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v3.1
   1/*
   2 * Copyright (C) 2010-2011 Neil Brown
   3 * Copyright (C) 2010-2011 Red Hat, Inc. All rights reserved.
   4 *
   5 * This file is released under the GPL.
   6 */
   7
   8#include <linux/slab.h>
 
   9
  10#include "md.h"
  11#include "raid1.h"
  12#include "raid5.h"
 
  13#include "bitmap.h"
  14
  15#include <linux/device-mapper.h>
  16
  17#define DM_MSG_PREFIX "raid"
 
 
 
 
 
 
 
 
  18
  19/*
  20 * The following flags are used by dm-raid.c to set up the array state.
  21 * They must be cleared before md_run is called.
  22 */
  23#define FirstUse 10             /* rdev flag */
  24
  25struct raid_dev {
  26	/*
  27	 * Two DM devices, one to hold metadata and one to hold the
  28	 * actual data/parity.  The reason for this is to not confuse
  29	 * ti->len and give more flexibility in altering size and
  30	 * characteristics.
  31	 *
  32	 * While it is possible for this device to be associated
  33	 * with a different physical device than the data_dev, it
  34	 * is intended for it to be the same.
  35	 *    |--------- Physical Device ---------|
  36	 *    |- meta_dev -|------ data_dev ------|
  37	 */
  38	struct dm_dev *meta_dev;
  39	struct dm_dev *data_dev;
  40	struct mdk_rdev_s rdev;
  41};
  42
  43/*
  44 * Flags for rs->print_flags field.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  45 */
  46#define DMPF_SYNC              0x1
  47#define DMPF_NOSYNC            0x2
  48#define DMPF_REBUILD           0x4
  49#define DMPF_DAEMON_SLEEP      0x8
  50#define DMPF_MIN_RECOVERY_RATE 0x10
  51#define DMPF_MAX_RECOVERY_RATE 0x20
  52#define DMPF_MAX_WRITE_BEHIND  0x40
  53#define DMPF_STRIPE_CACHE      0x80
  54#define DMPF_REGION_SIZE       0X100
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  55struct raid_set {
  56	struct dm_target *ti;
  57
  58	uint64_t print_flags;
 
 
 
 
 
 
 
 
 
 
 
  59
  60	struct mddev_s md;
  61	struct raid_type *raid_type;
  62	struct dm_target_callbacks callbacks;
  63
  64	struct raid_dev dev[0];
  65};
  66
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  67/* Supported raid types and properties. */
  68static struct raid_type {
  69	const char *name;		/* RAID algorithm. */
  70	const char *descr;		/* Descriptor text for logging. */
  71	const unsigned parity_devs;	/* # of parity devices. */
  72	const unsigned minimal_devs;	/* minimal # of devices in set. */
  73	const unsigned level;		/* RAID level. */
  74	const unsigned algorithm;	/* RAID algorithm. */
  75} raid_types[] = {
  76	{"raid1",    "RAID1 (mirroring)",               0, 2, 1, 0 /* NONE */},
  77	{"raid4",    "RAID4 (dedicated parity disk)",	1, 2, 5, ALGORITHM_PARITY_0},
  78	{"raid5_la", "RAID5 (left asymmetric)",		1, 2, 5, ALGORITHM_LEFT_ASYMMETRIC},
  79	{"raid5_ra", "RAID5 (right asymmetric)",	1, 2, 5, ALGORITHM_RIGHT_ASYMMETRIC},
  80	{"raid5_ls", "RAID5 (left symmetric)",		1, 2, 5, ALGORITHM_LEFT_SYMMETRIC},
  81	{"raid5_rs", "RAID5 (right symmetric)",		1, 2, 5, ALGORITHM_RIGHT_SYMMETRIC},
  82	{"raid6_zr", "RAID6 (zero restart)",		2, 4, 6, ALGORITHM_ROTATING_ZERO_RESTART},
  83	{"raid6_nr", "RAID6 (N restart)",		2, 4, 6, ALGORITHM_ROTATING_N_RESTART},
  84	{"raid6_nc", "RAID6 (N continue)",		2, 4, 6, ALGORITHM_ROTATING_N_CONTINUE}
 
 
 
 
 
 
 
 
 
 
 
  85};
  86
  87static struct raid_type *get_raid_type(char *name)
 
  88{
  89	int i;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  90
  91	for (i = 0; i < ARRAY_SIZE(raid_types); i++)
  92		if (!strcmp(raid_types[i].name, name))
  93			return &raid_types[i];
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
  94
  95	return NULL;
  96}
  97
  98static struct raid_set *context_alloc(struct dm_target *ti, struct raid_type *raid_type, unsigned raid_devs)
 
 
 
 
  99{
 100	unsigned i;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 101	struct raid_set *rs;
 102	sector_t sectors_per_dev;
 103
 104	if (raid_devs <= raid_type->parity_devs) {
 105		ti->error = "Insufficient number of devices";
 106		return ERR_PTR(-EINVAL);
 107	}
 108
 109	sectors_per_dev = ti->len;
 110	if ((raid_type->level > 1) &&
 111	    sector_div(sectors_per_dev, (raid_devs - raid_type->parity_devs))) {
 112		ti->error = "Target length not divisible by number of data devices";
 113		return ERR_PTR(-EINVAL);
 114	}
 115
 116	rs = kzalloc(sizeof(*rs) + raid_devs * sizeof(rs->dev[0]), GFP_KERNEL);
 117	if (!rs) {
 118		ti->error = "Cannot allocate raid context";
 119		return ERR_PTR(-ENOMEM);
 120	}
 121
 122	mddev_init(&rs->md);
 123
 
 
 
 124	rs->ti = ti;
 125	rs->raid_type = raid_type;
 
 126	rs->md.raid_disks = raid_devs;
 127	rs->md.level = raid_type->level;
 128	rs->md.new_level = rs->md.level;
 129	rs->md.dev_sectors = sectors_per_dev;
 130	rs->md.layout = raid_type->algorithm;
 131	rs->md.new_layout = rs->md.layout;
 132	rs->md.delta_disks = 0;
 133	rs->md.recovery_cp = 0;
 134
 135	for (i = 0; i < raid_devs; i++)
 136		md_rdev_init(&rs->dev[i].rdev);
 137
 138	/*
 139	 * Remaining items to be initialized by further RAID params:
 140	 *  rs->md.persistent
 141	 *  rs->md.external
 142	 *  rs->md.chunk_sectors
 143	 *  rs->md.new_chunk_sectors
 
 144	 */
 145
 146	return rs;
 147}
 148
 149static void context_free(struct raid_set *rs)
 150{
 151	int i;
 152
 153	for (i = 0; i < rs->md.raid_disks; i++) {
 154		if (rs->dev[i].meta_dev)
 155			dm_put_device(rs->ti, rs->dev[i].meta_dev);
 156		if (rs->dev[i].rdev.sb_page)
 157			put_page(rs->dev[i].rdev.sb_page);
 158		rs->dev[i].rdev.sb_page = NULL;
 159		rs->dev[i].rdev.sb_loaded = 0;
 160		if (rs->dev[i].data_dev)
 161			dm_put_device(rs->ti, rs->dev[i].data_dev);
 162	}
 163
 164	kfree(rs);
 165}
 166
 167/*
 168 * For every device we have two words
 169 *  <meta_dev>: meta device name or '-' if missing
 170 *  <data_dev>: data device name or '-' if missing
 171 *
 172 * The following are permitted:
 173 *    - -
 174 *    - <data_dev>
 175 *    <meta_dev> <data_dev>
 176 *
 177 * The following is not allowed:
 178 *    <meta_dev> -
 179 *
 180 * This code parses those words.  If there is a failure,
 181 * the caller must use context_free to unwind the operations.
 182 */
 183static int dev_parms(struct raid_set *rs, char **argv)
 184{
 185	int i;
 186	int rebuild = 0;
 187	int metadata_available = 0;
 188	int ret = 0;
 
 189
 190	for (i = 0; i < rs->md.raid_disks; i++, argv += 2) {
 
 
 
 
 
 191		rs->dev[i].rdev.raid_disk = i;
 192
 193		rs->dev[i].meta_dev = NULL;
 194		rs->dev[i].data_dev = NULL;
 195
 196		/*
 197		 * There are no offsets, since there is a separate device
 198		 * for data and metadata.
 199		 */
 200		rs->dev[i].rdev.data_offset = 0;
 201		rs->dev[i].rdev.mddev = &rs->md;
 202
 203		if (strcmp(argv[0], "-")) {
 204			ret = dm_get_device(rs->ti, argv[0],
 205					    dm_table_get_mode(rs->ti->table),
 206					    &rs->dev[i].meta_dev);
 207			rs->ti->error = "RAID metadata device lookup failure";
 208			if (ret)
 209				return ret;
 
 
 
 
 210
 211			rs->dev[i].rdev.sb_page = alloc_page(GFP_KERNEL);
 212			if (!rs->dev[i].rdev.sb_page)
 
 213				return -ENOMEM;
 
 214		}
 215
 216		if (!strcmp(argv[1], "-")) {
 
 
 
 
 217			if (!test_bit(In_sync, &rs->dev[i].rdev.flags) &&
 218			    (!rs->dev[i].rdev.recovery_offset)) {
 219				rs->ti->error = "Drive designated for rebuild not specified";
 220				return -EINVAL;
 221			}
 222
 223			rs->ti->error = "No data device supplied with metadata device";
 224			if (rs->dev[i].meta_dev)
 225				return -EINVAL;
 
 226
 227			continue;
 228		}
 229
 230		ret = dm_get_device(rs->ti, argv[1],
 231				    dm_table_get_mode(rs->ti->table),
 232				    &rs->dev[i].data_dev);
 233		if (ret) {
 234			rs->ti->error = "RAID device lookup failure";
 235			return ret;
 236		}
 237
 238		if (rs->dev[i].meta_dev) {
 239			metadata_available = 1;
 240			rs->dev[i].rdev.meta_bdev = rs->dev[i].meta_dev->bdev;
 241		}
 242		rs->dev[i].rdev.bdev = rs->dev[i].data_dev->bdev;
 243		list_add(&rs->dev[i].rdev.same_set, &rs->md.disks);
 244		if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
 245			rebuild++;
 246	}
 247
 248	if (metadata_available) {
 249		rs->md.external = 0;
 250		rs->md.persistent = 1;
 251		rs->md.major_version = 2;
 252	} else if (rebuild && !rs->md.recovery_cp) {
 253		/*
 254		 * Without metadata, we will not be able to tell if the array
 255		 * is in-sync or not - we must assume it is not.  Therefore,
 256		 * it is impossible to rebuild a drive.
 257		 *
 258		 * Even if there is metadata, the on-disk information may
 259		 * indicate that the array is not in-sync and it will then
 260		 * fail at that time.
 261		 *
 262		 * User could specify 'nosync' option if desperate.
 263		 */
 264		DMERR("Unable to rebuild drive while array is not in-sync");
 265		rs->ti->error = "RAID device lookup failure";
 266		return -EINVAL;
 267	}
 268
 269	return 0;
 270}
 271
 272/*
 273 * validate_region_size
 274 * @rs
 275 * @region_size:  region size in sectors.  If 0, pick a size (4MiB default).
 276 *
 277 * Set rs->md.bitmap_info.chunksize (which really refers to 'region size').
 278 * Ensure that (ti->len/region_size < 2^21) - required by MD bitmap.
 279 *
 280 * Returns: 0 on success, -EINVAL on failure.
 281 */
 282static int validate_region_size(struct raid_set *rs, unsigned long region_size)
 283{
 284	unsigned long min_region_size = rs->ti->len / (1 << 21);
 285
 
 
 
 286	if (!region_size) {
 287		/*
 288		 * Choose a reasonable default.  All figures in sectors.
 289		 */
 290		if (min_region_size > (1 << 13)) {
 
 
 291			DMINFO("Choosing default region size of %lu sectors",
 292			       region_size);
 293			region_size = min_region_size;
 294		} else {
 295			DMINFO("Choosing default region size of 4MiB");
 296			region_size = 1 << 13; /* sectors */
 297		}
 298	} else {
 299		/*
 300		 * Validate user-supplied value.
 301		 */
 302		if (region_size > rs->ti->len) {
 303			rs->ti->error = "Supplied region size is too large";
 304			return -EINVAL;
 305		}
 306
 307		if (region_size < min_region_size) {
 308			DMERR("Supplied region_size (%lu sectors) below minimum (%lu)",
 309			      region_size, min_region_size);
 310			rs->ti->error = "Supplied region size is too small";
 311			return -EINVAL;
 312		}
 313
 314		if (!is_power_of_2(region_size)) {
 315			rs->ti->error = "Region size is not a power of 2";
 316			return -EINVAL;
 317		}
 318
 319		if (region_size < rs->md.chunk_sectors) {
 320			rs->ti->error = "Region size is smaller than the chunk size";
 321			return -EINVAL;
 322		}
 323	}
 324
 325	/*
 326	 * Convert sectors to bytes.
 327	 */
 328	rs->md.bitmap_info.chunksize = (region_size << 9);
 329
 330	return 0;
 331}
 332
 333/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 334 * Possible arguments are...
 335 *	<chunk_size> [optional_args]
 336 *
 337 * Argument definitions
 338 *    <chunk_size>			The number of sectors per disk that
 339 *                                      will form the "stripe"
 340 *    [[no]sync]			Force or prevent recovery of the
 341 *                                      entire array
 342 *    [rebuild <idx>]			Rebuild the drive indicated by the index
 343 *    [daemon_sleep <ms>]		Time between bitmap daemon work to
 344 *                                      clear bits
 345 *    [min_recovery_rate <kB/sec/disk>]	Throttle RAID initialization
 346 *    [max_recovery_rate <kB/sec/disk>]	Throttle RAID initialization
 347 *    [write_mostly <idx>]		Indicate a write mostly drive via index
 348 *    [max_write_behind <sectors>]	See '-write-behind=' (man mdadm)
 349 *    [stripe_cache <sectors>]		Stripe cache size for higher RAIDs
 350 *    [region_size <sectors>]           Defines granularity of bitmap
 
 
 
 
 351 */
 352static int parse_raid_params(struct raid_set *rs, char **argv,
 353			     unsigned num_raid_params)
 354{
 355	unsigned i, rebuild_cnt = 0;
 356	unsigned long value, region_size = 0;
 357	char *key;
 
 
 
 
 
 
 
 
 
 
 
 
 
 358
 359	/*
 360	 * First, parse the in-order required arguments
 361	 * "chunk_size" is the only argument of this type.
 362	 */
 363	if ((strict_strtoul(argv[0], 10, &value) < 0)) {
 364		rs->ti->error = "Bad chunk size";
 365		return -EINVAL;
 366	} else if (rs->raid_type->level == 1) {
 367		if (value)
 368			DMERR("Ignoring chunk size parameter for RAID 1");
 369		value = 0;
 370	} else if (!is_power_of_2(value)) {
 371		rs->ti->error = "Chunk size must be a power of 2";
 372		return -EINVAL;
 373	} else if (value < 8) {
 374		rs->ti->error = "Chunk size value is too small";
 375		return -EINVAL;
 376	}
 377
 378	rs->md.new_chunk_sectors = rs->md.chunk_sectors = value;
 379	argv++;
 380	num_raid_params--;
 381
 382	/*
 383	 * We set each individual device as In_sync with a completed
 384	 * 'recovery_offset'.  If there has been a device failure or
 385	 * replacement then one of the following cases applies:
 386	 *
 387	 *   1) User specifies 'rebuild'.
 388	 *      - Device is reset when param is read.
 389	 *   2) A new device is supplied.
 390	 *      - No matching superblock found, resets device.
 391	 *   3) Device failure was transient and returns on reload.
 392	 *      - Failure noticed, resets device for bitmap replay.
 393	 *   4) Device hadn't completed recovery after previous failure.
 394	 *      - Superblock is read and overrides recovery_offset.
 395	 *
 396	 * What is found in the superblocks of the devices is always
 397	 * authoritative, unless 'rebuild' or '[no]sync' was specified.
 398	 */
 399	for (i = 0; i < rs->md.raid_disks; i++) {
 400		set_bit(In_sync, &rs->dev[i].rdev.flags);
 401		rs->dev[i].rdev.recovery_offset = MaxSector;
 402	}
 403
 404	/*
 405	 * Second, parse the unordered optional arguments
 406	 */
 407	for (i = 0; i < num_raid_params; i++) {
 408		if (!strcasecmp(argv[i], "nosync")) {
 409			rs->md.recovery_cp = MaxSector;
 410			rs->print_flags |= DMPF_NOSYNC;
 
 
 
 
 
 
 
 
 411			continue;
 412		}
 413		if (!strcasecmp(argv[i], "sync")) {
 414			rs->md.recovery_cp = 0;
 415			rs->print_flags |= DMPF_SYNC;
 
 
 
 
 
 
 
 
 
 416			continue;
 417		}
 418
 419		/* The rest of the optional arguments come in key/value pairs */
 420		if ((i + 1) >= num_raid_params) {
 
 421			rs->ti->error = "Wrong number of raid parameters given";
 422			return -EINVAL;
 423		}
 424
 425		key = argv[i++];
 426		if (strict_strtoul(argv[i], 10, &value) < 0) {
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 427			rs->ti->error = "Bad numerical argument given in raid params";
 428			return -EINVAL;
 429		}
 430
 431		if (!strcasecmp(key, "rebuild")) {
 432			rebuild_cnt++;
 433			if (((rs->raid_type->level != 1) &&
 434			     (rebuild_cnt > rs->raid_type->parity_devs)) ||
 435			    ((rs->raid_type->level == 1) &&
 436			     (rebuild_cnt > (rs->md.raid_disks - 1)))) {
 437				rs->ti->error = "Too many rebuild devices specified for given RAID type";
 
 438				return -EINVAL;
 439			}
 440			if (value > rs->md.raid_disks) {
 441				rs->ti->error = "Invalid rebuild index given";
 
 442				return -EINVAL;
 443			}
 444			clear_bit(In_sync, &rs->dev[value].rdev.flags);
 445			rs->dev[value].rdev.recovery_offset = 0;
 446			rs->print_flags |= DMPF_REBUILD;
 447		} else if (!strcasecmp(key, "write_mostly")) {
 448			if (rs->raid_type->level != 1) {
 
 
 
 449				rs->ti->error = "write_mostly option is only valid for RAID1";
 450				return -EINVAL;
 451			}
 452			if (value >= rs->md.raid_disks) {
 453				rs->ti->error = "Invalid write_mostly drive index given";
 
 454				return -EINVAL;
 455			}
 
 
 456			set_bit(WriteMostly, &rs->dev[value].rdev.flags);
 457		} else if (!strcasecmp(key, "max_write_behind")) {
 458			if (rs->raid_type->level != 1) {
 
 459				rs->ti->error = "max_write_behind option is only valid for RAID1";
 460				return -EINVAL;
 461			}
 462			rs->print_flags |= DMPF_MAX_WRITE_BEHIND;
 
 
 
 
 463
 464			/*
 465			 * In device-mapper, we specify things in sectors, but
 466			 * MD records this value in kB
 467			 */
 468			value /= 2;
 469			if (value > COUNTER_MAX) {
 470				rs->ti->error = "Max write-behind limit out of range";
 471				return -EINVAL;
 472			}
 
 473			rs->md.bitmap_info.max_write_behind = value;
 474		} else if (!strcasecmp(key, "daemon_sleep")) {
 475			rs->print_flags |= DMPF_DAEMON_SLEEP;
 
 
 
 476			if (!value || (value > MAX_SCHEDULE_TIMEOUT)) {
 477				rs->ti->error = "daemon sleep period out of range";
 478				return -EINVAL;
 479			}
 480			rs->md.bitmap_info.daemon_sleep = value;
 481		} else if (!strcasecmp(key, "stripe_cache")) {
 482			rs->print_flags |= DMPF_STRIPE_CACHE;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 483
 484			/*
 485			 * In device-mapper, we specify things in sectors, but
 486			 * MD records this value in kB
 487			 */
 488			value /= 2;
 
 489
 490			if (rs->raid_type->level < 5) {
 491				rs->ti->error = "Inappropriate argument: stripe_cache";
 492				return -EINVAL;
 493			}
 494			if (raid5_set_cache_size(&rs->md, (int)value)) {
 495				rs->ti->error = "Bad stripe_cache size";
 
 
 
 496				return -EINVAL;
 497			}
 498		} else if (!strcasecmp(key, "min_recovery_rate")) {
 499			rs->print_flags |= DMPF_MIN_RECOVERY_RATE;
 500			if (value > INT_MAX) {
 501				rs->ti->error = "min_recovery_rate out of range";
 502				return -EINVAL;
 503			}
 504			rs->md.sync_speed_min = (int)value;
 505		} else if (!strcasecmp(key, "max_recovery_rate")) {
 506			rs->print_flags |= DMPF_MAX_RECOVERY_RATE;
 
 
 
 507			if (value > INT_MAX) {
 508				rs->ti->error = "max_recovery_rate out of range";
 509				return -EINVAL;
 510			}
 511			rs->md.sync_speed_max = (int)value;
 512		} else if (!strcasecmp(key, "region_size")) {
 513			rs->print_flags |= DMPF_REGION_SIZE;
 
 
 
 
 514			region_size = value;
 
 
 
 
 
 
 
 
 
 
 
 
 
 515		} else {
 516			DMERR("Unable to parse RAID parameter: %s", key);
 517			rs->ti->error = "Unable to parse RAID parameters";
 518			return -EINVAL;
 519		}
 520	}
 521
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 522	if (validate_region_size(rs, region_size))
 523		return -EINVAL;
 524
 525	if (rs->md.chunk_sectors)
 526		rs->ti->split_io = rs->md.chunk_sectors;
 527	else
 528		rs->ti->split_io = region_size;
 529
 530	if (rs->md.chunk_sectors)
 531		rs->ti->split_io = rs->md.chunk_sectors;
 532	else
 533		rs->ti->split_io = region_size;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 534
 535	/* Assume there are no metadata devices until the drives are parsed */
 536	rs->md.persistent = 0;
 537	rs->md.external = 1;
 538
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 539	return 0;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 540}
 541
 542static void do_table_event(struct work_struct *ws)
 543{
 544	struct raid_set *rs = container_of(ws, struct raid_set, md.event_work);
 545
 
 
 
 546	dm_table_event(rs->ti->table);
 547}
 548
 549static int raid_is_congested(struct dm_target_callbacks *cb, int bits)
 550{
 551	struct raid_set *rs = container_of(cb, struct raid_set, callbacks);
 552
 553	if (rs->raid_type->level == 1)
 554		return md_raid1_congested(&rs->md, bits);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 555
 556	return md_raid5_congested(&rs->md, bits);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 557}
 558
 
 
 
 
 
 
 
 559/*
 560 * This structure is never routinely used by userspace, unlike md superblocks.
 561 * Devices with this superblock should only ever be accessed via device-mapper.
 562 */
 563#define DM_RAID_MAGIC 0x64526D44
 564struct dm_raid_superblock {
 565	__le32 magic;		/* "DmRd" */
 566	__le32 features;	/* Used to indicate possible future changes */
 567
 568	__le32 num_devices;	/* Number of devices in this array. (Max 64) */
 569	__le32 array_position;	/* The position of this drive in the array */
 570
 571	__le64 events;		/* Incremented by md when superblock updated */
 572	__le64 failed_devices;	/* Bit field of devices to indicate failures */
 
 573
 574	/*
 575	 * This offset tracks the progress of the repair or replacement of
 576	 * an individual drive.
 577	 */
 578	__le64 disk_recovery_offset;
 579
 580	/*
 581	 * This offset tracks the progress of the initial array
 582	 * synchronisation/parity calculation.
 583	 */
 584	__le64 array_resync_offset;
 585
 586	/*
 587	 * RAID characteristics
 588	 */
 589	__le32 level;
 590	__le32 layout;
 591	__le32 stripe_sectors;
 592
 593	__u8 pad[452];		/* Round struct to 512 bytes. */
 594				/* Always set to 0 when writing. */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 595} __packed;
 596
 597static int read_disk_sb(mdk_rdev_t *rdev, int size)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 598{
 599	BUG_ON(!rdev->sb_page);
 600
 601	if (rdev->sb_loaded)
 602		return 0;
 603
 604	if (!sync_page_io(rdev, 0, size, rdev->sb_page, READ, 1)) {
 605		DMERR("Failed to read device superblock");
 
