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v5.9
   1/*
   2 * Copyright (C) 2010-2011 Neil Brown
   3 * Copyright (C) 2010-2018 Red Hat, Inc. All rights reserved.
   4 *
   5 * This file is released under the GPL.
   6 */
   7
   8#include <linux/slab.h>
   9#include <linux/module.h>
  10
  11#include "md.h"
  12#include "raid1.h"
  13#include "raid5.h"
  14#include "raid10.h"
  15#include "md-bitmap.h"
  16
  17#include <linux/device-mapper.h>
  18
  19#define DM_MSG_PREFIX "raid"
  20#define	MAX_RAID_DEVICES	253 /* md-raid kernel limit */
  21
  22/*
  23 * Minimum sectors of free reshape space per raid device
  24 */
  25#define	MIN_FREE_RESHAPE_SPACE to_sector(4*4096)
  26
  27/*
  28 * Minimum journal space 4 MiB in sectors.
  29 */
  30#define	MIN_RAID456_JOURNAL_SPACE (4*2048)
  31
  32static bool devices_handle_discard_safely = false;
  33
  34/*
  35 * The following flags are used by dm-raid.c to set up the array state.
  36 * They must be cleared before md_run is called.
  37 */
  38#define FirstUse 10		/* rdev flag */
  39
  40struct raid_dev {
  41	/*
  42	 * Two DM devices, one to hold metadata and one to hold the
  43	 * actual data/parity.	The reason for this is to not confuse
  44	 * ti->len and give more flexibility in altering size and
  45	 * characteristics.
  46	 *
  47	 * While it is possible for this device to be associated
  48	 * with a different physical device than the data_dev, it
  49	 * is intended for it to be the same.
  50	 *    |--------- Physical Device ---------|
  51	 *    |- meta_dev -|------ data_dev ------|
  52	 */
  53	struct dm_dev *meta_dev;
  54	struct dm_dev *data_dev;
  55	struct md_rdev rdev;
  56};
  57
  58/*
  59 * Bits for establishing rs->ctr_flags
  60 *
  61 * 1 = no flag value
  62 * 2 = flag with value
  63 */
  64#define __CTR_FLAG_SYNC			0  /* 1 */ /* Not with raid0! */
  65#define __CTR_FLAG_NOSYNC		1  /* 1 */ /* Not with raid0! */
  66#define __CTR_FLAG_REBUILD		2  /* 2 */ /* Not with raid0! */
  67#define __CTR_FLAG_DAEMON_SLEEP		3  /* 2 */ /* Not with raid0! */
  68#define __CTR_FLAG_MIN_RECOVERY_RATE	4  /* 2 */ /* Not with raid0! */
  69#define __CTR_FLAG_MAX_RECOVERY_RATE	5  /* 2 */ /* Not with raid0! */
  70#define __CTR_FLAG_MAX_WRITE_BEHIND	6  /* 2 */ /* Only with raid1! */
  71#define __CTR_FLAG_WRITE_MOSTLY		7  /* 2 */ /* Only with raid1! */
  72#define __CTR_FLAG_STRIPE_CACHE		8  /* 2 */ /* Only with raid4/5/6! */
  73#define __CTR_FLAG_REGION_SIZE		9  /* 2 */ /* Not with raid0! */
  74#define __CTR_FLAG_RAID10_COPIES	10 /* 2 */ /* Only with raid10 */
  75#define __CTR_FLAG_RAID10_FORMAT	11 /* 2 */ /* Only with raid10 */
  76/* New for v1.9.0 */
  77#define __CTR_FLAG_DELTA_DISKS		12 /* 2 */ /* Only with reshapable raid1/4/5/6/10! */
  78#define __CTR_FLAG_DATA_OFFSET		13 /* 2 */ /* Only with reshapable raid4/5/6/10! */
  79#define __CTR_FLAG_RAID10_USE_NEAR_SETS 14 /* 2 */ /* Only with raid10! */
  80
  81/* New for v1.10.0 */
  82#define __CTR_FLAG_JOURNAL_DEV		15 /* 2 */ /* Only with raid4/5/6 (journal device)! */
  83
  84/* New for v1.11.1 */
  85#define __CTR_FLAG_JOURNAL_MODE		16 /* 2 */ /* Only with raid4/5/6 (journal mode)! */
  86
  87/*
  88 * Flags for rs->ctr_flags field.
  89 */
  90#define CTR_FLAG_SYNC			(1 << __CTR_FLAG_SYNC)
  91#define CTR_FLAG_NOSYNC			(1 << __CTR_FLAG_NOSYNC)
  92#define CTR_FLAG_REBUILD		(1 << __CTR_FLAG_REBUILD)
  93#define CTR_FLAG_DAEMON_SLEEP		(1 << __CTR_FLAG_DAEMON_SLEEP)
  94#define CTR_FLAG_MIN_RECOVERY_RATE	(1 << __CTR_FLAG_MIN_RECOVERY_RATE)
  95#define CTR_FLAG_MAX_RECOVERY_RATE	(1 << __CTR_FLAG_MAX_RECOVERY_RATE)
  96#define CTR_FLAG_MAX_WRITE_BEHIND	(1 << __CTR_FLAG_MAX_WRITE_BEHIND)
  97#define CTR_FLAG_WRITE_MOSTLY		(1 << __CTR_FLAG_WRITE_MOSTLY)
  98#define CTR_FLAG_STRIPE_CACHE		(1 << __CTR_FLAG_STRIPE_CACHE)
  99#define CTR_FLAG_REGION_SIZE		(1 << __CTR_FLAG_REGION_SIZE)
 100#define CTR_FLAG_RAID10_COPIES		(1 << __CTR_FLAG_RAID10_COPIES)
 101#define CTR_FLAG_RAID10_FORMAT		(1 << __CTR_FLAG_RAID10_FORMAT)
 102#define CTR_FLAG_DELTA_DISKS		(1 << __CTR_FLAG_DELTA_DISKS)
 103#define CTR_FLAG_DATA_OFFSET		(1 << __CTR_FLAG_DATA_OFFSET)
 104#define CTR_FLAG_RAID10_USE_NEAR_SETS	(1 << __CTR_FLAG_RAID10_USE_NEAR_SETS)
 105#define CTR_FLAG_JOURNAL_DEV		(1 << __CTR_FLAG_JOURNAL_DEV)
 106#define CTR_FLAG_JOURNAL_MODE		(1 << __CTR_FLAG_JOURNAL_MODE)
 107
 108/*
 109 * Definitions of various constructor flags to
 110 * be used in checks of valid / invalid flags
 111 * per raid level.
 112 */
 113/* Define all any sync flags */
 114#define	CTR_FLAGS_ANY_SYNC		(CTR_FLAG_SYNC | CTR_FLAG_NOSYNC)
 115
 116/* Define flags for options without argument (e.g. 'nosync') */
 117#define	CTR_FLAG_OPTIONS_NO_ARGS	(CTR_FLAGS_ANY_SYNC | \
 118					 CTR_FLAG_RAID10_USE_NEAR_SETS)
 119
 120/* Define flags for options with one argument (e.g. 'delta_disks +2') */
 121#define CTR_FLAG_OPTIONS_ONE_ARG (CTR_FLAG_REBUILD | \
 122				  CTR_FLAG_WRITE_MOSTLY | \
 123				  CTR_FLAG_DAEMON_SLEEP | \
 124				  CTR_FLAG_MIN_RECOVERY_RATE | \
 125				  CTR_FLAG_MAX_RECOVERY_RATE | \
 126				  CTR_FLAG_MAX_WRITE_BEHIND | \
 127				  CTR_FLAG_STRIPE_CACHE | \
 128				  CTR_FLAG_REGION_SIZE | \
 129				  CTR_FLAG_RAID10_COPIES | \
 130				  CTR_FLAG_RAID10_FORMAT | \
 131				  CTR_FLAG_DELTA_DISKS | \
 132				  CTR_FLAG_DATA_OFFSET | \
 133				  CTR_FLAG_JOURNAL_DEV | \
 134				  CTR_FLAG_JOURNAL_MODE)
 135
 136/* Valid options definitions per raid level... */
 137
 138/* "raid0" does only accept data offset */
 139#define RAID0_VALID_FLAGS	(CTR_FLAG_DATA_OFFSET)
 140
 141/* "raid1" does not accept stripe cache, data offset, delta_disks or any raid10 options */
 142#define RAID1_VALID_FLAGS	(CTR_FLAGS_ANY_SYNC | \
 143				 CTR_FLAG_REBUILD | \
 144				 CTR_FLAG_WRITE_MOSTLY | \
 145				 CTR_FLAG_DAEMON_SLEEP | \
 146				 CTR_FLAG_MIN_RECOVERY_RATE | \
 147				 CTR_FLAG_MAX_RECOVERY_RATE | \
 148				 CTR_FLAG_MAX_WRITE_BEHIND | \
 149				 CTR_FLAG_REGION_SIZE | \
 150				 CTR_FLAG_DELTA_DISKS | \
 151				 CTR_FLAG_DATA_OFFSET)
 152
 153/* "raid10" does not accept any raid1 or stripe cache options */
 154#define RAID10_VALID_FLAGS	(CTR_FLAGS_ANY_SYNC | \
 155				 CTR_FLAG_REBUILD | \
 156				 CTR_FLAG_DAEMON_SLEEP | \
 157				 CTR_FLAG_MIN_RECOVERY_RATE | \
 158				 CTR_FLAG_MAX_RECOVERY_RATE | \
 159				 CTR_FLAG_REGION_SIZE | \
 160				 CTR_FLAG_RAID10_COPIES | \
 161				 CTR_FLAG_RAID10_FORMAT | \
 162				 CTR_FLAG_DELTA_DISKS | \
 163				 CTR_FLAG_DATA_OFFSET | \
 164				 CTR_FLAG_RAID10_USE_NEAR_SETS)
 165
 166/*
 167 * "raid4/5/6" do not accept any raid1 or raid10 specific options
 168 *
 169 * "raid6" does not accept "nosync", because it is not guaranteed
 170 * that both parity and q-syndrome are being written properly with
 171 * any writes
 172 */
 173#define RAID45_VALID_FLAGS	(CTR_FLAGS_ANY_SYNC | \
 174				 CTR_FLAG_REBUILD | \
 175				 CTR_FLAG_DAEMON_SLEEP | \
 176				 CTR_FLAG_MIN_RECOVERY_RATE | \
 177				 CTR_FLAG_MAX_RECOVERY_RATE | \
 178				 CTR_FLAG_STRIPE_CACHE | \
 179				 CTR_FLAG_REGION_SIZE | \
 180				 CTR_FLAG_DELTA_DISKS | \
 181				 CTR_FLAG_DATA_OFFSET | \
 182				 CTR_FLAG_JOURNAL_DEV | \
 183				 CTR_FLAG_JOURNAL_MODE)
 184
 185#define RAID6_VALID_FLAGS	(CTR_FLAG_SYNC | \
 186				 CTR_FLAG_REBUILD | \
 187				 CTR_FLAG_DAEMON_SLEEP | \
 188				 CTR_FLAG_MIN_RECOVERY_RATE | \
 189				 CTR_FLAG_MAX_RECOVERY_RATE | \
 190				 CTR_FLAG_STRIPE_CACHE | \
 191				 CTR_FLAG_REGION_SIZE | \
 192				 CTR_FLAG_DELTA_DISKS | \
 193				 CTR_FLAG_DATA_OFFSET | \
 194				 CTR_FLAG_JOURNAL_DEV | \
 195				 CTR_FLAG_JOURNAL_MODE)
 196/* ...valid options definitions per raid level */
 197
 198/*
 199 * Flags for rs->runtime_flags field
 200 * (RT_FLAG prefix meaning "runtime flag")
 201 *
 202 * These are all internal and used to define runtime state,
 203 * e.g. to prevent another resume from preresume processing
 204 * the raid set all over again.
 205 */
 206#define RT_FLAG_RS_PRERESUMED		0
 207#define RT_FLAG_RS_RESUMED		1
 208#define RT_FLAG_RS_BITMAP_LOADED	2
 209#define RT_FLAG_UPDATE_SBS		3
 210#define RT_FLAG_RESHAPE_RS		4
 211#define RT_FLAG_RS_SUSPENDED		5
 212#define RT_FLAG_RS_IN_SYNC		6
 213#define RT_FLAG_RS_RESYNCING		7
 214#define RT_FLAG_RS_GROW			8
 215
 216/* Array elements of 64 bit needed for rebuild/failed disk bits */
 217#define DISKS_ARRAY_ELEMS ((MAX_RAID_DEVICES + (sizeof(uint64_t) * 8 - 1)) / sizeof(uint64_t) / 8)
 218
 219/*
 220 * raid set level, layout and chunk sectors backup/restore
 221 */
 222struct rs_layout {
 223	int new_level;
 224	int new_layout;
 225	int new_chunk_sectors;
 226};
 227
 228struct raid_set {
 229	struct dm_target *ti;
 230
 231	uint32_t stripe_cache_entries;
 232	unsigned long ctr_flags;
 233	unsigned long runtime_flags;
 234
 235	uint64_t rebuild_disks[DISKS_ARRAY_ELEMS];
 236
 237	int raid_disks;
 238	int delta_disks;
 239	int data_offset;
 240	int raid10_copies;
 241	int requested_bitmap_chunk_sectors;
 242
 243	struct mddev md;
 244	struct raid_type *raid_type;
 245
 246	sector_t array_sectors;
 247	sector_t dev_sectors;
 248
 249	/* Optional raid4/5/6 journal device */
 250	struct journal_dev {
 251		struct dm_dev *dev;
 252		struct md_rdev rdev;
 253		int mode;
 254	} journal_dev;
 255
 256	struct raid_dev dev[];
 257};
 258
 259static void rs_config_backup(struct raid_set *rs, struct rs_layout *l)
 260{
 261	struct mddev *mddev = &rs->md;
 262
 263	l->new_level = mddev->new_level;
 264	l->new_layout = mddev->new_layout;
 265	l->new_chunk_sectors = mddev->new_chunk_sectors;
 266}
 267
 268static void rs_config_restore(struct raid_set *rs, struct rs_layout *l)
 269{
 270	struct mddev *mddev = &rs->md;
 271
 272	mddev->new_level = l->new_level;
 273	mddev->new_layout = l->new_layout;
 274	mddev->new_chunk_sectors = l->new_chunk_sectors;
 275}
 276
 277/* raid10 algorithms (i.e. formats) */
 278#define	ALGORITHM_RAID10_DEFAULT	0
 279#define	ALGORITHM_RAID10_NEAR		1
 280#define	ALGORITHM_RAID10_OFFSET		2
 281#define	ALGORITHM_RAID10_FAR		3
 282
 283/* Supported raid types and properties. */
 284static struct raid_type {
 285	const char *name;		/* RAID algorithm. */
 286	const char *descr;		/* Descriptor text for logging. */
 287	const unsigned int parity_devs;	/* # of parity devices. */
 288	const unsigned int minimal_devs;/* minimal # of devices in set. */
 289	const unsigned int level;	/* RAID level. */
 290	const unsigned int algorithm;	/* RAID algorithm. */
 291} raid_types[] = {
 292	{"raid0",	  "raid0 (striping)",			    0, 2, 0,  0 /* NONE */},
 293	{"raid1",	  "raid1 (mirroring)",			    0, 2, 1,  0 /* NONE */},
 294	{"raid10_far",	  "raid10 far (striped mirrors)",	    0, 2, 10, ALGORITHM_RAID10_FAR},
 295	{"raid10_offset", "raid10 offset (striped mirrors)",	    0, 2, 10, ALGORITHM_RAID10_OFFSET},
 296	{"raid10_near",	  "raid10 near (striped mirrors)",	    0, 2, 10, ALGORITHM_RAID10_NEAR},
 297	{"raid10",	  "raid10 (striped mirrors)",		    0, 2, 10, ALGORITHM_RAID10_DEFAULT},
 298	{"raid4",	  "raid4 (dedicated first parity disk)",    1, 2, 5,  ALGORITHM_PARITY_0}, /* raid4 layout = raid5_0 */
 299	{"raid5_n",	  "raid5 (dedicated last parity disk)",	    1, 2, 5,  ALGORITHM_PARITY_N},
 300	{"raid5_ls",	  "raid5 (left symmetric)",		    1, 2, 5,  ALGORITHM_LEFT_SYMMETRIC},
 301	{"raid5_rs",	  "raid5 (right symmetric)",		    1, 2, 5,  ALGORITHM_RIGHT_SYMMETRIC},
 302	{"raid5_la",	  "raid5 (left asymmetric)",		    1, 2, 5,  ALGORITHM_LEFT_ASYMMETRIC},
 303	{"raid5_ra",	  "raid5 (right asymmetric)",		    1, 2, 5,  ALGORITHM_RIGHT_ASYMMETRIC},
 304	{"raid6_zr",	  "raid6 (zero restart)",		    2, 4, 6,  ALGORITHM_ROTATING_ZERO_RESTART},
 305	{"raid6_nr",	  "raid6 (N restart)",			    2, 4, 6,  ALGORITHM_ROTATING_N_RESTART},
 306	{"raid6_nc",	  "raid6 (N continue)",			    2, 4, 6,  ALGORITHM_ROTATING_N_CONTINUE},
 307	{"raid6_n_6",	  "raid6 (dedicated parity/Q n/6)",	    2, 4, 6,  ALGORITHM_PARITY_N_6},
 308	{"raid6_ls_6",	  "raid6 (left symmetric dedicated Q 6)",   2, 4, 6,  ALGORITHM_LEFT_SYMMETRIC_6},
 309	{"raid6_rs_6",	  "raid6 (right symmetric dedicated Q 6)",  2, 4, 6,  ALGORITHM_RIGHT_SYMMETRIC_6},
 310	{"raid6_la_6",	  "raid6 (left asymmetric dedicated Q 6)",  2, 4, 6,  ALGORITHM_LEFT_ASYMMETRIC_6},
 311	{"raid6_ra_6",	  "raid6 (right asymmetric dedicated Q 6)", 2, 4, 6,  ALGORITHM_RIGHT_ASYMMETRIC_6}
 312};
 313
 314/* True, if @v is in inclusive range [@min, @max] */
 315static bool __within_range(long v, long min, long max)
 316{
 317	return v >= min && v <= max;
 318}
 319
 320/* All table line arguments are defined here */
 321static struct arg_name_flag {
 322	const unsigned long flag;
 323	const char *name;
 324} __arg_name_flags[] = {
 325	{ CTR_FLAG_SYNC, "sync"},
 326	{ CTR_FLAG_NOSYNC, "nosync"},
 327	{ CTR_FLAG_REBUILD, "rebuild"},
 328	{ CTR_FLAG_DAEMON_SLEEP, "daemon_sleep"},
 329	{ CTR_FLAG_MIN_RECOVERY_RATE, "min_recovery_rate"},
 330	{ CTR_FLAG_MAX_RECOVERY_RATE, "max_recovery_rate"},
 331	{ CTR_FLAG_MAX_WRITE_BEHIND, "max_write_behind"},
 332	{ CTR_FLAG_WRITE_MOSTLY, "write_mostly"},
 333	{ CTR_FLAG_STRIPE_CACHE, "stripe_cache"},
 334	{ CTR_FLAG_REGION_SIZE, "region_size"},
 335	{ CTR_FLAG_RAID10_COPIES, "raid10_copies"},
 336	{ CTR_FLAG_RAID10_FORMAT, "raid10_format"},
 337	{ CTR_FLAG_DATA_OFFSET, "data_offset"},
 338	{ CTR_FLAG_DELTA_DISKS, "delta_disks"},
 339	{ CTR_FLAG_RAID10_USE_NEAR_SETS, "raid10_use_near_sets"},
 340	{ CTR_FLAG_JOURNAL_DEV, "journal_dev" },
 341	{ CTR_FLAG_JOURNAL_MODE, "journal_mode" },
 342};
 343
 344/* Return argument name string for given @flag */
 345static const char *dm_raid_arg_name_by_flag(const uint32_t flag)
 346{
 347	if (hweight32(flag) == 1) {
 348		struct arg_name_flag *anf = __arg_name_flags + ARRAY_SIZE(__arg_name_flags);
 349
 350		while (anf-- > __arg_name_flags)
 351			if (flag & anf->flag)
 352				return anf->name;
 353
 354	} else
 355		DMERR("%s called with more than one flag!", __func__);
 356
 357	return NULL;
 358}
 359
 360/* Define correlation of raid456 journal cache modes and dm-raid target line parameters */
 361static struct {
 362	const int mode;
 363	const char *param;
 364} _raid456_journal_mode[] = {
 365	{ R5C_JOURNAL_MODE_WRITE_THROUGH , "writethrough" },
 366	{ R5C_JOURNAL_MODE_WRITE_BACK    , "writeback" }
 367};
 368
 369/* Return MD raid4/5/6 journal mode for dm @journal_mode one */
 370static int dm_raid_journal_mode_to_md(const char *mode)
 371{
 372	int m = ARRAY_SIZE(_raid456_journal_mode);
 373
 374	while (m--)
 375		if (!strcasecmp(mode, _raid456_journal_mode[m].param))
 376			return _raid456_journal_mode[m].mode;
 377
 378	return -EINVAL;
 379}
 380
 381/* Return dm-raid raid4/5/6 journal mode string for @mode */
 382static const char *md_journal_mode_to_dm_raid(const int mode)
 383{
 384	int m = ARRAY_SIZE(_raid456_journal_mode);
 385
 386	while (m--)
 387		if (mode == _raid456_journal_mode[m].mode)
 388			return _raid456_journal_mode[m].param;
 389
 390	return "unknown";
 391}
 392
 393/*
 394 * Bool helpers to test for various raid levels of a raid set.
 395 * It's level as reported by the superblock rather than
 396 * the requested raid_type passed to the constructor.
 397 */
 398/* Return true, if raid set in @rs is raid0 */
 399static bool rs_is_raid0(struct raid_set *rs)
 400{
 401	return !rs->md.level;
 402}
 403
 404/* Return true, if raid set in @rs is raid1 */
 405static bool rs_is_raid1(struct raid_set *rs)
 406{
 407	return rs->md.level == 1;
 408}
 409
 410/* Return true, if raid set in @rs is raid10 */
 411static bool rs_is_raid10(struct raid_set *rs)
 412{
 413	return rs->md.level == 10;
 414}
 415
 416/* Return true, if raid set in @rs is level 6 */
 417static bool rs_is_raid6(struct raid_set *rs)
 418{
 419	return rs->md.level == 6;
 420}
 421
 422/* Return true, if raid set in @rs is level 4, 5 or 6 */
 423static bool rs_is_raid456(struct raid_set *rs)
 424{
 425	return __within_range(rs->md.level, 4, 6);
 426}
 427
 428/* Return true, if raid set in @rs is reshapable */
 429static bool __is_raid10_far(int layout);
 430static bool rs_is_reshapable(struct raid_set *rs)
 431{
 432	return rs_is_raid456(rs) ||
 433	       (rs_is_raid10(rs) && !__is_raid10_far(rs->md.new_layout));
 434}
 435
 436/* Return true, if raid set in @rs is recovering */
 437static bool rs_is_recovering(struct raid_set *rs)
 438{
 439	return rs->md.recovery_cp < rs->md.dev_sectors;
 440}
 441
 442/* Return true, if raid set in @rs is reshaping */
 443static bool rs_is_reshaping(struct raid_set *rs)
 444{
 445	return rs->md.reshape_position != MaxSector;
 446}
 447
 448/*
 449 * bool helpers to test for various raid levels of a raid type @rt
 450 */
 451
 452/* Return true, if raid type in @rt is raid0 */
 453static bool rt_is_raid0(struct raid_type *rt)
 454{
 455	return !rt->level;
 456}
 457
 458/* Return true, if raid type in @rt is raid1 */
 459static bool rt_is_raid1(struct raid_type *rt)
 460{
 461	return rt->level == 1;
 462}
 463
 464/* Return true, if raid type in @rt is raid10 */
 465static bool rt_is_raid10(struct raid_type *rt)
 466{
 467	return rt->level == 10;
 468}
 469
 470/* Return true, if raid type in @rt is raid4/5 */
 471static bool rt_is_raid45(struct raid_type *rt)
 472{
 473	return __within_range(rt->level, 4, 5);
 474}
 475
 476/* Return true, if raid type in @rt is raid6 */
 477static bool rt_is_raid6(struct raid_type *rt)
 478{
 479	return rt->level == 6;
 480}
 481
 482/* Return true, if raid type in @rt is raid4/5/6 */
 483static bool rt_is_raid456(struct raid_type *rt)
 484{
 485	return __within_range(rt->level, 4, 6);
 486}
 487/* END: raid level bools */
 488
 489/* Return valid ctr flags for the raid level of @rs */
 490static unsigned long __valid_flags(struct raid_set *rs)
 491{
 492	if (rt_is_raid0(rs->raid_type))
 493		return RAID0_VALID_FLAGS;
 494	else if (rt_is_raid1(rs->raid_type))
 495		return RAID1_VALID_FLAGS;
 496	else if (rt_is_raid10(rs->raid_type))
 497		return RAID10_VALID_FLAGS;
 498	else if (rt_is_raid45(rs->raid_type))
 499		return RAID45_VALID_FLAGS;
 500	else if (rt_is_raid6(rs->raid_type))
 501		return RAID6_VALID_FLAGS;
 502
 503	return 0;
 504}
 505
 506/*
 507 * Check for valid flags set on @rs
 508 *
 509 * Has to be called after parsing of the ctr flags!
 510 */
 511static int rs_check_for_valid_flags(struct raid_set *rs)
 512{
 513	if (rs->ctr_flags & ~__valid_flags(rs)) {
 514		rs->ti->error = "Invalid flags combination";
 515		return -EINVAL;
 516	}
 517
 518	return 0;
 519}
 520
 521/* MD raid10 bit definitions and helpers */
 522#define RAID10_OFFSET			(1 << 16) /* stripes with data copies area adjacent on devices */
 523#define RAID10_BROCKEN_USE_FAR_SETS	(1 << 17) /* Broken in raid10.c: use sets instead of whole stripe rotation */
 524#define RAID10_USE_FAR_SETS		(1 << 18) /* Use sets instead of whole stripe rotation */
 525#define RAID10_FAR_COPIES_SHIFT		8	  /* raid10 # far copies shift (2nd byte of layout) */
 526
 527/* Return md raid10 near copies for @layout */
 528static unsigned int __raid10_near_copies(int layout)
 529{
 530	return layout & 0xFF;
 531}
 532
 533/* Return md raid10 far copies for @layout */
 534static unsigned int __raid10_far_copies(int layout)
 535{
 536	return __raid10_near_copies(layout >> RAID10_FAR_COPIES_SHIFT);
 537}
 538
 539/* Return true if md raid10 offset for @layout */
 540static bool __is_raid10_offset(int layout)
 541{
 542	return !!(layout & RAID10_OFFSET);
 543}
 544
 545/* Return true if md raid10 near for @layout */
 546static bool __is_raid10_near(int layout)
 547{
 548	return !__is_raid10_offset(layout) && __raid10_near_copies(layout) > 1;
 549}
 550
 551/* Return true if md raid10 far for @layout */
 552static bool __is_raid10_far(int layout)
 553{
 554	return !__is_raid10_offset(layout) && __raid10_far_copies(layout) > 1;
 555}
 556
 557/* Return md raid10 layout string for @layout */
 558static const char *raid10_md_layout_to_format(int layout)
 559{
 560	/*
 561	 * Bit 16 stands for "offset"
 562	 * (i.e. adjacent stripes hold copies)
 563	 *
 564	 * Refer to MD's raid10.c for details
 565	 */
 566	if (__is_raid10_offset(layout))
 567		return "offset";
 568
 569	if (__raid10_near_copies(layout) > 1)
 570		return "near";
 571
 572	if (__raid10_far_copies(layout) > 1)
 573		return "far";
 574
 575	return "unknown";
 576}
 577
 578/* Return md raid10 algorithm for @name */
 579static int raid10_name_to_format(const char *name)
 580{
 581	if (!strcasecmp(name, "near"))
 582		return ALGORITHM_RAID10_NEAR;
 583	else if (!strcasecmp(name, "offset"))
 584		return ALGORITHM_RAID10_OFFSET;
 585	else if (!strcasecmp(name, "far"))
 586		return ALGORITHM_RAID10_FAR;
 587
 588	return -EINVAL;
 589}
 590
 591/* Return md raid10 copies for @layout */
 592static unsigned int raid10_md_layout_to_copies(int layout)
 593{
 594	return max(__raid10_near_copies(layout), __raid10_far_copies(layout));
 595}
 596
 597/* Return md raid10 format id for @format string */
 598static int raid10_format_to_md_layout(struct raid_set *rs,
 599				      unsigned int algorithm,
 600				      unsigned int copies)
 601{
 602	unsigned int n = 1, f = 1, r = 0;
 603
 604	/*
 605	 * MD resilienece flaw:
 606	 *
 607	 * enabling use_far_sets for far/offset formats causes copies
 608	 * to be colocated on the same devs together with their origins!
 609	 *
 610	 * -> disable it for now in the definition above
 611	 */
 612	if (algorithm == ALGORITHM_RAID10_DEFAULT ||
 613	    algorithm == ALGORITHM_RAID10_NEAR)
 614		n = copies;
 615
 616	else if (algorithm == ALGORITHM_RAID10_OFFSET) {
 617		f = copies;
 618		r = RAID10_OFFSET;
 619		if (!test_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags))
 620			r |= RAID10_USE_FAR_SETS;
 621
 622	} else if (algorithm == ALGORITHM_RAID10_FAR) {
 623		f = copies;
 624		if (!test_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags))
 625			r |= RAID10_USE_FAR_SETS;
 626
 627	} else
 628		return -EINVAL;
 629
 630	return r | (f << RAID10_FAR_COPIES_SHIFT) | n;
 631}
 632/* END: MD raid10 bit definitions and helpers */
 633
 634/* Check for any of the raid10 algorithms */
 635static bool __got_raid10(struct raid_type *rtp, const int layout)
 636{
 637	if (rtp->level == 10) {
 638		switch (rtp->algorithm) {
 639		case ALGORITHM_RAID10_DEFAULT:
 640		case ALGORITHM_RAID10_NEAR:
 641			return __is_raid10_near(layout);
 642		case ALGORITHM_RAID10_OFFSET:
 643			return __is_raid10_offset(layout);
 644		case ALGORITHM_RAID10_FAR:
 645			return __is_raid10_far(layout);
 646		default:
 647			break;
 648		}
 649	}
 650
 651	return false;
 652}
 653
 654/* Return raid_type for @name */
 655static struct raid_type *get_raid_type(const char *name)
 656{
 657	struct raid_type *rtp = raid_types + ARRAY_SIZE(raid_types);
 658
 659	while (rtp-- > raid_types)
 660		if (!strcasecmp(rtp->name, name))
 661			return rtp;
 662
 663	return NULL;
 664}
 665
 666/* Return raid_type for @name based derived from @level and @layout */
 667static struct raid_type *get_raid_type_by_ll(const int level, const int layout)
 668{
 669	struct raid_type *rtp = raid_types + ARRAY_SIZE(raid_types);
 670
 671	while (rtp-- > raid_types) {
 672		/* RAID10 special checks based on @layout flags/properties */
 673		if (rtp->level == level &&
 674		    (__got_raid10(rtp, layout) || rtp->algorithm == layout))
 675			return rtp;
 676	}
 677
 678	return NULL;
 679}
 680
 681/* Adjust rdev sectors */
 682static void rs_set_rdev_sectors(struct raid_set *rs)
 683{
 684	struct mddev *mddev = &rs->md;
 685	struct md_rdev *rdev;
 686
 687	/*
 688	 * raid10 sets rdev->sector to the device size, which
 689	 * is unintended in case of out-of-place reshaping
 690	 */
 691	rdev_for_each(rdev, mddev)
 692		if (!test_bit(Journal, &rdev->flags))
 693			rdev->sectors = mddev->dev_sectors;
 694}
 695
 696/*
 697 * Change bdev capacity of @rs in case of a disk add/remove reshape
 698 */
 699static void rs_set_capacity(struct raid_set *rs)
 700{
 701	struct gendisk *gendisk = dm_disk(dm_table_get_md(rs->ti->table));
 702
 703	set_capacity(gendisk, rs->md.array_sectors);
 704	revalidate_disk(gendisk);
 705}
 706
 707/*
 708 * Set the mddev properties in @rs to the current
 709 * ones retrieved from the freshest superblock
 710 */
 711static void rs_set_cur(struct raid_set *rs)
 712{
 713	struct mddev *mddev = &rs->md;
 714
 715	mddev->new_level = mddev->level;
 716	mddev->new_layout = mddev->layout;
 717	mddev->new_chunk_sectors = mddev->chunk_sectors;
 718}
 719
 720/*
 721 * Set the mddev properties in @rs to the new
 722 * ones requested by the ctr
 723 */
 724static void rs_set_new(struct raid_set *rs)
 725{
 726	struct mddev *mddev = &rs->md;
 727
 728	mddev->level = mddev->new_level;
 729	mddev->layout = mddev->new_layout;
 730	mddev->chunk_sectors = mddev->new_chunk_sectors;
 731	mddev->raid_disks = rs->raid_disks;
 732	mddev->delta_disks = 0;
 733}
 734
 735static struct raid_set *raid_set_alloc(struct dm_target *ti, struct raid_type *raid_type,
 736				       unsigned int raid_devs)
 737{
 738	unsigned int i;
 739	struct raid_set *rs;
 740
 741	if (raid_devs <= raid_type->parity_devs) {
 742		ti->error = "Insufficient number of devices";
 743		return ERR_PTR(-EINVAL);
 744	}
 745
 746	rs = kzalloc(struct_size(rs, dev, raid_devs), GFP_KERNEL);
 747	if (!rs) {
 748		ti->error = "Cannot allocate raid context";
 749		return ERR_PTR(-ENOMEM);
 750	}
 751
 752	mddev_init(&rs->md);
 753
 754	rs->raid_disks = raid_devs;
 755	rs->delta_disks = 0;
 756
 757	rs->ti = ti;
 758	rs->raid_type = raid_type;
 759	rs->stripe_cache_entries = 256;
 760	rs->md.raid_disks = raid_devs;
 761	rs->md.level = raid_type->level;
 762	rs->md.new_level = rs->md.level;
 763	rs->md.layout = raid_type->algorithm;
 764	rs->md.new_layout = rs->md.layout;
 765	rs->md.delta_disks = 0;
 766	rs->md.recovery_cp = MaxSector;
 767
 768	for (i = 0; i < raid_devs; i++)
 769		md_rdev_init(&rs->dev[i].rdev);
 770
 771	/*
 772	 * Remaining items to be initialized by further RAID params:
 773	 *  rs->md.persistent
 774	 *  rs->md.external
 775	 *  rs->md.chunk_sectors
 776	 *  rs->md.new_chunk_sectors
 777	 *  rs->md.dev_sectors
 778	 */
 779
 780	return rs;
 781}
 782
 783/* Free all @rs allocations */
 784static void raid_set_free(struct raid_set *rs)
 785{
 786	int i;
 787
 788	if (rs->journal_dev.dev) {
 789		md_rdev_clear(&rs->journal_dev.rdev);
 790		dm_put_device(rs->ti, rs->journal_dev.dev);
 791	}
 792
 793	for (i = 0; i < rs->raid_disks; i++) {
 794		if (rs->dev[i].meta_dev)
 795			dm_put_device(rs->ti, rs->dev[i].meta_dev);
 796		md_rdev_clear(&rs->dev[i].rdev);
 797		if (rs->dev[i].data_dev)
 798			dm_put_device(rs->ti, rs->dev[i].data_dev);
 799	}
 800
 801	kfree(rs);
 802}
 803
 804/*
 805 * For every device we have two words
 806 *  <meta_dev>: meta device name or '-' if missing
 807 *  <data_dev>: data device name or '-' if missing
 808 *
 809 * The following are permitted:
 810 *    - -
 811 *    - <data_dev>
 812 *    <meta_dev> <data_dev>
 813 *
 814 * The following is not allowed:
 815 *    <meta_dev> -
 816 *
 817 * This code parses those words.  If there is a failure,
 818 * the caller must use raid_set_free() to unwind the operations.
 819 */
 820static int parse_dev_params(struct raid_set *rs, struct dm_arg_set *as)
 821{
 822	int i;
 823	int rebuild = 0;
 824	int metadata_available = 0;
 825	int r = 0;
 826	const char *arg;
 827
 828	/* Put off the number of raid devices argument to get to dev pairs */
 829	arg = dm_shift_arg(as);
 830	if (!arg)
 831		return -EINVAL;
 832
 833	for (i = 0; i < rs->raid_disks; i++) {
 834		rs->dev[i].rdev.raid_disk = i;
 835
 836		rs->dev[i].meta_dev = NULL;
 837		rs->dev[i].data_dev = NULL;
 838
 839		/*
 840		 * There are no offsets initially.
 841		 * Out of place reshape will set them accordingly.
 842		 */
 843		rs->dev[i].rdev.data_offset = 0;
 844		rs->dev[i].rdev.new_data_offset = 0;
 845		rs->dev[i].rdev.mddev = &rs->md;
 846
 847		arg = dm_shift_arg(as);
 848		if (!arg)
 849			return -EINVAL;
 850
 851		if (strcmp(arg, "-")) {
 852			r = dm_get_device(rs->ti, arg, dm_table_get_mode(rs->ti->table),
 853					  &rs->dev[i].meta_dev);
 854			if (r) {
 855				rs->ti->error = "RAID metadata device lookup failure";
 856				return r;
 857			}
 858
 859			rs->dev[i].rdev.sb_page = alloc_page(GFP_KERNEL);
 860			if (!rs->dev[i].rdev.sb_page) {
 861				rs->ti->error = "Failed to allocate superblock page";
 862				return -ENOMEM;
 863			}
 864		}
 865
 866		arg = dm_shift_arg(as);
 867		if (!arg)
 868			return -EINVAL;
 869
 870		if (!strcmp(arg, "-")) {
 871			if (!test_bit(In_sync, &rs->dev[i].rdev.flags) &&
 872			    (!rs->dev[i].rdev.recovery_offset)) {
 873				rs->ti->error = "Drive designated for rebuild not specified";
 874				return -EINVAL;
 875			}
 876
 877			if (rs->dev[i].meta_dev) {
 878				rs->ti->error = "No data device supplied with metadata device";
 879				return -EINVAL;
 880			}
 881
 882			continue;
 883		}
 884
 885		r = dm_get_device(rs->ti, arg, dm_table_get_mode(rs->ti->table),
 886				  &rs->dev[i].data_dev);
 887		if (r) {
 888			rs->ti->error = "RAID device lookup failure";
 889			return r;
 890		}
 891
 892		if (rs->dev[i].meta_dev) {
 893			metadata_available = 1;
 894			rs->dev[i].rdev.meta_bdev = rs->dev[i].meta_dev->bdev;
 895		}
 896		rs->dev[i].rdev.bdev = rs->dev[i].data_dev->bdev;
 897		list_add_tail(&rs->dev[i].rdev.same_set, &rs->md.disks);
 898		if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
 899			rebuild++;
 900	}
 901
 902	if (rs->journal_dev.dev)
 903		list_add_tail(&rs->journal_dev.rdev.same_set, &rs->md.disks);
 904
 905	if (metadata_available) {
 906		rs->md.external = 0;
 907		rs->md.persistent = 1;
 908		rs->md.major_version = 2;
 909	} else if (rebuild && !rs->md.recovery_cp) {
 910		/*
 911		 * Without metadata, we will not be able to tell if the array
 912		 * is in-sync or not - we must assume it is not.  Therefore,
 913		 * it is impossible to rebuild a drive.
 914		 *
 915		 * Even if there is metadata, the on-disk information may
 916		 * indicate that the array is not in-sync and it will then
 917		 * fail at that time.
 918		 *
 919		 * User could specify 'nosync' option if desperate.
 920		 */
 921		rs->ti->error = "Unable to rebuild drive while array is not in-sync";
 922		return -EINVAL;
 923	}
 924
 925	return 0;
 926}
 927
 928/*
 929 * validate_region_size
 930 * @rs
 931 * @region_size:  region size in sectors.  If 0, pick a size (4MiB default).
 932 *
 933 * Set rs->md.bitmap_info.chunksize (which really refers to 'region size').
 934 * Ensure that (ti->len/region_size < 2^21) - required by MD bitmap.
 935 *
 936 * Returns: 0 on success, -EINVAL on failure.
 937 */
