1/*
   2 * Copyright (C) 2001, 2002 Sistina Software (UK) Limited.
   3 * Copyright (C) 2004 - 2006 Red Hat, Inc. All rights reserved.
   4 *
   5 * This file is released under the GPL.
   6 */
   7
   8#include "dm.h"
   9
  10#include <linux/module.h>
  11#include <linux/vmalloc.h>
  12#include <linux/miscdevice.h>
  13#include <linux/init.h>
  14#include <linux/wait.h>
  15#include <linux/slab.h>
  16#include <linux/dm-ioctl.h>
  17#include <linux/hdreg.h>
  18#include <linux/compat.h>
  19
  20#include <asm/uaccess.h>
  21
  22#define DM_MSG_PREFIX "ioctl"
  23#define DM_DRIVER_EMAIL "dm-devel@redhat.com"
  24
  25/*-----------------------------------------------------------------
  26 * The ioctl interface needs to be able to look up devices by
  27 * name or uuid.
  28 *---------------------------------------------------------------*/
  29struct hash_cell {
  30	struct list_head name_list;
  31	struct list_head uuid_list;
  32
  33	char *name;
  34	char *uuid;
  35	struct mapped_device *md;
  36	struct dm_table *new_map;
  37};
  38
 
 
 
 
 
 
 
 
  39struct vers_iter {
  40    size_t param_size;
  41    struct dm_target_versions *vers, *old_vers;
  42    char *end;
  43    uint32_t flags;
  44};
  45
  46
  47#define NUM_BUCKETS 64
  48#define MASK_BUCKETS (NUM_BUCKETS - 1)
  49static struct list_head _name_buckets[NUM_BUCKETS];
  50static struct list_head _uuid_buckets[NUM_BUCKETS];
  51
  52static void dm_hash_remove_all(int keep_open_devices);
  53
  54/*
  55 * Guards access to both hash tables.
  56 */
  57static DECLARE_RWSEM(_hash_lock);
  58
  59/*
  60 * Protects use of mdptr to obtain hash cell name and uuid from mapped device.
  61 */
  62static DEFINE_MUTEX(dm_hash_cells_mutex);
  63
  64static void init_buckets(struct list_head *buckets)
  65{
  66	unsigned int i;
  67
  68	for (i = 0; i < NUM_BUCKETS; i++)
  69		INIT_LIST_HEAD(buckets + i);
  70}
  71
  72static int dm_hash_init(void)
  73{
  74	init_buckets(_name_buckets);
  75	init_buckets(_uuid_buckets);
  76	return 0;
  77}
  78
  79static void dm_hash_exit(void)
  80{
  81	dm_hash_remove_all(0);
  82}
  83
  84/*-----------------------------------------------------------------
  85 * Hash function:
  86 * We're not really concerned with the str hash function being
  87 * fast since it's only used by the ioctl interface.
  88 *---------------------------------------------------------------*/
  89static unsigned int hash_str(const char *str)
  90{
  91	const unsigned int hash_mult = 2654435387U;
  92	unsigned int h = 0;
  93
  94	while (*str)
  95		h = (h + (unsigned int) *str++) * hash_mult;
  96
  97	return h & MASK_BUCKETS;
  98}
  99
 100/*-----------------------------------------------------------------
 101 * Code for looking up a device by name
 102 *---------------------------------------------------------------*/
 103static struct hash_cell *__get_name_cell(const char *str)
 104{
 105	struct hash_cell *hc;
 106	unsigned int h = hash_str(str);
 107
 108	list_for_each_entry (hc, _name_buckets + h, name_list)
 109		if (!strcmp(hc->name, str)) {
 110			dm_get(hc->md);
 111			return hc;
 112		}
 113
 114	return NULL;
 115}
 116
 117static struct hash_cell *__get_uuid_cell(const char *str)
 118{
 119	struct hash_cell *hc;
 120	unsigned int h = hash_str(str);
 121
 122	list_for_each_entry (hc, _uuid_buckets + h, uuid_list)
 123		if (!strcmp(hc->uuid, str)) {
 124			dm_get(hc->md);
 125			return hc;
 126		}
 127
 128	return NULL;
 129}
 130
 131static struct hash_cell *__get_dev_cell(uint64_t dev)
 132{
 133	struct mapped_device *md;
 134	struct hash_cell *hc;
 135
 136	md = dm_get_md(huge_decode_dev(dev));
 137	if (!md)
 138		return NULL;
 139
 140	hc = dm_get_mdptr(md);
 141	if (!hc) {
 142		dm_put(md);
 143		return NULL;
 144	}
 145
 146	return hc;
 147}
 148
 149/*-----------------------------------------------------------------
 150 * Inserting, removing and renaming a device.
 151 *---------------------------------------------------------------*/
 152static struct hash_cell *alloc_cell(const char *name, const char *uuid,
 153				    struct mapped_device *md)
 154{
 155	struct hash_cell *hc;
 156
 157	hc = kmalloc(sizeof(*hc), GFP_KERNEL);
 158	if (!hc)
 159		return NULL;
 160
 161	hc->name = kstrdup(name, GFP_KERNEL);
 162	if (!hc->name) {
 163		kfree(hc);
 164		return NULL;
 165	}
 166
 167	if (!uuid)
 168		hc->uuid = NULL;
 169
 170	else {
 171		hc->uuid = kstrdup(uuid, GFP_KERNEL);
 172		if (!hc->uuid) {
 173			kfree(hc->name);
 174			kfree(hc);
 175			return NULL;
 176		}
 177	}
 178
 179	INIT_LIST_HEAD(&hc->name_list);
 180	INIT_LIST_HEAD(&hc->uuid_list);
 181	hc->md = md;
 182	hc->new_map = NULL;
 183	return hc;
 184}
 185
 186static void free_cell(struct hash_cell *hc)
 187{
 188	if (hc) {
 189		kfree(hc->name);
 190		kfree(hc->uuid);
 191		kfree(hc);
 192	}
 193}
 194
 195/*
 196 * The kdev_t and uuid of a device can never change once it is
 197 * initially inserted.
 198 */
 199static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md)
 200{
 201	struct hash_cell *cell, *hc;
 202
 203	/*
 204	 * Allocate the new cells.
 205	 */
 206	cell = alloc_cell(name, uuid, md);
 207	if (!cell)
 208		return -ENOMEM;
 209
 210	/*
 211	 * Insert the cell into both hash tables.
 212	 */
 213	down_write(&_hash_lock);
 214	hc = __get_name_cell(name);
 215	if (hc) {
 216		dm_put(hc->md);
 217		goto bad;
 218	}
 219
 220	list_add(&cell->name_list, _name_buckets + hash_str(name));
 221
 222	if (uuid) {
 223		hc = __get_uuid_cell(uuid);
 224		if (hc) {
 225			list_del(&cell->name_list);
 226			dm_put(hc->md);
 227			goto bad;
 228		}
 229		list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid));
 230	}
 231	dm_get(md);
 232	mutex_lock(&dm_hash_cells_mutex);
 233	dm_set_mdptr(md, cell);
 234	mutex_unlock(&dm_hash_cells_mutex);
 235	up_write(&_hash_lock);
 236
 237	return 0;
 238
 239 bad:
 240	up_write(&_hash_lock);
 241	free_cell(cell);
 242	return -EBUSY;
 243}
 244
 245static void __hash_remove(struct hash_cell *hc)
 246{
 247	struct dm_table *table;
 
