xref: /linux/fs/nfs/nfs4_fs.h (revision 9a379e77033f02c4a071891afdf0f0a01eff8ccb)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * linux/fs/nfs/nfs4_fs.h
4  *
5  * Copyright (C) 2005 Trond Myklebust
6  *
7  * NFSv4-specific filesystem definitions and declarations
8  */
9 
10 #ifndef __LINUX_FS_NFS_NFS4_FS_H
11 #define __LINUX_FS_NFS_NFS4_FS_H
12 
13 #if defined(CONFIG_NFS_V4_2)
14 #define NFS4_MAX_MINOR_VERSION 2
15 #elif defined(CONFIG_NFS_V4_1)
16 #define NFS4_MAX_MINOR_VERSION 1
17 #else
18 #define NFS4_MAX_MINOR_VERSION 0
19 #endif
20 
21 #if IS_ENABLED(CONFIG_NFS_V4)
22 
23 #define NFS4_MAX_LOOP_ON_RECOVER (10)
24 
25 #include <linux/seqlock.h>
26 
27 struct idmap;
28 
29 enum nfs4_client_state {
30 	NFS4CLNT_MANAGER_RUNNING  = 0,
31 	NFS4CLNT_CHECK_LEASE,
32 	NFS4CLNT_LEASE_EXPIRED,
33 	NFS4CLNT_RECLAIM_REBOOT,
34 	NFS4CLNT_RECLAIM_NOGRACE,
35 	NFS4CLNT_DELEGRETURN,
36 	NFS4CLNT_SESSION_RESET,
37 	NFS4CLNT_LEASE_CONFIRM,
38 	NFS4CLNT_SERVER_SCOPE_MISMATCH,
39 	NFS4CLNT_PURGE_STATE,
40 	NFS4CLNT_BIND_CONN_TO_SESSION,
41 	NFS4CLNT_MOVED,
42 	NFS4CLNT_LEASE_MOVED,
43 	NFS4CLNT_DELEGATION_EXPIRED,
44 };
45 
46 #define NFS4_RENEW_TIMEOUT		0x01
47 #define NFS4_RENEW_DELEGATION_CB	0x02
48 
49 struct nfs_seqid_counter;
50 struct nfs4_minor_version_ops {
51 	u32	minor_version;
52 	unsigned init_caps;
53 
54 	int	(*init_client)(struct nfs_client *);
55 	void	(*shutdown_client)(struct nfs_client *);
56 	bool	(*match_stateid)(const nfs4_stateid *,
57 			const nfs4_stateid *);
58 	int	(*find_root_sec)(struct nfs_server *, struct nfs_fh *,
59 			struct nfs_fsinfo *);
60 	void	(*free_lock_state)(struct nfs_server *,
61 			struct nfs4_lock_state *);
62 	int	(*test_and_free_expired)(struct nfs_server *,
63 			nfs4_stateid *, struct rpc_cred *);
64 	struct nfs_seqid *
65 		(*alloc_seqid)(struct nfs_seqid_counter *, gfp_t);
66 	int	(*session_trunk)(struct rpc_clnt *, struct rpc_xprt *, void *);
67 	const struct rpc_call_ops *call_sync_ops;
68 	const struct nfs4_state_recovery_ops *reboot_recovery_ops;
69 	const struct nfs4_state_recovery_ops *nograce_recovery_ops;
70 	const struct nfs4_state_maintenance_ops *state_renewal_ops;
71 	const struct nfs4_mig_recovery_ops *mig_recovery_ops;
72 };
73 
74 #define NFS_SEQID_CONFIRMED 1
75 struct nfs_seqid_counter {
76 	ktime_t create_time;
77 	int owner_id;
78 	int flags;
79 	u32 counter;
80 	spinlock_t lock;		/* Protects the list */
81 	struct list_head list;		/* Defines sequence of RPC calls */
82 	struct rpc_wait_queue	wait;	/* RPC call delay queue */
83 };
84 
85 struct nfs_seqid {
86 	struct nfs_seqid_counter *sequence;
87 	struct list_head list;
88 	struct rpc_task *task;
89 };
90 
91 static inline void nfs_confirm_seqid(struct nfs_seqid_counter *seqid, int status)
92 {
93 	if (seqid_mutating_err(-status))
94 		seqid->flags |= NFS_SEQID_CONFIRMED;
95 }
96 
97 /*
98  * NFS4 state_owners and lock_owners are simply labels for ordered
99  * sequences of RPC calls. Their sole purpose is to provide once-only
100  * semantics by allowing the server to identify replayed requests.
