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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");
v4.17
   1/*
   2 * Copyright (C) 2010-2011 Neil Brown
   3 * Copyright (C) 2010-2017 Red Hat, Inc. All rights reserved.
   4 *
   5 * This file is released under the GPL.
   6 */
   7
   8#include <linux/slab.h>
   9#include <linux/module.h>
  10
  11#include "md.h"
  12#include "raid1.h"
  13#include "raid5.h"
  14#include "raid10.h"
  15#include "md-bitmap.h"
  16
  17#include <linux/device-mapper.h>
  18
  19#define DM_MSG_PREFIX "raid"
  20#define	MAX_RAID_DEVICES	253 /* md-raid kernel limit */
  21
  22/*
  23 * Minimum sectors of free reshape space per raid device
  24 */
  25#define	MIN_FREE_RESHAPE_SPACE to_sector(4*4096)
  26
  27/*
  28 * Minimum journal space 4 MiB in sectors.
  29 */
  30#define	MIN_RAID456_JOURNAL_SPACE (4*2048)
  31
  32/* Global list of all raid sets */
  33static LIST_HEAD(raid_sets);
  34
  35static bool devices_handle_discard_safely = false;
  36
  37/*
  38 * The following flags are used by dm-raid.c to set up the array state.
  39 * They must be cleared before md_run is called.
  40 */
  41#define FirstUse 10		/* rdev flag */
  42
  43struct raid_dev {
  44	/*
  45	 * Two DM devices, one to hold metadata and one to hold the
  46	 * actual data/parity.	The reason for this is to not confuse
  47	 * ti->len and give more flexibility in altering size and
  48	 * characteristics.
  49	 *
  50	 * While it is possible for this device to be associated
  51	 * with a different physical device than the data_dev, it
  52	 * is intended for it to be the same.
  53	 *    |--------- Physical Device ---------|
  54	 *    |- meta_dev -|------ data_dev ------|
  55	 */
  56	struct dm_dev *meta_dev;
  57	struct dm_dev *data_dev;
  58	struct md_rdev rdev;
  59};
  60
  61/*
  62 * Bits for establishing rs->ctr_flags
  63 *
  64 * 1 = no flag value
  65 * 2 = flag with value
  66 */
  67#define __CTR_FLAG_SYNC			0  /* 1 */ /* Not with raid0! */
  68#define __CTR_FLAG_NOSYNC		1  /* 1 */ /* Not with raid0! */
  69#define __CTR_FLAG_REBUILD		2  /* 2 */ /* Not with raid0! */
  70#define __CTR_FLAG_DAEMON_SLEEP		3  /* 2 */ /* Not with raid0! */
  71#define __CTR_FLAG_MIN_RECOVERY_RATE	4  /* 2 */ /* Not with raid0! */
  72#define __CTR_FLAG_MAX_RECOVERY_RATE	5  /* 2 */ /* Not with raid0! */
  73#define __CTR_FLAG_MAX_WRITE_BEHIND	6  /* 2 */ /* Only with raid1! */
  74#define __CTR_FLAG_WRITE_MOSTLY		7  /* 2 */ /* Only with raid1! */
  75#define __CTR_FLAG_STRIPE_CACHE		8  /* 2 */ /* Only with raid4/5/6! */
  76#define __CTR_FLAG_REGION_SIZE		9  /* 2 */ /* Not with raid0! */
  77#define __CTR_FLAG_RAID10_COPIES	10 /* 2 */ /* Only with raid10 */
  78#define __CTR_FLAG_RAID10_FORMAT	11 /* 2 */ /* Only with raid10 */
  79/* New for v1.9.0 */
  80#define __CTR_FLAG_DELTA_DISKS		12 /* 2 */ /* Only with reshapable raid1/4/5/6/10! */
  81#define __CTR_FLAG_DATA_OFFSET		13 /* 2 */ /* Only with reshapable raid4/5/6/10! */
  82#define __CTR_FLAG_RAID10_USE_NEAR_SETS 14 /* 2 */ /* Only with raid10! */
  83
  84/* New for v1.10.0 */
  85#define __CTR_FLAG_JOURNAL_DEV		15 /* 2 */ /* Only with raid4/5/6 (journal device)! */
  86
  87/* New for v1.11.1 */
  88#define __CTR_FLAG_JOURNAL_MODE		16 /* 2 */ /* Only with raid4/5/6 (journal mode)! */
  89
  90/*
  91 * Flags for rs->ctr_flags field.
  92 */
  93#define CTR_FLAG_SYNC			(1 << __CTR_FLAG_SYNC)
  94#define CTR_FLAG_NOSYNC			(1 << __CTR_FLAG_NOSYNC)
  95#define CTR_FLAG_REBUILD		(1 << __CTR_FLAG_REBUILD)
  96#define CTR_FLAG_DAEMON_SLEEP		(1 << __CTR_FLAG_DAEMON_SLEEP)
  97#define CTR_FLAG_MIN_RECOVERY_RATE	(1 << __CTR_FLAG_MIN_RECOVERY_RATE)
  98#define CTR_FLAG_MAX_RECOVERY_RATE	(1 << __CTR_FLAG_MAX_RECOVERY_RATE)
  99#define CTR_FLAG_MAX_WRITE_BEHIND	(1 << __CTR_FLAG_MAX_WRITE_BEHIND)
 100#define CTR_FLAG_WRITE_MOSTLY		(1 << __CTR_FLAG_WRITE_MOSTLY)
 101#define CTR_FLAG_STRIPE_CACHE		(1 << __CTR_FLAG_STRIPE_CACHE)
 102#define CTR_FLAG_REGION_SIZE		(1 << __CTR_FLAG_REGION_SIZE)
 103#define CTR_FLAG_RAID10_COPIES		(1 << __CTR_FLAG_RAID10_COPIES)
 104#define CTR_FLAG_RAID10_FORMAT		(1 << __CTR_FLAG_RAID10_FORMAT)
 105#define CTR_FLAG_DELTA_DISKS		(1 << __CTR_FLAG_DELTA_DISKS)
 106#define CTR_FLAG_DATA_OFFSET		(1 << __CTR_FLAG_DATA_OFFSET)
 107#define CTR_FLAG_RAID10_USE_NEAR_SETS	(1 << __CTR_FLAG_RAID10_USE_NEAR_SETS)
 108#define CTR_FLAG_JOURNAL_DEV		(1 << __CTR_FLAG_JOURNAL_DEV)
 109#define CTR_FLAG_JOURNAL_MODE		(1 << __CTR_FLAG_JOURNAL_MODE)
 110
 111/*
 112 * Definitions of various constructor flags to
 113 * be used in checks of valid / invalid flags
 114 * per raid level.
 115 */
 116/* Define all any sync flags */
 117#define	CTR_FLAGS_ANY_SYNC		(CTR_FLAG_SYNC | CTR_FLAG_NOSYNC)
 118
 119/* Define flags for options without argument (e.g. 'nosync') */
 120#define	CTR_FLAG_OPTIONS_NO_ARGS	(CTR_FLAGS_ANY_SYNC | \
 121					 CTR_FLAG_RAID10_USE_NEAR_SETS)
 122
 123/* Define flags for options with one argument (e.g. 'delta_disks +2') */
 124#define CTR_FLAG_OPTIONS_ONE_ARG (CTR_FLAG_REBUILD | \
 125				  CTR_FLAG_WRITE_MOSTLY | \
 126				  CTR_FLAG_DAEMON_SLEEP | \
 127				  CTR_FLAG_MIN_RECOVERY_RATE | \
 128				  CTR_FLAG_MAX_RECOVERY_RATE | \
 129				  CTR_FLAG_MAX_WRITE_BEHIND | \
 130				  CTR_FLAG_STRIPE_CACHE | \
 131				  CTR_FLAG_REGION_SIZE | \
 132				  CTR_FLAG_RAID10_COPIES | \
 133				  CTR_FLAG_RAID10_FORMAT | \
 134				  CTR_FLAG_DELTA_DISKS | \
 135				  CTR_FLAG_DATA_OFFSET)
 
 
 136
 137/* Valid options definitions per raid level... */
 138
 139/* "raid0" does only accept data offset */
 140#define RAID0_VALID_FLAGS	(CTR_FLAG_DATA_OFFSET)
 141
 142/* "raid1" does not accept stripe cache, data offset, delta_disks or any raid10 options */
 143#define RAID1_VALID_FLAGS	(CTR_FLAGS_ANY_SYNC | \
 144				 CTR_FLAG_REBUILD | \
 145				 CTR_FLAG_WRITE_MOSTLY | \
 146				 CTR_FLAG_DAEMON_SLEEP | \
 147				 CTR_FLAG_MIN_RECOVERY_RATE | \
 148				 CTR_FLAG_MAX_RECOVERY_RATE | \
 149				 CTR_FLAG_MAX_WRITE_BEHIND | \
 150				 CTR_FLAG_REGION_SIZE | \
 151				 CTR_FLAG_DELTA_DISKS | \
 152				 CTR_FLAG_DATA_OFFSET)
 153
 154/* "raid10" does not accept any raid1 or stripe cache options */
 155#define RAID10_VALID_FLAGS	(CTR_FLAGS_ANY_SYNC | \
 156				 CTR_FLAG_REBUILD | \
 157				 CTR_FLAG_DAEMON_SLEEP | \
 158				 CTR_FLAG_MIN_RECOVERY_RATE | \
 159				 CTR_FLAG_MAX_RECOVERY_RATE | \
 160				 CTR_FLAG_REGION_SIZE | \
 161				 CTR_FLAG_RAID10_COPIES | \
 162				 CTR_FLAG_RAID10_FORMAT | \
 163				 CTR_FLAG_DELTA_DISKS | \
 164				 CTR_FLAG_DATA_OFFSET | \
 165				 CTR_FLAG_RAID10_USE_NEAR_SETS)
 166
 167/*
 168 * "raid4/5/6" do not accept any raid1 or raid10 specific options
 169 *
 170 * "raid6" does not accept "nosync", because it is not guaranteed
 171 * that both parity and q-syndrome are being written properly with
 172 * any writes
 173 */
 174#define RAID45_VALID_FLAGS	(CTR_FLAGS_ANY_SYNC | \
 175				 CTR_FLAG_REBUILD | \
 176				 CTR_FLAG_DAEMON_SLEEP | \
 177				 CTR_FLAG_MIN_RECOVERY_RATE | \
 178				 CTR_FLAG_MAX_RECOVERY_RATE | \
 179				 CTR_FLAG_STRIPE_CACHE | \
 180				 CTR_FLAG_REGION_SIZE | \
 181				 CTR_FLAG_DELTA_DISKS | \
 182				 CTR_FLAG_DATA_OFFSET | \
 183				 CTR_FLAG_JOURNAL_DEV | \
 184				 CTR_FLAG_JOURNAL_MODE)
 185
 186#define RAID6_VALID_FLAGS	(CTR_FLAG_SYNC | \
 187				 CTR_FLAG_REBUILD | \
 188				 CTR_FLAG_DAEMON_SLEEP | \
 189				 CTR_FLAG_MIN_RECOVERY_RATE | \
 190				 CTR_FLAG_MAX_RECOVERY_RATE | \
 191				 CTR_FLAG_STRIPE_CACHE | \
 192				 CTR_FLAG_REGION_SIZE | \
 193				 CTR_FLAG_DELTA_DISKS | \
 194				 CTR_FLAG_DATA_OFFSET | \
 195				 CTR_FLAG_JOURNAL_DEV | \
 196				 CTR_FLAG_JOURNAL_MODE)
 197/* ...valid options definitions per raid level */
 198
 199/*
 200 * Flags for rs->runtime_flags field
 201 * (RT_FLAG prefix meaning "runtime flag")
 202 *
 203 * These are all internal and used to define runtime state,
 204 * e.g. to prevent another resume from preresume processing
 205 * the raid set all over again.
 206 */
 207#define RT_FLAG_RS_PRERESUMED		0
 208#define RT_FLAG_RS_RESUMED		1
 209#define RT_FLAG_RS_BITMAP_LOADED	2
 210#define RT_FLAG_UPDATE_SBS		3
 211#define RT_FLAG_RESHAPE_RS		4
 212#define RT_FLAG_RS_SUSPENDED		5
 213#define RT_FLAG_RS_IN_SYNC		6
 214#define RT_FLAG_RS_RESYNCING		7
 
 215
 216/* Array elements of 64 bit needed for rebuild/failed disk bits */
 217#define DISKS_ARRAY_ELEMS ((MAX_RAID_DEVICES + (sizeof(uint64_t) * 8 - 1)) / sizeof(uint64_t) / 8)
 218
 219/*
 220 * raid set level, layout and chunk sectors backup/restore
 221 */
 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	struct list_head list;
 231
 232	uint32_t stripe_cache_entries;
 233	unsigned long ctr_flags;
 234	unsigned long runtime_flags;
 235
 236	uint64_t rebuild_disks[DISKS_ARRAY_ELEMS];
 237
 238	int raid_disks;
 239	int delta_disks;
 240	int data_offset;
 241	int raid10_copies;
 242	int requested_bitmap_chunk_sectors;
 243
 244	struct mddev md;
 245	struct raid_type *raid_type;
 246	struct dm_target_callbacks callbacks;
 
