xref: /linux/fs/nfs/nfs4state.c (revision 9ce7677cfd7cd871adb457c80bea3b581b839641)
1 /*
2  *  fs/nfs/nfs4state.c
3  *
4  *  Client-side XDR for NFSv4.
5  *
6  *  Copyright (c) 2002 The Regents of the University of Michigan.
7  *  All rights reserved.
8  *
9  *  Kendrick Smith <kmsmith@umich.edu>
10  *
11  *  Redistribution and use in source and binary forms, with or without
12  *  modification, are permitted provided that the following conditions
13  *  are met:
14  *
15  *  1. Redistributions of source code must retain the above copyright
16  *     notice, this list of conditions and the following disclaimer.
17  *  2. Redistributions in binary form must reproduce the above copyright
18  *     notice, this list of conditions and the following disclaimer in the
19  *     documentation and/or other materials provided with the distribution.
20  *  3. Neither the name of the University nor the names of its
21  *     contributors may be used to endorse or promote products derived
22  *     from this software without specific prior written permission.
23  *
24  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
25  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
26  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
27  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
31  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
32  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
33  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
34  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35  *
36  * Implementation of the NFSv4 state model.  For the time being,
37  * this is minimal, but will be made much more complex in a
38  * subsequent patch.
39  */
40 
41 #include <linux/config.h>
42 #include <linux/slab.h>
43 #include <linux/smp_lock.h>
44 #include <linux/nfs_fs.h>
45 #include <linux/nfs_idmap.h>
46 #include <linux/workqueue.h>
47 #include <linux/bitops.h>
48 
49 #include "nfs4_fs.h"
50 #include "callback.h"
51 #include "delegation.h"
52 
53 #define OPENOWNER_POOL_SIZE	8
54 
55 const nfs4_stateid zero_stateid;
56 
57 static DEFINE_SPINLOCK(state_spinlock);
58 static LIST_HEAD(nfs4_clientid_list);
59 
60 static void nfs4_recover_state(void *);
61 
62 void
63 init_nfsv4_state(struct nfs_server *server)
64 {
65 	server->nfs4_state = NULL;
66 	INIT_LIST_HEAD(&server->nfs4_siblings);
67 }
68 
69 void
70 destroy_nfsv4_state(struct nfs_server *server)
71 {
72 	kfree(server->mnt_path);
73 	server->mnt_path = NULL;
74 	if (server->nfs4_state) {
75 		nfs4_put_client(server->nfs4_state);
76 		server->nfs4_state = NULL;
77 	}
78 }
79 
80 /*
81  * nfs4_get_client(): returns an empty client structure
82  * nfs4_put_client(): drops reference to client structure
83  *
84  * Since these are allocated/deallocated very rarely, we don't
85  * bother putting them in a slab cache...
86  */
87 static struct nfs4_client *
88 nfs4_alloc_client(struct in_addr *addr)
89 {
90 	struct nfs4_client *clp;
91 
92 	if (nfs_callback_up() < 0)
93 		return NULL;
94 	if ((clp = kmalloc(sizeof(*clp), GFP_KERNEL)) == NULL) {
95 		nfs_callback_down();
96 		return NULL;
97 	}
98 	memset(clp, 0, sizeof(*clp));
99 	memcpy(&clp->cl_addr, addr, sizeof(clp->cl_addr));
100 	init_rwsem(&clp->cl_sem);
101 	INIT_LIST_HEAD(&clp->cl_delegations);
102 	INIT_LIST_HEAD(&clp->cl_state_owners);
103 	INIT_LIST_HEAD(&clp->cl_unused);
104 	spin_lock_init(&clp->cl_lock);
105 	atomic_set(&clp->cl_count, 1);
106 	INIT_WORK(&clp->cl_recoverd, nfs4_recover_state, clp);
107 	INIT_WORK(&clp->cl_renewd, nfs4_renew_state, clp);
108 	INIT_LIST_HEAD(&clp->cl_superblocks);
109 	init_waitqueue_head(&clp->cl_waitq);
110 	rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS4 client");
111 	clp->cl_rpcclient = ERR_PTR(-EINVAL);
112 	clp->cl_boot_time = CURRENT_TIME;
113 	clp->cl_state = 1 << NFS4CLNT_OK;
