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1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2002 Sistina Software (UK) Limited. | |
3 | * | |
4 | * This file is released under the GPL. | |
5 | * | |
6 | * Kcopyd provides a simple interface for copying an area of one | |
7 | * block-device to one or more other block-devices, with an asynchronous | |
8 | * completion notification. | |
9 | */ | |
10 | ||
715b49ef | 11 | #include <asm/types.h> |
1da177e4 LT |
12 | #include <asm/atomic.h> |
13 | ||
14 | #include <linux/blkdev.h> | |
1da177e4 LT |
15 | #include <linux/fs.h> |
16 | #include <linux/init.h> | |
17 | #include <linux/list.h> | |
18 | #include <linux/mempool.h> | |
19 | #include <linux/module.h> | |
20 | #include <linux/pagemap.h> | |
21 | #include <linux/slab.h> | |
22 | #include <linux/vmalloc.h> | |
23 | #include <linux/workqueue.h> | |
48c9c27b | 24 | #include <linux/mutex.h> |
1da177e4 LT |
25 | |
26 | #include "kcopyd.h" | |
27 | ||
28 | static struct workqueue_struct *_kcopyd_wq; | |
29 | static struct work_struct _kcopyd_work; | |
30 | ||
31 | static inline void wake(void) | |
32 | { | |
33 | queue_work(_kcopyd_wq, &_kcopyd_work); | |
34 | } | |
35 | ||
36 | /*----------------------------------------------------------------- | |
37 | * Each kcopyd client has its own little pool of preallocated | |
38 | * pages for kcopyd io. | |
39 | *---------------------------------------------------------------*/ | |
40 | struct kcopyd_client { | |
41 | struct list_head list; | |
42 | ||
43 | spinlock_t lock; | |
44 | struct page_list *pages; | |
45 | unsigned int nr_pages; | |
46 | unsigned int nr_free_pages; | |
138728dc AK |
47 | |
48 | wait_queue_head_t destroyq; | |
49 | atomic_t nr_jobs; | |
1da177e4 LT |
50 | }; |
51 | ||
52 | static struct page_list *alloc_pl(void) | |
53 | { | |
54 | struct page_list *pl; | |
55 | ||
56 | pl = kmalloc(sizeof(*pl), GFP_KERNEL); | |
57 | if (!pl) | |
58 | return NULL; | |
59 | ||
60 | pl->page = alloc_page(GFP_KERNEL); | |
61 | if (!pl->page) { | |
62 | kfree(pl); | |
63 | return NULL; | |
64 | } | |
65 | ||
66 | return pl; | |
67 | } | |
68 | ||
69 | static void free_pl(struct page_list *pl) | |
70 | { | |
71 | __free_page(pl->page); | |
72 | kfree(pl); | |
73 | } | |
74 | ||
75 | static int kcopyd_get_pages(struct kcopyd_client *kc, | |
76 | unsigned int nr, struct page_list **pages) | |
77 | { | |
78 | struct page_list *pl; | |
79 | ||
80 | spin_lock(&kc->lock); | |
81 | if (kc->nr_free_pages < nr) { | |
82 | spin_unlock(&kc->lock); | |
83 | return -ENOMEM; | |
84 | } | |
85 | ||
86 | kc->nr_free_pages -= nr; | |
87 | for (*pages = pl = kc->pages; --nr; pl = pl->next) | |
88 | ; | |
89 | ||
90 | kc->pages = pl->next; | |
91 | pl->next = NULL; | |
92 | ||
93 | spin_unlock(&kc->lock); | |
94 | ||
95 | return 0; | |
96 | } | |
97 | ||
98 | static void kcopyd_put_pages(struct kcopyd_client *kc, struct page_list *pl) | |
99 | { | |
100 | struct page_list *cursor; | |
101 | ||
102 | spin_lock(&kc->lock); | |
103 | for (cursor = pl; cursor->next; cursor = cursor->next) | |
104 | kc->nr_free_pages++; | |
105 | ||
106 | kc->nr_free_pages++; | |
107 | cursor->next = kc->pages; | |
108 | kc->pages = pl; | |
109 | spin_unlock(&kc->lock); | |
110 | } | |
111 | ||
112 | /* | |
113 | * These three functions resize the page pool. | |
114 | */ | |
115 | static void drop_pages(struct page_list *pl) | |
116 | { | |
117 | struct page_list *next; | |
