xref: /openbmc/linux/fs/nfsd/nfs4state.c (revision 4bdf0bb7)
1 /*
2 *  linux/fs/nfsd/nfs4state.c
3 *
4 *  Copyright (c) 2001 The Regents of the University of Michigan.
5 *  All rights reserved.
6 *
7 *  Kendrick Smith <kmsmith@umich.edu>
8 *  Andy Adamson <kandros@umich.edu>
9 *
10 *  Redistribution and use in source and binary forms, with or without
11 *  modification, are permitted provided that the following conditions
12 *  are met:
13 *
14 *  1. Redistributions of source code must retain the above copyright
15 *     notice, this list of conditions and the following disclaimer.
16 *  2. Redistributions in binary form must reproduce the above copyright
17 *     notice, this list of conditions and the following disclaimer in the
18 *     documentation and/or other materials provided with the distribution.
19 *  3. Neither the name of the University nor the names of its
20 *     contributors may be used to endorse or promote products derived
21 *     from this software without specific prior written permission.
22 *
23 *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
24 *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
25 *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
26 *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27 *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
28 *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29 *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
30 *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31 *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32 *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33 *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 *
35 */
36 
37 #include <linux/param.h>
38 #include <linux/major.h>
39 #include <linux/slab.h>
40 
41 #include <linux/sunrpc/svc.h>
42 #include <linux/nfsd/nfsd.h>
43 #include <linux/nfsd/cache.h>
44 #include <linux/file.h>
45 #include <linux/mount.h>
46 #include <linux/workqueue.h>
47 #include <linux/smp_lock.h>
48 #include <linux/kthread.h>
49 #include <linux/nfs4.h>
50 #include <linux/nfsd/state.h>
51 #include <linux/nfsd/xdr4.h>
52 #include <linux/namei.h>
53 #include <linux/swap.h>
54 #include <linux/mutex.h>
55 #include <linux/lockd/bind.h>
56 #include <linux/module.h>
57 #include <linux/sunrpc/svcauth_gss.h>
58 #include <linux/sunrpc/clnt.h>
59 
60 #define NFSDDBG_FACILITY                NFSDDBG_PROC
61 
62 /* Globals */
63 static time_t lease_time = 90;     /* default lease time */
64 static time_t user_lease_time = 90;
65 static time_t boot_time;
66 static u32 current_ownerid = 1;
67 static u32 current_fileid = 1;
68 static u32 current_delegid = 1;
69 static u32 nfs4_init;
70 static stateid_t zerostateid;             /* bits all 0 */
71 static stateid_t onestateid;              /* bits all 1 */
72 static u64 current_sessionid = 1;
73 
74 #define ZERO_STATEID(stateid) (!memcmp((stateid), &zerostateid, sizeof(stateid_t)))
75 #define ONE_STATEID(stateid)  (!memcmp((stateid), &onestateid, sizeof(stateid_t)))
76 
77 /* forward declarations */
78 static struct nfs4_stateid * find_stateid(stateid_t *stid, int flags);
79 static struct nfs4_delegation * find_delegation_stateid(struct inode *ino, stateid_t *stid);
80 static char user_recovery_dirname[PATH_MAX] = "/var/lib/nfs/v4recovery";
81 static void nfs4_set_recdir(char *recdir);
82 
83 /* Locking: */
84 
85 /* Currently used for almost all code touching nfsv4 state: */
86 static DEFINE_MUTEX(client_mutex);
87 
88 /*
89  * Currently used for the del_recall_lru and file hash table.  In an
90  * effort to decrease the scope of the client_mutex, this spinlock may
91  * eventually cover more:
92  */
93 static DEFINE_SPINLOCK(recall_lock);
94 
95 static struct kmem_cache *stateowner_slab = NULL;
96 static struct kmem_cache *file_slab = NULL;
97 static struct kmem_cache *stateid_slab = NULL;
98 static struct kmem_cache *deleg_slab = NULL;
99 
100 void
101 nfs4_lock_state(void)
102 {
103 	mutex_lock(&client_mutex);
104 }
105 
106 void
107 nfs4_unlock_state(void)
108 {
109 	mutex_unlock(&client_mutex);
110 }
111 
112 static inline u32
113 opaque_hashval(const void *ptr, int nbytes)
114 {
115 	unsigned char *cptr = (unsigned char *) ptr;
116 
117 	u32 x = 0;
118 	while (nbytes--) {
119 		x *= 37;
120 		x += *cptr++;
121 	}
122 	return x;
123 }
124 
125 static struct list_head del_recall_lru;
126 
127 static inline void
128 put_nfs4_file(struct nfs4_file *fi)
129 {
130 	if (atomic_dec_and_lock(&fi->fi_ref, &recall_lock)) {
131 		list_del(&fi->fi_hash);
132 		spin_unlock(&recall_lock);
133 		iput(fi->fi_inode);
134 		kmem_cache_free(file_slab, fi);
135 	}
136 }
137 
138 static inline void
139 get_nfs4_file(struct nfs4_file *fi)
140 {
141 	atomic_inc(&fi->fi_ref);
142 }
143 
144 static int num_delegations;
145 unsigned int max_delegations;
146 
147 /*
148  * Open owner state (share locks)
149  */
150 
151 /* hash tables for nfs4_stateowner */
152 #define OWNER_HASH_BITS              8
153 #define OWNER_HASH_SIZE             (1 << OWNER_HASH_BITS)
154 #define OWNER_HASH_MASK             (OWNER_HASH_SIZE - 1)
155 
156 #define ownerid_hashval(id) \
157         ((id) & OWNER_HASH_MASK)
158 #define ownerstr_hashval(clientid, ownername) \
159         (((clientid) + opaque_hashval((ownername.data), (ownername.len))) & OWNER_HASH_MASK)
160 
161 static struct list_head	ownerid_hashtbl[OWNER_HASH_SIZE];
162 static struct list_head	ownerstr_hashtbl[OWNER_HASH_SIZE];
163 
164 /* hash table for nfs4_file */
165 #define FILE_HASH_BITS                   8
166 #define FILE_HASH_SIZE                  (1 << FILE_HASH_BITS)
167 #define FILE_HASH_MASK                  (FILE_HASH_SIZE - 1)
168 /* hash table for (open)nfs4_stateid */
169 #define STATEID_HASH_BITS              10
170 #define STATEID_HASH_SIZE              (1 << STATEID_HASH_BITS)
171 #define STATEID_HASH_MASK              (STATEID_HASH_SIZE - 1)
172 
173 #define file_hashval(x) \
174         hash_ptr(x, FILE_HASH_BITS)
175 #define stateid_hashval(owner_id, file_id)  \
176         (((owner_id) + (file_id)) & STATEID_HASH_MASK)
177 
178 static struct list_head file_hashtbl[FILE_HASH_SIZE];
179 static struct list_head stateid_hashtbl[STATEID_HASH_SIZE];
180 
181 static struct nfs4_delegation *
182 alloc_init_deleg(struct nfs4_client *clp, struct nfs4_stateid *stp, struct svc_fh *current_fh, u32 type)
183 {
184 	struct nfs4_delegation *dp;
185 	struct nfs4_file *fp = stp->st_file;
186 	struct nfs4_cb_conn *cb = &stp->st_stateowner->so_client->cl_cb_conn;
187 
188 	dprintk("NFSD alloc_init_deleg\n");
189 	if (fp->fi_had_conflict)
190 		return NULL;
191 	if (num_delegations > max_delegations)
192 		return NULL;
193 	dp = kmem_cache_alloc(deleg_slab, GFP_KERNEL);
194 	if (dp == NULL)
195 		return dp;
196 	num_delegations++;
197 	INIT_LIST_HEAD(&dp->dl_perfile);
198 	INIT_LIST_HEAD(&dp->dl_perclnt);
199 	INIT_LIST_HEAD(&dp->dl_recall_lru);
200 	dp->dl_client = clp;
201 	get_nfs4_file(fp);
202 	dp->dl_file = fp;
203 	dp->dl_flock = NULL;
204 	get_file(stp->st_vfs_file);
205 	dp->dl_vfs_file = stp->st_vfs_file;
206 	dp->dl_type = type;
207 	dp->dl_ident = cb->cb_ident;
208 	dp->dl_stateid.si_boot = get_seconds();
209 	dp->dl_stateid.si_stateownerid = current_delegid++;
210 	dp->dl_stateid.si_fileid = 0;
211 	dp->dl_stateid.si_generation = 0;
212 	fh_copy_shallow(&dp->dl_fh, &current_fh->fh_handle);
213 	dp->dl_time = 0;
214 	atomic_set(&dp->dl_count, 1);
215 	list_add(&dp->dl_perfile, &fp->fi_delegations);
216 	list_add(&dp->dl_perclnt, &clp->cl_delegations);
217 	return dp;
218 }
219 
220 void
221 nfs4_put_delegation(struct nfs4_delegation *dp)
222 {
223 	if (atomic_dec_and_test(&dp->dl_count)) {
224 		dprintk("NFSD: freeing dp %p\n",dp);
225 		put_nfs4_file(dp->dl_file);
226 		kmem_cache_free(deleg_slab, dp);
227 		num_delegations--;
228 	}
229 }
230 
231 /* Remove the associated file_lock first, then remove the delegation.
232  * lease_modify() is called to remove the FS_LEASE file_lock from
233  * the i_flock list, eventually calling nfsd's lock_manager
234  * fl_release_callback.
235  */
236 static void
237 nfs4_close_delegation(struct nfs4_delegation *dp)
238 {
239 	struct file *filp = dp->dl_vfs_file;
240 
241 	dprintk("NFSD: close_delegation dp %p\n",dp);
242 	dp->dl_vfs_file = NULL;
243 	/* The following nfsd_close may not actually close the file,
244 	 * but we want to remove the lease in any case. */
245 	if (dp->dl_flock)
246 		vfs_setlease(filp, F_UNLCK, &dp->dl_flock);
247 	nfsd_close(filp);
248 }
249 
250 /* Called under the state lock. */
251 static void
252 unhash_delegation(struct nfs4_delegation *dp)
253 {
254 	list_del_init(&dp->dl_perfile);
255 	list_del_init(&dp->dl_perclnt);
256 	spin_lock(&recall_lock);
257 	list_del_init(&dp->dl_recall_lru);
258 	spin_unlock(&recall_lock);
259 	nfs4_close_delegation(dp);
260 	nfs4_put_delegation(dp);
261 }
262 
263 /*
264  * SETCLIENTID state
265  */
266 
267 /* Hash tables for nfs4_clientid state */
268 #define CLIENT_HASH_BITS                 4
269 #define CLIENT_HASH_SIZE                (1 << CLIENT_HASH_BITS)
270 #define CLIENT_HASH_MASK                (CLIENT_HASH_SIZE - 1)
271 
272 #define clientid_hashval(id) \
273 	((id) & CLIENT_HASH_MASK)
274 #define clientstr_hashval(name) \
275 	(opaque_hashval((name), 8) & CLIENT_HASH_MASK)
276 /*
277  * reclaim_str_hashtbl[] holds known client info from previous reset/reboot
278  * used in reboot/reset lease grace period processing
279  *
280  * conf_id_hashtbl[], and conf_str_hashtbl[] hold confirmed
281  * setclientid_confirmed info.
282  *
283  * unconf_str_hastbl[] and unconf_id_hashtbl[] hold unconfirmed
284  * setclientid info.
285  *
286  * client_lru holds client queue ordered by nfs4_client.cl_time
287  * for lease renewal.
288  *
289  * close_lru holds (open) stateowner queue ordered by nfs4_stateowner.so_time
290  * for last close replay.
291  */
292 static struct list_head	reclaim_str_hashtbl[CLIENT_HASH_SIZE];
293 static int reclaim_str_hashtbl_size = 0;
294 static struct list_head	conf_id_hashtbl[CLIENT_HASH_SIZE];
295 static struct list_head	conf_str_hashtbl[CLIENT_HASH_SIZE];
296 static struct list_head	unconf_str_hashtbl[CLIENT_HASH_SIZE];
297 static struct list_head	unconf_id_hashtbl[CLIENT_HASH_SIZE];
298 static struct list_head client_lru;
299 static struct list_head close_lru;
300 
301 static void unhash_generic_stateid(struct nfs4_stateid *stp)
302 {
303 	list_del(&stp->st_hash);
304 	list_del(&stp->st_perfile);
305 	list_del(&stp->st_perstateowner);
306 }
307 
308 static void free_generic_stateid(struct nfs4_stateid *stp)
309 {
310 	put_nfs4_file(stp->st_file);
311 	kmem_cache_free(stateid_slab, stp);
312 }
313 
314 static void release_lock_stateid(struct nfs4_stateid *stp)
315 {
316 	unhash_generic_stateid(stp);
317 	locks_remove_posix(stp->st_vfs_file, (fl_owner_t)stp->st_stateowner);
318 	free_generic_stateid(stp);
319 }
320 
321 static void unhash_lockowner(struct nfs4_stateowner *sop)
322 {
323 	struct nfs4_stateid *stp;
324 
325 	list_del(&sop->so_idhash);
326 	list_del(&sop->so_strhash);
327 	list_del(&sop->so_perstateid);
328 	while (!list_empty(&sop->so_stateids)) {
329 		stp = list_first_entry(&sop->so_stateids,
330 				struct nfs4_stateid, st_perstateowner);
331 		release_lock_stateid(stp);
332 	}
333 }
334 
335 static void release_lockowner(struct nfs4_stateowner *sop)
336 {
337 	unhash_lockowner(sop);
338 	nfs4_put_stateowner(sop);
339 }
340 
341 static void
342 release_stateid_lockowners(struct nfs4_stateid *open_stp)
343 {
344 	struct nfs4_stateowner *lock_sop;
345 
346 	while (!list_empty(&open_stp->st_lockowners)) {
347 		lock_sop = list_entry(open_stp->st_lockowners.next,
348 				struct nfs4_stateowner, so_perstateid);
349 		/* list_del(&open_stp->st_lockowners);  */
350 		BUG_ON(lock_sop->so_is_open_owner);
351 		release_lockowner(lock_sop);
352 	}
353 }
354 
355 static void release_open_stateid(struct nfs4_stateid *stp)
356 {
357 	unhash_generic_stateid(stp);
358 	release_stateid_lockowners(stp);
359 	nfsd_close(stp->st_vfs_file);
360 	free_generic_stateid(stp);
361 }
362 
363 static void unhash_openowner(struct nfs4_stateowner *sop)
364 {
365 	struct nfs4_stateid *stp;
366 
367 	list_del(&sop->so_idhash);
368 	list_del(&sop->so_strhash);
369 	list_del(&sop->so_perclient);
370 	list_del(&sop->so_perstateid); /* XXX: necessary? */
371 	while (!list_empty(&sop->so_stateids)) {
372 		stp = list_first_entry(&sop->so_stateids,
373 				struct nfs4_stateid, st_perstateowner);
374 		release_open_stateid(stp);
375 	}
376 }
377 
378 static void release_openowner(struct nfs4_stateowner *sop)
379 {
380 	unhash_openowner(sop);
381 	list_del(&sop->so_close_lru);
382 	nfs4_put_stateowner(sop);
383 }
384 
385 static DEFINE_SPINLOCK(sessionid_lock);
386 #define SESSION_HASH_SIZE	512
387 static struct list_head sessionid_hashtbl[SESSION_HASH_SIZE];
388 
389 static inline int
390 hash_sessionid(struct nfs4_sessionid *sessionid)
391 {
392 	struct nfsd4_sessionid *sid = (struct nfsd4_sessionid *)sessionid;
393 
394 	return sid->sequence % SESSION_HASH_SIZE;
395 }
396 
397 static inline void
398 dump_sessionid(const char *fn, struct nfs4_sessionid *sessionid)
399 {
400 	u32 *ptr = (u32 *)(&sessionid->data[0]);
401 	dprintk("%s: %u:%u:%u:%u\n", fn, ptr[0], ptr[1], ptr[2], ptr[3]);
402 }
403 
404 static void
405 gen_sessionid(struct nfsd4_session *ses)
406 {
407 	struct nfs4_client *clp = ses->se_client;
408 	struct nfsd4_sessionid *sid;
409 
410 	sid = (struct nfsd4_sessionid *)ses->se_sessionid.data;
411 	sid->clientid = clp->cl_clientid;
412 	sid->sequence = current_sessionid++;
413 	sid->reserved = 0;
414 }
415 
416 /*
417  * The protocol defines ca_maxresponssize_cached to include the size of
418  * the rpc header, but all we need to cache is the data starting after
419  * the end of the initial SEQUENCE operation--the rest we regenerate
420  * each time.  Therefore we can advertise a ca_maxresponssize_cached
421  * value that is the number of bytes in our cache plus a few additional
422  * bytes.  In order to stay on the safe side, and not promise more than
423  * we can cache, those additional bytes must be the minimum possible: 24
424  * bytes of rpc header (xid through accept state, with AUTH_NULL
425  * verifier), 12 for the compound header (with zero-length tag), and 44
426  * for the SEQUENCE op response:
427  */
428 #define NFSD_MIN_HDR_SEQ_SZ  (24 + 12 + 44)
429 
430 /*
431  * Give the client the number of ca_maxresponsesize_cached slots it
432  * requests, of size bounded by NFSD_SLOT_CACHE_SIZE,
433  * NFSD_MAX_MEM_PER_SESSION, and nfsd_drc_max_mem. Do not allow more
434  * than NFSD_MAX_SLOTS_PER_SESSION.
435  *
436  * If we run out of reserved DRC memory we should (up to a point)
437  * re-negotiate active sessions and reduce their slot usage to make
438  * rooom for new connections. For now we just fail the create session.
439  */
440 static int set_forechannel_drc_size(struct nfsd4_channel_attrs *fchan)
441 {
442 	int mem, size = fchan->maxresp_cached;
443 
444 	if (fchan->maxreqs < 1)
445 		return nfserr_inval;
446 
447 	if (size < NFSD_MIN_HDR_SEQ_SZ)
448 		size = NFSD_MIN_HDR_SEQ_SZ;
449 	size -= NFSD_MIN_HDR_SEQ_SZ;
450 	if (size > NFSD_SLOT_CACHE_SIZE)
451 		size = NFSD_SLOT_CACHE_SIZE;
452 
453 	/* bound the maxreqs by NFSD_MAX_MEM_PER_SESSION */
454 	mem = fchan->maxreqs * size;
455 	if (mem > NFSD_MAX_MEM_PER_SESSION) {
456 		fchan->maxreqs = NFSD_MAX_MEM_PER_SESSION / size;
457 		if (fchan->maxreqs > NFSD_MAX_SLOTS_PER_SESSION)
458 			fchan->maxreqs = NFSD_MAX_SLOTS_PER_SESSION;
459 		mem = fchan->maxreqs * size;
460 	}
461 
462 	spin_lock(&nfsd_drc_lock);
463 	/* bound the total session drc memory ussage */
464 	if (mem + nfsd_drc_mem_used > nfsd_drc_max_mem) {
465 		fchan->maxreqs = (nfsd_drc_max_mem - nfsd_drc_mem_used) / size;
466 		mem = fchan->maxreqs * size;
467 	}
468 	nfsd_drc_mem_used += mem;
469 	spin_unlock(&nfsd_drc_lock);
470 
471 	if (fchan->maxreqs == 0)
472 		return nfserr_serverfault;
473 
474 	fchan->maxresp_cached = size + NFSD_MIN_HDR_SEQ_SZ;
475 	return 0;
476 }
477 
478 /*
479  * fchan holds the client values on input, and the server values on output
480  */
481 static int init_forechannel_attrs(struct svc_rqst *rqstp,
482 				  struct nfsd4_channel_attrs *session_fchan,
483 				  struct nfsd4_channel_attrs *fchan)
484 {
485 	int status = 0;
486 	__u32   maxcount = svc_max_payload(rqstp);
487 
488 	/* headerpadsz set to zero in encode routine */
489 
490 	/* Use the client's max request and max response size if possible */
491 	if (fchan->maxreq_sz > maxcount)
492 		fchan->maxreq_sz = maxcount;
493 	session_fchan->maxreq_sz = fchan->maxreq_sz;
494 
495 	if (fchan->maxresp_sz > maxcount)
496 		fchan->maxresp_sz = maxcount;
497 	session_fchan->maxresp_sz = fchan->maxresp_sz;
498 
499 	/* Use the client's maxops if possible */
500 	if (fchan->maxops > NFSD_MAX_OPS_PER_COMPOUND)
501 		fchan->maxops = NFSD_MAX_OPS_PER_COMPOUND;
502 	session_fchan->maxops = fchan->maxops;
503 
504 	/* FIXME: Error means no more DRC pages so the server should
505 	 * recover pages from existing sessions. For now fail session
506 	 * creation.
