dm-raid.c 38.4 KB
Newer Older
NeilBrown's avatar
NeilBrown committed
1
2
3
4
5
6
7
8
/*
 * Copyright (C) 2010-2011 Neil Brown
 * Copyright (C) 2010-2011 Red Hat, Inc. All rights reserved.
 *
 * This file is released under the GPL.
 */

#include <linux/slab.h>
9
#include <linux/module.h>
NeilBrown's avatar
NeilBrown committed
10
11

#include "md.h"
12
#include "raid1.h"
NeilBrown's avatar
NeilBrown committed
13
#include "raid5.h"
14
#include "raid10.h"
NeilBrown's avatar
NeilBrown committed
15
16
#include "bitmap.h"

Alasdair G Kergon's avatar
Alasdair G Kergon committed
17
18
#include <linux/device-mapper.h>

NeilBrown's avatar
NeilBrown committed
19
20
21
#define DM_MSG_PREFIX "raid"

/*
22
23
 * The following flags are used by dm-raid.c to set up the array state.
 * They must be cleared before md_run is called.
NeilBrown's avatar
NeilBrown committed
24
 */
25
#define FirstUse 10             /* rdev flag */
NeilBrown's avatar
NeilBrown committed
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41

struct raid_dev {
	/*
	 * Two DM devices, one to hold metadata and one to hold the
	 * actual data/parity.  The reason for this is to not confuse
	 * ti->len and give more flexibility in altering size and
	 * characteristics.
	 *
	 * While it is possible for this device to be associated
	 * with a different physical device than the data_dev, it
	 * is intended for it to be the same.
	 *    |--------- Physical Device ---------|
	 *    |- meta_dev -|------ data_dev ------|
	 */
	struct dm_dev *meta_dev;
	struct dm_dev *data_dev;
42
	struct md_rdev rdev;
NeilBrown's avatar
NeilBrown committed
43
44
45
46
47
};

/*
 * Flags for rs->print_flags field.
 */
48
49
50
51
52
53
54
55
#define DMPF_SYNC              0x1
#define DMPF_NOSYNC            0x2
#define DMPF_REBUILD           0x4
#define DMPF_DAEMON_SLEEP      0x8
#define DMPF_MIN_RECOVERY_RATE 0x10
#define DMPF_MAX_RECOVERY_RATE 0x20
#define DMPF_MAX_WRITE_BEHIND  0x40
#define DMPF_STRIPE_CACHE      0x80
56
57
58
59
#define DMPF_REGION_SIZE       0x100
#define DMPF_RAID10_COPIES     0x200
#define DMPF_RAID10_FORMAT     0x400

NeilBrown's avatar
NeilBrown committed
60
61
62
struct raid_set {
	struct dm_target *ti;

63
64
	uint32_t bitmap_loaded;
	uint32_t print_flags;
NeilBrown's avatar
NeilBrown committed
65

66
	struct mddev md;
NeilBrown's avatar
NeilBrown committed
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
	struct raid_type *raid_type;
	struct dm_target_callbacks callbacks;

	struct raid_dev dev[0];
};

/* Supported raid types and properties. */
static struct raid_type {
	const char *name;		/* RAID algorithm. */
	const char *descr;		/* Descriptor text for logging. */
	const unsigned parity_devs;	/* # of parity devices. */
	const unsigned minimal_devs;	/* minimal # of devices in set. */
	const unsigned level;		/* RAID level. */
	const unsigned algorithm;	/* RAID algorithm. */
} raid_types[] = {
82
	{"raid1",    "RAID1 (mirroring)",               0, 2, 1, 0 /* NONE */},
83
	{"raid10",   "RAID10 (striped mirrors)",        0, 2, 10, UINT_MAX /* Varies */},
NeilBrown's avatar
NeilBrown committed
84
85
86
87
88
89
90
91
92
93
	{"raid4",    "RAID4 (dedicated parity disk)",	1, 2, 5, ALGORITHM_PARITY_0},
	{"raid5_la", "RAID5 (left asymmetric)",		1, 2, 5, ALGORITHM_LEFT_ASYMMETRIC},
	{"raid5_ra", "RAID5 (right asymmetric)",	1, 2, 5, ALGORITHM_RIGHT_ASYMMETRIC},
	{"raid5_ls", "RAID5 (left symmetric)",		1, 2, 5, ALGORITHM_LEFT_SYMMETRIC},
	{"raid5_rs", "RAID5 (right symmetric)",		1, 2, 5, ALGORITHM_RIGHT_SYMMETRIC},
	{"raid6_zr", "RAID6 (zero restart)",		2, 4, 6, ALGORITHM_ROTATING_ZERO_RESTART},
	{"raid6_nr", "RAID6 (N restart)",		2, 4, 6, ALGORITHM_ROTATING_N_RESTART},
	{"raid6_nc", "RAID6 (N continue)",		2, 4, 6, ALGORITHM_ROTATING_N_CONTINUE}
};