 
 606		return -EINVAL;
 607	}
 608
 609	rdev->sb_loaded = 1;
 610
 611	return 0;
 612}
 613
 614static void super_sync(mddev_t *mddev, mdk_rdev_t *rdev)
 615{
 616	mdk_rdev_t *r, *t;
 617	uint64_t failed_devices;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 618	struct dm_raid_superblock *sb;
 
 
 
 
 
 
 
 619
 620	sb = page_address(rdev->sb_page);
 621	failed_devices = le64_to_cpu(sb->failed_devices);
 622
 623	rdev_for_each(r, t, mddev)
 624		if ((r->raid_disk >= 0) && test_bit(Faulty, &r->flags))
 625			failed_devices |= (1ULL << r->raid_disk);
 
 
 
 
 626
 627	memset(sb, 0, sizeof(*sb));
 
 628
 629	sb->magic = cpu_to_le32(DM_RAID_MAGIC);
 630	sb->features = cpu_to_le32(0);	/* No features yet */
 631
 632	sb->num_devices = cpu_to_le32(mddev->raid_disks);
 633	sb->array_position = cpu_to_le32(rdev->raid_disk);
 634
 635	sb->events = cpu_to_le64(mddev->events);
 636	sb->failed_devices = cpu_to_le64(failed_devices);
 637
 638	sb->disk_recovery_offset = cpu_to_le64(rdev->recovery_offset);
 639	sb->array_resync_offset = cpu_to_le64(mddev->recovery_cp);
 640
 641	sb->level = cpu_to_le32(mddev->level);
 642	sb->layout = cpu_to_le32(mddev->layout);
 643	sb->stripe_sectors = cpu_to_le32(mddev->chunk_sectors);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 644}
 645
 646/*
 647 * super_load
 648 *
 649 * This function creates a superblock if one is not found on the device
 650 * and will decide which superblock to use if there's a choice.
 651 *
 652 * Return: 1 if use rdev, 0 if use refdev, -Exxx otherwise
 653 */
 654static int super_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev)
 655{
 656	int ret;
 657	struct dm_raid_superblock *sb;
 658	struct dm_raid_superblock *refsb;
 659	uint64_t events_sb, events_refsb;
 660
 661	rdev->sb_start = 0;
 662	rdev->sb_size = sizeof(*sb);
 
 
 
 
 663
 664	ret = read_disk_sb(rdev, rdev->sb_size);
 665	if (ret)
 666		return ret;
 667
 668	sb = page_address(rdev->sb_page);
 669	if (sb->magic != cpu_to_le32(DM_RAID_MAGIC)) {
 
 
 
 
 
 
 
 670		super_sync(rdev->mddev, rdev);
 671
 672		set_bit(FirstUse, &rdev->flags);
 
 673
 674		/* Force writing of superblocks to disk */
 675		set_bit(MD_CHANGE_DEVS, &rdev->mddev->flags);
 676
 677		/* Any superblock is better than none, choose that if given */
 678		return refdev ? 0 : 1;
 679	}
 680
 681	if (!refdev)
 682		return 1;
 683
 684	events_sb = le64_to_cpu(sb->events);
 685
 686	refsb = page_address(refdev->sb_page);
 687	events_refsb = le64_to_cpu(refsb->events);
 688
 689	return (events_sb > events_refsb) ? 1 : 0;
 690}
 691
 692static int super_init_validation(mddev_t *mddev, mdk_rdev_t *rdev)
 693{
 694	int role;
 695	struct raid_set *rs = container_of(mddev, struct raid_set, md);
 
 696	uint64_t events_sb;
 697	uint64_t failed_devices;
 698	struct dm_raid_superblock *sb;
 699	uint32_t new_devs = 0;
 700	uint32_t rebuilds = 0;
 701	mdk_rdev_t *r, *t;
 702	struct dm_raid_superblock *sb2;
 703
 704	sb = page_address(rdev->sb_page);
 705	events_sb = le64_to_cpu(sb->events);
 706	failed_devices = le64_to_cpu(sb->failed_devices);
 707
 708	/*
 709	 * Initialise to 1 if this is a new superblock.
 710	 */
 711	mddev->events = events_sb ? : 1;
 712
 
 
 
 
 
 
 
 713	/*
 714	 * Reshaping is not currently allowed
 
 715	 */
 716	if ((le32_to_cpu(sb->level) != mddev->level) ||
 717	    (le32_to_cpu(sb->layout) != mddev->layout) ||
 718	    (le32_to_cpu(sb->stripe_sectors) != mddev->chunk_sectors)) {
 719		DMERR("Reshaping arrays not yet supported.");
 720		return -EINVAL;
 721	}
 
 
 
 
 
 
 
 
 722
 723	/* We can only change the number of devices in RAID1 right now */
 724	if ((rs->raid_type->level != 1) &&
 725	    (le32_to_cpu(sb->num_devices) != mddev->raid_disks)) {
 726		DMERR("Reshaping arrays not yet supported.");
 727		return -EINVAL;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 728	}
 729
 730	if (!(rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC)))
 731		mddev->recovery_cp = le64_to_cpu(sb->array_resync_offset);
 732
 733	/*
 734	 * During load, we set FirstUse if a new superblock was written.
 735	 * There are two reasons we might not have a superblock:
 736	 * 1) The array is brand new - in which case, all of the
 737	 *    devices must have their In_sync bit set.  Also,
 738	 *    recovery_cp must be 0, unless forced.
 739	 * 2) This is a new device being added to an old array
 740	 *    and the new device needs to be rebuilt - in which
 741	 *    case the In_sync bit will /not/ be set and
 742	 *    recovery_cp must be MaxSector.
 
 
 
 
 743	 */
 744	rdev_for_each(r, t, mddev) {
 
 
 
 
 745		if (!test_bit(In_sync, &r->flags)) {
 746			if (!test_bit(FirstUse, &r->flags))
 747				DMERR("Superblock area of "
 748				      "rebuild device %d should have been "
 749				      "cleared.", r->raid_disk);
 750			set_bit(FirstUse, &r->flags);
 751			rebuilds++;
 752		} else if (test_bit(FirstUse, &r->flags))
 753			new_devs++;
 
 
 
 
 754	}
 755
 756	if (!rebuilds) {
 757		if (new_devs == mddev->raid_disks) {
 758			DMINFO("Superblocks created for new array");
 
 
 
 759			set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
 760		} else if (new_devs) {
 761			DMERR("New device injected "
 762			      "into existing array without 'rebuild' "
 763			      "parameter specified");
 764			return -EINVAL;
 765		}
 766	} else if (new_devs) {
 767		DMERR("'rebuild' devices cannot be "
 768		      "injected into an array with other first-time devices");
 769		return -EINVAL;
 770	} else if (mddev->recovery_cp != MaxSector) {
 771		DMERR("'rebuild' specified while array is not in-sync");
 772		return -EINVAL;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 773	}
 774
 775	/*
 776	 * Now we set the Faulty bit for those devices that are
 777	 * recorded in the superblock as failed.
 778	 */
 779	rdev_for_each(r, t, mddev) {
 
 780		if (!r->sb_page)
 781			continue;
 782		sb2 = page_address(r->sb_page);
 783		sb2->failed_devices = 0;
 
 784
 785		/*
 786		 * Check for any device re-ordering.
 787		 */
 788		if (!test_bit(FirstUse, &r->flags) && (r->raid_disk >= 0)) {
 789			role = le32_to_cpu(sb2->array_position);
 
 
 
 790			if (role != r->raid_disk) {
 791				if (rs->raid_type->level != 1) {
 792					rs->ti->error = "Cannot change device "
 793						"positions in RAID array";
 
 
 
 
 
 
 
 
 
 
 
 794					return -EINVAL;
 795				}
 796				DMINFO("RAID1 device #%d now at position #%d",
 797				       role, r->raid_disk);
 798			}
 799
 800			/*
 801			 * Partial recovery is performed on
 802			 * returning failed devices.
 803			 */
 804			if (failed_devices & (1 << role))
 805				set_bit(Faulty, &r->flags);
 806		}
 807	}
 808
 809	return 0;
 810}
 811
 812static int super_validate(mddev_t *mddev, mdk_rdev_t *rdev)
 813{
 814	struct dm_raid_superblock *sb = page_address(rdev->sb_page);
 
 
 
 
 
 
 815
 816	/*
 817	 * If mddev->events is not set, we know we have not yet initialized
 818	 * the array.
 819	 */
 820	if (!mddev->events && super_init_validation(mddev, rdev))
 
 
 
 
 
 821		return -EINVAL;
 
 822
 823	mddev->bitmap_info.offset = 4096 >> 9; /* Enable bitmap creation */
 824	rdev->mddev->bitmap_info.default_offset = 4096 >> 9;
 825	if (!test_bit(FirstUse, &rdev->flags)) {
 
 
 
 
 
 
 
 
 
 826		rdev->recovery_offset = le64_to_cpu(sb->disk_recovery_offset);
 827		if (rdev->recovery_offset != MaxSector)
 828			clear_bit(In_sync, &rdev->flags);
 
 
 
 
 
 
 829	}
 830
 831	/*
 832	 * If a device comes back, set it as not In_sync and no longer faulty.
 833	 */
 834	if (test_bit(Faulty, &rdev->flags)) {
 835		clear_bit(Faulty, &rdev->flags);
 836		clear_bit(In_sync, &rdev->flags);
 837		rdev->saved_raid_disk = rdev->raid_disk;
 838		rdev->recovery_offset = 0;
 839	}
 840
 841	clear_bit(FirstUse, &rdev->flags);
 
 
 842
 843	return 0;
 844}
 845
 846/*
 847 * Analyse superblocks and select the freshest.
 848 */
 849static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
 850{
 851	int ret;
 852	mdk_rdev_t *rdev, *freshest, *tmp;
 853	mddev_t *mddev = &rs->md;
 
 854
 855	freshest = NULL;
 856	rdev_for_each(rdev, tmp, mddev) {
 
 
 
 
 
 
 
 
 
 
 
 
 
 857		if (!rdev->meta_bdev)
 858			continue;
 859
 860		ret = super_load(rdev, freshest);
 861
 862		switch (ret) {
 863		case 1:
 864			freshest = rdev;
 865			break;
 866		case 0:
 867			break;
 868		default:
 869			ti->error = "Failed to load superblock";
 870			return ret;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 871		}
 872	}
 873
 874	if (!freshest)
 875		return 0;
 876
 
 
 
 
 
 877	/*
 878	 * Validation of the freshest device provides the source of
 879	 * validation for the remaining devices.
 880	 */
 881	ti->error = "Unable to assemble array: Invalid superblocks";
 882	if (super_validate(mddev, freshest))
 883		return -EINVAL;
 884
 885	rdev_for_each(rdev, tmp, mddev)
 886		if ((rdev != freshest) && super_validate(mddev, rdev))
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 887			return -EINVAL;
 888
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 889	return 0;
 890}
 891
 892/*
 893 * Construct a RAID4/5/6 mapping:
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 894 * Args:
 895 *	<raid_type> <#raid_params> <raid_params>		\
 896 *	<#raid_devs> { <meta_dev1> <dev1> .. <meta_devN> <devN> }
 897 *
 898 * <raid_params> varies by <raid_type>.  See 'parse_raid_params' for
 899 * details on possible <raid_params>.
 
 
 
 
 900 */
 901static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
 902{
 903	int ret;
 
 904	struct raid_type *rt;
 905	unsigned long num_raid_params, num_raid_devs;
 
 906	struct raid_set *rs = NULL;
 907
 908	/* Must have at least <raid_type> <#raid_params> */
 909	if (argc < 2) {
 910		ti->error = "Too few arguments";
 
 
 
 
 
 
 
 
 911		return -EINVAL;
 912	}
 913
 914	/* raid type */
 915	rt = get_raid_type(argv[0]);
 916	if (!rt) {
 917		ti->error = "Unrecognised raid_type";
 918		return -EINVAL;
 919	}
 920	argc--;
 921	argv++;
 922
 923	/* number of RAID parameters */
 924	if (strict_strtoul(argv[0], 10, &num_raid_params) < 0) {
 925		ti->error = "Cannot understand number of RAID parameters";
 926		return -EINVAL;
 927	}
 928	argc--;
 929	argv++;
 930
 931	/* Skip over RAID params for now and find out # of devices */
 932	if (num_raid_params + 1 > argc) {
 933		ti->error = "Arguments do not agree with counts given";
 
 
 934		return -EINVAL;
 935	}
 936
 937	if ((strict_strtoul(argv[num_raid_params], 10, &num_raid_devs) < 0) ||
 938	    (num_raid_devs >= INT_MAX)) {
 939		ti->error = "Cannot understand number of raid devices";
 940		return -EINVAL;
 941	}
 942
 943	rs = context_alloc(ti, rt, (unsigned)num_raid_devs);
 944	if (IS_ERR(rs))
 945		return PTR_ERR(rs);
 946
 947	ret = parse_raid_params(rs, argv, (unsigned)num_raid_params);
 948	if (ret)
 949		goto bad;
 950
 951	ret = -EINVAL;
 
 
 952
 953	argc -= num_raid_params + 1; /* +1: we already have num_raid_devs */
 954	argv += num_raid_params + 1;
 955
 956	if (argc != (num_raid_devs * 2)) {
 957		ti->error = "Supplied RAID devices does not match the count given";
 
 
 
 
 
 
 958		goto bad;
 959	}
 960
 961	ret = dev_parms(rs, argv);
 962	if (ret)
 963		goto bad;
 964
 965	rs->md.sync_super = super_sync;
 966	ret = analyse_superblocks(ti, rs);
 967	if (ret)
 
 
 
 
 
 
 968		goto bad;
 969
 
 
 970	INIT_WORK(&rs->md.event_work, do_table_event);
 971	ti->private = rs;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 972
 973	mutex_lock(&rs->md.reconfig_mutex);
 974	ret = md_run(&rs->md);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 975	rs->md.in_sync = 0; /* Assume already marked dirty */
 976	mutex_unlock(&rs->md.reconfig_mutex);
 977
 978	if (ret) {
 979		ti->error = "Fail to run raid array";
 
 980		goto bad;
 981	}
 982
 983	rs->callbacks.congested_fn = raid_is_congested;
 984	dm_table_add_target_callbacks(ti->table, &rs->callbacks);
 985
 986	mddev_suspend(&rs->md);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 987	return 0;
 988
 
 
 
 989bad:
 990	context_free(rs);
 991
 992	return ret;
 993}
 994
 995static void raid_dtr(struct dm_target *ti)
 996{
 997	struct raid_set *rs = ti->private;
 998
 999	list_del_init(&rs->callbacks.list);
1000	md_stop(&rs->md);
1001	context_free(rs);
1002}
1003
1004static int raid_map(struct dm_target *ti, struct bio *bio, union map_info *map_context)
1005{
1006	struct raid_set *rs = ti->private;
1007	mddev_t *mddev = &rs->md;
 
 
 
 
 
 
 
 
 
 
 
1008
1009	mddev->pers->make_request(mddev, bio);
1010
1011	return DM_MAPIO_SUBMITTED;
1012}
1013
1014static int raid_status(struct dm_target *ti, status_type_t type,
1015		       char *result, unsigned maxlen)
1016{
1017	struct raid_set *rs = ti->private;
1018	unsigned raid_param_cnt = 1; /* at least 1 for chunksize */
1019	unsigned sz = 0;
1020	int i;
1021	sector_t sync;
1022
1023	switch (type) {
1024	case STATUSTYPE_INFO:
1025		DMEMIT("%s %d ", rs->raid_type->name, rs->md.raid_disks);
 
1026
1027		for (i = 0; i < rs->md.raid_disks; i++) {
1028			if (test_bit(Faulty, &rs->dev[i].rdev.flags))
1029				DMEMIT("D");
1030			else if (test_bit(In_sync, &rs->dev[i].rdev.flags))
1031				DMEMIT("A");
1032			else
1033				DMEMIT("a");
1034		}
1035
1036		if (test_bit(MD_RECOVERY_RUNNING, &rs->md.recovery))
1037			sync = rs->md.curr_resync_completed;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1038		else
1039			sync = rs->md.recovery_cp;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1040
1041		if (sync > rs->md.resync_max_sectors)
1042			sync = rs->md.resync_max_sectors;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1043
1044		DMEMIT(" %llu/%llu",
1045		       (unsigned long long) sync,
1046		       (unsigned long long) rs->md.resync_max_sectors);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1047
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1048		break;
 
1049	case STATUSTYPE_TABLE:
1050		/* The string you would use to construct this array */
1051		for (i = 0; i < rs->md.raid_disks; i++) {
1052			if ((rs->print_flags & DMPF_REBUILD) &&
1053			    rs->dev[i].data_dev &&
1054			    !test_bit(In_sync, &rs->dev[i].rdev.flags))
1055				raid_param_cnt += 2; /* for rebuilds */
1056			if (rs->dev[i].data_dev &&
1057			    test_bit(WriteMostly, &rs->dev[i].rdev.flags))
1058				raid_param_cnt += 2;
1059		}
1060
1061		raid_param_cnt += (hweight64(rs->print_flags & ~DMPF_REBUILD) * 2);
1062		if (rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC))
1063			raid_param_cnt--;
1064
1065		DMEMIT("%s %u %u", rs->raid_type->name,
1066		       raid_param_cnt, rs->md.chunk_sectors);
1067
1068		if ((rs->print_flags & DMPF_SYNC) &&
1069		    (rs->md.recovery_cp == MaxSector))
1070			DMEMIT(" sync");
1071		if (rs->print_flags & DMPF_NOSYNC)
1072			DMEMIT(" nosync");
1073
1074		for (i = 0; i < rs->md.raid_disks; i++)
1075			if ((rs->print_flags & DMPF_REBUILD) &&
1076			    rs->dev[i].data_dev &&
1077			    !test_bit(In_sync, &rs->dev[i].rdev.flags))
1078				DMEMIT(" rebuild %u", i);
1079
1080		if (rs->print_flags & DMPF_DAEMON_SLEEP)
1081			DMEMIT(" daemon_sleep %lu",
1082			       rs->md.bitmap_info.daemon_sleep);
1083
1084		if (rs->print_flags & DMPF_MIN_RECOVERY_RATE)
1085			DMEMIT(" min_recovery_rate %d", rs->md.sync_speed_min);
1086
1087		if (rs->print_flags & DMPF_MAX_RECOVERY_RATE)
1088			DMEMIT(" max_recovery_rate %d", rs->md.sync_speed_max);
1089
1090		for (i = 0; i < rs->md.raid_disks; i++)
1091			if (rs->dev[i].data_dev &&
1092			    test_bit(WriteMostly, &rs->dev[i].rdev.flags))
1093				DMEMIT(" write_mostly %u", i);
1094
1095		if (rs->print_flags & DMPF_MAX_WRITE_BEHIND)
1096			DMEMIT(" max_write_behind %lu",
1097			       rs->md.bitmap_info.max_write_behind);
1098
1099		if (rs->print_flags & DMPF_STRIPE_CACHE) {
1100			raid5_conf_t *conf = rs->md.private;
1101
1102			/* convert from kiB to sectors */
1103			DMEMIT(" stripe_cache %d",
1104			       conf ? conf->max_nr_stripes * 2 : 0);
1105		}
1106
1107		if (rs->print_flags & DMPF_REGION_SIZE)
1108			DMEMIT(" region_size %lu",
1109			       rs->md.bitmap_info.chunksize >> 9);
1110
1111		DMEMIT(" %d", rs->md.raid_disks);
1112		for (i = 0; i < rs->md.raid_disks; i++) {
1113			if (rs->dev[i].meta_dev)
1114				DMEMIT(" %s", rs->dev[i].meta_dev->name);
1115			else
1116				DMEMIT(" -");
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1117
1118			if (rs->dev[i].data_dev)
1119				DMEMIT(" %s", rs->dev[i].data_dev->name);
1120			else
1121				DMEMIT(" -");
1122		}
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1123	}
 
 
 
 
 
 
 
 
 
 
 
1124
1125	return 0;
1126}
1127
1128static int raid_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data)
 
1129{
1130	struct raid_set *rs = ti->private;
1131	unsigned i;
1132	int ret = 0;
1133
1134	for (i = 0; !ret && i < rs->md.raid_disks; i++)
1135		if (rs->dev[i].data_dev)
1136			ret = fn(ti,
1137				 rs->dev[i].data_dev,
1138				 0, /* No offset on data devs */
1139				 rs->md.dev_sectors,
1140				 data);
1141
1142	return ret;
1143}
1144
1145static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
1146{
1147	struct raid_set *rs = ti->private;
1148	unsigned chunk_size = rs->md.chunk_sectors << 9;
1149	raid5_conf_t *conf = rs->md.private;
1150
1151	blk_limits_io_min(limits, chunk_size);
1152	blk_limits_io_opt(limits, chunk_size * (conf->raid_disks - conf->max_degraded));
1153}
1154
1155static void raid_presuspend(struct dm_target *ti)
1156{
1157	struct raid_set *rs = ti->private;
1158
1159	md_stop_writes(&rs->md);
1160}
1161
1162static void raid_postsuspend(struct dm_target *ti)
1163{
1164	struct raid_set *rs = ti->private;
1165
1166	mddev_suspend(&rs->md);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1167}
1168
 
 
1169static void raid_resume(struct dm_target *ti)
1170{
1171	struct raid_set *rs = ti->private;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
1172
1173	bitmap_load(&rs->md);
1174	mddev_resume(&rs->md);
1175}
1176
1177static struct target_type raid_target = {
1178	.name = "raid",
1179	.version = {1, 1, 0},
1180	.module = THIS_MODULE,
1181	.ctr = raid_ctr,
1182	.dtr = raid_dtr,
1183	.map = raid_map,
1184	.status = raid_status,
 
1185	.iterate_devices = raid_iterate_devices,
1186	.io_hints = raid_io_hints,
1187	.presuspend = raid_presuspend,
1188	.postsuspend = raid_postsuspend,
 
1189	.resume = raid_resume,
1190};
1191
1192static int __init dm_raid_init(void)
1193{
 
 
 
 
1194	return dm_register_target(&raid_target);
1195}
1196
1197static void __exit dm_raid_exit(void)
1198{
1199	dm_unregister_target(&raid_target);
1200}
1201
1202module_init(dm_raid_init);
1203module_exit(dm_raid_exit);
1204
1205MODULE_DESCRIPTION(DM_NAME " raid4/5/6 target");
 
 
 
 
 
 
 
1206MODULE_ALIAS("dm-raid4");
1207MODULE_ALIAS("dm-raid5");
1208MODULE_ALIAS("dm-raid6");
1209MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>");
 