 248
 249	/* remove from the dev hash */
 250	list_del(&hc->uuid_list);
 251	list_del(&hc->name_list);
 252	mutex_lock(&dm_hash_cells_mutex);
 253	dm_set_mdptr(hc->md, NULL);
 254	mutex_unlock(&dm_hash_cells_mutex);
 255
 256	table = dm_get_live_table(hc->md);
 257	if (table) {
 258		dm_table_event(table);
 259		dm_table_put(table);
 260	}
 261
 
 262	if (hc->new_map)
 263		dm_table_destroy(hc->new_map);
 264	dm_put(hc->md);
 265	free_cell(hc);
 
 
 266}
 267
 268static void dm_hash_remove_all(int keep_open_devices)
 269{
 270	int i, dev_skipped;
 271	struct hash_cell *hc;
 272	struct mapped_device *md;
 
 273
 274retry:
 275	dev_skipped = 0;
 276
 277	down_write(&_hash_lock);
 278
 279	for (i = 0; i < NUM_BUCKETS; i++) {
 280		list_for_each_entry(hc, _name_buckets + i, name_list) {
 281			md = hc->md;
 282			dm_get(md);
 283
 284			if (keep_open_devices && dm_lock_for_deletion(md)) {
 
 285				dm_put(md);
 286				dev_skipped++;
 287				continue;
 288			}
 289
 290			__hash_remove(hc);
 291
 292			up_write(&_hash_lock);
 293
 
 
 
 
 294			dm_put(md);
 295			if (likely(keep_open_devices))
 296				dm_destroy(md);
 297			else
 298				dm_destroy_immediate(md);
 299
 300			/*
 301			 * Some mapped devices may be using other mapped
 302			 * devices, so repeat until we make no further
 303			 * progress.  If a new mapped device is created
 304			 * here it will also get removed.
 305			 */
 306			goto retry;
 307		}
 308	}
 309
 310	up_write(&_hash_lock);
 311
 312	if (dev_skipped)
 313		DMWARN("remove_all left %d open device(s)", dev_skipped);
 314}
 315
 316/*
 317 * Set the uuid of a hash_cell that isn't already set.
 318 */
 319static void __set_cell_uuid(struct hash_cell *hc, char *new_uuid)
 320{
 321	mutex_lock(&dm_hash_cells_mutex);
 322	hc->uuid = new_uuid;
 323	mutex_unlock(&dm_hash_cells_mutex);
 324
 325	list_add(&hc->uuid_list, _uuid_buckets + hash_str(new_uuid));
 326}
 327
 328/*
 329 * Changes the name of a hash_cell and returns the old name for
 330 * the caller to free.
 331 */
 332static char *__change_cell_name(struct hash_cell *hc, char *new_name)
 333{
 334	char *old_name;
 335
 336	/*
 337	 * Rename and move the name cell.
 338	 */
 339	list_del(&hc->name_list);
 340	old_name = hc->name;
 341
 342	mutex_lock(&dm_hash_cells_mutex);
 343	hc->name = new_name;
 344	mutex_unlock(&dm_hash_cells_mutex);
 345
 346	list_add(&hc->name_list, _name_buckets + hash_str(new_name));
 347
 348	return old_name;
 349}
 350
 351static struct mapped_device *dm_hash_rename(struct dm_ioctl *param,
 352					    const char *new)
 353{
 354	char *new_data, *old_name = NULL;
 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;
 
 359
 360	/*
 361	 * duplicate new.
 362	 */
 363	new_data = kstrdup(new, GFP_KERNEL);
 364	if (!new_data)
 365		return ERR_PTR(-ENOMEM);
 366
 367	down_write(&_hash_lock);
 368
 369	/*
 370	 * Is new free ?
 371	 */
 372	if (change_uuid)
 373		hc = __get_uuid_cell(new);
 374	else
 375		hc = __get_name_cell(new);
 376
 377	if (hc) {
 378		DMWARN("Unable to change %s on mapped device %s to one that "
 379		       "already exists: %s",
 380		       change_uuid ? "uuid" : "name",
 381		       param->name, new);
 382		dm_put(hc->md);
 383		up_write(&_hash_lock);
 384		kfree(new_data);
 385		return ERR_PTR(-EBUSY);
 386	}
 387
 388	/*
 389	 * Is there such a device as 'old' ?
 390	 */
 391	hc = __get_name_cell(param->name);
 392	if (!hc) {
 393		DMWARN("Unable to rename non-existent device, %s to %s%s",
 394		       param->name, change_uuid ? "uuid " : "", new);
 395		up_write(&_hash_lock);
 396		kfree(new_data);
 397		return ERR_PTR(-ENXIO);
 398	}
 399
 400	/*
 401	 * Does this device already have a uuid?
 402	 */
 403	if (change_uuid && hc->uuid) {
 404		DMWARN("Unable to change uuid of mapped device %s to %s "
 405		       "because uuid is already set to %s",
 406		       param->name, new, hc->uuid);
 407		dm_put(hc->md);
 408		up_write(&_hash_lock);
 409		kfree(new_data);
 410		return ERR_PTR(-EINVAL);
 411	}
 412
 413	if (change_uuid)
 414		__set_cell_uuid(hc, new_data);
 415	else
 416		old_name = __change_cell_name(hc, new_data);
 417
 418	/*
 419	 * Wake up any dm event waiters.
 420	 */
 421	table = dm_get_live_table(hc->md);
 422	if (table) {
 423		dm_table_event(table);
 424		dm_table_put(table);
 425	}
 426
 427	if (!dm_kobject_uevent(hc->md, KOBJ_CHANGE, param->event_nr))
 428		param->flags |= DM_UEVENT_GENERATED_FLAG;
 429
 430	md = hc->md;
 431	up_write(&_hash_lock);
 432	kfree(old_name);
 433
 434	return md;
 435}
 436
 
 
 
 
 
