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v6.2
   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, raid_disks;
1005	unsigned int group_size, last_group_start;
1006
1007	for (i = 0; i < rs->raid_disks; i++)
1008		if (!test_bit(FirstUse, &rs->dev[i].rdev.flags) &&
1009		    ((!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		raid_disks = min(rs->raid_disks, rs->md.raid_disks);
1051		if (__is_raid10_near(rs->md.new_layout)) {
1052			for (i = 0; i < raid_disks; i++) {
1053				if (!(i % copies))
1054					rebuilds_per_group = 0;
1055				if ((!rs->dev[i].rdev.sb_page ||
1056				    !test_bit(In_sync, &rs->dev[i].rdev.flags)) &&
1057				    (++rebuilds_per_group >= copies))
1058					goto too_many;
1059			}
1060			break;
1061		}
1062
1063		/*
1064		 * When checking "far" and "offset" formats, we need to ensure
1065		 * that the device that holds its copy is not also dead or
1066		 * being rebuilt.  (Note that "far" and "offset" formats only
1067		 * support two copies right now.  These formats also only ever
1068		 * use the 'use_far_sets' variant.)
1069		 *
1070		 * This check is somewhat complicated by the need to account
1071		 * for arrays that are not a multiple of (far) copies.	This
1072		 * results in the need to treat the last (potentially larger)
1073		 * set differently.
1074		 */
1075		group_size = (raid_disks / copies);
1076		last_group_start = (raid_disks / group_size) - 1;
1077		last_group_start *= group_size;
1078		for (i = 0; i < raid_disks; i++) {
1079			if (!(i % copies) && !(i > last_group_start))
1080				rebuilds_per_group = 0;
1081			if ((!rs->dev[i].rdev.sb_page ||
1082			     !test_bit(In_sync, &rs->dev[i].rdev.flags)) &&
1083			    (++rebuilds_per_group >= copies))
1084					goto too_many;
1085		}
1086		break;
1087	default:
1088		if (rebuild_cnt)
1089			return -EINVAL;
1090	}
1091
1092	return 0;
1093
1094too_many:
1095	return -EINVAL;
1096}
1097
1098/*
1099 * Possible arguments are...
1100 *	<chunk_size> [optional_args]
1101 *
1102 * Argument definitions
1103 *    <chunk_size>			The number of sectors per disk that
1104 *					will form the "stripe"
1105 *    [[no]sync]			Force or prevent recovery of the
1106 *					entire array
1107 *    [rebuild <idx>]			Rebuild the drive indicated by the index
1108 *    [daemon_sleep <ms>]		Time between bitmap daemon work to
1109 *					clear bits
1110 *    [min_recovery_rate <kB/sec/disk>]	Throttle RAID initialization
1111 *    [max_recovery_rate <kB/sec/disk>]	Throttle RAID initialization
1112 *    [write_mostly <idx>]		Indicate a write mostly drive via index
1113 *    [max_write_behind <sectors>]	See '-write-behind=' (man mdadm)
1114 *    [stripe_cache <sectors>]		Stripe cache size for higher RAIDs
1115 *    [region_size <sectors>]		Defines granularity of bitmap
1116 *    [journal_dev <dev>]		raid4/5/6 journaling deviice
1117 *    					(i.e. write hole closing log)
1118 *
1119 * RAID10-only options:
1120 *    [raid10_copies <# copies>]	Number of copies.  (Default: 2)
1121 *    [raid10_format <near|far|offset>] Layout algorithm.  (Default: near)
1122 */
1123static int parse_raid_params(struct raid_set *rs, struct dm_arg_set *as,
1124			     unsigned int num_raid_params)
1125{
1126	int value, raid10_format = ALGORITHM_RAID10_DEFAULT;
1127	unsigned int raid10_copies = 2;
1128	unsigned int i, write_mostly = 0;
1129	unsigned int region_size = 0;
1130	sector_t max_io_len;
1131	const char *arg, *key;
1132	struct raid_dev *rd;
1133	struct raid_type *rt = rs->raid_type;
1134
1135	arg = dm_shift_arg(as);
1136	num_raid_params--; /* Account for chunk_size argument */
1137
1138	if (kstrtoint(arg, 10, &value) < 0) {
1139		rs->ti->error = "Bad numerical argument given for chunk_size";
1140		return -EINVAL;
1141	}
1142
1143	/*
1144	 * First, parse the in-order required arguments
1145	 * "chunk_size" is the only argument of this type.
1146	 */
1147	if (rt_is_raid1(rt)) {
1148		if (value)
1149			DMERR("Ignoring chunk size parameter for RAID 1");
1150		value = 0;
1151	} else if (!is_power_of_2(value)) {
1152		rs->ti->error = "Chunk size must be a power of 2";
1153		return -EINVAL;
1154	} else if (value < 8) {
1155		rs->ti->error = "Chunk size value is too small";
1156		return -EINVAL;
1157	}
1158
1159	rs->md.new_chunk_sectors = rs->md.chunk_sectors = value;
1160
1161	/*
1162	 * We set each individual device as In_sync with a completed
1163	 * 'recovery_offset'.  If there has been a device failure or
1164	 * replacement then one of the following cases applies:
1165	 *
1166	 *   1) User specifies 'rebuild'.
1167	 *	- Device is reset when param is read.
1168	 *   2) A new device is supplied.
1169	 *	- No matching superblock found, resets device.
1170	 *   3) Device failure was transient and returns on reload.
1171	 *	- Failure noticed, resets device for bitmap replay.
1172	 *   4) Device hadn't completed recovery after previous failure.
1173	 *	- Superblock is read and overrides recovery_offset.
1174	 *
1175	 * What is found in the superblocks of the devices is always
1176	 * authoritative, unless 'rebuild' or '[no]sync' was specified.
1177	 */
1178	for (i = 0; i < rs->raid_disks; i++) {
1179		set_bit(In_sync, &rs->dev[i].rdev.flags);
1180		rs->dev[i].rdev.recovery_offset = MaxSector;
1181	}
1182
1183	/*
1184	 * Second, parse the unordered optional arguments
1185	 */
1186	for (i = 0; i < num_raid_params; i++) {
1187		key = dm_shift_arg(as);
1188		if (!key) {
1189			rs->ti->error = "Not enough raid parameters given";
1190			return -EINVAL;
1191		}
1192
1193		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_NOSYNC))) {
1194			if (test_and_set_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
1195				rs->ti->error = "Only one 'nosync' argument allowed";
1196				return -EINVAL;
1197			}
1198			continue;
1199		}
1200		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_SYNC))) {
1201			if (test_and_set_bit(__CTR_FLAG_SYNC, &rs->ctr_flags)) {
1202				rs->ti->error = "Only one 'sync' argument allowed";
1203				return -EINVAL;
1204			}
1205			continue;
1206		}
1207		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_USE_NEAR_SETS))) {
1208			if (test_and_set_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags)) {
1209				rs->ti->error = "Only one 'raid10_use_new_sets' argument allowed";
1210				return -EINVAL;
1211			}
1212			continue;
1213		}
1214
1215		arg = dm_shift_arg(as);
1216		i++; /* Account for the argument pairs */
1217		if (!arg) {
1218			rs->ti->error = "Wrong number of raid parameters given";
1219			return -EINVAL;
1220		}
1221
1222		/*
1223		 * Parameters that take a string value are checked here.
1224		 */
1225		/* "raid10_format {near|offset|far} */
1226		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_FORMAT))) {
1227			if (test_and_set_bit(__CTR_FLAG_RAID10_FORMAT, &rs->ctr_flags)) {
1228				rs->ti->error = "Only one 'raid10_format' argument pair allowed";
1229				return -EINVAL;
1230			}
1231			if (!rt_is_raid10(rt)) {
1232				rs->ti->error = "'raid10_format' is an invalid parameter for this RAID type";
1233				return -EINVAL;
1234			}
1235			raid10_format = raid10_name_to_format(arg);
1236			if (raid10_format < 0) {
1237				rs->ti->error = "Invalid 'raid10_format' value given";
1238				return raid10_format;
1239			}
1240			continue;
1241		}
1242
1243		/* "journal_dev <dev>" */
1244		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_DEV))) {
1245			int r;
1246			struct md_rdev *jdev;
1247
1248			if (test_and_set_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
1249				rs->ti->error = "Only one raid4/5/6 set journaling device allowed";
1250				return -EINVAL;
1251			}
1252			if (!rt_is_raid456(rt)) {
1253				rs->ti->error = "'journal_dev' is an invalid parameter for this RAID type";
1254				return -EINVAL;
1255			}
1256			r = dm_get_device(rs->ti, arg, dm_table_get_mode(rs->ti->table),
1257					  &rs->journal_dev.dev);
1258			if (r) {
1259				rs->ti->error = "raid4/5/6 journal device lookup failure";
1260				return r;
1261			}
1262			jdev = &rs->journal_dev.rdev;
1263			md_rdev_init(jdev);
1264			jdev->mddev = &rs->md;
1265			jdev->bdev = rs->journal_dev.dev->bdev;
1266			jdev->sectors = bdev_nr_sectors(jdev->bdev);
1267			if (jdev->sectors < MIN_RAID456_JOURNAL_SPACE) {
1268				rs->ti->error = "No space for raid4/5/6 journal";
1269				return -ENOSPC;
1270			}
1271			rs->journal_dev.mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
1272			set_bit(Journal, &jdev->flags);
1273			continue;
1274		}
1275
1276		/* "journal_mode <mode>" ("journal_dev" mandatory!) */
1277		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_MODE))) {
1278			int r;
1279
1280			if (!test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
1281				rs->ti->error = "raid4/5/6 'journal_mode' is invalid without 'journal_dev'";
1282				return -EINVAL;
1283			}
1284			if (test_and_set_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags)) {
1285				rs->ti->error = "Only one raid4/5/6 'journal_mode' argument allowed";
1286				return -EINVAL;
1287			}
1288			r = dm_raid_journal_mode_to_md(arg);
1289			if (r < 0) {
1290				rs->ti->error = "Invalid 'journal_mode' argument";
1291				return r;
1292			}
1293			rs->journal_dev.mode = r;
1294			continue;
1295		}
1296
1297		/*
1298		 * Parameters with number values from here on.
1299		 */
1300		if (kstrtoint(arg, 10, &value) < 0) {
1301			rs->ti->error = "Bad numerical argument given in raid params";
1302			return -EINVAL;
1303		}
1304
1305		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_REBUILD))) {
1306			/*
1307			 * "rebuild" is being passed in by userspace to provide
1308			 * indexes of replaced devices and to set up additional
1309			 * devices on raid level takeover.
1310			 */
1311			if (!__within_range(value, 0, rs->raid_disks - 1)) {
1312				rs->ti->error = "Invalid rebuild index given";
1313				return -EINVAL;
1314			}
1315
1316			if (test_and_set_bit(value, (void *) rs->rebuild_disks)) {
1317				rs->ti->error = "rebuild for this index already given";
1318				return -EINVAL;
1319			}
1320
1321			rd = rs->dev + value;
1322			clear_bit(In_sync, &rd->rdev.flags);
1323			clear_bit(Faulty, &rd->rdev.flags);
1324			rd->rdev.recovery_offset = 0;
1325			set_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags);
1326		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_WRITE_MOSTLY))) {
1327			if (!rt_is_raid1(rt)) {
1328				rs->ti->error = "write_mostly option is only valid for RAID1";
1329				return -EINVAL;
1330			}
1331
1332			if (!__within_range(value, 0, rs->md.raid_disks - 1)) {
1333				rs->ti->error = "Invalid write_mostly index given";
1334				return -EINVAL;
1335			}
1336
1337			write_mostly++;
1338			set_bit(WriteMostly, &rs->dev[value].rdev.flags);
1339			set_bit(__CTR_FLAG_WRITE_MOSTLY, &rs->ctr_flags);
1340		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_MAX_WRITE_BEHIND))) {
1341			if (!rt_is_raid1(rt)) {
1342				rs->ti->error = "max_write_behind option is only valid for RAID1";
1343				return -EINVAL;
1344			}
1345
1346			if (test_and_set_bit(__CTR_FLAG_MAX_WRITE_BEHIND, &rs->ctr_flags)) {
1347				rs->ti->error = "Only one max_write_behind argument pair allowed";
1348				return -EINVAL;
1349			}
1350
1351			/*
1352			 * In device-mapper, we specify things in sectors, but
1353			 * MD records this value in kB
1354			 */
1355			if (value < 0 || value / 2 > COUNTER_MAX) {
1356				rs->ti->error = "Max write-behind limit out of range";
1357				return -EINVAL;
1358			}
1359
1360			rs->md.bitmap_info.max_write_behind = value / 2;
1361		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_DAEMON_SLEEP))) {
1362			if (test_and_set_bit(__CTR_FLAG_DAEMON_SLEEP, &rs->ctr_flags)) {
1363				rs->ti->error = "Only one daemon_sleep argument pair allowed";
1364				return -EINVAL;
1365			}
1366			if (value < 0) {
1367				rs->ti->error = "daemon sleep period out of range";
1368				return -EINVAL;
1369			}
1370			rs->md.bitmap_info.daemon_sleep = value;
1371		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_DATA_OFFSET))) {
1372			/* Userspace passes new data_offset after having extended the data image LV */
1373			if (test_and_set_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags)) {
1374				rs->ti->error = "Only one data_offset argument pair allowed";
1375				return -EINVAL;
1376			}
1377			/* Ensure sensible data offset */
1378			if (value < 0 ||
1379			    (value && (value < MIN_FREE_RESHAPE_SPACE || value % to_sector(PAGE_SIZE)))) {
1380				rs->ti->error = "Bogus data_offset value";
1381				return -EINVAL;
1382			}
1383			rs->data_offset = value;
1384		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_DELTA_DISKS))) {
1385			/* Define the +/-# of disks to add to/remove from the given raid set */
1386			if (test_and_set_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags)) {
1387				rs->ti->error = "Only one delta_disks argument pair allowed";
1388				return -EINVAL;
1389			}
1390			/* Ensure MAX_RAID_DEVICES and raid type minimal_devs! */
1391			if (!__within_range(abs(value), 1, MAX_RAID_DEVICES - rt->minimal_devs)) {
1392				rs->ti->error = "Too many delta_disk requested";
1393				return -EINVAL;
1394			}
1395
1396			rs->delta_disks = value;
1397		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_STRIPE_CACHE))) {
1398			if (test_and_set_bit(__CTR_FLAG_STRIPE_CACHE, &rs->ctr_flags)) {
1399				rs->ti->error = "Only one stripe_cache argument pair allowed";
1400				return -EINVAL;
1401			}
1402
1403			if (!rt_is_raid456(rt)) {
1404				rs->ti->error = "Inappropriate argument: stripe_cache";
1405				return -EINVAL;
1406			}
1407
1408			if (value < 0) {
1409				rs->ti->error = "Bogus stripe cache entries value";
1410				return -EINVAL;
1411			}
1412			rs->stripe_cache_entries = value;
1413		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_MIN_RECOVERY_RATE))) {
1414			if (test_and_set_bit(__CTR_FLAG_MIN_RECOVERY_RATE, &rs->ctr_flags)) {
1415				rs->ti->error = "Only one min_recovery_rate argument pair allowed";
1416				return -EINVAL;
1417			}
1418
1419			if (value < 0) {
1420				rs->ti->error = "min_recovery_rate out of range";
1421				return -EINVAL;
1422			}
1423			rs->md.sync_speed_min = value;
1424		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_MAX_RECOVERY_RATE))) {
1425			if (test_and_set_bit(__CTR_FLAG_MAX_RECOVERY_RATE, &rs->ctr_flags)) {
1426				rs->ti->error = "Only one max_recovery_rate argument pair allowed";
1427				return -EINVAL;
1428			}
1429
1430			if (value < 0) {
1431				rs->ti->error = "max_recovery_rate out of range";
1432				return -EINVAL;
1433			}
1434			rs->md.sync_speed_max = value;
1435		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_REGION_SIZE))) {
1436			if (test_and_set_bit(__CTR_FLAG_REGION_SIZE, &rs->ctr_flags)) {
