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                         int (*flush_callback_fn)(struct dm_target *ti),
 150                         unsigned int argc, char **argv)
 151 {
 152         struct dm_dirty_log_type *type;
 153         struct dm_dirty_log *log;
 154
 155         log = kmalloc(sizeof(*log), GFP_KERNEL);
 156         if (!log)
 157                 return NULL;
 158
 159         type = get_type(type_name);
 160         if (!type) {
 161                 kfree(log);
 162                 return NULL;
 163         }
 164
 165         log->flush_callback_fn = flush_callback_fn;
 166         log->type = type;
 167         if (type->ctr(log, ti, argc, argv)) {
 168                 kfree(log);
 169                 put_type(type);
 170                 return NULL;
 171         }
 172
 173         return log;
 174 }
 175 EXPORT_SYMBOL(dm_dirty_log_create);
 176
 177 void dm_dirty_log_destroy(struct dm_dirty_log *log)
 178 {
 179         log->type->dtr(log);
 180         put_type(log->type);
 181         kfree(log);
 182 }
 183 EXPORT_SYMBOL(dm_dirty_log_destroy);
 184
 185 /*-----------------------------------------------------------------
 186  * Persistent and core logs share a lot of their implementation.
 187  * FIXME: need a reload method to be called from a resume
 188  *---------------------------------------------------------------*/
 189 /*
 190  * Magic for persistent mirrors: "MiRr"
 191  */
 192 #define MIRROR_MAGIC 0x4D695272
 193
 194 /*
 195  * The on-disk version of the metadata.
 196  */
 197 #define MIRROR_DISK_VERSION 2
 198 #define LOG_OFFSET 2
 199
 200 struct log_header_disk {
 201         __le32 magic;
 202
 203         /*
 204          * Simple, incrementing version. no backward
 205          * compatibility.
 206          */
 207         __le32 version;
 208         __le64 nr_regions;
 209 } __packed;
 210
 211 struct log_header_core {
 212         uint32_t magic;
 213         uint32_t version;
 214         uint64_t nr_regions;
 215 };
 216
 217 struct log_c {
 218         struct dm_target *ti;
 219         int touched_dirtied;
 220         int touched_cleaned;
 221         int flush_failed;
 222         uint32_t region_size;
 223         unsigned int region_count;
 224         region_t sync_count;
 225
 226         unsigned bitset_uint32_count;
 227         uint32_t *clean_bits;
 228         uint32_t *sync_bits;
 229         uint32_t *recovering_bits;      /* FIXME: this seems excessive */
 230
 231         int sync_search;
 232
 233         /* Resync flag */
 234         enum sync {
 235                 DEFAULTSYNC,    /* Synchronize if necessary */
 236                 NOSYNC,         /* Devices known to be already in sync */
 237                 FORCESYNC,      /* Force a sync to happen */
 238         } sync;
 239
 240         struct dm_io_request io_req;
 241
 242         /*
 243          * Disk log fields
 244          */
 245         int log_dev_failed;
 246         int log_dev_flush_failed;
 247         struct dm_dev *log_dev;
 248         struct log_header_core header;
 249
 250         struct dm_io_region header_location;
 251         struct log_header_disk *disk_header;
 252 };
 253
 254 /*
 255  * The touched member needs to be updated every time we access
 256  * one of the bitsets.