114 	return clp;
115 }
116 
117 static void
118 nfs4_free_client(struct nfs4_client *clp)
119 {
120 	struct nfs4_state_owner *sp;
121 
122 	while (!list_empty(&clp->cl_unused)) {
123 		sp = list_entry(clp->cl_unused.next,
124 				struct nfs4_state_owner,
125 				so_list);
126 		list_del(&sp->so_list);
127 		kfree(sp);
128 	}
129 	BUG_ON(!list_empty(&clp->cl_state_owners));
130 	if (clp->cl_cred)
131 		put_rpccred(clp->cl_cred);
132 	nfs_idmap_delete(clp);
133 	if (!IS_ERR(clp->cl_rpcclient))
134 		rpc_shutdown_client(clp->cl_rpcclient);
135 	kfree(clp);
136 	nfs_callback_down();
137 }
138 
139 static struct nfs4_client *__nfs4_find_client(struct in_addr *addr)
140 {
141 	struct nfs4_client *clp;
142 	list_for_each_entry(clp, &nfs4_clientid_list, cl_servers) {
143 		if (memcmp(&clp->cl_addr, addr, sizeof(clp->cl_addr)) == 0) {
144 			atomic_inc(&clp->cl_count);
145 			return clp;
146 		}
147 	}
148 	return NULL;
149 }
150 
151 struct nfs4_client *nfs4_find_client(struct in_addr *addr)
152 {
153 	struct nfs4_client *clp;
154 	spin_lock(&state_spinlock);
155 	clp = __nfs4_find_client(addr);
156 	spin_unlock(&state_spinlock);
157 	return clp;
158 }
159 
160 struct nfs4_client *
161 nfs4_get_client(struct in_addr *addr)
162 {
163 	struct nfs4_client *clp, *new = NULL;
164 
165 	spin_lock(&state_spinlock);
166 	for (;;) {
167 		clp = __nfs4_find_client(addr);
168 		if (clp != NULL)
169 			break;
170 		clp = new;
171 		if (clp != NULL) {
172 			list_add(&clp->cl_servers, &nfs4_clientid_list);
173 			new = NULL;
174 			break;
175 		}
176 		spin_unlock(&state_spinlock);
177 		new = nfs4_alloc_client(addr);
178 		spin_lock(&state_spinlock);
179 		if (new == NULL)
180 			break;
181 	}
182 	spin_unlock(&state_spinlock);
183 	if (new)
184 		nfs4_free_client(new);
185 	return clp;
186 }
187 
188 void
189 nfs4_put_client(struct nfs4_client *clp)
190 {
191 	if (!atomic_dec_and_lock(&clp->cl_count, &state_spinlock))
192 		return;
193 	list_del(&clp->cl_servers);
194 	spin_unlock(&state_spinlock);
195 	BUG_ON(!list_empty(&clp->cl_superblocks));
196 	wake_up_all(&clp->cl_waitq);
197 	rpc_wake_up(&clp->cl_rpcwaitq);
198 	nfs4_kill_renewd(clp);
199 	nfs4_free_client(clp);
200 }
201 
202 static int __nfs4_init_client(struct nfs4_client *clp)
203 {
204 	int status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, nfs_callback_tcpport);
205 	if (status == 0)
206 		status = nfs4_proc_setclientid_confirm(clp);
207 	if (status == 0)
208 		nfs4_schedule_state_renewal(clp);
209 	return status;
210 }
211 
212 int nfs4_init_client(struct nfs4_client *clp)
213 {
214 	return nfs4_map_errors(__nfs4_init_client(clp));
215 }
216 
217 u32
218 nfs4_alloc_lockowner_id(struct nfs4_client *clp)
219 {
220 	return clp->cl_lockowner_id ++;
221 }
222 
223 static struct nfs4_state_owner *
224 nfs4_client_grab_unused(struct nfs4_client *clp, struct rpc_cred *cred)
225 {
226 	struct nfs4_state_owner *sp = NULL;
227 
228 	if (!list_empty(&clp->cl_unused)) {
229 		sp = list_entry(clp->cl_unused.next, struct nfs4_state_owner, so_list);
230 		atomic_inc(&sp->so_count);
231 		sp->so_cred = cred;
232 		list_move(&sp->so_list, &clp->cl_state_owners);
233 		clp->cl_nunused--;
234 	}
235 	return sp;
236 }
237 
238 static struct nfs4_state_owner *
239 nfs4_find_state_owner(struct nfs4_client *clp, struct rpc_cred *cred)
240 {
241 	struct nfs4_state_owner *sp, *res = NULL;
242 
243 	list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
244 		if (sp->so_cred != cred)
245 			continue;
246 		atomic_inc(&sp->so_count);
247 		/* Move to the head of the list */
248 		list_move(&sp->so_list, &clp->cl_state_owners);
249 		res = sp;
250 		break;
251 	}
252 	return res;
253 }
254 
255 /*
256  * nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
257  * create a new state_owner.
