Re: Versioning file system

[Kyle Moffett]

On Jun 18, 2007, at 17:24:23, Brad Boyer wrote:
> On Tue, Jun 19, 2007 at 12:26:57AM +0200, Jörn Engel wrote:
> > Pointless here means that _I_ don't see the point.  Maybe there  
> > are valid uses for extended attributes.  If there are, noone has  
> > explained them to me yet.
>
> The users of extended attributes that I've dealt with are ACL  
> support and SELinux. These both use extended attributes under the  
> covers. It's just not immediately obvious if you aren't looking.

Yeah, extended attributes are typically used for exactly that:  
"attributes" like labels, permissions, encoding, cached file-type,  
DOS/Windows/Mac metadata, etc.  Sometimes people suggest sticking  
icons in there, but that's probably a bad idea.  At most stick an  
"icon label" attribute which refers to a file "/usr/share/icons/ 
by_attr/$ICON_LABEL.png".  If you're trying to put more than 256  
bytes of data in an extended attribute then you're probably doing  
something wrong.  They're very good for cached attributes (like file- 
type) where you don't care if the data is lost by "tar", and they're  
reasonable for security-related attributes where you don't want  
attribute-unaware programs trying to save and restore them (like  
SELinux labels).

Cheers,
Kyle Moffett

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