release/src-rt-6.x.4708/linux/linux-2.6.36/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  * Magic for persistent mirrors: "MiRr"
 187  */
 188 #define MIRROR_MAGIC 0x4D695272
 189
 190 /*
 191  * The on-disk version of the metadata.
 192  */
 193 #define MIRROR_DISK_VERSION 2
 194 #define LOG_OFFSET 2
 195
 196 struct log_header {
 197         uint32_t magic;
 198
 199         /*
 200          * Simple, incrementing version. no backward
 201          * compatibility.
 202          */
 203         uint32_t version;
 204         sector_t nr_regions;
 205 };
 206
 207 struct log_c {
 208         struct dm_target *ti;
 209         int touched_dirtied;
 210         int touched_cleaned;
 211         int flush_failed;
 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;
 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         int log_dev_flush_failed;
 237         struct dm_dev *log_dev;
 238         struct log_header header;
 239
 240         struct dm_io_region header_location;
 241         struct log_header *disk_header;
 242 };
 243
 244 /*
 245  * The touched member needs to be updated every time we access
 246  * one of the bitsets.
 247  */
 248 static inline int log_test_bit(uint32_t *bs, unsigned bit)
 249 {
 250         return ext2_test_bit(bit, (unsigned long *) bs) ? 1 : 0;
 251 }
 252
 253 static inline void log_set_bit(struct log_c *l,
 254                                uint32_t *bs, unsigned bit)
 255 {
 256         ext2_set_bit(bit, (unsigned long *) bs);
 257         l->touched_cleaned = 1;
 258 }
 259
 260 static inline void log_clear_bit(struct log_c *l,
 261                                  uint32_t *bs, unsigned bit)
 262 {
 263         ext2_clear_bit(bit, (unsigned long *) bs);
 264         l->touched_dirtied = 1;
 265 }
 266
 267 /*----------------------------------------------------------------
 268  * Header IO
 269  *--------------------------------------------------------------*/
 270 static void header_to_disk(struct log_header *core, struct log_header *disk)
 271 {
 272         disk->magic = cpu_to_le32(core->magic);
 273         disk->version = cpu_to_le32(core->version);
 274         disk->nr_regions = cpu_to_le64(core->nr_regions);
 275 }
 276
 277 static void header_from_disk(struct log_header *core, struct log_header *disk)
 278 {
 279         core->magic = le32_to_cpu(disk->magic);
 280         core->version = le32_to_cpu(disk->version);
 281         core->nr_regions = le64_to_cpu(disk->nr_regions);
 282 }
 283
 284 static int rw_header(struct log_c *lc, int rw)
 285 {
 286         lc->io_req.bi_rw = rw;
 287
 288         return dm_io(&lc->io_req, 1, &lc->header_location, NULL);
 289 }
 290
 291 static int flush_header(struct log_c *lc)
 292 {
 293         struct dm_io_region null_location = {
 294                 .bdev = lc->header_location.bdev,
 295                 .sector = 0,
 296                 .count = 0,
 297         };
 298
 299         lc->io_req.bi_rw = WRITE_BARRIER;
 300
 301         return dm_io(&lc->io_req, 1, &null_location, NULL);
 302 }
 303
 304 static int read_header(struct log_c *log)
 305 {
 306         int r;
 307
 308         r = rw_header(log, READ);
 309         if (r)
 310                 return r;
 311
 312         header_from_disk(&log->header, log->disk_header);
 313
 314         /* New log required? */
 315         if (log->sync != DEFAULTSYNC || log->header.magic != MIRROR_MAGIC) {
 316                 log->header.magic = MIRROR_MAGIC;
 317                 log->header.version = MIRROR_DISK_VERSION;
 318                 log->header.nr_regions = 0;
 319         }
 320
 321 #ifdef __LITTLE_ENDIAN
 322         if (log->header.version == 1)
 323                 log->header.version = 2;
 324 #endif
 325
 326         if (log->header.version != MIRROR_DISK_VERSION) {
 327                 DMWARN("incompatible disk log version");