1210MODULE_LICENSE("GPL");
v4.10.11
   1/*
   2 * Copyright (C) 2010-2011 Neil Brown
   3 * Copyright (C) 2010-2016 Red Hat, Inc. All rights reserved.
   4 *
   5 * This file is released under the GPL.
   6 */
   7
   8#include <linux/slab.h>
   9#include <linux/module.h>
  10
  11#include "md.h"
  12#include "raid1.h"
  13#include "raid5.h"
  14#include "raid10.h"
  15#include "bitmap.h"
  16
  17#include <linux/device-mapper.h>
  18
  19#define DM_MSG_PREFIX "raid"
  20#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
  27static bool devices_handle_discard_safely = false;
  28
  29/*
  30 * The following flags are used by dm-raid.c to set up the array state.
  31 * They must be cleared before md_run is called.
  32 */
  33#define FirstUse 10		/* rdev flag */
  34
  35struct raid_dev {
  36	/*
  37	 * Two DM devices, one to hold metadata and one to hold the
  38	 * actual data/parity.	The reason for this is to not confuse
  39	 * ti->len and give more flexibility in altering size and
  40	 * characteristics.
  41	 *
  42	 * While it is possible for this device to be associated
  43	 * with a different physical device than the data_dev, it
  44	 * is intended for it to be the same.
  45	 *    |--------- Physical Device ---------|
  46	 *    |- meta_dev -|------ data_dev ------|
  47	 */
  48	struct dm_dev *meta_dev;
  49	struct dm_dev *data_dev;
  50	struct md_rdev rdev;
  51};
  52
  53/*
  54 * Bits for establishing rs->ctr_flags
  55 *
  56 * 1 = no flag value
  57 * 2 = flag with value
  58 */
  59#define __CTR_FLAG_SYNC			0  /* 1 */ /* Not with raid0! */
  60#define __CTR_FLAG_NOSYNC		1  /* 1 */ /* Not with raid0! */
  61#define __CTR_FLAG_REBUILD		2  /* 2 */ /* Not with raid0! */
  62#define __CTR_FLAG_DAEMON_SLEEP		3  /* 2 */ /* Not with raid0! */
  63#define __CTR_FLAG_MIN_RECOVERY_RATE	4  /* 2 */ /* Not with raid0! */
  64#define __CTR_FLAG_MAX_RECOVERY_RATE	5  /* 2 */ /* Not with raid0! */
  65#define __CTR_FLAG_MAX_WRITE_BEHIND	6  /* 2 */ /* Only with raid1! */
  66#define __CTR_FLAG_WRITE_MOSTLY		7  /* 2 */ /* Only with raid1! */
  67#define __CTR_FLAG_STRIPE_CACHE		8  /* 2 */ /* Only with raid4/5/6! */
  68#define __CTR_FLAG_REGION_SIZE		9  /* 2 */ /* Not with raid0! */
  69#define __CTR_FLAG_RAID10_COPIES	10 /* 2 */ /* Only with raid10 */
  70#define __CTR_FLAG_RAID10_FORMAT	11 /* 2 */ /* Only with raid10 */
  71/* New for v1.9.0 */
  72#define __CTR_FLAG_DELTA_DISKS		12 /* 2 */ /* Only with reshapable raid1/4/5/6/10! */
  73#define __CTR_FLAG_DATA_OFFSET		13 /* 2 */ /* Only with reshapable raid4/5/6/10! */
  74#define __CTR_FLAG_RAID10_USE_NEAR_SETS 14 /* 2 */ /* Only with raid10! */
  75
  76/*
  77 * Flags for rs->ctr_flags field.
  78 */
  79#define CTR_FLAG_SYNC			(1 << __CTR_FLAG_SYNC)
  80#define CTR_FLAG_NOSYNC			(1 << __CTR_FLAG_NOSYNC)
  81#define CTR_FLAG_REBUILD		(1 << __CTR_FLAG_REBUILD)
  82#define CTR_FLAG_DAEMON_SLEEP		(1 << __CTR_FLAG_DAEMON_SLEEP)
  83#define CTR_FLAG_MIN_RECOVERY_RATE	(1 << __CTR_FLAG_MIN_RECOVERY_RATE)
  84#define CTR_FLAG_MAX_RECOVERY_RATE	(1 << __CTR_FLAG_MAX_RECOVERY_RATE)
  85#define CTR_FLAG_MAX_WRITE_BEHIND	(1 << __CTR_FLAG_MAX_WRITE_BEHIND)
  86#define CTR_FLAG_WRITE_MOSTLY		(1 << __CTR_FLAG_WRITE_MOSTLY)
  87#define CTR_FLAG_STRIPE_CACHE		(1 << __CTR_FLAG_STRIPE_CACHE)
  88#define CTR_FLAG_REGION_SIZE		(1 << __CTR_FLAG_REGION_SIZE)
  89#define CTR_FLAG_RAID10_COPIES		(1 << __CTR_FLAG_RAID10_COPIES)
  90#define CTR_FLAG_RAID10_FORMAT		(1 << __CTR_FLAG_RAID10_FORMAT)
  91#define CTR_FLAG_DELTA_DISKS		(1 << __CTR_FLAG_DELTA_DISKS)
  92#define CTR_FLAG_DATA_OFFSET		(1 << __CTR_FLAG_DATA_OFFSET)
  93#define CTR_FLAG_RAID10_USE_NEAR_SETS	(1 << __CTR_FLAG_RAID10_USE_NEAR_SETS)
  94
  95/*
  96 * Definitions of various constructor flags to
  97 * be used in checks of valid / invalid flags
  98 * per raid level.
  99 */
 100/* Define all any sync flags */
 101#define	CTR_FLAGS_ANY_SYNC		(CTR_FLAG_SYNC | CTR_FLAG_NOSYNC)
 102
 103/* Define flags for options without argument (e.g. 'nosync') */
 104#define	CTR_FLAG_OPTIONS_NO_ARGS	(CTR_FLAGS_ANY_SYNC | \
 105					 CTR_FLAG_RAID10_USE_NEAR_SETS)
 106
 107/* Define flags for options with one argument (e.g. 'delta_disks +2') */
 108#define CTR_FLAG_OPTIONS_ONE_ARG (CTR_FLAG_REBUILD | \
 109				  CTR_FLAG_WRITE_MOSTLY | \
 110				  CTR_FLAG_DAEMON_SLEEP | \
 111				  CTR_FLAG_MIN_RECOVERY_RATE | \
 112				  CTR_FLAG_MAX_RECOVERY_RATE | \
 113				  CTR_FLAG_MAX_WRITE_BEHIND | \
 114				  CTR_FLAG_STRIPE_CACHE | \
 115				  CTR_FLAG_REGION_SIZE | \
 116				  CTR_FLAG_RAID10_COPIES | \
 117				  CTR_FLAG_RAID10_FORMAT | \
 118				  CTR_FLAG_DELTA_DISKS | \
 119				  CTR_FLAG_DATA_OFFSET)
 120
 121/* Valid options definitions per raid level... */
 122
 123/* "raid0" does only accept data offset */
 124#define RAID0_VALID_FLAGS	(CTR_FLAG_DATA_OFFSET)
 125
 126/* "raid1" does not accept stripe cache, data offset, delta_disks or any raid10 options */
 127#define RAID1_VALID_FLAGS	(CTR_FLAGS_ANY_SYNC | \
 128				 CTR_FLAG_REBUILD | \
 129				 CTR_FLAG_WRITE_MOSTLY | \
 130				 CTR_FLAG_DAEMON_SLEEP | \
 131				 CTR_FLAG_MIN_RECOVERY_RATE | \
 132				 CTR_FLAG_MAX_RECOVERY_RATE | \
 133				 CTR_FLAG_MAX_WRITE_BEHIND | \
 134				 CTR_FLAG_REGION_SIZE | \
 135				 CTR_FLAG_DELTA_DISKS | \
 136				 CTR_FLAG_DATA_OFFSET)
 137
 138/* "raid10" does not accept any raid1 or stripe cache options */
 139#define RAID10_VALID_FLAGS	(CTR_FLAGS_ANY_SYNC | \
 140				 CTR_FLAG_REBUILD | \
 141				 CTR_FLAG_DAEMON_SLEEP | \
 142				 CTR_FLAG_MIN_RECOVERY_RATE | \
 143				 CTR_FLAG_MAX_RECOVERY_RATE | \
 144				 CTR_FLAG_REGION_SIZE | \
 145				 CTR_FLAG_RAID10_COPIES | \
 146				 CTR_FLAG_RAID10_FORMAT | \
 147				 CTR_FLAG_DELTA_DISKS | \
 148				 CTR_FLAG_DATA_OFFSET | \
 149				 CTR_FLAG_RAID10_USE_NEAR_SETS)
 150
 151/*
 152 * "raid4/5/6" do not accept any raid1 or raid10 specific options
 153 *
 154 * "raid6" does not accept "nosync", because it is not guaranteed
 155 * that both parity and q-syndrome are being written properly with
 156 * any writes
 157 */
 158#define RAID45_VALID_FLAGS	(CTR_FLAGS_ANY_SYNC | \
 159				 CTR_FLAG_REBUILD | \
 160				 CTR_FLAG_DAEMON_SLEEP | \
 161				 CTR_FLAG_MIN_RECOVERY_RATE | \
 162				 CTR_FLAG_MAX_RECOVERY_RATE | \
 163				 CTR_FLAG_STRIPE_CACHE | \
 164				 CTR_FLAG_REGION_SIZE | \
 165				 CTR_FLAG_DELTA_DISKS | \
 166				 CTR_FLAG_DATA_OFFSET)
 167
 168#define RAID6_VALID_FLAGS	(CTR_FLAG_SYNC | \
 169				 CTR_FLAG_REBUILD | \
 170				 CTR_FLAG_DAEMON_SLEEP | \
 171				 CTR_FLAG_MIN_RECOVERY_RATE | \
 172				 CTR_FLAG_MAX_RECOVERY_RATE | \
 173				 CTR_FLAG_STRIPE_CACHE | \
 174				 CTR_FLAG_REGION_SIZE | \
 175				 CTR_FLAG_DELTA_DISKS | \
 176				 CTR_FLAG_DATA_OFFSET)
 177/* ...valid options definitions per raid level */
 178
 179/*
 180 * Flags for rs->runtime_flags field
 181 * (RT_FLAG prefix meaning "runtime flag")
 182 *
 183 * These are all internal and used to define runtime state,
 184 * e.g. to prevent another resume from preresume processing
 185 * the raid set all over again.
 186 */
 187#define RT_FLAG_RS_PRERESUMED		0
 188#define RT_FLAG_RS_RESUMED		1
 189#define RT_FLAG_RS_BITMAP_LOADED	2
 190#define RT_FLAG_UPDATE_SBS		3
 191#define RT_FLAG_RESHAPE_RS		4
 192
 193/* Array elements of 64 bit needed for rebuild/failed disk bits */
 194#define DISKS_ARRAY_ELEMS ((MAX_RAID_DEVICES + (sizeof(uint64_t) * 8 - 1)) / sizeof(uint64_t) / 8)
 195
 196/*
 197 * raid set level, layout and chunk sectors backup/restore
 198 */
 199struct rs_layout {
 200	int new_level;
 201	int new_layout;
 202	int new_chunk_sectors;
 203};
 204
 205struct raid_set {
 206	struct dm_target *ti;
 207
 208	uint32_t bitmap_loaded;
 209	uint32_t stripe_cache_entries;
 210	unsigned long ctr_flags;
 211	unsigned long runtime_flags;
 212
 213	uint64_t rebuild_disks[DISKS_ARRAY_ELEMS];
 214
 215	int raid_disks;
 216	int delta_disks;
 217	int data_offset;
 218	int raid10_copies;
 219	int requested_bitmap_chunk_sectors;
 220
 221	struct mddev md;
 222	struct raid_type *raid_type;
 223	struct dm_target_callbacks callbacks;
 224
 225	struct raid_dev dev[0];
 226};
 227
 228static void rs_config_backup(struct raid_set *rs, struct rs_layout *l)
 229{
 230	struct mddev *mddev = &rs->md;
 231
 232	l->new_level = mddev->new_level;
 233	l->new_layout = mddev->new_layout;
 234	l->new_chunk_sectors = mddev->new_chunk_sectors;
 235}
 236
 237static void rs_config_restore(struct raid_set *rs, struct rs_layout *l)
 238{
 239	struct mddev *mddev = &rs->md;
 240
 241	mddev->new_level = l->new_level;
 242	mddev->new_layout = l->new_layout;
 243	mddev->new_chunk_sectors = l->new_chunk_sectors;
 244}
 245
 246/* raid10 algorithms (i.e. formats) */
 247#define	ALGORITHM_RAID10_DEFAULT	0
 248#define	ALGORITHM_RAID10_NEAR		1
 249#define	ALGORITHM_RAID10_OFFSET		2
 250#define	ALGORITHM_RAID10_FAR		3
 251
 252/* Supported raid types and properties. */
 253static struct raid_type {
 254	const char *name;		/* RAID algorithm. */
 255	const char *descr;		/* Descriptor text for logging. */
 256	const unsigned int parity_devs;	/* # of parity devices. */
 257	const unsigned int minimal_devs;/* minimal # of devices in set. */
 258	const unsigned int level;	/* RAID level. */
 259	const unsigned int algorithm;	/* RAID algorithm. */
 260} raid_types[] = {
 261	{"raid0",	  "raid0 (striping)",			    0, 2, 0,  0 /* NONE */},
 262	{"raid1",	  "raid1 (mirroring)",			    0, 2, 1,  0 /* NONE */},
 263	{"raid10_far",	  "raid10 far (striped mirrors)",	    0, 2, 10, ALGORITHM_RAID10_FAR},
 264	{"raid10_offset", "raid10 offset (striped mirrors)",	    0, 2, 10, ALGORITHM_RAID10_OFFSET},
 265	{"raid10_near",	  "raid10 near (striped mirrors)",	    0, 2, 10, ALGORITHM_RAID10_NEAR},
 266	{"raid10",	  "raid10 (striped mirrors)",		    0, 2, 10, ALGORITHM_RAID10_DEFAULT},
 267	{"raid4",	  "raid4 (dedicated first parity disk)",    1, 2, 5,  ALGORITHM_PARITY_0}, /* raid4 layout = raid5_0 */
 268	{"raid5_n",	  "raid5 (dedicated last parity disk)",	    1, 2, 5,  ALGORITHM_PARITY_N},
 269	{"raid5_ls",	  "raid5 (left symmetric)",		    1, 2, 5,  ALGORITHM_LEFT_SYMMETRIC},
 270	{"raid5_rs",	  "raid5 (right symmetric)",		    1, 2, 5,  ALGORITHM_RIGHT_SYMMETRIC},
 271	{"raid5_la",	  "raid5 (left asymmetric)",		    1, 2, 5,  ALGORITHM_LEFT_ASYMMETRIC},
 272	{"raid5_ra",	  "raid5 (right asymmetric)",		    1, 2, 5,  ALGORITHM_RIGHT_ASYMMETRIC},
 273	{"raid6_zr",	  "raid6 (zero restart)",		    2, 4, 6,  ALGORITHM_ROTATING_ZERO_RESTART},
 274	{"raid6_nr",	  "raid6 (N restart)",			    2, 4, 6,  ALGORITHM_ROTATING_N_RESTART},
 275	{"raid6_nc",	  "raid6 (N continue)",			    2, 4, 6,  ALGORITHM_ROTATING_N_CONTINUE},
 276	{"raid6_n_6",	  "raid6 (dedicated parity/Q n/6)",	    2, 4, 6,  ALGORITHM_PARITY_N_6},
 277	{"raid6_ls_6",	  "raid6 (left symmetric dedicated Q 6)",   2, 4, 6,  ALGORITHM_LEFT_SYMMETRIC_6},
 278	{"raid6_rs_6",	  "raid6 (right symmetric dedicated Q 6)",  2, 4, 6,  ALGORITHM_RIGHT_SYMMETRIC_6},
 279	{"raid6_la_6",	  "raid6 (left asymmetric dedicated Q 6)",  2, 4, 6,  ALGORITHM_LEFT_ASYMMETRIC_6},
 280	{"raid6_ra_6",	  "raid6 (right asymmetric dedicated Q 6)", 2, 4, 6,  ALGORITHM_RIGHT_ASYMMETRIC_6}
 281};
 282
 283/* True, if @v is in inclusive range [@min, @max] */
 284static bool __within_range(long v, long min, long max)
 285{
 286	return v >= min && v <= max;
 287}
 288
 289/* All table line arguments are defined here */
 290static struct arg_name_flag {
 291	const unsigned long flag;
 292	const char *name;
 293} __arg_name_flags[] = {
 294	{ CTR_FLAG_SYNC, "sync"},
 295	{ CTR_FLAG_NOSYNC, "nosync"},
 296	{ CTR_FLAG_REBUILD, "rebuild"},
 297	{ CTR_FLAG_DAEMON_SLEEP, "daemon_sleep"},
 298	{ CTR_FLAG_MIN_RECOVERY_RATE, "min_recovery_rate"},
 299	{ CTR_FLAG_MAX_RECOVERY_RATE, "max_recovery_rate"},
 300	{ CTR_FLAG_MAX_WRITE_BEHIND, "max_write_behind"},
 301	{ CTR_FLAG_WRITE_MOSTLY, "write_mostly"},
 302	{ CTR_FLAG_STRIPE_CACHE, "stripe_cache"},
 303	{ CTR_FLAG_REGION_SIZE, "region_size"},
 304	{ CTR_FLAG_RAID10_COPIES, "raid10_copies"},
 305	{ CTR_FLAG_RAID10_FORMAT, "raid10_format"},
 306	{ CTR_FLAG_DATA_OFFSET, "data_offset"},
 307	{ CTR_FLAG_DELTA_DISKS, "delta_disks"},
 308	{ CTR_FLAG_RAID10_USE_NEAR_SETS, "raid10_use_near_sets"},
 309};
 310
 311/* Return argument name string for given @flag */
 312static const char *dm_raid_arg_name_by_flag(const uint32_t flag)
 313{
 314	if (hweight32(flag) == 1) {
 315		struct arg_name_flag *anf = __arg_name_flags + ARRAY_SIZE(__arg_name_flags);
 316
 317		while (anf-- > __arg_name_flags)
 318			if (flag & anf->flag)
 319				return anf->name;
 320
 321	} else
 322		DMERR("%s called with more than one flag!", __func__);
 323
 324	return NULL;
 325}
 326
 327/*
 328 * Bool helpers to test for various raid levels of a raid set.
 329 * It's level as reported by the superblock rather than
 330 * the requested raid_type passed to the constructor.
 331 */
 332/* Return true, if raid set in @rs is raid0 */
 333static bool rs_is_raid0(struct raid_set *rs)
 334{
 335	return !rs->md.level;
 336}
 337
 338/* Return true, if raid set in @rs is raid1 */
 339static bool rs_is_raid1(struct raid_set *rs)
 340{
 341	return rs->md.level == 1;
 342}
 343
 344/* Return true, if raid set in @rs is raid10 */
 345static bool rs_is_raid10(struct raid_set *rs)
 346{
 347	return rs->md.level == 10;
 348}
 349
 350/* Return true, if raid set in @rs is level 6 */
 351static bool rs_is_raid6(struct raid_set *rs)
 352{
 353	return rs->md.level == 6;
 354}
 355
 356/* Return true, if raid set in @rs is level 4, 5 or 6 */
 357static bool rs_is_raid456(struct raid_set *rs)
 358{
 359	return __within_range(rs->md.level, 4, 6);
 360}
 361
 362/* Return true, if raid set in @rs is reshapable */
 363static bool __is_raid10_far(int layout);
 364static bool rs_is_reshapable(struct raid_set *rs)
 365{
 366	return rs_is_raid456(rs) ||
 367	       (rs_is_raid10(rs) && !__is_raid10_far(rs->md.new_layout));
 368}
 369
 370/* Return true, if raid set in @rs is recovering */
 371static bool rs_is_recovering(struct raid_set *rs)
 372{
 373	return rs->md.recovery_cp < rs->dev[0].rdev.sectors;
 374}
 375
 376/* Return true, if raid set in @rs is reshaping */
 377static bool rs_is_reshaping(struct raid_set *rs)
 378{
 379	return rs->md.reshape_position != MaxSector;
 380}
 381
 382/*
 383 * bool helpers to test for various raid levels of a raid type @rt
 384 */
 385
 386/* Return true, if raid type in @rt is raid0 */
 387static bool rt_is_raid0(struct raid_type *rt)
 388{
 389	return !rt->level;
 390}
 391
 392/* Return true, if raid type in @rt is raid1 */
 393static bool rt_is_raid1(struct raid_type *rt)
 394{
 395	return rt->level == 1;
 396}
 397
 398/* Return true, if raid type in @rt is raid10 */
 399static bool rt_is_raid10(struct raid_type *rt)
 400{
 401	return rt->level == 10;
 402}
 403
 404/* Return true, if raid type in @rt is raid4/5 */
 405static bool rt_is_raid45(struct raid_type *rt)
 406{
 407	return __within_range(rt->level, 4, 5);
 408}
 409
 410/* Return true, if raid type in @rt is raid6 */
 411static bool rt_is_raid6(struct raid_type *rt)
 412{
 413	return rt->level == 6;
 414}
 415
 416/* Return true, if raid type in @rt is raid4/5/6 */
 417static bool rt_is_raid456(struct raid_type *rt)
 418{
 419	return __within_range(rt->level, 4, 6);
 420}
 421/* END: raid level bools */
 422
 423/* Return valid ctr flags for the raid level of @rs */
 424static unsigned long __valid_flags(struct raid_set *rs)
 425{
 426	if (rt_is_raid0(rs->raid_type))
 427		return RAID0_VALID_FLAGS;
 428	else if (rt_is_raid1(rs->raid_type))
 429		return RAID1_VALID_FLAGS;
 430	else if (rt_is_raid10(rs->raid_type))
 431		return RAID10_VALID_FLAGS;
 432	else if (rt_is_raid45(rs->raid_type))
 433		return RAID45_VALID_FLAGS;
 434	else if (rt_is_raid6(rs->raid_type))
 435		return RAID6_VALID_FLAGS;
 436
 437	return 0;
 438}
 439
 440/*
 441 * Check for valid flags set on @rs
 442 *
 443 * Has to be called after parsing of the ctr flags!
 444 */
 445static int rs_check_for_valid_flags(struct raid_set *rs)
 446{
 447	if (rs->ctr_flags & ~__valid_flags(rs)) {
 448		rs->ti->error = "Invalid flags combination";
 449		return -EINVAL;
 450	}
 451
 452	return 0;
 453}
 454
 455/* MD raid10 bit definitions and helpers */
 456#define RAID10_OFFSET			(1 << 16) /* stripes with data copies area adjacent on devices */
 457#define RAID10_BROCKEN_USE_FAR_SETS	(1 << 17) /* Broken in raid10.c: use sets instead of whole stripe rotation */
 458#define RAID10_USE_FAR_SETS		(1 << 18) /* Use sets instead of whole stripe rotation */
 459#define RAID10_FAR_COPIES_SHIFT		8	  /* raid10 # far copies shift (2nd byte of layout) */
 460
 461/* Return md raid10 near copies for @layout */
 462static unsigned int __raid10_near_copies(int layout)
 463{
 464	return layout & 0xFF;
 465}
 466
 467/* Return md raid10 far copies for @layout */
 468static unsigned int __raid10_far_copies(int layout)
 469{
 470	return __raid10_near_copies(layout >> RAID10_FAR_COPIES_SHIFT);
 471}
 472
 473/* Return true if md raid10 offset for @layout */
 474static bool __is_raid10_offset(int layout)
 475{
 476	return !!(layout & RAID10_OFFSET);
 477}
 478
 479/* Return true if md raid10 near for @layout */
 480static bool __is_raid10_near(int layout)
 481{
 482	return !__is_raid10_offset(layout) && __raid10_near_copies(layout) > 1;
 483}
 484
 485/* Return true if md raid10 far for @layout */
 486static bool __is_raid10_far(int layout)
 487{
 488	return !__is_raid10_offset(layout) && __raid10_far_copies(layout) > 1;
 489}
 490
 491/* Return md raid10 layout string for @layout */
 492static const char *raid10_md_layout_to_format(int layout)
 493{
 494	/*
 495	 * Bit 16 stands for "offset"
 496	 * (i.e. adjacent stripes hold copies)
 497	 *
 498	 * Refer to MD's raid10.c for details
 499	 */
 500	if (__is_raid10_offset(layout))
 501		return "offset";
 502
 503	if (__raid10_near_copies(layout) > 1)
 504		return "near";
 505
 506	WARN_ON(__raid10_far_copies(layout) < 2);
 507
 508	return "far";
 509}
 510
 511/* Return md raid10 algorithm for @name */
 512static int raid10_name_to_format(const char *name)
 513{
 514	if (!strcasecmp(name, "near"))
 515		return ALGORITHM_RAID10_NEAR;
 516	else if (!strcasecmp(name, "offset"))
 517		return ALGORITHM_RAID10_OFFSET;
 518	else if (!strcasecmp(name, "far"))
 519		return ALGORITHM_RAID10_FAR;
 520
 521	return -EINVAL;
 522}
 523
 524/* Return md raid10 copies for @layout */
 525static unsigned int raid10_md_layout_to_copies(int layout)
 526{
 527	return max(__raid10_near_copies(layout), __raid10_far_copies(layout));
 528}
 529
 530/* Return md raid10 format id for @format string */
 531static int raid10_format_to_md_layout(struct raid_set *rs,
 532				      unsigned int algorithm,
 533				      unsigned int copies)
 534{
 535	unsigned int n = 1, f = 1, r = 0;
 536
 537	/*
 538	 * MD resilienece flaw:
 539	 *
 540	 * enabling use_far_sets for far/offset formats causes copies
 541	 * to be colocated on the same devs together with their origins!
 542	 *
 543	 * -> disable it for now in the definition above
 544	 */
 545	if (algorithm == ALGORITHM_RAID10_DEFAULT ||
 546	    algorithm == ALGORITHM_RAID10_NEAR)
 547		n = copies;
 548
 549	else if (algorithm == ALGORITHM_RAID10_OFFSET) {
 550		f = copies;
 551		r = RAID10_OFFSET;
 552		if (!test_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags))
 553			r |= RAID10_USE_FAR_SETS;
 554
 555	} else if (algorithm == ALGORITHM_RAID10_FAR) {
 556		f = copies;
 557		r = !RAID10_OFFSET;
 558		if (!test_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags))
 559			r |= RAID10_USE_FAR_SETS;
 560
 561	} else
 562		return -EINVAL;
 563
 564	return r | (f << RAID10_FAR_COPIES_SHIFT) | n;
 565}
 566/* END: MD raid10 bit definitions and helpers */
 567
 568/* Check for any of the raid10 algorithms */
 569static bool __got_raid10(struct raid_type *rtp, const int layout)
 570{
 571	if (rtp->level == 10) {
 572		switch (rtp->algorithm) {
 573		case ALGORITHM_RAID10_DEFAULT:
 574		case ALGORITHM_RAID10_NEAR:
 575			return __is_raid10_near(layout);
 576		case ALGORITHM_RAID10_OFFSET:
 577			return __is_raid10_offset(layout);
 578		case ALGORITHM_RAID10_FAR:
 579			return __is_raid10_far(layout);
 580		default:
 581			break;
 582		}
 583	}
 584
 585	return false;
 586}
 587
 588/* Return raid_type for @name */
 589static struct raid_type *get_raid_type(const char *name)
 590{
 591	struct raid_type *rtp = raid_types + ARRAY_SIZE(raid_types);
 592
 593	while (rtp-- > raid_types)
 594		if (!strcasecmp(rtp->name, name))
 595			return rtp;
 596
 597	return NULL;
 598}
 599
 600/* Return raid_type for @name based derived from @level and @layout */
 601static struct raid_type *get_raid_type_by_ll(const int level, const int layout)
 602{
 603	struct raid_type *rtp = raid_types + ARRAY_SIZE(raid_types);
 604
 605	while (rtp-- > raid_types) {
 606		/* RAID10 special checks based on @layout flags/properties */
 607		if (rtp->level == level &&
 608		    (__got_raid10(rtp, layout) || rtp->algorithm == layout))
 609			return rtp;
 610	}
 611
 612	return NULL;
 613}
 614
 615/*
 616 * Conditionally change bdev capacity of @rs
 617 * in case of a disk add/remove reshape
 618 */
 619static void rs_set_capacity(struct raid_set *rs)
 620{
 621	struct mddev *mddev = &rs->md;
 622	struct md_rdev *rdev;
 623	struct gendisk *gendisk = dm_disk(dm_table_get_md(rs->ti->table));
 624
 625	/*
 626	 * raid10 sets rdev->sector to the device size, which
 627	 * is unintended in case of out-of-place reshaping
 628	 */
 629	rdev_for_each(rdev, mddev)
 630		rdev->sectors = mddev->dev_sectors;
 631
 632	set_capacity(gendisk, mddev->array_sectors);
 633	revalidate_disk(gendisk);
 634}
 635
 636/*
 637 * Set the mddev properties in @rs to the current
 638 * ones retrieved from the freshest superblock
 639 */
 640static void rs_set_cur(struct raid_set *rs)
 641{
 642	struct mddev *mddev = &rs->md;
 643
 644	mddev->new_level = mddev->level;
 645	mddev->new_layout = mddev->layout;
 646	mddev->new_chunk_sectors = mddev->chunk_sectors;
 647}
 648
 649/*
 650 * Set the mddev properties in @rs to the new
 651 * ones requested by the ctr
 652 */
 653static void rs_set_new(struct raid_set *rs)
 654{
 655	struct mddev *mddev = &rs->md;
 656
 657	mddev->level = mddev->new_level;
 658	mddev->layout = mddev->new_layout;
 659	mddev->chunk_sectors = mddev->new_chunk_sectors;
 660	mddev->raid_disks = rs->raid_disks;
 661	mddev->delta_disks = 0;
 662}
 663
 664static struct raid_set *raid_set_alloc(struct dm_target *ti, struct raid_type *raid_type,
 665				       unsigned int raid_devs)
 666{
 667	unsigned int i;
 668	struct raid_set *rs;
 