258  *
259  */
260 static struct nfs4_state_owner *
261 nfs4_alloc_state_owner(void)
262 {
263 	struct nfs4_state_owner *sp;
264 
265 	sp = kzalloc(sizeof(*sp),GFP_KERNEL);
266 	if (!sp)
267 		return NULL;
268 	spin_lock_init(&sp->so_lock);
269 	INIT_LIST_HEAD(&sp->so_states);
270 	INIT_LIST_HEAD(&sp->so_delegations);
271 	rpc_init_wait_queue(&sp->so_sequence.wait, "Seqid_waitqueue");
272 	sp->so_seqid.sequence = &sp->so_sequence;
273 	spin_lock_init(&sp->so_sequence.lock);
274 	INIT_LIST_HEAD(&sp->so_sequence.list);
275 	atomic_set(&sp->so_count, 1);
276 	return sp;
277 }
278 
279 void
280 nfs4_drop_state_owner(struct nfs4_state_owner *sp)
281 {
282 	struct nfs4_client *clp = sp->so_client;
283 	spin_lock(&clp->cl_lock);
284 	list_del_init(&sp->so_list);
285 	spin_unlock(&clp->cl_lock);
286 }
287 
288 /*
289  * Note: must be called with clp->cl_sem held in order to prevent races
290  *       with reboot recovery!
291  */
292 struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server, struct rpc_cred *cred)
293 {
294 	struct nfs4_client *clp = server->nfs4_state;
295 	struct nfs4_state_owner *sp, *new;
296 
297 	get_rpccred(cred);
298 	new = nfs4_alloc_state_owner();
299 	spin_lock(&clp->cl_lock);
300 	sp = nfs4_find_state_owner(clp, cred);
301 	if (sp == NULL)
302 		sp = nfs4_client_grab_unused(clp, cred);
303 	if (sp == NULL && new != NULL) {
304 		list_add(&new->so_list, &clp->cl_state_owners);
305 		new->so_client = clp;
306 		new->so_id = nfs4_alloc_lockowner_id(clp);
307 		new->so_cred = cred;
308 		sp = new;
309 		new = NULL;
310 	}
311 	spin_unlock(&clp->cl_lock);
312 	kfree(new);
313 	if (sp != NULL)
314 		return sp;
315 	put_rpccred(cred);
316 	return NULL;
317 }
318 
319 /*
320  * Must be called with clp->cl_sem held in order to avoid races
321  * with state recovery...
