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 char *raid10_md_layout_to_format(int layout)
  95{
  96        /*
  97         * Bit 16 and 17 stand for "offset" and "use_far_sets"
  98         * Refer to MD's raid10.c for details
  99         */
 100        if ((layout & 0x10000) && (layout & 0x20000))
 101                return "offset";
 102
 103        if ((layout & 0xFF) > 1)
 104                return "near";
 105
 106        return "far";
 107}
 108
 109static unsigned raid10_md_layout_to_copies(int layout)
 110{
 111        if ((layout & 0xFF) > 1)
 112                return layout & 0xFF;
 113        return (layout >> 8) & 0xFF;
 114}
 115
 116static int raid10_format_to_md_layout(char *format, unsigned copies)
 117{
 118        unsigned n = 1, f = 1;
 119
 120        if (!strcmp("near", format))
 121                n = copies;
 122        else
 123                f = copies;
 124
 125        if (!strcmp("offset", format))
 126                return 0x30000 | (f << 8) | n;
 127
 128        if (!strcmp("far", format))
 129                return 0x20000 | (f << 8) | n;
 130
 131        return (f << 8) | n;
 132}
 133
 134static struct raid_type *get_raid_type(char *name)
 135{
 136        int i;
 137
 138        for (i = 0; i < ARRAY_SIZE(raid_types); i++)
 139                if (!strcmp(raid_types[i].name, name))
 140                        return &raid_types[i];
 141
 142        return NULL;
 143}
 144
 145static struct raid_set *context_alloc(struct dm_target *ti, struct raid_type *raid_type, unsigned raid_devs)
 146{
 147        unsigned i;
 148        struct raid_set *rs;
 149
 150        if (raid_devs <= raid_type->parity_devs) {
 151                ti->error = "Insufficient number of devices";
 152                return ERR_PTR(-EINVAL);
 153        }
 154
 155        rs = kzalloc(sizeof(*rs) + raid_devs * sizeof(rs->dev[0]), GFP_KERNEL);
 156        if (!rs) {
 157                ti->error = "Cannot allocate raid context";
 158                return ERR_PTR(-ENOMEM);
 159        }
 160
 161        mddev_init(&rs->md);
 162
 163        rs->ti = ti;
 164        rs->raid_type = raid_type;
 165        rs->md.raid_disks = raid_devs;
 166        rs->md.level = raid_type->level;
 167        rs->md.new_level = rs->md.level;
 168        rs->md.layout = raid_type->algorithm;
 169        rs->md.new_layout = rs->md.layout;
 170        rs->md.delta_disks = 0;
 171        rs->md.recovery_cp = 0;
 172
 173        for (i = 0; i < raid_devs; i++)
 174                md_rdev_init(&rs->dev[i].rdev);
 175
 176        /*
 177         * Remaining items to be initialized by further RAID params:
 178         *  rs->md.persistent
 179         *  rs->md.external
 180         *  rs->md.chunk_sectors
 181         *  rs->md.new_chunk_sectors
 182         *  rs->md.dev_sectors
 183         */
 184
 185        return rs;
 186}
 187
 188static void context_free(struct raid_set *rs)
 189{
 190        int i;
 191
 192        for (i = 0; i < rs->md.raid_disks; i++) {
 193                if (rs->dev[i].meta_dev)
 194                        dm_put_device(rs->ti, rs->dev[i].meta_dev);
 195                md_rdev_clear(&rs->dev[i].rdev);
 196                if (rs->dev[i].data_dev)
 197                        dm_put_device(rs->ti, rs->dev[i].data_dev);
 198        }
 199
 200        kfree(rs);
 201}
 202
 203/*
 204 * For every device we have two words
 205 *  <meta_dev>: meta device name or '-' if missing
 206 *  <data_dev>: data device name or '-' if missing
 207 *
 208 * The following are permitted:
 209 *    - -
 210 *    - <data_dev>
 211 *    <meta_dev> <data_dev>
 212 *
 213 * The following is not allowed:
 214 *    <meta_dev> -
 215 *
 216 * This code parses those words.  If there is a failure,
 217 * the caller must use context_free to unwind the operations.
 218 */
 219static int dev_parms(struct raid_set *rs, char **argv)
 220{
 221        int i;
 222        int rebuild = 0;
 223        int metadata_available = 0;
 224        int ret = 0;
 225
 226        for (i = 0; i < rs->md.raid_disks; i++, argv += 2) {
 227                rs->dev[i].rdev.raid_disk = i;
 228
 229                rs->dev[i].meta_dev = NULL;
 230                rs->dev[i].data_dev = NULL;
 231
 232                /*
 233                 * There are no offsets, since there is a separate device
 234                 * for data and metadata.
 235                 */
 236                rs->dev[i].rdev.data_offset = 0;
 237                rs->dev[i].rdev.mddev = &rs->md;
 238
 239                if (strcmp(argv[0], "-")) {
 240                        ret = dm_get_device(rs->ti, argv[0],
 241                                            dm_table_get_mode(rs->ti->table),
 242                                            &rs->dev[i].meta_dev);
 243                        rs->ti->error = "RAID metadata device lookup failure";
 244                        if (ret)
 245                                return ret;
 246
 247                        rs->dev[i].rdev.sb_page = alloc_page(GFP_KERNEL);
 248                        if (!rs->dev[i].rdev.sb_page)
 249                                return -ENOMEM;
 250                }
 251
 252                if (!strcmp(argv[1], "-")) {
 253                        if (!test_bit(In_sync, &rs->dev[i].rdev.flags) &&
 254                            (!rs->dev[i].rdev.recovery_offset)) {
 255                                rs->ti->error = "Drive designated for rebuild not specified";
 256                                return -EINVAL;
 257                        }
 258
 259                        rs->ti->error = "No data device supplied with metadata device";
 260                        if (rs->dev[i].meta_dev)
 261                                return -EINVAL;
 262
 263                        continue;
 264                }
 265
 266                ret = dm_get_device(rs->ti, argv[1],
 267                                    dm_table_get_mode(rs->ti->table),
 268                                    &rs->dev[i].data_dev);
 269                if (ret) {
 270                        rs->ti->error = "RAID device lookup failure";
 271                        return ret;
 272                }
 273
 274                if (rs->dev[i].meta_dev) {
 275                        metadata_available = 1;
 276                        rs->dev[i].rdev.meta_bdev = rs->dev[i].meta_dev->bdev;
 277                }
 278                rs->dev[i].rdev.bdev = rs->dev[i].data_dev->bdev;
 279                list_add(&rs->dev[i].rdev.same_set, &rs->md.disks);
 280                if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
 281                        rebuild++;
 282        }
 283
 284        if (metadata_available) {
 285                rs->md.external = 0;
 286                rs->md.persistent = 1;
 287                rs->md.major_version = 2;
 288        } else if (rebuild && !rs->md.recovery_cp) {
 289                /*
 290                 * Without metadata, we will not be able to tell if the array
 291                 * is in-sync or not - we must assume it is not.  Therefore,
 292                 * it is impossible to rebuild a drive.
 293                 *
 294                 * Even if there is metadata, the on-disk information may
 295                 * indicate that the array is not in-sync and it will then
 296                 * fail at that time.
 297                 *
 298                 * User could specify 'nosync' option if desperate.
