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 #include <linux/module.h>
10
11 #include "md.h"
12 #include "raid1.h"
13 #include "raid5.h"
14 #include "bitmap.h"
15
16 #include <linux/device-mapper.h>
17
18 #define DM_MSG_PREFIX "raid"
19
20 /*
21 * The following flags are used by dm-raid.c to set up the array state.
22 * They must be cleared before md_run is called.
23 */
24 #define FirstUse 10 /* rdev flag */
25
26 struct raid_dev {
27 /*
28 * Two DM devices, one to hold metadata and one to hold the
29 * actual data/parity. The reason for this is to not confuse
30 * ti->len and give more flexibility in altering size and
31 * characteristics.
32 *
33 * While it is possible for this device to be associated
34 * with a different physical device than the data_dev, it
35 * is intended for it to be the same.
36 * |--------- Physical Device ---------|
37 * |- meta_dev -|------ data_dev ------|
38 */
39 struct dm_dev *meta_dev;
40 struct dm_dev *data_dev;
41 struct md_rdev rdev;
42 };
43
44 /*
45 * Flags for rs->print_flags field.
46 */
47 #define DMPF_SYNC 0x1
48 #define DMPF_NOSYNC 0x2
49 #define DMPF_REBUILD 0x4
50 #define DMPF_DAEMON_SLEEP 0x8
51 #define DMPF_MIN_RECOVERY_RATE 0x10
52 #define DMPF_MAX_RECOVERY_RATE 0x20
53 #define DMPF_MAX_WRITE_BEHIND 0x40
54 #define DMPF_STRIPE_CACHE 0x80
55 #define DMPF_REGION_SIZE 0X100
56 struct raid_set {
57 struct dm_target *ti;
58
59 uint32_t bitmap_loaded;
60 uint32_t print_flags;
61
62 struct mddev md;
63 struct raid_type *raid_type;
64 struct dm_target_callbacks callbacks;
65
66 struct raid_dev dev[0];
67 };
68
69 /* Supported raid types and properties. */
70 static struct raid_type {
71 const char *name; /* RAID algorithm. */
72 const char *descr; /* Descriptor text for logging. */
73 const unsigned parity_devs; /* # of parity devices. */
74 const unsigned minimal_devs; /* minimal # of devices in set. */
75 const unsigned level; /* RAID level. */
76 const unsigned algorithm; /* RAID algorithm. */
77 } raid_types[] = {
78 {"raid1", "RAID1 (mirroring)", 0, 2, 1, 0 /* NONE */},
79 {"raid4", "RAID4 (dedicated parity disk)", 1, 2, 5, ALGORITHM_PARITY_0},
80 {"raid5_la", "RAID5 (left asymmetric)", 1, 2, 5, ALGORITHM_LEFT_ASYMMETRIC},
81 {"raid5_ra", "RAID5 (right asymmetric)", 1, 2, 5, ALGORITHM_RIGHT_ASYMMETRIC},
82 {"raid5_ls", "RAID5 (left symmetric)", 1, 2, 5, ALGORITHM_LEFT_SYMMETRIC},
83 {"raid5_rs", "RAID5 (right symmetric)", 1, 2, 5, ALGORITHM_RIGHT_SYMMETRIC},
84 {"raid6_zr", "RAID6 (zero restart)", 2, 4, 6, ALGORITHM_ROTATING_ZERO_RESTART},
85 {"raid6_nr", "RAID6 (N restart)", 2, 4, 6, ALGORITHM_ROTATING_N_RESTART},
86 {"raid6_nc", "RAID6 (N continue)", 2, 4, 6, ALGORITHM_ROTATING_N_CONTINUE}
87 };
88
get_raid_type(char * name)89 static struct raid_type *get_raid_type(char *name)
90 {
91 int i;
92
93 for (i = 0; i < ARRAY_SIZE(raid_types); i++)
94 if (!strcmp(raid_types[i].name, name))
95 return &raid_types[i];
96
97 return NULL;
98 }
99
context_alloc(struct dm_target * ti,struct raid_type * raid_type,unsigned raid_devs)100 static struct raid_set *context_alloc(struct dm_target *ti, struct raid_type *raid_type, unsigned raid_devs)
101 {
102 unsigned i;
103 struct raid_set *rs;
104 sector_t sectors_per_dev;
105
106 if (raid_devs <= raid_type->parity_devs) {
107 ti->error = "Insufficient number of devices";
108 return ERR_PTR(-EINVAL);
109 }
110
111 sectors_per_dev = ti->len;
112 if ((raid_type->level > 1) &&
113 sector_div(sectors_per_dev, (raid_devs - raid_type->parity_devs))) {
114 ti->error = "Target length not divisible by number of data devices";
115 return ERR_PTR(-EINVAL);
116 }
117
118 rs = kzalloc(sizeof(*rs) + raid_devs * sizeof(rs->dev[0]), GFP_KERNEL);
119 if (!rs) {
120 ti->error = "Cannot allocate raid context";
121 return ERR_PTR(-ENOMEM);
122 }
123
124 mddev_init(&rs->md);
125
126 rs->ti = ti;
127 rs->raid_type = raid_type;
128 rs->md.raid_disks = raid_devs;
129 rs->md.level = raid_type->level;
130 rs->md.new_level = rs->md.level;
131 rs->md.dev_sectors = sectors_per_dev;
132 rs->md.layout = raid_type->algorithm;
133 rs->md.new_layout = rs->md.layout;
134 rs->md.delta_disks = 0;
135 rs->md.recovery_cp = 0;
136
137 for (i = 0; i < raid_devs; i++)
138 md_rdev_init(&rs->dev[i].rdev);
139
140 /*
141 * Remaining items to be initialized by further RAID params:
142 * rs->md.persistent
143 * rs->md.external
144 * rs->md.chunk_sectors
145 * rs->md.new_chunk_sectors
146 */
147
148 return rs;
149 }
150
context_free(struct raid_set * rs)151 static void context_free(struct raid_set *rs)
152 {
153 int i;
154
155 for (i = 0; i < rs->md.raid_disks; i++) {
156 if (rs->dev[i].meta_dev)
157 dm_put_device(rs->ti, rs->dev[i].meta_dev);
158 if (rs->dev[i].rdev.sb_page)
159 put_page(rs->dev[i].rdev.sb_page);
160 rs->dev[i].rdev.sb_page = NULL;
161 rs->dev[i].rdev.sb_loaded = 0;
162 if (rs->dev[i].data_dev)
163 dm_put_device(rs->ti, rs->dev[i].data_dev);
164 }
165
166 kfree(rs);
167 }
168
169 /*
170 * For every device we have two words
171 * <meta_dev>: meta device name or '-' if missing
172 * <data_dev>: data device name or '-' if missing
173 *
174 * The following are permitted:
175 * - -
176 * - <data_dev>
177 * <meta_dev> <data_dev>
178 *
179 * The following is not allowed:
180 * <meta_dev> -
181 *
182 * This code parses those words. If there is a failure,
183 * the caller must use context_free to unwind the operations.
