drivers/md/dm-ioctl.c

   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  *---------------------------------------------------------------*/
  29 struct 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
  39 struct 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)
  49 static struct list_head _name_buckets[NUM_BUCKETS];
  50 static struct list_head _uuid_buckets[NUM_BUCKETS];
  51
  52 static void dm_hash_remove_all(int keep_open_devices);
  53
  54 /*
  55  * Guards access to both hash tables.
  56  */
  57 static DECLARE_RWSEM(_hash_lock);
  58
  59 /*
  60  * Protects use of mdptr to obtain hash cell name and uuid from mapped device.
  61  */
  62 static DEFINE_MUTEX(dm_hash_cells_mutex);
  63
  64 static 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
  72 static int dm_hash_init(void)
  73 {
  74         init_buckets(_name_buckets);
  75         init_buckets(_uuid_buckets);
  76         return 0;
  77 }
  78
  79 static 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  *---------------------------------------------------------------*/
  89 static 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  *---------------------------------------------------------------*/
 103 static 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
 117 static 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
 131 /*-----------------------------------------------------------------
 132  * Inserting, removing and renaming a device.
 133  *---------------------------------------------------------------*/
 134 static struct hash_cell *alloc_cell(const char *name, const char *uuid,
 135                                     struct mapped_device *md)
 136 {
 137         struct hash_cell *hc;
 138
 139         hc = kmalloc(sizeof(*hc), GFP_KERNEL);
 140         if (!hc)
 141                 return NULL;
 142
 143         hc->name = kstrdup(name, GFP_KERNEL);
 144         if (!hc->name) {
 145                 kfree(hc);
 146                 return NULL;
 147         }
 148
 149         if (!uuid)
 150                 hc->uuid = NULL;
 151
 152         else {
 153                 hc->uuid = kstrdup(uuid, GFP_KERNEL);
 154                 if (!hc->uuid) {
 155                         kfree(hc->name);
 156                         kfree(hc);
 157                         return NULL;
 158                 }
 159         }
 160
 161         INIT_LIST_HEAD(&hc->name_list);
 162         INIT_LIST_HEAD(&hc->uuid_list);
 163         hc->md = md;
 164         hc->new_map = NULL;
 165         return hc;
 166 }
 167
 168 static void free_cell(struct hash_cell *hc)
 169 {
 170         if (hc) {
 171                 kfree(hc->name);
 172                 kfree(hc->uuid);
 173                 kfree(hc);
 174         }
 175 }
 176
 177 /*
 178  * The kdev_t and uuid of a device can never change once it is
 179  * initially inserted.
 180  */
 181 static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md)
 182 {
 183         struct hash_cell *cell, *hc;
 184
 185         /*
 186          * Allocate the new cells.
 187          */
 188         cell = alloc_cell(name, uuid, md);
 189         if (!cell)
 190                 return -ENOMEM;
 191
 192         /*
 193          * Insert the cell into both hash tables.
 194          */
 195         down_write(&_hash_lock);
 196         hc = __get_name_cell(name);
 197         if (hc) {
 198                 dm_put(hc->md);
 199                 goto bad;
 200         }
 201
 202         list_add(&cell->name_list, _name_buckets + hash_str(name));
 203
 204         if (uuid) {
 205                 hc = __get_uuid_cell(uuid);
 206                 if (hc) {
 207                         list_del(&cell->name_list);
 208                         dm_put(hc->md);
 209                         goto bad;
 210                 }
 211                 list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid));
 212         }
 213         dm_get(md);
 214         mutex_lock(&dm_hash_cells_mutex);
 215         dm_set_mdptr(md, cell);
 216         mutex_unlock(&dm_hash_cells_mutex);
 217         up_write(&_hash_lock);
 218
 219         return 0;
 220
 221  bad:
 222         up_write(&_hash_lock);
 223         free_cell(cell);
 224         return -EBUSY;
 225 }
 226
 227 static void __hash_remove(struct hash_cell *hc)
 228 {
 229         struct dm_table *table;
 230
 231         /* remove from the dev hash */
 232         list_del(&hc->uuid_list);
 233         list_del(&hc->name_list);
 234         mutex_lock(&dm_hash_cells_mutex);
 235         dm_set_mdptr(hc->md, NULL);
 236         mutex_unlock(&dm_hash_cells_mutex);
 237
 238         table = dm_get_live_table(hc->md);
 239         if (table) {
 240                 dm_table_event(table);
 241                 dm_table_put(table);
 242         }
 243
 244         if (hc->new_map)
 245                 dm_table_destroy(hc->new_map);
 246         dm_put(hc->md);
 247         free_cell(hc);
 248 }
 249
 250 static void dm_hash_remove_all(int keep_open_devices)
 251 {
 252         int i, dev_skipped, dev_removed;
 253         struct hash_cell *hc;
 254         struct list_head *tmp, *n;
 255
 256         down_write(&_hash_lock);
 257
 258 retry:
 259         dev_skipped = dev_removed = 0;
 260         for (i = 0; i < NUM_BUCKETS; i++) {
 261                 list_for_each_safe (tmp, n, _name_buckets + i) {
 262                         hc = list_entry(tmp, struct hash_cell, name_list);
 263
 264                         if (keep_open_devices &&
 265                             dm_lock_for_deletion(hc->md)) {
 266                                 dev_skipped++;
 267                                 continue;
 268                         }
 269                         __hash_remove(hc);
 270                         dev_removed = 1;
 271                 }
 272         }
 273
 274         /*
 275          * Some mapped devices may be using other mapped devices, so if any
 276          * still exist, repeat until we make no further progress.
 277          */
 278         if (dev_skipped) {
 279                 if (dev_removed)
 280                         goto retry;
 281
 282                 DMWARN("remove_all left %d open device(s)", dev_skipped);
 283         }
 284
 285         up_write(&_hash_lock);
 286 }
 287
 288 static int dm_hash_rename(uint32_t cookie, uint32_t *flags, const char *old,
 289                           const char *new)
 290 {
 291         char *new_name, *old_name;
 292         struct hash_cell *hc;
 293         struct dm_table *table;
 294
 295         /*
 296          * duplicate new.
