xref: /openbmc/linux/fs/nfs/nfs4_fs.h (revision 49706474)
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 	NFS4CLNT_RUN_MANAGER,
45 	NFS4CLNT_RECALL_RUNNING,
46 	NFS4CLNT_RECALL_ANY_LAYOUT_READ,
47 	NFS4CLNT_RECALL_ANY_LAYOUT_RW,
48 	NFS4CLNT_DELEGRETURN_DELAYED,
49 };
50 
51 #define NFS4_RENEW_TIMEOUT		0x01
52 #define NFS4_RENEW_DELEGATION_CB	0x02
53 
54 struct nfs_seqid_counter;
55 struct nfs4_minor_version_ops {
56 	u32	minor_version;
57 	unsigned init_caps;
58 
59 	int	(*init_client)(struct nfs_client *);
60 	void	(*shutdown_client)(struct nfs_client *);
61 	bool	(*match_stateid)(const nfs4_stateid *,
62 			const nfs4_stateid *);
63 	int	(*find_root_sec)(struct nfs_server *, struct nfs_fh *,
64 			struct nfs_fsinfo *);
65 	void	(*free_lock_state)(struct nfs_server *,
66 			struct nfs4_lock_state *);
67 	int	(*test_and_free_expired)(struct nfs_server *,
68 			nfs4_stateid *, const struct cred *);
69 	struct nfs_seqid *
70 		(*alloc_seqid)(struct nfs_seqid_counter *, gfp_t);
71 	void	(*session_trunk)(struct rpc_clnt *clnt,
72 			struct rpc_xprt *xprt, void *data);
73 	const struct rpc_call_ops *call_sync_ops;
74 	const struct nfs4_state_recovery_ops *reboot_recovery_ops;
75 	const struct nfs4_state_recovery_ops *nograce_recovery_ops;
76 	const struct nfs4_state_maintenance_ops *state_renewal_ops;
77 	const struct nfs4_mig_recovery_ops *mig_recovery_ops;
78 };
79 
80 #define NFS_SEQID_CONFIRMED 1
81 struct nfs_seqid_counter {
82 	ktime_t create_time;
83 	int owner_id;
84 	int flags;
85 	u32 counter;
86 	spinlock_t lock;		/* Protects the list */
87 	struct list_head list;		/* Defines sequence of RPC calls */
88 	struct rpc_wait_queue	wait;	/* RPC call delay queue */
89 };
90 
91 struct nfs_seqid {
92 	struct nfs_seqid_counter *sequence;
93 	struct list_head list;
94 	struct rpc_task *task;
95 };
96 
97 static inline void nfs_confirm_seqid(struct nfs_seqid_counter *seqid, int status)
98 {
99 	if (seqid_mutating_err(-status))
100 		seqid->flags |= NFS_SEQID_CONFIRMED;
101 }
102 
103 /*
104  * NFS4 state_owners and lock_owners are simply labels for ordered
105  * sequences of RPC calls. Their sole purpose is to provide once-only
106  * semantics by allowing the server to identify replayed requests.
107  */
108 struct nfs4_state_owner {
109 	struct nfs_server    *so_server;
110 	struct list_head     so_lru;
111 	unsigned long        so_expires;
112 	struct rb_node	     so_server_node;
113 
114 	const struct cred    *so_cred;	 /* Associated cred */
115 
116 	spinlock_t	     so_lock;
117 	atomic_t	     so_count;
118 	unsigned long	     so_flags;
119 	struct list_head     so_states;
120 	struct nfs_seqid_counter so_seqid;
121 	seqcount_spinlock_t  so_reclaim_seqcount;
122 	struct mutex	     so_delegreturn_mutex;
123 };
124 
125 enum {
126 	NFS_OWNER_RECLAIM_REBOOT,
127 	NFS_OWNER_RECLAIM_NOGRACE
128 };
129 
130 #define NFS_LOCK_NEW		0
131 #define NFS_LOCK_RECLAIM	1
132 #define NFS_LOCK_EXPIRED	2
133 
134 /*
135  * struct nfs4_state maintains the client-side state for a given
136  * (state_owner,inode) tuple (OPEN) or state_owner (LOCK).
137  *
138  * OPEN:
139  * In order to know when to OPEN_DOWNGRADE or CLOSE the state on the server,
140  * we need to know how many files are open for reading or writing on a
141  * given inode. This information too is stored here.