 437/*-----------------------------------------------------------------
 438 * Implementation of the ioctl commands
 439 *---------------------------------------------------------------*/
 440/*
 441 * All the ioctl commands get dispatched to functions with this
 442 * prototype.
 443 */
 444typedef int (*ioctl_fn)(struct dm_ioctl *param, size_t param_size);
 445
 446static int remove_all(struct dm_ioctl *param, size_t param_size)
 447{
 448	dm_hash_remove_all(1);
 449	param->data_size = 0;
 450	return 0;
 451}
 452
 453/*
 454 * Round up the ptr to an 8-byte boundary.
 455 */
 456#define ALIGN_MASK 7
 457static inline void *align_ptr(void *ptr)
 458{
 459	return (void *) (((size_t) (ptr + ALIGN_MASK)) & ~ALIGN_MASK);
 460}
 461
 462/*
 463 * Retrieves the data payload buffer from an already allocated
 464 * struct dm_ioctl.
 465 */
 466static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
 467			       size_t *len)
 468{
 469	param->data_start = align_ptr(param + 1) - (void *) param;
 470
 471	if (param->data_start < param_size)
 472		*len = param_size - param->data_start;
 473	else
 474		*len = 0;
 475
 476	return ((void *) param) + param->data_start;
 477}
 478
 479static int list_devices(struct dm_ioctl *param, size_t param_size)
 480{
 481	unsigned int i;
 482	struct hash_cell *hc;
 483	size_t len, needed = 0;
 484	struct gendisk *disk;
 485	struct dm_name_list *nl, *old_nl = NULL;
 486
 487	down_write(&_hash_lock);
 488
 489	/*
 490	 * Loop through all the devices working out how much
 491	 * space we need.
 492	 */
 493	for (i = 0; i < NUM_BUCKETS; i++) {
 494		list_for_each_entry (hc, _name_buckets + i, name_list) {
 495			needed += sizeof(struct dm_name_list);
 496			needed += strlen(hc->name) + 1;
 497			needed += ALIGN_MASK;
 498		}
 499	}
 500
 501	/*
 502	 * Grab our output buffer.
 503	 */
 504	nl = get_result_buffer(param, param_size, &len);
 505	if (len < needed) {
 506		param->flags |= DM_BUFFER_FULL_FLAG;
 507		goto out;
 508	}
 509	param->data_size = param->data_start + needed;
 510
 511	nl->dev = 0;	/* Flags no data */
 512
 513	/*
 514	 * Now loop through filling out the names.
 515	 */
 516	for (i = 0; i < NUM_BUCKETS; i++) {
 517		list_for_each_entry (hc, _name_buckets + i, name_list) {
 518			if (old_nl)
 519				old_nl->next = (uint32_t) ((void *) nl -
 520							   (void *) old_nl);
 521			disk = dm_disk(hc->md);
 522			nl->dev = huge_encode_dev(disk_devt(disk));
 523			nl->next = 0;
 524			strcpy(nl->name, hc->name);
 525
 526			old_nl = nl;
 527			nl = align_ptr(((void *) ++nl) + strlen(hc->name) + 1);
 528		}
 529	}
 530
 531 out:
 532	up_write(&_hash_lock);
 533	return 0;
 534}
 535
 536static void list_version_get_needed(struct target_type *tt, void *needed_param)
 537{
 538    size_t *needed = needed_param;
 539
 540    *needed += sizeof(struct dm_target_versions);
 541    *needed += strlen(tt->name);
 542    *needed += ALIGN_MASK;
 543}
 544
 545static void list_version_get_info(struct target_type *tt, void *param)
 546{
 547    struct vers_iter *info = param;
 548
 549    /* Check space - it might have changed since the first iteration */
 550    if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 >
 551	info->end) {
 552
 553	info->flags = DM_BUFFER_FULL_FLAG;
 554	return;
 555    }
 556
 557    if (info->old_vers)
 558	info->old_vers->next = (uint32_t) ((void *)info->vers -
 559					   (void *)info->old_vers);
 560    info->vers->version[0] = tt->version[0];
 561    info->vers->version[1] = tt->version[1];
 562    info->vers->version[2] = tt->version[2];
 563    info->vers->next = 0;
 564    strcpy(info->vers->name, tt->name);
 565
 566    info->old_vers = info->vers;
 567    info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1);
 568}
 569
 570static int list_versions(struct dm_ioctl *param, size_t param_size)
 571{
 572	size_t len, needed = 0;
 573	struct dm_target_versions *vers;
 574	struct vers_iter iter_info;
 575
 576	/*
 577	 * Loop through all the devices working out how much
 578	 * space we need.
 579	 */
 580	dm_target_iterate(list_version_get_needed, &needed);
 581
 582	/*
 583	 * Grab our output buffer.
 584	 */
 585	vers = get_result_buffer(param, param_size, &len);
 586	if (len < needed) {
 587		param->flags |= DM_BUFFER_FULL_FLAG;
 588		goto out;
 589	}
 590	param->data_size = param->data_start + needed;
 591
 592	iter_info.param_size = param_size;
 593	iter_info.old_vers = NULL;
 594	iter_info.vers = vers;
 595	iter_info.flags = 0;
 596	iter_info.end = (char *)vers+len;
 597
 598	/*
 599	 * Now loop through filling out the names & versions.
 600	 */
 601	dm_target_iterate(list_version_get_info, &iter_info);
 602	param->flags |= iter_info.flags;
 603
 604 out:
 605	return 0;
 606}
 607
 608static int check_name(const char *name)
 609{
 610	if (strchr(name, '/')) {
 611		DMWARN("invalid device name");
 612		return -EINVAL;
 613	}
 614
 615	return 0;
 616}
 617
 618/*
 619 * On successful return, the caller must not attempt to acquire
 620 * _hash_lock without first calling dm_table_put, because dm_table_destroy
 621 * waits for this dm_table_put and could be called under this lock.
 622 */
 623static struct dm_table *dm_get_inactive_table(struct mapped_device *md)
 624{
 625	struct hash_cell *hc;
 626	struct dm_table *table = NULL;
 627
 
 
 
 628	down_read(&_hash_lock);
 629	hc = dm_get_mdptr(md);
 630	if (!hc || hc->md != md) {
 631		DMWARN("device has been removed from the dev hash table.");
 632		goto out;
 633	}
 634
 635	table = hc->new_map;
 636	if (table)
 637		dm_table_get(table);
 638
 639out:
 640	up_read(&_hash_lock);
 641
 642	return table;
 643}
 644
 645static struct dm_table *dm_get_live_or_inactive_table(struct mapped_device *md,
 646						      struct dm_ioctl *param)
 
 647{
 648	return (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) ?
 649		dm_get_inactive_table(md) : dm_get_live_table(md);
 650}
 651
 652/*
 653 * Fills in a dm_ioctl structure, ready for sending back to
 654 * userland.
 655 */
 656static void __dev_status(struct mapped_device *md, struct dm_ioctl *param)
 657{
 658	struct gendisk *disk = dm_disk(md);
 659	struct dm_table *table;
 
 660
 661	param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
 662			  DM_ACTIVE_PRESENT_FLAG);
 663
 664	if (dm_suspended_md(md))
 665		param->flags |= DM_SUSPEND_FLAG;
 666
 
