Merge tag 'md-3.9' of git://neil.brown.name/md
[~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 #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 /*
22  * The following flags are used by dm-raid.c to set up the array state.
23  * They must be cleared before md_run is called.
24  */
25 #define FirstUse 10             /* rdev flag */
26
27 struct raid_dev {
28         /*
29          * Two DM devices, one to hold metadata and one to hold the
30          * actual data/parity.  The reason for this is to not confuse
31          * ti->len and give more flexibility in altering size and
32          * characteristics.
33          *
34          * While it is possible for this device to be associated
35          * with a different physical device than the data_dev, it
36          * is intended for it to be the same.
37          *    |--------- Physical Device ---------|
38          *    |- meta_dev -|------ data_dev ------|
39          */
40         struct dm_dev *meta_dev;
41         struct dm_dev *data_dev;
42         struct md_rdev rdev;
43 };
44
45 /*
46  * Flags for rs->print_flags field.
47  */
48 #define DMPF_SYNC              0x1
49 #define DMPF_NOSYNC            0x2
50 #define DMPF_REBUILD           0x4
51 #define DMPF_DAEMON_SLEEP      0x8
52 #define DMPF_MIN_RECOVERY_RATE 0x10
53 #define DMPF_MAX_RECOVERY_RATE 0x20
54 #define DMPF_MAX_WRITE_BEHIND  0x40
55 #define DMPF_STRIPE_CACHE      0x80
56 #define DMPF_REGION_SIZE       0x100
57 #define DMPF_RAID10_COPIES     0x200
58 #define DMPF_RAID10_FORMAT     0x400
59
60 struct raid_set {
61         struct dm_target *ti;
62
63         uint32_t bitmap_loaded;
64         uint32_t print_flags;
65
66         struct mddev md;
67         struct raid_type *raid_type;
68         struct dm_target_callbacks callbacks;
69
70         struct raid_dev dev[0];
71 };
72
73 /* Supported raid types and properties. */
74 static struct raid_type {
75         const char *name;               /* RAID algorithm. */
76         const char *descr;              /* Descriptor text for logging. */
77         const unsigned parity_devs;     /* # of parity devices. */
78         const unsigned minimal_devs;    /* minimal # of devices in set. */
79         const unsigned level;           /* RAID level. */
80         const unsigned algorithm;       /* RAID algorithm. */
81 } raid_types[] = {
82         {"raid1",    "RAID1 (mirroring)",               0, 2, 1, 0 /* NONE */},
83         {"raid10",   "RAID10 (striped mirrors)",        0, 2, 10, UINT_MAX /* Varies */},
84         {"raid4",    "RAID4 (dedicated parity disk)",   1, 2, 5, ALGORITHM_PARITY_0},
85         {"raid5_la", "RAID5 (left asymmetric)",         1, 2, 5, ALGORITHM_LEFT_ASYMMETRIC},
86         {"raid5_ra", "RAID5 (right asymmetric)",        1, 2, 5, ALGORITHM_RIGHT_ASYMMETRIC},
87         {"raid5_ls", "RAID5 (left symmetric)",          1, 2, 5, ALGORITHM_LEFT_SYMMETRIC},
88         {"raid5_rs", "RAID5 (right symmetric)",         1, 2, 5, ALGORITHM_RIGHT_SYMMETRIC},
89         {"raid6_zr", "RAID6 (zero restart)",            2, 4, 6, ALGORITHM_ROTATING_ZERO_RESTART},
90         {"raid6_nr", "RAID6 (N restart)",               2, 4, 6, ALGORITHM_ROTATING_N_RESTART},
91         {"raid6_nc", "RAID6 (N continue)",              2, 4, 6, ALGORITHM_ROTATING_N_CONTINUE}
92 };
93
94 static char *raid10_md_layout_to_format(int layout)
95 {
96         /*
97          * Bit 16 and 17 stand for "offset" and "use_far_sets"
98          * Refer to MD's raid10.c for details
99          */
100         if ((layout & 0x10000) && (layout & 0x20000))
101                 return "offset";
102
103         if ((layout & 0xFF) > 1)
104                 return "near";
105
106         return "far";
107 }
108
109 static unsigned raid10_md_layout_to_copies(int layout)
110 {
111         if ((layout & 0xFF) > 1)
112                 return layout & 0xFF;
113         return (layout >> 8) & 0xFF;
114 }
115
116 static int raid10_format_to_md_layout(char *format, unsigned copies)
117 {
118         unsigned n = 1, f = 1;
119
120         if (!strcmp("near", format))
121                 n = copies;
122         else
123                 f = copies;
124
125         if (!strcmp("offset", format))
126                 return 0x30000 | (f << 8) | n;
127
128         if (!strcmp("far", format))
129                 return 0x20000 | (f << 8) | n;
130
131         return (f << 8) | n;
132 }
133
134 static struct raid_type *get_raid_type(char *name)
135 {
136         int i;
137
138         for (i = 0; i < ARRAY_SIZE(raid_types); i++)
139                 if (!strcmp(raid_types[i].name, name))
140                         return &raid_types[i];
141
142         return NULL;
143 }
144
145 static struct raid_set *context_alloc(struct dm_target *ti, struct raid_type *raid_type, unsigned raid_devs)
146 {
147         unsigned i;
148         struct raid_set *rs;
149
150         if (raid_devs <= raid_type->parity_devs) {
151                 ti->error = "Insufficient number of devices";
152                 return ERR_PTR(-EINVAL);
153         }
154
155         rs = kzalloc(sizeof(*rs) + raid_devs * sizeof(rs->dev[0]), GFP_KERNEL);
156         if (!rs) {
157                 ti->error = "Cannot allocate raid context";
158                 return ERR_PTR(-ENOMEM);
159         }
160
161         mddev_init(&rs->md);
162
163         rs->ti = ti;
164         rs->raid_type = raid_type;
165         rs->md.raid_disks = raid_devs;
166         rs->md.level = raid_type->level;
167         rs->md.new_level = rs->md.level;
168         rs->md.layout = raid_type->algorithm;
169         rs->md.new_layout = rs->md.layout;
170         rs->md.delta_disks = 0;
171         rs->md.recovery_cp = 0;
172
173         for (i = 0; i < raid_devs; i++)
174                 md_rdev_init(&rs->dev[i].rdev);
175
176         /*
177          * Remaining items to be initialized by further RAID params:
178          *  rs->md.persistent
179          *  rs->md.external
180          *  rs->md.chunk_sectors
181          *  rs->md.new_chunk_sectors
182          *  rs->md.dev_sectors
183          */
184
185         return rs;
186 }
187
188 static void context_free(struct raid_set *rs)
189 {
190         int i;
191
192         for (i = 0; i < rs->md.raid_disks; i++) {
193                 if (rs->dev[i].meta_dev)
194                         dm_put_device(rs->ti, rs->dev[i].meta_dev);
195                 md_rdev_clear(&rs->dev[i].rdev);
196                 if (rs->dev[i].data_dev)
197                         dm_put_device(rs->ti, rs->dev[i].data_dev);
198         }
199
200         kfree(rs);
201 }
202
203 /*
204  * For every device we have two words
205  *  <meta_dev>: meta device name or '-' if missing
206  *  <data_dev>: data device name or '-' if missing
207  *
208  * The following are permitted:
209  *    - -
210  *    - <data_dev>
211  *    <meta_dev> <data_dev>
212  *
213  * The following is not allowed:
214  *    <meta_dev> -
215  *
216  * This code parses those words.  If there is a failure,
217  * the caller must use context_free to unwind the operations.
