void-packages/srcpkgs/xbps-casper/files/scripts/casper-helpers

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## Casper helper functions, used by casper on boot and by casper-snapshot
MP_QUIET="-q"
sys2dev() {
sysdev=${1#/sys}
echo "/dev/$(/sbin/udevadm info -q name -p ${sysdev} 2>/dev/null|| echo ${sysdev##*/})"
}
subdevices() {
sysblock=$1
r=""
for dev in "${sysblock}" "${sysblock}"/*; do
if [ -e "${dev}/dev" ]; then
r="${r} ${dev}"
fi
done
echo ${r}
}
is_supported_fs () {
# FIXME: do something better like the scan of supported filesystems
fstype="${1}"
case ${fstype} in
vfat|iso9660|udf|ext2|ext3|ext4|ntfs)
return 0
;;
esac
return 1
}
get_fstype() {
/sbin/blkid -s TYPE -o value $1 2>/dev/null
}
where_is_mounted() {
device=$1
if grep -q "^$device " /proc/mounts; then
mountpoint="$(grep "^$device " /proc/mounts | awk '{print $2; exit}')"
grep "^$device " /proc/mounts | read d mountpoint rest
echo $mountpoint
return 0
fi
return 1
}
lastline() {
while read lines ; do
line=${lines}
done
echo "${line}"
}
base_path ()
{
testpath="${1}"
mounts="$(awk '{print $2}' /proc/mounts)"
testpath="$(busybox realpath ${testpath})"
while true ; do
if echo "${mounts}" | grep -qs "^${testpath}" ; then
set -- `echo "${mounts}" | grep "^${testpath}" | lastline`
echo ${1}
break
else
testpath=`dirname $testpath`
fi
done
}
fs_size ()
{
# Returns used/free fs kbytes + 5% more
# You could pass a block device as $1 or the mount point as $2
dev="${1}"
mountp="${2}"
used="${3}"
if [ -z "${mountp}" ]; then
mountp=$(where_is_mounted "${dev}")
if [ "$?" -gt 0 ]; then
mountp="/mnt/tmp_fs_size"
mkdir -p "${mountp}"
mount -t $(get_fstype "${dev}") -o ro "${dev}" "${mountp}"
doumount=1
fi
fi
if [ "${used}" = "used" ]; then
size=$(du -ks ${mountp} | cut -f1)
size=$(expr ${size} + ${size} / 20 ) # FIXME: 5% more to be sure
else
# free space
size="$(df -k | grep -s ${mountp} | awk '{print $4}')"
fi
if [ -n "${doumount}" ]; then
umount "${mountp}"
rmdir "${mountp}"
fi
echo "${size}"
}
setup_loop() {
local fspath=$1
local module=$2
local pattern=$3
local offset=$4
modprobe ${MP_QUIET} -b "$module"
/sbin/udevadm settle
if [ "$module" = loop ]; then
if [ ! -e /dev/loop0 ]; then
# temporary workaround for kernel bug
for i in 0 1 2 3 4 5 6 7; do
mknod "/dev/loop$i" b 7 "$i" || true
done
fi
dev="$(losetup -f)"
if [ "$dev" ]; then
if [ -n "$offset" ]; then
losetup -o "$offset" "$dev" "$fspath"
else
losetup "$dev" "$fspath"
fi
echo "$dev"
return 0
else
panic "No loop devices available"
fi
else
for loopdev in $pattern; do
if [ "$(cat $loopdev/size)" -eq 0 ]; then
dev=$(sys2dev "${loopdev}")
if [ -n "$offset" ]; then
losetup -o "$offset" "$dev" "$fspath"
else
losetup "$dev" "$fspath"
fi
echo "$dev"
return 0
fi
done
panic "No loop devices available"
fi
}
try_mount ()
{
dev="${1}"
mountp="${2}"
opts="${3}"
if where_is_mounted ${dev} > /dev/null; then
if [ "${opts}" != "ro" ]; then
mount -o remount,"${opts}" ${dev} $(where_is_mounted ${dev}) || panic "Remounting failed"
fi
mount -o bind $(where_is_mounted ${dev}) ${mountp} || panic "Cannot bind-mount"
else
mount -t $(get_fstype "${dev}") -o "${opts}" "${dev}" "${mountp}" || panic "Cannot mount ${dev} on ${mountp}"
fi
}
find_cow_device() {
pers_label="${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 [ "$(/sbin/blkid -s LABEL -o value $devname 2>/dev/null)" = "${pers_label}" ]; then
echo "$devname"
return
# Do not add any filesystem types here that might be able to
# mount a journalled filesystem and replay the journal. Doing so
# will cause data loss when a live CD is booted on a system
# where filesystems are in use by hibernated operating systems.
elif [ "$(get_fstype ${devname})" = "vfat" ]; then
mkdir -p "${cow_backing}"
try_mount "${devname}" "${cow_backing}" "rw"
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
}
find_files()
# return the first of $filenames found on vfat and ext2 devices
# FIXME: merge with above function
{
filenames="${1}"
snap_backing="/snap-backing"
for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -v loop); do
for dev in $(subdevices "${sysblock}"); do
devname=$(sys2dev "${dev}")
devfstype="$(get_fstype ${devname})"
if [ "${devfstype}" = "vfat" ] || [ "${devfstype}" = "ext2" ] ; then # FIXME: all supported block devices should be scanned
mkdir -p "${snap_backing}"
try_mount "${devname}" "${snap_backing}" "ro"
for filename in ${filenames}; do
if [ -e "${snap_backing}/${filename}" ]; then
echo "${devname} ${snap_backing} ${filename}"
return 0
fi
done
umount ${snap_backing}
fi
done
done
}