lsinitrd: list squash content as well

When the initramfs is built with squash module enabled, the content
inside squash image will be invisible from the lsinitrd tool. This
commit make lsinitrd detect and list the content of the squash image as
well to avoid possible confusion.

Signed-off-by: Kairui Song <kasong@redhat.com>

lsinitrd.sh

@@ -160,6 +160,21 @@ list_files()
     echo "========================================================================"
 }
 
+list_squash_content()
+{
+    SQUASH_IMG="squash/root.img"
+    SQUASH_TMPFILE="$(mktemp -t --suffix=.root.sqsh lsinitrd.XXXXXX)"
+    trap "rm -f '$SQUASH_TMPFILE'" EXIT
+    $CAT "$image" 2>/dev/null | cpio --extract --verbose --quiet --to-stdout -- \
+        $SQUASH_IMG > "$SQUASH_TMPFILE" 2>/dev/null
+    if [[ -s $SQUASH_TMPFILE ]]; then
+        echo "Squashed content ($SQUASH_IMG):"
+        echo "========================================================================"
+        unsquashfs -ll "$SQUASH_TMPFILE" | tail -n +4
+        echo "========================================================================"
+    fi
+}
+
 unpack_files()
 {
     if (( ${#filenames[@]} > 0 )); then
@@ -287,6 +302,7 @@ else
         echo
         list_modules
         list_files
+        list_squash_content
     fi
 fi