Re: [PATCH] blk-mq: start request gstate with gen 1

From: Jens Axboe
Date: Mon Apr 16 2018 - 23:56:31 EST


On 4/16/18 9:46 PM, Jianchao Wang wrote:
> rq->gstate and rq->aborted_gstate both are zero before rqs are
> allocated. If we have a small timeout, when the timer fires,
> there could be rqs that are never allocated, and also there could
> be rq that has been allocated but not initialized and started. At
> the moment, the rq->gstate and rq->aborted_gstate both are 0, thus
> the blk_mq_terminate_expired will identify the rq is timed out and
> invoke .timeout early.
>
> For scsi, this will cause scsi_times_out to be invoked before the
> scsi_cmnd is not initialized, scsi_cmnd->device is still NULL at
> the moment, then we will get crash.

Oops, this looks good to me. Applied.

--
Jens Axboe