drivers/md/dm-raid.c

   1 /*
   2  * Copyright (C) 2010-2011 Neil Brown
   3  * Copyright (C) 2010-2011 Red Hat, Inc. All rights reserved.
   4  *
   5  * This file is released under the GPL.
   6  */
   7
   8 #include <linux/slab.h>
   9 #include <linux/module.h>
  10
  11 #include "md.h"
  12 #include "raid1.h"
  13 #include "raid5.h"
  14 #include "raid10.h"
  15 #include "bitmap.h"
  16
  17 #include <linux/device-mapper.h>
  18
  19 #define DM_MSG_PREFIX "raid"
  20
  21 /*
  22  * The following flags are used by dm-raid.c to set up the array state.
  23  * They must be cleared before md_run is called.
  24  */
  25 #define FirstUse 10             /* rdev flag */
  26
  27 struct raid_dev {
  28         /*
  29          * Two DM devices, one to hold metadata and one to hold the
  30          * actual data/parity.  The reason for this is to not confuse
  31          * ti->len and give more flexibility in altering size and
  32          * characteristics.
  33          *
  34          * While it is possible for this device to be associated
  35          * with a different physical device than the data_dev, it
  36          * is intended for it to be the same.
  37          *    |--------- Physical Device ---------|
  38          *    |- meta_dev -|------ data_dev ------|
  39          */
  40         struct dm_dev *meta_dev;
  41         struct dm_dev *data_dev;
  42         struct md_rdev rdev;
  43 };
  44
  45 /*
  46  * Flags for rs->print_flags field.
  47  */
  48 #define DMPF_SYNC              0x1
  49 #define DMPF_NOSYNC            0x2
  50 #define DMPF_REBUILD           0x4
  51 #define DMPF_DAEMON_SLEEP      0x8
  52 #define DMPF_MIN_RECOVERY_RATE 0x10
  53 #define DMPF_MAX_RECOVERY_RATE 0x20
  54 #define DMPF_MAX_WRITE_BEHIND  0x40
  55 #define DMPF_STRIPE_CACHE      0x80
  56 #define DMPF_REGION_SIZE       0x100
  57 #define DMPF_RAID10_COPIES     0x200
  58 #define DMPF_RAID10_FORMAT     0x400
  59
  60 struct raid_set {
  61         struct dm_target *ti;
  62
  63         uint32_t bitmap_loaded;
  64         uint32_t print_flags;
  65
  66         struct mddev md;
  67         struct raid_type *raid_type;
  68         struct dm_target_callbacks callbacks;
  69
  70         struct raid_dev dev[0];
  71 };
  72
  73 /* Supported raid types and properties. */
  74 static struct raid_type {
  75         const char *name;               /* RAID algorithm. */
  76         const char *descr;              /* Descriptor text for logging. */
  77         const unsigned parity_devs;     /* # of parity devices. */
  78         const unsigned minimal_devs;    /* minimal # of devices in set. */
  79         const unsigned level;           /* RAID level. */
  80         const unsigned algorithm;       /* RAID algorithm. */
  81 } raid_types[] = {
  82         {"raid1",    "RAID1 (mirroring)",               0, 2, 1, 0 /* NONE */},
  83         {"raid10",   "RAID10 (striped mirrors)",        0, 2, 10, UINT_MAX /* Varies */},
  84         {"raid4",    "RAID4 (dedicated parity disk)",   1, 2, 5, ALGORITHM_PARITY_0},
  85         {"raid5_la", "RAID5 (left asymmetric)",         1, 2, 5, ALGORITHM_LEFT_ASYMMETRIC},
  86         {"raid5_ra", "RAID5 (right asymmetric)",        1, 2, 5, ALGORITHM_RIGHT_ASYMMETRIC},
  87         {"raid5_ls", "RAID5 (left symmetric)",          1, 2, 5, ALGORITHM_LEFT_SYMMETRIC},
  88         {"raid5_rs", "RAID5 (right symmetric)",         1, 2, 5, ALGORITHM_RIGHT_SYMMETRIC},
  89         {"raid6_zr", "RAID6 (zero restart)",            2, 4, 6, ALGORITHM_ROTATING_ZERO_RESTART},
  90         {"raid6_nr", "RAID6 (N restart)",               2, 4, 6, ALGORITHM_ROTATING_N_RESTART},
  91         {"raid6_nc", "RAID6 (N continue)",              2, 4, 6, ALGORITHM_ROTATING_N_CONTINUE}
  92 };
  93
  94 static unsigned raid10_md_layout_to_copies(int layout)
  95 {
  96         return layout & 0xFF;
  97 }
  98
  99 static int raid10_format_to_md_layout(char *format, unsigned copies)
 100 {
 101         /* 1 "far" copy, and 'copies' "near" copies */
 102         return (1 << 8) | (copies & 0xFF);
 103 }
 104
 105 static struct raid_type *get_raid_type(char *name)
 106 {
 107         int i;
 108
 109         for (i = 0; i < ARRAY_SIZE(raid_types); i++)
 110                 if (!strcmp(raid_types[i].name, name))
 111                         return &raid_types[i];
 112
 113         return NULL;
 114 }
 115
 116 static struct raid_set *context_alloc(struct dm_target *ti, struct raid_type *raid_type, unsigned raid_devs)
 117 {
 118         unsigned i;
 119         struct raid_set *rs;
 120
 121         if (raid_devs <= raid_type->parity_devs) {
 122                 ti->error = "Insufficient number of devices";
 123                 return ERR_PTR(-EINVAL);
 124         }
 125
 126         rs = kzalloc(sizeof(*rs) + raid_devs * sizeof(rs->dev[0]), GFP_KERNEL);
 127         if (!rs) {
 128                 ti->error = "Cannot allocate raid context";
 129                 return ERR_PTR(-ENOMEM);
 130         }
 131
 132         mddev_init(&rs->md);
 133
 134         rs->ti = ti;
 135         rs->raid_type = raid_type;
 136         rs->md.raid_disks = raid_devs;
 137         rs->md.level = raid_type->level;
 138         rs->md.new_level = rs->md.level;
 139         rs->md.layout = raid_type->algorithm;
 140         rs->md.new_layout = rs->md.layout;
 141         rs->md.delta_disks = 0;
 142         rs->md.recovery_cp = 0;
 143
 144         for (i = 0; i < raid_devs; i++)
 145                 md_rdev_init(&rs->dev[i].rdev);
 146
 147         /*
 148          * Remaining items to be initialized by further RAID params:
 149          *  rs->md.persistent
 150          *  rs->md.external
 151          *  rs->md.chunk_sectors
 152          *  rs->md.new_chunk_sectors
 153          *  rs->md.dev_sectors
 154          */
 155
 156         return rs;
 157 }
 158
 159 static void context_free(struct raid_set *rs)
 160 {
 161         int i;
 162
 163         for (i = 0; i < rs->md.raid_disks; i++) {
 164                 if (rs->dev[i].meta_dev)
 165                         dm_put_device(rs->ti, rs->dev[i].meta_dev);
 166                 md_rdev_clear(&rs->dev[i].rdev);
 167                 if (rs->dev[i].data_dev)
 168                         dm_put_device(rs->ti, rs->dev[i].data_dev);
 169         }
 170
 171         kfree(rs);
 172 }
 173
 174 /*
 175  * For every device we have two words
 176  *  <meta_dev>: meta device name or '-' if missing
 177  *  <data_dev>: data device name or '-' if missing
 178  *
 179  * The following are permitted:
 180  *    - -
 181  *    - <data_dev>
 182  *    <meta_dev> <data_dev>
 183  *
 184  * The following is not allowed:
 185  *    <meta_dev> -
 186  *
 187  * This code parses those words.  If there is a failure,
 188  * the caller must use context_free to unwind the operations.
