))
 664			break;	/* Error */
 665
 666		next_target_start =
 667		    (unsigned short) ((next_target_start + ti->len) &
 668				      (device_logical_block_size_sects - 1));
 669		remaining = next_target_start ?
 670		    device_logical_block_size_sects - next_target_start : 0;
 671	}
 672
 673	if (remaining) {
 674		DMWARN("%s: table line %u (start sect %llu len %llu) "
 675		       "not aligned to h/w logical block size %u",
 676		       dm_device_name(table->md), i,
 677		       (unsigned long long) ti->begin,
 678		       (unsigned long long) ti->len,
 679		       limits->logical_block_size);
 680		return -EINVAL;
 681	}
 682
 683	return 0;
 684}
 685
 686int dm_table_add_target(struct dm_table *t, const char *type,
 687			sector_t start, sector_t len, char *params)
 688{
 689	int r = -EINVAL, argc;
 690	char **argv;
 691	struct dm_target *tgt;
 692
 693	if (t->singleton) {
 694		DMERR("%s: target type %s must appear alone in table",
 695		      dm_device_name(t->md), t->targets->type->name);
 696		return -EINVAL;
 697	}
 698
 699	BUG_ON(t->num_targets >= t->num_allocated);
 700
 701	tgt = t->targets + t->num_targets;
 702	memset(tgt, 0, sizeof(*tgt));
 703
 704	if (!len) {
 705		DMERR("%s: zero-length target", dm_device_name(t->md));
 706		return -EINVAL;
 707	}
 708
 709	tgt->type = dm_get_target_type(type);
 710	if (!tgt->type) {
 711		DMERR("%s: %s: unknown target type", dm_device_name(t->md), type);
 712		return -EINVAL;
 713	}
 714
 715	if (dm_target_needs_singleton(tgt->type)) {
 716		if (t->num_targets) {
 717			tgt->error = "singleton target type must appear alone in table";
 718			goto bad;
 719		}
 720		t->singleton = true;
 721	}
 722
 723	if (dm_target_always_writeable(tgt->type) && !(t->mode & FMODE_WRITE)) {
 724		tgt->error = "target type may not be included in a read-only table";
 725		goto bad;
 726	}
 727
 728	if (t->immutable_target_type) {
 729		if (t->immutable_target_type != tgt->type) {
 730			tgt->error = "immutable target type cannot be mixed with other target types";
 731			goto bad;
 732		}
 733	} else if (dm_target_is_immutable(tgt->type)) {
 734		if (t->num_targets) {
 735			tgt->error = "immutable target type cannot be mixed with other target types";
 736			goto bad;
 737		}
 738		t->immutable_target_type = tgt->type;
 739	}
 740
 741	if (dm_target_has_integrity(tgt->type))
 742		t->integrity_added = 1;
 743
 744	tgt->table = t;
 745	tgt->begin = start;
 746	tgt->len = len;
 747	tgt->error = "Unknown error";
 748
 749	/*
 750	 * Does this target adjoin the previous one ?
 751	 */
 752	if (!adjoin(t, tgt)) {
 753		tgt->error = "Gap in table";
 754		goto bad;
 755	}
 756
 757	r = dm_split_args(&argc, &argv, params);
 758	if (r) {
 759		tgt->error = "couldn't split parameters (insufficient memory)";
 760		goto bad;
 761	}
 762
 763	r = tgt->type->ctr(tgt, argc, argv);
 764	kfree(argv);
 765	if (r)
 766		goto bad;
 767
 768	t->highs[t->num_targets++] = tgt->begin + tgt->len - 1;
 769
 770	if (!tgt->num_discard_bios && tgt->discards_supported)
 771		DMWARN("%s: %s: ignoring discards_supported because num_discard_bios is zero.",
 772		       dm_device_name(t->md), type);
 773
 774	return 0;
 775
 776 bad:
 777	DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error);
 778	dm_put_target_type(tgt->type);
 779	return r;
 780}
 781
 782/*
 783 * Target argument parsing helpers.
 784 */
 785static int validate_next_arg(const struct dm_arg *arg,
 786			     struct dm_arg_set *arg_set,
 787			     unsigned *value, char **error, unsigned grouped)
 788{
 789	const char *arg_str = dm_shift_arg(arg_set);
 790	char dummy;
 791
 792	if (!arg_str ||
 793	    (sscanf(arg_str, "%u%c", value, &dummy) != 1) ||
 794	    (*value < arg->min) ||
 795	    (*value > arg->max) ||
 796	    (grouped && arg_set->argc < *value)) {
 797		*error = arg->error;
 798		return -EINVAL;
 799	}
 800
 801	return 0;
 802}
 803
 804int dm_read_arg(const struct dm_arg *arg, struct dm_arg_set *arg_set,
 805		unsigned *value, char **error)
 806{
 807	return validate_next_arg(arg, arg_set, value, error, 0);
 808}
 809EXPORT_SYMBOL(dm_read_arg);
 810
 811int dm_read_arg_group(const struct dm_arg *arg, struct dm_arg_set *arg_set,
 812		      unsigned *value, char **error)
 813{
 814	return validate_next_arg(arg, arg_set, value, error, 1);
 815}
 816EXPORT_SYMBOL(dm_read_arg_group);
 817
 818const char *dm_shift_arg(struct dm_arg_set *as)
 819{
 820	char *r;
 821
 822	if (as->argc) {
 823		as->argc--;
 824		r = *as->argv;
 825		as->argv++;
 826		return r;
 827	}
 828
 829	return NULL;
 830}
 831EXPORT_SYMBOL(dm_shift_arg);
 832
 833void dm_consume_args(struct dm_arg_set *as, unsigned num_args)
 834{
 835	BUG_ON(as->argc < num_args);
 836	as->argc -= num_args;
 837	as->argv += num_args;
 838}
 839EXPORT_SYMBOL(dm_consume_args);
 840
 841static bool __table_type_bio_based(enum dm_queue_mode table_type)
