1 /* 2 * Copyright (C) 2001 Sistina Software (UK) Limited. 3 * Copyright (C) 2004 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/blkdev.h> 13 #include <linux/namei.h> 14 #include <linux/ctype.h> 15 #include <linux/slab.h> 16 #include <linux/interrupt.h> 17 #include <linux/mutex.h> 18 #include <asm/atomic.h> 19 20 #define DM_MSG_PREFIX "table" 21 22 #define MAX_DEPTH 16 23 #define NODE_SIZE L1_CACHE_BYTES 24 #define KEYS_PER_NODE (NODE_SIZE / sizeof(sector_t)) 25 #define CHILDREN_PER_NODE (KEYS_PER_NODE + 1) 26 27 struct dm_table { 28 struct mapped_device *md; 29 atomic_t holders; 30 31 /* btree table */ 32 unsigned int depth; 33 unsigned int counts[MAX_DEPTH]; /* in nodes */ 34 sector_t *index[MAX_DEPTH]; 35 36 unsigned int num_targets; 37 unsigned int num_allocated; 38 sector_t *highs; 39 struct dm_target *targets; 40 41 /* 42 * Indicates the rw permissions for the new logical 43 * device. This should be a combination of FMODE_READ 44 * and FMODE_WRITE. 45 */ 46 int mode; 47 48 /* a list of devices used by this table */ 49 struct list_head devices; 50 51 /* 52 * These are optimistic limits taken from all the 53 * targets, some targets will need smaller limits. 54 */ 55 struct io_restrictions limits; 56 57 /* events get handed up using this callback */ 58 void (*event_fn)(void *); 59 void *event_context; 60 }; 61 62 /* 63 * Similar to ceiling(log_size(n)) 64 */ 65 static unsigned int int_log(unsigned int n, unsigned int base) 66 { 67 int result = 0; 68 69 while (n > 1) { 70 n = dm_div_up(n, base); 71 result++; 72 } 73 74 return result; 75 } 76 77 /* 78 * Returns the minimum that is _not_ zero, unless both are zero. 79 */ 80 #define min_not_zero(l, r) (l == 0) ? r : ((r == 0) ? l : min(l, r)) 81 82 /* 83 * Combine two io_restrictions, always taking the lower value. 84 */ 85 static void combine_restrictions_low(struct io_restrictions *lhs, 86 struct io_restrictions *rhs) 87 { 88 lhs->max_sectors = 89 min_not_zero(lhs->max_sectors, rhs->max_sectors); 90 91 lhs->max_phys_segments = 92 min_not_zero(lhs->max_phys_segments, rhs->max_phys_segments); 93 94 lhs->max_hw_segments = 95 min_not_zero(lhs->max_hw_segments, rhs->max_hw_segments); 96 97 lhs->hardsect_size = max(lhs->hardsect_size, rhs->hardsect_size); 98 99 lhs->max_segment_size = 100 min_not_zero(lhs->max_segment_size, rhs->max_segment_size); 101 102 lhs->max_hw_sectors = 103 min_not_zero(lhs->max_hw_sectors, rhs->max_hw_sectors); 104 105 lhs->seg_boundary_mask = 106 min_not_zero(lhs->seg_boundary_mask, rhs->seg_boundary_mask); 107 108 lhs->bounce_pfn = min_not_zero(lhs->bounce_pfn, rhs->bounce_pfn); 109 110 lhs->no_cluster |= rhs->no_cluster; 111 } 112 113 /* 114 * Calculate the index of the child node of the n'th node k'th key. 115 */ 116 static inline unsigned int get_child(unsigned int n, unsigned int k) 117 { 118 return (n * CHILDREN_PER_NODE) + k; 119 } 120 121 /* 122 * Return the n'th node of level l from table t. 123 */ 124 static inline sector_t *get_node(struct dm_table *t, 125 unsigned int l, unsigned int n) 126 { 127 return t->index[l] + (n * KEYS_PER_NODE); 128 } 129 130 /* 131 * Return the highest key that you could lookup from the n'th 132 * node on level l of the btree. 