 938static int validate_region_size(struct raid_set *rs, unsigned long region_size)
 939{
 940	unsigned long min_region_size = rs->ti->len / (1 << 21);
 941
 942	if (rs_is_raid0(rs))
 943		return 0;
 944
 945	if (!region_size) {
 946		/*
 947		 * Choose a reasonable default.	 All figures in sectors.
 948		 */
 949		if (min_region_size > (1 << 13)) {
 950			/* If not a power of 2, make it the next power of 2 */
 951			region_size = roundup_pow_of_two(min_region_size);
 952			DMINFO("Choosing default region size of %lu sectors",
 953			       region_size);
 954		} else {
 955			DMINFO("Choosing default region size of 4MiB");
 956			region_size = 1 << 13; /* sectors */
 957		}
 958	} else {
 959		/*
 960		 * Validate user-supplied value.
 961		 */
 962		if (region_size > rs->ti->len) {
 963			rs->ti->error = "Supplied region size is too large";
 964			return -EINVAL;
 965		}
 966
 967		if (region_size < min_region_size) {
 968			DMERR("Supplied region_size (%lu sectors) below minimum (%lu)",
 969			      region_size, min_region_size);
 970			rs->ti->error = "Supplied region size is too small";
 971			return -EINVAL;
 972		}
 973
 974		if (!is_power_of_2(region_size)) {
 975			rs->ti->error = "Region size is not a power of 2";
 976			return -EINVAL;
 977		}
 978
 979		if (region_size < rs->md.chunk_sectors) {
 980			rs->ti->error = "Region size is smaller than the chunk size";
 981			return -EINVAL;
 982		}
 983	}
 984
 985	/*
 986	 * Convert sectors to bytes.
 987	 */
 988	rs->md.bitmap_info.chunksize = to_bytes(region_size);
 989
 990	return 0;
 991}
 992
 993/*
 994 * validate_raid_redundancy
 995 * @rs
 996 *
 997 * Determine if there are enough devices in the array that haven't
 998 * failed (or are being rebuilt) to form a usable array.
 999 *
1000 * Returns: 0 on success, -EINVAL on failure.
1001 */
1002static int validate_raid_redundancy(struct raid_set *rs)
1003{
1004	unsigned int i, rebuild_cnt = 0;
1005	unsigned int rebuilds_per_group = 0, copies;
1006	unsigned int group_size, last_group_start;
1007
1008	for (i = 0; i < rs->md.raid_disks; i++)
1009		if (!test_bit(In_sync, &rs->dev[i].rdev.flags) ||
1010		    !rs->dev[i].rdev.sb_page)
1011			rebuild_cnt++;
1012
1013	switch (rs->md.level) {
1014	case 0:
1015		break;
1016	case 1:
1017		if (rebuild_cnt >= rs->md.raid_disks)
1018			goto too_many;
1019		break;
1020	case 4:
1021	case 5:
1022	case 6:
1023		if (rebuild_cnt > rs->raid_type->parity_devs)
1024			goto too_many;
1025		break;
1026	case 10:
1027		copies = raid10_md_layout_to_copies(rs->md.new_layout);
1028		if (copies < 2) {
1029			DMERR("Bogus raid10 data copies < 2!");
1030			return -EINVAL;
1031		}
1032
1033		if (rebuild_cnt < copies)
1034			break;
1035
1036		/*
1037		 * It is possible to have a higher rebuild count for RAID10,
1038		 * as long as the failed devices occur in different mirror
1039		 * groups (i.e. different stripes).
1040		 *
1041		 * When checking "near" format, make sure no adjacent devices
1042		 * have failed beyond what can be handled.  In addition to the
1043		 * simple case where the number of devices is a multiple of the
1044		 * number of copies, we must also handle cases where the number
1045		 * of devices is not a multiple of the number of copies.
1046		 * E.g.	   dev1 dev2 dev3 dev4 dev5
1047		 *	    A	 A    B	   B	C
1048		 *	    C	 D    D	   E	E
1049		 */
1050		if (__is_raid10_near(rs->md.new_layout)) {
1051			for (i = 0; i < rs->md.raid_disks; i++) {
1052				if (!(i % copies))
1053					rebuilds_per_group = 0;
1054				if ((!rs->dev[i].rdev.sb_page ||
1055				    !test_bit(In_sync, &rs->dev[i].rdev.flags)) &&
1056				    (++rebuilds_per_group >= copies))
1057					goto too_many;
1058			}
1059			break;
1060		}
1061
1062		/*
1063		 * When checking "far" and "offset" formats, we need to ensure
1064		 * that the device that holds its copy is not also dead or
1065		 * being rebuilt.  (Note that "far" and "offset" formats only
1066		 * support two copies right now.  These formats also only ever
1067		 * use the 'use_far_sets' variant.)
1068		 *
1069		 * This check is somewhat complicated by the need to account
1070		 * for arrays that are not a multiple of (far) copies.	This
1071		 * results in the need to treat the last (potentially larger)
1072		 * set differently.
1073		 */
1074		group_size = (rs->md.raid_disks / copies);
1075		last_group_start = (rs->md.raid_disks / group_size) - 1;
1076		last_group_start *= group_size;
1077		for (i = 0; i < rs->md.raid_disks; i++) {
1078			if (!(i % copies) && !(i > last_group_start))
1079				rebuilds_per_group = 0;
1080			if ((!rs->dev[i].rdev.sb_page ||
1081			     !test_bit(In_sync, &rs->dev[i].rdev.flags)) &&
1082			    (++rebuilds_per_group >= copies))
1083					goto too_many;
1084		}
1085		break;
1086	default:
1087		if (rebuild_cnt)
1088			return -EINVAL;
1089	}
1090
1091	return 0;
1092
1093too_many:
1094	return -EINVAL;
1095}
1096
1097/*
1098 * Possible arguments are...
1099 *	<chunk_size> [optional_args]
1100 *
1101 * Argument definitions
1102 *    <chunk_size>			The number of sectors per disk that
1103 *					will form the "stripe"
1104 *    [[no]sync]			Force or prevent recovery of the
1105 *					entire array
1106 *    [rebuild <idx>]			Rebuild the drive indicated by the index
1107 *    [daemon_sleep <ms>]		Time between bitmap daemon work to
1108 *					clear bits
1109 *    [min_recovery_rate <kB/sec/disk>]	Throttle RAID initialization
1110 *    [max_recovery_rate <kB/sec/disk>]	Throttle RAID initialization
1111 *    [write_mostly <idx>]		Indicate a write mostly drive via index
1112 *    [max_write_behind <sectors>]	See '-write-behind=' (man mdadm)
1113 *    [stripe_cache <sectors>]		Stripe cache size for higher RAIDs
1114 *    [region_size <sectors>]		Defines granularity of bitmap
1115 *    [journal_dev <dev>]		raid4/5/6 journaling deviice
1116 *    					(i.e. write hole closing log)
1117 *
1118 * RAID10-only options:
1119 *    [raid10_copies <# copies>]	Number of copies.  (Default: 2)
1120 *    [raid10_format <near|far|offset>] Layout algorithm.  (Default: near)
1121 */
1122static int parse_raid_params(struct raid_set *rs, struct dm_arg_set *as,
1123			     unsigned int num_raid_params)
1124{
1125	int value, raid10_format = ALGORITHM_RAID10_DEFAULT;
1126	unsigned int raid10_copies = 2;
1127	unsigned int i, write_mostly = 0;
1128	unsigned int region_size = 0;
1129	sector_t max_io_len;
1130	const char *arg, *key;
1131	struct raid_dev *rd;
1132	struct raid_type *rt = rs->raid_type;
1133
1134	arg = dm_shift_arg(as);
1135	num_raid_params--; /* Account for chunk_size argument */
1136
1137	if (kstrtoint(arg, 10, &value) < 0) {
1138		rs->ti->error = "Bad numerical argument given for chunk_size";
1139		return -EINVAL;
1140	}
1141
1142	/*
1143	 * First, parse the in-order required arguments
1144	 * "chunk_size" is the only argument of this type.
1145	 */
1146	if (rt_is_raid1(rt)) {
1147		if (value)
1148			DMERR("Ignoring chunk size parameter for RAID 1");
1149		value = 0;
1150	} else if (!is_power_of_2(value)) {
1151		rs->ti->error = "Chunk size must be a power of 2";
1152		return -EINVAL;
1153	} else if (value < 8) {
1154		rs->ti->error = "Chunk size value is too small";
1155		return -EINVAL;
1156	}
1157
1158	rs->md.new_chunk_sectors = rs->md.chunk_sectors = value;
1159
1160	/*
1161	 * We set each individual device as In_sync with a completed
1162	 * 'recovery_offset'.  If there has been a device failure or
1163	 * replacement then one of the following cases applies:
1164	 *
1165	 *   1) User specifies 'rebuild'.
1166	 *	- Device is reset when param is read.
1167	 *   2) A new device is supplied.
1168	 *	- No matching superblock found, resets device.
1169	 *   3) Device failure was transient and returns on reload.
1170	 *	- Failure noticed, resets device for bitmap replay.
1171	 *   4) Device hadn't completed recovery after previous failure.
1172	 *	- Superblock is read and overrides recovery_offset.
1173	 *
1174	 * What is found in the superblocks of the devices is always
1175	 * authoritative, unless 'rebuild' or '[no]sync' was specified.
1176	 */
1177	for (i = 0; i < rs->raid_disks; i++) {
1178		set_bit(In_sync, &rs->dev[i].rdev.flags);
1179		rs->dev[i].rdev.recovery_offset = MaxSector;
1180	}
1181
1182	/*
1183	 * Second, parse the unordered optional arguments
1184	 */
1185	for (i = 0; i < num_raid_params; i++) {
1186		key = dm_shift_arg(as);
1187		if (!key) {
1188			rs->ti->error = "Not enough raid parameters given";
1189			return -EINVAL;
1190		}
1191
1192		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_NOSYNC))) {
1193			if (test_and_set_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
1194				rs->ti->error = "Only one 'nosync' argument allowed";
1195				return -EINVAL;
1196			}
1197			continue;
1198		}
1199		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_SYNC))) {
1200			if (test_and_set_bit(__CTR_FLAG_SYNC, &rs->ctr_flags)) {
1201				rs->ti->error = "Only one 'sync' argument allowed";
1202				return -EINVAL;
1203			}
1204			continue;
1205		}
1206		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_USE_NEAR_SETS))) {
1207			if (test_and_set_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags)) {
1208				rs->ti->error = "Only one 'raid10_use_new_sets' argument allowed";
1209				return -EINVAL;
1210			}
1211			continue;
1212		}
1213
1214		arg = dm_shift_arg(as);
1215		i++; /* Account for the argument pairs */
1216		if (!arg) {
1217			rs->ti->error = "Wrong number of raid parameters given";
1218			return -EINVAL;
1219		}
1220
1221		/*
1222		 * Parameters that take a string value are checked here.
1223		 */
1224		/* "raid10_format {near|offset|far} */
1225		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_FORMAT))) {
1226			if (test_and_set_bit(__CTR_FLAG_RAID10_FORMAT, &rs->ctr_flags)) {
1227				rs->ti->error = "Only one 'raid10_format' argument pair allowed";
1228				return -EINVAL;
1229			}
1230			if (!rt_is_raid10(rt)) {
1231				rs->ti->error = "'raid10_format' is an invalid parameter for this RAID type";
1232				return -EINVAL;
1233			}
1234			raid10_format = raid10_name_to_format(arg);
1235			if (raid10_format < 0) {
1236				rs->ti->error = "Invalid 'raid10_format' value given";
1237				return raid10_format;
1238			}
1239			continue;
1240		}
1241
1242		/* "journal_dev <dev>" */
1243		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_DEV))) {
1244			int r;
1245			struct md_rdev *jdev;
1246
1247			if (test_and_set_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
1248				rs->ti->error = "Only one raid4/5/6 set journaling device allowed";
1249				return -EINVAL;
1250			}
1251			if (!rt_is_raid456(rt)) {
1252				rs->ti->error = "'journal_dev' is an invalid parameter for this RAID type";
1253				return -EINVAL;
1254			}
1255			r = dm_get_device(rs->ti, arg, dm_table_get_mode(rs->ti->table),
1256					  &rs->journal_dev.dev);
1257			if (r) {
1258				rs->ti->error = "raid4/5/6 journal device lookup failure";
1259				return r;
1260			}
1261			jdev = &rs->journal_dev.rdev;
1262			md_rdev_init(jdev);
1263			jdev->mddev = &rs->md;
1264			jdev->bdev = rs->journal_dev.dev->bdev;
1265			jdev->sectors = to_sector(i_size_read(jdev->bdev->bd_inode));
1266			if (jdev->sectors < MIN_RAID456_JOURNAL_SPACE) {
1267				rs->ti->error = "No space for raid4/5/6 journal";
1268				return -ENOSPC;
1269			}
1270			rs->journal_dev.mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
1271			set_bit(Journal, &jdev->flags);
1272			continue;
1273		}
1274
1275		/* "journal_mode <mode>" ("journal_dev" mandatory!) */
1276		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_MODE))) {
1277			int r;
1278
1279			if (!test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
1280				rs->ti->error = "raid4/5/6 'journal_mode' is invalid without 'journal_dev'";
1281				return -EINVAL;
1282			}
1283			if (test_and_set_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags)) {
1284				rs->ti->error = "Only one raid4/5/6 'journal_mode' argument allowed";
1285				return -EINVAL;
1286			}
1287			r = dm_raid_journal_mode_to_md(arg);
1288			if (r < 0) {
1289				rs->ti->error = "Invalid 'journal_mode' argument";
1290				return r;
1291			}
1292			rs->journal_dev.mode = r;
1293			continue;
1294		}
1295
1296		/*
1297		 * Parameters with number values from here on.
1298		 */
1299		if (kstrtoint(arg, 10, &value) < 0) {
1300			rs->ti->error = "Bad numerical argument given in raid params";
1301			return -EINVAL;
1302		}
1303
1304		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_REBUILD))) {
1305			/*
1306			 * "rebuild" is being passed in by userspace to provide
1307			 * indexes of replaced devices and to set up additional
1308			 * devices on raid level takeover.
1309			 */
1310			if (!__within_range(value, 0, rs->raid_disks - 1)) {
1311				rs->ti->error = "Invalid rebuild index given";
1312				return -EINVAL;
1313			}
1314
1315			if (test_and_set_bit(value, (void *) rs->rebuild_disks)) {
1316				rs->ti->error = "rebuild for this index already given";
1317				return -EINVAL;
1318			}
1319
1320			rd = rs->dev + value;
1321			clear_bit(In_sync, &rd->rdev.flags);
1322			clear_bit(Faulty, &rd->rdev.flags);
1323			rd->rdev.recovery_offset = 0;
1324			set_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags);
1325		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_WRITE_MOSTLY))) {
1326			if (!rt_is_raid1(rt)) {
1327				rs->ti->error = "write_mostly option is only valid for RAID1";
1328				return -EINVAL;
1329			}
1330
1331			if (!__within_range(value, 0, rs->md.raid_disks - 1)) {
1332				rs->ti->error = "Invalid write_mostly index given";
1333				return -EINVAL;
1334			}
1335
1336			write_mostly++;
1337			set_bit(WriteMostly, &rs->dev[value].rdev.flags);
1338			set_bit(__CTR_FLAG_WRITE_MOSTLY, &rs->ctr_flags);
1339		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_MAX_WRITE_BEHIND))) {
1340			if (!rt_is_raid1(rt)) {
1341				rs->ti->error = "max_write_behind option is only valid for RAID1";
1342				return -EINVAL;
1343			}
1344
1345			if (test_and_set_bit(__CTR_FLAG_MAX_WRITE_BEHIND, &rs->ctr_flags)) {
1346				rs->ti->error = "Only one max_write_behind argument pair allowed";
1347				return -EINVAL;
1348			}
1349
1350			/*
1351			 * In device-mapper, we specify things in sectors, but
1352			 * MD records this value in kB
1353			 */
1354			if (value < 0 || value / 2 > COUNTER_MAX) {
1355				rs->ti->error = "Max write-behind limit out of range";
1356				return -EINVAL;
1357			}
1358
1359			rs->md.bitmap_info.max_write_behind = value / 2;
1360		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_DAEMON_SLEEP))) {
1361			if (test_and_set_bit(__CTR_FLAG_DAEMON_SLEEP, &rs->ctr_flags)) {
1362				rs->ti->error = "Only one daemon_sleep argument pair allowed";
1363				return -EINVAL;
1364			}
1365			if (value < 0) {
1366				rs->ti->error = "daemon sleep period out of range";
1367				return -EINVAL;
1368			}
1369			rs->md.bitmap_info.daemon_sleep = value;
1370		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_DATA_OFFSET))) {
1371			/* Userspace passes new data_offset after having extended the the data image LV */
1372			if (test_and_set_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags)) {
1373				rs->ti->error = "Only one data_offset argument pair allowed";
1374				return -EINVAL;
1375			}
1376			/* Ensure sensible data offset */
1377			if (value < 0 ||
1378			    (value && (value < MIN_FREE_RESHAPE_SPACE || value % to_sector(PAGE_SIZE)))) {
1379				rs->ti->error = "Bogus data_offset value";
1380				return -EINVAL;
1381			}
1382			rs->data_offset = value;
1383		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_DELTA_DISKS))) {
1384			/* Define the +/-# of disks to add to/remove from the given raid set */
1385			if (test_and_set_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags)) {
1386				rs->ti->error = "Only one delta_disks argument pair allowed";
1387				return -EINVAL;
1388			}
1389			/* Ensure MAX_RAID_DEVICES and raid type minimal_devs! */
1390			if (!__within_range(abs(value), 1, MAX_RAID_DEVICES - rt->minimal_devs)) {
1391				rs->ti->error = "Too many delta_disk requested";
1392				return -EINVAL;
1393			}
1394
1395			rs->delta_disks = value;
1396		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_STRIPE_CACHE))) {
1397			if (test_and_set_bit(__CTR_FLAG_STRIPE_CACHE, &rs->ctr_flags)) {
1398				rs->ti->error = "Only one stripe_cache argument pair allowed";
1399				return -EINVAL;
1400			}
1401
1402			if (!rt_is_raid456(rt)) {
1403				rs->ti->error = "Inappropriate argument: stripe_cache";
1404				return -EINVAL;
1405			}
1406
1407			if (value < 0) {
1408				rs->ti->error = "Bogus stripe cache entries value";
1409				return -EINVAL;
1410			}
1411			rs->stripe_cache_entries = value;
1412		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_MIN_RECOVERY_RATE))) {
1413			if (test_and_set_bit(__CTR_FLAG_MIN_RECOVERY_RATE, &rs->ctr_flags)) {
1414				rs->ti->error = "Only one min_recovery_rate argument pair allowed";
1415				return -EINVAL;
1416			}
1417
1418			if (value < 0) {
1419				rs->ti->error = "min_recovery_rate out of range";
1420				return -EINVAL;
1421			}
1422			rs->md.sync_speed_min = value;
1423		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_MAX_RECOVERY_RATE))) {
1424			if (test_and_set_bit(__CTR_FLAG_MAX_RECOVERY_RATE, &rs->ctr_flags)) {
1425				rs->ti->error = "Only one max_recovery_rate argument pair allowed";
1426				return -EINVAL;
1427			}
1428
1429			if (value < 0) {
1430				rs->ti->error = "max_recovery_rate out of range";
1431				return -EINVAL;
1432			}
1433			rs->md.sync_speed_max = value;
1434		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_REGION_SIZE))) {
1435			if (test_and_set_bit(__CTR_FLAG_REGION_SIZE, &rs->ctr_flags)) {
1436				rs->ti->error = "Only one region_size argument pair allowed";
1437				return -EINVAL;
1438			}
1439
1440			region_size = value;
1441			rs->requested_bitmap_chunk_sectors = value;
1442		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_COPIES))) {
1443			if (test_and_set_bit(__CTR_FLAG_RAID10_COPIES, &rs->ctr_flags)) {
1444				rs->ti->error = "Only one raid10_copies argument pair allowed";
1445				return -EINVAL;
1446			}
1447
1448			if (!__within_range(value, 2, rs->md.raid_disks)) {
1449				rs->ti->error = "Bad value for 'raid10_copies'";
1450				return -EINVAL;
1451			}
1452
1453			raid10_copies = value;
1454		} else {
1455			DMERR("Unable to parse RAID parameter: %s", key);
1456			rs->ti->error = "Unable to parse RAID parameter";
1457			return -EINVAL;
1458		}
1459	}
1460
1461	if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags) &&
1462	    test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
1463		rs->ti->error = "sync and nosync are mutually exclusive";
1464		return -EINVAL;
1465	}
1466
1467	if (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags) &&
1468	    (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags) ||
1469	     test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))) {
1470		rs->ti->error = "sync/nosync and rebuild are mutually exclusive";
1471		return -EINVAL;
1472	}
1473
1474	if (write_mostly >= rs->md.raid_disks) {
1475		rs->ti->error = "Can't set all raid1 devices to write_mostly";
1476		return -EINVAL;
1477	}
1478
1479	if (rs->md.sync_speed_max &&
1480	    rs->md.sync_speed_min > rs->md.sync_speed_max) {
1481		rs->ti->error = "Bogus recovery rates";
1482		return -EINVAL;
1483	}
1484
1485	if (validate_region_size(rs, region_size))
1486		return -EINVAL;
1487
1488	if (rs->md.chunk_sectors)
1489		max_io_len = rs->md.chunk_sectors;
1490	else
1491		max_io_len = region_size;
1492
1493	if (dm_set_target_max_io_len(rs->ti, max_io_len))
1494		return -EINVAL;
1495
1496	if (rt_is_raid10(rt)) {
1497		if (raid10_copies > rs->md.raid_disks) {
1498			rs->ti->error = "Not enough devices to satisfy specification";
1499			return -EINVAL;
1500		}
1501
1502		rs->md.new_layout = raid10_format_to_md_layout(rs, raid10_format, raid10_copies);
1503		if (rs->md.new_layout < 0) {
1504			rs->ti->error = "Error getting raid10 format";
1505			return rs->md.new_layout;
1506		}
1507
1508		rt = get_raid_type_by_ll(10, rs->md.new_layout);
1509		if (!rt) {
1510			rs->ti->error = "Failed to recognize new raid10 layout";
1511			return -EINVAL;
1512		}
1513
1514		if ((rt->algorithm == ALGORITHM_RAID10_DEFAULT ||
1515		     rt->algorithm == ALGORITHM_RAID10_NEAR) &&
1516		    test_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags)) {
1517			rs->ti->error = "RAID10 format 'near' and 'raid10_use_near_sets' are incompatible";
1518			return -EINVAL;
1519		}
1520	}
1521
1522	rs->raid10_copies = raid10_copies;
1523
1524	/* Assume there are no metadata devices until the drives are parsed */
1525	rs->md.persistent = 0;
1526	rs->md.external = 1;
1527
1528	/* Check, if any invalid ctr arguments have been passed in for the raid level */
1529	return rs_check_for_valid_flags(rs);
1530}
1531
1532/* Set raid4/5/6 cache size */
1533static int rs_set_raid456_stripe_cache(struct raid_set *rs)
1534{
1535	int r;
1536	struct r5conf *conf;
1537	struct mddev *mddev = &rs->md;
1538	uint32_t min_stripes = max(mddev->chunk_sectors, mddev->new_chunk_sectors) / 2;
1539	uint32_t nr_stripes = rs->stripe_cache_entries;
1540
1541	if (!rt_is_raid456(rs->raid_type)) {
1542		rs->ti->error = "Inappropriate raid level; cannot change stripe_cache size";
1543		return -EINVAL;
1544	}
1545
1546	if (nr_stripes < min_stripes) {
1547		DMINFO("Adjusting requested %u stripe cache entries to %u to suit stripe size",
1548		       nr_stripes, min_stripes);
1549		nr_stripes = min_stripes;
1550	}
1551
1552	conf = mddev->private;
1553	if (!conf) {
1554		rs->ti->error = "Cannot change stripe_cache size on inactive RAID set";
1555		return -EINVAL;
1556	}
1557
1558	/* Try setting number of stripes in raid456 stripe cache */
1559	if (conf->min_nr_stripes != nr_stripes) {
1560		r = raid5_set_cache_size(mddev, nr_stripes);
1561		if (r) {
1562			rs->ti->error = "Failed to set raid4/5/6 stripe cache size";
1563			return r;
1564		}
1565
1566		DMINFO("%u stripe cache entries", nr_stripes);
1567	}
1568
1569	return 0;
1570}
1571
1572/* Return # of data stripes as kept in mddev as of @rs (i.e. as of superblock) */
1573static unsigned int mddev_data_stripes(struct raid_set *rs)
1574{
1575	return rs->md.raid_disks - rs->raid_type->parity_devs;
1576}
1577
1578/* Return # of data stripes of @rs (i.e. as of ctr) */
1579static unsigned int rs_data_stripes(struct raid_set *rs)
1580{
1581	return rs->raid_disks - rs->raid_type->parity_devs;
1582}
1583
1584/*
1585 * Retrieve rdev->sectors from any valid raid device of @rs
1586 * to allow userpace to pass in arbitray "- -" device tupples.
1587 */
1588static sector_t __rdev_sectors(struct raid_set *rs)
1589{
1590	int i;
1591
1592	for (i = 0; i < rs->md.raid_disks; i++) {
1593		struct md_rdev *rdev = &rs->dev[i].rdev;
1594
1595		if (!test_bit(Journal, &rdev->flags) &&
1596		    rdev->bdev && rdev->sectors)
1597			return rdev->sectors;
1598	}
1599
1600	return 0;
1601}
1602
1603/* Check that calculated dev_sectors fits all component devices. */
1604static int _check_data_dev_sectors(struct raid_set *rs)
1605{
1606	sector_t ds = ~0;
1607	struct md_rdev *rdev;
1608
1609	rdev_for_each(rdev, &rs->md)
1610		if (!test_bit(Journal, &rdev->flags) && rdev->bdev) {
1611			ds = min(ds, to_sector(i_size_read(rdev->bdev->bd_inode)));
1612			if (ds < rs->md.dev_sectors) {
1613				rs->ti->error = "Component device(s) too small";
1614				return -EINVAL;
1615			}
1616		}
1617
1618	return 0;
1619}
1620
1621/* Calculate the sectors per device and per array used for @rs */
1622static int rs_set_dev_and_array_sectors(struct raid_set *rs, sector_t sectors, bool use_mddev)
1623{
1624	int delta_disks;
1625	unsigned int data_stripes;
1626	sector_t array_sectors = sectors, dev_sectors = sectors;
1627	struct mddev *mddev = &rs->md;
1628
1629	if (use_mddev) {
1630		delta_disks = mddev->delta_disks;
1631		data_stripes = mddev_data_stripes(rs);
1632	} else {
1633		delta_disks = rs->delta_disks;
1634		data_stripes = rs_data_stripes(rs);
1635	}
1636
1637	/* Special raid1 case w/o delta_disks support (yet) */
1638	if (rt_is_raid1(rs->raid_type))
1639		;
1640	else if (rt_is_raid10(rs->raid_type)) {
1641		if (rs->raid10_copies < 2 ||
1642		    delta_disks < 0) {
1643			rs->ti->error = "Bogus raid10 data copies or delta disks";
1644			return -EINVAL;
1645		}
1646
1647		dev_sectors *= rs->raid10_copies;
1648		if (sector_div(dev_sectors, data_stripes))
1649			goto bad;
1650
1651		array_sectors = (data_stripes + delta_disks) * dev_sectors;
1652		if (sector_div(array_sectors, rs->raid10_copies))
1653			goto bad;
1654
1655	} else if (sector_div(dev_sectors, data_stripes))
1656		goto bad;
1657
1658	else
1659		/* Striped layouts */
1660		array_sectors = (data_stripes + delta_disks) * dev_sectors;
1661
1662	mddev->array_sectors = array_sectors;
1663	mddev->dev_sectors = dev_sectors;
1664	rs_set_rdev_sectors(rs);
1665
1666	return _check_data_dev_sectors(rs);
1667bad:
1668	rs->ti->error = "Target length not divisible by number of data devices";
1669	return -EINVAL;
1670}
1671
1672/* Setup recovery on @rs */
1673static void rs_setup_recovery(struct raid_set *rs, sector_t dev_sectors)
1674{
1675	/* raid0 does not recover */
1676	if (rs_is_raid0(rs))
1677		rs->md.recovery_cp = MaxSector;
1678	/*
1679	 * A raid6 set has to be recovered either
1680	 * completely or for the grown part to
1681	 * ensure proper parity and Q-Syndrome
1682	 */
1683	else if (rs_is_raid6(rs))
1684		rs->md.recovery_cp = dev_sectors;
1685	/*
1686	 * Other raid set types may skip recovery
1687	 * depending on the 'nosync' flag.
1688	 */
1689	else
1690		rs->md.recovery_cp = test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)
1691				     ? MaxSector : dev_sectors;
1692}
1693
1694static void do_table_event(struct work_struct *ws)
1695{
1696	struct raid_set *rs = container_of(ws, struct raid_set, md.event_work);
1697
1698	smp_rmb(); /* Make sure we access most actual mddev properties */
1699	if (!rs_is_reshaping(rs)) {
1700		if (rs_is_raid10(rs))
1701			rs_set_rdev_sectors(rs);
1702		rs_set_capacity(rs);
1703	}
1704	dm_table_event(rs->ti->table);
1705}
1706
1707/*
1708 * Make sure a valid takover (level switch) is being requested on @rs
1709 *
1710 * Conversions of raid sets from one MD personality to another
1711 * have to conform to restrictions which are enforced here.
1712 */
1713static int rs_check_takeover(struct raid_set *rs)
1714{
1715	struct mddev *mddev = &rs->md;
1716	unsigned int near_copies;
1717
1718	if (rs->md.degraded) {
1719		rs->ti->error = "Can't takeover degraded raid set";
1720		return -EPERM;
1721	}
1722
1723	if (rs_is_reshaping(rs)) {
1724		rs->ti->error = "Can't takeover reshaping raid set";
1725		return -EPERM;
1726	}
1727
1728	switch (mddev->level) {
1729	case 0:
1730		/* raid0 -> raid1/5 with one disk */
1731		if ((mddev->new_level == 1 || mddev->new_level == 5) &&
1732		    mddev->raid_disks == 1)
1733			return 0;
1734
1735		/* raid0 -> raid10 */
1736		if (mddev->new_level == 10 &&
1737		    !(rs->raid_disks % mddev->raid_disks))
1738			return 0;
1739
1740		/* raid0 with multiple disks -> raid4/5/6 */
1741		if (__within_range(mddev->new_level, 4, 6) &&
1742		    mddev->new_layout == ALGORITHM_PARITY_N &&
1743		    mddev->raid_disks > 1)
1744			return 0;
1745
1746		break;
1747
1748	case 10:
1749		/* Can't takeover raid10_offset! */
1750		if (__is_raid10_offset(mddev->layout))
1751			break;
1752
1753		near_copies = __raid10_near_copies(mddev->layout);
1754
1755		/* raid10* -> raid0 */
1756		if (mddev->new_level == 0) {
1757			/* Can takeover raid10_near with raid disks divisable by data copies! */
1758			if (near_copies > 1 &&
1759			    !(mddev->raid_disks % near_copies)) {
1760				mddev->raid_disks /= near_copies;
1761				mddev->delta_disks = mddev->raid_disks;
1762				return 0;
1763			}
1764
1765			/* Can takeover raid10_far */
1766			if (near_copies == 1 &&
1767			    __raid10_far_copies(mddev->layout) > 1)
1768				return 0;
1769
1770			break;
1771		}
1772
1773		/* raid10_{near,far} -> raid1 */
1774		if (mddev->new_level == 1 &&
1775		    max(near_copies, __raid10_far_copies(mddev->layout)) == mddev->raid_disks)
1776			return 0;
1777
1778		/* raid10_{near,far} with 2 disks -> raid4/5 */
1779		if (__within_range(mddev->new_level, 4, 5) &&
1780		    mddev->raid_disks == 2)
1781			return 0;
1782		break;
1783
1784	case 1:
1785		/* raid1 with 2 disks -> raid4/5 */
1786		if (__within_range(mddev->new_level, 4, 5) &&
1787		    mddev->raid_disks == 2) {
1788			mddev->degraded = 1;
1789			return 0;
1790		}
1791
1792		/* raid1 -> raid0 */
1793		if (mddev->new_level == 0 &&
1794		    mddev->raid_disks == 1)
1795			return 0;
1796
1797		/* raid1 -> raid10 */
1798		if (mddev->new_level == 10)
1799			return 0;
1800		break;
1801
1802	case 4:
1803		/* raid4 -> raid0 */
1804		if (mddev->new_level == 0)
1805			return 0;
1806
1807		/* raid4 -> raid1/5 with 2 disks */
1808		if ((mddev->new_level == 1 || mddev->new_level == 5) &&
1809		    mddev->raid_disks == 2)
1810			return 0;
1811
1812		/* raid4 -> raid5/6 with parity N */
1813		if (__within_range(mddev->new_level, 5, 6) &&
1814		    mddev->layout == ALGORITHM_PARITY_N)
1815			return 0;
1816		break;
1817
1818	case 5:
1819		/* raid5 with parity N -> raid0 */
1820		if (mddev->new_level == 0 &&
1821		    mddev->layout == ALGORITHM_PARITY_N)
1822			return 0;
1823
1824		/* raid5 with parity N -> raid4 */
1825		if (mddev->new_level == 4 &&
1826		    mddev->layout == ALGORITHM_PARITY_N)
1827			return 0;
1828
1829		/* raid5 with 2 disks -> raid1/4/10 */
1830		if ((mddev->new_level == 1 || mddev->new_level == 4 || mddev->new_level == 10) &&
1831		    mddev->raid_disks == 2)
1832			return 0;
1833
1834		/* raid5_* ->  raid6_*_6 with Q-Syndrome N (e.g. raid5_ra -> raid6_ra_6 */
1835		if (mddev->new_level == 6 &&
1836		    ((mddev->layout == ALGORITHM_PARITY_N && mddev->new_layout == ALGORITHM_PARITY_N) ||
1837		      __within_range(mddev->new_layout, ALGORITHM_LEFT_ASYMMETRIC_6, ALGORITHM_RIGHT_SYMMETRIC_6)))
1838			return 0;
1839		break;
1840
1841	case 6:
1842		/* raid6 with parity N -> raid0 */
1843		if (mddev->new_level == 0 &&
1844		    mddev->layout == ALGORITHM_PARITY_N)
1845			return 0;
1846
1847		/* raid6 with parity N -> raid4 */
1848		if (mddev->new_level == 4 &&
1849		    mddev->layout == ALGORITHM_PARITY_N)
1850			return 0;
1851
1852		/* raid6_*_n with Q-Syndrome N -> raid5_* */
1853		if (mddev->new_level == 5 &&
1854		    ((mddev->layout == ALGORITHM_PARITY_N && mddev->new_layout == ALGORITHM_PARITY_N) ||
1855		     __within_range(mddev->new_layout, ALGORITHM_LEFT_ASYMMETRIC, ALGORITHM_RIGHT_SYMMETRIC)))
1856			return 0;
 