1437				rs->ti->error = "Only one region_size argument pair allowed";
1438				return -EINVAL;
1439			}
1440
1441			region_size = value;
1442			rs->requested_bitmap_chunk_sectors = value;
1443		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_COPIES))) {
1444			if (test_and_set_bit(__CTR_FLAG_RAID10_COPIES, &rs->ctr_flags)) {
1445				rs->ti->error = "Only one raid10_copies argument pair allowed";
1446				return -EINVAL;
1447			}
1448
1449			if (!__within_range(value, 2, rs->md.raid_disks)) {
1450				rs->ti->error = "Bad value for 'raid10_copies'";
1451				return -EINVAL;
1452			}
1453
1454			raid10_copies = value;
1455		} else {
1456			DMERR("Unable to parse RAID parameter: %s", key);
1457			rs->ti->error = "Unable to parse RAID parameter";
1458			return -EINVAL;
1459		}
1460	}
1461
1462	if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags) &&
1463	    test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
1464		rs->ti->error = "sync and nosync are mutually exclusive";
1465		return -EINVAL;
1466	}
1467
1468	if (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags) &&
1469	    (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags) ||
1470	     test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))) {
1471		rs->ti->error = "sync/nosync and rebuild are mutually exclusive";
1472		return -EINVAL;
1473	}
1474
1475	if (write_mostly >= rs->md.raid_disks) {
1476		rs->ti->error = "Can't set all raid1 devices to write_mostly";
1477		return -EINVAL;
1478	}
1479
1480	if (rs->md.sync_speed_max &&
1481	    rs->md.sync_speed_min > rs->md.sync_speed_max) {
1482		rs->ti->error = "Bogus recovery rates";
1483		return -EINVAL;
1484	}
1485
1486	if (validate_region_size(rs, region_size))
1487		return -EINVAL;
1488
1489	if (rs->md.chunk_sectors)
1490		max_io_len = rs->md.chunk_sectors;
1491	else
1492		max_io_len = region_size;
1493
1494	if (dm_set_target_max_io_len(rs->ti, max_io_len))
1495		return -EINVAL;
1496
1497	if (rt_is_raid10(rt)) {
1498		if (raid10_copies > rs->md.raid_disks) {
1499			rs->ti->error = "Not enough devices to satisfy specification";
1500			return -EINVAL;
1501		}
1502
1503		rs->md.new_layout = raid10_format_to_md_layout(rs, raid10_format, raid10_copies);
1504		if (rs->md.new_layout < 0) {
1505			rs->ti->error = "Error getting raid10 format";
1506			return rs->md.new_layout;
1507		}
1508
1509		rt = get_raid_type_by_ll(10, rs->md.new_layout);
1510		if (!rt) {
1511			rs->ti->error = "Failed to recognize new raid10 layout";
1512			return -EINVAL;
1513		}
1514
1515		if ((rt->algorithm == ALGORITHM_RAID10_DEFAULT ||
1516		     rt->algorithm == ALGORITHM_RAID10_NEAR) &&
1517		    test_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags)) {
1518			rs->ti->error = "RAID10 format 'near' and 'raid10_use_near_sets' are incompatible";
1519			return -EINVAL;
1520		}
1521	}
1522
1523	rs->raid10_copies = raid10_copies;
1524
1525	/* Assume there are no metadata devices until the drives are parsed */
1526	rs->md.persistent = 0;
1527	rs->md.external = 1;
1528
1529	/* Check, if any invalid ctr arguments have been passed in for the raid level */
1530	return rs_check_for_valid_flags(rs);
1531}
1532
1533/* Set raid4/5/6 cache size */
1534static int rs_set_raid456_stripe_cache(struct raid_set *rs)
1535{
1536	int r;
1537	struct r5conf *conf;
1538	struct mddev *mddev = &rs->md;
1539	uint32_t min_stripes = max(mddev->chunk_sectors, mddev->new_chunk_sectors) / 2;
1540	uint32_t nr_stripes = rs->stripe_cache_entries;
1541
1542	if (!rt_is_raid456(rs->raid_type)) {
1543		rs->ti->error = "Inappropriate raid level; cannot change stripe_cache size";
1544		return -EINVAL;
1545	}
1546
1547	if (nr_stripes < min_stripes) {
1548		DMINFO("Adjusting requested %u stripe cache entries to %u to suit stripe size",
1549		       nr_stripes, min_stripes);
1550		nr_stripes = min_stripes;
1551	}
1552
1553	conf = mddev->private;
1554	if (!conf) {
1555		rs->ti->error = "Cannot change stripe_cache size on inactive RAID set";
1556		return -EINVAL;
1557	}
1558
1559	/* Try setting number of stripes in raid456 stripe cache */
1560	if (conf->min_nr_stripes != nr_stripes) {
1561		r = raid5_set_cache_size(mddev, nr_stripes);
1562		if (r) {
1563			rs->ti->error = "Failed to set raid4/5/6 stripe cache size";
1564			return r;
1565		}
1566
1567		DMINFO("%u stripe cache entries", nr_stripes);
1568	}
1569
1570	return 0;
1571}
1572
1573/* Return # of data stripes as kept in mddev as of @rs (i.e. as of superblock) */
1574static unsigned int mddev_data_stripes(struct raid_set *rs)
1575{
1576	return rs->md.raid_disks - rs->raid_type->parity_devs;
1577}
1578
1579/* Return # of data stripes of @rs (i.e. as of ctr) */
1580static unsigned int rs_data_stripes(struct raid_set *rs)
1581{
1582	return rs->raid_disks - rs->raid_type->parity_devs;
1583}
1584
1585/*
1586 * Retrieve rdev->sectors from any valid raid device of @rs
1587 * to allow userpace to pass in arbitray "- -" device tupples.
1588 */
1589static sector_t __rdev_sectors(struct raid_set *rs)
1590{
1591	int i;
1592
1593	for (i = 0; i < rs->raid_disks; i++) {
1594		struct md_rdev *rdev = &rs->dev[i].rdev;
1595
1596		if (!test_bit(Journal, &rdev->flags) &&
1597		    rdev->bdev && rdev->sectors)
1598			return rdev->sectors;
1599	}
1600
1601	return 0;
1602}
1603
1604/* Check that calculated dev_sectors fits all component devices. */
1605static int _check_data_dev_sectors(struct raid_set *rs)
1606{
1607	sector_t ds = ~0;
1608	struct md_rdev *rdev;
1609
1610	rdev_for_each(rdev, &rs->md)
1611		if (!test_bit(Journal, &rdev->flags) && rdev->bdev) {
1612			ds = min(ds, bdev_nr_sectors(rdev->bdev));
1613			if (ds < rs->md.dev_sectors) {
1614				rs->ti->error = "Component device(s) too small";
1615				return -EINVAL;
1616			}
1617		}
1618
1619	return 0;
1620}
1621
1622/* Calculate the sectors per device and per array used for @rs */
1623static int rs_set_dev_and_array_sectors(struct raid_set *rs, sector_t sectors, bool use_mddev)
1624{
1625	int delta_disks;
1626	unsigned int data_stripes;
1627	sector_t array_sectors = sectors, dev_sectors = sectors;
1628	struct mddev *mddev = &rs->md;
1629
1630	if (use_mddev) {
1631		delta_disks = mddev->delta_disks;
1632		data_stripes = mddev_data_stripes(rs);
1633	} else {
1634		delta_disks = rs->delta_disks;
1635		data_stripes = rs_data_stripes(rs);
1636	}
1637
1638	/* Special raid1 case w/o delta_disks support (yet) */
1639	if (rt_is_raid1(rs->raid_type))
1640		;
1641	else if (rt_is_raid10(rs->raid_type)) {
1642		if (rs->raid10_copies < 2 ||
1643		    delta_disks < 0) {
1644			rs->ti->error = "Bogus raid10 data copies or delta disks";
1645			return -EINVAL;
1646		}
1647
1648		dev_sectors *= rs->raid10_copies;
1649		if (sector_div(dev_sectors, data_stripes))
1650			goto bad;
1651
1652		array_sectors = (data_stripes + delta_disks) * dev_sectors;
1653		if (sector_div(array_sectors, rs->raid10_copies))
1654			goto bad;
1655
1656	} else if (sector_div(dev_sectors, data_stripes))
1657		goto bad;
1658
1659	else
1660		/* Striped layouts */
1661		array_sectors = (data_stripes + delta_disks) * dev_sectors;
1662
1663	mddev->array_sectors = array_sectors;
1664	mddev->dev_sectors = dev_sectors;
1665	rs_set_rdev_sectors(rs);
1666
1667	return _check_data_dev_sectors(rs);
1668bad:
1669	rs->ti->error = "Target length not divisible by number of data devices";
1670	return -EINVAL;
1671}
1672
1673/* Setup recovery on @rs */
1674static void rs_setup_recovery(struct raid_set *rs, sector_t dev_sectors)
1675{
1676	/* raid0 does not recover */
1677	if (rs_is_raid0(rs))
1678		rs->md.recovery_cp = MaxSector;
1679	/*
1680	 * A raid6 set has to be recovered either
1681	 * completely or for the grown part to
1682	 * ensure proper parity and Q-Syndrome
1683	 */
1684	else if (rs_is_raid6(rs))
1685		rs->md.recovery_cp = dev_sectors;
1686	/*
1687	 * Other raid set types may skip recovery
1688	 * depending on the 'nosync' flag.
1689	 */
1690	else
1691		rs->md.recovery_cp = test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)
1692				     ? MaxSector : dev_sectors;
1693}
1694
1695static void do_table_event(struct work_struct *ws)
1696{
1697	struct raid_set *rs = container_of(ws, struct raid_set, md.event_work);
1698
1699	smp_rmb(); /* Make sure we access most actual mddev properties */
1700	if (!rs_is_reshaping(rs)) {
1701		if (rs_is_raid10(rs))
1702			rs_set_rdev_sectors(rs);
1703		rs_set_capacity(rs);
1704	}
1705	dm_table_event(rs->ti->table);
1706}
1707
1708/*
1709 * Make sure a valid takover (level switch) is being requested on @rs
1710 *
1711 * Conversions of raid sets from one MD personality to another
1712 * have to conform to restrictions which are enforced here.
1713 */
1714static int rs_check_takeover(struct raid_set *rs)
1715{
1716	struct mddev *mddev = &rs->md;
1717	unsigned int near_copies;
1718
1719	if (rs->md.degraded) {
1720		rs->ti->error = "Can't takeover degraded raid set";
1721		return -EPERM;
1722	}
1723
1724	if (rs_is_reshaping(rs)) {
1725		rs->ti->error = "Can't takeover reshaping raid set";
1726		return -EPERM;
1727	}
1728
1729	switch (mddev->level) {
1730	case 0:
1731		/* raid0 -> raid1/5 with one disk */
1732		if ((mddev->new_level == 1 || mddev->new_level == 5) &&
1733		    mddev->raid_disks == 1)
1734			return 0;
1735
1736		/* raid0 -> raid10 */
1737		if (mddev->new_level == 10 &&
1738		    !(rs->raid_disks % mddev->raid_disks))
1739			return 0;
1740
1741		/* raid0 with multiple disks -> raid4/5/6 */
1742		if (__within_range(mddev->new_level, 4, 6) &&
1743		    mddev->new_layout == ALGORITHM_PARITY_N &&
1744		    mddev->raid_disks > 1)
1745			return 0;
1746
1747		break;
1748
1749	case 10:
1750		/* Can't takeover raid10_offset! */
1751		if (__is_raid10_offset(mddev->layout))
1752			break;
1753
1754		near_copies = __raid10_near_copies(mddev->layout);
1755
1756		/* raid10* -> raid0 */
1757		if (mddev->new_level == 0) {
1758			/* Can takeover raid10_near with raid disks divisable by data copies! */
1759			if (near_copies > 1 &&
1760			    !(mddev->raid_disks % near_copies)) {
1761				mddev->raid_disks /= near_copies;
1762				mddev->delta_disks = mddev->raid_disks;
1763				return 0;
1764			}
1765
1766			/* Can takeover raid10_far */
1767			if (near_copies == 1 &&
1768			    __raid10_far_copies(mddev->layout) > 1)
1769				return 0;
1770
1771			break;
1772		}
1773
1774		/* raid10_{near,far} -> raid1 */
1775		if (mddev->new_level == 1 &&
1776		    max(near_copies, __raid10_far_copies(mddev->layout)) == mddev->raid_disks)
1777			return 0;
1778
1779		/* raid10_{near,far} with 2 disks -> raid4/5 */
1780		if (__within_range(mddev->new_level, 4, 5) &&
1781		    mddev->raid_disks == 2)
1782			return 0;
1783		break;
1784
1785	case 1:
1786		/* raid1 with 2 disks -> raid4/5 */
1787		if (__within_range(mddev->new_level, 4, 5) &&
1788		    mddev->raid_disks == 2) {
1789			mddev->degraded = 1;
1790			return 0;
1791		}
1792
1793		/* raid1 -> raid0 */
1794		if (mddev->new_level == 0 &&
1795		    mddev->raid_disks == 1)
1796			return 0;
1797
1798		/* raid1 -> raid10 */
1799		if (mddev->new_level == 10)
1800			return 0;
1801		break;
1802
1803	case 4:
1804		/* raid4 -> raid0 */
1805		if (mddev->new_level == 0)
1806			return 0;
1807
1808		/* raid4 -> raid1/5 with 2 disks */
1809		if ((mddev->new_level == 1 || mddev->new_level == 5) &&
1810		    mddev->raid_disks == 2)
1811			return 0;
1812
1813		/* raid4 -> raid5/6 with parity N */
1814		if (__within_range(mddev->new_level, 5, 6) &&
1815		    mddev->layout == ALGORITHM_PARITY_N)
1816			return 0;
1817		break;
1818
1819	case 5:
1820		/* raid5 with parity N -> raid0 */
1821		if (mddev->new_level == 0 &&
1822		    mddev->layout == ALGORITHM_PARITY_N)
1823			return 0;
1824
1825		/* raid5 with parity N -> raid4 */
1826		if (mddev->new_level == 4 &&
1827		    mddev->layout == ALGORITHM_PARITY_N)
1828			return 0;
1829
1830		/* raid5 with 2 disks -> raid1/4/10 */
1831		if ((mddev->new_level == 1 || mddev->new_level == 4 || mddev->new_level == 10) &&
1832		    mddev->raid_disks == 2)
1833			return 0;
1834
1835		/* raid5_* ->  raid6_*_6 with Q-Syndrome N (e.g. raid5_ra -> raid6_ra_6 */
1836		if (mddev->new_level == 6 &&
1837		    ((mddev->layout == ALGORITHM_PARITY_N && mddev->new_layout == ALGORITHM_PARITY_N) ||
1838		      __within_range(mddev->new_layout, ALGORITHM_LEFT_ASYMMETRIC_6, ALGORITHM_RIGHT_SYMMETRIC_6)))
1839			return 0;
1840		break;
1841
1842	case 6:
1843		/* raid6 with parity N -> raid0 */
1844		if (mddev->new_level == 0 &&
1845		    mddev->layout == ALGORITHM_PARITY_N)
1846			return 0;
1847
1848		/* raid6 with parity N -> raid4 */
1849		if (mddev->new_level == 4 &&
1850		    mddev->layout == ALGORITHM_PARITY_N)
1851			return 0;
1852
1853		/* raid6_*_n with Q-Syndrome N -> raid5_* */
1854		if (mddev->new_level == 5 &&
1855		    ((mddev->layout == ALGORITHM_PARITY_N && mddev->new_layout == ALGORITHM_PARITY_N) ||
1856		     __within_range(mddev->new_layout, ALGORITHM_LEFT_ASYMMETRIC, ALGORITHM_RIGHT_SYMMETRIC)))
1857			return 0;
1858		break;
1859
1860	default:
1861		break;
1862	}
1863
1864	rs->ti->error = "takeover not possible";
1865	return -EINVAL;
1866}
1867
1868/* True if @rs requested to be taken over */
1869static bool rs_takeover_requested(struct raid_set *rs)
1870{
1871	return rs->md.new_level != rs->md.level;
1872}
1873
1874/* True if layout is set to reshape. */
1875static bool rs_is_layout_change(struct raid_set *rs, bool use_mddev)
1876{
1877	return (use_mddev ? rs->md.delta_disks : rs->delta_disks) ||
1878	       rs->md.new_layout != rs->md.layout ||
1879	       rs->md.new_chunk_sectors != rs->md.chunk_sectors;
1880}
1881
1882/* True if @rs is requested to reshape by ctr */
1883static bool rs_reshape_requested(struct raid_set *rs)
1884{
1885	bool change;
1886	struct mddev *mddev = &rs->md;
1887
1888	if (rs_takeover_requested(rs))
1889		return false;
1890
1891	if (rs_is_raid0(rs))
1892		return false;
1893
1894	change = rs_is_layout_change(rs, false);
 
 
1895
1896	/* Historical case to support raid1 reshape without delta disks */
1897	if (rs_is_raid1(rs)) {
1898		if (rs->delta_disks)
1899			return !!rs->delta_disks;
1900
1901		return !change &&
1902		       mddev->raid_disks != rs->raid_disks;
1903	}
1904
1905	if (rs_is_raid10(rs))
1906		return change &&
1907		       !__is_raid10_far(mddev->new_layout) &&
1908		       rs->delta_disks >= 0;
1909
1910	return change;
1911}
1912
1913/*  Features */
1914#define	FEATURE_FLAG_SUPPORTS_V190	0x1 /* Supports extended superblock */
1915
1916/* State flags for sb->flags */
1917#define	SB_FLAG_RESHAPE_ACTIVE		0x1
1918#define	SB_FLAG_RESHAPE_BACKWARDS	0x2
1919
1920/*
1921 * This structure is never routinely used by userspace, unlike md superblocks.