 
 247
 248	/* Optional raid4/5/6 journal device */
 249	struct journal_dev {
 250		struct dm_dev *dev;
 251		struct md_rdev rdev;
 252		int mode;
 253	} journal_dev;
 254
 255	struct raid_dev dev[0];
 256};
 257
 258static void rs_config_backup(struct raid_set *rs, struct rs_layout *l)
 259{
 260	struct mddev *mddev = &rs->md;
 261
 262	l->new_level = mddev->new_level;
 263	l->new_layout = mddev->new_layout;
 264	l->new_chunk_sectors = mddev->new_chunk_sectors;
 265}
 266
 267static void rs_config_restore(struct raid_set *rs, struct rs_layout *l)
 268{
 269	struct mddev *mddev = &rs->md;
 270
 271	mddev->new_level = l->new_level;
 272	mddev->new_layout = l->new_layout;
 273	mddev->new_chunk_sectors = l->new_chunk_sectors;
 274}
 275
 276/* Find any raid_set in active slot for @rs on global list */
 277static struct raid_set *rs_find_active(struct raid_set *rs)
 278{
 279	struct raid_set *r;
 280	struct mapped_device *md = dm_table_get_md(rs->ti->table);
 281
 282	list_for_each_entry(r, &raid_sets, list)
 283		if (r != rs && dm_table_get_md(r->ti->table) == md)
 284			return r;
 285
 286	return NULL;
 287}
 288
 289/* raid10 algorithms (i.e. formats) */
 290#define	ALGORITHM_RAID10_DEFAULT	0
 291#define	ALGORITHM_RAID10_NEAR		1
 292#define	ALGORITHM_RAID10_OFFSET		2
 293#define	ALGORITHM_RAID10_FAR		3
 294
 295/* Supported raid types and properties. */
 296static struct raid_type {
 297	const char *name;		/* RAID algorithm. */
 298	const char *descr;		/* Descriptor text for logging. */
 299	const unsigned int parity_devs;	/* # of parity devices. */
 300	const unsigned int minimal_devs;/* minimal # of devices in set. */
 301	const unsigned int level;	/* RAID level. */
 302	const unsigned int algorithm;	/* RAID algorithm. */
 303} raid_types[] = {
 304	{"raid0",	  "raid0 (striping)",			    0, 2, 0,  0 /* NONE */},
 305	{"raid1",	  "raid1 (mirroring)",			    0, 2, 1,  0 /* NONE */},
 306	{"raid10_far",	  "raid10 far (striped mirrors)",	    0, 2, 10, ALGORITHM_RAID10_FAR},
 307	{"raid10_offset", "raid10 offset (striped mirrors)",	    0, 2, 10, ALGORITHM_RAID10_OFFSET},
 308	{"raid10_near",	  "raid10 near (striped mirrors)",	    0, 2, 10, ALGORITHM_RAID10_NEAR},
 309	{"raid10",	  "raid10 (striped mirrors)",		    0, 2, 10, ALGORITHM_RAID10_DEFAULT},
 310	{"raid4",	  "raid4 (dedicated first parity disk)",    1, 2, 5,  ALGORITHM_PARITY_0}, /* raid4 layout = raid5_0 */
 311	{"raid5_n",	  "raid5 (dedicated last parity disk)",	    1, 2, 5,  ALGORITHM_PARITY_N},
 312	{"raid5_ls",	  "raid5 (left symmetric)",		    1, 2, 5,  ALGORITHM_LEFT_SYMMETRIC},
 313	{"raid5_rs",	  "raid5 (right symmetric)",		    1, 2, 5,  ALGORITHM_RIGHT_SYMMETRIC},
 314	{"raid5_la",	  "raid5 (left asymmetric)",		    1, 2, 5,  ALGORITHM_LEFT_ASYMMETRIC},
 315	{"raid5_ra",	  "raid5 (right asymmetric)",		    1, 2, 5,  ALGORITHM_RIGHT_ASYMMETRIC},
 316	{"raid6_zr",	  "raid6 (zero restart)",		    2, 4, 6,  ALGORITHM_ROTATING_ZERO_RESTART},
 317	{"raid6_nr",	  "raid6 (N restart)",			    2, 4, 6,  ALGORITHM_ROTATING_N_RESTART},
 318	{"raid6_nc",	  "raid6 (N continue)",			    2, 4, 6,  ALGORITHM_ROTATING_N_CONTINUE},
 319	{"raid6_n_6",	  "raid6 (dedicated parity/Q n/6)",	    2, 4, 6,  ALGORITHM_PARITY_N_6},
 320	{"raid6_ls_6",	  "raid6 (left symmetric dedicated Q 6)",   2, 4, 6,  ALGORITHM_LEFT_SYMMETRIC_6},
 321	{"raid6_rs_6",	  "raid6 (right symmetric dedicated Q 6)",  2, 4, 6,  ALGORITHM_RIGHT_SYMMETRIC_6},
 322	{"raid6_la_6",	  "raid6 (left asymmetric dedicated Q 6)",  2, 4, 6,  ALGORITHM_LEFT_ASYMMETRIC_6},
 323	{"raid6_ra_6",	  "raid6 (right asymmetric dedicated Q 6)", 2, 4, 6,  ALGORITHM_RIGHT_ASYMMETRIC_6}
 324};
 325
 326/* True, if @v is in inclusive range [@min, @max] */
 327static bool __within_range(long v, long min, long max)
 328{
 329	return v >= min && v <= max;
 330}
 331
 332/* All table line arguments are defined here */
 333static struct arg_name_flag {
 334	const unsigned long flag;
 335	const char *name;
 336} __arg_name_flags[] = {
 337	{ CTR_FLAG_SYNC, "sync"},
 338	{ CTR_FLAG_NOSYNC, "nosync"},
 339	{ CTR_FLAG_REBUILD, "rebuild"},
 340	{ CTR_FLAG_DAEMON_SLEEP, "daemon_sleep"},
 341	{ CTR_FLAG_MIN_RECOVERY_RATE, "min_recovery_rate"},
 342	{ CTR_FLAG_MAX_RECOVERY_RATE, "max_recovery_rate"},
 343	{ CTR_FLAG_MAX_WRITE_BEHIND, "max_write_behind"},
 344	{ CTR_FLAG_WRITE_MOSTLY, "write_mostly"},
 345	{ CTR_FLAG_STRIPE_CACHE, "stripe_cache"},
 346	{ CTR_FLAG_REGION_SIZE, "region_size"},
 347	{ CTR_FLAG_RAID10_COPIES, "raid10_copies"},
 348	{ CTR_FLAG_RAID10_FORMAT, "raid10_format"},
 349	{ CTR_FLAG_DATA_OFFSET, "data_offset"},
 350	{ CTR_FLAG_DELTA_DISKS, "delta_disks"},
 351	{ CTR_FLAG_RAID10_USE_NEAR_SETS, "raid10_use_near_sets"},
 352	{ CTR_FLAG_JOURNAL_DEV, "journal_dev" },
 353	{ CTR_FLAG_JOURNAL_MODE, "journal_mode" },
 354};
 355
 356/* Return argument name string for given @flag */
 357static const char *dm_raid_arg_name_by_flag(const uint32_t flag)
 358{
 359	if (hweight32(flag) == 1) {
 360		struct arg_name_flag *anf = __arg_name_flags + ARRAY_SIZE(__arg_name_flags);
 361
 362		while (anf-- > __arg_name_flags)
 363			if (flag & anf->flag)
 364				return anf->name;
 365
 366	} else
 367		DMERR("%s called with more than one flag!", __func__);
 368
 369	return NULL;
 370}
 371
 372/* Define correlation of raid456 journal cache modes and dm-raid target line parameters */
 373static struct {
 374	const int mode;
 375	const char *param;
 376} _raid456_journal_mode[] = {
 377	{ R5C_JOURNAL_MODE_WRITE_THROUGH , "writethrough" },
 378	{ R5C_JOURNAL_MODE_WRITE_BACK    , "writeback" }
 379};
 380
 381/* Return MD raid4/5/6 journal mode for dm @journal_mode one */
 382static int dm_raid_journal_mode_to_md(const char *mode)
 383{
 384	int m = ARRAY_SIZE(_raid456_journal_mode);
 385
 386	while (m--)
 387		if (!strcasecmp(mode, _raid456_journal_mode[m].param))
 388			return _raid456_journal_mode[m].mode;
 389
 390	return -EINVAL;
 391}
 392
 393/* Return dm-raid raid4/5/6 journal mode string for @mode */
 394static const char *md_journal_mode_to_dm_raid(const int mode)
 395{
 396	int m = ARRAY_SIZE(_raid456_journal_mode);
 397
 398	while (m--)
 399		if (mode == _raid456_journal_mode[m].mode)
 400			return _raid456_journal_mode[m].param;
 401
 402	return "unknown";
 403}
 404
 405/*
 406 * Bool helpers to test for various raid levels of a raid set.
 407 * It's level as reported by the superblock rather than
 408 * the requested raid_type passed to the constructor.
 409 */
 410/* Return true, if raid set in @rs is raid0 */
 411static bool rs_is_raid0(struct raid_set *rs)
 412{
 413	return !rs->md.level;
 414}
 415
 416/* Return true, if raid set in @rs is raid1 */
 417static bool rs_is_raid1(struct raid_set *rs)
 418{
 419	return rs->md.level == 1;
 420}
 421
 422/* Return true, if raid set in @rs is raid10 */
 423static bool rs_is_raid10(struct raid_set *rs)
 424{
 425	return rs->md.level == 10;
 426}
 427
 428/* Return true, if raid set in @rs is level 6 */
 429static bool rs_is_raid6(struct raid_set *rs)
 430{
 431	return rs->md.level == 6;
 432}
 433
 434/* Return true, if raid set in @rs is level 4, 5 or 6 */
 435static bool rs_is_raid456(struct raid_set *rs)
 436{
 437	return __within_range(rs->md.level, 4, 6);
 438}
 439
 440/* Return true, if raid set in @rs is reshapable */
 441static bool __is_raid10_far(int layout);
 442static bool rs_is_reshapable(struct raid_set *rs)
 443{
 444	return rs_is_raid456(rs) ||
 445	       (rs_is_raid10(rs) && !__is_raid10_far(rs->md.new_layout));
 446}
 447
 448/* Return true, if raid set in @rs is recovering */
 449static bool rs_is_recovering(struct raid_set *rs)
 450{
 451	return rs->md.recovery_cp < rs->md.dev_sectors;
 452}
 453
 454/* Return true, if raid set in @rs is reshaping */
 455static bool rs_is_reshaping(struct raid_set *rs)
 456{
 457	return rs->md.reshape_position != MaxSector;
 458}
 459
 460/*
 461 * bool helpers to test for various raid levels of a raid type @rt
 462 */
 463
 464/* Return true, if raid type in @rt is raid0 */
 465static bool rt_is_raid0(struct raid_type *rt)
 466{
 467	return !rt->level;
 468}
 469
 470/* Return true, if raid type in @rt is raid1 */
 471static bool rt_is_raid1(struct raid_type *rt)
 472{
 473	return rt->level == 1;
 474}
 475
 476/* Return true, if raid type in @rt is raid10 */
 477static bool rt_is_raid10(struct raid_type *rt)
 478{
 479	return rt->level == 10;
 480}
 481
 482/* Return true, if raid type in @rt is raid4/5 */
 483static bool rt_is_raid45(struct raid_type *rt)
 484{
 485	return __within_range(rt->level, 4, 5);
 486}
 487
 488/* Return true, if raid type in @rt is raid6 */
 489static bool rt_is_raid6(struct raid_type *rt)
 490{
 491	return rt->level == 6;
 492}
 493
 494/* Return true, if raid type in @rt is raid4/5/6 */
 495static bool rt_is_raid456(struct raid_type *rt)
 496{
 497	return __within_range(rt->level, 4, 6);
 498}
 499/* END: raid level bools */
 500
 501/* Return valid ctr flags for the raid level of @rs */
 502static unsigned long __valid_flags(struct raid_set *rs)
 503{
 504	if (rt_is_raid0(rs->raid_type))
 505		return RAID0_VALID_FLAGS;
 506	else if (rt_is_raid1(rs->raid_type))
 507		return RAID1_VALID_FLAGS;
 508	else if (rt_is_raid10(rs->raid_type))
 509		return RAID10_VALID_FLAGS;
 510	else if (rt_is_raid45(rs->raid_type))
 511		return RAID45_VALID_FLAGS;
 512	else if (rt_is_raid6(rs->raid_type))
 513		return RAID6_VALID_FLAGS;
 514
 515	return 0;
 516}
 517
 518/*
 519 * Check for valid flags set on @rs
 520 *
 521 * Has to be called after parsing of the ctr flags!
 522 */
 523static int rs_check_for_valid_flags(struct raid_set *rs)
 524{
 525	if (rs->ctr_flags & ~__valid_flags(rs)) {
 526		rs->ti->error = "Invalid flags combination";
 527		return -EINVAL;
 528	}
 529
 530	return 0;
 531}
 532
 533/* MD raid10 bit definitions and helpers */
 534#define RAID10_OFFSET			(1 << 16) /* stripes with data copies area adjacent on devices */
 535#define RAID10_BROCKEN_USE_FAR_SETS	(1 << 17) /* Broken in raid10.c: use sets instead of whole stripe rotation */
 536#define RAID10_USE_FAR_SETS		(1 << 18) /* Use sets instead of whole stripe rotation */
 537#define RAID10_FAR_COPIES_SHIFT		8	  /* raid10 # far copies shift (2nd byte of layout) */
 538
 539/* Return md raid10 near copies for @layout */
 540static unsigned int __raid10_near_copies(int layout)
 541{
 542	return layout & 0xFF;
 543}
 544
 545/* Return md raid10 far copies for @layout */
 546static unsigned int __raid10_far_copies(int layout)
 547{
 548	return __raid10_near_copies(layout >> RAID10_FAR_COPIES_SHIFT);
 549}
 550
 551/* Return true if md raid10 offset for @layout */
 552static bool __is_raid10_offset(int layout)
 553{
 554	return !!(layout & RAID10_OFFSET);
 555}
 556
 557/* Return true if md raid10 near for @layout */
 558static bool __is_raid10_near(int layout)
 559{
 560	return !__is_raid10_offset(layout) && __raid10_near_copies(layout) > 1;
 561}
 562
 563/* Return true if md raid10 far for @layout */
 564static bool __is_raid10_far(int layout)
 565{
 566	return !__is_raid10_offset(layout) && __raid10_far_copies(layout) > 1;
 567}
 568
 569/* Return md raid10 layout string for @layout */
 570static const char *raid10_md_layout_to_format(int layout)
 571{
 572	/*
 573	 * Bit 16 stands for "offset"
 574	 * (i.e. adjacent stripes hold copies)
 575	 *
 576	 * Refer to MD's raid10.c for details
 577	 */
 578	if (__is_raid10_offset(layout))
 579		return "offset";
 580
 581	if (__raid10_near_copies(layout) > 1)
 582		return "near";
 583
 584	if (__raid10_far_copies(layout) > 1)
 585		return "far";
 586
 587	return "unknown";
 588}
 589
 590/* Return md raid10 algorithm for @name */
 591static const int raid10_name_to_format(const char *name)
 592{
 593	if (!strcasecmp(name, "near"))
 594		return ALGORITHM_RAID10_NEAR;
 595	else if (!strcasecmp(name, "offset"))
 596		return ALGORITHM_RAID10_OFFSET;
 597	else if (!strcasecmp(name, "far"))
 598		return ALGORITHM_RAID10_FAR;
 599
 600	return -EINVAL;
 601}
 602
 603/* Return md raid10 copies for @layout */
 604static unsigned int raid10_md_layout_to_copies(int layout)
 605{
 606	return max(__raid10_near_copies(layout), __raid10_far_copies(layout));
 607}
 608
 609/* Return md raid10 format id for @format string */
 610static int raid10_format_to_md_layout(struct raid_set *rs,
 611				      unsigned int algorithm,
 612				      unsigned int copies)
 613{
 614	unsigned int n = 1, f = 1, r = 0;
 615
 616	/*
 617	 * MD resilienece flaw:
 618	 *
 619	 * enabling use_far_sets for far/offset formats causes copies
 620	 * to be colocated on the same devs together with their origins!
 621	 *
 622	 * -> disable it for now in the definition above
 623	 */
 624	if (algorithm == ALGORITHM_RAID10_DEFAULT ||
 625	    algorithm == ALGORITHM_RAID10_NEAR)
 626		n = copies;
 627
 628	else if (algorithm == ALGORITHM_RAID10_OFFSET) {
 629		f = copies;
 630		r = RAID10_OFFSET;
 631		if (!test_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags))
 632			r |= RAID10_USE_FAR_SETS;
 633
 634	} else if (algorithm == ALGORITHM_RAID10_FAR) {
 635		f = copies;
 636		r = !RAID10_OFFSET;
 637		if (!test_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags))
 638			r |= RAID10_USE_FAR_SETS;
 639
 640	} else
 641		return -EINVAL;
 642
 643	return r | (f << RAID10_FAR_COPIES_SHIFT) | n;
 644}
 645/* END: MD raid10 bit definitions and helpers */
 646
 647/* Check for any of the raid10 algorithms */
 648static bool __got_raid10(struct raid_type *rtp, const int layout)
 649{
 650	if (rtp->level == 10) {
 651		switch (rtp->algorithm) {
 652		case ALGORITHM_RAID10_DEFAULT:
 653		case ALGORITHM_RAID10_NEAR:
 654			return __is_raid10_near(layout);
 655		case ALGORITHM_RAID10_OFFSET:
 656			return __is_raid10_offset(layout);
 657		case ALGORITHM_RAID10_FAR:
 658			return __is_raid10_far(layout);
 659		default:
 660			break;
 661		}
 662	}
 663
 664	return false;
 665}
 666
 667/* Return raid_type for @name */
 668static struct raid_type *get_raid_type(const char *name)
 669{
 670	struct raid_type *rtp = raid_types + ARRAY_SIZE(raid_types);
 671
 672	while (rtp-- > raid_types)
 673		if (!strcasecmp(rtp->name, name))
 674			return rtp;
 675
 676	return NULL;
 677}
 678
 679/* Return raid_type for @name based derived from @level and @layout */
 680static struct raid_type *get_raid_type_by_ll(const int level, const int layout)
 681{
 682	struct raid_type *rtp = raid_types + ARRAY_SIZE(raid_types);
 683
 684	while (rtp-- > raid_types) {
 685		/* RAID10 special checks based on @layout flags/properties */
 686		if (rtp->level == level &&
 687		    (__got_raid10(rtp, layout) || rtp->algorithm == layout))
 688			return rtp;
 689	}
 690
 691	return NULL;
 692}
 693
 694/* Adjust rdev sectors */
 695static void rs_set_rdev_sectors(struct raid_set *rs)
 696{
 697	struct mddev *mddev = &rs->md;
 698	struct md_rdev *rdev;
 699
 700	/*
 701	 * raid10 sets rdev->sector to the device size, which
 702	 * is unintended in case of out-of-place reshaping
 703	 */
 704	rdev_for_each(rdev, mddev)
 705		if (!test_bit(Journal, &rdev->flags))
 706			rdev->sectors = mddev->dev_sectors;
 707}
 708
 709/*
 710 * Change bdev capacity of @rs in case of a disk add/remove reshape
 711 */
 712static void rs_set_capacity(struct raid_set *rs)
 713{
 714	struct gendisk *gendisk = dm_disk(dm_table_get_md(rs->ti->table));
 715
 716	set_capacity(gendisk, rs->md.array_sectors);
 717	revalidate_disk(gendisk);
 718}
 719
 720/*
 721 * Set the mddev properties in @rs to the current
 722 * ones retrieved from the freshest superblock
 723 */
 724static void rs_set_cur(struct raid_set *rs)
 725{
 726	struct mddev *mddev = &rs->md;
 727
 728	mddev->new_level = mddev->level;
 729	mddev->new_layout = mddev->layout;
 730	mddev->new_chunk_sectors = mddev->chunk_sectors;
 731}
 732
 733/*
 734 * Set the mddev properties in @rs to the new
 735 * ones requested by the ctr
 736 */
 737static void rs_set_new(struct raid_set *rs)
 738{
 739	struct mddev *mddev = &rs->md;
 740
 741	mddev->level = mddev->new_level;
 742	mddev->layout = mddev->new_layout;
 743	mddev->chunk_sectors = mddev->new_chunk_sectors;
 744	mddev->raid_disks = rs->raid_disks;
 745	mddev->delta_disks = 0;
 746}
 747
 748static struct raid_set *raid_set_alloc(struct dm_target *ti, struct raid_type *raid_type,
 749				       unsigned int raid_devs)
 750{
 751	unsigned int i;
 752	struct raid_set *rs;
 753
 754	if (raid_devs <= raid_type->parity_devs) {
 755		ti->error = "Insufficient number of devices";
 756		return ERR_PTR(-EINVAL);
 757	}
 758
 759	rs = kzalloc(sizeof(*rs) + raid_devs * sizeof(rs->dev[0]), GFP_KERNEL);
 760	if (!rs) {
 761		ti->error = "Cannot allocate raid context";
 762		return ERR_PTR(-ENOMEM);
 763	}
 764
 765	mddev_init(&rs->md);
 766
 767	INIT_LIST_HEAD(&rs->list);
 768	rs->raid_disks = raid_devs;
 769	rs->delta_disks = 0;
 770
 771	rs->ti = ti;
 772	rs->raid_type = raid_type;
 773	rs->stripe_cache_entries = 256;
 774	rs->md.raid_disks = raid_devs;
 775	rs->md.level = raid_type->level;
 776	rs->md.new_level = rs->md.level;
 777	rs->md.layout = raid_type->algorithm;
 778	rs->md.new_layout = rs->md.layout;
 779	rs->md.delta_disks = 0;
 780	rs->md.recovery_cp = MaxSector;
 781
 782	for (i = 0; i < raid_devs; i++)
 783		md_rdev_init(&rs->dev[i].rdev);
 784
 785	/* Add @rs to global list. */
 786	list_add(&rs->list, &raid_sets);
 787
 788	/*
 789	 * Remaining items to be initialized by further RAID params:
 790	 *  rs->md.persistent
 791	 *  rs->md.external
 792	 *  rs->md.chunk_sectors
 793	 *  rs->md.new_chunk_sectors
 794	 *  rs->md.dev_sectors
 795	 */
 796
 797	return rs;
 798}
 799
 800/* Free all @rs allocations and remove it from global list. */
 801static void raid_set_free(struct raid_set *rs)
 802{
 803	int i;
 804
 805	if (rs->journal_dev.dev) {
 806		md_rdev_clear(&rs->journal_dev.rdev);
 807		dm_put_device(rs->ti, rs->journal_dev.dev);
 808	}
 809
 810	for (i = 0; i < rs->raid_disks; i++) {
 811		if (rs->dev[i].meta_dev)
 812			dm_put_device(rs->ti, rs->dev[i].meta_dev);
 813		md_rdev_clear(&rs->dev[i].rdev);
 814		if (rs->dev[i].data_dev)
 815			dm_put_device(rs->ti, rs->dev[i].data_dev);
 816	}
 817
 818	list_del(&rs->list);
 819
 820	kfree(rs);
 821}
 822
 823/*
 824 * For every device we have two words
 825 *  <meta_dev>: meta device name or '-' if missing
 826 *  <data_dev>: data device name or '-' if missing
 827 *
 828 * The following are permitted:
 829 *    - -
 830 *    - <data_dev>
 831 *    <meta_dev> <data_dev>
 832 *
 833 * The following is not allowed:
 834 *    <meta_dev> -
 835 *
 836 * This code parses those words.  If there is a failure,
 837 * the caller must use raid_set_free() to unwind the operations.
 838 */
 839static int parse_dev_params(struct raid_set *rs, struct dm_arg_set *as)
 840{
 841	int i;
 842	int rebuild = 0;
 843	int metadata_available = 0;
 844	int r = 0;
 845	const char *arg;
 846
 847	/* Put off the number of raid devices argument to get to dev pairs */
 848	arg = dm_shift_arg(as);
 849	if (!arg)
 850		return -EINVAL;
 851
 852	for (i = 0; i < rs->raid_disks; i++) {
 853		rs->dev[i].rdev.raid_disk = i;
 854
 855		rs->dev[i].meta_dev = NULL;
 856		rs->dev[i].data_dev = NULL;
 857
 858		/*
 859		 * There are no offsets initially.
 860		 * Out of place reshape will set them accordingly.
 861		 */
 862		rs->dev[i].rdev.data_offset = 0;
 863		rs->dev[i].rdev.new_data_offset = 0;
 864		rs->dev[i].rdev.mddev = &rs->md;
 865
 866		arg = dm_shift_arg(as);
 867		if (!arg)
 868			return -EINVAL;
 869
 870		if (strcmp(arg, "-")) {
 871			r = dm_get_device(rs->ti, arg, dm_table_get_mode(rs->ti->table),
 872					  &rs->dev[i].meta_dev);
 873			if (r) {
 874				rs->ti->error = "RAID metadata device lookup failure";
 875				return r;
 876			}
 877
 878			rs->dev[i].rdev.sb_page = alloc_page(GFP_KERNEL);
 879			if (!rs->dev[i].rdev.sb_page) {
 880				rs->ti->error = "Failed to allocate superblock page";
 881				return -ENOMEM;
 882			}
 883		}
 884
 885		arg = dm_shift_arg(as);
 886		if (!arg)
 887			return -EINVAL;
 888
 889		if (!strcmp(arg, "-")) {
 890			if (!test_bit(In_sync, &rs->dev[i].rdev.flags) &&
 891			    (!rs->dev[i].rdev.recovery_offset)) {
 892				rs->ti->error = "Drive designated for rebuild not specified";
 893				return -EINVAL;
 894			}
 895
 896			if (rs->dev[i].meta_dev) {
 897				rs->ti->error = "No data device supplied with metadata device";
 898				return -EINVAL;
 899			}
 900
 901			continue;
 902		}
 903
 904		r = dm_get_device(rs->ti, arg, dm_table_get_mode(rs->ti->table),
 905				  &rs->dev[i].data_dev);
 906		if (r) {
 907			rs->ti->error = "RAID device lookup failure";
 908			return r;
 909		}
 910
 911		if (rs->dev[i].meta_dev) {
 912			metadata_available = 1;
 913			rs->dev[i].rdev.meta_bdev = rs->dev[i].meta_dev->bdev;
 914		}
 915		rs->dev[i].rdev.bdev = rs->dev[i].data_dev->bdev;
 916		list_add_tail(&rs->dev[i].rdev.same_set, &rs->md.disks);
 917		if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
 918			rebuild++;
 919	}
 920
 921	if (rs->journal_dev.dev)
 922		list_add_tail(&rs->journal_dev.rdev.same_set, &rs->md.disks);
 923
 924	if (metadata_available) {
 925		rs->md.external = 0;
 926		rs->md.persistent = 1;
 927		rs->md.major_version = 2;
 928	} else if (rebuild && !rs->md.recovery_cp) {
 929		/*
 930		 * Without metadata, we will not be able to tell if the array
 931		 * is in-sync or not - we must assume it is not.  Therefore,
 932		 * it is impossible to rebuild a drive.
 933		 *
 934		 * Even if there is metadata, the on-disk information may
 935		 * indicate that the array is not in-sync and it will then
 936		 * fail at that time.
 937		 *
 938		 * User could specify 'nosync' option if desperate.
 939		 */
 940		rs->ti->error = "Unable to rebuild drive while array is not in-sync";
 941		return -EINVAL;
 942	}
 943
 944	return 0;
 945}
 946
 947/*
 948 * validate_region_size
 949 * @rs
 950 * @region_size:  region size in sectors.  If 0, pick a size (4MiB default).
 951 *
 952 * Set rs->md.bitmap_info.chunksize (which really refers to 'region size').
 953 * Ensure that (ti->len/region_size < 2^21) - required by MD bitmap.
 954 *
 955 * Returns: 0 on success, -EINVAL on failure.
 956 */
 957static int validate_region_size(struct raid_set *rs, unsigned long region_size)
 958{
 959	unsigned long min_region_size = rs->ti->len / (1 << 21);
 960
 961	if (rs_is_raid0(rs))
 962		return 0;
 963
 964	if (!region_size) {
 965		/*
 966		 * Choose a reasonable default.	 All figures in sectors.
 967		 */
 968		if (min_region_size > (1 << 13)) {
 969			/* If not a power of 2, make it the next power of 2 */
 970			region_size = roundup_pow_of_two(min_region_size);
 971			DMINFO("Choosing default region size of %lu sectors",
 972			       region_size);
 973		} else {
 974			DMINFO("Choosing default region size of 4MiB");
 975			region_size = 1 << 13; /* sectors */
 976		}
 977	} else {
 978		/*
 979		 * Validate user-supplied value.
 980		 */
 981		if (region_size > rs->ti->len) {
 982			rs->ti->error = "Supplied region size is too large";
 983			return -EINVAL;
 984		}
 985
 986		if (region_size < min_region_size) {
 987			DMERR("Supplied region_size (%lu sectors) below minimum (%lu)",
 988			      region_size, min_region_size);
 989			rs->ti->error = "Supplied region size is too small";
 990			return -EINVAL;
 991		}
 992
 993		if (!is_power_of_2(region_size)) {
 994			rs->ti->error = "Region size is not a power of 2";
 995			return -EINVAL;
 996		}
 997
 998		if (region_size < rs->md.chunk_sectors) {
 999			rs->ti->error = "Region size is smaller than the chunk size";
1000			return -EINVAL;
1001		}
1002	}
1003
1004	/*
1005	 * Convert sectors to bytes.
1006	 */
1007	rs->md.bitmap_info.chunksize = to_bytes(region_size);
1008
1009	return 0;
1010}
1011
1012/*
1013 * validate_raid_redundancy
1014 * @rs
1015 *
1016 * Determine if there are enough devices in the array that haven't
1017 * failed (or are being rebuilt) to form a usable array.
1018 *
1019 * Returns: 0 on success, -EINVAL on failure.
1020 */
1021static int validate_raid_redundancy(struct raid_set *rs)
1022{
1023	unsigned int i, rebuild_cnt = 0;
1024	unsigned int rebuilds_per_group = 0, copies;
1025	unsigned int group_size, last_group_start;
1026
1027	for (i = 0; i < rs->md.raid_disks; i++)
1028		if (!test_bit(In_sync, &rs->dev[i].rdev.flags) ||
1029		    !rs->dev[i].rdev.sb_page)
 
