l*xattr functions (was: Re: VFS change needed for 4.1.0 and above.)

[Andrew Bartlett]

On Fri, 2013-05-10 at 20:47 -0700, Jeremy Allison wrote:
> In working with Steve French to define POSIX extended
> attribute support in Samba I've realized I'm going to have
> to add the following 4 functions to the Samba VFS (in
> master, i.e. 4.1.0).
> 
> lgetxattr
> lsetxattr
> lremovexattr
> llistxattr
> 
> Damn. This is my fault for not adding them in the
> first place :-(. 

Are you sure?  I thought I removed them for 4.0 as unused, eg:

commit 19eee33d82b4c1947b646241b6f22651abbce19d
Author: Andrew Bartlett <abartlet at samba.org>
Date:   Wed Apr 4 08:46:25 2012 +1000

    s3-vfs: Remove unused lremovexattr call from VFS modules, system.c
and configure
    
    If this is ever needed again, it would be more appropriate as an
options argument
    to removexattr.
    
    Andrew Bartlett

> I remember thinking about it but
> not doing so as we weren't using them and I didn't
> want to add non-used functions to the VFS definition.
> 
> This will definitely be a Samba 4.1.0 and above
> server change. I'll try and work this out next
> week whilst at SambaXP.
> 
> The good news is it will help me finally remove
> the broken semantics of dos_filemode (long story
> with a unsubmitted patch).

I'll be glad to review the patch, but do consider if it would be best as
an options argument, as some platforms use, rather than a distinct call
that needs to be implemented everywhere.  

(It was removed, from memory because extended attributes on links don't
exist on Linux, and my motivation would have been around avoiding having
to address emulating them in the xattr_tdb layer, for the as-then unused
codepaths. )

Andrew Bartlett

-- 
Andrew Bartlett                                http://samba.org/~abartlet/
Authentication Developer, Samba Team           http://samba.org