1 /*
2 * Copyright (C) 2010-2011 Neil Brown
3 * Copyright (C) 2010-2014 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
21 static bool devices_handle_discard_safely = false;
22
23 /*
24 * The following flags are used by dm-raid.c to set up the array state.
25 * They must be cleared before md_run is called.
26 */
27 #define FirstUse 10 /* rdev flag */
28
29 struct raid_dev {
30 /*
31 * Two DM devices, one to hold metadata and one to hold the
32 * actual data/parity. The reason for this is to not confuse
33 * ti->len and give more flexibility in altering size and
34 * characteristics.
35 *
36 * While it is possible for this device to be associated
37 * with a different physical device than the data_dev, it
38 * is intended for it to be the same.
39 * |--------- Physical Device ---------|
40 * |- meta_dev -|------ data_dev ------|
41 */
42 struct dm_dev *meta_dev;
43 struct dm_dev *data_dev;
44 struct md_rdev rdev;
45 };
46
47 /*
48 * Flags for rs->print_flags field.
49 */
50 #define DMPF_SYNC 0x1
51 #define DMPF_NOSYNC 0x2
52 #define DMPF_REBUILD 0x4
53 #define DMPF_DAEMON_SLEEP 0x8
54 #define DMPF_MIN_RECOVERY_RATE 0x10
55 #define DMPF_MAX_RECOVERY_RATE 0x20
56 #define DMPF_MAX_WRITE_BEHIND 0x40
57 #define DMPF_STRIPE_CACHE 0x80
58 #define DMPF_REGION_SIZE 0x100
59 #define DMPF_RAID10_COPIES 0x200
60 #define DMPF_RAID10_FORMAT 0x400
61
62 struct raid_set {
63 struct dm_target *ti;
64
65 uint32_t bitmap_loaded;
66 uint32_t print_flags;
67
68 struct mddev md;
69 struct raid_type *raid_type;
70 struct dm_target_callbacks callbacks;
71
72 struct raid_dev dev[0];
73 };
74
75 /* Supported raid types and properties. */
76 static struct raid_type {
77 const char *name; /* RAID algorithm. */
78 const char *descr; /* Descriptor text for logging. */
79 const unsigned parity_devs; /* # of parity devices. */
80 const unsigned minimal_devs; /* minimal # of devices in set. */
81 const unsigned level; /* RAID level. */
82 const unsigned algorithm; /* RAID algorithm. */
83 } raid_types[] = {
84 {"raid1", "RAID1 (mirroring)", 0, 2, 1, 0 /* NONE */},
85 {"raid10", "RAID10 (striped mirrors)", 0, 2, 10, UINT_MAX /* Varies */},
86 {"raid4", "RAID4 (dedicated parity disk)", 1, 2, 5, ALGORITHM_PARITY_0},
87 {"raid5_la", "RAID5 (left asymmetric)", 1, 2, 5, ALGORITHM_LEFT_ASYMMETRIC},
88 {"raid5_ra", "RAID5 (right asymmetric)", 1, 2, 5, ALGORITHM_RIGHT_ASYMMETRIC},
89 {"raid5_ls", "RAID5 (left symmetric)", 1, 2, 5, ALGORITHM_LEFT_SYMMETRIC},
90 {"raid5_rs", "RAID5 (right symmetric)", 1, 2, 5, ALGORITHM_RIGHT_SYMMETRIC},
91 {"raid6_zr", "RAID6 (zero restart)", 2, 4, 6, ALGORITHM_ROTATING_ZERO_RESTART},
92 {"raid6_nr", "RAID6 (N restart)", 2, 4, 6, ALGORITHM_ROTATING_N_RESTART},
93 {"raid6_nc", "RAID6 (N continue)", 2, 4, 6, ALGORITHM_ROTATING_N_CONTINUE}
94 };
95
raid10_md_layout_to_format(int layout)96 static char *raid10_md_layout_to_format(int layout)
97 {
98 /*
99 * Bit 16 and 17 stand for "offset" and "use_far_sets"
100 * Refer to MD's raid10.c for details
101 */
102 if ((layout & 0x10000) && (layout & 0x20000))
103 return "offset";
104
105 if ((layout & 0xFF) > 1)
106 return "near";
107
108 return "far";
109 }
110
raid10_md_layout_to_copies(int layout)111 static unsigned raid10_md_layout_to_copies(int layout)
112 {
113 if ((layout & 0xFF) > 1)
114 return layout & 0xFF;
115 return (layout >> 8) & 0xFF;
116 }
117
raid10_format_to_md_layout(char * format,unsigned copies)118 static int raid10_format_to_md_layout(char *format, unsigned copies)
119 {
120 unsigned n = 1, f = 1;
121
122 if (!strcmp("near", format))
123 n = copies;
124 else
125 f = copies;
126
127 if (!strcmp("offset", format))
128 return 0x30000 | (f << 8) | n;
129
130 if (!strcmp("far", format))
131 return 0x20000 | (f << 8) | n;
132
133 return (f << 8) | n;
134 }
135
get_raid_type(char * name)136 static struct raid_type *get_raid_type(char *name)
137 {
138 int i;
139
140 for (i = 0; i < ARRAY_SIZE(raid_types); i++)
141 if (!strcmp(raid_types[i].name, name))
142 return &raid_types[i];
143
144 return NULL;
145 }
146
context_alloc(struct dm_target * ti,struct raid_type * raid_type,unsigned raid_devs)147 static struct raid_set *context_alloc(struct dm_target *ti, struct raid_type *raid_type, unsigned raid_devs)
148 {
149 unsigned i;
150 struct raid_set *rs;
151
152 if (raid_devs <= raid_type->parity_devs) {
153 ti->error = "Insufficient number of devices";
154 return ERR_PTR(-EINVAL);
155 }
156
