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path: root/drivers/md/dm-kcopyd.c
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Diffstat (limited to 'drivers/md/dm-kcopyd.c')
-rw-r--r--drivers/md/dm-kcopyd.c52
1 files changed, 5 insertions, 47 deletions
diff --git a/drivers/md/dm-kcopyd.c b/drivers/md/dm-kcopyd.c
index 924f5f0084c2..400cf35094a4 100644
--- a/drivers/md/dm-kcopyd.c
+++ b/drivers/md/dm-kcopyd.c
@@ -37,13 +37,6 @@ struct dm_kcopyd_client {
37 unsigned int nr_pages; 37 unsigned int nr_pages;
38 unsigned int nr_free_pages; 38 unsigned int nr_free_pages;
39 39
40 /*
41 * Block devices to unplug.
42 * Non-NULL pointer means that a block device has some pending requests
43 * and needs to be unplugged.
44 */
45 struct block_device *unplug[2];
46
47 struct dm_io_client *io_client; 40 struct dm_io_client *io_client;
48 41
49 wait_queue_head_t destroyq; 42 wait_queue_head_t destroyq;
@@ -315,31 +308,6 @@ static int run_complete_job(struct kcopyd_job *job)
315 return 0; 308 return 0;
316} 309}
317 310
318/*
319 * Unplug the block device at the specified index.
320 */
321static void unplug(struct dm_kcopyd_client *kc, int rw)
322{
323 if (kc->unplug[rw] != NULL) {
324 blk_unplug(bdev_get_queue(kc->unplug[rw]));
325 kc->unplug[rw] = NULL;
326 }
327}
328
329/*
330 * Prepare block device unplug. If there's another device
331 * to be unplugged at the same array index, we unplug that
332 * device first.
333 */
334static void prepare_unplug(struct dm_kcopyd_client *kc, int rw,
335 struct block_device *bdev)
336{
337 if (likely(kc->unplug[rw] == bdev))
338 return;
339 unplug(kc, rw);
340 kc->unplug[rw] = bdev;
341}
342
343static void complete_io(unsigned long error, void *context) 311static void complete_io(unsigned long error, void *context)
344{ 312{
345 struct kcopyd_job *job = (struct kcopyd_job *) context; 313 struct kcopyd_job *job = (struct kcopyd_job *) context;
@@ -386,15 +354,12 @@ static int run_io_job(struct kcopyd_job *job)
386 .client = job->kc->io_client, 354 .client = job->kc->io_client,
387 }; 355 };
388 356
389 if (job->rw == READ) { 357 if (job->rw == READ)
390 r = dm_io(&io_req, 1, &job->source, NULL); 358 r = dm_io(&io_req, 1, &job->source, NULL);
391 prepare_unplug(job->kc, READ, job->source.bdev); 359 else {
392 } else {
393 if (job->num_dests > 1) 360 if (job->num_dests > 1)
394 io_req.bi_rw |= REQ_UNPLUG; 361 io_req.bi_rw |= REQ_UNPLUG;
395 r = dm_io(&io_req, job->num_dests, job->dests, NULL); 362 r = dm_io(&io_req, job->num_dests, job->dests, NULL);
396 if (!(io_req.bi_rw & REQ_UNPLUG))
397 prepare_unplug(job->kc, WRITE, job->dests[0].bdev);
398 } 363 }
399 364
400 return r; 365 return r;
@@ -466,6 +431,7 @@ static void do_work(struct work_struct *work)
466{ 431{
467 struct dm_kcopyd_client *kc = container_of(work, 432 struct dm_kcopyd_client *kc = container_of(work,
468 struct dm_kcopyd_client, kcopyd_work); 433 struct dm_kcopyd_client, kcopyd_work);
434 struct blk_plug plug;
469 435
470 /* 436 /*
471 * The order that these are called is *very* important. 437 * The order that these are called is *very* important.
@@ -473,18 +439,12 @@ static void do_work(struct work_struct *work)
473 * Pages jobs when successful will jump onto the io jobs 439 * Pages jobs when successful will jump onto the io jobs
474 * list. io jobs call wake when they complete and it all 440 * list. io jobs call wake when they complete and it all
475 * starts again. 441 * starts again.
476 *
477 * Note that io_jobs add block devices to the unplug array,
478 * this array is cleared with "unplug" calls. It is thus
479 * forbidden to run complete_jobs after io_jobs and before
480 * unplug because the block device could be destroyed in
481 * job completion callback.
482 */ 442 */
443 blk_start_plug(&plug);
483 process_jobs(&kc->complete_jobs, kc, run_complete_job); 444 process_jobs(&kc->complete_jobs, kc, run_complete_job);
484 process_jobs(&kc->pages_jobs, kc, run_pages_job); 445 process_jobs(&kc->pages_jobs, kc, run_pages_job);
485 process_jobs(&kc->io_jobs, kc, run_io_job); 446 process_jobs(&kc->io_jobs, kc, run_io_job);
486 unplug(kc, READ); 447 blk_finish_plug(&plug);
487 unplug(kc, WRITE);
488} 448}
489 449
490/* 450/*
@@ -665,8 +625,6 @@ int dm_kcopyd_client_create(unsigned int nr_pages,
665 INIT_LIST_HEAD(&kc->io_jobs); 625 INIT_LIST_HEAD(&kc->io_jobs);
666 INIT_LIST_HEAD(&kc->pages_jobs); 626 INIT_LIST_HEAD(&kc->pages_jobs);
667 627
668 memset(kc->unplug, 0, sizeof(kc->unplug));
669
670 kc->job_pool = mempool_create_slab_pool(MIN_JOBS, _job_cache); 628 kc->job_pool = mempool_create_slab_pool(MIN_JOBS, _job_cache);
671 if (!kc->job_pool) 629 if (!kc->job_pool)
672 goto bad_slab; 630 goto bad_slab;