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 27struct 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 */ 65static 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 */ 85static 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->seg_boundary_mask = 103 min_not_zero(lhs->seg_boundary_mask, rhs->seg_boundary_mask); 104 105 lhs->no_cluster |= rhs->no_cluster; 106} 107 108/* 109 * Calculate the index of the child node of the n'th node k'th key. 110 */ 111static inline unsigned int get_child(unsigned int n, unsigned int k) 112{ 113 return (n * CHILDREN_PER_NODE) + k; 114} 115 116/* 117 * Return the n'th node of level l from table t. 118 */ 119static inline sector_t *get_node(struct dm_table *t, 120 unsigned int l, unsigned int n) 121{ 122 return t->index[l] + (n * KEYS_PER_NODE); 123} 124 125/* 126 * Return the highest key that you could lookup from the n'th 127 * node on level l of the btree. 128 */ 129static sector_t high(struct dm_table *t, unsigned int l, unsigned int n) 130{ 131 for (; l < t->depth - 1; l++) 132 n = get_child(n, CHILDREN_PER_NODE - 1); 133 134 if (n >= t->counts[l]) 135 return (sector_t) - 1; 136 137 return get_node(t, l, n)[KEYS_PER_NODE - 1]; 138} 139 140/* 141 * Fills in a level of the btree based on the highs of the level 142 * below it. 143 */ 144static int setup_btree_index(unsigned int l, struct dm_table *t) 145{ 146 unsigned int n, k; 147 sector_t *node; 148 149 for (n = 0U; n < t->counts[l]; n++) { 150 node = get_node(t, l, n); 151 152 for (k = 0U; k < KEYS_PER_NODE; k++) 153 node[k] = high(t, l + 1, get_child(n, k)); 154 } 155 156 return 0; 157} 158 159void *dm_vcalloc(unsigned long nmemb, unsigned long elem_size) 160{ 161 unsigned long size; 162 void *addr; 163 164 /* 165 * Check that we're not going to overflow. 166 */ 167 if (nmemb > (ULONG_MAX / elem_size)) 168 return NULL; 169 170 size = nmemb * elem_size; 171 addr = vmalloc(size); 172 if (addr) 173 memset(addr, 0, size); 174 175 return addr; 176} 177 178/* 179 * highs, and targets are managed as dynamic arrays during a 180 * table load. 181 */ 182static int alloc_targets(struct dm_table *t, unsigned int num) 183{ 184 sector_t *n_highs; 185 struct dm_target *n_targets; 186 int n = t->num_targets; 187 188 /* 189 * Allocate both the target array and offset array at once. 190 */ 191 n_highs = (sector_t *) dm_vcalloc(num, sizeof(struct dm_target) + 192 sizeof(sector_t)); 193 if (!n_highs) 194 return -ENOMEM; 195 196 n_targets = (struct dm_target *) (n_highs + num); 197 198 if (n) { 199 memcpy(n_highs, t->highs, sizeof(*n_highs) * n); 200 memcpy(n_targets, t->targets, sizeof(*n_targets) * n); 201 } 202 203 memset(n_highs + n, -1, sizeof(*n_highs) * (num - n)); 204 vfree(t->highs); 205 206 t->num_allocated = num; 207 t->highs = n_highs; 208 t->targets = n_targets; 209 210 return 0; 211} 212 213int dm_table_create(struct dm_table **result, int mode, 214 unsigned num_targets, struct mapped_device *md) 215{ 216 struct dm_table *t = kmalloc(sizeof(*t), GFP_KERNEL); 217 218 if (!t) 219 return -ENOMEM; 220 221 memset(t, 0, sizeof(*t)); 222 INIT_LIST_HEAD(&t->devices); 223 atomic_set(&t->holders, 1); 224 225 if (!num_targets) 226 num_targets = KEYS_PER_NODE; 227 228 num_targets = dm_round_up(num_targets, KEYS_PER_NODE); 229 230 if (alloc_targets(t, num_targets)) { 231 kfree(t); 232 t = NULL; 233 return -ENOMEM; 234 } 235 236 t->mode = mode; 237 t->md = md; 238 *result = t; 239 return 0; 240} 241 242int dm_create_error_table(struct dm_table **result, struct mapped_device *md) 243{ 244 struct dm_table *t; 245 sector_t dev_size = 1; 246 int r; 247 248 /* 249 * Find current size of device. 