drivers/md/dm-ioctl.c

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This source file includes following definitions.
init_buckets
dm_hash_init
dm_hash_exit
hash_str
__get_name_cell
__get_uuid_cell
__get_dev_cell
alloc_cell
free_cell
dm_hash_insert
__hash_remove
dm_hash_remove_all
__set_cell_uuid
__change_cell_name
dm_hash_rename
dm_deferred_remove
remove_all
align_val
align_ptr
get_result_buffer
list_devices
list_version_get_needed
list_version_get_info
__list_versions
list_versions
get_target_version
check_name
dm_get_inactive_table
dm_get_live_or_inactive_table
__dev_status
dev_create
__find_device_hash_cell
find_device
dev_remove
invalid_str
dev_rename
dev_set_geometry
do_suspend
do_resume
dev_suspend
dev_status
retrieve_status
dev_wait
dev_arm_poll
get_mode
next_target
populate_table
is_valid_type
table_load
table_clear
retrieve_deps
table_deps
table_status
message_for_md
target_message
lookup_ioctl
check_version
free_params
copy_params
validate_params
ctl_ioctl
dm_ctl_ioctl
dm_compat_ctl_ioctl
dm_open
dm_release
dm_poll
dm_interface_init
dm_interface_exit
dm_copy_name_and_uuid
dm_early_create
   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-core.h"
   9 
  10 #include <linux/module.h>
  11 #include <linux/vmalloc.h>
  12 #include <linux/miscdevice.h>
  13 #include <linux/sched/mm.h>
  14 #include <linux/init.h>
  15 #include <linux/wait.h>
  16 #include <linux/slab.h>
  17 #include <linux/dm-ioctl.h>
  18 #include <linux/hdreg.h>
  19 #include <linux/compat.h>
  20 
  21 #include <linux/uaccess.h>
  22 
  23 #define DM_MSG_PREFIX "ioctl"
  24 #define DM_DRIVER_EMAIL "dm-devel@redhat.com"
  25 
  26 struct dm_file {
  27         /*
  28          * poll will wait until the global event number is greater than
  29          * this value.
  30          */
  31         volatile unsigned global_event_nr;
  32 };
  33 
  34 /*-----------------------------------------------------------------
  35  * The ioctl interface needs to be able to look up devices by
  36  * name or uuid.
  37  *---------------------------------------------------------------*/
  38 struct hash_cell {
  39         struct list_head name_list;
  40         struct list_head uuid_list;
  41 
  42         char *name;
  43         char *uuid;
  44         struct mapped_device *md;
  45         struct dm_table *new_map;
  46 };
  47 
  48 struct vers_iter {
  49     size_t param_size;
  50     struct dm_target_versions *vers, *old_vers;
  51     char *end;
  52     uint32_t flags;
  53 };
  54 
  55 
  56 #define NUM_BUCKETS 64
  57 #define MASK_BUCKETS (NUM_BUCKETS - 1)
  58 static struct list_head _name_buckets[NUM_BUCKETS];
  59 static struct list_head _uuid_buckets[NUM_BUCKETS];
  60 
  61 static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred);
  62 
  63 /*
  64  * Guards access to both hash tables.
  65  */
  66 static DECLARE_RWSEM(_hash_lock);
  67 
  68 /*
  69  * Protects use of mdptr to obtain hash cell name and uuid from mapped device.
  70  */
  71 static DEFINE_MUTEX(dm_hash_cells_mutex);
  72 
  73 static void init_buckets(struct list_head *buckets)
  74 {
  75         unsigned int i;
  76 
  77         for (i = 0; i < NUM_BUCKETS; i++)
  78                 INIT_LIST_HEAD(buckets + i);
  79 }
  80 
  81 static int dm_hash_init(void)
  82 {
  83         init_buckets(_name_buckets);
  84         init_buckets(_uuid_buckets);
  85         return 0;
  86 }
  87 
  88 static void dm_hash_exit(void)
  89 {
  90         dm_hash_remove_all(false, false, false);
  91 }
  92 
  93 /*-----------------------------------------------------------------
  94  * Hash function:
  95  * We're not really concerned with the str hash function being
  96  * fast since it's only used by the ioctl interface.
  97  *---------------------------------------------------------------*/
  98 static unsigned int hash_str(const char *str)
  99 {
 100         const unsigned int hash_mult = 2654435387U;
 101         unsigned int h = 0;
 102 
 103         while (*str)
 104                 h = (h + (unsigned int) *str++) * hash_mult;
 105 
 106         return h & MASK_BUCKETS;
 107 }
 108 
 109 /*-----------------------------------------------------------------
 110  * Code for looking up a device by name
 111  *---------------------------------------------------------------*/
 112 static struct hash_cell *__get_name_cell(const char *str)
 113 {
 114         struct hash_cell *hc;
 115         unsigned int h = hash_str(str);
 116 
 117         list_for_each_entry (hc, _name_buckets + h, name_list)
 118                 if (!strcmp(hc->name, str)) {
 119                         dm_get(hc->md);
 120                         return hc;
 121                 }
 122 
 123         return NULL;
 124 }
 125 
 126 static struct hash_cell *__get_uuid_cell(const char *str)
 127 {
 128         struct hash_cell *hc;
 129         unsigned int h = hash_str(str);
 130 
 131         list_for_each_entry (hc, _uuid_buckets + h, uuid_list)
 132                 if (!strcmp(hc->uuid, str)) {
 133                         dm_get(hc->md);
 134                         return hc;
 135                 }
 136 
 137         return NULL;
 138 }
 139 
 140 static struct hash_cell *__get_dev_cell(uint64_t dev)
 141 {
 142         struct mapped_device *md;
 143         struct hash_cell *hc;
 144 
 145         md = dm_get_md(huge_decode_dev(dev));
 146         if (!md)
 147                 return NULL;
 148 
 149         hc = dm_get_mdptr(md);
 150         if (!hc) {
 151                 dm_put(md);
 152                 return NULL;
 153         }
 154 
 155         return hc;
 156 }
 157 
 158 /*-----------------------------------------------------------------
 159  * Inserting, removing and renaming a device.
 160  *---------------------------------------------------------------*/
 161 static struct hash_cell *alloc_cell(const char *name, const char *uuid,
 162                                     struct mapped_device *md)
 163 {
 164         struct hash_cell *hc;
 165 
 166         hc = kmalloc(sizeof(*hc), GFP_KERNEL);
 167         if (!hc)
 168                 return NULL;
 169 
 170         hc->name = kstrdup(name, GFP_KERNEL);
 171         if (!hc->name) {
 172                 kfree(hc);
 173                 return NULL;
 174         }
 175 
 176         if (!uuid)
 177                 hc->uuid = NULL;
 178 
 179         else {
 180                 hc->uuid = kstrdup(uuid, GFP_KERNEL);
 181                 if (!hc->uuid) {
 182                         kfree(hc->name);
 183                         kfree(hc);
 184                         return NULL;
 185                 }
 186         }
 187 
 188         INIT_LIST_HEAD(&hc->name_list);
 189         INIT_LIST_HEAD(&hc->uuid_list);
 190         hc->md = md;
 191         hc->new_map = NULL;
 192         return hc;
 193 }
 194 
 195 static void free_cell(struct hash_cell *hc)
 196 {
 197         if (hc) {
 198                 kfree(hc->name);
 199                 kfree(hc->uuid);
 200                 kfree(hc);
 201         }
 202 }
 203 
 204 /*
 205  * The kdev_t and uuid of a device can never change once it is
 206  * initially inserted.
 207  */
 208 static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md)
 209 {
 210         struct hash_cell *cell, *hc;
 211 
 212         /*
 213          * Allocate the new cells.
 214          */
 215         cell = alloc_cell(name, uuid, md);
 216         if (!cell)
 217                 return -ENOMEM;
 218 
 219         /*
 220          * Insert the cell into both hash tables.