118 | ||
119 | while (pl) { | |
120 | next = pl->next; | |
121 | free_pl(pl); | |
122 | pl = next; | |
123 | } | |
124 | } | |
125 | ||
126 | static int client_alloc_pages(struct kcopyd_client *kc, unsigned int nr) | |
127 | { | |
128 | unsigned int i; | |
129 | struct page_list *pl = NULL, *next; | |
130 | ||
131 | for (i = 0; i < nr; i++) { | |
132 | next = alloc_pl(); | |
133 | if (!next) { | |
134 | if (pl) | |
135 | drop_pages(pl); | |
136 | return -ENOMEM; | |
137 | } | |
138 | next->next = pl; | |
139 | pl = next; | |
140 | } | |
141 | ||
142 | kcopyd_put_pages(kc, pl); | |
143 | kc->nr_pages += nr; | |
144 | return 0; | |
145 | } | |
146 | ||
147 | static void client_free_pages(struct kcopyd_client *kc) | |
148 | { | |
149 | BUG_ON(kc->nr_free_pages != kc->nr_pages); | |
150 | drop_pages(kc->pages); | |
151 | kc->pages = NULL; | |
152 | kc->nr_free_pages = kc->nr_pages = 0; | |
153 | } | |
154 | ||
155 | /*----------------------------------------------------------------- | |
156 | * kcopyd_jobs need to be allocated by the *clients* of kcopyd, | |
157 | * for this reason we use a mempool to prevent the client from | |
158 | * ever having to do io (which could cause a deadlock). | |
159 | *---------------------------------------------------------------*/ | |
160 | struct kcopyd_job { | |
161 | struct kcopyd_client *kc; | |
162 | struct list_head list; | |
163 | unsigned long flags; | |
164 | ||
165 | /* | |
166 | * Error state of the job. | |
167 | */ | |
168 | int read_err; | |
169 | unsigned int write_err; | |
170 | ||
171 | /* | |
172 | * Either READ or WRITE | |
173 | */ | |
174 | int rw; | |
175 | struct io_region source; | |
176 | ||
177 | /* | |
178 | * The destinations for the transfer. | |
179 | */ | |
180 | unsigned int num_dests; | |
181 | struct io_region dests[KCOPYD_MAX_REGIONS]; | |
182 | ||
183 | sector_t offset; | |
184 | unsigned int nr_pages; | |
185 | struct page_list *pages; | |
186 | ||
187 | /* | |
188 | * Set this to ensure you are notified when the job has | |
189 | * completed. 'context' is for callback to use. | |
190 | */ | |
191 | kcopyd_notify_fn fn; | |
192 | void *context; | |
193 | ||
194 | /* | |
195 | * These fields are only used if the job has been split | |
196 | * into more manageable parts. | |
197 | */ | |
198 | struct semaphore lock; | |
199 | atomic_t sub_jobs; | |
200 | sector_t progress; | |
201 | }; | |
202 | ||
203 | /* FIXME: this should scale with the number of pages */ | |
204 | #define MIN_JOBS 512 | |
205 | ||
206 | static kmem_cache_t *_job_cache; | |
207 | static mempool_t *_job_pool; | |
208 | ||
209 | /* | |
210 | * We maintain three lists of jobs: | |
211 | * | |
212 | * i) jobs waiting for pages | |
213 | * ii) jobs that have pages, and are waiting for the io to be issued. | |
214 | * iii) jobs that have completed. | |
215 | * | |
216 | * All three of these are protected by job_lock. | |
217 | */ | |
218 | static DEFINE_SPINLOCK(_job_lock); | |
219 | ||
220 | static LIST_HEAD(_complete_jobs); | |
221 | static LIST_HEAD(_io_jobs); | |
222 | static LIST_HEAD(_pages_jobs); | |
223 | ||
224 | static int jobs_init(void) | |
225 | { | |
226 | _job_cache = kmem_cache_create("kcopyd-jobs", | |
227 | sizeof(struct kcopyd_job), | |
228 | __alignof__(struct kcopyd_job), | |
229 | 0, NULL, NULL); | |
230 | if (!_job_cache) | |
231 | return -ENOMEM; | |
232 | ||
93d2341c | 233 | _job_pool = mempool_create_slab_pool(MIN_JOBS, _job_cache); |
