drivers/md/dm-log.c

   1 /*
   2  * Copyright (C) 2003 Sistina Software
   3  * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
   4  *
   5  * This file is released under the LGPL.
   6  */
   7
   8 #include <linux/init.h>
   9 #include <linux/slab.h>
  10 #include <linux/module.h>
  11 #include <linux/vmalloc.h>
  12 #include <linux/dm-io.h>
  13 #include <linux/dm-dirty-log.h>
  14
  15 #include <linux/device-mapper.h>
  16
  17 #define DM_MSG_PREFIX "dirty region log"
  18
  19 static LIST_HEAD(_log_types);
  20 static DEFINE_SPINLOCK(_lock);
  21
  22 static struct dm_dirty_log_type *__find_dirty_log_type(const char *name)
  23 {
  24         struct dm_dirty_log_type *log_type;
  25
  26         list_for_each_entry(log_type, &_log_types, list)
  27                 if (!strcmp(name, log_type->name))
  28                         return log_type;
  29
  30         return NULL;
  31 }
  32
  33 static struct dm_dirty_log_type *_get_dirty_log_type(const char *name)
  34 {
  35         struct dm_dirty_log_type *log_type;
  36
  37         spin_lock(&_lock);
  38
  39         log_type = __find_dirty_log_type(name);
  40         if (log_type && !try_module_get(log_type->module))
  41                 log_type = NULL;
  42
  43         spin_unlock(&_lock);
  44
  45         return log_type;
  46 }
  47
  48 /*
  49  * get_type
  50  * @type_name
  51  *
  52  * Attempt to retrieve the dm_dirty_log_type by name.  If not already
  53  * available, attempt to load the appropriate module.
  54  *
  55  * Log modules are named "dm-log-" followed by the 'type_name'.
  56  * Modules may contain multiple types.
  57  * This function will first try the module "dm-log-<type_name>",
  58  * then truncate 'type_name' on the last '-' and try again.
  59  *
  60  * For example, if type_name was "clustered-disk", it would search
  61  * 'dm-log-clustered-disk' then 'dm-log-clustered'.
  62  *
  63  * Returns: dirty_log_type* on success, NULL on failure
  64  */
  65 static struct dm_dirty_log_type *get_type(const char *type_name)
  66 {
  67         char *p, *type_name_dup;
  68         struct dm_dirty_log_type *log_type;
  69
  70         if (!type_name)
  71                 return NULL;
  72
  73         log_type = _get_dirty_log_type(type_name);
  74         if (log_type)
  75                 return log_type;
  76
  77         type_name_dup = kstrdup(type_name, GFP_KERNEL);
  78         if (!type_name_dup) {
  79                 DMWARN("No memory left to attempt log module load for \"%s\"",
  80                        type_name);
  81                 return NULL;
  82         }
  83
  84         while (request_module("dm-log-%s", type_name_dup) ||
  85                !(log_type = _get_dirty_log_type(type_name))) {
  86                 p = strrchr(type_name_dup, '-');
  87                 if (!p)
  88                         break;
  89                 p[0] = '\0';
  90         }
  91
  92         if (!log_type)
  93                 DMWARN("Module for logging type \"%s\" not found.", type_name);
  94
  95         kfree(type_name_dup);
  96
  97         return log_type;
  98 }
  99
 100 static void put_type(struct dm_dirty_log_type *type)
 101 {
 102         if (!type)
 103                 return;
 104
 105         spin_lock(&_lock);
 106         if (!__find_dirty_log_type(type->name))
 107                 goto out;
 108
 109         module_put(type->module);
 110
 111 out:
 112         spin_unlock(&_lock);
 113 }
 114
 115 int dm_dirty_log_type_register(struct dm_dirty_log_type *type)
 116 {
 117         int r = 0;
 118
 119         spin_lock(&_lock);
 120         if (!__find_dirty_log_type(type->name))
