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->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 */ 111 static 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 */ 119 static 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 */ 129 static 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 */ 144 static 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 } 158 159 void *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 */ 182 static 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 } 212 213 int 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 } 241 242 int 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; 271 272 out: 273 if (r) 274 dm_table_put(t); 275 276 return r; 277 } 278 EXPORT_SYMBOL_GPL(dm_create_error_table); 279 280 static 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 } 290 291 static 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 } 321 322 void dm_table_get(struct dm_table *t) 323 { 324 atomic_inc(&t->holders); 325 } 326 327 void 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 */ 339 static 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 */ 350 static 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 */ 380 static 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 */ 394 static 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 */ 417 static 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 (ie. blk_size[major] is set), this checks an area 429 * of a destination device is valid. 430 */ 431 static int check_device_area(struct dm_dev *dd, sector_t start, sector_t len) 432 { 433 sector_t dev_size; 434 dev_size = dd->bdev->bd_inode->i_size >> SECTOR_SHIFT; 435 return ((start < dev_size) && (len <= (dev_size - start))); 436 } 437 438 /* 439 * This upgrades the mode on an already open dm_dev. Being 440 * careful to leave things as they were if we fail to reopen the 441 * device. 442 */ 443 static int upgrade_mode(struct dm_dev *dd, int new_mode, struct mapped_device *md) 444 { 445 int r; 446 struct dm_dev dd_copy; 447 dev_t dev = dd->bdev->bd_dev; 448 449 dd_copy = *dd; 450 451 dd->mode |= new_mode; 452 dd->bdev = NULL; 453 r = open_dev(dd, dev, md); 454 if (!r) 455 close_dev(&dd_copy, md); 456 else 457 *dd = dd_copy; 458 459 return r; 460 } 461 462 /* 463 * Add a device to the list, or just increment the usage count if 464 * it's already present. 465 */ 466 static int __table_get_device(struct dm_table *t, struct dm_target *ti, 467 const char *path, sector_t start, sector_t len, 468 int mode, struct dm_dev **result) 469 { 470 int r; 471 dev_t dev; 472 struct dm_dev *dd; 473 unsigned int major, minor; 474 475 BUG_ON(!t); 476 477 if (sscanf(path, "%u:%u", &major, &minor) == 2) { 478 /* Extract the major/minor numbers */ 479 dev = MKDEV(major, minor); 480 if (MAJOR(dev) != major || MINOR(dev) != minor) 481 return -EOVERFLOW; 482 } else { 483 /* convert the path to a device */ 484 if ((r = lookup_device(path, &dev))) 485 return r; 486 } 487 488 dd = find_device(&t->devices, dev); 489 if (!dd) { 490 dd = kmalloc(sizeof(*dd), GFP_KERNEL); 491 if (!dd) 492 return -ENOMEM; 493 494 dd->mode = mode; 495 dd->bdev = NULL; 496 497 if ((r = open_dev(dd, dev, t->md))) { 498 kfree(dd); 499 return r; 500 } 501 502 format_dev_t(dd->name, dev); 503 504 atomic_set(&dd->count, 0); 505 list_add(&dd->list, &t->devices); 506 507 } else if (dd->mode != (mode | dd->mode)) { 508 r = upgrade_mode(dd, mode, t->md); 509 if (r) 510 return r; 511 } 512 atomic_inc(&dd->count); 513 514 if (!check_device_area(dd, start, len)) { 515 DMWARN("device %s too small for target", path); 516 dm_put_device(ti, dd); 517 return -EINVAL; 518 } 519 520 *result = dd; 521 522 return 0; 523 } 524 525 526 int dm_get_device(struct dm_target *ti, const char *path, sector_t start, 527 sector_t len, int mode, struct dm_dev **result) 528 { 529 int r = __table_get_device(ti->table, ti, path, 530 start, len, mode, result); 531 if (!r) { 532 request_queue_t *q = bdev_get_queue((*result)->bdev); 533 struct io_restrictions *rs = &ti->limits; 534 535 /* 536 * Combine the device limits low. 537 * 538 * FIXME: if we move an io_restriction struct 539 * into q this would just be a call to 540 * combine_restrictions_low() 541 */ 542 rs->max_sectors = 543 min_not_zero(rs->max_sectors, q->max_sectors); 544 545 /* FIXME: Device-Mapper on top of RAID-0 breaks because DM 546 * currently doesn't honor MD's merge_bvec_fn routine. 