1 /* 2 * Copyright (C) 2001, 2002 Sistina Software (UK) Limited. 3 * Copyright (C) 2004 - 2006 Red Hat, Inc. All rights reserved. 4 * 5 * This file is released under the GPL. 6 */ 7 8 #include "dm.h" 9 10 #include <linux/module.h> 11 #include <linux/vmalloc.h> 12 #include <linux/miscdevice.h> 13 #include <linux/init.h> 14 #include <linux/wait.h> 15 #include <linux/slab.h> 16 #include <linux/dm-ioctl.h> 17 #include <linux/hdreg.h> 18 #include <linux/compat.h> 19 20 #include <asm/uaccess.h> 21 22 #define DM_MSG_PREFIX "ioctl" 23 #define DM_DRIVER_EMAIL "dm-devel@redhat.com" 24 25 /*----------------------------------------------------------------- 26 * The ioctl interface needs to be able to look up devices by 27 * name or uuid. 28 *---------------------------------------------------------------*/ 29 struct hash_cell { 30 struct list_head name_list; 31 struct list_head uuid_list; 32 33 char *name; 34 char *uuid; 35 struct mapped_device *md; 36 struct dm_table *new_map; 37 }; 38 39 struct vers_iter { 40 size_t param_size; 41 struct dm_target_versions *vers, *old_vers; 42 char *end; 43 uint32_t flags; 44 }; 45 46 47 #define NUM_BUCKETS 64 48 #define MASK_BUCKETS (NUM_BUCKETS - 1) 49 static struct list_head _name_buckets[NUM_BUCKETS]; 50 static struct list_head _uuid_buckets[NUM_BUCKETS]; 51 52 static void dm_hash_remove_all(int keep_open_devices); 53 54 /* 55 * Guards access to both hash tables. 56 */ 57 static DECLARE_RWSEM(_hash_lock); 58 59 static void init_buckets(struct list_head *buckets) 60 { 61 unsigned int i; 62 63 for (i = 0; i < NUM_BUCKETS; i++) 64 INIT_LIST_HEAD(buckets + i); 65 } 66 67 static int dm_hash_init(void) 68 { 69 init_buckets(_name_buckets); 70 init_buckets(_uuid_buckets); 71 return 0; 72 } 73 74 static void dm_hash_exit(void) 75 { 76 dm_hash_remove_all(0); 77 } 78 79 /*----------------------------------------------------------------- 80 * Hash function: 81 * We're not really concerned with the str hash function being 82 * fast since it's only used by the ioctl interface. 83 *---------------------------------------------------------------*/ 84 static unsigned int hash_str(const char *str) 85 { 86 const unsigned int hash_mult = 2654435387U; 87 unsigned int h = 0; 88 89 while (*str) 90 h = (h + (unsigned int) *str++) * hash_mult; 91 92 return h & MASK_BUCKETS; 93 } 94 95 /*----------------------------------------------------------------- 96 * Code for looking up a device by name 97 *---------------------------------------------------------------*/ 98 static struct hash_cell *__get_name_cell(const char *str) 99 { 100 struct hash_cell *hc; 101 unsigned int h = hash_str(str); 102 103 list_for_each_entry (hc, _name_buckets + h, name_list) 104 if (!strcmp(hc->name, str)) { 105 dm_get(hc->md); 106 return hc; 107 } 108 109 return NULL; 110 } 111 112 static struct hash_cell *__get_uuid_cell(const char *str) 113 { 114 struct hash_cell *hc; 115 unsigned int h = hash_str(str); 116 117 list_for_each_entry (hc, _uuid_buckets + h, uuid_list) 118 if (!strcmp(hc->uuid, str)) { 119 dm_get(hc->md); 120 return hc; 121 } 122 123 return NULL; 124 } 125 126 /*----------------------------------------------------------------- 127 * Inserting, removing and renaming a device. 128 *---------------------------------------------------------------*/ 129 static struct hash_cell *alloc_cell(const char *name, const char *uuid, 130 struct mapped_device *md) 131 { 132 struct hash_cell *hc; 133 134 hc = kmalloc(sizeof(*hc), GFP_KERNEL); 135 if (!hc) 136 return NULL; 137 138 hc->name = kstrdup(name, GFP_KERNEL); 139 if (!hc->name) { 140 kfree(hc); 141 return NULL; 142 } 143 144 if (!uuid) 145 hc->uuid = NULL; 146 147 else { 148 hc->uuid = kstrdup(uuid, GFP_KERNEL); 149 if (!hc->uuid) { 150 kfree(hc->name); 151 kfree(hc); 152 return NULL; 153 } 154 } 155 156 INIT_LIST_HEAD(&hc->name_list); 157 INIT_LIST_HEAD(&hc->uuid_list); 158 hc->md = md; 159 hc->new_map = NULL; 160 return hc; 161 } 162 163 static void free_cell(struct hash_cell *hc) 164 { 165 if (hc) { 166 kfree(hc->name); 167 kfree(hc->uuid); 168 kfree(hc); 169 } 170 } 171 172 /* 173 * The kdev_t and uuid of a device can never change once it is 174 * initially inserted. 175 */ 176 static int dm_hash_insert(const char *name, const char *uuid, struct mapped_device *md) 177 { 178 struct hash_cell *cell, *hc; 179 180 /* 181 * Allocate the new cells. 182 */ 183 cell = alloc_cell(name, uuid, md); 184 if (!cell) 185 return -ENOMEM; 186 187 /* 188 * Insert the cell into both hash tables. 