xref: /openbmc/linux/fs/nfs/nfs4_fs.h (revision 32981ea5)
1 /*
2  * linux/fs/nfs/nfs4_fs.h
3  *
4  * Copyright (C) 2005 Trond Myklebust
5  *
6  * NFSv4-specific filesystem definitions and declarations
7  */
8 
9 #ifndef __LINUX_FS_NFS_NFS4_FS_H
10 #define __LINUX_FS_NFS_NFS4_FS_H
11 
12 #if defined(CONFIG_NFS_V4_2)
13 #define NFS4_MAX_MINOR_VERSION 2
14 #elif defined(CONFIG_NFS_V4_1)
15 #define NFS4_MAX_MINOR_VERSION 1
16 #else
17 #define NFS4_MAX_MINOR_VERSION 0
18 #endif
19 
20 #if IS_ENABLED(CONFIG_NFS_V4)
21 
22 #define NFS4_MAX_LOOP_ON_RECOVER (10)
23 
24 #include <linux/seqlock.h>
25 
26 struct idmap;
27 
28 enum nfs4_client_state {
29 	NFS4CLNT_MANAGER_RUNNING  = 0,
30 	NFS4CLNT_CHECK_LEASE,
31 	NFS4CLNT_LEASE_EXPIRED,
32 	NFS4CLNT_RECLAIM_REBOOT,
33 	NFS4CLNT_RECLAIM_NOGRACE,
34 	NFS4CLNT_DELEGRETURN,
35 	NFS4CLNT_SESSION_RESET,
36 	NFS4CLNT_LEASE_CONFIRM,
37 	NFS4CLNT_SERVER_SCOPE_MISMATCH,
38 	NFS4CLNT_PURGE_STATE,
39 	NFS4CLNT_BIND_CONN_TO_SESSION,
40 	NFS4CLNT_MOVED,
41 	NFS4CLNT_LEASE_MOVED,
42 };
43 
44 #define NFS4_RENEW_TIMEOUT		0x01
45 #define NFS4_RENEW_DELEGATION_CB	0x02
46 
47 struct nfs_seqid_counter;
48 struct nfs4_minor_version_ops {
49 	u32	minor_version;
50 	unsigned init_caps;
51 
52 	int	(*init_client)(struct nfs_client *);
53 	void	(*shutdown_client)(struct nfs_client *);
54 	bool	(*match_stateid)(const nfs4_stateid *,
55 			const nfs4_stateid *);
56 	int	(*find_root_sec)(struct nfs_server *, struct nfs_fh *,
57 			struct nfs_fsinfo *);
58 	void	(*free_lock_state)(struct nfs_server *,
59 			struct nfs4_lock_state *);
60 	struct nfs_seqid *
61 		(*alloc_seqid)(struct nfs_seqid_counter *, gfp_t);
62 	const struct rpc_call_ops *call_sync_ops;
63 	const struct nfs4_state_recovery_ops *reboot_recovery_ops;
64 	const struct nfs4_state_recovery_ops *nograce_recovery_ops;
65 	const struct nfs4_state_maintenance_ops *state_renewal_ops;
66 	const struct nfs4_mig_recovery_ops *mig_recovery_ops;
67 };
68 
69 #define NFS_SEQID_CONFIRMED 1
70 struct nfs_seqid_counter {
71 	ktime_t create_time;
72 	int owner_id;
73 	int flags;
74 	u32 counter;
75 	spinlock_t lock;		/* Protects the list */
76 	struct list_head list;		/* Defines sequence of RPC calls */
77 	struct rpc_wait_queue	wait;	/* RPC call delay queue */
78 };
79 
80 struct nfs_seqid {
81 	struct nfs_seqid_counter *sequence;
82 	struct list_head list;
83 	struct rpc_task *task;
84 };
85 
86 static inline void nfs_confirm_seqid(struct nfs_seqid_counter *seqid, int status)
87 {
88 	if (seqid_mutating_err(-status))
89 		seqid->flags |= NFS_SEQID_CONFIRMED;
90 }
91 
92 /*
93  * NFS4 state_owners and lock_owners are simply labels for ordered
94  * sequences of RPC calls. Their sole purpose is to provide once-only
95  * semantics by allowing the server to identify replayed requests.
