dm-ioctl.c 37.2 KB
Newer Older
L
Linus Torvalds 已提交
1 2
/*
 * Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
3
 * Copyright (C) 2004 - 2006 Red Hat, Inc. All rights reserved.
L
Linus Torvalds 已提交
4 5 6 7 8 9 10 11 12 13 14 15 16
 *
 * This file is released under the GPL.
 */

#include "dm.h"

#include <linux/module.h>
#include <linux/vmalloc.h>
#include <linux/miscdevice.h>
#include <linux/init.h>
#include <linux/wait.h>
#include <linux/slab.h>
#include <linux/dm-ioctl.h>
D
Darrick J. Wong 已提交
17
#include <linux/hdreg.h>
M
Milan Broz 已提交
18
#include <linux/compat.h>
L
Linus Torvalds 已提交
19 20 21

#include <asm/uaccess.h>

22
#define DM_MSG_PREFIX "ioctl"
L
Linus Torvalds 已提交
23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51
#define DM_DRIVER_EMAIL "dm-devel@redhat.com"

/*-----------------------------------------------------------------
 * The ioctl interface needs to be able to look up devices by
 * name or uuid.
 *---------------------------------------------------------------*/
struct hash_cell {
	struct list_head name_list;
	struct list_head uuid_list;

	char *name;
	char *uuid;
	struct mapped_device *md;
	struct dm_table *new_map;
};

struct vers_iter {
    size_t param_size;
    struct dm_target_versions *vers, *old_vers;
    char *end;
    uint32_t flags;
};


#define NUM_BUCKETS 64
#define MASK_BUCKETS (NUM_BUCKETS - 1)
static struct list_head _name_buckets[NUM_BUCKETS];
static struct list_head _uuid_buckets[NUM_BUCKETS];

52
static void dm_hash_remove_all(int keep_open_devices);
L
Linus Torvalds 已提交
53 54 55 56 57 58

/*
 * Guards access to both hash tables.
 */
static DECLARE_RWSEM(_hash_lock);

M
Mikulas Patocka 已提交
59 60 61 62 63
/*
 * Protects use of mdptr to obtain hash cell name and uuid from mapped device.
 */
static DEFINE_MUTEX(dm_hash_cells_mutex);

L
Linus Torvalds 已提交
64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80
static void init_buckets(struct list_head *buckets)
{
	unsigned int i;

	for (i = 0; i < NUM_BUCKETS; i++)
		INIT_LIST_HEAD(buckets + i);
}

static int dm_hash_init(void)
{
	init_buckets(_name_buckets);
	init_buckets(_uuid_buckets);
	return 0;
}

static void dm_hash_exit(void)
{
81
	dm_hash_remove_all(0);
L
Linus Torvalds 已提交
82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108
}

/*-----------------------------------------------------------------
 * Hash function:
 * We're not really concerned with the str hash function being
 * fast since it's only used by the ioctl interface.
 *---------------------------------------------------------------*/
static unsigned int hash_str(const char *str)
{
	const unsigned int hash_mult = 2654435387U;
	unsigned int h = 0;

	while (*str)
		h = (h + (unsigned int) *str++) * hash_mult;

	return h & MASK_BUCKETS;
}

/*-----------------------------------------------------------------
 * Code for looking up a device by name
 *---------------------------------------------------------------*/
static struct hash_cell *__get_name_cell(const char *str)
{
	struct hash_cell *hc;
	unsigned int h = hash_str(str);

	list_for_each_entry (hc, _name_buckets + h, name_list)
109 110
		if (!strcmp(hc->name, str)) {
			dm_get(hc->md);
L
Linus Torvalds 已提交
111
			return hc;
112
		}
L
Linus Torvalds 已提交
113 114 115 116 117 118 119 120 121 122

	return NULL;
}

static struct hash_cell *__get_uuid_cell(const char *str)
{
	struct hash_cell *hc;
	unsigned int h = hash_str(str);

	list_for_each_entry (hc, _uuid_buckets + h, uuid_list)
123 124
		if (!strcmp(hc->uuid, str)) {
			dm_get(hc->md);
L
Linus Torvalds 已提交
125
			return hc;
126
		}
L
Linus Torvalds 已提交
127 128 129 130

	return NULL;
}

131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148
static struct hash_cell *__get_dev_cell(uint64_t dev)
{
	struct mapped_device *md;
	struct hash_cell *hc;

	md = dm_get_md(huge_decode_dev(dev));
	if (!md)
		return NULL;

	hc = dm_get_mdptr(md);
	if (!hc) {
		dm_put(md);
		return NULL;
	}

	return hc;
}

L
Linus Torvalds 已提交
149 150 151 152 153 154 155 156 157 158 159 160
/*-----------------------------------------------------------------
 * Inserting, removing and renaming a device.
 *---------------------------------------------------------------*/
static struct hash_cell *alloc_cell(const char *name, const char *uuid,
				    struct mapped_device *md)
{
	struct hash_cell *hc;

	hc = kmalloc(sizeof(*hc), GFP_KERNEL);
	if (!hc)
		return NULL;

161
	hc->name = kstrdup(name, GFP_KERNEL);
L
Linus Torvalds 已提交
162 163 164 165 166 167 168 169 170
	if (!hc->name) {
		kfree(hc);
		return NULL;
	}

	if (!uuid)
		hc->uuid = NULL;

	else {
171
		hc->uuid = kstrdup(uuid, GFP_KERNEL);
L
Linus Torvalds 已提交
172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200
		if (!hc->uuid) {
			kfree(hc->name);
			kfree(hc);
			return NULL;
		}
	}

	INIT_LIST_HEAD(&hc->name_list);
	INIT_LIST_HEAD(&hc->uuid_list);
	hc->md = md;
	hc->new_map = NULL;
	return hc;
}

static void free_cell(struct hash_cell *hc)
{
	if (hc) {
		kfree(hc->name);
		kfree(hc->uuid);
		kfree(hc);
	}
}

/*
 * The kdev_t and uuid of a device can never change once it is
 * initially inserted.
 */
static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md)
{
201
	struct hash_cell *cell, *hc;
L
Linus Torvalds 已提交
202 203 204 205 206 207 208 209 210 211 212 213

	/*
	 * Allocate the new cells.
	 */
	cell = alloc_cell(name, uuid, md);
	if (!cell)
		return -ENOMEM;

	/*
	 * Insert the cell into both hash tables.
	 */
	down_write(&_hash_lock);
214 215 216
	hc = __get_name_cell(name);
	if (hc) {
		dm_put(hc->md);
L
Linus Torvalds 已提交
217
		goto bad;
218
	}
L
Linus Torvalds 已提交
219 220 221 222

	list_add(&cell->name_list, _name_buckets + hash_str(name));

	if (uuid) {
223 224
		hc = __get_uuid_cell(uuid);
		if (hc) {
L
Linus Torvalds 已提交
225
			list_del(&cell->name_list);
226
			dm_put(hc->md);
L
Linus Torvalds 已提交
227 228 229 230 231
			goto bad;
		}
		list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid));
	}
	dm_get(md);
M
Mikulas Patocka 已提交
232
	mutex_lock(&dm_hash_cells_mutex);
L
Linus Torvalds 已提交
233
	dm_set_mdptr(md, cell);
M
Mikulas Patocka 已提交
234
	mutex_unlock(&dm_hash_cells_mutex);
L
Linus Torvalds 已提交
235 236 237 238 239 240 241 242 243 244 245 246
	up_write(&_hash_lock);

	return 0;

 bad:
	up_write(&_hash_lock);
	free_cell(cell);
	return -EBUSY;
}

static void __hash_remove(struct hash_cell *hc)
{
247 248
	struct dm_table *table;