 257  */
 258 static inline int log_test_bit(uint32_t *bs, unsigned bit)
 259 {
 260         return test_bit_le(bit, bs) ? 1 : 0;
 261 }
 262
 263 static inline void log_set_bit(struct log_c *l,
 264                                uint32_t *bs, unsigned bit)
 265 {
 266         __set_bit_le(bit, bs);
 267         l->touched_cleaned = 1;
 268 }
 269
 270 static inline void log_clear_bit(struct log_c *l,
 271                                  uint32_t *bs, unsigned bit)
 272 {
 273         __clear_bit_le(bit, bs);
 274         l->touched_dirtied = 1;
 275 }
 276
 277 /*----------------------------------------------------------------
 278  * Header IO
 279  *--------------------------------------------------------------*/
 280 static void header_to_disk(struct log_header_core *core, struct log_header_disk *disk)
 281 {
 282         disk->magic = cpu_to_le32(core->magic);
 283         disk->version = cpu_to_le32(core->version);
 284         disk->nr_regions = cpu_to_le64(core->nr_regions);
 285 }
 286
 287 static void header_from_disk(struct log_header_core *core, struct log_header_disk *disk)
 288 {
 289         core->magic = le32_to_cpu(disk->magic);
 290         core->version = le32_to_cpu(disk->version);
 291         core->nr_regions = le64_to_cpu(disk->nr_regions);
 292 }
 293
 294 static int rw_header(struct log_c *lc, int rw)
 295 {
 296         lc->io_req.bi_op = rw;
 297
 298         return dm_io(&lc->io_req, 1, &lc->header_location, NULL);
 299 }
 300
 301 static int flush_header(struct log_c *lc)
 302 {
 303         struct dm_io_region null_location = {
 304                 .bdev = lc->header_location.bdev,
 305                 .sector = 0,
 306                 .count = 0,
 307         };
 308
 309         lc->io_req.bi_op = REQ_OP_WRITE;
 310         lc->io_req.bi_op_flags = WRITE_FLUSH;
 311
 312         return dm_io(&lc->io_req, 1, &null_location, NULL);
 313 }
 314
 315 static int read_header(struct log_c *log)
 316 {
 317         int r;
 318
 319         r = rw_header(log, READ);
 320         if (r)
 321                 return r;
 322
 323         header_from_disk(&log->header, log->disk_header);
 324
 325         /* New log required? */
 326         if (log->sync != DEFAULTSYNC || log->header.magic != MIRROR_MAGIC) {
 327                 log->header.magic = MIRROR_MAGIC;
 328                 log->header.version = MIRROR_DISK_VERSION;
 329                 log->header.nr_regions = 0;
 330         }
 331
 332 #ifdef __LITTLE_ENDIAN
 333         if (log->header.version == 1)
 334                 log->header.version = 2;
 335 #endif
 336
 337         if (log->header.version != MIRROR_DISK_VERSION) {
 338                 DMWARN("incompatible disk log version");
 339                 return -EINVAL;
 340         }
 341
 342         return 0;
 343 }
 344
 345 static int _check_region_size(struct dm_target *ti, uint32_t region_size)
 346 {
 347         if (region_size < 2 || region_size > ti->len)
 348                 return 0;
 349
 350         if (!is_power_of_2(region_size))
 351                 return 0;
 352
 353         return 1;
 354 }
 355
 356 /*----------------------------------------------------------------
 357  * core log constructor/destructor
 358  *
 359  * argv contains region_size followed optionally by [no]sync
 360  *--------------------------------------------------------------*/
 361 #define BYTE_SHIFT 3
 362 static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti,
 363                               unsigned int argc, char **argv,
 364                               struct dm_dev *dev)
 365 {
 366         enum sync sync = DEFAULTSYNC;
 367
 368         struct log_c *lc;
 369         uint32_t region_size;
 370         unsigned int region_count;
 371         size_t bitset_size, buf_size;
 372         int r;
 373         char dummy;
 374
 375         if (argc < 1 || argc > 2) {
 376                 DMWARN("wrong number of arguments to dirty region log");
 377                 return -EINVAL;
 378         }
 379
 380         if (argc > 1) {
 381                 if (!strcmp(argv[1], "sync"))
 382                         sync = FORCESYNC;
 383                 else if (!strcmp(argv[1], "nosync"))
 384                         sync = NOSYNC;
 385                 else {
 386                         DMWARN("unrecognised sync argument to "
 387                                "dirty region log: %s", argv[1]);
 388                         return -EINVAL;
 389                 }
 390         }
 391
 392         if (sscanf(argv[0], "%u%c", &region_size, &dummy) != 1 ||
 393             !_check_region_size(ti, region_size)) {
 394                 DMWARN("invalid region size %s", argv[0]);
 395                 return -EINVAL;
 396         }
 397
 398         region_count = dm_sector_div_up(ti->len, region_size);
 399
 400         lc = kmalloc(sizeof(*lc), GFP_KERNEL);
 401         if (!lc) {
 402                 DMWARN("couldn't allocate core log");
 403                 return -ENOMEM;
 404         }
 405
 406         lc->ti = ti;
 407         lc->touched_dirtied = 0;
 408         lc->touched_cleaned = 0;
 409         lc->flush_failed = 0;
 410         lc->region_size = region_size;
 411         lc->region_count = region_count;
 412         lc->sync = sync;
 413
 414         /*
 415          * Work out how many "unsigned long"s we need to hold the bitset.
