RE: [RFC v2] Unicode/UTF-8 support for XFS

Zuckerman, Boris
2014-09-25T13:34:08Z

> -----Original Message-----
> From: linux-fsdevel-owner@vger.kernel.org [mailto:linux-fsdevel-
> owner@vger.kernel.org] On Behalf Of Dave Chinner
> Sent: Wednesday, September 24, 2014 7:10 PM
> To: Olaf Weber
> Cc: Ben Myers; linux-fsdevel@vger.kernel.org; tinguely@sgi.com; xfs@oss.sgi.com
> Subject: Re: [RFC v2] Unicode/UTF-8 support for XFS
>
> On Wed, Sep 24, 2014 at 03:21:04PM +0200, Olaf Weber wrote:
> > On 23-09-14 00:26, Dave Chinner wrote:
> > >On Thu, Sep 18, 2014 at 02:56:50PM -0500, Ben Myers wrote:
> >
> > [...]
> >
> > >>TODO: Store the unicode version number of the filesystem on disk in
> > >>the super block.
> > >
> > >So, if the filesystem has to store the specific unicode version it
> > >was created with so that we know what version to put in trie lookups,
> > >again I'll ask: why are we loading the trie as a generic kernel
> > >module and not as metadata in the filesystem that is demand paged and
> > >cached?
> >
> > This way the trie can be shared, and the code using it is not
> > entangled with the XFS code.
>
> The trie parsing code can still be common - just the location and contents of the data is
> determined by the end-user.
>

Both these approaches can co-exists (as I recall was done in Windows). A system may have "a default trie" and a caller (name space) can provide its own...