507 	 */
508 	status = set_forechannel_drc_size(fchan);
509 
510 	session_fchan->maxresp_cached = fchan->maxresp_cached;
511 	session_fchan->maxreqs = fchan->maxreqs;
512 
513 	dprintk("%s status %d\n", __func__, status);
514 	return status;
515 }
516 
517 static void
518 free_session_slots(struct nfsd4_session *ses)
519 {
520 	int i;
521 
522 	for (i = 0; i < ses->se_fchannel.maxreqs; i++)
523 		kfree(ses->se_slots[i]);
524 }
525 
526 static int
527 alloc_init_session(struct svc_rqst *rqstp, struct nfs4_client *clp,
528 		   struct nfsd4_create_session *cses)
529 {
530 	struct nfsd4_session *new, tmp;
531 	struct nfsd4_slot *sp;
532 	int idx, slotsize, cachesize, i;
533 	int status;
534 
535 	memset(&tmp, 0, sizeof(tmp));
536 
537 	/* FIXME: For now, we just accept the client back channel attributes. */
538 	tmp.se_bchannel = cses->back_channel;
539 	status = init_forechannel_attrs(rqstp, &tmp.se_fchannel,
540 					&cses->fore_channel);
541 	if (status)
542 		goto out;
543 
544 	BUILD_BUG_ON(NFSD_MAX_SLOTS_PER_SESSION * sizeof(struct nfsd4_slot)
545 		     + sizeof(struct nfsd4_session) > PAGE_SIZE);
546 
547 	status = nfserr_serverfault;
548 	/* allocate struct nfsd4_session and slot table pointers in one piece */
549 	slotsize = tmp.se_fchannel.maxreqs * sizeof(struct nfsd4_slot *);
550 	new = kzalloc(sizeof(*new) + slotsize, GFP_KERNEL);
551 	if (!new)
552 		goto out;
553 
554 	memcpy(new, &tmp, sizeof(*new));
555 
556 	/* allocate each struct nfsd4_slot and data cache in one piece */
557 	cachesize = new->se_fchannel.maxresp_cached - NFSD_MIN_HDR_SEQ_SZ;
558 	for (i = 0; i < new->se_fchannel.maxreqs; i++) {
559 		sp = kzalloc(sizeof(*sp) + cachesize, GFP_KERNEL);
560 		if (!sp)
561 			goto out_free;
562 		new->se_slots[i] = sp;
563 	}
564 
565 	new->se_client = clp;
566 	gen_sessionid(new);
567 	idx = hash_sessionid(&new->se_sessionid);
568 	memcpy(clp->cl_sessionid.data, new->se_sessionid.data,
569 	       NFS4_MAX_SESSIONID_LEN);
570 
571 	new->se_flags = cses->flags;
572 	kref_init(&new->se_ref);
573 	spin_lock(&sessionid_lock);
574 	list_add(&new->se_hash, &sessionid_hashtbl[idx]);
575 	list_add(&new->se_perclnt, &clp->cl_sessions);
576 	spin_unlock(&sessionid_lock);
577 
578 	status = nfs_ok;
579 out:
580 	return status;
581 out_free:
582 	free_session_slots(new);
583 	kfree(new);
584 	goto out;
585 }
586 
587 /* caller must hold sessionid_lock */
588 static struct nfsd4_session *
589 find_in_sessionid_hashtbl(struct nfs4_sessionid *sessionid)
590 {
591 	struct nfsd4_session *elem;
592 	int idx;
593 
594 	dump_sessionid(__func__, sessionid);
595 	idx = hash_sessionid(sessionid);
596 	dprintk("%s: idx is %d\n", __func__, idx);
597 	/* Search in the appropriate list */
598 	list_for_each_entry(elem, &sessionid_hashtbl[idx], se_hash) {
599 		dump_sessionid("list traversal", &elem->se_sessionid);
600 		if (!memcmp(elem->se_sessionid.data, sessionid->data,
601 			    NFS4_MAX_SESSIONID_LEN)) {
602 			return elem;
603 		}
604 	}
605 
606 	dprintk("%s: session not found\n", __func__);
607 	return NULL;
608 }
609 
610 /* caller must hold sessionid_lock */
611 static void
612 unhash_session(struct nfsd4_session *ses)
613 {
614 	list_del(&ses->se_hash);
615 	list_del(&ses->se_perclnt);
616 }
617 
618 static void
619 release_session(struct nfsd4_session *ses)
620 {
621 	spin_lock(&sessionid_lock);
622 	unhash_session(ses);
623 	spin_unlock(&sessionid_lock);
624 	nfsd4_put_session(ses);
625 }
626 
627 void
628 free_session(struct kref *kref)
629 {
630 	struct nfsd4_session *ses;
631 
632 	ses = container_of(kref, struct nfsd4_session, se_ref);
633 	spin_lock(&nfsd_drc_lock);
634 	nfsd_drc_mem_used -= ses->se_fchannel.maxreqs * NFSD_SLOT_CACHE_SIZE;
635 	spin_unlock(&nfsd_drc_lock);
636 	free_session_slots(ses);
637 	kfree(ses);
638 }
639 
640 static inline void
641 renew_client(struct nfs4_client *clp)
642 {
643 	/*
644 	* Move client to the end to the LRU list.
645 	*/
646 	dprintk("renewing client (clientid %08x/%08x)\n",
647 			clp->cl_clientid.cl_boot,
648 			clp->cl_clientid.cl_id);
649 	list_move_tail(&clp->cl_lru, &client_lru);
650 	clp->cl_time = get_seconds();
651 }
652 
653 /* SETCLIENTID and SETCLIENTID_CONFIRM Helper functions */
654 static int
655 STALE_CLIENTID(clientid_t *clid)
656 {
657 	if (clid->cl_boot == boot_time)
658 		return 0;
659 	dprintk("NFSD stale clientid (%08x/%08x) boot_time %08lx\n",
660 		clid->cl_boot, clid->cl_id, boot_time);
661 	return 1;
662 }
663 
664 /*
665  * XXX Should we use a slab cache ?
666  * This type of memory management is somewhat inefficient, but we use it
667  * anyway since SETCLIENTID is not a common operation.
668  */
669 static struct nfs4_client *alloc_client(struct xdr_netobj name)
670 {
671 	struct nfs4_client *clp;
672 
673 	clp = kzalloc(sizeof(struct nfs4_client), GFP_KERNEL);
674 	if (clp == NULL)
675 		return NULL;
676 	clp->cl_name.data = kmalloc(name.len, GFP_KERNEL);
677 	if (clp->cl_name.data == NULL) {
678 		kfree(clp);
679 		return NULL;
680 	}
681 	memcpy(clp->cl_name.data, name.data, name.len);
682 	clp->cl_name.len = name.len;
683 	return clp;
684 }
685 
686 static void
687 shutdown_callback_client(struct nfs4_client *clp)
688 {
689 	struct rpc_clnt *clnt = clp->cl_cb_conn.cb_client;
690 
691 	if (clnt) {
692 		/*
693 		 * Callback threads take a reference on the client, so there
694 		 * should be no outstanding callbacks at this point.
695 		 */
696 		clp->cl_cb_conn.cb_client = NULL;
697 		rpc_shutdown_client(clnt);
698 	}
699 }
700 
701 static inline void
702 free_client(struct nfs4_client *clp)
703 {
704 	shutdown_callback_client(clp);
705 	if (clp->cl_cb_xprt)
706 		svc_xprt_put(clp->cl_cb_xprt);
707 	if (clp->cl_cred.cr_group_info)
708 		put_group_info(clp->cl_cred.cr_group_info);
709 	kfree(clp->cl_principal);
710 	kfree(clp->cl_name.data);
711 	kfree(clp);
712 }
713 
714 void
715 put_nfs4_client(struct nfs4_client *clp)
716 {
717 	if (atomic_dec_and_test(&clp->cl_count))
718 		free_client(clp);
719 }
720 
721 static void
722 expire_client(struct nfs4_client *clp)
723 {
724 	struct nfs4_stateowner *sop;
725 	struct nfs4_delegation *dp;
726 	struct list_head reaplist;
727 
728 	dprintk("NFSD: expire_client cl_count %d\n",
729 	                    atomic_read(&clp->cl_count));
730 
731 	INIT_LIST_HEAD(&reaplist);
732 	spin_lock(&recall_lock);
733 	while (!list_empty(&clp->cl_delegations)) {
734 		dp = list_entry(clp->cl_delegations.next, struct nfs4_delegation, dl_perclnt);
735 		dprintk("NFSD: expire client. dp %p, fp %p\n", dp,
736 				dp->dl_flock);
737 		list_del_init(&dp->dl_perclnt);
738 		list_move(&dp->dl_recall_lru, &reaplist);
739 	}
740 	spin_unlock(&recall_lock);
741 	while (!list_empty(&reaplist)) {
742 		dp = list_entry(reaplist.next, struct nfs4_delegation, dl_recall_lru);
743 		list_del_init(&dp->dl_recall_lru);
744 		unhash_delegation(dp);
745 	}
746 	list_del(&clp->cl_idhash);
747 	list_del(&clp->cl_strhash);
748 	list_del(&clp->cl_lru);
749 	while (!list_empty(&clp->cl_openowners)) {
750 		sop = list_entry(clp->cl_openowners.next, struct nfs4_stateowner, so_perclient);
751 		release_openowner(sop);
752 	}
753 	while (!list_empty(&clp->cl_sessions)) {
754 		struct nfsd4_session  *ses;
755 		ses = list_entry(clp->cl_sessions.next, struct nfsd4_session,
756 				 se_perclnt);
757 		release_session(ses);
758 	}
759 	put_nfs4_client(clp);
760 }
761 
762 static void copy_verf(struct nfs4_client *target, nfs4_verifier *source)
763 {
764 	memcpy(target->cl_verifier.data, source->data,
765 			sizeof(target->cl_verifier.data));
766 }
767 
768 static void copy_clid(struct nfs4_client *target, struct nfs4_client *source)
769 {
770 	target->cl_clientid.cl_boot = source->cl_clientid.cl_boot;
771 	target->cl_clientid.cl_id = source->cl_clientid.cl_id;
772 }
773 
774 static void copy_cred(struct svc_cred *target, struct svc_cred *source)
775 {
776 	target->cr_uid = source->cr_uid;
777 	target->cr_gid = source->cr_gid;
778 	target->cr_group_info = source->cr_group_info;
779 	get_group_info(target->cr_group_info);
780 }
781 
782 static int same_name(const char *n1, const char *n2)
783 {
784 	return 0 == memcmp(n1, n2, HEXDIR_LEN);
785 }
786 
787 static int
788 same_verf(nfs4_verifier *v1, nfs4_verifier *v2)
789 {
790 	return 0 == memcmp(v1->data, v2->data, sizeof(v1->data));
791 }
792 
793 static int
794 same_clid(clientid_t *cl1, clientid_t *cl2)
795 {
796 	return (cl1->cl_boot == cl2->cl_boot) && (cl1->cl_id == cl2->cl_id);
797 }
798 
799 /* XXX what about NGROUP */
800 static int
801 same_creds(struct svc_cred *cr1, struct svc_cred *cr2)
802 {
803 	return cr1->cr_uid == cr2->cr_uid;
804 }
805 
806 static void gen_clid(struct nfs4_client *clp)
807 {
808 	static u32 current_clientid = 1;
809 
810 	clp->cl_clientid.cl_boot = boot_time;
811 	clp->cl_clientid.cl_id = current_clientid++;
812 }
813 
814 static void gen_confirm(struct nfs4_client *clp)
815 {
816 	static u32 i;
817 	u32 *p;
818 
819 	p = (u32 *)clp->cl_confirm.data;
820 	*p++ = get_seconds();
821 	*p++ = i++;
822 }
823 
824 static struct nfs4_client *create_client(struct xdr_netobj name, char *recdir,
825 		struct svc_rqst *rqstp, nfs4_verifier *verf)
826 {
827 	struct nfs4_client *clp;
828 	struct sockaddr *sa = svc_addr(rqstp);
829 	char *princ;
830 
831 	clp = alloc_client(name);
832 	if (clp == NULL)
833 		return NULL;
834 
835 	princ = svc_gss_principal(rqstp);
836 	if (princ) {
837 		clp->cl_principal = kstrdup(princ, GFP_KERNEL);
838 		if (clp->cl_principal == NULL) {
839 			free_client(clp);
840 			return NULL;
841 		}
842 	}
843 
844 	memcpy(clp->cl_recdir, recdir, HEXDIR_LEN);
845 	atomic_set(&clp->cl_count, 1);
846 	atomic_set(&clp->cl_cb_conn.cb_set, 0);
847 	INIT_LIST_HEAD(&clp->cl_idhash);
848 	INIT_LIST_HEAD(&clp->cl_strhash);
849 	INIT_LIST_HEAD(&clp->cl_openowners);
850 	INIT_LIST_HEAD(&clp->cl_delegations);
851 	INIT_LIST_HEAD(&clp->cl_sessions);
852 	INIT_LIST_HEAD(&clp->cl_lru);
853 	clear_bit(0, &clp->cl_cb_slot_busy);
854 	rpc_init_wait_queue(&clp->cl_cb_waitq, "Backchannel slot table");
855 	copy_verf(clp, verf);
856 	rpc_copy_addr((struct sockaddr *) &clp->cl_addr, sa);
857 	clp->cl_flavor = rqstp->rq_flavor;
858 	copy_cred(&clp->cl_cred, &rqstp->rq_cred);
859 	gen_confirm(clp);
860 
861 	return clp;
862 }
863 
864 static int check_name(struct xdr_netobj name)
865 {
866 	if (name.len == 0)
867 		return 0;
868 	if (name.len > NFS4_OPAQUE_LIMIT) {
869 		dprintk("NFSD: check_name: name too long(%d)!\n", name.len);
870 		return 0;
871 	}
872 	return 1;
873 }
874 
875 static void
876 add_to_unconfirmed(struct nfs4_client *clp, unsigned int strhashval)
877 {
878 	unsigned int idhashval;
879 
880 	list_add(&clp->cl_strhash, &unconf_str_hashtbl[strhashval]);
881 	idhashval = clientid_hashval(clp->cl_clientid.cl_id);
882 	list_add(&clp->cl_idhash, &unconf_id_hashtbl[idhashval]);
883 	list_add_tail(&clp->cl_lru, &client_lru);
884 	clp->cl_time = get_seconds();
885 }
886 
887 static void
888 move_to_confirmed(struct nfs4_client *clp)
889 {
890 	unsigned int idhashval = clientid_hashval(clp->cl_clientid.cl_id);
891 	unsigned int strhashval;
892 
893 	dprintk("NFSD: move_to_confirm nfs4_client %p\n", clp);
894 	list_del_init(&clp->cl_strhash);
895 	list_move(&clp->cl_idhash, &conf_id_hashtbl[idhashval]);
896 	strhashval = clientstr_hashval(clp->cl_recdir);
897 	list_add(&clp->cl_strhash, &conf_str_hashtbl[strhashval]);
898 	renew_client(clp);
899 }
900 
901 static struct nfs4_client *
902 find_confirmed_client(clientid_t *clid)
903 {
904 	struct nfs4_client *clp;
905 	unsigned int idhashval = clientid_hashval(clid->cl_id);
906 
907 	list_for_each_entry(clp, &conf_id_hashtbl[idhashval], cl_idhash) {
908 		if (same_clid(&clp->cl_clientid, clid))
909 			return clp;
910 	}
911 	return NULL;
912 }
913 
914 static struct nfs4_client *
915 find_unconfirmed_client(clientid_t *clid)
916 {
917 	struct nfs4_client *clp;
918 	unsigned int idhashval = clientid_hashval(clid->cl_id);
919 
920 	list_for_each_entry(clp, &unconf_id_hashtbl[idhashval], cl_idhash) {
921 		if (same_clid(&clp->cl_clientid, clid))
922 			return clp;
923 	}
924 	return NULL;
925 }
926 
927 /*
928  * Return 1 iff clp's clientid establishment method matches the use_exchange_id
929  * parameter. Matching is based on the fact the at least one of the
930  * EXCHGID4_FLAG_USE_{NON_PNFS,PNFS_MDS,PNFS_DS} flags must be set for v4.1
931  *
932  * FIXME: we need to unify the clientid namespaces for nfsv4.x
933  * and correctly deal with client upgrade/downgrade in EXCHANGE_ID
934  * and SET_CLIENTID{,_CONFIRM}
935  */
936 static inline int
937 match_clientid_establishment(struct nfs4_client *clp, bool use_exchange_id)
938 {
939 	bool has_exchange_flags = (clp->cl_exchange_flags != 0);
940 	return use_exchange_id == has_exchange_flags;
941 }
942 
943 static struct nfs4_client *
944 find_confirmed_client_by_str(const char *dname, unsigned int hashval,
945 			     bool use_exchange_id)
946 {
947 	struct nfs4_client *clp;
948 
949 	list_for_each_entry(clp, &conf_str_hashtbl[hashval], cl_strhash) {
950 		if (same_name(clp->cl_recdir, dname) &&
951 		    match_clientid_establishment(clp, use_exchange_id))
952 			return clp;
953 	}
954 	return NULL;
955 }
956 
957 static struct nfs4_client *
958 find_unconfirmed_client_by_str(const char *dname, unsigned int hashval,
959 			       bool use_exchange_id)
960 {
961 	struct nfs4_client *clp;
962 
963 	list_for_each_entry(clp, &unconf_str_hashtbl[hashval], cl_strhash) {
964 		if (same_name(clp->cl_recdir, dname) &&
965 		    match_clientid_establishment(clp, use_exchange_id))
966 			return clp;
967 	}
968 	return NULL;
969 }
970 
971 static void
972 gen_callback(struct nfs4_client *clp, struct nfsd4_setclientid *se, u32 scopeid)
973 {
974 	struct nfs4_cb_conn *cb = &clp->cl_cb_conn;
975 	unsigned short expected_family;
976 
977 	/* Currently, we only support tcp and tcp6 for the callback channel */
978 	if (se->se_callback_netid_len == 3 &&
979 	    !memcmp(se->se_callback_netid_val, "tcp", 3))
980 		expected_family = AF_INET;
981 	else if (se->se_callback_netid_len == 4 &&
982 		 !memcmp(se->se_callback_netid_val, "tcp6", 4))
983 		expected_family = AF_INET6;
984 	else
985 		goto out_err;
986 
987 	cb->cb_addrlen = rpc_uaddr2sockaddr(se->se_callback_addr_val,
988 					    se->se_callback_addr_len,
989 					    (struct sockaddr *) &cb->cb_addr,
990 					    sizeof(cb->cb_addr));
991 
992 	if (!cb->cb_addrlen || cb->cb_addr.ss_family != expected_family)
993 		goto out_err;
994 
995 	if (cb->cb_addr.ss_family == AF_INET6)
996 		((struct sockaddr_in6 *) &cb->cb_addr)->sin6_scope_id = scopeid;
997 
998 	cb->cb_minorversion = 0;
999 	cb->cb_prog = se->se_callback_prog;
1000 	cb->cb_ident = se->se_callback_ident;
1001 	return;
1002 out_err:
1003 	cb->cb_addr.ss_family = AF_UNSPEC;
1004 	cb->cb_addrlen = 0;
1005 	dprintk(KERN_INFO "NFSD: this client (clientid %08x/%08x) "
1006 		"will not receive delegations\n",
1007 		clp->cl_clientid.cl_boot, clp->cl_clientid.cl_id);
1008 
1009 	return;
1010 }
1011 
1012 /*
1013  * Cache a reply. nfsd4_check_drc_limit() has bounded the cache size.
1014  */
1015 void
1016 nfsd4_store_cache_entry(struct nfsd4_compoundres *resp)
1017 {
1018 	struct nfsd4_slot *slot = resp->cstate.slot;
1019 	unsigned int base;
1020 
1021 	dprintk("--> %s slot %p\n", __func__, slot);
1022 
1023 	slot->sl_opcnt = resp->opcnt;
1024 	slot->sl_status = resp->cstate.status;
1025 
1026 	if (nfsd4_not_cached(resp)) {
1027 		slot->sl_datalen = 0;
1028 		return;
1029 	}
1030 	slot->sl_datalen = (char *)resp->p - (char *)resp->cstate.datap;
1031 	base = (char *)resp->cstate.datap -
1032 					(char *)resp->xbuf->head[0].iov_base;
1033 	if (read_bytes_from_xdr_buf(resp->xbuf, base, slot->sl_data,
1034 				    slot->sl_datalen))
1035 		WARN("%s: sessions DRC could not cache compound\n", __func__);
1036 	return;
1037 }
1038 
1039 /*
1040  * Encode the replay sequence operation from the slot values.
1041  * If cachethis is FALSE encode the uncached rep error on the next
1042  * operation which sets resp->p and increments resp->opcnt for
1043  * nfs4svc_encode_compoundres.
1044  *
1045  */
1046 static __be32
1047 nfsd4_enc_sequence_replay(struct nfsd4_compoundargs *args,
1048 			  struct nfsd4_compoundres *resp)
1049 {
1050 	struct nfsd4_op *op;
1051 	struct nfsd4_slot *slot = resp->cstate.slot;
1052 
1053 	dprintk("--> %s resp->opcnt %d cachethis %u \n", __func__,
1054 		resp->opcnt, resp->cstate.slot->sl_cachethis);
1055 
1056 	/* Encode the replayed sequence operation */
1057 	op = &args->ops[resp->opcnt - 1];
1058 	nfsd4_encode_operation(resp, op);
1059 
1060 	/* Return nfserr_retry_uncached_rep in next operation. */
1061 	if (args->opcnt > 1 && slot->sl_cachethis == 0) {
1062 		op = &args->ops[resp->opcnt++];
1063 		op->status = nfserr_retry_uncached_rep;
1064 		nfsd4_encode_operation(resp, op);
1065 	}
1066 	return op->status;
1067 }
1068 
1069 /*
1070  * The sequence operation is not cached because we can use the slot and
1071  * session values.
