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                         /* If not a power of 2, make it the next power of 2 */
 299                         if (min_region_size & (min_region_size - 1))
 300                                 region_size = 1 << fls(region_size);
 301                         DMINFO("Choosing default region size of %lu sectors",
 302                                region_size);
 303                 } else {
 304                         DMINFO("Choosing default region size of 4MiB");
 305                         region_size = 1 << 13; /* sectors */
 306                 }
 307         } else {
 308                 /*
 309                  * Validate user-supplied value.
 310                  */
 311                 if (region_size > rs->ti->len) {
 312                         rs->ti->error = "Supplied region size is too large";
 313                         return -EINVAL;
 314                 }
 315
 316                 if (region_size < min_region_size) {
 317                         DMERR("Supplied region_size (%lu sectors) below minimum (%lu)",
 318                               region_size, min_region_size);
 319                         rs->ti->error = "Supplied region size is too small";
 320                         return -EINVAL;
 321                 }
 322
 323                 if (!is_power_of_2(region_size)) {
 324                         rs->ti->error = "Region size is not a power of 2";
 325                         return -EINVAL;
 326                 }
 327
 328                 if (region_size < rs->md.chunk_sectors) {
 329                         rs->ti->error = "Region size is smaller than the chunk size";
 330                         return -EINVAL;
 331                 }
 332         }
 333
 334         /*
 335          * Convert sectors to bytes.
 336          */
 337         rs->md.bitmap_info.chunksize = (region_size << 9);
 338
 339         return 0;
 340 }
 341
 342 /*
 343  * validate_raid_redundancy
 344  * @rs
 345  *
 346  * Determine if there are enough devices in the array that haven't
 347  * failed (or are being rebuilt) to form a usable array.
 348  *
 349  * Returns: 0 on success, -EINVAL on failure.
 350  */
 351 static int validate_raid_redundancy(struct raid_set *rs)
 352 {
 353         unsigned i, rebuild_cnt = 0;
 354         unsigned rebuilds_per_group, copies, d;
 355
 356         for (i = 0; i < rs->md.raid_disks; i++)
 357                 if (!test_bit(In_sync, &rs->dev[i].rdev.flags) ||
 358                     !rs->dev[i].rdev.sb_page)
 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                 for (i = 0; i < rs->md.raid_disks * copies; i++) {
 395                         if (!(i % copies))
 396                                 rebuilds_per_group = 0;
 397                         d = i % rs->md.raid_disks;
 398                         if ((!rs->dev[d].rdev.sb_page ||
 399                              !test_bit(In_sync, &rs->dev[d].rdev.flags)) &&
 400                             (++rebuilds_per_group >= copies))
 401                                 goto too_many;
 402                 }
 403                 break;
 404         default:
 405                 if (rebuild_cnt)
 406                         return -EINVAL;
 407         }
 408
 409         return 0;
 410
 411 too_many:
 412         return -EINVAL;
 413 }
 414
 415 /*
 416  * Possible arguments are...
 417  *      <chunk_size> [optional_args]
 418  *
 419  * Argument definitions
 420  *    <chunk_size>                      The number of sectors per disk that
 421  *                                      will form the "stripe"
 422  *    [[no]sync]                        Force or prevent recovery of the
 423  *                                      entire array
 424  *    [rebuild <idx>]                   Rebuild the drive indicated by the index
 425  *    [daemon_sleep <ms>]               Time between bitmap daemon work to
 426  *                                      clear bits
 427  *    [min_recovery_rate <kB/sec/disk>] Throttle RAID initialization
 428  *    [max_recovery_rate <kB/sec/disk>] Throttle RAID initialization
 429  *    [write_mostly <idx>]              Indicate a write mostly drive via index
 430  *    [max_write_behind <sectors>]      See '-write-behind=' (man mdadm)
 431  *    [stripe_cache <sectors>]          Stripe cache size for higher RAIDs
 432  *    [region_size <sectors>]           Defines granularity of bitmap
 433  *
 434  * RAID10-only options:
 435  *    [raid10_copies <# copies>]        Number of copies.  (Default: 2)
 436  *    [raid10_format <near>]            Layout algorithm.  (Default: near)
 437  */
 438 static int parse_raid_params(struct raid_set *rs, char **argv,
 439                              unsigned num_raid_params)
 440 {
 441         char *raid10_format = "near";
 442         unsigned raid10_copies = 2;
 443         unsigned i;
 444         unsigned long value, region_size = 0;
 445         sector_t sectors_per_dev = rs->ti->len;
 446         sector_t max_io_len;
 447         char *key;
 448
 449         /*
 450          * First, parse the in-order required arguments
 451          * "chunk_size" is the only argument of this type.
 452          */
 453         if ((strict_strtoul(argv[0], 10, &value) < 0)) {
 454                 rs->ti->error = "Bad chunk size";
 455                 return -EINVAL;
 456         } else if (rs->raid_type->level == 1) {
 457                 if (value)
 458                         DMERR("Ignoring chunk size parameter for RAID 1");
 459                 value = 0;
 460         } else if (!is_power_of_2(value)) {
 461                 rs->ti->error = "Chunk size must be a power of 2";
 462                 return -EINVAL;
 463         } else if (value < 8) {
 464                 rs->ti->error = "Chunk size value is too small";
 465                 return -EINVAL;
 466         }
 467
 468         rs->md.new_chunk_sectors = rs->md.chunk_sectors = value;
 469         argv++;
 470         num_raid_params--;
 471
 472         /*
 473          * We set each individual device as In_sync with a completed
 474          * 'recovery_offset'.  If there has been a device failure or
 475          * replacement then one of the following cases applies:
 476          *
 477          *   1) User specifies 'rebuild'.
