Kyle Swenson | 8d8f654 | 2021-03-15 11:02:55 -0600 | [diff] [blame] | 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 | /* |
| 40 | * A dummy definition to make RCU happy. |
| 41 | * struct dm_table should never be dereferenced in this file. |
| 42 | */ |
| 43 | struct dm_table { |
| 44 | int undefined__; |
| 45 | }; |
| 46 | |
| 47 | struct vers_iter { |
| 48 | size_t param_size; |
| 49 | struct dm_target_versions *vers, *old_vers; |
| 50 | char *end; |
| 51 | uint32_t flags; |
| 52 | }; |
| 53 | |
| 54 | |
| 55 | #define NUM_BUCKETS 64 |
| 56 | #define MASK_BUCKETS (NUM_BUCKETS - 1) |
| 57 | static struct list_head _name_buckets[NUM_BUCKETS]; |
| 58 | static struct list_head _uuid_buckets[NUM_BUCKETS]; |
| 59 | |
| 60 | static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred); |
| 61 | |
| 62 | /* |
| 63 | * Guards access to both hash tables. |
| 64 | */ |
| 65 | static DECLARE_RWSEM(_hash_lock); |
| 66 | |
| 67 | /* |
| 68 | * Protects use of mdptr to obtain hash cell name and uuid from mapped device. |
| 69 | */ |
| 70 | static DEFINE_MUTEX(dm_hash_cells_mutex); |
| 71 | |
| 72 | static void init_buckets(struct list_head *buckets) |
| 73 | { |
| 74 | unsigned int i; |
| 75 | |
| 76 | for (i = 0; i < NUM_BUCKETS; i++) |
| 77 | INIT_LIST_HEAD(buckets + i); |
| 78 | } |
| 79 | |
| 80 | static int dm_hash_init(void) |
| 81 | { |
| 82 | init_buckets(_name_buckets); |
| 83 | init_buckets(_uuid_buckets); |
| 84 | return 0; |
| 85 | } |
| 86 | |
| 87 | static void dm_hash_exit(void) |
| 88 | { |
| 89 | dm_hash_remove_all(false, false, false); |
| 90 | } |
| 91 | |
| 92 | /*----------------------------------------------------------------- |
| 93 | * Hash function: |
| 94 | * We're not really concerned with the str hash function being |
| 95 | * fast since it's only used by the ioctl interface. |
| 96 | *---------------------------------------------------------------*/ |
| 97 | static unsigned int hash_str(const char *str) |
| 98 | { |
| 99 | const unsigned int hash_mult = 2654435387U; |
| 100 | unsigned int h = 0; |
| 101 | |
| 102 | while (*str) |
| 103 | h = (h + (unsigned int) *str++) * hash_mult; |
| 104 | |
| 105 | return h & MASK_BUCKETS; |
| 106 | } |
| 107 | |
| 108 | /*----------------------------------------------------------------- |
| 109 | * Code for looking up a device by name |
| 110 | *---------------------------------------------------------------*/ |
| 111 | static struct hash_cell *__get_name_cell(const char *str) |
| 112 | { |
| 113 | struct hash_cell *hc; |
| 114 | unsigned int h = hash_str(str); |
| 115 | |
| 116 | list_for_each_entry (hc, _name_buckets + h, name_list) |
| 117 | if (!strcmp(hc->name, str)) { |
| 118 | dm_get(hc->md); |
| 119 | return hc; |
| 120 | } |
| 121 | |
| 122 | return NULL; |
| 123 | } |
| 124 | |
| 125 | static struct hash_cell *__get_uuid_cell(const char *str) |
| 126 | { |
| 127 | struct hash_cell *hc; |
| 128 | unsigned int h = hash_str(str); |
| 129 | |
| 130 | list_for_each_entry (hc, _uuid_buckets + h, uuid_list) |
| 131 | if (!strcmp(hc->uuid, str)) { |
| 132 | dm_get(hc->md); |
| 133 | return hc; |
| 134 | } |
| 135 | |
| 136 | return NULL; |
| 137 | } |
| 138 | |
| 139 | static struct hash_cell *__get_dev_cell(uint64_t dev) |
| 140 | { |
| 141 | struct mapped_device *md; |
| 142 | struct hash_cell *hc; |
| 143 | |
| 144 | md = dm_get_md(huge_decode_dev(dev)); |
| 145 | if (!md) |
| 146 | return NULL; |
| 147 | |
| 148 | hc = dm_get_mdptr(md); |
| 149 | if (!hc) { |
| 150 | dm_put(md); |
| 151 | return NULL; |
| 152 | } |
| 153 | |
| 154 | return hc; |
| 155 | } |
| 156 | |
| 157 | /*----------------------------------------------------------------- |
| 158 | * Inserting, removing and renaming a device. |
| 159 | *---------------------------------------------------------------*/ |
| 160 | static struct hash_cell *alloc_cell(const char *name, const char *uuid, |
| 161 | struct mapped_device *md) |
| 162 | { |
| 163 | struct hash_cell *hc; |
| 164 | |
| 165 | hc = kmalloc(sizeof(*hc), GFP_KERNEL); |
| 166 | if (!hc) |
| 167 | return NULL; |
| 168 | |
| 169 | hc->name = kstrdup(name, GFP_KERNEL); |
| 170 | if (!hc->name) { |
| 171 | kfree(hc); |
| 172 | return NULL; |
| 173 | } |
| 174 | |
| 175 | if (!uuid) |
| 176 | hc->uuid = NULL; |
| 177 | |
| 178 | else { |
| 179 | hc->uuid = kstrdup(uuid, GFP_KERNEL); |
| 180 | if (!hc->uuid) { |
| 181 | kfree(hc->name); |
| 182 | kfree(hc); |
| 183 | return NULL; |
| 184 | } |
| 185 | } |
| 186 | |
| 187 | INIT_LIST_HEAD(&hc->name_list); |
| 188 | INIT_LIST_HEAD(&hc->uuid_list); |
| 189 | hc->md = md; |
| 190 | hc->new_map = NULL; |
| 191 | return hc; |
| 192 | } |
| 193 | |
| 194 | static void free_cell(struct hash_cell *hc) |
| 195 | { |
| 196 | if (hc) { |
| 197 | kfree(hc->name); |
| 198 | kfree(hc->uuid); |
| 199 | kfree(hc); |
| 200 | } |
| 201 | } |
| 202 | |
| 203 | /* |
| 204 | * The kdev_t and uuid of a device can never change once it is |
| 205 | * initially inserted. |
| 206 | */ |
| 207 | static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md) |
| 208 | { |
| 209 | struct hash_cell *cell, *hc; |
| 210 | |
| 211 | /* |
| 212 | * Allocate the new cells. |
| 213 | */ |
| 214 | cell = alloc_cell(name, uuid, md); |
| 215 | if (!cell) |
| 216 | return -ENOMEM; |
| 217 | |
| 218 | /* |
| 219 | * Insert the cell into both hash tables. |
| 220 | */ |
| 221 | down_write(&_hash_lock); |
| 222 | hc = __get_name_cell(name); |
| 223 | if (hc) { |
| 224 | dm_put(hc->md); |
| 225 | goto bad; |
| 226 | } |
| 227 | |
| 228 | list_add(&cell->name_list, _name_buckets + hash_str(name)); |
| 229 | |
| 230 | if (uuid) { |
| 231 | hc = __get_uuid_cell(uuid); |
| 232 | if (hc) { |
| 233 | list_del(&cell->name_list); |
| 234 | dm_put(hc->md); |
| 235 | goto bad; |
| 236 | } |
| 237 | list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid)); |
| 238 | } |
| 239 | dm_get(md); |
| 240 | mutex_lock(&dm_hash_cells_mutex); |
| 241 | dm_set_mdptr(md, cell); |
| 242 | mutex_unlock(&dm_hash_cells_mutex); |
| 243 | up_write(&_hash_lock); |
| 244 | |
| 245 | return 0; |
| 246 | |
| 247 | bad: |
| 248 | up_write(&_hash_lock); |
| 249 | free_cell(cell); |
| 250 | return -EBUSY; |
| 251 | } |
| 252 | |
| 253 | static struct dm_table *__hash_remove(struct hash_cell *hc) |
| 254 | { |
| 255 | struct dm_table *table; |
| 256 | int srcu_idx; |
| 257 | |
| 258 | /* remove from the dev hash */ |
| 259 | list_del(&hc->uuid_list); |
| 260 | list_del(&hc->name_list); |
| 261 | mutex_lock(&dm_hash_cells_mutex); |
| 262 | dm_set_mdptr(hc->md, NULL); |
| 263 | mutex_unlock(&dm_hash_cells_mutex); |
| 264 | |
| 265 | table = dm_get_live_table(hc->md, &srcu_idx); |
| 266 | if (table) |
| 267 | dm_table_event(table); |
| 268 | dm_put_live_table(hc->md, srcu_idx); |
| 269 | |
| 270 | table = NULL; |
| 271 | if (hc->new_map) |
| 272 | table = hc->new_map; |
| 273 | dm_put(hc->md); |
| 274 | free_cell(hc); |
| 275 | |
| 276 | return table; |
| 277 | } |
| 278 | |
| 279 | static void dm_hash_remove_all(bool keep_open_devices, bool mark_deferred, bool only_deferred) |
| 280 | { |
| 281 | int i, dev_skipped; |
| 282 | struct hash_cell *hc; |
| 283 | struct mapped_device *md; |
| 284 | struct dm_table *t; |
| 285 | |
| 286 | retry: |
| 287 | dev_skipped = 0; |
| 288 | |
| 289 | down_write(&_hash_lock); |
| 290 | |
| 291 | for (i = 0; i < NUM_BUCKETS; i++) { |
| 292 | list_for_each_entry(hc, _name_buckets + i, name_list) { |
| 293 | md = hc->md; |
| 294 | dm_get(md); |
| 295 | |