142  *
143  * LOCK: one nfs4_state (LOCK) to hold the lock stateid nfs4_state(OPEN)
144  */
145 
146 struct nfs4_lock_state {
147 	struct list_head	ls_locks;	/* Other lock stateids */
148 	struct nfs4_state *	ls_state;	/* Pointer to open state */
149 #define NFS_LOCK_INITIALIZED 0
150 #define NFS_LOCK_LOST        1
151 	unsigned long		ls_flags;
152 	struct nfs_seqid_counter	ls_seqid;
153 	nfs4_stateid		ls_stateid;
154 	refcount_t		ls_count;
155 	fl_owner_t		ls_owner;
156 };
157 
158 /* bits for nfs4_state->flags */
159 enum {
160 	LK_STATE_IN_USE,
161 	NFS_DELEGATED_STATE,		/* Current stateid is delegation */
162 	NFS_OPEN_STATE,			/* OPEN stateid is set */
163 	NFS_O_RDONLY_STATE,		/* OPEN stateid has read-only state */
164 	NFS_O_WRONLY_STATE,		/* OPEN stateid has write-only state */
165 	NFS_O_RDWR_STATE,		/* OPEN stateid has read/write state */
166 	NFS_STATE_RECLAIM_REBOOT,	/* OPEN stateid server rebooted */
167 	NFS_STATE_RECLAIM_NOGRACE,	/* OPEN stateid needs to recover state */
168 	NFS_STATE_POSIX_LOCKS,		/* Posix locks are supported */
169 	NFS_STATE_RECOVERY_FAILED,	/* OPEN stateid state recovery failed */
170 	NFS_STATE_MAY_NOTIFY_LOCK,	/* server may CB_NOTIFY_LOCK */
171 	NFS_STATE_CHANGE_WAIT,		/* A state changing operation is outstanding */
172 	NFS_CLNT_DST_SSC_COPY_STATE,    /* dst server open state on client*/
173 	NFS_CLNT_SRC_SSC_COPY_STATE,    /* src server open state on client*/
174 	NFS_SRV_SSC_COPY_STATE,		/* ssc state on the dst server */
175 };
176 
177 struct nfs4_state {
178 	struct list_head open_states;	/* List of states for the same state_owner */
179 	struct list_head inode_states;	/* List of states for the same inode */
180 	struct list_head lock_states;	/* List of subservient lock stateids */
181 
182 	struct nfs4_state_owner *owner;	/* Pointer to the open owner */
183 	struct inode *inode;		/* Pointer to the inode */
184 
185 	unsigned long flags;		/* Do we hold any locks? */
186 	spinlock_t state_lock;		/* Protects the lock_states list */
187 
188 	seqlock_t seqlock;		/* Protects the stateid/open_stateid */
189 	nfs4_stateid stateid;		/* Current stateid: may be delegation */
190 	nfs4_stateid open_stateid;	/* OPEN stateid */
191 
192 	/* The following 3 fields are protected by owner->so_lock */
193 	unsigned int n_rdonly;		/* Number of read-only references */
194 	unsigned int n_wronly;		/* Number of write-only references */
195 	unsigned int n_rdwr;		/* Number of read/write references */
196 	fmode_t state;			/* State on the server (R,W, or RW) */
197 	refcount_t count;
198 
199 	wait_queue_head_t waitq;
200 	struct rcu_head rcu_head;
201 };
202 
203 
204 struct nfs4_exception {
205 	struct nfs4_state *state;
206 	struct inode *inode;
207 	nfs4_stateid *stateid;
208 	long timeout;
209 	unsigned char task_is_privileged : 1;
210 	unsigned char delay : 1,
211 		      recovering : 1,
212 		      retry : 1;
213 	bool interruptible;
214 };
215 
216 struct nfs4_state_recovery_ops {
217 	int owner_flag_bit;
218 	int state_flag_bit;
219 	int (*recover_open)(struct nfs4_state_owner *, struct nfs4_state *);
220 	int (*recover_lock)(struct nfs4_state *, struct file_lock *);
221 	int (*establish_clid)(struct nfs_client *, const struct cred *);
222 	int (*reclaim_complete)(struct nfs_client *, const struct cred *);
223 	int (*detect_trunking)(struct nfs_client *, struct nfs_client **,
224 		const struct cred *);
225 };
226 
227 struct nfs4_opendata {
228 	struct kref kref;
229 	struct nfs_openargs o_arg;