 478          *      - Device is reset when param is read.
 479          *   2) A new device is supplied.
 480          *      - No matching superblock found, resets device.
 481          *   3) Device failure was transient and returns on reload.
 482          *      - Failure noticed, resets device for bitmap replay.
 483          *   4) Device hadn't completed recovery after previous failure.
 484          *      - Superblock is read and overrides recovery_offset.
 485          *
 486          * What is found in the superblocks of the devices is always
 487          * authoritative, unless 'rebuild' or '[no]sync' was specified.
 488          */
 489         for (i = 0; i < rs->md.raid_disks; i++) {
 490                 set_bit(In_sync, &rs->dev[i].rdev.flags);
 491                 rs->dev[i].rdev.recovery_offset = MaxSector;
 492         }
 493
 494         /*
 495          * Second, parse the unordered optional arguments
 496          */
 497         for (i = 0; i < num_raid_params; i++) {
 498                 if (!strcasecmp(argv[i], "nosync")) {
 499                         rs->md.recovery_cp = MaxSector;
 500                         rs->print_flags |= DMPF_NOSYNC;
 501                         continue;
 502                 }
 503                 if (!strcasecmp(argv[i], "sync")) {
 504                         rs->md.recovery_cp = 0;
 505                         rs->print_flags |= DMPF_SYNC;
 506                         continue;
 507                 }
 508
 509                 /* The rest of the optional arguments come in key/value pairs */
 510                 if ((i + 1) >= num_raid_params) {
 511                         rs->ti->error = "Wrong number of raid parameters given";
 512                         return -EINVAL;
 513                 }
 514
 515                 key = argv[i++];
 516
 517                 /* Parameters that take a string value are checked here. */
 518                 if (!strcasecmp(key, "raid10_format")) {
 519                         if (rs->raid_type->level != 10) {
 520                                 rs->ti->error = "'raid10_format' is an invalid parameter for this RAID type";
 521                                 return -EINVAL;
 522                         }
 523                         if (strcmp("near", argv[i])) {
 524                                 rs->ti->error = "Invalid 'raid10_format' value given";
 525                                 return -EINVAL;
 526                         }
 527                         raid10_format = argv[i];
 528                         rs->print_flags |= DMPF_RAID10_FORMAT;
 529                         continue;
 530                 }
 531
 532                 if (strict_strtoul(argv[i], 10, &value) < 0) {
 533                         rs->ti->error = "Bad numerical argument given in raid params";
 534                         return -EINVAL;
 535                 }
 536
 537                 /* Parameters that take a numeric value are checked here */
 538                 if (!strcasecmp(key, "rebuild")) {
 539                         if (value >= rs->md.raid_disks) {
 540                                 rs->ti->error = "Invalid rebuild index given";
 541                                 return -EINVAL;
 542                         }
 543                         clear_bit(In_sync, &rs->dev[value].rdev.flags);
 544                         rs->dev[value].rdev.recovery_offset = 0;
 545                         rs->print_flags |= DMPF_REBUILD;
 546                 } else if (!strcasecmp(key, "write_mostly")) {
 547                         if (rs->raid_type->level != 1) {
 548                                 rs->ti->error = "write_mostly option is only valid for RAID1";
 549                                 return -EINVAL;
 550                         }
 551                         if (value >= rs->md.raid_disks) {
 552                                 rs->ti->error = "Invalid write_mostly drive index given";
 553                                 return -EINVAL;
 554                         }
 555                         set_bit(WriteMostly, &rs->dev[value].rdev.flags);
 556                 } else if (!strcasecmp(key, "max_write_behind")) {
 557                         if (rs->raid_type->level != 1) {
 558                                 rs->ti->error = "max_write_behind option is only valid for RAID1";
 559                                 return -EINVAL;
 560                         }
 561                         rs->print_flags |= DMPF_MAX_WRITE_BEHIND;
 562
 563                         /*
 564                          * In device-mapper, we specify things in sectors, but
 565                          * MD records this value in kB
 566                          */
 567                         value /= 2;
 568                         if (value > COUNTER_MAX) {
 569                                 rs->ti->error = "Max write-behind limit out of range";
 570                                 return -EINVAL;
 571                         }
 572                         rs->md.bitmap_info.max_write_behind = value;
 573                 } else if (!strcasecmp(key, "daemon_sleep")) {
 574                         rs->print_flags |= DMPF_DAEMON_SLEEP;
 575                         if (!value || (value > MAX_SCHEDULE_TIMEOUT)) {
 576                                 rs->ti->error = "daemon sleep period out of range";
 577                                 return -EINVAL;
 578                         }
 579                         rs->md.bitmap_info.daemon_sleep = value;
 580                 } else if (!strcasecmp(key, "stripe_cache")) {
 581                         rs->print_flags |= DMPF_STRIPE_CACHE;
 582
 583                         /*
 584                          * In device-mapper, we specify things in sectors, but
 585                          * MD records this value in kB
