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1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2003 Sistina Software Limited. | |
3 | * | |
4 | * This file is released under the GPL. | |
5 | */ | |
6 | ||
7 | #include "dm.h" | |
8 | #include "dm-bio-list.h" | |
9 | #include "dm-io.h" | |
10 | #include "dm-log.h" | |
11 | #include "kcopyd.h" | |
12 | ||
13 | #include <linux/ctype.h> | |
14 | #include <linux/init.h> | |
15 | #include <linux/mempool.h> | |
16 | #include <linux/module.h> | |
17 | #include <linux/pagemap.h> | |
18 | #include <linux/slab.h> | |
19 | #include <linux/time.h> | |
20 | #include <linux/vmalloc.h> | |
21 | #include <linux/workqueue.h> | |
22 | ||
72d94861 AK |
23 | #define DM_MSG_PREFIX "raid1" |
24 | ||
1da177e4 LT |
25 | static struct workqueue_struct *_kmirrord_wq; |
26 | static struct work_struct _kmirrord_work; | |
33184048 | 27 | static DECLARE_WAIT_QUEUE_HEAD(_kmirrord_recovery_stopped); |
1da177e4 LT |
28 | |
29 | static inline void wake(void) | |
30 | { | |
31 | queue_work(_kmirrord_wq, &_kmirrord_work); | |
32 | } | |
33 | ||
34 | /*----------------------------------------------------------------- | |
35 | * Region hash | |
36 | * | |
37 | * The mirror splits itself up into discrete regions. Each | |
38 | * region can be in one of three states: clean, dirty, | |
39 | * nosync. There is no need to put clean regions in the hash. | |
40 | * | |
41 | * In addition to being present in the hash table a region _may_ | |
42 | * be present on one of three lists. | |
43 | * | |
44 | * clean_regions: Regions on this list have no io pending to | |
45 | * them, they are in sync, we are no longer interested in them, | |
46 | * they are dull. rh_update_states() will remove them from the | |
47 | * hash table. | |
48 | * | |
49 | * quiesced_regions: These regions have been spun down, ready | |
50 | * for recovery. rh_recovery_start() will remove regions from | |
51 | * this list and hand them to kmirrord, which will schedule the | |
52 | * recovery io with kcopyd. | |
53 | * | |
54 | * recovered_regions: Regions that kcopyd has successfully | |
55 | * recovered. rh_update_states() will now schedule any delayed | |
56 | * io, up the recovery_count, and remove the region from the | |
57 | * hash. | |
58 | * | |
59 | * There are 2 locks: | |
60 | * A rw spin lock 'hash_lock' protects just the hash table, | |
61 | * this is never held in write mode from interrupt context, | |
62 | * which I believe means that we only have to disable irqs when | |
63 | * doing a write lock. | |
64 | * | |
65 | * An ordinary spin lock 'region_lock' that protects the three | |
66 | * lists in the region_hash, with the 'state', 'list' and | |
67 | * 'bhs_delayed' fields of the regions. This is used from irq | |
68 | * context, so all other uses will have to suspend local irqs. | |
69 | *---------------------------------------------------------------*/ | |
70 | struct mirror_set; | |
71 | struct region_hash { | |
72 | struct mirror_set *ms; | |
73 | uint32_t region_size; | |
74 | unsigned region_shift; | |
75 | ||
76 | /* holds persistent region state */ | |
77 | struct dirty_log *log; | |
78 | ||
79 | /* hash table */ | |
80 | rwlock_t hash_lock; | |
81 | mempool_t *region_pool; | |
82 | unsigned int mask; | |
83 | unsigned int nr_buckets; | |
84 | struct list_head *buckets; | |
85 | ||
86 | spinlock_t region_lock; | |
33184048 | 87 | atomic_t recovery_in_flight; |
1da177e4 LT |
88 | struct semaphore recovery_count; |
89 | struct list_head clean_regions; | |
90 | struct list_head quiesced_regions; | |
91 | struct list_head recovered_regions; | |
92 | }; | |
93 | ||
94 | enum { | |
95 | RH_CLEAN, | |
96 | RH_DIRTY, | |
97 | RH_NOSYNC, | |
98 | RH_RECOVERING | |
99 | }; | |
100 | ||
101 | struct region { | |
102 | struct region_hash *rh; /* FIXME: can we get rid of this ? */ | |
103 | region_t key; | |
104 | int state; | |
105 | ||
106 | struct list_head hash_list; | |
107 | struct list_head list; | |
108 | ||
109 | atomic_t pending; | |
110 | struct bio_list delayed_bios; | |
111 | }; | |
112 | ||
e4c8b3ba NB |
113 | |
114 | /*----------------------------------------------------------------- | |
115 | * Mirror set structures. | |
116 | *---------------------------------------------------------------*/ | |
117 | struct mirror { | |
118 | atomic_t error_count; | |
119 | struct dm_dev *dev; | |
120 | sector_t offset; | |
121 | }; | |
122 | ||
123 | struct mirror_set { | |
124 | struct dm_target *ti; | |
125 | struct list_head list; | |
126 | struct region_hash rh; | |
127 | struct kcopyd_client *kcopyd_client; | |
128 | ||
129 | spinlock_t lock; /* protects the next two lists */ | |
130 | struct bio_list reads; | |
131 | struct bio_list writes; | |
132 | ||
133 | /* recovery */ | |
134 | region_t nr_regions; | |
135 | int in_sync; | |
136 | ||
137 | struct mirror *default_mirror; /* Default mirror */ | |
138 | ||
139 | unsigned int nr_mirrors; | |
140 | struct mirror mirror[0]; | |
141 | }; | |
142 | ||
1da177e4 LT |
143 | /* |
144 | * Conversion fns | |
145 | */ | |
146 | static inline region_t bio_to_region(struct region_hash *rh, struct bio *bio) | |
147 | { | |
e4c8b3ba | 148 | return (bio->bi_sector - rh->ms->ti->begin) >> rh->region_shift; |
1da177e4 LT |
149 | } |
150 | ||
151 | static inline sector_t region_to_sector(struct region_hash *rh, region_t region) | |