 669
 670	if (raid_devs <= raid_type->parity_devs) {
 671		ti->error = "Insufficient number of devices";
 672		return ERR_PTR(-EINVAL);
 673	}
 674
 
 
 
 
 
 
 
 675	rs = kzalloc(sizeof(*rs) + raid_devs * sizeof(rs->dev[0]), GFP_KERNEL);
 676	if (!rs) {
 677		ti->error = "Cannot allocate raid context";
 678		return ERR_PTR(-ENOMEM);
 679	}
 680
 681	mddev_init(&rs->md);
 682
 683	rs->raid_disks = raid_devs;
 684	rs->delta_disks = 0;
 685
 686	rs->ti = ti;
 687	rs->raid_type = raid_type;
 688	rs->stripe_cache_entries = 256;
 689	rs->md.raid_disks = raid_devs;
 690	rs->md.level = raid_type->level;
 691	rs->md.new_level = rs->md.level;
 
 692	rs->md.layout = raid_type->algorithm;
 693	rs->md.new_layout = rs->md.layout;
 694	rs->md.delta_disks = 0;
 695	rs->md.recovery_cp = MaxSector;
 696
 697	for (i = 0; i < raid_devs; i++)
 698		md_rdev_init(&rs->dev[i].rdev);
 699
 700	/*
 701	 * Remaining items to be initialized by further RAID params:
 702	 *  rs->md.persistent
 703	 *  rs->md.external
 704	 *  rs->md.chunk_sectors
 705	 *  rs->md.new_chunk_sectors
 706	 *  rs->md.dev_sectors
 707	 */
 708
 709	return rs;
 710}
 711
 712static void raid_set_free(struct raid_set *rs)
 713{
 714	int i;
 715
 716	for (i = 0; i < rs->raid_disks; i++) {
 717		if (rs->dev[i].meta_dev)
 718			dm_put_device(rs->ti, rs->dev[i].meta_dev);
 719		md_rdev_clear(&rs->dev[i].rdev);
 
 
 
 720		if (rs->dev[i].data_dev)
 721			dm_put_device(rs->ti, rs->dev[i].data_dev);
 722	}
 723
 724	kfree(rs);
 725}
 726
 727/*
 728 * For every device we have two words
 729 *  <meta_dev>: meta device name or '-' if missing
 730 *  <data_dev>: data device name or '-' if missing
 731 *
 732 * The following are permitted:
 733 *    - -
 734 *    - <data_dev>
 735 *    <meta_dev> <data_dev>
 736 *
 737 * The following is not allowed:
 738 *    <meta_dev> -
 739 *
 740 * This code parses those words.  If there is a failure,
 741 * the caller must use raid_set_free() to unwind the operations.
 742 */
 743static int parse_dev_params(struct raid_set *rs, struct dm_arg_set *as)
 744{
 745	int i;
 746	int rebuild = 0;
 747	int metadata_available = 0;
 748	int r = 0;
 749	const char *arg;
 750
 751	/* Put off the number of raid devices argument to get to dev pairs */
 752	arg = dm_shift_arg(as);
 753	if (!arg)
 754		return -EINVAL;
 755
 756	for (i = 0; i < rs->raid_disks; i++) {
 757		rs->dev[i].rdev.raid_disk = i;
 758
 759		rs->dev[i].meta_dev = NULL;
 760		rs->dev[i].data_dev = NULL;
 761
 762		/*
 763		 * There are no offsets, since there is a separate device
 764		 * for data and metadata.
 765		 */
 766		rs->dev[i].rdev.data_offset = 0;
 767		rs->dev[i].rdev.mddev = &rs->md;
 768
 769		arg = dm_shift_arg(as);
 770		if (!arg)
 771			return -EINVAL;
 772
 773		if (strcmp(arg, "-")) {
 774			r = dm_get_device(rs->ti, arg, dm_table_get_mode(rs->ti->table),
 775					  &rs->dev[i].meta_dev);
 776			if (r) {
 777				rs->ti->error = "RAID metadata device lookup failure";
 778				return r;
 779			}
 780
 781			rs->dev[i].rdev.sb_page = alloc_page(GFP_KERNEL);
 782			if (!rs->dev[i].rdev.sb_page) {
 783				rs->ti->error = "Failed to allocate superblock page";
 784				return -ENOMEM;
 785			}
 786		}
 787
 788		arg = dm_shift_arg(as);
 789		if (!arg)
 790			return -EINVAL;
 791
 792		if (!strcmp(arg, "-")) {
 793			if (!test_bit(In_sync, &rs->dev[i].rdev.flags) &&
 794			    (!rs->dev[i].rdev.recovery_offset)) {
 795				rs->ti->error = "Drive designated for rebuild not specified";
 796				return -EINVAL;
 797			}
 798
 799			if (rs->dev[i].meta_dev) {
 800				rs->ti->error = "No data device supplied with metadata device";
 801				return -EINVAL;
 802			}
 803
 804			continue;
 805		}
 806
 807		r = dm_get_device(rs->ti, arg, dm_table_get_mode(rs->ti->table),
 808				  &rs->dev[i].data_dev);
 809		if (r) {
 
 810			rs->ti->error = "RAID device lookup failure";
 811			return r;
 812		}
 813
 814		if (rs->dev[i].meta_dev) {
 815			metadata_available = 1;
 816			rs->dev[i].rdev.meta_bdev = rs->dev[i].meta_dev->bdev;
 817		}
 818		rs->dev[i].rdev.bdev = rs->dev[i].data_dev->bdev;
 819		list_add_tail(&rs->dev[i].rdev.same_set, &rs->md.disks);
 820		if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
 821			rebuild++;
 822	}
 823
 824	if (metadata_available) {
 825		rs->md.external = 0;
 826		rs->md.persistent = 1;
 827		rs->md.major_version = 2;
 828	} else if (rebuild && !rs->md.recovery_cp) {
 829		/*
 830		 * Without metadata, we will not be able to tell if the array
 831		 * is in-sync or not - we must assume it is not.  Therefore,
 832		 * it is impossible to rebuild a drive.
 833		 *
 834		 * Even if there is metadata, the on-disk information may
 835		 * indicate that the array is not in-sync and it will then
 836		 * fail at that time.
 837		 *
 838		 * User could specify 'nosync' option if desperate.
 839		 */
 840		rs->ti->error = "Unable to rebuild drive while array is not in-sync";
 
 841		return -EINVAL;
 842	}
 843
 844	return 0;
 845}
 846
 847/*
 848 * validate_region_size
 849 * @rs
 850 * @region_size:  region size in sectors.  If 0, pick a size (4MiB default).
 851 *
 852 * Set rs->md.bitmap_info.chunksize (which really refers to 'region size').
 853 * Ensure that (ti->len/region_size < 2^21) - required by MD bitmap.
 854 *
 855 * Returns: 0 on success, -EINVAL on failure.
 856 */
 857static int validate_region_size(struct raid_set *rs, unsigned long region_size)
 858{
 859	unsigned long min_region_size = rs->ti->len / (1 << 21);
 860
 861	if (rs_is_raid0(rs))
 862		return 0;
 863
 864	if (!region_size) {
 865		/*
 866		 * Choose a reasonable default.	 All figures in sectors.
 867		 */
 868		if (min_region_size > (1 << 13)) {
 869			/* If not a power of 2, make it the next power of 2 */
 870			region_size = roundup_pow_of_two(min_region_size);
 871			DMINFO("Choosing default region size of %lu sectors",
 872			       region_size);
 
 873		} else {
 874			DMINFO("Choosing default region size of 4MiB");
 875			region_size = 1 << 13; /* sectors */
 876		}
 877	} else {
 878		/*
 879		 * Validate user-supplied value.
 880		 */
 881		if (region_size > rs->ti->len) {
 882			rs->ti->error = "Supplied region size is too large";
 883			return -EINVAL;
 884		}
 885
 886		if (region_size < min_region_size) {
 887			DMERR("Supplied region_size (%lu sectors) below minimum (%lu)",
 888			      region_size, min_region_size);
 889			rs->ti->error = "Supplied region size is too small";
 890			return -EINVAL;
 891		}
 892
 893		if (!is_power_of_2(region_size)) {
 894			rs->ti->error = "Region size is not a power of 2";
 895			return -EINVAL;
 896		}
 897
 898		if (region_size < rs->md.chunk_sectors) {
 899			rs->ti->error = "Region size is smaller than the chunk size";
 900			return -EINVAL;
 901		}
 902	}
 903
 904	/*
 905	 * Convert sectors to bytes.
 906	 */
 907	rs->md.bitmap_info.chunksize = to_bytes(region_size);
 908
 909	return 0;
 910}
 911
 912/*
 913 * validate_raid_redundancy
 914 * @rs
 915 *
 916 * Determine if there are enough devices in the array that haven't
 917 * failed (or are being rebuilt) to form a usable array.
 918 *
 919 * Returns: 0 on success, -EINVAL on failure.
 920 */
 921static int validate_raid_redundancy(struct raid_set *rs)
 922{
 923	unsigned int i, rebuild_cnt = 0;
 924	unsigned int rebuilds_per_group = 0, copies;
 925	unsigned int group_size, last_group_start;
 926
 927	for (i = 0; i < rs->md.raid_disks; i++)
 928		if (!test_bit(In_sync, &rs->dev[i].rdev.flags) ||
 929		    !rs->dev[i].rdev.sb_page)
 930			rebuild_cnt++;
 931
 932	switch (rs->raid_type->level) {
 933	case 0:
 934		break;
 935	case 1:
 936		if (rebuild_cnt >= rs->md.raid_disks)
 937			goto too_many;
 938		break;
 939	case 4:
 940	case 5:
 941	case 6:
 942		if (rebuild_cnt > rs->raid_type->parity_devs)
 943			goto too_many;
 944		break;
 945	case 10:
 946		copies = raid10_md_layout_to_copies(rs->md.new_layout);
 947		if (rebuild_cnt < copies)
 948			break;
 949
 950		/*
 951		 * It is possible to have a higher rebuild count for RAID10,
 952		 * as long as the failed devices occur in different mirror
 953		 * groups (i.e. different stripes).
 954		 *
 955		 * When checking "near" format, make sure no adjacent devices
 956		 * have failed beyond what can be handled.  In addition to the
 957		 * simple case where the number of devices is a multiple of the
 958		 * number of copies, we must also handle cases where the number
 959		 * of devices is not a multiple of the number of copies.
 960		 * E.g.	   dev1 dev2 dev3 dev4 dev5
 961		 *	    A	 A    B	   B	C
 962		 *	    C	 D    D	   E	E
 963		 */
 964		if (__is_raid10_near(rs->md.new_layout)) {
 965			for (i = 0; i < rs->md.raid_disks; i++) {
 966				if (!(i % copies))
 967					rebuilds_per_group = 0;
 968				if ((!rs->dev[i].rdev.sb_page ||
 969				    !test_bit(In_sync, &rs->dev[i].rdev.flags)) &&
 970				    (++rebuilds_per_group >= copies))
 971					goto too_many;
 972			}
 973			break;
 974		}
 975
 976		/*
 977		 * When checking "far" and "offset" formats, we need to ensure
 978		 * that the device that holds its copy is not also dead or
 979		 * being rebuilt.  (Note that "far" and "offset" formats only
 980		 * support two copies right now.  These formats also only ever
 981		 * use the 'use_far_sets' variant.)
 982		 *
 983		 * This check is somewhat complicated by the need to account
 984		 * for arrays that are not a multiple of (far) copies.	This
 985		 * results in the need to treat the last (potentially larger)
 986		 * set differently.
 987		 */
 988		group_size = (rs->md.raid_disks / copies);
 989		last_group_start = (rs->md.raid_disks / group_size) - 1;
 990		last_group_start *= group_size;
 991		for (i = 0; i < rs->md.raid_disks; i++) {
 992			if (!(i % copies) && !(i > last_group_start))
 993				rebuilds_per_group = 0;
 994			if ((!rs->dev[i].rdev.sb_page ||
 995			     !test_bit(In_sync, &rs->dev[i].rdev.flags)) &&
 996			    (++rebuilds_per_group >= copies))
 997					goto too_many;
 998		}
 999		break;
1000	default:
1001		if (rebuild_cnt)
1002			return -EINVAL;
1003	}
1004
1005	return 0;
1006
1007too_many:
1008	return -EINVAL;
1009}
1010
1011/*
1012 * Possible arguments are...
1013 *	<chunk_size> [optional_args]
1014 *
1015 * Argument definitions
1016 *    <chunk_size>			The number of sectors per disk that
1017 *					will form the "stripe"
1018 *    [[no]sync]			Force or prevent recovery of the
1019 *					entire array
1020 *    [rebuild <idx>]			Rebuild the drive indicated by the index
1021 *    [daemon_sleep <ms>]		Time between bitmap daemon work to
1022 *					clear bits
1023 *    [min_recovery_rate <kB/sec/disk>]	Throttle RAID initialization
1024 *    [max_recovery_rate <kB/sec/disk>]	Throttle RAID initialization
1025 *    [write_mostly <idx>]		Indicate a write mostly drive via index
1026 *    [max_write_behind <sectors>]	See '-write-behind=' (man mdadm)
1027 *    [stripe_cache <sectors>]		Stripe cache size for higher RAIDs
1028 *    [region_size <sectors>]		Defines granularity of bitmap
1029 *
1030 * RAID10-only options:
1031 *    [raid10_copies <# copies>]	Number of copies.  (Default: 2)
1032 *    [raid10_format <near|far|offset>] Layout algorithm.  (Default: near)
1033 */
1034static int parse_raid_params(struct raid_set *rs, struct dm_arg_set *as,
1035			     unsigned int num_raid_params)
1036{
1037	int value, raid10_format = ALGORITHM_RAID10_DEFAULT;
1038	unsigned int raid10_copies = 2;
1039	unsigned int i, write_mostly = 0;
1040	unsigned int region_size = 0;
1041	sector_t max_io_len;
1042	const char *arg, *key;
1043	struct raid_dev *rd;
1044	struct raid_type *rt = rs->raid_type;
1045
1046	arg = dm_shift_arg(as);
1047	num_raid_params--; /* Account for chunk_size argument */
1048
1049	if (kstrtoint(arg, 10, &value) < 0) {
1050		rs->ti->error = "Bad numerical argument given for chunk_size";
1051		return -EINVAL;
1052	}
1053
1054	/*
1055	 * First, parse the in-order required arguments
1056	 * "chunk_size" is the only argument of this type.
1057	 */
1058	if (rt_is_raid1(rt)) {
 
 
 
1059		if (value)
1060			DMERR("Ignoring chunk size parameter for RAID 1");
1061		value = 0;
1062	} else if (!is_power_of_2(value)) {
1063		rs->ti->error = "Chunk size must be a power of 2";
1064		return -EINVAL;
1065	} else if (value < 8) {
1066		rs->ti->error = "Chunk size value is too small";
1067		return -EINVAL;
1068	}
1069
1070	rs->md.new_chunk_sectors = rs->md.chunk_sectors = value;
 
 
1071
1072	/*
1073	 * We set each individual device as In_sync with a completed
1074	 * 'recovery_offset'.  If there has been a device failure or
1075	 * replacement then one of the following cases applies:
1076	 *
1077	 *   1) User specifies 'rebuild'.
1078	 *	- Device is reset when param is read.
1079	 *   2) A new device is supplied.
1080	 *	- No matching superblock found, resets device.
1081	 *   3) Device failure was transient and returns on reload.
1082	 *	- Failure noticed, resets device for bitmap replay.
1083	 *   4) Device hadn't completed recovery after previous failure.
1084	 *	- Superblock is read and overrides recovery_offset.
1085	 *
1086	 * What is found in the superblocks of the devices is always
1087	 * authoritative, unless 'rebuild' or '[no]sync' was specified.
1088	 */
1089	for (i = 0; i < rs->raid_disks; i++) {
1090		set_bit(In_sync, &rs->dev[i].rdev.flags);
1091		rs->dev[i].rdev.recovery_offset = MaxSector;
1092	}
1093
1094	/*
1095	 * Second, parse the unordered optional arguments
1096	 */
1097	for (i = 0; i < num_raid_params; i++) {
1098		key = dm_shift_arg(as);
1099		if (!key) {
1100			rs->ti->error = "Not enough raid parameters given";
1101			return -EINVAL;
1102		}
1103
1104		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_NOSYNC))) {
1105			if (test_and_set_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
1106				rs->ti->error = "Only one 'nosync' argument allowed";
1107				return -EINVAL;
1108			}
1109			continue;
1110		}
1111		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_SYNC))) {
1112			if (test_and_set_bit(__CTR_FLAG_SYNC, &rs->ctr_flags)) {
1113				rs->ti->error = "Only one 'sync' argument allowed";
1114				return -EINVAL;
1115			}
1116			continue;
1117		}
1118		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_USE_NEAR_SETS))) {
1119			if (test_and_set_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags)) {
1120				rs->ti->error = "Only one 'raid10_use_new_sets' argument allowed";
1121				return -EINVAL;
1122			}
1123			continue;
1124		}
1125
1126		arg = dm_shift_arg(as);
1127		i++; /* Account for the argument pairs */
1128		if (!arg) {
1129			rs->ti->error = "Wrong number of raid parameters given";
1130			return -EINVAL;
1131		}
1132
1133		/*
1134		 * Parameters that take a string value are checked here.
1135		 */
1136
1137		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_FORMAT))) {
1138			if (test_and_set_bit(__CTR_FLAG_RAID10_FORMAT, &rs->ctr_flags)) {
1139				rs->ti->error = "Only one 'raid10_format' argument pair allowed";
1140				return -EINVAL;
1141			}
1142			if (!rt_is_raid10(rt)) {
1143				rs->ti->error = "'raid10_format' is an invalid parameter for this RAID type";
1144				return -EINVAL;
1145			}
1146			raid10_format = raid10_name_to_format(arg);
1147			if (raid10_format < 0) {
1148				rs->ti->error = "Invalid 'raid10_format' value given";
1149				return raid10_format;
1150			}
1151			continue;
1152		}
1153
1154		if (kstrtoint(arg, 10, &value) < 0) {
1155			rs->ti->error = "Bad numerical argument given in raid params";
1156			return -EINVAL;
1157		}
1158
1159		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_REBUILD))) {
1160			/*
1161			 * "rebuild" is being passed in by userspace to provide
1162			 * indexes of replaced devices and to set up additional
1163			 * devices on raid level takeover.
1164			 */
1165			if (!__within_range(value, 0, rs->raid_disks - 1)) {
1166				rs->ti->error = "Invalid rebuild index given";
1167				return -EINVAL;
1168			}
1169
1170			if (test_and_set_bit(value, (void *) rs->rebuild_disks)) {
1171				rs->ti->error = "rebuild for this index already given";
1172				return -EINVAL;
1173			}
1174
1175			rd = rs->dev + value;
1176			clear_bit(In_sync, &rd->rdev.flags);
1177			clear_bit(Faulty, &rd->rdev.flags);
1178			rd->rdev.recovery_offset = 0;
1179			set_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags);
1180		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_WRITE_MOSTLY))) {
1181			if (!rt_is_raid1(rt)) {
1182				rs->ti->error = "write_mostly option is only valid for RAID1";
1183				return -EINVAL;
1184			}
1185
1186			if (!__within_range(value, 0, rs->md.raid_disks - 1)) {
1187				rs->ti->error = "Invalid write_mostly index given";
1188				return -EINVAL;
1189			}
1190
1191			write_mostly++;
1192			set_bit(WriteMostly, &rs->dev[value].rdev.flags);
1193			set_bit(__CTR_FLAG_WRITE_MOSTLY, &rs->ctr_flags);
1194		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_MAX_WRITE_BEHIND))) {
1195			if (!rt_is_raid1(rt)) {
1196				rs->ti->error = "max_write_behind option is only valid for RAID1";
1197				return -EINVAL;
1198			}
1199
1200			if (test_and_set_bit(__CTR_FLAG_MAX_WRITE_BEHIND, &rs->ctr_flags)) {
1201				rs->ti->error = "Only one max_write_behind argument pair allowed";
1202				return -EINVAL;
1203			}
1204
1205			/*
1206			 * In device-mapper, we specify things in sectors, but
1207			 * MD records this value in kB
1208			 */
1209			value /= 2;
1210			if (value > COUNTER_MAX) {
1211				rs->ti->error = "Max write-behind limit out of range";
1212				return -EINVAL;
1213			}
1214
1215			rs->md.bitmap_info.max_write_behind = value;
1216		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_DAEMON_SLEEP))) {
1217			if (test_and_set_bit(__CTR_FLAG_DAEMON_SLEEP, &rs->ctr_flags)) {
1218				rs->ti->error = "Only one daemon_sleep argument pair allowed";
1219				return -EINVAL;
1220			}
1221			if (!value || (value > MAX_SCHEDULE_TIMEOUT)) {
1222				rs->ti->error = "daemon sleep period out of range";
1223				return -EINVAL;
1224			}
1225			rs->md.bitmap_info.daemon_sleep = value;
1226		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_DATA_OFFSET))) {
1227			/* Userspace passes new data_offset after having extended the the data image LV */
1228			if (test_and_set_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags)) {
1229				rs->ti->error = "Only one data_offset argument pair allowed";
1230				return -EINVAL;
1231			}
1232			/* Ensure sensible data offset */
1233			if (value < 0 ||
1234			    (value && (value < MIN_FREE_RESHAPE_SPACE || value % to_sector(PAGE_SIZE)))) {
1235				rs->ti->error = "Bogus data_offset value";
1236				return -EINVAL;
1237			}
1238			rs->data_offset = value;
1239		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_DELTA_DISKS))) {
1240			/* Define the +/-# of disks to add to/remove from the given raid set */
1241			if (test_and_set_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags)) {
1242				rs->ti->error = "Only one delta_disks argument pair allowed";
1243				return -EINVAL;
1244			}
1245			/* Ensure MAX_RAID_DEVICES and raid type minimal_devs! */
1246			if (!__within_range(abs(value), 1, MAX_RAID_DEVICES - rt->minimal_devs)) {
1247				rs->ti->error = "Too many delta_disk requested";
1248				return -EINVAL;
1249			}
1250
1251			rs->delta_disks = value;
1252		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_STRIPE_CACHE))) {
1253			if (test_and_set_bit(__CTR_FLAG_STRIPE_CACHE, &rs->ctr_flags)) {
1254				rs->ti->error = "Only one stripe_cache argument pair allowed";
1255				return -EINVAL;
1256			}
1257
1258			if (!rt_is_raid456(rt)) {
1259				rs->ti->error = "Inappropriate argument: stripe_cache";
1260				return -EINVAL;
1261			}
1262
1263			rs->stripe_cache_entries = value;
1264		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_MIN_RECOVERY_RATE))) {
1265			if (test_and_set_bit(__CTR_FLAG_MIN_RECOVERY_RATE, &rs->ctr_flags)) {
1266				rs->ti->error = "Only one min_recovery_rate argument pair allowed";
1267				return -EINVAL;
1268			}
 
