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1/*
2 * Copyright (C) 2010-2011 Neil Brown
3 * Copyright (C) 2010-2011 Red Hat, Inc. All rights reserved.
4 *
5 * This file is released under the GPL.
6 */
7
8#include <linux/slab.h>
9
10#include "md.h"
11#include "raid1.h"
12#include "raid5.h"
13#include "bitmap.h"
14
15#include <linux/device-mapper.h>
16
17#define DM_MSG_PREFIX "raid"
18
19/*
20 * The following flags are used by dm-raid.c to set up the array state.
21 * They must be cleared before md_run is called.
22 */
23#define FirstUse 10 /* rdev flag */
24
25struct raid_dev {
26 /*
27 * Two DM devices, one to hold metadata and one to hold the
28 * actual data/parity. The reason for this is to not confuse
29 * ti->len and give more flexibility in altering size and
30 * characteristics.
31 *
32 * While it is possible for this device to be associated
33 * with a different physical device than the data_dev, it
34 * is intended for it to be the same.
35 * |--------- Physical Device ---------|
36 * |- meta_dev -|------ data_dev ------|
37 */
38 struct dm_dev *meta_dev;
39 struct dm_dev *data_dev;
40 struct mdk_rdev_s rdev;
41};
42
43/*
44 * Flags for rs->print_flags field.
45 */
46#define DMPF_SYNC 0x1
47#define DMPF_NOSYNC 0x2
48#define DMPF_REBUILD 0x4
49#define DMPF_DAEMON_SLEEP 0x8
50#define DMPF_MIN_RECOVERY_RATE 0x10
51#define DMPF_MAX_RECOVERY_RATE 0x20
52#define DMPF_MAX_WRITE_BEHIND 0x40
53#define DMPF_STRIPE_CACHE 0x80
54#define DMPF_REGION_SIZE 0X100
55struct raid_set {
56 struct dm_target *ti;
57
58 uint64_t print_flags;
59
60 struct mddev_s md;
61 struct raid_type *raid_type;
62 struct dm_target_callbacks callbacks;
63
64 struct raid_dev dev[0];
65};
66
67/* Supported raid types and properties. */
68static struct raid_type {
69 const char *name; /* RAID algorithm. */
70 const char *descr; /* Descriptor text for logging. */
71 const unsigned parity_devs; /* # of parity devices. */
72 const unsigned minimal_devs; /* minimal # of devices in set. */
73 const unsigned level; /* RAID level. */
74 const unsigned algorithm; /* RAID algorithm. */
75} raid_types[] = {
76 {"raid1", "RAID1 (mirroring)", 0, 2, 1, 0 /* NONE */},
77 {"raid4", "RAID4 (dedicated parity disk)", 1, 2, 5, ALGORITHM_PARITY_0},
78 {"raid5_la", "RAID5 (left asymmetric)", 1, 2, 5, ALGORITHM_LEFT_ASYMMETRIC},
79 {"raid5_ra", "RAID5 (right asymmetric)", 1, 2, 5, ALGORITHM_RIGHT_ASYMMETRIC},
80 {"raid5_ls", "RAID5 (left symmetric)", 1, 2, 5, ALGORITHM_LEFT_SYMMETRIC},
81 {"raid5_rs", "RAID5 (right symmetric)", 1, 2, 5, ALGORITHM_RIGHT_SYMMETRIC},
82 {"raid6_zr", "RAID6 (zero restart)", 2, 4, 6, ALGORITHM_ROTATING_ZERO_RESTART},
83 {"raid6_nr", "RAID6 (N restart)", 2, 4, 6, ALGORITHM_ROTATING_N_RESTART},
84 {"raid6_nc", "RAID6 (N continue)", 2, 4, 6, ALGORITHM_ROTATING_N_CONTINUE}
85};
86
87static struct raid_type *get_raid_type(char *name)
88{
89 int i;
90
91 for (i = 0; i < ARRAY_SIZE(raid_types); i++)
92 if (!strcmp(raid_types[i].name, name))
93 return &raid_types[i];
94
95 return NULL;
96}
97
98static struct raid_set *context_alloc(struct dm_target *ti, struct raid_type *raid_type, unsigned raid_devs)
99{
100 unsigned i;
101 struct raid_set *rs;
102 sector_t sectors_per_dev;
103
104 if (raid_devs <= raid_type->parity_devs) {
105 ti->error = "Insufficient number of devices";
106 return ERR_PTR(-EINVAL);
107 }
108
109 sectors_per_dev = ti->len;
110 if ((raid_type->level > 1) &&
111 sector_div(sectors_per_dev, (raid_devs - raid_type->parity_devs))) {
112 ti->error = "Target length not divisible by number of data devices";
113 return ERR_PTR(-EINVAL);
114 }
115
116 rs = kzalloc(sizeof(*rs) + raid_devs * sizeof(rs->dev[0]), GFP_KERNEL);
117 if (!rs) {
118 ti->error = "Cannot allocate raid context";
119 return ERR_PTR(-ENOMEM);
120 }
121
122 mddev_init(&rs->md);
123
124 rs->ti = ti;
125 rs->raid_type = raid_type;
126 rs->md.raid_disks = raid_devs;
127 rs->md.level = raid_type->level;
128 rs->md.new_level = rs->md.level;
129 rs->md.dev_sectors = sectors_per_dev;
130 rs->md.layout = raid_type->algorithm;
131 rs->md.new_layout = rs->md.layout;
132 rs->md.delta_disks = 0;
133 rs->md.recovery_cp = 0;
134
135 for (i = 0; i < raid_devs; i++)
136 md_rdev_init(&rs->dev[i].rdev);
137
138 /*
139 * Remaining items to be initialized by further RAID params:
140 * rs->md.persistent
141 * rs->md.external
142 * rs->md.chunk_sectors
143 * rs->md.new_chunk_sectors
144 */
145
146 return rs;
147}
148
149static void context_free(struct raid_set *rs)
150{
151 int i;
152
153 for (i = 0; i < rs->md.raid_disks; i++) {
154 if (rs->dev[i].meta_dev)
155 dm_put_device(rs->ti, rs->dev[i].meta_dev);
156 if (rs->dev[i].rdev.sb_page)
157 put_page(rs->dev[i].rdev.sb_page);
158 rs->dev[i].rdev.sb_page = NULL;
159 rs->dev[i].rdev.sb_loaded = 0;
160 if (rs->dev[i].data_dev)
161 dm_put_device(rs->ti, rs->dev[i].data_dev);
162 }
163
164 kfree(rs);
165}
166
167/*
168 * For every device we have two words
169 * <meta_dev>: meta device name or '-' if missing
170 * <data_dev>: data device name or '-' if missing
171 *
172 * The following are permitted:
173 * - -
174 * - <data_dev>
175 * <meta_dev> <data_dev>
176 *
177 * The following is not allowed:
178 * <meta_dev> -
179 *
180 * This code parses those words. If there is a failure,
181 * the caller must use context_free to unwind the operations.
182 */
183static int dev_parms(struct raid_set *rs, char **argv)
184{
185 int i;
186 int rebuild = 0;
187 int metadata_available = 0;
188 int ret = 0;
189
190 for (i = 0; i < rs->md.raid_disks; i++, argv += 2) {
191 rs->dev[i].rdev.raid_disk = i;
192
193 rs->dev[i].meta_dev = NULL;
194 rs->dev[i].data_dev = NULL;
195
196 /*
197 * There are no offsets, since there is a separate device
198 * for data and metadata.
199 */
200 rs->dev[i].rdev.data_offset = 0;
201 rs->dev[i].rdev.mddev = &rs->md;
202
203 if (strcmp(argv[0], "-")) {
204 ret = dm_get_device(rs->ti, argv[0],
205 dm_table_get_mode(rs->ti->table),
206 &rs->dev[i].meta_dev);
207 rs->ti->error = "RAID metadata device lookup failure";
208 if (ret)
209 return ret;
210
211 rs->dev[i].rdev.sb_page = alloc_page(GFP_KERNEL);
212 if (!rs->dev[i].rdev.sb_page)
213 return -ENOMEM;
214 }
215
216 if (!strcmp(argv[1], "-")) {
217 if (!test_bit(In_sync, &rs->dev[i].rdev.flags) &&
218 (!rs->dev[i].rdev.recovery_offset)) {
219 rs->ti->error = "Drive designated for rebuild not specified";
220 return -EINVAL;
221 }
222
223 rs->ti->error = "No data device supplied with metadata device";
224 if (rs->dev[i].meta_dev)
225 return -EINVAL;
226
227 continue;
228 }
229
230 ret = dm_get_device(rs->ti, argv[1],
231 dm_table_get_mode(rs->ti->table),
232 &rs->dev[i].data_dev);
233 if (ret) {
234 rs->ti->error = "RAID device lookup failure";
235 return ret;
236 }
237
238 if (rs->dev[i].meta_dev) {
239 metadata_available = 1;
240 rs->dev[i].rdev.meta_bdev = rs->dev[i].meta_dev->bdev;
241 }
242 rs->dev[i].rdev.bdev = rs->dev[i].data_dev->bdev;
243 list_add(&rs->dev[i].rdev.same_set, &rs->md.disks);
244 if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
245 rebuild++;
246 }
247
248 if (metadata_available) {
249 rs->md.external = 0;
250 rs->md.persistent = 1;
251 rs->md.major_version = 2;
252 } else if (rebuild && !rs->md.recovery_cp) {
253 /*
254 * Without metadata, we will not be able to tell if the array
255 * is in-sync or not - we must assume it is not. Therefore,
256 * it is impossible to rebuild a drive.
257 *
258 * Even if there is metadata, the on-disk information may
259 * indicate that the array is not in-sync and it will then
260 * fail at that time.
261 *
262 * User could specify 'nosync' option if desperate.
263 */
264 DMERR("Unable to rebuild drive while array is not in-sync");
265 rs->ti->error = "RAID device lookup failure";
266 return -EINVAL;
267 }
268
269 return 0;
270}
271
272/*
273 * validate_region_size
274 * @rs
275 * @region_size: region size in sectors. If 0, pick a size (4MiB default).
276 *
277 * Set rs->md.bitmap_info.chunksize (which really refers to 'region size').
278 * Ensure that (ti->len/region_size < 2^21) - required by MD bitmap.
279 *
280 * Returns: 0 on success, -EINVAL on failure.
281 */
282static int validate_region_size(struct raid_set *rs, unsigned long region_size)
283{
284 unsigned long min_region_size = rs->ti->len / (1 << 21);
285
286 if (!region_size) {
287 /*
288 * Choose a reasonable default. All figures in sectors.
289 */
290 if (min_region_size > (1 << 13)) {
291 DMINFO("Choosing default region size of %lu sectors",
292 region_size);
293 region_size = min_region_size;
294 } else {
295 DMINFO("Choosing default region size of 4MiB");
296 region_size = 1 << 13; /* sectors */
297 }
298 } else {
299 /*
300 * Validate user-supplied value.
301 */
302 if (region_size > rs->ti->len) {
303 rs->ti->error = "Supplied region size is too large";
304 return -EINVAL;
305 }
306
307 if (region_size < min_region_size) {
308 DMERR("Supplied region_size (%lu sectors) below minimum (%lu)",
309 region_size, min_region_size);
310 rs->ti->error = "Supplied region size is too small";
311 return -EINVAL;
312 }
313
314 if (!is_power_of_2(region_size)) {
315 rs->ti->error = "Region size is not a power of 2";
316 return -EINVAL;
317 }
318
319 if (region_size < rs->md.chunk_sectors) {
320 rs->ti->error = "Region size is smaller than the chunk size";
321 return -EINVAL;
322 }
323 }
324
325 /*
326 * Convert sectors to bytes.
327 */
328 rs->md.bitmap_info.chunksize = (region_size << 9);
329
330 return 0;
331}
332
333/*
334 * Possible arguments are...
335 * <chunk_size> [optional_args]
336 *
337 * Argument definitions
338 * <chunk_size> The number of sectors per disk that
339 * will form the "stripe"
340 * [[no]sync] Force or prevent recovery of the
341 * entire array
342 * [rebuild <idx>] Rebuild the drive indicated by the index
343 * [daemon_sleep <ms>] Time between bitmap daemon work to
344 * clear bits
345 * [min_recovery_rate <kB/sec/disk>] Throttle RAID initialization
346 * [max_recovery_rate <kB/sec/disk>] Throttle RAID initialization
347 * [write_mostly <idx>] Indicate a write mostly drive via index
348 * [max_write_behind <sectors>] See '-write-behind=' (man mdadm)
349 * [stripe_cache <sectors>] Stripe cache size for higher RAIDs
350 * [region_size <sectors>] Defines granularity of bitmap
351 */
352static int parse_raid_params(struct raid_set *rs, char **argv,
353 unsigned num_raid_params)
354{
355 unsigned i, rebuild_cnt = 0;
356 unsigned long value, region_size = 0;
357 char *key;
358
359 /*
360 * First, parse the in-order required arguments
361 * "chunk_size" is the only argument of this type.