152 | { | |
153 | return region << rh->region_shift; | |
154 | } | |
155 | ||
156 | /* FIXME move this */ | |
157 | static void queue_bio(struct mirror_set *ms, struct bio *bio, int rw); | |
158 | ||
1da177e4 LT |
159 | #define MIN_REGIONS 64 |
160 | #define MAX_RECOVERY 1 | |
161 | static int rh_init(struct region_hash *rh, struct mirror_set *ms, | |
162 | struct dirty_log *log, uint32_t region_size, | |
163 | region_t nr_regions) | |
164 | { | |
165 | unsigned int nr_buckets, max_buckets; | |
166 | size_t i; | |
167 | ||
168 | /* | |
169 | * Calculate a suitable number of buckets for our hash | |
170 | * table. | |
171 | */ | |
172 | max_buckets = nr_regions >> 6; | |
173 | for (nr_buckets = 128u; nr_buckets < max_buckets; nr_buckets <<= 1) | |
174 | ; | |
175 | nr_buckets >>= 1; | |
176 | ||
177 | rh->ms = ms; | |
178 | rh->log = log; | |
179 | rh->region_size = region_size; | |
180 | rh->region_shift = ffs(region_size) - 1; | |
181 | rwlock_init(&rh->hash_lock); | |
182 | rh->mask = nr_buckets - 1; | |
183 | rh->nr_buckets = nr_buckets; | |
184 | ||
185 | rh->buckets = vmalloc(nr_buckets * sizeof(*rh->buckets)); | |
186 | if (!rh->buckets) { | |
187 | DMERR("unable to allocate region hash memory"); | |
188 | return -ENOMEM; | |
189 | } | |
190 | ||
191 | for (i = 0; i < nr_buckets; i++) | |
192 | INIT_LIST_HEAD(rh->buckets + i); | |
193 | ||
194 | spin_lock_init(&rh->region_lock); | |
195 | sema_init(&rh->recovery_count, 0); | |
33184048 | 196 | atomic_set(&rh->recovery_in_flight, 0); |
1da177e4 LT |
197 | INIT_LIST_HEAD(&rh->clean_regions); |
198 | INIT_LIST_HEAD(&rh->quiesced_regions); | |
199 | INIT_LIST_HEAD(&rh->recovered_regions); | |
200 | ||
0eaae62a MD |
201 | rh->region_pool = mempool_create_kmalloc_pool(MIN_REGIONS, |
202 | sizeof(struct region)); | |
1da177e4 LT |
203 | if (!rh->region_pool) { |
204 | vfree(rh->buckets); | |
205 | rh->buckets = NULL; | |
206 | return -ENOMEM; | |
207 | } | |
208 | ||
209 | return 0; | |
210 | } | |
211 | ||
212 | static void rh_exit(struct region_hash *rh) | |
213 | { | |
214 | unsigned int h; | |
215 | struct region *reg, *nreg; | |
216 | ||
217 | BUG_ON(!list_empty(&rh->quiesced_regions)); | |
218 | for (h = 0; h < rh->nr_buckets; h++) { | |
219 | list_for_each_entry_safe(reg, nreg, rh->buckets + h, hash_list) { | |
220 | BUG_ON(atomic_read(®->pending)); | |
221 | mempool_free(reg, rh->region_pool); | |
222 | } | |
223 | } | |
224 | ||
225 | if (rh->log) | |
226 | dm_destroy_dirty_log(rh->log); | |
227 | if (rh->region_pool) | |
228 | mempool_destroy(rh->region_pool); | |
229 | vfree(rh->buckets); | |
230 | } | |
231 | ||
232 | #define RH_HASH_MULT 2654435387U | |
233 | ||
234 | static inline unsigned int rh_hash(struct region_hash *rh, region_t region) | |
235 | { | |
236 | return (unsigned int) ((region * RH_HASH_MULT) >> 12) & rh->mask; | |
237 | } | |
238 | ||
239 | static struct region *__rh_lookup(struct region_hash *rh, region_t region) | |
240 | { | |
241 | struct region *reg; | |
242 | ||
243 | list_for_each_entry (reg, rh->buckets + rh_hash(rh, region), hash_list) | |
244 | if (reg->key == region) | |
245 | return reg; | |
246 | ||
247 | return NULL; | |
248 | } | |
249 | ||
250 | static void __rh_insert(struct region_hash *rh, struct region *reg) | |
251 | { | |
252 | unsigned int h = rh_hash(rh, reg->key); | |
253 | list_add(®->hash_list, rh->buckets + h); | |
254 | } | |
255 | ||
256 | static struct region *__rh_alloc(struct region_hash *rh, region_t region) | |
257 | { | |
258 | struct region *reg, *nreg; | |
259 | ||
260 | read_unlock(&rh->hash_lock); | |
c06aad85 DK |
261 | nreg = mempool_alloc(rh->region_pool, GFP_ATOMIC); |
262 | if (unlikely(!nreg)) | |
263 | nreg = kmalloc(sizeof(struct region), GFP_NOIO); | |
1da177e4 LT |
264 | nreg->state = rh->log->type->in_sync(rh->log, region, 1) ? |
265 | RH_CLEAN : RH_NOSYNC; | |
266 | nreg->rh = rh; | |
267 | nreg->key = region; | |
268 | ||
269 | INIT_LIST_HEAD(&nreg->list); | |
270 | ||
271 | atomic_set(&nreg->pending, 0); | |
272 | bio_list_init(&nreg->delayed_bios); | |
273 | write_lock_irq(&rh->hash_lock); | |
274 | ||
275 | reg = __rh_lookup(rh, region); | |
276 | if (reg) | |
277 | /* we lost the race */ | |
278 | mempool_free(nreg, rh->region_pool); | |
279 | ||
280 | else { | |
281 | __rh_insert(rh, nreg); | |
282 | if (nreg->state == RH_CLEAN) { | |
283 | spin_lock(&rh->region_lock); | |
284 | list_add(&nreg->list, &rh->clean_regions); | |
285 | spin_unlock(&rh->region_lock); | |
286 | } | |
287 | reg = nreg; | |
288 | } | |
289 | write_unlock_irq(&rh->hash_lock); | |
290 | read_lock(&rh->hash_lock); | |
291 | ||
292 | return reg; | |
293 | } | |
294 | ||
295 | static inline struct region *__rh_find(struct region_hash *rh, region_t region) | |
296 | { | |
297 | struct region *reg; | |
298 | ||
299 | reg = __rh_lookup(rh, region); | |
300 | if (!reg) | |
301 | reg = __rh_alloc(rh, region); | |
302 | ||
303 | return reg; | |
304 | } | |
305 | ||
306 | static int rh_state(struct region_hash *rh, region_t region, int may_block) | |
307 | { | |
308 | int r; | |
309 | struct region *reg; | |
310 | ||
311 | read_lock(&rh->hash_lock); | |
312 | reg = __rh_lookup(rh, region); | |
313 | read_unlock(&rh->hash_lock); | |
314 | ||
315 | if (reg) | |
316 | return reg->state; | |