189 */ 190 down_write(&_hash_lock); 191 hc = __get_name_cell(name); 192 if (hc) { 193 dm_put(hc->md); 194 goto bad; 195 } 196 197 list_add(&cell->name_list, _name_buckets + hash_str(name)); 198 199 if (uuid) { 200 hc = __get_uuid_cell(uuid); 201 if (hc) { 202 list_del(&cell->name_list); 203 dm_put(hc->md); 204 goto bad; 205 } 206 list_add(&cell->uuid_list, _uuid_buckets + hash_str(uuid)); 207 } 208 dm_get(md); 209 dm_set_mdptr(md, cell); 210 up_write(&_hash_lock); 211 212 return 0; 213 214 bad: 215 up_write(&_hash_lock); 216 free_cell(cell); 217 return -EBUSY; 218 } 219 220 static void __hash_remove(struct hash_cell *hc) 221 { 222 struct dm_table *table; 223 224 /* remove from the dev hash */ 225 list_del(&hc->uuid_list); 226 list_del(&hc->name_list); 227 dm_set_mdptr(hc->md, NULL); 228 229 table = dm_get_table(hc->md); 230 if (table) { 231 dm_table_event(table); 232 dm_table_put(table); 233 } 234 235 if (hc->new_map) 236 dm_table_destroy(hc->new_map); 237 dm_put(hc->md); 238 free_cell(hc); 239 } 240 241 static void dm_hash_remove_all(int keep_open_devices) 242 { 243 int i, dev_skipped, dev_removed; 244 struct hash_cell *hc; 245 struct list_head *tmp, *n; 246 247 down_write(&_hash_lock); 248 249 retry: 250 dev_skipped = dev_removed = 0; 251 for (i = 0; i < NUM_BUCKETS; i++) { 252 list_for_each_safe (tmp, n, _name_buckets + i) { 253 hc = list_entry(tmp, struct hash_cell, name_list); 254 255 if (keep_open_devices && 256 dm_lock_for_deletion(hc->md)) { 257 dev_skipped++; 258 continue; 259 } 260 __hash_remove(hc); 261 dev_removed = 1; 262 } 263 } 264 265 /* 266 * Some mapped devices may be using other mapped devices, so if any 267 * still exist, repeat until we make no further progress. 268 */ 269 if (dev_skipped) { 270 if (dev_removed) 271 goto retry; 272 273 DMWARN("remove_all left %d open device(s)", dev_skipped); 274 } 275 276 up_write(&_hash_lock); 277 } 278 279 static int dm_hash_rename(const char *old, const char *new) 280 { 281 char *new_name, *old_name; 282 struct hash_cell *hc; 283 struct dm_table *table; 284 285 /* 286 * duplicate new. 287 */ 288 new_name = kstrdup(new, GFP_KERNEL); 289 if (!new_name) 290 return -ENOMEM; 291 292 down_write(&_hash_lock); 293 294 /* 295 * Is new free ? 296 */ 297 hc = __get_name_cell(new); 298 if (hc) { 299 DMWARN("asked to rename to an already existing name %s -> %s", 300 old, new); 301 dm_put(hc->md); 302 up_write(&_hash_lock); 303 kfree(new_name); 304 return -EBUSY; 305 } 306 307 /* 308 * Is there such a device as 'old' ? 309 */ 310 hc = __get_name_cell(old); 311 if (!hc) { 312 DMWARN("asked to rename a non existent device %s -> %s", 313 old, new); 314 up_write(&_hash_lock); 315 kfree(new_name); 316 return -ENXIO; 317 } 318 319 /* 320 * rename and move the name cell. 321 */ 322 list_del(&hc->name_list); 323 old_name = hc->name; 324 hc->name = new_name; 325 list_add(&hc->name_list, _name_buckets + hash_str(new_name)); 326 327 /* 328 * Wake up any dm event waiters. 329 */ 330 table = dm_get_table(hc->md); 331 if (table) { 332 dm_table_event(table); 333 dm_table_put(table); 334 } 335 336 dm_kobject_uevent(hc->md); 337 338 dm_put(hc->md); 339 up_write(&_hash_lock); 340 kfree(old_name); 341 return 0; 342 } 343 344 /*----------------------------------------------------------------- 345 * Implementation of the ioctl commands 346 *---------------------------------------------------------------*/ 347 /* 348 * All the ioctl commands get dispatched to functions with this 349 * prototype. 350 */ 351 typedef int (*ioctl_fn)(struct dm_ioctl *param, size_t param_size); 352 353 static int remove_all(struct dm_ioctl *param, size_t param_size) 354 { 355 dm_hash_remove_all(1); 356 param->data_size = 0; 357 return 0; 358 } 359 360 /* 361 * Round up the ptr to an 8-byte boundary. 362 */ 363 #define ALIGN_MASK 7 364 static inline void *align_ptr(void *ptr) 365 { 366 return (void *) (((size_t) (ptr + ALIGN_MASK)) & ~ALIGN_MASK); 367 } 368 369 /* 370 * Retrieves the data payload buffer from an already allocated 371 * struct dm_ioctl. 372 */ 373 static void *get_result_buffer(struct dm_ioctl *param, size_t param_size, 374 size_t *len) 375 { 376 param->data_start = align_ptr(param + 1) - (void *) param; 377 378 if (param->data_start < param_size) 379 *len = param_size - param->data_start; 380 else 381 *len = 0; 382 383 return ((void *) param) + param->data_start; 384 } 385 386 static int list_devices(struct dm_ioctl *param, size_t param_size) 387 { 388 unsigned int i; 389 struct hash_cell *hc; 390 size_t len, needed = 0; 391 struct gendisk *disk; 392 struct dm_name_list *nl, *old_nl = NULL; 393 394 down_write(&_hash_lock); 395 396 /* 397 * Loop through all the devices working out how much 398 * space we need. 399 */ 400 for (i = 0; i < NUM_BUCKETS; i++) { 401 list_for_each_entry (hc, _name_buckets + i, name_list) { 402 needed += sizeof(struct dm_name_list); 403 needed += strlen(hc->name) + 1; 404 needed += ALIGN_MASK; 405 } 406 } 407 408 /* 409 * Grab our output buffer. 