Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * Copyright (C) 2002 Sistina Software (UK) Limited. | |
373a392b | 3 | * Copyright (C) 2006 Red Hat GmbH |
1da177e4 LT |
4 | * |
5 | * This file is released under the GPL. | |
6 | * | |
7 | * Kcopyd provides a simple interface for copying an area of one | |
8 | * block-device to one or more other block-devices, with an asynchronous | |
9 | * completion notification. | |
10 | */ | |
11 | ||
eb69aca5 | 12 | #include <linux/types.h> |
1da177e4 | 13 | #include <asm/atomic.h> |
1da177e4 | 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> |
586e80e6 | 25 | #include <linux/device-mapper.h> |
a765e20e | 26 | #include <linux/dm-kcopyd.h> |
1da177e4 | 27 | |
22a1ceb1 | 28 | #include "dm.h" |
1da177e4 | 29 | |
1da177e4 LT |
30 | /*----------------------------------------------------------------- |
31 | * Each kcopyd client has its own little pool of preallocated | |
32 | * pages for kcopyd io. | |
33 | *---------------------------------------------------------------*/ | |
eb69aca5 | 34 | struct dm_kcopyd_client { |
1da177e4 LT |
35 | spinlock_t lock; |
36 | struct page_list *pages; | |
37 | unsigned int nr_pages; | |
38 | unsigned int nr_free_pages; | |
138728dc | 39 | |
373a392b MB |
40 | struct dm_io_client *io_client; |
41 | ||
138728dc AK |
42 | wait_queue_head_t destroyq; |
43 | atomic_t nr_jobs; | |
8c0cbc2f | 44 | |
08d8757a MP |
45 | mempool_t *job_pool; |
46 | ||
8c0cbc2f MP |
47 | struct workqueue_struct *kcopyd_wq; |
48 | struct work_struct kcopyd_work; | |
49 | ||
50 | /* | |
51 | * We maintain three lists of jobs: | |
52 | * | |
53 | * i) jobs waiting for pages | |
54 | * ii) jobs that have pages, and are waiting for the io to be issued. | |
55 | * iii) jobs that have completed. | |
56 | * | |
57 | * All three of these are protected by job_lock. | |
58 | */ | |
59 | spinlock_t job_lock; | |
60 | struct list_head complete_jobs; | |
61 | struct list_head io_jobs; | |
62 | struct list_head pages_jobs; | |
1da177e4 LT |
63 | }; |
64 | ||
8c0cbc2f MP |
65 | static void wake(struct dm_kcopyd_client *kc) |
66 | { | |
67 | queue_work(kc->kcopyd_wq, &kc->kcopyd_work); | |
68 | } | |
69 | ||
1da177e4 LT |
70 | static struct page_list *alloc_pl(void) |
71 | { | |
72 | struct page_list *pl; | |
73 | ||
74 | pl = kmalloc(sizeof(*pl), GFP_KERNEL); | |
75 | if (!pl) | |
76 | return NULL; | |
77 | ||
78 | pl->page = alloc_page(GFP_KERNEL); | |
79 | if (!pl->page) { | |
80 | kfree(pl); | |
81 | return NULL; | |
82 | } | |
83 | ||
84 | return pl; | |
85 | } | |
86 | ||
87 | static void free_pl(struct page_list *pl) | |
88 | { | |
89 | __free_page(pl->page); | |
90 | kfree(pl); | |
91 | } | |
92 | ||
eb69aca5 | 93 | static int kcopyd_get_pages(struct dm_kcopyd_client *kc, |
1da177e4 LT |
94 | unsigned int nr, struct page_list **pages) |
95 | { | |
96 | struct page_list *pl; | |
97 | ||
98 | spin_lock(&kc->lock); | |
99 | if (kc->nr_free_pages < nr) { | |
100 | spin_unlock(&kc->lock); | |