 297          */
 298         new_name = kstrdup(new, GFP_KERNEL);
 299         if (!new_name)
 300                 return -ENOMEM;
 301
 302         down_write(&_hash_lock);
 303
 304         /*
 305          * Is new free ?
 306          */
 307         hc = __get_name_cell(new);
 308         if (hc) {
 309                 DMWARN("asked to rename to an already existing name %s -> %s",
 310                        old, new);
 311                 dm_put(hc->md);
 312                 up_write(&_hash_lock);
 313                 kfree(new_name);
 314                 return -EBUSY;
 315         }
 316
 317         /*
 318          * Is there such a device as 'old' ?
 319          */
 320         hc = __get_name_cell(old);
 321         if (!hc) {
 322                 DMWARN("asked to rename a non existent device %s -> %s",
 323                        old, new);
 324                 up_write(&_hash_lock);
 325                 kfree(new_name);
 326                 return -ENXIO;
 327         }
 328
 329         /*
 330          * rename and move the name cell.
 331          */
 332         list_del(&hc->name_list);
 333         old_name = hc->name;
 334         mutex_lock(&dm_hash_cells_mutex);
 335         hc->name = new_name;
 336         mutex_unlock(&dm_hash_cells_mutex);
 337         list_add(&hc->name_list, _name_buckets + hash_str(new_name));
 338
 339         /*
 340          * Wake up any dm event waiters.
 341          */
 342         table = dm_get_live_table(hc->md);
 343         if (table) {
 344                 dm_table_event(table);
 345                 dm_table_put(table);
 346         }
 347
 348         if (!dm_kobject_uevent(hc->md, KOBJ_CHANGE, cookie))
 349                 *flags |= DM_UEVENT_GENERATED_FLAG;
 350
 351         dm_put(hc->md);
 352         up_write(&_hash_lock);
 353         kfree(old_name);
 354         return 0;
 355 }
 356
 357 /*-----------------------------------------------------------------
 358  * Implementation of the ioctl commands
 359  *---------------------------------------------------------------*/
 360 /*
 361  * All the ioctl commands get dispatched to functions with this
 362  * prototype.
 363  */
 364 typedef int (*ioctl_fn)(struct dm_ioctl *param, size_t param_size);
 365
 366 static int remove_all(struct dm_ioctl *param, size_t param_size)
 367 {
 368         dm_hash_remove_all(1);
 369         param->data_size = 0;
 370         return 0;
 371 }
 372
 373 /*
 374  * Round up the ptr to an 8-byte boundary.
 375  */
 376 #define ALIGN_MASK 7
 377 static inline void *align_ptr(void *ptr)
 378 {
 379         return (void *) (((size_t) (ptr + ALIGN_MASK)) & ~ALIGN_MASK);
 380 }
 381
 382 /*
 383  * Retrieves the data payload buffer from an already allocated
 384  * struct dm_ioctl.
 385  */
 386 static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
 387                                size_t *len)
 388 {
 389         param->data_start = align_ptr(param + 1) - (void *) param;
 390
 391         if (param->data_start < param_size)
 392                 *len = param_size - param->data_start;
 393         else
 394                 *len = 0;
 395
 396         return ((void *) param) + param->data_start;
 397 }
 398
 399 static int list_devices(struct dm_ioctl *param, size_t param_size)
 400 {
 401         unsigned int i;
 402         struct hash_cell *hc;
 403         size_t len, needed = 0;
 404         struct gendisk *disk;
 405         struct dm_name_list *nl, *old_nl = NULL;
 406
 407         down_write(&_hash_lock);
 408
 409         /*
 410          * Loop through all the devices working out how much
 411          * space we need.
 412          */
 413         for (i = 0; i < NUM_BUCKETS; i++) {
 414                 list_for_each_entry (hc, _name_buckets + i, name_list) {
 415                         needed += sizeof(struct dm_name_list);
 416                         needed += strlen(hc->name) + 1;
 417                         needed += ALIGN_MASK;
 418                 }
 419         }
 420
 421         /*
 422          * Grab our output buffer.
 423          */
 424         nl = get_result_buffer(param, param_size, &len);
 425         if (len < needed) {
 426                 param->flags |= DM_BUFFER_FULL_FLAG;
 427                 goto out;
 428         }
 429         param->data_size = param->data_start + needed;
 430
 431         nl->dev = 0;    /* Flags no data */
 432
 433         /*
 434          * Now loop through filling out the names.
 435          */
 436         for (i = 0; i < NUM_BUCKETS; i++) {
 437                 list_for_each_entry (hc, _name_buckets + i, name_list) {
 438                         if (old_nl)
 439                                 old_nl->next = (uint32_t) ((void *) nl -
 440                                                            (void *) old_nl);
 441                         disk = dm_disk(hc->md);
 442                         nl->dev = huge_encode_dev(disk_devt(disk));
 443                         nl->next = 0;
 444                         strcpy(nl->name, hc->name);
 445
 446                         old_nl = nl;
 447                         nl = align_ptr(((void *) ++nl) + strlen(hc->name) + 1);
 448                 }
 449         }
 450
 451  out:
 452         up_write(&_hash_lock);
 453         return 0;
 454 }
 455
 456 static void list_version_get_needed(struct target_type *tt, void *needed_param)
 457 {
 458     size_t *needed = needed_param;
 459
 460     *needed += sizeof(struct dm_target_versions);
 461     *needed += strlen(tt->name);
 462     *needed += ALIGN_MASK;
 463 }
 464
 465 static void list_version_get_info(struct target_type *tt, void *param)
 466 {
 467     struct vers_iter *info = param;
 468
 469     /* Check space - it might have changed since the first iteration */
 470     if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 >
 471         info->end) {
 472
 473         info->flags = DM_BUFFER_FULL_FLAG;
 474         return;
 475     }
 476
 477     if (info->old_vers)
 478         info->old_vers->next = (uint32_t) ((void *)info->vers -
 479                                            (void *)info->old_vers);
 480     info->vers->version[0] = tt->version[0];
 481     info->vers->version[1] = tt->version[1];
 482     info->vers->version[2] = tt->version[2];
 483     info->vers->next = 0;
 484     strcpy(info->vers->name, tt->name);
 485
 486     info->old_vers = info->vers;
 487     info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1);
 488 }
 489
 490 static int list_versions(struct dm_ioctl *param, size_t param_size)
 491 {
 492         size_t len, needed = 0;
 493         struct dm_target_versions *vers;
 494         struct vers_iter iter_info;
 495
 496         /*
 497          * Loop through all the devices working out how much
 498          * space we need.
