linux/drivers/md/dm-raid.c
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   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
  27struct 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
  60struct 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. */
  74static 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
  94static unsigned raid10_md_layout_to_copies(int layout)
  95{
  96        return layout & 0xFF;
  97}
  98
  99static 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
 105static 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
 116static 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
 159static 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 */
 190static 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 */
 289static int validate_region_size(struct raid_set *rs, unsigned long region_size)
 290{
 291        unsigned long min_region_size = rs->ti->len / (1 << 21);
 292
 293        if (!region_size) {
 294                /*
 295                 * Choose a reasonable default.  All figures in sectors.
 296                 */
 297                if (min_region_size > (1 << 13)) {
 298                        DMINFO("Choosing default region size of %lu sectors",
 299                               region_size);
 300                        region_size = min_region_size;
 301                } else {
 302                        DMINFO("Choosing default region size of 4MiB");
 303                        region_size = 1 << 13; /* sectors */
 304                }
 305        } else {
 306                /*
 307                 * Validate user-supplied value.
 308                 */
 309                if (region_size > rs->ti->len) {
 310                        rs->ti->error = "Supplied region size is too large";
 311                        return -EINVAL;
 312                }
 313
 314                if (region_size < min_region_size) {
 315                        DMERR("Supplied region_size (%lu sectors) below minimum (%lu)",
 316                              region_size, min_region_size);
 317                        rs->ti->error = "Supplied region size is too small";
 318                        return -EINVAL;
 319                }
 320
 321                if (!is_power_of_2(region_size)) {
 322                        rs->ti->error = "Region size is not a power of 2";
 323                        return -EINVAL;
 324                }
 325
 326                if (region_size < rs->md.chunk_sectors) {
 327                        rs->ti->error = "Region size is smaller than the chunk size";
 328                        return -EINVAL;
 329                }
 330        }
 331
 332        /*
 333         * Convert sectors to bytes.
 334         */
 335        rs->md.bitmap_info.chunksize = (region_size << 9);
 336
 337        return 0;
 338}
 339
 340/*
 341 * validate_rebuild_devices
 342 * @rs
 343 *
 344 * Determine if the devices specified for rebuild can result in a valid
 345 * usable array that is capable of rebuilding the given devices.
 346 *
 347 * Returns: 0 on success, -EINVAL on failure.
 348 */
 349static int validate_rebuild_devices(struct raid_set *rs)
 350{
 351        unsigned i, rebuild_cnt = 0;
 352        unsigned rebuilds_per_group, copies, d;
 353
 354        if (!(rs->print_flags & DMPF_REBUILD))
 355                return 0;
 356
 357        for (i = 0; i < rs->md.raid_disks; i++)
 358                if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
 359                        rebuild_cnt++;
 360
 361        switch (rs->raid_type->level) {
 362        case 1:
 363                if (rebuild_cnt >= rs->md.raid_disks)
 364                        goto too_many;
 365                break;
 366        case 4:
 367        case 5:
 368        case 6:
 369                if (rebuild_cnt > rs->raid_type->parity_devs)
 370                        goto too_many;
 371                break;
 372        case 10:
 373                copies = raid10_md_layout_to_copies(rs->md.layout);
 374                if (rebuild_cnt < copies)
 375                        break;
 376
 377                /*
 378                 * It is possible to have a higher rebuild count for RAID10,
 379                 * as long as the failed devices occur in different mirror
 380                 * groups (i.e. different stripes).
 381                 *
 382                 * Right now, we only allow for "near" copies.  When other
 383                 * formats are added, we will have to check those too.
 384                 *
 385                 * When checking "near" format, make sure no adjacent devices
 386                 * have failed beyond what can be handled.  In addition to the
 387                 * simple case where the number of devices is a multiple of the
 388                 * number of copies, we must also handle cases where the number
 389                 * of devices is not a multiple of the number of copies.
 390                 * E.g.    dev1 dev2 dev3 dev4 dev5
 391                 *          A    A    B    B    C
 392                 *          C    D    D    E    E
 393                 */
 394                rebuilds_per_group = 0;
 395                for (i = 0; i < rs->md.raid_disks * copies; i++) {
 396                        d = i % rs->md.raid_disks;
 397                        if (!test_bit(In_sync, &rs->dev[d].rdev.flags) &&
 398                            (++rebuilds_per_group >= copies))
 399                                goto too_many;
 400                        if (!((i + 1) % copies))
 401                                rebuilds_per_group = 0;
 402                }
 403                break;
 404        default:
 405                DMERR("The rebuild parameter is not supported for %s",
 406                      rs->raid_type->name);
 407                rs->ti->error = "Rebuild not supported for this RAID type";
 408                return -EINVAL;
 409        }
 410
 411        return 0;
 412
 413too_many:
 414        rs->ti->error = "Too many rebuild devices specified";
 415        return -EINVAL;
 416}
 417
 418/*
 419 * Possible arguments are...