133 */ 134 static sector_t high(struct dm_table *t, unsigned int l, unsigned int n) 135 { 136 for (; l < t->depth - 1; l++) 137 n = get_child(n, CHILDREN_PER_NODE - 1); 138 139 if (n >= t->counts[l]) 140 return (sector_t) - 1; 141 142 return get_node(t, l, n)[KEYS_PER_NODE - 1]; 143 } 144 145 /* 146 * Fills in a level of the btree based on the highs of the level 147 * below it. 148 */ 149 static int setup_btree_index(unsigned int l, struct dm_table *t) 150 { 151 unsigned int n, k; 152 sector_t *node; 153 154 for (n = 0U; n < t->counts[l]; n++) { 155 node = get_node(t, l, n); 156 157 for (k = 0U; k < KEYS_PER_NODE; k++) 158 node[k] = high(t, l + 1, get_child(n, k)); 159 } 160 161 return 0; 162 } 163 164 void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size) 165 { 166 unsigned long size; 167 void *addr; 168 169 /* 170 * Check that we're not going to overflow. 171 */ 172 if (nmemb > (ULONG_MAX / elem_size)) 173 return NULL; 174 175 size = nmemb * elem_size; 176 addr = vmalloc(size); 177 if (addr) 178 memset(addr, 0, size); 179 180 return addr; 181 } 182 183 /* 184 * highs, and targets are managed as dynamic arrays during a 185 * table load. 186 */ 187 static int alloc_targets(struct dm_table *t, unsigned int num) 188 { 189 sector_t *n_highs; 190 struct dm_target *n_targets; 191 int n = t->num_targets; 192 193 /* 194 * Allocate both the target array and offset array at once. 195 * Append an empty entry to catch sectors beyond the end of 196 * the device. 197 */ 198 n_highs = (sector_t *) dm_vcalloc(num + 1, sizeof(struct dm_target) + 199 sizeof(sector_t)); 200 if (!n_highs) 201 return -ENOMEM; 202 203 n_targets = (struct dm_target *) (n_highs + num); 204 205 if (n) { 206 memcpy(n_highs, t->highs, sizeof(*n_highs) * n); 207 memcpy(n_targets, t->targets, sizeof(*n_targets) * n); 208 } 209 210 memset(n_highs + n, -1, sizeof(*n_highs) * (num - n)); 211 vfree(t->highs); 212 213 t->num_allocated = num; 214 t->highs = n_highs; 215 t->targets = n_targets; 216 217 return 0; 218 } 219 220 int dm_table_create(struct dm_table **result, int mode, 221 unsigned num_targets, struct mapped_device *md) 222 { 223 struct dm_table *t = kzalloc(sizeof(*t), GFP_KERNEL); 224 225 if (!t) 226 return -ENOMEM; 227 228 INIT_LIST_HEAD(&t->devices); 229 atomic_set(&t->holders, 1); 230 231 if (!num_targets) 232 num_targets = KEYS_PER_NODE; 233 234 num_targets = dm_round_up(num_targets, KEYS_PER_NODE); 235 236 if (alloc_targets(t, num_targets)) { 237 kfree(t); 238 t = NULL; 239 return -ENOMEM; 240 } 241 242 t->mode = mode; 243 t->md = md; 244 *result = t; 245 return 0; 246 } 247 248 static void free_devices(struct list_head *devices) 249 { 250 struct list_head *tmp, *next; 251 252 list_for_each_safe(tmp, next, devices) { 253 struct dm_dev *dd = list_entry(tmp, struct dm_dev, list); 254 kfree(dd); 255 } 256 } 257 258 static void table_destroy(struct dm_table *t) 259 { 260 unsigned int i; 261 262 /* free the indexes (see dm_table_complete) */ 263 if (t->depth >= 2) 264 vfree(t->index[t->depth - 2]); 265 266 /* free the targets */ 267 for (i = 0; i < t->num_targets; i++) { 268 struct dm_target *tgt = t->targets + i; 269 270 if (tgt->type->dtr) 271 tgt->type->dtr(tgt); 272 273 dm_put_target_type(tgt->type); 274 } 275 276 vfree(t->highs); 277 278 /* free the device list */ 279 if (t->devices.next != &t->devices) { 280 DMWARN("devices still present during destroy: " 281 "dm_table_remove_device calls missing"); 282 283 free_devices(&t->devices); 284 } 285 286 kfree(t); 287 } 288 289 void dm_table_get(struct dm_table *t) 290 { 291 atomic_inc(&t->holders); 292 } 293 294 void dm_table_put(struct dm_table *t) 295 { 296 if (!t) 297 return; 298 299 if (atomic_dec_and_test(&t->holders)) 300 table_destroy(t); 301 } 302 303 /* 304 * Checks to see if we need to extend highs or targets. 