317 | ||
318 | /* | |
319 | * The region wasn't in the hash, so we fall back to the | |
320 | * dirty log. | |
321 | */ | |
322 | r = rh->log->type->in_sync(rh->log, region, may_block); | |
323 | ||
324 | /* | |
325 | * Any error from the dirty log (eg. -EWOULDBLOCK) gets | |
326 | * taken as a RH_NOSYNC | |
327 | */ | |
328 | return r == 1 ? RH_CLEAN : RH_NOSYNC; | |
329 | } | |
330 | ||
331 | static inline int rh_in_sync(struct region_hash *rh, | |
332 | region_t region, int may_block) | |
333 | { | |
334 | int state = rh_state(rh, region, may_block); | |
335 | return state == RH_CLEAN || state == RH_DIRTY; | |
336 | } | |
337 | ||
338 | static void dispatch_bios(struct mirror_set *ms, struct bio_list *bio_list) | |
339 | { | |
340 | struct bio *bio; | |
341 | ||
342 | while ((bio = bio_list_pop(bio_list))) { | |
343 | queue_bio(ms, bio, WRITE); | |
344 | } | |
345 | } | |
346 | ||
347 | static void rh_update_states(struct region_hash *rh) | |
348 | { | |
349 | struct region *reg, *next; | |
350 | ||
351 | LIST_HEAD(clean); | |
352 | LIST_HEAD(recovered); | |
353 | ||
354 | /* | |
355 | * Quickly grab the lists. | |
356 | */ | |
357 | write_lock_irq(&rh->hash_lock); | |
358 | spin_lock(&rh->region_lock); | |
359 | if (!list_empty(&rh->clean_regions)) { | |
360 | list_splice(&rh->clean_regions, &clean); | |
361 | INIT_LIST_HEAD(&rh->clean_regions); | |
362 | ||
363 | list_for_each_entry (reg, &clean, list) { | |
364 | rh->log->type->clear_region(rh->log, reg->key); | |
365 | list_del(®->hash_list); | |
366 | } | |
367 | } | |
368 | ||
369 | if (!list_empty(&rh->recovered_regions)) { | |
370 | list_splice(&rh->recovered_regions, &recovered); | |
371 | INIT_LIST_HEAD(&rh->recovered_regions); | |
372 | ||
373 | list_for_each_entry (reg, &recovered, list) | |
374 | list_del(®->hash_list); | |
375 | } | |
376 | spin_unlock(&rh->region_lock); | |
377 | write_unlock_irq(&rh->hash_lock); | |
378 | ||
379 | /* | |
380 | * All the regions on the recovered and clean lists have | |
381 | * now been pulled out of the system, so no need to do | |
382 | * any more locking. | |
383 | */ | |
384 | list_for_each_entry_safe (reg, next, &recovered, list) { | |
385 | rh->log->type->clear_region(rh->log, reg->key); | |
386 | rh->log->type->complete_resync_work(rh->log, reg->key, 1); | |
387 | dispatch_bios(rh->ms, ®->delayed_bios); | |
33184048 JB |
388 | if (atomic_dec_and_test(&rh->recovery_in_flight)) |
389 | wake_up_all(&_kmirrord_recovery_stopped); | |
1da177e4 LT |
390 | up(&rh->recovery_count); |
391 | mempool_free(reg, rh->region_pool); | |
392 | } | |
393 | ||
394 | if (!list_empty(&recovered)) | |
395 | rh->log->type->flush(rh->log); | |
396 | ||
397 | list_for_each_entry_safe (reg, next, &clean, list) | |
398 | mempool_free(reg, rh->region_pool); | |
399 | } | |
400 | ||
401 | static void rh_inc(struct region_hash *rh, region_t region) | |
402 | { | |
403 | struct region *reg; | |
404 | ||
405 | read_lock(&rh->hash_lock); | |
406 | reg = __rh_find(rh, region); | |
844e8d90 | 407 | |
7692c5dd | 408 | spin_lock_irq(&rh->region_lock); |
844e8d90 JN |
409 | atomic_inc(®->pending); |
410 | ||
1da177e4 | 411 | if (reg->state == RH_CLEAN) { |
1da177e4 LT |
412 | reg->state = RH_DIRTY; |
413 | list_del_init(®->list); /* take off the clean list */ | |
7692c5dd JB |
414 | spin_unlock_irq(&rh->region_lock); |
415 | ||
416 | rh->log->type->mark_region(rh->log, reg->key); | |
417 | } else | |
418 | spin_unlock_irq(&rh->region_lock); | |
419 | ||
1da177e4 | 420 | |
1da177e4 LT |
421 | read_unlock(&rh->hash_lock); |
422 | } | |
423 | ||
424 | static void rh_inc_pending(struct region_hash *rh, struct bio_list *bios) | |
425 | { | |
426 | struct bio *bio; | |
427 | ||
428 | for (bio = bios->head; bio; bio = bio->bi_next) | |
429 | rh_inc(rh, bio_to_region(rh, bio)); | |
430 | } | |
431 | ||
432 | static void rh_dec(struct region_hash *rh, region_t region) | |
433 | { | |
434 | unsigned long flags; | |
435 | struct region *reg; | |
436 | int should_wake = 0; | |
437 | ||
438 | read_lock(&rh->hash_lock); | |
439 | reg = __rh_lookup(rh, region); | |
440 | read_unlock(&rh->hash_lock); | |
441 | ||
7692c5dd | 442 | spin_lock_irqsave(&rh->region_lock, flags); |
1da177e4 | 443 | if (atomic_dec_and_test(®->pending)) { |
930d332a JN |
444 | /* |
445 | * There is no pending I/O for this region. | |
446 | * We can move the region to corresponding list for next action. | |
447 | * At this point, the region is not yet connected to any list. | |
448 | * | |
449 | * If the state is RH_NOSYNC, the region should be kept off | |
450 | * from clean list. | |
451 | * The hash entry for RH_NOSYNC will remain in memory | |
452 | * until the region is recovered or the map is reloaded. | |
453 | */ | |
454 | ||
455 | /* do nothing for RH_NOSYNC */ | |
1da177e4 LT |
456 | if (reg->state == RH_RECOVERING) { |
457 | list_add_tail(®->list, &rh->quiesced_regions); | |
930d332a | 458 | } else if (reg->state == RH_DIRTY) { |
1da177e4 LT |
459 | reg->state = RH_CLEAN; |
460 | list_add(®->list, &rh->clean_regions); | |
461 | } | |
1da177e4 LT |
462 | should_wake = 1; |
463 | } | |
7692c5dd | 464 | spin_unlock_irqrestore(&rh->region_lock, flags); |
1da177e4 LT |
465 | |
466 | if (should_wake) | |
467 | wake(); | |
468 | } | |
469 | ||
470 | /* | |
471 | * Starts quiescing a region in preparation for recovery. | |
