NFS: callback service start function introduced

This is just a code move, which from my POW makes code looks better.
I.e. now on start we have 3 different stages:
1) Service creation.
2) Service per-net data allocation.
3) Service start.

Patch also renames goto label "out_err:" into "err_start:" to reflect new
changes.
Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/callback.c

@@ -217,6 +217,46 @@ static inline void nfs_callback_bc_serv(u32 minorversion, struct rpc_xprt *xprt,
 }
 #endif /* CONFIG_NFS_V4_1 */
 
+static int nfs_callback_start_svc(int minorversion, struct rpc_xprt *xprt,
+				  struct svc_serv *serv)
+{
+	struct svc_rqst *rqstp;
+	int (*callback_svc)(void *vrqstp);
+	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
+	char svc_name[12];
+	int ret;
+	int minorversion_setup;
+
+	nfs_callback_bc_serv(minorversion, xprt, serv);
+
+	minorversion_setup =  nfs_minorversion_callback_svc_setup(minorversion,
+					serv, &rqstp, &callback_svc);
+	if (!minorversion_setup) {
+		/* v4.0 callback setup */
+		rqstp = nfs4_callback_up(serv);
+		callback_svc = nfs4_callback_svc;
+	}
+
+	if (IS_ERR(rqstp))
+		return PTR_ERR(rqstp);
+
+	svc_sock_update_bufs(serv);
+
+	sprintf(svc_name, "nfsv4.%u-svc", minorversion);
+	cb_info->serv = serv;
+	cb_info->rqst = rqstp;
+	cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name);
+	if (IS_ERR(cb_info->task)) {
+		ret = PTR_ERR(cb_info->task);
+		svc_exit_thread(cb_info->rqst);
+		cb_info->rqst = NULL;
+		cb_info->task = NULL;
+		return PTR_ERR(cb_info->task);
+	}
+	dprintk("nfs_callback_up: service started\n");
+	return 0;
+}
+
 static int nfs_callback_up_net(int minorversion, struct svc_serv *serv, struct net *net)
 {
 	int ret;
@@ -299,12 +339,8 @@ static struct svc_serv *nfs_callback_create_svc(int minorversion)
 int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
 {
 	struct svc_serv *serv;
-	struct svc_rqst *rqstp;
-	int (*callback_svc)(void *vrqstp);
 	struct nfs_callback_data *cb_info = &nfs_callback_info[minorversion];
-	char svc_name[12];
 	int ret = 0;
-	int minorversion_setup;
 	struct net *net = xprt->xprt_net;
 
 	mutex_lock(&nfs_callback_mutex);
@@ -324,34 +360,10 @@ int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
 	if (ret < 0)
 		goto err_net;
 
-	nfs_callback_bc_serv(minorversion, xprt, serv);
-
-	minorversion_setup =  nfs_minorversion_callback_svc_setup(minorversion,
-					serv, &rqstp, &callback_svc);
-	if (!minorversion_setup) {
-		/* v4.0 callback setup */
-		rqstp = nfs4_callback_up(serv);
-		callback_svc = nfs4_callback_svc;
-	}
-
-	if (IS_ERR(rqstp)) {
-		ret = PTR_ERR(rqstp);
-		goto out_err;
-	}
-
-	svc_sock_update_bufs(serv);
+	ret = nfs_callback_start_svc(minorversion, xprt, serv);
+	if (ret < 0)
+		goto err_start;
 
-	sprintf(svc_name, "nfsv4.%u-svc", minorversion);
-	cb_info->serv = serv;
-	cb_info->rqst = rqstp;
-	cb_info->task = kthread_run(callback_svc, cb_info->rqst, svc_name);
-	if (IS_ERR(cb_info->task)) {
-		ret = PTR_ERR(cb_info->task);
-		svc_exit_thread(cb_info->rqst);
-		cb_info->rqst = NULL;
-		cb_info->task = NULL;
-		goto out_err;
-	}
 out:
 	/*
 	 * svc_create creates the svc_serv with sv_nrthreads == 1, and then
@@ -363,7 +375,8 @@ int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt)
 err_create:
 	mutex_unlock(&nfs_callback_mutex);
 	return ret;
-out_err:
+
+err_start:
 	svc_shutdown_net(serv, net);
 err_net:
 	dprintk("NFS: Couldn't create callback socket or server thread; "