#!/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/" }