1da177e4 LT |
234 | if (!_job_pool) { |
235 | kmem_cache_destroy(_job_cache); | |
236 | return -ENOMEM; | |
237 | } | |
238 | ||
239 | return 0; | |
240 | } | |
241 | ||
242 | static void jobs_exit(void) | |
243 | { | |
244 | BUG_ON(!list_empty(&_complete_jobs)); | |
245 | BUG_ON(!list_empty(&_io_jobs)); | |
246 | BUG_ON(!list_empty(&_pages_jobs)); | |
247 | ||
248 | mempool_destroy(_job_pool); | |
249 | kmem_cache_destroy(_job_cache); | |
250 | _job_pool = NULL; | |
251 | _job_cache = NULL; | |
252 | } | |
253 | ||
254 | /* | |
255 | * Functions to push and pop a job onto the head of a given job | |
256 | * list. | |
257 | */ | |
258 | static inline struct kcopyd_job *pop(struct list_head *jobs) | |
259 | { | |
260 | struct kcopyd_job *job = NULL; | |
261 | unsigned long flags; | |
262 | ||
263 | spin_lock_irqsave(&_job_lock, flags); | |
264 | ||
265 | if (!list_empty(jobs)) { | |
266 | job = list_entry(jobs->next, struct kcopyd_job, list); | |
267 | list_del(&job->list); | |
268 | } | |
269 | spin_unlock_irqrestore(&_job_lock, flags); | |
270 | ||
271 | return job; | |
272 | } | |
273 | ||
274 | static inline void push(struct list_head *jobs, struct kcopyd_job *job) | |
275 | { | |
276 | unsigned long flags; | |
277 | ||
278 | spin_lock_irqsave(&_job_lock, flags); | |
279 | list_add_tail(&job->list, jobs); | |
280 | spin_unlock_irqrestore(&_job_lock, flags); | |
281 | } | |
282 | ||
283 | /* | |
284 | * These three functions process 1 item from the corresponding | |
285 | * job list. | |
286 | * | |
287 | * They return: | |
288 | * < 0: error | |
289 | * 0: success | |
290 | * > 0: can't process yet. | |
291 | */ | |
292 | static int run_complete_job(struct kcopyd_job *job) | |
293 | { | |
294 | void *context = job->context; | |
295 | int read_err = job->read_err; | |
296 | unsigned int write_err = job->write_err; | |
297 | kcopyd_notify_fn fn = job->fn; | |
138728dc | 298 | struct kcopyd_client *kc = job->kc; |
1da177e4 | 299 | |
138728dc | 300 | kcopyd_put_pages(kc, job->pages); |
1da177e4 LT |
301 | mempool_free(job, _job_pool); |
302 | fn(read_err, write_err, context); | |
138728dc AK |
303 | |
304 | if (atomic_dec_and_test(&kc->nr_jobs)) | |
305 | wake_up(&kc->destroyq); | |
306 | ||
1da177e4 LT |
307 | return 0; |
308 | } | |
309 | ||
310 | static void complete_io(unsigned long error, void *context) | |
311 | { | |
312 | struct kcopyd_job *job = (struct kcopyd_job *) context; | |
313 | ||
314 | if (error) { | |
315 | if (job->rw == WRITE) | |
ce503f59 | 316 | job->write_err |= error; |
1da177e4 LT |
317 | else |
318 | job->read_err = 1; | |
319 | ||
320 | if (!test_bit(KCOPYD_IGNORE_ERROR, &job->flags)) { | |
321 | push(&_complete_jobs, job); | |
322 | wake(); | |
323 | return; | |
324 | } | |
325 | } | |
326 | ||
327 | if (job->rw == WRITE) | |
328 | push(&_complete_jobs, job); | |
329 | ||
330 | else { | |
331 | job->rw = WRITE; | |
332 | push(&_io_jobs, job); | |
333 | } | |
334 | ||
335 | wake(); | |
336 | } | |
337 | ||
338 | /* | |
339 | * Request io on as many buffer heads as we can currently get for | |
340 | * a particular job. | |
341 | */ | |
342 | static int run_io_job(struct kcopyd_job *job) | |
343 | { | |
344 | int r; | |
345 | ||
346 | if (job->rw == READ) | |
347 | r = dm_io_async(1, &job->source, job->rw, | |
348 | job->pages, | |
349 | job->offset, complete_io, job); | |
350 | ||
351 | else | |
