race between nvme device creation and discovery?

[Daniel Wagner]

> > We have a 'state' attribute in sysfs already, though the
> > NVME_CTRL_STARTED_ONCE is modelled as flag. Not sure how this fits
> > together yet, so let me play with this.
> 
> If I got this right, we could just filter out all controllers which are
> in the NEW state, because all transports trigger the connect code right
> after the NEW state. At this point the sysfs should be completely
> populated.

I've patched libnvme to print the state of the controller right
before the lookup for the subsystem happens and it says:

    +state connecting
    +failed to lookup subsystem for controller nvme1

more digging needed...