fs/nfsd/state.h - kernel/skids - Git at Google

 /*
  *  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/nfsd/nfsfh.h>
 #include "nfsfh.h"

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

 typedef struct {
 	u32             so_boot;
 	u32             so_stateownerid;
 	u32             so_fileid;
 } stateid_opaque_t;

 typedef struct {
 	u32                     si_generation;
 	stateid_opaque_t        si_opaque;
 } stateid_t;
 #define si_boot           si_opaque.so_boot
 #define si_stateownerid   si_opaque.so_stateownerid
 #define si_fileid         si_opaque.so_fileid

 #define STATEID_FMT	"(%08x/%08x/%08x/%08x)"
 #define STATEID_VAL(s) \
 	(s)->si_boot, \
 	(s)->si_stateownerid, \
 	(s)->si_fileid, \
 	(s)->si_generation

 struct nfsd4_cb_sequence {
 	/* args/res */
 	u32			cbs_minorversion;
 	struct nfs4_client	*cbs_clp;
 };

 struct nfs4_rpc_args {
 	void				*args_op;
 	struct nfsd4_cb_sequence	args_seq;
 };

 struct nfsd4_callback {
 	struct nfs4_rpc_args cb_args;
 	struct work_struct cb_work;
 };

 struct nfs4_delegation {
 	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_client	*dl_client;
 	struct nfs4_file	*dl_file;
 	struct file_lock	*dl_flock;
 	struct file		*dl_vfs_file;
 	u32			dl_type;
 	time_t			dl_time;
 /* For recall: */
 	u32			dl_ident;
 	stateid_t		dl_stateid;
 	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;
 	size_t			cb_addrlen;
 	u32                     cb_prog;
 	u32			cb_minorversion;
 	u32                     cb_ident;	/* minorversion 0 only */
 	struct svc_xprt		*cb_xprt;	/* minorversion 1 only */
 };

 /* 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;
 };

 /* 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_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 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 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 */

 	/* for v4.0 and v4.1 callbacks: */
 	struct nfs4_cb_conn	cl_cb_conn;
 	struct rpc_clnt		*cl_cb_client;
 	atomic_t		cl_cb_set;

 	/* for nfs41 */
 	struct list_head	cl_sessions;
 	struct nfsd4_clid_slot	cl_cs_slot;	/* create_session slot */
 	u32			cl_exchange_flags;
 	struct nfs4_sessionid	cl_sessionid;
 	/* 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;
 	u32			cl_cb_seq_nr;
 	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++;
 }

 /* 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;
 	unsigned		intrp_allocated;
 	struct knfsd_fh		rp_openfh;
 	char			rp_ibuf[NFSD4_REPLAY_ISIZE];
 };

 /*
 * nfs4_stateowner can either be an open_owner, or a lock_owner
 *
 *    so_idhash:  stateid_hashtbl[] for open owner, lockstateid_hashtbl[]
 *         for lock_owner
 *    so_strhash: ownerstr_hashtbl[] for open_owner, lock_ownerstr_hashtbl[]
 *         for lock_owner
 *    so_perclient: nfs4_client->cl_perclient entry - used when nfs4_client
 *         struct is reaped.
 *    so_perfilestate: heads the list of nfs4_stateid (either open or lock)
 *         and is used to ensure no dangling nfs4_stateid references when we
 *         release a stateowner.
 *    so_perlockowner: (open) nfs4_stateid->st_perlockowner entry - used when
 *         close is called to reap associated byte-range locks
 *    so_close_lru: (open) stateowner is placed on this list instead of being
 *         reaped (when so_perfilestate is empty) to hold the last close replay.
 *         reaped by laundramat thread after lease period.
 */
 struct nfs4_stateowner {
 	struct kref		so_ref;
 	struct list_head        so_idhash;   /* hash by so_id */
 	struct list_head        so_strhash;   /* hash by op_name */
 	struct list_head        so_perclient;
 	struct list_head        so_stateids;
 	struct list_head        so_perstateid; /* for lockowners only */
 	struct list_head	so_close_lru; /* tail queue */
 	time_t			so_time; /* time of placement on so_close_lru */
 	int			so_is_open_owner; /* 1=openowner,0=lockowner */
 	u32                     so_id;
 	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 */
 	int                     so_confirmed; /* successful OPEN_CONFIRM? */
 	struct nfs4_replay	so_replay;
 };