305 */ 306 static inline int check_space(struct dm_table *t) 307 { 308 if (t->num_targets >= t->num_allocated) 309 return alloc_targets(t, t->num_allocated * 2); 310 311 return 0; 312 } 313 314 /* 315 * Convert a device path to a dev_t. 316 */ 317 static int lookup_device(const char *path, dev_t *dev) 318 { 319 struct block_device *bdev = lookup_bdev(path); 320 if (IS_ERR(bdev)) 321 return PTR_ERR(bdev); 322 *dev = bdev->bd_dev; 323 bdput(bdev); 324 return 0; 325 } 326 327 /* 328 * See if we've already got a device in the list. 329 */ 330 static struct dm_dev *find_device(struct list_head *l, dev_t dev) 331 { 332 struct dm_dev *dd; 333 334 list_for_each_entry (dd, l, list) 335 if (dd->bdev->bd_dev == dev) 336 return dd; 337 338 return NULL; 339 } 340 341 /* 342 * Open a device so we can use it as a map destination. 343 */ 344 static int open_dev(struct dm_dev *d, dev_t dev, struct mapped_device *md) 345 { 346 static char *_claim_ptr = "I belong to device-mapper"; 347 struct block_device *bdev; 348 349 int r; 350 351 BUG_ON(d->bdev); 352 353 bdev = open_by_devnum(dev, d->mode); 354 if (IS_ERR(bdev)) 355 return PTR_ERR(bdev); 356 r = bd_claim_by_disk(bdev, _claim_ptr, dm_disk(md)); 357 if (r) 358 blkdev_put(bdev); 359 else 360 d->bdev = bdev; 361 return r; 362 } 363 364 /* 365 * Close a device that we've been using. 366 */ 367 static void close_dev(struct dm_dev *d, struct mapped_device *md) 368 { 369 if (!d->bdev) 370 return; 371 372 bd_release_from_disk(d->bdev, dm_disk(md)); 373 blkdev_put(d->bdev); 374 d->bdev = NULL; 375 } 376 377 /* 378 * If possible, this checks an area of a destination device is valid. 379 */ 380 static int check_device_area(struct dm_dev *dd, sector_t start, sector_t len) 381 { 382 sector_t dev_size = dd->bdev->bd_inode->i_size >> SECTOR_SHIFT; 383 384 if (!dev_size) 385 return 1; 386 387 return ((start < dev_size) && (len <= (dev_size - start))); 388 } 389 390 /* 391 * This upgrades the mode on an already open dm_dev. Being 392 * careful to leave things as they were if we fail to reopen the 393 * device. 394 */ 395 static int upgrade_mode(struct dm_dev *dd, int new_mode, struct mapped_device *md) 396 { 397 int r; 398 struct dm_dev dd_copy; 399 dev_t dev = dd->bdev->bd_dev; 400 401 dd_copy = *dd; 402 403 dd->mode |= new_mode; 404 dd->bdev = NULL; 405 r = open_dev(dd, dev, md); 406 if (!r) 407 close_dev(&dd_copy, md); 408 else 409 *dd = dd_copy; 410 411 return r; 412 } 413 414 /* 415 * Add a device to the list, or just increment the usage count if 416 * it's already present. 