410 */ 411 nl = get_result_buffer(param, param_size, &len); 412 if (len < needed) { 413 param->flags |= DM_BUFFER_FULL_FLAG; 414 goto out; 415 } 416 param->data_size = param->data_start + needed; 417 418 nl->dev = 0; /* Flags no data */ 419 420 /* 421 * Now loop through filling out the names. 422 */ 423 for (i = 0; i < NUM_BUCKETS; i++) { 424 list_for_each_entry (hc, _name_buckets + i, name_list) { 425 if (old_nl) 426 old_nl->next = (uint32_t) ((void *) nl - 427 (void *) old_nl); 428 disk = dm_disk(hc->md); 429 nl->dev = huge_encode_dev(disk_devt(disk)); 430 nl->next = 0; 431 strcpy(nl->name, hc->name); 432 433 old_nl = nl; 434 nl = align_ptr(((void *) ++nl) + strlen(hc->name) + 1); 435 } 436 } 437 438 out: 439 up_write(&_hash_lock); 440 return 0; 441 } 442 443 static void list_version_get_needed(struct target_type *tt, void *needed_param) 444 { 445 size_t *needed = needed_param; 446 447 *needed += sizeof(struct dm_target_versions); 448 *needed += strlen(tt->name); 449 *needed += ALIGN_MASK; 450 } 451 452 static void list_version_get_info(struct target_type *tt, void *param) 453 { 454 struct vers_iter *info = param; 455 456 /* Check space - it might have changed since the first iteration */ 457 if ((char *)info->vers + sizeof(tt->version) + strlen(tt->name) + 1 > 458 info->end) { 459 460 info->flags = DM_BUFFER_FULL_FLAG; 461 return; 462 } 463 464 if (info->old_vers) 465 info->old_vers->next = (uint32_t) ((void *)info->vers - 466 (void *)info->old_vers); 467 info->vers->version[0] = tt->version[0]; 468 info->vers->version[1] = tt->version[1]; 469 info->vers->version[2] = tt->version[2]; 470 info->vers->next = 0; 471 strcpy(info->vers->name, tt->name); 472 473 info->old_vers = info->vers; 474 info->vers = align_ptr(((void *) ++info->vers) + strlen(tt->name) + 1); 475 } 476 477 static int list_versions(struct dm_ioctl *param, size_t param_size) 478 { 479 size_t len, needed = 0; 480 struct dm_target_versions *vers; 481 struct vers_iter iter_info; 482 483 /* 484 * Loop through all the devices working out how much 485 * space we need. 486 */ 487 dm_target_iterate(list_version_get_needed, &needed); 488 489 /* 490 * Grab our output buffer. 491 */ 492 vers = get_result_buffer(param, param_size, &len); 493 if (len < needed) { 494 param->flags |= DM_BUFFER_FULL_FLAG; 495 goto out; 496 } 497 param->data_size = param->data_start + needed; 498 499 iter_info.param_size = param_size; 500 iter_info.old_vers = NULL; 501 iter_info.vers = vers; 502 iter_info.flags = 0; 503 iter_info.end = (char *)vers+len; 504 505 /* 506 * Now loop through filling out the names & versions. 507 */ 508 dm_target_iterate(list_version_get_info, &iter_info); 509 param->flags |= iter_info.flags; 510 511 out: 512 return 0; 513 } 514 515 516 517 static int check_name(const char *name) 518 { 519 if (strchr(name, '/')) { 520 DMWARN("invalid device name"); 521 return -EINVAL; 522 } 523 524 return 0; 525 } 526 527 /* 528 * Fills in a dm_ioctl structure, ready for sending back to 529 * userland. 530 */ 531 static int __dev_status(struct mapped_device *md, struct dm_ioctl *param) 532 { 533 struct gendisk *disk = dm_disk(md); 534 struct dm_table *table; 535 536 param->flags &= ~(DM_SUSPEND_FLAG | DM_READONLY_FLAG | 537 DM_ACTIVE_PRESENT_FLAG); 538 539 if (dm_suspended(md)) 540 param->flags |= DM_SUSPEND_FLAG; 541 542 param->dev = huge_encode_dev(disk_devt(disk)); 543 544 /* 545 * Yes, this will be out of date by the time it gets back 546 * to userland, but it is still very useful for 547 * debugging. 548 */ 549 param->open_count = dm_open_count(md); 550 551 if (get_disk_ro(disk)) 552 param->flags |= DM_READONLY_FLAG; 553 554 param->event_nr = dm_get_event_nr(md); 555 556 table = dm_get_table(md); 557 if (table) { 558 param->flags |= DM_ACTIVE_PRESENT_FLAG; 559 param->target_count = dm_table_get_num_targets(table); 560 dm_table_put(table); 561 } else 562 param->target_count = 0; 563 564 return 0; 565 } 566 567 static int dev_create(struct dm_ioctl *param, size_t param_size) 568 { 569 int r, m = DM_ANY_MINOR; 570 struct mapped_device *md; 571 572 r = check_name(param->name); 573 if (r) 574 return r; 575 576 if (param->flags & DM_PERSISTENT_DEV_FLAG) 577 m = MINOR(huge_decode_dev(param->dev)); 578 579 r = dm_create(m, &md); 580 if (r) 581 return r; 582 583 r = dm_hash_insert(param->name, *param->uuid ? param->uuid : NULL, md); 584 if (r) { 585 