v4.19.13 snapshot.
diff --git a/include/linux/lockd/bind.h b/include/linux/lockd/bind.h
new file mode 100644
index 0000000..053a4ef
--- /dev/null
+++ b/include/linux/lockd/bind.h
@@ -0,0 +1,81 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * linux/include/linux/lockd/bind.h
+ *
+ * This is the part of lockd visible to nfsd and the nfs client.
+ *
+ * Copyright (C) 1996, Olaf Kirch <okir@monad.swb.de>
+ */
+
+#ifndef LINUX_LOCKD_BIND_H
+#define LINUX_LOCKD_BIND_H
+
+#include <linux/lockd/nlm.h>
+/* need xdr-encoded error codes too, so... */
+#include <linux/lockd/xdr.h>
+#ifdef CONFIG_LOCKD_V4
+#include <linux/lockd/xdr4.h>
+#endif
+
+/* Dummy declarations */
+struct svc_rqst;
+struct rpc_task;
+
+/*
+ * This is the set of functions for lockd->nfsd communication
+ */
+struct nlmsvc_binding {
+ __be32 (*fopen)(struct svc_rqst *,
+ struct nfs_fh *,
+ struct file **);
+ void (*fclose)(struct file *);
+};
+
+extern const struct nlmsvc_binding *nlmsvc_ops;
+
+/*
+ * Similar to nfs_client_initdata, but without the NFS-specific
+ * rpc_ops field.
+ */
+struct nlmclnt_initdata {
+ const char *hostname;
+ const struct sockaddr *address;
+ size_t addrlen;
+ unsigned short protocol;
+ u32 nfs_version;
+ int noresvport;
+ struct net *net;
+ const struct nlmclnt_operations *nlmclnt_ops;
+};
+
+/*
+ * Functions exported by the lockd module
+ */
+
+extern struct nlm_host *nlmclnt_init(const struct nlmclnt_initdata *nlm_init);
+extern void nlmclnt_done(struct nlm_host *host);
+
+/*
+ * NLM client operations provide a means to modify RPC processing of NLM
+ * requests. Callbacks receive a pointer to data passed into the call to
+ * nlmclnt_proc().
+ */
+struct nlmclnt_operations {
+ /* Called on successful allocation of nlm_rqst, use for allocation or
+ * reference counting. */
+ void (*nlmclnt_alloc_call)(void *);
+
+ /* Called in rpc_task_prepare for unlock. A return value of true
+ * indicates the callback has put the task to sleep on a waitqueue
+ * and NLM should not call rpc_call_start(). */
+ bool (*nlmclnt_unlock_prepare)(struct rpc_task*, void *);
+
+ /* Called when the nlm_rqst is freed, callbacks should clean up here */
+ void (*nlmclnt_release_call)(void *);
+};
+
+extern int nlmclnt_proc(struct nlm_host *host, int cmd, struct file_lock *fl, void *data);
+extern int lockd_up(struct net *net);
+extern void lockd_down(struct net *net);
+
+#endif /* LINUX_LOCKD_BIND_H */