drivers/md/dm-log.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2003 Sistina Software
   4  * Copyright (C) 2004-2008 Red Hat, Inc. All rights reserved.
   5  *
   6  * This file is released under the LGPL.
   7  */
   8
   9 #include <linux/init.h>
  10 #include <linux/slab.h>
  11 #include <linux/module.h>
  12 #include <linux/vmalloc.h>
  13 #include <linux/dm-io.h>
  14 #include <linux/dm-dirty-log.h>
  15
  16 #include <linux/device-mapper.h>
  17
  18 #define DM_MSG_PREFIX "dirty region log"
  19
  20 static LIST_HEAD(_log_types);
  21 static DEFINE_SPINLOCK(_lock);
  22
  23 static struct dm_dirty_log_type *__find_dirty_log_type(const char *name)
  24 {
  25         struct dm_dirty_log_type *log_type;
  26
  27         list_for_each_entry(log_type, &_log_types, list)
  28                 if (!strcmp(name, log_type->name))
  29                         return log_type;
  30
  31         return NULL;
  32 }
  33
  34 static struct dm_dirty_log_type *_get_dirty_log_type(const char *name)
  35 {
  36         struct dm_dirty_log_type *log_type;
  37
  38         spin_lock(&_lock);
  39
  40         log_type = __find_dirty_log_type(name);
  41         if (log_type && !try_module_get(log_type->module))
  42                 log_type = NULL;
  43
  44         spin_unlock(&_lock);
  45
  46         return log_type;
  47 }
  48
  49 /*
  50  * get_type
  51  * @type_name
  52  *
  53  * Attempt to retrieve the dm_dirty_log_type by name.  If not already
  54  * available, attempt to load the appropriate module.
  55  *
  56  * Log modules are named "dm-log-" followed by the 'type_name'.
  57  * Modules may contain multiple types.
  58  * This function will first try the module "dm-log-<type_name>",
  59  * then truncate 'type_name' on the last '-' and try again.
  60  *
  61  * For example, if type_name was "clustered-disk", it would search
  62  * 'dm-log-clustered-disk' then 'dm-log-clustered'.
  63  *
  64  * Returns: dirty_log_type* on success, NULL on failure
  65  */
  66 static struct dm_dirty_log_type *get_type(const char *type_name)
  67 {
  68         char *p, *type_name_dup;
  69         struct dm_dirty_log_type *log_type;
  70
  71         if (!type_name)
  72                 return NULL;
  73
  74         log_type = _get_dirty_log_type(type_name);
  75         if (log_type)
  76                 return log_type;
  77
  78         type_name_dup = kstrdup(type_name, GFP_KERNEL);
  79         if (!type_name_dup) {
  80                 DMWARN("No memory left to attempt log module load for \"%s\"",
  81                        type_name);
  82                 return NULL;
  83         }
  84
  85         while (request_module("dm-log-%s", type_name_dup) ||
  86                !(log_type = _get_dirty_log_type(type_name))) {
  87                 p = strrchr(type_name_dup, '-');
  88                 if (!p)
  89                         break;
  90                 p[0] = '\0';
  91         }
  92
  93         if (!log_type)
  94                 DMWARN("Module for logging type \"%s\" not found.", type_name);
  95
  96         kfree(type_name_dup);
  97
  98         return log_type;
  99 }
 100
 101 static void put_type(struct dm_dirty_log_type *type)
 102 {
 103         if (!type)
 104                 return;
 105
 106         spin_lock(&_lock);
 107         if (!__find_dirty_log_type(type->name))
 108                 goto out;
 109
 110         module_put(type->module);
 111
 112 out:
 113         spin_unlock(&_lock);
 114 }
 115
 116 int dm_dirty_log_type_register(struct dm_dirty_log_type *type)
 117 {
 118         int r = 0;
 119
 120         spin_lock(&_lock);
 121         if (!__find_dirty_log_type(type->name))
 122                 list_add(&type->list, &_log_types);
 123         else
 124                 r = -EEXIST;
 125         spin_unlock(&_lock);
 126
 127         return r;
 128 }