 420 *      <chunk_size> [optional_args]
 421 *
 422 * Argument definitions
 423 *    <chunk_size>                      The number of sectors per disk that
 424 *                                      will form the "stripe"
 425 *    [[no]sync]                        Force or prevent recovery of the
 426 *                                      entire array
 427 *    [rebuild <idx>]                   Rebuild the drive indicated by the index
 428 *    [daemon_sleep <ms>]               Time between bitmap daemon work to
 429 *                                      clear bits
 430 *    [min_recovery_rate <kB/sec/disk>] Throttle RAID initialization
 431 *    [max_recovery_rate <kB/sec/disk>] Throttle RAID initialization
 432 *    [write_mostly <idx>]              Indicate a write mostly drive via index
 433 *    [max_write_behind <sectors>]      See '-write-behind=' (man mdadm)
 434 *    [stripe_cache <sectors>]          Stripe cache size for higher RAIDs
 435 *    [region_size <sectors>]           Defines granularity of bitmap
 436 *
 437 * RAID10-only options:
 438 *    [raid10_copies <# copies>]        Number of copies.  (Default: 2)
 439 *    [raid10_format <near>]            Layout algorithm.  (Default: near)
 440 */
 441static int parse_raid_params(struct raid_set *rs, char **argv,
 442                             unsigned num_raid_params)
 443{
 444        char *raid10_format = "near";
 445        unsigned raid10_copies = 2;
 446        unsigned i;
 447        unsigned long value, region_size = 0;
 448        sector_t sectors_per_dev = rs->ti->len;
 449        sector_t max_io_len;
 450        char *key;
 451
 452        /*
 453         * First, parse the in-order required arguments
 454         * "chunk_size" is the only argument of this type.
 455         */
 456        if ((strict_strtoul(argv[0], 10, &value) < 0)) {
 457                rs->ti->error = "Bad chunk size";
 458                return -EINVAL;
 459        } else if (rs->raid_type->level == 1) {
 460                if (value)
 461                        DMERR("Ignoring chunk size parameter for RAID 1");
 462                value = 0;
 463        } else if (!is_power_of_2(value)) {
 464                rs->ti->error = "Chunk size must be a power of 2";
 465                return -EINVAL;
 466        } else if (value < 8) {
 467                rs->ti->error = "Chunk size value is too small";
 468                return -EINVAL;
 469        }
 470
 471        rs->md.new_chunk_sectors = rs->md.chunk_sectors = value;
 472        argv++;
 473        num_raid_params--;
 474
 475        /*
 476         * We set each individual device as In_sync with a completed
 477         * 'recovery_offset'.  If there has been a device failure or
 478         * replacement then one of the following cases applies:
 479         *
 480         *   1) User specifies 'rebuild'.
 481         *      - Device is reset when param is read.
 482         *   2) A new device is supplied.
 483         *      - No matching superblock found, resets device.
 484         *   3) Device failure was transient and returns on reload.
 485         *      - Failure noticed, resets device for bitmap replay.
 486         *   4) Device hadn't completed recovery after previous failure.
 487         *      - Superblock is read and overrides recovery_offset.
 488         *
 489         * What is found in the superblocks of the devices is always
 490         * authoritative, unless 'rebuild' or '[no]sync' was specified.
 491         */
 492        for (i = 0; i < rs->md.raid_disks; i++) {
 493                set_bit(In_sync, &rs->dev[i].rdev.flags);
 494                rs->dev[i].rdev.recovery_offset = MaxSector;
 495        }
 496
 497        /*
 498         * Second, parse the unordered optional arguments
 499         */
 500        for (i = 0; i < num_raid_params; i++) {
 501                if (!strcasecmp(argv[i], "nosync")) {
 502                        rs->md.recovery_cp = MaxSector;
 503                        rs->print_flags |= DMPF_NOSYNC;
 504                        continue;
 505                }
 506                if (!strcasecmp(argv[i], "sync")) {
 507                        rs->md.recovery_cp = 0;
 508                        rs->print_flags |= DMPF_SYNC;
 509                        continue;
 510                }
 511
 512                /* The rest of the optional arguments come in key/value pairs */
 513                if ((i + 1) >= num_raid_params) {
 514                        rs->ti->error = "Wrong number of raid parameters given";
 515                        return -EINVAL;
 516                }
 517
 518                key = argv[i++];
 519
 520                /* Parameters that take a string value are checked here. */
 521                if (!strcasecmp(key, "raid10_format")) {
 522                        if (rs->raid_type->level != 10) {
 523                                rs->ti->error = "'raid10_format' is an invalid parameter for this RAID type";
 524                                return -EINVAL;
 525                        }
 526                        if (strcmp("near", argv[i])) {
 527                                rs->ti->error = "Invalid 'raid10_format' value given";
 528                                return -EINVAL;
 529                        }
 530                        raid10_format = argv[i];
 531                        rs->print_flags |= DMPF_RAID10_FORMAT;
 532                        continue;
 533                }
 534
 535                if (strict_strtoul(argv[i], 10, &value) < 0) {
 536                        rs->ti->error = "Bad numerical argument given in raid params";
 537                        return -EINVAL;
 538                }
 539
 540                /* Parameters that take a numeric value are checked here */
 541                if (!strcasecmp(key, "rebuild")) {
 542                        if (value >= rs->md.raid_disks) {
 543                                rs->ti->error = "Invalid rebuild index given";
 544                                return -EINVAL;
 545                        }
 546                        clear_bit(In_sync, &rs->dev[value].rdev.flags);
 547                        rs->dev[value].rdev.recovery_offset = 0;
 548                        rs->print_flags |= DMPF_REBUILD;
 549                } else if (!strcasecmp(key, "write_mostly")) {
 550                        if (rs->raid_type->level != 1) {
 551                                rs->ti->error = "write_mostly option is only valid for RAID1";
 552                                return -EINVAL;
 553                        }
 554                        if (value >= rs->md.raid_disks) {
 555                                rs->ti->error = "Invalid write_mostly drive index given";
