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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 | |
c6ea41fb MP |
30 | #define SUB_JOB_SIZE 128 |
31 | #define SPLIT_COUNT 8 | |
32 | #define MIN_JOBS 8 | |
33 | ||
1da177e4 LT |
34 | /*----------------------------------------------------------------- |
35 | * Each kcopyd client has its own little pool of preallocated | |
36 | * pages for kcopyd io. | |
37 | *---------------------------------------------------------------*/ | |
eb69aca5 | 38 | struct dm_kcopyd_client { |
1da177e4 LT |
39 | struct page_list *pages; |
40 | unsigned int nr_pages; | |
41 | unsigned int nr_free_pages; | |
138728dc | 42 | |
373a392b MB |
43 | struct dm_io_client *io_client; |
44 | ||
138728dc AK |
45 | wait_queue_head_t destroyq; |
46 | atomic_t nr_jobs; | |
8c0cbc2f | 47 | |
08d8757a MP |
48 | mempool_t *job_pool; |
49 | ||
8c0cbc2f MP |
50 | struct workqueue_struct *kcopyd_wq; |
51 | struct work_struct kcopyd_work; | |
52 | ||
53 | /* | |
54 | * We maintain three lists of jobs: | |
55 | * | |
56 | * i) jobs waiting for pages | |
57 | * ii) jobs that have pages, and are waiting for the io to be issued. | |
58 | * iii) jobs that have completed. | |
59 | * | |
60 | * All three of these are protected by job_lock. | |
61 | */ | |
62 | spinlock_t job_lock; | |
63 | struct list_head complete_jobs; | |
64 | struct list_head io_jobs; | |
65 | struct list_head pages_jobs; | |
1da177e4 LT |
66 | }; |
67 | ||
8c0cbc2f MP |
68 | static void wake(struct dm_kcopyd_client *kc) |
69 | { | |
70 | queue_work(kc->kcopyd_wq, &kc->kcopyd_work); | |
71 | } | |
72 | ||
1da177e4 LT |
73 | static struct page_list *alloc_pl(void) |
74 | { | |
75 | struct page_list *pl; | |
76 | ||
77 | pl = kmalloc(sizeof(*pl), GFP_KERNEL); | |
78 | if (!pl) | |
79 | return NULL; | |
80 | ||
81 | pl->page = alloc_page(GFP_KERNEL); | |
82 | if (!pl->page) { | |
83 | kfree(pl); | |
84 | return NULL; | |
85 | } | |
86 | ||
87 | return pl; | |
88 | } | |
89 | ||
90 | static void free_pl(struct page_list *pl) | |
91 | { | |
92 | __free_page(pl->page); | |
93 | kfree(pl); | |
94 | } | |
95 | ||
eb69aca5 | 96 | static int kcopyd_get_pages(struct dm_kcopyd_client *kc, |
1da177e4 LT |
97 | unsigned int nr, struct page_list **pages) |
98 | { | |
99 | struct page_list *pl; | |
100 | ||
4cc1b4cf | 101 | if (kc->nr_free_pages < nr) |
1da177e4 | 102 | return -ENOMEM; |
1da177e4 LT |
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 | ||
1da177e4 LT |
111 | return 0; |
112 | } | |
113 | ||
eb69aca5 | 114 | static void kcopyd_put_pages(struct dm_kcopyd_client *kc, struct page_list *pl) |
1da177e4 LT |
115 | { |
116 | struct page_list *cursor; | |
117 | ||
1da177e4 LT |
118 | for (cursor = pl; cursor->next; cursor = cursor->next) |
119 | kc->nr_free_pages++; | |
120 | ||
121 | kc->nr_free_pages++; | |
122 | cursor->next = kc->pages; | |
123 | kc->pages = pl; | |
1da177e4 LT |
124 | } |
125 | ||
126 | /* | |
127 | * These three functions resize the page pool. | |
128 | */ | |
129 | static void drop_pages(struct page_list *pl) | |
130 | { | |