 129 EXPORT_SYMBOL(dm_dirty_log_type_register);
 130
 131 int dm_dirty_log_type_unregister(struct dm_dirty_log_type *type)
 132 {
 133         spin_lock(&_lock);
 134
 135         if (!__find_dirty_log_type(type->name)) {
 136                 spin_unlock(&_lock);
 137                 return -EINVAL;
 138         }
 139
 140         list_del(&type->list);
 141
 142         spin_unlock(&_lock);
 143
 144         return 0;
 145 }
 146 EXPORT_SYMBOL(dm_dirty_log_type_unregister);
 147
 148 struct dm_dirty_log *dm_dirty_log_create(const char *type_name,
 149                         struct dm_target *ti,
 150                         int (*flush_callback_fn)(struct dm_target *ti),
 151                         unsigned int argc, char **argv)
 152 {
 153         struct dm_dirty_log_type *type;
 154         struct dm_dirty_log *log;
 155
 156         log = kmalloc(sizeof(*log), GFP_KERNEL);
 157         if (!log)
 158                 return NULL;
 159
 160         type = get_type(type_name);
 161         if (!type) {
 162                 kfree(log);
 163                 return NULL;
 164         }
 165
 166         log->flush_callback_fn = flush_callback_fn;
 167         log->type = type;
 168         if (type->ctr(log, ti, argc, argv)) {
 169                 kfree(log);
 170                 put_type(type);
 171                 return NULL;
 172         }
 173
 174         return log;
 175 }
 176 EXPORT_SYMBOL(dm_dirty_log_create);
 177
 178 void dm_dirty_log_destroy(struct dm_dirty_log *log)
 179 {
 180         log->type->dtr(log);
 181         put_type(log->type);
 182         kfree(log);
 183 }
 184 EXPORT_SYMBOL(dm_dirty_log_destroy);
 185
 186 /*
 187  *---------------------------------------------------------------
 188  * Persistent and core logs share a lot of their implementation.
 189  * FIXME: need a reload method to be called from a resume
 190  *---------------------------------------------------------------
 191  */
 192 /*
 193  * Magic for persistent mirrors: "MiRr"
 194  */
 195 #define MIRROR_MAGIC 0x4D695272
 196
 197 /*
 198  * The on-disk version of the metadata.
 199  */
 200 #define MIRROR_DISK_VERSION 2
 201 #define LOG_OFFSET 2
 202
 203 struct log_header_disk {
 204         __le32 magic;
 205
 206         /*
 207          * Simple, incrementing version. no backward
 208          * compatibility.
 209          */
 210         __le32 version;
 211         __le64 nr_regions;
 212 } __packed;
 213
 214 struct log_header_core {
 215         uint32_t magic;
 216         uint32_t version;
 217         uint64_t nr_regions;
 218 };
 219
 220 struct log_c {
 221         struct dm_target *ti;
 222         int touched_dirtied;
 223         int touched_cleaned;
 224         int flush_failed;
 225         uint32_t region_size;
 226         unsigned int region_count;
 227         region_t sync_count;
 228
 229         unsigned int bitset_uint32_count;
 230         uint32_t *clean_bits;
 231         uint32_t *sync_bits;
 232         uint32_t *recovering_bits;      /* FIXME: this seems excessive */
 233
 234         int sync_search;
 235
 236         /* Resync flag */
 237         enum sync {
 238                 DEFAULTSYNC,    /* Synchronize if necessary */
 239                 NOSYNC,         /* Devices known to be already in sync */
 240                 FORCESYNC,      /* Force a sync to happen */
 241         } sync;
 242
 243         struct dm_io_request io_req;
 244
 245         /*
 246          * Disk log fields
 247          */
 248         int log_dev_failed;
 249         int log_dev_flush_failed;
 250         struct dm_dev *log_dev;
 251         struct log_header_core header;
 252
 253         struct dm_io_region header_location;
 254         struct log_header_disk *disk_header;
 255 };
 256
 257 /*
 258  * The touched member needs to be updated every time we access
 259  * one of the bitsets.