1072  */
1073 __be32
1074 nfsd4_replay_cache_entry(struct nfsd4_compoundres *resp,
1075 			 struct nfsd4_sequence *seq)
1076 {
1077 	struct nfsd4_slot *slot = resp->cstate.slot;
1078 	__be32 status;
1079 
1080 	dprintk("--> %s slot %p\n", __func__, slot);
1081 
1082 	/* Either returns 0 or nfserr_retry_uncached */
1083 	status = nfsd4_enc_sequence_replay(resp->rqstp->rq_argp, resp);
1084 	if (status == nfserr_retry_uncached_rep)
1085 		return status;
1086 
1087 	/* The sequence operation has been encoded, cstate->datap set. */
1088 	memcpy(resp->cstate.datap, slot->sl_data, slot->sl_datalen);
1089 
1090 	resp->opcnt = slot->sl_opcnt;
1091 	resp->p = resp->cstate.datap + XDR_QUADLEN(slot->sl_datalen);
1092 	status = slot->sl_status;
1093 
1094 	return status;
1095 }
1096 
1097 /*
1098  * Set the exchange_id flags returned by the server.
1099  */
1100 static void
1101 nfsd4_set_ex_flags(struct nfs4_client *new, struct nfsd4_exchange_id *clid)
1102 {
1103 	/* pNFS is not supported */
1104 	new->cl_exchange_flags |= EXCHGID4_FLAG_USE_NON_PNFS;
1105 
1106 	/* Referrals are supported, Migration is not. */
1107 	new->cl_exchange_flags |= EXCHGID4_FLAG_SUPP_MOVED_REFER;
1108 
1109 	/* set the wire flags to return to client. */
1110 	clid->flags = new->cl_exchange_flags;
1111 }
1112 
1113 __be32
1114 nfsd4_exchange_id(struct svc_rqst *rqstp,
1115 		  struct nfsd4_compound_state *cstate,
1116 		  struct nfsd4_exchange_id *exid)
1117 {
1118 	struct nfs4_client *unconf, *conf, *new;
1119 	int status;
1120 	unsigned int		strhashval;
1121 	char			dname[HEXDIR_LEN];
1122 	char			addr_str[INET6_ADDRSTRLEN];
1123 	nfs4_verifier		verf = exid->verifier;
1124 	struct sockaddr		*sa = svc_addr(rqstp);
1125 
1126 	rpc_ntop(sa, addr_str, sizeof(addr_str));
1127 	dprintk("%s rqstp=%p exid=%p clname.len=%u clname.data=%p "
1128 		"ip_addr=%s flags %x, spa_how %d\n",
1129 		__func__, rqstp, exid, exid->clname.len, exid->clname.data,
1130 		addr_str, exid->flags, exid->spa_how);
1131 
1132 	if (!check_name(exid->clname) || (exid->flags & ~EXCHGID4_FLAG_MASK_A))
1133 		return nfserr_inval;
1134 
1135 	/* Currently only support SP4_NONE */
1136 	switch (exid->spa_how) {
1137 	case SP4_NONE:
1138 		break;
1139 	case SP4_SSV:
1140 		return nfserr_encr_alg_unsupp;
1141 	default:
1142 		BUG();				/* checked by xdr code */
1143 	case SP4_MACH_CRED:
1144 		return nfserr_serverfault;	/* no excuse :-/ */
1145 	}
1146 
1147 	status = nfs4_make_rec_clidname(dname, &exid->clname);
1148 
1149 	if (status)
1150 		goto error;
1151 
1152 	strhashval = clientstr_hashval(dname);
1153 
1154 	nfs4_lock_state();
1155 	status = nfs_ok;
1156 
1157 	conf = find_confirmed_client_by_str(dname, strhashval, true);
1158 	if (conf) {
1159 		if (!same_verf(&verf, &conf->cl_verifier)) {
1160 			/* 18.35.4 case 8 */
1161 			if (exid->flags & EXCHGID4_FLAG_UPD_CONFIRMED_REC_A) {
1162 				status = nfserr_not_same;
1163 				goto out;
1164 			}
1165 			/* Client reboot: destroy old state */
1166 			expire_client(conf);
1167 			goto out_new;
1168 		}
1169 		if (!same_creds(&conf->cl_cred, &rqstp->rq_cred)) {
1170 			/* 18.35.4 case 9 */
1171 			if (exid->flags & EXCHGID4_FLAG_UPD_CONFIRMED_REC_A) {
1172 				status = nfserr_perm;
1173 				goto out;
1174 			}
1175 			expire_client(conf);
1176 			goto out_new;
1177 		}
1178 		/*
1179 		 * Set bit when the owner id and verifier map to an already
1180 		 * confirmed client id (18.35.3).
1181 		 */
1182 		exid->flags |= EXCHGID4_FLAG_CONFIRMED_R;
1183 
1184 		/*
1185 		 * Falling into 18.35.4 case 2, possible router replay.
1186 		 * Leave confirmed record intact and return same result.
1187 		 */
1188 		copy_verf(conf, &verf);
1189 		new = conf;
1190 		goto out_copy;
1191 	}
1192 
1193 	/* 18.35.4 case 7 */
1194 	if (exid->flags & EXCHGID4_FLAG_UPD_CONFIRMED_REC_A) {
1195 		status = nfserr_noent;
1196 		goto out;
1197 	}
1198 
1199 	unconf  = find_unconfirmed_client_by_str(dname, strhashval, true);
1200 	if (unconf) {
1201 		/*
1202 		 * Possible retry or client restart.  Per 18.35.4 case 4,
1203 		 * a new unconfirmed record should be generated regardless
1204 		 * of whether any properties have changed.
1205 		 */
1206 		expire_client(unconf);
1207 	}
1208 
1209 out_new:
1210 	/* Normal case */
1211 	new = create_client(exid->clname, dname, rqstp, &verf);
1212 	if (new == NULL) {
1213 		status = nfserr_serverfault;
1214 		goto out;
1215 	}
1216 
1217 	gen_clid(new);
1218 	add_to_unconfirmed(new, strhashval);
1219 out_copy:
1220 	exid->clientid.cl_boot = new->cl_clientid.cl_boot;
1221 	exid->clientid.cl_id = new->cl_clientid.cl_id;
1222 
1223 	exid->seqid = 1;
1224 	nfsd4_set_ex_flags(new, exid);
1225 
1226 	dprintk("nfsd4_exchange_id seqid %d flags %x\n",
1227 		new->cl_cs_slot.sl_seqid, new->cl_exchange_flags);
1228 	status = nfs_ok;
1229 
1230 out:
1231 	nfs4_unlock_state();
1232 error:
1233 	dprintk("nfsd4_exchange_id returns %d\n", ntohl(status));
1234 	return status;
1235 }
1236 
1237 static int
1238 check_slot_seqid(u32 seqid, u32 slot_seqid, int slot_inuse)
1239 {
1240 	dprintk("%s enter. seqid %d slot_seqid %d\n", __func__, seqid,
1241 		slot_seqid);
1242 
1243 	/* The slot is in use, and no response has been sent. */
1244 	if (slot_inuse) {
1245 		if (seqid == slot_seqid)
1246 			return nfserr_jukebox;
1247 		else
1248 			return nfserr_seq_misordered;
1249 	}
1250 	/* Normal */
1251 	if (likely(seqid == slot_seqid + 1))
1252 		return nfs_ok;
1253 	/* Replay */
1254 	if (seqid == slot_seqid)
1255 		return nfserr_replay_cache;
1256 	/* Wraparound */
1257 	if (seqid == 1 && (slot_seqid + 1) == 0)
1258 		return nfs_ok;
1259 	/* Misordered replay or misordered new request */
1260 	return nfserr_seq_misordered;
1261 }
1262 
1263 /*
1264  * Cache the create session result into the create session single DRC
1265  * slot cache by saving the xdr structure. sl_seqid has been set.
1266  * Do this for solo or embedded create session operations.
1267  */
1268 static void
1269 nfsd4_cache_create_session(struct nfsd4_create_session *cr_ses,
1270 			   struct nfsd4_clid_slot *slot, int nfserr)
1271 {
1272 	slot->sl_status = nfserr;
1273 	memcpy(&slot->sl_cr_ses, cr_ses, sizeof(*cr_ses));
1274 }
1275 
1276 static __be32
1277 nfsd4_replay_create_session(struct nfsd4_create_session *cr_ses,
1278 			    struct nfsd4_clid_slot *slot)
1279 {
1280 	memcpy(cr_ses, &slot->sl_cr_ses, sizeof(*cr_ses));
1281 	return slot->sl_status;
1282 }
1283 
1284 __be32
1285 nfsd4_create_session(struct svc_rqst *rqstp,
1286 		     struct nfsd4_compound_state *cstate,
1287 		     struct nfsd4_create_session *cr_ses)
1288 {
1289 	struct sockaddr *sa = svc_addr(rqstp);
1290 	struct nfs4_client *conf, *unconf;
1291 	struct nfsd4_clid_slot *cs_slot = NULL;
1292 	int status = 0;
1293 
1294 	nfs4_lock_state();
1295 	unconf = find_unconfirmed_client(&cr_ses->clientid);
1296 	conf = find_confirmed_client(&cr_ses->clientid);
1297 
1298 	if (conf) {
1299 		cs_slot = &conf->cl_cs_slot;
1300 		status = check_slot_seqid(cr_ses->seqid, cs_slot->sl_seqid, 0);
1301 		if (status == nfserr_replay_cache) {
1302 			dprintk("Got a create_session replay! seqid= %d\n",
1303 				cs_slot->sl_seqid);
1304 			/* Return the cached reply status */
1305 			status = nfsd4_replay_create_session(cr_ses, cs_slot);
1306 			goto out;
1307 		} else if (cr_ses->seqid != cs_slot->sl_seqid + 1) {
1308 			status = nfserr_seq_misordered;
1309 			dprintk("Sequence misordered!\n");
1310 			dprintk("Expected seqid= %d but got seqid= %d\n",
1311 				cs_slot->sl_seqid, cr_ses->seqid);
1312 			goto out;
1313 		}
1314 		cs_slot->sl_seqid++;
1315 	} else if (unconf) {
1316 		if (!same_creds(&unconf->cl_cred, &rqstp->rq_cred) ||
1317 		    !rpc_cmp_addr(sa, (struct sockaddr *) &unconf->cl_addr)) {
1318 			status = nfserr_clid_inuse;
1319 			goto out;
1320 		}
1321 
1322 		cs_slot = &unconf->cl_cs_slot;
1323 		status = check_slot_seqid(cr_ses->seqid, cs_slot->sl_seqid, 0);
1324 		if (status) {
1325 			/* an unconfirmed replay returns misordered */
1326 			status = nfserr_seq_misordered;
1327 			goto out_cache;
1328 		}
1329 
1330 		cs_slot->sl_seqid++; /* from 0 to 1 */
1331 		move_to_confirmed(unconf);
1332 
1333 		/*
1334 		 * We do not support RDMA or persistent sessions
1335 		 */
1336 		cr_ses->flags &= ~SESSION4_PERSIST;
1337 		cr_ses->flags &= ~SESSION4_RDMA;
1338 
1339 		if (cr_ses->flags & SESSION4_BACK_CHAN) {
1340 			unconf->cl_cb_xprt = rqstp->rq_xprt;
1341 			svc_xprt_get(unconf->cl_cb_xprt);
1342 			rpc_copy_addr(
1343 				(struct sockaddr *)&unconf->cl_cb_conn.cb_addr,
1344 				sa);
1345 			unconf->cl_cb_conn.cb_addrlen = svc_addr_len(sa);
1346 			unconf->cl_cb_conn.cb_minorversion =
1347 				cstate->minorversion;
1348 			unconf->cl_cb_conn.cb_prog = cr_ses->callback_prog;
1349 			unconf->cl_cb_seq_nr = 1;
1350 			nfsd4_probe_callback(unconf);
1351 		}
1352 		conf = unconf;
1353 	} else {
1354 		status = nfserr_stale_clientid;
1355 		goto out;
1356 	}
1357 
1358 	status = alloc_init_session(rqstp, conf, cr_ses);
1359 	if (status)
1360 		goto out;
1361 
1362 	memcpy(cr_ses->sessionid.data, conf->cl_sessionid.data,
1363 	       NFS4_MAX_SESSIONID_LEN);
1364 	cr_ses->seqid = cs_slot->sl_seqid;
1365 
1366 out_cache:
1367 	/* cache solo and embedded create sessions under the state lock */
1368 	nfsd4_cache_create_session(cr_ses, cs_slot, status);
1369 out:
1370 	nfs4_unlock_state();
1371 	dprintk("%s returns %d\n", __func__, ntohl(status));
1372 	return status;
1373 }
1374 
1375 __be32
1376 nfsd4_destroy_session(struct svc_rqst *r,
1377 		      struct nfsd4_compound_state *cstate,
1378 		      struct nfsd4_destroy_session *sessionid)
1379 {
1380 	struct nfsd4_session *ses;
1381 	u32 status = nfserr_badsession;
1382 
1383 	/* Notes:
1384 	 * - The confirmed nfs4_client->cl_sessionid holds destroyed sessinid
1385 	 * - Should we return nfserr_back_chan_busy if waiting for
1386 	 *   callbacks on to-be-destroyed session?
1387 	 * - Do we need to clear any callback info from previous session?
1388 	 */
1389 
1390 	dump_sessionid(__func__, &sessionid->sessionid);
1391 	spin_lock(&sessionid_lock);
1392 	ses = find_in_sessionid_hashtbl(&sessionid->sessionid);
1393 	if (!ses) {
1394 		spin_unlock(&sessionid_lock);
1395 		goto out;
1396 	}
1397 
1398 	unhash_session(ses);
1399 	spin_unlock(&sessionid_lock);
1400 
1401 	/* wait for callbacks */
1402 	shutdown_callback_client(ses->se_client);
1403 	nfsd4_put_session(ses);
1404 	status = nfs_ok;
1405 out:
1406 	dprintk("%s returns %d\n", __func__, ntohl(status));
1407 	return status;
1408 }
1409 
1410 __be32
1411 nfsd4_sequence(struct svc_rqst *rqstp,
1412 	       struct nfsd4_compound_state *cstate,
1413 	       struct nfsd4_sequence *seq)
1414 {
1415 	struct nfsd4_compoundres *resp = rqstp->rq_resp;
1416 	struct nfsd4_session *session;
1417 	struct nfsd4_slot *slot;
1418 	int status;
1419 
1420 	if (resp->opcnt != 1)
1421 		return nfserr_sequence_pos;
1422 
1423 	spin_lock(&sessionid_lock);
1424 	status = nfserr_badsession;
1425 	session = find_in_sessionid_hashtbl(&seq->sessionid);
1426 	if (!session)
1427 		goto out;
1428 
1429 	status = nfserr_badslot;
1430 	if (seq->slotid >= session->se_fchannel.maxreqs)
1431 		goto out;
1432 
1433 	slot = session->se_slots[seq->slotid];
1434 	dprintk("%s: slotid %d\n", __func__, seq->slotid);
1435 
1436 	/* We do not negotiate the number of slots yet, so set the
1437 	 * maxslots to the session maxreqs which is used to encode
1438 	 * sr_highest_slotid and the sr_target_slot id to maxslots */
1439 	seq->maxslots = session->se_fchannel.maxreqs;
1440 
1441 	status = check_slot_seqid(seq->seqid, slot->sl_seqid, slot->sl_inuse);
1442 	if (status == nfserr_replay_cache) {
1443 		cstate->slot = slot;
1444 		cstate->session = session;
1445 		/* Return the cached reply status and set cstate->status
1446 		 * for nfsd4_proc_compound processing */
1447 		status = nfsd4_replay_cache_entry(resp, seq);
1448 		cstate->status = nfserr_replay_cache;
1449 		goto out;
1450 	}
1451 	if (status)
1452 		goto out;
1453 
1454 	/* Success! bump slot seqid */
1455 	slot->sl_inuse = true;
1456 	slot->sl_seqid = seq->seqid;
1457 	slot->sl_cachethis = seq->cachethis;
1458 
1459 	cstate->slot = slot;
1460 	cstate->session = session;
1461 
1462 	/* Hold a session reference until done processing the compound:
1463 	 * nfsd4_put_session called only if the cstate slot is set.
1464 	 */
1465 	nfsd4_get_session(session);
1466 out:
1467 	spin_unlock(&sessionid_lock);
1468 	/* Renew the clientid on success and on replay */
1469 	if (cstate->session) {
1470 		nfs4_lock_state();
1471 		renew_client(session->se_client);
1472 		nfs4_unlock_state();
1473 	}
1474 	dprintk("%s: return %d\n", __func__, ntohl(status));
1475 	return status;
1476 }
1477 
1478 __be32
1479 nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
1480 		  struct nfsd4_setclientid *setclid)
1481 {
1482 	struct sockaddr		*sa = svc_addr(rqstp);
1483 	struct xdr_netobj 	clname = {
1484 		.len = setclid->se_namelen,
1485 		.data = setclid->se_name,
1486 	};
1487 	nfs4_verifier		clverifier = setclid->se_verf;
1488 	unsigned int 		strhashval;
1489 	struct nfs4_client	*conf, *unconf, *new;
1490 	__be32 			status;
1491 	char                    dname[HEXDIR_LEN];
1492 
1493 	if (!check_name(clname))
1494 		return nfserr_inval;
1495 
1496 	status = nfs4_make_rec_clidname(dname, &clname);
1497 	if (status)
1498 		return status;
1499 
1500 	/*
1501 	 * XXX The Duplicate Request Cache (DRC) has been checked (??)
1502 	 * We get here on a DRC miss.
1503 	 */
1504 
1505 	strhashval = clientstr_hashval(dname);
1506 
1507 	nfs4_lock_state();
1508 	conf = find_confirmed_client_by_str(dname, strhashval, false);
1509 	if (conf) {
1510 		/* RFC 3530 14.2.33 CASE 0: */
1511 		status = nfserr_clid_inuse;
1512 		if (!same_creds(&conf->cl_cred, &rqstp->rq_cred)) {
1513 			char addr_str[INET6_ADDRSTRLEN];
1514 			rpc_ntop((struct sockaddr *) &conf->cl_addr, addr_str,
1515 				 sizeof(addr_str));
1516 			dprintk("NFSD: setclientid: string in use by client "
1517 				"at %s\n", addr_str);
1518 			goto out;
1519 		}
1520 	}
1521 	/*
1522 	 * section 14.2.33 of RFC 3530 (under the heading "IMPLEMENTATION")
1523 	 * has a description of SETCLIENTID request processing consisting
1524 	 * of 5 bullet points, labeled as CASE0 - CASE4 below.
1525 	 */
1526 	unconf = find_unconfirmed_client_by_str(dname, strhashval, false);
1527 	status = nfserr_resource;
1528 	if (!conf) {
1529 		/*
1530 		 * RFC 3530 14.2.33 CASE 4:
1531 		 * placed first, because it is the normal case
1532 		 */
1533 		if (unconf)
1534 			expire_client(unconf);
1535 		new = create_client(clname, dname, rqstp, &clverifier);
1536 		if (new == NULL)
1537 			goto out;
1538 		gen_clid(new);
1539 	} else if (same_verf(&conf->cl_verifier, &clverifier)) {
1540 		/*
1541 		 * RFC 3530 14.2.33 CASE 1:
1542 		 * probable callback update
1543 		 */
1544 		if (unconf) {
1545 			/* Note this is removing unconfirmed {*x***},
1546 			 * which is stronger than RFC recommended {vxc**}.
1547 			 * This has the advantage that there is at most
1548 			 * one {*x***} in either list at any time.
1549 			 */
1550 			expire_client(unconf);
1551 		}
1552 		new = create_client(clname, dname, rqstp, &clverifier);
1553 		if (new == NULL)
1554 			goto out;
1555 		copy_clid(new, conf);
1556 	} else if (!unconf) {
1557 		/*
1558 		 * RFC 3530 14.2.33 CASE 2:
1559 		 * probable client reboot; state will be removed if
1560 		 * confirmed.
1561 		 */
1562 		new = create_client(clname, dname, rqstp, &clverifier);
1563 		if (new == NULL)
1564 			goto out;
1565 		gen_clid(new);
1566 	} else {
1567 		/*
1568 		 * RFC 3530 14.2.33 CASE 3:
1569 		 * probable client reboot; state will be removed if
1570 		 * confirmed.
