sunrpc: add generic_auth hash_cred() function

Add a hash_cred() function for generic_auth, using both the
uid and gid from the auth_cred.
Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>

net/sunrpc/auth_generic.c

@@ -78,6 +78,14 @@ static struct rpc_cred *generic_bind_cred(struct rpc_task *task,
 	return auth->au_ops->lookup_cred(auth, acred, lookupflags);
 }
 
+static int
+generic_hash_cred(struct auth_cred *acred, unsigned int hashbits)
+{
+	return hash_64(from_kgid(&init_user_ns, acred->gid) |
+		((u64)from_kuid(&init_user_ns, acred->uid) <<
+			(sizeof(gid_t) * 8)), hashbits);
+}
+
 /*
  * Lookup generic creds for current process
  */
@@ -258,6 +266,7 @@ generic_key_timeout(struct rpc_auth *auth, struct rpc_cred *cred)
 static const struct rpc_authops generic_auth_ops = {
 	.owner = THIS_MODULE,
 	.au_name = "Generic",
+	.hash_cred = generic_hash_cred,
 	.lookup_cred = generic_lookup_cred,
 	.crcreate = generic_create_cred,
 	.key_timeout = generic_key_timeout,