322  */
323 void nfs4_put_state_owner(struct nfs4_state_owner *sp)
324 {
325 	struct nfs4_client *clp = sp->so_client;
326 	struct rpc_cred *cred = sp->so_cred;
327 
328 	if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
329 		return;
330 	if (clp->cl_nunused >= OPENOWNER_POOL_SIZE)
331 		goto out_free;
332 	if (list_empty(&sp->so_list))
333 		goto out_free;
334 	list_move(&sp->so_list, &clp->cl_unused);
335 	clp->cl_nunused++;
336 	spin_unlock(&clp->cl_lock);
337 	put_rpccred(cred);
338 	cred = NULL;
339 	return;
340 out_free:
341 	list_del(&sp->so_list);
342 	spin_unlock(&clp->cl_lock);
343 	put_rpccred(cred);
344 	kfree(sp);
345 }
346 
347 static struct nfs4_state *
348 nfs4_alloc_open_state(void)
349 {
350 	struct nfs4_state *state;
351 
352 	state = kmalloc(sizeof(*state), GFP_KERNEL);
353 	if (!state)
354 		return NULL;
355 	state->state = 0;
356 	state->nreaders = 0;
357 	state->nwriters = 0;
358 	state->flags = 0;
359 	memset(state->stateid.data, 0, sizeof(state->stateid.data));
360 	atomic_set(&state->count, 1);
361 	INIT_LIST_HEAD(&state->lock_states);
362 	spin_lock_init(&state->state_lock);
363 	return state;
364 }
365 
366 void
367 nfs4_state_set_mode_locked(struct nfs4_state *state, mode_t mode)
368 {
369 	if (state->state == mode)
370 		return;
371 	/* NB! List reordering - see the reclaim code for why.  */
372 	if ((mode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
373 		if (mode & FMODE_WRITE)
374 			list_move(&state->open_states, &state->owner->so_states);
375 		else
376 			list_move_tail(&state->open_states, &state->owner->so_states);
377 	}
378 	if (mode == 0)
379 		list_del_init(&state->inode_states);
380 	state->state = mode;
381 }
382 
383 static struct nfs4_state *
384 __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
385 {
386 	struct nfs_inode *nfsi = NFS_I(inode);
387 	struct nfs4_state *state;
388 
389 	list_for_each_entry(state, &nfsi->open_states, inode_states) {
390 		/* Is this in the process of being freed? */
391 		if (state->state == 0)
392 			continue;
393 		if (state->owner == owner) {
394 			atomic_inc(&state->count);
395 			return state;
396 		}
397 	}
398 	return NULL;
399 }
400 
401 static void
402 nfs4_free_open_state(struct nfs4_state *state)
403 {
404 	kfree(state);
405 }
406 
407 struct nfs4_state *
408 nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
409 {
410 	struct nfs4_state *state, *new;
411 	struct nfs_inode *nfsi = NFS_I(inode);
412 
413 	spin_lock(&inode->i_lock);
414 	state = __nfs4_find_state_byowner(inode, owner);
415 	spin_unlock(&inode->i_lock);
416 	if (state)
417 		goto out;
418 	new = nfs4_alloc_open_state();
419 	spin_lock(&owner->so_lock);
420 	spin_lock(&inode->i_lock);
421 	state = __nfs4_find_state_byowner(inode, owner);
422 	if (state == NULL && new != NULL) {
423 		state = new;
424 		state->owner = owner;
425 		atomic_inc(&owner->so_count);
426 		list_add(&state->inode_states, &nfsi->open_states);
427 		state->inode = igrab(inode);
428 		spin_unlock(&inode->i_lock);
429 		/* Note: The reclaim code dictates that we add stateless
430 		 * and read-only stateids to the end of the list */
431 		list_add_tail(&state->open_states, &owner->so_states);
432 		spin_unlock(&owner->so_lock);
433 	} else {
434 		spin_unlock(&inode->i_lock);
435 		spin_unlock(&owner->so_lock);
436 		if (new)
437 			nfs4_free_open_state(new);
438 	}
439 out:
440 	return state;
441 }
442 
443 /*
444  * Beware! Caller must be holding exactly one
445  * reference to clp->cl_sem!
446  */
447 void nfs4_put_open_state(struct nfs4_state *state)
448 {
449 	struct inode *inode = state->inode;
450 	struct nfs4_state_owner *owner = state->owner;
451 
452 	if (!atomic_dec_and_lock(&state->count, &owner->so_lock))
453 		return;
454 	spin_lock(&inode->i_lock);
455 	if (!list_empty(&state->inode_states))
456 		list_del(&state->inode_states);
457 	list_del(&state->open_states);
458 	spin_unlock(&inode->i_lock);
459 	spin_unlock(&owner->so_lock);
460 	iput(inode);
461 	nfs4_free_open_state(state);
462 	nfs4_put_state_owner(owner);
463 }
464 
465 /*
466  * Close the current file.