1571 		 */
1572 		expire_client(unconf);
1573 		new = create_client(clname, dname, rqstp, &clverifier);
1574 		if (new == NULL)
1575 			goto out;
1576 		gen_clid(new);
1577 	}
1578 	gen_callback(new, setclid, rpc_get_scope_id(sa));
1579 	add_to_unconfirmed(new, strhashval);
1580 	setclid->se_clientid.cl_boot = new->cl_clientid.cl_boot;
1581 	setclid->se_clientid.cl_id = new->cl_clientid.cl_id;
1582 	memcpy(setclid->se_confirm.data, new->cl_confirm.data, sizeof(setclid->se_confirm.data));
1583 	status = nfs_ok;
1584 out:
1585 	nfs4_unlock_state();
1586 	return status;
1587 }
1588 
1589 
1590 /*
1591  * Section 14.2.34 of RFC 3530 (under the heading "IMPLEMENTATION") has
1592  * a description of SETCLIENTID_CONFIRM request processing consisting of 4
1593  * bullets, labeled as CASE1 - CASE4 below.
1594  */
1595 __be32
1596 nfsd4_setclientid_confirm(struct svc_rqst *rqstp,
1597 			 struct nfsd4_compound_state *cstate,
1598 			 struct nfsd4_setclientid_confirm *setclientid_confirm)
1599 {
1600 	struct sockaddr *sa = svc_addr(rqstp);
1601 	struct nfs4_client *conf, *unconf;
1602 	nfs4_verifier confirm = setclientid_confirm->sc_confirm;
1603 	clientid_t * clid = &setclientid_confirm->sc_clientid;
1604 	__be32 status;
1605 
1606 	if (STALE_CLIENTID(clid))
1607 		return nfserr_stale_clientid;
1608 	/*
1609 	 * XXX The Duplicate Request Cache (DRC) has been checked (??)
1610 	 * We get here on a DRC miss.
1611 	 */
1612 
1613 	nfs4_lock_state();
1614 
1615 	conf = find_confirmed_client(clid);
1616 	unconf = find_unconfirmed_client(clid);
1617 
1618 	status = nfserr_clid_inuse;
1619 	if (conf && !rpc_cmp_addr((struct sockaddr *) &conf->cl_addr, sa))
1620 		goto out;
1621 	if (unconf && !rpc_cmp_addr((struct sockaddr *) &unconf->cl_addr, sa))
1622 		goto out;
1623 
1624 	/*
1625 	 * section 14.2.34 of RFC 3530 has a description of
1626 	 * SETCLIENTID_CONFIRM request processing consisting
1627 	 * of 4 bullet points, labeled as CASE1 - CASE4 below.
1628 	 */
1629 	if (conf && unconf && same_verf(&confirm, &unconf->cl_confirm)) {
1630 		/*
1631 		 * RFC 3530 14.2.34 CASE 1:
1632 		 * callback update
1633 		 */
1634 		if (!same_creds(&conf->cl_cred, &unconf->cl_cred))
1635 			status = nfserr_clid_inuse;
1636 		else {
1637 			/* XXX: We just turn off callbacks until we can handle
1638 			  * change request correctly. */
1639 			atomic_set(&conf->cl_cb_conn.cb_set, 0);
1640 			expire_client(unconf);
1641 			status = nfs_ok;
1642 
1643 		}
1644 	} else if (conf && !unconf) {
1645 		/*
1646 		 * RFC 3530 14.2.34 CASE 2:
1647 		 * probable retransmitted request; play it safe and
1648 		 * do nothing.
1649 		 */
1650 		if (!same_creds(&conf->cl_cred, &rqstp->rq_cred))
1651 			status = nfserr_clid_inuse;
1652 		else
1653 			status = nfs_ok;
1654 	} else if (!conf && unconf
1655 			&& same_verf(&unconf->cl_confirm, &confirm)) {
1656 		/*
1657 		 * RFC 3530 14.2.34 CASE 3:
1658 		 * Normal case; new or rebooted client:
1659 		 */
1660 		if (!same_creds(&unconf->cl_cred, &rqstp->rq_cred)) {
1661 			status = nfserr_clid_inuse;
1662 		} else {
1663 			unsigned int hash =
1664 				clientstr_hashval(unconf->cl_recdir);
1665 			conf = find_confirmed_client_by_str(unconf->cl_recdir,
1666 							    hash, false);
1667 			if (conf) {
1668 				nfsd4_remove_clid_dir(conf);
1669 				expire_client(conf);
1670 			}
1671 			move_to_confirmed(unconf);
1672 			conf = unconf;
1673 			nfsd4_probe_callback(conf);
1674 			status = nfs_ok;
1675 		}
1676 	} else if ((!conf || (conf && !same_verf(&conf->cl_confirm, &confirm)))
1677 	    && (!unconf || (unconf && !same_verf(&unconf->cl_confirm,
1678 				    				&confirm)))) {
1679 		/*
1680 		 * RFC 3530 14.2.34 CASE 4:
1681 		 * Client probably hasn't noticed that we rebooted yet.
1682 		 */
1683 		status = nfserr_stale_clientid;
1684 	} else {
1685 		/* check that we have hit one of the cases...*/
1686 		status = nfserr_clid_inuse;
1687 	}
1688 out:
1689 	nfs4_unlock_state();
1690 	return status;
1691 }
1692 
1693 /* OPEN Share state helper functions */
1694 static inline struct nfs4_file *
1695 alloc_init_file(struct inode *ino)
1696 {
1697 	struct nfs4_file *fp;
1698 	unsigned int hashval = file_hashval(ino);
1699 
1700 	fp = kmem_cache_alloc(file_slab, GFP_KERNEL);
1701 	if (fp) {
1702 		atomic_set(&fp->fi_ref, 1);
1703 		INIT_LIST_HEAD(&fp->fi_hash);
1704 		INIT_LIST_HEAD(&fp->fi_stateids);
1705 		INIT_LIST_HEAD(&fp->fi_delegations);
1706 		spin_lock(&recall_lock);
1707 		list_add(&fp->fi_hash, &file_hashtbl[hashval]);
1708 		spin_unlock(&recall_lock);
1709 		fp->fi_inode = igrab(ino);
1710 		fp->fi_id = current_fileid++;
1711 		fp->fi_had_conflict = false;
1712 		return fp;
1713 	}
1714 	return NULL;
1715 }
1716 
1717 static void
1718 nfsd4_free_slab(struct kmem_cache **slab)
1719 {
1720 	if (*slab == NULL)
1721 		return;
1722 	kmem_cache_destroy(*slab);
1723 	*slab = NULL;
1724 }
1725 
1726 void
1727 nfsd4_free_slabs(void)
1728 {
1729 	nfsd4_free_slab(&stateowner_slab);
1730 	nfsd4_free_slab(&file_slab);
1731 	nfsd4_free_slab(&stateid_slab);
1732 	nfsd4_free_slab(&deleg_slab);
1733 }
1734 
1735 static int
1736 nfsd4_init_slabs(void)
1737 {
1738 	stateowner_slab = kmem_cache_create("nfsd4_stateowners",
1739 			sizeof(struct nfs4_stateowner), 0, 0, NULL);
1740 	if (stateowner_slab == NULL)
1741 		goto out_nomem;
1742 	file_slab = kmem_cache_create("nfsd4_files",
1743 			sizeof(struct nfs4_file), 0, 0, NULL);
1744 	if (file_slab == NULL)
1745 		goto out_nomem;
1746 	stateid_slab = kmem_cache_create("nfsd4_stateids",
1747 			sizeof(struct nfs4_stateid), 0, 0, NULL);
1748 	if (stateid_slab == NULL)
1749 		goto out_nomem;
1750 	deleg_slab = kmem_cache_create("nfsd4_delegations",
1751 			sizeof(struct nfs4_delegation), 0, 0, NULL);
1752 	if (deleg_slab == NULL)
1753 		goto out_nomem;
1754 	return 0;
1755 out_nomem:
1756 	nfsd4_free_slabs();
1757 	dprintk("nfsd4: out of memory while initializing nfsv4\n");
1758 	return -ENOMEM;
1759 }
1760 
1761 void
1762 nfs4_free_stateowner(struct kref *kref)
1763 {
1764 	struct nfs4_stateowner *sop =
1765 		container_of(kref, struct nfs4_stateowner, so_ref);
1766 	kfree(sop->so_owner.data);
1767 	kmem_cache_free(stateowner_slab, sop);
1768 }
1769 
1770 static inline struct nfs4_stateowner *
1771 alloc_stateowner(struct xdr_netobj *owner)
1772 {
1773 	struct nfs4_stateowner *sop;
1774 
1775 	if ((sop = kmem_cache_alloc(stateowner_slab, GFP_KERNEL))) {
1776 		if ((sop->so_owner.data = kmalloc(owner->len, GFP_KERNEL))) {
1777 			memcpy(sop->so_owner.data, owner->data, owner->len);
1778 			sop->so_owner.len = owner->len;
1779 			kref_init(&sop->so_ref);
1780 			return sop;
1781 		}
1782 		kmem_cache_free(stateowner_slab, sop);
1783 	}
1784 	return NULL;
1785 }
1786 
1787 static struct nfs4_stateowner *
1788 alloc_init_open_stateowner(unsigned int strhashval, struct nfs4_client *clp, struct nfsd4_open *open) {
1789 	struct nfs4_stateowner *sop;
1790 	struct nfs4_replay *rp;
1791 	unsigned int idhashval;
1792 
1793 	if (!(sop = alloc_stateowner(&open->op_owner)))
1794 		return NULL;
1795 	idhashval = ownerid_hashval(current_ownerid);
1796 	INIT_LIST_HEAD(&sop->so_idhash);
1797 	INIT_LIST_HEAD(&sop->so_strhash);
1798 	INIT_LIST_HEAD(&sop->so_perclient);
1799 	INIT_LIST_HEAD(&sop->so_stateids);
1800 	INIT_LIST_HEAD(&sop->so_perstateid);  /* not used */
1801 	INIT_LIST_HEAD(&sop->so_close_lru);
1802 	sop->so_time = 0;
1803 	list_add(&sop->so_idhash, &ownerid_hashtbl[idhashval]);
1804 	list_add(&sop->so_strhash, &ownerstr_hashtbl[strhashval]);
1805 	list_add(&sop->so_perclient, &clp->cl_openowners);
1806 	sop->so_is_open_owner = 1;
1807 	sop->so_id = current_ownerid++;
1808 	sop->so_client = clp;
1809 	sop->so_seqid = open->op_seqid;
1810 	sop->so_confirmed = 0;
1811 	rp = &sop->so_replay;
1812 	rp->rp_status = nfserr_serverfault;
1813 	rp->rp_buflen = 0;
1814 	rp->rp_buf = rp->rp_ibuf;
1815 	return sop;
1816 }
1817 
1818 static inline void
1819 init_stateid(struct nfs4_stateid *stp, struct nfs4_file *fp, struct nfsd4_open *open) {
1820 	struct nfs4_stateowner *sop = open->op_stateowner;
1821 	unsigned int hashval = stateid_hashval(sop->so_id, fp->fi_id);
1822 
1823 	INIT_LIST_HEAD(&stp->st_hash);
1824 	INIT_LIST_HEAD(&stp->st_perstateowner);
1825 	INIT_LIST_HEAD(&stp->st_lockowners);
1826 	INIT_LIST_HEAD(&stp->st_perfile);
1827 	list_add(&stp->st_hash, &stateid_hashtbl[hashval]);
1828 	list_add(&stp->st_perstateowner, &sop->so_stateids);
1829 	list_add(&stp->st_perfile, &fp->fi_stateids);
1830 	stp->st_stateowner = sop;
1831 	get_nfs4_file(fp);
1832 	stp->st_file = fp;
1833 	stp->st_stateid.si_boot = get_seconds();
1834 	stp->st_stateid.si_stateownerid = sop->so_id;
1835 	stp->st_stateid.si_fileid = fp->fi_id;
1836 	stp->st_stateid.si_generation = 0;
1837 	stp->st_access_bmap = 0;
1838 	stp->st_deny_bmap = 0;
1839 	__set_bit(open->op_share_access & ~NFS4_SHARE_WANT_MASK,
1840 		  &stp->st_access_bmap);
1841 	__set_bit(open->op_share_deny, &stp->st_deny_bmap);
1842 	stp->st_openstp = NULL;
1843 }
1844 
1845 static void
1846 move_to_close_lru(struct nfs4_stateowner *sop)
1847 {
1848 	dprintk("NFSD: move_to_close_lru nfs4_stateowner %p\n", sop);
1849 
1850 	list_move_tail(&sop->so_close_lru, &close_lru);
1851 	sop->so_time = get_seconds();
1852 }
1853 
1854 static int
1855 same_owner_str(struct nfs4_stateowner *sop, struct xdr_netobj *owner,
1856 							clientid_t *clid)
1857 {
1858 	return (sop->so_owner.len == owner->len) &&
1859 		0 == memcmp(sop->so_owner.data, owner->data, owner->len) &&
1860 		(sop->so_client->cl_clientid.cl_id == clid->cl_id);
1861 }
1862 
1863 static struct nfs4_stateowner *
1864 find_openstateowner_str(unsigned int hashval, struct nfsd4_open *open)
1865 {
1866 	struct nfs4_stateowner *so = NULL;
1867 
1868 	list_for_each_entry(so, &ownerstr_hashtbl[hashval], so_strhash) {
1869 		if (same_owner_str(so, &open->op_owner, &open->op_clientid))
1870 			return so;
1871 	}
1872 	return NULL;
1873 }
1874 
1875 /* search file_hashtbl[] for file */
1876 static struct nfs4_file *
1877 find_file(struct inode *ino)
1878 {
1879 	unsigned int hashval = file_hashval(ino);
1880 	struct nfs4_file *fp;
1881 
1882 	spin_lock(&recall_lock);
1883 	list_for_each_entry(fp, &file_hashtbl[hashval], fi_hash) {
1884 		if (fp->fi_inode == ino) {
1885 			get_nfs4_file(fp);
1886 			spin_unlock(&recall_lock);
1887 			return fp;
1888 		}
1889 	}
1890 	spin_unlock(&recall_lock);
1891 	return NULL;
1892 }
1893 
1894 static inline int access_valid(u32 x, u32 minorversion)
1895 {
1896 	if ((x & NFS4_SHARE_ACCESS_MASK) < NFS4_SHARE_ACCESS_READ)
1897 		return 0;
1898 	if ((x & NFS4_SHARE_ACCESS_MASK) > NFS4_SHARE_ACCESS_BOTH)
1899 		return 0;
1900 	x &= ~NFS4_SHARE_ACCESS_MASK;
1901 	if (minorversion && x) {
1902 		if ((x & NFS4_SHARE_WANT_MASK) > NFS4_SHARE_WANT_CANCEL)
1903 			return 0;
1904 		if ((x & NFS4_SHARE_WHEN_MASK) > NFS4_SHARE_PUSH_DELEG_WHEN_UNCONTENDED)
1905 			return 0;
1906 		x &= ~(NFS4_SHARE_WANT_MASK | NFS4_SHARE_WHEN_MASK);
1907 	}
1908 	if (x)
1909 		return 0;
1910 	return 1;
1911 }
1912 
1913 static inline int deny_valid(u32 x)
1914 {
1915 	/* Note: unlike access bits, deny bits may be zero. */
1916 	return x <= NFS4_SHARE_DENY_BOTH;
1917 }
1918 
1919 /*
1920  * We store the NONE, READ, WRITE, and BOTH bits separately in the
1921  * st_{access,deny}_bmap field of the stateid, in order to track not
1922  * only what share bits are currently in force, but also what
1923  * combinations of share bits previous opens have used.  This allows us
1924  * to enforce the recommendation of rfc 3530 14.2.19 that the server
1925  * return an error if the client attempt to downgrade to a combination
1926  * of share bits not explicable by closing some of its previous opens.
1927  *
1928  * XXX: This enforcement is actually incomplete, since we don't keep
1929  * track of access/deny bit combinations; so, e.g., we allow:
1930  *
1931  *	OPEN allow read, deny write
1932  *	OPEN allow both, deny none
1933  *	DOWNGRADE allow read, deny none
1934  *
1935  * which we should reject.
1936  */
1937 static void
1938 set_access(unsigned int *access, unsigned long bmap) {
1939 	int i;
1940 
1941 	*access = 0;
1942 	for (i = 1; i < 4; i++) {
1943 		if (test_bit(i, &bmap))
1944 			*access |= i;
1945 	}
1946 }
1947 
1948 static void
1949 set_deny(unsigned int *deny, unsigned long bmap) {
1950 	int i;
1951 
1952 	*deny = 0;
1953 	for (i = 0; i < 4; i++) {
1954 		if (test_bit(i, &bmap))
1955 			*deny |= i ;
1956 	}
1957 }
1958 
1959 static int
1960 test_share(struct nfs4_stateid *stp, struct nfsd4_open *open) {
1961 	unsigned int access, deny;
1962 
1963 	set_access(&access, stp->st_access_bmap);
1964 	set_deny(&deny, stp->st_deny_bmap);
1965 	if ((access & open->op_share_deny) || (deny & open->op_share_access))
1966 		return 0;
1967 	return 1;
1968 }
1969 
1970 /*
1971  * Called to check deny when READ with all zero stateid or
1972  * WRITE with all zero or all one stateid
1973  */
1974 static __be32
1975 nfs4_share_conflict(struct svc_fh *current_fh, unsigned int deny_type)
1976 {
1977 	struct inode *ino = current_fh->fh_dentry->d_inode;
1978 	struct nfs4_file *fp;
1979 	struct nfs4_stateid *stp;
1980 	__be32 ret;
1981 
1982 	dprintk("NFSD: nfs4_share_conflict\n");
1983 
1984 	fp = find_file(ino);
1985 	if (!fp)
1986 		return nfs_ok;
1987 	ret = nfserr_locked;
1988 	/* Search for conflicting share reservations */
1989 	list_for_each_entry(stp, &fp->fi_stateids, st_perfile) {
1990 		if (test_bit(deny_type, &stp->st_deny_bmap) ||
1991 		    test_bit(NFS4_SHARE_DENY_BOTH, &stp->st_deny_bmap))
1992 			goto out;
1993 	}
1994 	ret = nfs_ok;
1995 out:
1996 	put_nfs4_file(fp);
1997 	return ret;
1998 }
1999 
2000 static inline void
2001 nfs4_file_downgrade(struct file *filp, unsigned int share_access)
2002 {
2003 	if (share_access & NFS4_SHARE_ACCESS_WRITE) {
2004 		drop_file_write_access(filp);
2005 		filp->f_mode = (filp->f_mode | FMODE_READ) & ~FMODE_WRITE;
2006 	}
2007 }
2008 
2009 /*
2010  * Spawn a thread to perform a recall on the delegation represented
2011  * by the lease (file_lock)
2012  *
2013  * Called from break_lease() with lock_kernel() held.
2014  * Note: we assume break_lease will only call this *once* for any given
2015  * lease.
2016  */
2017 static
2018 void nfsd_break_deleg_cb(struct file_lock *fl)
2019 {
2020 	struct nfs4_delegation *dp = (struct nfs4_delegation *)fl->fl_owner;
2021 
2022 	dprintk("NFSD nfsd_break_deleg_cb: dp %p fl %p\n",dp,fl);
2023 	if (!dp)
2024 		return;
2025 
2026 	/* We're assuming the state code never drops its reference
2027 	 * without first removing the lease.  Since we're in this lease
2028 	 * callback (and since the lease code is serialized by the kernel
2029 	 * lock) we know the server hasn't removed the lease yet, we know
2030 	 * it's safe to take a reference: */
2031 	atomic_inc(&dp->dl_count);
2032 	atomic_inc(&dp->dl_client->cl_count);
2033 
2034 	spin_lock(&recall_lock);
2035 	list_add_tail(&dp->dl_recall_lru, &del_recall_lru);
2036 	spin_unlock(&recall_lock);
2037 
2038 	/* only place dl_time is set. protected by lock_kernel*/
2039 	dp->dl_time = get_seconds();
2040 
2041 	/*
2042 	 * We don't want the locks code to timeout the lease for us;
2043 	 * we'll remove it ourself if the delegation isn't returned
2044 	 * in time.
2045 	 */
2046 	fl->fl_break_time = 0;
2047 
2048 	dp->dl_file->fi_had_conflict = true;
2049 	nfsd4_cb_recall(dp);
2050 }
2051 
2052 /*
2053  * The file_lock is being reapd.
2054  *
2055  * Called by locks_free_lock() with lock_kernel() held.
2056  */
2057 static
2058 void nfsd_release_deleg_cb(struct file_lock *fl)
2059 {
2060 	struct nfs4_delegation *dp = (struct nfs4_delegation *)fl->fl_owner;
2061 
2062 	dprintk("NFSD nfsd_release_deleg_cb: fl %p dp %p dl_count %d\n", fl,dp, atomic_read(&dp->dl_count));
2063 
2064 	if (!(fl->fl_flags & FL_LEASE) || !dp)
2065 		return;
2066 	dp->dl_flock = NULL;
2067 }
2068 
2069 /*
2070  * Set the delegation file_lock back pointer.
2071  *
2072  * Called from setlease() with lock_kernel() held.
