NFSD: Add an RPC authflavor tracepoint display helper

To be used in subsequent patches.
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

fs/nfsd/trace.h

@@ -841,6 +841,22 @@ DEFINE_NFSD_CB_EVENT(setup);
 DEFINE_NFSD_CB_EVENT(state);
 DEFINE_NFSD_CB_EVENT(shutdown);
 
+TRACE_DEFINE_ENUM(RPC_AUTH_NULL);
+TRACE_DEFINE_ENUM(RPC_AUTH_UNIX);
+TRACE_DEFINE_ENUM(RPC_AUTH_GSS);
+TRACE_DEFINE_ENUM(RPC_AUTH_GSS_KRB5);
+TRACE_DEFINE_ENUM(RPC_AUTH_GSS_KRB5I);
+TRACE_DEFINE_ENUM(RPC_AUTH_GSS_KRB5P);
+
+#define show_nfsd_authflavor(val)					\
+	__print_symbolic(val,						\
+		{ RPC_AUTH_NULL,		"none" },		\
+		{ RPC_AUTH_UNIX,		"sys" },		\
+		{ RPC_AUTH_GSS,			"gss" },		\
+		{ RPC_AUTH_GSS_KRB5,		"krb5" },		\
+		{ RPC_AUTH_GSS_KRB5I,		"krb5i" },		\
+		{ RPC_AUTH_GSS_KRB5P,		"krb5p" })
+
 TRACE_EVENT(nfsd_cb_setup_err,
 	TP_PROTO(
 		const struct nfs4_client *clp,