struct cb_process_state *cps);
extern __be32 nfs4_callback_recall(struct cb_recallargs *args, void *dummy,
struct cb_process_state *cps);
-#ifdef CONFIG_NFS_V4
+#if IS_ENABLED(CONFIG_NFS_V4)
extern int nfs_callback_up(u32 minorversion, struct rpc_xprt *xprt);
extern void nfs_callback_down(int minorversion);
extern int nfs4_validate_delegation_stateid(struct nfs_delegation *delegation,