drivers/md/dm-raid.c

   1 /*
   2  * Copyright (C) 2010-2011 Neil Brown
   3  * Copyright (C) 2010-2017 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 "md-bitmap.h"
  16
  17 #include <linux/device-mapper.h>
  18
  19 #define DM_MSG_PREFIX "raid"
  20 #define MAX_RAID_DEVICES        253 /* md-raid kernel limit */
  21
  22 /*
  23  * Minimum sectors of free reshape space per raid device
  24  */
  25 #define MIN_FREE_RESHAPE_SPACE to_sector(4*4096)
  26
  27 /*
  28  * Minimum journal space 4 MiB in sectors.
  29  */
  30 #define MIN_RAID456_JOURNAL_SPACE (4*2048)
  31
  32 /* Global list of all raid sets */
  33 static LIST_HEAD(raid_sets);
  34
  35 static bool devices_handle_discard_safely = false;
  36
  37 /*
  38  * The following flags are used by dm-raid.c to set up the array state.
  39  * They must be cleared before md_run is called.
  40  */
  41 #define FirstUse 10             /* rdev flag */
  42
  43 struct raid_dev {
  44         /*
  45          * Two DM devices, one to hold metadata and one to hold the
  46          * actual data/parity.  The reason for this is to not confuse
  47          * ti->len and give more flexibility in altering size and
  48          * characteristics.
  49          *
  50          * While it is possible for this device to be associated
  51          * with a different physical device than the data_dev, it
  52          * is intended for it to be the same.
  53          *    |--------- Physical Device ---------|
  54          *    |- meta_dev -|------ data_dev ------|
  55          */
  56         struct dm_dev *meta_dev;
  57         struct dm_dev *data_dev;
  58         struct md_rdev rdev;
  59 };
  60
  61 /*
  62  * Bits for establishing rs->ctr_flags
  63  *
  64  * 1 = no flag value
  65  * 2 = flag with value
  66  */
  67 #define __CTR_FLAG_SYNC                 0  /* 1 */ /* Not with raid0! */
  68 #define __CTR_FLAG_NOSYNC               1  /* 1 */ /* Not with raid0! */
  69 #define __CTR_FLAG_REBUILD              2  /* 2 */ /* Not with raid0! */
  70 #define __CTR_FLAG_DAEMON_SLEEP         3  /* 2 */ /* Not with raid0! */
  71 #define __CTR_FLAG_MIN_RECOVERY_RATE    4  /* 2 */ /* Not with raid0! */
  72 #define __CTR_FLAG_MAX_RECOVERY_RATE    5  /* 2 */ /* Not with raid0! */
  73 #define __CTR_FLAG_MAX_WRITE_BEHIND     6  /* 2 */ /* Only with raid1! */
  74 #define __CTR_FLAG_WRITE_MOSTLY         7  /* 2 */ /* Only with raid1! */
  75 #define __CTR_FLAG_STRIPE_CACHE         8  /* 2 */ /* Only with raid4/5/6! */
  76 #define __CTR_FLAG_REGION_SIZE          9  /* 2 */ /* Not with raid0! */
  77 #define __CTR_FLAG_RAID10_COPIES        10 /* 2 */ /* Only with raid10 */
  78 #define __CTR_FLAG_RAID10_FORMAT        11 /* 2 */ /* Only with raid10 */
  79 /* New for v1.9.0 */
  80 #define __CTR_FLAG_DELTA_DISKS          12 /* 2 */ /* Only with reshapable raid1/4/5/6/10! */
  81 #define __CTR_FLAG_DATA_OFFSET          13 /* 2 */ /* Only with reshapable raid4/5/6/10! */
  82 #define __CTR_FLAG_RAID10_USE_NEAR_SETS 14 /* 2 */ /* Only with raid10! */
  83
  84 /* New for v1.10.0 */
  85 #define __CTR_FLAG_JOURNAL_DEV          15 /* 2 */ /* Only with raid4/5/6 (journal device)! */
  86
  87 /* New for v1.11.1 */
  88 #define __CTR_FLAG_JOURNAL_MODE         16 /* 2 */ /* Only with raid4/5/6 (journal mode)! */
  89
  90 /*
  91  * Flags for rs->ctr_flags field.
  92  */
  93 #define CTR_FLAG_SYNC                   (1 << __CTR_FLAG_SYNC)
  94 #define CTR_FLAG_NOSYNC                 (1 << __CTR_FLAG_NOSYNC)
  95 #define CTR_FLAG_REBUILD                (1 << __CTR_FLAG_REBUILD)
  96 #define CTR_FLAG_DAEMON_SLEEP           (1 << __CTR_FLAG_DAEMON_SLEEP)
  97 #define CTR_FLAG_MIN_RECOVERY_RATE      (1 << __CTR_FLAG_MIN_RECOVERY_RATE)
  98 #define CTR_FLAG_MAX_RECOVERY_RATE      (1 << __CTR_FLAG_MAX_RECOVERY_RATE)
  99 #define CTR_FLAG_MAX_WRITE_BEHIND       (1 << __CTR_FLAG_MAX_WRITE_BEHIND)
 100 #define CTR_FLAG_WRITE_MOSTLY           (1 << __CTR_FLAG_WRITE_MOSTLY)
 101 #define CTR_FLAG_STRIPE_CACHE           (1 << __CTR_FLAG_STRIPE_CACHE)
 102 #define CTR_FLAG_REGION_SIZE            (1 << __CTR_FLAG_REGION_SIZE)
 103 #define CTR_FLAG_RAID10_COPIES          (1 << __CTR_FLAG_RAID10_COPIES)
 104 #define CTR_FLAG_RAID10_FORMAT          (1 << __CTR_FLAG_RAID10_FORMAT)
 105 #define CTR_FLAG_DELTA_DISKS            (1 << __CTR_FLAG_DELTA_DISKS)
 106 #define CTR_FLAG_DATA_OFFSET            (1 << __CTR_FLAG_DATA_OFFSET)
 107 #define CTR_FLAG_RAID10_USE_NEAR_SETS   (1 << __CTR_FLAG_RAID10_USE_NEAR_SETS)
 108 #define CTR_FLAG_JOURNAL_DEV            (1 << __CTR_FLAG_JOURNAL_DEV)
 109 #define CTR_FLAG_JOURNAL_MODE           (1 << __CTR_FLAG_JOURNAL_MODE)
 110
 111 /*
 112  * Definitions of various constructor flags to
 113  * be used in checks of valid / invalid flags
 114  * per raid level.
 115  */
 116 /* Define all any sync flags */
 117 #define CTR_FLAGS_ANY_SYNC              (CTR_FLAG_SYNC | CTR_FLAG_NOSYNC)
 118
 119 /* Define flags for options without argument (e.g. 'nosync') */
 120 #define CTR_FLAG_OPTIONS_NO_ARGS        (CTR_FLAGS_ANY_SYNC | \
 121                                          CTR_FLAG_RAID10_USE_NEAR_SETS)
 122
 123 /* Define flags for options with one argument (e.g. 'delta_disks +2') */
 124 #define CTR_FLAG_OPTIONS_ONE_ARG (CTR_FLAG_REBUILD | \
 125                                   CTR_FLAG_WRITE_MOSTLY | \
 126                                   CTR_FLAG_DAEMON_SLEEP | \
 127                                   CTR_FLAG_MIN_RECOVERY_RATE | \
 128                                   CTR_FLAG_MAX_RECOVERY_RATE | \
 129                                   CTR_FLAG_MAX_WRITE_BEHIND | \
 130                                   CTR_FLAG_STRIPE_CACHE | \
 131                                   CTR_FLAG_REGION_SIZE | \
 132                                   CTR_FLAG_RAID10_COPIES | \
 133                                   CTR_FLAG_RAID10_FORMAT | \
 134                                   CTR_FLAG_DELTA_DISKS | \
 135                                   CTR_FLAG_DATA_OFFSET)
 136
 137 /* Valid options definitions per raid level... */
 138
 139 /* "raid0" does only accept data offset */
 140 #define RAID0_VALID_FLAGS       (CTR_FLAG_DATA_OFFSET)
 141
 142 /* "raid1" does not accept stripe cache, data offset, delta_disks or any raid10 options */
 143 #define RAID1_VALID_FLAGS       (CTR_FLAGS_ANY_SYNC | \
 144                                  CTR_FLAG_REBUILD | \
 145                                  CTR_FLAG_WRITE_MOSTLY | \
 146                                  CTR_FLAG_DAEMON_SLEEP | \
 147                                  CTR_FLAG_MIN_RECOVERY_RATE | \
 148                                  CTR_FLAG_MAX_RECOVERY_RATE | \
 149                                  CTR_FLAG_MAX_WRITE_BEHIND | \
 150                                  CTR_FLAG_REGION_SIZE | \
 151                                  CTR_FLAG_DELTA_DISKS | \
 152                                  CTR_FLAG_DATA_OFFSET)
 153
 154 /* "raid10" does not accept any raid1 or stripe cache options */
 155 #define RAID10_VALID_FLAGS      (CTR_FLAGS_ANY_SYNC | \
 156                                  CTR_FLAG_REBUILD | \
 157                                  CTR_FLAG_DAEMON_SLEEP | \
 158                                  CTR_FLAG_MIN_RECOVERY_RATE | \
 159                                  CTR_FLAG_MAX_RECOVERY_RATE | \
 160                                  CTR_FLAG_REGION_SIZE | \
 161                                  CTR_FLAG_RAID10_COPIES | \
 162                                  CTR_FLAG_RAID10_FORMAT | \
 163                                  CTR_FLAG_DELTA_DISKS | \
 164                                  CTR_FLAG_DATA_OFFSET | \
 165                                  CTR_FLAG_RAID10_USE_NEAR_SETS)
 166
 167 /*
 168  * "raid4/5/6" do not accept any raid1 or raid10 specific options
 169  *
 170  * "raid6" does not accept "nosync", because it is not guaranteed
 171  * that both parity and q-syndrome are being written properly with
 172  * any writes
 173  */
 174 #define RAID45_VALID_FLAGS      (CTR_FLAGS_ANY_SYNC | \
 175                                  CTR_FLAG_REBUILD | \
 176                                  CTR_FLAG_DAEMON_SLEEP | \
 177                                  CTR_FLAG_MIN_RECOVERY_RATE | \
 178                                  CTR_FLAG_MAX_RECOVERY_RATE | \
 179                                  CTR_FLAG_STRIPE_CACHE | \
 180                                  CTR_FLAG_REGION_SIZE | \
 181                                  CTR_FLAG_DELTA_DISKS | \
 182                                  CTR_FLAG_DATA_OFFSET | \
 183                                  CTR_FLAG_JOURNAL_DEV | \
 184                                  CTR_FLAG_JOURNAL_MODE)
 185
 186 #define RAID6_VALID_FLAGS       (CTR_FLAG_SYNC | \
 187                                  CTR_FLAG_REBUILD | \
 188                                  CTR_FLAG_DAEMON_SLEEP | \
 189                                  CTR_FLAG_MIN_RECOVERY_RATE | \
 190                                  CTR_FLAG_MAX_RECOVERY_RATE | \
 191                                  CTR_FLAG_STRIPE_CACHE | \
 192                                  CTR_FLAG_REGION_SIZE | \
 193                                  CTR_FLAG_DELTA_DISKS | \
 194                                  CTR_FLAG_DATA_OFFSET | \
 195                                  CTR_FLAG_JOURNAL_DEV | \
 196                                  CTR_FLAG_JOURNAL_MODE)
 197 /* ...valid options definitions per raid level */
 198
 199 /*
 200  * Flags for rs->runtime_flags field
 201  * (RT_FLAG prefix meaning "runtime flag")
 202  *
 203  * These are all internal and used to define runtime state,
 204  * e.g. to prevent another resume from preresume processing
 205  * the raid set all over again.
 206  */
 207 #define RT_FLAG_RS_PRERESUMED           0
 208 #define RT_FLAG_RS_RESUMED              1
 209 #define RT_FLAG_RS_BITMAP_LOADED        2
 210 #define RT_FLAG_UPDATE_SBS              3
 211 #define RT_FLAG_RESHAPE_RS              4
 212 #define RT_FLAG_RS_SUSPENDED            5
 213 #define RT_FLAG_RS_IN_SYNC              6
 214 #define RT_FLAG_RS_RESYNCING            7
 215
 216 /* Array elements of 64 bit needed for rebuild/failed disk bits */
 217 #define DISKS_ARRAY_ELEMS ((MAX_RAID_DEVICES + (sizeof(uint64_t) * 8 - 1)) / sizeof(uint64_t) / 8)
 218
 219 /*
 220  * raid set level, layout and chunk sectors backup/restore
 221  */
 222 struct rs_layout {
 223         int new_level;
 224         int new_layout;
 225         int new_chunk_sectors;
 226 };
 227
 228 struct raid_set {
 229         struct dm_target *ti;
 230         struct list_head list;
 231
 232         uint32_t stripe_cache_entries;
 233         unsigned long ctr_flags;
 234         unsigned long runtime_flags;
 235
 236         uint64_t rebuild_disks[DISKS_ARRAY_ELEMS];
 237
 238         int raid_disks;
 239         int delta_disks;
 240         int data_offset;
 241         int raid10_copies;
 242         int requested_bitmap_chunk_sectors;
 243
 244         struct mddev md;
 245         struct raid_type *raid_type;
 246         struct dm_target_callbacks callbacks;
 247
 248         /* Optional raid4/5/6 journal device */
 249         struct journal_dev {
 250                 struct dm_dev *dev;
 251                 struct md_rdev rdev;
 252                 int mode;
 253         } journal_dev;
 254
 255         struct raid_dev dev[0];
 256 };
 257
 258 static void rs_config_backup(struct raid_set *rs, struct rs_layout *l)
 259 {
 260         struct mddev *mddev = &rs->md;
 261
 262         l->new_level = mddev->new_level;
 263         l->new_layout = mddev->new_layout;
 264         l->new_chunk_sectors = mddev->new_chunk_sectors;
 265 }
 266
 267 static void rs_config_restore(struct raid_set *rs, struct rs_layout *l)
 268 {
 269         struct mddev *mddev = &rs->md;
 270
 271         mddev->new_level = l->new_level;
 272         mddev->new_layout = l->new_layout;
 273         mddev->new_chunk_sectors = l->new_chunk_sectors;
 274 }
 275
 276 /* Find any raid_set in active slot for @rs on global list */
 277 static struct raid_set *rs_find_active(struct raid_set *rs)
 278 {
 279         struct raid_set *r;
 280         struct mapped_device *md = dm_table_get_md(rs->ti->table);
 281
 282         list_for_each_entry(r, &raid_sets, list)
 283                 if (r != rs && dm_table_get_md(r->ti->table) == md)
 284                         return r;
 285
 286         return NULL;
 287 }
 288
 289 /* raid10 algorithms (i.e. formats) */
 290 #define ALGORITHM_RAID10_DEFAULT        0
 291 #define ALGORITHM_RAID10_NEAR           1
 292 #define ALGORITHM_RAID10_OFFSET         2
 293 #define ALGORITHM_RAID10_FAR            3
 294
 295 /* Supported raid types and properties. */
 296 static struct raid_type {
 297         const char *name;               /* RAID algorithm. */
 298         const char *descr;              /* Descriptor text for logging. */
 299         const unsigned int parity_devs; /* # of parity devices. */
 300         const unsigned int minimal_devs;/* minimal # of devices in set. */
 301         const unsigned int level;       /* RAID level. */
 302         const unsigned int algorithm;   /* RAID algorithm. */
 303 } raid_types[] = {
 304         {"raid0",         "raid0 (striping)",                       0, 2, 0,  0 /* NONE */},
 305         {"raid1",         "raid1 (mirroring)",                      0, 2, 1,  0 /* NONE */},
 306         {"raid10_far",    "raid10 far (striped mirrors)",           0, 2, 10, ALGORITHM_RAID10_FAR},
 307         {"raid10_offset", "raid10 offset (striped mirrors)",        0, 2, 10, ALGORITHM_RAID10_OFFSET},
 308         {"raid10_near",   "raid10 near (striped mirrors)",          0, 2, 10, ALGORITHM_RAID10_NEAR},
 309         {"raid10",        "raid10 (striped mirrors)",               0, 2, 10, ALGORITHM_RAID10_DEFAULT},
 310         {"raid4",         "raid4 (dedicated first parity disk)",    1, 2, 5,  ALGORITHM_PARITY_0}, /* raid4 layout = raid5_0 */
 311         {"raid5_n",       "raid5 (dedicated last parity disk)",     1, 2, 5,  ALGORITHM_PARITY_N},
 312         {"raid5_ls",      "raid5 (left symmetric)",                 1, 2, 5,  ALGORITHM_LEFT_SYMMETRIC},
 313         {"raid5_rs",      "raid5 (right symmetric)",                1, 2, 5,  ALGORITHM_RIGHT_SYMMETRIC},
 314         {"raid5_la",      "raid5 (left asymmetric)",                1, 2, 5,  ALGORITHM_LEFT_ASYMMETRIC},
 315         {"raid5_ra",      "raid5 (right asymmetric)",               1, 2, 5,  ALGORITHM_RIGHT_ASYMMETRIC},
 316         {"raid6_zr",      "raid6 (zero restart)",                   2, 4, 6,  ALGORITHM_ROTATING_ZERO_RESTART},
 317         {"raid6_nr",      "raid6 (N restart)",                      2, 4, 6,  ALGORITHM_ROTATING_N_RESTART},
 318         {"raid6_nc",      "raid6 (N continue)",                     2, 4, 6,  ALGORITHM_ROTATING_N_CONTINUE},
 319         {"raid6_n_6",     "raid6 (dedicated parity/Q n/6)",         2, 4, 6,  ALGORITHM_PARITY_N_6},
 320         {"raid6_ls_6",    "raid6 (left symmetric dedicated Q 6)",   2, 4, 6,  ALGORITHM_LEFT_SYMMETRIC_6},
 321         {"raid6_rs_6",    "raid6 (right symmetric dedicated Q 6)",  2, 4, 6,  ALGORITHM_RIGHT_SYMMETRIC_6},
 322         {"raid6_la_6",    "raid6 (left asymmetric dedicated Q 6)",  2, 4, 6,  ALGORITHM_LEFT_ASYMMETRIC_6},
 323         {"raid6_ra_6",    "raid6 (right asymmetric dedicated Q 6)", 2, 4, 6,  ALGORITHM_RIGHT_ASYMMETRIC_6}
 324 };
 325
 326 /* True, if @v is in inclusive range [@min, @max] */
 327 static bool __within_range(long v, long min, long max)
 328 {
 329         return v >= min && v <= max;
 330 }
 331
 332 /* All table line arguments are defined here */
 333 static struct arg_name_flag {
 334         const unsigned long flag;
 335         const char *name;
 336 } __arg_name_flags[] = {
 337         { CTR_FLAG_SYNC, "sync"},
 338         { CTR_FLAG_NOSYNC, "nosync"},
 339         { CTR_FLAG_REBUILD, "rebuild"},
 340         { CTR_FLAG_DAEMON_SLEEP, "daemon_sleep"},
 341         { CTR_FLAG_MIN_RECOVERY_RATE, "min_recovery_rate"},
 342         { CTR_FLAG_MAX_RECOVERY_RATE, "max_recovery_rate"},
 343         { CTR_FLAG_MAX_WRITE_BEHIND, "max_write_behind"},
 344         { CTR_FLAG_WRITE_MOSTLY, "write_mostly"},
 345         { CTR_FLAG_STRIPE_CACHE, "stripe_cache"},
 346         { CTR_FLAG_REGION_SIZE, "region_size"},
 347         { CTR_FLAG_RAID10_COPIES, "raid10_copies"},
 348         { CTR_FLAG_RAID10_FORMAT, "raid10_format"},
 349         { CTR_FLAG_DATA_OFFSET, "data_offset"},
 350         { CTR_FLAG_DELTA_DISKS, "delta_disks"},
 351         { CTR_FLAG_RAID10_USE_NEAR_SETS, "raid10_use_near_sets"},
 352         { CTR_FLAG_JOURNAL_DEV, "journal_dev" },
 353         { CTR_FLAG_JOURNAL_MODE, "journal_mode" },
 354 };
 355
 356 /* Return argument name string for given @flag */
 357 static const char *dm_raid_arg_name_by_flag(const uint32_t flag)
 358 {
 359         if (hweight32(flag) == 1) {
 360                 struct arg_name_flag *anf = __arg_name_flags + ARRAY_SIZE(__arg_name_flags);
 361
 362                 while (anf-- > __arg_name_flags)
 363                         if (flag & anf->flag)
 364                                 return anf->name;
 365
 366         } else
 367                 DMERR("%s called with more than one flag!", __func__);
 368
 369         return NULL;
 370 }
 371
 372 /* Define correlation of raid456 journal cache modes and dm-raid target line parameters */
 373 static struct {
 374         const int mode;
 375         const char *param;
 376 } _raid456_journal_mode[] = {
 377         { R5C_JOURNAL_MODE_WRITE_THROUGH , "writethrough" },
 378         { R5C_JOURNAL_MODE_WRITE_BACK    , "writeback" }
 379 };
 380
 381 /* Return MD raid4/5/6 journal mode for dm @journal_mode one */
 382 static int dm_raid_journal_mode_to_md(const char *mode)
 383 {
 384         int m = ARRAY_SIZE(_raid456_journal_mode);
 385
 386         while (m--)
 387                 if (!strcasecmp(mode, _raid456_journal_mode[m].param))
 388                         return _raid456_journal_mode[m].mode;
 389
 390         return -EINVAL;
 391 }
 392
 393 /* Return dm-raid raid4/5/6 journal mode string for @mode */
 394 static const char *md_journal_mode_to_dm_raid(const int mode)
 395 {
 396         int m = ARRAY_SIZE(_raid456_journal_mode);
 397
 398         while (m--)
 399                 if (mode == _raid456_journal_mode[m].mode)
 400                         return _raid456_journal_mode[m].param;
 401
 402         return "unknown";
 403 }
 404
 405 /*
 406  * Bool helpers to test for various raid levels of a raid set.