L
Linus Torvalds 已提交
249 250 251
	/* remove from the dev hash */
	list_del(&hc->uuid_list);
	list_del(&hc->name_list);
M
Mikulas Patocka 已提交
252
	mutex_lock(&dm_hash_cells_mutex);
L
Linus Torvalds 已提交
253
	dm_set_mdptr(hc->md, NULL);
M
Mikulas Patocka 已提交
254
	mutex_unlock(&dm_hash_cells_mutex);
255

256
	table = dm_get_live_table(hc->md);
257 258 259 260 261
	if (table) {
		dm_table_event(table);
		dm_table_put(table);
	}

L
Linus Torvalds 已提交
262
	if (hc->new_map)
263
		dm_table_destroy(hc->new_map);
M
Mike Anderson 已提交
264
	dm_put(hc->md);
L
Linus Torvalds 已提交
265 266 267
	free_cell(hc);
}

268
static void dm_hash_remove_all(int keep_open_devices)
L
Linus Torvalds 已提交
269
{
270
	int i, dev_skipped;
L
Linus Torvalds 已提交
271
	struct hash_cell *hc;
272 273 274 275
	struct mapped_device *md;

retry:
	dev_skipped = 0;
L
Linus Torvalds 已提交
276 277

	down_write(&_hash_lock);
278

L
Linus Torvalds 已提交
279
	for (i = 0; i < NUM_BUCKETS; i++) {
280 281 282
		list_for_each_entry(hc, _name_buckets + i, name_list) {
			md = hc->md;
			dm_get(md);
283

284 285
			if (keep_open_devices && dm_lock_for_deletion(md)) {
				dm_put(md);
286 287 288
				dev_skipped++;
				continue;
			}
289

L
Linus Torvalds 已提交
290
			__hash_remove(hc);
291

292
			up_write(&_hash_lock);
293

294
			dm_put(md);
295 296 297 298
			if (likely(keep_open_devices))
				dm_destroy(md);
			else
				dm_destroy_immediate(md);
299 300 301 302 303 304 305 306 307

			/*
			 * Some mapped devices may be using other mapped
			 * devices, so repeat until we make no further
			 * progress.  If a new mapped device is created
			 * here it will also get removed.
			 */
			goto retry;
		}
308 309
	}

L
Linus Torvalds 已提交
310
	up_write(&_hash_lock);
311 312 313

	if (dev_skipped)
		DMWARN("remove_all left %d open device(s)", dev_skipped);
L
Linus Torvalds 已提交
314 315
}

316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350
/*
 * Set the uuid of a hash_cell that isn't already set.
 */
static void __set_cell_uuid(struct hash_cell *hc, char *new_uuid)
{
	mutex_lock(&dm_hash_cells_mutex);
	hc->uuid = new_uuid;
	mutex_unlock(&dm_hash_cells_mutex);

	list_add(&hc->uuid_list, _uuid_buckets + hash_str(new_uuid));
}

/*
 * Changes the name of a hash_cell and returns the old name for
 * the caller to free.
 */
static char *__change_cell_name(struct hash_cell *hc, char *new_name)
{
	char *old_name;

	/*
	 * Rename and move the name cell.
	 */
	list_del(&hc->name_list);
	old_name = hc->name;

	mutex_lock(&dm_hash_cells_mutex);
	hc->name = new_name;
	mutex_unlock(&dm_hash_cells_mutex);

	list_add(&hc->name_list, _name_buckets + hash_str(new_name));

	return old_name;
}

351 352
static struct mapped_device *dm_hash_rename(struct dm_ioctl *param,
					    const char *new)
L
Linus Torvalds 已提交
353
{
354
	char *new_data, *old_name = NULL;
L
Linus Torvalds 已提交
355
	struct hash_cell *hc;
356
	struct dm_table *table;
357
	struct mapped_device *md;
358
	unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
L
Linus Torvalds 已提交
359 360 361 362

	/*
	 * duplicate new.
	 */
363 364
	new_data = kstrdup(new, GFP_KERNEL);
	if (!new_data)
365
		return ERR_PTR(-ENOMEM);
L
Linus Torvalds 已提交
366 367 368 369 370 371

	down_write(&_hash_lock);

	/*
	 * Is new free ?
	 */
372 373 374 375 376
	if (change_uuid)
		hc = __get_uuid_cell(new);
	else
		hc = __get_name_cell(new);

L
Linus Torvalds 已提交
377
	if (hc) {
378 379 380
		DMWARN("Unable to change %s on mapped device %s to one that "
		       "already exists: %s",
		       change_uuid ? "uuid" : "name",
381
		       param->name, new);
382
		dm_put(hc->md);
L
Linus Torvalds 已提交
383
		up_write(&_hash_lock);
384
		kfree(new_data);
385
		return ERR_PTR(-EBUSY);
L
Linus Torvalds 已提交
386 387 388 389 390
	}

	/*
	 * Is there such a device as 'old' ?
	 */
391
	hc = __get_name_cell(param->name);
L
Linus Torvalds 已提交
392
	if (!hc) {
393 394
		DMWARN("Unable to rename non-existent device, %s to %s%s",
		       param->name, change_uuid ? "uuid " : "", new);
L
Linus Torvalds 已提交
395
		up_write(&_hash_lock);
396
		kfree(new_data);
397
		return ERR_PTR(-ENXIO);
L
Linus Torvalds 已提交
398 399 400
	}

	/*
401
	 * Does this device already have a uuid?
L
Linus Torvalds 已提交
402
	 */
403 404 405 406 407 408 409 410 411 412 413 414 415 416
	if (change_uuid && hc->uuid) {
		DMWARN("Unable to change uuid of mapped device %s to %s "
		       "because uuid is already set to %s",
		       param->name, new, hc->uuid);
		dm_put(hc->md);
		up_write(&_hash_lock);
		kfree(new_data);
		return ERR_PTR(-EINVAL);
	}

	if (change_uuid)
		__set_cell_uuid(hc, new_data);
	else
		old_name = __change_cell_name(hc, new_data);
L
Linus Torvalds 已提交
417

418 419 420
	/*
	 * Wake up any dm event waiters.
	 */
421
	table = dm_get_live_table(hc->md);
422 423 424 425 426
	if (table) {
		dm_table_event(table);
		dm_table_put(table);
	}

427 428
	if (!dm_kobject_uevent(hc->md, KOBJ_CHANGE, param->event_nr))
		param->flags |= DM_UEVENT_GENERATED_FLAG;
429

430
	md = hc->md;
L
Linus Torvalds 已提交
431 432
	up_write(&_hash_lock);
	kfree(old_name);
433 434

	return md;
L
Linus Torvalds 已提交
435 436 437 438 439 440 441 442 443 444 445 446 447
}

