xref: /linux/fs/nfsd/state.h (revision 42cc13995967c1f3790cb106916eed8fab2a37b1)
1 /*
2  *  Copyright (c) 2001 The Regents of the University of Michigan.
3  *  All rights reserved.
4  *
5  *  Kendrick Smith <kmsmith@umich.edu>
6  *  Andy Adamson <andros@umich.edu>
7  *
8  *  Redistribution and use in source and binary forms, with or without
9  *  modification, are permitted provided that the following conditions
10  *  are met:
11  *
12  *  1. Redistributions of source code must retain the above copyright
13  *     notice, this list of conditions and the following disclaimer.
14  *  2. Redistributions in binary form must reproduce the above copyright
15  *     notice, this list of conditions and the following disclaimer in the
16  *     documentation and/or other materials provided with the distribution.
17  *  3. Neither the name of the University nor the names of its
18  *     contributors may be used to endorse or promote products derived
19  *     from this software without specific prior written permission.
20  *
21  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
22  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
23  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
24  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
26  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
27  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
28  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
29  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
30  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
31  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  *
33  */
34 
35 #ifndef _NFSD4_STATE_H
36 #define _NFSD4_STATE_H
37 
38 #include <crypto/md5.h>
39 #include <linux/idr.h>
40 #include <linux/refcount.h>
41 #include <linux/sunrpc/svc_xprt.h>
42 #include "nfsfh.h"
43 #include "nfsd.h"
44 
45 typedef struct {
46 	u32             cl_boot;
47 	u32             cl_id;
48 } clientid_t;
49 
50 typedef struct {
51 	clientid_t	so_clid;
52 	u32		so_id;
53 } stateid_opaque_t;
54 
55 typedef struct {
56 	u32                     si_generation;
57 	stateid_opaque_t        si_opaque;
58 } stateid_t;
59 
60 typedef struct {
61 	stateid_t		cs_stid;
62 #define NFS4_COPY_STID 1
63 #define NFS4_COPYNOTIFY_STID 2
64 	unsigned char		cs_type;
65 	refcount_t		cs_count;
66 } copy_stateid_t;
67 
68 struct nfsd4_referring_call {
69 	struct list_head	__list;
70 
71 	u32			rc_sequenceid;
72 	u32			rc_slotid;
73 };
74 
75 struct nfsd4_referring_call_list {
76 	struct list_head	__list;
77 
78 	struct nfs4_sessionid	rcl_sessionid;
79 	int			__nr_referring_calls;
80 	struct list_head	rcl_referring_calls;
81 };
82 
83 struct nfsd4_callback {
84 	struct nfs4_client *cb_clp;
85 	struct rpc_message cb_msg;
86 #define NFSD4_CALLBACK_RUNNING		(0)
87 #define NFSD4_CALLBACK_WAKE		(1)
88 #define NFSD4_CALLBACK_REQUEUE		(2)
89 	unsigned long cb_flags;
90 	const struct nfsd4_callback_ops *cb_ops;
91 	struct work_struct cb_work;
92 	int cb_seq_status;
93 	int cb_status;
94 	int cb_held_slot;
95 
96 	int cb_nr_referring_call_list;
97 	struct list_head cb_referring_call_list;
98 };
99 
100 struct nfsd4_callback_ops {
101 	void (*prepare)(struct nfsd4_callback *);
102 	int (*done)(struct nfsd4_callback *, struct rpc_task *);
103 	void (*release)(struct nfsd4_callback *);
104 	uint32_t opcode;
105 };
106 
107 /*
108  * A core object that represents a "common" stateid. These are generally
109  * embedded within the different (more specific) stateid objects and contain
110  * fields that are of general use to any stateid.
111  */
112 struct nfs4_stid {
113 	refcount_t		sc_count;
114 
115 	/* A new stateid is added to the cl_stateids idr early before it
116 	 * is fully initialised.  Its sc_type is then zero.  After
117 	 * initialisation the sc_type it set under cl_lock, and then
118 	 * never changes.
119 	 */
120 #define SC_TYPE_OPEN		BIT(0)
121 #define SC_TYPE_LOCK		BIT(1)
122 #define SC_TYPE_DELEG		BIT(2)
123 #define SC_TYPE_LAYOUT		BIT(3)
124 	unsigned short		sc_type;
125 
126 /* nn->deleg_lock protects sc_status for delegation stateids.
127  * ->cl_lock protects sc_status for open and lock stateids.
128  * ->st_mutex also protect sc_status for open stateids.
129  * ->ls_lock protects sc_status for layout stateids.
130  */
131 /*
132  * For an open stateid kept around *only* to process close replays.
133  * For deleg stateid, kept in idr until last reference is dropped.
