text: /* SPDX-License-Identifier: GPL-2.0 */
  /*
   * 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
  
  #if defined(CONFIG_NFS_V4_2)
  #define NFS4_MAX_MINOR_VERSION 2
  #elif defined(CONFIG_NFS_V4_1)
  #define NFS4_MAX_MINOR_VERSION 1
  #else
  #define NFS4_MAX_MINOR_VERSION 0
  #endif
  
  #if IS_ENABLED(CONFIG_NFS_V4)
  
  #define NFS4_MAX_LOOP_ON_RECOVER (10)
  
  #include <linux/seqlock.h>
  
  struct idmap;
  
  enum nfs4_client_state {
  	NFS4CLNT_MANAGER_RUNNING  = 0,
  	NFS4CLNT_CHECK_LEASE,
  	NFS4CLNT_LEASE_EXPIRED,
  	NFS4CLNT_RECLAIM_REBOOT,
  	NFS4CLNT_RECLAIM_NOGRACE,
  	NFS4CLNT_DELEGRETURN,
  	NFS4CLNT_SESSION_RESET,
  	NFS4CLNT_LEASE_CONFIRM,
  	NFS4CLNT_SERVER_SCOPE_MISMATCH,
  	NFS4CLNT_PURGE_STATE,
  	NFS4CLNT_BIND_CONN_TO_SESSION,
  	NFS4CLNT_MOVED,
  	NFS4CLNT_LEASE_MOVED,
  	NFS4CLNT_DELEGATION_EXPIRED,
  	NFS4CLNT_RUN_MANAGER,
  	NFS4CLNT_DELEGRETURN_RUNNING,
  };
  
  #define NFS4_RENEW_TIMEOUT		0x01
  #define NFS4_RENEW_DELEGATION_CB	0x02
  
  struct nfs_seqid_counter;
  struct nfs4_minor_version_ops {
  	u32	minor_version;
  	unsigned init_caps;
  
  	int	(*init_client)(struct nfs_client *);
  	void	(*shutdown_client)(struct nfs_client *);
  	bool	(*match_stateid)(const nfs4_stateid *,
  			const nfs4_stateid *);
  	int	(*find_root_sec)(struct nfs_server *, struct nfs_fh *,
  			struct nfs_fsinfo *);
  	void	(*free_lock_state)(struct nfs_server *,
  			struct nfs4_lock_state *);
  	int	(*test_and_free_expired)(struct nfs_server *,
  			nfs4_stateid *, const struct cred *);
  	struct nfs_seqid *
  		(*alloc_seqid)(struct nfs_seqid_counter *, gfp_t);
  	void	(*session_trunk)(struct rpc_clnt *clnt,
  			struct rpc_xprt *xprt, void *data);
  	const struct rpc_call_ops *call_sync_ops;
  	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;
  	const struct nfs4_mig_recovery_ops *mig_recovery_ops;
  };
  
  #define NFS_SEQID_CONFIRMED 1
  struct nfs_seqid_counter {
  	ktime_t create_time;
  	int owner_id;
  	int flags;
  	u32 counter;
  	spinlock_t lock;		/* Protects the list */
  	struct list_head list;		/* Defines sequence of RPC calls */
  	struct rpc_wait_queue	wait;	/* RPC call delay queue */
  };
  
  struct nfs_seqid {
  	struct nfs_seqid_counter *sequence;
  	struct list_head list;
  	struct rpc_task *task;
  };
  
  static inline void nfs_confirm_seqid(struct nfs_seqid_counter *seqid, int status)
  {
  	if (seqid_mutating_err(-status))
  		seqid->flags |= NFS_SEQID_CONFIRMED;
  }
  
  /*
   * 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_server    *so_server;
  	struct list_head     so_lru;
  	unsigned long        so_expires;
  	struct rb_node	     so_server_node;
  
  	const struct 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;
  	seqcount_t	     so_reclaim_seqcount;
  	struct mutex	     so_delegreturn_mutex;
  };
  