101 | return -ENOMEM; | |
102 | } | |
103 | ||
104 | kc->nr_free_pages -= nr; | |
105 | for (*pages = pl = kc->pages; --nr; pl = pl->next) | |
106 | ; | |
107 | ||
108 | kc->pages = pl->next; | |
109 | pl->next = NULL; | |
110 | ||
111 | spin_unlock(&kc->lock); | |
112 | ||
113 | return 0; | |
114 | } | |
115 | ||
eb69aca5 | 116 | static void kcopyd_put_pages(struct dm_kcopyd_client *kc, struct page_list *pl) |
1da177e4 LT |
117 | { |
118 | struct page_list *cursor; | |
119 | ||
120 | spin_lock(&kc->lock); | |
121 | for (cursor = pl; cursor->next; cursor = cursor->next) | |
122 | kc->nr_free_pages++; | |
123 | ||
124 | kc->nr_free_pages++; | |
125 | cursor->next = kc->pages; | |
126 | kc->pages = pl; | |
127 | spin_unlock(&kc->lock); | |
128 | } | |
129 | ||
130 | /* | |
131 | * These three functions resize the page pool. | |
132 | */ | |
133 | static void drop_pages(struct page_list *pl) | |
134 | { | |
135 | struct page_list *next; | |
136 | ||
137 | while (pl) { | |
138 | next = pl->next; | |
139 | free_pl(pl); | |
140 | pl = next; | |
141 | } | |
142 | } | |
143 | ||
eb69aca5 | 144 | static int client_alloc_pages(struct dm_kcopyd_client *kc, unsigned int nr) |
1da177e4 LT |
145 | { |
146 | unsigned int i; | |
147 | struct page_list *pl = NULL, *next; | |
148 | ||
149 | for (i = 0; i < nr; i++) { | |
150 | next = alloc_pl(); | |
151 | if (!next) { | |
152 | if (pl) | |
153 | drop_pages(pl); | |
154 | return -ENOMEM; | |
155 | } | |
156 | next->next = pl; | |
157 | pl = next; | |
158 | } | |
159 | ||
160 | kcopyd_put_pages(kc, pl); | |
161 | kc->nr_pages += nr; | |
162 | return 0; | |
163 | } | |
164 | ||
eb69aca5 | 165 | static void client_free_pages(struct dm_kcopyd_client *kc) |
1da177e4 LT |
166 | { |
167 | BUG_ON(kc->nr_free_pages != kc->nr_pages); | |
168 | drop_pages(kc->pages); | |
169 | kc->pages = NULL; | |
170 | kc->nr_free_pages = kc->nr_pages = 0; | |
171 | } | |
172 | ||
173 | /*----------------------------------------------------------------- | |
174 | * kcopyd_jobs need to be allocated by the *clients* of kcopyd, | |
175 | * for this reason we use a mempool to prevent the client from | |
176 | * ever having to do io (which could cause a deadlock). | |
177 | *---------------------------------------------------------------*/ | |
178 | struct kcopyd_job { | |
eb69aca5 | 179 | struct dm_kcopyd_client *kc; |
1da177e4 LT |
180 | struct list_head list; |
181 | unsigned long flags; | |
182 | ||
183 | /* | |
184 | * Error state of the job. | |
185 | */ | |
186 | int read_err; | |
4cdc1d1f | 187 | unsigned long write_err; |
1da177e4 LT |
188 | |
189 | /* | |
190 | * Either READ or WRITE | |
191 | */ | |
192 | int rw; | |
22a1ceb1 | 193 | struct dm_io_region source; |
1da177e4 LT |
194 | |
195 | /* | |
196 | * The destinations for the transfer. | |
197 | */ | |
198 | unsigned int num_dests; | |
eb69aca5 | 199 | struct dm_io_region dests[DM_KCOPYD_MAX_REGIONS]; |
1da177e4 LT |
200 | |