352 | r = dm_io_async(job->num_dests, job->dests, job->rw, | |
353 | job->pages, | |
354 | job->offset, complete_io, job); | |
355 | ||
356 | return r; | |
357 | } | |
358 | ||
359 | static int run_pages_job(struct kcopyd_job *job) | |
360 | { | |
361 | int r; | |
362 | ||
363 | job->nr_pages = dm_div_up(job->dests[0].count + job->offset, | |
364 | PAGE_SIZE >> 9); | |
365 | r = kcopyd_get_pages(job->kc, job->nr_pages, &job->pages); | |
366 | if (!r) { | |
367 | /* this job is ready for io */ | |
368 | push(&_io_jobs, job); | |
369 | return 0; | |
370 | } | |
371 | ||
372 | if (r == -ENOMEM) | |
373 | /* can't complete now */ | |
374 | return 1; | |
375 | ||
376 | return r; | |
377 | } | |
378 | ||
379 | /* | |
380 | * Run through a list for as long as possible. Returns the count | |
381 | * of successful jobs. | |
382 | */ | |
383 | static int process_jobs(struct list_head *jobs, int (*fn) (struct kcopyd_job *)) | |
384 | { | |
385 | struct kcopyd_job *job; | |
386 | int r, count = 0; | |
387 | ||
388 | while ((job = pop(jobs))) { | |
389 | ||
390 | r = fn(job); | |
391 | ||
392 | if (r < 0) { | |
393 | /* error this rogue job */ | |
394 | if (job->rw == WRITE) | |
395 | job->write_err = (unsigned int) -1; | |
396 | else | |
397 | job->read_err = 1; | |
398 | push(&_complete_jobs, job); | |
399 | break; | |
400 | } | |
401 | ||
402 | if (r > 0) { | |
403 | /* | |
404 | * We couldn't service this job ATM, so | |
405 | * push this job back onto the list. | |
406 | */ | |
407 | push(jobs, job); | |
408 | break; | |
409 | } | |
410 | ||
411 | count++; | |
412 | } | |
413 | ||
414 | return count; | |
415 | } | |
416 | ||
417 | /* | |
418 | * kcopyd does this every time it's woken up. | |
419 | */ | |
420 | static void do_work(void *ignored) | |
421 | { | |
422 | /* | |
423 | * The order that these are called is *very* important. | |
424 | * complete jobs can free some pages for pages jobs. | |
425 | * Pages jobs when successful will jump onto the io jobs | |
426 | * list. io jobs call wake when they complete and it all | |
427 | * starts again. | |
428 | */ | |
429 | process_jobs(&_complete_jobs, run_complete_job); | |
430 | process_jobs(&_pages_jobs, run_pages_job); | |
431 | process_jobs(&_io_jobs, run_io_job); | |
432 | } | |
433 | ||
434 | /* | |
435 | * If we are copying a small region we just dispatch a single job | |
436 | * to do the copy, otherwise the io has to be split up into many | |
437 | * jobs. | |
438 | */ | |
439 | static void dispatch_job(struct kcopyd_job *job) | |
440 | { | |
138728dc | 441 | atomic_inc(&job->kc->nr_jobs); |
1da177e4 LT |
442 | push(&_pages_jobs, job); |
443 | wake(); | |
444 | } | |
445 | ||
446 | #define SUB_JOB_SIZE 128 | |
447 | static void segment_complete(int read_err, | |
448 | unsigned int write_err, void *context) | |
449 | { | |
450 | /* FIXME: tidy this function */ | |
451 | sector_t progress = 0; | |
452 | sector_t count = 0; | |
453 | struct kcopyd_job *job = (struct kcopyd_job *) context; | |
454 | ||
455 | down(&job->lock); | |
456 | ||
457 | /* update the error */ | |
458 | if (read_err) | |
459 | job->read_err = 1; | |
460 | ||
461 | if (write_err) | |
ce503f59 | 462 | job->write_err |= write_err; |
1da177e4 LT |
463 | |
464 | /* | |
465 | * Only dispatch more work if there hasn't been an error. | |
466 | */ | |
467 | if ((!job->read_err && !job->write_err) || | |
468 | test_bit(KCOPYD_IGNORE_ERROR, &job->flags)) { | |
469 | /* get the next chunk of work */ | |