184 */
dev_parms(struct raid_set * rs,char ** argv)185 static int dev_parms(struct raid_set *rs, char **argv)
186 {
187 int i;
188 int rebuild = 0;
189 int metadata_available = 0;
190 int ret = 0;
191
192 for (i = 0; i < rs->md.raid_disks; i++, argv += 2) {
193 rs->dev[i].rdev.raid_disk = i;
194
195 rs->dev[i].meta_dev = NULL;
196 rs->dev[i].data_dev = NULL;
197
198 /*
199 * There are no offsets, since there is a separate device
200 * for data and metadata.
201 */
202 rs->dev[i].rdev.data_offset = 0;
203 rs->dev[i].rdev.mddev = &rs->md;
204
205 if (strcmp(argv[0], "-")) {
206 ret = dm_get_device(rs->ti, argv[0],
207 dm_table_get_mode(rs->ti->table),
208 &rs->dev[i].meta_dev);
209 rs->ti->error = "RAID metadata device lookup failure";
210 if (ret)
211 return ret;
212
213 rs->dev[i].rdev.sb_page = alloc_page(GFP_KERNEL);
214 if (!rs->dev[i].rdev.sb_page)
215 return -ENOMEM;
216 }
217
218 if (!strcmp(argv[1], "-")) {
219 if (!test_bit(In_sync, &rs->dev[i].rdev.flags) &&
220 (!rs->dev[i].rdev.recovery_offset)) {
221 rs->ti->error = "Drive designated for rebuild not specified";
222 return -EINVAL;
223 }
224
225 rs->ti->error = "No data device supplied with metadata device";
226 if (rs->dev[i].meta_dev)
227 return -EINVAL;
228
229 continue;
230 }
231
232 ret = dm_get_device(rs->ti, argv[1],
233 dm_table_get_mode(rs->ti->table),
234 &rs->dev[i].data_dev);
235 if (ret) {
236 rs->ti->error = "RAID device lookup failure";
237 return ret;
238 }
239
240 if (rs->dev[i].meta_dev) {
241 metadata_available = 1;
242 rs->dev[i].rdev.meta_bdev = rs->dev[i].meta_dev->bdev;
243 }
244 rs->dev[i].rdev.bdev = rs->dev[i].data_dev->bdev;
245 list_add(&rs->dev[i].rdev.same_set, &rs->md.disks);
246 if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
247 rebuild++;
248 }
249
250 if (metadata_available) {
251 rs->md.external = 0;
252 rs->md.persistent = 1;
253 rs->md.major_version = 2;
254 } else if (rebuild && !rs->md.recovery_cp) {
255 /*
256 * Without metadata, we will not be able to tell if the array
257 * is in-sync or not - we must assume it is not. Therefore,
258 * it is impossible to rebuild a drive.
259 *
260 * Even if there is metadata, the on-disk information may
261 * indicate that the array is not in-sync and it will then
262 * fail at that time.
263 *
264 * User could specify 'nosync' option if desperate.
265 */
266 DMERR("Unable to rebuild drive while array is not in-sync");
267 rs->ti->error = "RAID device lookup failure";
268 return -EINVAL;
269 }
270
271 return 0;
272 }
273
274 /*
275 * validate_region_size
276 * @rs
277 * @region_size: region size in sectors. If 0, pick a size (4MiB default).
278 *
279 * Set rs->md.bitmap_info.chunksize (which really refers to 'region size').
280 * Ensure that (ti->len/region_size < 2^21) - required by MD bitmap.
281 *
282 * Returns: 0 on success, -EINVAL on failure.
283 */
validate_region_size(struct raid_set * rs,unsigned long region_size)284 static int validate_region_size(struct raid_set *rs, unsigned long region_size)
285 {
286 unsigned long min_region_size = rs->ti->len / (1 << 21);
287
288 if (!region_size) {
289 /*
290 * Choose a reasonable default. All figures in sectors.
291 */
292 if (min_region_size > (1 << 13)) {
293 DMINFO("Choosing default region size of %lu sectors",
294 region_size);
295 region_size = min_region_size;
296 } else {
297 DMINFO("Choosing default region size of 4MiB");
298 region_size = 1 << 13; /* sectors */
299 }
300 } else {
301 /*
302 * Validate user-supplied value.