 121                 list_add(&type->list, &_log_types);
 122         else
 123                 r = -EEXIST;
 124         spin_unlock(&_lock);
 125
 126         return r;
 127 }
 128 EXPORT_SYMBOL(dm_dirty_log_type_register);
 129
 130 int dm_dirty_log_type_unregister(struct dm_dirty_log_type *type)
 131 {
 132         spin_lock(&_lock);
 133
 134         if (!__find_dirty_log_type(type->name)) {
 135                 spin_unlock(&_lock);
 136                 return -EINVAL;
 137         }
 138
 139         list_del(&type->list);
 140
 141         spin_unlock(&_lock);
 142
 143         return 0;
 144 }
 145 EXPORT_SYMBOL(dm_dirty_log_type_unregister);
 146
 147 struct dm_dirty_log *dm_dirty_log_create(const char *type_name,
 148                                          struct dm_target *ti,
 149                                          unsigned int argc, char **argv)
 150 {
 151         struct dm_dirty_log_type *type;
 152         struct dm_dirty_log *log;
 153
 154         log = kmalloc(sizeof(*log), GFP_KERNEL);
 155         if (!log)
 156                 return NULL;
 157
 158         type = get_type(type_name);
 159         if (!type) {
 160                 kfree(log);
 161                 return NULL;
 162         }
 163
 164         log->type = type;
 165         if (type->ctr(log, ti, argc, argv)) {
 166                 kfree(log);
 167                 put_type(type);
 168                 return NULL;
 169         }
 170
 171         return log;
 172 }
 173 EXPORT_SYMBOL(dm_dirty_log_create);
 174
 175 void dm_dirty_log_destroy(struct dm_dirty_log *log)
 176 {
 177         log->type->dtr(log);
 178         put_type(log->type);
 179         kfree(log);
 180 }
 181 EXPORT_SYMBOL(dm_dirty_log_destroy);
 182
 183 /*-----------------------------------------------------------------
 184  * Persistent and core logs share a lot of their implementation.
 185  * FIXME: need a reload method to be called from a resume
 186  *---------------------------------------------------------------*/
 187 /*
 188  * Magic for persistent mirrors: "MiRr"
 189  */
 190 #define MIRROR_MAGIC 0x4D695272
 191
 192 /*
 193  * The on-disk version of the metadata.
 194  */
 195 #define MIRROR_DISK_VERSION 2
 196 #define LOG_OFFSET 2
 197
 198 struct log_header {
 199         uint32_t magic;
 200
 201         /*
 202          * Simple, incrementing version. no backward
 203          * compatibility.
 204          */
 205         uint32_t version;
 206         sector_t nr_regions;
 207 };
 208
 209 struct log_c {
 210         struct dm_target *ti;
 211         int touched;
 212         uint32_t region_size;
 213         unsigned int region_count;
 214         region_t sync_count;
 215
 216         unsigned bitset_uint32_count;
 217         uint32_t *clean_bits;
 218         uint32_t *sync_bits;
 219         uint32_t *recovering_bits;      /* FIXME: this seems excessive */
 220
 221         int sync_search;
 222
 223         /* Resync flag */
 224         enum sync {
 225                 DEFAULTSYNC,    /* Synchronize if necessary */
 226                 NOSYNC,         /* Devices known to be already in sync */
 227                 FORCESYNC,      /* Force a sync to happen */
 228         } sync;
 229
 230         struct dm_io_request io_req;
 231
 232         /*
 233          * Disk log fields
 234          */
 235         int log_dev_failed;
 236         struct dm_dev *log_dev;
 237         struct log_header header;
 238
 239         struct dm_io_region header_location;
 240         struct log_header *disk_header;
 241 };
 242
 243 /*
 244  * The touched member needs to be updated every time we access
 245  * one of the bitsets.
