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         int flush_failed;
 214         uint32_t region_size;
 215         unsigned int region_count;
 216         region_t sync_count;
 217
 218         unsigned bitset_uint32_count;
 219         uint32_t *clean_bits;
 220         uint32_t *sync_bits;
 221         uint32_t *recovering_bits;      /* FIXME: this seems excessive */
 222
 223         int sync_search;
 224
 225         /* Resync flag */
 226         enum sync {
 227                 DEFAULTSYNC,    /* Synchronize if necessary */
 228                 NOSYNC,         /* Devices known to be already in sync */
 229                 FORCESYNC,      /* Force a sync to happen */
 230         } sync;
 231
 232         struct dm_io_request io_req;
 233
 234         /*
 235          * Disk log fields
 236          */
 237         int log_dev_failed;
 238         struct dm_dev *log_dev;
 239         struct log_header header;
 240
 241         struct dm_io_region header_location;
 242         struct log_header *disk_header;
 243 };
 244
 245 /*
 246  * The touched member needs to be updated every time we access
 247  * one of the bitsets.
 248  */
 249 static inline int log_test_bit(uint32_t *bs, unsigned bit)
 250 {
 251         return ext2_test_bit(bit, (unsigned long *) bs) ? 1 : 0;
 252 }
 253
 254 static inline void log_set_bit(struct log_c *l,
 255                                uint32_t *bs, unsigned bit)
 256 {
 257         ext2_set_bit(bit, (unsigned long *) bs);
 258         l->touched_cleaned = 1;
 259 }
 260
 261 static inline void log_clear_bit(struct log_c *l,
 262                                  uint32_t *bs, unsigned bit)
 263 {
 264         ext2_clear_bit(bit, (unsigned long *) bs);
 265         l->touched_dirtied = 1;
 266 }
 267
 268 /*----------------------------------------------------------------
 269  * Header IO
 270  *--------------------------------------------------------------*/
 271 static void header_to_disk(struct log_header *core, struct log_header *disk)
 272 {
 273         disk->magic = cpu_to_le32(core->magic);
 274         disk->version = cpu_to_le32(core->version);
 275         disk->nr_regions = cpu_to_le64(core->nr_regions);
 276 }
 277
 278 static void header_from_disk(struct log_header *core, struct log_header *disk)
 279 {
 280         core->magic = le32_to_cpu(disk->magic);
 281         core->version = le32_to_cpu(disk->version);
 282         core->nr_regions = le64_to_cpu(disk->nr_regions);
 283 }
 284
 285 static int rw_header(struct log_c *lc, int rw)
 286 {
 287         lc->io_req.bi_rw = rw;
 288
 289         return dm_io(&lc->io_req, 1, &lc->header_location, NULL);
 290 }
 291
 292 static int flush_header(struct log_c *lc)
 293 {
 294         struct dm_io_region null_location = {
 295                 .bdev = lc->header_location.bdev,
 296                 .sector = 0,
 297                 .count = 0,
 298         };
 299
 300         lc->io_req.bi_rw = WRITE_BARRIER;
 301
 302         return dm_io(&lc->io_req, 1, &null_location, NULL);
 303 }
 304
 305 static int read_header(struct log_c *log)
 306 {
 307         int r;
 308
 309         r = rw_header(log, READ);
 310         if (r)
 311                 return r;
 312
 313         header_from_disk(&log->header, log->disk_header);
 314
 315         /* New log required? */
 316         if (log->sync != DEFAULTSYNC || log->header.magic != MIRROR_MAGIC) {
 317                 log->header.magic = MIRROR_MAGIC;
 318                 log->header.version = MIRROR_DISK_VERSION;
 319                 log->header.nr_regions = 0;
 320         }
 321
 322 #ifdef __LITTLE_ENDIAN
 323         if (log->header.version == 1)
 324                 log->header.version = 2;
 325 #endif
 326
 327         if (log->header.version != MIRROR_DISK_VERSION) {
 328                 DMWARN("incompatible disk log version");
