On 2021/12/14 1:16, Christoph Hellwig wrote:
On Mon, Dec 13, 2021 at 12:09:07PM +0800, Laibin Qiu wrote:
Submit_bio
scsi_remove_device
sd_remove
del_gendisk
blk_unregister_queue
elv_unregister_queue
wbt_enable_default
<= Set rwb->enable_state (ON)
q_qos_track
<= rwb->enable_state (ON)
^^^^^^ this request will mark WBT_TRACKED without inflight add and will
lead to drop rqw->inflight to -1 in wbt_done() which will trigger IO hung.
Fix this by judge whether QUEUE_FLAG_REGISTERED is marked to distinguish
scsi remove scene.
Fixes: 76a8040817b4b ("blk-wbt: make sure throttle is enabled properly")
Signed-off-by: Laibin Qiu <qiulaibin@xxxxxxxxxx>
---
block/blk-wbt.c | 8 ++++----
1 file changed, 4 insertions(+), 4 deletions(-)
diff --git a/block/blk-wbt.c b/block/blk-wbt.c
index 3ed71b8da887..537f77bb1365 100644
--- a/block/blk-wbt.c
+++ b/block/blk-wbt.c
@@ -637,6 +637,10 @@ void wbt_enable_default(struct request_queue *q)
{
struct rq_qos *rqos = wbt_rq_qos(q);
+ /* Queue not registered? Maybe shutting down... */
+ if (!blk_queue_registered(q))
+ return;
Wouldn't it make more sense to simply not call wbt_enable_default from
elv_unregister_queue?
.
Refer to your opinion, I will post another version of V2.
Please take a look again.
