Merge branch 'apei' into apei-release
[~shefty/rdma-dev.git] / drivers / md / dm-raid.c
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 "raid5.h"
12 #include "dm.h"
13 #include "bitmap.h"
14
15 #define DM_MSG_PREFIX "raid"
16
17 /*
18  * If the MD doesn't support MD_SYNC_STATE_FORCED yet, then
19  * make it so the flag doesn't set anything.
20  */
21 #ifndef MD_SYNC_STATE_FORCED
22 #define MD_SYNC_STATE_FORCED 0
23 #endif
24
25 struct 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_DAEMON_SLEEP      0x1
47 #define DMPF_MAX_WRITE_BEHIND  0x2
48 #define DMPF_SYNC              0x4
49 #define DMPF_NOSYNC            0x8
50 #define DMPF_STRIPE_CACHE      0x10
51 #define DMPF_MIN_RECOVERY_RATE 0x20
52 #define DMPF_MAX_RECOVERY_RATE 0x40
53
54 struct raid_set {
55         struct dm_target *ti;
56
57         uint64_t print_flags;
58
59         struct mddev_s md;
60         struct raid_type *raid_type;
61         struct dm_target_callbacks callbacks;
62
63         struct raid_dev dev[0];
64 };
65
66 /* Supported raid types and properties. */
67 static struct raid_type {
68         const char *name;               /* RAID algorithm. */
69         const char *descr;              /* Descriptor text for logging. */
70         const unsigned parity_devs;     /* # of parity devices. */
71         const unsigned minimal_devs;    /* minimal # of devices in set. */
72         const unsigned level;           /* RAID level. */
73         const unsigned algorithm;       /* RAID algorithm. */
74 } raid_types[] = {
75         {"raid4",    "RAID4 (dedicated parity disk)",   1, 2, 5, ALGORITHM_PARITY_0},
76         {"raid5_la", "RAID5 (left asymmetric)",         1, 2, 5, ALGORITHM_LEFT_ASYMMETRIC},
77         {"raid5_ra", "RAID5 (right asymmetric)",        1, 2, 5, ALGORITHM_RIGHT_ASYMMETRIC},
78         {"raid5_ls", "RAID5 (left symmetric)",          1, 2, 5, ALGORITHM_LEFT_SYMMETRIC},
79         {"raid5_rs", "RAID5 (right symmetric)",         1, 2, 5, ALGORITHM_RIGHT_SYMMETRIC},
80         {"raid6_zr", "RAID6 (zero restart)",            2, 4, 6, ALGORITHM_ROTATING_ZERO_RESTART},
81         {"raid6_nr", "RAID6 (N restart)",               2, 4, 6, ALGORITHM_ROTATING_N_RESTART},
82         {"raid6_nc", "RAID6 (N continue)",              2, 4, 6, ALGORITHM_ROTATING_N_CONTINUE}
83 };
84
85 static struct raid_type *get_raid_type(char *name)
86 {
87         int i;
88
89         for (i = 0; i < ARRAY_SIZE(raid_types); i++)
90                 if (!strcmp(raid_types[i].name, name))
91                         return &raid_types[i];
92
93         return NULL;
94 }
95
96 static struct raid_set *context_alloc(struct dm_target *ti, struct raid_type *raid_type, unsigned raid_devs)
97 {
98         unsigned i;
99         struct raid_set *rs;
100         sector_t sectors_per_dev;
101
102         if (raid_devs <= raid_type->parity_devs) {
103                 ti->error = "Insufficient number of devices";
104                 return ERR_PTR(-EINVAL);
105         }
106
107         sectors_per_dev = ti->len;
108         if (sector_div(sectors_per_dev, (raid_devs - raid_type->parity_devs))) {
109                 ti->error = "Target length not divisible by number of data devices";
110                 return ERR_PTR(-EINVAL);
111         }
112
113         rs = kzalloc(sizeof(*rs) + raid_devs * sizeof(rs->dev[0]), GFP_KERNEL);
114         if (!rs) {
115                 ti->error = "Cannot allocate raid context";
116                 return ERR_PTR(-ENOMEM);
117         }
118
119         mddev_init(&rs->md);
120
121         rs->ti = ti;
122         rs->raid_type = raid_type;
123         rs->md.raid_disks = raid_devs;
124         rs->md.level = raid_type->level;
125         rs->md.new_level = rs->md.level;
126         rs->md.dev_sectors = sectors_per_dev;
127         rs->md.layout = raid_type->algorithm;
128         rs->md.new_layout = rs->md.layout;
129         rs->md.delta_disks = 0;
130         rs->md.recovery_cp = 0;