 
 
 667	param->dev = huge_encode_dev(disk_devt(disk));
 668
 669	/*
 670	 * Yes, this will be out of date by the time it gets back
 671	 * to userland, but it is still very useful for
 672	 * debugging.
 673	 */
 674	param->open_count = dm_open_count(md);
 675
 676	param->event_nr = dm_get_event_nr(md);
 677	param->target_count = 0;
 678
 679	table = dm_get_live_table(md);
 680	if (table) {
 681		if (!(param->flags & DM_QUERY_INACTIVE_TABLE_FLAG)) {
 682			if (get_disk_ro(disk))
 683				param->flags |= DM_READONLY_FLAG;
 684			param->target_count = dm_table_get_num_targets(table);
 685		}
 686		dm_table_put(table);
 687
 688		param->flags |= DM_ACTIVE_PRESENT_FLAG;
 689	}
 
 690
 691	if (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) {
 692		table = dm_get_inactive_table(md);
 
 693		if (table) {
 694			if (!(dm_table_get_mode(table) & FMODE_WRITE))
 695				param->flags |= DM_READONLY_FLAG;
 696			param->target_count = dm_table_get_num_targets(table);
 697			dm_table_put(table);
 698		}
 
 699	}
 700}
 701
 702static int dev_create(struct dm_ioctl *param, size_t param_size)
 703{
 704	int r, m = DM_ANY_MINOR;
 705	struct mapped_device *md;
 706
 707	r = check_name(param->name);
 708	if (r)
 709		return r;
 710
 711	if (param->flags & DM_PERSISTENT_DEV_FLAG)
 712		m = MINOR(huge_decode_dev(param->dev));
 713
 714	r = dm_create(m, &md);
 715	if (r)
 716		return r;
 717
 718	r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
 719	if (r) {
 720		dm_put(md);
 721		dm_destroy(md);
 722		return r;
 723	}
 724
 725	param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
 726
 727	__dev_status(md, param);
 728
 729	dm_put(md);
 730
 731	return 0;
 732}
 733
 734/*
 735 * Always use UUID for lookups if it's present, otherwise use name or dev.
 736 */
 737static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
 738{
 739	struct hash_cell *hc = NULL;
 740
 741	if (*param->uuid) {
 742		if (*param->name || param->dev)
 743			return NULL;
 744
 745		hc = __get_uuid_cell(param->uuid);
 746		if (!hc)
 747			return NULL;
 748	} else if (*param->name) {
 749		if (param->dev)
 750			return NULL;
 751
 752		hc = __get_name_cell(param->name);
 753		if (!hc)
 754			return NULL;
 755	} else if (param->dev) {
 756		hc = __get_dev_cell(param->dev);
 757		if (!hc)
 758			return NULL;
 759	} else
 760		return NULL;
 761
 762	/*
 763	 * Sneakily write in both the name and the uuid
 764	 * while we have the cell.
 765	 */
 766	strlcpy(param->name, hc->name, sizeof(param->name));
 767	if (hc->uuid)
 768		strlcpy(param->uuid, hc->uuid, sizeof(param->uuid));
 769	else
 770		param->uuid[0] = '\0';
 771
 772	if (hc->new_map)
 773		param->flags |= DM_INACTIVE_PRESENT_FLAG;
 774	else
 775		param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
 776
 777	return hc;
 778}
 779
 780static struct mapped_device *find_device(struct dm_ioctl *param)
 781{
 782	struct hash_cell *hc;
 783	struct mapped_device *md = NULL;
 784
 785	down_read(&_hash_lock);
 786	hc = __find_device_hash_cell(param);
 787	if (hc)
 788		md = hc->md;
 789	up_read(&_hash_lock);
 790
 791	return md;
 792}
 793
 794static int dev_remove(struct dm_ioctl *param, size_t param_size)
 795{
 796	struct hash_cell *hc;
 797	struct mapped_device *md;
 798	int r;
 
 799
 800	down_write(&_hash_lock);
 801	hc = __find_device_hash_cell(param);
 802
 803	if (!hc) {
 804		DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
 805		up_write(&_hash_lock);
 806		return -ENXIO;
 807	}
 808
 809	md = hc->md;
 810
 811	/*
 812	 * Ensure the device is not open and nothing further can open it.
 813	 */
 814	r = dm_lock_for_deletion(md);
 815	if (r) {
 
 
 
 
 
 816		DMDEBUG_LIMIT("unable to remove open device %s", hc->name);
 817		up_write(&_hash_lock);
 818		dm_put(md);
 819		return r;
 820	}
 821
 822	__hash_remove(hc);
 823	up_write(&_hash_lock);
 824
 
 
 
 
 
 
 
 825	if (!dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr))
 826		param->flags |= DM_UEVENT_GENERATED_FLAG;
 827
 828	dm_put(md);
 829	dm_destroy(md);
 830	return 0;
 831}
 832
 833/*
 834 * Check a string doesn't overrun the chunk of
 835 * memory we copied from userland.
 836 */
 837static int invalid_str(char *str, void *end)
 838{
 839	while ((void *) str < end)
 840		if (!*str++)
 841			return 0;
 842
 843	return -EINVAL;
 844}
 845
 846static int dev_rename(struct dm_ioctl *param, size_t param_size)
 847{
 848	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;
 852
 853	if (new_data < param->data ||
 854	    invalid_str(new_data, (void *) param + param_size) ||
 855	    strlen(new_data) > (change_uuid ? DM_UUID_LEN - 1 : DM_NAME_LEN - 1)) {
 856		DMWARN("Invalid new mapped device name or uuid string supplied.");
 857		return -EINVAL;
 858	}
 859
 860	if (!change_uuid) {
 861		r = check_name(new_data);
 862		if (r)
 863			return r;
 864	}
 865
 866	md = dm_hash_rename(param, new_data);
 867	if (IS_ERR(md))
 868		return PTR_ERR(md);
 869
 870	__dev_status(md, param);
 871	dm_put(md);
 872
 873	return 0;
 874}
 875
 876static int dev_set_geometry(struct dm_ioctl *param, size_t param_size)
 877{
 878	int r = -EINVAL, x;
 879	struct mapped_device *md;
 880	struct hd_geometry geometry;
 881	unsigned long indata[4];
 882	char *geostr = (char *) param + param->data_start;
 
