1 /* 2 * Copyright (C) 2003 Sistina Software 3 * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved. 4 * 5 * This file is released under the LGPL. 6 */ 7 8 #include <linux/init.h> 9 #include <linux/slab.h> 10 #include <linux/module.h> 11 #include <linux/vmalloc.h> 12 #include <linux/dm-io.h> 13 #include <linux/dm-dirty-log.h> 14 15 #include "dm.h" 16 17 #define DM_MSG_PREFIX "dirty region log" 18 19 struct dm_dirty_log_internal { 20 struct dm_dirty_log_type *type; 21 22 struct list_head list; 23 long use; 24 }; 25 26 static LIST_HEAD(_log_types); 27 static DEFINE_SPINLOCK(_lock); 28 29 static struct dm_dirty_log_internal *__find_dirty_log_type(const char *name) 30 { 31 struct dm_dirty_log_internal *log_type; 32 33 list_for_each_entry(log_type, &_log_types, list) 34 if (!strcmp(name, log_type->type->name)) 35 return log_type; 36 37 return NULL; 38 } 39 40 static struct dm_dirty_log_internal *_get_dirty_log_type(const char *name) 41 { 42 struct dm_dirty_log_internal *log_type; 43 44 spin_lock(&_lock); 45 46 log_type = __find_dirty_log_type(name); 47 if (log_type) { 48 if (!log_type->use && !try_module_get(log_type->type->module)) 49 log_type = NULL; 50 else 51 log_type->use++; 52 } 53 54 spin_unlock(&_lock); 55 56 return log_type; 57 } 58 59 /* 60 * get_type 61 * @type_name 62 * 63 * Attempt to retrieve the dm_dirty_log_type by name. If not already 64 * available, attempt to load the appropriate module. 65 * 66 * Log modules are named "dm-log-" followed by the 'type_name'. 67 * Modules may contain multiple types. 68 * This function will first try the module "dm-log-<type_name>", 69 * then truncate 'type_name' on the last '-' and try again. 70 * 71 * For example, if type_name was "clustered-disk", it would search 72 * 'dm-log-clustered-disk' then 'dm-log-clustered'. 73 * 74 * Returns: dirty_log_type* on success, NULL on failure 75 */ 76 static struct dm_dirty_log_type *get_type(const char *type_name) 77 { 78 char *p, *type_name_dup; 79 struct dm_dirty_log_internal *log_type; 80 81 if (!type_name) 82 return NULL; 83 84 log_type = _get_dirty_log_type(type_name); 85 if (log_type) 86 return log_type->type; 87 88 type_name_dup = kstrdup(type_name, GFP_KERNEL); 89 if (!type_name_dup) { 90 DMWARN("No memory left to attempt log module load for \"%s\"", 91 type_name); 92 return NULL; 93 } 94 95 while (request_module("dm-log-%s", type_name_dup) || 96 !(log_type = _get_dirty_log_type(type_name))) { 97 p = strrchr(type_name_dup, '-'); 98 if (!p) 99 break; 100 p[0] = '\0'; 101 } 102 103 if (!log_type) 104 DMWARN("Module for logging type \"%s\" not found.", type_name); 105 106 kfree(type_name_dup); 107 108 return log_type ? log_type->type : NULL; 109 } 110 111 static void put_type(struct dm_dirty_log_type *type) 112 { 113 struct dm_dirty_log_internal *log_type; 114 115 if (!type) 116 return; 117 118 spin_lock(&_lock); 119 log_type = __find_dirty_log_type(type->name); 120 if (!log_type) 121 goto out; 122 123 if (!