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 "dm.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         lc->io_req.mem.ptr.vma = lc->disk_header;
 330         lc->io_req.notify.fn = NULL;
 331
 332         return dm_io(&lc->io_req, 1, &lc->header_location, NULL);
 333 }
 334
 335 static int read_header(struct log_c *log)
 336 {
 337         int r;
 338
 339         r = rw_header(log, READ);
 340         if (r)
 341                 return r;
 342
 343         header_from_disk(&log->header, log->disk_header);
 344
 345         /* New log required? */
 346         if (log->sync != DEFAULTSYNC || log->header.magic != MIRROR_MAGIC) {
 347                 log->header.magic = MIRROR_MAGIC;
 348                 log->header.version = MIRROR_DISK_VERSION;
 349                 log->header.nr_regions = 0;
 350         }
 351
 352 #ifdef __LITTLE_ENDIAN
 353         if (log->header.version == 1)
 354                 log->header.version = 2;
 355 #endif
 356
 357         if (log->header.version != MIRROR_DISK_VERSION) {
 358                 DMWARN("incompatible disk log version");
 359                 return -EINVAL;
 360         }
 361
 362         return 0;
 363 }
 364
 365 static inline int write_header(struct log_c *log)
 366 {
 367         header_to_disk(&log->header, log->disk_header);
 368         return rw_header(log, WRITE);
 369 }
 370
 371 /*----------------------------------------------------------------
 372  * core log constructor/destructor
 373  *
 374  * argv contains region_size followed optionally by [no]sync
 375  *--------------------------------------------------------------*/
 376 #define BYTE_SHIFT 3
 377 static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti,
 378                               unsigned int argc, char **argv,
 379                               struct dm_dev *dev)
 380 {
 381         enum sync sync = DEFAULTSYNC;
 382
 383         struct log_c *lc;
 384         uint32_t region_size;
 385         unsigned int region_count;
 386         size_t bitset_size, buf_size;
 387         int r;
 388
 389         if (argc < 1 || argc > 2) {
 390                 DMWARN("wrong number of arguments to dirty region log");
 391                 return -EINVAL;
 392         }
 393
 394         if (argc > 1) {
 395                 if (!strcmp(argv[1], "sync"))
 396                         sync = FORCESYNC;
 397                 else if (!strcmp(argv[1], "nosync"))
 398                         sync = NOSYNC;
 399                 else {
 400                         DMWARN("unrecognised sync argument to "
 401                                "dirty region log: %s", argv[1]);
 402                         return -EINVAL;
 403                 }
 404         }
 405
 406         if (sscanf(argv[0], "%u", &region_size) != 1) {
 407                 DMWARN("invalid region size string");
 408                 return -EINVAL;
 409         }
 410
 411         region_count = dm_sector_div_up(ti->len, region_size);
 412
 413         lc = kmalloc(sizeof(*lc), GFP_KERNEL);
 414         if (!lc) {
 415                 DMWARN("couldn't allocate core log");
 416                 return -ENOMEM;
 417         }
 418
 419         lc->ti = ti;
 420         lc->touched = 0;
 421         lc->region_size = region_size;
 422         lc->region_count = region_count;
 423         lc->sync = sync;
 424
 425         /*
 426          * Work out how many "unsigned long"s we need to hold the bitset.
 427          */
 428         bitset_size = dm_round_up(region_count,
 429                                   sizeof(*lc->clean_bits) << BYTE_SHIFT);
 430         bitset_size >>= BYTE_SHIFT;
 431
 432         lc->bitset_uint32_count = bitset_size / sizeof(*lc->clean_bits);
 433
 434         /*
 435          * Disk log?
 436          */
 437         if (!dev) {
 438                 lc->clean_bits = vmalloc(bitset_size);
 439                 if (!lc->clean_bits) {
 440                         DMWARN("couldn't allocate clean bitset");
 441                         kfree(lc);
 442                         return -ENOMEM;
 443                 }
 444                 lc->disk_header = NULL;
 445         } else {
 446                 lc->log_dev = dev;
 447                 lc->log_dev_failed = 0;
 448                 lc->header_location.bdev = lc->log_dev->bdev;
 449                 lc->header_location.sector = 0;
 450
 451                 /*
 452                  * Buffer holds both header and bitset.
