Adding upstream version 4.0~a14.

[live-boot-grml.git] / components / 0020-read-only

diff --git a/components/0020-read-only b/components/0020-read-only
new file mode 100755 (executable)
index 0000000..fc0dde0
--- /dev/null
+++ b/components/0020-read-only
@@ -0,0 +1,56 @@
+#!/bin/sh
+
+#set -e
+
+Read_only ()
+{
+       for _PARAMETER in ${LIVE_BOOT_CMDLINE}
+       do
+               case "${_PARAMETER}" in
+                       live-boot.read-only=*|read-only=*)
+                               LIVE_READ_ONLY="true"
+                               LIVE_READ_ONLY_DEVICES="${_PARAMETER#*read-only=}"
+                               ;;
+
+                       live-boot.read-only|read-only)
+                               LIVE_READ_ONLY="true"
+                               ;;
+               esac
+       done
+
+       case "${LIVE_READ_ONLY}" in
+               true)
+                       ;;
+
+               *)
+                       return 0
+                       ;;
+       esac
+
+       # Marking some block devices as read-only to ensure that nothing
+       # gets written as linux still writes to 'only' read-only mounted filesystems.
+       LIVE_READ_ONLY_DEVICES="${LIVE_READ_ONLY_DEVICES:-/dev/sd* /dev/vd*}"
+
+       for _DEVICE in $(echo ${LIVE_READ_ONLY_DEVICES} | sed -e 's|,| |g')
+       do
+               if [ ! -b "${_DEVICE}" ]
+               then
+                       continue
+               fi
+
+               echo -n "live-boot: Setting ${_DEVICE} read-only..." > /dev/console
+
+               blockdev --setro ${_DEVICE}
+               _RETURN="${?}"
+
+               case "${_RETURN}" in
+                       0)
+                               echo " done, use 'blockdev --setrw ${_DEVICE}' to set read-write." > /dev/console
+                               ;;
+
+                       *)
+                               echo " failed." > /dev/console
+                               ;;
+               esac
+       done
+}