303 */
304 if (region_size > rs->ti->len) {
305 rs->ti->error = "Supplied region size is too large";
306 return -EINVAL;
307 }
308
309 if (region_size < min_region_size) {
310 DMERR("Supplied region_size (%lu sectors) below minimum (%lu)",
311 region_size, min_region_size);
312 rs->ti->error = "Supplied region size is too small";
313 return -EINVAL;
314 }
315
316 if (!is_power_of_2(region_size)) {
317 rs->ti->error = "Region size is not a power of 2";
318 return -EINVAL;
319 }
320
321 if (region_size < rs->md.chunk_sectors) {
322 rs->ti->error = "Region size is smaller than the chunk size";
323 return -EINVAL;
324 }
325 }
326
327 /*
328 * Convert sectors to bytes.
329 */
330 rs->md.bitmap_info.chunksize = (region_size << 9);
331
332 return 0;
333 }
334
335 /*
336 * Possible arguments are...
337 * <chunk_size> [optional_args]
338 *
339 * Argument definitions
340 * <chunk_size> The number of sectors per disk that
341 * will form the "stripe"
342 * [[no]sync] Force or prevent recovery of the
343 * entire array
344 * [rebuild <idx>] Rebuild the drive indicated by the index
345 * [daemon_sleep <ms>] Time between bitmap daemon work to
346 * clear bits
347 * [min_recovery_rate <kB/sec/disk>] Throttle RAID initialization
348 * [max_recovery_rate <kB/sec/disk>] Throttle RAID initialization
349 * [write_mostly <idx>] Indicate a write mostly drive via index
350 * [max_write_behind <sectors>] See '-write-behind=' (man mdadm)
351 * [stripe_cache <sectors>] Stripe cache size for higher RAIDs
352 * [region_size <sectors>] Defines granularity of bitmap
353 */
parse_raid_params(struct raid_set * rs,char ** argv,unsigned num_raid_params)354 static int parse_raid_params(struct raid_set *rs, char **argv,
355 unsigned num_raid_params)
356 {
357 unsigned i, rebuild_cnt = 0;
358 unsigned long value, region_size = 0;
359 char *key;
360
361 /*
362 * First, parse the in-order required arguments
363 * "chunk_size" is the only argument of this type.
364 */
365 if ((strict_strtoul(argv[0], 10, &value) < 0)) {
366 rs->ti->error = "Bad chunk size";
367 return -EINVAL;
368 } else if (rs->raid_type->level == 1) {
369 if (value)
370 DMERR("Ignoring chunk size parameter for RAID 1");
371 value = 0;
372 } else if (!is_power_of_2(value)) {
373 rs->ti->error = "Chunk size must be a power of 2";
374 return -EINVAL;
375 } else if (value < 8) {
376 rs->ti->error = "Chunk size value is too small";
377 return -EINVAL;
378 }
379
380 rs->md.new_chunk_sectors = rs->md.chunk_sectors = value;
381 argv++;
382 num_raid_params--;
383
384 /*
385 * We set each individual device as In_sync with a completed
386 * 'recovery_offset'. If there has been a device failure or
387 * replacement then one of the following cases applies:
388 *
389 * 1) User specifies 'rebuild'.
390 * - Device is reset when param is read.
391 * 2) A new device is supplied.
392 * - No matching superblock found, resets device.
393 * 3) Device failure was transient and returns on reload.
394 * - Failure noticed, resets device for bitmap replay.
395 * 4) Device hadn't completed recovery after previous failure.
396 * - Superblock is read and overrides recovery_offset.
397 *
398 * What is found in the superblocks of the devices is always
399 * authoritative, unless 'rebuild' or '[no]sync' was specified.
400 */
401 for (i = 0; i < rs->md.raid_disks; i++) {
402 set_bit(In_sync, &rs->dev[i].rdev.flags);
403 rs->dev[i].rdev.recovery_offset = MaxSector;
404 }
405
406 /*
407 * Second, parse the unordered optional arguments
408 */
409 for (i = 0; i < num_raid_params; i++) {
410 if (!strcasecmp(argv[i], "nosync")) {
411 rs->md.recovery_cp = MaxSector;
412 rs->print_flags |= DMPF_NOSYNC;
413 continue;
414 }
415 if (!strcasecmp(argv[i], "sync")) {
416 rs->md.recovery_cp = 0;
417 rs->print_flags |= DMPF_SYNC;
418 continue;
419 }
420
421 /* The rest of the optional arguments come in key/value pairs */
422 if ((i + 1) >= num_raid_params) {
423 rs->ti->error = "Wrong number of raid parameters given";
424 return -EINVAL;
425 }
426
427 key = argv[i++];
428 if (strict_strtoul(argv[i], 10, &value) < 0) {
429 rs->ti->error = "Bad numerical argument given in raid params";
430 return -EINVAL;
431 }
432
433 if (!strcasecmp(key, "rebuild")) {
434 rebuild_cnt++;
435 if (((rs->raid_type->level != 1) &&
436 (rebuild_cnt > rs->raid_type->parity_devs)) ||
437 ((rs->raid_type->level == 1) &&
438 (rebuild_cnt > (rs->md.raid_disks - 1)))) {
439 rs->ti->error = "Too many rebuild devices specified for given RAID type";
440 return -EINVAL;
441 }
442 if (value > rs->md.raid_disks) {