1922 * Devices with this superblock should only ever be accessed via device-mapper.
1923 */
1924#define DM_RAID_MAGIC 0x64526D44
1925struct dm_raid_superblock {
1926	__le32 magic;		/* "DmRd" */
1927	__le32 compat_features;	/* Used to indicate compatible features (like 1.9.0 ondisk metadata extension) */
1928
1929	__le32 num_devices;	/* Number of devices in this raid set. (Max 64) */
1930	__le32 array_position;	/* The position of this drive in the raid set */
1931
1932	__le64 events;		/* Incremented by md when superblock updated */
1933	__le64 failed_devices;	/* Pre 1.9.0 part of bit field of devices to */
1934				/* indicate failures (see extension below) */
1935
1936	/*
1937	 * This offset tracks the progress of the repair or replacement of
1938	 * an individual drive.
1939	 */
1940	__le64 disk_recovery_offset;
1941
1942	/*
1943	 * This offset tracks the progress of the initial raid set
1944	 * synchronisation/parity calculation.
1945	 */
1946	__le64 array_resync_offset;
1947
1948	/*
1949	 * raid characteristics
1950	 */
1951	__le32 level;
1952	__le32 layout;
1953	__le32 stripe_sectors;
1954
1955	/********************************************************************
1956	 * BELOW FOLLOW V1.9.0 EXTENSIONS TO THE PRISTINE SUPERBLOCK FORMAT!!!
1957	 *
1958	 * FEATURE_FLAG_SUPPORTS_V190 in the compat_features member indicates that those exist
1959	 */
1960
1961	__le32 flags; /* Flags defining array states for reshaping */
1962
1963	/*
1964	 * This offset tracks the progress of a raid
1965	 * set reshape in order to be able to restart it
1966	 */
1967	__le64 reshape_position;
1968
1969	/*
1970	 * These define the properties of the array in case of an interrupted reshape
1971	 */
1972	__le32 new_level;
1973	__le32 new_layout;
1974	__le32 new_stripe_sectors;
1975	__le32 delta_disks;
1976
1977	__le64 array_sectors; /* Array size in sectors */
1978
1979	/*
1980	 * Sector offsets to data on devices (reshaping).
1981	 * Needed to support out of place reshaping, thus
1982	 * not writing over any stripes whilst converting
1983	 * them from old to new layout
1984	 */
1985	__le64 data_offset;
1986	__le64 new_data_offset;
1987
1988	__le64 sectors; /* Used device size in sectors */
1989
1990	/*
1991	 * Additonal Bit field of devices indicating failures to support
1992	 * up to 256 devices with the 1.9.0 on-disk metadata format
1993	 */
1994	__le64 extended_failed_devices[DISKS_ARRAY_ELEMS - 1];
1995
1996	__le32 incompat_features;	/* Used to indicate any incompatible features */
1997
1998	/* Always set rest up to logical block size to 0 when writing (see get_metadata_device() below). */
1999} __packed;
2000
2001/*
2002 * Check for reshape constraints on raid set @rs:
2003 *
2004 * - reshape function non-existent
2005 * - degraded set
2006 * - ongoing recovery
2007 * - ongoing reshape
2008 *
2009 * Returns 0 if none or -EPERM if given constraint
2010 * and error message reference in @errmsg
2011 */
2012static int rs_check_reshape(struct raid_set *rs)
2013{
2014	struct mddev *mddev = &rs->md;
2015
2016	if (!mddev->pers || !mddev->pers->check_reshape)
2017		rs->ti->error = "Reshape not supported";
2018	else if (mddev->degraded)
2019		rs->ti->error = "Can't reshape degraded raid set";
2020	else if (rs_is_recovering(rs))
2021		rs->ti->error = "Convert request on recovering raid set prohibited";
2022	else if (rs_is_reshaping(rs))
2023		rs->ti->error = "raid set already reshaping!";
2024	else if (!(rs_is_raid1(rs) || rs_is_raid10(rs) || rs_is_raid456(rs)))
2025		rs->ti->error = "Reshaping only supported for raid1/4/5/6/10";
2026	else
2027		return 0;
2028
2029	return -EPERM;
2030}
2031
2032static int read_disk_sb(struct md_rdev *rdev, int size, bool force_reload)
2033{
2034	BUG_ON(!rdev->sb_page);
2035
2036	if (rdev->sb_loaded && !force_reload)
2037		return 0;
2038
2039	rdev->sb_loaded = 0;
2040
2041	if (!sync_page_io(rdev, 0, size, rdev->sb_page, REQ_OP_READ, true)) {
2042		DMERR("Failed to read superblock of device at position %d",
2043		      rdev->raid_disk);
2044		md_error(rdev->mddev, rdev);
2045		set_bit(Faulty, &rdev->flags);
2046		return -EIO;
2047	}
2048
2049	rdev->sb_loaded = 1;
2050
2051	return 0;
2052}
2053
2054static void sb_retrieve_failed_devices(struct dm_raid_superblock *sb, uint64_t *failed_devices)
2055{
2056	failed_devices[0] = le64_to_cpu(sb->failed_devices);
2057	memset(failed_devices + 1, 0, sizeof(sb->extended_failed_devices));
2058
2059	if (le32_to_cpu(sb->compat_features) & FEATURE_FLAG_SUPPORTS_V190) {
2060		int i = ARRAY_SIZE(sb->extended_failed_devices);
2061
2062		while (i--)
2063			failed_devices[i+1] = le64_to_cpu(sb->extended_failed_devices[i]);
2064	}
2065}
2066
2067static void sb_update_failed_devices(struct dm_raid_superblock *sb, uint64_t *failed_devices)
2068{
2069	int i = ARRAY_SIZE(sb->extended_failed_devices);
2070
2071	sb->failed_devices = cpu_to_le64(failed_devices[0]);
2072	while (i--)
2073		sb->extended_failed_devices[i] = cpu_to_le64(failed_devices[i+1]);
2074}
2075
2076/*
2077 * Synchronize the superblock members with the raid set properties
2078 *
2079 * All superblock data is little endian.
2080 */
2081static void super_sync(struct mddev *mddev, struct md_rdev *rdev)
2082{
2083	bool update_failed_devices = false;
2084	unsigned int i;
2085	uint64_t failed_devices[DISKS_ARRAY_ELEMS];
2086	struct dm_raid_superblock *sb;
2087	struct raid_set *rs = container_of(mddev, struct raid_set, md);
2088
2089	/* No metadata device, no superblock */
2090	if (!rdev->meta_bdev)
2091		return;
2092
2093	BUG_ON(!rdev->sb_page);
2094
2095	sb = page_address(rdev->sb_page);
2096
2097	sb_retrieve_failed_devices(sb, failed_devices);
2098
2099	for (i = 0; i < rs->raid_disks; i++)
2100		if (!rs->dev[i].data_dev || test_bit(Faulty, &rs->dev[i].rdev.flags)) {
2101			update_failed_devices = true;
2102			set_bit(i, (void *) failed_devices);
2103		}
2104
2105	if (update_failed_devices)
2106		sb_update_failed_devices(sb, failed_devices);
2107
2108	sb->magic = cpu_to_le32(DM_RAID_MAGIC);
2109	sb->compat_features = cpu_to_le32(FEATURE_FLAG_SUPPORTS_V190);
2110
2111	sb->num_devices = cpu_to_le32(mddev->raid_disks);
2112	sb->array_position = cpu_to_le32(rdev->raid_disk);
2113
2114	sb->events = cpu_to_le64(mddev->events);
2115
2116	sb->disk_recovery_offset = cpu_to_le64(rdev->recovery_offset);
2117	sb->array_resync_offset = cpu_to_le64(mddev->recovery_cp);
2118
2119	sb->level = cpu_to_le32(mddev->level);
2120	sb->layout = cpu_to_le32(mddev->layout);
2121	sb->stripe_sectors = cpu_to_le32(mddev->chunk_sectors);
2122
2123	/********************************************************************
2124	 * BELOW FOLLOW V1.9.0 EXTENSIONS TO THE PRISTINE SUPERBLOCK FORMAT!!!
2125	 *
2126	 * FEATURE_FLAG_SUPPORTS_V190 in the compat_features member indicates that those exist
2127	 */
2128	sb->new_level = cpu_to_le32(mddev->new_level);
2129	sb->new_layout = cpu_to_le32(mddev->new_layout);
2130	sb->new_stripe_sectors = cpu_to_le32(mddev->new_chunk_sectors);
2131
2132	sb->delta_disks = cpu_to_le32(mddev->delta_disks);
2133
2134	smp_rmb(); /* Make sure we access most recent reshape position */
2135	sb->reshape_position = cpu_to_le64(mddev->reshape_position);
2136	if (le64_to_cpu(sb->reshape_position) != MaxSector) {
2137		/* Flag ongoing reshape */
2138		sb->flags |= cpu_to_le32(SB_FLAG_RESHAPE_ACTIVE);
2139
2140		if (mddev->delta_disks < 0 || mddev->reshape_backwards)
2141			sb->flags |= cpu_to_le32(SB_FLAG_RESHAPE_BACKWARDS);
2142	} else {
2143		/* Clear reshape flags */
2144		sb->flags &= ~(cpu_to_le32(SB_FLAG_RESHAPE_ACTIVE|SB_FLAG_RESHAPE_BACKWARDS));
2145	}
2146
2147	sb->array_sectors = cpu_to_le64(mddev->array_sectors);
2148	sb->data_offset = cpu_to_le64(rdev->data_offset);
2149	sb->new_data_offset = cpu_to_le64(rdev->new_data_offset);
2150	sb->sectors = cpu_to_le64(rdev->sectors);
2151	sb->incompat_features = cpu_to_le32(0);
2152
2153	/* Zero out the rest of the payload after the size of the superblock */
2154	memset(sb + 1, 0, rdev->sb_size - sizeof(*sb));
2155}
2156
2157/*
2158 * super_load
2159 *
2160 * This function creates a superblock if one is not found on the device
2161 * and will decide which superblock to use if there's a choice.
2162 *
2163 * Return: 1 if use rdev, 0 if use refdev, -Exxx otherwise
2164 */
2165static int super_load(struct md_rdev *rdev, struct md_rdev *refdev)
2166{
2167	int r;
2168	struct dm_raid_superblock *sb;
2169	struct dm_raid_superblock *refsb;
2170	uint64_t events_sb, events_refsb;
2171
2172	r = read_disk_sb(rdev, rdev->sb_size, false);
2173	if (r)
2174		return r;
2175
2176	sb = page_address(rdev->sb_page);
2177
2178	/*
2179	 * Two cases that we want to write new superblocks and rebuild:
2180	 * 1) New device (no matching magic number)
2181	 * 2) Device specified for rebuild (!In_sync w/ offset == 0)
2182	 */
2183	if ((sb->magic != cpu_to_le32(DM_RAID_MAGIC)) ||
2184	    (!test_bit(In_sync, &rdev->flags) && !rdev->recovery_offset)) {
2185		super_sync(rdev->mddev, rdev);
2186
2187		set_bit(FirstUse, &rdev->flags);
2188		sb->compat_features = cpu_to_le32(FEATURE_FLAG_SUPPORTS_V190);
2189
2190		/* Force writing of superblocks to disk */
2191		set_bit(MD_SB_CHANGE_DEVS, &rdev->mddev->sb_flags);
2192
2193		/* Any superblock is better than none, choose that if given */
2194		return refdev ? 0 : 1;
2195	}
2196
2197	if (!refdev)
2198		return 1;
2199
2200	events_sb = le64_to_cpu(sb->events);
2201
2202	refsb = page_address(refdev->sb_page);
2203	events_refsb = le64_to_cpu(refsb->events);
2204
2205	return (events_sb > events_refsb) ? 1 : 0;
2206}
2207
2208static int super_init_validation(struct raid_set *rs, struct md_rdev *rdev)
2209{
2210	int role;
2211	unsigned int d;
2212	struct mddev *mddev = &rs->md;
2213	uint64_t events_sb;
2214	uint64_t failed_devices[DISKS_ARRAY_ELEMS];
2215	struct dm_raid_superblock *sb;
2216	uint32_t new_devs = 0, rebuild_and_new = 0, rebuilds = 0;
2217	struct md_rdev *r;
2218	struct dm_raid_superblock *sb2;
2219
2220	sb = page_address(rdev->sb_page);
2221	events_sb = le64_to_cpu(sb->events);
2222
2223	/*
2224	 * Initialise to 1 if this is a new superblock.