2073  */
2074 static
2075 void nfsd_copy_lock_deleg_cb(struct file_lock *new, struct file_lock *fl)
2076 {
2077 	struct nfs4_delegation *dp = (struct nfs4_delegation *)new->fl_owner;
2078 
2079 	dprintk("NFSD: nfsd_copy_lock_deleg_cb: new fl %p dp %p\n", new, dp);
2080 	if (!dp)
2081 		return;
2082 	dp->dl_flock = new;
2083 }
2084 
2085 /*
2086  * Called from setlease() with lock_kernel() held
2087  */
2088 static
2089 int nfsd_same_client_deleg_cb(struct file_lock *onlist, struct file_lock *try)
2090 {
2091 	struct nfs4_delegation *onlistd =
2092 		(struct nfs4_delegation *)onlist->fl_owner;
2093 	struct nfs4_delegation *tryd =
2094 		(struct nfs4_delegation *)try->fl_owner;
2095 
2096 	if (onlist->fl_lmops != try->fl_lmops)
2097 		return 0;
2098 
2099 	return onlistd->dl_client == tryd->dl_client;
2100 }
2101 
2102 
2103 static
2104 int nfsd_change_deleg_cb(struct file_lock **onlist, int arg)
2105 {
2106 	if (arg & F_UNLCK)
2107 		return lease_modify(onlist, arg);
2108 	else
2109 		return -EAGAIN;
2110 }
2111 
2112 static const struct lock_manager_operations nfsd_lease_mng_ops = {
2113 	.fl_break = nfsd_break_deleg_cb,
2114 	.fl_release_private = nfsd_release_deleg_cb,
2115 	.fl_copy_lock = nfsd_copy_lock_deleg_cb,
2116 	.fl_mylease = nfsd_same_client_deleg_cb,
2117 	.fl_change = nfsd_change_deleg_cb,
2118 };
2119 
2120 
2121 __be32
2122 nfsd4_process_open1(struct nfsd4_compound_state *cstate,
2123 		    struct nfsd4_open *open)
2124 {
2125 	clientid_t *clientid = &open->op_clientid;
2126 	struct nfs4_client *clp = NULL;
2127 	unsigned int strhashval;
2128 	struct nfs4_stateowner *sop = NULL;
2129 
2130 	if (!check_name(open->op_owner))
2131 		return nfserr_inval;
2132 
2133 	if (STALE_CLIENTID(&open->op_clientid))
2134 		return nfserr_stale_clientid;
2135 
2136 	strhashval = ownerstr_hashval(clientid->cl_id, open->op_owner);
2137 	sop = find_openstateowner_str(strhashval, open);
2138 	open->op_stateowner = sop;
2139 	if (!sop) {
2140 		/* Make sure the client's lease hasn't expired. */
2141 		clp = find_confirmed_client(clientid);
2142 		if (clp == NULL)
2143 			return nfserr_expired;
2144 		goto renew;
2145 	}
2146 	/* When sessions are used, skip open sequenceid processing */
2147 	if (nfsd4_has_session(cstate))
2148 		goto renew;
2149 	if (!sop->so_confirmed) {
2150 		/* Replace unconfirmed owners without checking for replay. */
2151 		clp = sop->so_client;
2152 		release_openowner(sop);
2153 		open->op_stateowner = NULL;
2154 		goto renew;
2155 	}
2156 	if (open->op_seqid == sop->so_seqid - 1) {
2157 		if (sop->so_replay.rp_buflen)
2158 			return nfserr_replay_me;
2159 		/* The original OPEN failed so spectacularly
2160 		 * that we don't even have replay data saved!
2161 		 * Therefore, we have no choice but to continue
2162 		 * processing this OPEN; presumably, we'll
2163 		 * fail again for the same reason.
2164 		 */
2165 		dprintk("nfsd4_process_open1: replay with no replay cache\n");
2166 		goto renew;
2167 	}
2168 	if (open->op_seqid != sop->so_seqid)
2169 		return nfserr_bad_seqid;
2170 renew:
2171 	if (open->op_stateowner == NULL) {
2172 		sop = alloc_init_open_stateowner(strhashval, clp, open);
2173 		if (sop == NULL)
2174 			return nfserr_resource;
2175 		open->op_stateowner = sop;
2176 	}
2177 	list_del_init(&sop->so_close_lru);
2178 	renew_client(sop->so_client);
2179 	return nfs_ok;
2180 }
2181 
2182 static inline __be32
2183 nfs4_check_delegmode(struct nfs4_delegation *dp, int flags)
2184 {
2185 	if ((flags & WR_STATE) && (dp->dl_type == NFS4_OPEN_DELEGATE_READ))
2186 		return nfserr_openmode;
2187 	else
2188 		return nfs_ok;
2189 }
2190 
2191 static struct nfs4_delegation *
2192 find_delegation_file(struct nfs4_file *fp, stateid_t *stid)
2193 {
2194 	struct nfs4_delegation *dp;
2195 
2196 	list_for_each_entry(dp, &fp->fi_delegations, dl_perfile) {
2197 		if (dp->dl_stateid.si_stateownerid == stid->si_stateownerid)
2198 			return dp;
2199 	}
2200 	return NULL;
2201 }
2202 
2203 static __be32
2204 nfs4_check_deleg(struct nfs4_file *fp, struct nfsd4_open *open,
2205 		struct nfs4_delegation **dp)
2206 {
2207 	int flags;
2208 	__be32 status = nfserr_bad_stateid;
2209 
2210 	*dp = find_delegation_file(fp, &open->op_delegate_stateid);
2211 	if (*dp == NULL)
2212 		goto out;
2213 	flags = open->op_share_access == NFS4_SHARE_ACCESS_READ ?
2214 						RD_STATE : WR_STATE;
2215 	status = nfs4_check_delegmode(*dp, flags);
2216 	if (status)
2217 		*dp = NULL;
2218 out:
2219 	if (open->op_claim_type != NFS4_OPEN_CLAIM_DELEGATE_CUR)
2220 		return nfs_ok;
2221 	if (status)
2222 		return status;
2223 	open->op_stateowner->so_confirmed = 1;
2224 	return nfs_ok;
2225 }
2226 
2227 static __be32
2228 nfs4_check_open(struct nfs4_file *fp, struct nfsd4_open *open, struct nfs4_stateid **stpp)
2229 {
2230 	struct nfs4_stateid *local;
2231 	__be32 status = nfserr_share_denied;
2232 	struct nfs4_stateowner *sop = open->op_stateowner;
2233 
2234 	list_for_each_entry(local, &fp->fi_stateids, st_perfile) {
2235 		/* ignore lock owners */
2236 		if (local->st_stateowner->so_is_open_owner == 0)
2237 			continue;
2238 		/* remember if we have seen this open owner */
2239 		if (local->st_stateowner == sop)
2240 			*stpp = local;
2241 		/* check for conflicting share reservations */
2242 		if (!test_share(local, open))
2243 			goto out;
2244 	}
2245 	status = 0;
2246 out:
2247 	return status;
2248 }
2249 
2250 static inline struct nfs4_stateid *
2251 nfs4_alloc_stateid(void)
2252 {
2253 	return kmem_cache_alloc(stateid_slab, GFP_KERNEL);
2254 }
2255 
2256 static __be32
2257 nfs4_new_open(struct svc_rqst *rqstp, struct nfs4_stateid **stpp,
2258 		struct nfs4_delegation *dp,
2259 		struct svc_fh *cur_fh, int flags)
2260 {
2261 	struct nfs4_stateid *stp;
2262 
2263 	stp = nfs4_alloc_stateid();
2264 	if (stp == NULL)
2265 		return nfserr_resource;
2266 
2267 	if (dp) {
2268 		get_file(dp->dl_vfs_file);
2269 		stp->st_vfs_file = dp->dl_vfs_file;
2270 	} else {
2271 		__be32 status;
2272 		status = nfsd_open(rqstp, cur_fh, S_IFREG, flags,
2273 				&stp->st_vfs_file);
2274 		if (status) {
2275 			if (status == nfserr_dropit)
2276 				status = nfserr_jukebox;
2277 			kmem_cache_free(stateid_slab, stp);
2278 			return status;
2279 		}
2280 	}
2281 	*stpp = stp;
2282 	return 0;
2283 }
2284 
2285 static inline __be32
2286 nfsd4_truncate(struct svc_rqst *rqstp, struct svc_fh *fh,
2287 		struct nfsd4_open *open)
2288 {
2289 	struct iattr iattr = {
2290 		.ia_valid = ATTR_SIZE,
2291 		.ia_size = 0,
2292 	};
2293 	if (!open->op_truncate)
2294 		return 0;
2295 	if (!(open->op_share_access & NFS4_SHARE_ACCESS_WRITE))
2296 		return nfserr_inval;
2297 	return nfsd_setattr(rqstp, fh, &iattr, 0, (time_t)0);
2298 }
2299 
2300 static __be32
2301 nfs4_upgrade_open(struct svc_rqst *rqstp, struct svc_fh *cur_fh, struct nfs4_stateid *stp, struct nfsd4_open *open)
2302 {
2303 	struct file *filp = stp->st_vfs_file;
2304 	struct inode *inode = filp->f_path.dentry->d_inode;
2305 	unsigned int share_access, new_writer;
2306 	__be32 status;
2307 
2308 	set_access(&share_access, stp->st_access_bmap);
2309 	new_writer = (~share_access) & open->op_share_access
2310 			& NFS4_SHARE_ACCESS_WRITE;
2311 
2312 	if (new_writer) {
2313 		int err = get_write_access(inode);
2314 		if (err)
2315 			return nfserrno(err);
2316 		err = mnt_want_write(cur_fh->fh_export->ex_path.mnt);
2317 		if (err)
2318 			return nfserrno(err);
2319 		file_take_write(filp);
2320 	}
2321 	status = nfsd4_truncate(rqstp, cur_fh, open);
2322 	if (status) {
2323 		if (new_writer)
2324 			put_write_access(inode);
2325 		return status;
2326 	}
2327 	/* remember the open */
2328 	filp->f_mode |= open->op_share_access;
2329 	__set_bit(open->op_share_access, &stp->st_access_bmap);
2330 	__set_bit(open->op_share_deny, &stp->st_deny_bmap);
2331 
2332 	return nfs_ok;
2333 }
2334 
2335 
2336 static void
2337 nfs4_set_claim_prev(struct nfsd4_open *open)
2338 {
2339 	open->op_stateowner->so_confirmed = 1;
2340 	open->op_stateowner->so_client->cl_firststate = 1;
2341 }
2342 
2343 /*
2344  * Attempt to hand out a delegation.
2345  */
2346 static void
2347 nfs4_open_delegation(struct svc_fh *fh, struct nfsd4_open *open, struct nfs4_stateid *stp)
2348 {
2349 	struct nfs4_delegation *dp;
2350 	struct nfs4_stateowner *sop = stp->st_stateowner;
2351 	struct nfs4_cb_conn *cb = &sop->so_client->cl_cb_conn;
2352 	struct file_lock fl, *flp = &fl;
2353 	int status, flag = 0;
2354 
2355 	flag = NFS4_OPEN_DELEGATE_NONE;
2356 	open->op_recall = 0;
2357 	switch (open->op_claim_type) {
2358 		case NFS4_OPEN_CLAIM_PREVIOUS:
2359 			if (!atomic_read(&cb->cb_set))
2360 				open->op_recall = 1;
2361 			flag = open->op_delegate_type;
2362 			if (flag == NFS4_OPEN_DELEGATE_NONE)
2363 				goto out;
2364 			break;
2365 		case NFS4_OPEN_CLAIM_NULL:
2366 			/* Let's not give out any delegations till everyone's
2367 			 * had the chance to reclaim theirs.... */
2368 			if (locks_in_grace())
2369 				goto out;
2370 			if (!atomic_read(&cb->cb_set) || !sop->so_confirmed)
2371 				goto out;
2372 			if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE)
2373 				flag = NFS4_OPEN_DELEGATE_WRITE;
2374 			else
2375 				flag = NFS4_OPEN_DELEGATE_READ;
2376 			break;
2377 		default:
2378 			goto out;
2379 	}
2380 
2381 	dp = alloc_init_deleg(sop->so_client, stp, fh, flag);
2382 	if (dp == NULL) {
2383 		flag = NFS4_OPEN_DELEGATE_NONE;
2384 		goto out;
2385 	}
2386 	locks_init_lock(&fl);
2387 	fl.fl_lmops = &nfsd_lease_mng_ops;
2388 	fl.fl_flags = FL_LEASE;
2389 	fl.fl_type = flag == NFS4_OPEN_DELEGATE_READ? F_RDLCK: F_WRLCK;
2390 	fl.fl_end = OFFSET_MAX;
2391 	fl.fl_owner =  (fl_owner_t)dp;
2392 	fl.fl_file = stp->st_vfs_file;
2393 	fl.fl_pid = current->tgid;
2394 
2395 	/* vfs_setlease checks to see if delegation should be handed out.
2396 	 * the lock_manager callbacks fl_mylease and fl_change are used
2397 	 */
2398 	if ((status = vfs_setlease(stp->st_vfs_file, fl.fl_type, &flp))) {
2399 		dprintk("NFSD: setlease failed [%d], no delegation\n", status);
2400 		unhash_delegation(dp);
2401 		flag = NFS4_OPEN_DELEGATE_NONE;
2402 		goto out;
2403 	}
2404 
2405 	memcpy(&open->op_delegate_stateid, &dp->dl_stateid, sizeof(dp->dl_stateid));
2406 
2407 	dprintk("NFSD: delegation stateid=(%08x/%08x/%08x/%08x)\n\n",
2408 	             dp->dl_stateid.si_boot,
2409 	             dp->dl_stateid.si_stateownerid,
2410 	             dp->dl_stateid.si_fileid,
2411 	             dp->dl_stateid.si_generation);
2412 out:
2413 	if (open->op_claim_type == NFS4_OPEN_CLAIM_PREVIOUS
2414 			&& flag == NFS4_OPEN_DELEGATE_NONE
2415 			&& open->op_delegate_type != NFS4_OPEN_DELEGATE_NONE)
2416 		dprintk("NFSD: WARNING: refusing delegation reclaim\n");
2417 	open->op_delegate_type = flag;
2418 }
2419 
2420 /*
2421  * called with nfs4_lock_state() held.
2422  */
2423 __be32
2424 nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nfsd4_open *open)
2425 {
2426 	struct nfsd4_compoundres *resp = rqstp->rq_resp;
2427 	struct nfs4_file *fp = NULL;
2428 	struct inode *ino = current_fh->fh_dentry->d_inode;
2429 	struct nfs4_stateid *stp = NULL;
2430 	struct nfs4_delegation *dp = NULL;
2431 	__be32 status;
2432 
2433 	status = nfserr_inval;
2434 	if (!access_valid(open->op_share_access, resp->cstate.minorversion)
2435 			|| !deny_valid(open->op_share_deny))
2436 		goto out;
2437 	/*
2438 	 * Lookup file; if found, lookup stateid and check open request,
2439 	 * and check for delegations in the process of being recalled.
2440 	 * If not found, create the nfs4_file struct
2441 	 */
2442 	fp = find_file(ino);
2443 	if (fp) {
2444 		if ((status = nfs4_check_open(fp, open, &stp)))
2445 			goto out;
2446 		status = nfs4_check_deleg(fp, open, &dp);
2447 		if (status)
2448 			goto out;
2449 	} else {
2450 		status = nfserr_bad_stateid;
2451 		if (open->op_claim_type == NFS4_OPEN_CLAIM_DELEGATE_CUR)
2452 			goto out;
2453 		status = nfserr_resource;
2454 		fp = alloc_init_file(ino);
2455 		if (fp == NULL)
2456 			goto out;
2457 	}
2458 
2459 	/*
2460 	 * OPEN the file, or upgrade an existing OPEN.
2461 	 * If truncate fails, the OPEN fails.
2462 	 */
2463 	if (stp) {
2464 		/* Stateid was found, this is an OPEN upgrade */
2465 		status = nfs4_upgrade_open(rqstp, current_fh, stp, open);
2466 		if (status)
2467 			goto out;
2468 		update_stateid(&stp->st_stateid);
2469 	} else {
2470 		/* Stateid was not found, this is a new OPEN */
2471 		int flags = 0;
2472 		if (open->op_share_access & NFS4_SHARE_ACCESS_READ)
2473 			flags |= NFSD_MAY_READ;
2474 		if (open->op_share_access & NFS4_SHARE_ACCESS_WRITE)
2475 			flags |= NFSD_MAY_WRITE;
2476 		status = nfs4_new_open(rqstp, &stp, dp, current_fh, flags);
2477 		if (status)
2478 			goto out;
2479 		init_stateid(stp, fp, open);
2480 		status = nfsd4_truncate(rqstp, current_fh, open);
2481 		if (status) {
2482 			release_open_stateid(stp);
2483 			goto out;
2484 		}
2485 		if (nfsd4_has_session(&resp->cstate))
2486 			update_stateid(&stp->st_stateid);
2487 	}
2488 	memcpy(&open->op_stateid, &stp->st_stateid, sizeof(stateid_t));
2489 
2490 	if (nfsd4_has_session(&resp->cstate))
2491 		open->op_stateowner->so_confirmed = 1;
2492 
2493 	/*
2494 	* Attempt to hand out a delegation. No error return, because the
2495 	* OPEN succeeds even if we fail.
2496 	*/
2497 	nfs4_open_delegation(current_fh, open, stp);
2498 
2499 	status = nfs_ok;
2500 
2501 	dprintk("nfs4_process_open2: stateid=(%08x/%08x/%08x/%08x)\n",
2502 	            stp->st_stateid.si_boot, stp->st_stateid.si_stateownerid,
2503 	            stp->st_stateid.si_fileid, stp->st_stateid.si_generation);
2504 out:
2505 	if (fp)
2506 		put_nfs4_file(fp);
2507 	if (status == 0 && open->op_claim_type == NFS4_OPEN_CLAIM_PREVIOUS)
2508 		nfs4_set_claim_prev(open);
2509 	/*
2510 	* To finish the open response, we just need to set the rflags.