 299                 */
 300                DMERR("Unable to rebuild drive while array is not in-sync");
 301                rs->ti->error = "RAID device lookup failure";
 302                return -EINVAL;
 303        }
 304
 305        return 0;
 306}
 307
 308/*
 309 * validate_region_size
 310 * @rs
 311 * @region_size:  region size in sectors.  If 0, pick a size (4MiB default).
 312 *
 313 * Set rs->md.bitmap_info.chunksize (which really refers to 'region size').
 314 * Ensure that (ti->len/region_size < 2^21) - required by MD bitmap.
 315 *
 316 * Returns: 0 on success, -EINVAL on failure.
 317 */
 318static int validate_region_size(struct raid_set *rs, unsigned long region_size)
 319{
 320        unsigned long min_region_size = rs->ti->len / (1 << 21);
 321
 322        if (!region_size) {
 323                /*
 324                 * Choose a reasonable default.  All figures in sectors.
 325                 */
 326                if (min_region_size > (1 << 13)) {
 327                        /* If not a power of 2, make it the next power of 2 */
 328                        if (min_region_size & (min_region_size - 1))
 329                                region_size = 1 << fls(region_size);
 330                        DMINFO("Choosing default region size of %lu sectors",
 331                               region_size);
 332                } else {
 333                        DMINFO("Choosing default region size of 4MiB");
 334                        region_size = 1 << 13; /* sectors */
 335                }
 336        } else {
 337                /*
 338                 * Validate user-supplied value.
 339                 */
 340                if (region_size > rs->ti->len) {
 341                        rs->ti->error = "Supplied region size is too large";
 342                        return -EINVAL;
 343                }
 344
 345                if (region_size < min_region_size) {
 346                        DMERR("Supplied region_size (%lu sectors) below minimum (%lu)",
 347                              region_size, min_region_size);
 348                        rs->ti->error = "Supplied region size is too small";
 349                        return -EINVAL;
 350                }
 351
 352                if (!is_power_of_2(region_size)) {
 353                        rs->ti->error = "Region size is not a power of 2";
 354                        return -EINVAL;
 355                }
 356
 357                if (region_size < rs->md.chunk_sectors) {
 358                        rs->ti->error = "Region size is smaller than the chunk size";
 359                        return -EINVAL;
 360                }
 361        }
 362
 363        /*
 364         * Convert sectors to bytes.
 365         */
 366        rs->md.bitmap_info.chunksize = (region_size << 9);
 367
 368        return 0;
 369}
 370
 371/*
 372 * validate_raid_redundancy
 373 * @rs
 374 *
 375 * Determine if there are enough devices in the array that haven't
 376 * failed (or are being rebuilt) to form a usable array.
 377 *
 378 * Returns: 0 on success, -EINVAL on failure.
 379 */
 380static int validate_raid_redundancy(struct raid_set *rs)
 381{
 382        unsigned i, rebuild_cnt = 0;
 383        unsigned rebuilds_per_group, copies, d;
 384        unsigned group_size, last_group_start;
 385
 386        for (i = 0; i < rs->md.raid_disks; i++)
 387                if (!test_bit(In_sync, &rs->dev[i].rdev.flags) ||
 388                    !rs->dev[i].rdev.sb_page)
 389                        rebuild_cnt++;
 390
 391        switch (rs->raid_type->level) {
 392        case 1:
 393                if (rebuild_cnt >= rs->md.raid_disks)
 394                        goto too_many;
 395                break;
 396        case 4:
 397        case 5:
 398        case 6:
 399                if (rebuild_cnt > rs->raid_type->parity_devs)
 400                        goto too_many;
 401                break;
 402        case 10:
 403                copies = raid10_md_layout_to_copies(rs->md.layout);
 404                if (rebuild_cnt < copies)
 405                        break;
 406
 407                /*
 408                 * It is possible to have a higher rebuild count for RAID10,
 409                 * as long as the failed devices occur in different mirror
 410                 * groups (i.e. different stripes).
 411                 *
 412                 * When checking "near" format, make sure no adjacent devices
 413                 * have failed beyond what can be handled.  In addition to the
 414                 * simple case where the number of devices is a multiple of the
 415                 * number of copies, we must also handle cases where the number
 416                 * of devices is not a multiple of the number of copies.
 417                 * E.g.    dev1 dev2 dev3 dev4 dev5
 418                 *          A    A    B    B    C
 419                 *          C    D    D    E    E
 420                 */
 421                if (!strcmp("near", raid10_md_layout_to_format(rs->md.layout))) {
 422                        for (i = 0; i < rs->md.raid_disks * copies; i++) {
 423                                if (!(i % copies))
 424                                        rebuilds_per_group = 0;
 425                                d = i % rs->md.raid_disks;
 426                                if ((!rs->dev[d].rdev.sb_page ||
 427                                     !test_bit(In_sync, &rs->dev[d].rdev.flags)) &&
 428                                    (++rebuilds_per_group >= copies))
 429                                        goto too_many;
 430                        }
 431                        break;
 432                }
 433
 434                /*
 435                 * When checking "far" and "offset" formats, we need to ensure
 436                 * that the device that holds its copy is not also dead or
 437                 * being rebuilt.  (Note that "far" and "offset" formats only
 438                 * support two copies right now.  These formats also only ever
 439                 * use the 'use_far_sets' variant.)
 440                 *
 441                 * This check is somewhat complicated by the need to account
 442                 * for arrays that are not a multiple of (far) copies.  This
 443                 * results in the need to treat the last (potentially larger)
 444                 * set differently.
 445                 */
 446                group_size = (rs->md.raid_disks / copies);
 447                last_group_start = (rs->md.raid_disks / group_size) - 1;
 448                last_group_start *= group_size;
 449                for (i = 0; i < rs->md.raid_disks; i++) {
 450                        if (!(i % copies) && !(i > last_group_start))
 451                                rebuilds_per_group = 0;
 452                        if ((!rs->dev[i].rdev.sb_page ||
 453                             !test_bit(In_sync, &rs->dev[i].rdev.flags)) &&
 454                            (++rebuilds_per_group >= copies))
 455                                        goto too_many;
 456                }
 457                break;
 458        default:
 459                if (rebuild_cnt)
 460                        return -EINVAL;
 461        }
 462
 463        return 0;
 464
 465too_many:
 466        return -EINVAL;
 467}
 468
 469/*
 470 * Possible arguments are...