362 */
363 if ((strict_strtoul(argv[0], 10, &value) < 0)) {
364 rs->ti->error = "Bad chunk size";
365 return -EINVAL;
366 } else if (rs->raid_type->level == 1) {
367 if (value)
368 DMERR("Ignoring chunk size parameter for RAID 1");
369 value = 0;
370 } else if (!is_power_of_2(value)) {
371 rs->ti->error = "Chunk size must be a power of 2";
372 return -EINVAL;
373 } else if (value < 8) {
374 rs->ti->error = "Chunk size value is too small";
375 return -EINVAL;
376 }
377
378 rs->md.new_chunk_sectors = rs->md.chunk_sectors = value;
379 argv++;
380 num_raid_params--;
381
382 /*
383 * We set each individual device as In_sync with a completed
384 * 'recovery_offset'. If there has been a device failure or
385 * replacement then one of the following cases applies:
386 *
387 * 1) User specifies 'rebuild'.
388 * - Device is reset when param is read.
389 * 2) A new device is supplied.
390 * - No matching superblock found, resets device.
391 * 3) Device failure was transient and returns on reload.
392 * - Failure noticed, resets device for bitmap replay.
393 * 4) Device hadn't completed recovery after previous failure.
394 * - Superblock is read and overrides recovery_offset.
395 *
396 * What is found in the superblocks of the devices is always
397 * authoritative, unless 'rebuild' or '[no]sync' was specified.
398 */
399 for (i = 0; i < rs->md.raid_disks; i++) {
400 set_bit(In_sync, &rs->dev[i].rdev.flags);
401 rs->dev[i].rdev.recovery_offset = MaxSector;
402 }
403
404 /*
405 * Second, parse the unordered optional arguments
406 */
407 for (i = 0; i < num_raid_params; i++) {
408 if (!strcasecmp(argv[i], "nosync")) {
409 rs->md.recovery_cp = MaxSector;
410 rs->print_flags |= DMPF_NOSYNC;
411 continue;
412 }
413 if (!strcasecmp(argv[i], "sync")) {
414 rs->md.recovery_cp = 0;
415 rs->print_flags |= DMPF_SYNC;
416 continue;
417 }
418
419 /* The rest of the optional arguments come in key/value pairs */
420 if ((i + 1) >= num_raid_params) {
421 rs->ti->error = "Wrong number of raid parameters given";
422 return -EINVAL;
423 }
424
425 key = argv[i++];
426 if (strict_strtoul(argv[i], 10, &value) < 0) {
427 rs->ti->error = "Bad numerical argument given in raid params";
428 return -EINVAL;
429 }
430
431 if (!strcasecmp(key, "rebuild")) {
432 rebuild_cnt++;
433 if (((rs->raid_type->level != 1) &&
434 (rebuild_cnt > rs->raid_type->parity_devs)) ||
435 ((rs->raid_type->level == 1) &&
436 (rebuild_cnt > (rs->md.raid_disks - 1)))) {
437 rs->ti->error = "Too many rebuild devices specified for given RAID type";
438 return -EINVAL;
439 }
440 if (value > rs->md.raid_disks) {
441 rs->ti->error = "Invalid rebuild index given";
442 return -EINVAL;
443 }
444 clear_bit(In_sync, &rs->dev[value].rdev.flags);
445 rs->dev[value].rdev.recovery_offset = 0;
446 rs->print_flags |= DMPF_REBUILD;
447 } else if (!strcasecmp(key, "write_mostly")) {
448 if (rs->raid_type->level != 1) {
449 rs->ti->error = "write_mostly option is only valid for RAID1";
450 return -EINVAL;
451 }
452 if (value >= rs->md.raid_disks) {
453 rs->ti->error = "Invalid write_mostly drive index given";
454 return -EINVAL;
455 }
456 set_bit(WriteMostly, &rs->dev[value].rdev.flags);
457 } else if (!strcasecmp(key, "max_write_behind")) {
458 if (rs->raid_type->level != 1) {
459 rs->ti->error = "max_write_behind option is only valid for RAID1";
460 return -EINVAL;
461 }
462 rs->print_flags |= DMPF_MAX_WRITE_BEHIND;
463
464 /*
465 * In device-mapper, we specify things in sectors, but
466 * MD records this value in kB
467 */
468 value /= 2;
469 if (value > COUNTER_MAX) {
470 rs->ti->error = "Max write-behind limit out of range";
471 return -EINVAL;
472 }
473 rs->md.bitmap_info.max_write_behind = value;
474 } else if (!strcasecmp(key, "daemon_sleep")) {
475 rs->print_flags |= DMPF_DAEMON_SLEEP;
476 if (!value || (value > MAX_SCHEDULE_TIMEOUT)) {
477 rs->ti->error = "daemon sleep period out of range";
478 return -EINVAL;
479 }
480 rs->md.bitmap_info.daemon_sleep = value;
481 } else if (!strcasecmp(key, "stripe_cache")) {
482 rs->print_flags |= DMPF_STRIPE_CACHE;
483
484 /*
485 * In device-mapper, we specify things in sectors, but
486 * MD records this value in kB
487 */
488 value /= 2;
489
490 if (rs->raid_type->level < 5) {
491 rs->ti->error = "Inappropriate argument: stripe_cache";
492 return -EINVAL;
493 }
494 if (raid5_set_cache_size(&rs->md, (int)value)) {
495 rs->ti->error = "Bad stripe_cache size";
496 return -EINVAL;
497 }
498 } else if (!strcasecmp(key, "min_recovery_rate")) {
499 rs->print_flags |= DMPF_MIN_RECOVERY_RATE;
500 if (value > INT_MAX) {
501 rs->ti->error = "min_recovery_rate out of range";
502 return -EINVAL;
503 }
504 rs->md.sync_speed_min = (int)value;
505 } else if (!strcasecmp(key, "max_recovery_rate")) {
506 rs->print_flags |= DMPF_MAX_RECOVERY_RATE;
507 if (value > INT_MAX) {
508 rs->ti->error = "max_recovery_rate out of range";
509 return -EINVAL;
510 }
511 rs->md.sync_speed_max = (int)value;
512 } else if (!strcasecmp(key, "region_size")) {
513 rs->print_flags |= DMPF_REGION_SIZE;
514 region_size = value;
515 } else {
516 DMERR("Unable to parse RAID parameter: %s", key);
517 rs->ti->error = "Unable to parse RAID parameters";
518 return -EINVAL;
519 }
520 }
521
522 if (validate_region_size(rs, region_size))
523 return -EINVAL;
524
525 if (rs->md.chunk_sectors)
526 rs->ti->split_io = rs->md.chunk_sectors;
527 else
528 rs->ti->split_io = region_size;
529
530 if (rs->md.chunk_sectors)
531 rs->ti->split_io = rs->md.chunk_sectors;
532 else
533 rs->ti->split_io = region_size;
534
535 /* Assume there are no metadata devices until the drives are parsed */
536 rs->md.persistent = 0;
537 rs->md.external = 1;
538
539 return 0;
540}
541
542static void do_table_event(struct work_struct *ws)
543{
544 struct raid_set *rs = container_of(ws, struct raid_set, md.event_work);
545
546 dm_table_event(rs->ti->table);
547}
548
549static int raid_is_congested(struct dm_target_callbacks *cb, int bits)
550{
551 struct raid_set *rs = container_of(cb, struct raid_set, callbacks);
552
553 if (rs->raid_type->level == 1)
554 return md_raid1_congested(&rs->md, bits);
555
556 return md_raid5_congested(&rs->md, bits);
557}
558
559/*
560 * This structure is never routinely used by userspace, unlike md superblocks.
561 * Devices with this superblock should only ever be accessed via device-mapper.
562 */
563#define DM_RAID_MAGIC 0x64526D44
564struct dm_raid_superblock {
565 __le32 magic; /* "DmRd" */
566 __le32 features; /* Used to indicate possible future changes */
567
568 __le32 num_devices; /* Number of devices in this array. (Max 64) */
569 __le32 array_position; /* The position of this drive in the array */
570
571 __le64 events; /* Incremented by md when superblock updated */
572 __le64 failed_devices; /* Bit field of devices to indicate failures */
573
574 /*
575 * This offset tracks the progress of the repair or replacement of
576 * an individual drive.
577 */
578 __le64 disk_recovery_offset;
579
580 /*
581 * This offset tracks the progress of the initial array
582 * synchronisation/parity calculation.
583 */
584 __le64 array_resync_offset;
585
586 /*
587 * RAID characteristics
588 */
589 __le32 level;
590 __le32 layout;
591 __le32 stripe_sectors;
592
593 __u8 pad[452]; /* Round struct to 512 bytes. */
594 /* Always set to 0 when writing. */
595} __packed;
596
597static int read_disk_sb(mdk_rdev_t *rdev, int size)
598{
599 BUG_ON(!rdev->sb_page);
600
601 if (rdev->sb_loaded)
602 return 0;
603
604 if (!sync_page_io(rdev, 0, size, rdev->sb_page, READ, 1)) {
605 DMERR("Failed to read device superblock");
606 return -EINVAL;
607 }
608
609 rdev->sb_loaded = 1;
610
611 return 0;
612}
613
614static void super_sync(mddev_t *mddev, mdk_rdev_t *rdev)
615{
616 mdk_rdev_t *r, *t;
617 uint64_t failed_devices;
618 struct dm_raid_superblock *sb;
619
620 sb = page_address(rdev->sb_page);
621 failed_devices = le64_to_cpu(sb->failed_devices);
622
623 rdev_for_each(r, t, mddev)
624 if ((r->raid_disk >= 0) && test_bit(Faulty, &r->flags))
625 failed_devices |= (1ULL << r->raid_disk);
626
627 memset(sb, 0, sizeof(*sb));
628
629 sb->magic = cpu_to_le32(DM_RAID_MAGIC);
630 sb->features = cpu_to_le32(0); /* No features yet */
631
632 sb->num_devices = cpu_to_le32(mddev->raid_disks);
633 sb->array_position = cpu_to_le32(rdev->raid_disk);
634
635 sb->events = cpu_to_le64(mddev->events);
636 sb->failed_devices = cpu_to_le64(failed_devices);
637
638 sb->disk_recovery_offset = cpu_to_le64(rdev->recovery_offset);
639 sb->array_resync_offset = cpu_to_le64(mddev->recovery_cp);
640
641 sb->level = cpu_to_le32(mddev->level);
642 sb->layout = cpu_to_le32(mddev->layout);
643 sb->stripe_sectors = cpu_to_le32(mddev->chunk_sectors);
644}
645
646/*
647 * super_load
648 *
649 * This function creates a superblock if one is not found on the device
650 * and will decide which superblock to use if there's a choice.
651 *
652 * Return: 1 if use rdev, 0 if use refdev, -Exxx otherwise
653 */
654static int super_load(mdk_rdev_t *rdev, mdk_rdev_t *refdev)
655{
656 int ret;
657 struct dm_raid_superblock *sb;
658 struct dm_raid_superblock *refsb;
659 uint64_t events_sb, events_refsb;
660
661 rdev->sb_start = 0;
662 rdev->sb_size = sizeof(*sb);
663
664 ret = read_disk_sb(rdev, rdev->sb_size);
665 if (ret)
666 return ret;
667
668 sb = page_address(rdev->sb_page);
669 if (sb->magic != cpu_to_le32(DM_RAID_MAGIC)) {
670 super_sync(rdev->mddev, rdev);
671
672 set_bit(FirstUse, &rdev->flags);
673
674 /* Force writing of superblocks to disk */
675 set_bit(MD_CHANGE_DEVS, &rdev->mddev->flags);
676
677 /* Any superblock is better than none, choose that if given */
678 return refdev ? 0 : 1;
679 }
680
681 if (!refdev)
682 return 1;
683
684 events_sb = le64_to_cpu(sb->events);
685
686 refsb = page_address(refdev->sb_page);
687 events_refsb = le64_to_cpu(refsb->events);
688
689 return (events_sb > events_refsb) ? 1 : 0;
690}
691
692static int super_init_validation(mddev_t *mddev, mdk_rdev_t *rdev)
693{
694 int role;
695 struct raid_set *rs = container_of(mddev, struct raid_set, md);
696 uint64_t events_sb;
697 uint64_t failed_devices;
698 struct dm_raid_superblock *sb;
699 uint32_t new_devs = 0;
700 uint32_t rebuilds = 0;
701 mdk_rdev_t *r, *t;
702 struct dm_raid_superblock *sb2;
703
704 sb = page_address(rdev->sb_page);
705 events_sb = le64_to_cpu(sb->events);
706 failed_devices = le64_to_cpu(sb->failed_devices);
707
708 /*
709 * Initialise to 1 if this is a new superblock.
710 */
711 mddev->events = events_sb ? : 1;
712
713 /*
714 * Reshaping is not currently allowed
715 */
716 if ((le32_to_cpu(sb->level) != mddev->level) ||
717 (le32_to_cpu(sb->layout) != mddev->layout) ||
718 (le32_to_cpu(sb->stripe_sectors) != mddev->chunk_sectors)) {
719 DMERR("Reshaping arrays not yet supported.");
720 return -EINVAL;
721 }
722
723 /* We can only change the number of devices in RAID1 right now */
724 if ((rs->raid_type->level != 1) &&
725 (le32_to_cpu(sb->num_devices) != mddev->raid_disks)) {
726 DMERR("Reshaping arrays not yet supported.");
727 return -EINVAL;
728 }
729
730 if (!(rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC)))
731 mddev->recovery_cp = le64_to_cpu(sb->array_resync_offset);
732
733 /*
734 * During load, we set FirstUse if a new superblock was written.