 246  */
 247 static inline int log_test_bit(uint32_t *bs, unsigned bit)
 248 {
 249         return ext2_test_bit(bit, (unsigned long *) bs) ? 1 : 0;
 250 }
 251
 252 static inline void log_set_bit(struct log_c *l,
 253                                uint32_t *bs, unsigned bit)
 254 {
 255         ext2_set_bit(bit, (unsigned long *) bs);
 256         l->touched = 1;
 257 }
 258
 259 static inline void log_clear_bit(struct log_c *l,
 260                                  uint32_t *bs, unsigned bit)
 261 {
 262         ext2_clear_bit(bit, (unsigned long *) bs);
 263         l->touched = 1;
 264 }
 265
 266 /*----------------------------------------------------------------
 267  * Header IO
 268  *--------------------------------------------------------------*/
 269 static void header_to_disk(struct log_header *core, struct log_header *disk)
 270 {
 271         disk->magic = cpu_to_le32(core->magic);
 272         disk->version = cpu_to_le32(core->version);
 273         disk->nr_regions = cpu_to_le64(core->nr_regions);
 274 }
 275
 276 static void header_from_disk(struct log_header *core, struct log_header *disk)
 277 {
 278         core->magic = le32_to_cpu(disk->magic);
 279         core->version = le32_to_cpu(disk->version);
 280         core->nr_regions = le64_to_cpu(disk->nr_regions);
 281 }
 282
 283 static int rw_header(struct log_c *lc, int rw)
 284 {
 285         lc->io_req.bi_rw = rw;
 286
 287         return dm_io(&lc->io_req, 1, &lc->header_location, NULL);
 288 }
 289
 290 static int read_header(struct log_c *log)
 291 {
 292         int r;
 293
 294         r = rw_header(log, READ);
 295         if (r)
 296                 return r;
 297
 298         header_from_disk(&log->header, log->disk_header);
 299
 300         /* New log required? */
 301         if (log->sync != DEFAULTSYNC || log->header.magic != MIRROR_MAGIC) {
 302                 log->header.magic = MIRROR_MAGIC;
 303                 log->header.version = MIRROR_DISK_VERSION;
 304                 log->header.nr_regions = 0;
 305         }
 306
 307 #ifdef __LITTLE_ENDIAN
 308         if (log->header.version == 1)
 309                 log->header.version = 2;
 310 #endif
 311
 312         if (log->header.version != MIRROR_DISK_VERSION) {
 313                 DMWARN("incompatible disk log version");
 314                 return -EINVAL;
 315         }
 316
 317         return 0;
 318 }
 319
 320 static int _check_region_size(struct dm_target *ti, uint32_t region_size)
 321 {
 322         if (region_size < 2 || region_size > ti->len)
 323                 return 0;
 324
 325         if (!is_power_of_2(region_size))
 326                 return 0;
 327
 328         return 1;
 329 }
 330
 331 /*----------------------------------------------------------------
 332  * core log constructor/destructor
 333  *
 334  * argv contains region_size followed optionally by [no]sync
 335  *--------------------------------------------------------------*/
 336 #define BYTE_SHIFT 3
 337 static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti,
 338                               unsigned int argc, char **argv,
 339                               struct dm_dev *dev)
 340 {
 341         enum sync sync = DEFAULTSYNC;
 342
 343         struct log_c *lc;
 344         uint32_t region_size;
 345         unsigned int region_count;
 346         size_t bitset_size, buf_size;
 347         int r;
 348
 349         if (argc < 1 || argc > 2) {
 350                 DMWARN("wrong number of arguments to dirty region log");
 351                 return -EINVAL;
 352         }
 353
 354         if (argc > 1) {
 355                 if (!strcmp(argv[1], "sync"))
 356                         sync = FORCESYNC;
 357                 else if (!strcmp(argv[1], "nosync"))
 358                         sync = NOSYNC;
 359                 else {
 360                         DMWARN("unrecognised sync argument to "
 361                                "dirty region log: %s", argv[1]);
 362                         return -EINVAL;
 363                 }
 364         }
 365
 366         if (sscanf(argv[0], "%u", &region_size) != 1 ||
 367             !_check_region_size(ti, region_size)) {
 368                 DMWARN("invalid region size %s", argv[0]);
 369                 return -EINVAL;
 370         }
 371
 372         region_count = dm_sector_div_up(ti->len, region_size);
 373
 374         lc = kmalloc(sizeof(*lc), GFP_KERNEL);
 375         if (!lc) {
 376                 DMWARN("couldn't allocate core log");
 377                 return -ENOMEM;
 378         }
 379
 380         lc->ti = ti;
 381         lc->touched = 0;
 382         lc->region_size = region_size;
 383         lc->region_count = region_count;
 384         lc->sync = sync;
 385
 386         /*
 387          * Work out how many "unsigned long"s we need to hold the bitset.
