/*

   *  Copyright (c) 2001 The Regents of the University of Michigan.
   *  All rights reserved.
   *
   *  Kendrick Smith <kmsmith@umich.edu>
   *  Andy Adamson <andros@umich.edu>
   *  
   *  Redistribution and use in source and binary forms, with or without
   *  modification, are permitted provided that the following conditions
   *  are met:
   *  
   *  1. Redistributions of source code must retain the above copyright
   *     notice, this list of conditions and the following disclaimer.
   *  2. Redistributions in binary form must reproduce the above copyright
   *     notice, this list of conditions and the following disclaimer in the
   *     documentation and/or other materials provided with the distribution.
   *  3. Neither the name of the University nor the names of its
   *     contributors may be used to endorse or promote products derived
   *     from this software without specific prior written permission.
   *
   *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
   *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
   *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
   *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
   *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
   *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
   *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
   *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
   *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   *
   */
  
  #ifndef _NFSD4_STATE_H
  #define _NFSD4_STATE_H

  #include <linux/idr.h>

  #include <linux/sunrpc/svc_xprt.h>

  #include <linux/nfsd/nfsfh.h>

  #include "nfsfh.h"

  typedef struct {
  	u32             cl_boot;
  	u32             cl_id;
  } clientid_t;
  
  typedef struct {

  	clientid_t	so_clid;
  	u32		so_id;

  } stateid_opaque_t;
  
  typedef struct {
  	u32                     si_generation;
  	stateid_opaque_t        si_opaque;
  } stateid_t;

  #define STATEID_FMT	"(%08x/%08x/%08x/%08x)"
  #define STATEID_VAL(s) \

  	(s)->si_opaque.so_clid.cl_boot, \
  	(s)->si_opaque.so_clid.cl_id, \
  	(s)->si_opaque.so_id, \

  	(s)->si_generation

  struct nfsd4_callback {

  	void *cb_op;
  	struct nfs4_client *cb_clp;

  	struct list_head cb_per_client;

  	u32 cb_minorversion;

  	struct rpc_message cb_msg;
  	const struct rpc_call_ops *cb_ops;

  	struct work_struct cb_work;

  	bool cb_done;

  };

  struct nfs4_stid {
  #define NFS4_OPEN_STID 1
  #define NFS4_LOCK_STID 2
  #define NFS4_DELEG_STID 4

  /* For an open stateid kept around *only* to process close replays: */
  #define NFS4_CLOSED_STID 8
  	unsigned char sc_type;

  	stateid_t sc_stateid;

  	struct nfs4_client *sc_client;

  };

  struct nfs4_delegation {

  	struct nfs4_stid	dl_stid; /* must be first field */

  	struct list_head	dl_perfile;
  	struct list_head	dl_perclnt;

  	struct list_head	dl_recall_lru;  /* delegation recalled */
  	atomic_t		dl_count;       /* ref count */

  	struct nfs4_file	*dl_file;

  	u32			dl_type;
  	time_t			dl_time;

  /* For recall: */

  	struct knfsd_fh		dl_fh;

  	int			dl_retries;

  	struct nfsd4_callback	dl_recall;

  };

  /* client delegation callback info */

  struct nfs4_cb_conn {

  	/* SETCLIENTID info */

  	struct sockaddr_storage	cb_addr;

  	struct sockaddr_storage	cb_saddr;

  	size_t			cb_addrlen;

  	u32                     cb_prog; /* used only in 4.0 case;
  					    per-session otherwise */

  	u32                     cb_ident;	/* minorversion 0 only */

  	struct svc_xprt		*cb_xprt;	/* minorversion 1 only */

  };

  static inline struct nfs4_delegation *delegstateid(struct nfs4_stid *s)
  {
  	return container_of(s, struct nfs4_delegation, dl_stid);
  }

  /* Maximum number of slots per session. 160 is useful for long haul TCP */
  #define NFSD_MAX_SLOTS_PER_SESSION     160