 586                          */
 587                         value /= 2;
 588
 589                         if ((rs->raid_type->level != 5) &&
 590                             (rs->raid_type->level != 6)) {
 591                                 rs->ti->error = "Inappropriate argument: stripe_cache";
 592                                 return -EINVAL;
 593                         }
 594                         if (raid5_set_cache_size(&rs->md, (int)value)) {
 595                                 rs->ti->error = "Bad stripe_cache size";
 596                                 return -EINVAL;
 597                         }
 598                 } else if (!strcasecmp(key, "min_recovery_rate")) {
 599                         rs->print_flags |= DMPF_MIN_RECOVERY_RATE;
 600                         if (value > INT_MAX) {
 601                                 rs->ti->error = "min_recovery_rate out of range";
 602                                 return -EINVAL;
 603                         }
 604                         rs->md.sync_speed_min = (int)value;
 605                 } else if (!strcasecmp(key, "max_recovery_rate")) {
 606                         rs->print_flags |= DMPF_MAX_RECOVERY_RATE;
 607                         if (value > INT_MAX) {
 608                                 rs->ti->error = "max_recovery_rate out of range";
 609                                 return -EINVAL;
 610                         }
 611                         rs->md.sync_speed_max = (int)value;
 612                 } else if (!strcasecmp(key, "region_size")) {
 613                         rs->print_flags |= DMPF_REGION_SIZE;
 614                         region_size = value;
 615                 } else if (!strcasecmp(key, "raid10_copies") &&
 616                            (rs->raid_type->level == 10)) {
 617                         if ((value < 2) || (value > 0xFF)) {
 618                                 rs->ti->error = "Bad value for 'raid10_copies'";
 619                                 return -EINVAL;
 620                         }
 621                         rs->print_flags |= DMPF_RAID10_COPIES;
 622                         raid10_copies = value;
 623                 } else {
 624                         DMERR("Unable to parse RAID parameter: %s", key);
 625                         rs->ti->error = "Unable to parse RAID parameters";
 626                         return -EINVAL;
 627                 }
 628         }
 629
 630         if (validate_region_size(rs, region_size))
 631                 return -EINVAL;
 632
 633         if (rs->md.chunk_sectors)
 634                 max_io_len = rs->md.chunk_sectors;
 635         else
 636                 max_io_len = region_size;
 637
 638         if (dm_set_target_max_io_len(rs->ti, max_io_len))
 639                 return -EINVAL;
 640
 641         if (rs->raid_type->level == 10) {
 642                 if (raid10_copies > rs->md.raid_disks) {
 643                         rs->ti->error = "Not enough devices to satisfy specification";
 644                         return -EINVAL;
 645                 }
 646
 647                 /* (Len * #mirrors) / #devices */
 648                 sectors_per_dev = rs->ti->len * raid10_copies;
 649                 sector_div(sectors_per_dev, rs->md.raid_disks);
 650
 651                 rs->md.layout = raid10_format_to_md_layout(raid10_format,
 652                                                            raid10_copies);
 653                 rs->md.new_layout = rs->md.layout;
 654         } else if ((rs->raid_type->level > 1) &&
 655                    sector_div(sectors_per_dev,
 656                               (rs->md.raid_disks - rs->raid_type->parity_devs))) {
 657                 rs->ti->error = "Target length not divisible by number of data devices";
 658                 return -EINVAL;
 659         }
 660         rs->md.dev_sectors = sectors_per_dev;
 661
 662         /* Assume there are no metadata devices until the drives are parsed */
 663         rs->md.persistent = 0;
 664         rs->md.external = 1;
 665
 666         return 0;
 667 }
 668
 669 static void do_table_event(struct work_struct *ws)
 670 {
 671         struct raid_set *rs = container_of(ws, struct raid_set, md.event_work);
 672
 673         dm_table_event(rs->ti->table);
 674 }
 675
 676 static int raid_is_congested(struct dm_target_callbacks *cb, int bits)
 677 {
 678         struct raid_set *rs = container_of(cb, struct raid_set, callbacks);
 679
 680         if (rs->raid_type->level == 1)
 681                 return md_raid1_congested(&rs->md, bits);
 682
 683         if (rs->raid_type->level == 10)
 684                 return md_raid10_congested(&rs->md, bits);
 685
 686         return md_raid5_congested(&rs->md, bits);
 687 }
 688
 689 /*
 690  * This structure is never routinely used by userspace, unlike md superblocks.
 691  * Devices with this superblock should only ever be accessed via device-mapper.
 692  */
 693 #define DM_RAID_MAGIC 0x64526D44
 694 struct dm_raid_superblock {
 695         __le32 magic;           /* "DmRd" */
 696         __le32 features;        /* Used to indicate possible future changes */
 697
 698         __le32 num_devices;     /* Number of devices in this array. (Max 64) */
 699         __le32 array_position;  /* The position of this drive in the array */
 700
 701         __le64 events;          /* Incremented by md when superblock updated */
 702         __le64 failed_devices;  /* Bit field of devices to indicate failures */
 703
 704         /*
 705          * This offset tracks the progress of the repair or replacement of
 706          * an individual drive.
 707          */
 708         __le64 disk_recovery_offset;
 709
 710         /*
 711          * This offset tracks the progress of the initial array
 712          * synchronisation/parity calculation.
