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 struct dm_dirty_log_internal {
  20         struct dm_dirty_log_type *type;
  21
  22         struct list_head list;
  23         long use;
  24 };
  25
  26 static LIST_HEAD(_log_types);
  27 static DEFINE_SPINLOCK(_lock);
  28
  29 static struct dm_dirty_log_internal *__find_dirty_log_type(const char *name)
  30 {
  31         struct dm_dirty_log_internal *log_type;
  32
  33         list_for_each_entry(log_type, &_log_types, list)
  34                 if (!strcmp(name, log_type->type->name))
  35                         return log_type;
  36
  37         return NULL;
  38 }
  39
  40 static struct dm_dirty_log_internal *_get_dirty_log_type(const char *name)
  41 {
  42         struct dm_dirty_log_internal *log_type;
  43
  44         spin_lock(&_lock);
  45
  46         log_type = __find_dirty_log_type(name);
  47         if (log_type) {
  48                 if (!log_type->use && !try_module_get(log_type->type->module))
  49                         log_type = NULL;
  50                 else
  51                         log_type->use++;
  52         }
  53
  54         spin_unlock(&_lock);
  55
  56         return log_type;
  57 }
  58
  59 /*
  60  * get_type
  61  * @type_name
  62  *
  63  * Attempt to retrieve the dm_dirty_log_type by name.  If not already
  64  * available, attempt to load the appropriate module.
  65  *
  66  * Log modules are named "dm-log-" followed by the 'type_name'.
  67  * Modules may contain multiple types.
  68  * This function will first try the module "dm-log-<type_name>",
  69  * then truncate 'type_name' on the last '-' and try again.
  70  *
  71  * For example, if type_name was "clustered-disk", it would search
  72  * 'dm-log-clustered-disk' then 'dm-log-clustered'.
  73  *
  74  * Returns: dirty_log_type* on success, NULL on failure
  75  */
  76 static struct dm_dirty_log_type *get_type(const char *type_name)
  77 {
  78         char *p, *type_name_dup;
  79         struct dm_dirty_log_internal *log_type;
  80
  81         if (!type_name)
  82                 return NULL;
  83
  84         log_type = _get_dirty_log_type(type_name);
  85         if (log_type)
  86                 return log_type->type;
  87
  88         type_name_dup = kstrdup(type_name, GFP_KERNEL);
  89         if (!type_name_dup) {
  90                 DMWARN("No memory left to attempt log module load for \"%s\"",
  91                        type_name);
  92                 return NULL;
  93         }
  94
  95         while (request_module("dm-log-%s", type_name_dup) ||
  96                !(log_type = _get_dirty_log_type(type_name))) {
  97                 p = strrchr(type_name_dup, '-');
  98                 if (!p)
  99                         break;
 100                 p[0] = '\0';
 101         }
 102
 103         if (!log_type)
 104                 DMWARN("Module for logging type \"%s\" not found.", type_name);
 105
 106         kfree(type_name_dup);
 107
 108         return log_type ? log_type->type : NULL;
 109 }
 110
 111 static void put_type(struct dm_dirty_log_type *type)
 112 {
 113         struct dm_dirty_log_internal *log_type;
 114
 115         if (!type)
 116                 return;
 117
 118         spin_lock(&_lock);
 119         log_type = __find_dirty_log_type(type->name);
 120         if (!log_type)
 121                 goto out;
 122
 123         if (!--log_type->use)
 124                 module_put(type->module);
 125
 126         BUG_ON(log_type->use < 0);
 127
 128 out:
 129         spin_unlock(&_lock);
 130 }
 131
 132 static struct dm_dirty_log_internal *_alloc_dirty_log_type(struct dm_dirty_log_type *type)
 133 {
 134         struct dm_dirty_log_internal *log_type = kzalloc(sizeof(*log_type),
 135                                                          GFP_KERNEL);
 136
 137         if (log_type)
 138                 log_type->type = type;
 139
 140         return log_type;
 141 }
 142
 143 int dm_dirty_log_type_register(struct dm_dirty_log_type *type)
 144 {
 145         struct dm_dirty_log_internal *log_type = _alloc_dirty_log_type(type);
 146         int r = 0;
 147
