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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> |
60063497 | 13 | #include <linux/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 | |
5f43ba29 | 33 | #define RESERVE_PAGES (DIV_ROUND_UP(SUB_JOB_SIZE << SECTOR_SHIFT, PAGE_SIZE)) |
c6ea41fb | 34 | |
1da177e4 LT |
35 | /*----------------------------------------------------------------- |
36 | * Each kcopyd client has its own little pool of preallocated | |
37 | * pages for kcopyd io. | |
38 | *---------------------------------------------------------------*/ | |
eb69aca5 | 39 | struct dm_kcopyd_client { |
1da177e4 | 40 | struct page_list *pages; |
d0471458 MP |
41 | unsigned nr_reserved_pages; |
42 | unsigned nr_free_pages; | |
138728dc | 43 | |
373a392b MB |
44 | struct dm_io_client *io_client; |
45 | ||
138728dc AK |
46 | wait_queue_head_t destroyq; |
47 | atomic_t nr_jobs; | |
8c0cbc2f | 48 | |
08d8757a MP |
49 | mempool_t *job_pool; |
50 | ||
8c0cbc2f MP |
51 | struct workqueue_struct *kcopyd_wq; |
52 | struct work_struct kcopyd_work; | |
53 | ||
54 | /* | |
55 | * We maintain three lists of jobs: | |
56 | * | |
57 | * i) jobs waiting for pages | |
58 | * ii) jobs that have pages, and are waiting for the io to be issued. | |
59 | * iii) jobs that have completed. | |
60 | * | |
61 | * All three of these are protected by job_lock. | |
62 | */ | |
63 | spinlock_t job_lock; | |
64 | struct list_head complete_jobs; | |
65 | struct list_head io_jobs; | |
66 | struct list_head pages_jobs; | |
1da177e4 LT |
67 | }; |
68 | ||
8c0cbc2f MP |
69 | static void wake(struct dm_kcopyd_client *kc) |
70 | { | |
71 | queue_work(kc->kcopyd_wq, &kc->kcopyd_work); | |
72 | } | |
73 | ||
d0471458 MP |
74 | /* |
75 | * Obtain one page for the use of kcopyd. | |
76 | */ | |
f99b55ee | 77 | static struct page_list *alloc_pl(gfp_t gfp) |
1da177e4 LT |
78 | { |
79 | struct page_list *pl; | |
80 | ||
f99b55ee | 81 | pl = kmalloc(sizeof(*pl), gfp); |
1da177e4 LT |
82 | if (!pl) |
83 | return NULL; | |
84 | ||
f99b55ee | 85 | pl->page = alloc_page(gfp); |
1da177e4 LT |
86 | if (!pl->page) { |
87 | kfree(pl); | |
88 | return NULL; | |
89 | } | |
90 | ||
91 | return pl; | |
92 | } | |
93 | ||
94 | static void free_pl(struct page_list *pl) | |
95 | { | |
96 | __free_page(pl->page); | |
97 | kfree(pl); | |
98 | } | |
99 | ||
d0471458 MP |
100 | /* |
101 | * Add the provided pages to a client's free page list, releasing | |
102 | * back to the system any beyond the reserved_pages limit. | |
103 | */ | |
104 | static void kcopyd_put_pages(struct dm_kcopyd_client *kc, struct page_list *pl) | |
1da177e4 | 105 | { |
d0471458 | 106 | struct page_list *next; |
1da177e4 | 107 | |
d0471458 MP |
108 | do { |
109 | next = pl->next; | |
1da177e4 | 110 | |
d0471458 MP |
111 | if (kc->nr_free_pages >= kc->nr_reserved_pages) |
112 | free_pl(pl); | |