 260  */
 261 static inline int log_test_bit(uint32_t *bs, unsigned int bit)
 262 {
 263         return test_bit_le(bit, bs) ? 1 : 0;
 264 }
 265
 266 static inline void log_set_bit(struct log_c *l,
 267                                uint32_t *bs, unsigned int bit)
 268 {
 269         __set_bit_le(bit, bs);
 270         l->touched_cleaned = 1;
 271 }
 272
 273 static inline void log_clear_bit(struct log_c *l,
 274                                  uint32_t *bs, unsigned int bit)
 275 {
 276         __clear_bit_le(bit, bs);
 277         l->touched_dirtied = 1;
 278 }
 279
 280 /*
 281  *---------------------------------------------------------------
 282  * Header IO
 283  *--------------------------------------------------------------
 284  */
 285 static void header_to_disk(struct log_header_core *core, struct log_header_disk *disk)
 286 {
 287         disk->magic = cpu_to_le32(core->magic);
 288         disk->version = cpu_to_le32(core->version);
 289         disk->nr_regions = cpu_to_le64(core->nr_regions);
 290 }
 291
 292 static void header_from_disk(struct log_header_core *core, struct log_header_disk *disk)
 293 {
 294         core->magic = le32_to_cpu(disk->magic);
 295         core->version = le32_to_cpu(disk->version);
 296         core->nr_regions = le64_to_cpu(disk->nr_regions);
 297 }
 298
 299 static int rw_header(struct log_c *lc, enum req_op op)
 300 {
 301         lc->io_req.bi_opf = op;
 302
 303         return dm_io(&lc->io_req, 1, &lc->header_location, NULL, IOPRIO_DEFAULT);
 304 }
 305
 306 static int flush_header(struct log_c *lc)
 307 {
 308         struct dm_io_region null_location = {
 309                 .bdev = lc->header_location.bdev,
 310                 .sector = 0,
 311                 .count = 0,
 312         };
 313
 314         lc->io_req.bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
 315
 316         return dm_io(&lc->io_req, 1, &null_location, NULL, IOPRIO_DEFAULT);
 317 }
 318
 319 static int read_header(struct log_c *log)
 320 {
 321         int r;
 322
 323         r = rw_header(log, REQ_OP_READ);
 324         if (r)
 325                 return r;
 326
 327         header_from_disk(&log->header, log->disk_header);
 328
 329         /* New log required? */
 330         if (log->sync != DEFAULTSYNC || log->header.magic != MIRROR_MAGIC) {
 331                 log->header.magic = MIRROR_MAGIC;
 332                 log->header.version = MIRROR_DISK_VERSION;
 333                 log->header.nr_regions = 0;
 334         }
 335
 336 #ifdef __LITTLE_ENDIAN
 337         if (log->header.version == 1)
 338                 log->header.version = 2;
 339 #endif
 340
 341         if (log->header.version != MIRROR_DISK_VERSION) {
 342                 DMWARN("incompatible disk log version");
 343                 return -EINVAL;
 344         }
 345
 346         return 0;
 347 }
 348
 349 static int _check_region_size(struct dm_target *ti, uint32_t region_size)
 350 {
 351         if (region_size < 2 || region_size > ti->len)
 352                 return 0;
 353
 354         if (!is_power_of_2(region_size))
 355                 return 0;
 356
 357         return 1;
 358 }
 359
 360 /*