 842{
 843	return (table_type == DM_TYPE_BIO_BASED ||
 844		table_type == DM_TYPE_DAX_BIO_BASED ||
 845		table_type == DM_TYPE_NVME_BIO_BASED);
 846}
 847
 848static bool __table_type_request_based(enum dm_queue_mode table_type)
 849{
 850	return table_type == DM_TYPE_REQUEST_BASED;
 851}
 852
 853void dm_table_set_type(struct dm_table *t, enum dm_queue_mode type)
 854{
 855	t->type = type;
 856}
 857EXPORT_SYMBOL_GPL(dm_table_set_type);
 858
 859/* validate the dax capability of the target device span */
 860int device_supports_dax(struct dm_target *ti, struct dm_dev *dev,
 861			sector_t start, sector_t len, void *data)
 862{
 863	int blocksize = *(int *) data, id;
 864	bool rc;
 865
 866	id = dax_read_lock();
 867	rc = dax_supported(dev->dax_dev, dev->bdev, blocksize, start, len);
 868	dax_read_unlock(id);
 869
 870	return rc;
 
 871}
 872
 873/* Check devices support synchronous DAX */
 874static int device_dax_synchronous(struct dm_target *ti, struct dm_dev *dev,
 875				  sector_t start, sector_t len, void *data)
 876{
 877	return dev->dax_dev && dax_synchronous(dev->dax_dev);
 878}
 879
 880bool dm_table_supports_dax(struct dm_table *t,
 881			   iterate_devices_callout_fn iterate_fn, int *blocksize)
 882{
 883	struct dm_target *ti;
 884	unsigned i;
 885
 886	/* Ensure that all targets support DAX. */
 887	for (i = 0; i < dm_table_get_num_targets(t); i++) {
 888		ti = dm_table_get_target(t, i);
 889
 890		if (!ti->type->direct_access)
 891			return false;
 892
 893		if (!ti->type->iterate_devices ||
 894		    !ti->type->iterate_devices(ti, iterate_fn, blocksize))
 895			return false;
 896	}
 897
 898	return true;
 899}
 900
 901static bool dm_table_does_not_support_partial_completion(struct dm_table *t);
 902
 903static int device_is_rq_stackable(struct dm_target *ti, struct dm_dev *dev,
 904				  sector_t start, sector_t len, void *data)
 
 
 
 
 
 905{
 906	struct block_device *bdev = dev->bdev;
 907	struct request_queue *q = bdev_get_queue(bdev);
 908
 909	/* request-based cannot stack on partitions! */
 910	if (bdev != bdev->bd_contains)
 911		return false;
 
 912
 913	return queue_is_mq(q);
 914}
 915
 916static int dm_table_determine_type(struct dm_table *t)
 917{
 918	unsigned i;
 919	unsigned bio_based = 0, request_based = 0, hybrid = 0;
 
 920	struct dm_target *tgt;
 921	struct list_head *devices = dm_table_get_devices(t);
 922	enum dm_queue_mode live_md_type = dm_get_md_type(t->md);
 923	int page_size = PAGE_SIZE;
 924
 925	if (t->type != DM_TYPE_NONE) {
 926		/* target already set the table's type */
 927		if (t->type == DM_TYPE_BIO_BASED) {
 928			/* possibly upgrade to a variant of bio-based */
 929			goto verify_bio_based;
 930		}
 931		BUG_ON(t->type == DM_TYPE_DAX_BIO_BASED);
 932		BUG_ON(t->type == DM_TYPE_NVME_BIO_BASED);
 933		goto verify_rq_based;
 934	}
 935
 936	for (i = 0; i < t->num_targets; i++) {
 937		tgt = t->targets + i;
 938		if (dm_target_hybrid(tgt))
 939			hybrid = 1;
 940		else if (dm_target_request_based(tgt))
 941			request_based = 1;
 942		else
 943			bio_based = 1;
 944
 945		if (bio_based && request_based) {
 946			DMERR("Inconsistent table: different target types"
 947			      " can't be mixed up");
 948			return -EINVAL;
 949		}
 950	}
 951
 952	if (hybrid && !bio_based && !request_based) {
 953		/*
 954		 * The targets can work either way.
 955		 * Determine the type from the live device.
 956		 * Default to bio-based if device is new.
 957		 */
 958		if (__table_type_request_based(live_md_type))
 959			request_based = 1;
 960		else
 961			bio_based = 1;
 962	}
 963
 964	if (bio_based) {
 965verify_bio_based:
 966		/* We must use this table as bio-based */
 967		t->type = DM_TYPE_BIO_BASED;
 968		if (dm_table_supports_dax(t, device_supports_dax, &page_size) ||
 969		    (list_empty(devices) && live_md_type == DM_TYPE_DAX_BIO_BASED)) {
 970			t->type = DM_TYPE_DAX_BIO_BASED;
 971		} else {
 972			/* Check if upgrading to NVMe bio-based is valid or required */
 973			tgt = dm_table_get_immutable_target(t);
 974			if (tgt && !tgt->max_io_len && dm_table_does_not_support_partial_completion(t)) {
 975				t->type = DM_TYPE_NVME_BIO_BASED;
 976				goto verify_rq_based; /* must be stacked directly on NVMe (blk-mq) */
 977			} else if (list_empty(devices) && live_md_type == DM_TYPE_NVME_BIO_BASED) {
 978				t->type = DM_TYPE_NVME_BIO_BASED;
 979			}
 980		}
 981		return 0;
 982	}
 983
 984	BUG_ON(!request_based); /* No targets in this table */
 985
 986	t->type = DM_TYPE_REQUEST_BASED;
 987
 988verify_rq_based:
 989	/*
 990	 * Request-based dm supports only tables that have a single target now.
 991	 * To support multiple targets, request splitting support is needed,
 992	 * and that needs lots of changes in the block-layer.
 993	 * (e.g. request completion process for partial completion.)
