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