 883
 884	md = find_device(param);
 885	if (!md)
 886		return -ENXIO;
 887
 888	if (geostr < param->data ||
 889	    invalid_str(geostr, (void *) param + param_size)) {
 890		DMWARN("Invalid geometry supplied.");
 891		goto out;
 892	}
 893
 894	x = sscanf(geostr, "%lu %lu %lu %lu", indata,
 895		   indata + 1, indata + 2, indata + 3);
 896
 897	if (x != 4) {
 898		DMWARN("Unable to interpret geometry settings.");
 899		goto out;
 900	}
 901
 902	if (indata[0] > 65535 || indata[1] > 255 ||
 903	    indata[2] > 255 || indata[3] > ULONG_MAX) {
 904		DMWARN("Geometry exceeds range limits.");
 905		goto out;
 906	}
 907
 908	geometry.cylinders = indata[0];
 909	geometry.heads = indata[1];
 910	geometry.sectors = indata[2];
 911	geometry.start = indata[3];
 912
 913	r = dm_set_geometry(md, &geometry);
 914
 915	param->data_size = 0;
 916
 917out:
 918	dm_put(md);
 919	return r;
 920}
 921
 922static int do_suspend(struct dm_ioctl *param)
 923{
 924	int r = 0;
 925	unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
 926	struct mapped_device *md;
 927
 928	md = find_device(param);
 929	if (!md)
 930		return -ENXIO;
 931
 932	if (param->flags & DM_SKIP_LOCKFS_FLAG)
 933		suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
 934	if (param->flags & DM_NOFLUSH_FLAG)
 935		suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
 936
 937	if (!dm_suspended_md(md)) {
 938		r = dm_suspend(md, suspend_flags);
 939		if (r)
 940			goto out;
 941	}
 942
 943	__dev_status(md, param);
 944
 945out:
 946	dm_put(md);
 947
 948	return r;
 949}
 950
 951static int do_resume(struct dm_ioctl *param)
 952{
 953	int r = 0;
 954	unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
 955	struct hash_cell *hc;
 956	struct mapped_device *md;
 957	struct dm_table *new_map, *old_map = NULL;
 958
 959	down_write(&_hash_lock);
 960
 961	hc = __find_device_hash_cell(param);
 962	if (!hc) {
 963		DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
 964		up_write(&_hash_lock);
 965		return -ENXIO;
 966	}
 967
 968	md = hc->md;
 969
 970	new_map = hc->new_map;
 971	hc->new_map = NULL;
 972	param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
 973
 974	up_write(&_hash_lock);
 975
 976	/* Do we need to load a new map ? */
 977	if (new_map) {
 978		/* Suspend if it isn't already suspended */
 979		if (param->flags & DM_SKIP_LOCKFS_FLAG)
 980			suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
 981		if (param->flags & DM_NOFLUSH_FLAG)
 982			suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
 983		if (!dm_suspended_md(md))
 984			dm_suspend(md, suspend_flags);
 985
 986		old_map = dm_swap_table(md, new_map);
 987		if (IS_ERR(old_map)) {
 
 988			dm_table_destroy(new_map);
 989			dm_put(md);
 990			return PTR_ERR(old_map);
 991		}
 992
 993		if (dm_table_get_mode(new_map) & FMODE_WRITE)
 994			set_disk_ro(dm_disk(md), 0);
 995		else
 996			set_disk_ro(dm_disk(md), 1);
 997	}
 998
 999	if (dm_suspended_md(md)) {
1000		r = dm_resume(md);
1001		if (!r && !dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr))
1002			param->flags |= DM_UEVENT_GENERATED_FLAG;
1003	}
1004
 
 
 
 
1005	if (old_map)
1006		dm_table_destroy(old_map);
1007
1008	if (!r)
1009		__dev_status(md, param);
1010
1011	dm_put(md);
1012	return r;
1013}
1014
1015/*
1016 * Set or unset the suspension state of a device.
1017 * If the device already is in the requested state we just return its status.
1018 */
1019static int dev_suspend(struct dm_ioctl *param, size_t param_size)
1020{
1021	if (param->flags & DM_SUSPEND_FLAG)
1022		return do_suspend(param);
1023
1024	return do_resume(param);
1025}
1026
1027/*
1028 * Copies device info back to user space, used by
1029 * the create and info ioctls.
1030 */
1031static int dev_status(struct dm_ioctl *param, size_t param_size)
1032{
1033	struct mapped_device *md;
1034
1035	md = find_device(param);
1036	if (!md)
1037		return -ENXIO;
1038
1039	__dev_status(md, param);
1040	dm_put(md);
1041
1042	return 0;
1043}
1044
1045/*
1046 * Build up the status struct for each target
1047 */
1048static void retrieve_status(struct dm_table *table,
1049			    struct dm_ioctl *param, size_t param_size)
1050{
1051	unsigned int i, num_targets;
1052	struct dm_target_spec *spec;
1053	char *outbuf, *outptr;
1054	status_type_t type;
1055	size_t remaining, len, used = 0;
 
1056
1057	outptr = outbuf = get_result_buffer(param, param_size, &len);
1058
1059	if (param->flags & DM_STATUS_TABLE_FLAG)
1060		type = STATUSTYPE_TABLE;
1061	else
1062		type = STATUSTYPE_INFO;
1063
1064	/* Get all the target info */
1065	num_targets = dm_table_get_num_targets(table);
1066	for (i = 0; i < num_targets; i++) {
1067		struct dm_target *ti = dm_table_get_target(table, i);
 
1068
1069		remaining = len - (outptr - outbuf);
1070		if (remaining <= sizeof(struct dm_target_spec)) {
1071			param->flags |= DM_BUFFER_FULL_FLAG;
1072			break;
1073		}
1074
1075		spec = (struct dm_target_spec *) outptr;
1076
1077		spec->status = 0;
1078		spec->sector_start = ti->begin;
1079		spec->length = ti->len;
1080		strncpy(spec->target_type, ti->type->name,
1081			sizeof(spec->target_type));
1082
1083		outptr += sizeof(struct dm_target_spec);
1084		remaining = len - (outptr - outbuf);
1085		if (remaining <= 0) {
1086			param->flags |= DM_BUFFER_FULL_FLAG;
1087			break;
1088		}
1089
1090		/* Get the status/table string from the target driver */
1091		if (ti->type->status) {
1092			if (ti->type->status(ti, type, outptr, remaining)) {
1093				param->flags |= DM_BUFFER_FULL_FLAG;
1094				break;
1095			}
1096		} else
1097			outptr[0] = '\0';
1098
1099		outptr += strlen(outptr) + 1;
 
 
 
 
 
 
1100		used = param->data_start + (outptr - outbuf);
1101
1102		outptr = align_ptr(outptr);
1103		spec->next = outptr - outbuf;
1104	}
1105
1106	if (used)
1107		param->data_size = used;
1108
1109	param->target_count = num_targets;
1110}
1111
1112/*
1113 * Wait for a device to report an event
1114 */
1115static int dev_wait(struct dm_ioctl *param, size_t param_size)
1116{
1117	int r = 0;
1118	struct mapped_device *md;
1119	struct dm_table *table;
 