dm_put(md); 586 return r; 587 } 588 589 param->flags &= ~DM_INACTIVE_PRESENT_FLAG; 590 591 r = __dev_status(md, param); 592 dm_put(md); 593 594 return r; 595 } 596 597 /* 598 * Always use UUID for lookups if it's present, otherwise use name or dev. 599 */ 600 static struct hash_cell *__find_device_hash_cell(struct dm_ioctl *param) 601 { 602 struct mapped_device *md; 603 void *mdptr = NULL; 604 605 if (*param->uuid) 606 return __get_uuid_cell(param->uuid); 607 608 if (*param->name) 609 return __get_name_cell(param->name); 610 611 md = dm_get_md(huge_decode_dev(param->dev)); 612 if (!md) 613 goto out; 614 615 mdptr = dm_get_mdptr(md); 616 if (!mdptr) 617 dm_put(md); 618 619 out: 620 return mdptr; 621 } 622 623 static struct mapped_device *find_device(struct dm_ioctl *param) 624 { 625 struct hash_cell *hc; 626 struct mapped_device *md = NULL; 627 628 down_read(&_hash_lock); 629 hc = __find_device_hash_cell(param); 630 if (hc) { 631 md = hc->md; 632 633 /* 634 * Sneakily write in both the name and the uuid 635 * while we have the cell. 636 */ 637 strncpy(param->name, hc->name, sizeof(param->name)); 638 if (hc->uuid) 639 strncpy(param->uuid, hc->uuid, sizeof(param->uuid)-1); 640 else 641 param->uuid[0] = '\0'; 642 643 if (hc->new_map) 644 param->flags |= DM_INACTIVE_PRESENT_FLAG; 645 else 646 param->flags &= ~DM_INACTIVE_PRESENT_FLAG; 647 } 648 up_read(&_hash_lock); 649 650 return md; 651 } 652 653 static int dev_remove(struct dm_ioctl *param, size_t param_size) 654 { 655 struct hash_cell *hc; 656 struct mapped_device *md; 657 int r; 658 659 down_write(&_hash_lock); 660 hc = __find_device_hash_cell(param); 661 662 if (!hc) { 663 DMWARN("device doesn't appear to be in the dev hash table."); 664 up_write(&_hash_lock); 665 return -ENXIO; 666 } 667 668 md = hc->md; 669 670 /* 671 * Ensure the device is not open and nothing further can open it. 672 */ 673 r = dm_lock_for_deletion(md); 674 if (r) { 675 DMWARN("unable to remove open device %s", hc->name); 676 up_write(&_hash_lock); 677 dm_put(md); 678 return r; 679 } 680 681 __hash_remove(hc); 682 up_write(&_hash_lock); 683 dm_put(md); 684 param->data_size = 0; 685 return 0; 686 } 687 688 /* 689 * Check a string doesn't overrun the chunk of 690 * memory we copied from userland. 691 */ 692 static int invalid_str(char *str, void *end) 693 { 694 while ((void *) str < end) 695 if (!*str++) 696 return 0; 697 698 return -EINVAL; 699 } 700 701 static int dev_rename(struct dm_ioctl *param, size_t param_size) 702 { 703 int r; 704 char *new_name = (char *) param + param->data_start; 705 706 if (new_name < param->data || 707 invalid_str(new_name, (void *) param + param_size)) { 708 DMWARN("Invalid new logical volume name supplied."); 709 return -EINVAL; 710 } 711 712 r = check_name(new_name); 713 if (r) 714 return r; 715 716 param->data_size = 0; 717 return dm_hash_rename(param->name, new_name); 718 } 719 720 static int dev_set_geometry(struct dm_ioctl *param, size_t param_size) 721 { 722 int r = -EINVAL, x; 723 struct mapped_device *md; 724 struct hd_geometry geometry; 725 unsigned long indata[4]; 726 char *geostr = (char *) param + param->data_start; 727 728 md = find_device(param); 729 if (!md) 730 return -ENXIO; 731 732 if (geostr < param->data || 733 invalid_str(geostr, (void *) param + param_size)) { 734 DMWARN("Invalid geometry supplied."); 735 goto out; 736 } 737 738 x = sscanf(geostr, "%lu %lu %lu %lu", indata, 739 indata + 1, indata + 2, indata + 3); 740 741 if (x != 4) { 742 DMWARN("Unable to interpret geometry settings."); 743 goto out; 744 } 745 746 if (indata[0] > 65535 || indata[1] > 255 || 747 indata[2] > 255 || indata[3] > ULONG_MAX) { 748 DMWARN("Geometry exceeds range limits."); 749 goto out; 750 } 751 752 geometry.cylinders = indata[0]; 753 geometry.heads = indata[1]; 754 geometry.sectors = indata[2]; 755 geometry.start = indata[3]; 756 757 r = dm_set_geometry(md, &geometry); 758 if (!r) 759 r = __dev_status(md, param); 760 761 param->data_size = 0; 762 763 out: 764 dm_put(md); 765 return r; 766 } 767 768 static int do_suspend(struct dm_ioctl *param) 769 { 770 int r = 0; 771 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG; 772 struct mapped_device *md; 773 774 md = find_device(param); 775 if (!md) 776 return -ENXIO; 777 778 if (param->flags & DM_SKIP_LOCKFS_FLAG) 779 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG; 780 if (param->flags & DM_NOFLUSH_FLAG) 781 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG; 782 783 if (!dm_suspended(md)) 784 r = dm_suspend(md, suspend_flags); 785 786 if (!r) 787 r = __dev_status(md, param); 788 789 dm_put(md); 790 return r; 791 } 792 793 