 
1269			if (value > INT_MAX) {
1270				rs->ti->error = "min_recovery_rate out of range";
1271				return -EINVAL;
1272			}
1273			rs->md.sync_speed_min = (int)value;
1274		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_MAX_RECOVERY_RATE))) {
1275			if (test_and_set_bit(__CTR_FLAG_MAX_RECOVERY_RATE, &rs->ctr_flags)) {
1276				rs->ti->error = "Only one max_recovery_rate argument pair allowed";
1277				return -EINVAL;
1278			}
1279			if (value > INT_MAX) {
1280				rs->ti->error = "max_recovery_rate out of range";
1281				return -EINVAL;
1282			}
1283			rs->md.sync_speed_max = (int)value;
1284		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_REGION_SIZE))) {
1285			if (test_and_set_bit(__CTR_FLAG_REGION_SIZE, &rs->ctr_flags)) {
1286				rs->ti->error = "Only one region_size argument pair allowed";
1287				return -EINVAL;
1288			}
1289
1290			region_size = value;
1291			rs->requested_bitmap_chunk_sectors = value;
1292		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_COPIES))) {
1293			if (test_and_set_bit(__CTR_FLAG_RAID10_COPIES, &rs->ctr_flags)) {
1294				rs->ti->error = "Only one raid10_copies argument pair allowed";
1295				return -EINVAL;
1296			}
1297
1298			if (!__within_range(value, 2, rs->md.raid_disks)) {
1299				rs->ti->error = "Bad value for 'raid10_copies'";
1300				return -EINVAL;
1301			}
1302
1303			raid10_copies = value;
1304		} else {
1305			DMERR("Unable to parse RAID parameter: %s", key);
1306			rs->ti->error = "Unable to parse RAID parameter";
1307			return -EINVAL;
1308		}
1309	}
1310
1311	if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags) &&
1312	    test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
1313		rs->ti->error = "sync and nosync are mutually exclusive";
1314		return -EINVAL;
1315	}
1316
1317	if (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags) &&
1318	    (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags) ||
1319	     test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))) {
1320		rs->ti->error = "sync/nosync and rebuild are mutually exclusive";
1321		return -EINVAL;
1322	}
1323
1324	if (write_mostly >= rs->md.raid_disks) {
1325		rs->ti->error = "Can't set all raid1 devices to write_mostly";
1326		return -EINVAL;
1327	}
1328
1329	if (validate_region_size(rs, region_size))
1330		return -EINVAL;
1331
1332	if (rs->md.chunk_sectors)
1333		max_io_len = rs->md.chunk_sectors;
1334	else
1335		max_io_len = region_size;
1336
1337	if (dm_set_target_max_io_len(rs->ti, max_io_len))
1338		return -EINVAL;
1339
1340	if (rt_is_raid10(rt)) {
1341		if (raid10_copies > rs->md.raid_disks) {
1342			rs->ti->error = "Not enough devices to satisfy specification";
1343			return -EINVAL;
1344		}
1345
1346		rs->md.new_layout = raid10_format_to_md_layout(rs, raid10_format, raid10_copies);
1347		if (rs->md.new_layout < 0) {
1348			rs->ti->error = "Error getting raid10 format";
1349			return rs->md.new_layout;
1350		}
1351
1352		rt = get_raid_type_by_ll(10, rs->md.new_layout);
1353		if (!rt) {
1354			rs->ti->error = "Failed to recognize new raid10 layout";
1355			return -EINVAL;
1356		}
1357
1358		if ((rt->algorithm == ALGORITHM_RAID10_DEFAULT ||
1359		     rt->algorithm == ALGORITHM_RAID10_NEAR) &&
1360		    test_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags)) {
1361			rs->ti->error = "RAID10 format 'near' and 'raid10_use_near_sets' are incompatible";
1362			return -EINVAL;
1363		}
1364	}
1365
1366	rs->raid10_copies = raid10_copies;
1367
1368	/* Assume there are no metadata devices until the drives are parsed */
1369	rs->md.persistent = 0;
1370	rs->md.external = 1;
1371
1372	/* Check, if any invalid ctr arguments have been passed in for the raid level */
1373	return rs_check_for_valid_flags(rs);
1374}
1375
1376/* Set raid4/5/6 cache size */
1377static int rs_set_raid456_stripe_cache(struct raid_set *rs)
1378{
1379	int r;
1380	struct r5conf *conf;
1381	struct mddev *mddev = &rs->md;
1382	uint32_t min_stripes = max(mddev->chunk_sectors, mddev->new_chunk_sectors) / 2;
1383	uint32_t nr_stripes = rs->stripe_cache_entries;
1384
1385	if (!rt_is_raid456(rs->raid_type)) {
1386		rs->ti->error = "Inappropriate raid level; cannot change stripe_cache size";
1387		return -EINVAL;
1388	}
1389
1390	if (nr_stripes < min_stripes) {
1391		DMINFO("Adjusting requested %u stripe cache entries to %u to suit stripe size",
1392		       nr_stripes, min_stripes);
1393		nr_stripes = min_stripes;
1394	}
1395
1396	conf = mddev->private;
1397	if (!conf) {
1398		rs->ti->error = "Cannot change stripe_cache size on inactive RAID set";
1399		return -EINVAL;
1400	}
1401
1402	/* Try setting number of stripes in raid456 stripe cache */
1403	if (conf->min_nr_stripes != nr_stripes) {
1404		r = raid5_set_cache_size(mddev, nr_stripes);
1405		if (r) {
1406			rs->ti->error = "Failed to set raid4/5/6 stripe cache size";
1407			return r;
1408		}
1409
1410		DMINFO("%u stripe cache entries", nr_stripes);
1411	}
1412
1413	return 0;
1414}
1415
1416/* Return # of data stripes as kept in mddev as of @rs (i.e. as of superblock) */
1417static unsigned int mddev_data_stripes(struct raid_set *rs)
1418{
1419	return rs->md.raid_disks - rs->raid_type->parity_devs;
1420}
1421
1422/* Return # of data stripes of @rs (i.e. as of ctr) */
1423static unsigned int rs_data_stripes(struct raid_set *rs)
1424{
1425	return rs->raid_disks - rs->raid_type->parity_devs;
1426}
1427
1428/* Calculate the sectors per device and per array used for @rs */
1429static int rs_set_dev_and_array_sectors(struct raid_set *rs, bool use_mddev)
1430{
1431	int delta_disks;
1432	unsigned int data_stripes;
1433	struct mddev *mddev = &rs->md;
1434	struct md_rdev *rdev;
1435	sector_t array_sectors = rs->ti->len, dev_sectors = rs->ti->len;
1436
1437	if (use_mddev) {
1438		delta_disks = mddev->delta_disks;
1439		data_stripes = mddev_data_stripes(rs);
1440	} else {
1441		delta_disks = rs->delta_disks;
1442		data_stripes = rs_data_stripes(rs);
1443	}
1444
1445	/* Special raid1 case w/o delta_disks support (yet) */
1446	if (rt_is_raid1(rs->raid_type))
1447		;
1448	else if (rt_is_raid10(rs->raid_type)) {
1449		if (rs->raid10_copies < 2 ||
1450		    delta_disks < 0) {
1451			rs->ti->error = "Bogus raid10 data copies or delta disks";
1452			return -EINVAL;
1453		}
1454
1455		dev_sectors *= rs->raid10_copies;
1456		if (sector_div(dev_sectors, data_stripes))
1457			goto bad;
1458
1459		array_sectors = (data_stripes + delta_disks) * dev_sectors;
1460		if (sector_div(array_sectors, rs->raid10_copies))
1461			goto bad;
1462
1463	} else if (sector_div(dev_sectors, data_stripes))
1464		goto bad;
1465
1466	else
1467		/* Striped layouts */
1468		array_sectors = (data_stripes + delta_disks) * dev_sectors;
1469
1470	rdev_for_each(rdev, mddev)
1471		rdev->sectors = dev_sectors;
1472
1473	mddev->array_sectors = array_sectors;
1474	mddev->dev_sectors = dev_sectors;
1475
1476	return 0;
1477bad:
1478	rs->ti->error = "Target length not divisible by number of data devices";
1479	return -EINVAL;
1480}
1481
1482/* Setup recovery on @rs */
1483static void __rs_setup_recovery(struct raid_set *rs, sector_t dev_sectors)
1484{
1485	/* raid0 does not recover */
1486	if (rs_is_raid0(rs))
1487		rs->md.recovery_cp = MaxSector;
1488	/*
1489	 * A raid6 set has to be recovered either
1490	 * completely or for the grown part to
1491	 * ensure proper parity and Q-Syndrome
1492	 */
1493	else if (rs_is_raid6(rs))
1494		rs->md.recovery_cp = dev_sectors;
1495	/*
1496	 * Other raid set types may skip recovery
1497	 * depending on the 'nosync' flag.
1498	 */
1499	else
1500		rs->md.recovery_cp = test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)
1501				     ? MaxSector : dev_sectors;
1502}
1503
1504/* Setup recovery on @rs based on raid type, device size and 'nosync' flag */
1505static void rs_setup_recovery(struct raid_set *rs, sector_t dev_sectors)
1506{
1507	if (!dev_sectors)
1508		/* New raid set or 'sync' flag provided */
1509		__rs_setup_recovery(rs, 0);
1510	else if (dev_sectors == MaxSector)
1511		/* Prevent recovery */
1512		__rs_setup_recovery(rs, MaxSector);
1513	else if (rs->dev[0].rdev.sectors < dev_sectors)
1514		/* Grown raid set */
1515		__rs_setup_recovery(rs, rs->dev[0].rdev.sectors);
1516	else
1517		__rs_setup_recovery(rs, MaxSector);
1518}
1519
1520static void do_table_event(struct work_struct *ws)
1521{
1522	struct raid_set *rs = container_of(ws, struct raid_set, md.event_work);
1523
1524	smp_rmb(); /* Make sure we access most actual mddev properties */
1525	if (!rs_is_reshaping(rs))
1526		rs_set_capacity(rs);
1527	dm_table_event(rs->ti->table);
1528}
1529
1530static int raid_is_congested(struct dm_target_callbacks *cb, int bits)
1531{
1532	struct raid_set *rs = container_of(cb, struct raid_set, callbacks);
1533
1534	return mddev_congested(&rs->md, bits);
1535}
1536
1537/*
1538 * Make sure a valid takover (level switch) is being requested on @rs
1539 *
1540 * Conversions of raid sets from one MD personality to another
1541 * have to conform to restrictions which are enforced here.
1542 */
1543static int rs_check_takeover(struct raid_set *rs)
1544{
1545	struct mddev *mddev = &rs->md;
1546	unsigned int near_copies;
1547
1548	if (rs->md.degraded) {
1549		rs->ti->error = "Can't takeover degraded raid set";
1550		return -EPERM;
1551	}
1552
1553	if (rs_is_reshaping(rs)) {
1554		rs->ti->error = "Can't takeover reshaping raid set";
1555		return -EPERM;
1556	}
1557
1558	switch (mddev->level) {
1559	case 0:
1560		/* raid0 -> raid1/5 with one disk */
1561		if ((mddev->new_level == 1 || mddev->new_level == 5) &&
1562		    mddev->raid_disks == 1)
1563			return 0;
1564
1565		/* raid0 -> raid10 */
1566		if (mddev->new_level == 10 &&
1567		    !(rs->raid_disks % mddev->raid_disks))
1568			return 0;
1569
1570		/* raid0 with multiple disks -> raid4/5/6 */
1571		if (__within_range(mddev->new_level, 4, 6) &&
1572		    mddev->new_layout == ALGORITHM_PARITY_N &&
1573		    mddev->raid_disks > 1)
1574			return 0;
1575
1576		break;
1577
1578	case 10:
1579		/* Can't takeover raid10_offset! */
1580		if (__is_raid10_offset(mddev->layout))
1581			break;
1582
1583		near_copies = __raid10_near_copies(mddev->layout);
1584
1585		/* raid10* -> raid0 */
1586		if (mddev->new_level == 0) {
1587			/* Can takeover raid10_near with raid disks divisable by data copies! */
1588			if (near_copies > 1 &&
1589			    !(mddev->raid_disks % near_copies)) {
1590				mddev->raid_disks /= near_copies;
1591				mddev->delta_disks = mddev->raid_disks;
1592				return 0;
1593			}
1594
1595			/* Can takeover raid10_far */
1596			if (near_copies == 1 &&
1597			    __raid10_far_copies(mddev->layout) > 1)
1598				return 0;
1599
1600			break;
1601		}
1602
1603		/* raid10_{near,far} -> raid1 */
1604		if (mddev->new_level == 1 &&
1605		    max(near_copies, __raid10_far_copies(mddev->layout)) == mddev->raid_disks)
1606			return 0;
1607
1608		/* raid10_{near,far} with 2 disks -> raid4/5 */
1609		if (__within_range(mddev->new_level, 4, 5) &&
1610		    mddev->raid_disks == 2)
1611			return 0;
1612		break;
1613
1614	case 1:
1615		/* raid1 with 2 disks -> raid4/5 */
1616		if (__within_range(mddev->new_level, 4, 5) &&
1617		    mddev->raid_disks == 2) {
1618			mddev->degraded = 1;
1619			return 0;
1620		}
1621
1622		/* raid1 -> raid0 */
1623		if (mddev->new_level == 0 &&
1624		    mddev->raid_disks == 1)
1625			return 0;
1626
1627		/* raid1 -> raid10 */
1628		if (mddev->new_level == 10)
1629			return 0;
1630		break;
1631
1632	case 4:
1633		/* raid4 -> raid0 */
1634		if (mddev->new_level == 0)
1635			return 0;
1636
1637		/* raid4 -> raid1/5 with 2 disks */
1638		if ((mddev->new_level == 1 || mddev->new_level == 5) &&
1639		    mddev->raid_disks == 2)
1640			return 0;
1641
1642		/* raid4 -> raid5/6 with parity N */
1643		if (__within_range(mddev->new_level, 5, 6) &&
1644		    mddev->layout == ALGORITHM_PARITY_N)
1645			return 0;
1646		break;
1647
1648	case 5:
1649		/* raid5 with parity N -> raid0 */
1650		if (mddev->new_level == 0 &&
1651		    mddev->layout == ALGORITHM_PARITY_N)
1652			return 0;
1653
1654		/* raid5 with parity N -> raid4 */
1655		if (mddev->new_level == 4 &&
1656		    mddev->layout == ALGORITHM_PARITY_N)
1657			return 0;
1658
1659		/* raid5 with 2 disks -> raid1/4/10 */
1660		if ((mddev->new_level == 1 || mddev->new_level == 4 || mddev->new_level == 10) &&
1661		    mddev->raid_disks == 2)
1662			return 0;
1663
1664		/* raid5_* ->  raid6_*_6 with Q-Syndrome N (e.g. raid5_ra -> raid6_ra_6 */
1665		if (mddev->new_level == 6 &&
1666		    ((mddev->layout == ALGORITHM_PARITY_N && mddev->new_layout == ALGORITHM_PARITY_N) ||
1667		      __within_range(mddev->new_layout, ALGORITHM_LEFT_ASYMMETRIC_6, ALGORITHM_RIGHT_SYMMETRIC_6)))
1668			return 0;
1669		break;
1670
1671	case 6:
1672		/* raid6 with parity N -> raid0 */
1673		if (mddev->new_level == 0 &&
1674		    mddev->layout == ALGORITHM_PARITY_N)
1675			return 0;
1676
1677		/* raid6 with parity N -> raid4 */
1678		if (mddev->new_level == 4 &&
1679		    mddev->layout == ALGORITHM_PARITY_N)
1680			return 0;
1681
1682		/* raid6_*_n with Q-Syndrome N -> raid5_* */
1683		if (mddev->new_level == 5 &&
1684		    ((mddev->layout == ALGORITHM_PARITY_N && mddev->new_layout == ALGORITHM_PARITY_N) ||
1685		     __within_range(mddev->new_layout, ALGORITHM_LEFT_ASYMMETRIC, ALGORITHM_RIGHT_SYMMETRIC)))
1686			return 0;
1687
1688	default:
1689		break;
1690	}
1691
1692	rs->ti->error = "takeover not possible";
1693	return -EINVAL;
1694}
1695
1696/* True if @rs requested to be taken over */
1697static bool rs_takeover_requested(struct raid_set *rs)
1698{
1699	return rs->md.new_level != rs->md.level;
1700}
1701
1702/* True if @rs is requested to reshape by ctr */
1703static bool rs_reshape_requested(struct raid_set *rs)
1704{
1705	bool change;
1706	struct mddev *mddev = &rs->md;
1707
1708	if (rs_takeover_requested(rs))
1709		return false;
1710
1711	if (!mddev->level)
1712		return false;
1713
1714	change = mddev->new_layout != mddev->layout ||
1715		 mddev->new_chunk_sectors != mddev->chunk_sectors ||
1716		 rs->delta_disks;
1717
1718	/* Historical case to support raid1 reshape without delta disks */
1719	if (mddev->level == 1) {
1720		if (rs->delta_disks)
1721			return !!rs->delta_disks;
1722
1723		return !change &&
1724		       mddev->raid_disks != rs->raid_disks;
1725	}
1726
1727	if (mddev->level == 10)
1728		return change &&
1729		       !__is_raid10_far(mddev->new_layout) &&
1730		       rs->delta_disks >= 0;
1731
1732	return change;
1733}
1734
1735/*  Features */
1736#define	FEATURE_FLAG_SUPPORTS_V190	0x1 /* Supports extended superblock */
1737
1738/* State flags for sb->flags */
1739#define	SB_FLAG_RESHAPE_ACTIVE		0x1
1740#define	SB_FLAG_RESHAPE_BACKWARDS	0x2
1741
1742/*
1743 * This structure is never routinely used by userspace, unlike md superblocks.
1744 * Devices with this superblock should only ever be accessed via device-mapper.
1745 */
1746#define DM_RAID_MAGIC 0x64526D44
1747struct dm_raid_superblock {
1748	__le32 magic;		/* "DmRd" */
1749	__le32 compat_features;	/* Used to indicate compatible features (like 1.9.0 ondisk metadata extension) */
1750
1751	__le32 num_devices;	/* Number of devices in this raid set. (Max 64) */
1752	__le32 array_position;	/* The position of this drive in the raid set */
1753
1754	__le64 events;		/* Incremented by md when superblock updated */
1755	__le64 failed_devices;	/* Pre 1.9.0 part of bit field of devices to */
1756				/* indicate failures (see extension below) */
1757
1758	/*
1759	 * This offset tracks the progress of the repair or replacement of
1760	 * an individual drive.
1761	 */
1762	__le64 disk_recovery_offset;
1763
1764	/*
1765	 * This offset tracks the progress of the initial raid set
1766	 * synchronisation/parity calculation.
1767	 */
1768	__le64 array_resync_offset;
1769
1770	/*
1771	 * raid characteristics
1772	 */
1773	__le32 level;
1774	__le32 layout;
1775	__le32 stripe_sectors;
1776
1777	/********************************************************************
1778	 * BELOW FOLLOW V1.9.0 EXTENSIONS TO THE PRISTINE SUPERBLOCK FORMAT!!!
1779	 *
1780	 * FEATURE_FLAG_SUPPORTS_V190 in the features member indicates that those exist
1781	 */
1782
1783	__le32 flags; /* Flags defining array states for reshaping */
1784
1785	/*
1786	 * This offset tracks the progress of a raid
1787	 * set reshape in order to be able to restart it
1788	 */
1789	__le64 reshape_position;
1790
1791	/*
1792	 * These define the properties of the array in case of an interrupted reshape
1793	 */
1794	__le32 new_level;
1795	__le32 new_layout;
1796	__le32 new_stripe_sectors;
1797	__le32 delta_disks;
1798
1799	__le64 array_sectors; /* Array size in sectors */
1800
1801	/*
1802	 * Sector offsets to data on devices (reshaping).
1803	 * Needed to support out of place reshaping, thus
1804	 * not writing over any stripes whilst converting
1805	 * them from old to new layout
1806	 */
1807	__le64 data_offset;
1808	__le64 new_data_offset;
1809
1810	__le64 sectors; /* Used device size in sectors */
1811
1812	/*
1813	 * Additonal Bit field of devices indicating failures to support
1814	 * up to 256 devices with the 1.9.0 on-disk metadata format
1815	 */
1816	__le64 extended_failed_devices[DISKS_ARRAY_ELEMS - 1];
1817
1818	__le32 incompat_features;	/* Used to indicate any incompatible features */
1819
1820	/* Always set rest up to logical block size to 0 when writing (see get_metadata_device() below). */
1821} __packed;
1822
1823/*
1824 * Check for reshape constraints on raid set @rs:
1825 *
1826 * - reshape function non-existent
1827 * - degraded set
1828 * - ongoing recovery
1829 * - ongoing reshape
1830 *
1831 * Returns 0 if none or -EPERM if given constraint
1832 * and error message reference in @errmsg
1833 */
1834static int rs_check_reshape(struct raid_set *rs)
1835{
1836	struct mddev *mddev = &rs->md;
1837
1838	if (!mddev->pers || !mddev->pers->check_reshape)
1839		rs->ti->error = "Reshape not supported";
1840	else if (mddev->degraded)
1841		rs->ti->error = "Can't reshape degraded raid set";
1842	else if (rs_is_recovering(rs))
1843		rs->ti->error = "Convert request on recovering raid set prohibited";
1844	else if (rs_is_reshaping(rs))
1845		rs->ti->error = "raid set already reshaping!";
1846	else if (!(rs_is_raid1(rs) || rs_is_raid10(rs) || rs_is_raid456(rs)))
1847		rs->ti->error = "Reshaping only supported for raid1/4/5/6/10";
1848	else
1849		return 0;
1850
1851	return -EPERM;
1852}
1853
1854static int read_disk_sb(struct md_rdev *rdev, int size)
1855{
1856	BUG_ON(!rdev->sb_page);
1857
1858	if (rdev->sb_loaded)
1859		return 0;
1860
1861	if (!sync_page_io(rdev, 0, size, rdev->sb_page, REQ_OP_READ, 0, true)) {
1862		DMERR("Failed to read superblock of device at position %d",
1863		      rdev->raid_disk);
1864		md_error(rdev->mddev, rdev);
1865		return -EINVAL;
1866	}
1867
1868	rdev->sb_loaded = 1;
1869
1870	return 0;
1871}
1872
1873static void sb_retrieve_failed_devices(struct dm_raid_superblock *sb, uint64_t *failed_devices)
1874{
1875	failed_devices[0] = le64_to_cpu(sb->failed_devices);
1876	memset(failed_devices + 1, 0, sizeof(sb->extended_failed_devices));
1877
1878	if (le32_to_cpu(sb->compat_features) & FEATURE_FLAG_SUPPORTS_V190) {
1879		int i = ARRAY_SIZE(sb->extended_failed_devices);
1880
1881		while (i--)
1882			failed_devices[i+1] = le64_to_cpu(sb->extended_failed_devices[i]);
1883	}
1884}
1885
1886static void sb_update_failed_devices(struct dm_raid_superblock *sb, uint64_t *failed_devices)
1887{
1888	int i = ARRAY_SIZE(sb->extended_failed_devices);
1889
1890	sb->failed_devices = cpu_to_le64(failed_devices[0]);
1891	while (i--)
1892		sb->extended_failed_devices[i] = cpu_to_le64(failed_devices[i+1]);
1893}
1894
1895/*
1896 * Synchronize the superblock members with the raid set properties
1897 *
1898 * All superblock data is little endian.
1899 */
1900static void super_sync(struct mddev *mddev, struct md_rdev *rdev)
1901{
1902	bool update_failed_devices = false;
1903	unsigned int i;
1904	uint64_t failed_devices[DISKS_ARRAY_ELEMS];
1905	struct dm_raid_superblock *sb;
1906	struct raid_set *rs = container_of(mddev, struct raid_set, md);
1907
1908	/* No metadata device, no superblock */
1909	if (!rdev->meta_bdev)
1910		return;
1911
1912	BUG_ON(!rdev->sb_page);
1913
1914	sb = page_address(rdev->sb_page);
 
