scripts/casper-helpers

   1 ## Casper helper functions, used by casper on boot and by casper-snapshot
   2
   3 if [ "${BUILD_SYSTEM}" = "Ubuntu" ]; then
   4     MP_QUIET="-Q"
   5 elif [ "${BUILD_SYSTEM}" = "Debian" ]; then
   6     MP_QUIET="-q"
   7 else
   8     MP_QUIET=""
   9 fi
  10
  11 if [ ! -x "/bin/fstype" ]; then
  12     # klibc not in path -> not in initramfs
  13     export PATH="${PATH}:/usr/lib/klibc/bin"
  14 fi
  15
  16 sys2dev() {
  17     sysdev=${1#/sys}
  18     echo "/dev/$(udevinfo -q name -p ${sysdev} 2>/dev/null|| echo ${sysdev##*/})"
  19 }
  20
  21 subdevices() {
  22     sysblock=$1
  23     r=""
  24     for dev in "${sysblock}" "${sysblock}"/*; do
  25         if [ -e "${dev}/dev" ]; then
  26             r="${r} ${dev}"
  27         fi
  28     done
  29     echo ${r}
  30 }
  31
  32 get_fstype() {
  33     local FSTYPE
  34     local FSSIZE
  35     eval $(fstype < $1)
  36     if [ "$FSTYPE" != "unknown" ]; then
  37         echo $FSTYPE
  38         return 0
  39     fi
  40     /lib/udev/vol_id -t $1 2>/dev/null
  41 }
  42
  43 where_is_mounted() {
  44     device=$1
  45     if grep -q "^$device " /proc/mounts; then
  46         grep "^$device " /proc/mounts | read d mountpoint rest
  47         echo $mountpoint
  48         return 0
  49     fi
  50     return 1
  51 }
  52
  53 lastline() {
  54     while read lines ; do
  55         line=${lines}
  56     done
  57     echo "${line}"
  58 }
  59
  60 base_path ()
  61 {
  62     testpath="${1}"
  63     mounts="$(awk '{print $2}' /proc/mounts)"
  64     testpath="$(busybox realpath ${testpath})"
  65
  66     while true ; do
  67         if echo "${mounts}" | grep -qs "^${testpath}" ; then
  68             set -- `echo "${mounts}" | grep "^${testpath}" | lastline`
  69             echo ${1}
  70             break
  71         else
  72             testpath=`dirname $testpath`
  73         fi
  74     done
  75 }
  76
  77 fs_size ()
  78 {
  79     # Returns used/free fs kbytes + 5% more
  80     # You could pass a block device as $1 or the mount point as $2
  81
  82     dev="${1}"
  83     mountp="${2}"
  84     used="${3}"
  85
  86     if [ -z "${mountp}" ]; then
  87         mountp=$(where_is_mounted "${dev}")
  88         if [ "$?" -gt 0 ]; then
  89             mountp="/mnt/tmp_fs_size"
  90             mkdir -p "${mountp}"
  91             mount -t $(get_fstype "${dev}") -o ro "${dev}" "${mountp}"
  92             doumount=1
  93         fi
  94     fi
  95
  96     if [ "${used}" = "used" ]; then
  97         size=$(du -ks ${mountp} | cut -f1)
  98         size=$(expr ${size} + ${size} / 20 ) # FIXME: 5% more to be sure
  99     else
 100         # free space
 101         size="$(df -k | grep -s ${mountp} | awk '{print $4}')"
 102     fi
 103
 104     if [ -n "${doumount}" ]; then
 105         umount "${mountp}"
 106         rmdir "${mountp}"
 107     fi
 108     echo "${size}"
 109 }
 110
 111 setup_loop() {
 112     local fspath=$1
 113     local module=$2
 114     local pattern=$3
 115     local offset=$4
 116     local encryption=$5
 117
 118     modprobe ${MP_QUIET} -b "$module"
 119     udevsettle
 120
 121     for loopdev in $pattern; do
 122         if [ "$(cat $loopdev/size)" -eq 0 ]; then
 123             dev=$(sys2dev "${loopdev}")
 124             options=''
 125             if [ 0 -lt "${offset}" ]; then
 126                 options="${options} -o ${offset}"
 127             fi
 128             if [ -z "${encryption}" ]; then
 129                 losetup ${options} "${dev}" "${fspath}"
 130             else
 131                 # Loop AES encryption
 132                 while true; do
 133                     echo -n "Enter passphrase for ${fspath}: " >&6
 134                     read -s passphrase
 135                     echo "${passphrase}" > /tmp/passphrase
 136                     exec 9</tmp/passphrase
 137                     /sbin/losetup ${options} -e "${encryption}" -p 9 "${dev}" "${fspath}"
 138                     error=$?
