From 048c9374a749a27f16493cea033fa4a8ff492356 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Mon, 18 Apr 2011 09:52:22 +0200 Subject: block: Enhance new plugging support to support general callbacks md/raid requires an unplug callback, but as it does not uses requests the current code cannot provide one. So allow arbitrary callbacks to be attached to the blk_plug. Signed-off-by: NeilBrown Signed-off-by: Jens Axboe --- include/linux/blkdev.h | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index ec0357d8c4a5..f3f7879391a7 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -860,8 +860,13 @@ extern void blk_put_queue(struct request_queue *); struct blk_plug { unsigned long magic; struct list_head list; + struct list_head cb_list; unsigned int should_sort; }; +struct blk_plug_cb { + struct list_head list; + void (*callback)(struct blk_plug_cb *); +}; extern void blk_start_plug(struct blk_plug *); extern void blk_finish_plug(struct blk_plug *); @@ -887,7 +892,7 @@ static inline bool blk_needs_flush_plug(struct task_struct *tsk) { struct blk_plug *plug = tsk->plug; - return plug && !list_empty(&plug->list); + return plug && (!list_empty(&plug->list) || !list_empty(&plug->cb_list)); } /* -- cgit v1.2.3 From b4cb290e0a7d19235bd075c2ad4d60dbab0bac15 Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Mon, 18 Apr 2011 09:54:05 +0200 Subject: Revert "block: add callback function for unplug notification" MD can't use this since it really requires us to be able to keep more than a single piece of state for the unplug. Commit 048c9374 added the required support for MD, so get rid of this now unused code. This reverts commit f75664570d8b75469cc468f23c2b27220984983b. Conflicts: block/blk-core.c Signed-off-by: Jens Axboe --- block/blk-core.c | 3 --- block/blk-settings.c | 16 ---------------- include/linux/blkdev.h | 3 --- 3 files changed, 22 deletions(-) (limited to 'include/linux') diff --git a/block/blk-core.c b/block/blk-core.c index 77edf0512338..09b262811fff 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -2674,9 +2674,6 @@ static void queue_unplugged(struct request_queue *q, unsigned int depth, { trace_block_unplug(q, depth, !from_schedule); __blk_run_queue(q, from_schedule); - - if (q->unplugged_fn) - q->unplugged_fn(q); } static void flush_plug_callbacks(struct blk_plug *plug) diff --git a/block/blk-settings.c b/block/blk-settings.c index eb949045bb12..1fa769293597 100644 --- a/block/blk-settings.c +++ b/block/blk-settings.c @@ -790,22 +790,6 @@ void blk_queue_flush(struct request_queue *q, unsigned int flush) } EXPORT_SYMBOL_GPL(blk_queue_flush); -/** - * blk_queue_unplugged - register a callback for an unplug event - * @q: the request queue for the device - * @fn: the function to call - * - * Some stacked drivers may need to know when IO is dispatched on an - * unplug event. By registrering a callback here, they will be notified - * when someone flushes their on-stack queue plug. The function will be - * called with the queue lock held. - */ -void blk_queue_unplugged(struct request_queue *q, unplugged_fn *fn) -{ - q->unplugged_fn = fn; -} -EXPORT_SYMBOL(blk_queue_unplugged); - static int __init blk_settings_init(void) { blk_max_low_pfn = max_low_pfn - 1; diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index f3f7879391a7..3448d89297e8 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -196,7 +196,6 @@ typedef void (request_fn_proc) (struct request_queue *q); typedef int (make_request_fn) (struct request_queue *q, struct bio *bio); typedef int (prep_rq_fn) (struct request_queue *, struct request *); typedef void (unprep_rq_fn) (struct request_queue *, struct request *); -typedef void (unplugged_fn) (struct request_queue *); struct bio_vec; struct bvec_merge_data { @@ -284,7 +283,6 @@ struct request_queue rq_timed_out_fn *rq_timed_out_fn; dma_drain_needed_fn *dma_drain_needed; lld_busy_fn *lld_busy_fn; - unplugged_fn *unplugged_fn; /* * Dispatch queue sorting @@ -843,7 +841,6 @@ extern void blk_queue_dma_alignment(struct request_queue *, int); extern void blk_queue_update_dma_alignment(struct request_queue *, int); extern void blk_queue_softirq_done(struct request_queue *, softirq_done_fn *); extern void blk_queue_rq_timed_out(struct request_queue *, rq_timed_out_fn *); -extern void blk_queue_unplugged(struct request_queue *, unplugged_fn *); extern void blk_queue_rq_timeout(struct request_queue *, unsigned int); extern void blk_queue_flush(struct request_queue *q, unsigned int flush); extern struct backing_dev_info *blk_get_backing_dev_info(struct block_device *bdev); -- cgit v1.2.3 From af1db72d8b340f97ad12b60175afdef43e6f0e60 Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Mon, 18 Apr 2011 18:25:41 +1000 Subject: md/dm - remove remains of plug_fn callback. Now that unplugging is done differently, the unplug_fn callback is never called, so it can be completely discarded. Signed-off-by: NeilBrown --- drivers/md/dm-raid.c | 8 -------- include/linux/device-mapper.h | 1 - 2 files changed, 9 deletions(-) (limited to 'include/linux') diff --git a/drivers/md/dm-raid.c b/drivers/md/dm-raid.c index 5ef136cdba91..e5d8904fc8f6 100644 --- a/drivers/md/dm-raid.c +++ b/drivers/md/dm-raid.c @@ -390,13 +390,6 @@ static int raid_is_congested(struct dm_target_callbacks *cb, int bits) return md_raid5_congested(&rs->md, bits); } -static void raid_unplug(struct dm_target_callbacks *cb) -{ - struct raid_set *rs = container_of(cb, struct raid_set, callbacks); - - md_raid5_kick_device(rs->md.private); -} - /* * Construct a RAID4/5/6 mapping: * Args: @@ -487,7 +480,6 @@ static int raid_ctr(struct dm_target *ti, unsigned argc, char **argv) } rs->callbacks.congested_fn = raid_is_congested; - rs->callbacks.unplug_fn = raid_unplug; dm_table_add_target_callbacks(ti->table, &rs->callbacks); return 0; diff --git a/include/linux/device-mapper.h b/include/linux/device-mapper.h index e2768834f397..32a4423710f5 100644 --- a/include/linux/device-mapper.h +++ b/include/linux/device-mapper.h @@ -197,7 +197,6 @@ struct dm_target { struct dm_target_callbacks { struct list_head list; int (*congested_fn) (struct dm_target_callbacks *, int); - void (*unplug_fn)(struct dm_target_callbacks *); }; int dm_register_target(struct target_type *t); -- cgit v1.2.3 From 24ecfbe27f65563909b14492afda2f1c21f7c044 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Mon, 18 Apr 2011 11:41:33 +0200 Subject: block: add blk_run_queue_async Instead of overloading __blk_run_queue to force an offload to kblockd add a new blk_run_queue_async helper to do it explicitly. I've kept the blk_queue_stopped check for now, but I suspect it's not needed as the check we do when the workqueue items runs should be enough. Signed-off-by: Christoph Hellwig Signed-off-by: Jens Axboe --- block/blk-core.c | 36 ++++++++++++++++++++++++------------ block/blk-exec.c | 2 +- block/blk-flush.c | 4 ++-- block/blk.h | 1 + block/cfq-iosched.c | 6 +++--- block/elevator.c | 4 ++-- drivers/scsi/scsi_lib.c | 2 +- drivers/scsi/scsi_transport_fc.c | 2 +- include/linux/blkdev.h | 2 +- 9 files changed, 36 insertions(+), 23 deletions(-) (limited to 'include/linux') diff --git a/block/blk-core.c b/block/blk-core.c index e2bacfa46cc3..5fa3dd2705c6 100644 --- a/block/blk-core.c +++ b/block/blk-core.c @@ -204,7 +204,7 @@ static void blk_delay_work(struct work_struct *work) q = container_of(work, struct request_queue, delay_work.work); spin_lock_irq(q->queue_lock); - __blk_run_queue(q, false); + __blk_run_queue(q); spin_unlock_irq(q->queue_lock); } @@ -239,7 +239,7 @@ void blk_start_queue(struct request_queue *q) WARN_ON(!irqs_disabled()); queue_flag_clear(QUEUE_FLAG_STOPPED, q); - __blk_run_queue(q, false); + __blk_run_queue(q); } EXPORT_SYMBOL(blk_start_queue); @@ -296,11 +296,9 @@ EXPORT_SYMBOL(blk_sync_queue); * * Description: * See @blk_run_queue. This variant must be called with the queue lock - * held and interrupts disabled. If force_kblockd is true, then it is - * safe to call this without holding the queue lock. - * + * held and interrupts disabled. */ -void __blk_run_queue(struct request_queue *q, bool force_kblockd) +void __blk_run_queue(struct request_queue *q) { if (unlikely(blk_queue_stopped(q))) return; @@ -309,7 +307,7 @@ void __blk_run_queue(struct request_queue *q, bool force_kblockd) * Only recurse once to avoid overrunning the stack, let the unplug * handling reinvoke the handler shortly if we already got there. */ - if (!force_kblockd && !queue_flag_test_and_set(QUEUE_FLAG_REENTER, q)) { + if (!queue_flag_test_and_set(QUEUE_FLAG_REENTER, q)) { q->request_fn(q); queue_flag_clear(QUEUE_FLAG_REENTER, q); } else @@ -317,6 +315,20 @@ void __blk_run_queue(struct request_queue *q, bool force_kblockd) } EXPORT_SYMBOL(__blk_run_queue); +/** + * blk_run_queue_async - run a single device queue in workqueue context + * @q: The queue to run + * + * Description: + * Tells kblockd to perform the equivalent of @blk_run_queue on behalf + * of us. + */ +void blk_run_queue_async(struct request_queue *q) +{ + if (likely(!blk_queue_stopped(q))) + queue_delayed_work(kblockd_workqueue, &q->delay_work, 0); +} + /** * blk_run_queue - run a single device queue * @q: The queue to run @@ -330,7 +342,7 @@ void blk_run_queue(struct request_queue *q) unsigned long flags; spin_lock_irqsave(q->queue_lock, flags); - __blk_run_queue(q, false); + __blk_run_queue(q); spin_unlock_irqrestore(q->queue_lock, flags); } EXPORT_SYMBOL(blk_run_queue); @@ -979,7 +991,7 @@ void blk_insert_request(struct request_queue *q, struct request *rq, blk_queue_end_tag(q, rq); add_acct_request(q, rq, where); - __blk_run_queue(q, false); + __blk_run_queue(q); spin_unlock_irqrestore(q->queue_lock, flags); } EXPORT_SYMBOL(blk_insert_request); @@ -1323,7 +1335,7 @@ get_rq: } else { spin_lock_irq(q->queue_lock); add_acct_request(q, req, where); - __blk_run_queue(q, false); + __blk_run_queue(q); out_unlock: spin_unlock_irq(q->queue_lock); } @@ -2684,9 +2696,9 @@ static void queue_unplugged(struct request_queue *q, unsigned int depth, */ if (from_schedule) { spin_unlock(q->queue_lock); - __blk_run_queue(q, true); + blk_run_queue_async(q); } else { - __blk_run_queue(q, false); + __blk_run_queue(q); spin_unlock(q->queue_lock); } diff --git a/block/blk-exec.c b/block/blk-exec.c index 7482b7fa863b..81e31819a597 100644 --- a/block/blk-exec.c +++ b/block/blk-exec.c @@ -55,7 +55,7 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk, WARN_ON(irqs_disabled()); spin_lock_irq(q->queue_lock); __elv_add_request(q, rq, where); - __blk_run_queue(q, false); + __blk_run_queue(q); /* the queue is stopped so it won't be plugged+unplugged */ if (rq->cmd_type == REQ_TYPE_PM_RESUME) q->request_fn(q); diff --git a/block/blk-flush.c b/block/blk-flush.c index eba4a2790c6c..6c9b5e189e62 100644 --- a/block/blk-flush.c +++ b/block/blk-flush.c @@ -218,7 +218,7 @@ static void flush_end_io(struct request *flush_rq, int error) * request_fn may confuse the driver. Always use kblockd. */ if (queued) - __blk_run_queue(q, true); + blk_run_queue_async(q); } /** @@ -274,7 +274,7 @@ static void flush_data_end_io(struct request *rq, int error) * the comment in flush_end_io(). */ if (blk_flush_complete_seq(rq, REQ_FSEQ_DATA, error)) - __blk_run_queue(q, true); + blk_run_queue_async(q); } /** diff --git