xref: /openbmc/linux/fs/nfs/nfs4_fs.h (revision 1c2f87c2)
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 nfs4_minor_version_ops {
48 	u32	minor_version;
49 	unsigned init_caps;
50 
51 	int	(*init_client)(struct nfs_client *);
52 	void	(*shutdown_client)(struct nfs_client *);
53 	bool	(*match_stateid)(const nfs4_stateid *,
54 			const nfs4_stateid *);
55 	int	(*find_root_sec)(struct nfs_server *, struct nfs_fh *,
56 			struct nfs_fsinfo *);
57 	int	(*free_lock_state)(struct nfs_server *,
58 			struct nfs4_lock_state *);
59 	const struct rpc_call_ops *call_sync_ops;
60 	const struct nfs4_state_recovery_ops *reboot_recovery_ops;
61 	const struct nfs4_state_recovery_ops *nograce_recovery_ops;
62 	const struct nfs4_state_maintenance_ops *state_renewal_ops;
63 	const struct nfs4_mig_recovery_ops *mig_recovery_ops;
64 };
65 
66 #define NFS_SEQID_CONFIRMED 1
67 struct nfs_seqid_counter {
68 	ktime_t create_time;
69 	int owner_id;
70 	int flags;
71 	u32 counter;
72 	spinlock_t lock;		/* Protects the list */
73 	struct list_head list;		/* Defines sequence of RPC calls */
74 	struct rpc_wait_queue	wait;	/* RPC call delay queue */
75 };
76 
77 struct nfs_seqid {
78 	struct nfs_seqid_counter *sequence;
79 	struct list_head list;
80 	struct rpc_task *task;
81 };
82 
83 static inline void nfs_confirm_seqid(struct nfs_seqid_counter *seqid, int status)
84 {
85 	if (seqid_mutating_err(-status))
86 		seqid->flags |= NFS_SEQID_CONFIRMED;
87 }
88 
89 /*
90  * NFS4 state_owners and lock_owners are simply labels for ordered
91  * sequences of RPC calls. Their sole purpose is to provide once-only
92  * semantics by allowing the server to identify replayed requests.
93  */
94 struct nfs4_state_owner {
95 	struct nfs_server    *so_server;
96 	struct list_head     so_lru;
97 	unsigned long        so_expires;
98 	struct rb_node	     so_server_node;
99 
100 	struct rpc_cred	     *so_cred;	 /* Associated cred */
101 
102 	spinlock_t	     so_lock;
103 	atomic_t	     so_count;
104 	unsigned long	     so_flags;
105 	struct list_head     so_states;
106 	struct nfs_seqid_counter so_seqid;
107 	seqcount_t	     so_reclaim_seqcount;
108 	struct mutex	     so_delegreturn_mutex;
109 };
110 
111 enum {
112 	NFS_OWNER_RECLAIM_REBOOT,
113 	NFS_OWNER_RECLAIM_NOGRACE
114 };
115 
116 #define NFS_LOCK_NEW		0
117 #define NFS_LOCK_RECLAIM	1
118 #define NFS_LOCK_EXPIRED	2
119 
120 /*
121  * struct nfs4_state maintains the client-side state for a given
122  * (state_owner,inode) tuple (OPEN) or state_owner (LOCK).
123  *
124  * OPEN:
125  * In order to know when to OPEN_DOWNGRADE or CLOSE the state on the server,
126  * we need to know how many files are open for reading or writing on a
127  * given inode. This information too is stored here.