131
132         for (i = 0; i < raid_devs; i++)
133                 md_rdev_init(&rs->dev[i].rdev);
134
135         /*
136          * Remaining items to be initialized by further RAID params:
137          *  rs->md.persistent
138          *  rs->md.external
139          *  rs->md.chunk_sectors
140          *  rs->md.new_chunk_sectors
141          */
142
143         return rs;
144 }
145
146 static void context_free(struct raid_set *rs)
147 {
148         int i;
149
150         for (i = 0; i < rs->md.raid_disks; i++)
151                 if (rs->dev[i].data_dev)
152                         dm_put_device(rs->ti, rs->dev[i].data_dev);
153
154         kfree(rs);
155 }
156
157 /*
158  * For every device we have two words
159  *  <meta_dev>: meta device name or '-' if missing
160  *  <data_dev>: data device name or '-' if missing
161  *
162  * This code parses those words.
163  */
164 static int dev_parms(struct raid_set *rs, char **argv)
165 {
166         int i;
167         int rebuild = 0;
168         int metadata_available = 0;
169         int ret = 0;
170
171         for (i = 0; i < rs->md.raid_disks; i++, argv += 2) {
172                 rs->dev[i].rdev.raid_disk = i;
173
174                 rs->dev[i].meta_dev = NULL;
175                 rs->dev[i].data_dev = NULL;
176
177                 /*
178                  * There are no offsets, since there is a separate device
179                  * for data and metadata.
180                  */
181                 rs->dev[i].rdev.data_offset = 0;
182                 rs->dev[i].rdev.mddev = &rs->md;
183
184                 if (strcmp(argv[0], "-")) {
185                         rs->ti->error = "Metadata devices not supported";
186                         return -EINVAL;
187                 }
188
189                 if (!strcmp(argv[1], "-")) {
190                         if (!test_bit(In_sync, &rs->dev[i].rdev.flags) &&
191                             (!rs->dev[i].rdev.recovery_offset)) {
192                                 rs->ti->error = "Drive designated for rebuild not specified";
193                                 return -EINVAL;
194                         }
195
196                         continue;
197                 }
198
199                 ret = dm_get_device(rs->ti, argv[1],
200                                     dm_table_get_mode(rs->ti->table),
201                                     &rs->dev[i].data_dev);
202                 if (ret) {
203                         rs->ti->error = "RAID device lookup failure";
204                         return ret;
205                 }
206
207                 rs->dev[i].rdev.bdev = rs->dev[i].data_dev->bdev;
208                 list_add(&rs->dev[i].rdev.same_set, &rs->md.disks);
209                 if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
210                         rebuild++;
211         }
212
213         if (metadata_available) {
214                 rs->md.external = 0;
215                 rs->md.persistent = 1;
216                 rs->md.major_version = 2;
217         } else if (rebuild && !rs->md.recovery_cp) {
218                 /*
219                  * Without metadata, we will not be able to tell if the array
220                  * is in-sync or not - we must assume it is not.  Therefore,
221                  * it is impossible to rebuild a drive.
222                  *
223                  * Even if there is metadata, the on-disk information may
224                  * indicate that the array is not in-sync and it will then
225                  * fail at that time.
226                  *
227                  * User could specify 'nosync' option if desperate.
228                  */
229                 DMERR("Unable to rebuild drive while array is not in-sync");
230                 rs->ti->error = "RAID device lookup failure";
231                 return -EINVAL;
232         }
233
234         return 0;
235 }
236
237 /*
238  * Possible arguments are...