 388          */
 389         bitset_size = dm_round_up(region_count,
 390                                   sizeof(*lc->clean_bits) << BYTE_SHIFT);
 391         bitset_size >>= BYTE_SHIFT;
 392
 393         lc->bitset_uint32_count = bitset_size / sizeof(*lc->clean_bits);
 394
 395         /*
 396          * Disk log?
 397          */
 398         if (!dev) {
 399                 lc->clean_bits = vmalloc(bitset_size);
 400                 if (!lc->clean_bits) {
 401                         DMWARN("couldn't allocate clean bitset");
 402                         kfree(lc);
 403                         return -ENOMEM;
 404                 }
 405                 lc->disk_header = NULL;
 406         } else {
 407                 lc->log_dev = dev;
 408                 lc->log_dev_failed = 0;
 409                 lc->header_location.bdev = lc->log_dev->bdev;
 410                 lc->header_location.sector = 0;
 411
 412                 /*
 413                  * Buffer holds both header and bitset.
 414                  */
 415                 buf_size =
 416                     dm_round_up((LOG_OFFSET << SECTOR_SHIFT) + bitset_size,
 417                                 bdev_logical_block_size(lc->header_location.
 418                                                             bdev));
 419
 420                 if (buf_size > i_size_read(dev->bdev->bd_inode)) {
 421                         DMWARN("log device %s too small: need %llu bytes",
 422                                 dev->name, (unsigned long long)buf_size);
 423                         kfree(lc);
 424                         return -EINVAL;
 425                 }
 426
 427                 lc->header_location.count = buf_size >> SECTOR_SHIFT;
 428
 429                 lc->io_req.mem.type = DM_IO_VMA;
 430                 lc->io_req.notify.fn = NULL;
 431                 lc->io_req.client = dm_io_client_create(dm_div_up(buf_size,
 432                                                                    PAGE_SIZE));
 433                 if (IS_ERR(lc->io_req.client)) {
 434                         r = PTR_ERR(lc->io_req.client);
 435                         DMWARN("couldn't allocate disk io client");
 436                         kfree(lc);
 437                         return -ENOMEM;
 438                 }
 439
 440                 lc->disk_header = vmalloc(buf_size);
 441                 if (!lc->disk_header) {
 442                         DMWARN("couldn't allocate disk log buffer");
 443                         dm_io_client_destroy(lc->io_req.client);
 444                         kfree(lc);
 445                         return -ENOMEM;
 446                 }
 447
 448                 lc->io_req.mem.ptr.vma = lc->disk_header;
 449                 lc->clean_bits = (void *)lc->disk_header +
 450                                  (LOG_OFFSET << SECTOR_SHIFT);
 451         }
 452
 453         memset(lc->clean_bits, -1, bitset_size);
 454
 455         lc->sync_bits = vmalloc(bitset_size);
 456         if (!lc->sync_bits) {
 457                 DMWARN("couldn't allocate sync bitset");
 458                 if (!dev)
 459                         vfree(lc->clean_bits);
 460                 else
 461                         dm_io_client_destroy(lc->io_req.client);
 462                 vfree(lc->disk_header);
 463                 kfree(lc);
 464                 return -ENOMEM;
 465         }
 466         memset(lc->sync_bits, (sync == NOSYNC) ? -1 : 0, bitset_size);
 467         lc->sync_count = (sync == NOSYNC) ? region_count : 0;
 468
 469         lc->recovering_bits = vmalloc(bitset_size);
 470         if (!lc->recovering_bits) {
 471                 DMWARN("couldn't allocate sync bitset");
 472                 vfree(lc->sync_bits);
 473                 if (!dev)
