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 char *raid10_md_layout_to_format(int layout)
  95 {
  96         /*
  97          * Bit 16 and 17 stand for "offset" and "use_far_sets"
  98          * Refer to MD's raid10.c for details
  99          */
 100         if ((layout & 0x10000) && (layout & 0x20000))
 101                 return "offset";
 102
 103         if ((layout & 0xFF) > 1)
 104                 return "near";
 105
 106         return "far";
 107 }
 108
 109 static unsigned raid10_md_layout_to_copies(int layout)
 110 {
 111         if ((layout & 0xFF) > 1)
 112                 return layout & 0xFF;
 113         return (layout >> 8) & 0xFF;
 114 }
 115
 116 static int raid10_format_to_md_layout(char *format, unsigned copies)
 117 {
 118         unsigned n = 1, f = 1;
 119
 120         if (!strcmp("near", format))
 121                 n = copies;
 122         else
 123                 f = copies;
 124
 125         if (!strcmp("offset", format))
 126                 return 0x30000 | (f << 8) | n;
 127
 128         if (!strcmp("far", format))
 129                 return 0x20000 | (f << 8) | n;
 130
 131         return (f << 8) | n;
 132 }
 133
 134 static struct raid_type *get_raid_type(char *name)
 135 {
 136         int i;
 137
 138         for (i = 0; i < ARRAY_SIZE(raid_types); i++)
 139                 if (!strcmp(raid_types[i].name, name))
 140                         return &raid_types[i];
 141
 142         return NULL;
 143 }
 144
 145 static struct raid_set *context_alloc(struct dm_target *ti, struct raid_type *raid_type, unsigned raid_devs)
 146 {
 147         unsigned i;
 148         struct raid_set *rs;
 149
 150         if (raid_devs <= raid_type->parity_devs) {
 151                 ti->error = "Insufficient number of devices";
 152                 return ERR_PTR(-EINVAL);
 153         }
 154
 155         rs = kzalloc(sizeof(*rs) + raid_devs * sizeof(rs->dev[0]), GFP_KERNEL);
 156         if (!rs) {
 157                 ti->error = "Cannot allocate raid context";
 158                 return ERR_PTR(-ENOMEM);
 159         }
 160
 161         mddev_init(&rs->md);
 162
 163         rs->ti = ti;
 164         rs->raid_type = raid_type;
 165         rs->md.raid_disks = raid_devs;
 166         rs->md.level = raid_type->level;
 167         rs->md.new_level = rs->md.level;
 168         rs->md.layout = raid_type->algorithm;
 169         rs->md.new_layout = rs->md.layout;
 170         rs->md.delta_disks = 0;
 171         rs->md.recovery_cp = 0;
 172
 173         for (i = 0; i < raid_devs; i++)
 174                 md_rdev_init(&rs->dev[i].rdev);
 175
 176         /*
 177          * Remaining items to be initialized by further RAID params:
 178          *  rs->md.persistent
 179          *  rs->md.external
 180          *  rs->md.chunk_sectors
 181          *  rs->md.new_chunk_sectors
 182          *  rs->md.dev_sectors
 183          */
 184
 185         return rs;
 186 }
 187
 188 static void context_free(struct raid_set *rs)
 189 {
 190         int i;
 191
 192         for (i = 0; i < rs->md.raid_disks; i++) {
 193                 if (rs->dev[i].meta_dev)
 194                         dm_put_device(rs->ti, rs->dev[i].meta_dev);
 195                 md_rdev_clear(&rs->dev[i].rdev);
 196                 if (rs->dev[i].data_dev)
 197                         dm_put_device(rs->ti, rs->dev[i].data_dev);
 198         }
 199
 200         kfree(rs);
 201 }
 202
 203 /*
 204  * For every device we have two words
 205  *  <meta_dev>: meta device name or '-' if missing
 206  *  <data_dev>: data device name or '-' if missing
 207  *
 208  * The following are permitted:
 209  *    - -
 210  *    - <data_dev>
 211  *    <meta_dev> <data_dev>
 212  *
 213  * The following is not allowed:
 214  *    <meta_dev> -
 215  *
 216  * This code parses those words.  If there is a failure,
 217  * the caller must use context_free to unwind the operations.
 218  */
 219 static int dev_parms(struct raid_set *rs, char **argv)
 220 {
 221         int i;
 222         int rebuild = 0;
 223         int metadata_available = 0;
 224         int ret = 0;
 225
 226         for (i = 0; i < rs->md.raid_disks; i++, argv += 2) {
 227                 rs->dev[i].rdev.raid_disk = i;
 228
 229                 rs->dev[i].meta_dev = NULL;
 230                 rs->dev[i].data_dev = NULL;
 231
 232                 /*
 233                  * There are no offsets, since there is a separate device
 234                  * for data and metadata.
 235                  */
 236                 rs->dev[i].rdev.data_offset = 0;
 237                 rs->dev[i].rdev.mddev = &rs->md;
 238
 239                 if (strcmp(argv[0], "-")) {
 240                         ret = dm_get_device(rs->ti, argv[0],
 241                                             dm_table_get_mode(rs->ti->table),
 242                                             &rs->dev[i].meta_dev);
 243                         rs->ti->error = "RAID metadata device lookup failure";
 244                         if (ret)
 245                                 return ret;
 246
 247                         rs->dev[i].rdev.sb_page = alloc_page(GFP_KERNEL);
 248                         if (!rs->dev[i].rdev.sb_page)
 249                                 return -ENOMEM;
 250                 }
 251
 252                 if (!strcmp(argv[1], "-")) {
 253                         if (!test_bit(In_sync, &rs->dev[i].rdev.flags) &&
 254                             (!rs->dev[i].rdev.recovery_offset)) {
 255                                 rs->ti->error = "Drive designated for rebuild not specified";
 256                                 return -EINVAL;
 257                         }
 258
 259                         rs->ti->error = "No data device supplied with metadata device";
 260                         if (rs->dev[i].meta_dev)
 261                                 return -EINVAL;
 262
 263                         continue;
 264                 }
 265
 266                 ret = dm_get_device(rs->ti, argv[1],
 267                                     dm_table_get_mode(rs->ti->table),
 268                                     &rs->dev[i].data_dev);
 269                 if (ret) {
 270                         rs->ti->error = "RAID device lookup failure";
 271                         return ret;
 272                 }
 273
 274                 if (rs->dev[i].meta_dev) {
 275                         metadata_available = 1;
 276                         rs->dev[i].rdev.meta_bdev = rs->dev[i].meta_dev->bdev;
 277                 }
 278                 rs->dev[i].rdev.bdev = rs->dev[i].data_dev->bdev;
 279                 list_add(&rs->dev[i].rdev.same_set, &rs->md.disks);
 280                 if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
 281                         rebuild++;
 282         }
 283
 284         if (metadata_available) {
 285                 rs->md.external = 0;
 286                 rs->md.persistent = 1;
 287                 rs->md.major_version = 2;
 288         } else if (rebuild && !rs->md.recovery_cp) {
 289                 /*
 290                  * Without metadata, we will not be able to tell if the array
 291                  * is in-sync or not - we must assume it is not.  Therefore,
 292                  * it is impossible to rebuild a drive.