239  * RAID456:
240  *      <chunk_size> [optional_args]
241  *
242  * Optional args:
243  *    [[no]sync]                        Force or prevent recovery of the entire array
244  *    [rebuild <idx>]                   Rebuild the drive indicated by the index
245  *    [daemon_sleep <ms>]               Time between bitmap daemon work to clear bits
246  *    [min_recovery_rate <kB/sec/disk>] Throttle RAID initialization
247  *    [max_recovery_rate <kB/sec/disk>] Throttle RAID initialization
248  *    [max_write_behind <sectors>]      See '-write-behind=' (man mdadm)
249  *    [stripe_cache <sectors>]          Stripe cache size for higher RAIDs
250  */
251 static int parse_raid_params(struct raid_set *rs, char **argv,
252                              unsigned num_raid_params)
253 {
254         unsigned i, rebuild_cnt = 0;
255         unsigned long value;
256         char *key;
257
258         /*
259          * First, parse the in-order required arguments
260          */
261         if ((strict_strtoul(argv[0], 10, &value) < 0) ||
262             !is_power_of_2(value) || (value < 8)) {
263                 rs->ti->error = "Bad chunk size";
264                 return -EINVAL;
265         }
266
267         rs->md.new_chunk_sectors = rs->md.chunk_sectors = value;
268         argv++;
269         num_raid_params--;
270
271         /*
272          * Second, parse the unordered optional arguments
273          */
274         for (i = 0; i < rs->md.raid_disks; i++)
275                 set_bit(In_sync, &rs->dev[i].rdev.flags);
276
277         for (i = 0; i < num_raid_params; i++) {
278                 if (!strcmp(argv[i], "nosync")) {
279                         rs->md.recovery_cp = MaxSector;
280                         rs->print_flags |= DMPF_NOSYNC;
281                         rs->md.flags |= MD_SYNC_STATE_FORCED;
282                         continue;
283                 }
284                 if (!strcmp(argv[i], "sync")) {
285                         rs->md.recovery_cp = 0;
286                         rs->print_flags |= DMPF_SYNC;
287                         rs->md.flags |= MD_SYNC_STATE_FORCED;
288                         continue;
289                 }
290
291                 /* The rest of the optional arguments come in key/value pairs */
292                 if ((i + 1) >= num_raid_params) {
293                         rs->ti->error = "Wrong number of raid parameters given";
294                         return -EINVAL;
295                 }
296
297                 key = argv[i++];
298                 if (strict_strtoul(argv[i], 10, &value) < 0) {
299                         rs->ti->error = "Bad numerical argument given in raid params";
300                         return -EINVAL;
301                 }
302
303                 if (!strcmp(key, "rebuild")) {
304                         if (++rebuild_cnt > rs->raid_type->parity_devs) {
305                                 rs->ti->error = "Too many rebuild drives given";
306                                 return -EINVAL;
307                         }
308                         if (value > rs->md.raid_disks) {
309                                 rs->ti->error = "Invalid rebuild index given";
310                                 return -EINVAL;
311                         }
312                         clear_bit(In_sync, &rs->dev[value].rdev.flags);
313                         rs->dev[value].rdev.recovery_offset = 0;
314                 } else if (!strcmp(key, "max_write_behind")) {
315                         rs->print_flags |= DMPF_MAX_WRITE_BEHIND;
316
317                         /*
318                          * In device-mapper, we specify things in sectors, but
319                          * MD records this value in kB
320                          */
321                         value /= 2;
322                         if (value > COUNTER_MAX) {
323                                 rs->ti->error = "Max write-behind limit out of range";
324                                 return -EINVAL;
325                         }
326                         rs->md.bitmap_info.max_write_behind = value;
327                 } else if (!strcmp(key, "daemon_sleep")) {
328                         rs->print_flags |= DMPF_DAEMON_SLEEP;
329                         if (!value || (value > MAX_SCHEDULE_TIMEOUT)) {
330                                 rs->ti->error = "daemon sleep period out of range";
