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 #include <linux/dm-io.h>
  13 #include <linux/dm-dirty-log.h>
  14
  15 #include <linux/device-mapper.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 *__find_dirty_log_type(const char *name)
  23 {
  24         struct dm_dirty_log_type *log_type;
  25
  26         list_for_each_entry(log_type, &_log_types, list)
  27                 if (!strcmp(name, log_type->name))
  28                         return log_type;
  29
  30         return NULL;
  31 }
  32
  33 static struct dm_dirty_log_type *_get_dirty_log_type(const char *name)
  34 {
  35         struct dm_dirty_log_type *log_type;
  36
  37         spin_lock(&_lock);
  38
  39         log_type = __find_dirty_log_type(name);
  40         if (log_type && !try_module_get(log_type->module))
  41                 log_type = NULL;
  42
  43         spin_unlock(&_lock);
  44
  45         return log_type;
  46 }
  47
  48 /*
  49  * get_type
  50  * @type_name
  51  *
  52  * Attempt to retrieve the dm_dirty_log_type by name.  If not already
  53  * available, attempt to load the appropriate module.
  54  *
  55  * Log modules are named "dm-log-" followed by the 'type_name'.
  56  * Modules may contain multiple types.
  57  * This function will first try the module "dm-log-<type_name>",
  58  * then truncate 'type_name' on the last '-' and try again.
  59  *
  60  * For example, if type_name was "clustered-disk", it would search
  61  * 'dm-log-clustered-disk' then 'dm-log-clustered'.
  62  *
  63  * Returns: dirty_log_type* on success, NULL on failure
  64  */
  65 static struct dm_dirty_log_type *get_type(const char *type_name)
  66 {
  67         char *p, *type_name_dup;
  68         struct dm_dirty_log_type *log_type;
  69
  70         if (!type_name)
  71                 return NULL;
  72
  73         log_type = _get_dirty_log_type(type_name);
  74         if (log_type)
  75                 return log_type;
  76
  77         type_name_dup = kstrdup(type_name, GFP_KERNEL);
  78         if (!type_name_dup) {
  79                 DMWARN("No memory left to attempt log module load for \"%s\"",
  80                        type_name);
  81                 return NULL;
  82         }
  83
  84         while (request_module("dm-log-%s", type_name_dup) ||
  85                !(log_type = _get_dirty_log_type(type_name))) {
  86                 p = strrchr(type_name_dup, '-');
  87                 if (!p)
  88                         break;
  89                 p[0] = '\0';
  90         }
  91
  92         if (!log_type)
  93                 DMWARN("Module for logging type \"%s\" not found.", type_name);
  94
  95         kfree(type_name_dup);
  96
  97         return log_type;
  98 }
  99
 100 static void put_type(struct dm_dirty_log_type *type)
 101 {
 102         if (!type)
 103                 return;
 104
 105         spin_lock(&_lock);
 106         if (!__find_dirty_log_type(type->name))
 107                 goto out;
 108
 109         module_put(type->module);
 110
 111 out:
 112         spin_unlock(&_lock);
 113 }
 114
 115 int dm_dirty_log_type_register(struct dm_dirty_log_type *type)
 116 {
 117         int r = 0;
 118
 119         spin_lock(&_lock);
 120         if (!__find_dirty_log_type(type->name))
 121                 list_add(&type->list, &_log_types);
 122         else
 123                 r = -EEXIST;
 124         spin_unlock(&_lock);
 125
 126         return r;
 127 }
 128 EXPORT_SYMBOL(dm_dirty_log_type_register);
 129
 130 int dm_dirty_log_type_unregister(struct dm_dirty_log_type *type)
 131 {
 132         spin_lock(&_lock);
 133
 134         if (!__find_dirty_log_type(type->name)) {
 135                 spin_unlock(&_lock);
 136                 return -EINVAL;
 137         }
 138
 139         list_del(&type->list);
 140
 141         spin_unlock(&_lock);
 142
 143         return 0;
 144 }
 145 EXPORT_SYMBOL(dm_dirty_log_type_unregister);
 146
 147 struct dm_dirty_log *dm_dirty_log_create(const char *type_name,
 148                                          struct dm_target *ti,
 149                                          unsigned int argc, char **argv)
 150 {
 151         struct dm_dirty_log_type *type;
 152         struct dm_dirty_log *log;
 153
 154         log = kmalloc(sizeof(*log), GFP_KERNEL);
 155         if (!log)
 156                 return NULL;
 157
 158         type = get_type(type_name);
 159         if (!type) {
 160                 kfree(log);
 161                 return NULL;
 162         }
 163
 164         log->type = type;
 165         if (type->ctr(log, ti, argc, argv)) {
 166                 kfree(log);
 167                 put_type(type);
 168                 return NULL;
 169         }
 170
 171         return log;
 172 }
 173 EXPORT_SYMBOL(dm_dirty_log_create);
 174
 175 void dm_dirty_log_destroy(struct dm_dirty_log *log)
 176 {
 177         log->type->dtr(log);
 178         put_type(log->type);
 179         kfree(log);
 180 }
 181 EXPORT_SYMBOL(dm_dirty_log_destroy);
 182
 183 /*-----------------------------------------------------------------
 184  * Persistent and core logs share a lot of their implementation.