 994	 */
 995	if (t->num_targets > 1) {
 996		DMERR("%s DM doesn't support multiple targets",
 997		      t->type == DM_TYPE_NVME_BIO_BASED ? "nvme bio-based" : "request-based");
 998		return -EINVAL;
 999	}
1000
1001	if (list_empty(devices)) {
1002		int srcu_idx;
1003		struct dm_table *live_table = dm_get_live_table(t->md, &srcu_idx);
1004
1005		/* inherit live table's type */
1006		if (live_table)
1007			t->type = live_table->type;
1008		dm_put_live_table(t->md, srcu_idx);
1009		return 0;
1010	}
1011
1012	tgt = dm_table_get_immutable_target(t);
1013	if (!tgt) {
1014		DMERR("table load rejected: immutable target is required");
1015		return -EINVAL;
1016	} else if (tgt->max_io_len) {
1017		DMERR("table load rejected: immutable target that splits IO is not supported");
1018		return -EINVAL;
1019	}
1020
1021	/* Non-request-stackable devices can't be used for request-based dm */
1022	if (!tgt->type->iterate_devices ||
1023	    !tgt->type->iterate_devices(tgt, device_is_rq_stackable, NULL)) {
1024		DMERR("table load rejected: including non-request-stackable devices");
1025		return -EINVAL;
1026	}
 
 
 
 
1027
1028	return 0;
1029}
1030
1031enum dm_queue_mode dm_table_get_type(struct dm_table *t)
1032{
1033	return t->type;
1034}
1035
1036struct target_type *dm_table_get_immutable_target_type(struct dm_table *t)
1037{
1038	return t->immutable_target_type;
1039}
1040
1041struct dm_target *dm_table_get_immutable_target(struct dm_table *t)
1042{
1043	/* Immutable target is implicitly a singleton */
1044	if (t->num_targets > 1 ||
1045	    !dm_target_is_immutable(t->targets[0].type))
1046		return NULL;
1047
1048	return t->targets;
1049}
1050
1051struct dm_target *dm_table_get_wildcard_target(struct dm_table *t)
1052{
1053	struct dm_target *ti;
1054	unsigned i;
1055
1056	for (i = 0; i < dm_table_get_num_targets(t); i++) {
1057		ti = dm_table_get_target(t, i);
1058		if (dm_target_is_wildcard(ti->type))
1059			return ti;
1060	}
1061
1062	return NULL;
1063}
1064
1065bool dm_table_bio_based(struct dm_table *t)
1066{
1067	return __table_type_bio_based(dm_table_get_type(t));
1068}
1069
1070bool dm_table_request_based(struct dm_table *t)
1071{
1072	return __table_type_request_based(dm_table_get_type(t));
1073}
1074
1075static int dm_table_alloc_md_mempools(struct dm_table *t, struct mapped_device *md)
1076{
1077	enum dm_queue_mode type = dm_table_get_type(t);
1078	unsigned per_io_data_size = 0;
1079	unsigned min_pool_size = 0;
1080	struct dm_target *ti;
1081	unsigned i;
1082
1083	if (unlikely(type == DM_TYPE_NONE)) {
1084		DMWARN("no table type is set, can't allocate mempools");
1085		return -EINVAL;
1086	}
1087
1088	if (__table_type_bio_based(type))
1089		for (i = 0; i < t->num_targets; i++) {
1090			ti = t->targets + i;
1091			per_io_data_size = max(per_io_data_size, ti->per_io_data_size);
1092			min_pool_size = max(min_pool_size, ti->num_flush_bios);
1093		}
1094
1095	t->mempools = dm_alloc_md_mempools(md, type, t->integrity_supported,
1096					   per_io_data_size, min_pool_size);
1097	if (!t->mempools)
1098		return -ENOMEM;
1099
1100	return 0;
1101}
1102
1103void dm_table_free_md_mempools(struct dm_table *t)
1104{
1105	dm_free_md_mempools(t->mempools);
1106	t->mempools = NULL;
1107}
1108
1109struct dm_md_mempools *dm_table_get_md_mempools(struct dm_table *t)
1110{
1111	return t->mempools;
1112}
1113
1114static int setup_indexes(struct dm_table *t)
1115{
1116	int i;
1117	unsigned int total = 0;
1118	sector_t *indexes;
1119
1120	/* allocate the space for *all* the indexes */
1121	for (i = t->depth - 2; i >= 0; i--) {
1122		t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE);
1123		total += t->counts[i];
1124	}
1125
1126	indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE);
1127	if (!indexes)
1128		return -ENOMEM;
1129
1130	/* set up internal nodes, bottom-up */
1131	for (i = t->depth - 2; i >= 0; i--) {
1132		t->index[i] = indexes;
1133		indexes += (KEYS_PER_NODE * t->counts[i]);
1134		setup_btree_index(i, t);
1135	}
1136
1137	return 0;
1138}
1139
1140/*
1141 * Builds the btree to index the map.
1142 */
1143static int dm_table_build_index(struct dm_table *t)
1144{
1145	int r = 0;
1146	unsigned int leaf_nodes;
1147
1148	/* how many indexes will the btree have ? */
1149	leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE);
1150	t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE);
1151
1152	/* leaf layer has already been set up */
1153	t->counts[t->depth - 1] = leaf_nodes;
1154	t->index[t->depth - 1] = t->highs;
1155
1156	if (t->depth >= 2)
1157		r = setup_indexes(t);
1158
1159	return r;
1160}
1161
1162static bool integrity_profile_exists(struct gendisk *disk)
1163{
1164	return !!blk_get_integrity(disk);
1165}
1166
1167/*
1168 * Get a disk whose integrity profile reflects the table's profile.
1169 * Returns NULL if integrity support was inconsistent or unavailable.
