xref: /linux/fs/nfs/nfs4state.c (revision 858259cf7d1c443c836a2022b78cb281f0a9b95e)
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 	if (server->mnt_path) {
73 		kfree(server->mnt_path);
74 		server->mnt_path = NULL;
75 	}
76 	if (server->nfs4_state) {
77 		nfs4_put_client(server->nfs4_state);
78 		server->nfs4_state = NULL;
79 	}
80 }
81 
82 /*
83  * nfs4_get_client(): returns an empty client structure
84  * nfs4_put_client(): drops reference to client structure
85  *
86  * Since these are allocated/deallocated very rarely, we don't
87  * bother putting them in a slab cache...
88  */
89 static struct nfs4_client *
90 nfs4_alloc_client(struct in_addr *addr)
91 {
92 	struct nfs4_client *clp;
93 
94 	if (nfs_callback_up() < 0)
95 		return NULL;
96 	if ((clp = kmalloc(sizeof(*clp), GFP_KERNEL)) == NULL) {
97 		nfs_callback_down();
98 		return NULL;
99 	}
100 	memset(clp, 0, sizeof(*clp));
101 	memcpy(&clp->cl_addr, addr, sizeof(clp->cl_addr));
102 	init_rwsem(&clp->cl_sem);
103 	INIT_LIST_HEAD(&clp->cl_delegations);
104 	INIT_LIST_HEAD(&clp->cl_state_owners);
105 	INIT_LIST_HEAD(&clp->cl_unused);
106 	spin_lock_init(&clp->cl_lock);
107 	atomic_set(&clp->cl_count, 1);
108 	INIT_WORK(&clp->cl_recoverd, nfs4_recover_state, clp);
109 	INIT_WORK(&clp->cl_renewd, nfs4_renew_state, clp);
110 	INIT_LIST_HEAD(&clp->cl_superblocks);
111 	init_waitqueue_head(&clp->cl_waitq);
112 	rpc_init_wait_queue(&clp->cl_rpcwaitq, "NFS4 client");
113 	clp->cl_rpcclient = ERR_PTR(-EINVAL);
114 	clp->cl_boot_time = CURRENT_TIME;
115 	clp->cl_state = 1 << NFS4CLNT_OK;
116 	return clp;
117 }
118 
119 static void
120 nfs4_free_client(struct nfs4_client *clp)
121 {
122 	struct nfs4_state_owner *sp;
123 
124 	while (!list_empty(&clp->cl_unused)) {
125 		sp = list_entry(clp->cl_unused.next,
126 				struct nfs4_state_owner,
127 				so_list);
128 		list_del(&sp->so_list);
129 		kfree(sp);
130 	}
131 	BUG_ON(!list_empty(&clp->cl_state_owners));
132 	if (clp->cl_cred)
133 		put_rpccred(clp->cl_cred);
134 	nfs_idmap_delete(clp);
135 	if (!IS_ERR(clp->cl_rpcclient))
136 		rpc_shutdown_client(clp->cl_rpcclient);
137 	kfree(clp);
138 	nfs_callback_down();
139 }
140 
141 static struct nfs4_client *__nfs4_find_client(struct in_addr *addr)
142 {
143 	struct nfs4_client *clp;
144 	list_for_each_entry(clp, &nfs4_clientid_list, cl_servers) {
145 		if (memcmp(&clp->cl_addr, addr, sizeof(clp->cl_addr)) == 0) {
146 			atomic_inc(&clp->cl_count);
147 			return clp;
148 		}
149 	}
150 	return NULL;
151 }
152 
153 struct nfs4_client *nfs4_find_client(struct in_addr *addr)
154 {
155 	struct nfs4_client *clp;
156 	spin_lock(&state_spinlock);
157 	clp = __nfs4_find_client(addr);
158 	spin_unlock(&state_spinlock);
159 	return clp;
160 }
161 
162 struct nfs4_client *
163 nfs4_get_client(struct in_addr *addr)
164 {
165 	struct nfs4_client *clp, *new = NULL;
166 
167 	spin_lock(&state_spinlock);
168 	for (;;) {
169 		clp = __nfs4_find_client(addr);
170 		if (clp != NULL)
171 			break;
172 		clp = new;
173 		if (clp != NULL) {
174 			list_add(&clp->cl_servers, &nfs4_clientid_list);
175 			new = NULL;
176 			break;
177 		}
178 		spin_unlock(&state_spinlock);