735 * There are two reasons we might not have a superblock:
736 * 1) The array is brand new - in which case, all of the
737 * devices must have their In_sync bit set. Also,
738 * recovery_cp must be 0, unless forced.
739 * 2) This is a new device being added to an old array
740 * and the new device needs to be rebuilt - in which
741 * case the In_sync bit will /not/ be set and
742 * recovery_cp must be MaxSector.
743 */
744 rdev_for_each(r, t, mddev) {
745 if (!test_bit(In_sync, &r->flags)) {
746 if (!test_bit(FirstUse, &r->flags))
747 DMERR("Superblock area of "
748 "rebuild device %d should have been "
749 "cleared.", r->raid_disk);
750 set_bit(FirstUse, &r->flags);
751 rebuilds++;
752 } else if (test_bit(FirstUse, &r->flags))
753 new_devs++;
754 }
755
756 if (!rebuilds) {
757 if (new_devs == mddev->raid_disks) {
758 DMINFO("Superblocks created for new array");
759 set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
760 } else if (new_devs) {
761 DMERR("New device injected "
762 "into existing array without 'rebuild' "
763 "parameter specified");
764 return -EINVAL;
765 }
766 } else if (new_devs) {
767 DMERR("'rebuild' devices cannot be "
768 "injected into an array with other first-time devices");
769 return -EINVAL;
770 } else if (mddev->recovery_cp != MaxSector) {
771 DMERR("'rebuild' specified while array is not in-sync");
772 return -EINVAL;
773 }
774
775 /*
776 * Now we set the Faulty bit for those devices that are
777 * recorded in the superblock as failed.
778 */
779 rdev_for_each(r, t, mddev) {
780 if (!r->sb_page)
781 continue;
782 sb2 = page_address(r->sb_page);
783 sb2->failed_devices = 0;
784
785 /*
786 * Check for any device re-ordering.
787 */
788 if (!test_bit(FirstUse, &r->flags) && (r->raid_disk >= 0)) {
789 role = le32_to_cpu(sb2->array_position);
790 if (role != r->raid_disk) {
791 if (rs->raid_type->level != 1) {
792 rs->ti->error = "Cannot change device "
793 "positions in RAID array";
794 return -EINVAL;
795 }
796 DMINFO("RAID1 device #%d now at position #%d",
797 role, r->raid_disk);
798 }
799
800 /*
801 * Partial recovery is performed on
802 * returning failed devices.
803 */
804 if (failed_devices & (1 << role))
805 set_bit(Faulty, &r->flags);
806 }
807 }
808
809 return 0;
810}
811
812static int super_validate(mddev_t *mddev, mdk_rdev_t *rdev)
813{
814 struct dm_raid_superblock *sb = page_address(rdev->sb_page);
815
816 /*
817 * If mddev->events is not set, we know we have not yet initialized
818 * the array.
819 */
820 if (!mddev->events && super_init_validation(mddev, rdev))
821 return -EINVAL;
822
823 mddev->bitmap_info.offset = 4096 >> 9; /* Enable bitmap creation */
824 rdev->mddev->bitmap_info.default_offset = 4096 >> 9;
825 if (!test_bit(FirstUse, &rdev->flags)) {
826 rdev->recovery_offset = le64_to_cpu(sb->disk_recovery_offset);
827 if (rdev->recovery_offset != MaxSector)
828 clear_bit(In_sync, &rdev->flags);
829 }
830
831 /*
832 * If a device comes back, set it as not In_sync and no longer faulty.
833 */
834 if (test_bit(Faulty, &rdev->flags)) {
835 clear_bit(Faulty, &rdev->flags);
836 clear_bit(In_sync, &rdev->flags);
837 rdev->saved_raid_disk = rdev->raid_disk;
838 rdev->recovery_offset = 0;
839 }
840
841 clear_bit(FirstUse, &rdev->flags);
842
843 return 0;
844}
845
846/*
847 * Analyse superblocks and select the freshest.
848 */
849static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
850{
851 int ret;
852 mdk_rdev_t *rdev, *freshest, *tmp;
853 mddev_t *mddev = &rs->md;
854
855 freshest = NULL;
856 rdev_for_each(rdev, tmp, mddev) {
857 if (!rdev->meta_bdev)
858 continue;
859
860 ret = super_load(rdev, freshest);
861
862 switch (ret) {
863 case 1:
864 freshest = rdev;
865 break;
866 case 0:
867 break;
868 default:
869 ti->error = "Failed to load superblock";
870 return ret;
871 }
872 }
873
874 if (!freshest)
875 return 0;
876
877 /*
878 * Validation of the freshest device provides the source of
879 * validation for the remaining devices.
880 */
881 ti->error = "Unable to assemble array: Invalid superblocks";
882 if (super_validate(mddev, freshest))
883 return -EINVAL;
884
885 rdev_for_each(rdev, tmp, mddev)
886 if ((rdev != freshest) && super_validate(mddev, rdev))
887 return -EINVAL;
888
889 return 0;
890}
891
892/*
893 * Construct a RAID4/5/6 mapping:
894 * Args:
895 * <raid_type> <#raid_params> <raid_params> \
896 * <#raid_devs> { <meta_dev1> <dev1> .. <meta_devN> <devN> }
897 *
898 * <raid_params> varies by <raid_type>. See 'parse_raid_params' for
899 * details on possible <raid_params>.
900 */
901static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
902{
903 int ret;
904 struct raid_type *rt;
905 unsigned long num_raid_params, num_raid_devs;
906 struct raid_set *rs = NULL;
907
908 /* Must have at least <raid_type> <#raid_params> */
909 if (argc < 2) {
910 ti->error = "Too few arguments";
911 return -EINVAL;
912 }
913
914 /* raid type */
915 rt = get_raid_type(argv[0]);
916 if (!rt) {
917 ti->error = "Unrecognised raid_type";
918 return -EINVAL;
919 }
920 argc--;
921 argv++;
922
923 /* number of RAID parameters */
924 if (strict_strtoul(argv[0], 10, &num_raid_params) < 0) {
925 ti->error = "Cannot understand number of RAID parameters";
926 return -EINVAL;
927 }
928 argc--;
929 argv++;
930
931 /* Skip over RAID params for now and find out # of devices */
932 if (num_raid_params + 1 > argc) {
933 ti->error = "Arguments do not agree with counts given";
934 return -EINVAL;
935 }
936
937 if ((strict_strtoul(argv[num_raid_params], 10, &num_raid_devs) < 0) ||
938 (num_raid_devs >= INT_MAX)) {
939 ti->error = "Cannot understand number of raid devices";
940 return -EINVAL;
941 }
942
943 rs = context_alloc(ti, rt, (unsigned)num_raid_devs);
944 if (IS_ERR(rs))
945 return PTR_ERR(rs);
946
947 ret = parse_raid_params(rs, argv, (unsigned)num_raid_params);
948 if (ret)
949 goto bad;
950
951 ret = -EINVAL;
952
953 argc -= num_raid_params + 1; /* +1: we already have num_raid_devs */
954 argv += num_raid_params + 1;
955
956 if (argc != (num_raid_devs * 2)) {
957 ti->error = "Supplied RAID devices does not match the count given";
958 goto bad;
959 }
960
961 ret = dev_parms(rs, argv);
962 if (ret)
963 goto bad;
964
965 rs->md.sync_super = super_sync;
966 ret = analyse_superblocks(ti, rs);
967 if (ret)
968 goto bad;
969
970 INIT_WORK(&rs->md.event_work, do_table_event);
971 ti->private = rs;
972
973 mutex_lock(&rs->md.reconfig_mutex);
974 ret = md_run(&rs->md);
975 rs->md.in_sync = 0; /* Assume already marked dirty */
976 mutex_unlock(&rs->md.reconfig_mutex);
977
978 if (ret) {
979 ti->error = "Fail to run raid array";
980 goto bad;
981 }
982
983 rs->callbacks.congested_fn = raid_is_congested;
984 dm_table_add_target_callbacks(ti->table, &rs->callbacks);
985
986 mddev_suspend(&rs->md);
987 return 0;
988
989bad:
990 context_free(rs);
991
992 return ret;
993}
994
995static void raid_dtr(struct dm_target *ti)
996{
997 struct raid_set *rs = ti->private;
998
999 list_del_init(&rs->callbacks.list);
1000 md_stop(&rs->md);
1001 context_free(rs);
1002}
1003
1004static int raid_map(struct dm_target *ti, struct bio *bio, union map_info *map_context)
1005{
1006 struct raid_set *rs = ti->private;
1007 mddev_t *mddev = &rs->md;
1008
1009 mddev->pers->make_request(mddev, bio);
1010
1011 return DM_MAPIO_SUBMITTED;
1012}
1013
1014static int raid_status(struct dm_target *ti, status_type_t type,
1015 char *result, unsigned maxlen)
1016{
1017 struct raid_set *rs = ti->private;
1018 unsigned raid_param_cnt = 1; /* at least 1 for chunksize */
1019 unsigned sz = 0;
1020 int i;
1021 sector_t sync;
1022
1023 switch (type) {
1024 case STATUSTYPE_INFO:
1025 DMEMIT("%s %d ", rs->raid_type->name, rs->md.raid_disks);
1026
1027 for (i = 0; i < rs->md.raid_disks; i++) {
1028 if (test_bit(Faulty, &rs->dev[i].rdev.flags))
1029 DMEMIT("D");
1030 else if (test_bit(In_sync, &rs->dev[i].rdev.flags))
1031 DMEMIT("A");
1032 else
1033 DMEMIT("a");
1034 }
1035
1036 if (test_bit(MD_RECOVERY_RUNNING, &rs->md.recovery))
1037 sync = rs->md.curr_resync_completed;
1038 else
1039 sync = rs->md.recovery_cp;
1040
1041 if (sync > rs->md.resync_max_sectors)
1042 sync = rs->md.resync_max_sectors;
1043
1044 DMEMIT(" %llu/%llu",
1045 (unsigned long long) sync,
1046 (unsigned long long) rs->md.resync_max_sectors);
1047
1048 break;
1049 case STATUSTYPE_TABLE:
1050 /* The string you would use to construct this array */
1051 for (i = 0; i < rs->md.raid_disks; i++) {
1052 if ((rs->print_flags & DMPF_REBUILD) &&
1053 rs->dev[i].data_dev &&
1054 !test_bit(In_sync, &rs->dev[i].rdev.flags))
1055 raid_param_cnt += 2; /* for rebuilds */
1056 if (rs->dev[i].data_dev &&
1057 test_bit(WriteMostly, &rs->dev[i].rdev.flags))
1058 raid_param_cnt += 2;
1059 }
1060
1061 raid_param_cnt += (hweight64(rs->print_flags & ~DMPF_REBUILD) * 2);
1062 if (rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC))
1063 raid_param_cnt--;
1064
1065 DMEMIT("%s %u %u", rs->raid_type->name,
1066 raid_param_cnt, rs->md.chunk_sectors);
1067
1068 if ((rs->print_flags & DMPF_SYNC) &&
1069 (rs->md.recovery_cp == MaxSector))
1070 DMEMIT(" sync");
1071 if (rs->print_flags & DMPF_NOSYNC)
1072 DMEMIT(" nosync");
1073
1074 for (i = 0; i < rs->md.raid_disks; i++)
1075 if ((rs->print_flags & DMPF_REBUILD) &&
1076 rs->dev[i].data_dev &&
1077 !test_bit(In_sync, &rs->dev[i].rdev.flags))
1078 DMEMIT(" rebuild %u", i);
1079
1080 if (rs->print_flags & DMPF_DAEMON_SLEEP)
1081 DMEMIT(" daemon_sleep %lu",
1082 rs->md.bitmap_info.daemon_sleep);
1083
1084 if (rs->print_flags & DMPF_MIN_RECOVERY_RATE)
1085 DMEMIT(" min_recovery_rate %d", rs->md.sync_speed_min);
1086
1087 if (rs->print_flags & DMPF_MAX_RECOVERY_RATE)
1088 DMEMIT(" max_recovery_rate %d", rs->md.sync_speed_max);
1089
1090 for (i = 0; i < rs->md.raid_disks; i++)
1091 if (rs->dev[i].data_dev &&
1092 test_bit(WriteMostly, &rs->dev[i].rdev.flags))
1093 DMEMIT(" write_mostly %u", i);
1094
1095 if (rs->print_flags & DMPF_MAX_WRITE_BEHIND)
1096 DMEMIT(" max_write_behind %lu",
1097 rs->md.bitmap_info.max_write_behind);
1098
1099 if (rs->print_flags & DMPF_STRIPE_CACHE) {
1100 raid5_conf_t *conf = rs->md.private;
1101
1102 /* convert from kiB to sectors */
1103 DMEMIT(" stripe_cache %d",
1104 conf ? conf->max_nr_stripes * 2 : 0);
1105 }
1106
1107 if (rs->print_flags & DMPF_REGION_SIZE)
1108 DMEMIT(" region_size %lu",
1109 rs->md.bitmap_info.chunksize >> 9);
1110
1111 DMEMIT(" %d", rs->md.raid_disks);
1112 for (i = 0; i < rs->md.raid_disks; i++) {
1113 if (rs->dev[i].meta_dev)
1114 DMEMIT(" %s", rs->dev[i].meta_dev->name);
1115 else
1116 DMEMIT(" -");
1117
1118 if (rs->dev[i].data_dev)
1119 DMEMIT(" %s", rs->dev[i].data_dev->name);
1120 else
1121 DMEMIT(" -");
1122 }
1123 }
1124
1125 return 0;
1126}
1127
1128static int raid_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data)
1129{
1130 struct raid_set *rs = ti->private;
1131 unsigned i;
1132 int ret = 0;
1133
1134 for (i = 0; !ret && i < rs->md.raid_disks; i++)
1135 if (rs->dev[i].data_dev)
1136 ret = fn(ti,
1137 rs->dev[i].data_dev,
1138 0, /* No offset on data devs */
1139 rs->md.dev_sectors,
1140 data);
1141
1142 return ret;
1143}
1144
1145static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
1146{
1147 struct raid_set *rs = ti->private;
1148 unsigned chunk_size = rs->md.chunk_sectors << 9;
1149 raid5_conf_t *conf = rs->md.private;
1150
1151 blk_limits_io_min(limits, chunk_size);
1152 blk_limits_io_opt(limits, chunk_size * (conf->raid_disks - conf->max_degraded));
1153}
1154
1155static void raid_presuspend(struct dm_target *ti)
1156{
1157 struct raid_set *rs = ti->private;
1158
1159 md_stop_writes(&rs->md);
1160}
1161
1162static void raid_postsuspend(struct dm_target *ti)
1163{
1164 struct raid_set *rs = ti->private;
1165
1166 mddev_suspend(&rs->md);
1167}
1168
1169static void raid_resume(struct dm_target *ti)
1170{
1171 struct raid_set *rs = ti->private;
1172
1173 bitmap_load(&rs->md);
1174 mddev_resume(&rs->md);
1175}
1176
1177static struct target_type raid_target = {
1178 .name = "raid",
1179 .version = {1, 1, 0},
1180 .module = THIS_MODULE,
1181 .ctr = raid_ctr,
1182 .dtr = raid_dtr,
1183 .map = raid_map,
1184 .status = raid_status,
1185 .iterate_devices = raid_iterate_devices,
1186 .io_hints = raid_io_hints,
1187 .presuspend = raid_presuspend,
1188 .postsuspend = raid_postsuspend,
1189 .resume = raid_resume,
1190};
1191
1192static int __init dm_raid_init(void)
1193{
1194 return dm_register_target(&raid_target);
1195}
1196
1197static void __exit dm_raid_exit(void)
1198{
1199 dm_unregister_target(&raid_target);
1200}
1201
1202module_init(dm_raid_init);
1203module_exit(dm_raid_exit);
1204
1205MODULE_DESCRIPTION(DM_NAME " raid4/5/6 target");
1206MODULE_ALIAS("dm-raid4");
1207MODULE_ALIAS("dm-raid5");
1208MODULE_ALIAS("dm-raid6");
1209MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>");
1210MODULE_LICENSE("GPL");
1/*
2 * Copyright (C) 2010-2011 Neil Brown
3 * Copyright (C) 2010-2015 Red Hat, Inc. All rights reserved.