472 | */ | |
473 | static int __rh_recovery_prepare(struct region_hash *rh) | |
474 | { | |
475 | int r; | |
476 | struct region *reg; | |
477 | region_t region; | |
478 | ||
479 | /* | |
480 | * Ask the dirty log what's next. | |
481 | */ | |
482 | r = rh->log->type->get_resync_work(rh->log, ®ion); | |
483 | if (r <= 0) | |
484 | return r; | |
485 | ||
486 | /* | |
487 | * Get this region, and start it quiescing by setting the | |
488 | * recovering flag. | |
489 | */ | |
490 | read_lock(&rh->hash_lock); | |
491 | reg = __rh_find(rh, region); | |
492 | read_unlock(&rh->hash_lock); | |
493 | ||
494 | spin_lock_irq(&rh->region_lock); | |
495 | reg->state = RH_RECOVERING; | |
496 | ||
497 | /* Already quiesced ? */ | |
498 | if (atomic_read(®->pending)) | |
499 | list_del_init(®->list); | |
179e0917 AM |
500 | else |
501 | list_move(®->list, &rh->quiesced_regions); | |
1da177e4 | 502 | |
1da177e4 LT |
503 | spin_unlock_irq(&rh->region_lock); |
504 | ||
505 | return 1; | |
506 | } | |
507 | ||
508 | static void rh_recovery_prepare(struct region_hash *rh) | |
509 | { | |
33184048 JB |
510 | /* Extra reference to avoid race with rh_stop_recovery */ |
511 | atomic_inc(&rh->recovery_in_flight); | |
512 | ||
513 | while (!down_trylock(&rh->recovery_count)) { | |
514 | atomic_inc(&rh->recovery_in_flight); | |
1da177e4 | 515 | if (__rh_recovery_prepare(rh) <= 0) { |
33184048 | 516 | atomic_dec(&rh->recovery_in_flight); |
1da177e4 LT |
517 | up(&rh->recovery_count); |
518 | break; | |
519 | } | |
33184048 JB |
520 | } |
521 | ||
522 | /* Drop the extra reference */ | |
523 | if (atomic_dec_and_test(&rh->recovery_in_flight)) | |
524 | wake_up_all(&_kmirrord_recovery_stopped); | |
1da177e4 LT |
525 | } |
526 | ||
527 | /* | |
528 | * Returns any quiesced regions. | |
529 | */ | |
530 | static struct region *rh_recovery_start(struct region_hash *rh) | |
531 | { | |
532 | struct region *reg = NULL; | |
533 | ||
534 | spin_lock_irq(&rh->region_lock); | |
535 | if (!list_empty(&rh->quiesced_regions)) { | |
536 | reg = list_entry(rh->quiesced_regions.next, | |
537 | struct region, list); | |
538 | list_del_init(®->list); /* remove from the quiesced list */ | |
539 | } | |
540 | spin_unlock_irq(&rh->region_lock); | |
541 | ||
542 | return reg; | |
543 | } | |
544 | ||
545 | /* FIXME: success ignored for now */ | |
546 | static void rh_recovery_end(struct region *reg, int success) | |
547 | { | |
548 | struct region_hash *rh = reg->rh; | |
549 | ||
550 | spin_lock_irq(&rh->region_lock); | |
551 | list_add(®->list, ®->rh->recovered_regions); | |
552 | spin_unlock_irq(&rh->region_lock); | |
553 | ||
554 | wake(); | |
555 | } | |
556 | ||
557 | static void rh_flush(struct region_hash *rh) | |
558 | { | |
559 | rh->log->type->flush(rh->log); | |
560 | } | |
561 | ||
562 | static void rh_delay(struct region_hash *rh, struct bio *bio) | |
563 | { | |
564 | struct region *reg; | |
565 | ||
566 | read_lock(&rh->hash_lock); | |
567 | reg = __rh_find(rh, bio_to_region(rh, bio)); | |
568 | bio_list_add(®->delayed_bios, bio); | |
569 | read_unlock(&rh->hash_lock); | |
570 | } | |
571 | ||
572 | static void rh_stop_recovery(struct region_hash *rh) | |
573 | { | |
574 | int i; | |
575 | ||
576 | /* wait for any recovering regions */ | |
577 | for (i = 0; i < MAX_RECOVERY; i++) | |
578 | down(&rh->recovery_count); | |
579 | } | |
580 | ||
581 | static void rh_start_recovery(struct region_hash *rh) | |
582 | { | |
583 | int i; | |
584 | ||
585 | for (i = 0; i < MAX_RECOVERY; i++) | |
586 | up(&rh->recovery_count); | |
587 | ||
588 | wake(); | |
589 | } | |
590 | ||
1da177e4 LT |
591 | /* |
592 | * Every mirror should look like this one. | |
593 | */ | |
594 | #define DEFAULT_MIRROR 0 | |
595 | ||
596 | /* | |
597 | * This is yucky. We squirrel the mirror_set struct away inside | |
598 | * bi_next for write buffers. This is safe since the bh | |
599 | * doesn't get submitted to the lower levels of block layer. | |
600 | */ | |
601 | static struct mirror_set *bio_get_ms(struct bio *bio) | |
602 | { | |
603 | return (struct mirror_set *) bio->bi_next; | |
604 | } | |
605 | ||
606 | static void bio_set_ms(struct bio *bio, struct mirror_set *ms) | |
607 | { | |
608 | bio->bi_next = (struct bio *) ms; | |
609 | } | |
610 | ||
611 | /*----------------------------------------------------------------- | |
612 | * Recovery. | |
613 | * | |
614 | * When a mirror is first activated we may find that some regions | |
615 | * are in the no-sync state. We have to recover these by | |
616 | * recopying from the default mirror to all the others. | |
617 | *---------------------------------------------------------------*/ | |
618 | static void recovery_complete(int read_err, unsigned int write_err, | |
619 | void *context) | |
620 | { | |
621 | struct region *reg = (struct region *) context; | |
622 | ||
623 | /* FIXME: better error handling */ | |
ce503f59 | 624 | rh_recovery_end(reg, !(read_err || write_err)); |
1da177e4 LT |
625 | } |
626 | ||
627 | static int recover(struct mirror_set *ms, struct region *reg) | |
628 | { | |
629 | int r; | |
630 | unsigned int i; | |
631 | struct io_region from, to[KCOPYD_MAX_REGIONS], *dest; | |
632 | struct mirror *m; | |
633 | unsigned long flags = 0; | |
634 | ||
635 | /* fill in the source */ | |