 221          */
 222         down_write(&_hash_lock);
 223         hc = __get_name_cell(name);
 224         if (hc) {
 225                 dm_put(hc->md);
 226                 goto bad;
 227         }
 228 
 229         list_add(&cell->name_list, _name_buckets + hash_str(name));
 230 
 231         if (uuid) {
 232                 hc = __get_uuid_cell(uuid);
 233                 if (hc) {
 234                         list_del(&cell->name_list);
 235                         dm_put(hc->md);
 236                         goto bad;
 237                 }
 238                 list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid));
 239         }
 240         dm_get(md);
 241         mutex_lock(&dm_hash_cells_mutex);
 242         dm_set_mdptr(md, cell);
 243         mutex_unlock(&dm_hash_cells_mutex);
 244         up_write(&_hash_lock);
 245 
 246         return 0;
 247 
 248  bad:
 249         up_write(&_hash_lock);
 250         free_cell(cell);
 251         return -EBUSY;
 252 }
 253 
 254 static struct dm_table *__hash_remove(struct hash_cell *hc)
 255 {
 256         struct dm_table *table;
 257         int srcu_idx;
 258 
 259         /* remove from the dev hash */
 260         list_del(&hc->uuid_list);
 261         list_del(&hc->name_list);
 262         mutex_lock(&dm_hash_cells_mutex);
 263         dm_set_mdptr(hc->md, NULL);
 264         mutex_unlock(&dm_hash_cells_mutex);
 265 
 266         table = dm_get_live_table(hc->md, &srcu_idx);
 267         if (table)
 268                 dm_table_event(table);
 269         dm_put_live_table(hc->md, srcu_idx);
 270 
 271         table = NULL;
 272         if (hc->new_map)
 273                 table = hc->new_map;
 274         dm_put(hc->md);
 275         free_cell(hc);
 276 
 277         return table;
 278 }
 279 
 280 static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred)
 281 {
 282         int i, dev_skipped;
 283         struct hash_cell *hc;
 284         struct mapped_device *md;
 285         struct dm_table *t;
 286 
 287 retry:
 288         dev_skipped = 0;
 289 
 290         down_write(&_hash_lock);
 291 
 292         for (i = 0; i < NUM_BUCKETS; i++) {
 293                 list_for_each_entry(hc, _name_buckets + i, name_list) {
 294                         md = hc->md;
 295                         dm_get(md);
 296 
 297                         if (keep_open_devices &&
 298                             dm_lock_for_deletion(md, mark_deferred, only_deferred)) {
 299                                 dm_put(md);
 300                                 dev_skipped++;
 301                                 continue;
 302                         }
 303 
 304                         t = __hash_remove(hc);
 305 
 306                         up_write(&_hash_lock);
 307 
 308                         if (t) {
 309                                 dm_sync_table(md);
 310                                 dm_table_destroy(t);
 311                         }
 312                         dm_put(md);
 313                         if (likely(keep_open_devices))
 314                                 dm_destroy(md);
 315                         else
 316                                 dm_destroy_immediate(md);
 317 
 318                         /*
 319                          * Some mapped devices may be using other mapped
 320                          * devices, so repeat until we make no further
 321                          * progress.  If a new mapped device is created
 322                          * here it will also get removed.
 323                          */
 324                         goto retry;
 325                 }
 326         }
 327 
 328         up_write(&_hash_lock);
 329 
 330         if (dev_skipped)
 331                 DMWARN("remove_all left %d open device(s)", dev_skipped);
 332 }
 333 
 334 /*
 335  * Set the uuid of a hash_cell that isn't already set.
 336  */
 337 static void __set_cell_uuid(struct hash_cell *hc, char *new_uuid)
 338 {
 339         mutex_lock(&dm_hash_cells_mutex);
 340         hc->uuid = new_uuid;
 341         mutex_unlock(&dm_hash_cells_mutex);
 342 
 343         list_add(&hc->uuid_list, _uuid_buckets + hash_str(new_uuid));
 344 }
 345 
 346 /*
 347  * Changes the name of a hash_cell and returns the old name for
 348  * the caller to free.
 349  */
 350 static char *__change_cell_name(struct hash_cell *hc, char *new_name)
 351 {
 352         char *old_name;
 353 
 354         /*
 355          * Rename and move the name cell.
 356          */
 357         list_del(&hc->name_list);
 358         old_name = hc->name;
 359 
 360         mutex_lock(&dm_hash_cells_mutex);
 361         hc->name = new_name;
 362         mutex_unlock(&dm_hash_cells_mutex);
 363 
 364         list_add(&hc->name_list, _name_buckets + hash_str(new_name));
 365 
 366         return old_name;
 367 }
 368 
 369 static struct mapped_device *dm_hash_rename(struct dm_ioctl *param,
 370                                             const char *new)
 371 {
 372         char *new_data, *old_name = NULL;
 373         struct hash_cell *hc;
 374         struct dm_table *table;
 375         struct mapped_device *md;
 376         unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
 377         int srcu_idx;
 378 
 379         /*
 380          * duplicate new.
 381          */
 382         new_data = kstrdup(new, GFP_KERNEL);
 383         if (!new_data)
 384                 return ERR_PTR(-ENOMEM);
 385 
 386         down_write(&_hash_lock);
 387 
 388         /*
 389          * Is new free ?
 390          */
 391         if (change_uuid)
 392                 hc = __get_uuid_cell(new);
 393         else
 394                 hc = __get_name_cell(new);
 395 
 396         if (hc) {
 397                 DMWARN("Unable to change %s on mapped device %s to one that "
 398                        "already exists: %s",
 399                        change_uuid ? "uuid" : "name",
 400                        param->name, new);
 401                 dm_put(hc->md);
 402                 up_write(&_hash_lock);
 403                 kfree(new_data);
 404                 return ERR_PTR(-EBUSY);
 405         }
 406 
 407         /*
 408          * Is there such a device as 'old' ?
 409          */
 410         hc = __get_name_cell(param->name);
 411         if (!hc) {
 412                 DMWARN("Unable to rename non-existent device, %s to %s%s",
 413                        param->name, change_uuid ? "uuid " : "", new);
 414                 up_write(&_hash_lock);
 415                 kfree(new_data);
 416                 return ERR_PTR(-ENXIO);
 417         }
 418 
 419         /*
 420          * Does this device already have a uuid?
 421          */
 422         if (change_uuid && hc->uuid) {
 423                 DMWARN("Unable to change uuid of mapped device %s to %s "
 424                        "because uuid is already set to %s",
 425                        param->name, new, hc->uuid);
 426                 dm_put(hc->md);
 427                 up_write(&_hash_lock);
 428                 kfree(new_data);
 429                 return ERR_PTR(-EINVAL);
 430         }
 431 
 432         if (change_uuid)
 433                 __set_cell_uuid(hc, new_data);
 434         else
 435                 old_name = __change_cell_name(hc, new_data);
 436 
 437         /*
 438          * Wake up any dm event waiters.
 439          */
 440         table = dm_get_live_table(hc->md, &srcu_idx);
 441         if (table)
 442                 dm_table_event(table);
 443         dm_put_live_table(hc->md, srcu_idx);
 444 
 445         if (!dm_kobject_uevent(hc->md, KOBJ_CHANGE, param->event_nr))
 446                 param->flags |= DM_UEVENT_GENERATED_FLAG;
 447 
 448         md = hc->md;
 449         up_write(&_hash_lock);
 450         kfree(old_name);
 451 
 452         return md;
 453 }
 454 
 455 void dm_deferred_remove(void)
 456 {
 457         dm_hash_remove_all(true, false, true);
 458 }
 459 
 460 /*-----------------------------------------------------------------
 461  * Implementation of the ioctl commands
 462  *---------------------------------------------------------------*/
 463 /*
 464  * All the ioctl commands get dispatched to functions with this
 465  * prototype.
 466  */
 467 typedef int (*ioctl_fn)(struct file *filp, struct dm_ioctl *param, size_t param_size);
 468 
 469 static int remove_all(struct file *filp, struct dm_ioctl *param, size_t param_size)
 470 {
 471         dm_hash_remove_all(true, !!(param->flags & DM_DEFERRED_REMOVE), false);
 472         param->data_size = 0;
 473         return 0;
 474 }
 475 
 476 /*
 477  * Round up the ptr to an 8-byte boundary.
 478  */
 479 #define ALIGN_MASK 7
 480 static inline size_t align_val(size_t val)
 481 {
 482         return (val + ALIGN_MASK) & ~ALIGN_MASK;
 483 }
 484 static inline void *align_ptr(void *ptr)
 485 {
 486         return (void *)align_val((size_t)ptr);
 487 }
 488 
 489 /*
 490  * Retrieves the data payload buffer from an already allocated
 491  * struct dm_ioctl.
 492  */
 493 static void *get_result_buffer(struct dm_ioctl *param, size_t param_size,
 494                                size_t *len)
 495 {
 496         param->data_start = align_ptr(param + 1) - (void *) param;
 497 
 498         if (param->data_start < param_size)
 499                 *len = param_size - param->data_start;
 500         else
 501                 *len = 0;
 502 
 503         return ((void *) param) + param->data_start;
 504 }
 505 
 506 static int list_devices(struct file *filp, struct dm_ioctl *param, size_t param_size)
 507 {
 508         unsigned int i;
 509         struct hash_cell *hc;
 510         size_t len, needed = 0;
 511         struct gendisk *disk;
 512         struct dm_name_list *orig_nl, *nl, *old_nl = NULL;
 513         uint32_t *event_nr;
 514 
 515         down_write(&_hash_lock);
 516 
 517         /*
 518          * Loop through all the devices working out how much
 519          * space we need.
 520          */
 521         for (i = 0; i < NUM_BUCKETS; i++) {
 522                 list_for_each_entry (hc, _name_buckets + i, name_list) {
 523                         needed += align_val(offsetof(struct dm_name_list, name) + strlen(hc->name) + 1);
 524                         needed += align_val(sizeof(uint32_t));
 525                 }
 526         }
 527 
 528         /*
 529          * Grab our output buffer.
 530          */
 531         nl = orig_nl = get_result_buffer(param, param_size, &len);
 532         if (len < needed) {
 533                 param->flags |= DM_BUFFER_FULL_FLAG;
 534                 goto out;
 535         }
 536         param->data_size = param->data_start + needed;
 537 
 538         nl->dev = 0;    /* Flags no data */
 539 
 540         /*
 541          * Now loop through filling out the names.
