Handle re-used pids in pidfile_is_running

Since pids can be re-used, it is necessary to check that the
process that is running with a pid matches the one that we expect.

This adds the ability to optionally pass a 'binary' argument to
pidfile_is_running, and if it is passed to match the binary against
/proc/$pid/exe.

Signed-off-by: Terry Wilson <twilson@redhat.com>
Signed-off-by: Mark Michelson <mmichels@redhat.com>
Acked-by: Ihar Hrachyshka <ihrachys@redhat.com>
Acked-by: Mark Michelson <mmichels@redhat.com>

utilities/ovn-ctl

@@ -42,7 +42,8 @@ ovn_ic_db_conf_file="$ovn_etcdir/ovn-ic-db-params.conf"
 
 pidfile_is_running () {
     pidfile=$1
-    test -e "$pidfile" && [ -s "$pidfile" ] && pid=`cat "$pidfile"` && pid_exists "$pid"
+    cmd=$2
+    test -e "$pidfile" && [ -s "$pidfile" ] && pid=`cat "$pidfile"` && pid_exists "$pid" && [ -z $cmd -o pid_comm_check "$cmd" "$pid" ]
 } >/dev/null 2>&1
 
 stop_nb_ovsdb() {