functions/losetup.sh

   1 #!/bin/sh
   2
   3 ## live-build(7) - System Build Scripts
   4 ## Copyright (C) 2006-2015 Daniel Baumann <mail@daniel-baumann.ch>
   5 ##
   6 ## This program comes with ABSOLUTELY NO WARRANTY; for details see COPYING.
   7 ## This is free software, and you are welcome to redistribute it
   8 ## under certain conditions; see COPYING for details.
   9
  10 Lodetach ()
  11 {
  12         DEVICE="${1}"
  13         ATTEMPT="${2:-1}"
  14
  15         if [ "${ATTEMPT}" -gt 3 ]
  16         then
  17                 Echo_error "Failed to detach loop device '${DEVICE}'."
  18                 exit 1
  19         fi
  20
  21         # Changes to block devices result in uevents which trigger rules which in
  22         # turn access the loop device (ex. udisks-part-id, blkid) which can cause
  23         # a race condition. We call 'udevadm settle' to help avoid this.
  24         if [ -x "$(which udevadm 2>/dev/null)" ]
  25         then
  26                 udevadm settle
  27         fi
  28
  29         # Loop back devices aren't the most reliable when it comes to writes.
  30         # We sleep and sync for good measure - better than build failure.
  31         sync
  32         sleep 1
  33
  34         ${LB_LOSETUP} -d "${DEVICE}" || Lodetach "${DEVICE}" "$(expr ${ATTEMPT} + 1)"
  35 }
  36
  37 Losetup ()
  38 {
  39         DEVICE="${1}"
  40         FILE="${2}"
  41         PARTITION="${3:-1}"
  42
  43         ${LB_LOSETUP} --read-only "${DEVICE}" "${FILE}"
  44         FDISK_OUT="$(${LB_FDISK} -l -u ${DEVICE} 2>&1)"
  45         Lodetach "${DEVICE}"
  46
  47         LOOPDEVICE="$(echo ${DEVICE}p${PARTITION})"
  48
  49         if [ "${PARTITION}" = "0" ]
  50         then
  51                 Echo_message "Mounting %s with offset 0" "${DEVICE}"
  52
  53                 ${LB_LOSETUP} "${DEVICE}" "${FILE}"
  54         else
  55                 SECTORS="$(echo "$FDISK_OUT" | sed -ne "s|^$LOOPDEVICE[ *]*\([0-9]*\).*|\1|p")"
  56                 OFFSET="$(expr ${SECTORS} '*' 512)"
  57
  58                 Echo_message "Mounting %s with offset %s" "${DEVICE}" "${OFFSET}"
  59
  60                 ${LB_LOSETUP} -o "${OFFSET}" "${DEVICE}" "${FILE}"
  61         fi
  62 }
  63
  64 Calculate_partition_size ()
  65 {
  66         ORIGINAL_SIZE="${1}"
  67         FILESYSTEM="${2}"
  68
  69         case "${FILESYSTEM}" in
  70                 ext2|ext3|ext4)
  71                         PERCENT="6"
  72                         ;;
  73                 *)
  74                         PERCENT="3"
  75                         ;;
  76         esac
  77
  78         echo $(expr ${ORIGINAL_SIZE} + ${ORIGINAL_SIZE} \* ${PERCENT} / 100 + 1)
  79 }