2511 	*/
2512 	open->op_rflags = NFS4_OPEN_RESULT_LOCKTYPE_POSIX;
2513 	if (!open->op_stateowner->so_confirmed &&
2514 	    !nfsd4_has_session(&resp->cstate))
2515 		open->op_rflags |= NFS4_OPEN_RESULT_CONFIRM;
2516 
2517 	return status;
2518 }
2519 
2520 __be32
2521 nfsd4_renew(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
2522 	    clientid_t *clid)
2523 {
2524 	struct nfs4_client *clp;
2525 	__be32 status;
2526 
2527 	nfs4_lock_state();
2528 	dprintk("process_renew(%08x/%08x): starting\n",
2529 			clid->cl_boot, clid->cl_id);
2530 	status = nfserr_stale_clientid;
2531 	if (STALE_CLIENTID(clid))
2532 		goto out;
2533 	clp = find_confirmed_client(clid);
2534 	status = nfserr_expired;
2535 	if (clp == NULL) {
2536 		/* We assume the client took too long to RENEW. */
2537 		dprintk("nfsd4_renew: clientid not found!\n");
2538 		goto out;
2539 	}
2540 	renew_client(clp);
2541 	status = nfserr_cb_path_down;
2542 	if (!list_empty(&clp->cl_delegations)
2543 			&& !atomic_read(&clp->cl_cb_conn.cb_set))
2544 		goto out;
2545 	status = nfs_ok;
2546 out:
2547 	nfs4_unlock_state();
2548 	return status;
2549 }
2550 
2551 struct lock_manager nfsd4_manager = {
2552 };
2553 
2554 static void
2555 nfsd4_end_grace(void)
2556 {
2557 	dprintk("NFSD: end of grace period\n");
2558 	nfsd4_recdir_purge_old();
2559 	locks_end_grace(&nfsd4_manager);
2560 }
2561 
2562 static time_t
2563 nfs4_laundromat(void)
2564 {
2565 	struct nfs4_client *clp;
2566 	struct nfs4_stateowner *sop;
2567 	struct nfs4_delegation *dp;
2568 	struct list_head *pos, *next, reaplist;
2569 	time_t cutoff = get_seconds() - NFSD_LEASE_TIME;
2570 	time_t t, clientid_val = NFSD_LEASE_TIME;
2571 	time_t u, test_val = NFSD_LEASE_TIME;
2572 
2573 	nfs4_lock_state();
2574 
2575 	dprintk("NFSD: laundromat service - starting\n");
2576 	if (locks_in_grace())
2577 		nfsd4_end_grace();
2578 	list_for_each_safe(pos, next, &client_lru) {
2579 		clp = list_entry(pos, struct nfs4_client, cl_lru);
2580 		if (time_after((unsigned long)clp->cl_time, (unsigned long)cutoff)) {
2581 			t = clp->cl_time - cutoff;
2582 			if (clientid_val > t)
2583 				clientid_val = t;
2584 			break;
2585 		}
2586 		dprintk("NFSD: purging unused client (clientid %08x)\n",
2587 			clp->cl_clientid.cl_id);
2588 		nfsd4_remove_clid_dir(clp);
2589 		expire_client(clp);
2590 	}
2591 	INIT_LIST_HEAD(&reaplist);
2592 	spin_lock(&recall_lock);
2593 	list_for_each_safe(pos, next, &del_recall_lru) {
2594 		dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru);
2595 		if (time_after((unsigned long)dp->dl_time, (unsigned long)cutoff)) {
2596 			u = dp->dl_time - cutoff;
2597 			if (test_val > u)
2598 				test_val = u;
2599 			break;
2600 		}
2601 		dprintk("NFSD: purging unused delegation dp %p, fp %p\n",
2602 			            dp, dp->dl_flock);
2603 		list_move(&dp->dl_recall_lru, &reaplist);
2604 	}
2605 	spin_unlock(&recall_lock);
2606 	list_for_each_safe(pos, next, &reaplist) {
2607 		dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru);
2608 		list_del_init(&dp->dl_recall_lru);
2609 		unhash_delegation(dp);
2610 	}
2611 	test_val = NFSD_LEASE_TIME;
2612 	list_for_each_safe(pos, next, &close_lru) {
2613 		sop = list_entry(pos, struct nfs4_stateowner, so_close_lru);
2614 		if (time_after((unsigned long)sop->so_time, (unsigned long)cutoff)) {
2615 			u = sop->so_time - cutoff;
2616 			if (test_val > u)
2617 				test_val = u;
2618 			break;
2619 		}
2620 		dprintk("NFSD: purging unused open stateowner (so_id %d)\n",
2621 			sop->so_id);
2622 		release_openowner(sop);
2623 	}
2624 	if (clientid_val < NFSD_LAUNDROMAT_MINTIMEOUT)
2625 		clientid_val = NFSD_LAUNDROMAT_MINTIMEOUT;
2626 	nfs4_unlock_state();
2627 	return clientid_val;
2628 }
2629 
2630 static struct workqueue_struct *laundry_wq;
2631 static void laundromat_main(struct work_struct *);
2632 static DECLARE_DELAYED_WORK(laundromat_work, laundromat_main);
2633 
2634 static void
2635 laundromat_main(struct work_struct *not_used)
2636 {
2637 	time_t t;
2638 
2639 	t = nfs4_laundromat();
2640 	dprintk("NFSD: laundromat_main - sleeping for %ld seconds\n", t);
2641 	queue_delayed_work(laundry_wq, &laundromat_work, t*HZ);
2642 }
2643 
2644 static struct nfs4_stateowner *
2645 search_close_lru(u32 st_id, int flags)
2646 {
2647 	struct nfs4_stateowner *local = NULL;
2648 
2649 	if (flags & CLOSE_STATE) {
2650 		list_for_each_entry(local, &close_lru, so_close_lru) {
2651 			if (local->so_id == st_id)
2652 				return local;
2653 		}
2654 	}
2655 	return NULL;
2656 }
2657 
2658 static inline int
2659 nfs4_check_fh(struct svc_fh *fhp, struct nfs4_stateid *stp)
2660 {
2661 	return fhp->fh_dentry->d_inode != stp->st_vfs_file->f_path.dentry->d_inode;
2662 }
2663 
2664 static int
2665 STALE_STATEID(stateid_t *stateid)
2666 {
2667 	if (time_after((unsigned long)boot_time,
2668 			(unsigned long)stateid->si_boot)) {
2669 		dprintk("NFSD: stale stateid (%08x/%08x/%08x/%08x)!\n",
2670 			stateid->si_boot, stateid->si_stateownerid,
2671 			stateid->si_fileid, stateid->si_generation);
2672 		return 1;
2673 	}
2674 	return 0;
2675 }
2676 
2677 static int
2678 EXPIRED_STATEID(stateid_t *stateid)
2679 {
2680 	if (time_before((unsigned long)boot_time,
2681 			((unsigned long)stateid->si_boot)) &&
2682 	    time_before((unsigned long)(stateid->si_boot + lease_time), get_seconds())) {
2683 		dprintk("NFSD: expired stateid (%08x/%08x/%08x/%08x)!\n",
2684 			stateid->si_boot, stateid->si_stateownerid,
2685 			stateid->si_fileid, stateid->si_generation);
2686 		return 1;
2687 	}
2688 	return 0;
2689 }
2690 
2691 static __be32
2692 stateid_error_map(stateid_t *stateid)
2693 {
2694 	if (STALE_STATEID(stateid))
2695 		return nfserr_stale_stateid;
2696 	if (EXPIRED_STATEID(stateid))
2697 		return nfserr_expired;
2698 
2699 	dprintk("NFSD: bad stateid (%08x/%08x/%08x/%08x)!\n",
2700 		stateid->si_boot, stateid->si_stateownerid,
2701 		stateid->si_fileid, stateid->si_generation);
2702 	return nfserr_bad_stateid;
2703 }
2704 
2705 static inline int
2706 access_permit_read(unsigned long access_bmap)
2707 {
2708 	return test_bit(NFS4_SHARE_ACCESS_READ, &access_bmap) ||
2709 		test_bit(NFS4_SHARE_ACCESS_BOTH, &access_bmap) ||
2710 		test_bit(NFS4_SHARE_ACCESS_WRITE, &access_bmap);
2711 }
2712 
2713 static inline int
2714 access_permit_write(unsigned long access_bmap)
2715 {
2716 	return test_bit(NFS4_SHARE_ACCESS_WRITE, &access_bmap) ||
2717 		test_bit(NFS4_SHARE_ACCESS_BOTH, &access_bmap);
2718 }
2719 
2720 static
2721 __be32 nfs4_check_openmode(struct nfs4_stateid *stp, int flags)
2722 {
2723         __be32 status = nfserr_openmode;
2724 
2725 	if ((flags & WR_STATE) && (!access_permit_write(stp->st_access_bmap)))
2726                 goto out;
2727 	if ((flags & RD_STATE) && (!access_permit_read(stp->st_access_bmap)))
2728                 goto out;
2729 	status = nfs_ok;
2730 out:
2731 	return status;
2732 }
2733 
2734 static inline __be32
2735 check_special_stateids(svc_fh *current_fh, stateid_t *stateid, int flags)
2736 {
2737 	if (ONE_STATEID(stateid) && (flags & RD_STATE))
2738 		return nfs_ok;
2739 	else if (locks_in_grace()) {
2740 		/* Answer in remaining cases depends on existance of
2741 		 * conflicting state; so we must wait out the grace period. */
2742 		return nfserr_grace;
2743 	} else if (flags & WR_STATE)
2744 		return nfs4_share_conflict(current_fh,
2745 				NFS4_SHARE_DENY_WRITE);
2746 	else /* (flags & RD_STATE) && ZERO_STATEID(stateid) */
2747 		return nfs4_share_conflict(current_fh,
2748 				NFS4_SHARE_DENY_READ);
2749 }
2750 
2751 /*
2752  * Allow READ/WRITE during grace period on recovered state only for files
2753  * that are not able to provide mandatory locking.
2754  */
2755 static inline int
2756 grace_disallows_io(struct inode *inode)
2757 {
2758 	return locks_in_grace() && mandatory_lock(inode);
2759 }
2760 
2761 static int check_stateid_generation(stateid_t *in, stateid_t *ref, int flags)
2762 {
2763 	/*
2764 	 * When sessions are used the stateid generation number is ignored
2765 	 * when it is zero.
2766 	 */
2767 	if ((flags & HAS_SESSION) && in->si_generation == 0)
2768 		goto out;
2769 
2770 	/* If the client sends us a stateid from the future, it's buggy: */
2771 	if (in->si_generation > ref->si_generation)
2772 		return nfserr_bad_stateid;
2773 	/*
2774 	 * The following, however, can happen.  For example, if the
2775 	 * client sends an open and some IO at the same time, the open
2776 	 * may bump si_generation while the IO is still in flight.
2777 	 * Thanks to hard links and renames, the client never knows what
2778 	 * file an open will affect.  So it could avoid that situation
2779 	 * only by serializing all opens and IO from the same open
2780 	 * owner.  To recover from the old_stateid error, the client
2781 	 * will just have to retry the IO:
2782 	 */
2783 	if (in->si_generation < ref->si_generation)
2784 		return nfserr_old_stateid;
2785 out:
2786 	return nfs_ok;
2787 }
2788 
2789 static int is_delegation_stateid(stateid_t *stateid)
2790 {
2791 	return stateid->si_fileid == 0;
2792 }
2793 
2794 /*
2795 * Checks for stateid operations
2796 */
2797 __be32
2798 nfs4_preprocess_stateid_op(struct nfsd4_compound_state *cstate,
2799 			   stateid_t *stateid, int flags, struct file **filpp)
2800 {
2801 	struct nfs4_stateid *stp = NULL;
2802 	struct nfs4_delegation *dp = NULL;
2803 	struct svc_fh *current_fh = &cstate->current_fh;
2804 	struct inode *ino = current_fh->fh_dentry->d_inode;
2805 	__be32 status;
2806 
2807 	if (filpp)
2808 		*filpp = NULL;
2809 
2810 	if (grace_disallows_io(ino))
2811 		return nfserr_grace;
2812 
2813 	if (nfsd4_has_session(cstate))
2814 		flags |= HAS_SESSION;
2815 
2816 	if (ZERO_STATEID(stateid) || ONE_STATEID(stateid))
2817 		return check_special_stateids(current_fh, stateid, flags);
2818 
2819 	status = nfserr_stale_stateid;
2820 	if (STALE_STATEID(stateid))
2821 		goto out;
2822 
2823 	status = nfserr_bad_stateid;
2824 	if (is_delegation_stateid(stateid)) {
2825 		dp = find_delegation_stateid(ino, stateid);
2826 		if (!dp) {
2827 			status = stateid_error_map(stateid);
2828 			goto out;
2829 		}
2830 		status = check_stateid_generation(stateid, &dp->dl_stateid,
2831 						  flags);
2832 		if (status)
2833 			goto out;
2834 		status = nfs4_check_delegmode(dp, flags);
2835 		if (status)
2836 			goto out;
2837 		renew_client(dp->dl_client);
2838 		if (filpp)
2839 			*filpp = dp->dl_vfs_file;
2840 	} else { /* open or lock stateid */
2841 		stp = find_stateid(stateid, flags);
2842 		if (!stp) {
2843 			status = stateid_error_map(stateid);
2844 			goto out;
2845 		}
2846 		if (nfs4_check_fh(current_fh, stp))
2847 			goto out;
2848 		if (!stp->st_stateowner->so_confirmed)
2849 			goto out;
2850 		status = check_stateid_generation(stateid, &stp->st_stateid,
2851 						  flags);
2852 		if (status)
2853 			goto out;
2854 		status = nfs4_check_openmode(stp, flags);
2855 		if (status)
2856 			goto out;
2857 		renew_client(stp->st_stateowner->so_client);
2858 		if (filpp)
2859 			*filpp = stp->st_vfs_file;
2860 	}
2861 	status = nfs_ok;
2862 out:
2863 	return status;
2864 }
2865 
2866 static inline int
2867 setlkflg (int type)
2868 {
2869 	return (type == NFS4_READW_LT || type == NFS4_READ_LT) ?
2870 		RD_STATE : WR_STATE;
2871 }
2872 
2873 /*
2874  * Checks for sequence id mutating operations.
2875  */
2876 static __be32
2877 nfs4_preprocess_seqid_op(struct nfsd4_compound_state *cstate, u32 seqid,
2878 			 stateid_t *stateid, int flags,
2879 			 struct nfs4_stateowner **sopp,
2880 			 struct nfs4_stateid **stpp, struct nfsd4_lock *lock)
2881 {
2882 	struct nfs4_stateid *stp;
2883 	struct nfs4_stateowner *sop;
2884 	struct svc_fh *current_fh = &cstate->current_fh;
2885 	__be32 status;
2886 
2887 	dprintk("NFSD: preprocess_seqid_op: seqid=%d "
2888 			"stateid = (%08x/%08x/%08x/%08x)\n", seqid,
2889 		stateid->si_boot, stateid->si_stateownerid, stateid->si_fileid,
2890 		stateid->si_generation);
2891 
2892 	*stpp = NULL;
2893 	*sopp = NULL;
2894 
2895 	if (ZERO_STATEID(stateid) || ONE_STATEID(stateid)) {
2896 		dprintk("NFSD: preprocess_seqid_op: magic stateid!\n");
2897 		return nfserr_bad_stateid;
2898 	}
2899 
2900 	if (STALE_STATEID(stateid))
2901 		return nfserr_stale_stateid;
2902 
2903 	if (nfsd4_has_session(cstate))
2904 		flags |= HAS_SESSION;
2905 
2906 	/*
2907 	* We return BAD_STATEID if filehandle doesn't match stateid,
2908 	* the confirmed flag is incorrecly set, or the generation
2909 	* number is incorrect.
2910 	*/
2911 	stp = find_stateid(stateid, flags);
2912 	if (stp == NULL) {
2913 		/*
2914 		 * Also, we should make sure this isn't just the result of
2915 		 * a replayed close:
2916 		 */
2917 		sop = search_close_lru(stateid->si_stateownerid, flags);
2918 		if (sop == NULL)
2919 			return stateid_error_map(stateid);
2920 		*sopp = sop;
2921 		goto check_replay;
2922 	}
2923 
2924 	*stpp = stp;
2925 	*sopp = sop = stp->st_stateowner;
2926 
2927 	if (lock) {
2928 		clientid_t *lockclid = &lock->v.new.clientid;
2929 		struct nfs4_client *clp = sop->so_client;
2930 		int lkflg = 0;
2931 		__be32 status;
2932 
2933 		lkflg = setlkflg(lock->lk_type);
2934 
2935 		if (lock->lk_is_new) {
2936 			if (!sop->so_is_open_owner)
2937 				return nfserr_bad_stateid;
2938 			if (!(flags & HAS_SESSION) &&
2939 			    !same_clid(&clp->cl_clientid, lockclid))
2940 				return nfserr_bad_stateid;
2941 			/* stp is the open stateid */
2942 			status = nfs4_check_openmode(stp, lkflg);
2943 			if (status)
2944 				return status;
2945 		} else {
2946 			/* stp is the lock stateid */
2947 			status = nfs4_check_openmode(stp->st_openstp, lkflg);
2948 			if (status)
2949 				return status;
2950                }
2951 	}
2952 
2953 	if (nfs4_check_fh(current_fh, stp)) {
2954 		dprintk("NFSD: preprocess_seqid_op: fh-stateid mismatch!\n");
2955 		return nfserr_bad_stateid;
2956 	}
2957 
2958 	/*
2959 	*  We now validate the seqid and stateid generation numbers.
2960 	*  For the moment, we ignore the possibility of
2961 	*  generation number wraparound.
2962 	*/
2963 	if (!(flags & HAS_SESSION) && seqid != sop->so_seqid)
2964 		goto check_replay;
2965 
2966 	if (sop->so_confirmed && flags & CONFIRM) {
2967 		dprintk("NFSD: preprocess_seqid_op: expected"
2968 				" unconfirmed stateowner!\n");
2969 		return nfserr_bad_stateid;
2970 	}
2971 	if (!sop->so_confirmed && !(flags & CONFIRM)) {
2972 		dprintk("NFSD: preprocess_seqid_op: stateowner not"
2973 				" confirmed yet!\n");
2974 		return nfserr_bad_stateid;
2975 	}
2976 	status = check_stateid_generation(stateid, &stp->st_stateid, flags);
2977 	if (status)
2978 		return status;
2979 	renew_client(sop->so_client);
2980 	return nfs_ok;
2981 
2982 check_replay:
2983 	if (seqid == sop->so_seqid - 1) {
2984 		dprintk("NFSD: preprocess_seqid_op: retransmission?\n");
2985 		/* indicate replay to calling function */
2986 		return nfserr_replay_me;
2987 	}
2988 	dprintk("NFSD: preprocess_seqid_op: bad seqid (expected %d, got %d)\n",
2989 			sop->so_seqid, seqid);
2990 	*sopp = NULL;
2991 	return nfserr_bad_seqid;
2992 }
2993 
2994 __be32
2995 nfsd4_open_confirm(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
2996 		   struct nfsd4_open_confirm *oc)
2997 {
2998 	__be32 status;
2999 	struct nfs4_stateowner *sop;
3000 	struct nfs4_stateid *stp;
3001 
3002 	dprintk("NFSD: nfsd4_open_confirm on file %.*s\n",
3003 			(int)cstate->current_fh.fh_dentry->d_name.len,
3004 			cstate->current_fh.fh_dentry->d_name.name);
3005 
3006 	status = fh_verify(rqstp, &cstate->current_fh, S_IFREG, 0);
3007 	if (status)
3008 		return status;
3009 
3010 	nfs4_lock_state();
3011 
3012 	if ((status = nfs4_preprocess_seqid_op(cstate,
3013 					oc->oc_seqid, &oc->oc_req_stateid,
3014 					CONFIRM | OPEN_STATE,
3015 					&oc->oc_stateowner, &stp, NULL)))
3016 		goto out;
3017 
3018 	sop = oc->oc_stateowner;
3019 	sop->so_confirmed = 1;
3020 	update_stateid(&stp->st_stateid);
3021 	memcpy(&oc->oc_resp_stateid, &stp->st_stateid, sizeof(stateid_t));
3022 	dprintk("NFSD: nfsd4_open_confirm: success, seqid=%d "
3023 		"stateid=(%08x/%08x/%08x/%08x)\n", oc->oc_seqid,
3024 		         stp->st_stateid.si_boot,
3025 		         stp->st_stateid.si_stateownerid,
3026 		         stp->st_stateid.si_fileid,
3027 		         stp->st_stateid.si_generation);
3028 
3029 	nfsd4_create_clid_dir(sop->so_client);
3030 out:
3031 	if (oc->oc_stateowner) {
3032 		nfs4_get_stateowner(oc->oc_stateowner);
3033 		cstate->replay_owner = oc->oc_stateowner;
3034 	}
3035 	nfs4_unlock_state();
3036 	return status;
3037 }
3038 
3039 
3040 /*
3041  * unset all bits in union bitmap (bmap) that
3042  * do not exist in share (from successful OPEN_DOWNGRADE)
3043  */
3044 static void
3045 reset_union_bmap_access(unsigned long access, unsigned long *bmap)
3046 {
3047 	int i;
3048 	for (i = 1; i < 4; i++) {
3049 		if ((i & access) != i)
3050 			__clear_bit(i, bmap);
3051 	}
3052 }
3053 
3054 static void
3055 reset_union_bmap_deny(unsigned long deny, unsigned long *bmap)
3056 {
3057 	int i;
3058 	for (i = 0; i < 4; i++) {
3059 		if ((i & deny) != i)
3060 			__clear_bit(i, bmap);
3061 	}
3062 }
3063 
3064 __be32
3065 nfsd4_open_downgrade(struct svc_rqst *rqstp,
3066 		     struct nfsd4_compound_state *cstate,
3067 		     struct nfsd4_open_downgrade *od)
3068 {
3069 	__be32 status;
3070 	struct nfs4_stateid *stp;
3071 	unsigned int share_access;
3072 
3073 	dprintk("NFSD: nfsd4_open_downgrade on file %.*s\n",
3074 			(int)cstate->current_fh.fh_dentry->d_name.len,
3075 			cstate->current_fh.fh_dentry->d_name.name);
3076 