2225	 */
2226	mddev->events = events_sb ? : 1;
2227
2228	mddev->reshape_position = MaxSector;
2229
2230	mddev->raid_disks = le32_to_cpu(sb->num_devices);
2231	mddev->level = le32_to_cpu(sb->level);
2232	mddev->layout = le32_to_cpu(sb->layout);
2233	mddev->chunk_sectors = le32_to_cpu(sb->stripe_sectors);
2234
2235	/*
2236	 * Reshaping is supported, e.g. reshape_position is valid
2237	 * in superblock and superblock content is authoritative.
2238	 */
2239	if (le32_to_cpu(sb->compat_features) & FEATURE_FLAG_SUPPORTS_V190) {
2240		/* Superblock is authoritative wrt given raid set layout! */
2241		mddev->new_level = le32_to_cpu(sb->new_level);
2242		mddev->new_layout = le32_to_cpu(sb->new_layout);
2243		mddev->new_chunk_sectors = le32_to_cpu(sb->new_stripe_sectors);
2244		mddev->delta_disks = le32_to_cpu(sb->delta_disks);
2245		mddev->array_sectors = le64_to_cpu(sb->array_sectors);
2246
2247		/* raid was reshaping and got interrupted */
2248		if (le32_to_cpu(sb->flags) & SB_FLAG_RESHAPE_ACTIVE) {
2249			if (test_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags)) {
2250				DMERR("Reshape requested but raid set is still reshaping");
2251				return -EINVAL;
2252			}
2253
2254			if (mddev->delta_disks < 0 ||
2255			    (!mddev->delta_disks && (le32_to_cpu(sb->flags) & SB_FLAG_RESHAPE_BACKWARDS)))
2256				mddev->reshape_backwards = 1;
2257			else
2258				mddev->reshape_backwards = 0;
2259
2260			mddev->reshape_position = le64_to_cpu(sb->reshape_position);
2261			rs->raid_type = get_raid_type_by_ll(mddev->level, mddev->layout);
2262		}
2263
2264	} else {
2265		/*
2266		 * No takeover/reshaping, because we don't have the extended v1.9.0 metadata
2267		 */
2268		struct raid_type *rt_cur = get_raid_type_by_ll(mddev->level, mddev->layout);
2269		struct raid_type *rt_new = get_raid_type_by_ll(mddev->new_level, mddev->new_layout);
2270
2271		if (rs_takeover_requested(rs)) {
2272			if (rt_cur && rt_new)
2273				DMERR("Takeover raid sets from %s to %s not yet supported by metadata. (raid level change)",
2274				      rt_cur->name, rt_new->name);
2275			else
2276				DMERR("Takeover raid sets not yet supported by metadata. (raid level change)");
2277			return -EINVAL;
2278		} else if (rs_reshape_requested(rs)) {
2279			DMERR("Reshaping raid sets not yet supported by metadata. (raid layout change keeping level)");
2280			if (mddev->layout != mddev->new_layout) {
2281				if (rt_cur && rt_new)
2282					DMERR("	 current layout %s vs new layout %s",
2283					      rt_cur->name, rt_new->name);
2284				else
2285					DMERR("	 current layout 0x%X vs new layout 0x%X",
2286					      le32_to_cpu(sb->layout), mddev->new_layout);
2287			}
2288			if (mddev->chunk_sectors != mddev->new_chunk_sectors)
2289				DMERR("	 current stripe sectors %u vs new stripe sectors %u",
2290				      mddev->chunk_sectors, mddev->new_chunk_sectors);
2291			if (rs->delta_disks)
2292				DMERR("	 current %u disks vs new %u disks",
2293				      mddev->raid_disks, mddev->raid_disks + rs->delta_disks);
2294			if (rs_is_raid10(rs)) {
2295				DMERR("	 Old layout: %s w/ %u copies",
2296				      raid10_md_layout_to_format(mddev->layout),
2297				      raid10_md_layout_to_copies(mddev->layout));
2298				DMERR("	 New layout: %s w/ %u copies",
2299				      raid10_md_layout_to_format(mddev->new_layout),
2300				      raid10_md_layout_to_copies(mddev->new_layout));
2301			}
2302			return -EINVAL;
2303		}
2304
2305		DMINFO("Discovered old metadata format; upgrading to extended metadata format");
2306	}
2307
2308	if (!test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))
2309		mddev->recovery_cp = le64_to_cpu(sb->array_resync_offset);
2310
2311	/*
2312	 * During load, we set FirstUse if a new superblock was written.
2313	 * There are two reasons we might not have a superblock:
2314	 * 1) The raid set is brand new - in which case, all of the
2315	 *    devices must have their In_sync bit set.	Also,
2316	 *    recovery_cp must be 0, unless forced.
2317	 * 2) This is a new device being added to an old raid set
2318	 *    and the new device needs to be rebuilt - in which
2319	 *    case the In_sync bit will /not/ be set and
2320	 *    recovery_cp must be MaxSector.
2321	 * 3) This is/are a new device(s) being added to an old
2322	 *    raid set during takeover to a higher raid level
2323	 *    to provide capacity for redundancy or during reshape
2324	 *    to add capacity to grow the raid set.
2325	 */
2326	d = 0;
2327	rdev_for_each(r, mddev) {
2328		if (test_bit(Journal, &rdev->flags))
2329			continue;
2330
2331		if (test_bit(FirstUse, &r->flags))
2332			new_devs++;
2333
2334		if (!test_bit(In_sync, &r->flags)) {
2335			DMINFO("Device %d specified for rebuild; clearing superblock",
2336				r->raid_disk);
2337			rebuilds++;
2338
2339			if (test_bit(FirstUse, &r->flags))
2340				rebuild_and_new++;
2341		}
2342
2343		d++;
2344	}
2345
2346	if (new_devs == rs->raid_disks || !rebuilds) {
2347		/* Replace a broken device */
2348		if (new_devs == rs->raid_disks) {
2349			DMINFO("Superblocks created for new raid set");
2350			set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
2351		} else if (new_devs != rebuilds &&
2352			   new_devs != rs->delta_disks) {
2353			DMERR("New device injected into existing raid set without "
2354			      "'delta_disks' or 'rebuild' parameter specified");
2355			return -EINVAL;
2356		}
2357	} else if (new_devs && new_devs != rebuilds) {
2358		DMERR("%u 'rebuild' devices cannot be injected into"
2359		      " a raid set with %u other first-time devices",
2360		      rebuilds, new_devs);
2361		return -EINVAL;
2362	} else if (rebuilds) {
2363		if (rebuild_and_new && rebuilds != rebuild_and_new) {
2364			DMERR("new device%s provided without 'rebuild'",
2365			      new_devs > 1 ? "s" : "");
2366			return -EINVAL;
2367		} else if (!test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags) && rs_is_recovering(rs)) {
2368			DMERR("'rebuild' specified while raid set is not in-sync (recovery_cp=%llu)",
2369			      (unsigned long long) mddev->recovery_cp);
2370			return -EINVAL;
2371		} else if (rs_is_reshaping(rs)) {
2372			DMERR("'rebuild' specified while raid set is being reshaped (reshape_position=%llu)",
2373			      (unsigned long long) mddev->reshape_position);
2374			return -EINVAL;
2375		}
2376	}
2377
2378	/*
2379	 * Now we set the Faulty bit for those devices that are
2380	 * recorded in the superblock as failed.
2381	 */
2382	sb_retrieve_failed_devices(sb, failed_devices);
2383	rdev_for_each(r, mddev) {
2384		if (test_bit(Journal, &rdev->flags) ||
2385		    !r->sb_page)
2386			continue;
2387		sb2 = page_address(r->sb_page);
2388		sb2->failed_devices = 0;
2389		memset(sb2->extended_failed_devices, 0, sizeof(sb2->extended_failed_devices));
2390
2391		/*
2392		 * Check for any device re-ordering.
2393		 */
2394		if (!test_bit(FirstUse, &r->flags) && (r->raid_disk >= 0)) {
2395			role = le32_to_cpu(sb2->array_position);
2396			if (role < 0)
2397				continue;
2398
2399			if (role != r->raid_disk) {
2400				if (rs_is_raid10(rs) && __is_raid10_near(mddev->layout)) {
2401					if (mddev->raid_disks % __raid10_near_copies(mddev->layout) ||
2402					    rs->raid_disks % rs->raid10_copies) {
2403						rs->ti->error =
2404							"Cannot change raid10 near set to odd # of devices!";
2405						return -EINVAL;
2406					}
2407
2408					sb2->array_position = cpu_to_le32(r->raid_disk);
2409
2410				} else if (!(rs_is_raid10(rs) && rt_is_raid0(rs->raid_type)) &&
2411					   !(rs_is_raid0(rs) && rt_is_raid10(rs->raid_type)) &&
2412					   !rt_is_raid1(rs->raid_type)) {
2413					rs->ti->error = "Cannot change device positions in raid set";
2414					return -EINVAL;
2415				}
2416
2417				DMINFO("raid device #%d now at position #%d", role, r->raid_disk);
2418			}
2419
2420			/*
2421			 * Partial recovery is performed on
2422			 * returning failed devices.
2423			 */
2424			if (test_bit(role, (void *) failed_devices))
2425				set_bit(Faulty, &r->flags);
2426		}
2427	}
2428
2429	return 0;
2430}
2431
2432static int super_validate(struct raid_set *rs, struct md_rdev *rdev)
2433{
2434	struct mddev *mddev = &rs->md;
2435	struct dm_raid_superblock *sb;
2436
2437	if (rs_is_raid0(rs) || !rdev->sb_page || rdev->raid_disk < 0)
2438		return 0;
2439
2440	sb = page_address(rdev->sb_page);
2441
2442	/*
2443	 * If mddev->events is not set, we know we have not yet initialized
2444	 * the array.
2445	 */
2446	if (!mddev->events && super_init_validation(rs, rdev))
2447		return -EINVAL;
2448
2449	if (le32_to_cpu(sb->compat_features) &&
2450	    le32_to_cpu(sb->compat_features) != FEATURE_FLAG_SUPPORTS_V190) {
2451		rs->ti->error = "Unable to assemble array: Unknown flag(s) in compatible feature flags";
2452		return -EINVAL;
2453	}
2454
2455	if (sb->incompat_features) {
2456		rs->ti->error = "Unable to assemble array: No incompatible feature flags supported yet";
2457		return -EINVAL;
2458	}
2459
2460	/* Enable bitmap creation on @rs unless no metadevs or raid0 or journaled raid4/5/6 set. */
2461	mddev->bitmap_info.offset = (rt_is_raid0(rs->raid_type) || rs->journal_dev.dev) ? 0 : to_sector(4096);
2462	mddev->bitmap_info.default_offset = mddev->bitmap_info.offset;
2463
2464	if (!test_and_clear_bit(FirstUse, &rdev->flags)) {
2465		/*
2466		 * Retrieve rdev size stored in superblock to be prepared for shrink.
2467		 * Check extended superblock members are present otherwise the size
2468		 * will not be set!
2469		 */
2470		if (le32_to_cpu(sb->compat_features) & FEATURE_FLAG_SUPPORTS_V190)
2471			rdev->sectors = le64_to_cpu(sb->sectors);
2472
2473		rdev->recovery_offset = le64_to_cpu(sb->disk_recovery_offset);
2474		if (rdev->recovery_offset == MaxSector)
2475			set_bit(In_sync, &rdev->flags);
2476		/*
2477		 * If no reshape in progress -> we're recovering single
2478		 * disk(s) and have to set the device(s) to out-of-sync
2479		 */
2480		else if (!rs_is_reshaping(rs))
2481			clear_bit(In_sync, &rdev->flags); /* Mandatory for recovery */
2482	}
2483
2484	/*
2485	 * If a device comes back, set it as not In_sync and no longer faulty.
2486	 */
2487	if (test_and_clear_bit(Faulty, &rdev->flags)) {
2488		rdev->recovery_offset = 0;
2489		clear_bit(In_sync, &rdev->flags);
2490		rdev->saved_raid_disk = rdev->raid_disk;
2491	}
2492
2493	/* Reshape support -> restore repective data offsets */
2494	rdev->data_offset = le64_to_cpu(sb->data_offset);
2495	rdev->new_data_offset = le64_to_cpu(sb->new_data_offset);
2496
2497	return 0;
2498}
2499
2500/*
2501 * Analyse superblocks and select the freshest.
2502 */
2503static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
2504{
2505	int r;
2506	struct md_rdev *rdev, *freshest;
2507	struct mddev *mddev = &rs->md;
2508
2509	freshest = NULL;
2510	rdev_for_each(rdev, mddev) {
2511		if (test_bit(Journal, &rdev->flags))
2512			continue;
2513
2514		if (!rdev->meta_bdev)
2515			continue;
2516
2517		/* Set superblock offset/size for metadata device. */
2518		rdev->sb_start = 0;
2519		rdev->sb_size = bdev_logical_block_size(rdev->meta_bdev);
2520		if (rdev->sb_size < sizeof(struct dm_raid_superblock) || rdev->sb_size > PAGE_SIZE) {
2521			DMERR("superblock size of a logical block is no longer valid");
2522			return -EINVAL;
2523		}
2524
2525		/*
2526		 * Skipping super_load due to CTR_FLAG_SYNC will cause
2527		 * the array to undergo initialization again as
2528		 * though it were new.	This is the intended effect
2529		 * of the "sync" directive.
2530		 *
2531		 * With reshaping capability added, we must ensure that
2532		 * the "sync" directive is disallowed during the reshape.
2533		 */
2534		if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags))
2535			continue;
2536
2537		r = super_load(rdev, freshest);
2538
2539		switch (r) {
2540		case 1:
2541			freshest = rdev;
2542			break;
2543		case 0:
2544			break;
2545		default:
2546			/* This is a failure to read the superblock from the metadata device. */
2547			/*
2548			 * We have to keep any raid0 data/metadata device pairs or
2549			 * the MD raid0 personality will fail to start the array.