467  */
468 void nfs4_close_state(struct nfs4_state *state, mode_t mode)
469 {
470 	struct inode *inode = state->inode;
471 	struct nfs4_state_owner *owner = state->owner;
472 	int oldstate, newstate = 0;
473 
474 	atomic_inc(&owner->so_count);
475 	/* Protect against nfs4_find_state() */
476 	spin_lock(&owner->so_lock);
477 	spin_lock(&inode->i_lock);
478 	if (mode & FMODE_READ)
479 		state->nreaders--;
480 	if (mode & FMODE_WRITE)
481 		state->nwriters--;
482 	oldstate = newstate = state->state;
483 	if (state->nreaders == 0)
484 		newstate &= ~FMODE_READ;
485 	if (state->nwriters == 0)
486 		newstate &= ~FMODE_WRITE;
487 	if (test_bit(NFS_DELEGATED_STATE, &state->flags)) {
488 		nfs4_state_set_mode_locked(state, newstate);
489 		oldstate = newstate;
490 	}
491 	spin_unlock(&inode->i_lock);
492 	spin_unlock(&owner->so_lock);
493 
494 	if (oldstate != newstate && nfs4_do_close(inode, state) == 0)
495 		return;
496 	nfs4_put_open_state(state);
497 	nfs4_put_state_owner(owner);
498 }
499 
500 /*
501  * Search the state->lock_states for an existing lock_owner
502  * that is compatible with current->files
503  */
504 static struct nfs4_lock_state *
505 __nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
506 {
507 	struct nfs4_lock_state *pos;
508 	list_for_each_entry(pos, &state->lock_states, ls_locks) {
509 		if (pos->ls_owner != fl_owner)
510 			continue;
511 		atomic_inc(&pos->ls_count);
512 		return pos;
513 	}
514 	return NULL;
515 }
516 
517 /*
518  * Return a compatible lock_state. If no initialized lock_state structure
519  * exists, return an uninitialized one.
520  *
521  */
522 static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
523 {
524 	struct nfs4_lock_state *lsp;
525 	struct nfs4_client *clp = state->owner->so_client;
526 
527 	lsp = kzalloc(sizeof(*lsp), GFP_KERNEL);
528 	if (lsp == NULL)
529 		return NULL;
530 	lsp->ls_seqid.sequence = &state->owner->so_sequence;
531 	atomic_set(&lsp->ls_count, 1);
532 	lsp->ls_owner = fl_owner;
533 	spin_lock(&clp->cl_lock);
534 	lsp->ls_id = nfs4_alloc_lockowner_id(clp);
535 	spin_unlock(&clp->cl_lock);
536 	INIT_LIST_HEAD(&lsp->ls_locks);
537 	return lsp;
538 }
539 
540 /*
541  * Return a compatible lock_state. If no initialized lock_state structure
542  * exists, return an uninitialized one.
543  *
544  * The caller must be holding clp->cl_sem
545  */
546 static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
547 {
548 	struct nfs4_lock_state *lsp, *new = NULL;
549 
550 	for(;;) {
551 		spin_lock(&state->state_lock);
552 		lsp = __nfs4_find_lock_state(state, owner);
553 		if (lsp != NULL)
554 			break;
555 		if (new != NULL) {
556 			new->ls_state = state;
557 			list_add(&new->ls_locks, &state->lock_states);
558 			set_bit(LK_STATE_IN_USE, &state->flags);
559 			lsp = new;
560 			new = NULL;
561 			break;
562 		}
563 		spin_unlock(&state->state_lock);
564 		new = nfs4_alloc_lock_state(state, owner);
565 		if (new == NULL)
566 			return NULL;
567 	}
568 	spin_unlock(&state->state_lock);
569 	kfree(new);
570 	return lsp;
571 }
572 
573 /*
574  * Release reference to lock_state, and free it if we see that
575  * it is no longer in use
576  */
577 void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
578 {
579 	struct nfs4_state *state;
580 
581 	if (lsp == NULL)
582 		return;
583 	state = lsp->ls_state;
584 	if (!atomic_dec_and_lock(&lsp->ls_count, &state->state_lock))
585 		return;
586 	list_del(&lsp->ls_locks);
587 	if (list_empty(&state->lock_states))
588 		clear_bit(LK_STATE_IN_USE, &state->flags);
589 	spin_unlock(&state->state_lock);
590 	kfree(lsp);
591 }
592 
593 static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
594 {
595 	struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
596 
597 	dst->fl_u.nfs4_fl.owner = lsp;
598 	atomic_inc(&lsp->ls_count);
599 }
600 
601 static void nfs4_fl_release_lock(struct file_lock *fl)
602 {
603 	nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
604 }
605 
606 static struct file_lock_operations nfs4_fl_lock_ops = {
607 	.fl_copy_lock = nfs4_fl_copy_lock,
608 	.fl_release_private = nfs4_fl_release_lock,
609 };
610 
611 int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
612 {
613 	struct nfs4_lock_state *lsp;
614 
615 	if (fl->fl_ops != NULL)
616 		return 0;
617 	lsp = nfs4_get_lock_state(state, fl->fl_owner);
618 	if (lsp == NULL)
619 		return -ENOMEM;
620 	fl->fl_u.nfs4_fl.owner = lsp;
621 	fl->fl_ops = &nfs4_fl_lock_ops;
622 	return 0;
623 }
624 
625 /*
626  * Byte-range lock aware utility to initialize the stateid of read/write
627  * requests.