  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:
   * In order to know when to OPEN_DOWNGRADE or CLOSE the state on the server,
   * we need to know how many files are open for reading or writing on a
   * given inode. This information too is stored here.
   *
   * LOCK: one nfs4_state (LOCK) to hold the lock stateid nfs4_state(OPEN)
   */
  
  struct nfs4_lock_state {
  	struct list_head	ls_locks;	/* Other lock stateids */
  	struct nfs4_state *	ls_state;	/* Pointer to open state */
  #define NFS_LOCK_INITIALIZED 0
  #define NFS_LOCK_LOST        1
  	unsigned long		ls_flags;
  	struct nfs_seqid_counter	ls_seqid;
  	nfs4_stateid		ls_stateid;
  	refcount_t		ls_count;
  	fl_owner_t		ls_owner;
  };
  
  /* bits for nfs4_state->flags */
  enum {
  	LK_STATE_IN_USE,
  	NFS_DELEGATED_STATE,		/* Current stateid is delegation */
  	NFS_OPEN_STATE,			/* OPEN stateid is set */
  	NFS_O_RDONLY_STATE,		/* OPEN stateid has read-only state */
  	NFS_O_WRONLY_STATE,		/* OPEN stateid has write-only state */
  	NFS_O_RDWR_STATE,		/* OPEN stateid has read/write state */
  	NFS_STATE_RECLAIM_REBOOT,	/* OPEN stateid server rebooted */
  	NFS_STATE_RECLAIM_NOGRACE,	/* OPEN stateid needs to recover state */
  	NFS_STATE_POSIX_LOCKS,		/* Posix locks are supported */
  	NFS_STATE_RECOVERY_FAILED,	/* OPEN stateid state recovery failed */
  	NFS_STATE_MAY_NOTIFY_LOCK,	/* server may CB_NOTIFY_LOCK */
  	NFS_STATE_CHANGE_WAIT,		/* A state changing operation is outstanding */
  #ifdef CONFIG_NFS_V4_2
  	NFS_CLNT_DST_SSC_COPY_STATE,    /* dst server open state on client*/
  #endif /* CONFIG_NFS_V4_2 */
  };
  
  struct nfs4_state {
  	struct list_head open_states;	/* List of states for the same state_owner */
  	struct list_head inode_states;	/* List of states for the same inode */
  	struct list_head lock_states;	/* List of subservient lock stateids */
  
  	struct nfs4_state_owner *owner;	/* Pointer to the open owner */
  	struct inode *inode;		/* Pointer to the inode */
  
  	unsigned long flags;		/* Do we hold any locks? */
  	spinlock_t state_lock;		/* Protects the lock_states list */
  
  	seqlock_t seqlock;		/* Protects the stateid/open_stateid */
  	nfs4_stateid stateid;		/* Current stateid: may be delegation */
  	nfs4_stateid open_stateid;	/* OPEN stateid */
  
  	/* The following 3 fields are protected by owner->so_lock */
  	unsigned int n_rdonly;		/* Number of read-only references */
  	unsigned int n_wronly;		/* Number of write-only references */
  	unsigned int n_rdwr;		/* Number of read/write references */
  	fmode_t state;			/* State on the server (R,W, or RW) */
  	refcount_t count;
  
  	wait_queue_head_t waitq;
  	struct rcu_head rcu_head;
  };
  
  
  struct nfs4_exception {
  	struct nfs4_state *state;
  	struct inode *inode;
  	nfs4_stateid *stateid;
  	long timeout;
  	unsigned char delay : 1,
  		      recovering : 1,
  		      retry : 1;
  	bool interruptible;
  };
  
  struct nfs4_state_recovery_ops {
  	int owner_flag_bit;
  	int state_flag_bit;
  	int (*recover_open)(struct nfs4_state_owner *, struct nfs4_state *);
  	int (*recover_lock)(struct nfs4_state *, struct file_lock *);
  	int (*establish_clid)(struct nfs_client *, const struct cred *);
  	int (*reclaim_complete)(struct nfs_client *, const struct cred *);
  	int (*detect_trunking)(struct nfs_client *, struct nfs_client **,
  		const struct cred *);
  };
  