static int do_resume(struct dm_ioctl *param) 794 { 795 int r = 0; 796 unsigned suspend_flags = DM_SUSPEND_LOCKFS_FLAG; 797 struct hash_cell *hc; 798 struct mapped_device *md; 799 struct dm_table *new_map; 800 801 down_write(&_hash_lock); 802 803 hc = __find_device_hash_cell(param); 804 if (!hc) { 805 DMWARN("device doesn't appear to be in the dev hash table."); 806 up_write(&_hash_lock); 807 return -ENXIO; 808 } 809 810 md = hc->md; 811 812 new_map = hc->new_map; 813 hc->new_map = NULL; 814 param->flags &= ~DM_INACTIVE_PRESENT_FLAG; 815 816 up_write(&_hash_lock); 817 818 /* Do we need to load a new map ? */ 819 if (new_map) { 820 /* Suspend if it isn't already suspended */ 821 if (param->flags & DM_SKIP_LOCKFS_FLAG) 822 suspend_flags &= ~DM_SUSPEND_LOCKFS_FLAG; 823 if (param->flags & DM_NOFLUSH_FLAG) 824 suspend_flags |= DM_SUSPEND_NOFLUSH_FLAG; 825 if (!dm_suspended(md)) 826 dm_suspend(md, suspend_flags); 827 828 r = dm_swap_table(md, new_map); 829 if (r) { 830 dm_table_destroy(new_map); 831 dm_put(md); 832 return r; 833 } 834 835 if (dm_table_get_mode(new_map) & FMODE_WRITE) 836 set_disk_ro(dm_disk(md), 0); 837 else 838 set_disk_ro(dm_disk(md), 1); 839 } 840 841 if (dm_suspended(md)) 842 r = dm_resume(md); 843 844 if (!r) 845 r = __dev_status(md, param); 846 847 dm_put(md); 848 return r; 849 } 850 851 /* 852 * Set or unset the suspension state of a device. 853 * If the device already is in the requested state we just return its status. 854 */ 855 static int dev_suspend(struct dm_ioctl *param, size_t param_size) 856 { 857 if (param->flags & DM_SUSPEND_FLAG) 858 return do_suspend(param); 859 860 return do_resume(param); 861 } 862 863 /* 864 * Copies device info back to user space, used by 865 * the create and info ioctls. 866 */ 867 static int dev_status(struct dm_ioctl *param, size_t param_size) 868 { 869 int r; 870 struct mapped_device *md; 871 872 md = find_device(param); 873 if (!md) 874 return -ENXIO; 875 876 r = __dev_status(md, param); 877 dm_put(md); 878 return r; 879 } 880 881 /* 882 * Build up the status struct for each target 883 */ 884 static void retrieve_status(struct dm_table *table, 885 struct dm_ioctl *param, size_t param_size) 886 { 887 unsigned int i, num_targets; 888 struct dm_target_spec *spec; 889 char *outbuf, *outptr; 890 status_type_t type; 891 size_t remaining, len, used = 0; 892 893 outptr = outbuf = get_result_buffer(param, param_size, &len); 894 895 if (param->flags & DM_STATUS_TABLE_FLAG) 896 type = STATUSTYPE_TABLE; 897 else 898 type = STATUSTYPE_INFO; 899 900 /* Get all the target info */ 901 num_targets = dm_table_get_num_targets(table); 902 for (i = 0; i < num_targets; i++) { 903 struct dm_target *ti = dm_table_get_target(table, i); 904 905 remaining = len - (outptr - outbuf); 906 if (remaining <= sizeof(struct dm_target_spec)) { 907 param->flags |= DM_BUFFER_FULL_FLAG; 908 break; 909 } 910 911 spec = (struct dm_target_spec *) outptr; 912 913 spec->status = 0; 914 spec->sector_start = ti->begin; 915 spec->length = ti->len; 916 strncpy(spec->target_type, ti->type->name, 917 sizeof(spec->target_type)); 918 919 outptr += sizeof(struct dm_target_spec); 920 remaining = len - (outptr - outbuf); 921 if (remaining <= 0) { 922 param->flags |= DM_BUFFER_FULL_FLAG; 923 break; 924 } 925 926 /* Get the status/table string from the target driver */ 927 if (ti->type->status) { 928 if (ti->type->status(ti, type, outptr, remaining)) { 929 param->flags |= DM_BUFFER_FULL_FLAG; 930 break; 931 } 932 } else 933 outptr[0] = '\0'; 934 935 outptr += strlen(outptr) + 1; 936 used = param->data_start + (outptr - outbuf); 937 938 outptr = align_ptr(outptr); 939 spec->next = outptr - outbuf; 940 } 941 942 if (used) 943 param->data_size = used; 944 945 param->target_count = num_targets; 946 } 947 948 /* 949 * Wait for a device to report an event 950 */ 951 static int dev_wait(struct dm_ioctl *param, size_t param_size) 952 { 953 int r; 954 struct mapped_device *md; 955 struct dm_table *table; 956 957 md = find_device(param); 958 if (!md) 959 return -ENXIO; 960 961 /* 962 * Wait for a notification event 963 */ 964 if (dm_wait_event(md, param->event_nr)) { 965 r = -ERESTARTSYS; 966 goto out; 967 } 968 969 /* 970 * The userland program is going to want to know what 971 * changed to trigger the event, so we may as well tell 972 * him and save an ioctl. 