94
95
96
97
98
99
100
101
102
103
104
static unsigned raid10_md_layout_to_copies(int layout)
{
	return layout & 0xFF;
}

static int raid10_format_to_md_layout(char *format, unsigned copies)
{
	/* 1 "far" copy, and 'copies' "near" copies */
	return (1 << 8) | (copies & 0xFF);
}

NeilBrown's avatar
NeilBrown committed
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
static struct raid_type *get_raid_type(char *name)
{
	int i;

	for (i = 0; i < ARRAY_SIZE(raid_types); i++)
		if (!strcmp(raid_types[i].name, name))
			return &raid_types[i];

	return NULL;
}

static struct raid_set *context_alloc(struct dm_target *ti, struct raid_type *raid_type, unsigned raid_devs)
{
	unsigned i;
	struct raid_set *rs;

	if (raid_devs <= raid_type->parity_devs) {
		ti->error = "Insufficient number of devices";
		return ERR_PTR(-EINVAL);
	}

	rs = kzalloc(sizeof(*rs) + raid_devs * sizeof(rs->dev[0]), GFP_KERNEL);
	if (!rs) {
		ti->error = "Cannot allocate raid context";
		return ERR_PTR(-ENOMEM);
	}

	mddev_init(&rs->md);

	rs->ti = ti;
	rs->raid_type = raid_type;
	rs->md.raid_disks = raid_devs;
	rs->md.level = raid_type->level;
	rs->md.new_level = rs->md.level;
	rs->md.layout = raid_type->algorithm;
	rs->md.new_layout = rs->md.layout;
	rs->md.delta_disks = 0;
	rs->md.recovery_cp = 0;

	for (i = 0; i < raid_devs; i++)
		md_rdev_init(&rs->dev[i].rdev);

	/*
	 * Remaining items to be initialized by further RAID params:
	 *  rs->md.persistent
	 *  rs->md.external
	 *  rs->md.chunk_sectors
	 *  rs->md.new_chunk_sectors
153
	 *  rs->md.dev_sectors
NeilBrown's avatar
NeilBrown committed
154
155
156
157
158
159
160
161
162
	 */

	return rs;
}

static void context_free(struct raid_set *rs)
{
	int i;

163
164
165
	for (i = 0; i < rs->md.raid_disks; i++) {
		if (rs->dev[i].meta_dev)
			dm_put_device(rs->ti, rs->dev[i].meta_dev);
166
		md_rdev_clear(&rs->dev[i].rdev);
NeilBrown's avatar
NeilBrown committed
167
168
		if (rs->dev[i].data_dev)
			dm_put_device(rs->ti, rs->dev[i].data_dev);
169
	}
NeilBrown's avatar
NeilBrown committed
170
171
172
173
174
175
176
177
178

	kfree(rs);
}

/*
 * For every device we have two words
 *  <meta_dev>: meta device name or '-' if missing
 *  <data_dev>: data device name or '-' if missing
 *
179
180
181
182
183
184
185
186
187
188
 * The following are permitted:
 *    - -
 *    - <data_dev>
 *    <meta_dev> <data_dev>
 *
 * The following is not allowed:
 *    <meta_dev> -
 *
 * This code parses those words.  If there is a failure,
 * the caller must use context_free to unwind the operations.
NeilBrown's avatar
NeilBrown committed
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
 */
static int dev_parms(struct raid_set *rs, char **argv)
{
	int i;
	int rebuild = 0;
	int metadata_available = 0;
	int ret = 0;

	for (i = 0; i < rs->md.raid_disks; i++, argv += 2) {
		rs->dev[i].rdev.raid_disk = i;

		rs->dev[i].meta_dev = NULL;
		rs->dev[i].data_dev = NULL;

		/*
		 * There are no offsets, since there is a separate device
		 * for data and metadata.
		 */
		rs->dev[i].rdev.data_offset = 0;
		rs->dev[i].rdev.mddev = &rs->md;

		if (strcmp(argv[0], "-")) {
211
212
213
214
215
216
217
218
219
220
			ret = dm_get_device(rs->ti, argv[0],
					    dm_table_get_mode(rs->ti->table),
					    &rs->dev[i].meta_dev);
			rs->ti->error = "RAID metadata device lookup failure";
			if (ret)
				return ret;

			rs->dev[i].rdev.sb_page = alloc_page(GFP_KERNEL);
			if (!rs->dev[i].rdev.sb_page)
				return -ENOMEM;
NeilBrown's avatar
NeilBrown committed
221
222
223
224
225
226
227
228
229
		}

		if (!strcmp(argv[1], "-")) {
			if (!test_bit(In_sync, &rs->dev[i].rdev.flags) &&
			    (!rs->dev[i].rdev.recovery_offset)) {
				rs->ti->error = "Drive designated for rebuild not specified";
				return -EINVAL;
			}

