extrahd.cgi: Add is_configured function.

Signed-off-by: Stefan Schantl <stefan.schantl@ipfire.org>
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>

html/cgi-bin/extrahd.cgi

@@ -690,3 +690,15 @@ sub is_swap ($) {
 
 	return 1 if(grep /$device/, @swaps);
 }
+
+#
+## Returns "True" if a drive is a configured one.
+#
+sub is_configured ($) {
+	my ($path) = @_;
+
+	# Loop through the hash of configured drives.
+	foreach my $uuid (keys %configured_drives) {
+	       return 1 if($configured_drives{$uuid} eq "$path");
+	}
+}