 542          */
 543         for (i = 0; i < NUM_BUCKETS; i++) {
 544                 list_for_each_entry (hc, _name_buckets + i, name_list) {
 545                         if (old_nl)
 546                                 old_nl->next = (uint32_t) ((void *) nl -
 547                                                            (void *) old_nl);
 548                         disk = dm_disk(hc->md);
 549                         nl->dev = huge_encode_dev(disk_devt(disk));
 550                         nl->next = 0;
 551                         strcpy(nl->name, hc->name);
 552 
 553                         old_nl = nl;
 554                         event_nr = align_ptr(nl->name + strlen(hc->name) + 1);
 555                         *event_nr = dm_get_event_nr(hc->md);
 556                         nl = align_ptr(event_nr + 1);
 557                 }
 558         }
 559         /*
 560          * If mismatch happens, security may be compromised due to buffer
 561          * overflow, so it's better to crash.
 562          */
 563         BUG_ON((char *)nl - (char *)orig_nl != needed);
 564 
 565  out:
 566         up_write(&_hash_lock);
 567         return 0;
 568 }
 569 
 570 static void list_version_get_needed(struct target_type *tt, void *needed_param)
 571 {
 572     size_t *needed = needed_param;
 573 
 574     *needed += sizeof(struct dm_target_versions);
 575     *needed += strlen(tt->name);
 576     *needed += ALIGN_MASK;
 577 }
 578 
 579 static void list_version_get_info(struct target_type *tt, void *param)
 580 {
 581     struct vers_iter *info = param;
 582 
 583     /* Check space - it might have changed since the first iteration */
 584     if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 >
 585         info->end) {
 586 
 587         info->flags = DM_BUFFER_FULL_FLAG;
 588         return;
 589     }
 590 
 591     if (info->old_vers)
 592         info->old_vers->next = (uint32_t) ((void *)info->vers -
 593                                            (void *)info->old_vers);
 594     info->vers->version[0] = tt->version[0];
 595     info->vers->version[1] = tt->version[1];
 596     info->vers->version[2] = tt->version[2];
 597     info->vers->next = 0;
 598     strcpy(info->vers->name, tt->name);
 599 
 600     info->old_vers = info->vers;
 601     info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1);
 602 }
 603 
 604 static int __list_versions(struct dm_ioctl *param, size_t param_size, const char *name)
 605 {
 606         size_t len, needed = 0;
 607         struct dm_target_versions *vers;
 608         struct vers_iter iter_info;
 609         struct target_type *tt = NULL;
 610 
 611         if (name) {
 612                 tt = dm_get_target_type(name);
 613                 if (!tt)
 614                         return -EINVAL;
 615         }
 616 
 617         /*
 618          * Loop through all the devices working out how much
 619          * space we need.
 620          */
 621         if (!tt)
 622                 dm_target_iterate(list_version_get_needed, &needed);
 623         else
 624                 list_version_get_needed(tt, &needed);
 625 
 626         /*
 627          * Grab our output buffer.
 628          */
 629         vers = get_result_buffer(param, param_size, &len);
 630         if (len < needed) {
 631                 param->flags |= DM_BUFFER_FULL_FLAG;
 632                 goto out;
 633         }
 634         param->data_size = param->data_start + needed;
 635 
 636         iter_info.param_size = param_size;
 637         iter_info.old_vers = NULL;
 638         iter_info.vers = vers;
 639         iter_info.flags = 0;
 640         iter_info.end = (char *)vers+len;
 641 
 642         /*
 643          * Now loop through filling out the names & versions.
 644          */
 645         if (!tt)
 646                 dm_target_iterate(list_version_get_info, &iter_info);
 647         else
 648                 list_version_get_info(tt, &iter_info);
 649         param->flags |= iter_info.flags;
 650 
 651  out:
 652         if (tt)
 653                 dm_put_target_type(tt);
 654         return 0;
 655 }
 656 
 657 static int list_versions(struct file *filp, struct dm_ioctl *param, size_t param_size)
 658 {
 659         return __list_versions(param, param_size, NULL);
 660 }
 661 
 662 static int get_target_version(struct file *filp, struct dm_ioctl *param, size_t param_size)
 663 {
 664         return __list_versions(param, param_size, param->name);
 665 }
 666 
 667 static int check_name(const char *name)
 668 {
 669         if (strchr(name, '/')) {
 670                 DMWARN("invalid device name");
 671                 return -EINVAL;
 672         }
 673 
 674         return 0;
 675 }
 676 
 677 /*
 678  * On successful return, the caller must not attempt to acquire
 679  * _hash_lock without first calling dm_put_live_table, because dm_table_destroy
 680  * waits for this dm_put_live_table and could be called under this lock.
 681  */
 682 static struct dm_table *dm_get_inactive_table(struct mapped_device *md, int *srcu_idx)
 683 {
 684         struct hash_cell *hc;
 685         struct dm_table *table = NULL;
 686 
 687         /* increment rcu count, we don't care about the table pointer */
 688         dm_get_live_table(md, srcu_idx);
 689 
 690         down_read(&_hash_lock);
 691         hc = dm_get_mdptr(md);
 692         if (!hc || hc->md != md) {
 693                 DMWARN("device has been removed from the dev hash table.");
 694                 goto out;
 695         }
 696 
 697         table = hc->new_map;
 698 
 699 out:
 700         up_read(&_hash_lock);
 701 
 702         return table;
 703 }
 704 
 705 static struct dm_table *dm_get_live_or_inactive_table(struct mapped_device *md,
 706                                                       struct dm_ioctl *param,
 707                                                       int *srcu_idx)
 708 {
 709         return (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) ?
 710                 dm_get_inactive_table(md, srcu_idx) : dm_get_live_table(md, srcu_idx);
 711 }
 712 
 713 /*
 714  * Fills in a dm_ioctl structure, ready for sending back to
 715  * userland.
 716  */
 717 static void __dev_status(struct mapped_device *md, struct dm_ioctl *param)
 718 {
 719         struct gendisk *disk = dm_disk(md);
 720         struct dm_table *table;
 721         int srcu_idx;
 722 
 723         param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG |
 724                           DM_ACTIVE_PRESENT_FLAG | DM_INTERNAL_SUSPEND_FLAG);
 725 
 726         if (dm_suspended_md(md))
 727                 param->flags |= DM_SUSPEND_FLAG;
 728 
 729         if (dm_suspended_internally_md(md))
 730                 param->flags |= DM_INTERNAL_SUSPEND_FLAG;
 731 
 732         if (dm_test_deferred_remove_flag(md))
 733                 param->flags |= DM_DEFERRED_REMOVE;
 734 
 735         param->dev = huge_encode_dev(disk_devt(disk));
 736 
 737         /*
 738          * Yes, this will be out of date by the time it gets back
 739          * to userland, but it is still very useful for
 740          * debugging.
 741          */
 742         param->open_count = dm_open_count(md);
 743 
 744         param->event_nr = dm_get_event_nr(md);
 745         param->target_count = 0;
 746 
 747         table = dm_get_live_table(md, &srcu_idx);
 748         if (table) {
 749                 if (!(param->flags & DM_QUERY_INACTIVE_TABLE_FLAG)) {
 750                         if (get_disk_ro(disk))
 751                                 param->flags |= DM_READONLY_FLAG;
 752                         param->target_count = dm_table_get_num_targets(table);
 753                 }
 754 
 755                 param->flags |= DM_ACTIVE_PRESENT_FLAG;
 756         }
 757         dm_put_live_table(md, srcu_idx);
 758 
 759         if (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) {
 760                 int srcu_idx;
 761                 table = dm_get_inactive_table(md, &srcu_idx);
 762                 if (table) {
 763                         if (!(dm_table_get_mode(table) & FMODE_WRITE))
 764                                 param->flags |= DM_READONLY_FLAG;
 765                         param->target_count = dm_table_get_num_targets(table);
 766                 }
 767                 dm_put_live_table(md, srcu_idx);
 768         }
 769 }
 770 
 771 static int dev_create(struct file *filp, struct dm_ioctl *param, size_t param_size)
 772 {
 773         int r, m = DM_ANY_MINOR;
 774         struct mapped_device *md;
 775 
 776         r = check_name(param->name);
 777         if (r)
 778                 return r;
 779 
 780         if (param->flags & DM_PERSISTENT_DEV_FLAG)
 781                 m = MINOR(huge_decode_dev(param->dev));
 782 
 783         r = dm_create(m, &md);
 784         if (r)
 785                 return r;
 786 
 787         r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md);
 788         if (r) {
 789                 dm_put(md);
 790                 dm_destroy(md);
 791                 return r;
 792         }
 793 
 794         param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
 795 
 796         __dev_status(md, param);
 797 
 798         dm_put(md);
 799 
 800         return 0;
 801 }
 802 
 803 /*
 804  * Always use UUID for lookups if it's present, otherwise use name or dev.
