ktest: Add timeout for ssh sync testing

commit 4d00fc47 upstream.

Before rebooting the box, a "ssh sync" is called to the test machine to see
if it is alive or not. But if the test machine is in a partial state, that
ssh may never actually finish, and the ktest test hangs.

Add a 10 second timeout to the sync test, which will fail after 10 seconds
and then cause the test to reboot the test machine.

Cc: stable@vger.kernel.org
Fixes: 6474ace9 ("ktest.pl: Powercycle the box on reboot if no connection can be made")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

tools/testing/ktest/ktest.pl

@@ -1372,7 +1372,7 @@ sub reboot {
 
     } else {
 	# Make sure everything has been written to disk
-	run_ssh("sync");
+	run_ssh("sync", 10);
 
 	if (defined($time)) {
 	    start_monitor;