 293                  *
 294                  * Even if there is metadata, the on-disk information may
 295                  * indicate that the array is not in-sync and it will then
 296                  * fail at that time.
 297                  *
 298                  * User could specify 'nosync' option if desperate.
 299                  */
 300                 DMERR("Unable to rebuild drive while array is not in-sync");
 301                 rs->ti->error = "RAID device lookup failure";
 302                 return -EINVAL;
 303         }
 304
 305         return 0;
 306 }
 307
 308 /*
 309  * validate_region_size
 310  * @rs
 311  * @region_size:  region size in sectors.  If 0, pick a size (4MiB default).
 312  *
 313  * Set rs->md.bitmap_info.chunksize (which really refers to 'region size').
 314  * Ensure that (ti->len/region_size < 2^21) - required by MD bitmap.
 315  *
 316  * Returns: 0 on success, -EINVAL on failure.
 317  */
 318 static int validate_region_size(struct raid_set *rs, unsigned long region_size)
 319 {
 320         unsigned long min_region_size = rs->ti->len / (1 << 21);
 321
 322         if (!region_size) {
 323                 /*
 324                  * Choose a reasonable default.  All figures in sectors.
 325                  */
 326                 if (min_region_size > (1 << 13)) {
 327                         /* If not a power of 2, make it the next power of 2 */
 328                         if (min_region_size & (min_region_size - 1))
 329                                 region_size = 1 << fls(region_size);
 330                         DMINFO("Choosing default region size of %lu sectors",
 331                                region_size);
 332                 } else {
 333                         DMINFO("Choosing default region size of 4MiB");
 334                         region_size = 1 << 13; /* sectors */
 335                 }
 336         } else {
 337                 /*
 338                  * Validate user-supplied value.
 339                  */
 340                 if (region_size > rs->ti->len) {
 341                         rs->ti->error = "Supplied region size is too large";
 342                         return -EINVAL;
 343                 }
 344
 345                 if (region_size < min_region_size) {
 346                         DMERR("Supplied region_size (%lu sectors) below minimum (%lu)",
 347                               region_size, min_region_size);
 348                         rs->ti->error = "Supplied region size is too small";
 349                         return -EINVAL;
 350                 }
 351
 352                 if (!is_power_of_2(region_size)) {
 353                         rs->ti->error = "Region size is not a power of 2";
 354                         return -EINVAL;
 355                 }
 356
 357                 if (region_size < rs->md.chunk_sectors) {
 358                         rs->ti->error = "Region size is smaller than the chunk size";
 359                         return -EINVAL;
 360                 }
 361         }
 362
 363         /*
 364          * Convert sectors to bytes.
 365          */
 366         rs->md.bitmap_info.chunksize = (region_size << 9);
 367
 368         return 0;
 369 }
 370
 371 /*
 372  * validate_raid_redundancy
 373  * @rs
 374  *
 375  * Determine if there are enough devices in the array that haven't
 376  * failed (or are being rebuilt) to form a usable array.
 377  *
 378  * Returns: 0 on success, -EINVAL on failure.
 379  */
 380 static int validate_raid_redundancy(struct raid_set *rs)
 381 {
 382         unsigned i, rebuild_cnt = 0;
 383         unsigned rebuilds_per_group, copies, d;
 384         unsigned group_size, last_group_start;
 385
 386         for (i = 0; i < rs->md.raid_disks; i++)
 387                 if (!test_bit(In_sync, &rs->dev[i].rdev.flags) ||
 388                     !rs->dev[i].rdev.sb_page)
 389                         rebuild_cnt++;
 390
 391         switch (rs->raid_type->level) {
 392         case 1:
 393                 if (rebuild_cnt >= rs->md.raid_disks)
 394                         goto too_many;
 395                 break;
 396         case 4:
 397         case 5:
 398         case 6:
 399                 if (rebuild_cnt > rs->raid_type->parity_devs)
 400                         goto too_many;
 401                 break;
 402         case 10:
 403                 copies = raid10_md_layout_to_copies(rs->md.layout);
 404                 if (rebuild_cnt < copies)
 405                         break;
 406
 407                 /*
 408                  * It is possible to have a higher rebuild count for RAID10,
 409                  * as long as the failed devices occur in different mirror
 410                  * groups (i.e. different stripes).
 411                  *
 412                  * When checking "near" format, make sure no adjacent devices
 413                  * have failed beyond what can be handled.  In addition to the
 414                  * simple case where the number of devices is a multiple of the
 415                  * number of copies, we must also handle cases where the number
 416                  * of devices is not a multiple of the number of copies.
 417                  * E.g.    dev1 dev2 dev3 dev4 dev5
 418                  *          A    A    B    B    C
 419                  *          C    D    D    E    E
 420                  */
 421                 if (!strcmp("near", raid10_md_layout_to_format(rs->md.layout))) {
 422                         for (i = 0; i < rs->md.raid_disks * copies; i++) {
 423                                 if (!(i % copies))
 424                                         rebuilds_per_group = 0;
 425                                 d = i % rs->md.raid_disks;
 426                                 if ((!rs->dev[d].rdev.sb_page ||
 427                                      !test_bit(In_sync, &rs->dev[d].rdev.flags)) &&
 428                                     (++rebuilds_per_group >= copies))
 429                                         goto too_many;
 430                         }
 431                         break;
 432                 }
 433
 434                 /*
 435                  * When checking "far" and "offset" formats, we need to ensure
 436                  * that the device that holds its copy is not also dead or
 437                  * being rebuilt.  (Note that "far" and "offset" formats only
 438                  * support two copies right now.  These formats also only ever
 439                  * use the 'use_far_sets' variant.)
 440                  *
 441                  * This check is somewhat complicated by the need to account
 442                  * for arrays that are not a multiple of (far) copies.  This
 443                  * results in the need to treat the last (potentially larger)
 444                  * set differently.
 445                  */
 446                 group_size = (rs->md.raid_disks / copies);
 447                 last_group_start = (rs->md.raid_disks / group_size) - 1;
 448                 last_group_start *= group_size;
 449                 for (i = 0; i < rs->md.raid_disks; i++) {
 450                         if (!(i % copies) && !(i > last_group_start))
 451                                 rebuilds_per_group = 0;
 452                         if ((!rs->dev[i].rdev.sb_page ||
 453                              !test_bit(In_sync, &rs->dev[i].rdev.flags)) &&
 454                             (++rebuilds_per_group >= copies))
 455                                         goto too_many;
 456                 }
 457                 break;
 458         default:
 459                 if (rebuild_cnt)
 460                         return -EINVAL;
 461         }
 462
 463         return 0;
 464
 465 too_many:
 466         return -EINVAL;
 467 }
 468
 469 /*
 470  * Possible arguments are...