| 296 | if (keep_open_devices && |
| 297 | dm_lock_for_deletion(md, mark_deferred, only_deferred)) { |
| 298 | dm_put(md); |
| 299 | dev_skipped++; |
| 300 | continue; |
| 301 | } |
| 302 | |
| 303 | t = __hash_remove(hc); |
| 304 | |
| 305 | up_write(&_hash_lock); |
| 306 | |
| 307 | if (t) { |
| 308 | dm_sync_table(md); |
| 309 | dm_table_destroy(t); |
| 310 | } |
| 311 | dm_put(md); |
| 312 | if (likely(keep_open_devices)) |
| 313 | dm_destroy(md); |
| 314 | else |
| 315 | dm_destroy_immediate(md); |
| 316 | |
| 317 | /* |
| 318 | * Some mapped devices may be using other mapped |
| 319 | * devices, so repeat until we make no further |
| 320 | * progress. If a new mapped device is created |
| 321 | * here it will also get removed. |
| 322 | */ |
| 323 | goto retry; |
| 324 | } |
| 325 | } |
| 326 | |
| 327 | up_write(&_hash_lock); |
| 328 | |
| 329 | if (dev_skipped) |
| 330 | DMWARN("remove_all left %d open device(s)", dev_skipped); |
| 331 | } |
| 332 | |
| 333 | /* |
| 334 | * Set the uuid of a hash_cell that isn't already set. |
| 335 | */ |
| 336 | static void __set_cell_uuid(struct hash_cell *hc, char *new_uuid) |
| 337 | { |
| 338 | mutex_lock(&dm_hash_cells_mutex); |
| 339 | hc->uuid = new_uuid; |
| 340 | mutex_unlock(&dm_hash_cells_mutex); |
| 341 | |
| 342 | list_add(&hc->uuid_list, _uuid_buckets + hash_str(new_uuid)); |
| 343 | } |
| 344 | |
| 345 | /* |
| 346 | * Changes the name of a hash_cell and returns the old name for |
| 347 | * the caller to free. |
| 348 | */ |
| 349 | static char *__change_cell_name(struct hash_cell *hc, char *new_name) |
| 350 | { |
| 351 | char *old_name; |
| 352 | |
| 353 | /* |
| 354 | * Rename and move the name cell. |
| 355 | */ |
| 356 | list_del(&hc->name_list); |
| 357 | old_name = hc->name; |
| 358 | |
| 359 | mutex_lock(&dm_hash_cells_mutex); |
| 360 | hc->name = new_name; |
| 361 | mutex_unlock(&dm_hash_cells_mutex); |
| 362 | |
| 363 | list_add(&hc->name_list, _name_buckets + hash_str(new_name)); |
| 364 | |
| 365 | return old_name; |
| 366 | } |
| 367 | |
| 368 | static struct mapped_device *dm_hash_rename(struct dm_ioctl *param, |
| 369 | const char *new) |
| 370 | { |
| 371 | char *new_data, *old_name = NULL; |
| 372 | struct hash_cell *hc; |
| 373 | struct dm_table *table; |
| 374 | struct mapped_device *md; |
| 375 | unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0; |
| 376 | int srcu_idx; |
| 377 | |
| 378 | /* |
| 379 | * duplicate new. |
| 380 | */ |
| 381 | new_data = kstrdup(new, GFP_KERNEL); |
| 382 | if (!new_data) |
| 383 | return ERR_PTR(-ENOMEM); |
| 384 | |
| 385 | down_write(&_hash_lock); |
| 386 | |
| 387 | /* |
| 388 | * Is new free ? |
| 389 | */ |
| 390 | if (change_uuid) |
| 391 | hc = __get_uuid_cell(new); |
| 392 | else |
| 393 | hc = __get_name_cell(new); |
| 394 | |
| 395 | if (hc) { |
| 396 | DMWARN("Unable to change %s on mapped device %s to one that " |
| 397 | "already exists: %s", |
| 398 | change_uuid ? "uuid" : "name", |
| 399 | param->name, new); |
| 400 | dm_put(hc->md); |
| 401 | up_write(&_hash_lock); |
| 402 | kfree(new_data); |
| 403 | return ERR_PTR(-EBUSY); |
| 404 | } |
| 405 | |
| 406 | /* |
| 407 | * Is there such a device as 'old' ? |
| 408 | */ |
| 409 | hc = __get_name_cell(param->name); |
| 410 | if (!hc) { |
| 411 | DMWARN("Unable to rename non-existent device, %s to %s%s", |
| 412 | param->name, change_uuid ? "uuid " : "", new); |
| 413 | up_write(&_hash_lock); |
| 414 | kfree(new_data); |
| 415 | return ERR_PTR(-ENXIO); |
| 416 | } |
| 417 | |
| 418 | /* |
| 419 | * Does this device already have a uuid? |
| 420 | */ |
| 421 | if (change_uuid && hc->uuid) { |
| 422 | DMWARN("Unable to change uuid of mapped device %s to %s " |
| 423 | "because uuid is already set to %s", |
| 424 | param->name, new, hc->uuid); |
| 425 | dm_put(hc->md); |
| 426 | up_write(&_hash_lock); |
| 427 | kfree(new_data); |
| 428 | return ERR_PTR(-EINVAL); |
| 429 | } |
| 430 | |
| 431 | if (change_uuid) |
| 432 | __set_cell_uuid(hc, new_data); |
| 433 | else |
| 434 | old_name = __change_cell_name(hc, new_data); |
| 435 | |
| 436 | /* |
| 437 | * Wake up any dm event waiters. |
| 438 | */ |
| 439 | table = dm_get_live_table(hc->md, &srcu_idx); |
| 440 | if (table) |
| 441 | dm_table_event(table); |
| 442 | dm_put_live_table(hc->md, srcu_idx); |
| 443 | |
| 444 | if (!dm_kobject_uevent(hc->md, KOBJ_CHANGE, param->event_nr)) |
| 445 | param->flags |= DM_UEVENT_GENERATED_FLAG; |
| 446 | |
| 447 | md = hc->md; |
| 448 | up_write(&_hash_lock); |
| 449 | kfree(old_name); |
| 450 | |
| 451 | return md; |
| 452 | } |
| 453 | |
| 454 | void dm_deferred_remove(void) |
| 455 | { |
| 456 | dm_hash_remove_all(true, false, true); |
| 457 | } |
| 458 | |
| 459 | /*----------------------------------------------------------------- |
| 460 | * Implementation of the ioctl commands |
| 461 | *---------------------------------------------------------------*/ |
| 462 | /* |
| 463 | * All the ioctl commands get dispatched to functions with this |
| 464 | * prototype. |
| 465 | */ |
| 466 | typedef int (*ioctl_fn)(struct dm_ioctl *param, size_t param_size); |
| 467 | |
| 468 | static int remove_all(struct dm_ioctl *param, size_t param_size) |
| 469 | { |
| 470 | dm_hash_remove_all(true, !!(param->flags & DM_DEFERRED_REMOVE), false); |
| 471 | param->data_size = 0; |
| 472 | return 0; |
| 473 | } |
| 474 | |
| 475 | /* |
| 476 | * Round up the ptr to an 8-byte boundary. |
| 477 | */ |
| 478 | #define ALIGN_MASK 7 |
| 479 | static inline void *align_ptr(void *ptr) |
| 480 | { |
| 481 | return (void *) (((size_t) (ptr + ALIGN_MASK)) & ~ALIGN_MASK); |
| 482 | } |
| 483 | |
| 484 | /* |
| 485 | * Retrieves the data payload buffer from an already allocated |
| 486 | * struct dm_ioctl. |
| 487 | */ |
| 488 | static void *get_result_buffer(struct dm_ioctl *param, size_t param_size, |
| 489 | size_t *len) |
| 490 | { |
| 491 | param->data_start = align_ptr(param + 1) - (void *) param; |
| 492 | |
| 493 | if (param->data_start < param_size) |
| 494 | *len = param_size - param->data_start; |
| 495 | else |
| 496 | *len = 0; |
| 497 | |
| 498 | return ((void *) param) + param->data_start; |
| 499 | } |
| 500 | |
| 501 | static int list_devices(struct dm_ioctl *param, size_t param_size) |
| 502 | { |
| 503 | unsigned int i; |
| 504 | struct hash_cell *hc; |
| 505 | size_t len, needed = 0; |
| 506 | struct gendisk *disk; |
| 507 | struct dm_name_list *nl, *old_nl = NULL; |
| 508 | |
| 509 | down_write(&_hash_lock); |
| 510 | |
| 511 | /* |
| 512 | * Loop through all the devices working out how much |
| 513 | * space we need. |
| 514 | */ |
| 515 | for (i = 0; i < NUM_BUCKETS; i++) { |
| 516 | list_for_each_entry (hc, _name_buckets + i, name_list) { |
| 517 | needed += sizeof(struct dm_name_list); |
| 518 | needed += strlen(hc->name) + 1; |
| 519 | needed += ALIGN_MASK; |
| 520 | } |
| 521 | } |
| 522 | |
| 523 | /* |
| 524 | * Grab our output buffer. |
| 525 | */ |
| 526 | nl = get_result_buffer(param, param_size, &len); |
| 527 | if (len < needed) { |
| 528 | param->flags |= DM_BUFFER_FULL_FLAG; |
| 529 | goto out; |
| 530 | } |
| 531 | param->data_size = param->data_start + needed; |
| 532 | |
| 533 | nl->dev = 0; /* Flags no data */ |
| 534 | |
| 535 | /* |
| 536 | * Now loop through filling out the names. |
| 537 | */ |
| 538 | for (i = 0; i < NUM_BUCKETS; i++) { |
| 539 | list_for_each_entry (hc, _name_buckets + i, name_list) { |
| 540 | if (old_nl) |
| 541 | old_nl->next = (uint32_t) ((void *) nl - |
| 542 | (void *) old_nl); |