 361  *--------------------------------------------------------------
 362  * core log constructor/destructor
 363  *
 364  * argv contains region_size followed optionally by [no]sync
 365  *--------------------------------------------------------------
 366  */
 367 #define BYTE_SHIFT 3
 368 static int create_log_context(struct dm_dirty_log *log, struct dm_target *ti,
 369                               unsigned int argc, char **argv,
 370                               struct dm_dev *dev)
 371 {
 372         enum sync sync = DEFAULTSYNC;
 373
 374         struct log_c *lc;
 375         uint32_t region_size;
 376         unsigned int region_count;
 377         size_t bitset_size, buf_size;
 378         int r;
 379         char dummy;
 380
 381         if (argc < 1 || argc > 2) {
 382                 DMWARN("wrong number of arguments to dirty region log");
 383                 return -EINVAL;
 384         }
 385
 386         if (argc > 1) {
 387                 if (!strcmp(argv[1], "sync"))
 388                         sync = FORCESYNC;
 389                 else if (!strcmp(argv[1], "nosync"))
 390                         sync = NOSYNC;
 391                 else {
 392                         DMWARN("unrecognised sync argument to dirty region log: %s", argv[1]);
 393                         return -EINVAL;
 394                 }
 395         }
 396
 397         if (sscanf(argv[0], "%u%c", &region_size, &dummy) != 1 ||
 398             !_check_region_size(ti, region_size)) {
 399                 DMWARN("invalid region size %s", argv[0]);
 400                 return -EINVAL;
 401         }
 402
 403         region_count = dm_sector_div_up(ti->len, region_size);
 404
 405         lc = kmalloc(sizeof(*lc), GFP_KERNEL);
 406         if (!lc) {
 407                 DMWARN("couldn't allocate core log");
 408                 return -ENOMEM;
 409         }
 410
 411         lc->ti = ti;
 412         lc->touched_dirtied = 0;
 413         lc->touched_cleaned = 0;
 414         lc->flush_failed = 0;
 415         lc->region_size = region_size;
 416         lc->region_count = region_count;
 417         lc->sync = sync;
 418
 419         /*
 420          * Work out how many "unsigned long"s we need to hold the bitset.
 421          */
 422         bitset_size = dm_round_up(region_count, BITS_PER_LONG);
 423         bitset_size >>= BYTE_SHIFT;
 424
 425         lc->bitset_uint32_count = bitset_size / sizeof(*lc->clean_bits);
 426
 427         /*
 428          * Disk log?
 429          */
 430         if (!dev) {
 431                 lc->clean_bits = vmalloc(bitset_size);
 432                 if (!lc->clean_bits) {
 433                         DMWARN("couldn't allocate clean bitset");
 434                         kfree(lc);
 435                         return -ENOMEM;
 436                 }
 437                 lc->disk_header = NULL;
 438         } else {
 439                 lc->log_dev = dev;
 440                 lc->log_dev_failed = 0;
 441                 lc->log_dev_flush_failed = 0;
 442                 lc->header_location.bdev = lc->log_dev->bdev;
 443                 lc->header_location.sector = 0;
 444
 445                 /*
 446                  * Buffer holds both header and bitset.