 556                                return -EINVAL;
 557                        }
 558                        set_bit(WriteMostly, &rs->dev[value].rdev.flags);
 559                } else if (!strcasecmp(key, "max_write_behind")) {
 560                        if (rs->raid_type->level != 1) {
 561                                rs->ti->error = "max_write_behind option is only valid for RAID1";
 562                                return -EINVAL;
 563                        }
 564                        rs->print_flags |= DMPF_MAX_WRITE_BEHIND;
 565
 566                        /*
 567                         * In device-mapper, we specify things in sectors, but
 568                         * MD records this value in kB
 569                         */
 570                        value /= 2;
 571                        if (value > COUNTER_MAX) {
 572                                rs->ti->error = "Max write-behind limit out of range";
 573                                return -EINVAL;
 574                        }
 575                        rs->md.bitmap_info.max_write_behind = value;
 576                } else if (!strcasecmp(key, "daemon_sleep")) {
 577                        rs->print_flags |= DMPF_DAEMON_SLEEP;
 578                        if (!value || (value > MAX_SCHEDULE_TIMEOUT)) {
 579                                rs->ti->error = "daemon sleep period out of range";
 580                                return -EINVAL;
 581                        }
 582                        rs->md.bitmap_info.daemon_sleep = value;
 583                } else if (!strcasecmp(key, "stripe_cache")) {
 584                        rs->print_flags |= DMPF_STRIPE_CACHE;
 585
 586                        /*
 587                         * In device-mapper, we specify things in sectors, but
 588                         * MD records this value in kB
 589                         */
 590                        value /= 2;
 591
 592                        if ((rs->raid_type->level != 5) &&
 593                            (rs->raid_type->level != 6)) {
 594                                rs->ti->error = "Inappropriate argument: stripe_cache";
 595                                return -EINVAL;
 596                        }
 597                        if (raid5_set_cache_size(&rs->md, (int)value)) {
 598                                rs->ti->error = "Bad stripe_cache size";
 599                                return -EINVAL;
 600                        }
 601                } else if (!strcasecmp(key, "min_recovery_rate")) {
 602                        rs->print_flags |= DMPF_MIN_RECOVERY_RATE;
 603                        if (value > INT_MAX) {
 604                                rs->ti->error = "min_recovery_rate out of range";
 605                                return -EINVAL;
 606                        }
 607                        rs->md.sync_speed_min = (int)value;
 608                } else if (!strcasecmp(key, "max_recovery_rate")) {
 609                        rs->print_flags |= DMPF_MAX_RECOVERY_RATE;
 610                        if (value > INT_MAX) {
 611                                rs->ti->error = "max_recovery_rate out of range";
 612                                return -EINVAL;
 613                        }
 614                        rs->md.sync_speed_max = (int)value;
 615                } else if (!strcasecmp(key, "region_size")) {
 616                        rs->print_flags |= DMPF_REGION_SIZE;
 617                        region_size = value;
 618                } else if (!strcasecmp(key, "raid10_copies") &&
 619                           (rs->raid_type->level == 10)) {
 620                        if ((value < 2) || (value > 0xFF)) {
 621                                rs->ti->error = "Bad value for 'raid10_copies'";
 622                                return -EINVAL;
 623                        }
 624                        rs->print_flags |= DMPF_RAID10_COPIES;
 625                        raid10_copies = value;
 626                } else {
 627                        DMERR("Unable to parse RAID parameter: %s", key);
 628                        rs->ti->error = "Unable to parse RAID parameters";
 629                        return -EINVAL;
 630                }
 631        }
 632
 633        if (validate_region_size(rs, region_size))
 634                return -EINVAL;
 635
 636        if (rs->md.chunk_sectors)
 637                max_io_len = rs->md.chunk_sectors;
 638        else
 639                max_io_len = region_size;
 640
 641        if (dm_set_target_max_io_len(rs->ti, max_io_len))
 642                return -EINVAL;
 643
 644        if (rs->raid_type->level == 10) {
 645                if (raid10_copies > rs->md.raid_disks) {
 646                        rs->ti->error = "Not enough devices to satisfy specification";
 647                        return -EINVAL;
 648                }
 649
 650                /* (Len * #mirrors) / #devices */
 651                sectors_per_dev = rs->ti->len * raid10_copies;
 652                sector_div(sectors_per_dev, rs->md.raid_disks);
 653
 654                rs->md.layout = raid10_format_to_md_layout(raid10_format,
 655                                                           raid10_copies);
 656                rs->md.new_layout = rs->md.layout;
 657        } else if ((rs->raid_type->level > 1) &&
 658                   sector_div(sectors_per_dev,
 659                              (rs->md.raid_disks - rs->raid_type->parity_devs))) {
 660                rs->ti->error = "Target length not divisible by number of data devices";
 661                return -EINVAL;
 662        }
 663        rs->md.dev_sectors = sectors_per_dev;
 664
 665        if (validate_rebuild_devices(rs))
 666                return -EINVAL;
 667
 668        /* Assume there are no metadata devices until the drives are parsed */
 669        rs->md.persistent = 0;
 670        rs->md.external = 1;
 671
 672        return 0;
 673}
 674
 675static void do_table_event(struct work_struct *ws)
 676{
 677        struct raid_set *rs = container_of(ws, struct raid_set, md.event_work);
 678
 679        dm_table_event(rs->ti->table);
 680}
 681
 682static int raid_is_congested(struct dm_target_callbacks *cb, int bits)
 683{
 684        struct raid_set *rs = container_of(cb, struct raid_set, callbacks);
 685
 686        if (rs->raid_type->level == 1)
 687                return md_raid1_congested(&rs->md, bits);
 688
 689        if (rs->raid_type->level == 10)
 690                return md_raid10_congested(&rs->md, bits);
 691
 692        return md_raid5_congested(&rs->md, bits);
 693}
 694
 695/*
 696 * This structure is never routinely used by userspace, unlike md superblocks.
 697 * Devices with this superblock should only ever be accessed via device-mapper.