1170 */
1171static struct gendisk * dm_table_get_integrity_disk(struct dm_table *t)
1172{
1173	struct list_head *devices = dm_table_get_devices(t);
1174	struct dm_dev_internal *dd = NULL;
1175	struct gendisk *prev_disk = NULL, *template_disk = NULL;
1176	unsigned i;
1177
1178	for (i = 0; i < dm_table_get_num_targets(t); i++) {
1179		struct dm_target *ti = dm_table_get_target(t, i);
1180		if (!dm_target_passes_integrity(ti->type))
1181			goto no_integrity;
1182	}
1183
1184	list_for_each_entry(dd, devices, list) {
1185		template_disk = dd->dm_dev->bdev->bd_disk;
1186		if (!integrity_profile_exists(template_disk))
1187			goto no_integrity;
1188		else if (prev_disk &&
1189			 blk_integrity_compare(prev_disk, template_disk) < 0)
1190			goto no_integrity;
1191		prev_disk = template_disk;
1192	}
1193
1194	return template_disk;
1195
1196no_integrity:
1197	if (prev_disk)
1198		DMWARN("%s: integrity not set: %s and %s profile mismatch",
1199		       dm_device_name(t->md),
1200		       prev_disk->disk_name,
1201		       template_disk->disk_name);
1202	return NULL;
1203}
1204
1205/*
1206 * Register the mapped device for blk_integrity support if the
1207 * underlying devices have an integrity profile.  But all devices may
1208 * not have matching profiles (checking all devices isn't reliable
1209 * during table load because this table may use other DM device(s) which
1210 * must be resumed before they will have an initialized integity
1211 * profile).  Consequently, stacked DM devices force a 2 stage integrity
1212 * profile validation: First pass during table load, final pass during
1213 * resume.
1214 */
1215static int dm_table_register_integrity(struct dm_table *t)
1216{
1217	struct mapped_device *md = t->md;
1218	struct gendisk *template_disk = NULL;
1219
1220	/* If target handles integrity itself do not register it here. */
1221	if (t->integrity_added)
1222		return 0;
1223
1224	template_disk = dm_table_get_integrity_disk(t);
1225	if (!template_disk)
1226		return 0;
1227
1228	if (!integrity_profile_exists(dm_disk(md))) {
1229		t->integrity_supported = true;
1230		/*
1231		 * Register integrity profile during table load; we can do
1232		 * this because the final profile must match during resume.
1233		 */
1234		blk_integrity_register(dm_disk(md),
1235				       blk_get_integrity(template_disk));
1236		return 0;
1237	}
1238
1239	/*
1240	 * If DM device already has an initialized integrity
1241	 * profile the new profile should not conflict.
1242	 */
1243	if (blk_integrity_compare(dm_disk(md), template_disk) < 0) {
1244		DMWARN("%s: conflict with existing integrity profile: "
1245		       "%s profile mismatch",
1246		       dm_device_name(t->md),
1247		       template_disk->disk_name);
1248		return 1;
1249	}
1250
1251	/* Preserve existing integrity profile */
1252	t->integrity_supported = true;
1253	return 0;
1254}
1255
1256/*
1257 * Prepares the table for use by building the indices,
1258 * setting the type, and allocating mempools.
1259 */
1260int dm_table_complete(struct dm_table *t)
1261{
1262	int r;
1263
1264	r = dm_table_determine_type(t);
1265	if (r) {
1266		DMERR("unable to determine table type");
1267		return r;
1268	}
1269
1270	r = dm_table_build_index(t);
1271	if (r) {
1272		DMERR("unable to build btrees");
1273		return r;
1274	}
1275
1276	r = dm_table_register_integrity(t);
1277	if (r) {
1278		DMERR("could not register integrity profile.");
1279		return r;
1280	}
1281
1282	r = dm_table_alloc_md_mempools(t, t->md);
1283	if (r)
1284		DMERR("unable to allocate mempools");
1285
1286	return r;
1287}
1288
1289static DEFINE_MUTEX(_event_lock);
1290void dm_table_event_callback(struct dm_table *t,
1291			     void (*fn)(void *), void *context)
1292{
1293	mutex_lock(&_event_lock);
1294	t->event_fn = fn;
1295	t->event_context = context;
1296	mutex_unlock(&_event_lock);
1297}
1298
1299void dm_table_event(struct dm_table *t)
1300{
1301	/*
1302	 * You can no longer call dm_table_event() from interrupt
1303	 * context, use a bottom half instead.
1304	 */
1305	BUG_ON(in_interrupt());
1306
1307	mutex_lock(&_event_lock);
1308	if (t->event_fn)
1309		t->event_fn(t->event_context);
1310	mutex_unlock(&_event_lock);
1311}
1312EXPORT_SYMBOL(dm_table_event);
1313
1314inline sector_t dm_table_get_size(struct dm_table *t)
1315{
1316	return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0;
1317}
1318EXPORT_SYMBOL(dm_table_get_size);
1319
1320struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index)
1321{
1322	if (index >= t->num_targets)
1323		return NULL;
1324
1325	return t->targets + index;
1326}
1327
1328/*
1329 * Search the btree for the correct target.
1330 *
1331 * Caller should check returned pointer for NULL
1332 * to trap I/O beyond end of device.
1333 */
1334struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector)
1335{
1336	unsigned int l, n = 0, k = 0;
1337	sector_t *node;
1338
1339	if (unlikely(sector >= dm_table_get_size(t)))
1340		return NULL;
1341
1342	for (l = 0; l < t->depth; l++) {
1343		n = get_child(n, k);
1344		node = get_node(t, l, n);
1345
1346		for (k = 0; k < KEYS_PER_NODE; k++)
1347			if (node[k] >= sector)
1348				break;
1349	}
1350
1351	return &t->targets[(KEYS_PER_NODE * n) + k];
1352}
1353
1354static int count_device(struct dm_target *ti, struct dm_dev *dev,
1355			sector_t start, sector_t len, void *data)
1356{
1357	unsigned *num_devices = data;
1358
1359	(*num_devices)++;
1360
1361	return 0;
1362}
1363
1364/*
1365 * Check whether a table has no data devices attached using each
1366 * target's iterate_devices method.
1367 * Returns false if the result is unknown because a target doesn't
1368 * support iterate_devices.
