Re: [PATCH 2/2] blk-mq: Fix request handover from timeout path to normal execution

From: Bart Van Assche
Date: Mon Apr 02 2018 - 18:49:57 EST

On Mon, 2018-04-02 at 15:16 -0700, tj@xxxxxxxxxx wrote:
> there's one non-critical race condition which has always been there.
> We have a larger race window for that case but don't yet know whether
> that's problematic or not. If that actually is problematic, we can
> figure out a way to solve that but such effort / added complexity
> doesn't seem justified yet. No?

Hello Tejun,

Some important block drivers systematically return BLK_EH_RESET_TIMER
from their timeout handler, e.g. the virtio-scsi initiator driver. What
will the consequence be for these drivers if a blk_mq_complete_request()
call is ignored? Will the request for which the completion was ignored
get stuck?