1030			rebuild_cnt++;
1031
1032	switch (rs->md.level) {
1033	case 0:
1034		break;
1035	case 1:
1036		if (rebuild_cnt >= rs->md.raid_disks)
1037			goto too_many;
1038		break;
1039	case 4:
1040	case 5:
1041	case 6:
1042		if (rebuild_cnt > rs->raid_type->parity_devs)
1043			goto too_many;
1044		break;
1045	case 10:
1046		copies = raid10_md_layout_to_copies(rs->md.new_layout);
1047		if (copies < 2) {
1048			DMERR("Bogus raid10 data copies < 2!");
1049			return -EINVAL;
1050		}
1051
1052		if (rebuild_cnt < copies)
1053			break;
1054
1055		/*
1056		 * It is possible to have a higher rebuild count for RAID10,
1057		 * as long as the failed devices occur in different mirror
1058		 * groups (i.e. different stripes).
1059		 *
1060		 * When checking "near" format, make sure no adjacent devices
1061		 * have failed beyond what can be handled.  In addition to the
1062		 * simple case where the number of devices is a multiple of the
1063		 * number of copies, we must also handle cases where the number
1064		 * of devices is not a multiple of the number of copies.
1065		 * E.g.	   dev1 dev2 dev3 dev4 dev5
1066		 *	    A	 A    B	   B	C
1067		 *	    C	 D    D	   E	E
1068		 */
 
1069		if (__is_raid10_near(rs->md.new_layout)) {
1070			for (i = 0; i < rs->md.raid_disks; i++) {
1071				if (!(i % copies))
1072					rebuilds_per_group = 0;
1073				if ((!rs->dev[i].rdev.sb_page ||
1074				    !test_bit(In_sync, &rs->dev[i].rdev.flags)) &&
1075				    (++rebuilds_per_group >= copies))
1076					goto too_many;
1077			}
1078			break;
1079		}
1080
1081		/*
1082		 * When checking "far" and "offset" formats, we need to ensure
1083		 * that the device that holds its copy is not also dead or
1084		 * being rebuilt.  (Note that "far" and "offset" formats only
1085		 * support two copies right now.  These formats also only ever
1086		 * use the 'use_far_sets' variant.)
1087		 *
1088		 * This check is somewhat complicated by the need to account
1089		 * for arrays that are not a multiple of (far) copies.	This
1090		 * results in the need to treat the last (potentially larger)
1091		 * set differently.
1092		 */
1093		group_size = (rs->md.raid_disks / copies);
1094		last_group_start = (rs->md.raid_disks / group_size) - 1;
1095		last_group_start *= group_size;
1096		for (i = 0; i < rs->md.raid_disks; i++) {
1097			if (!(i % copies) && !(i > last_group_start))
1098				rebuilds_per_group = 0;
1099			if ((!rs->dev[i].rdev.sb_page ||
1100			     !test_bit(In_sync, &rs->dev[i].rdev.flags)) &&
1101			    (++rebuilds_per_group >= copies))
1102					goto too_many;
1103		}
1104		break;
1105	default:
1106		if (rebuild_cnt)
1107			return -EINVAL;
1108	}
1109
1110	return 0;
1111
1112too_many:
1113	return -EINVAL;
1114}
1115
1116/*
1117 * Possible arguments are...
1118 *	<chunk_size> [optional_args]
1119 *
1120 * Argument definitions
1121 *    <chunk_size>			The number of sectors per disk that
1122 *					will form the "stripe"
1123 *    [[no]sync]			Force or prevent recovery of the
1124 *					entire array
1125 *    [rebuild <idx>]			Rebuild the drive indicated by the index
1126 *    [daemon_sleep <ms>]		Time between bitmap daemon work to
1127 *					clear bits
1128 *    [min_recovery_rate <kB/sec/disk>]	Throttle RAID initialization
1129 *    [max_recovery_rate <kB/sec/disk>]	Throttle RAID initialization
1130 *    [write_mostly <idx>]		Indicate a write mostly drive via index
1131 *    [max_write_behind <sectors>]	See '-write-behind=' (man mdadm)
1132 *    [stripe_cache <sectors>]		Stripe cache size for higher RAIDs
1133 *    [region_size <sectors>]		Defines granularity of bitmap
1134 *    [journal_dev <dev>]		raid4/5/6 journaling deviice
1135 *    					(i.e. write hole closing log)
1136 *
1137 * RAID10-only options:
1138 *    [raid10_copies <# copies>]	Number of copies.  (Default: 2)
1139 *    [raid10_format <near|far|offset>] Layout algorithm.  (Default: near)
1140 */
1141static int parse_raid_params(struct raid_set *rs, struct dm_arg_set *as,
1142			     unsigned int num_raid_params)
1143{
1144	int value, raid10_format = ALGORITHM_RAID10_DEFAULT;
1145	unsigned int raid10_copies = 2;
1146	unsigned int i, write_mostly = 0;
1147	unsigned int region_size = 0;
1148	sector_t max_io_len;
1149	const char *arg, *key;
1150	struct raid_dev *rd;
1151	struct raid_type *rt = rs->raid_type;
1152
1153	arg = dm_shift_arg(as);
1154	num_raid_params--; /* Account for chunk_size argument */
1155
1156	if (kstrtoint(arg, 10, &value) < 0) {
1157		rs->ti->error = "Bad numerical argument given for chunk_size";
1158		return -EINVAL;
1159	}
1160
1161	/*
1162	 * First, parse the in-order required arguments
1163	 * "chunk_size" is the only argument of this type.
1164	 */
1165	if (rt_is_raid1(rt)) {
1166		if (value)
1167			DMERR("Ignoring chunk size parameter for RAID 1");
1168		value = 0;
1169	} else if (!is_power_of_2(value)) {
1170		rs->ti->error = "Chunk size must be a power of 2";
1171		return -EINVAL;
1172	} else if (value < 8) {
1173		rs->ti->error = "Chunk size value is too small";
1174		return -EINVAL;
1175	}
1176
1177	rs->md.new_chunk_sectors = rs->md.chunk_sectors = value;
1178
1179	/*
1180	 * We set each individual device as In_sync with a completed
1181	 * 'recovery_offset'.  If there has been a device failure or
1182	 * replacement then one of the following cases applies:
1183	 *
1184	 *   1) User specifies 'rebuild'.
1185	 *	- Device is reset when param is read.
1186	 *   2) A new device is supplied.
1187	 *	- No matching superblock found, resets device.
1188	 *   3) Device failure was transient and returns on reload.
1189	 *	- Failure noticed, resets device for bitmap replay.
1190	 *   4) Device hadn't completed recovery after previous failure.
1191	 *	- Superblock is read and overrides recovery_offset.
1192	 *
1193	 * What is found in the superblocks of the devices is always
1194	 * authoritative, unless 'rebuild' or '[no]sync' was specified.
1195	 */
1196	for (i = 0; i < rs->raid_disks; i++) {
1197		set_bit(In_sync, &rs->dev[i].rdev.flags);
1198		rs->dev[i].rdev.recovery_offset = MaxSector;
1199	}
1200
1201	/*
1202	 * Second, parse the unordered optional arguments
1203	 */
1204	for (i = 0; i < num_raid_params; i++) {
1205		key = dm_shift_arg(as);
1206		if (!key) {
1207			rs->ti->error = "Not enough raid parameters given";
1208			return -EINVAL;
1209		}
1210
1211		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_NOSYNC))) {
1212			if (test_and_set_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
1213				rs->ti->error = "Only one 'nosync' argument allowed";
1214				return -EINVAL;
1215			}
1216			continue;
1217		}
1218		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_SYNC))) {
1219			if (test_and_set_bit(__CTR_FLAG_SYNC, &rs->ctr_flags)) {
1220				rs->ti->error = "Only one 'sync' argument allowed";
1221				return -EINVAL;
1222			}
1223			continue;
1224		}
1225		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_USE_NEAR_SETS))) {
1226			if (test_and_set_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags)) {
1227				rs->ti->error = "Only one 'raid10_use_new_sets' argument allowed";
1228				return -EINVAL;
1229			}
1230			continue;
1231		}
1232
1233		arg = dm_shift_arg(as);
1234		i++; /* Account for the argument pairs */
1235		if (!arg) {
1236			rs->ti->error = "Wrong number of raid parameters given";
1237			return -EINVAL;
1238		}
1239
1240		/*
1241		 * Parameters that take a string value are checked here.
1242		 */
1243		/* "raid10_format {near|offset|far} */
1244		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_FORMAT))) {
1245			if (test_and_set_bit(__CTR_FLAG_RAID10_FORMAT, &rs->ctr_flags)) {
1246				rs->ti->error = "Only one 'raid10_format' argument pair allowed";
1247				return -EINVAL;
1248			}
1249			if (!rt_is_raid10(rt)) {
1250				rs->ti->error = "'raid10_format' is an invalid parameter for this RAID type";
1251				return -EINVAL;
1252			}
1253			raid10_format = raid10_name_to_format(arg);
1254			if (raid10_format < 0) {
1255				rs->ti->error = "Invalid 'raid10_format' value given";
1256				return raid10_format;
1257			}
1258			continue;
1259		}
1260
1261		/* "journal_dev <dev>" */
1262		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_DEV))) {
1263			int r;
1264			struct md_rdev *jdev;
1265
1266			if (test_and_set_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
1267				rs->ti->error = "Only one raid4/5/6 set journaling device allowed";
1268				return -EINVAL;
1269			}
1270			if (!rt_is_raid456(rt)) {
1271				rs->ti->error = "'journal_dev' is an invalid parameter for this RAID type";
1272				return -EINVAL;
1273			}
1274			r = dm_get_device(rs->ti, arg, dm_table_get_mode(rs->ti->table),
1275					  &rs->journal_dev.dev);
1276			if (r) {
1277				rs->ti->error = "raid4/5/6 journal device lookup failure";
1278				return r;
1279			}
1280			jdev = &rs->journal_dev.rdev;
1281			md_rdev_init(jdev);
1282			jdev->mddev = &rs->md;
1283			jdev->bdev = rs->journal_dev.dev->bdev;
1284			jdev->sectors = to_sector(i_size_read(jdev->bdev->bd_inode));
1285			if (jdev->sectors < MIN_RAID456_JOURNAL_SPACE) {
1286				rs->ti->error = "No space for raid4/5/6 journal";
1287				return -ENOSPC;
1288			}
1289			rs->journal_dev.mode = R5C_JOURNAL_MODE_WRITE_THROUGH;
1290			set_bit(Journal, &jdev->flags);
1291			continue;
1292		}
1293
1294		/* "journal_mode <mode>" ("journal_dev" mandatory!) */
1295		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_MODE))) {
1296			int r;
1297
1298			if (!test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
1299				rs->ti->error = "raid4/5/6 'journal_mode' is invalid without 'journal_dev'";
1300				return -EINVAL;
1301			}
1302			if (test_and_set_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags)) {
1303				rs->ti->error = "Only one raid4/5/6 'journal_mode' argument allowed";
1304				return -EINVAL;
1305			}
1306			r = dm_raid_journal_mode_to_md(arg);
1307			if (r < 0) {
1308				rs->ti->error = "Invalid 'journal_mode' argument";
1309				return r;
1310			}
1311			rs->journal_dev.mode = r;
1312			continue;
1313		}
1314
1315		/*
1316		 * Parameters with number values from here on.
1317		 */
1318		if (kstrtoint(arg, 10, &value) < 0) {
1319			rs->ti->error = "Bad numerical argument given in raid params";
1320			return -EINVAL;
1321		}
1322
1323		if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_REBUILD))) {
1324			/*
1325			 * "rebuild" is being passed in by userspace to provide
1326			 * indexes of replaced devices and to set up additional
1327			 * devices on raid level takeover.
1328			 */
1329			if (!__within_range(value, 0, rs->raid_disks - 1)) {
1330				rs->ti->error = "Invalid rebuild index given";
1331				return -EINVAL;
1332			}
1333
1334			if (test_and_set_bit(value, (void *) rs->rebuild_disks)) {
1335				rs->ti->error = "rebuild for this index already given";
1336				return -EINVAL;
1337			}
1338
1339			rd = rs->dev + value;
1340			clear_bit(In_sync, &rd->rdev.flags);
1341			clear_bit(Faulty, &rd->rdev.flags);
1342			rd->rdev.recovery_offset = 0;
1343			set_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags);
1344		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_WRITE_MOSTLY))) {
1345			if (!rt_is_raid1(rt)) {
1346				rs->ti->error = "write_mostly option is only valid for RAID1";
1347				return -EINVAL;
1348			}
1349
1350			if (!__within_range(value, 0, rs->md.raid_disks - 1)) {
1351				rs->ti->error = "Invalid write_mostly index given";
1352				return -EINVAL;
1353			}
1354
1355			write_mostly++;
1356			set_bit(WriteMostly, &rs->dev[value].rdev.flags);
1357			set_bit(__CTR_FLAG_WRITE_MOSTLY, &rs->ctr_flags);
1358		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_MAX_WRITE_BEHIND))) {
1359			if (!rt_is_raid1(rt)) {
1360				rs->ti->error = "max_write_behind option is only valid for RAID1";
1361				return -EINVAL;
1362			}
1363
1364			if (test_and_set_bit(__CTR_FLAG_MAX_WRITE_BEHIND, &rs->ctr_flags)) {
1365				rs->ti->error = "Only one max_write_behind argument pair allowed";
1366				return -EINVAL;
1367			}
1368
1369			/*
1370			 * In device-mapper, we specify things in sectors, but
1371			 * MD records this value in kB
1372			 */
1373			if (value < 0 || value / 2 > COUNTER_MAX) {
1374				rs->ti->error = "Max write-behind limit out of range";
1375				return -EINVAL;
1376			}
1377
1378			rs->md.bitmap_info.max_write_behind = value / 2;
1379		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_DAEMON_SLEEP))) {
1380			if (test_and_set_bit(__CTR_FLAG_DAEMON_SLEEP, &rs->ctr_flags)) {
1381				rs->ti->error = "Only one daemon_sleep argument pair allowed";
1382				return -EINVAL;
1383			}
1384			if (value < 0) {
1385				rs->ti->error = "daemon sleep period out of range";
1386				return -EINVAL;
1387			}
1388			rs->md.bitmap_info.daemon_sleep = value;
1389		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_DATA_OFFSET))) {
1390			/* Userspace passes new data_offset after having extended the the data image LV */
1391			if (test_and_set_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags)) {
1392				rs->ti->error = "Only one data_offset argument pair allowed";
1393				return -EINVAL;
1394			}
1395			/* Ensure sensible data offset */
1396			if (value < 0 ||
1397			    (value && (value < MIN_FREE_RESHAPE_SPACE || value % to_sector(PAGE_SIZE)))) {
1398				rs->ti->error = "Bogus data_offset value";
1399				return -EINVAL;
1400			}
1401			rs->data_offset = value;
1402		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_DELTA_DISKS))) {
1403			/* Define the +/-# of disks to add to/remove from the given raid set */
1404			if (test_and_set_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags)) {
1405				rs->ti->error = "Only one delta_disks argument pair allowed";
1406				return -EINVAL;
1407			}
1408			/* Ensure MAX_RAID_DEVICES and raid type minimal_devs! */
1409			if (!__within_range(abs(value), 1, MAX_RAID_DEVICES - rt->minimal_devs)) {
1410				rs->ti->error = "Too many delta_disk requested";
1411				return -EINVAL;
1412			}
1413
1414			rs->delta_disks = value;
1415		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_STRIPE_CACHE))) {
1416			if (test_and_set_bit(__CTR_FLAG_STRIPE_CACHE, &rs->ctr_flags)) {
1417				rs->ti->error = "Only one stripe_cache argument pair allowed";
1418				return -EINVAL;
1419			}
1420
1421			if (!rt_is_raid456(rt)) {
1422				rs->ti->error = "Inappropriate argument: stripe_cache";
1423				return -EINVAL;
1424			}
1425
1426			if (value < 0) {
1427				rs->ti->error = "Bogus stripe cache entries value";
1428				return -EINVAL;
1429			}
1430			rs->stripe_cache_entries = value;
1431		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_MIN_RECOVERY_RATE))) {
1432			if (test_and_set_bit(__CTR_FLAG_MIN_RECOVERY_RATE, &rs->ctr_flags)) {
1433				rs->ti->error = "Only one min_recovery_rate argument pair allowed";
1434				return -EINVAL;
1435			}
1436
1437			if (value < 0) {
1438				rs->ti->error = "min_recovery_rate out of range";
1439				return -EINVAL;
1440			}
1441			rs->md.sync_speed_min = value;
1442		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_MAX_RECOVERY_RATE))) {
1443			if (test_and_set_bit(__CTR_FLAG_MAX_RECOVERY_RATE, &rs->ctr_flags)) {
1444				rs->ti->error = "Only one max_recovery_rate argument pair allowed";
1445				return -EINVAL;
1446			}
1447
1448			if (value < 0) {
1449				rs->ti->error = "max_recovery_rate out of range";
1450				return -EINVAL;
1451			}
1452			rs->md.sync_speed_max = value;
1453		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_REGION_SIZE))) {
1454			if (test_and_set_bit(__CTR_FLAG_REGION_SIZE, &rs->ctr_flags)) {
1455				rs->ti->error = "Only one region_size argument pair allowed";
1456				return -EINVAL;
1457			}
1458
1459			region_size = value;
1460			rs->requested_bitmap_chunk_sectors = value;
1461		} else if (!strcasecmp(key, dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_COPIES))) {
1462			if (test_and_set_bit(__CTR_FLAG_RAID10_COPIES, &rs->ctr_flags)) {
1463				rs->ti->error = "Only one raid10_copies argument pair allowed";
1464				return -EINVAL;
1465			}
1466
1467			if (!__within_range(value, 2, rs->md.raid_disks)) {
1468				rs->ti->error = "Bad value for 'raid10_copies'";
1469				return -EINVAL;
1470			}
1471
1472			raid10_copies = value;
1473		} else {
1474			DMERR("Unable to parse RAID parameter: %s", key);
1475			rs->ti->error = "Unable to parse RAID parameter";
1476			return -EINVAL;
1477		}
1478	}
1479
1480	if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags) &&
1481	    test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
1482		rs->ti->error = "sync and nosync are mutually exclusive";
1483		return -EINVAL;
1484	}
1485
1486	if (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags) &&
1487	    (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags) ||
1488	     test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))) {
1489		rs->ti->error = "sync/nosync and rebuild are mutually exclusive";
1490		return -EINVAL;
1491	}
1492
1493	if (write_mostly >= rs->md.raid_disks) {
1494		rs->ti->error = "Can't set all raid1 devices to write_mostly";
1495		return -EINVAL;
1496	}
1497
1498	if (rs->md.sync_speed_max &&
1499	    rs->md.sync_speed_min > rs->md.sync_speed_max) {
1500		rs->ti->error = "Bogus recovery rates";
1501		return -EINVAL;
1502	}
1503
1504	if (validate_region_size(rs, region_size))
1505		return -EINVAL;
1506
1507	if (rs->md.chunk_sectors)
1508		max_io_len = rs->md.chunk_sectors;
1509	else
1510		max_io_len = region_size;
1511
1512	if (dm_set_target_max_io_len(rs->ti, max_io_len))
1513		return -EINVAL;
1514
1515	if (rt_is_raid10(rt)) {
1516		if (raid10_copies > rs->md.raid_disks) {
1517			rs->ti->error = "Not enough devices to satisfy specification";
1518			return -EINVAL;
1519		}
1520
1521		rs->md.new_layout = raid10_format_to_md_layout(rs, raid10_format, raid10_copies);
1522		if (rs->md.new_layout < 0) {
1523			rs->ti->error = "Error getting raid10 format";
1524			return rs->md.new_layout;
1525		}
1526
1527		rt = get_raid_type_by_ll(10, rs->md.new_layout);
1528		if (!rt) {
1529			rs->ti->error = "Failed to recognize new raid10 layout";
1530			return -EINVAL;
1531		}
1532
1533		if ((rt->algorithm == ALGORITHM_RAID10_DEFAULT ||
1534		     rt->algorithm == ALGORITHM_RAID10_NEAR) &&
1535		    test_bit(__CTR_FLAG_RAID10_USE_NEAR_SETS, &rs->ctr_flags)) {
1536			rs->ti->error = "RAID10 format 'near' and 'raid10_use_near_sets' are incompatible";
1537			return -EINVAL;
1538		}
1539	}
1540
1541	rs->raid10_copies = raid10_copies;
1542
1543	/* Assume there are no metadata devices until the drives are parsed */
1544	rs->md.persistent = 0;
1545	rs->md.external = 1;
1546
1547	/* Check, if any invalid ctr arguments have been passed in for the raid level */
1548	return rs_check_for_valid_flags(rs);
1549}
1550
1551/* Set raid4/5/6 cache size */
1552static int rs_set_raid456_stripe_cache(struct raid_set *rs)
1553{
1554	int r;
1555	struct r5conf *conf;
1556	struct mddev *mddev = &rs->md;
1557	uint32_t min_stripes = max(mddev->chunk_sectors, mddev->new_chunk_sectors) / 2;
1558	uint32_t nr_stripes = rs->stripe_cache_entries;
1559
1560	if (!rt_is_raid456(rs->raid_type)) {
1561		rs->ti->error = "Inappropriate raid level; cannot change stripe_cache size";
1562		return -EINVAL;
1563	}
1564
1565	if (nr_stripes < min_stripes) {
1566		DMINFO("Adjusting requested %u stripe cache entries to %u to suit stripe size",
1567		       nr_stripes, min_stripes);
1568		nr_stripes = min_stripes;
1569	}
1570
1571	conf = mddev->private;
1572	if (!conf) {
1573		rs->ti->error = "Cannot change stripe_cache size on inactive RAID set";
1574		return -EINVAL;
1575	}
1576
1577	/* Try setting number of stripes in raid456 stripe cache */
1578	if (conf->min_nr_stripes != nr_stripes) {
1579		r = raid5_set_cache_size(mddev, nr_stripes);
1580		if (r) {
1581			rs->ti->error = "Failed to set raid4/5/6 stripe cache size";
1582			return r;
1583		}
1584
1585		DMINFO("%u stripe cache entries", nr_stripes);
1586	}
1587
1588	return 0;
1589}
1590
1591/* Return # of data stripes as kept in mddev as of @rs (i.e. as of superblock) */
1592static unsigned int mddev_data_stripes(struct raid_set *rs)
1593{
1594	return rs->md.raid_disks - rs->raid_type->parity_devs;
1595}
1596
1597/* Return # of data stripes of @rs (i.e. as of ctr) */
1598static unsigned int rs_data_stripes(struct raid_set *rs)
1599{
1600	return rs->raid_disks - rs->raid_type->parity_devs;
1601}
1602
1603/*
1604 * Retrieve rdev->sectors from any valid raid device of @rs
1605 * to allow userpace to pass in arbitray "- -" device tupples.
1606 */
1607static sector_t __rdev_sectors(struct raid_set *rs)
1608{
1609	int i;
1610
1611	for (i = 0; i < rs->md.raid_disks; i++) {
1612		struct md_rdev *rdev = &rs->dev[i].rdev;
1613
1614		if (!test_bit(Journal, &rdev->flags) &&
1615		    rdev->bdev && rdev->sectors)
1616			return rdev->sectors;
1617	}
1618
1619	return 0;
1620}
1621
1622/* Check that calculated dev_sectors fits all component devices. */
1623static int _check_data_dev_sectors(struct raid_set *rs)
1624{
1625	sector_t ds = ~0;
1626	struct md_rdev *rdev;
1627
1628	rdev_for_each(rdev, &rs->md)
1629		if (!test_bit(Journal, &rdev->flags) && rdev->bdev) {
1630			ds = min(ds, to_sector(i_size_read(rdev->bdev->bd_inode)));
1631			if (ds < rs->md.dev_sectors) {
1632				rs->ti->error = "Component device(s) too small";
1633				return -EINVAL;
1634			}
1635		}
1636
1637	return 0;
1638}
1639
1640/* Calculate the sectors per device and per array used for @rs */
1641static int rs_set_dev_and_array_sectors(struct raid_set *rs, bool use_mddev)
1642{
1643	int delta_disks;
1644	unsigned int data_stripes;
 
