Re: Auto-unmounting secure partitions

["W. Michael Petullo" <mike@flyn.org>]

> > I've got a encrypted partition set up under /secure. I'd like the 
> > partition to be unmounted after no-ones used it for, say, 30 minutes. I'm 
> > guessing that there are already tools available to do this, so in order of 
> > preference, can people advise me
> 
> I've been thinking about this too. I think it would be better to have
> the screen lock do the umounting, for reasons which may become clear.
> 
> > - which fstab/mount option to use
> > - which command line tool to use
> > - which command line tool will tell me whether any process has a file open 
> > under /secure and/or /dev/hdb6 (so I can write a script to run under cron)
> 
> /sbin/fuser -m /secure will do the trick. What it will show, though, is
> that all sorts of things end up holding files and directories open more
> or less at random.
> 
> > - which API call to make in order to tell whether any process has a file 
> > open under /secure and/or /dev/hdb6 (so I can write an executable to run 
> > under cron)
> 
> For a workstation, I think it would be better that when the display is
> locked, the filesystem is umounted. I've even got some scripts that do
> it, except I don't know how to hook them into xscreensaver to make it do
> it.
> 
> fuser also takes a -k option to cause it to kill all the processes using
> the file(s), which I use before umounting.

I use my pam_mount modules to tie mounting and unmounting encrypted
filesystems to logging in and logging out.  XScreenSaver seems to support
PAM, so I guess it could be configured to use pam_mount to re-mount your
secure filesystem when you enter a password to unlock your screen.
Perhaps a hook could be added to XScreenSaver to unmount your filesystem
when the screensaver pops up.

Problem of open files remains, though.

Pam_mount is available at http://www.flyn.org.

-- 
Mike

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