101  */
102 struct nfs4_state_owner {
103 	struct nfs_server    *so_server;
104 	struct list_head     so_lru;
105 	unsigned long        so_expires;
106 	struct rb_node	     so_server_node;
107 
108 	struct rpc_cred	     *so_cred;	 /* Associated cred */
109 
110 	spinlock_t	     so_lock;
111 	atomic_t	     so_count;
112 	unsigned long	     so_flags;
113 	struct list_head     so_states;
114 	struct nfs_seqid_counter so_seqid;
115 	seqcount_t	     so_reclaim_seqcount;
116 	struct mutex	     so_delegreturn_mutex;
117 };
118 
119 enum {
120 	NFS_OWNER_RECLAIM_REBOOT,
121 	NFS_OWNER_RECLAIM_NOGRACE
122 };
123 
124 #define NFS_LOCK_NEW		0
125 #define NFS_LOCK_RECLAIM	1
126 #define NFS_LOCK_EXPIRED	2
127 
128 /*
129  * struct nfs4_state maintains the client-side state for a given
130  * (state_owner,inode) tuple (OPEN) or state_owner (LOCK).
131  *
132  * OPEN:
133  * In order to know when to OPEN_DOWNGRADE or CLOSE the state on the server,
134  * we need to know how many files are open for reading or writing on a
135  * given inode. This information too is stored here.
136  *
137  * LOCK: one nfs4_state (LOCK) to hold the lock stateid nfs4_state(OPEN)
138  */
139 
140 struct nfs4_lock_state {
141 	struct list_head	ls_locks;	/* Other lock stateids */
142 	struct nfs4_state *	ls_state;	/* Pointer to open state */
143 #define NFS_LOCK_INITIALIZED 0
144 #define NFS_LOCK_LOST        1
145 	unsigned long		ls_flags;
146 	struct nfs_seqid_counter	ls_seqid;
147 	nfs4_stateid		ls_stateid;
148 	refcount_t		ls_count;
149 	fl_owner_t		ls_owner;
150 };
151 
152 /* bits for nfs4_state->flags */
153 enum {
154 	LK_STATE_IN_USE,
155 	NFS_DELEGATED_STATE,		/* Current stateid is delegation */
156 	NFS_OPEN_STATE,			/* OPEN stateid is set */
157 	NFS_O_RDONLY_STATE,		/* OPEN stateid has read-only state */
158 	NFS_O_WRONLY_STATE,		/* OPEN stateid has write-only state */
159 	NFS_O_RDWR_STATE,		/* OPEN stateid has read/write state */
160 	NFS_STATE_RECLAIM_REBOOT,	/* OPEN stateid server rebooted */
161 	NFS_STATE_RECLAIM_NOGRACE,	/* OPEN stateid needs to recover state */
162 	NFS_STATE_POSIX_LOCKS,		/* Posix locks are supported */
163 	NFS_STATE_RECOVERY_FAILED,	/* OPEN stateid state recovery failed */
164 	NFS_STATE_MAY_NOTIFY_LOCK,	/* server may CB_NOTIFY_LOCK */
165 	NFS_STATE_CHANGE_WAIT,		/* A state changing operation is outstanding */
166 };
167 
168 struct nfs4_state {
169 	struct list_head open_states;	/* List of states for the same state_owner */
170 	struct list_head inode_states;	/* List of states for the same inode */
171 	struct list_head lock_states;	/* List of subservient lock stateids */
172 
173 	struct nfs4_state_owner *owner;	/* Pointer to the open owner */
174 	struct inode *inode;		/* Pointer to the inode */
175 
176 	unsigned long flags;		/* Do we hold any locks? */
177 	spinlock_t state_lock;		/* Protects the lock_states list */
178 
179 	seqlock_t seqlock;		/* Protects the stateid/open_stateid */
180 	nfs4_stateid stateid;		/* Current stateid: may be delegation */
