Re: [PATCH 01/19] dax: remove block device dependencies

From: Dan Williams
Date: Tue Jan 07 2020 - 18:39:07 EST


On Tue, Jan 7, 2020 at 11:46 AM Dan Williams <dan.j.williams@xxxxxxxxx> wrote:
[..]
> > I'd say deprecate the
> > kernel automounting partitions, but I guess it already does that, and
>
> Ok, now I don't know why automounting is leaking into this discussion?
>
> > removing it would break /something/.
>
> Yes, the breakage risk is anyone that was using ext4 mount failure as
> a dax capability detector.
>
> > I guess you could put
> > "/dev/pmemXpY" on the deprecation schedule.
>
> ...but why deprecate /dev/pmemXpY partitions altogether? If someone
> doesn't care about dax then they can do all the legacy block things.
> If they do care about dax then work with whole device namespaces.

Circling back on this point now that I understand what you meant by
automount. It would need to be a full deprecation of /dev/pmemXpY
devices if kpartx dax support is going to fully take over for people
that want to use disk partition tables instead of EFI Namespace Labels
to carve up pmem.