128  *
129  * LOCK: one nfs4_state (LOCK) to hold the lock stateid nfs4_state(OPEN)
130  */
131 
132 struct nfs4_lock_owner {
133 	unsigned int lo_type;
134 #define NFS4_ANY_LOCK_TYPE	(0U)
135 #define NFS4_FLOCK_LOCK_TYPE	(1U << 0)
136 #define NFS4_POSIX_LOCK_TYPE	(1U << 1)
137 	union {
138 		fl_owner_t posix_owner;
139 		pid_t flock_owner;
140 	} lo_u;
141 };
142 
143 struct nfs4_lock_state {
144 	struct list_head	ls_locks;	/* Other lock stateids */
145 	struct nfs4_state *	ls_state;	/* Pointer to open state */
146 #define NFS_LOCK_INITIALIZED 0
147 #define NFS_LOCK_LOST        1
148 	unsigned long		ls_flags;
149 	struct nfs_seqid_counter	ls_seqid;
150 	nfs4_stateid		ls_stateid;
151 	atomic_t		ls_count;
152 	struct nfs4_lock_owner	ls_owner;
153 };
154 
155 /* bits for nfs4_state->flags */
156 enum {
157 	LK_STATE_IN_USE,
158 	NFS_DELEGATED_STATE,		/* Current stateid is delegation */
159 	NFS_OPEN_STATE,			/* OPEN stateid is set */
160 	NFS_O_RDONLY_STATE,		/* OPEN stateid has read-only state */
161 	NFS_O_WRONLY_STATE,		/* OPEN stateid has write-only state */
162 	NFS_O_RDWR_STATE,		/* OPEN stateid has read/write state */
163 	NFS_STATE_RECLAIM_REBOOT,	/* OPEN stateid server rebooted */
164 	NFS_STATE_RECLAIM_NOGRACE,	/* OPEN stateid needs to recover state */
165 	NFS_STATE_POSIX_LOCKS,		/* Posix locks are supported */
166 	NFS_STATE_RECOVERY_FAILED,	/* OPEN stateid state recovery failed */
167 };
168 
169 struct nfs4_state {
170 	struct list_head open_states;	/* List of states for the same state_owner */
171 	struct list_head inode_states;	/* List of states for the same inode */
172 	struct list_head lock_states;	/* List of subservient lock stateids */
173 
174 	struct nfs4_state_owner *owner;	/* Pointer to the open owner */
175 	struct inode *inode;		/* Pointer to the inode */
176 
177 	unsigned long flags;		/* Do we hold any locks? */
178 	spinlock_t state_lock;		/* Protects the lock_states list */
179 
180 	seqlock_t seqlock;		/* Protects the stateid/open_stateid */
181 	nfs4_stateid stateid;		/* Current stateid: may be delegation */
182 	nfs4_stateid open_stateid;	/* OPEN stateid */
183 
184 	/* The following 3 fields are protected by owner->so_lock */
185 	unsigned int n_rdonly;		/* Number of read-only references */
186 	unsigned int n_wronly;		/* Number of write-only references */
187 	unsigned int n_rdwr;		/* Number of read/write references */
188 	fmode_t state;			/* State on the server (R,W, or RW) */
189 	atomic_t count;
190 };
191 
192 
193 struct nfs4_exception {
194 	long timeout;
195 	int retry;
196 	struct nfs4_state *state;
197 	struct inode *inode;
198 };
199 
200 struct nfs4_state_recovery_ops {
201 	int owner_flag_bit;
202 	int state_flag_bit;
203 	int (*recover_open)(struct nfs4_state_owner *, struct nfs4_state *);
204 	int (*recover_lock)(struct nfs4_state *, struct file_lock *);
205 	int (*establish_clid)(struct nfs_client *, struct rpc_cred *);
206 	int (*reclaim_complete)(struct nfs_client *, struct rpc_cred *);
207 	int (*detect_trunking)(struct nfs_client *, struct nfs_client **,
208 		struct rpc_cred *);
209 };
210 
211 struct nfs4_state_maintenance_ops {
212 	int (*sched_state_renewal)(struct nfs_client *, struct rpc_cred *, unsigned);
213 	struct rpc_cred * (*get_state_renewal_cred_locked)(struct nfs_client *);
214 	int (*renew_lease)(struct nfs_client *, struct rpc_cred *);
215 };
216 
217 struct nfs4_mig_recovery_ops {
218 	int (*get_locations)(struct inode *, struct nfs4_fs_locations *,
219 		struct page *, struct rpc_cred *);
220 	int (*fsid_present)(struct inode *, struct rpc_cred *);
221 };
222 
223 extern const struct dentry_operations nfs4_dentry_operations;
224 
225 /* dir.c */
226 int nfs_atomic_open(struct inode *, struct dentry *, struct file *,
227 		    unsigned, umode_t, int *);
228 
229 /* super.c */
230 extern struct file_system_type nfs4_fs_type;
231 
232 /* nfs4namespace.c */
233 struct rpc_clnt *nfs4_create_sec_client(struct rpc_clnt *, struct inode *, struct qstr *);
234 struct vfsmount *nfs4_submount(struct nfs_server *, struct dentry *,
235 			       struct nfs_fh *, struct nfs_fattr *);
