[PATCH] nvme: make controller 'state' sysfs attribute pollable

[Christoph Hellwig]

On Mon, Sep 25, 2017 at 10:23:16AM +0200, Hannes Reinecke wrote:
> > We could have such an interface I assume. But it would suck to maintain
> > yet another state (we are already having enough trouble to have a
> > coherent controller state machine).
> 
> Weell ... we could be using a notifier chain for that.
> I think I should post my patchset.

The point is: if you want proper multipath behavior use the nvme
in-kernel multipath code.  If you want to weird crap in userspace don't
expect any help from the kernel driver.