a/block/blk.h b/block/blk.h index 61263463e38e..c9df8fc3c999 100644 --- a/block/blk.h +++ b/block/blk.h @@ -22,6 +22,7 @@ void blk_rq_timed_out_timer(unsigned long data); void blk_delete_timer(struct request *); void blk_add_timer(struct request *); void __generic_unplug_device(struct request_queue *); +void blk_run_queue_async(struct request_queue *q); /* * Internal atomic flags for request handling diff --git a/block/cfq-iosched.c b/block/cfq-iosched.c index 3be881ec95ad..46b0a1d1d925 100644 --- a/block/cfq-iosched.c +++ b/block/cfq-iosched.c @@ -3368,7 +3368,7 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, cfqd->busy_queues > 1) { cfq_del_timer(cfqd, cfqq); cfq_clear_cfqq_wait_request(cfqq); - __blk_run_queue(cfqd->queue, false); + __blk_run_queue(cfqd->queue); } else { cfq_blkiocg_update_idle_time_stats( &cfqq->cfqg->blkg); @@ -3383,7 +3383,7 @@ cfq_rq_enqueued(struct cfq_data *cfqd, struct cfq_queue *cfqq, * this new queue is RT and the current one is BE */ cfq_preempt_queue(cfqd, cfqq); - __blk_run_queue(cfqd->queue, false); + __blk_run_queue(cfqd->queue); } } @@ -3743,7 +3743,7 @@ static void cfq_kick_queue(struct work_struct *work) struct request_queue *q = cfqd->queue; spin_lock_irq(q->queue_lock); - __blk_run_queue(cfqd->queue, false); + __blk_run_queue(cfqd->queue); spin_unlock_irq(q->queue_lock); } diff --git a/block/elevator.c b/block/elevator.c index 0cdb4e7ebab4..6f6abc08bb56 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -642,7 +642,7 @@ void elv_quiesce_start(struct request_queue *q) */ elv_drain_elevator(q); while (q->rq.elvpriv) { - __blk_run_queue(q, false); + __blk_run_queue(q); spin_unlock_irq(q->queue_lock); msleep(10); spin_lock_irq(q->queue_lock); @@ -695,7 +695,7 @@ void __elv_add_request(struct request_queue *q, struct request *rq, int where) * with anything. There's no point in delaying queue * processing. */ - __blk_run_queue(q, false); + __blk_run_queue(q); break; case ELEVATOR_INSERT_SORT_MERGE: diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 6d5c7ff43f5b..ab55c2fa7ce2 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -443,7 +443,7 @@ static void scsi_run_queue(struct request_queue *q) &sdev->request_queue->queue_flags); if (flagset) queue_flag_set(QUEUE_FLAG_REENTER, sdev->request_queue); - __blk_run_queue(sdev->request_queue, false); + __blk_run_queue(sdev->request_queue); if (flagset) queue_flag_clear(QUEUE_FLAG_REENTER, sdev->request_queue); spin_unlock(sdev->request_queue->queue_lock); diff --git a/drivers/scsi/scsi_transport_fc.c b/drivers/scsi/scsi_transport_fc.c index fdf3fa639056..28c33506e4ad 100644 --- a/drivers/scsi/scsi_transport_fc.c +++ b/drivers/scsi/scsi_transport_fc.c @@ -3829,7 +3829,7 @@ fc_bsg_goose_queue(struct fc_rport *rport) !test_bit(QUEUE_FLAG_REENTER, &rport->rqst_q->queue_flags); if (flagset) queue_flag_set(QUEUE_FLAG_REENTER, rport->rqst_q); - __blk_run_queue(rport->rqst_q, false); + __blk_run_queue(rport->rqst_q); if (flagset) queue_flag_clear(QUEUE_FLAG_REENTER, rport->rqst_q); spin_unlock_irqrestore(rport->rqst_q->queue_lock, flags); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 3448d89297e8..cbbfd98ad4a3 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -697,7 +697,7 @@ extern void blk_start_queue(struct request_queue *q); extern void blk_stop_queue(struct request_queue *q); extern void blk_sync_queue(struct request_queue *q); extern void __blk_stop_queue(struct request_queue *q); -extern void __blk_run_queue(struct request_queue *q, bool force_kblockd); +extern void __blk_run_queue(struct request_queue *q); extern void blk_run_queue(struct request_queue *); extern int blk_rq_map_user(struct request_queue *, struct request *, struct rq_map_data *, void __user *, unsigned long, -- cgit v1.2.3