/*-----------------------------------------------------------------
 * Implementation of the ioctl commands
 *---------------------------------------------------------------*/
/*
 * All the ioctl commands get dispatched to functions with this
 * prototype.
 */
typedef int (*ioctl_fn)(struct dm_ioctl *param, size_t param_size);

static int remove_all(struct dm_ioctl *param, size_t param_size)
{
448
	dm_hash_remove_all(1);
L
Linus Torvalds 已提交
449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521
	param->data_size = 0;
	return 0;
}

/*
 * Round up the ptr to an 8-byte boundary.
 */
#define ALIGN_MASK 7
static inline void *align_ptr(void *ptr)
{
	return (void *) (((size_t) (ptr + ALIGN_MASK)) & ~ALIGN_MASK);
}

/*
 * Retrieves the data payload buffer from an already allocated
 * struct dm_ioctl.
 */
static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
			       size_t *len)
{
	param->data_start = align_ptr(param + 1) - (void *) param;

	if (param->data_start < param_size)
		*len = param_size - param->data_start;
	else
		*len = 0;

	return ((void *) param) + param->data_start;
}

static int list_devices(struct dm_ioctl *param, size_t param_size)
{
	unsigned int i;
	struct hash_cell *hc;
	size_t len, needed = 0;
	struct gendisk *disk;
	struct dm_name_list *nl, *old_nl = NULL;

	down_write(&_hash_lock);

	/*
	 * Loop through all the devices working out how much
	 * space we need.
	 */
	for (i = 0; i < NUM_BUCKETS; i++) {
		list_for_each_entry (hc, _name_buckets + i, name_list) {
			needed += sizeof(struct dm_name_list);
			needed += strlen(hc->name) + 1;
			needed += ALIGN_MASK;
		}
	}

	/*
	 * Grab our output buffer.
	 */
	nl = get_result_buffer(param, param_size, &len);
	if (len < needed) {
		param->flags |= DM_BUFFER_FULL_FLAG;
		goto out;
	}
	param->data_size = param->data_start + needed;

	nl->dev = 0;	/* Flags no data */

	/*
	 * Now loop through filling out the names.
	 */
	for (i = 0; i < NUM_BUCKETS; i++) {
		list_for_each_entry (hc, _name_buckets + i, name_list) {
			if (old_nl)
				old_nl->next = (uint32_t) ((void *) nl -
							   (void *) old_nl);
			disk = dm_disk(hc->md);
522
			nl->dev = huge_encode_dev(disk_devt(disk));
L
Linus Torvalds 已提交
523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539
			nl->next = 0;
			strcpy(nl->name, hc->name);

			old_nl = nl;
			nl = align_ptr(((void *) ++nl) + strlen(hc->name) + 1);
		}
	}

 out:
	up_write(&_hash_lock);
	return 0;
}

static void list_version_get_needed(struct target_type *tt, void *needed_param)
{
    size_t *needed = needed_param;

540
    *needed += sizeof(struct dm_target_versions);
L
Linus Torvalds 已提交
541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617
    *needed += strlen(tt->name);
    *needed += ALIGN_MASK;
}

static void list_version_get_info(struct target_type *tt, void *param)
{
    struct vers_iter *info = param;

    /* Check space - it might have changed since the first iteration */
    if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 >
	info->end) {

	info->flags = DM_BUFFER_FULL_FLAG;
	return;
    }

    if (info->old_vers)
	info->old_vers->next = (uint32_t) ((void *)info->vers -
					   (void *)info->old_vers);
    info->vers->version[0] = tt->version[0];
    info->vers->version[1] = tt->version[1];
    info->vers->version[2] = tt->version[2];
    info->vers->next = 0;
    strcpy(info->vers->name, tt->name);

    info->old_vers = info->vers;
    info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1);
}

static int list_versions(struct dm_ioctl *param, size_t param_size)
{
	size_t len, needed = 0;
	struct dm_target_versions *vers;
	struct vers_iter iter_info;

	/*
	 * Loop through all the devices working out how much
	 * space we need.
	 */
	dm_target_iterate(list_version_get_needed, &needed);

	/*
	 * Grab our output buffer.
	 */
	vers = get_result_buffer(param, param_size, &len);
	if (len < needed) {
		param->flags |= DM_BUFFER_FULL_FLAG;
		goto out;
	}
	param->data_size = param->data_start + needed;

	iter_info.param_size = param_size;
	iter_info.old_vers = NULL;
	iter_info.vers = vers;
	iter_info.flags = 0;
	iter_info.end = (char *)vers+len;

	/*
	 * Now loop through filling out the names & versions.
	 */
	dm_target_iterate(list_version_get_info, &iter_info);
	param->flags |= iter_info.flags;

 out:
	return 0;
}

static int check_name(const char *name)
{
	if (strchr(name, '/')) {
		DMWARN("invalid device name");
		return -EINVAL;
	}

	return 0;
}

618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651
/*
 * On successful return, the caller must not attempt to acquire
 * _hash_lock without first calling dm_table_put, because dm_table_destroy
 * waits for this dm_table_put and could be called under this lock.
 */
static struct dm_table *dm_get_inactive_table(struct mapped_device *md)
{
	struct hash_cell *hc;
	struct dm_table *table = NULL;

	down_read(&_hash_lock);
	hc = dm_get_mdptr(md);
	if (!hc || hc->md != md) {
		DMWARN("device has been removed from the dev hash table.");
		goto out;
	}

	table = hc->new_map;
	if (table)
		dm_table_get(table);

out:
	up_read(&_hash_lock);

	return table;
}

static struct dm_table *dm_get_live_or_inactive_table(struct mapped_device *md,
						      struct dm_ioctl *param)
{
	return (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) ?
		dm_get_inactive_table(md) : dm_get_live_table(md);
}

L
Linus Torvalds 已提交
652 653 654 655
/*
 * Fills in a dm_ioctl structure, ready for sending back to
 * userland.
 */
656
static void __dev_status(struct mapped_device *md, struct dm_ioctl *param)
L
Linus Torvalds 已提交
657 658 659 660 661 662 663
{
	struct gendisk *disk = dm_disk(md);
	struct dm_table *table;

	param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
			  DM_ACTIVE_PRESENT_FLAG);

664
	if (dm_suspended_md(md))
L
Linus Torvalds 已提交
665 666
		param->flags |= DM_SUSPEND_FLAG;

667
	param->dev = huge_encode_dev(disk_devt(disk));
L
Linus Torvalds 已提交
668

669 670 671 672 673 674
	/*
	 * Yes, this will be out of date by the time it gets back
	 * to userland, but it is still very useful for
	 * debugging.
	 */
	param->open_count = dm_open_count(md);
L
Linus Torvalds 已提交
675 676

	param->event_nr = dm_get_event_nr(md);
677
	param->target_count = 0;
L
Linus Torvalds 已提交
678