201 | sector_t offset; | |
202 | unsigned int nr_pages; | |
203 | struct page_list *pages; | |
204 | ||
205 | /* | |
206 | * Set this to ensure you are notified when the job has | |
207 | * completed. 'context' is for callback to use. | |
208 | */ | |
eb69aca5 | 209 | dm_kcopyd_notify_fn fn; |
1da177e4 LT |
210 | void *context; |
211 | ||
212 | /* | |
213 | * These fields are only used if the job has been split | |
214 | * into more manageable parts. | |
215 | */ | |
def5b5b2 | 216 | struct mutex lock; |
1da177e4 LT |
217 | atomic_t sub_jobs; |
218 | sector_t progress; | |
219 | }; | |
220 | ||
221 | /* FIXME: this should scale with the number of pages */ | |
222 | #define MIN_JOBS 512 | |
223 | ||
e18b890b | 224 | static struct kmem_cache *_job_cache; |
1da177e4 | 225 | |
945fa4d2 | 226 | int __init dm_kcopyd_init(void) |
1da177e4 | 227 | { |
028867ac | 228 | _job_cache = KMEM_CACHE(kcopyd_job, 0); |
1da177e4 LT |
229 | if (!_job_cache) |
230 | return -ENOMEM; | |
231 | ||
1da177e4 LT |
232 | return 0; |
233 | } | |
234 | ||
945fa4d2 | 235 | void dm_kcopyd_exit(void) |
1da177e4 | 236 | { |
1da177e4 | 237 | kmem_cache_destroy(_job_cache); |
1da177e4 LT |
238 | _job_cache = NULL; |
239 | } | |
240 | ||
241 | /* | |
242 | * Functions to push and pop a job onto the head of a given job | |
243 | * list. | |
244 | */ | |
8c0cbc2f MP |
245 | static struct kcopyd_job *pop(struct list_head *jobs, |
246 | struct dm_kcopyd_client *kc) | |
1da177e4 LT |
247 | { |
248 | struct kcopyd_job *job = NULL; | |
249 | unsigned long flags; | |
250 | ||
8c0cbc2f | 251 | spin_lock_irqsave(&kc->job_lock, flags); |
1da177e4 LT |
252 | |
253 | if (!list_empty(jobs)) { | |
254 | job = list_entry(jobs->next, struct kcopyd_job, list); | |
255 | list_del(&job->list); | |
256 | } | |
8c0cbc2f | 257 | spin_unlock_irqrestore(&kc->job_lock, flags); |
1da177e4 LT |
258 | |
259 | return job; | |
260 | } | |
261 | ||
028867ac | 262 | static void push(struct list_head *jobs, struct kcopyd_job *job) |
1da177e4 LT |
263 | { |
264 | unsigned long flags; | |
8c0cbc2f | 265 | struct dm_kcopyd_client *kc = job->kc; |
1da177e4 | 266 | |
8c0cbc2f | 267 | spin_lock_irqsave(&kc->job_lock, flags); |
1da177e4 | 268 | list_add_tail(&job->list, jobs); |
8c0cbc2f | 269 | spin_unlock_irqrestore(&kc->job_lock, flags); |
1da177e4 LT |
270 | } |
271 | ||
b673c3a8 KI |
272 | |
273 | static void push_head(struct list_head *jobs, struct kcopyd_job *job) | |
274 | { | |
275 | unsigned long flags; | |
276 | struct dm_kcopyd_client *kc = job->kc; | |
277 | ||
278 | spin_lock_irqsave(&kc->job_lock, flags); | |
279 | list_add(&job->list, jobs); | |
280 | spin_unlock_irqrestore(&kc->job_lock, flags); | |
281 | } | |
282 | ||
1da177e4 LT |
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; | |
4cdc1d1f | 296 | unsigned long write_err = job->write_err; |
eb69aca5 HM |
297 | dm_kcopyd_notify_fn fn = job->fn; |
298 | struct dm_kcopyd_client *kc = job->kc; | |
1da177e4 | 299 | |