96  */
97 struct nfs4_state_owner {
98 	struct nfs_server    *so_server;
99 	struct list_head     so_lru;
100 	unsigned long        so_expires;
101 	struct rb_node	     so_server_node;
102 
103 	struct rpc_cred	     *so_cred;	 /* Associated cred */
104 
105 	spinlock_t	     so_lock;
106 	atomic_t	     so_count;
107 	unsigned long	     so_flags;
108 	struct list_head     so_states;
109 	struct nfs_seqid_counter so_seqid;
110 	seqcount_t	     so_reclaim_seqcount;
111 	struct mutex	     so_delegreturn_mutex;
112 };
113 
114 enum {
115 	NFS_OWNER_RECLAIM_REBOOT,
116 	NFS_OWNER_RECLAIM_NOGRACE
117 };
118 
119 #define NFS_LOCK_NEW		0
120 #define NFS_LOCK_RECLAIM	1
121 #define NFS_LOCK_EXPIRED	2
122 
123 /*
124  * struct nfs4_state maintains the client-side state for a given
125  * (state_owner,inode) tuple (OPEN) or state_owner (LOCK).
126  *
127  * OPEN:
128  * In order to know when to OPEN_DOWNGRADE or CLOSE the state on the server,
129  * we need to know how many files are open for reading or writing on a
130  * given inode. This information too is stored here.
131  *
132  * LOCK: one nfs4_state (LOCK) to hold the lock stateid nfs4_state(OPEN)
133  */
134 
135 struct nfs4_lock_state {
136 	struct list_head	ls_locks;	/* Other lock stateids */
137 	struct nfs4_state *	ls_state;	/* Pointer to open state */
138 #define NFS_LOCK_INITIALIZED 0
139 #define NFS_LOCK_LOST        1
140 	unsigned long		ls_flags;
141 	struct nfs_seqid_counter	ls_seqid;
142 	nfs4_stateid		ls_stateid;
143 	atomic_t		ls_count;
144 	fl_owner_t		ls_owner;
145 };
146 
147 /* bits for nfs4_state->flags */
148 enum {
149 	LK_STATE_IN_USE,
150 	NFS_DELEGATED_STATE,		/* Current stateid is delegation */
151 	NFS_OPEN_STATE,			/* OPEN stateid is set */
152 	NFS_O_RDONLY_STATE,		/* OPEN stateid has read-only state */
153 	NFS_O_WRONLY_STATE,		/* OPEN stateid has write-only state */
154 	NFS_O_RDWR_STATE,		/* OPEN stateid has read/write state */
155 	NFS_STATE_RECLAIM_REBOOT,	/* OPEN stateid server rebooted */
156 	NFS_STATE_RECLAIM_NOGRACE,	/* OPEN stateid needs to recover state */
157 	NFS_STATE_POSIX_LOCKS,		/* Posix locks are supported */
158 	NFS_STATE_RECOVERY_FAILED,	/* OPEN stateid state recovery failed */
159 };
160 
161 struct nfs4_state {
162 	struct list_head open_states;	/* List of states for the same state_owner */
163 	struct list_head inode_states;	/* List of states for the same inode */
164 	struct list_head lock_states;	/* List of subservient lock stateids */
165 
166 	struct nfs4_state_owner *owner;	/* Pointer to the open owner */
167 	struct inode *inode;		/* Pointer to the inode */
168 
169 	unsigned long flags;		/* Do we hold any locks? */
170 	spinlock_t state_lock;		/* Protects the lock_states list */
171 
172 	seqlock_t seqlock;		/* Protects the stateid/open_stateid */
173 	nfs4_stateid stateid;		/* Current stateid: may be delegation */
174 	nfs4_stateid open_stateid;	/* OPEN stateid */
175 
176 	/* The following 3 fields are protected by owner->so_lock */
177 	unsigned int n_rdonly;		/* Number of read-only references */
178 	unsigned int n_wronly;		/* Number of write-only references */
179 	unsigned int n_rdwr;		/* Number of read/write references */
180 	fmode_t state;			/* State on the server (R,W, or RW) */
181 	atomic_t count;
182 };
183 
