scripts/forensic-mark-readonly: Add support for loop devices

Signed-off-by: Glenn Washburn <[email protected]>

Author: crass

config/files/GRMLBASE/etc/udev/scripts/forensic-mark-readonly

@@ -63,6 +63,23 @@ trap cleanup ERR 2>/dev/null ||:
 
 base_device=$(base "${BLOCK_DEVICE}")
 if [ -n "${SYS_DIR}" ] && [ -n "${base_device}" ] ; then
+  if [ -z "${base_device##loop[0-9]*}" ] ; then
+    if [ -e "${SYS_DIR}"/"${base_device}"/loop/backing_file ] ; then
+      backingfile=$(cat "${SYS_DIR}"/"${base_device}"/loop/backing_file)
+      parent_devices=$(findmnt -n -o source --target "$backingfile")
+
+      # Set loop device to read-write, will be set to readonly later if need be
+      blockdev --setrw "${BLOCK_DEVICE}"
+
+      # Check if either the backing file's block device or filesystem are read-only
+      if is_ro "$parent_devices" || findmnt -n -o OPTIONS --target "$backingfile" | grep -E '^ro,|,ro,|,ro$'; then
+        blockdev --setro "${BLOCK_DEVICE}"
+        logger -t forensic-mark-readonly "setting '${BLOCK_DEVICE}' with backing file (${backingfile}) (parent devices: '${parent_devices}') to read-only as its parent is present or mount point ($(findmnt -n -o TARGET --target "$backingfile")) is read-only"
+      fi
+      exit 0
+    fi
+  fi
+
   tmp_parents="$(readlink -f "${SYS_DIR}"/*/"${base_device}")"
   if [ -z "${tmp_parents}" ]; then
     tmp_parents=