diff options
Diffstat (limited to 'scripts/casper')
| -rw-r--r-- | scripts/casper | 382 |
1 files changed, 382 insertions, 0 deletions
diff --git a/scripts/casper b/scripts/casper new file mode 100644 index 0000000..2557595 --- /dev/null +++ b/scripts/casper @@ -0,0 +1,382 @@ +#!/bin/sh + +# set -e + +mountpoint=/live_media +root_persistence="casper-rw" +home_persistence="home-rw" + +mkdir -p $mountpoint + +overlay_method=unionfs +if [ "${DPKG_ARCH}" = "ia64" ] || [ "${DPKG_ARCH}" = "hppa" ] || [ "${DPKG_ARCH}" = "sparc" ]; then + overlay_method=devmapper +fi + +USERNAME=debian +USERFULLNAME="Debian Live user" +HOST=debian + +[ -f /etc/casper.conf ] && . /etc/casper.conf + +export USERNAME USERFULLNAME HOST + +casper_path() { # Fixme: uglyness + path=$1 + if [ -e "$path/casper/filesystem.cloop" ]; then + echo "$path/casper/filesystem.cloop" + return 0 + elif [ -e "$path/casper/filesystem.squashfs" ]; then + echo "$path/casper/filesystem.squashfs" + return 0 + elif [ -e "$path/casper/filesystem.ext2" ]; then + echo "$path/casper/filesystem.ext2" + return 0 + elif [ -e "$path/casper/filesystem.xfs" ]; then + echo "$path/casper/filesystem.xfs" + return 0 + fi + return 1 +} + +subdevices() { + sysblock=$1 + r="" + for dev in "${sysblock}" "${sysblock}"/*; do + if [ -e "${dev}/dev" ]; then + r="${r} ${dev}" + fi + done + echo ${r} +} + +get_backing_device() { + case "$1" in + *.cloop) + echo $(setup_loop "$1" "cloop" "/sys/block/cloop*") + ;; + *.squashfs|*.ext2|*.xfs) + echo $(setup_loop "$1" "loop" "/sys/block/loop*") + ;; + *) + panic "Unrecognized casper filesystem: $1" + ;; + esac +} + +setup_cow() { + case "$1" in + unionfs) + setup_unionfs "$2" "$rootmnt" + ;; + devmapper) + setup_devmapper "$2" "$rootmnt" + esac +} + +sys2dev() { + sysdev=${1#/sys} + echo "/dev/$(udevinfo -q name -p ${sysdev} 2>/dev/null|| echo ${sysdev##*/})" +} + +setup_loop() { + local fspath=$1 + local module=$2 + local pattern=$3 + + modprobe -qb "$module" + if [ -x /sbin/udevplug ]; then + udevplug -W + else + udevtrigger + fi + + for loopdev in $pattern; do + if [ "$(cat $loopdev/size)" -eq 0 ]; then + dev=$(sys2dev "${loopdev}") + losetup "$dev" "$fspath" + echo "$dev" + return 0 + fi + done + panic "No loop devices available" +} + +get_fstype() { + local FSTYPE + local FSSIZE + eval $(fstype < $1) + if [ "$FSTYPE" != "unknown" ]; then + echo $FSTYPE + return 0 + fi + /lib/udev/vol_id -t $1 2>/dev/null +} + +setup_devmapper() { + backdev="$1" + rootmnt="$2" + + modprobe -qb dm-mod + COW_DEVICE=/dev/ram1 + COW_NAME="casper-cow" + + BACKING_FILE_SIZE=$(blockdev --getsize "$backdev") + MAX_COW_SIZE=$(blockdev --getsize "$COW_DEVICE") + CHUNK_SIZE=8 # sectors + + if [ -z "$COW_SIZE" -o "$COW_SIZE" -gt "$MAX_COW_SIZE" ]; then + COW_SIZE=$MAX_COW_SIZE + fi + + echo "0 $COW_SIZE linear $COW_DEVICE 0" | dmsetup create $COW_NAME + + echo "0 $BACKING_FILE_SIZE snapshot $backdev /dev/mapper/$COW_NAME p $CHUNK_SIZE" | \ + dmsetup create casper-snapshot + if [ "$(get_fstype $backdev)" = "unknown" ]; then + panic "Unknown file system type on $backdev" + fi + mount -t $(get_fstype "$backdev") /dev/mapper/casper-snapshot $rootmnt || panic "Can not mount /dev/mapper/casper/snapshot on $rootmnt" + + mkdir -p "$rootmnt/rofs" + echo "0 $BACKING_FILE_SIZE linear $backdev 0" | dmsetup