230
231
232
233
			rs->ti->error = "No data device supplied with metadata device";
			if (rs->dev[i].meta_dev)
				return -EINVAL;

NeilBrown's avatar
NeilBrown committed
234
235
236
237
238
239
240
241
242
243
244
			continue;
		}

		ret = dm_get_device(rs->ti, argv[1],
				    dm_table_get_mode(rs->ti->table),
				    &rs->dev[i].data_dev);
		if (ret) {
			rs->ti->error = "RAID device lookup failure";
			return ret;
		}

245
246
247
248
		if (rs->dev[i].meta_dev) {
			metadata_available = 1;
			rs->dev[i].rdev.meta_bdev = rs->dev[i].meta_dev->bdev;
		}
NeilBrown's avatar
NeilBrown committed
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
		rs->dev[i].rdev.bdev = rs->dev[i].data_dev->bdev;
		list_add(&rs->dev[i].rdev.same_set, &rs->md.disks);
		if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
			rebuild++;
	}

	if (metadata_available) {
		rs->md.external = 0;
		rs->md.persistent = 1;
		rs->md.major_version = 2;
	} else if (rebuild && !rs->md.recovery_cp) {
		/*
		 * Without metadata, we will not be able to tell if the array
		 * is in-sync or not - we must assume it is not.  Therefore,
		 * it is impossible to rebuild a drive.
		 *
		 * Even if there is metadata, the on-disk information may
		 * indicate that the array is not in-sync and it will then
		 * fail at that time.
		 *
		 * User could specify 'nosync' option if desperate.
		 */
		DMERR("Unable to rebuild drive while array is not in-sync");
		rs->ti->error = "RAID device lookup failure";
		return -EINVAL;
	}

	return 0;
}

279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
/*
 * validate_region_size
 * @rs
 * @region_size:  region size in sectors.  If 0, pick a size (4MiB default).
 *
 * Set rs->md.bitmap_info.chunksize (which really refers to 'region size').
 * Ensure that (ti->len/region_size < 2^21) - required by MD bitmap.
 *
 * Returns: 0 on success, -EINVAL on failure.
 */
static int validate_region_size(struct raid_set *rs, unsigned long region_size)
{
	unsigned long min_region_size = rs->ti->len / (1 << 21);

	if (!region_size) {
		/*
		 * Choose a reasonable default.  All figures in sectors.
		 */
		if (min_region_size > (1 << 13)) {
298
299
300
			/* If not a power of 2, make it the next power of 2 */
			if (min_region_size & (min_region_size - 1))
				region_size = 1 << fls(region_size);
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
			DMINFO("Choosing default region size of %lu sectors",
			       region_size);
		} else {
			DMINFO("Choosing default region size of 4MiB");
			region_size = 1 << 13; /* sectors */
		}
	} else {
		/*
		 * Validate user-supplied value.
		 */
		if (region_size > rs->ti->len) {
			rs->ti->error = "Supplied region size is too large";
			return -EINVAL;
		}

		if (region_size < min_region_size) {
			DMERR("Supplied region_size (%lu sectors) below minimum (%lu)",
			      region_size, min_region_size);
			rs->ti->error = "Supplied region size is too small";
			return -EINVAL;
		}

		if (!is_power_of_2(region_size)) {
			rs->ti->error = "Region size is not a power of 2";
			return -EINVAL;
		}

		if (region_size < rs->md.chunk_sectors) {
			rs->ti->error = "Region size is smaller than the chunk size";
			return -EINVAL;
		}
	}

	/*
	 * Convert sectors to bytes.
	 */
	rs->md.bitmap_info.chunksize = (region_size << 9);

	return 0;
}

342
343
344
345
346
347
348
349
350
351
352
353
/*
 * validate_rebuild_devices
 * @rs
 *
 * Determine if the devices specified for rebuild can result in a valid
 * usable array that is capable of rebuilding the given devices.
 *
 * Returns: 0 on success, -EINVAL on failure.
 */
static int validate_rebuild_devices(struct raid_set *rs)
{
	unsigned i, rebuild_cnt = 0;
354
	unsigned rebuilds_per_group, copies, d;
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374

	if (!(rs->print_flags & DMPF_REBUILD))
		return 0;

	for (i = 0; i < rs->md.raid_disks; i++)
		if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
			rebuild_cnt++;

	switch (rs->raid_type->level) {
	case 1:
		if (rebuild_cnt >= rs->md.raid_disks)
			goto too_many;
		break;
	case 4:
	case 5:
	case 6:
		if (rebuild_cnt > rs->raid_type->parity_devs)
			goto too_many;
		break;
	case 10:
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
		copies = raid10_md_layout_to_copies(rs->md.layout);
		if (rebuild_cnt < copies)
			break;