1369 */
1370bool dm_table_has_no_data_devices(struct dm_table *table)
1371{
1372	struct dm_target *ti;
1373	unsigned i, num_devices;
1374
1375	for (i = 0; i < dm_table_get_num_targets(table); i++) {
1376		ti = dm_table_get_target(table, i);
1377
1378		if (!ti->type->iterate_devices)
1379			return false;
1380
1381		num_devices = 0;
1382		ti->type->iterate_devices(ti, count_device, &num_devices);
1383		if (num_devices)
1384			return false;
1385	}
1386
1387	return true;
1388}
1389
1390static int device_is_zoned_model(struct dm_target *ti, struct dm_dev *dev,
1391				 sector_t start, sector_t len, void *data)
1392{
1393	struct request_queue *q = bdev_get_queue(dev->bdev);
1394	enum blk_zoned_model *zoned_model = data;
1395
1396	return q && blk_queue_zoned_model(q) == *zoned_model;
1397}
1398
1399static bool dm_table_supports_zoned_model(struct dm_table *t,
1400					  enum blk_zoned_model zoned_model)
1401{
1402	struct dm_target *ti;
1403	unsigned i;
1404
1405	for (i = 0; i < dm_table_get_num_targets(t); i++) {
1406		ti = dm_table_get_target(t, i);
1407
1408		if (zoned_model == BLK_ZONED_HM &&
1409		    !dm_target_supports_zoned_hm(ti->type))
1410			return false;
1411
1412		if (!ti->type->iterate_devices ||
1413		    !ti->type->iterate_devices(ti, device_is_zoned_model, &zoned_model))
1414			return false;
1415	}
1416
1417	return true;
1418}
1419
1420static int device_matches_zone_sectors(struct dm_target *ti, struct dm_dev *dev,
1421				       sector_t start, sector_t len, void *data)
1422{
1423	struct request_queue *q = bdev_get_queue(dev->bdev);
1424	unsigned int *zone_sectors = data;
1425
1426	return q && blk_queue_zone_sectors(q) == *zone_sectors;
1427}
1428
1429static bool dm_table_matches_zone_sectors(struct dm_table *t,
1430					  unsigned int zone_sectors)
1431{
1432	struct dm_target *ti;
1433	unsigned i;
1434
1435	for (i = 0; i < dm_table_get_num_targets(t); i++) {
1436		ti = dm_table_get_target(t, i);
1437
1438		if (!ti->type->iterate_devices ||
1439		    !ti->type->iterate_devices(ti, device_matches_zone_sectors, &zone_sectors))
1440			return false;
1441	}
1442
1443	return true;
1444}
1445
1446static int validate_hardware_zoned_model(struct dm_table *table,
1447					 enum blk_zoned_model zoned_model,
1448					 unsigned int zone_sectors)
1449{
1450	if (zoned_model == BLK_ZONED_NONE)
1451		return 0;
1452
1453	if (!dm_table_supports_zoned_model(table, zoned_model)) {
1454		DMERR("%s: zoned model is not consistent across all devices",
1455		      dm_device_name(table->md));
1456		return -EINVAL;
1457	}
1458
1459	/* Check zone size validity and compatibility */
1460	if (!zone_sectors || !is_power_of_2(zone_sectors))
1461		return -EINVAL;
1462
1463	if (!dm_table_matches_zone_sectors(table, zone_sectors)) {
1464		DMERR("%s: zone sectors is not consistent across all devices",
1465		      dm_device_name(table->md));
1466		return -EINVAL;
1467	}
1468
1469	return 0;
1470}
1471
1472/*
1473 * Establish the new table's queue_limits and validate them.
1474 */
1475int dm_calculate_queue_limits(struct dm_table *table,
1476			      struct queue_limits *limits)
1477{
1478	struct dm_target *ti;
1479	struct queue_limits ti_limits;
1480	unsigned i;
1481	enum blk_zoned_model zoned_model = BLK_ZONED_NONE;
1482	unsigned int zone_sectors = 0;
1483
1484	blk_set_stacking_limits(limits);
1485
1486	for (i = 0; i < dm_table_get_num_targets(table); i++) {
1487		blk_set_stacking_limits(&ti_limits);
1488
1489		ti = dm_table_get_target(table, i);
1490
1491		if (!ti->type->iterate_devices)
1492			goto combine_limits;
1493
1494		/*
1495		 * Combine queue limits of all the devices this target uses.
1496		 */
1497		ti->type->iterate_devices(ti, dm_set_device_limits,
1498					  &ti_limits);
1499
1500		if (zoned_model == BLK_ZONED_NONE && ti_limits.zoned != BLK_ZONED_NONE) {
1501			/*
1502			 * After stacking all limits, validate all devices
1503			 * in table support this zoned model and zone sectors.
1504			 */
1505			zoned_model = ti_limits.zoned;
1506			zone_sectors = ti_limits.chunk_sectors;
1507		}
1508
1509		/* Set I/O hints portion of queue limits */
1510		if (ti->type->io_hints)
1511			ti->type->io_hints(ti, &ti_limits);
1512
1513		/*
1514		 * Check each device area is consistent with the target's
1515		 * overall queue limits.
1516		 */
1517		if (ti->type->iterate_devices(ti, device_area_is_invalid,
1518					      &ti_limits))
1519			return -EINVAL;
1520
1521combine_limits:
1522		/*
1523		 * Merge this target's queue limits into the overall limits
1524		 * for the table.
1525		 */
1526		if (blk_stack_limits(limits, &ti_limits, 0) < 0)
1527			DMWARN("%s: adding target device "
1528			       "(start sect %llu len %llu) "
1529			       "caused an alignment inconsistency",
1530			       dm_device_name(table->md),
1531			       (unsigned long long) ti->begin,
1532			       (unsigned long long) ti->len);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1533	}
1534
1535	/*
1536	 * Verify that the zoned model and zone sectors, as determined before
1537	 * any .io_hints override, are the same across all devices in the table.