1120
1121	md = find_device(param);
1122	if (!md)
1123		return -ENXIO;
1124
1125	/*
1126	 * Wait for a notification event
1127	 */
1128	if (dm_wait_event(md, param->event_nr)) {
1129		r = -ERESTARTSYS;
1130		goto out;
1131	}
1132
1133	/*
1134	 * The userland program is going to want to know what
1135	 * changed to trigger the event, so we may as well tell
1136	 * him and save an ioctl.
1137	 */
1138	__dev_status(md, param);
1139
1140	table = dm_get_live_or_inactive_table(md, param);
1141	if (table) {
1142		retrieve_status(table, param, param_size);
1143		dm_table_put(table);
1144	}
1145
1146out:
1147	dm_put(md);
1148
1149	return r;
1150}
1151
1152static inline fmode_t get_mode(struct dm_ioctl *param)
1153{
1154	fmode_t mode = FMODE_READ | FMODE_WRITE;
1155
1156	if (param->flags & DM_READONLY_FLAG)
1157		mode = FMODE_READ;
1158
1159	return mode;
1160}
1161
1162static int next_target(struct dm_target_spec *last, uint32_t next, void *end,
1163		       struct dm_target_spec **spec, char **target_params)
1164{
1165	*spec = (struct dm_target_spec *) ((unsigned char *) last + next);
1166	*target_params = (char *) (*spec + 1);
1167
1168	if (*spec < (last + 1))
1169		return -EINVAL;
1170
1171	return invalid_str(*target_params, end);
1172}
1173
1174static int populate_table(struct dm_table *table,
1175			  struct dm_ioctl *param, size_t param_size)
1176{
1177	int r;
1178	unsigned int i = 0;
1179	struct dm_target_spec *spec = (struct dm_target_spec *) param;
1180	uint32_t next = param->data_start;
1181	void *end = (void *) param + param_size;
1182	char *target_params;
1183
1184	if (!param->target_count) {
1185		DMWARN("populate_table: no targets specified");
1186		return -EINVAL;
1187	}
1188
1189	for (i = 0; i < param->target_count; i++) {
1190
1191		r = next_target(spec, next, end, &spec, &target_params);
1192		if (r) {
1193			DMWARN("unable to find target");
1194			return r;
1195		}
1196
1197		r = dm_table_add_target(table, spec->target_type,
1198					(sector_t) spec->sector_start,
1199					(sector_t) spec->length,
1200					target_params);
1201		if (r) {
1202			DMWARN("error adding target to table");
1203			return r;
1204		}
1205
1206		next = spec->next;
1207	}
1208
1209	return dm_table_complete(table);
1210}
1211
1212static int table_load(struct dm_ioctl *param, size_t param_size)
1213{
1214	int r;
1215	struct hash_cell *hc;
1216	struct dm_table *t;
1217	struct mapped_device *md;
 
1218
1219	md = find_device(param);
1220	if (!md)
1221		return -ENXIO;
1222
1223	r = dm_table_create(&t, get_mode(param), param->target_count, md);
1224	if (r)
1225		goto out;
1226
 
 
1227	r = populate_table(t, param, param_size);
1228	if (r) {
1229		dm_table_destroy(t);
1230		goto out;
 
 
 
 
 
 
 
1231	}
1232
1233	/* Protect md->type and md->queue against concurrent table loads. */
1234	dm_lock_md_type(md);
1235	if (dm_get_md_type(md) == DM_TYPE_NONE)
1236		/* Initial table load: acquire type of table. */
1237		dm_set_md_type(md, dm_table_get_type(t));
1238	else if (dm_get_md_type(md) != dm_table_get_type(t)) {
1239		DMWARN("can't change device type after initial table load.");
1240		dm_table_destroy(t);
1241		dm_unlock_md_type(md);
1242		r = -EINVAL;
1243		goto out;
1244	}
1245
1246	/* setup md->queue to reflect md's type (may block) */
1247	r = dm_setup_md_queue(md);
1248	if (r) {
1249		DMWARN("unable to set up device queue for new table.");
1250		dm_table_destroy(t);
1251		dm_unlock_md_type(md);
1252		goto out;
1253	}
1254	dm_unlock_md_type(md);
1255
1256	/* stage inactive table */
1257	down_write(&_hash_lock);
1258	hc = dm_get_mdptr(md);
1259	if (!hc || hc->md != md) {
1260		DMWARN("device has been removed from the dev hash table.");
1261		dm_table_destroy(t);
1262		up_write(&_hash_lock);
1263		r = -ENXIO;
1264		goto out;
1265	}
1266
1267	if (hc->new_map)
1268		dm_table_destroy(hc->new_map);
1269	hc->new_map = t;
1270	up_write(&_hash_lock);
1271
1272	param->flags |= DM_INACTIVE_PRESENT_FLAG;
1273	__dev_status(md, param);
1274
1275out:
 
 
 
 
 
 
 
 
 
 
 
 
 
1276	dm_put(md);
1277
1278	return r;
1279}
1280
1281static int table_clear(struct dm_ioctl *param, size_t param_size)
1282{
1283	struct hash_cell *hc;
1284	struct mapped_device *md;
 
1285
1286	down_write(&_hash_lock);
1287
1288	hc = __find_device_hash_cell(param);
1289	if (!hc) {
1290		DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1291		up_write(&_hash_lock);
1292		return -ENXIO;
1293	}
1294
1295	if (hc->new_map) {
1296		dm_table_destroy(hc->new_map);
1297		hc->new_map = NULL;
1298	}
1299
1300	param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1301
1302	__dev_status(hc->md, param);
1303	md = hc->md;
1304	up_write(&_hash_lock);
 
 
 
 
1305	dm_put(md);
1306
1307	return 0;
1308}
1309
1310/*
1311 * Retrieves a list of devices used by a particular dm device.
1312 */
1313static void retrieve_deps(struct dm_table *table,
1314			  struct dm_ioctl *param, size_t param_size)
1315{
1316	unsigned int count = 0;
1317	struct list_head *tmp;
1318	size_t len, needed;
1319	struct dm_dev_internal *dd;
1320	struct dm_target_deps *deps;
1321
1322	deps = get_result_buffer(param, param_size, &len);
1323
1324	/*
1325	 * Count the devices.
1326	 */
1327	list_for_each (tmp, dm_table_get_devices(table))
1328		count++;
1329
1330	/*
1331	 * Check we have enough space.
1332	 */
1333	needed = sizeof(*deps) + (sizeof(*deps->dev) * count);
1334	if (len < needed) {
1335		param->flags |= DM_BUFFER_FULL_FLAG;
1336		return;
1337	}
1338
1339	/*
1340	 * Fill in the devices.
1341	 */
1342	deps->count = count;
1343	count = 0;
1344	list_for_each_entry (dd, dm_table_get_devices(table), list)
1345		deps->dev[count++] = huge_encode_dev(dd->dm_dev.bdev->bd_dev);
1346
1347	param->data_size = param->data_start + needed;
1348}
1349
1350static int table_deps(struct dm_ioctl *param, size_t param_size)
1351{
1352	struct mapped_device *md;
1353	struct dm_table *table;
 