a1a19080 | 636 | m = ms->default_mirror; |
1da177e4 LT |
637 | from.bdev = m->dev->bdev; |
638 | from.sector = m->offset + region_to_sector(reg->rh, reg->key); | |
639 | if (reg->key == (ms->nr_regions - 1)) { | |
640 | /* | |
641 | * The final region may be smaller than | |
642 | * region_size. | |
643 | */ | |
644 | from.count = ms->ti->len & (reg->rh->region_size - 1); | |
645 | if (!from.count) | |
646 | from.count = reg->rh->region_size; | |
647 | } else | |
648 | from.count = reg->rh->region_size; | |
649 | ||
650 | /* fill in the destinations */ | |
651 | for (i = 0, dest = to; i < ms->nr_mirrors; i++) { | |
a1a19080 | 652 | if (&ms->mirror[i] == ms->default_mirror) |
1da177e4 LT |
653 | continue; |
654 | ||
655 | m = ms->mirror + i; | |
656 | dest->bdev = m->dev->bdev; | |
657 | dest->sector = m->offset + region_to_sector(reg->rh, reg->key); | |
658 | dest->count = from.count; | |
659 | dest++; | |
660 | } | |
661 | ||
662 | /* hand to kcopyd */ | |
663 | set_bit(KCOPYD_IGNORE_ERROR, &flags); | |
664 | r = kcopyd_copy(ms->kcopyd_client, &from, ms->nr_mirrors - 1, to, flags, | |
665 | recovery_complete, reg); | |
666 | ||
667 | return r; | |
668 | } | |
669 | ||
670 | static void do_recovery(struct mirror_set *ms) | |
671 | { | |
672 | int r; | |
673 | struct region *reg; | |
674 | struct dirty_log *log = ms->rh.log; | |
675 | ||
676 | /* | |
677 | * Start quiescing some regions. | |
678 | */ | |
679 | rh_recovery_prepare(&ms->rh); | |
680 | ||
681 | /* | |
682 | * Copy any already quiesced regions. | |
683 | */ | |
684 | while ((reg = rh_recovery_start(&ms->rh))) { | |
685 | r = recover(ms, reg); | |
686 | if (r) | |
687 | rh_recovery_end(reg, 0); | |
688 | } | |
689 | ||
690 | /* | |
691 | * Update the in sync flag. | |
692 | */ | |
693 | if (!ms->in_sync && | |
694 | (log->type->get_sync_count(log) == ms->nr_regions)) { | |
695 | /* the sync is complete */ | |
696 | dm_table_event(ms->ti->table); | |
697 | ms->in_sync = 1; | |
698 | } | |
699 | } | |
700 | ||
701 | /*----------------------------------------------------------------- | |
702 | * Reads | |
703 | *---------------------------------------------------------------*/ | |
704 | static struct mirror *choose_mirror(struct mirror_set *ms, sector_t sector) | |
705 | { | |
706 | /* FIXME: add read balancing */ | |
a1a19080 | 707 | return ms->default_mirror; |
1da177e4 LT |
708 | } |
709 | ||
710 | /* | |
711 | * remap a buffer to a particular mirror. | |
712 | */ | |
713 | static void map_bio(struct mirror_set *ms, struct mirror *m, struct bio *bio) | |
714 | { | |
715 | bio->bi_bdev = m->dev->bdev; | |
716 | bio->bi_sector = m->offset + (bio->bi_sector - ms->ti->begin); | |
717 | } | |
718 | ||
719 | static void do_reads(struct mirror_set *ms, struct bio_list *reads) | |
720 | { | |
721 | region_t region; | |
722 | struct bio *bio; | |
723 | struct mirror *m; | |
724 | ||
725 | while ((bio = bio_list_pop(reads))) { | |
726 | region = bio_to_region(&ms->rh, bio); | |
727 | ||
728 | /* | |
729 | * We can only read balance if the region is in sync. | |
730 | */ | |
731 | if (rh_in_sync(&ms->rh, region, 0)) | |
732 | m = choose_mirror(ms, bio->bi_sector); | |
733 | else | |
a1a19080 | 734 | m = ms->default_mirror; |
1da177e4 LT |
735 | |
736 | map_bio(ms, m, bio); | |
737 | generic_make_request(bio); | |
738 | } | |
739 | } | |
740 | ||
741 | /*----------------------------------------------------------------- | |
742 | * Writes. | |
743 | * | |
744 | * We do different things with the write io depending on the | |
745 | * state of the region that it's in: | |
746 | * | |
747 | * SYNC: increment pending, use kcopyd to write to *all* mirrors | |
748 | * RECOVERING: delay the io until recovery completes | |
749 | * NOSYNC: increment pending, just write to the default mirror | |
750 | *---------------------------------------------------------------*/ | |
751 | static void write_callback(unsigned long error, void *context) | |
752 | { | |
753 | unsigned int i; | |
754 | int uptodate = 1; | |
755 | struct bio *bio = (struct bio *) context; | |
756 | struct mirror_set *ms; | |
757 | ||
758 | ms = bio_get_ms(bio); | |
759 | bio_set_ms(bio, NULL); | |
760 | ||
761 | /* | |
762 | * NOTE: We don't decrement the pending count here, | |
763 | * instead it is done by the targets endio function. | |
764 | * This way we handle both writes to SYNC and NOSYNC | |
765 | * regions with the same code. | |
766 | */ | |
767 | ||
768 | if (error) { | |
769 | /* | |
770 | * only error the io if all mirrors failed. | |
771 | * FIXME: bogus | |
772 | */ | |
773 | uptodate = 0; | |
774 | for (i = 0; i < ms->nr_mirrors; i++) | |
775 | if (!test_bit(i, &error)) { | |
776 | uptodate = 1; | |
777 | break; | |
778 | } | |
779 | } | |
780 | bio_endio(bio, bio->bi_size, 0); | |
781 | } | |
782 | ||
783 | static void do_write(struct mirror_set *ms, struct bio *bio) | |
784 | { | |
785 | unsigned int i; | |
786 | struct io_region io[KCOPYD_MAX_REGIONS+1]; | |
787 | struct mirror *m; | |
788 | ||
789 | for (i = 0; i < ms->nr_mirrors; i++) { | |
790 | m = ms->mirror + i; | |
791 | ||
792 | io[i].bdev = m->dev->bdev; | |
793 | io[i].sector = m->offset + (bio->bi_sector - ms->ti->begin); | |
794 | io[i].count = bio->bi_size >> 9; | |
795 | } | |
796 | ||
797 | bio_set_ms(bio, ms); | |
798 | dm_io_async_bvec(ms->nr_mirrors, io, WRITE, | |