 185  * FIXME: need a reload method to be called from a resume
 186  *---------------------------------------------------------------*/
 187 /*
 188  * Magic for persistent mirrors: "MiRr"
 189  */
 190 #define MIRROR_MAGIC 0x4D695272
 191
 192 /*
 193  * The on-disk version of the metadata.
 194  */
 195 #define MIRROR_DISK_VERSION 2
 196 #define LOG_OFFSET 2
 197
 198 struct log_header {
 199         uint32_t magic;
 200
 201         /*
 202          * Simple, incrementing version. no backward
 203          * compatibility.
 204          */
 205         uint32_t version;
 206         sector_t nr_regions;
 207 };
 208
 209 struct log_c {
 210         struct dm_target *ti;
 211         int touched_dirtied;
 212         int touched_cleaned;
 213         uint32_t region_size;
 214         unsigned int region_count;
 215         region_t sync_count;
 216
 217         unsigned bitset_uint32_count;
 218         uint32_t *clean_bits;
 219         uint32_t *sync_bits;
 220         uint32_t *recovering_bits;      /* FIXME: this seems excessive */
 221
 222         int sync_search;
 223
 224         /* Resync flag */
 225         enum sync {
 226                 DEFAULTSYNC,    /* Synchronize if necessary */
 227                 NOSYNC,         /* Devices known to be already in sync */
 228                 FORCESYNC,      /* Force a sync to happen */
 229         } sync;
 230
 231         struct dm_io_request io_req;
 232
 233         /*
 234          * Disk log fields
 235          */
 236         int log_dev_failed;
 237         struct dm_dev *log_dev;
 238         struct log_header header;
 239
 240         struct dm_io_region header_location;
 241         struct log_header *disk_header;
 242 };
 243
 244 /*
 245  * The touched member needs to be updated every time we access
 246  * one of the bitsets.