		/*
		 * It is possible to have a higher rebuild count for RAID10,
		 * as long as the failed devices occur in different mirror
		 * groups (i.e. different stripes).
		 *
		 * Right now, we only allow for "near" copies.  When other
		 * formats are added, we will have to check those too.
		 *
		 * When checking "near" format, make sure no adjacent devices
		 * have failed beyond what can be handled.  In addition to the
		 * simple case where the number of devices is a multiple of the
		 * number of copies, we must also handle cases where the number
		 * of devices is not a multiple of the number of copies.
		 * E.g.    dev1 dev2 dev3 dev4 dev5
		 *          A    A    B    B    C
		 *          C    D    D    E    E
		 */
		rebuilds_per_group = 0;
		for (i = 0; i < rs->md.raid_disks * copies; i++) {
			d = i % rs->md.raid_disks;
			if (!test_bit(In_sync, &rs->dev[d].rdev.flags) &&
			    (++rebuilds_per_group >= copies))
				goto too_many;
			if (!((i + 1) % copies))
				rebuilds_per_group = 0;
		}
		break;
406
407
408
409
410
411
412
413
414
415
416
417
418
419
	default:
		DMERR("The rebuild parameter is not supported for %s",
		      rs->raid_type->name);
		rs->ti->error = "Rebuild not supported for this RAID type";
		return -EINVAL;
	}

	return 0;

too_many:
	rs->ti->error = "Too many rebuild devices specified";
	return -EINVAL;
}

NeilBrown's avatar
NeilBrown committed
420
421
422
423
/*
 * Possible arguments are...
 *	<chunk_size> [optional_args]
 *
424
425
426
427
428
 * Argument definitions
 *    <chunk_size>			The number of sectors per disk that
 *                                      will form the "stripe"
 *    [[no]sync]			Force or prevent recovery of the
 *                                      entire array
NeilBrown's avatar
NeilBrown committed
429
 *    [rebuild <idx>]			Rebuild the drive indicated by the index
430
431
 *    [daemon_sleep <ms>]		Time between bitmap daemon work to
 *                                      clear bits
NeilBrown's avatar
NeilBrown committed
432
433
 *    [min_recovery_rate <kB/sec/disk>]	Throttle RAID initialization
 *    [max_recovery_rate <kB/sec/disk>]	Throttle RAID initialization
434
 *    [write_mostly <idx>]		Indicate a write mostly drive via index
NeilBrown's avatar
NeilBrown committed
435
436
 *    [max_write_behind <sectors>]	See '-write-behind=' (man mdadm)
 *    [stripe_cache <sectors>]		Stripe cache size for higher RAIDs
437
 *    [region_size <sectors>]           Defines granularity of bitmap
438
439
440
441
 *
 * RAID10-only options:
 *    [raid10_copies <# copies>]        Number of copies.  (Default: 2)
 *    [raid10_format <near>]            Layout algorithm.  (Default: near)
NeilBrown's avatar
NeilBrown committed
442
443
444
445
 */
static int parse_raid_params(struct raid_set *rs, char **argv,
			     unsigned num_raid_params)
{
446
447
	char *raid10_format = "near";
	unsigned raid10_copies = 2;
448
	unsigned i;
449
	unsigned long value, region_size = 0;
450
	sector_t sectors_per_dev = rs->ti->len;
451
	sector_t max_io_len;
NeilBrown's avatar
NeilBrown committed
452
453
454
455
	char *key;

	/*
	 * First, parse the in-order required arguments
456
	 * "chunk_size" is the only argument of this type.
NeilBrown's avatar
NeilBrown committed
457
	 */
458
	if ((strict_strtoul(argv[0], 10, &value) < 0)) {
NeilBrown's avatar
NeilBrown committed
459
460
		rs->ti->error = "Bad chunk size";
		return -EINVAL;
461
462
463
464
465
466
467
468
469
470
	} else if (rs->raid_type->level == 1) {
		if (value)
			DMERR("Ignoring chunk size parameter for RAID 1");
		value = 0;
	} else if (!is_power_of_2(value)) {
		rs->ti->error = "Chunk size must be a power of 2";
		return -EINVAL;
	} else if (value < 8) {
		rs->ti->error = "Chunk size value is too small";
		return -EINVAL;
NeilBrown's avatar
NeilBrown committed
471
472
473
474
475
476
477
	}

	rs->md.new_chunk_sectors = rs->md.chunk_sectors = value;
	argv++;
	num_raid_params--;

	/*
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
	 * We set each individual device as In_sync with a completed
	 * 'recovery_offset'.  If there has been a device failure or
	 * replacement then one of the following cases applies:
	 *
	 *   1) User specifies 'rebuild'.
	 *      - Device is reset when param is read.
	 *   2) A new device is supplied.
	 *      - No matching superblock found, resets device.
	 *   3) Device failure was transient and returns on reload.
	 *      - Failure noticed, resets device for bitmap replay.
	 *   4) Device hadn't completed recovery after previous failure.
	 *      - Superblock is read and overrides recovery_offset.
	 *
	 * What is found in the superblocks of the devices is always
	 * authoritative, unless 'rebuild' or '[no]sync' was specified.
NeilBrown's avatar
NeilBrown committed
493
	 */
494
	for (i = 0; i < rs->md.raid_disks; i++) {
NeilBrown's avatar
NeilBrown committed
495
		set_bit(In_sync, &rs->dev[i].rdev.flags);
496
497
		rs->dev[i].rdev.recovery_offset = MaxSector;
	}
NeilBrown's avatar
NeilBrown committed
498