 471 *      <chunk_size> [optional_args]
 472 *
 473 * Argument definitions
 474 *    <chunk_size>                      The number of sectors per disk that
 475 *                                      will form the "stripe"
 476 *    [[no]sync]                        Force or prevent recovery of the
 477 *                                      entire array
 478 *    [rebuild <idx>]                   Rebuild the drive indicated by the index
 479 *    [daemon_sleep <ms>]               Time between bitmap daemon work to
 480 *                                      clear bits
 481 *    [min_recovery_rate <kB/sec/disk>] Throttle RAID initialization
 482 *    [max_recovery_rate <kB/sec/disk>] Throttle RAID initialization
 483 *    [write_mostly <idx>]              Indicate a write mostly drive via index
 484 *    [max_write_behind <sectors>]      See '-write-behind=' (man mdadm)
 485 *    [stripe_cache <sectors>]          Stripe cache size for higher RAIDs
 486 *    [region_size <sectors>]           Defines granularity of bitmap
 487 *
 488 * RAID10-only options:
 489 *    [raid10_copies <# copies>]        Number of copies.  (Default: 2)
 490 *    [raid10_format <near|far|offset>] Layout algorithm.  (Default: near)
 491 */
 492static int parse_raid_params(struct raid_set *rs, char **argv,
 493                             unsigned num_raid_params)
 494{
 495        char *raid10_format = "near";
 496        unsigned raid10_copies = 2;
 497        unsigned i;
 498        unsigned long value, region_size = 0;
 499        sector_t sectors_per_dev = rs->ti->len;
 500        sector_t max_io_len;
 501        char *key;
 502
 503        /*
 504         * First, parse the in-order required arguments
 505         * "chunk_size" is the only argument of this type.
 506         */
 507        if ((strict_strtoul(argv[0], 10, &value) < 0)) {
 508                rs->ti->error = "Bad chunk size";
 509                return -EINVAL;
 510        } else if (rs->raid_type->level == 1) {
 511                if (value)
 512                        DMERR("Ignoring chunk size parameter for RAID 1");
 513                value = 0;
 514        } else if (!is_power_of_2(value)) {
 515                rs->ti->error = "Chunk size must be a power of 2";
 516                return -EINVAL;
 517        } else if (value < 8) {
 518                rs->ti->error = "Chunk size value is too small";
 519                return -EINVAL;
 520        }
 521
 522        rs->md.new_chunk_sectors = rs->md.chunk_sectors = value;
 523        argv++;
 524        num_raid_params--;
 525
 526        /*
 527         * We set each individual device as In_sync with a completed
 528         * 'recovery_offset'.  If there has been a device failure or
 529         * replacement then one of the following cases applies:
 530         *
 531         *   1) User specifies 'rebuild'.
 532         *      - Device is reset when param is read.
 533         *   2) A new device is supplied.
 534         *      - No matching superblock found, resets device.
 535         *   3) Device failure was transient and returns on reload.
 536         *      - Failure noticed, resets device for bitmap replay.
 537         *   4) Device hadn't completed recovery after previous failure.
 538         *      - Superblock is read and overrides recovery_offset.
 539         *
 540         * What is found in the superblocks of the devices is always
 541         * authoritative, unless 'rebuild' or '[no]sync' was specified.
 542         */
 543        for (i = 0; i < rs->md.raid_disks; i++) {
 544                set_bit(In_sync, &rs->dev[i].rdev.flags);
 545                rs->dev[i].rdev.recovery_offset = MaxSector;
 546        }
 547
 548        /*
 549         * Second, parse the unordered optional arguments
 550         */
 551        for (i = 0; i < num_raid_params; i++) {
 552                if (!strcasecmp(argv[i], "nosync")) {
 553                        rs->md.recovery_cp = MaxSector;
 554                        rs->print_flags |= DMPF_NOSYNC;
 555                        continue;
 556                }
 557                if (!strcasecmp(argv[i], "sync")) {
 558                        rs->md.recovery_cp = 0;
 559                        rs->print_flags |= DMPF_SYNC;
 560                        continue;
 561                }
 562
 563                /* The rest of the optional arguments come in key/value pairs */
 564                if ((i + 1) >= num_raid_params) {
 565                        rs->ti->error = "Wrong number of raid parameters given";
 566                        return -EINVAL;
 567                }
 568
 569                key = argv[i++];
 570
 571                /* Parameters that take a string value are checked here. */
 572                if (!strcasecmp(key, "raid10_format")) {
 573                        if (rs->raid_type->level != 10) {
 574                                rs->ti->error = "'raid10_format' is an invalid parameter for this RAID type";
 575                                return -EINVAL;
 576                        }
 577                        if (strcmp("near", argv[i]) &&
 578                            strcmp("far", argv[i]) &&
 579                            strcmp("offset", argv[i])) {
 580                                rs->ti->error = "Invalid 'raid10_format' value given";
 581                                return -EINVAL;
 582                        }
 583                        raid10_format = argv[i];
 584                        rs->print_flags |= DMPF_RAID10_FORMAT;
 585                        continue;
 586                }
 587
 588                if (strict_strtoul(argv[i], 10, &value) < 0) {
 589                        rs->ti->error = "Bad numerical argument given in raid params";
 590                        return -EINVAL;
 591                }
 592
 593                /* Parameters that take a numeric value are checked here */
 594                if (!strcasecmp(key, "rebuild")) {
 595                        if (value >= rs->md.raid_disks) {
 596                                rs->ti->error = "Invalid rebuild index given";
 597                                return -EINVAL;
 598                        }
 599                        clear_bit(In_sync, &rs->dev[value].rdev.flags);
 600                        rs->dev[value].rdev.recovery_offset = 0;
 601                        rs->print_flags |= DMPF_REBUILD;
 602                } else if (!strcasecmp(key, "write_mostly")) {
 603                        if (rs->raid_type->level != 1) {
 604                                rs->ti->error = "write_mostly option is only valid for RAID1";
 605                                return -EINVAL;
 606                        }
 607                        if (value >= rs->md.raid_disks) {
 608                                rs->ti->error = "Invalid write_mostly drive index given";
 609                                return -EINVAL;
 610                        }
 611                        set_bit(WriteMostly, &rs->dev[value].rdev.flags);
 612                } else if (!strcasecmp(key, "max_write_behind")) {
 613                        if (rs->raid_type->level != 1) {
 614                                rs->ti->error = "max_write_behind option is only valid for RAID1";
 615                                return -EINVAL;
 616                        }
 617                        rs->print_flags |= DMPF_MAX_WRITE_BEHIND;
 618
 619                        /*
 620                         * In device-mapper, we specify things in sectors, but
 621                         * MD records this value in kB
 622                         */
 623                        value /= 2;
 624                        if (value > COUNTER_MAX) {
 625                                rs->ti->error = "Max write-behind limit out of range";
 626                                return -EINVAL;
 627                        }
 628                        rs->md.bitmap_info.max_write_behind = value;
 629                } else if (!strcasecmp(key, "daemon_sleep")) {
 630                        rs->print_flags |= DMPF_DAEMON_SLEEP;
 631                        if (!value || (value > MAX_SCHEDULE_TIMEOUT)) {
 632                                rs->ti->error = "daemon sleep period out of range";
 633                                return -EINVAL;
 634                        }
 635                        rs->md.bitmap_info.daemon_sleep = value;
 636                } else if (!strcasecmp(key, "stripe_cache")) {
 637                        rs->print_flags |= DMPF_STRIPE_CACHE;
 638
 639                        /*
 640                         * In device-mapper, we specify things in sectors, but