218  */
219 static int dev_parms(struct raid_set *rs, char **argv)
220 {
221         int i;
222         int rebuild = 0;
223         int metadata_available = 0;
224         int ret = 0;
225
226         for (i = 0; i < rs->md.raid_disks; i++, argv += 2) {
227                 rs->dev[i].rdev.raid_disk = i;
228
229                 rs->dev[i].meta_dev = NULL;
230                 rs->dev[i].data_dev = NULL;
231
232                 /*
233                  * There are no offsets, since there is a separate device
234                  * for data and metadata.
235                  */
236                 rs->dev[i].rdev.data_offset = 0;
237                 rs->dev[i].rdev.mddev = &rs->md;
238
239                 if (strcmp(argv[0], "-")) {
240                         ret = dm_get_device(rs->ti, argv[0],
241                                             dm_table_get_mode(rs->ti->table),
242                                             &rs->dev[i].meta_dev);
243                         rs->ti->error = "RAID metadata device lookup failure";
244                         if (ret)
245                                 return ret;
246
247                         rs->dev[i].rdev.sb_page = alloc_page(GFP_KERNEL);
248                         if (!rs->dev[i].rdev.sb_page)
249                                 return -ENOMEM;
250                 }
251
252                 if (!strcmp(argv[1], "-")) {
253                         if (!test_bit(In_sync, &rs->dev[i].rdev.flags) &&
254                             (!rs->dev[i].rdev.recovery_offset)) {
255                                 rs->ti->error = "Drive designated for rebuild not specified";
256                                 return -EINVAL;
257                         }
258
259                         rs->ti->error = "No data device supplied with metadata device";
260                         if (rs->dev[i].meta_dev)
261                                 return -EINVAL;
262
263                         continue;
264                 }
265
266                 ret = dm_get_device(rs->ti, argv[1],
267                                     dm_table_get_mode(rs->ti->table),
268                                     &rs->dev[i].data_dev);
269                 if (ret) {
270                         rs->ti->error = "RAID device lookup failure";
271                         return ret;
272                 }
273
274                 if (rs->dev[i].meta_dev) {
275                         metadata_available = 1;
276                         rs->dev[i].rdev.meta_bdev = rs->dev[i].meta_dev->bdev;
277                 }
278                 rs->dev[i].rdev.bdev = rs->dev[i].data_dev->bdev;
279                 list_add(&rs->dev[i].rdev.same_set, &rs->md.disks);
280                 if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
281                         rebuild++;
282         }
283
284         if (metadata_available) {
285                 rs->md.external = 0;
286                 rs->md.persistent = 1;
287                 rs->md.major_version = 2;
288         } else if (rebuild && !rs->md.recovery_cp) {
289                 /*
290                  * Without metadata, we will not be able to tell if the array
291                  * is in-sync or not - we must assume it is not.  Therefore,
292                  * it is impossible to rebuild a drive.
293                  *
294                  * Even if there is metadata, the on-disk information may
295                  * indicate that the array is not in-sync and it will then
296                  * fail at that time.
297                  *
298                  * User could specify 'nosync' option if desperate.
299                  */
300                 DMERR("Unable to rebuild drive while array is not in-sync");
301                 rs->ti->error = "RAID device lookup failure";
302                 return -EINVAL;
303         }
304
305         return 0;
306 }
307
308 /*
309  * validate_region_size
310  * @rs
311  * @region_size:  region size in sectors.  If 0, pick a size (4MiB default).
312  *
313  * Set rs->md.bitmap_info.chunksize (which really refers to 'region size').
314  * Ensure that (ti->len/region_size < 2^21) - required by MD bitmap.
315  *
316  * Returns: 0 on success, -EINVAL on failure.
317  */
318 static int validate_region_size(struct raid_set *rs, unsigned long region_size)
319 {
320         unsigned long min_region_size = rs->ti->len / (1 << 21);
321
322         if (!region_size) {
323                 /*
324                  * Choose a reasonable default.  All figures in sectors.