 189  */
 190 static int dev_parms(struct raid_set *rs, char **argv)
 191 {
 192         int i;
 193         int rebuild = 0;
 194         int metadata_available = 0;
 195         int ret = 0;
 196
 197         for (i = 0; i < rs->md.raid_disks; i++, argv += 2) {
 198                 rs->dev[i].rdev.raid_disk = i;
 199
 200                 rs->dev[i].meta_dev = NULL;
 201                 rs->dev[i].data_dev = NULL;
 202
 203                 /*
 204                  * There are no offsets, since there is a separate device
 205                  * for data and metadata.
 206                  */
 207                 rs->dev[i].rdev.data_offset = 0;
 208                 rs->dev[i].rdev.mddev = &rs->md;
 209
 210                 if (strcmp(argv[0], "-")) {
 211                         ret = dm_get_device(rs->ti, argv[0],
 212                                             dm_table_get_mode(rs->ti->table),
 213                                             &rs->dev[i].meta_dev);
 214                         rs->ti->error = "RAID metadata device lookup failure";
 215                         if (ret)
 216                                 return ret;
 217
 218                         rs->dev[i].rdev.sb_page = alloc_page(GFP_KERNEL);
 219                         if (!rs->dev[i].rdev.sb_page)
 220                                 return -ENOMEM;
 221                 }
 222
 223                 if (!strcmp(argv[1], "-")) {
 224                         if (!test_bit(In_sync, &rs->dev[i].rdev.flags) &&
 225                             (!rs->dev[i].rdev.recovery_offset)) {
 226                                 rs->ti->error = "Drive designated for rebuild not specified";
 227                                 return -EINVAL;
 228                         }
 229
 230                         rs->ti->error = "No data device supplied with metadata device";
 231                         if (rs->dev[i].meta_dev)
 232                                 return -EINVAL;
 233
 234                         continue;
 235                 }
 236
 237                 ret = dm_get_device(rs->ti, argv[1],
 238                                     dm_table_get_mode(rs->ti->table),
 239                                     &rs->dev[i].data_dev);
 240                 if (ret) {
 241                         rs->ti->error = "RAID device lookup failure";
 242                         return ret;
 243                 }
 244
 245                 if (rs->dev[i].meta_dev) {
 246                         metadata_available = 1;
 247                         rs->dev[i].rdev.meta_bdev = rs->dev[i].meta_dev->bdev;
 248                 }
 249                 rs->dev[i].rdev.bdev = rs->dev[i].data_dev->bdev;
 250                 list_add(&rs->dev[i].rdev.same_set, &rs->md.disks);
 251                 if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
 252                         rebuild++;
 253         }
 254
 255         if (metadata_available) {
 256                 rs->md.external = 0;
 257                 rs->md.persistent = 1;
 258                 rs->md.major_version = 2;
 259         } else if (rebuild && !rs->md.recovery_cp) {
 260                 /*
 261                  * Without metadata, we will not be able to tell if the array
 262                  * is in-sync or not - we must assume it is not.  Therefore,
 263                  * it is impossible to rebuild a drive.
 264                  *
 265                  * Even if there is metadata, the on-disk information may
 266                  * indicate that the array is not in-sync and it will then
 267                  * fail at that time.
 268                  *
 269                  * User could specify 'nosync' option if desperate.
 270                  */
 271                 DMERR("Unable to rebuild drive while array is not in-sync");
 272                 rs->ti->error = "RAID device lookup failure";
 273                 return -EINVAL;
 274         }
 275
 276         return 0;
 277 }
 278
 279 /*
 280  * validate_region_size
 281  * @rs
 282  * @region_size:  region size in sectors.  If 0, pick a size (4MiB default).
 283  *
 284  * Set rs->md.bitmap_info.chunksize (which really refers to 'region size').
 285  * Ensure that (ti->len/region_size < 2^21) - required by MD bitmap.
 286  *
 287  * Returns: 0 on success, -EINVAL on failure.
 288  */
 289 static int validate_region_size(struct raid_set *rs, unsigned long region_size)
 290 {
 291         unsigned long min_region_size = rs->ti->len / (1 << 21);
 292
 293         if (!region_size) {
 294                 /*
 295                  * Choose a reasonable default.  All figures in sectors.
 296                  */
 297                 if (min_region_size > (1 << 13)) {
 298                         DMINFO("Choosing default region size of %lu sectors",
 299                                region_size);
 300                         region_size = min_region_size;
 301                 } else {
 302                         DMINFO("Choosing default region size of 4MiB");
 303                         region_size = 1 << 13; /* sectors */
 304                 }
 305         } else {
 306                 /*
 307                  * Validate user-supplied value.
 308                  */
 309                 if (region_size > rs->ti->len) {
 310                         rs->ti->error = "Supplied region size is too large";
 311                         return -EINVAL;
 312                 }
 313
 314                 if (region_size < min_region_size) {
 315                         DMERR("Supplied region_size (%lu sectors) below minimum (%lu)",
 316                               region_size, min_region_size);
 317                         rs->ti->error = "Supplied region size is too small";
 318                         return -EINVAL;
 319                 }
 320
 321                 if (!is_power_of_2(region_size)) {
 322                         rs->ti->error = "Region size is not a power of 2";
 323                         return -EINVAL;
 324                 }
 325
 326                 if (region_size < rs->md.chunk_sectors) {
 327                         rs->ti->error = "Region size is smaller than the chunk size";
 328                         return -EINVAL;
 329                 }
 330         }
 331
 332         /*
 333          * Convert sectors to bytes.
 334          */
 335         rs->md.bitmap_info.chunksize = (region_size << 9);
 336
 337         return 0;
 338 }
 339
 340 /*
 341  * validate_rebuild_devices
 342  * @rs
 343  *
 344  * Determine if the devices specified for rebuild can result in a valid
 345  * usable array that is capable of rebuilding the given devices.
 346  *
 347  * Returns: 0 on success, -EINVAL on failure.
 348  */
 349 static int validate_rebuild_devices(struct raid_set *rs)
 350 {
 351         unsigned i, rebuild_cnt = 0;
 352         unsigned rebuilds_per_group, copies, d;
 353
 354         if (!(rs->print_flags & DMPF_REBUILD))
 355                 return 0;
 356
 357         for (i = 0; i < rs->md.raid_disks; i++)
 358                 if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
 359                         rebuild_cnt++;
 360
 361         switch (rs->raid_type->level) {
 362         case 1:
 363                 if (rebuild_cnt >= rs->md.raid_disks)
 364                         goto too_many;
 365                 break;
 366         case 4:
 367         case 5:
 368         case 6:
 369                 if (rebuild_cnt > rs->raid_type->parity_devs)
 370                         goto too_many;
 371                 break;
 372         case 10:
 373                 copies = raid10_md_layout_to_copies(rs->md.layout);
 374                 if (rebuild_cnt < copies)
 375                         break;
 376
 377                 /*
 378                  * It is possible to have a higher rebuild count for RAID10,
 379                  * as long as the failed devices occur in different mirror
 380                  * groups (i.e. different stripes).