 499          */
 500         dm_target_iterate(list_version_get_needed, &needed);
 501
 502         /*
 503          * Grab our output buffer.
 504          */
 505         vers = get_result_buffer(param, param_size, &len);
 506         if (len < needed) {
 507                 param->flags |= DM_BUFFER_FULL_FLAG;
 508                 goto out;
 509         }
 510         param->data_size = param->data_start + needed;
 511
 512         iter_info.param_size = param_size;
 513         iter_info.old_vers = NULL;
 514         iter_info.vers = vers;
 515         iter_info.flags = 0;
 516         iter_info.end = (char *)vers+len;
 517
 518         /*
 519          * Now loop through filling out the names & versions.
 520          */
 521         dm_target_iterate(list_version_get_info, &iter_info);
 522         param->flags |= iter_info.flags;
 523
 524  out:
 525         return 0;
 526 }
 527
 528 static int check_name(const char *name)
 529 {
 530         if (strchr(name, '/')) {
 531                 DMWARN("invalid device name");
 532                 return -EINVAL;
 533         }
 534
 535         return 0;
 536 }
 537
 538 /*
 539  * On successful return, the caller must not attempt to acquire
 540  * _hash_lock without first calling dm_table_put, because dm_table_destroy
 541  * waits for this dm_table_put and could be called under this lock.
 542  */
 543 static struct dm_table *dm_get_inactive_table(struct mapped_device *md)
 544 {
 545         struct hash_cell *hc;
 546         struct dm_table *table = NULL;
 547
 548         down_read(&_hash_lock);
 549         hc = dm_get_mdptr(md);
 550         if (!hc || hc->md != md) {
 551                 DMWARN("device has been removed from the dev hash table.");
 552                 goto out;
 553         }
 554
 555         table = hc->new_map;
 556         if (table)
 557                 dm_table_get(table);
 558
 559 out:
 560         up_read(&_hash_lock);
 561
 562         return table;
 563 }
 564
 565 static struct dm_table *dm_get_live_or_inactive_table(struct mapped_device *md,
 566                                                       struct dm_ioctl *param)
 567 {
 568         return (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) ?
 569                 dm_get_inactive_table(md) : dm_get_live_table(md);
 570 }
 571
 572 /*
 573  * Fills in a dm_ioctl structure, ready for sending back to
 574  * userland.
 575  */
 576 static int __dev_status(struct mapped_device *md, struct dm_ioctl *param)
 577 {
 578         struct gendisk *disk = dm_disk(md);
 579         struct dm_table *table;
 580
 581         param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
 582                           DM_ACTIVE_PRESENT_FLAG);
 583
 584         if (dm_suspended_md(md))
 585                 param->flags |= DM_SUSPEND_FLAG;
 586
 587         param->dev = huge_encode_dev(disk_devt(disk));
 588
 589         /*
 590          * Yes, this will be out of date by the time it gets back
 591          * to userland, but it is still very useful for
 592          * debugging.
 593          */
 594         param->open_count = dm_open_count(md);
 595
 596         param->event_nr = dm_get_event_nr(md);
 597         param->target_count = 0;
 598
 599         table = dm_get_live_table(md);
 600         if (table) {
 601                 if (!(param->flags & DM_QUERY_INACTIVE_TABLE_FLAG)) {
 602                         if (get_disk_ro(disk))
 603                                 param->flags |= DM_READONLY_FLAG;
 604                         param->target_count = dm_table_get_num_targets(table);
 605                 }
 606                 dm_table_put(table);
 607
 608                 param->flags |= DM_ACTIVE_PRESENT_FLAG;
 609         }
 610
 611         if (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) {
 612                 table = dm_get_inactive_table(md);
 613                 if (table) {
 614                         if (!(dm_table_get_mode(table) & FMODE_WRITE))
 615                                 param->flags |= DM_READONLY_FLAG;
 616                         param->target_count = dm_table_get_num_targets(table);
 617                         dm_table_put(table);
 618                 }
 619         }
 620
 621         return 0;
 622 }
 623
 624 static int dev_create(struct dm_ioctl *param, size_t param_size)
 625 {
 626         int r, m = DM_ANY_MINOR;
 627         struct mapped_device *md;
 628
 629         r = check_name(param->name);
 630         if (r)
 631                 return r;
 632
 633         if (param->flags & DM_PERSISTENT_DEV_FLAG)
 634                 m = MINOR(huge_decode_dev(param->dev));
 635
 636         r = dm_create(m, &md);
 637         if (r)
 638                 return r;
 639
 640         r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
 641         if (r) {
 642                 dm_put(md);
 643                 return r;
 644         }
 645
 646         param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
 647
 648         r = __dev_status(md, param);
 649         dm_put(md);
 650
 651         return r;
 652 }
 653
 654 /*
 655  * Always use UUID for lookups if it's present, otherwise use name or dev.
 656  */
 657 static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
 658 {
 659         struct mapped_device *md;
 660         void *mdptr = NULL;
 661
 662         if (*param->uuid)
 663                 return __get_uuid_cell(param->uuid);
 664
 665         if (*param->name)
 666                 return __get_name_cell(param->name);
 667
 668         md = dm_get_md(huge_decode_dev(param->dev));
 669         if (!md)
 670                 goto out;
 671
 672         mdptr = dm_get_mdptr(md);
 673         if (!mdptr)
 674                 dm_put(md);
 675
 676 out:
 677         return mdptr;
 678 }
 679
 680 static struct mapped_device *find_device(struct dm_ioctl *param)
 681 {
 682         struct hash_cell *hc;
 683         struct mapped_device *md = NULL;
 684
 685         down_read(&_hash_lock);
 686         hc = __find_device_hash_cell(param);
 687         if (hc) {
 688                 md = hc->md;
 689
 690                 /*
 691                  * Sneakily write in both the name and the uuid
 692                  * while we have the cell.