325                  */
326                 if (min_region_size > (1 << 13)) {
327                         /* If not a power of 2, make it the next power of 2 */
328                         if (min_region_size & (min_region_size - 1))
329                                 region_size = 1 << fls(region_size);
330                         DMINFO("Choosing default region size of %lu sectors",
331                                region_size);
332                 } else {
333                         DMINFO("Choosing default region size of 4MiB");
334                         region_size = 1 << 13; /* sectors */
335                 }
336         } else {
337                 /*
338                  * Validate user-supplied value.
339                  */
340                 if (region_size > rs->ti->len) {
341                         rs->ti->error = "Supplied region size is too large";
342                         return -EINVAL;
343                 }
344
345                 if (region_size < min_region_size) {
346                         DMERR("Supplied region_size (%lu sectors) below minimum (%lu)",
347                               region_size, min_region_size);
348                         rs->ti->error = "Supplied region size is too small";
349                         return -EINVAL;
350                 }
351
352                 if (!is_power_of_2(region_size)) {
353                         rs->ti->error = "Region size is not a power of 2";
354                         return -EINVAL;
355                 }
356
357                 if (region_size < rs->md.chunk_sectors) {
358                         rs->ti->error = "Region size is smaller than the chunk size";
359                         return -EINVAL;
360                 }
361         }
362
363         /*
364          * Convert sectors to bytes.
365          */
366         rs->md.bitmap_info.chunksize = (region_size << 9);
367
368         return 0;
369 }
370
371 /*
372  * validate_raid_redundancy
373  * @rs
374  *
375  * Determine if there are enough devices in the array that haven't
376  * failed (or are being rebuilt) to form a usable array.
377  *
378  * Returns: 0 on success, -EINVAL on failure.
379  */
380 static int validate_raid_redundancy(struct raid_set *rs)
381 {
382         unsigned i, rebuild_cnt = 0;
383         unsigned rebuilds_per_group, copies, d;
384         unsigned group_size, last_group_start;
385
386         for (i = 0; i < rs->md.raid_disks; i++)
387                 if (!test_bit(In_sync, &rs->dev[i].rdev.flags) ||
388                     !rs->dev[i].rdev.sb_page)
389                         rebuild_cnt++;
390
391         switch (rs->raid_type->level) {
392         case 1:
393                 if (rebuild_cnt >= rs->md.raid_disks)
394                         goto too_many;
395                 break;
396         case 4:
397         case 5:
398         case 6:
399                 if (rebuild_cnt > rs->raid_type->parity_devs)
400                         goto too_many;
401                 break;
402         case 10:
403                 copies = raid10_md_layout_to_copies(rs->md.layout);
404                 if (rebuild_cnt < copies)
405                         break;
406
407                 /*
408                  * It is possible to have a higher rebuild count for RAID10,
409                  * as long as the failed devices occur in different mirror
410                  * groups (i.e. different stripes).
411                  *
412                  * When checking "near" format, make sure no adjacent devices
413                  * have failed beyond what can be handled.  In addition to the
414                  * simple case where the number of devices is a multiple of the
415                  * number of copies, we must also handle cases where the number
416                  * of devices is not a multiple of the number of copies.
417                  * E.g.    dev1 dev2 dev3 dev4 dev5
418                  *          A    A    B    B    C
419                  *          C    D    D    E    E
420                  */
421                 if (!strcmp("near", raid10_md_layout_to_format(rs->md.layout))) {
422                         for (i = 0; i < rs->md.raid_disks * copies; i++) {
423                                 if (!(i % copies))
424                                         rebuilds_per_group = 0;
425                                 d = i % rs->md.raid_disks;
426                                 if ((!rs->dev[d].rdev.sb_page ||
427                                      !test_bit(In_sync, &rs->dev[d].rdev.flags)) &&
428                                     (++rebuilds_per_group >= copies))
429                                         goto too_many;
430                         }
431                         break;
432                 }
433
434                 /*
435                  * When checking "far" and "offset" formats, we need to ensure
436                  * that the device that holds its copy is not also dead or
437                  * being rebuilt.  (Note that "far" and "offset" formats only
438                  * support two copies right now.  These formats also only ever
439                  * use the 'use_far_sets' variant.)
440                  *
441                  * This check is somewhat complicated by the need to account
442                  * for arrays that are not a multiple of (far) copies.  This
443                  * results in the need to treat the last (potentially larger)
444                  * set differently.
445                  */
446                 group_size = (rs->md.raid_disks / copies);
447                 last_group_start = (rs->md.raid_disks / group_size) - 1;
448                 last_group_start *= group_size;
449                 for (i = 0; i < rs->md.raid_disks; i++) {
450                         if (!(i % copies) && !(i > last_group_start))
451                                 rebuilds_per_group = 0;
452                         if ((!rs->dev[i].rdev.sb_page ||
453                              !test_bit(In_sync, &rs->dev[i].rdev.flags)) &&
454                             (++rebuilds_per_group >= copies))
455                                         goto too_many;
456                 }
457                 break;
458         default:
459                 if (rebuild_cnt)
460                         return -EINVAL;
461         }
462
463         return 0;
464
465 too_many:
466         return -EINVAL;
467 }
468
469 /*
470  * Possible arguments are...
471  *      <chunk_size> [optional_args]
472  *
473  * Argument definitions
474  *    <chunk_size>                      The number of sectors per disk that
475  *                                      will form the "stripe"
476  *    [[no]sync]                        Force or prevent recovery of the
477  *                                      entire array
478  *    [rebuild <idx>]                   Rebuild the drive indicated by the index
479  *    [daemon_sleep <ms>]               Time between bitmap daemon work to
480  *                                      clear bits
481  *    [min_recovery_rate <kB/sec/disk>] Throttle RAID initialization
482  *    [max_recovery_rate <kB/sec/disk>] Throttle RAID initialization
483  *    [write_mostly <idx>]              Indicate a write mostly drive via index
484  *    [max_write_behind <sectors>]      See '-write-behind=' (man mdadm)
485  *    [stripe_cache <sectors>]          Stripe cache size for higher RAIDs
486  *    [region_size <sectors>]           Defines granularity of bitmap
487  *
488  * RAID10-only options:
489  *    [raid10_copies <# copies>]        Number of copies.  (Default: 2)
490  *    [raid10_format <near|far|offset>] Layout algorithm.  (Default: near)
491  */
492 static int parse_raid_params(struct raid_set *rs, char **argv,
493                              unsigned num_raid_params)
494 {
495         char *raid10_format = "near";
496         unsigned raid10_copies = 2;
497         unsigned i;
498         unsigned long value, region_size = 0;
499         sector_t sectors_per_dev = rs->ti->len;
500         sector_t max_io_len;
501         char *key;
502
503         /*
504          * First, parse the in-order required arguments
505          * "chunk_size" is the only argument of this type.