 641                         * MD records this value in kB
 642                         */
 643                        value /= 2;
 644
 645                        if ((rs->raid_type->level != 5) &&
 646                            (rs->raid_type->level != 6)) {
 647                                rs->ti->error = "Inappropriate argument: stripe_cache";
 648                                return -EINVAL;
 649                        }
 650                        if (raid5_set_cache_size(&rs->md, (int)value)) {
 651                                rs->ti->error = "Bad stripe_cache size";
 652                                return -EINVAL;
 653                        }
 654                } else if (!strcasecmp(key, "min_recovery_rate")) {
 655                        rs->print_flags |= DMPF_MIN_RECOVERY_RATE;
 656                        if (value > INT_MAX) {
 657                                rs->ti->error = "min_recovery_rate out of range";
 658                                return -EINVAL;
 659                        }
 660                        rs->md.sync_speed_min = (int)value;
 661                } else if (!strcasecmp(key, "max_recovery_rate")) {
 662                        rs->print_flags |= DMPF_MAX_RECOVERY_RATE;
 663                        if (value > INT_MAX) {
 664                                rs->ti->error = "max_recovery_rate out of range";
 665                                return -EINVAL;
 666                        }
 667                        rs->md.sync_speed_max = (int)value;
 668                } else if (!strcasecmp(key, "region_size")) {
 669                        rs->print_flags |= DMPF_REGION_SIZE;
 670                        region_size = value;
 671                } else if (!strcasecmp(key, "raid10_copies") &&
 672                           (rs->raid_type->level == 10)) {
 673                        if ((value < 2) || (value > 0xFF)) {
 674                                rs->ti->error = "Bad value for 'raid10_copies'";
 675                                return -EINVAL;
 676                        }
 677                        rs->print_flags |= DMPF_RAID10_COPIES;
 678                        raid10_copies = value;
 679                } else {
 680                        DMERR("Unable to parse RAID parameter: %s", key);
 681                        rs->ti->error = "Unable to parse RAID parameters";
 682                        return -EINVAL;
 683                }
 684        }
 685
 686        if (validate_region_size(rs, region_size))
 687                return -EINVAL;
 688
 689        if (rs->md.chunk_sectors)
 690                max_io_len = rs->md.chunk_sectors;
 691        else
 692                max_io_len = region_size;
 693
 694        if (dm_set_target_max_io_len(rs->ti, max_io_len))
 695                return -EINVAL;
 696
 697        if (rs->raid_type->level == 10) {
 698                if (raid10_copies > rs->md.raid_disks) {
 699                        rs->ti->error = "Not enough devices to satisfy specification";
 700                        return -EINVAL;
 701                }
 702
 703                /*
 704                 * If the format is not "near", we only support
 705                 * two copies at the moment.
 706                 */
 707                if (strcmp("near", raid10_format) && (raid10_copies > 2)) {
 708                        rs->ti->error = "Too many copies for given RAID10 format.";
 709                        return -EINVAL;
 710                }
 711
 712                /* (Len * #mirrors) / #devices */
 713                sectors_per_dev = rs->ti->len * raid10_copies;
 714                sector_div(sectors_per_dev, rs->md.raid_disks);
 715
 716                rs->md.layout = raid10_format_to_md_layout(raid10_format,
 717                                                           raid10_copies);
 718                rs->md.new_layout = rs->md.layout;
 719        } else if ((rs->raid_type->level > 1) &&
 720                   sector_div(sectors_per_dev,
 721                              (rs->md.raid_disks - rs->raid_type->parity_devs))) {
 722                rs->ti->error = "Target length not divisible by number of data devices";
 723                return -EINVAL;
 724        }
 725        rs->md.dev_sectors = sectors_per_dev;
 726
 727        /* Assume there are no metadata devices until the drives are parsed */
 728        rs->md.persistent = 0;
 729        rs->md.external = 1;
 730
 731        return 0;
 732}
 733
 734static void do_table_event(struct work_struct *ws)
 735{
 736        struct raid_set *rs = container_of(ws, struct raid_set, md.event_work);
 737
 738        dm_table_event(rs->ti->table);
 739}
 740
 741static int raid_is_congested(struct dm_target_callbacks *cb, int bits)
 742{
 743        struct raid_set *rs = container_of(cb, struct raid_set, callbacks);
 744
 745        if (rs->raid_type->level == 1)
 746                return md_raid1_congested(&rs->md, bits);
 747
 748        if (rs->raid_type->level == 10)
 749                return md_raid10_congested(&rs->md, bits);
 750
 751        return md_raid5_congested(&rs->md, bits);
 752}
 753
 754/*
 755 * This structure is never routinely used by userspace, unlike md superblocks.
 756 * Devices with this superblock should only ever be accessed via device-mapper.
 757 */
 758#define DM_RAID_MAGIC 0x64526D44
 759struct dm_raid_superblock {
 760        __le32 magic;           /* "DmRd" */
 761        __le32 features;        /* Used to indicate possible future changes */
 762
 763        __le32 num_devices;     /* Number of devices in this array. (Max 64) */
 764        __le32 array_position;  /* The position of this drive in the array */
 765
 766        __le64 events;          /* Incremented by md when superblock updated */
 767        __le64 failed_devices;  /* Bit field of devices to indicate failures */
 768
 769        /*
 770         * This offset tracks the progress of the repair or replacement of
 771         * an individual drive.
 772         */
 773        __le64 disk_recovery_offset;
 774
 775        /*
 776         * This offset tracks the progress of the initial array
 777         * synchronisation/parity calculation.
 778         */
 779        __le64 array_resync_offset;
 780
 781        /*
 782         * RAID characteristics
 783         */
 784        __le32 level;
 785        __le32 layout;
 786        __le32 stripe_sectors;
 787
 788        __u8 pad[452];          /* Round struct to 512 bytes. */
 789                                /* Always set to 0 when writing. */
 790} __packed;
 791
 792static int read_disk_sb(struct md_rdev *rdev, int size)
 793{
 794        BUG_ON(!rdev->sb_page);
 795
 796        if (rdev->sb_loaded)
 797                return 0;
 798
 799        if (!sync_page_io(rdev, 0, size, rdev->sb_page, READ, 1)) {
 800                DMERR("Failed to read superblock of device at position %d",
 801                      rdev->raid_disk);
 802                md_error(rdev->mddev, rdev);
 803                return -EINVAL;
 804        }
 805
 806        rdev->sb_loaded = 1;
 807
 808        return 0;
 809}
 810
 811static void super_sync(struct mddev *mddev, struct md_rdev *rdev)
 812{
 813        int i;
 814        uint64_t failed_devices;
 815        struct dm_raid_superblock *sb;
 816        struct raid_set *rs = container_of(mddev, struct raid_set, md);
 817
 818        sb = page_address(rdev->sb_page);
 819        failed_devices = le64_to_cpu(sb->failed_devices);
 820
 821        for (i = 0; i < mddev->raid_disks; i++)
 822                if (!rs->dev[i].data_dev ||
 823                    test_bit(Faulty, &(rs->dev[i].rdev.flags)))
 824                        failed_devices |= (1ULL << i);
 825
 826        memset(sb, 0, sizeof(*sb));
 827
 828        sb->magic = cpu_to_le32(DM_RAID_MAGIC);
 829        sb->features = cpu_to_le32(0);  /* No features yet */
 830
 831        sb->num_devices = cpu_to_le32(mddev->raid_disks);
 832        sb->array_position = cpu_to_le32(rdev->raid_disk);
 833
 834        sb->events = cpu_to_le64(mddev->events);
 835        sb->failed_devices = cpu_to_le64(failed_devices);
 836
 837        sb->disk_recovery_offset = cpu_to_le64(rdev->recovery_offset);
 838        sb->array_resync_offset = cpu_to_le64(mddev->recovery_cp);
 839
 840        sb->level = cpu_to_le32(mddev->level);
 841        sb->layout = cpu_to_le32(mddev->layout);
 842        sb->stripe_sectors = cpu_to_le32(mddev->chunk_sectors);
 843}
 844
 845/*
 846 * super_load
 847 *
 848 * This function creates a superblock if one is not found on the device
 849 * and will decide which superblock to use if there's a choice.