134  */
135 #define SC_STATUS_CLOSED	BIT(0)
136 /* For a deleg stateid kept around only to process free_stateid's: */
137 #define SC_STATUS_REVOKED	BIT(1)
138 #define SC_STATUS_ADMIN_REVOKED	BIT(2)
139 #define SC_STATUS_FREEABLE	BIT(3)
140 #define SC_STATUS_FREED		BIT(4)
141 	unsigned short		sc_status;
142 
143 	struct list_head	sc_cp_list;
144 	stateid_t		sc_stateid;
145 	spinlock_t		sc_lock;
146 	struct nfs4_client	*sc_client;
147 	struct nfs4_file	*sc_file;
148 	void			(*sc_free)(struct nfs4_stid *);
149 };
150 
151 /* Keep a list of stateids issued by the COPY_NOTIFY, associate it with the
152  * parent OPEN/LOCK/DELEG stateid.
153  */
154 struct nfs4_cpntf_state {
155 	copy_stateid_t		cp_stateid;
156 	struct list_head	cp_list;	/* per parent nfs4_stid */
157 	stateid_t		cp_p_stateid;	/* copy of parent's stateid */
158 	clientid_t		cp_p_clid;	/* copy of parent's clid */
159 	time64_t		cpntf_time;	/* last time stateid used */
160 };
161 
162 /*
163  * RFC 7862 Section 4.8 states:
164  *
165  * | A copy offload stateid will be valid until either (A) the client
166  * | or server restarts or (B) the client returns the resource by
167  * | issuing an OFFLOAD_CANCEL operation or the client replies to a
168  * | CB_OFFLOAD operation.
169  *
170  * Because a client might not reply to a CB_OFFLOAD, or a reply
171  * might get lost due to connection loss, NFSD purges async copy
172  * state after a short period to prevent it from accumulating
173  * over time.
174  */
175 #define NFSD_COPY_INITIAL_TTL 10
176 
177 struct nfs4_cb_fattr {
178 	struct nfsd4_callback ncf_getattr;
179 	u32 ncf_cb_status;
180 
181 	/* from CB_GETATTR reply */
182 	u64 ncf_cb_change;
183 	u64 ncf_cb_fsize;
184 	struct timespec64 ncf_cb_mtime;
185 	struct timespec64 ncf_cb_atime;
186 
187 	bool ncf_file_modified;
188 	u64 ncf_initial_cinfo;
189 	u64 ncf_cur_fsize;
190 };
191 
192 /*
193  * Represents a delegation stateid. The nfs4_client holds references to these
194  * and they are put when it is being destroyed or when the delegation is
195  * returned by the client:
196  *
197  * o 1 reference as long as a delegation is still in force (taken when it's
198  *   alloc'd, put when it's returned or revoked)
199  *
200  * o 1 reference as long as a recall rpc is in progress (taken when the lease
201  *   is broken, put when the rpc exits)
202  *
203  * o 1 more ephemeral reference for each nfsd thread currently doing something
204  *   with that delegation without holding the cl_lock
205  *
206  * If the server attempts to recall a delegation and the client doesn't do so
207  * before a timeout, the server may also revoke the delegation. In that case,
208  * the object will either be destroyed (v4.0) or moved to a per-client list of
209  * revoked delegations (v4.1+).
210  *
211  * This object is a superset of the nfs4_stid.
212  */
213 struct nfs4_delegation {
214 	struct nfs4_stid	dl_stid; /* must be first field */
215 	struct list_head	dl_perfile;
216 	struct list_head	dl_perclnt;
217 	struct list_head	dl_recall_lru;  /* delegation recalled */
218 	struct nfs4_clnt_odstate *dl_clnt_odstate;
219 	time64_t		dl_time;
220 	u32			dl_type;
221 	/* For recall: */
222 	int			dl_retries;
223 	struct nfsd4_callback	dl_recall;
224 	bool			dl_recalled;
225 	bool			dl_written;
226 	bool			dl_setattr;
227 
228 	/* for CB_GETATTR */
229 	struct nfs4_cb_fattr    dl_cb_fattr;
230 
231 	/* For delegated timestamps */
232 	struct timespec64	dl_atime;
233 	struct timespec64	dl_mtime;
234 	struct timespec64	dl_ctime;
235 };
236 
237 static inline bool deleg_is_read(u32 dl_type)
238 {
239 	return (dl_type == OPEN_DELEGATE_READ || dl_type == OPEN_DELEGATE_READ_ATTRS_DELEG);
240 }
241 
242 static inline bool deleg_is_write(u32 dl_type)
243 {
244 	return (dl_type == OPEN_DELEGATE_WRITE || dl_type == OPEN_DELEGATE_WRITE_ATTRS_DELEG);
245 }
246 
247 static inline bool deleg_attrs_deleg(u32 dl_type)
248 {
249 	return dl_type == OPEN_DELEGATE_READ_ATTRS_DELEG ||
250 	       dl_type == OPEN_DELEGATE_WRITE_ATTRS_DELEG;
251 }
252 
253 bool nfsd4_vet_deleg_time(struct timespec64 *cb, const struct timespec64 *orig,
254 			  const struct timespec64 *now);
255 
256 #define cb_to_delegation(cb) \
257 	container_of(cb, struct nfs4_delegation, dl_recall)
258 
259 /* client delegation callback info */
260 struct nfs4_cb_conn {
261 	/* SETCLIENTID info */
262 	struct sockaddr_storage	cb_addr;
263 	struct sockaddr_storage	cb_saddr;
264 	size_t			cb_addrlen;
265 	u32                     cb_prog; /* used only in 4.0 case;
266 					    per-session otherwise */
267 	u32                     cb_ident;	/* minorversion 0 only */
268 	struct svc_xprt		*cb_xprt;	/* minorversion 1 only */
269 };
270 
271 static inline struct nfs4_delegation *delegstateid(struct nfs4_stid *s)
272 {
273 	return container_of(s, struct nfs4_delegation, dl_stid);
274 }
275 
276 /* Maximum number of slots per session.  This is for sanity-check only.