 805  */
 806 static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param)
 807 {
 808         struct hash_cell *hc = NULL;
 809 
 810         if (*param->uuid) {
 811                 if (*param->name || param->dev)
 812                         return NULL;
 813 
 814                 hc = __get_uuid_cell(param->uuid);
 815                 if (!hc)
 816                         return NULL;
 817         } else if (*param->name) {
 818                 if (param->dev)
 819                         return NULL;
 820 
 821                 hc = __get_name_cell(param->name);
 822                 if (!hc)
 823                         return NULL;
 824         } else if (param->dev) {
 825                 hc = __get_dev_cell(param->dev);
 826                 if (!hc)
 827                         return NULL;
 828         } else
 829                 return NULL;
 830 
 831         /*
 832          * Sneakily write in both the name and the uuid
 833          * while we have the cell.
 834          */
 835         strlcpy(param->name, hc->name, sizeof(param->name));
 836         if (hc->uuid)
 837                 strlcpy(param->uuid, hc->uuid, sizeof(param->uuid));
 838         else
 839                 param->uuid[0] = '\0';
 840 
 841         if (hc->new_map)
 842                 param->flags |= DM_INACTIVE_PRESENT_FLAG;
 843         else
 844                 param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
 845 
 846         return hc;
 847 }
 848 
 849 static struct mapped_device *find_device(struct dm_ioctl *param)
 850 {
 851         struct hash_cell *hc;
 852         struct mapped_device *md = NULL;
 853 
 854         down_read(&_hash_lock);
 855         hc = __find_device_hash_cell(param);
 856         if (hc)
 857                 md = hc->md;
 858         up_read(&_hash_lock);
 859 
 860         return md;
 861 }
 862 
 863 static int dev_remove(struct file *filp, struct dm_ioctl *param, size_t param_size)
 864 {
 865         struct hash_cell *hc;
 866         struct mapped_device *md;
 867         int r;
 868         struct dm_table *t;
 869 
 870         down_write(&_hash_lock);
 871         hc = __find_device_hash_cell(param);
 872 
 873         if (!hc) {
 874                 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
 875                 up_write(&_hash_lock);
 876                 return -ENXIO;
 877         }
 878 
 879         md = hc->md;
 880 
 881         /*
 882          * Ensure the device is not open and nothing further can open it.
 883          */
 884         r = dm_lock_for_deletion(md, !!(param->flags & DM_DEFERRED_REMOVE), false);
 885         if (r) {
 886                 if (r == -EBUSY && param->flags & DM_DEFERRED_REMOVE) {
 887                         up_write(&_hash_lock);
 888                         dm_put(md);
 889                         return 0;
 890                 }
 891                 DMDEBUG_LIMIT("unable to remove open device %s", hc->name);
 892                 up_write(&_hash_lock);
 893                 dm_put(md);
 894                 return r;
 895         }
 896 
 897         t = __hash_remove(hc);
 898         up_write(&_hash_lock);
 899 
 900         if (t) {
 901                 dm_sync_table(md);
 902                 dm_table_destroy(t);
 903         }
 904 
 905         param->flags &= ~DM_DEFERRED_REMOVE;
 906 
 907         if (!dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr))
 908                 param->flags |= DM_UEVENT_GENERATED_FLAG;
 909 
 910         dm_put(md);
 911         dm_destroy(md);
 912         return 0;
 913 }
 914 
 915 /*
 916  * Check a string doesn't overrun the chunk of
 917  * memory we copied from userland.
 918  */
 919 static int invalid_str(char *str, void *end)
 920 {
 921         while ((void *) str < end)
 922                 if (!*str++)
 923                         return 0;
 924 
 925         return -EINVAL;
 926 }
 927 
 928 static int dev_rename(struct file *filp, struct dm_ioctl *param, size_t param_size)
 929 {
 930         int r;
 931         char *new_data = (char *) param + param->data_start;
 932         struct mapped_device *md;
 933         unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0;
 934 
 935         if (new_data < param->data ||
 936             invalid_str(new_data, (void *) param + param_size) || !*new_data ||
 937             strlen(new_data) > (change_uuid ? DM_UUID_LEN - 1 : DM_NAME_LEN - 1)) {
 938                 DMWARN("Invalid new mapped device name or uuid string supplied.");
 939                 return -EINVAL;
 940         }
 941 
 942         if (!change_uuid) {
 943                 r = check_name(new_data);
 944                 if (r)
 945                         return r;
 946         }
 947 
 948         md = dm_hash_rename(param, new_data);
 949         if (IS_ERR(md))
 950                 return PTR_ERR(md);
 951 
 952         __dev_status(md, param);
 953         dm_put(md);
 954 
 955         return 0;
 956 }
 957 
 958 static int dev_set_geometry(struct file *filp, struct dm_ioctl *param, size_t param_size)
 959 {
 960         int r = -EINVAL, x;
 961         struct mapped_device *md;
 962         struct hd_geometry geometry;
 963         unsigned long indata[4];
 964         char *geostr = (char *) param + param->data_start;
 965         char dummy;
 966 
 967         md = find_device(param);
 968         if (!md)
 969                 return -ENXIO;
 970 
 971         if (geostr < param->data ||
 972             invalid_str(geostr, (void *) param + param_size)) {
 973                 DMWARN("Invalid geometry supplied.");
 974                 goto out;
 975         }
 976 
 977         x = sscanf(geostr, "%lu %lu %lu %lu%c", indata,
 978                    indata + 1, indata + 2, indata + 3, &dummy);
 979 
 980         if (x != 4) {
 981                 DMWARN("Unable to interpret geometry settings.");
 982                 goto out;
 983         }
 984 
 985         if (indata[0] > 65535 || indata[1] > 255 ||
 986             indata[2] > 255 || indata[3] > ULONG_MAX) {
 987                 DMWARN("Geometry exceeds range limits.");
 988                 goto out;
 989         }
 990 
 991         geometry.cylinders = indata[0];
 992         geometry.heads = indata[1];
 993         geometry.sectors = indata[2];
 994         geometry.start = indata[3];
 995 
 996         r = dm_set_geometry(md, &geometry);
 997 
 998         param->data_size = 0;
 999 
1000 out:
1001         dm_put(md);
1002         return r;
1003 }
1004 
1005 static int do_suspend(struct dm_ioctl *param)
1006 {
1007         int r = 0;
1008         unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
1009         struct mapped_device *md;
1010 
1011         md = find_device(param);
1012         if (!md)
1013                 return -ENXIO;
1014 
1015         if (param->flags & DM_SKIP_LOCKFS_FLAG)
1016                 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
1017         if (param->flags & DM_NOFLUSH_FLAG)
1018                 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
1019 
1020         if (!dm_suspended_md(md)) {
1021                 r = dm_suspend(md, suspend_flags);
1022                 if (r)
1023                         goto out;
1024         }
1025 
1026         __dev_status(md, param);
1027 
1028 out:
1029         dm_put(md);
1030 
1031         return r;
1032 }
1033 
1034 static int do_resume(struct dm_ioctl *param)
1035 {
1036         int r = 0;
1037         unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG;
1038         struct hash_cell *hc;
1039         struct mapped_device *md;
1040         struct dm_table *new_map, *old_map = NULL;
1041 
1042         down_write(&_hash_lock);
1043 
1044         hc = __find_device_hash_cell(param);
1045         if (!hc) {
1046                 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1047                 up_write(&_hash_lock);
1048                 return -ENXIO;
1049         }
1050 
1051         md = hc->md;
1052 
1053         new_map = hc->new_map;
1054         hc->new_map = NULL;
1055         param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1056 
1057         up_write(&_hash_lock);
1058 
1059         /* Do we need to load a new map ? */
1060         if (new_map) {
1061                 /* Suspend if it isn't already suspended */
1062                 if (param->flags & DM_SKIP_LOCKFS_FLAG)
1063                         suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG;
1064                 if (param->flags & DM_NOFLUSH_FLAG)
1065                         suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG;
1066                 if (!dm_suspended_md(md))
1067                         dm_suspend(md, suspend_flags);
1068 
1069                 old_map = dm_swap_table(md, new_map);
1070                 if (IS_ERR(old_map)) {
1071                         dm_sync_table(md);
1072                         dm_table_destroy(new_map);
1073                         dm_put(md);
1074                         return PTR_ERR(old_map);
1075                 }
1076 
1077                 if (dm_table_get_mode(new_map) & FMODE_WRITE)
1078                         set_disk_ro(dm_disk(md), 0);
1079                 else
1080                         set_disk_ro(dm_disk(md), 1);
1081         }
1082 
1083         if (dm_suspended_md(md)) {
1084                 r = dm_resume(md);
1085                 if (!r && !dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr))
1086                         param->flags |= DM_UEVENT_GENERATED_FLAG;
1087         }
1088 
1089         /*
1090          * Since dm_swap_table synchronizes RCU, nobody should be in
1091          * read-side critical section already.
1092          */
1093         if (old_map)
1094                 dm_table_destroy(old_map);
1095 
1096         if (!r)
1097                 __dev_status(md, param);
1098 
1099         dm_put(md);
1100         return r;
1101 }
1102 
1103 /*
1104  * Set or unset the suspension state of a device.
1105  * If the device already is in the requested state we just return its status.