 698 */
 699#define DM_RAID_MAGIC 0x64526D44
 700struct dm_raid_superblock {
 701        __le32 magic;           /* "DmRd" */
 702        __le32 features;        /* Used to indicate possible future changes */
 703
 704        __le32 num_devices;     /* Number of devices in this array. (Max 64) */
 705        __le32 array_position;  /* The position of this drive in the array */
 706
 707        __le64 events;          /* Incremented by md when superblock updated */
 708        __le64 failed_devices;  /* Bit field of devices to indicate failures */
 709
 710        /*
 711         * This offset tracks the progress of the repair or replacement of
 712         * an individual drive.
 713         */
 714        __le64 disk_recovery_offset;
 715
 716        /*
 717         * This offset tracks the progress of the initial array
 718         * synchronisation/parity calculation.
 719         */
 720        __le64 array_resync_offset;
 721
 722        /*
 723         * RAID characteristics
 724         */
 725        __le32 level;
 726        __le32 layout;
 727        __le32 stripe_sectors;
 728
 729        __u8 pad[452];          /* Round struct to 512 bytes. */
 730                                /* Always set to 0 when writing. */
 731} __packed;
 732
 733static int read_disk_sb(struct md_rdev *rdev, int size)
 734{
 735        BUG_ON(!rdev->sb_page);
 736
 737        if (rdev->sb_loaded)
 738                return 0;
 739
 740        if (!sync_page_io(rdev, 0, size, rdev->sb_page, READ, 1)) {
 741                DMERR("Failed to read superblock of device at position %d",
 742                      rdev->raid_disk);
 743                md_error(rdev->mddev, rdev);
 744                return -EINVAL;
 745        }
 746
 747        rdev->sb_loaded = 1;
 748
 749        return 0;
 750}
 751
 752static void super_sync(struct mddev *mddev, struct md_rdev *rdev)
 753{
 754        int i;
 755        uint64_t failed_devices;
 756        struct dm_raid_superblock *sb;
 757        struct raid_set *rs = container_of(mddev, struct raid_set, md);
 758
 759        sb = page_address(rdev->sb_page);
 760        failed_devices = le64_to_cpu(sb->failed_devices);
 761
 762        for (i = 0; i < mddev->raid_disks; i++)
 763                if (!rs->dev[i].data_dev ||
 764                    test_bit(Faulty, &(rs->dev[i].rdev.flags)))
 765                        failed_devices |= (1ULL << i);
 766
 767        memset(sb, 0, sizeof(*sb));
 768
 769        sb->magic = cpu_to_le32(DM_RAID_MAGIC);
 770        sb->features = cpu_to_le32(0);  /* No features yet */
 771
 772        sb->num_devices = cpu_to_le32(mddev->raid_disks);
 773        sb->array_position = cpu_to_le32(rdev->raid_disk);
 774
 775        sb->events = cpu_to_le64(mddev->events);
 776        sb->failed_devices = cpu_to_le64(failed_devices);
 777
 778        sb->disk_recovery_offset = cpu_to_le64(rdev->recovery_offset);
 779        sb->array_resync_offset = cpu_to_le64(mddev->recovery_cp);
 780
 781        sb->level = cpu_to_le32(mddev->level);
 782        sb->layout = cpu_to_le32(mddev->layout);
 783        sb->stripe_sectors = cpu_to_le32(mddev->chunk_sectors);
 784}
 785
 786/*
 787 * super_load
 788 *
 789 * This function creates a superblock if one is not found on the device
 790 * and will decide which superblock to use if there's a choice.
 791 *
 792 * Return: 1 if use rdev, 0 if use refdev, -Exxx otherwise
 793 */
 794static int super_load(struct md_rdev *rdev, struct md_rdev *refdev)
 795{
 796        int ret;
 797        struct dm_raid_superblock *sb;
 798        struct dm_raid_superblock *refsb;
 799        uint64_t events_sb, events_refsb;
 800
 801        rdev->sb_start = 0;
 802        rdev->sb_size = sizeof(*sb);
 803
 804        ret = read_disk_sb(rdev, rdev->sb_size);
 805        if (ret)
 806                return ret;
 807
 808        sb = page_address(rdev->sb_page);
 809
 810        /*
 811         * Two cases that we want to write new superblocks and rebuild:
 812         * 1) New device (no matching magic number)
 813         * 2) Device specified for rebuild (!In_sync w/ offset == 0)
 814         */
 815        if ((sb->magic != cpu_to_le32(DM_RAID_MAGIC)) ||
 816            (!test_bit(In_sync, &rdev->flags) && !rdev->recovery_offset)) {
 817                super_sync(rdev->mddev, rdev);
 818
 819                set_bit(FirstUse, &rdev->flags);
 820
 821                /* Force writing of superblocks to disk */
 822                set_bit(MD_CHANGE_DEVS, &rdev->mddev->flags);
 823
 824                /* Any superblock is better than none, choose that if given */
 825                return refdev ? 0 : 1;
 826        }
 827
 828        if (!refdev)
 829                return 1;
 830
 831        events_sb = le64_to_cpu(sb->events);
 832
 833        refsb = page_address(refdev->sb_page);
 834        events_refsb = le64_to_cpu(refsb->events);
 835
 836        return (events_sb > events_refsb) ? 1 : 0;
 837}
 838
 839static int super_init_validation(struct mddev *mddev, struct md_rdev *rdev)
 840{
 841        int role;
 842        struct raid_set *rs = container_of(mddev, struct raid_set, md);
 843        uint64_t events_sb;
 844        uint64_t failed_devices;
 845        struct dm_raid_superblock *sb;
 846        uint32_t new_devs = 0;
 847        uint32_t rebuilds = 0;
 848        struct md_rdev *r;
 849        struct dm_raid_superblock *sb2;
 850
 851        sb = page_address(rdev->sb_page);
 852        events_sb = le64_to_cpu(sb->events);
 853        failed_devices = le64_to_cpu(sb->failed_devices);
 854
 855        /*
 856         * Initialise to 1 if this is a new superblock.