236 int nfs4_replace_transport(struct nfs_server *server,
237 				const struct nfs4_fs_locations *locations);
238 
239 /* nfs4proc.c */
240 extern int nfs4_proc_setclientid(struct nfs_client *, u32, unsigned short, struct rpc_cred *, struct nfs4_setclientid_res *);
241 extern int nfs4_proc_setclientid_confirm(struct nfs_client *, struct nfs4_setclientid_res *arg, struct rpc_cred *);
242 extern int nfs4_proc_get_rootfh(struct nfs_server *, struct nfs_fh *, struct nfs_fsinfo *, bool);
243 extern int nfs4_proc_bind_conn_to_session(struct nfs_client *, struct rpc_cred *cred);
244 extern int nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred);
245 extern int nfs4_destroy_clientid(struct nfs_client *clp);
246 extern int nfs4_init_clientid(struct nfs_client *, struct rpc_cred *);
247 extern int nfs41_init_clientid(struct nfs_client *, struct rpc_cred *);
248 extern int nfs4_do_close(struct nfs4_state *state, gfp_t gfp_mask, int wait);
249 extern int nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *fhandle);
250 extern int nfs4_proc_fs_locations(struct rpc_clnt *, struct inode *, const struct qstr *,
251 				  struct nfs4_fs_locations *, struct page *);
252 extern int nfs4_proc_get_locations(struct inode *, struct nfs4_fs_locations *,
253 		struct page *page, struct rpc_cred *);
254 extern int nfs4_proc_fsid_present(struct inode *, struct rpc_cred *);
255 extern struct rpc_clnt *nfs4_proc_lookup_mountpoint(struct inode *, struct qstr *,
256 			    struct nfs_fh *, struct nfs_fattr *);
257 extern int nfs4_proc_secinfo(struct inode *, const struct qstr *, struct nfs4_secinfo_flavors *);
258 extern const struct xattr_handler *nfs4_xattr_handlers[];
259 extern int nfs4_set_rw_stateid(nfs4_stateid *stateid,
260 		const struct nfs_open_context *ctx,
261 		const struct nfs_lock_context *l_ctx,
262 		fmode_t fmode);
263 
264 #if defined(CONFIG_NFS_V4_1)
265 static inline struct nfs4_session *nfs4_get_session(const struct nfs_server *server)
266 {
267 	return server->nfs_client->cl_session;
268 }
269 
270 extern int nfs41_setup_sequence(struct nfs4_session *session,
271 		struct nfs4_sequence_args *args, struct nfs4_sequence_res *res,
272 		struct rpc_task *task);
273 extern int nfs41_sequence_done(struct rpc_task *, struct nfs4_sequence_res *);
274 extern int nfs4_proc_create_session(struct nfs_client *, struct rpc_cred *);
275 extern int nfs4_proc_destroy_session(struct nfs4_session *, struct rpc_cred *);
276 extern int nfs4_proc_get_lease_time(struct nfs_client *clp,
277 		struct nfs_fsinfo *fsinfo);
278 extern int nfs4_proc_layoutcommit(struct nfs4_layoutcommit_data *data,
279 				  bool sync);
280 
281 static inline bool
282 is_ds_only_client(struct nfs_client *clp)
283 {
284 	return (clp->cl_exchange_flags & EXCHGID4_FLAG_MASK_PNFS) ==
285 		EXCHGID4_FLAG_USE_PNFS_DS;
286 }
287 
288 static inline bool
289 is_ds_client(struct nfs_client *clp)
290 {
291 	return clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_DS;
292 }
293 
294 static inline bool
295 _nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_mode,
296 		    struct rpc_clnt **clntp, struct rpc_message *msg)
297 {
298 	struct rpc_cred *newcred = NULL;
299 	rpc_authflavor_t flavor;
300 
301 	if (test_bit(sp4_mode, &clp->cl_sp4_flags)) {
302 		spin_lock(&clp->cl_lock);
303 		if (clp->cl_machine_cred != NULL)
304 			/* don't call get_rpccred on the machine cred -
305 			 * a reference will be held for life of clp */
306 			newcred = clp->cl_machine_cred;
307 		spin_unlock(&clp->cl_lock);
308 		msg->rpc_cred = newcred;
309 
310 		flavor = clp->cl_rpcclient->cl_auth->au_flavor;
311 		WARN_ON_ONCE(flavor != RPC_AUTH_GSS_KRB5I &&
312 			     flavor != RPC_AUTH_GSS_KRB5P);
313 		*clntp = clp->cl_rpcclient;
314 
315 		return true;
316 	}
317 	return false;
318 }
319 
320 /*
321  * Function responsible for determining if an rpc_message should use the
322  * machine cred under SP4_MACH_CRED and if so switching the credential and
323  * authflavor (using the nfs_client's rpc_clnt which will be krb5i/p).
324  * Should be called before rpc_call_sync/rpc_call_async.