--log_type->use) 124 module_put(type->module); 125 126 BUG_ON(log_type->use < 0); 127 128 out: 129 spin_unlock(&_lock); 130 } 131 132 static struct dm_dirty_log_internal *_alloc_dirty_log_type(struct dm_dirty_log_type *type) 133 { 134 struct dm_dirty_log_internal *log_type = kzalloc(sizeof(*log_type), 135 GFP_KERNEL); 136 137 if (log_type) 138 log_type->type = type; 139 140 return log_type; 141 } 142 143 int dm_dirty_log_type_register(struct dm_dirty_log_type *type) 144 { 145 struct dm_dirty_log_internal *log_type = _alloc_dirty_log_type(type); 146 int r = 0; 147 148 if (!log_type) 149 return -ENOMEM; 150 151 spin_lock(&_lock); 152 if (!__find_dirty_log_type(type->name)) 153 list_add(&log_type->list, &_log_types); 154 else { 155 kfree(log_type); 156 r = -EEXIST; 157 } 158 spin_unlock(&_lock); 159 160 return r; 161 } 162 EXPORT_SYMBOL(dm_dirty_log_type_register); 163 164 int dm_dirty_log_type_unregister(struct dm_dirty_log_type *type) 165 { 166 struct dm_dirty_log_internal *log_type; 167 168 spin_lock(&_lock); 169 170 log_type = __find_dirty_log_type(type->name); 171 if (!log_type) { 172 spin_unlock(&_lock); 173 return -EINVAL; 174 } 175 176 if (log_type->use) { 177 spin_unlock(&_lock); 178 return -ETXTBSY; 179 } 180 181 list_del(&log_type->list); 182 183 spin_unlock(&_lock); 184 kfree(log_type); 185 186 return 0; 187 } 188 EXPORT_SYMBOL(dm_dirty_log_type_unregister); 189 190 struct dm_dirty_log *dm_dirty_log_create(const char *type_name, 191 struct dm_target *ti, 192 unsigned int argc, char **argv) 193 { 194 struct dm_dirty_log_type *type; 195 struct dm_dirty_log *log; 196 197 log = kmalloc(sizeof(*log), GFP_KERNEL); 198 if (!log) 199 return NULL; 200 201 type = get_type(type_name); 202 if (!type) { 203 kfree(log); 204 return NULL; 205 } 206 207 log->type = type; 208 if (type->ctr(log, ti, argc, argv)) { 209 kfree(log); 210 put_type(type); 211 return NULL; 212 } 213 214 return log; 215 } 216 EXPORT_SYMBOL(dm_dirty_log_create); 217 218 void dm_dirty_log_destroy(struct dm_dirty_log *log) 219 { 220 log->type->dtr(log); 221 put_type(log->type); 222 kfree(log); 223 } 224 EXPORT_SYMBOL(dm_dirty_log_destroy); 225 226 /*----------------------------------------------------------------- 227 * Persistent and core logs share a lot of their implementation. 228 * FIXME: need a reload method to be called from a resume 229 *---------------------------------------------------------------*/ 230 /* 231 * Magic for persistent mirrors: "MiRr" 232 */ 233 #define MIRROR_MAGIC 0x4D695272 234 235 /* 236 * The on-disk version of the metadata. 237 */ 238 #define MIRROR_DISK_VERSION 2 239 #define LOG_OFFSET 2 240 241 struct log_header { 242 uint32_t magic; 243 244 /* 245 * Simple, incrementing version. no backward 246 * compatibility. 247 */ 248 uint32_t version; 249 sector_t nr_regions; 250 }; 251 252 struct log_c { 253 struct dm_target *ti; 254 int touched; 255 uint32_t region_size; 256 unsigned int region_count; 257 region_t sync_count; 258 259 unsigned bitset_uint32_count; 260 uint32_t *clean_bits; 261 uint32_t *sync_bits; 262 uint32_t *recovering_bits; /* FIXME: this seems excessive */ 263 264 int sync_search; 265 266 /* Resync flag */ 267 enum sync { 268 DEFAULTSYNC, /* Synchronize if necessary */ 269 NOSYNC, /* Devices known to be already in sync */ 270 FORCESYNC, /* Force a sync to happen */ 271 } sync; 272 273 struct dm_io_request io_req; 274 275 /* 276 * Disk log fields 277 */ 278 int log_dev_failed; 279 struct dm_dev *log_dev; 280 struct log_header header; 281 282 struct dm_io_region header_location; 283 struct log_header *disk_header; 284 }; 285 286 /* 287 * The touched member needs to be updated every time we access 288 * one of the bitsets. 