499
500
501
	/*
	 * Second, parse the unordered optional arguments
	 */
NeilBrown's avatar
NeilBrown committed
502
	for (i = 0; i < num_raid_params; i++) {
503
		if (!strcasecmp(argv[i], "nosync")) {
NeilBrown's avatar
NeilBrown committed
504
505
506
507
			rs->md.recovery_cp = MaxSector;
			rs->print_flags |= DMPF_NOSYNC;
			continue;
		}
508
		if (!strcasecmp(argv[i], "sync")) {
NeilBrown's avatar
NeilBrown committed
509
510
511
512
513
514
515
516
517
518
519
520
			rs->md.recovery_cp = 0;
			rs->print_flags |= DMPF_SYNC;
			continue;
		}

		/* The rest of the optional arguments come in key/value pairs */
		if ((i + 1) >= num_raid_params) {
			rs->ti->error = "Wrong number of raid parameters given";
			return -EINVAL;
		}

		key = argv[i++];
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536

		/* Parameters that take a string value are checked here. */
		if (!strcasecmp(key, "raid10_format")) {
			if (rs->raid_type->level != 10) {
				rs->ti->error = "'raid10_format' is an invalid parameter for this RAID type";
				return -EINVAL;
			}
			if (strcmp("near", argv[i])) {
				rs->ti->error = "Invalid 'raid10_format' value given";
				return -EINVAL;
			}
			raid10_format = argv[i];
			rs->print_flags |= DMPF_RAID10_FORMAT;
			continue;
		}

NeilBrown's avatar
NeilBrown committed
537
538
539
540
541
		if (strict_strtoul(argv[i], 10, &value) < 0) {
			rs->ti->error = "Bad numerical argument given in raid params";
			return -EINVAL;
		}

542
		/* Parameters that take a numeric value are checked here */
543
		if (!strcasecmp(key, "rebuild")) {
544
			if (value >= rs->md.raid_disks) {
NeilBrown's avatar
NeilBrown committed
545
546
547
548
549
				rs->ti->error = "Invalid rebuild index given";
				return -EINVAL;
			}
			clear_bit(In_sync, &rs->dev[value].rdev.flags);
			rs->dev[value].rdev.recovery_offset = 0;
550
			rs->print_flags |= DMPF_REBUILD;
551
552
553
554
555
		} else if (!strcasecmp(key, "write_mostly")) {
			if (rs->raid_type->level != 1) {
				rs->ti->error = "write_mostly option is only valid for RAID1";
				return -EINVAL;
			}
556
			if (value >= rs->md.raid_disks) {
557
558
559
560
				rs->ti->error = "Invalid write_mostly drive index given";
				return -EINVAL;
			}
			set_bit(WriteMostly, &rs->dev[value].rdev.flags);
561
		} else if (!strcasecmp(key, "max_write_behind")) {
562
563
564
565
			if (rs->raid_type->level != 1) {
				rs->ti->error = "max_write_behind option is only valid for RAID1";
				return -EINVAL;
			}
NeilBrown's avatar
NeilBrown committed
566
567
568
569
570
571
572
573
574
575
576
577
			rs->print_flags |= DMPF_MAX_WRITE_BEHIND;

			/*
			 * In device-mapper, we specify things in sectors, but
			 * MD records this value in kB
			 */
			value /= 2;
			if (value > COUNTER_MAX) {
				rs->ti->error = "Max write-behind limit out of range";
				return -EINVAL;
			}
			rs->md.bitmap_info.max_write_behind = value;
578
		} else if (!strcasecmp(key, "daemon_sleep")) {
NeilBrown's avatar
NeilBrown committed
579
580
581
582
583
584
			rs->print_flags |= DMPF_DAEMON_SLEEP;
			if (!value || (value > MAX_SCHEDULE_TIMEOUT)) {
				rs->ti->error = "daemon sleep period out of range";
				return -EINVAL;
			}
			rs->md.bitmap_info.daemon_sleep = value;
585
		} else if (!strcasecmp(key, "stripe_cache")) {
NeilBrown's avatar
NeilBrown committed
586
587
588
589
590
591
592
593
			rs->print_flags |= DMPF_STRIPE_CACHE;

			/*
			 * In device-mapper, we specify things in sectors, but
			 * MD records this value in kB
			 */
			value /= 2;