 148         if (!log_type)
 149                 return -ENOMEM;
 150
 151         spin_lock(&_lock);
 152         if (!__find_dirty_log_type(type->name))
 153                 list_add(&log_type->list, &_log_types);
 154         else {
 155                 kfree(log_type);
 156                 r = -EEXIST;
 157         }
 158         spin_unlock(&_lock);
 159
 160         return r;
 161 }
 162 EXPORT_SYMBOL(dm_dirty_log_type_register);
 163
 164 int dm_dirty_log_type_unregister(struct dm_dirty_log_type *type)
 165 {
 166         struct dm_dirty_log_internal *log_type;
 167
 168         spin_lock(&_lock);
 169
 170         log_type = __find_dirty_log_type(type->name);
 171         if (!log_type) {
 172                 spin_unlock(&_lock);
 173                 return -EINVAL;
 174         }
 175
 176         if (log_type->use) {
 177                 spin_unlock(&_lock);
 178                 return -ETXTBSY;
 179         }
 180
 181         list_del(&log_type->list);
 182
 183         spin_unlock(&_lock);
 184         kfree(log_type);
 185
 186         return 0;
 187 }
 188 EXPORT_SYMBOL(dm_dirty_log_type_unregister);
 189
 190 struct dm_dirty_log *dm_dirty_log_create(const char *type_name,
 191                                          struct dm_target *ti,
 192                                          unsigned int argc, char **argv)
 193 {
 194         struct dm_dirty_log_type *type;
 195         struct dm_dirty_log *log;
 196
 197         log = kmalloc(sizeof(*log), GFP_KERNEL);
 198         if (!log)
 199                 return NULL;
 200
 201         type = get_type(type_name);
 202         if (!type) {
 203                 kfree(log);
 204                 return NULL;
 205         }
 206
 207         log->type = type;
 208         if (type->ctr(log, ti, argc, argv)) {
 209                 kfree(log);
 210                 put_type(type);
 211                 return NULL;
 212         }
 213
 214         return log;
 215 }
 216 EXPORT_SYMBOL(dm_dirty_log_create);
 217
 218 void dm_dirty_log_destroy(struct dm_dirty_log *log)
 219 {
 220         log->type->dtr(log);
 221         put_type(log->type);
 222         kfree(log);
 223 }
 224 EXPORT_SYMBOL(dm_dirty_log_destroy);
 225
 226 /*-----------------------------------------------------------------
 227  * Persistent and core logs share a lot of their implementation.
 228  * FIXME: need a reload method to be called from a resume
 229  *---------------------------------------------------------------*/
 230 /*
 231  * Magic for persistent mirrors: "MiRr"
 232  */
 233 #define MIRROR_MAGIC 0x4D695272
 234
 235 /*
 236  * The on-disk version of the metadata.
 237  */
 238 #define MIRROR_DISK_VERSION 2
 239 #define LOG_OFFSET 2
 240
 241 struct log_header {
 242         uint32_t magic;
 243
 244         /*
 245          * Simple, incrementing version. no backward
 246          * compatibility.
 247          */
 248         uint32_t version;
 249         sector_t nr_regions;
 250 };
 251
 252 struct log_c {
 253         struct dm_target *ti;
 254         int touched;
 255         uint32_t region_size;
 256         unsigned int region_count;
 257         region_t sync_count;
 258
 259         unsigned bitset_uint32_count;
 260         uint32_t *clean_bits;
 261         uint32_t *sync_bits;
 262         uint32_t *recovering_bits;      /* FIXME: this seems excessive */
 263
 264         int sync_search;
 265
 266         /* Resync flag */
 267         enum sync {
 268                 DEFAULTSYNC,    /* Synchronize if necessary */
 269                 NOSYNC,         /* Devices known to be already in sync */
 270                 FORCESYNC,      /* Force a sync to happen */
 271         } sync;
 272
 273         struct dm_io_request io_req;
 274
 275         /*
 276          * Disk log fields
 277          */
 278         int log_dev_failed;
 279         struct dm_dev *log_dev;
 280         struct log_header header;
 281
 282         struct dm_io_region header_location;
 283         struct log_header *disk_header;
 284 };
 285
 286 /*
 287  * The touched member needs to be updated every time we access
 288  * one of the bitsets.