1645	struct mddev *mddev = &rs->md;
1646	struct md_rdev *rdev;
1647	sector_t array_sectors = rs->ti->len, dev_sectors = rs->ti->len;
1648
1649	if (use_mddev) {
1650		delta_disks = mddev->delta_disks;
1651		data_stripes = mddev_data_stripes(rs);
1652	} else {
1653		delta_disks = rs->delta_disks;
1654		data_stripes = rs_data_stripes(rs);
1655	}
1656
1657	/* Special raid1 case w/o delta_disks support (yet) */
1658	if (rt_is_raid1(rs->raid_type))
1659		;
1660	else if (rt_is_raid10(rs->raid_type)) {
1661		if (rs->raid10_copies < 2 ||
1662		    delta_disks < 0) {
1663			rs->ti->error = "Bogus raid10 data copies or delta disks";
1664			return -EINVAL;
1665		}
1666
1667		dev_sectors *= rs->raid10_copies;
1668		if (sector_div(dev_sectors, data_stripes))
1669			goto bad;
1670
1671		array_sectors = (data_stripes + delta_disks) * dev_sectors;
1672		if (sector_div(array_sectors, rs->raid10_copies))
1673			goto bad;
1674
1675	} else if (sector_div(dev_sectors, data_stripes))
1676		goto bad;
1677
1678	else
1679		/* Striped layouts */
1680		array_sectors = (data_stripes + delta_disks) * dev_sectors;
1681
1682	rdev_for_each(rdev, mddev)
1683		if (!test_bit(Journal, &rdev->flags))
1684			rdev->sectors = dev_sectors;
1685
1686	mddev->array_sectors = array_sectors;
1687	mddev->dev_sectors = dev_sectors;
 
1688
1689	return _check_data_dev_sectors(rs);
1690bad:
1691	rs->ti->error = "Target length not divisible by number of data devices";
1692	return -EINVAL;
1693}
1694
1695/* Setup recovery on @rs */
1696static void __rs_setup_recovery(struct raid_set *rs, sector_t dev_sectors)
1697{
1698	/* raid0 does not recover */
1699	if (rs_is_raid0(rs))
1700		rs->md.recovery_cp = MaxSector;
1701	/*
1702	 * A raid6 set has to be recovered either
1703	 * completely or for the grown part to
1704	 * ensure proper parity and Q-Syndrome
1705	 */
1706	else if (rs_is_raid6(rs))
1707		rs->md.recovery_cp = dev_sectors;
1708	/*
1709	 * Other raid set types may skip recovery
1710	 * depending on the 'nosync' flag.
1711	 */
1712	else
1713		rs->md.recovery_cp = test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)
1714				     ? MaxSector : dev_sectors;
1715}
1716
1717/* Setup recovery on @rs based on raid type, device size and 'nosync' flag */
1718static void rs_setup_recovery(struct raid_set *rs, sector_t dev_sectors)
1719{
1720	if (!dev_sectors)
1721		/* New raid set or 'sync' flag provided */
1722		__rs_setup_recovery(rs, 0);
1723	else if (dev_sectors == MaxSector)
1724		/* Prevent recovery */
1725		__rs_setup_recovery(rs, MaxSector);
1726	else if (__rdev_sectors(rs) < dev_sectors)
1727		/* Grown raid set */
1728		__rs_setup_recovery(rs, __rdev_sectors(rs));
1729	else
1730		__rs_setup_recovery(rs, MaxSector);
1731}
1732
1733static void do_table_event(struct work_struct *ws)
1734{
1735	struct raid_set *rs = container_of(ws, struct raid_set, md.event_work);
1736
1737	smp_rmb(); /* Make sure we access most actual mddev properties */
1738	if (!rs_is_reshaping(rs)) {
1739		if (rs_is_raid10(rs))
1740			rs_set_rdev_sectors(rs);
1741		rs_set_capacity(rs);
1742	}
1743	dm_table_event(rs->ti->table);
1744}
1745
1746static int raid_is_congested(struct dm_target_callbacks *cb, int bits)
1747{
1748	struct raid_set *rs = container_of(cb, struct raid_set, callbacks);
1749
1750	return mddev_congested(&rs->md, bits);
1751}
1752
1753/*
1754 * Make sure a valid takover (level switch) is being requested on @rs
1755 *
1756 * Conversions of raid sets from one MD personality to another
1757 * have to conform to restrictions which are enforced here.
1758 */
1759static int rs_check_takeover(struct raid_set *rs)
1760{
1761	struct mddev *mddev = &rs->md;
1762	unsigned int near_copies;
1763
1764	if (rs->md.degraded) {
1765		rs->ti->error = "Can't takeover degraded raid set";
1766		return -EPERM;
1767	}
1768
1769	if (rs_is_reshaping(rs)) {
1770		rs->ti->error = "Can't takeover reshaping raid set";
1771		return -EPERM;
1772	}
1773
1774	switch (mddev->level) {
1775	case 0:
1776		/* raid0 -> raid1/5 with one disk */
1777		if ((mddev->new_level == 1 || mddev->new_level == 5) &&
1778		    mddev->raid_disks == 1)
1779			return 0;
1780
1781		/* raid0 -> raid10 */
1782		if (mddev->new_level == 10 &&
1783		    !(rs->raid_disks % mddev->raid_disks))
1784			return 0;
1785
1786		/* raid0 with multiple disks -> raid4/5/6 */
1787		if (__within_range(mddev->new_level, 4, 6) &&
1788		    mddev->new_layout == ALGORITHM_PARITY_N &&
1789		    mddev->raid_disks > 1)
1790			return 0;
1791
1792		break;
1793
1794	case 10:
1795		/* Can't takeover raid10_offset! */
1796		if (__is_raid10_offset(mddev->layout))
1797			break;
1798
1799		near_copies = __raid10_near_copies(mddev->layout);
1800
1801		/* raid10* -> raid0 */
1802		if (mddev->new_level == 0) {
1803			/* Can takeover raid10_near with raid disks divisable by data copies! */
1804			if (near_copies > 1 &&
1805			    !(mddev->raid_disks % near_copies)) {
1806				mddev->raid_disks /= near_copies;
1807				mddev->delta_disks = mddev->raid_disks;
1808				return 0;
1809			}
1810
1811			/* Can takeover raid10_far */
1812			if (near_copies == 1 &&
1813			    __raid10_far_copies(mddev->layout) > 1)
1814				return 0;
1815
1816			break;
1817		}
1818
1819		/* raid10_{near,far} -> raid1 */
1820		if (mddev->new_level == 1 &&
1821		    max(near_copies, __raid10_far_copies(mddev->layout)) == mddev->raid_disks)
1822			return 0;
1823
1824		/* raid10_{near,far} with 2 disks -> raid4/5 */
1825		if (__within_range(mddev->new_level, 4, 5) &&
1826		    mddev->raid_disks == 2)
1827			return 0;
1828		break;
1829
1830	case 1:
1831		/* raid1 with 2 disks -> raid4/5 */
1832		if (__within_range(mddev->new_level, 4, 5) &&
1833		    mddev->raid_disks == 2) {
1834			mddev->degraded = 1;
1835			return 0;
1836		}
1837
1838		/* raid1 -> raid0 */
1839		if (mddev->new_level == 0 &&
1840		    mddev->raid_disks == 1)
1841			return 0;
1842
1843		/* raid1 -> raid10 */
1844		if (mddev->new_level == 10)
1845			return 0;
1846		break;
1847
1848	case 4:
1849		/* raid4 -> raid0 */
1850		if (mddev->new_level == 0)
1851			return 0;
1852
1853		/* raid4 -> raid1/5 with 2 disks */
1854		if ((mddev->new_level == 1 || mddev->new_level == 5) &&
1855		    mddev->raid_disks == 2)
1856			return 0;
1857
1858		/* raid4 -> raid5/6 with parity N */
1859		if (__within_range(mddev->new_level, 5, 6) &&
1860		    mddev->layout == ALGORITHM_PARITY_N)
1861			return 0;
1862		break;
1863
1864	case 5:
1865		/* raid5 with parity N -> raid0 */
1866		if (mddev->new_level == 0 &&
1867		    mddev->layout == ALGORITHM_PARITY_N)
1868			return 0;
1869
1870		/* raid5 with parity N -> raid4 */
1871		if (mddev->new_level == 4 &&
1872		    mddev->layout == ALGORITHM_PARITY_N)
1873			return 0;
1874
1875		/* raid5 with 2 disks -> raid1/4/10 */
1876		if ((mddev->new_level == 1 || mddev->new_level == 4 || mddev->new_level == 10) &&
1877		    mddev->raid_disks == 2)
1878			return 0;
1879
1880		/* raid5_* ->  raid6_*_6 with Q-Syndrome N (e.g. raid5_ra -> raid6_ra_6 */
1881		if (mddev->new_level == 6 &&
1882		    ((mddev->layout == ALGORITHM_PARITY_N && mddev->new_layout == ALGORITHM_PARITY_N) ||
1883		      __within_range(mddev->new_layout, ALGORITHM_LEFT_ASYMMETRIC_6, ALGORITHM_RIGHT_SYMMETRIC_6)))
1884			return 0;
1885		break;
1886
1887	case 6:
1888		/* raid6 with parity N -> raid0 */
1889		if (mddev->new_level == 0 &&
1890		    mddev->layout == ALGORITHM_PARITY_N)
1891			return 0;
1892
1893		/* raid6 with parity N -> raid4 */
1894		if (mddev->new_level == 4 &&
1895		    mddev->layout == ALGORITHM_PARITY_N)
1896			return 0;
1897
1898		/* raid6_*_n with Q-Syndrome N -> raid5_* */
1899		if (mddev->new_level == 5 &&
1900		    ((mddev->layout == ALGORITHM_PARITY_N && mddev->new_layout == ALGORITHM_PARITY_N) ||
1901		     __within_range(mddev->new_layout, ALGORITHM_LEFT_ASYMMETRIC, ALGORITHM_RIGHT_SYMMETRIC)))
1902			return 0;
 
1903
1904	default:
1905		break;
1906	}
1907
1908	rs->ti->error = "takeover not possible";
1909	return -EINVAL;
1910}
1911
1912/* True if @rs requested to be taken over */
1913static bool rs_takeover_requested(struct raid_set *rs)
1914{
1915	return rs->md.new_level != rs->md.level;
1916}
1917
 
 
 
 
 
 
 