  /* Maximum number of operations per session compound */
  #define NFSD_MAX_OPS_PER_COMPOUND	16

  /* Maximum  session per slot cache size */
  #define NFSD_SLOT_CACHE_SIZE		1024

  /* Maximum number of NFSD_SLOT_CACHE_SIZE slots per session */
  #define NFSD_CACHE_SIZE_SLOTS_PER_SESSION	32
  #define NFSD_MAX_MEM_PER_SESSION  \
  		(NFSD_CACHE_SIZE_SLOTS_PER_SESSION * NFSD_SLOT_CACHE_SIZE)

  struct nfsd4_slot {

  	bool	sl_inuse;
  	bool	sl_cachethis;
  	u16	sl_opcnt;
  	u32	sl_seqid;
  	__be32	sl_status;
  	u32	sl_datalen;
  	char	sl_data[];

  };

  struct nfsd4_channel_attrs {
  	u32		headerpadsz;
  	u32		maxreq_sz;
  	u32		maxresp_sz;
  	u32		maxresp_cached;
  	u32		maxops;
  	u32		maxreqs;
  	u32		nr_rdma_attrs;
  	u32		rdma_attrs;
  };

  struct nfsd4_create_session {
  	clientid_t			clientid;
  	struct nfs4_sessionid		sessionid;
  	u32				seqid;
  	u32				flags;
  	struct nfsd4_channel_attrs	fore_channel;
  	struct nfsd4_channel_attrs	back_channel;
  	u32				callback_prog;
  	u32				uid;
  	u32				gid;
  };

  struct nfsd4_bind_conn_to_session {
  	struct nfs4_sessionid		sessionid;
  	u32				dir;
  };

  /* The single slot clientid cache structure */
  struct nfsd4_clid_slot {
  	u32				sl_seqid;
  	__be32				sl_status;
  	struct nfsd4_create_session	sl_cr_ses;
  };

  struct nfsd4_conn {
  	struct list_head cn_persession;
  	struct svc_xprt *cn_xprt;

  	struct svc_xpt_user cn_xpt_user;
  	struct nfsd4_session *cn_session;

  /* CDFC4_FORE, CDFC4_BACK: */
  	unsigned char cn_flags;
  };

  struct nfsd4_session {
  	struct kref		se_ref;
  	struct list_head	se_hash;	/* hash by sessionid */
  	struct list_head	se_perclnt;
  	u32			se_flags;

  	struct nfs4_client	*se_client;

  	struct nfs4_sessionid	se_sessionid;

  	struct nfsd4_channel_attrs se_fchannel;
  	struct nfsd4_channel_attrs se_bchannel;

  	struct list_head	se_conns;

  	u32			se_cb_prog;

  	u32			se_cb_seq_nr;

  	struct nfsd4_slot	*se_slots[];	/* forward channel slots */

  };
  
  static inline void
  nfsd4_put_session(struct nfsd4_session *ses)
  {
  	extern void free_session(struct kref *kref);
  	kref_put(&ses->se_ref, free_session);
  }
  
  static inline void
  nfsd4_get_session(struct nfsd4_session *ses)
  {
  	kref_get(&ses->se_ref);
  }

  /* formatted contents of nfs4_sessionid */
  struct nfsd4_sessionid {
  	clientid_t	clientid;
  	u32		sequence;
  	u32		reserved;
  };