113 | else { | |
114 | pl->next = kc->pages; | |
115 | kc->pages = pl; | |
116 | kc->nr_free_pages++; | |
117 | } | |
1da177e4 | 118 | |
d0471458 MP |
119 | pl = next; |
120 | } while (pl); | |
1da177e4 LT |
121 | } |
122 | ||
d0471458 MP |
123 | static int kcopyd_get_pages(struct dm_kcopyd_client *kc, |
124 | unsigned int nr, struct page_list **pages) | |
1da177e4 | 125 | { |
d0471458 | 126 | struct page_list *pl; |
1da177e4 | 127 | |
d0471458 MP |
128 | *pages = NULL; |
129 | ||
130 | do { | |
131 | pl = alloc_pl(__GFP_NOWARN | __GFP_NORETRY); | |
132 | if (unlikely(!pl)) { | |
133 | /* Use reserved pages */ | |
134 | pl = kc->pages; | |
135 | if (unlikely(!pl)) | |
136 | goto out_of_memory; | |
137 | kc->pages = pl->next; | |
138 | kc->nr_free_pages--; | |
139 | } | |
140 | pl->next = *pages; | |
141 | *pages = pl; | |
142 | } while (--nr); | |
143 | ||
144 | return 0; | |
1da177e4 | 145 | |
d0471458 MP |
146 | out_of_memory: |
147 | if (*pages) | |
148 | kcopyd_put_pages(kc, *pages); | |
149 | return -ENOMEM; | |
1da177e4 LT |
150 | } |
151 | ||
152 | /* | |
153 | * These three functions resize the page pool. | |
154 | */ | |
155 | static void drop_pages(struct page_list *pl) | |
156 | { | |
157 | struct page_list *next; | |
158 | ||
159 | while (pl) { | |
160 | next = pl->next; | |
161 | free_pl(pl); | |
162 | pl = next; | |
163 | } | |
164 | } | |
165 | ||
d0471458 MP |
166 | /* |
167 | * Allocate and reserve nr_pages for the use of a specific client. | |
168 | */ | |
169 | static int client_reserve_pages(struct dm_kcopyd_client *kc, unsigned nr_pages) | |
1da177e4 | 170 | { |
d0471458 | 171 | unsigned i; |
1da177e4 LT |
172 | struct page_list *pl = NULL, *next; |
173 | ||
d0471458 | 174 | for (i = 0; i < nr_pages; i++) { |
f99b55ee | 175 | next = alloc_pl(GFP_KERNEL); |
1da177e4 LT |
176 | if (!next) { |
177 | if (pl) | |
178 | drop_pages(pl); | |
179 | return -ENOMEM; | |
180 | } | |
181 | next->next = pl; | |
182 | pl = next; | |
183 | } | |
184 | ||
d0471458 | 185 | kc->nr_reserved_pages += nr_pages; |
1da177e4 | 186 | kcopyd_put_pages(kc, pl); |
d0471458 | 187 | |
1da177e4 LT |
188 | return 0; |
189 | } | |
190 | ||
eb69aca5 | 191 | static void client_free_pages(struct dm_kcopyd_client *kc) |
1da177e4 | 192 | { |
d0471458 | 193 | BUG_ON(kc->nr_free_pages != kc->nr_reserved_pages); |
1da177e4 LT |
194 | drop_pages(kc->pages); |
195 | kc->pages = NULL; | |
d0471458 | 196 | kc->nr_free_pages = kc->nr_reserved_pages = 0; |
1da177e4 LT |
197 | } |
198 | ||
199 | /*----------------------------------------------------------------- | |
200 | * kcopyd_jobs need to be allocated by the *clients* of kcopyd, | |
201 | * for this reason we use a mempool to prevent the client from | |
202 | * ever having to do io (which could cause a deadlock). | |
203 | *---------------------------------------------------------------*/ | |