1106  */
1107 static int dev_suspend(struct file *filp, struct dm_ioctl *param, size_t param_size)
1108 {
1109         if (param->flags & DM_SUSPEND_FLAG)
1110                 return do_suspend(param);
1111 
1112         return do_resume(param);
1113 }
1114 
1115 /*
1116  * Copies device info back to user space, used by
1117  * the create and info ioctls.
1118  */
1119 static int dev_status(struct file *filp, struct dm_ioctl *param, size_t param_size)
1120 {
1121         struct mapped_device *md;
1122 
1123         md = find_device(param);
1124         if (!md)
1125                 return -ENXIO;
1126 
1127         __dev_status(md, param);
1128         dm_put(md);
1129 
1130         return 0;
1131 }
1132 
1133 /*
1134  * Build up the status struct for each target
1135  */
1136 static void retrieve_status(struct dm_table *table,
1137                             struct dm_ioctl *param, size_t param_size)
1138 {
1139         unsigned int i, num_targets;
1140         struct dm_target_spec *spec;
1141         char *outbuf, *outptr;
1142         status_type_t type;
1143         size_t remaining, len, used = 0;
1144         unsigned status_flags = 0;
1145 
1146         outptr = outbuf = get_result_buffer(param, param_size, &len);
1147 
1148         if (param->flags & DM_STATUS_TABLE_FLAG)
1149                 type = STATUSTYPE_TABLE;
1150         else
1151                 type = STATUSTYPE_INFO;
1152 
1153         /* Get all the target info */
1154         num_targets = dm_table_get_num_targets(table);
1155         for (i = 0; i < num_targets; i++) {
1156                 struct dm_target *ti = dm_table_get_target(table, i);
1157                 size_t l;
1158 
1159                 remaining = len - (outptr - outbuf);
1160                 if (remaining <= sizeof(struct dm_target_spec)) {
1161                         param->flags |= DM_BUFFER_FULL_FLAG;
1162                         break;
1163                 }
1164 
1165                 spec = (struct dm_target_spec *) outptr;
1166 
1167                 spec->status = 0;
1168                 spec->sector_start = ti->begin;
1169                 spec->length = ti->len;
1170                 strncpy(spec->target_type, ti->type->name,
1171                         sizeof(spec->target_type));
1172 
1173                 outptr += sizeof(struct dm_target_spec);
1174                 remaining = len - (outptr - outbuf);
1175                 if (remaining <= 0) {
1176                         param->flags |= DM_BUFFER_FULL_FLAG;
1177                         break;
1178                 }
1179 
1180                 /* Get the status/table string from the target driver */
1181                 if (ti->type->status) {
1182                         if (param->flags & DM_NOFLUSH_FLAG)
1183                                 status_flags |= DM_STATUS_NOFLUSH_FLAG;
1184                         ti->type->status(ti, type, status_flags, outptr, remaining);
1185                 } else
1186                         outptr[0] = '\0';
1187 
1188                 l = strlen(outptr) + 1;
1189                 if (l == remaining) {
1190                         param->flags |= DM_BUFFER_FULL_FLAG;
1191                         break;
1192                 }
1193 
1194                 outptr += l;
1195                 used = param->data_start + (outptr - outbuf);
1196 
1197                 outptr = align_ptr(outptr);
1198                 spec->next = outptr - outbuf;
1199         }
1200 
1201         if (used)
1202                 param->data_size = used;
1203 
1204         param->target_count = num_targets;
1205 }
1206 
1207 /*
1208  * Wait for a device to report an event
1209  */
1210 static int dev_wait(struct file *filp, struct dm_ioctl *param, size_t param_size)
1211 {
1212         int r = 0;
1213         struct mapped_device *md;
1214         struct dm_table *table;
1215         int srcu_idx;
1216 
1217         md = find_device(param);
1218         if (!md)
1219                 return -ENXIO;
1220 
1221         /*
1222          * Wait for a notification event
1223          */
1224         if (dm_wait_event(md, param->event_nr)) {
1225                 r = -ERESTARTSYS;
1226                 goto out;
1227         }
1228 
1229         /*
1230          * The userland program is going to want to know what
1231          * changed to trigger the event, so we may as well tell
1232          * him and save an ioctl.
1233          */
1234         __dev_status(md, param);
1235 
1236         table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1237         if (table)
1238                 retrieve_status(table, param, param_size);
1239         dm_put_live_table(md, srcu_idx);
1240 
1241 out:
1242         dm_put(md);
1243 
1244         return r;
1245 }
1246 
1247 /*
1248  * Remember the global event number and make it possible to poll
1249  * for further events.
1250  */
1251 static int dev_arm_poll(struct file *filp, struct dm_ioctl *param, size_t param_size)
1252 {
1253         struct dm_file *priv = filp->private_data;
1254 
1255         priv->global_event_nr = atomic_read(&dm_global_event_nr);
1256 
1257         return 0;
1258 }
1259 
1260 static inline fmode_t get_mode(struct dm_ioctl *param)
1261 {
1262         fmode_t mode = FMODE_READ | FMODE_WRITE;
1263 
1264         if (param->flags & DM_READONLY_FLAG)
1265                 mode = FMODE_READ;
1266 
1267         return mode;
1268 }
1269 
1270 static int next_target(struct dm_target_spec *last, uint32_t next, void *end,
1271                        struct dm_target_spec **spec, char **target_params)
1272 {
1273         *spec = (struct dm_target_spec *) ((unsigned char *) last + next);
1274         *target_params = (char *) (*spec + 1);
1275 
1276         if (*spec < (last + 1))
1277                 return -EINVAL;
1278 
1279         return invalid_str(*target_params, end);
1280 }
1281 
1282 static int populate_table(struct dm_table *table,
1283                           struct dm_ioctl *param, size_t param_size)
1284 {
1285         int r;
1286         unsigned int i = 0;
1287         struct dm_target_spec *spec = (struct dm_target_spec *) param;
1288         uint32_t next = param->data_start;
1289         void *end = (void *) param + param_size;
1290         char *target_params;
1291 
1292         if (!param->target_count) {
1293                 DMWARN("populate_table: no targets specified");
1294                 return -EINVAL;
1295         }
1296 
1297         for (i = 0; i < param->target_count; i++) {
1298 
1299                 r = next_target(spec, next, end, &spec, &target_params);
1300                 if (r) {
1301                         DMWARN("unable to find target");
1302                         return r;
1303                 }
1304 
1305                 r = dm_table_add_target(table, spec->target_type,
1306                                         (sector_t) spec->sector_start,
1307                                         (sector_t) spec->length,
1308                                         target_params);
1309                 if (r) {
1310                         DMWARN("error adding target to table");
1311                         return r;
1312                 }
1313 
1314                 next = spec->next;
1315         }
1316 
1317         return dm_table_complete(table);
1318 }
1319 
1320 static bool is_valid_type(enum dm_queue_mode cur, enum dm_queue_mode new)
1321 {
1322         if (cur == new ||
1323             (cur == DM_TYPE_BIO_BASED && new == DM_TYPE_DAX_BIO_BASED))
1324                 return true;
1325 
1326         return false;
1327 }
1328 
1329 static int table_load(struct file *filp, struct dm_ioctl *param, size_t param_size)
1330 {
1331         int r;
1332         struct hash_cell *hc;
1333         struct dm_table *t, *old_map = NULL;
1334         struct mapped_device *md;
1335         struct target_type *immutable_target_type;
1336 
1337         md = find_device(param);
1338         if (!md)
1339                 return -ENXIO;
1340 
1341         r = dm_table_create(&t, get_mode(param), param->target_count, md);
1342         if (r)
1343                 goto err;
1344 
1345         /* Protect md->type and md->queue against concurrent table loads. */
1346         dm_lock_md_type(md);
1347         r = populate_table(t, param, param_size);
1348         if (r)
1349                 goto err_unlock_md_type;
1350 
1351         immutable_target_type = dm_get_immutable_target_type(md);
1352         if (immutable_target_type &&
1353             (immutable_target_type != dm_table_get_immutable_target_type(t)) &&
1354             !dm_table_get_wildcard_target(t)) {
1355                 DMWARN("can't replace immutable target type %s",
1356                        immutable_target_type->name);
1357                 r = -EINVAL;
1358                 goto err_unlock_md_type;
1359         }
1360 
1361         if (dm_get_md_type(md) == DM_TYPE_NONE) {
1362                 /* Initial table load: acquire type of table. */
1363                 dm_set_md_type(md, dm_table_get_type(t));
1364 
1365                 /* setup md->queue to reflect md's type (may block) */
1366                 r = dm_setup_md_queue(md, t);
1367                 if (r) {
1368                         DMWARN("unable to set up device queue for new table.");
1369                         goto err_unlock_md_type;
1370                 }
1371         } else if (!is_valid_type(dm_get_md_type(md), dm_table_get_type(t))) {
1372                 DMWARN("can't change device type (old=%u vs new=%u) after initial table load.",
1373                        dm_get_md_type(md), dm_table_get_type(t));
1374                 r = -EINVAL;
1375                 goto err_unlock_md_type;
1376         }
1377 
1378         dm_unlock_md_type(md);
1379 
1380         /* stage inactive table */
1381         down_write(&_hash_lock);
1382         hc = dm_get_mdptr(md);
1383         if (!hc || hc->md != md) {
1384                 DMWARN("device has been removed from the dev hash table.");
1385                 up_write(&_hash_lock);
1386                 r = -ENXIO;
1387                 goto err_destroy_table;
1388         }
1389 
1390         if (hc->new_map)
1391                 old_map = hc->new_map;
1392         hc->new_map = t;
1393         up_write(&_hash_lock);
1394 
1395         param->flags |= DM_INACTIVE_PRESENT_FLAG;
1396         __dev_status(md, param);
1397 
1398         if (old_map) {
1399                 dm_sync_table(md);
1400                 dm_table_destroy(old_map);
1401         }
1402 
1403         dm_put(md);
1404 
1405         return 0;
1406 
1407 err_unlock_md_type:
1408         dm_unlock_md_type(md);
1409 err_destroy_table:
1410         dm_table_destroy(t);
1411 err:
1412         dm_put(md);
1413 
1414         return r;
1415 }
1416 
1417 static int table_clear(struct file *filp, struct dm_ioctl *param, size_t param_size)
1418 {
1419         struct hash_cell *hc;
1420         struct mapped_device *md;
1421         struct dm_table *old_map = NULL;
1422 
1423         down_write(&_hash_lock);
1424 
1425         hc = __find_device_hash_cell(param);
1426         if (!hc) {
1427                 DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table.");
1428                 up_write(&_hash_lock);
1429                 return -ENXIO;
1430         }
1431 
1432         if (hc->new_map) {
1433                 old_map = hc->new_map;
1434                 hc->new_map = NULL;
1435         }
1436 
1437         param->flags &= ~DM_INACTIVE_PRESENT_FLAG;
1438 
1439         __dev_status(hc->md, param);
1440         md = hc->md;
1441         up_write(&_hash_lock);
1442         if (old_map) {
1443                 dm_sync_table(md);
1444                 dm_table_destroy(old_map);
1445         }
1446         dm_put(md);
1447 
1448         return 0;
1449 }
1450 
1451 /*
1452  * Retrieves a list of devices used by a particular dm device.