331                                 return -EINVAL;
332                         }
333                         rs->md.bitmap_info.daemon_sleep = value;
334                 } else if (!strcmp(key, "stripe_cache")) {
335                         rs->print_flags |= DMPF_STRIPE_CACHE;
336
337                         /*
338                          * In device-mapper, we specify things in sectors, but
339                          * MD records this value in kB
340                          */
341                         value /= 2;
342
343                         if (rs->raid_type->level < 5) {
344                                 rs->ti->error = "Inappropriate argument: stripe_cache";
345                                 return -EINVAL;
346                         }
347                         if (raid5_set_cache_size(&rs->md, (int)value)) {
348                                 rs->ti->error = "Bad stripe_cache size";
349                                 return -EINVAL;
350                         }
351                 } else if (!strcmp(key, "min_recovery_rate")) {
352                         rs->print_flags |= DMPF_MIN_RECOVERY_RATE;
353                         if (value > INT_MAX) {
354                                 rs->ti->error = "min_recovery_rate out of range";
355                                 return -EINVAL;
356                         }
357                         rs->md.sync_speed_min = (int)value;
358                 } else if (!strcmp(key, "max_recovery_rate")) {
359                         rs->print_flags |= DMPF_MAX_RECOVERY_RATE;
360                         if (value > INT_MAX) {
361                                 rs->ti->error = "max_recovery_rate out of range";
362                                 return -EINVAL;
363                         }
364                         rs->md.sync_speed_max = (int)value;
365                 } else {
366                         DMERR("Unable to parse RAID parameter: %s", key);
367                         rs->ti->error = "Unable to parse RAID parameters";
368                         return -EINVAL;
369                 }
370         }
371
372         /* Assume there are no metadata devices until the drives are parsed */
373         rs->md.persistent = 0;
374         rs->md.external = 1;
375
376         return 0;
377 }
378
379 static void do_table_event(struct work_struct *ws)
380 {
381         struct raid_set *rs = container_of(ws, struct raid_set, md.event_work);
382
383         dm_table_event(rs->ti->table);
384 }
385
386 static int raid_is_congested(struct dm_target_callbacks *cb, int bits)
387 {
388         struct raid_set *rs = container_of(cb, struct raid_set, callbacks);
389
390         return md_raid5_congested(&rs->md, bits);
391 }
392
393 /*
394  * Construct a RAID4/5/6 mapping:
395  * Args:
396  *      <raid_type> <#raid_params> <raid_params>                \
397  *      <#raid_devs> { <meta_dev1> <dev1> .. <meta_devN> <devN> }
398  *
399  * ** metadata devices are not supported yet, use '-' instead **
400  *
401  * <raid_params> varies by <raid_type>.  See 'parse_raid_params' for
402  * details on possible <raid_params>.
403  */
404 static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
405 {
406         int ret;
407         struct raid_type *rt;
408         unsigned long num_raid_params, num_raid_devs;
409         struct raid_set *rs = NULL;
410
411         /* Must have at least <raid_type> <#raid_params> */
412         if (argc < 2) {
413                 ti->error = "Too few arguments";
414                 return -EINVAL;
415         }
416
417         /* raid type */
418         rt = get_raid_type(argv[0]);
419         if (!rt) {
420                 ti->error = "Unrecognised raid_type";
421                 return -EINVAL;
422         }
423         argc--;
424         argv++;
425
426         /* number of RAID parameters */
427         if (strict_strtoul(argv[0], 10, &num_raid_params) < 0) {
428                 ti->error = "Cannot understand number of RAID parameters";
429                 return -EINVAL;
430         }
431         argc--;
432         argv++;
433
434         /* Skip over RAID params for now and find out # of devices */
435         if (num_raid_params + 1 > argc) {
436                 ti->error = "Arguments do not agree with counts given";
437                 return -EINVAL;
438         }
439
440         if ((strict_strtoul(argv[num_raid_params], 10, &num_raid_devs) < 0) ||