506          */
507         if ((strict_strtoul(argv[0], 10, &value) < 0)) {
508                 rs->ti->error = "Bad chunk size";
509                 return -EINVAL;
510         } else if (rs->raid_type->level == 1) {
511                 if (value)
512                         DMERR("Ignoring chunk size parameter for RAID 1");
513                 value = 0;
514         } else if (!is_power_of_2(value)) {
515                 rs->ti->error = "Chunk size must be a power of 2";
516                 return -EINVAL;
517         } else if (value < 8) {
518                 rs->ti->error = "Chunk size value is too small";
519                 return -EINVAL;
520         }
521
522         rs->md.new_chunk_sectors = rs->md.chunk_sectors = value;
523         argv++;
524         num_raid_params--;
525
526         /*
527          * We set each individual device as In_sync with a completed
528          * 'recovery_offset'.  If there has been a device failure or
529          * replacement then one of the following cases applies:
530          *
531          *   1) User specifies 'rebuild'.
532          *      - Device is reset when param is read.
533          *   2) A new device is supplied.
534          *      - No matching superblock found, resets device.
535          *   3) Device failure was transient and returns on reload.
536          *      - Failure noticed, resets device for bitmap replay.
537          *   4) Device hadn't completed recovery after previous failure.
538          *      - Superblock is read and overrides recovery_offset.
539          *
540          * What is found in the superblocks of the devices is always
541          * authoritative, unless 'rebuild' or '[no]sync' was specified.
542          */
543         for (i = 0; i < rs->md.raid_disks; i++) {
544                 set_bit(In_sync, &rs->dev[i].rdev.flags);
545                 rs->dev[i].rdev.recovery_offset = MaxSector;
546         }
547
548         /*
549          * Second, parse the unordered optional arguments
550          */
551         for (i = 0; i < num_raid_params; i++) {
552                 if (!strcasecmp(argv[i], "nosync")) {
553                         rs->md.recovery_cp = MaxSector;
554                         rs->print_flags |= DMPF_NOSYNC;
555                         continue;
556                 }
557                 if (!strcasecmp(argv[i], "sync")) {
558                         rs->md.recovery_cp = 0;
559                         rs->print_flags |= DMPF_SYNC;
560                         continue;
561                 }
562
563                 /* The rest of the optional arguments come in key/value pairs */
564                 if ((i + 1) >= num_raid_params) {
565                         rs->ti->error = "Wrong number of raid parameters given";
566                         return -EINVAL;
567                 }
568
569                 key = argv[i++];
570
571                 /* Parameters that take a string value are checked here. */
572                 if (!strcasecmp(key, "raid10_format")) {
573                         if (rs->raid_type->level != 10) {
574                                 rs->ti->error = "'raid10_format' is an invalid parameter for this RAID type";
575                                 return -EINVAL;
576                         }
577                         if (strcmp("near", argv[i]) &&
578                             strcmp("far", argv[i]) &&
579                             strcmp("offset", argv[i])) {
580                                 rs->ti->error = "Invalid 'raid10_format' value given";
581                                 return -EINVAL;
582                         }
583                         raid10_format = argv[i];
584                         rs->print_flags |= DMPF_RAID10_FORMAT;
585                         continue;
586                 }
587
588                 if (strict_strtoul(argv[i], 10, &value) < 0) {
589                         rs->ti->error = "Bad numerical argument given in raid params";
590                         return -EINVAL;
591                 }
592
593                 /* Parameters that take a numeric value are checked here */
594                 if (!strcasecmp(key, "rebuild")) {
595                         if (value >= rs->md.raid_disks) {
596                                 rs->ti->error = "Invalid rebuild index given";
597                                 return -EINVAL;
598                         }
599                         clear_bit(In_sync, &rs->dev[value].rdev.flags);
600                         rs->dev[value].rdev.recovery_offset = 0;
601                         rs->print_flags |= DMPF_REBUILD;
602                 } else if (!strcasecmp(key, "write_mostly")) {
603                         if (rs->raid_type->level != 1) {
604                                 rs->ti->error = "write_mostly option is only valid for RAID1";
605                                 return -EINVAL;
606                         }
607                         if (value >= rs->md.raid_disks) {
608                                 rs->ti->error = "Invalid write_mostly drive index given";
609                                 return -EINVAL;
610                         }
611                         set_bit(WriteMostly, &rs->dev[value].rdev.flags);
612                 } else if (!strcasecmp(key, "max_write_behind")) {
613                         if (rs->raid_type->level != 1) {
614                                 rs->ti->error = "max_write_behind option is only valid for RAID1";
615                                 return -EINVAL;
616                         }
617                         rs->print_flags |= DMPF_MAX_WRITE_BEHIND;
618
619                         /*
620                          * In device-mapper, we specify things in sectors, but
621                          * MD records this value in kB
622                          */
623                         value /= 2;
624                         if (value > COUNTER_MAX) {
625                                 rs->ti->error = "Max write-behind limit out of range";
626                                 return -EINVAL;
627                         }
628                         rs->md.bitmap_info.max_write_behind = value;
629                 } else if (!strcasecmp(key, "daemon_sleep")) {
630                         rs->print_flags |= DMPF_DAEMON_SLEEP;
631                         if (!value || (value > MAX_SCHEDULE_TIMEOUT)) {
632                                 rs->ti->error = "daemon sleep period out of range";
633                                 return -EINVAL;
