ktest.pl: Powercycle the box on reboot if no connection can be made

When performing a reboot of the test box, try to ssh to it. If it can't
connect for 5 seconds, then powercycle the box. This is useful because the
reboot is done via ssh, and if you can't ssh to the box because it is hung,
the reboot fails to reboot.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

tools/testing/ktest/ktest.pl

@@ -1325,26 +1325,44 @@ sub wait_for_monitor;
 
 sub reboot {
     my ($time) = @_;
+    my $powercycle = 0;
 
-    # Make sure everything has been written to disk
-    run_ssh("sync");
+    # test if the machine can be connected to within 5 seconds
+    my $stat = run_ssh("echo check machine status", 5);
+    if (!$stat) {
+	doprint("power cycle\n");
+	$powercycle = 1;
+    }
+
+    if ($powercycle) {
+	run_command "$power_cycle";
 
-    if (defined($time)) {
 	start_monitor;
 	# flush out current monitor
 	# May contain the reboot success line
 	wait_for_monitor 1;
-    }
 
-    # try to reboot normally
-    if (run_command $reboot) {
-	if (defined($powercycle_after_reboot)) {
-	    sleep $powercycle_after_reboot;
+    } else {
+	# Make sure everything has been written to disk
+	run_ssh("sync");
+
+	if (defined($time)) {
+	    start_monitor;
+	    # flush out current monitor
+	    # May contain the reboot success line
+	    wait_for_monitor 1;
+	}
+
+	# try to reboot normally
+	if (run_command $reboot) {
+	    if (defined($powercycle_after_reboot)) {
+		sleep $powercycle_after_reboot;
+		run_command "$power_cycle";
+	    }
+	} else {
+	    # nope? power cycle it.
 	    run_command "$power_cycle";
 	}
-    } else {
-	# nope? power cycle it.
-	run_command "$power_cycle";
     }
 
     if (defined($time)) {