 471  *      <chunk_size> [optional_args]
 472  *
 473  * Argument definitions
 474  *    <chunk_size>                      The number of sectors per disk that
 475  *                                      will form the "stripe"
 476  *    [[no]sync]                        Force or prevent recovery of the
 477  *                                      entire array
 478  *    [rebuild <idx>]                   Rebuild the drive indicated by the index
 479  *    [daemon_sleep <ms>]               Time between bitmap daemon work to
 480  *                                      clear bits
 481  *    [min_recovery_rate <kB/sec/disk>] Throttle RAID initialization
 482  *    [max_recovery_rate <kB/sec/disk>] Throttle RAID initialization
 483  *    [write_mostly <idx>]              Indicate a write mostly drive via index
 484  *    [max_write_behind <sectors>]      See '-write-behind=' (man mdadm)
 485  *    [stripe_cache <sectors>]          Stripe cache size for higher RAIDs
 486  *    [region_size <sectors>]           Defines granularity of bitmap
 487  *
 488  * RAID10-only options:
 489  *    [raid10_copies <# copies>]        Number of copies.  (Default: 2)
 490  *    [raid10_format <near|far|offset>] Layout algorithm.  (Default: near)
 491  */
 492 static int parse_raid_params(struct raid_set *rs, char **argv,
 493                              unsigned num_raid_params)
 494 {
 495         char *raid10_format = "near";
 496         unsigned raid10_copies = 2;
 497         unsigned i;
 498         unsigned long value, region_size = 0;
 499         sector_t sectors_per_dev = rs->ti->len;
 500         sector_t max_io_len;
 501         char *key;
 502
 503         /*
 504          * First, parse the in-order required arguments
 505          * "chunk_size" is the only argument of this type.
 506          */
 507         if ((strict_strtoul(argv[0], 10, &value) < 0)) {
 508                 rs->ti->error = "Bad chunk size";
 509                 return -EINVAL;
 510         } else if (rs->raid_type->level == 1) {
 511                 if (value)
 512                         DMERR("Ignoring chunk size parameter for RAID 1");
 513                 value = 0;
 514         } else if (!is_power_of_2(value)) {
 515                 rs->ti->error = "Chunk size must be a power of 2";
 516                 return -EINVAL;
 517         } else if (value < 8) {
 518                 rs->ti->error = "Chunk size value is too small";
 519                 return -EINVAL;
 520         }
 521
 522         rs->md.new_chunk_sectors = rs->md.chunk_sectors = value;
 523         argv++;
 524         num_raid_params--;
 525
 526         /*
 527          * We set each individual device as In_sync with a completed
 528          * 'recovery_offset'.  If there has been a device failure or
 529          * replacement then one of the following cases applies:
 530          *
 531          *   1) User specifies 'rebuild'.
 532          *      - Device is reset when param is read.
 533          *   2) A new device is supplied.
 534          *      - No matching superblock found, resets device.
 535          *   3) Device failure was transient and returns on reload.
 536          *      - Failure noticed, resets device for bitmap replay.
 537          *   4) Device hadn't completed recovery after previous failure.
 538          *      - Superblock is read and overrides recovery_offset.
 539          *
 540          * What is found in the superblocks of the devices is always
 541          * authoritative, unless 'rebuild' or '[no]sync' was specified.
 542          */
 543         for (i = 0; i < rs->md.raid_disks; i++) {
 544                 set_bit(In_sync, &rs->dev[i].rdev.flags);
 545                 rs->dev[i].rdev.recovery_offset = MaxSector;
 546         }
 547
 548         /*
 549          * Second, parse the unordered optional arguments
 550          */
 551         for (i = 0; i < num_raid_params; i++) {
 552                 if (!strcasecmp(argv[i], "nosync")) {
 553                         rs->md.recovery_cp = MaxSector;
 554                         rs->print_flags |= DMPF_NOSYNC;
 555                         continue;
 556                 }
 557                 if (!strcasecmp(argv[i], "sync")) {
 558                         rs->md.recovery_cp = 0;
 559                         rs->print_flags |= DMPF_SYNC;
 560                         continue;
 561                 }
 562
 563                 /* The rest of the optional arguments come in key/value pairs */
 564                 if ((i + 1) >= num_raid_params) {
 565                         rs->ti->error = "Wrong number of raid parameters given";
 566                         return -EINVAL;
 567                 }
 568
 569                 key = argv[i++];
 570
 571                 /* Parameters that take a string value are checked here. */
 572                 if (!strcasecmp(key, "raid10_format")) {
 573                         if (rs->raid_type->level != 10) {
 574                                 rs->ti->error = "'raid10_format' is an invalid parameter for this RAID type";
 575                                 return -EINVAL;
 576                         }
 577                         if (strcmp("near", argv[i]) &&
 578                             strcmp("far", argv[i]) &&
 579                             strcmp("offset", argv[i])) {
 580                                 rs->ti->error = "Invalid 'raid10_format' value given";
 581                                 return -EINVAL;
 582                         }
 583                         raid10_format = argv[i];
 584                         rs->print_flags |= DMPF_RAID10_FORMAT;
 585                         continue;
 586                 }
 587
 588                 if (strict_strtoul(argv[i], 10, &value) < 0) {
 589                         rs->ti->error = "Bad numerical argument given in raid params";
 590                         return -EINVAL;
 591                 }
 592
 593                 /* Parameters that take a numeric value are checked here */
 594                 if (!strcasecmp(key, "rebuild")) {
 595                         if (value >= rs->md.raid_disks) {
 596                                 rs->ti->error = "Invalid rebuild index given";
 597                                 return -EINVAL;
 598                         }
 599                         clear_bit(In_sync, &rs->dev[value].rdev.flags);
 600                         rs->dev[value].rdev.recovery_offset = 0;
 601                         rs->print_flags |= DMPF_REBUILD;
 602                 } else if (!strcasecmp(key, "write_mostly")) {
 603                         if (rs->raid_type->level != 1) {
 604                                 rs->ti->error = "write_mostly option is only valid for RAID1";
 605                                 return -EINVAL;
 606                         }
 607                         if (value >= rs->md.raid_disks) {
 608                                 rs->ti->error = "Invalid write_mostly drive index given";
 609                                 return -EINVAL;
 610                         }
 611                         set_bit(WriteMostly, &rs->dev[value].rdev.flags);
 612                 } else if (!strcasecmp(key, "max_write_behind")) {
 613                         if (rs->raid_type->level != 1) {
 614                                 rs->ti->error = "max_write_behind option is only valid for RAID1";
 615                                 return -EINVAL;
 616                         }
 617                         rs->print_flags |= DMPF_MAX_WRITE_BEHIND;
 618
