added check

jaildk

@@ -133,6 +133,9 @@ jaildk_rc_rcoff() {
         # not required in run mode
         case $mode in
             start)
+                if mount | egrep -q "rcoff.*build/$jail"; then
+                    bold "union mount $j/build/jail/etc already mounted"
+                else
                     if ! test -d $j/etc/rcoff; then
                         # in order to be backwards compatible to older jaildk
                         # create the rcoff directory on the fly
@@ -142,6 +145,7 @@ jaildk_rc_rcoff() {
                     fi
 
                     ex mount -t unionfs $j/etc/rcoff $j/build/$jail/etc
+                fi
                 ;;
             stop)
                 # might fail if executed on a yet not union'ed etc