594
595
			if ((rs->raid_type->level != 5) &&
			    (rs->raid_type->level != 6)) {
NeilBrown's avatar
NeilBrown committed
596
597
598
599
600
601
602
				rs->ti->error = "Inappropriate argument: stripe_cache";
				return -EINVAL;
			}
			if (raid5_set_cache_size(&rs->md, (int)value)) {
				rs->ti->error = "Bad stripe_cache size";
				return -EINVAL;
			}
603
		} else if (!strcasecmp(key, "min_recovery_rate")) {
NeilBrown's avatar
NeilBrown committed
604
605
606
607
608
609
			rs->print_flags |= DMPF_MIN_RECOVERY_RATE;
			if (value > INT_MAX) {
				rs->ti->error = "min_recovery_rate out of range";
				return -EINVAL;
			}
			rs->md.sync_speed_min = (int)value;
610
		} else if (!strcasecmp(key, "max_recovery_rate")) {
NeilBrown's avatar
NeilBrown committed
611
612
613
614
615
616
			rs->print_flags |= DMPF_MAX_RECOVERY_RATE;
			if (value > INT_MAX) {
				rs->ti->error = "max_recovery_rate out of range";
				return -EINVAL;
			}
			rs->md.sync_speed_max = (int)value;
617
618
619
		} else if (!strcasecmp(key, "region_size")) {
			rs->print_flags |= DMPF_REGION_SIZE;
			region_size = value;
620
621
622
623
624
625
626
627
		} else if (!strcasecmp(key, "raid10_copies") &&
			   (rs->raid_type->level == 10)) {
			if ((value < 2) || (value > 0xFF)) {
				rs->ti->error = "Bad value for 'raid10_copies'";
				return -EINVAL;
			}
			rs->print_flags |= DMPF_RAID10_COPIES;
			raid10_copies = value;
NeilBrown's avatar
NeilBrown committed
628
629
630
631
632
633
634
		} else {
			DMERR("Unable to parse RAID parameter: %s", key);
			rs->ti->error = "Unable to parse RAID parameters";
			return -EINVAL;
		}
	}

635
636
637
638
	if (validate_region_size(rs, region_size))
		return -EINVAL;

	if (rs->md.chunk_sectors)
639
		max_io_len = rs->md.chunk_sectors;
640
	else
641
		max_io_len = region_size;
642

643
644
	if (dm_set_target_max_io_len(rs->ti, max_io_len))
		return -EINVAL;
645

646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
	if (rs->raid_type->level == 10) {
		if (raid10_copies > rs->md.raid_disks) {
			rs->ti->error = "Not enough devices to satisfy specification";
			return -EINVAL;
		}

		/* (Len * #mirrors) / #devices */
		sectors_per_dev = rs->ti->len * raid10_copies;
		sector_div(sectors_per_dev, rs->md.raid_disks);

		rs->md.layout = raid10_format_to_md_layout(raid10_format,
							   raid10_copies);
		rs->md.new_layout = rs->md.layout;
	} else if ((rs->raid_type->level > 1) &&
		   sector_div(sectors_per_dev,
			      (rs->md.raid_disks - rs->raid_type->parity_devs))) {
662
663
664
665
666
		rs->ti->error = "Target length not divisible by number of data devices";
		return -EINVAL;
	}
	rs->md.dev_sectors = sectors_per_dev;

667
668
669
	if (validate_rebuild_devices(rs))
		return -EINVAL;

NeilBrown's avatar
NeilBrown committed
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
	/* Assume there are no metadata devices until the drives are parsed */
	rs->md.persistent = 0;
	rs->md.external = 1;

	return 0;
}

static void do_table_event(struct work_struct *ws)
{
	struct raid_set *rs = container_of(ws, struct raid_set, md.event_work);

	dm_table_event(rs->ti->table);
}

static int raid_is_congested(struct dm_target_callbacks *cb, int bits)
{
	struct raid_set *rs = container_of(cb, struct raid_set, callbacks);

688
689
690
	if (rs->raid_type->level == 1)
		return md_raid1_congested(&rs->md, bits);

691
692
693
	if (rs->raid_type->level == 10)
		return md_raid10_congested(&rs->md, bits);

NeilBrown's avatar
NeilBrown committed
694
695
696
	return md_raid5_congested(&rs->md, bits);
}

697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
/*
 * This structure is never routinely used by userspace, unlike md superblocks.
 * Devices with this superblock should only ever be accessed via device-mapper.
 */
#define DM_RAID_MAGIC 0x64526D44
struct dm_raid_superblock {
	__le32 magic;		/* "DmRd" */
	__le32 features;	/* Used to indicate possible future changes */

	__le32 num_devices;	/* Number of devices in this array. (Max 64) */
	__le32 array_position;	/* The position of this drive in the array */

	__le64 events;		/* Incremented by md when superblock updated */
	__le64 failed_devices;	/* Bit field of devices to indicate failures */

	/*
	 * This offset tracks the progress of the repair or replacement of
	 * an individual drive.
	 */
	__le64 disk_recovery_offset;

