Hi Bart On 04/10/2018 09:34 AM, 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 Would you please detail more here about why the request could be completed twice ? Is it the scenario you described as below in https://marc.info/?l=linux-block&m=151796816127318 The following race can occur between the code that resets the timer and completion handling: - The code that handles BLK_EH_RESET_TIMER resets aborted_gstate. - A completion occurs and blk_mq_complete_request() calls __blk_mq_complete_request(). - The timeout code calls blk_add_timer() and that function sets the request deadline and adjusts the timer. - __blk_mq_complete_request() frees the request tag. - The timer fires and the timeout handler gets called for a freed request. If yes, how does the timeout handler get the freed request when the tag has been freed ? Thanks Jianchao