 447                  */
 448                 buf_size =
 449                     dm_round_up((LOG_OFFSET << SECTOR_SHIFT) + bitset_size,
 450                                 bdev_logical_block_size(lc->header_location.bdev));
 451
 452                 if (buf_size > bdev_nr_bytes(dev->bdev)) {
 453                         DMWARN("log device %s too small: need %llu bytes",
 454                                 dev->name, (unsigned long long)buf_size);
 455                         kfree(lc);
 456                         return -EINVAL;
 457                 }
 458
 459                 lc->header_location.count = buf_size >> SECTOR_SHIFT;
 460
 461                 lc->io_req.mem.type = DM_IO_VMA;
 462                 lc->io_req.notify.fn = NULL;
 463                 lc->io_req.client = dm_io_client_create();
 464                 if (IS_ERR(lc->io_req.client)) {
 465                         r = PTR_ERR(lc->io_req.client);
 466                         DMWARN("couldn't allocate disk io client");
 467                         kfree(lc);
 468                         return r;
 469                 }
 470
 471                 lc->disk_header = vmalloc(buf_size);
 472                 if (!lc->disk_header) {
 473                         DMWARN("couldn't allocate disk log buffer");
 474                         dm_io_client_destroy(lc->io_req.client);
 475                         kfree(lc);
 476                         return -ENOMEM;
 477                 }
 478
 479                 lc->io_req.mem.ptr.vma = lc->disk_header;
 480                 lc->clean_bits = (void *)lc->disk_header +
 481                                  (LOG_OFFSET << SECTOR_SHIFT);
 482         }
 483
 484         memset(lc->clean_bits, -1, bitset_size);
 485
 486         lc->sync_bits = vmalloc(bitset_size);
 487         if (!lc->sync_bits) {
 488                 DMWARN("couldn't allocate sync bitset");
 489                 if (!dev)
 490                         vfree(lc->clean_bits);
 491                 else
 492                         dm_io_client_destroy(lc->io_req.client);
 493                 vfree(lc->disk_header);
 494                 kfree(lc);
 495                 return -ENOMEM;
 496         }
 497         memset(lc->sync_bits, (sync == NOSYNC) ? -1 : 0, bitset_size);
 498         lc->sync_count = (sync == NOSYNC) ? region_count : 0;
 499
 500         lc->recovering_bits = vzalloc(bitset_size);
 501         if (!lc->recovering_bits) {
 502                 DMWARN("couldn't allocate sync bitset");
 503                 vfree(lc->sync_bits);
 504                 if (!dev)
 505                         vfree(lc->clean_bits);
 506                 else
 507                         dm_io_client_destroy(lc->io_req.client);
 508                 vfree(lc->disk_header);
 509                 kfree(lc);
 510                 return -ENOMEM;
 511         }
 512         lc->sync_search = 0;
 513         log->context = lc;
 514
 515         return 0;
 516 }
 517
 518 static int core_ctr(struct dm_dirty_log *log, struct dm_target *ti,
 519                     unsigned int argc, char **argv)
 520 {
 521         return create_log_context(log, ti, argc, argv, NULL);
 522 }
 523
 524 static void destroy_log_context(struct log_c *lc)
 525 {
 526         vfree(lc->sync_bits);
 527         vfree(lc->recovering_bits);
 528         kfree(lc);
 529 }
 530
 531 static void core_dtr(struct dm_dirty_log *log)
 532 {
 533         struct log_c *lc = log->context;
 534
 535         vfree(lc->clean_bits);
 536         destroy_log_context(lc);
 537 }
 538
 539 /*
 540  *---------------------------------------------------------------------
 541  * disk log constructor/destructor
 542  *
 543  * argv contains log_device region_size followed optionally by [no]sync
 544  *---------------------------------------------------------------------
 545  */
 546 static int disk_ctr(struct dm_dirty_log *log, struct dm_target *ti,
 547                     unsigned int argc, char **argv)
 548 {
 549         int r;
 550         struct dm_dev *dev;
 551
 552         if (argc < 2 || argc > 3) {
 553                 DMWARN("wrong number of arguments to disk dirty region log");
 554                 return -EINVAL;
 555         }
 556
 557         r = dm_get_device(ti, argv[0], dm_table_get_mode(ti->table), &dev);
 558         if (r)
 559                 return r;
 560
 561         r = create_log_context(log, ti, argc - 1, argv + 1, dev);
 562         if (r) {
 563                 dm_put_device(ti, dev);
 564                 return r;
 565         }
 566
 567         return 0;
 568 }
 569
 570 static void disk_dtr(struct dm_dirty_log *log)
 571 {
 572         struct log_c *lc = log->context;
 573
 574         dm_put_device(lc->ti, lc->log_dev);
 575         vfree(lc->disk_header);
 576         dm_io_client_destroy(lc->io_req.client);
 577         destroy_log_context(lc);
 578 }
 579
 580 static void fail_log_device(struct log_c *lc)
 581 {
 582         if (lc->log_dev_failed)
 583                 return;
 584
 585         lc->log_dev_failed = 1;
 586         dm_table_event(lc->ti->table);
 587 }
 588
 589 static int disk_resume(struct dm_dirty_log *log)
 590 {
 591         int r;
 592         unsigned int i;
 593         struct log_c *lc = log->context;
 594         size_t size = lc->bitset_uint32_count * sizeof(uint32_t);
 595
 596         /* read the disk header */
 597         r = read_header(lc);
 598         if (r) {
 599                 DMWARN("%s: Failed to read header on dirty region log device",
 600                        lc->log_dev->name);
 601                 fail_log_device(lc);
 602                 /*
 603                  * If the log device cannot be read, we must assume
 604                  * all regions are out-of-sync.  If we simply return
 605                  * here, the state will be uninitialized and could
 606                  * lead us to return 'in-sync' status for regions
 607                  * that are actually 'out-of-sync'.