2550			 */
2551			if (rs_is_raid0(rs))
2552				continue;
2553
2554			/*
2555			 * We keep the dm_devs to be able to emit the device tuple
2556			 * properly on the table line in raid_status() (rather than
2557			 * mistakenly acting as if '- -' got passed into the constructor).
2558			 *
2559			 * The rdev has to stay on the same_set list to allow for
2560			 * the attempt to restore faulty devices on second resume.
2561			 */
2562			rdev->raid_disk = rdev->saved_raid_disk = -1;
2563			break;
2564		}
2565	}
2566
2567	if (!freshest)
2568		return 0;
2569
2570	/*
2571	 * Validation of the freshest device provides the source of
2572	 * validation for the remaining devices.
2573	 */
2574	rs->ti->error = "Unable to assemble array: Invalid superblocks";
2575	if (super_validate(rs, freshest))
2576		return -EINVAL;
2577
2578	if (validate_raid_redundancy(rs)) {
2579		rs->ti->error = "Insufficient redundancy to activate array";
2580		return -EINVAL;
2581	}
2582
2583	rdev_for_each(rdev, mddev)
2584		if (!test_bit(Journal, &rdev->flags) &&
2585		    rdev != freshest &&
2586		    super_validate(rs, rdev))
2587			return -EINVAL;
2588	return 0;
2589}
2590
2591/*
2592 * Adjust data_offset and new_data_offset on all disk members of @rs
2593 * for out of place reshaping if requested by constructor
2594 *
2595 * We need free space at the beginning of each raid disk for forward
2596 * and at the end for backward reshapes which userspace has to provide
2597 * via remapping/reordering of space.
2598 */
2599static int rs_adjust_data_offsets(struct raid_set *rs)
2600{
2601	sector_t data_offset = 0, new_data_offset = 0;
2602	struct md_rdev *rdev;
2603
2604	/* Constructor did not request data offset change */
2605	if (!test_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags)) {
2606		if (!rs_is_reshapable(rs))
2607			goto out;
2608
2609		return 0;
2610	}
2611
2612	/* HM FIXME: get In_Sync raid_dev? */
2613	rdev = &rs->dev[0].rdev;
2614
2615	if (rs->delta_disks < 0) {
2616		/*
2617		 * Removing disks (reshaping backwards):
2618		 *
2619		 * - before reshape: data is at offset 0 and free space
2620		 *		     is at end of each component LV
2621		 *
2622		 * - after reshape: data is at offset rs->data_offset != 0 on each component LV
2623		 */
2624		data_offset = 0;
2625		new_data_offset = rs->data_offset;
2626
2627	} else if (rs->delta_disks > 0) {
2628		/*
2629		 * Adding disks (reshaping forwards):
2630		 *
2631		 * - before reshape: data is at offset rs->data_offset != 0 and
2632		 *		     free space is at begin of each component LV
2633		 *
2634		 * - after reshape: data is at offset 0 on each component LV
2635		 */
2636		data_offset = rs->data_offset;
2637		new_data_offset = 0;
2638
2639	} else {
2640		/*
2641		 * User space passes in 0 for data offset after having removed reshape space
2642		 *
2643		 * - or - (data offset != 0)
2644		 *
2645		 * Changing RAID layout or chunk size -> toggle offsets
2646		 *
2647		 * - before reshape: data is at offset rs->data_offset 0 and
2648		 *		     free space is at end of each component LV
2649		 *		     -or-
2650		 *                   data is at offset rs->data_offset != 0 and
2651		 *		     free space is at begin of each component LV
2652		 *
2653		 * - after reshape: data is at offset 0 if it was at offset != 0
2654		 *                  or at offset != 0 if it was at offset 0
2655		 *                  on each component LV
2656		 *
2657		 */
2658		data_offset = rs->data_offset ? rdev->data_offset : 0;
2659		new_data_offset = data_offset ? 0 : rs->data_offset;
2660		set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2661	}
2662
2663	/*
2664	 * Make sure we got a minimum amount of free sectors per device
2665	 */
2666	if (rs->data_offset &&
2667	    bdev_nr_sectors(rdev->bdev) - rs->md.dev_sectors < MIN_FREE_RESHAPE_SPACE) {
2668		rs->ti->error = data_offset ? "No space for forward reshape" :
2669					      "No space for backward reshape";
2670		return -ENOSPC;
2671	}
2672out:
2673	/*
2674	 * Raise recovery_cp in case data_offset != 0 to
2675	 * avoid false recovery positives in the constructor.
2676	 */
2677	if (rs->md.recovery_cp < rs->md.dev_sectors)
2678		rs->md.recovery_cp += rs->dev[0].rdev.data_offset;
2679
2680	/* Adjust data offsets on all rdevs but on any raid4/5/6 journal device */
2681	rdev_for_each(rdev, &rs->md) {
2682		if (!test_bit(Journal, &rdev->flags)) {
2683			rdev->data_offset = data_offset;
2684			rdev->new_data_offset = new_data_offset;
2685		}
2686	}
2687
2688	return 0;
2689}
2690
2691/* Userpace reordered disks -> adjust raid_disk indexes in @rs */
2692static void __reorder_raid_disk_indexes(struct raid_set *rs)
2693{
2694	int i = 0;
2695	struct md_rdev *rdev;
2696
2697	rdev_for_each(rdev, &rs->md) {
2698		if (!test_bit(Journal, &rdev->flags)) {
2699			rdev->raid_disk = i++;
2700			rdev->saved_raid_disk = rdev->new_raid_disk = -1;
2701		}
2702	}
2703}
2704
2705/*
2706 * Setup @rs for takeover by a different raid level
2707 */
2708static int rs_setup_takeover(struct raid_set *rs)
2709{
2710	struct mddev *mddev = &rs->md;
2711	struct md_rdev *rdev;
2712	unsigned int d = mddev->raid_disks = rs->raid_disks;
2713	sector_t new_data_offset = rs->dev[0].rdev.data_offset ? 0 : rs->data_offset;
2714
2715	if (rt_is_raid10(rs->raid_type)) {
2716		if (rs_is_raid0(rs)) {
2717			/* Userpace reordered disks -> adjust raid_disk indexes */
2718			__reorder_raid_disk_indexes(rs);
2719
2720			/* raid0 -> raid10_far layout */
2721			mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_FAR,
2722								   rs->raid10_copies);
2723		} else if (rs_is_raid1(rs))
2724			/* raid1 -> raid10_near layout */
2725			mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_NEAR,
2726								   rs->raid_disks);
2727		else
2728			return -EINVAL;
2729
2730	}
2731
2732	clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
2733	mddev->recovery_cp = MaxSector;
2734
2735	while (d--) {
2736		rdev = &rs->dev[d].rdev;
2737
2738		if (test_bit(d, (void *) rs->rebuild_disks)) {
2739			clear_bit(In_sync, &rdev->flags);
2740			clear_bit(Faulty, &rdev->flags);
2741			mddev->recovery_cp = rdev->recovery_offset = 0;
2742			/* Bitmap has to be created when we do an "up" takeover */
2743			set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
2744		}
2745
2746		rdev->new_data_offset = new_data_offset;
2747	}
2748
2749	return 0;
2750}
2751
2752/* Prepare @rs for reshape */
2753static int rs_prepare_reshape(struct raid_set *rs)
2754{
2755	bool reshape;
2756	struct mddev *mddev = &rs->md;
2757
2758	if (rs_is_raid10(rs)) {
2759		if (rs->raid_disks != mddev->raid_disks &&
2760		    __is_raid10_near(mddev->layout) &&
2761		    rs->raid10_copies &&
2762		    rs->raid10_copies != __raid10_near_copies(mddev->layout)) {
2763			/*
2764			 * raid disk have to be multiple of data copies to allow this conversion,
2765			 *
2766			 * This is actually not a reshape it is a
2767			 * rebuild of any additional mirrors per group
2768			 */
2769			if (rs->raid_disks % rs->raid10_copies) {
2770				rs->ti->error = "Can't reshape raid10 mirror groups";
2771				return -EINVAL;
2772			}
2773
2774			/* Userpace reordered disks to add/remove mirrors -> adjust raid_disk indexes */
2775			__reorder_raid_disk_indexes(rs);
2776			mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_NEAR,
2777								   rs->raid10_copies);
2778			mddev->new_layout = mddev->layout;
2779			reshape = false;
2780		} else
2781			reshape = true;
2782
2783	} else if (rs_is_raid456(rs))
2784		reshape = true;
2785
2786	else if (rs_is_raid1(rs)) {
2787		if (rs->delta_disks) {
2788			/* Process raid1 via delta_disks */
2789			mddev->degraded = rs->delta_disks < 0 ? -rs->delta_disks : rs->delta_disks;
2790			reshape = true;
2791		} else {
2792			/* Process raid1 without delta_disks */
2793			mddev->raid_disks = rs->raid_disks;
2794			reshape = false;
2795		}
2796	} else {
2797		rs->ti->error = "Called with bogus raid type";
2798		return -EINVAL;
2799	}
2800
2801	if (reshape) {
2802		set_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags);
2803		set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2804	} else if (mddev->raid_disks < rs->raid_disks)
2805		/* Create new superblocks and bitmaps, if any new disks */
2806		set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2807
2808	return 0;
2809}
2810
2811/* Get reshape sectors from data_offsets or raid set */
2812static sector_t _get_reshape_sectors(struct raid_set *rs)
2813{
2814	struct md_rdev *rdev;
2815	sector_t reshape_sectors = 0;
2816
2817	rdev_for_each(rdev, &rs->md)
2818		if (!test_bit(Journal, &rdev->flags)) {
2819			reshape_sectors = (rdev->data_offset > rdev->new_data_offset) ?
2820					rdev->data_offset - rdev->new_data_offset :
2821					rdev->new_data_offset - rdev->data_offset;
2822			break;
2823		}
2824
2825	return max(reshape_sectors, (sector_t) rs->data_offset);
2826}
2827
2828/*
2829 * Reshape:
2830 * - change raid layout
2831 * - change chunk size
2832 * - add disks
2833 * - remove disks
2834 */
2835static int rs_setup_reshape(struct raid_set *rs)
2836{
2837	int r = 0;
2838	unsigned int cur_raid_devs, d;
2839	sector_t reshape_sectors = _get_reshape_sectors(rs);
2840	struct mddev *mddev = &rs->md;
2841	struct md_rdev *rdev;
2842
2843	mddev->delta_disks = rs->delta_disks;
2844	cur_raid_devs = mddev->raid_disks;
2845
2846	/* Ignore impossible layout change whilst adding/removing disks */
2847	if (mddev->delta_disks &&
2848	    mddev->layout != mddev->new_layout) {
2849		DMINFO("Ignoring invalid layout change with delta_disks=%d", rs->delta_disks);
2850		mddev->new_layout = mddev->layout;
2851	}
2852
2853	/*
2854	 * Adjust array size:
2855	 *
2856	 * - in case of adding disk(s), array size has
2857	 *   to grow after the disk adding reshape,
2858	 *   which'll hapen in the event handler;
2859	 *   reshape will happen forward, so space has to
2860	 *   be available at the beginning of each disk
2861	 *
2862	 * - in case of removing disk(s), array size
2863	 *   has to shrink before starting the reshape,
2864	 *   which'll happen here;
2865	 *   reshape will happen backward, so space has to
2866	 *   be available at the end of each disk
2867	 *
2868	 * - data_offset and new_data_offset are
2869	 *   adjusted for aforementioned out of place
2870	 *   reshaping based on userspace passing in
2871	 *   the "data_offset <sectors>" key/value
2872	 *   pair via the constructor
2873	 */
2874
2875	/* Add disk(s) */
2876	if (rs->delta_disks > 0) {
2877		/* Prepare disks for check in raid4/5/6/10 {check|start}_reshape */
2878		for (d = cur_raid_devs; d < rs->raid_disks; d++) {
2879			rdev = &rs->dev[d].rdev;
2880			clear_bit(In_sync, &rdev->flags);
2881
2882			/*
2883			 * save_raid_disk needs to be -1, or recovery_offset will be set to 0
2884			 * by md, which'll store that erroneously in the superblock on reshape
2885			 */
2886			rdev->saved_raid_disk = -1;
2887			rdev->raid_disk = d;
2888
2889			rdev->sectors = mddev->dev_sectors;
2890			rdev->recovery_offset = rs_is_raid1(rs) ? 0 : MaxSector;
2891		}
2892
2893		mddev->reshape_backwards = 0; /* adding disk(s) -> forward reshape */
2894
2895	/* Remove disk(s) */
2896	} else if (rs->delta_disks < 0) {
2897		r = rs_set_dev_and_array_sectors(rs, rs->ti->len, true);
2898		mddev->reshape_backwards = 1; /* removing disk(s) -> backward reshape */
2899
2900	/* Change layout and/or chunk size */
2901	} else {
2902		/*
2903		 * Reshape layout (e.g. raid5_ls -> raid5_n) and/or chunk size:
2904		 *
2905		 * keeping number of disks and do layout change ->
2906		 *
2907		 * toggle reshape_backward depending on data_offset:
2908		 *
2909		 * - free space upfront -> reshape forward
2910		 *
2911		 * - free space at the end -> reshape backward
2912		 *
2913		 *
2914		 * This utilizes free reshape space avoiding the need
2915		 * for userspace to move (parts of) LV segments in
2916		 * case of layout/chunksize change  (for disk
2917		 * adding/removing reshape space has to be at
2918		 * the proper address (see above with delta_disks):
2919		 *
2920		 * add disk(s)   -> begin
2921		 * remove disk(s)-> end
2922		 */
2923		mddev->reshape_backwards = rs->dev[0].rdev.data_offset ? 0 : 1;
2924	}
2925
2926	/*
2927	 * Adjust device size for forward reshape
2928	 * because md_finish_reshape() reduces it.
2929	 */
2930	if (!mddev->reshape_backwards)
2931		rdev_for_each(rdev, &rs->md)
2932			if (!test_bit(Journal, &rdev->flags))
2933				rdev->sectors += reshape_sectors;
2934
2935	return r;
2936}
2937
2938/*
2939 * If the md resync thread has updated superblock with max reshape position
2940 * at the end of a reshape but not (yet) reset the layout configuration
2941 * changes -> reset the latter.
2942 */
2943static void rs_reset_inconclusive_reshape(struct raid_set *rs)
2944{
2945	if (!rs_is_reshaping(rs) && rs_is_layout_change(rs, true)) {
2946		rs_set_cur(rs);
2947		rs->md.delta_disks = 0;
2948		rs->md.reshape_backwards = 0;
2949	}
2950}
2951
2952/*
2953 * Enable/disable discard support on RAID set depending on
2954 * RAID level and discard properties of underlying RAID members.
2955 */
2956static void configure_discard_support(struct raid_set *rs)
2957{
2958	int i;
2959	bool raid456;
2960	struct dm_target *ti = rs->ti;
2961
2962	/*
2963	 * XXX: RAID level 4,5,6 require zeroing for safety.
