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Subject: Re: silent semantic changes with reiser4
From: Nicholas Miell <nmiell@gmail.com>
To: Jamie Lokier <jamie@shareable.org>
Cc: Wichert Akkerman <wichert@wiggy.net>, Jeremy Allison <jra@samba.org>,
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On Wed, 2004-08-25 at 18:03, Jamie Lokier wrote:
> Nicholas Miell wrote:
> > Anything that currently stores a file's metadata in another file really
> > wants this right now. Things like image thumbnails, document summaries,
> > digital signatures, etc.
> 
> Additionally, all of those things you describe should be deleted if
> the file is modified -- to indicate that they're no longer valid and
> should be regenerated if needed.
> 
> Whereas there are some other kinds of metadata which should not be
> deleted if the file is modified.
> 
> -- Jamie

Presumably the app which uses the metadata will be smart enough to
compare the st_mtime of the MDS/stream/attribute/whatever (can we choose
a name for these things now?) to the st_mtime of the file and do the
right thing.

thumbnail - regenerate it
summary - keep it, it's relatively independent of the file's exact
contents
signature - always verify it
etc.