1915
1916	sb_retrieve_failed_devices(sb, failed_devices);
1917
1918	for (i = 0; i < rs->raid_disks; i++)
1919		if (!rs->dev[i].data_dev || test_bit(Faulty, &rs->dev[i].rdev.flags)) {
1920			update_failed_devices = true;
1921			set_bit(i, (void *) failed_devices);
1922		}
1923
1924	if (update_failed_devices)
1925		sb_update_failed_devices(sb, failed_devices);
1926
1927	sb->magic = cpu_to_le32(DM_RAID_MAGIC);
1928	sb->compat_features = cpu_to_le32(FEATURE_FLAG_SUPPORTS_V190);
1929
1930	sb->num_devices = cpu_to_le32(mddev->raid_disks);
1931	sb->array_position = cpu_to_le32(rdev->raid_disk);
1932
1933	sb->events = cpu_to_le64(mddev->events);
 
1934
1935	sb->disk_recovery_offset = cpu_to_le64(rdev->recovery_offset);
1936	sb->array_resync_offset = cpu_to_le64(mddev->recovery_cp);
1937
1938	sb->level = cpu_to_le32(mddev->level);
1939	sb->layout = cpu_to_le32(mddev->layout);
1940	sb->stripe_sectors = cpu_to_le32(mddev->chunk_sectors);
1941
1942	sb->new_level = cpu_to_le32(mddev->new_level);
1943	sb->new_layout = cpu_to_le32(mddev->new_layout);
1944	sb->new_stripe_sectors = cpu_to_le32(mddev->new_chunk_sectors);
1945
1946	sb->delta_disks = cpu_to_le32(mddev->delta_disks);
1947
1948	smp_rmb(); /* Make sure we access most recent reshape position */
1949	sb->reshape_position = cpu_to_le64(mddev->reshape_position);
1950	if (le64_to_cpu(sb->reshape_position) != MaxSector) {
1951		/* Flag ongoing reshape */
1952		sb->flags |= cpu_to_le32(SB_FLAG_RESHAPE_ACTIVE);
1953
1954		if (mddev->delta_disks < 0 || mddev->reshape_backwards)
1955			sb->flags |= cpu_to_le32(SB_FLAG_RESHAPE_BACKWARDS);
1956	} else {
1957		/* Clear reshape flags */
1958		sb->flags &= ~(cpu_to_le32(SB_FLAG_RESHAPE_ACTIVE|SB_FLAG_RESHAPE_BACKWARDS));
1959	}
1960
1961	sb->array_sectors = cpu_to_le64(mddev->array_sectors);
1962	sb->data_offset = cpu_to_le64(rdev->data_offset);
1963	sb->new_data_offset = cpu_to_le64(rdev->new_data_offset);
1964	sb->sectors = cpu_to_le64(rdev->sectors);
1965	sb->incompat_features = cpu_to_le32(0);
1966
1967	/* Zero out the rest of the payload after the size of the superblock */
1968	memset(sb + 1, 0, rdev->sb_size - sizeof(*sb));
1969}
1970
1971/*
1972 * super_load
1973 *
1974 * This function creates a superblock if one is not found on the device
1975 * and will decide which superblock to use if there's a choice.
1976 *
1977 * Return: 1 if use rdev, 0 if use refdev, -Exxx otherwise
1978 */
1979static int super_load(struct md_rdev *rdev, struct md_rdev *refdev)
1980{
1981	int r;
1982	struct dm_raid_superblock *sb;
1983	struct dm_raid_superblock *refsb;
1984	uint64_t events_sb, events_refsb;
1985
1986	rdev->sb_start = 0;
1987	rdev->sb_size = bdev_logical_block_size(rdev->meta_bdev);
1988	if (rdev->sb_size < sizeof(*sb) || rdev->sb_size > PAGE_SIZE) {
1989		DMERR("superblock size of a logical block is no longer valid");
1990		return -EINVAL;
1991	}
1992
1993	r = read_disk_sb(rdev, rdev->sb_size);
1994	if (r)
1995		return r;
1996
1997	sb = page_address(rdev->sb_page);
1998
1999	/*
2000	 * Two cases that we want to write new superblocks and rebuild:
2001	 * 1) New device (no matching magic number)
2002	 * 2) Device specified for rebuild (!In_sync w/ offset == 0)
2003	 */
2004	if ((sb->magic != cpu_to_le32(DM_RAID_MAGIC)) ||
2005	    (!test_bit(In_sync, &rdev->flags) && !rdev->recovery_offset)) {
2006		super_sync(rdev->mddev, rdev);
2007
2008		set_bit(FirstUse, &rdev->flags);
2009		sb->compat_features = cpu_to_le32(FEATURE_FLAG_SUPPORTS_V190);
2010
2011		/* Force writing of superblocks to disk */
2012		set_bit(MD_SB_CHANGE_DEVS, &rdev->mddev->sb_flags);
2013
2014		/* Any superblock is better than none, choose that if given */
2015		return refdev ? 0 : 1;
2016	}
2017
2018	if (!refdev)
2019		return 1;
2020
2021	events_sb = le64_to_cpu(sb->events);
2022
2023	refsb = page_address(refdev->sb_page);
2024	events_refsb = le64_to_cpu(refsb->events);
2025
2026	return (events_sb > events_refsb) ? 1 : 0;
2027}
2028
2029static int super_init_validation(struct raid_set *rs, struct md_rdev *rdev)
2030{
2031	int role;
2032	unsigned int d;
2033	struct mddev *mddev = &rs->md;
2034	uint64_t events_sb;
2035	uint64_t failed_devices[DISKS_ARRAY_ELEMS];
2036	struct dm_raid_superblock *sb;
2037	uint32_t new_devs = 0, rebuild_and_new = 0, rebuilds = 0;
2038	struct md_rdev *r;
 
2039	struct dm_raid_superblock *sb2;
2040
2041	sb = page_address(rdev->sb_page);
2042	events_sb = le64_to_cpu(sb->events);
 
2043
2044	/*
2045	 * Initialise to 1 if this is a new superblock.
2046	 */
2047	mddev->events = events_sb ? : 1;
2048
2049	mddev->reshape_position = MaxSector;
2050
2051	mddev->raid_disks = le32_to_cpu(sb->num_devices);
2052	mddev->level = le32_to_cpu(sb->level);
2053	mddev->layout = le32_to_cpu(sb->layout);
2054	mddev->chunk_sectors = le32_to_cpu(sb->stripe_sectors);
2055
2056	/*
2057	 * Reshaping is supported, e.g. reshape_position is valid
2058	 * in superblock and superblock content is authoritative.
2059	 */
2060	if (le32_to_cpu(sb->compat_features) & FEATURE_FLAG_SUPPORTS_V190) {
2061		/* Superblock is authoritative wrt given raid set layout! */
2062		mddev->new_level = le32_to_cpu(sb->new_level);
2063		mddev->new_layout = le32_to_cpu(sb->new_layout);
2064		mddev->new_chunk_sectors = le32_to_cpu(sb->new_stripe_sectors);
2065		mddev->delta_disks = le32_to_cpu(sb->delta_disks);
2066		mddev->array_sectors = le64_to_cpu(sb->array_sectors);
2067
2068		/* raid was reshaping and got interrupted */
2069		if (le32_to_cpu(sb->flags) & SB_FLAG_RESHAPE_ACTIVE) {
2070			if (test_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags)) {
2071				DMERR("Reshape requested but raid set is still reshaping");
2072				return -EINVAL;
2073			}
2074
2075			if (mddev->delta_disks < 0 ||
2076			    (!mddev->delta_disks && (le32_to_cpu(sb->flags) & SB_FLAG_RESHAPE_BACKWARDS)))
2077				mddev->reshape_backwards = 1;
2078			else
2079				mddev->reshape_backwards = 0;
2080
2081			mddev->reshape_position = le64_to_cpu(sb->reshape_position);
2082			rs->raid_type = get_raid_type_by_ll(mddev->level, mddev->layout);
2083		}
2084
2085	} else {
2086		/*
2087		 * No takeover/reshaping, because we don't have the extended v1.9.0 metadata
2088		 */
2089		struct raid_type *rt_cur = get_raid_type_by_ll(mddev->level, mddev->layout);
2090		struct raid_type *rt_new = get_raid_type_by_ll(mddev->new_level, mddev->new_layout);
2091
2092		if (rs_takeover_requested(rs)) {
2093			if (rt_cur && rt_new)
2094				DMERR("Takeover raid sets from %s to %s not yet supported by metadata. (raid level change)",
2095				      rt_cur->name, rt_new->name);
2096			else
2097				DMERR("Takeover raid sets not yet supported by metadata. (raid level change)");
2098			return -EINVAL;
2099		} else if (rs_reshape_requested(rs)) {
2100			DMERR("Reshaping raid sets not yet supported by metadata. (raid layout change keeping level)");
2101			if (mddev->layout != mddev->new_layout) {
2102				if (rt_cur && rt_new)
2103					DMERR("	 current layout %s vs new layout %s",
2104					      rt_cur->name, rt_new->name);
2105				else
2106					DMERR("	 current layout 0x%X vs new layout 0x%X",
2107					      le32_to_cpu(sb->layout), mddev->new_layout);
2108			}
2109			if (mddev->chunk_sectors != mddev->new_chunk_sectors)
2110				DMERR("	 current stripe sectors %u vs new stripe sectors %u",
2111				      mddev->chunk_sectors, mddev->new_chunk_sectors);
2112			if (rs->delta_disks)
2113				DMERR("	 current %u disks vs new %u disks",
2114				      mddev->raid_disks, mddev->raid_disks + rs->delta_disks);
2115			if (rs_is_raid10(rs)) {
2116				DMERR("	 Old layout: %s w/ %u copies",
2117				      raid10_md_layout_to_format(mddev->layout),
2118				      raid10_md_layout_to_copies(mddev->layout));
2119				DMERR("	 New layout: %s w/ %u copies",
2120				      raid10_md_layout_to_format(mddev->new_layout),
2121				      raid10_md_layout_to_copies(mddev->new_layout));
2122			}
2123			return -EINVAL;
2124		}
2125
2126		DMINFO("Discovered old metadata format; upgrading to extended metadata format");
2127	}
2128
2129	if (!test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))
2130		mddev->recovery_cp = le64_to_cpu(sb->array_resync_offset);
2131
2132	/*
2133	 * During load, we set FirstUse if a new superblock was written.
2134	 * There are two reasons we might not have a superblock:
2135	 * 1) The raid set is brand new - in which case, all of the
2136	 *    devices must have their In_sync bit set.	Also,
2137	 *    recovery_cp must be 0, unless forced.
2138	 * 2) This is a new device being added to an old raid set
2139	 *    and the new device needs to be rebuilt - in which
2140	 *    case the In_sync bit will /not/ be set and
2141	 *    recovery_cp must be MaxSector.
2142	 * 3) This is/are a new device(s) being added to an old
2143	 *    raid set during takeover to a higher raid level
2144	 *    to provide capacity for redundancy or during reshape
2145	 *    to add capacity to grow the raid set.
2146	 */
2147	d = 0;
2148	rdev_for_each(r, mddev) {
2149		if (test_bit(FirstUse, &r->flags))
2150			new_devs++;
2151
2152		if (!test_bit(In_sync, &r->flags)) {
2153			DMINFO("Device %d specified for rebuild; clearing superblock",
2154				r->raid_disk);
 
 
 
2155			rebuilds++;
2156
2157			if (test_bit(FirstUse, &r->flags))
2158				rebuild_and_new++;
2159		}
2160
2161		d++;
2162	}
2163
2164	if (new_devs == rs->raid_disks || !rebuilds) {
2165		/* Replace a broken device */
2166		if (new_devs == 1 && !rs->delta_disks)
2167			;
2168		if (new_devs == rs->raid_disks) {
2169			DMINFO("Superblocks created for new raid set");
2170			set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
2171		} else if (new_devs != rebuilds &&
2172			   new_devs != rs->delta_disks) {
2173			DMERR("New device injected into existing raid set without "
2174			      "'delta_disks' or 'rebuild' parameter specified");
2175			return -EINVAL;
2176		}
2177	} else if (new_devs && new_devs != rebuilds) {
2178		DMERR("%u 'rebuild' devices cannot be injected into"
2179		      " a raid set with %u other first-time devices",
2180		      rebuilds, new_devs);
 
 
2181		return -EINVAL;
2182	} else if (rebuilds) {
2183		if (rebuild_and_new && rebuilds != rebuild_and_new) {
2184			DMERR("new device%s provided without 'rebuild'",
2185			      new_devs > 1 ? "s" : "");
2186			return -EINVAL;
2187		} else if (rs_is_recovering(rs)) {
2188			DMERR("'rebuild' specified while raid set is not in-sync (recovery_cp=%llu)",
2189			      (unsigned long long) mddev->recovery_cp);
2190			return -EINVAL;
2191		} else if (rs_is_reshaping(rs)) {
2192			DMERR("'rebuild' specified while raid set is being reshaped (reshape_position=%llu)",
2193			      (unsigned long long) mddev->reshape_position);
2194			return -EINVAL;
2195		}
2196	}
2197
2198	/*
2199	 * Now we set the Faulty bit for those devices that are
2200	 * recorded in the superblock as failed.
2201	 */
2202	sb_retrieve_failed_devices(sb, failed_devices);
2203	rdev_for_each(r, mddev) {
2204		if (!r->sb_page)
2205			continue;
2206		sb2 = page_address(r->sb_page);
2207		sb2->failed_devices = 0;
2208		memset(sb2->extended_failed_devices, 0, sizeof(sb2->extended_failed_devices));
2209
2210		/*
2211		 * Check for any device re-ordering.
2212		 */
2213		if (!test_bit(FirstUse, &r->flags) && (r->raid_disk >= 0)) {
2214			role = le32_to_cpu(sb2->array_position);
2215			if (role < 0)
2216				continue;
2217
2218			if (role != r->raid_disk) {
2219				if (rs_is_raid10(rs) && __is_raid10_near(mddev->layout)) {
2220					if (mddev->raid_disks % __raid10_near_copies(mddev->layout) ||
2221					    rs->raid_disks % rs->raid10_copies) {
2222						rs->ti->error =
2223							"Cannot change raid10 near set to odd # of devices!";
2224						return -EINVAL;
2225					}
2226
2227					sb2->array_position = cpu_to_le32(r->raid_disk);
2228
2229				} else if (!(rs_is_raid10(rs) && rt_is_raid0(rs->raid_type)) &&
2230					   !(rs_is_raid0(rs) && rt_is_raid10(rs->raid_type)) &&
2231					   !rt_is_raid1(rs->raid_type)) {
2232					rs->ti->error = "Cannot change device positions in raid set";
2233					return -EINVAL;
2234				}
2235
2236				DMINFO("raid device #%d now at position #%d", role, r->raid_disk);
2237			}
2238
2239			/*
2240			 * Partial recovery is performed on
2241			 * returning failed devices.
2242			 */
2243			if (test_bit(role, (void *) failed_devices))
2244				set_bit(Faulty, &r->flags);
2245		}
2246	}
2247
2248	return 0;
2249}
2250
2251static int super_validate(struct raid_set *rs, struct md_rdev *rdev)
2252{
2253	struct mddev *mddev = &rs->md;
2254	struct dm_raid_superblock *sb;
2255
2256	if (rs_is_raid0(rs) || !rdev->sb_page)
2257		return 0;
2258
2259	sb = page_address(rdev->sb_page);
2260
2261	/*
2262	 * If mddev->events is not set, we know we have not yet initialized
2263	 * the array.
2264	 */
2265	if (!mddev->events && super_init_validation(rs, rdev))
2266		return -EINVAL;
2267
2268	if (le32_to_cpu(sb->compat_features) &&
2269	    le32_to_cpu(sb->compat_features) != FEATURE_FLAG_SUPPORTS_V190) {
2270		rs->ti->error = "Unable to assemble array: Unknown flag(s) in compatible feature flags";
2271		return -EINVAL;
2272	}
2273
2274	if (sb->incompat_features) {
2275		rs->ti->error = "Unable to assemble array: No incompatible feature flags supported yet";
2276		return -EINVAL;
2277	}
2278
2279	/* Enable bitmap creation for RAID levels != 0 */
2280	mddev->bitmap_info.offset = rt_is_raid0(rs->raid_type) ? 0 : to_sector(4096);
2281	rdev->mddev->bitmap_info.default_offset = mddev->bitmap_info.offset;
2282
2283	if (!test_and_clear_bit(FirstUse, &rdev->flags)) {
2284		/* Retrieve device size stored in superblock to be prepared for shrink */
2285		rdev->sectors = le64_to_cpu(sb->sectors);
2286		rdev->recovery_offset = le64_to_cpu(sb->disk_recovery_offset);
2287		if (rdev->recovery_offset == MaxSector)
2288			set_bit(In_sync, &rdev->flags);
2289		/*
2290		 * If no reshape in progress -> we're recovering single
2291		 * disk(s) and have to set the device(s) to out-of-sync
2292		 */
2293		else if (!rs_is_reshaping(rs))
2294			clear_bit(In_sync, &rdev->flags); /* Mandatory for recovery */
2295	}
2296
2297	/*
2298	 * If a device comes back, set it as not In_sync and no longer faulty.
2299	 */
2300	if (test_and_clear_bit(Faulty, &rdev->flags)) {
2301		rdev->recovery_offset = 0;
2302		clear_bit(In_sync, &rdev->flags);
2303		rdev->saved_raid_disk = rdev->raid_disk;
 