 713          */
 714         __le64 array_resync_offset;
 715
 716         /*
 717          * RAID characteristics
 718          */
 719         __le32 level;
 720         __le32 layout;
 721         __le32 stripe_sectors;
 722
 723         __u8 pad[452];          /* Round struct to 512 bytes. */
 724                                 /* Always set to 0 when writing. */
 725 } __packed;
 726
 727 static int read_disk_sb(struct md_rdev *rdev, int size)
 728 {
 729         BUG_ON(!rdev->sb_page);
 730
 731         if (rdev->sb_loaded)
 732                 return 0;
 733
 734         if (!sync_page_io(rdev, 0, size, rdev->sb_page, READ, 1)) {
 735                 DMERR("Failed to read superblock of device at position %d",
 736                       rdev->raid_disk);
 737                 md_error(rdev->mddev, rdev);
 738                 return -EINVAL;
 739         }
 740
 741         rdev->sb_loaded = 1;
 742
 743         return 0;
 744 }
 745
 746 static void super_sync(struct mddev *mddev, struct md_rdev *rdev)
 747 {
 748         int i;
 749         uint64_t failed_devices;
 750         struct dm_raid_superblock *sb;
 751         struct raid_set *rs = container_of(mddev, struct raid_set, md);
 752
 753         sb = page_address(rdev->sb_page);
 754         failed_devices = le64_to_cpu(sb->failed_devices);
 755
 756         for (i = 0; i < mddev->raid_disks; i++)
 757                 if (!rs->dev[i].data_dev ||
 758                     test_bit(Faulty, &(rs->dev[i].rdev.flags)))
 759                         failed_devices |= (1ULL << i);
 760
 761         memset(sb, 0, sizeof(*sb));
 762
 763         sb->magic = cpu_to_le32(DM_RAID_MAGIC);
 764         sb->features = cpu_to_le32(0);  /* No features yet */
 765
 766         sb->num_devices = cpu_to_le32(mddev->raid_disks);
 767         sb->array_position = cpu_to_le32(rdev->raid_disk);
 768
 769         sb->events = cpu_to_le64(mddev->events);
 770         sb->failed_devices = cpu_to_le64(failed_devices);
 771
 772         sb->disk_recovery_offset = cpu_to_le64(rdev->recovery_offset);
 773         sb->array_resync_offset = cpu_to_le64(mddev->recovery_cp);
 774
 775         sb->level = cpu_to_le32(mddev->level);
 776         sb->layout = cpu_to_le32(mddev->layout);
 777         sb->stripe_sectors = cpu_to_le32(mddev->chunk_sectors);
 778 }
 779
 780 /*
 781  * super_load
 782  *
 783  * This function creates a superblock if one is not found on the device
 784  * and will decide which superblock to use if there's a choice.
 785  *
 786  * Return: 1 if use rdev, 0 if use refdev, -Exxx otherwise
 787  */
 788 static int super_load(struct md_rdev *rdev, struct md_rdev *refdev)
 789 {
 790         int ret;
 791         struct dm_raid_superblock *sb;
 792         struct dm_raid_superblock *refsb;
 793         uint64_t events_sb, events_refsb;
 794
 795         rdev->sb_start = 0;
 796         rdev->sb_size = sizeof(*sb);
 797
 798         ret = read_disk_sb(rdev, rdev->sb_size);
 799         if (ret)
 800                 return ret;
 801
 802         sb = page_address(rdev->sb_page);
 803
 804         /*
 805          * Two cases that we want to write new superblocks and rebuild:
 806          * 1) New device (no matching magic number)
 807          * 2) Device specified for rebuild (!In_sync w/ offset == 0)
 808          */
 809         if ((sb->magic != cpu_to_le32(DM_RAID_MAGIC)) ||
 810             (!test_bit(In_sync, &rdev->flags) && !rdev->recovery_offset)) {
 811                 super_sync(rdev->mddev, rdev);
 812
 813                 set_bit(FirstUse, &rdev->flags);
 814
 815                 /* Force writing of superblocks to disk */
 816                 set_bit(MD_CHANGE_DEVS, &rdev->mddev->flags);
 817
 818                 /* Any superblock is better than none, choose that if given */
 819                 return refdev ? 0 : 1;
 820         }
 821
 822         if (!refdev)
 823                 return 1;
 824
 825         events_sb = le64_to_cpu(sb->events);
 826
 827         refsb = page_address(refdev->sb_page);
 828         events_refsb = le64_to_cpu(refsb->events);
 829
 830         return (events_sb > events_refsb) ? 1 : 0;
 831 }
 832
 833 static int super_init_validation(struct mddev *mddev, struct md_rdev *rdev)
 834 {
 835         int role;
 836         struct raid_set *rs = container_of(mddev, struct raid_set, md);
 837         uint64_t events_sb;
 838         uint64_t failed_devices;
 839         struct dm_raid_superblock *sb;
 840         uint32_t new_devs = 0;
 841         uint32_t rebuilds = 0;
 842         struct md_rdev *r;
 843         struct dm_raid_superblock *sb2;
 844
 845         sb = page_address(rdev->sb_page);
 846         events_sb = le64_to_cpu(sb->events);
 847         failed_devices = le64_to_cpu(sb->failed_devices);
 848
 849         /*
 850          * Initialise to 1 if this is a new superblock.
