SUNRPC: RPC client should retry with different versions of rpcbind

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/Kconfig b/fs/Kconfig
index a42f767..20bec77 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -1734,6 +1734,18 @@
 config SUNRPC_GSS
 	tristate
 
+config SUNRPC_BIND34
+	bool "Support for rpcbind versions 3 & 4 (EXPERIMENTAL)"
+	depends on SUNRPC && EXPERIMENTAL
+	help
+	  Provides kernel support for querying rpcbind servers via versions 3
+	  and 4 of the rpcbind protocol.  The kernel automatically falls back
+	  to version 2 if a remote rpcbind service does not support versions
+	  3 or 4.
+
+	  If unsure, say N to get traditional behavior (version 2 rpcbind
+	  requests only).
+
 config RPCSEC_GSS_KRB5
 	tristate "Secure RPC: Kerberos V mechanism (EXPERIMENTAL)"
 	depends on SUNRPC && EXPERIMENTAL