 608                  */
 609                 lc->header.nr_regions = 0;
 610         }
 611
 612         /* set or clear any new bits -- device has grown */
 613         if (lc->sync == NOSYNC)
 614                 for (i = lc->header.nr_regions; i < lc->region_count; i++)
 615                         /* FIXME: amazingly inefficient */
 616                         log_set_bit(lc, lc->clean_bits, i);
 617         else
 618                 for (i = lc->header.nr_regions; i < lc->region_count; i++)
 619                         /* FIXME: amazingly inefficient */
 620                         log_clear_bit(lc, lc->clean_bits, i);
 621
 622         /* clear any old bits -- device has shrunk */
 623         for (i = lc->region_count; i % BITS_PER_LONG; i++)
 624                 log_clear_bit(lc, lc->clean_bits, i);
 625
 626         /* copy clean across to sync */
 627         memcpy(lc->sync_bits, lc->clean_bits, size);
 628         lc->sync_count = memweight(lc->clean_bits,
 629                                 lc->bitset_uint32_count * sizeof(uint32_t));
 630         lc->sync_search = 0;
 631
 632         /* set the correct number of regions in the header */
 633         lc->header.nr_regions = lc->region_count;
 634
 635         header_to_disk(&lc->header, lc->disk_header);
 636
 637         /* write the new header */
 638         r = rw_header(lc, REQ_OP_WRITE);
 639         if (!r) {
 640                 r = flush_header(lc);
 641                 if (r)
 642                         lc->log_dev_flush_failed = 1;
 643         }
 644         if (r) {
 645                 DMWARN("%s: Failed to write header on dirty region log device",
 646                        lc->log_dev->name);
 647                 fail_log_device(lc);
 648         }
 649
 650         return r;
 651 }
 652
 653 static uint32_t core_get_region_size(struct dm_dirty_log *log)
 654 {
 655         struct log_c *lc = log->context;
 656
 657         return lc->region_size;
 658 }
 659
 660 static int core_resume(struct dm_dirty_log *log)
 661 {
 662         struct log_c *lc = log->context;
 663
 664         lc->sync_search = 0;
 665         return 0;
 666 }
 667
 668 static int core_is_clean(struct dm_dirty_log *log, region_t region)
 669 {
 670         struct log_c *lc = log->context;
 671
 672         return log_test_bit(lc->clean_bits, region);
 673 }
 674
 675 static int core_in_sync(struct dm_dirty_log *log, region_t region, int block)
 676 {
 677         struct log_c *lc = log->context;
 678
 679         return log_test_bit(lc->sync_bits, region);
 680 }
 681
 682 static int core_flush(struct dm_dirty_log *log)
 683 {
 684         /* no op */
 685         return 0;
 686 }
 687
 688 static int disk_flush(struct dm_dirty_log *log)
 689 {
 690         int r, i;
 691         struct log_c *lc = log->context;
 692
 693         /* only write if the log has changed */
 694         if (!lc->touched_cleaned && !lc->touched_dirtied)
 695                 return 0;
 696
 697         if (lc->touched_cleaned && log->flush_callback_fn &&
 698             log->flush_callback_fn(lc->ti)) {
 699                 /*
 700                  * At this point it is impossible to determine which
 701                  * regions are clean and which are dirty (without
 702                  * re-reading the log off disk). So mark all of them
 703                  * dirty.