 329                 return -EINVAL;
 330         }
 331
 332         return 0;
 333 }
 334
 335 static int _check_region_size(struct dm_target *ti, uint32_t region_size)
 336 {
 337         if (region_size < 2 || region_size > ti->len)
 338                 return 0;
 339
 340         if (!is_power_of_2(region_size))
 341                 return 0;
 342
 343         return 1;
 344 }
 345
 346 /*----------------------------------------------------------------
 347  * core log constructor/destructor
 348  *
 349  * argv contains region_size followed optionally by [no]sync
 350  *--------------------------------------------------------------*/
 351 #define BYTE_SHIFT 3
 352 static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti,
 353                               unsigned int argc, char **argv,
 354                               struct dm_dev *dev)
 355 {
 356         enum sync sync = DEFAULTSYNC;
 357
 358         struct log_c *lc;
 359         uint32_t region_size;
 360         unsigned int region_count;
 361         size_t bitset_size, buf_size;
 362         int r;
 363
 364         if (argc < 1 || argc > 2) {
 365                 DMWARN("wrong number of arguments to dirty region log");
 366                 return -EINVAL;
 367         }
 368
 369         if (argc > 1) {
 370                 if (!strcmp(argv[1], "sync"))
 371                         sync = FORCESYNC;
 372                 else if (!strcmp(argv[1], "nosync"))
 373                         sync = NOSYNC;
 374                 else {
 375                         DMWARN("unrecognised sync argument to "
 376                                "dirty region log: %s", argv[1]);
 377                         return -EINVAL;
 378                 }
 379         }
 380
 381         if (sscanf(argv[0], "%u", &region_size) != 1 ||
 382             !_check_region_size(ti, region_size)) {
 383                 DMWARN("invalid region size %s", argv[0]);
 384                 return -EINVAL;
 385         }
 386
 387         region_count = dm_sector_div_up(ti->len, region_size);
 388
 389         lc = kmalloc(sizeof(*lc), GFP_KERNEL);
 390         if (!lc) {
 391                 DMWARN("couldn't allocate core log");
 392                 return -ENOMEM;
 393         }
 394
 395         lc->ti = ti;
 396         lc->touched_dirtied = 0;
 397         lc->touched_cleaned = 0;
 398         lc->flush_failed = 0;
 399         lc->region_size = region_size;
 400         lc->region_count = region_count;
 401         lc->sync = sync;
 402
 403         /*
 404          * Work out how many "unsigned long"s we need to hold the bitset.
 405          */
 406         bitset_size = dm_round_up(region_count,
 407                                   sizeof(*lc->clean_bits) << BYTE_SHIFT);
 408         bitset_size >>= BYTE_SHIFT;
 409
 410         lc->bitset_uint32_count = bitset_size / sizeof(*lc->clean_bits);
 411
 412         /*
 413          * Disk log?
 414          */
 415         if (!dev) {
 416                 lc->clean_bits = vmalloc(bitset_size);
 417                 if (!lc->clean_bits) {
 418                         DMWARN("couldn't allocate clean bitset");
 419                         kfree(lc);
 420                         return -ENOMEM;
 421                 }
 422                 lc->disk_header = NULL;
 423         } else {
 424                 lc->log_dev = dev;
 425                 lc->log_dev_failed = 0;
 426                 lc->header_location.bdev = lc->log_dev->bdev;
 427                 lc->header_location.sector = 0;
 428
 429                 /*
 430                  * Buffer holds both header and bitset.
 431                  */
 432                 buf_size =
 433                     dm_round_up((LOG_OFFSET << SECTOR_SHIFT) + bitset_size,
 434                                 bdev_logical_block_size(lc->header_location.