973 */ 974 r = __dev_status(md, param); 975 if (r) 976 goto out; 977 978 table = dm_get_table(md); 979 if (table) { 980 retrieve_status(table, param, param_size); 981 dm_table_put(table); 982 } 983 984 out: 985 dm_put(md); 986 return r; 987 } 988 989 static inline fmode_t get_mode(struct dm_ioctl *param) 990 { 991 fmode_t mode = FMODE_READ | FMODE_WRITE; 992 993 if (param->flags & DM_READONLY_FLAG) 994 mode = FMODE_READ; 995 996 return mode; 997 } 998 999 static int next_target(struct dm_target_spec *last, uint32_t next, void *end, 1000 struct dm_target_spec **spec, char **target_params) 1001 { 1002 *spec = (struct dm_target_spec *) ((unsigned char *) last + next); 1003 *target_params = (char *) (*spec + 1); 1004 1005 if (*spec < (last + 1)) 1006 return -EINVAL; 1007 1008 return invalid_str(*target_params, end); 1009 } 1010 1011 static int populate_table(struct dm_table *table, 1012 struct dm_ioctl *param, size_t param_size) 1013 { 1014 int r; 1015 unsigned int i = 0; 1016 struct dm_target_spec *spec = (struct dm_target_spec *) param; 1017 uint32_t next = param->data_start; 1018 void *end = (void *) param + param_size; 1019 char *target_params; 1020 1021 if (!param->target_count) { 1022 DMWARN("populate_table: no targets specified"); 1023 return -EINVAL; 1024 } 1025 1026 for (i = 0; i < param->target_count; i++) { 1027 1028 r = next_target(spec, next, end, &spec, &target_params); 1029 if (r) { 1030 DMWARN("unable to find target"); 1031 return r; 1032 } 1033 1034 r = dm_table_add_target(table, spec->target_type, 1035 (sector_t) spec->sector_start, 1036 (sector_t) spec->length, 1037 target_params); 1038 if (r) { 1039 DMWARN("error adding target to table"); 1040 return r; 1041 } 1042 1043 next = spec->next; 1044 } 1045 1046 return dm_table_complete(table); 1047 } 1048 1049 static int table_load(struct dm_ioctl *param, size_t param_size) 1050 { 1051 int r; 1052 struct hash_cell *hc; 1053 struct dm_table *t; 1054 struct mapped_device *md; 1055 1056 md = find_device(param); 1057 if (!md) 1058 return -ENXIO; 1059 1060 r = dm_table_create(&t, get_mode(param), param->target_count, md); 1061 if (r) 1062 goto out; 1063 1064 r = populate_table(t, param, param_size); 1065 if (r) { 1066 dm_table_put(t); 1067 goto out; 1068 } 1069 1070 down_write(&_hash_lock); 1071 hc = dm_get_mdptr(md); 1072 if (!hc || hc->md != md) { 1073 DMWARN("device has been removed from the dev hash table."); 1074 dm_table_put(t); 1075 up_write(&_hash_lock); 1076 r = -ENXIO; 1077 goto out; 1078 } 1079 1080 if (hc->new_map) 1081 dm_table_destroy(hc->new_map); 1082 hc->new_map = t; 1083 up_write(&_hash_lock); 1084 1085 param->flags |= DM_INACTIVE_PRESENT_FLAG; 1086 r = __dev_status(md, param); 1087 1088 out: 1089 dm_put(md); 1090 1091 return r; 1092 } 1093 1094 static int table_clear(struct dm_ioctl *param, size_t param_size) 1095 { 1096 int r; 1097 struct hash_cell *hc; 1098 struct mapped_device *md; 1099 1100 down_write(&_hash_lock); 1101 1102 hc = __find_device_hash_cell(param); 1103 if (!hc) { 1104 DMWARN("device doesn't appear to be in the dev hash table."); 1105 up_write(&_hash_lock); 1106 return -ENXIO; 1107 } 1108 1109 if (hc->new_map) { 1110 dm_table_destroy(hc->new_map); 1111 hc->new_map = NULL; 1112 } 1113 1114 param->flags &= ~DM_INACTIVE_PRESENT_FLAG; 1115 1116 r = __dev_status(hc->md, param); 1117 md = hc->md; 1118 up_write(&_hash_lock); 1119 dm_put(md); 1120 return r; 1121 } 1122 1123 /* 1124 * Retrieves a list of devices used by a particular dm device. 1125 */ 1126 static void retrieve_deps(struct dm_table *table, 1127 struct dm_ioctl *param, size_t param_size) 1128 { 1129 unsigned int count = 0; 1130 struct list_head *tmp; 1131 size_t len, needed; 1132 struct dm_dev_internal *dd; 1133 struct dm_target_deps *deps; 1134 1135 deps = get_result_buffer(param, param_size, &len); 1136 1137 /* 1138 * Count the devices. 1139 */ 1140 list_for_each (tmp, dm_table_get_devices(table)) 1141 count++; 1142 1143 /* 1144 * Check we have enough space. 1145 */ 1146 needed = sizeof(*deps) + (sizeof(*deps->dev) * count); 1147 if (len < needed) { 1148 param->flags |= DM_BUFFER_FULL_FLAG; 1149 return; 1150 } 1151 1152 /* 1153 * Fill in the devices. 1154 */ 1155 deps->count = count; 1156 count = 0; 1157 list_for_each_entry (dd, dm_table_get_devices(table), list) 1158 deps->dev[count++] = huge_encode_dev(dd->dm_dev.bdev->bd_dev); 1159 1160 param->data_size = param->data_start + needed; 1161 } 1162 1163 static int table_deps(struct dm_ioctl *param, size_t param_size) 1164 { 1165 int r = 0; 1166 struct mapped_device *md; 1167 struct dm_table *table; 1168 1169 md = find_device(param); 1170 if (!md) 1171 return -ENXIO; 1172 1173 r = __dev_status(md, param); 1174 if (r) 1175 goto out; 1176 1177 table = dm_get_table(md); 1178 if (table) { 1179 retrieve_deps(table, param, param_size); 1180 dm_table_put(table); 1181 } 1182 1183 out: 1184 dm_put(md); 1185 return r; 1186 } 1187 1188 /* 1189 * Return the status of a device as a text string for each 1190 * target. 