230 	struct nfs_openres o_res;
231 	struct nfs_open_confirmargs c_arg;
232 	struct nfs_open_confirmres c_res;
233 	struct nfs4_string owner_name;
234 	struct nfs4_string group_name;
235 	struct nfs4_label *a_label;
236 	struct nfs_fattr f_attr;
237 	struct nfs4_label *f_label;
238 	struct dentry *dir;
239 	struct dentry *dentry;
240 	struct nfs4_state_owner *owner;
241 	struct nfs4_state *state;
242 	struct iattr attrs;
243 	struct nfs4_layoutget *lgp;
244 	unsigned long timestamp;
245 	bool rpc_done;
246 	bool file_created;
247 	bool is_recover;
248 	bool cancelled;
249 	int rpc_status;
250 };
251 
252 struct nfs4_add_xprt_data {
253 	struct nfs_client	*clp;
254 	const struct cred	*cred;
255 };
256 
257 struct nfs4_state_maintenance_ops {
258 	int (*sched_state_renewal)(struct nfs_client *, const struct cred *, unsigned);
259 	const struct cred * (*get_state_renewal_cred)(struct nfs_client *);
260 	int (*renew_lease)(struct nfs_client *, const struct cred *);
261 };
262 
263 struct nfs4_mig_recovery_ops {
264 	int (*get_locations)(struct inode *, struct nfs4_fs_locations *,
265 		struct page *, const struct cred *);
266 	int (*fsid_present)(struct inode *, const struct cred *);
267 };
268 
269 extern const struct dentry_operations nfs4_dentry_operations;
270 
271 /* dir.c */
272 int nfs_atomic_open(struct inode *, struct dentry *, struct file *,
273 		    unsigned, umode_t);
274 
275 /* fs_context.c */
276 extern struct file_system_type nfs4_fs_type;
277 
278 /* nfs4namespace.c */
279 struct rpc_clnt *nfs4_negotiate_security(struct rpc_clnt *, struct inode *,
280 					 const struct qstr *);
281 int nfs4_submount(struct fs_context *, struct nfs_server *);
282 int nfs4_replace_transport(struct nfs_server *server,
283 				const struct nfs4_fs_locations *locations);
284 
285 /* nfs4proc.c */
286 extern int nfs4_handle_exception(struct nfs_server *, int, struct nfs4_exception *);
287 extern int nfs4_async_handle_error(struct rpc_task *task,
288 				   struct nfs_server *server,
289 				   struct nfs4_state *state, long *timeout);
290 extern int nfs4_call_sync(struct rpc_clnt *, struct nfs_server *,
291 			  struct rpc_message *, struct nfs4_sequence_args *,
292 			  struct nfs4_sequence_res *, int);
293 extern void nfs4_init_sequence(struct nfs4_sequence_args *, struct nfs4_sequence_res *, int, int);
294 extern int nfs4_proc_setclientid(struct nfs_client *, u32, unsigned short, const struct cred *, struct nfs4_setclientid_res *);
295 extern int nfs4_proc_setclientid_confirm(struct nfs_client *, struct nfs4_setclientid_res *arg, const struct cred *);
296 extern int nfs4_proc_get_rootfh(struct nfs_server *, struct nfs_fh *, struct nfs_fsinfo *, bool);
297 extern int nfs4_proc_bind_conn_to_session(struct nfs_client *, const struct cred *cred);
298 extern int nfs4_proc_exchange_id(struct nfs_client *clp, const struct cred *cred);
299 extern int nfs4_destroy_clientid(struct nfs_client *clp);
300 extern int nfs4_init_clientid(struct nfs_client *, const struct cred *);
301 extern int nfs41_init_clientid(struct nfs_client *, const struct cred *);
302 extern int nfs4_do_close(struct nfs4_state *state, gfp_t gfp_mask, int wait);
303 extern int nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *fhandle);
304 extern int nfs4_proc_fs_locations(struct rpc_clnt *, struct inode *, const struct qstr *,
305 				  struct nfs4_fs_locations *, struct page *);
306 extern int nfs4_proc_get_locations(struct inode *, struct nfs4_fs_locations *,