443 rs->ti->error = "Invalid rebuild index given";
444 return -EINVAL;
445 }
446 clear_bit(In_sync, &rs->dev[value].rdev.flags);
447 rs->dev[value].rdev.recovery_offset = 0;
448 rs->print_flags |= DMPF_REBUILD;
449 } else if (!strcasecmp(key, "write_mostly")) {
450 if (rs->raid_type->level != 1) {
451 rs->ti->error = "write_mostly option is only valid for RAID1";
452 return -EINVAL;
453 }
454 if (value >= rs->md.raid_disks) {
455 rs->ti->error = "Invalid write_mostly drive index given";
456 return -EINVAL;
457 }
458 set_bit(WriteMostly, &rs->dev[value].rdev.flags);
459 } else if (!strcasecmp(key, "max_write_behind")) {
460 if (rs->raid_type->level != 1) {
461 rs->ti->error = "max_write_behind option is only valid for RAID1";
462 return -EINVAL;
463 }
464 rs->print_flags |= DMPF_MAX_WRITE_BEHIND;
465
466 /*
467 * In device-mapper, we specify things in sectors, but
468 * MD records this value in kB
469 */
470 value /= 2;
471 if (value > COUNTER_MAX) {
472 rs->ti->error = "Max write-behind limit out of range";
473 return -EINVAL;
474 }
475 rs->md.bitmap_info.max_write_behind = value;
476 } else if (!strcasecmp(key, "daemon_sleep")) {
477 rs->print_flags |= DMPF_DAEMON_SLEEP;
478 if (!value || (value > MAX_SCHEDULE_TIMEOUT)) {
479 rs->ti->error = "daemon sleep period out of range";
480 return -EINVAL;
481 }
482 rs->md.bitmap_info.daemon_sleep = value;
483 } else if (!strcasecmp(key, "stripe_cache")) {
484 rs->print_flags |= DMPF_STRIPE_CACHE;
485
486 /*
487 * In device-mapper, we specify things in sectors, but
488 * MD records this value in kB
489 */
490 value /= 2;
491
492 if (rs->raid_type->level < 5) {
493 rs->ti->error = "Inappropriate argument: stripe_cache";
494 return -EINVAL;
495 }
496 if (raid5_set_cache_size(&rs->md, (int)value)) {
497 rs->ti->error = "Bad stripe_cache size";
498 return -EINVAL;
499 }
500 } else if (!strcasecmp(key, "min_recovery_rate")) {
501 rs->print_flags |= DMPF_MIN_RECOVERY_RATE;
502 if (value > INT_MAX) {
503 rs->ti->error = "min_recovery_rate out of range";
504 return -EINVAL;
505 }
506 rs->md.sync_speed_min = (int)value;
507 } else if (!strcasecmp(key, "max_recovery_rate")) {
508 rs->print_flags |= DMPF_MAX_RECOVERY_RATE;
509 if (value > INT_MAX) {
510 rs->ti->error = "max_recovery_rate out of range";
511 return -EINVAL;
512 }
513 rs->md.sync_speed_max = (int)value;
514 } else if (!strcasecmp(key, "region_size")) {
515 rs->print_flags |= DMPF_REGION_SIZE;
516 region_size = value;
517 } else {
518 DMERR("Unable to parse RAID parameter: %s", key);
519 rs->ti->error = "Unable to parse RAID parameters";
520 return -EINVAL;
521 }
522 }
523
524 if (validate_region_size(rs, region_size))
525 return -EINVAL;
526
527 if (rs->md.chunk_sectors)
528 rs->ti->split_io = rs->md.chunk_sectors;
529 else
530 rs->ti->split_io = region_size;
531
532 if (rs->md.chunk_sectors)
533 rs->ti->split_io = rs->md.chunk_sectors;
534 else
535 rs->ti->split_io = region_size;
536
537 /* Assume there are no metadata devices until the drives are parsed */
538 rs->md.persistent = 0;
539 rs->md.external = 1;
540
541 return 0;
542 }
543
do_table_event(struct work_struct * ws)544 static void do_table_event(struct work_struct *ws)
545 {
546 struct raid_set *rs = container_of(ws, struct raid_set, md.event_work);
547
548 dm_table_event(rs->ti->table);
549 }
550
raid_is_congested(struct dm_target_callbacks * cb,int bits)551 static int raid_is_congested(struct dm_target_callbacks *cb, int bits)
552 {
553 struct raid_set *rs = container_of(cb, struct raid_set, callbacks);
554
555 if (rs->raid_type->level == 1)
556 return md_raid1_congested(&rs->md, bits);
557
558 return md_raid5_congested(&rs->md, bits);
559 }
560
561 /*
562 * This structure is never routinely used by userspace, unlike md superblocks.
563 * Devices with this superblock should only ever be accessed via device-mapper.
564 */
565 #define DM_RAID_MAGIC 0x64526D44
566 struct dm_raid_superblock {
567 __le32 magic; /* "DmRd" */
568 __le32 features; /* Used to indicate possible future changes */
569
570 __le32 num_devices; /* Number of devices in this array. (Max 64) */
571 __le32 array_position; /* The position of this drive in the array */
572
573 __le64 events; /* Incremented by md when superblock updated */
574 __le64 failed_devices; /* Bit field of devices to indicate failures */
575
576 /*
577 * This offset tracks the progress of the repair or replacement of
578 * an individual drive.
579 */
580 __le64 disk_recovery_offset;
581
582 /*
583 * This offset tracks the progress of the initial array
584 * synchronisation/parity calculation.