1857
1858	default:
1859		break;
1860	}
1861
1862	rs->ti->error = "takeover not possible";
1863	return -EINVAL;
1864}
1865
1866/* True if @rs requested to be taken over */
1867static bool rs_takeover_requested(struct raid_set *rs)
1868{
1869	return rs->md.new_level != rs->md.level;
1870}
1871
 
 
 
 
 
 
 
 
1872/* True if @rs is requested to reshape by ctr */
1873static bool rs_reshape_requested(struct raid_set *rs)
1874{
1875	bool change;
1876	struct mddev *mddev = &rs->md;
1877
1878	if (rs_takeover_requested(rs))
1879		return false;
1880
1881	if (rs_is_raid0(rs))
1882		return false;
1883
1884	change = mddev->new_layout != mddev->layout ||
1885		 mddev->new_chunk_sectors != mddev->chunk_sectors ||
1886		 rs->delta_disks;
1887
1888	/* Historical case to support raid1 reshape without delta disks */
1889	if (rs_is_raid1(rs)) {
1890		if (rs->delta_disks)
1891			return !!rs->delta_disks;
1892
1893		return !change &&
1894		       mddev->raid_disks != rs->raid_disks;
1895	}
1896
1897	if (rs_is_raid10(rs))
1898		return change &&
1899		       !__is_raid10_far(mddev->new_layout) &&
1900		       rs->delta_disks >= 0;
1901
1902	return change;
1903}
1904
1905/*  Features */
1906#define	FEATURE_FLAG_SUPPORTS_V190	0x1 /* Supports extended superblock */
1907
1908/* State flags for sb->flags */
1909#define	SB_FLAG_RESHAPE_ACTIVE		0x1
1910#define	SB_FLAG_RESHAPE_BACKWARDS	0x2
1911
1912/*
1913 * This structure is never routinely used by userspace, unlike md superblocks.
1914 * Devices with this superblock should only ever be accessed via device-mapper.
1915 */
1916#define DM_RAID_MAGIC 0x64526D44
1917struct dm_raid_superblock {
1918	__le32 magic;		/* "DmRd" */
1919	__le32 compat_features;	/* Used to indicate compatible features (like 1.9.0 ondisk metadata extension) */
1920
1921	__le32 num_devices;	/* Number of devices in this raid set. (Max 64) */
1922	__le32 array_position;	/* The position of this drive in the raid set */
1923
1924	__le64 events;		/* Incremented by md when superblock updated */
1925	__le64 failed_devices;	/* Pre 1.9.0 part of bit field of devices to */
1926				/* indicate failures (see extension below) */
1927
1928	/*
1929	 * This offset tracks the progress of the repair or replacement of
1930	 * an individual drive.
1931	 */
1932	__le64 disk_recovery_offset;
1933
1934	/*
1935	 * This offset tracks the progress of the initial raid set
1936	 * synchronisation/parity calculation.
1937	 */
1938	__le64 array_resync_offset;
1939
1940	/*
1941	 * raid characteristics
1942	 */
1943	__le32 level;
1944	__le32 layout;
1945	__le32 stripe_sectors;
1946
1947	/********************************************************************
1948	 * BELOW FOLLOW V1.9.0 EXTENSIONS TO THE PRISTINE SUPERBLOCK FORMAT!!!
1949	 *
1950	 * FEATURE_FLAG_SUPPORTS_V190 in the compat_features member indicates that those exist
1951	 */
1952
1953	__le32 flags; /* Flags defining array states for reshaping */
1954
1955	/*
1956	 * This offset tracks the progress of a raid
1957	 * set reshape in order to be able to restart it
1958	 */
1959	__le64 reshape_position;
1960
1961	/*
1962	 * These define the properties of the array in case of an interrupted reshape
1963	 */
1964	__le32 new_level;
1965	__le32 new_layout;
1966	__le32 new_stripe_sectors;
1967	__le32 delta_disks;
1968
1969	__le64 array_sectors; /* Array size in sectors */
1970
1971	/*
1972	 * Sector offsets to data on devices (reshaping).
1973	 * Needed to support out of place reshaping, thus
1974	 * not writing over any stripes whilst converting
1975	 * them from old to new layout
1976	 */
1977	__le64 data_offset;
1978	__le64 new_data_offset;
1979
1980	__le64 sectors; /* Used device size in sectors */
1981
1982	/*
1983	 * Additonal Bit field of devices indicating failures to support
1984	 * up to 256 devices with the 1.9.0 on-disk metadata format
1985	 */
1986	__le64 extended_failed_devices[DISKS_ARRAY_ELEMS - 1];
1987
1988	__le32 incompat_features;	/* Used to indicate any incompatible features */
1989
1990	/* Always set rest up to logical block size to 0 when writing (see get_metadata_device() below). */
1991} __packed;
1992
1993/*
1994 * Check for reshape constraints on raid set @rs:
1995 *
1996 * - reshape function non-existent
1997 * - degraded set
1998 * - ongoing recovery
1999 * - ongoing reshape
2000 *
2001 * Returns 0 if none or -EPERM if given constraint
2002 * and error message reference in @errmsg
2003 */
2004static int rs_check_reshape(struct raid_set *rs)
2005{
2006	struct mddev *mddev = &rs->md;
2007
2008	if (!mddev->pers || !mddev->pers->check_reshape)
2009		rs->ti->error = "Reshape not supported";
2010	else if (mddev->degraded)
2011		rs->ti->error = "Can't reshape degraded raid set";
2012	else if (rs_is_recovering(rs))
2013		rs->ti->error = "Convert request on recovering raid set prohibited";
2014	else if (rs_is_reshaping(rs))
2015		rs->ti->error = "raid set already reshaping!";
2016	else if (!(rs_is_raid1(rs) || rs_is_raid10(rs) || rs_is_raid456(rs)))
2017		rs->ti->error = "Reshaping only supported for raid1/4/5/6/10";
2018	else
2019		return 0;
2020
2021	return -EPERM;
2022}
2023
2024static int read_disk_sb(struct md_rdev *rdev, int size, bool force_reload)
2025{
2026	BUG_ON(!rdev->sb_page);
2027
2028	if (rdev->sb_loaded && !force_reload)
2029		return 0;
2030
2031	rdev->sb_loaded = 0;
2032
2033	if (!sync_page_io(rdev, 0, size, rdev->sb_page, REQ_OP_READ, 0, true)) {
2034		DMERR("Failed to read superblock of device at position %d",
2035		      rdev->raid_disk);
2036		md_error(rdev->mddev, rdev);
2037		set_bit(Faulty, &rdev->flags);
2038		return -EIO;
2039	}
2040
2041	rdev->sb_loaded = 1;
2042
2043	return 0;
2044}
2045
2046static void sb_retrieve_failed_devices(struct dm_raid_superblock *sb, uint64_t *failed_devices)
2047{
2048	failed_devices[0] = le64_to_cpu(sb->failed_devices);
2049	memset(failed_devices + 1, 0, sizeof(sb->extended_failed_devices));
2050
2051	if (le32_to_cpu(sb->compat_features) & FEATURE_FLAG_SUPPORTS_V190) {
2052		int i = ARRAY_SIZE(sb->extended_failed_devices);
2053
2054		while (i--)
2055			failed_devices[i+1] = le64_to_cpu(sb->extended_failed_devices[i]);
2056	}
2057}
2058
2059static void sb_update_failed_devices(struct dm_raid_superblock *sb, uint64_t *failed_devices)
2060{
2061	int i = ARRAY_SIZE(sb->extended_failed_devices);
2062
2063	sb->failed_devices = cpu_to_le64(failed_devices[0]);
2064	while (i--)
2065		sb->extended_failed_devices[i] = cpu_to_le64(failed_devices[i+1]);
2066}
2067
2068/*
2069 * Synchronize the superblock members with the raid set properties
2070 *
2071 * All superblock data is little endian.
2072 */
2073static void super_sync(struct mddev *mddev, struct md_rdev *rdev)
2074{
2075	bool update_failed_devices = false;
2076	unsigned int i;
2077	uint64_t failed_devices[DISKS_ARRAY_ELEMS];
2078	struct dm_raid_superblock *sb;
2079	struct raid_set *rs = container_of(mddev, struct raid_set, md);
2080
2081	/* No metadata device, no superblock */
2082	if (!rdev->meta_bdev)
2083		return;
2084
2085	BUG_ON(!rdev->sb_page);
2086
2087	sb = page_address(rdev->sb_page);
2088
2089	sb_retrieve_failed_devices(sb, failed_devices);
2090
2091	for (i = 0; i < rs->raid_disks; i++)
2092		if (!rs->dev[i].data_dev || test_bit(Faulty, &rs->dev[i].rdev.flags)) {
2093			update_failed_devices = true;
2094			set_bit(i, (void *) failed_devices);
2095		}
2096
2097	if (update_failed_devices)
2098		sb_update_failed_devices(sb, failed_devices);
2099
2100	sb->magic = cpu_to_le32(DM_RAID_MAGIC);
2101	sb->compat_features = cpu_to_le32(FEATURE_FLAG_SUPPORTS_V190);
2102
2103	sb->num_devices = cpu_to_le32(mddev->raid_disks);
2104	sb->array_position = cpu_to_le32(rdev->raid_disk);
2105
2106	sb->events = cpu_to_le64(mddev->events);
2107
2108	sb->disk_recovery_offset = cpu_to_le64(rdev->recovery_offset);
2109	sb->array_resync_offset = cpu_to_le64(mddev->recovery_cp);
2110
2111	sb->level = cpu_to_le32(mddev->level);
2112	sb->layout = cpu_to_le32(mddev->layout);
2113	sb->stripe_sectors = cpu_to_le32(mddev->chunk_sectors);
2114
2115	/********************************************************************
2116	 * BELOW FOLLOW V1.9.0 EXTENSIONS TO THE PRISTINE SUPERBLOCK FORMAT!!!
2117	 *
2118	 * FEATURE_FLAG_SUPPORTS_V190 in the compat_features member indicates that those exist
2119	 */
2120	sb->new_level = cpu_to_le32(mddev->new_level);
2121	sb->new_layout = cpu_to_le32(mddev->new_layout);
2122	sb->new_stripe_sectors = cpu_to_le32(mddev->new_chunk_sectors);
2123
2124	sb->delta_disks = cpu_to_le32(mddev->delta_disks);
2125
2126	smp_rmb(); /* Make sure we access most recent reshape position */
2127	sb->reshape_position = cpu_to_le64(mddev->reshape_position);
2128	if (le64_to_cpu(sb->reshape_position) != MaxSector) {
2129		/* Flag ongoing reshape */
2130		sb->flags |= cpu_to_le32(SB_FLAG_RESHAPE_ACTIVE);
2131
2132		if (mddev->delta_disks < 0 || mddev->reshape_backwards)
2133			sb->flags |= cpu_to_le32(SB_FLAG_RESHAPE_BACKWARDS);
2134	} else {
2135		/* Clear reshape flags */
2136		sb->flags &= ~(cpu_to_le32(SB_FLAG_RESHAPE_ACTIVE|SB_FLAG_RESHAPE_BACKWARDS));
2137	}
2138
2139	sb->array_sectors = cpu_to_le64(mddev->array_sectors);
2140	sb->data_offset = cpu_to_le64(rdev->data_offset);
2141	sb->new_data_offset = cpu_to_le64(rdev->new_data_offset);
2142	sb->sectors = cpu_to_le64(rdev->sectors);
2143	sb->incompat_features = cpu_to_le32(0);
2144
2145	/* Zero out the rest of the payload after the size of the superblock */
2146	memset(sb + 1, 0, rdev->sb_size - sizeof(*sb));
2147}
2148
2149/*
2150 * super_load
2151 *
2152 * This function creates a superblock if one is not found on the device
2153 * and will decide which superblock to use if there's a choice.
2154 *
2155 * Return: 1 if use rdev, 0 if use refdev, -Exxx otherwise
2156 */
2157static int super_load(struct md_rdev *rdev, struct md_rdev *refdev)
2158{
2159	int r;
2160	struct dm_raid_superblock *sb;
2161	struct dm_raid_superblock *refsb;
2162	uint64_t events_sb, events_refsb;
2163
2164	r = read_disk_sb(rdev, rdev->sb_size, false);
2165	if (r)
2166		return r;
2167
2168	sb = page_address(rdev->sb_page);
2169
2170	/*
2171	 * Two cases that we want to write new superblocks and rebuild:
2172	 * 1) New device (no matching magic number)
2173	 * 2) Device specified for rebuild (!In_sync w/ offset == 0)
2174	 */
2175	if ((sb->magic != cpu_to_le32(DM_RAID_MAGIC)) ||
2176	    (!test_bit(In_sync, &rdev->flags) && !rdev->recovery_offset)) {
2177		super_sync(rdev->mddev, rdev);
2178
2179		set_bit(FirstUse, &rdev->flags);
2180		sb->compat_features = cpu_to_le32(FEATURE_FLAG_SUPPORTS_V190);
2181
2182		/* Force writing of superblocks to disk */
2183		set_bit(MD_SB_CHANGE_DEVS, &rdev->mddev->sb_flags);
2184
2185		/* Any superblock is better than none, choose that if given */
2186		return refdev ? 0 : 1;
2187	}
2188
2189	if (!refdev)
2190		return 1;
2191
2192	events_sb = le64_to_cpu(sb->events);
2193
2194	refsb = page_address(refdev->sb_page);
2195	events_refsb = le64_to_cpu(refsb->events);
2196
2197	return (events_sb > events_refsb) ? 1 : 0;
2198}
2199
2200static int super_init_validation(struct raid_set *rs, struct md_rdev *rdev)
2201{
2202	int role;
2203	unsigned int d;
2204	struct mddev *mddev = &rs->md;
2205	uint64_t events_sb;
2206	uint64_t failed_devices[DISKS_ARRAY_ELEMS];
2207	struct dm_raid_superblock *sb;
2208	uint32_t new_devs = 0, rebuild_and_new = 0, rebuilds = 0;
2209	struct md_rdev *r;
2210	struct dm_raid_superblock *sb2;
2211
2212	sb = page_address(rdev->sb_page);
2213	events_sb = le64_to_cpu(sb->events);
2214
2215	/*
2216	 * Initialise to 1 if this is a new superblock.
2217	 */
2218	mddev->events = events_sb ? : 1;
2219
2220	mddev->reshape_position = MaxSector;
2221
2222	mddev->raid_disks = le32_to_cpu(sb->num_devices);
2223	mddev->level = le32_to_cpu(sb->level);
2224	mddev->layout = le32_to_cpu(sb->layout);
2225	mddev->chunk_sectors = le32_to_cpu(sb->stripe_sectors);
2226
2227	/*
2228	 * Reshaping is supported, e.g. reshape_position is valid
2229	 * in superblock and superblock content is authoritative.
2230	 */
2231	if (le32_to_cpu(sb->compat_features) & FEATURE_FLAG_SUPPORTS_V190) {
2232		/* Superblock is authoritative wrt given raid set layout! */
2233		mddev->new_level = le32_to_cpu(sb->new_level);
2234		mddev->new_layout = le32_to_cpu(sb->new_layout);
2235		mddev->new_chunk_sectors = le32_to_cpu(sb->new_stripe_sectors);
2236		mddev->delta_disks = le32_to_cpu(sb->delta_disks);
2237		mddev->array_sectors = le64_to_cpu(sb->array_sectors);
2238
2239		/* raid was reshaping and got interrupted */
2240		if (le32_to_cpu(sb->flags) & SB_FLAG_RESHAPE_ACTIVE) {
2241			if (test_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags)) {
2242				DMERR("Reshape requested but raid set is still reshaping");
2243				return -EINVAL;
2244			}
2245
2246			if (mddev->delta_disks < 0 ||
2247			    (!mddev->delta_disks && (le32_to_cpu(sb->flags) & SB_FLAG_RESHAPE_BACKWARDS)))
2248				mddev->reshape_backwards = 1;
2249			else
2250				mddev->reshape_backwards = 0;
2251
2252			mddev->reshape_position = le64_to_cpu(sb->reshape_position);
2253			rs->raid_type = get_raid_type_by_ll(mddev->level, mddev->layout);
2254		}
2255
2256	} else {
2257		/*
2258		 * No takeover/reshaping, because we don't have the extended v1.9.0 metadata
2259		 */
2260		struct raid_type *rt_cur = get_raid_type_by_ll(mddev->level, mddev->layout);
2261		struct raid_type *rt_new = get_raid_type_by_ll(mddev->new_level, mddev->new_layout);
2262
2263		if (rs_takeover_requested(rs)) {
2264			if (rt_cur && rt_new)
2265				DMERR("Takeover raid sets from %s to %s not yet supported by metadata. (raid level change)",
2266				      rt_cur->name, rt_new->name);
2267			else
2268				DMERR("Takeover raid sets not yet supported by metadata. (raid level change)");
2269			return -EINVAL;
2270		} else if (rs_reshape_requested(rs)) {
2271			DMERR("Reshaping raid sets not yet supported by metadata. (raid layout change keeping level)");
2272			if (mddev->layout != mddev->new_layout) {
2273				if (rt_cur && rt_new)
2274					DMERR("	 current layout %s vs new layout %s",
2275					      rt_cur->name, rt_new->name);
2276				else
2277					DMERR("	 current layout 0x%X vs new layout 0x%X",
2278					      le32_to_cpu(sb->layout), mddev->new_layout);
2279			}
2280			if (mddev->chunk_sectors != mddev->new_chunk_sectors)
2281				DMERR("	 current stripe sectors %u vs new stripe sectors %u",
2282				      mddev->chunk_sectors, mddev->new_chunk_sectors);
2283			if (rs->delta_disks)
2284				DMERR("	 current %u disks vs new %u disks",
2285				      mddev->raid_disks, mddev->raid_disks + rs->delta_disks);
2286			if (rs_is_raid10(rs)) {
2287				DMERR("	 Old layout: %s w/ %u copies",
2288				      raid10_md_layout_to_format(mddev->layout),
2289				      raid10_md_layout_to_copies(mddev->layout));
2290				DMERR("	 New layout: %s w/ %u copies",
2291				      raid10_md_layout_to_format(mddev->new_layout),
2292				      raid10_md_layout_to_copies(mddev->new_layout));
2293			}
2294			return -EINVAL;
2295		}
2296
2297		DMINFO("Discovered old metadata format; upgrading to extended metadata format");
2298	}
2299
2300	if (!test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))
2301		mddev->recovery_cp = le64_to_cpu(sb->array_resync_offset);
2302
2303	/*
2304	 * During load, we set FirstUse if a new superblock was written.
2305	 * There are two reasons we might not have a superblock:
2306	 * 1) The raid set is brand new - in which case, all of the
2307	 *    devices must have their In_sync bit set.	Also,
2308	 *    recovery_cp must be 0, unless forced.
2309	 * 2) This is a new device being added to an old raid set
2310	 *    and the new device needs to be rebuilt - in which
2311	 *    case the In_sync bit will /not/ be set and
2312	 *    recovery_cp must be MaxSector.
2313	 * 3) This is/are a new device(s) being added to an old
2314	 *    raid set during takeover to a higher raid level
2315	 *    to provide capacity for redundancy or during reshape
2316	 *    to add capacity to grow the raid set.
2317	 */
2318	d = 0;
2319	rdev_for_each(r, mddev) {
2320		if (test_bit(Journal, &rdev->flags))
2321			continue;
2322
2323		if (test_bit(FirstUse, &r->flags))
2324			new_devs++;
2325
2326		if (!test_bit(In_sync, &r->flags)) {
2327			DMINFO("Device %d specified for rebuild; clearing superblock",
2328				r->raid_disk);
2329			rebuilds++;
2330
2331			if (test_bit(FirstUse, &r->flags))
2332				rebuild_and_new++;
2333		}
2334
2335		d++;
2336	}
2337
2338	if (new_devs == rs->raid_disks || !rebuilds) {
2339		/* Replace a broken device */
2340		if (new_devs == rs->raid_disks) {
2341			DMINFO("Superblocks created for new raid set");
2342			set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
2343		} else if (new_devs != rebuilds &&
2344			   new_devs != rs->delta_disks) {
2345			DMERR("New device injected into existing raid set without "
2346			      "'delta_disks' or 'rebuild' parameter specified");
2347			return -EINVAL;
2348		}
2349	} else if (new_devs && new_devs != rebuilds) {
2350		DMERR("%u 'rebuild' devices cannot be injected into"
2351		      " a raid set with %u other first-time devices",
2352		      rebuilds, new_devs);
2353		return -EINVAL;
2354	} else if (rebuilds) {
2355		if (rebuild_and_new && rebuilds != rebuild_and_new) {
2356			DMERR("new device%s provided without 'rebuild'",
2357			      new_devs > 1 ? "s" : "");
2358			return -EINVAL;
2359		} else if (!test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags) && rs_is_recovering(rs)) {
2360			DMERR("'rebuild' specified while raid set is not in-sync (recovery_cp=%llu)",
2361			      (unsigned long long) mddev->recovery_cp);
2362			return -EINVAL;
2363		} else if (rs_is_reshaping(rs)) {
2364			DMERR("'rebuild' specified while raid set is being reshaped (reshape_position=%llu)",
2365			      (unsigned long long) mddev->reshape_position);
2366			return -EINVAL;
2367		}
2368	}
2369
2370	/*
2371	 * Now we set the Faulty bit for those devices that are
2372	 * recorded in the superblock as failed.
2373	 */
2374	sb_retrieve_failed_devices(sb, failed_devices);
2375	rdev_for_each(r, mddev) {
2376		if (test_bit(Journal, &rdev->flags) ||
2377		    !r->sb_page)
2378			continue;
2379		sb2 = page_address(r->sb_page);
2380		sb2->failed_devices = 0;
2381		memset(sb2->extended_failed_devices, 0, sizeof(sb2->extended_failed_devices));
2382
2383		/*
2384		 * Check for any device re-ordering.
2385		 */
2386		if (!test_bit(FirstUse, &r->flags) && (r->raid_disk >= 0)) {
2387			role = le32_to_cpu(sb2->array_position);
2388			if (role < 0)
2389				continue;
2390
2391			if (role != r->raid_disk) {
2392				if (rs_is_raid10(rs) && __is_raid10_near(mddev->layout)) {
2393					if (mddev->raid_disks % __raid10_near_copies(mddev->layout) ||
2394					    rs->raid_disks % rs->raid10_copies) {
2395						rs->ti->error =
2396							"Cannot change raid10 near set to odd # of devices!";
2397						return -EINVAL;
2398					}
2399
2400					sb2->array_position = cpu_to_le32(r->raid_disk);
2401
2402				} else if (!(rs_is_raid10(rs) && rt_is_raid0(rs->raid_type)) &&
2403					   !(rs_is_raid0(rs) && rt_is_raid10(rs->raid_type)) &&
2404					   !rt_is_raid1(rs->raid_type)) {
2405					rs->ti->error = "Cannot change device positions in raid set";
2406					return -EINVAL;
2407				}
2408
2409				DMINFO("raid device #%d now at position #%d", role, r->raid_disk);
2410			}
2411
2412			/*
2413			 * Partial recovery is performed on
2414			 * returning failed devices.
2415			 */
2416			if (test_bit(role, (void *) failed_devices))
2417				set_bit(Faulty, &r->flags);
2418		}
2419	}
2420
2421	return 0;
2422}
2423
2424static int super_validate(struct raid_set *rs, struct md_rdev *rdev)
2425{
2426	struct mddev *mddev = &rs->md;
2427	struct dm_raid_superblock *sb;
2428
2429	if (rs_is_raid0(rs) || !rdev->sb_page || rdev->raid_disk < 0)
2430		return 0;
2431
2432	sb = page_address(rdev->sb_page);
2433
2434	/*
2435	 * If mddev->events is not set, we know we have not yet initialized
2436	 * the array.
2437	 */
2438	if (!mddev->events && super_init_validation(rs, rdev))
2439		return -EINVAL;
2440
2441	if (le32_to_cpu(sb->compat_features) &&
2442	    le32_to_cpu(sb->compat_features) != FEATURE_FLAG_SUPPORTS_V190) {
2443		rs->ti->error = "Unable to assemble array: Unknown flag(s) in compatible feature flags";
2444		return -EINVAL;
2445	}
2446
2447	if (sb->incompat_features) {
2448		rs->ti->error = "Unable to assemble array: No incompatible feature flags supported yet";
2449		return -EINVAL;
2450	}
2451
2452	/* Enable bitmap creation on @rs unless no metadevs or raid0 or journaled raid4/5/6 set. */
2453	mddev->bitmap_info.offset = (rt_is_raid0(rs->raid_type) || rs->journal_dev.dev) ? 0 : to_sector(4096);
2454	mddev->bitmap_info.default_offset = mddev->bitmap_info.offset;
2455
2456	if (!test_and_clear_bit(FirstUse, &rdev->flags)) {
2457		/*
2458		 * Retrieve rdev size stored in superblock to be prepared for shrink.
2459		 * Check extended superblock members are present otherwise the size
2460		 * will not be set!
2461		 */
2462		if (le32_to_cpu(sb->compat_features) & FEATURE_FLAG_SUPPORTS_V190)
2463			rdev->sectors = le64_to_cpu(sb->sectors);
2464
2465		rdev->recovery_offset = le64_to_cpu(sb->disk_recovery_offset);
2466		if (rdev->recovery_offset == MaxSector)
2467			set_bit(In_sync, &rdev->flags);
2468		/*
2469		 * If no reshape in progress -> we're recovering single
2470		 * disk(s) and have to set the device(s) to out-of-sync
2471		 */
2472		else if (!rs_is_reshaping(rs))
2473			clear_bit(In_sync, &rdev->flags); /* Mandatory for recovery */
2474	}
2475
2476	/*
2477	 * If a device comes back, set it as not In_sync and no longer faulty.
2478	 */
2479	if (test_and_clear_bit(Faulty, &rdev->flags)) {
2480		rdev->recovery_offset = 0;
2481		clear_bit(In_sync, &rdev->flags);
2482		rdev->saved_raid_disk = rdev->raid_disk;
2483	}
2484
2485	/* Reshape support -> restore repective data offsets */
2486	rdev->data_offset = le64_to_cpu(sb->data_offset);
2487	rdev->new_data_offset = le64_to_cpu(sb->new_data_offset);
2488
2489	return 0;
2490}
2491
2492/*
2493 * Analyse superblocks and select the freshest.
2494 */
2495static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
2496{
2497	int r;
2498	struct md_rdev *rdev, *freshest;
2499	struct mddev *mddev = &rs->md;
2500
2501	freshest = NULL;
2502	rdev_for_each(rdev, mddev) {
2503		if (test_bit(Journal, &rdev->flags))
2504			continue;
2505
2506		if (!rdev->meta_bdev)
2507			continue;
2508
2509		/* Set superblock offset/size for metadata device. */
2510		rdev->sb_start = 0;
2511		rdev->sb_size = bdev_logical_block_size(rdev->meta_bdev);
2512		if (rdev->sb_size < sizeof(struct dm_raid_superblock) || rdev->sb_size > PAGE_SIZE) {
2513			DMERR("superblock size of a logical block is no longer valid");
2514			return -EINVAL;
2515		}
2516
2517		/*
2518		 * Skipping super_load due to CTR_FLAG_SYNC will cause
2519		 * the array to undergo initialization again as
2520		 * though it were new.	This is the intended effect
2521		 * of the "sync" directive.
2522		 *
2523		 * With reshaping capability added, we must ensure that
2524		 * that the "sync" directive is disallowed during the reshape.
2525		 */
2526		if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags))
2527			continue;
2528
2529		r = super_load(rdev, freshest);
2530
2531		switch (r) {
2532		case 1:
2533			freshest = rdev;
2534			break;
2535		case 0:
2536			break;
2537		default:
2538			/* This is a failure to read the superblock from the metadata device. */
2539			/*
2540			 * We have to keep any raid0 data/metadata device pairs or
2541			 * the MD raid0 personality will fail to start the array.
2542			 */
2543			if (rs_is_raid0(rs))
2544				continue;
2545
2546			/*
2547			 * We keep the dm_devs to be able to emit the device tuple
2548			 * properly on the table line in raid_status() (rather than
2549			 * mistakenly acting as if '- -' got passed into the constructor).
2550			 *
2551			 * The rdev has to stay on the same_set list to allow for
2552			 * the attempt to restore faulty devices on second resume.
2553			 */
2554			rdev->raid_disk = rdev->saved_raid_disk = -1;
2555			break;
2556		}
2557	}
2558
2559	if (!freshest)
2560		return 0;
2561
2562	/*
2563	 * Validation of the freshest device provides the source of
2564	 * validation for the remaining devices.
2565	 */
2566	rs->ti->error = "Unable to assemble array: Invalid superblocks";
2567	if (super_validate(rs, freshest))
2568		return -EINVAL;
2569
2570	if (validate_raid_redundancy(rs)) {
2571		rs->ti->error = "Insufficient redundancy to activate array";
2572		return -EINVAL;
2573	}
2574
2575	rdev_for_each(rdev, mddev)
2576		if (!test_bit(Journal, &rdev->flags) &&
2577		    rdev != freshest &&
2578		    super_validate(rs, rdev))
2579			return -EINVAL;
2580	return 0;
2581}
2582
2583/*
2584 * Adjust data_offset and new_data_offset on all disk members of @rs
2585 * for out of place reshaping if requested by contructor
2586 *
2587 * We need free space at the beginning of each raid disk for forward
2588 * and at the end for backward reshapes which userspace has to provide
2589 * via remapping/reordering of space.
2590 */
2591static int rs_adjust_data_offsets(struct raid_set *rs)
2592{
2593	sector_t data_offset = 0, new_data_offset = 0;
2594	struct md_rdev *rdev;
2595
2596	/* Constructor did not request data offset change */
2597	if (!test_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags)) {
2598		if (!rs_is_reshapable(rs))
2599			goto out;
2600
2601		return 0;
2602	}
2603
2604	/* HM FIXME: get In_Sync raid_dev? */
2605	rdev = &rs->dev[0].rdev;
2606
2607	if (rs->delta_disks < 0) {
2608		/*
2609		 * Removing disks (reshaping backwards):
2610		 *
2611		 * - before reshape: data is at offset 0 and free space
2612		 *		     is at end of each component LV
2613		 *
2614		 * - after reshape: data is at offset rs->data_offset != 0 on each component LV
2615		 */
2616		data_offset = 0;
2617		new_data_offset = rs->data_offset;
2618
2619	} else if (rs->delta_disks > 0) {
2620		/*
2621		 * Adding disks (reshaping forwards):
2622		 *
2623		 * - before reshape: data is at offset rs->data_offset != 0 and
2624		 *		     free space is at begin of each component LV
2625		 *
2626		 * - after reshape: data is at offset 0 on each component LV
2627		 */
2628		data_offset = rs->data_offset;
2629		new_data_offset = 0;
2630
2631	} else {
2632		/*
2633		 * User space passes in 0 for data offset after having removed reshape space
2634		 *
2635		 * - or - (data offset != 0)
2636		 *
2637		 * Changing RAID layout or chunk size -> toggle offsets
2638		 *
2639		 * - before reshape: data is at offset rs->data_offset 0 and
2640		 *		     free space is at end of each component LV
2641		 *		     -or-
2642		 *                   data is at offset rs->data_offset != 0 and
2643		 *		     free space is at begin of each component LV
2644		 *
2645		 * - after reshape: data is at offset 0 if it was at offset != 0
2646		 *                  or at offset != 0 if it was at offset 0
2647		 *                  on each component LV
2648		 *
2649		 */
2650		data_offset = rs->data_offset ? rdev->data_offset : 0;
2651		new_data_offset = data_offset ? 0 : rs->data_offset;
2652		set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2653	}
2654
2655	/*
2656	 * Make sure we got a minimum amount of free sectors per device
2657	 */
2658	if (rs->data_offset &&
2659	    to_sector(i_size_read(rdev->bdev->bd_inode)) - rs->md.dev_sectors < MIN_FREE_RESHAPE_SPACE) {
2660		rs->ti->error = data_offset ? "No space for forward reshape" :
2661					      "No space for backward reshape";
2662		return -ENOSPC;
2663	}
2664out:
2665	/*
2666	 * Raise recovery_cp in case data_offset != 0 to
2667	 * avoid false recovery positives in the constructor.
2668	 */
2669	if (rs->md.recovery_cp < rs->md.dev_sectors)
2670		rs->md.recovery_cp += rs->dev[0].rdev.data_offset;
2671
2672	/* Adjust data offsets on all rdevs but on any raid4/5/6 journal device */
2673	rdev_for_each(rdev, &rs->md) {
2674		if (!test_bit(Journal, &rdev->flags)) {
2675			rdev->data_offset = data_offset;
2676			rdev->new_data_offset = new_data_offset;
2677		}
2678	}
2679
2680	return 0;
2681}
2682
2683/* Userpace reordered disks -> adjust raid_disk indexes in @rs */
2684static void __reorder_raid_disk_indexes(struct raid_set *rs)
2685{
2686	int i = 0;
2687	struct md_rdev *rdev;
2688
2689	rdev_for_each(rdev, &rs->md) {
2690		if (!test_bit(Journal, &rdev->flags)) {
2691			rdev->raid_disk = i++;
2692			rdev->saved_raid_disk = rdev->new_raid_disk = -1;
2693		}
2694	}
2695}
2696
2697/*
2698 * Setup @rs for takeover by a different raid level
2699 */
2700static int rs_setup_takeover(struct raid_set *rs)
2701{
2702	struct mddev *mddev = &rs->md;
2703	struct md_rdev *rdev;
2704	unsigned int d = mddev->raid_disks = rs->raid_disks;
2705	sector_t new_data_offset = rs->dev[0].rdev.data_offset ? 0 : rs->data_offset;
2706
2707	if (rt_is_raid10(rs->raid_type)) {
2708		if (rs_is_raid0(rs)) {
2709			/* Userpace reordered disks -> adjust raid_disk indexes */
2710			__reorder_raid_disk_indexes(rs);
2711
2712			/* raid0 -> raid10_far layout */
2713			mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_FAR,
2714								   rs->raid10_copies);
2715		} else if (rs_is_raid1(rs))
2716			/* raid1 -> raid10_near layout */
2717			mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_NEAR,
2718								   rs->raid_disks);
2719		else
2720			return -EINVAL;
2721
2722	}
2723
2724	clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
2725	mddev->recovery_cp = MaxSector;
2726
2727	while (d--) {
2728		rdev = &rs->dev[d].rdev;
2729
2730		if (test_bit(d, (void *) rs->rebuild_disks)) {
2731			clear_bit(In_sync, &rdev->flags);
2732			clear_bit(Faulty, &rdev->flags);
2733			mddev->recovery_cp = rdev->recovery_offset = 0;
2734			/* Bitmap has to be created when we do an "up" takeover */
2735			set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
2736		}
2737
2738		rdev->new_data_offset = new_data_offset;
2739	}
2740
2741	return 0;
2742}
2743
2744/* Prepare @rs for reshape */
2745static int rs_prepare_reshape(struct raid_set *rs)
2746{
2747	bool reshape;
2748	struct mddev *mddev = &rs->md;
2749
2750	if (rs_is_raid10(rs)) {
2751		if (rs->raid_disks != mddev->raid_disks &&
2752		    __is_raid10_near(mddev->layout) &&
2753		    rs->raid10_copies &&
2754		    rs->raid10_copies != __raid10_near_copies(mddev->layout)) {
2755			/*
2756			 * raid disk have to be multiple of data copies to allow this conversion,
2757			 *
2758			 * This is actually not a reshape it is a
2759			 * rebuild of any additional mirrors per group
2760			 */
2761			if (rs->raid_disks % rs->raid10_copies) {
2762				rs->ti->error = "Can't reshape raid10 mirror groups";
2763				return -EINVAL;
2764			}
2765
2766			/* Userpace reordered disks to add/remove mirrors -> adjust raid_disk indexes */
2767			__reorder_raid_disk_indexes(rs);
2768			mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_NEAR,
2769								   rs->raid10_copies);
2770			mddev->new_layout = mddev->layout;
2771			reshape = false;
2772		} else
2773			reshape = true;
2774
2775	} else if (rs_is_raid456(rs))
2776		reshape = true;
2777
2778	else if (rs_is_raid1(rs)) {
2779		if (rs->delta_disks) {
2780			/* Process raid1 via delta_disks */
2781			mddev->degraded = rs->delta_disks < 0 ? -rs->delta_disks : rs->delta_disks;
2782			reshape = true;
2783		} else {
2784			/* Process raid1 without delta_disks */
2785			mddev->raid_disks = rs->raid_disks;
2786			reshape = false;
2787		}
2788	} else {
2789		rs->ti->error = "Called with bogus raid type";
2790		return -EINVAL;
2791	}
2792
2793	if (reshape) {
2794		set_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags);
2795		set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2796	} else if (mddev->raid_disks < rs->raid_disks)
2797		/* Create new superblocks and bitmaps, if any new disks */
2798		set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2799
2800	return 0;
2801}
2802
2803/* Get reshape sectors from data_offsets or raid set */
2804static sector_t _get_reshape_sectors(struct raid_set *rs)
2805{
2806	struct md_rdev *rdev;
2807	sector_t reshape_sectors = 0;
2808
2809	rdev_for_each(rdev, &rs->md)
2810		if (!test_bit(Journal, &rdev->flags)) {
2811			reshape_sectors = (rdev->data_offset > rdev->new_data_offset) ?
2812					rdev->data_offset - rdev->new_data_offset :
2813					rdev->new_data_offset - rdev->data_offset;
2814			break;
2815		}
2816
2817	return max(reshape_sectors, (sector_t) rs->data_offset);
2818}
2819
2820/*
2821 *
2822 * - change raid layout
2823 * - change chunk size
2824 * - add disks
2825 * - remove disks
2826 */
2827static int rs_setup_reshape(struct raid_set *rs)
2828{
2829	int r = 0;
2830	unsigned int cur_raid_devs, d;
2831	sector_t reshape_sectors = _get_reshape_sectors(rs);
2832	struct mddev *mddev = &rs->md;
2833	struct md_rdev *rdev;
2834
2835	mddev->delta_disks = rs->delta_disks;
2836	cur_raid_devs = mddev->raid_disks;
2837
2838	/* Ignore impossible layout change whilst adding/removing disks */
2839	if (mddev->delta_disks &&
2840	    mddev->layout != mddev->new_layout) {
2841		DMINFO("Ignoring invalid layout change with delta_disks=%d", rs->delta_disks);
2842		mddev->new_layout = mddev->layout;
2843	}
2844
2845	/*
2846	 * Adjust array size:
2847	 *
2848	 * - in case of adding disk(s), array size has
2849	 *   to grow after the disk adding reshape,
2850	 *   which'll hapen in the event handler;
2851	 *   reshape will happen forward, so space has to
2852	 *   be available at the beginning of each disk
2853	 *
2854	 * - in case of removing disk(s), array size
2855	 *   has to shrink before starting the reshape,
2856	 *   which'll happen here;
2857	 *   reshape will happen backward, so space has to
2858	 *   be available at the end of each disk
2859	 *
2860	 * - data_offset and new_data_offset are
2861	 *   adjusted for aforementioned out of place
2862	 *   reshaping based on userspace passing in
2863	 *   the "data_offset <sectors>" key/value
2864	 *   pair via the constructor
2865	 */
2866
2867	/* Add disk(s) */
2868	if (rs->delta_disks > 0) {
2869		/* Prepare disks for check in raid4/5/6/10 {check|start}_reshape */
2870		for (d = cur_raid_devs; d < rs->raid_disks; d++) {
2871			rdev = &rs->dev[d].rdev;
2872			clear_bit(In_sync, &rdev->flags);
2873
2874			/*
2875			 * save_raid_disk needs to be -1, or recovery_offset will be set to 0
2876			 * by md, which'll store that erroneously in the superblock on reshape
2877			 */
2878			rdev->saved_raid_disk = -1;
2879			rdev->raid_disk = d;
2880
2881			rdev->sectors = mddev->dev_sectors;
2882			rdev->recovery_offset = rs_is_raid1(rs) ? 0 : MaxSector;
2883		}
2884
2885		mddev->reshape_backwards = 0; /* adding disk(s) -> forward reshape */
2886
2887	/* Remove disk(s) */
2888	} else if (rs->delta_disks < 0) {
2889		r = rs_set_dev_and_array_sectors(rs, rs->ti->len, true);
2890		mddev->reshape_backwards = 1; /* removing disk(s) -> backward reshape */
2891
2892	/* Change layout and/or chunk size */
2893	} else {
2894		/*
2895		 * Reshape layout (e.g. raid5_ls -> raid5_n) and/or chunk size:
2896		 *
2897		 * keeping number of disks and do layout change ->
2898		 *
2899		 * toggle reshape_backward depending on data_offset:
2900		 *
2901		 * - free space upfront -> reshape forward
2902		 *
2903		 * - free space at the end -> reshape backward
2904		 *
2905		 *
2906		 * This utilizes free reshape space avoiding the need
2907		 * for userspace to move (parts of) LV segments in
2908		 * case of layout/chunksize change  (for disk
2909		 * adding/removing reshape space has to be at
2910		 * the proper address (see above with delta_disks):
2911		 *
2912		 * add disk(s)   -> begin
2913		 * remove disk(s)-> end
2914		 */
2915		mddev->reshape_backwards = rs->dev[0].rdev.data_offset ? 0 : 1;
2916	}
2917
2918	/*
2919	 * Adjust device size for forward reshape
2920	 * because md_finish_reshape() reduces it.
2921	 */
2922	if (!mddev->reshape_backwards)
2923		rdev_for_each(rdev, &rs->md)
2924			if (!test_bit(Journal, &rdev->flags))
2925				rdev->sectors += reshape_sectors;
2926
2927	return r;
2928}
2929
2930/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2931 * Enable/disable discard support on RAID set depending on
2932 * RAID level and discard properties of underlying RAID members.
2933 */
2934static void configure_discard_support(struct raid_set *rs)
2935{
2936	int i;
2937	bool raid456;
2938	struct dm_target *ti = rs->ti;
2939
2940	/*
2941	 * XXX: RAID level 4,5,6 require zeroing for safety.
2942	 */
2943	raid456 = rs_is_raid456(rs);
2944
2945	for (i = 0; i < rs->raid_disks; i++) {
2946		struct request_queue *q;
2947
2948		if (!rs->dev[i].rdev.bdev)
2949			continue;
2950
2951		q = bdev_get_queue(rs->dev[i].rdev.bdev);
2952		if (!q || !blk_queue_discard(q))
2953			return;
2954
2955		if (raid456) {
2956			if (!devices_handle_discard_safely) {
2957				DMERR("raid456 discard support disabled due to discard_zeroes_data uncertainty.");
2958				DMERR("Set dm-raid.devices_handle_discard_safely=Y to override.");
2959				return;
2960			}
2961		}
2962	}
2963
2964	ti->num_discard_bios = 1;
2965}
2966
2967/*
2968 * Construct a RAID0/1/10/4/5/6 mapping:
2969 * Args:
2970 *	<raid_type> <#raid_params> <raid_params>{0,}	\
2971 *	<#raid_devs> [<meta_dev1> <dev1>]{1,}
2972 *
2973 * <raid_params> varies by <raid_type>.	 See 'parse_raid_params' for
2974 * details on possible <raid_params>.
2975 *
2976 * Userspace is free to initialize the metadata devices, hence the superblocks to
2977 * enforce recreation based on the passed in table parameters.
2978 *
2979 */
2980static int raid_ctr(struct dm_target *ti, unsigned int argc, char **argv)
2981{
2982	int r;
2983	bool resize = false;
2984	struct raid_type *rt;
2985	unsigned int num_raid_params, num_raid_devs;
2986	sector_t sb_array_sectors, rdev_sectors, reshape_sectors;
2987	struct raid_set *rs = NULL;
2988	const char *arg;
2989	struct rs_layout rs_layout;
2990	struct dm_arg_set as = { argc, argv }, as_nrd;
2991	struct dm_arg _args[] = {
2992		{ 0, as.argc, "Cannot understand number of raid parameters" },
2993		{ 1, 254, "Cannot understand number of raid devices parameters" }
2994	};
2995
2996	arg = dm_shift_arg(&as);
2997	if (!arg) {
2998		ti->error = "No arguments";
2999		return -EINVAL;
3000	}
3001
3002	rt = get_raid_type(arg);
3003	if (!rt) {
3004		ti->error = "Unrecognised raid_type";
3005		return -EINVAL;
3006	}
3007
3008	/* Must have <#raid_params> */
3009	if (dm_read_arg_group(_args, &as, &num_raid_params, &ti->error))
3010		return -EINVAL;
3011
3012	/* number of raid device tupples <meta_dev data_dev> */
3013	as_nrd = as;
3014	dm_consume_args(&as_nrd, num_raid_params);
3015	_args[1].max = (as_nrd.argc - 1) / 2;
3016	if (dm_read_arg(_args + 1, &as_nrd, &num_raid_devs, &ti->error))
3017		return -EINVAL;
3018
3019	if (!__within_range(num_raid_devs, 1, MAX_RAID_DEVICES)) {
3020		ti->error = "Invalid number of supplied raid devices";
3021		return -EINVAL;
3022	}
3023
3024	rs = raid_set_alloc(ti, rt, num_raid_devs);
3025	if (IS_ERR(rs))
3026		return PTR_ERR(rs);
3027
3028	r = parse_raid_params(rs, &as, num_raid_params);
3029	if (r)
3030		goto bad;
3031
3032	r = parse_dev_params(rs, &as);
3033	if (r)
3034		goto bad;
3035
3036	rs->md.sync_super = super_sync;
3037
3038	/*
3039	 * Calculate ctr requested array and device sizes to allow
3040	 * for superblock analysis needing device sizes defined.
3041	 *
3042	 * Any existing superblock will overwrite the array and device sizes
3043	 */
3044	r = rs_set_dev_and_array_sectors(rs, rs->ti->len, false);
3045	if (r)
3046		goto bad;
3047
3048	/* Memorize just calculated, potentially larger sizes to grow the raid set in preresume */
3049	rs->array_sectors = rs->md.array_sectors;
3050	rs->dev_sectors = rs->md.dev_sectors;
3051
3052	/*
3053	 * Backup any new raid set level, layout, ...
3054	 * requested to be able to compare to superblock
3055	 * members for conversion decisions.
3056	 */
3057	rs_config_backup(rs, &rs_layout);
3058
3059	r = analyse_superblocks(ti, rs);
3060	if (r)
3061		goto bad;
3062
3063	/* All in-core metadata now as of current superblocks after calling analyse_superblocks() */
3064	sb_array_sectors = rs->md.array_sectors;
3065	rdev_sectors = __rdev_sectors(rs);
3066	if (!rdev_sectors) {
3067		ti->error = "Invalid rdev size";
3068		r = -EINVAL;
3069		goto bad;
3070	}
3071
3072
3073	reshape_sectors = _get_reshape_sectors(rs);
3074	if (rs->dev_sectors != rdev_sectors) {
3075		resize = (rs->dev_sectors != rdev_sectors - reshape_sectors);
3076		if (rs->dev_sectors > rdev_sectors - reshape_sectors)
3077			set_bit(RT_FLAG_RS_GROW, &rs->runtime_flags);
3078	}
3079
3080	INIT_WORK(&rs->md.event_work, do_table_event);
3081	ti->private = rs;
3082	ti->num_flush_bios = 1;
3083
3084	/* Restore any requested new layout for conversion decision */
3085	rs_config_restore(rs, &rs_layout);
3086
3087	/*
3088	 * Now that we have any superblock metadata available,
3089	 * check for new, recovering, reshaping, to be taken over,
3090	 * to be reshaped or an existing, unchanged raid set to
3091	 * run in sequence.
3092	 */
3093	if (test_bit(MD_ARRAY_FIRST_USE, &rs->md.flags)) {
3094		/* A new raid6 set has to be recovered to ensure proper parity and Q-Syndrome */
3095		if (rs_is_raid6(rs) &&
3096		    test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
3097			ti->error = "'nosync' not allowed for new raid6 set";
3098			r = -EINVAL;
3099			goto bad;
3100		}
3101		rs_setup_recovery(rs, 0);
3102		set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
3103		rs_set_new(rs);
3104	} else if (rs_is_recovering(rs)) {
3105		/* A recovering raid set may be resized */
3106		goto size_check;
3107	} else if (rs_is_reshaping(rs)) {
3108		/* Have to reject size change request during reshape */
3109		if (resize) {
3110			ti->error = "Can't resize a reshaping raid set";
3111			r = -EPERM;
3112			goto bad;
3113		}
3114		/* skip setup rs */
3115	} else if (rs_takeover_requested(rs)) {
3116		if (rs_is_reshaping(rs)) {
3117			ti->error = "Can't takeover a reshaping raid set";
3118			r = -EPERM;
3119			goto bad;
3120		}
3121
3122		/* We can't takeover a journaled raid4/5/6 */
3123		if (test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
3124			ti->error = "Can't takeover a journaled raid4/5/6 set";
3125			r = -EPERM;
3126			goto bad;
3127		}
3128
3129		/*
3130		 * If a takeover is needed, userspace sets any additional
3131		 * devices to rebuild and we can check for a valid request here.
3132		 *
3133		 * If acceptible, set the level to the new requested
3134		 * one, prohibit requesting recovery, allow the raid
3135		 * set to run and store superblocks during resume.
3136		 */
3137		r = rs_check_takeover(rs);
3138		if (r)
3139			goto bad;
3140
3141		r = rs_setup_takeover(rs);
3142		if (r)
3143			goto bad;
3144
3145		set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
3146		/* Takeover ain't recovery, so disable recovery */
3147		rs_setup_recovery(rs, MaxSector);
3148		rs_set_new(rs);
3149	} else if (rs_reshape_requested(rs)) {
3150		/* Only request grow on raid set size extensions, not on reshapes. */
3151		clear_bit(RT_FLAG_RS_GROW, &rs->runtime_flags);
3152
3153		/*
3154		 * No need to check for 'ongoing' takeover here, because takeover
3155		 * is an instant operation as oposed to an ongoing reshape.
3156		 */
3157
3158		/* We can't reshape a journaled raid4/5/6 */
3159		if (test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
3160			ti->error = "Can't reshape a journaled raid4/5/6 set";
3161			r = -EPERM;
3162			goto bad;
3163		}
3164
3165		/* Out-of-place space has to be available to allow for a reshape unless raid1! */
3166		if (reshape_sectors || rs_is_raid1(rs)) {
3167			/*
3168			  * We can only prepare for a reshape here, because the
3169			  * raid set needs to run to provide the repective reshape
3170			  * check functions via its MD personality instance.
3171			  *
3172			  * So do the reshape check after md_run() succeeded.
3173			  */
3174			r = rs_prepare_reshape(rs);
3175			if (r)
3176				goto bad;
3177
3178			/* Reshaping ain't recovery, so disable recovery */
3179			rs_setup_recovery(rs, MaxSector);
3180		}
3181		rs_set_cur(rs);
3182	} else {
3183size_check:
3184		/* May not set recovery when a device rebuild is requested */
3185		if (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags)) {
3186			clear_bit(RT_FLAG_RS_GROW, &rs->runtime_flags);
3187			set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
3188			rs_setup_recovery(rs, MaxSector);
3189		} else if (test_bit(RT_FLAG_RS_GROW, &rs->runtime_flags)) {
3190			/*
3191			 * Set raid set to current size, i.e. size as of
3192			 * superblocks to grow to larger size in preresume.
3193			 */
3194			r = rs_set_dev_and_array_sectors(rs, sb_array_sectors, false);
3195			if (r)
3196				goto bad;
3197
3198			rs_setup_recovery(rs, rs->md.recovery_cp < rs->md.dev_sectors ? rs->md.recovery_cp : rs->md.dev_sectors);
3199		} else {
3200			/* This is no size change or it is shrinking, update size and record in superblocks */
3201			r = rs_set_dev_and_array_sectors(rs, rs->ti->len, false);
3202			if (r)
3203				goto bad;
3204
3205			if (sb_array_sectors > rs->array_sectors)
3206				set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
3207		}
3208		rs_set_cur(rs);
3209	}
3210
3211	/* If constructor requested it, change data and new_data offsets */
3212	r = rs_adjust_data_offsets(rs);
3213	if (r)
3214		goto bad;
3215
 
