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;
 212         uint32_t region_size;
 213         unsigned int region_count;
 214         region_t sync_count;
 215
 216         unsigned bitset_uint32_count;
 217         uint32_t *clean_bits;
 218         uint32_t *sync_bits;
 219         uint32_t *recovering_bits;      /* FIXME: this seems excessive */
 220
 221         int sync_search;
 222
 223         /* Resync flag */
 224         enum sync {
 225                 DEFAULTSYNC,    /* Synchronize if necessary */
 226                 NOSYNC,         /* Devices known to be already in sync */
 227                 FORCESYNC,      /* Force a sync to happen */
 228         } sync;
 229
 230         struct dm_io_request io_req;
 231
 232         /*
 233          * Disk log fields
 234          */
 235         int log_dev_failed;
 236         struct dm_dev *log_dev;
 237         struct log_header header;
 238
 239         struct dm_io_region header_location;
 240         struct log_header *disk_header;
 241 };
 242
 243 /*
 244  * The touched member needs to be updated every time we access
 245  * one of the bitsets.
 246  */
 247 static inline int log_test_bit(uint32_t *bs, unsigned bit)
 248 {
 249         return ext2_test_bit(bit, (unsigned long *) bs) ? 1 : 0;
 250 }
 251
 252 static inline void log_set_bit(struct log_c *l,
 253                                uint32_t *bs, unsigned bit)
 254 {
 255         ext2_set_bit(bit, (unsigned long *) bs);
 256         l->touched = 1;
 257 }
 258
 259 static inline void log_clear_bit(struct log_c *l,
 260                                  uint32_t *bs, unsigned bit)
 261 {
 262         ext2_clear_bit(bit, (unsigned long *) bs);
 263         l->touched = 1;
 264 }
 265
 266 /*----------------------------------------------------------------
 267  * Header IO
 268  *--------------------------------------------------------------*/
 269 static void header_to_disk(struct log_header *core, struct log_header *disk)
 270 {
 271         disk->magic = cpu_to_le32(core->magic);
 272         disk->version = cpu_to_le32(core->version);
 273         disk->nr_regions = cpu_to_le64(core->nr_regions);
 274 }
 275
 276 static void header_from_disk(struct log_header *core, struct log_header *disk)
 277 {
 278         core->magic = le32_to_cpu(disk->magic);
 279         core->version = le32_to_cpu(disk->version);
 280         core->nr_regions = le64_to_cpu(disk->nr_regions);
 281 }
 282
 283 static int rw_header(struct log_c *lc, int rw)
 284 {
 285         lc->io_req.bi_rw = rw;
 286
 287         return dm_io(&lc->io_req, 1, &lc->header_location, NULL);
 288 }
 289
 290 static int read_header(struct log_c *log)
 291 {
 292         int r;
 293
 294         r = rw_header(log, READ);
 295         if (r)
 296                 return r;
 297
 298         header_from_disk(&log->header, log->disk_header);
 299
 300         /* New log required? */
 301         if (log->sync != DEFAULTSYNC || log->header.magic != MIRROR_MAGIC) {
 302                 log->header.magic = MIRROR_MAGIC;
 303                 log->header.version = MIRROR_DISK_VERSION;
 304                 log->header.nr_regions = 0;
 305         }
 306
 307 #ifdef __LITTLE_ENDIAN
 308         if (log->header.version == 1)
 309                 log->header.version = 2;
 310 #endif
 311
 312         if (log->header.version != MIRROR_DISK_VERSION) {
 313                 DMWARN("incompatible disk log version");
 314                 return -EINVAL;
 315         }
 316
 317         return 0;
 318 }
 319
 320 static int _check_region_size(struct dm_target *ti, uint32_t region_size)
 321 {
 322         if (region_size < 2 || region_size > ti->len)
 323                 return 0;
 324
 325         if (!is_power_of_2(region_size))
 326                 return 0;
 327
 328         return 1;
 329 }
 330
 331 /*----------------------------------------------------------------
 332  * core log constructor/destructor
 333  *
 334  * argv contains region_size followed optionally by [no]sync
 335  *--------------------------------------------------------------*/
 336 #define BYTE_SHIFT 3
 337 static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti,
 338                               unsigned int argc, char **argv,
 339                               struct dm_dev *dev)
 340 {
 341         enum sync sync = DEFAULTSYNC;
 342
 343         struct log_c *lc;
 344         uint32_t region_size;
 345         unsigned int region_count;