 381                  *
 382                  * Right now, we only allow for "near" copies.  When other
 383                  * formats are added, we will have to check those too.
 384                  *
 385                  * When checking "near" format, make sure no adjacent devices
 386                  * have failed beyond what can be handled.  In addition to the
 387                  * simple case where the number of devices is a multiple of the
 388                  * number of copies, we must also handle cases where the number
 389                  * of devices is not a multiple of the number of copies.
 390                  * E.g.    dev1 dev2 dev3 dev4 dev5
 391                  *          A    A    B    B    C
 392                  *          C    D    D    E    E
 393                  */
 394                 rebuilds_per_group = 0;
 395                 for (i = 0; i < rs->md.raid_disks * copies; i++) {
 396                         d = i % rs->md.raid_disks;
 397                         if (!test_bit(In_sync, &rs->dev[d].rdev.flags) &&
 398                             (++rebuilds_per_group >= copies))
 399                                 goto too_many;
 400                         if (!((i + 1) % copies))
 401                                 rebuilds_per_group = 0;
 402                 }
 403                 break;
 404         default:
 405                 DMERR("The rebuild parameter is not supported for %s",
 406                       rs->raid_type->name);
 407                 rs->ti->error = "Rebuild not supported for this RAID type";
 408                 return -EINVAL;
 409         }
 410
 411         return 0;
 412
 413 too_many:
 414         rs->ti->error = "Too many rebuild devices specified";
 415         return -EINVAL;
 416 }
 417
 418 /*
 419  * Possible arguments are...
 420  *      <chunk_size> [optional_args]
 421  *
 422  * Argument definitions
 423  *    <chunk_size>                      The number of sectors per disk that
 424  *                                      will form the "stripe"
 425  *    [[no]sync]                        Force or prevent recovery of the
 426  *                                      entire array
 427  *    [rebuild <idx>]                   Rebuild the drive indicated by the index
 428  *    [daemon_sleep <ms>]               Time between bitmap daemon work to
 429  *                                      clear bits
 430  *    [min_recovery_rate <kB/sec/disk>] Throttle RAID initialization
 431  *    [max_recovery_rate <kB/sec/disk>] Throttle RAID initialization
 432  *    [write_mostly <idx>]              Indicate a write mostly drive via index
 433  *    [max_write_behind <sectors>]      See '-write-behind=' (man mdadm)
 434  *    [stripe_cache <sectors>]          Stripe cache size for higher RAIDs
 435  *    [region_size <sectors>]           Defines granularity of bitmap
 436  *
 437  * RAID10-only options:
 438  *    [raid10_copies <# copies>]        Number of copies.  (Default: 2)
 439  *    [raid10_format <near>]            Layout algorithm.  (Default: near)
 440  */
 441 static int parse_raid_params(struct raid_set *rs, char **argv,
 442                              unsigned num_raid_params)
 443 {
 444         char *raid10_format = "near";
 445         unsigned raid10_copies = 2;
 446         unsigned i;
 447         unsigned long value, region_size = 0;
 448         sector_t sectors_per_dev = rs->ti->len;
 449         sector_t max_io_len;
 450         char *key;
 451
 452         /*
 453          * First, parse the in-order required arguments
 454          * "chunk_size" is the only argument of this type.
 455          */
 456         if ((strict_strtoul(argv[0], 10, &value) < 0)) {
 457                 rs->ti->error = "Bad chunk size";
 458                 return -EINVAL;
 459         } else if (rs->raid_type->level == 1) {
 460                 if (value)
 461                         DMERR("Ignoring chunk size parameter for RAID 1");
 462                 value = 0;
 463         } else if (!is_power_of_2(value)) {
 464                 rs->ti->error = "Chunk size must be a power of 2";
 465                 return -EINVAL;
 466         } else if (value < 8) {
 467                 rs->ti->error = "Chunk size value is too small";
 468                 return -EINVAL;
 469         }
 470
 471         rs->md.new_chunk_sectors = rs->md.chunk_sectors = value;
 472         argv++;
 473         num_raid_params--;
 474
 475         /*
 476          * We set each individual device as In_sync with a completed
 477          * 'recovery_offset'.  If there has been a device failure or
 478          * replacement then one of the following cases applies:
 479          *
 480          *   1) User specifies 'rebuild'.
 481          *      - Device is reset when param is read.
 482          *   2) A new device is supplied.
 483          *      - No matching superblock found, resets device.
 484          *   3) Device failure was transient and returns on reload.
 485          *      - Failure noticed, resets device for bitmap replay.
 486          *   4) Device hadn't completed recovery after previous failure.
 487          *      - Superblock is read and overrides recovery_offset.
 488          *
 489          * What is found in the superblocks of the devices is always
 490          * authoritative, unless 'rebuild' or '[no]sync' was specified.