204 | struct kcopyd_job { | |
eb69aca5 | 205 | struct dm_kcopyd_client *kc; |
1da177e4 LT |
206 | struct list_head list; |
207 | unsigned long flags; | |
208 | ||
209 | /* | |
210 | * Error state of the job. | |
211 | */ | |
212 | int read_err; | |
4cdc1d1f | 213 | unsigned long write_err; |
1da177e4 LT |
214 | |
215 | /* | |
216 | * Either READ or WRITE | |
217 | */ | |
218 | int rw; | |
22a1ceb1 | 219 | struct dm_io_region source; |
1da177e4 LT |
220 | |
221 | /* | |
222 | * The destinations for the transfer. | |
223 | */ | |
224 | unsigned int num_dests; | |
eb69aca5 | 225 | struct dm_io_region dests[DM_KCOPYD_MAX_REGIONS]; |
1da177e4 | 226 | |
1da177e4 LT |
227 | unsigned int nr_pages; |
228 | struct page_list *pages; | |
229 | ||
230 | /* | |
231 | * Set this to ensure you are notified when the job has | |
232 | * completed. 'context' is for callback to use. | |
233 | */ | |
eb69aca5 | 234 | dm_kcopyd_notify_fn fn; |
1da177e4 LT |
235 | void *context; |
236 | ||
237 | /* | |
238 | * These fields are only used if the job has been split | |
239 | * into more manageable parts. | |
240 | */ | |
def5b5b2 | 241 | struct mutex lock; |
1da177e4 LT |
242 | atomic_t sub_jobs; |
243 | sector_t progress; | |
1da177e4 | 244 | |
c6ea41fb MP |
245 | struct kcopyd_job *master_job; |
246 | }; | |
1da177e4 | 247 | |
e18b890b | 248 | static struct kmem_cache *_job_cache; |
1da177e4 | 249 | |
945fa4d2 | 250 | int __init dm_kcopyd_init(void) |
1da177e4 | 251 | { |
c6ea41fb MP |
252 | _job_cache = kmem_cache_create("kcopyd_job", |
253 | sizeof(struct kcopyd_job) * (SPLIT_COUNT + 1), | |
254 | __alignof__(struct kcopyd_job), 0, NULL); | |
1da177e4 LT |
255 | if (!_job_cache) |
256 | return -ENOMEM; | |
257 | ||
1da177e4 LT |
258 | return 0; |
259 | } | |
260 | ||
945fa4d2 | 261 | void dm_kcopyd_exit(void) |
1da177e4 | 262 | { |
1da177e4 | 263 | kmem_cache_destroy(_job_cache); |
1da177e4 LT |
264 | _job_cache = NULL; |
265 | } | |
266 | ||
267 | /* | |
268 | * Functions to push and pop a job onto the head of a given job | |
269 | * list. | |
270 | */ | |
8c0cbc2f MP |
271 | static struct kcopyd_job *pop(struct list_head *jobs, |
272 | struct dm_kcopyd_client *kc) | |
1da177e4 LT |
273 | { |
274 | struct kcopyd_job *job = NULL; | |
275 | unsigned long flags; | |
276 | ||
8c0cbc2f | 277 | spin_lock_irqsave(&kc->job_lock, flags); |
1da177e4 LT |
278 | |
279 | if (!list_empty(jobs)) { | |
280 | job = list_entry(jobs->next, struct kcopyd_job, list); | |
281 | list_del(&job->list); | |
282 | } | |
8c0cbc2f | 283 | spin_unlock_irqrestore(&kc->job_lock, flags); |
1da177e4 LT |
284 | |
285 | return job; | |
286 | } | |
287 | ||
028867ac | 288 | static void push(struct list_head *jobs, struct kcopyd_job *job) |
1da177e4 LT |
289 | { |
290 | unsigned long flags; | |
8c0cbc2f | 291 | struct dm_kcopyd_client *kc = job->kc; |