1354
1355	md = find_device(param);
1356	if (!md)
1357		return -ENXIO;
1358
1359	__dev_status(md, param);
1360
1361	table = dm_get_live_or_inactive_table(md, param);
1362	if (table) {
1363		retrieve_deps(table, param, param_size);
1364		dm_table_put(table);
1365	}
1366
1367	dm_put(md);
1368
1369	return 0;
1370}
1371
1372/*
1373 * Return the status of a device as a text string for each
1374 * target.
1375 */
1376static int table_status(struct dm_ioctl *param, size_t param_size)
1377{
1378	struct mapped_device *md;
1379	struct dm_table *table;
 
1380
1381	md = find_device(param);
1382	if (!md)
1383		return -ENXIO;
1384
1385	__dev_status(md, param);
1386
1387	table = dm_get_live_or_inactive_table(md, param);
1388	if (table) {
1389		retrieve_status(table, param, param_size);
1390		dm_table_put(table);
1391	}
1392
1393	dm_put(md);
1394
1395	return 0;
1396}
1397
1398/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1399 * Pass a message to the target that's at the supplied device offset.
1400 */
1401static int target_message(struct dm_ioctl *param, size_t param_size)
1402{
1403	int r, argc;
1404	char **argv;
1405	struct mapped_device *md;
1406	struct dm_table *table;
1407	struct dm_target *ti;
1408	struct dm_target_msg *tmsg = (void *) param + param->data_start;
 
 
 
1409
1410	md = find_device(param);
1411	if (!md)
1412		return -ENXIO;
1413
1414	if (tmsg < (struct dm_target_msg *) param->data ||
1415	    invalid_str(tmsg->message, (void *) param + param_size)) {
1416		DMWARN("Invalid target message parameters.");
1417		r = -EINVAL;
1418		goto out;
1419	}
1420
1421	r = dm_split_args(&argc, &argv, tmsg->message);
1422	if (r) {
1423		DMWARN("Failed to split target message parameters");
1424		goto out;
1425	}
1426
1427	if (!argc) {
1428		DMWARN("Empty message received.");
1429		goto out;
1430	}
1431
1432	table = dm_get_live_table(md);
1433	if (!table)
1434		goto out_argv;
1435
 
 
 
 
1436	if (dm_deleting_md(md)) {
1437		r = -ENXIO;
1438		goto out_table;
1439	}
1440
1441	ti = dm_table_find_target(table, tmsg->sector);
1442	if (!dm_target_is_valid(ti)) {
1443		DMWARN("Target message sector outside device.");
1444		r = -EINVAL;
1445	} else if (ti->type->message)
1446		r = ti->type->message(ti, argc, argv);
1447	else {
1448		DMWARN("Target type does not support messages");
1449		r = -EINVAL;
1450	}
1451
1452 out_table:
1453	dm_table_put(table);
1454 out_argv:
1455	kfree(argv);
1456 out:
1457	param->data_size = 0;
 
 
 
 
 
 
 
 
 
 
 
1458	dm_put(md);
1459	return r;
1460}
1461
 
 
 
 
 
 
 
 
1462/*-----------------------------------------------------------------
1463 * Implementation of open/close/ioctl on the special char
1464 * device.
1465 *---------------------------------------------------------------*/
1466static ioctl_fn lookup_ioctl(unsigned int cmd)
1467{
1468	static struct {
1469		int cmd;
 
1470		ioctl_fn fn;
1471	} _ioctls[] = {
1472		{DM_VERSION_CMD, NULL},	/* version is dealt with elsewhere */
1473		{DM_REMOVE_ALL_CMD, remove_all},
1474		{DM_LIST_DEVICES_CMD, list_devices},
1475
1476		{DM_DEV_CREATE_CMD, dev_create},
1477		{DM_DEV_REMOVE_CMD, dev_remove},
1478		{DM_DEV_RENAME_CMD, dev_rename},
1479		{DM_DEV_SUSPEND_CMD, dev_suspend},
1480		{DM_DEV_STATUS_CMD, dev_status},
1481		{DM_DEV_WAIT_CMD, dev_wait},
1482
1483		{DM_TABLE_LOAD_CMD, table_load},
1484		{DM_TABLE_CLEAR_CMD, table_clear},
1485		{DM_TABLE_DEPS_CMD, table_deps},
1486		{DM_TABLE_STATUS_CMD, table_status},
1487
1488		{DM_LIST_VERSIONS_CMD, list_versions},
1489
1490		{DM_TARGET_MSG_CMD, target_message},
1491		{DM_DEV_SET_GEOMETRY_CMD, dev_set_geometry}
1492	};
1493
1494	return (cmd >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[cmd].fn;
 
 
 
 
1495}
1496
1497/*
1498 * As well as checking the version compatibility this always
1499 * copies the kernel interface version out.
1500 */
1501static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
1502{
1503	uint32_t version[3];
1504	int r = 0;
1505
1506	if (copy_from_user(version, user->version, sizeof(version)))
1507		return -EFAULT;
1508
1509	if ((DM_VERSION_MAJOR != version[0]) ||
1510	    (DM_VERSION_MINOR < version[1])) {
1511		DMWARN("ioctl interface mismatch: "
1512		       "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
1513		       DM_VERSION_MAJOR, DM_VERSION_MINOR,
1514		       DM_VERSION_PATCHLEVEL,
1515		       version[0], version[1], version[2], cmd);
1516		r = -EINVAL;
1517	}
1518
1519	/*
1520	 * Fill in the kernel version.
1521	 */
1522	version[0] = DM_VERSION_MAJOR;
1523	version[1] = DM_VERSION_MINOR;
1524	version[2] = DM_VERSION_PATCHLEVEL;
1525	if (copy_to_user(user->version, version, sizeof(version)))
1526		return -EFAULT;
1527
1528	return r;
1529}
1530
1531static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param)
 
 
 
 
1532{
1533	struct dm_ioctl tmp, *dmi;
 
 
 
 
 
 
 
 
 
 
 
 
 
1534	int secure_data;
 
1535
1536	if (copy_from_user(&tmp, user, sizeof(tmp) - sizeof(tmp.data)))
1537		return -EFAULT;
1538
1539	if (tmp.data_size < (sizeof(tmp) - sizeof(tmp.data)))
1540		return -EINVAL;
1541
1542	secure_data = tmp.flags & DM_SECURE_DATA_FLAG;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1543
1544	dmi = vmalloc(tmp.data_size);
1545	if (!dmi) {
1546		if (secure_data && clear_user(user, tmp.data_size))
 
 
 
 
 
 
 
 
 