 453                  */
 454                 buf_size = dm_round_up((LOG_OFFSET << SECTOR_SHIFT) +
 455                                        bitset_size, ti->limits.hardsect_size);
 456                 lc->header_location.count = buf_size >> SECTOR_SHIFT;
 457                 lc->io_req.mem.type = DM_IO_VMA;
 458                 lc->io_req.client = dm_io_client_create(dm_div_up(buf_size,
 459                                                                    PAGE_SIZE));
 460                 if (IS_ERR(lc->io_req.client)) {
 461                         r = PTR_ERR(lc->io_req.client);
 462                         DMWARN("couldn't allocate disk io client");
 463                         kfree(lc);
 464                         return -ENOMEM;
 465                 }
 466
 467                 lc->disk_header = vmalloc(buf_size);
 468                 if (!lc->disk_header) {
 469                         DMWARN("couldn't allocate disk log buffer");
 470                         dm_io_client_destroy(lc->io_req.client);
 471                         kfree(lc);
 472                         return -ENOMEM;
 473                 }
 474
 475                 lc->clean_bits = (void *)lc->disk_header +
 476                                  (LOG_OFFSET << SECTOR_SHIFT);
 477         }
 478
 479         memset(lc->clean_bits, -1, bitset_size);
 480
 481         lc->sync_bits = vmalloc(bitset_size);
 482         if (!lc->sync_bits) {
 483                 DMWARN("couldn't allocate sync bitset");
 484                 if (!dev)
 485                         vfree(lc->clean_bits);
 486                 else
 487                         dm_io_client_destroy(lc->io_req.client);
 488                 vfree(lc->disk_header);
 489                 kfree(lc);
 490                 return -ENOMEM;
 491         }
 492         memset(lc->sync_bits, (sync == NOSYNC) ? -1 : 0, bitset_size);
 493         lc->sync_count = (sync == NOSYNC) ? region_count : 0;
 494
 495         lc->recovering_bits = vmalloc(bitset_size);
 496         if (!lc->recovering_bits) {
 497                 DMWARN("couldn't allocate sync bitset");
 498                 vfree(lc->sync_bits);
 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->recovering_bits, 0, bitset_size);
 508         lc->sync_search = 0;
 509         log->context = lc;
 510
 511         return 0;
 512 }
 513
 514 static int core_ctr(struct dm_dirty_log *log, struct dm_target *ti,
 515                     unsigned int argc, char **argv)
 516 {
 517         return create_log_context(log, ti, argc, argv, NULL);
 518 }
 519
 520 static void destroy_log_context(struct log_c *lc)
 521 {
 522         vfree(lc->sync_bits);
 523         vfree(lc->recovering_bits);
 524         kfree(lc);
 525 }
 526
 527 static void core_dtr(struct dm_dirty_log *log)
 528 {
 529         struct log_c *lc = (struct log_c *) log->context;
 530
 531         vfree(lc->clean_bits);
 532         destroy_log_context(lc);
 533 }
 534
 535 /*----------------------------------------------------------------
 536  * disk log constructor/destructor
 537  *
 538  * argv contains log_device region_size followed optionally by [no]sync
 539  *--------------------------------------------------------------*/
 540 static int disk_ctr(struct dm_dirty_log *log, struct dm_target *ti,
 541                     unsigned int argc, char **argv)
 542 {
 543         int r;
 544         struct dm_dev *dev;
 545
 546         if (argc < 2 || argc > 3) {
 547                 DMWARN("wrong number of arguments to disk dirty region log");
 548                 return -EINVAL;
 549         }
 550
 551         r = dm_get_device(ti, argv[0], 0, 0 /* FIXME */,
 552                           FMODE_READ | FMODE_WRITE, &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 int count_bits32(uint32_t *addr, unsigned size)
 576 {
 577         int count = 0, i;
 578
 579         for (i = 0; i < size; i++) {
 580                 count += hweight32(*(addr+i));
 581         }
 582         return count;
 583 }
 584
 585 static void fail_log_device(struct log_c *lc)
 586 {
 587         if (lc->log_dev_failed)
 588                 return;
 589
 590         lc->log_dev_failed = 1;
 591         dm_table_event(lc->ti->table);
 592 }
 593
 594 static int disk_resume(struct dm_dirty_log *log)
 595 {
 596         int r;
 597         unsigned i;
 598         struct log_c *lc = (struct log_c *) log->context;
 599         size_t size = lc->bitset_uint32_count * sizeof(uint32_t);
 600
 601         /* read the disk header */
 602         r = read_header(lc);
 603         if (r) {
 604                 DMWARN("%s: Failed to read header on dirty region log device",
 605                        lc->log_dev->name);
 606                 fail_log_device(lc);
 607                 /*
 608                  * If the log device cannot be read, we must assume
 609                  * all regions are out-of-sync.  If we simply return
 610                  * here, the state will be uninitialized and could
 611                  * lead us to return 'in-sync' status for regions
 612                  * that are actually 'out-of-sync'.