 693                  */
 694                 strlcpy(param->name, hc->name, sizeof(param->name));
 695                 if (hc->uuid)
 696                         strlcpy(param->uuid, hc->uuid, sizeof(param->uuid));
 697                 else
 698                         param->uuid[0] = '\0';
 699
 700                 if (hc->new_map)
 701                         param->flags |= DM_INACTIVE_PRESENT_FLAG;
 702                 else
 703                         param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
 704         }
 705         up_read(&_hash_lock);
 706
 707         return md;
 708 }
 709
 710 static int dev_remove(struct dm_ioctl *param, size_t param_size)
 711 {
 712         struct hash_cell *hc;
 713         struct mapped_device *md;
 714         int r;
 715
 716         down_write(&_hash_lock);
 717         hc = __find_device_hash_cell(param);
 718
 719         if (!hc) {
 720                 DMWARN("device doesn't appear to be in the dev hash table.");
 721                 up_write(&_hash_lock);
 722                 return -ENXIO;
 723         }
 724
 725         md = hc->md;
 726
 727         /*
 728          * Ensure the device is not open and nothing further can open it.
 729          */
 730         r = dm_lock_for_deletion(md);
 731         if (r) {
 732                 DMWARN("unable to remove open device %s", hc->name);
 733                 up_write(&_hash_lock);
 734                 dm_put(md);
 735                 return r;
 736         }
 737
 738         __hash_remove(hc);
 739         up_write(&_hash_lock);
 740
 741         if (!dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr))
 742                 param->flags |= DM_UEVENT_GENERATED_FLAG;
 743
 744         dm_put(md);
 745         return 0;
 746 }
 747
 748 /*
 749  * Check a string doesn't overrun the chunk of
 750  * memory we copied from userland.
 751  */
 752 static int invalid_str(char *str, void *end)
 753 {
 754         while ((void *) str < end)
 755                 if (!*str++)
 756                         return 0;
 757
 758         return -EINVAL;
 759 }
 760
 761 static int dev_rename(struct dm_ioctl *param, size_t param_size)
 762 {
 763         int r;
 764         char *new_name = (char *) param + param->data_start;
 765
 766         if (new_name < param->data ||
 767             invalid_str(new_name, (void *) param + param_size) ||
 768             strlen(new_name) > DM_NAME_LEN - 1) {
 769                 DMWARN("Invalid new logical volume name supplied.");
 770                 return -EINVAL;
 771         }
 772
 773         r = check_name(new_name);
 774         if (r)
 775                 return r;
 776
 777         param->data_size = 0;
 778
 779         return dm_hash_rename(param->event_nr, &param->flags, param->name,
 780                               new_name);
 781 }
 782
 783 static int dev_set_geometry(struct dm_ioctl *param, size_t param_size)
 784 {
 785         int r = -EINVAL, x;
 786         struct mapped_device *md;
 787         struct hd_geometry geometry;
 788         unsigned long indata[4];
 789         char *geostr = (char *) param + param->data_start;
 790
 791         md = find_device(param);
 792         if (!md)
 793                 return -ENXIO;
 794
 795         if (geostr < param->data ||
 796             invalid_str(geostr, (void *) param + param_size)) {
 797                 DMWARN("Invalid geometry supplied.");
 798                 goto out;
 799         }
 800
 801         x = sscanf(geostr, "%lu %lu %lu %lu", indata,
 802                    indata + 1, indata + 2, indata + 3);
 803
 804         if (x != 4) {
 805                 DMWARN("Unable to interpret geometry settings.");
 806                 goto out;
 807         }
 808
 809         if (indata[0] > 65535 || indata[1] > 255 ||
 810             indata[2] > 255 || indata[3] > ULONG_MAX) {
 811                 DMWARN("Geometry exceeds range limits.");
 812                 goto out;
 813         }
 814
 815         geometry.cylinders = indata[0];
 816         geometry.heads = indata[1];
 817         geometry.sectors = indata[2];
 818         geometry.start = indata[3];
 819
 820         r = dm_set_geometry(md, &geometry);
 821         if (!r)
 822                 r = __dev_status(md, param);
 823
 824         param->data_size = 0;
 825
 826 out:
 827         dm_put(md);
 828         return r;
 829 }
 830
 831 static int do_suspend(struct dm_ioctl *param)
 832 {
 833         int r = 0;
 834         unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
 835         struct mapped_device *md;
 836
 837         md = find_device(param);
 838         if (!md)
 839                 return -ENXIO;
 840
 841         if (param->flags & DM_SKIP_LOCKFS_FLAG)
 842                 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
 843         if (param->flags & DM_NOFLUSH_FLAG)
 844                 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
 845
 846         if (!dm_suspended_md(md))
 847                 r = dm_suspend(md, suspend_flags);
 848
 849         if (!r)
 850                 r = __dev_status(md, param);
 851
 852         dm_put(md);
 853         return r;
 854 }
 855
 856 static int do_resume(struct dm_ioctl *param)
 857 {
 858         int r = 0;
 859         unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
 860         struct hash_cell *hc;
 861         struct mapped_device *md;
 862         struct dm_table *new_map, *old_map = NULL;
 863
 864         down_write(&_hash_lock);
 865
 866         hc = __find_device_hash_cell(param);
 867         if (!hc) {
 868                 DMWARN("device doesn't appear to be in the dev hash table.");
 869                 up_write(&_hash_lock);
 870                 return -ENXIO;
 871         }
 872
 873         md = hc->md;
 874
 875         new_map = hc->new_map;
 876         hc->new_map = NULL;
 877         param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
 878
 879         up_write(&_hash_lock);
 880
 881         /* Do we need to load a new map ? */
 882         if (new_map) {
 883                 /* Suspend if it isn't already suspended */
 884                 if (param->flags & DM_SKIP_LOCKFS_FLAG)
 885                         suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
 886                 if (param->flags & DM_NOFLUSH_FLAG)
 887                         suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
 888                 if (!dm_suspended_md(md))
 889                         dm_suspend(md, suspend_flags);
 890
 891                 old_map = dm_swap_table(md, new_map);
 892                 if (IS_ERR(old_map)) {
 893                         dm_table_destroy(new_map);
 894                         dm_put(md);
 895                         return PTR_ERR(old_map);
 896                 }
 897
 898                 if (dm_table_get_mode(new_map) & FMODE_WRITE)
 899                         set_disk_ro(dm_disk(md), 0);
 900                 else
 901                         set_disk_ro(dm_disk(md), 1);
 902         }
 903
 904         if (dm_suspended_md(md)) {
 905                 r = dm_resume(md);
 906                 if (!r && !dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr))
 907                         param->flags |= DM_UEVENT_GENERATED_FLAG;
 908         }
 909
 910         if (old_map)
 911                 dm_table_destroy(old_map);
 912
 913         if (!r)
 914                 r = __dev_status(md, param);
 915
 916         dm_put(md);
 917         return r;
 918 }
 919
 920 /*
 921  * Set or unset the suspension state of a device.
