On Thu, May 12, 2022 at 10:09:12AM +0200, Christoph Hellwig wrote: > On Thu, May 12, 2022 at 01:25:24PM +0800, Ming Lei wrote: > > This way may cause nested plugging, and breaks xfstests generic/131. > > Also may cause io hang since request can't be polled before flushing > > plug in blk_execute_rq(). > > Looking at this again, yes blk_mq_request_bypass_insert is probably the > wrong place. > > > I'd suggest to apply the plug in blk_execute_rq_nowait(), such as: > > Do we really need the use_plug parameter and the extra helper? If > someone holds a plug over passthrough command submission I think > we can assume they actually do want to use it. Otherwise this does > indeed look like the better plan. use_plug is just for avoiding hang in blk_rq_poll_completion(), so I think we can bypass plug if one polled rq is executed inside blk_execute_rq(). Thanks, Ming