 346         size_t bitset_size, buf_size;
 347         int r;
 348
 349         if (argc < 1 || argc > 2) {
 350                 DMWARN("wrong number of arguments to dirty region log");
 351                 return -EINVAL;
 352         }
 353
 354         if (argc > 1) {
 355                 if (!strcmp(argv[1], "sync"))
 356                         sync = FORCESYNC;
 357                 else if (!strcmp(argv[1], "nosync"))
 358                         sync = NOSYNC;
 359                 else {
 360                         DMWARN("unrecognised sync argument to "
 361                                "dirty region log: %s", argv[1]);
 362                         return -EINVAL;
 363                 }
 364         }
 365
 366         if (sscanf(argv[0], "%u", &region_size) != 1 ||
 367             !_check_region_size(ti, region_size)) {
 368                 DMWARN("invalid region size %s", argv[0]);
 369                 return -EINVAL;
 370         }
 371
 372         region_count = dm_sector_div_up(ti->len, region_size);
 373
 374         lc = kmalloc(sizeof(*lc), GFP_KERNEL);
 375         if (!lc) {
 376                 DMWARN("couldn't allocate core log");
 377                 return -ENOMEM;
 378         }
 379
 380         lc->ti = ti;
 381         lc->touched = 0;
 382         lc->region_size = region_size;
 383         lc->region_count = region_count;
 384         lc->sync = sync;
 385
 386         /*
 387          * Work out how many "unsigned long"s we need to hold the bitset.
 388          */
 389         bitset_size = dm_round_up(region_count,
 390                                   sizeof(*lc->clean_bits) << BYTE_SHIFT);
 391         bitset_size >>= BYTE_SHIFT;
 392
 393         lc->bitset_uint32_count = bitset_size / sizeof(*lc->clean_bits);
 394
 395         /*
 396          * Disk log?
 397          */
 398         if (!dev) {
 399                 lc->clean_bits = vmalloc(bitset_size);
 400                 if (!lc->clean_bits) {
 401                         DMWARN("couldn't allocate clean bitset");
 402                         kfree(lc);
 403                         return -ENOMEM;
 404                 }
 405                 lc->disk_header = NULL;
 406         } else {
 407                 lc->log_dev = dev;
 408                 lc->log_dev_failed = 0;
 409                 lc->header_location.bdev = lc->log_dev->bdev;
 410                 lc->header_location.sector = 0;
 411
 412                 /*
 413                  * Buffer holds both header and bitset.
 414                  */
 415                 buf_size = dm_round_up((LOG_OFFSET << SECTOR_SHIFT) +
 416                                        bitset_size, ti->limits.hardsect_size);
 417
 418                 if (buf_size > dev->bdev->bd_inode->i_size) {
 419                         DMWARN("log device %s too small: need %llu bytes",
 420                                 dev->name, (unsigned long long)buf_size);
 421                         kfree(lc);
 422                         return -EINVAL;
 423                 }
 424
 425                 lc->header_location.count = buf_size >> SECTOR_SHIFT;
 426
 427                 lc->io_req.mem.type = DM_IO_VMA;
 428                 lc->io_req.notify.fn = NULL;
 429                 lc->io_req.client = dm_io_client_create(dm_div_up(buf_size,
 430                                                                    PAGE_SIZE));
 431                 if (IS_ERR(lc->io_req.client)) {
 432                         r = PTR_ERR(lc->io_req.client);
 433                         DMWARN("couldn't allocate disk io client");
 434                         kfree(lc);
 435                         return -ENOMEM;
 436                 }
 437
 438                 lc->disk_header = vmalloc(buf_size);
 439                 if (!lc->disk_header) {
 440                         DMWARN("couldn't allocate disk log buffer");
 441                         dm_io_client_destroy(lc->io_req.client);
 442                         kfree(lc);
 443                         return -ENOMEM;
 444                 }
 445
 446                 lc->io_req.mem.ptr.vma = lc->disk_header;
 447                 lc->clean_bits = (void *)lc->disk_header +
 448                                  (LOG_OFFSET << SECTOR_SHIFT);
 449         }
 450
 451         memset(lc->clean_bits, -1, bitset_size);
 452
 453         lc->sync_bits = vmalloc(bitset_size);
 454         if (!lc->sync_bits) {
 455                 DMWARN("couldn't allocate sync bitset");