 857         */
 858        mddev->events = events_sb ? : 1;
 859
 860        /*
 861         * Reshaping is not currently allowed
 862         */
 863        if ((le32_to_cpu(sb->level) != mddev->level) ||
 864            (le32_to_cpu(sb->layout) != mddev->layout) ||
 865            (le32_to_cpu(sb->stripe_sectors) != mddev->chunk_sectors)) {
 866                DMERR("Reshaping arrays not yet supported.");
 867                return -EINVAL;
 868        }
 869
 870        /* We can only change the number of devices in RAID1 right now */
 871        if ((rs->raid_type->level != 1) &&
 872            (le32_to_cpu(sb->num_devices) != mddev->raid_disks)) {
 873                DMERR("Reshaping arrays not yet supported.");
 874                return -EINVAL;
 875        }
 876
 877        if (!(rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC)))
 878                mddev->recovery_cp = le64_to_cpu(sb->array_resync_offset);
 879
 880        /*
 881         * During load, we set FirstUse if a new superblock was written.
 882         * There are two reasons we might not have a superblock:
 883         * 1) The array is brand new - in which case, all of the
 884         *    devices must have their In_sync bit set.  Also,
 885         *    recovery_cp must be 0, unless forced.
 886         * 2) This is a new device being added to an old array
 887         *    and the new device needs to be rebuilt - in which
 888         *    case the In_sync bit will /not/ be set and
 889         *    recovery_cp must be MaxSector.
 890         */
 891        rdev_for_each(r, mddev) {
 892                if (!test_bit(In_sync, &r->flags)) {
 893                        DMINFO("Device %d specified for rebuild: "
 894                               "Clearing superblock", r->raid_disk);
 895                        rebuilds++;
 896                } else if (test_bit(FirstUse, &r->flags))
 897                        new_devs++;
 898        }
 899
 900        if (!rebuilds) {
 901                if (new_devs == mddev->raid_disks) {
 902                        DMINFO("Superblocks created for new array");
 903                        set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
 904                } else if (new_devs) {
 905                        DMERR("New device injected "
 906                              "into existing array without 'rebuild' "
 907                              "parameter specified");
 908                        return -EINVAL;
 909                }
 910        } else if (new_devs) {
 911                DMERR("'rebuild' devices cannot be "
 912                      "injected into an array with other first-time devices");
 913                return -EINVAL;
 914        } else if (mddev->recovery_cp != MaxSector) {
 915                DMERR("'rebuild' specified while array is not in-sync");
 916                return -EINVAL;
 917        }
 918
 919        /*
 920         * Now we set the Faulty bit for those devices that are
 921         * recorded in the superblock as failed.
 922         */
 923        rdev_for_each(r, mddev) {
 924                if (!r->sb_page)
 925                        continue;
 926                sb2 = page_address(r->sb_page);
 927                sb2->failed_devices = 0;
 928
 929                /*
 930                 * Check for any device re-ordering.
 931                 */
 932                if (!test_bit(FirstUse, &r->flags) && (r->raid_disk >= 0)) {
 933                        role = le32_to_cpu(sb2->array_position);
 934                        if (role != r->raid_disk) {
 935                                if (rs->raid_type->level != 1) {
 936                                        rs->ti->error = "Cannot change device "
 937                                                "positions in RAID array";
 938                                        return -EINVAL;
 939                                }
 940                                DMINFO("RAID1 device #%d now at position #%d",
 941                                       role, r->raid_disk);
 942                        }
 943
 944                        /*
 945                         * Partial recovery is performed on
 946                         * returning failed devices.
 947                         */
 948                        if (failed_devices & (1 << role))
 949                                set_bit(Faulty, &r->flags);
 950                }
 951        }
 952
 953        return 0;
 954}
 955
 956static int super_validate(struct mddev *mddev, struct md_rdev *rdev)
 957{
 958        struct dm_raid_superblock *sb = page_address(rdev->sb_page);
 959
 960        /*
 961         * If mddev->events is not set, we know we have not yet initialized
 962         * the array.
 963         */
 964        if (!mddev->events && super_init_validation(mddev, rdev))
 965                return -EINVAL;
 966
 967        mddev->bitmap_info.offset = 4096 >> 9; /* Enable bitmap creation */
 968        rdev->mddev->bitmap_info.default_offset = 4096 >> 9;
 969        if (!test_bit(FirstUse, &rdev->flags)) {
 970                rdev->recovery_offset = le64_to_cpu(sb->disk_recovery_offset);
 971                if (rdev->recovery_offset != MaxSector)
 972                        clear_bit(In_sync, &rdev->flags);
 973        }
 974
 975        /*
 976         * If a device comes back, set it as not In_sync and no longer faulty.
 977         */
 978        if (test_bit(Faulty, &rdev->flags)) {
 979                clear_bit(Faulty, &rdev->flags);
 980                clear_bit(In_sync, &rdev->flags);
 981                rdev->saved_raid_disk = rdev->raid_disk;
 982                rdev->recovery_offset = 0;
 983        }
 984
 985        clear_bit(FirstUse, &rdev->flags);
 986
 987        return 0;
 988}
 989
 990/*
 991 * Analyse superblocks and select the freshest.