250 * Default to 1 sector if inactive. 251 */ 252 t = dm_get_table(md); 253 if (t) { 254 dev_size = dm_table_get_size(t); 255 dm_table_put(t); 256 } 257 258 r = dm_table_create(&t, FMODE_READ, 1, md); 259 if (r) 260 return r; 261 262 r = dm_table_add_target(t, "error", 0, dev_size, NULL); 263 if (r) 264 goto out; 265 266 r = dm_table_complete(t); 267 if (r) 268 goto out; 269 270 *result = t; 271 272out: 273 if (r) 274 dm_table_put(t); 275 276 return r; 277} 278EXPORT_SYMBOL_GPL(dm_create_error_table); 279 280static void free_devices(struct list_head *devices) 281{ 282 struct list_head *tmp, *next; 283 284 for (tmp = devices->next; tmp != devices; tmp = next) { 285 struct dm_dev *dd = list_entry(tmp, struct dm_dev, list); 286 next = tmp->next; 287 kfree(dd); 288 } 289} 290 291static void table_destroy(struct dm_table *t) 292{ 293 unsigned int i; 294 295 /* free the indexes (see dm_table_complete) */ 296 if (t->depth >= 2) 297 vfree(t->index[t->depth - 2]); 298 299 /* free the targets */ 300 for (i = 0; i < t->num_targets; i++) { 301 struct dm_target *tgt = t->targets + i; 302 303 if (tgt->type->dtr) 304 tgt->type->dtr(tgt); 305 306 dm_put_target_type(tgt->type); 307 } 308 309 vfree(t->highs); 310 311 /* free the device list */ 312 if (t->devices.next != &t->devices) { 313 DMWARN("devices still present during destroy: " 314 "dm_table_remove_device calls missing"); 315 316 free_devices(&t->devices); 317 } 318 319 kfree(t); 320} 321 322void dm_table_get(struct dm_table *t) 323{ 324 atomic_inc(&t->holders); 325} 326 327void dm_table_put(struct dm_table *t) 328{ 329 if (!t) 330 return; 331 332 if (atomic_dec_and_test(&t->holders)) 333 table_destroy(t); 334} 335 336/* 337 * Checks to see if we need to extend highs or targets. 338 */ 339static inline int check_space(struct dm_table *t) 340{ 341 if (t->num_targets >= t->num_allocated) 342 return alloc_targets(t, t->num_allocated * 2); 343 344 return 0; 345} 346 347/* 348 * Convert a device path to a dev_t. 349 */ 350static int lookup_device(const char *path, dev_t *dev) 351{ 352 int r; 353 struct nameidata nd; 354 struct inode *inode; 355 356 if ((r = path_lookup(path, LOOKUP_FOLLOW, &nd))) 357 return r; 358 359 inode = nd.dentry->d_inode; 360 if (!inode) { 361 r = -ENOENT; 362 goto out; 363 } 364 365 if (!S_ISBLK(inode->i_mode)) { 366 r = -ENOTBLK; 367 goto out; 368 } 369 370 *dev = inode->i_rdev; 371 372 out: 373 path_release(&nd); 374 return r; 375} 376 377/* 378 * See if we've already got a device in the list. 379 */ 380static struct dm_dev *find_device(struct list_head *l, dev_t dev) 381{ 382 struct dm_dev *dd; 383 384 list_for_each_entry (dd, l, list) 385 if (dd->bdev->bd_dev == dev) 386 return dd; 387 388 return NULL; 389} 390 391/* 392 * Open a device so we can use it as a map destination. 393 */ 394static int open_dev(struct dm_dev *d, dev_t dev, struct mapped_device *md) 395{ 396 static char *_claim_ptr = "I belong to device-mapper"; 397 struct block_device *bdev; 398 399 int r; 400 401 BUG_ON(d->bdev); 402 403 bdev = open_by_devnum(dev, d->mode); 404 if (IS_ERR(bdev)) 405 return PTR_ERR(bdev); 406 r = bd_claim_by_disk(bdev, _claim_ptr, dm_disk(md)); 407 if (r) 408 blkdev_put(bdev); 409 else 410 d->bdev = bdev; 411 return r; 412} 413 414/* 415 * Close a device that we've been using. 416 */ 417static void close_dev(struct dm_dev *d, struct mapped_device *md) 418{ 419 if (!d->bdev) 420 return; 421 422 bd_release_from_disk(d->bdev, dm_disk(md)); 423 blkdev_put(d->bdev); 424 d->bdev = NULL; 425} 426 427/* 428 * If possible, this checks an area of a destination device is valid. 