 456                 if (!dev)
 457                         vfree(lc->clean_bits);
 458                 else
 459                         dm_io_client_destroy(lc->io_req.client);
 460                 vfree(lc->disk_header);
 461                 kfree(lc);
 462                 return -ENOMEM;
 463         }
 464         memset(lc->sync_bits, (sync == NOSYNC) ? -1 : 0, bitset_size);
 465         lc->sync_count = (sync == NOSYNC) ? region_count : 0;
 466
 467         lc->recovering_bits = vmalloc(bitset_size);
 468         if (!lc->recovering_bits) {
 469                 DMWARN("couldn't allocate sync bitset");
 470                 vfree(lc->sync_bits);
 471                 if (!dev)
 472                         vfree(lc->clean_bits);
 473                 else
 474                         dm_io_client_destroy(lc->io_req.client);
 475                 vfree(lc->disk_header);
 476                 kfree(lc);
 477                 return -ENOMEM;
 478         }
 479         memset(lc->recovering_bits, 0, bitset_size);
 480         lc->sync_search = 0;
 481         log->context = lc;
 482
 483         return 0;
 484 }
 485
 486 static int core_ctr(struct dm_dirty_log *log, struct dm_target *ti,
 487                     unsigned int argc, char **argv)
 488 {
 489         return create_log_context(log, ti, argc, argv, NULL);
 490 }
 491
 492 static void destroy_log_context(struct log_c *lc)
 493 {
 494         vfree(lc->sync_bits);
 495         vfree(lc->recovering_bits);
 496         kfree(lc);
 497 }
 498
 499 static void core_dtr(struct dm_dirty_log *log)
 500 {
 501         struct log_c *lc = (struct log_c *) log->context;
 502
 503         vfree(lc->clean_bits);
 504         destroy_log_context(lc);
 505 }
 506
 507 /*----------------------------------------------------------------
 508  * disk log constructor/destructor
 509  *
 510  * argv contains log_device region_size followed optionally by [no]sync
 511  *--------------------------------------------------------------*/
 512 static int disk_ctr(struct dm_dirty_log *log, struct dm_target *ti,
 513                     unsigned int argc, char **argv)
 514 {
 515         int r;
 516         struct dm_dev *dev;
 517
 518         if (argc < 2 || argc > 3) {
 519                 DMWARN("wrong number of arguments to disk dirty region log");
 520                 return -EINVAL;
 521         }
 522
 523         r = dm_get_device(ti, argv[0], 0, 0 /* FIXME */,
 524                           FMODE_READ | FMODE_WRITE, &dev);
 525         if (r)
 526                 return r;
 527
 528         r = create_log_context(log, ti, argc - 1, argv + 1, dev);
 529         if (r) {
 530                 dm_put_device(ti, dev);
 531                 return r;
 532         }
 533
 534         return 0;
 535 }
 536
 537 static void disk_dtr(struct dm_dirty_log *log)
 538 {
 539         struct log_c *lc = (struct log_c *) log->context;
 540
 541         dm_put_device(lc->ti, lc->log_dev);
 542         vfree(lc->disk_header);
 543         dm_io_client_destroy(lc->io_req.client);
 544         destroy_log_context(lc);
 545 }
 546
 547 static int count_bits32(uint32_t *addr, unsigned size)
 548 {
 549         int count = 0, i;
 550
 551         for (i = 0; i < size; i++) {
 552                 count += hweight32(*(addr+i));
 553         }
 554         return count;
 555 }
 556
 557 static void fail_log_device(struct log_c *lc)
 558 {
 559         if (lc->log_dev_failed)
 560                 return;
 561
 562         lc->log_dev_failed = 1;
 563         dm_table_event(lc->ti->table);
 564 }
 565
 566 static int disk_resume(struct dm_dirty_log *log)
 567 {
 568         int r;
 569         unsigned i;
 570         struct log_c *lc = (struct log_c *) log->context;
 571         size_t size = lc->bitset_uint32_count * sizeof(uint32_t);
 572
 573         /* read the disk header */
 574         r = read_header(lc);
 575         if (r) {
 576                 DMWARN("%s: Failed to read header on dirty region log device",
 577                        lc->log_dev->name);
 578                 fail_log_device(lc);
 579                 /*
 580                  * If the log device cannot be read, we must assume
 581                  * all regions are out-of-sync.  If we simply return
 582                  * here, the state will be uninitialized and could
 583                  * lead us to return 'in-sync' status for regions
 584                  * that are actually 'out-of-sync'.
