[PATCH] NFSv4: Clean up nfs4 lock state accounting
[linux-2.6.git] / fs / nfs / nfs4state.c
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 = kmalloc(sizeof(*sp),GFP_KERNEL);
268         if (!sp)
269                 return NULL;
270         init_MUTEX(&sp->so_sema);
271         sp->so_seqid = 0;                 /* arbitrary */
272         INIT_LIST_HEAD(&sp->so_states);
273         INIT_LIST_HEAD(&sp->so_delegations);
274         atomic_set(&sp->so_count, 1);
275         return sp;
276 }
277
278 void
279 nfs4_drop_state_owner(struct nfs4_state_owner *sp)
280 {
281         struct nfs4_client *clp = sp->so_client;
282         spin_lock(&clp->cl_lock);
283         list_del_init(&sp->so_list);
284         spin_unlock(&clp->cl_lock);
285 }
286
287 /*
288  * Note: must be called with clp->cl_sem held in order to prevent races
289  *       with reboot recovery!
290  */
291 struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server, struct rpc_cred *cred)
292 {
293         struct nfs4_client *clp = server->nfs4_state;
294         struct nfs4_state_owner *sp, *new;
295
296         get_rpccred(cred);
297         new = nfs4_alloc_state_owner();
298         spin_lock(&clp->cl_lock);
299         sp = nfs4_find_state_owner(clp, cred);
300         if (sp == NULL)
301                 sp = nfs4_client_grab_unused(clp, cred);
302         if (sp == NULL && new != NULL) {
303                 list_add(&new->so_list, &clp->cl_state_owners);
304                 new->so_client = clp;
305                 new->so_id = nfs4_alloc_lockowner_id(clp);
306                 new->so_cred = cred;
307                 sp = new;
308                 new = NULL;
309         }
310         spin_unlock(&clp->cl_lock);
311         if (new)
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         init_MUTEX(&state->lock_sema);
363         spin_lock_init(&state->state_lock);
364         return state;
365 }
366
367 static struct nfs4_state *
368 __nfs4_find_state(struct inode *inode, struct rpc_cred *cred, mode_t mode)
369 {
370         struct nfs_inode *nfsi = NFS_I(inode);
371         struct nfs4_state *state;
372
373         mode &= (FMODE_READ|FMODE_WRITE);
374         list_for_each_entry(state, &nfsi->open_states, inode_states) {
375                 if (state->owner->so_cred != cred)
376                         continue;
377                 if ((mode & FMODE_READ) != 0 && state->nreaders == 0)
378                         continue;
379                 if ((mode & FMODE_WRITE) != 0 && state->nwriters == 0)
380                         continue;
381                 if ((state->state & mode) != mode)
382                         continue;
383                 atomic_inc(&state->count);
384                 if (mode & FMODE_READ)
385                         state->nreaders++;
386                 if (mode & FMODE_WRITE)
387                         state->nwriters++;
388                 return state;
389         }
390         return NULL;
391 }
392
393 static struct nfs4_state *
394 __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
395 {
396         struct nfs_inode *nfsi = NFS_I(inode);
397         struct nfs4_state *state;
398
399         list_for_each_entry(state, &nfsi->open_states, inode_states) {
400                 /* Is this in the process of being freed? */
401                 if (state->nreaders == 0 && state->nwriters == 0)
402                         continue;
403                 if (state->owner == owner) {
404                         atomic_inc(&state->count);
405                         return state;
406                 }
407         }
408         return NULL;
409 }
410
411 struct nfs4_state *
412 nfs4_find_state(struct inode *inode, struct rpc_cred *cred, mode_t mode)
413 {
414         struct nfs4_state *state;
415
416         spin_lock(&inode->i_lock);
417         state = __nfs4_find_state(inode, cred, mode);
418         spin_unlock(&inode->i_lock);
419         return state;
420 }
421
422 static void
423 nfs4_free_open_state(struct nfs4_state *state)
424 {
425         kfree(state);
426 }
427
428 struct nfs4_state *
429 nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
430 {
431         struct nfs4_state *state, *new;
432         struct nfs_inode *nfsi = NFS_I(inode);
433
434         spin_lock(&inode->i_lock);
435         state = __nfs4_find_state_byowner(inode, owner);
436         spin_unlock(&inode->i_lock);
437         if (state)
438                 goto out;
439         new = nfs4_alloc_open_state();
440         spin_lock(&inode->i_lock);
441         state = __nfs4_find_state_byowner(inode, owner);
442         if (state == NULL && new != NULL) {
443                 state = new;
444                 /* Caller *must* be holding owner->so_sem */
445                 /* Note: The reclaim code dictates that we add stateless
446                  * and read-only stateids to the end of the list */
447                 list_add_tail(&state->open_states, &owner->so_states);
448                 state->owner = owner;
449                 atomic_inc(&owner->so_count);
450                 list_add(&state->inode_states, &nfsi->open_states);
451                 state->inode = igrab(inode);
452                 spin_unlock(&inode->i_lock);
453         } else {
454                 spin_unlock(&inode->i_lock);
455                 if (new)
456                         nfs4_free_open_state(new);
457         }
458 out:
459         return state;
460 }
461
462 /*
463  * Beware! Caller must be holding exactly one
464  * reference to clp->cl_sem and owner->so_sema!