429 */ 430static int check_device_area(struct dm_dev *dd, sector_t start, sector_t len) 431{ 432 sector_t dev_size = dd->bdev->bd_inode->i_size >> SECTOR_SHIFT; 433 434 if (!dev_size) 435 return 1; 436 437 return ((start < dev_size) && (len <= (dev_size - start))); 438} 439 440/* 441 * This upgrades the mode on an already open dm_dev. Being 442 * careful to leave things as they were if we fail to reopen the 443 * device. 444 */ 445static int upgrade_mode(struct dm_dev *dd, int new_mode, struct mapped_device *md) 446{ 447 int r; 448 struct dm_dev dd_copy; 449 dev_t dev = dd->bdev->bd_dev; 450 451 dd_copy = *dd; 452 453 dd->mode |= new_mode; 454 dd->bdev = NULL; 455 r = open_dev(dd, dev, md); 456 if (!r) 457 close_dev(&dd_copy, md); 458 else 459 *dd = dd_copy; 460 461 return r; 462} 463 464/* 465 * Add a device to the list, or just increment the usage count if 466 * it's already present. 467 */ 468static int __table_get_device(struct dm_table *t, struct dm_target *ti, 469 const char *path, sector_t start, sector_t len, 470 int mode, struct dm_dev **result) 471{ 472 int r; 473 dev_t dev; 474 struct dm_dev *dd; 475 unsigned int major, minor; 476 477 BUG_ON(!t); 478 479 if (sscanf(path, "%u:%u", &major, &minor) == 2) { 480 /* Extract the major/minor numbers */ 481 dev = MKDEV(major, minor); 482 if (MAJOR(dev) != major || MINOR(dev) != minor) 483 return -EOVERFLOW; 484 } else { 485 /* convert the path to a device */ 486 if ((r = lookup_device(path, &dev))) 487 return r; 488 } 489 490 dd = find_device(&t->devices, dev); 491 if (!dd) { 492 dd = kmalloc(sizeof(*dd), GFP_KERNEL); 493 if (!dd) 494 return -ENOMEM; 495 496 dd->mode = mode; 497 dd->bdev = NULL; 498 499 if ((r = open_dev(dd, dev, t->md))) { 500 kfree(dd); 501 return r; 502 } 503 504 format_dev_t(dd->name, dev); 505 506 atomic_set(&dd->count, 0); 507 list_add(&dd->list, &t->devices); 508 509 } else if (dd->mode != (mode | dd->mode)) { 510 r = upgrade_mode(dd, mode, t->md); 511 if (r) 512 return r; 513 } 514 atomic_inc(&dd->count); 515 516 if (!check_device_area(dd, start, len)) { 517 DMWARN("device %s too small for target", path); 518 dm_put_device(ti, dd); 519 return -EINVAL; 520 } 521 522 *result = dd; 523 524 return 0; 525} 526 527void dm_set_device_limits(struct dm_target *ti, struct block_device *bdev) 528{ 529 request_queue_t *q = bdev_get_queue(bdev); 530 struct io_restrictions *rs = &ti->limits; 531 532 rs->max_sectors = 533 min_not_zero(rs->max_sectors, q->max_sectors); 534 535 if (q->merge_bvec_fn) 536 rs->max_sectors = 537 min_not_zero(rs->max_sectors, 538 (unsigned int) (PAGE_SIZE >> 9)); 539 540 rs->max_phys_segments = 541 min_not_zero(rs->max_phys_segments, 542 q->max_phys_segments); 543 544 rs->max_hw_segments = 545 min_not_zero(rs->max_hw_segments, q->max_hw_segments); 546 547 rs->hardsect_size = max(rs->hardsect_size, q->hardsect_size); 548 549 rs->max_segment_size = 550 min_not_zero(rs->max_segment_size, q->max_segment_size); 551 552 rs->seg_boundary_mask = 553 min_not_zero(rs->seg_boundary_mask, 554 q->seg_boundary_mask); 555 556 rs->no_cluster |= !test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags); 557} 558EXPORT_SYMBOL_GPL(dm_set_device_limits); 559 560int dm_get_device(struct dm_target *ti, const char *path, sector_t start, 561 sector_t len, int mode, struct dm_dev **result) 562{ 563 int r = __table_get_device(ti->table, ti, path, 564 start, len, mode, result); 565 566 if (!r) 567 dm_set_device_limits(ti, (*result)->bdev); 568 569 return r; 570} 571 572/* 573 * Decrement a devices use count and remove it if necessary. 