181 	nfs4_stateid open_stateid;	/* OPEN stateid */
182 
183 	/* The following 3 fields are protected by owner->so_lock */
184 	unsigned int n_rdonly;		/* Number of read-only references */
185 	unsigned int n_wronly;		/* Number of write-only references */
186 	unsigned int n_rdwr;		/* Number of read/write references */
187 	fmode_t state;			/* State on the server (R,W, or RW) */
188 	atomic_t count;
189 
190 	wait_queue_head_t waitq;
191 };
192 
193 
194 struct nfs4_exception {
195 	struct nfs4_state *state;
196 	struct inode *inode;
197 	nfs4_stateid *stateid;
198 	long timeout;
199 	unsigned char delay : 1,
200 		      recovering : 1,
201 		      retry : 1;
202 };
203 
204 struct nfs4_state_recovery_ops {
205 	int owner_flag_bit;
206 	int state_flag_bit;
207 	int (*recover_open)(struct nfs4_state_owner *, struct nfs4_state *);
208 	int (*recover_lock)(struct nfs4_state *, struct file_lock *);
209 	int (*establish_clid)(struct nfs_client *, struct rpc_cred *);
210 	int (*reclaim_complete)(struct nfs_client *, struct rpc_cred *);
211 	int (*detect_trunking)(struct nfs_client *, struct nfs_client **,
212 		struct rpc_cred *);
213 };
214 
215 struct nfs4_add_xprt_data {
216 	struct nfs_client	*clp;
217 	struct rpc_cred		*cred;
218 };
219 
220 struct nfs4_state_maintenance_ops {
221 	int (*sched_state_renewal)(struct nfs_client *, struct rpc_cred *, unsigned);
222 	struct rpc_cred * (*get_state_renewal_cred_locked)(struct nfs_client *);
223 	int (*renew_lease)(struct nfs_client *, struct rpc_cred *);
224 };
225 
226 struct nfs4_mig_recovery_ops {
227 	int (*get_locations)(struct inode *, struct nfs4_fs_locations *,
228 		struct page *, struct rpc_cred *);
229 	int (*fsid_present)(struct inode *, struct rpc_cred *);
230 };
231 
232 extern const struct dentry_operations nfs4_dentry_operations;
233 
234 /* dir.c */
235 int nfs_atomic_open(struct inode *, struct dentry *, struct file *,
236 		    unsigned, umode_t, int *);
237 
238 /* super.c */
239 extern struct file_system_type nfs4_fs_type;
240 
241 /* nfs4namespace.c */
242 struct rpc_clnt *nfs4_negotiate_security(struct rpc_clnt *, struct inode *,
243 					 const struct qstr *);
244 struct vfsmount *nfs4_submount(struct nfs_server *, struct dentry *,
245 			       struct nfs_fh *, struct nfs_fattr *);
246 int nfs4_replace_transport(struct nfs_server *server,
247 				const struct nfs4_fs_locations *locations);
248 
249 /* nfs4proc.c */
250 extern int nfs4_handle_exception(struct nfs_server *, int, struct nfs4_exception *);
251 extern int nfs4_call_sync(struct rpc_clnt *, struct nfs_server *,
252 			  struct rpc_message *, struct nfs4_sequence_args *,
253 			  struct nfs4_sequence_res *, int);
254 extern void nfs4_init_sequence(struct nfs4_sequence_args *, struct nfs4_sequence_res *, int);
255 extern int nfs4_proc_setclientid(struct nfs_client *, u32, unsigned short, struct rpc_cred *, struct nfs4_setclientid_res *);
256 extern int nfs4_proc_setclientid_confirm(struct nfs_client *, struct nfs4_setclientid_res *arg, struct rpc_cred *);