 416          */
 417         bitset_size = dm_round_up(region_count,
 418                                   sizeof(*lc->clean_bits) << BYTE_SHIFT);
 419         bitset_size >>= BYTE_SHIFT;
 420
 421         lc->bitset_uint32_count = bitset_size / sizeof(*lc->clean_bits);
 422
 423         /*
 424          * Disk log?
 425          */
 426         if (!dev) {
 427                 lc->clean_bits = vmalloc(bitset_size);
 428                 if (!lc->clean_bits) {
 429                         DMWARN("couldn't allocate clean bitset");
 430                         kfree(lc);
 431                         return -ENOMEM;
 432                 }
 433                 lc->disk_header = NULL;
 434         } else {
 435                 lc->log_dev = dev;
 436                 lc->log_dev_failed = 0;
 437                 lc->log_dev_flush_failed = 0;
 438                 lc->header_location.bdev = lc->log_dev->bdev;
 439                 lc->header_location.sector = 0;
 440
 441                 /*
 442                  * Buffer holds both header and bitset.
 443                  */
 444                 buf_size =
 445                     dm_round_up((LOG_OFFSET << SECTOR_SHIFT) + bitset_size,
 446                                 bdev_logical_block_size(lc->header_location.
 447                                                             bdev));
 448
 449                 if (buf_size > i_size_read(dev->bdev->bd_inode)) {
 450                         DMWARN("log device %s too small: need %llu bytes",
 451                                 dev->name, (unsigned long long)buf_size);
 452                         kfree(lc);
 453                         return -EINVAL;
 454                 }
 455
 456                 lc->header_location.count = buf_size >> SECTOR_SHIFT;
 457
 458                 lc->io_req.mem.type = DM_IO_VMA;
 459                 lc->io_req.notify.fn = NULL;
 460                 lc->io_req.client = dm_io_client_create();
 461                 if (IS_ERR(lc->io_req.client)) {
 462                         r = PTR_ERR(lc->io_req.client);
 463                         DMWARN("couldn't allocate disk io client");
 464                         kfree(lc);
 465                         return r;
 466                 }
 467
 468                 lc->disk_header = vmalloc(buf_size);
 469                 if (!lc->disk_header) {
 470                         DMWARN("couldn't allocate disk log buffer");
 471                         dm_io_client_destroy(lc->io_req.client);
 472                         kfree(lc);
 473                         return -ENOMEM;
 474                 }
 475
 476                 lc->io_req.mem.ptr.vma = lc->disk_header;
 477                 lc->clean_bits = (void *)lc->disk_header +
 478                                  (LOG_OFFSET << SECTOR_SHIFT);
 479         }
 480
 481         memset(lc->clean_bits, -1, bitset_size);
 482
 483         lc->sync_bits = vmalloc(bitset_size);
 484         if (!lc->sync_bits) {
 485                 DMWARN("couldn't allocate sync bitset");
 486                 if (!dev)
 487                         vfree(lc->clean_bits);
 488                 else
 489                         dm_io_client_destroy(lc->io_req.client);
 490                 vfree(lc->disk_header);
 491                 kfree(lc);
 492                 return -ENOMEM;
 493         }
 494         memset(lc->sync_bits, (sync == NOSYNC) ? -1 : 0, bitset_size);
 495         lc->sync_count = (sync == NOSYNC) ? region_count : 0;
 496
 497         lc->recovering_bits = vzalloc(bitset_size);
 498         if (!lc->recovering_bits) {
 499                 DMWARN("couldn't allocate sync bitset");
 500                 vfree(lc->sync_bits);
 501                 if (!dev)
 502                         vfree(lc->clean_bits);
 503                 else
 504                         dm_io_client_destroy(lc->io_req.client);
 505                 vfree(lc->disk_header);
 506                 kfree(lc);
 507                 return -ENOMEM;
 508         }
 509         lc->sync_search = 0;
 510         log->context = lc;
 511
 512         return 0;
 513 }
 514
 515 static int core_ctr(struct dm_dirty_log *log, struct dm_target *ti,
 516                     unsigned int argc, char **argv)
 517 {