138728dc | 300 | kcopyd_put_pages(kc, job->pages); |
08d8757a | 301 | mempool_free(job, kc->job_pool); |
1da177e4 | 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; | |
8c0cbc2f | 313 | struct dm_kcopyd_client *kc = job->kc; |
1da177e4 LT |
314 | |
315 | if (error) { | |
316 | if (job->rw == WRITE) | |
ce503f59 | 317 | job->write_err |= error; |
1da177e4 LT |
318 | else |
319 | job->read_err = 1; | |
320 | ||
eb69aca5 | 321 | if (!test_bit(DM_KCOPYD_IGNORE_ERROR, &job->flags)) { |
8c0cbc2f MP |
322 | push(&kc->complete_jobs, job); |
323 | wake(kc); | |
1da177e4 LT |
324 | return; |
325 | } | |
326 | } | |
327 | ||
328 | if (job->rw == WRITE) | |
8c0cbc2f | 329 | push(&kc->complete_jobs, job); |
1da177e4 LT |
330 | |
331 | else { | |
332 | job->rw = WRITE; | |
8c0cbc2f | 333 | push(&kc->io_jobs, job); |
1da177e4 LT |
334 | } |
335 | ||
8c0cbc2f | 336 | wake(kc); |
1da177e4 LT |
337 | } |
338 | ||
339 | /* | |
340 | * Request io on as many buffer heads as we can currently get for | |
341 | * a particular job. | |
342 | */ | |
343 | static int run_io_job(struct kcopyd_job *job) | |
344 | { | |
345 | int r; | |
373a392b | 346 | struct dm_io_request io_req = { |
93dbb393 | 347 | .bi_rw = job->rw | (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG), |
373a392b MB |
348 | .mem.type = DM_IO_PAGE_LIST, |
349 | .mem.ptr.pl = job->pages, | |
350 | .mem.offset = job->offset, | |
351 | .notify.fn = complete_io, | |
352 | .notify.context = job, | |
353 | .client = job->kc->io_client, | |
354 | }; | |
1da177e4 LT |
355 | |
356 | if (job->rw == READ) | |
373a392b | 357 | r = dm_io(&io_req, 1, &job->source, NULL); |
1da177e4 | 358 | else |
373a392b | 359 | r = dm_io(&io_req, job->num_dests, job->dests, NULL); |
1da177e4 LT |
360 | |
361 | return r; | |
362 | } | |
363 | ||
364 | static int run_pages_job(struct kcopyd_job *job) | |
365 | { | |
366 | int r; | |
367 | ||
368 | job->nr_pages = dm_div_up(job->dests[0].count + job->offset, | |
369 | PAGE_SIZE >> 9); | |
370 | r = kcopyd_get_pages(job->kc, job->nr_pages, &job->pages); | |
371 | if (!r) { | |
372 | /* this job is ready for io */ | |
8c0cbc2f | 373 | push(&job->kc->io_jobs, job); |
1da177e4 LT |
374 | return 0; |
375 | } | |
376 | ||
377 | if (r == -ENOMEM) | |
378 | /* can't complete now */ | |
379 | return 1; | |
380 | ||
381 | return r; | |
382 | } | |
383 | ||
384 | /* | |
385 | * Run through a list for as long as possible. Returns the count | |
386 | * of successful jobs. | |
387 | */ | |
8c0cbc2f MP |
388 | static int process_jobs(struct list_head *jobs, struct dm_kcopyd_client *kc, |
389 | int (*fn) (struct kcopyd_job *)) | |
1da177e4 LT |
390 | { |
391 | struct kcopyd_job *job; | |
392 | int r, count = 0; | |
393 | ||
8c0cbc2f | 394 | while ((job = pop(jobs, kc))) { |
1da177e4 LT |
395 | |
396 | r = fn(job); | |
397 | ||
398 | if (r < 0) { | |
399 | /* error this rogue job */ | |
400 | if (job->rw == WRITE) | |
4cdc1d1f | 401 | job->write_err = (unsigned long) -1L; |