 992 */
 993static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
 994{
 995        int ret;
 996        unsigned redundancy = 0;
 997        struct raid_dev *dev;
 998        struct md_rdev *rdev, *tmp, *freshest;
 999        struct mddev *mddev = &rs->md;
1000
1001        switch (rs->raid_type->level) {
1002        case 1:
1003                redundancy = rs->md.raid_disks - 1;
1004                break;
1005        case 4:
1006        case 5:
1007        case 6:
1008                redundancy = rs->raid_type->parity_devs;
1009                break;
1010        case 10:
1011                redundancy = raid10_md_layout_to_copies(mddev->layout) - 1;
1012                break;
1013        default:
1014                ti->error = "Unknown RAID type";
1015                return -EINVAL;
1016        }
1017
1018        freshest = NULL;
1019        rdev_for_each_safe(rdev, tmp, mddev) {
1020                /*
1021                 * Skipping super_load due to DMPF_SYNC will cause
1022                 * the array to undergo initialization again as
1023                 * though it were new.  This is the intended effect
1024                 * of the "sync" directive.
1025                 *
1026                 * When reshaping capability is added, we must ensure
1027                 * that the "sync" directive is disallowed during the
1028                 * reshape.
1029                 */
1030                if (rs->print_flags & DMPF_SYNC)
1031                        continue;
1032
1033                if (!rdev->meta_bdev)
1034                        continue;
1035
1036                ret = super_load(rdev, freshest);
1037
1038                switch (ret) {
1039                case 1:
1040                        freshest = rdev;
1041                        break;
1042                case 0:
1043                        break;
1044                default:
1045                        dev = container_of(rdev, struct raid_dev, rdev);
1046                        if (redundancy--) {
1047                                if (dev->meta_dev)
1048                                        dm_put_device(ti, dev->meta_dev);
1049
1050                                dev->meta_dev = NULL;
1051                                rdev->meta_bdev = NULL;
1052
1053                                if (rdev->sb_page)
1054                                        put_page(rdev->sb_page);
1055
1056                                rdev->sb_page = NULL;
1057
1058                                rdev->sb_loaded = 0;
1059
1060                                /*
1061                                 * We might be able to salvage the data device
1062                                 * even though the meta device has failed.  For
1063                                 * now, we behave as though '- -' had been
1064                                 * set for this device in the table.
1065                                 */
1066                                if (dev->data_dev)
1067                                        dm_put_device(ti, dev->data_dev);
1068
1069                                dev->data_dev = NULL;
1070                                rdev->bdev = NULL;
1071
1072                                list_del(&rdev->same_set);
1073
1074                                continue;
1075                        }
1076                        ti->error = "Failed to load superblock";
1077                        return ret;
1078                }
1079        }
1080
1081        if (!freshest)
1082                return 0;
1083
1084        /*
1085         * Validation of the freshest device provides the source of
1086         * validation for the remaining devices.
1087         */
1088        ti->error = "Unable to assemble array: Invalid superblocks";
1089        if (super_validate(mddev, freshest))
1090                return -EINVAL;
1091
1092        rdev_for_each(rdev, mddev)
1093                if ((rdev != freshest) && super_validate(mddev, rdev))
1094                        return -EINVAL;
1095
1096        return 0;
1097}
1098
1099/*
1100 * Construct a RAID4/5/6 mapping:
1101 * Args:
1102 *      <raid_type> <#raid_params> <raid_params>                \
1103 *      <#raid_devs> { <meta_dev1> <dev1> .. <meta_devN> <devN> }
1104 *
1105 * <raid_params> varies by <raid_type>.  See 'parse_raid_params' for
1106 * details on possible <raid_params>.
1107 */
1108static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
1109{
1110        int ret;
1111        struct raid_type *rt;
1112        unsigned long num_raid_params, num_raid_devs;
1113        struct raid_set *rs = NULL;
1114
1115        /* Must have at least <raid_type> <#raid_params> */
1116        if (argc < 2) {
1117                ti->error = "Too few arguments";
1118                return -EINVAL;
1119        }
1120
1121        /* raid type */
1122        rt = get_raid_type(argv[0]);
1123        if (!rt) {
1124                ti->error = "Unrecognised raid_type";
1125                return -EINVAL;
1126        }
1127        argc--;
1128        argv++;
1129
1130        /* number of RAID parameters */
1131        if (strict_strtoul(argv[0], 10, &num_raid_params) < 0) {
1132                ti->error = "Cannot understand number of RAID parameters";
1133                return -EINVAL;
1134        }
1135        argc--;
1136        argv++;
1137
1138        /* Skip over RAID params for now and find out # of devices */
1139        if (num_raid_params + 1 > argc) {