470 | progress = job->progress; | |
471 | count = job->source.count - progress; | |
472 | if (count) { | |
473 | if (count > SUB_JOB_SIZE) | |
474 | count = SUB_JOB_SIZE; | |
475 | ||
476 | job->progress += count; | |
477 | } | |
478 | } | |
479 | up(&job->lock); | |
480 | ||
481 | if (count) { | |
482 | int i; | |
483 | struct kcopyd_job *sub_job = mempool_alloc(_job_pool, GFP_NOIO); | |
484 | ||
485 | *sub_job = *job; | |
486 | sub_job->source.sector += progress; | |
487 | sub_job->source.count = count; | |
488 | ||
489 | for (i = 0; i < job->num_dests; i++) { | |
490 | sub_job->dests[i].sector += progress; | |
491 | sub_job->dests[i].count = count; | |
492 | } | |
493 | ||
494 | sub_job->fn = segment_complete; | |
495 | sub_job->context = job; | |
496 | dispatch_job(sub_job); | |
497 | ||
498 | } else if (atomic_dec_and_test(&job->sub_jobs)) { | |
499 | ||
500 | /* | |
501 | * To avoid a race we must keep the job around | |
502 | * until after the notify function has completed. | |
503 | * Otherwise the client may try and stop the job | |
504 | * after we've completed. | |
505 | */ | |
506 | job->fn(read_err, write_err, job->context); | |
507 | mempool_free(job, _job_pool); | |
508 | } | |
509 | } | |
510 | ||
511 | /* | |
512 | * Create some little jobs that will do the move between | |
513 | * them. | |
514 | */ | |
515 | #define SPLIT_COUNT 8 | |
516 | static void split_job(struct kcopyd_job *job) | |
517 | { | |
518 | int i; | |
519 | ||
520 | atomic_set(&job->sub_jobs, SPLIT_COUNT); | |
521 | for (i = 0; i < SPLIT_COUNT; i++) | |
522 | segment_complete(0, 0u, job); | |
523 | } | |
524 | ||
525 | int kcopyd_copy(struct kcopyd_client *kc, struct io_region *from, | |
526 | unsigned int num_dests, struct io_region *dests, | |
527 | unsigned int flags, kcopyd_notify_fn fn, void *context) | |
528 | { | |
529 | struct kcopyd_job *job; | |
530 | ||
531 | /* | |
532 | * Allocate a new job. | |
533 | */ | |
534 | job = mempool_alloc(_job_pool, GFP_NOIO); | |
535 | ||
536 | /* | |
537 | * set up for the read. | |
538 | */ | |
539 | job->kc = kc; | |
540 | job->flags = flags; | |
541 | job->read_err = 0; | |
542 | job->write_err = 0; | |
543 | job->rw = READ; | |
544 | ||
545 | job->source = *from; | |
546 | ||
547 | job->num_dests = num_dests; | |
548 | memcpy(&job->dests, dests, sizeof(*dests) * num_dests); | |
549 | ||
550 | job->offset = 0; | |
551 | job->nr_pages = 0; | |
552 | job->pages = NULL; | |
553 | ||
554 | job->fn = fn; | |
555 | job->context = context; | |
556 | ||
557 | if (job->source.count < SUB_JOB_SIZE) | |
558 | dispatch_job(job); | |
559 | ||
560 | else { | |
561 | init_MUTEX(&job->lock); | |
562 | job->progress = 0; | |
563 | split_job(job); | |
564 | } | |
565 | ||
566 | return 0; | |
567 | } | |
568 | ||
569 | /* | |
570 | * Cancels a kcopyd job, eg. someone might be deactivating a | |
571 | * mirror. | |
572 | */ | |
0b56306e | 573 | #if 0 |
1da177e4 LT |
574 | int kcopyd_cancel(struct kcopyd_job *job, int block) |
575 | { | |
576 | /* FIXME: finish */ | |
577 | return -1; | |
578 | } | |
0b56306e | 579 | #endif /* 0 */ |
1da177e4 LT |
580 | |
581 | /*----------------------------------------------------------------- | |
582 | * Unit setup | |
583 | *---------------------------------------------------------------*/ | |
48c9c27b | 584 | static DEFINE_MUTEX(_client_lock); |
1da177e4 LT |
585 | static LIST_HEAD(_clients); |
586 | ||