184 
185 struct nfs4_exception {
186 	struct nfs4_state *state;
187 	struct inode *inode;
188 	long timeout;
189 	unsigned char delay : 1,
190 		      recovering : 1,
191 		      retry : 1;
192 };
193 
194 struct nfs4_state_recovery_ops {
195 	int owner_flag_bit;
196 	int state_flag_bit;
197 	int (*recover_open)(struct nfs4_state_owner *, struct nfs4_state *);
198 	int (*recover_lock)(struct nfs4_state *, struct file_lock *);
199 	int (*establish_clid)(struct nfs_client *, struct rpc_cred *);
200 	int (*reclaim_complete)(struct nfs_client *, struct rpc_cred *);
201 	int (*detect_trunking)(struct nfs_client *, struct nfs_client **,
202 		struct rpc_cred *);
203 };
204 
205 struct nfs4_state_maintenance_ops {
206 	int (*sched_state_renewal)(struct nfs_client *, struct rpc_cred *, unsigned);
207 	struct rpc_cred * (*get_state_renewal_cred_locked)(struct nfs_client *);
208 	int (*renew_lease)(struct nfs_client *, struct rpc_cred *);
209 };
210 
211 struct nfs4_mig_recovery_ops {
212 	int (*get_locations)(struct inode *, struct nfs4_fs_locations *,
213 		struct page *, struct rpc_cred *);
214 	int (*fsid_present)(struct inode *, struct rpc_cred *);
215 };
216 
217 extern const struct dentry_operations nfs4_dentry_operations;
218 
219 /* dir.c */
220 int nfs_atomic_open(struct inode *, struct dentry *, struct file *,
221 		    unsigned, umode_t, int *);
222 
223 /* super.c */
224 extern struct file_system_type nfs4_fs_type;
225 
226 /* nfs4namespace.c */
227 struct rpc_clnt *nfs4_negotiate_security(struct rpc_clnt *, struct inode *, struct qstr *);
228 struct vfsmount *nfs4_submount(struct nfs_server *, struct dentry *,
229 			       struct nfs_fh *, struct nfs_fattr *);
230 int nfs4_replace_transport(struct nfs_server *server,
231 				const struct nfs4_fs_locations *locations);
232 
233 /* nfs4proc.c */
234 extern int nfs4_handle_exception(struct nfs_server *, int, struct nfs4_exception *);
235 extern int nfs4_call_sync(struct rpc_clnt *, struct nfs_server *,
236 			  struct rpc_message *, struct nfs4_sequence_args *,
237 			  struct nfs4_sequence_res *, int);
238 extern void nfs4_init_sequence(struct nfs4_sequence_args *, struct nfs4_sequence_res *, int);
239 extern int nfs4_proc_setclientid(struct nfs_client *, u32, unsigned short, struct rpc_cred *, struct nfs4_setclientid_res *);
240 extern int nfs4_proc_setclientid_confirm(struct nfs_client *, struct nfs4_setclientid_res *arg, struct rpc_cred *);
241 extern int nfs4_proc_get_rootfh(struct nfs_server *, struct nfs_fh *, struct nfs_fsinfo *, bool);
242 extern int nfs4_proc_bind_conn_to_session(struct nfs_client *, struct rpc_cred *cred);
243 extern int nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred);
244 extern int nfs4_destroy_clientid(struct nfs_client *clp);
245 extern int nfs4_init_clientid(struct nfs_client *, struct rpc_cred *);
246 extern int nfs41_init_clientid(struct nfs_client *, struct rpc_cred *);
247 extern int nfs4_do_close(struct nfs4_state *state, gfp_t gfp_mask, int wait);
248 extern int nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *fhandle);
249 extern int nfs4_proc_fs_locations(struct rpc_clnt *, struct inode *, const struct qstr *,
250 				  struct nfs4_fs_locations *, struct page *);
251 extern int nfs4_proc_get_locations(struct inode *, struct nfs4_fs_locations *,
