From ab24f0129f680ecbdd62bca39b101eec03eb6038 Mon Sep 17 00:00:00 2001 From: Dave Reisner Date: Sat, 24 Mar 2012 18:39:17 -0400 Subject: shutdown: disassemble devices on shutdown sysfs contains enough information about block devices to be able to determine the order of stacked devices such as lvm, raid, or crypto. By looking at the device symlinks from the holders/ attributes of a block device, we can walk down each device chain until we reach the most descendant device. For each of these devices at the end of a chain, detect its type and perform the appropriate action to disassemble it. Then, walk back up the device chain, disassembling each parent device. To save ourselves some pain and make sure we're fairly accurate, lsblk is brought in for detection of device types. Thanks-To: Florian Pritz Thanks-To: Tom Gundersen Signed-off-by: Dave Reisner --- shutdown | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) (limited to 'shutdown') diff --git a/shutdown b/shutdown index aad0198..f664d6e 100755 --- a/shutdown +++ b/shutdown @@ -1,5 +1,59 @@ #!/usr/bin/ash +# teardown a single device by node name +# $1: device node name, e.g. md0, dm-2 +stop_device() { + local devtype= devname= + + # the device must still be active + [ -e "/sys/class/block/$1" ] || return 1 + + # this can sometimes fail on stopped md devices, when the + # sysfs node doesn't go away as quickly as i'd like it to. + devtype=$(lsblk -drno TYPE "/dev/$1" 2>/dev/null) || return 1 + case $devtype in + crypt) + read devname <"$1/dm/name" + cryptsetup luksClose "$devname" + ;; + dm|lvm) + # disassemble the parent VG + read devname <"$1/dm/name" + lvm lvdisplay -c "/dev/mapper/$devname" | { + IFS=: read _ vgname _ + lvm vgchange -an "$vgname" + } + ;; + raid*) + mdadm --stop "/dev/$1" + ;; + dmraid) + # XXX: i have no idea how dmraid works + dmraid -an + ;; + # silently ignore unstacked devices + esac +} + +# recursively disassemble a device chain +# $1: device node name, e.g. md0, dm-2 +disassemble() { + local holder= + + for holder in "$1"/holders/*; do + if [ ! -e "$holder" ]; then + # end of the chain, recurse back up + stop_device "$1" + return + fi + disassemble "${holder##*/}" + stop_device "$1" + done +} + +printf '%s\n' "Unmounting all devices." + +# unmount everything, but leave the API mounts findmnt -Rruno TARGET /oldroot | awk ' BEGIN { i = 0 } ! /^\/(proc|dev|sys)/ { @@ -15,6 +69,16 @@ END { umount -l "$mount" done +printf '%s\n' "Disassembling stacked devices." + +# chdir, so that we can avoid a lot of path chopping +cd /sys/class/block + +# iterate over devices with holders +for part in */holders/*; do + [ -e "$part" ] && disassemble "${part%%/*}" +done + case $1 in poweroff|shutdown|halt) "$1" -f -- cgit v1.2.3-24-g4f1b