 851          */
 852         mddev->events = events_sb ? : 1;
 853
 854         /*
 855          * Reshaping is not currently allowed
 856          */
 857         if ((le32_to_cpu(sb->level) != mddev->level) ||
 858             (le32_to_cpu(sb->layout) != mddev->layout) ||
 859             (le32_to_cpu(sb->stripe_sectors) != mddev->chunk_sectors)) {
 860                 DMERR("Reshaping arrays not yet supported.");
 861                 return -EINVAL;
 862         }
 863
 864         /* We can only change the number of devices in RAID1 right now */
 865         if ((rs->raid_type->level != 1) &&
 866             (le32_to_cpu(sb->num_devices) != mddev->raid_disks)) {
 867                 DMERR("Reshaping arrays not yet supported.");
 868                 return -EINVAL;
 869         }
 870
 871         if (!(rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC)))
 872                 mddev->recovery_cp = le64_to_cpu(sb->array_resync_offset);
 873
 874         /*
 875          * During load, we set FirstUse if a new superblock was written.
 876          * There are two reasons we might not have a superblock:
 877          * 1) The array is brand new - in which case, all of the
 878          *    devices must have their In_sync bit set.  Also,
 879          *    recovery_cp must be 0, unless forced.
 880          * 2) This is a new device being added to an old array
 881          *    and the new device needs to be rebuilt - in which
 882          *    case the In_sync bit will /not/ be set and
 883          *    recovery_cp must be MaxSector.
 884          */
 885         rdev_for_each(r, mddev) {
 886                 if (!test_bit(In_sync, &r->flags)) {
 887                         DMINFO("Device %d specified for rebuild: "
 888                                "Clearing superblock", r->raid_disk);
 889                         rebuilds++;
 890                 } else if (test_bit(FirstUse, &r->flags))
 891                         new_devs++;
 892         }
 893
 894         if (!rebuilds) {
 895                 if (new_devs == mddev->raid_disks) {
 896                         DMINFO("Superblocks created for new array");
 897                         set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
 898                 } else if (new_devs) {
 899                         DMERR("New device injected "
 900                               "into existing array without 'rebuild' "
 901                               "parameter specified");
 902                         return -EINVAL;
 903                 }
 904         } else if (new_devs) {
 905                 DMERR("'rebuild' devices cannot be "
 906                       "injected into an array with other first-time devices");
 907                 return -EINVAL;
 908         } else if (mddev->recovery_cp != MaxSector) {
 909                 DMERR("'rebuild' specified while array is not in-sync");
 910                 return -EINVAL;
 911         }
 912
 913         /*
 914          * Now we set the Faulty bit for those devices that are
 915          * recorded in the superblock as failed.
 916          */
 917         rdev_for_each(r, mddev) {
 918                 if (!r->sb_page)
 919                         continue;
 920                 sb2 = page_address(r->sb_page);
 921                 sb2->failed_devices = 0;
 922
 923                 /*
 924                  * Check for any device re-ordering.
 925                  */
 926                 if (!test_bit(FirstUse, &r->flags) && (r->raid_disk >= 0)) {
 927                         role = le32_to_cpu(sb2->array_position);
 928                         if (role != r->raid_disk) {
 929                                 if (rs->raid_type->level != 1) {
 930                                         rs->ti->error = "Cannot change device "
 931                                                 "positions in RAID array";
 932                                         return -EINVAL;
 933                                 }
 934                                 DMINFO("RAID1 device #%d now at position #%d",
 935                                        role, r->raid_disk);
 936                         }
 937
 938                         /*
 939                          * Partial recovery is performed on
 940                          * returning failed devices.
 941                          */
 942                         if (failed_devices & (1 << role))
 943                                 set_bit(Faulty, &r->flags);
 944                 }
 945         }
 946
 947         return 0;
 948 }
 949
 950 static int super_validate(struct mddev *mddev, struct md_rdev *rdev)
 951 {
 952         struct dm_raid_superblock *sb = page_address(rdev->sb_page);
 953
 954         /*
 955          * If mddev->events is not set, we know we have not yet initialized
 956          * the array.
 957          */
 958         if (!mddev->events && super_init_validation(mddev, rdev))
 959                 return -EINVAL;
 960
 961         mddev->bitmap_info.offset = 4096 >> 9; /* Enable bitmap creation */
 962         rdev->mddev->bitmap_info.default_offset = 4096 >> 9;
 963         if (!test_bit(FirstUse, &rdev->flags)) {
 964                 rdev->recovery_offset = le64_to_cpu(sb->disk_recovery_offset);
 965                 if (rdev->recovery_offset != MaxSector)
 966                         clear_bit(In_sync, &rdev->flags);
 967         }
 968
 969         /*
 970          * If a device comes back, set it as not In_sync and no longer faulty.
 971          */
 972         if (test_bit(Faulty, &rdev->flags)) {
 973                 clear_bit(Faulty, &rdev->flags);
 974                 clear_bit(In_sync, &rdev->flags);
 975                 rdev->saved_raid_disk = rdev->raid_disk;
 976                 rdev->recovery_offset = 0;
 977         }
 978
 979         clear_bit(FirstUse, &rdev->flags);
 980
 981         return 0;
 982 }
 983
 984 /*
 985  * Analyse superblocks and select the freshest.
 986  */
 987 static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
 988 {
 989         int ret;
 990         struct raid_dev *dev;
 991         struct md_rdev *rdev, *tmp, *freshest;
 992         struct mddev *mddev = &rs->md;
 993
 994         freshest = NULL;
 995         rdev_for_each_safe(rdev, tmp, mddev) {
 996                 /*
 997                  * Skipping super_load due to DMPF_SYNC will cause
 998                  * the array to undergo initialization again as
 999                  * though it were new.  This is the intended effect
1000                  * of the "sync" directive.
1001                  *
1002                  * When reshaping capability is added, we must ensure
1003                  * that the "sync" directive is disallowed during the
1004                  * reshape.