2964	 */
2965	raid456 = rs_is_raid456(rs);
2966
2967	for (i = 0; i < rs->raid_disks; i++) {
2968		if (!rs->dev[i].rdev.bdev ||
2969		    !bdev_max_discard_sectors(rs->dev[i].rdev.bdev))
 
 
 
 
 
2970			return;
2971
2972		if (raid456) {
2973			if (!devices_handle_discard_safely) {
2974				DMERR("raid456 discard support disabled due to discard_zeroes_data uncertainty.");
2975				DMERR("Set dm-raid.devices_handle_discard_safely=Y to override.");
2976				return;
2977			}
2978		}
2979	}
2980
2981	ti->num_discard_bios = 1;
2982}
2983
2984/*
2985 * Construct a RAID0/1/10/4/5/6 mapping:
2986 * Args:
2987 *	<raid_type> <#raid_params> <raid_params>{0,}	\
2988 *	<#raid_devs> [<meta_dev1> <dev1>]{1,}
2989 *
2990 * <raid_params> varies by <raid_type>.	 See 'parse_raid_params' for
2991 * details on possible <raid_params>.
2992 *
2993 * Userspace is free to initialize the metadata devices, hence the superblocks to
2994 * enforce recreation based on the passed in table parameters.
2995 *
2996 */
2997static int raid_ctr(struct dm_target *ti, unsigned int argc, char **argv)
2998{
2999	int r;
3000	bool resize = false;
3001	struct raid_type *rt;
3002	unsigned int num_raid_params, num_raid_devs;
3003	sector_t sb_array_sectors, rdev_sectors, reshape_sectors;
3004	struct raid_set *rs = NULL;
3005	const char *arg;
3006	struct rs_layout rs_layout;
3007	struct dm_arg_set as = { argc, argv }, as_nrd;
3008	struct dm_arg _args[] = {
3009		{ 0, as.argc, "Cannot understand number of raid parameters" },
3010		{ 1, 254, "Cannot understand number of raid devices parameters" }
3011	};
3012
3013	arg = dm_shift_arg(&as);
3014	if (!arg) {
3015		ti->error = "No arguments";
3016		return -EINVAL;
3017	}
3018
3019	rt = get_raid_type(arg);
3020	if (!rt) {
3021		ti->error = "Unrecognised raid_type";
3022		return -EINVAL;
3023	}
3024
3025	/* Must have <#raid_params> */
3026	if (dm_read_arg_group(_args, &as, &num_raid_params, &ti->error))
3027		return -EINVAL;
3028
3029	/* number of raid device tupples <meta_dev data_dev> */
3030	as_nrd = as;
3031	dm_consume_args(&as_nrd, num_raid_params);
3032	_args[1].max = (as_nrd.argc - 1) / 2;
3033	if (dm_read_arg(_args + 1, &as_nrd, &num_raid_devs, &ti->error))
3034		return -EINVAL;
3035
3036	if (!__within_range(num_raid_devs, 1, MAX_RAID_DEVICES)) {
3037		ti->error = "Invalid number of supplied raid devices";
3038		return -EINVAL;
3039	}
3040
3041	rs = raid_set_alloc(ti, rt, num_raid_devs);
3042	if (IS_ERR(rs))
3043		return PTR_ERR(rs);
3044
3045	r = parse_raid_params(rs, &as, num_raid_params);
3046	if (r)
3047		goto bad;
3048
3049	r = parse_dev_params(rs, &as);
3050	if (r)
3051		goto bad;
3052
3053	rs->md.sync_super = super_sync;
3054
3055	/*
3056	 * Calculate ctr requested array and device sizes to allow
3057	 * for superblock analysis needing device sizes defined.
3058	 *
3059	 * Any existing superblock will overwrite the array and device sizes
3060	 */
3061	r = rs_set_dev_and_array_sectors(rs, rs->ti->len, false);
3062	if (r)
3063		goto bad;
3064
3065	/* Memorize just calculated, potentially larger sizes to grow the raid set in preresume */
3066	rs->array_sectors = rs->md.array_sectors;
3067	rs->dev_sectors = rs->md.dev_sectors;
3068
3069	/*
3070	 * Backup any new raid set level, layout, ...
3071	 * requested to be able to compare to superblock
3072	 * members for conversion decisions.
3073	 */
3074	rs_config_backup(rs, &rs_layout);
3075
3076	r = analyse_superblocks(ti, rs);
3077	if (r)
3078		goto bad;
3079
3080	/* All in-core metadata now as of current superblocks after calling analyse_superblocks() */
3081	sb_array_sectors = rs->md.array_sectors;
3082	rdev_sectors = __rdev_sectors(rs);
3083	if (!rdev_sectors) {
3084		ti->error = "Invalid rdev size";
3085		r = -EINVAL;
3086		goto bad;
3087	}
3088
3089
3090	reshape_sectors = _get_reshape_sectors(rs);
3091	if (rs->dev_sectors != rdev_sectors) {
3092		resize = (rs->dev_sectors != rdev_sectors - reshape_sectors);
3093		if (rs->dev_sectors > rdev_sectors - reshape_sectors)
3094			set_bit(RT_FLAG_RS_GROW, &rs->runtime_flags);
3095	}
3096
3097	INIT_WORK(&rs->md.event_work, do_table_event);
3098	ti->private = rs;
3099	ti->num_flush_bios = 1;
3100	ti->needs_bio_set_dev = true;
3101
3102	/* Restore any requested new layout for conversion decision */
3103	rs_config_restore(rs, &rs_layout);
3104
3105	/*
3106	 * Now that we have any superblock metadata available,
3107	 * check for new, recovering, reshaping, to be taken over,
3108	 * to be reshaped or an existing, unchanged raid set to
3109	 * run in sequence.
3110	 */
3111	if (test_bit(MD_ARRAY_FIRST_USE, &rs->md.flags)) {
3112		/* A new raid6 set has to be recovered to ensure proper parity and Q-Syndrome */
3113		if (rs_is_raid6(rs) &&
3114		    test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
3115			ti->error = "'nosync' not allowed for new raid6 set";
3116			r = -EINVAL;
3117			goto bad;
3118		}
3119		rs_setup_recovery(rs, 0);
3120		set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
3121		rs_set_new(rs);
3122	} else if (rs_is_recovering(rs)) {
3123		/* A recovering raid set may be resized */
3124		goto size_check;
3125	} else if (rs_is_reshaping(rs)) {
3126		/* Have to reject size change request during reshape */
3127		if (resize) {
3128			ti->error = "Can't resize a reshaping raid set";
3129			r = -EPERM;
3130			goto bad;
3131		}
3132		/* skip setup rs */
3133	} else if (rs_takeover_requested(rs)) {
3134		if (rs_is_reshaping(rs)) {
3135			ti->error = "Can't takeover a reshaping raid set";
3136			r = -EPERM;
3137			goto bad;
3138		}
3139
3140		/* We can't takeover a journaled raid4/5/6 */
3141		if (test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
3142			ti->error = "Can't takeover a journaled raid4/5/6 set";
3143			r = -EPERM;
3144			goto bad;
3145		}
3146
3147		/*
3148		 * If a takeover is needed, userspace sets any additional
3149		 * devices to rebuild and we can check for a valid request here.
3150		 *
3151		 * If acceptible, set the level to the new requested
3152		 * one, prohibit requesting recovery, allow the raid
3153		 * set to run and store superblocks during resume.
3154		 */
3155		r = rs_check_takeover(rs);
3156		if (r)
3157			goto bad;
3158
3159		r = rs_setup_takeover(rs);
3160		if (r)
3161			goto bad;
3162
3163		set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
3164		/* Takeover ain't recovery, so disable recovery */
3165		rs_setup_recovery(rs, MaxSector);
3166		rs_set_new(rs);
3167	} else if (rs_reshape_requested(rs)) {
3168		/* Only request grow on raid set size extensions, not on reshapes. */
3169		clear_bit(RT_FLAG_RS_GROW, &rs->runtime_flags);
3170
3171		/*
3172		 * No need to check for 'ongoing' takeover here, because takeover
3173		 * is an instant operation as oposed to an ongoing reshape.
3174		 */
3175
3176		/* We can't reshape a journaled raid4/5/6 */
3177		if (test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
3178			ti->error = "Can't reshape a journaled raid4/5/6 set";
3179			r = -EPERM;
3180			goto bad;
3181		}
3182
3183		/* Out-of-place space has to be available to allow for a reshape unless raid1! */
3184		if (reshape_sectors || rs_is_raid1(rs)) {
3185			/*
3186			  * We can only prepare for a reshape here, because the
3187			  * raid set needs to run to provide the repective reshape
3188			  * check functions via its MD personality instance.
3189			  *
3190			  * So do the reshape check after md_run() succeeded.
3191			  */
3192			r = rs_prepare_reshape(rs);
3193			if (r)
3194				goto bad;
3195
3196			/* Reshaping ain't recovery, so disable recovery */
3197			rs_setup_recovery(rs, MaxSector);
3198		}
3199		rs_set_cur(rs);
3200	} else {
3201size_check:
3202		/* May not set recovery when a device rebuild is requested */
3203		if (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags)) {
3204			clear_bit(RT_FLAG_RS_GROW, &rs->runtime_flags);
3205			set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
3206			rs_setup_recovery(rs, MaxSector);
3207		} else if (test_bit(RT_FLAG_RS_GROW, &rs->runtime_flags)) {
3208			/*
3209			 * Set raid set to current size, i.e. size as of
3210			 * superblocks to grow to larger size in preresume.
3211			 */
3212			r = rs_set_dev_and_array_sectors(rs, sb_array_sectors, false);
3213			if (r)
3214				goto bad;
3215
3216			rs_setup_recovery(rs, rs->md.recovery_cp < rs->md.dev_sectors ? rs->md.recovery_cp : rs->md.dev_sectors);
3217		} else {
3218			/* This is no size change or it is shrinking, update size and record in superblocks */
3219			r = rs_set_dev_and_array_sectors(rs, rs->ti->len, false);
3220			if (r)
3221				goto bad;
3222
3223			if (sb_array_sectors > rs->array_sectors)
3224				set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
3225		}
3226		rs_set_cur(rs);
3227	}
3228
3229	/* If constructor requested it, change data and new_data offsets */
3230	r = rs_adjust_data_offsets(rs);
3231	if (r)
3232		goto bad;
3233
3234	/* Catch any inconclusive reshape superblock content. */
3235	rs_reset_inconclusive_reshape(rs);
3236
3237	/* Start raid set read-only and assumed clean to change in raid_resume() */
3238	rs->md.ro = 1;
3239	rs->md.in_sync = 1;
3240
3241	/* Keep array frozen until resume. */
3242	set_bit(MD_RECOVERY_FROZEN, &rs->md.recovery);
3243
3244	/* Has to be held on running the array */
3245	mddev_lock_nointr(&rs->md);
3246	r = md_run(&rs->md);
3247	rs->md.in_sync = 0; /* Assume already marked dirty */
3248	if (r) {
3249		ti->error = "Failed to run raid array";
3250		mddev_unlock(&rs->md);
3251		goto bad;
3252	}
3253
3254	r = md_start(&rs->md);
 
3255	if (r) {
3256		ti->error = "Failed to start raid array";
3257		mddev_unlock(&rs->md);
3258		goto bad_md_start;
3259	}
3260
3261	/* If raid4/5/6 journal mode explicitly requested (only possible with journal dev) -> set it */
3262	if (test_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags)) {
3263		r = r5c_journal_mode_set(&rs->md, rs->journal_dev.mode);
3264		if (r) {
3265			ti->error = "Failed to set raid4/5/6 journal mode";
3266			mddev_unlock(&rs->md);
3267			goto bad_journal_mode_set;
3268		}
3269	}
3270
3271	mddev_suspend(&rs->md);
3272	set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags);
3273
3274	/* Try to adjust the raid4/5/6 stripe cache size to the stripe size */
3275	if (rs_is_raid456(rs)) {
3276		r = rs_set_raid456_stripe_cache(rs);
3277		if (r)
3278			goto bad_stripe_cache;
3279	}
3280
3281	/* Now do an early reshape check */
3282	if (test_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags)) {
3283		r = rs_check_reshape(rs);
3284		if (r)
3285			goto bad_check_reshape;
3286
3287		/* Restore new, ctr requested layout to perform check */
3288		rs_config_restore(rs, &rs_layout);
3289
3290		if (rs->md.pers->start_reshape) {
3291			r = rs->md.pers->check_reshape(&rs->md);
3292			if (r) {
3293				ti->error = "Reshape check failed";
3294				goto bad_check_reshape;
3295			}
3296		}
3297	}
3298
3299	/* Disable/enable discard support on raid set. */
3300	configure_discard_support(rs);
3301
3302	mddev_unlock(&rs->md);
3303	return 0;
3304
3305bad_md_start:
3306bad_journal_mode_set:
3307bad_stripe_cache:
3308bad_check_reshape:
3309	md_stop(&rs->md);
3310bad:
3311	raid_set_free(rs);
3312
3313	return r;
3314}
3315
3316static void raid_dtr(struct dm_target *ti)
3317{
3318	struct raid_set *rs = ti->private;
3319
3320	md_stop(&rs->md);
3321	raid_set_free(rs);
3322}
3323
3324static int raid_map(struct dm_target *ti, struct bio *bio)
3325{
3326	struct raid_set *rs = ti->private;
3327	struct mddev *mddev = &rs->md;
3328
3329	/*
3330	 * If we're reshaping to add disk(s)), ti->len and
3331	 * mddev->array_sectors will differ during the process
3332	 * (ti->len > mddev->array_sectors), so we have to requeue
3333	 * bios with addresses > mddev->array_sectors here or
3334	 * there will occur accesses past EOD of the component
3335	 * data images thus erroring the raid set.