179 		new = nfs4_alloc_client(addr);
180 		spin_lock(&state_spinlock);
181 		if (new == NULL)
182 			break;
183 	}
184 	spin_unlock(&state_spinlock);
185 	if (new)
186 		nfs4_free_client(new);
187 	return clp;
188 }
189 
190 void
191 nfs4_put_client(struct nfs4_client *clp)
192 {
193 	if (!atomic_dec_and_lock(&clp->cl_count, &state_spinlock))
194 		return;
195 	list_del(&clp->cl_servers);
196 	spin_unlock(&state_spinlock);
197 	BUG_ON(!list_empty(&clp->cl_superblocks));
198 	wake_up_all(&clp->cl_waitq);
199 	rpc_wake_up(&clp->cl_rpcwaitq);
200 	nfs4_kill_renewd(clp);
201 	nfs4_free_client(clp);
202 }
203 
204 static int __nfs4_init_client(struct nfs4_client *clp)
205 {
206 	int status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, nfs_callback_tcpport);
207 	if (status == 0)
208 		status = nfs4_proc_setclientid_confirm(clp);
209 	if (status == 0)
210 		nfs4_schedule_state_renewal(clp);
211 	return status;
212 }
213 
214 int nfs4_init_client(struct nfs4_client *clp)
215 {
216 	return nfs4_map_errors(__nfs4_init_client(clp));
217 }
218 
219 u32
220 nfs4_alloc_lockowner_id(struct nfs4_client *clp)
221 {
222 	return clp->cl_lockowner_id ++;
223 }
224 
225 static struct nfs4_state_owner *
226 nfs4_client_grab_unused(struct nfs4_client *clp, struct rpc_cred *cred)
227 {
228 	struct nfs4_state_owner *sp = NULL;
229 
230 	if (!list_empty(&clp->cl_unused)) {
231 		sp = list_entry(clp->cl_unused.next, struct nfs4_state_owner, so_list);
232 		atomic_inc(&sp->so_count);
233 		sp->so_cred = cred;
234 		list_move(&sp->so_list, &clp->cl_state_owners);
235 		clp->cl_nunused--;
236 	}
237 	return sp;
238 }
239 
240 static struct nfs4_state_owner *
241 nfs4_find_state_owner(struct nfs4_client *clp, struct rpc_cred *cred)
242 {
243 	struct nfs4_state_owner *sp, *res = NULL;
244 
245 	list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
246 		if (sp->so_cred != cred)
247 			continue;
248 		atomic_inc(&sp->so_count);
249 		/* Move to the head of the list */
250 		list_move(&sp->so_list, &clp->cl_state_owners);
251 		res = sp;
252 		break;
253 	}
254 	return res;
255 }
256 
257 /*
258  * nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
259  * create a new state_owner.
260  *
261  */
262 static struct nfs4_state_owner *
263 nfs4_alloc_state_owner(void)
264 {
265 	struct nfs4_state_owner *sp;
266 
267 	sp = kzalloc(sizeof(*sp),GFP_KERNEL);
268 	if (!sp)
269 		return NULL;
270 	spin_lock_init(&sp->so_lock);
271 	INIT_LIST_HEAD(&sp->so_states);
272 	INIT_LIST_HEAD(&sp->so_delegations);
273 	rpc_init_wait_queue(&sp->so_sequence.wait, "Seqid_waitqueue");
274 	sp->so_seqid.sequence = &sp->so_sequence;
275 	spin_lock_init(&sp->so_sequence.lock);
276 	INIT_LIST_HEAD(&sp->so_sequence.list);
277 	atomic_set(&sp->so_count, 1);
278 	return sp;
279 }
280 
281 void
282 nfs4_drop_state_owner(struct nfs4_state_owner *sp)
283 {
284 	struct nfs4_client *clp = sp->so_client;
285 	spin_lock(&clp->cl_lock);
286 	list_del_init(&sp->so_list);
287 	spin_unlock(&clp->cl_lock);
288 }
289 
290 /*
291  * Note: must be called with clp->cl_sem held in order to prevent races
292  *       with reboot recovery!