4 *
5 * This file is released under the GPL.
6 */
7
8#include <linux/slab.h>
9#include <linux/module.h>
10
11#include "md.h"
12#include "raid1.h"
13#include "raid5.h"
14#include "raid10.h"
15#include "bitmap.h"
16
17#include <linux/device-mapper.h>
18
19#define DM_MSG_PREFIX "raid"
20#define MAX_RAID_DEVICES 253 /* raid4/5/6 limit */
21
22static bool devices_handle_discard_safely = false;
23
24/*
25 * The following flags are used by dm-raid.c to set up the array state.
26 * They must be cleared before md_run is called.
27 */
28#define FirstUse 10 /* rdev flag */
29
30struct raid_dev {
31 /*
32 * Two DM devices, one to hold metadata and one to hold the
33 * actual data/parity. The reason for this is to not confuse
34 * ti->len and give more flexibility in altering size and
35 * characteristics.
36 *
37 * While it is possible for this device to be associated
38 * with a different physical device than the data_dev, it
39 * is intended for it to be the same.
40 * |--------- Physical Device ---------|
41 * |- meta_dev -|------ data_dev ------|
42 */
43 struct dm_dev *meta_dev;
44 struct dm_dev *data_dev;
45 struct md_rdev rdev;
46};
47
48/*
49 * Flags for rs->ctr_flags field.
50 */
51#define CTR_FLAG_SYNC 0x1
52#define CTR_FLAG_NOSYNC 0x2
53#define CTR_FLAG_REBUILD 0x4
54#define CTR_FLAG_DAEMON_SLEEP 0x8
55#define CTR_FLAG_MIN_RECOVERY_RATE 0x10
56#define CTR_FLAG_MAX_RECOVERY_RATE 0x20
57#define CTR_FLAG_MAX_WRITE_BEHIND 0x40
58#define CTR_FLAG_STRIPE_CACHE 0x80
59#define CTR_FLAG_REGION_SIZE 0x100
60#define CTR_FLAG_RAID10_COPIES 0x200
61#define CTR_FLAG_RAID10_FORMAT 0x400
62
63struct raid_set {
64 struct dm_target *ti;
65
66 uint32_t bitmap_loaded;
67 uint32_t ctr_flags;
68
69 struct mddev md;
70 struct raid_type *raid_type;
71 struct dm_target_callbacks callbacks;
72
73 struct raid_dev dev[0];
74};
75
76/* Supported raid types and properties. */
77static struct raid_type {
78 const char *name; /* RAID algorithm. */
79 const char *descr; /* Descriptor text for logging. */
80 const unsigned parity_devs; /* # of parity devices. */
81 const unsigned minimal_devs; /* minimal # of devices in set. */
82 const unsigned level; /* RAID level. */
83 const unsigned algorithm; /* RAID algorithm. */
84} raid_types[] = {
85 {"raid0", "RAID0 (striping)", 0, 2, 0, 0 /* NONE */},
86 {"raid1", "RAID1 (mirroring)", 0, 2, 1, 0 /* NONE */},
87 {"raid10", "RAID10 (striped mirrors)", 0, 2, 10, UINT_MAX /* Varies */},
88 {"raid4", "RAID4 (dedicated parity disk)", 1, 2, 5, ALGORITHM_PARITY_0},
89 {"raid5_la", "RAID5 (left asymmetric)", 1, 2, 5, ALGORITHM_LEFT_ASYMMETRIC},
90 {"raid5_ra", "RAID5 (right asymmetric)", 1, 2, 5, ALGORITHM_RIGHT_ASYMMETRIC},
91 {"raid5_ls", "RAID5 (left symmetric)", 1, 2, 5, ALGORITHM_LEFT_SYMMETRIC},
92 {"raid5_rs", "RAID5 (right symmetric)", 1, 2, 5, ALGORITHM_RIGHT_SYMMETRIC},
93 {"raid6_zr", "RAID6 (zero restart)", 2, 4, 6, ALGORITHM_ROTATING_ZERO_RESTART},
94 {"raid6_nr", "RAID6 (N restart)", 2, 4, 6, ALGORITHM_ROTATING_N_RESTART},
95 {"raid6_nc", "RAID6 (N continue)", 2, 4, 6, ALGORITHM_ROTATING_N_CONTINUE}
96};
97
98static char *raid10_md_layout_to_format(int layout)
99{
100 /*
101 * Bit 16 and 17 stand for "offset" and "use_far_sets"
102 * Refer to MD's raid10.c for details
103 */
104 if ((layout & 0x10000) && (layout & 0x20000))
105 return "offset";
106
107 if ((layout & 0xFF) > 1)
108 return "near";
109
110 return "far";
111}
112
113static unsigned raid10_md_layout_to_copies(int layout)
114{
115 if ((layout & 0xFF) > 1)
116 return layout & 0xFF;
117 return (layout >> 8) & 0xFF;
118}
119
120static int raid10_format_to_md_layout(char *format, unsigned copies)
121{
122 unsigned n = 1, f = 1;
123
124 if (!strcasecmp("near", format))
125 n = copies;
126 else
127 f = copies;
128
129 if (!strcasecmp("offset", format))
130 return 0x30000 | (f << 8) | n;
131
132 if (!strcasecmp("far", format))
133 return 0x20000 | (f << 8) | n;
134
135 return (f << 8) | n;
136}
137
138static struct raid_type *get_raid_type(char *name)
139{
140 int i;
141
142 for (i = 0; i < ARRAY_SIZE(raid_types); i++)
143 if (!strcmp(raid_types[i].name, name))
144 return &raid_types[i];
145
146 return NULL;
147}
148
149static struct raid_set *context_alloc(struct dm_target *ti, struct raid_type *raid_type, unsigned raid_devs)
150{
151 unsigned i;
152 struct raid_set *rs;
153
154 if (raid_devs <= raid_type->parity_devs) {
155 ti->error = "Insufficient number of devices";
156 return ERR_PTR(-EINVAL);
157 }
158
159 rs = kzalloc(sizeof(*rs) + raid_devs * sizeof(rs->dev[0]), GFP_KERNEL);
160 if (!rs) {
161 ti->error = "Cannot allocate raid context";
162 return ERR_PTR(-ENOMEM);
163 }
164
165 mddev_init(&rs->md);
166
167 rs->ti = ti;
168 rs->raid_type = raid_type;
169 rs->md.raid_disks = raid_devs;
170 rs->md.level = raid_type->level;
171 rs->md.new_level = rs->md.level;
172 rs->md.layout = raid_type->algorithm;
173 rs->md.new_layout = rs->md.layout;
174 rs->md.delta_disks = 0;
175 rs->md.recovery_cp = 0;
176
177 for (i = 0; i < raid_devs; i++)
178 md_rdev_init(&rs->dev[i].rdev);
179
180 /*
181 * Remaining items to be initialized by further RAID params:
182 * rs->md.persistent
183 * rs->md.external
184 * rs->md.chunk_sectors
185 * rs->md.new_chunk_sectors
186 * rs->md.dev_sectors
187 */
188
189 return rs;
190}
191
192static void context_free(struct raid_set *rs)
193{
194 int i;
195
196 for (i = 0; i < rs->md.raid_disks; i++) {
197 if (rs->dev[i].meta_dev)
198 dm_put_device(rs->ti, rs->dev[i].meta_dev);
199 md_rdev_clear(&rs->dev[i].rdev);
200 if (rs->dev[i].data_dev)
201 dm_put_device(rs->ti, rs->dev[i].data_dev);
202 }
203
204 kfree(rs);
205}
206
207/*
208 * For every device we have two words
209 * <meta_dev>: meta device name or '-' if missing
210 * <data_dev>: data device name or '-' if missing
211 *
212 * The following are permitted:
213 * - -
214 * - <data_dev>
215 * <meta_dev> <data_dev>
216 *
217 * The following is not allowed:
218 * <meta_dev> -
219 *
220 * This code parses those words. If there is a failure,
221 * the caller must use context_free to unwind the operations.
222 */
223static int dev_parms(struct raid_set *rs, char **argv)
224{
225 int i;
226 int rebuild = 0;
227 int metadata_available = 0;
228 int ret = 0;
229
230 for (i = 0; i < rs->md.raid_disks; i++, argv += 2) {
231 rs->dev[i].rdev.raid_disk = i;
232
233 rs->dev[i].meta_dev = NULL;
234 rs->dev[i].data_dev = NULL;
235
236 /*
237 * There are no offsets, since there is a separate device
238 * for data and metadata.
239 */
240 rs->dev[i].rdev.data_offset = 0;
241 rs->dev[i].rdev.mddev = &rs->md;
242
243 if (strcmp(argv[0], "-")) {
244 ret = dm_get_device(rs->ti, argv[0],
245 dm_table_get_mode(rs->ti->table),
246 &rs->dev[i].meta_dev);
247 rs->ti->error = "RAID metadata device lookup failure";
248 if (ret)
249 return ret;
250
251 rs->dev[i].rdev.sb_page = alloc_page(GFP_KERNEL);
252 if (!rs->dev[i].rdev.sb_page)
253 return -ENOMEM;
254 }
255
256 if (!strcmp(argv[1], "-")) {
257 if (!test_bit(In_sync, &rs->dev[i].rdev.flags) &&
258 (!rs->dev[i].rdev.recovery_offset)) {
259 rs->ti->error = "Drive designated for rebuild not specified";
260 return -EINVAL;
261 }
262
263 rs->ti->error = "No data device supplied with metadata device";
264 if (rs->dev[i].meta_dev)
265 return -EINVAL;
266
267 continue;
268 }
269
270 ret = dm_get_device(rs->ti, argv[1],
271 dm_table_get_mode(rs->ti->table),
272 &rs->dev[i].data_dev);
273 if (ret) {
274 rs->ti->error = "RAID device lookup failure";
275 return ret;
276 }
277
278 if (rs->dev[i].meta_dev) {
279 metadata_available = 1;
280 rs->dev[i].rdev.meta_bdev = rs->dev[i].meta_dev->bdev;
281 }
282 rs->dev[i].rdev.bdev = rs->dev[i].data_dev->bdev;
283 list_add(&rs->dev[i].rdev.same_set, &rs->md.disks);
284 if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
285 rebuild++;
286 }
287
288 if (metadata_available) {
289 rs->md.external = 0;
290 rs->md.persistent = 1;
291 rs->md.major_version = 2;
292 } else if (rebuild && !rs->md.recovery_cp) {
293 /*
294 * Without metadata, we will not be able to tell if the array
295 * is in-sync or not - we must assume it is not. Therefore,
296 * it is impossible to rebuild a drive.
