libceph: drop connection refcounting for mon_client

(cherry picked from commit ec87ef43)

All references to the embedded ceph_connection come from the msgr
workqueue, which is drained prior to mon_client destruction.  That
means we can ignore con refcounting entirely.
Signed-off-by: Sage Weil <sage@newdream.net>
Reviewed-by: Alex Elder <elder@inktank.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

net/ceph/mon_client.c

@@ -1037,9 +1037,23 @@ static void mon_fault(struct ceph_connection *con)
 	mutex_unlock(&monc->mutex);
 }
 
+/*
+ * We can ignore refcounting on the connection struct, as all references
+ * will come from the messenger workqueue, which is drained prior to
+ * mon_client destruction.
+ */
+static struct ceph_connection *con_get(struct ceph_connection *con)
+{
+	return con;
+}
+
+static void con_put(struct ceph_connection *con)
+{
+}
+
 static const struct ceph_connection_operations mon_con_ops = {
-	.get = ceph_con_get,
-	.put = ceph_con_put,
+	.get = con_get,
+	.put = con_put,
 	.dispatch = dispatch,
 	.fault = mon_fault,
 	.alloc_msg = mon_alloc_msg,