 435                                                             bdev));
 436
 437                 if (buf_size > i_size_read(dev->bdev->bd_inode)) {
 438                         DMWARN("log device %s too small: need %llu bytes",
 439                                 dev->name, (unsigned long long)buf_size);
 440                         kfree(lc);
 441                         return -EINVAL;
 442                 }
 443
 444                 lc->header_location.count = buf_size >> SECTOR_SHIFT;
 445
 446                 lc->io_req.mem.type = DM_IO_VMA;
 447                 lc->io_req.notify.fn = NULL;
 448                 lc->io_req.client = dm_io_client_create(dm_div_up(buf_size,
 449                                                                    PAGE_SIZE));
 450                 if (IS_ERR(lc->io_req.client)) {
 451                         r = PTR_ERR(lc->io_req.client);
 452                         DMWARN("couldn't allocate disk io client");
 453                         kfree(lc);
 454                         return -ENOMEM;
 455                 }
 456
 457                 lc->disk_header = vmalloc(buf_size);
 458                 if (!lc->disk_header) {
 459                         DMWARN("couldn't allocate disk log buffer");
 460                         dm_io_client_destroy(lc->io_req.client);
 461                         kfree(lc);
 462                         return -ENOMEM;
 463                 }
 464
 465                 lc->io_req.mem.ptr.vma = lc->disk_header;
 466                 lc->clean_bits = (void *)lc->disk_header +
 467                                  (LOG_OFFSET << SECTOR_SHIFT);
 468         }
 469
 470         memset(lc->clean_bits, -1, bitset_size);
 471
 472         lc->sync_bits = vmalloc(bitset_size);
 473         if (!lc->sync_bits) {
 474                 DMWARN("couldn't allocate sync bitset");
 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->sync_bits, (sync == NOSYNC) ? -1 : 0, bitset_size);
 484         lc->sync_count = (sync == NOSYNC) ? region_count : 0;
 485
 486         lc->recovering_bits = vmalloc(bitset_size);
 487         if (!lc->recovering_bits) {
 488                 DMWARN("couldn't allocate sync bitset");
 489                 vfree(lc->sync_bits);
 490                 if (!dev)
 491                         vfree(lc->clean_bits);
 492                 else
 493                         dm_io_client_destroy(lc->io_req.client);
 494                 vfree(lc->disk_header);
 495                 kfree(lc);
 496                 return -ENOMEM;
 497         }
 498         memset(lc->recovering_bits, 0, bitset_size);
 499         lc->sync_search = 0;
 500         log->context = lc;
 501
 502         return 0;
 503 }
 504
 505 static int core_ctr(struct dm_dirty_log *log, struct dm_target *ti,
 506                     unsigned int argc, char **argv)
 507 {
 508         return create_log_context(log, ti, argc, argv, NULL);
 509 }
 510
 511 static void destroy_log_context(struct log_c *lc)
 512 {
 513         vfree(lc->sync_bits);
 514         vfree(lc->recovering_bits);
 515         kfree(lc);
 516 }
 517
 518 static void core_dtr(struct dm_dirty_log *log)
 519 {
 520         struct log_c *lc = (struct log_c *) log->context;
 521
 522         vfree(lc->clean_bits);
 523         destroy_log_context(lc);
 524 }
 525
 526 /*----------------------------------------------------------------
 527  * disk log constructor/destructor
 528  *
 529  * argv contains log_device region_size followed optionally by [no]sync
 530  *--------------------------------------------------------------*/
 531 static int disk_ctr(struct dm_dirty_log *log, struct dm_target *ti,
 532                     unsigned int argc, char **argv)
 533 {
 534         int r;
 535         struct dm_dev *dev;
 536
 537         if (argc < 2 || argc > 3) {
 538                 DMWARN("wrong number of arguments to disk dirty region log");
 539                 return -EINVAL;
 540         }
 541
 542         r = dm_get_device(ti, argv[0], 0, 0 /* FIXME */,
 543                           FMODE_READ | FMODE_WRITE, &dev);
 544         if (r)
 545                 return r;
 546
 547         r = create_log_context(log, ti, argc - 1, argv + 1, dev);
 548         if (r) {
 549                 dm_put_device(ti, dev);
 550                 return r;
 551         }
 552
 553         return 0;
 554 }
 555
 556 static void disk_dtr(struct dm_dirty_log *log)
 557 {
 558         struct log_c *lc = (struct log_c *) log->context;
 559
 560         dm_put_device(lc->ti, lc->log_dev);
 561         vfree(lc->disk_header);
 562         dm_io_client_destroy(lc->io_req.client);
 563         destroy_log_context(lc);
 564 }
 565
 566 static int count_bits32(uint32_t *addr, unsigned size)
 567 {
 568         int count = 0, i;
 569
 570         for (i = 0; i < size; i++) {
 571                 count += hweight32(*(addr+i));
 572         }
 573         return count;
 574 }
 575
 576 static void fail_log_device(struct log_c *lc)
 577 {
 578         if (lc->log_dev_failed)
 579                 return;
 580
 581         lc->log_dev_failed = 1;
 582         dm_table_event(lc->ti->table);
 583 }
 584
 585 static int disk_resume(struct dm_dirty_log *log)
 586 {
 587         int r;
 588         unsigned i;
 589         struct log_c *lc = (struct log_c *) log->context;
 590         size_t size = lc->bitset_uint32_count * sizeof(uint32_t);
 591
 592         /* read the disk header */
 593         r = read_header(lc);
 594         if (r) {
 595                 DMWARN("%s: Failed to read header on dirty region log device",
 596                        lc->log_dev->name);
 597                 fail_log_device(lc);
 598                 /*
 599                  * If the log device cannot be read, we must assume
 600                  * all regions are out-of-sync.  If we simply return
 601                  * here, the state will be uninitialized and could
 602                  * lead us to return 'in-sync' status for regions
 603                  * that are actually 'out-of-sync'.