1005                  */
1006                 if (rs->print_flags & DMPF_SYNC)
1007                         continue;
1008
1009                 if (!rdev->meta_bdev)
1010                         continue;
1011
1012                 ret = super_load(rdev, freshest);
1013
1014                 switch (ret) {
1015                 case 1:
1016                         freshest = rdev;
1017                         break;
1018                 case 0:
1019                         break;
1020                 default:
1021                         dev = container_of(rdev, struct raid_dev, rdev);
1022                         if (dev->meta_dev)
1023                                 dm_put_device(ti, dev->meta_dev);
1024
1025                         dev->meta_dev = NULL;
1026                         rdev->meta_bdev = NULL;
1027
1028                         if (rdev->sb_page)
1029                                 put_page(rdev->sb_page);
1030
1031                         rdev->sb_page = NULL;
1032
1033                         rdev->sb_loaded = 0;
1034
1035                         /*
1036                          * We might be able to salvage the data device
1037                          * even though the meta device has failed.  For
1038                          * now, we behave as though '- -' had been
1039                          * set for this device in the table.
1040                          */
1041                         if (dev->data_dev)
1042                                 dm_put_device(ti, dev->data_dev);
1043
1044                         dev->data_dev = NULL;
1045                         rdev->bdev = NULL;
1046
1047                         list_del(&rdev->same_set);
1048                 }
1049         }
1050
1051         if (!freshest)
1052                 return 0;
1053
1054         if (validate_raid_redundancy(rs)) {
1055                 rs->ti->error = "Insufficient redundancy to activate array";
1056                 return -EINVAL;
1057         }
1058
1059         /*
1060          * Validation of the freshest device provides the source of
1061          * validation for the remaining devices.
1062          */
1063         ti->error = "Unable to assemble array: Invalid superblocks";
1064         if (super_validate(mddev, freshest))
1065                 return -EINVAL;
1066
1067         rdev_for_each(rdev, mddev)
1068                 if ((rdev != freshest) && super_validate(mddev, rdev))
1069                         return -EINVAL;
1070
1071         return 0;
1072 }
1073
1074 /*
1075  * Construct a RAID4/5/6 mapping:
1076  * Args:
1077  *      <raid_type> <#raid_params> <raid_params>                \
1078  *      <#raid_devs> { <meta_dev1> <dev1> .. <meta_devN> <devN> }
1079  *
1080  * <raid_params> varies by <raid_type>.  See 'parse_raid_params' for
1081  * details on possible <raid_params>.
1082  */
1083 static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
1084 {
1085         int ret;
1086         struct raid_type *rt;
1087         unsigned long num_raid_params, num_raid_devs;
1088         struct raid_set *rs = NULL;
1089
1090         /* Must have at least <raid_type> <#raid_params> */
1091         if (argc < 2) {
1092                 ti->error = "Too few arguments";
1093                 return -EINVAL;
1094         }
1095
1096         /* raid type */
1097         rt = get_raid_type(argv[0]);
1098         if (!rt) {
1099                 ti->error = "Unrecognised raid_type";
1100                 return -EINVAL;
1101         }
1102         argc--;
1103         argv++;
1104
1105         /* number of RAID parameters */
1106         if (strict_strtoul(argv[0], 10, &num_raid_params) < 0) {
1107                 ti->error = "Cannot understand number of RAID parameters";
1108                 return -EINVAL;
1109         }
1110         argc--;
1111         argv++;
1112
1113         /* Skip over RAID params for now and find out # of devices */
1114         if (num_raid_params + 1 > argc) {
1115                 ti->error = "Arguments do not agree with counts given";
1116                 return -EINVAL;
1117         }
1118
1119         if ((strict_strtoul(argv[num_raid_params], 10, &num_raid_devs) < 0) ||
1120             (num_raid_devs >= INT_MAX)) {
1121                 ti->error = "Cannot understand number of raid devices";
1122                 return -EINVAL;
1123         }
1124
1125         rs = context_alloc(ti, rt, (unsigned)num_raid_devs);
1126         if (IS_ERR(rs))
1127                 return PTR_ERR(rs);
1128
1129         ret = parse_raid_params(rs, argv, (unsigned)num_raid_params);
1130         if (ret)
1131                 goto bad;
1132
1133         ret = -EINVAL;
1134
1135         argc -= num_raid_params + 1; /* +1: we already have num_raid_devs */
1136         argv += num_raid_params + 1;
1137
1138         if (argc != (num_raid_devs * 2)) {
1139                 ti->error = "Supplied RAID devices does not match the count given";
1140                 goto bad;
1141         }
1142
1143         ret = dev_parms(rs, argv);
1144         if (ret)
1145                 goto bad;
1146
1147         rs->md.sync_super = super_sync;
1148         ret = analyse_superblocks(ti, rs);
1149         if (ret)
1150                 goto bad;
1151
1152         INIT_WORK(&rs->md.event_work, do_table_event);
1153         ti->private = rs;
1154         ti->num_flush_requests = 1;
1155
1156         mutex_lock(&rs->md.reconfig_mutex);
1157         ret = md_run(&rs->md);
1158         rs->md.in_sync = 0; /* Assume already marked dirty */
1159         mutex_unlock(&rs->md.reconfig_mutex);