1da177e4 | 292 | |
8c0cbc2f | 293 | spin_lock_irqsave(&kc->job_lock, flags); |
1da177e4 | 294 | list_add_tail(&job->list, jobs); |
8c0cbc2f | 295 | spin_unlock_irqrestore(&kc->job_lock, flags); |
1da177e4 LT |
296 | } |
297 | ||
b673c3a8 KI |
298 | |
299 | static void push_head(struct list_head *jobs, struct kcopyd_job *job) | |
300 | { | |
301 | unsigned long flags; | |
302 | struct dm_kcopyd_client *kc = job->kc; | |
303 | ||
304 | spin_lock_irqsave(&kc->job_lock, flags); | |
305 | list_add(&job->list, jobs); | |
306 | spin_unlock_irqrestore(&kc->job_lock, flags); | |
307 | } | |
308 | ||
1da177e4 LT |
309 | /* |
310 | * These three functions process 1 item from the corresponding | |
311 | * job list. | |
312 | * | |
313 | * They return: | |
314 | * < 0: error | |
315 | * 0: success | |
316 | * > 0: can't process yet. | |
317 | */ | |
318 | static int run_complete_job(struct kcopyd_job *job) | |
319 | { | |
320 | void *context = job->context; | |
321 | int read_err = job->read_err; | |
4cdc1d1f | 322 | unsigned long write_err = job->write_err; |
eb69aca5 HM |
323 | dm_kcopyd_notify_fn fn = job->fn; |
324 | struct dm_kcopyd_client *kc = job->kc; | |
1da177e4 | 325 | |
73830857 MP |
326 | if (job->pages) |
327 | kcopyd_put_pages(kc, job->pages); | |
c6ea41fb MP |
328 | /* |
329 | * If this is the master job, the sub jobs have already | |
330 | * completed so we can free everything. | |
331 | */ | |
332 | if (job->master_job == job) | |
333 | mempool_free(job, kc->job_pool); | |
1da177e4 | 334 | fn(read_err, write_err, context); |
138728dc AK |
335 | |
336 | if (atomic_dec_and_test(&kc->nr_jobs)) | |
337 | wake_up(&kc->destroyq); | |
338 | ||
1da177e4 LT |
339 | return 0; |
340 | } | |
341 | ||
342 | static void complete_io(unsigned long error, void *context) | |
343 | { | |
344 | struct kcopyd_job *job = (struct kcopyd_job *) context; | |
8c0cbc2f | 345 | struct dm_kcopyd_client *kc = job->kc; |
1da177e4 LT |
346 | |
347 | if (error) { | |
348 | if (job->rw == WRITE) | |
ce503f59 | 349 | job->write_err |= error; |
1da177e4 LT |
350 | else |
351 | job->read_err = 1; | |
352 | ||
eb69aca5 | 353 | if (!test_bit(DM_KCOPYD_IGNORE_ERROR, &job->flags)) { |
8c0cbc2f MP |
354 | push(&kc->complete_jobs, job); |
355 | wake(kc); | |
1da177e4 LT |
356 | return; |
357 | } | |
358 | } | |
359 | ||
360 | if (job->rw == WRITE) | |
8c0cbc2f | 361 | push(&kc->complete_jobs, job); |
1da177e4 LT |
362 | |
363 | else { | |
364 | job->rw = WRITE; | |
8c0cbc2f | 365 | push(&kc->io_jobs, job); |
1da177e4 LT |
366 | } |
367 | ||
8c0cbc2f | 368 | wake(kc); |
1da177e4 LT |
369 | } |
370 | ||
371 | /* | |
372 | * Request io on as many buffer heads as we can currently get for | |
373 | * a particular job. | |
374 | */ | |
375 | static int run_io_job(struct kcopyd_job *job) | |
376 | { | |
377 | int r; | |