 613                  */
 614                 lc->header.nr_regions = 0;
 615         }
 616
 617         /* set or clear any new bits -- device has grown */
 618         if (lc->sync == NOSYNC)
 619                 for (i = lc->header.nr_regions; i < lc->region_count; i++)
 620                         /* FIXME: amazingly inefficient */
 621                         log_set_bit(lc, lc->clean_bits, i);
 622         else
 623                 for (i = lc->header.nr_regions; i < lc->region_count; i++)
 624                         /* FIXME: amazingly inefficient */
 625                         log_clear_bit(lc, lc->clean_bits, i);
 626
 627         /* clear any old bits -- device has shrunk */
 628         for (i = lc->region_count; i % (sizeof(*lc->clean_bits) << BYTE_SHIFT); i++)
 629                 log_clear_bit(lc, lc->clean_bits, i);
 630
 631         /* copy clean across to sync */
 632         memcpy(lc->sync_bits, lc->clean_bits, size);
 633         lc->sync_count = count_bits32(lc->clean_bits, lc->bitset_uint32_count);
 634         lc->sync_search = 0;
 635
 636         /* set the correct number of regions in the header */
 637         lc->header.nr_regions = lc->region_count;
 638
 639         /* write the new header */
 640         r = write_header(lc);
 641         if (r) {
 642                 DMWARN("%s: Failed to write header on dirty region log device",
 643                        lc->log_dev->name);
 644                 fail_log_device(lc);
 645         }
 646
 647         return r;
 648 }
 649
 650 static uint32_t core_get_region_size(struct dm_dirty_log *log)
 651 {
 652         struct log_c *lc = (struct log_c *) log->context;
 653         return lc->region_size;
 654 }
 655
 656 static int core_resume(struct dm_dirty_log *log)
 657 {
 658         struct log_c *lc = (struct log_c *) log->context;
 659         lc->sync_search = 0;
 660         return 0;
 661 }
 662
 663 static int core_is_clean(struct dm_dirty_log *log, region_t region)
 664 {
 665         struct log_c *lc = (struct log_c *) log->context;
 666         return log_test_bit(lc->clean_bits, region);
 667 }
 668
 669 static int core_in_sync(struct dm_dirty_log *log, region_t region, int block)
 670 {
 671         struct log_c *lc = (struct log_c *) log->context;
 672         return log_test_bit(lc->sync_bits, region);
 673 }
 674
 675 static int core_flush(struct dm_dirty_log *log)
 676 {
 677         /* no op */
 678         return 0;
 679 }
 680
 681 static int disk_flush(struct dm_dirty_log *log)
 682 {
 683         int r;
 684         struct log_c *lc = (struct log_c *) log->context;
 685
 686         /* only write if the log has changed */
 687         if (!lc->touched)
 688                 return 0;
 689
 690         r = write_header(lc);
 691         if (r)
 692                 fail_log_device(lc);
 693         else
 694                 lc->touched = 0;
 695
 696         return r;
 697 }
 698
 699 static void core_mark_region(struct dm_dirty_log *log, region_t region)
 700 {
 701         struct log_c *lc = (struct log_c *) log->context;
 702         log_clear_bit(lc, lc->clean_bits, region);
 703 }
 704
 705 static void core_clear_region(struct dm_dirty_log *log, region_t region)
 706 {
 707         struct log_c *lc = (struct log_c *) log->context;
 708         log_set_bit(lc, lc->clean_bits, region);
 709 }
 710
 711 static int core_get_resync_work(struct dm_dirty_log *log, region_t *region)
 712 {
 713         struct log_c *lc = (struct log_c *) log->context;
 714
 715         if (lc->sync_search >= lc->region_count)
 716                 return 0;
 717
 718         do {
 719                 *region = ext2_find_next_zero_bit(
 720                                              (unsigned long *) lc->sync_bits,
 721                                              lc->region_count,
 722                                              lc->sync_search);
 723                 lc->sync_search = *region + 1;
 724
 725                 if (*region >= lc->region_count)
 726                         return 0;
 727
 728         } while (log_test_bit(lc->recovering_bits, *region));
 729
 730         log_set_bit(lc, lc->recovering_bits, *region);
 731         return 1;
 732 }
 733
 734 static void core_set_region_sync(struct dm_dirty_log *log, region_t region,