 
 
3216	/* Start raid set read-only and assumed clean to change in raid_resume() */
3217	rs->md.ro = 1;
3218	rs->md.in_sync = 1;
3219
3220	/* Keep array frozen */
3221	set_bit(MD_RECOVERY_FROZEN, &rs->md.recovery);
3222
3223	/* Has to be held on running the array */
3224	mddev_lock_nointr(&rs->md);
3225	r = md_run(&rs->md);
3226	rs->md.in_sync = 0; /* Assume already marked dirty */
3227	if (r) {
3228		ti->error = "Failed to run raid array";
3229		mddev_unlock(&rs->md);
3230		goto bad;
3231	}
3232
3233	r = md_start(&rs->md);
3234
3235	if (r) {
3236		ti->error = "Failed to start raid array";
3237		mddev_unlock(&rs->md);
3238		goto bad_md_start;
3239	}
3240
3241	/* If raid4/5/6 journal mode explicitly requested (only possible with journal dev) -> set it */
3242	if (test_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags)) {
3243		r = r5c_journal_mode_set(&rs->md, rs->journal_dev.mode);
3244		if (r) {
3245			ti->error = "Failed to set raid4/5/6 journal mode";
3246			mddev_unlock(&rs->md);
3247			goto bad_journal_mode_set;
3248		}
3249	}
3250
3251	mddev_suspend(&rs->md);
3252	set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags);
3253
3254	/* Try to adjust the raid4/5/6 stripe cache size to the stripe size */
3255	if (rs_is_raid456(rs)) {
3256		r = rs_set_raid456_stripe_cache(rs);
3257		if (r)
3258			goto bad_stripe_cache;
3259	}
3260
3261	/* Now do an early reshape check */
3262	if (test_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags)) {
3263		r = rs_check_reshape(rs);
3264		if (r)
3265			goto bad_check_reshape;
3266
3267		/* Restore new, ctr requested layout to perform check */
3268		rs_config_restore(rs, &rs_layout);
3269
3270		if (rs->md.pers->start_reshape) {
3271			r = rs->md.pers->check_reshape(&rs->md);
3272			if (r) {
3273				ti->error = "Reshape check failed";
3274				goto bad_check_reshape;
3275			}
3276		}
3277	}
3278
3279	/* Disable/enable discard support on raid set. */
3280	configure_discard_support(rs);
3281
3282	mddev_unlock(&rs->md);
3283	return 0;
3284
3285bad_md_start:
3286bad_journal_mode_set:
3287bad_stripe_cache:
3288bad_check_reshape:
3289	md_stop(&rs->md);
3290bad:
3291	raid_set_free(rs);
3292
3293	return r;
3294}
3295
3296static void raid_dtr(struct dm_target *ti)
3297{
3298	struct raid_set *rs = ti->private;
3299
3300	md_stop(&rs->md);
3301	raid_set_free(rs);
3302}
3303
3304static int raid_map(struct dm_target *ti, struct bio *bio)
3305{
3306	struct raid_set *rs = ti->private;
3307	struct mddev *mddev = &rs->md;
3308
3309	/*
3310	 * If we're reshaping to add disk(s)), ti->len and
3311	 * mddev->array_sectors will differ during the process
3312	 * (ti->len > mddev->array_sectors), so we have to requeue
3313	 * bios with addresses > mddev->array_sectors here or
3314	 * there will occur accesses past EOD of the component
3315	 * data images thus erroring the raid set.
3316	 */
3317	if (unlikely(bio_end_sector(bio) > mddev->array_sectors))
3318		return DM_MAPIO_REQUEUE;
3319
3320	md_handle_request(mddev, bio);
3321
3322	return DM_MAPIO_SUBMITTED;
3323}
3324
3325/* Return sync state string for @state */
3326enum sync_state { st_frozen, st_reshape, st_resync, st_check, st_repair, st_recover, st_idle };
3327static const char *sync_str(enum sync_state state)
3328{
3329	/* Has to be in above sync_state order! */
3330	static const char *sync_strs[] = {
3331		"frozen",
3332		"reshape",
3333		"resync",
3334		"check",
3335		"repair",
3336		"recover",
3337		"idle"
3338	};
3339
3340	return __within_range(state, 0, ARRAY_SIZE(sync_strs) - 1) ? sync_strs[state] : "undef";
3341};
3342
3343/* Return enum sync_state for @mddev derived from @recovery flags */
3344static enum sync_state decipher_sync_action(struct mddev *mddev, unsigned long recovery)
3345{
3346	if (test_bit(MD_RECOVERY_FROZEN, &recovery))
3347		return st_frozen;
3348
3349	/* The MD sync thread can be done with io or be interrupted but still be running */
3350	if (!test_bit(MD_RECOVERY_DONE, &recovery) &&
3351	    (test_bit(MD_RECOVERY_RUNNING, &recovery) ||
3352	     (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &recovery)))) {
3353		if (test_bit(MD_RECOVERY_RESHAPE, &recovery))
3354			return st_reshape;
3355
3356		if (test_bit(MD_RECOVERY_SYNC, &recovery)) {
3357			if (!test_bit(MD_RECOVERY_REQUESTED, &recovery))
3358				return st_resync;
3359			if (test_bit(MD_RECOVERY_CHECK, &recovery))
3360				return st_check;
3361			return st_repair;
3362		}
3363
3364		if (test_bit(MD_RECOVERY_RECOVER, &recovery))
3365			return st_recover;
3366
3367		if (mddev->reshape_position != MaxSector)
3368			return st_reshape;
3369	}
3370
3371	return st_idle;
3372}
3373
3374/*
3375 * Return status string for @rdev
3376 *
3377 * Status characters:
3378 *
3379 *  'D' = Dead/Failed raid set component or raid4/5/6 journal device
3380 *  'a' = Alive but not in-sync raid set component _or_ alive raid4/5/6 'write_back' journal device
3381 *  'A' = Alive and in-sync raid set component _or_ alive raid4/5/6 'write_through' journal device
3382 *  '-' = Non-existing device (i.e. uspace passed '- -' into the ctr)
3383 */
3384static const char *__raid_dev_status(struct raid_set *rs, struct md_rdev *rdev)
3385{
3386	if (!rdev->bdev)
3387		return "-";
3388	else if (test_bit(Faulty, &rdev->flags))
3389		return "D";
3390	else if (test_bit(Journal, &rdev->flags))
3391		return (rs->journal_dev.mode == R5C_JOURNAL_MODE_WRITE_THROUGH) ? "A" : "a";
3392	else if (test_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags) ||
3393		 (!test_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags) &&
3394		  !test_bit(In_sync, &rdev->flags)))
3395		return "a";
3396	else
3397		return "A";
3398}
3399
3400/* Helper to return resync/reshape progress for @rs and runtime flags for raid set in sync / resynching */
3401static sector_t rs_get_progress(struct raid_set *rs, unsigned long recovery,
3402				enum sync_state state, sector_t resync_max_sectors)
3403{
3404	sector_t r;
3405	struct mddev *mddev = &rs->md;
3406
3407	clear_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3408	clear_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags);
3409
3410	if (rs_is_raid0(rs)) {
3411		r = resync_max_sectors;
3412		set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3413
3414	} else {
3415		if (state == st_idle && !test_bit(MD_RECOVERY_INTR, &recovery))
3416			r = mddev->recovery_cp;
3417		else
3418			r = mddev->curr_resync_completed;
3419
3420		if (state == st_idle && r >= resync_max_sectors) {
3421			/*
3422			 * Sync complete.
3423			 */
3424			/* In case we have finished recovering, the array is in sync. */
3425			if (test_bit(MD_RECOVERY_RECOVER, &recovery))
3426				set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3427
3428		} else if (state == st_recover)
3429			/*
3430			 * In case we are recovering, the array is not in sync
3431			 * and health chars should show the recovering legs.
3432			 *
3433			 * Already retrieved recovery offset from curr_resync_completed above.
3434			 */
3435			;
3436
3437		else if (state == st_resync || state == st_reshape)
3438			/*
3439			 * If "resync/reshape" is occurring, the raid set
3440			 * is or may be out of sync hence the health
3441			 * characters shall be 'a'.
3442			 */
3443			set_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags);
3444
3445		else if (state == st_check || state == st_repair)
3446			/*
3447			 * If "check" or "repair" is occurring, the raid set has
3448			 * undergone an initial sync and the health characters
3449			 * should not be 'a' anymore.
3450			 */
3451			set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3452
3453		else if (test_bit(MD_RECOVERY_NEEDED, &recovery))
3454			/*
3455			 * We are idle and recovery is needed, prevent 'A' chars race
3456			 * caused by components still set to in-sync by constructor.
3457			 */
3458			set_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags);
3459
3460		else {
3461			/*
3462			 * We are idle and the raid set may be doing an initial
3463			 * sync, or it may be rebuilding individual components.
3464			 * If all the devices are In_sync, then it is the raid set
3465			 * that is being initialized.
3466			 */
3467			struct md_rdev *rdev;
3468
3469			set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3470			rdev_for_each(rdev, mddev)
3471				if (!test_bit(Journal, &rdev->flags) &&
3472				    !test_bit(In_sync, &rdev->flags)) {
3473					clear_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3474					break;
3475				}
3476		}
3477	}
3478
3479	return min(r, resync_max_sectors);
3480}
3481
3482/* Helper to return @dev name or "-" if !@dev */
3483static const char *__get_dev_name(struct dm_dev *dev)
3484{
3485	return dev ? dev->name : "-";
3486}
3487
3488static void raid_status(struct dm_target *ti, status_type_t type,
3489			unsigned int status_flags, char *result, unsigned int maxlen)
3490{
3491	struct raid_set *rs = ti->private;
3492	struct mddev *mddev = &rs->md;
3493	struct r5conf *conf = mddev->private;
3494	int i, max_nr_stripes = conf ? conf->max_nr_stripes : 0;
3495	unsigned long recovery;
3496	unsigned int raid_param_cnt = 1; /* at least 1 for chunksize */
3497	unsigned int sz = 0;
3498	unsigned int rebuild_writemostly_count = 0;
3499	sector_t progress, resync_max_sectors, resync_mismatches;
3500	enum sync_state state;
3501	struct raid_type *rt;
3502
3503	switch (type) {
3504	case STATUSTYPE_INFO:
3505		/* *Should* always succeed */
3506		rt = get_raid_type_by_ll(mddev->new_level, mddev->new_layout);
3507		if (!rt)
3508			return;
3509
3510		DMEMIT("%s %d ", rt->name, mddev->raid_disks);
3511
3512		/* Access most recent mddev properties for status output */
3513		smp_rmb();
3514		/* Get sensible max sectors even if raid set not yet started */
3515		resync_max_sectors = test_bit(RT_FLAG_RS_PRERESUMED, &rs->runtime_flags) ?
3516				      mddev->resync_max_sectors : mddev->dev_sectors;
3517		recovery = rs->md.recovery;
3518		state = decipher_sync_action(mddev, recovery);
3519		progress = rs_get_progress(rs, recovery, state, resync_max_sectors);
3520		resync_mismatches = (mddev->last_sync_action && !strcasecmp(mddev->last_sync_action, "check")) ?
3521				    atomic64_read(&mddev->resync_mismatches) : 0;
3522
3523		/* HM FIXME: do we want another state char for raid0? It shows 'D'/'A'/'-' now */
3524		for (i = 0; i < rs->raid_disks; i++)
3525			DMEMIT(__raid_dev_status(rs, &rs->dev[i].rdev));
3526
3527		/*
3528		 * In-sync/Reshape ratio:
3529		 *  The in-sync ratio shows the progress of:
3530		 *   - Initializing the raid set
3531		 *   - Rebuilding a subset of devices of the raid set
3532		 *  The user can distinguish between the two by referring
3533		 *  to the status characters.
3534		 *
3535		 *  The reshape ratio shows the progress of
3536		 *  changing the raid layout or the number of
3537		 *  disks of a raid set
3538		 */
3539		DMEMIT(" %llu/%llu", (unsigned long long) progress,
3540				     (unsigned long long) resync_max_sectors);
3541
3542		/*
3543		 * v1.5.0+:
3544		 *
3545		 * Sync action:
3546		 *   See Documentation/admin-guide/device-mapper/dm-raid.rst for
3547		 *   information on each of these states.
3548		 */
3549		DMEMIT(" %s", sync_str(state));
3550
3551		/*
3552		 * v1.5.0+:
3553		 *
3554		 * resync_mismatches/mismatch_cnt
3555		 *   This field shows the number of discrepancies found when
3556		 *   performing a "check" of the raid set.
3557		 */
3558		DMEMIT(" %llu", (unsigned long long) resync_mismatches);
3559
3560		/*
3561		 * v1.9.0+:
3562		 *
3563		 * data_offset (needed for out of space reshaping)
3564		 *   This field shows the data offset into the data
3565		 *   image LV where the first stripes data starts.
3566		 *
3567		 * We keep data_offset equal on all raid disks of the set,
3568		 * so retrieving it from the first raid disk is sufficient.
3569		 */
3570		DMEMIT(" %llu", (unsigned long long) rs->dev[0].rdev.data_offset);
3571
3572		/*
3573		 * v1.10.0+:
3574		 */
3575		DMEMIT(" %s", test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags) ?
3576			      __raid_dev_status(rs, &rs->journal_dev.rdev) : "-");
3577		break;
3578
3579	case STATUSTYPE_TABLE:
3580		/* Report the table line string you would use to construct this raid set */
3581
3582		/*
3583		 * Count any rebuild or writemostly argument pairs and subtract the
3584		 * hweight count being added below of any rebuild and writemostly ctr flags.
3585		 */
3586		for (i = 0; i < rs->raid_disks; i++) {
3587			rebuild_writemostly_count += (test_bit(i, (void *) rs->rebuild_disks) ? 2 : 0) +
3588						     (test_bit(WriteMostly, &rs->dev[i].rdev.flags) ? 2 : 0);
3589		}
3590		rebuild_writemostly_count -= (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags) ? 2 : 0) +
3591					     (test_bit(__CTR_FLAG_WRITE_MOSTLY, &rs->ctr_flags) ? 2 : 0);
3592		/* Calculate raid parameter count based on ^ rebuild/writemostly argument counts and ctr flags set. */
3593		raid_param_cnt += rebuild_writemostly_count +
3594				  hweight32(rs->ctr_flags & CTR_FLAG_OPTIONS_NO_ARGS) +
3595				  hweight32(rs->ctr_flags & CTR_FLAG_OPTIONS_ONE_ARG) * 2;
3596		/* Emit table line */
3597		/* This has to be in the documented order for userspace! */
3598		DMEMIT("%s %u %u", rs->raid_type->name, raid_param_cnt, mddev->new_chunk_sectors);
3599		if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags))
3600			DMEMIT(" %s", dm_raid_arg_name_by_flag(CTR_FLAG_SYNC));
3601		if (test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))
3602			DMEMIT(" %s", dm_raid_arg_name_by_flag(CTR_FLAG_NOSYNC));
3603		if (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags))
3604			for (i = 0; i < rs->raid_disks; i++)
3605				if (test_bit(i, (void *) rs->rebuild_disks))
3606					DMEMIT(" %s %u", dm_raid_arg_name_by_flag(CTR_FLAG_REBUILD), i);
3607		if (test_bit(__CTR_FLAG_DAEMON_SLEEP, &rs->ctr_flags))
3608			DMEMIT(" %s %lu", dm_raid_arg_name_by_flag(CTR_FLAG_DAEMON_SLEEP),
3609					  mddev->bitmap_info.daemon_sleep);
3610		if (test_bit(__CTR_FLAG_MIN_RECOVERY_RATE, &rs->ctr_flags))
3611			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_MIN_RECOVERY_RATE),
3612					 mddev->sync_speed_min);
3613		if (test_bit(__CTR_FLAG_MAX_RECOVERY_RATE, &rs->ctr_flags))
3614			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_MAX_RECOVERY_RATE),
3615					 mddev->sync_speed_max);
3616		if (test_bit(__CTR_FLAG_WRITE_MOSTLY, &rs->ctr_flags))
3617			for (i = 0; i < rs->raid_disks; i++)
3618				if (test_bit(WriteMostly, &rs->dev[i].rdev.flags))
3619					DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_WRITE_MOSTLY),
3620					       rs->dev[i].rdev.raid_disk);
3621		if (test_bit(__CTR_FLAG_MAX_WRITE_BEHIND, &rs->ctr_flags))
3622			DMEMIT(" %s %lu", dm_raid_arg_name_by_flag(CTR_FLAG_MAX_WRITE_BEHIND),
3623					  mddev->bitmap_info.max_write_behind);
3624		if (test_bit(__CTR_FLAG_STRIPE_CACHE, &rs->ctr_flags))
3625			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_STRIPE_CACHE),
3626					 max_nr_stripes);
3627		if (test_bit(__CTR_FLAG_REGION_SIZE, &rs->ctr_flags))
3628			DMEMIT(" %s %llu", dm_raid_arg_name_by_flag(CTR_FLAG_REGION_SIZE),
3629					   (unsigned long long) to_sector(mddev->bitmap_info.chunksize));
3630		if (test_bit(__CTR_FLAG_RAID10_COPIES, &rs->ctr_flags))
3631			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_COPIES),
3632					 raid10_md_layout_to_copies(mddev->layout));
3633		if (test_bit(__CTR_FLAG_RAID10_FORMAT, &rs->ctr_flags))
3634			DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_FORMAT),
3635					 raid10_md_layout_to_format(mddev->layout));
3636		if (test_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags))
3637			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_DELTA_DISKS),
3638					 max(rs->delta_disks, mddev->delta_disks));
3639		if (test_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags))
3640			DMEMIT(" %s %llu", dm_raid_arg_name_by_flag(CTR_FLAG_DATA_OFFSET),
3641					   (unsigned long long) rs->data_offset);
3642		if (test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags))
3643			DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_DEV),
3644					__get_dev_name(rs->journal_dev.dev));
3645		if (test_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags))
3646			DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_MODE),
3647					 md_journal_mode_to_dm_raid(rs->journal_dev.mode));
3648		DMEMIT(" %d", rs->raid_disks);
3649		for (i = 0; i < rs->raid_disks; i++)
3650			DMEMIT(" %s %s", __get_dev_name(rs->dev[i].meta_dev),
3651					 __get_dev_name(rs->dev[i].data_dev));
3652	}
3653}
3654
3655static int raid_message(struct dm_target *ti, unsigned int argc, char **argv,
3656			char *result, unsigned maxlen)
3657{
3658	struct raid_set *rs = ti->private;
3659	struct mddev *mddev = &rs->md;
3660
3661	if (!mddev->pers || !mddev->pers->sync_request)
3662		return -EINVAL;
3663
3664	if (!strcasecmp(argv[0], "frozen"))
3665		set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3666	else
3667		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3668
3669	if (!strcasecmp(argv[0], "idle") || !strcasecmp(argv[0], "frozen")) {
3670		if (mddev->sync_thread) {
3671			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
3672			md_reap_sync_thread(mddev);
3673		}
3674	} else if (decipher_sync_action(mddev, mddev->recovery) != st_idle)
3675		return -EBUSY;
3676	else if (!strcasecmp(argv[0], "resync"))
3677		; /* MD_RECOVERY_NEEDED set below */
3678	else if (!strcasecmp(argv[0], "recover"))
3679		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
3680	else {
3681		if (!strcasecmp(argv[0], "check")) {
3682			set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
3683			set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
3684			set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3685		} else if (!strcasecmp(argv[0], "repair")) {
3686			set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
3687			set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3688		} else
3689			return -EINVAL;
3690	}
3691	if (mddev->ro == 2) {
3692		/* A write to sync_action is enough to justify
3693		 * canceling read-auto mode
3694		 */
3695		mddev->ro = 0;
3696		if (!mddev->suspended && mddev->sync_thread)
3697			md_wakeup_thread(mddev->sync_thread);
3698	}
3699	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3700	if (!mddev->suspended && mddev->thread)
3701		md_wakeup_thread(mddev->thread);
3702
3703	return 0;
3704}
3705
3706static int raid_iterate_devices(struct dm_target *ti,
3707				iterate_devices_callout_fn fn, void *data)
3708{
3709	struct raid_set *rs = ti->private;
3710	unsigned int i;
3711	int r = 0;
3712
3713	for (i = 0; !r && i < rs->md.raid_disks; i++)
3714		if (rs->dev[i].data_dev)
3715			r = fn(ti,
3716				 rs->dev[i].data_dev,
3717				 0, /* No offset on data devs */
3718				 rs->md.dev_sectors,
3719				 data);
3720
3721	return r;
3722}
3723
3724static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
3725{
3726	struct raid_set *rs = ti->private;
3727	unsigned int chunk_size_bytes = to_bytes(rs->md.chunk_sectors);
3728
3729	blk_limits_io_min(limits, chunk_size_bytes);
3730	blk_limits_io_opt(limits, chunk_size_bytes * mddev_data_stripes(rs));
3731
3732	/*
3733	 * RAID1 and RAID10 personalities require bio splitting,
3734	 * RAID0/4/5/6 don't and process large discard bios properly.
3735	 */
3736	if (rs_is_raid1(rs) || rs_is_raid10(rs)) {
3737		limits->discard_granularity = chunk_size_bytes;
3738		limits->max_discard_sectors = rs->md.chunk_sectors;
3739	}
3740}
3741
3742static void raid_postsuspend(struct dm_target *ti)
3743{
3744	struct raid_set *rs = ti->private;
3745
3746	if (!test_and_set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) {
3747		/* Writes have to be stopped before suspending to avoid deadlocks. */
3748		if (!test_bit(MD_RECOVERY_FROZEN, &rs->md.recovery))
3749			md_stop_writes(&rs->md);
3750
3751		mddev_lock_nointr(&rs->md);
3752		mddev_suspend(&rs->md);
3753		mddev_unlock(&rs->md);
3754	}
3755}
3756
3757static void attempt_restore_of_faulty_devices(struct raid_set *rs)
3758{
3759	int i;
3760	uint64_t cleared_failed_devices[DISKS_ARRAY_ELEMS];
3761	unsigned long flags;
3762	bool cleared = false;
3763	struct dm_raid_superblock *sb;
3764	struct mddev *mddev = &rs->md;
3765	struct md_rdev *r;
3766
3767	/* RAID personalities have to provide hot add/remove methods or we need to bail out. */
3768	if (!mddev->pers || !mddev->pers->hot_add_disk || !mddev->pers->hot_remove_disk)
3769		return;
3770
3771	memset(cleared_failed_devices, 0, sizeof(cleared_failed_devices));
3772
3773	for (i = 0; i < mddev->raid_disks; i++) {
3774		r = &rs->dev[i].rdev;
3775		/* HM FIXME: enhance journal device recovery processing */
3776		if (test_bit(Journal, &r->flags))
3777			continue;
3778
3779		if (test_bit(Faulty, &r->flags) &&
3780		    r->meta_bdev && !read_disk_sb(r, r->sb_size, true)) {
3781			DMINFO("Faulty %s device #%d has readable super block."
3782			       "  Attempting to revive it.",
3783			       rs->raid_type->name, i);
3784
3785			/*
3786			 * Faulty bit may be set, but sometimes the array can
3787			 * be suspended before the personalities can respond
3788			 * by removing the device from the array (i.e. calling
3789			 * 'hot_remove_disk').	If they haven't yet removed
3790			 * the failed device, its 'raid_disk' number will be
3791			 * '>= 0' - meaning we must call this function
3792			 * ourselves.
3793			 */
3794			flags = r->flags;
3795			clear_bit(In_sync, &r->flags); /* Mandatory for hot remove. */
3796			if (r->raid_disk >= 0) {
3797				if (mddev->pers->hot_remove_disk(mddev, r)) {
3798					/* Failed to revive this device, try next */
3799					r->flags = flags;
3800					continue;
3801				}
3802			} else
3803				r->raid_disk = r->saved_raid_disk = i;
3804
3805			clear_bit(Faulty, &r->flags);
3806			clear_bit(WriteErrorSeen, &r->flags);
3807
3808			if (mddev->pers->hot_add_disk(mddev, r)) {
3809				/* Failed to revive this device, try next */
3810				r->raid_disk = r->saved_raid_disk = -1;
3811				r->flags = flags;
3812			} else {
3813				clear_bit(In_sync, &r->flags);
3814				r->recovery_offset = 0;
3815				set_bit(i, (void *) cleared_failed_devices);
3816				cleared = true;
3817			}
3818		}
3819	}
3820
3821	/* If any failed devices could be cleared, update all sbs failed_devices bits */
3822	if (cleared) {
3823		uint64_t failed_devices[DISKS_ARRAY_ELEMS];
3824
3825		rdev_for_each(r, &rs->md) {
3826			if (test_bit(Journal, &r->flags))
3827				continue;
3828
3829			sb = page_address(r->sb_page);
3830			sb_retrieve_failed_devices(sb, failed_devices);
3831
3832			for (i = 0; i < DISKS_ARRAY_ELEMS; i++)
3833				failed_devices[i] &= ~cleared_failed_devices[i];
3834
3835			sb_update_failed_devices(sb, failed_devices);
3836		}
3837	}
3838}
3839
3840static int __load_dirty_region_bitmap(struct raid_set *rs)
3841{
3842	int r = 0;
3843
3844	/* Try loading the bitmap unless "raid0", which does not have one */
3845	if (!rs_is_raid0(rs) &&
3846	    !test_and_set_bit(RT_FLAG_RS_BITMAP_LOADED, &rs->runtime_flags)) {
3847		r = md_bitmap_load(&rs->md);
3848		if (r)
3849			DMERR("Failed to load bitmap");
3850	}
3851
3852	return r;
3853}
3854
3855/* Enforce updating all superblocks */
3856static void rs_update_sbs(struct raid_set *rs)
3857{
3858	struct mddev *mddev = &rs->md;
3859	int ro = mddev->ro;
3860
3861	set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
3862	mddev->ro = 0;
3863	md_update_sb(mddev, 1);
3864	mddev->ro = ro;
3865}
3866
3867/*
3868 * Reshape changes raid algorithm of @rs to new one within personality
3869 * (e.g. raid6_zr -> raid6_nc), changes stripe size, adds/removes
3870 * disks from a raid set thus growing/shrinking it or resizes the set
3871 *
3872 * Call mddev_lock_nointr() before!
3873 */
3874static int rs_start_reshape(struct raid_set *rs)
3875{
3876	int r;
3877	struct mddev *mddev = &rs->md;
3878	struct md_personality *pers = mddev->pers;
3879
3880	/* Don't allow the sync thread to work until the table gets reloaded. */
3881	set_bit(MD_RECOVERY_WAIT, &mddev->recovery);
3882
3883	r = rs_setup_reshape(rs);
3884	if (r)
3885		return r;
3886
3887	/*
3888	 * Check any reshape constraints enforced by the personalility
3889	 *
3890	 * May as well already kick the reshape off so that * pers->start_reshape() becomes optional.
3891	 */
3892	r = pers->check_reshape(mddev);
3893	if (r) {
3894		rs->ti->error = "pers->check_reshape() failed";
3895		return r;
3896	}
3897
3898	/*
3899	 * Personality may not provide start reshape method in which
3900	 * case check_reshape above has already covered everything
3901	 */
3902	if (pers->start_reshape) {
3903		r = pers->start_reshape(mddev);
3904		if (r) {
3905			rs->ti->error = "pers->start_reshape() failed";
3906			return r;
3907		}
3908	}
3909
3910	/*
3911	 * Now reshape got set up, update superblocks to
3912	 * reflect the fact so that a table reload will
3913	 * access proper superblock content in the ctr.
3914	 */
3915	rs_update_sbs(rs);
3916
3917	return 0;
3918}
3919
3920static int raid_preresume(struct dm_target *ti)
3921{
3922	int r;
3923	struct raid_set *rs = ti->private;
3924	struct mddev *mddev = &rs->md;
3925
3926	/* This is a resume after a suspend of the set -> it's already started. */
3927	if (test_and_set_bit(RT_FLAG_RS_PRERESUMED, &rs->runtime_flags))
3928		return 0;
3929
3930	/*
3931	 * The superblocks need to be updated on disk if the
3932	 * array is new or new devices got added (thus zeroed
3933	 * out by userspace) or __load_dirty_region_bitmap
3934	 * will overwrite them in core with old data or fail.
3935	 */
3936	if (test_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags))
3937		rs_update_sbs(rs);
3938
3939	/* Load the bitmap from disk unless raid0 */
3940	r = __load_dirty_region_bitmap(rs);
3941	if (r)
3942		return r;
3943
3944	/* We are extending the raid set size, adjust mddev/md_rdev sizes and set capacity. */
3945	if (test_bit(RT_FLAG_RS_GROW, &rs->runtime_flags)) {
3946		mddev->array_sectors = rs->array_sectors;
3947		mddev->dev_sectors = rs->dev_sectors;
3948		rs_set_rdev_sectors(rs);
3949		rs_set_capacity(rs);
3950	}
3951
3952	/* Resize bitmap to adjust to changed region size (aka MD bitmap chunksize) or grown device size */
3953        if (test_bit(RT_FLAG_RS_BITMAP_LOADED, &rs->runtime_flags) && mddev->bitmap &&
3954	    (test_bit(RT_FLAG_RS_GROW, &rs->runtime_flags) ||
3955	     (rs->requested_bitmap_chunk_sectors &&
3956	       mddev->bitmap_info.chunksize != to_bytes(rs->requested_bitmap_chunk_sectors)))) {
3957		int chunksize = to_bytes(rs->requested_bitmap_chunk_sectors) ?: mddev->bitmap_info.chunksize;
3958
3959		r = md_bitmap_resize(mddev->bitmap, mddev->dev_sectors, chunksize, 0);
3960		if (r)
3961			DMERR("Failed to resize bitmap");
3962	}
3963
3964	/* Check for any resize/reshape on @rs and adjust/initiate */
3965	/* Be prepared for mddev_resume() in raid_resume() */
3966	set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3967	if (mddev->recovery_cp && mddev->recovery_cp < MaxSector) {
3968		set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
3969		mddev->resync_min = mddev->recovery_cp;
3970		if (test_bit(RT_FLAG_RS_GROW, &rs->runtime_flags))
3971			mddev->resync_max_sectors = mddev->dev_sectors;
3972	}
3973
3974	/* Check for any reshape request unless new raid set */
3975	if (test_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags)) {
3976		/* Initiate a reshape. */
3977		rs_set_rdev_sectors(rs);
3978		mddev_lock_nointr(mddev);
3979		r = rs_start_reshape(rs);
3980		mddev_unlock(mddev);
3981		if (r)
3982			DMWARN("Failed to check/start reshape, continuing without change");
3983		r = 0;
3984	}
3985
3986	return r;
3987}
3988
3989static void raid_resume(struct dm_target *ti)
3990{
3991	struct raid_set *rs = ti->private;
3992	struct mddev *mddev = &rs->md;
3993
3994	if (test_and_set_bit(RT_FLAG_RS_RESUMED, &rs->runtime_flags)) {
3995		/*
3996		 * A secondary resume while the device is active.
3997		 * Take this opportunity to check whether any failed
3998		 * devices are reachable again.
3999		 */
4000		attempt_restore_of_faulty_devices(rs);
4001	}
4002
4003	if (test_and_clear_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) {
4004		/* Only reduce raid set size before running a disk removing reshape. */
4005		if (mddev->delta_disks < 0)
4006			rs_set_capacity(rs);
4007
4008		mddev_lock_nointr(mddev);
4009		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4010		mddev->ro = 0;
4011		mddev->in_sync = 0;
4012		mddev_resume(mddev);
4013		mddev_unlock(mddev);
4014	}
4015}
4016
4017static struct target_type raid_target = {
4018	.name = "raid",
4019	.version = {1, 15, 1},
4020	.module = THIS_MODULE,
4021	.ctr = raid_ctr,
4022	.dtr = raid_dtr,
4023	.map = raid_map,
4024	.status = raid_status,
4025	.message = raid_message,
4026	.iterate_devices = raid_iterate_devices,
4027	.io_hints = raid_io_hints,
4028	.postsuspend = raid_postsuspend,
4029	.preresume = raid_preresume,
4030	.resume = raid_resume,
4031};
4032
4033static int __init dm_raid_init(void)
4034{
4035	DMINFO("Loading target version %u.%u.%u",
4036	       raid_target.version[0],
4037	       raid_target.version[1],
4038	       raid_target.version[2]);
4039	return dm_register_target(&raid_target);
4040}
4041
4042static void __exit dm_raid_exit(void)
4043{
4044	dm_unregister_target(&raid_target);
4045}
4046
4047module_init(dm_raid_init);
4048module_exit(dm_raid_exit);
4049
4050module_param(devices_handle_discard_safely, bool, 0644);
4051MODULE_PARM_DESC(devices_handle_discard_safely,
4052		 "Set to Y if all devices in each array reliably return zeroes on reads from discarded regions");
4053
4054MODULE_DESCRIPTION(DM_NAME " raid0/1/10/4/5/6 target");
4055MODULE_ALIAS("dm-raid0");
4056MODULE_ALIAS("dm-raid1");
4057MODULE_ALIAS("dm-raid10");
4058MODULE_ALIAS("dm-raid4");
4059MODULE_ALIAS("dm-raid5");
4060MODULE_ALIAS("dm-raid6");
4061MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>");
4062MODULE_AUTHOR("Heinz Mauelshagen <dm-devel@redhat.com>");
4063MODULE_LICENSE("GPL");
v5.14.15
   1/*
   2 * Copyright (C) 2010-2011 Neil Brown
   3 * Copyright (C) 2010-2018 Red Hat, Inc. All rights reserved.
   4 *
   5 * This file is released under the GPL.
   6 */
   7
   8#include <linux/slab.h>
   9#include <linux/module.h>
  10
  11#include "md.h"
  12#include "raid1.h"
  13#include "raid5.h"
  14#include "raid10.h"
  15#include "md-bitmap.h"
  16
  17#include <linux/device-mapper.h>
  18
  19#define DM_MSG_PREFIX "raid"
  20#define	MAX_RAID_DEVICES	253 /* md-raid kernel limit */
  21
  22/*
  23 * Minimum sectors of free reshape space per raid device
  24 */
  25#define	MIN_FREE_RESHAPE_SPACE to_sector(4*4096)
  26
  27/*
  28 * Minimum journal space 4 MiB in sectors.
  29 */
  30#define	MIN_RAID456_JOURNAL_SPACE (4*2048)
  31
  32static bool devices_handle_discard_safely = false;
  33
  34/*
  35 * The following flags are used by dm-raid.c to set up the array state.
  36 * They must be cleared before md_run is called.
  37 */
  38#define FirstUse 10		/* rdev flag */
  39
  40struct raid_dev {
  41	/*
  42	 * Two DM devices, one to hold metadata and one to hold the
  43	 * actual data/parity.	The reason for this is to not confuse
  44	 * ti->len and give more flexibility in altering size and
  45	 * characteristics.
  46	 *
  47	 * While it is possible for this device to be associated
  48	 * with a different physical device than the data_dev, it
  49	 * is intended for it to be the same.
  50	 *    |--------- Physical Device ---------|
  51	 *    |- meta_dev -|------ data_dev ------|
  52	 */
  53	struct dm_dev *meta_dev;
  54	struct dm_dev *data_dev;
  55	struct md_rdev rdev;
  56};
  57
  58/*
  59 * Bits for establishing rs->ctr_flags
  60 *
  61 * 1 = no flag value
  62 * 2 = flag with value
  63 */
  64#define __CTR_FLAG_SYNC			0  /* 1 */ /* Not with raid0! */
  65#define __CTR_FLAG_NOSYNC		1  /* 1 */ /* Not with raid0! */
  66#define __CTR_FLAG_REBUILD		2  /* 2 */ /* Not with raid0! */
  67#define __CTR_FLAG_DAEMON_SLEEP		3  /* 2 */ /* Not with raid0! */
  68#define __CTR_FLAG_MIN_RECOVERY_RATE	4  /* 2 */ /* Not with raid0! */
  69#define __CTR_FLAG_MAX_RECOVERY_RATE	5  /* 2 */ /* Not with raid0! */
  70#define __CTR_FLAG_MAX_WRITE_BEHIND	6  /* 2 */ /* Only with raid1! */
  71#define __CTR_FLAG_WRITE_MOSTLY		7  /* 2 */ /* Only with raid1! */
  72#define __CTR_FLAG_STRIPE_CACHE		8  /* 2 */ /* Only with raid4/5/6! */
  73#define __CTR_FLAG_REGION_SIZE		9  /* 2 */ /* Not with raid0! */
  74#define __CTR_FLAG_RAID10_COPIES	10 /* 2 */ /* Only with raid10 */
  75#define __CTR_FLAG_RAID10_FORMAT	11 /* 2 */ /* Only with raid10 */
  76/* New for v1.9.0 */
  77#define __CTR_FLAG_DELTA_DISKS		12 /* 2 */ /* Only with reshapable raid1/4/5/6/10! */
  78#define __CTR_FLAG_DATA_OFFSET		13 /* 2 */ /* Only with reshapable raid4/5/6/10! */
  79#define __CTR_FLAG_RAID10_USE_NEAR_SETS 14 /* 2 */ /* Only with raid10! */
  80
  81/* New for v1.10.0 */
  82#define __CTR_FLAG_JOURNAL_DEV		15 /* 2 */ /* Only with raid4/5/6 (journal device)! */
  83
  84/* New for v1.11.1 */
  85#define __CTR_FLAG_JOURNAL_MODE		16 /* 2 */ /* Only with raid4/5/6 (journal mode)! */
  86
  87/*
  88 * Flags for rs->ctr_flags field.
  89 */
  90#define CTR_FLAG_SYNC			(1 << __CTR_FLAG_SYNC)
  91#define CTR_FLAG_NOSYNC			(1 << __CTR_FLAG_NOSYNC)
  92#define CTR_FLAG_REBUILD		(1 << __CTR_FLAG_REBUILD)
  93#define CTR_FLAG_DAEMON_SLEEP		(1 << __CTR_FLAG_DAEMON_SLEEP)
  94#define CTR_FLAG_MIN_RECOVERY_RATE	(1 << __CTR_FLAG_MIN_RECOVERY_RATE)
  95#define CTR_FLAG_MAX_RECOVERY_RATE	(1 << __CTR_FLAG_MAX_RECOVERY_RATE)
  96#define CTR_FLAG_MAX_WRITE_BEHIND	(1 << __CTR_FLAG_MAX_WRITE_BEHIND)
  97#define CTR_FLAG_WRITE_MOSTLY		(1 << __CTR_FLAG_WRITE_MOSTLY)
  98#define CTR_FLAG_STRIPE_CACHE		(1 << __CTR_FLAG_STRIPE_CACHE)
  99#define CTR_FLAG_REGION_SIZE		(1 << __CTR_FLAG_REGION_SIZE)
 100#define CTR_FLAG_RAID10_COPIES		(1 << __CTR_FLAG_RAID10_COPIES)
 101#define CTR_FLAG_RAID10_FORMAT		(1 << __CTR_FLAG_RAID10_FORMAT)
 102#define CTR_FLAG_DELTA_DISKS		(1 << __CTR_FLAG_DELTA_DISKS)
 103#define CTR_FLAG_DATA_OFFSET		(1 << __CTR_FLAG_DATA_OFFSET)
 104#define CTR_FLAG_RAID10_USE_NEAR_SETS	(1 << __CTR_FLAG_RAID10_USE_NEAR_SETS)
 105#define CTR_FLAG_JOURNAL_DEV		(1 << __CTR_FLAG_JOURNAL_DEV)
 106#define CTR_FLAG_JOURNAL_MODE		(1 << __CTR_FLAG_JOURNAL_MODE)
 107
 108/*
 109 * Definitions of various constructor flags to
 110 * be used in checks of valid / invalid flags
 111 * per raid level.
 112 */
 113/* Define all any sync flags */
 114#define	CTR_FLAGS_ANY_SYNC		(CTR_FLAG_SYNC | CTR_FLAG_NOSYNC)
 115
 116/* Define flags for options without argument (e.g. 'nosync') */
 117#define	CTR_FLAG_OPTIONS_NO_ARGS	(CTR_FLAGS_ANY_SYNC | \
 118					 CTR_FLAG_RAID10_USE_NEAR_SETS)
 119
 120/* Define flags for options with one argument (e.g. 'delta_disks +2') */
 121#define CTR_FLAG_OPTIONS_ONE_ARG (CTR_FLAG_REBUILD | \
 122				  CTR_FLAG_WRITE_MOSTLY | \
 123				  CTR_FLAG_DAEMON_SLEEP | \
 124				  CTR_FLAG_MIN_RECOVERY_RATE | \
 125				  CTR_FLAG_MAX_RECOVERY_RATE | \
 126				  CTR_FLAG_MAX_WRITE_BEHIND | \
 127				  CTR_FLAG_STRIPE_CACHE | \
 128				  CTR_FLAG_REGION_SIZE | \
 129				  CTR_FLAG_RAID10_COPIES | \
 130				  CTR_FLAG_RAID10_FORMAT | \
 131				  CTR_FLAG_DELTA_DISKS | \
 132				  CTR_FLAG_DATA_OFFSET | \
 133				  CTR_FLAG_JOURNAL_DEV | \
 134				  CTR_FLAG_JOURNAL_MODE)
 135
 136/* Valid options definitions per raid level... */
 137
 138/* "raid0" does only accept data offset */
 139#define RAID0_VALID_FLAGS	(CTR_FLAG_DATA_OFFSET)
 140
 141/* "raid1" does not accept stripe cache, data offset, delta_disks or any raid10 options */
 142#define RAID1_VALID_FLAGS	(CTR_FLAGS_ANY_SYNC | \
 143				 CTR_FLAG_REBUILD | \
 144				 CTR_FLAG_WRITE_MOSTLY | \
 145				 CTR_FLAG_DAEMON_SLEEP | \
 146				 CTR_FLAG_MIN_RECOVERY_RATE | \
 147				 CTR_FLAG_MAX_RECOVERY_RATE | \
 148				 CTR_FLAG_MAX_WRITE_BEHIND | \
 149				 CTR_FLAG_REGION_SIZE | \
 150				 CTR_FLAG_DELTA_DISKS | \
 151				 CTR_FLAG_DATA_OFFSET)
 152
 153/* "raid10" does not accept any raid1 or stripe cache options */
 154#define RAID10_VALID_FLAGS	(CTR_FLAGS_ANY_SYNC | \
 155				 CTR_FLAG_REBUILD | \
 156				 CTR_FLAG_DAEMON_SLEEP | \
 157				 CTR_FLAG_MIN_RECOVERY_RATE | \
 158				 CTR_FLAG_MAX_RECOVERY_RATE | \
 159				 CTR_FLAG_REGION_SIZE | \
 160				 CTR_FLAG_RAID10_COPIES | \
 161				 CTR_FLAG_RAID10_FORMAT | \
 162				 CTR_FLAG_DELTA_DISKS | \
 163				 CTR_FLAG_DATA_OFFSET | \
 164				 CTR_FLAG_RAID10_USE_NEAR_SETS)
 165
 166/*
 167 * "raid4/5/6" do not accept any raid1 or raid10 specific options
 168 *
 169 * "raid6" does not accept "nosync", because it is not guaranteed
 170 * that both parity and q-syndrome are being written properly with
 171 * any writes
 172 */
 173#define RAID45_VALID_FLAGS	(CTR_FLAGS_ANY_SYNC | \
 174				 CTR_FLAG_REBUILD | \
 175				 CTR_FLAG_DAEMON_SLEEP | \
 176				 CTR_FLAG_MIN_RECOVERY_RATE | \
 177				 CTR_FLAG_MAX_RECOVERY_RATE | \
 178				 CTR_FLAG_STRIPE_CACHE | \
 179				 CTR_FLAG_REGION_SIZE | \
 180				 CTR_FLAG_DELTA_DISKS | \
 181				 CTR_FLAG_DATA_OFFSET | \
 182				 CTR_FLAG_JOURNAL_DEV | \
 183				 CTR_FLAG_JOURNAL_MODE)
 184
 185#define RAID6_VALID_FLAGS	(CTR_FLAG_SYNC | \
 186				 CTR_FLAG_REBUILD | \
 187				 CTR_FLAG_DAEMON_SLEEP | \
 188				 CTR_FLAG_MIN_RECOVERY_RATE | \
 189				 CTR_FLAG_MAX_RECOVERY_RATE | \
 190				 CTR_FLAG_STRIPE_CACHE | \
 191				 CTR_FLAG_REGION_SIZE | \
 192				 CTR_FLAG_DELTA_DISKS | \
 193				 CTR_FLAG_DATA_OFFSET | \
 194				 CTR_FLAG_JOURNAL_DEV | \
 195				 CTR_FLAG_JOURNAL_MODE)
 196/* ...valid options definitions per raid level */
 197
 198/*
 199 * Flags for rs->runtime_flags field
 200 * (RT_FLAG prefix meaning "runtime flag")
 201 *
 202 * These are all internal and used to define runtime state,
 203 * e.g. to prevent another resume from preresume processing
 204 * the raid set all over again.
 205 */
 206#define RT_FLAG_RS_PRERESUMED		0
 207#define RT_FLAG_RS_RESUMED		1
 208#define RT_FLAG_RS_BITMAP_LOADED	2
 209#define RT_FLAG_UPDATE_SBS		3
 210#define RT_FLAG_RESHAPE_RS		4
 211#define RT_FLAG_RS_SUSPENDED		5
 212#define RT_FLAG_RS_IN_SYNC		6
 213#define RT_FLAG_RS_RESYNCING		7
 214#define RT_FLAG_RS_GROW			8
 215
 216/* Array elements of 64 bit needed for rebuild/failed disk bits */
 217#define DISKS_ARRAY_ELEMS ((MAX_RAID_DEVICES + (sizeof(uint64_t) * 8 - 1)) / sizeof(uint64_t) / 8)
 218
 219/*
 220 * raid set level, layout and chunk sectors backup/restore
 221 */
 222struct rs_layout {
 223	int new_level;
 224	int new_layout;
 225	int new_chunk_sectors;
 226};
 227
 228struct raid_set {
 229	struct dm_target *ti;
 230
 231	uint32_t stripe_cache_entries;
 232	unsigned long ctr_flags;
 233	unsigned long runtime_flags;
 234
 235	uint64_t rebuild_disks[DISKS_ARRAY_ELEMS];
 236
 237	int raid_disks;
 238	int delta_disks;
 239	int data_offset;
 240	int raid10_copies;
 241	int requested_bitmap_chunk_sectors;
 242
 243	struct mddev md;
 244	struct raid_type *raid_type;
 245
 246	sector_t array_sectors;
 247	sector_t dev_sectors;
 248
 249	/* Optional raid4/5/6 journal device */
 250	struct journal_dev {
 251		struct dm_dev *dev;
 252		struct md_rdev rdev;
 253		int mode;
 254	} journal_dev;
 255
 256	struct raid_dev dev[];
 257};
 258
 259static void rs_config_backup(struct raid_set *rs, struct rs_layout *l)
 260{
 261	struct mddev *mddev = &rs->md;
 262
 263	l->new_level = mddev->new_level;
 264	l->new_layout = mddev->new_layout;
 265	l->new_chunk_sectors = mddev->new_chunk_sectors;
 266}
 267
 268static void rs_config_restore(struct raid_set *rs, struct rs_layout *l)
 269{
 270	struct mddev *mddev = &rs->md;
 271
 272	mddev->new_level = l->new_level;
 273	mddev->new_layout = l->new_layout;
 274	mddev->new_chunk_sectors = l->new_chunk_sectors;
 275}
 276
 277/* raid10 algorithms (i.e. formats) */
 278#define	ALGORITHM_RAID10_DEFAULT	0
 279#define	ALGORITHM_RAID10_NEAR		1
 280#define	ALGORITHM_RAID10_OFFSET		2
 281#define	ALGORITHM_RAID10_FAR		3
 282
 283/* Supported raid types and properties. */
 284static struct raid_type {
 285	const char *name;		/* RAID algorithm. */
 286	const char *descr;		/* Descriptor text for logging. */
 287	const unsigned int parity_devs;	/* # of parity devices. */
 288	const unsigned int minimal_devs;/* minimal # of devices in set. */
 289	const unsigned int level;	/* RAID level. */
 290	const unsigned int algorithm;	/* RAID algorithm. */
 291} raid_types[] = {
 292	{"raid0",	  "raid0 (striping)",			    0, 2, 0,  0 /* NONE */},
 293	{"raid1",	  "raid1 (mirroring)",			    0, 2, 1,  0 /* NONE */},
 294	{"raid10_far",	  "raid10 far (striped mirrors)",	    0, 2, 10, ALGORITHM_RAID10_FAR},
 295	{"raid10_offset", "raid10 offset (striped mirrors)",	    0, 2, 10, ALGORITHM_RAID10_OFFSET},
 296	{"raid10_near",	  "raid10 near (striped mirrors)",	    0, 2, 10, ALGORITHM_RAID10_NEAR},
 297	{"raid10",	  "raid10 (striped mirrors)",		    0, 2, 10, ALGORITHM_RAID10_DEFAULT},
 298	{"raid4",	  "raid4 (dedicated first parity disk)",    1, 2, 5,  ALGORITHM_PARITY_0}, /* raid4 layout = raid5_0 */
 299	{"raid5_n",	  "raid5 (dedicated last parity disk)",	    1, 2, 5,  ALGORITHM_PARITY_N},
 300	{"raid5_ls",	  "raid5 (left symmetric)",		    1, 2, 5,  ALGORITHM_LEFT_SYMMETRIC},
 301	{"raid5_rs",	  "raid5 (right symmetric)",		    1, 2, 5,  ALGORITHM_RIGHT_SYMMETRIC},
 302	{"raid5_la",	  "raid5 (left asymmetric)",		    1, 2, 5,  ALGORITHM_LEFT_ASYMMETRIC},
 303	{"raid5_ra",	  "raid5 (right asymmetric)",		    1, 2, 5,  ALGORITHM_RIGHT_ASYMMETRIC},
 304	{"raid6_zr",	  "raid6 (zero restart)",		    2, 4, 6,  ALGORITHM_ROTATING_ZERO_RESTART},
 305	{"raid6_nr",	  "raid6 (N restart)",			    2, 4, 6,  ALGORITHM_ROTATING_N_RESTART},
 306	{"raid6_nc",	  "raid6 (N continue)",			    2, 4, 6,  ALGORITHM_ROTATING_N_CONTINUE},
 307	{"raid6_n_6",	  "raid6 (dedicated parity/Q n/6)",	    2, 4, 6,  ALGORITHM_PARITY_N_6},
 308	{"raid6_ls_6",	  "raid6 (left symmetric dedicated Q 6)",   2, 4, 6,  ALGORITHM_LEFT_SYMMETRIC_6},
 309	{"raid6_rs_6",	  "raid6 (right symmetric dedicated Q 6)",  2, 4, 6,  ALGORITHM_RIGHT_SYMMETRIC_6},
 310	{"raid6_la_6",	  "raid6 (left asymmetric dedicated Q 6)",  2, 4, 6,  ALGORITHM_LEFT_ASYMMETRIC_6},
 311	{"raid6_ra_6",	  "raid6 (right asymmetric dedicated Q 6)", 2, 4, 6,  ALGORITHM_RIGHT_ASYMMETRIC_6}
 312};
 313
 314/* True, if @v is in inclusive range [@min, @max] */
 315static bool __within_range(long v, long min, long max)
 316{
 317	return v >= min && v <= max;
 318}
 319
 320/* All table line arguments are defined here */
 321static struct arg_name_flag {
 322	const unsigned long flag;
 323	const char *name;
 324} __arg_name_flags[] = {
 325	{ CTR_FLAG_SYNC, "sync"},
 326	{ CTR_FLAG_NOSYNC, "nosync"},
 327	{ CTR_FLAG_REBUILD, "rebuild"},
 328	{ CTR_FLAG_DAEMON_SLEEP, "daemon_sleep"},
 329	{ CTR_FLAG_MIN_RECOVERY_RATE, "min_recovery_rate"},
 330	{ CTR_FLAG_MAX_RECOVERY_RATE, "max_recovery_rate"},
 331	{ CTR_FLAG_MAX_WRITE_BEHIND, "max_write_behind"},
 332	{ CTR_FLAG_WRITE_MOSTLY, "write_mostly"},
 333	{ CTR_FLAG_STRIPE_CACHE, "stripe_cache"},
 334	{ CTR_FLAG_REGION_SIZE, "region_size"},
 335	{ CTR_FLAG_RAID10_COPIES, "raid10_copies"},
 336	{ CTR_FLAG_RAID10_FORMAT, "raid10_format"},
 337	{ CTR_FLAG_DATA_OFFSET, "data_offset"},
 338	{ CTR_FLAG_DELTA_DISKS, "delta_disks"},
 339	{ CTR_FLAG_RAID10_USE_NEAR_SETS, "raid10_use_near_sets"},
 340	{ CTR_FLAG_JOURNAL_DEV, "journal_dev" },
 341	{ CTR_FLAG_JOURNAL_MODE, "journal_mode" },
 342};
 343
 344/* Return argument name string for given @flag */
 345static const char *dm_raid_arg_name_by_flag(const uint32_t flag)
 346{
 347	if (hweight32(flag) == 1) {
 348		struct arg_name_flag *anf = __arg_name_flags + ARRAY_SIZE(__arg_name_flags);
 349
 350		while (anf-- > __arg_name_flags)
 351			if (flag & anf->flag)
 352				return anf->name;
 353
 354	} else
 355		DMERR("%s called with more than one flag!", __func__);
 356
 357	return NULL;
 358}
 359
 360/* Define correlation of raid456 journal cache modes and dm-raid target line parameters */
 361static struct {
 362	const int mode;
 363	const char *param;
 364} _raid456_journal_mode[] = {
 365	{ R5C_JOURNAL_MODE_WRITE_THROUGH , "writethrough" },
 366	{ R5C_JOURNAL_MODE_WRITE_BACK    , "writeback" }
 367};
 368
 369/* Return MD raid4/5/6 journal mode for dm @journal_mode one */
 370static int dm_raid_journal_mode_to_md(const char *mode)
 371{
 372	int m = ARRAY_SIZE(_raid456_journal_mode);
 373
 374	while (m--)
 375		if (!strcasecmp(mode, _raid456_journal_mode[m].param))
 376			return _raid456_journal_mode[m].mode;
 377
 378	return -EINVAL;
 379}
 380
 381/* Return dm-raid raid4/5/6 journal mode string for @mode */
 382static const char *md_journal_mode_to_dm_raid(const int mode)
 383{
 384	int m = ARRAY_SIZE(_raid456_journal_mode);
 385
 386	while (m--)
 387		if (mode == _raid456_journal_mode[m].mode)
 388			return _raid456_journal_mode[m].param;
 389
 390	return "unknown";
 391}
 392
 393/*
 394 * Bool helpers to test for various raid levels of a raid set.
 395 * It's level as reported by the superblock rather than
 396 * the requested raid_type passed to the constructor.
 397 */
 398/* Return true, if raid set in @rs is raid0 */
 399static bool rs_is_raid0(struct raid_set *rs)
 400{
 401	return !rs->md.level;
 402}
 403
 404/* Return true, if raid set in @rs is raid1 */
 405static bool rs_is_raid1(struct raid_set *rs)
 406{
 407	return rs->md.level == 1;
 408}
 409
 410/* Return true, if raid set in @rs is raid10 */
 411static bool rs_is_raid10(struct raid_set *rs)
 412{
 413	return rs->md.level == 10;
 414}
 415
 416/* Return true, if raid set in @rs is level 6 */
 417static bool rs_is_raid6(struct raid_set *rs)
 418{
 419	return rs->md.level == 6;
 420}
 421
 422/* Return true, if raid set in @rs is level 4, 5 or 6 */
 423static bool rs_is_raid456(struct raid_set *rs)
 424{
 425	return __within_range(rs->md.level, 4, 6);
 426}
 427
 428/* Return true, if raid set in @rs is reshapable */
 429static bool __is_raid10_far(int layout);
 430static bool rs_is_reshapable(struct raid_set *rs)
 431{
 432	return rs_is_raid456(rs) ||
 433	       (rs_is_raid10(rs) && !__is_raid10_far(rs->md.new_layout));
 434}
 435
 436/* Return true, if raid set in @rs is recovering */
 437static bool rs_is_recovering(struct raid_set *rs)
 438{
 439	return rs->md.recovery_cp < rs->md.dev_sectors;
 440}
 441
 442/* Return true, if raid set in @rs is reshaping */
 443static bool rs_is_reshaping(struct raid_set *rs)
 444{
 445	return rs->md.reshape_position != MaxSector;
 446}
 447
 448/*
 449 * bool helpers to test for various raid levels of a raid type @rt
 450 */
 451
 452/* Return true, if raid type in @rt is raid0 */
 453static bool rt_is_raid0(struct raid_type *rt)
 454{
 455	return !rt->level;
 456}
 457
 458/* Return true, if raid type in @rt is raid1 */
 459static bool rt_is_raid1(struct raid_type *rt)
 460{
 461	return rt->level == 1;
 462}
 463
 464/* Return true, if raid type in @rt is raid10 */
 465static bool rt_is_raid10(struct raid_type *rt)
 466{
 467	return rt->level == 10;
 468}
 469
 470/* Return true, if raid type in @rt is raid4/5 */
 471static bool rt_is_raid45(struct raid_type *rt)
 472{
 473	return __within_range(rt->level, 4, 5);
 474}
 475
 476/* Return true, if raid type in @rt is raid6 */
 477static bool rt_is_raid6(struct raid_type *rt)
 478{
 479	return rt->level == 6;
 480}
 481
 482/* Return true, if raid type in @rt is raid4/5/6 */
 483static bool rt_is_raid456(struct raid_type *rt)
 484{
 485	return __within_range(rt->level, 4, 6);
 486}
 487/* END: raid level bools */
 488
 489/* Return valid ctr flags for the raid level of @rs */
 490static unsigned long __valid_flags(struct raid_set *rs)
 491{
 492	if (rt_is_raid0(rs->raid_type))
 493		return RAID0_VALID_FLAGS;
 494	else if (rt_is_raid1(rs->raid_type))
 495		return RAID1_VALID_FLAGS;
 496	else if (rt_is_raid10(rs->raid_type))
 497		return RAID10_VALID_FLAGS;
 498	else if (rt_is_raid45(rs->raid_type))
 499		return RAID45_VALID_FLAGS;
 500	else if (rt_is_raid6(rs->raid_type))
 501		return RAID6_VALID_FLAGS;
 502
 503	return 0;
 504}
 505
 506/*
 507 * Check for valid flags set on @rs
 508 *
 509 * Has to be called after parsing of the ctr flags!
 510 */
 511static int rs_check_for_valid_flags(struct raid_set *rs)
 512{
 513	if (rs->ctr_flags & ~__valid_flags(rs)) {
 514		rs->ti->error = "Invalid flags combination";
 515		return -EINVAL;
 516	}
 517
 518	return 0;
 519}
 520
 521/* MD raid10 bit definitions and helpers */
 522#define RAID10_OFFSET			(1 << 16) /* stripes with data copies area adjacent on devices */
 523#define RAID10_BROCKEN_USE_FAR_SETS	(1 << 17) /* Broken in raid10.c: use sets instead of whole stripe rotation */
 524#define RAID10_USE_FAR_SETS		(1 << 18) /* Use sets instead of whole stripe rotation */
 525#define RAID10_FAR_COPIES_SHIFT		8	  /* raid10 # far copies shift (2nd byte of layout) */
 526
 527/* Return md raid10 near copies for @layout */
 528static unsigned int __raid10_near_copies(int layout)
 529{
 530	return layout & 0xFF;
 531}
 532
 533/* Return md raid10 far copies for @layout */
 534static unsigned int __raid10_far_copies(int layout)
 535{
 536	return __raid10_near_copies(layout >> RAID10_FAR_COPIES_SHIFT);
 537}
 538
 539/* Return true if md raid10 offset for @layout */
 540static bool __is_raid10_offset(int layout)
 541{
 542	return !!(layout & RAID10_OFFSET);
 543}
 544
 545/* Return true if md raid10 near for @layout */
 546static bool __is_raid10_near(int layout)
 547{
 548	return !__is_raid10_offset(layout) && __raid10_near_copies(layout) > 1;
 549}
 550
 551/* Return true if md raid10 far for @layout */
 552static bool __is_raid10_far(int layout)
 553{
 554	return !__is_raid10_offset(layout) && __raid10_far_copies(layout) > 1;
 555}
 556
 557/* Return md raid10 layout string for @layout */
 558static const char *raid10_md_layout_to_format(int layout)
 559{
 560	/*
 561	 * Bit 16 stands for "offset"
 562	 * (i.e. adjacent stripes hold copies)
 563	 *
 564	 * Refer to MD's raid10.c for details
 565	 */
 566	if (__is_raid10_offset(layout))
 567		return "offset";
 568
 569	if (__raid10_near_copies(layout) > 1)
 570		return "near";
 571
 572	if (__raid10_far_copies(layout) > 1)
 573		return "far";
 574
 575	return "unknown";
 576}
 577
 578/* Return md raid10 algorithm for @name */
 579static int raid10_name_to_format(const char *name)
 580{
 581	if (!strcasecmp(name, "near"))
 582		return ALGORITHM_RAID10_NEAR;
 583	else if (!strcasecmp(name, "offset"))
 584		return ALGORITHM_RAID10_OFFSET;
 585	else if (!strcasecmp(name, "far"))
 586		return ALGORITHM_RAID10_FAR;
 587
 588	return -EINVAL;
 589}
 590
 591/* Return md raid10 copies for @layout */
 592static unsigned int raid10_md_layout_to_copies(int layout)
 593{
 594	return max(__raid10_near_copies(layout), __raid10_far_copies(layout));
 595}
 596
 597/* Return md raid10 format id for @format string */
 598static int raid10_format_to_md_layout(struct raid_set *rs,
 599				      unsigned int algorithm,
 600				      unsigned int copies)
 601{
 602	unsigned int n = 1, f = 1, r = 0;
 603
 604	/*
 605	 * MD resilienece flaw:
 606	 *
 607	 * enabling use_far_sets for far/offset formats causes copies
 608	 * to be colocated on the same devs together with their origins!
 609	 *
 610	 * -> disable it for now in the definition above
 611	 */
 612	if (algorithm == ALGORITHM_RAID10_DEFAULT ||
 613	    algorithm == ALGORITHM_RAID10_NEAR)
 614		n = copies;
 615
 616	else if (algorithm == ALGORITHM_RAID10_OFFSET) {
 617		f = copies;
 618		r = RAID10_OFFSET;
 619		if (!test_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags))
 620			r |= RAID10_USE_FAR_SETS;
 621
 622	} else if (algorithm == ALGORITHM_RAID10_FAR) {
 623		f = copies;
 624		if (!test_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags))
 625			r |= RAID10_USE_FAR_SETS;
 626
 627	} else
 628		return -EINVAL;
 629
 630	return r | (f << RAID10_FAR_COPIES_SHIFT) | n;
 631}
 632/* END: MD raid10 bit definitions and helpers */
 633
 634/* Check for any of the raid10 algorithms */
 635static bool __got_raid10(struct raid_type *rtp, const int layout)
 636{
 637	if (rtp->level == 10) {
 638		switch (rtp->algorithm) {
 639		case ALGORITHM_RAID10_DEFAULT:
 640		case ALGORITHM_RAID10_NEAR:
 641			return __is_raid10_near(layout);
 642		case ALGORITHM_RAID10_OFFSET:
 643			return __is_raid10_offset(layout);
 644		case ALGORITHM_RAID10_FAR:
 645			return __is_raid10_far(layout);
 646		default:
 647			break;
 648		}
 649	}
 650
 651	return false;
 652}
 653
 654/* Return raid_type for @name */
 655static struct raid_type *get_raid_type(const char *name)
 656{
 657	struct raid_type *rtp = raid_types + ARRAY_SIZE(raid_types);
 658
 659	while (rtp-- > raid_types)
 660		if (!strcasecmp(rtp->name, name))
 661			return rtp;
 662
 663	return NULL;
 664}
 665
 666/* Return raid_type for @name based derived from @level and @layout */
 667static struct raid_type *get_raid_type_by_ll(const int level, const int layout)
 668{
 669	struct raid_type *rtp = raid_types + ARRAY_SIZE(raid_types);
 670
 671	while (rtp-- > raid_types) {
 672		/* RAID10 special checks based on @layout flags/properties */
 673		if (rtp->level == level &&
 674		    (__got_raid10(rtp, layout) || rtp->algorithm == layout))
 675			return rtp;
 676	}
 677
 678	return NULL;
 679}
 680
 681/* Adjust rdev sectors */
 682static void rs_set_rdev_sectors(struct raid_set *rs)
 683{
 684	struct mddev *mddev = &rs->md;
 685	struct md_rdev *rdev;
 686
 687	/*
 688	 * raid10 sets rdev->sector to the device size, which
 689	 * is unintended in case of out-of-place reshaping
 690	 */
 691	rdev_for_each(rdev, mddev)
 692		if (!test_bit(Journal, &rdev->flags))
 693			rdev->sectors = mddev->dev_sectors;
 694}
 695
 696/*
 697 * Change bdev capacity of @rs in case of a disk add/remove reshape
 698 */
 699static void rs_set_capacity(struct raid_set *rs)
 700{
 701	struct gendisk *gendisk = dm_disk(dm_table_get_md(rs->ti->table));
 702
 703	set_capacity_and_notify(gendisk, rs->md.array_sectors);
 