307 		struct page *page, const struct cred *);
308 extern int nfs4_proc_fsid_present(struct inode *, const struct cred *);
309 extern struct rpc_clnt *nfs4_proc_lookup_mountpoint(struct inode *,
310 						    struct dentry *,
311 						    struct nfs_fh *,
312 						    struct nfs_fattr *);
313 extern int nfs4_proc_secinfo(struct inode *, const struct qstr *, struct nfs4_secinfo_flavors *);
314 extern const struct xattr_handler *nfs4_xattr_handlers[];
315 extern int nfs4_set_rw_stateid(nfs4_stateid *stateid,
316 		const struct nfs_open_context *ctx,
317 		const struct nfs_lock_context *l_ctx,
318 		fmode_t fmode);
319 extern int nfs4_proc_getattr(struct nfs_server *server, struct nfs_fh *fhandle,
320 			     struct nfs_fattr *fattr, struct nfs4_label *label,
321 			     struct inode *inode);
322 extern int update_open_stateid(struct nfs4_state *state,
323 				const nfs4_stateid *open_stateid,
324 				const nfs4_stateid *deleg_stateid,
325 				fmode_t fmode);
326 
327 extern int nfs4_proc_get_lease_time(struct nfs_client *clp,
328 		struct nfs_fsinfo *fsinfo);
329 extern void nfs4_update_changeattr(struct inode *dir,
330 				   struct nfs4_change_info *cinfo,
331 				   unsigned long timestamp,
332 				   unsigned long cache_validity);
333 extern int nfs4_buf_to_pages_noslab(const void *buf, size_t buflen,
334 				    struct page **pages);
335 
336 #if defined(CONFIG_NFS_V4_1)
337 extern int nfs41_sequence_done(struct rpc_task *, struct nfs4_sequence_res *);
338 extern int nfs4_proc_create_session(struct nfs_client *, const struct cred *);
339 extern int nfs4_proc_destroy_session(struct nfs4_session *, const struct cred *);
340 extern int nfs4_proc_layoutcommit(struct nfs4_layoutcommit_data *data,
341 				  bool sync);
342 extern int nfs4_detect_session_trunking(struct nfs_client *clp,
343 		struct nfs41_exchange_id_res *res, struct rpc_xprt *xprt);
344 
345 static inline bool
346 is_ds_only_client(struct nfs_client *clp)
347 {
348 	return (clp->cl_exchange_flags & EXCHGID4_FLAG_MASK_PNFS) ==
349 		EXCHGID4_FLAG_USE_PNFS_DS;
350 }
351 
352 static inline bool
353 is_ds_client(struct nfs_client *clp)
354 {
355 	return clp->cl_exchange_flags & EXCHGID4_FLAG_USE_PNFS_DS;
356 }
357 
358 static inline bool
359 _nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_mode,
360 		    struct rpc_clnt **clntp, struct rpc_message *msg)
361 {
362 	rpc_authflavor_t flavor;
363 
364 	if (sp4_mode == NFS_SP4_MACH_CRED_CLEANUP ||
365 	    sp4_mode == NFS_SP4_MACH_CRED_PNFS_CLEANUP) {
366 		/* Using machine creds for cleanup operations
367 		 * is only relevent if the client credentials
368 		 * might expire. So don't bother for
369 		 * RPC_AUTH_UNIX.  If file was only exported to
370 		 * sec=sys, the PUTFH would fail anyway.
371 		 */
372 		if ((*clntp)->cl_auth->au_flavor == RPC_AUTH_UNIX)
373 			return false;
374 	}
375 	if (test_bit(sp4_mode, &clp->cl_sp4_flags)) {
376 		msg->rpc_cred = rpc_machine_cred();
377 
378 		flavor = clp->cl_rpcclient->cl_auth->au_flavor;
379 		WARN_ON_ONCE(flavor != RPC_AUTH_GSS_KRB5I &&
380 			     flavor != RPC_AUTH_GSS_KRB5P);
381 		*clntp = clp->cl_rpcclient;
382 
383 		return true;
384 	}
385 	return false;
386 }
387 
388 /*
389  * Function responsible for determining if an rpc_message should use the
390  * machine cred under SP4_MACH_CRED and if so switching the credential and
391  * authflavor (using the nfs_client's rpc_clnt which will be krb5i/p).
392  * Should be called before rpc_call_sync/rpc_call_async.
