NFSv4.1: Ensure that we initialise the session when following a referral

Put the code that is common to both the referral and ordinary mount cases
into a common helper routine.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/client.c

@@ -1286,6 +1286,55 @@ static void nfs4_session_set_rwsize(struct nfs_server *server)
 #endif /* CONFIG_NFS_V4_1 */
 }
 
+static int nfs4_server_common_setup(struct nfs_server *server,
+		struct nfs_fh *mntfh)
+{
+	struct nfs_fattr *fattr;
+	int error;
+
+	BUG_ON(!server->nfs_client);
+	BUG_ON(!server->nfs_client->rpc_ops);
+	BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
+
+	fattr = nfs_alloc_fattr();
+	if (fattr == NULL)
+		return -ENOMEM;
+
+	/* We must ensure the session is initialised first */
+	error = nfs4_init_session(server);
+	if (error < 0)
+		goto out;
+
+	/* Probe the root fh to retrieve its FSID and filehandle */
+	error = nfs4_get_rootfh(server, mntfh);
+	if (error < 0)
+		goto out;
+
+	dprintk("Server FSID: %llx:%llx\n",
+			(unsigned long long) server->fsid.major,
+			(unsigned long long) server->fsid.minor);
+	dprintk("Mount FH: %d\n", mntfh->size);
+
+	nfs4_session_set_rwsize(server);
+
+	error = nfs_probe_fsinfo(server, mntfh, fattr);
+	if (error < 0)
+		goto out;
+
+	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
+		server->namelen = NFS4_MAXNAMLEN;
+
+	spin_lock(&nfs_client_lock);
+	list_add_tail(&server->client_link, &server->nfs_client->cl_superblocks);
+	list_add_tail(&server->master_link, &nfs_volume_list);
+	spin_unlock(&nfs_client_lock);
+
+	server->mount_time = jiffies;
+out:
+	nfs_free_fattr(fattr);
+	return error;
+}
+
 /*
  * Create a version 4 volume record
  */
@@ -1346,7 +1395,6 @@ static int nfs4_init_server(struct nfs_server *server,
 struct nfs_server *nfs4_create_server(const struct nfs_parsed_mount_data *data,
 				      struct nfs_fh *mntfh)
 {
-	struct nfs_fattr *fattr;
 	struct nfs_server *server;
 	int error;
 
@@ -1356,55 +1404,19 @@ struct nfs_server *nfs4_create_server(const struct nfs_parsed_mount_data *data,
 	if (!server)
 		return ERR_PTR(-ENOMEM);
 
-	error = -ENOMEM;
-	fattr = nfs_alloc_fattr();
-	if (fattr == NULL)
-		goto error;
-
 	/* set up the general RPC client */
 	error = nfs4_init_server(server, data);
 	if (error < 0)
 		goto error;
 
-	BUG_ON(!server->nfs_client);
-	BUG_ON(!server->nfs_client->rpc_ops);
-	BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
-
-	error = nfs4_init_session(server);
+	error = nfs4_server_common_setup(server, mntfh);
 	if (error < 0)
 		goto error;
 
-	/* Probe the root fh to retrieve its FSID */
-	error = nfs4_get_rootfh(server, mntfh);
-	if (error < 0)
-		goto error;
-
-	dprintk("Server FSID: %llx:%llx\n",
-		(unsigned long long) server->fsid.major,
-		(unsigned long long) server->fsid.minor);
-	dprintk("Mount FH: %d\n", mntfh->size);
-
-	nfs4_session_set_rwsize(server);
-
-	error = nfs_probe_fsinfo(server, mntfh, fattr);
-	if (error < 0)
-		goto error;
-
-	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
-		server->namelen = NFS4_MAXNAMLEN;
-
-	spin_lock(&nfs_client_lock);
-	list_add_tail(&server->client_link, &server->nfs_client->cl_superblocks);
-	list_add_tail(&server->master_link, &nfs_volume_list);
-	spin_unlock(&nfs_client_lock);
-
-	server->mount_time = jiffies;
 	dprintk("<-- nfs4_create_server() = %p\n", server);
-	nfs_free_fattr(fattr);
 	return server;
 
 error:
-	nfs_free_fattr(fattr);
 	nfs_free_server(server);
 	dprintk("<-- nfs4_create_server() = error %d\n", error);
 	return ERR_PTR(error);
@@ -1418,7 +1430,6 @@ struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *data,
 {
 	struct nfs_client *parent_client;
 	struct nfs_server *server, *parent_server;
-	struct nfs_fattr *fattr;
 	int error;
 
 	dprintk("--> nfs4_create_referral_server()\n");
@@ -1427,11 +1438,6 @@ struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *data,
 	if (!server)
 		return ERR_PTR(-ENOMEM);
 
-	error = -ENOMEM;
-	fattr = nfs_alloc_fattr();
-	if (fattr == NULL)
-		goto error;
-
 	parent_server = NFS_SB(data->sb);
 	parent_client = parent_server->nfs_client;
 
@@ -1456,40 +1462,14 @@ struct nfs_server *nfs4_create_referral_server(struct nfs_clone_mount *data,
 	if (error < 0)
 		goto error;
 
-	BUG_ON(!server->nfs_client);
-	BUG_ON(!server->nfs_client->rpc_ops);
-	BUG_ON(!server->nfs_client->rpc_ops->file_inode_ops);
-
-	/* Probe the root fh to retrieve its FSID and filehandle */
-	error = nfs4_get_rootfh(server, mntfh);
-	if (error < 0)
-		goto error;
-
-	/* probe the filesystem info for this server filesystem */
-	error = nfs_probe_fsinfo(server, mntfh, fattr);
+	error = nfs4_server_common_setup(server, mntfh);
 	if (error < 0)
 		goto error;
 
-	if (server->namelen == 0 || server->namelen > NFS4_MAXNAMLEN)
-		server->namelen = NFS4_MAXNAMLEN;
-
-	dprintk("Referral FSID: %llx:%llx\n",
-		(unsigned long long) server->fsid.major,
-		(unsigned long long) server->fsid.minor);
-
-	spin_lock(&nfs_client_lock);
-	list_add_tail(&server->client_link, &server->nfs_client->cl_superblocks);
-	list_add_tail(&server->master_link, &nfs_volume_list);
-	spin_unlock(&nfs_client_lock);
-
-	server->mount_time = jiffies;
-
-	nfs_free_fattr(fattr);
 	dprintk("<-- nfs_create_referral_server() = %p\n", server);
 	return server;
 
 error:
-	nfs_free_fattr(fattr);
 	nfs_free_server(server);
 	dprintk("<-- nfs4_create_referral_server() = error %d\n", error);
 	return ERR_PTR(error);