 850 *
 851 * Return: 1 if use rdev, 0 if use refdev, -Exxx otherwise
 852 */
 853static int super_load(struct md_rdev *rdev, struct md_rdev *refdev)
 854{
 855        int ret;
 856        struct dm_raid_superblock *sb;
 857        struct dm_raid_superblock *refsb;
 858        uint64_t events_sb, events_refsb;
 859
 860        rdev->sb_start = 0;
 861        rdev->sb_size = sizeof(*sb);
 862
 863        ret = read_disk_sb(rdev, rdev->sb_size);
 864        if (ret)
 865                return ret;
 866
 867        sb = page_address(rdev->sb_page);
 868
 869        /*
 870         * Two cases that we want to write new superblocks and rebuild:
 871         * 1) New device (no matching magic number)
 872         * 2) Device specified for rebuild (!In_sync w/ offset == 0)
 873         */
 874        if ((sb->magic != cpu_to_le32(DM_RAID_MAGIC)) ||
 875            (!test_bit(In_sync, &rdev->flags) && !rdev->recovery_offset)) {
 876                super_sync(rdev->mddev, rdev);
 877
 878                set_bit(FirstUse, &rdev->flags);
 879
 880                /* Force writing of superblocks to disk */
 881                set_bit(MD_CHANGE_DEVS, &rdev->mddev->flags);
 882
 883                /* Any superblock is better than none, choose that if given */
 884                return refdev ? 0 : 1;
 885        }
 886
 887        if (!refdev)
 888                return 1;
 889
 890        events_sb = le64_to_cpu(sb->events);
 891
 892        refsb = page_address(refdev->sb_page);
 893        events_refsb = le64_to_cpu(refsb->events);
 894
 895        return (events_sb > events_refsb) ? 1 : 0;
 896}
 897
 898static int super_init_validation(struct mddev *mddev, struct md_rdev *rdev)
 899{
 900        int role;
 901        struct raid_set *rs = container_of(mddev, struct raid_set, md);
 902        uint64_t events_sb;
 903        uint64_t failed_devices;
 904        struct dm_raid_superblock *sb;
 905        uint32_t new_devs = 0;
 906        uint32_t rebuilds = 0;
 907        struct md_rdev *r;
 908        struct dm_raid_superblock *sb2;
 909
 910        sb = page_address(rdev->sb_page);
 911        events_sb = le64_to_cpu(sb->events);
 912        failed_devices = le64_to_cpu(sb->failed_devices);
 913
 914        /*
 915         * Initialise to 1 if this is a new superblock.
 916         */
 917        mddev->events = events_sb ? : 1;
 918
 919        /*
 920         * Reshaping is not currently allowed
 921         */
 922        if (le32_to_cpu(sb->level) != mddev->level) {
 923                DMERR("Reshaping arrays not yet supported. (RAID level change)");
 924                return -EINVAL;
 925        }
 926        if (le32_to_cpu(sb->layout) != mddev->layout) {
 927                DMERR("Reshaping arrays not yet supported. (RAID layout change)");
 928                DMERR("  0x%X vs 0x%X", le32_to_cpu(sb->layout), mddev->layout);
 929                DMERR("  Old layout: %s w/ %d copies",
 930                      raid10_md_layout_to_format(le32_to_cpu(sb->layout)),
 931                      raid10_md_layout_to_copies(le32_to_cpu(sb->layout)));
 932                DMERR("  New layout: %s w/ %d copies",
 933                      raid10_md_layout_to_format(mddev->layout),
 934                      raid10_md_layout_to_copies(mddev->layout));
 935                return -EINVAL;
 936        }
 937        if (le32_to_cpu(sb->stripe_sectors) != mddev->chunk_sectors) {
 938                DMERR("Reshaping arrays not yet supported. (stripe sectors change)");
 939                return -EINVAL;
 940        }
 941
 942        /* We can only change the number of devices in RAID1 right now */
 943        if ((rs->raid_type->level != 1) &&
 944            (le32_to_cpu(sb->num_devices) != mddev->raid_disks)) {
 945                DMERR("Reshaping arrays not yet supported. (device count change)");
 946                return -EINVAL;
 947        }
 948
 949        if (!(rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC)))
 950                mddev->recovery_cp = le64_to_cpu(sb->array_resync_offset);
 951
 952        /*
 953         * During load, we set FirstUse if a new superblock was written.
 954         * There are two reasons we might not have a superblock:
 955         * 1) The array is brand new - in which case, all of the
 956         *    devices must have their In_sync bit set.  Also,
 957         *    recovery_cp must be 0, unless forced.
 958         * 2) This is a new device being added to an old array
 959         *    and the new device needs to be rebuilt - in which
 960         *    case the In_sync bit will /not/ be set and
 961         *    recovery_cp must be MaxSector.
 962         */
 963        rdev_for_each(r, mddev) {
 964                if (!test_bit(In_sync, &r->flags)) {
 965                        DMINFO("Device %d specified for rebuild: "
 966                               "Clearing superblock", r->raid_disk);
 967                        rebuilds++;
 968                } else if (test_bit(FirstUse, &r->flags))
 969                        new_devs++;
 970        }
 971
 972        if (!rebuilds) {
 973                if (new_devs == mddev->raid_disks) {
 974                        DMINFO("Superblocks created for new array");
 975                        set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
 976                } else if (new_devs) {
 977                        DMERR("New device injected "
 978                              "into existing array without 'rebuild' "
 979                              "parameter specified");
 980                        return -EINVAL;
 981                }
 982        } else if (new_devs) {
 983                DMERR("'rebuild' devices cannot be "
 984                      "injected into an array with other first-time devices");
 985                return -EINVAL;
 986        } else if (mddev->recovery_cp != MaxSector) {
 987                DMERR("'rebuild' specified while array is not in-sync");
 988                return -EINVAL;
 989        }
 990
 991        /*
 992         * Now we set the Faulty bit for those devices that are
 993         * recorded in the superblock as failed.
 994         */
 995        rdev_for_each(r, mddev) {
 996                if (!r->sb_page)
 997                        continue;
 998                sb2 = page_address(r->sb_page);
 999                sb2->failed_devices = 0;
1000
1001                /*
1002                 * Check for any device re-ordering.
1003                 */
1004                if (!test_bit(FirstUse, &r->flags) && (r->raid_disk >= 0)) {
1005                        role = le32_to_cpu(sb2->array_position);
1006                        if (role != r->raid_disk) {
1007                                if (rs->raid_type->level != 1) {
1008                                        rs->ti->error = "Cannot change device "
1009                                                "positions in RAID array";
1010                                        return -EINVAL;
1011                                }
1012                                DMINFO("RAID1 device #%d now at position #%d",
1013                                       role, r->raid_disk);
1014                        }
1015
1016                        /*
1017                         * Partial recovery is performed on
1018                         * returning failed devices.