 328                 return -EINVAL;
 329         }
 330
 331         return 0;
 332 }
 333
 334 static int _check_region_size(struct dm_target *ti, uint32_t region_size)
 335 {
 336         if (region_size < 2 || region_size > ti->len)
 337                 return 0;
 338
 339         if (!is_power_of_2(region_size))
 340                 return 0;
 341
 342         return 1;
 343 }
 344
 345 /*----------------------------------------------------------------
 346  * core log constructor/destructor
 347  *
 348  * argv contains region_size followed optionally by [no]sync
 349  *--------------------------------------------------------------*/
 350 #define BYTE_SHIFT 3
 351 static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti,
 352                               unsigned int argc, char **argv,
 353                               struct dm_dev *dev)
 354 {
 355         enum sync sync = DEFAULTSYNC;
 356
 357         struct log_c *lc;
 358         uint32_t region_size;
 359         unsigned int region_count;
 360         size_t bitset_size, buf_size;
 361         int r;
 362
 363         if (argc < 1 || argc > 2) {
 364                 DMWARN("wrong number of arguments to dirty region log");
 365                 return -EINVAL;
 366         }
 367
 368         if (argc > 1) {
 369                 if (!strcmp(argv[1], "sync"))
 370                         sync = FORCESYNC;
 371                 else if (!strcmp(argv[1], "nosync"))
 372                         sync = NOSYNC;
 373                 else {
 374                         DMWARN("unrecognised sync argument to "
 375                                "dirty region log: %s", argv[1]);
 376                         return -EINVAL;
 377                 }
 378         }
 379
 380         if (sscanf(argv[0], "%u", &region_size) != 1 ||
 381             !_check_region_size(ti, region_size)) {
 382                 DMWARN("invalid region size %s", argv[0]);
 383                 return -EINVAL;
 384         }
 385
 386         region_count = dm_sector_div_up(ti->len, region_size);
 387
 388         lc = kmalloc(sizeof(*lc), GFP_KERNEL);
 389         if (!lc) {
 390                 DMWARN("couldn't allocate core log");
 391                 return -ENOMEM;
 392         }
 393
 394         lc->ti = ti;
 395         lc->touched_dirtied = 0;
 396         lc->touched_cleaned = 0;
 397         lc->flush_failed = 0;
 398         lc->region_size = region_size;
 399         lc->region_count = region_count;
 400         lc->sync = sync;
 401
 402         /*
 403          * Work out how many "unsigned long"s we need to hold the bitset.
 404          */
 405         bitset_size = dm_round_up(region_count,
 406                                   sizeof(*lc->clean_bits) << BYTE_SHIFT);
 407         bitset_size >>= BYTE_SHIFT;
 408
 409         lc->bitset_uint32_count = bitset_size / sizeof(*lc->clean_bits);
 410
 411         /*
 412          * Disk log?
 413          */
 414         if (!dev) {
 415                 lc->clean_bits = vmalloc(bitset_size);
 416                 if (!lc->clean_bits) {
 417                         DMWARN("couldn't allocate clean bitset");
 418                         kfree(lc);
 419                         return -ENOMEM;
 420                 }
 421                 lc->disk_header = NULL;
 422         } else {
 423                 lc->log_dev = dev;
 424                 lc->log_dev_failed = 0;
 425                 lc->log_dev_flush_failed = 0;
 426                 lc->header_location.bdev = lc->log_dev->bdev;
 427                 lc->header_location.sector = 0;
 428
 429                 /*
 430                  * Buffer holds both header and bitset.
 431                  */
 432                 buf_size =
 433                     dm_round_up((LOG_OFFSET << SECTOR_SHIFT) + bitset_size,
 434                                 bdev_logical_block_size(lc->header_location.