373a392b | 378 | struct dm_io_request io_req = { |
8d35d3e3 | 379 | .bi_rw = job->rw, |
373a392b MB |
380 | .mem.type = DM_IO_PAGE_LIST, |
381 | .mem.ptr.pl = job->pages, | |
4622afb3 | 382 | .mem.offset = 0, |
373a392b MB |
383 | .notify.fn = complete_io, |
384 | .notify.context = job, | |
385 | .client = job->kc->io_client, | |
386 | }; | |
1da177e4 | 387 | |
7eaceacc | 388 | if (job->rw == READ) |
373a392b | 389 | r = dm_io(&io_req, 1, &job->source, NULL); |
721a9602 | 390 | else |
373a392b | 391 | r = dm_io(&io_req, job->num_dests, job->dests, NULL); |
1da177e4 LT |
392 | |
393 | return r; | |
394 | } | |
395 | ||
396 | static int run_pages_job(struct kcopyd_job *job) | |
397 | { | |
398 | int r; | |
399 | ||
4622afb3 | 400 | job->nr_pages = dm_div_up(job->dests[0].count, PAGE_SIZE >> 9); |
1da177e4 LT |
401 | r = kcopyd_get_pages(job->kc, job->nr_pages, &job->pages); |
402 | if (!r) { | |
403 | /* this job is ready for io */ | |
8c0cbc2f | 404 | push(&job->kc->io_jobs, job); |
1da177e4 LT |
405 | return 0; |
406 | } | |
407 | ||
408 | if (r == -ENOMEM) | |
409 | /* can't complete now */ | |
410 | return 1; | |
411 | ||
412 | return r; | |
413 | } | |
414 | ||
415 | /* | |
416 | * Run through a list for as long as possible. Returns the count | |
417 | * of successful jobs. | |
418 | */ | |
8c0cbc2f MP |
419 | static int process_jobs(struct list_head *jobs, struct dm_kcopyd_client *kc, |
420 | int (*fn) (struct kcopyd_job *)) | |
1da177e4 LT |
421 | { |
422 | struct kcopyd_job *job; | |
423 | int r, count = 0; | |
424 | ||
8c0cbc2f | 425 | while ((job = pop(jobs, kc))) { |
1da177e4 LT |
426 | |
427 | r = fn(job); | |
428 | ||
429 | if (r < 0) { | |
430 | /* error this rogue job */ | |
431 | if (job->rw == WRITE) | |
4cdc1d1f | 432 | job->write_err = (unsigned long) -1L; |
1da177e4 LT |
433 | else |
434 | job->read_err = 1; | |
8c0cbc2f | 435 | push(&kc->complete_jobs, job); |
1da177e4 LT |
436 | break; |
437 | } | |
438 | ||
439 | if (r > 0) { | |
440 | /* | |
441 | * We couldn't service this job ATM, so | |
442 | * push this job back onto the list. | |
443 | */ | |
b673c3a8 | 444 | push_head(jobs, job); |
1da177e4 LT |
445 | break; |
446 | } | |
447 | ||
448 | count++; | |
449 | } | |
450 | ||
451 | return count; | |
452 | } | |
453 | ||
454 | /* | |
455 | * kcopyd does this every time it's woken up. | |
456 | */ | |
8c0cbc2f | 457 | static void do_work(struct work_struct *work) |
1da177e4 | 458 | { |
8c0cbc2f MP |
459 | struct dm_kcopyd_client *kc = container_of(work, |
460 | struct dm_kcopyd_client, kcopyd_work); | |
7eaceacc | 461 | struct blk_plug plug; |
8c0cbc2f | 462 | |
1da177e4 LT |
463 | /* |
464 | * The order that these are called is *very* important. | |
465 | * complete jobs can free some pages for pages jobs. | |
466 | * Pages jobs when successful will jump onto the io jobs | |
467 | * list. io jobs call wake when they complete and it all | |
