On Tue, 2017-05-02 at 09:25 -0600, Jens Axboe wrote: > On 05/02/2017 09:16 AM, Christoph Hellwig wrote: > > Any reason for the move from ->end_io_data to ->special? I thought > > that ->special was something we'd get rid of sooner or later now > > that we can have additional per-cmd data even for !mq. > > With the switch to blk_execute_rq(), we can't be using end_io_data > and end_io, as we use that internally for the wakeup. So I have to > stuff it somewhere. > > The obvious option would be to move it to mtip_cmd, but we can't > safely access that prior to having a driver tag assigned, which doesn't > happen until we end up in our ->queue_rq(). So we need to stuff it > somewhere. Hello Jens, Do you think it would be a good idea to allow blk_get_request() callers to specify that a driver tag has to be allocated even if a scheduler has been configured? That would make it possible to store completion data in mtip_cmd for the mtip driver. Thanks, Bart.