 289  */
 290 static inline int log_test_bit(uint32_t *bs, unsigned bit)
 291 {
 292         return ext2_test_bit(bit, (unsigned long *) bs) ? 1 : 0;
 293 }
 294
 295 static inline void log_set_bit(struct log_c *l,
 296                                uint32_t *bs, unsigned bit)
 297 {
 298         ext2_set_bit(bit, (unsigned long *) bs);
 299         l->touched = 1;
 300 }
 301
 302 static inline void log_clear_bit(struct log_c *l,
 303                                  uint32_t *bs, unsigned bit)
 304 {
 305         ext2_clear_bit(bit, (unsigned long *) bs);
 306         l->touched = 1;
 307 }
 308
 309 /*----------------------------------------------------------------
 310  * Header IO
 311  *--------------------------------------------------------------*/
 312 static void header_to_disk(struct log_header *core, struct log_header *disk)
 313 {
 314         disk->magic = cpu_to_le32(core->magic);
 315         disk->version = cpu_to_le32(core->version);
 316         disk->nr_regions = cpu_to_le64(core->nr_regions);
 317 }
 318
 319 static void header_from_disk(struct log_header *core, struct log_header *disk)
 320 {
 321         core->magic = le32_to_cpu(disk->magic);
 322         core->version = le32_to_cpu(disk->version);
 323         core->nr_regions = le64_to_cpu(disk->nr_regions);
 324 }
 325
 326 static int rw_header(struct log_c *lc, int rw)
 327 {
 328         lc->io_req.bi_rw = rw;
 329
 330         return dm_io(&lc->io_req, 1, &lc->header_location, NULL);
 331 }
 332
 333 static int read_header(struct log_c *log)
 334 {
 335         int r;
 336
 337         r = rw_header(log, READ);
 338         if (r)
 339                 return r;
 340
 341         header_from_disk(&log->header, log->disk_header);
 342
 343         /* New log required? */
 344         if (log->sync != DEFAULTSYNC || log->header.magic != MIRROR_MAGIC) {
 345                 log->header.magic = MIRROR_MAGIC;
 346                 log->header.version = MIRROR_DISK_VERSION;
 347                 log->header.nr_regions = 0;
 348         }
 349
 350 #ifdef __LITTLE_ENDIAN
 351         if (log->header.version == 1)
 352                 log->header.version = 2;
 353 #endif
 354
 355         if (log->header.version != MIRROR_DISK_VERSION) {
 356                 DMWARN("incompatible disk log version");
 357                 return -EINVAL;
 358         }
 359
 360         return 0;
 361 }
 362
 363 static int _check_region_size(struct dm_target *ti, uint32_t region_size)
 364 {
 365         if (region_size < 2 || region_size > ti->len)
 366                 return 0;
 367
 368         if (!is_power_of_2(region_size))
 369                 return 0;
 370
 371         return 1;
 372 }
 373
 374 /*----------------------------------------------------------------
 375  * core log constructor/destructor
 376  *
 377  * argv contains region_size followed optionally by [no]sync
 378  *--------------------------------------------------------------*/
 379 #define BYTE_SHIFT 3
 380 static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti,
 381                               unsigned int argc, char **argv,
 382                               struct dm_dev *dev)
 383 {
 384         enum sync sync = DEFAULTSYNC;
 385
 386         struct log_c *lc;
 387         uint32_t region_size;
 388         unsigned int region_count;
 389         size_t bitset_size, buf_size;
 390         int r;
 391
 392         if (argc < 1 || argc > 2) {
 393                 DMWARN("wrong number of arguments to dirty region log");
 394                 return -EINVAL;
 395         }
 396
 397         if (argc > 1) {
 398                 if (!strcmp(argv[1], "sync"))
 399                         sync = FORCESYNC;
 400                 else if (!strcmp(argv[1], "nosync"))
 401                         sync = NOSYNC;
 402                 else {
 403                         DMWARN("unrecognised sync argument to "
 404                                "dirty region log: %s", argv[1]);
 405                         return -EINVAL;
 406                 }
 407         }
 408
 409         if (sscanf(argv[0], "%u", &region_size) != 1 ||
 410             !_check_region_size(ti, region_size)) {
 411                 DMWARN("invalid region size %s", argv[0]);
 412                 return -EINVAL;
 413         }
 414
 415         region_count = dm_sector_div_up(ti->len, region_size);
 416
 417         lc = kmalloc(sizeof(*lc), GFP_KERNEL);
 418         if (!lc) {
 419                 DMWARN("couldn't allocate core log");
 420                 return -ENOMEM;
 421         }
 422
 423         lc->ti = ti;
 424         lc->touched = 0;
 425         lc->region_size = region_size;
 426         lc->region_count = region_count;
 427         lc->sync = sync;
 428
 429         /*
 430          * Work out how many "unsigned long"s we need to hold the bitset.
