include/linux/lockd/bind.h

/* 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

struct file_lock;
struct nfs_fh;
struct svc_rqst;
struct rpc_task;
struct rpc_clnt;
struct super_block;
struct module;

/**
 * struct nlmsvc_binding - lockd -> nfsd callback table
 * @owner:  module that provides this binding.
 * @fopen:  open a file by NFS file handle on behalf of an NLM request.
 * @fclose: close a file that was previously opened via @fopen.
 *          Implementations MUST be semantically equivalent to fput().
 */
struct nlmsvc_binding {
	struct module	*owner;
	int		(*fopen)(struct svc_rqst *rqstp, struct nfs_fh *f,
				 struct file **filp, int flags);
	void		(*fclose)(struct file *filp);
};

extern const struct nlmsvc_binding __rcu *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;
	const struct cred	*cred;
};

/*
 * 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);
extern struct rpc_clnt *nlmclnt_rpc_clnt(struct nlm_host *host);
extern void	nlmclnt_shutdown_rpc_clnt(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, const struct cred *cred);
extern void	lockd_down(struct net *net);

/*
 * Cluster failover support
 */
int nlmsvc_unlock_all_by_sb(struct super_block *sb);
int nlmsvc_unlock_all_by_ip(struct sockaddr *server_addr);

#endif /* LINUX_LOCKD_BIND_H */