On Sun, Apr 08, 2018 at 10:20:38PM -0700, Bart Van Assche wrote:
> If a completion occurs after blk_mq_rq_timed_out() has reset
> rq->aborted_gstate and the request is again in flight when the timeout
> expires then a request will be completed twice: a first time by the
> timeout handler and a second time when the regular completion occurs.
Are we still talking about the same BLK_EH_RESET_TIMER case? This can
be solved by the two patches which rcu-synchronizes the hand-over to
normal completion path, right?
> Additionally, the blk-mq timeout handling code ignores completions that
> occur after blk_mq_check_expired() has been called and before
> blk_mq_rq_timed_out() has reset rq->aborted_gstate. If a block driver
> timeout handler always returns BLK_EH_RESET_TIMER then the result will
> be that the request never terminates.
And this is the same race window which was always there, right? I
really don't think reducing or closing this window requires full