 407  * It's level as reported by the superblock rather than
 408  * the requested raid_type passed to the constructor.
 409  */
 410 /* Return true, if raid set in @rs is raid0 */
 411 static bool rs_is_raid0(struct raid_set *rs)
 412 {
 413         return !rs->md.level;
 414 }
 415
 416 /* Return true, if raid set in @rs is raid1 */
 417 static bool rs_is_raid1(struct raid_set *rs)
 418 {
 419         return rs->md.level == 1;
 420 }
 421
 422 /* Return true, if raid set in @rs is raid10 */
 423 static bool rs_is_raid10(struct raid_set *rs)
 424 {
 425         return rs->md.level == 10;
 426 }
 427
 428 /* Return true, if raid set in @rs is level 6 */
 429 static bool rs_is_raid6(struct raid_set *rs)
 430 {
 431         return rs->md.level == 6;
 432 }
 433
 434 /* Return true, if raid set in @rs is level 4, 5 or 6 */
 435 static bool rs_is_raid456(struct raid_set *rs)
 436 {
 437         return __within_range(rs->md.level, 4, 6);
 438 }
 439
 440 /* Return true, if raid set in @rs is reshapable */
 441 static bool __is_raid10_far(int layout);
 442 static bool rs_is_reshapable(struct raid_set *rs)
 443 {
 444         return rs_is_raid456(rs) ||
 445                (rs_is_raid10(rs) && !__is_raid10_far(rs->md.new_layout));
 446 }
 447
 448 /* Return true, if raid set in @rs is recovering */
 449 static bool rs_is_recovering(struct raid_set *rs)
 450 {
 451         return rs->md.recovery_cp < rs->md.dev_sectors;
 452 }
 453
 454 /* Return true, if raid set in @rs is reshaping */
 455 static bool rs_is_reshaping(struct raid_set *rs)
 456 {
 457         return rs->md.reshape_position != MaxSector;
 458 }
 459
 460 /*
 461  * bool helpers to test for various raid levels of a raid type @rt
 462  */
 463
 464 /* Return true, if raid type in @rt is raid0 */
 465 static bool rt_is_raid0(struct raid_type *rt)
 466 {
 467         return !rt->level;
 468 }
 469
 470 /* Return true, if raid type in @rt is raid1 */
 471 static bool rt_is_raid1(struct raid_type *rt)
 472 {
 473         return rt->level == 1;
 474 }
 475
 476 /* Return true, if raid type in @rt is raid10 */
 477 static bool rt_is_raid10(struct raid_type *rt)
 478 {
 479         return rt->level == 10;
 480 }
 481
 482 /* Return true, if raid type in @rt is raid4/5 */
 483 static bool rt_is_raid45(struct raid_type *rt)
 484 {
 485         return __within_range(rt->level, 4, 5);
 486 }
 487
 488 /* Return true, if raid type in @rt is raid6 */
 489 static bool rt_is_raid6(struct raid_type *rt)
 490 {
 491         return rt->level == 6;
 492 }
 493
 494 /* Return true, if raid type in @rt is raid4/5/6 */
 495 static bool rt_is_raid456(struct raid_type *rt)
 496 {
 497         return __within_range(rt->level, 4, 6);
 498 }
 499 /* END: raid level bools */
 500
 501 /* Return valid ctr flags for the raid level of @rs */
 502 static unsigned long __valid_flags(struct raid_set *rs)
 503 {
 504         if (rt_is_raid0(rs->raid_type))
 505                 return RAID0_VALID_FLAGS;
 506         else if (rt_is_raid1(rs->raid_type))
 507                 return RAID1_VALID_FLAGS;
 508         else if (rt_is_raid10(rs->raid_type))
 509                 return RAID10_VALID_FLAGS;
 510         else if (rt_is_raid45(rs->raid_type))
 511                 return RAID45_VALID_FLAGS;
 512         else if (rt_is_raid6(rs->raid_type))
 513                 return RAID6_VALID_FLAGS;
 514
 515         return 0;
 516 }
 517
 518 /*
 519  * Check for valid flags set on @rs
 520  *
 521  * Has to be called after parsing of the ctr flags!
 522  */
 523 static int rs_check_for_valid_flags(struct raid_set *rs)
 524 {
 525         if (rs->ctr_flags & ~__valid_flags(rs)) {
 526                 rs->ti->error = "Invalid flags combination";
 527                 return -EINVAL;
 528         }
 529
 530         return 0;
 531 }
 532
 533 /* MD raid10 bit definitions and helpers */
 534 #define RAID10_OFFSET                   (1 << 16) /* stripes with data copies area adjacent on devices */
 535 #define RAID10_BROCKEN_USE_FAR_SETS     (1 << 17) /* Broken in raid10.c: use sets instead of whole stripe rotation */
 536 #define RAID10_USE_FAR_SETS             (1 << 18) /* Use sets instead of whole stripe rotation */
 537 #define RAID10_FAR_COPIES_SHIFT         8         /* raid10 # far copies shift (2nd byte of layout) */
 538
 539 /* Return md raid10 near copies for @layout */
 540 static unsigned int __raid10_near_copies(int layout)
 541 {
 542         return layout & 0xFF;
 543 }
 544
 545 /* Return md raid10 far copies for @layout */
 546 static unsigned int __raid10_far_copies(int layout)
 547 {
 548         return __raid10_near_copies(layout >> RAID10_FAR_COPIES_SHIFT);
 549 }
 550
 551 /* Return true if md raid10 offset for @layout */
 552 static bool __is_raid10_offset(int layout)
 553 {
 554         return !!(layout & RAID10_OFFSET);
 555 }
 556
 557 /* Return true if md raid10 near for @layout */
 558 static bool __is_raid10_near(int layout)
 559 {
 560         return !__is_raid10_offset(layout) && __raid10_near_copies(layout) > 1;
 561 }
 562
 563 /* Return true if md raid10 far for @layout */
 564 static bool __is_raid10_far(int layout)
 565 {
 566         return !__is_raid10_offset(layout) && __raid10_far_copies(layout) > 1;
 567 }
 568
 569 /* Return md raid10 layout string for @layout */
 570 static const char *raid10_md_layout_to_format(int layout)
 571 {
 572         /*
 573          * Bit 16 stands for "offset"
 574          * (i.e. adjacent stripes hold copies)
 575          *
 576          * Refer to MD's raid10.c for details
 577          */
 578         if (__is_raid10_offset(layout))
 579                 return "offset";
 580
 581         if (__raid10_near_copies(layout) > 1)
 582                 return "near";
 583
 584         if (__raid10_far_copies(layout) > 1)
 585                 return "far";
 586
 587         return "unknown";
 588 }
 589
 590 /* Return md raid10 algorithm for @name */
 591 static const int raid10_name_to_format(const char *name)
 592 {
 593         if (!strcasecmp(name, "near"))
 594                 return ALGORITHM_RAID10_NEAR;
 595         else if (!strcasecmp(name, "offset"))
 596                 return ALGORITHM_RAID10_OFFSET;
 597         else if (!strcasecmp(name, "far"))
 598                 return ALGORITHM_RAID10_FAR;
 599
 600         return -EINVAL;
 601 }
 602
 603 /* Return md raid10 copies for @layout */
 604 static unsigned int raid10_md_layout_to_copies(int layout)
 605 {
 606         return max(__raid10_near_copies(layout), __raid10_far_copies(layout));
 607 }
 608
 609 /* Return md raid10 format id for @format string */
 610 static int raid10_format_to_md_layout(struct raid_set *rs,
 611                                       unsigned int algorithm,
 612                                       unsigned int copies)
 613 {
 614         unsigned int n = 1, f = 1, r = 0;
 615
 616         /*
 617          * MD resilienece flaw:
 618          *
 619          * enabling use_far_sets for far/offset formats causes copies
 620          * to be colocated on the same devs together with their origins!
 621          *
 622          * -> disable it for now in the definition above
 623          */
 624         if (algorithm == ALGORITHM_RAID10_DEFAULT ||
 625             algorithm == ALGORITHM_RAID10_NEAR)
 626                 n = copies;
 627
 628         else if (algorithm == ALGORITHM_RAID10_OFFSET) {
 629                 f = copies;
 630                 r = RAID10_OFFSET;
 631                 if (!test_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags))
 632                         r |= RAID10_USE_FAR_SETS;
 633
 634         } else if (algorithm == ALGORITHM_RAID10_FAR) {
 635                 f = copies;
 636                 r = !RAID10_OFFSET;
 637                 if (!test_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags))
 638                         r |= RAID10_USE_FAR_SETS;
 639
 640         } else
 641                 return -EINVAL;
 642
 643         return r | (f << RAID10_FAR_COPIES_SHIFT) | n;
 644 }
 645 /* END: MD raid10 bit definitions and helpers */
 646
 647 /* Check for any of the raid10 algorithms */
 648 static bool __got_raid10(struct raid_type *rtp, const int layout)
 649 {
 650         if (rtp->level == 10) {
 651                 switch (rtp->algorithm) {
 652                 case ALGORITHM_RAID10_DEFAULT:
 653                 case ALGORITHM_RAID10_NEAR:
 654                         return __is_raid10_near(layout);
 655                 case ALGORITHM_RAID10_OFFSET:
 656                         return __is_raid10_offset(layout);
 657                 case ALGORITHM_RAID10_FAR:
 658                         return __is_raid10_far(layout);
 659                 default:
 660                         break;
 661                 }
 662         }
 663
 664         return false;
 665 }
 666
 667 /* Return raid_type for @name */
 668 static struct raid_type *get_raid_type(const char *name)
 669 {
 670         struct raid_type *rtp = raid_types + ARRAY_SIZE(raid_types);
 671
 672         while (rtp-- > raid_types)
 673                 if (!strcasecmp(rtp->name, name))
 674                         return rtp;
 675
 676         return NULL;
 677 }
 678
 679 /* Return raid_type for @name based derived from @level and @layout */
 680 static struct raid_type *get_raid_type_by_ll(const int level, const int layout)
 681 {
 682         struct raid_type *rtp = raid_types + ARRAY_SIZE(raid_types);
 683
 684         while (rtp-- > raid_types) {
 685                 /* RAID10 special checks based on @layout flags/properties */
 686                 if (rtp->level == level &&
 687                     (__got_raid10(rtp, layout) || rtp->algorithm == layout))
 688                         return rtp;
 689         }
 690
 691         return NULL;
 692 }
 693
 694 /* Adjust rdev sectors */
 695 static void rs_set_rdev_sectors(struct raid_set *rs)
 696 {
 697         struct mddev *mddev = &rs->md;
 698         struct md_rdev *rdev;
 699
 700         /*
 701          * raid10 sets rdev->sector to the device size, which
 702          * is unintended in case of out-of-place reshaping
 703          */
 704         rdev_for_each(rdev, mddev)
 705                 if (!test_bit(Journal, &rdev->flags))
 706                         rdev->sectors = mddev->dev_sectors;
 707 }
 708
 709 /*
 710  * Change bdev capacity of @rs in case of a disk add/remove reshape
 711  */
 712 static void rs_set_capacity(struct raid_set *rs)
 713 {
 714         struct gendisk *gendisk = dm_disk(dm_table_get_md(rs->ti->table));
 715
 716         set_capacity(gendisk, rs->md.array_sectors);
 717         revalidate_disk(gendisk);
 718 }
 719
 720 /*
 721  * Set the mddev properties in @rs to the current
 722  * ones retrieved from the freshest superblock
 723  */
 724 static void rs_set_cur(struct raid_set *rs)
 725 {
 726         struct mddev *mddev = &rs->md;
 727
 728         mddev->new_level = mddev->level;
 729         mddev->new_layout = mddev->layout;
 730         mddev->new_chunk_sectors = mddev->chunk_sectors;
 731 }
 732
 733 /*
 734  * Set the mddev properties in @rs to the new
 735  * ones requested by the ctr
 736  */
 737 static void rs_set_new(struct raid_set *rs)
 738 {
 739         struct mddev *mddev = &rs->md;
 740
 741         mddev->level = mddev->new_level;
 742         mddev->layout = mddev->new_layout;
 743         mddev->chunk_sectors = mddev->new_chunk_sectors;
 744         mddev->raid_disks = rs->raid_disks;
 745         mddev->delta_disks = 0;
 746 }
 747
 748 static struct raid_set *raid_set_alloc(struct dm_target *ti, struct raid_type *raid_type,
 749                                        unsigned int raid_devs)
 750 {
 751         unsigned int i;
 752         struct raid_set *rs;
 753
 754         if (raid_devs <= raid_type->parity_devs) {
 755                 ti->error = "Insufficient number of devices";
 756                 return ERR_PTR(-EINVAL);
 757         }
 758
 759         rs = kzalloc(sizeof(*rs) + raid_devs * sizeof(rs->dev[0]), GFP_KERNEL);
 760         if (!rs) {
 761                 ti->error = "Cannot allocate raid context";
 762                 return ERR_PTR(-ENOMEM);
 763         }
 764
 765         mddev_init(&rs->md);
 766
 767         INIT_LIST_HEAD(&rs->list);
 768         rs->raid_disks = raid_devs;
 769         rs->delta_disks = 0;
 770
 771         rs->ti = ti;
 772         rs->raid_type = raid_type;
 773         rs->stripe_cache_entries = 256;
 774         rs->md.raid_disks = raid_devs;
 775         rs->md.level = raid_type->level;
 776         rs->md.new_level = rs->md.level;
 777         rs->md.layout = raid_type->algorithm;
 778         rs->md.new_layout = rs->md.layout;
 779         rs->md.delta_disks = 0;
 780         rs->md.recovery_cp = MaxSector;
 781
 782         for (i = 0; i < raid_devs; i++)
 783                 md_rdev_init(&rs->dev[i].rdev);
 784
 785         /* Add @rs to global list. */
 786         list_add(&rs->list, &raid_sets);
 787
 788         /*
 789          * Remaining items to be initialized by further RAID params:
 790          *  rs->md.persistent
 791          *  rs->md.external
 792          *  rs->md.chunk_sectors
 793          *  rs->md.new_chunk_sectors
 794          *  rs->md.dev_sectors
 795          */
 796
 797         return rs;
 798 }
 799
 800 /* Free all @rs allocations and remove it from global list. */
 801 static void raid_set_free(struct raid_set *rs)
 802 {
 803         int i;
 804
 805         if (rs->journal_dev.dev) {
 806                 md_rdev_clear(&rs->journal_dev.rdev);
 807                 dm_put_device(rs->ti, rs->journal_dev.dev);
 808         }
 809
 810         for (i = 0; i < rs->raid_disks; i++) {
 811                 if (rs->dev[i].meta_dev)
 812                         dm_put_device(rs->ti, rs->dev[i].meta_dev);
 813                 md_rdev_clear(&rs->dev[i].rdev);
 814                 if (rs->dev[i].data_dev)
 815                         dm_put_device(rs->ti, rs->dev[i].data_dev);
 816         }
 817
 818         list_del(&rs->list);
 819
 820         kfree(rs);
 821 }
 822
 823 /*
 824  * For every device we have two words
 825  *  <meta_dev>: meta device name or '-' if missing
 826  *  <data_dev>: data device name or '-' if missing
 827  *
 828  * The following are permitted:
 829  *    - -
 830  *    - <data_dev>
 831  *    <meta_dev> <data_dev>
 832  *
 833  * The following is not allowed:
 834  *    <meta_dev> -
 835  *
 836  * This code parses those words.  If there is a failure,
 837  * the caller must use raid_set_free() to unwind the operations.
 838  */
 839 static int parse_dev_params(struct raid_set *rs, struct dm_arg_set *as)
 840 {
 841         int i;
 842         int rebuild = 0;
 843         int metadata_available = 0;
 844         int r = 0;
 845         const char *arg;
 846
 847         /* Put off the number of raid devices argument to get to dev pairs */
 848         arg = dm_shift_arg(as);
 849         if (!arg)
 850                 return -EINVAL;
 851
 852         for (i = 0; i < rs->raid_disks; i++) {
 853                 rs->dev[i].rdev.raid_disk = i;
 854
 855                 rs->dev[i].meta_dev = NULL;
 856                 rs->dev[i].data_dev = NULL;
 857
 858                 /*
 859                  * There are no offsets initially.
 860                  * Out of place reshape will set them accordingly.
 861                  */
 862                 rs->dev[i].rdev.data_offset = 0;
 863                 rs->dev[i].rdev.new_data_offset = 0;
 864                 rs->dev[i].rdev.mddev = &rs->md;
 865
 866                 arg = dm_shift_arg(as);
 867                 if (!arg)
 868                         return -EINVAL;
 869
 870                 if (strcmp(arg, "-")) {
 871                         r = dm_get_device(rs->ti, arg, dm_table_get_mode(rs->ti->table),
 872                                           &rs->dev[i].meta_dev);
 873                         if (r) {
 874                                 rs->ti->error = "RAID metadata device lookup failure";
 875                                 return r;
 876                         }
 877
 878                         rs->dev[i].rdev.sb_page = alloc_page(GFP_KERNEL);
 879                         if (!rs->dev[i].rdev.sb_page) {
 880                                 rs->ti->error = "Failed to allocate superblock page";
 881                                 return -ENOMEM;
 882                         }
 883                 }
 884
 885                 arg = dm_shift_arg(as);
 886                 if (!arg)
 887                         return -EINVAL;
 888
 889                 if (!strcmp(arg, "-")) {
 890                         if (!test_bit(In_sync, &rs->dev[i].rdev.flags) &&
 891                             (!rs->dev[i].rdev.recovery_offset)) {
 892                                 rs->ti->error = "Drive designated for rebuild not specified";
 893                                 return -EINVAL;
 894                         }
 895
 896                         if (rs->dev[i].meta_dev) {
 897                                 rs->ti->error = "No data device supplied with metadata device";
 898                                 return -EINVAL;
 899                         }
 900
 901                         continue;
 902                 }
 903
 904                 r = dm_get_device(rs->ti, arg, dm_table_get_mode(rs->ti->table),
 905                                   &rs->dev[i].data_dev);
 906                 if (r) {
 907                         rs->ti->error = "RAID device lookup failure";
 908                         return r;
 909                 }
 910
 911                 if (rs->dev[i].meta_dev) {
 912                         metadata_available = 1;
 913                         rs->dev[i].rdev.meta_bdev = rs->dev[i].meta_dev->bdev;
 914                 }
 915                 rs->dev[i].rdev.bdev = rs->dev[i].data_dev->bdev;
 916                 list_add_tail(&rs->dev[i].rdev.same_set, &rs->md.disks);
 917                 if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
 918                         rebuild++;
 919         }
 920
 921         if (rs->journal_dev.dev)
 922                 list_add_tail(&rs->journal_dev.rdev.same_set, &rs->md.disks);
 923
 924         if (metadata_available) {
 925                 rs->md.external = 0;
 926                 rs->md.persistent = 1;
 927                 rs->md.major_version = 2;
 928         } else if (rebuild && !rs->md.recovery_cp) {
 929                 /*
 930                  * Without metadata, we will not be able to tell if the array
 931                  * is in-sync or not - we must assume it is not.  Therefore,
 932                  * it is impossible to rebuild a drive.
 933                  *
 934                  * Even if there is metadata, the on-disk information may
 935                  * indicate that the array is not in-sync and it will then
 936                  * fail at that time.
 937                  *
 938                  * User could specify 'nosync' option if desperate.
 939                  */
 940                 rs->ti->error = "Unable to rebuild drive while array is not in-sync";
 941                 return -EINVAL;
 942         }
 943
 944         return 0;
 945 }
 946
 947 /*
 948  * validate_region_size
 949  * @rs
 950  * @region_size:  region size in sectors.  If 0, pick a size (4MiB default).