1019                         */
1020                        if (failed_devices & (1 << role))
1021                                set_bit(Faulty, &r->flags);
1022                }
1023        }
1024
1025        return 0;
1026}
1027
1028static int super_validate(struct mddev *mddev, struct md_rdev *rdev)
1029{
1030        struct dm_raid_superblock *sb = page_address(rdev->sb_page);
1031
1032        /*
1033         * If mddev->events is not set, we know we have not yet initialized
1034         * the array.
1035         */
1036        if (!mddev->events && super_init_validation(mddev, rdev))
1037                return -EINVAL;
1038
1039        mddev->bitmap_info.offset = 4096 >> 9; /* Enable bitmap creation */
1040        rdev->mddev->bitmap_info.default_offset = 4096 >> 9;
1041        if (!test_bit(FirstUse, &rdev->flags)) {
1042                rdev->recovery_offset = le64_to_cpu(sb->disk_recovery_offset);
1043                if (rdev->recovery_offset != MaxSector)
1044                        clear_bit(In_sync, &rdev->flags);
1045        }
1046
1047        /*
1048         * If a device comes back, set it as not In_sync and no longer faulty.
1049         */
1050        if (test_bit(Faulty, &rdev->flags)) {
1051                clear_bit(Faulty, &rdev->flags);
1052                clear_bit(In_sync, &rdev->flags);
1053                rdev->saved_raid_disk = rdev->raid_disk;
1054                rdev->recovery_offset = 0;
1055        }
1056
1057        clear_bit(FirstUse, &rdev->flags);
1058
1059        return 0;
1060}
1061
1062/*
1063 * Analyse superblocks and select the freshest.
1064 */
1065static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
1066{
1067        int ret;
1068        struct raid_dev *dev;
1069        struct md_rdev *rdev, *tmp, *freshest;
1070        struct mddev *mddev = &rs->md;
1071
1072        freshest = NULL;
1073        rdev_for_each_safe(rdev, tmp, mddev) {
1074                /*
1075                 * Skipping super_load due to DMPF_SYNC will cause
1076                 * the array to undergo initialization again as
1077                 * though it were new.  This is the intended effect
1078                 * of the "sync" directive.
1079                 *
1080                 * When reshaping capability is added, we must ensure
1081                 * that the "sync" directive is disallowed during the
1082                 * reshape.
1083                 */
1084                if (rs->print_flags & DMPF_SYNC)
1085                        continue;
1086
1087                if (!rdev->meta_bdev)
1088                        continue;
1089
1090                ret = super_load(rdev, freshest);
1091
1092                switch (ret) {
1093                case 1:
1094                        freshest = rdev;
1095                        break;
1096                case 0:
1097                        break;
1098                default:
1099                        dev = container_of(rdev, struct raid_dev, rdev);
1100                        if (dev->meta_dev)
1101                                dm_put_device(ti, dev->meta_dev);
1102
1103                        dev->meta_dev = NULL;
1104                        rdev->meta_bdev = NULL;
1105
1106                        if (rdev->sb_page)
1107                                put_page(rdev->sb_page);
1108
1109                        rdev->sb_page = NULL;
1110
1111                        rdev->sb_loaded = 0;
1112
1113                        /*
1114                         * We might be able to salvage the data device
1115                         * even though the meta device has failed.  For
1116                         * now, we behave as though '- -' had been
1117                         * set for this device in the table.
1118                         */
1119                        if (dev->data_dev)
1120                                dm_put_device(ti, dev->data_dev);
1121
1122                        dev->data_dev = NULL;
1123                        rdev->bdev = NULL;
1124
1125                        list_del(&rdev->same_set);
1126                }
1127        }
1128
1129        if (!freshest)
1130                return 0;
1131
1132        if (validate_raid_redundancy(rs)) {
1133                rs->ti->error = "Insufficient redundancy to activate array";
1134                return -EINVAL;
1135        }
1136
1137        /*
1138         * Validation of the freshest device provides the source of
1139         * validation for the remaining devices.
1140         */
1141        ti->error = "Unable to assemble array: Invalid superblocks";
1142        if (super_validate(mddev, freshest))
1143                return -EINVAL;
1144
1145        rdev_for_each(rdev, mddev)
1146                if ((rdev != freshest) && super_validate(mddev, rdev))
1147                        return -EINVAL;
1148
1149        return 0;
1150}
1151
1152/*
1153 * Construct a RAID4/5/6 mapping:
1154 * Args:
1155 *      <raid_type> <#raid_params> <raid_params>                \
1156 *      <#raid_devs> { <meta_dev1> <dev1> .. <meta_devN> <devN> }
1157 *
1158 * <raid_params> varies by <raid_type>.  See 'parse_raid_params' for
1159 * details on possible <raid_params>.
1160 */
1161static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
1162{
1163        int ret;
1164        struct raid_type *rt;
1165        unsigned long num_raid_params, num_raid_devs;
1166        struct raid_set *rs = NULL;
1167
1168        /* Must have at least <raid_type> <#raid_params> */
1169        if (argc < 2) {
1170                ti->error = "Too few arguments";
1171                return -EINVAL;
1172        }
1173
1174        /* raid type */
1175        rt = get_raid_type(argv[0]);
1176        if (!rt) {
1177                ti->error = "Unrecognised raid_type";
1178                return -EINVAL;
1179        }
1180        argc--;
1181        argv++;
1182
1183        /* number of RAID parameters */
1184        if (strict_strtoul(argv[0], 10, &num_raid_params) < 0) {
1185                ti->error = "Cannot understand number of RAID parameters";
1186                return -EINVAL;
1187        }
1188        argc--;
1189        argv++;
1190
1191        /* Skip over RAID params for now and find out # of devices */
1192        if (num_raid_params + 1 > argc) {
1193                ti->error = "Arguments do not agree with counts given";
1194                return -EINVAL;
1195        }
1196
1197        if ((strict_strtoul(argv[num_raid_params], 10, &num_raid_devs) < 0) ||
1198            (num_raid_devs >= INT_MAX)) {
1199                ti->error = "Cannot understand number of raid devices";
1200                return -EINVAL;
1201        }
1202
1203        rs = context_alloc(ti, rt, (unsigned)num_raid_devs);
1204        if (IS_ERR(rs))
1205                return PTR_ERR(rs);
1206
1207        ret = parse_raid_params(rs, argv, (unsigned)num_raid_params);
1208        if (ret)
1209                goto bad;
1210
1211        ret = -EINVAL;
1212
