[PATCH 1/1] nvme: don't ignore tagset allocation failures

[Sagi Grimberg]

> Not having a tagset doesn't mean we can't go live; it just means we can't
> do IO, but the admin handle is still up for device management.

So don't queue ns scanning...

> Also, nvme_queue_scan can be triggered from places outside nvme pci's control,
> so I think Max's patch is an appropriate place to check.

How is that not racy?