293  */
294 struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server, struct rpc_cred *cred)
295 {
296 	struct nfs4_client *clp = server->nfs4_state;
297 	struct nfs4_state_owner *sp, *new;
298 
299 	get_rpccred(cred);
300 	new = nfs4_alloc_state_owner();
301 	spin_lock(&clp->cl_lock);
302 	sp = nfs4_find_state_owner(clp, cred);
303 	if (sp == NULL)
304 		sp = nfs4_client_grab_unused(clp, cred);
305 	if (sp == NULL && new != NULL) {
306 		list_add(&new->so_list, &clp->cl_state_owners);
307 		new->so_client = clp;
308 		new->so_id = nfs4_alloc_lockowner_id(clp);
309 		new->so_cred = cred;
310 		sp = new;
311 		new = NULL;
312 	}
313 	spin_unlock(&clp->cl_lock);
314 	if (new)
315 		kfree(new);
316 	if (sp != NULL)
317 		return sp;
318 	put_rpccred(cred);
319 	return NULL;
320 }
321 
322 /*
323  * Must be called with clp->cl_sem held in order to avoid races
324  * with state recovery...
325  */
326 void nfs4_put_state_owner(struct nfs4_state_owner *sp)
327 {
328 	struct nfs4_client *clp = sp->so_client;
329 	struct rpc_cred *cred = sp->so_cred;
330 
331 	if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
332 		return;
333 	if (clp->cl_nunused >= OPENOWNER_POOL_SIZE)
334 		goto out_free;
335 	if (list_empty(&sp->so_list))
336 		goto out_free;
337 	list_move(&sp->so_list, &clp->cl_unused);
338 	clp->cl_nunused++;
339 	spin_unlock(&clp->cl_lock);
340 	put_rpccred(cred);
341 	cred = NULL;
342 	return;
343 out_free:
344 	list_del(&sp->so_list);
345 	spin_unlock(&clp->cl_lock);
346 	put_rpccred(cred);
347 	kfree(sp);
348 }
349 
350 static struct nfs4_state *
351 nfs4_alloc_open_state(void)
352 {
353 	struct nfs4_state *state;
354 
355 	state = kmalloc(sizeof(*state), GFP_KERNEL);
356 	if (!state)
357 		return NULL;
358 	state->state = 0;
359 	state->nreaders = 0;
360 	state->nwriters = 0;
361 	state->flags = 0;
362 	memset(state->stateid.data, 0, sizeof(state->stateid.data));
363 	atomic_set(&state->count, 1);
364 	INIT_LIST_HEAD(&state->lock_states);
365 	spin_lock_init(&state->state_lock);
366 	return state;
367 }
368 
369 void
370 nfs4_state_set_mode_locked(struct nfs4_state *state, mode_t mode)
371 {
372 	if (state->state == mode)
373 		return;
374 	/* NB! List reordering - see the reclaim code for why.  */
375 	if ((mode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
376 		if (mode & FMODE_WRITE)
377 			list_move(&state->open_states, &state->owner->so_states);
378 		else
379 			list_move_tail(&state->open_states, &state->owner->so_states);
380 	}
381 	if (mode == 0)
382 		list_del_init(&state->inode_states);
383 	state->state = mode;
384 }
385 
386 static struct nfs4_state *
387 __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
388 {
389 	struct nfs_inode *nfsi = NFS_I(inode);
390 	struct nfs4_state *state;
391 
392 	list_for_each_entry(state, &nfsi->open_states, inode_states) {
393 		/* Is this in the process of being freed? */
394 		if (state->state == 0)
395 			continue;
396 		if (state->owner == owner) {
397 			atomic_inc(&state->count);
398 			return state;
399 		}
400 	}
401 	return NULL;
402 }
403 
404 static void
405 nfs4_free_open_state(struct nfs4_state *state)
406 {
407 	kfree(state);
408 }
409 
410 struct nfs4_state *
411 nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
412 {
413 	struct nfs4_state *state, *new;