 491          */
 492         for (i = 0; i < rs->md.raid_disks; i++) {
 493                 set_bit(In_sync, &rs->dev[i].rdev.flags);
 494                 rs->dev[i].rdev.recovery_offset = MaxSector;
 495         }
 496
 497         /*
 498          * Second, parse the unordered optional arguments
 499          */
 500         for (i = 0; i < num_raid_params; i++) {
 501                 if (!strcasecmp(argv[i], "nosync")) {
 502                         rs->md.recovery_cp = MaxSector;
 503                         rs->print_flags |= DMPF_NOSYNC;
 504                         continue;
 505                 }
 506                 if (!strcasecmp(argv[i], "sync")) {
 507                         rs->md.recovery_cp = 0;
 508                         rs->print_flags |= DMPF_SYNC;
 509                         continue;
 510                 }
 511
 512                 /* The rest of the optional arguments come in key/value pairs */
 513                 if ((i + 1) >= num_raid_params) {
 514                         rs->ti->error = "Wrong number of raid parameters given";
 515                         return -EINVAL;
 516                 }
 517
 518                 key = argv[i++];
 519
 520                 /* Parameters that take a string value are checked here. */
 521                 if (!strcasecmp(key, "raid10_format")) {
 522                         if (rs->raid_type->level != 10) {
 523                                 rs->ti->error = "'raid10_format' is an invalid parameter for this RAID type";
 524                                 return -EINVAL;
 525                         }
 526                         if (strcmp("near", argv[i])) {
 527                                 rs->ti->error = "Invalid 'raid10_format' value given";
 528                                 return -EINVAL;
 529                         }
 530                         raid10_format = argv[i];
 531                         rs->print_flags |= DMPF_RAID10_FORMAT;
 532                         continue;
 533                 }
 534
 535                 if (strict_strtoul(argv[i], 10, &value) < 0) {
 536                         rs->ti->error = "Bad numerical argument given in raid params";
 537                         return -EINVAL;
 538                 }
 539
 540                 /* Parameters that take a numeric value are checked here */
 541                 if (!strcasecmp(key, "rebuild")) {
 542                         if (value >= rs->md.raid_disks) {
 543                                 rs->ti->error = "Invalid rebuild index given";
 544                                 return -EINVAL;
 545                         }
 546                         clear_bit(In_sync, &rs->dev[value].rdev.flags);
 547                         rs->dev[value].rdev.recovery_offset = 0;
 548                         rs->print_flags |= DMPF_REBUILD;
 549                 } else if (!strcasecmp(key, "write_mostly")) {
 550                         if (rs->raid_type->level != 1) {
 551                                 rs->ti->error = "write_mostly option is only valid for RAID1";
 552                                 return -EINVAL;
 553                         }
 554                         if (value >= rs->md.raid_disks) {
 555                                 rs->ti->error = "Invalid write_mostly drive index given";
 556                                 return -EINVAL;
 557                         }
 558                         set_bit(WriteMostly, &rs->dev[value].rdev.flags);
 559                 } else if (!strcasecmp(key, "max_write_behind")) {
 560                         if (rs->raid_type->level != 1) {
 561                                 rs->ti->error = "max_write_behind option is only valid for RAID1";
 562                                 return -EINVAL;
 563                         }
 564                         rs->print_flags |= DMPF_MAX_WRITE_BEHIND;
 565
 566                         /*
 567                          * In device-mapper, we specify things in sectors, but
 568                          * MD records this value in kB
 569                          */
 570                         value /= 2;
 571                         if (value > COUNTER_MAX) {
 572                                 rs->ti->error = "Max write-behind limit out of range";
 573                                 return -EINVAL;
 574                         }
 575                         rs->md.bitmap_info.max_write_behind = value;
 576                 } else if (!strcasecmp(key, "daemon_sleep")) {
 577                         rs->print_flags |= DMPF_DAEMON_SLEEP;
 578                         if (!value || (value > MAX_SCHEDULE_TIMEOUT)) {
 579                                 rs->ti->error = "daemon sleep period out of range";
 580                                 return -EINVAL;
 581                         }
 582                         rs->md.bitmap_info.daemon_sleep = value;
 583                 } else if (!strcasecmp(key, "stripe_cache")) {
 584                         rs->print_flags |= DMPF_STRIPE_CACHE;
 585
 586                         /*
 587                          * In device-mapper, we specify things in sectors, but
 588                          * MD records this value in kB
 589                          */
 590                         value /= 2;
 591
 592                         if ((rs->raid_type->level != 5) &&
 593                             (rs->raid_type->level != 6)) {
 594                                 rs->ti->error = "Inappropriate argument: stripe_cache";
 595                                 return -EINVAL;
 596                         }
 597                         if (raid5_set_cache_size(&rs->md, (int)value)) {
 598                                 rs->ti->error = "Bad stripe_cache size";
 599                                 return -EINVAL;
 600                         }
 601                 } else if (!strcasecmp(key, "min_recovery_rate")) {
 602                         rs->print_flags |= DMPF_MIN_RECOVERY_RATE;
 603                         if (value > INT_MAX) {
 604                                 rs->ti->error = "min_recovery_rate out of range";
 605                                 return -EINVAL;
 606                         }
 607                         rs->md.sync_speed_min = (int)value;
 608                 } else if (!strcasecmp(key, "max_recovery_rate")) {
 609                         rs->print_flags |= DMPF_MAX_RECOVERY_RATE;
 610                         if (value > INT_MAX) {
 611                                 rs->ti->error = "max_recovery_rate out of range";
 612                                 return -EINVAL;
 613                         }
 614                         rs->md.sync_speed_max = (int)value;
 615                 } else if (!strcasecmp(key, "region_size")) {
 616                         rs->print_flags |= DMPF_REGION_SIZE;
 617                         region_size = value;
 618                 } else if (!strcasecmp(key, "raid10_copies") &&
 619                            (rs->raid_type->level == 10)) {
 620                         if ((value < 2) || (value > 0xFF)) {
 621                                 rs->ti->error = "Bad value for 'raid10_copies'";
 622                                 return -EINVAL;
 623                         }
 624                         rs->print_flags |= DMPF_RAID10_COPIES;
 625                         raid10_copies = value;
 626                 } else {
 627                         DMERR("Unable to parse RAID parameter: %s", key);
 628                         rs->ti->error = "Unable to parse RAID parameters";
 629                         return -EINVAL;
 630                 }
 631         }
 632
 633         if (validate_region_size(rs, region_size))
 634                 return -EINVAL;
 635
 636         if (rs->md.chunk_sectors)
 637                 max_io_len = rs->md.chunk_sectors;
 638         else
 639                 max_io_len = region_size;
 640
 641         if (dm_set_target_max_io_len(rs->ti, max_io_len))
 642                 return -EINVAL;
 643
 644         if (rs->raid_type->level == 10) {
 645                 if (raid10_copies > rs->md.raid_disks) {
 646                         rs->ti->error = "Not enough devices to satisfy specification";
 647                         return -EINVAL;
 648                 }
 649
 650                 /* (Len * #mirrors) / #devices */
 651                 sectors_per_dev = rs->ti->len * raid10_copies;
 652                 sector_div(sectors_per_dev, rs->md.raid_disks);
 653
 654                 rs->md.layout = raid10_format_to_md_layout(raid10_format,
 655                                                            raid10_copies);
 656                 rs->md.new_layout = rs->md.layout;
 657         } else if ((rs->raid_type->level > 1) &&
 658                    sector_div(sectors_per_dev,
 659                               (rs->md.raid_disks - rs->raid_type->parity_devs))) {
 660                 rs->ti->error = "Target length not divisible by number of data devices";
 661                 return -EINVAL;
 662         }
 663         rs->md.dev_sectors = sectors_per_dev;
 664
 665         if (validate_rebuild_devices(rs))
 666                 return -EINVAL;
 667
 668         /* Assume there are no metadata devices until the drives are parsed */
 669         rs->md.persistent = 0;
 670         rs->md.external = 1;
 671
 672         return 0;
 673 }
 674
 675 static void do_table_event(struct work_struct *ws)
 676 {
 677         struct raid_set *rs = container_of(ws, struct raid_set, md.event_work);
 678
 679         dm_table_event(rs->ti->table);
 680 }
 681
 682 static int raid_is_congested(struct dm_target_callbacks *cb, int bits)
 683 {
 684         struct raid_set *rs = container_of(cb, struct raid_set, callbacks);
 685
 686         if (rs->raid_type->level == 1)
 687                 return md_raid1_congested(&rs->md, bits);
 688
 689         if (rs->raid_type->level == 10)
 690                 return md_raid10_congested(&rs->md, bits);
 691
 692         return md_raid5_congested(&rs->md, bits);
 693 }
 694
 695 /*
 696  * This structure is never routinely used by userspace, unlike md superblocks.
 697  * Devices with this superblock should only ever be accessed via device-mapper.