297 *
298 * Even if there is metadata, the on-disk information may
299 * indicate that the array is not in-sync and it will then
300 * fail at that time.
301 *
302 * User could specify 'nosync' option if desperate.
303 */
304 DMERR("Unable to rebuild drive while array is not in-sync");
305 rs->ti->error = "RAID device lookup failure";
306 return -EINVAL;
307 }
308
309 return 0;
310}
311
312/*
313 * validate_region_size
314 * @rs
315 * @region_size: region size in sectors. If 0, pick a size (4MiB default).
316 *
317 * Set rs->md.bitmap_info.chunksize (which really refers to 'region size').
318 * Ensure that (ti->len/region_size < 2^21) - required by MD bitmap.
319 *
320 * Returns: 0 on success, -EINVAL on failure.
321 */
322static int validate_region_size(struct raid_set *rs, unsigned long region_size)
323{
324 unsigned long min_region_size = rs->ti->len / (1 << 21);
325
326 if (!region_size) {
327 /*
328 * Choose a reasonable default. All figures in sectors.
329 */
330 if (min_region_size > (1 << 13)) {
331 /* If not a power of 2, make it the next power of 2 */
332 region_size = roundup_pow_of_two(min_region_size);
333 DMINFO("Choosing default region size of %lu sectors",
334 region_size);
335 } else {
336 DMINFO("Choosing default region size of 4MiB");
337 region_size = 1 << 13; /* sectors */
338 }
339 } else {
340 /*
341 * Validate user-supplied value.
342 */
343 if (region_size > rs->ti->len) {
344 rs->ti->error = "Supplied region size is too large";
345 return -EINVAL;
346 }
347
348 if (region_size < min_region_size) {
349 DMERR("Supplied region_size (%lu sectors) below minimum (%lu)",
350 region_size, min_region_size);
351 rs->ti->error = "Supplied region size is too small";
352 return -EINVAL;
353 }
354
355 if (!is_power_of_2(region_size)) {
356 rs->ti->error = "Region size is not a power of 2";
357 return -EINVAL;
358 }
359
360 if (region_size < rs->md.chunk_sectors) {
361 rs->ti->error = "Region size is smaller than the chunk size";
362 return -EINVAL;
363 }
364 }
365
366 /*
367 * Convert sectors to bytes.
368 */
369 rs->md.bitmap_info.chunksize = (region_size << 9);
370
371 return 0;
372}
373
374/*
375 * validate_raid_redundancy
376 * @rs
377 *
378 * Determine if there are enough devices in the array that haven't
379 * failed (or are being rebuilt) to form a usable array.
380 *
381 * Returns: 0 on success, -EINVAL on failure.
382 */
383static int validate_raid_redundancy(struct raid_set *rs)
384{
385 unsigned i, rebuild_cnt = 0;
386 unsigned rebuilds_per_group = 0, copies, d;
387 unsigned group_size, last_group_start;
388
389 for (i = 0; i < rs->md.raid_disks; i++)
390 if (!test_bit(In_sync, &rs->dev[i].rdev.flags) ||
391 !rs->dev[i].rdev.sb_page)
392 rebuild_cnt++;
393
394 switch (rs->raid_type->level) {
395 case 1:
396 if (rebuild_cnt >= rs->md.raid_disks)
397 goto too_many;
398 break;
399 case 4:
400 case 5:
401 case 6:
402 if (rebuild_cnt > rs->raid_type->parity_devs)
403 goto too_many;
404 break;
405 case 10:
406 copies = raid10_md_layout_to_copies(rs->md.layout);
407 if (rebuild_cnt < copies)
408 break;
409
410 /*
411 * It is possible to have a higher rebuild count for RAID10,
412 * as long as the failed devices occur in different mirror
413 * groups (i.e. different stripes).
414 *
415 * When checking "near" format, make sure no adjacent devices
416 * have failed beyond what can be handled. In addition to the
417 * simple case where the number of devices is a multiple of the
418 * number of copies, we must also handle cases where the number
419 * of devices is not a multiple of the number of copies.
420 * E.g. dev1 dev2 dev3 dev4 dev5
421 * A A B B C
422 * C D D E E
423 */
424 if (!strcmp("near", raid10_md_layout_to_format(rs->md.layout))) {
425 for (i = 0; i < rs->md.raid_disks * copies; i++) {
426 if (!(i % copies))
427 rebuilds_per_group = 0;
428 d = i % rs->md.raid_disks;
429 if ((!rs->dev[d].rdev.sb_page ||
430 !test_bit(In_sync, &rs->dev[d].rdev.flags)) &&
431 (++rebuilds_per_group >= copies))
432 goto too_many;
433 }
434 break;
435 }
436
437 /*
438 * When checking "far" and "offset" formats, we need to ensure
439 * that the device that holds its copy is not also dead or
440 * being rebuilt. (Note that "far" and "offset" formats only
441 * support two copies right now. These formats also only ever
442 * use the 'use_far_sets' variant.)
443 *
444 * This check is somewhat complicated by the need to account
445 * for arrays that are not a multiple of (far) copies. This
446 * results in the need to treat the last (potentially larger)
447 * set differently.
448 */
449 group_size = (rs->md.raid_disks / copies);
450 last_group_start = (rs->md.raid_disks / group_size) - 1;
451 last_group_start *= group_size;
452 for (i = 0; i < rs->md.raid_disks; i++) {
453 if (!(i % copies) && !(i > last_group_start))
454 rebuilds_per_group = 0;
455 if ((!rs->dev[i].rdev.sb_page ||
456 !test_bit(In_sync, &rs->dev[i].rdev.flags)) &&
457 (++rebuilds_per_group >= copies))
458 goto too_many;
459 }
460 break;
461 default:
462 if (rebuild_cnt)
463 return -EINVAL;
464 }
465
466 return 0;
467
468too_many:
469 return -EINVAL;
470}
471
472/*
473 * Possible arguments are...
474 * <chunk_size> [optional_args]
475 *
476 * Argument definitions
477 * <chunk_size> The number of sectors per disk that
478 * will form the "stripe"
479 * [[no]sync] Force or prevent recovery of the
480 * entire array
481 * [rebuild <idx>] Rebuild the drive indicated by the index
482 * [daemon_sleep <ms>] Time between bitmap daemon work to
483 * clear bits
484 * [min_recovery_rate <kB/sec/disk>] Throttle RAID initialization
485 * [max_recovery_rate <kB/sec/disk>] Throttle RAID initialization
486 * [write_mostly <idx>] Indicate a write mostly drive via index
487 * [max_write_behind <sectors>] See '-write-behind=' (man mdadm)
488 * [stripe_cache <sectors>] Stripe cache size for higher RAIDs
489 * [region_size <sectors>] Defines granularity of bitmap
490 *
491 * RAID10-only options:
492 * [raid10_copies <# copies>] Number of copies. (Default: 2)
493 * [raid10_format <near|far|offset>] Layout algorithm. (Default: near)
494 */
495static int parse_raid_params(struct raid_set *rs, char **argv,
496 unsigned num_raid_params)
497{
498 char *raid10_format = "near";
499 unsigned raid10_copies = 2;
500 unsigned i;
501 unsigned long value, region_size = 0;
502 sector_t sectors_per_dev = rs->ti->len;
503 sector_t max_io_len;
504 char *key;
505
506 /*
507 * First, parse the in-order required arguments
508 * "chunk_size" is the only argument of this type.
509 */
510 if ((kstrtoul(argv[0], 10, &value) < 0)) {
511 rs->ti->error = "Bad chunk size";
512 return -EINVAL;
513 } else if (rs->raid_type->level == 1) {
514 if (value)
515 DMERR("Ignoring chunk size parameter for RAID 1");
516 value = 0;
517 } else if (!is_power_of_2(value)) {
518 rs->ti->error = "Chunk size must be a power of 2";
519 return -EINVAL;
520 } else if (value < 8) {
521 rs->ti->error = "Chunk size value is too small";
522 return -EINVAL;
523 }
524
525 rs->md.new_chunk_sectors = rs->md.chunk_sectors = value;
526 argv++;
527 num_raid_params--;
528
529 /*
530 * We set each individual device as In_sync with a completed
531 * 'recovery_offset'. If there has been a device failure or
532 * replacement then one of the following cases applies:
533 *
534 * 1) User specifies 'rebuild'.
535 * - Device is reset when param is read.
536 * 2) A new device is supplied.
537 * - No matching superblock found, resets device.
538 * 3) Device failure was transient and returns on reload.
539 * - Failure noticed, resets device for bitmap replay.
540 * 4) Device hadn't completed recovery after previous failure.
541 * - Superblock is read and overrides recovery_offset.
542 *
543 * What is found in the superblocks of the devices is always
544 * authoritative, unless 'rebuild' or '[no]sync' was specified.
545 */
546 for (i = 0; i < rs->md.raid_disks; i++) {
547 set_bit(In_sync, &rs->dev[i].rdev.flags);
548 rs->dev[i].rdev.recovery_offset = MaxSector;
549 }
550
551 /*
552 * Second, parse the unordered optional arguments
553 */
554 for (i = 0; i < num_raid_params; i++) {
555 if (!strcasecmp(argv[i], "nosync")) {
556 rs->md.recovery_cp = MaxSector;
557 rs->ctr_flags |= CTR_FLAG_NOSYNC;
558 continue;
559 }
560 if (!strcasecmp(argv[i], "sync")) {
561 rs->md.recovery_cp = 0;
562 rs->ctr_flags |= CTR_FLAG_SYNC;
563 continue;
564 }
565
566 /* The rest of the optional arguments come in key/value pairs */
567 if ((i + 1) >= num_raid_params) {
568 rs->ti->error = "Wrong number of raid parameters given";
569 return -EINVAL;
570 }
571
572 key = argv[i++];
573
574 /* Parameters that take a string value are checked here. */
575 if (!strcasecmp(key, "raid10_format")) {
576 if (rs->raid_type->level != 10) {
577 rs->ti->error = "'raid10_format' is an invalid parameter for this RAID type";
578 return -EINVAL;
579 }
580 if (strcmp("near", argv[i]) &&
581 strcmp("far", argv[i]) &&
582 strcmp("offset", argv[i])) {
583 rs->ti->error = "Invalid 'raid10_format' value given";
584 return -EINVAL;
585 }
586 raid10_format = argv[i];
587 rs->ctr_flags |= CTR_FLAG_RAID10_FORMAT;
588 continue;
589 }
590
591 if (kstrtoul(argv[i], 10, &value) < 0) {
592 rs->ti->error = "Bad numerical argument given in raid params";
593 return -EINVAL;
594 }
595
596 /* Parameters that take a numeric value are checked here */
597 if (!strcasecmp(key, "rebuild")) {
598 if (value >= rs->md.raid_disks) {
599 rs->ti->error = "Invalid rebuild index given";
600 return -EINVAL;
601 }
602 clear_bit(In_sync, &rs->dev[value].rdev.flags);
603 rs->dev[value].rdev.recovery_offset = 0;
604 rs->ctr_flags |= CTR_FLAG_REBUILD;
605 } else if (!strcasecmp(key, "write_mostly")) {
606 if (rs->raid_type->level != 1) {
607 rs->ti->error = "write_mostly option is only valid for RAID1";
608 return -EINVAL;
609 }
610 if (value >= rs->md.raid_disks) {
611 rs->ti->error = "Invalid write_mostly drive index given";
612 return -EINVAL;
613 }
614 set_bit(WriteMostly, &rs->dev[value].rdev.flags);
615 } else if (!strcasecmp(key, "max_write_behind")) {
616 if (rs->raid_type->level != 1) {
617 rs->ti->error = "max_write_behind option is only valid for RAID1";
618 return -EINVAL;
619 }
620 rs->ctr_flags |= CTR_FLAG_MAX_WRITE_BEHIND;
621
622 /*
623 * In device-mapper, we specify things in sectors, but
624 * MD records this value in kB
625 */
626 value /= 2;
627 if (value > COUNTER_MAX) {
628 rs->ti->error = "Max write-behind limit out of range";
629 return -EINVAL;
630 }
631 rs->md.bitmap_info.max_write_behind = value;
632 } else if (!strcasecmp(key, "daemon_sleep")) {
633 rs->ctr_flags |= CTR_FLAG_DAEMON_SLEEP;
634 if (!value || (value > MAX_SCHEDULE_TIMEOUT)) {
635 rs->ti->error = "daemon sleep period out of range";
636 return -EINVAL;
637 }
638 rs->md.bitmap_info.daemon_sleep = value;
639 } else if (!strcasecmp(key, "stripe_cache")) {
640 rs->ctr_flags |= CTR_FLAG_STRIPE_CACHE;
641
642 /*
643 * In device-mapper, we specify things in sectors, but
644 * MD records this value in kB
645 */
646 value /= 2;
647
648 if ((rs->raid_type->level != 5) &&
649 (rs->raid_type->level != 6)) {
650 rs->ti->error = "Inappropriate argument: stripe_cache";
651 return -EINVAL;
652 }
653 if (raid5_set_cache_size(&rs->md, (int)value)) {
654 rs->ti->error = "Bad stripe_cache size";
655 return -EINVAL;
656 }
657 } else if (!strcasecmp(key, "min_recovery_rate")) {
658 rs->ctr_flags |= CTR_FLAG_MIN_RECOVERY_RATE;
659 if (value > INT_MAX) {
660 rs->ti->error = "min_recovery_rate out of range";
661 return -EINVAL;
662 }
663 rs->md.sync_speed_min = (int)value;
664 } else if (!strcasecmp(key, "max_recovery_rate")) {
665 rs->ctr_flags |= CTR_FLAG_MAX_RECOVERY_RATE;
666 if (value > INT_MAX) {
667 rs->ti->error = "max_recovery_rate out of range";
668 return -EINVAL;
669 }
670 rs->md.sync_speed_max = (int)value;
671 } else if (!strcasecmp(key, "region_size")) {
672 rs->ctr_flags |= CTR_FLAG_REGION_SIZE;
673 region_size = value;
674 } else if (!strcasecmp(key, "raid10_copies") &&
675 (rs->raid_type->level == 10)) {
676 if ((value < 2) || (value > 0xFF)) {
677 rs->ti->error = "Bad value for 'raid10_copies'";
678 return -EINVAL;
679 }
680 rs->ctr_flags |= CTR_FLAG_RAID10_COPIES;
681 raid10_copies = value;
682 } else {
683 DMERR("Unable to parse RAID parameter: %s", key);
684 rs->ti->error = "Unable to parse RAID parameters";
685 return -EINVAL;
686 }
687 }
688
689 if (validate_region_size(rs, region_size))
690 return -EINVAL;
691
692 if (rs->md.chunk_sectors)
693 max_io_len = rs->md.chunk_sectors;
694 else
695 max_io_len = region_size;
696
697 if (dm_set_target_max_io_len(rs->ti, max_io_len))
698 return -EINVAL;
699
700 if (rs->raid_type->level == 10) {
701 if (raid10_copies > rs->md.raid_disks) {
702 rs->ti->error = "Not enough devices to satisfy specification";
703 return -EINVAL;
704 }
705
706 /*
707 * If the format is not "near", we only support
708 * two copies at the moment.