277  * It could be increased if we had a mechanism to shutdown misbehaving clients.
278  * A large number can be needed to get good throughput on high-latency servers.
279  */
280 #define NFSD_MAX_SLOTS_PER_SESSION	2048
281 /* Maximum  session per slot cache size */
282 #define NFSD_SLOT_CACHE_SIZE		2048
283 /* Maximum number of NFSD_SLOT_CACHE_SIZE slots per session */
284 #define NFSD_CACHE_SIZE_SLOTS_PER_SESSION	32
285 #define NFSD_MAX_MEM_PER_SESSION  \
286 		(NFSD_CACHE_SIZE_SLOTS_PER_SESSION * NFSD_SLOT_CACHE_SIZE)
287 
288 struct nfsd4_slot {
289 	u32	sl_seqid;
290 	__be32	sl_status;
291 	struct svc_cred sl_cred;
292 	u32	sl_index;
293 	u32	sl_datalen;
294 	u16	sl_opcnt;
295 	u16	sl_generation;
296 #define NFSD4_SLOT_INUSE	(1 << 0)
297 #define NFSD4_SLOT_CACHETHIS	(1 << 1)
298 #define NFSD4_SLOT_INITIALIZED	(1 << 2)
299 #define NFSD4_SLOT_CACHED	(1 << 3)
300 #define NFSD4_SLOT_REUSED	(1 << 4)
301 	u8	sl_flags;
302 	char	sl_data[];
303 };
304 
305 struct nfsd4_channel_attrs {
306 	u32		headerpadsz;
307 	u32		maxreq_sz;
308 	u32		maxresp_sz;
309 	u32		maxresp_cached;
310 	u32		maxops;
311 	u32		maxreqs;
312 	u32		nr_rdma_attrs;
313 	u32		rdma_attrs;
314 };
315 
316 struct nfsd4_cb_sec {
317 	u32	flavor; /* (u32)(-1) used to mean "no valid flavor" */
318 	kuid_t	uid;
319 	kgid_t	gid;
320 };
321 
322 struct nfsd4_create_session {
323 	clientid_t			clientid;
324 	struct nfs4_sessionid		sessionid;
325 	u32				seqid;
326 	u32				flags;
327 	struct nfsd4_channel_attrs	fore_channel;
328 	struct nfsd4_channel_attrs	back_channel;
329 	u32				callback_prog;
330 	struct nfsd4_cb_sec		cb_sec;
331 };
332 
333 struct nfsd4_backchannel_ctl {
334 	u32	bc_cb_program;
335 	struct nfsd4_cb_sec		bc_cb_sec;
336 };
337 
338 struct nfsd4_bind_conn_to_session {
339 	struct nfs4_sessionid		sessionid;
340 	u32				dir;
341 };
342 
343 /* The single slot clientid cache structure */
344 struct nfsd4_clid_slot {
345 	u32				sl_seqid;
346 	__be32				sl_status;
347 	struct nfsd4_create_session	sl_cr_ses;
348 };
349 
350 struct nfsd4_conn {
351 	struct list_head cn_persession;
352 	struct svc_xprt *cn_xprt;
353 	struct svc_xpt_user cn_xpt_user;
354 	struct nfsd4_session *cn_session;
355 /* CDFC4_FORE, CDFC4_BACK: */
356 	unsigned char cn_flags;
357 };
358 
359 /* Maximum number of slots that nfsd will use in the backchannel */
360 #define NFSD_BC_SLOT_TABLE_SIZE		(sizeof(u32) * 8)
361 
362 /*
363  * Representation of a v4.1+ session. These are refcounted in a similar fashion
364  * to the nfs4_client. References are only taken when the server is actively
365  * working on the object (primarily during the processing of compounds).
