Hi - thanks for testing 3.2.1.
The best way to file a bug report is to send mail to linux-raid@vger.kernel.org - you don't need to subscribe to be able to post and get replies.
However your bug is probably the one fixed by http://neil.brown.name/git?p=mdadm;a=commitdiff;h=eb28e119b03fd5149886ed516fa4bb006ad3602e. so you could just apply that patch, or use git to get the very latest from the 'master' branch of git://neil.brown.name/md.
Thanks, NeilBrown