325  */
326 static inline void
327 nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_mode,
328 		   struct rpc_clnt **clntp, struct rpc_message *msg)
329 {
330 	_nfs4_state_protect(clp, sp4_mode, clntp, msg);
331 }
332 
333 /*
334  * Special wrapper to nfs4_state_protect for write.
335  * If WRITE can use machine cred but COMMIT cannot, make sure all writes
336  * that use machine cred use NFS_FILE_SYNC.
337  */
338 static inline void
339 nfs4_state_protect_write(struct nfs_client *clp, struct rpc_clnt **clntp,
340 			 struct rpc_message *msg, struct nfs_write_data *wdata)
341 {
342 	if (_nfs4_state_protect(clp, NFS_SP4_MACH_CRED_WRITE, clntp, msg) &&
343 	    !test_bit(NFS_SP4_MACH_CRED_COMMIT, &clp->cl_sp4_flags))
344 		wdata->args.stable = NFS_FILE_SYNC;
345 }
346 #else /* CONFIG_NFS_v4_1 */
347 static inline struct nfs4_session *nfs4_get_session(const struct nfs_server *server)
348 {
349 	return NULL;
350 }
351 
352 static inline bool
353 is_ds_only_client(struct nfs_client *clp)
354 {
355 	return false;
356 }
357 
358 static inline bool
359 is_ds_client(struct nfs_client *clp)
360 {
361 	return false;
362 }
363 
364 static inline void
365 nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_flags,
366 		   struct rpc_clnt **clntp, struct rpc_message *msg)
367 {
368 }
369 
370 static inline void
371 nfs4_state_protect_write(struct nfs_client *clp, struct rpc_clnt **clntp,
372 			 struct rpc_message *msg, struct nfs_write_data *wdata)
373 {
374 }
375 #endif /* CONFIG_NFS_V4_1 */
376 
377 extern const struct nfs4_minor_version_ops *nfs_v4_minor_ops[];
378 
379 extern const u32 nfs4_fattr_bitmap[3];
380 extern const u32 nfs4_statfs_bitmap[3];
381 extern const u32 nfs4_pathconf_bitmap[3];
382 extern const u32 nfs4_fsinfo_bitmap[3];
383 extern const u32 nfs4_fs_locations_bitmap[3];
384 
385 void nfs40_shutdown_client(struct nfs_client *);
386 void nfs41_shutdown_client(struct nfs_client *);
387 int nfs40_init_client(struct nfs_client *);
388 int nfs41_init_client(struct nfs_client *);
389 void nfs4_free_client(struct nfs_client *);
390 
391 struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *);
392 
393 /* nfs4renewd.c */
394 extern void nfs4_schedule_state_renewal(struct nfs_client *);
395 extern void nfs4_renewd_prepare_shutdown(struct nfs_server *);
396 extern void nfs4_kill_renewd(struct nfs_client *);
397 extern void nfs4_renew_state(struct work_struct *);
398 
399 /* nfs4state.c */
400 struct rpc_cred *nfs4_get_clid_cred(struct nfs_client *clp);
401 struct rpc_cred *nfs4_get_machine_cred_locked(struct nfs_client *clp);
402 struct rpc_cred *nfs4_get_renew_cred_locked(struct nfs_client *clp);
403 int nfs4_discover_server_trunking(struct nfs_client *clp,
404 			struct nfs_client **);
405 int nfs40_discover_server_trunking(struct nfs_client *clp,
406 			struct nfs_client **, struct rpc_cred *);
407 #if defined(CONFIG_NFS_V4_1)
408 int nfs41_discover_server_trunking(struct nfs_client *clp,
409 			struct nfs_client **, struct rpc_cred *);
410 extern void nfs4_schedule_session_recovery(struct nfs4_session *, int);
411 extern void nfs41_server_notify_target_slotid_update(struct nfs_client *clp);
412 extern void nfs41_server_notify_highest_slotid_update(struct nfs_client *clp);
413 
414 #else
415 static inline void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
416 {
417 }
418 #endif /* CONFIG_NFS_V4_1 */
419 
420 extern struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *, struct rpc_cred *, gfp_t);
421 extern void nfs4_put_state_owner(struct nfs4_state_owner *);
422 extern void nfs4_purge_state_owners(struct nfs_server *);
423 extern struct nfs4_state * nfs4_get_open_state(struct inode *, struct nfs4_state_owner *);
424 extern void nfs4_put_open_state(struct nfs4_state *);
425 extern void nfs4_close_state(struct nfs4_state *, fmode_t);
426 extern void nfs4_close_sync(struct nfs4_state *, fmode_t);
427 extern void nfs4_state_set_mode_locked(struct nfs4_state *, fmode_t);