 139                     exec 9<&-
 140                     rm -f /tmp/passphrase
 141                     if [ 0 -eq ${error} ]; then
 142                         unset error
 143                         break
 144                     fi
 145                     echo -n "Something went wrong... Retry? [YES/no] " >&6
 146                     read answer
 147                     if [ 'no' = "${answer}" ]; then
 148                         unset answer
 149                         break
 150                     fi
 151                 done
 152             fi
 153             echo "$dev"
 154             return 0
 155         fi
 156     done
 157     panic "No loop devices available"
 158 }
 159
 160 try_mount ()
 161 {
 162     dev="${1}"
 163     mountp="${2}"
 164     opts="${3}"
 165
 166     if where_is_mounted ${dev} > /dev/null; then
 167         mount -o remount,"${opts}" ${dev} $(where_is_mounted ${dev}) || panic "Remounting failed"
 168         mount -o bind $(where_is_mounted ${dev}) ${mountp} || panic "Cannot bind-mount"
 169     else
 170         mount -t $(get_fstype "${dev}") -o "${opts}" "${dev}" "${mountp}" || panic "Cannot mount ${dev} on ${mountp}"
 171     fi
 172 }
 173
 174 find_cow_device() {
 175     pers_label="${1}"
 176     cow_backing="/${pers_label}-backing"
 177     for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -v loop); do
 178         for dev in $(subdevices "${sysblock}"); do
 179             devname=$(sys2dev "${dev}")
 180             if [ "$(/lib/udev/vol_id -l $devname 2>/dev/null)" = "${pers_label}" ]; then
 181                 echo "$devname"
 182                 return
 183             elif [ "$(get_fstype ${devname})" = "vfat" ]; then # FIXME: all supported block devices should be scanned
 184                 mkdir -p "${cow_backing}"
 185                 try_mount "${devname}" "${cow_backing}" "rw"
 186                 if [ -e "${cow_backing}/${pers_label}" ]; then
 187                     echo $(setup_loop "${cow_backing}/${pers_label}" "loop" "/sys/block/loop*")
 188                     return 0
 189                 else
 190                     umount ${cow_backing}
 191                 fi
 192             fi
 193         done
 194     done
 195 }
 196
 197 find_files()
 198 # return the first of $filenames found on vfat and ext2 devices
 199 # FIXME: merge with above function
 200 {
 201     filenames="${1}"
 202     snap_backing="/snap-backing"
 203     for sysblock in $(echo /sys/block/* | tr ' ' '\n' | grep -v loop); do
 204         for dev in $(subdevices "${sysblock}"); do
 205             devname=$(sys2dev "${dev}")
 206             devfstype="$(get_fstype ${devname})"
 207             if [ "${devfstype}" = "vfat" ] ||  [ "${devfstype}" = "ext2" ] ; then # FIXME: all supported block devices should be scanned
 208                 mkdir -p "${snap_backing}"
 209                 try_mount "${devname}" "${snap_backing}" "ro"
 210                 for filename in ${filenames}; do
 211                     if [ -e "${snap_backing}/${filename}" ]; then
 212                         echo "${devname} ${snap_backing} ${filename}"
 213                         return 0
 214                     fi
 215                 done
 216                 umount ${snap_backing}
 217             fi
 218         done
 219     done
 220 }
 221
 222