 /*
 *  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;
 	struct inode		*fi_inode;
 	u32                     fi_id;      /* used with stateowner->so_id
 					     * for stateid_hashtbl hash */
 	bool			fi_had_conflict;
 };

 /*
 * nfs4_stateid can either be an open stateid or (eventually) a lock stateid
 *
 * (open)nfs4_stateid: one per (open)nfs4_stateowner, nfs4_file
 *
 * 	st_hash: stateid_hashtbl[] entry or lockstateid_hashtbl entry
 * 	st_perfile: file_hashtbl[] entry.
 * 	st_perfile_state: nfs4_stateowner->so_perfilestate
 *       st_perlockowner: (open stateid) list of lock nfs4_stateowners
 * 	st_access_bmap: used only for open stateid
 * 	st_deny_bmap: used only for open stateid
 *	st_openstp: open stateid lock stateid was derived from
 *
 * XXX: open stateids and lock stateids have diverged sufficiently that
 * we should consider defining separate structs for the two cases.
 */

 struct nfs4_stateid {
 	struct list_head              st_hash;
 	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;
 	stateid_t                     st_stateid;
 	struct file                 * st_vfs_file;
 	unsigned long                 st_access_bmap;
 	unsigned long                 st_deny_bmap;
 	struct nfs4_stateid         * st_openstp;
 };

 /* flags for preprocess_seqid_op() */
 #define HAS_SESSION             0x00000001
 #define CONFIRM                 0x00000002
 #define OPEN_STATE              0x00000004
 #define LOCK_STATE              0x00000008
 #define RD_STATE	        0x00000010
 #define WR_STATE	        0x00000020
 #define CLOSE_STATE             0x00000040

 #define seqid_mutating_err(err)                       \
 	(((err) != nfserr_stale_clientid) &&    \
 	((err) != nfserr_bad_seqid) &&          \
 	((err) != nfserr_stale_stateid) &&      \
 	((err) != nfserr_bad_stateid))

 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_stateowner(struct kref *kref);
 extern int set_callback_cred(void);
 extern void nfsd4_probe_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_set_callback_client(struct nfs4_client *, struct rpc_clnt *);
 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(char *recdir_name);
 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 int 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 *);

 static inline void
 nfs4_put_stateowner(struct nfs4_stateowner *so)
 {
 	kref_put(&so->so_ref, nfs4_free_stateowner);
 }

 static inline void
 nfs4_get_stateowner(struct nfs4_stateowner *so)
 {
 	kref_get(&so->so_ref);
 }

 #endif   /* NFSD4_STATE_H */
	/*
	* 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/nfsd/nfsfh.h>
	#include "nfsfh.h"

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

	typedef struct {
	u32 so_boot;
	u32 so_stateownerid;
	u32 so_fileid;
	} stateid_opaque_t;

	typedef struct {
	u32 si_generation;
	stateid_opaque_t si_opaque;
	} stateid_t;
	#define si_boot si_opaque.so_boot
	#define si_stateownerid si_opaque.so_stateownerid
	#define si_fileid si_opaque.so_fileid

	#define STATEID_FMT "(%08x/%08x/%08x/%08x)"
	#define STATEID_VAL(s) \
	(s)->si_boot, \
	(s)->si_stateownerid, \
	(s)->si_fileid, \
	(s)->si_generation

	struct nfsd4_cb_sequence {
	/* args/res */
	u32 cbs_minorversion;
	struct nfs4_client *cbs_clp;
	};

	struct nfs4_rpc_args {
	void *args_op;
	struct nfsd4_cb_sequence args_seq;
	};

	struct nfsd4_callback {
	struct nfs4_rpc_args cb_args;
	struct work_struct cb_work;
	};

	struct nfs4_delegation {
	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_client *dl_client;
	struct nfs4_file *dl_file;
	struct file_lock *dl_flock;
	struct file *dl_vfs_file;
	u32 dl_type;
	time_t dl_time;
	/* For recall: */
	u32 dl_ident;
	stateid_t dl_stateid;
	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;
	size_t cb_addrlen;
	u32 cb_prog;
	u32 cb_minorversion;
	u32 cb_ident; /* minorversion 0 only */
	struct svc_xprt cb_xprt; / minorversion 1 only */
	};

	/* 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;
	};

	/* 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_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 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 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 */

	/* for v4.0 and v4.1 callbacks: */
	struct nfs4_cb_conn cl_cb_conn;
	struct rpc_clnt *cl_cb_client;
	atomic_t cl_cb_set;