1453  */
1454 static void retrieve_deps(struct dm_table *table,
1455                           struct dm_ioctl *param, size_t param_size)
1456 {
1457         unsigned int count = 0;
1458         struct list_head *tmp;
1459         size_t len, needed;
1460         struct dm_dev_internal *dd;
1461         struct dm_target_deps *deps;
1462 
1463         deps = get_result_buffer(param, param_size, &len);
1464 
1465         /*
1466          * Count the devices.
1467          */
1468         list_for_each (tmp, dm_table_get_devices(table))
1469                 count++;
1470 
1471         /*
1472          * Check we have enough space.
1473          */
1474         needed = sizeof(*deps) + (sizeof(*deps->dev) * count);
1475         if (len < needed) {
1476                 param->flags |= DM_BUFFER_FULL_FLAG;
1477                 return;
1478         }
1479 
1480         /*
1481          * Fill in the devices.
1482          */
1483         deps->count = count;
1484         count = 0;
1485         list_for_each_entry (dd, dm_table_get_devices(table), list)
1486                 deps->dev[count++] = huge_encode_dev(dd->dm_dev->bdev->bd_dev);
1487 
1488         param->data_size = param->data_start + needed;
1489 }
1490 
1491 static int table_deps(struct file *filp, struct dm_ioctl *param, size_t param_size)
1492 {
1493         struct mapped_device *md;
1494         struct dm_table *table;
1495         int srcu_idx;
1496 
1497         md = find_device(param);
1498         if (!md)
1499                 return -ENXIO;
1500 
1501         __dev_status(md, param);
1502 
1503         table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1504         if (table)
1505                 retrieve_deps(table, param, param_size);
1506         dm_put_live_table(md, srcu_idx);
1507 
1508         dm_put(md);
1509 
1510         return 0;
1511 }
1512 
1513 /*
1514  * Return the status of a device as a text string for each
1515  * target.
1516  */
1517 static int table_status(struct file *filp, struct dm_ioctl *param, size_t param_size)
1518 {
1519         struct mapped_device *md;
1520         struct dm_table *table;
1521         int srcu_idx;
1522 
1523         md = find_device(param);
1524         if (!md)
1525                 return -ENXIO;
1526 
1527         __dev_status(md, param);
1528 
1529         table = dm_get_live_or_inactive_table(md, param, &srcu_idx);
1530         if (table)
1531                 retrieve_status(table, param, param_size);
1532         dm_put_live_table(md, srcu_idx);
1533 
1534         dm_put(md);
1535 
1536         return 0;
1537 }
1538 
1539 /*
1540  * Process device-mapper dependent messages.  Messages prefixed with '@'
1541  * are processed by the DM core.  All others are delivered to the target.
1542  * Returns a number <= 1 if message was processed by device mapper.
1543  * Returns 2 if message should be delivered to the target.
1544  */
1545 static int message_for_md(struct mapped_device *md, unsigned argc, char **argv,
1546                           char *result, unsigned maxlen)
1547 {
1548         int r;
1549 
1550         if (**argv != '@')
1551                 return 2; /* no '@' prefix, deliver to target */
1552 
1553         if (!strcasecmp(argv[0], "@cancel_deferred_remove")) {
1554                 if (argc != 1) {
1555                         DMERR("Invalid arguments for @cancel_deferred_remove");
1556                         return -EINVAL;
1557                 }
1558                 return dm_cancel_deferred_remove(md);
1559         }
1560 
1561         r = dm_stats_message(md, argc, argv, result, maxlen);
1562         if (r < 2)
1563                 return r;
1564 
1565         DMERR("Unsupported message sent to DM core: %s", argv[0]);
1566         return -EINVAL;
1567 }
1568 
1569 /*
1570  * Pass a message to the target that's at the supplied device offset.
1571  */
1572 static int target_message(struct file *filp, struct dm_ioctl *param, size_t param_size)
1573 {
1574         int r, argc;
1575         char **argv;
1576         struct mapped_device *md;
1577         struct dm_table *table;
1578         struct dm_target *ti;
1579         struct dm_target_msg *tmsg = (void *) param + param->data_start;
1580         size_t maxlen;
1581         char *result = get_result_buffer(param, param_size, &maxlen);
1582         int srcu_idx;
1583 
1584         md = find_device(param);
1585         if (!md)
1586                 return -ENXIO;
1587 
1588         if (tmsg < (struct dm_target_msg *) param->data ||
1589             invalid_str(tmsg->message, (void *) param + param_size)) {
1590                 DMWARN("Invalid target message parameters.");
1591                 r = -EINVAL;
1592                 goto out;
1593         }
1594 
1595         r = dm_split_args(&argc, &argv, tmsg->message);
1596         if (r) {
1597                 DMWARN("Failed to split target message parameters");
1598                 goto out;
1599         }
1600 
1601         if (!argc) {
1602                 DMWARN("Empty message received.");
1603                 goto out_argv;
1604         }
1605 
1606         r = message_for_md(md, argc, argv, result, maxlen);
1607         if (r <= 1)
1608                 goto out_argv;
1609 
1610         table = dm_get_live_table(md, &srcu_idx);
1611         if (!table)
1612                 goto out_table;
1613 
1614         if (dm_deleting_md(md)) {
1615                 r = -ENXIO;
1616                 goto out_table;
1617         }
1618 
1619         ti = dm_table_find_target(table, tmsg->sector);
1620         if (!ti) {
1621                 DMWARN("Target message sector outside device.");
1622                 r = -EINVAL;
1623         } else if (ti->type->message)
1624                 r = ti->type->message(ti, argc, argv, result, maxlen);
1625         else {
1626                 DMWARN("Target type does not support messages");
1627                 r = -EINVAL;
1628         }
1629 
1630  out_table:
1631         dm_put_live_table(md, srcu_idx);
1632  out_argv:
1633         kfree(argv);
1634  out:
1635         if (r >= 0)
1636                 __dev_status(md, param);
1637 
1638         if (r == 1) {
1639                 param->flags |= DM_DATA_OUT_FLAG;
1640                 if (dm_message_test_buffer_overflow(result, maxlen))
1641                         param->flags |= DM_BUFFER_FULL_FLAG;
1642                 else
1643                         param->data_size = param->data_start + strlen(result) + 1;
1644                 r = 0;
1645         }
1646 
1647         dm_put(md);
1648         return r;
1649 }
1650 
1651 /*
1652  * The ioctl parameter block consists of two parts, a dm_ioctl struct
1653  * followed by a data buffer.  This flag is set if the second part,
1654  * which has a variable size, is not used by the function processing
1655  * the ioctl.
1656  */
1657 #define IOCTL_FLAGS_NO_PARAMS           1
1658 #define IOCTL_FLAGS_ISSUE_GLOBAL_EVENT  2
1659 
1660 /*-----------------------------------------------------------------
1661  * Implementation of open/close/ioctl on the special char
1662  * device.