417 */ 418 static int __table_get_device(struct dm_table *t, struct dm_target *ti, 419 const char *path, sector_t start, sector_t len, 420 int mode, struct dm_dev **result) 421 { 422 int r; 423 dev_t uninitialized_var(dev); 424 struct dm_dev *dd; 425 unsigned int major, minor; 426 427 BUG_ON(!t); 428 429 if (sscanf(path, "%u:%u", &major, &minor) == 2) { 430 /* Extract the major/minor numbers */ 431 dev = MKDEV(major, minor); 432 if (MAJOR(dev) != major || MINOR(dev) != minor) 433 return -EOVERFLOW; 434 } else { 435 /* convert the path to a device */ 436 if ((r = lookup_device(path, &dev))) 437 return r; 438 } 439 440 dd = find_device(&t->devices, dev); 441 if (!dd) { 442 dd = kmalloc(sizeof(*dd), GFP_KERNEL); 443 if (!dd) 444 return -ENOMEM; 445 446 dd->mode = mode; 447 dd->bdev = NULL; 448 449 if ((r = open_dev(dd, dev, t->md))) { 450 kfree(dd); 451 return r; 452 } 453 454 format_dev_t(dd->name, dev); 455 456 atomic_set(&dd->count, 0); 457 list_add(&dd->list, &t->devices); 458 459 } else if (dd->mode != (mode | dd->mode)) { 460 r = upgrade_mode(dd, mode, t->md); 461 if (r) 462 return r; 463 } 464 atomic_inc(&dd->count); 465 466 if (!check_device_area(dd, start, len)) { 467 DMWARN("device %s too small for target", path); 468 dm_put_device(ti, dd); 469 return -EINVAL; 470 } 471 472 *result = dd; 473 474 return 0; 475 } 476 477 void dm_set_device_limits(struct dm_target *ti, struct block_device *bdev) 478 { 479 struct request_queue *q = bdev_get_queue(bdev); 480 struct io_restrictions *rs = &ti->limits; 481 482 /* 483 * Combine the device limits low. 484 * 485 * FIXME: if we move an io_restriction struct 486 * into q this would just be a call to 487 * combine_restrictions_low() 488 */ 489 rs->max_sectors = 490 min_not_zero(rs->max_sectors, q->max_sectors); 491 492 /* 493 * Check if merge fn is supported. 494 * If not we'll force DM to use PAGE_SIZE or 495 * smaller I/O, just to be safe. 496 */ 497 498 if (q->merge_bvec_fn && !ti->type->merge) 499 rs->max_sectors = 500 min_not_zero(rs->max_sectors, 501 (unsigned int) (PAGE_SIZE >> 9)); 502 503 rs->max_phys_segments = 504 min_not_zero(rs->max_phys_segments, 505 q->max_phys_segments); 506 507 rs->max_hw_segments = 508 min_not_zero(rs->max_hw_segments, q->max_hw_segments); 509 510 rs->hardsect_size = max(rs->hardsect_size, q->hardsect_size); 511 512 rs->max_segment_size = 513 min_not_zero(rs->max_segment_size, q->max_segment_size); 514 515 rs->max_hw_sectors = 516 min_not_zero(rs->max_hw_sectors, q->max_hw_sectors); 517 518 rs->seg_boundary_mask = 519 min_not_zero(rs->seg_boundary_mask, 520 q->seg_boundary_mask); 521 522 rs->bounce_pfn = min_not_zero(rs->bounce_pfn, q->bounce_pfn); 523 524 rs->no_cluster |= !test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags); 525 } 526 EXPORT_SYMBOL_GPL(dm_set_device_limits); 527 528 int dm_get_device(struct dm_target *ti, const char *path, sector_t start, 529 sector_t len, int mode, struct dm_dev **result) 530 { 531 int r = __table_get_device(ti->table, ti, path, 532 start, len, mode, result); 533 534 if (!r) 535 dm_set_device_limits(ti, (*result)->bdev); 536 537 return r; 538 } 539 540 /* 541 * Decrement a devices use count and remove it if necessary. 542 */ 543 void dm_put_device(struct dm_target *ti, struct dm_dev *dd) 544 { 545 if (atomic_dec_and_test(&dd->count)) { 546 close_dev(dd, ti->table->md); 547 list_del(&dd->list); 548 kfree(dd); 549 } 550 } 551 552 /* 553 * Checks to see if the target joins onto the end of the table. 