 698  */
 699 #define DM_RAID_MAGIC 0x64526D44
 700 struct dm_raid_superblock {
 701         __le32 magic;           /* "DmRd" */
 702         __le32 features;        /* Used to indicate possible future changes */
 703
 704         __le32 num_devices;     /* Number of devices in this array. (Max 64) */
 705         __le32 array_position;  /* The position of this drive in the array */
 706
 707         __le64 events;          /* Incremented by md when superblock updated */
 708         __le64 failed_devices;  /* Bit field of devices to indicate failures */
 709
 710         /*
 711          * This offset tracks the progress of the repair or replacement of
 712          * an individual drive.
 713          */
 714         __le64 disk_recovery_offset;
 715
 716         /*
 717          * This offset tracks the progress of the initial array
 718          * synchronisation/parity calculation.
 719          */
 720         __le64 array_resync_offset;
 721
 722         /*
 723          * RAID characteristics
 724          */
 725         __le32 level;
 726         __le32 layout;
 727         __le32 stripe_sectors;
 728
 729         __u8 pad[452];          /* Round struct to 512 bytes. */
 730                                 /* Always set to 0 when writing. */
 731 } __packed;
 732
 733 static int read_disk_sb(struct md_rdev *rdev, int size)
 734 {
 735         BUG_ON(!rdev->sb_page);
 736
 737         if (rdev->sb_loaded)
 738                 return 0;
 739
 740         if (!sync_page_io(rdev, 0, size, rdev->sb_page, READ, 1)) {
 741                 DMERR("Failed to read superblock of device at position %d",
 742                       rdev->raid_disk);
 743                 md_error(rdev->mddev, rdev);
 744                 return -EINVAL;
 745         }
 746
 747         rdev->sb_loaded = 1;
 748
 749         return 0;
 750 }
 751
 752 static void super_sync(struct mddev *mddev, struct md_rdev *rdev)
 753 {
 754         int i;
 755         uint64_t failed_devices;
 756         struct dm_raid_superblock *sb;
 757         struct raid_set *rs = container_of(mddev, struct raid_set, md);
 758
 759         sb = page_address(rdev->sb_page);
 760         failed_devices = le64_to_cpu(sb->failed_devices);
 761
 762         for (i = 0; i < mddev->raid_disks; i++)
 763                 if (!rs->dev[i].data_dev ||
 764                     test_bit(Faulty, &(rs->dev[i].rdev.flags)))
 765                         failed_devices |= (1ULL << i);
 766
 767         memset(sb, 0, sizeof(*sb));
 768
 769         sb->magic = cpu_to_le32(DM_RAID_MAGIC);
 770         sb->features = cpu_to_le32(0);  /* No features yet */
 771
 772         sb->num_devices = cpu_to_le32(mddev->raid_disks);
 773         sb->array_position = cpu_to_le32(rdev->raid_disk);
 774
 775         sb->events = cpu_to_le64(mddev->events);
 776         sb->failed_devices = cpu_to_le64(failed_devices);
 777
 778         sb->disk_recovery_offset = cpu_to_le64(rdev->recovery_offset);
 779         sb->array_resync_offset = cpu_to_le64(mddev->recovery_cp);
 780
 781         sb->level = cpu_to_le32(mddev->level);
 782         sb->layout = cpu_to_le32(mddev->layout);
 783         sb->stripe_sectors = cpu_to_le32(mddev->chunk_sectors);
 784 }
 785
 786 /*
 787  * super_load
 788  *
 789  * This function creates a superblock if one is not found on the device
 790  * and will decide which superblock to use if there's a choice.
 791  *
 792  * Return: 1 if use rdev, 0 if use refdev, -Exxx otherwise
 793  */
 794 static int super_load(struct md_rdev *rdev, struct md_rdev *refdev)
 795 {
 796         int ret;
 797         struct dm_raid_superblock *sb;
 798         struct dm_raid_superblock *refsb;
 799         uint64_t events_sb, events_refsb;
 800
 801         rdev->sb_start = 0;
 802         rdev->sb_size = sizeof(*sb);
 803
 804         ret = read_disk_sb(rdev, rdev->sb_size);
 805         if (ret)
 806                 return ret;
 807
 808         sb = page_address(rdev->sb_page);
 809
 810         /*
 811          * Two cases that we want to write new superblocks and rebuild:
 812          * 1) New device (no matching magic number)
 813          * 2) Device specified for rebuild (!In_sync w/ offset == 0)
 814          */
 815         if ((sb->magic != cpu_to_le32(DM_RAID_MAGIC)) ||
 816             (!test_bit(In_sync, &rdev->flags) && !rdev->recovery_offset)) {
 817                 super_sync(rdev->mddev, rdev);
 818
 819                 set_bit(FirstUse, &rdev->flags);
 820
 821                 /* Force writing of superblocks to disk */
 822                 set_bit(MD_CHANGE_DEVS, &rdev->mddev->flags);
 823
 824                 /* Any superblock is better than none, choose that if given */
 825                 return refdev ? 0 : 1;
 826         }
 827
 828         if (!refdev)
 829                 return 1;
 830
 831         events_sb = le64_to_cpu(sb->events);
 832
 833         refsb = page_address(refdev->sb_page);
 834         events_refsb = le64_to_cpu(refsb->events);
 835
 836         return (events_sb > events_refsb) ? 1 : 0;
 837 }
 838
 839 static int super_init_validation(struct mddev *mddev, struct md_rdev *rdev)
 840 {
 841         int role;
 842         struct raid_set *rs = container_of(mddev, struct raid_set, md);
 843         uint64_t events_sb;
 844         uint64_t failed_devices;
 845         struct dm_raid_superblock *sb;
 846         uint32_t new_devs = 0;
 847         uint32_t rebuilds = 0;
 848         struct md_rdev *r;
 849         struct dm_raid_superblock *sb2;
 850
 851         sb = page_address(rdev->sb_page);
 852         events_sb = le64_to_cpu(sb->events);
 853         failed_devices = le64_to_cpu(sb->failed_devices);
 854
 855         /*
 856          * Initialise to 1 if this is a new superblock.
 857          */
 858         mddev->events = events_sb ? : 1;
 859
 860         /*
 861          * Reshaping is not currently allowed
 862          */
 863         if ((le32_to_cpu(sb->level) != mddev->level) ||
 864             (le32_to_cpu(sb->layout) != mddev->layout) ||
 865             (le32_to_cpu(sb->stripe_sectors) != mddev->chunk_sectors)) {
 866                 DMERR("Reshaping arrays not yet supported.");
 867                 return -EINVAL;
 868         }
 869
 870         /* We can only change the number of devices in RAID1 right now */
 871         if ((rs->raid_type->level != 1) &&
 872             (le32_to_cpu(sb->num_devices) != mddev->raid_disks)) {
 873                 DMERR("Reshaping arrays not yet supported.");
 874                 return -EINVAL;
 875         }
 876
 877         if (!(rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC)))
 878                 mddev->recovery_cp = le64_to_cpu(sb->array_resync_offset);
 879
 880         /*
 881          * During load, we set FirstUse if a new superblock was written.
 882          * There are two reasons we might not have a superblock:
 883          * 1) The array is brand new - in which case, all of the
 884          *    devices must have their In_sync bit set.  Also,
 885          *    recovery_cp must be 0, unless forced.
