Description of problem:

When a livecd-creator USB installation with overlay and encrypted home is halted or rebooted it hangs for 10-20 seconds _after_ plymouth has stopped throbbing, so it looks like the machine is dead. It could shutdown within seconds, so this unnecessary delay is a bug.

The problem is that /etc/init.d/halt loops and sleeps in the __umount* functions while it tries to unmount everything, finishing one device type at a time. That doesn't work in complex setups where there are circular dependencies between device types. For example: /home is ext3 on /dev/mapper/EncHome which is dm crypt on /dev/loop5 which is /mnt/live/LiveOS/home.img where /mnt/live is mounted from /dev/sdb1. So there is no way __umount_loop can unmount everything, and retrying and sleeping and killing won't help. Instead we must use several iterations over the different kinds of device types.

Live CDs could be perhaps be improved. The kickstarts creates a /etc/init.d/livesys which "mounts things" without handling how they should be unmounted again. Perhaps it should undo its own tricks on shutdown? It also seems like it was the intention that /etc/crypttab should be updated - but AFAICS that wouldn't help anyway. (CCing katzj)

The halt script seems to come in two parts; first a polite part (until quotaoff) where things are closed down nicely, and then a brutal part with unmounting and killing and sleeping. In the common case where polite unmounting works we would rather avoid killing and sleeping. I suggest adding a polite unmount section before the brutal one - or at least an easy way to insert custom actions there. It might take some time to do polite trial-and-error, but it is better and faster than killing and sleeping.

The current behaviour and code probably solves some other cases, so keeping it for failback would be fine.

The following works fine for me, inserted after quotaoff:

for dm in $(/sbin/dmsetup ls|cut -f1); do umount /dev/mapper/$dm; /sbin/cryptsetup remove $dm || /sbin/dmsetup remove $dm; done
for lo in $(/sbin/losetup -a|cut -d: -f1); do umount $lo; /sbin/losetup -d $lo; done
for mp in $(awk '{if(!/^\/proc /) {print $2}}' /proc/mounts |sort -r); do umount $mp; done

(stderr should probably be muted, and we might want to make it loop a couple of times to handle complex setups.)


Version-Release number of selected component (if applicable):

initscripts-8.95-1.i586
spin-kickstarts-0.11.4-1.fc11.noarch
livecd-tools-024-1.fc11.i586