[PATCH] nvme-core: update NS Attr Changed AEN handling for ANA group

[Keith Busch]

On Tue, Dec 08, 2020 at 07:13:00PM +0000, Knight, Frederick wrote:
> Setting up a new ANA Group does NOT cause a transition from <UNKNOWN state> to <some known state>.  The establishment of initial state is NOT a change of state as defined in section 8.20.3.6.
> 
> An ANA AEN is prohibited if the ANA change is due to the creation of a namespace.

Yes, the AEN is prohibited if the ANA change is due to the creation of a
namespace. In this scenario, though, the ANA change is due to a group
entering a state, and you're required to notify that as long as ANA
events are enabled. There is no text in section 8.20.3.6 or anywhere
else that I can find that says creating a group with a valid state
disqualifies it as "entering" that state. However, I do find that
section 8.20.3.5 says transitions may occur from states not visible to
the host, so <UNKNOWN state> to <known state> is a transition according
to the spec.