	/*
	 * This offset tracks the progress of the initial array
	 * synchronisation/parity calculation.
	 */
	__le64 array_resync_offset;

	/*
	 * RAID characteristics
	 */
	__le32 level;
	__le32 layout;
	__le32 stripe_sectors;

	__u8 pad[452];		/* Round struct to 512 bytes. */
				/* Always set to 0 when writing. */
} __packed;

735
static int read_disk_sb(struct md_rdev *rdev, int size)
736
737
738
739
740
741
742
{
	BUG_ON(!rdev->sb_page);

	if (rdev->sb_loaded)
		return 0;

	if (!sync_page_io(rdev, 0, size, rdev->sb_page, READ, 1)) {
743
744
		DMERR("Failed to read superblock of device at position %d",
		      rdev->raid_disk);
745
		md_error(rdev->mddev, rdev);
746
747
748
749
750
751
752
753
		return -EINVAL;
	}

	rdev->sb_loaded = 1;

	return 0;
}

754
static void super_sync(struct mddev *mddev, struct md_rdev *rdev)
755
{
756
	int i;
757
758
	uint64_t failed_devices;
	struct dm_raid_superblock *sb;
759
	struct raid_set *rs = container_of(mddev, struct raid_set, md);
760
761
762
763

	sb = page_address(rdev->sb_page);
	failed_devices = le64_to_cpu(sb->failed_devices);

764
765
766
767
	for (i = 0; i < mddev->raid_disks; i++)
		if (!rs->dev[i].data_dev ||
		    test_bit(Faulty, &(rs->dev[i].rdev.flags)))
			failed_devices |= (1ULL << i);
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795

	memset(sb, 0, sizeof(*sb));

	sb->magic = cpu_to_le32(DM_RAID_MAGIC);
	sb->features = cpu_to_le32(0);	/* No features yet */

	sb->num_devices = cpu_to_le32(mddev->raid_disks);
	sb->array_position = cpu_to_le32(rdev->raid_disk);

	sb->events = cpu_to_le64(mddev->events);
	sb->failed_devices = cpu_to_le64(failed_devices);

	sb->disk_recovery_offset = cpu_to_le64(rdev->recovery_offset);
	sb->array_resync_offset = cpu_to_le64(mddev->recovery_cp);

	sb->level = cpu_to_le32(mddev->level);
	sb->layout = cpu_to_le32(mddev->layout);
	sb->stripe_sectors = cpu_to_le32(mddev->chunk_sectors);
}

/*
 * super_load
 *
 * This function creates a superblock if one is not found on the device
 * and will decide which superblock to use if there's a choice.
 *
 * Return: 1 if use rdev, 0 if use refdev, -Exxx otherwise
 */
796
static int super_load(struct md_rdev *rdev, struct md_rdev *refdev)
797
798
799
800
801
802
803
804
805
806
807
808
809
810
{
	int ret;
	struct dm_raid_superblock *sb;
	struct dm_raid_superblock *refsb;
	uint64_t events_sb, events_refsb;

	rdev->sb_start = 0;
	rdev->sb_size = sizeof(*sb);

	ret = read_disk_sb(rdev, rdev->sb_size);
	if (ret)
		return ret;

	sb = page_address(rdev->sb_page);
811
812
813
814
815
816
817
818

	/*
	 * Two cases that we want to write new superblocks and rebuild:
	 * 1) New device (no matching magic number)
	 * 2) Device specified for rebuild (!In_sync w/ offset == 0)
	 */
	if ((sb->magic != cpu_to_le32(DM_RAID_MAGIC)) ||
	    (!test_bit(In_sync, &rdev->flags) && !rdev->recovery_offset)) {
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
		super_sync(rdev->mddev, rdev);

		set_bit(FirstUse, &rdev->flags);

		/* Force writing of superblocks to disk */
		set_bit(MD_CHANGE_DEVS, &rdev->mddev->flags);

		/* Any superblock is better than none, choose that if given */
		return refdev ? 0 : 1;
	}

	if (!refdev)
		return 1;

	events_sb = le64_to_cpu(sb->events);

	refsb = page_address(refdev->sb_page);
	events_refsb = le64_to_cpu(refsb->events);

	return (events_sb > events_refsb) ? 1 : 0;
}

841
static int super_init_validation(struct mddev *mddev, struct md_rdev *rdev)
842
843
844
845
846
847
848
849
{
	int role;
	struct raid_set *rs = container_of(mddev, struct raid_set, md);
	uint64_t events_sb;
	uint64_t failed_devices;
	struct dm_raid_superblock *sb;
	uint32_t new_devs = 0;
	uint32_t rebuilds = 0;
NeilBrown's avatar
NeilBrown committed
850
	struct md_rdev *r;
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
	struct dm_raid_superblock *sb2;

	sb = page_address(rdev->sb_page);
	events_sb = le64_to_cpu(sb->events);
	failed_devices = le64_to_cpu(sb->failed_devices);