252 		struct page *page, struct rpc_cred *);
253 extern int nfs4_proc_fsid_present(struct inode *, struct rpc_cred *);
254 extern struct rpc_clnt *nfs4_proc_lookup_mountpoint(struct inode *, struct qstr *,
255 			    struct nfs_fh *, struct nfs_fattr *);
256 extern int nfs4_proc_secinfo(struct inode *, const struct qstr *, struct nfs4_secinfo_flavors *);
257 extern const struct xattr_handler *nfs4_xattr_handlers[];
258 extern int nfs4_set_rw_stateid(nfs4_stateid *stateid,
259 		const struct nfs_open_context *ctx,
260 		const struct nfs_lock_context *l_ctx,
261 		fmode_t fmode);
262 
263 #if defined(CONFIG_NFS_V4_1)
264 static inline struct nfs4_session *nfs4_get_session(const struct nfs_server *server)
265 {
266 	return server->nfs_client->cl_session;
267 }
268 
269 extern int nfs41_setup_sequence(struct nfs4_session *session,
270 		struct nfs4_sequence_args *args, struct nfs4_sequence_res *res,
271 		struct rpc_task *task);
272 extern int nfs41_sequence_done(struct rpc_task *, struct nfs4_sequence_res *);
273 extern int nfs4_proc_create_session(struct nfs_client *, struct rpc_cred *);
274 extern int nfs4_proc_destroy_session(struct nfs4_session *, struct rpc_cred *);
275 extern int nfs4_proc_get_lease_time(struct nfs_client *clp,
276 		struct nfs_fsinfo *fsinfo);
277 extern int nfs4_proc_layoutcommit(struct nfs4_layoutcommit_data *data,
278 				  bool sync);
279 
280 static inline bool
281 is_ds_only_client(struct nfs_client *clp)
282 {
283 	return (clp->cl_exchange_flags & EXCHGID4_FLAG_MASK_PNFS) ==
284 		EXCHGID4_FLAG_USE_PNFS_DS;
285 }
286 
287 static inline bool
288 is_ds_client(struct nfs_client *clp)
289 {
290 	return clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_DS;
291 }
292 
293 static inline bool
294 _nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_mode,
295 		    struct rpc_clnt **clntp, struct rpc_message *msg)
296 {
297 	struct rpc_cred *newcred = NULL;
298 	rpc_authflavor_t flavor;
299 
300 	if (test_bit(sp4_mode, &clp->cl_sp4_flags)) {
301 		spin_lock(&clp->cl_lock);
302 		if (clp->cl_machine_cred != NULL)
303 			/* don't call get_rpccred on the machine cred -
304 			 * a reference will be held for life of clp */
305 			newcred = clp->cl_machine_cred;
306 		spin_unlock(&clp->cl_lock);
307 		msg->rpc_cred = newcred;
308 
309 		flavor = clp->cl_rpcclient->cl_auth->au_flavor;
310 		WARN_ON_ONCE(flavor != RPC_AUTH_GSS_KRB5I &&
311 			     flavor != RPC_AUTH_GSS_KRB5P);
312 		*clntp = clp->cl_rpcclient;
313 
314 		return true;
315 	}
316 	return false;
317 }
318 
319 /*
320  * Function responsible for determining if an rpc_message should use the
321  * machine cred under SP4_MACH_CRED and if so switching the credential and
322  * authflavor (using the nfs_client's rpc_clnt which will be krb5i/p).
323  * Should be called before rpc_call_sync/rpc_call_async.
324  */
325 static inline void
326 nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_mode,
327 		   struct rpc_clnt **clntp, struct rpc_message *msg)
328 {
329 	_nfs4_state_protect(clp, sp4_mode, clntp, msg);
330 }
331 
332 /*
333  * Special wrapper to nfs4_state_protect for write.
334  * If WRITE can use machine cred but COMMIT cannot, make sure all writes
335  * that use machine cred use NFS_FILE_SYNC.
