[PATCH 8/9] nvme: implement multipath access to nvme subsystems

[Hannes Reinecke]

On 09/25/2017 03:50 PM, Christoph Hellwig wrote:
> On Mon, Sep 25, 2017 at 03:47:43PM +0200, Hannes Reinecke wrote:
>> Can't we make the multipath support invisible to the host?
>> IE check the shared namespaces before creating the device node, and just
>> move them under the existing namespaces if one exists?
> 
> That was what my first version did, but various people talked me
> out of it.  Unfortunately just multiplexing breaks a few things,
> including the userspace passthrough ioctls.
> 
Care to give some specifics?
How would userspace passthrough be affected?
I would've thought that we're sending the ioctl down one path, and we'd
be getting the completion back on the same path/queue/whatever.
(Unless we're talking multi-command ioctls, but those are evil anyway)

Cheers,

Hannes
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