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