628  */
629 void nfs4_copy_stateid(nfs4_stateid *dst, struct nfs4_state *state, fl_owner_t fl_owner)
630 {
631 	struct nfs4_lock_state *lsp;
632 
633 	memcpy(dst, &state->stateid, sizeof(*dst));
634 	if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
635 		return;
636 
637 	spin_lock(&state->state_lock);
638 	lsp = __nfs4_find_lock_state(state, fl_owner);
639 	if (lsp != NULL && (lsp->ls_flags & NFS_LOCK_INITIALIZED) != 0)
640 		memcpy(dst, &lsp->ls_stateid, sizeof(*dst));
641 	spin_unlock(&state->state_lock);
642 	nfs4_put_lock_state(lsp);
643 }
644 
645 struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter)
646 {
647 	struct rpc_sequence *sequence = counter->sequence;
648 	struct nfs_seqid *new;
649 
650 	new = kmalloc(sizeof(*new), GFP_KERNEL);
651 	if (new != NULL) {
652 		new->sequence = counter;
653 		spin_lock(&sequence->lock);
654 		list_add_tail(&new->list, &sequence->list);
655 		spin_unlock(&sequence->lock);
656 	}
657 	return new;
658 }
659 
660 void nfs_free_seqid(struct nfs_seqid *seqid)
661 {
662 	struct rpc_sequence *sequence = seqid->sequence->sequence;
663 
664 	spin_lock(&sequence->lock);
665 	list_del(&seqid->list);
666 	spin_unlock(&sequence->lock);
667 	rpc_wake_up(&sequence->wait);
668 	kfree(seqid);
669 }
670 
671 /*
672  * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
673  * failed with a seqid incrementing error -
674  * see comments nfs_fs.h:seqid_mutating_error()
675  */
676 static inline void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
677 {
678 	switch (status) {
679 		case 0:
680 			break;
681 		case -NFS4ERR_BAD_SEQID:
682 		case -NFS4ERR_STALE_CLIENTID:
683 		case -NFS4ERR_STALE_STATEID:
684 		case -NFS4ERR_BAD_STATEID:
685 		case -NFS4ERR_BADXDR:
686 		case -NFS4ERR_RESOURCE:
687 		case -NFS4ERR_NOFILEHANDLE:
688 			/* Non-seqid mutating errors */
689 			return;
690 	};
691 	/*
692 	 * Note: no locking needed as we are guaranteed to be first
693 	 * on the sequence list
694 	 */
695 	seqid->sequence->counter++;
696 }
697 
698 void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
699 {
700 	if (status == -NFS4ERR_BAD_SEQID) {
701 		struct nfs4_state_owner *sp = container_of(seqid->sequence,
702 				struct nfs4_state_owner, so_seqid);
703 		nfs4_drop_state_owner(sp);
704 	}
705 	return nfs_increment_seqid(status, seqid);
706 }
707 
708 /*
709  * Increment the seqid if the LOCK/LOCKU succeeded, or
710  * failed with a seqid incrementing error -
711  * see comments nfs_fs.h:seqid_mutating_error()
712  */
713 void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
714 {
715 	return nfs_increment_seqid(status, seqid);
716 }
717 
718 int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
719 {
720 	struct rpc_sequence *sequence = seqid->sequence->sequence;
721 	int status = 0;
722 
723 	if (sequence->list.next == &seqid->list)
724 		goto out;
725 	spin_lock(&sequence->lock);
726 	if (sequence->list.next != &seqid->list) {
727 		rpc_sleep_on(&sequence->wait, task, NULL, NULL);
728 		status = -EAGAIN;
729 	}
730 	spin_unlock(&sequence->lock);
731 out:
732 	return status;
733 }
734 
735 static int reclaimer(void *);
736 struct reclaimer_args {
737 	struct nfs4_client *clp;
738 	struct completion complete;
739 };
740 
741 /*
742  * State recovery routine