465  */
466 void nfs4_put_open_state(struct nfs4_state *state)
467 {
468         struct inode *inode = state->inode;
469         struct nfs4_state_owner *owner = state->owner;
470
471         if (!atomic_dec_and_lock(&state->count, &inode->i_lock))
472                 return;
473         if (!list_empty(&state->inode_states))
474                 list_del(&state->inode_states);
475         spin_unlock(&inode->i_lock);
476         list_del(&state->open_states);
477         iput(inode);
478         BUG_ON (state->state != 0);
479         nfs4_free_open_state(state);
480         nfs4_put_state_owner(owner);
481 }
482
483 /*
484  * Beware! Caller must be holding no references to clp->cl_sem!
485  * of owner->so_sema!
486  */
487 void nfs4_close_state(struct nfs4_state *state, mode_t mode)
488 {
489         struct inode *inode = state->inode;
490         struct nfs4_state_owner *owner = state->owner;
491         struct nfs4_client *clp = owner->so_client;
492         int newstate;
493
494         atomic_inc(&owner->so_count);
495         down_read(&clp->cl_sem);
496         down(&owner->so_sema);
497         /* Protect against nfs4_find_state() */
498         spin_lock(&inode->i_lock);
499         if (mode & FMODE_READ)
500                 state->nreaders--;
501         if (mode & FMODE_WRITE)
502                 state->nwriters--;
503         if (state->nwriters == 0) {
504                 if (state->nreaders == 0)
505                         list_del_init(&state->inode_states);
506                 /* See reclaim code */
507                 list_move_tail(&state->open_states, &owner->so_states);
508         }
509         spin_unlock(&inode->i_lock);
510         newstate = 0;
511         if (state->state != 0) {
512                 if (state->nreaders)
513                         newstate |= FMODE_READ;
514                 if (state->nwriters)
515                         newstate |= FMODE_WRITE;
516                 if (state->state == newstate)
517                         goto out;
518                 if (nfs4_do_close(inode, state, newstate) == -EINPROGRESS)
519                         return;
520         }
521 out:
522         nfs4_put_open_state(state);
523         up(&owner->so_sema);
524         nfs4_put_state_owner(owner);
525         up_read(&clp->cl_sem);
526 }
527
528 /*
529  * Search the state->lock_states for an existing lock_owner
530  * that is compatible with current->files
531  */
532 static struct nfs4_lock_state *
533 __nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
534 {
535         struct nfs4_lock_state *pos;
536         list_for_each_entry(pos, &state->lock_states, ls_locks) {
537                 if (pos->ls_owner != fl_owner)
538                         continue;
539                 atomic_inc(&pos->ls_count);
540                 return pos;
541         }
542         return NULL;
543 }
544
545 /*
546  * Return a compatible lock_state. If no initialized lock_state structure
547  * exists, return an uninitialized one.