 518         return create_log_context(log, ti, argc, argv, NULL);
 519 }
 520
 521 static void destroy_log_context(struct log_c *lc)
 522 {
 523         vfree(lc->sync_bits);
 524         vfree(lc->recovering_bits);
 525         kfree(lc);
 526 }
 527
 528 static void core_dtr(struct dm_dirty_log *log)
 529 {
 530         struct log_c *lc = (struct log_c *) log->context;
 531
 532         vfree(lc->clean_bits);
 533         destroy_log_context(lc);
 534 }
 535
 536 /*----------------------------------------------------------------
 537  * disk log constructor/destructor
 538  *
 539  * argv contains log_device region_size followed optionally by [no]sync
 540  *--------------------------------------------------------------*/
 541 static int disk_ctr(struct dm_dirty_log *log, struct dm_target *ti,
 542                     unsigned int argc, char **argv)
 543 {
 544         int r;
 545         struct dm_dev *dev;
 546
 547         if (argc < 2 || argc > 3) {
 548                 DMWARN("wrong number of arguments to disk dirty region log");
 549                 return -EINVAL;
 550         }
 551
 552         r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &dev);
 553         if (r)
 554                 return r;
 555
 556         r = create_log_context(log, ti, argc - 1, argv + 1, dev);
 557         if (r) {
 558                 dm_put_device(ti, dev);
 559                 return r;
 560         }
 561
 562         return 0;
 563 }
 564
 565 static void disk_dtr(struct dm_dirty_log *log)
 566 {
 567         struct log_c *lc = (struct log_c *) log->context;
 568
 569         dm_put_device(lc->ti, lc->log_dev);
 570         vfree(lc->disk_header);
 571         dm_io_client_destroy(lc->io_req.client);
 572         destroy_log_context(lc);
 573 }
 574
 575 static void fail_log_device(struct log_c *lc)
 576 {
 577         if (lc->log_dev_failed)
 578                 return;
 579
 580         lc->log_dev_failed = 1;
 581         dm_table_event(lc->ti->table);
 582 }
 583
 584 static int disk_resume(struct dm_dirty_log *log)
 585 {
 586         int r;
 587         unsigned i;
 588         struct log_c *lc = (struct log_c *) log->context;
 589         size_t size = lc->bitset_uint32_count * sizeof(uint32_t);
 590
 591         /* read the disk header */
 592         r = read_header(lc);
 593         if (r) {
 594                 DMWARN("%s: Failed to read header on dirty region log device",
 595                        lc->log_dev->name);
 596                 fail_log_device(lc);
 597                 /*
 598                  * If the log device cannot be read, we must assume
 599                  * all regions are out-of-sync.  If we simply return
 600                  * here, the state will be uninitialized and could
 601                  * lead us to return 'in-sync' status for regions
 602                  * that are actually 'out-of-sync'.
 603                  */
 604                 lc->header.nr_regions = 0;
 605         }
 606
 607         /* set or clear any new bits -- device has grown */
 608         if (lc->sync == NOSYNC)
 609                 for (i = lc->header.nr_regions; i < lc->region_count; i++)
 610                         /* FIXME: amazingly inefficient */
 611                         log_set_bit(lc, lc->clean_bits, i);
 612         else
 613                 for (i = lc->header.nr_regions; i < lc->region_count; i++)
 614                         /* FIXME: amazingly inefficient */
 615                         log_clear_bit(lc, lc->clean_bits, i);
 616
 617         /* clear any old bits -- device has shrunk */
 618         for (i = lc->region_count; i % (sizeof(*lc->clean_bits) << BYTE_SHIFT); i++)
 619                 log_clear_bit(lc, lc->clean_bits, i);
 620
 621         /* copy clean across to sync */
 622         memcpy(lc->sync_bits, lc->clean_bits, size);
 623         lc->sync_count = memweight(lc->clean_bits,
 624                                 lc->bitset_uint32_count * sizeof(uint32_t));
 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                         lc->log_dev_flush_failed = 1;
 638         }
 639         if (r) {
 640                 DMWARN("%s: Failed to write header on dirty region log device",
 641                        lc->log_dev->name);