709 */
710 if (strcmp("near", raid10_format) && (raid10_copies > 2)) {
711 rs->ti->error = "Too many copies for given RAID10 format.";
712 return -EINVAL;
713 }
714
715 /* (Len * #mirrors) / #devices */
716 sectors_per_dev = rs->ti->len * raid10_copies;
717 sector_div(sectors_per_dev, rs->md.raid_disks);
718
719 rs->md.layout = raid10_format_to_md_layout(raid10_format,
720 raid10_copies);
721 rs->md.new_layout = rs->md.layout;
722 } else if ((!rs->raid_type->level || rs->raid_type->level > 1) &&
723 sector_div(sectors_per_dev,
724 (rs->md.raid_disks - rs->raid_type->parity_devs))) {
725 rs->ti->error = "Target length not divisible by number of data devices";
726 return -EINVAL;
727 }
728 rs->md.dev_sectors = sectors_per_dev;
729
730 /* Assume there are no metadata devices until the drives are parsed */
731 rs->md.persistent = 0;
732 rs->md.external = 1;
733
734 return 0;
735}
736
737static void do_table_event(struct work_struct *ws)
738{
739 struct raid_set *rs = container_of(ws, struct raid_set, md.event_work);
740
741 dm_table_event(rs->ti->table);
742}
743
744static int raid_is_congested(struct dm_target_callbacks *cb, int bits)
745{
746 struct raid_set *rs = container_of(cb, struct raid_set, callbacks);
747
748 return mddev_congested(&rs->md, bits);
749}
750
751/*
752 * This structure is never routinely used by userspace, unlike md superblocks.
753 * Devices with this superblock should only ever be accessed via device-mapper.
754 */
755#define DM_RAID_MAGIC 0x64526D44
756struct dm_raid_superblock {
757 __le32 magic; /* "DmRd" */
758 __le32 features; /* Used to indicate possible future changes */
759
760 __le32 num_devices; /* Number of devices in this array. (Max 64) */
761 __le32 array_position; /* The position of this drive in the array */
762
763 __le64 events; /* Incremented by md when superblock updated */
764 __le64 failed_devices; /* Bit field of devices to indicate failures */
765
766 /*
767 * This offset tracks the progress of the repair or replacement of
768 * an individual drive.
769 */
770 __le64 disk_recovery_offset;
771
772 /*
773 * This offset tracks the progress of the initial array
774 * synchronisation/parity calculation.
775 */
776 __le64 array_resync_offset;
777
778 /*
779 * RAID characteristics
780 */
781 __le32 level;
782 __le32 layout;
783 __le32 stripe_sectors;
784
785 /* Remainder of a logical block is zero-filled when writing (see super_sync()). */
786} __packed;
787
788static int read_disk_sb(struct md_rdev *rdev, int size)
789{
790 BUG_ON(!rdev->sb_page);
791
792 if (rdev->sb_loaded)
793 return 0;
794
795 if (!sync_page_io(rdev, 0, size, rdev->sb_page, READ, 1)) {
796 DMERR("Failed to read superblock of device at position %d",
797 rdev->raid_disk);
798 md_error(rdev->mddev, rdev);
799 return -EINVAL;
800 }
801
802 rdev->sb_loaded = 1;
803
804 return 0;
805}
806
807static void super_sync(struct mddev *mddev, struct md_rdev *rdev)
808{
809 int i;
810 uint64_t failed_devices;
811 struct dm_raid_superblock *sb;
812 struct raid_set *rs = container_of(mddev, struct raid_set, md);
813
814 sb = page_address(rdev->sb_page);
815 failed_devices = le64_to_cpu(sb->failed_devices);
816
817 for (i = 0; i < mddev->raid_disks; i++)
818 if (!rs->dev[i].data_dev ||
819 test_bit(Faulty, &(rs->dev[i].rdev.flags)))
820 failed_devices |= (1ULL << i);
821
822 memset(sb + 1, 0, rdev->sb_size - sizeof(*sb));
823
824 sb->magic = cpu_to_le32(DM_RAID_MAGIC);
825 sb->features = cpu_to_le32(0); /* No features yet */
826
827 sb->num_devices = cpu_to_le32(mddev->raid_disks);
828 sb->array_position = cpu_to_le32(rdev->raid_disk);
829
830 sb->events = cpu_to_le64(mddev->events);
831 sb->failed_devices = cpu_to_le64(failed_devices);
832
833 sb->disk_recovery_offset = cpu_to_le64(rdev->recovery_offset);
834 sb->array_resync_offset = cpu_to_le64(mddev->recovery_cp);
835
836 sb->level = cpu_to_le32(mddev->level);
837 sb->layout = cpu_to_le32(mddev->layout);
838 sb->stripe_sectors = cpu_to_le32(mddev->chunk_sectors);
839}
840
841/*
842 * super_load
843 *
844 * This function creates a superblock if one is not found on the device
845 * and will decide which superblock to use if there's a choice.
846 *
847 * Return: 1 if use rdev, 0 if use refdev, -Exxx otherwise
848 */
849static int super_load(struct md_rdev *rdev, struct md_rdev *refdev)
850{
851 int ret;
852 struct dm_raid_superblock *sb;
853 struct dm_raid_superblock *refsb;
854 uint64_t events_sb, events_refsb;
855
856 rdev->sb_start = 0;
857 rdev->sb_size = bdev_logical_block_size(rdev->meta_bdev);
858 if (rdev->sb_size < sizeof(*sb) || rdev->sb_size > PAGE_SIZE) {
859 DMERR("superblock size of a logical block is no longer valid");
860 return -EINVAL;
861 }
862
863 ret = read_disk_sb(rdev, rdev->sb_size);
864 if (ret)
865 return ret;
866
867 sb = page_address(rdev->sb_page);
868
869 /*
870 * Two cases that we want to write new superblocks and rebuild:
871 * 1) New device (no matching magic number)
872 * 2) Device specified for rebuild (!In_sync w/ offset == 0)
873 */
874 if ((sb->magic != cpu_to_le32(DM_RAID_MAGIC)) ||
875 (!test_bit(In_sync, &rdev->flags) && !rdev->recovery_offset)) {
876 super_sync(rdev->mddev, rdev);
877
878 set_bit(FirstUse, &rdev->flags);
879
880 /* Force writing of superblocks to disk */
881 set_bit(MD_CHANGE_DEVS, &rdev->mddev->flags);
882
883 /* Any superblock is better than none, choose that if given */
884 return refdev ? 0 : 1;
885 }
886
887 if (!refdev)
888 return 1;
889
890 events_sb = le64_to_cpu(sb->events);
891
892 refsb = page_address(refdev->sb_page);
893 events_refsb = le64_to_cpu(refsb->events);
894
895 return (events_sb > events_refsb) ? 1 : 0;
896}
897
898static int super_init_validation(struct mddev *mddev, struct md_rdev *rdev)
899{
900 int role;
901 struct raid_set *rs = container_of(mddev, struct raid_set, md);
902 uint64_t events_sb;
903 uint64_t failed_devices;
904 struct dm_raid_superblock *sb;
905 uint32_t new_devs = 0;
906 uint32_t rebuilds = 0;
907 struct md_rdev *r;
908 struct dm_raid_superblock *sb2;
909
910 sb = page_address(rdev->sb_page);
911 events_sb = le64_to_cpu(sb->events);
912 failed_devices = le64_to_cpu(sb->failed_devices);
913
914 /*
915 * Initialise to 1 if this is a new superblock.
916 */
917 mddev->events = events_sb ? : 1;
918
919 /*
920 * Reshaping is not currently allowed
921 */
922 if (le32_to_cpu(sb->level) != mddev->level) {
923 DMERR("Reshaping arrays not yet supported. (RAID level change)");
924 return -EINVAL;
925 }
926 if (le32_to_cpu(sb->layout) != mddev->layout) {
927 DMERR("Reshaping arrays not yet supported. (RAID layout change)");
928 DMERR(" 0x%X vs 0x%X", le32_to_cpu(sb->layout), mddev->layout);
929 DMERR(" Old layout: %s w/ %d copies",
930 raid10_md_layout_to_format(le32_to_cpu(sb->layout)),
931 raid10_md_layout_to_copies(le32_to_cpu(sb->layout)));
932 DMERR(" New layout: %s w/ %d copies",
933 raid10_md_layout_to_format(mddev->layout),
934 raid10_md_layout_to_copies(mddev->layout));
935 return -EINVAL;
936 }
937 if (le32_to_cpu(sb->stripe_sectors) != mddev->chunk_sectors) {
938 DMERR("Reshaping arrays not yet supported. (stripe sectors change)");
939 return -EINVAL;
940 }
941
942 /* We can only change the number of devices in RAID1 right now */
943 if ((rs->raid_type->level != 1) &&
944 (le32_to_cpu(sb->num_devices) != mddev->raid_disks)) {
945 DMERR("Reshaping arrays not yet supported. (device count change)");
946 return -EINVAL;
947 }
948
949 if (!(rs->ctr_flags & (CTR_FLAG_SYNC | CTR_FLAG_NOSYNC)))
950 mddev->recovery_cp = le64_to_cpu(sb->array_resync_offset);
951
952 /*
953 * During load, we set FirstUse if a new superblock was written.
954 * There are two reasons we might not have a superblock:
955 * 1) The array is brand new - in which case, all of the
956 * devices must have their In_sync bit set. Also,
957 * recovery_cp must be 0, unless forced.
958 * 2) This is a new device being added to an old array
959 * and the new device needs to be rebuilt - in which
960 * case the In_sync bit will /not/ be set and
961 * recovery_cp must be MaxSector.
962 */
963 rdev_for_each(r, mddev) {
964 if (!test_bit(In_sync, &r->flags)) {
965 DMINFO("Device %d specified for rebuild: "
966 "Clearing superblock", r->raid_disk);
967 rebuilds++;
968 } else if (test_bit(FirstUse, &r->flags))
969 new_devs++;
970 }
971
972 if (!rebuilds) {
973 if (new_devs == mddev->raid_disks) {
974 DMINFO("Superblocks created for new array");
975 set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
976 } else if (new_devs) {
977 DMERR("New device injected "
978 "into existing array without 'rebuild' "
979 "parameter specified");
980 return -EINVAL;
981 }
982 } else if (new_devs) {
983 DMERR("'rebuild' devices cannot be "
984 "injected into an array with other first-time devices");
985 return -EINVAL;
986 } else if (mddev->recovery_cp != MaxSector) {
987 DMERR("'rebuild' specified while array is not in-sync");
988 return -EINVAL;
989 }
990
991 /*
992 * Now we set the Faulty bit for those devices that are
993 * recorded in the superblock as failed.
994 */
995 rdev_for_each(r, mddev) {
996 if (!r->sb_page)
997 continue;
998 sb2 = page_address(r->sb_page);
999 sb2->failed_devices = 0;
1000
1001 /*
1002 * Check for any device re-ordering.
