[PATCH] NVMe: Use IDA for namespace disk naming

[Christoph Hellwig]

On Thu, Feb 18, 2016 at 11:18:05AM -0700, Keith Busch wrote:
> A namespace may be detached from a controller, but a user may be holding
> a reference to it. Attaching a new namespace with the same NSID will create
> duplicate names when using the NSID to name the disk.

This looks sensible, but I fear we might be running into the same
issue with the backing_device embedded in the request_queue.