468 | * starts again. | |
469 | */ | |
7eaceacc | 470 | blk_start_plug(&plug); |
8c0cbc2f MP |
471 | process_jobs(&kc->complete_jobs, kc, run_complete_job); |
472 | process_jobs(&kc->pages_jobs, kc, run_pages_job); | |
473 | process_jobs(&kc->io_jobs, kc, run_io_job); | |
7eaceacc | 474 | blk_finish_plug(&plug); |
1da177e4 LT |
475 | } |
476 | ||
477 | /* | |
478 | * If we are copying a small region we just dispatch a single job | |
479 | * to do the copy, otherwise the io has to be split up into many | |
480 | * jobs. | |
481 | */ | |
482 | static void dispatch_job(struct kcopyd_job *job) | |
483 | { | |
8c0cbc2f MP |
484 | struct dm_kcopyd_client *kc = job->kc; |
485 | atomic_inc(&kc->nr_jobs); | |
9ca170a3 MP |
486 | if (unlikely(!job->source.count)) |
487 | push(&kc->complete_jobs, job); | |
488 | else | |
489 | push(&kc->pages_jobs, job); | |
8c0cbc2f | 490 | wake(kc); |
1da177e4 LT |
491 | } |
492 | ||
4cdc1d1f AK |
493 | static void segment_complete(int read_err, unsigned long write_err, |
494 | void *context) | |
1da177e4 LT |
495 | { |
496 | /* FIXME: tidy this function */ | |
497 | sector_t progress = 0; | |
498 | sector_t count = 0; | |
c6ea41fb MP |
499 | struct kcopyd_job *sub_job = (struct kcopyd_job *) context; |
500 | struct kcopyd_job *job = sub_job->master_job; | |
73830857 | 501 | struct dm_kcopyd_client *kc = job->kc; |
1da177e4 | 502 | |
def5b5b2 | 503 | mutex_lock(&job->lock); |
1da177e4 LT |
504 | |
505 | /* update the error */ | |
506 | if (read_err) | |
507 | job->read_err = 1; | |
508 | ||
509 | if (write_err) | |
ce503f59 | 510 | job->write_err |= write_err; |
1da177e4 LT |
511 | |
512 | /* | |
513 | * Only dispatch more work if there hasn't been an error. | |
514 | */ | |
515 | if ((!job->read_err && !job->write_err) || | |
eb69aca5 | 516 | test_bit(DM_KCOPYD_IGNORE_ERROR, &job->flags)) { |
1da177e4 LT |
517 | /* get the next chunk of work */ |
518 | progress = job->progress; | |
519 | count = job->source.count - progress; | |
520 | if (count) { | |
521 | if (count > SUB_JOB_SIZE) | |
522 | count = SUB_JOB_SIZE; | |
523 | ||
524 | job->progress += count; | |
525 | } | |
526 | } | |
def5b5b2 | 527 | mutex_unlock(&job->lock); |
1da177e4 LT |
528 | |
529 | if (count) { | |
530 | int i; | |
1da177e4 LT |
531 | |
532 | *sub_job = *job; | |
533 | sub_job->source.sector += progress; | |
534 | sub_job->source.count = count; | |
535 | ||
536 | for (i = 0; i < job->num_dests; i++) { | |
537 | sub_job->dests[i].sector += progress; | |
538 | sub_job->dests[i].count = count; | |
539 | } | |
540 | ||
541 | sub_job->fn = segment_complete; | |
c6ea41fb | 542 | sub_job->context = sub_job; |
1da177e4 LT |
543 | dispatch_job(sub_job); |
544 | ||
545 | } else if (atomic_dec_and_test(&job->sub_jobs)) { | |
546 | ||
547 | /* | |
340cd444 MP |