 585                  */
 586                 lc->header.nr_regions = 0;
 587         }
 588
 589         /* set or clear any new bits -- device has grown */
 590         if (lc->sync == NOSYNC)
 591                 for (i = lc->header.nr_regions; i < lc->region_count; i++)
 592                         /* FIXME: amazingly inefficient */
 593                         log_set_bit(lc, lc->clean_bits, i);
 594         else
 595                 for (i = lc->header.nr_regions; i < lc->region_count; i++)
 596                         /* FIXME: amazingly inefficient */
 597                         log_clear_bit(lc, lc->clean_bits, i);
 598
 599         /* clear any old bits -- device has shrunk */
 600         for (i = lc->region_count; i % (sizeof(*lc->clean_bits) << BYTE_SHIFT); i++)
 601                 log_clear_bit(lc, lc->clean_bits, i);
 602
 603         /* copy clean across to sync */
 604         memcpy(lc->sync_bits, lc->clean_bits, size);
 605         lc->sync_count = count_bits32(lc->clean_bits, lc->bitset_uint32_count);
 606         lc->sync_search = 0;
 607
 608         /* set the correct number of regions in the header */
 609         lc->header.nr_regions = lc->region_count;
 610
 611         header_to_disk(&lc->header, lc->disk_header);
 612
 613         /* write the new header */
 614         r = rw_header(lc, WRITE);
 615         if (r) {
 616                 DMWARN("%s: Failed to write header on dirty region log device",
 617                        lc->log_dev->name);
 618                 fail_log_device(lc);
 619         }
 620
 621         return r;
 622 }
 623
 624 static uint32_t core_get_region_size(struct dm_dirty_log *log)
 625 {
 626         struct log_c *lc = (struct log_c *) log->context;
 627         return lc->region_size;
 628 }
 629
 630 static int core_resume(struct dm_dirty_log *log)
 631 {
 632         struct log_c *lc = (struct log_c *) log->context;
 633         lc->sync_search = 0;
 634         return 0;
 635 }
 636
 637 static int core_is_clean(struct dm_dirty_log *log, region_t region)
 638 {
 639         struct log_c *lc = (struct log_c *) log->context;
 640         return log_test_bit(lc->clean_bits, region);
 641 }
 642
 643 static int core_in_sync(struct dm_dirty_log *log, region_t region, int block)
 644 {
 645         struct log_c *lc = (struct log_c *) log->context;
 646         return log_test_bit(lc->sync_bits, region);
 647 }
 648
 649 static int core_flush(struct dm_dirty_log *log)
 650 {
 651         /* no op */
 652         return 0;
 653 }
 654
 655 static int disk_flush(struct dm_dirty_log *log)
 656 {
 657         int r;
 658         struct log_c *lc = (struct log_c *) log->context;
 659
 660         /* only write if the log has changed */
 661         if (!lc->touched)
 662                 return 0;
 663
 664         r = rw_header(lc, WRITE);
 665         if (r)
 666                 fail_log_device(lc);
 667         else
 668                 lc->touched = 0;
 669
 670         return r;
 671 }
 672
 673 static void core_mark_region(struct dm_dirty_log *log, region_t region)
 674 {
 675         struct log_c *lc = (struct log_c *) log->context;
 676         log_clear_bit(lc, lc->clean_bits, region);
 677 }
 678
 679 static void core_clear_region(struct dm_dirty_log *log, region_t region)
 680 {
 681         struct log_c *lc = (struct log_c *) log->context;
 682         log_set_bit(lc, lc->clean_bits, region);
 683 }
 684
 685 static int core_get_resync_work(struct dm_dirty_log *log, region_t *region)
 686 {
 687         struct log_c *lc = (struct log_c *) log->context;
 688
 689         if (lc->sync_search >= lc->region_count)
 690                 return 0;
 691
 692         do {
 693                 *region = ext2_find_next_zero_bit(
 694                                              (unsigned long *) lc->sync_bits,
 695                                              lc->region_count,
 696                                              lc->sync_search);
 697                 lc->sync_search = *region + 1;
 698
 699                 if (*region >= lc->region_count)
 700                         return 0;
 701
 702         } while (log_test_bit(lc->recovering_bits, *region));
 703
 704         log_set_bit(lc, lc->recovering_bits, *region);
 705         return 1;
 706 }
 707
 708 static void core_set_region_sync(struct dm_dirty_log *log, region_t region,
 709                                  int in_sync)
 710 {
 711         struct log_c *lc = (struct log_c *) log->context;