1191 */ 1192 static int table_status(struct dm_ioctl *param, size_t param_size) 1193 { 1194 int r; 1195 struct mapped_device *md; 1196 struct dm_table *table; 1197 1198 md = find_device(param); 1199 if (!md) 1200 return -ENXIO; 1201 1202 r = __dev_status(md, param); 1203 if (r) 1204 goto out; 1205 1206 table = dm_get_table(md); 1207 if (table) { 1208 retrieve_status(table, param, param_size); 1209 dm_table_put(table); 1210 } 1211 1212 out: 1213 dm_put(md); 1214 return r; 1215 } 1216 1217 /* 1218 * Pass a message to the target that's at the supplied device offset. 1219 */ 1220 static int target_message(struct dm_ioctl *param, size_t param_size) 1221 { 1222 int r, argc; 1223 char **argv; 1224 struct mapped_device *md; 1225 struct dm_table *table; 1226 struct dm_target *ti; 1227 struct dm_target_msg *tmsg = (void *) param + param->data_start; 1228 1229 md = find_device(param); 1230 if (!md) 1231 return -ENXIO; 1232 1233 r = __dev_status(md, param); 1234 if (r) 1235 goto out; 1236 1237 if (tmsg < (struct dm_target_msg *) param->data || 1238 invalid_str(tmsg->message, (void *) param + param_size)) { 1239 DMWARN("Invalid target message parameters."); 1240 r = -EINVAL; 1241 goto out; 1242 } 1243 1244 r = dm_split_args(&argc, &argv, tmsg->message); 1245 if (r) { 1246 DMWARN("Failed to split target message parameters"); 1247 goto out; 1248 } 1249 1250 table = dm_get_table(md); 1251 if (!table) 1252 goto out_argv; 1253 1254 ti = dm_table_find_target(table, tmsg->sector); 1255 if (!dm_target_is_valid(ti)) { 1256 DMWARN("Target message sector outside device."); 1257 r = -EINVAL; 1258 } else if (ti->type->message) 1259 r = ti->type->message(ti, argc, argv); 1260 else { 1261 DMWARN("Target type does not support messages"); 1262 r = -EINVAL; 1263 } 1264 1265 dm_table_put(table); 1266 out_argv: 1267 kfree(argv); 1268 out: 1269 param->data_size = 0; 1270 dm_put(md); 1271 return r; 1272 } 1273 1274 /*----------------------------------------------------------------- 1275 * Implementation of open/close/ioctl on the special char 1276 * device. 1277 *---------------------------------------------------------------*/ 1278 static ioctl_fn lookup_ioctl(unsigned int cmd) 1279 { 1280 static struct { 1281 int cmd; 1282 ioctl_fn fn; 1283 } _ioctls[] = { 1284 {DM_VERSION_CMD, NULL}, /* version is dealt with elsewhere */ 1285 {DM_REMOVE_ALL_CMD, remove_all}, 1286 {DM_LIST_DEVICES_CMD, list_devices}, 1287 1288 {DM_DEV_CREATE_CMD, dev_create}, 1289 {DM_DEV_REMOVE_CMD, dev_remove}, 1290 {DM_DEV_RENAME_CMD, dev_rename}, 1291 {DM_DEV_SUSPEND_CMD, dev_suspend}, 1292 {DM_DEV_STATUS_CMD, dev_status}, 1293 {DM_DEV_WAIT_CMD, dev_wait}, 1294 1295 {DM_TABLE_LOAD_CMD, table_load}, 1296 {DM_TABLE_CLEAR_CMD, table_clear}, 1297 {DM_TABLE_DEPS_CMD, table_deps}, 1298 {DM_TABLE_STATUS_CMD, table_status}, 1299 1300 {DM_LIST_VERSIONS_CMD, list_versions}, 1301 1302 {DM_TARGET_MSG_CMD, target_message}, 1303 {DM_DEV_SET_GEOMETRY_CMD, dev_set_geometry} 1304 }; 1305 1306 return (cmd >= ARRAY_SIZE(_ioctls)) ? NULL : _ioctls[cmd].fn; 1307 } 1308 1309 /* 1310 * As well as checking the version compatibility this always 1311 * copies the kernel interface version out. 1312 */ 1313 static int check_version(unsigned int cmd, struct dm_ioctl __user *user) 1314 { 1315 uint32_t version[3]; 1316 int r = 0; 1317 1318 if (copy_from_user(version, user->version, sizeof(version))) 1319 return -EFAULT; 1320 1321 if ((DM_VERSION_MAJOR != version[0]) || 1322 (DM_VERSION_MINOR < version[1])) { 1323 DMWARN("ioctl interface mismatch: " 1324 "kernel(%u.%u.%u), user(%u.%u.%u), cmd(%d)", 1325 DM_VERSION_MAJOR, DM_VERSION_MINOR, 1326 DM_VERSION_PATCHLEVEL, 1327 version[0], version[1], version[2], cmd); 1328 r = -EINVAL; 1329 } 1330 1331 /* 1332 * Fill in the kernel version. 1333 */ 1334 version[0] = DM_VERSION_MAJOR; 1335 version[1] = DM_VERSION_MINOR; 1336 version[2] = DM_VERSION_PATCHLEVEL; 1337 if (copy_to_user(user->version, version, sizeof(version))) 1338 return -EFAULT; 1339 1340 return r; 1341 } 1342 1343 static void free_params(struct dm_ioctl *param) 1344 { 1345 vfree(param); 1346 } 1347 1348 static int copy_params(struct dm_ioctl __user *user, struct dm_ioctl **param) 1349 { 1350 struct dm_ioctl tmp, *dmi; 1351 1352 if (copy_from_user(&tmp, user, sizeof(tmp) - sizeof(tmp.data))) 1353 return -EFAULT; 1354 1355 if (tmp.data_size < (sizeof(tmp) - sizeof(tmp.data))) 1356 return -EINVAL; 1357 1358 dmi = vmalloc(tmp.data_size); 1359 if (!dmi) 1360 return -ENOMEM; 1361 1362 if (copy_from_user(dmi, user, tmp.data_size)) { 1363 vfree(dmi); 1364 return -EFAULT; 1365 } 1366 1367 *param = dmi; 1368 return 0; 1369 } 1370 1371 static int validate_params(uint cmd, struct dm_ioctl *param) 1372 { 1373 /* Always clear this flag */ 1374 param->flags &= ~DM_BUFFER_FULL_FLAG; 1375 1376 /* Ignores parameters */ 1377 if (cmd == DM_REMOVE_ALL_CMD || 1378 cmd == DM_LIST_DEVICES_CMD || 1379 cmd == DM_LIST_VERSIONS_CMD) 1380 return 0; 1381 1382 if ((cmd == DM_DEV_CREATE_CMD)) { 1383 if (!