799 | bio->bi_io_vec + bio->bi_idx, | |
800 | write_callback, bio); | |
801 | } | |
802 | ||
803 | static void do_writes(struct mirror_set *ms, struct bio_list *writes) | |
804 | { | |
805 | int state; | |
806 | struct bio *bio; | |
807 | struct bio_list sync, nosync, recover, *this_list = NULL; | |
808 | ||
809 | if (!writes->head) | |
810 | return; | |
811 | ||
812 | /* | |
813 | * Classify each write. | |
814 | */ | |
815 | bio_list_init(&sync); | |
816 | bio_list_init(&nosync); | |
817 | bio_list_init(&recover); | |
818 | ||
819 | while ((bio = bio_list_pop(writes))) { | |
820 | state = rh_state(&ms->rh, bio_to_region(&ms->rh, bio), 1); | |
821 | switch (state) { | |
822 | case RH_CLEAN: | |
823 | case RH_DIRTY: | |
824 | this_list = &sync; | |
825 | break; | |
826 | ||
827 | case RH_NOSYNC: | |
828 | this_list = &nosync; | |
829 | break; | |
830 | ||
831 | case RH_RECOVERING: | |
832 | this_list = &recover; | |
833 | break; | |
834 | } | |
835 | ||
836 | bio_list_add(this_list, bio); | |
837 | } | |
838 | ||
839 | /* | |
840 | * Increment the pending counts for any regions that will | |
841 | * be written to (writes to recover regions are going to | |
842 | * be delayed). | |
843 | */ | |
844 | rh_inc_pending(&ms->rh, &sync); | |
845 | rh_inc_pending(&ms->rh, &nosync); | |
846 | rh_flush(&ms->rh); | |
847 | ||
848 | /* | |
849 | * Dispatch io. | |
850 | */ | |
851 | while ((bio = bio_list_pop(&sync))) | |
852 | do_write(ms, bio); | |
853 | ||
854 | while ((bio = bio_list_pop(&recover))) | |
855 | rh_delay(&ms->rh, bio); | |
856 | ||
857 | while ((bio = bio_list_pop(&nosync))) { | |
a1a19080 | 858 | map_bio(ms, ms->default_mirror, bio); |
1da177e4 LT |
859 | generic_make_request(bio); |
860 | } | |
861 | } | |
862 | ||
863 | /*----------------------------------------------------------------- | |
864 | * kmirrord | |
865 | *---------------------------------------------------------------*/ | |
866 | static LIST_HEAD(_mirror_sets); | |
867 | static DECLARE_RWSEM(_mirror_sets_lock); | |
868 | ||
869 | static void do_mirror(struct mirror_set *ms) | |
870 | { | |
871 | struct bio_list reads, writes; | |
872 | ||
873 | spin_lock(&ms->lock); | |
874 | reads = ms->reads; | |
875 | writes = ms->writes; | |
876 | bio_list_init(&ms->reads); | |
877 | bio_list_init(&ms->writes); | |
878 | spin_unlock(&ms->lock); | |
879 | ||
880 | rh_update_states(&ms->rh); | |
881 | do_recovery(ms); | |
882 | do_reads(ms, &reads); | |
883 | do_writes(ms, &writes); | |
884 | } | |
885 | ||
c4028958 | 886 | static void do_work(struct work_struct *ignored) |
1da177e4 LT |
887 | { |
888 | struct mirror_set *ms; | |
889 | ||
890 | down_read(&_mirror_sets_lock); | |
891 | list_for_each_entry (ms, &_mirror_sets, list) | |
892 | do_mirror(ms); | |
893 | up_read(&_mirror_sets_lock); | |
894 | } | |
895 | ||
896 | /*----------------------------------------------------------------- | |
897 | * Target functions | |
898 | *---------------------------------------------------------------*/ | |
899 | static struct mirror_set *alloc_context(unsigned int nr_mirrors, | |
900 | uint32_t region_size, | |
901 | struct dm_target *ti, | |
902 | struct dirty_log *dl) | |
903 | { | |
904 | size_t len; | |
905 | struct mirror_set *ms = NULL; | |
906 | ||
907 | if (array_too_big(sizeof(*ms), sizeof(ms->mirror[0]), nr_mirrors)) | |
908 | return NULL; | |
909 | ||
910 | len = sizeof(*ms) + (sizeof(ms->mirror[0]) * nr_mirrors); | |
911 | ||
912 | ms = kmalloc(len, GFP_KERNEL); | |
913 | if (!ms) { | |
72d94861 | 914 | ti->error = "Cannot allocate mirror context"; |
1da177e4 LT |
915 | return NULL; |
916 | } | |
917 | ||
918 | memset(ms, 0, len); | |
919 | spin_lock_init(&ms->lock); | |
920 | ||
921 | ms->ti = ti; | |
922 | ms->nr_mirrors = nr_mirrors; | |
923 | ms->nr_regions = dm_sector_div_up(ti->len, region_size); | |
924 | ms->in_sync = 0; | |
a1a19080 | 925 | ms->default_mirror = &ms->mirror[DEFAULT_MIRROR]; |
1da177e4 LT |
926 | |
927 | if (rh_init(&ms->rh, ms, dl, region_size, ms->nr_regions)) { | |
72d94861 | 928 | ti->error = "Error creating dirty region hash"; |
1da177e4 LT |
929 | kfree(ms); |
930 | return NULL; | |
931 | } | |
932 | ||
933 | return ms; | |
934 | } | |
935 | ||
936 | static void free_context(struct mirror_set *ms, struct dm_target *ti, | |
937 | unsigned int m) | |
938 | { | |
939 | while (m--) | |
940 | dm_put_device(ti, ms->mirror[m].dev); | |
941 | ||
942 | rh_exit(&ms->rh); | |
943 | kfree(ms); | |
944 | } | |
945 | ||
946 | static inline int _check_region_size(struct dm_target *ti, uint32_t size) | |
947 | { | |
948 | return !(size % (PAGE_SIZE >> 9) || (size & (size - 1)) || | |
949 | size > ti->len); | |
950 | } | |
951 | ||
952 | static int get_mirror(struct mirror_set *ms, struct dm_target *ti, | |
953 | unsigned int mirror, char **argv) | |
954 | { | |
4ee218cd | 955 | unsigned long long offset; |
1da177e4 | 956 | |
4ee218cd | 957 | if (sscanf(argv[1], "%llu", &offset) != 1) { |
72d94861 | 958 | ti->error = "Invalid offset"; |
1da177e4 LT |
959 | return -EINVAL; |
960 | } | |
961 | ||
962 | if (dm_get_device(ti, argv[0], offset, ti->len, | |
963 | dm_table_get_mode(ti->table), | |
964 | &ms->mirror[mirror].dev)) { | |
72d94861 | 965 | ti->error = "Device lookup failure"; |
1da177e4 LT |
966 | return -ENXIO; |
967 | } | |
968 | ||