1140                ti->error = "Arguments do not agree with counts given";
1141                return -EINVAL;
1142        }
1143
1144        if ((strict_strtoul(argv[num_raid_params], 10, &num_raid_devs) < 0) ||
1145            (num_raid_devs >= INT_MAX)) {
1146                ti->error = "Cannot understand number of raid devices";
1147                return -EINVAL;
1148        }
1149
1150        rs = context_alloc(ti, rt, (unsigned)num_raid_devs);
1151        if (IS_ERR(rs))
1152                return PTR_ERR(rs);
1153
1154        ret = parse_raid_params(rs, argv, (unsigned)num_raid_params);
1155        if (ret)
1156                goto bad;
1157
1158        ret = -EINVAL;
1159
1160        argc -= num_raid_params + 1; /* +1: we already have num_raid_devs */
1161        argv += num_raid_params + 1;
1162
1163        if (argc != (num_raid_devs * 2)) {
1164                ti->error = "Supplied RAID devices does not match the count given";
1165                goto bad;
1166        }
1167
1168        ret = dev_parms(rs, argv);
1169        if (ret)
1170                goto bad;
1171
1172        rs->md.sync_super = super_sync;
1173        ret = analyse_superblocks(ti, rs);
1174        if (ret)
1175                goto bad;
1176
1177        INIT_WORK(&rs->md.event_work, do_table_event);
1178        ti->private = rs;
1179        ti->num_flush_requests = 1;
1180
1181        mutex_lock(&rs->md.reconfig_mutex);
1182        ret = md_run(&rs->md);
1183        rs->md.in_sync = 0; /* Assume already marked dirty */
1184        mutex_unlock(&rs->md.reconfig_mutex);
1185
1186        if (ret) {
1187                ti->error = "Fail to run raid array";
1188                goto bad;
1189        }
1190
1191        if (ti->len != rs->md.array_sectors) {
1192                ti->error = "Array size does not match requested target length";
1193                ret = -EINVAL;
1194                goto size_mismatch;
1195        }
1196        rs->callbacks.congested_fn = raid_is_congested;
1197        dm_table_add_target_callbacks(ti->table, &rs->callbacks);
1198
1199        mddev_suspend(&rs->md);
1200        return 0;
1201
1202size_mismatch:
1203        md_stop(&rs->md);
1204bad:
1205        context_free(rs);
1206
1207        return ret;
1208}
1209
1210static void raid_dtr(struct dm_target *ti)
1211{
1212        struct raid_set *rs = ti->private;
1213
1214        list_del_init(&rs->callbacks.list);
1215        md_stop(&rs->md);
1216        context_free(rs);
1217}
1218
1219static int raid_map(struct dm_target *ti, struct bio *bio, union map_info *map_context)
1220{
1221        struct raid_set *rs = ti->private;
1222        struct mddev *mddev = &rs->md;
1223
1224        mddev->pers->make_request(mddev, bio);
1225
1226        return DM_MAPIO_SUBMITTED;
1227}
1228
1229static int raid_status(struct dm_target *ti, status_type_t type,
1230                       unsigned status_flags, char *result, unsigned maxlen)
1231{
1232        struct raid_set *rs = ti->private;
1233        unsigned raid_param_cnt = 1; /* at least 1 for chunksize */
1234        unsigned sz = 0;
1235        int i, array_in_sync = 0;
1236        sector_t sync;
1237
1238        switch (type) {
1239        case STATUSTYPE_INFO:
1240                DMEMIT("%s %d ", rs->raid_type->name, rs->md.raid_disks);
1241
1242                if (test_bit(MD_RECOVERY_RUNNING, &rs->md.recovery))
1243                        sync = rs->md.curr_resync_completed;
1244                else
1245                        sync = rs->md.recovery_cp;
1246
1247                if (sync >= rs->md.resync_max_sectors) {
1248                        array_in_sync = 1;
1249                        sync = rs->md.resync_max_sectors;
1250                } else {
1251                        /*
1252                         * The array may be doing an initial sync, or it may
1253                         * be rebuilding individual components.  If all the
1254                         * devices are In_sync, then it is the array that is
1255                         * being initialized.
1256                         */
1257                        for (i = 0; i < rs->md.raid_disks; i++)
1258                                if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
1259                                        array_in_sync = 1;
1260                }
1261                /*
1262                 * Status characters:
1263                 *  'D' = Dead/Failed device
1264                 *  'a' = Alive but not in-sync
1265                 *  'A' = Alive and in-sync
1266                 */
1267                for (i = 0; i < rs->md.raid_disks; i++) {
1268                        if (test_bit(Faulty, &rs->dev[i].rdev.flags))
1269                                DMEMIT("D");
1270                        else if (!array_in_sync ||
1271                                 !test_bit(In_sync, &rs->dev[i].rdev.flags))
1272                                DMEMIT("a");
1273                        else
1274                                DMEMIT("A");
1275                }
1276
1277                /*
1278                 * In-sync ratio:
1279                 *  The in-sync ratio shows the progress of:
1280                 *   - Initializing the array
1281                 *   - Rebuilding a subset of devices of the array
1282                 *  The user can distinguish between the two by referring
1283                 *  to the status characters.
