Commit 60a9bb90 authored by Ye Bin's avatar Ye Bin Committed by Jens Axboe
Browse files

blktrace: introduce 'blk_trace_{start,stop}' helper 



Introduce 'blk_trace_{start,stop}' helper. No functional changed.

Signed-off-by: default avatarYe Bin <yebin10@huawei.com>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Link: https://lore.kernel.org/r/20221019033602.752383-2-yebin@huaweicloud.com


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent d4347d50

kernel/trace/blktrace.c

+36 −38
Original line number Diff line number Diff line
@@ -346,6 +346,37 @@ static void put_probe_ref(void) 
	mutex_unlock(&blk_probe_mutex);

}



static int blk_trace_start(struct blk_trace *bt)

{

	if (bt->trace_state != Blktrace_setup &&

	    bt->trace_state != Blktrace_stopped)

		return -EINVAL;



	blktrace_seq++;

	smp_mb();

	bt->trace_state = Blktrace_running;

	raw_spin_lock_irq(&running_trace_lock);

	list_add(&bt->running_list, &running_trace_list);

	raw_spin_unlock_irq(&running_trace_lock);

	trace_note_time(bt);



	return 0;

}



static int blk_trace_stop(struct blk_trace *bt)

{

	if (bt->trace_state != Blktrace_running)

		return -EINVAL;



	bt->trace_state = Blktrace_stopped;

	raw_spin_lock_irq(&running_trace_lock);

	list_del_init(&bt->running_list);

	raw_spin_unlock_irq(&running_trace_lock);

	relay_flush(bt->rchan);



	return 0;

}



static void blk_trace_cleanup(struct request_queue *q, struct blk_trace *bt)

{

	synchronize_rcu();
@@ -658,7 +689,6 @@ static int compat_blk_trace_setup(struct request_queue *q, char *name, 


static int __blk_trace_startstop(struct request_queue *q, int start)

{

	int ret;

	struct blk_trace *bt;



	bt = rcu_dereference_protected(q->blk_trace,
@@ -666,36 +696,10 @@ static int __blk_trace_startstop(struct request_queue *q, int start) 
	if (bt == NULL)

		return -EINVAL;



	/*

	 * For starting a trace, we can transition from a setup or stopped

	 * trace. For stopping a trace, the state must be running

	 */

	ret = -EINVAL;

	if (start) {

		if (bt->trace_state == Blktrace_setup ||

		    bt->trace_state == Blktrace_stopped) {

			blktrace_seq++;

			smp_mb();

			bt->trace_state = Blktrace_running;

			raw_spin_lock_irq(&running_trace_lock);

			list_add(&bt->running_list, &running_trace_list);

			raw_spin_unlock_irq(&running_trace_lock);



			trace_note_time(bt);

			ret = 0;

		}

	} else {

		if (bt->trace_state == Blktrace_running) {

			bt->trace_state = Blktrace_stopped;

			raw_spin_lock_irq(&running_trace_lock);

			list_del_init(&bt->running_list);

			raw_spin_unlock_irq(&running_trace_lock);

			relay_flush(bt->rchan);

			ret = 0;

		}

	}



	return ret;

	if (start)

		return blk_trace_start(bt);

	else

		return blk_trace_stop(bt);

}



int blk_trace_startstop(struct request_queue *q, int start)
@@ -1614,13 +1618,7 @@ static int blk_trace_remove_queue(struct request_queue *q) 
	if (bt == NULL)

		return -EINVAL;



	if (bt->trace_state == Blktrace_running) {

		bt->trace_state = Blktrace_stopped;

		raw_spin_lock_irq(&running_trace_lock);

		list_del_init(&bt->running_list);

		raw_spin_unlock_irq(&running_trace_lock);

		relay_flush(bt->rchan);

	}

	blk_trace_stop(bt);



	put_probe_ref();

	synchronize_rcu();