On Wed, Jan 26, 2022 at 06:50:03AM +0100, Christoph Hellwig wrote: > On Tue, Jan 25, 2022 at 05:09:42PM +0800, Ming Lei wrote: > > Follows another simple way by accounting all request with bio attached, > > except for requests with kernel buffer. > > > - else if (rq->q->disk) > > + else if (rq->q->disk && rq->bio) > > rq->part = rq->q->disk->part0; > > Most passthrough requests will have a bio, so you'll still use e.g. > the sd gendisk for sg request here. > > I think the right way would be to just remove this branch entirely. > This means we only account bios with a block_device, which implies > they have a gendisk. That will not account userspace IO, and people may complain. We can just account passthrough request from userspace by the patch in my last email. Thanks, Ming