441             (num_raid_devs >= INT_MAX)) {
442                 ti->error = "Cannot understand number of raid devices";
443                 return -EINVAL;
444         }
445
446         rs = context_alloc(ti, rt, (unsigned)num_raid_devs);
447         if (IS_ERR(rs))
448                 return PTR_ERR(rs);
449
450         ret = parse_raid_params(rs, argv, (unsigned)num_raid_params);
451         if (ret)
452                 goto bad;
453
454         ret = -EINVAL;
455
456         argc -= num_raid_params + 1; /* +1: we already have num_raid_devs */
457         argv += num_raid_params + 1;
458
459         if (argc != (num_raid_devs * 2)) {
460                 ti->error = "Supplied RAID devices does not match the count given";
461                 goto bad;
462         }
463
464         ret = dev_parms(rs, argv);
465         if (ret)
466                 goto bad;
467
468         INIT_WORK(&rs->md.event_work, do_table_event);
469         ti->split_io = rs->md.chunk_sectors;
470         ti->private = rs;
471
472         mutex_lock(&rs->md.reconfig_mutex);
473         ret = md_run(&rs->md);
474         rs->md.in_sync = 0; /* Assume already marked dirty */
475         mutex_unlock(&rs->md.reconfig_mutex);
476
477         if (ret) {
478                 ti->error = "Fail to run raid array";
479                 goto bad;
480         }
481
482         rs->callbacks.congested_fn = raid_is_congested;
483         dm_table_add_target_callbacks(ti->table, &rs->callbacks);
484
485         return 0;
486
487 bad:
488         context_free(rs);
489
490         return ret;
491 }
492
493 static void raid_dtr(struct dm_target *ti)
494 {
495         struct raid_set *rs = ti->private;
496
497         list_del_init(&rs->callbacks.list);
498         md_stop(&rs->md);
499         context_free(rs);
500 }
501
502 static int raid_map(struct dm_target *ti, struct bio *bio, union map_info *map_context)
503 {
504         struct raid_set *rs = ti->private;
505         mddev_t *mddev = &rs->md;
506
507         mddev->pers->make_request(mddev, bio);
508
509         return DM_MAPIO_SUBMITTED;
510 }
511
512 static int raid_status(struct dm_target *ti, status_type_t type,
513                        char *result, unsigned maxlen)
514 {
515         struct raid_set *rs = ti->private;
516         unsigned raid_param_cnt = 1; /* at least 1 for chunksize */
517         unsigned sz = 0;
518         int i;
519         sector_t sync;
520
521         switch (type) {
522         case STATUSTYPE_INFO:
523                 DMEMIT("%s %d ", rs->raid_type->name, rs->md.raid_disks);
524
525                 for (i = 0; i < rs->md.raid_disks; i++) {
526                         if (test_bit(Faulty, &rs->dev[i].rdev.flags))
527                                 DMEMIT("D");
528                         else if (test_bit(In_sync, &rs->dev[i].rdev.flags))
529                                 DMEMIT("A");
530                         else
531                                 DMEMIT("a");
532                 }
533
534                 if (test_bit(MD_RECOVERY_RUNNING, &rs->md.recovery))
535                         sync = rs->md.curr_resync_completed;
536                 else
537                         sync = rs->md.recovery_cp;
538
539                 if (sync > rs->md.resync_max_sectors)
540                         sync = rs->md.resync_max_sectors;
541
542                 DMEMIT(" %llu/%llu",
543                        (unsigned long long) sync,
544                        (unsigned long long) rs->md.resync_max_sectors);
545
546                 break;
547         case STATUSTYPE_TABLE:
548                 /* The string you would use to construct this array */
549                 for (i = 0; i < rs->md.raid_disks; i++)
550                         if (rs->dev[i].data_dev &&
551                             !test_bit(In_sync, &rs->dev[i].rdev.flags))
552                                 raid_param_cnt++; /* for rebuilds */
553
554                 raid_param_cnt += (hweight64(rs->print_flags) * 2);
555                 if (rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC))
556                         raid_param_cnt--;
557
558                 DMEMIT("%s %u %u", rs->raid_type->name,
559                        raid_param_cnt, rs->md.chunk_sectors);
560
561                 if ((rs->print_flags & DMPF_SYNC) &&
562                     (rs->md.recovery_cp == MaxSector))