414 	struct nfs_inode *nfsi = NFS_I(inode);
415 
416 	spin_lock(&inode->i_lock);
417 	state = __nfs4_find_state_byowner(inode, owner);
418 	spin_unlock(&inode->i_lock);
419 	if (state)
420 		goto out;
421 	new = nfs4_alloc_open_state();
422 	spin_lock(&owner->so_lock);
423 	spin_lock(&inode->i_lock);
424 	state = __nfs4_find_state_byowner(inode, owner);
425 	if (state == NULL && new != NULL) {
426 		state = new;
427 		state->owner = owner;
428 		atomic_inc(&owner->so_count);
429 		list_add(&state->inode_states, &nfsi->open_states);
430 		state->inode = igrab(inode);
431 		spin_unlock(&inode->i_lock);
432 		/* Note: The reclaim code dictates that we add stateless
433 		 * and read-only stateids to the end of the list */
434 		list_add_tail(&state->open_states, &owner->so_states);
435 		spin_unlock(&owner->so_lock);
436 	} else {
437 		spin_unlock(&inode->i_lock);
438 		spin_unlock(&owner->so_lock);
439 		if (new)
440 			nfs4_free_open_state(new);
441 	}
442 out:
443 	return state;
444 }
445 
446 /*
447  * Beware! Caller must be holding exactly one
448  * reference to clp->cl_sem!
449  */
450 void nfs4_put_open_state(struct nfs4_state *state)
451 {
452 	struct inode *inode = state->inode;
453 	struct nfs4_state_owner *owner = state->owner;
454 
455 	if (!atomic_dec_and_lock(&state->count, &owner->so_lock))
456 		return;
457 	spin_lock(&inode->i_lock);
458 	if (!list_empty(&state->inode_states))
459 		list_del(&state->inode_states);
460 	list_del(&state->open_states);
461 	spin_unlock(&inode->i_lock);
462 	spin_unlock(&owner->so_lock);
463 	iput(inode);
464 	nfs4_free_open_state(state);
465 	nfs4_put_state_owner(owner);
466 }
467 
468 /*
469  * Close the current file.
470  */
471 void nfs4_close_state(struct nfs4_state *state, mode_t mode)
472 {
473 	struct inode *inode = state->inode;
474 	struct nfs4_state_owner *owner = state->owner;
475 	int oldstate, newstate = 0;
476 
477 	atomic_inc(&owner->so_count);
478 	/* Protect against nfs4_find_state() */
479 	spin_lock(&owner->so_lock);
480 	spin_lock(&inode->i_lock);
481 	if (mode & FMODE_READ)
482 		state->nreaders--;
483 	if (mode & FMODE_WRITE)
484 		state->nwriters--;
485 	oldstate = newstate = state->state;
486 	if (state->nreaders == 0)
487 		newstate &= ~FMODE_READ;
488 	if (state->nwriters == 0)
489 		newstate &= ~FMODE_WRITE;
490 	if (test_bit(NFS_DELEGATED_STATE, &state->flags)) {
491 		nfs4_state_set_mode_locked(state, newstate);
492 		oldstate = newstate;
493 	}
494 	spin_unlock(&inode->i_lock);
495 	spin_unlock(&owner->so_lock);
496 
497 	if (oldstate != newstate && nfs4_do_close(inode, state) == 0)
498 		return;
499 	nfs4_put_open_state(state);
500 	nfs4_put_state_owner(owner);
501 }
502 
503 /*
504  * Search the state->lock_states for an existing lock_owner
505  * that is compatible with current->files
506  */
507 static struct nfs4_lock_state *
508 __nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
509 {
510 	struct nfs4_lock_state *pos;
511 	list_for_each_entry(pos, &state->lock_states, ls_locks) {
512 		if (pos->ls_owner != fl_owner)
513 			continue;
514 		atomic_inc(&pos->ls_count);
515 		return pos;
516 	}
517 	return NULL;
518 }
519 
520 /*
521  * Return a compatible lock_state. If no initialized lock_state structure
522  * exists, return an uninitialized one.