 619                         /*
 620                          * In device-mapper, we specify things in sectors, but
 621                          * MD records this value in kB
 622                          */
 623                         value /= 2;
 624                         if (value > COUNTER_MAX) {
 625                                 rs->ti->error = "Max write-behind limit out of range";
 626                                 return -EINVAL;
 627                         }
 628                         rs->md.bitmap_info.max_write_behind = value;
 629                 } else if (!strcasecmp(key, "daemon_sleep")) {
 630                         rs->print_flags |= DMPF_DAEMON_SLEEP;
 631                         if (!value || (value > MAX_SCHEDULE_TIMEOUT)) {
 632                                 rs->ti->error = "daemon sleep period out of range";
 633                                 return -EINVAL;
 634                         }
 635                         rs->md.bitmap_info.daemon_sleep = value;
 636                 } else if (!strcasecmp(key, "stripe_cache")) {
 637                         rs->print_flags |= DMPF_STRIPE_CACHE;
 638
 639                         /*
 640                          * In device-mapper, we specify things in sectors, but
 641                          * MD records this value in kB
 642                          */
 643                         value /= 2;
 644
 645                         if ((rs->raid_type->level != 5) &&
 646                             (rs->raid_type->level != 6)) {
 647                                 rs->ti->error = "Inappropriate argument: stripe_cache";
 648                                 return -EINVAL;
 649                         }
 650                         if (raid5_set_cache_size(&rs->md, (int)value)) {
 651                                 rs->ti->error = "Bad stripe_cache size";
 652                                 return -EINVAL;
 653                         }
 654                 } else if (!strcasecmp(key, "min_recovery_rate")) {
 655                         rs->print_flags |= DMPF_MIN_RECOVERY_RATE;
 656                         if (value > INT_MAX) {
 657                                 rs->ti->error = "min_recovery_rate out of range";
 658                                 return -EINVAL;
 659                         }
 660                         rs->md.sync_speed_min = (int)value;
 661                 } else if (!strcasecmp(key, "max_recovery_rate")) {
 662                         rs->print_flags |= DMPF_MAX_RECOVERY_RATE;
 663                         if (value > INT_MAX) {
 664                                 rs->ti->error = "max_recovery_rate out of range";
 665                                 return -EINVAL;
 666                         }
 667                         rs->md.sync_speed_max = (int)value;
 668                 } else if (!strcasecmp(key, "region_size")) {
 669                         rs->print_flags |= DMPF_REGION_SIZE;
 670                         region_size = value;
 671                 } else if (!strcasecmp(key, "raid10_copies") &&
 672                            (rs->raid_type->level == 10)) {
 673                         if ((value < 2) || (value > 0xFF)) {
 674                                 rs->ti->error = "Bad value for 'raid10_copies'";
 675                                 return -EINVAL;
 676                         }
 677                         rs->print_flags |= DMPF_RAID10_COPIES;
 678                         raid10_copies = value;
 679                 } else {
 680                         DMERR("Unable to parse RAID parameter: %s", key);
 681                         rs->ti->error = "Unable to parse RAID parameters";
 682                         return -EINVAL;
 683                 }
 684         }
 685
 686         if (validate_region_size(rs, region_size))
 687                 return -EINVAL;
 688
 689         if (rs->md.chunk_sectors)
 690                 max_io_len = rs->md.chunk_sectors;
 691         else
 692                 max_io_len = region_size;
 693
 694         if (dm_set_target_max_io_len(rs->ti, max_io_len))
 695                 return -EINVAL;
 696
 697         if (rs->raid_type->level == 10) {
 698                 if (raid10_copies > rs->md.raid_disks) {
 699                         rs->ti->error = "Not enough devices to satisfy specification";
 700                         return -EINVAL;
 701                 }
 702
 703                 /*
 704                  * If the format is not "near", we only support
 705                  * two copies at the moment.
 706                  */
 707                 if (strcmp("near", raid10_format) && (raid10_copies > 2)) {
 708                         rs->ti->error = "Too many copies for given RAID10 format.";
 709                         return -EINVAL;
 710                 }
 711
 712                 /* (Len * #mirrors) / #devices */
 713                 sectors_per_dev = rs->ti->len * raid10_copies;
 714                 sector_div(sectors_per_dev, rs->md.raid_disks);
 715
 716                 rs->md.layout = raid10_format_to_md_layout(raid10_format,
 717                                                            raid10_copies);
 718                 rs->md.new_layout = rs->md.layout;
 719         } else if ((rs->raid_type->level > 1) &&
 720                    sector_div(sectors_per_dev,
 721                               (rs->md.raid_disks - rs->raid_type->parity_devs))) {
 722                 rs->ti->error = "Target length not divisible by number of data devices";
 723                 return -EINVAL;
 724         }
 725         rs->md.dev_sectors = sectors_per_dev;
 726
 727         /* Assume there are no metadata devices until the drives are parsed */
 728         rs->md.persistent = 0;
 729         rs->md.external = 1;
 730
 731         return 0;
 732 }
 733
 734 static void do_table_event(struct work_struct *ws)
 735 {
 736         struct raid_set *rs = container_of(ws, struct raid_set, md.event_work);
 737
 738         dm_table_event(rs->ti->table);
 739 }
 740
 741 static int raid_is_congested(struct dm_target_callbacks *cb, int bits)
 742 {
 743         struct raid_set *rs = container_of(cb, struct raid_set, callbacks);
 744
 745         if (rs->raid_type->level == 1)
 746                 return md_raid1_congested(&rs->md, bits);
 747
 748         if (rs->raid_type->level == 10)
 749                 return md_raid10_congested(&rs->md, bits);
 750
 751         return md_raid5_congested(&rs->md, bits);
 752 }
 753
 754 /*
 755  * This structure is never routinely used by userspace, unlike md superblocks.
 756  * Devices with this superblock should only ever be accessed via device-mapper.
 757  */
 758 #define DM_RAID_MAGIC 0x64526D44
 759 struct dm_raid_superblock {
 760         __le32 magic;           /* "DmRd" */
 761         __le32 features;        /* Used to indicate possible future changes */
 762
 763         __le32 num_devices;     /* Number of devices in this array. (Max 64) */
 764         __le32 array_position;  /* The position of this drive in the array */
 765
 766         __le64 events;          /* Incremented by md when superblock updated */
 767         __le64 failed_devices;  /* Bit field of devices to indicate failures */
 768
 769         /*
 770          * This offset tracks the progress of the repair or replacement of
 771          * an individual drive.
 772          */
 773         __le64 disk_recovery_offset;
 774
 775         /*
 776          * This offset tracks the progress of the initial array
 777          * synchronisation/parity calculation.
