On 7/7/20 9:04 AM, Mike Snitzer wrote: > From: Ming Lei <ming.lei@xxxxxxxxxx> > > dm-multipath is the only user of blk_mq_queue_inflight(). When > dm-multipath calls blk_mq_queue_inflight() to check if it has > outstanding IO it can get a false negative. The reason for this is > blk_mq_rq_inflight() doesn't consider requests that are no longer > MQ_RQ_IN_FLIGHT but that are now MQ_RQ_COMPLETE (->complete isn't > called or finished yet) as "inflight". > > This causes request-based dm-multipath's dm_wait_for_completion() to > return before all outstanding dm-multipath requests have actually > completed. This breaks DM multipath's suspend functionality because > blk-mq requests complete after DM's suspend has finished -- which > shouldn't happen. > > Fix this by considering any request not in the MQ_RQ_IDLE state > (so either MQ_RQ_COMPLETE or MQ_RQ_IN_FLIGHT) as "inflight" in > blk_mq_rq_inflight(). Applied, thanks. -- Jens Axboe