  #define HEXDIR_LEN     33 /* hex version of 16 byte md5 of cl_name plus '\0' */

  /*
   * struct nfs4_client - one per client.  Clientids live here.
   * 	o Each nfs4_client is hashed by clientid.
   *
   * 	o Each nfs4_clients is also hashed by name 
   * 	  (the opaque quantity initially sent by the client to identify itself).
   * 	  
   *	o cl_perclient list is used to ensure no dangling stateowner references
   *	  when we expire the nfs4_client
   */
  struct nfs4_client {
  	struct list_head	cl_idhash; 	/* hash by cl_clientid.id */
  	struct list_head	cl_strhash; 	/* hash by cl_name */

  	struct list_head	cl_openowners;

  	struct idr		cl_stateids;	/* stateid lookup */

  	struct list_head	cl_delegations;

  	struct list_head        cl_lru;         /* tail queue */
  	struct xdr_netobj	cl_name; 	/* id generated by client */

  	char                    cl_recdir[HEXDIR_LEN]; /* recovery dir */

  	nfs4_verifier		cl_verifier; 	/* generated by client */
  	time_t                  cl_time;        /* time of last lease renewal */

  	struct sockaddr_storage	cl_addr; 	/* client ipaddress */

  	u32			cl_flavor;	/* setclientid pseudoflavor */

  	char			*cl_principal;	/* setclientid principal name */

  	struct svc_cred		cl_cred; 	/* setclientid principal */
  	clientid_t		cl_clientid;	/* generated by server */
  	nfs4_verifier		cl_confirm;	/* generated by server */

  	u32			cl_firststate;	/* recovery dir creation */

  	u32			cl_minorversion;

  	/* for v4.0 and v4.1 callbacks: */
  	struct nfs4_cb_conn	cl_cb_conn;

  #define NFSD4_CLIENT_CB_UPDATE	1
  #define NFSD4_CLIENT_KILL	2
  	unsigned long		cl_cb_flags;

  	struct rpc_clnt		*cl_cb_client;

  	u32			cl_cb_ident;

  #define NFSD4_CB_UP		0
  #define NFSD4_CB_UNKNOWN	1
  #define NFSD4_CB_DOWN		2

  #define NFSD4_CB_FAULT		3

  	int			cl_cb_state;

  	struct nfsd4_callback	cl_cb_null;

  	struct nfsd4_session	*cl_cb_session;

  	struct list_head	cl_callbacks; /* list of in-progress callbacks */

  	/* for all client information that callback code might need: */
  	spinlock_t		cl_lock;

  	/* for nfs41 */
  	struct list_head	cl_sessions;

  	struct nfsd4_clid_slot	cl_cs_slot;	/* create_session slot */

  	u32			cl_exchange_flags;

  	/* number of rpc's in progress over an associated session: */
  	atomic_t		cl_refcount;

  
  	/* for nfs41 callbacks */

  	/* We currently support a single back channel with a single slot */
  	unsigned long		cl_cb_slot_busy;

  	struct rpc_wait_queue	cl_cb_waitq;	/* backchannel callers may */
  						/* wait here for slots */

  };

  static inline void
  mark_client_expired(struct nfs4_client *clp)
  {
  	clp->cl_time = 0;
  }
  
  static inline bool
  is_client_expired(struct nfs4_client *clp)
  {
  	return clp->cl_time == 0;
  }

  /* struct nfs4_client_reset
   * one per old client. Populates reset_str_hashtbl. Filled from conf_id_hashtbl
   * upon lease reset, or from upcall to state_daemon (to read in state
   * from non-volitile storage) upon reboot.
   */
  struct nfs4_client_reclaim {
  	struct list_head	cr_strhash;	/* hash by cr_name */

  	char			cr_recdir[HEXDIR_LEN]; /* recover dir */

  };
  
  static inline void
  update_stateid(stateid_t *stateid)
  {
  	stateid->si_generation++;

  	/* Wraparound recommendation from 3530bis-13 9.1.3.2: */
  	if (stateid->si_generation == 0)
  		stateid->si_generation = 1;

  }
  
  /* A reasonable value for REPLAY_ISIZE was estimated as follows:  
   * The OPEN response, typically the largest, requires 
   *   4(status) + 8(stateid) + 20(changeinfo) + 4(rflags) +  8(verifier) + 
   *   4(deleg. type) + 8(deleg. stateid) + 4(deleg. recall flag) + 
   *   20(deleg. space limit) + ~32(deleg. ace) = 112 bytes 
   */
  