 778          */
 779         __le64 array_resync_offset;
 780
 781         /*
 782          * RAID characteristics
 783          */
 784         __le32 level;
 785         __le32 layout;
 786         __le32 stripe_sectors;
 787
 788         __u8 pad[452];          /* Round struct to 512 bytes. */
 789                                 /* Always set to 0 when writing. */
 790 } __packed;
 791
 792 static int read_disk_sb(struct md_rdev *rdev, int size)
 793 {
 794         BUG_ON(!rdev->sb_page);
 795
 796         if (rdev->sb_loaded)
 797                 return 0;
 798
 799         if (!sync_page_io(rdev, 0, size, rdev->sb_page, READ, 1)) {
 800                 DMERR("Failed to read superblock of device at position %d",
 801                       rdev->raid_disk);
 802                 md_error(rdev->mddev, rdev);
 803                 return -EINVAL;
 804         }
 805
 806         rdev->sb_loaded = 1;
 807
 808         return 0;
 809 }
 810
 811 static void super_sync(struct mddev *mddev, struct md_rdev *rdev)
 812 {
 813         int i;
 814         uint64_t failed_devices;
 815         struct dm_raid_superblock *sb;
 816         struct raid_set *rs = container_of(mddev, struct raid_set, md);
 817
 818         sb = page_address(rdev->sb_page);
 819         failed_devices = le64_to_cpu(sb->failed_devices);
 820
 821         for (i = 0; i < mddev->raid_disks; i++)
 822                 if (!rs->dev[i].data_dev ||
 823                     test_bit(Faulty, &(rs->dev[i].rdev.flags)))
 824                         failed_devices |= (1ULL << i);
 825
 826         memset(sb, 0, sizeof(*sb));
 827
 828         sb->magic = cpu_to_le32(DM_RAID_MAGIC);
 829         sb->features = cpu_to_le32(0);  /* No features yet */
 830
 831         sb->num_devices = cpu_to_le32(mddev->raid_disks);
 832         sb->array_position = cpu_to_le32(rdev->raid_disk);
 833
 834         sb->events = cpu_to_le64(mddev->events);
 835         sb->failed_devices = cpu_to_le64(failed_devices);
 836
 837         sb->disk_recovery_offset = cpu_to_le64(rdev->recovery_offset);
 838         sb->array_resync_offset = cpu_to_le64(mddev->recovery_cp);
 839
 840         sb->level = cpu_to_le32(mddev->level);
 841         sb->layout = cpu_to_le32(mddev->layout);
 842         sb->stripe_sectors = cpu_to_le32(mddev->chunk_sectors);
 843 }
 844
 845 /*
 846  * super_load
 847  *
 848  * This function creates a superblock if one is not found on the device
 849  * and will decide which superblock to use if there's a choice.
 850  *
 851  * Return: 1 if use rdev, 0 if use refdev, -Exxx otherwise
 852  */
 853 static int super_load(struct md_rdev *rdev, struct md_rdev *refdev)
 854 {
 855         int ret;
 856         struct dm_raid_superblock *sb;
 857         struct dm_raid_superblock *refsb;
 858         uint64_t events_sb, events_refsb;
 859
 860         rdev->sb_start = 0;
 861         rdev->sb_size = sizeof(*sb);
 862
 863         ret = read_disk_sb(rdev, rdev->sb_size);
 864         if (ret)
 865                 return ret;
 866
 867         sb = page_address(rdev->sb_page);
 868
 869         /*
 870          * Two cases that we want to write new superblocks and rebuild:
 871          * 1) New device (no matching magic number)
 872          * 2) Device specified for rebuild (!In_sync w/ offset == 0)
 873          */
 874         if ((sb->magic != cpu_to_le32(DM_RAID_MAGIC)) ||
 875             (!test_bit(In_sync, &rdev->flags) && !rdev->recovery_offset)) {
 876                 super_sync(rdev->mddev, rdev);
 877
 878                 set_bit(FirstUse, &rdev->flags);
 879
 880                 /* Force writing of superblocks to disk */
 881                 set_bit(MD_CHANGE_DEVS, &rdev->mddev->flags);
 882
 883                 /* Any superblock is better than none, choose that if given */
 884                 return refdev ? 0 : 1;
 885         }
 886
 887         if (!refdev)
 888                 return 1;
 889
 890         events_sb = le64_to_cpu(sb->events);
 891
 892         refsb = page_address(refdev->sb_page);
 893         events_refsb = le64_to_cpu(refsb->events);
 894
 895         return (events_sb > events_refsb) ? 1 : 0;
 896 }
 897
 898 static int super_init_validation(struct mddev *mddev, struct md_rdev *rdev)
 899 {
 900         int role;
 901         struct raid_set *rs = container_of(mddev, struct raid_set, md);
 902         uint64_t events_sb;
 903         uint64_t failed_devices;
 904         struct dm_raid_superblock *sb;
 905         uint32_t new_devs = 0;
 906         uint32_t rebuilds = 0;
 907         struct md_rdev *r;
 908         struct dm_raid_superblock *sb2;
 909
 910         sb = page_address(rdev->sb_page);
 911         events_sb = le64_to_cpu(sb->events);
 912         failed_devices = le64_to_cpu(sb->failed_devices);
 913
 914         /*
 915          * Initialise to 1 if this is a new superblock.
 916          */
 917         mddev->events = events_sb ? : 1;
 918
 919         /*
 920          * Reshaping is not currently allowed
 921          */
 922         if (le32_to_cpu(sb->level) != mddev->level) {
 923                 DMERR("Reshaping arrays not yet supported. (RAID level change)");
 924                 return -EINVAL;
 925         }
 926         if (le32_to_cpu(sb->layout) != mddev->layout) {
 927                 DMERR("Reshaping arrays not yet supported. (RAID layout change)");
 928                 DMERR("  0x%X vs 0x%X", le32_to_cpu(sb->layout), mddev->layout);
 929                 DMERR("  Old layout: %s w/ %d copies",
 930                       raid10_md_layout_to_format(le32_to_cpu(sb->layout)),
 931                       raid10_md_layout_to_copies(le32_to_cpu(sb->layout)));
 932                 DMERR("  New layout: %s w/ %d copies",
 933                       raid10_md_layout_to_format(mddev->layout),
 934                       raid10_md_layout_to_copies(mddev->layout));
 935                 return -EINVAL;
 936         }
 937         if (le32_to_cpu(sb->stripe_sectors) != mddev->chunk_sectors) {
 938                 DMERR("Reshaping arrays not yet supported. (stripe sectors change)");
 939                 return -EINVAL;
 940         }
 941
 942         /* We can only change the number of devices in RAID1 right now */
 943         if ((rs->raid_type->level != 1) &&
 944             (le32_to_cpu(sb->num_devices) != mddev->raid_disks)) {
 945                 DMERR("Reshaping arrays not yet supported. (device count change)");
 946                 return -EINVAL;
 947         }
 948
 949         if (!(rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC)))
 950                 mddev->recovery_cp = le64_to_cpu(sb->array_resync_offset);
 951
 952         /*
 953          * During load, we set FirstUse if a new superblock was written.
 954          * There are two reasons we might not have a superblock:
 955          * 1) The array is brand new - in which case, all of the
 956          *    devices must have their In_sync bit set.  Also,
 957          *    recovery_cp must be 0, unless forced.
 958          * 2) This is a new device being added to an old array
 959          *    and the new device needs to be rebuilt - in which
 960          *    case the In_sync bit will /not/ be set and
 961          *    recovery_cp must be MaxSector.
 962          */
 963         rdev_for_each(r, mddev) {
 964                 if (!test_bit(In_sync, &r->flags)) {
 965                         DMINFO("Device %d specified for rebuild: "
 966                                "Clearing superblock", r->raid_disk);
 967                         rebuilds++;
 968                 } else if (test_bit(FirstUse, &r->flags))
 969                         new_devs++;
 970         }
 971
 972         if (!rebuilds) {
 973                 if (new_devs == mddev->raid_disks) {
 974                         DMINFO("Superblocks created for new array");
 975                         set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
 976                 } else if (new_devs) {
 977                         DMERR("New device injected "
 978                               "into existing array without 'rebuild' "
 979                               "parameter specified");
 980                         return -EINVAL;
 981                 }
 982         } else if (new_devs) {
 983                 DMERR("'rebuild' devices cannot be "
 984                       "injected into an array with other first-time devices");
 985                 return -EINVAL;
 986         } else if (mddev->recovery_cp != MaxSector) {
 987                 DMERR("'rebuild' specified while array is not in-sync");
 988                 return -EINVAL;
 989         }
 990
 991         /*
 992          * Now we set the Faulty bit for those devices that are
 993          * recorded in the superblock as failed.
 994          */
 995         rdev_for_each(r, mddev) {
 996                 if (!r->sb_page)
 997                         continue;
 998                 sb2 = page_address(r->sb_page);
 999                 sb2->failed_devices = 0;
1000
1001                 /*
1002                  * Check for any device re-ordering.
1003                  */
1004                 if (!test_bit(FirstUse, &r->flags) && (r->raid_disk >= 0)) {
1005                         role = le32_to_cpu(sb2->array_position);
1006                         if (role != r->raid_disk) {
1007                                 if (rs->raid_type->level != 1) {
1008                                         rs->ti->error = "Cannot change device "
1009                                                 "positions in RAID array";
1010                                         return -EINVAL;
1011                                 }
1012                                 DMINFO("RAID1 device #%d now at position #%d",
1013                                        role, r->raid_disk);
1014                         }
1015
1016                         /*
1017                          * Partial recovery is performed on
1018                          * returning failed devices.
1019                          */
1020                         if (failed_devices & (1 << role))
1021                                 set_bit(Faulty, &r->flags);
1022                 }
1023         }
1024
1025         return 0;
1026 }
1027
1028 static int super_validate(struct mddev *mddev, struct md_rdev *rdev)
1029 {
1030         struct dm_raid_superblock *sb = page_address(rdev->sb_page);
1031
1032         /*
1033          * If mddev->events is not set, we know we have not yet initialized
1034          * the array.
1035          */
1036         if (!mddev->events && super_init_validation(mddev, rdev))
1037                 return -EINVAL;
1038
1039         mddev->bitmap_info.offset = 4096 >> 9; /* Enable bitmap creation */
1040         rdev->mddev->bitmap_info.default_offset = 4096 >> 9;
1041         if (!test_bit(FirstUse, &rdev->flags)) {
1042                 rdev->recovery_offset = le64_to_cpu(sb->disk_recovery_offset);
1043                 if (rdev->recovery_offset != MaxSector)
1044                         clear_bit(In_sync, &rdev->flags);
1045         }
1046
1047         /*
1048          * If a device comes back, set it as not In_sync and no longer faulty.
1049          */
1050         if (test_bit(Faulty, &rdev->flags)) {
1051                 clear_bit(Faulty, &rdev->flags);
1052                 clear_bit(In_sync, &rdev->flags);
1053                 rdev->saved_raid_disk = rdev->raid_disk;
1054                 rdev->recovery_offset = 0;
1055         }
1056
1057         clear_bit(FirstUse, &rdev->flags);
1058
1059         return 0;
1060 }
1061
1062 /*
1063  * Analyse superblocks and select the freshest.
1064  */
1065 static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
1066 {
1067         int ret;
1068         struct raid_dev *dev;
1069         struct md_rdev *rdev, *tmp, *freshest;
1070         struct mddev *mddev = &rs->md;
1071
1072         freshest = NULL;
1073         rdev_for_each_safe(rdev, tmp, mddev) {
1074                 /*
1075                  * Skipping super_load due to DMPF_SYNC will cause
1076                  * the array to undergo initialization again as
1077                  * though it were new.  This is the intended effect
1078                  * of the "sync" directive.
1079                  *
1080                  * When reshaping capability is added, we must ensure
1081                  * that the "sync" directive is disallowed during the
1082                  * reshape.
1083                  */
1084                 if (rs->print_flags & DMPF_SYNC)
1085                         continue;
1086
1087                 if (!rdev->meta_bdev)
1088                         continue;
1089
1090                 ret = super_load(rdev, freshest);
1091
1092                 switch (ret) {
1093                 case 1:
1094                         freshest = rdev;
1095                         break;
1096                 case 0:
1097                         break;
1098                 default:
1099                         dev = container_of(rdev, struct raid_dev, rdev);
1100                         if (dev->meta_dev)
1101                                 dm_put_device(ti, dev->meta_dev);
1102
1103                         dev->meta_dev = NULL;
1104                         rdev->meta_bdev = NULL;
1105
1106                         if (rdev->sb_page)
1107                                 put_page(rdev->sb_page);
1108
1109                         rdev->sb_page = NULL;
1110
1111                         rdev->sb_loaded = 0;
1112
1113                         /*
1114                          * We might be able to salvage the data device
1115                          * even though the meta device has failed.  For
1116                          * now, we behave as though '- -' had been
1117                          * set for this device in the table.
1118                          */
1119                         if (dev->data_dev)
1120                                 dm_put_device(ti, dev->data_dev);
1121
1122                         dev->data_dev = NULL;
1123                         rdev->bdev = NULL;
1124
1125                         list_del(&rdev->same_set);
1126                 }
1127         }
1128
1129         if (!freshest)
1130                 return 0;
1131
1132         if (validate_raid_redundancy(rs)) {
1133                 rs->ti->error = "Insufficient redundancy to activate array";
1134                 return -EINVAL;
1135         }
1136
1137         /*
1138          * Validation of the freshest device provides the source of
1139          * validation for the remaining devices.
1140          */
1141         ti->error = "Unable to assemble array: Invalid superblocks";
1142         if (super_validate(mddev, freshest))
1143                 return -EINVAL;
1144
1145         rdev_for_each(rdev, mddev)
1146                 if ((rdev != freshest) && super_validate(mddev, rdev))
1147                         return -EINVAL;
1148
1149         return 0;
1150 }
1151
1152 /*
1153  * Construct a RAID4/5/6 mapping:
1154  * Args:
1155  *      <raid_type> <#raid_params> <raid_params>                \
1156  *      <#raid_devs> { <meta_dev1> <dev1> .. <meta_devN> <devN> }
1157  *
1158  * <raid_params> varies by <raid_type>.  See 'parse_raid_params' for
1159  * details on possible <raid_params>.