 704}
 705
 706/*
 707 * Set the mddev properties in @rs to the current
 708 * ones retrieved from the freshest superblock
 709 */
 710static void rs_set_cur(struct raid_set *rs)
 711{
 712	struct mddev *mddev = &rs->md;
 713
 714	mddev->new_level = mddev->level;
 715	mddev->new_layout = mddev->layout;
 716	mddev->new_chunk_sectors = mddev->chunk_sectors;
 717}
 718
 719/*
 720 * Set the mddev properties in @rs to the new
 721 * ones requested by the ctr
 722 */
 723static void rs_set_new(struct raid_set *rs)
 724{
 725	struct mddev *mddev = &rs->md;
 726
 727	mddev->level = mddev->new_level;
 728	mddev->layout = mddev->new_layout;
 729	mddev->chunk_sectors = mddev->new_chunk_sectors;
 730	mddev->raid_disks = rs->raid_disks;
 731	mddev->delta_disks = 0;
 732}
 733
 734static struct raid_set *raid_set_alloc(struct dm_target *ti, struct raid_type *raid_type,
 735				       unsigned int raid_devs)
 736{
 737	unsigned int i;
 738	struct raid_set *rs;
 739
 740	if (raid_devs <= raid_type->parity_devs) {
 741		ti->error = "Insufficient number of devices";
 742		return ERR_PTR(-EINVAL);
 743	}
 744
 745	rs = kzalloc(struct_size(rs, dev, raid_devs), GFP_KERNEL);
 746	if (!rs) {
 747		ti->error = "Cannot allocate raid context";
 748		return ERR_PTR(-ENOMEM);
 749	}
 750
 751	mddev_init(&rs->md);
 752
 753	rs->raid_disks = raid_devs;
 754	rs->delta_disks = 0;
 755
 756	rs->ti = ti;
 757	rs->raid_type = raid_type;
 758	rs->stripe_cache_entries = 256;
 759	rs->md.raid_disks = raid_devs;
 760	rs->md.level = raid_type->level;
 761	rs->md.new_level = rs->md.level;
 762	rs->md.layout = raid_type->algorithm;
 763	rs->md.new_layout = rs->md.layout;
 764	rs->md.delta_disks = 0;
 765	rs->md.recovery_cp = MaxSector;
 766
 767	for (i = 0; i < raid_devs; i++)
 768		md_rdev_init(&rs->dev[i].rdev);
 769
 770	/*
 771	 * Remaining items to be initialized by further RAID params:
 772	 *  rs->md.persistent
 773	 *  rs->md.external
 774	 *  rs->md.chunk_sectors
 775	 *  rs->md.new_chunk_sectors
 776	 *  rs->md.dev_sectors
 777	 */
 778
 779	return rs;
 780}
 781
 782/* Free all @rs allocations */
 783static void raid_set_free(struct raid_set *rs)
 784{
 785	int i;
 786
 787	if (rs->journal_dev.dev) {
 788		md_rdev_clear(&rs->journal_dev.rdev);
 789		dm_put_device(rs->ti, rs->journal_dev.dev);
 790	}
 791
 792	for (i = 0; i < rs->raid_disks; i++) {
 793		if (rs->dev[i].meta_dev)
 794			dm_put_device(rs->ti, rs->dev[i].meta_dev);
 795		md_rdev_clear(&rs->dev[i].rdev);
 796		if (rs->dev[i].data_dev)
 797			dm_put_device(rs->ti, rs->dev[i].data_dev);
 798	}
 799
 800	kfree(rs);
 801}
 802
 803/*
 804 * For every device we have two words
 805 *  <meta_dev>: meta device name or '-' if missing
 806 *  <data_dev>: data device name or '-' if missing
 807 *
 808 * The following are permitted:
 809 *    - -
 810 *    - <data_dev>
 811 *    <meta_dev> <data_dev>
 812 *
 813 * The following is not allowed:
 814 *    <meta_dev> -
 815 *
 816 * This code parses those words.  If there is a failure,
 817 * the caller must use raid_set_free() to unwind the operations.
 818 */
 819static int parse_dev_params(struct raid_set *rs, struct dm_arg_set *as)
 820{
 821	int i;
 822	int rebuild = 0;
 823	int metadata_available = 0;
 824	int r = 0;
 825	const char *arg;
 826
 827	/* Put off the number of raid devices argument to get to dev pairs */
 828	arg = dm_shift_arg(as);
 829	if (!arg)
 830		return -EINVAL;
 831
 832	for (i = 0; i < rs->raid_disks; i++) {
 833		rs->dev[i].rdev.raid_disk = i;
 834
 835		rs->dev[i].meta_dev = NULL;
 836		rs->dev[i].data_dev = NULL;
 837
 838		/*
 839		 * There are no offsets initially.
 840		 * Out of place reshape will set them accordingly.
 841		 */
 842		rs->dev[i].rdev.data_offset = 0;
 843		rs->dev[i].rdev.new_data_offset = 0;
 844		rs->dev[i].rdev.mddev = &rs->md;
 845
 846		arg = dm_shift_arg(as);
 847		if (!arg)
 848			return -EINVAL;
 849
 850		if (strcmp(arg, "-")) {
 851			r = dm_get_device(rs->ti, arg, dm_table_get_mode(rs->ti->table),
 852					  &rs->dev[i].meta_dev);
 853			if (r) {
 854				rs->ti->error = "RAID metadata device lookup failure";
 855				return r;
 856			}
 857
 858			rs->dev[i].rdev.sb_page = alloc_page(GFP_KERNEL);
 859			if (!rs->dev[i].rdev.sb_page) {
 860				rs->ti->error = "Failed to allocate superblock page";
 861				return -ENOMEM;
 862			}
 863		}
 864
 865		arg = dm_shift_arg(as);
 866		if (!arg)
 867			return -EINVAL;
 868
 869		if (!strcmp(arg, "-")) {
 870			if (!test_bit(In_sync, &rs->dev[i].rdev.flags) &&
 871			    (!rs->dev[i].rdev.recovery_offset)) {
 872				rs->ti->error = "Drive designated for rebuild not specified";
 873				return -EINVAL;
 874			}
 875
 876			if (rs->dev[i].meta_dev) {
 877				rs->ti->error = "No data device supplied with metadata device";
 878				return -EINVAL;
 879			}
 880
 881			continue;
 882		}
 883
 884		r = dm_get_device(rs->ti, arg, dm_table_get_mode(rs->ti->table),
 885				  &rs->dev[i].data_dev);
 886		if (r) {
 887			rs->ti->error = "RAID device lookup failure";
 888			return r;
 889		}
 890
 891		if (rs->dev[i].meta_dev) {
 892			metadata_available = 1;
 893			rs->dev[i].rdev.meta_bdev = rs->dev[i].meta_dev->bdev;
 894		}
 895		rs->dev[i].rdev.bdev = rs->dev[i].data_dev->bdev;
 896		list_add_tail(&rs->dev[i].rdev.same_set, &rs->md.disks);
 897		if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
 898			rebuild++;
 899	}
 900
 901	if (rs->journal_dev.dev)
 902		list_add_tail(&rs->journal_dev.rdev.same_set, &rs->md.disks);
 903
 904	if (metadata_available) {
 905		rs->md.external = 0;
 906		rs->md.persistent = 1;
 907		rs->md.major_version = 2;
 908	} else if (rebuild && !rs->md.recovery_cp) {
 909		/*
 910		 * Without metadata, we will not be able to tell if the array
 911		 * is in-sync or not - we must assume it is not.  Therefore,
 912		 * it is impossible to rebuild a drive.
 913		 *
 914		 * Even if there is metadata, the on-disk information may
 915		 * indicate that the array is not in-sync and it will then
 916		 * fail at that time.
 917		 *
 918		 * User could specify 'nosync' option if desperate.
 919		 */
 920		rs->ti->error = "Unable to rebuild drive while array is not in-sync";
 921		return -EINVAL;
 922	}
 923
 924	return 0;
 925}
 926
 927/*
 928 * validate_region_size
 929 * @rs
 930 * @region_size:  region size in sectors.  If 0, pick a size (4MiB default).
 931 *
 932 * Set rs->md.bitmap_info.chunksize (which really refers to 'region size').
 933 * Ensure that (ti->len/region_size < 2^21) - required by MD bitmap.
 934 *
 935 * Returns: 0 on success, -EINVAL on failure.
 936 */
 937static int validate_region_size(struct raid_set *rs, unsigned long region_size)
 938{
 939	unsigned long min_region_size = rs->ti->len / (1 << 21);
 940
 941	if (rs_is_raid0(rs))
 942		return 0;
 943
 944	if (!region_size) {
 945		/*
 946		 * Choose a reasonable default.	 All figures in sectors.
 947		 */
 948		if (min_region_size > (1 << 13)) {
 949			/* If not a power of 2, make it the next power of 2 */
 950			region_size = roundup_pow_of_two(min_region_size);
 951			DMINFO("Choosing default region size of %lu sectors",
 952			       region_size);
 953		} else {
 954			DMINFO("Choosing default region size of 4MiB");
 955			region_size = 1 << 13; /* sectors */
 956		}
 957	} else {
 958		/*
 959		 * Validate user-supplied value.
 960		 */
 961		if (region_size > rs->ti->len) {
 962			rs->ti->error = "Supplied region size is too large";
 963			return -EINVAL;
 964		}
 965
 966		if (region_size < min_region_size) {
 967			DMERR("Supplied region_size (%lu sectors) below minimum (%lu)",
 968			      region_size, min_region_size);
 969			rs->ti->error = "Supplied region size is too small";
 970			return -EINVAL;
 971		}
 972
 973		if (!is_power_of_2(region_size)) {
 974			rs->ti->error = "Region size is not a power of 2";
 975			return -EINVAL;
 976		}
 977
 978		if (region_size < rs->md.chunk_sectors) {
 979			rs->ti->error = "Region size is smaller than the chunk size";
 980			return -EINVAL;
 981		}
 982	}
 983
 984	/*
 985	 * Convert sectors to bytes.
 986	 */
 987	rs->md.bitmap_info.chunksize = to_bytes(region_size);
 988
 989	return 0;
 990}
 991
 992/*
 993 * validate_raid_redundancy
 994 * @rs
 995 *
 996 * Determine if there are enough devices in the array that haven't
 997 * failed (or are being rebuilt) to form a usable array.
 998 *
 999 * Returns: 0 on success, -EINVAL on failure.
1000 */
1001static int validate_raid_redundancy(struct raid_set *rs)
1002{
1003	unsigned int i, rebuild_cnt = 0;
1004	unsigned int rebuilds_per_group = 0, copies;
1005	unsigned int group_size, last_group_start;
1006
1007	for (i = 0; i < rs->md.raid_disks; i++)
1008		if (!test_bit(In_sync, &rs->dev[i].rdev.flags) ||
1009		    !rs->dev[i].rdev.sb_page)
1010			rebuild_cnt++;
1011
1012	switch (rs->md.level) {
1013	case 0:
1014		break;
1015	case 1:
1016		if (rebuild_cnt >= rs->md.raid_disks)
1017			goto too_many;
1018		break;
1019	case 4:
1020	case 5:
1021	case 6:
1022		if (rebuild_cnt > rs->raid_type->parity_devs)
1023			goto too_many;
1024		break;
1025	case 10:
1026		copies = raid10_md_layout_to_copies(rs->md.new_layout);
1027		if (copies < 2) {
1028			DMERR("Bogus raid10 data copies < 2!");
1029			return -EINVAL;
1030		}
1031
1032		if (rebuild_cnt < copies)
1033			break;
1034
1035		/*
1036		 * It is possible to have a higher rebuild count for RAID10,
1037		 * as long as the failed devices occur in different mirror
1038		 * groups (i.e. different stripes).
1039		 *
1040		 * When checking "near" format, make sure no adjacent devices
1041		 * have failed beyond what can be handled.  In addition to the
1042		 * simple case where the number of devices is a multiple of the
1043		 * number of copies, we must also handle cases where the number
1044		 * of devices is not a multiple of the number of copies.
1045		 * E.g.	   dev1 dev2 dev3 dev4 dev5
1046		 *	    A	 A    B	   B	C
1047		 *	    C	 D    D	   E	E
1048		 */
1049		if (__is_raid10_near(rs->md.new_layout)) {
1050			for (i = 0; i < rs->md.raid_disks; i++) {
1051				if (!(i % copies))
1052					rebuilds_per_group = 0;
1053				if ((!rs->dev[i].rdev.sb_page ||
1054				    !test_bit(In_sync, &rs->dev[i].rdev.flags)) &&
1055				    (++rebuilds_per_group >= copies))
1056					goto too_many;
1057			}
1058			break;
1059		}
1060
1061		/*
1062		 * When checking "far" and "offset" formats, we need to ensure
1063		 * that the device that holds its copy is not also dead or
1064		 * being rebuilt.  (Note that "far" and "offset" formats only
1065		 * support two copies right now.  These formats also only ever
1066		 * use the 'use_far_sets' variant.)
1067		 *
1068		 * This check is somewhat complicated by the need to account
1069		 * for arrays that are not a multiple of (far) copies.	This
1070		 * results in the need to treat the last (potentially larger)
1071		 * set differently.
1072		 */
1073		group_size = (rs->md.raid_disks / copies);
1074		last_group_start = (rs->md.raid_disks / group_size) - 1;
1075		last_group_start *= group_size;
1076		for (i = 0; i < rs->md.raid_disks; i++) {
1077			if (!(i % copies) && !(i > last_group_start))
1078				rebuilds_per_group = 0;
1079			if ((!rs->dev[i].rdev.sb_page ||
1080			     !test_bit(In_sync, &rs->dev[i].rdev.flags)) &&
1081			    (++rebuilds_per_group >= copies))
1082					goto too_many;
1083		}
1084		break;
1085	default:
1086		if (rebuild_cnt)
1087			return -EINVAL;
1088	}
1089
1090	return 0;
1091
1092too_many:
1093	return -EINVAL;
1094}
1095
1096/*
1097 * Possible arguments are...
1098 *	<chunk_size> [optional_args]
1099 *
1100 * Argument definitions
1101 *    <chunk_size>			The number of sectors per disk that
1102 *					will form the "stripe"
1103 *    [[no]sync]			Force or prevent recovery of the
1104 *					entire array
1105 *    [rebuild <idx>]			Rebuild the drive indicated by the index
1106 *    [daemon_sleep <ms>]		Time between bitmap daemon work to
1107 *					clear bits
1108 *    [min_recovery_rate <kB/sec/disk>]	Throttle RAID initialization
1109 *    [max_recovery_rate <kB/sec/disk>]	Throttle RAID initialization
1110 *    [write_mostly <idx>]		Indicate a write mostly drive via index
1111 *    [max_write_behind <sectors>]	See '-write-behind=' (man mdadm)
1112 *    [stripe_cache <sectors>]		Stripe cache size for higher RAIDs
1113 *    [region_size <sectors>]		Defines granularity of bitmap
1114 *    [journal_dev <dev>]		raid4/5/6 journaling deviice
1115 *    					(i.e. write hole closing log)
1116 *
1117 * RAID10-only options:
1118 *    [raid10_copies <# copies>]	Number of copies.  (Default: 2)
1119 *    [raid10_format <near|far|offset>] Layout algorithm.  (Default: near)
1120 */
1121static int parse_raid_params(struct raid_set *rs, struct dm_arg_set *as,
1122			     unsigned int num_raid_params)
1123{
1124	int value, raid10_format = ALGORITHM_RAID10_DEFAULT;
1125	unsigned int raid10_copies = 2;
1126	unsigned int i, write_mostly = 0;
1127	unsigned int region_size = 0;
1128	sector_t max_io_len;
1129	const char *arg, *key;
1130	struct raid_dev *rd;
1131	struct raid_type *rt = rs->raid_type;
1132
1133	arg = dm_shift_arg(as);
1134	num_raid_params--; /* Account for chunk_size argument */
1135
1136	if (kstrtoint(arg, 10, &value) < 0) {
1137		rs->ti->error = "Bad numerical argument given for chunk_size";
1138		return -EINVAL;
1139	}
1140
1141	/*
1142	 * First, parse the in-order required arguments
1143	 * "chunk_size" is the only argument of this type.
1144	 */
1145	if (rt_is_raid1(rt)) {
1146		if (value)
1147			DMERR("Ignoring chunk size parameter for RAID 1");
1148		value = 0;
1149	} else if (!is_power_of_2(value)) {
1150		rs->ti->error = "Chunk size must be a power of 2";
1151		return -EINVAL;
1152	} else if (value < 8) {
1153		rs->ti->error = "Chunk size value is too small";
1154		return -EINVAL;
1155	}
1156
1157	rs->md.new_chunk_sectors = rs->md.chunk_sectors = value;
1158
1159	/*
1160	 * We set each individual device as In_sync with a completed
1161	 * 'recovery_offset'.  If there has been a device failure or
1162	 * replacement then one of the following cases applies:
1163	 *
1164	 *   1) User specifies 'rebuild'.
1165	 *	- Device is reset when param is read.
1166	 *   2) A new device is supplied.
1167	 *	- No matching superblock found, resets device.
1168	 *   3) Device failure was transient and returns on reload.
1169	 *	- Failure noticed, resets device for bitmap replay.
1170	 *   4) Device hadn't completed recovery after previous failure.
1171	 *	- Superblock is read and overrides recovery_offset.
1172	 *
1173	 * What is found in the superblocks of the devices is always
1174	 * authoritative, unless 'rebuild' or '[no]sync' was specified.
1175	 */
1176	for (i = 0; i < rs->raid_disks; i++) {
1177		set_bit(In_sync, &rs->dev[i].rdev.flags);
1178		rs->dev[i].rdev.recovery_offset = MaxSector;
1179	}
1180
1181	/*
1182	 * Second, parse the unordered optional arguments
1183	 */
1184	for (i = 0; i < num_raid_params; i++) {
1185		key = dm_shift_arg(as);
1186		if (!key) {
1187			rs->ti->error = "Not enough raid parameters given";
1188			return -EINVAL;
1189		}
1190
1191		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_NOSYNC))) {
1192			if (test_and_set_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
1193				rs->ti->error = "Only one 'nosync' argument allowed";
1194				return -EINVAL;
1195			}
1196			continue;
1197		}
1198		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_SYNC))) {
1199			if (test_and_set_bit(__CTR_FLAG_SYNC, &rs->ctr_flags)) {
1200				rs->ti->error = "Only one 'sync' argument allowed";
1201				return -EINVAL;
1202			}
1203			continue;
1204		}
1205		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_USE_NEAR_SETS))) {
1206			if (test_and_set_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags)) {
1207				rs->ti->error = "Only one 'raid10_use_new_sets' argument allowed";
1208				return -EINVAL;
1209			}
1210			continue;
1211		}
1212
1213		arg = dm_shift_arg(as);
1214		i++; /* Account for the argument pairs */
1215		if (!arg) {
1216			rs->ti->error = "Wrong number of raid parameters given";
1217			return -EINVAL;
1218		}
1219
1220		/*
1221		 * Parameters that take a string value are checked here.
1222		 */
1223		/* "raid10_format {near|offset|far} */
1224		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_FORMAT))) {
1225			if (test_and_set_bit(__CTR_FLAG_RAID10_FORMAT, &rs->ctr_flags)) {
1226				rs->ti->error = "Only one 'raid10_format' argument pair allowed";
1227				return -EINVAL;
1228			}
1229			if (!rt_is_raid10(rt)) {
1230				rs->ti->error = "'raid10_format' is an invalid parameter for this RAID type";
1231				return -EINVAL;
1232			}
1233			raid10_format = raid10_name_to_format(arg);
1234			if (raid10_format < 0) {
1235				rs->ti->error = "Invalid 'raid10_format' value given";
1236				return raid10_format;
1237			}
1238			continue;
1239		}
1240
1241		/* "journal_dev <dev>" */
1242		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_DEV))) {
1243			int r;
1244			struct md_rdev *jdev;
1245
1246			if (test_and_set_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
1247				rs->ti->error = "Only one raid4/5/6 set journaling device allowed";
1248				return -EINVAL;
1249			}
1250			if (!rt_is_raid456(rt)) {
1251				rs->ti->error = "'journal_dev' is an invalid parameter for this RAID type";
1252				return -EINVAL;
1253			}
1254			r = dm_get_device(rs->ti, arg, dm_table_get_mode(rs->ti->table),
1255					  &rs->journal_dev.dev);
1256			if (r) {
1257				rs->ti->error = "raid4/5/6 journal device lookup failure";
1258				return r;
1259			}
1260			jdev = &rs->journal_dev.rdev;
1261			md_rdev_init(jdev);
1262			jdev->mddev = &rs->md;
1263			jdev->bdev = rs->journal_dev.dev->bdev;
1264			jdev->sectors = to_sector(i_size_read(jdev->bdev->bd_inode));
1265			if (jdev->sectors < MIN_RAID456_JOURNAL_SPACE) {
1266				rs->ti->error = "No space for raid4/5/6 journal";
1267				return -ENOSPC;
1268			}
1269			rs->journal_dev.mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
1270			set_bit(Journal, &jdev->flags);
1271			continue;
1272		}
1273
1274		/* "journal_mode <mode>" ("journal_dev" mandatory!) */
1275		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_MODE))) {
1276			int r;
1277
1278			if (!test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
1279				rs->ti->error = "raid4/5/6 'journal_mode' is invalid without 'journal_dev'";
1280				return -EINVAL;
1281			}
1282			if (test_and_set_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags)) {
1283				rs->ti->error = "Only one raid4/5/6 'journal_mode' argument allowed";
1284				return -EINVAL;
1285			}
1286			r = dm_raid_journal_mode_to_md(arg);
1287			if (r < 0) {
1288				rs->ti->error = "Invalid 'journal_mode' argument";
1289				return r;
1290			}
1291			rs->journal_dev.mode = r;
1292			continue;
1293		}
1294
1295		/*
1296		 * Parameters with number values from here on.
1297		 */
1298		if (kstrtoint(arg, 10, &value) < 0) {
1299			rs->ti->error = "Bad numerical argument given in raid params";
1300			return -EINVAL;
1301		}
1302
1303		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_REBUILD))) {
1304			/*
1305			 * "rebuild" is being passed in by userspace to provide
1306			 * indexes of replaced devices and to set up additional
1307			 * devices on raid level takeover.
1308			 */
1309			if (!__within_range(value, 0, rs->raid_disks - 1)) {
1310				rs->ti->error = "Invalid rebuild index given";
1311				return -EINVAL;
1312			}
1313
1314			if (test_and_set_bit(value, (void *) rs->rebuild_disks)) {
1315				rs->ti->error = "rebuild for this index already given";
1316				return -EINVAL;
1317			}
1318
1319			rd = rs->dev + value;
1320			clear_bit(In_sync, &rd->rdev.flags);
1321			clear_bit(Faulty, &rd->rdev.flags);
1322			rd->rdev.recovery_offset = 0;
1323			set_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags);
1324		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_WRITE_MOSTLY))) {
1325			if (!rt_is_raid1(rt)) {
1326				rs->ti->error = "write_mostly option is only valid for RAID1";
1327				return -EINVAL;
1328			}
1329
1330			if (!__within_range(value, 0, rs->md.raid_disks - 1)) {
1331				rs->ti->error = "Invalid write_mostly index given";
1332				return -EINVAL;
1333			}
1334
1335			write_mostly++;
1336			set_bit(WriteMostly, &rs->dev[value].rdev.flags);
1337			set_bit(__CTR_FLAG_WRITE_MOSTLY, &rs->ctr_flags);
1338		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_MAX_WRITE_BEHIND))) {
1339			if (!rt_is_raid1(rt)) {
1340				rs->ti->error = "max_write_behind option is only valid for RAID1";
1341				return -EINVAL;
1342			}
1343
1344			if (test_and_set_bit(__CTR_FLAG_MAX_WRITE_BEHIND, &rs->ctr_flags)) {
1345				rs->ti->error = "Only one max_write_behind argument pair allowed";
1346				return -EINVAL;
1347			}
1348
1349			/*
1350			 * In device-mapper, we specify things in sectors, but
1351			 * MD records this value in kB
1352			 */
1353			if (value < 0 || value / 2 > COUNTER_MAX) {
1354				rs->ti->error = "Max write-behind limit out of range";
1355				return -EINVAL;
1356			}
1357
1358			rs->md.bitmap_info.max_write_behind = value / 2;
1359		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_DAEMON_SLEEP))) {
1360			if (test_and_set_bit(__CTR_FLAG_DAEMON_SLEEP, &rs->ctr_flags)) {
1361				rs->ti->error = "Only one daemon_sleep argument pair allowed";
1362				return -EINVAL;
1363			}
1364			if (value < 0) {
1365				rs->ti->error = "daemon sleep period out of range";
1366				return -EINVAL;
1367			}
1368			rs->md.bitmap_info.daemon_sleep = value;
1369		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_DATA_OFFSET))) {
1370			/* Userspace passes new data_offset after having extended the the data image LV */
1371			if (test_and_set_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags)) {
1372				rs->ti->error = "Only one data_offset argument pair allowed";
1373				return -EINVAL;
1374			}
1375			/* Ensure sensible data offset */
1376			if (value < 0 ||
1377			    (value && (value < MIN_FREE_RESHAPE_SPACE || value % to_sector(PAGE_SIZE)))) {
1378				rs->ti->error = "Bogus data_offset value";
1379				return -EINVAL;
1380			}
1381			rs->data_offset = value;
1382		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_DELTA_DISKS))) {
1383			/* Define the +/-# of disks to add to/remove from the given raid set */
1384			if (test_and_set_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags)) {
1385				rs->ti->error = "Only one delta_disks argument pair allowed";
1386				return -EINVAL;
1387			}
1388			/* Ensure MAX_RAID_DEVICES and raid type minimal_devs! */
1389			if (!__within_range(abs(value), 1, MAX_RAID_DEVICES - rt->minimal_devs)) {
1390				rs->ti->error = "Too many delta_disk requested";
1391				return -EINVAL;
1392			}
1393
1394			rs->delta_disks = value;
1395		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_STRIPE_CACHE))) {
1396			if (test_and_set_bit(__CTR_FLAG_STRIPE_CACHE, &rs->ctr_flags)) {
1397				rs->ti->error = "Only one stripe_cache argument pair allowed";
1398				return -EINVAL;
1399			}
1400
1401			if (!rt_is_raid456(rt)) {
1402				rs->ti->error = "Inappropriate argument: stripe_cache";
1403				return -EINVAL;
1404			}
1405
1406			if (value < 0) {
1407				rs->ti->error = "Bogus stripe cache entries value";
1408				return -EINVAL;
1409			}
1410			rs->stripe_cache_entries = value;
1411		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_MIN_RECOVERY_RATE))) {
1412			if (test_and_set_bit(__CTR_FLAG_MIN_RECOVERY_RATE, &rs->ctr_flags)) {
1413				rs->ti->error = "Only one min_recovery_rate argument pair allowed";
1414				return -EINVAL;
1415			}
1416
1417			if (value < 0) {
1418				rs->ti->error = "min_recovery_rate out of range";
1419				return -EINVAL;
1420			}
1421			rs->md.sync_speed_min = value;
1422		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_MAX_RECOVERY_RATE))) {
1423			if (test_and_set_bit(__CTR_FLAG_MAX_RECOVERY_RATE, &rs->ctr_flags)) {
1424				rs->ti->error = "Only one max_recovery_rate argument pair allowed";
1425				return -EINVAL;
1426			}
1427
1428			if (value < 0) {
1429				rs->ti->error = "max_recovery_rate out of range";
1430				return -EINVAL;
1431			}
1432			rs->md.sync_speed_max = value;
1433		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_REGION_SIZE))) {
1434			if (test_and_set_bit(__CTR_FLAG_REGION_SIZE, &rs->ctr_flags)) {
1435				rs->ti->error = "Only one region_size argument pair allowed";
1436				return -EINVAL;
1437			}
1438
1439			region_size = value;
1440			rs->requested_bitmap_chunk_sectors = value;
1441		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_COPIES))) {
1442			if (test_and_set_bit(__CTR_FLAG_RAID10_COPIES, &rs->ctr_flags)) {
1443				rs->ti->error = "Only one raid10_copies argument pair allowed";
1444				return -EINVAL;
1445			}
1446
1447			if (!__within_range(value, 2, rs->md.raid_disks)) {
1448				rs->ti->error = "Bad value for 'raid10_copies'";
1449				return -EINVAL;
1450			}
1451
1452			raid10_copies = value;
1453		} else {
1454			DMERR("Unable to parse RAID parameter: %s", key);
1455			rs->ti->error = "Unable to parse RAID parameter";
1456			return -EINVAL;
1457		}
1458	}
1459
1460	if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags) &&
1461	    test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
1462		rs->ti->error = "sync and nosync are mutually exclusive";
1463		return -EINVAL;
1464	}
1465
1466	if (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags) &&
1467	    (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags) ||
1468	     test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))) {
1469		rs->ti->error = "sync/nosync and rebuild are mutually exclusive";
1470		return -EINVAL;
1471	}
1472
1473	if (write_mostly >= rs->md.raid_disks) {
1474		rs->ti->error = "Can't set all raid1 devices to write_mostly";
1475		return -EINVAL;
1476	}
1477
1478	if (rs->md.sync_speed_max &&
1479	    rs->md.sync_speed_min > rs->md.sync_speed_max) {
1480		rs->ti->error = "Bogus recovery rates";
1481		return -EINVAL;
1482	}
1483
1484	if (validate_region_size(rs, region_size))
1485		return -EINVAL;
1486
1487	if (rs->md.chunk_sectors)
1488		max_io_len = rs->md.chunk_sectors;
1489	else
1490		max_io_len = region_size;
1491
1492	if (dm_set_target_max_io_len(rs->ti, max_io_len))
1493		return -EINVAL;
1494
1495	if (rt_is_raid10(rt)) {
1496		if (raid10_copies > rs->md.raid_disks) {
1497			rs->ti->error = "Not enough devices to satisfy specification";
1498			return -EINVAL;
1499		}
1500
1501		rs->md.new_layout = raid10_format_to_md_layout(rs, raid10_format, raid10_copies);
1502		if (rs->md.new_layout < 0) {
1503			rs->ti->error = "Error getting raid10 format";
1504			return rs->md.new_layout;
1505		}
1506
1507		rt = get_raid_type_by_ll(10, rs->md.new_layout);
1508		if (!rt) {
1509			rs->ti->error = "Failed to recognize new raid10 layout";
1510			return -EINVAL;
1511		}
1512
1513		if ((rt->algorithm == ALGORITHM_RAID10_DEFAULT ||
1514		     rt->algorithm == ALGORITHM_RAID10_NEAR) &&
1515		    test_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags)) {
1516			rs->ti->error = "RAID10 format 'near' and 'raid10_use_near_sets' are incompatible";
1517			return -EINVAL;
1518		}
1519	}
1520
1521	rs->raid10_copies = raid10_copies;
1522
1523	/* Assume there are no metadata devices until the drives are parsed */
1524	rs->md.persistent = 0;
1525	rs->md.external = 1;
1526
1527	/* Check, if any invalid ctr arguments have been passed in for the raid level */
1528	return rs_check_for_valid_flags(rs);
1529}
1530
1531/* Set raid4/5/6 cache size */
1532static int rs_set_raid456_stripe_cache(struct raid_set *rs)
1533{
1534	int r;
1535	struct r5conf *conf;
1536	struct mddev *mddev = &rs->md;
1537	uint32_t min_stripes = max(mddev->chunk_sectors, mddev->new_chunk_sectors) / 2;
1538	uint32_t nr_stripes = rs->stripe_cache_entries;
1539
1540	if (!rt_is_raid456(rs->raid_type)) {
1541		rs->ti->error = "Inappropriate raid level; cannot change stripe_cache size";
1542		return -EINVAL;
1543	}
1544
1545	if (nr_stripes < min_stripes) {
1546		DMINFO("Adjusting requested %u stripe cache entries to %u to suit stripe size",
1547		       nr_stripes, min_stripes);
1548		nr_stripes = min_stripes;
1549	}
1550
1551	conf = mddev->private;
1552	if (!conf) {
1553		rs->ti->error = "Cannot change stripe_cache size on inactive RAID set";
1554		return -EINVAL;
1555	}
1556
1557	/* Try setting number of stripes in raid456 stripe cache */
1558	if (conf->min_nr_stripes != nr_stripes) {
1559		r = raid5_set_cache_size(mddev, nr_stripes);
1560		if (r) {
1561			rs->ti->error = "Failed to set raid4/5/6 stripe cache size";
1562			return r;
1563		}
1564
1565		DMINFO("%u stripe cache entries", nr_stripes);
1566	}
1567
1568	return 0;
1569}
1570
1571/* Return # of data stripes as kept in mddev as of @rs (i.e. as of superblock) */
1572static unsigned int mddev_data_stripes(struct raid_set *rs)
1573{
1574	return rs->md.raid_disks - rs->raid_type->parity_devs;
1575}
1576
1577/* Return # of data stripes of @rs (i.e. as of ctr) */
1578static unsigned int rs_data_stripes(struct raid_set *rs)
1579{
1580	return rs->raid_disks - rs->raid_type->parity_devs;
1581}
1582
1583/*
1584 * Retrieve rdev->sectors from any valid raid device of @rs
1585 * to allow userpace to pass in arbitray "- -" device tupples.
1586 */
1587static sector_t __rdev_sectors(struct raid_set *rs)
1588{
1589	int i;
1590
1591	for (i = 0; i < rs->md.raid_disks; i++) {
1592		struct md_rdev *rdev = &rs->dev[i].rdev;
1593
1594		if (!test_bit(Journal, &rdev->flags) &&
1595		    rdev->bdev && rdev->sectors)
1596			return rdev->sectors;
1597	}
1598
1599	return 0;
1600}
1601
1602/* Check that calculated dev_sectors fits all component devices. */
1603static int _check_data_dev_sectors(struct raid_set *rs)
1604{
1605	sector_t ds = ~0;
1606	struct md_rdev *rdev;
1607
1608	rdev_for_each(rdev, &rs->md)
1609		if (!test_bit(Journal, &rdev->flags) && rdev->bdev) {
1610			ds = min(ds, to_sector(i_size_read(rdev->bdev->bd_inode)));
1611			if (ds < rs->md.dev_sectors) {
1612				rs->ti->error = "Component device(s) too small";
1613				return -EINVAL;
1614			}
1615		}
1616
1617	return 0;
1618}
1619
1620/* Calculate the sectors per device and per array used for @rs */
1621static int rs_set_dev_and_array_sectors(struct raid_set *rs, sector_t sectors, bool use_mddev)
1622{
1623	int delta_disks;
1624	unsigned int data_stripes;
1625	sector_t array_sectors = sectors, dev_sectors = sectors;
1626	struct mddev *mddev = &rs->md;
1627
1628	if (use_mddev) {
1629		delta_disks = mddev->delta_disks;
1630		data_stripes = mddev_data_stripes(rs);
1631	} else {
1632		delta_disks = rs->delta_disks;
1633		data_stripes = rs_data_stripes(rs);
1634	}
1635
1636	/* Special raid1 case w/o delta_disks support (yet) */
1637	if (rt_is_raid1(rs->raid_type))
1638		;
1639	else if (rt_is_raid10(rs->raid_type)) {
1640		if (rs->raid10_copies < 2 ||
1641		    delta_disks < 0) {
1642			rs->ti->error = "Bogus raid10 data copies or delta disks";
1643			return -EINVAL;
1644		}
1645
1646		dev_sectors *= rs->raid10_copies;
1647		if (sector_div(dev_sectors, data_stripes))
1648			goto bad;
1649
1650		array_sectors = (data_stripes + delta_disks) * dev_sectors;
1651		if (sector_div(array_sectors, rs->raid10_copies))
1652			goto bad;
1653
1654	} else if (sector_div(dev_sectors, data_stripes))
1655		goto bad;
1656
1657	else
1658		/* Striped layouts */
1659		array_sectors = (data_stripes + delta_disks) * dev_sectors;
1660
1661	mddev->array_sectors = array_sectors;
1662	mddev->dev_sectors = dev_sectors;
1663	rs_set_rdev_sectors(rs);
1664
1665	return _check_data_dev_sectors(rs);
1666bad:
1667	rs->ti->error = "Target length not divisible by number of data devices";
1668	return -EINVAL;
1669}
1670
1671/* Setup recovery on @rs */
1672static void rs_setup_recovery(struct raid_set *rs, sector_t dev_sectors)
1673{
1674	/* raid0 does not recover */
1675	if (rs_is_raid0(rs))
1676		rs->md.recovery_cp = MaxSector;
1677	/*
1678	 * A raid6 set has to be recovered either
1679	 * completely or for the grown part to
1680	 * ensure proper parity and Q-Syndrome
1681	 */
1682	else if (rs_is_raid6(rs))
1683		rs->md.recovery_cp = dev_sectors;
1684	/*
1685	 * Other raid set types may skip recovery
1686	 * depending on the 'nosync' flag.
1687	 */
1688	else
1689		rs->md.recovery_cp = test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)
1690				     ? MaxSector : dev_sectors;
1691}
1692
1693static void do_table_event(struct work_struct *ws)
1694{
1695	struct raid_set *rs = container_of(ws, struct raid_set, md.event_work);
1696
1697	smp_rmb(); /* Make sure we access most actual mddev properties */
1698	if (!rs_is_reshaping(rs)) {
1699		if (rs_is_raid10(rs))
1700			rs_set_rdev_sectors(rs);
1701		rs_set_capacity(rs);
1702	}
1703	dm_table_event(rs->ti->table);
1704}
1705
1706/*
1707 * Make sure a valid takover (level switch) is being requested on @rs
1708 *
1709 * Conversions of raid sets from one MD personality to another
1710 * have to conform to restrictions which are enforced here.
1711 */
1712static int rs_check_takeover(struct raid_set *rs)
1713{
1714	struct mddev *mddev = &rs->md;
1715	unsigned int near_copies;
1716
1717	if (rs->md.degraded) {
1718		rs->ti->error = "Can't takeover degraded raid set";
1719		return -EPERM;
1720	}
1721
1722	if (rs_is_reshaping(rs)) {
1723		rs->ti->error = "Can't takeover reshaping raid set";
1724		return -EPERM;
1725	}
1726
1727	switch (mddev->level) {
1728	case 0:
1729		/* raid0 -> raid1/5 with one disk */
1730		if ((mddev->new_level == 1 || mddev->new_level == 5) &&
1731		    mddev->raid_disks == 1)
1732			return 0;
1733
1734		/* raid0 -> raid10 */
1735		if (mddev->new_level == 10 &&
1736		    !(rs->raid_disks % mddev->raid_disks))
1737			return 0;
1738
1739		/* raid0 with multiple disks -> raid4/5/6 */
1740		if (__within_range(mddev->new_level, 4, 6) &&
1741		    mddev->new_layout == ALGORITHM_PARITY_N &&
1742		    mddev->raid_disks > 1)
1743			return 0;
1744
1745		break;
1746
1747	case 10:
1748		/* Can't takeover raid10_offset! */
1749		if (__is_raid10_offset(mddev->layout))
1750			break;
1751
1752		near_copies = __raid10_near_copies(mddev->layout);
1753
1754		/* raid10* -> raid0 */
1755		if (mddev->new_level == 0) {
1756			/* Can takeover raid10_near with raid disks divisable by data copies! */
1757			if (near_copies > 1 &&
1758			    !(mddev->raid_disks % near_copies)) {
1759				mddev->raid_disks /= near_copies;
1760				mddev->delta_disks = mddev->raid_disks;
1761				return 0;
1762			}
1763
1764			/* Can takeover raid10_far */
1765			if (near_copies == 1 &&
1766			    __raid10_far_copies(mddev->layout) > 1)
1767				return 0;
1768
1769			break;
1770		}
1771
1772		/* raid10_{near,far} -> raid1 */
1773		if (mddev->new_level == 1 &&
1774		    max(near_copies, __raid10_far_copies(mddev->layout)) == mddev->raid_disks)
1775			return 0;
1776
1777		/* raid10_{near,far} with 2 disks -> raid4/5 */
1778		if (__within_range(mddev->new_level, 4, 5) &&
1779		    mddev->raid_disks == 2)
1780			return 0;
1781		break;
1782
1783	case 1:
1784		/* raid1 with 2 disks -> raid4/5 */
1785		if (__within_range(mddev->new_level, 4, 5) &&
1786		    mddev->raid_disks == 2) {
1787			mddev->degraded = 1;
1788			return 0;
1789		}
1790
1791		/* raid1 -> raid0 */
1792		if (mddev->new_level == 0 &&
1793		    mddev->raid_disks == 1)
1794			return 0;
1795
1796		/* raid1 -> raid10 */
1797		if (mddev->new_level == 10)
1798			return 0;
1799		break;
1800
1801	case 4:
1802		/* raid4 -> raid0 */
1803		if (mddev->new_level == 0)
1804			return 0;
1805
1806		/* raid4 -> raid1/5 with 2 disks */
1807		if ((mddev->new_level == 1 || mddev->new_level == 5) &&
1808		    mddev->raid_disks == 2)
1809			return 0;
1810
1811		/* raid4 -> raid5/6 with parity N */
1812		if (__within_range(mddev->new_level, 5, 6) &&
1813		    mddev->layout == ALGORITHM_PARITY_N)
1814			return 0;
1815		break;
1816
1817	case 5:
1818		/* raid5 with parity N -> raid0 */
1819		if (mddev->new_level == 0 &&
1820		    mddev->layout == ALGORITHM_PARITY_N)
1821			return 0;
1822
1823		/* raid5 with parity N -> raid4 */
1824		if (mddev->new_level == 4 &&
1825		    mddev->layout == ALGORITHM_PARITY_N)
1826			return 0;
1827
1828		/* raid5 with 2 disks -> raid1/4/10 */
1829		if ((mddev->new_level == 1 || mddev->new_level == 4 || mddev->new_level == 10) &&
1830		    mddev->raid_disks == 2)
1831			return 0;
1832
1833		/* raid5_* ->  raid6_*_6 with Q-Syndrome N (e.g. raid5_ra -> raid6_ra_6 */
1834		if (mddev->new_level == 6 &&
1835		    ((mddev->layout == ALGORITHM_PARITY_N && mddev->new_layout == ALGORITHM_PARITY_N) ||
1836		      __within_range(mddev->new_layout, ALGORITHM_LEFT_ASYMMETRIC_6, ALGORITHM_RIGHT_SYMMETRIC_6)))
1837			return 0;
1838		break;
1839
1840	case 6:
1841		/* raid6 with parity N -> raid0 */
1842		if (mddev->new_level == 0 &&
1843		    mddev->layout == ALGORITHM_PARITY_N)
1844			return 0;
1845
1846		/* raid6 with parity N -> raid4 */
1847		if (mddev->new_level == 4 &&
1848		    mddev->layout == ALGORITHM_PARITY_N)
1849			return 0;
1850
1851		/* raid6_*_n with Q-Syndrome N -> raid5_* */
1852		if (mddev->new_level == 5 &&
1853		    ((mddev->layout == ALGORITHM_PARITY_N && mddev->new_layout == ALGORITHM_PARITY_N) ||
1854		     __within_range(mddev->new_layout, ALGORITHM_LEFT_ASYMMETRIC, ALGORITHM_RIGHT_SYMMETRIC)))
1855			return 0;
1856		break;
1857
1858	default:
1859		break;
1860	}
1861
1862	rs->ti->error = "takeover not possible";
1863	return -EINVAL;
1864}
1865
1866/* True if @rs requested to be taken over */
1867static bool rs_takeover_requested(struct raid_set *rs)
1868{
1869	return rs->md.new_level != rs->md.level;
1870}
1871
1872/* True if layout is set to reshape. */
1873static bool rs_is_layout_change(struct raid_set *rs, bool use_mddev)
1874{
1875	return (use_mddev ? rs->md.delta_disks : rs->delta_disks) ||
1876	       rs->md.new_layout != rs->md.layout ||
1877	       rs->md.new_chunk_sectors != rs->md.chunk_sectors;
1878}
1879
1880/* True if @rs is requested to reshape by ctr */
1881static bool rs_reshape_requested(struct raid_set *rs)
1882{
1883	bool change;
1884	struct mddev *mddev = &rs->md;
1885
1886	if (rs_takeover_requested(rs))
1887		return false;
1888
1889	if (rs_is_raid0(rs))
1890		return false;
1891
1892	change = rs_is_layout_change(rs, false);
 