574 */ 575void dm_put_device(struct dm_target *ti, struct dm_dev *dd) 576{ 577 if (atomic_dec_and_test(&dd->count)) { 578 close_dev(dd, ti->table->md); 579 list_del(&dd->list); 580 kfree(dd); 581 } 582} 583 584/* 585 * Checks to see if the target joins onto the end of the table. 586 */ 587static int adjoin(struct dm_table *table, struct dm_target *ti) 588{ 589 struct dm_target *prev; 590 591 if (!table->num_targets) 592 return !ti->begin; 593 594 prev = &table->targets[table->num_targets - 1]; 595 return (ti->begin == (prev->begin + prev->len)); 596} 597 598/* 599 * Used to dynamically allocate the arg array. 600 */ 601static char **realloc_argv(unsigned *array_size, char **old_argv) 602{ 603 char **argv; 604 unsigned new_size; 605 606 new_size = *array_size ? *array_size * 2 : 64; 607 argv = kmalloc(new_size * sizeof(*argv), GFP_KERNEL); 608 if (argv) { 609 memcpy(argv, old_argv, *array_size * sizeof(*argv)); 610 *array_size = new_size; 611 } 612 613 kfree(old_argv); 614 return argv; 615} 616 617/* 618 * Destructively splits up the argument list to pass to ctr. 619 */ 620int dm_split_args(int *argc, char ***argvp, char *input) 621{ 622 char *start, *end = input, *out, **argv = NULL; 623 unsigned array_size = 0; 624 625 *argc = 0; 626 627 if (!input) { 628 *argvp = NULL; 629 return 0; 630 } 631 632 argv = realloc_argv(&array_size, argv); 633 if (!argv) 634 return -ENOMEM; 635 636 while (1) { 637 start = end; 638 639 /* Skip whitespace */ 640 while (*start && isspace(*start)) 641 start++; 642 643 if (!*start) 644 break; /* success, we hit the end */ 645 646 /* 'out' is used to remove any back-quotes */ 647 end = out = start; 648 while (*end) { 649 /* Everything apart from '\0' can be quoted */ 650 if (*end == '\\' && *(end + 1)) { 651 *out++ = *(end + 1); 652 end += 2; 653 continue; 654 } 655 656 if (isspace(*end)) 657 break; /* end of token */ 658 659 *out++ = *end++; 660 } 661 662 /* have we already filled the array ? */ 663 if ((*argc + 1) > array_size) { 664 argv = realloc_argv(&array_size, argv); 665 if (!argv) 666 return -ENOMEM; 667 } 668 669 /* we know this is whitespace */ 670 if (*end) 671 end++; 672 673 /* terminate the string and put it in the array */ 674 *out = '\0'; 675 argv[*argc] = start; 676 (*argc)++; 677 } 678 679 *argvp = argv; 680 return 0; 681} 682 683static void check_for_valid_limits(struct io_restrictions *rs) 684{ 685 if (!rs->max_sectors) 686 rs->max_sectors = SAFE_MAX_SECTORS; 687 if (!rs->max_phys_segments) 688 rs->max_phys_segments = MAX_PHYS_SEGMENTS; 689 if (!rs->max_hw_segments) 690 rs->max_hw_segments = MAX_HW_SEGMENTS; 691 if (!rs->hardsect_size) 692 rs->hardsect_size = 1 << SECTOR_SHIFT; 693 if (!rs->max_segment_size) 694 rs->max_segment_size = MAX_SEGMENT_SIZE; 695 if (!rs->seg_boundary_mask) 696 rs->seg_boundary_mask = -1; 697} 698 699int dm_table_add_target(struct dm_table *t, const char *type, 700 sector_t start, sector_t len, char *params) 701{ 702 int r = -EINVAL, argc; 703 char **argv; 704 struct dm_target *tgt; 705 706 if ((r = check_space(t))) 707 return r; 708 709 tgt = t->targets + t->num_targets; 710 memset(tgt, 0, sizeof(*tgt)); 711 712 if (!len) { 713 DMERR("%s: zero-length target", dm_device_name(t->md)); 714 return -EINVAL; 715 } 716 717 tgt->type = dm_get_target_type(type); 718 if (!tgt->type) { 719 DMERR("%s: %s: unknown target type", dm_device_name(t->md), 720 type); 721 return -EINVAL; 722 } 723 724 tgt->table = t; 725 tgt->begin = start; 726 tgt->len = len; 727 tgt->error = "Unknown error"; 728 729 /* 730 * Does this target adjoin the previous one ? 