[dm-devel] multipath-tools: add ANA support for NVMe device

[Mike Snitzer]

On Wed, Nov 14 2018 at 10:35am -0500,
Christoph Hellwig <hch at lst.de> wrote:

> On Wed, Nov 14, 2018 at 08:24:05AM +0100, Hannes Reinecke wrote:
> > My argument here is that _ANA_ support should not be tied to the NVME 
> > native multipathing at all.
> 
> It should.  Because nvme driver multipathing is the only sanctioned
> way to use it.  All other ways aren't supported and might break at
> any time.

Quite a few of us who are multipath-tools oriented would like the proper
separation rather than your more pragmatic isolated approach.  And we'd
fix it if it broke in the future.

> > So personally I don't see why the 'raw' ANA support (parsing log pages, 
> > figuring out path states etc) needs to be tied in with native NVMe 
> > multipathing. _Especially_ not as my patch really is trivial.
> 
> And not actually usable for anything..  They only thing you do is to
> increase the code size for embedded nvme users that don't need any
> multipathing.

Isn't that why CONFIG_NVME_MULTIPATH exists?  Embedded nvme users
wouldn't set that.