Determine dependency for target device

Try to get all dependencies for the specified device.
This will help to support arbitrary stacked devices like lvm on raid,
raid on lvm or lvm on raid on raid

diff --git a/42_grml b/42_grml
index 6e82b90..08108a4 100755 (executable)
--- a/42_grml
+++ b/42_grml
@@ -21,6 +21,58 @@ if [ -r /etc/default/grml-rescueboot ] ; then
   . /etc/default/grml-rescueboot
 fi
 
+resolve_dm_name() {
+  retval="$1"
+  base=${1##*/}
+  for block in /sys/block /sys/class/block ; do
+    [ ! -d ${block}/${base}/dm ] && continue
+    retval="/dev/mapper/$(cat ${block}/${base}/dm/name)"
+    break
+  done
+  case "$retval" in
+    /dev/dm-*)
+    minor=${retval##*-}
+   retval="/dev/mapper/$(dmsetup info -C --noheadings -o name -j 253 -m $minor)"
+    ;;
+  esac
+
+  echo "$retval"
+}
+
+get_dependencies() {
+  device=${1}
+  if [ -z ${device} ] ; then
+    return
+  fi
+  device=$(readlink -f ${device})
+  case "$device" in
+    /dev/mapper/*)
+    device="/dev/dm-$(dmsetup info -C --noheadings -o minor "$device")"
+    ;;
+  esac
+
+  base=${device##*/}
+  dependencies=""
+  additional_dependencies=""
+  for block in /sys/block /sys/class/block ; do
+    [ ! -d ${block}/${base}/slaves ] && continue
+    for file in  ${block}/${base}/slaves/* ; do
+      dep_name="/dev/${file##*/}"
+      dep_name=$(resolve_dm_name ${dep_name})
+
+      # resolve recursively all dependencies
+      additional_dependencies=$(get_dependencies ${dep_name})
+
+      dependencies="$dependencies $additional_dependencies $dep_name"
+    done
+    break
+  done
+  echo $dependencies
+
+}
+
+
+
 iso_list=""
 for file in "${ISO_LOCATION}"/*.iso ; do
      if grub_file_is_not_garbage "$file" ; then
@@ -36,9 +88,15 @@ for grmliso in $iso_list ; do
   additional_param=""
 
   case "$device" in
-      /dev/mapper*|/dev/md*)
-      additional_param="live-media=$device"
-      ;;
+    /dev/mapper*|/dev/md*)
+      dependencies=$(get_dependencies ${device})
+      dep_string=""
+      for dep in $dependencies $device ; do
+        dep_string="$dep_string,$dep"
+      done
+      dep_string=${dep_string#,}
+      additional_param="live-media=$dep_string"
+    ;;
   esac
 
   echo "Found Grml ISO image: $grmliso" >&2