131 | struct page_list *next; | |
132 | ||
133 | while (pl) { | |
134 | next = pl->next; | |
135 | free_pl(pl); | |
136 | pl = next; | |
137 | } | |
138 | } | |
139 | ||
eb69aca5 | 140 | static int client_alloc_pages(struct dm_kcopyd_client *kc, unsigned int nr) |
1da177e4 LT |
141 | { |
142 | unsigned int i; | |
143 | struct page_list *pl = NULL, *next; | |
144 | ||
145 | for (i = 0; i < nr; i++) { | |
146 | next = alloc_pl(); | |
147 | if (!next) { | |
148 | if (pl) | |
149 | drop_pages(pl); | |
150 | return -ENOMEM; | |
151 | } | |
152 | next->next = pl; | |
153 | pl = next; | |
154 | } | |
155 | ||
156 | kcopyd_put_pages(kc, pl); | |
157 | kc->nr_pages += nr; | |
158 | return 0; | |
159 | } | |
160 | ||
eb69aca5 | 161 | static void client_free_pages(struct dm_kcopyd_client *kc) |
1da177e4 LT |
162 | { |
163 | BUG_ON(kc->nr_free_pages != kc->nr_pages); | |
164 | drop_pages(kc->pages); | |
165 | kc->pages = NULL; | |
166 | kc->nr_free_pages = kc->nr_pages = 0; | |
167 | } | |
168 | ||
169 | /*----------------------------------------------------------------- | |
170 | * kcopyd_jobs need to be allocated by the *clients* of kcopyd, | |
171 | * for this reason we use a mempool to prevent the client from | |
172 | * ever having to do io (which could cause a deadlock). | |
173 | *---------------------------------------------------------------*/ | |
174 | struct kcopyd_job { | |
eb69aca5 | 175 | struct dm_kcopyd_client *kc; |
1da177e4 LT |
176 | struct list_head list; |
177 | unsigned long flags; | |
178 | ||
179 | /* | |
180 | * Error state of the job. | |
181 | */ | |
182 | int read_err; | |
4cdc1d1f | 183 | unsigned long write_err; |
1da177e4 LT |
184 | |
185 | /* | |
186 | * Either READ or WRITE | |
187 | */ | |
188 | int rw; | |
22a1ceb1 | 189 | struct dm_io_region source; |
1da177e4 LT |
190 | |
191 | /* | |
192 | * The destinations for the transfer. | |
193 | */ | |
194 | unsigned int num_dests; | |
eb69aca5 | 195 | struct dm_io_region dests[DM_KCOPYD_MAX_REGIONS]; |
1da177e4 LT |
196 | |
197 | sector_t offset; | |
198 | unsigned int nr_pages; | |
199 | struct page_list *pages; | |
200 | ||
201 | /* | |
202 | * Set this to ensure you are notified when the job has | |
203 | * completed. 'context' is for callback to use. | |
204 | */ | |
eb69aca5 | 205 | dm_kcopyd_notify_fn fn; |
1da177e4 LT |
206 | void *context; |
207 | ||
208 | /* | |
209 | * These fields are only used if the job has been split | |
210 | * into more manageable parts. | |
211 | */ | |
def5b5b2 | 212 | struct mutex lock; |
1da177e4 LT |
213 | atomic_t sub_jobs; |
214 | sector_t progress; | |
1da177e4 | 215 | |
c6ea41fb MP |
216 | struct kcopyd_job *master_job; |
217 | }; | |
1da177e4 | 218 | |
e18b890b | 219 | static struct kmem_cache *_job_cache; |
1da177e4 | 220 | |
945fa4d2 | 221 | int __init dm_kcopyd_init(void) |
1da177e4 | 222 | { |
c6ea41fb MP |
223 | _job_cache = kmem_cache_create("kcopyd_job", |
224 | sizeof(struct kcopyd_job) * (SPLIT_COUNT + 1), | |
225 | __alignof__(struct kcopyd_job), 0, NULL); | |
1da177e4 LT |
226 | if (!_job_cache) |
227 | return -ENOMEM; | |