| 543 | disk = dm_disk(hc->md); |
| 544 | nl->dev = huge_encode_dev(disk_devt(disk)); |
| 545 | nl->next = 0; |
| 546 | strcpy(nl->name, hc->name); |
| 547 | |
| 548 | old_nl = nl; |
| 549 | nl = align_ptr(((void *) ++nl) + strlen(hc->name) + 1); |
| 550 | } |
| 551 | } |
| 552 | |
| 553 | out: |
| 554 | up_write(&_hash_lock); |
| 555 | return 0; |
| 556 | } |
| 557 | |
| 558 | static void list_version_get_needed(struct target_type *tt, void *needed_param) |
| 559 | { |
| 560 | size_t *needed = needed_param; |
| 561 | |
| 562 | *needed += sizeof(struct dm_target_versions); |
| 563 | *needed += strlen(tt->name); |
| 564 | *needed += ALIGN_MASK; |
| 565 | } |
| 566 | |
| 567 | static void list_version_get_info(struct target_type *tt, void *param) |
| 568 | { |
| 569 | struct vers_iter *info = param; |
| 570 | |
| 571 | /* Check space - it might have changed since the first iteration */ |
| 572 | if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 > |
| 573 | info->end) { |
| 574 | |
| 575 | info->flags = DM_BUFFER_FULL_FLAG; |
| 576 | return; |
| 577 | } |
| 578 | |
| 579 | if (info->old_vers) |
| 580 | info->old_vers->next = (uint32_t) ((void *)info->vers - |
| 581 | (void *)info->old_vers); |
| 582 | info->vers->version[0] = tt->version[0]; |
| 583 | info->vers->version[1] = tt->version[1]; |
| 584 | info->vers->version[2] = tt->version[2]; |
| 585 | info->vers->next = 0; |
| 586 | strcpy(info->vers->name, tt->name); |
| 587 | |
| 588 | info->old_vers = info->vers; |
| 589 | info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1); |
| 590 | } |
| 591 | |
| 592 | static int list_versions(struct dm_ioctl *param, size_t param_size) |
| 593 | { |
| 594 | size_t len, needed = 0; |
| 595 | struct dm_target_versions *vers; |
| 596 | struct vers_iter iter_info; |
| 597 | |
| 598 | /* |
| 599 | * Loop through all the devices working out how much |
| 600 | * space we need. |
| 601 | */ |
| 602 | dm_target_iterate(list_version_get_needed, &needed); |
| 603 | |
| 604 | /* |
| 605 | * Grab our output buffer. |
| 606 | */ |
| 607 | vers = get_result_buffer(param, param_size, &len); |
| 608 | if (len < needed) { |
| 609 | param->flags |= DM_BUFFER_FULL_FLAG; |
| 610 | goto out; |
| 611 | } |
| 612 | param->data_size = param->data_start + needed; |
| 613 | |
| 614 | iter_info.param_size = param_size; |
| 615 | iter_info.old_vers = NULL; |
| 616 | iter_info.vers = vers; |
| 617 | iter_info.flags = 0; |
| 618 | iter_info.end = (char *)vers+len; |
| 619 | |
| 620 | /* |
| 621 | * Now loop through filling out the names & versions. |
| 622 | */ |
| 623 | dm_target_iterate(list_version_get_info, &iter_info); |
| 624 | param->flags |= iter_info.flags; |
| 625 | |
| 626 | out: |
| 627 | return 0; |
| 628 | } |
| 629 | |
| 630 | static int check_name(const char *name) |
| 631 | { |
| 632 | if (strchr(name, '/')) { |
| 633 | DMWARN("invalid device name"); |
| 634 | return -EINVAL; |
| 635 | } |
| 636 | |
| 637 | return 0; |
| 638 | } |
| 639 | |
| 640 | /* |
| 641 | * On successful return, the caller must not attempt to acquire |
| 642 | * _hash_lock without first calling dm_put_live_table, because dm_table_destroy |
| 643 | * waits for this dm_put_live_table and could be called under this lock. |
| 644 | */ |
| 645 | static struct dm_table *dm_get_inactive_table(struct mapped_device *md, int *srcu_idx) |
| 646 | { |
| 647 | struct hash_cell *hc; |
| 648 | struct dm_table *table = NULL; |
| 649 | |
| 650 | /* increment rcu count, we don't care about the table pointer */ |
| 651 | dm_get_live_table(md, srcu_idx); |
| 652 | |
| 653 | down_read(&_hash_lock); |
| 654 | hc = dm_get_mdptr(md); |
| 655 | if (!hc || hc->md != md) { |
| 656 | DMWARN("device has been removed from the dev hash table."); |
| 657 | goto out; |
| 658 | } |
| 659 | |
| 660 | table = hc->new_map; |
| 661 | |
| 662 | out: |
| 663 | up_read(&_hash_lock); |
| 664 | |
| 665 | return table; |
| 666 | } |
| 667 | |
| 668 | static struct dm_table *dm_get_live_or_inactive_table(struct mapped_device *md, |
| 669 | struct dm_ioctl *param, |
| 670 | int *srcu_idx) |
| 671 | { |
| 672 | return (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) ? |
| 673 | dm_get_inactive_table(md, srcu_idx) : dm_get_live_table(md, srcu_idx); |
| 674 | } |
| 675 | |
| 676 | /* |
| 677 | * Fills in a dm_ioctl structure, ready for sending back to |
| 678 | * userland. |
| 679 | */ |
| 680 | static void __dev_status(struct mapped_device *md, struct dm_ioctl *param) |
| 681 | { |
| 682 | struct gendisk *disk = dm_disk(md); |
| 683 | struct dm_table *table; |
| 684 | int srcu_idx; |
| 685 | |
| 686 | param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG | |
| 687 | DM_ACTIVE_PRESENT_FLAG | DM_INTERNAL_SUSPEND_FLAG); |
| 688 | |
| 689 | if (dm_suspended_md(md)) |
| 690 | param->flags |= DM_SUSPEND_FLAG; |
| 691 | |
| 692 | if (dm_suspended_internally_md(md)) |
| 693 | param->flags |= DM_INTERNAL_SUSPEND_FLAG; |
| 694 | |
| 695 | if (dm_test_deferred_remove_flag(md)) |
| 696 | param->flags |= DM_DEFERRED_REMOVE; |
| 697 | |
| 698 | param->dev = huge_encode_dev(disk_devt(disk)); |
| 699 | |
| 700 | /* |
| 701 | * Yes, this will be out of date by the time it gets back |
| 702 | * to userland, but it is still very useful for |
| 703 | * debugging. |
| 704 | */ |
| 705 | param->open_count = dm_open_count(md); |
| 706 | |
| 707 | param->event_nr = dm_get_event_nr(md); |
| 708 | param->target_count = 0; |
| 709 | |
| 710 | table = dm_get_live_table(md, &srcu_idx); |
| 711 | if (table) { |
| 712 | if (!(param->flags & DM_QUERY_INACTIVE_TABLE_FLAG)) { |
| 713 | if (get_disk_ro(disk)) |
| 714 | param->flags |= DM_READONLY_FLAG; |
| 715 | param->target_count = dm_table_get_num_targets(table); |
| 716 | } |
| 717 | |
| 718 | param->flags |= DM_ACTIVE_PRESENT_FLAG; |
| 719 | } |
| 720 | dm_put_live_table(md, srcu_idx); |
| 721 | |
| 722 | if (param->flags & DM_QUERY_INACTIVE_TABLE_FLAG) { |
| 723 | int srcu_idx; |
| 724 | table = dm_get_inactive_table(md, &srcu_idx); |
| 725 | if (table) { |
| 726 | if (!(dm_table_get_mode(table) & FMODE_WRITE)) |
| 727 | param->flags |= DM_READONLY_FLAG; |
| 728 | param->target_count = dm_table_get_num_targets(table); |
| 729 | } |
| 730 | dm_put_live_table(md, srcu_idx); |
| 731 | } |
| 732 | } |
| 733 | |
| 734 | static int dev_create(struct dm_ioctl *param, size_t param_size) |
| 735 | { |
| 736 | int r, m = DM_ANY_MINOR; |
| 737 | struct mapped_device *md; |
| 738 | |
| 739 | r = check_name(param->name); |
| 740 | if (r) |
| 741 | return r; |
| 742 | |
| 743 | if (param->flags & DM_PERSISTENT_DEV_FLAG) |
| 744 | m = MINOR(huge_decode_dev(param->dev)); |
| 745 | |
| 746 | r = dm_create(m, &md); |
| 747 | if (r) |
| 748 | return r; |
| 749 | |
| 750 | r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md); |
| 751 | if (r) { |
| 752 | dm_put(md); |
| 753 | dm_destroy(md); |
| 754 | return r; |
| 755 | } |
| 756 | |
| 757 | param->flags &= ~DM_INACTIVE_PRESENT_FLAG; |
| 758 | |
| 759 | __dev_status(md, param); |
| 760 | |
| 761 | dm_put(md); |
| 762 | |
| 763 | return 0; |
| 764 | } |
| 765 | |
| 766 | /* |
| 767 | * Always use UUID for lookups if it's present, otherwise use name or dev. |
| 768 | */ |
| 769 | static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param) |
| 770 | { |
| 771 | struct hash_cell *hc = NULL; |
| 772 | |
| 773 | if (*param->uuid) { |
| 774 | if (*param->name || param->dev) |
| 775 | return NULL; |
| 776 | |
| 777 | hc = __get_uuid_cell(param->uuid); |
| 778 | if (!hc) |