  #define NFSD4_REPLAY_ISIZE       112 
  
  /*
   * Replay buffer, where the result of the last seqid-mutating operation 
   * is cached. 
   */
  struct nfs4_replay {

  	__be32			rp_status;

  	unsigned int		rp_buflen;
  	char			*rp_buf;

  	struct knfsd_fh		rp_openfh;

  	char			rp_ibuf[NFSD4_REPLAY_ISIZE];
  };

  struct nfs4_stateowner {

  	struct list_head        so_strhash;   /* hash by op_name */

  	struct list_head        so_stateids;

  	struct nfs4_client *    so_client;

  	/* after increment in ENCODE_SEQID_OP_TAIL, represents the next
  	 * sequence id expected from the client: */
  	u32                     so_seqid;

  	struct xdr_netobj       so_owner;     /* open owner name */

  	struct nfs4_replay	so_replay;

  	bool			so_is_open_owner;

  };

  struct nfs4_openowner {
  	struct nfs4_stateowner	oo_owner; /* must be first field */
  	struct list_head        oo_perclient;

  	/*
  	 * We keep around openowners a little while after last close,
  	 * which saves clients from having to confirm, and allows us to
  	 * handle close replays if they come soon enough.  The close_lru
  	 * is a list of such openowners, to be reaped by the laundromat
  	 * thread eventually if they remain unused:
  	 */
  	struct list_head	oo_close_lru;

  	struct nfs4_ol_stateid *oo_last_closed_stid;

  	time_t			oo_time; /* time of placement on so_close_lru */

  #define NFS4_OO_CONFIRMED   1

  #define NFS4_OO_PURGE_CLOSE 2

  #define NFS4_OO_NEW         4

  	unsigned char		oo_flags;

  };
  
  struct nfs4_lockowner {
  	struct nfs4_stateowner	lo_owner; /* must be first element */

  	struct list_head	lo_owner_ino_hash; /* hash by owner,file */

  	struct list_head        lo_perstateid; /* for lockowners only */
  	struct list_head	lo_list; /* for temporary uses */
  };
  
  static inline struct nfs4_openowner * openowner(struct nfs4_stateowner *so)
  {
  	return container_of(so, struct nfs4_openowner, oo_owner);
  }
  
  static inline struct nfs4_lockowner * lockowner(struct nfs4_stateowner *so)
  {
  	return container_of(so, struct nfs4_lockowner, lo_owner);
  }

  /*
  *  nfs4_file: a file opened by some number of (open) nfs4_stateowners.
  *    o fi_perfile list is used to search for conflicting 
  *      share_acces, share_deny on the file.
  */
  struct nfs4_file {

  	atomic_t		fi_ref;

  	struct list_head        fi_hash;    /* hash by "struct inode *" */

  	struct list_head        fi_stateids;
  	struct list_head	fi_delegations;

  	/* One each for O_RDONLY, O_WRONLY, O_RDWR: */
  	struct file *		fi_fds[3];

  	/*

  	 * Each open or lock stateid contributes 0-4 to the counts
  	 * below depending on which bits are set in st_access_bitmap:
  	 *     1 to fi_access[O_RDONLY] if NFS4_SHARE_ACCES_READ is set
  	 *   + 1 to fi_access[O_WRONLY] if NFS4_SHARE_ACCESS_WRITE is set
  	 *   + 1 to both of the above if NFS4_SHARE_ACCESS_BOTH is set.