228 | ||
1da177e4 LT |
229 | return 0; |
230 | } | |
231 | ||
945fa4d2 | 232 | void dm_kcopyd_exit(void) |
1da177e4 | 233 | { |
1da177e4 | 234 | kmem_cache_destroy(_job_cache); |
1da177e4 LT |
235 | _job_cache = NULL; |
236 | } | |
237 | ||
238 | /* | |
239 | * Functions to push and pop a job onto the head of a given job | |
240 | * list. | |
241 | */ | |
8c0cbc2f MP |
242 | static struct kcopyd_job *pop(struct list_head *jobs, |
243 | struct dm_kcopyd_client *kc) | |
1da177e4 LT |
244 | { |
245 | struct kcopyd_job *job = NULL; | |
246 | unsigned long flags; | |
247 | ||
8c0cbc2f | 248 | spin_lock_irqsave(&kc->job_lock, flags); |
1da177e4 LT |
249 | |
250 | if (!list_empty(jobs)) { | |
251 | job = list_entry(jobs->next, struct kcopyd_job, list); | |
252 | list_del(&job->list); | |
253 | } | |
8c0cbc2f | 254 | spin_unlock_irqrestore(&kc->job_lock, flags); |
1da177e4 LT |
255 | |
256 | return job; | |
257 | } | |
258 | ||
028867ac | 259 | static void push(struct list_head *jobs, struct kcopyd_job *job) |
1da177e4 LT |
260 | { |
261 | unsigned long flags; | |
8c0cbc2f | 262 | struct dm_kcopyd_client *kc = job->kc; |
1da177e4 | 263 | |
8c0cbc2f | 264 | spin_lock_irqsave(&kc->job_lock, flags); |
1da177e4 | 265 | list_add_tail(&job->list, jobs); |
8c0cbc2f | 266 | spin_unlock_irqrestore(&kc->job_lock, flags); |
1da177e4 LT |
267 | } |
268 | ||
b673c3a8 KI |
269 | |
270 | static void push_head(struct list_head *jobs, struct kcopyd_job *job) | |
271 | { | |
272 | unsigned long flags; | |
273 | struct dm_kcopyd_client *kc = job->kc; | |
274 | ||
275 | spin_lock_irqsave(&kc->job_lock, flags); | |
276 | list_add(&job->list, jobs); | |
277 | spin_unlock_irqrestore(&kc->job_lock, flags); | |
278 | } | |
279 | ||
1da177e4 LT |
280 | /* |
281 | * These three functions process 1 item from the corresponding | |
282 | * job list. | |
283 | * | |
284 | * They return: | |
285 | * < 0: error | |
286 | * 0: success | |
287 | * > 0: can't process yet. | |
288 | */ | |
289 | static int run_complete_job(struct kcopyd_job *job) | |
290 | { | |
291 | void *context = job->context; | |
292 | int read_err = job->read_err; | |
4cdc1d1f | 293 | unsigned long write_err = job->write_err; |
eb69aca5 HM |
294 | dm_kcopyd_notify_fn fn = job->fn; |
295 | struct dm_kcopyd_client *kc = job->kc; | |
1da177e4 | 296 | |
73830857 MP |
297 | if (job->pages) |
298 | kcopyd_put_pages(kc, job->pages); | |
c6ea41fb MP |
299 | /* |
300 | * If this is the master job, the sub jobs have already | |
301 | * completed so we can free everything. | |
302 | */ | |
303 | if (job->master_job == job) | |
304 | mempool_free(job, kc->job_pool); | |
1da177e4 | 305 | fn(read_err, write_err, context); |
138728dc AK |
306 | |
307 | if (atomic_dec_and_test(&kc->nr_jobs)) | |
308 | wake_up(&kc->destroyq); | |
309 | ||
1da177e4 LT |
310 | return 0; |
311 | } | |
312 | ||
313 | static void complete_io(unsigned long error, void *context) | |
314 | { | |
315 | struct kcopyd_job *job = (struct kcopyd_job *) context; | |
8c0cbc2f | 316 | struct dm_kcopyd_client *kc = job->kc; |
1da177e4 LT |
