Re: concurrent X users and gnome-volume-manager
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".
> > > >
> > > > You are in a situation where g-v-m just won't work. By automatically
> > > > mounting a device the first user that mounts the device "owns" it,
> > > > i.e. only this user and root can unmount this device (it's what the
> > > > "user" option does)
> > >
> > > 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...
>
> For the mount stuff, we are using pmount to dictate mount policy. Not mount
> options in fstab.
Ok, but the mount option are passed down by pmount itself, so the modification
can be done there, can it not ? And if pmount uses user,uid=<active uid>, we
could do the same with users,gid=<group of remote stuff users>.
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.
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. 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.
But there are other possibilities as well :
4) Once X/linux support real dual-seat, there will be two possible users
using the machine at the same time, who will hold the right to the USB stick
then ?
5) What about remote X sessions ? I suppose this is already taken care on by
making sure the user who has the right to the box is at the console.
6) What about users logged in through a serial console or whatever, and
using the machine at the same time in non-graphical mode ?
Friendly,
Sven Luther
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