523  *
524  */
525 static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
526 {
527 	struct nfs4_lock_state *lsp;
528 	struct nfs4_client *clp = state->owner->so_client;
529 
530 	lsp = kzalloc(sizeof(*lsp), GFP_KERNEL);
531 	if (lsp == NULL)
532 		return NULL;
533 	lsp->ls_seqid.sequence = &state->owner->so_sequence;
534 	atomic_set(&lsp->ls_count, 1);
535 	lsp->ls_owner = fl_owner;
536 	spin_lock(&clp->cl_lock);
537 	lsp->ls_id = nfs4_alloc_lockowner_id(clp);
538 	spin_unlock(&clp->cl_lock);
539 	INIT_LIST_HEAD(&lsp->ls_locks);
540 	return lsp;
541 }
542 
543 /*
544  * Return a compatible lock_state. If no initialized lock_state structure
545  * exists, return an uninitialized one.
546  *
547  * The caller must be holding clp->cl_sem
548  */
549 static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
550 {
551 	struct nfs4_lock_state *lsp, *new = NULL;
552 
553 	for(;;) {
554 		spin_lock(&state->state_lock);
555 		lsp = __nfs4_find_lock_state(state, owner);
556 		if (lsp != NULL)
557 			break;
558 		if (new != NULL) {
559 			new->ls_state = state;
560 			list_add(&new->ls_locks, &state->lock_states);
561 			set_bit(LK_STATE_IN_USE, &state->flags);
562 			lsp = new;
563 			new = NULL;
564 			break;
565 		}
566 		spin_unlock(&state->state_lock);
567 		new = nfs4_alloc_lock_state(state, owner);
568 		if (new == NULL)
569 			return NULL;
570 	}
571 	spin_unlock(&state->state_lock);
572 	kfree(new);
573 	return lsp;
574 }
575 
576 /*
577  * Release reference to lock_state, and free it if we see that
578  * it is no longer in use
579  */
580 void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
581 {
582 	struct nfs4_state *state;
583 
584 	if (lsp == NULL)
585 		return;
586 	state = lsp->ls_state;
587 	if (!atomic_dec_and_lock(&lsp->ls_count, &state->state_lock))
588 		return;
589 	list_del(&lsp->ls_locks);
590 	if (list_empty(&state->lock_states))
591 		clear_bit(LK_STATE_IN_USE, &state->flags);
592 	spin_unlock(&state->state_lock);
593 	kfree(lsp);
594 }
595 
596 static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
597 {
598 	struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
599 
600 	dst->fl_u.nfs4_fl.owner = lsp;
601 	atomic_inc(&lsp->ls_count);
602 }
603 
604 static void nfs4_fl_release_lock(struct file_lock *fl)
605 {
606 	nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
607 }
608 
609 static struct file_lock_operations nfs4_fl_lock_ops = {
610 	.fl_copy_lock = nfs4_fl_copy_lock,
611 	.fl_release_private = nfs4_fl_release_lock,
612 };
613 
614 int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
615 {
616 	struct nfs4_lock_state *lsp;
617 
618 	if (fl->fl_ops != NULL)
619 		return 0;
620 	lsp = nfs4_get_lock_state(state, fl->fl_owner);
621 	if (lsp == NULL)
622 		return -ENOMEM;
623 	fl->fl_u.nfs4_fl.owner = lsp;
624 	fl->fl_ops = &nfs4_fl_lock_ops;
625 	return 0;
626 }
627 
628 /*
629  * Byte-range lock aware utility to initialize the stateid of read/write
630  * requests.
