Re: concurrent X users and gnome-volume-manager
On Sun, Dec 19, 2004 at 10:58:31AM +1100, Graham Williams wrote:
> Received Sun 19 Dec 2004 5:37am +1100 from Sven Luther:
> > On Sat, Dec 18, 2004 at 05:35:06PM +0100, Sjoerd Simons wrote:
> > > On Sat, Dec 18, 2004 at 05:32:26PM +0100, Sven Luther wrote:
> > > > On Sat, Dec 18, 2004 at 03:56:42PM +0000, Sam J wrote:
> > > > > Marcelo E. Magallon wrote:
> > > > > >On Sat, Dec 18, 2004 at 07:03:22AM +1100, Graham Williams wrote:
> > > > > >
> > > > > > > At any time on one machine (home machines running Debian unstable) I
> > > > > > > allow multiple users to have their X sessions running concurrently
> > > > > > > (e.g., on tty7, tty8, etc). I've not yet figured out how to get
> > > > > > > gnome-volume-manager working happily in this situation.
>
> > > > > > My initial reaction is "sorry, you loose".
>
> > > > > Could g-v-m be configured to use the "users" option instead of "user"?
> > > > > According to mount(8), it should allow any user to unmount the device
> > > > > regardless of who mounted it.
>
> > > > yes, but this alone will not do. you also need to make the files available, so
> > > > a group and the right gid options would be best in this circunstance.
>
> > > Please first define the behaviour you would like to see, before going into
> > > implementation details.. Do you want everyone to be able to umount all
> > > removable devices under all circumstances ? Or just in some cases or...
>
> [...]
>
> > Still, i understand that this is a maybe non-solveable usability issue. Let's
> > go into this in detail, as you asked.
> >
> > 1) There is one physical machine, where stuff can be plugged into.
> >
> > 2) This machine usually has only one user holding the console, so this user
> > is used by pmount, and everything works fine.
>
> I guess the "first" running g-v-m that notices the new device gets to
> assign its owner to the mounted device? (Each user may be running
> g-v-m and I'm guessing one of them notices the new device first?)
>
> > 3) In the case at hand, there are two X server running on the same machine
> > and the same console. They are not active at the same time, and it would
> > stand to reason that the expected behaviour would be for the user whose
> > session is actually active to mount the stuff. I don't know if this is
> > easily available as info though, but once you know this, the rest becomes
> > easy.
>
> Yes, if we could determine which of multiple X servers running on the
> current console was the active one when the device is plugged in that
> would be a start toward the solution. Another option is to open the
> device up to everyone in group plugdev through fstab (as below) but
> that is less than ideal:
>
> /dev/usbkey /media/usbkey auto users,gid=plugdev,umask=0002,defaults 0 0
>
> > Remaining problem is what to do about a plugged in USB stick, once you
> > switch over to the other console. One solution would be a console user
> > group, but again this poses security problems, altough rather limited ones.
>
> Would not the use of the "users" option in mount be a help to the
> solution here? The second user here just unmounts the device
Well, you also want to access the files, not only umount it, right ?
g-v-m/pmount/whatever also sets the uid of the mount to the first user running
it. So you need to do a gid=plugdev as you did above, but this means that any
user of the plugdev group may access the files.
Friendly,
Sven Luther
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