 712
 713         log_clear_bit(lc, lc->recovering_bits, region);
 714         if (in_sync) {
 715                 log_set_bit(lc, lc->sync_bits, region);
 716                 lc->sync_count++;
 717         } else if (log_test_bit(lc->sync_bits, region)) {
 718                 lc->sync_count--;
 719                 log_clear_bit(lc, lc->sync_bits, region);
 720         }
 721 }
 722
 723 static region_t core_get_sync_count(struct dm_dirty_log *log)
 724 {
 725         struct log_c *lc = (struct log_c *) log->context;
 726
 727         return lc->sync_count;
 728 }
 729
 730 #define DMEMIT_SYNC \
 731         if (lc->sync != DEFAULTSYNC) \
 732                 DMEMIT("%ssync ", lc->sync == NOSYNC ? "no" : "")
 733
 734 static int core_status(struct dm_dirty_log *log, status_type_t status,
 735                        char *result, unsigned int maxlen)
 736 {
 737         int sz = 0;
 738         struct log_c *lc = log->context;
 739
 740         switch(status) {
 741         case STATUSTYPE_INFO:
 742                 DMEMIT("1 %s", log->type->name);
 743                 break;
 744
 745         case STATUSTYPE_TABLE:
 746                 DMEMIT("%s %u %u ", log->type->name,
 747                        lc->sync == DEFAULTSYNC ? 1 : 2, lc->region_size);
 748                 DMEMIT_SYNC;
 749         }
 750
 751         return sz;
 752 }
 753
 754 static int disk_status(struct dm_dirty_log *log, status_type_t status,
 755                        char *result, unsigned int maxlen)
 756 {
 757         int sz = 0;
 758         struct log_c *lc = log->context;
 759
 760         switch(status) {
 761         case STATUSTYPE_INFO:
 762                 DMEMIT("3 %s %s %c", log->type->name, lc->log_dev->name,
 763                        lc->log_dev_failed ? 'D' : 'A');
 764                 break;
 765
 766         case STATUSTYPE_TABLE:
 767                 DMEMIT("%s %u %s %u ", log->type->name,
 768                        lc->sync == DEFAULTSYNC ? 2 : 3, lc->log_dev->name,
 769                        lc->region_size);
 770                 DMEMIT_SYNC;
 771         }
 772
 773         return sz;
 774 }
 775
 776 static struct dm_dirty_log_type _core_type = {
 777         .name = "core",
 778         .module = THIS_MODULE,
 779         .ctr = core_ctr,
 780         .dtr = core_dtr,
 781         .resume = core_resume,
 782         .get_region_size = core_get_region_size,
 783         .is_clean = core_is_clean,
 784         .in_sync = core_in_sync,
 785         .flush = core_flush,
 786         .mark_region = core_mark_region,
 787         .clear_region = core_clear_region,
 788         .get_resync_work = core_get_resync_work,
 789         .set_region_sync = core_set_region_sync,
 790         .get_sync_count = core_get_sync_count,
 791         .status = core_status,
 792 };
 793
 794 static struct dm_dirty_log_type _disk_type = {
 795         .name = "disk",
 796         .module = THIS_MODULE,
 797         .ctr = disk_ctr,
 798         .dtr = disk_dtr,
 799         .postsuspend = disk_flush,
 800         .resume = disk_resume,
 801         .get_region_size = core_get_region_size,
 802         .is_clean = core_is_clean,
 803         .in_sync = core_in_sync,
 804         .flush = disk_flush,
 805         .mark_region = core_mark_region,
 806         .clear_region = core_clear_region,
 807         .get_resync_work = core_get_resync_work,
 808         .set_region_sync = core_set_region_sync,
 809         .get_sync_count = core_get_sync_count,
 810         .status = disk_status,
 811 };
 812
 813 static int __init dm_dirty_log_init(void)
 814 {
 815         int r;
 816
 817         r = dm_dirty_log_type_register(&_core_type);
 818         if (r)
 819                 DMWARN("couldn't register core log");
 820
 821         r = dm_dirty_log_type_register(&_disk_type);
 822         if (r) {
 823                 DMWARN("couldn't register disk type");
 824                 dm_dirty_log_type_unregister(&_core_type);
 825         }
 826
 827         return r;
 828 }
 829
 830 static void __exit dm_dirty_log_exit(void)
 831 {
 832         dm_dirty_log_type_unregister(&_disk_type);
 833         dm_dirty_log_type_unregister(&_core_type);
 834 }
 835
 836 module_init(dm_dirty_log_init);
 837 module_exit(dm_dirty_log_exit);
 838
 839 MODULE_DESCRIPTION(DM_NAME " dirty region log");
 840 MODULE_AUTHOR("Joe Thornber, Heinz Mauelshagen <dm-devel@redhat.com>");
 841 MODULE_LICENSE("GPL");