 642                 fail_log_device(lc);
 643         }
 644
 645         return r;
 646 }
 647
 648 static uint32_t core_get_region_size(struct dm_dirty_log *log)
 649 {
 650         struct log_c *lc = (struct log_c *) log->context;
 651         return lc->region_size;
 652 }
 653
 654 static int core_resume(struct dm_dirty_log *log)
 655 {
 656         struct log_c *lc = (struct log_c *) log->context;
 657         lc->sync_search = 0;
 658         return 0;
 659 }
 660
 661 static int core_is_clean(struct dm_dirty_log *log, region_t region)
 662 {
 663         struct log_c *lc = (struct log_c *) log->context;
 664         return log_test_bit(lc->clean_bits, region);
 665 }
 666
 667 static int core_in_sync(struct dm_dirty_log *log, region_t region, int block)
 668 {
 669         struct log_c *lc = (struct log_c *) log->context;
 670         return log_test_bit(lc->sync_bits, region);
 671 }
 672
 673 static int core_flush(struct dm_dirty_log *log)
 674 {
 675         /* no op */
 676         return 0;
 677 }
 678
 679 static int disk_flush(struct dm_dirty_log *log)
 680 {
 681         int r, i;
 682         struct log_c *lc = log->context;
 683
 684         /* only write if the log has changed */
 685         if (!lc->touched_cleaned && !lc->touched_dirtied)
 686                 return 0;
 687
 688         if (lc->touched_cleaned && log->flush_callback_fn &&
 689             log->flush_callback_fn(lc->ti)) {
 690                 /*
 691                  * At this point it is impossible to determine which
 692                  * regions are clean and which are dirty (without
 693                  * re-reading the log off disk). So mark all of them
 694                  * dirty.
 695                  */
 696                 lc->flush_failed = 1;
 697                 for (i = 0; i < lc->region_count; i++)
 698                         log_clear_bit(lc, lc->clean_bits, i);
 699         }
 700
 701         r = rw_header(lc, WRITE);
 702         if (r)
 703                 fail_log_device(lc);
 704         else {
 705                 if (lc->touched_dirtied) {
 706                         r = flush_header(lc);
 707                         if (r) {
 708                                 lc->log_dev_flush_failed = 1;
 709                                 fail_log_device(lc);
 710                         } else
 711                                 lc->touched_dirtied = 0;
 712                 }
 713                 lc->touched_cleaned = 0;
 714         }
 715
 716         return r;
 717 }
 718
 719 static void core_mark_region(struct dm_dirty_log *log, region_t region)
 720 {
 721         struct log_c *lc = (struct log_c *) log->context;
 722         log_clear_bit(lc, lc->clean_bits, region);
 723 }
 724
 725 static void core_clear_region(struct dm_dirty_log *log, region_t region)
 726 {
 727         struct log_c *lc = (struct log_c *) log->context;
 728         if (likely(!lc->flush_failed))
 729                 log_set_bit(lc, lc->clean_bits, region);
 730 }
 731
 732 static int core_get_resync_work(struct dm_dirty_log *log, region_t *region)
 733 {
 734         struct log_c *lc = (struct log_c *) log->context;
 735
 736         if (lc->sync_search >= lc->region_count)
 737                 return 0;
 738
 739         do {
 740                 *region = find_next_zero_bit_le(lc->sync_bits,
 741                                              lc->region_count,
 742                                              lc->sync_search);
 743                 lc->sync_search = *region + 1;
 744
 745                 if (*region >= lc->region_count)
 746                         return 0;
 747
 748         } while (log_test_bit(lc->recovering_bits, *region));
 749
 750         log_set_bit(lc, lc->recovering_bits, *region);
 751         return 1;
 752 }
 753
 754 static void core_set_region_sync(struct dm_dirty_log *log, region_t region,
 755                                  int in_sync)
 756 {
 757         struct log_c *lc = (struct log_c *) log->context;
 758
 759         log_clear_bit(lc, lc->recovering_bits, region);
 760         if (in_sync) {
 761                 log_set_bit(lc, lc->sync_bits, region);
 762                 lc->sync_count++;
 763         } else if (log_test_bit(lc->sync_bits, region)) {