1003 */
1004 if (!test_bit(FirstUse, &r->flags) && (r->raid_disk >= 0)) {
1005 role = le32_to_cpu(sb2->array_position);
1006 if (role != r->raid_disk) {
1007 if (rs->raid_type->level != 1) {
1008 rs->ti->error = "Cannot change device "
1009 "positions in RAID array";
1010 return -EINVAL;
1011 }
1012 DMINFO("RAID1 device #%d now at position #%d",
1013 role, r->raid_disk);
1014 }
1015
1016 /*
1017 * Partial recovery is performed on
1018 * returning failed devices.
1019 */
1020 if (failed_devices & (1 << role))
1021 set_bit(Faulty, &r->flags);
1022 }
1023 }
1024
1025 return 0;
1026}
1027
1028static int super_validate(struct raid_set *rs, struct md_rdev *rdev)
1029{
1030 struct mddev *mddev = &rs->md;
1031 struct dm_raid_superblock *sb = page_address(rdev->sb_page);
1032
1033 /*
1034 * If mddev->events is not set, we know we have not yet initialized
1035 * the array.
1036 */
1037 if (!mddev->events && super_init_validation(mddev, rdev))
1038 return -EINVAL;
1039
1040 /* Enable bitmap creation for RAID levels != 0 */
1041 mddev->bitmap_info.offset = (rs->raid_type->level) ? to_sector(4096) : 0;
1042 rdev->mddev->bitmap_info.default_offset = mddev->bitmap_info.offset;
1043
1044 if (!test_bit(FirstUse, &rdev->flags)) {
1045 rdev->recovery_offset = le64_to_cpu(sb->disk_recovery_offset);
1046 if (rdev->recovery_offset != MaxSector)
1047 clear_bit(In_sync, &rdev->flags);
1048 }
1049
1050 /*
1051 * If a device comes back, set it as not In_sync and no longer faulty.
1052 */
1053 if (test_bit(Faulty, &rdev->flags)) {
1054 clear_bit(Faulty, &rdev->flags);
1055 clear_bit(In_sync, &rdev->flags);
1056 rdev->saved_raid_disk = rdev->raid_disk;
1057 rdev->recovery_offset = 0;
1058 }
1059
1060 clear_bit(FirstUse, &rdev->flags);
1061
1062 return 0;
1063}
1064
1065/*
1066 * Analyse superblocks and select the freshest.
1067 */
1068static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
1069{
1070 int ret;
1071 struct raid_dev *dev;
1072 struct md_rdev *rdev, *tmp, *freshest;
1073 struct mddev *mddev = &rs->md;
1074
1075 freshest = NULL;
1076 rdev_for_each_safe(rdev, tmp, mddev) {
1077 /*
1078 * Skipping super_load due to CTR_FLAG_SYNC will cause
1079 * the array to undergo initialization again as
1080 * though it were new. This is the intended effect
1081 * of the "sync" directive.
1082 *
1083 * When reshaping capability is added, we must ensure
1084 * that the "sync" directive is disallowed during the
1085 * reshape.
1086 */
1087 rdev->sectors = to_sector(i_size_read(rdev->bdev->bd_inode));
1088
1089 if (rs->ctr_flags & CTR_FLAG_SYNC)
1090 continue;
1091
1092 if (!rdev->meta_bdev)
1093 continue;
1094
1095 ret = super_load(rdev, freshest);
1096
1097 switch (ret) {
1098 case 1:
1099 freshest = rdev;
1100 break;
1101 case 0:
1102 break;
1103 default:
1104 dev = container_of(rdev, struct raid_dev, rdev);
1105 if (dev->meta_dev)
1106 dm_put_device(ti, dev->meta_dev);
1107
1108 dev->meta_dev = NULL;
1109 rdev->meta_bdev = NULL;
1110
1111 if (rdev->sb_page)
1112 put_page(rdev->sb_page);
1113
1114 rdev->sb_page = NULL;
1115
1116 rdev->sb_loaded = 0;
1117
1118 /*
1119 * We might be able to salvage the data device
1120 * even though the meta device has failed. For
1121 * now, we behave as though '- -' had been
1122 * set for this device in the table.
1123 */
1124 if (dev->data_dev)
1125 dm_put_device(ti, dev->data_dev);
1126
1127 dev->data_dev = NULL;
1128 rdev->bdev = NULL;
1129
1130 list_del(&rdev->same_set);
1131 }
1132 }
1133
1134 if (!freshest)
1135 return 0;
1136
1137 if (validate_raid_redundancy(rs)) {
1138 rs->ti->error = "Insufficient redundancy to activate array";
1139 return -EINVAL;
1140 }
1141
1142 /*
1143 * Validation of the freshest device provides the source of
1144 * validation for the remaining devices.
1145 */
1146 ti->error = "Unable to assemble array: Invalid superblocks";
1147 if (super_validate(rs, freshest))
1148 return -EINVAL;
1149
1150 rdev_for_each(rdev, mddev)
1151 if ((rdev != freshest) && super_validate(rs, rdev))
1152 return -EINVAL;
1153
1154 return 0;
1155}
1156
1157/*
1158 * Enable/disable discard support on RAID set depending on
1159 * RAID level and discard properties of underlying RAID members.
1160 */
1161static void configure_discard_support(struct dm_target *ti, struct raid_set *rs)
1162{
1163 int i;
1164 bool raid456;
1165
1166 /* Assume discards not supported until after checks below. */
1167 ti->discards_supported = false;
1168
1169 /* RAID level 4,5,6 require discard_zeroes_data for data integrity! */
1170 raid456 = (rs->md.level == 4 || rs->md.level == 5 || rs->md.level == 6);
1171
1172 for (i = 0; i < rs->md.raid_disks; i++) {
1173 struct request_queue *q;
1174
1175 if (!rs->dev[i].rdev.bdev)
1176 continue;
1177
1178 q = bdev_get_queue(rs->dev[i].rdev.bdev);
1179 if (!q || !blk_queue_discard(q))
1180 return;
1181
1182 if (raid456) {
1183 if (!q->limits.discard_zeroes_data)
1184 return;
1185 if (!devices_handle_discard_safely) {
1186 DMERR("raid456 discard support disabled due to discard_zeroes_data uncertainty.");
1187 DMERR("Set dm-raid.devices_handle_discard_safely=Y to override.");
1188 return;
1189 }
1190 }
1191 }
1192
1193 /* All RAID members properly support discards */
1194 ti->discards_supported = true;
1195
1196 /*
1197 * RAID1 and RAID10 personalities require bio splitting,
1198 * RAID0/4/5/6 don't and process large discard bios properly.
1199 */
1200 ti->split_discard_bios = !!(rs->md.level == 1 || rs->md.level == 10);
1201 ti->num_discard_bios = 1;
1202}
1203
1204/*
1205 * Construct a RAID4/5/6 mapping:
1206 * Args:
1207 * <raid_type> <#raid_params> <raid_params> \
1208 * <#raid_devs> { <meta_dev1> <dev1> .. <meta_devN> <devN> }
1209 *
1210 * <raid_params> varies by <raid_type>. See 'parse_raid_params' for
1211 * details on possible <raid_params>.
1212 */
1213static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
1214{
1215 int ret;
1216 struct raid_type *rt;
1217 unsigned long num_raid_params, num_raid_devs;
1218 struct raid_set *rs = NULL;
1219
1220 /* Must have at least <raid_type> <#raid_params> */
1221 if (argc < 2) {
1222 ti->error = "Too few arguments";
1223 return -EINVAL;
1224 }
1225
1226 /* raid type */
1227 rt = get_raid_type(argv[0]);
1228 if (!rt) {
1229 ti->error = "Unrecognised raid_type";
1230 return -EINVAL;
1231 }
1232 argc--;
1233 argv++;
1234
1235 /* number of RAID parameters */
1236 if (kstrtoul(argv[0], 10, &num_raid_params) < 0) {
1237 ti->error = "Cannot understand number of RAID parameters";
1238 return -EINVAL;
1239 }
1240 argc--;
1241 argv++;
1242
1243 /* Skip over RAID params for now and find out # of devices */
1244 if (num_raid_params >= argc) {
1245 ti->error = "Arguments do not agree with counts given";
1246 return -EINVAL;
1247 }
1248
1249 if ((kstrtoul(argv[num_raid_params], 10, &num_raid_devs) < 0) ||
1250 (num_raid_devs > MAX_RAID_DEVICES)) {
1251 ti->error = "Cannot understand number of raid devices";
1252 return -EINVAL;
1253 }
1254
1255 argc -= num_raid_params + 1; /* +1: we already have num_raid_devs */
1256 if (argc != (num_raid_devs * 2)) {
1257 ti->error = "Supplied RAID devices does not match the count given";
1258 return -EINVAL;
1259 }
1260
1261 rs = context_alloc(ti, rt, (unsigned)num_raid_devs);
1262 if (IS_ERR(rs))
1263 return PTR_ERR(rs);
1264
1265 ret = parse_raid_params(rs, argv, (unsigned)num_raid_params);
1266 if (ret)
1267 goto bad;
1268
1269 argv += num_raid_params + 1;
1270
1271 ret = dev_parms(rs, argv);
1272 if (ret)
1273 goto bad;
1274
1275 rs->md.sync_super = super_sync;
1276 ret = analyse_superblocks(ti, rs);
1277 if (ret)
1278 goto bad;
1279
1280 INIT_WORK(&rs->md.event_work, do_table_event);
1281 ti->private = rs;
1282 ti->num_flush_bios = 1;
1283
1284 /*
1285 * Disable/enable discard support on RAID set.
1286 */
1287 configure_discard_support(ti, rs);
1288
1289 /* Has to be held on running the array */
1290 mddev_lock_nointr(&rs->md);
1291 ret = md_run(&rs->md);
1292 rs->md.in_sync = 0; /* Assume already marked dirty */
1293 mddev_unlock(&rs->md);
1294
1295 if (ret) {
1296 ti->error = "Fail to run raid array";
1297 goto bad;
1298 }
1299
1300 if (ti->len != rs->md.array_sectors) {
1301 ti->error = "Array size does not match requested target length";
1302 ret = -EINVAL;
1303 goto size_mismatch;
1304 }
1305 rs->callbacks.congested_fn = raid_is_congested;
1306 dm_table_add_target_callbacks(ti->table, &rs->callbacks);
1307
1308 mddev_suspend(&rs->md);
1309 return 0;
1310
1311size_mismatch:
1312 md_stop(&rs->md);
1313bad:
1314 context_free(rs);
1315
1316 return ret;
1317}
1318
1319static void raid_dtr(struct dm_target *ti)
1320{
1321 struct raid_set *rs = ti->private;
1322
1323 list_del_init(&rs->callbacks.list);
1324 md_stop(&rs->md);
1325 context_free(rs);
1326}
1327
1328static int raid_map(struct dm_target *ti, struct bio *bio)
1329{
1330 struct raid_set *rs = ti->private;
1331 struct mddev *mddev = &rs->md;
1332
1333 mddev->pers->make_request(mddev, bio);
1334
1335 return DM_MAPIO_SUBMITTED;
1336}
1337
1338static const char *decipher_sync_action(struct mddev *mddev)
1339{
1340 if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
1341 return "frozen";
1342
1343 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
1344 (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))) {
1345 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
1346 return "reshape";
1347
1348 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
1349 if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
1350 return "resync";
1351 else if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
1352 return "check";
1353 return "repair";
1354 }
1355
1356 if (test_bit(MD_RECOVERY_RECOVER, &mddev->recovery))
1357 return "recover";
1358 }
1359
1360 return "idle";
1361}
1362
1363static void raid_status(struct dm_target *ti, status_type_t type,
1364 unsigned status_flags, char *result, unsigned maxlen)
1365{
1366 struct raid_set *rs = ti->private;
1367 unsigned raid_param_cnt = 1; /* at least 1 for chunksize */
1368 unsigned sz = 0;
1369 int i, array_in_sync = 0;
1370 sector_t sync;
1371
1372 switch (type) {
1373 case STATUSTYPE_INFO:
1374 DMEMIT("%s %d ", rs->raid_type->name, rs->md.raid_disks);
1375
1376 if (rs->raid_type->level) {
1377 if (test_bit(MD_RECOVERY_RUNNING, &rs->md.recovery))
1378 sync = rs->md.curr_resync_completed;
1379 else
1380 sync = rs->md.recovery_cp;
1381
1382 if (sync >= rs->md.resync_max_sectors) {
1383 /*
1384 * Sync complete.
1385 */
1386 array_in_sync = 1;
1387 sync = rs->md.resync_max_sectors;
1388 } else if (test_bit(MD_RECOVERY_REQUESTED, &rs->md.recovery)) {
1389 /*
1390 * If "check" or "repair" is occurring, the array has
1391 * undergone and initial sync and the health characters
1392 * should not be 'a' anymore.
1393 */
1394 array_in_sync = 1;
1395 } else {
1396 /*
1397 * The array may be doing an initial sync, or it may
1398 * be rebuilding individual components. If all the
1399 * devices are In_sync, then it is the array that is
1400 * being initialized.