336  */
337 static inline void
338 nfs4_state_protect_write(struct nfs_client *clp, struct rpc_clnt **clntp,
339 			 struct rpc_message *msg, struct nfs_pgio_header *hdr)
340 {
341 	if (_nfs4_state_protect(clp, NFS_SP4_MACH_CRED_WRITE, clntp, msg) &&
342 	    !test_bit(NFS_SP4_MACH_CRED_COMMIT, &clp->cl_sp4_flags))
343 		hdr->args.stable = NFS_FILE_SYNC;
344 }
345 #else /* CONFIG_NFS_v4_1 */
346 static inline struct nfs4_session *nfs4_get_session(const struct nfs_server *server)
347 {
348 	return NULL;
349 }
350 
351 static inline bool
352 is_ds_only_client(struct nfs_client *clp)
353 {
354 	return false;
355 }
356 
357 static inline bool
358 is_ds_client(struct nfs_client *clp)
359 {
360 	return false;
361 }
362 
363 static inline void
364 nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_flags,
365 		   struct rpc_clnt **clntp, struct rpc_message *msg)
366 {
367 }
368 
369 static inline void
370 nfs4_state_protect_write(struct nfs_client *clp, struct rpc_clnt **clntp,
371 			 struct rpc_message *msg, struct nfs_pgio_header *hdr)
372 {
373 }
374 #endif /* CONFIG_NFS_V4_1 */
375 
376 extern const struct nfs4_minor_version_ops *nfs_v4_minor_ops[];
377 
378 extern const u32 nfs4_fattr_bitmap[3];
379 extern const u32 nfs4_statfs_bitmap[3];
380 extern const u32 nfs4_pathconf_bitmap[3];
381 extern const u32 nfs4_fsinfo_bitmap[3];
382 extern const u32 nfs4_fs_locations_bitmap[3];
383 
384 void nfs40_shutdown_client(struct nfs_client *);
385 void nfs41_shutdown_client(struct nfs_client *);
386 int nfs40_init_client(struct nfs_client *);
387 int nfs41_init_client(struct nfs_client *);
388 void nfs4_free_client(struct nfs_client *);
389 
390 struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *);
391 
392 /* nfs4renewd.c */
393 extern void nfs4_schedule_state_renewal(struct nfs_client *);
394 extern void nfs4_renewd_prepare_shutdown(struct nfs_server *);
395 extern void nfs4_kill_renewd(struct nfs_client *);
396 extern void nfs4_renew_state(struct work_struct *);
397 
398 /* nfs4state.c */
399 struct rpc_cred *nfs4_get_clid_cred(struct nfs_client *clp);
400 struct rpc_cred *nfs4_get_machine_cred_locked(struct nfs_client *clp);
401 struct rpc_cred *nfs4_get_renew_cred_locked(struct nfs_client *clp);
402 int nfs4_discover_server_trunking(struct nfs_client *clp,
403 			struct nfs_client **);
404 int nfs40_discover_server_trunking(struct nfs_client *clp,
405 			struct nfs_client **, struct rpc_cred *);
406 #if defined(CONFIG_NFS_V4_1)
407 int nfs41_discover_server_trunking(struct nfs_client *clp,
408 			struct nfs_client **, struct rpc_cred *);
409 extern void nfs4_schedule_session_recovery(struct nfs4_session *, int);
410 extern void nfs41_notify_server(struct nfs_client *);
411 #else
412 static inline void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
413 {
414 }
415 #endif /* CONFIG_NFS_V4_1 */
416 
417 extern struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *, struct rpc_cred *, gfp_t);
418 extern void nfs4_put_state_owner(struct nfs4_state_owner *);
419 extern void nfs4_purge_state_owners(struct nfs_server *);
420 extern struct nfs4_state * nfs4_get_open_state(struct inode *, struct nfs4_state_owner *);
421 extern void nfs4_put_open_state(struct nfs4_state *);
422 extern void nfs4_close_state(struct nfs4_state *, fmode_t);
423 extern void nfs4_close_sync(struct nfs4_state *, fmode_t);
424 extern void nfs4_state_set_mode_locked(struct nfs4_state *, fmode_t);
425 extern void nfs_inode_find_state_and_recover(struct inode *inode,
426 		const nfs4_stateid *stateid);
427 extern int nfs4_state_mark_reclaim_nograce(struct nfs_client *, struct nfs4_state *);
428 extern void nfs4_schedule_lease_recovery(struct nfs_client *);
429 extern int nfs4_wait_clnt_recover(struct nfs_client *clp);
430 extern int nfs4_client_recover_expired_lease(struct nfs_client *clp);
431 extern void nfs4_schedule_state_manager(struct nfs_client *);