	/* for nfs41 */
	struct list_head cl_sessions;
	struct nfsd4_clid_slot cl_cs_slot; /* create_session slot */
	u32 cl_exchange_flags;
	struct nfs4_sessionid cl_sessionid;
	/* 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;
	u32 cl_cb_seq_nr;
	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++;
	}

	/* 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;
	unsigned intrp_allocated;
	struct knfsd_fh rp_openfh;
	char rp_ibuf[NFSD4_REPLAY_ISIZE];
	};

	/*
	* nfs4_stateowner can either be an open_owner, or a lock_owner
	*
	* so_idhash: stateid_hashtbl[] for open owner, lockstateid_hashtbl[]
	* for lock_owner
	* so_strhash: ownerstr_hashtbl[] for open_owner, lock_ownerstr_hashtbl[]
	* for lock_owner
	* so_perclient: nfs4_client->cl_perclient entry - used when nfs4_client
	* struct is reaped.
	* so_perfilestate: heads the list of nfs4_stateid (either open or lock)
	* and is used to ensure no dangling nfs4_stateid references when we
	* release a stateowner.
	* so_perlockowner: (open) nfs4_stateid->st_perlockowner entry - used when
	* close is called to reap associated byte-range locks
	* so_close_lru: (open) stateowner is placed on this list instead of being
	* reaped (when so_perfilestate is empty) to hold the last close replay.
	* reaped by laundramat thread after lease period.
	*/
	struct nfs4_stateowner {
	struct kref so_ref;
	struct list_head so_idhash; /* hash by so_id */
	struct list_head so_strhash; /* hash by op_name */
	struct list_head so_perclient;
	struct list_head so_stateids;
	struct list_head so_perstateid; /* for lockowners only */
	struct list_head so_close_lru; /* tail queue */
	time_t so_time; /* time of placement on so_close_lru */
	int so_is_open_owner; /* 1=openowner,0=lockowner */
	u32 so_id;
	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 */
	int so_confirmed; /* successful OPEN_CONFIRM? */
	struct nfs4_replay so_replay;
	};

	/*
	* 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;
	struct inode *fi_inode;
	u32 fi_id; /* used with stateowner->so_id
	* for stateid_hashtbl hash */
	bool fi_had_conflict;
	};

	/*
	* nfs4_stateid can either be an open stateid or (eventually) a lock stateid
	*
	* (open)nfs4_stateid: one per (open)nfs4_stateowner, nfs4_file
	*
	* st_hash: stateid_hashtbl[] entry or lockstateid_hashtbl entry
	* st_perfile: file_hashtbl[] entry.
	* st_perfile_state: nfs4_stateowner->so_perfilestate
	* st_perlockowner: (open stateid) list of lock nfs4_stateowners
	* st_access_bmap: used only for open stateid
	* st_deny_bmap: used only for open stateid
	* st_openstp: open stateid lock stateid was derived from
	*
	* XXX: open stateids and lock stateids have diverged sufficiently that
	* we should consider defining separate structs for the two cases.
	*/

	struct nfs4_stateid {
	struct list_head st_hash;
	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;
	stateid_t st_stateid;
	struct file * st_vfs_file;
	unsigned long st_access_bmap;
	unsigned long st_deny_bmap;
	struct nfs4_stateid * st_openstp;
	};

	/* flags for preprocess_seqid_op() */
	#define HAS_SESSION 0x00000001
	#define CONFIRM 0x00000002
	#define OPEN_STATE 0x00000004
	#define LOCK_STATE 0x00000008
	#define RD_STATE 0x00000010
	#define WR_STATE 0x00000020
	#define CLOSE_STATE 0x00000040

	#define seqid_mutating_err(err) \
	(((err) != nfserr_stale_clientid) && \
	((err) != nfserr_bad_seqid) && \
	((err) != nfserr_stale_stateid) && \
	((err) != nfserr_bad_stateid))

	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_stateowner(struct kref *kref);
	extern int set_callback_cred(void);
	extern void nfsd4_probe_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_set_callback_client(struct nfs4_client , struct rpc_clnt );
	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(char *recdir_name);
	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 int 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 *);

	static inline void
	nfs4_put_stateowner(struct nfs4_stateowner *so)
	{
	kref_put(&so->so_ref, nfs4_free_stateowner);
	}

	static inline void
	nfs4_get_stateowner(struct nfs4_stateowner *so)
	{
	kref_get(&so->so_ref);
	}

	#endif /* NFSD4_STATE_H */