3336	 */
3337	if (unlikely(bio_end_sector(bio) > mddev->array_sectors))
3338		return DM_MAPIO_REQUEUE;
3339
3340	md_handle_request(mddev, bio);
3341
3342	return DM_MAPIO_SUBMITTED;
3343}
3344
3345/* Return sync state string for @state */
3346enum sync_state { st_frozen, st_reshape, st_resync, st_check, st_repair, st_recover, st_idle };
3347static const char *sync_str(enum sync_state state)
3348{
3349	/* Has to be in above sync_state order! */
3350	static const char *sync_strs[] = {
3351		"frozen",
3352		"reshape",
3353		"resync",
3354		"check",
3355		"repair",
3356		"recover",
3357		"idle"
3358	};
3359
3360	return __within_range(state, 0, ARRAY_SIZE(sync_strs) - 1) ? sync_strs[state] : "undef";
3361};
3362
3363/* Return enum sync_state for @mddev derived from @recovery flags */
3364static enum sync_state decipher_sync_action(struct mddev *mddev, unsigned long recovery)
3365{
3366	if (test_bit(MD_RECOVERY_FROZEN, &recovery))
3367		return st_frozen;
3368
3369	/* The MD sync thread can be done with io or be interrupted but still be running */
3370	if (!test_bit(MD_RECOVERY_DONE, &recovery) &&
3371	    (test_bit(MD_RECOVERY_RUNNING, &recovery) ||
3372	     (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &recovery)))) {
3373		if (test_bit(MD_RECOVERY_RESHAPE, &recovery))
3374			return st_reshape;
3375
3376		if (test_bit(MD_RECOVERY_SYNC, &recovery)) {
3377			if (!test_bit(MD_RECOVERY_REQUESTED, &recovery))
3378				return st_resync;
3379			if (test_bit(MD_RECOVERY_CHECK, &recovery))
3380				return st_check;
3381			return st_repair;
3382		}
3383
3384		if (test_bit(MD_RECOVERY_RECOVER, &recovery))
3385			return st_recover;
3386
3387		if (mddev->reshape_position != MaxSector)
3388			return st_reshape;
3389	}
3390
3391	return st_idle;
3392}
3393
3394/*
3395 * Return status string for @rdev
3396 *
3397 * Status characters:
3398 *
3399 *  'D' = Dead/Failed raid set component or raid4/5/6 journal device
3400 *  'a' = Alive but not in-sync raid set component _or_ alive raid4/5/6 'write_back' journal device
3401 *  'A' = Alive and in-sync raid set component _or_ alive raid4/5/6 'write_through' journal device
3402 *  '-' = Non-existing device (i.e. uspace passed '- -' into the ctr)
3403 */
3404static const char *__raid_dev_status(struct raid_set *rs, struct md_rdev *rdev)
3405{
3406	if (!rdev->bdev)
3407		return "-";
3408	else if (test_bit(Faulty, &rdev->flags))
3409		return "D";
3410	else if (test_bit(Journal, &rdev->flags))
3411		return (rs->journal_dev.mode == R5C_JOURNAL_MODE_WRITE_THROUGH) ? "A" : "a";
3412	else if (test_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags) ||
3413		 (!test_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags) &&
3414		  !test_bit(In_sync, &rdev->flags)))
3415		return "a";
3416	else
3417		return "A";
3418}
3419
3420/* Helper to return resync/reshape progress for @rs and runtime flags for raid set in sync / resynching */
3421static sector_t rs_get_progress(struct raid_set *rs, unsigned long recovery,
3422				enum sync_state state, sector_t resync_max_sectors)
3423{
3424	sector_t r;
3425	struct mddev *mddev = &rs->md;
3426
3427	clear_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3428	clear_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags);
3429
3430	if (rs_is_raid0(rs)) {
3431		r = resync_max_sectors;
3432		set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3433
3434	} else {
3435		if (state == st_idle && !test_bit(MD_RECOVERY_INTR, &recovery))
3436			r = mddev->recovery_cp;
3437		else
3438			r = mddev->curr_resync_completed;
3439
3440		if (state == st_idle && r >= resync_max_sectors) {
3441			/*
3442			 * Sync complete.
3443			 */
3444			/* In case we have finished recovering, the array is in sync. */
3445			if (test_bit(MD_RECOVERY_RECOVER, &recovery))
3446				set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3447
3448		} else if (state == st_recover)
3449			/*
3450			 * In case we are recovering, the array is not in sync
3451			 * and health chars should show the recovering legs.
3452			 *
3453			 * Already retrieved recovery offset from curr_resync_completed above.
3454			 */
3455			;
3456
3457		else if (state == st_resync || state == st_reshape)
3458			/*
3459			 * If "resync/reshape" is occurring, the raid set
3460			 * is or may be out of sync hence the health
3461			 * characters shall be 'a'.
3462			 */
3463			set_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags);
3464
3465		else if (state == st_check || state == st_repair)
3466			/*
3467			 * If "check" or "repair" is occurring, the raid set has
3468			 * undergone an initial sync and the health characters
3469			 * should not be 'a' anymore.
3470			 */
3471			set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3472
3473		else if (test_bit(MD_RECOVERY_NEEDED, &recovery))
3474			/*
3475			 * We are idle and recovery is needed, prevent 'A' chars race
3476			 * caused by components still set to in-sync by constructor.
3477			 */
3478			set_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags);
3479
3480		else {
3481			/*
3482			 * We are idle and the raid set may be doing an initial
3483			 * sync, or it may be rebuilding individual components.
3484			 * If all the devices are In_sync, then it is the raid set
3485			 * that is being initialized.
3486			 */
3487			struct md_rdev *rdev;
3488
3489			set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3490			rdev_for_each(rdev, mddev)
3491				if (!test_bit(Journal, &rdev->flags) &&
3492				    !test_bit(In_sync, &rdev->flags)) {
3493					clear_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3494					break;
3495				}
3496		}
3497	}
3498
3499	return min(r, resync_max_sectors);
3500}
3501
3502/* Helper to return @dev name or "-" if !@dev */
3503static const char *__get_dev_name(struct dm_dev *dev)
3504{
3505	return dev ? dev->name : "-";
3506}
3507
3508static void raid_status(struct dm_target *ti, status_type_t type,
3509			unsigned int status_flags, char *result, unsigned int maxlen)
3510{
3511	struct raid_set *rs = ti->private;
3512	struct mddev *mddev = &rs->md;
3513	struct r5conf *conf = rs_is_raid456(rs) ? mddev->private : NULL;
3514	int i, max_nr_stripes = conf ? conf->max_nr_stripes : 0;
3515	unsigned long recovery;
3516	unsigned int raid_param_cnt = 1; /* at least 1 for chunksize */
3517	unsigned int sz = 0;
3518	unsigned int rebuild_writemostly_count = 0;
3519	sector_t progress, resync_max_sectors, resync_mismatches;
3520	enum sync_state state;
3521	struct raid_type *rt;
3522
3523	switch (type) {
3524	case STATUSTYPE_INFO:
3525		/* *Should* always succeed */
3526		rt = get_raid_type_by_ll(mddev->new_level, mddev->new_layout);
3527		if (!rt)
3528			return;
3529
3530		DMEMIT("%s %d ", rt->name, mddev->raid_disks);
3531
3532		/* Access most recent mddev properties for status output */
3533		smp_rmb();
3534		/* Get sensible max sectors even if raid set not yet started */
3535		resync_max_sectors = test_bit(RT_FLAG_RS_PRERESUMED, &rs->runtime_flags) ?
3536				      mddev->resync_max_sectors : mddev->dev_sectors;
3537		recovery = rs->md.recovery;
3538		state = decipher_sync_action(mddev, recovery);
3539		progress = rs_get_progress(rs, recovery, state, resync_max_sectors);
3540		resync_mismatches = (mddev->last_sync_action && !strcasecmp(mddev->last_sync_action, "check")) ?
3541				    atomic64_read(&mddev->resync_mismatches) : 0;
3542
3543		/* HM FIXME: do we want another state char for raid0? It shows 'D'/'A'/'-' now */
3544		for (i = 0; i < rs->raid_disks; i++)
3545			DMEMIT(__raid_dev_status(rs, &rs->dev[i].rdev));
3546
3547		/*
3548		 * In-sync/Reshape ratio:
3549		 *  The in-sync ratio shows the progress of:
3550		 *   - Initializing the raid set
3551		 *   - Rebuilding a subset of devices of the raid set
3552		 *  The user can distinguish between the two by referring
3553		 *  to the status characters.
3554		 *
3555		 *  The reshape ratio shows the progress of
3556		 *  changing the raid layout or the number of
3557		 *  disks of a raid set
3558		 */
3559		DMEMIT(" %llu/%llu", (unsigned long long) progress,
3560				     (unsigned long long) resync_max_sectors);
3561
3562		/*
3563		 * v1.5.0+:
3564		 *
3565		 * Sync action:
3566		 *   See Documentation/admin-guide/device-mapper/dm-raid.rst for
3567		 *   information on each of these states.
3568		 */
3569		DMEMIT(" %s", sync_str(state));
3570
3571		/*
3572		 * v1.5.0+:
3573		 *
3574		 * resync_mismatches/mismatch_cnt
3575		 *   This field shows the number of discrepancies found when
3576		 *   performing a "check" of the raid set.
3577		 */
3578		DMEMIT(" %llu", (unsigned long long) resync_mismatches);
3579
3580		/*
3581		 * v1.9.0+:
3582		 *
3583		 * data_offset (needed for out of space reshaping)
3584		 *   This field shows the data offset into the data
3585		 *   image LV where the first stripes data starts.
3586		 *
3587		 * We keep data_offset equal on all raid disks of the set,
3588		 * so retrieving it from the first raid disk is sufficient.
3589		 */
3590		DMEMIT(" %llu", (unsigned long long) rs->dev[0].rdev.data_offset);
3591
3592		/*
3593		 * v1.10.0+:
3594		 */
3595		DMEMIT(" %s", test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags) ?
3596			      __raid_dev_status(rs, &rs->journal_dev.rdev) : "-");
3597		break;
3598
3599	case STATUSTYPE_TABLE:
3600		/* Report the table line string you would use to construct this raid set */
3601
3602		/*
3603		 * Count any rebuild or writemostly argument pairs and subtract the
3604		 * hweight count being added below of any rebuild and writemostly ctr flags.
3605		 */
3606		for (i = 0; i < rs->raid_disks; i++) {
3607			rebuild_writemostly_count += (test_bit(i, (void *) rs->rebuild_disks) ? 2 : 0) +
3608						     (test_bit(WriteMostly, &rs->dev[i].rdev.flags) ? 2 : 0);
3609		}
3610		rebuild_writemostly_count -= (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags) ? 2 : 0) +
3611					     (test_bit(__CTR_FLAG_WRITE_MOSTLY, &rs->ctr_flags) ? 2 : 0);
3612		/* Calculate raid parameter count based on ^ rebuild/writemostly argument counts and ctr flags set. */
3613		raid_param_cnt += rebuild_writemostly_count +
3614				  hweight32(rs->ctr_flags & CTR_FLAG_OPTIONS_NO_ARGS) +
3615				  hweight32(rs->ctr_flags & CTR_FLAG_OPTIONS_ONE_ARG) * 2;
3616		/* Emit table line */
3617		/* This has to be in the documented order for userspace! */
3618		DMEMIT("%s %u %u", rs->raid_type->name, raid_param_cnt, mddev->new_chunk_sectors);
3619		if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags))
3620			DMEMIT(" %s", dm_raid_arg_name_by_flag(CTR_FLAG_SYNC));
3621		if (test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))
3622			DMEMIT(" %s", dm_raid_arg_name_by_flag(CTR_FLAG_NOSYNC));
3623		if (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags))
3624			for (i = 0; i < rs->raid_disks; i++)
3625				if (test_bit(i, (void *) rs->rebuild_disks))
3626					DMEMIT(" %s %u", dm_raid_arg_name_by_flag(CTR_FLAG_REBUILD), i);
3627		if (test_bit(__CTR_FLAG_DAEMON_SLEEP, &rs->ctr_flags))
3628			DMEMIT(" %s %lu", dm_raid_arg_name_by_flag(CTR_FLAG_DAEMON_SLEEP),
3629					  mddev->bitmap_info.daemon_sleep);
3630		if (test_bit(__CTR_FLAG_MIN_RECOVERY_RATE, &rs->ctr_flags))
3631			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_MIN_RECOVERY_RATE),
3632					 mddev->sync_speed_min);
3633		if (test_bit(__CTR_FLAG_MAX_RECOVERY_RATE, &rs->ctr_flags))
3634			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_MAX_RECOVERY_RATE),
3635					 mddev->sync_speed_max);
3636		if (test_bit(__CTR_FLAG_WRITE_MOSTLY, &rs->ctr_flags))
3637			for (i = 0; i < rs->raid_disks; i++)
3638				if (test_bit(WriteMostly, &rs->dev[i].rdev.flags))
3639					DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_WRITE_MOSTLY),
3640					       rs->dev[i].rdev.raid_disk);
3641		if (test_bit(__CTR_FLAG_MAX_WRITE_BEHIND, &rs->ctr_flags))
3642			DMEMIT(" %s %lu", dm_raid_arg_name_by_flag(CTR_FLAG_MAX_WRITE_BEHIND),
3643					  mddev->bitmap_info.max_write_behind);
3644		if (test_bit(__CTR_FLAG_STRIPE_CACHE, &rs->ctr_flags))
3645			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_STRIPE_CACHE),
3646					 max_nr_stripes);
3647		if (test_bit(__CTR_FLAG_REGION_SIZE, &rs->ctr_flags))
3648			DMEMIT(" %s %llu", dm_raid_arg_name_by_flag(CTR_FLAG_REGION_SIZE),
3649					   (unsigned long long) to_sector(mddev->bitmap_info.chunksize));
3650		if (test_bit(__CTR_FLAG_RAID10_COPIES, &rs->ctr_flags))
3651			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_COPIES),
3652					 raid10_md_layout_to_copies(mddev->layout));
3653		if (test_bit(__CTR_FLAG_RAID10_FORMAT, &rs->ctr_flags))
3654			DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_FORMAT),
3655					 raid10_md_layout_to_format(mddev->layout));
3656		if (test_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags))
3657			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_DELTA_DISKS),
3658					 max(rs->delta_disks, mddev->delta_disks));
3659		if (test_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags))
3660			DMEMIT(" %s %llu", dm_raid_arg_name_by_flag(CTR_FLAG_DATA_OFFSET),
3661					   (unsigned long long) rs->data_offset);
3662		if (test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags))
3663			DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_DEV),
3664					__get_dev_name(rs->journal_dev.dev));
3665		if (test_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags))
3666			DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_MODE),
3667					 md_journal_mode_to_dm_raid(rs->journal_dev.mode));
3668		DMEMIT(" %d", rs->raid_disks);
3669		for (i = 0; i < rs->raid_disks; i++)
3670			DMEMIT(" %s %s", __get_dev_name(rs->dev[i].meta_dev),
3671					 __get_dev_name(rs->dev[i].data_dev));
3672		break;
3673
3674	case STATUSTYPE_IMA:
3675		rt = get_raid_type_by_ll(mddev->new_level, mddev->new_layout);
3676		if (!rt)
3677			return;
3678
3679		DMEMIT_TARGET_NAME_VERSION(ti->type);
3680		DMEMIT(",raid_type=%s,raid_disks=%d", rt->name, mddev->raid_disks);
3681
3682		/* Access most recent mddev properties for status output */
3683		smp_rmb();
3684		recovery = rs->md.recovery;
3685		state = decipher_sync_action(mddev, recovery);
3686		DMEMIT(",raid_state=%s", sync_str(state));
3687
3688		for (i = 0; i < rs->raid_disks; i++) {
3689			DMEMIT(",raid_device_%d_status=", i);
3690			DMEMIT(__raid_dev_status(rs, &rs->dev[i].rdev));
3691		}
3692
3693		if (rt_is_raid456(rt)) {
3694			DMEMIT(",journal_dev_mode=");
3695			switch (rs->journal_dev.mode) {
3696			case R5C_JOURNAL_MODE_WRITE_THROUGH:
3697				DMEMIT("%s",
3698				       _raid456_journal_mode[R5C_JOURNAL_MODE_WRITE_THROUGH].param);
3699				break;
3700			case R5C_JOURNAL_MODE_WRITE_BACK:
3701				DMEMIT("%s",
3702				       _raid456_journal_mode[R5C_JOURNAL_MODE_WRITE_BACK].param);
3703				break;
3704			default:
3705				DMEMIT("invalid");
3706				break;
3707			}
3708		}
3709		DMEMIT(";");
3710		break;
3711	}
3712}
3713
3714static int raid_message(struct dm_target *ti, unsigned int argc, char **argv,
3715			char *result, unsigned maxlen)
3716{
3717	struct raid_set *rs = ti->private;
3718	struct mddev *mddev = &rs->md;
3719
3720	if (!mddev->pers || !mddev->pers->sync_request)
3721		return -EINVAL;
3722
3723	if (!strcasecmp(argv[0], "frozen"))
3724		set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3725	else
3726		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3727
3728	if (!strcasecmp(argv[0], "idle") || !strcasecmp(argv[0], "frozen")) {
3729		if (mddev->sync_thread) {
3730			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
3731			md_unregister_thread(&mddev->sync_thread);
3732			md_reap_sync_thread(mddev);
3733		}
3734	} else if (decipher_sync_action(mddev, mddev->recovery) != st_idle)
3735		return -EBUSY;
3736	else if (!strcasecmp(argv[0], "resync"))
3737		; /* MD_RECOVERY_NEEDED set below */
3738	else if (!strcasecmp(argv[0], "recover"))
3739		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
3740	else {
3741		if (!strcasecmp(argv[0], "check")) {
3742			set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
3743			set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
3744			set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3745		} else if (!strcasecmp(argv[0], "repair")) {
3746			set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
3747			set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3748		} else
3749			return -EINVAL;
3750	}
3751	if (mddev->ro == 2) {
3752		/* A write to sync_action is enough to justify
3753		 * canceling read-auto mode
3754		 */
3755		mddev->ro = 0;
3756		if (!mddev->suspended && mddev->sync_thread)
3757			md_wakeup_thread(mddev->sync_thread);
3758	}
3759	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3760	if (!mddev->suspended && mddev->thread)
3761		md_wakeup_thread(mddev->thread);
3762
3763	return 0;
3764}
3765
3766static int raid_iterate_devices(struct dm_target *ti,
3767				iterate_devices_callout_fn fn, void *data)
3768{
3769	struct raid_set *rs = ti->private;
3770	unsigned int i;
3771	int r = 0;
3772
3773	for (i = 0; !r && i < rs->raid_disks; i++) {
3774		if (rs->dev[i].data_dev) {
3775			r = fn(ti, rs->dev[i].data_dev,
3776			       0, /* No offset on data devs */
3777			       rs->md.dev_sectors, data);
3778		}
3779	}
3780
3781	return r;
3782}
3783
3784static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
3785{
3786	struct raid_set *rs = ti->private;
3787	unsigned int chunk_size_bytes = to_bytes(rs->md.chunk_sectors);
3788
3789	blk_limits_io_min(limits, chunk_size_bytes);
3790	blk_limits_io_opt(limits, chunk_size_bytes * mddev_data_stripes(rs));
 
 
 
 
 
 
 
 
 
3791}
3792
3793static void raid_postsuspend(struct dm_target *ti)
3794{
3795	struct raid_set *rs = ti->private;
3796
3797	if (!test_and_set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) {
3798		/* Writes have to be stopped before suspending to avoid deadlocks. */
3799		if (!test_bit(MD_RECOVERY_FROZEN, &rs->md.recovery))
3800			md_stop_writes(&rs->md);
3801
3802		mddev_lock_nointr(&rs->md);
3803		mddev_suspend(&rs->md);
3804		mddev_unlock(&rs->md);
3805	}
3806}
3807
3808static void attempt_restore_of_faulty_devices(struct raid_set *rs)
3809{
3810	int i;
3811	uint64_t cleared_failed_devices[DISKS_ARRAY_ELEMS];
3812	unsigned long flags;
3813	bool cleared = false;
3814	struct dm_raid_superblock *sb;
3815	struct mddev *mddev = &rs->md;
3816	struct md_rdev *r;
3817
3818	/* RAID personalities have to provide hot add/remove methods or we need to bail out. */
3819	if (!mddev->pers || !mddev->pers->hot_add_disk || !mddev->pers->hot_remove_disk)
3820		return;
3821
3822	memset(cleared_failed_devices, 0, sizeof(cleared_failed_devices));
3823
3824	for (i = 0; i < rs->raid_disks; i++) {
3825		r = &rs->dev[i].rdev;
3826		/* HM FIXME: enhance journal device recovery processing */
3827		if (test_bit(Journal, &r->flags))
3828			continue;