554 */ 555 static int adjoin(struct dm_table *table, struct dm_target *ti) 556 { 557 struct dm_target *prev; 558 559 if (!table->num_targets) 560 return !ti->begin; 561 562 prev = &table->targets[table->num_targets - 1]; 563 return (ti->begin == (prev->begin + prev->len)); 564 } 565 566 /* 567 * Used to dynamically allocate the arg array. 568 */ 569 static char **realloc_argv(unsigned *array_size, char **old_argv) 570 { 571 char **argv; 572 unsigned new_size; 573 574 new_size = *array_size ? *array_size * 2 : 64; 575 argv = kmalloc(new_size * sizeof(*argv), GFP_KERNEL); 576 if (argv) { 577 memcpy(argv, old_argv, *array_size * sizeof(*argv)); 578 *array_size = new_size; 579 } 580 581 kfree(old_argv); 582 return argv; 583 } 584 585 /* 586 * Destructively splits up the argument list to pass to ctr. 587 */ 588 int dm_split_args(int *argc, char ***argvp, char *input) 589 { 590 char *start, *end = input, *out, **argv = NULL; 591 unsigned array_size = 0; 592 593 *argc = 0; 594 595 if (!input) { 596 *argvp = NULL; 597 return 0; 598 } 599 600 argv = realloc_argv(&array_size, argv); 601 if (!argv) 602 return -ENOMEM; 603 604 while (1) { 605 start = end; 606 607 /* Skip whitespace */ 608 while (*start && isspace(*start)) 609 start++; 610 611 if (!*start) 612 break; /* success, we hit the end */ 613 614 /* 'out' is used to remove any back-quotes */ 615 end = out = start; 616 while (*end) { 617 /* Everything apart from '\0' can be quoted */ 618 if (*end == '\\' && *(end + 1)) { 619 *out++ = *(end + 1); 620 end += 2; 621 continue; 622 } 623 624 if (isspace(*end)) 625 break; /* end of token */ 626 627 *out++ = *end++; 628 } 629 630 /* have we already filled the array ? */ 631 if ((*argc + 1) > array_size) { 632 argv = realloc_argv(&array_size, argv); 633 if (!argv) 634 return -ENOMEM; 635 } 636 637 /* we know this is whitespace */ 638 if (*end) 639 end++; 640 641 /* terminate the string and put it in the array */ 642 *out = '\0'; 643 argv[*argc] = start; 644 (*argc)++; 645 } 646 647 *argvp = argv; 648 return 0; 649 } 650 651 static void check_for_valid_limits(struct io_restrictions *rs) 652 { 653 if (!rs->max_sectors) 654 rs->max_sectors = SAFE_MAX_SECTORS; 655 if (!rs->max_hw_sectors) 656 rs->max_hw_sectors = SAFE_MAX_SECTORS; 657 if (!rs->max_phys_segments) 658 rs->max_phys_segments = MAX_PHYS_SEGMENTS; 659 if (!rs->max_hw_segments) 660 rs->max_hw_segments = MAX_HW_SEGMENTS; 661 if (!rs->hardsect_size) 662 rs->hardsect_size = 1 << SECTOR_SHIFT; 663 if (!rs->max_segment_size) 664 rs->max_segment_size = MAX_SEGMENT_SIZE; 665 if (!rs->seg_boundary_mask) 666 rs->seg_boundary_mask = -1; 667 if (!rs->bounce_pfn) 668 rs->bounce_pfn = -1; 669 } 670 671 int dm_table_add_target(struct dm_table *t, const char *type, 672 sector_t start, sector_t len, char *params) 673 { 674 int r = -EINVAL, argc; 675 char **argv; 676 struct dm_target *tgt; 677 678 if ((r = check_space(t))) 679 return r; 680 681 tgt = t->targets + t->num_targets; 682 memset(tgt, 0, sizeof(*tgt)); 683 684 if (!len) { 685 DMERR("%s: zero-length target", dm_device_name(t->md)); 686 return -EINVAL; 687 } 688 689 tgt->type = dm_get_target_type(type); 690 if (!tgt->type) { 691 DMERR("%s: %s: unknown target type", dm_device_name(t->md), 692 type); 693 return -EINVAL; 694 } 695 696 tgt->table = t; 697 tgt->begin = start; 698 tgt->len = len; 699 tgt->error = "Unknown error"; 700 701 /* 702 * Does this target adjoin the previous one ? 