631  */
632 void nfs4_copy_stateid(nfs4_stateid *dst, struct nfs4_state *state, fl_owner_t fl_owner)
633 {
634 	struct nfs4_lock_state *lsp;
635 
636 	memcpy(dst, &state->stateid, sizeof(*dst));
637 	if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
638 		return;
639 
640 	spin_lock(&state->state_lock);
641 	lsp = __nfs4_find_lock_state(state, fl_owner);
642 	if (lsp != NULL && (lsp->ls_flags & NFS_LOCK_INITIALIZED) != 0)
643 		memcpy(dst, &lsp->ls_stateid, sizeof(*dst));
644 	spin_unlock(&state->state_lock);
645 	nfs4_put_lock_state(lsp);
646 }
647 
648 struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter)
649 {
650 	struct nfs_seqid *new;
651 
652 	new = kmalloc(sizeof(*new), GFP_KERNEL);
653 	if (new != NULL) {
654 		new->sequence = counter;
655 		INIT_LIST_HEAD(&new->list);
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 	if (!list_empty(&seqid->list)) {
665 		spin_lock(&sequence->lock);
666 		list_del(&seqid->list);
667 		spin_unlock(&sequence->lock);
668 	}
669 	rpc_wake_up_next(&sequence->wait);
670 	kfree(seqid);
671 }
672 
673 /*
674  * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
675  * failed with a seqid incrementing error -
676  * see comments nfs_fs.h:seqid_mutating_error()
677  */
678 static inline void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
679 {
680 	switch (status) {
681 		case 0:
682 			break;
683 		case -NFS4ERR_BAD_SEQID:
684 		case -NFS4ERR_STALE_CLIENTID:
685 		case -NFS4ERR_STALE_STATEID:
686 		case -NFS4ERR_BAD_STATEID:
687 		case -NFS4ERR_BADXDR:
688 		case -NFS4ERR_RESOURCE:
689 		case -NFS4ERR_NOFILEHANDLE:
690 			/* Non-seqid mutating errors */
691 			return;
692 	};
693 	/*
694 	 * Note: no locking needed as we are guaranteed to be first
695 	 * on the sequence list
696 	 */
697 	seqid->sequence->counter++;
698 }
699 
700 void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
701 {
702 	if (status == -NFS4ERR_BAD_SEQID) {
703 		struct nfs4_state_owner *sp = container_of(seqid->sequence,
704 				struct nfs4_state_owner, so_seqid);
705 		nfs4_drop_state_owner(sp);
706 	}
707 	return nfs_increment_seqid(status, seqid);
708 }
709 
710 /*
711  * Increment the seqid if the LOCK/LOCKU succeeded, or
712  * failed with a seqid incrementing error -
713  * see comments nfs_fs.h:seqid_mutating_error()
714  */
715 void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
716 {
717 	return nfs_increment_seqid(status, seqid);
718 }
719 
720 int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
721 {
722 	struct rpc_sequence *sequence = seqid->sequence->sequence;
723 	int status = 0;
724 
725 	if (sequence->list.next == &seqid->list)
726 		goto out;
727 	spin_lock(&sequence->lock);
728 	if (!list_empty(&sequence->list)) {
729 		rpc_sleep_on(&sequence->wait, task, NULL, NULL);
730 		status = -EAGAIN;
731 	} else
732 		list_add(&seqid->list, &sequence->list);
733 	spin_unlock(&sequence->lock);
734 out:
735 	return status;
736 }
737 
738 static int reclaimer(void *);
739 struct reclaimer_args {
740 	struct nfs4_client *clp;
741 	struct completion complete;
742 };
743 
744 /*
745  * State recovery routine
746  */
747 void
748 nfs4_recover_state(void *data)
749 {