 604                  */
 605                 lc->header.nr_regions = 0;
 606         }
 607
 608         /* set or clear any new bits -- device has grown */
 609         if (lc->sync == NOSYNC)
 610                 for (i = lc->header.nr_regions; i < lc->region_count; i++)
 611                         /* FIXME: amazingly inefficient */
 612                         log_set_bit(lc, lc->clean_bits, i);
 613         else
 614                 for (i = lc->header.nr_regions; i < lc->region_count; i++)
 615                         /* FIXME: amazingly inefficient */
 616                         log_clear_bit(lc, lc->clean_bits, i);
 617
 618         /* clear any old bits -- device has shrunk */
 619         for (i = lc->region_count; i % (sizeof(*lc->clean_bits) << BYTE_SHIFT); i++)
 620                 log_clear_bit(lc, lc->clean_bits, i);
 621
 622         /* copy clean across to sync */
 623         memcpy(lc->sync_bits, lc->clean_bits, size);
 624         lc->sync_count = count_bits32(lc->clean_bits, lc->bitset_uint32_count);
 625         lc->sync_search = 0;
 626
 627         /* set the correct number of regions in the header */
 628         lc->header.nr_regions = lc->region_count;
 629
 630         header_to_disk(&lc->header, lc->disk_header);
 631
 632         /* write the new header */
 633         r = rw_header(lc, WRITE);
 634         if (!r)
 635                 r = flush_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_cleaned && !lc->touched_dirtied)
 683                 return 0;
 684
 685         r = rw_header(lc, WRITE);
 686         if (r)
 687                 fail_log_device(lc);
 688         else {
 689                 if (lc->touched_dirtied) {
 690                         r = flush_header(lc);
 691                         if (r)
 692                                 fail_log_device(lc);
 693                         else
 694                                 lc->touched_dirtied = 0;
 695                 }
 696                 lc->touched_cleaned = 0;
 697         }
 698
 699         return r;
 700 }
 701
 702 static void core_mark_region(struct dm_dirty_log *log, region_t region)
 703 {
 704         struct log_c *lc = (struct log_c *) log->context;
 705         log_clear_bit(lc, lc->clean_bits, region);
 706 }
 707
 708 static void core_clear_region(struct dm_dirty_log *log, region_t region)
 709 {
 710         struct log_c *lc = (struct log_c *) log->context;
 711         if (likely(!lc->flush_failed))
 712                 log_set_bit(lc, lc->clean_bits, region);
 713 }
 714
 715 static int core_get_resync_work(struct dm_dirty_log *log, region_t *region)
 716 {
 717         struct log_c *lc = (struct log_c *) log->context;
 718
 719         if (lc->sync_search >= lc->region_count)
 720                 return 0;
 721
 722         do {
 723                 *region = ext2_find_next_zero_bit(
 724                                              (unsigned long *) lc->sync_bits,
 725                                              lc->region_count,
 726                                              lc->sync_search);
 727                 lc->sync_search = *region + 1;
 728
 729                 if (*region >= lc->region_count)
 730                         return 0;
 731
 732         } while (log_test_bit(lc->recovering_bits, *region));
 733
 734         log_set_bit(lc, lc->recovering_bits, *region);
 735         return 1;
 736 }
 737
 738 static void core_set_region_sync(struct dm_dirty_log *log, region_t region,
 739                                  int in_sync)
 740 {
 741         struct log_c *lc = (struct log_c *) log->context;
 742
 743         log_clear_bit(lc, lc->recovering_bits, region);
 744         if (in_sync) {
 745                 log_set_bit(lc, lc->sync_bits, region);
 746                 lc->sync_count++;
 747         } else if (log_test_bit(lc->sync_bits, region)) {
 748                 lc->sync_count--;
 749                 log_clear_bit(lc, lc->sync_bits, region);
 750         }
 751 }
 752