317 | |
318 | if (error) { | |
319 | if (job->rw == WRITE) | |
ce503f59 | 320 | job->write_err |= error; |
1da177e4 LT |
321 | else |
322 | job->read_err = 1; | |
323 | ||
eb69aca5 | 324 | if (!test_bit(DM_KCOPYD_IGNORE_ERROR, &job->flags)) { |
8c0cbc2f MP |
325 | push(&kc->complete_jobs, job); |
326 | wake(kc); | |
1da177e4 LT |
327 | return; |
328 | } | |
329 | } | |
330 | ||
331 | if (job->rw == WRITE) | |
8c0cbc2f | 332 | push(&kc->complete_jobs, job); |
1da177e4 LT |
333 | |
334 | else { | |
335 | job->rw = WRITE; | |
8c0cbc2f | 336 | push(&kc->io_jobs, job); |
1da177e4 LT |
337 | } |
338 | ||
8c0cbc2f | 339 | wake(kc); |
1da177e4 LT |
340 | } |
341 | ||
342 | /* | |
343 | * Request io on as many buffer heads as we can currently get for | |
344 | * a particular job. | |
345 | */ | |
346 | static int run_io_job(struct kcopyd_job *job) | |
347 | { | |
348 | int r; | |
373a392b | 349 | struct dm_io_request io_req = { |
8d35d3e3 | 350 | .bi_rw = job->rw, |
373a392b MB |
351 | .mem.type = DM_IO_PAGE_LIST, |
352 | .mem.ptr.pl = job->pages, | |
353 | .mem.offset = job->offset, | |
354 | .notify.fn = complete_io, | |
355 | .notify.context = job, | |
356 | .client = job->kc->io_client, | |
357 | }; | |
1da177e4 | 358 | |
7eaceacc | 359 | if (job->rw == READ) |
373a392b | 360 | r = dm_io(&io_req, 1, &job->source, NULL); |
721a9602 | 361 | else |
373a392b | 362 | r = dm_io(&io_req, job->num_dests, job->dests, NULL); |
1da177e4 LT |
363 | |
364 | return r; | |
365 | } | |
366 | ||
367 | static int run_pages_job(struct kcopyd_job *job) | |
368 | { | |
369 | int r; | |
370 | ||
371 | job->nr_pages = dm_div_up(job->dests[0].count + job->offset, | |
372 | PAGE_SIZE >> 9); | |
373 | r = kcopyd_get_pages(job->kc, job->nr_pages, &job->pages); | |
374 | if (!r) { | |
375 | /* this job is ready for io */ | |
8c0cbc2f | 376 | push(&job->kc->io_jobs, job); |
1da177e4 LT |
377 | return 0; |
378 | } | |
379 | ||
380 | if (r == -ENOMEM) | |
381 | /* can't complete now */ | |
382 | return 1; | |
383 | ||
384 | return r; | |
385 | } | |
386 | ||
387 | /* | |
388 | * Run through a list for as long as possible. Returns the count | |
389 | * of successful jobs. | |
390 | */ | |
8c0cbc2f MP |
391 | static int process_jobs(struct list_head *jobs, struct dm_kcopyd_client *kc, |
392 | int (*fn) (struct kcopyd_job *)) | |
1da177e4 LT |
393 | { |
394 | struct kcopyd_job *job; | |
395 | int r, count = 0; | |
396 | ||
8c0cbc2f | 397 | while ((job = pop(jobs, kc))) { |
1da177e4 LT |
398 | |
399 | r = fn(job); | |
400 | ||
401 | if (r < 0) { | |
402 | /* error this rogue job */ | |
403 | if (job->rw == WRITE) | |
4cdc1d1f | 404 | job->write_err = (unsigned long) -1L; |
1da177e4 LT |
405 | else |
406 | job->read_err = 1; | |
8c0cbc2f | 407 | push(&kc->complete_jobs, job); |
1da177e4 LT |
408 | break; |
409 | } | |
410 | ||
411 | if (r > 0) { | |
412 | /* | |
413 | * We couldn't service this job ATM, so | |
414 | * push this job back onto the list. | |
415 | */ | |
b673c3a8 | 416 | push_head(jobs, job); |
1da177e4 LT |
417 | break; |
418 | } | |
419 | ||
420 | count++; | |