393  */
394 static inline void
395 nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_mode,
396 		   struct rpc_clnt **clntp, struct rpc_message *msg)
397 {
398 	_nfs4_state_protect(clp, sp4_mode, clntp, msg);
399 }
400 
401 /*
402  * Special wrapper to nfs4_state_protect for write.
403  * If WRITE can use machine cred but COMMIT cannot, make sure all writes
404  * that use machine cred use NFS_FILE_SYNC.
405  */
406 static inline void
407 nfs4_state_protect_write(struct nfs_client *clp, struct rpc_clnt **clntp,
408 			 struct rpc_message *msg, struct nfs_pgio_header *hdr)
409 {
410 	if (_nfs4_state_protect(clp, NFS_SP4_MACH_CRED_WRITE, clntp, msg) &&
411 	    !test_bit(NFS_SP4_MACH_CRED_COMMIT, &clp->cl_sp4_flags))
412 		hdr->args.stable = NFS_FILE_SYNC;
413 }
414 #else /* CONFIG_NFS_v4_1 */
415 static inline bool
416 is_ds_only_client(struct nfs_client *clp)
417 {
418 	return false;
419 }
420 
421 static inline bool
422 is_ds_client(struct nfs_client *clp)
423 {
424 	return false;
425 }
426 
427 static inline void
428 nfs4_state_protect(struct nfs_client *clp, unsigned long sp4_flags,
429 		   struct rpc_clnt **clntp, struct rpc_message *msg)
430 {
431 }
432 
433 static inline void
434 nfs4_state_protect_write(struct nfs_client *clp, struct rpc_clnt **clntp,
435 			 struct rpc_message *msg, struct nfs_pgio_header *hdr)
436 {
437 }
438 #endif /* CONFIG_NFS_V4_1 */
439 
440 extern const struct nfs4_minor_version_ops *nfs_v4_minor_ops[];
441 
442 extern const u32 nfs4_fattr_bitmap[3];
443 extern const u32 nfs4_statfs_bitmap[3];
444 extern const u32 nfs4_pathconf_bitmap[3];
445 extern const u32 nfs4_fsinfo_bitmap[3];
446 extern const u32 nfs4_fs_locations_bitmap[3];
447 
448 void nfs40_shutdown_client(struct nfs_client *);
449 void nfs41_shutdown_client(struct nfs_client *);
450 int nfs40_init_client(struct nfs_client *);
451 int nfs41_init_client(struct nfs_client *);
452 void nfs4_free_client(struct nfs_client *);
453 
454 struct nfs_client *nfs4_alloc_client(const struct nfs_client_initdata *);
455 
456 /* nfs4renewd.c */
457 extern void nfs4_schedule_state_renewal(struct nfs_client *);
458 extern void nfs4_renewd_prepare_shutdown(struct nfs_server *);
459 extern void nfs4_kill_renewd(struct nfs_client *);
460 extern void nfs4_renew_state(struct work_struct *);
461 extern void nfs4_set_lease_period(struct nfs_client *clp, unsigned long lease);
462 
463 
464 /* nfs4state.c */
465 extern const nfs4_stateid current_stateid;
466 
467 const struct cred *nfs4_get_clid_cred(struct nfs_client *clp);
468 const struct cred *nfs4_get_machine_cred(struct nfs_client *clp);
469 const struct cred *nfs4_get_renew_cred(struct nfs_client *clp);
470 int nfs4_discover_server_trunking(struct nfs_client *clp,
471 			struct nfs_client **);
472 int nfs40_discover_server_trunking(struct nfs_client *clp,
473 			struct nfs_client **, const struct cred *);
474 #if defined(CONFIG_NFS_V4_1)
475 int nfs41_discover_server_trunking(struct nfs_client *clp,
476 			struct nfs_client **, const struct cred *);
477 extern void nfs4_schedule_session_recovery(struct nfs4_session *, int);
478 extern void nfs41_notify_server(struct nfs_client *);
479 bool nfs4_check_serverowner_major_id(struct nfs41_server_owner *o1,
480 			struct nfs41_server_owner *o2);
481 #else
482 static inline void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
483 {
484 }
485 #endif /* CONFIG_NFS_V4_1 */
486 
487 extern struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *, const struct cred *, gfp_t);
488 extern void nfs4_put_state_owner(struct nfs4_state_owner *);