563                         DMEMIT(" sync");
564                 if (rs->print_flags & DMPF_NOSYNC)
565                         DMEMIT(" nosync");
566
567                 for (i = 0; i < rs->md.raid_disks; i++)
568                         if (rs->dev[i].data_dev &&
569                             !test_bit(In_sync, &rs->dev[i].rdev.flags))
570                                 DMEMIT(" rebuild %u", i);
571
572                 if (rs->print_flags & DMPF_DAEMON_SLEEP)
573                         DMEMIT(" daemon_sleep %lu",
574                                rs->md.bitmap_info.daemon_sleep);
575
576                 if (rs->print_flags & DMPF_MIN_RECOVERY_RATE)
577                         DMEMIT(" min_recovery_rate %d", rs->md.sync_speed_min);
578
579                 if (rs->print_flags & DMPF_MAX_RECOVERY_RATE)
580                         DMEMIT(" max_recovery_rate %d", rs->md.sync_speed_max);
581
582                 if (rs->print_flags & DMPF_MAX_WRITE_BEHIND)
583                         DMEMIT(" max_write_behind %lu",
584                                rs->md.bitmap_info.max_write_behind);
585
586                 if (rs->print_flags & DMPF_STRIPE_CACHE) {
587                         raid5_conf_t *conf = rs->md.private;
588
589                         /* convert from kiB to sectors */
590                         DMEMIT(" stripe_cache %d",
591                                conf ? conf->max_nr_stripes * 2 : 0);
592                 }
593
594                 DMEMIT(" %d", rs->md.raid_disks);
595                 for (i = 0; i < rs->md.raid_disks; i++) {
596                         DMEMIT(" -"); /* metadata device */
597
598                         if (rs->dev[i].data_dev)
599                                 DMEMIT(" %s", rs->dev[i].data_dev->name);
600                         else
601                                 DMEMIT(" -");
602                 }
603         }
604
605         return 0;
606 }
607
608 static int raid_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data)
609 {
610         struct raid_set *rs = ti->private;
611         unsigned i;
612         int ret = 0;
613
614         for (i = 0; !ret && i < rs->md.raid_disks; i++)
615                 if (rs->dev[i].data_dev)
616                         ret = fn(ti,
617                                  rs->dev[i].data_dev,
618                                  0, /* No offset on data devs */
619                                  rs->md.dev_sectors,
620                                  data);
621
622         return ret;
623 }
624
625 static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
626 {
627         struct raid_set *rs = ti->private;
628         unsigned chunk_size = rs->md.chunk_sectors << 9;
629         raid5_conf_t *conf = rs->md.private;
630
631         blk_limits_io_min(limits, chunk_size);
632         blk_limits_io_opt(limits, chunk_size * (conf->raid_disks - conf->max_degraded));
633 }
634
635 static void raid_presuspend(struct dm_target *ti)
636 {
637         struct raid_set *rs = ti->private;
638
639         md_stop_writes(&rs->md);
640 }
641
642 static void raid_postsuspend(struct dm_target *ti)
643 {
644         struct raid_set *rs = ti->private;
645
646         mddev_suspend(&rs->md);
647 }
648
649 static void raid_resume(struct dm_target *ti)
650 {
651         struct raid_set *rs = ti->private;
652
653         mddev_resume(&rs->md);
654 }
655
656 static struct target_type raid_target = {
657         .name = "raid",
658         .version = {1, 0, 0},
659         .module = THIS_MODULE,
660         .ctr = raid_ctr,
661         .dtr = raid_dtr,
662         .map = raid_map,
663         .status = raid_status,
664         .iterate_devices = raid_iterate_devices,
665         .io_hints = raid_io_hints,
666         .presuspend = raid_presuspend,
667         .postsuspend = raid_postsuspend,
668         .resume = raid_resume,
669 };
670
671 static int __init dm_raid_init(void)
672 {
673         return dm_register_target(&raid_target);
674 }
675
676 static void __exit dm_raid_exit(void)
677 {
678         dm_unregister_target(&raid_target);
679 }
680
681 module_init(dm_raid_init);
682 module_exit(dm_raid_exit);
683
684 MODULE_DESCRIPTION(DM_NAME " raid4/5/6 target");
685 MODULE_ALIAS("dm-raid4");
686 MODULE_ALIAS("dm-raid5");
687 MODULE_ALIAS("dm-raid6");
688 MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>");
689 MODULE_LICENSE("GPL");