634                         }
635                         rs->md.bitmap_info.daemon_sleep = value;
636                 } else if (!strcasecmp(key, "stripe_cache")) {
637                         rs->print_flags |= DMPF_STRIPE_CACHE;
638
639                         /*
640                          * In device-mapper, we specify things in sectors, but
641                          * MD records this value in kB
642                          */
643                         value /= 2;
644
645                         if ((rs->raid_type->level != 5) &&
646                             (rs->raid_type->level != 6)) {
647                                 rs->ti->error = "Inappropriate argument: stripe_cache";
648                                 return -EINVAL;
649                         }
650                         if (raid5_set_cache_size(&rs->md, (int)value)) {
651                                 rs->ti->error = "Bad stripe_cache size";
652                                 return -EINVAL;
653                         }
654                 } else if (!strcasecmp(key, "min_recovery_rate")) {
655                         rs->print_flags |= DMPF_MIN_RECOVERY_RATE;
656                         if (value > INT_MAX) {
657                                 rs->ti->error = "min_recovery_rate out of range";
658                                 return -EINVAL;
659                         }
660                         rs->md.sync_speed_min = (int)value;
661                 } else if (!strcasecmp(key, "max_recovery_rate")) {
662                         rs->print_flags |= DMPF_MAX_RECOVERY_RATE;
663                         if (value > INT_MAX) {
664                                 rs->ti->error = "max_recovery_rate out of range";
665                                 return -EINVAL;
666                         }
667                         rs->md.sync_speed_max = (int)value;
668                 } else if (!strcasecmp(key, "region_size")) {
669                         rs->print_flags |= DMPF_REGION_SIZE;
670                         region_size = value;
671                 } else if (!strcasecmp(key, "raid10_copies") &&
672                            (rs->raid_type->level == 10)) {
673                         if ((value < 2) || (value > 0xFF)) {
674                                 rs->ti->error = "Bad value for 'raid10_copies'";
675                                 return -EINVAL;
676                         }
677                         rs->print_flags |= DMPF_RAID10_COPIES;
678                         raid10_copies = value;
679                 } else {
680                         DMERR("Unable to parse RAID parameter: %s", key);
681                         rs->ti->error = "Unable to parse RAID parameters";
682                         return -EINVAL;
683                 }
684         }
685
686         if (validate_region_size(rs, region_size))
687                 return -EINVAL;
688
689         if (rs->md.chunk_sectors)
690                 max_io_len = rs->md.chunk_sectors;
691         else
692                 max_io_len = region_size;
693
694         if (dm_set_target_max_io_len(rs->ti, max_io_len))
695                 return -EINVAL;
696
697         if (rs->raid_type->level == 10) {
698                 if (raid10_copies > rs->md.raid_disks) {
699                         rs->ti->error = "Not enough devices to satisfy specification";
700                         return -EINVAL;
701                 }
702
703                 /*
704                  * If the format is not "near", we only support
705                  * two copies at the moment.
706                  */
707                 if (strcmp("near", raid10_format) && (raid10_copies > 2)) {
708                         rs->ti->error = "Too many copies for given RAID10 format.";
709                         return -EINVAL;
710                 }
711
712                 /* (Len * #mirrors) / #devices */
713                 sectors_per_dev = rs->ti->len * raid10_copies;
714                 sector_div(sectors_per_dev, rs->md.raid_disks);
715
716                 rs->md.layout = raid10_format_to_md_layout(raid10_format,
717                                                            raid10_copies);
718                 rs->md.new_layout = rs->md.layout;
719         } else if ((rs->raid_type->level > 1) &&
720                    sector_div(sectors_per_dev,
721                               (rs->md.raid_disks - rs->raid_type->parity_devs))) {
722                 rs->ti->error = "Target length not divisible by number of data devices";
723                 return -EINVAL;
724         }
725         rs->md.dev_sectors = sectors_per_dev;
726
727         /* Assume there are no metadata devices until the drives are parsed */
728         rs->md.persistent = 0;
729         rs->md.external = 1;
730
731         return 0;
732 }
733
734 static void do_table_event(struct work_struct *ws)
735 {
736         struct raid_set *rs = container_of(ws, struct raid_set, md.event_work);
737
738         dm_table_event(rs->ti->table);
739 }
740
741 static int raid_is_congested(struct dm_target_callbacks *cb, int bits)
742 {
743         struct raid_set *rs = container_of(cb, struct raid_set, callbacks);
744
745         if (rs->raid_type->level == 1)
746                 return md_raid1_congested(&rs->md, bits);
747
748         if (rs->raid_type->level == 10)
749                 return md_raid10_congested(&rs->md, bits);
750
751         return md_raid5_congested(&rs->md, bits);
752 }
753
754 /*
755  * This structure is never routinely used by userspace, unlike md superblocks.
756  * Devices with this superblock should only ever be accessed via device-mapper.
757  */
758 #define DM_RAID_MAGIC 0x64526D44
759 struct dm_raid_superblock {
760         __le32 magic;           /* "DmRd" */
761         __le32 features;        /* Used to indicate possible future changes */
762
763         __le32 num_devices;     /* Number of devices in this array. (Max 64) */
764         __le32 array_position;  /* The position of this drive in the array */
765
766         __le64 events;          /* Incremented by md when superblock updated */
767         __le64 failed_devices;  /* Bit field of devices to indicate failures */
768
769         /*
770          * This offset tracks the progress of the repair or replacement of
771          * an individual drive.
772          */
773         __le64 disk_recovery_offset;
774
775         /*
776          * This offset tracks the progress of the initial array
777          * synchronisation/parity calculation.