585 */
586 __le64 array_resync_offset;
587
588 /*
589 * RAID characteristics
590 */
591 __le32 level;
592 __le32 layout;
593 __le32 stripe_sectors;
594
595 __u8 pad[452]; /* Round struct to 512 bytes. */
596 /* Always set to 0 when writing. */
597 } __packed;
598
read_disk_sb(struct md_rdev * rdev,int size)599 static int read_disk_sb(struct md_rdev *rdev, int size)
600 {
601 BUG_ON(!rdev->sb_page);
602
603 if (rdev->sb_loaded)
604 return 0;
605
606 if (!sync_page_io(rdev, 0, size, rdev->sb_page, READ, 1)) {
607 DMERR("Failed to read device superblock");
608 return -EINVAL;
609 }
610
611 rdev->sb_loaded = 1;
612
613 return 0;
614 }
615
super_sync(struct mddev * mddev,struct md_rdev * rdev)616 static void super_sync(struct mddev *mddev, struct md_rdev *rdev)
617 {
618 struct md_rdev *r, *t;
619 uint64_t failed_devices;
620 struct dm_raid_superblock *sb;
621
622 sb = page_address(rdev->sb_page);
623 failed_devices = le64_to_cpu(sb->failed_devices);
624
625 rdev_for_each(r, t, mddev)
626 if ((r->raid_disk >= 0) && test_bit(Faulty, &r->flags))
627 failed_devices |= (1ULL << r->raid_disk);
628
629 memset(sb, 0, sizeof(*sb));
630
631 sb->magic = cpu_to_le32(DM_RAID_MAGIC);
632 sb->features = cpu_to_le32(0); /* No features yet */
633
634 sb->num_devices = cpu_to_le32(mddev->raid_disks);
635 sb->array_position = cpu_to_le32(rdev->raid_disk);
636
637 sb->events = cpu_to_le64(mddev->events);
638 sb->failed_devices = cpu_to_le64(failed_devices);
639
640 sb->disk_recovery_offset = cpu_to_le64(rdev->recovery_offset);
641 sb->array_resync_offset = cpu_to_le64(mddev->recovery_cp);
642
643 sb->level = cpu_to_le32(mddev->level);
644 sb->layout = cpu_to_le32(mddev->layout);
645 sb->stripe_sectors = cpu_to_le32(mddev->chunk_sectors);
646 }
647
648 /*
649 * super_load
650 *
651 * This function creates a superblock if one is not found on the device
652 * and will decide which superblock to use if there's a choice.
653 *
654 * Return: 1 if use rdev, 0 if use refdev, -Exxx otherwise
655 */
super_load(struct md_rdev * rdev,struct md_rdev * refdev)656 static int super_load(struct md_rdev *rdev, struct md_rdev *refdev)
657 {
658 int ret;
659 struct dm_raid_superblock *sb;
660 struct dm_raid_superblock *refsb;
661 uint64_t events_sb, events_refsb;
662
663 rdev->sb_start = 0;
664 rdev->sb_size = sizeof(*sb);
665
666 ret = read_disk_sb(rdev, rdev->sb_size);
667 if (ret)
668 return ret;
669
670 sb = page_address(rdev->sb_page);
671
672 /*
673 * Two cases that we want to write new superblocks and rebuild:
674 * 1) New device (no matching magic number)
675 * 2) Device specified for rebuild (!In_sync w/ offset == 0)
676 */
677 if ((sb->magic != cpu_to_le32(DM_RAID_MAGIC)) ||
678 (!test_bit(In_sync, &rdev->flags) && !rdev->recovery_offset)) {
679 super_sync(rdev->mddev, rdev);
680
681 set_bit(FirstUse, &rdev->flags);
682
683 /* Force writing of superblocks to disk */
684 set_bit(MD_CHANGE_DEVS, &rdev->mddev->flags);
685
686 /* Any superblock is better than none, choose that if given */
687 return refdev ? 0 : 1;
688 }
689
690 if (!refdev)
691 return 1;
692
693 events_sb = le64_to_cpu(sb->events);
694
695 refsb = page_address(refdev->sb_page);
696 events_refsb = le64_to_cpu(refsb->events);
697
698 return (events_sb > events_refsb) ? 1 : 0;
699 }
700
super_init_validation(struct mddev * mddev,struct md_rdev * rdev)701 static int super_init_validation(struct mddev *mddev, struct md_rdev *rdev)
702 {
703 int role;
704 struct raid_set *rs = container_of(mddev, struct raid_set, md);
705 uint64_t events_sb;
706 uint64_t failed_devices;
707 struct dm_raid_superblock *sb;
708 uint32_t new_devs = 0;
709 uint32_t rebuilds = 0;
710 struct md_rdev *r, *t;
711 struct dm_raid_superblock *sb2;
712
713 sb = page_address(rdev->sb_page);
714 events_sb = le64_to_cpu(sb->events);
715 failed_devices = le64_to_cpu(sb->failed_devices);
716
717 /*
718 * Initialise to 1 if this is a new superblock.
719 */
720 mddev->events = events_sb ? : 1;
721
722 /*
723 * Reshaping is not currently allowed
724 */
725 if ((le32_to_cpu(sb->level) != mddev->level) ||
726 (le32_to_cpu(sb->layout) != mddev->layout) ||
727 (le32_to_cpu(sb->stripe_sectors) != mddev->chunk_sectors)) {
728 DMERR("Reshaping arrays not yet supported.");
729 return -EINVAL;
730 }
731
732 /* We can only change the number of devices in RAID1 right now */
733 if ((rs->raid_type->level != 1) &&
734 (le32_to_cpu(sb->num_devices) != mddev->raid_disks)) {
735 DMERR("Reshaping arrays not yet supported.");
736 return -EINVAL;
737 }
738
739 if (!(rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC)))
740 mddev->recovery_cp = le64_to_cpu(sb->array_resync_offset);
741
742 /*
743 * During load, we set FirstUse if a new superblock was written.
744 * There are two reasons we might not have a superblock:
745 * 1) The array is brand new - in which case, all of the
746 * devices must have their In_sync bit set. Also,
747 * recovery_cp must be 0, unless forced.
748 * 2) This is a new device being added to an old array
749 * and the new device needs to be rebuilt - in which
750 * case the In_sync bit will /not/ be set and
751 * recovery_cp must be MaxSector.
752 */
753 rdev_for_each(r, t, mddev) {
754 if (!test_bit(In_sync, &r->flags)) {
755 DMINFO("Device %d specified for rebuild: "
756 "Clearing superblock", r->raid_disk);
757 rebuilds++;
758 } else if (test_bit(FirstUse, &r->flags))
759 new_devs++;
760 }
761
762 if (!rebuilds) {
763 if (new_devs == mddev->raid_disks) {
764 DMINFO("Superblocks created for new array");
765 set_bit(MD_ARRAY_FIRST_USE, &mddev->flags);
766 } else if (new_devs) {
767 DMERR("New device injected "
768 "into existing array without 'rebuild' "
769 "parameter specified");
770 return -EINVAL;
771 }
772 } else if (new_devs) {
773 DMERR("'rebuild' devices cannot be "
774 "injected into an array with other first-time devices");
775 return -EINVAL;
776 } else if (mddev->recovery_cp != MaxSector) {
777 DMERR("'rebuild' specified while array is not in-sync");
778 return -EINVAL;
779 }
780
781 /*
782 * Now we set the Faulty bit for those devices that are
783 * recorded in the superblock as failed.