731 */ 732 if (!adjoin(t, tgt)) { 733 tgt->error = "Gap in table"; 734 r = -EINVAL; 735 goto bad; 736 } 737 738 r = dm_split_args(&argc, &argv, params); 739 if (r) { 740 tgt->error = "couldn't split parameters (insufficient memory)"; 741 goto bad; 742 } 743 744 r = tgt->type->ctr(tgt, argc, argv); 745 kfree(argv); 746 if (r) 747 goto bad; 748 749 t->highs[t->num_targets++] = tgt->begin + tgt->len - 1; 750 751 combine_restrictions_low(&t->limits, &tgt->limits); 752 return 0; 753 754 bad: 755 DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error); 756 dm_put_target_type(tgt->type); 757 return r; 758} 759 760static int setup_indexes(struct dm_table *t) 761{ 762 int i; 763 unsigned int total = 0; 764 sector_t *indexes; 765 766 /* allocate the space for *all* the indexes */ 767 for (i = t->depth - 2; i >= 0; i--) { 768 t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE); 769 total += t->counts[i]; 770 } 771 772 indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE); 773 if (!indexes) 774 return -ENOMEM; 775 776 /* set up internal nodes, bottom-up */ 777 for (i = t->depth - 2, total = 0; i >= 0; i--) { 778 t->index[i] = indexes; 779 indexes += (KEYS_PER_NODE * t->counts[i]); 780 setup_btree_index(i, t); 781 } 782 783 return 0; 784} 785 786/* 787 * Builds the btree to index the map. 788 */ 789int dm_table_complete(struct dm_table *t) 790{ 791 int r = 0; 792 unsigned int leaf_nodes; 793 794 check_for_valid_limits(&t->limits); 795 796 /* how many indexes will the btree have ? */ 797 leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE); 798 t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE); 799 800 /* leaf layer has already been set up */ 801 t->counts[t->depth - 1] = leaf_nodes; 802 t->index[t->depth - 1] = t->highs; 803 804 if (t->depth >= 2) 805 r = setup_indexes(t); 806 807 return r; 808} 809 810static DEFINE_MUTEX(_event_lock); 811void dm_table_event_callback(struct dm_table *t, 812 void (*fn)(void *), void *context) 813{ 814 mutex_lock(&_event_lock); 815 t->event_fn = fn; 816 t->event_context = context; 817 mutex_unlock(&_event_lock); 818} 819 820void dm_table_event(struct dm_table *t) 821{ 822 /* 823 * You can no longer call dm_table_event() from interrupt 824 * context, use a bottom half instead. 825 */ 826 BUG_ON(in_interrupt()); 827 828 mutex_lock(&_event_lock); 829 if (t->event_fn) 830 t->event_fn(t->event_context); 831 mutex_unlock(&_event_lock); 832} 833 834sector_t dm_table_get_size(struct dm_table *t) 835{ 836 return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0; 837} 838 839struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index) 840{ 841 if (index >= t->num_targets) 842 return NULL; 843 844 return t->targets + index; 845} 846 847/* 848 * Search the btree for the correct target. 849 */ 850struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector) 851{ 852 unsigned int l, n = 0, k = 0; 853 sector_t *node; 854 855 for (l = 0; l < t->depth; l++) { 856 n = get_child(n, k); 857 node = get_node(t, l, n); 858 859 for (k = 0; k < KEYS_PER_NODE; k++) 860 if (node[k] >= sector) 861 break; 862 } 863 864 return &t->targets[(KEYS_PER_NODE * n) + k]; 865} 866 867void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q) 868{ 869 /* 870 * Make sure we obey the optimistic sub devices 871 * restrictions. 