 886          * 2) This is a new device being added to an old array
 887          *    and the new device needs to be rebuilt - in which
 888          *    case the In_sync bit will /not/ be set and
 889          *    recovery_cp must be MaxSector.
 890          */
 891         rdev_for_each(r, mddev) {
 892                 if (!test_bit(In_sync, &r->flags)) {
 893                         DMINFO("Device %d specified for rebuild: "
 894                                "Clearing superblock", r->raid_disk);
 895                         rebuilds++;
 896                 } else if (test_bit(FirstUse, &r->flags))
 897                         new_devs++;
 898         }
 899
 900         if (!rebuilds) {
 901                 if (new_devs == mddev->raid_disks) {
 902                         DMINFO("Superblocks created for new array");
 903                         set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
 904                 } else if (new_devs) {
 905                         DMERR("New device injected "
 906                               "into existing array without 'rebuild' "
 907                               "parameter specified");
 908                         return -EINVAL;
 909                 }
 910         } else if (new_devs) {
 911                 DMERR("'rebuild' devices cannot be "
 912                       "injected into an array with other first-time devices");
 913                 return -EINVAL;
 914         } else if (mddev->recovery_cp != MaxSector) {
 915                 DMERR("'rebuild' specified while array is not in-sync");
 916                 return -EINVAL;
 917         }
 918
 919         /*
 920          * Now we set the Faulty bit for those devices that are
 921          * recorded in the superblock as failed.
 922          */
 923         rdev_for_each(r, mddev) {
 924                 if (!r->sb_page)
 925                         continue;
 926                 sb2 = page_address(r->sb_page);
 927                 sb2->failed_devices = 0;
 928
 929                 /*
 930                  * Check for any device re-ordering.
 931                  */
 932                 if (!test_bit(FirstUse, &r->flags) && (r->raid_disk >= 0)) {
 933                         role = le32_to_cpu(sb2->array_position);
 934                         if (role != r->raid_disk) {
 935                                 if (rs->raid_type->level != 1) {
 936                                         rs->ti->error = "Cannot change device "
 937                                                 "positions in RAID array";
 938                                         return -EINVAL;
 939                                 }
 940                                 DMINFO("RAID1 device #%d now at position #%d",
 941                                        role, r->raid_disk);
 942                         }
 943
 944                         /*
 945                          * Partial recovery is performed on
 946                          * returning failed devices.
 947                          */
 948                         if (failed_devices & (1 << role))
 949                                 set_bit(Faulty, &r->flags);
 950                 }
 951         }
 952
 953         return 0;
 954 }
 955
 956 static int super_validate(struct mddev *mddev, struct md_rdev *rdev)
 957 {
 958         struct dm_raid_superblock *sb = page_address(rdev->sb_page);
 959
 960         /*
 961          * If mddev->events is not set, we know we have not yet initialized
 962          * the array.
 963          */
 964         if (!mddev->events && super_init_validation(mddev, rdev))
 965                 return -EINVAL;
 966
 967         mddev->bitmap_info.offset = 4096 >> 9; /* Enable bitmap creation */
 968         rdev->mddev->bitmap_info.default_offset = 4096 >> 9;
 969         if (!test_bit(FirstUse, &rdev->flags)) {
 970                 rdev->recovery_offset = le64_to_cpu(sb->disk_recovery_offset);
 971                 if (rdev->recovery_offset != MaxSector)
 972                         clear_bit(In_sync, &rdev->flags);
 973         }
 974
 975         /*
 976          * If a device comes back, set it as not In_sync and no longer faulty.
 977          */
 978         if (test_bit(Faulty, &rdev->flags)) {
 979                 clear_bit(Faulty, &rdev->flags);
 980                 clear_bit(In_sync, &rdev->flags);
 981                 rdev->saved_raid_disk = rdev->raid_disk;
 982                 rdev->recovery_offset = 0;
 983         }
 984
 985         clear_bit(FirstUse, &rdev->flags);
 986
 987         return 0;
 988 }
 989
 990 /*
 991  * Analyse superblocks and select the freshest.
 992  */
 993 static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
 994 {
 995         int ret;
 996         unsigned redundancy = 0;
 997         struct raid_dev *dev;
 998         struct md_rdev *rdev, *tmp, *freshest;
 999         struct mddev *mddev = &rs->md;
1000
1001         switch (rs->raid_type->level) {
1002         case 1:
1003                 redundancy = rs->md.raid_disks - 1;
1004                 break;
1005         case 4:
1006         case 5:
1007         case 6:
1008                 redundancy = rs->raid_type->parity_devs;
1009                 break;
1010         case 10:
1011                 redundancy = raid10_md_layout_to_copies(mddev->layout) - 1;
1012                 break;
1013         default:
1014                 ti->error = "Unknown RAID type";
1015                 return -EINVAL;
1016         }
1017
1018         freshest = NULL;
1019         rdev_for_each_safe(rdev, tmp, mddev) {
1020                 /*
1021                  * Skipping super_load due to DMPF_SYNC will cause
1022                  * the array to undergo initialization again as
1023                  * though it were new.  This is the intended effect
1024                  * of the "sync" directive.
1025                  *
1026                  * When reshaping capability is added, we must ensure
1027                  * that the "sync" directive is disallowed during the
1028                  * reshape.
1029                  */
1030                 if (rs->print_flags & DMPF_SYNC)
1031                         continue;
1032
1033                 if (!rdev->meta_bdev)
1034                         continue;
1035
1036                 ret = super_load(rdev, freshest);
1037
1038                 switch (ret) {
1039                 case 1:
1040                         freshest = rdev;
1041                         break;
1042                 case 0:
1043                         break;
1044                 default:
1045                         dev = container_of(rdev, struct raid_dev, rdev);
1046                         if (redundancy--) {
1047                                 if (dev->meta_dev)
1048                                         dm_put_device(ti, dev->meta_dev);
1049
1050                                 dev->meta_dev = NULL;
1051                                 rdev->meta_bdev = NULL;
1052
1053                                 if (rdev->sb_page)
1054                                         put_page(rdev->sb_page);
1055
1056                                 rdev->sb_page = NULL;
1057
1058                                 rdev->sb_loaded = 0;
1059
1060                                 /*
1061                                  * We might be able to salvage the data device
1062                                  * even though the meta device has failed.  For
1063                                  * now, we behave as though '- -' had been
1064                                  * set for this device in the table.
1065                                  */
1066                                 if (dev->data_dev)
1067                                         dm_put_device(ti, dev->data_dev);
1068
1069                                 dev->data_dev = NULL;
1070                                 rdev->bdev = NULL;
1071
1072                                 list_del(&rdev->same_set);
1073
1074                                 continue;
1075                         }
1076                         ti->error = "Failed to load superblock";
1077                         return ret;
1078                 }
1079         }
1080
1081         if (!freshest)
1082                 return 0;
1083
1084         /*
1085          * Validation of the freshest device provides the source of
1086          * validation for the remaining devices.