 
1893
1894	/* Historical case to support raid1 reshape without delta disks */
1895	if (rs_is_raid1(rs)) {
1896		if (rs->delta_disks)
1897			return !!rs->delta_disks;
1898
1899		return !change &&
1900		       mddev->raid_disks != rs->raid_disks;
1901	}
1902
1903	if (rs_is_raid10(rs))
1904		return change &&
1905		       !__is_raid10_far(mddev->new_layout) &&
1906		       rs->delta_disks >= 0;
1907
1908	return change;
1909}
1910
1911/*  Features */
1912#define	FEATURE_FLAG_SUPPORTS_V190	0x1 /* Supports extended superblock */
1913
1914/* State flags for sb->flags */
1915#define	SB_FLAG_RESHAPE_ACTIVE		0x1
1916#define	SB_FLAG_RESHAPE_BACKWARDS	0x2
1917
1918/*
1919 * This structure is never routinely used by userspace, unlike md superblocks.
1920 * Devices with this superblock should only ever be accessed via device-mapper.
1921 */
1922#define DM_RAID_MAGIC 0x64526D44
1923struct dm_raid_superblock {
1924	__le32 magic;		/* "DmRd" */
1925	__le32 compat_features;	/* Used to indicate compatible features (like 1.9.0 ondisk metadata extension) */
1926
1927	__le32 num_devices;	/* Number of devices in this raid set. (Max 64) */
1928	__le32 array_position;	/* The position of this drive in the raid set */
1929
1930	__le64 events;		/* Incremented by md when superblock updated */
1931	__le64 failed_devices;	/* Pre 1.9.0 part of bit field of devices to */
1932				/* indicate failures (see extension below) */
1933
1934	/*
1935	 * This offset tracks the progress of the repair or replacement of
1936	 * an individual drive.
1937	 */
1938	__le64 disk_recovery_offset;
1939
1940	/*
1941	 * This offset tracks the progress of the initial raid set
1942	 * synchronisation/parity calculation.
1943	 */
1944	__le64 array_resync_offset;
1945
1946	/*
1947	 * raid characteristics
1948	 */
1949	__le32 level;
1950	__le32 layout;
1951	__le32 stripe_sectors;
1952
1953	/********************************************************************
1954	 * BELOW FOLLOW V1.9.0 EXTENSIONS TO THE PRISTINE SUPERBLOCK FORMAT!!!
1955	 *
1956	 * FEATURE_FLAG_SUPPORTS_V190 in the compat_features member indicates that those exist
1957	 */
1958
1959	__le32 flags; /* Flags defining array states for reshaping */
1960
1961	/*
1962	 * This offset tracks the progress of a raid
1963	 * set reshape in order to be able to restart it
1964	 */
1965	__le64 reshape_position;
1966
1967	/*
1968	 * These define the properties of the array in case of an interrupted reshape
1969	 */
1970	__le32 new_level;
1971	__le32 new_layout;
1972	__le32 new_stripe_sectors;
1973	__le32 delta_disks;
1974
1975	__le64 array_sectors; /* Array size in sectors */
1976
1977	/*
1978	 * Sector offsets to data on devices (reshaping).
1979	 * Needed to support out of place reshaping, thus
1980	 * not writing over any stripes whilst converting
1981	 * them from old to new layout
1982	 */
1983	__le64 data_offset;
1984	__le64 new_data_offset;
1985
1986	__le64 sectors; /* Used device size in sectors */
1987
1988	/*
1989	 * Additonal Bit field of devices indicating failures to support
1990	 * up to 256 devices with the 1.9.0 on-disk metadata format
1991	 */
1992	__le64 extended_failed_devices[DISKS_ARRAY_ELEMS - 1];
1993
1994	__le32 incompat_features;	/* Used to indicate any incompatible features */
1995
1996	/* Always set rest up to logical block size to 0 when writing (see get_metadata_device() below). */
1997} __packed;
1998
1999/*
2000 * Check for reshape constraints on raid set @rs:
2001 *
2002 * - reshape function non-existent
2003 * - degraded set
2004 * - ongoing recovery
2005 * - ongoing reshape
2006 *
2007 * Returns 0 if none or -EPERM if given constraint
2008 * and error message reference in @errmsg
2009 */
2010static int rs_check_reshape(struct raid_set *rs)
2011{
2012	struct mddev *mddev = &rs->md;
2013
2014	if (!mddev->pers || !mddev->pers->check_reshape)
2015		rs->ti->error = "Reshape not supported";
2016	else if (mddev->degraded)
2017		rs->ti->error = "Can't reshape degraded raid set";
2018	else if (rs_is_recovering(rs))
2019		rs->ti->error = "Convert request on recovering raid set prohibited";
2020	else if (rs_is_reshaping(rs))
2021		rs->ti->error = "raid set already reshaping!";
2022	else if (!(rs_is_raid1(rs) || rs_is_raid10(rs) || rs_is_raid456(rs)))
2023		rs->ti->error = "Reshaping only supported for raid1/4/5/6/10";
2024	else
2025		return 0;
2026
2027	return -EPERM;
2028}
2029
2030static int read_disk_sb(struct md_rdev *rdev, int size, bool force_reload)
2031{
2032	BUG_ON(!rdev->sb_page);
2033
2034	if (rdev->sb_loaded && !force_reload)
2035		return 0;
2036
2037	rdev->sb_loaded = 0;
2038
2039	if (!sync_page_io(rdev, 0, size, rdev->sb_page, REQ_OP_READ, 0, true)) {
2040		DMERR("Failed to read superblock of device at position %d",
2041		      rdev->raid_disk);
2042		md_error(rdev->mddev, rdev);
2043		set_bit(Faulty, &rdev->flags);
2044		return -EIO;
2045	}
2046
2047	rdev->sb_loaded = 1;
2048
2049	return 0;
2050}
2051
2052static void sb_retrieve_failed_devices(struct dm_raid_superblock *sb, uint64_t *failed_devices)
2053{
2054	failed_devices[0] = le64_to_cpu(sb->failed_devices);
2055	memset(failed_devices + 1, 0, sizeof(sb->extended_failed_devices));
2056
2057	if (le32_to_cpu(sb->compat_features) & FEATURE_FLAG_SUPPORTS_V190) {
2058		int i = ARRAY_SIZE(sb->extended_failed_devices);
2059
2060		while (i--)
2061			failed_devices[i+1] = le64_to_cpu(sb->extended_failed_devices[i]);
2062	}
2063}
2064
2065static void sb_update_failed_devices(struct dm_raid_superblock *sb, uint64_t *failed_devices)
2066{
2067	int i = ARRAY_SIZE(sb->extended_failed_devices);
2068
2069	sb->failed_devices = cpu_to_le64(failed_devices[0]);
2070	while (i--)
2071		sb->extended_failed_devices[i] = cpu_to_le64(failed_devices[i+1]);
2072}
2073
2074/*
2075 * Synchronize the superblock members with the raid set properties
2076 *
2077 * All superblock data is little endian.
2078 */
2079static void super_sync(struct mddev *mddev, struct md_rdev *rdev)
2080{
2081	bool update_failed_devices = false;
2082	unsigned int i;
2083	uint64_t failed_devices[DISKS_ARRAY_ELEMS];
2084	struct dm_raid_superblock *sb;
2085	struct raid_set *rs = container_of(mddev, struct raid_set, md);
2086
2087	/* No metadata device, no superblock */
2088	if (!rdev->meta_bdev)
2089		return;
2090
2091	BUG_ON(!rdev->sb_page);
2092
2093	sb = page_address(rdev->sb_page);
2094
2095	sb_retrieve_failed_devices(sb, failed_devices);
2096
2097	for (i = 0; i < rs->raid_disks; i++)
2098		if (!rs->dev[i].data_dev || test_bit(Faulty, &rs->dev[i].rdev.flags)) {
2099			update_failed_devices = true;
2100			set_bit(i, (void *) failed_devices);
2101		}
2102
2103	if (update_failed_devices)
2104		sb_update_failed_devices(sb, failed_devices);
2105
2106	sb->magic = cpu_to_le32(DM_RAID_MAGIC);
2107	sb->compat_features = cpu_to_le32(FEATURE_FLAG_SUPPORTS_V190);
2108
2109	sb->num_devices = cpu_to_le32(mddev->raid_disks);
2110	sb->array_position = cpu_to_le32(rdev->raid_disk);
2111
2112	sb->events = cpu_to_le64(mddev->events);
2113
2114	sb->disk_recovery_offset = cpu_to_le64(rdev->recovery_offset);
2115	sb->array_resync_offset = cpu_to_le64(mddev->recovery_cp);
2116
2117	sb->level = cpu_to_le32(mddev->level);
2118	sb->layout = cpu_to_le32(mddev->layout);
2119	sb->stripe_sectors = cpu_to_le32(mddev->chunk_sectors);
2120
2121	/********************************************************************
2122	 * BELOW FOLLOW V1.9.0 EXTENSIONS TO THE PRISTINE SUPERBLOCK FORMAT!!!
2123	 *
2124	 * FEATURE_FLAG_SUPPORTS_V190 in the compat_features member indicates that those exist
2125	 */
2126	sb->new_level = cpu_to_le32(mddev->new_level);
2127	sb->new_layout = cpu_to_le32(mddev->new_layout);
2128	sb->new_stripe_sectors = cpu_to_le32(mddev->new_chunk_sectors);
2129
2130	sb->delta_disks = cpu_to_le32(mddev->delta_disks);
2131
2132	smp_rmb(); /* Make sure we access most recent reshape position */
2133	sb->reshape_position = cpu_to_le64(mddev->reshape_position);
2134	if (le64_to_cpu(sb->reshape_position) != MaxSector) {
2135		/* Flag ongoing reshape */
2136		sb->flags |= cpu_to_le32(SB_FLAG_RESHAPE_ACTIVE);
2137
2138		if (mddev->delta_disks < 0 || mddev->reshape_backwards)
2139			sb->flags |= cpu_to_le32(SB_FLAG_RESHAPE_BACKWARDS);
2140	} else {
2141		/* Clear reshape flags */
2142		sb->flags &= ~(cpu_to_le32(SB_FLAG_RESHAPE_ACTIVE|SB_FLAG_RESHAPE_BACKWARDS));
2143	}
2144
2145	sb->array_sectors = cpu_to_le64(mddev->array_sectors);
2146	sb->data_offset = cpu_to_le64(rdev->data_offset);
2147	sb->new_data_offset = cpu_to_le64(rdev->new_data_offset);
2148	sb->sectors = cpu_to_le64(rdev->sectors);
2149	sb->incompat_features = cpu_to_le32(0);
2150
2151	/* Zero out the rest of the payload after the size of the superblock */
2152	memset(sb + 1, 0, rdev->sb_size - sizeof(*sb));
2153}
2154
2155/*
2156 * super_load
2157 *
2158 * This function creates a superblock if one is not found on the device
2159 * and will decide which superblock to use if there's a choice.
2160 *
2161 * Return: 1 if use rdev, 0 if use refdev, -Exxx otherwise
2162 */
2163static int super_load(struct md_rdev *rdev, struct md_rdev *refdev)
2164{
2165	int r;
2166	struct dm_raid_superblock *sb;
2167	struct dm_raid_superblock *refsb;
2168	uint64_t events_sb, events_refsb;
2169
2170	r = read_disk_sb(rdev, rdev->sb_size, false);
2171	if (r)
2172		return r;
2173
2174	sb = page_address(rdev->sb_page);
2175
2176	/*
2177	 * Two cases that we want to write new superblocks and rebuild:
2178	 * 1) New device (no matching magic number)
2179	 * 2) Device specified for rebuild (!In_sync w/ offset == 0)
2180	 */
2181	if ((sb->magic != cpu_to_le32(DM_RAID_MAGIC)) ||
2182	    (!test_bit(In_sync, &rdev->flags) && !rdev->recovery_offset)) {
2183		super_sync(rdev->mddev, rdev);
2184
2185		set_bit(FirstUse, &rdev->flags);
2186		sb->compat_features = cpu_to_le32(FEATURE_FLAG_SUPPORTS_V190);
2187
2188		/* Force writing of superblocks to disk */
2189		set_bit(MD_SB_CHANGE_DEVS, &rdev->mddev->sb_flags);
2190
2191		/* Any superblock is better than none, choose that if given */
2192		return refdev ? 0 : 1;
2193	}
2194
2195	if (!refdev)
2196		return 1;
2197
2198	events_sb = le64_to_cpu(sb->events);
2199
2200	refsb = page_address(refdev->sb_page);
2201	events_refsb = le64_to_cpu(refsb->events);
2202
2203	return (events_sb > events_refsb) ? 1 : 0;
2204}
2205
2206static int super_init_validation(struct raid_set *rs, struct md_rdev *rdev)
2207{
2208	int role;
2209	unsigned int d;
2210	struct mddev *mddev = &rs->md;
2211	uint64_t events_sb;
2212	uint64_t failed_devices[DISKS_ARRAY_ELEMS];
2213	struct dm_raid_superblock *sb;
2214	uint32_t new_devs = 0, rebuild_and_new = 0, rebuilds = 0;
2215	struct md_rdev *r;
2216	struct dm_raid_superblock *sb2;
2217
2218	sb = page_address(rdev->sb_page);
2219	events_sb = le64_to_cpu(sb->events);
2220
2221	/*
2222	 * Initialise to 1 if this is a new superblock.
2223	 */
2224	mddev->events = events_sb ? : 1;
2225
2226	mddev->reshape_position = MaxSector;
2227
2228	mddev->raid_disks = le32_to_cpu(sb->num_devices);
2229	mddev->level = le32_to_cpu(sb->level);
2230	mddev->layout = le32_to_cpu(sb->layout);
2231	mddev->chunk_sectors = le32_to_cpu(sb->stripe_sectors);
2232
2233	/*
2234	 * Reshaping is supported, e.g. reshape_position is valid
2235	 * in superblock and superblock content is authoritative.
2236	 */
2237	if (le32_to_cpu(sb->compat_features) & FEATURE_FLAG_SUPPORTS_V190) {
2238		/* Superblock is authoritative wrt given raid set layout! */
2239		mddev->new_level = le32_to_cpu(sb->new_level);
2240		mddev->new_layout = le32_to_cpu(sb->new_layout);
2241		mddev->new_chunk_sectors = le32_to_cpu(sb->new_stripe_sectors);
2242		mddev->delta_disks = le32_to_cpu(sb->delta_disks);
2243		mddev->array_sectors = le64_to_cpu(sb->array_sectors);
2244
2245		/* raid was reshaping and got interrupted */
2246		if (le32_to_cpu(sb->flags) & SB_FLAG_RESHAPE_ACTIVE) {
2247			if (test_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags)) {
2248				DMERR("Reshape requested but raid set is still reshaping");
2249				return -EINVAL;
2250			}
2251
2252			if (mddev->delta_disks < 0 ||
2253			    (!mddev->delta_disks && (le32_to_cpu(sb->flags) & SB_FLAG_RESHAPE_BACKWARDS)))
2254				mddev->reshape_backwards = 1;
2255			else
2256				mddev->reshape_backwards = 0;
2257
2258			mddev->reshape_position = le64_to_cpu(sb->reshape_position);
2259			rs->raid_type = get_raid_type_by_ll(mddev->level, mddev->layout);
2260		}
2261
2262	} else {
2263		/*
2264		 * No takeover/reshaping, because we don't have the extended v1.9.0 metadata
2265		 */
2266		struct raid_type *rt_cur = get_raid_type_by_ll(mddev->level, mddev->layout);
2267		struct raid_type *rt_new = get_raid_type_by_ll(mddev->new_level, mddev->new_layout);
2268
2269		if (rs_takeover_requested(rs)) {
2270			if (rt_cur && rt_new)
2271				DMERR("Takeover raid sets from %s to %s not yet supported by metadata. (raid level change)",
2272				      rt_cur->name, rt_new->name);
2273			else
2274				DMERR("Takeover raid sets not yet supported by metadata. (raid level change)");
2275			return -EINVAL;
2276		} else if (rs_reshape_requested(rs)) {
2277			DMERR("Reshaping raid sets not yet supported by metadata. (raid layout change keeping level)");
2278			if (mddev->layout != mddev->new_layout) {
2279				if (rt_cur && rt_new)
2280					DMERR("	 current layout %s vs new layout %s",
2281					      rt_cur->name, rt_new->name);
2282				else
2283					DMERR("	 current layout 0x%X vs new layout 0x%X",
2284					      le32_to_cpu(sb->layout), mddev->new_layout);
2285			}
2286			if (mddev->chunk_sectors != mddev->new_chunk_sectors)
2287				DMERR("	 current stripe sectors %u vs new stripe sectors %u",
2288				      mddev->chunk_sectors, mddev->new_chunk_sectors);
2289			if (rs->delta_disks)
2290				DMERR("	 current %u disks vs new %u disks",
2291				      mddev->raid_disks, mddev->raid_disks + rs->delta_disks);
2292			if (rs_is_raid10(rs)) {
2293				DMERR("	 Old layout: %s w/ %u copies",
2294				      raid10_md_layout_to_format(mddev->layout),
2295				      raid10_md_layout_to_copies(mddev->layout));
2296				DMERR("	 New layout: %s w/ %u copies",
2297				      raid10_md_layout_to_format(mddev->new_layout),
2298				      raid10_md_layout_to_copies(mddev->new_layout));
2299			}
2300			return -EINVAL;
2301		}
2302
2303		DMINFO("Discovered old metadata format; upgrading to extended metadata format");
2304	}
2305
2306	if (!test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))
2307		mddev->recovery_cp = le64_to_cpu(sb->array_resync_offset);
2308
2309	/*
2310	 * During load, we set FirstUse if a new superblock was written.
2311	 * There are two reasons we might not have a superblock:
2312	 * 1) The raid set is brand new - in which case, all of the
2313	 *    devices must have their In_sync bit set.	Also,
2314	 *    recovery_cp must be 0, unless forced.
2315	 * 2) This is a new device being added to an old raid set
2316	 *    and the new device needs to be rebuilt - in which
2317	 *    case the In_sync bit will /not/ be set and
2318	 *    recovery_cp must be MaxSector.
2319	 * 3) This is/are a new device(s) being added to an old
2320	 *    raid set during takeover to a higher raid level
2321	 *    to provide capacity for redundancy or during reshape
2322	 *    to add capacity to grow the raid set.
2323	 */
2324	d = 0;
2325	rdev_for_each(r, mddev) {
2326		if (test_bit(Journal, &rdev->flags))
2327			continue;
2328
2329		if (test_bit(FirstUse, &r->flags))
2330			new_devs++;
2331
2332		if (!test_bit(In_sync, &r->flags)) {
2333			DMINFO("Device %d specified for rebuild; clearing superblock",
2334				r->raid_disk);
2335			rebuilds++;
2336
2337			if (test_bit(FirstUse, &r->flags))
2338				rebuild_and_new++;
2339		}
2340
2341		d++;
2342	}
2343
2344	if (new_devs == rs->raid_disks || !rebuilds) {
2345		/* Replace a broken device */
2346		if (new_devs == rs->raid_disks) {
2347			DMINFO("Superblocks created for new raid set");
2348			set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
2349		} else if (new_devs != rebuilds &&
2350			   new_devs != rs->delta_disks) {
2351			DMERR("New device injected into existing raid set without "
2352			      "'delta_disks' or 'rebuild' parameter specified");
2353			return -EINVAL;
2354		}
2355	} else if (new_devs && new_devs != rebuilds) {
2356		DMERR("%u 'rebuild' devices cannot be injected into"
2357		      " a raid set with %u other first-time devices",
2358		      rebuilds, new_devs);
2359		return -EINVAL;
2360	} else if (rebuilds) {
2361		if (rebuild_and_new && rebuilds != rebuild_and_new) {
2362			DMERR("new device%s provided without 'rebuild'",
2363			      new_devs > 1 ? "s" : "");
2364			return -EINVAL;
2365		} else if (!test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags) && rs_is_recovering(rs)) {
2366			DMERR("'rebuild' specified while raid set is not in-sync (recovery_cp=%llu)",
2367			      (unsigned long long) mddev->recovery_cp);
2368			return -EINVAL;
2369		} else if (rs_is_reshaping(rs)) {
2370			DMERR("'rebuild' specified while raid set is being reshaped (reshape_position=%llu)",
2371			      (unsigned long long) mddev->reshape_position);
2372			return -EINVAL;
2373		}
2374	}
2375
2376	/*
2377	 * Now we set the Faulty bit for those devices that are
2378	 * recorded in the superblock as failed.
2379	 */
2380	sb_retrieve_failed_devices(sb, failed_devices);
2381	rdev_for_each(r, mddev) {
2382		if (test_bit(Journal, &rdev->flags) ||
2383		    !r->sb_page)
2384			continue;
2385		sb2 = page_address(r->sb_page);
2386		sb2->failed_devices = 0;
2387		memset(sb2->extended_failed_devices, 0, sizeof(sb2->extended_failed_devices));
2388
2389		/*
2390		 * Check for any device re-ordering.
2391		 */
2392		if (!test_bit(FirstUse, &r->flags) && (r->raid_disk >= 0)) {
2393			role = le32_to_cpu(sb2->array_position);
2394			if (role < 0)
2395				continue;
2396
2397			if (role != r->raid_disk) {
2398				if (rs_is_raid10(rs) && __is_raid10_near(mddev->layout)) {
2399					if (mddev->raid_disks % __raid10_near_copies(mddev->layout) ||
2400					    rs->raid_disks % rs->raid10_copies) {
2401						rs->ti->error =
2402							"Cannot change raid10 near set to odd # of devices!";
2403						return -EINVAL;
2404					}
2405
2406					sb2->array_position = cpu_to_le32(r->raid_disk);
2407
2408				} else if (!(rs_is_raid10(rs) && rt_is_raid0(rs->raid_type)) &&
2409					   !(rs_is_raid0(rs) && rt_is_raid10(rs->raid_type)) &&
2410					   !rt_is_raid1(rs->raid_type)) {
2411					rs->ti->error = "Cannot change device positions in raid set";
2412					return -EINVAL;
2413				}
2414
2415				DMINFO("raid device #%d now at position #%d", role, r->raid_disk);
2416			}
2417
2418			/*
2419			 * Partial recovery is performed on
2420			 * returning failed devices.
2421			 */
2422			if (test_bit(role, (void *) failed_devices))
2423				set_bit(Faulty, &r->flags);
2424		}
2425	}
2426
2427	return 0;
2428}
2429
2430static int super_validate(struct raid_set *rs, struct md_rdev *rdev)
2431{
2432	struct mddev *mddev = &rs->md;
2433	struct dm_raid_superblock *sb;
2434
2435	if (rs_is_raid0(rs) || !rdev->sb_page || rdev->raid_disk < 0)
2436		return 0;
2437
2438	sb = page_address(rdev->sb_page);
2439
2440	/*
2441	 * If mddev->events is not set, we know we have not yet initialized
2442	 * the array.
2443	 */
2444	if (!mddev->events && super_init_validation(rs, rdev))
2445		return -EINVAL;
2446
2447	if (le32_to_cpu(sb->compat_features) &&
2448	    le32_to_cpu(sb->compat_features) != FEATURE_FLAG_SUPPORTS_V190) {
2449		rs->ti->error = "Unable to assemble array: Unknown flag(s) in compatible feature flags";
2450		return -EINVAL;
2451	}
2452
2453	if (sb->incompat_features) {
2454		rs->ti->error = "Unable to assemble array: No incompatible feature flags supported yet";
2455		return -EINVAL;
2456	}
2457
2458	/* Enable bitmap creation on @rs unless no metadevs or raid0 or journaled raid4/5/6 set. */
2459	mddev->bitmap_info.offset = (rt_is_raid0(rs->raid_type) || rs->journal_dev.dev) ? 0 : to_sector(4096);
2460	mddev->bitmap_info.default_offset = mddev->bitmap_info.offset;
2461
2462	if (!test_and_clear_bit(FirstUse, &rdev->flags)) {
2463		/*
2464		 * Retrieve rdev size stored in superblock to be prepared for shrink.
2465		 * Check extended superblock members are present otherwise the size
2466		 * will not be set!
2467		 */
2468		if (le32_to_cpu(sb->compat_features) & FEATURE_FLAG_SUPPORTS_V190)
2469			rdev->sectors = le64_to_cpu(sb->sectors);
2470
2471		rdev->recovery_offset = le64_to_cpu(sb->disk_recovery_offset);
2472		if (rdev->recovery_offset == MaxSector)
2473			set_bit(In_sync, &rdev->flags);
2474		/*
2475		 * If no reshape in progress -> we're recovering single
2476		 * disk(s) and have to set the device(s) to out-of-sync
2477		 */
2478		else if (!rs_is_reshaping(rs))
2479			clear_bit(In_sync, &rdev->flags); /* Mandatory for recovery */
2480	}
2481
2482	/*
2483	 * If a device comes back, set it as not In_sync and no longer faulty.
2484	 */
2485	if (test_and_clear_bit(Faulty, &rdev->flags)) {
2486		rdev->recovery_offset = 0;
2487		clear_bit(In_sync, &rdev->flags);
2488		rdev->saved_raid_disk = rdev->raid_disk;
2489	}
2490
2491	/* Reshape support -> restore repective data offsets */
2492	rdev->data_offset = le64_to_cpu(sb->data_offset);
2493	rdev->new_data_offset = le64_to_cpu(sb->new_data_offset);
2494
2495	return 0;
2496}
2497
2498/*
2499 * Analyse superblocks and select the freshest.
2500 */
2501static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
2502{
2503	int r;
2504	struct md_rdev *rdev, *freshest;
2505	struct mddev *mddev = &rs->md;
2506
2507	freshest = NULL;
2508	rdev_for_each(rdev, mddev) {
2509		if (test_bit(Journal, &rdev->flags))
2510			continue;
2511
2512		if (!rdev->meta_bdev)
2513			continue;
2514
2515		/* Set superblock offset/size for metadata device. */
2516		rdev->sb_start = 0;
2517		rdev->sb_size = bdev_logical_block_size(rdev->meta_bdev);
2518		if (rdev->sb_size < sizeof(struct dm_raid_superblock) || rdev->sb_size > PAGE_SIZE) {
2519			DMERR("superblock size of a logical block is no longer valid");
2520			return -EINVAL;
2521		}
2522
2523		/*
2524		 * Skipping super_load due to CTR_FLAG_SYNC will cause
2525		 * the array to undergo initialization again as
2526		 * though it were new.	This is the intended effect
2527		 * of the "sync" directive.
2528		 *
2529		 * With reshaping capability added, we must ensure that
2530		 * that the "sync" directive is disallowed during the reshape.
2531		 */
2532		if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags))
2533			continue;
2534
2535		r = super_load(rdev, freshest);
2536
2537		switch (r) {
2538		case 1:
2539			freshest = rdev;
2540			break;
2541		case 0:
2542			break;
2543		default:
2544			/* This is a failure to read the superblock from the metadata device. */
2545			/*
2546			 * We have to keep any raid0 data/metadata device pairs or
2547			 * the MD raid0 personality will fail to start the array.
2548			 */
2549			if (rs_is_raid0(rs))
2550				continue;
2551
2552			/*
2553			 * We keep the dm_devs to be able to emit the device tuple
2554			 * properly on the table line in raid_status() (rather than
2555			 * mistakenly acting as if '- -' got passed into the constructor).
2556			 *
2557			 * The rdev has to stay on the same_set list to allow for
2558			 * the attempt to restore faulty devices on second resume.
2559			 */
2560			rdev->raid_disk = rdev->saved_raid_disk = -1;
2561			break;
2562		}
2563	}
2564
2565	if (!freshest)
2566		return 0;
2567
2568	/*
2569	 * Validation of the freshest device provides the source of
2570	 * validation for the remaining devices.
2571	 */
2572	rs->ti->error = "Unable to assemble array: Invalid superblocks";
2573	if (super_validate(rs, freshest))
2574		return -EINVAL;
2575
2576	if (validate_raid_redundancy(rs)) {
2577		rs->ti->error = "Insufficient redundancy to activate array";
2578		return -EINVAL;
2579	}
2580
2581	rdev_for_each(rdev, mddev)
2582		if (!test_bit(Journal, &rdev->flags) &&
2583		    rdev != freshest &&
2584		    super_validate(rs, rdev))
2585			return -EINVAL;
2586	return 0;
2587}
2588
2589/*
2590 * Adjust data_offset and new_data_offset on all disk members of @rs
2591 * for out of place reshaping if requested by contructor
2592 *
2593 * We need free space at the beginning of each raid disk for forward
2594 * and at the end for backward reshapes which userspace has to provide
2595 * via remapping/reordering of space.
2596 */
2597static int rs_adjust_data_offsets(struct raid_set *rs)
2598{
2599	sector_t data_offset = 0, new_data_offset = 0;
2600	struct md_rdev *rdev;
2601
2602	/* Constructor did not request data offset change */
2603	if (!test_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags)) {
2604		if (!rs_is_reshapable(rs))
2605			goto out;
2606
2607		return 0;
2608	}
2609
2610	/* HM FIXME: get In_Sync raid_dev? */
2611	rdev = &rs->dev[0].rdev;
2612
2613	if (rs->delta_disks < 0) {
2614		/*
2615		 * Removing disks (reshaping backwards):
2616		 *
2617		 * - before reshape: data is at offset 0 and free space
2618		 *		     is at end of each component LV
2619		 *
2620		 * - after reshape: data is at offset rs->data_offset != 0 on each component LV
2621		 */
2622		data_offset = 0;
2623		new_data_offset = rs->data_offset;
2624
2625	} else if (rs->delta_disks > 0) {
2626		/*
2627		 * Adding disks (reshaping forwards):
2628		 *
2629		 * - before reshape: data is at offset rs->data_offset != 0 and
2630		 *		     free space is at begin of each component LV
2631		 *
2632		 * - after reshape: data is at offset 0 on each component LV
2633		 */
2634		data_offset = rs->data_offset;
2635		new_data_offset = 0;
2636
2637	} else {
2638		/*
2639		 * User space passes in 0 for data offset after having removed reshape space
2640		 *
2641		 * - or - (data offset != 0)
2642		 *
2643		 * Changing RAID layout or chunk size -> toggle offsets
2644		 *
2645		 * - before reshape: data is at offset rs->data_offset 0 and
2646		 *		     free space is at end of each component LV
2647		 *		     -or-
2648		 *                   data is at offset rs->data_offset != 0 and
2649		 *		     free space is at begin of each component LV
2650		 *
2651		 * - after reshape: data is at offset 0 if it was at offset != 0
2652		 *                  or at offset != 0 if it was at offset 0
2653		 *                  on each component LV
2654		 *
2655		 */
2656		data_offset = rs->data_offset ? rdev->data_offset : 0;
2657		new_data_offset = data_offset ? 0 : rs->data_offset;
2658		set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2659	}
2660
2661	/*
2662	 * Make sure we got a minimum amount of free sectors per device
2663	 */
2664	if (rs->data_offset &&
2665	    to_sector(i_size_read(rdev->bdev->bd_inode)) - rs->md.dev_sectors < MIN_FREE_RESHAPE_SPACE) {
2666		rs->ti->error = data_offset ? "No space for forward reshape" :
2667					      "No space for backward reshape";
2668		return -ENOSPC;
2669	}
2670out:
2671	/*
2672	 * Raise recovery_cp in case data_offset != 0 to
2673	 * avoid false recovery positives in the constructor.
2674	 */
2675	if (rs->md.recovery_cp < rs->md.dev_sectors)
2676		rs->md.recovery_cp += rs->dev[0].rdev.data_offset;
2677
2678	/* Adjust data offsets on all rdevs but on any raid4/5/6 journal device */
2679	rdev_for_each(rdev, &rs->md) {
2680		if (!test_bit(Journal, &rdev->flags)) {
2681			rdev->data_offset = data_offset;
2682			rdev->new_data_offset = new_data_offset;
2683		}
2684	}
2685
2686	return 0;
2687}
2688
2689/* Userpace reordered disks -> adjust raid_disk indexes in @rs */
2690static void __reorder_raid_disk_indexes(struct raid_set *rs)
2691{
2692	int i = 0;
2693	struct md_rdev *rdev;
2694
2695	rdev_for_each(rdev, &rs->md) {
2696		if (!test_bit(Journal, &rdev->flags)) {
2697			rdev->raid_disk = i++;
2698			rdev->saved_raid_disk = rdev->new_raid_disk = -1;
2699		}
2700	}
2701}
2702
2703/*
2704 * Setup @rs for takeover by a different raid level
2705 */
2706static int rs_setup_takeover(struct raid_set *rs)
2707{
2708	struct mddev *mddev = &rs->md;
2709	struct md_rdev *rdev;
2710	unsigned int d = mddev->raid_disks = rs->raid_disks;
2711	sector_t new_data_offset = rs->dev[0].rdev.data_offset ? 0 : rs->data_offset;
2712
2713	if (rt_is_raid10(rs->raid_type)) {
2714		if (rs_is_raid0(rs)) {
2715			/* Userpace reordered disks -> adjust raid_disk indexes */
2716			__reorder_raid_disk_indexes(rs);
2717
2718			/* raid0 -> raid10_far layout */
2719			mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_FAR,
2720								   rs->raid10_copies);
2721		} else if (rs_is_raid1(rs))
2722			/* raid1 -> raid10_near layout */
2723			mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_NEAR,
2724								   rs->raid_disks);
2725		else
2726			return -EINVAL;
2727
2728	}
2729
2730	clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
2731	mddev->recovery_cp = MaxSector;
2732
2733	while (d--) {
2734		rdev = &rs->dev[d].rdev;
2735
2736		if (test_bit(d, (void *) rs->rebuild_disks)) {
2737			clear_bit(In_sync, &rdev->flags);
2738			clear_bit(Faulty, &rdev->flags);
2739			mddev->recovery_cp = rdev->recovery_offset = 0;
2740			/* Bitmap has to be created when we do an "up" takeover */
2741			set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
2742		}
2743
2744		rdev->new_data_offset = new_data_offset;
2745	}
2746
2747	return 0;
2748}
2749
2750/* Prepare @rs for reshape */
2751static int rs_prepare_reshape(struct raid_set *rs)
2752{
2753	bool reshape;
2754	struct mddev *mddev = &rs->md;
2755
2756	if (rs_is_raid10(rs)) {
2757		if (rs->raid_disks != mddev->raid_disks &&
2758		    __is_raid10_near(mddev->layout) &&
2759		    rs->raid10_copies &&
2760		    rs->raid10_copies != __raid10_near_copies(mddev->layout)) {
2761			/*
2762			 * raid disk have to be multiple of data copies to allow this conversion,
2763			 *
2764			 * This is actually not a reshape it is a
2765			 * rebuild of any additional mirrors per group
2766			 */
2767			if (rs->raid_disks % rs->raid10_copies) {
2768				rs->ti->error = "Can't reshape raid10 mirror groups";
2769				return -EINVAL;
2770			}
2771
2772			/* Userpace reordered disks to add/remove mirrors -> adjust raid_disk indexes */
2773			__reorder_raid_disk_indexes(rs);
2774			mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_NEAR,
2775								   rs->raid10_copies);
2776			mddev->new_layout = mddev->layout;
2777			reshape = false;
2778		} else
2779			reshape = true;
2780
2781	} else if (rs_is_raid456(rs))
2782		reshape = true;
2783
2784	else if (rs_is_raid1(rs)) {
2785		if (rs->delta_disks) {
2786			/* Process raid1 via delta_disks */
2787			mddev->degraded = rs->delta_disks < 0 ? -rs->delta_disks : rs->delta_disks;
2788			reshape = true;
2789		} else {
2790			/* Process raid1 without delta_disks */
2791			mddev->raid_disks = rs->raid_disks;
2792			reshape = false;
2793		}
2794	} else {
2795		rs->ti->error = "Called with bogus raid type";
2796		return -EINVAL;
2797	}
2798
2799	if (reshape) {
2800		set_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags);
2801		set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2802	} else if (mddev->raid_disks < rs->raid_disks)
2803		/* Create new superblocks and bitmaps, if any new disks */
2804		set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2805
2806	return 0;
2807}
2808
2809/* Get reshape sectors from data_offsets or raid set */
2810static sector_t _get_reshape_sectors(struct raid_set *rs)
2811{
2812	struct md_rdev *rdev;
2813	sector_t reshape_sectors = 0;
2814
2815	rdev_for_each(rdev, &rs->md)
2816		if (!test_bit(Journal, &rdev->flags)) {
2817			reshape_sectors = (rdev->data_offset > rdev->new_data_offset) ?
2818					rdev->data_offset - rdev->new_data_offset :
2819					rdev->new_data_offset - rdev->data_offset;
2820			break;
2821		}
2822
2823	return max(reshape_sectors, (sector_t) rs->data_offset);
2824}
2825
2826/*
2827 * Reshape:
2828 * - change raid layout
2829 * - change chunk size
2830 * - add disks
2831 * - remove disks
2832 */
2833static int rs_setup_reshape(struct raid_set *rs)
2834{
2835	int r = 0;
2836	unsigned int cur_raid_devs, d;
2837	sector_t reshape_sectors = _get_reshape_sectors(rs);
2838	struct mddev *mddev = &rs->md;
2839	struct md_rdev *rdev;
2840
2841	mddev->delta_disks = rs->delta_disks;
2842	cur_raid_devs = mddev->raid_disks;
2843
2844	/* Ignore impossible layout change whilst adding/removing disks */
2845	if (mddev->delta_disks &&
2846	    mddev->layout != mddev->new_layout) {
2847		DMINFO("Ignoring invalid layout change with delta_disks=%d", rs->delta_disks);
2848		mddev->new_layout = mddev->layout;
2849	}
2850
2851	/*
2852	 * Adjust array size:
2853	 *
2854	 * - in case of adding disk(s), array size has
2855	 *   to grow after the disk adding reshape,
2856	 *   which'll hapen in the event handler;
2857	 *   reshape will happen forward, so space has to
2858	 *   be available at the beginning of each disk
2859	 *
2860	 * - in case of removing disk(s), array size
2861	 *   has to shrink before starting the reshape,
2862	 *   which'll happen here;
2863	 *   reshape will happen backward, so space has to
2864	 *   be available at the end of each disk
2865	 *
2866	 * - data_offset and new_data_offset are
2867	 *   adjusted for aforementioned out of place
2868	 *   reshaping based on userspace passing in
2869	 *   the "data_offset <sectors>" key/value
2870	 *   pair via the constructor
2871	 */
2872
2873	/* Add disk(s) */
2874	if (rs->delta_disks > 0) {
2875		/* Prepare disks for check in raid4/5/6/10 {check|start}_reshape */
2876		for (d = cur_raid_devs; d < rs->raid_disks; d++) {
2877			rdev = &rs->dev[d].rdev;
2878			clear_bit(In_sync, &rdev->flags);
2879
2880			/*
2881			 * save_raid_disk needs to be -1, or recovery_offset will be set to 0
2882			 * by md, which'll store that erroneously in the superblock on reshape
2883			 */
2884			rdev->saved_raid_disk = -1;
2885			rdev->raid_disk = d;
2886
2887			rdev->sectors = mddev->dev_sectors;
2888			rdev->recovery_offset = rs_is_raid1(rs) ? 0 : MaxSector;
2889		}
2890
2891		mddev->reshape_backwards = 0; /* adding disk(s) -> forward reshape */
2892
2893	/* Remove disk(s) */
2894	} else if (rs->delta_disks < 0) {
2895		r = rs_set_dev_and_array_sectors(rs, rs->ti->len, true);
2896		mddev->reshape_backwards = 1; /* removing disk(s) -> backward reshape */
2897
2898	/* Change layout and/or chunk size */
2899	} else {
2900		/*
2901		 * Reshape layout (e.g. raid5_ls -> raid5_n) and/or chunk size:
2902		 *
2903		 * keeping number of disks and do layout change ->
2904		 *
2905		 * toggle reshape_backward depending on data_offset:
2906		 *
2907		 * - free space upfront -> reshape forward
2908		 *
2909		 * - free space at the end -> reshape backward
2910		 *
2911		 *
2912		 * This utilizes free reshape space avoiding the need
2913		 * for userspace to move (parts of) LV segments in
2914		 * case of layout/chunksize change  (for disk
2915		 * adding/removing reshape space has to be at
2916		 * the proper address (see above with delta_disks):
2917		 *
2918		 * add disk(s)   -> begin
2919		 * remove disk(s)-> end
2920		 */
2921		mddev->reshape_backwards = rs->dev[0].rdev.data_offset ? 0 : 1;
2922	}
2923
2924	/*
2925	 * Adjust device size for forward reshape
2926	 * because md_finish_reshape() reduces it.
2927	 */
2928	if (!mddev->reshape_backwards)
2929		rdev_for_each(rdev, &rs->md)
2930			if (!test_bit(Journal, &rdev->flags))
2931				rdev->sectors += reshape_sectors;
2932
2933	return r;
2934}
2935
2936/*
2937 * If the md resync thread has updated superblock with max reshape position
2938 * at the end of a reshape but not (yet) reset the layout configuration
2939 * changes -> reset the latter.
2940 */
2941static void rs_reset_inconclusive_reshape(struct raid_set *rs)
2942{
2943	if (!rs_is_reshaping(rs) && rs_is_layout_change(rs, true)) {
2944		rs_set_cur(rs);
2945		rs->md.delta_disks = 0;
2946		rs->md.reshape_backwards = 0;
2947	}
2948}
2949
2950/*
2951 * Enable/disable discard support on RAID set depending on
2952 * RAID level and discard properties of underlying RAID members.
2953 */
2954static void configure_discard_support(struct raid_set *rs)
2955{
2956	int i;
2957	bool raid456;
2958	struct dm_target *ti = rs->ti;
2959
2960	/*
2961	 * XXX: RAID level 4,5,6 require zeroing for safety.
2962	 */
2963	raid456 = rs_is_raid456(rs);
2964
2965	for (i = 0; i < rs->raid_disks; i++) {
2966		struct request_queue *q;
2967
2968		if (!rs->dev[i].rdev.bdev)
2969			continue;
2970
2971		q = bdev_get_queue(rs->dev[i].rdev.bdev);
2972		if (!q || !blk_queue_discard(q))
2973			return;
2974
2975		if (raid456) {
2976			if (!devices_handle_discard_safely) {
2977				DMERR("raid456 discard support disabled due to discard_zeroes_data uncertainty.");
2978				DMERR("Set dm-raid.devices_handle_discard_safely=Y to override.");
2979				return;
2980			}
2981		}
2982	}
2983
2984	ti->num_discard_bios = 1;
2985}
2986
2987/*
2988 * Construct a RAID0/1/10/4/5/6 mapping:
2989 * Args:
2990 *	<raid_type> <#raid_params> <raid_params>{0,}	\
2991 *	<#raid_devs> [<meta_dev1> <dev1>]{1,}
2992 *
2993 * <raid_params> varies by <raid_type>.	 See 'parse_raid_params' for
2994 * details on possible <raid_params>.
2995 *
2996 * Userspace is free to initialize the metadata devices, hence the superblocks to
2997 * enforce recreation based on the passed in table parameters.
2998 *
2999 */
3000static int raid_ctr(struct dm_target *ti, unsigned int argc, char **argv)
3001{
3002	int r;
3003	bool resize = false;
3004	struct raid_type *rt;
3005	unsigned int num_raid_params, num_raid_devs;
3006	sector_t sb_array_sectors, rdev_sectors, reshape_sectors;
3007	struct raid_set *rs = NULL;
3008	const char *arg;
3009	struct rs_layout rs_layout;
3010	struct dm_arg_set as = { argc, argv }, as_nrd;
3011	struct dm_arg _args[] = {
3012		{ 0, as.argc, "Cannot understand number of raid parameters" },
3013		{ 1, 254, "Cannot understand number of raid devices parameters" }
3014	};
3015
3016	arg = dm_shift_arg(&as);
3017	if (!arg) {
3018		ti->error = "No arguments";
3019		return -EINVAL;
3020	}
3021
3022	rt = get_raid_type(arg);
3023	if (!rt) {
3024		ti->error = "Unrecognised raid_type";
3025		return -EINVAL;
3026	}
3027
3028	/* Must have <#raid_params> */
3029	if (dm_read_arg_group(_args, &as, &num_raid_params, &ti->error))
3030		return -EINVAL;
3031
3032	/* number of raid device tupples <meta_dev data_dev> */
3033	as_nrd = as;
3034	dm_consume_args(&as_nrd, num_raid_params);
3035	_args[1].max = (as_nrd.argc - 1) / 2;
3036	if (dm_read_arg(_args + 1, &as_nrd, &num_raid_devs, &ti->error))
3037		return -EINVAL;
3038
3039	if (!__within_range(num_raid_devs, 1, MAX_RAID_DEVICES)) {
3040		ti->error = "Invalid number of supplied raid devices";
3041		return -EINVAL;
3042	}
3043
3044	rs = raid_set_alloc(ti, rt, num_raid_devs);
3045	if (IS_ERR(rs))
3046		return PTR_ERR(rs);
3047
3048	r = parse_raid_params(rs, &as, num_raid_params);
3049	if (r)
3050		goto bad;
3051
3052	r = parse_dev_params(rs, &as);
3053	if (r)
3054		goto bad;
3055
3056	rs->md.sync_super = super_sync;
3057
3058	/*
3059	 * Calculate ctr requested array and device sizes to allow
3060	 * for superblock analysis needing device sizes defined.
3061	 *
3062	 * Any existing superblock will overwrite the array and device sizes
3063	 */
3064	r = rs_set_dev_and_array_sectors(rs, rs->ti->len, false);
3065	if (r)
3066		goto bad;
3067
3068	/* Memorize just calculated, potentially larger sizes to grow the raid set in preresume */
3069	rs->array_sectors = rs->md.array_sectors;
3070	rs->dev_sectors = rs->md.dev_sectors;
3071
3072	/*
3073	 * Backup any new raid set level, layout, ...
3074	 * requested to be able to compare to superblock
3075	 * members for conversion decisions.
3076	 */
3077	rs_config_backup(rs, &rs_layout);
3078
3079	r = analyse_superblocks(ti, rs);
3080	if (r)
3081		goto bad;
3082
3083	/* All in-core metadata now as of current superblocks after calling analyse_superblocks() */
3084	sb_array_sectors = rs->md.array_sectors;
3085	rdev_sectors = __rdev_sectors(rs);
3086	if (!rdev_sectors) {
3087		ti->error = "Invalid rdev size";
3088		r = -EINVAL;
3089		goto bad;
3090	}
3091
3092
3093	reshape_sectors = _get_reshape_sectors(rs);
3094	if (rs->dev_sectors != rdev_sectors) {
3095		resize = (rs->dev_sectors != rdev_sectors - reshape_sectors);
3096		if (rs->dev_sectors > rdev_sectors - reshape_sectors)
3097			set_bit(RT_FLAG_RS_GROW, &rs->runtime_flags);
3098	}
3099
3100	INIT_WORK(&rs->md.event_work, do_table_event);
3101	ti->private = rs;
3102	ti->num_flush_bios = 1;
3103
3104	/* Restore any requested new layout for conversion decision */
3105	rs_config_restore(rs, &rs_layout);
3106
3107	/*
3108	 * Now that we have any superblock metadata available,
3109	 * check for new, recovering, reshaping, to be taken over,
3110	 * to be reshaped or an existing, unchanged raid set to
3111	 * run in sequence.
3112	 */
3113	if (test_bit(MD_ARRAY_FIRST_USE, &rs->md.flags)) {
3114		/* A new raid6 set has to be recovered to ensure proper parity and Q-Syndrome */
3115		if (rs_is_raid6(rs) &&
3116		    test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
3117			ti->error = "'nosync' not allowed for new raid6 set";
3118			r = -EINVAL;
3119			goto bad;
3120		}
3121		rs_setup_recovery(rs, 0);
3122		set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
3123		rs_set_new(rs);
3124	} else if (rs_is_recovering(rs)) {
3125		/* A recovering raid set may be resized */
3126		goto size_check;
3127	} else if (rs_is_reshaping(rs)) {
3128		/* Have to reject size change request during reshape */
3129		if (resize) {
3130			ti->error = "Can't resize a reshaping raid set";
3131			r = -EPERM;
3132			goto bad;
3133		}
3134		/* skip setup rs */
3135	} else if (rs_takeover_requested(rs)) {
3136		if (rs_is_reshaping(rs)) {
3137			ti->error = "Can't takeover a reshaping raid set";
3138			r = -EPERM;
3139			goto bad;
3140		}
3141
3142		/* We can't takeover a journaled raid4/5/6 */
3143		if (test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
3144			ti->error = "Can't takeover a journaled raid4/5/6 set";
3145			r = -EPERM;
3146			goto bad;
3147		}
3148
3149		/*
3150		 * If a takeover is needed, userspace sets any additional
3151		 * devices to rebuild and we can check for a valid request here.
3152		 *
3153		 * If acceptible, set the level to the new requested
3154		 * one, prohibit requesting recovery, allow the raid
3155		 * set to run and store superblocks during resume.
3156		 */
3157		r = rs_check_takeover(rs);
3158		if (r)
3159			goto bad;
3160
3161		r = rs_setup_takeover(rs);
3162		if (r)
3163			goto bad;
3164
3165		set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
3166		/* Takeover ain't recovery, so disable recovery */
3167		rs_setup_recovery(rs, MaxSector);
3168		rs_set_new(rs);
3169	} else if (rs_reshape_requested(rs)) {
3170		/* Only request grow on raid set size extensions, not on reshapes. */
3171		clear_bit(RT_FLAG_RS_GROW, &rs->runtime_flags);
3172
3173		/*
3174		 * No need to check for 'ongoing' takeover here, because takeover
3175		 * is an instant operation as oposed to an ongoing reshape.
3176		 */
3177
3178		/* We can't reshape a journaled raid4/5/6 */
3179		if (test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
3180			ti->error = "Can't reshape a journaled raid4/5/6 set";
3181			r = -EPERM;
3182			goto bad;
3183		}
3184
3185		/* Out-of-place space has to be available to allow for a reshape unless raid1! */
3186		if (reshape_sectors || rs_is_raid1(rs)) {
3187			/*
3188			  * We can only prepare for a reshape here, because the
3189			  * raid set needs to run to provide the repective reshape
3190			  * check functions via its MD personality instance.
3191			  *
3192			  * So do the reshape check after md_run() succeeded.
3193			  */
3194			r = rs_prepare_reshape(rs);
3195			if (r)
3196				goto bad;
3197
3198			/* Reshaping ain't recovery, so disable recovery */
3199			rs_setup_recovery(rs, MaxSector);
3200		}
3201		rs_set_cur(rs);
3202	} else {
3203size_check:
3204		/* May not set recovery when a device rebuild is requested */
3205		if (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags)) {
3206			clear_bit(RT_FLAG_RS_GROW, &rs->runtime_flags);
3207			set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
3208			rs_setup_recovery(rs, MaxSector);
3209		} else if (test_bit(RT_FLAG_RS_GROW, &rs->runtime_flags)) {
3210			/*
3211			 * Set raid set to current size, i.e. size as of
3212			 * superblocks to grow to larger size in preresume.
3213			 */
3214			r = rs_set_dev_and_array_sectors(rs, sb_array_sectors, false);
3215			if (r)
3216				goto bad;
3217
3218			rs_setup_recovery(rs, rs->md.recovery_cp < rs->md.dev_sectors ? rs->md.recovery_cp : rs->md.dev_sectors);
3219		} else {
3220			/* This is no size change or it is shrinking, update size and record in superblocks */
3221			r = rs_set_dev_and_array_sectors(rs, rs->ti->len, false);
3222			if (r)
3223				goto bad;
3224
3225			if (sb_array_sectors > rs->array_sectors)
3226				set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
3227		}
3228		rs_set_cur(rs);
3229	}
3230
3231	/* If constructor requested it, change data and new_data offsets */
3232	r = rs_adjust_data_offsets(rs);
3233	if (r)
3234		goto bad;
3235
3236	/* Catch any inconclusive reshape superblock content. */
3237	rs_reset_inconclusive_reshape(rs);
3238
3239	/* Start raid set read-only and assumed clean to change in raid_resume() */
3240	rs->md.ro = 1;
3241	rs->md.in_sync = 1;
3242
3243	/* Keep array frozen until resume. */
3244	set_bit(MD_RECOVERY_FROZEN, &rs->md.recovery);
3245
3246	/* Has to be held on running the array */
3247	mddev_lock_nointr(&rs->md);
3248	r = md_run(&rs->md);
3249	rs->md.in_sync = 0; /* Assume already marked dirty */
3250	if (r) {
3251		ti->error = "Failed to run raid array";
3252		mddev_unlock(&rs->md);
3253		goto bad;
3254	}
3255
3256	r = md_start(&rs->md);
 