1160
1161         if (ret) {
1162                 ti->error = "Fail to run raid array";
1163                 goto bad;
1164         }
1165
1166         if (ti->len != rs->md.array_sectors) {
1167                 ti->error = "Array size does not match requested target length";
1168                 ret = -EINVAL;
1169                 goto size_mismatch;
1170         }
1171         rs->callbacks.congested_fn = raid_is_congested;
1172         dm_table_add_target_callbacks(ti->table, &rs->callbacks);
1173
1174         mddev_suspend(&rs->md);
1175         return 0;
1176
1177 size_mismatch:
1178         md_stop(&rs->md);
1179 bad:
1180         context_free(rs);
1181
1182         return ret;
1183 }
1184
1185 static void raid_dtr(struct dm_target *ti)
1186 {
1187         struct raid_set *rs = ti->private;
1188
1189         list_del_init(&rs->callbacks.list);
1190         md_stop(&rs->md);
1191         context_free(rs);
1192 }
1193
1194 static int raid_map(struct dm_target *ti, struct bio *bio)
1195 {
1196         struct raid_set *rs = ti->private;
1197         struct mddev *mddev = &rs->md;
1198
1199         mddev->pers->make_request(mddev, bio);
1200
1201         return DM_MAPIO_SUBMITTED;
1202 }
1203
1204 static int raid_status(struct dm_target *ti, status_type_t type,
1205                        unsigned status_flags, char *result, unsigned maxlen)
1206 {
1207         struct raid_set *rs = ti->private;
1208         unsigned raid_param_cnt = 1; /* at least 1 for chunksize */
1209         unsigned sz = 0;
1210         int i, array_in_sync = 0;
1211         sector_t sync;
1212
1213         switch (type) {
1214         case STATUSTYPE_INFO:
1215                 DMEMIT("%s %d ", rs->raid_type->name, rs->md.raid_disks);
1216
1217                 if (test_bit(MD_RECOVERY_RUNNING, &rs->md.recovery))
1218                         sync = rs->md.curr_resync_completed;
1219                 else
1220                         sync = rs->md.recovery_cp;
1221
1222                 if (sync >= rs->md.resync_max_sectors) {
1223                         array_in_sync = 1;
1224                         sync = rs->md.resync_max_sectors;
1225                 } else {
1226                         /*
1227                          * The array may be doing an initial sync, or it may
1228                          * be rebuilding individual components.  If all the
1229                          * devices are In_sync, then it is the array that is
1230                          * being initialized.
1231                          */
1232                         for (i = 0; i < rs->md.raid_disks; i++)
1233                                 if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
1234                                         array_in_sync = 1;
1235                 }
1236                 /*
1237                  * Status characters:
1238                  *  'D' = Dead/Failed device
1239                  *  'a' = Alive but not in-sync
1240                  *  'A' = Alive and in-sync
1241                  */
1242                 for (i = 0; i < rs->md.raid_disks; i++) {
1243                         if (test_bit(Faulty, &rs->dev[i].rdev.flags))
1244                                 DMEMIT("D");
1245                         else if (!array_in_sync ||
1246                                  !test_bit(In_sync, &rs->dev[i].rdev.flags))
1247                                 DMEMIT("a");
1248                         else
1249                                 DMEMIT("A");
1250                 }
1251
1252                 /*
1253                  * In-sync ratio:
1254                  *  The in-sync ratio shows the progress of:
1255                  *   - Initializing the array
1256                  *   - Rebuilding a subset of devices of the array
1257                  *  The user can distinguish between the two by referring
1258                  *  to the status characters.
1259                  */
1260                 DMEMIT(" %llu/%llu",
1261                        (unsigned long long) sync,
1262                        (unsigned long long) rs->md.resync_max_sectors);
1263
1264                 break;
1265         case STATUSTYPE_TABLE:
1266                 /* The string you would use to construct this array */
1267                 for (i = 0; i < rs->md.raid_disks; i++) {
1268                         if ((rs->print_flags & DMPF_REBUILD) &&
1269                             rs->dev[i].data_dev &&
1270                             !test_bit(In_sync, &rs->dev[i].rdev.flags))
1271                                 raid_param_cnt += 2; /* for rebuilds */
1272                         if (rs->dev[i].data_dev &&
1273                             test_bit(WriteMostly, &rs->dev[i].rdev.flags))
1274                                 raid_param_cnt += 2;
1275                 }
1276
1277                 raid_param_cnt += (hweight32(rs->print_flags & ~DMPF_REBUILD) * 2);
1278                 if (rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC))
1279                         raid_param_cnt--;
1280
1281                 DMEMIT("%s %u %u", rs->raid_type->name,
1282                        raid_param_cnt, rs->md.chunk_sectors);
1283
1284                 if ((rs->print_flags & DMPF_SYNC) &&
1285                     (rs->md.recovery_cp == MaxSector))
1286                         DMEMIT(" sync");
1287                 if (rs->print_flags & DMPF_NOSYNC)
1288                         DMEMIT(" nosync");
1289
1290                 for (i = 0; i < rs->md.raid_disks; i++)
1291                         if ((rs->print_flags & DMPF_REBUILD) &&