366  */
367 struct nfsd4_session {
368 	atomic_t		se_ref;
369 	spinlock_t		se_lock;
370 	u32			se_cb_slot_avail; /* bitmap of available slots */
371 	u32			se_cb_highest_slot;	/* highest slot client wants */
372 	u32			se_cb_prog;
373 	struct list_head	se_hash;	/* hash by sessionid */
374 	struct list_head	se_perclnt;
375 	struct list_head	se_all_sessions;/* global list of sessions */
376 	struct nfs4_client	*se_client;
377 	struct nfs4_sessionid	se_sessionid;
378 	struct nfsd4_channel_attrs se_fchannel;
379 	struct nfsd4_cb_sec	se_cb_sec;
380 	struct list_head	se_conns;
381 	u32			se_cb_seq_nr[NFSD_BC_SLOT_TABLE_SIZE];
382 	struct xarray		se_slots;	/* forward channel slots */
383 	u16			se_slot_gen;
384 	bool			se_dead;
385 	u32			se_target_maxslots;
386 };
387 
388 /* formatted contents of nfs4_sessionid */
389 struct nfsd4_sessionid {
390 	clientid_t	clientid;
391 	u32		sequence;
392 	u32		reserved;
393 };
394 
395 /* Length of MD5 digest as hex, plus terminating '\0' */
396 #define HEXDIR_LEN	(2 * MD5_DIGEST_SIZE + 1)
397 
398 /*
399  *       State                Meaning                  Where set
400  * --------------------------------------------------------------------------
401  * | NFSD4_ACTIVE      | Confirmed, active    | Default                     |
402  * |------------------- ----------------------------------------------------|
403  * | NFSD4_COURTESY    | Courtesy state.      | nfs4_get_client_reaplist    |
404  * |                   | Lease/lock/share     |                             |
405  * |                   | reservation conflict |                             |
406  * |                   | can cause Courtesy   |                             |
407  * |                   | client to be expired |                             |
408  * |------------------------------------------------------------------------|
409  * | NFSD4_EXPIRABLE   | Courtesy client to be| nfs4_laundromat             |
410  * |                   | expired by Laundromat| try_to_expire_client        |
411  * |                   | due to conflict      |                             |
412  * |------------------------------------------------------------------------|
413  */
414 enum {
415 	NFSD4_ACTIVE = 0,
416 	NFSD4_COURTESY,
417 	NFSD4_EXPIRABLE,
418 };
419 
420 /*
421  * struct nfs4_client - one per client.  Clientids live here.
422  *
423  * The initial object created by an NFS client using SETCLIENTID (for NFSv4.0)
424  * or EXCHANGE_ID (for NFSv4.1+). These objects are refcounted and timestamped.
425  * Each nfsd_net_ns object contains a set of these and they are tracked via
426  * short and long form clientid. They are hashed and searched for under the
427  * per-nfsd_net client_lock spinlock.
428  *
429  * References to it are only held during the processing of compounds, and in
430  * certain other operations. In their "resting state" they have a refcount of
431  * 0. If they are not renewed within a lease period, they become eligible for
432  * destruction by the laundromat.
433  *
434  * These objects can also be destroyed if the client sends certain forms of
435  * SETCLIENTID or EXCHANGE_ID operations.
436  *
437  * Care is taken *not* to do this however when the objects have an elevated
438  * refcount.
439  *
440  * o Each nfs4_client is hashed by clientid
441  *
442  * o Each nfs4_clients is also hashed by name (the opaque quantity initially
443  *   sent by the client to identify itself).
444  *
445  * o cl_perclient list is used to ensure no dangling stateowner references
446  *   when we expire the nfs4_client
447  */
448 struct nfs4_client {
449 	struct list_head	cl_idhash; 	/* hash by cl_clientid.id */
450 	struct rb_node		cl_namenode;	/* link into by-name trees */
451 	struct list_head	*cl_ownerstr_hashtbl;
452 	struct list_head	cl_openowners;
453 	struct idr		cl_stateids;	/* stateid lookup */
454 	struct list_head	cl_delegations;
455 	struct list_head	cl_revoked;	/* unacknowledged, revoked 4.1 state */
456 	struct list_head        cl_lru;         /* tail queue */
457 #ifdef CONFIG_NFSD_PNFS
458 	struct list_head	cl_lo_states;	/* outstanding layout states */
459 	bool			cl_fence_retry_warn;
460 #endif
461 	struct xdr_netobj	cl_name; 	/* id generated by client */
462 	nfs4_verifier		cl_verifier; 	/* generated by client */
463 	time64_t		cl_time;	/* time of last lease renewal */
464 	struct sockaddr_storage	cl_addr; 	/* client ipaddress */
465 	bool			cl_mach_cred;	/* SP4_MACH_CRED in force */
466 	struct svc_cred		cl_cred; 	/* setclientid principal */
467 	clientid_t		cl_clientid;	/* generated by server */