  struct nfs4_opendata {
  	struct kref kref;
  	struct nfs_openargs o_arg;
  	struct nfs_openres o_res;
  	struct nfs_open_confirmargs c_arg;
  	struct nfs_open_confirmres c_res;
  	struct nfs4_string owner_name;
  	struct nfs4_string group_name;
  	struct nfs4_label *a_label;
  	struct nfs_fattr f_attr;
  	struct nfs4_label *f_label;
  	struct dentry *dir;
  	struct dentry *dentry;
  	struct nfs4_state_owner *owner;
  	struct nfs4_state *state;
  	struct iattr attrs;
  	struct nfs4_layoutget *lgp;
  	unsigned long timestamp;
  	bool rpc_done;
  	bool file_created;
  	bool is_recover;
  	bool cancelled;
  	int rpc_status;
  };
  
  struct nfs4_add_xprt_data {
  	struct nfs_client	*clp;
  	const struct cred	*cred;
  };
  
  struct nfs4_state_maintenance_ops {
  	int (*sched_state_renewal)(struct nfs_client *, const struct cred *, unsigned);
  	const struct cred * (*get_state_renewal_cred)(struct nfs_client *);
  	int (*renew_lease)(struct nfs_client *, const struct cred *);
  };
  
  struct nfs4_mig_recovery_ops {
  	int (*get_locations)(struct inode *, struct nfs4_fs_locations *,
  		struct page *, const struct cred *);
  	int (*fsid_present)(struct inode *, const struct cred *);
  };
  
  extern const struct dentry_operations nfs4_dentry_operations;
  
  /* dir.c */
  int nfs_atomic_open(struct inode *, struct dentry *, struct file *,
  		    unsigned, umode_t);
  
  /* super.c */
  extern struct file_system_type nfs4_fs_type;
  
  /* nfs4namespace.c */
  struct rpc_clnt *nfs4_negotiate_security(struct rpc_clnt *, struct inode *,
  					 const struct qstr *);
  struct vfsmount *nfs4_submount(struct nfs_server *, struct dentry *,
  			       struct nfs_fh *, struct nfs_fattr *);
  int nfs4_replace_transport(struct nfs_server *server,
  				const struct nfs4_fs_locations *locations);
  
  /* nfs4proc.c */
  extern int nfs4_handle_exception(struct nfs_server *, int, struct nfs4_exception *);
  extern int nfs4_async_handle_error(struct rpc_task *task,
  				   struct nfs_server *server,
  				   struct nfs4_state *state, long *timeout);
  extern int nfs4_call_sync(struct rpc_clnt *, struct nfs_server *,
  			  struct rpc_message *, struct nfs4_sequence_args *,
  			  struct nfs4_sequence_res *, int);
  extern void nfs4_init_sequence(struct nfs4_sequence_args *, struct nfs4_sequence_res *, int, int);
  extern int nfs4_proc_setclientid(struct nfs_client *, u32, unsigned short, const struct cred *, struct nfs4_setclientid_res *);
  extern int nfs4_proc_setclientid_confirm(struct nfs_client *, struct nfs4_setclientid_res *arg, const struct cred *);
  extern int nfs4_proc_get_rootfh(struct nfs_server *, struct nfs_fh *, struct nfs_fsinfo *, bool);
  extern int nfs4_proc_bind_conn_to_session(struct nfs_client *, const struct cred *cred);
  extern int nfs4_proc_exchange_id(struct nfs_client *clp, const struct cred *cred);
  extern int nfs4_destroy_clientid(struct nfs_client *clp);
  extern int nfs4_init_clientid(struct nfs_client *, const struct cred *);
  extern int nfs41_init_clientid(struct nfs_client *, const struct cred *);
  extern int nfs4_do_close(struct nfs4_state *state, gfp_t gfp_mask, int wait);
  extern int nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *fhandle);
  extern int nfs4_proc_fs_locations(struct rpc_clnt *, struct inode *, const struct qstr *,
  				  struct nfs4_fs_locations *, struct page *);
  extern int nfs4_proc_get_locations(struct inode *, struct nfs4_fs_locations *,
  		struct page *page, const struct cred *);
  extern int nfs4_proc_fsid_present(struct inode *, const struct cred *);
  extern struct rpc_clnt *nfs4_proc_lookup_mountpoint(struct inode *, const struct qstr *,
  			    struct nfs_fh *, struct nfs_fattr *);
  extern int nfs4_proc_secinfo(struct inode *, const struct qstr *, struct nfs4_secinfo_flavors *);
  extern const struct xattr_handler *nfs4_xattr_handlers[];
  extern int nfs4_set_rw_stateid(nfs4_stateid *stateid,
  		const struct nfs_open_context *ctx,
  		const struct nfs_lock_context *l_ctx,
  		fmode_t fmode);
  