1538	 * - this is especially relevant if .io_hints is emulating a disk-managed
1539	 *   zoned model (aka BLK_ZONED_NONE) on host-managed zoned block devices.
1540	 * BUT...
1541	 */
1542	if (limits->zoned != BLK_ZONED_NONE) {
1543		/*
1544		 * ...IF the above limits stacking determined a zoned model
1545		 * validate that all of the table's devices conform to it.
1546		 */
1547		zoned_model = limits->zoned;
1548		zone_sectors = limits->chunk_sectors;
1549	}
1550	if (validate_hardware_zoned_model(table, zoned_model, zone_sectors))
1551		return -EINVAL;
1552
1553	return validate_hardware_logical_block_alignment(table, limits);
1554}
1555
1556/*
1557 * Verify that all devices have an integrity profile that matches the
1558 * DM device's registered integrity profile.  If the profiles don't
1559 * match then unregister the DM device's integrity profile.
1560 */
1561static void dm_table_verify_integrity(struct dm_table *t)
1562{
1563	struct gendisk *template_disk = NULL;
1564
1565	if (t->integrity_added)
1566		return;
1567
1568	if (t->integrity_supported) {
1569		/*
1570		 * Verify that the original integrity profile
1571		 * matches all the devices in this table.
1572		 */
1573		template_disk = dm_table_get_integrity_disk(t);
1574		if (template_disk &&
1575		    blk_integrity_compare(dm_disk(t->md), template_disk) >= 0)
1576			return;
1577	}
1578
1579	if (integrity_profile_exists(dm_disk(t->md))) {
1580		DMWARN("%s: unable to establish an integrity profile",
1581		       dm_device_name(t->md));
1582		blk_integrity_unregister(dm_disk(t->md));
1583	}
1584}
1585
1586static int device_flush_capable(struct dm_target *ti, struct dm_dev *dev,
1587				sector_t start, sector_t len, void *data)
1588{
1589	unsigned long flush = (unsigned long) data;
1590	struct request_queue *q = bdev_get_queue(dev->bdev);
1591
1592	return q && (q->queue_flags & flush);
1593}
1594
1595static bool dm_table_supports_flush(struct dm_table *t, unsigned long flush)
1596{
1597	struct dm_target *ti;
1598	unsigned i;
1599
1600	/*
1601	 * Require at least one underlying device to support flushes.
1602	 * t->devices includes internal dm devices such as mirror logs
1603	 * so we need to use iterate_devices here, which targets
1604	 * supporting flushes must provide.
1605	 */
1606	for (i = 0; i < dm_table_get_num_targets(t); i++) {
1607		ti = dm_table_get_target(t, i);
1608
1609		if (!ti->num_flush_bios)
1610			continue;
1611
1612		if (ti->flush_supported)
1613			return true;
1614
1615		if (ti->type->iterate_devices &&
1616		    ti->type->iterate_devices(ti, device_flush_capable, (void *) flush))
1617			return true;
1618	}
1619
1620	return false;
1621}
1622
1623static int device_dax_write_cache_enabled(struct dm_target *ti,
1624					  struct dm_dev *dev, sector_t start,
1625					  sector_t len, void *data)
1626{
1627	struct dax_device *dax_dev = dev->dax_dev;
1628
1629	if (!dax_dev)
1630		return false;
1631
1632	if (dax_write_cache_enabled(dax_dev))
1633		return true;
1634	return false;
1635}
1636
1637static int dm_table_supports_dax_write_cache(struct dm_table *t)
1638{
1639	struct dm_target *ti;
1640	unsigned i;
1641
1642	for (i = 0; i < dm_table_get_num_targets(t); i++) {
1643		ti = dm_table_get_target(t, i);
1644
1645		if (ti->type->iterate_devices &&
1646		    ti->type->iterate_devices(ti,
1647				device_dax_write_cache_enabled, NULL))
1648			return true;
1649	}
1650
1651	return false;
1652}
1653
1654static int device_is_nonrot(struct dm_target *ti, struct dm_dev *dev,
1655			    sector_t start, sector_t len, void *data)
1656{
1657	struct request_queue *q = bdev_get_queue(dev->bdev);
1658
1659	return q && blk_queue_nonrot(q);
1660}
1661
1662static int device_is_not_random(struct dm_target *ti, struct dm_dev *dev,
1663			     sector_t start, sector_t len, void *data)
1664{
1665	struct request_queue *q = bdev_get_queue(dev->bdev);
1666
1667	return q && !blk_queue_add_random(q);
1668}
1669
1670static bool dm_table_all_devices_attribute(struct dm_table *t,
1671					   iterate_devices_callout_fn func)
1672{
1673	struct dm_target *ti;
1674	unsigned i;
1675
1676	for (i = 0; i < dm_table_get_num_targets(t); i++) {
1677		ti = dm_table_get_target(t, i);
1678
1679		if (!ti->type->iterate_devices ||
1680		    !ti->type->iterate_devices(ti, func, NULL))
1681			return false;
1682	}
1683
1684	return true;
1685}
1686
1687static int device_no_partial_completion(struct dm_target *ti, struct dm_dev *dev,
1688					sector_t start, sector_t len, void *data)
1689{
1690	char b[BDEVNAME_SIZE];
1691
1692	/* For now, NVMe devices are the only devices of this class */
1693	return (strncmp(bdevname(dev->bdev, b), "nvme", 4) == 0);
1694}
1695
1696static bool dm_table_does_not_support_partial_completion(struct dm_table *t)
1697{
1698	return dm_table_all_devices_attribute(t, device_no_partial_completion);
1699}
1700
1701static int device_not_write_same_capable(struct dm_target *ti, struct dm_dev *dev,
1702					 sector_t start, sector_t len, void *data)
1703{
1704	struct request_queue *q = bdev_get_queue(dev->bdev);
1705
1706	return q && !q->limits.max_write_same_sectors;
1707}
1708
1709static bool dm_table_supports_write_same(struct dm_table *t)
1710{
1711	struct dm_target *ti;
1712	unsigned i;
1713
1714	for (i = 0; i < dm_table_get_num_targets(t); i++) {
1715		ti = dm_table_get_target(t, i);
1716
1717		if (!ti->num_write_same_bios)
1718			return false;
1719
1720		if (!ti->type->iterate_devices ||
1721		    ti->type->iterate_devices(ti, device_not_write_same_capable, NULL))