 474                         vfree(lc->clean_bits);
 475                 else
 476                         dm_io_client_destroy(lc->io_req.client);
 477                 vfree(lc->disk_header);
 478                 kfree(lc);
 479                 return -ENOMEM;
 480         }
 481         memset(lc->recovering_bits, 0, bitset_size);
 482         lc->sync_search = 0;
 483         log->context = lc;
 484
 485         return 0;
 486 }
 487
 488 static int core_ctr(struct dm_dirty_log *log, struct dm_target *ti,
 489                     unsigned int argc, char **argv)
 490 {
 491         return create_log_context(log, ti, argc, argv, NULL);
 492 }
 493
 494 static void destroy_log_context(struct log_c *lc)
 495 {
 496         vfree(lc->sync_bits);
 497         vfree(lc->recovering_bits);
 498         kfree(lc);
 499 }
 500
 501 static void core_dtr(struct dm_dirty_log *log)
 502 {
 503         struct log_c *lc = (struct log_c *) log->context;
 504
 505         vfree(lc->clean_bits);
 506         destroy_log_context(lc);
 507 }
 508
 509 /*----------------------------------------------------------------
 510  * disk log constructor/destructor
 511  *
 512  * argv contains log_device region_size followed optionally by [no]sync
 513  *--------------------------------------------------------------*/
 514 static int disk_ctr(struct dm_dirty_log *log, struct dm_target *ti,
 515                     unsigned int argc, char **argv)
 516 {
 517         int r;
 518         struct dm_dev *dev;
 519
 520         if (argc < 2 || argc > 3) {
 521                 DMWARN("wrong number of arguments to disk dirty region log");
 522                 return -EINVAL;
 523         }
 524
 525         r = dm_get_device(ti, argv[0], 0, 0 /* FIXME */,
 526                           FMODE_READ | FMODE_WRITE, &dev);
 527         if (r)
 528                 return r;
 529
 530         r = create_log_context(log, ti, argc - 1, argv + 1, dev);
 531         if (r) {
 532                 dm_put_device(ti, dev);
 533                 return r;
 534         }
 535
 536         return 0;
 537 }
 538
 539 static void disk_dtr(struct dm_dirty_log *log)
 540 {
 541         struct log_c *lc = (struct log_c *) log->context;
 542
 543         dm_put_device(lc->ti, lc->log_dev);
 544         vfree(lc->disk_header);
 545         dm_io_client_destroy(lc->io_req.client);
 546         destroy_log_context(lc);
 547 }
 548
 549 static int count_bits32(uint32_t *addr, unsigned size)
 550 {
 551         int count = 0, i;
 552
 553         for (i = 0; i < size; i++) {
 554                 count += hweight32(*(addr+i));
 555         }
 556         return count;
 557 }
 558
 559 static void fail_log_device(struct log_c *lc)
 560 {
 561         if (lc->log_dev_failed)
 562                 return;
 563
 564         lc->log_dev_failed = 1;
 565         dm_table_event(lc->ti->table);
 566 }
 567
 568 static int disk_resume(struct dm_dirty_log *log)
 569 {
 570         int r;
 571         unsigned i;
 572         struct log_c *lc = (struct log_c *) log->context;
 573         size_t size = lc->bitset_uint32_count * sizeof(uint32_t);
 574
 575         /* read the disk header */
 576         r = read_header(lc);
 577         if (r) {
 578                 DMWARN("%s: Failed to read header on dirty region log device",
 579                        lc->log_dev->name);
 580                 fail_log_device(lc);
 581                 /*
 582                  * If the log device cannot be read, we must assume
 583                  * all regions are out-of-sync.  If we simply return
 584                  * here, the state will be uninitialized and could
 585                  * lead us to return 'in-sync' status for regions
 586                  * that are actually 'out-of-sync'.