1213        argc -= num_raid_params + 1; /* +1: we already have num_raid_devs */
1214        argv += num_raid_params + 1;
1215
1216        if (argc != (num_raid_devs * 2)) {
1217                ti->error = "Supplied RAID devices does not match the count given";
1218                goto bad;
1219        }
1220
1221        ret = dev_parms(rs, argv);
1222        if (ret)
1223                goto bad;
1224
1225        rs->md.sync_super = super_sync;
1226        ret = analyse_superblocks(ti, rs);
1227        if (ret)
1228                goto bad;
1229
1230        INIT_WORK(&rs->md.event_work, do_table_event);
1231        ti->private = rs;
1232        ti->num_flush_bios = 1;
1233
1234        mutex_lock(&rs->md.reconfig_mutex);
1235        ret = md_run(&rs->md);
1236        rs->md.in_sync = 0; /* Assume already marked dirty */
1237        mutex_unlock(&rs->md.reconfig_mutex);
1238
1239        if (ret) {
1240                ti->error = "Fail to run raid array";
1241                goto bad;
1242        }
1243
1244        if (ti->len != rs->md.array_sectors) {
1245                ti->error = "Array size does not match requested target length";
1246                ret = -EINVAL;
1247                goto size_mismatch;
1248        }
1249        rs->callbacks.congested_fn = raid_is_congested;
1250        dm_table_add_target_callbacks(ti->table, &rs->callbacks);
1251
1252        mddev_suspend(&rs->md);
1253        return 0;
1254
1255size_mismatch:
1256        md_stop(&rs->md);
1257bad:
1258        context_free(rs);
1259
1260        return ret;
1261}
1262
1263static void raid_dtr(struct dm_target *ti)
1264{
1265        struct raid_set *rs = ti->private;
1266
1267        list_del_init(&rs->callbacks.list);
1268        md_stop(&rs->md);
1269        context_free(rs);
1270}
1271
1272static int raid_map(struct dm_target *ti, struct bio *bio)
1273{
1274        struct raid_set *rs = ti->private;
1275        struct mddev *mddev = &rs->md;
1276
1277        mddev->pers->make_request(mddev, bio);
1278
1279        return DM_MAPIO_SUBMITTED;
1280}
1281
1282static const char *decipher_sync_action(struct mddev *mddev)
1283{
1284        if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
1285                return "frozen";
1286
1287        if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
1288            (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))) {
1289                if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
1290                        return "reshape";
1291
1292                if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
1293                        if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
1294                                return "resync";
1295                        else if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
1296                                return "check";
1297                        return "repair";
1298                }
1299
1300                if (test_bit(MD_RECOVERY_RECOVER, &mddev->recovery))
1301                        return "recover";
1302        }
1303
1304        return "idle";
1305}
1306
1307static void raid_status(struct dm_target *ti, status_type_t type,
1308                        unsigned status_flags, char *result, unsigned maxlen)
1309{
1310        struct raid_set *rs = ti->private;
1311        unsigned raid_param_cnt = 1; /* at least 1 for chunksize */
1312        unsigned sz = 0;
1313        int i, array_in_sync = 0;
1314        sector_t sync;
1315
1316        switch (type) {
1317        case STATUSTYPE_INFO:
1318                DMEMIT("%s %d ", rs->raid_type->name, rs->md.raid_disks);
1319
1320                if (test_bit(MD_RECOVERY_RUNNING, &rs->md.recovery))
1321                        sync = rs->md.curr_resync_completed;
1322                else
1323                        sync = rs->md.recovery_cp;
1324
1325                if (sync >= rs->md.resync_max_sectors) {
1326                        /*
1327                         * Sync complete.
1328                         */
1329                        array_in_sync = 1;
1330                        sync = rs->md.resync_max_sectors;
1331                } else if (test_bit(MD_RECOVERY_REQUESTED, &rs->md.recovery)) {
1332                        /*
1333                         * If "check" or "repair" is occurring, the array has
1334                         * undergone and initial sync and the health characters
1335                         * should not be 'a' anymore.
1336                         */
1337                        array_in_sync = 1;
1338                } else {
1339                        /*
1340                         * The array may be doing an initial sync, or it may
1341                         * be rebuilding individual components.  If all the
1342                         * devices are In_sync, then it is the array that is
1343                         * being initialized.
1344                         */
1345                        for (i = 0; i < rs->md.raid_disks; i++)
1346                                if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
1347                                        array_in_sync = 1;
1348                }
1349
1350                /*
1351                 * Status characters:
1352                 *  'D' = Dead/Failed device
1353                 *  'a' = Alive but not in-sync
1354                 *  'A' = Alive and in-sync
1355                 */
1356                for (i = 0; i < rs->md.raid_disks; i++) {
1357                        if (test_bit(Faulty, &rs->dev[i].rdev.flags))
1358                                DMEMIT("D");
1359                        else if (!array_in_sync ||
1360                                 !test_bit(In_sync, &rs->dev[i].rdev.flags))
1361                                DMEMIT("a");
1362                        else
1363                                DMEMIT("A");
1364                }
1365
1366                /*
1367                 * In-sync ratio:
1368                 *  The in-sync ratio shows the progress of:
1369                 *   - Initializing the array
1370                 *   - Rebuilding a subset of devices of the array
1371                 *  The user can distinguish between the two by referring
1372                 *  to the status characters.
1373                 */
1374                DMEMIT(" %llu/%llu",
1375                       (unsigned long long) sync,
1376                       (unsigned long long) rs->md.resync_max_sectors);
1377
1378                /*
1379                 * Sync action:
1380                 *   See Documentation/device-mapper/dm-raid.c for
1381                 *   information on each of these states.
1382                 */
1383                DMEMIT(" %s", decipher_sync_action(&rs->md));
1384
1385                /*
1386                 * resync_mismatches/mismatch_cnt
1387                 *   This field shows the number of discrepancies found when
1388                 *   performing a "check" of the array.