157 rs = kzalloc(sizeof(*rs) + raid_devs * sizeof(rs->dev[0]), GFP_KERNEL);
158 if (!rs) {
159 ti->error = "Cannot allocate raid context";
160 return ERR_PTR(-ENOMEM);
161 }
162
163 mddev_init(&rs->md);
164
165 rs->ti = ti;
166 rs->raid_type = raid_type;
167 rs->md.raid_disks = raid_devs;
168 rs->md.level = raid_type->level;
169 rs->md.new_level = rs->md.level;
170 rs->md.layout = raid_type->algorithm;
171 rs->md.new_layout = rs->md.layout;
172 rs->md.delta_disks = 0;
173 rs->md.recovery_cp = 0;
174
175 for (i = 0; i < raid_devs; i++)
176 md_rdev_init(&rs->dev[i].rdev);
177
178 /*
179 * Remaining items to be initialized by further RAID params:
180 * rs->md.persistent
181 * rs->md.external
182 * rs->md.chunk_sectors
183 * rs->md.new_chunk_sectors
184 * rs->md.dev_sectors
185 */
186
187 return rs;
188 }
189
context_free(struct raid_set * rs)190 static void context_free(struct raid_set *rs)
191 {
192 int i;
193
194 for (i = 0; i < rs->md.raid_disks; i++) {
195 if (rs->dev[i].meta_dev)
196 dm_put_device(rs->ti, rs->dev[i].meta_dev);
197 md_rdev_clear(&rs->dev[i].rdev);
198 if (rs->dev[i].data_dev)
199 dm_put_device(rs->ti, rs->dev[i].data_dev);
200 }
201
202 kfree(rs);
203 }
204
205 /*
206 * For every device we have two words
207 * <meta_dev>: meta device name or '-' if missing
208 * <data_dev>: data device name or '-' if missing
209 *
210 * The following are permitted:
211 * - -
212 * - <data_dev>
213 * <meta_dev> <data_dev>
214 *
215 * The following is not allowed:
216 * <meta_dev> -
217 *
218 * This code parses those words. If there is a failure,
219 * the caller must use context_free to unwind the operations.
220 */
dev_parms(struct raid_set * rs,char ** argv)221 static int dev_parms(struct raid_set *rs, char **argv)
222 {
223 int i;
224 int rebuild = 0;
225 int metadata_available = 0;
226 int ret = 0;
227
228 for (i = 0; i < rs->md.raid_disks; i++, argv += 2) {
229 rs->dev[i].rdev.raid_disk = i;
230
231 rs->dev[i].meta_dev = NULL;
232 rs->dev[i].data_dev = NULL;
233
234 /*
235 * There are no offsets, since there is a separate device
236 * for data and metadata.
237 */
238 rs->dev[i].rdev.data_offset = 0;
239 rs->dev[i].rdev.mddev = &rs->md;
240
241 if (strcmp(argv[0], "-")) {
242 ret = dm_get_device(rs->ti, argv[0],
243 dm_table_get_mode(rs->ti->table),
244 &rs->dev[i].meta_dev);
245 rs->ti->error = "RAID metadata device lookup failure";
246 if (ret)
247 return ret;
248
249 rs->dev[i].rdev.sb_page = alloc_page(GFP_KERNEL);
250 if (!rs->dev[i].rdev.sb_page)
251 return -ENOMEM;
252 }
253
254 if (!strcmp(argv[1], "-")) {
255 if (!test_bit(In_sync, &rs->dev[i].rdev.flags) &&
256 (!rs->dev[i].rdev.recovery_offset)) {
257 rs->ti->error = "Drive designated for rebuild not specified";
258 return -EINVAL;
259 }
260
261 rs->ti->error = "No data device supplied with metadata device";
262 if (rs->dev[i].meta_dev)
263 return -EINVAL;
264
265 continue;
266 }
267
268 ret = dm_get_device(rs->ti, argv[1],
269 dm_table_get_mode(rs->ti->table),
270 &rs->dev[i].data_dev);
271 if (ret) {
272 rs->ti->error = "RAID device lookup failure";
273 return ret;
274 }
275
276 if (rs->dev[i].meta_dev) {
277 metadata_available = 1;
278 rs->dev[i].rdev.meta_bdev = rs->dev[i].meta_dev->bdev;
279 }
280 rs->dev[i].rdev.bdev = rs->dev[i].data_dev->bdev;
281 list_add(&rs->dev[i].rdev.same_set, &rs->md.disks);
282 if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
283 rebuild++;
284 }
285
286 if (metadata_available) {
287 rs->md.external = 0;
288 rs->md.persistent = 1;
289 rs->md.major_version = 2;
290 } else if (rebuild && !rs->md.recovery_cp) {
291 /*
292 * Without metadata, we will not be able to tell if the array
293 * is in-sync or not - we must assume it is not. Therefore,
294 * it is impossible to rebuild a drive.
295 *
296 * Even if there is metadata, the on-disk information may
297 * indicate that the array is not in-sync and it will then
298 * fail at that time.
299 *
300 * User could specify 'nosync' option if desperate.
301 */
302 DMERR("Unable to rebuild drive while array is not in-sync");
303 rs->ti->error = "RAID device lookup failure";
304 return -EINVAL;
305 }
306
307 return 0;
308 }
309
310 /*
311 * validate_region_size
312 * @rs
313 * @region_size: region size in sectors. If 0, pick a size (4MiB default).
314 *
315 * Set rs->md.bitmap_info.chunksize (which really refers to 'region size').
316 * Ensure that (ti->len/region_size < 2^21) - required by MD bitmap.
317 *
318 * Returns: 0 on success, -EINVAL on failure.