784 */
785 rdev_for_each(r, t, mddev) {
786 if (!r->sb_page)
787 continue;
788 sb2 = page_address(r->sb_page);
789 sb2->failed_devices = 0;
790
791 /*
792 * Check for any device re-ordering.
793 */
794 if (!test_bit(FirstUse, &r->flags) && (r->raid_disk >= 0)) {
795 role = le32_to_cpu(sb2->array_position);
796 if (role != r->raid_disk) {
797 if (rs->raid_type->level != 1) {
798 rs->ti->error = "Cannot change device "
799 "positions in RAID array";
800 return -EINVAL;
801 }
802 DMINFO("RAID1 device #%d now at position #%d",
803 role, r->raid_disk);
804 }
805
806 /*
807 * Partial recovery is performed on
808 * returning failed devices.
809 */
810 if (failed_devices & (1 << role))
811 set_bit(Faulty, &r->flags);
812 }
813 }
814
815 return 0;
816 }
817
super_validate(struct mddev * mddev,struct md_rdev * rdev)818 static int super_validate(struct mddev *mddev, struct md_rdev *rdev)
819 {
820 struct dm_raid_superblock *sb = page_address(rdev->sb_page);
821
822 /*
823 * If mddev->events is not set, we know we have not yet initialized
824 * the array.
825 */
826 if (!mddev->events && super_init_validation(mddev, rdev))
827 return -EINVAL;
828
829 mddev->bitmap_info.offset = 4096 >> 9; /* Enable bitmap creation */
830 rdev->mddev->bitmap_info.default_offset = 4096 >> 9;
831 if (!test_bit(FirstUse, &rdev->flags)) {
832 rdev->recovery_offset = le64_to_cpu(sb->disk_recovery_offset);
833 if (rdev->recovery_offset != MaxSector)
834 clear_bit(In_sync, &rdev->flags);
835 }
836
837 /*
838 * If a device comes back, set it as not In_sync and no longer faulty.
839 */
840 if (test_bit(Faulty, &rdev->flags)) {
841 clear_bit(Faulty, &rdev->flags);
842 clear_bit(In_sync, &rdev->flags);
843 rdev->saved_raid_disk = rdev->raid_disk;
844 rdev->recovery_offset = 0;
845 }
846
847 clear_bit(FirstUse, &rdev->flags);
848
849 return 0;
850 }
851
852 /*
853 * Analyse superblocks and select the freshest.
854 */
analyse_superblocks(struct dm_target * ti,struct raid_set * rs)855 static int analyse_superblocks(struct dm_target *ti, struct raid_set *rs)
856 {
857 int ret;
858 struct md_rdev *rdev, *freshest, *tmp;
859 struct mddev *mddev = &rs->md;
860
861 freshest = NULL;
862 rdev_for_each(rdev, tmp, mddev) {
863 if (!rdev->meta_bdev)
864 continue;
865
866 ret = super_load(rdev, freshest);
867
868 switch (ret) {
869 case 1:
870 freshest = rdev;
871 break;
872 case 0:
873 break;
874 default:
875 ti->error = "Failed to load superblock";
876 return ret;
877 }
878 }
879
880 if (!freshest)
881 return 0;
882
883 /*
884 * Validation of the freshest device provides the source of
885 * validation for the remaining devices.
886 */
887 ti->error = "Unable to assemble array: Invalid superblocks";
888 if (super_validate(mddev, freshest))
889 return -EINVAL;
890
891 rdev_for_each(rdev, tmp, mddev)
892 if ((rdev != freshest) && super_validate(mddev, rdev))
893 return -EINVAL;
894
895 return 0;
896 }
897
898 /*
899 * Construct a RAID4/5/6 mapping:
900 * Args:
901 * <raid_type> <#raid_params> <raid_params> \
902 * <#raid_devs> { <meta_dev1> <dev1> .. <meta_devN> <devN> }
903 *
904 * <raid_params> varies by <raid_type>. See 'parse_raid_params' for
905 * details on possible <raid_params>.
