Re: GDM failsafe session query

[Roger Burroughes <roger inf ed ac uk>]

On Sat, 1 May 2004, Telsa Gwynne wrote:

> Date: Sat, 1 May 2004 23:55:04 +0100
> From: Telsa Gwynne <hobbit aloss ukuu org uk>
> To: gnome-list gnome org
> Subject: Re: GDM failsafe session query
> 
> On Thu, Apr 29, 2004 at 10:16:01AM +0100 or thereabouts, 
> Roger Burroughes wrote: 
> 
> > 	I have a question about failsafe sessions when a user's home
> > directory isn't available (for whatever reason)...
> > 
> > 	When a user starts logging-in via GDM using the standard
> > greeter (and assuming there is no home directory available for this
> > user - everything works OK when it IS available), a warning message is
> > displayed:
> > 
> >    "Your home directory is listed as:
> >     '/home/infteach'
> >     but it does not appear to exist.
> >     Do you want to log in with the root
> >     directory as your home directory?
> > 
> >     It is unlikely anything else will work unless
> >     you use a failsafe session"
> > 
> > 	(This message is displayed even when a failsafe session is
> > explicitly selected from the "Session" menu.) 
> 
> This suggestion came from someone else. Pardon me if it is not too 
> coherent :) 
> 
> If there is no home directory, it can't write to the home 
> directory. (Well, yes...) If it can't write to the home directory, 
> it can't write the .Xauthority file. Is that .Xauthority file 
> needed for applications to run?
> 
> The person who mentioned this thinks it might be. 
> It might explain this, at least: 
> 
> > it's not even trying to run /etc/X11/gdm/Xsession (no
> > /tmp/xses-infteach is created).

	Many thanks for the feedback (and the only response so far!).

	Given that it IS possible to log in via other methods (ssh,
for example - which complains "/usr/bin/X11/xauth: error in locking
authority file /home/infteach/.Xauthority", but does succeed), and
then run something like /usr/X11R6/bin/xterm without error, I'm
guessing that the lack of a .Xauthority file isn't a showstopper (but
I'm willing to be proved wrong :-).

	It would also appear that /etc/X11/gdm/Xsession assumes that
the home directory MIGHT not be available, since it redirects errors
to /tmp/xses-$USER if ~/.xsession-errors isn't available (although I
suppose this could just be for non-writability or some other error,
rather than complete a absence of home directory) - but in this case
it isn't even getting the chance to check...

	BTW, if anyone knows of any documentation that explains
the components/programs invoked as part of the GDM login process,
pointers would be appreciated...


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Roger Burroughes				| University of Edinburgh
Phone:	+44 (0)131 650 4447                     | School of Informatics
Fax:	+44 (0)131 650 4587			| 2 Buccleuch Place
Email:  R Burroughes ed ac uk                   | Edinburgh EH8 9LW Scotland
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