 764                 lc->sync_count--;
 765                 log_clear_bit(lc, lc->sync_bits, region);
 766         }
 767 }
 768
 769 static region_t core_get_sync_count(struct dm_dirty_log *log)
 770 {
 771         struct log_c *lc = (struct log_c *) log->context;
 772
 773         return lc->sync_count;
 774 }
 775
 776 #define DMEMIT_SYNC \
 777         if (lc->sync != DEFAULTSYNC) \
 778                 DMEMIT("%ssync ", lc->sync == NOSYNC ? "no" : "")
 779
 780 static int core_status(struct dm_dirty_log *log, status_type_t status,
 781                        char *result, unsigned int maxlen)
 782 {
 783         int sz = 0;
 784         struct log_c *lc = log->context;
 785
 786         switch(status) {
 787         case STATUSTYPE_INFO:
 788                 DMEMIT("1 %s", log->type->name);
 789                 break;
 790
 791         case STATUSTYPE_TABLE:
 792                 DMEMIT("%s %u %u ", log->type->name,
 793                        lc->sync == DEFAULTSYNC ? 1 : 2, lc->region_size);
 794                 DMEMIT_SYNC;
 795         }
 796
 797         return sz;
 798 }
 799
 800 static int disk_status(struct dm_dirty_log *log, status_type_t status,
 801                        char *result, unsigned int maxlen)
 802 {
 803         int sz = 0;
 804         struct log_c *lc = log->context;
 805
 806         switch(status) {
 807         case STATUSTYPE_INFO:
 808                 DMEMIT("3 %s %s %c", log->type->name, lc->log_dev->name,
 809                        lc->log_dev_flush_failed ? 'F' :
 810                        lc->log_dev_failed ? 'D' :
 811                        'A');
 812                 break;
 813
 814         case STATUSTYPE_TABLE:
 815                 DMEMIT("%s %u %s %u ", log->type->name,
 816                        lc->sync == DEFAULTSYNC ? 2 : 3, lc->log_dev->name,
 817                        lc->region_size);
 818                 DMEMIT_SYNC;
 819         }
 820
 821         return sz;
 822 }
 823
 824 static struct dm_dirty_log_type _core_type = {
 825         .name = "core",
 826         .module = THIS_MODULE,
 827         .ctr = core_ctr,
 828         .dtr = core_dtr,
 829         .resume = core_resume,
 830         .get_region_size = core_get_region_size,
 831         .is_clean = core_is_clean,
 832         .in_sync = core_in_sync,
 833         .flush = core_flush,
 834         .mark_region = core_mark_region,
 835         .clear_region = core_clear_region,
 836         .get_resync_work = core_get_resync_work,
 837         .set_region_sync = core_set_region_sync,
 838         .get_sync_count = core_get_sync_count,
 839         .status = core_status,
 840 };
 841
 842 static struct dm_dirty_log_type _disk_type = {
 843         .name = "disk",
 844         .module = THIS_MODULE,
 845         .ctr = disk_ctr,
 846         .dtr = disk_dtr,
 847         .postsuspend = disk_flush,
 848         .resume = disk_resume,
 849         .get_region_size = core_get_region_size,
 850         .is_clean = core_is_clean,
 851         .in_sync = core_in_sync,
 852         .flush = disk_flush,
 853         .mark_region = core_mark_region,
 854         .clear_region = core_clear_region,
 855         .get_resync_work = core_get_resync_work,
 856         .set_region_sync = core_set_region_sync,
 857         .get_sync_count = core_get_sync_count,
 858         .status = disk_status,
 859 };
 860
 861 static int __init dm_dirty_log_init(void)
 862 {
 863         int r;
 864
 865         r = dm_dirty_log_type_register(&_core_type);
 866         if (r)
 867                 DMWARN("couldn't register core log");
 868
 869         r = dm_dirty_log_type_register(&_disk_type);
 870         if (r) {
 871                 DMWARN("couldn't register disk type");
 872                 dm_dirty_log_type_unregister(&_core_type);
 873         }
 874
 875         return r;
 876 }
 877
 878 static void __exit dm_dirty_log_exit(void)
 879 {
 880         dm_dirty_log_type_unregister(&_disk_type);
 881         dm_dirty_log_type_unregister(&_core_type);
 882 }
 883
 884 module_init(dm_dirty_log_init);
 885 module_exit(dm_dirty_log_exit);
 886
 887 MODULE_DESCRIPTION(DM_NAME " dirty region log");
 888 MODULE_AUTHOR("Joe Thornber, Heinz Mauelshagen <dm-devel@redhat.com>");
 889 MODULE_LICENSE("GPL");