 951  *
 952  * Set rs->md.bitmap_info.chunksize (which really refers to 'region size').
 953  * Ensure that (ti->len/region_size < 2^21) - required by MD bitmap.
 954  *
 955  * Returns: 0 on success, -EINVAL on failure.
 956  */
 957 static int validate_region_size(struct raid_set *rs, unsigned long region_size)
 958 {
 959         unsigned long min_region_size = rs->ti->len / (1 << 21);
 960
 961         if (rs_is_raid0(rs))
 962                 return 0;
 963
 964         if (!region_size) {
 965                 /*
 966                  * Choose a reasonable default.  All figures in sectors.
 967                  */
 968                 if (min_region_size > (1 << 13)) {
 969                         /* If not a power of 2, make it the next power of 2 */
 970                         region_size = roundup_pow_of_two(min_region_size);
 971                         DMINFO("Choosing default region size of %lu sectors",
 972                                region_size);
 973                 } else {
 974                         DMINFO("Choosing default region size of 4MiB");
 975                         region_size = 1 << 13; /* sectors */
 976                 }
 977         } else {
 978                 /*
 979                  * Validate user-supplied value.
 980                  */
 981                 if (region_size > rs->ti->len) {
 982                         rs->ti->error = "Supplied region size is too large";
 983                         return -EINVAL;
 984                 }
 985
 986                 if (region_size < min_region_size) {
 987                         DMERR("Supplied region_size (%lu sectors) below minimum (%lu)",
 988                               region_size, min_region_size);
 989                         rs->ti->error = "Supplied region size is too small";
 990                         return -EINVAL;
 991                 }
 992
 993                 if (!is_power_of_2(region_size)) {
 994                         rs->ti->error = "Region size is not a power of 2";
 995                         return -EINVAL;
 996                 }
 997
 998                 if (region_size < rs->md.chunk_sectors) {
 999                         rs->ti->error = "Region size is smaller than the chunk size";
1000                         return -EINVAL;
1001                 }
1002         }
1003
1004         /*
1005          * Convert sectors to bytes.
1006          */
1007         rs->md.bitmap_info.chunksize = to_bytes(region_size);
1008
1009         return 0;
1010 }
1011
1012 /*
1013  * validate_raid_redundancy
1014  * @rs
1015  *
1016  * Determine if there are enough devices in the array that haven't
1017  * failed (or are being rebuilt) to form a usable array.
1018  *
1019  * Returns: 0 on success, -EINVAL on failure.
1020  */
1021 static int validate_raid_redundancy(struct raid_set *rs)
1022 {
1023         unsigned int i, rebuild_cnt = 0;
1024         unsigned int rebuilds_per_group = 0, copies;
1025         unsigned int group_size, last_group_start;
1026
1027         for (i = 0; i < rs->md.raid_disks; i++)
1028                 if (!test_bit(In_sync, &rs->dev[i].rdev.flags) ||
1029                     !rs->dev[i].rdev.sb_page)
1030                         rebuild_cnt++;
1031
1032         switch (rs->md.level) {
1033         case 0:
1034                 break;
1035         case 1:
1036                 if (rebuild_cnt >= rs->md.raid_disks)
1037                         goto too_many;
1038                 break;
1039         case 4:
1040         case 5:
1041         case 6:
1042                 if (rebuild_cnt > rs->raid_type->parity_devs)
1043                         goto too_many;
1044                 break;
1045         case 10:
1046                 copies = raid10_md_layout_to_copies(rs->md.new_layout);
1047                 if (copies < 2) {
1048                         DMERR("Bogus raid10 data copies < 2!");
1049                         return -EINVAL;
1050                 }
1051
1052                 if (rebuild_cnt < copies)
1053                         break;
1054
1055                 /*
1056                  * It is possible to have a higher rebuild count for RAID10,
1057                  * as long as the failed devices occur in different mirror
1058                  * groups (i.e. different stripes).
1059                  *
1060                  * When checking "near" format, make sure no adjacent devices
1061                  * have failed beyond what can be handled.  In addition to the
1062                  * simple case where the number of devices is a multiple of the
1063                  * number of copies, we must also handle cases where the number
1064                  * of devices is not a multiple of the number of copies.
1065                  * E.g.    dev1 dev2 dev3 dev4 dev5
1066                  *          A    A    B    B    C
1067                  *          C    D    D    E    E
1068                  */
1069                 if (__is_raid10_near(rs->md.new_layout)) {
1070                         for (i = 0; i < rs->md.raid_disks; i++) {
1071                                 if (!(i % copies))
1072                                         rebuilds_per_group = 0;
1073                                 if ((!rs->dev[i].rdev.sb_page ||
1074                                     !test_bit(In_sync, &rs->dev[i].rdev.flags)) &&
1075                                     (++rebuilds_per_group >= copies))
1076                                         goto too_many;
1077                         }
1078                         break;
1079                 }
1080
1081                 /*
1082                  * When checking "far" and "offset" formats, we need to ensure
1083                  * that the device that holds its copy is not also dead or
1084                  * being rebuilt.  (Note that "far" and "offset" formats only
1085                  * support two copies right now.  These formats also only ever
1086                  * use the 'use_far_sets' variant.)
1087                  *
1088                  * This check is somewhat complicated by the need to account
1089                  * for arrays that are not a multiple of (far) copies.  This
1090                  * results in the need to treat the last (potentially larger)
1091                  * set differently.
1092                  */
1093                 group_size = (rs->md.raid_disks / copies);
1094                 last_group_start = (rs->md.raid_disks / group_size) - 1;
1095                 last_group_start *= group_size;
1096                 for (i = 0; i < rs->md.raid_disks; i++) {
1097                         if (!(i % copies) && !(i > last_group_start))
1098                                 rebuilds_per_group = 0;
1099                         if ((!rs->dev[i].rdev.sb_page ||
1100                              !test_bit(In_sync, &rs->dev[i].rdev.flags)) &&
1101                             (++rebuilds_per_group >= copies))
1102                                         goto too_many;
1103                 }
1104                 break;
1105         default:
1106                 if (rebuild_cnt)
1107                         return -EINVAL;
1108         }
1109
1110         return 0;
1111
1112 too_many:
1113         return -EINVAL;
1114 }
1115
1116 /*
1117  * Possible arguments are...
1118  *      <chunk_size> [optional_args]
1119  *
1120  * Argument definitions
1121  *    <chunk_size>                      The number of sectors per disk that
1122  *                                      will form the "stripe"
1123  *    [[no]sync]                        Force or prevent recovery of the
1124  *                                      entire array
1125  *    [rebuild <idx>]                   Rebuild the drive indicated by the index
1126  *    [daemon_sleep <ms>]               Time between bitmap daemon work to
1127  *                                      clear bits
1128  *    [min_recovery_rate <kB/sec/disk>] Throttle RAID initialization
1129  *    [max_recovery_rate <kB/sec/disk>] Throttle RAID initialization
1130  *    [write_mostly <idx>]              Indicate a write mostly drive via index
1131  *    [max_write_behind <sectors>]      See '-write-behind=' (man mdadm)
1132  *    [stripe_cache <sectors>]          Stripe cache size for higher RAIDs
1133  *    [region_size <sectors>]           Defines granularity of bitmap
1134  *    [journal_dev <dev>]               raid4/5/6 journaling deviice
1135  *                                      (i.e. write hole closing log)
1136  *
1137  * RAID10-only options:
1138  *    [raid10_copies <# copies>]        Number of copies.  (Default: 2)
1139  *    [raid10_format <near|far|offset>] Layout algorithm.  (Default: near)
1140  */
1141 static int parse_raid_params(struct raid_set *rs, struct dm_arg_set *as,
1142                              unsigned int num_raid_params)
1143 {
1144         int value, raid10_format = ALGORITHM_RAID10_DEFAULT;
1145         unsigned int raid10_copies = 2;
1146         unsigned int i, write_mostly = 0;
1147         unsigned int region_size = 0;
1148         sector_t max_io_len;
1149         const char *arg, *key;
1150         struct raid_dev *rd;
1151         struct raid_type *rt = rs->raid_type;
1152
1153         arg = dm_shift_arg(as);
1154         num_raid_params--; /* Account for chunk_size argument */
1155
1156         if (kstrtoint(arg, 10, &value) < 0) {
1157                 rs->ti->error = "Bad numerical argument given for chunk_size";
1158                 return -EINVAL;
1159         }
1160
1161         /*
1162          * First, parse the in-order required arguments
1163          * "chunk_size" is the only argument of this type.
1164          */
1165         if (rt_is_raid1(rt)) {
1166                 if (value)
1167                         DMERR("Ignoring chunk size parameter for RAID 1");
1168                 value = 0;
1169         } else if (!is_power_of_2(value)) {
1170                 rs->ti->error = "Chunk size must be a power of 2";
1171                 return -EINVAL;
1172         } else if (value < 8) {
1173                 rs->ti->error = "Chunk size value is too small";
1174                 return -EINVAL;
1175         }
1176
1177         rs->md.new_chunk_sectors = rs->md.chunk_sectors = value;
1178
1179         /*
1180          * We set each individual device as In_sync with a completed
1181          * 'recovery_offset'.  If there has been a device failure or
1182          * replacement then one of the following cases applies:
1183          *
1184          *   1) User specifies 'rebuild'.
1185          *      - Device is reset when param is read.
1186          *   2) A new device is supplied.
1187          *      - No matching superblock found, resets device.
1188          *   3) Device failure was transient and returns on reload.
1189          *      - Failure noticed, resets device for bitmap replay.
1190          *   4) Device hadn't completed recovery after previous failure.
1191          *      - Superblock is read and overrides recovery_offset.
1192          *
1193          * What is found in the superblocks of the devices is always
1194          * authoritative, unless 'rebuild' or '[no]sync' was specified.
1195          */
1196         for (i = 0; i < rs->raid_disks; i++) {
1197                 set_bit(In_sync, &rs->dev[i].rdev.flags);
1198                 rs->dev[i].rdev.recovery_offset = MaxSector;
1199         }
1200
1201         /*
1202          * Second, parse the unordered optional arguments
1203          */
1204         for (i = 0; i < num_raid_params; i++) {
1205                 key = dm_shift_arg(as);
1206                 if (!key) {
1207                         rs->ti->error = "Not enough raid parameters given";
1208                         return -EINVAL;
1209                 }
1210
1211                 if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_NOSYNC))) {
1212                         if (test_and_set_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
1213                                 rs->ti->error = "Only one 'nosync' argument allowed";
1214                                 return -EINVAL;
1215                         }
1216                         continue;
1217                 }
1218                 if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_SYNC))) {
1219                         if (test_and_set_bit(__CTR_FLAG_SYNC, &rs->ctr_flags)) {
1220                                 rs->ti->error = "Only one 'sync' argument allowed";
1221                                 return -EINVAL;
1222                         }
1223                         continue;
1224                 }
1225                 if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_USE_NEAR_SETS))) {
1226                         if (test_and_set_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags)) {
1227                                 rs->ti->error = "Only one 'raid10_use_new_sets' argument allowed";
1228                                 return -EINVAL;
1229                         }
1230                         continue;
1231                 }
1232
1233                 arg = dm_shift_arg(as);
1234                 i++; /* Account for the argument pairs */
1235                 if (!arg) {
1236                         rs->ti->error = "Wrong number of raid parameters given";
1237                         return -EINVAL;
1238                 }
1239
1240                 /*
1241                  * Parameters that take a string value are checked here.
1242                  */
1243                 /* "raid10_format {near|offset|far} */
1244                 if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_FORMAT))) {
1245                         if (test_and_set_bit(__CTR_FLAG_RAID10_FORMAT, &rs->ctr_flags)) {
1246                                 rs->ti->error = "Only one 'raid10_format' argument pair allowed";
1247                                 return -EINVAL;
1248                         }
1249                         if (!rt_is_raid10(rt)) {
1250                                 rs->ti->error = "'raid10_format' is an invalid parameter for this RAID type";
1251                                 return -EINVAL;
1252                         }
1253                         raid10_format = raid10_name_to_format(arg);
1254                         if (raid10_format < 0) {
1255                                 rs->ti->error = "Invalid 'raid10_format' value given";
1256                                 return raid10_format;
1257                         }
1258                         continue;
1259                 }
1260
1261                 /* "journal_dev <dev>" */
1262                 if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_DEV))) {
1263                         int r;
1264                         struct md_rdev *jdev;
1265
1266                         if (test_and_set_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
1267                                 rs->ti->error = "Only one raid4/5/6 set journaling device allowed";
1268                                 return -EINVAL;
1269                         }
1270                         if (!rt_is_raid456(rt)) {
1271                                 rs->ti->error = "'journal_dev' is an invalid parameter for this RAID type";
1272                                 return -EINVAL;
1273                         }
1274                         r = dm_get_device(rs->ti, arg, dm_table_get_mode(rs->ti->table),
1275                                           &rs->journal_dev.dev);
1276                         if (r) {
1277                                 rs->ti->error = "raid4/5/6 journal device lookup failure";
1278                                 return r;
1279                         }
1280                         jdev = &rs->journal_dev.rdev;
1281                         md_rdev_init(jdev);
1282                         jdev->mddev = &rs->md;
1283                         jdev->bdev = rs->journal_dev.dev->bdev;
1284                         jdev->sectors = to_sector(i_size_read(jdev->bdev->bd_inode));
1285                         if (jdev->sectors < MIN_RAID456_JOURNAL_SPACE) {
1286                                 rs->ti->error = "No space for raid4/5/6 journal";
1287                                 return -ENOSPC;
1288                         }
1289                         rs->journal_dev.mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
1290                         set_bit(Journal, &jdev->flags);
1291                         continue;
1292                 }
1293
1294                 /* "journal_mode <mode>" ("journal_dev" mandatory!) */
1295                 if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_MODE))) {
1296                         int r;
1297
1298                         if (!test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
1299                                 rs->ti->error = "raid4/5/6 'journal_mode' is invalid without 'journal_dev'";
1300                                 return -EINVAL;
1301                         }
1302                         if (test_and_set_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags)) {
1303                                 rs->ti->error = "Only one raid4/5/6 'journal_mode' argument allowed";
1304                                 return -EINVAL;
1305                         }
1306                         r = dm_raid_journal_mode_to_md(arg);
1307                         if (r < 0) {
1308                                 rs->ti->error = "Invalid 'journal_mode' argument";
1309                                 return r;
1310                         }
1311                         rs->journal_dev.mode = r;
1312                         continue;
1313                 }
1314
1315                 /*
1316                  * Parameters with number values from here on.
1317                  */
1318                 if (kstrtoint(arg, 10, &value) < 0) {
1319                         rs->ti->error = "Bad numerical argument given in raid params";
1320                         return -EINVAL;
1321                 }
1322
1323                 if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_REBUILD))) {
1324                         /*
1325                          * "rebuild" is being passed in by userspace to provide
1326                          * indexes of replaced devices and to set up additional
1327                          * devices on raid level takeover.
1328                          */
1329                         if (!__within_range(value, 0, rs->raid_disks - 1)) {
1330                                 rs->ti->error = "Invalid rebuild index given";
1331                                 return -EINVAL;
1332                         }
1333
1334                         if (test_and_set_bit(value, (void *) rs->rebuild_disks)) {
1335                                 rs->ti->error = "rebuild for this index already given";
1336                                 return -EINVAL;
1337                         }
1338
1339                         rd = rs->dev + value;
1340                         clear_bit(In_sync, &rd->rdev.flags);
1341                         clear_bit(Faulty, &rd->rdev.flags);
1342                         rd->rdev.recovery_offset = 0;
1343                         set_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags);
1344                 } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_WRITE_MOSTLY))) {
1345                         if (!rt_is_raid1(rt)) {
1346                                 rs->ti->error = "write_mostly option is only valid for RAID1";
1347                                 return -EINVAL;
1348                         }
1349
1350                         if (!__within_range(value, 0, rs->md.raid_disks - 1)) {
1351                                 rs->ti->error = "Invalid write_mostly index given";
1352                                 return -EINVAL;
1353                         }
1354
1355                         write_mostly++;
1356                         set_bit(WriteMostly, &rs->dev[value].rdev.flags);
1357                         set_bit(__CTR_FLAG_WRITE_MOSTLY, &rs->ctr_flags);
1358                 } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_MAX_WRITE_BEHIND))) {
1359                         if (!rt_is_raid1(rt)) {
1360                                 rs->ti->error = "max_write_behind option is only valid for RAID1";
1361                                 return -EINVAL;
1362                         }
1363
1364                         if (test_and_set_bit(__CTR_FLAG_MAX_WRITE_BEHIND, &rs->ctr_flags)) {
1365                                 rs->ti->error = "Only one max_write_behind argument pair allowed";
1366                                 return -EINVAL;
1367                         }
1368
1369                         /*
1370                          * In device-mapper, we specify things in sectors, but
1371                          * MD records this value in kB
1372                          */
1373                         value /= 2;
1374                         if (value > COUNTER_MAX) {
1375                                 rs->ti->error = "Max write-behind limit out of range";
1376                                 return -EINVAL;
1377                         }
1378
1379                         rs->md.bitmap_info.max_write_behind = value;
1380                 } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_DAEMON_SLEEP))) {
1381                         if (test_and_set_bit(__CTR_FLAG_DAEMON_SLEEP, &rs->ctr_flags)) {
1382                                 rs->ti->error = "Only one daemon_sleep argument pair allowed";
1383                                 return -EINVAL;
1384                         }
1385                         if (!value || (value > MAX_SCHEDULE_TIMEOUT)) {
1386                                 rs->ti->error = "daemon sleep period out of range";
1387                                 return -EINVAL;
1388                         }
1389                         rs->md.bitmap_info.daemon_sleep = value;
1390                 } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_DATA_OFFSET))) {
1391                         /* Userspace passes new data_offset after having extended the the data image LV */
1392                         if (test_and_set_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags)) {
1393                                 rs->ti->error = "Only one data_offset argument pair allowed";
1394                                 return -EINVAL;
1395                         }
1396                         /* Ensure sensible data offset */
1397                         if (value < 0 ||
1398                             (value && (value < MIN_FREE_RESHAPE_SPACE || value % to_sector(PAGE_SIZE)))) {
1399                                 rs->ti->error = "Bogus data_offset value";
1400                                 return -EINVAL;
1401                         }
1402                         rs->data_offset = value;
1403                 } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_DELTA_DISKS))) {
1404                         /* Define the +/-# of disks to add to/remove from the given raid set */
1405                         if (test_and_set_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags)) {
1406                                 rs->ti->error = "Only one delta_disks argument pair allowed";
1407                                 return -EINVAL;
1408                         }
1409                         /* Ensure MAX_RAID_DEVICES and raid type minimal_devs! */
1410                         if (!__within_range(abs(value), 1, MAX_RAID_DEVICES - rt->minimal_devs)) {
1411                                 rs->ti->error = "Too many delta_disk requested";
1412                                 return -EINVAL;
1413                         }
1414
1415                         rs->delta_disks = value;
1416                 } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_STRIPE_CACHE))) {
1417                         if (test_and_set_bit(__CTR_FLAG_STRIPE_CACHE, &rs->ctr_flags)) {
1418                                 rs->ti->error = "Only one stripe_cache argument pair allowed";
1419                                 return -EINVAL;
1420                         }
1421
1422                         if (!rt_is_raid456(rt)) {
1423                                 rs->ti->error = "Inappropriate argument: stripe_cache";
1424                                 return -EINVAL;
1425                         }
1426
1427                         rs->stripe_cache_entries = value;
1428                 } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_MIN_RECOVERY_RATE))) {
1429                         if (test_and_set_bit(__CTR_FLAG_MIN_RECOVERY_RATE, &rs->ctr_flags)) {
1430                                 rs->ti->error = "Only one min_recovery_rate argument pair allowed";
1431                                 return -EINVAL;
1432                         }
1433                         if (value > INT_MAX) {
1434                                 rs->ti->error = "min_recovery_rate out of range";
1435                                 return -EINVAL;
1436                         }
1437                         rs->md.sync_speed_min = (int)value;
1438                 } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_MAX_RECOVERY_RATE))) {
1439                         if (test_and_set_bit(__CTR_FLAG_MAX_RECOVERY_RATE, &rs->ctr_flags)) {
1440                                 rs->ti->error = "Only one max_recovery_rate argument pair allowed";
1441                                 return -EINVAL;
1442                         }
1443                         if (value > INT_MAX) {
1444                                 rs->ti->error = "max_recovery_rate out of range";
1445                                 return -EINVAL;
1446                         }
1447                         rs->md.sync_speed_max = (int)value;
1448                 } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_REGION_SIZE))) {
1449                         if (test_and_set_bit(__CTR_FLAG_REGION_SIZE, &rs->ctr_flags)) {
1450                                 rs->ti->error = "Only one region_size argument pair allowed";
1451                                 return -EINVAL;
1452                         }
1453
1454                         region_size = value;
1455                         rs->requested_bitmap_chunk_sectors = value;
1456                 } else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_COPIES))) {
1457                         if (test_and_set_bit(__CTR_FLAG_RAID10_COPIES, &rs->ctr_flags)) {
1458                                 rs->ti->error = "Only one raid10_copies argument pair allowed";
1459                                 return -EINVAL;
1460                         }
1461
1462                         if (!__within_range(value, 2, rs->md.raid_disks)) {
1463                                 rs->ti->error = "Bad value for 'raid10_copies'";
1464                                 return -EINVAL;
1465                         }
1466
1467                         raid10_copies = value;
1468                 } else {
1469                         DMERR("Unable to parse RAID parameter: %s", key);
1470                         rs->ti->error = "Unable to parse RAID parameter";
1471                         return -EINVAL;
1472                 }
1473         }
1474
1475         if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags) &&
1476             test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
1477                 rs->ti->error = "sync and nosync are mutually exclusive";
1478                 return -EINVAL;
1479         }
1480
1481         if (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags) &&
1482             (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags) ||
1483              test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))) {
1484                 rs->ti->error = "sync/nosync and rebuild are mutually exclusive";
1485                 return -EINVAL;
1486         }
1487
1488         if (write_mostly >= rs->md.raid_disks) {
1489                 rs->ti->error = "Can't set all raid1 devices to write_mostly";
1490                 return -EINVAL;
1491         }
1492
1493         if (validate_region_size(rs, region_size))
1494                 return -EINVAL;
1495
1496         if (rs->md.chunk_sectors)
1497                 max_io_len = rs->md.chunk_sectors;
1498         else
1499                 max_io_len = region_size;
1500
1501         if (dm_set_target_max_io_len(rs->ti, max_io_len))
1502                 return -EINVAL;
1503
1504         if (rt_is_raid10(rt)) {
1505                 if (raid10_copies > rs->md.raid_disks) {
1506                         rs->ti->error = "Not enough devices to satisfy specification";
1507                         return -EINVAL;
1508                 }
1509
1510                 rs->md.new_layout = raid10_format_to_md_layout(rs, raid10_format, raid10_copies);
1511                 if (rs->md.new_layout < 0) {
1512                         rs->ti->error = "Error getting raid10 format";
1513                         return rs->md.new_layout;
1514                 }
1515
1516                 rt = get_raid_type_by_ll(10, rs->md.new_layout);
1517                 if (!rt) {
1518                         rs->ti->error = "Failed to recognize new raid10 layout";
1519                         return -EINVAL;
1520                 }
1521
1522                 if ((rt->algorithm == ALGORITHM_RAID10_DEFAULT ||
1523                      rt->algorithm == ALGORITHM_RAID10_NEAR) &&
1524                     test_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags)) {
1525                         rs->ti->error = "RAID10 format 'near' and 'raid10_use_near_sets' are incompatible";
1526                         return -EINVAL;
1527                 }
1528         }
1529
1530         rs->raid10_copies = raid10_copies;
1531
1532         /* Assume there are no metadata devices until the drives are parsed */
1533         rs->md.persistent = 0;
1534         rs->md.external = 1;
1535
1536         /* Check, if any invalid ctr arguments have been passed in for the raid level */
1537         return rs_check_for_valid_flags(rs);
1538 }
1539
1540 /* Set raid4/5/6 cache size */
1541 static int rs_set_raid456_stripe_cache(struct raid_set *rs)
1542 {
1543         int r;
1544         struct r5conf *conf;
1545         struct mddev *mddev = &rs->md;
1546         uint32_t min_stripes = max(mddev->chunk_sectors, mddev->new_chunk_sectors) / 2;
1547         uint32_t nr_stripes = rs->stripe_cache_entries;
1548
1549         if (!rt_is_raid456(rs->raid_type)) {
1550                 rs->ti->error = "Inappropriate raid level; cannot change stripe_cache size";
1551                 return -EINVAL;
1552         }
1553
1554         if (nr_stripes < min_stripes) {
1555                 DMINFO("Adjusting requested %u stripe cache entries to %u to suit stripe size",
1556                        nr_stripes, min_stripes);
1557                 nr_stripes = min_stripes;
1558         }
1559
1560         conf = mddev->private;
1561         if (!conf) {
1562                 rs->ti->error = "Cannot change stripe_cache size on inactive RAID set";
1563                 return -EINVAL;
1564         }
1565
1566         /* Try setting number of stripes in raid456 stripe cache */
1567         if (conf->min_nr_stripes != nr_stripes) {
1568                 r = raid5_set_cache_size(mddev, nr_stripes);
1569                 if (r) {
1570                         rs->ti->error = "Failed to set raid4/5/6 stripe cache size";
1571                         return r;
1572                 }
1573
1574                 DMINFO("%u stripe cache entries", nr_stripes);
1575         }
1576
1577         return 0;
1578 }
1579
1580 /* Return # of data stripes as kept in mddev as of @rs (i.e. as of superblock) */
1581 static unsigned int mddev_data_stripes(struct raid_set *rs)
1582 {
1583         return rs->md.raid_disks - rs->raid_type->parity_devs;
1584 }
1585
1586 /* Return # of data stripes of @rs (i.e. as of ctr) */
1587 static unsigned int rs_data_stripes(struct raid_set *rs)
1588 {
1589         return rs->raid_disks - rs->raid_type->parity_devs;
1590 }
1591
1592 /*
1593  * Retrieve rdev->sectors from any valid raid device of @rs
1594  * to allow userpace to pass in arbitray "- -" device tupples.