743  */
744 void
745 nfs4_recover_state(void *data)
746 {
747 	struct nfs4_client *clp = (struct nfs4_client *)data;
748 	struct reclaimer_args args = {
749 		.clp = clp,
750 	};
751 	might_sleep();
752 
753 	init_completion(&args.complete);
754 
755 	if (kernel_thread(reclaimer, &args, CLONE_KERNEL) < 0)
756 		goto out_failed_clear;
757 	wait_for_completion(&args.complete);
758 	return;
759 out_failed_clear:
760 	set_bit(NFS4CLNT_OK, &clp->cl_state);
761 	wake_up_all(&clp->cl_waitq);
762 	rpc_wake_up(&clp->cl_rpcwaitq);
763 }
764 
765 /*
766  * Schedule a state recovery attempt
767  */
768 void
769 nfs4_schedule_state_recovery(struct nfs4_client *clp)
770 {
771 	if (!clp)
772 		return;
773 	if (test_and_clear_bit(NFS4CLNT_OK, &clp->cl_state))
774 		schedule_work(&clp->cl_recoverd);
775 }
776 
777 static int nfs4_reclaim_locks(struct nfs4_state_recovery_ops *ops, struct nfs4_state *state)
778 {
779 	struct inode *inode = state->inode;
780 	struct file_lock *fl;
781 	int status = 0;
782 
783 	for (fl = inode->i_flock; fl != 0; fl = fl->fl_next) {
784 		if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
785 			continue;
786 		if (((struct nfs_open_context *)fl->fl_file->private_data)->state != state)
787 			continue;
788 		status = ops->recover_lock(state, fl);
789 		if (status >= 0)
790 			continue;
791 		switch (status) {
792 			default:
793 				printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
794 						__FUNCTION__, status);
795 			case -NFS4ERR_EXPIRED:
796 			case -NFS4ERR_NO_GRACE:
797 			case -NFS4ERR_RECLAIM_BAD:
798 			case -NFS4ERR_RECLAIM_CONFLICT:
799 				/* kill_proc(fl->fl_pid, SIGLOST, 1); */
800 				break;
801 			case -NFS4ERR_STALE_CLIENTID:
802 				goto out_err;
803 		}
804 	}
805 	return 0;
806 out_err:
807 	return status;
808 }
809 
810 static int nfs4_reclaim_open_state(struct nfs4_state_recovery_ops *ops, struct nfs4_state_owner *sp)
811 {
812 	struct nfs4_state *state;
813 	struct nfs4_lock_state *lock;
814 	int status = 0;
815 
816 	/* Note: we rely on the sp->so_states list being ordered
817 	 * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
818 	 * states first.
819 	 * This is needed to ensure that the server won't give us any
820 	 * read delegations that we have to return if, say, we are
821 	 * recovering after a network partition or a reboot from a
822 	 * server that doesn't support a grace period.
823 	 */
824 	list_for_each_entry(state, &sp->so_states, open_states) {
825 		if (state->state == 0)
826 			continue;
827 		status = ops->recover_open(sp, state);
828 		if (status >= 0) {
829 			status = nfs4_reclaim_locks(ops, state);
830 			if (status < 0)
831 				goto out_err;
832 			list_for_each_entry(lock, &state->lock_states, ls_locks) {
833 				if (!(lock->ls_flags & NFS_LOCK_INITIALIZED))
834 					printk("%s: Lock reclaim failed!\n",
835 							__FUNCTION__);
836 			}
837 			continue;
838 		}
839 		switch (status) {
840 			default:
841 				printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
842 						__FUNCTION__, status);
843 			case -ENOENT:
844 			case -NFS4ERR_RECLAIM_BAD:
845 			case -NFS4ERR_RECLAIM_CONFLICT:
846 				/*
847 				 * Open state on this file cannot be recovered
848 				 * All we can do is revert to using the zero stateid.