679
	table = dm_get_live_table(md);
L
Linus Torvalds 已提交
680
	if (table) {
681 682 683 684 685
		if (!(param->flags & DM_QUERY_INACTIVE_TABLE_FLAG)) {
			if (get_disk_ro(disk))
				param->flags |= DM_READONLY_FLAG;
			param->target_count = dm_table_get_num_targets(table);
		}
L
Linus Torvalds 已提交
686
		dm_table_put(table);
687 688 689 690 691 692 693 694 695 696 697 698 699

		param->flags |= DM_ACTIVE_PRESENT_FLAG;
	}

	if (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) {
		table = dm_get_inactive_table(md);
		if (table) {
			if (!(dm_table_get_mode(table) & FMODE_WRITE))
				param->flags |= DM_READONLY_FLAG;
			param->target_count = dm_table_get_num_targets(table);
			dm_table_put(table);
		}
	}
L
Linus Torvalds 已提交
700 701 702 703
}

static int dev_create(struct dm_ioctl *param, size_t param_size)
{
704
	int r, m = DM_ANY_MINOR;
L
Linus Torvalds 已提交
705 706 707 708 709 710 711
	struct mapped_device *md;

	r = check_name(param->name);
	if (r)
		return r;

	if (param->flags & DM_PERSISTENT_DEV_FLAG)
712
		m = MINOR(huge_decode_dev(param->dev));
L
Linus Torvalds 已提交
713

714
	r = dm_create(m, &md);
L
Linus Torvalds 已提交
715 716 717 718
	if (r)
		return r;

	r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
719 720 721 722 723
	if (r) {
		dm_put(md);
		dm_destroy(md);
		return r;
	}
L
Linus Torvalds 已提交
724 725 726

	param->flags &= ~DM_INACTIVE_PRESENT_FLAG;

727 728
	__dev_status(md, param);

L
Linus Torvalds 已提交
729 730
	dm_put(md);

731
	return 0;
L
Linus Torvalds 已提交
732 733 734 735 736
}

/*
 * Always use UUID for lookups if it's present, otherwise use name or dev.
 */
737
static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
L
Linus Torvalds 已提交
738
{
739
	struct hash_cell *hc = NULL;
A
Alasdair G Kergon 已提交
740

741
	if (*param->uuid) {
742 743 744
		if (*param->name || param->dev)
			return NULL;

745 746 747
		hc = __get_uuid_cell(param->uuid);
		if (!hc)
			return NULL;
748
	} else if (*param->name) {
749 750 751
		if (param->dev)
			return NULL;

752 753 754
		hc = __get_name_cell(param->name);
		if (!hc)
			return NULL;
755 756 757 758 759
	} else if (param->dev) {
		hc = __get_dev_cell(param->dev);
		if (!hc)
			return NULL;
	} else
760
		return NULL;
A
Alasdair G Kergon 已提交
761

762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777
	/*
	 * Sneakily write in both the name and the uuid
	 * while we have the cell.
	 */
	strlcpy(param->name, hc->name, sizeof(param->name));
	if (hc->uuid)
		strlcpy(param->uuid, hc->uuid, sizeof(param->uuid));
	else
		param->uuid[0] = '\0';

	if (hc->new_map)
		param->flags |= DM_INACTIVE_PRESENT_FLAG;
	else
		param->flags &= ~DM_INACTIVE_PRESENT_FLAG;

	return hc;
L
Linus Torvalds 已提交
778 779
}

780
static struct mapped_device *find_device(struct dm_ioctl *param)
L
Linus Torvalds 已提交
781 782 783 784 785 786
{
	struct hash_cell *hc;
	struct mapped_device *md = NULL;

	down_read(&_hash_lock);
	hc = __find_device_hash_cell(param);
787
	if (hc)
L
Linus Torvalds 已提交
788 789 790 791 792 793 794 795 796
		md = hc->md;
	up_read(&_hash_lock);

	return md;
}

static int dev_remove(struct dm_ioctl *param, size_t param_size)
{
	struct hash_cell *hc;
797
	struct mapped_device *md;
798
	int r;
L
Linus Torvalds 已提交
799 800 801 802 803

	down_write(&_hash_lock);
	hc = __find_device_hash_cell(param);

	if (!hc) {
804
		DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
L
Linus Torvalds 已提交
805 806 807 808
		up_write(&_hash_lock);
		return -ENXIO;
	}

809 810
	md = hc->md;

811 812 813 814 815
	/*
	 * Ensure the device is not open and nothing further can open it.
	 */
	r = dm_lock_for_deletion(md);
	if (r) {
816
		DMDEBUG_LIMIT("unable to remove open device %s", hc->name);
817 818 819 820 821
		up_write(&_hash_lock);
		dm_put(md);
		return r;
	}

L
Linus Torvalds 已提交
822 823
	__hash_remove(hc);
	up_write(&_hash_lock);
M
Milan Broz 已提交
824

825 826
	if (!dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr))
		param->flags |= DM_UEVENT_GENERATED_FLAG;
M
Milan Broz 已提交
827

828
	dm_put(md);
829
	dm_destroy(md);
L
Linus Torvalds 已提交
830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848
	return 0;
}

/*
 * Check a string doesn't overrun the chunk of
 * memory we copied from userland.
 */
static int invalid_str(char *str, void *end)
{
	while ((void *) str < end)
		if (!*str++)
			return 0;

	return -EINVAL;
}

static int dev_rename(struct dm_ioctl *param, size_t param_size)
{
	int r;
849
	char *new_data = (char *) param + param->data_start;
850
	struct mapped_device *md;
851
	unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
L
Linus Torvalds 已提交
852

853 854 855 856
	if (new_data < param->data ||
	    invalid_str(new_data, (void *) param + param_size) ||
	    strlen(new_data) > (change_uuid ? DM_UUID_LEN - 1 : DM_NAME_LEN - 1)) {
		DMWARN("Invalid new mapped device name or uuid string supplied.");
L
Linus Torvalds 已提交
857 858 859
		return -EINVAL;
	}

860 861 862 863 864
	if (!change_uuid) {
		r = check_name(new_data);
		if (r)
			return r;
	}
L
Linus Torvalds 已提交
865

866
	md = dm_hash_rename(param, new_data);
867 868
	if (IS_ERR(md))
		return PTR_ERR(md);
869

870 871 872 873
	__dev_status(md, param);
	dm_put(md);

	return 0;
L
Linus Torvalds 已提交
874 875
}

D
Darrick J. Wong 已提交
876 877 878 879 880 881 882
static int dev_set_geometry(struct dm_ioctl *param, size_t param_size)
{
	int r = -EINVAL, x;
	struct mapped_device *md;
	struct hd_geometry geometry;
	unsigned long indata[4];
	char *geostr = (char *) param + param->data_start;
883
	char dummy;
D
Darrick J. Wong 已提交
884 885 886 887 888

	md = find_device(param);
	if (!md)
		return -ENXIO;

A
Alasdair G Kergon 已提交
889
	if (geostr < param->data ||
D
Darrick J. Wong 已提交
890 891 892 893 894
	    invalid_str(geostr, (void *) param + param_size)) {
		DMWARN("Invalid geometry supplied.");
		goto out;
	}

895 896
	x = sscanf(geostr, "%lu %lu %lu %lu%c", indata,
		   indata + 1, indata + 2, indata + 3, &dummy);
D
Darrick J. Wong 已提交
897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922

	if (x != 4) {
		DMWARN("Unable to interpret geometry settings.");
		goto out;
	}

	if (indata[0] > 65535 || indata[1] > 255 ||
	    indata[2] > 255 || indata[3] > ULONG_MAX) {
		DMWARN("Geometry exceeds range limits.");
		goto out;
	}

	geometry.cylinders = indata[0];
	geometry.heads = indata[1];
	geometry.sectors = indata[2];
	geometry.start = indata[3];

	r = dm_set_geometry(md, &geometry);

	param->data_size = 0;

out:
	dm_put(md);
	return r;
}

L
Linus Torvalds 已提交
923 924 925
static int do_suspend(struct dm_ioctl *param)
{
	int r = 0;
926
	unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
L
Linus Torvalds 已提交
927 928 929 930 931 932
	struct mapped_device *md;

	md = find_device(param);
	if (!md)
		return -ENXIO;