319 */
validate_region_size(struct raid_set * rs,unsigned long region_size)320 static int validate_region_size(struct raid_set *rs, unsigned long region_size)
321 {
322 unsigned long min_region_size = rs->ti->len / (1 << 21);
323
324 if (!region_size) {
325 /*
326 * Choose a reasonable default. All figures in sectors.
327 */
328 if (min_region_size > (1 << 13)) {
329 /* If not a power of 2, make it the next power of 2 */
330 region_size = roundup_pow_of_two(min_region_size);
331 DMINFO("Choosing default region size of %lu sectors",
332 region_size);
333 } else {
334 DMINFO("Choosing default region size of 4MiB");
335 region_size = 1 << 13; /* sectors */
336 }
337 } else {
338 /*
339 * Validate user-supplied value.
340 */
341 if (region_size > rs->ti->len) {
342 rs->ti->error = "Supplied region size is too large";
343 return -EINVAL;
344 }
345
346 if (region_size < min_region_size) {
347 DMERR("Supplied region_size (%lu sectors) below minimum (%lu)",
348 region_size, min_region_size);
349 rs->ti->error = "Supplied region size is too small";
350 return -EINVAL;
351 }
352
353 if (!is_power_of_2(region_size)) {
354 rs->ti->error = "Region size is not a power of 2";
355 return -EINVAL;
356 }
357
358 if (region_size < rs->md.chunk_sectors) {
359 rs->ti->error = "Region size is smaller than the chunk size";
360 return -EINVAL;
361 }
362 }
363
364 /*
365 * Convert sectors to bytes.
366 */
367 rs->md.bitmap_info.chunksize = (region_size << 9);
368
369 return 0;
370 }
371
372 /*
373 * validate_raid_redundancy
374 * @rs
375 *
376 * Determine if there are enough devices in the array that haven't
377 * failed (or are being rebuilt) to form a usable array.
378 *
379 * Returns: 0 on success, -EINVAL on failure.
380 */
validate_raid_redundancy(struct raid_set * rs)381 static int validate_raid_redundancy(struct raid_set *rs)
382 {
383 unsigned i, rebuild_cnt = 0;
384 unsigned rebuilds_per_group = 0, copies, d;
385 unsigned group_size, last_group_start;
386
387 for (i = 0; i < rs->md.raid_disks; i++)
388 if (!test_bit(In_sync, &rs->dev[i].rdev.flags) ||
389 !rs->dev[i].rdev.sb_page)
390 rebuild_cnt++;
391
392 switch (rs->raid_type->level) {
393 case 1:
394 if (rebuild_cnt >= rs->md.raid_disks)
395 goto too_many;
396 break;
397 case 4:
398 case 5:
399 case 6:
400 if (rebuild_cnt > rs->raid_type->parity_devs)
401 goto too_many;
402 break;
403 case 10:
404 copies = raid10_md_layout_to_copies(rs->md.layout);
405 if (rebuild_cnt < copies)
406 break;
407
408 /*
409 * It is possible to have a higher rebuild count for RAID10,
410 * as long as the failed devices occur in different mirror
411 * groups (i.e. different stripes).
412 *
413 * When checking "near" format, make sure no adjacent devices
414 * have failed beyond what can be handled. In addition to the
415 * simple case where the number of devices is a multiple of the
416 * number of copies, we must also handle cases where the number
417 * of devices is not a multiple of the number of copies.
418 * E.g. dev1 dev2 dev3 dev4 dev5
419 * A A B B C
420 * C D D E E
421 */
422 if (!strcmp("near", raid10_md_layout_to_format(rs->md.layout))) {
423 for (i = 0; i < rs->md.raid_disks * copies; i++) {
424 if (!(i % copies))
425 rebuilds_per_group = 0;
426 d = i % rs->md.raid_disks;
427 if ((!rs->dev[d].rdev.sb_page ||
428 !test_bit(In_sync, &rs->dev[d].rdev.flags)) &&
429 (++rebuilds_per_group >= copies))
430 goto too_many;
431 }
432 break;
433 }
434
435 /*
436 * When checking "far" and "offset" formats, we need to ensure
437 * that the device that holds its copy is not also dead or
438 * being rebuilt. (Note that "far" and "offset" formats only
439 * support two copies right now. These formats also only ever
440 * use the 'use_far_sets' variant.)
441 *
442 * This check is somewhat complicated by the need to account
443 * for arrays that are not a multiple of (far) copies. This
444 * results in the need to treat the last (potentially larger)
445 * set differently.
446 */
447 group_size = (rs->md.raid_disks / copies);
448 last_group_start = (rs->md.raid_disks / group_size) - 1;
449 last_group_start *= group_size;
450 for (i = 0; i < rs->md.raid_disks; i++) {
451 if (!(i % copies) && !(i > last_group_start))
452 rebuilds_per_group = 0;
453 if ((!rs->dev[i].rdev.sb_page ||
454 !test_bit(In_sync, &rs->dev[i].rdev.flags)) &&
455 (++rebuilds_per_group >= copies))
456 goto too_many;
457 }
458 break;
459 default:
460 if (rebuild_cnt)
461 return -EINVAL;
462 }
463
464 return 0;
465
466 too_many:
467 return -EINVAL;
468 }
469
470 /*
471 * Possible arguments are...