1da177e4 LT |
402 | else |
403 | job->read_err = 1; | |
8c0cbc2f | 404 | push(&kc->complete_jobs, job); |
1da177e4 LT |
405 | break; |
406 | } | |
407 | ||
408 | if (r > 0) { | |
409 | /* | |
410 | * We couldn't service this job ATM, so | |
411 | * push this job back onto the list. | |
412 | */ | |
b673c3a8 | 413 | push_head(jobs, job); |
1da177e4 LT |
414 | break; |
415 | } | |
416 | ||
417 | count++; | |
418 | } | |
419 | ||
420 | return count; | |
421 | } | |
422 | ||
423 | /* | |
424 | * kcopyd does this every time it's woken up. | |
425 | */ | |
8c0cbc2f | 426 | static void do_work(struct work_struct *work) |
1da177e4 | 427 | { |
8c0cbc2f MP |
428 | struct dm_kcopyd_client *kc = container_of(work, |
429 | struct dm_kcopyd_client, kcopyd_work); | |
430 | ||
1da177e4 LT |
431 | /* |
432 | * The order that these are called is *very* important. | |
433 | * complete jobs can free some pages for pages jobs. | |
434 | * Pages jobs when successful will jump onto the io jobs | |
435 | * list. io jobs call wake when they complete and it all | |
436 | * starts again. | |
437 | */ | |
8c0cbc2f MP |
438 | process_jobs(&kc->complete_jobs, kc, run_complete_job); |
439 | process_jobs(&kc->pages_jobs, kc, run_pages_job); | |
440 | process_jobs(&kc->io_jobs, kc, run_io_job); | |
1da177e4 LT |
441 | } |
442 | ||
443 | /* | |
444 | * If we are copying a small region we just dispatch a single job | |
445 | * to do the copy, otherwise the io has to be split up into many | |
446 | * jobs. | |
447 | */ | |
448 | static void dispatch_job(struct kcopyd_job *job) | |
449 | { | |
8c0cbc2f MP |
450 | struct dm_kcopyd_client *kc = job->kc; |
451 | atomic_inc(&kc->nr_jobs); | |
452 | push(&kc->pages_jobs, job); | |
453 | wake(kc); | |
1da177e4 LT |
454 | } |
455 | ||
456 | #define SUB_JOB_SIZE 128 | |
4cdc1d1f AK |
457 | static void segment_complete(int read_err, unsigned long write_err, |
458 | void *context) | |
1da177e4 LT |
459 | { |
460 | /* FIXME: tidy this function */ | |
461 | sector_t progress = 0; | |
462 | sector_t count = 0; | |
463 | struct kcopyd_job *job = (struct kcopyd_job *) context; | |
464 | ||
def5b5b2 | 465 | mutex_lock(&job->lock); |
1da177e4 LT |
466 | |
467 | /* update the error */ | |
468 | if (read_err) | |
469 | job->read_err = 1; | |
470 | ||
471 | if (write_err) | |
ce503f59 | 472 | job->write_err |= write_err; |
1da177e4 LT |
473 | |
474 | /* | |
475 | * Only dispatch more work if there hasn't been an error. | |
476 | */ | |
477 | if ((!job->read_err && !job->write_err) || | |
eb69aca5 | 478 | test_bit(DM_KCOPYD_IGNORE_ERROR, &job->flags)) { |
1da177e4 LT |
479 | /* get the next chunk of work */ |
480 | progress = job->progress; | |
481 | count = job->source.count - progress; | |
482 | if (count) { | |
483 | if (count > SUB_JOB_SIZE) | |
484 | count = SUB_JOB_SIZE; | |
485 | ||
486 | job->progress += count; | |
487 | } | |
488 | } | |
def5b5b2 | 489 | mutex_unlock(&job->lock); |
1da177e4 LT |
490 | |