1722			return false;
1723	}
1724
1725	return true;
1726}
1727
1728static int device_not_write_zeroes_capable(struct dm_target *ti, struct dm_dev *dev,
1729					   sector_t start, sector_t len, void *data)
1730{
1731	struct request_queue *q = bdev_get_queue(dev->bdev);
1732
1733	return q && !q->limits.max_write_zeroes_sectors;
1734}
1735
1736static bool dm_table_supports_write_zeroes(struct dm_table *t)
1737{
1738	struct dm_target *ti;
1739	unsigned i = 0;
1740
1741	while (i < dm_table_get_num_targets(t)) {
1742		ti = dm_table_get_target(t, i++);
1743
1744		if (!ti->num_write_zeroes_bios)
1745			return false;
1746
1747		if (!ti->type->iterate_devices ||
1748		    ti->type->iterate_devices(ti, device_not_write_zeroes_capable, NULL))
1749			return false;
1750	}
1751
1752	return true;
1753}
1754
1755static int device_not_discard_capable(struct dm_target *ti, struct dm_dev *dev,
1756				      sector_t start, sector_t len, void *data)
1757{
1758	struct request_queue *q = bdev_get_queue(dev->bdev);
1759
1760	return q && !blk_queue_discard(q);
1761}
1762
1763static bool dm_table_supports_discards(struct dm_table *t)
1764{
1765	struct dm_target *ti;
1766	unsigned i;
1767
1768	for (i = 0; i < dm_table_get_num_targets(t); i++) {
1769		ti = dm_table_get_target(t, i);
1770
1771		if (!ti->num_discard_bios)
1772			return false;
1773
1774		/*
1775		 * Either the target provides discard support (as implied by setting
1776		 * 'discards_supported') or it relies on _all_ data devices having
1777		 * discard support.
1778		 */
1779		if (!ti->discards_supported &&
1780		    (!ti->type->iterate_devices ||
1781		     ti->type->iterate_devices(ti, device_not_discard_capable, NULL)))
1782			return false;
1783	}
1784
1785	return true;
1786}
1787
1788static int device_not_secure_erase_capable(struct dm_target *ti,
1789					   struct dm_dev *dev, sector_t start,
1790					   sector_t len, void *data)
1791{
1792	struct request_queue *q = bdev_get_queue(dev->bdev);
1793
1794	return q && !blk_queue_secure_erase(q);
1795}
1796
1797static bool dm_table_supports_secure_erase(struct dm_table *t)
1798{
1799	struct dm_target *ti;
1800	unsigned int i;
1801
1802	for (i = 0; i < dm_table_get_num_targets(t); i++) {
1803		ti = dm_table_get_target(t, i);
1804
1805		if (!ti->num_secure_erase_bios)
1806			return false;
1807
1808		if (!ti->type->iterate_devices ||
1809		    ti->type->iterate_devices(ti, device_not_secure_erase_capable, NULL))
1810			return false;
1811	}
1812
1813	return true;
1814}
1815
1816static int device_requires_stable_pages(struct dm_target *ti,
1817					struct dm_dev *dev, sector_t start,
1818					sector_t len, void *data)
1819{
1820	struct request_queue *q = bdev_get_queue(dev->bdev);
1821
1822	return q && bdi_cap_stable_pages_required(q->backing_dev_info);
1823}
1824
1825/*
1826 * If any underlying device requires stable pages, a table must require
1827 * them as well.  Only targets that support iterate_devices are considered:
1828 * don't want error, zero, etc to require stable pages.
1829 */
1830static bool dm_table_requires_stable_pages(struct dm_table *t)
1831{
1832	struct dm_target *ti;
1833	unsigned i;
1834
1835	for (i = 0; i < dm_table_get_num_targets(t); i++) {
1836		ti = dm_table_get_target(t, i);
1837
1838		if (ti->type->iterate_devices &&
1839		    ti->type->iterate_devices(ti, device_requires_stable_pages, NULL))
1840			return true;
1841	}
1842
1843	return false;
1844}
1845
1846void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q,
1847			       struct queue_limits *limits)
1848{
1849	bool wc = false, fua = false;
1850	int page_size = PAGE_SIZE;
1851
1852	/*
1853	 * Copy table's limits to the DM device's request_queue
1854	 */
1855	q->limits = *limits;
1856
1857	if (!dm_table_supports_discards(t)) {
1858		blk_queue_flag_clear(QUEUE_FLAG_DISCARD, q);
1859		/* Must also clear discard limits... */
1860		q->limits.max_discard_sectors = 0;
1861		q->limits.max_hw_discard_sectors = 0;
1862		q->limits.discard_granularity = 0;
1863		q->limits.discard_alignment = 0;
1864		q->limits.discard_misaligned = 0;
1865	} else
1866		blk_queue_flag_set(QUEUE_FLAG_DISCARD, q);
1867
1868	if (dm_table_supports_secure_erase(t))
1869		blk_queue_flag_set(QUEUE_FLAG_SECERASE, q);
1870
1871	if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_WC))) {
1872		wc = true;
1873		if (dm_table_supports_flush(t, (1UL << QUEUE_FLAG_FUA)))
1874			fua = true;
1875	}
1876	blk_queue_write_cache(q, wc, fua);
1877
1878	if (dm_table_supports_dax(t, device_supports_dax, &page_size)) {
1879		blk_queue_flag_set(QUEUE_FLAG_DAX, q);
1880		if (dm_table_supports_dax(t, device_dax_synchronous, NULL))
1881			set_dax_synchronous(t->md->dax_dev);
1882	}
1883	else
1884		blk_queue_flag_clear(QUEUE_FLAG_DAX, q);
1885
1886	if (dm_table_supports_dax_write_cache(t))
1887		dax_write_cache(t->md->dax_dev, true);
1888
1889	/* Ensure that all underlying devices are non-rotational. */
1890	if (dm_table_all_devices_attribute(t, device_is_nonrot))
1891		blk_queue_flag_set(QUEUE_FLAG_NONROT, q);
1892	else
1893		blk_queue_flag_clear(QUEUE_FLAG_NONROT, q);
1894
1895	if (!dm_table_supports_write_same(t))
1896		q->limits.max_write_same_sectors = 0;
1897	if (!dm_table_supports_write_zeroes(t))
1898		q->limits.max_write_zeroes_sectors = 0;
1899
1900	dm_table_verify_integrity(t);
1901
1902	/*
1903	 * Some devices don't use blk_integrity but still want stable pages
1904	 * because they do their own checksumming.