 247  */
 248 static inline int log_test_bit(uint32_t *bs, unsigned bit)
 249 {
 250         return ext2_test_bit(bit, (unsigned long *) bs) ? 1 : 0;
 251 }
 252
 253 static inline void log_set_bit(struct log_c *l,
 254                                uint32_t *bs, unsigned bit)
 255 {
 256         ext2_set_bit(bit, (unsigned long *) bs);
 257         l->touched_cleaned = 1;
 258 }
 259
 260 static inline void log_clear_bit(struct log_c *l,
 261                                  uint32_t *bs, unsigned bit)
 262 {
 263         ext2_clear_bit(bit, (unsigned long *) bs);
 264         l->touched_dirtied = 1;
 265 }
 266
 267 /*----------------------------------------------------------------
 268  * Header IO
 269  *--------------------------------------------------------------*/
 270 static void header_to_disk(struct log_header *core, struct log_header *disk)
 271 {
 272         disk->magic = cpu_to_le32(core->magic);
 273         disk->version = cpu_to_le32(core->version);
 274         disk->nr_regions = cpu_to_le64(core->nr_regions);
 275 }
 276
 277 static void header_from_disk(struct log_header *core, struct log_header *disk)
 278 {
 279         core->magic = le32_to_cpu(disk->magic);
 280         core->version = le32_to_cpu(disk->version);
 281         core->nr_regions = le64_to_cpu(disk->nr_regions);
 282 }
 283
 284 static int rw_header(struct log_c *lc, int rw)
 285 {
 286         lc->io_req.bi_rw = rw;
 287
 288         return dm_io(&lc->io_req, 1, &lc->header_location, NULL);
 289 }
 290
 291 static int read_header(struct log_c *log)
 292 {
 293         int r;
 294
 295         r = rw_header(log, READ);
 296         if (r)
 297                 return r;
 298
 299         header_from_disk(&log->header, log->disk_header);
 300
 301         /* New log required? */
 302         if (log->sync != DEFAULTSYNC || log->header.magic != MIRROR_MAGIC) {
 303                 log->header.magic = MIRROR_MAGIC;
 304                 log->header.version = MIRROR_DISK_VERSION;
 305                 log->header.nr_regions = 0;
 306         }
 307
 308 #ifdef __LITTLE_ENDIAN
 309         if (log->header.version == 1)
 310                 log->header.version = 2;
 311 #endif
 312
 313         if (log->header.version != MIRROR_DISK_VERSION) {
 314                 DMWARN("incompatible disk log version");
 315                 return -EINVAL;
 316         }
 317
 318         return 0;
 319 }
 320
 321 static int _check_region_size(struct dm_target *ti, uint32_t region_size)
 322 {
 323         if (region_size < 2 || region_size > ti->len)
 324                 return 0;
 325
 326         if (!is_power_of_2(region_size))
 327                 return 0;
 328
 329         return 1;
 330 }
 331
 332 /*----------------------------------------------------------------
 333  * core log constructor/destructor
 334  *
 335  * argv contains region_size followed optionally by [no]sync
 336  *--------------------------------------------------------------*/
 337 #define BYTE_SHIFT 3
 338 static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti,
 339                               unsigned int argc, char **argv,
 340                               struct dm_dev *dev)
 341 {
 342         enum sync sync = DEFAULTSYNC;
 343
 344         struct log_c *lc;
 345         uint32_t region_size;
 346         unsigned int region_count;
 347         size_t bitset_size, buf_size;
 348         int r;
 349
 350         if (argc < 1 || argc > 2) {
 351                 DMWARN("wrong number of arguments to dirty region log");
 352                 return -EINVAL;
 353         }
 354
 355         if (argc > 1) {
 356                 if (!strcmp(argv[1], "sync"))
 357                         sync = FORCESYNC;
 358                 else if (!strcmp(argv[1], "nosync"))
 359                         sync = NOSYNC;
 360                 else {
 361                         DMWARN("unrecognised sync argument to "
 362                                "dirty region log: %s", argv[1]);
 363                         return -EINVAL;
 364                 }
 365         }
 366
 367         if (sscanf(argv[0], "%u", &region_size) != 1 ||
 368             !_check_region_size(ti, region_size)) {
 369                 DMWARN("invalid region size %s", argv[0]);
 370                 return -EINVAL;
 371         }
 372
 373         region_count = dm_sector_div_up(ti->len, region_size);
 374
 375         lc = kmalloc(sizeof(*lc), GFP_KERNEL);
 376         if (!lc) {
 377                 DMWARN("couldn't allocate core log");
 378                 return -ENOMEM;
 379         }
 380
 381         lc->ti = ti;
 382         lc->touched_dirtied = 0;
 383         lc->touched_cleaned = 0;
 384         lc->region_size = region_size;
 385         lc->region_count = region_count;
 386         lc->sync = sync;
 387
 388         /*
 389          * Work out how many "unsigned long"s we need to hold the bitset.
 390          */
 391         bitset_size = dm_round_up(region_count,
 392                                   sizeof(*lc->clean_bits) << BYTE_SHIFT);
 393         bitset_size >>= BYTE_SHIFT;
 394
 395         lc->bitset_uint32_count = bitset_size / sizeof(*lc->clean_bits);
 396
 397         /*
 398          * Disk log?