933
	if (param->flags & DM_SKIP_LOCKFS_FLAG)
934
		suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
935 936
	if (param->flags & DM_NOFLUSH_FLAG)
		suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
937

938
	if (!dm_suspended_md(md)) {
939
		r = dm_suspend(md, suspend_flags);
940 941 942
		if (r)
			goto out;
	}
L
Linus Torvalds 已提交
943

944
	__dev_status(md, param);
L
Linus Torvalds 已提交
945

946
out:
L
Linus Torvalds 已提交
947
	dm_put(md);
948

L
Linus Torvalds 已提交
949 950 951 952 953 954
	return r;
}

static int do_resume(struct dm_ioctl *param)
{
	int r = 0;
955
	unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
L
Linus Torvalds 已提交
956 957
	struct hash_cell *hc;
	struct mapped_device *md;
958
	struct dm_table *new_map, *old_map = NULL;
L
Linus Torvalds 已提交
959 960 961 962 963

	down_write(&_hash_lock);

	hc = __find_device_hash_cell(param);
	if (!hc) {
964
		DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
L
Linus Torvalds 已提交
965 966 967 968 969 970 971 972 973 974 975 976 977 978 979
		up_write(&_hash_lock);
		return -ENXIO;
	}

	md = hc->md;

	new_map = hc->new_map;
	hc->new_map = NULL;
	param->flags &= ~DM_INACTIVE_PRESENT_FLAG;

	up_write(&_hash_lock);

	/* Do we need to load a new map ? */
	if (new_map) {
		/* Suspend if it isn't already suspended */
980
		if (param->flags & DM_SKIP_LOCKFS_FLAG)
981
			suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
982 983
		if (param->flags & DM_NOFLUSH_FLAG)
			suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
984
		if (!dm_suspended_md(md))
985
			dm_suspend(md, suspend_flags);
L
Linus Torvalds 已提交
986

987 988
		old_map = dm_swap_table(md, new_map);
		if (IS_ERR(old_map)) {
989
			dm_table_destroy(new_map);
L
Linus Torvalds 已提交
990
			dm_put(md);
991
			return PTR_ERR(old_map);
L
Linus Torvalds 已提交
992 993 994 995 996 997 998 999
		}

		if (dm_table_get_mode(new_map) & FMODE_WRITE)
			set_disk_ro(dm_disk(md), 0);
		else
			set_disk_ro(dm_disk(md), 1);
	}

1000
	if (dm_suspended_md(md)) {
L
Linus Torvalds 已提交
1001
		r = dm_resume(md);
1002 1003
		if (!r && !dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr))
			param->flags |= DM_UEVENT_GENERATED_FLAG;
1004
	}
L
Linus Torvalds 已提交
1005

1006 1007
	if (old_map)
		dm_table_destroy(old_map);
M
Milan Broz 已提交
1008

1009
	if (!r)
1010
		__dev_status(md, param);
L
Linus Torvalds 已提交
1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039

	dm_put(md);
	return r;
}

/*
 * Set or unset the suspension state of a device.
 * If the device already is in the requested state we just return its status.
 */
static int dev_suspend(struct dm_ioctl *param, size_t param_size)
{
	if (param->flags & DM_SUSPEND_FLAG)
		return do_suspend(param);

	return do_resume(param);
}

/*
 * Copies device info back to user space, used by
 * the create and info ioctls.
 */
static int dev_status(struct dm_ioctl *param, size_t param_size)
{
	struct mapped_device *md;

	md = find_device(param);
	if (!md)
		return -ENXIO;

1040
	__dev_status(md, param);
L
Linus Torvalds 已提交
1041
	dm_put(md);
1042 1043

	return 0;
L
Linus Torvalds 已提交
1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056
}

/*
 * Build up the status struct for each target
 */
static void retrieve_status(struct dm_table *table,
			    struct dm_ioctl *param, size_t param_size)
{
	unsigned int i, num_targets;
	struct dm_target_spec *spec;
	char *outbuf, *outptr;
	status_type_t type;
	size_t remaining, len, used = 0;
1057
	unsigned status_flags = 0;
L
Linus Torvalds 已提交
1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093

	outptr = outbuf = get_result_buffer(param, param_size, &len);

	if (param->flags & DM_STATUS_TABLE_FLAG)
		type = STATUSTYPE_TABLE;
	else
		type = STATUSTYPE_INFO;

	/* Get all the target info */
	num_targets = dm_table_get_num_targets(table);
	for (i = 0; i < num_targets; i++) {
		struct dm_target *ti = dm_table_get_target(table, i);

		remaining = len - (outptr - outbuf);
		if (remaining <= sizeof(struct dm_target_spec)) {
			param->flags |= DM_BUFFER_FULL_FLAG;
			break;
		}

		spec = (struct dm_target_spec *) outptr;

		spec->status = 0;
		spec->sector_start = ti->begin;
		spec->length = ti->len;
		strncpy(spec->target_type, ti->type->name,
			sizeof(spec->target_type));

		outptr += sizeof(struct dm_target_spec);
		remaining = len - (outptr - outbuf);
		if (remaining <= 0) {
			param->flags |= DM_BUFFER_FULL_FLAG;
			break;
		}

		/* Get the status/table string from the target driver */
		if (ti->type->status) {
1094 1095 1096
			if (param->flags & DM_NOFLUSH_FLAG)
				status_flags |= DM_STATUS_NOFLUSH_FLAG;
			if (ti->type->status(ti, type, status_flags, outptr, remaining)) {
L
Linus Torvalds 已提交
1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120
				param->flags |= DM_BUFFER_FULL_FLAG;
				break;
			}
		} else
			outptr[0] = '\0';

		outptr += strlen(outptr) + 1;
		used = param->data_start + (outptr - outbuf);

		outptr = align_ptr(outptr);
		spec->next = outptr - outbuf;
	}

	if (used)
		param->data_size = used;

	param->target_count = num_targets;
}

/*
 * Wait for a device to report an event
 */
static int dev_wait(struct dm_ioctl *param, size_t param_size)
{
1121
	int r = 0;
L
Linus Torvalds 已提交
1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141
	struct mapped_device *md;
	struct dm_table *table;

	md = find_device(param);
	if (!md)
		return -ENXIO;

	/*
	 * Wait for a notification event
	 */
	if (dm_wait_event(md, param->event_nr)) {
		r = -ERESTARTSYS;
		goto out;
	}

	/*
	 * The userland program is going to want to know what
	 * changed to trigger the event, so we may as well tell
	 * him and save an ioctl.
	 */
1142
	__dev_status(md, param);
L
Linus Torvalds 已提交
1143

1144
	table = dm_get_live_or_inactive_table(md, param);
L
Linus Torvalds 已提交
1145 1146 1147 1148 1149
	if (table) {
		retrieve_status(table, param, param_size);
		dm_table_put(table);
	}