1547			return -EFAULT;
1548		return -ENOMEM;
1549	}
1550
1551	if (copy_from_user(dmi, user, tmp.data_size))
 
 
 
 
 
 
 
 
1552		goto bad;
 
1553
1554	/* Wipe the user buffer so we do not return it to userspace */
1555	if (secure_data && clear_user(user, tmp.data_size))
1556		goto bad;
1557
1558	*param = dmi;
1559	return 0;
1560
1561bad:
1562	if (secure_data)
1563		memset(dmi, 0, tmp.data_size);
1564	vfree(dmi);
1565	return -EFAULT;
1566}
1567
1568static int validate_params(uint cmd, struct dm_ioctl *param)
1569{
1570	/* Always clear this flag */
1571	param->flags &= ~DM_BUFFER_FULL_FLAG;
1572	param->flags &= ~DM_UEVENT_GENERATED_FLAG;
1573	param->flags &= ~DM_SECURE_DATA_FLAG;
 
1574
1575	/* Ignores parameters */
1576	if (cmd == DM_REMOVE_ALL_CMD ||
1577	    cmd == DM_LIST_DEVICES_CMD ||
1578	    cmd == DM_LIST_VERSIONS_CMD)
1579		return 0;
1580
1581	if ((cmd == DM_DEV_CREATE_CMD)) {
1582		if (!*param->name) {
1583			DMWARN("name not supplied when creating device");
1584			return -EINVAL;
1585		}
1586	} else if ((*param->uuid && *param->name)) {
1587		DMWARN("only supply one of name or uuid, cmd(%u)", cmd);
1588		return -EINVAL;
1589	}
1590
1591	/* Ensure strings are terminated */
1592	param->name[DM_NAME_LEN - 1] = '\0';
1593	param->uuid[DM_UUID_LEN - 1] = '\0';
1594
1595	return 0;
1596}
1597
1598static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
1599{
1600	int r = 0;
1601	int wipe_buffer;
 
1602	unsigned int cmd;
1603	struct dm_ioctl *uninitialized_var(param);
1604	ioctl_fn fn = NULL;
1605	size_t input_param_size;
 
1606
1607	/* only root can play with this */
1608	if (!capable(CAP_SYS_ADMIN))
1609		return -EACCES;
1610
1611	if (_IOC_TYPE(command) != DM_IOCTL)
1612		return -ENOTTY;
1613
1614	cmd = _IOC_NR(command);
1615
1616	/*
1617	 * Check the interface version passed in.  This also
1618	 * writes out the kernel's interface version.
1619	 */
1620	r = check_version(cmd, user);
1621	if (r)
1622		return r;
1623
1624	/*
1625	 * Nothing more to do for the version command.
1626	 */
1627	if (cmd == DM_VERSION_CMD)
1628		return 0;
1629
1630	fn = lookup_ioctl(cmd);
1631	if (!fn) {
1632		DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);
1633		return -ENOTTY;
1634	}
1635
1636	/*
1637	 * Trying to avoid low memory issues when a device is
1638	 * suspended.
1639	 */
1640	current->flags |= PF_MEMALLOC;
1641
1642	/*
1643	 * Copy the parameters into kernel space.
1644	 */
1645	r = copy_params(user, &param);
1646
1647	current->flags &= ~PF_MEMALLOC;
1648
1649	if (r)
1650		return r;
1651
1652	input_param_size = param->data_size;
1653	wipe_buffer = param->flags & DM_SECURE_DATA_FLAG;
1654
1655	r = validate_params(cmd, param);
1656	if (r)
1657		goto out;
1658
1659	param->data_size = sizeof(*param);
1660	r = fn(param, input_param_size);
1661
 
 
 
 
1662	/*
1663	 * Copy the results back to userland.
1664	 */
1665	if (!r && copy_to_user(user, param, param->data_size))
1666		r = -EFAULT;
1667
1668out:
1669	if (wipe_buffer)
1670		memset(param, 0, input_param_size);
1671
1672	vfree(param);
1673	return r;
1674}
1675
1676static long dm_ctl_ioctl(struct file *file, uint command, ulong u)
1677{
1678	return (long)ctl_ioctl(command, (struct dm_ioctl __user *)u);
1679}
1680
1681#ifdef CONFIG_COMPAT
1682static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u)
1683{
1684	return (long)dm_ctl_ioctl(file, command, (ulong) compat_ptr(u));
1685}
1686#else
1687#define dm_compat_ctl_ioctl NULL
1688#endif
1689
1690static const struct file_operations _ctl_fops = {
1691	.open = nonseekable_open,
1692	.unlocked_ioctl	 = dm_ctl_ioctl,
1693	.compat_ioctl = dm_compat_ctl_ioctl,
1694	.owner	 = THIS_MODULE,
1695	.llseek  = noop_llseek,
1696};
1697
1698static struct miscdevice _dm_misc = {
1699	.minor		= MAPPER_CTRL_MINOR,
1700	.name  		= DM_NAME,
1701	.nodename	= DM_DIR "/" DM_CONTROL_NODE,
1702	.fops  		= &_ctl_fops
1703};
1704
1705MODULE_ALIAS_MISCDEV(MAPPER_CTRL_MINOR);
1706MODULE_ALIAS("devname:" DM_DIR "/" DM_CONTROL_NODE);
1707
1708/*
1709 * Create misc character device and link to DM_DIR/control.
1710 */
1711int __init dm_interface_init(void)
1712{
1713	int r;
1714
1715	r = dm_hash_init();
1716	if (r)
1717		return r;
1718
1719	r = misc_register(&_dm_misc);
1720	if (r) {
1721		DMERR("misc_register failed for control device");
1722		dm_hash_exit();
1723		return r;
1724	}
1725
1726	DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
1727	       DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
1728	       DM_DRIVER_EMAIL);
1729	return 0;
1730}
1731
1732void dm_interface_exit(void)
1733{
1734	if (misc_deregister(&_dm_misc) < 0)
1735		DMERR("misc_deregister failed for control device");
1736
1737	dm_hash_exit();
1738}
1739
1740/**
1741 * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers
1742 * @md: Pointer to mapped_device
1743 * @name: Buffer (size DM_NAME_LEN) for name
1744 * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined
1745 */
1746int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
1747{
1748	int r = 0;
1749	struct hash_cell *hc;
1750
1751	if (!md)
1752		return -ENXIO;
1753
1754	mutex_lock(&dm_hash_cells_mutex);
1755	hc = dm_get_mdptr(md);
1756	if (!hc || hc->md != md) {
1757		r = -ENXIO;
1758		goto out;
1759	}
1760
1761	if (name)
1762		strcpy(name, hc->name);
1763	if (uuid)
1764		strcpy(uuid, hc->uuid ? : "");
1765
1766out:
1767	mutex_unlock(&dm_hash_cells_mutex);
1768
1769	return r;
1770}