1292                             rs->dev[i].data_dev &&
1293                             !test_bit(In_sync, &rs->dev[i].rdev.flags))
1294                                 DMEMIT(" rebuild %u", i);
1295
1296                 if (rs->print_flags & DMPF_DAEMON_SLEEP)
1297                         DMEMIT(" daemon_sleep %lu",
1298                                rs->md.bitmap_info.daemon_sleep);
1299
1300                 if (rs->print_flags & DMPF_MIN_RECOVERY_RATE)
1301                         DMEMIT(" min_recovery_rate %d", rs->md.sync_speed_min);
1302
1303                 if (rs->print_flags & DMPF_MAX_RECOVERY_RATE)
1304                         DMEMIT(" max_recovery_rate %d", rs->md.sync_speed_max);
1305
1306                 for (i = 0; i < rs->md.raid_disks; i++)
1307                         if (rs->dev[i].data_dev &&
1308                             test_bit(WriteMostly, &rs->dev[i].rdev.flags))
1309                                 DMEMIT(" write_mostly %u", i);
1310
1311                 if (rs->print_flags & DMPF_MAX_WRITE_BEHIND)
1312                         DMEMIT(" max_write_behind %lu",
1313                                rs->md.bitmap_info.max_write_behind);
1314
1315                 if (rs->print_flags & DMPF_STRIPE_CACHE) {
1316                         struct r5conf *conf = rs->md.private;
1317
1318                         /* convert from kiB to sectors */
1319                         DMEMIT(" stripe_cache %d",
1320                                conf ? conf->max_nr_stripes * 2 : 0);
1321                 }
1322
1323                 if (rs->print_flags & DMPF_REGION_SIZE)
1324                         DMEMIT(" region_size %lu",
1325                                rs->md.bitmap_info.chunksize >> 9);
1326
1327                 if (rs->print_flags & DMPF_RAID10_COPIES)
1328                         DMEMIT(" raid10_copies %u",
1329                                raid10_md_layout_to_copies(rs->md.layout));
1330
1331                 if (rs->print_flags & DMPF_RAID10_FORMAT)
1332                         DMEMIT(" raid10_format near");
1333
1334                 DMEMIT(" %d", rs->md.raid_disks);
1335                 for (i = 0; i < rs->md.raid_disks; i++) {
1336                         if (rs->dev[i].meta_dev)
1337                                 DMEMIT(" %s", rs->dev[i].meta_dev->name);
1338                         else
1339                                 DMEMIT(" -");
1340
1341                         if (rs->dev[i].data_dev)
1342                                 DMEMIT(" %s", rs->dev[i].data_dev->name);
1343                         else
1344                                 DMEMIT(" -");
1345                 }
1346         }
1347
1348         return 0;
1349 }
1350
1351 static int raid_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data)
1352 {
1353         struct raid_set *rs = ti->private;
1354         unsigned i;
1355         int ret = 0;
1356
1357         for (i = 0; !ret && i < rs->md.raid_disks; i++)
1358                 if (rs->dev[i].data_dev)
1359                         ret = fn(ti,
1360                                  rs->dev[i].data_dev,
1361                                  0, /* No offset on data devs */
1362                                  rs->md.dev_sectors,
1363                                  data);
1364
1365         return ret;
1366 }
1367
1368 static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
1369 {
1370         struct raid_set *rs = ti->private;
1371         unsigned chunk_size = rs->md.chunk_sectors << 9;
1372         struct r5conf *conf = rs->md.private;
1373
1374         blk_limits_io_min(limits, chunk_size);
1375         blk_limits_io_opt(limits, chunk_size * (conf->raid_disks - conf->max_degraded));
1376 }
1377
1378 static void raid_presuspend(struct dm_target *ti)
1379 {
1380         struct raid_set *rs = ti->private;
1381
1382         md_stop_writes(&rs->md);
1383 }
1384
1385 static void raid_postsuspend(struct dm_target *ti)
1386 {
1387         struct raid_set *rs = ti->private;
1388
1389         mddev_suspend(&rs->md);
1390 }
1391
1392 static void raid_resume(struct dm_target *ti)
1393 {
1394         struct raid_set *rs = ti->private;
1395
1396         set_bit(MD_CHANGE_DEVS, &rs->md.flags);
1397         if (!rs->bitmap_loaded) {
1398                 bitmap_load(&rs->md);
1399                 rs->bitmap_loaded = 1;
1400         }
1401
1402         clear_bit(MD_RECOVERY_FROZEN, &rs->md.recovery);
1403         mddev_resume(&rs->md);
1404 }
1405
1406 static struct target_type raid_target = {
1407         .name = "raid",
1408         .version = {1, 4, 1},
1409         .module = THIS_MODULE,
1410         .ctr = raid_ctr,
1411         .dtr = raid_dtr,
1412         .map = raid_map,
1413         .status = raid_status,
1414         .iterate_devices = raid_iterate_devices,
1415         .io_hints = raid_io_hints,
1416         .presuspend = raid_presuspend,
1417         .postsuspend = raid_postsuspend,
1418         .resume = raid_resume,
1419 };
1420
1421 static int __init dm_raid_init(void)
1422 {
1423         return dm_register_target(&raid_target);
1424 }
1425
1426 static void __exit dm_raid_exit(void)
1427 {
1428         dm_unregister_target(&raid_target);
1429 }
1430
1431 module_init(dm_raid_init);
1432 module_exit(dm_raid_exit);
1433
1434 MODULE_DESCRIPTION(DM_NAME " raid4/5/6 target");
1435 MODULE_ALIAS("dm-raid1");
1436 MODULE_ALIAS("dm-raid10");
1437 MODULE_ALIAS("dm-raid4");
1438 MODULE_ALIAS("dm-raid5");
1439 MODULE_ALIAS("dm-raid6");
1440 MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>");
1441 MODULE_LICENSE("GPL");