/*
 * linux/fs/nfs/nfs4_fs.h
 *
 * Copyright (C) 2005 Trond Myklebust
 *
 * NFSv4-specific filesystem definitions and declarations
 */

#ifndef __LINUX_FS_NFS_NFS4_FS_H
#define __LINUX_FS_NFS_NFS4_FS_H

#ifdef CONFIG_NFS_V4

struct idmap;

/*
 * In a seqid-mutating op, this macro controls which error return
 * values trigger incrementation of the seqid.
 *
 * from rfc 3010:
 * The client MUST monotonically increment the sequence number for the
 * CLOSE, LOCK, LOCKU, OPEN, OPEN_CONFIRM, and OPEN_DOWNGRADE
 * operations.  This is true even in the event that the previous
 * operation that used the sequence number received an error.  The only
 * exception to this rule is if the previous operation received one of
 * the following errors: NFSERR_STALE_CLIENTID, NFSERR_STALE_STATEID,
 * NFSERR_BAD_STATEID, NFSERR_BAD_SEQID, NFSERR_BADXDR,
 * NFSERR_RESOURCE, NFSERR_NOFILEHANDLE.
 *
 */
#define seqid_mutating_err(err)       \
(((err) != NFSERR_STALE_CLIENTID) &&  \
 ((err) != NFSERR_STALE_STATEID)  &&  \
 ((err) != NFSERR_BAD_STATEID)    &&  \
 ((err) != NFSERR_BAD_SEQID)      &&  \
 ((err) != NFSERR_BAD_XDR)        &&  \
 ((err) != NFSERR_RESOURCE)       &&  \
 ((err) != NFSERR_NOFILEHANDLE))

enum nfs4_client_state {
	NFS4CLNT_MANAGER_RUNNING  = 0,
	NFS4CLNT_CHECK_LEASE,
	NFS4CLNT_LEASE_EXPIRED,
	NFS4CLNT_RECLAIM_REBOOT,
	NFS4CLNT_RECLAIM_NOGRACE,
	NFS4CLNT_DELEGRETURN,
	NFS4CLNT_LAYOUTRECALL,
	NFS4CLNT_SESSION_RESET,
	NFS4CLNT_RECALL_SLOT,
	NFS4CLNT_LEASE_CONFIRM,
};

enum nfs4_session_state {
	NFS4_SESSION_INITING,
	NFS4_SESSION_DRAINING,
};

struct nfs4_minor_version_ops {
	u32	minor_version;

	int	(*call_sync)(struct rpc_clnt *clnt,
			struct nfs_server *server,
			struct rpc_message *msg,
			struct nfs4_sequence_args *args,
			struct nfs4_sequence_res *res,
			int cache_reply);
	int	(*validate_stateid)(struct nfs_delegation *,
			const nfs4_stateid *);
	const struct nfs4_state_recovery_ops *reboot_recovery_ops;
	const struct nfs4_state_recovery_ops *nograce_recovery_ops;
	const struct nfs4_state_maintenance_ops *state_renewal_ops;
};

/*
 * struct rpc_sequence ensures that RPC calls are sent in the exact
 * order that they appear on the list.
 */
struct rpc_sequence {
	struct rpc_wait_queue	wait;	/* RPC call delay queue */
	spinlock_t lock;		/* Protects the list */
	struct list_head list;		/* Defines sequence of RPC calls */
};

#define NFS_SEQID_CONFIRMED 1
struct nfs_seqid_counter {
	struct rpc_sequence *sequence;
	int flags;
	u32 counter;
};

struct nfs_seqid {
	struct nfs_seqid_counter *sequence;
	struct list_head list;
};

static inline void nfs_confirm_seqid(struct nfs_seqid_counter *seqid, int status)
{
	if (seqid_mutating_err(-status))
		seqid->flags |= NFS_SEQID_CONFIRMED;
}

struct nfs_unique_id {
	struct rb_node rb_node;
	__u64 id;
};

/*
 * NFS4 state_owners and lock_owners are simply labels for ordered
 * sequences of RPC calls. Their sole purpose is to provide once-only
 * semantics by allowing the server to identify replayed requests.
 */
struct nfs4_state_owner {
	struct nfs_unique_id so_owner_id;
	struct nfs_server    *so_server;
	struct rb_node	     so_server_node;

	struct rpc_cred	     *so_cred;	 /* Associated cred */

	spinlock_t	     so_lock;
	atomic_t	     so_count;
	unsigned long	     so_flags;
	struct list_head     so_states;
	struct nfs_seqid_counter so_seqid;
	struct rpc_sequence  so_sequence;
};

enum {
	NFS_OWNER_RECLAIM_REBOOT,
	NFS_OWNER_RECLAIM_NOGRACE
};

#define NFS_LOCK_NEW		0
#define NFS_LOCK_RECLAIM	1
#define NFS_LOCK_EXPIRED	2

/*
 * struct nfs4_state maintains the client-side state for a given
 * (state_owner,inode) tuple (OPEN) or state_owner (LOCK).
 *
 * OPEN: