From eca7ee6dc01b21c669bce8c39d3d368509fb65e8 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Sat, 20 Feb 2016 13:45:38 -0500 Subject: dm: distinquish old .request_fn (dm-old) vs dm-mq request-based DM Rename various methods to have either a "dm_old" or "dm_mq" prefix. Improve code comments to assist with understanding the duality of code that handles both "dm_old" and "dm_mq" cases. It is no much easier to quickly look at the code and _know_ that a given method is either 1) "dm_old" only 2) "dm_mq" only 3) common to both. Signed-off-by: Mike Snitzer --- drivers/md/dm-mpath.c | 6 ++- drivers/md/dm.c | 102 ++++++++++++++++++++++++++------------------------ 2 files changed, 58 insertions(+), 50 deletions(-) (limited to 'drivers') diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index 7259eeba6a58..fde08c9809ef 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -426,7 +426,11 @@ static int __multipath_map(struct dm_target *ti, struct request *clone, clone->rq_disk = bdev->bd_disk; clone->cmd_flags |= REQ_FAILFAST_TRANSPORT; } else { - /* blk-mq request-based interface */ + /* + * blk-mq request-based interface; used by both: + * .request_fn stacked on blk-mq path(s) and + * blk-mq stacked on blk-mq path(s). + */ *__clone = blk_get_request(bdev_get_queue(bdev), rq_data_dir(rq), GFP_ATOMIC); if (IS_ERR(*__clone)) { diff --git a/drivers/md/dm.c b/drivers/md/dm.c index 26fedd93702e..d4040e6d4d3d 100644 --- a/drivers/md/dm.c +++ b/drivers/md/dm.c @@ -333,7 +333,7 @@ static int __init local_init(void) if (!_rq_tio_cache) goto out_free_io_cache; - _rq_cache = kmem_cache_create("dm_clone_request", sizeof(struct request), + _rq_cache = kmem_cache_create("dm_old_clone_request", sizeof(struct request), __alignof__(struct request), 0, NULL); if (!_rq_cache) goto out_free_rq_tio_cache; @@ -652,24 +652,24 @@ static void free_tio(struct mapped_device *md, struct dm_target_io *tio) bio_put(&tio->clone); } -static struct dm_rq_target_io *alloc_rq_tio(struct mapped_device *md, - gfp_t gfp_mask) +static struct dm_rq_target_io *alloc_old_rq_tio(struct mapped_device *md, + gfp_t gfp_mask) { return mempool_alloc(md->io_pool, gfp_mask); } -static void free_rq_tio(struct dm_rq_target_io *tio) +static void free_old_rq_tio(struct dm_rq_target_io *tio) { mempool_free(tio, tio->md->io_pool); } -static struct request *alloc_clone_request(struct mapped_device *md, - gfp_t gfp_mask) +static struct request *alloc_old_clone_request(struct mapped_device *md, + gfp_t gfp_mask) { return mempool_alloc(md->rq_pool, gfp_mask); } -static void free_clone_request(struct mapped_device *md, struct request *rq) +static void free_old_clone_request(struct mapped_device *md, struct request *rq) { mempool_free(rq, md->rq_pool); } @@ -1140,10 +1140,10 @@ static void free_rq_clone(struct request *clone) tio->ti->type->release_clone_rq(clone); else if (!md->queue->mq_ops) /* request_fn queue stacked on request_fn queue(s) */ - free_clone_request(md, clone); + free_old_clone_request(md, clone); if (!md->queue->mq_ops) - free_rq_tio(tio); + free_old_rq_tio(tio); } /* @@ -1193,13 +1193,13 @@ static void dm_unprep_request(struct request *rq) if (clone) free_rq_clone(clone); else if (!tio->md->queue->mq_ops) - free_rq_tio(tio); + free_old_rq_tio(tio); } /* * Requeue the original request of a clone. */ -static void old_requeue_request(struct request *rq) +static void dm_old_requeue_request(struct request *rq) { struct request_queue *q = rq->q; unsigned long flags; @@ -1231,14 +1231,14 @@ static void dm_requeue_original_request(struct mapped_device *md, rq_end_stats(md, rq); if (!rq->q->mq_ops) - old_requeue_request(rq); + dm_old_requeue_request(rq); else dm_mq_requeue_request(rq); rq_completed(md, rw, false); } -static void old_stop_queue(struct request_queue *q) +static void dm_old_stop_queue(struct request_queue *q) { unsigned long flags; @@ -1252,15 +1252,15 @@ static void old_stop_queue(struct request_queue *q) spin_unlock_irqrestore(q->queue_lock, flags); } -static void stop_queue(struct request_queue *q) +static void dm_stop_queue(struct request_queue *q) { if (!q->mq_ops) - old_stop_queue(q); + dm_old_stop_queue(q); else blk_mq_stop_hw_queues(q); } -static void old_start_queue(struct request_queue *q) +static void dm_old_start_queue(struct request_queue *q) { unsigned long flags; @@ -1270,10 +1270,10 @@ static void old_start_queue(struct request_queue *q) spin_unlock_irqrestore(q->queue_lock, flags); } -static void start_queue(struct request_queue *q) +static void dm_start_queue(struct request_queue *q) { if (!q->mq_ops) - old_start_queue(q); + dm_old_start_queue(q); else { blk_mq_start_stopped_hw_queues(q, true); blk_mq_kick_requeue_list(q); @@ -1328,7 +1328,7 @@ static void dm_softirq_done(struct request *rq) if (!rq->q->mq_ops) { blk_end_request_all(rq, tio->error); rq_completed(tio->md, rw, false); - free_rq_tio(tio); + free_old_rq_tio(tio); } else { blk_mq_end_request(rq, tio->error); rq_completed(tio->md, rw, false); @@ -1370,7 +1370,7 @@ static void dm_kill_unmapped_request(struct request *rq, int error) } /* - * Called with the clone's queue lock held (for non-blk-mq) + * Called with the clone's queue lock held (in the case of .request_fn) */ static void end_clone_request(struct request *clone, int error) { @@ -1857,22 +1857,22 @@ static int setup_clone(struct request *clone, struct request *rq, return 0; } -static struct request *clone_rq(struct request *rq, struct mapped_device *md, - struct dm_rq_target_io *tio, gfp_t gfp_mask) +static struct request *clone_old_rq(struct request *rq, struct mapped_device *md, + struct dm_rq_target_io *tio, gfp_t gfp_mask) { /* * Create clone for use with .request_fn request_queue */ struct request *clone; - clone = alloc_clone_request(md, gfp_mask); + clone = alloc_old_clone_request(md, gfp_mask); if (!clone) return NULL; blk_rq_init(NULL, clone); if (setup_clone(clone, rq, tio, gfp_mask)) { /* -ENOMEM */ - free_clone_request(md, clone); + free_old_clone_request(md, clone); return NULL; } @@ -1894,24 +1894,29 @@ static void init_tio(struct dm_rq_target_io *tio, struct request *rq, init_kthread_work(&tio->work, map_tio_request); } -static struct dm_rq_target_io *prep_tio(struct request *rq, - struct mapped_device *md, gfp_t gfp_mask) +static struct dm_rq_target_io *dm_old_prep_tio(struct request *rq, + struct mapped_device *md, + gfp_t gfp_mask) { struct dm_rq_target_io *tio; int srcu_idx; struct dm_table *table; - tio = alloc_rq_tio(md, gfp_mask); + tio = alloc_old_rq_tio(md, gfp_mask); if (!tio) return NULL; init_tio(tio, rq, md); table = dm_get_live_table(md, &srcu_idx); + /* + * Must clone a request if this .request_fn DM device + * is stacked on .request_fn device(s). + */ if (!dm_table_mq_request_based(table)) { - if (!clone_rq(rq, md, tio, gfp_mask)) { + if (!clone_old_rq(rq, md, tio, gfp_mask)) { dm_put_live_table(md, srcu_idx); - free_rq_tio(tio); + free_old_rq_tio(tio); return NULL; } } @@ -1923,7 +1928,7 @@ static struct dm_rq_target_io *prep_tio(struct request *rq, /* * Called with the queue lock held. */ -static int dm_prep_fn(struct request_queue *q, struct request *rq) +static int dm_old_prep_fn(struct request_queue *q, struct request *rq) { struct mapped_device *md = q->queuedata; struct dm_rq_target_io *tio; @@ -1933,7 +1938,7 @@ static int dm_prep_fn(struct request_queue *q, struct request *rq) return BLKPREP_KILL; } - tio = prep_tio(rq, md, GFP_ATOMIC); + tio = dm_old_prep_tio(rq, md, GFP_ATOMIC); if (!tio) return BLKPREP_DEFER; @@ -2236,7 +2241,7 @@ static void dm_init_md_queue(struct mapped_device *md) md->queue->backing_dev_info.congested_data = md; } -static void dm_init_old_md_queue(struct mapped_device *md) +static void dm_init_normal_md_queue(struct mapped_device *md) { md->use_blk_mq = false; dm_init_md_queue(md); @@ -2503,7 +2508,7 @@ static struct dm_table *__bind(struct mapped_device *md, struct dm_table *t, * because request-based dm may be run just after the setting. */ if (dm_table_request_based(t)) { - stop_queue(q); + dm_stop_queue(q); /* * Leverage the fact that request-based DM targets are * immutable singletons and establish md->immutable_target @@ -2600,7 +2605,7 @@ struct queue_limits *dm_get_queue_limits(struct mapped_device *md) } EXPORT_SYMBOL_GPL(dm_get_queue_limits); -static void init_rq_based_worker_thread(struct mapped_device *md) +static void dm_old_init_rq_based_worker_thread(struct mapped_device *md) { /* Initialize the request-based DM worker thread */ init_kthread_worker(&md->kworker); @@ -2609,9 +2614,9 @@ static void init_rq_based_worker_thread(struct mapped_device *md) } /* - * Fully initialize a request-based queue (->elevator, ->request_fn, etc). + * Fully initialize a .request_fn request-based queue. */ -static int dm_init_request_based_queue(struct mapped_device *md) +static int dm_old_init_request_queue(struct mapped_device *md) { struct request_queue *q = NULL; @@ -2624,11 +2629,11 @@ static int dm_init_request_based_queue(struct mapped_device *md) md->seq_rq_merge_deadline_usecs = 0; md->queue = q; - dm_init_old_md_queue(md); + dm_init_normal_md_queue(md); blk_queue_softirq_done(md->queue, dm_softirq_done); - blk_queue_prep_rq(md->queue, dm_prep_fn); + blk_queue_prep_rq(md->queue, dm_old_prep_fn); - init_rq_based_worker_thread(md); + dm_old_init_rq_based_worker_thread(md); elv_register_queue(md->queue); @@ -2699,9 +2704,8 @@ static struct blk_mq_ops dm_mq_ops = { .init_request = dm_mq_init_request, }; -static int dm_init_request_based_blk_mq_queue(struct mapped_device *md) +static int dm_mq_init_request_queue(struct mapped_device *md) { - unsigned md_type = dm_get_md_type(md); struct request_queue *q; int err; @@ -2766,21 +2770,21 @@ int dm_setup_md_queue(struct mapped_device *md) switch (md_type) { case DM_TYPE_REQUEST_BASED: - r = dm_init_request_based_queue(md); + r = dm_old_init_request_queue(md); if (r) { - DMWARN("Cannot initialize queue for request-based mapped device"); + DMERR("Cannot initialize queue for request-based mapped device"); return r; } break; case DM_TYPE_MQ_REQUEST_BASED: - r = dm_init_request_based_blk_mq_queue(md); + r = dm_mq_init_request_queue(md); if (r) { - DMWARN("Cannot initialize queue for request-based blk-mq mapped device"); + DMERR("Cannot initialize queue for request-based dm-mq mapped device"); return r; } break; case DM_TYPE_BIO_BASED: - dm_init_old_md_queue(md); + dm_init_normal_md_queue(md); blk_queue_make_request(md->queue, dm_make_request); /* * DM handles splitting bios as needed. Free the bio_split bioset @@ -3123,7 +3127,7 @@ static int __dm_suspend(struct mapped_device *md, struct dm_table *map, * dm defers requests to md->wq from md->queue. */ if (dm_request_based(md)) { - stop_queue(md->queue); + dm_stop_queue(md->queue); if (md->kworker_task) flush_kthread_worker(&md->kworker); } @@ -3147,7 +3151,7 @@ static int __dm_suspend(struct mapped_device *md, struct dm_table *map, dm_queue_flush(md); if (dm_request_based(md)) - start_queue(md->queue); + dm_start_queue(md->queue); unlock_fs(md); dm_table_presuspend_undo_targets(map); @@ -3226,7 +3230,7 @@ static int __dm_resume(struct mapped_device *md, struct dm_table *map) * Request-based dm is queueing the deferred I/Os in its request_queue. */ if (dm_request_based(md)) - start_queue(md->queue); + dm_start_queue(md->queue); unlock_fs(md); -- cgit v1.2.3-55-g7522