432 extern void nfs4_schedule_path_down_recovery(struct nfs_client *clp);
433 extern int nfs4_schedule_stateid_recovery(const struct nfs_server *, struct nfs4_state *);
434 extern int nfs4_schedule_migration_recovery(const struct nfs_server *);
435 extern void nfs4_schedule_lease_moved_recovery(struct nfs_client *);
436 extern void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags);
437 extern void nfs41_handle_server_scope(struct nfs_client *,
438 				      struct nfs41_server_scope **);
439 extern void nfs4_put_lock_state(struct nfs4_lock_state *lsp);
440 extern int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl);
441 extern int nfs4_select_rw_stateid(struct nfs4_state *, fmode_t,
442 		const struct nfs_lockowner *, nfs4_stateid *,
443 		struct rpc_cred **);
444 
445 extern struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask);
446 extern int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task);
447 extern void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid);
448 extern void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid);
449 extern void nfs_release_seqid(struct nfs_seqid *seqid);
450 extern void nfs_free_seqid(struct nfs_seqid *seqid);
451 extern int nfs40_setup_sequence(struct nfs4_slot_table *tbl,
452 				struct nfs4_sequence_args *args,
453 				struct nfs4_sequence_res *res,
454 				struct rpc_task *task);
455 extern int nfs4_sequence_done(struct rpc_task *task,
456 			      struct nfs4_sequence_res *res);
457 
458 extern void nfs4_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp);
459 
460 extern const nfs4_stateid zero_stateid;
461 
462 /* nfs4super.c */
463 struct nfs_mount_info;
464 extern struct nfs_subversion nfs_v4;
465 struct dentry *nfs4_try_mount(int, const char *, struct nfs_mount_info *, struct nfs_subversion *);
466 extern bool nfs4_disable_idmapping;
467 extern unsigned short max_session_slots;
468 extern unsigned short send_implementation_id;
469 extern bool recover_lost_locks;
470 
471 #define NFS4_CLIENT_ID_UNIQ_LEN		(64)
472 extern char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN];
473 
474 /* nfs4sysctl.c */
475 #ifdef CONFIG_SYSCTL
476 int nfs4_register_sysctl(void);
477 void nfs4_unregister_sysctl(void);
478 #else
479 static inline int nfs4_register_sysctl(void)
480 {
481 	return 0;
482 }
483 
484 static inline void nfs4_unregister_sysctl(void)
485 {
486 }
487 #endif
488 
489 /* nfs4xdr.c */
490 extern struct rpc_procinfo nfs4_procedures[];
491 
492 struct nfs4_mount_data;
493 
494 /* callback_xdr.c */
495 extern struct svc_version nfs4_callback_version1;
496 extern struct svc_version nfs4_callback_version4;
497 
498 static inline void nfs4_stateid_copy(nfs4_stateid *dst, const nfs4_stateid *src)
499 {
500 	memcpy(dst->data, src->data, sizeof(dst->data));
501 	dst->type = src->type;
502 }
503 
504 static inline bool nfs4_stateid_match(const nfs4_stateid *dst, const nfs4_stateid *src)
505 {
506 	if (dst->type != src->type)
507 		return false;
508 	return memcmp(dst->data, src->data, sizeof(dst->data)) == 0;
509 }
510 
511 static inline bool nfs4_stateid_match_other(const nfs4_stateid *dst, const nfs4_stateid *src)
512 {
513 	return memcmp(dst->other, src->other, NFS4_STATEID_OTHER_SIZE) == 0;
514 }
515 
516 static inline bool nfs4_stateid_is_newer(const nfs4_stateid *s1, const nfs4_stateid *s2)
517 {
518 	return (s32)(be32_to_cpu(s1->seqid) - be32_to_cpu(s2->seqid)) > 0;
519 }
520 
521 static inline bool nfs4_valid_open_stateid(const struct nfs4_state *state)
522 {
523 	return test_bit(NFS_STATE_RECOVERY_FAILED, &state->flags) == 0;
524 }
525 
526 #else
527 
528 #define nfs4_close_state(a, b) do { } while (0)
529 #define nfs4_close_sync(a, b) do { } while (0)
530 #define nfs4_state_protect(a, b, c, d) do { } while (0)
531 #define nfs4_state_protect_write(a, b, c, d) do { } while (0)
532 
533 #endif /* CONFIG_NFS_V4 */
534 #endif /* __LINUX_FS_NFS_NFS4_FS.H */
535