587 | static void client_add(struct kcopyd_client *kc) | |
588 | { | |
48c9c27b | 589 | mutex_lock(&_client_lock); |
1da177e4 | 590 | list_add(&kc->list, &_clients); |
48c9c27b | 591 | mutex_unlock(&_client_lock); |
1da177e4 LT |
592 | } |
593 | ||
594 | static void client_del(struct kcopyd_client *kc) | |
595 | { | |
48c9c27b | 596 | mutex_lock(&_client_lock); |
1da177e4 | 597 | list_del(&kc->list); |
48c9c27b | 598 | mutex_unlock(&_client_lock); |
1da177e4 LT |
599 | } |
600 | ||
14cc3e2b | 601 | static DEFINE_MUTEX(kcopyd_init_lock); |
1da177e4 LT |
602 | static int kcopyd_clients = 0; |
603 | ||
604 | static int kcopyd_init(void) | |
605 | { | |
606 | int r; | |
607 | ||
14cc3e2b | 608 | mutex_lock(&kcopyd_init_lock); |
1da177e4 LT |
609 | |
610 | if (kcopyd_clients) { | |
611 | /* Already initialized. */ | |
612 | kcopyd_clients++; | |
14cc3e2b | 613 | mutex_unlock(&kcopyd_init_lock); |
1da177e4 LT |
614 | return 0; |
615 | } | |
616 | ||
617 | r = jobs_init(); | |
618 | if (r) { | |
14cc3e2b | 619 | mutex_unlock(&kcopyd_init_lock); |
1da177e4 LT |
620 | return r; |
621 | } | |
622 | ||
623 | _kcopyd_wq = create_singlethread_workqueue("kcopyd"); | |
624 | if (!_kcopyd_wq) { | |
625 | jobs_exit(); | |
14cc3e2b | 626 | mutex_unlock(&kcopyd_init_lock); |
1da177e4 LT |
627 | return -ENOMEM; |
628 | } | |
629 | ||
630 | kcopyd_clients++; | |
631 | INIT_WORK(&_kcopyd_work, do_work, NULL); | |
14cc3e2b | 632 | mutex_unlock(&kcopyd_init_lock); |
1da177e4 LT |
633 | return 0; |
634 | } | |
635 | ||
636 | static void kcopyd_exit(void) | |
637 | { | |
14cc3e2b | 638 | mutex_lock(&kcopyd_init_lock); |
1da177e4 LT |
639 | kcopyd_clients--; |
640 | if (!kcopyd_clients) { | |
641 | jobs_exit(); | |
642 | destroy_workqueue(_kcopyd_wq); | |
643 | _kcopyd_wq = NULL; | |
644 | } | |
14cc3e2b | 645 | mutex_unlock(&kcopyd_init_lock); |
1da177e4 LT |
646 | } |
647 | ||
648 | int kcopyd_client_create(unsigned int nr_pages, struct kcopyd_client **result) | |
649 | { | |
650 | int r = 0; | |
651 | struct kcopyd_client *kc; | |
652 | ||
653 | r = kcopyd_init(); | |
654 | if (r) | |
655 | return r; | |
656 | ||
657 | kc = kmalloc(sizeof(*kc), GFP_KERNEL); | |
658 | if (!kc) { | |
659 | kcopyd_exit(); | |
660 | return -ENOMEM; | |
661 | } | |
662 | ||
663 | spin_lock_init(&kc->lock); | |
664 | kc->pages = NULL; | |
665 | kc->nr_pages = kc->nr_free_pages = 0; | |
666 | r = client_alloc_pages(kc, nr_pages); | |
667 | if (r) { | |
668 | kfree(kc); | |
669 | kcopyd_exit(); | |
670 | return r; | |
671 | } | |
672 | ||
673 | r = dm_io_get(nr_pages); | |
674 | if (r) { | |
675 | client_free_pages(kc); | |
676 | kfree(kc); | |
677 | kcopyd_exit(); | |
678 | return r; | |
679 | } | |
680 | ||
138728dc AK |
681 | init_waitqueue_head(&kc->destroyq); |
682 | atomic_set(&kc->nr_jobs, 0); | |
683 | ||
1da177e4 LT |
684 | client_add(kc); |
685 | *result = kc; | |
686 | return 0; | |
687 | } | |
688 | ||
689 | void kcopyd_client_destroy(struct kcopyd_client *kc) | |
690 | { | |
138728dc AK |
691 | /* Wait for completion of all jobs submitted by this client. */ |
692 | wait_event(kc->destroyq, !atomic_read(&kc->nr_jobs)); | |
693 | ||
1da177e4 LT |
694 | dm_io_put(kc->nr_pages); |
695 | client_free_pages(kc); | |
696 | client_del(kc); | |
697 | kfree(kc); | |
698 | kcopyd_exit(); | |
699 | } | |
700 | ||
701 | EXPORT_SYMBOL(kcopyd_client_create); | |
702 | EXPORT_SYMBOL(kcopyd_client_destroy); | |
703 | EXPORT_SYMBOL(kcopyd_copy); |