969 | ms->mirror[mirror].offset = offset; | |
970 | ||
971 | return 0; | |
972 | } | |
973 | ||
974 | static int add_mirror_set(struct mirror_set *ms) | |
975 | { | |
976 | down_write(&_mirror_sets_lock); | |
977 | list_add_tail(&ms->list, &_mirror_sets); | |
978 | up_write(&_mirror_sets_lock); | |
979 | wake(); | |
980 | ||
981 | return 0; | |
982 | } | |
983 | ||
984 | static void del_mirror_set(struct mirror_set *ms) | |
985 | { | |
986 | down_write(&_mirror_sets_lock); | |
987 | list_del(&ms->list); | |
988 | up_write(&_mirror_sets_lock); | |
989 | } | |
990 | ||
991 | /* | |
992 | * Create dirty log: log_type #log_params <log_params> | |
993 | */ | |
994 | static struct dirty_log *create_dirty_log(struct dm_target *ti, | |
995 | unsigned int argc, char **argv, | |
996 | unsigned int *args_used) | |
997 | { | |
998 | unsigned int param_count; | |
999 | struct dirty_log *dl; | |
1000 | ||
1001 | if (argc < 2) { | |
72d94861 | 1002 | ti->error = "Insufficient mirror log arguments"; |
1da177e4 LT |
1003 | return NULL; |
1004 | } | |
1005 | ||
1006 | if (sscanf(argv[1], "%u", ¶m_count) != 1) { | |
72d94861 | 1007 | ti->error = "Invalid mirror log argument count"; |
1da177e4 LT |
1008 | return NULL; |
1009 | } | |
1010 | ||
1011 | *args_used = 2 + param_count; | |
1012 | ||
1013 | if (argc < *args_used) { | |
72d94861 | 1014 | ti->error = "Insufficient mirror log arguments"; |
1da177e4 LT |
1015 | return NULL; |
1016 | } | |
1017 | ||
1018 | dl = dm_create_dirty_log(argv[0], ti, param_count, argv + 2); | |
1019 | if (!dl) { | |
72d94861 | 1020 | ti->error = "Error creating mirror dirty log"; |
1da177e4 LT |
1021 | return NULL; |
1022 | } | |
1023 | ||
1024 | if (!_check_region_size(ti, dl->type->get_region_size(dl))) { | |
72d94861 | 1025 | ti->error = "Invalid region size"; |
1da177e4 LT |
1026 | dm_destroy_dirty_log(dl); |
1027 | return NULL; | |
1028 | } | |
1029 | ||
1030 | return dl; | |
1031 | } | |
1032 | ||
1033 | /* | |
1034 | * Construct a mirror mapping: | |
1035 | * | |
1036 | * log_type #log_params <log_params> | |
1037 | * #mirrors [mirror_path offset]{2,} | |
1038 | * | |
1039 | * log_type is "core" or "disk" | |
1040 | * #log_params is between 1 and 3 | |
1041 | */ | |
1042 | #define DM_IO_PAGES 64 | |
1043 | static int mirror_ctr(struct dm_target *ti, unsigned int argc, char **argv) | |
1044 | { | |
1045 | int r; | |
1046 | unsigned int nr_mirrors, m, args_used; | |
1047 | struct mirror_set *ms; | |
1048 | struct dirty_log *dl; | |
1049 | ||
1050 | dl = create_dirty_log(ti, argc, argv, &args_used); | |
1051 | if (!dl) | |
1052 | return -EINVAL; | |
1053 | ||
1054 | argv += args_used; | |
1055 | argc -= args_used; | |
1056 | ||
1057 | if (!argc || sscanf(argv[0], "%u", &nr_mirrors) != 1 || | |
1058 | nr_mirrors < 2 || nr_mirrors > KCOPYD_MAX_REGIONS + 1) { | |
72d94861 | 1059 | ti->error = "Invalid number of mirrors"; |
1da177e4 LT |
1060 | dm_destroy_dirty_log(dl); |
1061 | return -EINVAL; | |
1062 | } | |
1063 | ||
1064 | argv++, argc--; | |
1065 | ||
1066 | if (argc != nr_mirrors * 2) { | |
72d94861 | 1067 | ti->error = "Wrong number of mirror arguments"; |
1da177e4 LT |
1068 | dm_destroy_dirty_log(dl); |
1069 | return -EINVAL; | |
1070 | } | |
1071 | ||
1072 | ms = alloc_context(nr_mirrors, dl->type->get_region_size(dl), ti, dl); | |
1073 | if (!ms) { | |
1074 | dm_destroy_dirty_log(dl); | |
1075 | return -ENOMEM; | |
1076 | } | |
1077 | ||
1078 | /* Get the mirror parameter sets */ | |
1079 | for (m = 0; m < nr_mirrors; m++) { | |
1080 | r = get_mirror(ms, ti, m, argv); | |
1081 | if (r) { | |
1082 | free_context(ms, ti, m); | |
1083 | return r; | |
1084 | } | |
1085 | argv += 2; | |
1086 | argc -= 2; | |
1087 | } | |
1088 | ||
1089 | ti->private = ms; | |
d88854f0 | 1090 | ti->split_io = ms->rh.region_size; |
1da177e4 LT |
1091 | |
1092 | r = kcopyd_client_create(DM_IO_PAGES, &ms->kcopyd_client); | |
1093 | if (r) { | |
1094 | free_context(ms, ti, ms->nr_mirrors); | |
1095 | return r; | |
1096 | } | |
1097 | ||
1098 | add_mirror_set(ms); | |
1099 | return 0; | |
1100 | } | |
1101 | ||
1102 | static void mirror_dtr(struct dm_target *ti) | |
1103 | { | |
1104 | struct mirror_set *ms = (struct mirror_set *) ti->private; | |
1105 | ||
1106 | del_mirror_set(ms); | |
1107 | kcopyd_client_destroy(ms->kcopyd_client); | |
1108 | free_context(ms, ti, ms->nr_mirrors); | |
1109 | } | |
1110 | ||
1111 | static void queue_bio(struct mirror_set *ms, struct bio *bio, int rw) | |
1112 | { | |
1113 | int should_wake = 0; | |
1114 | struct bio_list *bl; | |
1115 | ||
1116 | bl = (rw == WRITE) ? &ms->writes : &ms->reads; | |
1117 | spin_lock(&ms->lock); | |
1118 | should_wake = !(bl->head); | |
1119 | bio_list_add(bl, bio); | |
1120 | spin_unlock(&ms->lock); | |
1121 | ||
1122 | if (should_wake) | |
1123 | wake(); | |
1124 | } | |
1125 | ||
1126 | /* | |
1127 | * Mirror mapping function | |
1128 | */ | |
1129 | static int mirror_map(struct dm_target *ti, struct bio *bio, | |
1130 | union map_info *map_context) | |
1131 | { | |
1132 | int r, rw = bio_rw(bio); | |
1133 | struct mirror *m; | |
1134 | struct mirror_set *ms = ti->private; | |
1135 | ||
e4c8b3ba | 1136 | map_context->ll = bio_to_region(&ms->rh, bio); |
1da177e4 LT |
1137 | |
1138 | if (rw == WRITE) { | |
1139 | queue_bio(ms, bio, rw); | |
1140 | return 0; | |