778          */
779         __le64 array_resync_offset;
780
781         /*
782          * RAID characteristics
783          */
784         __le32 level;
785         __le32 layout;
786         __le32 stripe_sectors;
787
788         __u8 pad[452];          /* Round struct to 512 bytes. */
789                                 /* Always set to 0 when writing. */
790 } __packed;
791
792 static int read_disk_sb(struct md_rdev *rdev, int size)
793 {
794         BUG_ON(!rdev->sb_page);
795
796         if (rdev->sb_loaded)
797                 return 0;
798
799         if (!sync_page_io(rdev, 0, size, rdev->sb_page, READ, 1)) {
800                 DMERR("Failed to read superblock of device at position %d",
801                       rdev->raid_disk);
802                 md_error(rdev->mddev, rdev);
803                 return -EINVAL;
804         }
805
806         rdev->sb_loaded = 1;
807
808         return 0;
809 }
810
811 static void super_sync(struct mddev *mddev, struct md_rdev *rdev)
812 {
813         int i;
814         uint64_t failed_devices;
815         struct dm_raid_superblock *sb;
816         struct raid_set *rs = container_of(mddev, struct raid_set, md);
817
818         sb = page_address(rdev->sb_page);
819         failed_devices = le64_to_cpu(sb->failed_devices);
820
821         for (i = 0; i < mddev->raid_disks; i++)
822                 if (!rs->dev[i].data_dev ||
823                     test_bit(Faulty, &(rs->dev[i].rdev.flags)))
824                         failed_devices |= (1ULL << i);
825
826         memset(sb, 0, sizeof(*sb));
827
828         sb->magic = cpu_to_le32(DM_RAID_MAGIC);
829         sb->features = cpu_to_le32(0);  /* No features yet */
830
831         sb->num_devices = cpu_to_le32(mddev->raid_disks);
832         sb->array_position = cpu_to_le32(rdev->raid_disk);
833
834         sb->events = cpu_to_le64(mddev->events);
835         sb->failed_devices = cpu_to_le64(failed_devices);
836
837         sb->disk_recovery_offset = cpu_to_le64(rdev->recovery_offset);
838         sb->array_resync_offset = cpu_to_le64(mddev->recovery_cp);
839
840         sb->level = cpu_to_le32(mddev->level);
841         sb->layout = cpu_to_le32(mddev->layout);
842         sb->stripe_sectors = cpu_to_le32(mddev->chunk_sectors);
843 }
844
845 /*
846  * super_load
847  *
848  * This function creates a superblock if one is not found on the device
849  * and will decide which superblock to use if there's a choice.
850  *
851  * Return: 1 if use rdev, 0 if use refdev, -Exxx otherwise
852  */
853 static int super_load(struct md_rdev *rdev, struct md_rdev *refdev)
854 {
855         int ret;
856         struct dm_raid_superblock *sb;
857         struct dm_raid_superblock *refsb;
858         uint64_t events_sb, events_refsb;
859
860         rdev->sb_start = 0;
861         rdev->sb_size = sizeof(*sb);
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
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
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  */
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  * Construct a RAID4/5/6 mapping:
1154  * Args:
1155  *      <raid_type> <#raid_params> <raid_params>                \
1156  *      <#raid_devs> { <meta_dev1> <dev1> .. <meta_devN> <devN> }
1157  *
1158  * <raid_params> varies by <raid_type>.  See 'parse_raid_params' for
1159  * details on possible <raid_params>.
1160  */
1161 static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv)
1162 {
1163         int ret;
1164         struct raid_type *rt;
1165         unsigned long num_raid_params, num_raid_devs;
1166         struct raid_set *rs = NULL;
1167
1168         /* Must have at least <raid_type> <#raid_params> */
1169         if (argc < 2) {
1170                 ti->error = "Too few arguments";
1171                 return -EINVAL;
1172         }
1173
1174         /* raid type */
1175         rt = get_raid_type(argv[0]);
1176         if (!rt) {
1177                 ti->error = "Unrecognised raid_type";
1178                 return -EINVAL;
1179         }
1180         argc--;
1181         argv++;
1182
1183         /* number of RAID parameters */
1184         if (strict_strtoul(argv[0], 10, &num_raid_params) < 0) {
1185                 ti->error = "Cannot understand number of RAID parameters";
1186                 return -EINVAL;
1187         }
1188         argc--;
1189         argv++;
1190
1191         /* Skip over RAID params for now and find out # of devices */
1192         if (num_raid_params + 1 > argc) {
1193                 ti->error = "Arguments do not agree with counts given";
1194                 return -EINVAL;
1195         }
1196
1197         if ((strict_strtoul(argv[num_raid_params], 10, &num_raid_devs) < 0) ||
1198             (num_raid_devs >= INT_MAX)) {
1199                 ti->error = "Cannot understand number of raid devices";
1200                 return -EINVAL;
1201         }
1202
1203         rs = context_alloc(ti, rt, (unsigned)num_raid_devs);
1204         if (IS_ERR(rs))
1205                 return PTR_ERR(rs);
1206
1207         ret = parse_raid_params(rs, argv, (unsigned)num_raid_params);
1208         if (ret)
1209                 goto bad;
1210
1211         ret = -EINVAL;
1212
1213         argc -= num_raid_params + 1; /* +1: we already have num_raid_devs */
1214         argv += num_raid_params + 1;
1215
1216         if (argc != (num_raid_devs * 2)) {
1217                 ti->error = "Supplied RAID devices does not match the count given";
1218                 goto bad;
1219         }
1220
1221         ret = dev_parms(rs, argv);
1222         if (ret)
1223                 goto bad;
1224
1225         rs->md.sync_super = super_sync;
1226         ret = analyse_superblocks(ti, rs);
1227         if (ret)
1228                 goto bad;
1229
1230         INIT_WORK(&rs->md.event_work, do_table_event);
