Commit f5d10e69 authored by Bart Van Assche's avatar Bart Van Assche Committed by Jens Axboe
Browse files

block: Move a misplaced comment in queue_wb_lat_store() 



blk_mq_quiesce_queue() does not wait for pending I/O to finish. Freezing
a queue waits for pending I/O to finish. Hence move the comment that
refers to waiting for pending I/O above the call that freezes the
request queue. This patch moves this comment back to the position where
it was when this comment was introduced. See also commit c125311d
("blk-wbt: don't maintain inflight counts if disabled").

Cc: Christoph Hellwig <hch@lst.de>
Cc: Nilay Shroff <nilay@linux.ibm.com>
Signed-off-by: default avatarBart Van Assche <bvanassche@acm.org>
Reviewed-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Link: https://lore.kernel.org/r/20250825151424.1653910-1-bvanassche@acm.org


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 94ce5504

block/blk-sysfs.c

+5 −5
Original line number Diff line number Diff line
@@ -620,6 +620,11 @@ static ssize_t queue_wb_lat_store(struct gendisk *disk, const char *page, 
	if (val < -1)

		return -EINVAL;



	/*

	 * Ensure that the queue is idled, in case the latency update

	 * ends up either enabling or disabling wbt completely. We can't

	 * have IO inflight if that happens.

	 */

	memflags = blk_mq_freeze_queue(q);



	rqos = wbt_rq_qos(q);
@@ -638,11 +643,6 @@ static ssize_t queue_wb_lat_store(struct gendisk *disk, const char *page, 
	if (wbt_get_min_lat(q) == val)

		goto out;



	/*

	 * Ensure that the queue is idled, in case the latency update

	 * ends up either enabling or disabling wbt completely. We can't

	 * have IO inflight if that happens.

	 */

	blk_mq_quiesce_queue(q);



	mutex_lock(&disk->rqos_state_mutex);