nvme multipath support V2

[Christoph Hellwig]

On Wed, Sep 20, 2017 at 01:09:59PM +0200, Johannes Thumshirn wrote:
> Using your patchset and doing the sanme double connect trick I get the same
> two block devices of cause.
> 
> How do I connect using both paths?

Same as above.  But now in addition to the /dev/nvmeXnY devices you
should also see a /dev/nvme/nsZ device.  The sysfs entry for it shows
which paths it belongs to.