1231         ti->private = rs;
1232         ti->num_flush_bios = 1;
1233
1234         mutex_lock(&rs->md.reconfig_mutex);
1235         ret = md_run(&rs->md);
1236         rs->md.in_sync = 0; /* Assume already marked dirty */
1237         mutex_unlock(&rs->md.reconfig_mutex);
1238
1239         if (ret) {
1240                 ti->error = "Fail to run raid array";
1241                 goto bad;
1242         }
1243
1244         if (ti->len != rs->md.array_sectors) {
1245                 ti->error = "Array size does not match requested target length";
1246                 ret = -EINVAL;
1247                 goto size_mismatch;
1248         }
1249         rs->callbacks.congested_fn = raid_is_congested;
1250         dm_table_add_target_callbacks(ti->table, &rs->callbacks);
1251
1252         mddev_suspend(&rs->md);
1253         return 0;
1254
1255 size_mismatch:
1256         md_stop(&rs->md);
1257 bad:
1258         context_free(rs);
1259
1260         return ret;
1261 }
1262
1263 static void raid_dtr(struct dm_target *ti)
1264 {
1265         struct raid_set *rs = ti->private;
1266
1267         list_del_init(&rs->callbacks.list);
1268         md_stop(&rs->md);
1269         context_free(rs);
1270 }
1271
1272 static int raid_map(struct dm_target *ti, struct bio *bio)
1273 {
1274         struct raid_set *rs = ti->private;
1275         struct mddev *mddev = &rs->md;
1276
1277         mddev->pers->make_request(mddev, bio);
1278
1279         return DM_MAPIO_SUBMITTED;
1280 }
1281
1282 static void raid_status(struct dm_target *ti, status_type_t type,
1283                         unsigned status_flags, char *result, unsigned maxlen)
1284 {
1285         struct raid_set *rs = ti->private;
1286         unsigned raid_param_cnt = 1; /* at least 1 for chunksize */
1287         unsigned sz = 0;
1288         int i, array_in_sync = 0;
1289         sector_t sync;
1290
1291         switch (type) {
1292         case STATUSTYPE_INFO:
1293                 DMEMIT("%s %d ", rs->raid_type->name, rs->md.raid_disks);
1294
1295                 if (test_bit(MD_RECOVERY_RUNNING, &rs->md.recovery))
1296                         sync = rs->md.curr_resync_completed;
1297                 else
1298                         sync = rs->md.recovery_cp;
1299
1300                 if (sync >= rs->md.resync_max_sectors) {
1301                         array_in_sync = 1;
1302                         sync = rs->md.resync_max_sectors;
1303                 } else {
1304                         /*
1305                          * The array may be doing an initial sync, or it may
1306                          * be rebuilding individual components.  If all the
1307                          * devices are In_sync, then it is the array that is
1308                          * being initialized.
1309                          */
1310                         for (i = 0; i < rs->md.raid_disks; i++)
1311                                 if (!test_bit(In_sync, &rs->dev[i].rdev.flags))
1312                                         array_in_sync = 1;
1313                 }
1314                 /*
1315                  * Status characters:
1316                  *  'D' = Dead/Failed device
1317                  *  'a' = Alive but not in-sync
1318                  *  'A' = Alive and in-sync
1319                  */
1320                 for (i = 0; i < rs->md.raid_disks; i++) {
1321                         if (test_bit(Faulty, &rs->dev[i].rdev.flags))
1322                                 DMEMIT("D");
1323                         else if (!array_in_sync ||
1324                                  !test_bit(In_sync, &rs->dev[i].rdev.flags))
1325                                 DMEMIT("a");
1326                         else
1327                                 DMEMIT("A");
1328                 }
1329
1330                 /*
1331                  * In-sync ratio:
1332                  *  The in-sync ratio shows the progress of:
1333                  *   - Initializing the array
1334                  *   - Rebuilding a subset of devices of the array
1335                  *  The user can distinguish between the two by referring
1336                  *  to the status characters.
1337                  */
1338                 DMEMIT(" %llu/%llu",
1339                        (unsigned long long) sync,
1340                        (unsigned long long) rs->md.resync_max_sectors);
1341
1342                 break;
1343         case STATUSTYPE_TABLE:
1344                 /* The string you would use to construct this array */
1345                 for (i = 0; i < rs->md.raid_disks; i++) {
1346                         if ((rs->print_flags & DMPF_REBUILD) &&
1347                             rs->dev[i].data_dev &&
1348                             !test_bit(In_sync, &rs->dev[i].rdev.flags))
1349                                 raid_param_cnt += 2; /* for rebuilds */
1350                         if (rs->dev[i].data_dev &&
1351                             test_bit(WriteMostly, &rs->dev[i].rdev.flags))
1352                                 raid_param_cnt += 2;
1353                 }
1354
1355                 raid_param_cnt += (hweight32(rs->print_flags & ~DMPF_REBUILD) * 2);
1356                 if (rs->print_flags & (DMPF_SYNC | DMPF_NOSYNC))
1357                         raid_param_cnt--;
1358
1359                 DMEMIT("%s %u %u", rs->raid_type->name,
1360                        raid_param_cnt, rs->md.chunk_sectors);
1361
1362                 if ((rs->print_flags & DMPF_SYNC) &&
1363                     (rs->md.recovery_cp == MaxSector))
1364                         DMEMIT(" sync");
1365                 if (rs->print_flags & DMPF_NOSYNC)
1366                         DMEMIT(" nosync");
1367
1368                 for (i = 0; i < rs->md.raid_disks; i++)
1369                         if ((rs->print_flags & DMPF_REBUILD) &&
