On 12/4/18 7:48 AM, Christoph Hellwig wrote: > On Fri, Nov 30, 2018 at 10:17:49AM -0700, Jens Axboe wrote: >>> Setting REQ_NOWAIT from inside the block layer will make the code that >>> submits requests harder to review. Have you considered to make this code >>> fail I/O if REQ_NOWAIT has not been set and to require that the context >>> that submits I/O sets REQ_NOWAIT? >> >> It's technically still feasible to do for sync polled IO, it's only >> the async case that makes it a potential deadlock. > > I wonder if we want a REQ_ASYNC_POLL compound flag #define that sets > REQ_POLL and REQ_NOWAIT to make this blindly obvious. Yeah that might make sense, all the async cases should certainly use it, and sync can keep using REQ_POLL. I'll add that and fold where I can. -- Jens Axboe