| 779 | return NULL; |
| 780 | } else if (*param->name) { |
| 781 | if (param->dev) |
| 782 | return NULL; |
| 783 | |
| 784 | hc = __get_name_cell(param->name); |
| 785 | if (!hc) |
| 786 | return NULL; |
| 787 | } else if (param->dev) { |
| 788 | hc = __get_dev_cell(param->dev); |
| 789 | if (!hc) |
| 790 | return NULL; |
| 791 | } else |
| 792 | return NULL; |
| 793 | |
| 794 | /* |
| 795 | * Sneakily write in both the name and the uuid |
| 796 | * while we have the cell. |
| 797 | */ |
| 798 | strlcpy(param->name, hc->name, sizeof(param->name)); |
| 799 | if (hc->uuid) |
| 800 | strlcpy(param->uuid, hc->uuid, sizeof(param->uuid)); |
| 801 | else |
| 802 | param->uuid[0] = '\0'; |
| 803 | |
| 804 | if (hc->new_map) |
| 805 | param->flags |= DM_INACTIVE_PRESENT_FLAG; |
| 806 | else |
| 807 | param->flags &= ~DM_INACTIVE_PRESENT_FLAG; |
| 808 | |
| 809 | return hc; |
| 810 | } |
| 811 | |
| 812 | static struct mapped_device *find_device(struct dm_ioctl *param) |
| 813 | { |
| 814 | struct hash_cell *hc; |
| 815 | struct mapped_device *md = NULL; |
| 816 | |
| 817 | down_read(&_hash_lock); |
| 818 | hc = __find_device_hash_cell(param); |
| 819 | if (hc) |
| 820 | md = hc->md; |
| 821 | up_read(&_hash_lock); |
| 822 | |
| 823 | return md; |
| 824 | } |
| 825 | |
| 826 | static int dev_remove(struct dm_ioctl *param, size_t param_size) |
| 827 | { |
| 828 | struct hash_cell *hc; |
| 829 | struct mapped_device *md; |
| 830 | int r; |
| 831 | struct dm_table *t; |
| 832 | |
| 833 | down_write(&_hash_lock); |
| 834 | hc = __find_device_hash_cell(param); |
| 835 | |
| 836 | if (!hc) { |
| 837 | DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table."); |
| 838 | up_write(&_hash_lock); |
| 839 | return -ENXIO; |
| 840 | } |
| 841 | |
| 842 | md = hc->md; |
| 843 | |
| 844 | /* |
| 845 | * Ensure the device is not open and nothing further can open it. |
| 846 | */ |
| 847 | r = dm_lock_for_deletion(md, !!(param->flags & DM_DEFERRED_REMOVE), false); |
| 848 | if (r) { |
| 849 | if (r == -EBUSY && param->flags & DM_DEFERRED_REMOVE) { |
| 850 | up_write(&_hash_lock); |
| 851 | dm_put(md); |
| 852 | return 0; |
| 853 | } |
| 854 | DMDEBUG_LIMIT("unable to remove open device %s", hc->name); |
| 855 | up_write(&_hash_lock); |
| 856 | dm_put(md); |
| 857 | return r; |
| 858 | } |
| 859 | |
| 860 | t = __hash_remove(hc); |
| 861 | up_write(&_hash_lock); |
| 862 | |
| 863 | if (t) { |
| 864 | dm_sync_table(md); |
| 865 | dm_table_destroy(t); |
| 866 | } |
| 867 | |
| 868 | param->flags &= ~DM_DEFERRED_REMOVE; |
| 869 | |
| 870 | if (!dm_kobject_uevent(md, KOBJ_REMOVE, param->event_nr)) |
| 871 | param->flags |= DM_UEVENT_GENERATED_FLAG; |
| 872 | |
| 873 | dm_put(md); |
| 874 | dm_destroy(md); |
| 875 | return 0; |
| 876 | } |
| 877 | |
| 878 | /* |
| 879 | * Check a string doesn't overrun the chunk of |
| 880 | * memory we copied from userland. |
| 881 | */ |
| 882 | static int invalid_str(char *str, void *end) |
| 883 | { |
| 884 | while ((void *) str < end) |
| 885 | if (!*str++) |
| 886 | return 0; |
| 887 | |
| 888 | return -EINVAL; |
| 889 | } |
| 890 | |
| 891 | static int dev_rename(struct dm_ioctl *param, size_t param_size) |
| 892 | { |
| 893 | int r; |
| 894 | char *new_data = (char *) param + param->data_start; |
| 895 | struct mapped_device *md; |
| 896 | unsigned change_uuid = (param->flags & DM_UUID_FLAG) ? 1 : 0; |
| 897 | |
| 898 | if (new_data < param->data || |
| 899 | invalid_str(new_data, (void *) param + param_size) || !*new_data || |
| 900 | strlen(new_data) > (change_uuid ? DM_UUID_LEN - 1 : DM_NAME_LEN - 1)) { |
| 901 | DMWARN("Invalid new mapped device name or uuid string supplied."); |
| 902 | return -EINVAL; |
| 903 | } |
| 904 | |
| 905 | if (!change_uuid) { |
| 906 | r = check_name(new_data); |
| 907 | if (r) |
| 908 | return r; |
| 909 | } |
| 910 | |
| 911 | md = dm_hash_rename(param, new_data); |
| 912 | if (IS_ERR(md)) |
| 913 | return PTR_ERR(md); |
| 914 | |
| 915 | __dev_status(md, param); |
| 916 | dm_put(md); |
| 917 | |
| 918 | return 0; |
| 919 | } |
| 920 | |
| 921 | static int dev_set_geometry(struct dm_ioctl *param, size_t param_size) |
| 922 | { |
| 923 | int r = -EINVAL, x; |
| 924 | struct mapped_device *md; |
| 925 | struct hd_geometry geometry; |
| 926 | unsigned long indata[4]; |
| 927 | char *geostr = (char *) param + param->data_start; |
| 928 | char dummy; |
| 929 | |
| 930 | md = find_device(param); |
| 931 | if (!md) |
| 932 | return -ENXIO; |
| 933 | |
| 934 | if (geostr < param->data || |
| 935 | invalid_str(geostr, (void *) param + param_size)) { |
| 936 | DMWARN("Invalid geometry supplied."); |
| 937 | goto out; |
| 938 | } |
| 939 | |
| 940 | x = sscanf(geostr, "%lu %lu %lu %lu%c", indata, |
| 941 | indata + 1, indata + 2, indata + 3, &dummy); |
| 942 | |
| 943 | if (x != 4) { |
| 944 | DMWARN("Unable to interpret geometry settings."); |
| 945 | goto out; |
| 946 | } |
| 947 | |
| 948 | if (indata[0] > 65535 || indata[1] > 255 || |
| 949 | indata[2] > 255 || indata[3] > ULONG_MAX) { |
| 950 | DMWARN("Geometry exceeds range limits."); |
| 951 | goto out; |
| 952 | } |
| 953 | |
| 954 | geometry.cylinders = indata[0]; |
| 955 | geometry.heads = indata[1]; |
| 956 | geometry.sectors = indata[2]; |
| 957 | geometry.start = indata[3]; |
| 958 | |
| 959 | r = dm_set_geometry(md, &geometry); |
| 960 | |
| 961 | param->data_size = 0; |
| 962 | |
| 963 | out: |
| 964 | dm_put(md); |
| 965 | return r; |
| 966 | } |
| 967 | |
| 968 | static int do_suspend(struct dm_ioctl *param) |
| 969 | { |
| 970 | int r = 0; |
| 971 | unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG; |
| 972 | struct mapped_device *md; |
| 973 | |
| 974 | md = find_device(param); |
| 975 | if (!md) |
| 976 | return -ENXIO; |
| 977 | |
| 978 | if (param->flags & DM_SKIP_LOCKFS_FLAG) |
| 979 | suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG; |
| 980 | if (param->flags & DM_NOFLUSH_FLAG) |
| 981 | suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG; |
| 982 | |
| 983 | if (!dm_suspended_md(md)) { |
| 984 | r = dm_suspend(md, suspend_flags); |
| 985 | if (r) |
| 986 | goto out; |
| 987 | } |
| 988 | |
| 989 | __dev_status(md, param); |
| 990 | |
| 991 | out: |
| 992 | dm_put(md); |
| 993 | |
| 994 | return r; |
| 995 | } |
| 996 | |
| 997 | static int do_resume(struct dm_ioctl *param) |
| 998 | { |
| 999 | int r = 0; |
| 1000 | unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG; |
| 1001 | struct hash_cell *hc; |
| 1002 | struct mapped_device *md; |
| 1003 | struct dm_table *new_map, *old_map = NULL; |
| 1004 | |
| 1005 | down_write(&_hash_lock); |
| 1006 | |
| 1007 | hc = __find_device_hash_cell(param); |
| 1008 | if (!hc) { |
| 1009 | DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table."); |
| 1010 | up_write(&_hash_lock); |
| 1011 | return -ENXIO; |
| 1012 | } |
| 1013 | |
| 1014 | md = hc->md; |
| 1015 | |
| 1016 | new_map = hc->new_map; |
| 1017 | hc->new_map = NULL; |
| 1018 | param->flags &= ~DM_INACTIVE_PRESENT_FLAG; |
| 1019 | |
| 1020 | up_write(&_hash_lock); |
| 1021 | |
| 1022 | /* Do we need to load a new map ? */ |
| 1023 | if (new_map) { |
| 1024 | /* Suspend if it isn't already suspended */ |
| 1025 | if (param->flags & DM_SKIP_LOCKFS_FLAG) |
| 1026 | suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG; |
| 1027 | if (param->flags & DM_NOFLUSH_FLAG) |
| 1028 | suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG; |
| 1029 | if (!dm_suspended_md(md)) |
| 1030 | dm_suspend(md, suspend_flags); |