489 extern void nfs4_purge_state_owners(struct nfs_server *, struct list_head *);
490 extern void nfs4_free_state_owners(struct list_head *head);
491 extern struct nfs4_state * nfs4_get_open_state(struct inode *, struct nfs4_state_owner *);
492 extern void nfs4_put_open_state(struct nfs4_state *);
493 extern void nfs4_close_state(struct nfs4_state *, fmode_t);
494 extern void nfs4_close_sync(struct nfs4_state *, fmode_t);
495 extern void nfs4_state_set_mode_locked(struct nfs4_state *, fmode_t);
496 extern void nfs_inode_find_state_and_recover(struct inode *inode,
497 		const nfs4_stateid *stateid);
498 extern int nfs4_state_mark_reclaim_nograce(struct nfs_client *, struct nfs4_state *);
499 extern void nfs4_schedule_lease_recovery(struct nfs_client *);
500 extern int nfs4_wait_clnt_recover(struct nfs_client *clp);
501 extern int nfs4_client_recover_expired_lease(struct nfs_client *clp);
502 extern void nfs4_schedule_state_manager(struct nfs_client *);
503 extern void nfs4_schedule_path_down_recovery(struct nfs_client *clp);
504 extern int nfs4_schedule_stateid_recovery(const struct nfs_server *, struct nfs4_state *);
505 extern int nfs4_schedule_migration_recovery(const struct nfs_server *);
506 extern void nfs4_schedule_lease_moved_recovery(struct nfs_client *);
507 extern void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags, bool);
508 extern void nfs41_handle_server_scope(struct nfs_client *,
509 				      struct nfs41_server_scope **);
510 extern void nfs4_put_lock_state(struct nfs4_lock_state *lsp);
511 extern int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl);
512 extern int nfs4_select_rw_stateid(struct nfs4_state *, fmode_t,
513 		const struct nfs_lock_context *, nfs4_stateid *,
514 		const struct cred **);
515 extern bool nfs4_copy_open_stateid(nfs4_stateid *dst,
516 		struct nfs4_state *state);
517 
518 extern struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask);
519 extern int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task);
520 extern void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid);
521 extern void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid);
522 extern void nfs_release_seqid(struct nfs_seqid *seqid);
523 extern void nfs_free_seqid(struct nfs_seqid *seqid);
524 extern int nfs4_setup_sequence(struct nfs_client *client,
525 				struct nfs4_sequence_args *args,
526 				struct nfs4_sequence_res *res,
527 				struct rpc_task *task);
528 extern int nfs4_sequence_done(struct rpc_task *task,
529 			      struct nfs4_sequence_res *res);
530 
531 extern void nfs4_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp);
532 extern int nfs4_proc_commit(struct file *dst, __u64 offset, __u32 count, struct nfs_commitres *res);
533 extern const nfs4_stateid zero_stateid;
534 extern const nfs4_stateid invalid_stateid;
535 
536 /* nfs4super.c */
537 struct nfs_mount_info;
538 extern struct nfs_subversion nfs_v4;
539 extern bool nfs4_disable_idmapping;
540 extern unsigned short max_session_slots;
541 extern unsigned short max_session_cb_slots;
542 extern unsigned short send_implementation_id;
543 extern bool recover_lost_locks;
544 
545 #define NFS4_CLIENT_ID_UNIQ_LEN		(64)
546 extern char nfs4_client_id_uniquifier[NFS4_CLIENT_ID_UNIQ_LEN];
547 
548 extern int nfs4_try_get_tree(struct fs_context *);
549 extern int nfs4_get_referral_tree(struct fs_context *);
550 
551 /* nfs4sysctl.c */
552 #ifdef CONFIG_SYSCTL
553 int nfs4_register_sysctl(void);
554 void nfs4_unregister_sysctl(void);
555 #else
556 static inline int nfs4_register_sysctl(void)
557 {
558 	return 0;
559 }
560 
561 static inline void nfs4_unregister_sysctl(void)
562 {
