NFS: Create an alloc_client rpc_op

This gives NFS v4 a way to set up callbacks and sessions without v2 or
v3 having to do them as well.

Signed-off-by: Bryan Schumaker <bjschuma@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h
index 9889ee4..a0be2d1a 100644
--- a/fs/nfs/nfs4_fs.h
+++ b/fs/nfs/nfs4_fs.h
@@ -303,6 +303,8 @@
 
 void nfs4_free_client(struct nfs_client *);
 
+struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *);
+
 /* nfs4renewd.c */
 extern void nfs4_schedule_state_renewal(struct nfs_client *);
 extern void nfs4_renewd_prepare_shutdown(struct nfs_server *);