 753 static region_t core_get_sync_count(struct dm_dirty_log *log)
 754 {
 755         struct log_c *lc = (struct log_c *) log->context;
 756
 757         return lc->sync_count;
 758 }
 759
 760 #define DMEMIT_SYNC \
 761         if (lc->sync != DEFAULTSYNC) \
 762                 DMEMIT("%ssync ", lc->sync == NOSYNC ? "no" : "")
 763
 764 static int core_status(struct dm_dirty_log *log, status_type_t status,
 765                        char *result, unsigned int maxlen)
 766 {
 767         int sz = 0;
 768         struct log_c *lc = log->context;
 769
 770         switch(status) {
 771         case STATUSTYPE_INFO:
 772                 DMEMIT("1 %s", log->type->name);
 773                 break;
 774
 775         case STATUSTYPE_TABLE:
 776                 DMEMIT("%s %u %u ", log->type->name,
 777                        lc->sync == DEFAULTSYNC ? 1 : 2, lc->region_size);
 778                 DMEMIT_SYNC;
 779         }
 780
 781         return sz;
 782 }
 783
 784 static int disk_status(struct dm_dirty_log *log, status_type_t status,
 785                        char *result, unsigned int maxlen)
 786 {
 787         int sz = 0;
 788         struct log_c *lc = log->context;
 789
 790         switch(status) {
 791         case STATUSTYPE_INFO:
 792                 DMEMIT("3 %s %s %c", log->type->name, lc->log_dev->name,
 793                        lc->log_dev_failed ? 'D' : 'A');
 794                 break;
 795
 796         case STATUSTYPE_TABLE:
 797                 DMEMIT("%s %u %s %u ", log->type->name,
 798                        lc->sync == DEFAULTSYNC ? 2 : 3, lc->log_dev->name,
 799                        lc->region_size);
 800                 DMEMIT_SYNC;
 801         }
 802
 803         return sz;
 804 }
 805
 806 static struct dm_dirty_log_type _core_type = {
 807         .name = "core",
 808         .module = THIS_MODULE,
 809         .ctr = core_ctr,
 810         .dtr = core_dtr,
 811         .resume = core_resume,
 812         .get_region_size = core_get_region_size,
 813         .is_clean = core_is_clean,
 814         .in_sync = core_in_sync,
 815         .flush = core_flush,
 816         .mark_region = core_mark_region,
 817         .clear_region = core_clear_region,
 818         .get_resync_work = core_get_resync_work,
 819         .set_region_sync = core_set_region_sync,
 820         .get_sync_count = core_get_sync_count,
 821         .status = core_status,
 822 };
 823
 824 static struct dm_dirty_log_type _disk_type = {
 825         .name = "disk",
 826         .module = THIS_MODULE,
 827         .ctr = disk_ctr,
 828         .dtr = disk_dtr,
 829         .postsuspend = disk_flush,
 830         .resume = disk_resume,
 831         .get_region_size = core_get_region_size,
 832         .is_clean = core_is_clean,
 833         .in_sync = core_in_sync,
 834         .flush = disk_flush,
 835         .mark_region = core_mark_region,
 836         .clear_region = core_clear_region,
 837         .get_resync_work = core_get_resync_work,
 838         .set_region_sync = core_set_region_sync,
 839         .get_sync_count = core_get_sync_count,
 840         .status = disk_status,
 841 };
 842
 843 static int __init dm_dirty_log_init(void)
 844 {
 845         int r;
 846
 847         r = dm_dirty_log_type_register(&_core_type);
 848         if (r)
 849                 DMWARN("couldn't register core log");
 850
 851         r = dm_dirty_log_type_register(&_disk_type);
 852         if (r) {
 853                 DMWARN("couldn't register disk type");
 854                 dm_dirty_log_type_unregister(&_core_type);
 855         }
 856
 857         return r;
 858 }
 859
 860 static void __exit dm_dirty_log_exit(void)
 861 {
 862         dm_dirty_log_type_unregister(&_disk_type);
 863         dm_dirty_log_type_unregister(&_core_type);
 864 }
 865
 866 module_init(dm_dirty_log_init);
 867 module_exit(dm_dirty_log_exit);
 868
 869 MODULE_DESCRIPTION(DM_NAME " dirty region log");
 870 MODULE_AUTHOR("Joe Thornber, Heinz Mauelshagen <dm-devel@redhat.com>");
 871 MODULE_LICENSE("GPL");