 399          */
 400         if (!dev) {
 401                 lc->clean_bits = vmalloc(bitset_size);
 402                 if (!lc->clean_bits) {
 403                         DMWARN("couldn't allocate clean bitset");
 404                         kfree(lc);
 405                         return -ENOMEM;
 406                 }
 407                 lc->disk_header = NULL;
 408         } else {
 409                 lc->log_dev = dev;
 410                 lc->log_dev_failed = 0;
 411                 lc->header_location.bdev = lc->log_dev->bdev;
 412                 lc->header_location.sector = 0;
 413
 414                 /*
 415                  * Buffer holds both header and bitset.
 416                  */
 417                 buf_size =
 418                     dm_round_up((LOG_OFFSET << SECTOR_SHIFT) + bitset_size,
 419                                 bdev_logical_block_size(lc->header_location.
 420                                                             bdev));
 421
 422                 if (buf_size > i_size_read(dev->bdev->bd_inode)) {
 423                         DMWARN("log device %s too small: need %llu bytes",
 424                                 dev->name, (unsigned long long)buf_size);
 425                         kfree(lc);
 426                         return -EINVAL;
 427                 }
 428
 429                 lc->header_location.count = buf_size >> SECTOR_SHIFT;
 430
 431                 lc->io_req.mem.type = DM_IO_VMA;
 432                 lc->io_req.notify.fn = NULL;
 433                 lc->io_req.client = dm_io_client_create(dm_div_up(buf_size,
 434                                                                    PAGE_SIZE));
 435                 if (IS_ERR(lc->io_req.client)) {
 436                         r = PTR_ERR(lc->io_req.client);
 437                         DMWARN("couldn't allocate disk io client");
 438                         kfree(lc);
 439                         return -ENOMEM;
 440                 }
 441
 442                 lc->disk_header = vmalloc(buf_size);
 443                 if (!lc->disk_header) {
 444                         DMWARN("couldn't allocate disk log buffer");
 445                         dm_io_client_destroy(lc->io_req.client);
 446                         kfree(lc);
 447                         return -ENOMEM;
 448                 }
 449
 450                 lc->io_req.mem.ptr.vma = lc->disk_header;
 451                 lc->clean_bits = (void *)lc->disk_header +
 452                                  (LOG_OFFSET << SECTOR_SHIFT);
 453         }
 454
 455         memset(lc->clean_bits, -1, bitset_size);
 456
 457         lc->sync_bits = vmalloc(bitset_size);
 458         if (!lc->sync_bits) {
 459                 DMWARN("couldn't allocate sync bitset");
 460                 if (!dev)
 461                         vfree(lc->clean_bits);
 462                 else
 463                         dm_io_client_destroy(lc->io_req.client);
 464                 vfree(lc->disk_header);
 465                 kfree(lc);
 466                 return -ENOMEM;
 467         }
 468         memset(lc->sync_bits, (sync == NOSYNC) ? -1 : 0, bitset_size);
 469         lc->sync_count = (sync == NOSYNC) ? region_count : 0;
 470
 471         lc->recovering_bits = vmalloc(bitset_size);
 472         if (!lc->recovering_bits) {
 473                 DMWARN("couldn't allocate sync bitset");
 474                 vfree(lc->sync_bits);
 475                 if (!dev)
 476                         vfree(lc->clean_bits);
 477                 else
 478                         dm_io_client_destroy(lc->io_req.client);