289 */ 290 static inline int log_test_bit(uint32_t *bs, unsigned bit) 291 { 292 return ext2_test_bit(bit, (unsigned long *) bs) ? 1 : 0; 293 } 294 295 static inline void log_set_bit(struct log_c *l, 296 uint32_t *bs, unsigned bit) 297 { 298 ext2_set_bit(bit, (unsigned long *) bs); 299 l->touched = 1; 300 } 301 302 static inline void log_clear_bit(struct log_c *l, 303 uint32_t *bs, unsigned bit) 304 { 305 ext2_clear_bit(bit, (unsigned long *) bs); 306 l->touched = 1; 307 } 308 309 /*---------------------------------------------------------------- 310 * Header IO 311 *--------------------------------------------------------------*/ 312 static void header_to_disk(struct log_header *core, struct log_header *disk) 313 { 314 disk->magic = cpu_to_le32(core->magic); 315 disk->version = cpu_to_le32(core->version); 316 disk->nr_regions = cpu_to_le64(core->nr_regions); 317 } 318 319 static void header_from_disk(struct log_header *core, struct log_header *disk) 320 { 321 core->magic = le32_to_cpu(disk->magic); 322 core->version = le32_to_cpu(disk->version); 323 core->nr_regions = le64_to_cpu(disk->nr_regions); 324 } 325 326 static int rw_header(struct log_c *lc, int rw) 327 { 328 lc->io_req.bi_rw = rw; 329 lc->io_req.mem.ptr.vma = lc->disk_header; 330 lc->io_req.notify.fn = NULL; 331 332 return dm_io(&lc->io_req, 1, &lc->header_location, NULL); 333 } 334 335 static int read_header(struct log_c *log) 336 { 337 int r; 338 339 r = rw_header(log, READ); 340 if (r) 341 return r; 342 343 header_from_disk(&log->header, log->disk_header); 344 345 /* New log required? */ 346 if (log->sync != DEFAULTSYNC || log->header.magic != MIRROR_MAGIC) { 347 log->header.magic = MIRROR_MAGIC; 348 log->header.version = MIRROR_DISK_VERSION; 349 log->header.nr_regions = 0; 350 } 351 352 #ifdef __LITTLE_ENDIAN 353 if (log->header.version == 1) 354 log->header.version = 2; 355 #endif 356 357 if (log->header.version != MIRROR_DISK_VERSION) { 358 DMWARN("incompatible disk log version"); 359 return -EINVAL; 360 } 361 362 return 0; 363 } 364 365 static inline int write_header(struct log_c *log) 366 { 367 header_to_disk(&log->header, log->disk_header); 368 return rw_header(log, WRITE); 369 } 370 371 /*---------------------------------------------------------------- 372 * core log constructor/destructor 373 * 374 * argv contains region_size followed optionally by [no]sync 375 *--------------------------------------------------------------*/ 376 #define BYTE_SHIFT 3 377 static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti, 378 unsigned int argc, char **argv, 379 struct dm_dev *dev) 380 { 381 enum sync sync = DEFAULTSYNC; 382 383 struct log_c *lc; 384 uint32_t region_size; 385 unsigned int region_count; 