548  *
549  * The caller must be holding state->lock_sema
550  */
551 static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
552 {
553         struct nfs4_lock_state *lsp;
554         struct nfs4_client *clp = state->owner->so_client;
555
556         lsp = kmalloc(sizeof(*lsp), GFP_KERNEL);
557         if (lsp == NULL)
558                 return NULL;
559         lsp->ls_flags = 0;
560         lsp->ls_seqid = 0;      /* arbitrary */
561         memset(lsp->ls_stateid.data, 0, sizeof(lsp->ls_stateid.data));
562         atomic_set(&lsp->ls_count, 1);
563         lsp->ls_owner = fl_owner;
564         spin_lock(&clp->cl_lock);
565         lsp->ls_id = nfs4_alloc_lockowner_id(clp);
566         spin_unlock(&clp->cl_lock);
567         INIT_LIST_HEAD(&lsp->ls_locks);
568         return lsp;
569 }
570
571 /*
572  * Return a compatible lock_state. If no initialized lock_state structure
573  * exists, return an uninitialized one.
574  *
575  * The caller must be holding state->lock_sema and clp->cl_sem
576  */
577 static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
578 {
579         struct nfs4_lock_state *lsp, *new = NULL;
580         
581         for(;;) {
582                 spin_lock(&state->state_lock);
583                 lsp = __nfs4_find_lock_state(state, owner);
584                 if (lsp != NULL)
585                         break;
586                 if (new != NULL) {
587                         new->ls_state = state;
588                         list_add(&new->ls_locks, &state->lock_states);
589                         set_bit(LK_STATE_IN_USE, &state->flags);
590                         lsp = new;
591                         new = NULL;
592                         break;
593                 }
594                 spin_unlock(&state->state_lock);
595                 new = nfs4_alloc_lock_state(state, owner);
596                 if (new == NULL)
597                         return NULL;
598         }
599         spin_unlock(&state->state_lock);
600         kfree(new);
601         return lsp;
602 }
603
604 /*
605  * Release reference to lock_state, and free it if we see that
606  * it is no longer in use
607  */
608 static void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
609 {
610         struct nfs4_state *state;
611
612         if (lsp == NULL)
613                 return;
614         state = lsp->ls_state;
615         if (!atomic_dec_and_lock(&lsp->ls_count, &state->state_lock))
616                 return;
617         list_del(&lsp->ls_locks);
618         if (list_empty(&state->lock_states))
619                 clear_bit(LK_STATE_IN_USE, &state->flags);
620         spin_unlock(&state->state_lock);
621         kfree(lsp);
622 }
623
624 static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
625 {
626         struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
627
628         dst->fl_u.nfs4_fl.owner = lsp;
629         atomic_inc(&lsp->ls_count);
630 }
631
632 static void nfs4_fl_release_lock(struct file_lock *fl)
633 {
634         nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
635 }
636
637 static struct file_lock_operations nfs4_fl_lock_ops = {
638         .fl_copy_lock = nfs4_fl_copy_lock,
639         .fl_release_private = nfs4_fl_release_lock,
640 };
641
642 int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
643 {
644         struct nfs4_lock_state *lsp;
645
646         if (fl->fl_ops != NULL)
647                 return 0;
648         lsp = nfs4_get_lock_state(state, fl->fl_owner);
649         if (lsp == NULL)
650                 return -ENOMEM;
651         fl->fl_u.nfs4_fl.owner = lsp;
652         fl->fl_ops = &nfs4_fl_lock_ops;
653         return 0;
654 }
655
656 /*
657  * Byte-range lock aware utility to initialize the stateid of read/write
658  * requests.
659  */
660 void nfs4_copy_stateid(nfs4_stateid *dst, struct nfs4_state *state, fl_owner_t fl_owner)
661 {
662         struct nfs4_lock_state *lsp;
663
664         memcpy(dst, &state->stateid, sizeof(*dst));
665         if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
666                 return;
667
668         spin_lock(&state->state_lock);
669         lsp = __nfs4_find_lock_state(state, fl_owner);
670         if (lsp != NULL && (lsp->ls_flags & NFS_LOCK_INITIALIZED) != 0)
671                 memcpy(dst, &lsp->ls_stateid, sizeof(*dst));
672         spin_unlock(&state->state_lock);
673         nfs4_put_lock_state(lsp);
674 }
675
676 /*
677 * Called with state->lock_sema and clp->cl_sem held.