 
1918/* True if @rs is requested to reshape by ctr */
1919static bool rs_reshape_requested(struct raid_set *rs)
1920{
1921	bool change;
1922	struct mddev *mddev = &rs->md;
1923
1924	if (rs_takeover_requested(rs))
1925		return false;
1926
1927	if (rs_is_raid0(rs))
1928		return false;
1929
1930	change = mddev->new_layout != mddev->layout ||
1931		 mddev->new_chunk_sectors != mddev->chunk_sectors ||
1932		 rs->delta_disks;
1933
1934	/* Historical case to support raid1 reshape without delta disks */
1935	if (rs_is_raid1(rs)) {
1936		if (rs->delta_disks)
1937			return !!rs->delta_disks;
1938
1939		return !change &&
1940		       mddev->raid_disks != rs->raid_disks;
1941	}
1942
1943	if (rs_is_raid10(rs))
1944		return change &&
1945		       !__is_raid10_far(mddev->new_layout) &&
1946		       rs->delta_disks >= 0;
1947
1948	return change;
1949}
1950
1951/*  Features */
1952#define	FEATURE_FLAG_SUPPORTS_V190	0x1 /* Supports extended superblock */
1953
1954/* State flags for sb->flags */
1955#define	SB_FLAG_RESHAPE_ACTIVE		0x1
1956#define	SB_FLAG_RESHAPE_BACKWARDS	0x2
1957
1958/*
1959 * This structure is never routinely used by userspace, unlike md superblocks.
1960 * Devices with this superblock should only ever be accessed via device-mapper.
1961 */
1962#define DM_RAID_MAGIC 0x64526D44
1963struct dm_raid_superblock {
1964	__le32 magic;		/* "DmRd" */
1965	__le32 compat_features;	/* Used to indicate compatible features (like 1.9.0 ondisk metadata extension) */
1966
1967	__le32 num_devices;	/* Number of devices in this raid set. (Max 64) */
1968	__le32 array_position;	/* The position of this drive in the raid set */
1969
1970	__le64 events;		/* Incremented by md when superblock updated */
1971	__le64 failed_devices;	/* Pre 1.9.0 part of bit field of devices to */
1972				/* indicate failures (see extension below) */
1973
1974	/*
1975	 * This offset tracks the progress of the repair or replacement of
1976	 * an individual drive.
1977	 */
1978	__le64 disk_recovery_offset;
1979
1980	/*
1981	 * This offset tracks the progress of the initial raid set
1982	 * synchronisation/parity calculation.
1983	 */
1984	__le64 array_resync_offset;
1985
1986	/*
1987	 * raid characteristics
1988	 */
1989	__le32 level;
1990	__le32 layout;
1991	__le32 stripe_sectors;
1992
1993	/********************************************************************
1994	 * BELOW FOLLOW V1.9.0 EXTENSIONS TO THE PRISTINE SUPERBLOCK FORMAT!!!
1995	 *
1996	 * FEATURE_FLAG_SUPPORTS_V190 in the compat_features member indicates that those exist
1997	 */
1998
1999	__le32 flags; /* Flags defining array states for reshaping */
2000
2001	/*
2002	 * This offset tracks the progress of a raid
2003	 * set reshape in order to be able to restart it
2004	 */
2005	__le64 reshape_position;
2006
2007	/*
2008	 * These define the properties of the array in case of an interrupted reshape
2009	 */
2010	__le32 new_level;
2011	__le32 new_layout;
2012	__le32 new_stripe_sectors;
2013	__le32 delta_disks;
2014
2015	__le64 array_sectors; /* Array size in sectors */
2016
2017	/*
2018	 * Sector offsets to data on devices (reshaping).
2019	 * Needed to support out of place reshaping, thus
2020	 * not writing over any stripes whilst converting
2021	 * them from old to new layout
2022	 */
2023	__le64 data_offset;
2024	__le64 new_data_offset;
2025
2026	__le64 sectors; /* Used device size in sectors */
2027
2028	/*
2029	 * Additonal Bit field of devices indicating failures to support
2030	 * up to 256 devices with the 1.9.0 on-disk metadata format
2031	 */
2032	__le64 extended_failed_devices[DISKS_ARRAY_ELEMS - 1];
2033
2034	__le32 incompat_features;	/* Used to indicate any incompatible features */
2035
2036	/* Always set rest up to logical block size to 0 when writing (see get_metadata_device() below). */
2037} __packed;
2038
2039/*
2040 * Check for reshape constraints on raid set @rs:
2041 *
2042 * - reshape function non-existent
2043 * - degraded set
2044 * - ongoing recovery
2045 * - ongoing reshape
2046 *
2047 * Returns 0 if none or -EPERM if given constraint
2048 * and error message reference in @errmsg
2049 */
2050static int rs_check_reshape(struct raid_set *rs)
2051{
2052	struct mddev *mddev = &rs->md;
2053
2054	if (!mddev->pers || !mddev->pers->check_reshape)
2055		rs->ti->error = "Reshape not supported";
2056	else if (mddev->degraded)
2057		rs->ti->error = "Can't reshape degraded raid set";
2058	else if (rs_is_recovering(rs))
2059		rs->ti->error = "Convert request on recovering raid set prohibited";
2060	else if (rs_is_reshaping(rs))
2061		rs->ti->error = "raid set already reshaping!";
2062	else if (!(rs_is_raid1(rs) || rs_is_raid10(rs) || rs_is_raid456(rs)))
2063		rs->ti->error = "Reshaping only supported for raid1/4/5/6/10";
2064	else
2065		return 0;
2066
2067	return -EPERM;
2068}
2069
2070static int read_disk_sb(struct md_rdev *rdev, int size, bool force_reload)
2071{
2072	BUG_ON(!rdev->sb_page);
2073
2074	if (rdev->sb_loaded && !force_reload)
2075		return 0;
2076
2077	rdev->sb_loaded = 0;
2078
2079	if (!sync_page_io(rdev, 0, size, rdev->sb_page, REQ_OP_READ, 0, true)) {
2080		DMERR("Failed to read superblock of device at position %d",
2081		      rdev->raid_disk);
2082		md_error(rdev->mddev, rdev);
2083		set_bit(Faulty, &rdev->flags);
2084		return -EIO;
2085	}
2086
2087	rdev->sb_loaded = 1;
2088
2089	return 0;
2090}
2091
2092static void sb_retrieve_failed_devices(struct dm_raid_superblock *sb, uint64_t *failed_devices)
2093{
2094	failed_devices[0] = le64_to_cpu(sb->failed_devices);
2095	memset(failed_devices + 1, 0, sizeof(sb->extended_failed_devices));
2096
2097	if (le32_to_cpu(sb->compat_features) & FEATURE_FLAG_SUPPORTS_V190) {
2098		int i = ARRAY_SIZE(sb->extended_failed_devices);
2099
2100		while (i--)
2101			failed_devices[i+1] = le64_to_cpu(sb->extended_failed_devices[i]);
2102	}
2103}
2104
2105static void sb_update_failed_devices(struct dm_raid_superblock *sb, uint64_t *failed_devices)
2106{
2107	int i = ARRAY_SIZE(sb->extended_failed_devices);
2108
2109	sb->failed_devices = cpu_to_le64(failed_devices[0]);
2110	while (i--)
2111		sb->extended_failed_devices[i] = cpu_to_le64(failed_devices[i+1]);
2112}
2113
2114/*
2115 * Synchronize the superblock members with the raid set properties
2116 *
2117 * All superblock data is little endian.
2118 */
2119static void super_sync(struct mddev *mddev, struct md_rdev *rdev)
2120{
2121	bool update_failed_devices = false;
2122	unsigned int i;
2123	uint64_t failed_devices[DISKS_ARRAY_ELEMS];
2124	struct dm_raid_superblock *sb;
2125	struct raid_set *rs = container_of(mddev, struct raid_set, md);
2126
2127	/* No metadata device, no superblock */
2128	if (!rdev->meta_bdev)
2129		return;
2130
2131	BUG_ON(!rdev->sb_page);
2132
2133	sb = page_address(rdev->sb_page);
2134
2135	sb_retrieve_failed_devices(sb, failed_devices);
2136
2137	for (i = 0; i < rs->raid_disks; i++)
2138		if (!rs->dev[i].data_dev || test_bit(Faulty, &rs->dev[i].rdev.flags)) {
2139			update_failed_devices = true;
2140			set_bit(i, (void *) failed_devices);
2141		}
2142
2143	if (update_failed_devices)
2144		sb_update_failed_devices(sb, failed_devices);
2145
2146	sb->magic = cpu_to_le32(DM_RAID_MAGIC);
2147	sb->compat_features = cpu_to_le32(FEATURE_FLAG_SUPPORTS_V190);
2148
2149	sb->num_devices = cpu_to_le32(mddev->raid_disks);
2150	sb->array_position = cpu_to_le32(rdev->raid_disk);
2151
2152	sb->events = cpu_to_le64(mddev->events);
2153
2154	sb->disk_recovery_offset = cpu_to_le64(rdev->recovery_offset);
2155	sb->array_resync_offset = cpu_to_le64(mddev->recovery_cp);
2156
2157	sb->level = cpu_to_le32(mddev->level);
2158	sb->layout = cpu_to_le32(mddev->layout);
2159	sb->stripe_sectors = cpu_to_le32(mddev->chunk_sectors);
2160
2161	/********************************************************************
2162	 * BELOW FOLLOW V1.9.0 EXTENSIONS TO THE PRISTINE SUPERBLOCK FORMAT!!!
2163	 *
2164	 * FEATURE_FLAG_SUPPORTS_V190 in the compat_features member indicates that those exist
2165	 */
2166	sb->new_level = cpu_to_le32(mddev->new_level);
2167	sb->new_layout = cpu_to_le32(mddev->new_layout);
2168	sb->new_stripe_sectors = cpu_to_le32(mddev->new_chunk_sectors);
2169
2170	sb->delta_disks = cpu_to_le32(mddev->delta_disks);
2171
2172	smp_rmb(); /* Make sure we access most recent reshape position */
2173	sb->reshape_position = cpu_to_le64(mddev->reshape_position);
2174	if (le64_to_cpu(sb->reshape_position) != MaxSector) {
2175		/* Flag ongoing reshape */
2176		sb->flags |= cpu_to_le32(SB_FLAG_RESHAPE_ACTIVE);
2177
2178		if (mddev->delta_disks < 0 || mddev->reshape_backwards)
2179			sb->flags |= cpu_to_le32(SB_FLAG_RESHAPE_BACKWARDS);
2180	} else {
2181		/* Clear reshape flags */
2182		sb->flags &= ~(cpu_to_le32(SB_FLAG_RESHAPE_ACTIVE|SB_FLAG_RESHAPE_BACKWARDS));
2183	}
2184
2185	sb->array_sectors = cpu_to_le64(mddev->array_sectors);
2186	sb->data_offset = cpu_to_le64(rdev->data_offset);
2187	sb->new_data_offset = cpu_to_le64(rdev->new_data_offset);
2188	sb->sectors = cpu_to_le64(rdev->sectors);
2189	sb->incompat_features = cpu_to_le32(0);
2190
2191	/* Zero out the rest of the payload after the size of the superblock */
2192	memset(sb + 1, 0, rdev->sb_size - sizeof(*sb));
2193}
2194
2195/*
2196 * super_load
2197 *
2198 * This function creates a superblock if one is not found on the device
2199 * and will decide which superblock to use if there's a choice.
2200 *
2201 * Return: 1 if use rdev, 0 if use refdev, -Exxx otherwise
2202 */
2203static int super_load(struct md_rdev *rdev, struct md_rdev *refdev)
2204{
2205	int r;
2206	struct dm_raid_superblock *sb;
2207	struct dm_raid_superblock *refsb;
2208	uint64_t events_sb, events_refsb;
2209
2210	r = read_disk_sb(rdev, rdev->sb_size, false);
2211	if (r)
2212		return r;
2213
2214	sb = page_address(rdev->sb_page);
2215
2216	/*
2217	 * Two cases that we want to write new superblocks and rebuild:
2218	 * 1) New device (no matching magic number)
2219	 * 2) Device specified for rebuild (!In_sync w/ offset == 0)
2220	 */
2221	if ((sb->magic != cpu_to_le32(DM_RAID_MAGIC)) ||
2222	    (!test_bit(In_sync, &rdev->flags) && !rdev->recovery_offset)) {
2223		super_sync(rdev->mddev, rdev);
2224
2225		set_bit(FirstUse, &rdev->flags);
2226		sb->compat_features = cpu_to_le32(FEATURE_FLAG_SUPPORTS_V190);
2227
2228		/* Force writing of superblocks to disk */
2229		set_bit(MD_SB_CHANGE_DEVS, &rdev->mddev->sb_flags);
2230
2231		/* Any superblock is better than none, choose that if given */
2232		return refdev ? 0 : 1;
2233	}
2234
2235	if (!refdev)
2236		return 1;
2237
2238	events_sb = le64_to_cpu(sb->events);
2239
2240	refsb = page_address(refdev->sb_page);
2241	events_refsb = le64_to_cpu(refsb->events);
2242
2243	return (events_sb > events_refsb) ? 1 : 0;
2244}
2245
2246static int super_init_validation(struct raid_set *rs, struct md_rdev *rdev)
2247{
2248	int role;
2249	unsigned int d;
2250	struct mddev *mddev = &rs->md;
2251	uint64_t events_sb;
2252	uint64_t failed_devices[DISKS_ARRAY_ELEMS];
2253	struct dm_raid_superblock *sb;
2254	uint32_t new_devs = 0, rebuild_and_new = 0, rebuilds = 0;
2255	struct md_rdev *r;
2256	struct dm_raid_superblock *sb2;
2257
2258	sb = page_address(rdev->sb_page);
2259	events_sb = le64_to_cpu(sb->events);
2260
2261	/*
2262	 * Initialise to 1 if this is a new superblock.
2263	 */
2264	mddev->events = events_sb ? : 1;
2265
2266	mddev->reshape_position = MaxSector;
2267
2268	mddev->raid_disks = le32_to_cpu(sb->num_devices);
2269	mddev->level = le32_to_cpu(sb->level);
2270	mddev->layout = le32_to_cpu(sb->layout);
2271	mddev->chunk_sectors = le32_to_cpu(sb->stripe_sectors);
2272
2273	/*
2274	 * Reshaping is supported, e.g. reshape_position is valid
2275	 * in superblock and superblock content is authoritative.
2276	 */
2277	if (le32_to_cpu(sb->compat_features) & FEATURE_FLAG_SUPPORTS_V190) {
2278		/* Superblock is authoritative wrt given raid set layout! */
2279		mddev->new_level = le32_to_cpu(sb->new_level);
2280		mddev->new_layout = le32_to_cpu(sb->new_layout);
2281		mddev->new_chunk_sectors = le32_to_cpu(sb->new_stripe_sectors);
2282		mddev->delta_disks = le32_to_cpu(sb->delta_disks);
2283		mddev->array_sectors = le64_to_cpu(sb->array_sectors);
2284
2285		/* raid was reshaping and got interrupted */
2286		if (le32_to_cpu(sb->flags) & SB_FLAG_RESHAPE_ACTIVE) {
2287			if (test_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags)) {
2288				DMERR("Reshape requested but raid set is still reshaping");
2289				return -EINVAL;
2290			}
2291
2292			if (mddev->delta_disks < 0 ||
2293			    (!mddev->delta_disks && (le32_to_cpu(sb->flags) & SB_FLAG_RESHAPE_BACKWARDS)))
2294				mddev->reshape_backwards = 1;
2295			else
2296				mddev->reshape_backwards = 0;
2297
2298			mddev->reshape_position = le64_to_cpu(sb->reshape_position);
2299			rs->raid_type = get_raid_type_by_ll(mddev->level, mddev->layout);
2300		}
2301
2302	} else {
2303		/*
2304		 * No takeover/reshaping, because we don't have the extended v1.9.0 metadata
2305		 */
2306		struct raid_type *rt_cur = get_raid_type_by_ll(mddev->level, mddev->layout);
2307		struct raid_type *rt_new = get_raid_type_by_ll(mddev->new_level, mddev->new_layout);
2308
2309		if (rs_takeover_requested(rs)) {
2310			if (rt_cur && rt_new)
2311				DMERR("Takeover raid sets from %s to %s not yet supported by metadata. (raid level change)",
2312				      rt_cur->name, rt_new->name);
2313			else
2314				DMERR("Takeover raid sets not yet supported by metadata. (raid level change)");
2315			return -EINVAL;
2316		} else if (rs_reshape_requested(rs)) {
2317			DMERR("Reshaping raid sets not yet supported by metadata. (raid layout change keeping level)");
2318			if (mddev->layout != mddev->new_layout) {
2319				if (rt_cur && rt_new)
2320					DMERR("	 current layout %s vs new layout %s",
2321					      rt_cur->name, rt_new->name);
2322				else
2323					DMERR("	 current layout 0x%X vs new layout 0x%X",
2324					      le32_to_cpu(sb->layout), mddev->new_layout);
2325			}
2326			if (mddev->chunk_sectors != mddev->new_chunk_sectors)
2327				DMERR("	 current stripe sectors %u vs new stripe sectors %u",
2328				      mddev->chunk_sectors, mddev->new_chunk_sectors);
2329			if (rs->delta_disks)
2330				DMERR("	 current %u disks vs new %u disks",
2331				      mddev->raid_disks, mddev->raid_disks + rs->delta_disks);
2332			if (rs_is_raid10(rs)) {
2333				DMERR("	 Old layout: %s w/ %u copies",
2334				      raid10_md_layout_to_format(mddev->layout),
2335				      raid10_md_layout_to_copies(mddev->layout));
2336				DMERR("	 New layout: %s w/ %u copies",
2337				      raid10_md_layout_to_format(mddev->new_layout),
2338				      raid10_md_layout_to_copies(mddev->new_layout));
2339			}
2340			return -EINVAL;
2341		}
2342
2343		DMINFO("Discovered old metadata format; upgrading to extended metadata format");
2344	}
2345
2346	if (!test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))
2347		mddev->recovery_cp = le64_to_cpu(sb->array_resync_offset);
2348
2349	/*
2350	 * During load, we set FirstUse if a new superblock was written.
2351	 * There are two reasons we might not have a superblock:
2352	 * 1) The raid set is brand new - in which case, all of the
2353	 *    devices must have their In_sync bit set.	Also,
2354	 *    recovery_cp must be 0, unless forced.
2355	 * 2) This is a new device being added to an old raid set
2356	 *    and the new device needs to be rebuilt - in which
2357	 *    case the In_sync bit will /not/ be set and
2358	 *    recovery_cp must be MaxSector.
2359	 * 3) This is/are a new device(s) being added to an old
2360	 *    raid set during takeover to a higher raid level
2361	 *    to provide capacity for redundancy or during reshape
2362	 *    to add capacity to grow the raid set.
2363	 */
2364	d = 0;
2365	rdev_for_each(r, mddev) {
2366		if (test_bit(Journal, &rdev->flags))
2367			continue;
2368
2369		if (test_bit(FirstUse, &r->flags))
2370			new_devs++;
2371
2372		if (!test_bit(In_sync, &r->flags)) {
2373			DMINFO("Device %d specified for rebuild; clearing superblock",
2374				r->raid_disk);
2375			rebuilds++;
2376
2377			if (test_bit(FirstUse, &r->flags))
2378				rebuild_and_new++;
2379		}
2380
2381		d++;
2382	}
2383
2384	if (new_devs == rs->raid_disks || !rebuilds) {
2385		/* Replace a broken device */
2386		if (new_devs == 1 && !rs->delta_disks)
2387			;
2388		if (new_devs == rs->raid_disks) {
2389			DMINFO("Superblocks created for new raid set");
2390			set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
2391		} else if (new_devs != rebuilds &&
2392			   new_devs != rs->delta_disks) {
2393			DMERR("New device injected into existing raid set without "
2394			      "'delta_disks' or 'rebuild' parameter specified");
2395			return -EINVAL;
2396		}
2397	} else if (new_devs && new_devs != rebuilds) {
2398		DMERR("%u 'rebuild' devices cannot be injected into"
2399		      " a raid set with %u other first-time devices",
2400		      rebuilds, new_devs);
2401		return -EINVAL;
2402	} else if (rebuilds) {
2403		if (rebuild_and_new && rebuilds != rebuild_and_new) {
2404			DMERR("new device%s provided without 'rebuild'",
2405			      new_devs > 1 ? "s" : "");
2406			return -EINVAL;
2407		} else if (!test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags) && rs_is_recovering(rs)) {
2408			DMERR("'rebuild' specified while raid set is not in-sync (recovery_cp=%llu)",
2409			      (unsigned long long) mddev->recovery_cp);
2410			return -EINVAL;
2411		} else if (rs_is_reshaping(rs)) {
2412			DMERR("'rebuild' specified while raid set is being reshaped (reshape_position=%llu)",
2413			      (unsigned long long) mddev->reshape_position);
2414			return -EINVAL;
2415		}
2416	}
2417
2418	/*
2419	 * Now we set the Faulty bit for those devices that are
2420	 * recorded in the superblock as failed.
2421	 */
2422	sb_retrieve_failed_devices(sb, failed_devices);
2423	rdev_for_each(r, mddev) {
2424		if (test_bit(Journal, &rdev->flags) ||
2425		    !r->sb_page)
2426			continue;
2427		sb2 = page_address(r->sb_page);
2428		sb2->failed_devices = 0;
2429		memset(sb2->extended_failed_devices, 0, sizeof(sb2->extended_failed_devices));
2430
2431		/*
2432		 * Check for any device re-ordering.
2433		 */
2434		if (!test_bit(FirstUse, &r->flags) && (r->raid_disk >= 0)) {
2435			role = le32_to_cpu(sb2->array_position);
2436			if (role < 0)
2437				continue;
2438
2439			if (role != r->raid_disk) {
2440				if (rs_is_raid10(rs) && __is_raid10_near(mddev->layout)) {
2441					if (mddev->raid_disks % __raid10_near_copies(mddev->layout) ||
2442					    rs->raid_disks % rs->raid10_copies) {
2443						rs->ti->error =
2444							"Cannot change raid10 near set to odd # of devices!";
2445						return -EINVAL;
2446					}
2447
2448					sb2->array_position = cpu_to_le32(r->raid_disk);
2449
2450				} else if (!(rs_is_raid10(rs) && rt_is_raid0(rs->raid_type)) &&
2451					   !(rs_is_raid0(rs) && rt_is_raid10(rs->raid_type)) &&
2452					   !rt_is_raid1(rs->raid_type)) {
2453					rs->ti->error = "Cannot change device positions in raid set";
2454					return -EINVAL;
2455				}
2456
2457				DMINFO("raid device #%d now at position #%d", role, r->raid_disk);
2458			}
2459
2460			/*
2461			 * Partial recovery is performed on
2462			 * returning failed devices.
2463			 */
2464			if (test_bit(role, (void *) failed_devices))
2465				set_bit(Faulty, &r->flags);
2466		}
2467	}
2468
2469	return 0;
2470}
2471
2472static int super_validate(struct raid_set *rs, struct md_rdev *rdev)
2473{
2474	struct mddev *mddev = &rs->md;
2475	struct dm_raid_superblock *sb;
2476
2477	if (rs_is_raid0(rs) || !rdev->sb_page || rdev->raid_disk < 0)
2478		return 0;
2479
2480	sb = page_address(rdev->sb_page);
2481
2482	/*
2483	 * If mddev->events is not set, we know we have not yet initialized
2484	 * the array.
2485	 */
2486	if (!mddev->events && super_init_validation(rs, rdev))
2487		return -EINVAL;
2488
2489	if (le32_to_cpu(sb->compat_features) &&
2490	    le32_to_cpu(sb->compat_features) != FEATURE_FLAG_SUPPORTS_V190) {
2491		rs->ti->error = "Unable to assemble array: Unknown flag(s) in compatible feature flags";
2492		return -EINVAL;
2493	}
2494
2495	if (sb->incompat_features) {
2496		rs->ti->error = "Unable to assemble array: No incompatible feature flags supported yet";
2497		return -EINVAL;
2498	}
2499
2500	/* Enable bitmap creation for RAID levels != 0 */
2501	mddev->bitmap_info.offset = rt_is_raid0(rs->raid_type) ? 0 : to_sector(4096);
2502	mddev->bitmap_info.default_offset = mddev->bitmap_info.offset;
2503
2504	if (!test_and_clear_bit(FirstUse, &rdev->flags)) {
2505		/*
2506		 * Retrieve rdev size stored in superblock to be prepared for shrink.
2507		 * Check extended superblock members are present otherwise the size
2508		 * will not be set!
2509		 */
2510		if (le32_to_cpu(sb->compat_features) & FEATURE_FLAG_SUPPORTS_V190)
2511			rdev->sectors = le64_to_cpu(sb->sectors);
2512
2513		rdev->recovery_offset = le64_to_cpu(sb->disk_recovery_offset);
2514		if (rdev->recovery_offset == MaxSector)
2515			set_bit(In_sync, &rdev->flags);
2516		/*
2517		 * If no reshape in progress -> we're recovering single
2518		 * disk(s) and have to set the device(s) to out-of-sync
2519		 */
2520		else if (!rs_is_reshaping(rs))
2521			clear_bit(In_sync, &rdev->flags); /* Mandatory for recovery */
2522	}
2523
2524	/*
2525	 * If a device comes back, set it as not In_sync and no longer faulty.
2526	 */
2527	if (test_and_clear_bit(Faulty, &rdev->flags)) {
2528		rdev->recovery_offset = 0;
2529		clear_bit(In_sync, &rdev->flags);
2530		rdev->saved_raid_disk = rdev->raid_disk;
2531	}
2532
2533	/* Reshape support -> restore repective data offsets */
2534	rdev->data_offset = le64_to_cpu(sb->data_offset);
2535	rdev->new_data_offset = le64_to_cpu(sb->new_data_offset);
2536
2537	return 0;
2538}
2539
2540/*
2541 * Analyse superblocks and select the freshest.
2542 */
2543static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
2544{
2545	int r;
2546	struct md_rdev *rdev, *freshest;
2547	struct mddev *mddev = &rs->md;
2548
2549	freshest = NULL;
2550	rdev_for_each(rdev, mddev) {
2551		if (test_bit(Journal, &rdev->flags))
2552			continue;
2553
2554		if (!rdev->meta_bdev)
2555			continue;
2556
2557		/* Set superblock offset/size for metadata device. */
2558		rdev->sb_start = 0;
2559		rdev->sb_size = bdev_logical_block_size(rdev->meta_bdev);
2560		if (rdev->sb_size < sizeof(struct dm_raid_superblock) || rdev->sb_size > PAGE_SIZE) {
2561			DMERR("superblock size of a logical block is no longer valid");
2562			return -EINVAL;
2563		}
2564
2565		/*
2566		 * Skipping super_load due to CTR_FLAG_SYNC will cause
2567		 * the array to undergo initialization again as
2568		 * though it were new.	This is the intended effect
2569		 * of the "sync" directive.
2570		 *
2571		 * With reshaping capability added, we must ensure that
2572		 * that the "sync" directive is disallowed during the reshape.
2573		 */
2574		if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags))
2575			continue;
2576
2577		r = super_load(rdev, freshest);
2578
2579		switch (r) {
2580		case 1:
2581			freshest = rdev;
2582			break;
2583		case 0:
2584			break;
2585		default:
2586			/* This is a failure to read the superblock from the metadata device. */
2587			/*
2588			 * We have to keep any raid0 data/metadata device pairs or
2589			 * the MD raid0 personality will fail to start the array.
2590			 */
2591			if (rs_is_raid0(rs))
2592				continue;
2593
2594			/*
2595			 * We keep the dm_devs to be able to emit the device tuple
2596			 * properly on the table line in raid_status() (rather than
2597			 * mistakenly acting as if '- -' got passed into the constructor).
2598			 *
2599			 * The rdev has to stay on the same_set list to allow for
2600			 * the attempt to restore faulty devices on second resume.
2601			 */
2602			rdev->raid_disk = rdev->saved_raid_disk = -1;
2603			break;
2604		}
2605	}
2606
2607	if (!freshest)
2608		return 0;
2609
2610	/*
2611	 * Validation of the freshest device provides the source of
2612	 * validation for the remaining devices.
2613	 */
2614	rs->ti->error = "Unable to assemble array: Invalid superblocks";
2615	if (super_validate(rs, freshest))
2616		return -EINVAL;
2617
2618	if (validate_raid_redundancy(rs)) {
2619		rs->ti->error = "Insufficient redundancy to activate array";
2620		return -EINVAL;
2621	}
2622
2623	rdev_for_each(rdev, mddev)
2624		if (!test_bit(Journal, &rdev->flags) &&
2625		    rdev != freshest &&
2626		    super_validate(rs, rdev))
2627			return -EINVAL;
2628	return 0;
2629}
2630
2631/*
2632 * Adjust data_offset and new_data_offset on all disk members of @rs
2633 * for out of place reshaping if requested by contructor
2634 *
2635 * We need free space at the beginning of each raid disk for forward
2636 * and at the end for backward reshapes which userspace has to provide
2637 * via remapping/reordering of space.
2638 */
2639static int rs_adjust_data_offsets(struct raid_set *rs)
2640{
2641	sector_t data_offset = 0, new_data_offset = 0;
2642	struct md_rdev *rdev;
2643
2644	/* Constructor did not request data offset change */
2645	if (!test_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags)) {
2646		if (!rs_is_reshapable(rs))
2647			goto out;
2648
2649		return 0;
2650	}
2651
2652	/* HM FIXME: get InSync raid_dev? */
2653	rdev = &rs->dev[0].rdev;
2654
2655	if (rs->delta_disks < 0) {
2656		/*
2657		 * Removing disks (reshaping backwards):
2658		 *
2659		 * - before reshape: data is at offset 0 and free space
2660		 *		     is at end of each component LV
2661		 *
2662		 * - after reshape: data is at offset rs->data_offset != 0 on each component LV
2663		 */
2664		data_offset = 0;
2665		new_data_offset = rs->data_offset;
2666
2667	} else if (rs->delta_disks > 0) {
2668		/*
2669		 * Adding disks (reshaping forwards):
2670		 *
2671		 * - before reshape: data is at offset rs->data_offset != 0 and
2672		 *		     free space is at begin of each component LV
2673		 *
2674		 * - after reshape: data is at offset 0 on each component LV
2675		 */
2676		data_offset = rs->data_offset;
2677		new_data_offset = 0;
2678
2679	} else {
2680		/*
2681		 * User space passes in 0 for data offset after having removed reshape space
2682		 *
2683		 * - or - (data offset != 0)
2684		 *
2685		 * Changing RAID layout or chunk size -> toggle offsets
2686		 *
2687		 * - before reshape: data is at offset rs->data_offset 0 and
2688		 *		     free space is at end of each component LV
2689		 *		     -or-
2690		 *                   data is at offset rs->data_offset != 0 and
2691		 *		     free space is at begin of each component LV
2692		 *
2693		 * - after reshape: data is at offset 0 if it was at offset != 0
2694		 *                  or at offset != 0 if it was at offset 0
2695		 *                  on each component LV
2696		 *
2697		 */
2698		data_offset = rs->data_offset ? rdev->data_offset : 0;
2699		new_data_offset = data_offset ? 0 : rs->data_offset;
2700		set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2701	}
2702
2703	/*
2704	 * Make sure we got a minimum amount of free sectors per device
2705	 */
2706	if (rs->data_offset &&
2707	    to_sector(i_size_read(rdev->bdev->bd_inode)) - rs->md.dev_sectors < MIN_FREE_RESHAPE_SPACE) {
2708		rs->ti->error = data_offset ? "No space for forward reshape" :
2709					      "No space for backward reshape";
2710		return -ENOSPC;
2711	}
2712out:
2713	/*
2714	 * Raise recovery_cp in case data_offset != 0 to
2715	 * avoid false recovery positives in the constructor.
2716	 */
2717	if (rs->md.recovery_cp < rs->md.dev_sectors)
2718		rs->md.recovery_cp += rs->dev[0].rdev.data_offset;
2719
2720	/* Adjust data offsets on all rdevs but on any raid4/5/6 journal device */
2721	rdev_for_each(rdev, &rs->md) {
2722		if (!test_bit(Journal, &rdev->flags)) {
2723			rdev->data_offset = data_offset;
2724			rdev->new_data_offset = new_data_offset;
2725		}
2726	}
2727
2728	return 0;
2729}
2730
2731/* Userpace reordered disks -> adjust raid_disk indexes in @rs */
2732static void __reorder_raid_disk_indexes(struct raid_set *rs)
2733{
2734	int i = 0;
2735	struct md_rdev *rdev;
2736
2737	rdev_for_each(rdev, &rs->md) {
2738		if (!test_bit(Journal, &rdev->flags)) {
2739			rdev->raid_disk = i++;
2740			rdev->saved_raid_disk = rdev->new_raid_disk = -1;
2741		}
2742	}
2743}
2744
2745/*
2746 * Setup @rs for takeover by a different raid level
2747 */
2748static int rs_setup_takeover(struct raid_set *rs)
2749{
2750	struct mddev *mddev = &rs->md;
2751	struct md_rdev *rdev;
2752	unsigned int d = mddev->raid_disks = rs->raid_disks;
2753	sector_t new_data_offset = rs->dev[0].rdev.data_offset ? 0 : rs->data_offset;
2754
2755	if (rt_is_raid10(rs->raid_type)) {
2756		if (rs_is_raid0(rs)) {
2757			/* Userpace reordered disks -> adjust raid_disk indexes */
2758			__reorder_raid_disk_indexes(rs);
2759
2760			/* raid0 -> raid10_far layout */
2761			mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_FAR,
2762								   rs->raid10_copies);
2763		} else if (rs_is_raid1(rs))
2764			/* raid1 -> raid10_near layout */
2765			mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_NEAR,
2766								   rs->raid_disks);
2767		else
2768			return -EINVAL;
2769
2770	}
2771
2772	clear_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
2773	mddev->recovery_cp = MaxSector;
2774
2775	while (d--) {
2776		rdev = &rs->dev[d].rdev;
2777
2778		if (test_bit(d, (void *) rs->rebuild_disks)) {
2779			clear_bit(In_sync, &rdev->flags);
2780			clear_bit(Faulty, &rdev->flags);
2781			mddev->recovery_cp = rdev->recovery_offset = 0;
2782			/* Bitmap has to be created when we do an "up" takeover */
2783			set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
2784		}
2785
2786		rdev->new_data_offset = new_data_offset;
2787	}
2788
2789	return 0;
2790}
2791
2792/* Prepare @rs for reshape */
2793static int rs_prepare_reshape(struct raid_set *rs)
2794{
2795	bool reshape;
2796	struct mddev *mddev = &rs->md;
2797
2798	if (rs_is_raid10(rs)) {
2799		if (rs->raid_disks != mddev->raid_disks &&
2800		    __is_raid10_near(mddev->layout) &&
2801		    rs->raid10_copies &&
2802		    rs->raid10_copies != __raid10_near_copies(mddev->layout)) {
2803			/*
2804			 * raid disk have to be multiple of data copies to allow this conversion,
2805			 *
2806			 * This is actually not a reshape it is a
2807			 * rebuild of any additional mirrors per group
2808			 */
2809			if (rs->raid_disks % rs->raid10_copies) {
2810				rs->ti->error = "Can't reshape raid10 mirror groups";
2811				return -EINVAL;
2812			}
2813
2814			/* Userpace reordered disks to add/remove mirrors -> adjust raid_disk indexes */
2815			__reorder_raid_disk_indexes(rs);
2816			mddev->layout = raid10_format_to_md_layout(rs, ALGORITHM_RAID10_NEAR,
2817								   rs->raid10_copies);
2818			mddev->new_layout = mddev->layout;
2819			reshape = false;
2820		} else
2821			reshape = true;
2822
2823	} else if (rs_is_raid456(rs))
2824		reshape = true;
2825
2826	else if (rs_is_raid1(rs)) {
2827		if (rs->delta_disks) {
2828			/* Process raid1 via delta_disks */
2829			mddev->degraded = rs->delta_disks < 0 ? -rs->delta_disks : rs->delta_disks;
2830			reshape = true;
2831		} else {
2832			/* Process raid1 without delta_disks */
2833			mddev->raid_disks = rs->raid_disks;
2834			reshape = false;
2835		}
2836	} else {
2837		rs->ti->error = "Called with bogus raid type";
2838		return -EINVAL;
2839	}
2840
2841	if (reshape) {
2842		set_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags);
2843		set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2844	} else if (mddev->raid_disks < rs->raid_disks)
2845		/* Create new superblocks and bitmaps, if any new disks */
2846		set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
2847
2848	return 0;
2849}
2850
2851/* Get reshape sectors from data_offsets or raid set */
2852static sector_t _get_reshape_sectors(struct raid_set *rs)
2853{
2854	struct md_rdev *rdev;
2855	sector_t reshape_sectors = 0;
2856
2857	rdev_for_each(rdev, &rs->md)
2858		if (!test_bit(Journal, &rdev->flags)) {
2859			reshape_sectors = (rdev->data_offset > rdev->new_data_offset) ?
2860					rdev->data_offset - rdev->new_data_offset :
2861					rdev->new_data_offset - rdev->data_offset;
2862			break;
2863		}
2864
2865	return max(reshape_sectors, (sector_t) rs->data_offset);
2866}
2867
2868/*
2869 *
2870 * - change raid layout
2871 * - change chunk size
2872 * - add disks
2873 * - remove disks
2874 */
2875static int rs_setup_reshape(struct raid_set *rs)
2876{
2877	int r = 0;
2878	unsigned int cur_raid_devs, d;
2879	sector_t reshape_sectors = _get_reshape_sectors(rs);
2880	struct mddev *mddev = &rs->md;
2881	struct md_rdev *rdev;
2882
2883	mddev->delta_disks = rs->delta_disks;
2884	cur_raid_devs = mddev->raid_disks;
2885
2886	/* Ignore impossible layout change whilst adding/removing disks */
2887	if (mddev->delta_disks &&
2888	    mddev->layout != mddev->new_layout) {
2889		DMINFO("Ignoring invalid layout change with delta_disks=%d", rs->delta_disks);
2890		mddev->new_layout = mddev->layout;
2891	}
2892
2893	/*
2894	 * Adjust array size:
2895	 *
2896	 * - in case of adding disk(s), array size has
2897	 *   to grow after the disk adding reshape,
2898	 *   which'll hapen in the event handler;
2899	 *   reshape will happen forward, so space has to
2900	 *   be available at the beginning of each disk
2901	 *
2902	 * - in case of removing disk(s), array size
2903	 *   has to shrink before starting the reshape,
2904	 *   which'll happen here;
2905	 *   reshape will happen backward, so space has to
2906	 *   be available at the end of each disk
2907	 *
2908	 * - data_offset and new_data_offset are
2909	 *   adjusted for aforementioned out of place
2910	 *   reshaping based on userspace passing in
2911	 *   the "data_offset <sectors>" key/value
2912	 *   pair via the constructor
2913	 */
2914
2915	/* Add disk(s) */
2916	if (rs->delta_disks > 0) {
2917		/* Prepare disks for check in raid4/5/6/10 {check|start}_reshape */
2918		for (d = cur_raid_devs; d < rs->raid_disks; d++) {
2919			rdev = &rs->dev[d].rdev;
2920			clear_bit(In_sync, &rdev->flags);
2921
2922			/*
2923			 * save_raid_disk needs to be -1, or recovery_offset will be set to 0
2924			 * by md, which'll store that erroneously in the superblock on reshape
2925			 */
2926			rdev->saved_raid_disk = -1;
2927			rdev->raid_disk = d;
2928
2929			rdev->sectors = mddev->dev_sectors;
2930			rdev->recovery_offset = rs_is_raid1(rs) ? 0 : MaxSector;
2931		}
2932
2933		mddev->reshape_backwards = 0; /* adding disk(s) -> forward reshape */
2934
2935	/* Remove disk(s) */
2936	} else if (rs->delta_disks < 0) {
2937		r = rs_set_dev_and_array_sectors(rs, true);
2938		mddev->reshape_backwards = 1; /* removing disk(s) -> backward reshape */
2939
2940	/* Change layout and/or chunk size */
2941	} else {
2942		/*
2943		 * Reshape layout (e.g. raid5_ls -> raid5_n) and/or chunk size:
2944		 *
2945		 * keeping number of disks and do layout change ->
2946		 *
2947		 * toggle reshape_backward depending on data_offset:
2948		 *
2949		 * - free space upfront -> reshape forward
2950		 *
2951		 * - free space at the end -> reshape backward
2952		 *
2953		 *
2954		 * This utilizes free reshape space avoiding the need
2955		 * for userspace to move (parts of) LV segments in
2956		 * case of layout/chunksize change  (for disk
2957		 * adding/removing reshape space has to be at
2958		 * the proper address (see above with delta_disks):
2959		 *
2960		 * add disk(s)   -> begin
2961		 * remove disk(s)-> end
2962		 */
2963		mddev->reshape_backwards = rs->dev[0].rdev.data_offset ? 0 : 1;
2964	}
2965
2966	/*
2967	 * Adjust device size for forward reshape
2968	 * because md_finish_reshape() reduces it.
2969	 */
2970	if (!mddev->reshape_backwards)
2971		rdev_for_each(rdev, &rs->md)
2972			if (!test_bit(Journal, &rdev->flags))
2973				rdev->sectors += reshape_sectors;
2974
2975	return r;
2976}
2977
2978/*
 
