drivers/md/dm-log.c

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