 922  * If the device already is in the requested state we just return its status.
 923  */
 924 static int dev_suspend(struct dm_ioctl *param, size_t param_size)
 925 {
 926         if (param->flags & DM_SUSPEND_FLAG)
 927                 return do_suspend(param);
 928
 929         return do_resume(param);
 930 }
 931
 932 /*
 933  * Copies device info back to user space, used by
 934  * the create and info ioctls.
 935  */
 936 static int dev_status(struct dm_ioctl *param, size_t param_size)
 937 {
 938         int r;
 939         struct mapped_device *md;
 940
 941         md = find_device(param);
 942         if (!md)
 943                 return -ENXIO;
 944
 945         r = __dev_status(md, param);
 946         dm_put(md);
 947         return r;
 948 }
 949
 950 /*
 951  * Build up the status struct for each target
 952  */
 953 static void retrieve_status(struct dm_table *table,
 954                             struct dm_ioctl *param, size_t param_size)
 955 {
 956         unsigned int i, num_targets;
 957         struct dm_target_spec *spec;
 958         char *outbuf, *outptr;
 959         status_type_t type;
 960         size_t remaining, len, used = 0;
 961
 962         outptr = outbuf = get_result_buffer(param, param_size, &len);
 963
 964         if (param->flags & DM_STATUS_TABLE_FLAG)
 965                 type = STATUSTYPE_TABLE;
 966         else
 967                 type = STATUSTYPE_INFO;
 968
 969         /* Get all the target info */
 970         num_targets = dm_table_get_num_targets(table);
 971         for (i = 0; i < num_targets; i++) {
 972                 struct dm_target *ti = dm_table_get_target(table, i);
 973
 974                 remaining = len - (outptr - outbuf);
 975                 if (remaining <= sizeof(struct dm_target_spec)) {
 976                         param->flags |= DM_BUFFER_FULL_FLAG;
 977                         break;
 978                 }
 979
 980                 spec = (struct dm_target_spec *) outptr;
 981
 982                 spec->status = 0;
 983                 spec->sector_start = ti->begin;
 984                 spec->length = ti->len;
 985                 strncpy(spec->target_type, ti->type->name,
 986                         sizeof(spec->target_type));
 987
 988                 outptr += sizeof(struct dm_target_spec);
 989                 remaining = len - (outptr - outbuf);
 990                 if (remaining <= 0) {
 991                         param->flags |= DM_BUFFER_FULL_FLAG;
 992                         break;
 993                 }
 994
 995                 /* Get the status/table string from the target driver */
 996                 if (ti->type->status) {
 997                         if (ti->type->status(ti, type, outptr, remaining)) {
 998                                 param->flags |= DM_BUFFER_FULL_FLAG;
 999                                 break;
1000                         }
1001                 } else
1002                         outptr[0] = '\0';
1003
1004                 outptr += strlen(outptr) + 1;
1005                 used = param->data_start + (outptr - outbuf);
1006
1007                 outptr = align_ptr(outptr);
1008                 spec->next = outptr - outbuf;
1009         }
1010
1011         if (used)
1012                 param->data_size = used;
1013
1014         param->target_count = num_targets;
1015 }
1016
1017 /*
1018  * Wait for a device to report an event
1019  */
1020 static int dev_wait(struct dm_ioctl *param, size_t param_size)
1021 {
1022         int r;
1023         struct mapped_device *md;
1024         struct dm_table *table;
1025
1026         md = find_device(param);
1027         if (!md)
1028                 return -ENXIO;
1029
1030         /*
1031          * Wait for a notification event
1032          */
1033         if (dm_wait_event(md, param->event_nr)) {
1034                 r = -ERESTARTSYS;
1035                 goto out;
1036         }
1037
1038         /*
1039          * The userland program is going to want to know what
1040          * changed to trigger the event, so we may as well tell
1041          * him and save an ioctl.
