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.
Under this situation:
IMO, if this request has been handled by driver's irq handler, and if
driver's .timeout still returns BLK_EH_RESET_TIMER, it is driver's bug,
and the correct return value should be BLK_EH_HANDLED.
Is it possible to guarantee this efficiently if the irq handler
can run concurrently with the timeout handler?