 
 
 
 
 
 
 
 
 
 
 
 
 
2979 * Enable/disable discard support on RAID set depending on
2980 * RAID level and discard properties of underlying RAID members.
2981 */
2982static void configure_discard_support(struct raid_set *rs)
2983{
2984	int i;
2985	bool raid456;
2986	struct dm_target *ti = rs->ti;
2987
2988	/*
2989	 * XXX: RAID level 4,5,6 require zeroing for safety.
2990	 */
2991	raid456 = rs_is_raid456(rs);
2992
2993	for (i = 0; i < rs->raid_disks; i++) {
2994		struct request_queue *q;
2995
2996		if (!rs->dev[i].rdev.bdev)
2997			continue;
2998
2999		q = bdev_get_queue(rs->dev[i].rdev.bdev);
3000		if (!q || !blk_queue_discard(q))
3001			return;
3002
3003		if (raid456) {
3004			if (!devices_handle_discard_safely) {
3005				DMERR("raid456 discard support disabled due to discard_zeroes_data uncertainty.");
3006				DMERR("Set dm-raid.devices_handle_discard_safely=Y to override.");
3007				return;
3008			}
3009		}
3010	}
3011
3012	/*
3013	 * RAID1 and RAID10 personalities require bio splitting,
3014	 * RAID0/4/5/6 don't and process large discard bios properly.
3015	 */
3016	ti->split_discard_bios = !!(rs_is_raid1(rs) || rs_is_raid10(rs));
3017	ti->num_discard_bios = 1;
3018}
3019
3020/*
3021 * Construct a RAID0/1/10/4/5/6 mapping:
3022 * Args:
3023 *	<raid_type> <#raid_params> <raid_params>{0,}	\
3024 *	<#raid_devs> [<meta_dev1> <dev1>]{1,}
3025 *
3026 * <raid_params> varies by <raid_type>.	 See 'parse_raid_params' for
3027 * details on possible <raid_params>.
3028 *
3029 * Userspace is free to initialize the metadata devices, hence the superblocks to
3030 * enforce recreation based on the passed in table parameters.
3031 *
3032 */
3033static int raid_ctr(struct dm_target *ti, unsigned int argc, char **argv)
3034{
3035	int r;
3036	bool resize = false;
3037	struct raid_type *rt;
3038	unsigned int num_raid_params, num_raid_devs;
3039	sector_t calculated_dev_sectors, rdev_sectors, reshape_sectors;
3040	struct raid_set *rs = NULL;
3041	const char *arg;
3042	struct rs_layout rs_layout;
3043	struct dm_arg_set as = { argc, argv }, as_nrd;
3044	struct dm_arg _args[] = {
3045		{ 0, as.argc, "Cannot understand number of raid parameters" },
3046		{ 1, 254, "Cannot understand number of raid devices parameters" }
3047	};
3048
3049	/* Must have <raid_type> */
3050	arg = dm_shift_arg(&as);
3051	if (!arg) {
3052		ti->error = "No arguments";
3053		return -EINVAL;
3054	}
3055
3056	rt = get_raid_type(arg);
3057	if (!rt) {
3058		ti->error = "Unrecognised raid_type";
3059		return -EINVAL;
3060	}
3061
3062	/* Must have <#raid_params> */
3063	if (dm_read_arg_group(_args, &as, &num_raid_params, &ti->error))
3064		return -EINVAL;
3065
3066	/* number of raid device tupples <meta_dev data_dev> */
3067	as_nrd = as;
3068	dm_consume_args(&as_nrd, num_raid_params);
3069	_args[1].max = (as_nrd.argc - 1) / 2;
3070	if (dm_read_arg(_args + 1, &as_nrd, &num_raid_devs, &ti->error))
3071		return -EINVAL;
3072
3073	if (!__within_range(num_raid_devs, 1, MAX_RAID_DEVICES)) {
3074		ti->error = "Invalid number of supplied raid devices";
3075		return -EINVAL;
3076	}
3077
3078	rs = raid_set_alloc(ti, rt, num_raid_devs);
3079	if (IS_ERR(rs))
3080		return PTR_ERR(rs);
3081
3082	r = parse_raid_params(rs, &as, num_raid_params);
3083	if (r)
3084		goto bad;
3085
3086	r = parse_dev_params(rs, &as);
3087	if (r)
3088		goto bad;
3089
3090	rs->md.sync_super = super_sync;
3091
3092	/*
3093	 * Calculate ctr requested array and device sizes to allow
3094	 * for superblock analysis needing device sizes defined.
3095	 *
3096	 * Any existing superblock will overwrite the array and device sizes
3097	 */
3098	r = rs_set_dev_and_array_sectors(rs, false);
3099	if (r)
3100		goto bad;
3101
3102	calculated_dev_sectors = rs->md.dev_sectors;
 