 704                  */
 705                 lc->flush_failed = 1;
 706                 for (i = 0; i < lc->region_count; i++)
 707                         log_clear_bit(lc, lc->clean_bits, i);
 708         }
 709
 710         r = rw_header(lc, REQ_OP_WRITE);
 711         if (r)
 712                 fail_log_device(lc);
 713         else {
 714                 if (lc->touched_dirtied) {
 715                         r = flush_header(lc);
 716                         if (r) {
 717                                 lc->log_dev_flush_failed = 1;
 718                                 fail_log_device(lc);
 719                         } else
 720                                 lc->touched_dirtied = 0;
 721                 }
 722                 lc->touched_cleaned = 0;
 723         }
 724
 725         return r;
 726 }
 727
 728 static void core_mark_region(struct dm_dirty_log *log, region_t region)
 729 {
 730         struct log_c *lc = log->context;
 731
 732         log_clear_bit(lc, lc->clean_bits, region);
 733 }
 734
 735 static void core_clear_region(struct dm_dirty_log *log, region_t region)
 736 {
 737         struct log_c *lc = log->context;
 738
 739         if (likely(!lc->flush_failed))
 740                 log_set_bit(lc, lc->clean_bits, region);
 741 }
 742
 743 static int core_get_resync_work(struct dm_dirty_log *log, region_t *region)
 744 {
 745         struct log_c *lc = log->context;
 746
 747         if (lc->sync_search >= lc->region_count)
 748                 return 0;
 749
 750         do {
 751                 *region = find_next_zero_bit_le(lc->sync_bits,
 752                                              lc->region_count,
 753                                              lc->sync_search);
 754                 lc->sync_search = *region + 1;
 755
 756                 if (*region >= lc->region_count)
 757                         return 0;
 758
 759         } while (log_test_bit(lc->recovering_bits, *region));
 760
 761         log_set_bit(lc, lc->recovering_bits, *region);
 762         return 1;
 763 }
 764
 765 static void core_set_region_sync(struct dm_dirty_log *log, region_t region,
 766                                  int in_sync)
 767 {
 768         struct log_c *lc = log->context;
 769
 770         log_clear_bit(lc, lc->recovering_bits, region);
 771         if (in_sync) {
 772                 log_set_bit(lc, lc->sync_bits, region);
 773                 lc->sync_count++;
 774         } else if (log_test_bit(lc->sync_bits, region)) {
 775                 lc->sync_count--;
 776                 log_clear_bit(lc, lc->sync_bits, region);
 777         }
 778 }
 779
 780 static region_t core_get_sync_count(struct dm_dirty_log *log)
 781 {
 782         struct log_c *lc = log->context;
 783
 784         return lc->sync_count;
 785 }
 786
 787 #define DMEMIT_SYNC \
 788         do { \
 789                 if (lc->sync != DEFAULTSYNC) \
 790                         DMEMIT("%ssync ", lc->sync == NOSYNC ? "no" : ""); \
 791         } while (0)
 792
 793 static int core_status(struct dm_dirty_log *log, status_type_t status,
 794                        char *result, unsigned int maxlen)
 795 {
 796         int sz = 0;
 797         struct log_c *lc = log->context;
 798
 799         switch (status) {
 800         case STATUSTYPE_INFO:
 801                 DMEMIT("1 %s", log->type->name);
 802                 break;
 803
 804         case STATUSTYPE_TABLE:
 805                 DMEMIT("%s %u %u ", log->type->name,
 806                        lc->sync == DEFAULTSYNC ? 1 : 2, lc->region_size);