468 	nfs4_verifier		cl_confirm;	/* generated by server */
469 	u32			cl_minorversion;
470 	atomic_t		cl_admin_revoked; /* count of admin-revoked states */
471 	/* NFSv4.1 client implementation id: */
472 	struct xdr_netobj	cl_nii_domain;
473 	struct xdr_netobj	cl_nii_name;
474 	struct timespec64	cl_nii_time;
475 
476 	/* for v4.0 and v4.1 callbacks: */
477 	struct nfs4_cb_conn	cl_cb_conn;
478 #define NFSD4_CLIENT_CB_UPDATE		(0)
479 #define NFSD4_CLIENT_CB_KILL		(1)
480 #define NFSD4_CLIENT_STABLE		(2)	/* client on stable storage */
481 #define NFSD4_CLIENT_RECLAIM_COMPLETE	(3)	/* reclaim_complete done */
482 #define NFSD4_CLIENT_CONFIRMED		(4)	/* client is confirmed */
483 #define NFSD4_CLIENT_UPCALL_LOCK	(5)	/* upcall serialization */
484 #define NFSD4_CLIENT_CB_FLAG_MASK	(1 << NFSD4_CLIENT_CB_UPDATE | \
485 					 1 << NFSD4_CLIENT_CB_KILL)
486 	unsigned long		cl_flags;
487 
488 	struct workqueue_struct *cl_callback_wq;
489 	const struct cred	*cl_cb_cred;
490 	struct rpc_clnt		*cl_cb_client;
491 	u32			cl_cb_ident;
492 #define NFSD4_CB_UP		0
493 #define NFSD4_CB_UNKNOWN	1
494 #define NFSD4_CB_DOWN		2
495 #define NFSD4_CB_FAULT		3
496 	int			cl_cb_state;
497 	struct nfsd4_callback	cl_cb_null;
498 	struct nfsd4_session	*cl_cb_session;
499 
500 	/* for all client information that callback code might need: */
501 	spinlock_t		cl_lock;
502 
503 	/* for nfs41 */
504 	struct list_head	cl_sessions;
505 	struct nfsd4_clid_slot	cl_cs_slot;	/* create_session slot */
506 	u32			cl_exchange_flags;
507 	/* number of rpc's in progress over an associated session: */
508 	atomic_t		cl_rpc_users;
509 	struct nfsdfs_client	cl_nfsdfs;
510 	struct nfs4_op_map      cl_spo_must_allow;
511 
512 	/* debugging info directory under nfsd/clients/ : */
513 	struct dentry		*cl_nfsd_dentry;
514 	/* 'info' file within that directory. Ref is not counted,
515 	 * but will remain valid iff cl_nfsd_dentry != NULL
516 	 */
517 	struct dentry		*cl_nfsd_info_dentry;
518 
519 	struct rpc_wait_queue	cl_cb_waitq;	/* backchannel callers may */
520 						/* wait here for slots */
521 	struct net		*net;
522 	struct list_head	async_copies;	/* list of async copies */
523 	spinlock_t		async_lock;	/* lock for async copies */
524 	atomic_t		cl_cb_inflight;	/* Outstanding callbacks */
525 
526 	unsigned int		cl_state;
527 	atomic_t		cl_delegs_in_recall;
528 
529 	struct nfsd4_cb_recall_any	*cl_ra;
530 	time64_t		cl_ra_time;
531 #ifdef CONFIG_NFSD_SCSILAYOUT
532 	struct xarray		cl_dev_fences;
533 	struct mutex		cl_fence_mutex;
534 #endif
535 };
536 
537 /* struct nfs4_client_reset
538  * one per old client. Populates reset_str_hashtbl. Filled from conf_id_hashtbl
539  * upon lease reset, or from upcall to state_daemon (to read in state
540  * from non-volitile storage) upon reboot.
541  */
542 struct nfs4_client_reclaim {
543 	struct list_head	cr_strhash;	/* hash by cr_name */
544 	struct nfs4_client	*cr_clp;	/* pointer to associated clp */
545 	struct xdr_netobj	cr_name;	/* recovery dir name */
546 	struct xdr_netobj	cr_princhash;
547 };
548 
549 /*
550  * REPLAY_ISIZE is sized for an OPEN response with delegation:
551  *   4(status) + 8(stateid) + 20(changeinfo) + 4(rflags) +
552  *   8(verifier) + 4(deleg. type) + 8(deleg. stateid) +
553  *   4(deleg. recall flag) + 20(deleg. space limit) +
554  *   ~32(deleg. ace) = 112 bytes
555  *
556  * Some responses can exceed this. A LOCK denial includes the conflicting
557  * lock owner, which can be up to 1024 bytes (NFS4_OPAQUE_LIMIT). When a
558  * response exceeds REPLAY_ISIZE, a buffer is dynamically allocated. If
559  * that allocation fails, only rp_status is saved. Enlarging this constant
560  * increases the size of every nfs4_stateowner.
561  */
562 
563 #define NFSD4_REPLAY_ISIZE       112
564 
565 /*
566  * Replay buffer, where the result of the last seqid-mutating operation
567  * is cached.
568  */
569 struct nfs4_replay {
570 	__be32			rp_status;
571 	unsigned int		rp_buflen;
572 	char			*rp_buf; /* rp_ibuf or kmalloc'd */
573 	struct knfsd_fh		rp_openfh;
574 	int			rp_locked;
575 	char			rp_ibuf[NFSD4_REPLAY_ISIZE];
576 };
577 
578 extern void nfs4_replay_free_cache(struct nfs4_replay *rp);
579 
580 struct nfs4_stateowner;
581 
582 struct nfs4_stateowner_operations {
583 	void (*so_unhash)(struct nfs4_stateowner *);
584 	void (*so_free)(struct nfs4_stateowner *);
585 };
586 
587 /*
588  * A core object that represents either an open or lock owner. The object and
589  * lock owner objects have one of these embedded within them. Refcounts and
590  * other fields common to both owner types are contained within these
591  * structures.