3257	if (r) {
3258		ti->error = "Failed to start raid array";
3259		mddev_unlock(&rs->md);
3260		goto bad_md_start;
3261	}
3262
3263	/* If raid4/5/6 journal mode explicitly requested (only possible with journal dev) -> set it */
3264	if (test_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags)) {
3265		r = r5c_journal_mode_set(&rs->md, rs->journal_dev.mode);
3266		if (r) {
3267			ti->error = "Failed to set raid4/5/6 journal mode";
3268			mddev_unlock(&rs->md);
3269			goto bad_journal_mode_set;
3270		}
3271	}
3272
3273	mddev_suspend(&rs->md);
3274	set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags);
3275
3276	/* Try to adjust the raid4/5/6 stripe cache size to the stripe size */
3277	if (rs_is_raid456(rs)) {
3278		r = rs_set_raid456_stripe_cache(rs);
3279		if (r)
3280			goto bad_stripe_cache;
3281	}
3282
3283	/* Now do an early reshape check */
3284	if (test_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags)) {
3285		r = rs_check_reshape(rs);
3286		if (r)
3287			goto bad_check_reshape;
3288
3289		/* Restore new, ctr requested layout to perform check */
3290		rs_config_restore(rs, &rs_layout);
3291
3292		if (rs->md.pers->start_reshape) {
3293			r = rs->md.pers->check_reshape(&rs->md);
3294			if (r) {
3295				ti->error = "Reshape check failed";
3296				goto bad_check_reshape;
3297			}
3298		}
3299	}
3300
3301	/* Disable/enable discard support on raid set. */
3302	configure_discard_support(rs);
3303
3304	mddev_unlock(&rs->md);
3305	return 0;
3306
3307bad_md_start:
3308bad_journal_mode_set:
3309bad_stripe_cache:
3310bad_check_reshape:
3311	md_stop(&rs->md);
3312bad:
3313	raid_set_free(rs);
3314
3315	return r;
3316}
3317
3318static void raid_dtr(struct dm_target *ti)
3319{
3320	struct raid_set *rs = ti->private;
3321
3322	md_stop(&rs->md);
3323	raid_set_free(rs);
3324}
3325
3326static int raid_map(struct dm_target *ti, struct bio *bio)
3327{
3328	struct raid_set *rs = ti->private;
3329	struct mddev *mddev = &rs->md;
3330
3331	/*
3332	 * If we're reshaping to add disk(s)), ti->len and
3333	 * mddev->array_sectors will differ during the process
3334	 * (ti->len > mddev->array_sectors), so we have to requeue
3335	 * bios with addresses > mddev->array_sectors here or
3336	 * there will occur accesses past EOD of the component
3337	 * data images thus erroring the raid set.
3338	 */
3339	if (unlikely(bio_end_sector(bio) > mddev->array_sectors))
3340		return DM_MAPIO_REQUEUE;
3341
3342	md_handle_request(mddev, bio);
3343
3344	return DM_MAPIO_SUBMITTED;
3345}
3346
3347/* Return sync state string for @state */
3348enum sync_state { st_frozen, st_reshape, st_resync, st_check, st_repair, st_recover, st_idle };
3349static const char *sync_str(enum sync_state state)
3350{
3351	/* Has to be in above sync_state order! */
3352	static const char *sync_strs[] = {
3353		"frozen",
3354		"reshape",
3355		"resync",
3356		"check",
3357		"repair",
3358		"recover",
3359		"idle"
3360	};
3361
3362	return __within_range(state, 0, ARRAY_SIZE(sync_strs) - 1) ? sync_strs[state] : "undef";
3363};
3364
3365/* Return enum sync_state for @mddev derived from @recovery flags */
3366static enum sync_state decipher_sync_action(struct mddev *mddev, unsigned long recovery)
3367{
3368	if (test_bit(MD_RECOVERY_FROZEN, &recovery))
3369		return st_frozen;
3370
3371	/* The MD sync thread can be done with io or be interrupted but still be running */
3372	if (!test_bit(MD_RECOVERY_DONE, &recovery) &&
3373	    (test_bit(MD_RECOVERY_RUNNING, &recovery) ||
3374	     (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &recovery)))) {
3375		if (test_bit(MD_RECOVERY_RESHAPE, &recovery))
3376			return st_reshape;
3377
3378		if (test_bit(MD_RECOVERY_SYNC, &recovery)) {
3379			if (!test_bit(MD_RECOVERY_REQUESTED, &recovery))
3380				return st_resync;
3381			if (test_bit(MD_RECOVERY_CHECK, &recovery))
3382				return st_check;
3383			return st_repair;
3384		}
3385
3386		if (test_bit(MD_RECOVERY_RECOVER, &recovery))
3387			return st_recover;
3388
3389		if (mddev->reshape_position != MaxSector)
3390			return st_reshape;
3391	}
3392
3393	return st_idle;
3394}
3395
3396/*
3397 * Return status string for @rdev
3398 *
3399 * Status characters:
3400 *
3401 *  'D' = Dead/Failed raid set component or raid4/5/6 journal device
3402 *  'a' = Alive but not in-sync raid set component _or_ alive raid4/5/6 'write_back' journal device
3403 *  'A' = Alive and in-sync raid set component _or_ alive raid4/5/6 'write_through' journal device
3404 *  '-' = Non-existing device (i.e. uspace passed '- -' into the ctr)
3405 */
3406static const char *__raid_dev_status(struct raid_set *rs, struct md_rdev *rdev)
3407{
3408	if (!rdev->bdev)
3409		return "-";
3410	else if (test_bit(Faulty, &rdev->flags))
3411		return "D";
3412	else if (test_bit(Journal, &rdev->flags))
3413		return (rs->journal_dev.mode == R5C_JOURNAL_MODE_WRITE_THROUGH) ? "A" : "a";
3414	else if (test_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags) ||
3415		 (!test_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags) &&
3416		  !test_bit(In_sync, &rdev->flags)))
3417		return "a";
3418	else
3419		return "A";
3420}
3421
3422/* Helper to return resync/reshape progress for @rs and runtime flags for raid set in sync / resynching */
3423static sector_t rs_get_progress(struct raid_set *rs, unsigned long recovery,
3424				enum sync_state state, sector_t resync_max_sectors)
3425{
3426	sector_t r;
3427	struct mddev *mddev = &rs->md;
3428
3429	clear_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3430	clear_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags);
3431
3432	if (rs_is_raid0(rs)) {
3433		r = resync_max_sectors;
3434		set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3435
3436	} else {
3437		if (state == st_idle && !test_bit(MD_RECOVERY_INTR, &recovery))
3438			r = mddev->recovery_cp;
3439		else
3440			r = mddev->curr_resync_completed;
3441
3442		if (state == st_idle && r >= resync_max_sectors) {
3443			/*
3444			 * Sync complete.
3445			 */
3446			/* In case we have finished recovering, the array is in sync. */
3447			if (test_bit(MD_RECOVERY_RECOVER, &recovery))
3448				set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3449
3450		} else if (state == st_recover)
3451			/*
3452			 * In case we are recovering, the array is not in sync
3453			 * and health chars should show the recovering legs.
3454			 *
3455			 * Already retrieved recovery offset from curr_resync_completed above.
3456			 */
3457			;
3458
3459		else if (state == st_resync || state == st_reshape)
3460			/*
3461			 * If "resync/reshape" is occurring, the raid set
3462			 * is or may be out of sync hence the health
3463			 * characters shall be 'a'.
3464			 */
3465			set_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags);
3466
3467		else if (state == st_check || state == st_repair)
3468			/*
3469			 * If "check" or "repair" is occurring, the raid set has
3470			 * undergone an initial sync and the health characters
3471			 * should not be 'a' anymore.
3472			 */
3473			set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3474
3475		else if (test_bit(MD_RECOVERY_NEEDED, &recovery))
3476			/*
3477			 * We are idle and recovery is needed, prevent 'A' chars race
3478			 * caused by components still set to in-sync by constructor.
3479			 */
3480			set_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags);
3481
3482		else {
3483			/*
3484			 * We are idle and the raid set may be doing an initial
3485			 * sync, or it may be rebuilding individual components.
3486			 * If all the devices are In_sync, then it is the raid set
3487			 * that is being initialized.
3488			 */
3489			struct md_rdev *rdev;
3490
3491			set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3492			rdev_for_each(rdev, mddev)
3493				if (!test_bit(Journal, &rdev->flags) &&
3494				    !test_bit(In_sync, &rdev->flags)) {
3495					clear_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3496					break;
3497				}
3498		}
3499	}
3500
3501	return min(r, resync_max_sectors);
3502}
3503
3504/* Helper to return @dev name or "-" if !@dev */
3505static const char *__get_dev_name(struct dm_dev *dev)
3506{
3507	return dev ? dev->name : "-";
3508}
3509
3510static void raid_status(struct dm_target *ti, status_type_t type,
3511			unsigned int status_flags, char *result, unsigned int maxlen)
3512{
3513	struct raid_set *rs = ti->private;
3514	struct mddev *mddev = &rs->md;
3515	struct r5conf *conf = mddev->private;
3516	int i, max_nr_stripes = conf ? conf->max_nr_stripes : 0;
3517	unsigned long recovery;
3518	unsigned int raid_param_cnt = 1; /* at least 1 for chunksize */
3519	unsigned int sz = 0;
3520	unsigned int rebuild_writemostly_count = 0;
3521	sector_t progress, resync_max_sectors, resync_mismatches;
3522	enum sync_state state;
3523	struct raid_type *rt;
3524
3525	switch (type) {
3526	case STATUSTYPE_INFO:
3527		/* *Should* always succeed */
3528		rt = get_raid_type_by_ll(mddev->new_level, mddev->new_layout);
3529		if (!rt)
3530			return;
3531
3532		DMEMIT("%s %d ", rt->name, mddev->raid_disks);
3533
3534		/* Access most recent mddev properties for status output */
3535		smp_rmb();
3536		/* Get sensible max sectors even if raid set not yet started */
3537		resync_max_sectors = test_bit(RT_FLAG_RS_PRERESUMED, &rs->runtime_flags) ?
3538				      mddev->resync_max_sectors : mddev->dev_sectors;
3539		recovery = rs->md.recovery;
3540		state = decipher_sync_action(mddev, recovery);
3541		progress = rs_get_progress(rs, recovery, state, resync_max_sectors);
3542		resync_mismatches = (mddev->last_sync_action && !strcasecmp(mddev->last_sync_action, "check")) ?
3543				    atomic64_read(&mddev->resync_mismatches) : 0;
3544
3545		/* HM FIXME: do we want another state char for raid0? It shows 'D'/'A'/'-' now */
3546		for (i = 0; i < rs->raid_disks; i++)
3547			DMEMIT(__raid_dev_status(rs, &rs->dev[i].rdev));
3548
3549		/*
3550		 * In-sync/Reshape ratio:
3551		 *  The in-sync ratio shows the progress of:
3552		 *   - Initializing the raid set
3553		 *   - Rebuilding a subset of devices of the raid set
3554		 *  The user can distinguish between the two by referring
3555		 *  to the status characters.
3556		 *
3557		 *  The reshape ratio shows the progress of
3558		 *  changing the raid layout or the number of
3559		 *  disks of a raid set
3560		 */
3561		DMEMIT(" %llu/%llu", (unsigned long long) progress,
3562				     (unsigned long long) resync_max_sectors);
3563
3564		/*
3565		 * v1.5.0+:
3566		 *
3567		 * Sync action:
3568		 *   See Documentation/admin-guide/device-mapper/dm-raid.rst for
3569		 *   information on each of these states.
3570		 */
3571		DMEMIT(" %s", sync_str(state));
3572
3573		/*
3574		 * v1.5.0+:
3575		 *
3576		 * resync_mismatches/mismatch_cnt
3577		 *   This field shows the number of discrepancies found when
3578		 *   performing a "check" of the raid set.
3579		 */
3580		DMEMIT(" %llu", (unsigned long long) resync_mismatches);
3581
3582		/*
3583		 * v1.9.0+:
3584		 *
3585		 * data_offset (needed for out of space reshaping)
3586		 *   This field shows the data offset into the data
3587		 *   image LV where the first stripes data starts.
3588		 *
3589		 * We keep data_offset equal on all raid disks of the set,
3590		 * so retrieving it from the first raid disk is sufficient.
3591		 */
3592		DMEMIT(" %llu", (unsigned long long) rs->dev[0].rdev.data_offset);
3593
3594		/*
3595		 * v1.10.0+:
3596		 */
3597		DMEMIT(" %s", test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags) ?
3598			      __raid_dev_status(rs, &rs->journal_dev.rdev) : "-");
3599		break;
3600
3601	case STATUSTYPE_TABLE:
3602		/* Report the table line string you would use to construct this raid set */
3603
3604		/*
3605		 * Count any rebuild or writemostly argument pairs and subtract the
3606		 * hweight count being added below of any rebuild and writemostly ctr flags.
3607		 */
3608		for (i = 0; i < rs->raid_disks; i++) {
3609			rebuild_writemostly_count += (test_bit(i, (void *) rs->rebuild_disks) ? 2 : 0) +
3610						     (test_bit(WriteMostly, &rs->dev[i].rdev.flags) ? 2 : 0);
3611		}
3612		rebuild_writemostly_count -= (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags) ? 2 : 0) +
3613					     (test_bit(__CTR_FLAG_WRITE_MOSTLY, &rs->ctr_flags) ? 2 : 0);
3614		/* Calculate raid parameter count based on ^ rebuild/writemostly argument counts and ctr flags set. */
3615		raid_param_cnt += rebuild_writemostly_count +
3616				  hweight32(rs->ctr_flags & CTR_FLAG_OPTIONS_NO_ARGS) +
3617				  hweight32(rs->ctr_flags & CTR_FLAG_OPTIONS_ONE_ARG) * 2;
3618		/* Emit table line */
3619		/* This has to be in the documented order for userspace! */
3620		DMEMIT("%s %u %u", rs->raid_type->name, raid_param_cnt, mddev->new_chunk_sectors);
3621		if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags))
3622			DMEMIT(" %s", dm_raid_arg_name_by_flag(CTR_FLAG_SYNC));
3623		if (test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))
3624			DMEMIT(" %s", dm_raid_arg_name_by_flag(CTR_FLAG_NOSYNC));
3625		if (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags))
3626			for (i = 0; i < rs->raid_disks; i++)
3627				if (test_bit(i, (void *) rs->rebuild_disks))
3628					DMEMIT(" %s %u", dm_raid_arg_name_by_flag(CTR_FLAG_REBUILD), i);
3629		if (test_bit(__CTR_FLAG_DAEMON_SLEEP, &rs->ctr_flags))
3630			DMEMIT(" %s %lu", dm_raid_arg_name_by_flag(CTR_FLAG_DAEMON_SLEEP),
3631					  mddev->bitmap_info.daemon_sleep);
3632		if (test_bit(__CTR_FLAG_MIN_RECOVERY_RATE, &rs->ctr_flags))
3633			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_MIN_RECOVERY_RATE),
3634					 mddev->sync_speed_min);
3635		if (test_bit(__CTR_FLAG_MAX_RECOVERY_RATE, &rs->ctr_flags))
3636			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_MAX_RECOVERY_RATE),
3637					 mddev->sync_speed_max);
3638		if (test_bit(__CTR_FLAG_WRITE_MOSTLY, &rs->ctr_flags))
3639			for (i = 0; i < rs->raid_disks; i++)
3640				if (test_bit(WriteMostly, &rs->dev[i].rdev.flags))
3641					DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_WRITE_MOSTLY),
3642					       rs->dev[i].rdev.raid_disk);
3643		if (test_bit(__CTR_FLAG_MAX_WRITE_BEHIND, &rs->ctr_flags))
3644			DMEMIT(" %s %lu", dm_raid_arg_name_by_flag(CTR_FLAG_MAX_WRITE_BEHIND),
3645					  mddev->bitmap_info.max_write_behind);
3646		if (test_bit(__CTR_FLAG_STRIPE_CACHE, &rs->ctr_flags))
3647			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_STRIPE_CACHE),
3648					 max_nr_stripes);
3649		if (test_bit(__CTR_FLAG_REGION_SIZE, &rs->ctr_flags))
3650			DMEMIT(" %s %llu", dm_raid_arg_name_by_flag(CTR_FLAG_REGION_SIZE),
3651					   (unsigned long long) to_sector(mddev->bitmap_info.chunksize));
3652		if (test_bit(__CTR_FLAG_RAID10_COPIES, &rs->ctr_flags))
3653			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_COPIES),
3654					 raid10_md_layout_to_copies(mddev->layout));
3655		if (test_bit(__CTR_FLAG_RAID10_FORMAT, &rs->ctr_flags))
3656			DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_FORMAT),
3657					 raid10_md_layout_to_format(mddev->layout));
3658		if (test_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags))
3659			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_DELTA_DISKS),
3660					 max(rs->delta_disks, mddev->delta_disks));
3661		if (test_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags))
3662			DMEMIT(" %s %llu", dm_raid_arg_name_by_flag(CTR_FLAG_DATA_OFFSET),
3663					   (unsigned long long) rs->data_offset);
3664		if (test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags))
3665			DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_DEV),
3666					__get_dev_name(rs->journal_dev.dev));
3667		if (test_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags))
3668			DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_MODE),
3669					 md_journal_mode_to_dm_raid(rs->journal_dev.mode));
3670		DMEMIT(" %d", rs->raid_disks);
3671		for (i = 0; i < rs->raid_disks; i++)
3672			DMEMIT(" %s %s", __get_dev_name(rs->dev[i].meta_dev),
3673					 __get_dev_name(rs->dev[i].data_dev));
3674	}
3675}
3676
3677static int raid_message(struct dm_target *ti, unsigned int argc, char **argv,
3678			char *result, unsigned maxlen)
3679{
3680	struct raid_set *rs = ti->private;
3681	struct mddev *mddev = &rs->md;
3682
3683	if (!mddev->pers || !mddev->pers->sync_request)
3684		return -EINVAL;
3685
3686	if (!strcasecmp(argv[0], "frozen"))
3687		set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3688	else
3689		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3690
3691	if (!strcasecmp(argv[0], "idle") || !strcasecmp(argv[0], "frozen")) {
3692		if (mddev->sync_thread) {
3693			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
3694			md_reap_sync_thread(mddev);
3695		}
3696	} else if (decipher_sync_action(mddev, mddev->recovery) != st_idle)
3697		return -EBUSY;
3698	else if (!strcasecmp(argv[0], "resync"))
3699		; /* MD_RECOVERY_NEEDED set below */
3700	else if (!strcasecmp(argv[0], "recover"))
3701		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
3702	else {
3703		if (!strcasecmp(argv[0], "check")) {
3704			set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
3705			set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
3706			set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3707		} else if (!strcasecmp(argv[0], "repair")) {
3708			set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
3709			set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3710		} else
3711			return -EINVAL;
3712	}
3713	if (mddev->ro == 2) {
3714		/* A write to sync_action is enough to justify
3715		 * canceling read-auto mode
3716		 */
3717		mddev->ro = 0;
3718		if (!mddev->suspended && mddev->sync_thread)
3719			md_wakeup_thread(mddev->sync_thread);
3720	}
3721	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3722	if (!mddev->suspended && mddev->thread)
3723		md_wakeup_thread(mddev->thread);
3724
3725	return 0;
3726}
3727
3728static int raid_iterate_devices(struct dm_target *ti,
3729				iterate_devices_callout_fn fn, void *data)
3730{
3731	struct raid_set *rs = ti->private;
3732	unsigned int i;
3733	int r = 0;
3734
3735	for (i = 0; !r && i < rs->md.raid_disks; i++)
3736		if (rs->dev[i].data_dev)
3737			r = fn(ti,
3738				 rs->dev[i].data_dev,
3739				 0, /* No offset on data devs */
3740				 rs->md.dev_sectors,
3741				 data);
3742
3743	return r;
3744}
3745
3746static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
3747{
3748	struct raid_set *rs = ti->private;
3749	unsigned int chunk_size_bytes = to_bytes(rs->md.chunk_sectors);
3750
3751	blk_limits_io_min(limits, chunk_size_bytes);
3752	blk_limits_io_opt(limits, chunk_size_bytes * mddev_data_stripes(rs));
 