906 */
raid_ctr(struct dm_target * ti,unsigned argc,char ** argv)907 static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
908 {
909 int ret;
910 struct raid_type *rt;
911 unsigned long num_raid_params, num_raid_devs;
912 struct raid_set *rs = NULL;
913
914 /* Must have at least <raid_type> <#raid_params> */
915 if (argc < 2) {
916 ti->error = "Too few arguments";
917 return -EINVAL;
918 }
919
920 /* raid type */
921 rt = get_raid_type(argv[0]);
922 if (!rt) {
923 ti->error = "Unrecognised raid_type";
924 return -EINVAL;
925 }
926 argc--;
927 argv++;
928
929 /* number of RAID parameters */
930 if (strict_strtoul(argv[0], 10, &num_raid_params) < 0) {
931 ti->error = "Cannot understand number of RAID parameters";
932 return -EINVAL;
933 }
934 argc--;
935 argv++;
936
937 /* Skip over RAID params for now and find out # of devices */
938 if (num_raid_params + 1 > argc) {
939 ti->error = "Arguments do not agree with counts given";
940 return -EINVAL;
941 }
942
943 if ((strict_strtoul(argv[num_raid_params], 10, &num_raid_devs) < 0) ||
944 (num_raid_devs >= INT_MAX)) {
945 ti->error = "Cannot understand number of raid devices";
946 return -EINVAL;
947 }
948
949 rs = context_alloc(ti, rt, (unsigned)num_raid_devs);
950 if (IS_ERR(rs))
951 return PTR_ERR(rs);
952
953 ret = parse_raid_params(rs, argv, (unsigned)num_raid_params);
954 if (ret)
955 goto bad;
956
957 ret = -EINVAL;
958
959 argc -= num_raid_params + 1; /* +1: we already have num_raid_devs */
960 argv += num_raid_params + 1;
961
962 if (argc != (num_raid_devs * 2)) {
963 ti->error = "Supplied RAID devices does not match the count given";
964 goto bad;
965 }
966
967 ret = dev_parms(rs, argv);
968 if (ret)
969 goto bad;
970
971 rs->md.sync_super = super_sync;
972 ret = analyse_superblocks(ti, rs);
973 if (ret)
974 goto bad;
975
976 INIT_WORK(&rs->md.event_work, do_table_event);
977 ti->private = rs;
978 ti->num_flush_requests = 1;
979
980 mutex_lock(&rs->md.reconfig_mutex);
981 ret = md_run(&rs->md);
982 rs->md.in_sync = 0; /* Assume already marked dirty */
983 mutex_unlock(&rs->md.reconfig_mutex);
984
985 if (ret) {
986 ti->error = "Fail to run raid array";
987 goto bad;
988 }
989
990 rs->callbacks.congested_fn = raid_is_congested;
991 dm_table_add_target_callbacks(ti->table, &rs->callbacks);
992
993 mddev_suspend(&rs->md);
994 return 0;
995
996 bad:
997 context_free(rs);
998
999 return ret;
1000 }
1001
raid_dtr(struct dm_target * ti)1002 static void raid_dtr(struct dm_target *ti)
1003 {
1004 struct raid_set *rs = ti->private;
1005
1006 list_del_init(&rs->callbacks.list);
1007 md_stop(&rs->md);
1008 context_free(rs);
1009 }
1010
raid_map(struct dm_target * ti,struct bio * bio,union map_info * map_context)1011 static int raid_map(struct dm_target *ti, struct bio *bio, union map_info *map_context)
1012 {
1013 struct raid_set *rs = ti->private;
1014 struct mddev *mddev = &rs->md;
1015
1016 mddev->pers->make_request(mddev, bio);
1017
1018 return DM_MAPIO_SUBMITTED;
1019 }
1020
raid_status(struct dm_target * ti,status_type_t type,char * result,unsigned maxlen)1021 static int raid_status(struct dm_target *ti, status_type_t type,
1022 char *result, unsigned maxlen)
1023 {
1024 struct raid_set *rs = ti->private;
1025 unsigned raid_param_cnt = 1; /* at least 1 for chunksize */
1026 unsigned sz = 0;
1027 int i, array_in_sync = 0;
1028 sector_t sync;
1029
1030 switch (type) {
1031 case STATUSTYPE_INFO:
1032 DMEMIT("%s %d ", rs->raid_type->name, rs->md.raid_disks);
1033
1034 if (test_bit(MD_RECOVERY_RUNNING, &rs->md.recovery))
1035 sync = rs->md.curr_resync_completed;
1036 else
1037 sync = rs->md.recovery_cp;
1038
1039 if (sync >= rs->md.resync_max_sectors) {
1040 array_in_sync = 1;
1041 sync = rs->md.resync_max_sectors;
1042 } else {
1043 /*
1044 * The array may be doing an initial sync, or it may
1045 * be rebuilding individual components. If all the
1046 * devices are In_sync, then it is the array that is
1047 * being initialized.
1048 */
1049 for (i = 0; i < rs->md.raid_disks; i++)
1050 if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
1051 array_in_sync = 1;
1052 }
1053 /*
1054 * Status characters:
1055 * 'D' = Dead/Failed device
1056 * 'a' = Alive but not in-sync
1057 * 'A' = Alive and in-sync
1058 */
1059 for (i = 0; i < rs->md.raid_disks; i++) {
1060 if (test_bit(Faulty, &rs->dev[i].rdev.flags))
1061 DMEMIT("D");
1062 else if (!array_in_sync ||
1063 !test_bit(In_sync, &rs->dev[i].rdev.flags))
1064 DMEMIT("a");
1065 else
1066 DMEMIT("A");
1067 }
1068
1069 /*
1070 * In-sync ratio:
1071 * The in-sync ratio shows the progress of:
1072 * - Initializing the array
1073 * - Rebuilding a subset of devices of the array
1074 * The user can distinguish between the two by referring
1075 * to the status characters.