491 | if (count) { | |
492 | int i; | |
08d8757a MP |
493 | struct kcopyd_job *sub_job = mempool_alloc(job->kc->job_pool, |
494 | GFP_NOIO); | |
1da177e4 LT |
495 | |
496 | *sub_job = *job; | |
497 | sub_job->source.sector += progress; | |
498 | sub_job->source.count = count; | |
499 | ||
500 | for (i = 0; i < job->num_dests; i++) { | |
501 | sub_job->dests[i].sector += progress; | |
502 | sub_job->dests[i].count = count; | |
503 | } | |
504 | ||
505 | sub_job->fn = segment_complete; | |
506 | sub_job->context = job; | |
507 | dispatch_job(sub_job); | |
508 | ||
509 | } else if (atomic_dec_and_test(&job->sub_jobs)) { | |
510 | ||
511 | /* | |
512 | * To avoid a race we must keep the job around | |
513 | * until after the notify function has completed. | |
514 | * Otherwise the client may try and stop the job | |
515 | * after we've completed. | |
516 | */ | |
517 | job->fn(read_err, write_err, job->context); | |
08d8757a | 518 | mempool_free(job, job->kc->job_pool); |
1da177e4 LT |
519 | } |
520 | } | |
521 | ||
522 | /* | |
523 | * Create some little jobs that will do the move between | |
524 | * them. | |
525 | */ | |
526 | #define SPLIT_COUNT 8 | |
527 | static void split_job(struct kcopyd_job *job) | |
528 | { | |
529 | int i; | |
530 | ||
531 | atomic_set(&job->sub_jobs, SPLIT_COUNT); | |
532 | for (i = 0; i < SPLIT_COUNT; i++) | |
533 | segment_complete(0, 0u, job); | |
534 | } | |
535 | ||
eb69aca5 HM |
536 | int dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from, |
537 | unsigned int num_dests, struct dm_io_region *dests, | |
538 | unsigned int flags, dm_kcopyd_notify_fn fn, void *context) | |
1da177e4 LT |
539 | { |
540 | struct kcopyd_job *job; | |
541 | ||
542 | /* | |
543 | * Allocate a new job. | |
544 | */ | |
08d8757a | 545 | job = mempool_alloc(kc->job_pool, GFP_NOIO); |
1da177e4 LT |
546 | |
547 | /* | |
548 | * set up for the read. | |
549 | */ | |
550 | job->kc = kc; | |
551 | job->flags = flags; | |
552 | job->read_err = 0; | |
553 | job->write_err = 0; | |
554 | job->rw = READ; | |
555 | ||
556 | job->source = *from; | |
557 | ||
558 | job->num_dests = num_dests; | |
559 | memcpy(&job->dests, dests, sizeof(*dests) * num_dests); | |
560 | ||
561 | job->offset = 0; | |
562 | job->nr_pages = 0; | |
563 | job->pages = NULL; | |
564 | ||
565 | job->fn = fn; | |
566 | job->context = context; | |
567 | ||
568 | if (job->source.count < SUB_JOB_SIZE) | |
569 | dispatch_job(job); | |
570 | ||
571 | else { | |
def5b5b2 | 572 | mutex_init(&job->lock); |
1da177e4 LT |
573 | job->progress = 0; |
574 | split_job(job); | |
575 | } | |
576 | ||
577 | return 0; | |
578 | } | |
eb69aca5 | 579 | EXPORT_SYMBOL(dm_kcopyd_copy); |
1da177e4 LT |
580 | |
581 | /* | |
582 | * Cancels a kcopyd job, eg. someone might be deactivating a | |
583 | * mirror. | |
584 | */ | |
0b56306e | 585 | #if 0 |
1da177e4 LT |
586 | int kcopyd_cancel(struct kcopyd_job *job, int block) |
587 | { | |
588 | /* FIXME: finish */ | |