1595  */
1596 static sector_t __rdev_sectors(struct raid_set *rs)
1597 {
1598         int i;
1599
1600         for (i = 0; i < rs->md.raid_disks; i++) {
1601                 struct md_rdev *rdev = &rs->dev[i].rdev;
1602
1603                 if (!test_bit(Journal, &rdev->flags) &&
1604                     rdev->bdev && rdev->sectors)
1605                         return rdev->sectors;
1606         }
1607
1608         return 0;
1609 }
1610
1611 /* Check that calculated dev_sectors fits all component devices. */
1612 static int _check_data_dev_sectors(struct raid_set *rs)
1613 {
1614         sector_t ds = ~0;
1615         struct md_rdev *rdev;
1616
1617         rdev_for_each(rdev, &rs->md)
1618                 if (!test_bit(Journal, &rdev->flags) && rdev->bdev) {
1619                         ds = min(ds, to_sector(i_size_read(rdev->bdev->bd_inode)));
1620                         if (ds < rs->md.dev_sectors) {
1621                                 rs->ti->error = "Component device(s) too small";
1622                                 return -EINVAL;
1623                         }
1624                 }
1625
1626         return 0;
1627 }
1628
1629 /* Calculate the sectors per device and per array used for @rs */
1630 static int rs_set_dev_and_array_sectors(struct raid_set *rs, bool use_mddev)
1631 {
1632         int delta_disks;
1633         unsigned int data_stripes;
1634         struct mddev *mddev = &rs->md;
1635         struct md_rdev *rdev;
1636         sector_t array_sectors = rs->ti->len, dev_sectors = rs->ti->len;
1637
1638         if (use_mddev) {
1639                 delta_disks = mddev->delta_disks;
1640                 data_stripes = mddev_data_stripes(rs);
1641         } else {
1642                 delta_disks = rs->delta_disks;
1643                 data_stripes = rs_data_stripes(rs);
1644         }
1645
1646         /* Special raid1 case w/o delta_disks support (yet) */
1647         if (rt_is_raid1(rs->raid_type))
1648                 ;
1649         else if (rt_is_raid10(rs->raid_type)) {
1650                 if (rs->raid10_copies < 2 ||
1651                     delta_disks < 0) {
1652                         rs->ti->error = "Bogus raid10 data copies or delta disks";
1653                         return -EINVAL;
1654                 }
1655
1656                 dev_sectors *= rs->raid10_copies;
1657                 if (sector_div(dev_sectors, data_stripes))
1658                         goto bad;
1659
1660                 array_sectors = (data_stripes + delta_disks) * dev_sectors;
1661                 if (sector_div(array_sectors, rs->raid10_copies))
1662                         goto bad;
1663
1664         } else if (sector_div(dev_sectors, data_stripes))
1665                 goto bad;
1666
1667         else
1668                 /* Striped layouts */
1669                 array_sectors = (data_stripes + delta_disks) * dev_sectors;
1670
1671         rdev_for_each(rdev, mddev)
1672                 if (!test_bit(Journal, &rdev->flags))
1673                         rdev->sectors = dev_sectors;
1674
1675         mddev->array_sectors = array_sectors;
1676         mddev->dev_sectors = dev_sectors;
1677
1678         return _check_data_dev_sectors(rs);
1679 bad:
1680         rs->ti->error = "Target length not divisible by number of data devices";
1681         return -EINVAL;
1682 }
1683
1684 /* Setup recovery on @rs */
1685 static void __rs_setup_recovery(struct raid_set *rs, sector_t dev_sectors)
1686 {
1687         /* raid0 does not recover */
1688         if (rs_is_raid0(rs))
1689                 rs->md.recovery_cp = MaxSector;
1690         /*
1691          * A raid6 set has to be recovered either
1692          * completely or for the grown part to
1693          * ensure proper parity and Q-Syndrome
1694          */
1695         else if (rs_is_raid6(rs))
1696                 rs->md.recovery_cp = dev_sectors;
1697         /*
1698          * Other raid set types may skip recovery
1699          * depending on the 'nosync' flag.
1700          */
1701         else
1702                 rs->md.recovery_cp = test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)
1703                                      ? MaxSector : dev_sectors;
1704 }
1705
1706 /* Setup recovery on @rs based on raid type, device size and 'nosync' flag */
1707 static void rs_setup_recovery(struct raid_set *rs, sector_t dev_sectors)
1708 {
1709         if (!dev_sectors)
1710                 /* New raid set or 'sync' flag provided */
1711                 __rs_setup_recovery(rs, 0);
1712         else if (dev_sectors == MaxSector)
1713                 /* Prevent recovery */
1714                 __rs_setup_recovery(rs, MaxSector);
1715         else if (__rdev_sectors(rs) < dev_sectors)
1716                 /* Grown raid set */
1717                 __rs_setup_recovery(rs, __rdev_sectors(rs));
1718         else
1719                 __rs_setup_recovery(rs, MaxSector);
1720 }
1721
1722 static void do_table_event(struct work_struct *ws)
1723 {
1724         struct raid_set *rs = container_of(ws, struct raid_set, md.event_work);
1725
1726         smp_rmb(); /* Make sure we access most actual mddev properties */
1727         if (!rs_is_reshaping(rs)) {
1728                 if (rs_is_raid10(rs))
1729                         rs_set_rdev_sectors(rs);
1730                 rs_set_capacity(rs);
1731         }
1732         dm_table_event(rs->ti->table);
1733 }
1734
1735 static int raid_is_congested(struct dm_target_callbacks *cb, int bits)
1736 {
1737         struct raid_set *rs = container_of(cb, struct raid_set, callbacks);
1738
1739         return mddev_congested(&rs->md, bits);
1740 }
1741
1742 /*
1743  * Make sure a valid takover (level switch) is being requested on @rs
1744  *
1745  * Conversions of raid sets from one MD personality to another
1746  * have to conform to restrictions which are enforced here.
1747  */
1748 static int rs_check_takeover(struct raid_set *rs)
1749 {
1750         struct mddev *mddev = &rs->md;
1751         unsigned int near_copies;
1752
1753         if (rs->md.degraded) {
1754                 rs->ti->error = "Can't takeover degraded raid set";
1755                 return -EPERM;
1756         }
1757
1758         if (rs_is_reshaping(rs)) {
1759                 rs->ti->error = "Can't takeover reshaping raid set";
1760                 return -EPERM;
1761         }
1762
1763         switch (mddev->level) {
1764         case 0:
1765                 /* raid0 -> raid1/5 with one disk */
1766                 if ((mddev->new_level == 1 || mddev->new_level == 5) &&
1767                     mddev->raid_disks == 1)
1768                         return 0;
1769
1770                 /* raid0 -> raid10 */
1771                 if (mddev->new_level == 10 &&
1772                     !(rs->raid_disks % mddev->raid_disks))
1773                         return 0;
1774
1775                 /* raid0 with multiple disks -> raid4/5/6 */
1776                 if (__within_range(mddev->new_level, 4, 6) &&
1777                     mddev->new_layout == ALGORITHM_PARITY_N &&
1778                     mddev->raid_disks > 1)
1779                         return 0;
1780
1781                 break;
1782
1783         case 10:
1784                 /* Can't takeover raid10_offset! */
1785                 if (__is_raid10_offset(mddev->layout))
1786                         break;
1787
1788                 near_copies = __raid10_near_copies(mddev->layout);
1789
1790                 /* raid10* -> raid0 */
1791                 if (mddev->new_level == 0) {
1792                         /* Can takeover raid10_near with raid disks divisable by data copies! */
1793                         if (near_copies > 1 &&
1794                             !(mddev->raid_disks % near_copies)) {
1795                                 mddev->raid_disks /= near_copies;
1796                                 mddev->delta_disks = mddev->raid_disks;
1797                                 return 0;
1798                         }
1799
1800                         /* Can takeover raid10_far */
1801                         if (near_copies == 1 &&
1802                             __raid10_far_copies(mddev->layout) > 1)
1803                                 return 0;
1804
1805                         break;
1806                 }
1807
1808                 /* raid10_{near,far} -> raid1 */
1809                 if (mddev->new_level == 1 &&
1810                     max(near_copies, __raid10_far_copies(mddev->layout)) == mddev->raid_disks)
1811                         return 0;
1812
1813                 /* raid10_{near,far} with 2 disks -> raid4/5 */
1814                 if (__within_range(mddev->new_level, 4, 5) &&
1815                     mddev->raid_disks == 2)
1816                         return 0;
1817                 break;
1818
1819         case 1:
1820                 /* raid1 with 2 disks -> raid4/5 */
1821                 if (__within_range(mddev->new_level, 4, 5) &&
1822                     mddev->raid_disks == 2) {
1823                         mddev->degraded = 1;
1824                         return 0;
1825                 }
1826
1827                 /* raid1 -> raid0 */
1828                 if (mddev->new_level == 0 &&
1829                     mddev->raid_disks == 1)
1830                         return 0;
1831
1832                 /* raid1 -> raid10 */
1833                 if (mddev->new_level == 10)
1834                         return 0;
1835                 break;
1836
1837         case 4:
1838                 /* raid4 -> raid0 */
1839                 if (mddev->new_level == 0)
1840                         return 0;
1841
1842                 /* raid4 -> raid1/5 with 2 disks */
1843                 if ((mddev->new_level == 1 || mddev->new_level == 5) &&
1844                     mddev->raid_disks == 2)
1845                         return 0;
1846
1847                 /* raid4 -> raid5/6 with parity N */
1848                 if (__within_range(mddev->new_level, 5, 6) &&
1849                     mddev->layout == ALGORITHM_PARITY_N)
1850                         return 0;
1851                 break;
1852
1853         case 5:
1854                 /* raid5 with parity N -> raid0 */
1855                 if (mddev->new_level == 0 &&
1856                     mddev->layout == ALGORITHM_PARITY_N)
1857                         return 0;
1858
1859                 /* raid5 with parity N -> raid4 */
1860                 if (mddev->new_level == 4 &&
1861                     mddev->layout == ALGORITHM_PARITY_N)
1862                         return 0;
1863
1864                 /* raid5 with 2 disks -> raid1/4/10 */
1865                 if ((mddev->new_level == 1 || mddev->new_level == 4 || mddev->new_level == 10) &&
1866                     mddev->raid_disks == 2)
1867                         return 0;
1868
1869                 /* raid5_* ->  raid6_*_6 with Q-Syndrome N (e.g. raid5_ra -> raid6_ra_6 */
1870                 if (mddev->new_level == 6 &&
1871                     ((mddev->layout == ALGORITHM_PARITY_N && mddev->new_layout == ALGORITHM_PARITY_N) ||
1872                       __within_range(mddev->new_layout, ALGORITHM_LEFT_ASYMMETRIC_6, ALGORITHM_RIGHT_SYMMETRIC_6)))
1873                         return 0;
1874                 break;
1875
1876         case 6:
1877                 /* raid6 with parity N -> raid0 */
1878                 if (mddev->new_level == 0 &&
1879                     mddev->layout == ALGORITHM_PARITY_N)
1880                         return 0;
1881
1882                 /* raid6 with parity N -> raid4 */
1883                 if (mddev->new_level == 4 &&
1884                     mddev->layout == ALGORITHM_PARITY_N)
1885                         return 0;
1886
1887                 /* raid6_*_n with Q-Syndrome N -> raid5_* */
1888                 if (mddev->new_level == 5 &&
1889                     ((mddev->layout == ALGORITHM_PARITY_N && mddev->new_layout == ALGORITHM_PARITY_N) ||
1890                      __within_range(mddev->new_layout, ALGORITHM_LEFT_ASYMMETRIC, ALGORITHM_RIGHT_SYMMETRIC)))
1891                         return 0;
1892
1893         default:
1894                 break;
1895         }
1896
1897         rs->ti->error = "takeover not possible";
1898         return -EINVAL;
1899 }
1900
1901 /* True if @rs requested to be taken over */
1902 static bool rs_takeover_requested(struct raid_set *rs)
1903 {
1904         return rs->md.new_level != rs->md.level;
1905 }
1906
1907 /* True if @rs is requested to reshape by ctr */
1908 static bool rs_reshape_requested(struct raid_set *rs)
1909 {
1910         bool change;
1911         struct mddev *mddev = &rs->md;
1912
1913         if (rs_takeover_requested(rs))
1914                 return false;
1915
1916         if (rs_is_raid0(rs))
1917                 return false;
1918
1919         change = mddev->new_layout != mddev->layout ||
1920                  mddev->new_chunk_sectors != mddev->chunk_sectors ||
1921                  rs->delta_disks;
1922
1923         /* Historical case to support raid1 reshape without delta disks */
1924         if (rs_is_raid1(rs)) {
1925                 if (rs->delta_disks)
1926                         return !!rs->delta_disks;
1927
1928                 return !change &&
1929                        mddev->raid_disks != rs->raid_disks;
1930         }
1931
1932         if (rs_is_raid10(rs))
1933                 return change &&
1934                        !__is_raid10_far(mddev->new_layout) &&
1935                        rs->delta_disks >= 0;
1936
1937         return change;
1938 }
1939
1940 /*  Features */
1941 #define FEATURE_FLAG_SUPPORTS_V190      0x1 /* Supports extended superblock */
1942
1943 /* State flags for sb->flags */
1944 #define SB_FLAG_RESHAPE_ACTIVE          0x1
1945 #define SB_FLAG_RESHAPE_BACKWARDS       0x2
1946
1947 /*
1948  * This structure is never routinely used by userspace, unlike md superblocks.
1949  * Devices with this superblock should only ever be accessed via device-mapper.
1950  */
1951 #define DM_RAID_MAGIC 0x64526D44
1952 struct dm_raid_superblock {
1953         __le32 magic;           /* "DmRd" */
1954         __le32 compat_features; /* Used to indicate compatible features (like 1.9.0 ondisk metadata extension) */
1955
1956         __le32 num_devices;     /* Number of devices in this raid set. (Max 64) */
1957         __le32 array_position;  /* The position of this drive in the raid set */
1958
1959         __le64 events;          /* Incremented by md when superblock updated */
1960         __le64 failed_devices;  /* Pre 1.9.0 part of bit field of devices to */
1961                                 /* indicate failures (see extension below) */
1962
1963         /*
1964          * This offset tracks the progress of the repair or replacement of
1965          * an individual drive.
1966          */
1967         __le64 disk_recovery_offset;
1968
1969         /*
1970          * This offset tracks the progress of the initial raid set
1971          * synchronisation/parity calculation.
1972          */
1973         __le64 array_resync_offset;
1974
1975         /*
1976          * raid characteristics
1977          */
1978         __le32 level;
1979         __le32 layout;
1980         __le32 stripe_sectors;
1981
1982         /********************************************************************
1983          * BELOW FOLLOW V1.9.0 EXTENSIONS TO THE PRISTINE SUPERBLOCK FORMAT!!!
1984          *
1985          * FEATURE_FLAG_SUPPORTS_V190 in the compat_features member indicates that those exist
1986          */
1987
1988         __le32 flags; /* Flags defining array states for reshaping */
1989
1990         /*
1991          * This offset tracks the progress of a raid
1992          * set reshape in order to be able to restart it
1993          */
1994         __le64 reshape_position;
1995
1996         /*
1997          * These define the properties of the array in case of an interrupted reshape
1998          */
1999         __le32 new_level;
2000         __le32 new_layout;
2001         __le32 new_stripe_sectors;
2002         __le32 delta_disks;
2003
2004         __le64 array_sectors; /* Array size in sectors */
2005
2006         /*
2007          * Sector offsets to data on devices (reshaping).
