Description:
The installation/upgrade script of udisks should kill the existing udisks daemon, otherwise the upgrade won't take effect until the next reboot. UDisks will start up by itself again and the user won't notice anything.

You also have to re-trigger all block devices in udev, to process any changed udev rules.

Here's the install script used in my AUR udisks entry... I also killed devkit-disks-daemon in case the user is upgrading from devkit-disks to udisks. I'm not entirely sure whether the D-Bus reload is necessary, but dbus didn't seem to reload /etc/dbus-1/system.d without it.

post_upgrade() {
if [ -f /var/run/dbus.pid ]; then
kill `pidof /usr/lib/devicekit-disks/devkit-disks-daemon` 2>/dev/null || true
kill `pidof /usr/lib/udisks/udisks-daemon` 2>/dev/null || true

/etc/rc.d/dbus reload

# we ship udev rules, so trigger an update
udevadm trigger --subsystem-match=block --action=change
fi
}

post_install() {
post_upgrade
}