Re: new version of glibc xattr patch

[Michael Banck]

On Mon, Feb 20, 2006 at 02:15:48PM -0800, Roland McGrath wrote:
> >       if (value != NULL && bufsz > *size)
> >         return ERANGE;
> >       *size = bufsz;
> 
> That fix leaks in the ERANGE case.  I did a different fix.
> Please verify it.

It works just as fine.
 
> > Our tests seemed to have shown that most (all?) passive translators do
> > not have the S_IPTRANS stat bit set, thus not reporting the
> > gnu.translator xattr through listxattr.  Are we missing something here?
> 
> I doubt this is true.  If it is, it's a server-side bug.  Note that
> S_IPTRANS and the gnu.translator xattr are found on nodes opened with
> O_NOTRANS.  They will more or less never be seen by the file name-based
> calls, only by f*xattr on an fd opened using O_NOTRANS.  

I see.  This means existing code will need to get changed or rewritten I
guess.  Star and {get,set}fattr always use the file name-based calls,
which is why they do not report passive translators.  We could write a
{set,show}trans replacement for GNU/Linux perhaps, and add an option to
GNU tar to not follow translators (along with the other xattr support).
Star would be a bit more difficult to change, I couldn't get it to use
O_NOTRANS and f*xattr when I quickly tried, the build system breaks down
when _GNU_SOURCE is defined.


Michael