2008          * Needed to support out of place reshaping, thus
2009          * not writing over any stripes whilst converting
2010          * them from old to new layout
2011          */
2012         __le64 data_offset;
2013         __le64 new_data_offset;
2014
2015         __le64 sectors; /* Used device size in sectors */
2016
2017         /*
2018          * Additonal Bit field of devices indicating failures to support
2019          * up to 256 devices with the 1.9.0 on-disk metadata format
2020          */
2021         __le64 extended_failed_devices[DISKS_ARRAY_ELEMS - 1];
2022
2023         __le32 incompat_features;       /* Used to indicate any incompatible features */
2024
2025         /* Always set rest up to logical block size to 0 when writing (see get_metadata_device() below). */
2026 } __packed;
2027
2028 /*
2029  * Check for reshape constraints on raid set @rs:
2030  *
2031  * - reshape function non-existent
2032  * - degraded set
2033  * - ongoing recovery
2034  * - ongoing reshape
2035  *
2036  * Returns 0 if none or -EPERM if given constraint
2037  * and error message reference in @errmsg
2038  */
2039 static int rs_check_reshape(struct raid_set *rs)
2040 {
2041         struct mddev *mddev = &rs->md;
2042
2043         if (!mddev->pers || !mddev->pers->check_reshape)
2044                 rs->ti->error = "Reshape not supported";
2045         else if (mddev->degraded)
2046                 rs->ti->error = "Can't reshape degraded raid set";
2047         else if (rs_is_recovering(rs))
2048                 rs->ti->error = "Convert request on recovering raid set prohibited";
2049         else if (rs_is_reshaping(rs))
2050                 rs->ti->error = "raid set already reshaping!";
2051         else if (!(rs_is_raid1(rs) || rs_is_raid10(rs) || rs_is_raid456(rs)))
2052                 rs->ti->error = "Reshaping only supported for raid1/4/5/6/10";
2053         else
2054                 return 0;
2055
2056         return -EPERM;
2057 }
2058
2059 static int read_disk_sb(struct md_rdev *rdev, int size, bool force_reload)
2060 {
2061         BUG_ON(!rdev->sb_page);
2062
2063         if (rdev->sb_loaded && !force_reload)
2064                 return 0;
2065
2066         rdev->sb_loaded = 0;
2067
2068         if (!sync_page_io(rdev, 0, size, rdev->sb_page, REQ_OP_READ, 0, true)) {
2069                 DMERR("Failed to read superblock of device at position %d",
2070                       rdev->raid_disk);
2071                 md_error(rdev->mddev, rdev);
2072                 set_bit(Faulty, &rdev->flags);
2073                 return -EIO;
2074         }
2075
2076         rdev->sb_loaded = 1;
2077
2078         return 0;
2079 }
2080
2081 static void sb_retrieve_failed_devices(struct dm_raid_superblock *sb, uint64_t *failed_devices)
2082 {
2083         failed_devices[0] = le64_to_cpu(sb->failed_devices);
2084         memset(failed_devices + 1, 0, sizeof(sb->extended_failed_devices));
2085
2086         if (le32_to_cpu(sb->compat_features) & FEATURE_FLAG_SUPPORTS_V190) {
2087                 int i = ARRAY_SIZE(sb->extended_failed_devices);
2088
2089                 while (i--)
2090                         failed_devices[i+1] = le64_to_cpu(sb->extended_failed_devices[i]);
2091         }
2092 }
2093
2094 static void sb_update_failed_devices(struct dm_raid_superblock *sb, uint64_t *failed_devices)
2095 {
2096         int i = ARRAY_SIZE(sb->extended_failed_devices);
2097
2098         sb->failed_devices = cpu_to_le64(failed_devices[0]);
2099         while (i--)
2100                 sb->extended_failed_devices[i] = cpu_to_le64(failed_devices[i+1]);
2101 }
2102
2103 /*
2104  * Synchronize the superblock members with the raid set properties
2105  *
2106  * All superblock data is little endian.
2107  */
2108 static void super_sync(struct mddev *mddev, struct md_rdev *rdev)
2109 {
2110         bool update_failed_devices = false;
2111         unsigned int i;
2112         uint64_t failed_devices[DISKS_ARRAY_ELEMS];
2113         struct dm_raid_superblock *sb;
2114         struct raid_set *rs = container_of(mddev, struct raid_set, md);
2115
2116         /* No metadata device, no superblock */
2117         if (!rdev->meta_bdev)
2118                 return;
2119
2120         BUG_ON(!rdev->sb_page);
2121
2122         sb = page_address(rdev->sb_page);
2123
2124         sb_retrieve_failed_devices(sb, failed_devices);
2125
2126         for (i = 0; i < rs->raid_disks; i++)
2127                 if (!rs->dev[i].data_dev || test_bit(Faulty, &rs->dev[i].rdev.flags)) {
2128                         update_failed_devices = true;
2129                         set_bit(i, (void *) failed_devices);
2130                 }
2131
2132         if (update_failed_devices)
2133                 sb_update_failed_devices(sb, failed_devices);
2134
2135         sb->magic = cpu_to_le32(DM_RAID_MAGIC);
2136         sb->compat_features = cpu_to_le32(FEATURE_FLAG_SUPPORTS_V190);
2137
2138         sb->num_devices = cpu_to_le32(mddev->raid_disks);
2139         sb->array_position = cpu_to_le32(rdev->raid_disk);
2140
2141         sb->events = cpu_to_le64(mddev->events);
2142
2143         sb->disk_recovery_offset = cpu_to_le64(rdev->recovery_offset);
2144         sb->array_resync_offset = cpu_to_le64(mddev->recovery_cp);
2145
2146         sb->level = cpu_to_le32(mddev->level);
2147         sb->layout = cpu_to_le32(mddev->layout);
2148         sb->stripe_sectors = cpu_to_le32(mddev->chunk_sectors);
2149
2150         /********************************************************************
2151          * BELOW FOLLOW V1.9.0 EXTENSIONS TO THE PRISTINE SUPERBLOCK FORMAT!!!
2152          *
2153          * FEATURE_FLAG_SUPPORTS_V190 in the compat_features member indicates that those exist
2154          */
2155         sb->new_level = cpu_to_le32(mddev->new_level);
2156         sb->new_layout = cpu_to_le32(mddev->new_layout);
2157         sb->new_stripe_sectors = cpu_to_le32(mddev->new_chunk_sectors);
2158
2159         sb->delta_disks = cpu_to_le32(mddev->delta_disks);
2160
2161         smp_rmb(); /* Make sure we access most recent reshape position */
2162         sb->reshape_position = cpu_to_le64(mddev->reshape_position);
2163         if (le64_to_cpu(sb->reshape_position) != MaxSector) {
2164                 /* Flag ongoing reshape */
2165                 sb->flags |= cpu_to_le32(SB_FLAG_RESHAPE_ACTIVE);
2166
2167                 if (mddev->delta_disks < 0 || mddev->reshape_backwards)
2168                         sb->flags |= cpu_to_le32(SB_FLAG_RESHAPE_BACKWARDS);
2169         } else {
2170                 /* Clear reshape flags */
2171                 sb->flags &= ~(cpu_to_le32(SB_FLAG_RESHAPE_ACTIVE|SB_FLAG_RESHAPE_BACKWARDS));
2172         }
2173
2174         sb->array_sectors = cpu_to_le64(mddev->array_sectors);
2175         sb->data_offset = cpu_to_le64(rdev->data_offset);
2176         sb->new_data_offset = cpu_to_le64(rdev->new_data_offset);
2177         sb->sectors = cpu_to_le64(rdev->sectors);
2178         sb->incompat_features = cpu_to_le32(0);
2179
2180         /* Zero out the rest of the payload after the size of the superblock */
2181         memset(sb + 1, 0, rdev->sb_size - sizeof(*sb));
2182 }
2183
2184 /*
2185  * super_load
2186  *
2187  * This function creates a superblock if one is not found on the device
2188  * and will decide which superblock to use if there's a choice.
2189  *
2190  * Return: 1 if use rdev, 0 if use refdev, -Exxx otherwise
2191  */
2192 static int super_load(struct md_rdev *rdev, struct md_rdev *refdev)
2193 {
2194         int r;
2195         struct dm_raid_superblock *sb;
2196         struct dm_raid_superblock *refsb;
2197         uint64_t events_sb, events_refsb;
2198
2199         r = read_disk_sb(rdev, rdev->sb_size, false);
2200         if (r)
2201                 return r;
2202
2203         sb = page_address(rdev->sb_page);
2204
2205         /*
2206          * Two cases that we want to write new superblocks and rebuild:
2207          * 1) New device (no matching magic number)
2208          * 2) Device specified for rebuild (!In_sync w/ offset == 0)
2209          */
2210         if ((sb->magic != cpu_to_le32(DM_RAID_MAGIC)) ||
2211             (!test_bit(In_sync, &rdev->flags) && !rdev->recovery_offset)) {
2212                 super_sync(rdev->mddev, rdev);
2213
2214                 set_bit(FirstUse, &rdev->flags);
2215                 sb->compat_features = cpu_to_le32(FEATURE_FLAG_SUPPORTS_V190);
2216
2217                 /* Force writing of superblocks to disk */
2218                 set_bit(MD_SB_CHANGE_DEVS, &rdev->mddev->sb_flags);
2219
2220                 /* Any superblock is better than none, choose that if given */
2221                 return refdev ? 0 : 1;
2222         }
2223
2224         if (!refdev)
2225                 return 1;
2226
2227         events_sb = le64_to_cpu(sb->events);
2228
2229         refsb = page_address(refdev->sb_page);
2230         events_refsb = le64_to_cpu(refsb->events);
2231
2232         return (events_sb > events_refsb) ? 1 : 0;
2233 }
2234
2235 static int super_init_validation(struct raid_set *rs, struct md_rdev *rdev)
2236 {
2237         int role;
2238         unsigned int d;
2239         struct mddev *mddev = &rs->md;
2240         uint64_t events_sb;
2241         uint64_t failed_devices[DISKS_ARRAY_ELEMS];
2242         struct dm_raid_superblock *sb;
2243         uint32_t new_devs = 0, rebuild_and_new = 0, rebuilds = 0;
2244         struct md_rdev *r;
2245         struct dm_raid_superblock *sb2;
2246
2247         sb = page_address(rdev->sb_page);
2248         events_sb = le64_to_cpu(sb->events);
2249
2250         /*
2251          * Initialise to 1 if this is a new superblock.
2252          */
2253         mddev->events = events_sb ? : 1;
2254
2255         mddev->reshape_position = MaxSector;
2256
2257         mddev->raid_disks = le32_to_cpu(sb->num_devices);
2258         mddev->level = le32_to_cpu(sb->level);
2259         mddev->layout = le32_to_cpu(sb->layout);
2260         mddev->chunk_sectors = le32_to_cpu(sb->stripe_sectors);
2261
2262         /*
2263          * Reshaping is supported, e.g. reshape_position is valid
2264          * in superblock and superblock content is authoritative.
2265          */
2266         if (le32_to_cpu(sb->compat_features) & FEATURE_FLAG_SUPPORTS_V190) {
2267                 /* Superblock is authoritative wrt given raid set layout! */
2268                 mddev->new_level = le32_to_cpu(sb->new_level);
2269                 mddev->new_layout = le32_to_cpu(sb->new_layout);
2270                 mddev->new_chunk_sectors = le32_to_cpu(sb->new_stripe_sectors);
2271                 mddev->delta_disks = le32_to_cpu(sb->delta_disks);
2272                 mddev->array_sectors = le64_to_cpu(sb->array_sectors);
2273
2274                 /* raid was reshaping and got interrupted */
2275                 if (le32_to_cpu(sb->flags) & SB_FLAG_RESHAPE_ACTIVE) {
2276                         if (test_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags)) {
2277                                 DMERR("Reshape requested but raid set is still reshaping");
2278                                 return -EINVAL;
2279                         }
2280
2281                         if (mddev->delta_disks < 0 ||
2282                             (!mddev->delta_disks && (le32_to_cpu(sb->flags) & SB_FLAG_RESHAPE_BACKWARDS)))
2283                                 mddev->reshape_backwards = 1;
2284                         else
2285                                 mddev->reshape_backwards = 0;
2286
2287                         mddev->reshape_position = le64_to_cpu(sb->reshape_position);
2288                         rs->raid_type = get_raid_type_by_ll(mddev->level, mddev->layout);
2289                 }
2290
2291         } else {
2292                 /*
2293                  * No takeover/reshaping, because we don't have the extended v1.9.0 metadata
2294                  */
2295                 struct raid_type *rt_cur = get_raid_type_by_ll(mddev->level, mddev->layout);
2296                 struct raid_type *rt_new = get_raid_type_by_ll(mddev->new_level, mddev->new_layout);
2297
2298                 if (rs_takeover_requested(rs)) {
2299                         if (rt_cur && rt_new)
2300                                 DMERR("Takeover raid sets from %s to %s not yet supported by metadata. (raid level change)",
2301                                       rt_cur->name, rt_new->name);
2302                         else
2303                                 DMERR("Takeover raid sets not yet supported by metadata. (raid level change)");
2304                         return -EINVAL;
2305                 } else if (rs_reshape_requested(rs)) {
2306                         DMERR("Reshaping raid sets not yet supported by metadata. (raid layout change keeping level)");
2307                         if (mddev->layout != mddev->new_layout) {
2308                                 if (rt_cur && rt_new)
2309                                         DMERR("  current layout %s vs new layout %s",
2310                                               rt_cur->name, rt_new->name);
2311                                 else
2312                                         DMERR("  current layout 0x%X vs new layout 0x%X",
2313                                               le32_to_cpu(sb->layout), mddev->new_layout);
2314                         }
2315                         if (mddev->chunk_sectors != mddev->new_chunk_sectors)
2316                                 DMERR("  current stripe sectors %u vs new stripe sectors %u",
2317                                       mddev->chunk_sectors, mddev->new_chunk_sectors);
2318                         if (rs->delta_disks)
2319                                 DMERR("  current %u disks vs new %u disks",
2320                                       mddev->raid_disks, mddev->raid_disks + rs->delta_disks);
2321                         if (rs_is_raid10(rs)) {
2322                                 DMERR("  Old layout: %s w/ %u copies",
2323                                       raid10_md_layout_to_format(mddev->layout),
2324                                       raid10_md_layout_to_copies(mddev->layout));
2325                                 DMERR("  New layout: %s w/ %u copies",
2326                                       raid10_md_layout_to_format(mddev->new_layout),
2327                                       raid10_md_layout_to_copies(mddev->new_layout));
2328                         }
2329                         return -EINVAL;
2330                 }
2331
2332                 DMINFO("Discovered old metadata format; upgrading to extended metadata format");
2333         }
2334
2335         if (!test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))
2336                 mddev->recovery_cp = le64_to_cpu(sb->array_resync_offset);
2337
2338         /*
2339          * During load, we set FirstUse if a new superblock was written.
2340          * There are two reasons we might not have a superblock:
2341          * 1) The raid set is brand new - in which case, all of the
2342          *    devices must have their In_sync bit set.  Also,
2343          *    recovery_cp must be 0, unless forced.
2344          * 2) This is a new device being added to an old raid set
2345          *    and the new device needs to be rebuilt - in which
2346          *    case the In_sync bit will /not/ be set and
2347          *    recovery_cp must be MaxSector.
2348          * 3) This is/are a new device(s) being added to an old
2349          *    raid set during takeover to a higher raid level
2350          *    to provide capacity for redundancy or during reshape
2351          *    to add capacity to grow the raid set.
2352          */
2353         d = 0;
2354         rdev_for_each(r, mddev) {
2355                 if (test_bit(Journal, &rdev->flags))
2356                         continue;
2357
2358                 if (test_bit(FirstUse, &r->flags))
2359                         new_devs++;
2360
2361                 if (!test_bit(In_sync, &r->flags)) {
2362                         DMINFO("Device %d specified for rebuild; clearing superblock",
2363                                 r->raid_disk);
2364                         rebuilds++;
2365
2366                         if (test_bit(FirstUse, &r->flags))
2367                                 rebuild_and_new++;
2368                 }
2369
2370                 d++;
2371         }
2372
2373         if (new_devs == rs->raid_disks || !rebuilds) {
2374                 /* Replace a broken device */
2375                 if (new_devs == 1 && !rs->delta_disks)
2376                         ;
2377                 if (new_devs == rs->raid_disks) {
2378                         DMINFO("Superblocks created for new raid set");
2379                         set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
2380                 } else if (new_devs != rebuilds &&
2381                            new_devs != rs->delta_disks) {
2382                         DMERR("New device injected into existing raid set without "
2383                               "'delta_disks' or 'rebuild' parameter specified");
2384                         return -EINVAL;
2385                 }
2386         } else if (new_devs && new_devs != rebuilds) {
2387                 DMERR("%u 'rebuild' devices cannot be injected into"
2388                       " a raid set with %u other first-time devices",
2389                       rebuilds, new_devs);
2390                 return -EINVAL;
2391         } else if (rebuilds) {
2392                 if (rebuild_and_new && rebuilds != rebuild_and_new) {
2393                         DMERR("new device%s provided without 'rebuild'",
2394                               new_devs > 1 ? "s" : "");
2395                         return -EINVAL;
2396                 } else if (!test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags) && rs_is_recovering(rs)) {
2397                         DMERR("'rebuild' specified while raid set is not in-sync (recovery_cp=%llu)",
2398                               (unsigned long long) mddev->recovery_cp);
2399                         return -EINVAL;
2400                 } else if (rs_is_reshaping(rs)) {
2401                         DMERR("'rebuild' specified while raid set is being reshaped (reshape_position=%llu)",
2402                               (unsigned long long) mddev->reshape_position);
2403                         return -EINVAL;
2404                 }
2405         }
2406
2407         /*
2408          * Now we set the Faulty bit for those devices that are
2409          * recorded in the superblock as failed.
2410          */
2411         sb_retrieve_failed_devices(sb, failed_devices);
2412         rdev_for_each(r, mddev) {
2413                 if (test_bit(Journal, &rdev->flags) ||
2414                     !r->sb_page)
2415                         continue;
2416                 sb2 = page_address(r->sb_page);
2417                 sb2->failed_devices = 0;
2418                 memset(sb2->extended_failed_devices, 0, sizeof(sb2->extended_failed_devices));
2419
2420                 /*
2421                  * Check for any device re-ordering.
2422                  */
2423                 if (!test_bit(FirstUse, &r->flags) && (r->raid_disk >= 0)) {
2424                         role = le32_to_cpu(sb2->array_position);
2425                         if (role < 0)
2426                                 continue;
2427
2428                         if (role != r->raid_disk) {
2429                                 if (rs_is_raid10(rs) && __is_raid10_near(mddev->layout)) {
2430                                         if (mddev->raid_disks % __raid10_near_copies(mddev->layout) ||
2431                                             rs->raid_disks % rs->raid10_copies) {
2432                                                 rs->ti->error =
2433                                                         "Cannot change raid10 near set to odd # of devices!";
2434                                                 return -EINVAL;
2435                                         }
2436
2437                                         sb2->array_position = cpu_to_le32(r->raid_disk);
2438
2439                                 } else if (!(rs_is_raid10(rs) && rt_is_raid0(rs->raid_type)) &&
2440                                            !(rs_is_raid0(rs) && rt_is_raid10(rs->raid_type)) &&
2441                                            !rt_is_raid1(rs->raid_type)) {
2442                                         rs->ti->error = "Cannot change device positions in raid set";
2443                                         return -EINVAL;
2444                                 }
2445
2446                                 DMINFO("raid device #%d now at position #%d", role, r->raid_disk);
2447                         }
2448
2449                         /*
2450                          * Partial recovery is performed on
2451                          * returning failed devices.
2452                          */
2453                         if (test_bit(role, (void *) failed_devices))
2454                                 set_bit(Faulty, &r->flags);
2455                 }
2456         }
2457
2458         return 0;
2459 }
2460
2461 static int super_validate(struct raid_set *rs, struct md_rdev *rdev)
2462 {
2463         struct mddev *mddev = &rs->md;
2464         struct dm_raid_superblock *sb;
2465
2466         if (rs_is_raid0(rs) || !rdev->sb_page || rdev->raid_disk < 0)
2467                 return 0;
2468
2469         sb = page_address(rdev->sb_page);
2470
2471         /*
2472          * If mddev->events is not set, we know we have not yet initialized
2473          * the array.