872 */ 873 blk_queue_max_sectors(q, t->limits.max_sectors); 874 q->max_phys_segments = t->limits.max_phys_segments; 875 q->max_hw_segments = t->limits.max_hw_segments; 876 q->hardsect_size = t->limits.hardsect_size; 877 q->max_segment_size = t->limits.max_segment_size; 878 q->seg_boundary_mask = t->limits.seg_boundary_mask; 879 if (t->limits.no_cluster) 880 q->queue_flags &= ~(1 << QUEUE_FLAG_CLUSTER); 881 else 882 q->queue_flags |= (1 << QUEUE_FLAG_CLUSTER); 883 884} 885 886unsigned int dm_table_get_num_targets(struct dm_table *t) 887{ 888 return t->num_targets; 889} 890 891struct list_head *dm_table_get_devices(struct dm_table *t) 892{ 893 return &t->devices; 894} 895 896int dm_table_get_mode(struct dm_table *t) 897{ 898 return t->mode; 899} 900 901static void suspend_targets(struct dm_table *t, unsigned postsuspend) 902{ 903 int i = t->num_targets; 904 struct dm_target *ti = t->targets; 905 906 while (i--) { 907 if (postsuspend) { 908 if (ti->type->postsuspend) 909 ti->type->postsuspend(ti); 910 } else if (ti->type->presuspend) 911 ti->type->presuspend(ti); 912 913 ti++; 914 } 915} 916 917void dm_table_presuspend_targets(struct dm_table *t) 918{ 919 if (!t) 920 return; 921 922 return suspend_targets(t, 0); 923} 924 925void dm_table_postsuspend_targets(struct dm_table *t) 926{ 927 if (!t) 928 return; 929 930 return suspend_targets(t, 1); 931} 932 933int dm_table_resume_targets(struct dm_table *t) 934{ 935 int i, r = 0; 936 937 for (i = 0; i < t->num_targets; i++) { 938 struct dm_target *ti = t->targets + i; 939 940 if (!ti->type->preresume) 941 continue; 942 943 r = ti->type->preresume(ti); 944 if (r) 945 return r; 946 } 947 948 for (i = 0; i < t->num_targets; i++) { 949 struct dm_target *ti = t->targets + i; 950 951 if (ti->type->resume) 952 ti->type->resume(ti); 953 } 954 955 return 0; 956} 957 958int dm_table_any_congested(struct dm_table *t, int bdi_bits) 959{ 960 struct list_head *d, *devices; 961 int r = 0; 962 963 devices = dm_table_get_devices(t); 964 for (d = devices->next; d != devices; d = d->next) { 965 struct dm_dev *dd = list_entry(d, struct dm_dev, list); 966 request_queue_t *q = bdev_get_queue(dd->bdev); 967 r |= bdi_congested(&q->backing_dev_info, bdi_bits); 968 } 969 970 return r; 971} 972 973void dm_table_unplug_all(struct dm_table *t) 974{ 975 struct list_head *d, *devices = dm_table_get_devices(t); 976 977 for (d = devices->next; d != devices; d = d->next) { 978 struct dm_dev *dd = list_entry(d, struct dm_dev, list); 979 request_queue_t *q = bdev_get_queue(dd->bdev); 980 981 if (q->unplug_fn) 982 q->unplug_fn(q); 983 } 984} 985 986int dm_table_flush_all(struct dm_table *t) 987{ 988 struct list_head *d, *devices = dm_table_get_devices(t); 989 int ret = 0; 990 unsigned i; 991 992 for (i = 0; i < t->num_targets; i++) 993 if (t->targets[i].type->flush) 994 t->targets[i].type->flush(&t->targets[i]); 995 996 for (d = devices->next; d != devices; d = d->next) { 997 struct dm_dev *dd = list_entry(d, struct dm_dev, list); 998 request_queue_t *q = bdev_get_queue(dd->bdev); 999 int err; 1000 1001 if (!q->issue_flush_fn) 1002 err = -EOPNOTSUPP; 1003 else 1004 err = q->issue_flush_fn(q, dd->bdev->bd_disk, NULL); 1005 1006 if (!ret) 1007 ret = err; 1008 } 1009 1010 return ret; 1011} 1012 1013struct mapped_device *dm_table_get_md(struct dm_table *t) 1014{ 1015 dm_get(t->md); 1016 1017 return t->md; 1018} 1019 1020EXPORT_SYMBOL(dm_vcalloc); 1021EXPORT_SYMBOL(dm_get_device); 1022EXPORT_SYMBOL(dm_put_device); 1023EXPORT_SYMBOL(dm_table_event); 1024EXPORT_SYMBOL(dm_table_get_size); 1025EXPORT_SYMBOL(dm_table_get_mode); 1026EXPORT_SYMBOL(dm_table_get_md); 1027EXPORT_SYMBOL(dm_table_put); 1028EXPORT_SYMBOL(dm_table_get); 1029EXPORT_SYMBOL(dm_table_unplug_all); 1030EXPORT_SYMBOL(dm_table_flush_all); 1031