547 * In this case, we'll force DM to use PAGE_SIZE or 548 * smaller I/O, just to be safe. A better fix is in the 549 * works, but add this for the time being so it will at 550 * least operate correctly. 551 */ 552 if (q->merge_bvec_fn) 553 rs->max_sectors = 554 min_not_zero(rs->max_sectors, 555 (unsigned int) (PAGE_SIZE >> 9)); 556 557 rs->max_phys_segments = 558 min_not_zero(rs->max_phys_segments, 559 q->max_phys_segments); 560 561 rs->max_hw_segments = 562 min_not_zero(rs->max_hw_segments, q->max_hw_segments); 563 564 rs->hardsect_size = max(rs->hardsect_size, q->hardsect_size); 565 566 rs->max_segment_size = 567 min_not_zero(rs->max_segment_size, q->max_segment_size); 568 569 rs->seg_boundary_mask = 570 min_not_zero(rs->seg_boundary_mask, 571 q->seg_boundary_mask); 572 573 rs->no_cluster |= !test_bit(QUEUE_FLAG_CLUSTER, &q->queue_flags); 574 } 575 576 return r; 577 } 578 579 /* 580 * Decrement a devices use count and remove it if necessary. 581 */ 582 void dm_put_device(struct dm_target *ti, struct dm_dev *dd) 583 { 584 if (atomic_dec_and_test(&dd->count)) { 585 close_dev(dd, ti->table->md); 586 list_del(&dd->list); 587 kfree(dd); 588 } 589 } 590 591 /* 592 * Checks to see if the target joins onto the end of the table. 593 */ 594 static int adjoin(struct dm_table *table, struct dm_target *ti) 595 { 596 struct dm_target *prev; 597 598 if (!table->num_targets) 599 return !ti->begin; 600 601 prev = &table->targets[table->num_targets - 1]; 602 return (ti->begin == (prev->begin + prev->len)); 603 } 604 605 /* 606 * Used to dynamically allocate the arg array. 607 */ 608 static char **realloc_argv(unsigned *array_size, char **old_argv) 609 { 610 char **argv; 611 unsigned new_size; 612 613 new_size = *array_size ? *array_size * 2 : 64; 614 argv = kmalloc(new_size * sizeof(*argv), GFP_KERNEL); 615 if (argv) { 616 memcpy(argv, old_argv, *array_size * sizeof(*argv)); 617 *array_size = new_size; 618 } 619 620 kfree(old_argv); 621 return argv; 622 } 623 624 /* 625 * Destructively splits up the argument list to pass to ctr. 626 */ 627 int dm_split_args(int *argc, char ***argvp, char *input) 628 { 629 char *start, *end = input, *out, **argv = NULL; 630 unsigned array_size = 0; 631 632 *argc = 0; 633 634 if (!input) { 635 *argvp = NULL; 636 return 0; 637 } 638 639 argv = realloc_argv(&array_size, argv); 640 if (!argv) 641 return -ENOMEM; 642 643 while (1) { 644 start = end; 645 646 /* Skip whitespace */ 647 while (*start && isspace(*start)) 648 start++; 649 650 if (!*start) 651 break; /* success, we hit the end */ 652 653 /* 'out' is used to remove any back-quotes */ 654 end = out = start; 655 while (*end) { 656 /* Everything apart from '\0' can be quoted */ 657 if (*end == '\\' && *(end + 1)) { 658 *out++ = *(end + 1); 659 end += 2; 660 continue; 661 } 662 663 if (isspace(*end)) 664 break; /* end of token */ 665 666 *out++ = *end++; 667 } 668 669 /* have we already filled the array ? */ 670 if ((*argc + 1) > array_size) { 671 argv = realloc_argv(&array_size, argv); 672 if (!argv) 673 return -ENOMEM; 674 } 675 676 /* we know this is whitespace */ 677 if (*end) 678 end++; 679 680 /* terminate the string and put it in the array */ 681 *out = '\0'; 682 argv[*argc] = start; 683 (*argc)++; 684 } 685 686 *argvp = argv; 687 return 0; 688 } 689 690 static void check_for_valid_limits(struct io_restrictions *rs) 691 { 692 if (!rs->max_sectors) 693 rs->max_sectors = SAFE_MAX_SECTORS; 694 if (!rs->max_phys_segments) 695 rs->max_phys_segments = MAX_PHYS_SEGMENTS; 696 if (!rs->max_hw_segments) 