2474          */
2475         if (!mddev->events && super_init_validation(rs, rdev))
2476                 return -EINVAL;
2477
2478         if (le32_to_cpu(sb->compat_features) &&
2479             le32_to_cpu(sb->compat_features) != FEATURE_FLAG_SUPPORTS_V190) {
2480                 rs->ti->error = "Unable to assemble array: Unknown flag(s) in compatible feature flags";
2481                 return -EINVAL;
2482         }
2483
2484         if (sb->incompat_features) {
2485                 rs->ti->error = "Unable to assemble array: No incompatible feature flags supported yet";
2486                 return -EINVAL;
2487         }
2488
2489         /* Enable bitmap creation for RAID levels != 0 */
2490         mddev->bitmap_info.offset = rt_is_raid0(rs->raid_type) ? 0 : to_sector(4096);
2491         mddev->bitmap_info.default_offset = mddev->bitmap_info.offset;
2492
2493         if (!test_and_clear_bit(FirstUse, &rdev->flags)) {
2494                 /*
2495                  * Retrieve rdev size stored in superblock to be prepared for shrink.
2496                  * Check extended superblock members are present otherwise the size
2497                  * will not be set!
2498                  */
2499                 if (le32_to_cpu(sb->compat_features) & FEATURE_FLAG_SUPPORTS_V190)
2500                         rdev->sectors = le64_to_cpu(sb->sectors);
2501
2502                 rdev->recovery_offset = le64_to_cpu(sb->disk_recovery_offset);
2503                 if (rdev->recovery_offset == MaxSector)
2504                         set_bit(In_sync, &rdev->flags);
2505                 /*
2506                  * If no reshape in progress -> we're recovering single
2507                  * disk(s) and have to set the device(s) to out-of-sync
2508                  */
2509                 else if (!rs_is_reshaping(rs))
2510                         clear_bit(In_sync, &rdev->flags); /* Mandatory for recovery */
2511         }
2512
2513         /*
2514          * If a device comes back, set it as not In_sync and no longer faulty.
2515          */
2516         if (test_and_clear_bit(Faulty, &rdev->flags)) {
2517                 rdev->recovery_offset = 0;
2518                 clear_bit(In_sync, &rdev->flags);
2519                 rdev->saved_raid_disk = rdev->raid_disk;
2520         }
2521
2522         /* Reshape support -> restore repective data offsets */
2523         rdev->data_offset = le64_to_cpu(sb->data_offset);
2524         rdev->new_data_offset = le64_to_cpu(sb->new_data_offset);
2525
2526         return 0;
2527 }
2528
2529 /*
2530  * Analyse superblocks and select the freshest.
2531  */
2532 static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
2533 {
2534         int r;
2535         struct md_rdev *rdev, *freshest;
2536         struct mddev *mddev = &rs->md;
2537
2538         freshest = NULL;
2539         rdev_for_each(rdev, mddev) {
2540                 if (test_bit(Journal, &rdev->flags))
2541                         continue;
2542
2543                 if (!rdev->meta_bdev)
2544                         continue;
2545
2546                 /* Set superblock offset/size for metadata device. */
2547                 rdev->sb_start = 0;
2548                 rdev->sb_size = bdev_logical_block_size(rdev->meta_bdev);
2549                 if (rdev->sb_size < sizeof(struct dm_raid_superblock) || rdev->sb_size > PAGE_SIZE) {
2550                         DMERR("superblock size of a logical block is no longer valid");
2551                         return -EINVAL;
2552                 }
2553
2554                 /*
2555                  * Skipping super_load due to CTR_FLAG_SYNC will cause
2556                  * the array to undergo initialization again as
2557                  * though it were new.  This is the intended effect
2558                  * of the "sync" directive.
2559                  *
2560                  * With reshaping capability added, we must ensure that
2561                  * that the "sync" directive is disallowed during the reshape.
2562                  */
2563                 if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags))
2564                         continue;
2565
2566                 r = super_load(rdev, freshest);
2567
2568                 switch (r) {
2569                 case 1:
2570                         freshest = rdev;
2571                         break;
2572                 case 0:
2573                         break;
2574                 default:
2575                         /* This is a failure to read the superblock from the metadata device. */
2576                         /*
2577                          * We have to keep any raid0 data/metadata device pairs or
2578                          * the MD raid0 personality will fail to start the array.
2579                          */
2580                         if (rs_is_raid0(rs))
2581                                 continue;
2582
2583                         /*
2584                          * We keep the dm_devs to be able to emit the device tuple
2585                          * properly on the table line in raid_status() (rather than
2586                          * mistakenly acting as if '- -' got passed into the constructor).
2587                          *
2588                          * The rdev has to stay on the same_set list to allow for
2589                          * the attempt to restore faulty devices on second resume.
2590                          */
2591                         rdev->raid_disk = rdev->saved_raid_disk = -1;
2592                         break;
2593                 }
2594         }
2595
2596         if (!freshest)
2597                 return 0;
2598
2599         /*
2600          * Validation of the freshest device provides the source of
2601          * validation for the remaining devices.
2602          */
2603         rs->ti->error = "Unable to assemble array: Invalid superblocks";
2604         if (super_validate(rs, freshest))
2605                 return -EINVAL;
2606
2607         if (validate_raid_redundancy(rs)) {
2608                 rs->ti->error = "Insufficient redundancy to activate array";
2609                 return -EINVAL;
2610         }
2611
2612         rdev_for_each(rdev, mddev)
2613                 if (!test_bit(Journal, &rdev->flags) &&
2614                     rdev != freshest &&
2615                     super_validate(rs, rdev))
2616                         return -EINVAL;
2617         return 0;
2618 }
2619
2620 /*
2621  * Adjust data_offset and new_data_offset on all disk members of @rs
2622  * for out of place reshaping if requested by contructor
2623  *
2624  * We need free space at the beginning of each raid disk for forward
2625  * and at the end for backward reshapes which userspace has to provide
2626  * via remapping/reordering of space.
2627  */
2628 static int rs_adjust_data_offsets(struct raid_set *rs)
2629 {
2630         sector_t data_offset = 0, new_data_offset = 0;
2631         struct md_rdev *rdev;
2632
2633         /* Constructor did not request data offset change */
2634         if (!test_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags)) {
2635                 if (!rs_is_reshapable(rs))
2636                         goto out;
2637
2638                 return 0;
2639         }
2640
2641         /* HM FIXME: get InSync raid_dev? */
2642         rdev = &rs->dev[0].rdev;
2643
2644         if (rs->delta_disks < 0) {
2645                 /*
2646                  * Removing disks (reshaping backwards):
2647                  *
2648                  * - before reshape: data is at offset 0 and free space
2649                  *                   is at end of each component LV
2650                  *
2651                  * - after reshape: data is at offset rs->data_offset != 0 on each component LV
2652                  */
2653                 data_offset = 0;
2654                 new_data_offset = rs->data_offset;
2655
2656         } else if (rs->delta_disks > 0) {
2657                 /*
2658                  * Adding disks (reshaping forwards):
2659                  *
2660                  * - before reshape: data is at offset rs->data_offset != 0 and
2661                  *                   free space is at begin of each component LV
2662                  *
2663                  * - after reshape: data is at offset 0 on each component LV
2664                  */
2665                 data_offset = rs->data_offset;
2666                 new_data_offset = 0;
2667
2668         } else {
2669                 /*
2670                  * User space passes in 0 for data offset after having removed reshape space
2671                  *
2672                  * - or - (data offset != 0)
2673                  *
2674                  * Changing RAID layout or chunk size -> toggle offsets
2675                  *
2676                  * - before reshape: data is at offset rs->data_offset 0 and
2677                  *                   free space is at end of each component LV
2678                  *                   -or-
2679                  *                   data is at offset rs->data_offset != 0 and
2680                  *                   free space is at begin of each component LV
2681                  *
2682                  * - after reshape: data is at offset 0 if it was at offset != 0
2683                  *                  or at offset != 0 if it was at offset 0
2684                  *                  on each component LV
2685                  *
2686                  */
2687                 data_offset = rs->data_offset ? rdev->data_offset : 0;
2688                 new_data_offset = data_offset ? 0 : rs->data_offset;
2689                 set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2690         }
2691
2692         /*
2693          * Make sure we got a minimum amount of free sectors per device
2694          */
2695         if (rs->data_offset &&
2696             to_sector(i_size_read(rdev->bdev->bd_inode)) - rs->md.dev_sectors < MIN_FREE_RESHAPE_SPACE) {
2697                 rs->ti->error = data_offset ? "No space for forward reshape" :
2698                                               "No space for backward reshape";
2699                 return -ENOSPC;
2700         }
2701 out:
2702         /*
2703          * Raise recovery_cp in case data_offset != 0 to
2704          * avoid false recovery positives in the constructor.
2705          */
2706         if (rs->md.recovery_cp < rs->md.dev_sectors)
2707                 rs->md.recovery_cp += rs->dev[0].rdev.data_offset;
2708
2709         /* Adjust data offsets on all rdevs but on any raid4/5/6 journal device */
2710         rdev_for_each(rdev, &rs->md) {
2711                 if (!test_bit(Journal, &rdev->flags)) {
2712                         rdev->data_offset = data_offset;
2713                         rdev->new_data_offset = new_data_offset;
2714                 }
2715         }
2716
2717         return 0;
2718 }
2719
2720 /* Userpace reordered disks -> adjust raid_disk indexes in @rs */
2721 static void __reorder_raid_disk_indexes(struct raid_set *rs)
2722 {
2723         int i = 0;
2724         struct md_rdev *rdev;
2725
2726         rdev_for_each(rdev, &rs->md) {
2727                 if (!test_bit(Journal, &rdev->flags)) {
2728                         rdev->raid_disk = i++;
2729                         rdev->saved_raid_disk = rdev->new_raid_disk = -1;
2730                 }
2731         }
2732 }
2733
2734 /*
2735  * Setup @rs for takeover by a different raid level
2736  */
2737 static int rs_setup_takeover(struct raid_set *rs)
2738 {
2739         struct mddev *mddev = &rs->md;
2740         struct md_rdev *rdev;
2741         unsigned int d = mddev->raid_disks = rs->raid_disks;
2742         sector_t new_data_offset = rs->dev[0].rdev.data_offset ? 0 : rs->data_offset;
2743
2744         if (rt_is_raid10(rs->raid_type)) {
2745                 if (rs_is_raid0(rs)) {
2746                         /* Userpace reordered disks -> adjust raid_disk indexes */
2747                         __reorder_raid_disk_indexes(rs);
2748
2749                         /* raid0 -> raid10_far layout */
2750                         mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_FAR,
2751                                                                    rs->raid10_copies);
2752                 } else if (rs_is_raid1(rs))
2753                         /* raid1 -> raid10_near layout */
2754                         mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_NEAR,
2755                                                                    rs->raid_disks);
2756                 else
2757                         return -EINVAL;
2758
2759         }
2760
2761         clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
2762         mddev->recovery_cp = MaxSector;
2763
2764         while (d--) {
2765                 rdev = &rs->dev[d].rdev;
2766
2767                 if (test_bit(d, (void *) rs->rebuild_disks)) {
2768                         clear_bit(In_sync, &rdev->flags);
2769                         clear_bit(Faulty, &rdev->flags);
2770                         mddev->recovery_cp = rdev->recovery_offset = 0;
2771                         /* Bitmap has to be created when we do an "up" takeover */
2772                         set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
2773                 }
2774
2775                 rdev->new_data_offset = new_data_offset;
2776         }
2777
2778         return 0;
2779 }
2780
2781 /* Prepare @rs for reshape */
2782 static int rs_prepare_reshape(struct raid_set *rs)
2783 {
2784         bool reshape;
2785         struct mddev *mddev = &rs->md;
2786
2787         if (rs_is_raid10(rs)) {
2788                 if (rs->raid_disks != mddev->raid_disks &&
2789                     __is_raid10_near(mddev->layout) &&
2790                     rs->raid10_copies &&
2791                     rs->raid10_copies != __raid10_near_copies(mddev->layout)) {
2792                         /*
2793                          * raid disk have to be multiple of data copies to allow this conversion,
2794                          *
2795                          * This is actually not a reshape it is a
2796                          * rebuild of any additional mirrors per group
2797                          */
2798                         if (rs->raid_disks % rs->raid10_copies) {
2799                                 rs->ti->error = "Can't reshape raid10 mirror groups";
2800                                 return -EINVAL;
2801                         }
2802
2803                         /* Userpace reordered disks to add/remove mirrors -> adjust raid_disk indexes */
2804                         __reorder_raid_disk_indexes(rs);
2805                         mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_NEAR,
2806                                                                    rs->raid10_copies);
2807                         mddev->new_layout = mddev->layout;
2808                         reshape = false;
2809                 } else
2810                         reshape = true;
2811
2812         } else if (rs_is_raid456(rs))
2813                 reshape = true;
2814
2815         else if (rs_is_raid1(rs)) {
2816                 if (rs->delta_disks) {
2817                         /* Process raid1 via delta_disks */
2818                         mddev->degraded = rs->delta_disks < 0 ? -rs->delta_disks : rs->delta_disks;
2819                         reshape = true;
2820                 } else {
2821                         /* Process raid1 without delta_disks */
2822                         mddev->raid_disks = rs->raid_disks;
2823                         reshape = false;
2824                 }
2825         } else {
2826                 rs->ti->error = "Called with bogus raid type";
2827                 return -EINVAL;
2828         }
2829
2830         if (reshape) {
2831                 set_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags);
2832                 set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2833         } else if (mddev->raid_disks < rs->raid_disks)
2834                 /* Create new superblocks and bitmaps, if any new disks */
2835                 set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2836
2837         return 0;
2838 }
2839
2840 /* Get reshape sectors from data_offsets or raid set */
2841 static sector_t _get_reshape_sectors(struct raid_set *rs)
2842 {
2843         struct md_rdev *rdev;
2844         sector_t reshape_sectors = 0;
2845
2846         rdev_for_each(rdev, &rs->md)
2847                 if (!test_bit(Journal, &rdev->flags)) {
2848                         reshape_sectors = (rdev->data_offset > rdev->new_data_offset) ?
2849                                         rdev->data_offset - rdev->new_data_offset :
2850                                         rdev->new_data_offset - rdev->data_offset;
2851                         break;
2852                 }
2853
2854         return max(reshape_sectors, (sector_t) rs->data_offset);
2855 }
2856
2857 /*
2858  *
2859  * - change raid layout
2860  * - change chunk size
2861  * - add disks
2862  * - remove disks
2863  */
2864 static int rs_setup_reshape(struct raid_set *rs)
2865 {
2866         int r = 0;
2867         unsigned int cur_raid_devs, d;
2868         sector_t reshape_sectors = _get_reshape_sectors(rs);
2869         struct mddev *mddev = &rs->md;
2870         struct md_rdev *rdev;
2871
2872         mddev->delta_disks = rs->delta_disks;
2873         cur_raid_devs = mddev->raid_disks;
2874
2875         /* Ignore impossible layout change whilst adding/removing disks */
2876         if (mddev->delta_disks &&
2877             mddev->layout != mddev->new_layout) {
2878                 DMINFO("Ignoring invalid layout change with delta_disks=%d", rs->delta_disks);
2879                 mddev->new_layout = mddev->layout;
2880         }
2881
2882         /*
2883          * Adjust array size:
2884          *
2885          * - in case of adding disk(s), array size has
2886          *   to grow after the disk adding reshape,
2887          *   which'll hapen in the event handler;
2888          *   reshape will happen forward, so space has to
2889          *   be available at the beginning of each disk
2890          *
2891          * - in case of removing disk(s), array size
2892          *   has to shrink before starting the reshape,
2893          *   which'll happen here;
2894          *   reshape will happen backward, so space has to
2895          *   be available at the end of each disk
2896          *
2897          * - data_offset and new_data_offset are
2898          *   adjusted for aforementioned out of place
2899          *   reshaping based on userspace passing in
2900          *   the "data_offset <sectors>" key/value
2901          *   pair via the constructor
2902          */
2903
2904         /* Add disk(s) */
2905         if (rs->delta_disks > 0) {
2906                 /* Prepare disks for check in raid4/5/6/10 {check|start}_reshape */
2907                 for (d = cur_raid_devs; d < rs->raid_disks; d++) {
2908                         rdev = &rs->dev[d].rdev;
2909                         clear_bit(In_sync, &rdev->flags);
2910
2911                         /*
2912                          * save_raid_disk needs to be -1, or recovery_offset will be set to 0
2913                          * by md, which'll store that erroneously in the superblock on reshape
2914                          */
2915                         rdev->saved_raid_disk = -1;
2916                         rdev->raid_disk = d;
2917
2918                         rdev->sectors = mddev->dev_sectors;
2919                         rdev->recovery_offset = rs_is_raid1(rs) ? 0 : MaxSector;
2920                 }
2921
2922                 mddev->reshape_backwards = 0; /* adding disk(s) -> forward reshape */
2923
2924         /* Remove disk(s) */
2925         } else if (rs->delta_disks < 0) {
2926                 r = rs_set_dev_and_array_sectors(rs, true);
2927                 mddev->reshape_backwards = 1; /* removing disk(s) -> backward reshape */
2928
2929         /* Change layout and/or chunk size */
2930         } else {
2931                 /*
2932                  * Reshape layout (e.g. raid5_ls -> raid5_n) and/or chunk size:
2933                  *
2934                  * keeping number of disks and do layout change ->
2935                  *
2936                  * toggle reshape_backward depending on data_offset:
2937                  *
2938                  * - free space upfront -> reshape forward
2939                  *
2940                  * - free space at the end -> reshape backward
2941                  *
2942                  *
2943                  * This utilizes free reshape space avoiding the need
2944                  * for userspace to move (parts of) LV segments in
2945                  * case of layout/chunksize change  (for disk
2946                  * adding/removing reshape space has to be at
2947                  * the proper address (see above with delta_disks):
2948                  *
2949                  * add disk(s)   -> begin
2950                  * remove disk(s)-> end
2951                  */
2952                 mddev->reshape_backwards = rs->dev[0].rdev.data_offset ? 0 : 1;
2953         }
2954
2955         /*
2956          * Adjust device size for forward reshape
2957          * because md_finish_reshape() reduces it.
2958          */
2959         if (!mddev->reshape_backwards)
2960                 rdev_for_each(rdev, &rs->md)
2961                         if (!test_bit(Journal, &rdev->flags))
2962                                 rdev->sectors += reshape_sectors;
2963
2964         return r;
2965 }
2966
2967 /*
2968  * Enable/disable discard support on RAID set depending on
2969  * RAID level and discard properties of underlying RAID members.
2970  */
2971 static void configure_discard_support(struct raid_set *rs)
2972 {
2973         int i;
2974         bool raid456;
2975         struct dm_target *ti = rs->ti;
2976
2977         /*
2978          * XXX: RAID level 4,5,6 require zeroing for safety.
2979          */
2980         raid456 = rs_is_raid456(rs);
2981
2982         for (i = 0; i < rs->raid_disks; i++) {
2983                 struct request_queue *q;
2984
2985                 if (!rs->dev[i].rdev.bdev)
2986                         continue;
2987
2988                 q = bdev_get_queue(rs->dev[i].rdev.bdev);
2989                 if (!q || !blk_queue_discard(q))
2990                         return;
2991
2992                 if (raid456) {
2993                         if (!devices_handle_discard_safely) {
2994                                 DMERR("raid456 discard support disabled due to discard_zeroes_data uncertainty.");
2995                                 DMERR("Set dm-raid.devices_handle_discard_safely=Y to override.");
2996                                 return;
2997                         }
2998                 }
2999         }
3000
3001         /*
3002          * RAID1 and RAID10 personalities require bio splitting,
3003          * RAID0/4/5/6 don't and process large discard bios properly.
3004          */
3005         ti->split_discard_bios = !!(rs_is_raid1(rs) || rs_is_raid10(rs));
3006         ti->num_discard_bios = 1;
3007 }
3008
3009 /*
3010  * Construct a RAID0/1/10/4/5/6 mapping:
3011  * Args:
3012  *      <raid_type> <#raid_params> <raid_params>{0,}    \
3013  *      <#raid_devs> [<meta_dev1> <dev1>]{1,}
3014  *
3015  * <raid_params> varies by <raid_type>.  See 'parse_raid_params' for
3016  * details on possible <raid_params>.
3017  *
3018  * Userspace is free to initialize the metadata devices, hence the superblocks to
3019  * enforce recreation based on the passed in table parameters.