750 	struct nfs4_client *clp = (struct nfs4_client *)data;
751 	struct reclaimer_args args = {
752 		.clp = clp,
753 	};
754 	might_sleep();
755 
756 	init_completion(&args.complete);
757 
758 	if (kernel_thread(reclaimer, &args, CLONE_KERNEL) < 0)
759 		goto out_failed_clear;
760 	wait_for_completion(&args.complete);
761 	return;
762 out_failed_clear:
763 	set_bit(NFS4CLNT_OK, &clp->cl_state);
764 	wake_up_all(&clp->cl_waitq);
765 	rpc_wake_up(&clp->cl_rpcwaitq);
766 }
767 
768 /*
769  * Schedule a state recovery attempt
770  */
771 void
772 nfs4_schedule_state_recovery(struct nfs4_client *clp)
773 {
774 	if (!clp)
775 		return;
776 	if (test_and_clear_bit(NFS4CLNT_OK, &clp->cl_state))
777 		schedule_work(&clp->cl_recoverd);
778 }
779 
780 static int nfs4_reclaim_locks(struct nfs4_state_recovery_ops *ops, struct nfs4_state *state)
781 {
782 	struct inode *inode = state->inode;
783 	struct file_lock *fl;
784 	int status = 0;
785 
786 	for (fl = inode->i_flock; fl != 0; fl = fl->fl_next) {
787 		if (!(fl->fl_flags & (FL_POSIX|FL_FLOCK)))
788 			continue;
789 		if (((struct nfs_open_context *)fl->fl_file->private_data)->state != state)
790 			continue;
791 		status = ops->recover_lock(state, fl);
792 		if (status >= 0)
793 			continue;
794 		switch (status) {
795 			default:
796 				printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
797 						__FUNCTION__, status);
798 			case -NFS4ERR_EXPIRED:
799 			case -NFS4ERR_NO_GRACE:
800 			case -NFS4ERR_RECLAIM_BAD:
801 			case -NFS4ERR_RECLAIM_CONFLICT:
802 				/* kill_proc(fl->fl_pid, SIGLOST, 1); */
803 				break;
804 			case -NFS4ERR_STALE_CLIENTID:
805 				goto out_err;
806 		}
807 	}
808 	return 0;
809 out_err:
810 	return status;
811 }
812 
813 static int nfs4_reclaim_open_state(struct nfs4_state_recovery_ops *ops, struct nfs4_state_owner *sp)
814 {
815 	struct nfs4_state *state;
816 	struct nfs4_lock_state *lock;
817 	int status = 0;
818 
819 	/* Note: we rely on the sp->so_states list being ordered
820 	 * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
821 	 * states first.
822 	 * This is needed to ensure that the server won't give us any
823 	 * read delegations that we have to return if, say, we are
824 	 * recovering after a network partition or a reboot from a
825 	 * server that doesn't support a grace period.
826 	 */
827 	list_for_each_entry(state, &sp->so_states, open_states) {
828 		if (state->state == 0)
829 			continue;
830 		status = ops->recover_open(sp, state);
831 		if (status >= 0) {
832 			status = nfs4_reclaim_locks(ops, state);
833 			if (status < 0)
834 				goto out_err;
835 			list_for_each_entry(lock, &state->lock_states, ls_locks) {
836 				if (!(lock->ls_flags & NFS_LOCK_INITIALIZED))
837 					printk("%s: Lock reclaim failed!\n",
838 							__FUNCTION__);
839 			}
840 			continue;
841 		}
842 		switch (status) {
843 			default:
844 				printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
845 						__FUNCTION__, status);
846 			case -ENOENT:
847 			case -NFS4ERR_RECLAIM_BAD:
848 			case -NFS4ERR_RECLAIM_CONFLICT:
849 				/*
850 				 * Open state on this file cannot be recovered
851 				 * All we can do is revert to using the zero stateid.