  	 */

  	atomic_t		fi_access[2];

  	struct file		*fi_deleg_file;
  	struct file_lock	*fi_lease;
  	atomic_t		fi_delegees;

  	struct inode		*fi_inode;

  	bool			fi_had_conflict;

  };

  /* XXX: for first cut may fall back on returning file that doesn't work
   * at all? */
  static inline struct file *find_writeable_file(struct nfs4_file *f)
  {

  	if (f->fi_fds[O_WRONLY])
  		return f->fi_fds[O_WRONLY];
  	return f->fi_fds[O_RDWR];

  }
  
  static inline struct file *find_readable_file(struct nfs4_file *f)
  {

  	if (f->fi_fds[O_RDONLY])
  		return f->fi_fds[O_RDONLY];
  	return f->fi_fds[O_RDWR];

  }
  
  static inline struct file *find_any_file(struct nfs4_file *f)
  {
  	if (f->fi_fds[O_RDWR])
  		return f->fi_fds[O_RDWR];

  	else if (f->fi_fds[O_WRONLY])

  		return f->fi_fds[O_WRONLY];
  	else
  		return f->fi_fds[O_RDONLY];
  }

  /* "ol" stands for "Open or Lock".  Better suggestions welcome. */

  struct nfs4_ol_stateid {

  	struct nfs4_stid    st_stid; /* must be first field */

  	struct list_head              st_perfile;

  	struct list_head              st_perstateowner;
  	struct list_head              st_lockowners;

  	struct nfs4_stateowner      * st_stateowner;
  	struct nfs4_file            * st_file;

  	unsigned long                 st_access_bmap;
  	unsigned long                 st_deny_bmap;

  	struct nfs4_ol_stateid         * st_openstp;

  };

  static inline struct nfs4_ol_stateid *openlockstateid(struct nfs4_stid *s)
  {
  	return container_of(s, struct nfs4_ol_stateid, st_stid);
  }

  /* flags for preprocess_seqid_op() */

  #define RD_STATE	        0x00000010
  #define WR_STATE	        0x00000020

  struct nfsd4_compound_state;
  
  extern __be32 nfs4_preprocess_stateid_op(struct nfsd4_compound_state *cstate,

  		stateid_t *stateid, int flags, struct file **filp);

  extern void nfs4_lock_state(void);
  extern void nfs4_unlock_state(void);
  extern int nfs4_in_grace(void);

  extern __be32 nfs4_check_open_reclaim(clientid_t *clid);

  extern void nfs4_free_openowner(struct nfs4_openowner *);
  extern void nfs4_free_lockowner(struct nfs4_lockowner *);

  extern int set_callback_cred(void);

  extern void nfsd4_probe_callback(struct nfs4_client *clp);

  extern void nfsd4_probe_callback_sync(struct nfs4_client *clp);

  extern void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *);

  extern void nfsd4_do_callback_rpc(struct work_struct *);

  extern void nfsd4_cb_recall(struct nfs4_delegation *dp);

  extern int nfsd4_create_callback_queue(void);
  extern void nfsd4_destroy_callback_queue(void);

  extern void nfsd4_shutdown_callback(struct nfs4_client *);

  extern void nfs4_put_delegation(struct nfs4_delegation *dp);

  extern __be32 nfs4_make_rec_clidname(char *clidname, struct xdr_netobj *clname);

  extern void nfsd4_init_recdir(void);

  extern int nfsd4_recdir_load(void);
  extern void nfsd4_shutdown_recdir(void);
  extern int nfs4_client_to_reclaim(const char *name);

  extern int nfs4_has_reclaimed_state(const char *name, bool use_exchange_id);

  extern void nfsd4_recdir_purge_old(void);

  extern void nfsd4_create_clid_dir(struct nfs4_client *clp);

  extern void nfsd4_remove_clid_dir(struct nfs4_client *clp);

  extern void release_session_client(struct nfsd4_session *);

  extern __be32 nfs4_validate_stateid(struct nfs4_client *, stateid_t *);

  extern void nfsd4_purge_closed_stateid(struct nfs4_stateowner *);

  #endif   /* NFSD4_STATE_H */