3020  *
3021  */
3022 static int raid_ctr(struct dm_target *ti, unsigned int argc, char **argv)
3023 {
3024         int r;
3025         bool resize = false;
3026         struct raid_type *rt;
3027         unsigned int num_raid_params, num_raid_devs;
3028         sector_t calculated_dev_sectors, rdev_sectors, reshape_sectors;
3029         struct raid_set *rs = NULL;
3030         const char *arg;
3031         struct rs_layout rs_layout;
3032         struct dm_arg_set as = { argc, argv }, as_nrd;
3033         struct dm_arg _args[] = {
3034                 { 0, as.argc, "Cannot understand number of raid parameters" },
3035                 { 1, 254, "Cannot understand number of raid devices parameters" }
3036         };
3037
3038         /* Must have <raid_type> */
3039         arg = dm_shift_arg(&as);
3040         if (!arg) {
3041                 ti->error = "No arguments";
3042                 return -EINVAL;
3043         }
3044
3045         rt = get_raid_type(arg);
3046         if (!rt) {
3047                 ti->error = "Unrecognised raid_type";
3048                 return -EINVAL;
3049         }
3050
3051         /* Must have <#raid_params> */
3052         if (dm_read_arg_group(_args, &as, &num_raid_params, &ti->error))
3053                 return -EINVAL;
3054
3055         /* number of raid device tupples <meta_dev data_dev> */
3056         as_nrd = as;
3057         dm_consume_args(&as_nrd, num_raid_params);
3058         _args[1].max = (as_nrd.argc - 1) / 2;
3059         if (dm_read_arg(_args + 1, &as_nrd, &num_raid_devs, &ti->error))
3060                 return -EINVAL;
3061
3062         if (!__within_range(num_raid_devs, 1, MAX_RAID_DEVICES)) {
3063                 ti->error = "Invalid number of supplied raid devices";
3064                 return -EINVAL;
3065         }
3066
3067         rs = raid_set_alloc(ti, rt, num_raid_devs);
3068         if (IS_ERR(rs))
3069                 return PTR_ERR(rs);
3070
3071         r = parse_raid_params(rs, &as, num_raid_params);
3072         if (r)
3073                 goto bad;
3074
3075         r = parse_dev_params(rs, &as);
3076         if (r)
3077                 goto bad;
3078
3079         rs->md.sync_super = super_sync;
3080
3081         /*
3082          * Calculate ctr requested array and device sizes to allow
3083          * for superblock analysis needing device sizes defined.
3084          *
3085          * Any existing superblock will overwrite the array and device sizes
3086          */
3087         r = rs_set_dev_and_array_sectors(rs, false);
3088         if (r)
3089                 goto bad;
3090
3091         calculated_dev_sectors = rs->md.dev_sectors;
3092
3093         /*
3094          * Backup any new raid set level, layout, ...
3095          * requested to be able to compare to superblock
3096          * members for conversion decisions.
3097          */
3098         rs_config_backup(rs, &rs_layout);
3099
3100         r = analyse_superblocks(ti, rs);
3101         if (r)
3102                 goto bad;
3103
3104         rdev_sectors = __rdev_sectors(rs);
3105         if (!rdev_sectors) {
3106                 ti->error = "Invalid rdev size";
3107                 r = -EINVAL;
3108                 goto bad;
3109         }
3110
3111
3112         reshape_sectors = _get_reshape_sectors(rs);
3113         if (calculated_dev_sectors != rdev_sectors)
3114                 resize = calculated_dev_sectors != (reshape_sectors ? rdev_sectors - reshape_sectors : rdev_sectors);
3115
3116         INIT_WORK(&rs->md.event_work, do_table_event);
3117         ti->private = rs;
3118         ti->num_flush_bios = 1;
3119
3120         /* Restore any requested new layout for conversion decision */
3121         rs_config_restore(rs, &rs_layout);
3122
3123         /*
3124          * Now that we have any superblock metadata available,
3125          * check for new, recovering, reshaping, to be taken over,
3126          * to be reshaped or an existing, unchanged raid set to
3127          * run in sequence.
3128          */
3129         if (test_bit(MD_ARRAY_FIRST_USE, &rs->md.flags)) {
3130                 /* A new raid6 set has to be recovered to ensure proper parity and Q-Syndrome */
3131                 if (rs_is_raid6(rs) &&
3132                     test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
3133                         ti->error = "'nosync' not allowed for new raid6 set";
3134                         r = -EINVAL;
3135                         goto bad;
3136                 }
3137                 rs_setup_recovery(rs, 0);
3138                 set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
3139                 rs_set_new(rs);
3140         } else if (rs_is_recovering(rs)) {
3141                 /* A recovering raid set may be resized */
3142                 ; /* skip setup rs */
3143         } else if (rs_is_reshaping(rs)) {
3144                 /* Have to reject size change request during reshape */
3145                 if (resize) {
3146                         ti->error = "Can't resize a reshaping raid set";
3147                         r = -EPERM;
3148                         goto bad;
3149                 }
3150                 /* skip setup rs */
3151         } else if (rs_takeover_requested(rs)) {
3152                 if (rs_is_reshaping(rs)) {
3153                         ti->error = "Can't takeover a reshaping raid set";
3154                         r = -EPERM;
3155                         goto bad;
3156                 }
3157
3158                 /* We can't takeover a journaled raid4/5/6 */
3159                 if (test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
3160                         ti->error = "Can't takeover a journaled raid4/5/6 set";
3161                         r = -EPERM;
3162                         goto bad;
3163                 }
3164
3165                 /*
3166                  * If a takeover is needed, userspace sets any additional
3167                  * devices to rebuild and we can check for a valid request here.
3168                  *
3169                  * If acceptible, set the level to the new requested
3170                  * one, prohibit requesting recovery, allow the raid
3171                  * set to run and store superblocks during resume.
3172                  */
3173                 r = rs_check_takeover(rs);
3174                 if (r)
3175                         goto bad;
3176
3177                 r = rs_setup_takeover(rs);
3178                 if (r)
3179                         goto bad;
3180
3181                 set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
3182                 /* Takeover ain't recovery, so disable recovery */
3183                 rs_setup_recovery(rs, MaxSector);
3184                 rs_set_new(rs);
3185         } else if (rs_reshape_requested(rs)) {
3186                 /*
3187                  * No need to check for 'ongoing' takeover here, because takeover
3188                  * is an instant operation as oposed to an ongoing reshape.
3189                  */
3190
3191                 /* We can't reshape a journaled raid4/5/6 */
3192                 if (test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
3193                         ti->error = "Can't reshape a journaled raid4/5/6 set";
3194                         r = -EPERM;
3195                         goto bad;
3196                 }
3197
3198                 /* Out-of-place space has to be available to allow for a reshape unless raid1! */
3199                 if (reshape_sectors || rs_is_raid1(rs)) {
3200                         /*
3201                           * We can only prepare for a reshape here, because the
3202                           * raid set needs to run to provide the repective reshape
3203                           * check functions via its MD personality instance.
3204                           *
3205                           * So do the reshape check after md_run() succeeded.
3206                           */
3207                         r = rs_prepare_reshape(rs);
3208                         if (r)
3209                                 return r;
3210
3211                         /* Reshaping ain't recovery, so disable recovery */
3212                         rs_setup_recovery(rs, MaxSector);
3213                 }
3214                 rs_set_cur(rs);
3215         } else {
3216                 /* May not set recovery when a device rebuild is requested */
3217                 if (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags)) {
3218                         rs_setup_recovery(rs, MaxSector);
3219                         set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
3220                 } else
3221                         rs_setup_recovery(rs, test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags) ?
3222                                               0 : (resize ? calculated_dev_sectors : MaxSector));
3223                 rs_set_cur(rs);
3224         }
3225
3226         /* If constructor requested it, change data and new_data offsets */
3227         r = rs_adjust_data_offsets(rs);
3228         if (r)
3229                 goto bad;
3230
3231         /* Start raid set read-only and assumed clean to change in raid_resume() */
3232         rs->md.ro = 1;
3233         rs->md.in_sync = 1;
3234         set_bit(MD_RECOVERY_FROZEN, &rs->md.recovery);
3235
3236         /* Has to be held on running the array */
3237         mddev_lock_nointr(&rs->md);
3238         r = md_run(&rs->md);
3239         rs->md.in_sync = 0; /* Assume already marked dirty */
3240         if (r) {
3241                 ti->error = "Failed to run raid array";
3242                 mddev_unlock(&rs->md);
3243                 goto bad;
3244         }
3245
3246         r = md_start(&rs->md);
3247
3248         if (r) {
3249                 ti->error = "Failed to start raid array";
3250                 mddev_unlock(&rs->md);
3251                 goto bad_md_start;
3252         }
3253
3254         rs->callbacks.congested_fn = raid_is_congested;
3255         dm_table_add_target_callbacks(ti->table, &rs->callbacks);
3256
3257         /* If raid4/5/6 journal mode explictely requested (only possible with journal dev) -> set it */
3258         if (test_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags)) {
3259                 r = r5c_journal_mode_set(&rs->md, rs->journal_dev.mode);
3260                 if (r) {
3261                         ti->error = "Failed to set raid4/5/6 journal mode";
3262                         mddev_unlock(&rs->md);
3263                         goto bad_journal_mode_set;
3264                 }
3265         }
3266
3267         mddev_suspend(&rs->md);
3268         set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags);
3269
3270         /* Try to adjust the raid4/5/6 stripe cache size to the stripe size */
3271         if (rs_is_raid456(rs)) {
3272                 r = rs_set_raid456_stripe_cache(rs);
3273                 if (r)
3274                         goto bad_stripe_cache;
3275         }
3276
3277         /* Now do an early reshape check */
3278         if (test_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags)) {
3279                 r = rs_check_reshape(rs);
3280                 if (r)
3281                         goto bad_check_reshape;
3282
3283                 /* Restore new, ctr requested layout to perform check */
3284                 rs_config_restore(rs, &rs_layout);
3285
3286                 if (rs->md.pers->start_reshape) {
3287                         r = rs->md.pers->check_reshape(&rs->md);
3288                         if (r) {
3289                                 ti->error = "Reshape check failed";
3290                                 goto bad_check_reshape;
3291                         }
3292                 }
3293         }
3294
3295         /* Disable/enable discard support on raid set. */
3296         configure_discard_support(rs);
3297
3298         mddev_unlock(&rs->md);
3299         return 0;
3300
3301 bad_md_start:
3302 bad_journal_mode_set:
3303 bad_stripe_cache:
3304 bad_check_reshape:
3305         md_stop(&rs->md);
3306 bad:
3307         raid_set_free(rs);
3308
3309         return r;
3310 }
3311
3312 static void raid_dtr(struct dm_target *ti)
3313 {
3314         struct raid_set *rs = ti->private;
3315
3316         list_del_init(&rs->callbacks.list);
3317         md_stop(&rs->md);
3318         raid_set_free(rs);
3319 }
3320
3321 static int raid_map(struct dm_target *ti, struct bio *bio)
3322 {
3323         struct raid_set *rs = ti->private;
3324         struct mddev *mddev = &rs->md;
3325
3326         /*
3327          * If we're reshaping to add disk(s)), ti->len and
3328          * mddev->array_sectors will differ during the process
3329          * (ti->len > mddev->array_sectors), so we have to requeue
3330          * bios with addresses > mddev->array_sectors here or
3331          * there will occur accesses past EOD of the component
3332          * data images thus erroring the raid set.
3333          */
3334         if (unlikely(bio_end_sector(bio) > mddev->array_sectors))
3335                 return DM_MAPIO_REQUEUE;
3336
3337         md_handle_request(mddev, bio);
3338
3339         return DM_MAPIO_SUBMITTED;
3340 }
3341
3342 /* Return string describing the current sync action of @mddev */
3343 static const char *decipher_sync_action(struct mddev *mddev, unsigned long recovery)
3344 {
3345         if (test_bit(MD_RECOVERY_FROZEN, &recovery))
3346                 return "frozen";
3347
3348         /* The MD sync thread can be done with io but still be running */
3349         if (!test_bit(MD_RECOVERY_DONE, &recovery) &&
3350             (test_bit(MD_RECOVERY_RUNNING, &recovery) ||
3351              (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &recovery)))) {
3352                 if (test_bit(MD_RECOVERY_RESHAPE, &recovery))
3353                         return "reshape";
3354
3355                 if (test_bit(MD_RECOVERY_SYNC, &recovery)) {
3356                         if (!test_bit(MD_RECOVERY_REQUESTED, &recovery))
3357                                 return "resync";
3358                         else if (test_bit(MD_RECOVERY_CHECK, &recovery))
3359                                 return "check";
3360                         return "repair";
3361                 }
3362
3363                 if (test_bit(MD_RECOVERY_RECOVER, &recovery))
3364                         return "recover";
3365         }
3366
3367         return "idle";
3368 }
3369
3370 /*
3371  * Return status string for @rdev
3372  *
3373  * Status characters:
3374  *
3375  *  'D' = Dead/Failed raid set component or raid4/5/6 journal device
3376  *  'a' = Alive but not in-sync raid set component _or_ alive raid4/5/6 'write_back' journal device
3377  *  'A' = Alive and in-sync raid set component _or_ alive raid4/5/6 'write_through' journal device
3378  *  '-' = Non-existing device (i.e. uspace passed '- -' into the ctr)
3379  */
3380 static const char *__raid_dev_status(struct raid_set *rs, struct md_rdev *rdev)
3381 {
3382         if (!rdev->bdev)
3383                 return "-";
3384         else if (test_bit(Faulty, &rdev->flags))
3385                 return "D";
3386         else if (test_bit(Journal, &rdev->flags))
3387                 return (rs->journal_dev.mode == R5C_JOURNAL_MODE_WRITE_THROUGH) ? "A" : "a";
3388         else if (test_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags) ||
3389                  (!test_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags) &&
3390                   !test_bit(In_sync, &rdev->flags)))
3391                 return "a";
3392         else
3393                 return "A";
3394 }
3395
3396 /* Helper to return resync/reshape progress for @rs and runtime flags for raid set in sync / resynching */
3397 static sector_t rs_get_progress(struct raid_set *rs, unsigned long recovery,
3398                                 sector_t resync_max_sectors)
3399 {
3400         sector_t r;
3401         struct mddev *mddev = &rs->md;
3402
3403         clear_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3404         clear_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags);
3405
3406         if (rs_is_raid0(rs)) {
3407                 r = resync_max_sectors;
3408                 set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3409
3410         } else {
3411                 if (test_bit(MD_RECOVERY_NEEDED, &recovery) ||
3412                     test_bit(MD_RECOVERY_RESHAPE, &recovery) ||
3413                     test_bit(MD_RECOVERY_RUNNING, &recovery))
3414                         r = mddev->curr_resync_completed;
3415                 else
3416                         r = mddev->recovery_cp;
3417
3418                 if (r >= resync_max_sectors &&
3419                     (!test_bit(MD_RECOVERY_REQUESTED, &recovery) ||
3420                      (!test_bit(MD_RECOVERY_FROZEN, &recovery) &&
3421                       !test_bit(MD_RECOVERY_NEEDED, &recovery) &&
3422                       !test_bit(MD_RECOVERY_RUNNING, &recovery)))) {
3423                         /*
3424                          * Sync complete.
3425                          */
3426                         /* In case we have finished recovering, the array is in sync. */
3427                         if (test_bit(MD_RECOVERY_RECOVER, &recovery))
3428                                 set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3429
3430                 } else if (test_bit(MD_RECOVERY_RECOVER, &recovery)) {
3431                         /*
3432                          * In case we are recovering, the array is not in sync
3433                          * and health chars should show the recovering legs.
3434                          */
3435                         ;
3436
3437                 } else if (test_bit(MD_RECOVERY_SYNC, &recovery) &&
3438                            !test_bit(MD_RECOVERY_REQUESTED, &recovery)) {
3439                         /*
3440                          * If "resync" is occurring, the raid set
3441                          * is or may be out of sync hence the health
3442                          * characters shall be 'a'.
3443                          */
3444                         set_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags);
3445
3446                 } else if (test_bit(MD_RECOVERY_RESHAPE, &recovery) &&
3447                            !test_bit(MD_RECOVERY_REQUESTED, &recovery)) {
3448                         /*
3449                          * If "reshape" is occurring, the raid set
3450                          * is or may be out of sync hence the health
3451                          * characters shall be 'a'.
3452                          */
3453                         set_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags);
3454
3455                 } else if (test_bit(MD_RECOVERY_REQUESTED, &recovery)) {
3456                         /*
3457                          * If "check" or "repair" is occurring, the raid set has
3458                          * undergone an initial sync and the health characters
3459                          * should not be 'a' anymore.
3460                          */
3461                         set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3462
3463                 } else {
3464                         struct md_rdev *rdev;
3465
3466                         /*
3467                          * We are idle and recovery is needed, prevent 'A' chars race
3468                          * caused by components still set to in-sync by constrcuctor.
3469                          */
3470                         if (test_bit(MD_RECOVERY_NEEDED, &recovery))
3471                                 set_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags);
3472
3473                         /*
3474                          * The raid set may be doing an initial sync, or it may
3475                          * be rebuilding individual components.  If all the
3476                          * devices are In_sync, then it is the raid set that is
3477                          * being initialized.
3478                          */
3479                         set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3480                         rdev_for_each(rdev, mddev)
3481                                 if (!test_bit(Journal, &rdev->flags) &&
3482                                     !test_bit(In_sync, &rdev->flags)) {
3483                                         clear_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3484                                         break;
3485                                 }
3486                 }
3487         }
3488
3489         return min(r, resync_max_sectors);
3490 }
3491
3492 /* Helper to return @dev name or "-" if !@dev */
3493 static const char *__get_dev_name(struct dm_dev *dev)
3494 {
3495         return dev ? dev->name : "-";
3496 }
3497
3498 static void raid_status(struct dm_target *ti, status_type_t type,
3499                         unsigned int status_flags, char *result, unsigned int maxlen)
3500 {
3501         struct raid_set *rs = ti->private;
3502         struct mddev *mddev = &rs->md;
3503         struct r5conf *conf = mddev->private;
3504         int i, max_nr_stripes = conf ? conf->max_nr_stripes : 0;
3505         unsigned long recovery;
3506         unsigned int raid_param_cnt = 1; /* at least 1 for chunksize */
3507         unsigned int sz = 0;
3508         unsigned int rebuild_disks;
3509         unsigned int write_mostly_params = 0;
3510         sector_t progress, resync_max_sectors, resync_mismatches;
3511         const char *sync_action;
3512         struct raid_type *rt;
3513
3514         switch (type) {
3515         case STATUSTYPE_INFO:
3516                 /* *Should* always succeed */
3517                 rt = get_raid_type_by_ll(mddev->new_level, mddev->new_layout);
3518                 if (!rt)
3519                         return;
3520
3521                 DMEMIT("%s %d ", rt->name, mddev->raid_disks);
3522
3523                 /* Access most recent mddev properties for status output */
3524                 smp_rmb();
3525                 recovery = rs->md.recovery;
3526                 /* Get sensible max sectors even if raid set not yet started */
3527                 resync_max_sectors = test_bit(RT_FLAG_RS_PRERESUMED, &rs->runtime_flags) ?
3528                                       mddev->resync_max_sectors : mddev->dev_sectors;
3529                 progress = rs_get_progress(rs, recovery, resync_max_sectors);
3530                 resync_mismatches = (mddev->last_sync_action && !strcasecmp(mddev->last_sync_action, "check")) ?
3531                                     atomic64_read(&mddev->resync_mismatches) : 0;
3532                 sync_action = decipher_sync_action(&rs->md, recovery);
3533
3534                 /* HM FIXME: do we want another state char for raid0? It shows 'D'/'A'/'-' now */
3535                 for (i = 0; i < rs->raid_disks; i++)
3536                         DMEMIT(__raid_dev_status(rs, &rs->dev[i].rdev));
3537
3538                 /*
3539                  * In-sync/Reshape ratio:
3540                  *  The in-sync ratio shows the progress of:
3541                  *   - Initializing the raid set
3542                  *   - Rebuilding a subset of devices of the raid set
3543                  *  The user can distinguish between the two by referring
3544                  *  to the status characters.
3545                  *
3546                  *  The reshape ratio shows the progress of
3547                  *  changing the raid layout or the number of
3548                  *  disks of a raid set
3549                  */
3550                 DMEMIT(" %llu/%llu", (unsigned long long) progress,
3551                                      (unsigned long long) resync_max_sectors);
3552
3553                 /*
3554                  * v1.5.0+:
3555                  *
3556                  * Sync action:
3557                  *   See Documentation/device-mapper/dm-raid.txt for
3558                  *   information on each of these states.
3559                  */
3560                 DMEMIT(" %s", sync_action);
3561
3562                 /*
3563                  * v1.5.0+:
3564                  *
3565                  * resync_mismatches/mismatch_cnt
3566                  *   This field shows the number of discrepancies found when
3567                  *   performing a "check" of the raid set.
3568                  */
3569                 DMEMIT(" %llu", (unsigned long long) resync_mismatches);
3570
3571                 /*
3572                  * v1.9.0+:
3573                  *
3574                  * data_offset (needed for out of space reshaping)
3575                  *   This field shows the data offset into the data
3576                  *   image LV where the first stripes data starts.
3577                  *
3578                  * We keep data_offset equal on all raid disks of the set,
3579                  * so retrieving it from the first raid disk is sufficient.