548 | * Queue the completion callback to the kcopyd thread. |
549 | * | |
550 | * Some callers assume that all the completions are called | |
551 | * from a single thread and don't race with each other. | |
552 | * | |
553 | * We must not call the callback directly here because this | |
554 | * code may not be executing in the thread. | |
1da177e4 | 555 | */ |
340cd444 MP |
556 | push(&kc->complete_jobs, job); |
557 | wake(kc); | |
1da177e4 LT |
558 | } |
559 | } | |
560 | ||
561 | /* | |
c6ea41fb | 562 | * Create some sub jobs to share the work between them. |
1da177e4 | 563 | */ |
c6ea41fb | 564 | static void split_job(struct kcopyd_job *master_job) |
1da177e4 LT |
565 | { |
566 | int i; | |
567 | ||
c6ea41fb | 568 | atomic_inc(&master_job->kc->nr_jobs); |
340cd444 | 569 | |
c6ea41fb MP |
570 | atomic_set(&master_job->sub_jobs, SPLIT_COUNT); |
571 | for (i = 0; i < SPLIT_COUNT; i++) { | |
572 | master_job[i + 1].master_job = master_job; | |
573 | segment_complete(0, 0u, &master_job[i + 1]); | |
574 | } | |
1da177e4 LT |
575 | } |
576 | ||
eb69aca5 HM |
577 | int dm_kcopyd_copy(struct dm_kcopyd_client *kc, struct dm_io_region *from, |
578 | unsigned int num_dests, struct dm_io_region *dests, | |
579 | unsigned int flags, dm_kcopyd_notify_fn fn, void *context) | |
1da177e4 LT |
580 | { |
581 | struct kcopyd_job *job; | |
582 | ||
583 | /* | |
c6ea41fb MP |
584 | * Allocate an array of jobs consisting of one master job |
585 | * followed by SPLIT_COUNT sub jobs. | |
1da177e4 | 586 | */ |
08d8757a | 587 | job = mempool_alloc(kc->job_pool, GFP_NOIO); |
1da177e4 LT |
588 | |
589 | /* | |
590 | * set up for the read. | |
591 | */ | |
592 | job->kc = kc; | |
593 | job->flags = flags; | |
594 | job->read_err = 0; | |
595 | job->write_err = 0; | |
596 | job->rw = READ; | |
597 | ||
598 | job->source = *from; | |
599 | ||
600 | job->num_dests = num_dests; | |
601 | memcpy(&job->dests, dests, sizeof(*dests) * num_dests); | |
602 | ||
1da177e4 LT |
603 | job->nr_pages = 0; |
604 | job->pages = NULL; | |
605 | ||
606 | job->fn = fn; | |
607 | job->context = context; | |
c6ea41fb | 608 | job->master_job = job; |
1da177e4 | 609 | |
a705a34a | 610 | if (job->source.count <= SUB_JOB_SIZE) |
1da177e4 | 611 | dispatch_job(job); |
1da177e4 | 612 | else { |
def5b5b2 | 613 | mutex_init(&job->lock); |
1da177e4 LT |
614 | job->progress = 0; |
615 | split_job(job); | |
616 | } | |
617 | ||
618 | return 0; | |
619 | } | |
eb69aca5 | 620 | EXPORT_SYMBOL(dm_kcopyd_copy); |
1da177e4 LT |
621 | |
622 | /* | |
623 | * Cancels a kcopyd job, eg. someone might be deactivating a | |
624 | * mirror. | |
625 | */ | |
0b56306e | 626 | #if 0 |
1da177e4 LT |
627 | int kcopyd_cancel(struct kcopyd_job *job, int block) |
628 | { | |
629 | /* FIXME: finish */ | |
630 | return -1; | |
631 | } | |
0b56306e | 632 | #endif /* 0 */ |
1da177e4 LT |
633 | |