1150
out:
L
Linus Torvalds 已提交
1151
	dm_put(md);
1152

L
Linus Torvalds 已提交
1153 1154 1155
	return r;
}

1156
static inline fmode_t get_mode(struct dm_ioctl *param)
L
Linus Torvalds 已提交
1157
{
1158
	fmode_t mode = FMODE_READ | FMODE_WRITE;
L
Linus Torvalds 已提交
1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220

	if (param->flags & DM_READONLY_FLAG)
		mode = FMODE_READ;

	return mode;
}

static int next_target(struct dm_target_spec *last, uint32_t next, void *end,
		       struct dm_target_spec **spec, char **target_params)
{
	*spec = (struct dm_target_spec *) ((unsigned char *) last + next);
	*target_params = (char *) (*spec + 1);

	if (*spec < (last + 1))
		return -EINVAL;

	return invalid_str(*target_params, end);
}

static int populate_table(struct dm_table *table,
			  struct dm_ioctl *param, size_t param_size)
{
	int r;
	unsigned int i = 0;
	struct dm_target_spec *spec = (struct dm_target_spec *) param;
	uint32_t next = param->data_start;
	void *end = (void *) param + param_size;
	char *target_params;

	if (!param->target_count) {
		DMWARN("populate_table: no targets specified");
		return -EINVAL;
	}

	for (i = 0; i < param->target_count; i++) {

		r = next_target(spec, next, end, &spec, &target_params);
		if (r) {
			DMWARN("unable to find target");
			return r;
		}

		r = dm_table_add_target(table, spec->target_type,
					(sector_t) spec->sector_start,
					(sector_t) spec->length,
					target_params);
		if (r) {
			DMWARN("error adding target to table");
			return r;
		}

		next = spec->next;
	}

	return dm_table_complete(table);
}

static int table_load(struct dm_ioctl *param, size_t param_size)
{
	int r;
	struct hash_cell *hc;
	struct dm_table *t;
M
Mike Anderson 已提交
1221
	struct mapped_device *md;
1222
	struct target_type *immutable_target_type;
M
Mike Anderson 已提交
1223 1224 1225 1226

	md = find_device(param);
	if (!md)
		return -ENXIO;
L
Linus Torvalds 已提交
1227

M
Mike Anderson 已提交
1228
	r = dm_table_create(&t, get_mode(param), param->target_count, md);
L
Linus Torvalds 已提交
1229
	if (r)
M
Mike Anderson 已提交
1230
		goto out;
L
Linus Torvalds 已提交
1231 1232 1233

	r = populate_table(t, param, param_size);
	if (r) {
1234
		dm_table_destroy(t);
M
Mike Anderson 已提交
1235
		goto out;
L
Linus Torvalds 已提交
1236 1237
	}

1238 1239 1240 1241 1242 1243 1244 1245 1246 1247
	immutable_target_type = dm_get_immutable_target_type(md);
	if (immutable_target_type &&
	    (immutable_target_type != dm_table_get_immutable_target_type(t))) {
		DMWARN("can't replace immutable target type %s",
		       immutable_target_type->name);
		dm_table_destroy(t);
		r = -EINVAL;
		goto out;
	}

1248
	/* Protect md->type and md->queue against concurrent table loads. */
1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259
	dm_lock_md_type(md);
	if (dm_get_md_type(md) == DM_TYPE_NONE)
		/* Initial table load: acquire type of table. */
		dm_set_md_type(md, dm_table_get_type(t));
	else if (dm_get_md_type(md) != dm_table_get_type(t)) {
		DMWARN("can't change device type after initial table load.");
		dm_table_destroy(t);
		dm_unlock_md_type(md);
		r = -EINVAL;
		goto out;
	}
1260 1261 1262 1263 1264 1265 1266 1267 1268

	/* setup md->queue to reflect md's type (may block) */
	r = dm_setup_md_queue(md);
	if (r) {
		DMWARN("unable to set up device queue for new table.");
		dm_table_destroy(t);
		dm_unlock_md_type(md);
		goto out;
	}
1269 1270 1271
	dm_unlock_md_type(md);

	/* stage inactive table */
L
Linus Torvalds 已提交
1272
	down_write(&_hash_lock);
M
Mike Anderson 已提交
1273 1274 1275
	hc = dm_get_mdptr(md);
	if (!hc || hc->md != md) {
		DMWARN("device has been removed from the dev hash table.");
1276
		dm_table_destroy(t);
M
Mike Anderson 已提交
1277 1278 1279
		up_write(&_hash_lock);
		r = -ENXIO;
		goto out;
L
Linus Torvalds 已提交
1280 1281 1282
	}

	if (hc->new_map)
1283
		dm_table_destroy(hc->new_map);
L
Linus Torvalds 已提交
1284
	hc->new_map = t;
M
Mike Anderson 已提交
1285 1286
	up_write(&_hash_lock);

L
Linus Torvalds 已提交
1287
	param->flags |= DM_INACTIVE_PRESENT_FLAG;
1288
	__dev_status(md, param);
M
Mike Anderson 已提交
1289 1290 1291

out:
	dm_put(md);
L
Linus Torvalds 已提交
1292 1293 1294 1295 1296 1297 1298

	return r;
}

static int table_clear(struct dm_ioctl *param, size_t param_size)
{
	struct hash_cell *hc;
1299
	struct mapped_device *md;
L
Linus Torvalds 已提交
1300 1301 1302 1303 1304

	down_write(&_hash_lock);

	hc = __find_device_hash_cell(param);
	if (!hc) {
1305
		DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
L
Linus Torvalds 已提交
1306 1307 1308 1309 1310
		up_write(&_hash_lock);
		return -ENXIO;
	}

	if (hc->new_map) {
1311
		dm_table_destroy(hc->new_map);
L
Linus Torvalds 已提交
1312 1313 1314 1315 1316
		hc->new_map = NULL;
	}

	param->flags &= ~DM_INACTIVE_PRESENT_FLAG;

1317
	__dev_status(hc->md, param);
1318
	md = hc->md;
L
Linus Torvalds 已提交
1319
	up_write(&_hash_lock);
1320
	dm_put(md);
1321 1322

	return 0;
L
Linus Torvalds 已提交
1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333
}

/*
 * Retrieves a list of devices used by a particular dm device.
 */
static void retrieve_deps(struct dm_table *table,
			  struct dm_ioctl *param, size_t param_size)
{
	unsigned int count = 0;
	struct list_head *tmp;
	size_t len, needed;
M
Mikulas Patocka 已提交
1334
	struct dm_dev_internal *dd;
L
Linus Torvalds 已提交
1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359
	struct dm_target_deps *deps;

	deps = get_result_buffer(param, param_size, &len);

	/*
	 * Count the devices.
	 */
	list_for_each (tmp, dm_table_get_devices(table))
		count++;

	/*
	 * Check we have enough space.
	 */
	needed = sizeof(*deps) + (sizeof(*deps->dev) * count);
	if (len < needed) {
		param->flags |= DM_BUFFER_FULL_FLAG;
		return;
	}