1160  */
1161 static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
1162 {
1163         int ret;
1164         struct raid_type *rt;
1165         unsigned long num_raid_params, num_raid_devs;
1166         struct raid_set *rs = NULL;
1167
1168         /* Must have at least <raid_type> <#raid_params> */
1169         if (argc < 2) {
1170                 ti->error = "Too few arguments";
1171                 return -EINVAL;
1172         }
1173
1174         /* raid type */
1175         rt = get_raid_type(argv[0]);
1176         if (!rt) {
1177                 ti->error = "Unrecognised raid_type";
1178                 return -EINVAL;
1179         }
1180         argc--;
1181         argv++;
1182
1183         /* number of RAID parameters */
1184         if (strict_strtoul(argv[0], 10, &num_raid_params) < 0) {
1185                 ti->error = "Cannot understand number of RAID parameters";
1186                 return -EINVAL;
1187         }
1188         argc--;
1189         argv++;
1190
1191         /* Skip over RAID params for now and find out # of devices */
1192         if (num_raid_params + 1 > argc) {
1193                 ti->error = "Arguments do not agree with counts given";
1194                 return -EINVAL;
1195         }
1196
1197         if ((strict_strtoul(argv[num_raid_params], 10, &num_raid_devs) < 0) ||
1198             (num_raid_devs >= INT_MAX)) {
1199                 ti->error = "Cannot understand number of raid devices";
1200                 return -EINVAL;
1201         }
1202
1203         rs = context_alloc(ti, rt, (unsigned)num_raid_devs);
1204         if (IS_ERR(rs))
1205                 return PTR_ERR(rs);
1206
1207         ret = parse_raid_params(rs, argv, (unsigned)num_raid_params);
1208         if (ret)
1209                 goto bad;
1210
1211         ret = -EINVAL;
1212
1213         argc -= num_raid_params + 1; /* +1: we already have num_raid_devs */
1214         argv += num_raid_params + 1;
1215
1216         if (argc != (num_raid_devs * 2)) {
1217                 ti->error = "Supplied RAID devices does not match the count given";
1218                 goto bad;
1219         }
1220
1221         ret = dev_parms(rs, argv);
1222         if (ret)
1223                 goto bad;
1224
1225         rs->md.sync_super = super_sync;
1226         ret = analyse_superblocks(ti, rs);
1227         if (ret)
1228                 goto bad;
1229
1230         INIT_WORK(&rs->md.event_work, do_table_event);
1231         ti->private = rs;
1232         ti->num_flush_bios = 1;
1233
1234         mutex_lock(&rs->md.reconfig_mutex);
1235         ret = md_run(&rs->md);
1236         rs->md.in_sync = 0; /* Assume already marked dirty */
1237         mutex_unlock(&rs->md.reconfig_mutex);
1238
1239         if (ret) {
1240                 ti->error = "Fail to run raid array";
1241                 goto bad;
1242         }
1243
1244         if (ti->len != rs->md.array_sectors) {
1245                 ti->error = "Array size does not match requested target length";
1246                 ret = -EINVAL;
1247                 goto size_mismatch;
1248         }
1249         rs->callbacks.congested_fn = raid_is_congested;
1250         dm_table_add_target_callbacks(ti->table, &rs->callbacks);
1251
1252         mddev_suspend(&rs->md);
1253         return 0;
1254
1255 size_mismatch:
1256         md_stop(&rs->md);
1257 bad:
1258         context_free(rs);
1259
1260         return ret;
1261 }
1262
1263 static void raid_dtr(struct dm_target *ti)
1264 {
1265         struct raid_set *rs = ti->private;
1266
1267         list_del_init(&rs->callbacks.list);
1268         md_stop(&rs->md);
1269         context_free(rs);
1270 }
1271
1272 static int raid_map(struct dm_target *ti, struct bio *bio)
1273 {
1274         struct raid_set *rs = ti->private;
1275         struct mddev *mddev = &rs->md;
1276
1277         mddev->pers->make_request(mddev, bio);
1278
1279         return DM_MAPIO_SUBMITTED;
1280 }
1281
1282 static void raid_status(struct dm_target *ti, status_type_t type,
1283                         unsigned status_flags, char *result, unsigned maxlen)
1284 {
1285         struct raid_set *rs = ti->private;
1286         unsigned raid_param_cnt = 1; /* at least 1 for chunksize */
1287         unsigned sz = 0;
1288         int i, array_in_sync = 0;
1289         sector_t sync;
1290
1291         switch (type) {
1292         case STATUSTYPE_INFO:
1293                 DMEMIT("%s %d ", rs->raid_type->name, rs->md.raid_disks);
1294
1295                 if (test_bit(MD_RECOVERY_RUNNING, &rs->md.recovery))
1296                         sync = rs->md.curr_resync_completed;
1297                 else
1298                         sync = rs->md.recovery_cp;
1299
1300                 if (sync >= rs->md.resync_max_sectors) {
1301                         array_in_sync = 1;
1302                         sync = rs->md.resync_max_sectors;
1303                 } else {
1304                         /*
1305                          * The array may be doing an initial sync, or it may
1306                          * be rebuilding individual components.  If all the
1307                          * devices are In_sync, then it is the array that is
1308                          * being initialized.
1309                          */
1310                         for (i = 0; i < rs->md.raid_disks; i++)
1311                                 if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
1312                                         array_in_sync = 1;
1313                 }
1314                 /*
1315                  * Status characters:
1316                  *  'D' = Dead/Failed device
1317                  *  'a' = Alive but not in-sync
1318                  *  'A' = Alive and in-sync
1319                  */
1320                 for (i = 0; i < rs->md.raid_disks; i++) {
1321                         if (test_bit(Faulty, &rs->dev[i].rdev.flags))
1322                                 DMEMIT("D");
1323                         else if (!array_in_sync ||
1324                                  !test_bit(In_sync, &rs->dev[i].rdev.flags))
1325                                 DMEMIT("a");
1326                         else
1327                                 DMEMIT("A");
1328                 }
1329
1330                 /*
1331                  * In-sync ratio:
1332                  *  The in-sync ratio shows the progress of:
1333                  *   - Initializing the array
1334                  *   - Rebuilding a subset of devices of the array
1335                  *  The user can distinguish between the two by referring
1336                  *  to the status characters.