1076 */
1077 DMEMIT(" %llu/%llu",
1078 (unsigned long long) sync,
1079 (unsigned long long) rs->md.resync_max_sectors);
1080
1081 break;
1082 case STATUSTYPE_TABLE:
1083 /* The string you would use to construct this array */
1084 for (i = 0; i < rs->md.raid_disks; i++) {
1085 if ((rs->print_flags & DMPF_REBUILD) &&
1086 rs->dev[i].data_dev &&
1087 !test_bit(In_sync, &rs->dev[i].rdev.flags))
1088 raid_param_cnt += 2; /* for rebuilds */
1089 if (rs->dev[i].data_dev &&
1090 test_bit(WriteMostly, &rs->dev[i].rdev.flags))
1091 raid_param_cnt += 2;
1092 }
1093
1094 raid_param_cnt += (hweight32(rs->print_flags & ~DMPF_REBUILD) * 2);
1095 if (rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC))
1096 raid_param_cnt--;
1097
1098 DMEMIT("%s %u %u", rs->raid_type->name,
1099 raid_param_cnt, rs->md.chunk_sectors);
1100
1101 if ((rs->print_flags & DMPF_SYNC) &&
1102 (rs->md.recovery_cp == MaxSector))
1103 DMEMIT(" sync");
1104 if (rs->print_flags & DMPF_NOSYNC)
1105 DMEMIT(" nosync");
1106
1107 for (i = 0; i < rs->md.raid_disks; i++)
1108 if ((rs->print_flags & DMPF_REBUILD) &&
1109 rs->dev[i].data_dev &&
1110 !test_bit(In_sync, &rs->dev[i].rdev.flags))
1111 DMEMIT(" rebuild %u", i);
1112
1113 if (rs->print_flags & DMPF_DAEMON_SLEEP)
1114 DMEMIT(" daemon_sleep %lu",
1115 rs->md.bitmap_info.daemon_sleep);
1116
1117 if (rs->print_flags & DMPF_MIN_RECOVERY_RATE)
1118 DMEMIT(" min_recovery_rate %d", rs->md.sync_speed_min);
1119
1120 if (rs->print_flags & DMPF_MAX_RECOVERY_RATE)
1121 DMEMIT(" max_recovery_rate %d", rs->md.sync_speed_max);
1122
1123 for (i = 0; i < rs->md.raid_disks; i++)
1124 if (rs->dev[i].data_dev &&
1125 test_bit(WriteMostly, &rs->dev[i].rdev.flags))
1126 DMEMIT(" write_mostly %u", i);
1127
1128 if (rs->print_flags & DMPF_MAX_WRITE_BEHIND)
1129 DMEMIT(" max_write_behind %lu",
1130 rs->md.bitmap_info.max_write_behind);
1131
1132 if (rs->print_flags & DMPF_STRIPE_CACHE) {
1133 struct r5conf *conf = rs->md.private;
1134
1135 /* convert from kiB to sectors */
1136 DMEMIT(" stripe_cache %d",
1137 conf ? conf->max_nr_stripes * 2 : 0);
1138 }
1139
1140 if (rs->print_flags & DMPF_REGION_SIZE)
1141 DMEMIT(" region_size %lu",
1142 rs->md.bitmap_info.chunksize >> 9);
1143
1144 DMEMIT(" %d", rs->md.raid_disks);
1145 for (i = 0; i < rs->md.raid_disks; i++) {
1146 if (rs->dev[i].meta_dev)
1147 DMEMIT(" %s", rs->dev[i].meta_dev->name);
1148 else
1149 DMEMIT(" -");
1150
1151 if (rs->dev[i].data_dev)
1152 DMEMIT(" %s", rs->dev[i].data_dev->name);
1153 else
1154 DMEMIT(" -");
1155 }
1156 }
1157
1158 return 0;
1159 }
1160
raid_iterate_devices(struct dm_target * ti,iterate_devices_callout_fn fn,void * data)1161 static int raid_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data)
1162 {
1163 struct raid_set *rs = ti->private;
1164 unsigned i;
1165 int ret = 0;
1166
1167 for (i = 0; !ret && i < rs->md.raid_disks; i++)
1168 if (rs->dev[i].data_dev)
1169 ret = fn(ti,
1170 rs->dev[i].data_dev,
1171 0, /* No offset on data devs */
1172 rs->md.dev_sectors,
1173 data);
1174
1175 return ret;
1176 }
1177
raid_io_hints(struct dm_target * ti,struct queue_limits * limits)1178 static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
1179 {
1180 struct raid_set *rs = ti->private;
1181 unsigned chunk_size = rs->md.chunk_sectors << 9;
1182 struct r5conf *conf = rs->md.private;
1183
1184 blk_limits_io_min(limits, chunk_size);
1185 blk_limits_io_opt(limits, chunk_size * (conf->raid_disks - conf->max_degraded));
1186 }
1187
raid_presuspend(struct dm_target * ti)1188 static void raid_presuspend(struct dm_target *ti)
1189 {
1190 struct raid_set *rs = ti->private;
1191
1192 md_stop_writes(&rs->md);
1193 }
1194
raid_postsuspend(struct dm_target * ti)1195 static void raid_postsuspend(struct dm_target *ti)
1196 {
1197 struct raid_set *rs = ti->private;
1198
1199 mddev_suspend(&rs->md);
1200 }
1201
raid_resume(struct dm_target * ti)1202 static void raid_resume(struct dm_target *ti)
1203 {
1204 struct raid_set *rs = ti->private;
1205
1206 if (!rs->bitmap_loaded) {
1207 bitmap_load(&rs->md);
1208 rs->bitmap_loaded = 1;
1209 } else
1210 md_wakeup_thread(rs->md.thread);
1211
1212 mddev_resume(&rs->md);
1213 }
1214
1215 static struct target_type raid_target = {
1216 .name = "raid",
1217 .version = {1, 1, 0},
1218 .module = THIS_MODULE,
1219 .ctr = raid_ctr,
1220 .dtr = raid_dtr,
1221 .map = raid_map,
1222 .status = raid_status,
1223 .iterate_devices = raid_iterate_devices,
1224 .io_hints = raid_io_hints,
1225 .presuspend = raid_presuspend,
1226 .postsuspend = raid_postsuspend,
1227 .resume = raid_resume,
1228 };
1229
dm_raid_init(void)1230 static int __init dm_raid_init(void)
1231 {
1232 return dm_register_target(&raid_target);
1233 }
1234
dm_raid_exit(void)1235 static void __exit dm_raid_exit(void)
1236 {
1237 dm_unregister_target(&raid_target);
1238 }
1239
1240 module_init(dm_raid_init);
1241 module_exit(dm_raid_exit);
1242
1243 MODULE_DESCRIPTION(DM_NAME " raid4/5/6 target");
1244 MODULE_ALIAS("dm-raid4");
1245 MODULE_ALIAS("dm-raid5");
1246 MODULE_ALIAS("dm-raid6");
1247 MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>");
1248 MODULE_LICENSE("GPL");
1249