 435                                                             bdev));
 436
 437                 if (buf_size > i_size_read(dev->bdev->bd_inode)) {
 438                         DMWARN("log device %s too small: need %llu bytes",
 439                                 dev->name, (unsigned long long)buf_size);
 440                         kfree(lc);
 441                         return -EINVAL;
 442                 }
 443
 444                 lc->header_location.count = buf_size >> SECTOR_SHIFT;
 445
 446                 lc->io_req.mem.type = DM_IO_VMA;
 447                 lc->io_req.notify.fn = NULL;
 448                 lc->io_req.client = dm_io_client_create(dm_div_up(buf_size,
 449                                                                    PAGE_SIZE));
 450                 if (IS_ERR(lc->io_req.client)) {
 451                         r = PTR_ERR(lc->io_req.client);
 452                         DMWARN("couldn't allocate disk io client");
 453                         kfree(lc);
 454                         return -ENOMEM;
 455                 }
 456
 457                 lc->disk_header = vmalloc(buf_size);
 458                 if (!lc->disk_header) {
 459                         DMWARN("couldn't allocate disk log buffer");
 460                         dm_io_client_destroy(lc->io_req.client);
 461                         kfree(lc);
 462                         return -ENOMEM;
 463                 }
 464
 465                 lc->io_req.mem.ptr.vma = lc->disk_header;
 466                 lc->clean_bits = (void *)lc->disk_header +
 467                                  (LOG_OFFSET << SECTOR_SHIFT);
 468         }
 469
 470         memset(lc->clean_bits, -1, bitset_size);
 471
 472         lc->sync_bits = vmalloc(bitset_size);
 473         if (!lc->sync_bits) {
 474                 DMWARN("couldn't allocate sync bitset");
 475                 if (!dev)
 476                         vfree(lc->clean_bits);
 477                 else
 478                         dm_io_client_destroy(lc->io_req.client);
 479                 vfree(lc->disk_header);
 480                 kfree(lc);
 481                 return -ENOMEM;
 482         }
 483         memset(lc->sync_bits, (sync == NOSYNC) ? -1 : 0, bitset_size);
 484         lc->sync_count = (sync == NOSYNC) ? region_count : 0;
 485
 486         lc->recovering_bits = vmalloc(bitset_size);
 487         if (!lc->recovering_bits) {
 488                 DMWARN("couldn't allocate sync bitset");
 489                 vfree(lc->sync_bits);
 490                 if (!dev)
 491                         vfree(lc->clean_bits);
 492                 else
 493                         dm_io_client_destroy(lc->io_req.client);
 494                 vfree(lc->disk_header);
 495                 kfree(lc);
 496                 return -ENOMEM;
 497         }
 498         memset(lc->recovering_bits, 0, bitset_size);
 499         lc->sync_search = 0;
 500         log->context = lc;
 501
 502         return 0;
 503 }
 504
 505 static int core_ctr(struct dm_dirty_log *log, struct dm_target *ti,
 506                     unsigned int argc, char **argv)
 507 {
 508         return create_log_context(log, ti, argc, argv, NULL);
 509 }
 510
 511 static void destroy_log_context(struct log_c *lc)
 512 {
 513         vfree(lc->sync_bits);
 514         vfree(lc->recovering_bits);
 515         kfree(lc);
 516 }
 517
 518 static void core_dtr(struct dm_dirty_log *log)
 519 {
 520         struct log_c *lc = (struct log_c *) log->context;
 521
 522         vfree(lc->clean_bits);
 523         destroy_log_context(lc);
 524 }
 525
 526 /*----------------------------------------------------------------
 527  * disk log constructor/destructor
 528  *
 529  * argv contains log_device region_size followed optionally by [no]sync
 530  *--------------------------------------------------------------*/
 531 static int disk_ctr(struct dm_dirty_log *log, struct dm_target *ti,
 532                     unsigned int argc, char **argv)
 533 {
 534         int r;
 535         struct dm_dev *dev;
 536
 537         if (argc < 2 || argc > 3) {
 538                 DMWARN("wrong number of arguments to disk dirty region log");
 539                 return -EINVAL;
 540         }
 541
 542         r = dm_get_device(ti, argv[0], FMODE_READ | FMODE_WRITE, &dev);
 543         if (r)
 544                 return r;
 545
 546         r = create_log_context(log, ti, argc - 1, argv + 1, dev);
 547         if (r) {
 548                 dm_put_device(ti, dev);
 549                 return r;
 550         }
 551
 552         return 0;
 553 }
 554
 555 static void disk_dtr(struct dm_dirty_log *log)
 556 {
 557         struct log_c *lc = (struct log_c *) log->context;
 558
 559         dm_put_device(lc->ti, lc->log_dev);
 560         vfree(lc->disk_header);
 561         dm_io_client_destroy(lc->io_req.client);
 562         destroy_log_context(lc);
 563 }