589 | return -1; | |
590 | } | |
0b56306e | 591 | #endif /* 0 */ |
1da177e4 LT |
592 | |
593 | /*----------------------------------------------------------------- | |
945fa4d2 | 594 | * Client setup |
1da177e4 | 595 | *---------------------------------------------------------------*/ |
eb69aca5 HM |
596 | int dm_kcopyd_client_create(unsigned int nr_pages, |
597 | struct dm_kcopyd_client **result) | |
1da177e4 | 598 | { |
945fa4d2 | 599 | int r = -ENOMEM; |
eb69aca5 | 600 | struct dm_kcopyd_client *kc; |
1da177e4 | 601 | |
1da177e4 | 602 | kc = kmalloc(sizeof(*kc), GFP_KERNEL); |
945fa4d2 MP |
603 | if (!kc) |
604 | return -ENOMEM; | |
1da177e4 LT |
605 | |
606 | spin_lock_init(&kc->lock); | |
8c0cbc2f MP |
607 | spin_lock_init(&kc->job_lock); |
608 | INIT_LIST_HEAD(&kc->complete_jobs); | |
609 | INIT_LIST_HEAD(&kc->io_jobs); | |
610 | INIT_LIST_HEAD(&kc->pages_jobs); | |
611 | ||
08d8757a | 612 | kc->job_pool = mempool_create_slab_pool(MIN_JOBS, _job_cache); |
945fa4d2 MP |
613 | if (!kc->job_pool) |
614 | goto bad_slab; | |
08d8757a | 615 | |
8c0cbc2f MP |
616 | INIT_WORK(&kc->kcopyd_work, do_work); |
617 | kc->kcopyd_wq = create_singlethread_workqueue("kcopyd"); | |
945fa4d2 MP |
618 | if (!kc->kcopyd_wq) |
619 | goto bad_workqueue; | |
8c0cbc2f | 620 | |
1da177e4 LT |
621 | kc->pages = NULL; |
622 | kc->nr_pages = kc->nr_free_pages = 0; | |
623 | r = client_alloc_pages(kc, nr_pages); | |
945fa4d2 MP |
624 | if (r) |
625 | goto bad_client_pages; | |
1da177e4 | 626 | |
373a392b MB |
627 | kc->io_client = dm_io_client_create(nr_pages); |
628 | if (IS_ERR(kc->io_client)) { | |
629 | r = PTR_ERR(kc->io_client); | |
945fa4d2 | 630 | goto bad_io_client; |
1da177e4 LT |
631 | } |
632 | ||
138728dc AK |
633 | init_waitqueue_head(&kc->destroyq); |
634 | atomic_set(&kc->nr_jobs, 0); | |
635 | ||
1da177e4 LT |
636 | *result = kc; |
637 | return 0; | |
945fa4d2 MP |
638 | |
639 | bad_io_client: | |
640 | client_free_pages(kc); | |
641 | bad_client_pages: | |
642 | destroy_workqueue(kc->kcopyd_wq); | |
643 | bad_workqueue: | |
644 | mempool_destroy(kc->job_pool); | |
645 | bad_slab: | |
646 | kfree(kc); | |
647 | ||
648 | return r; | |
1da177e4 | 649 | } |
eb69aca5 | 650 | EXPORT_SYMBOL(dm_kcopyd_client_create); |
1da177e4 | 651 | |
eb69aca5 | 652 | void dm_kcopyd_client_destroy(struct dm_kcopyd_client *kc) |
1da177e4 | 653 | { |
138728dc AK |
654 | /* Wait for completion of all jobs submitted by this client. */ |
655 | wait_event(kc->destroyq, !atomic_read(&kc->nr_jobs)); | |
656 | ||
8c0cbc2f MP |
657 | BUG_ON(!list_empty(&kc->complete_jobs)); |
658 | BUG_ON(!list_empty(&kc->io_jobs)); | |
659 | BUG_ON(!list_empty(&kc->pages_jobs)); | |
660 | destroy_workqueue(kc->kcopyd_wq); | |
373a392b | 661 | dm_io_client_destroy(kc->io_client); |
1da177e4 | 662 | client_free_pages(kc); |
08d8757a | 663 | mempool_destroy(kc->job_pool); |
1da177e4 | 664 | kfree(kc); |
1da177e4 | 665 | } |
eb69aca5 | 666 | EXPORT_SYMBOL(dm_kcopyd_client_destroy); |