  extern int nfs4_proc_get_lease_time(struct nfs_client *clp,
  		struct nfs_fsinfo *fsinfo);
  #if defined(CONFIG_NFS_V4_1)
  extern int nfs41_sequence_done(struct rpc_task *, struct nfs4_sequence_res *);
  extern int nfs4_proc_create_session(struct nfs_client *, const struct cred *);
  extern int nfs4_proc_destroy_session(struct nfs4_session *, const struct cred *);
  extern int nfs4_proc_layoutcommit(struct nfs4_layoutcommit_data *data,
  				  bool sync);
  extern int nfs4_detect_session_trunking(struct nfs_client *clp,
  		struct nfs41_exchange_id_res *res, struct rpc_xprt *xprt);
  
  static inline bool
  is_ds_only_client(struct nfs_client *clp)
  {
  	return (clp->cl_exchange_flags & EXCHGID4_FLAG_MASK_PNFS) ==
  		EXCHGID4_FLAG_USE_PNFS_DS;
  }
  
  static inline bool
  is_ds_client(struct nfs_client *clp)
  {
  	return clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_DS;
  }
  
  static inline bool
  _nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_mode,
  		    struct rpc_clnt **clntp, struct rpc_message *msg)
  {
  	rpc_authflavor_t flavor;
  
  	if (sp4_mode == NFS_SP4_MACH_CRED_CLEANUP ||
  	    sp4_mode == NFS_SP4_MACH_CRED_PNFS_CLEANUP) {
  		/* Using machine creds for cleanup operations
  		 * is only relevent if the client credentials
  		 * might expire. So don't bother for
  		 * RPC_AUTH_UNIX.  If file was only exported to
  		 * sec=sys, the PUTFH would fail anyway.
  		 */
  		if ((*clntp)->cl_auth->au_flavor == RPC_AUTH_UNIX)
  			return false;
  	}
  	if (test_bit(sp4_mode, &clp->cl_sp4_flags)) {
  		msg->rpc_cred = rpc_machine_cred();
  
  		flavor = clp->cl_rpcclient->cl_auth->au_flavor;
  		WARN_ON_ONCE(flavor != RPC_AUTH_GSS_KRB5I &&
  			     flavor != RPC_AUTH_GSS_KRB5P);
  		*clntp = clp->cl_rpcclient;
  
  		return true;
  	}
  	return false;
  }
  
  /*
   * Function responsible for determining if an rpc_message should use the
   * machine cred under SP4_MACH_CRED and if so switching the credential and
   * authflavor (using the nfs_client's rpc_clnt which will be krb5i/p).
   * Should be called before rpc_call_sync/rpc_call_async.
   */
  static inline void
  nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_mode,
  		   struct rpc_clnt **clntp, struct rpc_message *msg)
  {
  	_nfs4_state_protect(clp, sp4_mode, clntp, msg);
  }
  
  /*
   * Special wrapper to nfs4_state_protect for write.
   * If WRITE can use machine cred but COMMIT cannot, make sure all writes
   * that use machine cred use NFS_FILE_SYNC.
   */
  static inline void
  nfs4_state_protect_write(struct nfs_client *clp, struct rpc_clnt **clntp,
  			 struct rpc_message *msg, struct nfs_pgio_header *hdr)
  {
  	if (_nfs4_state_protect(clp, NFS_SP4_MACH_CRED_WRITE, clntp, msg) &&
  	    !test_bit(NFS_SP4_MACH_CRED_COMMIT, &clp->cl_sp4_flags))
  		hdr->args.stable = NFS_FILE_SYNC;
  }
  #else /* CONFIG_NFS_v4_1 */
  static inline bool
  is_ds_only_client(struct nfs_client *clp)
  {
  	return false;
  }
  
  static inline bool
  is_ds_client(struct nfs_client *clp)
  {
  	return false;
  }
  
  static inline void
  nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_flags,
  		   struct rpc_clnt **clntp, struct rpc_message *msg)
  {
  }
  
