Re: [PATCH V5 00/12] Enable per-file/per-directory DAX operations V5

[Dan Williams]

On Tue, Mar 10, 2020 at 11:44 PM Christoph Hellwig <hch@xxxxxx> wrote:
>
> On Wed, Mar 11, 2020 at 05:39:42PM +1100, Dave Chinner wrote:
> > IOWs, the dax_associate_page() related functionality probably needs
> > to be a filesystem callout - part of the aops vector, I think, so
> > that device dax can still use it. That way XFS can go it's own way,
> > while ext4 and device dax can continue to use the existing mechanism
> > mechanisn that is currently implemented....
>
> s/XFS/XFS with rmap/, as most XFS file systems currently don't have
> that enabled we'll also need to keep the legacy path around.

Agree, it needs to be an opt-in capability as ext4 and xfs w/o rmap
will stay on the legacy path for the foreseeable future.