 587                  */
 588                 lc->header.nr_regions = 0;
 589         }
 590
 591         /* set or clear any new bits -- device has grown */
 592         if (lc->sync == NOSYNC)
 593                 for (i = lc->header.nr_regions; i < lc->region_count; i++)
 594                         /* FIXME: amazingly inefficient */
 595                         log_set_bit(lc, lc->clean_bits, i);
 596         else
 597                 for (i = lc->header.nr_regions; i < lc->region_count; i++)
 598                         /* FIXME: amazingly inefficient */
 599                         log_clear_bit(lc, lc->clean_bits, i);
 600
 601         /* clear any old bits -- device has shrunk */
 602         for (i = lc->region_count; i % (sizeof(*lc->clean_bits) << BYTE_SHIFT); i++)
 603                 log_clear_bit(lc, lc->clean_bits, i);
 604
 605         /* copy clean across to sync */
 606         memcpy(lc->sync_bits, lc->clean_bits, size);
 607         lc->sync_count = count_bits32(lc->clean_bits, lc->bitset_uint32_count);
 608         lc->sync_search = 0;
 609
 610         /* set the correct number of regions in the header */
 611         lc->header.nr_regions = lc->region_count;
 612
 613         header_to_disk(&lc->header, lc->disk_header);
 614
 615         /* write the new header */
 616         r = rw_header(lc, WRITE);
 617         if (r) {
 618                 DMWARN("%s: Failed to write header on dirty region log device",
 619                        lc->log_dev->name);
 620                 fail_log_device(lc);
 621         }
 622
 623         return r;
 624 }
 625
 626 static uint32_t core_get_region_size(struct dm_dirty_log *log)
 627 {
 628         struct log_c *lc = (struct log_c *) log->context;
 629         return lc->region_size;
 630 }
 631
 632 static int core_resume(struct dm_dirty_log *log)
 633 {
 634         struct log_c *lc = (struct log_c *) log->context;
 635         lc->sync_search = 0;
 636         return 0;
 637 }
 638
 639 static int core_is_clean(struct dm_dirty_log *log, region_t region)
 640 {
 641         struct log_c *lc = (struct log_c *) log->context;
 642         return log_test_bit(lc->clean_bits, region);
 643 }
 644
 645 static int core_in_sync(struct dm_dirty_log *log, region_t region, int block)
 646 {
 647         struct log_c *lc = (struct log_c *) log->context;
 648         return log_test_bit(lc->sync_bits, region);
 649 }
 650
 651 static int core_flush(struct dm_dirty_log *log)
 652 {
 653         /* no op */
 654         return 0;
 655 }
 656
 657 static int disk_flush(struct dm_dirty_log *log)
 658 {
 659         int r;
 660         struct log_c *lc = (struct log_c *) log->context;
 661
 662         /* only write if the log has changed */
 663         if (!lc->touched)
 664                 return 0;
 665
 666         r = rw_header(lc, WRITE);
 667         if (r)
 668                 fail_log_device(lc);
 669         else
 670                 lc->touched = 0;
 671
 672         return r;
 673 }
 674
 675 static void core_mark_region(struct dm_dirty_log *log, region_t region)
 676 {
 677         struct log_c *lc = (struct log_c *) log->context;
 678         log_clear_bit(lc, lc->clean_bits, region);
 679 }
 680
 681 static void core_clear_region(struct dm_dirty_log *log, region_t region)
 682 {
 683         struct log_c *lc = (struct log_c *) log->context;
 684         log_set_bit(lc, lc->clean_bits, region);
 685 }
 686
 687 static int core_get_resync_work(struct dm_dirty_log *log, region_t *region)
 688 {
 689         struct log_c *lc = (struct log_c *) log->context;
 690
 691         if (lc->sync_search >= lc->region_count)
 692                 return 0;
 693
 694         do {
 695                 *region = ext2_find_next_zero_bit(
 696                                              (unsigned long *) lc->sync_bits,
 697                                              lc->region_count,
 698                                              lc->sync_search);
 699                 lc->sync_search = *region + 1;
 700
 701                 if (*region >= lc->region_count)
 702                         return 0;
 703
 704         } while (log_test_bit(lc->recovering_bits, *region));
 705
 706         log_set_bit(lc, lc->recovering_bits, *region);
 707         return 1;
 708 }
 709
 710 static void core_set_region_sync(struct dm_dirty_log *log, region_t region,
 711                                  int in_sync)
 712 {
 713         struct log_c *lc = (struct log_c *) log->context;