	/*
	 * Fill in the devices.
	 */
	deps->count = count;
	count = 0;
	list_for_each_entry (dd, dm_table_get_devices(table), list)
M
Mikulas Patocka 已提交
1360
		deps->dev[count++] = huge_encode_dev(dd->dm_dev.bdev->bd_dev);
L
Linus Torvalds 已提交
1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373

	param->data_size = param->data_start + needed;
}

static int table_deps(struct dm_ioctl *param, size_t param_size)
{
	struct mapped_device *md;
	struct dm_table *table;

	md = find_device(param);
	if (!md)
		return -ENXIO;

1374
	__dev_status(md, param);
L
Linus Torvalds 已提交
1375

1376
	table = dm_get_live_or_inactive_table(md, param);
L
Linus Torvalds 已提交
1377 1378 1379 1380 1381 1382
	if (table) {
		retrieve_deps(table, param, param_size);
		dm_table_put(table);
	}

	dm_put(md);
1383 1384

	return 0;
L
Linus Torvalds 已提交
1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399
}

/*
 * Return the status of a device as a text string for each
 * target.
 */
static int table_status(struct dm_ioctl *param, size_t param_size)
{
	struct mapped_device *md;
	struct dm_table *table;

	md = find_device(param);
	if (!md)
		return -ENXIO;

1400
	__dev_status(md, param);
L
Linus Torvalds 已提交
1401

1402
	table = dm_get_live_or_inactive_table(md, param);
L
Linus Torvalds 已提交
1403 1404 1405 1406 1407 1408
	if (table) {
		retrieve_status(table, param, param_size);
		dm_table_put(table);
	}

	dm_put(md);
1409 1410

	return 0;
L
Linus Torvalds 已提交
1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428
}

/*
 * Pass a message to the target that's at the supplied device offset.
 */
static int target_message(struct dm_ioctl *param, size_t param_size)
{
	int r, argc;
	char **argv;
	struct mapped_device *md;
	struct dm_table *table;
	struct dm_target *ti;
	struct dm_target_msg *tmsg = (void *) param + param->data_start;

	md = find_device(param);
	if (!md)
		return -ENXIO;

M
Milan Broz 已提交
1429
	if (tmsg < (struct dm_target_msg *) param->data ||
L
Linus Torvalds 已提交
1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441
	    invalid_str(tmsg->message, (void *) param + param_size)) {
		DMWARN("Invalid target message parameters.");
		r = -EINVAL;
		goto out;
	}

	r = dm_split_args(&argc, &argv, tmsg->message);
	if (r) {
		DMWARN("Failed to split target message parameters");
		goto out;
	}

1442 1443
	if (!argc) {
		DMWARN("Empty message received.");
1444
		goto out_argv;
1445 1446
	}

1447
	table = dm_get_live_table(md);
L
Linus Torvalds 已提交
1448 1449 1450
	if (!table)
		goto out_argv;

1451 1452 1453 1454 1455
	if (dm_deleting_md(md)) {
		r = -ENXIO;
		goto out_table;
	}

1456 1457
	ti = dm_table_find_target(table, tmsg->sector);
	if (!dm_target_is_valid(ti)) {
L
Linus Torvalds 已提交
1458 1459
		DMWARN("Target message sector outside device.");
		r = -EINVAL;
1460
	} else if (ti->type->message)
L
Linus Torvalds 已提交
1461 1462 1463 1464 1465 1466
		r = ti->type->message(ti, argc, argv);
	else {
		DMWARN("Target type does not support messages");
		r = -EINVAL;
	}

1467
 out_table:
L
Linus Torvalds 已提交
1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504
	dm_table_put(table);
 out_argv:
	kfree(argv);
 out:
	param->data_size = 0;
	dm_put(md);
	return r;
}

/*-----------------------------------------------------------------
 * Implementation of open/close/ioctl on the special char
 * device.
 *---------------------------------------------------------------*/
static ioctl_fn lookup_ioctl(unsigned int cmd)
{
	static struct {
		int cmd;
		ioctl_fn fn;
	} _ioctls[] = {
		{DM_VERSION_CMD, NULL},	/* version is dealt with elsewhere */
		{DM_REMOVE_ALL_CMD, remove_all},
		{DM_LIST_DEVICES_CMD, list_devices},

		{DM_DEV_CREATE_CMD, dev_create},
		{DM_DEV_REMOVE_CMD, dev_remove},
		{DM_DEV_RENAME_CMD, dev_rename},
		{DM_DEV_SUSPEND_CMD, dev_suspend},
		{DM_DEV_STATUS_CMD, dev_status},
		{DM_DEV_WAIT_CMD, dev_wait},

		{DM_TABLE_LOAD_CMD, table_load},
		{DM_TABLE_CLEAR_CMD, table_clear},
		{DM_TABLE_DEPS_CMD, table_deps},
		{DM_TABLE_STATUS_CMD, table_status},

		{DM_LIST_VERSIONS_CMD, list_versions},

D
Darrick J. Wong 已提交
1505 1506
		{DM_TARGET_MSG_CMD, target_message},
		{DM_DEV_SET_GEOMETRY_CMD, dev_set_geometry}
L
Linus Torvalds 已提交
1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548
	};

	return (cmd >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[cmd].fn;
}

/*
 * As well as checking the version compatibility this always
 * copies the kernel interface version out.
 */
static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
{
	uint32_t version[3];
	int r = 0;

	if (copy_from_user(version, user->version, sizeof(version)))
		return -EFAULT;

	if ((DM_VERSION_MAJOR != version[0]) ||
	    (DM_VERSION_MINOR < version[1])) {
		DMWARN("ioctl interface mismatch: "
		       "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
		       DM_VERSION_MAJOR, DM_VERSION_MINOR,
		       DM_VERSION_PATCHLEVEL,
		       version[0], version[1], version[2], cmd);
		r = -EINVAL;
	}

	/*
	 * Fill in the kernel version.
	 */
	version[0] = DM_VERSION_MAJOR;
	version[1] = DM_VERSION_MINOR;
	version[2] = DM_VERSION_PATCHLEVEL;
	if (copy_to_user(user->version, version, sizeof(version)))
		return -EFAULT;

	return r;
}

static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param)
{
	struct dm_ioctl tmp, *dmi;
1549
	int secure_data;
L
Linus Torvalds 已提交
1550

M
Milan Broz 已提交
1551
	if (copy_from_user(&tmp, user, sizeof(tmp) - sizeof(tmp.data)))
L
Linus Torvalds 已提交
1552 1553
		return -EFAULT;

M
Milan Broz 已提交
1554
	if (tmp.data_size < (sizeof(tmp) - sizeof(tmp.data)))
L
Linus Torvalds 已提交
1555 1556
		return -EINVAL;

1557 1558
	secure_data = tmp.flags & DM_SECURE_DATA_FLAG;

J
Jesper Juhl 已提交
1559
	dmi = vmalloc(tmp.data_size);
1560 1561 1562
	if (!dmi) {
		if (secure_data && clear_user(user, tmp.data_size))
			return -EFAULT;
L
Linus Torvalds 已提交
1563
		return -ENOMEM;
1564
	}
L
Linus Torvalds 已提交
1565

1566 1567
	if (copy_from_user(dmi, user, tmp.data_size))
		goto bad;
L
Linus Torvalds 已提交
1568

1569 1570 1571 1572
	/* Wipe the user buffer so we do not return it to userspace */
	if (secure_data && clear_user(user, tmp.data_size))
		goto bad;