1401 */
1402 for (i = 0; i < rs->md.raid_disks; i++)
1403 if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
1404 array_in_sync = 1;
1405 }
1406 } else {
1407 /* RAID0 */
1408 array_in_sync = 1;
1409 sync = rs->md.resync_max_sectors;
1410 }
1411
1412 /*
1413 * Status characters:
1414 * 'D' = Dead/Failed device
1415 * 'a' = Alive but not in-sync
1416 * 'A' = Alive and in-sync
1417 */
1418 for (i = 0; i < rs->md.raid_disks; i++) {
1419 if (test_bit(Faulty, &rs->dev[i].rdev.flags))
1420 DMEMIT("D");
1421 else if (!array_in_sync ||
1422 !test_bit(In_sync, &rs->dev[i].rdev.flags))
1423 DMEMIT("a");
1424 else
1425 DMEMIT("A");
1426 }
1427
1428 /*
1429 * In-sync ratio:
1430 * The in-sync ratio shows the progress of:
1431 * - Initializing the array
1432 * - Rebuilding a subset of devices of the array
1433 * The user can distinguish between the two by referring
1434 * to the status characters.
1435 */
1436 DMEMIT(" %llu/%llu",
1437 (unsigned long long) sync,
1438 (unsigned long long) rs->md.resync_max_sectors);
1439
1440 /*
1441 * Sync action:
1442 * See Documentation/device-mapper/dm-raid.c for
1443 * information on each of these states.
1444 */
1445 DMEMIT(" %s", decipher_sync_action(&rs->md));
1446
1447 /*
1448 * resync_mismatches/mismatch_cnt
1449 * This field shows the number of discrepancies found when
1450 * performing a "check" of the array.
1451 */
1452 DMEMIT(" %llu",
1453 (strcmp(rs->md.last_sync_action, "check")) ? 0 :
1454 (unsigned long long)
1455 atomic64_read(&rs->md.resync_mismatches));
1456 break;
1457 case STATUSTYPE_TABLE:
1458 /* The string you would use to construct this array */
1459 for (i = 0; i < rs->md.raid_disks; i++) {
1460 if ((rs->ctr_flags & CTR_FLAG_REBUILD) &&
1461 rs->dev[i].data_dev &&
1462 !test_bit(In_sync, &rs->dev[i].rdev.flags))
1463 raid_param_cnt += 2; /* for rebuilds */
1464 if (rs->dev[i].data_dev &&
1465 test_bit(WriteMostly, &rs->dev[i].rdev.flags))
1466 raid_param_cnt += 2;
1467 }
1468
1469 raid_param_cnt += (hweight32(rs->ctr_flags & ~CTR_FLAG_REBUILD) * 2);
1470 if (rs->ctr_flags & (CTR_FLAG_SYNC | CTR_FLAG_NOSYNC))
1471 raid_param_cnt--;
1472
1473 DMEMIT("%s %u %u", rs->raid_type->name,
1474 raid_param_cnt, rs->md.chunk_sectors);
1475
1476 if ((rs->ctr_flags & CTR_FLAG_SYNC) &&
1477 (rs->md.recovery_cp == MaxSector))
1478 DMEMIT(" sync");
1479 if (rs->ctr_flags & CTR_FLAG_NOSYNC)
1480 DMEMIT(" nosync");
1481
1482 for (i = 0; i < rs->md.raid_disks; i++)
1483 if ((rs->ctr_flags & CTR_FLAG_REBUILD) &&
1484 rs->dev[i].data_dev &&
1485 !test_bit(In_sync, &rs->dev[i].rdev.flags))
1486 DMEMIT(" rebuild %u", i);
1487
1488 if (rs->ctr_flags & CTR_FLAG_DAEMON_SLEEP)
1489 DMEMIT(" daemon_sleep %lu",
1490 rs->md.bitmap_info.daemon_sleep);
1491
1492 if (rs->ctr_flags & CTR_FLAG_MIN_RECOVERY_RATE)
1493 DMEMIT(" min_recovery_rate %d", rs->md.sync_speed_min);
1494
1495 if (rs->ctr_flags & CTR_FLAG_MAX_RECOVERY_RATE)
1496 DMEMIT(" max_recovery_rate %d", rs->md.sync_speed_max);
1497
1498 for (i = 0; i < rs->md.raid_disks; i++)
1499 if (rs->dev[i].data_dev &&
1500 test_bit(WriteMostly, &rs->dev[i].rdev.flags))
1501 DMEMIT(" write_mostly %u", i);
1502
1503 if (rs->ctr_flags & CTR_FLAG_MAX_WRITE_BEHIND)
1504 DMEMIT(" max_write_behind %lu",
1505 rs->md.bitmap_info.max_write_behind);
1506
1507 if (rs->ctr_flags & CTR_FLAG_STRIPE_CACHE) {
1508 struct r5conf *conf = rs->md.private;
1509
1510 /* convert from kiB to sectors */
1511 DMEMIT(" stripe_cache %d",
1512 conf ? conf->max_nr_stripes * 2 : 0);
1513 }
1514
1515 if (rs->ctr_flags & CTR_FLAG_REGION_SIZE)
1516 DMEMIT(" region_size %lu",
1517 rs->md.bitmap_info.chunksize >> 9);
1518
1519 if (rs->ctr_flags & CTR_FLAG_RAID10_COPIES)
1520 DMEMIT(" raid10_copies %u",
1521 raid10_md_layout_to_copies(rs->md.layout));
1522
1523 if (rs->ctr_flags & CTR_FLAG_RAID10_FORMAT)
1524 DMEMIT(" raid10_format %s",
1525 raid10_md_layout_to_format(rs->md.layout));
1526
1527 DMEMIT(" %d", rs->md.raid_disks);
1528 for (i = 0; i < rs->md.raid_disks; i++) {
1529 if (rs->dev[i].meta_dev)
1530 DMEMIT(" %s", rs->dev[i].meta_dev->name);
1531 else
1532 DMEMIT(" -");
1533
1534 if (rs->dev[i].data_dev)
1535 DMEMIT(" %s", rs->dev[i].data_dev->name);
1536 else
1537 DMEMIT(" -");
1538 }
1539 }
1540}
1541
1542static int raid_message(struct dm_target *ti, unsigned argc, char **argv)
1543{
1544 struct raid_set *rs = ti->private;
1545 struct mddev *mddev = &rs->md;
1546
1547 if (!strcasecmp(argv[0], "reshape")) {
1548 DMERR("Reshape not supported.");
1549 return -EINVAL;
1550 }
1551
1552 if (!mddev->pers || !mddev->pers->sync_request)
1553 return -EINVAL;
1554
1555 if (!strcasecmp(argv[0], "frozen"))
1556 set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
1557 else
1558 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
1559
1560 if (!strcasecmp(argv[0], "idle") || !strcasecmp(argv[0], "frozen")) {
1561 if (mddev->sync_thread) {
1562 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1563 md_reap_sync_thread(mddev);
1564 }
1565 } else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
1566 test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
1567 return -EBUSY;
1568 else if (!strcasecmp(argv[0], "resync"))
1569 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
1570 else if (!strcasecmp(argv[0], "recover")) {
1571 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
1572 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
1573 } else {
1574 if (!strcasecmp(argv[0], "check"))
1575 set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
1576 else if (!!strcasecmp(argv[0], "repair"))
1577 return -EINVAL;
1578 set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
1579 set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
1580 }
1581 if (mddev->ro == 2) {
1582 /* A write to sync_action is enough to justify
1583 * canceling read-auto mode
1584 */
1585 mddev->ro = 0;
1586 if (!mddev->suspended)
1587 md_wakeup_thread(mddev->sync_thread);
1588 }
1589 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
1590 if (!mddev->suspended)
1591 md_wakeup_thread(mddev->thread);
1592
1593 return 0;
1594}
1595
1596static int raid_iterate_devices(struct dm_target *ti,
1597 iterate_devices_callout_fn fn, void *data)
1598{
1599 struct raid_set *rs = ti->private;
1600 unsigned i;
1601 int ret = 0;
1602
1603 for (i = 0; !ret && i < rs->md.raid_disks; i++)
1604 if (rs->dev[i].data_dev)
1605 ret = fn(ti,
1606 rs->dev[i].data_dev,
1607 0, /* No offset on data devs */
1608 rs->md.dev_sectors,
1609 data);
1610
1611 return ret;
1612}
1613
1614static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
1615{
1616 struct raid_set *rs = ti->private;
1617 unsigned chunk_size = rs->md.chunk_sectors << 9;
1618 struct r5conf *conf = rs->md.private;
1619
1620 blk_limits_io_min(limits, chunk_size);
1621 blk_limits_io_opt(limits, chunk_size * (conf->raid_disks - conf->max_degraded));
1622}
1623
1624static void raid_presuspend(struct dm_target *ti)
1625{
1626 struct raid_set *rs = ti->private;
1627
1628 md_stop_writes(&rs->md);
1629}
1630
1631static void raid_postsuspend(struct dm_target *ti)
1632{
1633 struct raid_set *rs = ti->private;
1634
1635 mddev_suspend(&rs->md);
1636}
1637
1638static void attempt_restore_of_faulty_devices(struct raid_set *rs)
1639{
1640 int i;
1641 uint64_t failed_devices, cleared_failed_devices = 0;
1642 unsigned long flags;
1643 struct dm_raid_superblock *sb;
1644 struct md_rdev *r;
1645
1646 for (i = 0; i < rs->md.raid_disks; i++) {
1647 r = &rs->dev[i].rdev;
1648 if (test_bit(Faulty, &r->flags) && r->sb_page &&
1649 sync_page_io(r, 0, r->sb_size, r->sb_page, READ, 1)) {
1650 DMINFO("Faulty %s device #%d has readable super block."
1651 " Attempting to revive it.",
1652 rs->raid_type->name, i);
1653
1654 /*
1655 * Faulty bit may be set, but sometimes the array can
1656 * be suspended before the personalities can respond
1657 * by removing the device from the array (i.e. calling
1658 * 'hot_remove_disk'). If they haven't yet removed
1659 * the failed device, its 'raid_disk' number will be
1660 * '>= 0' - meaning we must call this function
1661 * ourselves.
1662 */
1663 if ((r->raid_disk >= 0) &&
1664 (r->mddev->pers->hot_remove_disk(r->mddev, r) != 0))
1665 /* Failed to revive this device, try next */
1666 continue;
1667
1668 r->raid_disk = i;
1669 r->saved_raid_disk = i;
1670 flags = r->flags;
1671 clear_bit(Faulty, &r->flags);
1672 clear_bit(WriteErrorSeen, &r->flags);
1673 clear_bit(In_sync, &r->flags);
1674 if (r->mddev->pers->hot_add_disk(r->mddev, r)) {
1675 r->raid_disk = -1;
1676 r->saved_raid_disk = -1;
1677 r->flags = flags;
1678 } else {
1679 r->recovery_offset = 0;
1680 cleared_failed_devices |= 1 << i;
1681 }
1682 }
1683 }
1684 if (cleared_failed_devices) {
1685 rdev_for_each(r, &rs->md) {
1686 sb = page_address(r->sb_page);
1687 failed_devices = le64_to_cpu(sb->failed_devices);
1688 failed_devices &= ~cleared_failed_devices;
1689 sb->failed_devices = cpu_to_le64(failed_devices);
1690 }
1691 }
1692}
1693
1694static void raid_resume(struct dm_target *ti)
1695{
1696 struct raid_set *rs = ti->private;
1697
1698 if (rs->raid_type->level) {
1699 set_bit(MD_CHANGE_DEVS, &rs->md.flags);
1700
1701 if (!rs->bitmap_loaded) {
1702 bitmap_load(&rs->md);
1703 rs->bitmap_loaded = 1;
1704 } else {
1705 /*
1706 * A secondary resume while the device is active.
1707 * Take this opportunity to check whether any failed
1708 * devices are reachable again.
1709 */
1710 attempt_restore_of_faulty_devices(rs);
1711 }
1712
1713 clear_bit(MD_RECOVERY_FROZEN, &rs->md.recovery);
1714 }
1715
1716 mddev_resume(&rs->md);
1717}
1718
1719static struct target_type raid_target = {
1720 .name = "raid",
1721 .version = {1, 7, 0},
1722 .module = THIS_MODULE,
1723 .ctr = raid_ctr,
1724 .dtr = raid_dtr,
1725 .map = raid_map,
1726 .status = raid_status,
1727 .message = raid_message,
1728 .iterate_devices = raid_iterate_devices,
1729 .io_hints = raid_io_hints,
1730 .presuspend = raid_presuspend,
1731 .postsuspend = raid_postsuspend,
1732 .resume = raid_resume,
1733};
1734
1735static int __init dm_raid_init(void)
1736{
1737 DMINFO("Loading target version %u.%u.%u",
1738 raid_target.version[0],
1739 raid_target.version[1],
1740 raid_target.version[2]);
1741 return dm_register_target(&raid_target);
1742}
1743
1744static void __exit dm_raid_exit(void)
1745{
1746 dm_unregister_target(&raid_target);
1747}
1748
1749module_init(dm_raid_init);
1750module_exit(dm_raid_exit);
1751
1752module_param(devices_handle_discard_safely, bool, 0644);
1753MODULE_PARM_DESC(devices_handle_discard_safely,
1754 "Set to Y if all devices in each array reliably return zeroes on reads from discarded regions");
1755
1756MODULE_DESCRIPTION(DM_NAME " raid4/5/6 target");
1757MODULE_ALIAS("dm-raid1");
1758MODULE_ALIAS("dm-raid10");
1759MODULE_ALIAS("dm-raid4");
1760MODULE_ALIAS("dm-raid5");
1761MODULE_ALIAS("dm-raid6");
1762MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>");
1763MODULE_LICENSE("GPL");