 807                 DMEMIT_SYNC;
 808                 break;
 809
 810         case STATUSTYPE_IMA:
 811                 *result = '\0';
 812                 break;
 813         }
 814
 815         return sz;
 816 }
 817
 818 static int disk_status(struct dm_dirty_log *log, status_type_t status,
 819                        char *result, unsigned int maxlen)
 820 {
 821         int sz = 0;
 822         struct log_c *lc = log->context;
 823
 824         switch (status) {
 825         case STATUSTYPE_INFO:
 826                 DMEMIT("3 %s %s %c", log->type->name, lc->log_dev->name,
 827                        lc->log_dev_flush_failed ? 'F' :
 828                        lc->log_dev_failed ? 'D' :
 829                        'A');
 830                 break;
 831
 832         case STATUSTYPE_TABLE:
 833                 DMEMIT("%s %u %s %u ", log->type->name,
 834                        lc->sync == DEFAULTSYNC ? 2 : 3, lc->log_dev->name,
 835                        lc->region_size);
 836                 DMEMIT_SYNC;
 837                 break;
 838
 839         case STATUSTYPE_IMA:
 840                 *result = '\0';
 841                 break;
 842         }
 843
 844         return sz;
 845 }
 846
 847 static struct dm_dirty_log_type _core_type = {
 848         .name = "core",
 849         .module = THIS_MODULE,
 850         .ctr = core_ctr,
 851         .dtr = core_dtr,
 852         .resume = core_resume,
 853         .get_region_size = core_get_region_size,
 854         .is_clean = core_is_clean,
 855         .in_sync = core_in_sync,
 856         .flush = core_flush,
 857         .mark_region = core_mark_region,
 858         .clear_region = core_clear_region,
 859         .get_resync_work = core_get_resync_work,
 860         .set_region_sync = core_set_region_sync,
 861         .get_sync_count = core_get_sync_count,
 862         .status = core_status,
 863 };
 864
 865 static struct dm_dirty_log_type _disk_type = {
 866         .name = "disk",
 867         .module = THIS_MODULE,
 868         .ctr = disk_ctr,
 869         .dtr = disk_dtr,
 870         .postsuspend = disk_flush,
 871         .resume = disk_resume,
 872         .get_region_size = core_get_region_size,
 873         .is_clean = core_is_clean,
 874         .in_sync = core_in_sync,
 875         .flush = disk_flush,
 876         .mark_region = core_mark_region,
 877         .clear_region = core_clear_region,
 878         .get_resync_work = core_get_resync_work,
 879         .set_region_sync = core_set_region_sync,
 880         .get_sync_count = core_get_sync_count,
 881         .status = disk_status,
 882 };
 883
 884 static int __init dm_dirty_log_init(void)
 885 {
 886         int r;
 887
 888         r = dm_dirty_log_type_register(&_core_type);
 889         if (r)
 890                 DMWARN("couldn't register core log");
 891
 892         r = dm_dirty_log_type_register(&_disk_type);
 893         if (r) {
 894                 DMWARN("couldn't register disk type");
 895                 dm_dirty_log_type_unregister(&_core_type);
 896         }
 897
 898         return r;
 899 }
 900
 901 static void __exit dm_dirty_log_exit(void)
 902 {
 903         dm_dirty_log_type_unregister(&_disk_type);
 904         dm_dirty_log_type_unregister(&_core_type);
 905 }
 906
 907 module_init(dm_dirty_log_init);
 908 module_exit(dm_dirty_log_exit);
 909
 910 MODULE_DESCRIPTION(DM_NAME " dirty region log");
 911 MODULE_AUTHOR("Joe Thornber, Heinz Mauelshagen <[email protected]>");
 912 MODULE_LICENSE("GPL");