257 extern int nfs4_proc_get_rootfh(struct nfs_server *, struct nfs_fh *, struct nfs_fsinfo *, bool);
258 extern int nfs4_proc_bind_conn_to_session(struct nfs_client *, struct rpc_cred *cred);
259 extern int nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred);
260 extern int nfs4_destroy_clientid(struct nfs_client *clp);
261 extern int nfs4_init_clientid(struct nfs_client *, struct rpc_cred *);
262 extern int nfs41_init_clientid(struct nfs_client *, struct rpc_cred *);
263 extern int nfs4_do_close(struct nfs4_state *state, gfp_t gfp_mask, int wait);
264 extern int nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *fhandle);
265 extern int nfs4_proc_fs_locations(struct rpc_clnt *, struct inode *, const struct qstr *,
266 				  struct nfs4_fs_locations *, struct page *);
267 extern int nfs4_proc_get_locations(struct inode *, struct nfs4_fs_locations *,
268 		struct page *page, struct rpc_cred *);
269 extern int nfs4_proc_fsid_present(struct inode *, struct rpc_cred *);
270 extern struct rpc_clnt *nfs4_proc_lookup_mountpoint(struct inode *, const struct qstr *,
271 			    struct nfs_fh *, struct nfs_fattr *);
272 extern int nfs4_proc_secinfo(struct inode *, const struct qstr *, struct nfs4_secinfo_flavors *);
273 extern const struct xattr_handler *nfs4_xattr_handlers[];
274 extern int nfs4_set_rw_stateid(nfs4_stateid *stateid,
275 		const struct nfs_open_context *ctx,
276 		const struct nfs_lock_context *l_ctx,
277 		fmode_t fmode);
278 
279 #if defined(CONFIG_NFS_V4_1)
280 extern int nfs41_sequence_done(struct rpc_task *, struct nfs4_sequence_res *);
281 extern int nfs4_proc_create_session(struct nfs_client *, struct rpc_cred *);
282 extern int nfs4_proc_destroy_session(struct nfs4_session *, struct rpc_cred *);
283 extern int nfs4_proc_get_lease_time(struct nfs_client *clp,
284 		struct nfs_fsinfo *fsinfo);
285 extern int nfs4_proc_layoutcommit(struct nfs4_layoutcommit_data *data,
286 				  bool sync);
287 extern int nfs4_detect_session_trunking(struct nfs_client *clp,
288 		struct nfs41_exchange_id_res *res, struct rpc_xprt *xprt);
289 
290 static inline bool
291 is_ds_only_client(struct nfs_client *clp)
292 {
293 	return (clp->cl_exchange_flags & EXCHGID4_FLAG_MASK_PNFS) ==
294 		EXCHGID4_FLAG_USE_PNFS_DS;
295 }
296 
297 static inline bool
298 is_ds_client(struct nfs_client *clp)
299 {
300 	return clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_DS;
301 }
302 
303 static inline bool
304 _nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_mode,
305 		    struct rpc_clnt **clntp, struct rpc_message *msg)
306 {
307 	struct rpc_cred *newcred = NULL;
308 	rpc_authflavor_t flavor;
309 
310 	if (sp4_mode == NFS_SP4_MACH_CRED_CLEANUP ||
311 	    sp4_mode == NFS_SP4_MACH_CRED_PNFS_CLEANUP) {
312 		/* Using machine creds for cleanup operations
313 		 * is only relevent if the client credentials
314 		 * might expire. So don't bother for
315 		 * RPC_AUTH_UNIX.  If file was only exported to
316 		 * sec=sys, the PUTFH would fail anyway.