386 size_t bitset_size, buf_size; 387 int r; 388 389 if (argc < 1 || argc > 2) { 390 DMWARN("wrong number of arguments to dirty region log"); 391 return -EINVAL; 392 } 393 394 if (argc > 1) { 395 if (!strcmp(argv[1], "sync")) 396 sync = FORCESYNC; 397 else if (!strcmp(argv[1], "nosync")) 398 sync = NOSYNC; 399 else { 400 DMWARN("unrecognised sync argument to " 401 "dirty region log: %s", argv[1]); 402 return -EINVAL; 403 } 404 } 405 406 if (sscanf(argv[0], "%u", ®ion_size) != 1) { 407 DMWARN("invalid region size string"); 408 return -EINVAL; 409 } 410 411 region_count = dm_sector_div_up(ti->len, region_size); 412 413 lc = kmalloc(sizeof(*lc), GFP_KERNEL); 414 if (!lc) { 415 DMWARN("couldn't allocate core log"); 416 return -ENOMEM; 417 } 418 419 lc->ti = ti; 420 lc->touched = 0; 421 lc->region_size = region_size; 422 lc->region_count = region_count; 423 lc->sync = sync; 424 425 /* 426 * Work out how many "unsigned long"s we need to hold the bitset. 427 */ 428 bitset_size = dm_round_up(region_count, 429 sizeof(*lc->clean_bits) << BYTE_SHIFT); 430 bitset_size >>= BYTE_SHIFT; 431 432 lc->bitset_uint32_count = bitset_size / sizeof(*lc->clean_bits); 433 434 /* 435 * Disk log? 436 */ 437 if (!dev) { 438 lc->clean_bits = vmalloc(bitset_size); 439 if (!lc->clean_bits) { 440 DMWARN("couldn't allocate clean bitset"); 441 kfree(lc); 442 return -ENOMEM; 443 } 444 lc->disk_header = NULL; 445 } else { 446 lc->log_dev = dev; 447 lc->log_dev_failed = 0; 448 lc->header_location.bdev = lc->log_dev->bdev; 449 lc->header_location.sector = 0; 450 451 /* 452 * Buffer holds both header and bitset. 453 */ 454 buf_size = dm_round_up((LOG_OFFSET << SECTOR_SHIFT) + 455 bitset_size, ti->limits.hardsect_size); 456 lc->header_location.count = buf_size >> SECTOR_SHIFT; 457 lc->io_req.mem.type = DM_IO_VMA; 458 lc->io_req.client = dm_io_client_create(dm_div_up(buf_size, 459 PAGE_SIZE)); 460 if (IS_ERR(lc->io_req.client)) { 461 r = PTR_ERR(lc->io_req.client); 462 DMWARN("couldn't allocate disk io client"); 463 kfree(lc); 464 return -ENOMEM; 465 } 466 467 lc->disk_header = vmalloc(buf_size); 468 if (!lc->disk_header) { 469 DMWARN("couldn't allocate disk log buffer"); 470 kfree(lc); 471 return -ENOMEM; 472 } 473 474 lc->clean_bits = (void *)lc->disk_header + 475 (LOG_OFFSET << SECTOR_SHIFT); 476 } 477 478 memset(lc->clean_bits, -1, bitset_size); 479 480 lc->sync_bits = vmalloc(bitset_size); 481 if (!lc->sync_bits) { 482 DMWARN("couldn't allocate sync bitset"); 483 if (!dev) 484 vfree(lc->clean_bits); 485 vfree(lc->disk_header); 486 kfree(lc); 487 return -ENOMEM; 488 } 489 memset(lc->sync_bits, (sync == NOSYNC) ? -1 : 0, bitset_size); 490 lc->sync_count = (sync == NOSYNC) ? region_count : 0; 491 492 lc->recovering_bits = vmalloc(bitset_size); 493 if (!lc->recovering_bits) { 494 DMWARN("couldn't allocate sync bitset"); 495 vfree(lc->sync_bits); 496 if (!dev) 497 vfree(lc->clean_bits); 498 vfree(lc->disk_header); 499 kfree(lc); 500 return -ENOMEM; 501 } 502 memset(lc->recovering_bits, 0, bitset_size); 503 lc->sync_search = 0; 504 log->context = lc; 505 506 return 0; 507 } 508 509 static int core_ctr(struct