 479                 vfree(lc->disk_header);
 480                 kfree(lc);
 481                 return -ENOMEM;
 482         }
 483         memset(lc->recovering_bits, 0, bitset_size);
 484         lc->sync_search = 0;
 485         log->context = lc;
 486
 487         return 0;
 488 }
 489
 490 static int core_ctr(struct dm_dirty_log *log, struct dm_target *ti,
 491                     unsigned int argc, char **argv)
 492 {
 493         return create_log_context(log, ti, argc, argv, NULL);
 494 }
 495
 496 static void destroy_log_context(struct log_c *lc)
 497 {
 498         vfree(lc->sync_bits);
 499         vfree(lc->recovering_bits);
 500         kfree(lc);
 501 }
 502
 503 static void core_dtr(struct dm_dirty_log *log)
 504 {
 505         struct log_c *lc = (struct log_c *) log->context;
 506
 507         vfree(lc->clean_bits);
 508         destroy_log_context(lc);
 509 }
 510
 511 /*----------------------------------------------------------------
 512  * disk log constructor/destructor
 513  *
 514  * argv contains log_device region_size followed optionally by [no]sync
 515  *--------------------------------------------------------------*/
 516 static int disk_ctr(struct dm_dirty_log *log, struct dm_target *ti,
 517                     unsigned int argc, char **argv)
 518 {
 519         int r;
 520         struct dm_dev *dev;
 521
 522         if (argc < 2 || argc > 3) {
 523                 DMWARN("wrong number of arguments to disk dirty region log");
 524                 return -EINVAL;
 525         }
 526
 527         r = dm_get_device(ti, argv[0], 0, 0 /* FIXME */,
 528                           FMODE_READ | FMODE_WRITE, &dev);
 529         if (r)
 530                 return r;
 531
 532         r = create_log_context(log, ti, argc - 1, argv + 1, dev);
 533         if (r) {
 534                 dm_put_device(ti, dev);
 535                 return r;
 536         }
 537
 538         return 0;
 539 }
 540
 541 static void disk_dtr(struct dm_dirty_log *log)
 542 {
 543         struct log_c *lc = (struct log_c *) log->context;
 544
 545         dm_put_device(lc->ti, lc->log_dev);
 546         vfree(lc->disk_header);
 547         dm_io_client_destroy(lc->io_req.client);
 548         destroy_log_context(lc);
 549 }
 550
 551 static int count_bits32(uint32_t *addr, unsigned size)
 552 {
 553         int count = 0, i;
 554
 555         for (i = 0; i < size; i++) {
 556                 count += hweight32(*(addr+i));
 557         }
 558         return count;
 559 }
 560
 561 static void fail_log_device(struct log_c *lc)
 562 {
 563         if (lc->log_dev_failed)
 564                 return;
 565
 566         lc->log_dev_failed = 1;
 567         dm_table_event(lc->ti->table);
 568 }
 569
 570 static int disk_resume(struct dm_dirty_log *log)
 571 {
 572         int r;
 573         unsigned i;
 574         struct log_c *lc = (struct log_c *) log->context;
 575         size_t size = lc->bitset_uint32_count * sizeof(uint32_t);
 576
 577         /* read the disk header */
 578         r = read_header(lc);
 579         if (r) {
 580                 DMWARN("%s: Failed to read header on dirty region log device",
 581                        lc->log_dev->name);
 582                 fail_log_device(lc);
 583                 /*
 584                  * If the log device cannot be read, we must assume
 585                  * all regions are out-of-sync.  If we simply return
 586                  * here, the state will be uninitialized and could
 587                  * lead us to return 'in-sync' status for regions
 588                  * that are actually 'out-of-sync'.