421 | } | |
422 | ||
423 | return count; | |
424 | } | |
425 | ||
426 | /* | |
427 | * kcopyd does this every time it's woken up. | |
428 | */ | |
8c0cbc2f | 429 | static void do_work(struct work_struct *work) |
1da177e4 | 430 | { |
8c0cbc2f MP |
431 | struct dm_kcopyd_client *kc = container_of(work, |
432 | struct dm_kcopyd_client, kcopyd_work); | |
7eaceacc | 433 | struct blk_plug plug; |
8c0cbc2f | 434 | |
1da177e4 LT |
435 | /* |
436 | * The order that these are called is *very* important. | |
437 | * complete jobs can free some pages for pages jobs. | |
438 | * Pages jobs when successful will jump onto the io jobs | |
439 | * list. io jobs call wake when they complete and it all | |
440 | * starts again. | |
441 | */ | |
7eaceacc | 442 | blk_start_plug(&plug); |
8c0cbc2f MP |
443 | process_jobs(&kc->complete_jobs, kc, run_complete_job); |
444 | process_jobs(&kc->pages_jobs, kc, run_pages_job); | |
445 | process_jobs(&kc->io_jobs, kc, run_io_job); | |
7eaceacc | 446 | blk_finish_plug(&plug); |
1da177e4 LT |
447 | } |
448 | ||
449 | /* | |
450 | * If we are copying a small region we just dispatch a single job | |
451 | * to do the copy, otherwise the io has to be split up into many | |
452 | * jobs. | |
453 | */ | |
454 | static void dispatch_job(struct kcopyd_job *job) | |
455 | { | |
8c0cbc2f MP |
456 | struct dm_kcopyd_client *kc = job->kc; |
457 | atomic_inc(&kc->nr_jobs); | |
9ca170a3 MP |
458 | if (unlikely(!job->source.count)) |
459 | push(&kc->complete_jobs, job); | |
460 | else | |
461 | push(&kc->pages_jobs, job); | |
8c0cbc2f | 462 | wake(kc); |
1da177e4 LT |
463 | } |
464 | ||
4cdc1d1f AK |
465 | static void segment_complete(int read_err, unsigned long write_err, |
466 | void *context) | |
1da177e4 LT |
467 | { |
468 | /* FIXME: tidy this function */ | |
469 | sector_t progress = 0; | |
470 | sector_t count = 0; | |
c6ea41fb MP |
471 | struct kcopyd_job *sub_job = (struct kcopyd_job *) context; |
472 | struct kcopyd_job *job = sub_job->master_job; | |
73830857 | 473 | struct dm_kcopyd_client *kc = job->kc; |
1da177e4 | 474 | |
def5b5b2 | 475 | mutex_lock(&job->lock); |
1da177e4 LT |
476 | |
477 | /* update the error */ | |
478 | if (read_err) | |
479 | job->read_err = 1; | |
480 | ||
481 | if (write_err) | |
ce503f59 | 482 | job->write_err |= write_err; |
1da177e4 LT |
483 | |
484 | /* | |
485 | * Only dispatch more work if there hasn't been an error. | |
486 | */ | |
487 | if ((!job->read_err && !job->write_err) || | |
eb69aca5 | 488 | test_bit(DM_KCOPYD_IGNORE_ERROR, &job->flags)) { |
1da177e4 LT |
489 | /* get the next chunk of work */ |
490 | progress = job->progress; | |
491 | count = job->source.count - progress; | |
492 | if (count) { | |
493 | if (count > SUB_JOB_SIZE) | |
494 | count = SUB_JOB_SIZE; | |
495 | ||
496 | job->progress += count; | |
497 | } | |
498 | } | |
def5b5b2 | 499 | mutex_unlock(&job->lock); |
1da177e4 LT |
500 | |
501 | if (count) { | |
502 | int i; | |
1da177e4 LT |
503 | |
504 | *sub_job = *job; | |
505 | sub_job->source.sector += progress; | |
506 | sub_job->source.count = count; | |