1087          */
1088         ti->error = "Unable to assemble array: Invalid superblocks";
1089         if (super_validate(mddev, freshest))
1090                 return -EINVAL;
1091
1092         rdev_for_each(rdev, mddev)
1093                 if ((rdev != freshest) && super_validate(mddev, rdev))
1094                         return -EINVAL;
1095
1096         return 0;
1097 }
1098
1099 /*
1100  * Construct a RAID4/5/6 mapping:
1101  * Args:
1102  *      <raid_type> <#raid_params> <raid_params>                \
1103  *      <#raid_devs> { <meta_dev1> <dev1> .. <meta_devN> <devN> }
1104  *
1105  * <raid_params> varies by <raid_type>.  See 'parse_raid_params' for
1106  * details on possible <raid_params>.
1107  */
1108 static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
1109 {
1110         int ret;
1111         struct raid_type *rt;
1112         unsigned long num_raid_params, num_raid_devs;
1113         struct raid_set *rs = NULL;
1114
1115         /* Must have at least <raid_type> <#raid_params> */
1116         if (argc < 2) {
1117                 ti->error = "Too few arguments";
1118                 return -EINVAL;
1119         }
1120
1121         /* raid type */
1122         rt = get_raid_type(argv[0]);
1123         if (!rt) {
1124                 ti->error = "Unrecognised raid_type";
1125                 return -EINVAL;
1126         }
1127         argc--;
1128         argv++;
1129
1130         /* number of RAID parameters */
1131         if (strict_strtoul(argv[0], 10, &num_raid_params) < 0) {
1132                 ti->error = "Cannot understand number of RAID parameters";
1133                 return -EINVAL;
1134         }
1135         argc--;
1136         argv++;
1137
1138         /* Skip over RAID params for now and find out # of devices */
1139         if (num_raid_params + 1 > argc) {
1140                 ti->error = "Arguments do not agree with counts given";
1141                 return -EINVAL;
1142         }
1143
1144         if ((strict_strtoul(argv[num_raid_params], 10, &num_raid_devs) < 0) ||
1145             (num_raid_devs >= INT_MAX)) {
1146                 ti->error = "Cannot understand number of raid devices";
1147                 return -EINVAL;
1148         }
1149
1150         rs = context_alloc(ti, rt, (unsigned)num_raid_devs);
1151         if (IS_ERR(rs))
1152                 return PTR_ERR(rs);
1153
1154         ret = parse_raid_params(rs, argv, (unsigned)num_raid_params);
1155         if (ret)
1156                 goto bad;
1157
1158         ret = -EINVAL;
1159
1160         argc -= num_raid_params + 1; /* +1: we already have num_raid_devs */
1161         argv += num_raid_params + 1;
1162
1163         if (argc != (num_raid_devs * 2)) {
1164                 ti->error = "Supplied RAID devices does not match the count given";
1165                 goto bad;
1166         }
1167
1168         ret = dev_parms(rs, argv);
1169         if (ret)
1170                 goto bad;
1171
1172         rs->md.sync_super = super_sync;
1173         ret = analyse_superblocks(ti, rs);
1174         if (ret)
1175                 goto bad;
1176
1177         INIT_WORK(&rs->md.event_work, do_table_event);
1178         ti->private = rs;
1179         ti->num_flush_requests = 1;
1180
1181         mutex_lock(&rs->md.reconfig_mutex);
1182         ret = md_run(&rs->md);
1183         rs->md.in_sync = 0; /* Assume already marked dirty */
1184         mutex_unlock(&rs->md.reconfig_mutex);
1185
1186         if (ret) {
1187                 ti->error = "Fail to run raid array";
1188                 goto bad;
1189         }
1190
1191         if (ti->len != rs->md.array_sectors) {
1192                 ti->error = "Array size does not match requested target length";
1193                 ret = -EINVAL;
1194                 goto size_mismatch;
1195         }
1196         rs->callbacks.congested_fn = raid_is_congested;
1197         dm_table_add_target_callbacks(ti->table, &rs->callbacks);
1198
1199         mddev_suspend(&rs->md);
1200         return 0;
1201
1202 size_mismatch:
1203         md_stop(&rs->md);
1204 bad:
1205         context_free(rs);
1206
1207         return ret;
1208 }
1209
1210 static void raid_dtr(struct dm_target *ti)
1211 {
1212         struct raid_set *rs = ti->private;
1213
1214         list_del_init(&rs->callbacks.list);
1215         md_stop(&rs->md);
1216         context_free(rs);
1217 }
1218
1219 static int raid_map(struct dm_target *ti, struct bio *bio, union map_info *map_context)
1220 {
1221         struct raid_set *rs = ti->private;
1222         struct mddev *mddev = &rs->md;
1223
1224         mddev->pers->make_request(mddev, bio);
1225
1226         return DM_MAPIO_SUBMITTED;
1227 }
1228
1229 static int raid_status(struct dm_target *ti, status_type_t type,
1230                        unsigned status_flags, char *result, unsigned maxlen)
1231 {
1232         struct raid_set *rs = ti->private;
1233         unsigned raid_param_cnt = 1; /* at least 1 for chunksize */
1234         unsigned sz = 0;
1235         int i, array_in_sync = 0;
1236         sector_t sync;
1237
1238         switch (type) {
1239         case STATUSTYPE_INFO:
1240                 DMEMIT("%s %d ", rs->raid_type->name, rs->md.raid_disks);
1241
1242                 if (test_bit(MD_RECOVERY_RUNNING, &rs->md.recovery))
1243                         sync = rs->md.curr_resync_completed;
1244                 else
1245                         sync = rs->md.recovery_cp;
1246
1247                 if (sync >= rs->md.resync_max_sectors) {
1248                         array_in_sync = 1;
1249                         sync = rs->md.resync_max_sectors;
1250                 } else {
1251                         /*
1252                          * The array may be doing an initial sync, or it may
1253                          * be rebuilding individual components.  If all the
1254                          * devices are In_sync, then it is the array that is
1255                          * being initialized.
1256                          */
1257                         for (i = 0; i < rs->md.raid_disks; i++)
1258                                 if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
1259                                         array_in_sync = 1;
1260                 }
1261                 /*
1262                  * Status characters:
1263                  *  'D' = Dead/Failed device
1264                  *  'a' = Alive but not in-sync
1265                  *  'A' = Alive and in-sync
1266                  */
1267                 for (i = 0; i < rs->md.raid_disks; i++) {
1268                         if (test_bit(Faulty, &rs->dev[i].rdev.flags))
1269                                 DMEMIT("D");
1270                         else if (!array_in_sync ||
1271                                  !test_bit(In_sync, &rs->dev[i].rdev.flags))
1272                                 DMEMIT("a");
1273                         else
1274                                 DMEMIT("A");
1275                 }
1276
1277                 /*
1278                  * In-sync ratio:
1279                  *  The in-sync ratio shows the progress of:
1280                  *   - Initializing the array
1281                  *   - Rebuilding a subset of devices of the array
1282                  *  The user can distinguish between the two by referring
1283                  *  to the status characters.