1663  *---------------------------------------------------------------*/
1664 static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags)
1665 {
1666         static const struct {
1667                 int cmd;
1668                 int flags;
1669                 ioctl_fn fn;
1670         } _ioctls[] = {
1671                 {DM_VERSION_CMD, 0, NULL}, /* version is dealt with elsewhere */
1672                 {DM_REMOVE_ALL_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, remove_all},
1673                 {DM_LIST_DEVICES_CMD, 0, list_devices},
1674 
1675                 {DM_DEV_CREATE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_create},
1676                 {DM_DEV_REMOVE_CMD, IOCTL_FLAGS_NO_PARAMS | IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_remove},
1677                 {DM_DEV_RENAME_CMD, IOCTL_FLAGS_ISSUE_GLOBAL_EVENT, dev_rename},
1678                 {DM_DEV_SUSPEND_CMD, IOCTL_FLAGS_NO_PARAMS, dev_suspend},
1679                 {DM_DEV_STATUS_CMD, IOCTL_FLAGS_NO_PARAMS, dev_status},
1680                 {DM_DEV_WAIT_CMD, 0, dev_wait},
1681 
1682                 {DM_TABLE_LOAD_CMD, 0, table_load},
1683                 {DM_TABLE_CLEAR_CMD, IOCTL_FLAGS_NO_PARAMS, table_clear},
1684                 {DM_TABLE_DEPS_CMD, 0, table_deps},
1685                 {DM_TABLE_STATUS_CMD, 0, table_status},
1686 
1687                 {DM_LIST_VERSIONS_CMD, 0, list_versions},
1688 
1689                 {DM_TARGET_MSG_CMD, 0, target_message},
1690                 {DM_DEV_SET_GEOMETRY_CMD, 0, dev_set_geometry},
1691                 {DM_DEV_ARM_POLL, IOCTL_FLAGS_NO_PARAMS, dev_arm_poll},
1692                 {DM_GET_TARGET_VERSION, 0, get_target_version},
1693         };
1694 
1695         if (unlikely(cmd >= ARRAY_SIZE(_ioctls)))
1696                 return NULL;
1697 
1698         *ioctl_flags = _ioctls[cmd].flags;
1699         return _ioctls[cmd].fn;
1700 }
1701 
1702 /*
1703  * As well as checking the version compatibility this always
1704  * copies the kernel interface version out.
1705  */
1706 static int check_version(unsigned int cmd, struct dm_ioctl __user *user)
1707 {
1708         uint32_t version[3];
1709         int r = 0;
1710 
1711         if (copy_from_user(version, user->version, sizeof(version)))
1712                 return -EFAULT;
1713 
1714         if ((DM_VERSION_MAJOR != version[0]) ||
1715             (DM_VERSION_MINOR < version[1])) {
1716                 DMWARN("ioctl interface mismatch: "
1717                        "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)",
1718                        DM_VERSION_MAJOR, DM_VERSION_MINOR,
1719                        DM_VERSION_PATCHLEVEL,
1720                        version[0], version[1], version[2], cmd);
1721                 r = -EINVAL;
1722         }
1723 
1724         /*
1725          * Fill in the kernel version.
1726          */
1727         version[0] = DM_VERSION_MAJOR;
1728         version[1] = DM_VERSION_MINOR;
1729         version[2] = DM_VERSION_PATCHLEVEL;
1730         if (copy_to_user(user->version, version, sizeof(version)))
1731                 return -EFAULT;
1732 
1733         return r;
1734 }
1735 
1736 #define DM_PARAMS_MALLOC        0x0001  /* Params allocated with kvmalloc() */
1737 #define DM_WIPE_BUFFER          0x0010  /* Wipe input buffer before returning from ioctl */
1738 
1739 static void free_params(struct dm_ioctl *param, size_t param_size, int param_flags)
1740 {
1741         if (param_flags & DM_WIPE_BUFFER)
1742                 memset(param, 0, param_size);
1743 
1744         if (param_flags & DM_PARAMS_MALLOC)
1745                 kvfree(param);
1746 }
1747 
1748 static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kernel,
1749                        int ioctl_flags, struct dm_ioctl **param, int *param_flags)
1750 {
1751         struct dm_ioctl *dmi;
1752         int secure_data;
1753         const size_t minimum_data_size = offsetof(struct dm_ioctl, data);
1754         unsigned noio_flag;
1755 
1756         if (copy_from_user(param_kernel, user, minimum_data_size))
1757                 return -EFAULT;
1758 
1759         if (param_kernel->data_size < minimum_data_size)
1760                 return -EINVAL;
1761 
1762         secure_data = param_kernel->flags & DM_SECURE_DATA_FLAG;
1763 
1764         *param_flags = secure_data ? DM_WIPE_BUFFER : 0;
1765 
1766         if (ioctl_flags & IOCTL_FLAGS_NO_PARAMS) {
1767                 dmi = param_kernel;
1768                 dmi->data_size = minimum_data_size;
1769                 goto data_copied;
1770         }
1771 
1772         /*
1773          * Use __GFP_HIGH to avoid low memory issues when a device is
1774          * suspended and the ioctl is needed to resume it.
1775          * Use kmalloc() rather than vmalloc() when we can.
1776          */
1777         dmi = NULL;
1778         noio_flag = memalloc_noio_save();
1779         dmi = kvmalloc(param_kernel->data_size, GFP_KERNEL | __GFP_HIGH);
1780         memalloc_noio_restore(noio_flag);
1781 
1782         if (!dmi) {
1783                 if (secure_data && clear_user(user, param_kernel->data_size))
1784                         return -EFAULT;
1785                 return -ENOMEM;
1786         }
1787 
1788         *param_flags |= DM_PARAMS_MALLOC;
1789 
1790         /* Copy from param_kernel (which was already copied from user) */
1791         memcpy(dmi, param_kernel, minimum_data_size);
1792 
1793         if (copy_from_user(&dmi->data, (char __user *)user + minimum_data_size,
1794                            param_kernel->data_size - minimum_data_size))
1795                 goto bad;
1796 data_copied:
1797         /* Wipe the user buffer so we do not return it to userspace */
1798         if (secure_data && clear_user(user, param_kernel->data_size))
1799                 goto bad;
1800 
1801         *param = dmi;
1802         return 0;
1803 
1804 bad:
1805         free_params(dmi, param_kernel->data_size, *param_flags);
1806 
1807         return -EFAULT;
1808 }
1809 
1810 static int validate_params(uint cmd, struct dm_ioctl *param)
1811 {
1812         /* Always clear this flag */
1813         param->flags &= ~DM_BUFFER_FULL_FLAG;
1814         param->flags &= ~DM_UEVENT_GENERATED_FLAG;
1815         param->flags &= ~DM_SECURE_DATA_FLAG;
1816         param->flags &= ~DM_DATA_OUT_FLAG;
1817 
1818         /* Ignores parameters */
1819         if (cmd == DM_REMOVE_ALL_CMD ||
1820             cmd == DM_LIST_DEVICES_CMD ||
1821             cmd == DM_LIST_VERSIONS_CMD)
1822                 return 0;
1823 
1824         if (cmd == DM_DEV_CREATE_CMD) {
1825                 if (!*param->name) {
1826                         DMWARN("name not supplied when creating device");
1827                         return -EINVAL;
1828                 }
1829         } else if (*param->uuid && *param->name) {
1830                 DMWARN("only supply one of name or uuid, cmd(%u)", cmd);
1831                 return -EINVAL;
1832         }
1833 
1834         /* Ensure strings are terminated */
1835         param->name[DM_NAME_LEN - 1] = '\0';
1836         param->uuid[DM_UUID_LEN - 1] = '\0';
1837 
1838         return 0;
1839 }
1840 
1841 static int ctl_ioctl(struct file *file, uint command, struct dm_ioctl __user *user)
1842 {
1843         int r = 0;
1844         int ioctl_flags;
1845         int param_flags;
1846         unsigned int cmd;
1847         struct dm_ioctl *uninitialized_var(param);
1848         ioctl_fn fn = NULL;
1849         size_t input_param_size;
1850         struct dm_ioctl param_kernel;
1851 
1852         /* only root can play with this */
1853         if (!capable(CAP_SYS_ADMIN))
1854                 return -EACCES;
1855 
1856         if (_IOC_TYPE(command) != DM_IOCTL)
1857                 return -ENOTTY;
1858 
1859         cmd = _IOC_NR(command);
1860 
1861         /*
1862          * Check the interface version passed in.  This also
1863          * writes out the kernel's interface version.
1864          */
1865         r = check_version(cmd, user);
1866         if (r)
1867                 return r;
1868 
1869         /*
1870          * Nothing more to do for the version command.
1871          */
1872         if (cmd == DM_VERSION_CMD)
1873                 return 0;
1874 
1875         fn = lookup_ioctl(cmd, &ioctl_flags);
1876         if (!fn) {
1877                 DMWARN("dm_ctl_ioctl: unknown command 0x%x", command);
1878                 return -ENOTTY;
1879         }
1880 
1881         /*
1882          * Copy the parameters into kernel space.