472 * <chunk_size> [optional_args]
473 *
474 * Argument definitions
475 * <chunk_size> The number of sectors per disk that
476 * will form the "stripe"
477 * [[no]sync] Force or prevent recovery of the
478 * entire array
479 * [devices_handle_discard_safely] Allow discards on RAID4/5/6; useful if RAID
480 * member device(s) properly support TRIM/UNMAP
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 */
parse_raid_params(struct raid_set * rs,char ** argv,unsigned num_raid_params)495 static 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->print_flags |= DMPF_NOSYNC;
558 continue;
559 }
560 if (!strcasecmp(argv[i], "sync")) {
561 rs->md.recovery_cp = 0;
562 rs->print_flags |= DMPF_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->print_flags |= DMPF_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->print_flags |= DMPF_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->print_flags |= DMPF_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->print_flags |= DMPF_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->print_flags |= DMPF_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->print_flags |= DMPF_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->print_flags |= DMPF_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->print_flags |= DMPF_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->print_flags |= DMPF_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 > 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
do_table_event(struct work_struct * ws)737 static 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
raid_is_congested(struct dm_target_callbacks * cb,int bits)744 static 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
756 struct 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
read_disk_sb(struct md_rdev * rdev,int size)788 static 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
super_sync(struct mddev * mddev,struct md_rdev * rdev)807 static 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 */
super_load(struct md_rdev * rdev,struct md_rdev * refdev)849 static 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
super_init_validation(struct mddev * mddev,struct md_rdev * rdev)898 static 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->print_flags & (DMPF_SYNC | DMPF_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
super_validate(struct mddev * mddev,struct md_rdev * rdev)1028 static int super_validate(struct mddev *mddev, struct md_rdev *rdev)
1029 {
1030 struct dm_raid_superblock *sb = page_address(rdev->sb_page);
1031
1032 /*
1033 * If mddev->events is not set, we know we have not yet initialized
1034 * the array.
1035 */
1036 if (!mddev->events && super_init_validation(mddev, rdev))
1037 return -EINVAL;
1038
1039 mddev->bitmap_info.offset = 4096 >> 9; /* Enable bitmap creation */
1040 rdev->mddev->bitmap_info.default_offset = 4096 >> 9;
1041 if (!test_bit(FirstUse, &rdev->flags)) {
1042 rdev->recovery_offset = le64_to_cpu(sb->disk_recovery_offset);
1043 if (rdev->recovery_offset != MaxSector)
1044 clear_bit(In_sync, &rdev->flags);
1045 }
1046
1047 /*
1048 * If a device comes back, set it as not In_sync and no longer faulty.
1049 */
1050 if (test_bit(Faulty, &rdev->flags)) {
1051 clear_bit(Faulty, &rdev->flags);
1052 clear_bit(In_sync, &rdev->flags);
1053 rdev->saved_raid_disk = rdev->raid_disk;
1054 rdev->recovery_offset = 0;
1055 }
1056
1057 clear_bit(FirstUse, &rdev->flags);
1058
1059 return 0;
1060 }
1061
1062 /*
1063 * Analyse superblocks and select the freshest.
1064 */
analyse_superblocks(struct dm_target * ti,struct raid_set * rs)1065 static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
1066 {
1067 int ret;
1068 struct raid_dev *dev;
1069 struct md_rdev *rdev, *tmp, *freshest;
1070 struct mddev *mddev = &rs->md;
1071
1072 freshest = NULL;
1073 rdev_for_each_safe(rdev, tmp, mddev) {
1074 /*
1075 * Skipping super_load due to DMPF_SYNC will cause
1076 * the array to undergo initialization again as
1077 * though it were new. This is the intended effect
1078 * of the "sync" directive.
1079 *
1080 * When reshaping capability is added, we must ensure
1081 * that the "sync" directive is disallowed during the
1082 * reshape.
1083 */
1084 if (rs->print_flags & DMPF_SYNC)
1085 continue;
1086
1087 if (!rdev->meta_bdev)
1088 continue;
1089
1090 ret = super_load(rdev, freshest);
1091
1092 switch (ret) {
1093 case 1:
1094 freshest = rdev;
1095 break;
1096 case 0:
1097 break;
1098 default:
1099 dev = container_of(rdev, struct raid_dev, rdev);
1100 if (dev->meta_dev)
1101 dm_put_device(ti, dev->meta_dev);
1102
1103 dev->meta_dev = NULL;
1104 rdev->meta_bdev = NULL;
1105
1106 if (rdev->sb_page)
1107 put_page(rdev->sb_page);
1108
1109 rdev->sb_page = NULL;
1110
1111 rdev->sb_loaded = 0;
1112
1113 /*
1114 * We might be able to salvage the data device
1115 * even though the meta device has failed. For
1116 * now, we behave as though '- -' had been
1117 * set for this device in the table.
1118 */
1119 if (dev->data_dev)
1120 dm_put_device(ti, dev->data_dev);
1121
1122 dev->data_dev = NULL;
1123 rdev->bdev = NULL;
1124
1125 list_del(&rdev->same_set);
1126 }
1127 }
1128
1129 if (!freshest)
1130 return 0;
1131
1132 if (validate_raid_redundancy(rs)) {
1133 rs->ti->error = "Insufficient redundancy to activate array";
1134 return -EINVAL;
1135 }
1136
1137 /*
1138 * Validation of the freshest device provides the source of
1139 * validation for the remaining devices.
1140 */
1141 ti->error = "Unable to assemble array: Invalid superblocks";
1142 if (super_validate(mddev, freshest))
1143 return -EINVAL;
1144
1145 rdev_for_each(rdev, mddev)
1146 if ((rdev != freshest) && super_validate(mddev, rdev))
1147 return -EINVAL;
1148
1149 return 0;
1150 }
1151
1152 /*
1153 * Enable/disable discard support on RAID set depending on
1154 * RAID level and discard properties of underlying RAID members.
