As per subject really!
On my old PC I had CIFS entries in fstab and scripts in /etc/network/if-up.d and if-down.d, and whilst the mount worked well the unmount usually locked the PC on shutdown (SysRq-B was about the only thing it would respond to).
I now have a new PC so I want to set this up correctly. All I want is that when eth0 comes up, several Samba shares are mounted, and before eth0 goes down they are unmounted (forcibly if necessary).
I've looked at upstart as a possibility but I don't see how to run a script before networking goes down, unless I edit the relevant network script (I don't want to change system scripts).
In case I'm overcomplicating this, all I really want is a handful of shares to be available whenever the network is, and for them not to cause me problems if I restart or shutdown networking.
I'm using Kubuntu 12.10