317 		 */
318 		if ((*clntp)->cl_auth->au_flavor == RPC_AUTH_UNIX)
319 			return false;
320 	}
321 	if (test_bit(sp4_mode, &clp->cl_sp4_flags)) {
322 		spin_lock(&clp->cl_lock);
323 		if (clp->cl_machine_cred != NULL)
324 			/* don't call get_rpccred on the machine cred -
325 			 * a reference will be held for life of clp */
326 			newcred = clp->cl_machine_cred;
327 		spin_unlock(&clp->cl_lock);
328 		msg->rpc_cred = newcred;
329 
330 		flavor = clp->cl_rpcclient->cl_auth->au_flavor;
331 		WARN_ON_ONCE(flavor != RPC_AUTH_GSS_KRB5I &&
332 			     flavor != RPC_AUTH_GSS_KRB5P);
333 		*clntp = clp->cl_rpcclient;
334 
335 		return true;
336 	}
337 	return false;
338 }
339 
340 /*
341  * Function responsible for determining if an rpc_message should use the
342  * machine cred under SP4_MACH_CRED and if so switching the credential and
343  * authflavor (using the nfs_client's rpc_clnt which will be krb5i/p).
344  * Should be called before rpc_call_sync/rpc_call_async.
345  */
346 static inline void
347 nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_mode,
348 		   struct rpc_clnt **clntp, struct rpc_message *msg)
349 {
350 	_nfs4_state_protect(clp, sp4_mode, clntp, msg);
351 }
352 
353 /*
354  * Special wrapper to nfs4_state_protect for write.
355  * If WRITE can use machine cred but COMMIT cannot, make sure all writes
356  * that use machine cred use NFS_FILE_SYNC.
357  */
358 static inline void
359 nfs4_state_protect_write(struct nfs_client *clp, struct rpc_clnt **clntp,
360 			 struct rpc_message *msg, struct nfs_pgio_header *hdr)
361 {
362 	if (_nfs4_state_protect(clp, NFS_SP4_MACH_CRED_WRITE, clntp, msg) &&
363 	    !test_bit(NFS_SP4_MACH_CRED_COMMIT, &clp->cl_sp4_flags))
364 		hdr->args.stable = NFS_FILE_SYNC;
365 }
366 #else /* CONFIG_NFS_v4_1 */
367 static inline bool
368 is_ds_only_client(struct nfs_client *clp)
369 {
370 	return false;
371 }
372 
373 static inline bool
374 is_ds_client(struct nfs_client *clp)
375 {
376 	return false;
377 }
378 
379 static inline void
380 nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_flags,
381 		   struct rpc_clnt **clntp, struct rpc_message *msg)
382 {
383 }
384 
385 static inline void
386 nfs4_state_protect_write(struct nfs_client *clp, struct rpc_clnt **clntp,
387 			 struct rpc_message *msg, struct nfs_pgio_header *hdr)
388 {
389 }
390 #endif /* CONFIG_NFS_V4_1 */
391 
392 extern const struct nfs4_minor_version_ops *nfs_v4_minor_ops[];
393 
394 extern const u32 nfs4_fattr_bitmap[3];
395 extern const u32 nfs4_statfs_bitmap[3];
396 extern const u32 nfs4_pathconf_bitmap[3];
397 extern const u32 nfs4_fsinfo_bitmap[3];
398 extern const u32 nfs4_fs_locations_bitmap[3];
399 
400 void nfs40_shutdown_client(struct nfs_client *);
401 void nfs41_shutdown_client(struct nfs_client *);
402 int nfs40_init_client(struct nfs_client *);
403 int nfs41_init_client(struct nfs_client *);
404 void nfs4_free_client(struct nfs_client *);
405 
406 struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *);
407 
408 /* nfs4renewd.c */
409 extern void nfs4_schedule_state_renewal(struct nfs_client *);
410 extern void nfs4_renewd_prepare_shutdown(struct nfs_server *);
411 extern void nfs4_kill_renewd(struct nfs_client *);
412 extern void nfs4_renew_state(struct work_struct *);