 431          */
 432         bitset_size = dm_round_up(region_count,
 433                                   sizeof(*lc->clean_bits) << BYTE_SHIFT);
 434         bitset_size >>= BYTE_SHIFT;
 435
 436         lc->bitset_uint32_count = bitset_size / sizeof(*lc->clean_bits);
 437
 438         /*
 439          * Disk log?
 440          */
 441         if (!dev) {
 442                 lc->clean_bits = vmalloc(bitset_size);
 443                 if (!lc->clean_bits) {
 444                         DMWARN("couldn't allocate clean bitset");
 445                         kfree(lc);
 446                         return -ENOMEM;
 447                 }
 448                 lc->disk_header = NULL;
 449         } else {
 450                 lc->log_dev = dev;
 451                 lc->log_dev_failed = 0;
 452                 lc->header_location.bdev = lc->log_dev->bdev;
 453                 lc->header_location.sector = 0;
 454
 455                 /*
 456                  * Buffer holds both header and bitset.
 457                  */
 458                 buf_size = dm_round_up((LOG_OFFSET << SECTOR_SHIFT) +
 459                                        bitset_size, ti->limits.hardsect_size);
 460
 461                 if (buf_size > dev->bdev->bd_inode->i_size) {
 462                         DMWARN("log device %s too small: need %llu bytes",
 463                                 dev->name, (unsigned long long)buf_size);
 464                         kfree(lc);
 465                         return -EINVAL;
 466                 }
 467
 468                 lc->header_location.count = buf_size >> SECTOR_SHIFT;
 469
 470                 lc->io_req.mem.type = DM_IO_VMA;
 471                 lc->io_req.notify.fn = NULL;
 472                 lc->io_req.client = dm_io_client_create(dm_div_up(buf_size,
 473                                                                    PAGE_SIZE));
 474                 if (IS_ERR(lc->io_req.client)) {
 475                         r = PTR_ERR(lc->io_req.client);
 476                         DMWARN("couldn't allocate disk io client");
 477                         kfree(lc);
 478                         return -ENOMEM;
 479                 }
 480
 481                 lc->disk_header = vmalloc(buf_size);
 482                 if (!lc->disk_header) {
 483                         DMWARN("couldn't allocate disk log buffer");
 484                         dm_io_client_destroy(lc->io_req.client);
 485                         kfree(lc);
 486                         return -ENOMEM;
 487                 }
 488
 489                 lc->io_req.mem.ptr.vma = lc->disk_header;
 490                 lc->clean_bits = (void *)lc->disk_header +
 491                                  (LOG_OFFSET << SECTOR_SHIFT);
 492         }
 493
 494         memset(lc->clean_bits, -1, bitset_size);
 495
 496         lc->sync_bits = vmalloc(bitset_size);
 497         if (!lc->sync_bits) {
 498                 DMWARN("couldn't allocate sync bitset");
 499                 if (!dev)
 500                         vfree(lc->clean_bits);
 501                 else
 502                         dm_io_client_destroy(lc->io_req.client);
 503                 vfree(lc->disk_header);
 504                 kfree(lc);
 505                 return -ENOMEM;
 506         }
 507         memset(lc->sync_bits, (sync == NOSYNC) ? -1 : 0, bitset_size);
 508         lc->sync_count = (sync == NOSYNC) ? region_count : 0;
 509
 510         lc->recovering_bits = vmalloc(bitset_size);
 511         if (!lc->recovering_bits) {
 512                 DMWARN("couldn't allocate sync bitset");
 513                 vfree(lc->sync_bits);
 514                 if (!dev)
 515                         vfree(lc->clean_bits);