1370                             rs->dev[i].data_dev &&
1371                             !test_bit(In_sync, &rs->dev[i].rdev.flags))
1372                                 DMEMIT(" rebuild %u", i);
1373
1374                 if (rs->print_flags & DMPF_DAEMON_SLEEP)
1375                         DMEMIT(" daemon_sleep %lu",
1376                                rs->md.bitmap_info.daemon_sleep);
1377
1378                 if (rs->print_flags & DMPF_MIN_RECOVERY_RATE)
1379                         DMEMIT(" min_recovery_rate %d", rs->md.sync_speed_min);
1380
1381                 if (rs->print_flags & DMPF_MAX_RECOVERY_RATE)
1382                         DMEMIT(" max_recovery_rate %d", rs->md.sync_speed_max);
1383
1384                 for (i = 0; i < rs->md.raid_disks; i++)
1385                         if (rs->dev[i].data_dev &&
1386                             test_bit(WriteMostly, &rs->dev[i].rdev.flags))
1387                                 DMEMIT(" write_mostly %u", i);
1388
1389                 if (rs->print_flags & DMPF_MAX_WRITE_BEHIND)
1390                         DMEMIT(" max_write_behind %lu",
1391                                rs->md.bitmap_info.max_write_behind);
1392
1393                 if (rs->print_flags & DMPF_STRIPE_CACHE) {
1394                         struct r5conf *conf = rs->md.private;
1395
1396                         /* convert from kiB to sectors */
1397                         DMEMIT(" stripe_cache %d",
1398                                conf ? conf->max_nr_stripes * 2 : 0);
1399                 }
1400
1401                 if (rs->print_flags & DMPF_REGION_SIZE)
1402                         DMEMIT(" region_size %lu",
1403                                rs->md.bitmap_info.chunksize >> 9);
1404
1405                 if (rs->print_flags & DMPF_RAID10_COPIES)
1406                         DMEMIT(" raid10_copies %u",
1407                                raid10_md_layout_to_copies(rs->md.layout));
1408
1409                 if (rs->print_flags & DMPF_RAID10_FORMAT)
1410                         DMEMIT(" raid10_format %s",
1411                                raid10_md_layout_to_format(rs->md.layout));
1412
1413                 DMEMIT(" %d", rs->md.raid_disks);
1414                 for (i = 0; i < rs->md.raid_disks; i++) {
1415                         if (rs->dev[i].meta_dev)
1416                                 DMEMIT(" %s", rs->dev[i].meta_dev->name);
1417                         else
1418                                 DMEMIT(" -");
1419
1420                         if (rs->dev[i].data_dev)
1421                                 DMEMIT(" %s", rs->dev[i].data_dev->name);
1422                         else
1423                                 DMEMIT(" -");
1424                 }
1425         }
1426 }
1427
1428 static int raid_iterate_devices(struct dm_target *ti, iterate_devices_callout_fn fn, void *data)
1429 {
1430         struct raid_set *rs = ti->private;
1431         unsigned i;
1432         int ret = 0;
1433
1434         for (i = 0; !ret && i < rs->md.raid_disks; i++)
1435                 if (rs->dev[i].data_dev)
1436                         ret = fn(ti,
1437                                  rs->dev[i].data_dev,
1438                                  0, /* No offset on data devs */
1439                                  rs->md.dev_sectors,
1440                                  data);
1441
1442         return ret;
1443 }
1444
1445 static void raid_io_hints(struct dm_target *ti, struct queue_limits *limits)
1446 {
1447         struct raid_set *rs = ti->private;
1448         unsigned chunk_size = rs->md.chunk_sectors << 9;
1449         struct r5conf *conf = rs->md.private;
1450
1451         blk_limits_io_min(limits, chunk_size);
1452         blk_limits_io_opt(limits, chunk_size * (conf->raid_disks - conf->max_degraded));
1453 }
1454
1455 static void raid_presuspend(struct dm_target *ti)
1456 {
1457         struct raid_set *rs = ti->private;
1458
1459         md_stop_writes(&rs->md);
1460 }
1461
1462 static void raid_postsuspend(struct dm_target *ti)
1463 {
1464         struct raid_set *rs = ti->private;
1465
1466         mddev_suspend(&rs->md);
1467 }
1468
1469 static void raid_resume(struct dm_target *ti)
1470 {
1471         struct raid_set *rs = ti->private;
1472
1473         set_bit(MD_CHANGE_DEVS, &rs->md.flags);
1474         if (!rs->bitmap_loaded) {
1475                 bitmap_load(&rs->md);
1476                 rs->bitmap_loaded = 1;
1477         }
1478
1479         clear_bit(MD_RECOVERY_FROZEN, &rs->md.recovery);
1480         mddev_resume(&rs->md);
1481 }
1482
1483 static struct target_type raid_target = {
1484         .name = "raid",
1485         .version = {1, 4, 2},
1486         .module = THIS_MODULE,
1487         .ctr = raid_ctr,
1488         .dtr = raid_dtr,
1489         .map = raid_map,
1490         .status = raid_status,
1491         .iterate_devices = raid_iterate_devices,
1492         .io_hints = raid_io_hints,
1493         .presuspend = raid_presuspend,
1494         .postsuspend = raid_postsuspend,
1495         .resume = raid_resume,
1496 };
1497
1498 static int __init dm_raid_init(void)
1499 {
1500         DMINFO("Loading target version %u.%u.%u",
1501                raid_target.version[0],
1502                raid_target.version[1],
1503                raid_target.version[2]);
1504         return dm_register_target(&raid_target);
1505 }
1506
1507 static void __exit dm_raid_exit(void)
1508 {
1509         dm_unregister_target(&raid_target);
1510 }
1511
1512 module_init(dm_raid_init);
1513 module_exit(dm_raid_exit);
1514
1515 MODULE_DESCRIPTION(DM_NAME " raid4/5/6 target");
1516 MODULE_ALIAS("dm-raid1");
1517 MODULE_ALIAS("dm-raid10");
1518 MODULE_ALIAS("dm-raid4");
1519 MODULE_ALIAS("dm-raid5");
1520 MODULE_ALIAS("dm-raid6");
1521 MODULE_AUTHOR("Neil Brown <dm-devel@redhat.com>");
1522 MODULE_LICENSE("GPL");