413 extern void nfs4_set_lease_period(struct nfs_client *clp,
414 		unsigned long lease,
415 		unsigned long lastrenewed);
416 
417 
418 /* nfs4state.c */
419 struct rpc_cred *nfs4_get_clid_cred(struct nfs_client *clp);
420 struct rpc_cred *nfs4_get_machine_cred_locked(struct nfs_client *clp);
421 struct rpc_cred *nfs4_get_renew_cred_locked(struct nfs_client *clp);
422 int nfs4_discover_server_trunking(struct nfs_client *clp,
423 			struct nfs_client **);
424 int nfs40_discover_server_trunking(struct nfs_client *clp,
425 			struct nfs_client **, struct rpc_cred *);
426 #if defined(CONFIG_NFS_V4_1)
427 int nfs41_discover_server_trunking(struct nfs_client *clp,
428 			struct nfs_client **, struct rpc_cred *);
429 extern void nfs4_schedule_session_recovery(struct nfs4_session *, int);
430 extern void nfs41_notify_server(struct nfs_client *);
431 #else
432 static inline void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
433 {
434 }
435 #endif /* CONFIG_NFS_V4_1 */
436 
437 extern struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *, struct rpc_cred *, gfp_t);
438 extern void nfs4_put_state_owner(struct nfs4_state_owner *);
439 extern void nfs4_purge_state_owners(struct nfs_server *);
440 extern struct nfs4_state * nfs4_get_open_state(struct inode *, struct nfs4_state_owner *);
441 extern void nfs4_put_open_state(struct nfs4_state *);
442 extern void nfs4_close_state(struct nfs4_state *, fmode_t);
443 extern void nfs4_close_sync(struct nfs4_state *, fmode_t);
444 extern void nfs4_state_set_mode_locked(struct nfs4_state *, fmode_t);
445 extern void nfs_inode_find_state_and_recover(struct inode *inode,
446 		const nfs4_stateid *stateid);
447 extern int nfs4_state_mark_reclaim_nograce(struct nfs_client *, struct nfs4_state *);
448 extern void nfs4_schedule_lease_recovery(struct nfs_client *);
449 extern int nfs4_wait_clnt_recover(struct nfs_client *clp);
450 extern int nfs4_client_recover_expired_lease(struct nfs_client *clp);
451 extern void nfs4_schedule_state_manager(struct nfs_client *);
452 extern void nfs4_schedule_path_down_recovery(struct nfs_client *clp);
453 extern int nfs4_schedule_stateid_recovery(const struct nfs_server *, struct nfs4_state *);
454 extern int nfs4_schedule_migration_recovery(const struct nfs_server *);
455 extern void nfs4_schedule_lease_moved_recovery(struct nfs_client *);
456 extern void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags, bool);
457 extern void nfs41_handle_server_scope(struct nfs_client *,
458 				      struct nfs41_server_scope **);
459 extern void nfs4_put_lock_state(struct nfs4_lock_state *lsp);
460 extern int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl);
461 extern int nfs4_select_rw_stateid(struct nfs4_state *, fmode_t,
462 		const struct nfs_lock_context *, nfs4_stateid *,
463 		struct rpc_cred **);
464 extern bool nfs4_refresh_open_stateid(nfs4_stateid *dst,
465 		struct nfs4_state *state);
466 extern bool nfs4_copy_open_stateid(nfs4_stateid *dst,
467 		struct nfs4_state *state);
468 
469 extern struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask);
470 extern int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task);
471 extern void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid);