428 extern void nfs_inode_find_state_and_recover(struct inode *inode,
429 		const nfs4_stateid *stateid);
430 extern int nfs4_state_mark_reclaim_nograce(struct nfs_client *, struct nfs4_state *);
431 extern void nfs4_schedule_lease_recovery(struct nfs_client *);
432 extern int nfs4_wait_clnt_recover(struct nfs_client *clp);
433 extern int nfs4_client_recover_expired_lease(struct nfs_client *clp);
434 extern void nfs4_schedule_state_manager(struct nfs_client *);
435 extern void nfs4_schedule_path_down_recovery(struct nfs_client *clp);
436 extern int nfs4_schedule_stateid_recovery(const struct nfs_server *, struct nfs4_state *);
437 extern int nfs4_schedule_migration_recovery(const struct nfs_server *);
438 extern void nfs4_schedule_lease_moved_recovery(struct nfs_client *);
439 extern void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags);
440 extern void nfs41_handle_server_scope(struct nfs_client *,
441 				      struct nfs41_server_scope **);
442 extern void nfs4_put_lock_state(struct nfs4_lock_state *lsp);
443 extern int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl);
444 extern int nfs4_select_rw_stateid(nfs4_stateid *, struct nfs4_state *,
445 		fmode_t, const struct nfs_lockowner *);
446 
447 extern struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask);
448 extern int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task);
449 extern void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid);
450 extern void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid);
451 extern void nfs_release_seqid(struct nfs_seqid *seqid);
452 extern void nfs_free_seqid(struct nfs_seqid *seqid);
453 
454 extern void nfs4_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp);
455 
456 extern const nfs4_stateid zero_stateid;
457 
458 /* nfs4super.c */
459 struct nfs_mount_info;
460 extern struct nfs_subversion nfs_v4;
461 struct dentry *nfs4_try_mount(int, const char *, struct nfs_mount_info *, struct nfs_subversion *);
462 extern bool nfs4_disable_idmapping;
463 extern unsigned short max_session_slots;
464 extern unsigned short send_implementation_id;
465 extern bool recover_lost_locks;
466 
467 #define NFS4_CLIENT_ID_UNIQ_LEN		(64)
468 extern char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN];
469 
470 /* nfs4sysctl.c */
471 #ifdef CONFIG_SYSCTL
472 int nfs4_register_sysctl(void);
473 void nfs4_unregister_sysctl(void);
474 #else
475 static inline int nfs4_register_sysctl(void)
476 {
477 	return 0;
478 }
479 
480 static inline void nfs4_unregister_sysctl(void)
481 {
482 }
483 #endif
484 
485 /* nfs4xdr.c */
486 extern struct rpc_procinfo nfs4_procedures[];
487 
488 struct nfs4_mount_data;
489 
490 /* callback_xdr.c */
491 extern struct svc_version nfs4_callback_version1;
492 extern struct svc_version nfs4_callback_version4;
493 
494 static inline void nfs4_stateid_copy(nfs4_stateid *dst, const nfs4_stateid *src)
495 {
496 	memcpy(dst, src, sizeof(*dst));
497 }
498 
499 static inline bool nfs4_stateid_match(const nfs4_stateid *dst, const nfs4_stateid *src)
500 {
501 	return memcmp(dst, src, sizeof(*dst)) == 0;
502 }
503 
504 static inline bool nfs4_stateid_match_other(const nfs4_stateid *dst, const nfs4_stateid *src)
505 {
506 	return memcmp(dst->other, src->other, NFS4_STATEID_OTHER_SIZE) == 0;
507 }
508 
509 static inline bool nfs4_stateid_is_newer(const nfs4_stateid *s1, const nfs4_stateid *s2)
510 {
511 	return (s32)(be32_to_cpu(s1->seqid) - be32_to_cpu(s2->seqid)) > 0;
512 }
513 
514 static inline bool nfs4_valid_open_stateid(const struct nfs4_state *state)
515 {
516 	return test_bit(NFS_STATE_RECOVERY_FAILED, &state->flags) == 0;
517 }
518 
519 #else
520 
521 #define nfs4_close_state(a, b) do { } while (0)
522 #define nfs4_close_sync(a, b) do { } while (0)
523 #define nfs4_state_protect(a, b, c, d) do { } while (0)
524 #define nfs4_state_protect_write(a, b, c, d) do { } while (0)
525 
526 #endif /* CONFIG_NFS_V4 */
527 #endif /* __LINUX_FS_NFS_NFS4_FS.H */
528