dm_dirty_log *log, struct dm_target *ti, 510 unsigned int argc, char **argv) 511 { 512 return create_log_context(log, ti, argc, argv, NULL); 513 } 514 515 static void destroy_log_context(struct log_c *lc) 516 { 517 vfree(lc->sync_bits); 518 vfree(lc->recovering_bits); 519 kfree(lc); 520 } 521 522 static void core_dtr(struct dm_dirty_log *log) 523 { 524 struct log_c *lc = (struct log_c *) log->context; 525 526 vfree(lc->clean_bits); 527 destroy_log_context(lc); 528 } 529 530 /*---------------------------------------------------------------- 531 * disk log constructor/destructor 532 * 533 * argv contains log_device region_size followed optionally by [no]sync 534 *--------------------------------------------------------------*/ 535 static int disk_ctr(struct dm_dirty_log *log, struct dm_target *ti, 536 unsigned int argc, char **argv) 537 { 538 int r; 539 struct dm_dev *dev; 540 541 if (argc < 2 || argc > 3) { 542 DMWARN("wrong number of arguments to disk dirty region log"); 543 return -EINVAL; 544 } 545 546 r = dm_get_device(ti, argv[0], 0, 0 /* FIXME */, 547 FMODE_READ | FMODE_WRITE, &dev); 548 if (r) 549 return r; 550 551 r = create_log_context(log, ti, argc - 1, argv + 1, dev); 552 if (r) { 553 dm_put_device(ti, dev); 554 return r; 555 } 556 557 return 0; 558 } 559 560 static void disk_dtr(struct dm_dirty_log *log) 561 { 562 struct log_c *lc = (struct log_c *) log->context; 563 564 dm_put_device(lc->ti, lc->log_dev); 565 vfree(lc->disk_header); 566 dm_io_client_destroy(lc->io_req.client); 567 destroy_log_context(lc); 568 } 569 570 static int count_bits32(uint32_t *addr, unsigned size) 571 { 572 int count = 0, i; 573 574 for (i = 0; i < size; i++) { 575 count += hweight32(*(addr+i)); 576 } 577 return count; 578 } 579 580 static void fail_log_device(struct log_c *lc) 581 { 582 if (lc->log_dev_failed) 583 return; 584 585 lc->log_dev_failed = 1; 586 dm_table_event(lc->ti->table); 587 } 588 589 static int disk_resume(struct dm_dirty_log *log) 590 { 591 int r; 592 unsigned i; 593 struct log_c *lc = (struct log_c *) log->context; 594 size_t size = lc->bitset_uint32_count * sizeof(uint32_t); 595 596 /* read the disk header */ 597 r = read_header(lc); 598 if (r) { 599 DMWARN("%s: Failed to read header on dirty region log device", 600 lc->log_dev->name); 601 fail_log_device(lc); 602 /* 603 * If the log device cannot be read, we must assume 604 * all regions are out-of-sync. If we simply return 605 * here, the state will be uninitialized and could 606 * lead us to return 'in-sync' status for regions 607 * that are actually 'out-of-sync'. 608 */ 609 lc->header.nr_regions = 0; 610 } 611 612 /* set or clear any new bits -- device has grown */ 613 if (lc->sync == NOSYNC) 614 for (i = lc->header.nr_regions; i < lc->region_count; i++) 615 /* FIXME: amazingly inefficient */ 616 log_set_bit(lc, lc->clean_bits, i); 617 else 618 for (i = lc->header.nr_regions; i < lc->region_count; i++) 619 /* FIXME: amazingly inefficient */ 620 log_clear_bit(lc, lc->clean_bits, i); 621 622 /* clear any old bits -- device has shrunk */ 623 for (i = lc->region_count; i % (sizeof(*lc->clean_bits) << BYTE_SHIFT); i++) 