1905	 */
1906	if (dm_table_requires_stable_pages(t))
1907		q->backing_dev_info->capabilities |= BDI_CAP_STABLE_WRITES;
1908	else
1909		q->backing_dev_info->capabilities &= ~BDI_CAP_STABLE_WRITES;
1910
1911	/*
1912	 * Determine whether or not this queue's I/O timings contribute
1913	 * to the entropy pool, Only request-based targets use this.
1914	 * Clear QUEUE_FLAG_ADD_RANDOM if any underlying device does not
1915	 * have it set.
1916	 */
1917	if (blk_queue_add_random(q) && dm_table_all_devices_attribute(t, device_is_not_random))
1918		blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, q);
1919
1920	/*
1921	 * For a zoned target, the number of zones should be updated for the
1922	 * correct value to be exposed in sysfs queue/nr_zones. For a BIO based
1923	 * target, this is all that is needed.
 
 
1924	 */
1925#ifdef CONFIG_BLK_DEV_ZONED
1926	if (blk_queue_is_zoned(q)) {
1927		WARN_ON_ONCE(queue_is_mq(q));
1928		q->nr_zones = blkdev_nr_zones(t->md->disk);
1929	}
1930#endif
1931
1932	/* Allow reads to exceed readahead limits */
1933	q->backing_dev_info->io_pages = limits->max_sectors >> (PAGE_SHIFT - 9);
1934}
1935
1936unsigned int dm_table_get_num_targets(struct dm_table *t)
1937{
1938	return t->num_targets;
1939}
1940
1941struct list_head *dm_table_get_devices(struct dm_table *t)
1942{
1943	return &t->devices;
1944}
1945
1946fmode_t dm_table_get_mode(struct dm_table *t)
1947{
1948	return t->mode;
1949}
1950EXPORT_SYMBOL(dm_table_get_mode);
1951
1952enum suspend_mode {
1953	PRESUSPEND,
1954	PRESUSPEND_UNDO,
1955	POSTSUSPEND,
1956};
1957
1958static void suspend_targets(struct dm_table *t, enum suspend_mode mode)
1959{
1960	int i = t->num_targets;
1961	struct dm_target *ti = t->targets;
1962
1963	lockdep_assert_held(&t->md->suspend_lock);
1964
1965	while (i--) {
1966		switch (mode) {
1967		case PRESUSPEND:
1968			if (ti->type->presuspend)
1969				ti->type->presuspend(ti);
1970			break;
1971		case PRESUSPEND_UNDO:
1972			if (ti->type->presuspend_undo)
1973				ti->type->presuspend_undo(ti);
1974			break;
1975		case POSTSUSPEND:
1976			if (ti->type->postsuspend)
1977				ti->type->postsuspend(ti);
1978			break;
1979		}
1980		ti++;
1981	}
1982}
1983
1984void dm_table_presuspend_targets(struct dm_table *t)
1985{
1986	if (!t)
1987		return;
1988
1989	suspend_targets(t, PRESUSPEND);
1990}
1991
1992void dm_table_presuspend_undo_targets(struct dm_table *t)
1993{
1994	if (!t)
1995		return;
1996
1997	suspend_targets(t, PRESUSPEND_UNDO);
1998}
1999
2000void dm_table_postsuspend_targets(struct dm_table *t)
2001{
2002	if (!t)
2003		return;
2004
2005	suspend_targets(t, POSTSUSPEND);
2006}
2007
2008int dm_table_resume_targets(struct dm_table *t)
2009{
2010	int i, r = 0;
2011
2012	lockdep_assert_held(&t->md->suspend_lock);
2013
2014	for (i = 0; i < t->num_targets; i++) {
2015		struct dm_target *ti = t->targets + i;
2016
2017		if (!ti->type->preresume)
2018			continue;
2019
2020		r = ti->type->preresume(ti);
2021		if (r) {
2022			DMERR("%s: %s: preresume failed, error = %d",
2023			      dm_device_name(t->md), ti->type->name, r);
2024			return r;
2025		}
2026	}
2027
2028	for (i = 0; i < t->num_targets; i++) {
2029		struct dm_target *ti = t->targets + i;
2030
2031		if (ti->type->resume)
2032			ti->type->resume(ti);
2033	}
2034
2035	return 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2036}
2037
2038struct mapped_device *dm_table_get_md(struct dm_table *t)
2039{
2040	return t->md;
2041}
2042EXPORT_SYMBOL(dm_table_get_md);
2043
2044const char *dm_table_device_name(struct dm_table *t)
2045{
2046	return dm_device_name(t->md);
2047}
2048EXPORT_SYMBOL_GPL(dm_table_device_name);
2049
2050void dm_table_run_md_queue_async(struct dm_table *t)
2051{
2052	struct mapped_device *md;
2053	struct request_queue *queue;
2054
2055	if (!dm_table_request_based(t))
2056		return;
2057
2058	md = dm_table_get_md(t);
2059	queue = dm_get_md_queue(md);
2060	if (queue)
2061		blk_mq_run_hw_queues(queue, true);
2062}
2063EXPORT_SYMBOL(dm_table_run_md_queue_async);
2064