 735                                  int in_sync)
 736 {
 737         struct log_c *lc = (struct log_c *) log->context;
 738
 739         log_clear_bit(lc, lc->recovering_bits, region);
 740         if (in_sync) {
 741                 log_set_bit(lc, lc->sync_bits, region);
 742                 lc->sync_count++;
 743         } else if (log_test_bit(lc->sync_bits, region)) {
 744                 lc->sync_count--;
 745                 log_clear_bit(lc, lc->sync_bits, region);
 746         }
 747 }
 748
 749 static region_t core_get_sync_count(struct dm_dirty_log *log)
 750 {
 751         struct log_c *lc = (struct log_c *) log->context;
 752
 753         return lc->sync_count;
 754 }
 755
 756 #define DMEMIT_SYNC \
 757         if (lc->sync != DEFAULTSYNC) \
 758                 DMEMIT("%ssync ", lc->sync == NOSYNC ? "no" : "")
 759
 760 static int core_status(struct dm_dirty_log *log, status_type_t status,
 761                        char *result, unsigned int maxlen)
 762 {
 763         int sz = 0;
 764         struct log_c *lc = log->context;
 765
 766         switch(status) {
 767         case STATUSTYPE_INFO:
 768                 DMEMIT("1 %s", log->type->name);
 769                 break;
 770
 771         case STATUSTYPE_TABLE:
 772                 DMEMIT("%s %u %u ", log->type->name,
 773                        lc->sync == DEFAULTSYNC ? 1 : 2, lc->region_size);
 774                 DMEMIT_SYNC;
 775         }
 776
 777         return sz;
 778 }
 779
 780 static int disk_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("3 %s %s %c", log->type->name, lc->log_dev->name,
 789                        lc->log_dev_failed ? 'D' : 'A');
 790                 break;
 791
 792         case STATUSTYPE_TABLE:
 793                 DMEMIT("%s %u %s %u ", log->type->name,
 794                        lc->sync == DEFAULTSYNC ? 2 : 3, lc->log_dev->name,
 795                        lc->region_size);
 796                 DMEMIT_SYNC;
 797         }
 798
 799         return sz;
 800 }
 801
 802 static struct dm_dirty_log_type _core_type = {
 803         .name = "core",
 804         .module = THIS_MODULE,
 805         .ctr = core_ctr,
 806         .dtr = core_dtr,
 807         .resume = core_resume,
 808         .get_region_size = core_get_region_size,
 809         .is_clean = core_is_clean,
 810         .in_sync = core_in_sync,
 811         .flush = core_flush,
 812         .mark_region = core_mark_region,
 813         .clear_region = core_clear_region,
 814         .get_resync_work = core_get_resync_work,
 815         .set_region_sync = core_set_region_sync,
 816         .get_sync_count = core_get_sync_count,
 817         .status = core_status,
 818 };
 819
 820 static struct dm_dirty_log_type _disk_type = {
 821         .name = "disk",
 822         .module = THIS_MODULE,
 823         .ctr = disk_ctr,
 824         .dtr = disk_dtr,
 825         .postsuspend = disk_flush,
 826         .resume = disk_resume,
 827         .get_region_size = core_get_region_size,
 828         .is_clean = core_is_clean,
 829         .in_sync = core_in_sync,
 830         .flush = disk_flush,
 831         .mark_region = core_mark_region,
 832         .clear_region = core_clear_region,
 833         .get_resync_work = core_get_resync_work,
 834         .set_region_sync = core_set_region_sync,
 835         .get_sync_count = core_get_sync_count,
 836         .status = disk_status,
 837 };
 838
 839 static int __init dm_dirty_log_init(void)
 840 {
 841         int r;
 842
 843         r = dm_dirty_log_type_register(&_core_type);
 844         if (r)
 845                 DMWARN("couldn't register core log");
 846
 847         r = dm_dirty_log_type_register(&_disk_type);
 848         if (r) {
 849                 DMWARN("couldn't register disk type");
 850                 dm_dirty_log_type_unregister(&_core_type);
 851         }
 852
 853         return r;
 854 }
 855
 856 static void __exit dm_dirty_log_exit(void)
 857 {
 858         dm_dirty_log_type_unregister(&_disk_type);
 859         dm_dirty_log_type_unregister(&_core_type);
 860 }
 861
 862 module_init(dm_dirty_log_init);
 863 module_exit(dm_dirty_log_exit);
 864
 865 MODULE_DESCRIPTION(DM_NAME " dirty region log");
 866 MODULE_AUTHOR("Joe Thornber, Heinz Mauelshagen <dm-devel@redhat.com>");
 867 MODULE_LICENSE("GPL");