1042          */
1043         r = __dev_status(md, param);
1044         if (r)
1045                 goto out;
1046
1047         table = dm_get_live_or_inactive_table(md, param);
1048         if (table) {
1049                 retrieve_status(table, param, param_size);
1050                 dm_table_put(table);
1051         }
1052
1053  out:
1054         dm_put(md);
1055         return r;
1056 }
1057
1058 static inline fmode_t get_mode(struct dm_ioctl *param)
1059 {
1060         fmode_t mode = FMODE_READ | FMODE_WRITE;
1061
1062         if (param->flags & DM_READONLY_FLAG)
1063                 mode = FMODE_READ;
1064
1065         return mode;
1066 }
1067
1068 static int next_target(struct dm_target_spec *last, uint32_t next, void *end,
1069                        struct dm_target_spec **spec, char **target_params)
1070 {
1071         *spec = (struct dm_target_spec *) ((unsigned char *) last + next);
1072         *target_params = (char *) (*spec + 1);
1073
1074         if (*spec < (last + 1))
1075                 return -EINVAL;
1076
1077         return invalid_str(*target_params, end);
1078 }
1079
1080 static int populate_table(struct dm_table *table,
1081                           struct dm_ioctl *param, size_t param_size)
1082 {
1083         int r;
1084         unsigned int i = 0;
1085         struct dm_target_spec *spec = (struct dm_target_spec *) param;
1086         uint32_t next = param->data_start;
1087         void *end = (void *) param + param_size;
1088         char *target_params;
1089
1090         if (!param->target_count) {
1091                 DMWARN("populate_table: no targets specified");
1092                 return -EINVAL;
1093         }
1094
1095         for (i = 0; i < param->target_count; i++) {
1096
1097                 r = next_target(spec, next, end, &spec, &target_params);
1098                 if (r) {
1099                         DMWARN("unable to find target");
1100                         return r;
1101                 }
1102
1103                 r = dm_table_add_target(table, spec->target_type,
1104                                         (sector_t) spec->sector_start,
1105                                         (sector_t) spec->length,
1106                                         target_params);
1107                 if (r) {
1108                         DMWARN("error adding target to table");
1109                         return r;
1110                 }
1111
1112                 next = spec->next;
1113         }
1114
1115         r = dm_table_set_type(table);
1116         if (r) {
1117                 DMWARN("unable to set table type");
1118                 return r;
1119         }
1120
1121         return dm_table_complete(table);
1122 }
1123
1124 static int table_prealloc_integrity(struct dm_table *t,
1125                                     struct mapped_device *md)
1126 {
1127         struct list_head *devices = dm_table_get_devices(t);
1128         struct dm_dev_internal *dd;
1129
1130         list_for_each_entry(dd, devices, list)
1131                 if (bdev_get_integrity(dd->dm_dev.bdev))
1132                         return blk_integrity_register(dm_disk(md), NULL);
1133
1134         return 0;
1135 }
1136
1137 static int table_load(struct dm_ioctl *param, size_t param_size)
1138 {
1139         int r;
1140         struct hash_cell *hc;
1141         struct dm_table *t;
1142         struct mapped_device *md;
1143
1144         md = find_device(param);
1145         if (!md)
1146                 return -ENXIO;
1147
1148         r = dm_table_create(&t, get_mode(param), param->target_count, md);
1149         if (r)
1150                 goto out;
1151
1152         r = populate_table(t, param, param_size);
1153         if (r) {
1154                 dm_table_destroy(t);
1155                 goto out;
1156         }
1157
1158         r = table_prealloc_integrity(t, md);
1159         if (r) {
1160                 DMERR("%s: could not register integrity profile.",
1161                       dm_device_name(md));
1162                 dm_table_destroy(t);
1163                 goto out;
1164         }
1165
1166         r = dm_table_alloc_md_mempools(t);
1167         if (r) {
1168                 DMWARN("unable to allocate mempools for this table");
1169                 dm_table_destroy(t);
1170                 goto out;
1171         }
1172
1173         down_write(&_hash_lock);
1174         hc = dm_get_mdptr(md);
1175         if (!hc || hc->md != md) {
1176                 DMWARN("device has been removed from the dev hash table.");
1177                 dm_table_destroy(t);
1178                 up_write(&_hash_lock);
1179                 r = -ENXIO;
1180                 goto out;
1181         }
1182
1183         if (hc->new_map)
1184                 dm_table_destroy(hc->new_map);
1185         hc->new_map = t;
1186         up_write(&_hash_lock);
1187
1188         param->flags |= DM_INACTIVE_PRESENT_FLAG;
1189         r = __dev_status(md, param);
1190
1191 out:
1192         dm_put(md);
1193
1194         return r;
1195 }
1196
1197 static int table_clear(struct dm_ioctl *param, size_t param_size)
1198 {
1199         int r;
1200         struct hash_cell *hc;
1201         struct mapped_device *md;
1202
1203         down_write(&_hash_lock);
1204
1205         hc = __find_device_hash_cell(param);
1206         if (!hc) {
1207                 DMWARN("device doesn't appear to be in the dev hash table.");
1208                 up_write(&_hash_lock);
1209                 return -ENXIO;
1210         }
1211
1212         if (hc->new_map) {
1213                 dm_table_destroy(hc->new_map);
1214                 hc->new_map = NULL;
1215         }
1216
1217         param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1218
1219         r = __dev_status(hc->md, param);
1220         md = hc->md;
1221         up_write(&_hash_lock);
1222         dm_put(md);
1223         return r;
1224 }
1225
1226 /*
1227  * Retrieves a list of devices used by a particular dm device.
1228  */
1229 static void retrieve_deps(struct dm_table *table,
1230                           struct dm_ioctl *param, size_t param_size)
1231 {
1232         unsigned int count = 0;
1233         struct list_head *tmp;
1234         size_t len, needed;
1235         struct dm_dev_internal *dd;
1236         struct dm_target_deps *deps;
1237
1238         deps = get_result_buffer(param, param_size, &len);
1239
1240         /*
1241          * Count the devices.
1242          */
1243         list_for_each (tmp, dm_table_get_devices(table))
1244                 count++;
1245
1246         /*
1247          * Check we have enough space.
1248          */
1249         needed = sizeof(*deps) + (sizeof(*deps->dev) * count);
1250         if (len < needed) {
1251                 param->flags |= DM_BUFFER_FULL_FLAG;
1252                 return;
1253         }
1254
1255         /*
1256          * Fill in the devices.
1257          */
1258         deps->count = count;
1259         count = 0;
1260         list_for_each_entry (dd, dm_table_get_devices(table), list)
1261                 deps->dev[count++] = huge_encode_dev(dd->dm_dev.bdev->bd_dev);
1262
1263         param->data_size = param->data_start + needed;
1264 }
1265
1266 static int table_deps(struct dm_ioctl *param, size_t param_size)
1267 {
1268         int r = 0;
1269         struct mapped_device *md;
1270         struct dm_table *table;
1271
1272         md = find_device(param);
1273         if (!md)
1274                 return -ENXIO;
1275
1276         r = __dev_status(md, param);
1277         if (r)
1278                 goto out;
1279
1280         table = dm_get_live_or_inactive_table(md, param);
1281         if (table) {
1282                 retrieve_deps(table, param, param_size);
1283                 dm_table_put(table);
1284         }
1285
1286  out:
1287         dm_put(md);
1288         return r;
1289 }
1290
1291 /*
1292  * Return the status of a device as a text string for each
1293  * target.
