NFSv4: Reintroduce machine creds

We need to try to ensure that we always use the same credentials whenever
we re-establish the clientid on the server. If not, the server won't
recognise that we're the same client, and so may not allow us to recover
state.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/include/linux/nfs_fs_sb.h b/include/linux/nfs_fs_sb.h
index ac7e4fb..c9beacd 100644
--- a/include/linux/nfs_fs_sb.h
+++ b/include/linux/nfs_fs_sb.h
@@ -32,6 +32,8 @@
 	const struct nfs_rpc_ops *rpc_ops;	/* NFS protocol vector */
 	int			cl_proto;	/* Network transport protocol */
 
+	struct rpc_cred		*cl_machine_cred;
+
 #ifdef CONFIG_NFS_V4
 	u64			cl_clientid;	/* constant */
 	nfs4_verifier		cl_confirm;
diff --git a/include/linux/sunrpc/auth.h b/include/linux/sunrpc/auth.h
index a19c3af..3f63218 100644
--- a/include/linux/sunrpc/auth.h
+++ b/include/linux/sunrpc/auth.h
@@ -26,6 +26,7 @@
 	uid_t	uid;
 	gid_t	gid;
 	struct group_info *group_info;
+	unsigned char machine_cred : 1;
 };
 
 /*
@@ -130,6 +131,7 @@
 void __exit		rpc_destroy_generic_auth(void);
 
 struct rpc_cred *	rpc_lookup_cred(void);
+struct rpc_cred *	rpc_lookup_machine_cred(void);
 int			rpcauth_register(const struct rpc_authops *);
 int			rpcauth_unregister(const struct rpc_authops *);
 struct rpc_auth *	rpcauth_create(rpc_authflavor_t, struct rpc_clnt *);
diff --git a/include/linux/sunrpc/auth_gss.h b/include/linux/sunrpc/auth_gss.h
index 67658e1..fec6899 100644
--- a/include/linux/sunrpc/auth_gss.h
+++ b/include/linux/sunrpc/auth_gss.h
@@ -84,6 +84,7 @@
 	enum rpc_gss_svc	gc_service;
 	struct gss_cl_ctx	*gc_ctx;
 	struct gss_upcall_msg	*gc_upcall;
+	unsigned char		gc_machine_cred : 1;
 };
 
 #endif /* __KERNEL__ */