 516                 else
 517                         dm_io_client_destroy(lc->io_req.client);
 518                 vfree(lc->disk_header);
 519                 kfree(lc);
 520                 return -ENOMEM;
 521         }
 522         memset(lc->recovering_bits, 0, bitset_size);
 523         lc->sync_search = 0;
 524         log->context = lc;
 525
 526         return 0;
 527 }
 528
 529 static int core_ctr(struct dm_dirty_log *log, struct dm_target *ti,
 530                     unsigned int argc, char **argv)
 531 {
 532         return create_log_context(log, ti, argc, argv, NULL);
 533 }
 534
 535 static void destroy_log_context(struct log_c *lc)
 536 {
 537         vfree(lc->sync_bits);
 538         vfree(lc->recovering_bits);
 539         kfree(lc);
 540 }
 541
 542 static void core_dtr(struct dm_dirty_log *log)
 543 {
 544         struct log_c *lc = (struct log_c *) log->context;
 545
 546         vfree(lc->clean_bits);
 547         destroy_log_context(lc);
 548 }
 549
 550 /*----------------------------------------------------------------
 551  * disk log constructor/destructor
 552  *
 553  * argv contains log_device region_size followed optionally by [no]sync
 554  *--------------------------------------------------------------*/
 555 static int disk_ctr(struct dm_dirty_log *log, struct dm_target *ti,
 556                     unsigned int argc, char **argv)
 557 {
 558         int r;
 559         struct dm_dev *dev;
 560
 561         if (argc < 2 || argc > 3) {
 562                 DMWARN("wrong number of arguments to disk dirty region log");
 563                 return -EINVAL;
 564         }
 565
 566         r = dm_get_device(ti, argv[0], 0, 0 /* FIXME */,
 567                           FMODE_READ | FMODE_WRITE, &dev);
 568         if (r)
 569                 return r;
 570
 571         r = create_log_context(log, ti, argc - 1, argv + 1, dev);
 572         if (r) {
 573                 dm_put_device(ti, dev);
 574                 return r;
 575         }
 576
 577         return 0;
 578 }
 579
 580 static void disk_dtr(struct dm_dirty_log *log)
 581 {
 582         struct log_c *lc = (struct log_c *) log->context;
 583
 584         dm_put_device(lc->ti, lc->log_dev);
 585         vfree(lc->disk_header);
 586         dm_io_client_destroy(lc->io_req.client);
 587         destroy_log_context(lc);
 588 }
 589
 590 static int count_bits32(uint32_t *addr, unsigned size)
 591 {
 592         int count = 0, i;
 593
 594         for (i = 0; i < size; i++) {
 595                 count += hweight32(*(addr+i));
 596         }
 597         return count;
 598 }
 599
 600 static void fail_log_device(struct log_c *lc)
 601 {
 602         if (lc->log_dev_failed)
 603                 return;
 604
 605         lc->log_dev_failed = 1;
 606         dm_table_event(lc->ti->table);
 607 }
 608
 609 static int disk_resume(struct dm_dirty_log *log)
 610 {
 611         int r;
 612         unsigned i;
 613         struct log_c *lc = (struct log_c *) log->context;
 614         size_t size = lc->bitset_uint32_count * sizeof(uint32_t);
 615
 616         /* read the disk header */
 617         r = read_header(lc);
 618         if (r) {
 619                 DMWARN("%s: Failed to read header on dirty region log device",
 620                        lc->log_dev->name);
 621                 fail_log_device(lc);
 622                 /*
 623                  * If the log device cannot be read, we must assume
 624                  * all regions are out-of-sync.  If we simply return
 625                  * here, the state will be uninitialized and could
 626                  * lead us to return 'in-sync' status for regions
 627                  * that are actually 'out-of-sync'.