| 1031 | |
| 1032 | old_map = dm_swap_table(md, new_map); |
| 1033 | if (IS_ERR(old_map)) { |
| 1034 | dm_sync_table(md); |
| 1035 | dm_table_destroy(new_map); |
| 1036 | dm_put(md); |
| 1037 | return PTR_ERR(old_map); |
| 1038 | } |
| 1039 | |
| 1040 | if (dm_table_get_mode(new_map) & FMODE_WRITE) |
| 1041 | set_disk_ro(dm_disk(md), 0); |
| 1042 | else |
| 1043 | set_disk_ro(dm_disk(md), 1); |
| 1044 | } |
| 1045 | |
| 1046 | if (dm_suspended_md(md)) { |
| 1047 | r = dm_resume(md); |
| 1048 | if (!r && !dm_kobject_uevent(md, KOBJ_CHANGE, param->event_nr)) |
| 1049 | param->flags |= DM_UEVENT_GENERATED_FLAG; |
| 1050 | } |
| 1051 | |
| 1052 | /* |
| 1053 | * Since dm_swap_table synchronizes RCU, nobody should be in |
| 1054 | * read-side critical section already. |
| 1055 | */ |
| 1056 | if (old_map) |
| 1057 | dm_table_destroy(old_map); |
| 1058 | |
| 1059 | if (!r) |
| 1060 | __dev_status(md, param); |
| 1061 | |
| 1062 | dm_put(md); |
| 1063 | return r; |
| 1064 | } |
| 1065 | |
| 1066 | /* |
| 1067 | * Set or unset the suspension state of a device. |
| 1068 | * If the device already is in the requested state we just return its status. |
| 1069 | */ |
| 1070 | static int dev_suspend(struct dm_ioctl *param, size_t param_size) |
| 1071 | { |
| 1072 | if (param->flags & DM_SUSPEND_FLAG) |
| 1073 | return do_suspend(param); |
| 1074 | |
| 1075 | return do_resume(param); |
| 1076 | } |
| 1077 | |
| 1078 | /* |
| 1079 | * Copies device info back to user space, used by |
| 1080 | * the create and info ioctls. |
| 1081 | */ |
| 1082 | static int dev_status(struct dm_ioctl *param, size_t param_size) |
| 1083 | { |
| 1084 | struct mapped_device *md; |
| 1085 | |
| 1086 | md = find_device(param); |
| 1087 | if (!md) |
| 1088 | return -ENXIO; |
| 1089 | |
| 1090 | __dev_status(md, param); |
| 1091 | dm_put(md); |
| 1092 | |
| 1093 | return 0; |
| 1094 | } |
| 1095 | |
| 1096 | /* |
| 1097 | * Build up the status struct for each target |
| 1098 | */ |
| 1099 | static void retrieve_status(struct dm_table *table, |
| 1100 | struct dm_ioctl *param, size_t param_size) |
| 1101 | { |
| 1102 | unsigned int i, num_targets; |
| 1103 | struct dm_target_spec *spec; |
| 1104 | char *outbuf, *outptr; |
| 1105 | status_type_t type; |
| 1106 | size_t remaining, len, used = 0; |
| 1107 | unsigned status_flags = 0; |
| 1108 | |
| 1109 | outptr = outbuf = get_result_buffer(param, param_size, &len); |
| 1110 | |
| 1111 | if (param->flags & DM_STATUS_TABLE_FLAG) |
| 1112 | type = STATUSTYPE_TABLE; |
| 1113 | else |
| 1114 | type = STATUSTYPE_INFO; |
| 1115 | |
| 1116 | /* Get all the target info */ |
| 1117 | num_targets = dm_table_get_num_targets(table); |
| 1118 | for (i = 0; i < num_targets; i++) { |
| 1119 | struct dm_target *ti = dm_table_get_target(table, i); |
| 1120 | size_t l; |
| 1121 | |
| 1122 | remaining = len - (outptr - outbuf); |
| 1123 | if (remaining <= sizeof(struct dm_target_spec)) { |
| 1124 | param->flags |= DM_BUFFER_FULL_FLAG; |
| 1125 | break; |
| 1126 | } |
| 1127 | |
| 1128 | spec = (struct dm_target_spec *) outptr; |
| 1129 | |
| 1130 | spec->status = 0; |
| 1131 | spec->sector_start = ti->begin; |
| 1132 | spec->length = ti->len; |
| 1133 | strncpy(spec->target_type, ti->type->name, |
| 1134 | sizeof(spec->target_type)); |
| 1135 | |
| 1136 | outptr += sizeof(struct dm_target_spec); |
| 1137 | remaining = len - (outptr - outbuf); |
| 1138 | if (remaining <= 0) { |
| 1139 | param->flags |= DM_BUFFER_FULL_FLAG; |
| 1140 | break; |
| 1141 | } |
| 1142 | |
| 1143 | /* Get the status/table string from the target driver */ |
| 1144 | if (ti->type->status) { |
| 1145 | if (param->flags & DM_NOFLUSH_FLAG) |
| 1146 | status_flags |= DM_STATUS_NOFLUSH_FLAG; |
| 1147 | ti->type->status(ti, type, status_flags, outptr, remaining); |
| 1148 | } else |
| 1149 | outptr[0] = '\0'; |
| 1150 | |
| 1151 | l = strlen(outptr) + 1; |
| 1152 | if (l == remaining) { |
| 1153 | param->flags |= DM_BUFFER_FULL_FLAG; |
| 1154 | break; |
| 1155 | } |
| 1156 | |
| 1157 | outptr += l; |
| 1158 | used = param->data_start + (outptr - outbuf); |
| 1159 | |
| 1160 | outptr = align_ptr(outptr); |
| 1161 | spec->next = outptr - outbuf; |
| 1162 | } |
| 1163 | |
| 1164 | if (used) |
| 1165 | param->data_size = used; |
| 1166 | |
| 1167 | param->target_count = num_targets; |
| 1168 | } |
| 1169 | |
| 1170 | /* |
| 1171 | * Wait for a device to report an event |
| 1172 | */ |
| 1173 | static int dev_wait(struct dm_ioctl *param, size_t param_size) |
| 1174 | { |
| 1175 | int r = 0; |
| 1176 | struct mapped_device *md; |
| 1177 | struct dm_table *table; |
| 1178 | int srcu_idx; |
| 1179 | |
| 1180 | md = find_device(param); |
| 1181 | if (!md) |
| 1182 | return -ENXIO; |
| 1183 | |
| 1184 | /* |
| 1185 | * Wait for a notification event |
| 1186 | */ |
| 1187 | if (dm_wait_event(md, param->event_nr)) { |
| 1188 | r = -ERESTARTSYS; |
| 1189 | goto out; |
| 1190 | } |
| 1191 | |
| 1192 | /* |
| 1193 | * The userland program is going to want to know what |
| 1194 | * changed to trigger the event, so we may as well tell |
| 1195 | * him and save an ioctl. |
| 1196 | */ |
| 1197 | __dev_status(md, param); |
| 1198 | |
| 1199 | table = dm_get_live_or_inactive_table(md, param, &srcu_idx); |
| 1200 | if (table) |
| 1201 | retrieve_status(table, param, param_size); |
| 1202 | dm_put_live_table(md, srcu_idx); |
| 1203 | |
| 1204 | out: |
| 1205 | dm_put(md); |
| 1206 | |
| 1207 | return r; |
| 1208 | } |
| 1209 | |
| 1210 | static inline fmode_t get_mode(struct dm_ioctl *param) |
| 1211 | { |
| 1212 | fmode_t mode = FMODE_READ | FMODE_WRITE; |
| 1213 | |
| 1214 | if (param->flags & DM_READONLY_FLAG) |
| 1215 | mode = FMODE_READ; |
| 1216 | |
| 1217 | return mode; |
| 1218 | } |
| 1219 | |
| 1220 | static int next_target(struct dm_target_spec *last, uint32_t next, void *end, |
| 1221 | struct dm_target_spec **spec, char **target_params) |
| 1222 | { |
| 1223 | *spec = (struct dm_target_spec *) ((unsigned char *) last + next); |
| 1224 | *target_params = (char *) (*spec + 1); |
| 1225 | |
| 1226 | if (*spec < (last + 1)) |
| 1227 | return -EINVAL; |
| 1228 | |
| 1229 | return invalid_str(*target_params, end); |
| 1230 | } |
| 1231 | |
| 1232 | static int populate_table(struct dm_table *table, |
| 1233 | struct dm_ioctl *param, size_t param_size) |
| 1234 | { |
| 1235 | int r; |
| 1236 | unsigned int i = 0; |
| 1237 | struct dm_target_spec *spec = (struct dm_target_spec *) param; |
| 1238 | uint32_t next = param->data_start; |
| 1239 | void *end = (void *) param + param_size; |
| 1240 | char *target_params; |
| 1241 | |
| 1242 | if (!param->target_count) { |
| 1243 | DMWARN("populate_table: no targets specified"); |
| 1244 | return -EINVAL; |
| 1245 | } |
| 1246 | |
| 1247 | for (i = 0; i < param->target_count; i++) { |
| 1248 | |
| 1249 | r = next_target(spec, next, end, &spec, &target_params); |
| 1250 | if (r) { |
| 1251 | DMWARN("unable to find target"); |
| 1252 | return r; |
| 1253 | } |
| 1254 | |
| 1255 | r = dm_table_add_target(table, spec->target_type, |
| 1256 | (sector_t) spec->sector_start, |
| 1257 | (sector_t) spec->length, |
| 1258 | target_params); |
| 1259 | if (r) { |
| 1260 | DMWARN("error adding target to table"); |
| 1261 | return r; |
| 1262 | } |
| 1263 | |
| 1264 | next = spec->next; |
| 1265 | } |
| 1266 | |
| 1267 | return dm_table_complete(table); |
| 1268 | } |
| 1269 | |
| 1270 | static int table_load(struct dm_ioctl *param, size_t param_size) |
| 1271 | { |
| 1272 | int r; |