	/*
	 * Initialise to 1 if this is a new superblock.
	 */
	mddev->events = events_sb ? : 1;

	/*
	 * Reshaping is not currently allowed
	 */
	if ((le32_to_cpu(sb->level) != mddev->level) ||
	    (le32_to_cpu(sb->layout) != mddev->layout) ||
	    (le32_to_cpu(sb->stripe_sectors) != mddev->chunk_sectors)) {
		DMERR("Reshaping arrays not yet supported.");
		return -EINVAL;
	}

	/* We can only change the number of devices in RAID1 right now */
	if ((rs->raid_type->level != 1) &&
	    (le32_to_cpu(sb->num_devices) != mddev->raid_disks)) {
		DMERR("Reshaping arrays not yet supported.");
		return -EINVAL;
	}

	if (!(rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC)))
		mddev->recovery_cp = le64_to_cpu(sb->array_resync_offset);

	/*
	 * During load, we set FirstUse if a new superblock was written.
	 * There are two reasons we might not have a superblock:
	 * 1) The array is brand new - in which case, all of the
	 *    devices must have their In_sync bit set.  Also,
	 *    recovery_cp must be 0, unless forced.
	 * 2) This is a new device being added to an old array
	 *    and the new device needs to be rebuilt - in which
	 *    case the In_sync bit will /not/ be set and
	 *    recovery_cp must be MaxSector.
	 */
NeilBrown's avatar
NeilBrown committed
893
	rdev_for_each(r, mddev) {
894
		if (!test_bit(In_sync, &r->flags)) {
895
896
			DMINFO("Device %d specified for rebuild: "
			       "Clearing superblock", r->raid_disk);
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
			rebuilds++;
		} else if (test_bit(FirstUse, &r->flags))
			new_devs++;
	}

	if (!rebuilds) {
		if (new_devs == mddev->raid_disks) {
			DMINFO("Superblocks created for new array");
			set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
		} else if (new_devs) {
			DMERR("New device injected "
			      "into existing array without 'rebuild' "
			      "parameter specified");
			return -EINVAL;
		}
	} else if (new_devs) {
		DMERR("'rebuild' devices cannot be "
		      "injected into an array with other first-time devices");
		return -EINVAL;
	} else if (mddev->recovery_cp != MaxSector) {
		DMERR("'rebuild' specified while array is not in-sync");
		return -EINVAL;
	}

	/*
	 * Now we set the Faulty bit for those devices that are
	 * recorded in the superblock as failed.
	 */
NeilBrown's avatar
NeilBrown committed
925
	rdev_for_each(r, mddev) {
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
		if (!r->sb_page)
			continue;
		sb2 = page_address(r->sb_page);
		sb2->failed_devices = 0;

		/*
		 * Check for any device re-ordering.
		 */
		if (!test_bit(FirstUse, &r->flags) && (r->raid_disk >= 0)) {
			role = le32_to_cpu(sb2->array_position);
			if (role != r->raid_disk) {
				if (rs->raid_type->level != 1) {
					rs->ti->error = "Cannot change device "
						"positions in RAID array";
					return -EINVAL;
				}
				DMINFO("RAID1 device #%d now at position #%d",
				       role, r->raid_disk);
			}

			/*
			 * Partial recovery is performed on
			 * returning failed devices.
			 */
			if (failed_devices & (1 << role))
				set_bit(Faulty, &r->flags);
		}
	}

	return 0;
}

958
static int super_validate(struct mddev *mddev, struct md_rdev *rdev)
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
{
	struct dm_raid_superblock *sb = page_address(rdev->sb_page);

	/*
	 * If mddev->events is not set, we know we have not yet initialized
	 * the array.
	 */
	if (!mddev->events && super_init_validation(mddev, rdev))
		return -EINVAL;

	mddev->bitmap_info.offset = 4096 >> 9; /* Enable bitmap creation */
	rdev->mddev->bitmap_info.default_offset = 4096 >> 9;
	if (!test_bit(FirstUse, &rdev->flags)) {
		rdev->recovery_offset = le64_to_cpu(sb->disk_recovery_offset);
		if (rdev->recovery_offset != MaxSector)
			clear_bit(In_sync, &rdev->flags);
	}

	/*
	 * If a device comes back, set it as not In_sync and no longer faulty.
	 */
	if (test_bit(Faulty, &rdev->flags)) {
		clear_bit(Faulty, &rdev->flags);
		clear_bit(In_sync, &rdev->flags);
		rdev->saved_raid_disk = rdev->raid_disk;
		rdev->recovery_offset = 0;
	}

	clear_bit(FirstUse, &rdev->flags);

	return 0;
}

/*
 * Analyse superblocks and select the freshest.
 */
static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
{
	int ret;
998
999
	unsigned redundancy = 0;
	struct raid_dev *dev;
1000
	struct md_rdev *rdev, *tmp, *freshest;
For faster browsing, not all history is shown. View entire blame