 589                  */
 590                 lc->header.nr_regions = 0;
 591         }
 592
 593         /* set or clear any new bits -- device has grown */
 594         if (lc->sync == NOSYNC)
 595                 for (i = lc->header.nr_regions; i < lc->region_count; i++)
 596                         /* FIXME: amazingly inefficient */
 597                         log_set_bit(lc, lc->clean_bits, i);
 598         else
 599                 for (i = lc->header.nr_regions; i < lc->region_count; i++)
 600                         /* FIXME: amazingly inefficient */
 601                         log_clear_bit(lc, lc->clean_bits, i);
 602
 603         /* clear any old bits -- device has shrunk */
 604         for (i = lc->region_count; i % (sizeof(*lc->clean_bits) << BYTE_SHIFT); i++)
 605                 log_clear_bit(lc, lc->clean_bits, i);
 606
 607         /* copy clean across to sync */
 608         memcpy(lc->sync_bits, lc->clean_bits, size);
 609         lc->sync_count = count_bits32(lc->clean_bits, lc->bitset_uint32_count);
 610         lc->sync_search = 0;
 611
 612         /* set the correct number of regions in the header */
 613         lc->header.nr_regions = lc->region_count;
 614
 615         header_to_disk(&lc->header, lc->disk_header);
 616
 617         /* write the new header */
 618         r = rw_header(lc, WRITE);
 619         if (r) {
 620                 DMWARN("%s: Failed to write header on dirty region log device",
 621                        lc->log_dev->name);
 622                 fail_log_device(lc);
 623         }
 624
 625         return r;
 626 }
 627
 628 static uint32_t core_get_region_size(struct dm_dirty_log *log)
 629 {
 630         struct log_c *lc = (struct log_c *) log->context;
 631         return lc->region_size;
 632 }
 633
 634 static int core_resume(struct dm_dirty_log *log)
 635 {
 636         struct log_c *lc = (struct log_c *) log->context;
 637         lc->sync_search = 0;
 638         return 0;
 639 }
 640
 641 static int core_is_clean(struct dm_dirty_log *log, region_t region)
 642 {
 643         struct log_c *lc = (struct log_c *) log->context;
 644         return log_test_bit(lc->clean_bits, region);
 645 }
 646
 647 static int core_in_sync(struct dm_dirty_log *log, region_t region, int block)
 648 {
 649         struct log_c *lc = (struct log_c *) log->context;
 650         return log_test_bit(lc->sync_bits, region);
 651 }
 652
 653 static int core_flush(struct dm_dirty_log *log)
 654 {
 655         /* no op */
 656         return 0;
 657 }
 658
 659 static int disk_flush(struct dm_dirty_log *log)
 660 {
 661         int r;
 662         struct log_c *lc = (struct log_c *) log->context;
 663
 664         /* only write if the log has changed */
 665         if (!lc->touched_cleaned && !lc->touched_dirtied)
 666                 return 0;
 667
 668         r = rw_header(lc, WRITE);
 669         if (r)
 670                 fail_log_device(lc);
 671         else {
 672                 lc->touched_dirtied = 0;
 673                 lc->touched_cleaned = 0;
 674         }
 675
 676         return r;
 677 }
 678
 679 static void core_mark_region(struct dm_dirty_log *log, region_t region)
 680 {
 681         struct log_c *lc = (struct log_c *) log->context;
 682         log_clear_bit(lc, lc->clean_bits, region);
 683 }
 684
 685 static void core_clear_region(struct dm_dirty_log *log, region_t region)
 686 {
 687         struct log_c *lc = (struct log_c *) log->context;
 688         log_set_bit(lc, lc->clean_bits, region);
 689 }
 690
 691 static int core_get_resync_work(struct dm_dirty_log *log, region_t *region)
 692 {
 693         struct log_c *lc = (struct log_c *) log->context;
 694
 695         if (lc->sync_search >= lc->region_count)
 696                 return 0;
 697
 698         do {
 699                 *region = ext2_find_next_zero_bit(
 700                                              (unsigned long *) lc->sync_bits,
 701                                              lc->region_count,
 702                                              lc->sync_search);
 703                 lc->sync_search = *region + 1;
 704
 705                 if (*region >= lc->region_count)
 706                         return 0;
 707
 708         } while (log_test_bit(lc->recovering_bits, *region));
 709
 710         log_set_bit(lc, lc->recovering_bits, *region);
 711         return 1;
 712 }
 713
 714 static void core_set_region_sync(struct dm_dirty_log *log, region_t region,
 715                                  int in_sync)