472 extern void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid);
473 extern void nfs_release_seqid(struct nfs_seqid *seqid);
474 extern void nfs_free_seqid(struct nfs_seqid *seqid);
475 extern int nfs4_setup_sequence(struct nfs_client *client,
476 				struct nfs4_sequence_args *args,
477 				struct nfs4_sequence_res *res,
478 				struct rpc_task *task);
479 extern int nfs4_sequence_done(struct rpc_task *task,
480 			      struct nfs4_sequence_res *res);
481 
482 extern void nfs4_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp);
483 
484 extern const nfs4_stateid zero_stateid;
485 extern const nfs4_stateid invalid_stateid;
486 
487 /* nfs4super.c */
488 struct nfs_mount_info;
489 extern struct nfs_subversion nfs_v4;
490 struct dentry *nfs4_try_mount(int, const char *, struct nfs_mount_info *, struct nfs_subversion *);
491 extern bool nfs4_disable_idmapping;
492 extern unsigned short max_session_slots;
493 extern unsigned short max_session_cb_slots;
494 extern unsigned short send_implementation_id;
495 extern bool recover_lost_locks;
496 
497 #define NFS4_CLIENT_ID_UNIQ_LEN		(64)
498 extern char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN];
499 
500 /* nfs4sysctl.c */
501 #ifdef CONFIG_SYSCTL
502 int nfs4_register_sysctl(void);
503 void nfs4_unregister_sysctl(void);
504 #else
505 static inline int nfs4_register_sysctl(void)
506 {
507 	return 0;
508 }
509 
510 static inline void nfs4_unregister_sysctl(void)
511 {
512 }
513 #endif
514 
515 /* nfs4xdr.c */
516 extern const struct rpc_procinfo nfs4_procedures[];
517 
518 struct nfs4_mount_data;
519 
520 /* callback_xdr.c */
521 extern const struct svc_version nfs4_callback_version1;
522 extern const struct svc_version nfs4_callback_version4;
523 
524 static inline void nfs4_stateid_copy(nfs4_stateid *dst, const nfs4_stateid *src)
525 {
526 	memcpy(dst->data, src->data, sizeof(dst->data));
527 	dst->type = src->type;
528 }
529 
530 static inline bool nfs4_stateid_match(const nfs4_stateid *dst, const nfs4_stateid *src)
531 {
532 	if (dst->type != src->type)
533 		return false;
534 	return memcmp(dst->data, src->data, sizeof(dst->data)) == 0;
535 }
536 
537 static inline bool nfs4_stateid_match_other(const nfs4_stateid *dst, const nfs4_stateid *src)
538 {
539 	return memcmp(dst->other, src->other, NFS4_STATEID_OTHER_SIZE) == 0;
540 }
541 
542 static inline bool nfs4_stateid_is_newer(const nfs4_stateid *s1, const nfs4_stateid *s2)
543 {
544 	return (s32)(be32_to_cpu(s1->seqid) - be32_to_cpu(s2->seqid)) > 0;
545 }
546 
547 static inline bool nfs4_valid_open_stateid(const struct nfs4_state *state)
548 {
549 	return test_bit(NFS_STATE_RECOVERY_FAILED, &state->flags) == 0;
550 }
551 
552 static inline bool nfs4_state_match_open_stateid_other(const struct nfs4_state *state,
553 		const nfs4_stateid *stateid)
554 {
555 	return test_bit(NFS_OPEN_STATE, &state->flags) &&
556 		nfs4_stateid_match_other(&state->open_stateid, stateid);
557 }
558 
559 #else
560 
561 #define nfs4_close_state(a, b) do { } while (0)
562 #define nfs4_close_sync(a, b) do { } while (0)
563 #define nfs4_state_protect(a, b, c, d) do { } while (0)
564 #define nfs4_state_protect_write(a, b, c, d) do { } while (0)
565 
566 #endif /* CONFIG_NFS_V4 */
567 #endif /* __LINUX_FS_NFS_NFS4_FS.H */
568