encrypted root initialisation races/fails on hotplug devices (does not wait)

[Gaspar Sinai]

I installed ubuntu 8.0.4 to a USB flash drive. I have a volume group that contains encrypted root and swap logical volumes. On some machines the USB drive appears later than initramfs:/scripts/local-top/cryptroot enters /conf/conf.d/cryptroot.

As a hack I put in a 10 seconds delay:

*** scripts/local-top/cryptroot- 2008-07-09 00:26:36.000000000 +0900
--- scripts/local-top/cryptroot 2008-07-09 00:27:14.000000000 +0900
***************
*** 271,274 ****
--- 271,275 ----
  # Do we have any settings from the /conf/conf.d/cryptroot file?
  if [ -r /conf/conf.d/cryptroot ]; then
+ sleep 10
        while read mapping; do
                setup_mapping "$mapping"

This is only temporary, a better solution could be to wait in activate_vg for the device to appear before setting up the volume group, just like https://launchpad.net/bugs/85640.

If you can provide a patch that is better than this I could try it out. I will be offline for 3 weeks.

[Gaspar Sinai (gazsi)]

After reading my report I noticed that I was not quite clear on how I set up the system.
Here is my /conf/conf.d/cryptroot in initramfs:

target=sdc5_crypt,source=/dev/disk/by-uuid/139c41d5-3699-4032-a827-3e9fc45aac7a,key=none,lvm=UUID=eecf28c6-9f0c-46f1-a8b4-14268677c4c4
target=sdc5_crypt,source=/dev/disk/by-uuid/139c41d5-3699-4032-a827-3e9fc45aac7a,key=none,lvm=gaspar-swap

/dev/disk/by-uuid/139c41d5-3699-4032-a827-3e9fc45aac7a is the disk that is slow to appear.

[ceg (ceg)]

IMHO the cryptsetup scripts in initramfs should go into a waiting loop (0.5 sec intervals) for their devices (going on quickly when device is available) and timeout after a while.

Lets get rid of long sleep workarounds and race conditions.

[ceg (ceg)]

Alternatively cryptsetup may be handled by udev rules, similar as md and lvm devices are.

[ceg (ceg)]

Just checked that the same applies for encrypted non-rootfilesystems on external disks, too. (/etc/init.d/cryptdisks*)

Since md and lvm devices are set up by udev, cryptdisks scripts need to contain a waiting loop for their disks, or need to be called by udev rules themselves.

[ceg (ceg)]

present in 9.10

[ceg (ceg)]

Current state of ubuntu systems with md raid: https://wiki.ubuntu.com/ReliableRaid