1155 */
configure_discard_support(struct dm_target * ti,struct raid_set * rs)1156 static void configure_discard_support(struct dm_target *ti, struct raid_set *rs)
1157 {
1158 int i;
1159 bool raid456;
1160
1161 /* Assume discards not supported until after checks below. */
1162 ti->discards_supported = false;
1163
1164 /* RAID level 4,5,6 require discard_zeroes_data for data integrity! */
1165 raid456 = (rs->md.level == 4 || rs->md.level == 5 || rs->md.level == 6);
1166
1167 for (i = 0; i < rs->md.raid_disks; i++) {
1168 struct request_queue *q;
1169
1170 if (!rs->dev[i].rdev.bdev)
1171 continue;
1172
1173 q = bdev_get_queue(rs->dev[i].rdev.bdev);
1174 if (!q || !blk_queue_discard(q))
1175 return;
1176
1177 if (raid456) {
1178 if (!q->limits.discard_zeroes_data)
1179 return;
1180 if (!devices_handle_discard_safely) {
1181 DMERR("raid456 discard support disabled due to discard_zeroes_data uncertainty.");
1182 DMERR("Set dm-raid.devices_handle_discard_safely=Y to override.");
1183 return;
1184 }
1185 }
1186 }
1187
1188 /* All RAID members properly support discards */
1189 ti->discards_supported = true;
1190
1191 /*
1192 * RAID1 and RAID10 personalities require bio splitting,
1193 * RAID0/4/5/6 don't and process large discard bios properly.
1194 */
1195 ti->split_discard_bios = !!(rs->md.level == 1 || rs->md.level == 10);
1196 ti->num_discard_bios = 1;
1197 }
1198
1199 /*
1200 * Construct a RAID4/5/6 mapping:
1201 * Args:
1202 * <raid_type> <#raid_params> <raid_params> \
1203 * <#raid_devs> { <meta_dev1> <dev1> .. <meta_devN> <devN> }
1204 *
1205 * <raid_params> varies by <raid_type>. See 'parse_raid_params' for
1206 * details on possible <raid_params>.
1207 */
raid_ctr(struct dm_target * ti,unsigned argc,char ** argv)1208 static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
1209 {
1210 int ret;
1211 struct raid_type *rt;
1212 unsigned long num_raid_params, num_raid_devs;
1213 struct raid_set *rs = NULL;
1214
1215 /* Must have at least <raid_type> <#raid_params> */
1216 if (argc < 2) {
1217 ti->error = "Too few arguments";
1218 return -EINVAL;
1219 }
1220
1221 /* raid type */
1222 rt = get_raid_type(argv[0]);
1223 if (!rt) {
1224 ti->error = "Unrecognised raid_type";
1225 return -EINVAL;
1226 }
1227 argc--;
1228 argv++;
1229
1230 /* number of RAID parameters */
1231 if (kstrtoul(argv[0], 10, &num_raid_params) < 0) {
1232 ti->error = "Cannot understand number of RAID parameters";
1233 return -EINVAL;
1234 }
1235 argc--;
1236 argv++;
1237
1238 /* Skip over RAID params for now and find out # of devices */
1239 if (num_raid_params >= argc) {
1240 ti->error = "Arguments do not agree with counts given";
1241 return -EINVAL;
1242 }
1243
1244 if ((kstrtoul(argv[num_raid_params], 10, &num_raid_devs) < 0) ||
1245 (num_raid_devs >= INT_MAX)) {
1246 ti->error = "Cannot understand number of raid devices";
1247 return -EINVAL;
1248 }
1249
1250 argc -= num_raid_params + 1; /* +1: we already have num_raid_devs */
1251 if (argc != (num_raid_devs * 2)) {
1252 ti->error = "Supplied RAID devices does not match the count given";
1253 return -EINVAL;
1254 }
1255
1256 rs = context_alloc(ti, rt, (unsigned)num_raid_devs);
1257 if (IS_ERR(rs))
1258 return PTR_ERR(rs);
1259
1260 ret = parse_raid_params(rs, argv, (unsigned)num_raid_params);
1261 if (ret)
1262 goto bad;
1263
1264 argv += num_raid_params + 1;
1265
1266 ret = dev_parms(rs, argv);
1267 if (ret)
1268 goto bad;
1269
1270 rs->md.sync_super = super_sync;
1271 ret = analyse_superblocks(ti, rs);
1272 if (ret)
1273 goto bad;
1274
1275 INIT_WORK(&rs->md.event_work, do_table_event);
1276 ti->private = rs;
1277 ti->num_flush_bios = 1;
1278
1279 /*
1280 * Disable/enable discard support on RAID set.