703 */ 704 if (!adjoin(t, tgt)) { 705 tgt->error = "Gap in table"; 706 r = -EINVAL; 707 goto bad; 708 } 709 710 r = dm_split_args(&argc, &argv, params); 711 if (r) { 712 tgt->error = "couldn't split parameters (insufficient memory)"; 713 goto bad; 714 } 715 716 r = tgt->type->ctr(tgt, argc, argv); 717 kfree(argv); 718 if (r) 719 goto bad; 720 721 t->highs[t->num_targets++] = tgt->begin + tgt->len - 1; 722 723 /* FIXME: the plan is to combine high here and then have 724 * the merge fn apply the target level restrictions. */ 725 combine_restrictions_low(&t->limits, &tgt->limits); 726 return 0; 727 728 bad: 729 DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error); 730 dm_put_target_type(tgt->type); 731 return r; 732 } 733 734 static int setup_indexes(struct dm_table *t) 735 { 736 int i; 737 unsigned int total = 0; 738 sector_t *indexes; 739 740 /* allocate the space for *all* the indexes */ 741 for (i = t->depth - 2; i >= 0; i--) { 742 t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE); 743 total += t->counts[i]; 744 } 745 746 indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE); 747 if (!indexes) 748 return -ENOMEM; 749 750 /* set up internal nodes, bottom-up */ 751 for (i = t->depth - 2; i >= 0; i--) { 752 t->index[i] = indexes; 753 indexes += (KEYS_PER_NODE * t->counts[i]); 754 setup_btree_index(i, t); 755 } 756 757 return 0; 758 } 759 760 /* 761 * Builds the btree to index the map. 762 */ 763 int dm_table_complete(struct dm_table *t) 764 { 765 int r = 0; 766 unsigned int leaf_nodes; 767 768 check_for_valid_limits(&t->limits); 769 770 /* how many indexes will the btree have ? */ 771 leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE); 772 t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE); 773 774 /* leaf layer has already been set up */ 775 t->counts[t->depth - 1] = leaf_nodes; 776 t->index[t->depth - 1] = t->highs; 777 778 if (t->depth >= 2) 779 r = setup_indexes(t); 780 781 return r; 782 } 783 784 static DEFINE_MUTEX(_event_lock); 785 void dm_table_event_callback(struct dm_table *t, 786 void (*fn)(void *), void *context) 787 { 788 mutex_lock(&_event_lock); 789 t->event_fn = fn; 790 t->event_context = context; 791 mutex_unlock(&_event_lock); 792 } 793 794 void dm_table_event(struct dm_table *t) 795 { 796 /* 797 * You can no longer call dm_table_event() from interrupt 798 * context, use a bottom half instead. 799 */ 800 BUG_ON(in_interrupt()); 801 802 mutex_lock(&_event_lock); 803 if (t->event_fn) 804 t->event_fn(t->event_context); 805 mutex_unlock(&_event_lock); 806 } 807 808 sector_t dm_table_get_size(struct dm_table *t) 809 { 810 return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0; 811 } 812 813 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index) 814 { 815 if (index >= t->num_targets) 816 return NULL; 817 818 return t->targets + index; 819 } 820 821 /* 822 * Search the btree for the correct target. 823 * 824 * Caller should check returned pointer with dm_target_is_valid() 825 * to trap I/O beyond end of device. 826 */ 827 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector) 828 { 829 unsigned int l, n = 0, k = 0; 830 sector_t *node; 831 832 for (l = 0; l < t->depth; l++) { 833 n = get_child(n, k); 834 node = get_node(t, l, n); 835 836 for (k = 0; k < KEYS_PER_NODE; k++) 837 if (node[k] >= sector) 838 break; 839 } 840 841 return &t->targets[(KEYS_PER_NODE * n) + k]; 842 } 843 844 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q) 845 { 846 /* 847 * Make sure we obey the optimistic sub devices 848 * restrictions. 