[PATCH] nvmet: per-host namespaces masking

[Christoph Hellwig]

On Fri, Feb 05, 2021 at 10:38:41AM +0100, Hannes Reinecke wrote:
> On 2/5/21 10:32 AM, Christoph Hellwig wrote:
>> On Fri, Feb 05, 2021 at 10:29:26AM +0100, Hannes Reinecke wrote:
>>> Implement per-host namespaces masking, allowing to expose
>>> different namespaces to different hosts connecting to the
>>> same subsystem.
>>> The original method of adding host nqns to the subsystem
>>> takes precedence over the per-host namespace masking.
>>
>> Why do you want to expose a single subsystem to multiple hosts?  This
>> creates all kinds of covert channels better avoided.
>>
> But the alternative is a subsystem per host.
> Which leads to a proliferation of subsystems on the target.

Yes, that was the choice we had in mind when writing the code.  The
subsystems are very cheap as they don't require any resources except
for some fairly small memory allocations.