 628                  */
 629                 lc->header.nr_regions = 0;
 630         }
 631
 632         /* set or clear any new bits -- device has grown */
 633         if (lc->sync == NOSYNC)
 634                 for (i = lc->header.nr_regions; i < lc->region_count; i++)
 635                         /* FIXME: amazingly inefficient */
 636                         log_set_bit(lc, lc->clean_bits, i);
 637         else
 638                 for (i = lc->header.nr_regions; i < lc->region_count; i++)
 639                         /* FIXME: amazingly inefficient */
 640                         log_clear_bit(lc, lc->clean_bits, i);
 641
 642         /* clear any old bits -- device has shrunk */
 643         for (i = lc->region_count; i % (sizeof(*lc->clean_bits) << BYTE_SHIFT); i++)
 644                 log_clear_bit(lc, lc->clean_bits, i);
 645
 646         /* copy clean across to sync */
 647         memcpy(lc->sync_bits, lc->clean_bits, size);
 648         lc->sync_count = count_bits32(lc->clean_bits, lc->bitset_uint32_count);
 649         lc->sync_search = 0;
 650
 651         /* set the correct number of regions in the header */
 652         lc->header.nr_regions = lc->region_count;
 653
 654         header_to_disk(&lc->header, lc->disk_header);
 655
 656         /* write the new header */
 657         r = rw_header(lc, WRITE);
 658         if (r) {
 659                 DMWARN("%s: Failed to write header on dirty region log device",
 660                        lc->log_dev->name);
 661                 fail_log_device(lc);
 662         }
 663
 664         return r;
 665 }
 666
 667 static uint32_t core_get_region_size(struct dm_dirty_log *log)
 668 {
 669         struct log_c *lc = (struct log_c *) log->context;
 670         return lc->region_size;
 671 }
 672
 673 static int core_resume(struct dm_dirty_log *log)
 674 {
 675         struct log_c *lc = (struct log_c *) log->context;
 676         lc->sync_search = 0;
 677         return 0;
 678 }
 679
 680 static int core_is_clean(struct dm_dirty_log *log, region_t region)
 681 {
 682         struct log_c *lc = (struct log_c *) log->context;
 683         return log_test_bit(lc->clean_bits, region);
 684 }
 685
 686 static int core_in_sync(struct dm_dirty_log *log, region_t region, int block)
 687 {
 688         struct log_c *lc = (struct log_c *) log->context;
 689         return log_test_bit(lc->sync_bits, region);
 690 }
 691
 692 static int core_flush(struct dm_dirty_log *log)
 693 {
 694         /* no op */
 695         return 0;
 696 }
 697
 698 static int disk_flush(struct dm_dirty_log *log)
 699 {
 700         int r;
 701         struct log_c *lc = (struct log_c *) log->context;
 702
 703         /* only write if the log has changed */
 704         if (!lc->touched)
 705                 return 0;
 706
 707         r = rw_header(lc, WRITE);
 708         if (r)
 709                 fail_log_device(lc);
 710         else
 711                 lc->touched = 0;
 712
 713         return r;
 714 }
 715
 716 static void core_mark_region(struct dm_dirty_log *log, region_t region)
 717 {
 718         struct log_c *lc = (struct log_c *) log->context;
 719         log_clear_bit(lc, lc->clean_bits, region);
 720 }
 721
 722 static void core_clear_region(struct dm_dirty_log *log, region_t region)
 723 {
 724         struct log_c *lc = (struct log_c *) log->context;
 725         log_set_bit(lc, lc->clean_bits, region);
 726 }
 727
 728 static int core_get_resync_work(struct dm_dirty_log *log, region_t *region)
 729 {
 730         struct log_c *lc = (struct log_c *) log->context;
 731
 732         if (lc->sync_search >= lc->region_count)
 733                 return 0;
 734
 735         do {
 736                 *region = ext2_find_next_zero_bit(
 737                                              (unsigned long *) lc->sync_bits,
 738                                              lc->region_count,
 739                                              lc->sync_search);
 740                 lc->sync_search = *region + 1;
 741
 742                 if (*region >= lc->region_count)
 743                         return 0;
 744
 745         } while (log_test_bit(lc->recovering_bits, *region));
 746
 747         log_set_bit(lc, lc->recovering_bits, *region);
 748         return 1;
 749 }
 750
 751 static void core_set_region_sync(struct dm_dirty_log *log, region_t region,
 752                                  int in_sync)
 753 {
 754         struct log_c *lc = (struct log_c *) log->context;