852 				 */
853 				memset(state->stateid.data, 0,
854 					sizeof(state->stateid.data));
855 				/* Mark the file as being 'closed' */
856 				state->state = 0;
857 				break;
858 			case -NFS4ERR_EXPIRED:
859 			case -NFS4ERR_NO_GRACE:
860 			case -NFS4ERR_STALE_CLIENTID:
861 				goto out_err;
862 		}
863 	}
864 	return 0;
865 out_err:
866 	return status;
867 }
868 
869 static void nfs4_state_mark_reclaim(struct nfs4_client *clp)
870 {
871 	struct nfs4_state_owner *sp;
872 	struct nfs4_state *state;
873 	struct nfs4_lock_state *lock;
874 
875 	/* Reset all sequence ids to zero */
876 	list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
877 		sp->so_seqid.counter = 0;
878 		sp->so_seqid.flags = 0;
879 		spin_lock(&sp->so_lock);
880 		list_for_each_entry(state, &sp->so_states, open_states) {
881 			list_for_each_entry(lock, &state->lock_states, ls_locks) {
882 				lock->ls_seqid.counter = 0;
883 				lock->ls_seqid.flags = 0;
884 				lock->ls_flags &= ~NFS_LOCK_INITIALIZED;
885 			}
886 		}
887 		spin_unlock(&sp->so_lock);
888 	}
889 }
890 
891 static int reclaimer(void *ptr)
892 {
893 	struct reclaimer_args *args = (struct reclaimer_args *)ptr;
894 	struct nfs4_client *clp = args->clp;
895 	struct nfs4_state_owner *sp;
896 	struct nfs4_state_recovery_ops *ops;
897 	int status = 0;
898 
899 	daemonize("%u.%u.%u.%u-reclaim", NIPQUAD(clp->cl_addr));
900 	allow_signal(SIGKILL);
901 
902 	atomic_inc(&clp->cl_count);
903 	complete(&args->complete);
904 
905 	/* Ensure exclusive access to NFSv4 state */
906 	lock_kernel();
907 	down_write(&clp->cl_sem);
908 	/* Are there any NFS mounts out there? */
909 	if (list_empty(&clp->cl_superblocks))
910 		goto out;
911 restart_loop:
912 	status = nfs4_proc_renew(clp);
913 	switch (status) {
914 		case 0:
915 		case -NFS4ERR_CB_PATH_DOWN:
916 			goto out;
917 		case -NFS4ERR_STALE_CLIENTID:
918 		case -NFS4ERR_LEASE_MOVED:
919 			ops = &nfs4_reboot_recovery_ops;
920 			break;
921 		default:
922 			ops = &nfs4_network_partition_recovery_ops;
923 	};
924 	nfs4_state_mark_reclaim(clp);
925 	status = __nfs4_init_client(clp);
926 	if (status)
927 		goto out_error;
928 	/* Mark all delegations for reclaim */
929 	nfs_delegation_mark_reclaim(clp);
930 	/* Note: list is protected by exclusive lock on cl->cl_sem */
931 	list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
932 		status = nfs4_reclaim_open_state(ops, sp);
933 		if (status < 0) {
934 			if (status == -NFS4ERR_NO_GRACE) {
935 				ops = &nfs4_network_partition_recovery_ops;
936 				status = nfs4_reclaim_open_state(ops, sp);
937 			}
938 			if (status == -NFS4ERR_STALE_CLIENTID)
939 				goto restart_loop;
940 			if (status == -NFS4ERR_EXPIRED)
941 				goto restart_loop;
942 		}
943 	}
944 	nfs_delegation_reap_unclaimed(clp);
945 out:
946 	set_bit(NFS4CLNT_OK, &clp->cl_state);
947 	up_write(&clp->cl_sem);
948 	unlock_kernel();
949 	wake_up_all(&clp->cl_waitq);
950 	rpc_wake_up(&clp->cl_rpcwaitq);
951 	if (status == -NFS4ERR_CB_PATH_DOWN)
952 		nfs_handle_cb_pathdown(clp);
953 	nfs4_put_client(clp);
954 	return 0;
955 out_error:
956 	printk(KERN_WARNING "Error: state recovery failed on NFSv4 server %u.%u.%u.%u with error %d\n",
957 				NIPQUAD(clp->cl_addr.s_addr), -status);
958 	goto out;
959 }
960 
961 /*
962  * Local variables:
963  *  c-basic-offset: 8
964  * End:
965  */
966