849 				 */
850 				memset(state->stateid.data, 0,
851 					sizeof(state->stateid.data));
852 				/* Mark the file as being 'closed' */
853 				state->state = 0;
854 				break;
855 			case -NFS4ERR_EXPIRED:
856 			case -NFS4ERR_NO_GRACE:
857 			case -NFS4ERR_STALE_CLIENTID:
858 				goto out_err;
859 		}
860 	}
861 	return 0;
862 out_err:
863 	return status;
864 }
865 
866 static void nfs4_state_mark_reclaim(struct nfs4_client *clp)
867 {
868 	struct nfs4_state_owner *sp;
869 	struct nfs4_state *state;
870 	struct nfs4_lock_state *lock;
871 
872 	/* Reset all sequence ids to zero */
873 	list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
874 		sp->so_seqid.counter = 0;
875 		sp->so_seqid.flags = 0;
876 		spin_lock(&sp->so_lock);
877 		list_for_each_entry(state, &sp->so_states, open_states) {
878 			list_for_each_entry(lock, &state->lock_states, ls_locks) {
879 				lock->ls_seqid.counter = 0;
880 				lock->ls_seqid.flags = 0;
881 				lock->ls_flags &= ~NFS_LOCK_INITIALIZED;
882 			}
883 		}
884 		spin_unlock(&sp->so_lock);
885 	}
886 }
887 
888 static int reclaimer(void *ptr)
889 {
890 	struct reclaimer_args *args = (struct reclaimer_args *)ptr;
891 	struct nfs4_client *clp = args->clp;
892 	struct nfs4_state_owner *sp;
893 	struct nfs4_state_recovery_ops *ops;
894 	int status = 0;
895 
896 	daemonize("%u.%u.%u.%u-reclaim", NIPQUAD(clp->cl_addr));
897 	allow_signal(SIGKILL);
898 
899 	atomic_inc(&clp->cl_count);
900 	complete(&args->complete);
901 
902 	/* Ensure exclusive access to NFSv4 state */
903 	lock_kernel();
904 	down_write(&clp->cl_sem);
905 	/* Are there any NFS mounts out there? */
906 	if (list_empty(&clp->cl_superblocks))
907 		goto out;
908 restart_loop:
909 	status = nfs4_proc_renew(clp);
910 	switch (status) {
911 		case 0:
912 		case -NFS4ERR_CB_PATH_DOWN:
913 			goto out;
914 		case -NFS4ERR_STALE_CLIENTID:
915 		case -NFS4ERR_LEASE_MOVED:
916 			ops = &nfs4_reboot_recovery_ops;
917 			break;
918 		default:
919 			ops = &nfs4_network_partition_recovery_ops;
920 	};
921 	nfs4_state_mark_reclaim(clp);
922 	status = __nfs4_init_client(clp);
923 	if (status)
924 		goto out_error;
925 	/* Mark all delegations for reclaim */
926 	nfs_delegation_mark_reclaim(clp);
927 	/* Note: list is protected by exclusive lock on cl->cl_sem */
928 	list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
929 		status = nfs4_reclaim_open_state(ops, sp);
930 		if (status < 0) {
931 			if (status == -NFS4ERR_NO_GRACE) {
932 				ops = &nfs4_network_partition_recovery_ops;
933 				status = nfs4_reclaim_open_state(ops, sp);
934 			}
935 			if (status == -NFS4ERR_STALE_CLIENTID)
936 				goto restart_loop;
937 			if (status == -NFS4ERR_EXPIRED)
938 				goto restart_loop;
939 		}
940 	}
941 	nfs_delegation_reap_unclaimed(clp);
942 out:
943 	set_bit(NFS4CLNT_OK, &clp->cl_state);
944 	up_write(&clp->cl_sem);
945 	unlock_kernel();
946 	wake_up_all(&clp->cl_waitq);
947 	rpc_wake_up(&clp->cl_rpcwaitq);
948 	if (status == -NFS4ERR_CB_PATH_DOWN)
949 		nfs_handle_cb_pathdown(clp);
950 	nfs4_put_client(clp);
951 	return 0;
952 out_error:
953 	printk(KERN_WARNING "Error: state recovery failed on NFSv4 server %u.%u.%u.%u with error %d\n",
954 				NIPQUAD(clp->cl_addr.s_addr), -status);
955 	goto out;
956 }
957 
958 /*
959  * Local variables:
960  *  c-basic-offset: 8
961  * End:
962  */
963