1141 | } | |
1142 | ||
1143 | r = ms->rh.log->type->in_sync(ms->rh.log, | |
1144 | bio_to_region(&ms->rh, bio), 0); | |
1145 | if (r < 0 && r != -EWOULDBLOCK) | |
1146 | return r; | |
1147 | ||
1148 | if (r == -EWOULDBLOCK) /* FIXME: ugly */ | |
1149 | r = 0; | |
1150 | ||
1151 | /* | |
1152 | * We don't want to fast track a recovery just for a read | |
1153 | * ahead. So we just let it silently fail. | |
1154 | * FIXME: get rid of this. | |
1155 | */ | |
1156 | if (!r && rw == READA) | |
1157 | return -EIO; | |
1158 | ||
1159 | if (!r) { | |
1160 | /* Pass this io over to the daemon */ | |
1161 | queue_bio(ms, bio, rw); | |
1162 | return 0; | |
1163 | } | |
1164 | ||
1165 | m = choose_mirror(ms, bio->bi_sector); | |
1166 | if (!m) | |
1167 | return -EIO; | |
1168 | ||
1169 | map_bio(ms, m, bio); | |
1170 | return 1; | |
1171 | } | |
1172 | ||
1173 | static int mirror_end_io(struct dm_target *ti, struct bio *bio, | |
1174 | int error, union map_info *map_context) | |
1175 | { | |
1176 | int rw = bio_rw(bio); | |
1177 | struct mirror_set *ms = (struct mirror_set *) ti->private; | |
1178 | region_t region = map_context->ll; | |
1179 | ||
1180 | /* | |
1181 | * We need to dec pending if this was a write. | |
1182 | */ | |
1183 | if (rw == WRITE) | |
1184 | rh_dec(&ms->rh, region); | |
1185 | ||
1186 | return 0; | |
1187 | } | |
1188 | ||
1189 | static void mirror_postsuspend(struct dm_target *ti) | |
1190 | { | |
1191 | struct mirror_set *ms = (struct mirror_set *) ti->private; | |
1192 | struct dirty_log *log = ms->rh.log; | |
1193 | ||
1194 | rh_stop_recovery(&ms->rh); | |
33184048 JB |
1195 | |
1196 | /* Wait for all I/O we generated to complete */ | |
1197 | wait_event(_kmirrord_recovery_stopped, | |
1198 | !atomic_read(&ms->rh.recovery_in_flight)); | |
1199 | ||
1da177e4 LT |
1200 | if (log->type->suspend && log->type->suspend(log)) |
1201 | /* FIXME: need better error handling */ | |
1202 | DMWARN("log suspend failed"); | |
1203 | } | |
1204 | ||
1205 | static void mirror_resume(struct dm_target *ti) | |
1206 | { | |
1207 | struct mirror_set *ms = (struct mirror_set *) ti->private; | |
1208 | struct dirty_log *log = ms->rh.log; | |
1209 | if (log->type->resume && log->type->resume(log)) | |
1210 | /* FIXME: need better error handling */ | |
1211 | DMWARN("log resume failed"); | |
1212 | rh_start_recovery(&ms->rh); | |
1213 | } | |
1214 | ||
1215 | static int mirror_status(struct dm_target *ti, status_type_t type, | |
1216 | char *result, unsigned int maxlen) | |
1217 | { | |
1218 | unsigned int m, sz; | |
1219 | struct mirror_set *ms = (struct mirror_set *) ti->private; | |
1220 | ||
1221 | sz = ms->rh.log->type->status(ms->rh.log, type, result, maxlen); | |
1222 | ||
1223 | switch (type) { | |
1224 | case STATUSTYPE_INFO: | |
1225 | DMEMIT("%d ", ms->nr_mirrors); | |
1226 | for (m = 0; m < ms->nr_mirrors; m++) | |
1227 | DMEMIT("%s ", ms->mirror[m].dev->name); | |
1228 | ||
4ee218cd AM |
1229 | DMEMIT("%llu/%llu", |
1230 | (unsigned long long)ms->rh.log->type-> | |
1231 | get_sync_count(ms->rh.log), | |
1232 | (unsigned long long)ms->nr_regions); | |
1da177e4 LT |
1233 | break; |
1234 | ||
1235 | case STATUSTYPE_TABLE: | |
e52b8f6d | 1236 | DMEMIT("%d", ms->nr_mirrors); |
1da177e4 | 1237 | for (m = 0; m < ms->nr_mirrors; m++) |
e52b8f6d | 1238 | DMEMIT(" %s %llu", ms->mirror[m].dev->name, |
4ee218cd | 1239 | (unsigned long long)ms->mirror[m].offset); |
1da177e4 LT |
1240 | } |
1241 | ||
1242 | return 0; | |
1243 | } | |
1244 | ||
1245 | static struct target_type mirror_target = { | |
1246 | .name = "mirror", | |
702ca6f0 | 1247 | .version = {1, 0, 2}, |
1da177e4 LT |
1248 | .module = THIS_MODULE, |
1249 | .ctr = mirror_ctr, | |
1250 | .dtr = mirror_dtr, | |
1251 | .map = mirror_map, | |
1252 | .end_io = mirror_end_io, | |
1253 | .postsuspend = mirror_postsuspend, | |
1254 | .resume = mirror_resume, | |
1255 | .status = mirror_status, | |
1256 | }; | |
1257 | ||
1258 | static int __init dm_mirror_init(void) | |
1259 | { | |
1260 | int r; | |
1261 | ||
1262 | r = dm_dirty_log_init(); | |
1263 | if (r) | |
1264 | return r; | |
1265 | ||
48f1f532 | 1266 | _kmirrord_wq = create_singlethread_workqueue("kmirrord"); |
1da177e4 LT |
1267 | if (!_kmirrord_wq) { |
1268 | DMERR("couldn't start kmirrord"); | |
1269 | dm_dirty_log_exit(); | |
1270 | return r; | |
1271 | } | |
c4028958 | 1272 | INIT_WORK(&_kmirrord_work, do_work); |
1da177e4 LT |
1273 | |
1274 | r = dm_register_target(&mirror_target); | |
1275 | if (r < 0) { | |
1276 | DMERR("%s: Failed to register mirror target", | |
1277 | mirror_target.name); | |
1278 | dm_dirty_log_exit(); | |
1279 | destroy_workqueue(_kmirrord_wq); | |
1280 | } | |
1281 | ||
1282 | return r; | |
1283 | } | |
1284 | ||
1285 | static void __exit dm_mirror_exit(void) | |
1286 | { | |
1287 | int r; | |
1288 | ||
1289 | r = dm_unregister_target(&mirror_target); | |
1290 | if (r < 0) | |
1291 | DMERR("%s: unregister failed %d", mirror_target.name, r); | |
1292 | ||
1293 | destroy_workqueue(_kmirrord_wq); | |
1294 | dm_dirty_log_exit(); | |
1295 | } | |
1296 | ||
1297 | /* Module hooks */ | |
1298 | module_init(dm_mirror_init); | |
1299 | module_exit(dm_mirror_exit); | |
1300 | ||
1301 | MODULE_DESCRIPTION(DM_NAME " mirror target"); | |
1302 | MODULE_AUTHOR("Joe Thornber"); | |
1303 | MODULE_LICENSE("GPL"); |