1294  */
1295 static int table_status(struct dm_ioctl *param, size_t param_size)
1296 {
1297         int r;
1298         struct mapped_device *md;
1299         struct dm_table *table;
1300
1301         md = find_device(param);
1302         if (!md)
1303                 return -ENXIO;
1304
1305         r = __dev_status(md, param);
1306         if (r)
1307                 goto out;
1308
1309         table = dm_get_live_or_inactive_table(md, param);
1310         if (table) {
1311                 retrieve_status(table, param, param_size);
1312                 dm_table_put(table);
1313         }
1314
1315 out:
1316         dm_put(md);
1317         return r;
1318 }
1319
1320 /*
1321  * Pass a message to the target that's at the supplied device offset.
1322  */
1323 static int target_message(struct dm_ioctl *param, size_t param_size)
1324 {
1325         int r, argc;
1326         char **argv;
1327         struct mapped_device *md;
1328         struct dm_table *table;
1329         struct dm_target *ti;
1330         struct dm_target_msg *tmsg = (void *) param + param->data_start;
1331
1332         md = find_device(param);
1333         if (!md)
1334                 return -ENXIO;
1335
1336         r = __dev_status(md, param);
1337         if (r)
1338                 goto out;
1339
1340         if (tmsg < (struct dm_target_msg *) param->data ||
1341             invalid_str(tmsg->message, (void *) param + param_size)) {
1342                 DMWARN("Invalid target message parameters.");
1343                 r = -EINVAL;
1344                 goto out;
1345         }
1346
1347         r = dm_split_args(&argc, &argv, tmsg->message);
1348         if (r) {
1349                 DMWARN("Failed to split target message parameters");
1350                 goto out;
1351         }
1352
1353         table = dm_get_live_table(md);
1354         if (!table)
1355                 goto out_argv;
1356
1357         if (dm_deleting_md(md)) {
1358                 r = -ENXIO;
1359                 goto out_table;
1360         }
1361
1362         ti = dm_table_find_target(table, tmsg->sector);
1363         if (!dm_target_is_valid(ti)) {
1364                 DMWARN("Target message sector outside device.");
1365                 r = -EINVAL;
1366         } else if (ti->type->message)
1367                 r = ti->type->message(ti, argc, argv);
1368         else {
1369                 DMWARN("Target type does not support messages");
1370                 r = -EINVAL;
1371         }
1372
1373  out_table:
1374         dm_table_put(table);
1375  out_argv:
1376         kfree(argv);
1377  out:
1378         param->data_size = 0;
1379         dm_put(md);
1380         return r;
1381 }
1382
1383 /*-----------------------------------------------------------------
1384  * Implementation of open/close/ioctl on the special char
1385  * device.
1386  *---------------------------------------------------------------*/
1387 static ioctl_fn lookup_ioctl(unsigned int cmd)
1388 {
1389         static struct {
1390                 int cmd;
1391                 ioctl_fn fn;
1392         } _ioctls[] = {
1393                 {DM_VERSION_CMD, NULL}, /* version is dealt with elsewhere */
1394                 {DM_REMOVE_ALL_CMD, remove_all},
1395                 {DM_LIST_DEVICES_CMD, list_devices},
1396
1397                 {DM_DEV_CREATE_CMD, dev_create},
1398                 {DM_DEV_REMOVE_CMD, dev_remove},
1399                 {DM_DEV_RENAME_CMD, dev_rename},
1400                 {DM_DEV_SUSPEND_CMD, dev_suspend},
1401                 {DM_DEV_STATUS_CMD, dev_status},
1402                 {DM_DEV_WAIT_CMD, dev_wait},
1403
1404                 {DM_TABLE_LOAD_CMD, table_load},
1405                 {DM_TABLE_CLEAR_CMD, table_clear},
1406                 {DM_TABLE_DEPS_CMD, table_deps},
1407                 {DM_TABLE_STATUS_CMD, table_status},
1408
1409                 {DM_LIST_VERSIONS_CMD, list_versions},
1410
1411                 {DM_TARGET_MSG_CMD, target_message},
1412                 {DM_DEV_SET_GEOMETRY_CMD, dev_set_geometry}
1413         };
1414
1415         return (cmd >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[cmd].fn;
1416 }
1417
1418 /*
1419  * As well as checking the version compatibility this always
1420  * copies the kernel interface version out.
1421  */
1422 static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
1423 {
1424         uint32_t version[3];
1425         int r = 0;
1426
1427         if (copy_from_user(version, user->version, sizeof(version)))
1428                 return -EFAULT;
1429
1430         if ((DM_VERSION_MAJOR != version[0]) ||
1431             (DM_VERSION_MINOR < version[1])) {
1432                 DMWARN("ioctl interface mismatch: "
1433                        "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
1434                        DM_VERSION_MAJOR, DM_VERSION_MINOR,
1435                        DM_VERSION_PATCHLEVEL,
1436                        version[0], version[1], version[2], cmd);
1437                 r = -EINVAL;
1438         }
1439
1440         /*
1441          * Fill in the kernel version.