 
3103
3104	/*
3105	 * Backup any new raid set level, layout, ...
3106	 * requested to be able to compare to superblock
3107	 * members for conversion decisions.
3108	 */
3109	rs_config_backup(rs, &rs_layout);
3110
3111	r = analyse_superblocks(ti, rs);
3112	if (r)
3113		goto bad;
3114
 
 
3115	rdev_sectors = __rdev_sectors(rs);
3116	if (!rdev_sectors) {
3117		ti->error = "Invalid rdev size";
3118		r = -EINVAL;
3119		goto bad;
3120	}
3121
3122
3123	reshape_sectors = _get_reshape_sectors(rs);
3124	if (calculated_dev_sectors != rdev_sectors)
3125		resize = calculated_dev_sectors != (reshape_sectors ? rdev_sectors - reshape_sectors : rdev_sectors);
 
 
 
3126
3127	INIT_WORK(&rs->md.event_work, do_table_event);
3128	ti->private = rs;
3129	ti->num_flush_bios = 1;
 
3130
3131	/* Restore any requested new layout for conversion decision */
3132	rs_config_restore(rs, &rs_layout);
3133
3134	/*
3135	 * Now that we have any superblock metadata available,
3136	 * check for new, recovering, reshaping, to be taken over,
3137	 * to be reshaped or an existing, unchanged raid set to
3138	 * run in sequence.
3139	 */
3140	if (test_bit(MD_ARRAY_FIRST_USE, &rs->md.flags)) {
3141		/* A new raid6 set has to be recovered to ensure proper parity and Q-Syndrome */
3142		if (rs_is_raid6(rs) &&
3143		    test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags)) {
3144			ti->error = "'nosync' not allowed for new raid6 set";
3145			r = -EINVAL;
3146			goto bad;
3147		}
3148		rs_setup_recovery(rs, 0);
3149		set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
3150		rs_set_new(rs);
3151	} else if (rs_is_recovering(rs)) {
3152		/* A recovering raid set may be resized */
3153		; /* skip setup rs */
3154	} else if (rs_is_reshaping(rs)) {
3155		/* Have to reject size change request during reshape */
3156		if (resize) {
3157			ti->error = "Can't resize a reshaping raid set";
3158			r = -EPERM;
3159			goto bad;
3160		}
3161		/* skip setup rs */
3162	} else if (rs_takeover_requested(rs)) {
3163		if (rs_is_reshaping(rs)) {
3164			ti->error = "Can't takeover a reshaping raid set";
3165			r = -EPERM;
3166			goto bad;
3167		}
3168
3169		/* We can't takeover a journaled raid4/5/6 */
3170		if (test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
3171			ti->error = "Can't takeover a journaled raid4/5/6 set";
3172			r = -EPERM;
3173			goto bad;
3174		}
3175
3176		/*
3177		 * If a takeover is needed, userspace sets any additional
3178		 * devices to rebuild and we can check for a valid request here.
3179		 *
3180		 * If acceptible, set the level to the new requested
3181		 * one, prohibit requesting recovery, allow the raid
3182		 * set to run and store superblocks during resume.
3183		 */
3184		r = rs_check_takeover(rs);
3185		if (r)
3186			goto bad;
3187
3188		r = rs_setup_takeover(rs);
3189		if (r)
3190			goto bad;
3191
3192		set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
3193		/* Takeover ain't recovery, so disable recovery */
3194		rs_setup_recovery(rs, MaxSector);
3195		rs_set_new(rs);
3196	} else if (rs_reshape_requested(rs)) {
 
 
 
3197		/*
3198		 * No need to check for 'ongoing' takeover here, because takeover
3199		 * is an instant operation as oposed to an ongoing reshape.
3200		 */
3201
3202		/* We can't reshape a journaled raid4/5/6 */
3203		if (test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags)) {
3204			ti->error = "Can't reshape a journaled raid4/5/6 set";
3205			r = -EPERM;
3206			goto bad;
3207		}
3208
3209		/* Out-of-place space has to be available to allow for a reshape unless raid1! */
3210		if (reshape_sectors || rs_is_raid1(rs)) {
3211			/*
3212			  * We can only prepare for a reshape here, because the
3213			  * raid set needs to run to provide the repective reshape
3214			  * check functions via its MD personality instance.
3215			  *
3216			  * So do the reshape check after md_run() succeeded.
3217			  */
3218			r = rs_prepare_reshape(rs);
3219			if (r)
3220				return r;
3221
3222			/* Reshaping ain't recovery, so disable recovery */
3223			rs_setup_recovery(rs, MaxSector);
3224		}
3225		rs_set_cur(rs);
3226	} else {
 
3227		/* May not set recovery when a device rebuild is requested */
3228		if (test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags)) {
 
 
3229			rs_setup_recovery(rs, MaxSector);
3230			set_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags);
3231		} else
3232			rs_setup_recovery(rs, test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags) ?
3233					      0 : (resize ? calculated_dev_sectors : MaxSector));
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3234		rs_set_cur(rs);
3235	}
3236
3237	/* If constructor requested it, change data and new_data offsets */
3238	r = rs_adjust_data_offsets(rs);
3239	if (r)
3240		goto bad;
3241
 
 
 
3242	/* Start raid set read-only and assumed clean to change in raid_resume() */
3243	rs->md.ro = 1;
3244	rs->md.in_sync = 1;
 
 
3245	set_bit(MD_RECOVERY_FROZEN, &rs->md.recovery);
3246
3247	/* Has to be held on running the array */
3248	mddev_lock_nointr(&rs->md);
3249	r = md_run(&rs->md);
3250	rs->md.in_sync = 0; /* Assume already marked dirty */
3251	if (r) {
3252		ti->error = "Failed to run raid array";
3253		mddev_unlock(&rs->md);
3254		goto bad;
3255	}
3256
3257	r = md_start(&rs->md);
3258
3259	if (r) {
3260		ti->error = "Failed to start raid array";
3261		mddev_unlock(&rs->md);
3262		goto bad_md_start;
3263	}
3264
3265	rs->callbacks.congested_fn = raid_is_congested;
3266	dm_table_add_target_callbacks(ti->table, &rs->callbacks);
3267
3268	/* If raid4/5/6 journal mode explictely requested (only possible with journal dev) -> set it */
3269	if (test_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags)) {
3270		r = r5c_journal_mode_set(&rs->md, rs->journal_dev.mode);
3271		if (r) {
3272			ti->error = "Failed to set raid4/5/6 journal mode";
3273			mddev_unlock(&rs->md);
3274			goto bad_journal_mode_set;
3275		}
3276	}
3277
3278	mddev_suspend(&rs->md);
3279	set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags);
3280
3281	/* Try to adjust the raid4/5/6 stripe cache size to the stripe size */
3282	if (rs_is_raid456(rs)) {
3283		r = rs_set_raid456_stripe_cache(rs);
3284		if (r)
3285			goto bad_stripe_cache;
3286	}
3287
3288	/* Now do an early reshape check */
3289	if (test_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags)) {
3290		r = rs_check_reshape(rs);
3291		if (r)
3292			goto bad_check_reshape;
3293
3294		/* Restore new, ctr requested layout to perform check */
3295		rs_config_restore(rs, &rs_layout);
3296
3297		if (rs->md.pers->start_reshape) {
3298			r = rs->md.pers->check_reshape(&rs->md);
3299			if (r) {
3300				ti->error = "Reshape check failed";
3301				goto bad_check_reshape;
3302			}
3303		}
3304	}
3305
3306	/* Disable/enable discard support on raid set. */
3307	configure_discard_support(rs);
3308
3309	mddev_unlock(&rs->md);
3310	return 0;
3311
3312bad_md_start:
3313bad_journal_mode_set:
3314bad_stripe_cache:
3315bad_check_reshape:
3316	md_stop(&rs->md);
3317bad:
3318	raid_set_free(rs);
3319
3320	return r;
3321}
3322
3323static void raid_dtr(struct dm_target *ti)
3324{
3325	struct raid_set *rs = ti->private;
3326
3327	list_del_init(&rs->callbacks.list);
3328	md_stop(&rs->md);
3329	raid_set_free(rs);
3330}
3331
3332static int raid_map(struct dm_target *ti, struct bio *bio)
3333{
3334	struct raid_set *rs = ti->private;
3335	struct mddev *mddev = &rs->md;
3336
3337	/*
3338	 * If we're reshaping to add disk(s)), ti->len and
3339	 * mddev->array_sectors will differ during the process
3340	 * (ti->len > mddev->array_sectors), so we have to requeue
3341	 * bios with addresses > mddev->array_sectors here or
3342	 * there will occur accesses past EOD of the component
3343	 * data images thus erroring the raid set.
3344	 */
3345	if (unlikely(bio_end_sector(bio) > mddev->array_sectors))
3346		return DM_MAPIO_REQUEUE;
3347
3348	md_handle_request(mddev, bio);
3349
3350	return DM_MAPIO_SUBMITTED;
3351}
3352
3353/* Return string describing the current sync action of @mddev */
3354static const char *decipher_sync_action(struct mddev *mddev, unsigned long recovery)
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3355{
3356	if (test_bit(MD_RECOVERY_FROZEN, &recovery))
3357		return "frozen";
3358
3359	/* The MD sync thread can be done with io but still be running */
3360	if (!test_bit(MD_RECOVERY_DONE, &recovery) &&
3361	    (test_bit(MD_RECOVERY_RUNNING, &recovery) ||
3362	     (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &recovery)))) {
3363		if (test_bit(MD_RECOVERY_RESHAPE, &recovery))
3364			return "reshape";
3365
3366		if (test_bit(MD_RECOVERY_SYNC, &recovery)) {
3367			if (!test_bit(MD_RECOVERY_REQUESTED, &recovery))
3368				return "resync";
3369			else if (test_bit(MD_RECOVERY_CHECK, &recovery))
3370				return "check";
3371			return "repair";
3372		}
3373
3374		if (test_bit(MD_RECOVERY_RECOVER, &recovery))
3375			return "recover";
 
 
 
3376	}
3377
3378	return "idle";
3379}
3380
3381/*
3382 * Return status string for @rdev
3383 *
3384 * Status characters:
3385 *
3386 *  'D' = Dead/Failed raid set component or raid4/5/6 journal device
3387 *  'a' = Alive but not in-sync raid set component _or_ alive raid4/5/6 'write_back' journal device
3388 *  'A' = Alive and in-sync raid set component _or_ alive raid4/5/6 'write_through' journal device
3389 *  '-' = Non-existing device (i.e. uspace passed '- -' into the ctr)
3390 */
3391static const char *__raid_dev_status(struct raid_set *rs, struct md_rdev *rdev)
3392{
3393	if (!rdev->bdev)
3394		return "-";
3395	else if (test_bit(Faulty, &rdev->flags))
3396		return "D";
3397	else if (test_bit(Journal, &rdev->flags))
3398		return (rs->journal_dev.mode == R5C_JOURNAL_MODE_WRITE_THROUGH) ? "A" : "a";
3399	else if (test_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags) ||
3400		 (!test_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags) &&
3401		  !test_bit(In_sync, &rdev->flags)))
3402		return "a";
3403	else
3404		return "A";
3405}
3406
3407/* Helper to return resync/reshape progress for @rs and runtime flags for raid set in sync / resynching */
3408static sector_t rs_get_progress(struct raid_set *rs, unsigned long recovery,
3409				sector_t resync_max_sectors)
3410{
3411	sector_t r;
3412	struct mddev *mddev = &rs->md;
3413
3414	clear_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3415	clear_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags);
3416
3417	if (rs_is_raid0(rs)) {
3418		r = resync_max_sectors;
3419		set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3420
3421	} else {
3422		if (!test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags) &&
3423		    !test_bit(MD_RECOVERY_INTR, &recovery) &&
3424		    (test_bit(MD_RECOVERY_NEEDED, &recovery) ||
3425		     test_bit(MD_RECOVERY_RESHAPE, &recovery) ||
3426		     test_bit(MD_RECOVERY_RUNNING, &recovery)))
3427			r = mddev->curr_resync_completed;
3428		else
3429			r = mddev->recovery_cp;
3430
3431		if (r >= resync_max_sectors &&
3432		    (!test_bit(MD_RECOVERY_REQUESTED, &recovery) ||
3433		     (!test_bit(MD_RECOVERY_FROZEN, &recovery) &&
3434		      !test_bit(MD_RECOVERY_NEEDED, &recovery) &&
3435		      !test_bit(MD_RECOVERY_RUNNING, &recovery)))) {
3436			/*
3437			 * Sync complete.
3438			 */
3439			/* In case we have finished recovering, the array is in sync. */
3440			if (test_bit(MD_RECOVERY_RECOVER, &recovery))
3441				set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3442
3443		} else if (test_bit(MD_RECOVERY_RECOVER, &recovery)) {
3444			/*
3445			 * In case we are recovering, the array is not in sync
3446			 * and health chars should show the recovering legs.
 
 
3447			 */
3448			;
3449
3450		} else if (test_bit(MD_RECOVERY_SYNC, &recovery) &&
3451			   !test_bit(MD_RECOVERY_REQUESTED, &recovery)) {
3452			/*
3453			 * If "resync" is occurring, the raid set
3454			 * is or may be out of sync hence the health
3455			 * characters shall be 'a'.
3456			 */
3457			set_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags);
3458
3459		} else if (test_bit(MD_RECOVERY_RESHAPE, &recovery) &&
3460			   !test_bit(MD_RECOVERY_REQUESTED, &recovery)) {
3461			/*
3462			 * If "reshape" is occurring, the raid set
3463			 * is or may be out of sync hence the health
3464			 * characters shall be 'a'.
3465			 */
3466			set_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags);
3467
3468		} else if (test_bit(MD_RECOVERY_REQUESTED, &recovery)) {
3469			/*
3470			 * If "check" or "repair" is occurring, the raid set has
3471			 * undergone an initial sync and the health characters
3472			 * should not be 'a' anymore.
3473			 */
3474			set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3475
3476		} else {
3477			struct md_rdev *rdev;
3478
3479			/*
3480			 * We are idle and recovery is needed, prevent 'A' chars race
3481			 * caused by components still set to in-sync by constrcuctor.
3482			 */
3483			if (test_bit(MD_RECOVERY_NEEDED, &recovery))
3484				set_bit(RT_FLAG_RS_RESYNCING, &rs->runtime_flags);
3485
 
3486			/*
3487			 * The raid set may be doing an initial sync, or it may
3488			 * be rebuilding individual components.	 If all the
3489			 * devices are In_sync, then it is the raid set that is
3490			 * being initialized.
3491			 */
 
 
3492			set_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3493			rdev_for_each(rdev, mddev)
3494				if (!test_bit(Journal, &rdev->flags) &&
3495				    !test_bit(In_sync, &rdev->flags)) {
3496					clear_bit(RT_FLAG_RS_IN_SYNC, &rs->runtime_flags);
3497					break;
3498				}
3499		}
3500	}
3501
3502	return min(r, resync_max_sectors);
3503}
3504
3505/* Helper to return @dev name or "-" if !@dev */
3506static const char *__get_dev_name(struct dm_dev *dev)
3507{
3508	return dev ? dev->name : "-";
3509}
3510
3511static void raid_status(struct dm_target *ti, status_type_t type,
3512			unsigned int status_flags, char *result, unsigned int maxlen)
3513{
3514	struct raid_set *rs = ti->private;
3515	struct mddev *mddev = &rs->md;
3516	struct r5conf *conf = mddev->private;
3517	int i, max_nr_stripes = conf ? conf->max_nr_stripes : 0;
3518	unsigned long recovery;
3519	unsigned int raid_param_cnt = 1; /* at least 1 for chunksize */
3520	unsigned int sz = 0;
3521	unsigned int rebuild_disks;
3522	unsigned int write_mostly_params = 0;
3523	sector_t progress, resync_max_sectors, resync_mismatches;
3524	const char *sync_action;
3525	struct raid_type *rt;
3526
3527	switch (type) {
3528	case STATUSTYPE_INFO:
3529		/* *Should* always succeed */
3530		rt = get_raid_type_by_ll(mddev->new_level, mddev->new_layout);
3531		if (!rt)
3532			return;
3533
3534		DMEMIT("%s %d ", rt->name, mddev->raid_disks);
3535
3536		/* Access most recent mddev properties for status output */
3537		smp_rmb();
3538		recovery = rs->md.recovery;
3539		/* Get sensible max sectors even if raid set not yet started */
3540		resync_max_sectors = test_bit(RT_FLAG_RS_PRERESUMED, &rs->runtime_flags) ?
3541				      mddev->resync_max_sectors : mddev->dev_sectors;
3542		progress = rs_get_progress(rs, recovery, resync_max_sectors);
 
 
3543		resync_mismatches = (mddev->last_sync_action && !strcasecmp(mddev->last_sync_action, "check")) ?
3544				    atomic64_read(&mddev->resync_mismatches) : 0;
3545		sync_action = decipher_sync_action(&rs->md, recovery);
3546
3547		/* HM FIXME: do we want another state char for raid0? It shows 'D'/'A'/'-' now */
3548		for (i = 0; i < rs->raid_disks; i++)
3549			DMEMIT(__raid_dev_status(rs, &rs->dev[i].rdev));
3550
3551		/*
3552		 * In-sync/Reshape ratio:
3553		 *  The in-sync ratio shows the progress of:
3554		 *   - Initializing the raid set
3555		 *   - Rebuilding a subset of devices of the raid set
3556		 *  The user can distinguish between the two by referring
3557		 *  to the status characters.
3558		 *
3559		 *  The reshape ratio shows the progress of
3560		 *  changing the raid layout or the number of
3561		 *  disks of a raid set
3562		 */
3563		DMEMIT(" %llu/%llu", (unsigned long long) progress,
3564				     (unsigned long long) resync_max_sectors);
3565
3566		/*
3567		 * v1.5.0+:
3568		 *
3569		 * Sync action:
3570		 *   See Documentation/device-mapper/dm-raid.txt for
3571		 *   information on each of these states.
3572		 */
3573		DMEMIT(" %s", sync_action);
3574
3575		/*
3576		 * v1.5.0+:
3577		 *
3578		 * resync_mismatches/mismatch_cnt
3579		 *   This field shows the number of discrepancies found when
3580		 *   performing a "check" of the raid set.
3581		 */
3582		DMEMIT(" %llu", (unsigned long long) resync_mismatches);
3583
3584		/*
3585		 * v1.9.0+:
3586		 *
3587		 * data_offset (needed for out of space reshaping)
3588		 *   This field shows the data offset into the data
3589		 *   image LV where the first stripes data starts.
3590		 *
3591		 * We keep data_offset equal on all raid disks of the set,
3592		 * so retrieving it from the first raid disk is sufficient.
3593		 */
3594		DMEMIT(" %llu", (unsigned long long) rs->dev[0].rdev.data_offset);
3595
3596		/*
3597		 * v1.10.0+:
3598		 */
3599		DMEMIT(" %s", test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags) ?
3600			      __raid_dev_status(rs, &rs->journal_dev.rdev) : "-");
3601		break;
3602
3603	case STATUSTYPE_TABLE:
3604		/* Report the table line string you would use to construct this raid set */
3605
3606		/* Calculate raid parameter count */
3607		for (i = 0; i < rs->raid_disks; i++)
3608			if (test_bit(WriteMostly, &rs->dev[i].rdev.flags))
3609				write_mostly_params += 2;
3610		rebuild_disks = memweight(rs->rebuild_disks, DISKS_ARRAY_ELEMS * sizeof(*rs->rebuild_disks));
3611		raid_param_cnt += rebuild_disks * 2 +
3612				  write_mostly_params +
 