| 1273 | struct hash_cell *hc; |
| 1274 | struct dm_table *t, *old_map = NULL; |
| 1275 | struct mapped_device *md; |
| 1276 | struct target_type *immutable_target_type; |
| 1277 | |
| 1278 | md = find_device(param); |
| 1279 | if (!md) |
| 1280 | return -ENXIO; |
| 1281 | |
| 1282 | r = dm_table_create(&t, get_mode(param), param->target_count, md); |
| 1283 | if (r) |
| 1284 | goto err; |
| 1285 | |
| 1286 | /* Protect md->type and md->queue against concurrent table loads. */ |
| 1287 | dm_lock_md_type(md); |
| 1288 | r = populate_table(t, param, param_size); |
| 1289 | if (r) |
| 1290 | goto err_unlock_md_type; |
| 1291 | |
| 1292 | immutable_target_type = dm_get_immutable_target_type(md); |
| 1293 | if (immutable_target_type && |
| 1294 | (immutable_target_type != dm_table_get_immutable_target_type(t))) { |
| 1295 | DMWARN("can't replace immutable target type %s", |
| 1296 | immutable_target_type->name); |
| 1297 | r = -EINVAL; |
| 1298 | goto err_unlock_md_type; |
| 1299 | } |
| 1300 | |
| 1301 | if (dm_get_md_type(md) == DM_TYPE_NONE) { |
| 1302 | /* Initial table load: acquire type of table. */ |
| 1303 | dm_set_md_type(md, dm_table_get_type(t)); |
| 1304 | |
| 1305 | /* setup md->queue to reflect md's type (may block) */ |
| 1306 | r = dm_setup_md_queue(md); |
| 1307 | if (r) { |
| 1308 | DMWARN("unable to set up device queue for new table."); |
| 1309 | goto err_unlock_md_type; |
| 1310 | } |
| 1311 | } else if (dm_get_md_type(md) != dm_table_get_type(t)) { |
| 1312 | DMWARN("can't change device type after initial table load."); |
| 1313 | r = -EINVAL; |
| 1314 | goto err_unlock_md_type; |
| 1315 | } |
| 1316 | |
| 1317 | dm_unlock_md_type(md); |
| 1318 | |
| 1319 | /* stage inactive table */ |
| 1320 | down_write(&_hash_lock); |
| 1321 | hc = dm_get_mdptr(md); |
| 1322 | if (!hc || hc->md != md) { |
| 1323 | DMWARN("device has been removed from the dev hash table."); |
| 1324 | up_write(&_hash_lock); |
| 1325 | r = -ENXIO; |
| 1326 | goto err_destroy_table; |
| 1327 | } |
| 1328 | |
| 1329 | if (hc->new_map) |
| 1330 | old_map = hc->new_map; |
| 1331 | hc->new_map = t; |
| 1332 | up_write(&_hash_lock); |
| 1333 | |
| 1334 | param->flags |= DM_INACTIVE_PRESENT_FLAG; |
| 1335 | __dev_status(md, param); |
| 1336 | |
| 1337 | if (old_map) { |
| 1338 | dm_sync_table(md); |
| 1339 | dm_table_destroy(old_map); |
| 1340 | } |
| 1341 | |
| 1342 | dm_put(md); |
| 1343 | |
| 1344 | return 0; |
| 1345 | |
| 1346 | err_unlock_md_type: |
| 1347 | dm_unlock_md_type(md); |
| 1348 | err_destroy_table: |
| 1349 | dm_table_destroy(t); |
| 1350 | err: |
| 1351 | dm_put(md); |
| 1352 | |
| 1353 | return r; |
| 1354 | } |
| 1355 | |
| 1356 | static int table_clear(struct dm_ioctl *param, size_t param_size) |
| 1357 | { |
| 1358 | struct hash_cell *hc; |
| 1359 | struct mapped_device *md; |
| 1360 | struct dm_table *old_map = NULL; |
| 1361 | |
| 1362 | down_write(&_hash_lock); |
| 1363 | |
| 1364 | hc = __find_device_hash_cell(param); |
| 1365 | if (!hc) { |
| 1366 | DMDEBUG_LIMIT("device doesn't appear to be in the dev hash table."); |
| 1367 | up_write(&_hash_lock); |
| 1368 | return -ENXIO; |
| 1369 | } |
| 1370 | |
| 1371 | if (hc->new_map) { |
| 1372 | old_map = hc->new_map; |
| 1373 | hc->new_map = NULL; |
| 1374 | } |
| 1375 | |
| 1376 | param->flags &= ~DM_INACTIVE_PRESENT_FLAG; |
| 1377 | |
| 1378 | __dev_status(hc->md, param); |
| 1379 | md = hc->md; |
| 1380 | up_write(&_hash_lock); |
| 1381 | if (old_map) { |
| 1382 | dm_sync_table(md); |
| 1383 | dm_table_destroy(old_map); |
| 1384 | } |
| 1385 | dm_put(md); |
| 1386 | |
| 1387 | return 0; |
| 1388 | } |
| 1389 | |
| 1390 | /* |
| 1391 | * Retrieves a list of devices used by a particular dm device. |
| 1392 | */ |
| 1393 | static void retrieve_deps(struct dm_table *table, |
| 1394 | struct dm_ioctl *param, size_t param_size) |
| 1395 | { |
| 1396 | unsigned int count = 0; |
| 1397 | struct list_head *tmp; |
| 1398 | size_t len, needed; |
| 1399 | struct dm_dev_internal *dd; |
| 1400 | struct dm_target_deps *deps; |
| 1401 | |
| 1402 | deps = get_result_buffer(param, param_size, &len); |
| 1403 | |
| 1404 | /* |
| 1405 | * Count the devices. |
| 1406 | */ |
| 1407 | list_for_each (tmp, dm_table_get_devices(table)) |
| 1408 | count++; |
| 1409 | |
| 1410 | /* |
| 1411 | * Check we have enough space. |
| 1412 | */ |
| 1413 | needed = sizeof(*deps) + (sizeof(*deps->dev) * count); |
| 1414 | if (len < needed) { |
| 1415 | param->flags |= DM_BUFFER_FULL_FLAG; |
| 1416 | return; |
| 1417 | } |
| 1418 | |
| 1419 | /* |
| 1420 | * Fill in the devices. |
| 1421 | */ |
| 1422 | deps->count = count; |
| 1423 | count = 0; |
| 1424 | list_for_each_entry (dd, dm_table_get_devices(table), list) |
| 1425 | deps->dev[count++] = huge_encode_dev(dd->dm_dev->bdev->bd_dev); |
| 1426 | |
| 1427 | param->data_size = param->data_start + needed; |
| 1428 | } |
| 1429 | |
| 1430 | static int table_deps(struct dm_ioctl *param, size_t param_size) |
| 1431 | { |
| 1432 | struct mapped_device *md; |
| 1433 | struct dm_table *table; |
| 1434 | int srcu_idx; |
| 1435 | |
| 1436 | md = find_device(param); |
| 1437 | if (!md) |
| 1438 | return -ENXIO; |
| 1439 | |
| 1440 | __dev_status(md, param); |
| 1441 | |
| 1442 | table = dm_get_live_or_inactive_table(md, param, &srcu_idx); |
| 1443 | if (table) |
| 1444 | retrieve_deps(table, param, param_size); |
| 1445 | dm_put_live_table(md, srcu_idx); |
| 1446 | |
| 1447 | dm_put(md); |
| 1448 | |
| 1449 | return 0; |
| 1450 | } |
| 1451 | |
| 1452 | /* |
| 1453 | * Return the status of a device as a text string for each |
| 1454 | * target. |
| 1455 | */ |
| 1456 | static int table_status(struct dm_ioctl *param, size_t param_size) |
| 1457 | { |
| 1458 | struct mapped_device *md; |
| 1459 | struct dm_table *table; |
| 1460 | int srcu_idx; |
| 1461 | |
| 1462 | md = find_device(param); |
| 1463 | if (!md) |
| 1464 | return -ENXIO; |
| 1465 | |
| 1466 | __dev_status(md, param); |
| 1467 | |
| 1468 | table = dm_get_live_or_inactive_table(md, param, &srcu_idx); |
| 1469 | if (table) |
| 1470 | retrieve_status(table, param, param_size); |
| 1471 | dm_put_live_table(md, srcu_idx); |
| 1472 | |
| 1473 | dm_put(md); |
| 1474 | |
| 1475 | return 0; |
| 1476 | } |
| 1477 | |
| 1478 | /* |
| 1479 | * Process device-mapper dependent messages. Messages prefixed with '@' |
| 1480 | * are processed by the DM core. All others are delivered to the target. |
| 1481 | * Returns a number <= 1 if message was processed by device mapper. |
| 1482 | * Returns 2 if message should be delivered to the target. |
| 1483 | */ |
| 1484 | static int message_for_md(struct mapped_device *md, unsigned argc, char **argv, |
| 1485 | char *result, unsigned maxlen) |
| 1486 | { |
| 1487 | int r; |
| 1488 | |
| 1489 | if (**argv != '@') |
| 1490 | return 2; /* no '@' prefix, deliver to target */ |
| 1491 | |
| 1492 | if (!strcasecmp(argv[0], "@cancel_deferred_remove")) { |
| 1493 | if (argc != 1) { |
| 1494 | DMERR("Invalid arguments for @cancel_deferred_remove"); |
| 1495 | return -EINVAL; |
| 1496 | } |
| 1497 | return dm_cancel_deferred_remove(md); |
| 1498 | } |
| 1499 | |
| 1500 | r = dm_stats_message(md, argc, argv, result, maxlen); |
| 1501 | if (r < 2) |
| 1502 | return r; |
| 1503 | |
| 1504 | DMERR("Unsupported message sent to DM core: %s", argv[0]); |
| 1505 | return -EINVAL; |
| 1506 | } |
| 1507 | |
| 1508 | /* |
| 1509 | * Pass a message to the target that's at the supplied device offset. |
| 1510 | */ |