592  */
593 struct nfs4_stateowner {
594 	struct list_head			so_strhash;
595 	struct list_head			so_stateids;
596 	struct nfs4_client			*so_client;
597 	const struct nfs4_stateowner_operations	*so_ops;
598 	/* after increment in nfsd4_bump_seqid, represents the next
599 	 * sequence id expected from the client: */
600 	atomic_t				so_count;
601 	u32					so_seqid;
602 	struct xdr_netobj			so_owner; /* open owner name */
603 	struct nfs4_replay			so_replay;
604 	bool					so_is_open_owner;
605 };
606 
607 /*
608  * When a file is opened, the client provides an open state owner opaque string
609  * that indicates the "owner" of that open. These objects are refcounted.
610  * References to it are held by each open state associated with it. This object
611  * is a superset of the nfs4_stateowner struct.
612  */
613 struct nfs4_openowner {
614 	struct nfs4_stateowner	oo_owner; /* must be first field */
615 	struct list_head        oo_perclient;
616 	/*
617 	 * We keep around openowners a little while after last close,
618 	 * which saves clients from having to confirm, and allows us to
619 	 * handle close replays if they come soon enough.  The close_lru
620 	 * is a list of such openowners, to be reaped by the laundromat
621 	 * thread eventually if they remain unused:
622 	 */
623 	struct list_head	oo_close_lru;
624 	struct nfs4_ol_stateid *oo_last_closed_stid;
625 	time64_t		oo_time; /* time of placement on so_close_lru */
626 #define NFS4_OO_CONFIRMED   1
627 	unsigned char		oo_flags;
628 };
629 
630 /*
631  * Represents a generic "lockowner". Similar to an openowner. References to it
632  * are held by the lock stateids that are created on its behalf. This object is
633  * a superset of the nfs4_stateowner struct.
634  */
635 struct nfs4_lockowner {
636 	struct nfs4_stateowner	lo_owner;	/* must be first element */
637 	struct list_head	lo_blocked;	/* blocked file_locks */
638 };
639 
640 static inline struct nfs4_openowner * openowner(struct nfs4_stateowner *so)
641 {
642 	return container_of(so, struct nfs4_openowner, oo_owner);
643 }
644 
645 static inline struct nfs4_lockowner * lockowner(struct nfs4_stateowner *so)
646 {
647 	return container_of(so, struct nfs4_lockowner, lo_owner);
648 }
649 
650 /*
651  * Per-client state indicating no. of opens and outstanding delegations
652  * on a file from a particular client.'od' stands for 'open & delegation'
653  */
654 struct nfs4_clnt_odstate {
655 	struct nfs4_client	*co_client;
656 	struct nfs4_file	*co_file;
657 	struct list_head	co_perfile;
658 	refcount_t		co_odcount;
659 };
660 
661 /*
662  * nfs4_file: a file opened by some number of (open) nfs4_stateowners.
663  *
664  * These objects are global. nfsd keeps one instance of a nfs4_file per
665  * filehandle (though it may keep multiple file descriptors for each). Each
666  * inode can have multiple filehandles associated with it, so there is
667  * (potentially) a many to one relationship between this struct and struct
668  * inode.
669  */
670 struct nfs4_file {
671 	refcount_t		fi_ref;
672 	struct inode *		fi_inode;
673 	bool			fi_aliased;
674 	spinlock_t		fi_lock;
675 	struct rhlist_head	fi_rlist;
676 	struct list_head        fi_stateids;
677 	union {
678 		struct list_head	fi_delegations;
679 		struct rcu_head		fi_rcu;
680 	};
681 	struct list_head	fi_clnt_odstate;
682 	/* One each for O_RDONLY, O_WRONLY, O_RDWR: */
683 	struct nfsd_file	*fi_fds[3];
684 	/*
685 	 * Each open or lock stateid contributes 0-4 to the counts
686 	 * below depending on which bits are set in st_access_bitmap:
687 	 *     1 to fi_access[O_RDONLY] if NFS4_SHARE_ACCES_READ is set
688 	 *   + 1 to fi_access[O_WRONLY] if NFS4_SHARE_ACCESS_WRITE is set
689 	 *   + 1 to both of the above if NFS4_SHARE_ACCESS_BOTH is set.
690 	 */
691 	atomic_t		fi_access[2];
692 	u32			fi_share_deny;
693 	struct nfsd_file	*fi_deleg_file;
694 	struct nfsd_file	*fi_rdeleg_file;
695 	int			fi_delegees;
696 	struct knfsd_fh		fi_fhandle;
697 	bool			fi_had_conflict;
698 #ifdef CONFIG_NFSD_PNFS
699 	struct list_head	fi_lo_states;
700 	atomic_t		fi_lo_recalls;
701 #endif
702 };
703 
704 /*
705  * A generic struct representing either a open or lock stateid. The nfs4_client
706  * holds a reference to each of these objects, and they in turn hold a
707  * reference to their respective stateowners. The client's reference is
708  * released in response to a close or unlock (depending on whether it's an open
709  * or lock stateid) or when the client is being destroyed.