507 | ||
508 | for (i = 0; i < job->num_dests; i++) { | |
509 | sub_job->dests[i].sector += progress; | |
510 | sub_job->dests[i].count = count; | |
511 | } | |
512 | ||
513 | sub_job->fn = segment_complete; | |
c6ea41fb | 514 | sub_job->context = sub_job; |
1da177e4 LT |
515 | dispatch_job(sub_job); |
516 | ||
517 | } else if (atomic_dec_and_test(&job->sub_jobs)) { | |
518 | ||
519 | /* | |
340cd444 MP |
520 | * Queue the completion callback to the kcopyd thread. |
521 | * | |
522 | * Some callers assume that all the completions are called | |
523 | * from a single thread and don't race with each other. | |
524 | * | |
525 | * We must not call the callback directly here because this | |
526 | * code may not be executing in the thread. | |
1da177e4 | 527 | */ |
340cd444 MP |
528 | push(&kc->complete_jobs, job); |
529 | wake(kc); | |
1da177e4 LT |
530 | } |
531 | } | |
532 | ||
533 | /* | |
c6ea41fb | 534 | * Create some sub jobs to share the work between them. |
1da177e4 | 535 | */ |
c6ea41fb | 536 | static void split_job(struct kcopyd_job *master_job) |
1da177e4 LT |
537 | { |
538 | int i; | |
539 | ||
c6ea41fb | 540 | atomic_inc(&master_job->kc->nr_jobs); |
340cd444 | 541 | |
c6ea41fb MP |
542 | atomic_set(&master_job->sub_jobs, SPLIT_COUNT); |
543 | for (i = 0; i < SPLIT_COUNT; i++) { | |
544 | master_job[i + 1].master_job = master_job; | |
545 | segment_complete(0, 0u, &master_job[i + 1]); | |
546 | } | |
1da177e4 LT |
547 | } |
548 | ||
eb69aca5 HM |
549 | int dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from, |
550 | unsigned int num_dests, struct dm_io_region *dests, | |
551 | unsigned int flags, dm_kcopyd_notify_fn fn, void *context) | |
1da177e4 LT |
552 | { |
553 | struct kcopyd_job *job; | |
554 | ||
555 | /* | |
c6ea41fb MP |
556 | * Allocate an array of jobs consisting of one master job |
557 | * followed by SPLIT_COUNT sub jobs. | |
1da177e4 | 558 | */ |
08d8757a | 559 | job = mempool_alloc(kc->job_pool, GFP_NOIO); |
1da177e4 LT |
560 | |
561 | /* | |
562 | * set up for the read. | |
563 | */ | |
564 | job->kc = kc; | |
565 | job->flags = flags; | |
566 | job->read_err = 0; | |
567 | job->write_err = 0; | |
568 | job->rw = READ; | |
569 | ||
570 | job->source = *from; | |
571 | ||
572 | job->num_dests = num_dests; | |
573 | memcpy(&job->dests, dests, sizeof(*dests) * num_dests); | |
574 | ||
575 | job->offset = 0; | |
576 | job->nr_pages = 0; | |
577 | job->pages = NULL; | |
578 | ||
579 | job->fn = fn; | |
580 | job->context = context; | |
c6ea41fb | 581 | job->master_job = job; |
1da177e4 | 582 | |
a705a34a | 583 | if (job->source.count <= SUB_JOB_SIZE) |
1da177e4 | 584 | dispatch_job(job); |
1da177e4 | 585 | else { |
def5b5b2 | 586 | mutex_init(&job->lock); |
1da177e4 LT |
587 | job->progress = 0; |
588 | split_job(job); | |
589 | } | |
590 | ||
591 | return 0; | |
592 | } | |
eb69aca5 | 593 | EXPORT_SYMBOL(dm_kcopyd_copy); |
1da177e4 LT |
594 | |
595 | /* | |
596 | * Cancels a kcopyd job, eg. someone might be deactivating a | |
597 | * mirror. | |
598 | */ | |
0b56306e | 599 | #if 0 |
1da177e4 LT |
