components/0020-read-only

   1 #!/bin/sh
   2
   3 #set -e
   4
   5 Read_only ()
   6 {
   7         for _PARAMETER in ${LIVE_BOOT_CMDLINE}
   8         do
   9                 case "${_PARAMETER}" in
  10                         live-boot.read-only=*|read-only=*)
  11                                 LIVE_READ_ONLY="true"
  12                                 LIVE_READ_ONLY_DEVICES="${_PARAMETER#*read-only=}"
  13                                 ;;
  14
  15                         live-boot.read-only|read-only)
  16                                 LIVE_READ_ONLY="true"
  17                                 ;;
  18                 esac
  19         done
  20
  21         case "${LIVE_READ_ONLY}" in
  22                 true)
  23                         ;;
  24
  25                 *)
  26                         return 0
  27                         ;;
  28         esac
  29
  30         # Marking some block devices as read-only to ensure that nothing
  31         # gets written as linux still writes to 'only' read-only mounted filesystems.
  32         LIVE_READ_ONLY_DEVICES="${LIVE_READ_ONLY_DEVICES:-/dev/sd* /dev/vd*}"
  33
  34         for _DEVICE in $(echo ${LIVE_READ_ONLY_DEVICES} | sed -e 's|,| |g')
  35         do
  36                 if [ ! -b "${_DEVICE}" ]
  37                 then
  38                         continue
  39                 fi
  40
  41                 echo -n "live-boot: Setting ${_DEVICE} read-only..." > /dev/console
  42
  43                 blockdev --setro ${_DEVICE}
  44                 _RETURN="${?}"
  45
  46                 case "${_RETURN}" in
  47                         0)
  48                                 echo " done, use 'blockdev --setrw ${_DEVICE}' to set read-write." > /dev/console
  49                                 ;;
  50
  51                         *)
  52                                 echo " failed." > /dev/console
  53                                 ;;
  54                 esac
  55         done
  56 }