697 rs->max_hw_segments = MAX_HW_SEGMENTS; 698 if (!rs->hardsect_size) 699 rs->hardsect_size = 1 << SECTOR_SHIFT; 700 if (!rs->max_segment_size) 701 rs->max_segment_size = MAX_SEGMENT_SIZE; 702 if (!rs->seg_boundary_mask) 703 rs->seg_boundary_mask = -1; 704 } 705 706 int dm_table_add_target(struct dm_table *t, const char *type, 707 sector_t start, sector_t len, char *params) 708 { 709 int r = -EINVAL, argc; 710 char **argv; 711 struct dm_target *tgt; 712 713 if ((r = check_space(t))) 714 return r; 715 716 tgt = t->targets + t->num_targets; 717 memset(tgt, 0, sizeof(*tgt)); 718 719 if (!len) { 720 DMERR("%s: zero-length target", dm_device_name(t->md)); 721 return -EINVAL; 722 } 723 724 tgt->type = dm_get_target_type(type); 725 if (!tgt->type) { 726 DMERR("%s: %s: unknown target type", dm_device_name(t->md), 727 type); 728 return -EINVAL; 729 } 730 731 tgt->table = t; 732 tgt->begin = start; 733 tgt->len = len; 734 tgt->error = "Unknown error"; 735 736 /* 737 * Does this target adjoin the previous one ? 738 */ 739 if (!adjoin(t, tgt)) { 740 tgt->error = "Gap in table"; 741 r = -EINVAL; 742 goto bad; 743 } 744 745 r = dm_split_args(&argc, &argv, params); 746 if (r) { 747 tgt->error = "couldn't split parameters (insufficient memory)"; 748 goto bad; 749 } 750 751 r = tgt->type->ctr(tgt, argc, argv); 752 kfree(argv); 753 if (r) 754 goto bad; 755 756 t->highs[t->num_targets++] = tgt->begin + tgt->len - 1; 757 758 /* FIXME: the plan is to combine high here and then have 759 * the merge fn apply the target level restrictions. */ 760 combine_restrictions_low(&t->limits, &tgt->limits); 761 return 0; 762 763 bad: 764 DMERR("%s: %s: %s", dm_device_name(t->md), type, tgt->error); 765 dm_put_target_type(tgt->type); 766 return r; 767 } 768 769 static int setup_indexes(struct dm_table *t) 770 { 771 int i; 772 unsigned int total = 0; 773 sector_t *indexes; 774 775 /* allocate the space for *all* the indexes */ 776 for (i = t->depth - 2; i >= 0; i--) { 777 t->counts[i] = dm_div_up(t->counts[i + 1], CHILDREN_PER_NODE); 778 total += t->counts[i]; 779 } 780 781 indexes = (sector_t *) dm_vcalloc(total, (unsigned long) NODE_SIZE); 782 if (!indexes) 783 return -ENOMEM; 784 785 /* set up internal nodes, bottom-up */ 786 for (i = t->depth - 2, total = 0; i >= 0; i--) { 787 t->index[i] = indexes; 788 indexes += (KEYS_PER_NODE * t->counts[i]); 789 setup_btree_index(i, t); 790 } 791 792 return 0; 793 } 794 795 /* 796 * Builds the btree to index the map. 797 */ 798 int dm_table_complete(struct dm_table *t) 799 { 800 int r = 0; 801 unsigned int leaf_nodes; 802 803 check_for_valid_limits(&t->limits); 804 805 /* how many indexes will the btree have ? */ 806 leaf_nodes = dm_div_up(t->num_targets, KEYS_PER_NODE); 807 t->depth = 1 + int_log(leaf_nodes, CHILDREN_PER_NODE); 808 809 /* leaf layer has already been set up */ 810 t->counts[t->depth - 1] = leaf_nodes; 811 t->index[t->depth - 1] = t->highs; 812 813 if (t->depth >= 2) 814 r = setup_indexes(t); 815 816 return r; 817 } 818 819 static DEFINE_MUTEX(_event_lock); 820 void dm_table_event_callback(struct dm_table *t, 821 void (*fn)(void *), void *context) 822 { 823 mutex_lock(&_event_lock); 824 t->event_fn = fn; 825 t->event_context = context; 826 mutex_unlock(&_event_lock); 827 } 828 829 void dm_table_event(struct dm_table *t) 830 { 831 /* 832 * You can no longer call dm_table_event() from interrupt 833 * context, use a bottom half instead. 834 */ 835 BUG_ON(in_interrupt()); 836 837 mutex_lock(&_event_lock); 838 if (t->event_fn) 839 t->event_fn(t->event_context); 840 mutex_unlock(&_event_lock); 841 } 842 843 sector_t dm_table_get_size(struct dm_table *t) 844 { 845 return t->num_targets ? (t->highs[t->num_targets - 1] + 1) : 0; 846 } 847 848 struct dm_target *dm_table_get_target(struct dm_table *t, unsigned int index) 849 { 850 if (index >= t->num_targets) 851 return NULL; 852 853 return t->targets + index; 854 } 855 856 /* 857 * Search the btree for the correct target. 