2304	}
2305
2306	/* Reshape support -> restore repective data offsets */
2307	rdev->data_offset = le64_to_cpu(sb->data_offset);
2308	rdev->new_data_offset = le64_to_cpu(sb->new_data_offset);
2309
2310	return 0;
2311}
2312
2313/*
2314 * Analyse superblocks and select the freshest.
2315 */
2316static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
2317{
2318	int r;
2319	struct raid_dev *dev;
2320	struct md_rdev *rdev, *tmp, *freshest;
2321	struct mddev *mddev = &rs->md;
2322
2323	freshest = NULL;
2324	rdev_for_each_safe(rdev, tmp, mddev) {
2325		/*
2326		 * Skipping super_load due to CTR_FLAG_SYNC will cause
2327		 * the array to undergo initialization again as
2328		 * though it were new.	This is the intended effect
2329		 * of the "sync" directive.
2330		 *
2331		 * When reshaping capability is added, we must ensure
2332		 * that the "sync" directive is disallowed during the
2333		 * reshape.
2334		 */
2335		if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags))
2336			continue;
2337
2338		if (!rdev->meta_bdev)
2339			continue;
2340
2341		r = super_load(rdev, freshest);
2342
2343		switch (r) {
2344		case 1:
2345			freshest = rdev;
2346			break;
2347		case 0:
2348			break;
2349		default:
2350			/*
2351			 * We have to keep any raid0 data/metadata device pairs or
2352			 * the MD raid0 personality will fail to start the array.
2353			 */
2354			if (rs_is_raid0(rs))
2355				continue;
2356
2357			dev = container_of(rdev, struct raid_dev, rdev);
2358			if (dev->meta_dev)
2359				dm_put_device(ti, dev->meta_dev);
2360
2361			dev->meta_dev = NULL;
2362			rdev->meta_bdev = NULL;
2363
2364			if (rdev->sb_page)
2365				put_page(rdev->sb_page);
2366
2367			rdev->sb_page = NULL;
2368
2369			rdev->sb_loaded = 0;
2370
2371			/*
2372			 * We might be able to salvage the data device
2373			 * even though the meta device has failed.  For
2374			 * now, we behave as though '- -' had been
2375			 * set for this device in the table.
2376			 */
2377			if (dev->data_dev)
2378				dm_put_device(ti, dev->data_dev);
2379
2380			dev->data_dev = NULL;
2381			rdev->bdev = NULL;
2382
2383			list_del(&rdev->same_set);
2384		}
2385	}
2386
2387	if (!freshest)
2388		return 0;
2389
2390	if (validate_raid_redundancy(rs)) {
2391		rs->ti->error = "Insufficient redundancy to activate array";
2392		return -EINVAL;
2393	}
2394
2395	/*
2396	 * Validation of the freshest device provides the source of
2397	 * validation for the remaining devices.
2398	 */
2399	rs->ti->error = "Unable to assemble array: Invalid superblocks";
2400	if (super_validate(rs, freshest))
2401		return -EINVAL;
2402
2403	rdev_for_each(rdev, mddev)
2404		if ((rdev != freshest) && super_validate(rs, rdev))
2405			return -EINVAL;
2406	return 0;
2407}
2408
2409/*
2410 * Adjust data_offset and new_data_offset on all disk members of @rs
2411 * for out of place reshaping if requested by contructor
2412 *
2413 * We need free space at the beginning of each raid disk for forward
2414 * and at the end for backward reshapes which userspace has to provide
2415 * via remapping/reordering of space.
2416 */
2417static int rs_adjust_data_offsets(struct raid_set *rs)
2418{
2419	sector_t data_offset = 0, new_data_offset = 0;
2420	struct md_rdev *rdev;
2421
2422	/* Constructor did not request data offset change */
2423	if (!test_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags)) {
2424		if (!rs_is_reshapable(rs))
2425			goto out;
2426
2427		return 0;
2428	}
2429
2430	/* HM FIXME: get InSync raid_dev? */
2431	rdev = &rs->dev[0].rdev;
2432
2433	if (rs->delta_disks < 0) {
2434		/*
2435		 * Removing disks (reshaping backwards):
2436		 *
2437		 * - before reshape: data is at offset 0 and free space
2438		 *		     is at end of each component LV
2439		 *
2440		 * - after reshape: data is at offset rs->data_offset != 0 on each component LV
2441		 */
2442		data_offset = 0;
2443		new_data_offset = rs->data_offset;
2444
2445	} else if (rs->delta_disks > 0) {
2446		/*
2447		 * Adding disks (reshaping forwards):
2448		 *
2449		 * - before reshape: data is at offset rs->data_offset != 0 and
2450		 *		     free space is at begin of each component LV
2451		 *
2452		 * - after reshape: data is at offset 0 on each component LV
2453		 */
2454		data_offset = rs->data_offset;
2455		new_data_offset = 0;
2456
2457	} else {
2458		/*
2459		 * User space passes in 0 for data offset after having removed reshape space
2460		 *
2461		 * - or - (data offset != 0)
2462		 *
2463		 * Changing RAID layout or chunk size -> toggle offsets
2464		 *
2465		 * - before reshape: data is at offset rs->data_offset 0 and
2466		 *		     free space is at end of each component LV
2467		 *		     -or-
2468		 *                   data is at offset rs->data_offset != 0 and
2469		 *		     free space is at begin of each component LV
2470		 *
2471		 * - after reshape: data is at offset 0 if it was at offset != 0
2472		 *                  or at offset != 0 if it was at offset 0
2473		 *                  on each component LV
2474		 *
2475		 */
2476		data_offset = rs->data_offset ? rdev->data_offset : 0;
2477		new_data_offset = data_offset ? 0 : rs->data_offset;
2478		set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2479	}
2480
2481	/*
2482	 * Make sure we got a minimum amount of free sectors per device
2483	 */
2484	if (rs->data_offset &&
2485	    to_sector(i_size_read(rdev->bdev->bd_inode)) - rdev->sectors < MIN_FREE_RESHAPE_SPACE) {
2486		rs->ti->error = data_offset ? "No space for forward reshape" :
2487					      "No space for backward reshape";
2488		return -ENOSPC;
2489	}
2490out:
2491	/* Adjust data offsets on all rdevs */
2492	rdev_for_each(rdev, &rs->md) {
2493		rdev->data_offset = data_offset;
2494		rdev->new_data_offset = new_data_offset;
2495	}
2496
2497	return 0;
2498}
2499
2500/* Userpace reordered disks -> adjust raid_disk indexes in @rs */
2501static void __reorder_raid_disk_indexes(struct raid_set *rs)
2502{
2503	int i = 0;
2504	struct md_rdev *rdev;
2505
2506	rdev_for_each(rdev, &rs->md) {
2507		rdev->raid_disk = i++;
2508		rdev->saved_raid_disk = rdev->new_raid_disk = -1;
2509	}
2510}
2511
2512/*
2513 * Setup @rs for takeover by a different raid level
2514 */
2515static int rs_setup_takeover(struct raid_set *rs)
2516{
2517	struct mddev *mddev = &rs->md;
2518	struct md_rdev *rdev;
2519	unsigned int d = mddev->raid_disks = rs->raid_disks;
2520	sector_t new_data_offset = rs->dev[0].rdev.data_offset ? 0 : rs->data_offset;
2521
2522	if (rt_is_raid10(rs->raid_type)) {
2523		if (mddev->level == 0) {
2524			/* Userpace reordered disks -> adjust raid_disk indexes */
2525			__reorder_raid_disk_indexes(rs);
2526
2527			/* raid0 -> raid10_far layout */
2528			mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_FAR,
2529								   rs->raid10_copies);
2530		} else if (mddev->level == 1)
2531			/* raid1 -> raid10_near layout */
2532			mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_NEAR,
2533								   rs->raid_disks);
2534		else
2535			return -EINVAL;
2536
2537	}
2538
2539	clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
2540	mddev->recovery_cp = MaxSector;
2541
2542	while (d--) {
2543		rdev = &rs->dev[d].rdev;
2544
2545		if (test_bit(d, (void *) rs->rebuild_disks)) {
2546			clear_bit(In_sync, &rdev->flags);
2547			clear_bit(Faulty, &rdev->flags);
2548			mddev->recovery_cp = rdev->recovery_offset = 0;
2549			/* Bitmap has to be created when we do an "up" takeover */
2550			set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
2551		}
2552
2553		rdev->new_data_offset = new_data_offset;
2554	}
2555
2556	return 0;
2557}
2558
2559/* Prepare @rs for reshape */
2560static int rs_prepare_reshape(struct raid_set *rs)
2561{
2562	bool reshape;
2563	struct mddev *mddev = &rs->md;
2564
2565	if (rs_is_raid10(rs)) {
2566		if (rs->raid_disks != mddev->raid_disks &&
2567		    __is_raid10_near(mddev->layout) &&
2568		    rs->raid10_copies &&
2569		    rs->raid10_copies != __raid10_near_copies(mddev->layout)) {
2570			/*
2571			 * raid disk have to be multiple of data copies to allow this conversion,
2572			 *
2573			 * This is actually not a reshape it is a
2574			 * rebuild of any additional mirrors per group
2575			 */
2576			if (rs->raid_disks % rs->raid10_copies) {
2577				rs->ti->error = "Can't reshape raid10 mirror groups";
2578				return -EINVAL;
2579			}
2580
2581			/* Userpace reordered disks to add/remove mirrors -> adjust raid_disk indexes */
2582			__reorder_raid_disk_indexes(rs);
2583			mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_NEAR,
2584								   rs->raid10_copies);
2585			mddev->new_layout = mddev->layout;
2586			reshape = false;
2587		} else
2588			reshape = true;
2589
2590	} else if (rs_is_raid456(rs))
2591		reshape = true;
2592
2593	else if (rs_is_raid1(rs)) {
2594		if (rs->delta_disks) {
2595			/* Process raid1 via delta_disks */
2596			mddev->degraded = rs->delta_disks < 0 ? -rs->delta_disks : rs->delta_disks;
2597			reshape = true;
2598		} else {
2599			/* Process raid1 without delta_disks */
2600			mddev->raid_disks = rs->raid_disks;
2601			reshape = false;
2602		}
2603	} else {
2604		rs->ti->error = "Called with bogus raid type";
2605		return -EINVAL;
2606	}
2607
2608	if (reshape) {
2609		set_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags);
2610		set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2611	} else if (mddev->raid_disks < rs->raid_disks)
2612		/* Create new superblocks and bitmaps, if any new disks */
2613		set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2614
2615	return 0;
2616}
2617
2618/*
2619 *
2620 * - change raid layout
2621 * - change chunk size
2622 * - add disks
2623 * - remove disks
2624 */
2625static int rs_setup_reshape(struct raid_set *rs)
2626{
2627	int r = 0;
2628	unsigned int cur_raid_devs, d;
2629	struct mddev *mddev = &rs->md;
2630	struct md_rdev *rdev;
2631
2632	mddev->delta_disks = rs->delta_disks;
2633	cur_raid_devs = mddev->raid_disks;
2634
2635	/* Ignore impossible layout change whilst adding/removing disks */
2636	if (mddev->delta_disks &&
2637	    mddev->layout != mddev->new_layout) {
2638		DMINFO("Ignoring invalid layout change with delta_disks=%d", rs->delta_disks);
2639		mddev->new_layout = mddev->layout;
2640	}
2641
2642	/*
2643	 * Adjust array size:
2644	 *
2645	 * - in case of adding disks, array size has
2646	 *   to grow after the disk adding reshape,
2647	 *   which'll hapen in the event handler;
2648	 *   reshape will happen forward, so space has to
2649	 *   be available at the beginning of each disk
2650	 *
2651	 * - in case of removing disks, array size
2652	 *   has to shrink before starting the reshape,
2653	 *   which'll happen here;
2654	 *   reshape will happen backward, so space has to
2655	 *   be available at the end of each disk
2656	 *
2657	 * - data_offset and new_data_offset are
2658	 *   adjusted for aforementioned out of place
2659	 *   reshaping based on userspace passing in
2660	 *   the "data_offset <sectors>" key/value
2661	 *   pair via the constructor
2662	 */
2663
2664	/* Add disk(s) */
2665	if (rs->delta_disks > 0) {
2666		/* Prepare disks for check in raid4/5/6/10 {check|start}_reshape */
2667		for (d = cur_raid_devs; d < rs->raid_disks; d++) {
2668			rdev = &rs->dev[d].rdev;
2669			clear_bit(In_sync, &rdev->flags);
2670
2671			/*
2672			 * save_raid_disk needs to be -1, or recovery_offset will be set to 0
2673			 * by md, which'll store that erroneously in the superblock on reshape
2674			 */
2675			rdev->saved_raid_disk = -1;
2676			rdev->raid_disk = d;
2677
2678			rdev->sectors = mddev->dev_sectors;
2679			rdev->recovery_offset = rs_is_raid1(rs) ? 0 : MaxSector;
2680		}
2681
2682		mddev->reshape_backwards = 0; /* adding disks -> forward reshape */
2683
2684	/* Remove disk(s) */
2685	} else if (rs->delta_disks < 0) {
2686		r = rs_set_dev_and_array_sectors(rs, true);
2687		mddev->reshape_backwards = 1; /* removing disk(s) -> backward reshape */
2688
2689	/* Change layout and/or chunk size */
2690	} else {
2691		/*
2692		 * Reshape layout (e.g. raid5_ls -> raid5_n) and/or chunk size:
2693		 *
2694		 * keeping number of disks and do layout change ->
2695		 *
2696		 * toggle reshape_backward depending on data_offset:
2697		 *
2698		 * - free space upfront -> reshape forward
2699		 *
2700		 * - free space at the end -> reshape backward
2701		 *
2702		 *
2703		 * This utilizes free reshape space avoiding the need
2704		 * for userspace to move (parts of) LV segments in
2705		 * case of layout/chunksize change  (for disk
2706		 * adding/removing reshape space has to be at
2707		 * the proper address (see above with delta_disks):
2708		 *
2709		 * add disk(s)   -> begin
2710		 * remove disk(s)-> end
2711		 */
2712		mddev->reshape_backwards = rs->dev[0].rdev.data_offset ? 0 : 1;
2713	}
2714
2715	return r;
2716}
2717
2718/*
2719 * Enable/disable discard support on RAID set depending on
2720 * RAID level and discard properties of underlying RAID members.
2721 */
2722static void configure_discard_support(struct raid_set *rs)
2723{
2724	int i;
2725	bool raid456;
2726	struct dm_target *ti = rs->ti;
2727
2728	/* Assume discards not supported until after checks below. */
2729	ti->discards_supported = false;
2730
2731	/* RAID level 4,5,6 require discard_zeroes_data for data integrity! */
2732	raid456 = (rs->md.level == 4 || rs->md.level == 5 || rs->md.level == 6);
2733
2734	for (i = 0; i < rs->raid_disks; i++) {
2735		struct request_queue *q;
2736
2737		if (!rs->dev[i].rdev.bdev)
2738			continue;
2739
2740		q = bdev_get_queue(rs->dev[i].rdev.bdev);
2741		if (!q || !blk_queue_discard(q))
2742			return;
2743
2744		if (raid456) {
2745			if (!q->limits.discard_zeroes_data)
2746				return;
2747			if (!devices_handle_discard_safely) {
2748				DMERR("raid456 discard support disabled due to discard_zeroes_data uncertainty.");
2749				DMERR("Set dm-raid.devices_handle_discard_safely=Y to override.");
2750				return;
2751			}
2752		}
2753	}
2754
2755	/* All RAID members properly support discards */
2756	ti->discards_supported = true;
2757
2758	/*
2759	 * RAID1 and RAID10 personalities require bio splitting,
2760	 * RAID0/4/5/6 don't and process large discard bios properly.
2761	 */
2762	ti->split_discard_bios = !!(rs->md.level == 1 || rs->md.level == 10);
2763	ti->num_discard_bios = 1;
2764}
2765
2766/*
2767 * Construct a RAID0/1/10/4/5/6 mapping:
2768 * Args:
2769 *	<raid_type> <#raid_params> <raid_params>{0,}	\
2770 *	<#raid_devs> [<meta_dev1> <dev1>]{1,}
2771 *
2772 * <raid_params> varies by <raid_type>.	 See 'parse_raid_params' for
2773 * details on possible <raid_params>.
2774 *
2775 * Userspace is free to initialize the metadata devices, hence the superblocks to
2776 * enforce recreation based on the passed in table parameters.
2777 *
2778 */
2779static int raid_ctr(struct dm_target *ti, unsigned int argc, char **argv)
2780{
2781	int r;
2782	bool resize;
2783	struct raid_type *rt;
2784	unsigned int num_raid_params, num_raid_devs;
2785	sector_t calculated_dev_sectors;
2786	struct raid_set *rs = NULL;
2787	const char *arg;
2788	struct rs_layout rs_layout;
2789	struct dm_arg_set as = { argc, argv }, as_nrd;
2790	struct dm_arg _args[] = {
2791		{ 0, as.argc, "Cannot understand number of raid parameters" },
2792		{ 1, 254, "Cannot understand number of raid devices parameters" }
2793	};
2794
2795	/* Must have <raid_type> */
2796	arg = dm_shift_arg(&as);
2797	if (!arg) {
2798		ti->error = "No arguments";
2799		return -EINVAL;
2800	}
2801
2802	rt = get_raid_type(arg);
 
2803	if (!rt) {
2804		ti->error = "Unrecognised raid_type";
2805		return -EINVAL;
2806	}
 
 
2807
2808	/* Must have <#raid_params> */
2809	if (dm_read_arg_group(_args, &as, &num_raid_params, &ti->error))
 
2810		return -EINVAL;
 
 
 
2811
2812	/* number of raid device tupples <meta_dev data_dev> */
2813	as_nrd = as;
2814	dm_consume_args(&as_nrd, num_raid_params);
2815	_args[1].max = (as_nrd.argc - 1) / 2;
2816	if (dm_read_arg(_args + 1, &as_nrd, &num_raid_devs, &ti->error))
2817		return -EINVAL;
 
2818
2819	if (!__within_range(num_raid_devs, 1, MAX_RAID_DEVICES)) {
2820		ti->error = "Invalid number of supplied raid devices";
 
2821		return -EINVAL;
2822	}
2823
2824	rs = raid_set_alloc(ti, rt, num_raid_devs);
2825	if (IS_ERR(rs))
2826		return PTR_ERR(rs);
2827
2828	r = parse_raid_params(rs, &as, num_raid_params);
2829	if (r)
2830		goto bad;
2831
2832	r = parse_dev_params(rs, &as);
2833	if (r)
2834		goto bad;
2835
2836	rs->md.sync_super = super_sync;
 
2837
2838	/*
2839	 * Calculate ctr requested array and device sizes to allow
2840	 * for superblock analysis needing device sizes defined.
2841	 *
2842	 * Any existing superblock will overwrite the array and device sizes
2843	 */
2844	r = rs_set_dev_and_array_sectors(rs, false);
2845	if (r)
2846		goto bad;
 
2847
2848	calculated_dev_sectors = rs->dev[0].rdev.sectors;
 
 
2849
2850	/*
2851	 * Backup any new raid set level, layout, ...
2852	 * requested to be able to compare to superblock
2853	 * members for conversion decisions.
2854	 */
2855	rs_config_backup(rs, &rs_layout);
2856
2857	r = analyse_superblocks(ti, rs);
2858	if (r)
2859		goto bad;
2860
2861	resize = calculated_dev_sectors != rs->dev[0].rdev.sectors;
2862
2863	INIT_WORK(&rs->md.event_work, do_table_event);
2864	ti->private = rs;
2865	ti->num_flush_bios = 1;
2866
2867	/* Restore any requested new layout for conversion decision */
2868	rs_config_restore(rs, &rs_layout);
2869
2870	/*
2871	 * Now that we have any superblock metadata available,
2872	 * check for new, recovering, reshaping, to be taken over,
2873	 * to be reshaped or an existing, unchanged raid set to
2874	 * run in sequence.
2875	 */
2876	if (test_bit(MD_ARRAY_FIRST_USE, &rs->md.flags)) {
2877		/* A new raid6 set has to be recovered to ensure proper parity and Q-Syndrome */
2878		if (rs_is_raid6(rs) &&
2879		    test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
2880			ti->error = "'nosync' not allowed for new raid6 set";
2881			r = -EINVAL;
2882			goto bad;
2883		}
2884		rs_setup_recovery(rs, 0);
2885		set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2886		rs_set_new(rs);
2887	} else if (rs_is_recovering(rs)) {
2888		/* A recovering raid set may be resized */
2889		; /* skip setup rs */
2890	} else if (rs_is_reshaping(rs)) {
2891		/* Have to reject size change request during reshape */
2892		if (resize) {
2893			ti->error = "Can't resize a reshaping raid set";
2894			r = -EPERM;
2895			goto bad;
2896		}
2897		/* skip setup rs */
2898	} else if (rs_takeover_requested(rs)) {
2899		if (rs_is_reshaping(rs)) {
2900			ti->error = "Can't takeover a reshaping raid set";
2901			r = -EPERM;
2902			goto bad;
2903		}
2904
2905		/*
2906		 * If a takeover is needed, userspace sets any additional
2907		 * devices to rebuild and we can check for a valid request here.
2908		 *
2909		 * If acceptible, set the level to the new requested
2910		 * one, prohibit requesting recovery, allow the raid
2911		 * set to run and store superblocks during resume.
2912		 */
2913		r = rs_check_takeover(rs);
2914		if (r)
2915			goto bad;
2916
2917		r = rs_setup_takeover(rs);
2918		if (r)
2919			goto bad;
2920
2921		set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2922		/* Takeover ain't recovery, so disable recovery */
2923		rs_setup_recovery(rs, MaxSector);
2924		rs_set_new(rs);
2925	} else if (rs_reshape_requested(rs)) {
2926		/*
2927		  * We can only prepare for a reshape here, because the
2928		  * raid set needs to run to provide the repective reshape
2929		  * check functions via its MD personality instance.
2930		  *
2931		  * So do the reshape check after md_run() succeeded.
2932		  */
2933		r = rs_prepare_reshape(rs);
2934		if (r)
2935			return r;
2936
2937		/* Reshaping ain't recovery, so disable recovery */
2938		rs_setup_recovery(rs, MaxSector);
2939		rs_set_cur(rs);
2940	} else {
2941		/* May not set recovery when a device rebuild is requested */
2942		if (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags)) {
2943			rs_setup_recovery(rs, MaxSector);
2944			set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2945		} else
2946			rs_setup_recovery(rs, test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags) ?
2947					      0 : (resize ? calculated_dev_sectors : MaxSector));
2948		rs_set_cur(rs);
2949	}
2950
2951	/* If constructor requested it, change data and new_data offsets */
2952	r = rs_adjust_data_offsets(rs);
2953	if (r)
2954		goto bad;
2955
2956	/* Start raid set read-only and assumed clean to change in raid_resume() */
2957	rs->md.ro = 1;
2958	rs->md.in_sync = 1;
2959	set_bit(MD_RECOVERY_FROZEN, &rs->md.recovery);
2960
2961	/* Has to be held on running the array */
2962	mddev_lock_nointr(&rs->md);
2963	r = md_run(&rs->md);
2964	rs->md.in_sync = 0; /* Assume already marked dirty */
 
2965
2966	if (r) {
2967		ti->error = "Failed to run raid array";
2968		mddev_unlock(&rs->md);
2969		goto bad;
2970	}
2971
2972	rs->callbacks.congested_fn = raid_is_congested;
2973	dm_table_add_target_callbacks(ti->table, &rs->callbacks);
2974
2975	mddev_suspend(&rs->md);
2976
2977	/* Try to adjust the raid4/5/6 stripe cache size to the stripe size */
2978	if (rs_is_raid456(rs)) {
2979		r = rs_set_raid456_stripe_cache(rs);
2980		if (r)
2981			goto bad_stripe_cache;
2982	}
2983
2984	/* Now do an early reshape check */
2985	if (test_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags)) {
2986		r = rs_check_reshape(rs);
2987		if (r)
2988			goto bad_check_reshape;
2989
2990		/* Restore new, ctr requested layout to perform check */
2991		rs_config_restore(rs, &rs_layout);
2992
2993		if (rs->md.pers->start_reshape) {
2994			r = rs->md.pers->check_reshape(&rs->md);
2995			if (r) {
2996				ti->error = "Reshape check failed";
2997				goto bad_check_reshape;
2998			}
2999		}
3000	}
3001
3002	/* Disable/enable discard support on raid set. */
3003	configure_discard_support(rs);
3004
3005	mddev_unlock(&rs->md);
3006	return 0;
3007
3008bad_stripe_cache:
3009bad_check_reshape:
3010	md_stop(&rs->md);
3011bad:
3012	raid_set_free(rs);
3013
3014	return r;
3015}
3016
3017static void raid_dtr(struct dm_target *ti)
3018{
3019	struct raid_set *rs = ti->private;
3020
3021	list_del_init(&rs->callbacks.list);
3022	md_stop(&rs->md);
3023	raid_set_free(rs);
3024}
3025
3026static int raid_map(struct dm_target *ti, struct bio *bio)
3027{
3028	struct raid_set *rs = ti->private;
3029	struct mddev *mddev = &rs->md;
3030
3031	/*
3032	 * If we're reshaping to add disk(s)), ti->len and
3033	 * mddev->array_sectors will differ during the process
3034	 * (ti->len > mddev->array_sectors), so we have to requeue
3035	 * bios with addresses > mddev->array_sectors here or
3036	 * there will occur accesses past EOD of the component
3037	 * data images thus erroring the raid set.
3038	 */
3039	if (unlikely(bio_end_sector(bio) > mddev->array_sectors))
3040		return DM_MAPIO_REQUEUE;
3041
3042	mddev->pers->make_request(mddev, bio);
3043
3044	return DM_MAPIO_SUBMITTED;
3045}
3046
3047/* Return string describing the current sync action of @mddev */
3048static const char *decipher_sync_action(struct mddev *mddev)
3049{
3050	if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
3051		return "frozen";
 
 
 
3052
3053	if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
3054	    (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))) {
3055		if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
3056			return "reshape";
3057
3058		if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
3059			if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
3060				return "resync";
3061			else if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
3062				return "check";
3063			return "repair";
 