1284                 */
1285                DMEMIT(" %llu/%llu",
1286                       (unsigned long long) sync,
1287                       (unsigned long long) rs->md.resync_max_sectors);
1288
1289                break;
1290        case STATUSTYPE_TABLE:
1291                /* The string you would use to construct this array */
1292                for (i = 0; i < rs->md.raid_disks; i++) {
1293                        if ((rs->print_flags & DMPF_REBUILD) &&
1294                            rs->dev[i].data_dev &&
1295                            !test_bit(In_sync, &rs->dev[i].rdev.flags))
1296                                raid_param_cnt += 2; /* for rebuilds */
1297                        if (rs->dev[i].data_dev &&
1298                            test_bit(WriteMostly, &rs->dev[i].rdev.flags))
1299                                raid_param_cnt += 2;
1300                }
1301
1302                raid_param_cnt += (hweight32(rs->print_flags & ~DMPF_REBUILD) * 2);
1303                if (rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC))
1304                        raid_param_cnt--;
1305
1306                DMEMIT("%s %u %u", rs->raid_type->name,
1307                       raid_param_cnt, rs->md.chunk_sectors);
1308
1309                if ((rs->print_flags & DMPF_SYNC) &&
1310                    (rs->md.recovery_cp == MaxSector))
1311                        DMEMIT(" sync");
1312                if (rs->print_flags & DMPF_NOSYNC)
1313                        DMEMIT(" nosync");
1314
1315                for (i = 0; i < rs->md.raid_disks; i++)
1316                        if ((rs->print_flags & DMPF_REBUILD) &&
1317                            rs->dev[i].data_dev &&
1318                            !test_bit(In_sync, &rs->dev[i].rdev.flags))
1319                                DMEMIT(" rebuild %u", i);
1320
1321                if (rs->print_flags & DMPF_DAEMON_SLEEP)
1322                        DMEMIT(" daemon_sleep %lu",
1323                               rs->md.bitmap_info.daemon_sleep);
1324
1325                if (rs->print_flags & DMPF_MIN_RECOVERY_RATE)
1326                        DMEMIT(" min_recovery_rate %d", rs->md.sync_speed_min);
1327
1328                if (rs->print_flags & DMPF_MAX_RECOVERY_RATE)
1329                        DMEMIT(" max_recovery_rate %d", rs->md.sync_speed_max);
1330
1331                for (i = 0; i < rs->md.raid_disks; i++)
1332                        if (rs->dev[i].data_dev &&
1333                            test_bit(WriteMostly, &rs->dev[i].rdev.flags))
1334                                DMEMIT(" write_mostly %u", i);
1335
1336                if (rs->print_flags & DMPF_MAX_WRITE_BEHIND)
1337                        DMEMIT(" max_write_behind %lu",
1338                               rs->md.bitmap_info.max_write_behind);
1339
1340                if (rs->print_flags & DMPF_STRIPE_CACHE) {
1341                        struct r5conf *conf = rs->md.private;
1342
1343                        /* convert from kiB to sectors */
1344                        DMEMIT(" stripe_cache %d",
1345                               conf ? conf->max_nr_stripes * 2 : 0);
1346                }
1347
1348                if (rs->print_flags & DMPF_REGION_SIZE)
1349                        DMEMIT(" region_size %lu",
1350                               rs->md.bitmap_info.chunksize >> 9);
1351
1352                if (rs->print_flags & DMPF_RAID10_COPIES)
1353                        DMEMIT(" raid10_copies %u",
1354                               raid10_md_layout_to_copies(rs->md.layout));
1355
1356                if (rs->print_flags & DMPF_RAID10_FORMAT)
1357                        DMEMIT(" raid10_format near");
1358
1359                DMEMIT(" %d", rs->md.raid_disks);
1360                for (i = 0; i < rs->md.raid_disks; i++) {
1361                        if (rs->dev[i].meta_dev)
1362                                DMEMIT(" %s", rs->dev[i].meta_dev->name);
1363                        else
1364                                DMEMIT(" -");
1365
1366                        if (rs->dev[i].data_dev)
1367                                DMEMIT(" %s", rs->dev[i].data_dev->name);
1368                        else
1369                                DMEMIT(" -");
1370                }
1371        }
1372
1373        return 0;
1374}
1375
1376static int raid_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data)
1377{
1378        struct raid_set *rs = ti->private;
1379        unsigned i;
1380        int ret = 0;
1381
1382        for (i = 0; !ret && i < rs->md.raid_disks; i++)
1383                if (rs->dev[i].data_dev)
1384                        ret = fn(ti,
1385                                 rs->dev[i].data_dev,
1386                                 0, /* No offset on data devs */
1387                                 rs->md.dev_sectors,
1388                                 data);
1389
1390        return ret;
1391}
1392
1393static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
1394{
1395        struct raid_set *rs = ti->private;
1396        unsigned chunk_size = rs->md.chunk_sectors << 9;
1397        struct r5conf *conf = rs->md.private;
1398
1399        blk_limits_io_min(limits, chunk_size);
1400        blk_limits_io_opt(limits, chunk_size * (conf->raid_disks - conf->max_degraded));
1401}
1402
1403static void raid_presuspend(struct dm_target *ti)
1404{
1405        struct raid_set *rs = ti->private;
1406
1407        md_stop_writes(&rs->md);
1408}
1409
1410static void raid_postsuspend(struct dm_target *ti)
1411{
1412        struct raid_set *rs = ti->private;
1413
1414        mddev_suspend(&rs->md);
1415}
1416
1417static void raid_resume(struct dm_target *ti)
1418{
1419        struct raid_set *rs = ti->private;
1420
1421        set_bit(MD_CHANGE_DEVS, &rs->md.flags);
1422        if (!rs->bitmap_loaded) {
1423                bitmap_load(&rs->md);
1424                rs->bitmap_loaded = 1;
1425        }
1426
1427        clear_bit(MD_RECOVERY_FROZEN, &rs->md.recovery);
1428        mddev_resume(&rs->md);
1429}
1430
1431static struct target_type raid_target = {
1432        .name = "raid",
1433        .version = {1, 3, 1},
1434        .module = THIS_MODULE,
1435        .ctr = raid_ctr,
1436        .dtr = raid_dtr,
1437        .map = raid_map,
1438        .status = raid_status,
1439        .iterate_devices = raid_iterate_devices,
1440        .io_hints = raid_io_hints,
1441        .presuspend = raid_presuspend,
1442        .postsuspend = raid_postsuspend,
1443        .resume = raid_resume,
1444};
1445
1446static int __init dm_raid_init(void)
1447{
1448        return dm_register_target(&raid_target);
1449}
1450
1451static void __exit dm_raid_exit(void)
1452{
1453        dm_unregister_target(&raid_target);
1454}
1455
1456module_init(dm_raid_init);
1457module_exit(dm_raid_exit);
1458
1459MODULE_DESCRIPTION(DM_NAME " raid4/5/6 target");
1460MODULE_ALIAS("dm-raid1");
1461MODULE_ALIAS("dm-raid10");
1462MODULE_ALIAS("dm-raid4");
1463MODULE_ALIAS("dm-raid5");
1464MODULE_ALIAS("dm-raid6");
1465MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>");
1466MODULE_LICENSE("GPL");
1467
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