1883          */
1884         r = copy_params(user, &param_kernel, ioctl_flags, &param, &param_flags);
1885 
1886         if (r)
1887                 return r;
1888 
1889         input_param_size = param->data_size;
1890         r = validate_params(cmd, param);
1891         if (r)
1892                 goto out;
1893 
1894         param->data_size = offsetof(struct dm_ioctl, data);
1895         r = fn(file, param, input_param_size);
1896 
1897         if (unlikely(param->flags & DM_BUFFER_FULL_FLAG) &&
1898             unlikely(ioctl_flags & IOCTL_FLAGS_NO_PARAMS))
1899                 DMERR("ioctl %d tried to output some data but has IOCTL_FLAGS_NO_PARAMS set", cmd);
1900 
1901         if (!r && ioctl_flags & IOCTL_FLAGS_ISSUE_GLOBAL_EVENT)
1902                 dm_issue_global_event();
1903 
1904         /*
1905          * Copy the results back to userland.
1906          */
1907         if (!r && copy_to_user(user, param, param->data_size))
1908                 r = -EFAULT;
1909 
1910 out:
1911         free_params(param, input_param_size, param_flags);
1912         return r;
1913 }
1914 
1915 static long dm_ctl_ioctl(struct file *file, uint command, ulong u)
1916 {
1917         return (long)ctl_ioctl(file, command, (struct dm_ioctl __user *)u);
1918 }
1919 
1920 #ifdef CONFIG_COMPAT
1921 static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u)
1922 {
1923         return (long)dm_ctl_ioctl(file, command, (ulong) compat_ptr(u));
1924 }
1925 #else
1926 #define dm_compat_ctl_ioctl NULL
1927 #endif
1928 
1929 static int dm_open(struct inode *inode, struct file *filp)
1930 {
1931         int r;
1932         struct dm_file *priv;
1933 
1934         r = nonseekable_open(inode, filp);
1935         if (unlikely(r))
1936                 return r;
1937 
1938         priv = filp->private_data = kmalloc(sizeof(struct dm_file), GFP_KERNEL);
1939         if (!priv)
1940                 return -ENOMEM;
1941 
1942         priv->global_event_nr = atomic_read(&dm_global_event_nr);
1943 
1944         return 0;
1945 }
1946 
1947 static int dm_release(struct inode *inode, struct file *filp)
1948 {
1949         kfree(filp->private_data);
1950         return 0;
1951 }
1952 
1953 static __poll_t dm_poll(struct file *filp, poll_table *wait)
1954 {
1955         struct dm_file *priv = filp->private_data;
1956         __poll_t mask = 0;
1957 
1958         poll_wait(filp, &dm_global_eventq, wait);
1959 
1960         if ((int)(atomic_read(&dm_global_event_nr) - priv->global_event_nr) > 0)
1961                 mask |= EPOLLIN;
1962 
1963         return mask;
1964 }
1965 
1966 static const struct file_operations _ctl_fops = {
1967         .open    = dm_open,
1968         .release = dm_release,
1969         .poll    = dm_poll,
1970         .unlocked_ioctl  = dm_ctl_ioctl,
1971         .compat_ioctl = dm_compat_ctl_ioctl,
1972         .owner   = THIS_MODULE,
1973         .llseek  = noop_llseek,
1974 };
1975 
1976 static struct miscdevice _dm_misc = {
1977         .minor          = MAPPER_CTRL_MINOR,
1978         .name           = DM_NAME,
1979         .nodename       = DM_DIR "/" DM_CONTROL_NODE,
1980         .fops           = &_ctl_fops
1981 };
1982 
1983 MODULE_ALIAS_MISCDEV(MAPPER_CTRL_MINOR);
1984 MODULE_ALIAS("devname:" DM_DIR "/" DM_CONTROL_NODE);
1985 
1986 /*
1987  * Create misc character device and link to DM_DIR/control.
1988  */
1989 int __init dm_interface_init(void)
1990 {
1991         int r;
1992 
1993         r = dm_hash_init();
1994         if (r)
1995                 return r;
1996 
1997         r = misc_register(&_dm_misc);
1998         if (r) {
1999                 DMERR("misc_register failed for control device");
2000                 dm_hash_exit();
2001                 return r;
2002         }
2003 
2004         DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR,
2005                DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA,
2006                DM_DRIVER_EMAIL);
2007         return 0;
2008 }
2009 
2010 void dm_interface_exit(void)
2011 {
2012         misc_deregister(&_dm_misc);
2013         dm_hash_exit();
2014 }
2015 
2016 /**
2017  * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers
2018  * @md: Pointer to mapped_device
2019  * @name: Buffer (size DM_NAME_LEN) for name
2020  * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined
2021  */
2022 int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid)
2023 {
2024         int r = 0;
2025         struct hash_cell *hc;
2026 
2027         if (!md)
2028                 return -ENXIO;
2029 
2030         mutex_lock(&dm_hash_cells_mutex);
2031         hc = dm_get_mdptr(md);
2032         if (!hc || hc->md != md) {
2033                 r = -ENXIO;
2034                 goto out;
2035         }
2036 
2037         if (name)
2038                 strcpy(name, hc->name);
2039         if (uuid)
2040                 strcpy(uuid, hc->uuid ? : "");
2041 
2042 out:
2043         mutex_unlock(&dm_hash_cells_mutex);
2044 
2045         return r;
2046 }
2047 
2048 
2049 /**
2050  * dm_early_create - create a mapped device in early boot.
2051  *
2052  * @dmi: Contains main information of the device mapping to be created.
2053  * @spec_array: array of pointers to struct dm_target_spec. Describes the
2054  * mapping table of the device.
2055  * @target_params_array: array of strings with the parameters to a specific
2056  * target.
2057  *
2058  * Instead of having the struct dm_target_spec and the parameters for every
2059  * target embedded at the end of struct dm_ioctl (as performed in a normal
2060  * ioctl), pass them as arguments, so the caller doesn't need to serialize them.
2061  * The size of the spec_array and target_params_array is given by
2062  * @dmi->target_count.
2063  * This function is supposed to be called in early boot, so locking mechanisms
2064  * to protect against concurrent loads are not required.
2065  */
2066 int __init dm_early_create(struct dm_ioctl *dmi,
2067                            struct dm_target_spec **spec_array,
2068                            char **target_params_array)
2069 {
2070         int r, m = DM_ANY_MINOR;
2071         struct dm_table *t, *old_map;
2072         struct mapped_device *md;
2073         unsigned int i;
2074 
2075         if (!dmi->target_count)
2076                 return -EINVAL;
2077 
2078         r = check_name(dmi->name);
2079         if (r)
2080                 return r;
2081 
2082         if (dmi->flags & DM_PERSISTENT_DEV_FLAG)
2083                 m = MINOR(huge_decode_dev(dmi->dev));
2084 
2085         /* alloc dm device */
2086         r = dm_create(m, &md);
2087         if (r)
2088                 return r;
2089 
2090         /* hash insert */
2091         r = dm_hash_insert(dmi->name, *dmi->uuid ? dmi->uuid : NULL, md);
2092         if (r)
2093                 goto err_destroy_dm;
2094 
2095         /* alloc table */
2096         r = dm_table_create(&t, get_mode(dmi), dmi->target_count, md);
2097         if (r)
2098                 goto err_hash_remove;
2099 
2100         /* add targets */
2101         for (i = 0; i < dmi->target_count; i++) {
2102                 r = dm_table_add_target(t, spec_array[i]->target_type,
2103                                         (sector_t) spec_array[i]->sector_start,
2104                                         (sector_t) spec_array[i]->length,
2105                                         target_params_array[i]);
2106                 if (r) {
2107                         DMWARN("error adding target to table");
2108                         goto err_destroy_table;
2109                 }
2110         }
2111 
2112         /* finish table */
2113         r = dm_table_complete(t);
2114         if (r)
2115                 goto err_destroy_table;
2116 
2117         md->type = dm_table_get_type(t);
2118         /* setup md->queue to reflect md's type (may block) */
2119         r = dm_setup_md_queue(md, t);
2120         if (r) {
2121                 DMWARN("unable to set up device queue for new table.");
2122                 goto err_destroy_table;
2123         }
2124 
2125         /* Set new map */
2126         dm_suspend(md, 0);
2127         old_map = dm_swap_table(md, t);
2128         if (IS_ERR(old_map)) {
2129                 r = PTR_ERR(old_map);
2130                 goto err_destroy_table;
2131         }
2132         set_disk_ro(dm_disk(md), !!(dmi->flags & DM_READONLY_FLAG));
2133 
2134         /* resume device */
2135         r = dm_resume(md);
2136         if (r)
2137                 goto err_destroy_table;
2138 
2139         DMINFO("%s (%s) is ready", md->disk->disk_name, dmi->name);
2140         dm_put(md);
2141         return 0;
2142 
2143 err_destroy_table:
2144         dm_table_destroy(t);
2145 err_hash_remove:
2146         (void) __hash_remove(__get_name_cell(dmi->name));
2147         /* release reference from __get_name_cell */
2148         dm_put(md);
2149 err_destroy_dm:
2150         dm_put(md);
2151         dm_destroy(md);
2152         return r;
2153 }
/* [<][>][^][v][top][bottom][index][help] */
root/drivers/md/dm-ioctl.c

DEFINITIONS