624 log_clear_bit(lc, lc->clean_bits, i); 625 626 /* copy clean across to sync */ 627 memcpy(lc->sync_bits, lc->clean_bits, size); 628 lc->sync_count = count_bits32(lc->clean_bits, lc->bitset_uint32_count); 629 lc->sync_search = 0; 630 631 /* set the correct number of regions in the header */ 632 lc->header.nr_regions = lc->region_count; 633 634 /* write the new header */ 635 r = write_header(lc); 636 if (r) { 637 DMWARN("%s: Failed to write header on dirty region log device", 638 lc->log_dev->name); 639 fail_log_device(lc); 640 } 641 642 return r; 643 } 644 645 static uint32_t core_get_region_size(struct dm_dirty_log *log) 646 { 647 struct log_c *lc = (struct log_c *) log->context; 648 return lc->region_size; 649 } 650 651 static int core_resume(struct dm_dirty_log *log) 652 { 653 struct log_c *lc = (struct log_c *) log->context; 654 lc->sync_search = 0; 655 return 0; 656 } 657 658 static int core_is_clean(struct dm_dirty_log *log, region_t region) 659 { 660 struct log_c *lc = (struct log_c *) log->context; 661 return log_test_bit(lc->clean_bits, region); 662 } 663 664 static int core_in_sync(struct dm_dirty_log *log, region_t region, int block) 665 { 666 struct log_c *lc = (struct log_c *) log->context; 667 return log_test_bit(lc->sync_bits, region); 668 } 669 670 static int core_flush(struct dm_dirty_log *log) 671 { 672 /* no op */ 673 return 0; 674 } 675 676 static int disk_flush(struct dm_dirty_log *log) 677 { 678 int r; 679 struct log_c *lc = (struct log_c *) log->context; 680 681 /* only write if the log has changed */ 682 if (!lc->touched) 683 return 0; 684 685 r = write_header(lc); 686 if (r) 687 fail_log_device(lc); 688 else 689 lc->touched = 0; 690 691 return r; 692 } 693 694 static void core_mark_region(struct dm_dirty_log *log, region_t region) 695 { 696 struct log_c *lc = (struct log_c *) log->context; 697 log_clear_bit(lc, lc->clean_bits, region); 698 } 699 700 static void core_clear_region(struct dm_dirty_log *log, region_t region) 701 { 702 struct log_c *lc = (struct log_c *) log->context; 703 log_set_bit(lc, lc->clean_bits, region); 704 } 705 706 static int core_get_resync_work(struct dm_dirty_log *log, region_t *region) 707 { 708 struct log_c *lc = (struct log_c *) log->context; 709 710 if (lc->sync_search >= lc->region_count) 711 return 0; 712 713 do { 714 *region = ext2_find_next_zero_bit( 715 (unsigned long *) lc->sync_bits, 716 lc->region_count, 717 lc->sync_search); 718 lc->sync_search = *region + 1; 719 720 if (*region >= lc->region_count) 721 return 0; 722 723 } while (log_test_bit(lc->recovering_bits, *region)); 724 725 log_set_bit(lc, lc->recovering_bits, *region); 726 return 1; 727 } 728 729 static void core_set_region_sync(struct dm_dirty_log *log, region_t region, 730 int in_sync) 731 { 732 struct log_c *lc = (struct log_c *) log->context; 733 734 log_clear_bit(lc, lc->recovering_bits, region); 735 if (in_sync) { 736 log_set_bit(lc, lc->sync_bits, region); 737 lc->sync_count++; 738 } else if (log_test_bit(lc->sync_bits, region)) { 739 lc->sync_count--; 740 log_clear_bit(lc, lc->sync_bits, region); 741 } 742 } 743 744 static