3064		}
3065
3066		if (test_bit(MD_RECOVERY_RECOVER, &mddev->recovery))
3067			return "recover";
3068	}
3069
3070	return "idle";
3071}
3072
3073/*
3074 * Return status string @rdev
3075 *
3076 * Status characters:
3077 *
3078 *  'D' = Dead/Failed device
3079 *  'a' = Alive but not in-sync
3080 *  'A' = Alive and in-sync
3081 */
3082static const char *__raid_dev_status(struct md_rdev *rdev, bool array_in_sync)
3083{
3084	if (test_bit(Faulty, &rdev->flags))
3085		return "D";
3086	else if (!array_in_sync || !test_bit(In_sync, &rdev->flags))
3087		return "a";
3088	else
3089		return "A";
3090}
3091
3092/* Helper to return resync/reshape progress for @rs and @array_in_sync */
3093static sector_t rs_get_progress(struct raid_set *rs,
3094				sector_t resync_max_sectors, bool *array_in_sync)
3095{
3096	sector_t r, recovery_cp, curr_resync_completed;
3097	struct mddev *mddev = &rs->md;
3098
3099	curr_resync_completed = mddev->curr_resync_completed ?: mddev->recovery_cp;
3100	recovery_cp = mddev->recovery_cp;
3101	*array_in_sync = false;
3102
3103	if (rs_is_raid0(rs)) {
3104		r = resync_max_sectors;
3105		*array_in_sync = true;
3106
3107	} else {
3108		r = mddev->reshape_position;
3109
3110		/* Reshape is relative to the array size */
3111		if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery) ||
3112		    r != MaxSector) {
3113			if (r == MaxSector) {
3114				*array_in_sync = true;
3115				r = resync_max_sectors;
3116			} else {
3117				/* Got to reverse on backward reshape */
3118				if (mddev->reshape_backwards)
3119					r = mddev->array_sectors - r;
3120
3121				/* Devide by # of data stripes */
3122				sector_div(r, mddev_data_stripes(rs));
3123			}
3124
3125		/* Sync is relative to the component device size */
3126		} else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery))
3127			r = curr_resync_completed;
3128		else
3129			r = recovery_cp;
3130
3131		if (r == MaxSector) {
3132			/*
3133			 * Sync complete.
3134			 */
3135			*array_in_sync = true;
3136			r = resync_max_sectors;
3137		} else if (test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery)) {
3138			/*
3139			 * If "check" or "repair" is occurring, the raid set has
3140			 * undergone an initial sync and the health characters
3141			 * should not be 'a' anymore.
3142			 */
3143			*array_in_sync = true;
3144		} else {
3145			struct md_rdev *rdev;
3146
3147			/*
3148			 * The raid set may be doing an initial sync, or it may
3149			 * be rebuilding individual components.	 If all the
3150			 * devices are In_sync, then it is the raid set that is
3151			 * being initialized.
3152			 */
3153			rdev_for_each(rdev, mddev)
3154				if (!test_bit(In_sync, &rdev->flags))
3155					*array_in_sync = true;
3156#if 0
3157			r = 0; /* HM FIXME: TESTME: https://bugzilla.redhat.com/show_bug.cgi?id=1210637 ? */
3158#endif
3159		}
3160	}
3161
3162	return r;
3163}
3164
3165/* Helper to return @dev name or "-" if !@dev */
3166static const char *__get_dev_name(struct dm_dev *dev)
3167{
3168	return dev ? dev->name : "-";
3169}
3170
3171static void raid_status(struct dm_target *ti, status_type_t type,
3172			unsigned int status_flags, char *result, unsigned int maxlen)
3173{
3174	struct raid_set *rs = ti->private;
3175	struct mddev *mddev = &rs->md;
3176	struct r5conf *conf = mddev->private;
3177	int i, max_nr_stripes = conf ? conf->max_nr_stripes : 0;
3178	bool array_in_sync;
3179	unsigned int raid_param_cnt = 1; /* at least 1 for chunksize */
3180	unsigned int sz = 0;
3181	unsigned int rebuild_disks;
3182	unsigned int write_mostly_params = 0;
3183	sector_t progress, resync_max_sectors, resync_mismatches;
3184	const char *sync_action;
3185	struct raid_type *rt;
3186	struct md_rdev *rdev;
3187
3188	switch (type) {
3189	case STATUSTYPE_INFO:
3190		/* *Should* always succeed */
3191		rt = get_raid_type_by_ll(mddev->new_level, mddev->new_layout);
3192		if (!rt)
3193			return;
3194
3195		DMEMIT("%s %d ", rt->name, mddev->raid_disks);
3196
3197		/* Access most recent mddev properties for status output */
3198		smp_rmb();
3199		/* Get sensible max sectors even if raid set not yet started */
3200		resync_max_sectors = test_bit(RT_FLAG_RS_PRERESUMED, &rs->runtime_flags) ?
3201				      mddev->resync_max_sectors : mddev->dev_sectors;
3202		progress = rs_get_progress(rs, resync_max_sectors, &array_in_sync);
3203		resync_mismatches = (mddev->last_sync_action && !strcasecmp(mddev->last_sync_action, "check")) ?
3204				    atomic64_read(&mddev->resync_mismatches) : 0;
3205		sync_action = decipher_sync_action(&rs->md);
3206
3207		/* HM FIXME: do we want another state char for raid0? It shows 'D' or 'A' now */
3208		rdev_for_each(rdev, mddev)
3209			DMEMIT(__raid_dev_status(rdev, array_in_sync));
3210
3211		/*
3212		 * In-sync/Reshape ratio:
3213		 *  The in-sync ratio shows the progress of:
3214		 *   - Initializing the raid set
3215		 *   - Rebuilding a subset of devices of the raid set
3216		 *  The user can distinguish between the two by referring
3217		 *  to the status characters.
3218		 *
3219		 *  The reshape ratio shows the progress of
3220		 *  changing the raid layout or the number of
3221		 *  disks of a raid set
3222		 */
3223		DMEMIT(" %llu/%llu", (unsigned long long) progress,
3224				     (unsigned long long) resync_max_sectors);
3225
3226		/*
3227		 * v1.5.0+:
3228		 *
3229		 * Sync action:
3230		 *   See Documentation/device-mapper/dm-raid.txt for
3231		 *   information on each of these states.
3232		 */
3233		DMEMIT(" %s", sync_action);
3234
3235		/*
3236		 * v1.5.0+:
3237		 *
3238		 * resync_mismatches/mismatch_cnt
3239		 *   This field shows the number of discrepancies found when
3240		 *   performing a "check" of the raid set.
3241		 */
3242		DMEMIT(" %llu", (unsigned long long) resync_mismatches);
3243
3244		/*
3245		 * v1.9.0+:
3246		 *
3247		 * data_offset (needed for out of space reshaping)
3248		 *   This field shows the data offset into the data
3249		 *   image LV where the first stripes data starts.
3250		 *
3251		 * We keep data_offset equal on all raid disks of the set,
3252		 * so retrieving it from the first raid disk is sufficient.
3253		 */
3254		DMEMIT(" %llu", (unsigned long long) rs->dev[0].rdev.data_offset);
3255		break;
3256
3257	case STATUSTYPE_TABLE:
3258		/* Report the table line string you would use to construct this raid set */
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3259
3260		/* Calculate raid parameter count */
3261		for (i = 0; i < rs->raid_disks; i++)
3262			if (test_bit(WriteMostly, &rs->dev[i].rdev.flags))
3263				write_mostly_params += 2;
3264		rebuild_disks = memweight(rs->rebuild_disks, DISKS_ARRAY_ELEMS * sizeof(*rs->rebuild_disks));
3265		raid_param_cnt += rebuild_disks * 2 +
3266				  write_mostly_params +
3267				  hweight32(rs->ctr_flags & CTR_FLAG_OPTIONS_NO_ARGS) +
3268				  hweight32(rs->ctr_flags & CTR_FLAG_OPTIONS_ONE_ARG) * 2;
3269		/* Emit table line */
3270		DMEMIT("%s %u %u", rs->raid_type->name, raid_param_cnt, mddev->new_chunk_sectors);
3271		if (test_bit(__CTR_FLAG_RAID10_FORMAT, &rs->ctr_flags))
3272			DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_FORMAT),
3273					 raid10_md_layout_to_format(mddev->layout));
3274		if (test_bit(__CTR_FLAG_RAID10_COPIES, &rs->ctr_flags))
3275			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_COPIES),
3276					 raid10_md_layout_to_copies(mddev->layout));
3277		if (test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))
3278			DMEMIT(" %s", dm_raid_arg_name_by_flag(CTR_FLAG_NOSYNC));
3279		if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags))
3280			DMEMIT(" %s", dm_raid_arg_name_by_flag(CTR_FLAG_SYNC));
3281		if (test_bit(__CTR_FLAG_REGION_SIZE, &rs->ctr_flags))
3282			DMEMIT(" %s %llu", dm_raid_arg_name_by_flag(CTR_FLAG_REGION_SIZE),
3283					   (unsigned long long) to_sector(mddev->bitmap_info.chunksize));
3284		if (test_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags))
3285			DMEMIT(" %s %llu", dm_raid_arg_name_by_flag(CTR_FLAG_DATA_OFFSET),
3286					   (unsigned long long) rs->data_offset);
3287		if (test_bit(__CTR_FLAG_DAEMON_SLEEP, &rs->ctr_flags))
3288			DMEMIT(" %s %lu", dm_raid_arg_name_by_flag(CTR_FLAG_DAEMON_SLEEP),
3289					  mddev->bitmap_info.daemon_sleep);
3290		if (test_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags))
3291			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_DELTA_DISKS),
3292					 max(rs->delta_disks, mddev->delta_disks));
3293		if (test_bit(__CTR_FLAG_STRIPE_CACHE, &rs->ctr_flags))
3294			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_STRIPE_CACHE),
3295					 max_nr_stripes);
3296		if (rebuild_disks)
3297			for (i = 0; i < rs->raid_disks; i++)
3298				if (test_bit(rs->dev[i].rdev.raid_disk, (void *) rs->rebuild_disks))
3299					DMEMIT(" %s %u", dm_raid_arg_name_by_flag(CTR_FLAG_REBUILD),
3300							 rs->dev[i].rdev.raid_disk);
3301		if (write_mostly_params)
3302			for (i = 0; i < rs->raid_disks; i++)
3303				if (test_bit(WriteMostly, &rs->dev[i].rdev.flags))
3304					DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_WRITE_MOSTLY),
3305					       rs->dev[i].rdev.raid_disk);
3306		if (test_bit(__CTR_FLAG_MAX_WRITE_BEHIND, &rs->ctr_flags))
3307			DMEMIT(" %s %lu", dm_raid_arg_name_by_flag(CTR_FLAG_MAX_WRITE_BEHIND),
3308					  mddev->bitmap_info.max_write_behind);
3309		if (test_bit(__CTR_FLAG_MAX_RECOVERY_RATE, &rs->ctr_flags))
3310			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_MAX_RECOVERY_RATE),
3311					 mddev->sync_speed_max);
3312		if (test_bit(__CTR_FLAG_MIN_RECOVERY_RATE, &rs->ctr_flags))
3313			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_MIN_RECOVERY_RATE),
3314					 mddev->sync_speed_min);
3315		DMEMIT(" %d", rs->raid_disks);
3316		for (i = 0; i < rs->raid_disks; i++)
3317			DMEMIT(" %s %s", __get_dev_name(rs->dev[i].meta_dev),
3318					 __get_dev_name(rs->dev[i].data_dev));
3319	}
3320}
3321
3322static int raid_message(struct dm_target *ti, unsigned int argc, char **argv)
3323{
3324	struct raid_set *rs = ti->private;
3325	struct mddev *mddev = &rs->md;
3326
3327	if (!mddev->pers || !mddev->pers->sync_request)
3328		return -EINVAL;
3329
3330	if (!strcasecmp(argv[0], "frozen"))
3331		set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3332	else
3333		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3334
3335	if (!strcasecmp(argv[0], "idle") || !strcasecmp(argv[0], "frozen")) {
3336		if (mddev->sync_thread) {
3337			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
3338			md_reap_sync_thread(mddev);
3339		}
3340	} else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
3341		   test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
3342		return -EBUSY;
3343	else if (!strcasecmp(argv[0], "resync"))
3344		; /* MD_RECOVERY_NEEDED set below */
3345	else if (!strcasecmp(argv[0], "recover"))
3346		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
3347	else {
3348		if (!strcasecmp(argv[0], "check"))
3349			set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
3350		else if (!!strcasecmp(argv[0], "repair"))
3351			return -EINVAL;
3352		set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
3353		set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3354	}
3355	if (mddev->ro == 2) {
3356		/* A write to sync_action is enough to justify
3357		 * canceling read-auto mode
3358		 */
3359		mddev->ro = 0;
3360		if (!mddev->suspended && mddev->sync_thread)
3361			md_wakeup_thread(mddev->sync_thread);
3362	}
3363	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3364	if (!mddev->suspended && mddev->thread)
3365		md_wakeup_thread(mddev->thread);
3366
3367	return 0;
3368}
3369
3370static int raid_iterate_devices(struct dm_target *ti,
3371				iterate_devices_callout_fn fn, void *data)
3372{
3373	struct raid_set *rs = ti->private;
3374	unsigned int i;
3375	int r = 0;
3376
3377	for (i = 0; !r && i < rs->md.raid_disks; i++)
3378		if (rs->dev[i].data_dev)
3379			r = fn(ti,
3380				 rs->dev[i].data_dev,
3381				 0, /* No offset on data devs */
3382				 rs->md.dev_sectors,
3383				 data);
3384
3385	return r;
3386}
3387
3388static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
3389{
3390	struct raid_set *rs = ti->private;
3391	unsigned int chunk_size = to_bytes(rs->md.chunk_sectors);
 
3392
3393	blk_limits_io_min(limits, chunk_size);
3394	blk_limits_io_opt(limits, chunk_size * mddev_data_stripes(rs));
3395}
3396
3397static void raid_presuspend(struct dm_target *ti)
3398{
3399	struct raid_set *rs = ti->private;
3400
3401	md_stop_writes(&rs->md);
3402}
3403
3404static void raid_postsuspend(struct dm_target *ti)
3405{
3406	struct raid_set *rs = ti->private;
3407
3408	if (!rs->md.suspended)
3409		mddev_suspend(&rs->md);
3410
3411	rs->md.ro = 1;
3412}
3413
3414static void attempt_restore_of_faulty_devices(struct raid_set *rs)
3415{
3416	int i;
3417	uint64_t cleared_failed_devices[DISKS_ARRAY_ELEMS];
3418	unsigned long flags;
3419	bool cleared = false;
3420	struct dm_raid_superblock *sb;
3421	struct mddev *mddev = &rs->md;
3422	struct md_rdev *r;
3423
3424	/* RAID personalities have to provide hot add/remove methods or we need to bail out. */
3425	if (!mddev->pers || !mddev->pers->hot_add_disk || !mddev->pers->hot_remove_disk)
3426		return;
3427
3428	memset(cleared_failed_devices, 0, sizeof(cleared_failed_devices));
3429
3430	for (i = 0; i < rs->md.raid_disks; i++) {
3431		r = &rs->dev[i].rdev;
3432		if (test_bit(Faulty, &r->flags) && r->sb_page &&
3433		    sync_page_io(r, 0, r->sb_size, r->sb_page,
3434				 REQ_OP_READ, 0, true)) {
3435			DMINFO("Faulty %s device #%d has readable super block."
3436			       "  Attempting to revive it.",
3437			       rs->raid_type->name, i);
3438
3439			/*
3440			 * Faulty bit may be set, but sometimes the array can
3441			 * be suspended before the personalities can respond
3442			 * by removing the device from the array (i.e. calling
3443			 * 'hot_remove_disk').	If they haven't yet removed
3444			 * the failed device, its 'raid_disk' number will be
3445			 * '>= 0' - meaning we must call this function
3446			 * ourselves.
3447			 */
3448			if ((r->raid_disk >= 0) &&
3449			    (mddev->pers->hot_remove_disk(mddev, r) != 0))
3450				/* Failed to revive this device, try next */
3451				continue;
3452
3453			r->raid_disk = i;
3454			r->saved_raid_disk = i;
3455			flags = r->flags;
3456			clear_bit(Faulty, &r->flags);
3457			clear_bit(WriteErrorSeen, &r->flags);
3458			clear_bit(In_sync, &r->flags);
3459			if (mddev->pers->hot_add_disk(mddev, r)) {
3460				r->raid_disk = -1;
3461				r->saved_raid_disk = -1;
3462				r->flags = flags;
3463			} else {
3464				r->recovery_offset = 0;
3465				set_bit(i, (void *) cleared_failed_devices);
3466				cleared = true;
3467			}
3468		}
3469	}
3470
3471	/* If any failed devices could be cleared, update all sbs failed_devices bits */
3472	if (cleared) {
3473		uint64_t failed_devices[DISKS_ARRAY_ELEMS];
3474
3475		rdev_for_each(r, &rs->md) {
3476			sb = page_address(r->sb_page);
3477			sb_retrieve_failed_devices(sb, failed_devices);
3478
3479			for (i = 0; i < DISKS_ARRAY_ELEMS; i++)
3480				failed_devices[i] &= ~cleared_failed_devices[i];
3481
3482			sb_update_failed_devices(sb, failed_devices);
3483		}
3484	}
3485}
3486
3487static int __load_dirty_region_bitmap(struct raid_set *rs)
3488{
3489	int r = 0;
3490
3491	/* Try loading the bitmap unless "raid0", which does not have one */
3492	if (!rs_is_raid0(rs) &&
3493	    !test_and_set_bit(RT_FLAG_RS_BITMAP_LOADED, &rs->runtime_flags)) {
3494		r = bitmap_load(&rs->md);
3495		if (r)
3496			DMERR("Failed to load bitmap");
3497	}
3498
3499	return r;
3500}
3501
3502/* Enforce updating all superblocks */
3503static void rs_update_sbs(struct raid_set *rs)
3504{
3505	struct mddev *mddev = &rs->md;
3506	int ro = mddev->ro;
3507
3508	set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
3509	mddev->ro = 0;
3510	md_update_sb(mddev, 1);
3511	mddev->ro = ro;
3512}
3513
3514/*
3515 * Reshape changes raid algorithm of @rs to new one within personality
3516 * (e.g. raid6_zr -> raid6_nc), changes stripe size, adds/removes
3517 * disks from a raid set thus growing/shrinking it or resizes the set
3518 *
3519 * Call mddev_lock_nointr() before!
3520 */
3521static int rs_start_reshape(struct raid_set *rs)
3522{
3523	int r;
3524	struct mddev *mddev = &rs->md;
3525	struct md_personality *pers = mddev->pers;
3526
3527	r = rs_setup_reshape(rs);
3528	if (r)
3529		return r;
3530
3531	/* Need to be resumed to be able to start reshape, recovery is frozen until raid_resume() though */
3532	if (mddev->suspended)
3533		mddev_resume(mddev);
3534
3535	/*
3536	 * Check any reshape constraints enforced by the personalility
3537	 *
3538	 * May as well already kick the reshape off so that * pers->start_reshape() becomes optional.
3539	 */
3540	r = pers->check_reshape(mddev);
3541	if (r) {
3542		rs->ti->error = "pers->check_reshape() failed";
3543		return r;
3544	}
3545
3546	/*
3547	 * Personality may not provide start reshape method in which
3548	 * case check_reshape above has already covered everything
3549	 */
3550	if (pers->start_reshape) {
3551		r = pers->start_reshape(mddev);
3552		if (r) {
3553			rs->ti->error = "pers->start_reshape() failed";
3554			return r;
3555		}
3556	}
3557
3558	/* Suspend because a resume will happen in raid_resume() */
3559	if (!mddev->suspended)
3560		mddev_suspend(mddev);
3561
3562	/*
3563	 * Now reshape got set up, update superblocks to
3564	 * reflect the fact so that a table reload will
3565	 * access proper superblock content in the ctr.
3566	 */
3567	rs_update_sbs(rs);
3568
3569	return 0;
3570}
3571
3572static int raid_preresume(struct dm_target *ti)
3573{
3574	int r;
3575	struct raid_set *rs = ti->private;
3576	struct mddev *mddev = &rs->md;
3577
3578	/* This is a resume after a suspend of the set -> it's already started */
3579	if (test_and_set_bit(RT_FLAG_RS_PRERESUMED, &rs->runtime_flags))
3580		return 0;
3581
3582	/*
3583	 * The superblocks need to be updated on disk if the
3584	 * array is new or new devices got added (thus zeroed
3585	 * out by userspace) or __load_dirty_region_bitmap
3586	 * will overwrite them in core with old data or fail.
3587	 */
3588	if (test_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags))
3589		rs_update_sbs(rs);
3590
3591	/* Load the bitmap from disk unless raid0 */
3592	r = __load_dirty_region_bitmap(rs);
3593	if (r)
3594		return r;
3595
3596	/* Resize bitmap to adjust to changed region size (aka MD bitmap chunksize) */
3597	if (test_bit(RT_FLAG_RS_BITMAP_LOADED, &rs->runtime_flags) && mddev->bitmap &&
3598	    mddev->bitmap_info.chunksize != to_bytes(rs->requested_bitmap_chunk_sectors)) {
3599		r = bitmap_resize(mddev->bitmap, mddev->dev_sectors,
3600				  to_bytes(rs->requested_bitmap_chunk_sectors), 0);
3601		if (r)
3602			DMERR("Failed to resize bitmap");
3603	}
3604
3605	/* Check for any resize/reshape on @rs and adjust/initiate */
3606	/* Be prepared for mddev_resume() in raid_resume() */
3607	set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3608	if (mddev->recovery_cp && mddev->recovery_cp < MaxSector) {
3609		set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3610		mddev->resync_min = mddev->recovery_cp;
3611	}
3612
3613	rs_set_capacity(rs);
3614
3615	/* Check for any reshape request unless new raid set */
3616	if (test_and_clear_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags)) {
3617		/* Initiate a reshape. */
3618		mddev_lock_nointr(mddev);
3619		r = rs_start_reshape(rs);
3620		mddev_unlock(mddev);
3621		if (r)
3622			DMWARN("Failed to check/start reshape, continuing without change");
3623		r = 0;
3624	}
3625
3626	return r;
3627}
3628
3629#define RESUME_STAY_FROZEN_FLAGS (CTR_FLAG_DELTA_DISKS | CTR_FLAG_DATA_OFFSET)
3630
3631static void raid_resume(struct dm_target *ti)
3632{
3633	struct raid_set *rs = ti->private;
3634	struct mddev *mddev = &rs->md;
3635
3636	if (test_and_set_bit(RT_FLAG_RS_RESUMED, &rs->runtime_flags)) {
3637		/*
3638		 * A secondary resume while the device is active.
3639		 * Take this opportunity to check whether any failed
3640		 * devices are reachable again.
3641		 */
3642		attempt_restore_of_faulty_devices(rs);
3643	}
3644
3645	mddev->ro = 0;
3646	mddev->in_sync = 0;
3647
3648	/*
3649	 * Keep the RAID set frozen if reshape/rebuild flags are set.
3650	 * The RAID set is unfrozen once the next table load/resume,
3651	 * which clears the reshape/rebuild flags, occurs.
3652	 * This ensures that the constructor for the inactive table
3653	 * retrieves an up-to-date reshape_position.
3654	 */
3655	if (!(rs->ctr_flags & RESUME_STAY_FROZEN_FLAGS))
3656		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3657
3658	if (mddev->suspended)
3659		mddev_resume(mddev);
3660}
3661
3662static struct target_type raid_target = {
3663	.name = "raid",
3664	.version = {1, 9, 1},
3665	.module = THIS_MODULE,
3666	.ctr = raid_ctr,
3667	.dtr = raid_dtr,
3668	.map = raid_map,
3669	.status = raid_status,
3670	.message = raid_message,
3671	.iterate_devices = raid_iterate_devices,
3672	.io_hints = raid_io_hints,
3673	.presuspend = raid_presuspend,
3674	.postsuspend = raid_postsuspend,
3675	.preresume = raid_preresume,
3676	.resume = raid_resume,
3677};
3678
3679static int __init dm_raid_init(void)
3680{
3681	DMINFO("Loading target version %u.%u.%u",
3682	       raid_target.version[0],
3683	       raid_target.version[1],
3684	       raid_target.version[2]);
3685	return dm_register_target(&raid_target);
3686}
3687
3688static void __exit dm_raid_exit(void)
3689{
3690	dm_unregister_target(&raid_target);
3691}
3692
3693module_init(dm_raid_init);
3694module_exit(dm_raid_exit);
3695
3696module_param(devices_handle_discard_safely, bool, 0644);
3697MODULE_PARM_DESC(devices_handle_discard_safely,
3698		 "Set to Y if all devices in each array reliably return zeroes on reads from discarded regions");
3699
3700MODULE_DESCRIPTION(DM_NAME " raid0/1/10/4/5/6 target");
3701MODULE_ALIAS("dm-raid0");
3702MODULE_ALIAS("dm-raid1");
3703MODULE_ALIAS("dm-raid10");
3704MODULE_ALIAS("dm-raid4");
3705MODULE_ALIAS("dm-raid5");
3706MODULE_ALIAS("dm-raid6");
3707MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>");
3708MODULE_AUTHOR("Heinz Mauelshagen <dm-devel@redhat.com>");
3709MODULE_LICENSE("GPL");