Re: Displaying streams as xattrs

From: "Björn JACKE" <bj@SerNet.DE>
To: Jeremy Allison <jra@samba.org>
Cc: Steve French <smfrench@gmail.com>,
	CIFS <linux-cifs@vger.kernel.org>,
	samba-technical <samba-technical@lists.samba.org>
Subject: Re: Displaying streams as xattrs
Date: Thu, 25 May 2023 11:39:00 +0200	[thread overview]
Message-ID: <20230525093900.GA261009@sernet.de> (raw)
In-Reply-To: <ZGuWhzP98U9Niog+@jeremy-rocky-laptop>

On 2023-05-22 at 09:21 -0700 Jeremy Allison via samba-technical sent off:
> On Mon, May 22, 2023 at 01:39:50AM -0500, Steve French wrote:
> > On Sun, May 21, 2023 at 11:33 PM ronnie sahlberg
> > <ronniesahlberg@gmail.com> wrote:
> > > 
> > > A problem  we have with xattrs today is that we use EAs and these are
> > > case insensitive.
> > > Even worse I think windows may also convert the names to uppercase :-(
> > > And there is no way to change it in the registry :-(
> > 
> > But for alternate data streams if we allowed them to be retrieved via xattrs,
> > would case sensitivity matter?  Alternate data streams IIRC are already
> > case preserving.   Presumably the more common case is for a Linux user
> > to read (or backup) an existing alternate data stream (which are usually
> > created by Windows so case sensitivity would not be relevant).
> 
> Warning Will Robinson ! Mixing ADS and xattrs on the client side is a receipe for
> confusion and disaster IMHO.
> 
> They really are different things. No good will come of trying to mix
> the two into one client namespace.
> 

just took a look at how the ntfs-3g module is handling this. It was an option
streams_interface=value, which allows "windows", which means that the
alternative data streams are accessable as-is like in Windows, with ":" being
the separator. This might be a nice option for cifsfs also. That option would
just be usable if no posix extensions are enabled of course.

Björn