region_t core_get_sync_count(struct dm_dirty_log *log) 745 { 746 struct log_c *lc = (struct log_c *) log->context; 747 748 return lc->sync_count; 749 } 750 751 #define DMEMIT_SYNC \ 752 if (lc->sync != DEFAULTSYNC) \ 753 DMEMIT("%ssync ", lc->sync == NOSYNC ? "no" : "") 754 755 static int core_status(struct dm_dirty_log *log, status_type_t status, 756 char *result, unsigned int maxlen) 757 { 758 int sz = 0; 759 struct log_c *lc = log->context; 760 761 switch(status) { 762 case STATUSTYPE_INFO: 763 DMEMIT("1 %s", log->type->name); 764 break; 765 766 case STATUSTYPE_TABLE: 767 DMEMIT("%s %u %u ", log->type->name, 768 lc->sync == DEFAULTSYNC ? 1 : 2, lc->region_size); 769 DMEMIT_SYNC; 770 } 771 772 return sz; 773 } 774 775 static int disk_status(struct dm_dirty_log *log, status_type_t status, 776 char *result, unsigned int maxlen) 777 { 778 int sz = 0; 779 struct log_c *lc = log->context; 780 781 switch(status) { 782 case STATUSTYPE_INFO: 783 DMEMIT("3 %s %s %c", log->type->name, lc->log_dev->name, 784 lc->log_dev_failed ? 'D' : 'A'); 785 break; 786 787 case STATUSTYPE_TABLE: 788 DMEMIT("%s %u %s %u ", log->type->name, 789 lc->sync == DEFAULTSYNC ? 2 : 3, lc->log_dev->name, 790 lc->region_size); 791 DMEMIT_SYNC; 792 } 793 794 return sz; 795 } 796 797 static struct dm_dirty_log_type _core_type = { 798 .name = "core", 799 .module = THIS_MODULE, 800 .ctr = core_ctr, 801 .dtr = core_dtr, 802 .resume = core_resume, 803 .get_region_size = core_get_region_size, 804 .is_clean = core_is_clean, 805 .in_sync = core_in_sync, 806 .flush = core_flush, 807 .mark_region = core_mark_region, 808 .clear_region = core_clear_region, 809 .get_resync_work = core_get_resync_work, 810 .set_region_sync = core_set_region_sync, 811 .get_sync_count = core_get_sync_count, 812 .status = core_status, 813 }; 814 815 static struct dm_dirty_log_type _disk_type = { 816 .name = "disk", 817 .module = THIS_MODULE, 818 .ctr = disk_ctr, 819 .dtr = disk_dtr, 820 .postsuspend = disk_flush, 821 .resume = disk_resume, 822 .get_region_size = core_get_region_size, 823 .is_clean = core_is_clean, 824 .in_sync = core_in_sync, 825 .flush = disk_flush, 826 .mark_region = core_mark_region, 827 .clear_region = core_clear_region, 828 .get_resync_work = core_get_resync_work, 829 .set_region_sync = core_set_region_sync, 830 .get_sync_count = core_get_sync_count, 831 .status = disk_status, 832 }; 833 834 int __init dm_dirty_log_init(void) 835 { 836 int r; 837 838 r = dm_dirty_log_type_register(&_core_type); 839 if (r) 840 DMWARN("couldn't register core log"); 841 842 r = dm_dirty_log_type_register(&_disk_type); 843 if (r) { 844 DMWARN("couldn't register disk type"); 845 dm_dirty_log_type_unregister(&_core_type); 846 } 847 848 return r; 849 } 850 851 void __exit dm_dirty_log_exit(void) 852 { 853 dm_dirty_log_type_unregister(&_disk_type); 854 dm_dirty_log_type_unregister(&_core_type); 855 } 856 857 module_init(dm_dirty_log_init); 858 module_exit(dm_dirty_log_exit); 859 860 MODULE_DESCRIPTION(DM_NAME " dirty region log"); 861 MODULE_AUTHOR("Joe Thornber, Heinz Mauelshagen <dm-devel@redhat.com>"); 862 MODULE_LICENSE("GPL"); 863