1337                  */
1338                 DMEMIT(" %llu/%llu",
1339                        (unsigned long long) sync,
1340                        (unsigned long long) rs->md.resync_max_sectors);
1341
1342                 break;
1343         case STATUSTYPE_TABLE:
1344                 /* The string you would use to construct this array */
1345                 for (i = 0; i < rs->md.raid_disks; i++) {
1346                         if ((rs->print_flags & DMPF_REBUILD) &&
1347                             rs->dev[i].data_dev &&
1348                             !test_bit(In_sync, &rs->dev[i].rdev.flags))
1349                                 raid_param_cnt += 2; /* for rebuilds */
1350                         if (rs->dev[i].data_dev &&
1351                             test_bit(WriteMostly, &rs->dev[i].rdev.flags))
1352                                 raid_param_cnt += 2;
1353                 }
1354
1355                 raid_param_cnt += (hweight32(rs->print_flags & ~DMPF_REBUILD) * 2);
1356                 if (rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC))
1357                         raid_param_cnt--;
1358
1359                 DMEMIT("%s %u %u", rs->raid_type->name,
1360                        raid_param_cnt, rs->md.chunk_sectors);
1361
1362                 if ((rs->print_flags & DMPF_SYNC) &&
1363                     (rs->md.recovery_cp == MaxSector))
1364                         DMEMIT(" sync");
1365                 if (rs->print_flags & DMPF_NOSYNC)
1366                         DMEMIT(" nosync");
1367
1368                 for (i = 0; i < rs->md.raid_disks; i++)
1369                         if ((rs->print_flags & DMPF_REBUILD) &&
1370                             rs->dev[i].data_dev &&
1371                             !test_bit(In_sync, &rs->dev[i].rdev.flags))
1372                                 DMEMIT(" rebuild %u", i);
1373
1374                 if (rs->print_flags & DMPF_DAEMON_SLEEP)
1375                         DMEMIT(" daemon_sleep %lu",
1376                                rs->md.bitmap_info.daemon_sleep);
1377
1378                 if (rs->print_flags & DMPF_MIN_RECOVERY_RATE)
1379                         DMEMIT(" min_recovery_rate %d", rs->md.sync_speed_min);
1380
1381                 if (rs->print_flags & DMPF_MAX_RECOVERY_RATE)
1382                         DMEMIT(" max_recovery_rate %d", rs->md.sync_speed_max);
1383
1384                 for (i = 0; i < rs->md.raid_disks; i++)
1385                         if (rs->dev[i].data_dev &&
1386                             test_bit(WriteMostly, &rs->dev[i].rdev.flags))
1387                                 DMEMIT(" write_mostly %u", i);
1388
1389                 if (rs->print_flags & DMPF_MAX_WRITE_BEHIND)
1390                         DMEMIT(" max_write_behind %lu",
1391                                rs->md.bitmap_info.max_write_behind);
1392
1393                 if (rs->print_flags & DMPF_STRIPE_CACHE) {
1394                         struct r5conf *conf = rs->md.private;
1395
1396                         /* convert from kiB to sectors */
1397                         DMEMIT(" stripe_cache %d",
1398                                conf ? conf->max_nr_stripes * 2 : 0);
1399                 }
1400
1401                 if (rs->print_flags & DMPF_REGION_SIZE)
1402                         DMEMIT(" region_size %lu",
1403                                rs->md.bitmap_info.chunksize >> 9);
1404
1405                 if (rs->print_flags & DMPF_RAID10_COPIES)
1406                         DMEMIT(" raid10_copies %u",
1407                                raid10_md_layout_to_copies(rs->md.layout));
1408
1409                 if (rs->print_flags & DMPF_RAID10_FORMAT)
1410                         DMEMIT(" raid10_format %s",
1411                                raid10_md_layout_to_format(rs->md.layout));
1412
1413                 DMEMIT(" %d", rs->md.raid_disks);
1414                 for (i = 0; i < rs->md.raid_disks; i++) {
1415                         if (rs->dev[i].meta_dev)
1416                                 DMEMIT(" %s", rs->dev[i].meta_dev->name);
1417                         else
1418                                 DMEMIT(" -");
1419
1420                         if (rs->dev[i].data_dev)
1421                                 DMEMIT(" %s", rs->dev[i].data_dev->name);
1422                         else
1423                                 DMEMIT(" -");
1424                 }
1425         }
1426 }
1427
1428 static int raid_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data)
1429 {
1430         struct raid_set *rs = ti->private;
1431         unsigned i;
1432         int ret = 0;
1433
1434         for (i = 0; !ret && i < rs->md.raid_disks; i++)
1435                 if (rs->dev[i].data_dev)
1436                         ret = fn(ti,
1437                                  rs->dev[i].data_dev,
1438                                  0, /* No offset on data devs */
1439                                  rs->md.dev_sectors,
1440                                  data);
1441
1442         return ret;
1443 }
1444
1445 static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
1446 {
1447         struct raid_set *rs = ti->private;
1448         unsigned chunk_size = rs->md.chunk_sectors << 9;
1449         struct r5conf *conf = rs->md.private;
1450
1451         blk_limits_io_min(limits, chunk_size);
1452         blk_limits_io_opt(limits, chunk_size * (conf->raid_disks - conf->max_degraded));
1453 }
1454
1455 static void raid_presuspend(struct dm_target *ti)
1456 {
1457         struct raid_set *rs = ti->private;
1458
1459         md_stop_writes(&rs->md);
1460 }
1461
1462 static void raid_postsuspend(struct dm_target *ti)
1463 {
1464         struct raid_set *rs = ti->private;
1465
1466         mddev_suspend(&rs->md);
1467 }
1468
1469 static void raid_resume(struct dm_target *ti)
1470 {
1471         struct raid_set *rs = ti->private;
1472
1473         set_bit(MD_CHANGE_DEVS, &rs->md.flags);
1474         if (!rs->bitmap_loaded) {
1475                 bitmap_load(&rs->md);
1476                 rs->bitmap_loaded = 1;
1477         }
1478
1479         clear_bit(MD_RECOVERY_FROZEN, &rs->md.recovery);
1480         mddev_resume(&rs->md);
1481 }
1482
1483 static struct target_type raid_target = {
1484         .name = "raid",
1485         .version = {1, 4, 2},
1486         .module = THIS_MODULE,
1487         .ctr = raid_ctr,
1488         .dtr = raid_dtr,
1489         .map = raid_map,
1490         .status = raid_status,
1491         .iterate_devices = raid_iterate_devices,
1492         .io_hints = raid_io_hints,
1493         .presuspend = raid_presuspend,
1494         .postsuspend = raid_postsuspend,
1495         .resume = raid_resume,
1496 };
1497
1498 static int __init dm_raid_init(void)
1499 {
1500         DMINFO("Loading target version %u.%u.%u",
1501                raid_target.version[0],
1502                raid_target.version[1],
1503                raid_target.version[2]);
1504         return dm_register_target(&raid_target);
1505 }
1506
1507 static void __exit dm_raid_exit(void)
1508 {
1509         dm_unregister_target(&raid_target);
1510 }
1511
1512 module_init(dm_raid_init);
1513 module_exit(dm_raid_exit);
1514
1515 MODULE_DESCRIPTION(DM_NAME " raid4/5/6 target");
1516 MODULE_ALIAS("dm-raid1");
1517 MODULE_ALIAS("dm-raid10");
1518 MODULE_ALIAS("dm-raid4");
1519 MODULE_ALIAS("dm-raid5");
1520 MODULE_ALIAS("dm-raid6");
1521 MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>");
1522 MODULE_LICENSE("GPL");