 564
 565 static int count_bits32(uint32_t *addr, unsigned size)
 566 {
 567         int count = 0, i;
 568
 569         for (i = 0; i < size; i++) {
 570                 count += hweight32(*(addr+i));
 571         }
 572         return count;
 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                         log_set_bit(lc, lc->clean_bits, i);
 611         else
 612                 for (i = lc->header.nr_regions; i < lc->region_count; i++)
 613                         log_clear_bit(lc, lc->clean_bits, i);
 614
 615         /* clear any old bits -- device has shrunk */
 616         for (i = lc->region_count; i % (sizeof(*lc->clean_bits) << BYTE_SHIFT); i++)
 617                 log_clear_bit(lc, lc->clean_bits, i);
 618
 619         /* copy clean across to sync */
 620         memcpy(lc->sync_bits, lc->clean_bits, size);
 621         lc->sync_count = count_bits32(lc->clean_bits, lc->bitset_uint32_count);
 622         lc->sync_search = 0;
 623
 624         /* set the correct number of regions in the header */
 625         lc->header.nr_regions = lc->region_count;
 626
 627         header_to_disk(&lc->header, lc->disk_header);
 628
 629         /* write the new header */
 630         r = rw_header(lc, WRITE);
 631         if (!r) {
 632                 r = flush_header(lc);
 633                 if (r)
 634                         lc->log_dev_flush_failed = 1;
 635         }
 636         if (r) {
 637                 DMWARN("%s: Failed to write header on dirty region log device",
 638                        lc->log_dev->name);
 639                 fail_log_device(lc);
 640         }
 641
 642         return r;
 643 }
 644
 645 static uint32_t core_get_region_size(struct dm_dirty_log *log)
 646 {
 647         struct log_c *lc = (struct log_c *) log->context;
 648         return lc->region_size;
 649 }
 650
 651 static int core_resume(struct dm_dirty_log *log)
 652 {
 653         struct log_c *lc = (struct log_c *) log->context;
 654         lc->sync_search = 0;
 655         return 0;
 656 }
 657
 658 static int core_is_clean(struct dm_dirty_log *log, region_t region)
 659 {
 660         struct log_c *lc = (struct log_c *) log->context;
 661         return log_test_bit(lc->clean_bits, region);
 662 }
 663
 664 static int core_in_sync(struct dm_dirty_log *log, region_t region, int block)
 665 {
 666         struct log_c *lc = (struct log_c *) log->context;
 667         return log_test_bit(lc->sync_bits, region);
 668 }
 669
 670 static int core_flush(struct dm_dirty_log *log)
 671 {
 672         /* no op */
 673         return 0;
 674 }
 675
 676 static int disk_flush(struct dm_dirty_log *log)
 677 {
 678         int r, i;
 679         struct log_c *lc = log->context;
 680
 681         /* only write if the log has changed */
 682         if (!lc->touched_cleaned && !lc->touched_dirtied)
 683                 return 0;
 684
 685         if (lc->touched_cleaned && log->flush_callback_fn &&
 686             log->flush_callback_fn(lc->ti)) {
 687                 /*
 688                  * At this point it is impossible to determine which
 689                  * regions are clean and which are dirty (without
 690                  * re-reading the log off disk). So mark all of them
 691                  * dirty.
 692                  */
 693                 lc->flush_failed = 1;
 694                 for (i = 0; i < lc->region_count; i++)
 695                         log_clear_bit(lc, lc->clean_bits, i);
 696         }
 697
 698         r = rw_header(lc, WRITE);
 699         if (r)
 700                 fail_log_device(lc);
 701         else {
 702                 if (lc->touched_dirtied) {
 703                         r = flush_header(lc);
 704                         if (r) {
 705                                 lc->log_dev_flush_failed = 1;
 706                                 fail_log_device(lc);
 707                         } else
 708                                 lc->touched_dirtied = 0;
 709                 }
 710                 lc->touched_cleaned = 0;
 711         }
 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         if (likely(!lc->flush_failed))
 726                 log_set_bit(lc, lc->clean_bits, region);
 727 }
 728
 729 static int core_get_resync_work(struct dm_dirty_log *log, region_t *region)
 730 {
 731         struct log_c *lc = (struct log_c *) log->context;
 732
 733         if (lc->sync_search >= lc->region_count)
 734                 return 0;
 735
 736         do {
 737                 *region = ext2_find_next_zero_bit(
 738                                              (unsigned long *) lc->sync_bits,
 739                                              lc->region_count,
 740                                              lc->sync_search);
 741                 lc->sync_search = *region + 1;
 742
 743                 if (*region >= lc->region_count)
 744                         return 0;