858 */ 859 struct dm_target *dm_table_find_target(struct dm_table *t, sector_t sector) 860 { 861 unsigned int l, n = 0, k = 0; 862 sector_t *node; 863 864 for (l = 0; l < t->depth; l++) { 865 n = get_child(n, k); 866 node = get_node(t, l, n); 867 868 for (k = 0; k < KEYS_PER_NODE; k++) 869 if (node[k] >= sector) 870 break; 871 } 872 873 return &t->targets[(KEYS_PER_NODE * n) + k]; 874 } 875 876 void dm_table_set_restrictions(struct dm_table *t, struct request_queue *q) 877 { 878 /* 879 * Make sure we obey the optimistic sub devices 880 * restrictions. 881 */ 882 blk_queue_max_sectors(q, t->limits.max_sectors); 883 q->max_phys_segments = t->limits.max_phys_segments; 884 q->max_hw_segments = t->limits.max_hw_segments; 885 q->hardsect_size = t->limits.hardsect_size; 886 q->max_segment_size = t->limits.max_segment_size; 887 q->seg_boundary_mask = t->limits.seg_boundary_mask; 888 if (t->limits.no_cluster) 889 q->queue_flags &= ~(1 << QUEUE_FLAG_CLUSTER); 890 else 891 q->queue_flags |= (1 << QUEUE_FLAG_CLUSTER); 892 893 } 894 895 unsigned int dm_table_get_num_targets(struct dm_table *t) 896 { 897 return t->num_targets; 898 } 899 900 struct list_head *dm_table_get_devices(struct dm_table *t) 901 { 902 return &t->devices; 903 } 904 905 int dm_table_get_mode(struct dm_table *t) 906 { 907 return t->mode; 908 } 909 910 static void suspend_targets(struct dm_table *t, unsigned postsuspend) 911 { 912 int i = t->num_targets; 913 struct dm_target *ti = t->targets; 914 915 while (i--) { 916 if (postsuspend) { 917 if (ti->type->postsuspend) 918 ti->type->postsuspend(ti); 919 } else if (ti->type->presuspend) 920 ti->type->presuspend(ti); 921 922 ti++; 923 } 924 } 925 926 void dm_table_presuspend_targets(struct dm_table *t) 927 { 928 if (!t) 929 return; 930 931 return suspend_targets(t, 0); 932 } 933 934 void dm_table_postsuspend_targets(struct dm_table *t) 935 { 936 if (!t) 937 return; 938 939 return suspend_targets(t, 1); 940 } 941 942 void dm_table_resume_targets(struct dm_table *t) 943 { 944 int i; 945 946 for (i = 0; i < t->num_targets; i++) { 947 struct dm_target *ti = t->targets + i; 948 949 if (ti->type->resume) 950 ti->type->resume(ti); 951 } 952 } 953 954 int dm_table_any_congested(struct dm_table *t, int bdi_bits) 955 { 956 struct list_head *d, *devices; 957 int r = 0; 958 959 devices = dm_table_get_devices(t); 960 for (d = devices->next; d != devices; d = d->next) { 961 struct dm_dev *dd = list_entry(d, struct dm_dev, list); 962 request_queue_t *q = bdev_get_queue(dd->bdev); 963 r |= bdi_congested(&q->backing_dev_info, bdi_bits); 964 } 965 966 return r; 967 } 968 969 void dm_table_unplug_all(struct dm_table *t) 970 { 971 struct list_head *d, *devices = dm_table_get_devices(t); 972 973 for (d = devices->next; d != devices; d = d->next) { 974 struct dm_dev *dd = list_entry(d, struct dm_dev, list); 975 request_queue_t *q = bdev_get_queue(dd->bdev); 976 977 if (q->unplug_fn) 978 q->unplug_fn(q); 979 } 980 } 981 982 int dm_table_flush_all(struct dm_table *t) 983 { 984 struct list_head *d, *devices = dm_table_get_devices(t); 985 int ret = 0; 986 987 for (d = devices->next; d != devices; d = d->next) { 988 struct dm_dev *dd = list_entry(d, struct dm_dev, list); 989 request_queue_t *q = bdev_get_queue(dd->bdev); 990 int err; 991 992 if (!q->issue_flush_fn) 993 err = -EOPNOTSUPP; 994 else 995 err = q->issue_flush_fn(q, dd->bdev->bd_disk, NULL); 996 997 if (!ret) 998 ret = err; 999 } 1000 1001 return ret; 1002 } 1003 1004 struct mapped_device *dm_table_get_md(struct dm_table *t) 1005 { 1006 dm_get(t->md); 1007 1008 return t->md; 1009 } 1010 1011 EXPORT_SYMBOL(dm_vcalloc); 1012 EXPORT_SYMBOL(dm_get_device); 1013 EXPORT_SYMBOL(dm_put_device); 1014 EXPORT_SYMBOL(dm_table_event); 1015 EXPORT_SYMBOL(dm_table_get_size); 1016 EXPORT_SYMBOL(dm_table_get_mode); 1017 EXPORT_SYMBOL(dm_table_get_md); 1018 EXPORT_SYMBOL(dm_table_put); 1019 EXPORT_SYMBOL(dm_table_get); 1020 EXPORT_SYMBOL(dm_table_unplug_all); 1021 EXPORT_SYMBOL(dm_table_flush_all); 1022