remove ->rq_disk

[Christoph Hellwig]

On Tue, Sep 28, 2021 at 10:32:51PM +0800, Ming Lei wrote:
> Hello Christoph,
> 
> On Tue, Sep 28, 2021 at 07:22:06AM +0200, Christoph Hellwig wrote:
> > Hi Jens,
> > 
> > this series removes the rq_disk field in struct request, which isn't
> > needed now that we can get the disk from the request_queue.
> 
> Can we hold on this series until q->disk becomes really reliable[1][2]?

It's not like q->disk isn't reliable.  It is that we don't kill all bios
when tearing down the gendisk, which is an old problem that got worse.

That being said I'm resending this again.