| 1511 | static int target_message(struct dm_ioctl *param, size_t param_size) |
| 1512 | { |
| 1513 | int r, argc; |
| 1514 | char **argv; |
| 1515 | struct mapped_device *md; |
| 1516 | struct dm_table *table; |
| 1517 | struct dm_target *ti; |
| 1518 | struct dm_target_msg *tmsg = (void *) param + param->data_start; |
| 1519 | size_t maxlen; |
| 1520 | char *result = get_result_buffer(param, param_size, &maxlen); |
| 1521 | int srcu_idx; |
| 1522 | |
| 1523 | md = find_device(param); |
| 1524 | if (!md) |
| 1525 | return -ENXIO; |
| 1526 | |
| 1527 | if (tmsg < (struct dm_target_msg *) param->data || |
| 1528 | invalid_str(tmsg->message, (void *) param + param_size)) { |
| 1529 | DMWARN("Invalid target message parameters."); |
| 1530 | r = -EINVAL; |
| 1531 | goto out; |
| 1532 | } |
| 1533 | |
| 1534 | r = dm_split_args(&argc, &argv, tmsg->message); |
| 1535 | if (r) { |
| 1536 | DMWARN("Failed to split target message parameters"); |
| 1537 | goto out; |
| 1538 | } |
| 1539 | |
| 1540 | if (!argc) { |
| 1541 | DMWARN("Empty message received."); |
| 1542 | goto out_argv; |
| 1543 | } |
| 1544 | |
| 1545 | r = message_for_md(md, argc, argv, result, maxlen); |
| 1546 | if (r <= 1) |
| 1547 | goto out_argv; |
| 1548 | |
| 1549 | table = dm_get_live_table(md, &srcu_idx); |
| 1550 | if (!table) |
| 1551 | goto out_table; |
| 1552 | |
| 1553 | if (dm_deleting_md(md)) { |
| 1554 | r = -ENXIO; |
| 1555 | goto out_table; |
| 1556 | } |
| 1557 | |
| 1558 | ti = dm_table_find_target(table, tmsg->sector); |
| 1559 | if (!dm_target_is_valid(ti)) { |
| 1560 | DMWARN("Target message sector outside device."); |
| 1561 | r = -EINVAL; |
| 1562 | } else if (ti->type->message) |
| 1563 | r = ti->type->message(ti, argc, argv); |
| 1564 | else { |
| 1565 | DMWARN("Target type does not support messages"); |
| 1566 | r = -EINVAL; |
| 1567 | } |
| 1568 | |
| 1569 | out_table: |
| 1570 | dm_put_live_table(md, srcu_idx); |
| 1571 | out_argv: |
| 1572 | kfree(argv); |
| 1573 | out: |
| 1574 | if (r >= 0) |
| 1575 | __dev_status(md, param); |
| 1576 | |
| 1577 | if (r == 1) { |
| 1578 | param->flags |= DM_DATA_OUT_FLAG; |
| 1579 | if (dm_message_test_buffer_overflow(result, maxlen)) |
| 1580 | param->flags |= DM_BUFFER_FULL_FLAG; |
| 1581 | else |
| 1582 | param->data_size = param->data_start + strlen(result) + 1; |
| 1583 | r = 0; |
| 1584 | } |
| 1585 | |
| 1586 | dm_put(md); |
| 1587 | return r; |
| 1588 | } |
| 1589 | |
| 1590 | /* |
| 1591 | * The ioctl parameter block consists of two parts, a dm_ioctl struct |
| 1592 | * followed by a data buffer. This flag is set if the second part, |
| 1593 | * which has a variable size, is not used by the function processing |
| 1594 | * the ioctl. |
| 1595 | */ |
| 1596 | #define IOCTL_FLAGS_NO_PARAMS 1 |
| 1597 | |
| 1598 | /*----------------------------------------------------------------- |
| 1599 | * Implementation of open/close/ioctl on the special char |
| 1600 | * device. |
| 1601 | *---------------------------------------------------------------*/ |
| 1602 | static ioctl_fn lookup_ioctl(unsigned int cmd, int *ioctl_flags) |
| 1603 | { |
| 1604 | static struct { |
| 1605 | int cmd; |
| 1606 | int flags; |
| 1607 | ioctl_fn fn; |
| 1608 | } _ioctls[] = { |
| 1609 | {DM_VERSION_CMD, 0, NULL}, /* version is dealt with elsewhere */ |
| 1610 | {DM_REMOVE_ALL_CMD, IOCTL_FLAGS_NO_PARAMS, remove_all}, |
| 1611 | {DM_LIST_DEVICES_CMD, 0, list_devices}, |
| 1612 | |
| 1613 | {DM_DEV_CREATE_CMD, IOCTL_FLAGS_NO_PARAMS, dev_create}, |
| 1614 | {DM_DEV_REMOVE_CMD, IOCTL_FLAGS_NO_PARAMS, dev_remove}, |
| 1615 | {DM_DEV_RENAME_CMD, 0, dev_rename}, |
| 1616 | {DM_DEV_SUSPEND_CMD, IOCTL_FLAGS_NO_PARAMS, dev_suspend}, |
| 1617 | {DM_DEV_STATUS_CMD, IOCTL_FLAGS_NO_PARAMS, dev_status}, |
| 1618 | {DM_DEV_WAIT_CMD, 0, dev_wait}, |
| 1619 | |
| 1620 | {DM_TABLE_LOAD_CMD, 0, table_load}, |
| 1621 | {DM_TABLE_CLEAR_CMD, IOCTL_FLAGS_NO_PARAMS, table_clear}, |
| 1622 | {DM_TABLE_DEPS_CMD, 0, table_deps}, |
| 1623 | {DM_TABLE_STATUS_CMD, 0, table_status}, |
| 1624 | |
| 1625 | {DM_LIST_VERSIONS_CMD, 0, list_versions}, |
| 1626 | |
| 1627 | {DM_TARGET_MSG_CMD, 0, target_message}, |
| 1628 | {DM_DEV_SET_GEOMETRY_CMD, 0, dev_set_geometry} |
| 1629 | }; |
| 1630 | |
| 1631 | if (unlikely(cmd >= ARRAY_SIZE(_ioctls))) |
| 1632 | return NULL; |
| 1633 | |
| 1634 | *ioctl_flags = _ioctls[cmd].flags; |
| 1635 | return _ioctls[cmd].fn; |
| 1636 | } |
| 1637 | |
| 1638 | /* |
| 1639 | * As well as checking the version compatibility this always |
| 1640 | * copies the kernel interface version out. |
| 1641 | */ |
| 1642 | static int check_version(unsigned int cmd, struct dm_ioctl __user *user) |
| 1643 | { |
| 1644 | uint32_t version[3]; |
| 1645 | int r = 0; |
| 1646 | |
| 1647 | if (copy_from_user(version, user->version, sizeof(version))) |
| 1648 | return -EFAULT; |
| 1649 | |
| 1650 | if ((DM_VERSION_MAJOR != version[0]) || |
| 1651 | (DM_VERSION_MINOR < version[1])) { |
| 1652 | DMWARN("ioctl interface mismatch: " |
| 1653 | "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)", |
| 1654 | DM_VERSION_MAJOR, DM_VERSION_MINOR, |
| 1655 | DM_VERSION_PATCHLEVEL, |
| 1656 | version[0], version[1], version[2], cmd); |
| 1657 | r = -EINVAL; |
| 1658 | } |
| 1659 | |
| 1660 | /* |
| 1661 | * Fill in the kernel version. |
| 1662 | */ |
| 1663 | version[0] = DM_VERSION_MAJOR; |
| 1664 | version[1] = DM_VERSION_MINOR; |
| 1665 | version[2] = DM_VERSION_PATCHLEVEL; |
| 1666 | if (copy_to_user(user->version, version, sizeof(version))) |
| 1667 | return -EFAULT; |
| 1668 | |
| 1669 | return r; |
| 1670 | } |
| 1671 | |
| 1672 | #define DM_PARAMS_KMALLOC 0x0001 /* Params alloced with kmalloc */ |
| 1673 | #define DM_PARAMS_VMALLOC 0x0002 /* Params alloced with vmalloc */ |
| 1674 | #define DM_WIPE_BUFFER 0x0010 /* Wipe input buffer before returning from ioctl */ |
| 1675 | |
| 1676 | static void free_params(struct dm_ioctl *param, size_t param_size, int param_flags) |
| 1677 | { |
| 1678 | if (param_flags & DM_WIPE_BUFFER) |
| 1679 | memset(param, 0, param_size); |
| 1680 | |
| 1681 | if (param_flags & DM_PARAMS_KMALLOC) |
| 1682 | kfree(param); |
| 1683 | if (param_flags & DM_PARAMS_VMALLOC) |
| 1684 | vfree(param); |
| 1685 | } |
| 1686 | |
| 1687 | static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl *param_kernel, |
| 1688 | int ioctl_flags, |
| 1689 | struct dm_ioctl **param, int *param_flags) |
| 1690 | { |
| 1691 | struct dm_ioctl *dmi; |
| 1692 | int secure_data; |
| 1693 | const size_t minimum_data_size = sizeof(*param_kernel) - sizeof(param_kernel->data); |
| 1694 | |
| 1695 | if (copy_from_user(param_kernel, user, minimum_data_size)) |
| 1696 | return -EFAULT; |
| 1697 | |
| 1698 | if (param_kernel->data_size < minimum_data_size) |
| 1699 | return -EINVAL; |
| 1700 | |
| 1701 | secure_data = param_kernel->flags & DM_SECURE_DATA_FLAG; |
| 1702 | |
| 1703 | *param_flags = secure_data ? DM_WIPE_BUFFER : 0; |
| 1704 | |
| 1705 | if (ioctl_flags & IOCTL_FLAGS_NO_PARAMS) { |
| 1706 | dmi = param_kernel; |
| 1707 | dmi->data_size = minimum_data_size; |
| 1708 | goto data_copied; |
| 1709 | } |
| 1710 | |
| 1711 | /* |
| 1712 | * Try to avoid low memory issues when a device is suspended. |
| 1713 | * Use kmalloc() rather than vmalloc() when we can. |
| 1714 | */ |
| 1715 | dmi = NULL; |
| 1716 | if (param_kernel->data_size <= KMALLOC_MAX_SIZE) { |
| 1717 | dmi = kmalloc(param_kernel->data_size, GFP_NOIO | __GFP_NORETRY | __GFP_NOMEMALLOC | __GFP_NOWARN); |
| 1718 | if (dmi) |