678 */
679 void nfs4_increment_lock_seqid(int status, struct nfs4_lock_state *lsp)
680 {
681         if (status == NFS_OK || seqid_mutating_err(-status))
682                 lsp->ls_seqid++;
683 }
684
685 /*
686 * Called with sp->so_sema and clp->cl_sem held.
687 *
688 * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
689 * failed with a seqid incrementing error -
690 * see comments nfs_fs.h:seqid_mutating_error()
691 */
692 void nfs4_increment_seqid(int status, struct nfs4_state_owner *sp)
693 {
694         if (status == NFS_OK || seqid_mutating_err(-status))
695                 sp->so_seqid++;
696         /* If the server returns BAD_SEQID, unhash state_owner here */
697         if (status == -NFS4ERR_BAD_SEQID)
698                 nfs4_drop_state_owner(sp);
699 }
700
701 static int reclaimer(void *);
702 struct reclaimer_args {
703         struct nfs4_client *clp;
704         struct completion complete;
705 };
706
707 /*
708  * State recovery routine
709  */
710 void
711 nfs4_recover_state(void *data)
712 {
713         struct nfs4_client *clp = (struct nfs4_client *)data;
714         struct reclaimer_args args = {
715                 .clp = clp,
716         };
717         might_sleep();
718
719         init_completion(&args.complete);
720
721         if (kernel_thread(reclaimer, &args, CLONE_KERNEL) < 0)
722                 goto out_failed_clear;
723         wait_for_completion(&args.complete);
724         return;
725 out_failed_clear:
726         set_bit(NFS4CLNT_OK, &clp->cl_state);
727         wake_up_all(&clp->cl_waitq);
728         rpc_wake_up(&clp->cl_rpcwaitq);
729 }
730
731 /*
732  * Schedule a state recovery attempt
733  */
734 void
735 nfs4_schedule_state_recovery(struct nfs4_client *clp)
736 {
737         if (!clp)
738                 return;
739         if (test_and_clear_bit(NFS4CLNT_OK, &clp->cl_state))
740                 schedule_work(&clp->cl_recoverd);
741 }
742
743 static int nfs4_reclaim_locks(struct nfs4_state_recovery_ops *ops, struct nfs4_state *state)
744 {
745         struct inode *inode = state->inode;
746         struct file_lock *fl;
747         int status = 0;
748
749         for (fl = inode->i_flock; fl != 0; fl = fl->fl_next) {
750                 if (!(fl->fl_flags & FL_POSIX))
751                         continue;
752                 if (((struct nfs_open_context *)fl->fl_file->private_data)->state != state)
753                         continue;
754                 status = ops->recover_lock(state, fl);
755                 if (status >= 0)
756                         continue;
757                 switch (status) {
758                         default:
759                                 printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
760                                                 __FUNCTION__, status);
761                         case -NFS4ERR_EXPIRED:
762                         case -NFS4ERR_NO_GRACE:
763                         case -NFS4ERR_RECLAIM_BAD:
764                         case -NFS4ERR_RECLAIM_CONFLICT:
765                                 /* kill_proc(fl->fl_owner, SIGLOST, 1); */
766                                 break;
767                         case -NFS4ERR_STALE_CLIENTID:
768                                 goto out_err;
769                 }
770         }
771         return 0;
772 out_err:
773         return status;
774 }
775
776 static int nfs4_reclaim_open_state(struct nfs4_state_recovery_ops *ops, struct nfs4_state_owner *sp)
777 {
778         struct nfs4_state *state;
779         struct nfs4_lock_state *lock;
780         int status = 0;
781
782         /* Note: we rely on the sp->so_states list being ordered 
783          * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
784          * states first.
785          * This is needed to ensure that the server won't give us any
786          * read delegations that we have to return if, say, we are
787          * recovering after a network partition or a reboot from a
788          * server that doesn't support a grace period.