3077 	if (!access_valid(od->od_share_access, cstate->minorversion)
3078 			|| !deny_valid(od->od_share_deny))
3079 		return nfserr_inval;
3080 
3081 	nfs4_lock_state();
3082 	if ((status = nfs4_preprocess_seqid_op(cstate,
3083 					od->od_seqid,
3084 					&od->od_stateid,
3085 					OPEN_STATE,
3086 					&od->od_stateowner, &stp, NULL)))
3087 		goto out;
3088 
3089 	status = nfserr_inval;
3090 	if (!test_bit(od->od_share_access, &stp->st_access_bmap)) {
3091 		dprintk("NFSD:access not a subset current bitmap: 0x%lx, input access=%08x\n",
3092 			stp->st_access_bmap, od->od_share_access);
3093 		goto out;
3094 	}
3095 	if (!test_bit(od->od_share_deny, &stp->st_deny_bmap)) {
3096 		dprintk("NFSD:deny not a subset current bitmap: 0x%lx, input deny=%08x\n",
3097 			stp->st_deny_bmap, od->od_share_deny);
3098 		goto out;
3099 	}
3100 	set_access(&share_access, stp->st_access_bmap);
3101 	nfs4_file_downgrade(stp->st_vfs_file,
3102 	                    share_access & ~od->od_share_access);
3103 
3104 	reset_union_bmap_access(od->od_share_access, &stp->st_access_bmap);
3105 	reset_union_bmap_deny(od->od_share_deny, &stp->st_deny_bmap);
3106 
3107 	update_stateid(&stp->st_stateid);
3108 	memcpy(&od->od_stateid, &stp->st_stateid, sizeof(stateid_t));
3109 	status = nfs_ok;
3110 out:
3111 	if (od->od_stateowner) {
3112 		nfs4_get_stateowner(od->od_stateowner);
3113 		cstate->replay_owner = od->od_stateowner;
3114 	}
3115 	nfs4_unlock_state();
3116 	return status;
3117 }
3118 
3119 /*
3120  * nfs4_unlock_state() called after encode
3121  */
3122 __be32
3123 nfsd4_close(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
3124 	    struct nfsd4_close *close)
3125 {
3126 	__be32 status;
3127 	struct nfs4_stateid *stp;
3128 
3129 	dprintk("NFSD: nfsd4_close on file %.*s\n",
3130 			(int)cstate->current_fh.fh_dentry->d_name.len,
3131 			cstate->current_fh.fh_dentry->d_name.name);
3132 
3133 	nfs4_lock_state();
3134 	/* check close_lru for replay */
3135 	if ((status = nfs4_preprocess_seqid_op(cstate,
3136 					close->cl_seqid,
3137 					&close->cl_stateid,
3138 					OPEN_STATE | CLOSE_STATE,
3139 					&close->cl_stateowner, &stp, NULL)))
3140 		goto out;
3141 	status = nfs_ok;
3142 	update_stateid(&stp->st_stateid);
3143 	memcpy(&close->cl_stateid, &stp->st_stateid, sizeof(stateid_t));
3144 
3145 	/* release_stateid() calls nfsd_close() if needed */
3146 	release_open_stateid(stp);
3147 
3148 	/* place unused nfs4_stateowners on so_close_lru list to be
3149 	 * released by the laundromat service after the lease period
3150 	 * to enable us to handle CLOSE replay
3151 	 */
3152 	if (list_empty(&close->cl_stateowner->so_stateids))
3153 		move_to_close_lru(close->cl_stateowner);
3154 out:
3155 	if (close->cl_stateowner) {
3156 		nfs4_get_stateowner(close->cl_stateowner);
3157 		cstate->replay_owner = close->cl_stateowner;
3158 	}
3159 	nfs4_unlock_state();
3160 	return status;
3161 }
3162 
3163 __be32
3164 nfsd4_delegreturn(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
3165 		  struct nfsd4_delegreturn *dr)
3166 {
3167 	struct nfs4_delegation *dp;
3168 	stateid_t *stateid = &dr->dr_stateid;
3169 	struct inode *inode;
3170 	__be32 status;
3171 	int flags = 0;
3172 
3173 	if ((status = fh_verify(rqstp, &cstate->current_fh, S_IFREG, 0)))
3174 		return status;
3175 	inode = cstate->current_fh.fh_dentry->d_inode;
3176 
3177 	if (nfsd4_has_session(cstate))
3178 		flags |= HAS_SESSION;
3179 	nfs4_lock_state();
3180 	status = nfserr_bad_stateid;
3181 	if (ZERO_STATEID(stateid) || ONE_STATEID(stateid))
3182 		goto out;
3183 	status = nfserr_stale_stateid;
3184 	if (STALE_STATEID(stateid))
3185 		goto out;
3186 	status = nfserr_bad_stateid;
3187 	if (!is_delegation_stateid(stateid))
3188 		goto out;
3189 	dp = find_delegation_stateid(inode, stateid);
3190 	if (!dp) {
3191 		status = stateid_error_map(stateid);
3192 		goto out;
3193 	}
3194 	status = check_stateid_generation(stateid, &dp->dl_stateid, flags);
3195 	if (status)
3196 		goto out;
3197 	renew_client(dp->dl_client);
3198 
3199 	unhash_delegation(dp);
3200 out:
3201 	nfs4_unlock_state();
3202 
3203 	return status;
3204 }
3205 
3206 
3207 /*
3208  * Lock owner state (byte-range locks)
3209  */
3210 #define LOFF_OVERFLOW(start, len)      ((u64)(len) > ~(u64)(start))
3211 #define LOCK_HASH_BITS              8
3212 #define LOCK_HASH_SIZE             (1 << LOCK_HASH_BITS)
3213 #define LOCK_HASH_MASK             (LOCK_HASH_SIZE - 1)
3214 
3215 static inline u64
3216 end_offset(u64 start, u64 len)
3217 {
3218 	u64 end;
3219 
3220 	end = start + len;
3221 	return end >= start ? end: NFS4_MAX_UINT64;
3222 }
3223 
3224 /* last octet in a range */
3225 static inline u64
3226 last_byte_offset(u64 start, u64 len)
3227 {
3228 	u64 end;
3229 
3230 	BUG_ON(!len);
3231 	end = start + len;
3232 	return end > start ? end - 1: NFS4_MAX_UINT64;
3233 }
3234 
3235 #define lockownerid_hashval(id) \
3236         ((id) & LOCK_HASH_MASK)
3237 
3238 static inline unsigned int
3239 lock_ownerstr_hashval(struct inode *inode, u32 cl_id,
3240 		struct xdr_netobj *ownername)
3241 {
3242 	return (file_hashval(inode) + cl_id
3243 			+ opaque_hashval(ownername->data, ownername->len))
3244 		& LOCK_HASH_MASK;
3245 }
3246 
3247 static struct list_head lock_ownerid_hashtbl[LOCK_HASH_SIZE];
3248 static struct list_head	lock_ownerstr_hashtbl[LOCK_HASH_SIZE];
3249 static struct list_head lockstateid_hashtbl[STATEID_HASH_SIZE];
3250 
3251 static struct nfs4_stateid *
3252 find_stateid(stateid_t *stid, int flags)
3253 {
3254 	struct nfs4_stateid *local;
3255 	u32 st_id = stid->si_stateownerid;
3256 	u32 f_id = stid->si_fileid;
3257 	unsigned int hashval;
3258 
3259 	dprintk("NFSD: find_stateid flags 0x%x\n",flags);
3260 	if (flags & (LOCK_STATE | RD_STATE | WR_STATE)) {
3261 		hashval = stateid_hashval(st_id, f_id);
3262 		list_for_each_entry(local, &lockstateid_hashtbl[hashval], st_hash) {
3263 			if ((local->st_stateid.si_stateownerid == st_id) &&
3264 			    (local->st_stateid.si_fileid == f_id))
3265 				return local;
3266 		}
3267 	}
3268 
3269 	if (flags & (OPEN_STATE | RD_STATE | WR_STATE)) {
3270 		hashval = stateid_hashval(st_id, f_id);
3271 		list_for_each_entry(local, &stateid_hashtbl[hashval], st_hash) {
3272 			if ((local->st_stateid.si_stateownerid == st_id) &&
3273 			    (local->st_stateid.si_fileid == f_id))
3274 				return local;
3275 		}
3276 	}
3277 	return NULL;
3278 }
3279 
3280 static struct nfs4_delegation *
3281 find_delegation_stateid(struct inode *ino, stateid_t *stid)
3282 {
3283 	struct nfs4_file *fp;
3284 	struct nfs4_delegation *dl;
3285 
3286 	dprintk("NFSD:find_delegation_stateid stateid=(%08x/%08x/%08x/%08x)\n",
3287                     stid->si_boot, stid->si_stateownerid,
3288                     stid->si_fileid, stid->si_generation);
3289 
3290 	fp = find_file(ino);
3291 	if (!fp)
3292 		return NULL;
3293 	dl = find_delegation_file(fp, stid);
3294 	put_nfs4_file(fp);
3295 	return dl;
3296 }
3297 
3298 /*
3299  * TODO: Linux file offsets are _signed_ 64-bit quantities, which means that
3300  * we can't properly handle lock requests that go beyond the (2^63 - 1)-th
3301  * byte, because of sign extension problems.  Since NFSv4 calls for 64-bit
3302  * locking, this prevents us from being completely protocol-compliant.  The
3303  * real solution to this problem is to start using unsigned file offsets in
3304  * the VFS, but this is a very deep change!
3305  */
3306 static inline void
3307 nfs4_transform_lock_offset(struct file_lock *lock)
3308 {
3309 	if (lock->fl_start < 0)
3310 		lock->fl_start = OFFSET_MAX;
3311 	if (lock->fl_end < 0)
3312 		lock->fl_end = OFFSET_MAX;
3313 }
3314 
3315 /* Hack!: For now, we're defining this just so we can use a pointer to it
3316  * as a unique cookie to identify our (NFSv4's) posix locks. */
3317 static const struct lock_manager_operations nfsd_posix_mng_ops  = {
3318 };
3319 
3320 static inline void
3321 nfs4_set_lock_denied(struct file_lock *fl, struct nfsd4_lock_denied *deny)
3322 {
3323 	struct nfs4_stateowner *sop;
3324 	unsigned int hval;
3325 
3326 	if (fl->fl_lmops == &nfsd_posix_mng_ops) {
3327 		sop = (struct nfs4_stateowner *) fl->fl_owner;
3328 		hval = lockownerid_hashval(sop->so_id);
3329 		kref_get(&sop->so_ref);
3330 		deny->ld_sop = sop;
3331 		deny->ld_clientid = sop->so_client->cl_clientid;
3332 	} else {
3333 		deny->ld_sop = NULL;
3334 		deny->ld_clientid.cl_boot = 0;
3335 		deny->ld_clientid.cl_id = 0;
3336 	}
3337 	deny->ld_start = fl->fl_start;
3338 	deny->ld_length = NFS4_MAX_UINT64;
3339 	if (fl->fl_end != NFS4_MAX_UINT64)
3340 		deny->ld_length = fl->fl_end - fl->fl_start + 1;
3341 	deny->ld_type = NFS4_READ_LT;
3342 	if (fl->fl_type != F_RDLCK)
3343 		deny->ld_type = NFS4_WRITE_LT;
3344 }
3345 
3346 static struct nfs4_stateowner *
3347 find_lockstateowner_str(struct inode *inode, clientid_t *clid,
3348 		struct xdr_netobj *owner)
3349 {
3350 	unsigned int hashval = lock_ownerstr_hashval(inode, clid->cl_id, owner);
3351 	struct nfs4_stateowner *op;
3352 
3353 	list_for_each_entry(op, &lock_ownerstr_hashtbl[hashval], so_strhash) {
3354 		if (same_owner_str(op, owner, clid))
3355 			return op;
3356 	}
3357 	return NULL;
3358 }
3359 
3360 /*
3361  * Alloc a lock owner structure.
3362  * Called in nfsd4_lock - therefore, OPEN and OPEN_CONFIRM (if needed) has
3363  * occured.
3364  *
3365  * strhashval = lock_ownerstr_hashval
3366  */
3367 
3368 static struct nfs4_stateowner *
3369 alloc_init_lock_stateowner(unsigned int strhashval, struct nfs4_client *clp, struct nfs4_stateid *open_stp, struct nfsd4_lock *lock) {
3370 	struct nfs4_stateowner *sop;
3371 	struct nfs4_replay *rp;
3372 	unsigned int idhashval;
3373 
3374 	if (!(sop = alloc_stateowner(&lock->lk_new_owner)))
3375 		return NULL;
3376 	idhashval = lockownerid_hashval(current_ownerid);
3377 	INIT_LIST_HEAD(&sop->so_idhash);
3378 	INIT_LIST_HEAD(&sop->so_strhash);
3379 	INIT_LIST_HEAD(&sop->so_perclient);
3380 	INIT_LIST_HEAD(&sop->so_stateids);
3381 	INIT_LIST_HEAD(&sop->so_perstateid);
3382 	INIT_LIST_HEAD(&sop->so_close_lru); /* not used */
3383 	sop->so_time = 0;
3384 	list_add(&sop->so_idhash, &lock_ownerid_hashtbl[idhashval]);
3385 	list_add(&sop->so_strhash, &lock_ownerstr_hashtbl[strhashval]);
3386 	list_add(&sop->so_perstateid, &open_stp->st_lockowners);
3387 	sop->so_is_open_owner = 0;
3388 	sop->so_id = current_ownerid++;
3389 	sop->so_client = clp;
3390 	/* It is the openowner seqid that will be incremented in encode in the
3391 	 * case of new lockowners; so increment the lock seqid manually: */
3392 	sop->so_seqid = lock->lk_new_lock_seqid + 1;
3393 	sop->so_confirmed = 1;
3394 	rp = &sop->so_replay;
3395 	rp->rp_status = nfserr_serverfault;
3396 	rp->rp_buflen = 0;
3397 	rp->rp_buf = rp->rp_ibuf;
3398 	return sop;
3399 }
3400 
3401 static struct nfs4_stateid *
3402 alloc_init_lock_stateid(struct nfs4_stateowner *sop, struct nfs4_file *fp, struct nfs4_stateid *open_stp)
3403 {
3404 	struct nfs4_stateid *stp;
3405 	unsigned int hashval = stateid_hashval(sop->so_id, fp->fi_id);
3406 
3407 	stp = nfs4_alloc_stateid();
3408 	if (stp == NULL)
3409 		goto out;
3410 	INIT_LIST_HEAD(&stp->st_hash);
3411 	INIT_LIST_HEAD(&stp->st_perfile);
3412 	INIT_LIST_HEAD(&stp->st_perstateowner);
3413 	INIT_LIST_HEAD(&stp->st_lockowners); /* not used */
3414 	list_add(&stp->st_hash, &lockstateid_hashtbl[hashval]);
3415 	list_add(&stp->st_perfile, &fp->fi_stateids);
3416 	list_add(&stp->st_perstateowner, &sop->so_stateids);
3417 	stp->st_stateowner = sop;
3418 	get_nfs4_file(fp);
3419 	stp->st_file = fp;
3420 	stp->st_stateid.si_boot = get_seconds();
3421 	stp->st_stateid.si_stateownerid = sop->so_id;
3422 	stp->st_stateid.si_fileid = fp->fi_id;
3423 	stp->st_stateid.si_generation = 0;
3424 	stp->st_vfs_file = open_stp->st_vfs_file; /* FIXME refcount?? */
3425 	stp->st_access_bmap = open_stp->st_access_bmap;
3426 	stp->st_deny_bmap = open_stp->st_deny_bmap;
3427 	stp->st_openstp = open_stp;
3428 
3429 out:
3430 	return stp;
3431 }
3432 
3433 static int
3434 check_lock_length(u64 offset, u64 length)
3435 {
3436 	return ((length == 0)  || ((length != NFS4_MAX_UINT64) &&
3437 	     LOFF_OVERFLOW(offset, length)));
3438 }
3439 
3440 /*
3441  *  LOCK operation
3442  */
3443 __be32
3444 nfsd4_lock(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
3445 	   struct nfsd4_lock *lock)
3446 {
3447 	struct nfs4_stateowner *open_sop = NULL;
3448 	struct nfs4_stateowner *lock_sop = NULL;
3449 	struct nfs4_stateid *lock_stp;
3450 	struct file *filp;
3451 	struct file_lock file_lock;
3452 	struct file_lock conflock;
3453 	__be32 status = 0;
3454 	unsigned int strhashval;
3455 	unsigned int cmd;
3456 	int err;
3457 
3458 	dprintk("NFSD: nfsd4_lock: start=%Ld length=%Ld\n",
3459 		(long long) lock->lk_offset,
3460 		(long long) lock->lk_length);
3461 
3462 	if (check_lock_length(lock->lk_offset, lock->lk_length))
3463 		 return nfserr_inval;
3464 
3465 	if ((status = fh_verify(rqstp, &cstate->current_fh,
3466 				S_IFREG, NFSD_MAY_LOCK))) {
3467 		dprintk("NFSD: nfsd4_lock: permission denied!\n");
3468 		return status;
3469 	}
3470 
3471 	nfs4_lock_state();
3472 
3473 	if (lock->lk_is_new) {
3474 		/*
3475 		 * Client indicates that this is a new lockowner.
3476 		 * Use open owner and open stateid to create lock owner and
3477 		 * lock stateid.
3478 		 */
3479 		struct nfs4_stateid *open_stp = NULL;
3480 		struct nfs4_file *fp;
3481 
3482 		status = nfserr_stale_clientid;
3483 		if (!nfsd4_has_session(cstate) &&
3484 		    STALE_CLIENTID(&lock->lk_new_clientid))
3485 			goto out;
3486 
3487 		/* validate and update open stateid and open seqid */
3488 		status = nfs4_preprocess_seqid_op(cstate,
3489 				        lock->lk_new_open_seqid,
3490 		                        &lock->lk_new_open_stateid,
3491 					OPEN_STATE,
3492 		                        &lock->lk_replay_owner, &open_stp,
3493 					lock);
3494 		if (status)
3495 			goto out;
3496 		open_sop = lock->lk_replay_owner;
3497 		/* create lockowner and lock stateid */
3498 		fp = open_stp->st_file;
3499 		strhashval = lock_ownerstr_hashval(fp->fi_inode,
3500 				open_sop->so_client->cl_clientid.cl_id,
3501 				&lock->v.new.owner);
3502 		/* XXX: Do we need to check for duplicate stateowners on
3503 		 * the same file, or should they just be allowed (and
3504 		 * create new stateids)? */
3505 		status = nfserr_resource;
3506 		lock_sop = alloc_init_lock_stateowner(strhashval,
3507 				open_sop->so_client, open_stp, lock);
3508 		if (lock_sop == NULL)
3509 			goto out;
3510 		lock_stp = alloc_init_lock_stateid(lock_sop, fp, open_stp);
3511 		if (lock_stp == NULL)
3512 			goto out;
3513 	} else {
3514 		/* lock (lock owner + lock stateid) already exists */
3515 		status = nfs4_preprocess_seqid_op(cstate,
3516 				       lock->lk_old_lock_seqid,
3517 				       &lock->lk_old_lock_stateid,
3518 				       LOCK_STATE,
3519 				       &lock->lk_replay_owner, &lock_stp, lock);
3520 		if (status)
3521 			goto out;
3522 		lock_sop = lock->lk_replay_owner;
3523 	}
3524 	/* lock->lk_replay_owner and lock_stp have been created or found */
3525 	filp = lock_stp->st_vfs_file;
3526 
3527 	status = nfserr_grace;
3528 	if (locks_in_grace() && !lock->lk_reclaim)
3529 		goto out;
3530 	status = nfserr_no_grace;
3531 	if (!locks_in_grace() && lock->lk_reclaim)
3532 		goto out;
3533 
3534 	locks_init_lock(&file_lock);
3535 	switch (lock->lk_type) {
3536 		case NFS4_READ_LT:
3537 		case NFS4_READW_LT:
3538 			file_lock.fl_type = F_RDLCK;
3539 			cmd = F_SETLK;
3540 		break;
3541 		case NFS4_WRITE_LT:
3542 		case NFS4_WRITEW_LT:
3543 			file_lock.fl_type = F_WRLCK;
3544 			cmd = F_SETLK;
3545 		break;
3546 		default:
3547 			status = nfserr_inval;
3548 		goto out;
3549 	}
3550 	file_lock.fl_owner = (fl_owner_t)lock_sop;
3551 	file_lock.fl_pid = current->tgid;
3552 	file_lock.fl_file = filp;
3553 	file_lock.fl_flags = FL_POSIX;
3554 	file_lock.fl_lmops = &nfsd_posix_mng_ops;
3555 
3556 	file_lock.fl_start = lock->lk_offset;
3557 	file_lock.fl_end = last_byte_offset(lock->lk_offset, lock->lk_length);
3558 	nfs4_transform_lock_offset(&file_lock);
3559 
3560 	/*
3561 	* Try to lock the file in the VFS.
3562 	* Note: locks.c uses the BKL to protect the inode's lock list.
3563 	*/
3564 
3565 	err = vfs_lock_file(filp, cmd, &file_lock, &conflock);
3566 	switch (-err) {
3567 	case 0: /* success! */
3568 		update_stateid(&lock_stp->st_stateid);
3569 		memcpy(&lock->lk_resp_stateid, &lock_stp->st_stateid,
3570 				sizeof(stateid_t));
3571 		status = 0;
3572 		break;
3573 	case (EAGAIN):		/* conflock holds conflicting lock */
3574 		status = nfserr_denied;
3575 		dprintk("NFSD: nfsd4_lock: conflicting lock found!\n");
3576 		nfs4_set_lock_denied(&conflock, &lock->lk_denied);
3577 		break;
3578 	case (EDEADLK):
3579 		status = nfserr_deadlock;
3580 		break;
3581 	default:
3582 		dprintk("NFSD: nfsd4_lock: vfs_lock_file() failed! status %d\n",err);
3583 		status = nfserr_resource;
3584 		break;
3585 	}
3586 out:
3587 	if (status && lock->lk_is_new && lock_sop)
3588 		release_lockowner(lock_sop);
3589 	if (lock->lk_replay_owner) {
3590 		nfs4_get_stateowner(lock->lk_replay_owner);
3591 		cstate->replay_owner = lock->lk_replay_owner;
3592 	}
3593 	nfs4_unlock_state();
3594 	return status;
3595 }
3596 
3597 /*
3598  * The NFSv4 spec allows a client to do a LOCKT without holding an OPEN,
3599  * so we do a temporary open here just to get an open file to pass to
3600  * vfs_test_lock.  (Arguably perhaps test_lock should be done with an
3601  * inode operation.)