 714
 715         log_clear_bit(lc, lc->recovering_bits, region);
 716         if (in_sync) {
 717                 log_set_bit(lc, lc->sync_bits, region);
 718                 lc->sync_count++;
 719         } else if (log_test_bit(lc->sync_bits, region)) {
 720                 lc->sync_count--;
 721                 log_clear_bit(lc, lc->sync_bits, region);
 722         }
 723 }
 724
 725 static region_t core_get_sync_count(struct dm_dirty_log *log)
 726 {
 727         struct log_c *lc = (struct log_c *) log->context;
 728
 729         return lc->sync_count;
 730 }
 731
 732 #define DMEMIT_SYNC \
 733         if (lc->sync != DEFAULTSYNC) \
 734                 DMEMIT("%ssync ", lc->sync == NOSYNC ? "no" : "")
 735
 736 static int core_status(struct dm_dirty_log *log, status_type_t status,
 737                        char *result, unsigned int maxlen)
 738 {
 739         int sz = 0;
 740         struct log_c *lc = log->context;
 741
 742         switch(status) {
 743         case STATUSTYPE_INFO:
 744                 DMEMIT("1 %s", log->type->name);
 745                 break;
 746
 747         case STATUSTYPE_TABLE:
 748                 DMEMIT("%s %u %u ", log->type->name,
 749                        lc->sync == DEFAULTSYNC ? 1 : 2, lc->region_size);
 750                 DMEMIT_SYNC;
 751         }
 752
 753         return sz;
 754 }
 755
 756 static int disk_status(struct dm_dirty_log *log, status_type_t status,
 757                        char *result, unsigned int maxlen)
 758 {
 759         int sz = 0;
 760         struct log_c *lc = log->context;
 761
 762         switch(status) {
 763         case STATUSTYPE_INFO:
 764                 DMEMIT("3 %s %s %c", log->type->name, lc->log_dev->name,
 765                        lc->log_dev_failed ? 'D' : 'A');
 766                 break;
 767
 768         case STATUSTYPE_TABLE:
 769                 DMEMIT("%s %u %s %u ", log->type->name,
 770                        lc->sync == DEFAULTSYNC ? 2 : 3, lc->log_dev->name,
 771                        lc->region_size);
 772                 DMEMIT_SYNC;
 773         }
 774
 775         return sz;
 776 }
 777
 778 static struct dm_dirty_log_type _core_type = {
 779         .name = "core",
 780         .module = THIS_MODULE,
 781         .ctr = core_ctr,
 782         .dtr = core_dtr,
 783         .resume = core_resume,
 784         .get_region_size = core_get_region_size,
 785         .is_clean = core_is_clean,
 786         .in_sync = core_in_sync,
 787         .flush = core_flush,
 788         .mark_region = core_mark_region,
 789         .clear_region = core_clear_region,
 790         .get_resync_work = core_get_resync_work,
 791         .set_region_sync = core_set_region_sync,
 792         .get_sync_count = core_get_sync_count,
 793         .status = core_status,
 794 };
 795
 796 static struct dm_dirty_log_type _disk_type = {
 797         .name = "disk",
 798         .module = THIS_MODULE,
 799         .ctr = disk_ctr,
 800         .dtr = disk_dtr,
 801         .postsuspend = disk_flush,
 802         .resume = disk_resume,
 803         .get_region_size = core_get_region_size,
 804         .is_clean = core_is_clean,
 805         .in_sync = core_in_sync,
 806         .flush = disk_flush,
 807         .mark_region = core_mark_region,
 808         .clear_region = core_clear_region,
 809         .get_resync_work = core_get_resync_work,
 810         .set_region_sync = core_set_region_sync,
 811         .get_sync_count = core_get_sync_count,
 812         .status = disk_status,
 813 };
 814
 815 static int __init dm_dirty_log_init(void)
 816 {
 817         int r;
 818
 819         r = dm_dirty_log_type_register(&_core_type);
 820         if (r)
 821                 DMWARN("couldn't register core log");
 822
 823         r = dm_dirty_log_type_register(&_disk_type);
 824         if (r) {
 825                 DMWARN("couldn't register disk type");
 826                 dm_dirty_log_type_unregister(&_core_type);
 827         }
 828
 829         return r;
 830 }
 831
 832 static void __exit dm_dirty_log_exit(void)
 833 {
 834         dm_dirty_log_type_unregister(&_disk_type);
 835         dm_dirty_log_type_unregister(&_core_type);
 836 }
 837
 838 module_init(dm_dirty_log_init);
 839 module_exit(dm_dirty_log_exit);
 840
 841 MODULE_DESCRIPTION(DM_NAME " dirty region log");
 842 MODULE_AUTHOR("Joe Thornber, Heinz Mauelshagen <dm-devel@redhat.com>");
 843 MODULE_LICENSE("GPL");