1442          */
1443         version[0] = DM_VERSION_MAJOR;
1444         version[1] = DM_VERSION_MINOR;
1445         version[2] = DM_VERSION_PATCHLEVEL;
1446         if (copy_to_user(user->version, version, sizeof(version)))
1447                 return -EFAULT;
1448
1449         return r;
1450 }
1451
1452 static void free_params(struct dm_ioctl *param)
1453 {
1454         vfree(param);
1455 }
1456
1457 static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param)
1458 {
1459         struct dm_ioctl tmp, *dmi;
1460
1461         if (copy_from_user(&tmp, user, sizeof(tmp) - sizeof(tmp.data)))
1462                 return -EFAULT;
1463
1464         if (tmp.data_size < (sizeof(tmp) - sizeof(tmp.data)))
1465                 return -EINVAL;
1466
1467         dmi = vmalloc(tmp.data_size);
1468         if (!dmi)
1469                 return -ENOMEM;
1470
1471         if (copy_from_user(dmi, user, tmp.data_size)) {
1472                 vfree(dmi);
1473                 return -EFAULT;
1474         }
1475
1476         *param = dmi;
1477         return 0;
1478 }
1479
1480 static int validate_params(uint cmd, struct dm_ioctl *param)
1481 {
1482         /* Always clear this flag */
1483         param->flags &= ~DM_BUFFER_FULL_FLAG;
1484         param->flags &= ~DM_UEVENT_GENERATED_FLAG;
1485
1486         /* Ignores parameters */
1487         if (cmd == DM_REMOVE_ALL_CMD ||
1488             cmd == DM_LIST_DEVICES_CMD ||
1489             cmd == DM_LIST_VERSIONS_CMD)
1490                 return 0;
1491
1492         if ((cmd == DM_DEV_CREATE_CMD)) {
1493                 if (!*param->name) {
1494                         DMWARN("name not supplied when creating device");
1495                         return -EINVAL;
1496                 }
1497         } else if ((*param->uuid && *param->name)) {
1498                 DMWARN("only supply one of name or uuid, cmd(%u)", cmd);
1499                 return -EINVAL;
1500         }
1501
1502         /* Ensure strings are terminated */
1503         param->name[DM_NAME_LEN - 1] = '\0';
1504         param->uuid[DM_UUID_LEN - 1] = '\0';
1505
1506         return 0;
1507 }
1508
1509 static int ctl_ioctl(uint command, struct dm_ioctl __user *user)
1510 {
1511         int r = 0;
1512         unsigned int cmd;
1513         struct dm_ioctl *uninitialized_var(param);
1514         ioctl_fn fn = NULL;
1515         size_t param_size;
1516
1517         /* only root can play with this */
1518         if (!capable(CAP_SYS_ADMIN))
1519                 return -EACCES;
1520
1521         if (_IOC_TYPE(command) != DM_IOCTL)
1522                 return -ENOTTY;
1523
1524         cmd = _IOC_NR(command);
1525
1526         /*
1527          * Check the interface version passed in.  This also
1528          * writes out the kernel's interface version.
1529          */
1530         r = check_version(cmd, user);
1531         if (r)
1532                 return r;
1533
1534         /*
1535          * Nothing more to do for the version command.
1536          */
1537         if (cmd == DM_VERSION_CMD)
1538                 return 0;
1539
1540         fn = lookup_ioctl(cmd);
1541         if (!fn) {
1542                 DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);
1543                 return -ENOTTY;
1544         }
1545
1546         /*
1547          * Trying to avoid low memory issues when a device is
1548          * suspended.
1549          */
1550         current->flags |= PF_MEMALLOC;
1551
1552         /*
1553          * Copy the parameters into kernel space.
1554          */
1555         r = copy_params(user, &param);
1556
1557         current->flags &= ~PF_MEMALLOC;
1558
1559         if (r)
1560                 return r;
1561
1562         r = validate_params(cmd, param);
1563         if (r)
1564                 goto out;
1565
1566         param_size = param->data_size;
1567         param->data_size = sizeof(*param);
1568         r = fn(param, param_size);
1569
1570         /*
1571          * Copy the results back to userland.
1572          */
1573         if (!r && copy_to_user(user, param, param->data_size))
1574                 r = -EFAULT;
1575
1576  out:
1577         free_params(param);
1578         return r;
1579 }
1580
1581 static long dm_ctl_ioctl(struct file *file, uint command, ulong u)
1582 {
1583         return (long)ctl_ioctl(command, (struct dm_ioctl __user *)u);
1584 }
1585
1586 #ifdef CONFIG_COMPAT
1587 static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u)
1588 {
1589         return (long)dm_ctl_ioctl(file, command, (ulong) compat_ptr(u));
1590 }
1591 #else
1592 #define dm_compat_ctl_ioctl NULL
1593 #endif
1594
1595 static const struct file_operations _ctl_fops = {
1596         .unlocked_ioctl  = dm_ctl_ioctl,
1597         .compat_ioctl = dm_compat_ctl_ioctl,
1598         .owner   = THIS_MODULE,
1599 };
1600
1601 static struct miscdevice _dm_misc = {
1602         .minor          = MISC_DYNAMIC_MINOR,
1603         .name           = DM_NAME,
1604         .nodename       = "mapper/control",
1605         .fops           = &_ctl_fops
1606 };
1607
1608 /*
1609  * Create misc character device and link to DM_DIR/control.
1610  */
1611 int __init dm_interface_init(void)
1612 {
1613         int r;
1614
1615         r = dm_hash_init();
1616         if (r)
1617                 return r;
1618
1619         r = misc_register(&_dm_misc);
1620         if (r) {
1621                 DMERR("misc_register failed for control device");
1622                 dm_hash_exit();
1623                 return r;
1624         }
1625
1626         DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
1627                DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
1628                DM_DRIVER_EMAIL);
1629         return 0;
1630 }
1631
1632 void dm_interface_exit(void)
1633 {
1634         if (misc_deregister(&_dm_misc) < 0)
1635                 DMERR("misc_deregister failed for control device");
1636
1637         dm_hash_exit();
1638 }
1639
1640 /**
1641  * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers
1642  * @md: Pointer to mapped_device
1643  * @name: Buffer (size DM_NAME_LEN) for name
1644  * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined
1645  */
1646 int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
1647 {
1648         int r = 0;
1649         struct hash_cell *hc;
1650
1651         if (!md)
1652                 return -ENXIO;
1653
1654         mutex_lock(&dm_hash_cells_mutex);
1655         hc = dm_get_mdptr(md);
1656         if (!hc || hc->md != md) {
1657                 r = -ENXIO;
1658                 goto out;
1659         }
1660
1661         if (name)
1662                 strcpy(name, hc->name);
1663         if (uuid)
1664                 strcpy(uuid, hc->uuid ? : "");
1665
1666 out:
1667         mutex_unlock(&dm_hash_cells_mutex);
1668
1669         return r;
1670 }