 755
 756         log_clear_bit(lc, lc->recovering_bits, region);
 757         if (in_sync) {
 758                 log_set_bit(lc, lc->sync_bits, region);
 759                 lc->sync_count++;
 760         } else if (log_test_bit(lc->sync_bits, region)) {
 761                 lc->sync_count--;
 762                 log_clear_bit(lc, lc->sync_bits, region);
 763         }
 764 }
 765
 766 static region_t core_get_sync_count(struct dm_dirty_log *log)
 767 {
 768         struct log_c *lc = (struct log_c *) log->context;
 769
 770         return lc->sync_count;
 771 }
 772
 773 #define DMEMIT_SYNC \
 774         if (lc->sync != DEFAULTSYNC) \
 775                 DMEMIT("%ssync ", lc->sync == NOSYNC ? "no" : "")
 776
 777 static int core_status(struct dm_dirty_log *log, status_type_t status,
 778                        char *result, unsigned int maxlen)
 779 {
 780         int sz = 0;
 781         struct log_c *lc = log->context;
 782
 783         switch(status) {
 784         case STATUSTYPE_INFO:
 785                 DMEMIT("1 %s", log->type->name);
 786                 break;
 787
 788         case STATUSTYPE_TABLE:
 789                 DMEMIT("%s %u %u ", log->type->name,
 790                        lc->sync == DEFAULTSYNC ? 1 : 2, lc->region_size);
 791                 DMEMIT_SYNC;
 792         }
 793
 794         return sz;
 795 }
 796
 797 static int disk_status(struct dm_dirty_log *log, status_type_t status,
 798                        char *result, unsigned int maxlen)
 799 {
 800         int sz = 0;
 801         struct log_c *lc = log->context;
 802
 803         switch(status) {
 804         case STATUSTYPE_INFO:
 805                 DMEMIT("3 %s %s %c", log->type->name, lc->log_dev->name,
 806                        lc->log_dev_failed ? 'D' : 'A');
 807                 break;
 808
 809         case STATUSTYPE_TABLE:
 810                 DMEMIT("%s %u %s %u ", log->type->name,
 811                        lc->sync == DEFAULTSYNC ? 2 : 3, lc->log_dev->name,
 812                        lc->region_size);
 813                 DMEMIT_SYNC;
 814         }
 815
 816         return sz;
 817 }
 818
 819 static struct dm_dirty_log_type _core_type = {
 820         .name = "core",
 821         .module = THIS_MODULE,
 822         .ctr = core_ctr,
 823         .dtr = core_dtr,
 824         .resume = core_resume,
 825         .get_region_size = core_get_region_size,
 826         .is_clean = core_is_clean,
 827         .in_sync = core_in_sync,
 828         .flush = core_flush,
 829         .mark_region = core_mark_region,
 830         .clear_region = core_clear_region,
 831         .get_resync_work = core_get_resync_work,
 832         .set_region_sync = core_set_region_sync,
 833         .get_sync_count = core_get_sync_count,
 834         .status = core_status,
 835 };
 836
 837 static struct dm_dirty_log_type _disk_type = {
 838         .name = "disk",
 839         .module = THIS_MODULE,
 840         .ctr = disk_ctr,
 841         .dtr = disk_dtr,
 842         .postsuspend = disk_flush,
 843         .resume = disk_resume,
 844         .get_region_size = core_get_region_size,
 845         .is_clean = core_is_clean,
 846         .in_sync = core_in_sync,
 847         .flush = disk_flush,
 848         .mark_region = core_mark_region,
 849         .clear_region = core_clear_region,
 850         .get_resync_work = core_get_resync_work,
 851         .set_region_sync = core_set_region_sync,
 852         .get_sync_count = core_get_sync_count,
 853         .status = disk_status,
 854 };
 855
 856 static int __init dm_dirty_log_init(void)
 857 {
 858         int r;
 859
 860         r = dm_dirty_log_type_register(&_core_type);
 861         if (r)
 862                 DMWARN("couldn't register core log");
 863
 864         r = dm_dirty_log_type_register(&_disk_type);
 865         if (r) {
 866                 DMWARN("couldn't register disk type");
 867                 dm_dirty_log_type_unregister(&_core_type);
 868         }
 869
 870         return r;
 871 }
 872
 873 static void __exit dm_dirty_log_exit(void)
 874 {
 875         dm_dirty_log_type_unregister(&_disk_type);
 876         dm_dirty_log_type_unregister(&_core_type);
 877 }
 878
 879 module_init(dm_dirty_log_init);
 880 module_exit(dm_dirty_log_exit);
 881
 882 MODULE_DESCRIPTION(DM_NAME " dirty region log");
 883 MODULE_AUTHOR("Joe Thornber, Heinz Mauelshagen <dm-devel@redhat.com>");
 884 MODULE_LICENSE("GPL");