*param->name) { 1384 DMWARN("name not supplied when creating device"); 1385 return -EINVAL; 1386 } 1387 } else if ((*param->uuid && *param->name)) { 1388 DMWARN("only supply one of name or uuid, cmd(%u)", cmd); 1389 return -EINVAL; 1390 } 1391 1392 /* Ensure strings are terminated */ 1393 param->name[DM_NAME_LEN - 1] = '\0'; 1394 param->uuid[DM_UUID_LEN - 1] = '\0'; 1395 1396 return 0; 1397 } 1398 1399 static int ctl_ioctl(uint command, struct dm_ioctl __user *user) 1400 { 1401 int r = 0; 1402 unsigned int cmd; 1403 struct dm_ioctl *uninitialized_var(param); 1404 ioctl_fn fn = NULL; 1405 size_t param_size; 1406 1407 /* only root can play with this */ 1408 if (!capable(CAP_SYS_ADMIN)) 1409 return -EACCES; 1410 1411 if (_IOC_TYPE(command) != DM_IOCTL) 1412 return -ENOTTY; 1413 1414 cmd = _IOC_NR(command); 1415 1416 /* 1417 * Check the interface version passed in. This also 1418 * writes out the kernel's interface version. 1419 */ 1420 r = check_version(cmd, user); 1421 if (r) 1422 return r; 1423 1424 /* 1425 * Nothing more to do for the version command. 1426 */ 1427 if (cmd == DM_VERSION_CMD) 1428 return 0; 1429 1430 fn = lookup_ioctl(cmd); 1431 if (!fn) { 1432 DMWARN("dm_ctl_ioctl: unknown command 0x%x", command); 1433 return -ENOTTY; 1434 } 1435 1436 /* 1437 * Trying to avoid low memory issues when a device is 1438 * suspended. 1439 */ 1440 current->flags |= PF_MEMALLOC; 1441 1442 /* 1443 * Copy the parameters into kernel space. 1444 */ 1445 r = copy_params(user, ¶m); 1446 1447 current->flags &= ~PF_MEMALLOC; 1448 1449 if (r) 1450 return r; 1451 1452 r = validate_params(cmd, param); 1453 if (r) 1454 goto out; 1455 1456 param_size = param->data_size; 1457 param->data_size = sizeof(*param); 1458 r = fn(param, param_size); 1459 1460 /* 1461 * Copy the results back to userland. 1462 */ 1463 if (!r && copy_to_user(user, param, param->data_size)) 1464 r = -EFAULT; 1465 1466 out: 1467 free_params(param); 1468 return r; 1469 } 1470 1471 static long dm_ctl_ioctl(struct file *file, uint command, ulong u) 1472 { 1473 return (long)ctl_ioctl(command, (struct dm_ioctl __user *)u); 1474 } 1475 1476 #ifdef CONFIG_COMPAT 1477 static long dm_compat_ctl_ioctl(struct file *file, uint command, ulong u) 1478 { 1479 return (long)dm_ctl_ioctl(file, command, (ulong) compat_ptr(u)); 1480 } 1481 #else 1482 #define dm_compat_ctl_ioctl NULL 1483 #endif 1484 1485 static const struct file_operations _ctl_fops = { 1486 .unlocked_ioctl = dm_ctl_ioctl, 1487 .compat_ioctl = dm_compat_ctl_ioctl, 1488 .owner = THIS_MODULE, 1489 }; 1490 1491 static struct miscdevice _dm_misc = { 1492 .minor = MISC_DYNAMIC_MINOR, 1493 .name = DM_NAME, 1494 .fops = &_ctl_fops 1495 }; 1496 1497 /* 1498 * Create misc character device and link to DM_DIR/control. 1499 */ 1500 int __init dm_interface_init(void) 1501 { 1502 int r; 1503 1504 r = dm_hash_init(); 1505 if (r) 1506 return r; 1507 1508 r = misc_register(&_dm_misc); 1509 if (r) { 1510 DMERR("misc_register failed for control device"); 1511 dm_hash_exit(); 1512 return r; 1513 } 1514 1515 DMINFO("%d.%d.%d%s initialised: %s", DM_VERSION_MAJOR, 1516 DM_VERSION_MINOR, DM_VERSION_PATCHLEVEL, DM_VERSION_EXTRA, 1517 DM_DRIVER_EMAIL); 1518 return 0; 1519 } 1520 1521 void dm_interface_exit(void) 1522 { 1523 if (misc_deregister(&_dm_misc) < 0) 1524 DMERR("misc_deregister failed for control device"); 1525 1526 dm_hash_exit(); 1527 } 1528 1529 /** 1530 * dm_copy_name_and_uuid - Copy mapped device name & uuid into supplied buffers 1531 * @md: Pointer to mapped_device 1532 * @name: Buffer (size DM_NAME_LEN) for name 1533 * @uuid: Buffer (size DM_UUID_LEN) for uuid or empty string if uuid not defined 1534 */ 1535 int dm_copy_name_and_uuid(struct mapped_device *md, char *name, char *uuid) 1536 { 1537 int r = 0; 1538 struct hash_cell *hc; 1539 1540 if (!md) 1541 return -ENXIO; 1542 1543 dm_get(md); 1544 down_read(&_hash_lock); 1545 hc = dm_get_mdptr(md); 1546 if (!hc || hc->md != md) { 1547 r = -ENXIO; 1548 goto out; 1549 } 1550 1551 if (name) 1552 strcpy(name, hc->name); 1553 if (uuid) 1554 strcpy(uuid, hc->uuid ? : ""); 1555 1556 out: 1557 up_read(&_hash_lock); 1558 dm_put(md); 1559 1560 return r; 1561 } 1562