1281 */
1282 configure_discard_support(ti, rs);
1283
1284 mutex_lock(&rs->md.reconfig_mutex);
1285 ret = md_run(&rs->md);
1286 rs->md.in_sync = 0; /* Assume already marked dirty */
1287 mutex_unlock(&rs->md.reconfig_mutex);
1288
1289 if (ret) {
1290 ti->error = "Fail to run raid array";
1291 goto bad;
1292 }
1293
1294 if (ti->len != rs->md.array_sectors) {
1295 ti->error = "Array size does not match requested target length";
1296 ret = -EINVAL;
1297 goto size_mismatch;
1298 }
1299 rs->callbacks.congested_fn = raid_is_congested;
1300 dm_table_add_target_callbacks(ti->table, &rs->callbacks);
1301
1302 mddev_suspend(&rs->md);
1303 return 0;
1304
1305 size_mismatch:
1306 md_stop(&rs->md);
1307 bad:
1308 context_free(rs);
1309
1310 return ret;
1311 }
1312
raid_dtr(struct dm_target * ti)1313 static void raid_dtr(struct dm_target *ti)
1314 {
1315 struct raid_set *rs = ti->private;
1316
1317 list_del_init(&rs->callbacks.list);
1318 md_stop(&rs->md);
1319 context_free(rs);
1320 }
1321
raid_map(struct dm_target * ti,struct bio * bio)1322 static int raid_map(struct dm_target *ti, struct bio *bio)
1323 {
1324 struct raid_set *rs = ti->private;
1325 struct mddev *mddev = &rs->md;
1326
1327 mddev->pers->make_request(mddev, bio);
1328
1329 return DM_MAPIO_SUBMITTED;
1330 }
1331
decipher_sync_action(struct mddev * mddev)1332 static const char *decipher_sync_action(struct mddev *mddev)
1333 {
1334 if (test_bit(MD_RECOVERY_FROZEN, &mddev->recovery))
1335 return "frozen";
1336
1337 if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
1338 (!mddev->ro && test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))) {
1339 if (test_bit(MD_RECOVERY_RESHAPE, &mddev->recovery))
1340 return "reshape";
1341
1342 if (test_bit(MD_RECOVERY_SYNC, &mddev->recovery)) {
1343 if (!test_bit(MD_RECOVERY_REQUESTED, &mddev->recovery))
1344 return "resync";
1345 else if (test_bit(MD_RECOVERY_CHECK, &mddev->recovery))
1346 return "check";
1347 return "repair";
1348 }
1349
1350 if (test_bit(MD_RECOVERY_RECOVER, &mddev->recovery))
1351 return "recover";
1352 }
1353
1354 return "idle";
1355 }
1356
raid_status(struct dm_target * ti,status_type_t type,unsigned status_flags,char * result,unsigned maxlen)1357 static void raid_status(struct dm_target *ti, status_type_t type,
1358 unsigned status_flags, char *result, unsigned maxlen)
1359 {
1360 struct raid_set *rs = ti->private;
1361 unsigned raid_param_cnt = 1; /* at least 1 for chunksize */
1362 unsigned sz = 0;
1363 int i, array_in_sync = 0;
1364 sector_t sync;
1365
1366 switch (type) {
1367 case STATUSTYPE_INFO:
1368 DMEMIT("%s %d ", rs->raid_type->name, rs->md.raid_disks);
1369
1370 if (test_bit(MD_RECOVERY_RUNNING, &rs->md.recovery))
1371 sync = rs->md.curr_resync_completed;
1372 else
1373 sync = rs->md.recovery_cp;
1374
1375 if (sync >= rs->md.resync_max_sectors) {
1376 /*
1377 * Sync complete.
1378 */
1379 array_in_sync = 1;
1380 sync = rs->md.resync_max_sectors;
1381 } else if (test_bit(MD_RECOVERY_REQUESTED, &rs->md.recovery)) {
1382 /*
1383 * If "check" or "repair" is occurring, the array has
1384 * undergone and initial sync and the health characters
1385 * should not be 'a' anymore.
1386 */
1387 array_in_sync = 1;
1388 } else {
1389 /*
1390 * The array may be doing an initial sync, or it may
1391 * be rebuilding individual components. If all the
1392 * devices are In_sync, then it is the array that is
1393 * being initialized.
1394 */
1395 for (i = 0; i < rs->md.raid_disks; i++)
1396 if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
1397 array_in_sync = 1;
1398 }
1399
1400 /*
1401 * Status characters:
1402 * 'D' = Dead/Failed device
1403 * 'a' = Alive but not in-sync
1404 * 'A' = Alive and in-sync
1405 */
1406 for (i = 0; i < rs->md.raid_disks; i++) {
1407 if (test_bit(Faulty, &rs->dev[i].rdev.flags))
1408 DMEMIT("D");
1409 else if (!array_in_sync ||
1410 !test_bit(In_sync, &rs->dev[i].rdev.flags))
1411 DMEMIT("a");
1412 else
1413 DMEMIT("A");
1414 }
1415
1416 /*
1417 * In-sync ratio:
1418 * The in-sync ratio shows the progress of:
1419 * - Initializing the array
1420 * - Rebuilding a subset of devices of the array
1421 * The user can distinguish between the two by referring
1422 * to the status characters.
1423 */
1424 DMEMIT(" %llu/%llu",
1425 (unsigned long long) sync,
1426 (unsigned long long) rs->md.resync_max_sectors);
1427
1428 /*
1429 * Sync action:
1430 * See Documentation/device-mapper/dm-raid.c for
1431 * information on each of these states.
1432 */
1433 DMEMIT(" %s", decipher_sync_action(&rs->md));
1434
1435 /*
1436 * resync_mismatches/mismatch_cnt
1437 * This field shows the number of discrepancies found when
1438 * performing a "check" of the array.