 716 {
 717         struct log_c *lc = (struct log_c *) log->context;
 718
 719         log_clear_bit(lc, lc->recovering_bits, region);
 720         if (in_sync) {
 721                 log_set_bit(lc, lc->sync_bits, region);
 722                 lc->sync_count++;
 723         } else if (log_test_bit(lc->sync_bits, region)) {
 724                 lc->sync_count--;
 725                 log_clear_bit(lc, lc->sync_bits, region);
 726         }
 727 }
 728
 729 static region_t core_get_sync_count(struct dm_dirty_log *log)
 730 {
 731         struct log_c *lc = (struct log_c *) log->context;
 732
 733         return lc->sync_count;
 734 }
 735
 736 #define DMEMIT_SYNC \
 737         if (lc->sync != DEFAULTSYNC) \
 738                 DMEMIT("%ssync ", lc->sync == NOSYNC ? "no" : "")
 739
 740 static int core_status(struct dm_dirty_log *log, status_type_t status,
 741                        char *result, unsigned int maxlen)
 742 {
 743         int sz = 0;
 744         struct log_c *lc = log->context;
 745
 746         switch(status) {
 747         case STATUSTYPE_INFO:
 748                 DMEMIT("1 %s", log->type->name);
 749                 break;
 750
 751         case STATUSTYPE_TABLE:
 752                 DMEMIT("%s %u %u ", log->type->name,
 753                        lc->sync == DEFAULTSYNC ? 1 : 2, lc->region_size);
 754                 DMEMIT_SYNC;
 755         }
 756
 757         return sz;
 758 }
 759
 760 static int disk_status(struct dm_dirty_log *log, status_type_t status,
 761                        char *result, unsigned int maxlen)
 762 {
 763         int sz = 0;
 764         struct log_c *lc = log->context;
 765
 766         switch(status) {
 767         case STATUSTYPE_INFO:
 768                 DMEMIT("3 %s %s %c", log->type->name, lc->log_dev->name,
 769                        lc->log_dev_failed ? 'D' : 'A');
 770                 break;
 771
 772         case STATUSTYPE_TABLE:
 773                 DMEMIT("%s %u %s %u ", log->type->name,
 774                        lc->sync == DEFAULTSYNC ? 2 : 3, lc->log_dev->name,
 775                        lc->region_size);
 776                 DMEMIT_SYNC;
 777         }
 778
 779         return sz;
 780 }
 781
 782 static struct dm_dirty_log_type _core_type = {
 783         .name = "core",
 784         .module = THIS_MODULE,
 785         .ctr = core_ctr,
 786         .dtr = core_dtr,
 787         .resume = core_resume,
 788         .get_region_size = core_get_region_size,
 789         .is_clean = core_is_clean,
 790         .in_sync = core_in_sync,
 791         .flush = core_flush,
 792         .mark_region = core_mark_region,
 793         .clear_region = core_clear_region,
 794         .get_resync_work = core_get_resync_work,
 795         .set_region_sync = core_set_region_sync,
 796         .get_sync_count = core_get_sync_count,
 797         .status = core_status,
 798 };
 799
 800 static struct dm_dirty_log_type _disk_type = {
 801         .name = "disk",
 802         .module = THIS_MODULE,
 803         .ctr = disk_ctr,
 804         .dtr = disk_dtr,
 805         .postsuspend = disk_flush,
 806         .resume = disk_resume,
 807         .get_region_size = core_get_region_size,
 808         .is_clean = core_is_clean,
 809         .in_sync = core_in_sync,
 810         .flush = disk_flush,
 811         .mark_region = core_mark_region,
 812         .clear_region = core_clear_region,
 813         .get_resync_work = core_get_resync_work,
 814         .set_region_sync = core_set_region_sync,
 815         .get_sync_count = core_get_sync_count,
 816         .status = disk_status,
 817 };
 818
 819 static int __init dm_dirty_log_init(void)
 820 {
 821         int r;
 822
 823         r = dm_dirty_log_type_register(&_core_type);
 824         if (r)
 825                 DMWARN("couldn't register core log");
 826
 827         r = dm_dirty_log_type_register(&_disk_type);
 828         if (r) {
 829                 DMWARN("couldn't register disk type");
 830                 dm_dirty_log_type_unregister(&_core_type);
 831         }
 832
 833         return r;
 834 }
 835
 836 static void __exit dm_dirty_log_exit(void)
 837 {
 838         dm_dirty_log_type_unregister(&_disk_type);
 839         dm_dirty_log_type_unregister(&_core_type);
 840 }
 841
 842 module_init(dm_dirty_log_init);
 843 module_exit(dm_dirty_log_exit);
 844
 845 MODULE_DESCRIPTION(DM_NAME " dirty region log");
 846 MODULE_AUTHOR("Joe Thornber, Heinz Mauelshagen <dm-devel@redhat.com>");
 847 MODULE_LICENSE("GPL");