563 }
564 #endif
565 
566 /* nfs4xdr.c */
567 extern const struct rpc_procinfo nfs4_procedures[];
568 
569 #ifdef CONFIG_NFS_V4_2
570 extern const u32 nfs42_maxsetxattr_overhead;
571 extern const u32 nfs42_maxgetxattr_overhead;
572 extern const u32 nfs42_maxlistxattrs_overhead;
573 #endif
574 
575 struct nfs4_mount_data;
576 
577 /* callback_xdr.c */
578 extern const struct svc_version nfs4_callback_version1;
579 extern const struct svc_version nfs4_callback_version4;
580 
581 static inline void nfs4_stateid_copy(nfs4_stateid *dst, const nfs4_stateid *src)
582 {
583 	memcpy(dst->data, src->data, sizeof(dst->data));
584 	dst->type = src->type;
585 }
586 
587 static inline bool nfs4_stateid_match(const nfs4_stateid *dst, const nfs4_stateid *src)
588 {
589 	if (dst->type != src->type)
590 		return false;
591 	return memcmp(dst->data, src->data, sizeof(dst->data)) == 0;
592 }
593 
594 static inline bool nfs4_stateid_match_other(const nfs4_stateid *dst, const nfs4_stateid *src)
595 {
596 	return memcmp(dst->other, src->other, NFS4_STATEID_OTHER_SIZE) == 0;
597 }
598 
599 static inline bool nfs4_stateid_is_newer(const nfs4_stateid *s1, const nfs4_stateid *s2)
600 {
601 	return (s32)(be32_to_cpu(s1->seqid) - be32_to_cpu(s2->seqid)) > 0;
602 }
603 
604 static inline bool nfs4_stateid_is_next(const nfs4_stateid *s1, const nfs4_stateid *s2)
605 {
606 	u32 seq1 = be32_to_cpu(s1->seqid);
607 	u32 seq2 = be32_to_cpu(s2->seqid);
608 
609 	return seq2 == seq1 + 1U || (seq2 == 1U && seq1 == 0xffffffffU);
610 }
611 
612 static inline bool nfs4_stateid_match_or_older(const nfs4_stateid *dst, const nfs4_stateid *src)
613 {
614 	return nfs4_stateid_match_other(dst, src) &&
615 		!(src->seqid && nfs4_stateid_is_newer(dst, src));
616 }
617 
618 static inline void nfs4_stateid_seqid_inc(nfs4_stateid *s1)
619 {
620 	u32 seqid = be32_to_cpu(s1->seqid);
621 
622 	if (++seqid == 0)
623 		++seqid;
624 	s1->seqid = cpu_to_be32(seqid);
625 }
626 
627 static inline bool nfs4_valid_open_stateid(const struct nfs4_state *state)
628 {
629 	return test_bit(NFS_STATE_RECOVERY_FAILED, &state->flags) == 0;
630 }
631 
632 static inline bool nfs4_state_match_open_stateid_other(const struct nfs4_state *state,
633 		const nfs4_stateid *stateid)
634 {
635 	return test_bit(NFS_OPEN_STATE, &state->flags) &&
636 		nfs4_stateid_match_other(&state->open_stateid, stateid);
637 }
638 
639 /* nfs42xattr.c */
640 #ifdef CONFIG_NFS_V4_2
641 extern int __init nfs4_xattr_cache_init(void);
642 extern void nfs4_xattr_cache_exit(void);
643 extern void nfs4_xattr_cache_add(struct inode *inode, const char *name,
644 				 const char *buf, struct page **pages,
645 				 ssize_t buflen);
646 extern void nfs4_xattr_cache_remove(struct inode *inode, const char *name);
647 extern ssize_t nfs4_xattr_cache_get(struct inode *inode, const char *name,
648 				char *buf, ssize_t buflen);
649 extern void nfs4_xattr_cache_set_list(struct inode *inode, const char *buf,
650 				      ssize_t buflen);
651 extern ssize_t nfs4_xattr_cache_list(struct inode *inode, char *buf,
652 				     ssize_t buflen);
653 extern void nfs4_xattr_cache_zap(struct inode *inode);
654 #else
655 static inline void nfs4_xattr_cache_zap(struct inode *inode)
656 {
657 }
658 #endif /* CONFIG_NFS_V4_2 */
659 
660 #else /* CONFIG_NFS_V4 */
661 
662 #define nfs4_close_state(a, b) do { } while (0)
663 #define nfs4_close_sync(a, b) do { } while (0)
664 #define nfs4_state_protect(a, b, c, d) do { } while (0)
665 #define nfs4_state_protect_write(a, b, c, d) do { } while (0)
666 
667 
668 #endif /* CONFIG_NFS_V4 */
669 #endif /* __LINUX_FS_NFS_NFS4_FS.H */
670