 
 
 
 
3613				  hweight32(rs->ctr_flags & CTR_FLAG_OPTIONS_NO_ARGS) +
3614				  hweight32(rs->ctr_flags & CTR_FLAG_OPTIONS_ONE_ARG) * 2 +
3615				  (test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags) ? 2 : 0) +
3616				  (test_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags) ? 2 : 0);
3617
3618		/* Emit table line */
3619		/* This has to be in the documented order for userspace! */
3620		DMEMIT("%s %u %u", rs->raid_type->name, raid_param_cnt, mddev->new_chunk_sectors);
3621		if (test_bit(__CTR_FLAG_SYNC, &rs->ctr_flags))
3622			DMEMIT(" %s", dm_raid_arg_name_by_flag(CTR_FLAG_SYNC));
3623		if (test_bit(__CTR_FLAG_NOSYNC, &rs->ctr_flags))
3624			DMEMIT(" %s", dm_raid_arg_name_by_flag(CTR_FLAG_NOSYNC));
3625		if (rebuild_disks)
3626			for (i = 0; i < rs->raid_disks; i++)
3627				if (test_bit(rs->dev[i].rdev.raid_disk, (void *) rs->rebuild_disks))
3628					DMEMIT(" %s %u", dm_raid_arg_name_by_flag(CTR_FLAG_REBUILD),
3629							 rs->dev[i].rdev.raid_disk);
3630		if (test_bit(__CTR_FLAG_DAEMON_SLEEP, &rs->ctr_flags))
3631			DMEMIT(" %s %lu", dm_raid_arg_name_by_flag(CTR_FLAG_DAEMON_SLEEP),
3632					  mddev->bitmap_info.daemon_sleep);
3633		if (test_bit(__CTR_FLAG_MIN_RECOVERY_RATE, &rs->ctr_flags))
3634			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_MIN_RECOVERY_RATE),
3635					 mddev->sync_speed_min);
3636		if (test_bit(__CTR_FLAG_MAX_RECOVERY_RATE, &rs->ctr_flags))
3637			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_MAX_RECOVERY_RATE),
3638					 mddev->sync_speed_max);
3639		if (write_mostly_params)
3640			for (i = 0; i < rs->raid_disks; i++)
3641				if (test_bit(WriteMostly, &rs->dev[i].rdev.flags))
3642					DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_WRITE_MOSTLY),
3643					       rs->dev[i].rdev.raid_disk);
3644		if (test_bit(__CTR_FLAG_MAX_WRITE_BEHIND, &rs->ctr_flags))
3645			DMEMIT(" %s %lu", dm_raid_arg_name_by_flag(CTR_FLAG_MAX_WRITE_BEHIND),
3646					  mddev->bitmap_info.max_write_behind);
3647		if (test_bit(__CTR_FLAG_STRIPE_CACHE, &rs->ctr_flags))
3648			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_STRIPE_CACHE),
3649					 max_nr_stripes);
3650		if (test_bit(__CTR_FLAG_REGION_SIZE, &rs->ctr_flags))
3651			DMEMIT(" %s %llu", dm_raid_arg_name_by_flag(CTR_FLAG_REGION_SIZE),
3652					   (unsigned long long) to_sector(mddev->bitmap_info.chunksize));
3653		if (test_bit(__CTR_FLAG_RAID10_COPIES, &rs->ctr_flags))
3654			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_COPIES),
3655					 raid10_md_layout_to_copies(mddev->layout));
3656		if (test_bit(__CTR_FLAG_RAID10_FORMAT, &rs->ctr_flags))
3657			DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_RAID10_FORMAT),
3658					 raid10_md_layout_to_format(mddev->layout));
3659		if (test_bit(__CTR_FLAG_DELTA_DISKS, &rs->ctr_flags))
3660			DMEMIT(" %s %d", dm_raid_arg_name_by_flag(CTR_FLAG_DELTA_DISKS),
3661					 max(rs->delta_disks, mddev->delta_disks));
3662		if (test_bit(__CTR_FLAG_DATA_OFFSET, &rs->ctr_flags))
3663			DMEMIT(" %s %llu", dm_raid_arg_name_by_flag(CTR_FLAG_DATA_OFFSET),
3664					   (unsigned long long) rs->data_offset);
3665		if (test_bit(__CTR_FLAG_JOURNAL_DEV, &rs->ctr_flags))
3666			DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_DEV),
3667					__get_dev_name(rs->journal_dev.dev));
3668		if (test_bit(__CTR_FLAG_JOURNAL_MODE, &rs->ctr_flags))
3669			DMEMIT(" %s %s", dm_raid_arg_name_by_flag(CTR_FLAG_JOURNAL_MODE),
3670					 md_journal_mode_to_dm_raid(rs->journal_dev.mode));
3671		DMEMIT(" %d", rs->raid_disks);
3672		for (i = 0; i < rs->raid_disks; i++)
3673			DMEMIT(" %s %s", __get_dev_name(rs->dev[i].meta_dev),
3674					 __get_dev_name(rs->dev[i].data_dev));
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
3675	}
3676}
3677
3678static int raid_message(struct dm_target *ti, unsigned int argc, char **argv,
3679			char *result, unsigned maxlen)
3680{
3681	struct raid_set *rs = ti->private;
3682	struct mddev *mddev = &rs->md;
3683
3684	if (!mddev->pers || !mddev->pers->sync_request)
3685		return -EINVAL;
3686
3687	if (!strcasecmp(argv[0], "frozen"))
3688		set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3689	else
3690		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3691
3692	if (!strcasecmp(argv[0], "idle") || !strcasecmp(argv[0], "frozen")) {
3693		if (mddev->sync_thread) {
3694			set_bit(MD_RECOVERY_INTR, &mddev->recovery);
 
3695			md_reap_sync_thread(mddev);
3696		}
3697	} else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
3698		   test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
3699		return -EBUSY;
3700	else if (!strcasecmp(argv[0], "resync"))
3701		; /* MD_RECOVERY_NEEDED set below */
3702	else if (!strcasecmp(argv[0], "recover"))
3703		set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
3704	else {
3705		if (!strcasecmp(argv[0], "check")) {
3706			set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
3707			set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
3708			set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3709		} else if (!strcasecmp(argv[0], "repair")) {
3710			set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
3711			set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
3712		} else
3713			return -EINVAL;
3714	}
3715	if (mddev->ro == 2) {
3716		/* A write to sync_action is enough to justify
3717		 * canceling read-auto mode
3718		 */
3719		mddev->ro = 0;
3720		if (!mddev->suspended && mddev->sync_thread)
3721			md_wakeup_thread(mddev->sync_thread);
3722	}
3723	set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
3724	if (!mddev->suspended && mddev->thread)
3725		md_wakeup_thread(mddev->thread);
3726
3727	return 0;
3728}
3729
3730static int raid_iterate_devices(struct dm_target *ti,
3731				iterate_devices_callout_fn fn, void *data)
3732{
3733	struct raid_set *rs = ti->private;
3734	unsigned int i;
3735	int r = 0;
3736
3737	for (i = 0; !r && i < rs->md.raid_disks; i++)
3738		if (rs->dev[i].data_dev)
3739			r = fn(ti,
3740				 rs->dev[i].data_dev,
3741				 0, /* No offset on data devs */
3742				 rs->md.dev_sectors,
3743				 data);
3744
3745	return r;
3746}
3747
3748static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
3749{
3750	struct raid_set *rs = ti->private;
3751	unsigned int chunk_size = to_bytes(rs->md.chunk_sectors);
3752
3753	blk_limits_io_min(limits, chunk_size);
3754	blk_limits_io_opt(limits, chunk_size * mddev_data_stripes(rs));
3755}
3756
3757static void raid_postsuspend(struct dm_target *ti)
3758{
3759	struct raid_set *rs = ti->private;
3760
3761	if (!test_and_set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) {
3762		/* Writes have to be stopped before suspending to avoid deadlocks. */
3763		if (!test_bit(MD_RECOVERY_FROZEN, &rs->md.recovery))
3764			md_stop_writes(&rs->md);
3765
3766		mddev_lock_nointr(&rs->md);
3767		mddev_suspend(&rs->md);
3768		mddev_unlock(&rs->md);
3769	}
3770}
3771
3772static void attempt_restore_of_faulty_devices(struct raid_set *rs)
3773{
3774	int i;
3775	uint64_t cleared_failed_devices[DISKS_ARRAY_ELEMS];
3776	unsigned long flags;
3777	bool cleared = false;
3778	struct dm_raid_superblock *sb;
3779	struct mddev *mddev = &rs->md;
3780	struct md_rdev *r;
3781
3782	/* RAID personalities have to provide hot add/remove methods or we need to bail out. */
3783	if (!mddev->pers || !mddev->pers->hot_add_disk || !mddev->pers->hot_remove_disk)
3784		return;
3785
3786	memset(cleared_failed_devices, 0, sizeof(cleared_failed_devices));
3787
3788	for (i = 0; i < mddev->raid_disks; i++) {
3789		r = &rs->dev[i].rdev;
3790		/* HM FIXME: enhance journal device recovery processing */
3791		if (test_bit(Journal, &r->flags))
3792			continue;
3793
3794		if (test_bit(Faulty, &r->flags) &&
3795		    r->meta_bdev && !read_disk_sb(r, r->sb_size, true)) {
3796			DMINFO("Faulty %s device #%d has readable super block."
3797			       "  Attempting to revive it.",
3798			       rs->raid_type->name, i);
3799
3800			/*
3801			 * Faulty bit may be set, but sometimes the array can
3802			 * be suspended before the personalities can respond
3803			 * by removing the device from the array (i.e. calling
3804			 * 'hot_remove_disk').	If they haven't yet removed
3805			 * the failed device, its 'raid_disk' number will be
3806			 * '>= 0' - meaning we must call this function
3807			 * ourselves.
3808			 */
3809			flags = r->flags;
3810			clear_bit(In_sync, &r->flags); /* Mandatory for hot remove. */
3811			if (r->raid_disk >= 0) {
3812				if (mddev->pers->hot_remove_disk(mddev, r)) {
3813					/* Failed to revive this device, try next */
3814					r->flags = flags;
3815					continue;
3816				}
3817			} else
3818				r->raid_disk = r->saved_raid_disk = i;
3819
3820			clear_bit(Faulty, &r->flags);
3821			clear_bit(WriteErrorSeen, &r->flags);
3822
3823			if (mddev->pers->hot_add_disk(mddev, r)) {
3824				/* Failed to revive this device, try next */
3825				r->raid_disk = r->saved_raid_disk = -1;
3826				r->flags = flags;
3827			} else {
3828				clear_bit(In_sync, &r->flags);
3829				r->recovery_offset = 0;
3830				set_bit(i, (void *) cleared_failed_devices);
3831				cleared = true;
3832			}
3833		}
3834	}
3835
3836	/* If any failed devices could be cleared, update all sbs failed_devices bits */
3837	if (cleared) {
3838		uint64_t failed_devices[DISKS_ARRAY_ELEMS];
3839
3840		rdev_for_each(r, &rs->md) {
3841			if (test_bit(Journal, &r->flags))
3842				continue;
3843
3844			sb = page_address(r->sb_page);
3845			sb_retrieve_failed_devices(sb, failed_devices);
3846
3847			for (i = 0; i < DISKS_ARRAY_ELEMS; i++)
3848				failed_devices[i] &= ~cleared_failed_devices[i];
3849
3850			sb_update_failed_devices(sb, failed_devices);
3851		}
3852	}
3853}
3854
3855static int __load_dirty_region_bitmap(struct raid_set *rs)
3856{
3857	int r = 0;
3858
3859	/* Try loading the bitmap unless "raid0", which does not have one */
3860	if (!rs_is_raid0(rs) &&
3861	    !test_and_set_bit(RT_FLAG_RS_BITMAP_LOADED, &rs->runtime_flags)) {
3862		r = bitmap_load(&rs->md);
3863		if (r)
3864			DMERR("Failed to load bitmap");
3865	}
3866
3867	return r;
3868}
3869
3870/* Enforce updating all superblocks */
3871static void rs_update_sbs(struct raid_set *rs)
3872{
3873	struct mddev *mddev = &rs->md;
3874	int ro = mddev->ro;
3875
3876	set_bit(MD_SB_CHANGE_DEVS, &mddev->sb_flags);
3877	mddev->ro = 0;
3878	md_update_sb(mddev, 1);
3879	mddev->ro = ro;
3880}
3881
3882/*
3883 * Reshape changes raid algorithm of @rs to new one within personality
3884 * (e.g. raid6_zr -> raid6_nc), changes stripe size, adds/removes
3885 * disks from a raid set thus growing/shrinking it or resizes the set
3886 *
3887 * Call mddev_lock_nointr() before!
3888 */
3889static int rs_start_reshape(struct raid_set *rs)
3890{
3891	int r;
3892	struct mddev *mddev = &rs->md;
3893	struct md_personality *pers = mddev->pers;
3894
 
 
 
3895	r = rs_setup_reshape(rs);
3896	if (r)
3897		return r;
3898
3899	/* Need to be resumed to be able to start reshape, recovery is frozen until raid_resume() though */
3900	if (test_and_clear_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags))
3901		mddev_resume(mddev);
3902
3903	/*
3904	 * Check any reshape constraints enforced by the personalility
3905	 *
3906	 * May as well already kick the reshape off so that * pers->start_reshape() becomes optional.
3907	 */
3908	r = pers->check_reshape(mddev);
3909	if (r) {
3910		rs->ti->error = "pers->check_reshape() failed";
3911		return r;
3912	}
3913
3914	/*
3915	 * Personality may not provide start reshape method in which
3916	 * case check_reshape above has already covered everything
3917	 */
3918	if (pers->start_reshape) {
3919		r = pers->start_reshape(mddev);
3920		if (r) {
3921			rs->ti->error = "pers->start_reshape() failed";
3922			return r;
3923		}
3924	}
3925
3926	/* Suspend because a resume will happen in raid_resume() */
3927	set_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags);
3928	mddev_suspend(mddev);
3929
3930	/*
3931	 * Now reshape got set up, update superblocks to
3932	 * reflect the fact so that a table reload will
3933	 * access proper superblock content in the ctr.
3934	 */
3935	rs_update_sbs(rs);
3936
3937	return 0;
3938}
3939
3940static int raid_preresume(struct dm_target *ti)
3941{
3942	int r;
3943	struct raid_set *rs = ti->private;
3944	struct mddev *mddev = &rs->md;
3945
3946	/* This is a resume after a suspend of the set -> it's already started. */
3947	if (test_and_set_bit(RT_FLAG_RS_PRERESUMED, &rs->runtime_flags))
3948		return 0;
3949
3950	if (!test_bit(__CTR_FLAG_REBUILD, &rs->ctr_flags)) {
3951		struct raid_set *rs_active = rs_find_active(rs);
3952
3953		if (rs_active) {
3954			/*
3955			 * In case no rebuilds have been requested
3956			 * and an active table slot exists, copy
3957			 * current resynchonization completed and
3958			 * reshape position pointers across from
3959			 * suspended raid set in the active slot.
3960			 *
3961			 * This resumes the new mapping at current
3962			 * offsets to continue recover/reshape without
3963			 * necessarily redoing a raid set partially or
3964			 * causing data corruption in case of a reshape.
3965			 */
3966			if (rs_active->md.curr_resync_completed != MaxSector)
3967				mddev->curr_resync_completed = rs_active->md.curr_resync_completed;
3968			if (rs_active->md.reshape_position != MaxSector)
3969				mddev->reshape_position = rs_active->md.reshape_position;
3970		}
3971	}
3972
3973	/*
3974	 * The superblocks need to be updated on disk if the
3975	 * array is new or new devices got added (thus zeroed
3976	 * out by userspace) or __load_dirty_region_bitmap
3977	 * will overwrite them in core with old data or fail.
3978	 */
3979	if (test_bit(RT_FLAG_UPDATE_SBS, &rs->runtime_flags))
3980		rs_update_sbs(rs);
3981
3982	/* Load the bitmap from disk unless raid0 */
3983	r = __load_dirty_region_bitmap(rs);
3984	if (r)
3985		return r;
3986
3987	/* Resize bitmap to adjust to changed region size (aka MD bitmap chunksize) */
3988	if (test_bit(RT_FLAG_RS_BITMAP_LOADED, &rs->runtime_flags) && mddev->bitmap &&
3989	    mddev->bitmap_info.chunksize != to_bytes(rs->requested_bitmap_chunk_sectors)) {
3990		r = bitmap_resize(mddev->bitmap, mddev->dev_sectors,
3991				  to_bytes(rs->requested_bitmap_chunk_sectors), 0);
 
 
 
 
 
 
 
 
 
 
 
3992		if (r)
3993			DMERR("Failed to resize bitmap");
3994	}
3995
3996	/* Check for any resize/reshape on @rs and adjust/initiate */
3997	/* Be prepared for mddev_resume() in raid_resume() */
3998	set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
3999	if (mddev->recovery_cp && mddev->recovery_cp < MaxSector) {
4000		set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
4001		mddev->resync_min = mddev->recovery_cp;
 
 
4002	}
4003
4004	/* Check for any reshape request unless new raid set */
4005	if (test_bit(RT_FLAG_RESHAPE_RS, &rs->runtime_flags)) {
4006		/* Initiate a reshape. */
4007		rs_set_rdev_sectors(rs);
4008		mddev_lock_nointr(mddev);
4009		r = rs_start_reshape(rs);
4010		mddev_unlock(mddev);
4011		if (r)
4012			DMWARN("Failed to check/start reshape, continuing without change");
4013		r = 0;
4014	}
4015
4016	return r;
4017}
4018
4019static void raid_resume(struct dm_target *ti)
4020{
4021	struct raid_set *rs = ti->private;
4022	struct mddev *mddev = &rs->md;
4023
4024	if (test_and_set_bit(RT_FLAG_RS_RESUMED, &rs->runtime_flags)) {
4025		/*
4026		 * A secondary resume while the device is active.
4027		 * Take this opportunity to check whether any failed
4028		 * devices are reachable again.
4029		 */
4030		attempt_restore_of_faulty_devices(rs);
4031	}
4032
4033	if (test_and_clear_bit(RT_FLAG_RS_SUSPENDED, &rs->runtime_flags)) {
4034		/* Only reduce raid set size before running a disk removing reshape. */
4035		if (mddev->delta_disks < 0)
4036			rs_set_capacity(rs);
4037
4038		mddev_lock_nointr(mddev);
4039		clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
4040		mddev->ro = 0;
4041		mddev->in_sync = 0;
4042		mddev_resume(mddev);
4043		mddev_unlock(mddev);
4044	}
4045}
4046
4047static struct target_type raid_target = {
4048	.name = "raid",
4049	.version = {1, 13, 2},
4050	.module = THIS_MODULE,
4051	.ctr = raid_ctr,
4052	.dtr = raid_dtr,
4053	.map = raid_map,
4054	.status = raid_status,
4055	.message = raid_message,
4056	.iterate_devices = raid_iterate_devices,
4057	.io_hints = raid_io_hints,
4058	.postsuspend = raid_postsuspend,
4059	.preresume = raid_preresume,
4060	.resume = raid_resume,
4061};
4062
4063static int __init dm_raid_init(void)
4064{
4065	DMINFO("Loading target version %u.%u.%u",
4066	       raid_target.version[0],
4067	       raid_target.version[1],
4068	       raid_target.version[2]);
4069	return dm_register_target(&raid_target);
4070}
4071
4072static void __exit dm_raid_exit(void)
4073{
4074	dm_unregister_target(&raid_target);
4075}
4076
4077module_init(dm_raid_init);
4078module_exit(dm_raid_exit);
4079
4080module_param(devices_handle_discard_safely, bool, 0644);
4081MODULE_PARM_DESC(devices_handle_discard_safely,
4082		 "Set to Y if all devices in each array reliably return zeroes on reads from discarded regions");
4083
4084MODULE_DESCRIPTION(DM_NAME " raid0/1/10/4/5/6 target");
4085MODULE_ALIAS("dm-raid0");
4086MODULE_ALIAS("dm-raid1");
4087MODULE_ALIAS("dm-raid10");
4088MODULE_ALIAS("dm-raid4");
4089MODULE_ALIAS("dm-raid5");
4090MODULE_ALIAS("dm-raid6");
4091MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>");
4092MODULE_AUTHOR("Heinz Mauelshagen <dm-devel@redhat.com>");
4093MODULE_LICENSE("GPL");