create casper-backing + mount -t $(get_fstype "$backdev") /dev/mapper/casper-backing "$rootmnt/rofs" +} + +where_is_mounted() { + device=$1 + if grep -q "^$device " /proc/mounts; then + grep "^$device " /proc/mounts | read d mountpoint rest + echo $mountpoint + return 0 + fi + return 1 +} + +copy_to_ram() { + copyto="${mountpoint}_swap" + + size=$(du -ks ${mountpoint} | cut -f1) + size=$(expr ${size} + ${size}/20 ) # Fixme: 5% more to be sure + needed_space=$(expr ${size} * 1024) + freespace=$( expr $(awk '/MemFree/{print $2}' /proc/meminfo) + $( cat /proc/meminfo | grep Cached | head -n 1 | awk '/Cached/{print $2}' - )) + + if [ ! ${freespace} -lt ${needed_space} ] ; then + [ "$quiet" != "y" ] && log_begin_msg "Not enough free memory to copy to ram" + [ "$quiet" != "y" ] && log_end_msg + return + else + [ "$quiet" != "y" ] && log_begin_msg "Copying live media to ram..." + mkdir "${copyto}" + mount -t tmpfs -o size=${size}k /dev/shm ${copyto} + cp -a ${mountpoint}/* ${copyto} + umount ${mountpoint} + mount -r -o move ${copyto} ${mountpoint} + rmdir ${copyto} + [ "$quiet" != "y" ] && log_end_msg + fi +} + +find_cow_device() { + pers_label="${1}" + cow_backing="/${pers_label}-backing" + for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -v loop); do + for dev in $(subdevices "${sysblock}"); do + devname=$(sys2dev "${dev}") + if [ "$(/lib/udev/vol_id -l $devname 2>/dev/null)" = "${pers_label}" ]; then + echo "$devname" + return + elif [ "$(get_fstype ${devname})" = "vfat" ]; then + mkdir -p "${cow_backing}" + if where_is_mounted ${devname} > /dev/null; then + mount -o remount,rw ${devname} $(where_is_mounted ${devname}) || panic "Remounting failed" + mount -o bind $(where_is_mounted ${devname}) ${cow_backing} || panic "Cannot bind-mount" + else + mount -t $(get_fstype "${devname}") -o rw "${devname}" ${cow_backing} || panic "Cannot mount $devname on /cow-backing" + fi + + if [ -e "${cow_backing}/${pers_label}" ]; then + echo $(setup_loop "${cow_backing}/${pers_label}" "loop" "/sys/block/loop*") + return 0 + else + umount ${cow_backing} + fi + fi + done + done +} + +do_netmount() { + rofsmnt="$1" + # adapted from NFS filesystem mounting + + modprobe -q cifs + # For DHCP + modprobe -q af_packet + + ipconfig ${DEVICE} /tmp/net-${DEVICE}.conf + if [ "x${NFSROOT}" = "xauto" ]; then + NFSROOT=${ROOTSERVER}:${ROOTPATH} + fi + + NFSOPTS="-ouser=root,password=" + + [ "$quiet" != "y" ] && log_begin_msg "Mounting using mount.cifs with ${NFSROOT} ${rofsmnt} ${NFSOPTS}" + mount.cifs "${NFSROOT}" "${rofsmnt}" "${NFSOPTS}" + [ "$quiet" != "y" ] && log_end_msg +} + +setup_unionfs() { + backdev="$1" + rootmnt="$2" + modprobe -qb unionfs + mkdir -p /cow + cowdevice="tmpfs" + cow_fstype="tmpfs" + # Looking for "${root_persistence}" device or file + if grep -q persistent /proc/cmdline; then + cowprobe=$(find_cow_device "${root_persistence}") + if [ -b "${cowprobe}" ]; then + cowdevice=${cowprobe} + cow_fstype=$(get_fstype "${cowprobe}") + else + [ "$quiet" != "y" ] && log_begin_msg "Unable to find the persistent medium" + fi + fi + + mount ${cowdevice} -t ${cow_fstype} -o rw /cow || panic "Can not mount $cowdevice on /cow" + + mkdir -p /rofs + if grep -q netboot /proc/cmdline; then + do_netmount /rofs || panic "Can not mount netroot on /rofs" + else + if [ "$(get_fstype $backdev)" = "unknown" ]; then + panic "Unknown file system type on $backdev" + fi + mount -t $(get_fstype "$backdev") -o ro "$backdev" /rofs || panic "Can not mount $backdev on /rofs" + fi + + mount -t unionfs -o dirs=/cow=rw:/rofs=ro unionfs "$rootmnt" + if grep -q show-cow /proc/cmdline; then + mkdir -p "$rootmnt/cow" + mount -o bind /cow "$rootmnt/cow" + fi + mkdir -p "$rootmnt/rofs" + mount -o bind /rofs "$rootmnt/rofs" + + # Adding home persitence + if grep -q homepersistence /proc/cmdline; then + homecow=$(find_cow_device "${home_persistence}" ) + if [ -b "${homecow}" ]; then + mount ${homecow} -t $(get_fstype "${homecow}") -o rw "${rootmnt}/home" + else + [ "$quiet" != "y" ] && log_begin_msg "Unable to find the persistent home medium" + fi + fi +} + +is_usb_device() { + sysfs_path="${1#/sys}" + if /lib/udev/path_id "${sysfs_path}" | grep -q "ID_PATH=usb"; then + return 0 + fi + return 1 +} + +find_live() { + mounted= + for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -v loop | grep -v ram); do + devname=$(sys2dev "${sysblock}") + fstype=$(get_fstype "${devname}") + if /lib/udev/cdrom_id ${devname} > /dev/null; then + mount -t ${fstype} -o ro "$devname" $mountpoint || continue + if casper_path $mountpoint; then + echo $(casper_path $mountpoint) + return + else + umount $mountpoint + fi + elif is_usb_device "$sysblock"; then + for dev in $(subdevices "${sysblock}"); do + devname=$(sys2dev "${dev}") + fstype=$(get_fstype "${devname}") + case ${fstype} in + vfat|iso9660|udf) + mount -t ${fstype} -o ro "${devname}" $mountpoint || continue + if casper_path $mountpoint; then + echo $(casper_path $mountpoint) + return + else + umount $mountpoint + fi + ;; + esac + done + elif [ "${fstype}" = "squashfs" ]; then + + # This is an ugly hack situation, the block device has + # a squashfs image directly on it. It's hopefully + # casper, so take it and run with it. + + ln -s "${devname}" "${devname}.${fstype}" + echo "${devname}.${fstype}" + return + fi + done +} + +set_usplash_timeout() { + if [ -x /sbin/usplash_write ]; then + /sbin/usplash_write "TIMEOUT 120" + fi +} + +mountroot() { + exec 6>&1 + exec 7>&2 + exec > casper.log + exec 2>&1 + + set_usplash_timeout + [ "$quiet" != "y" ] && log_begin_msg "Running /scripts/casper-premount" + run_scripts /scripts/casper-premount + [ "$quiet" != "y" ] && log_end_msg + + # Needed here too because some things (*cough* udev *cough*) + # changes the timeout + + set_usplash_timeout + + for i in 0 1 2 3 4 5 6 7 8 9 a b c d e f 10 11 12 13; do + live_image=$(find_live) + if [ "${live_image}" ]; then + break + fi + sleep 1 + done + if [ "$?" -gt 0 ]; then + panic "Unable to find a medium containing a live file system" + fi + + if grep -q toram /proc/cmdline; then + copy_to_ram + fi + + setup_cow "$overlay_method" "$(get_backing_device $live_image)" "$rootmnt" + + # show it on new rootfs + mkdir ${rootmnt}/${mountpoint} + mount -o bind ${mountpoint} ${rootmnt}/${mountpoint} + + log_end_msg + + maybe_break casper-bottom + [ "$quiet" != "y" ] && log_begin_msg "Running /scripts/casper-bottom" + + PATH=/root/usr/bin:/root/usr/sbin:/root/bin:/root/sbin:$PATH run_scripts /scripts/casper-bottom + [ "$quiet" != "y" ] && log_end_msg + + exec 1>&6 6>&- + exec 2>&7 7>&- + cp casper.log "${rootmnt}/var/log/" +} |