710  *
711  * In the case of v4.0 open stateids, these objects are preserved for a little
712  * while after close in order to handle CLOSE replays. Those are eventually
713  * reclaimed via a LRU scheme by the laundromat.
714  *
715  * This object is a superset of the nfs4_stid. "ol" stands for "Open or Lock".
716  * Better suggestions welcome.
717  */
718 struct nfs4_ol_stateid {
719 	struct nfs4_stid		st_stid;
720 	struct list_head		st_perfile;
721 	struct list_head		st_perstateowner;
722 	struct list_head		st_locks;
723 	struct nfs4_stateowner		*st_stateowner;
724 	struct nfs4_clnt_odstate	*st_clnt_odstate;
725 /*
726  * These bitmasks use 3 separate bits for READ, ALLOW, and BOTH; see the
727  * comment above bmap_to_share_mode() for explanation:
728  */
729 	unsigned char			st_access_bmap;
730 	unsigned char			st_deny_bmap;
731 	struct nfs4_ol_stateid		*st_openstp;
732 	struct mutex			st_mutex;
733 };
734 
735 static inline struct nfs4_ol_stateid *openlockstateid(struct nfs4_stid *s)
736 {
737 	return container_of(s, struct nfs4_ol_stateid, st_stid);
738 }
739 
740 struct nfs4_layout_stateid {
741 	struct nfs4_stid		ls_stid;
742 	struct list_head		ls_perclnt;
743 	struct list_head		ls_perfile;
744 	spinlock_t			ls_lock;
745 	struct list_head		ls_layouts;
746 	u32				ls_layout_type;
747 	struct nfsd_file		*ls_file;
748 	struct nfsd4_callback		ls_recall;
749 	stateid_t			ls_recall_sid;
750 	bool				ls_recalled;
751 	struct mutex			ls_mutex;
752 
753 	struct delayed_work		ls_fence_work;
754 	unsigned int			ls_fence_delay;
755 	bool				ls_fenced;
756 };
757 
758 static inline struct nfs4_layout_stateid *layoutstateid(struct nfs4_stid *s)
759 {
760 	return container_of(s, struct nfs4_layout_stateid, ls_stid);
761 }
762 
763 /* flags for preprocess_seqid_op() */
764 #define RD_STATE	        0x00000010
765 #define WR_STATE	        0x00000020
766 
767 enum nfsd4_cb_op {
768 	NFSPROC4_CLNT_CB_NULL = 0,
769 	NFSPROC4_CLNT_CB_RECALL,
770 	NFSPROC4_CLNT_CB_LAYOUT,
771 	NFSPROC4_CLNT_CB_OFFLOAD,
772 	NFSPROC4_CLNT_CB_SEQUENCE,
773 	NFSPROC4_CLNT_CB_NOTIFY_LOCK,
774 	NFSPROC4_CLNT_CB_RECALL_ANY,
775 	NFSPROC4_CLNT_CB_GETATTR,
776 };
777 
778 /* Returns true iff a is later than b: */
779 static inline bool nfsd4_stateid_generation_after(stateid_t *a, stateid_t *b)
780 {
781 	return (s32)(a->si_generation - b->si_generation) > 0;
782 }
783 
784 /*
785  * When a client tries to get a lock on a file, we set one of these objects
786  * on the blocking lock. When the lock becomes free, we can then issue a
787  * CB_NOTIFY_LOCK to the server.
788  */
789 struct nfsd4_blocked_lock {
790 	struct list_head	nbl_list;
791 	struct list_head	nbl_lru;
792 	time64_t		nbl_time;
793 	struct file_lock	nbl_lock;
794 	struct knfsd_fh		nbl_fh;
795 	struct nfsd4_callback	nbl_cb;
796 	struct kref		nbl_kref;
797 };
798 
799 struct nfsd4_compound_state;
800 struct nfsd_net;
801 struct nfsd4_copy;
802 
803 extern __be32 nfs4_preprocess_stateid_op(struct svc_rqst *rqstp,
804 		struct nfsd4_compound_state *cstate, struct svc_fh *fhp,
805 		stateid_t *stateid, int flags, struct nfsd_file **filp,
806 		struct nfs4_stid **cstid);
807 __be32 nfsd4_lookup_stateid(struct nfsd4_compound_state *cstate,
808 			    stateid_t *stateid, unsigned short typemask,
809 			    unsigned short statusmask,
810 			    struct nfs4_stid **s, struct nfsd_net *nn);
811 struct nfs4_stid *nfs4_alloc_stid(struct nfs4_client *cl, struct kmem_cache *slab,
812 				  void (*sc_free)(struct nfs4_stid *));
813 int nfs4_init_copy_state(struct nfsd_net *nn, struct nfsd4_copy *copy);
814 void nfs4_free_copy_state(struct nfsd4_copy *copy);
815 struct nfs4_cpntf_state *nfs4_alloc_init_cpntf_state(struct nfsd_net *nn,
816 			struct nfs4_stid *p_stid);
817 void nfs4_put_stid(struct nfs4_stid *s);
818 void nfs4_inc_and_copy_stateid(stateid_t *dst, struct nfs4_stid *stid);