  static inline void
  nfs4_state_protect_write(struct nfs_client *clp, struct rpc_clnt **clntp,
  			 struct rpc_message *msg, struct nfs_pgio_header *hdr)
  {
  }
  #endif /* CONFIG_NFS_V4_1 */
  
  extern const struct nfs4_minor_version_ops *nfs_v4_minor_ops[];
  
  extern const u32 nfs4_fattr_bitmap[3];
  extern const u32 nfs4_statfs_bitmap[3];
  extern const u32 nfs4_pathconf_bitmap[3];
  extern const u32 nfs4_fsinfo_bitmap[3];
  extern const u32 nfs4_fs_locations_bitmap[3];
  
  void nfs40_shutdown_client(struct nfs_client *);
  void nfs41_shutdown_client(struct nfs_client *);
  int nfs40_init_client(struct nfs_client *);
  int nfs41_init_client(struct nfs_client *);
  void nfs4_free_client(struct nfs_client *);
  
  struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *);
  
  /* nfs4renewd.c */
  extern void nfs4_schedule_state_renewal(struct nfs_client *);
  extern void nfs4_renewd_prepare_shutdown(struct nfs_server *);
  extern void nfs4_kill_renewd(struct nfs_client *);
  extern void nfs4_renew_state(struct work_struct *);
  extern void nfs4_set_lease_period(struct nfs_client *clp,
  		unsigned long lease,
  		unsigned long lastrenewed);
  
  
  /* nfs4state.c */
  const struct cred *nfs4_get_clid_cred(struct nfs_client *clp);
  const struct cred *nfs4_get_machine_cred(struct nfs_client *clp);
  const struct cred *nfs4_get_renew_cred(struct nfs_client *clp);
  int nfs4_discover_server_trunking(struct nfs_client *clp,
  			struct nfs_client **);
  int nfs40_discover_server_trunking(struct nfs_client *clp,
  			struct nfs_client **, const struct cred *);
  #if defined(CONFIG_NFS_V4_1)
  int nfs41_discover_server_trunking(struct nfs_client *clp,
  			struct nfs_client **, const struct cred *);
  extern void nfs4_schedule_session_recovery(struct nfs4_session *, int);
  extern void nfs41_notify_server(struct nfs_client *);
  #else
  static inline void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
  {
  }
  #endif /* CONFIG_NFS_V4_1 */
  
  extern struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *, const struct cred *, gfp_t);
  extern void nfs4_put_state_owner(struct nfs4_state_owner *);
  extern void nfs4_purge_state_owners(struct nfs_server *, struct list_head *);
  extern void nfs4_free_state_owners(struct list_head *head);
  extern struct nfs4_state * nfs4_get_open_state(struct inode *, struct nfs4_state_owner *);
  extern void nfs4_put_open_state(struct nfs4_state *);
  extern void nfs4_close_state(struct nfs4_state *, fmode_t);
  extern void nfs4_close_sync(struct nfs4_state *, fmode_t);
  extern void nfs4_state_set_mode_locked(struct nfs4_state *, fmode_t);
  extern void nfs_inode_find_state_and_recover(struct inode *inode,
  		const nfs4_stateid *stateid);
  extern int nfs4_state_mark_reclaim_nograce(struct nfs_client *, struct nfs4_state *);
  extern void nfs4_schedule_lease_recovery(struct nfs_client *);
  extern int nfs4_wait_clnt_recover(struct nfs_client *clp);
  extern int nfs4_client_recover_expired_lease(struct nfs_client *clp);
  extern void nfs4_schedule_state_manager(struct nfs_client *);
  extern void nfs4_schedule_path_down_recovery(struct nfs_client *clp);
  extern int nfs4_schedule_stateid_recovery(const struct nfs_server *, struct nfs4_state *);
  extern int nfs4_schedule_migration_recovery(const struct nfs_server *);
  extern void nfs4_schedule_lease_moved_recovery(struct nfs_client *);
  extern void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags, bool);
  extern void nfs41_handle_server_scope(struct nfs_client *,
  				      struct nfs41_server_scope **);
  extern void nfs4_put_lock_state(struct nfs4_lock_state *lsp);
  extern int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl);
  extern int nfs4_select_rw_stateid(struct nfs4_state *, fmode_t,
  		const struct nfs_lock_context *, nfs4_stateid *,
  		const struct cred **);
  extern bool nfs4_refresh_open_stateid(nfs4_stateid *dst,
  		struct nfs4_state *state);
  extern bool nfs4_copy_open_stateid(nfs4_stateid *dst,
  		struct nfs4_state *state);
  