789          */
790         list_for_each_entry(state, &sp->so_states, open_states) {
791                 if (state->state == 0)
792                         continue;
793                 status = ops->recover_open(sp, state);
794                 list_for_each_entry(lock, &state->lock_states, ls_locks)
795                         lock->ls_flags &= ~NFS_LOCK_INITIALIZED;
796                 if (status >= 0) {
797                         status = nfs4_reclaim_locks(ops, state);
798                         if (status < 0)
799                                 goto out_err;
800                         list_for_each_entry(lock, &state->lock_states, ls_locks) {
801                                 if (!(lock->ls_flags & NFS_LOCK_INITIALIZED))
802                                         printk("%s: Lock reclaim failed!\n",
803                                                         __FUNCTION__);
804                         }
805                         continue;
806                 }
807                 switch (status) {
808                         default:
809                                 printk(KERN_ERR "%s: unhandled error %d. Zeroing state\n",
810                                                 __FUNCTION__, status);
811                         case -ENOENT:
812                         case -NFS4ERR_RECLAIM_BAD:
813                         case -NFS4ERR_RECLAIM_CONFLICT:
814                                 /*
815                                  * Open state on this file cannot be recovered
816                                  * All we can do is revert to using the zero stateid.
817                                  */
818                                 memset(state->stateid.data, 0,
819                                         sizeof(state->stateid.data));
820                                 /* Mark the file as being 'closed' */
821                                 state->state = 0;
822                                 break;
823                         case -NFS4ERR_EXPIRED:
824                         case -NFS4ERR_NO_GRACE:
825                         case -NFS4ERR_STALE_CLIENTID:
826                                 goto out_err;
827                 }
828         }
829         return 0;
830 out_err:
831         return status;
832 }
833
834 static int reclaimer(void *ptr)
835 {
836         struct reclaimer_args *args = (struct reclaimer_args *)ptr;
837         struct nfs4_client *clp = args->clp;
838         struct nfs4_state_owner *sp;
839         struct nfs4_state_recovery_ops *ops;
840         int status = 0;
841
842         daemonize("%u.%u.%u.%u-reclaim", NIPQUAD(clp->cl_addr));
843         allow_signal(SIGKILL);
844
845         atomic_inc(&clp->cl_count);
846         complete(&args->complete);
847
848         /* Ensure exclusive access to NFSv4 state */
849         lock_kernel();
850         down_write(&clp->cl_sem);
851         /* Are there any NFS mounts out there? */
852         if (list_empty(&clp->cl_superblocks))
853                 goto out;
854 restart_loop:
855         status = nfs4_proc_renew(clp);
856         switch (status) {
857                 case 0:
858                 case -NFS4ERR_CB_PATH_DOWN:
859                         goto out;
860                 case -NFS4ERR_STALE_CLIENTID:
861                 case -NFS4ERR_LEASE_MOVED:
862                         ops = &nfs4_reboot_recovery_ops;
863                         break;
864                 default:
865                         ops = &nfs4_network_partition_recovery_ops;
866         };
867         status = __nfs4_init_client(clp);
868         if (status)
869                 goto out_error;
870         /* Mark all delegations for reclaim */
871         nfs_delegation_mark_reclaim(clp);
872         /* Note: list is protected by exclusive lock on cl->cl_sem */
873         list_for_each_entry(sp, &clp->cl_state_owners, so_list) {
874                 status = nfs4_reclaim_open_state(ops, sp);
875                 if (status < 0) {
876                         if (status == -NFS4ERR_NO_GRACE) {
877                                 ops = &nfs4_network_partition_recovery_ops;
878                                 status = nfs4_reclaim_open_state(ops, sp);
879                         }
880                         if (status == -NFS4ERR_STALE_CLIENTID)
881                                 goto restart_loop;
882                         if (status == -NFS4ERR_EXPIRED)
883                                 goto restart_loop;
884                 }
885         }
886         nfs_delegation_reap_unclaimed(clp);
887 out:
888         set_bit(NFS4CLNT_OK, &clp->cl_state);
889         up_write(&clp->cl_sem);
890         unlock_kernel();
891         wake_up_all(&clp->cl_waitq);
892         rpc_wake_up(&clp->cl_rpcwaitq);
893         if (status == -NFS4ERR_CB_PATH_DOWN)
894                 nfs_handle_cb_pathdown(clp);
895         nfs4_put_client(clp);
896         return 0;
897 out_error:
898         printk(KERN_WARNING "Error: state recovery failed on NFSv4 server %u.%u.%u.%u with error %d\n",
899                                 NIPQUAD(clp->cl_addr.s_addr), -status);
900         goto out;
901 }
902
903 /*
904  * Local variables:
905  *  c-basic-offset: 8
906  * End:
907  */