1284                  */
1285                 DMEMIT(" %llu/%llu",
1286                        (unsigned long long) sync,
1287                        (unsigned long long) rs->md.resync_max_sectors);
1288
1289                 break;
1290         case STATUSTYPE_TABLE:
1291                 /* The string you would use to construct this array */
1292                 for (i = 0; i < rs->md.raid_disks; i++) {
1293                         if ((rs->print_flags & DMPF_REBUILD) &&
1294                             rs->dev[i].data_dev &&
1295                             !test_bit(In_sync, &rs->dev[i].rdev.flags))
1296                                 raid_param_cnt += 2; /* for rebuilds */
1297                         if (rs->dev[i].data_dev &&
1298                             test_bit(WriteMostly, &rs->dev[i].rdev.flags))
1299                                 raid_param_cnt += 2;
1300                 }
1301
1302                 raid_param_cnt += (hweight32(rs->print_flags & ~DMPF_REBUILD) * 2);
1303                 if (rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC))
1304                         raid_param_cnt--;
1305
1306                 DMEMIT("%s %u %u", rs->raid_type->name,
1307                        raid_param_cnt, rs->md.chunk_sectors);
1308
1309                 if ((rs->print_flags & DMPF_SYNC) &&
1310                     (rs->md.recovery_cp == MaxSector))
1311                         DMEMIT(" sync");
1312                 if (rs->print_flags & DMPF_NOSYNC)
1313                         DMEMIT(" nosync");
1314
1315                 for (i = 0; i < rs->md.raid_disks; i++)
1316                         if ((rs->print_flags & DMPF_REBUILD) &&
1317                             rs->dev[i].data_dev &&
1318                             !test_bit(In_sync, &rs->dev[i].rdev.flags))
1319                                 DMEMIT(" rebuild %u", i);
1320
1321                 if (rs->print_flags & DMPF_DAEMON_SLEEP)
1322                         DMEMIT(" daemon_sleep %lu",
1323                                rs->md.bitmap_info.daemon_sleep);
1324
1325                 if (rs->print_flags & DMPF_MIN_RECOVERY_RATE)
1326                         DMEMIT(" min_recovery_rate %d", rs->md.sync_speed_min);
1327
1328                 if (rs->print_flags & DMPF_MAX_RECOVERY_RATE)
1329                         DMEMIT(" max_recovery_rate %d", rs->md.sync_speed_max);
1330
1331                 for (i = 0; i < rs->md.raid_disks; i++)
1332                         if (rs->dev[i].data_dev &&
1333                             test_bit(WriteMostly, &rs->dev[i].rdev.flags))
1334                                 DMEMIT(" write_mostly %u", i);
1335
1336                 if (rs->print_flags & DMPF_MAX_WRITE_BEHIND)
1337                         DMEMIT(" max_write_behind %lu",
1338                                rs->md.bitmap_info.max_write_behind);
1339
1340                 if (rs->print_flags & DMPF_STRIPE_CACHE) {
1341                         struct r5conf *conf = rs->md.private;
1342
1343                         /* convert from kiB to sectors */
1344                         DMEMIT(" stripe_cache %d",
1345                                conf ? conf->max_nr_stripes * 2 : 0);
1346                 }
1347
1348                 if (rs->print_flags & DMPF_REGION_SIZE)
1349                         DMEMIT(" region_size %lu",
1350                                rs->md.bitmap_info.chunksize >> 9);
1351
1352                 if (rs->print_flags & DMPF_RAID10_COPIES)
1353                         DMEMIT(" raid10_copies %u",
1354                                raid10_md_layout_to_copies(rs->md.layout));
1355
1356                 if (rs->print_flags & DMPF_RAID10_FORMAT)
1357                         DMEMIT(" raid10_format near");
1358
1359                 DMEMIT(" %d", rs->md.raid_disks);
1360                 for (i = 0; i < rs->md.raid_disks; i++) {
1361                         if (rs->dev[i].meta_dev)
1362                                 DMEMIT(" %s", rs->dev[i].meta_dev->name);
1363                         else
1364                                 DMEMIT(" -");
1365
1366                         if (rs->dev[i].data_dev)
1367                                 DMEMIT(" %s", rs->dev[i].data_dev->name);
1368                         else
1369                                 DMEMIT(" -");
1370                 }
1371         }
1372
1373         return 0;
1374 }
1375
1376 static int raid_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data)
1377 {
1378         struct raid_set *rs = ti->private;
1379         unsigned i;
1380         int ret = 0;
1381
1382         for (i = 0; !ret && i < rs->md.raid_disks; i++)
1383                 if (rs->dev[i].data_dev)
1384                         ret = fn(ti,
1385                                  rs->dev[i].data_dev,
1386                                  0, /* No offset on data devs */
1387                                  rs->md.dev_sectors,
1388                                  data);
1389
1390         return ret;
1391 }
1392
1393 static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
1394 {
1395         struct raid_set *rs = ti->private;
1396         unsigned chunk_size = rs->md.chunk_sectors << 9;
1397         struct r5conf *conf = rs->md.private;
1398
1399         blk_limits_io_min(limits, chunk_size);
1400         blk_limits_io_opt(limits, chunk_size * (conf->raid_disks - conf->max_degraded));
1401 }
1402
1403 static void raid_presuspend(struct dm_target *ti)
1404 {
1405         struct raid_set *rs = ti->private;
1406
1407         md_stop_writes(&rs->md);
1408 }
1409
1410 static void raid_postsuspend(struct dm_target *ti)
1411 {
1412         struct raid_set *rs = ti->private;
1413
1414         mddev_suspend(&rs->md);
1415 }
1416
1417 static void raid_resume(struct dm_target *ti)
1418 {
1419         struct raid_set *rs = ti->private;
1420
1421         set_bit(MD_CHANGE_DEVS, &rs->md.flags);
1422         if (!rs->bitmap_loaded) {
1423                 bitmap_load(&rs->md);
1424                 rs->bitmap_loaded = 1;
1425         }
1426
1427         clear_bit(MD_RECOVERY_FROZEN, &rs->md.recovery);
1428         mddev_resume(&rs->md);
1429 }
1430
1431 static struct target_type raid_target = {
1432         .name = "raid",
1433         .version = {1, 3, 1},
1434         .module = THIS_MODULE,
1435         .ctr = raid_ctr,
1436         .dtr = raid_dtr,
1437         .map = raid_map,
1438         .status = raid_status,
1439         .iterate_devices = raid_iterate_devices,
1440         .io_hints = raid_io_hints,
1441         .presuspend = raid_presuspend,
1442         .postsuspend = raid_postsuspend,
1443         .resume = raid_resume,
1444 };
1445
1446 static int __init dm_raid_init(void)
1447 {
1448         return dm_register_target(&raid_target);
1449 }
1450
1451 static void __exit dm_raid_exit(void)
1452 {
1453         dm_unregister_target(&raid_target);
1454 }
1455
1456 module_init(dm_raid_init);
1457 module_exit(dm_raid_exit);
1458
1459 MODULE_DESCRIPTION(DM_NAME " raid4/5/6 target");
1460 MODULE_ALIAS("dm-raid1");
1461 MODULE_ALIAS("dm-raid10");
1462 MODULE_ALIAS("dm-raid4");
1463 MODULE_ALIAS("dm-raid5");
1464 MODULE_ALIAS("dm-raid6");
1465 MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>");
1466 MODULE_LICENSE("GPL");