  extern struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask);
  extern int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task);
  extern void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid);
  extern void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid);
  extern void nfs_release_seqid(struct nfs_seqid *seqid);
  extern void nfs_free_seqid(struct nfs_seqid *seqid);
  extern int nfs4_setup_sequence(struct nfs_client *client,
  				struct nfs4_sequence_args *args,
  				struct nfs4_sequence_res *res,
  				struct rpc_task *task);
  extern int nfs4_sequence_done(struct rpc_task *task,
  			      struct nfs4_sequence_res *res);
  
  extern void nfs4_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp);
  extern int nfs4_proc_commit(struct file *dst, __u64 offset, __u32 count, struct nfs_commitres *res);
  extern const nfs4_stateid zero_stateid;
  extern const nfs4_stateid invalid_stateid;
  
  /* nfs4super.c */
  struct nfs_mount_info;
  extern struct nfs_subversion nfs_v4;
  struct dentry *nfs4_try_mount(int, const char *, struct nfs_mount_info *, struct nfs_subversion *);
  extern bool nfs4_disable_idmapping;
  extern unsigned short max_session_slots;
  extern unsigned short max_session_cb_slots;
  extern unsigned short send_implementation_id;
  extern bool recover_lost_locks;
  
  #define NFS4_CLIENT_ID_UNIQ_LEN		(64)
  extern char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN];
  
  /* nfs4sysctl.c */
  #ifdef CONFIG_SYSCTL
  int nfs4_register_sysctl(void);
  void nfs4_unregister_sysctl(void);
  #else
  static inline int nfs4_register_sysctl(void)
  {
  	return 0;
  }
  
  static inline void nfs4_unregister_sysctl(void)
  {
  }
  #endif
  
  /* nfs4xdr.c */
  extern const struct rpc_procinfo nfs4_procedures[];
  
  struct nfs4_mount_data;
  
  /* callback_xdr.c */
  extern const struct svc_version nfs4_callback_version1;
  extern const struct svc_version nfs4_callback_version4;
  
  static inline void nfs4_stateid_copy(nfs4_stateid *dst, const nfs4_stateid *src)
  {
  	memcpy(dst->data, src->data, sizeof(dst->data));
  	dst->type = src->type;
  }
  
  static inline bool nfs4_stateid_match(const nfs4_stateid *dst, const nfs4_stateid *src)
  {
  	if (dst->type != src->type)
  		return false;
  	return memcmp(dst->data, src->data, sizeof(dst->data)) == 0;
  }
  
  static inline bool nfs4_stateid_match_other(const nfs4_stateid *dst, const nfs4_stateid *src)
  {
  	return memcmp(dst->other, src->other, NFS4_STATEID_OTHER_SIZE) == 0;
  }
  
  static inline bool nfs4_stateid_is_newer(const nfs4_stateid *s1, const nfs4_stateid *s2)
  {
  	return (s32)(be32_to_cpu(s1->seqid) - be32_to_cpu(s2->seqid)) > 0;
  }
  
  static inline bool nfs4_valid_open_stateid(const struct nfs4_state *state)
  {
  	return test_bit(NFS_STATE_RECOVERY_FAILED, &state->flags) == 0;
  }
  
  static inline bool nfs4_state_match_open_stateid_other(const struct nfs4_state *state,
  		const nfs4_stateid *stateid)
  {
  	return test_bit(NFS_OPEN_STATE, &state->flags) &&
  		nfs4_stateid_match_other(&state->open_stateid, stateid);
  }
  
  #else
  
  #define nfs4_close_state(a, b) do { } while (0)
  #define nfs4_close_sync(a, b) do { } while (0)
  #define nfs4_state_protect(a, b, c, d) do { } while (0)
  #define nfs4_state_protect_write(a, b, c, d) do { } while (0)
  
  #endif /* CONFIG_NFS_V4 */
  #endif /* __LINUX_FS_NFS_NFS4_FS.H */
  