849 */ 850 blk_queue_max_sectors(q, t->limits.max_sectors); 851 q->max_phys_segments = t->limits.max_phys_segments; 852 q->max_hw_segments = t->limits.max_hw_segments; 853 q->hardsect_size = t->limits.hardsect_size; 854 q->max_segment_size = t->limits.max_segment_size; 855 q->max_hw_sectors = t->limits.max_hw_sectors; 856 q->seg_boundary_mask = t->limits.seg_boundary_mask; 857 q->bounce_pfn = t->limits.bounce_pfn; 858 859 if (t->limits.no_cluster) 860 queue_flag_clear_unlocked(QUEUE_FLAG_CLUSTER, q); 861 else 862 queue_flag_set_unlocked(QUEUE_FLAG_CLUSTER, q); 863 864 } 865 866 unsigned int dm_table_get_num_targets(struct dm_table *t) 867 { 868 return t->num_targets; 869 } 870 871 struct list_head *dm_table_get_devices(struct dm_table *t) 872 { 873 return &t->devices; 874 } 875 876 int dm_table_get_mode(struct dm_table *t) 877 { 878 return t->mode; 879 } 880 881 static void suspend_targets(struct dm_table *t, unsigned postsuspend) 882 { 883 int i = t->num_targets; 884 struct dm_target *ti = t->targets; 885 886 while (i--) { 887 if (postsuspend) { 888 if (ti->type->postsuspend) 889 ti->type->postsuspend(ti); 890 } else if (ti->type->presuspend) 891 ti->type->presuspend(ti); 892 893 ti++; 894 } 895 } 896 897 void dm_table_presuspend_targets(struct dm_table *t) 898 { 899 if (!t) 900 return; 901 902 suspend_targets(t, 0); 903 } 904 905 void dm_table_postsuspend_targets(struct dm_table *t) 906 { 907 if (!t) 908 return; 909 910 suspend_targets(t, 1); 911 } 912 913 int dm_table_resume_targets(struct dm_table *t) 914 { 915 int i, r = 0; 916 917 for (i = 0; i < t->num_targets; i++) { 918 struct dm_target *ti = t->targets + i; 919 920 if (!ti->type->preresume) 921 continue; 922 923 r = ti->type->preresume(ti); 924 if (r) 925 return r; 926 } 927 928 for (i = 0; i < t->num_targets; i++) { 929 struct dm_target *ti = t->targets + i; 930 931 if (ti->type->resume) 932 ti->type->resume(ti); 933 } 934 935 return 0; 936 } 937 938 int dm_table_any_congested(struct dm_table *t, int bdi_bits) 939 { 940 struct dm_dev *dd; 941 struct list_head *devices = dm_table_get_devices(t); 942 int r = 0; 943 944 list_for_each_entry(dd, devices, list) { 945 struct request_queue *q = bdev_get_queue(dd->bdev); 946 r |= bdi_congested(&q->backing_dev_info, bdi_bits); 947 } 948 949 return r; 950 } 951 952 void dm_table_unplug_all(struct dm_table *t) 953 { 954 struct dm_dev *dd; 955 struct list_head *devices = dm_table_get_devices(t); 956 957 list_for_each_entry(dd, devices, list) { 958 struct request_queue *q = bdev_get_queue(dd->bdev); 959 960 blk_unplug(q); 961 } 962 } 963 964 struct mapped_device *dm_table_get_md(struct dm_table *t) 965 { 966 dm_get(t->md); 967 968 return t->md; 969 } 970 971 EXPORT_SYMBOL(dm_vcalloc); 972 EXPORT_SYMBOL(dm_get_device); 973 EXPORT_SYMBOL(dm_put_device); 974 EXPORT_SYMBOL(dm_table_event); 975 EXPORT_SYMBOL(dm_table_get_size); 976 EXPORT_SYMBOL(dm_table_get_mode); 977 EXPORT_SYMBOL(dm_table_get_md); 978 EXPORT_SYMBOL(dm_table_put); 979 EXPORT_SYMBOL(dm_table_get); 980 EXPORT_SYMBOL(dm_table_unplug_all); 981