819 void nfs4_remove_reclaim_record(struct nfs4_client_reclaim *, struct nfsd_net *);
820 extern void nfs4_release_reclaim(struct nfsd_net *);
821 extern struct nfs4_client_reclaim *nfsd4_find_reclaim_client(struct xdr_netobj name,
822 							struct nfsd_net *nn);
823 extern __be32 nfs4_check_open_reclaim(struct nfs4_client *);
824 extern void nfsd4_probe_callback(struct nfs4_client *clp);
825 extern void nfsd4_probe_callback_sync(struct nfs4_client *clp);
826 extern void nfsd4_change_callback(struct nfs4_client *clp, struct nfs4_cb_conn *);
827 extern void nfsd41_cb_referring_call(struct nfsd4_callback *cb,
828 				     struct nfs4_sessionid *sessionid,
829 				     u32 slotid, u32 seqno);
830 extern void nfsd41_cb_destroy_referring_call_list(struct nfsd4_callback *cb);
831 extern void nfsd4_init_cb(struct nfsd4_callback *cb, struct nfs4_client *clp,
832 		const struct nfsd4_callback_ops *ops, enum nfsd4_cb_op op);
833 extern bool nfsd4_run_cb(struct nfsd4_callback *cb);
834 
835 static inline void nfsd4_try_run_cb(struct nfsd4_callback *cb)
836 {
837 	if (!test_and_set_bit(NFSD4_CALLBACK_RUNNING, &cb->cb_flags))
838 		WARN_ON_ONCE(!nfsd4_run_cb(cb));
839 }
840 
841 extern void nfsd4_shutdown_callback(struct nfs4_client *);
842 extern void nfsd4_shutdown_copy(struct nfs4_client *clp);
843 void nfsd4_put_client(struct nfs4_client *clp);
844 void nfsd4_async_copy_reaper(struct nfsd_net *nn);
845 bool nfsd4_has_active_async_copies(struct nfs4_client *clp);
846 extern struct nfs4_client_reclaim *nfs4_client_to_reclaim(struct xdr_netobj name,
847 				struct xdr_netobj princhash, struct nfsd_net *nn);
848 extern bool nfs4_has_reclaimed_state(struct xdr_netobj name, struct nfsd_net *nn);
849 
850 void put_nfs4_file(struct nfs4_file *fi);
851 extern void nfs4_put_cpntf_state(struct nfsd_net *nn,
852 				 struct nfs4_cpntf_state *cps);
853 extern __be32 manage_cpntf_state(struct nfsd_net *nn, stateid_t *st,
854 				 struct nfs4_client *clp,
855 				 struct nfs4_cpntf_state **cps);
856 static inline void get_nfs4_file(struct nfs4_file *fi)
857 {
858 	refcount_inc(&fi->fi_ref);
859 }
860 struct nfsd_file *find_any_file(struct nfs4_file *f);
861 
862 #ifdef CONFIG_NFSD_V4
863 void nfsd4_revoke_states(struct nfsd_net *nn, struct super_block *sb);
864 void nfsd4_cancel_copy_by_sb(struct net *net, struct super_block *sb);
865 int nfsd_net_cb_init(struct nfsd_net *nn);
866 void nfsd_net_cb_shutdown(struct nfsd_net *nn);
867 #else
868 static inline void nfsd4_revoke_states(struct nfsd_net *nn, struct super_block *sb)
869 {
870 }
871 static inline void nfsd4_cancel_copy_by_sb(struct net *net, struct super_block *sb)
872 {
873 }
874 static inline int nfsd_net_cb_init(struct nfsd_net *nn)
875 {
876 	return 0;
877 }
878 static inline void nfsd_net_cb_shutdown(struct nfsd_net *nn)
879 {
880 }
881 #endif
882 
883 /* grace period management */
884 bool nfsd4_force_end_grace(struct nfsd_net *nn);
885 
886 /* nfs4recover operations */
887 extern int nfsd4_client_tracking_init(struct net *net);
888 extern void nfsd4_client_tracking_exit(struct net *net);
889 extern void nfsd4_client_record_create(struct nfs4_client *clp);
890 extern void nfsd4_client_record_remove(struct nfs4_client *clp);
891 extern int nfsd4_client_record_check(struct nfs4_client *clp);
892 extern void nfsd4_record_grace_done(struct nfsd_net *nn);
893 
894 static inline bool try_to_expire_client(struct nfs4_client *clp)
895 {
896 	cmpxchg(&clp->cl_state, NFSD4_COURTESY, NFSD4_EXPIRABLE);
897 	return clp->cl_state == NFSD4_EXPIRABLE;
898 }
899 
900 extern __be32 nfsd4_deleg_getattr_conflict(struct svc_rqst *rqstp,
901 		struct dentry *dentry, struct nfs4_delegation **pdp);
902 
903 struct nfsd4_get_dir_delegation;
904 struct nfs4_delegation *nfsd_get_dir_deleg(struct nfsd4_compound_state *cstate,
905 						struct nfsd4_get_dir_delegation *gdd,
906 						struct nfsd_file *nf);
907 #endif   /* NFSD4_STATE_H */
908