[PATCH 3/3] nvme: make SG_IO support optional

[Christoph Hellwig]

On Thu, Dec 24, 2015 at 03:29:46PM +0000, Keith Busch wrote:
> On Thu, Dec 24, 2015 at 12:40:40PM +0100, Christoph Hellwig wrote:
> > On Thu, Dec 24, 2015 at 01:31:32PM +0200, Sagi Grimberg wrote:
> > > OK, I see what you mean. We can look at having multipathd ioctl'ing
> > > identify_ns at some point...
> > 
> > block/for-next has the nguid available as a sysfs attribute, that's
> > all we should need.
> 
> Off the top of your head, do you happen to know how to point multipathd
> to the new attribute? Is this a code change or just a configuration rule?

With the most recent mutlipath-tools there should be no need to patch
mutipath-tools.  Just make sure udev sets the ID_SERIAL attribute
correctly, which I think some folks were already looking into.  An
explicit getuid callout that just reads the file should also work
with any versions, although the most recent ones call it deprectated.