 745
 746         } while (log_test_bit(lc->recovering_bits, *region));
 747
 748         log_set_bit(lc, lc->recovering_bits, *region);
 749         return 1;
 750 }
 751
 752 static void core_set_region_sync(struct dm_dirty_log *log, region_t region,
 753                                  int in_sync)
 754 {
 755         struct log_c *lc = (struct log_c *) log->context;
 756
 757         log_clear_bit(lc, lc->recovering_bits, region);
 758         if (in_sync) {
 759                 log_set_bit(lc, lc->sync_bits, region);
 760                 lc->sync_count++;
 761         } else if (log_test_bit(lc->sync_bits, region)) {
 762                 lc->sync_count--;
 763                 log_clear_bit(lc, lc->sync_bits, region);
 764         }
 765 }
 766
 767 static region_t core_get_sync_count(struct dm_dirty_log *log)
 768 {
 769         struct log_c *lc = (struct log_c *) log->context;
 770
 771         return lc->sync_count;
 772 }
 773
 774 #define DMEMIT_SYNC \
 775         if (lc->sync != DEFAULTSYNC) \
 776                 DMEMIT("%ssync ", lc->sync == NOSYNC ? "no" : "")
 777
 778 static int core_status(struct dm_dirty_log *log, status_type_t status,
 779                        char *result, unsigned int maxlen)
 780 {
 781         int sz = 0;
 782         struct log_c *lc = log->context;
 783
 784         switch(status) {
 785         case STATUSTYPE_INFO:
 786                 DMEMIT("1 %s", log->type->name);
 787                 break;
 788
 789         case STATUSTYPE_TABLE:
 790                 DMEMIT("%s %u %u ", log->type->name,
 791                        lc->sync == DEFAULTSYNC ? 1 : 2, lc->region_size);
 792                 DMEMIT_SYNC;
 793         }
 794
 795         return sz;
 796 }
 797
 798 static int disk_status(struct dm_dirty_log *log, status_type_t status,
 799                        char *result, unsigned int maxlen)
 800 {
 801         int sz = 0;
 802         struct log_c *lc = log->context;
 803
 804         switch(status) {
 805         case STATUSTYPE_INFO:
 806                 DMEMIT("3 %s %s %c", log->type->name, lc->log_dev->name,
 807                        lc->log_dev_flush_failed ? 'F' :
 808                        lc->log_dev_failed ? 'D' :
 809                        'A');
 810                 break;
 811
 812         case STATUSTYPE_TABLE:
 813                 DMEMIT("%s %u %s %u ", log->type->name,
 814                        lc->sync == DEFAULTSYNC ? 2 : 3, lc->log_dev->name,
 815                        lc->region_size);
 816                 DMEMIT_SYNC;
 817         }
 818
 819         return sz;
 820 }
 821
 822 static struct dm_dirty_log_type _core_type = {
 823         .name = "core",
 824         .module = THIS_MODULE,
 825         .ctr = core_ctr,
 826         .dtr = core_dtr,
 827         .resume = core_resume,
 828         .get_region_size = core_get_region_size,
 829         .is_clean = core_is_clean,
 830         .in_sync = core_in_sync,
 831         .flush = core_flush,
 832         .mark_region = core_mark_region,
 833         .clear_region = core_clear_region,
 834         .get_resync_work = core_get_resync_work,
 835         .set_region_sync = core_set_region_sync,
 836         .get_sync_count = core_get_sync_count,
 837         .status = core_status,
 838 };
 839
 840 static struct dm_dirty_log_type _disk_type = {
 841         .name = "disk",
 842         .module = THIS_MODULE,
 843         .ctr = disk_ctr,
 844         .dtr = disk_dtr,
 845         .postsuspend = disk_flush,
 846         .resume = disk_resume,
 847         .get_region_size = core_get_region_size,
 848         .is_clean = core_is_clean,
 849         .in_sync = core_in_sync,
 850         .flush = disk_flush,
 851         .mark_region = core_mark_region,
 852         .clear_region = core_clear_region,
 853         .get_resync_work = core_get_resync_work,
 854         .set_region_sync = core_set_region_sync,
 855         .get_sync_count = core_get_sync_count,
 856         .status = disk_status,
 857 };
 858
 859 static int __init dm_dirty_log_init(void)
 860 {
 861         int r;
 862
 863         r = dm_dirty_log_type_register(&_core_type);
 864         if (r)
 865                 DMWARN("couldn't register core log");
 866
 867         r = dm_dirty_log_type_register(&_disk_type);
 868         if (r) {
 869                 DMWARN("couldn't register disk type");
 870                 dm_dirty_log_type_unregister(&_core_type);
 871         }
 872
 873         return r;
 874 }
 875
 876 static void __exit dm_dirty_log_exit(void)
 877 {
 878         dm_dirty_log_type_unregister(&_disk_type);
 879         dm_dirty_log_type_unregister(&_core_type);
 880 }
 881
 882 module_init(dm_dirty_log_init);
 883 module_exit(dm_dirty_log_exit);
 884
 885 MODULE_DESCRIPTION(DM_NAME " dirty region log");
 886 MODULE_AUTHOR("Joe Thornber, Heinz Mauelshagen <dm-devel@redhat.com>");
 887 MODULE_LICENSE("GPL");