[PATCH V2 2/3] blk-mq: retrieve bios before update nr_hw_queues

From: Jianchao Wang
Date: Wed Oct 17 2018 - 05:05:14 EST


retrieve bios of all requests on queue to drain requests, then
needn't depend on storage device to drain the queue any more.

Signed-off-by: Jianchao Wang <jianchao.w.wang@xxxxxxxxxx>
---
block/blk-mq.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index f75598b..6d89d3e 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -3085,7 +3085,10 @@ static void __blk_mq_update_nr_hw_queues(struct blk_mq_tag_set *set,
return;

list_for_each_entry(q, &set->tag_list, tag_set_list)
- blk_mq_freeze_queue(q);
+ blk_freeze_queue_start(q);
+
+ list_for_each_entry(q, &set->tag_list, tag_set_list)
+ blk_mq_sched_retrieve_bios(q);
/*
* Sync with blk_mq_queue_tag_busy_iter.
*/
--
2.7.4