3602  */
3603 static int nfsd_test_lock(struct svc_rqst *rqstp, struct svc_fh *fhp, struct file_lock *lock)
3604 {
3605 	struct file *file;
3606 	int err;
3607 
3608 	err = nfsd_open(rqstp, fhp, S_IFREG, NFSD_MAY_READ, &file);
3609 	if (err)
3610 		return err;
3611 	err = vfs_test_lock(file, lock);
3612 	nfsd_close(file);
3613 	return err;
3614 }
3615 
3616 /*
3617  * LOCKT operation
3618  */
3619 __be32
3620 nfsd4_lockt(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
3621 	    struct nfsd4_lockt *lockt)
3622 {
3623 	struct inode *inode;
3624 	struct file_lock file_lock;
3625 	int error;
3626 	__be32 status;
3627 
3628 	if (locks_in_grace())
3629 		return nfserr_grace;
3630 
3631 	if (check_lock_length(lockt->lt_offset, lockt->lt_length))
3632 		 return nfserr_inval;
3633 
3634 	lockt->lt_stateowner = NULL;
3635 	nfs4_lock_state();
3636 
3637 	status = nfserr_stale_clientid;
3638 	if (!nfsd4_has_session(cstate) && STALE_CLIENTID(&lockt->lt_clientid))
3639 		goto out;
3640 
3641 	if ((status = fh_verify(rqstp, &cstate->current_fh, S_IFREG, 0))) {
3642 		dprintk("NFSD: nfsd4_lockt: fh_verify() failed!\n");
3643 		if (status == nfserr_symlink)
3644 			status = nfserr_inval;
3645 		goto out;
3646 	}
3647 
3648 	inode = cstate->current_fh.fh_dentry->d_inode;
3649 	locks_init_lock(&file_lock);
3650 	switch (lockt->lt_type) {
3651 		case NFS4_READ_LT:
3652 		case NFS4_READW_LT:
3653 			file_lock.fl_type = F_RDLCK;
3654 		break;
3655 		case NFS4_WRITE_LT:
3656 		case NFS4_WRITEW_LT:
3657 			file_lock.fl_type = F_WRLCK;
3658 		break;
3659 		default:
3660 			dprintk("NFSD: nfs4_lockt: bad lock type!\n");
3661 			status = nfserr_inval;
3662 		goto out;
3663 	}
3664 
3665 	lockt->lt_stateowner = find_lockstateowner_str(inode,
3666 			&lockt->lt_clientid, &lockt->lt_owner);
3667 	if (lockt->lt_stateowner)
3668 		file_lock.fl_owner = (fl_owner_t)lockt->lt_stateowner;
3669 	file_lock.fl_pid = current->tgid;
3670 	file_lock.fl_flags = FL_POSIX;
3671 
3672 	file_lock.fl_start = lockt->lt_offset;
3673 	file_lock.fl_end = last_byte_offset(lockt->lt_offset, lockt->lt_length);
3674 
3675 	nfs4_transform_lock_offset(&file_lock);
3676 
3677 	status = nfs_ok;
3678 	error = nfsd_test_lock(rqstp, &cstate->current_fh, &file_lock);
3679 	if (error) {
3680 		status = nfserrno(error);
3681 		goto out;
3682 	}
3683 	if (file_lock.fl_type != F_UNLCK) {
3684 		status = nfserr_denied;
3685 		nfs4_set_lock_denied(&file_lock, &lockt->lt_denied);
3686 	}
3687 out:
3688 	nfs4_unlock_state();
3689 	return status;
3690 }
3691 
3692 __be32
3693 nfsd4_locku(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
3694 	    struct nfsd4_locku *locku)
3695 {
3696 	struct nfs4_stateid *stp;
3697 	struct file *filp = NULL;
3698 	struct file_lock file_lock;
3699 	__be32 status;
3700 	int err;
3701 
3702 	dprintk("NFSD: nfsd4_locku: start=%Ld length=%Ld\n",
3703 		(long long) locku->lu_offset,
3704 		(long long) locku->lu_length);
3705 
3706 	if (check_lock_length(locku->lu_offset, locku->lu_length))
3707 		 return nfserr_inval;
3708 
3709 	nfs4_lock_state();
3710 
3711 	if ((status = nfs4_preprocess_seqid_op(cstate,
3712 					locku->lu_seqid,
3713 					&locku->lu_stateid,
3714 					LOCK_STATE,
3715 					&locku->lu_stateowner, &stp, NULL)))
3716 		goto out;
3717 
3718 	filp = stp->st_vfs_file;
3719 	BUG_ON(!filp);
3720 	locks_init_lock(&file_lock);
3721 	file_lock.fl_type = F_UNLCK;
3722 	file_lock.fl_owner = (fl_owner_t) locku->lu_stateowner;
3723 	file_lock.fl_pid = current->tgid;
3724 	file_lock.fl_file = filp;
3725 	file_lock.fl_flags = FL_POSIX;
3726 	file_lock.fl_lmops = &nfsd_posix_mng_ops;
3727 	file_lock.fl_start = locku->lu_offset;
3728 
3729 	file_lock.fl_end = last_byte_offset(locku->lu_offset, locku->lu_length);
3730 	nfs4_transform_lock_offset(&file_lock);
3731 
3732 	/*
3733 	*  Try to unlock the file in the VFS.
3734 	*/
3735 	err = vfs_lock_file(filp, F_SETLK, &file_lock, NULL);
3736 	if (err) {
3737 		dprintk("NFSD: nfs4_locku: vfs_lock_file failed!\n");
3738 		goto out_nfserr;
3739 	}
3740 	/*
3741 	* OK, unlock succeeded; the only thing left to do is update the stateid.
3742 	*/
3743 	update_stateid(&stp->st_stateid);
3744 	memcpy(&locku->lu_stateid, &stp->st_stateid, sizeof(stateid_t));
3745 
3746 out:
3747 	if (locku->lu_stateowner) {
3748 		nfs4_get_stateowner(locku->lu_stateowner);
3749 		cstate->replay_owner = locku->lu_stateowner;
3750 	}
3751 	nfs4_unlock_state();
3752 	return status;
3753 
3754 out_nfserr:
3755 	status = nfserrno(err);
3756 	goto out;
3757 }
3758 
3759 /*
3760  * returns
3761  * 	1: locks held by lockowner
3762  * 	0: no locks held by lockowner
3763  */
3764 static int
3765 check_for_locks(struct file *filp, struct nfs4_stateowner *lowner)
3766 {
3767 	struct file_lock **flpp;
3768 	struct inode *inode = filp->f_path.dentry->d_inode;
3769 	int status = 0;
3770 
3771 	lock_kernel();
3772 	for (flpp = &inode->i_flock; *flpp != NULL; flpp = &(*flpp)->fl_next) {
3773 		if ((*flpp)->fl_owner == (fl_owner_t)lowner) {
3774 			status = 1;
3775 			goto out;
3776 		}
3777 	}
3778 out:
3779 	unlock_kernel();
3780 	return status;
3781 }
3782 
3783 __be32
3784 nfsd4_release_lockowner(struct svc_rqst *rqstp,
3785 			struct nfsd4_compound_state *cstate,
3786 			struct nfsd4_release_lockowner *rlockowner)
3787 {
3788 	clientid_t *clid = &rlockowner->rl_clientid;
3789 	struct nfs4_stateowner *sop;
3790 	struct nfs4_stateid *stp;
3791 	struct xdr_netobj *owner = &rlockowner->rl_owner;
3792 	struct list_head matches;
3793 	int i;
3794 	__be32 status;
3795 
3796 	dprintk("nfsd4_release_lockowner clientid: (%08x/%08x):\n",
3797 		clid->cl_boot, clid->cl_id);
3798 
3799 	/* XXX check for lease expiration */
3800 
3801 	status = nfserr_stale_clientid;
3802 	if (STALE_CLIENTID(clid))
3803 		return status;
3804 
3805 	nfs4_lock_state();
3806 
3807 	status = nfserr_locks_held;
3808 	/* XXX: we're doing a linear search through all the lockowners.
3809 	 * Yipes!  For now we'll just hope clients aren't really using
3810 	 * release_lockowner much, but eventually we have to fix these
3811 	 * data structures. */
3812 	INIT_LIST_HEAD(&matches);
3813 	for (i = 0; i < LOCK_HASH_SIZE; i++) {
3814 		list_for_each_entry(sop, &lock_ownerid_hashtbl[i], so_idhash) {
3815 			if (!same_owner_str(sop, owner, clid))
3816 				continue;
3817 			list_for_each_entry(stp, &sop->so_stateids,
3818 					st_perstateowner) {
3819 				if (check_for_locks(stp->st_vfs_file, sop))
3820 					goto out;
3821 				/* Note: so_perclient unused for lockowners,
3822 				 * so it's OK to fool with here. */
3823 				list_add(&sop->so_perclient, &matches);
3824 			}
3825 		}
3826 	}
3827 	/* Clients probably won't expect us to return with some (but not all)
3828 	 * of the lockowner state released; so don't release any until all
3829 	 * have been checked. */
3830 	status = nfs_ok;
3831 	while (!list_empty(&matches)) {
3832 		sop = list_entry(matches.next, struct nfs4_stateowner,
3833 								so_perclient);
3834 		/* unhash_stateowner deletes so_perclient only
3835 		 * for openowners. */
3836 		list_del(&sop->so_perclient);
3837 		release_lockowner(sop);
3838 	}
3839 out:
3840 	nfs4_unlock_state();
3841 	return status;
3842 }
3843 
3844 static inline struct nfs4_client_reclaim *
3845 alloc_reclaim(void)
3846 {
3847 	return kmalloc(sizeof(struct nfs4_client_reclaim), GFP_KERNEL);
3848 }
3849 
3850 int
3851 nfs4_has_reclaimed_state(const char *name, bool use_exchange_id)
3852 {
3853 	unsigned int strhashval = clientstr_hashval(name);
3854 	struct nfs4_client *clp;
3855 
3856 	clp = find_confirmed_client_by_str(name, strhashval, use_exchange_id);
3857 	return clp ? 1 : 0;
3858 }
3859 
3860 /*
3861  * failure => all reset bets are off, nfserr_no_grace...
3862  */
3863 int
3864 nfs4_client_to_reclaim(const char *name)
3865 {
3866 	unsigned int strhashval;
3867 	struct nfs4_client_reclaim *crp = NULL;
3868 
3869 	dprintk("NFSD nfs4_client_to_reclaim NAME: %.*s\n", HEXDIR_LEN, name);
3870 	crp = alloc_reclaim();
3871 	if (!crp)
3872 		return 0;
3873 	strhashval = clientstr_hashval(name);
3874 	INIT_LIST_HEAD(&crp->cr_strhash);
3875 	list_add(&crp->cr_strhash, &reclaim_str_hashtbl[strhashval]);
3876 	memcpy(crp->cr_recdir, name, HEXDIR_LEN);
3877 	reclaim_str_hashtbl_size++;
3878 	return 1;
3879 }
3880 
3881 static void
3882 nfs4_release_reclaim(void)
3883 {
3884 	struct nfs4_client_reclaim *crp = NULL;
3885 	int i;
3886 
3887 	for (i = 0; i < CLIENT_HASH_SIZE; i++) {
3888 		while (!list_empty(&reclaim_str_hashtbl[i])) {
3889 			crp = list_entry(reclaim_str_hashtbl[i].next,
3890 			                struct nfs4_client_reclaim, cr_strhash);
3891 			list_del(&crp->cr_strhash);
3892 			kfree(crp);
3893 			reclaim_str_hashtbl_size--;
3894 		}
3895 	}
3896 	BUG_ON(reclaim_str_hashtbl_size);
3897 }
3898 
3899 /*
3900  * called from OPEN, CLAIM_PREVIOUS with a new clientid. */
3901 static struct nfs4_client_reclaim *
3902 nfs4_find_reclaim_client(clientid_t *clid)
3903 {
3904 	unsigned int strhashval;
3905 	struct nfs4_client *clp;
3906 	struct nfs4_client_reclaim *crp = NULL;
3907 
3908 
3909 	/* find clientid in conf_id_hashtbl */
3910 	clp = find_confirmed_client(clid);
3911 	if (clp == NULL)
3912 		return NULL;
3913 
3914 	dprintk("NFSD: nfs4_find_reclaim_client for %.*s with recdir %s\n",
3915 		            clp->cl_name.len, clp->cl_name.data,
3916 			    clp->cl_recdir);
3917 
3918 	/* find clp->cl_name in reclaim_str_hashtbl */
3919 	strhashval = clientstr_hashval(clp->cl_recdir);
3920 	list_for_each_entry(crp, &reclaim_str_hashtbl[strhashval], cr_strhash) {
3921 		if (same_name(crp->cr_recdir, clp->cl_recdir)) {
3922 			return crp;
3923 		}
3924 	}
3925 	return NULL;
3926 }
3927 
3928 /*
3929 * Called from OPEN. Look for clientid in reclaim list.
3930 */
3931 __be32
3932 nfs4_check_open_reclaim(clientid_t *clid)
3933 {
3934 	return nfs4_find_reclaim_client(clid) ? nfs_ok : nfserr_reclaim_bad;
3935 }
3936 
3937 /* initialization to perform at module load time: */
3938 
3939 int
3940 nfs4_state_init(void)
3941 {
3942 	int i, status;
3943 
3944 	status = nfsd4_init_slabs();
3945 	if (status)
3946 		return status;
3947 	for (i = 0; i < CLIENT_HASH_SIZE; i++) {
3948 		INIT_LIST_HEAD(&conf_id_hashtbl[i]);
3949 		INIT_LIST_HEAD(&conf_str_hashtbl[i]);
3950 		INIT_LIST_HEAD(&unconf_str_hashtbl[i]);
3951 		INIT_LIST_HEAD(&unconf_id_hashtbl[i]);
3952 		INIT_LIST_HEAD(&reclaim_str_hashtbl[i]);
3953 	}
3954 	for (i = 0; i < SESSION_HASH_SIZE; i++)
3955 		INIT_LIST_HEAD(&sessionid_hashtbl[i]);
3956 	for (i = 0; i < FILE_HASH_SIZE; i++) {
3957 		INIT_LIST_HEAD(&file_hashtbl[i]);
3958 	}
3959 	for (i = 0; i < OWNER_HASH_SIZE; i++) {
3960 		INIT_LIST_HEAD(&ownerstr_hashtbl[i]);
3961 		INIT_LIST_HEAD(&ownerid_hashtbl[i]);
3962 	}
3963 	for (i = 0; i < STATEID_HASH_SIZE; i++) {
3964 		INIT_LIST_HEAD(&stateid_hashtbl[i]);
3965 		INIT_LIST_HEAD(&lockstateid_hashtbl[i]);
3966 	}
3967 	for (i = 0; i < LOCK_HASH_SIZE; i++) {
3968 		INIT_LIST_HEAD(&lock_ownerid_hashtbl[i]);
3969 		INIT_LIST_HEAD(&lock_ownerstr_hashtbl[i]);
3970 	}
3971 	memset(&onestateid, ~0, sizeof(stateid_t));
3972 	INIT_LIST_HEAD(&close_lru);
3973 	INIT_LIST_HEAD(&client_lru);
3974 	INIT_LIST_HEAD(&del_recall_lru);
3975 	reclaim_str_hashtbl_size = 0;
3976 	return 0;
3977 }
3978 
3979 static void
3980 nfsd4_load_reboot_recovery_data(void)
3981 {
3982 	int status;
3983 
3984 	nfs4_lock_state();
3985 	nfsd4_init_recdir(user_recovery_dirname);
3986 	status = nfsd4_recdir_load();
3987 	nfs4_unlock_state();
3988 	if (status)
3989 		printk("NFSD: Failure reading reboot recovery data\n");
3990 }
3991 
3992 unsigned long
3993 get_nfs4_grace_period(void)
3994 {
3995 	return max(user_lease_time, lease_time) * HZ;
3996 }
3997 
3998 /*
3999  * Since the lifetime of a delegation isn't limited to that of an open, a
4000  * client may quite reasonably hang on to a delegation as long as it has
4001  * the inode cached.  This becomes an obvious problem the first time a
4002  * client's inode cache approaches the size of the server's total memory.
4003  *
4004  * For now we avoid this problem by imposing a hard limit on the number
4005  * of delegations, which varies according to the server's memory size.
4006  */
4007 static void
4008 set_max_delegations(void)
4009 {
4010 	/*
4011 	 * Allow at most 4 delegations per megabyte of RAM.  Quick
4012 	 * estimates suggest that in the worst case (where every delegation
4013 	 * is for a different inode), a delegation could take about 1.5K,
4014 	 * giving a worst case usage of about 6% of memory.
4015 	 */
4016 	max_delegations = nr_free_buffer_pages() >> (20 - 2 - PAGE_SHIFT);
4017 }
4018 
4019 /* initialization to perform when the nfsd service is started: */
4020 
4021 static int
4022 __nfs4_state_start(void)
4023 {
4024 	unsigned long grace_time;
4025 
4026 	boot_time = get_seconds();
4027 	grace_time = get_nfs4_grace_period();
4028 	lease_time = user_lease_time;
4029 	locks_start_grace(&nfsd4_manager);
4030 	printk(KERN_INFO "NFSD: starting %ld-second grace period\n",
4031 	       grace_time/HZ);
4032 	laundry_wq = create_singlethread_workqueue("nfsd4");
4033 	if (laundry_wq == NULL)
4034 		return -ENOMEM;
4035 	queue_delayed_work(laundry_wq, &laundromat_work, grace_time);
4036 	set_max_delegations();
4037 	return set_callback_cred();
4038 }
4039 
4040 int
4041 nfs4_state_start(void)
4042 {
4043 	int ret;
4044 
4045 	if (nfs4_init)
4046 		return 0;
4047 	nfsd4_load_reboot_recovery_data();
4048 	ret = __nfs4_state_start();
4049 	if (ret)
4050 		return ret;
4051 	nfs4_init = 1;
4052 	return 0;
4053 }
4054 
4055 time_t
4056 nfs4_lease_time(void)
4057 {
4058 	return lease_time;
4059 }
4060 
4061 static void
4062 __nfs4_state_shutdown(void)
4063 {
4064 	int i;
4065 	struct nfs4_client *clp = NULL;
4066 	struct nfs4_delegation *dp = NULL;
4067 	struct list_head *pos, *next, reaplist;
4068 
4069 	for (i = 0; i < CLIENT_HASH_SIZE; i++) {
4070 		while (!list_empty(&conf_id_hashtbl[i])) {
4071 			clp = list_entry(conf_id_hashtbl[i].next, struct nfs4_client, cl_idhash);
4072 			expire_client(clp);
4073 		}
4074 		while (!list_empty(&unconf_str_hashtbl[i])) {
4075 			clp = list_entry(unconf_str_hashtbl[i].next, struct nfs4_client, cl_strhash);
4076 			expire_client(clp);
4077 		}
4078 	}
4079 	INIT_LIST_HEAD(&reaplist);
4080 	spin_lock(&recall_lock);
4081 	list_for_each_safe(pos, next, &del_recall_lru) {
4082 		dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru);
4083 		list_move(&dp->dl_recall_lru, &reaplist);
4084 	}
4085 	spin_unlock(&recall_lock);
4086 	list_for_each_safe(pos, next, &reaplist) {
4087 		dp = list_entry (pos, struct nfs4_delegation, dl_recall_lru);
4088 		list_del_init(&dp->dl_recall_lru);
4089 		unhash_delegation(dp);
4090 	}
4091 
4092 	nfsd4_shutdown_recdir();
4093 	nfs4_init = 0;
4094 }
4095 
4096 void
4097 nfs4_state_shutdown(void)
4098 {
4099 	cancel_rearming_delayed_workqueue(laundry_wq, &laundromat_work);
4100 	destroy_workqueue(laundry_wq);
4101 	locks_end_grace(&nfsd4_manager);
4102 	nfs4_lock_state();
4103 	nfs4_release_reclaim();
4104 	__nfs4_state_shutdown();
4105 	nfs4_unlock_state();
4106 }
4107 
4108 /*
4109  * user_recovery_dirname is protected by the nfsd_mutex since it's only
4110  * accessed when nfsd is starting.
4111  */
4112 static void
4113 nfs4_set_recdir(char *recdir)
4114 {
4115 	strcpy(user_recovery_dirname, recdir);
4116 }
4117 
4118 /*
4119  * Change the NFSv4 recovery directory to recdir.
4120  */
4121 int
4122 nfs4_reset_recoverydir(char *recdir)
4123 {
4124 	int status;
4125 	struct path path;
4126 
4127 	status = kern_path(recdir, LOOKUP_FOLLOW, &path);
4128 	if (status)
4129 		return status;
4130 	status = -ENOTDIR;
4131 	if (S_ISDIR(path.dentry->d_inode->i_mode)) {
4132 		nfs4_set_recdir(recdir);
4133 		status = 0;
4134 	}
4135 	path_put(&path);
4136 	return status;
4137 }
4138 
4139 char *
4140 nfs4_recoverydir(void)
4141 {
4142 	return user_recovery_dirname;
4143 }
4144 
4145 /*
4146  * Called when leasetime is changed.
4147  *
4148  * The only way the protocol gives us to handle on-the-fly lease changes is to
4149  * simulate a reboot.  Instead of doing that, we just wait till the next time
4150  * we start to register any changes in lease time.  If the administrator
4151  * really wants to change the lease time *now*, they can go ahead and bring
4152  * nfsd down and then back up again after changing the lease time.
4153  *
4154  * user_lease_time is protected by nfsd_mutex since it's only really accessed
4155  * when nfsd is starting
4156  */
4157 void
4158 nfs4_reset_lease(time_t leasetime)
4159 {
4160 	user_lease_time = leasetime;
4161 }
4162