SUNRPC: Add a callback to initialise server requests

Add a callback to help initialise server requests before they are
processed. This will allow us to clean up the NFS server version
support, and to make it container safe.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>

fs/nfs/callback.c

@@ -457,4 +457,5 @@ static struct svc_program nfs4_callback_program = {
 	.pg_class = "nfs",				/* authentication class */
 	.pg_stats = &nfs4_callback_stats,
 	.pg_authenticate = nfs_callback_authenticate,
+	.pg_init_request = svc_generic_init_request,
 };