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 c125311d96b1
("blk-wbt: don't maintain inflight counts if disabled").
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Nilay Shroff <nilay@xxxxxxxxxxxxx>
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
Changes compared to v1: rebased on top of Jen's for-next branch.
block/blk-sysfs.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/block/blk-sysfs.c b/block/blk-sysfs.c
index 4a7f1a349998..c94b8b6ab024 100644
--- a/block/blk-sysfs.c
+++ b/block/blk-sysfs.c
@@ -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);
