[PATCH] block, nvme: export and use passthrough stats

[Christoph Hellwig]

On Mon, May 25, 2026 at 09:32:19AM +0200, Christoph Hellwig wrote:
> On Fri, May 22, 2026 at 08:15:37AM -0700, Keith Busch wrote:
> > From: Keith Busch <kbusch at kernel.org>
> > 
> > So stacking drivers can also report passthrough workloads through
> > iostat.
> 
> Except that this patch also wires it up in nvme.  So please split
> it and write proper commit messages for both parts.

.. and while we're at it - it actually is called from the lower nvme
drivers, just conditional on being a mpath request.  So this is
in many ways a bit weird, and the comments / commit logs should
probably explain it a bit.