3580                  */
3581                 DMEMIT(" %llu", (unsigned long long) rs->dev[0].rdev.data_offset);
3582
3583                 /*
3584                  * v1.10.0+:
3585                  */
3586                 DMEMIT(" %s", test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags) ?
3587                               __raid_dev_status(rs, &rs->journal_dev.rdev) : "-");
3588                 break;
3589
3590         case STATUSTYPE_TABLE:
3591                 /* Report the table line string you would use to construct this raid set */
3592
3593                 /* Calculate raid parameter count */
3594                 for (i = 0; i < rs->raid_disks; i++)
3595                         if (test_bit(WriteMostly, &rs->dev[i].rdev.flags))
3596                                 write_mostly_params += 2;
3597                 rebuild_disks = memweight(rs->rebuild_disks, DISKS_ARRAY_ELEMS * sizeof(*rs->rebuild_disks));
3598                 raid_param_cnt += rebuild_disks * 2 +
3599                                   write_mostly_params +
3600                                   hweight32(rs->ctr_flags & CTR_FLAG_OPTIONS_NO_ARGS) +
3601                                   hweight32(rs->ctr_flags & CTR_FLAG_OPTIONS_ONE_ARG) * 2 +
3602                                   (test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags) ? 2 : 0) +
3603                                   (test_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags) ? 2 : 0);
3604
3605                 /* Emit table line */
3606                 /* This has to be in the documented order for userspace! */
3607                 DMEMIT("%s %u %u", rs->raid_type->name, raid_param_cnt, mddev->new_chunk_sectors);
3608                 if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags))
3609                         DMEMIT(" %s", dm_raid_arg_name_by_flag(CTR_FLAG_SYNC));
3610                 if (test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))
3611                         DMEMIT(" %s", dm_raid_arg_name_by_flag(CTR_FLAG_NOSYNC));
3612                 if (rebuild_disks)
3613                         for (i = 0; i < rs->raid_disks; i++)
3614                                 if (test_bit(rs->dev[i].rdev.raid_disk, (void *) rs->rebuild_disks))
3615                                         DMEMIT(" %s %u", dm_raid_arg_name_by_flag(CTR_FLAG_REBUILD),
3616                                                          rs->dev[i].rdev.raid_disk);
3617                 if (test_bit(__CTR_FLAG_DAEMON_SLEEP, &rs->ctr_flags))
3618                         DMEMIT(" %s %lu", dm_raid_arg_name_by_flag(CTR_FLAG_DAEMON_SLEEP),
3619                                           mddev->bitmap_info.daemon_sleep);
3620                 if (test_bit(__CTR_FLAG_MIN_RECOVERY_RATE, &rs->ctr_flags))
3621                         DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_MIN_RECOVERY_RATE),
3622                                          mddev->sync_speed_min);
3623                 if (test_bit(__CTR_FLAG_MAX_RECOVERY_RATE, &rs->ctr_flags))
3624                         DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_MAX_RECOVERY_RATE),
3625                                          mddev->sync_speed_max);
3626                 if (write_mostly_params)
3627                         for (i = 0; i < rs->raid_disks; i++)
3628                                 if (test_bit(WriteMostly, &rs->dev[i].rdev.flags))
3629                                         DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_WRITE_MOSTLY),
3630                                                rs->dev[i].rdev.raid_disk);
3631                 if (test_bit(__CTR_FLAG_MAX_WRITE_BEHIND, &rs->ctr_flags))
3632                         DMEMIT(" %s %lu", dm_raid_arg_name_by_flag(CTR_FLAG_MAX_WRITE_BEHIND),
3633                                           mddev->bitmap_info.max_write_behind);
3634                 if (test_bit(__CTR_FLAG_STRIPE_CACHE, &rs->ctr_flags))
3635                         DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_STRIPE_CACHE),
3636                                          max_nr_stripes);
3637                 if (test_bit(__CTR_FLAG_REGION_SIZE, &rs->ctr_flags))
3638                         DMEMIT(" %s %llu", dm_raid_arg_name_by_flag(CTR_FLAG_REGION_SIZE),
3639                                            (unsigned long long) to_sector(mddev->bitmap_info.chunksize));
3640                 if (test_bit(__CTR_FLAG_RAID10_COPIES, &rs->ctr_flags))
3641                         DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_COPIES),
3642                                          raid10_md_layout_to_copies(mddev->layout));
3643                 if (test_bit(__CTR_FLAG_RAID10_FORMAT, &rs->ctr_flags))
3644                         DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_FORMAT),
3645                                          raid10_md_layout_to_format(mddev->layout));
3646                 if (test_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags))
3647                         DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_DELTA_DISKS),
3648                                          max(rs->delta_disks, mddev->delta_disks));
3649                 if (test_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags))
3650                         DMEMIT(" %s %llu", dm_raid_arg_name_by_flag(CTR_FLAG_DATA_OFFSET),
3651                                            (unsigned long long) rs->data_offset);
3652                 if (test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags))
3653                         DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_DEV),
3654                                         __get_dev_name(rs->journal_dev.dev));
3655                 if (test_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags))
3656                         DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_MODE),
3657                                          md_journal_mode_to_dm_raid(rs->journal_dev.mode));
3658                 DMEMIT(" %d", rs->raid_disks);
3659                 for (i = 0; i < rs->raid_disks; i++)
3660                         DMEMIT(" %s %s", __get_dev_name(rs->dev[i].meta_dev),
3661                                          __get_dev_name(rs->dev[i].data_dev));
3662         }
3663 }
3664
3665 static int raid_message(struct dm_target *ti, unsigned int argc, char **argv)
3666 {
3667         struct raid_set *rs = ti->private;
3668         struct mddev *mddev = &rs->md;
3669
3670         if (!mddev->pers || !mddev->pers->sync_request)
3671                 return -EINVAL;
3672
3673         if (!strcasecmp(argv[0], "frozen"))
3674                 set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3675         else
3676                 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3677
3678         if (!strcasecmp(argv[0], "idle") || !strcasecmp(argv[0], "frozen")) {
3679                 if (mddev->sync_thread) {
3680                         set_bit(MD_RECOVERY_INTR, &mddev->recovery);
3681                         md_reap_sync_thread(mddev);
3682                 }
3683         } else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
3684                    test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
3685                 return -EBUSY;
3686         else if (!strcasecmp(argv[0], "resync"))
3687                 ; /* MD_RECOVERY_NEEDED set below */
3688         else if (!strcasecmp(argv[0], "recover"))
3689                 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
3690         else {
3691                 if (!strcasecmp(argv[0], "check")) {
3692                         set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
3693                         set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
3694                         set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3695                 } else if (!strcasecmp(argv[0], "repair")) {
3696                         set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
3697                         set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3698                 } else
3699                         return -EINVAL;
3700         }
3701         if (mddev->ro == 2) {
3702                 /* A write to sync_action is enough to justify
3703                  * canceling read-auto mode
3704                  */
3705                 mddev->ro = 0;
3706                 if (!mddev->suspended && mddev->sync_thread)
3707                         md_wakeup_thread(mddev->sync_thread);
3708         }
3709         set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3710         if (!mddev->suspended && mddev->thread)
3711                 md_wakeup_thread(mddev->thread);
3712
3713         return 0;
3714 }
3715
3716 static int raid_iterate_devices(struct dm_target *ti,
3717                                 iterate_devices_callout_fn fn, void *data)
3718 {
3719         struct raid_set *rs = ti->private;
3720         unsigned int i;
3721         int r = 0;
3722
3723         for (i = 0; !r && i < rs->md.raid_disks; i++)
3724                 if (rs->dev[i].data_dev)
3725                         r = fn(ti,
3726                                  rs->dev[i].data_dev,
3727                                  0, /* No offset on data devs */
3728                                  rs->md.dev_sectors,
3729                                  data);
3730
3731         return r;
3732 }
3733
3734 static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
3735 {
3736         struct raid_set *rs = ti->private;
3737         unsigned int chunk_size = to_bytes(rs->md.chunk_sectors);
3738
3739         blk_limits_io_min(limits, chunk_size);
3740         blk_limits_io_opt(limits, chunk_size * mddev_data_stripes(rs));
3741 }
3742
3743 static void raid_postsuspend(struct dm_target *ti)
3744 {
3745         struct raid_set *rs = ti->private;
3746
3747         if (!test_and_set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) {
3748                 /* Writes have to be stopped before suspending to avoid deadlocks. */
3749                 if (!test_bit(MD_RECOVERY_FROZEN, &rs->md.recovery))
3750                         md_stop_writes(&rs->md);
3751
3752                 mddev_lock_nointr(&rs->md);
3753                 mddev_suspend(&rs->md);
3754                 mddev_unlock(&rs->md);
3755         }
3756 }
3757
3758 static void attempt_restore_of_faulty_devices(struct raid_set *rs)
3759 {
3760         int i;
3761         uint64_t cleared_failed_devices[DISKS_ARRAY_ELEMS];
3762         unsigned long flags;
3763         bool cleared = false;
3764         struct dm_raid_superblock *sb;
3765         struct mddev *mddev = &rs->md;
3766         struct md_rdev *r;
3767
3768         /* RAID personalities have to provide hot add/remove methods or we need to bail out. */
3769         if (!mddev->pers || !mddev->pers->hot_add_disk || !mddev->pers->hot_remove_disk)
3770                 return;
3771
3772         memset(cleared_failed_devices, 0, sizeof(cleared_failed_devices));
3773
3774         for (i = 0; i < mddev->raid_disks; i++) {
3775                 r = &rs->dev[i].rdev;
3776                 /* HM FIXME: enhance journal device recovery processing */
3777                 if (test_bit(Journal, &r->flags))
3778                         continue;
3779
3780                 if (test_bit(Faulty, &r->flags) &&
3781                     r->meta_bdev && !read_disk_sb(r, r->sb_size, true)) {
3782                         DMINFO("Faulty %s device #%d has readable super block."
3783                                "  Attempting to revive it.",
3784                                rs->raid_type->name, i);
3785
3786                         /*
3787                          * Faulty bit may be set, but sometimes the array can
3788                          * be suspended before the personalities can respond
3789                          * by removing the device from the array (i.e. calling
3790                          * 'hot_remove_disk').  If they haven't yet removed
3791                          * the failed device, its 'raid_disk' number will be
3792                          * '>= 0' - meaning we must call this function
3793                          * ourselves.
3794                          */
3795                         flags = r->flags;
3796                         clear_bit(In_sync, &r->flags); /* Mandatory for hot remove. */
3797                         if (r->raid_disk >= 0) {
3798                                 if (mddev->pers->hot_remove_disk(mddev, r)) {
3799                                         /* Failed to revive this device, try next */
3800                                         r->flags = flags;
3801                                         continue;
3802                                 }
3803                         } else
3804                                 r->raid_disk = r->saved_raid_disk = i;
3805
3806                         clear_bit(Faulty, &r->flags);
3807                         clear_bit(WriteErrorSeen, &r->flags);
3808
3809                         if (mddev->pers->hot_add_disk(mddev, r)) {
3810                                 /* Failed to revive this device, try next */
3811                                 r->raid_disk = r->saved_raid_disk = -1;
3812                                 r->flags = flags;
3813                         } else {
3814                                 clear_bit(In_sync, &r->flags);
3815                                 r->recovery_offset = 0;
3816                                 set_bit(i, (void *) cleared_failed_devices);
3817                                 cleared = true;
3818                         }
3819                 }
3820         }
3821
3822         /* If any failed devices could be cleared, update all sbs failed_devices bits */
3823         if (cleared) {
3824                 uint64_t failed_devices[DISKS_ARRAY_ELEMS];
3825
3826                 rdev_for_each(r, &rs->md) {
3827                         if (test_bit(Journal, &r->flags))
3828                                 continue;
3829
3830                         sb = page_address(r->sb_page);
3831                         sb_retrieve_failed_devices(sb, failed_devices);
3832
3833                         for (i = 0; i < DISKS_ARRAY_ELEMS; i++)
3834                                 failed_devices[i] &= ~cleared_failed_devices[i];
3835
3836                         sb_update_failed_devices(sb, failed_devices);
3837                 }
3838         }
3839 }
3840
3841 static int __load_dirty_region_bitmap(struct raid_set *rs)
3842 {
3843         int r = 0;
3844
3845         /* Try loading the bitmap unless "raid0", which does not have one */
3846         if (!rs_is_raid0(rs) &&
3847             !test_and_set_bit(RT_FLAG_RS_BITMAP_LOADED, &rs->runtime_flags)) {
3848                 r = bitmap_load(&rs->md);
3849                 if (r)
3850                         DMERR("Failed to load bitmap");
3851         }
3852
3853         return r;
3854 }
3855
3856 /* Enforce updating all superblocks */
3857 static void rs_update_sbs(struct raid_set *rs)
3858 {
3859         struct mddev *mddev = &rs->md;
3860         int ro = mddev->ro;
3861
3862         set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
3863         mddev->ro = 0;
3864         md_update_sb(mddev, 1);
3865         mddev->ro = ro;
3866 }
3867
3868 /*
3869  * Reshape changes raid algorithm of @rs to new one within personality
3870  * (e.g. raid6_zr -> raid6_nc), changes stripe size, adds/removes
3871  * disks from a raid set thus growing/shrinking it or resizes the set
3872  *
3873  * Call mddev_lock_nointr() before!
3874  */
3875 static int rs_start_reshape(struct raid_set *rs)
3876 {
3877         int r;
3878         struct mddev *mddev = &rs->md;
3879         struct md_personality *pers = mddev->pers;
3880
3881         r = rs_setup_reshape(rs);
3882         if (r)
3883                 return r;
3884
3885         /* Need to be resumed to be able to start reshape, recovery is frozen until raid_resume() though */
3886         if (test_and_clear_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags))
3887                 mddev_resume(mddev);
3888
3889         /*
3890          * Check any reshape constraints enforced by the personalility
3891          *
3892          * May as well already kick the reshape off so that * pers->start_reshape() becomes optional.
3893          */
3894         r = pers->check_reshape(mddev);
3895         if (r) {
3896                 rs->ti->error = "pers->check_reshape() failed";
3897                 return r;
3898         }
3899
3900         /*
3901          * Personality may not provide start reshape method in which
3902          * case check_reshape above has already covered everything
3903          */
3904         if (pers->start_reshape) {
3905                 r = pers->start_reshape(mddev);
3906                 if (r) {
3907                         rs->ti->error = "pers->start_reshape() failed";
3908                         return r;
3909                 }
3910         }
3911
3912         /* Suspend because a resume will happen in raid_resume() */
3913         set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags);
3914         mddev_suspend(mddev);
3915
3916         /*
3917          * Now reshape got set up, update superblocks to
3918          * reflect the fact so that a table reload will
3919          * access proper superblock content in the ctr.
3920          */
3921         rs_update_sbs(rs);
3922
3923         return 0;
3924 }
3925
3926 static int raid_preresume(struct dm_target *ti)
3927 {
3928         int r;
3929         struct raid_set *rs = ti->private;
3930         struct mddev *mddev = &rs->md;
3931
3932         /* This is a resume after a suspend of the set -> it's already started. */
3933         if (test_and_set_bit(RT_FLAG_RS_PRERESUMED, &rs->runtime_flags))
3934                 return 0;
3935
3936         if (!test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags)) {
3937                 struct raid_set *rs_active = rs_find_active(rs);
3938
3939                 if (rs_active) {
3940                         /*
3941                          * In case no rebuilds have been requested
3942                          * and an active table slot exists, copy
3943                          * current resynchonization completed and
3944                          * reshape position pointers across from
3945                          * suspended raid set in the active slot.
3946                          *
3947                          * This resumes the new mapping at current
3948                          * offsets to continue recover/reshape without
3949                          * necessarily redoing a raid set partially or
3950                          * causing data corruption in case of a reshape.
3951                          */
3952                         if (rs_active->md.curr_resync_completed != MaxSector)
3953                                 mddev->curr_resync_completed = rs_active->md.curr_resync_completed;
3954                         if (rs_active->md.reshape_position != MaxSector)
3955                                 mddev->reshape_position = rs_active->md.reshape_position;
3956                 }
3957         }
3958
3959         /*
3960          * The superblocks need to be updated on disk if the
3961          * array is new or new devices got added (thus zeroed
3962          * out by userspace) or __load_dirty_region_bitmap
3963          * will overwrite them in core with old data or fail.
3964          */
3965         if (test_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags))
3966                 rs_update_sbs(rs);
3967
3968         /* Load the bitmap from disk unless raid0 */
3969         r = __load_dirty_region_bitmap(rs);
3970         if (r)
3971                 return r;
3972
3973         /* Resize bitmap to adjust to changed region size (aka MD bitmap chunksize) */
3974         if (test_bit(RT_FLAG_RS_BITMAP_LOADED, &rs->runtime_flags) && mddev->bitmap &&
3975             mddev->bitmap_info.chunksize != to_bytes(rs->requested_bitmap_chunk_sectors)) {
3976                 r = bitmap_resize(mddev->bitmap, mddev->dev_sectors,
3977                                   to_bytes(rs->requested_bitmap_chunk_sectors), 0);
3978                 if (r)
3979                         DMERR("Failed to resize bitmap");
3980         }
3981
3982         /* Check for any resize/reshape on @rs and adjust/initiate */
3983         /* Be prepared for mddev_resume() in raid_resume() */
3984         set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3985         if (mddev->recovery_cp && mddev->recovery_cp < MaxSector) {
3986                 set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3987                 mddev->resync_min = mddev->recovery_cp;
3988         }
3989
3990         /* Check for any reshape request unless new raid set */
3991         if (test_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags)) {
3992                 /* Initiate a reshape. */
3993                 rs_set_rdev_sectors(rs);
3994                 mddev_lock_nointr(mddev);
3995                 r = rs_start_reshape(rs);
3996                 mddev_unlock(mddev);
3997                 if (r)
3998                         DMWARN("Failed to check/start reshape, continuing without change");
3999                 r = 0;
4000         }
4001
4002         return r;
4003 }
4004
4005 static void raid_resume(struct dm_target *ti)
4006 {
4007         struct raid_set *rs = ti->private;
4008         struct mddev *mddev = &rs->md;
4009
4010         if (test_and_set_bit(RT_FLAG_RS_RESUMED, &rs->runtime_flags)) {
4011                 /*
4012                  * A secondary resume while the device is active.
4013                  * Take this opportunity to check whether any failed
4014                  * devices are reachable again.
4015                  */
4016                 attempt_restore_of_faulty_devices(rs);
4017         }
4018
4019         if (test_and_clear_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) {
4020                 /* Only reduce raid set size before running a disk removing reshape. */
4021                 if (mddev->delta_disks < 0)
4022                         rs_set_capacity(rs);
4023
4024                 mddev_lock_nointr(mddev);
4025                 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4026                 mddev->ro = 0;
4027                 mddev->in_sync = 0;
4028                 mddev_resume(mddev);
4029                 mddev_unlock(mddev);
4030         }
4031 }
4032
4033 static struct target_type raid_target = {
4034         .name = "raid",
4035         .version = {1, 13, 2},
4036         .module = THIS_MODULE,
4037         .ctr = raid_ctr,
4038         .dtr = raid_dtr,
4039         .map = raid_map,
4040         .status = raid_status,
4041         .message = raid_message,
4042         .iterate_devices = raid_iterate_devices,
4043         .io_hints = raid_io_hints,
4044         .postsuspend = raid_postsuspend,
4045         .preresume = raid_preresume,
4046         .resume = raid_resume,
4047 };
4048
4049 static int __init dm_raid_init(void)
4050 {
4051         DMINFO("Loading target version %u.%u.%u",
4052                raid_target.version[0],
4053                raid_target.version[1],
4054                raid_target.version[2]);
4055         return dm_register_target(&raid_target);
4056 }
4057
4058 static void __exit dm_raid_exit(void)
4059 {
4060         dm_unregister_target(&raid_target);
4061 }
4062
4063 module_init(dm_raid_init);
4064 module_exit(dm_raid_exit);
4065
4066 module_param(devices_handle_discard_safely, bool, 0644);
4067 MODULE_PARM_DESC(devices_handle_discard_safely,
4068                  "Set to Y if all devices in each array reliably return zeroes on reads from discarded regions");
4069
4070 MODULE_DESCRIPTION(DM_NAME " raid0/1/10/4/5/6 target");
4071 MODULE_ALIAS("dm-raid0");
4072 MODULE_ALIAS("dm-raid1");
4073 MODULE_ALIAS("dm-raid10");
4074 MODULE_ALIAS("dm-raid4");
4075 MODULE_ALIAS("dm-raid5");
4076 MODULE_ALIAS("dm-raid6");
4077 MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>");
4078 MODULE_AUTHOR("Heinz Mauelshagen <dm-devel@redhat.com>");
4079 MODULE_LICENSE("GPL");