600 | int kcopyd_cancel(struct kcopyd_job *job, int block) |
601 | { | |
602 | /* FIXME: finish */ | |
603 | return -1; | |
604 | } | |
0b56306e | 605 | #endif /* 0 */ |
1da177e4 LT |
606 | |
607 | /*----------------------------------------------------------------- | |
945fa4d2 | 608 | * Client setup |
1da177e4 | 609 | *---------------------------------------------------------------*/ |
eb69aca5 HM |
610 | int dm_kcopyd_client_create(unsigned int nr_pages, |
611 | struct dm_kcopyd_client **result) | |
1da177e4 | 612 | { |
945fa4d2 | 613 | int r = -ENOMEM; |
eb69aca5 | 614 | struct dm_kcopyd_client *kc; |
1da177e4 | 615 | |
1da177e4 | 616 | kc = kmalloc(sizeof(*kc), GFP_KERNEL); |
945fa4d2 MP |
617 | if (!kc) |
618 | return -ENOMEM; | |
1da177e4 | 619 | |
8c0cbc2f MP |
620 | spin_lock_init(&kc->job_lock); |
621 | INIT_LIST_HEAD(&kc->complete_jobs); | |
622 | INIT_LIST_HEAD(&kc->io_jobs); | |
623 | INIT_LIST_HEAD(&kc->pages_jobs); | |
624 | ||
08d8757a | 625 | kc->job_pool = mempool_create_slab_pool(MIN_JOBS, _job_cache); |
945fa4d2 MP |
626 | if (!kc->job_pool) |
627 | goto bad_slab; | |
08d8757a | 628 | |
8c0cbc2f | 629 | INIT_WORK(&kc->kcopyd_work, do_work); |
9c4376de TH |
630 | kc->kcopyd_wq = alloc_workqueue("kcopyd", |
631 | WQ_NON_REENTRANT | WQ_MEM_RECLAIM, 0); | |
945fa4d2 MP |
632 | if (!kc->kcopyd_wq) |
633 | goto bad_workqueue; | |
8c0cbc2f | 634 | |
1da177e4 LT |
635 | kc->pages = NULL; |
636 | kc->nr_pages = kc->nr_free_pages = 0; | |
637 | r = client_alloc_pages(kc, nr_pages); | |
945fa4d2 MP |
638 | if (r) |
639 | goto bad_client_pages; | |
1da177e4 | 640 | |
373a392b MB |
641 | kc->io_client = dm_io_client_create(nr_pages); |
642 | if (IS_ERR(kc->io_client)) { | |
643 | r = PTR_ERR(kc->io_client); | |
945fa4d2 | 644 | goto bad_io_client; |
1da177e4 LT |
645 | } |
646 | ||
138728dc AK |
647 | init_waitqueue_head(&kc->destroyq); |
648 | atomic_set(&kc->nr_jobs, 0); | |
649 | ||
1da177e4 LT |
650 | *result = kc; |
651 | return 0; | |
945fa4d2 MP |
652 | |
653 | bad_io_client: | |
654 | client_free_pages(kc); | |
655 | bad_client_pages: | |
656 | destroy_workqueue(kc->kcopyd_wq); | |
657 | bad_workqueue: | |
658 | mempool_destroy(kc->job_pool); | |
659 | bad_slab: | |
660 | kfree(kc); | |
661 | ||
662 | return r; | |
1da177e4 | 663 | } |
eb69aca5 | 664 | EXPORT_SYMBOL(dm_kcopyd_client_create); |
1da177e4 | 665 | |
eb69aca5 | 666 | void dm_kcopyd_client_destroy(struct dm_kcopyd_client *kc) |
1da177e4 | 667 | { |
138728dc AK |
668 | /* Wait for completion of all jobs submitted by this client. */ |
669 | wait_event(kc->destroyq, !atomic_read(&kc->nr_jobs)); | |
670 | ||
8c0cbc2f MP |
671 | BUG_ON(!list_empty(&kc->complete_jobs)); |
672 | BUG_ON(!list_empty(&kc->io_jobs)); | |
673 | BUG_ON(!list_empty(&kc->pages_jobs)); | |
674 | destroy_workqueue(kc->kcopyd_wq); | |
373a392b | 675 | dm_io_client_destroy(kc->io_client); |
1da177e4 | 676 | client_free_pages(kc); |
08d8757a | 677 | mempool_destroy(kc->job_pool); |
1da177e4 | 678 | kfree(kc); |
1da177e4 | 679 | } |
eb69aca5 | 680 | EXPORT_SYMBOL(dm_kcopyd_client_destroy); |