1439 */
1440 DMEMIT(" %llu",
1441 (strcmp(rs->md.last_sync_action, "check")) ? 0 :
1442 (unsigned long long)
1443 atomic64_read(&rs->md.resync_mismatches));
1444 break;
1445 case STATUSTYPE_TABLE:
1446 /* The string you would use to construct this array */
1447 for (i = 0; i < rs->md.raid_disks; i++) {
1448 if ((rs->print_flags & DMPF_REBUILD) &&
1449 rs->dev[i].data_dev &&
1450 !test_bit(In_sync, &rs->dev[i].rdev.flags))
1451 raid_param_cnt += 2; /* for rebuilds */
1452 if (rs->dev[i].data_dev &&
1453 test_bit(WriteMostly, &rs->dev[i].rdev.flags))
1454 raid_param_cnt += 2;
1455 }
1456
1457 raid_param_cnt += (hweight32(rs->print_flags & ~DMPF_REBUILD) * 2);
1458 if (rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC))
1459 raid_param_cnt--;
1460
1461 DMEMIT("%s %u %u", rs->raid_type->name,
1462 raid_param_cnt, rs->md.chunk_sectors);
1463
1464 if ((rs->print_flags & DMPF_SYNC) &&
1465 (rs->md.recovery_cp == MaxSector))
1466 DMEMIT(" sync");
1467 if (rs->print_flags & DMPF_NOSYNC)
1468 DMEMIT(" nosync");
1469
1470 for (i = 0; i < rs->md.raid_disks; i++)
1471 if ((rs->print_flags & DMPF_REBUILD) &&
1472 rs->dev[i].data_dev &&
1473 !test_bit(In_sync, &rs->dev[i].rdev.flags))
1474 DMEMIT(" rebuild %u", i);
1475
1476 if (rs->print_flags & DMPF_DAEMON_SLEEP)
1477 DMEMIT(" daemon_sleep %lu",
1478 rs->md.bitmap_info.daemon_sleep);
1479
1480 if (rs->print_flags & DMPF_MIN_RECOVERY_RATE)
1481 DMEMIT(" min_recovery_rate %d", rs->md.sync_speed_min);
1482
1483 if (rs->print_flags & DMPF_MAX_RECOVERY_RATE)
1484 DMEMIT(" max_recovery_rate %d", rs->md.sync_speed_max);
1485
1486 for (i = 0; i < rs->md.raid_disks; i++)
1487 if (rs->dev[i].data_dev &&
1488 test_bit(WriteMostly, &rs->dev[i].rdev.flags))
1489 DMEMIT(" write_mostly %u", i);
1490
1491 if (rs->print_flags & DMPF_MAX_WRITE_BEHIND)
1492 DMEMIT(" max_write_behind %lu",
1493 rs->md.bitmap_info.max_write_behind);
1494
1495 if (rs->print_flags & DMPF_STRIPE_CACHE) {
1496 struct r5conf *conf = rs->md.private;
1497
1498 /* convert from kiB to sectors */
1499 DMEMIT(" stripe_cache %d",
1500 conf ? conf->max_nr_stripes * 2 : 0);
1501 }
1502
1503 if (rs->print_flags & DMPF_REGION_SIZE)
1504 DMEMIT(" region_size %lu",
1505 rs->md.bitmap_info.chunksize >> 9);
1506
1507 if (rs->print_flags & DMPF_RAID10_COPIES)
1508 DMEMIT(" raid10_copies %u",
1509 raid10_md_layout_to_copies(rs->md.layout));
1510
1511 if (rs->print_flags & DMPF_RAID10_FORMAT)
1512 DMEMIT(" raid10_format %s",
1513 raid10_md_layout_to_format(rs->md.layout));
1514
1515 DMEMIT(" %d", rs->md.raid_disks);
1516 for (i = 0; i < rs->md.raid_disks; i++) {
1517 if (rs->dev[i].meta_dev)
1518 DMEMIT(" %s", rs->dev[i].meta_dev->name);
1519 else
1520 DMEMIT(" -");
1521
1522 if (rs->dev[i].data_dev)
1523 DMEMIT(" %s", rs->dev[i].data_dev->name);
1524 else
1525 DMEMIT(" -");
1526 }
1527 }
1528 }
1529
raid_message(struct dm_target * ti,unsigned argc,char ** argv)1530 static int raid_message(struct dm_target *ti, unsigned argc, char **argv)
1531 {
1532 struct raid_set *rs = ti->private;
1533 struct mddev *mddev = &rs->md;
1534
1535 if (!strcasecmp(argv[0], "reshape")) {
1536 DMERR("Reshape not supported.");
1537 return -EINVAL;
1538 }
1539
1540 if (!mddev->pers || !mddev->pers->sync_request)
1541 return -EINVAL;
1542
1543 if (!strcasecmp(argv[0], "frozen"))
1544 set_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
1545 else
1546 clear_bit(MD_RECOVERY_FROZEN, &mddev->recovery);
1547
1548 if (!strcasecmp(argv[0], "idle") || !strcasecmp(argv[0], "frozen")) {
1549 if (mddev->sync_thread) {
1550 set_bit(MD_RECOVERY_INTR, &mddev->recovery);
1551 md_reap_sync_thread(mddev);
1552 }
1553 } else if (test_bit(MD_RECOVERY_RUNNING, &mddev->recovery) ||
1554 test_bit(MD_RECOVERY_NEEDED, &mddev->recovery))
1555 return -EBUSY;
1556 else if (!strcasecmp(argv[0], "resync"))
1557 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
1558 else if (!strcasecmp(argv[0], "recover")) {
1559 set_bit(MD_RECOVERY_RECOVER, &mddev->recovery);
1560 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
1561 } else {
1562 if (!strcasecmp(argv[0], "check"))
1563 set_bit(MD_RECOVERY_CHECK, &mddev->recovery);
1564 else if (!!strcasecmp(argv[0], "repair"))
1565 return -EINVAL;
1566 set_bit(MD_RECOVERY_REQUESTED, &mddev->recovery);
1567 set_bit(MD_RECOVERY_SYNC, &mddev->recovery);
1568 }
1569 if (mddev->ro == 2) {
1570 /* A write to sync_action is enough to justify
1571 * canceling read-auto mode
1572 */
1573 mddev->ro = 0;
1574 if (!mddev->suspended)
1575 md_wakeup_thread(mddev->sync_thread);
1576 }
1577 set_bit(MD_RECOVERY_NEEDED, &mddev->recovery);
1578 if (!mddev->suspended)
1579 md_wakeup_thread(mddev->thread);
1580
1581 return 0;
1582 }
1583
raid_iterate_devices(struct dm_target * ti,iterate_devices_callout_fn fn,void * data)1584 static int raid_iterate_devices(struct dm_target *ti,
1585 iterate_devices_callout_fn fn, void *data)
1586 {
1587 struct raid_set *rs = ti->private;
1588 unsigned i;
1589 int ret = 0;
1590
1591 for (i = 0; !ret && i < rs->md.raid_disks; i++)
1592 if (rs->dev[i].data_dev)
1593 ret = fn(ti,
1594 rs->dev[i].data_dev,
1595 0, /* No offset on data devs */
1596 rs->md.dev_sectors,
1597 data);
1598
1599 return ret;
1600 }
1601
raid_io_hints(struct dm_target * ti,struct queue_limits * limits)1602 static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
1603 {
1604 struct raid_set *rs = ti->private;
1605 unsigned chunk_size = rs->md.chunk_sectors << 9;
1606 struct r5conf *conf = rs->md.private;
1607
1608 blk_limits_io_min(limits, chunk_size);
1609 blk_limits_io_opt(limits, chunk_size * (conf->raid_disks - conf->max_degraded));
1610 }
1611
raid_presuspend(struct dm_target * ti)1612 static void raid_presuspend(struct dm_target *ti)
1613 {
1614 struct raid_set *rs = ti->private;
1615
1616 md_stop_writes(&rs->md);
1617 }
1618
raid_postsuspend(struct dm_target * ti)1619 static void raid_postsuspend(struct dm_target *ti)
1620 {
1621 struct raid_set *rs = ti->private;
1622
1623 mddev_suspend(&rs->md);
1624 }
1625
attempt_restore_of_faulty_devices(struct raid_set * rs)1626 static void attempt_restore_of_faulty_devices(struct raid_set *rs)
1627 {
1628 int i;
1629 uint64_t failed_devices, cleared_failed_devices = 0;
1630 unsigned long flags;
1631 struct dm_raid_superblock *sb;
1632 struct md_rdev *r;
1633
1634 for (i = 0; i < rs->md.raid_disks; i++) {
1635 r = &rs->dev[i].rdev;