| 1719 | *param_flags |= DM_PARAMS_KMALLOC; |
| 1720 | } |
| 1721 | |
| 1722 | if (!dmi) { |
| 1723 | unsigned noio_flag; |
| 1724 | noio_flag = memalloc_noio_save(); |
| 1725 | dmi = __vmalloc(param_kernel->data_size, GFP_NOIO | __GFP_REPEAT | __GFP_HIGH | __GFP_HIGHMEM, PAGE_KERNEL); |
| 1726 | memalloc_noio_restore(noio_flag); |
| 1727 | if (dmi) |
| 1728 | *param_flags |= DM_PARAMS_VMALLOC; |
| 1729 | } |
| 1730 | |
| 1731 | if (!dmi) { |
| 1732 | if (secure_data && clear_user(user, param_kernel->data_size)) |
| 1733 | return -EFAULT; |
| 1734 | return -ENOMEM; |
| 1735 | } |
| 1736 | |
| 1737 | if (copy_from_user(dmi, user, param_kernel->data_size)) |
| 1738 | goto bad; |
| 1739 | |
| 1740 | data_copied: |
| 1741 | /* |
| 1742 | * Abort if something changed the ioctl data while it was being copied. |
| 1743 | */ |
| 1744 | if (dmi->data_size != param_kernel->data_size) { |
| 1745 | DMERR("rejecting ioctl: data size modified while processing parameters"); |
| 1746 | goto bad; |
| 1747 | } |
| 1748 | |
| 1749 | /* Wipe the user buffer so we do not return it to userspace */ |
| 1750 | if (secure_data && clear_user(user, param_kernel->data_size)) |
| 1751 | goto bad; |
| 1752 | |
| 1753 | *param = dmi; |
| 1754 | return 0; |
| 1755 | |
| 1756 | bad: |
| 1757 | free_params(dmi, param_kernel->data_size, *param_flags); |
| 1758 | |
| 1759 | return -EFAULT; |
| 1760 | } |
| 1761 | |
| 1762 | static int validate_params(uint cmd, struct dm_ioctl *param) |
| 1763 | { |
| 1764 | /* Always clear this flag */ |
| 1765 | param->flags &= ~DM_BUFFER_FULL_FLAG; |
| 1766 | param->flags &= ~DM_UEVENT_GENERATED_FLAG; |
| 1767 | param->flags &= ~DM_SECURE_DATA_FLAG; |
| 1768 | param->flags &= ~DM_DATA_OUT_FLAG; |
| 1769 | |
| 1770 | /* Ignores parameters */ |
| 1771 | if (cmd == DM_REMOVE_ALL_CMD || |
| 1772 | cmd == DM_LIST_DEVICES_CMD || |
| 1773 | cmd == DM_LIST_VERSIONS_CMD) |
| 1774 | return 0; |
| 1775 | |
| 1776 | if ((cmd == DM_DEV_CREATE_CMD)) { |
| 1777 | if (!*param->name) { |
| 1778 | DMWARN("name not supplied when creating device"); |
| 1779 | return -EINVAL; |
| 1780 | } |
| 1781 | } else if ((*param->uuid && *param->name)) { |
| 1782 | DMWARN("only supply one of name or uuid, cmd(%u)", cmd); |
| 1783 | return -EINVAL; |
| 1784 | } |
| 1785 | |
| 1786 | /* Ensure strings are terminated */ |
| 1787 | param->name[DM_NAME_LEN - 1] = '\0'; |
| 1788 | param->uuid[DM_UUID_LEN - 1] = '\0'; |
| 1789 | |
| 1790 | return 0; |
| 1791 | } |
| 1792 | |
| 1793 | static int ctl_ioctl(uint command, struct dm_ioctl __user *user) |
| 1794 | { |
| 1795 | int r = 0; |
| 1796 | int ioctl_flags; |
| 1797 | int param_flags; |
| 1798 | unsigned int cmd; |
| 1799 | struct dm_ioctl *uninitialized_var(param); |
| 1800 | ioctl_fn fn = NULL; |
| 1801 | size_t input_param_size; |
| 1802 | struct dm_ioctl param_kernel; |
| 1803 | |
| 1804 | /* only root can play with this */ |
| 1805 | if (!capable(CAP_SYS_ADMIN)) |
| 1806 | return -EACCES; |
| 1807 | |
| 1808 | if (_IOC_TYPE(command) != DM_IOCTL) |
| 1809 | return -ENOTTY; |
| 1810 | |
| 1811 | cmd = _IOC_NR(command); |
| 1812 | |
| 1813 | /* |
| 1814 | * Check the interface version passed in. This also |
| 1815 | * writes out the kernel's interface version. |
| 1816 | */ |
| 1817 | r = check_version(cmd, user); |
| 1818 | if (r) |
| 1819 | return r; |
| 1820 | |
| 1821 | /* |
| 1822 | * Nothing more to do for the version command. |
| 1823 | */ |
| 1824 | if (cmd == DM_VERSION_CMD) |
| 1825 | return 0; |
| 1826 | |
| 1827 | fn = lookup_ioctl(cmd, &ioctl_flags); |
| 1828 | if (!fn) { |
| 1829 | DMWARN("dm_ctl_ioctl: unknown command 0x%x", command); |
| 1830 | return -ENOTTY; |
| 1831 | } |
| 1832 | |
| 1833 | /* |
| 1834 | * Copy the parameters into kernel space. |
| 1835 | */ |
| 1836 | r = copy_params(user, ¶m_kernel, ioctl_flags, ¶m, ¶m_flags); |
| 1837 | |
| 1838 | if (r) |
| 1839 | return r; |
| 1840 | |
| 1841 | input_param_size = param->data_size; |
| 1842 | r = validate_params(cmd, param); |
| 1843 | if (r) |
| 1844 | goto out; |
| 1845 | |
| 1846 | param->data_size = offsetof(struct dm_ioctl, data); |
| 1847 | r = fn(param, input_param_size); |
| 1848 | |
| 1849 | if (unlikely(param->flags & DM_BUFFER_FULL_FLAG) && |
| 1850 | unlikely(ioctl_flags & IOCTL_FLAGS_NO_PARAMS)) |
| 1851 | DMERR("ioctl %d tried to output some data but has IOCTL_FLAGS_NO_PARAMS set", cmd); |
| 1852 | |
| 1853 | /* |
| 1854 | * Copy the results back to userland. |
| 1855 | */ |
| 1856 | if (!r && copy_to_user(user, param, param->data_size)) |
| 1857 | r = -EFAULT; |
| 1858 | |
| 1859 | out: |
| 1860 | free_params(param, input_param_size, param_flags); |
| 1861 | return r; |
| 1862 | } |
| 1863 | |
| 1864 | static long dm_ctl_ioctl(struct file *file, uint command, ulong u) |
| 1865 | { |
| 1866 | return (long)ctl_ioctl(command, (struct dm_ioctl __user *)u); |
| 1867 | } |
| 1868 | |
| 1869 | #ifdef CONFIG_COMPAT |
| 1870 | static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u) |
| 1871 | { |
| 1872 | return (long)dm_ctl_ioctl(file, command, (ulong) compat_ptr(u)); |
| 1873 | } |
| 1874 | #else |
| 1875 | #define dm_compat_ctl_ioctl NULL |
| 1876 | #endif |
| 1877 | |
| 1878 | static const struct file_operations _ctl_fops = { |
| 1879 | .open = nonseekable_open, |
| 1880 | .unlocked_ioctl = dm_ctl_ioctl, |
| 1881 | .compat_ioctl = dm_compat_ctl_ioctl, |
| 1882 | .owner = THIS_MODULE, |
| 1883 | .llseek = noop_llseek, |
| 1884 | }; |
| 1885 | |
| 1886 | static struct miscdevice _dm_misc = { |
| 1887 | .minor = MAPPER_CTRL_MINOR, |
| 1888 | .name = DM_NAME, |
| 1889 | .nodename = DM_DIR "/" DM_CONTROL_NODE, |
| 1890 | .fops = &_ctl_fops |
| 1891 | }; |
| 1892 | |
| 1893 | MODULE_ALIAS_MISCDEV(MAPPER_CTRL_MINOR); |
| 1894 | MODULE_ALIAS("devname:" DM_DIR "/" DM_CONTROL_NODE); |
| 1895 | |
| 1896 | /* |
| 1897 | * Create misc character device and link to DM_DIR/control. |
| 1898 | */ |
| 1899 | int __init dm_interface_init(void) |
| 1900 | { |
| 1901 | int r; |
| 1902 | |
| 1903 | r = dm_hash_init(); |
| 1904 | if (r) |
| 1905 | return r; |
| 1906 | |
| 1907 | r = misc_register(&_dm_misc); |
| 1908 | if (r) { |
| 1909 | DMERR("misc_register failed for control device"); |
| 1910 | dm_hash_exit(); |
| 1911 | return r; |
| 1912 | } |
| 1913 | |
| 1914 | DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR, |
| 1915 | DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA, |
| 1916 | DM_DRIVER_EMAIL); |
| 1917 | return 0; |
| 1918 | } |
| 1919 | |
| 1920 | void dm_interface_exit(void) |
| 1921 | { |
| 1922 | misc_deregister(&_dm_misc); |
| 1923 | dm_hash_exit(); |
| 1924 | } |
| 1925 | |
| 1926 | /** |
| 1927 | * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers |
| 1928 | * @md: Pointer to mapped_device |
| 1929 | * @name: Buffer (size DM_NAME_LEN) for name |
| 1930 | * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined |
| 1931 | */ |
| 1932 | int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid) |
| 1933 | { |
| 1934 | int r = 0; |
| 1935 | struct hash_cell *hc; |
| 1936 | |
| 1937 | if (!md) |
| 1938 | return -ENXIO; |
| 1939 | |
| 1940 | mutex_lock(&dm_hash_cells_mutex); |
| 1941 | hc = dm_get_mdptr(md); |
| 1942 | if (!hc || hc->md != md) { |
| 1943 | r = -ENXIO; |
| 1944 | goto out; |
| 1945 | } |
| 1946 | |
| 1947 | if (name) |
| 1948 | strcpy(name, hc->name); |
| 1949 | if (uuid) |
| 1950 | strcpy(uuid, hc->uuid ? : ""); |
| 1951 | |
| 1952 | out: |
| 1953 | mutex_unlock(&dm_hash_cells_mutex); |
| 1954 | |
| 1955 | return r; |
| 1956 | } |