 
 
 
 
 
 
 
 
3753}
3754
3755static void raid_postsuspend(struct dm_target *ti)
3756{
3757	struct raid_set *rs = ti->private;
3758
3759	if (!test_and_set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) {
3760		/* Writes have to be stopped before suspending to avoid deadlocks. */
3761		if (!test_bit(MD_RECOVERY_FROZEN, &rs->md.recovery))
3762			md_stop_writes(&rs->md);
3763
3764		mddev_lock_nointr(&rs->md);
3765		mddev_suspend(&rs->md);
3766		mddev_unlock(&rs->md);
3767	}
3768}
3769
3770static void attempt_restore_of_faulty_devices(struct raid_set *rs)
3771{
3772	int i;
3773	uint64_t cleared_failed_devices[DISKS_ARRAY_ELEMS];
3774	unsigned long flags;
3775	bool cleared = false;
3776	struct dm_raid_superblock *sb;
3777	struct mddev *mddev = &rs->md;
3778	struct md_rdev *r;
3779
3780	/* RAID personalities have to provide hot add/remove methods or we need to bail out. */
3781	if (!mddev->pers || !mddev->pers->hot_add_disk || !mddev->pers->hot_remove_disk)
3782		return;
3783
3784	memset(cleared_failed_devices, 0, sizeof(cleared_failed_devices));
3785
3786	for (i = 0; i < mddev->raid_disks; i++) {
3787		r = &rs->dev[i].rdev;
3788		/* HM FIXME: enhance journal device recovery processing */
3789		if (test_bit(Journal, &r->flags))
3790			continue;
3791
3792		if (test_bit(Faulty, &r->flags) &&
3793		    r->meta_bdev && !read_disk_sb(r, r->sb_size, true)) {
3794			DMINFO("Faulty %s device #%d has readable super block."
3795			       "  Attempting to revive it.",
3796			       rs->raid_type->name, i);
3797
3798			/*
3799			 * Faulty bit may be set, but sometimes the array can
3800			 * be suspended before the personalities can respond
3801			 * by removing the device from the array (i.e. calling
3802			 * 'hot_remove_disk').	If they haven't yet removed
3803			 * the failed device, its 'raid_disk' number will be
3804			 * '>= 0' - meaning we must call this function
3805			 * ourselves.
3806			 */
3807			flags = r->flags;
3808			clear_bit(In_sync, &r->flags); /* Mandatory for hot remove. */
3809			if (r->raid_disk >= 0) {
3810				if (mddev->pers->hot_remove_disk(mddev, r)) {
3811					/* Failed to revive this device, try next */
3812					r->flags = flags;
3813					continue;
3814				}
3815			} else
3816				r->raid_disk = r->saved_raid_disk = i;
3817
3818			clear_bit(Faulty, &r->flags);
3819			clear_bit(WriteErrorSeen, &r->flags);
3820
3821			if (mddev->pers->hot_add_disk(mddev, r)) {
3822				/* Failed to revive this device, try next */
3823				r->raid_disk = r->saved_raid_disk = -1;
3824				r->flags = flags;
3825			} else {
3826				clear_bit(In_sync, &r->flags);
3827				r->recovery_offset = 0;
3828				set_bit(i, (void *) cleared_failed_devices);
3829				cleared = true;
3830			}
3831		}
3832	}
3833
3834	/* If any failed devices could be cleared, update all sbs failed_devices bits */
3835	if (cleared) {
3836		uint64_t failed_devices[DISKS_ARRAY_ELEMS];
3837
3838		rdev_for_each(r, &rs->md) {
3839			if (test_bit(Journal, &r->flags))
3840				continue;
3841
3842			sb = page_address(r->sb_page);
3843			sb_retrieve_failed_devices(sb, failed_devices);
3844
3845			for (i = 0; i < DISKS_ARRAY_ELEMS; i++)
3846				failed_devices[i] &= ~cleared_failed_devices[i];
3847
3848			sb_update_failed_devices(sb, failed_devices);
3849		}
3850	}
3851}
3852
3853static int __load_dirty_region_bitmap(struct raid_set *rs)
3854{
3855	int r = 0;
3856
3857	/* Try loading the bitmap unless "raid0", which does not have one */
3858	if (!rs_is_raid0(rs) &&
3859	    !test_and_set_bit(RT_FLAG_RS_BITMAP_LOADED, &rs->runtime_flags)) {
3860		r = md_bitmap_load(&rs->md);
3861		if (r)
3862			DMERR("Failed to load bitmap");
3863	}
3864
3865	return r;
3866}
3867
3868/* Enforce updating all superblocks */
3869static void rs_update_sbs(struct raid_set *rs)
3870{
3871	struct mddev *mddev = &rs->md;
3872	int ro = mddev->ro;
3873
3874	set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
3875	mddev->ro = 0;
3876	md_update_sb(mddev, 1);
3877	mddev->ro = ro;
3878}
3879
3880/*
3881 * Reshape changes raid algorithm of @rs to new one within personality
3882 * (e.g. raid6_zr -> raid6_nc), changes stripe size, adds/removes
3883 * disks from a raid set thus growing/shrinking it or resizes the set
3884 *
3885 * Call mddev_lock_nointr() before!
3886 */
3887static int rs_start_reshape(struct raid_set *rs)
3888{
3889	int r;
3890	struct mddev *mddev = &rs->md;
3891	struct md_personality *pers = mddev->pers;
3892
3893	/* Don't allow the sync thread to work until the table gets reloaded. */
3894	set_bit(MD_RECOVERY_WAIT, &mddev->recovery);
3895
3896	r = rs_setup_reshape(rs);
3897	if (r)
3898		return r;
3899
3900	/*
3901	 * Check any reshape constraints enforced by the personalility
3902	 *
3903	 * May as well already kick the reshape off so that * pers->start_reshape() becomes optional.
3904	 */
3905	r = pers->check_reshape(mddev);
3906	if (r) {
3907		rs->ti->error = "pers->check_reshape() failed";
3908		return r;
3909	}
3910
3911	/*
3912	 * Personality may not provide start reshape method in which
3913	 * case check_reshape above has already covered everything
3914	 */
3915	if (pers->start_reshape) {
3916		r = pers->start_reshape(mddev);
3917		if (r) {
3918			rs->ti->error = "pers->start_reshape() failed";
3919			return r;
3920		}
3921	}
3922
3923	/*
3924	 * Now reshape got set up, update superblocks to
3925	 * reflect the fact so that a table reload will
3926	 * access proper superblock content in the ctr.
3927	 */
3928	rs_update_sbs(rs);
3929
3930	return 0;
3931}
3932
3933static int raid_preresume(struct dm_target *ti)
3934{
3935	int r;
3936	struct raid_set *rs = ti->private;
3937	struct mddev *mddev = &rs->md;
3938
3939	/* This is a resume after a suspend of the set -> it's already started. */
3940	if (test_and_set_bit(RT_FLAG_RS_PRERESUMED, &rs->runtime_flags))
3941		return 0;
3942
3943	/*
3944	 * The superblocks need to be updated on disk if the
3945	 * array is new or new devices got added (thus zeroed
3946	 * out by userspace) or __load_dirty_region_bitmap
3947	 * will overwrite them in core with old data or fail.
3948	 */
3949	if (test_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags))
3950		rs_update_sbs(rs);
3951
3952	/* Load the bitmap from disk unless raid0 */
3953	r = __load_dirty_region_bitmap(rs);
3954	if (r)
3955		return r;
3956
3957	/* We are extending the raid set size, adjust mddev/md_rdev sizes and set capacity. */
3958	if (test_bit(RT_FLAG_RS_GROW, &rs->runtime_flags)) {
3959		mddev->array_sectors = rs->array_sectors;
3960		mddev->dev_sectors = rs->dev_sectors;
3961		rs_set_rdev_sectors(rs);
3962		rs_set_capacity(rs);
3963	}
3964
3965	/* Resize bitmap to adjust to changed region size (aka MD bitmap chunksize) or grown device size */
3966        if (test_bit(RT_FLAG_RS_BITMAP_LOADED, &rs->runtime_flags) && mddev->bitmap &&
3967	    (test_bit(RT_FLAG_RS_GROW, &rs->runtime_flags) ||
3968	     (rs->requested_bitmap_chunk_sectors &&
3969	       mddev->bitmap_info.chunksize != to_bytes(rs->requested_bitmap_chunk_sectors)))) {
3970		int chunksize = to_bytes(rs->requested_bitmap_chunk_sectors) ?: mddev->bitmap_info.chunksize;
3971
3972		r = md_bitmap_resize(mddev->bitmap, mddev->dev_sectors, chunksize, 0);
3973		if (r)
3974			DMERR("Failed to resize bitmap");
3975	}
3976
3977	/* Check for any resize/reshape on @rs and adjust/initiate */
3978	/* Be prepared for mddev_resume() in raid_resume() */
3979	set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3980	if (mddev->recovery_cp && mddev->recovery_cp < MaxSector) {
3981		set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
3982		mddev->resync_min = mddev->recovery_cp;
3983		if (test_bit(RT_FLAG_RS_GROW, &rs->runtime_flags))
3984			mddev->resync_max_sectors = mddev->dev_sectors;
3985	}
3986
3987	/* Check for any reshape request unless new raid set */
3988	if (test_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags)) {
3989		/* Initiate a reshape. */
3990		rs_set_rdev_sectors(rs);
3991		mddev_lock_nointr(mddev);
3992		r = rs_start_reshape(rs);
3993		mddev_unlock(mddev);
3994		if (r)
3995			DMWARN("Failed to check/start reshape, continuing without change");
3996		r = 0;
3997	}
3998
3999	return r;
4000}
4001
4002static void raid_resume(struct dm_target *ti)
4003{
4004	struct raid_set *rs = ti->private;
4005	struct mddev *mddev = &rs->md;
4006
4007	if (test_and_set_bit(RT_FLAG_RS_RESUMED, &rs->runtime_flags)) {
4008		/*
4009		 * A secondary resume while the device is active.
4010		 * Take this opportunity to check whether any failed
4011		 * devices are reachable again.
4012		 */
4013		attempt_restore_of_faulty_devices(rs);
4014	}
4015
4016	if (test_and_clear_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) {
4017		/* Only reduce raid set size before running a disk removing reshape. */
4018		if (mddev->delta_disks < 0)
4019			rs_set_capacity(rs);
4020
4021		mddev_lock_nointr(mddev);
4022		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4023		mddev->ro = 0;
4024		mddev->in_sync = 0;
4025		mddev_resume(mddev);
4026		mddev_unlock(mddev);
4027	}
4028}
4029
4030static struct target_type raid_target = {
4031	.name = "raid",
4032	.version = {1, 15, 1},
4033	.module = THIS_MODULE,
4034	.ctr = raid_ctr,
4035	.dtr = raid_dtr,
4036	.map = raid_map,
4037	.status = raid_status,
4038	.message = raid_message,
4039	.iterate_devices = raid_iterate_devices,
4040	.io_hints = raid_io_hints,
4041	.postsuspend = raid_postsuspend,
4042	.preresume = raid_preresume,
4043	.resume = raid_resume,
4044};
4045
4046static int __init dm_raid_init(void)
4047{
4048	DMINFO("Loading target version %u.%u.%u",
4049	       raid_target.version[0],
4050	       raid_target.version[1],
4051	       raid_target.version[2]);
4052	return dm_register_target(&raid_target);
4053}
4054
4055static void __exit dm_raid_exit(void)
4056{
4057	dm_unregister_target(&raid_target);
4058}
4059
4060module_init(dm_raid_init);
4061module_exit(dm_raid_exit);
4062
4063module_param(devices_handle_discard_safely, bool, 0644);
4064MODULE_PARM_DESC(devices_handle_discard_safely,
4065		 "Set to Y if all devices in each array reliably return zeroes on reads from discarded regions");
4066
4067MODULE_DESCRIPTION(DM_NAME " raid0/1/10/4/5/6 target");
4068MODULE_ALIAS("dm-raid0");
4069MODULE_ALIAS("dm-raid1");
4070MODULE_ALIAS("dm-raid10");
4071MODULE_ALIAS("dm-raid4");
4072MODULE_ALIAS("dm-raid5");
4073MODULE_ALIAS("dm-raid6");
4074MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>");
4075MODULE_AUTHOR("Heinz Mauelshagen <dm-devel@redhat.com>");
4076MODULE_LICENSE("GPL");