1389                 */
1390                DMEMIT(" %llu",
1391                       (unsigned long long)
1392                       atomic64_read(&rs->md.resync_mismatches));
1393                break;
1394        case STATUSTYPE_TABLE:
1395                /* The string you would use to construct this array */
1396                for (i = 0; i < rs->md.raid_disks; i++) {
1397                        if ((rs->print_flags & DMPF_REBUILD) &&
1398                            rs->dev[i].data_dev &&
1399                            !test_bit(In_sync, &rs->dev[i].rdev.flags))
1400                                raid_param_cnt += 2; /* for rebuilds */
1401                        if (rs->dev[i].data_dev &&
1402                            test_bit(WriteMostly, &rs->dev[i].rdev.flags))
1403                                raid_param_cnt += 2;
1404                }
1405
1406                raid_param_cnt += (hweight32(rs->print_flags & ~DMPF_REBUILD) * 2);
1407                if (rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC))
1408                        raid_param_cnt--;
1409
1410                DMEMIT("%s %u %u", rs->raid_type->name,
1411                       raid_param_cnt, rs->md.chunk_sectors);
1412
1413                if ((rs->print_flags & DMPF_SYNC) &&
1414                    (rs->md.recovery_cp == MaxSector))
1415                        DMEMIT(" sync");
1416                if (rs->print_flags & DMPF_NOSYNC)
1417                        DMEMIT(" nosync");
1418
1419                for (i = 0; i < rs->md.raid_disks; i++)
1420                        if ((rs->print_flags & DMPF_REBUILD) &&
1421                            rs->dev[i].data_dev &&
1422                            !test_bit(In_sync, &rs->dev[i].rdev.flags))
1423                                DMEMIT(" rebuild %u", i);
1424
1425                if (rs->print_flags & DMPF_DAEMON_SLEEP)
1426                        DMEMIT(" daemon_sleep %lu",
1427                               rs->md.bitmap_info.daemon_sleep);
1428
1429                if (rs->print_flags & DMPF_MIN_RECOVERY_RATE)
1430                        DMEMIT(" min_recovery_rate %d", rs->md.sync_speed_min);
1431
1432                if (rs->print_flags & DMPF_MAX_RECOVERY_RATE)
1433                        DMEMIT(" max_recovery_rate %d", rs->md.sync_speed_max);
1434
1435                for (i = 0; i < rs->md.raid_disks; i++)
1436                        if (rs->dev[i].data_dev &&
1437                            test_bit(WriteMostly, &rs->dev[i].rdev.flags))
1438                                DMEMIT(" write_mostly %u", i);
1439
1440                if (rs->print_flags & DMPF_MAX_WRITE_BEHIND)
1441                        DMEMIT(" max_write_behind %lu",
1442                               rs->md.bitmap_info.max_write_behind);
1443
1444                if (rs->print_flags & DMPF_STRIPE_CACHE) {
1445                        struct r5conf *conf = rs->md.private;
1446
1447                        /* convert from kiB to sectors */
1448                        DMEMIT(" stripe_cache %d",
1449                               conf ? conf->max_nr_stripes * 2 : 0);
1450                }
1451
1452                if (rs->print_flags & DMPF_REGION_SIZE)
1453                        DMEMIT(" region_size %lu",
1454                               rs->md.bitmap_info.chunksize >> 9);
1455
1456                if (rs->print_flags & DMPF_RAID10_COPIES)
1457                        DMEMIT(" raid10_copies %u",
1458                               raid10_md_layout_to_copies(rs->md.layout));
1459
1460                if (rs->print_flags & DMPF_RAID10_FORMAT)
1461                        DMEMIT(" raid10_format %s",
1462                               raid10_md_layout_to_format(rs->md.layout));
1463
1464                DMEMIT(" %d", rs->md.raid_disks);
1465                for (i = 0; i < rs->md.raid_disks; i++) {
1466                        if (rs->dev[i].meta_dev)
1467                                DMEMIT(" %s", rs->dev[i].meta_dev->name);
1468                        else
1469                                DMEMIT(" -");
1470
1471                        if (rs->dev[i].data_dev)
1472                                DMEMIT(" %s", rs->dev[i].data_dev->name);
1473                        else
1474                                DMEMIT(" -");
1475                }
1476        }
1477}
1478
1479static int raid_message(struct dm_target *ti, unsigned argc, char **argv)
1480{
1481        struct raid_set *rs = ti->private;
1482        struct mddev *mddev = &rs->md;
1483
1484        if (!strcasecmp(argv[0], "reshape")) {
1485                DMERR("Reshape not supported.");
1486                return -EINVAL;
1487        }
1488
1489        if (!mddev->pers || !mddev->pers->sync_request)
1490                return -EINVAL;
1491
1492        if (!strcasecmp(argv[0], "frozen"))
1493                set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
1494        else
1495                clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
1496
1497        if (!strcasecmp(argv[0], "idle") || !strcasecmp(argv[0], "frozen")) {
1498                if (mddev->sync_thread) {
1499                        set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1500                        md_reap_sync_thread(mddev);
1501                }
1502        } else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
1503                   test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
1504                return -EBUSY;
1505        else if (!strcasecmp(argv[0], "resync"))
1506                set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
1507        else if (!strcasecmp(argv[0], "recover")) {
1508                set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
1509                set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
1510        } else {
1511                if (!strcasecmp(argv[0], "check"))
1512                        set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
1513                else if (!!strcasecmp(argv[0], "repair"))
1514                        return -EINVAL;
1515                set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
1516                set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
1517        }
1518        if (mddev->ro == 2) {
1519                /* A write to sync_action is enough to justify
1520                 * canceling read-auto mode
1521                 */
1522                mddev->ro = 0;
1523                if (!mddev->suspended)
1524                        md_wakeup_thread(mddev->sync_thread);
1525        }
1526        set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
1527        if (!mddev->suspended)
1528                md_wakeup_thread(mddev->thread);
1529
1530        return 0;
1531}
1532
1533static int raid_iterate_devices(struct dm_target *ti,
1534                                iterate_devices_callout_fn fn, void *data)
1535{
1536        struct raid_set *rs = ti->private;
1537        unsigned i;
1538        int ret = 0;
1539
1540        for (i = 0; !ret && i < rs->md.raid_disks; i++)
1541                if (rs->dev[i].data_dev)
1542                        ret = fn(ti,
1543                                 rs->dev[i].data_dev,
1544                                 0, /* No offset on data devs */
1545                                 rs->md.dev_sectors,
1546                                 data);
1547
1548        return ret;
1549}
1550
1551static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
1552{
1553        struct raid_set *rs = ti->private;
1554        unsigned chunk_size = rs->md.chunk_sectors << 9;
1555        struct r5conf *conf = rs->md.private;
1556
1557        blk_limits_io_min(limits, chunk_size);
1558        blk_limits_io_opt(limits, chunk_size * (conf->raid_disks - conf->max_degraded));
1559}
1560
1561static void raid_presuspend(struct dm_target *ti)
1562{
1563        struct raid_set *rs = ti->private;
1564
1565        md_stop_writes(&rs->md);
1566}
1567
1568static void raid_postsuspend(struct dm_target *ti)
1569{
1570        struct raid_set *rs = ti->private;
1571
1572        mddev_suspend(&rs->md);
1573}
1574
1575static void raid_resume(struct dm_target *ti)
1576{
1577        struct raid_set *rs = ti->private;
1578
1579        set_bit(MD_CHANGE_DEVS, &rs->md.flags);
1580        if (!rs->bitmap_loaded) {
1581                bitmap_load(&rs->md);
1582                rs->bitmap_loaded = 1;
1583        }
1584
1585        clear_bit(MD_RECOVERY_FROZEN, &rs->md.recovery);
1586        mddev_resume(&rs->md);
1587}
1588
1589static struct target_type raid_target = {
1590        .name = "raid",
1591        .version = {1, 5, 0},
1592        .module = THIS_MODULE,
1593        .ctr = raid_ctr,
1594        .dtr = raid_dtr,
1595        .map = raid_map,
1596        .status = raid_status,
1597        .message = raid_message,
1598        .iterate_devices = raid_iterate_devices,
1599        .io_hints = raid_io_hints,
1600        .presuspend = raid_presuspend,
1601        .postsuspend = raid_postsuspend,
1602        .resume = raid_resume,
1603};
1604
1605static int __init dm_raid_init(void)
1606{
1607        DMINFO("Loading target version %u.%u.%u",
1608               raid_target.version[0],
1609               raid_target.version[1],
1610               raid_target.version[2]);
1611        return dm_register_target(&raid_target);
1612}
1613
1614static void __exit dm_raid_exit(void)
1615{
1616        dm_unregister_target(&raid_target);
1617}
1618
1619module_init(dm_raid_init);
1620module_exit(dm_raid_exit);
1621
1622MODULE_DESCRIPTION(DM_NAME " raid4/5/6 target");
1623MODULE_ALIAS("dm-raid1");
1624MODULE_ALIAS("dm-raid10");
1625MODULE_ALIAS("dm-raid4");
1626MODULE_ALIAS("dm-raid5");
1627MODULE_ALIAS("dm-raid6");
1628MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>");
1629MODULE_LICENSE("GPL");
1630
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