L
Linus Torvalds 已提交
1573 1574
	*param = dmi;
	return 0;
1575 1576

bad:
1577 1578
	if (secure_data)
		memset(dmi, 0, tmp.data_size);
1579 1580
	vfree(dmi);
	return -EFAULT;
L
Linus Torvalds 已提交
1581 1582 1583 1584 1585 1586
}

static int validate_params(uint cmd, struct dm_ioctl *param)
{
	/* Always clear this flag */
	param->flags &= ~DM_BUFFER_FULL_FLAG;
1587
	param->flags &= ~DM_UEVENT_GENERATED_FLAG;
1588
	param->flags &= ~DM_SECURE_DATA_FLAG;
L
Linus Torvalds 已提交
1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612

	/* Ignores parameters */
	if (cmd == DM_REMOVE_ALL_CMD ||
	    cmd == DM_LIST_DEVICES_CMD ||
	    cmd == DM_LIST_VERSIONS_CMD)
		return 0;

	if ((cmd == DM_DEV_CREATE_CMD)) {
		if (!*param->name) {
			DMWARN("name not supplied when creating device");
			return -EINVAL;
		}
	} else if ((*param->uuid && *param->name)) {
		DMWARN("only supply one of name or uuid, cmd(%u)", cmd);
		return -EINVAL;
	}

	/* Ensure strings are terminated */
	param->name[DM_NAME_LEN - 1] = '\0';
	param->uuid[DM_UUID_LEN - 1] = '\0';

	return 0;
}

A
Alasdair G Kergon 已提交
1613
static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
L
Linus Torvalds 已提交
1614 1615
{
	int r = 0;
1616
	int wipe_buffer;
L
Linus Torvalds 已提交
1617
	unsigned int cmd;
A
Andrew Morton 已提交
1618
	struct dm_ioctl *uninitialized_var(param);
L
Linus Torvalds 已提交
1619
	ioctl_fn fn = NULL;
1620
	size_t input_param_size;
L
Linus Torvalds 已提交
1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661

	/* only root can play with this */
	if (!capable(CAP_SYS_ADMIN))
		return -EACCES;

	if (_IOC_TYPE(command) != DM_IOCTL)
		return -ENOTTY;

	cmd = _IOC_NR(command);

	/*
	 * Check the interface version passed in.  This also
	 * writes out the kernel's interface version.
	 */
	r = check_version(cmd, user);
	if (r)
		return r;

	/*
	 * Nothing more to do for the version command.
	 */
	if (cmd == DM_VERSION_CMD)
		return 0;

	fn = lookup_ioctl(cmd);
	if (!fn) {
		DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);
		return -ENOTTY;
	}

	/*
	 * Trying to avoid low memory issues when a device is
	 * suspended.
	 */
	current->flags |= PF_MEMALLOC;

	/*
	 * Copy the parameters into kernel space.
	 */
	r = copy_params(user, &param);

1662 1663 1664 1665
	current->flags &= ~PF_MEMALLOC;

	if (r)
		return r;
L
Linus Torvalds 已提交
1666

1667 1668 1669
	input_param_size = param->data_size;
	wipe_buffer = param->flags & DM_SECURE_DATA_FLAG;

L
Linus Torvalds 已提交
1670 1671 1672 1673 1674
	r = validate_params(cmd, param);
	if (r)
		goto out;

	param->data_size = sizeof(*param);
1675
	r = fn(param, input_param_size);
L
Linus Torvalds 已提交
1676 1677 1678 1679 1680 1681 1682

	/*
	 * Copy the results back to userland.
	 */
	if (!r && copy_to_user(user, param, param->data_size))
		r = -EFAULT;

1683
out:
1684 1685 1686
	if (wipe_buffer)
		memset(param, 0, input_param_size);

1687
	vfree(param);
L
Linus Torvalds 已提交
1688 1689 1690
	return r;
}

A
Alasdair G Kergon 已提交
1691 1692 1693 1694 1695
static long dm_ctl_ioctl(struct file *file, uint command, ulong u)
{
	return (long)ctl_ioctl(command, (struct dm_ioctl __user *)u);
}

M
Milan Broz 已提交
1696 1697 1698 1699 1700 1701 1702 1703 1704
#ifdef CONFIG_COMPAT
static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u)
{
	return (long)dm_ctl_ioctl(file, command, (ulong) compat_ptr(u));
}
#else
#define dm_compat_ctl_ioctl NULL
#endif

1705
static const struct file_operations _ctl_fops = {
A
Arnd Bergmann 已提交
1706
	.open = nonseekable_open,
A
Alasdair G Kergon 已提交
1707
	.unlocked_ioctl	 = dm_ctl_ioctl,
M
Milan Broz 已提交
1708
	.compat_ioctl = dm_compat_ctl_ioctl,
L
Linus Torvalds 已提交
1709
	.owner	 = THIS_MODULE,
1710
	.llseek  = noop_llseek,
L
Linus Torvalds 已提交
1711 1712 1713
};

static struct miscdevice _dm_misc = {
P
Peter Rajnoha 已提交
1714
	.minor		= MAPPER_CTRL_MINOR,
L
Linus Torvalds 已提交
1715
	.name  		= DM_NAME,
P
Peter Rajnoha 已提交
1716
	.nodename	= DM_DIR "/" DM_CONTROL_NODE,
L
Linus Torvalds 已提交
1717 1718 1719
	.fops  		= &_ctl_fops
};

P
Peter Rajnoha 已提交
1720 1721 1722
MODULE_ALIAS_MISCDEV(MAPPER_CTRL_MINOR);
MODULE_ALIAS("devname:" DM_DIR "/" DM_CONTROL_NODE);

L
Linus Torvalds 已提交
1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753
/*
 * Create misc character device and link to DM_DIR/control.
 */
int __init dm_interface_init(void)
{
	int r;

	r = dm_hash_init();
	if (r)
		return r;

	r = misc_register(&_dm_misc);
	if (r) {
		DMERR("misc_register failed for control device");
		dm_hash_exit();
		return r;
	}

	DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
	       DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
	       DM_DRIVER_EMAIL);
	return 0;
}

void dm_interface_exit(void)
{
	if (misc_deregister(&_dm_misc) < 0)
		DMERR("misc_deregister failed for control device");

	dm_hash_exit();
}
M
Mike Anderson 已提交
1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768

/**
 * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers
 * @md: Pointer to mapped_device
 * @name: Buffer (size DM_NAME_LEN) for name
 * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined
 */
int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
{
	int r = 0;
	struct hash_cell *hc;

	if (!md)
		return -ENXIO;

M
Mikulas Patocka 已提交
1769
	mutex_lock(&dm_hash_cells_mutex);
M
Mike Anderson 已提交
1770 1771 1772 1773 1774 1775
	hc = dm_get_mdptr(md);
	if (!hc || hc->md != md) {
		r = -ENXIO;
		goto out;
	}

1776 1777 1778 1779
	if (name)
		strcpy(name, hc->name);
	if (uuid)
		strcpy(uuid, hc->uuid ? : "");
M
Mike Anderson 已提交
1780 1781

out:
M
Mikulas Patocka 已提交
1782
	mutex_unlock(&dm_hash_cells_mutex);
M
Mike Anderson 已提交
1783 1784 1785

	return r;
}