On Thu, Nov 18, 2021 at 11:30:41PM +0800, Ming Lei wrote: > We never insert flush request into scheduler queue before. > > Recently commit d92ca9d8348f ("blk-mq: don't handle non-flush requests in > blk_insert_flush") tries to handle FUA data request as normal request. > This way has caused warning[1] in mq-deadline dd_exit_sched() or io hang in > case of kyber since RQF_ELVPRIV isn't set for flush request, then > ->finish_request won't be called. > > Fix the issue by inserting FUA data request with blk_mq_request_bypass_insert() > when the device supports FUA, just like what we did before. How we did end up with REQ_ELV set for this request?