1636 if (test_bit(Faulty, &r->flags) && r->sb_page &&
1637 sync_page_io(r, 0, r->sb_size, r->sb_page, READ, 1)) {
1638 DMINFO("Faulty %s device #%d has readable super block."
1639 " Attempting to revive it.",
1640 rs->raid_type->name, i);
1641
1642 /*
1643 * Faulty bit may be set, but sometimes the array can
1644 * be suspended before the personalities can respond
1645 * by removing the device from the array (i.e. calling
1646 * 'hot_remove_disk'). If they haven't yet removed
1647 * the failed device, its 'raid_disk' number will be
1648 * '>= 0' - meaning we must call this function
1649 * ourselves.
1650 */
1651 if ((r->raid_disk >= 0) &&
1652 (r->mddev->pers->hot_remove_disk(r->mddev, r) != 0))
1653 /* Failed to revive this device, try next */
1654 continue;
1655
1656 r->raid_disk = i;
1657 r->saved_raid_disk = i;
1658 flags = r->flags;
1659 clear_bit(Faulty, &r->flags);
1660 clear_bit(WriteErrorSeen, &r->flags);
1661 clear_bit(In_sync, &r->flags);
1662 if (r->mddev->pers->hot_add_disk(r->mddev, r)) {
1663 r->raid_disk = -1;
1664 r->saved_raid_disk = -1;
1665 r->flags = flags;
1666 } else {
1667 r->recovery_offset = 0;
1668 cleared_failed_devices |= 1 << i;
1669 }
1670 }
1671 }
1672 if (cleared_failed_devices) {
1673 rdev_for_each(r, &rs->md) {
1674 sb = page_address(r->sb_page);
1675 failed_devices = le64_to_cpu(sb->failed_devices);
1676 failed_devices &= ~cleared_failed_devices;
1677 sb->failed_devices = cpu_to_le64(failed_devices);
1678 }
1679 }
1680 }
1681
raid_resume(struct dm_target * ti)1682 static void raid_resume(struct dm_target *ti)
1683 {
1684 struct raid_set *rs = ti->private;
1685
1686 set_bit(MD_CHANGE_DEVS, &rs->md.flags);
1687 if (!rs->bitmap_loaded) {
1688 bitmap_load(&rs->md);
1689 rs->bitmap_loaded = 1;
1690 } else {
1691 /*
1692 * A secondary resume while the device is active.
1693 * Take this opportunity to check whether any failed
1694 * devices are reachable again.
1695 */
1696 attempt_restore_of_faulty_devices(rs);
1697 }
1698
1699 clear_bit(MD_RECOVERY_FROZEN, &rs->md.recovery);
1700 mddev_resume(&rs->md);
1701 }
1702
1703 static struct target_type raid_target = {
1704 .name = "raid",
1705 .version = {1, 6, 0},
1706 .module = THIS_MODULE,
1707 .ctr = raid_ctr,
1708 .dtr = raid_dtr,
1709 .map = raid_map,
1710 .status = raid_status,
1711 .message = raid_message,
1712 .iterate_devices = raid_iterate_devices,
1713 .io_hints = raid_io_hints,
1714 .presuspend = raid_presuspend,
1715 .postsuspend = raid_postsuspend,
1716 .resume = raid_resume,
1717 };
1718
dm_raid_init(void)1719 static int __init dm_raid_init(void)
1720 {
1721 DMINFO("Loading target version %u.%u.%u",
1722 raid_target.version[0],
1723 raid_target.version[1],
1724 raid_target.version[2]);
1725 return dm_register_target(&raid_target);
1726 }
1727
dm_raid_exit(void)1728 static void __exit dm_raid_exit(void)
1729 {
1730 dm_unregister_target(&raid_target);
1731 }
1732
1733 module_init(dm_raid_init);
1734 module_exit(dm_raid_exit);
1735
1736 module_param(devices_handle_discard_safely, bool, 0644);
1737 MODULE_PARM_DESC(devices_handle_discard_safely,
1738 "Set to Y if all devices in each array reliably return zeroes on reads from discarded regions");
1739
1740 MODULE_DESCRIPTION(DM_NAME " raid4/5/6 target");
1741 MODULE_ALIAS("dm-raid1");
1742 MODULE_ALIAS("dm-raid10");
1743 MODULE_ALIAS("dm-raid4");
1744 MODULE_ALIAS("dm-raid5");
1745 MODULE_ALIAS("dm-raid6");
1746 MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>");
1747 MODULE_LICENSE("GPL");
1748