lockd: Do not start the lockd thread before we've set nlmsvc_rqst->rq_task

This fixes an Oopsable race when starting lockd.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
Reviewed-by: Jeff Layton <jlayton@primarydata.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

fs/lockd/svc.c

@@ -306,7 +306,7 @@ static int lockd_start_svc(struct svc_serv *serv)
 	svc_sock_update_bufs(serv);
 	serv->sv_maxconn = nlm_max_connections;
 
-	nlmsvc_task = kthread_run(lockd, nlmsvc_rqst, "%s", serv->sv_name);
+	nlmsvc_task = kthread_create(lockd, nlmsvc_rqst, "%s", serv->sv_name);
 	if (IS_ERR(nlmsvc_task)) {
 		error = PTR_ERR(nlmsvc_task);
 		printk(KERN_WARNING
@@ -314,6 +314,7 @@ static int lockd_start_svc(struct svc_serv *serv)
 		goto out_task;
 	}
 	nlmsvc_rqst->rq_task = nlmsvc_task;
+	wake_up_process(nlmsvc_task);
 
 	dprintk("lockd_up: service started\n");
 	return 0;