3829
3830		if (test_bit(Faulty, &r->flags) &&
3831		    r->meta_bdev && !read_disk_sb(r, r->sb_size, true)) {
3832			DMINFO("Faulty %s device #%d has readable super block."
3833			       "  Attempting to revive it.",
3834			       rs->raid_type->name, i);
3835
3836			/*
3837			 * Faulty bit may be set, but sometimes the array can
3838			 * be suspended before the personalities can respond
3839			 * by removing the device from the array (i.e. calling
3840			 * 'hot_remove_disk').	If they haven't yet removed
3841			 * the failed device, its 'raid_disk' number will be
3842			 * '>= 0' - meaning we must call this function
3843			 * ourselves.
3844			 */
3845			flags = r->flags;
3846			clear_bit(In_sync, &r->flags); /* Mandatory for hot remove. */
3847			if (r->raid_disk >= 0) {
3848				if (mddev->pers->hot_remove_disk(mddev, r)) {
3849					/* Failed to revive this device, try next */
3850					r->flags = flags;
3851					continue;
3852				}
3853			} else
3854				r->raid_disk = r->saved_raid_disk = i;
3855
3856			clear_bit(Faulty, &r->flags);
3857			clear_bit(WriteErrorSeen, &r->flags);
3858
3859			if (mddev->pers->hot_add_disk(mddev, r)) {
3860				/* Failed to revive this device, try next */
3861				r->raid_disk = r->saved_raid_disk = -1;
3862				r->flags = flags;
3863			} else {
3864				clear_bit(In_sync, &r->flags);
3865				r->recovery_offset = 0;
3866				set_bit(i, (void *) cleared_failed_devices);
3867				cleared = true;
3868			}
3869		}
3870	}
3871
3872	/* If any failed devices could be cleared, update all sbs failed_devices bits */
3873	if (cleared) {
3874		uint64_t failed_devices[DISKS_ARRAY_ELEMS];
3875
3876		rdev_for_each(r, &rs->md) {
3877			if (test_bit(Journal, &r->flags))
3878				continue;
3879
3880			sb = page_address(r->sb_page);
3881			sb_retrieve_failed_devices(sb, failed_devices);
3882
3883			for (i = 0; i < DISKS_ARRAY_ELEMS; i++)
3884				failed_devices[i] &= ~cleared_failed_devices[i];
3885
3886			sb_update_failed_devices(sb, failed_devices);
3887		}
3888	}
3889}
3890
3891static int __load_dirty_region_bitmap(struct raid_set *rs)
3892{
3893	int r = 0;
3894
3895	/* Try loading the bitmap unless "raid0", which does not have one */
3896	if (!rs_is_raid0(rs) &&
3897	    !test_and_set_bit(RT_FLAG_RS_BITMAP_LOADED, &rs->runtime_flags)) {
3898		r = md_bitmap_load(&rs->md);
3899		if (r)
3900			DMERR("Failed to load bitmap");
3901	}
3902
3903	return r;
3904}
3905
3906/* Enforce updating all superblocks */
3907static void rs_update_sbs(struct raid_set *rs)
3908{
3909	struct mddev *mddev = &rs->md;
3910	int ro = mddev->ro;
3911
3912	set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
3913	mddev->ro = 0;
3914	md_update_sb(mddev, 1);
3915	mddev->ro = ro;
3916}
3917
3918/*
3919 * Reshape changes raid algorithm of @rs to new one within personality
3920 * (e.g. raid6_zr -> raid6_nc), changes stripe size, adds/removes
3921 * disks from a raid set thus growing/shrinking it or resizes the set
3922 *
3923 * Call mddev_lock_nointr() before!
3924 */
3925static int rs_start_reshape(struct raid_set *rs)
3926{
3927	int r;
3928	struct mddev *mddev = &rs->md;
3929	struct md_personality *pers = mddev->pers;
3930
3931	/* Don't allow the sync thread to work until the table gets reloaded. */
3932	set_bit(MD_RECOVERY_WAIT, &mddev->recovery);
3933
3934	r = rs_setup_reshape(rs);
3935	if (r)
3936		return r;
3937
3938	/*
3939	 * Check any reshape constraints enforced by the personalility
3940	 *
3941	 * May as well already kick the reshape off so that * pers->start_reshape() becomes optional.
3942	 */
3943	r = pers->check_reshape(mddev);
3944	if (r) {
3945		rs->ti->error = "pers->check_reshape() failed";
3946		return r;
3947	}
3948
3949	/*
3950	 * Personality may not provide start reshape method in which
3951	 * case check_reshape above has already covered everything
3952	 */
3953	if (pers->start_reshape) {
3954		r = pers->start_reshape(mddev);
3955		if (r) {
3956			rs->ti->error = "pers->start_reshape() failed";
3957			return r;
3958		}
3959	}
3960
3961	/*
3962	 * Now reshape got set up, update superblocks to
3963	 * reflect the fact so that a table reload will
3964	 * access proper superblock content in the ctr.
3965	 */
3966	rs_update_sbs(rs);
3967
3968	return 0;
3969}
3970
3971static int raid_preresume(struct dm_target *ti)
3972{
3973	int r;
3974	struct raid_set *rs = ti->private;
3975	struct mddev *mddev = &rs->md;
3976
3977	/* This is a resume after a suspend of the set -> it's already started. */
3978	if (test_and_set_bit(RT_FLAG_RS_PRERESUMED, &rs->runtime_flags))
3979		return 0;
3980
3981	/*
3982	 * The superblocks need to be updated on disk if the
3983	 * array is new or new devices got added (thus zeroed
3984	 * out by userspace) or __load_dirty_region_bitmap
3985	 * will overwrite them in core with old data or fail.
3986	 */
3987	if (test_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags))
3988		rs_update_sbs(rs);
3989
3990	/* Load the bitmap from disk unless raid0 */
3991	r = __load_dirty_region_bitmap(rs);
3992	if (r)
3993		return r;
3994
3995	/* We are extending the raid set size, adjust mddev/md_rdev sizes and set capacity. */
3996	if (test_bit(RT_FLAG_RS_GROW, &rs->runtime_flags)) {
3997		mddev->array_sectors = rs->array_sectors;
3998		mddev->dev_sectors = rs->dev_sectors;
3999		rs_set_rdev_sectors(rs);
4000		rs_set_capacity(rs);
4001	}
4002
4003	/* Resize bitmap to adjust to changed region size (aka MD bitmap chunksize) or grown device size */
4004        if (test_bit(RT_FLAG_RS_BITMAP_LOADED, &rs->runtime_flags) && mddev->bitmap &&
4005	    (test_bit(RT_FLAG_RS_GROW, &rs->runtime_flags) ||
4006	     (rs->requested_bitmap_chunk_sectors &&
4007	       mddev->bitmap_info.chunksize != to_bytes(rs->requested_bitmap_chunk_sectors)))) {
4008		int chunksize = to_bytes(rs->requested_bitmap_chunk_sectors) ?: mddev->bitmap_info.chunksize;
4009
4010		r = md_bitmap_resize(mddev->bitmap, mddev->dev_sectors, chunksize, 0);
4011		if (r)
4012			DMERR("Failed to resize bitmap");
4013	}
4014
4015	/* Check for any resize/reshape on @rs and adjust/initiate */
4016	/* Be prepared for mddev_resume() in raid_resume() */
4017	set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4018	if (mddev->recovery_cp && mddev->recovery_cp < MaxSector) {
4019		set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
4020		mddev->resync_min = mddev->recovery_cp;
4021		if (test_bit(RT_FLAG_RS_GROW, &rs->runtime_flags))
4022			mddev->resync_max_sectors = mddev->dev_sectors;
4023	}
4024
4025	/* Check for any reshape request unless new raid set */
4026	if (test_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags)) {
4027		/* Initiate a reshape. */
4028		rs_set_rdev_sectors(rs);
4029		mddev_lock_nointr(mddev);
4030		r = rs_start_reshape(rs);
4031		mddev_unlock(mddev);
4032		if (r)
4033			DMWARN("Failed to check/start reshape, continuing without change");
4034		r = 0;
4035	}
4036
4037	return r;
4038}
4039
4040static void raid_resume(struct dm_target *ti)
4041{
4042	struct raid_set *rs = ti->private;
4043	struct mddev *mddev = &rs->md;
4044
4045	if (test_and_set_bit(RT_FLAG_RS_RESUMED, &rs->runtime_flags)) {
4046		/*
4047		 * A secondary resume while the device is active.
4048		 * Take this opportunity to check whether any failed
4049		 * devices are reachable again.
4050		 */
4051		attempt_restore_of_faulty_devices(rs);
4052	}
4053
4054	if (test_and_clear_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) {
4055		/* Only reduce raid set size before running a disk removing reshape. */
4056		if (mddev->delta_disks < 0)
4057			rs_set_capacity(rs);
4058
4059		mddev_lock_nointr(mddev);
4060		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4061		mddev->ro = 0;
4062		mddev->in_sync = 0;
4063		mddev_resume(mddev);
4064		mddev_unlock(mddev);
4065	}
4066}
4067
4068static struct target_type raid_target = {
4069	.name = "raid",
4070	.version = {1, 15, 1},
4071	.module = THIS_MODULE,
4072	.ctr = raid_ctr,
4073	.dtr = raid_dtr,
4074	.map = raid_map,
4075	.status = raid_status,
4076	.message = raid_message,
4077	.iterate_devices = raid_iterate_devices,
4078	.io_hints = raid_io_hints,
4079	.postsuspend = raid_postsuspend,
4080	.preresume = raid_preresume,
4081	.resume = raid_resume,
4082};
4083
4084static int __init dm_raid_init(void)
4085{
4086	DMINFO("Loading target version %u.%u.%u",
4087	       raid_target.version[0],
4088	       raid_target.version[1],
4089	       raid_target.version[2]);
4090	return dm_register_target(&raid_target);
4091}
4092
4093static void __exit dm_raid_exit(void)
4094{
4095	dm_unregister_target(&raid_target);
4096}
4097
4098module_init(dm_raid_init);
4099module_exit(dm_raid_exit);
4100
4101module_param(devices_handle_discard_safely, bool, 0644);
4102MODULE_PARM_DESC(devices_handle_discard_safely,
4103		 "Set to Y if all devices in each array reliably return zeroes on reads from discarded regions");
4104
4105MODULE_DESCRIPTION(DM_NAME " raid0/1/10/4/5/6 target");
4106MODULE_ALIAS("dm-raid0");
4107MODULE_ALIAS("dm-raid1");
4108MODULE_ALIAS("dm-raid10");
4109MODULE_ALIAS("dm-raid4");
4110MODULE_ALIAS("dm-raid5");
4111MODULE_ALIAS("dm-raid6");
4112MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>");
4113MODULE_AUTHOR("Heinz Mauelshagen <dm-devel@redhat.com>");
4114MODULE_LICENSE("GPL");
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");