634 | /*----------------------------------------------------------------- | |
945fa4d2 | 635 | * Client setup |
1da177e4 | 636 | *---------------------------------------------------------------*/ |
fa34ce73 | 637 | struct dm_kcopyd_client *dm_kcopyd_client_create(void) |
1da177e4 | 638 | { |
945fa4d2 | 639 | int r = -ENOMEM; |
eb69aca5 | 640 | struct dm_kcopyd_client *kc; |
1da177e4 | 641 | |
1da177e4 | 642 | kc = kmalloc(sizeof(*kc), GFP_KERNEL); |
945fa4d2 | 643 | if (!kc) |
fa34ce73 | 644 | return ERR_PTR(-ENOMEM); |
1da177e4 | 645 | |
8c0cbc2f MP |
646 | spin_lock_init(&kc->job_lock); |
647 | INIT_LIST_HEAD(&kc->complete_jobs); | |
648 | INIT_LIST_HEAD(&kc->io_jobs); | |
649 | INIT_LIST_HEAD(&kc->pages_jobs); | |
650 | ||
08d8757a | 651 | kc->job_pool = mempool_create_slab_pool(MIN_JOBS, _job_cache); |
945fa4d2 MP |
652 | if (!kc->job_pool) |
653 | goto bad_slab; | |
08d8757a | 654 | |
8c0cbc2f | 655 | INIT_WORK(&kc->kcopyd_work, do_work); |
9c4376de TH |
656 | kc->kcopyd_wq = alloc_workqueue("kcopyd", |
657 | WQ_NON_REENTRANT | WQ_MEM_RECLAIM, 0); | |
945fa4d2 MP |
658 | if (!kc->kcopyd_wq) |
659 | goto bad_workqueue; | |
8c0cbc2f | 660 | |
1da177e4 | 661 | kc->pages = NULL; |
d0471458 | 662 | kc->nr_reserved_pages = kc->nr_free_pages = 0; |
5f43ba29 | 663 | r = client_reserve_pages(kc, RESERVE_PAGES); |
945fa4d2 MP |
664 | if (r) |
665 | goto bad_client_pages; | |
1da177e4 | 666 | |
bda8efec | 667 | kc->io_client = dm_io_client_create(); |
373a392b MB |
668 | if (IS_ERR(kc->io_client)) { |
669 | r = PTR_ERR(kc->io_client); | |
945fa4d2 | 670 | goto bad_io_client; |
1da177e4 LT |
671 | } |
672 | ||
138728dc AK |
673 | init_waitqueue_head(&kc->destroyq); |
674 | atomic_set(&kc->nr_jobs, 0); | |
675 | ||
fa34ce73 | 676 | return kc; |
945fa4d2 MP |
677 | |
678 | bad_io_client: | |
679 | client_free_pages(kc); | |
680 | bad_client_pages: | |
681 | destroy_workqueue(kc->kcopyd_wq); | |
682 | bad_workqueue: | |
683 | mempool_destroy(kc->job_pool); | |
684 | bad_slab: | |
685 | kfree(kc); | |
686 | ||
fa34ce73 | 687 | return ERR_PTR(r); |
1da177e4 | 688 | } |
eb69aca5 | 689 | EXPORT_SYMBOL(dm_kcopyd_client_create); |
1da177e4 | 690 | |
eb69aca5 | 691 | void dm_kcopyd_client_destroy(struct dm_kcopyd_client *kc) |
1da177e4 | 692 | { |
138728dc AK |
693 | /* Wait for completion of all jobs submitted by this client. */ |
694 | wait_event(kc->destroyq, !atomic_read(&kc->nr_jobs)); | |
695 | ||
8c0cbc2f MP |
696 | BUG_ON(!list_empty(&kc->complete_jobs)); |
697 | BUG_ON(!list_empty(&kc->io_jobs)); | |
698 | BUG_ON(!list_empty(&kc->pages_jobs)); | |
699 | destroy_workqueue(kc->kcopyd_wq); | |
373a392b | 700 | dm_io_client_destroy(kc->io_client); |
1da177e4 | 701 | client_free_pages(kc); |
08d8757a | 702 | mempool_destroy(kc->job_pool); |
1da177e4 | 703 | kfree(kc); |
1da177e4 | 704 | } |
eb69aca5 | 705 | EXPORT_SYMBOL(dm_kcopyd_client_destroy); |