Upgrade to 4.4.50-rt62
[kvmfornfv.git] / kernel / 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/kernel.h>
42 #include <linux/slab.h>
43 #include <linux/fs.h>
44 #include <linux/nfs_fs.h>
45 #include <linux/kthread.h>
46 #include <linux/module.h>
47 #include <linux/random.h>
48 #include <linux/ratelimit.h>
49 #include <linux/workqueue.h>
50 #include <linux/bitops.h>
51 #include <linux/jiffies.h>
52
53 #include <linux/sunrpc/clnt.h>
54
55 #include "nfs4_fs.h"
56 #include "callback.h"
57 #include "delegation.h"
58 #include "internal.h"
59 #include "nfs4idmap.h"
60 #include "nfs4session.h"
61 #include "pnfs.h"
62 #include "netns.h"
63
64 #define NFSDBG_FACILITY         NFSDBG_STATE
65
66 #define OPENOWNER_POOL_SIZE     8
67
68 const nfs4_stateid zero_stateid;
69 static DEFINE_MUTEX(nfs_clid_init_mutex);
70
71 int nfs4_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
72 {
73         struct nfs4_setclientid_res clid = {
74                 .clientid = clp->cl_clientid,
75                 .confirm = clp->cl_confirm,
76         };
77         unsigned short port;
78         int status;
79         struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
80
81         if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
82                 goto do_confirm;
83         port = nn->nfs_callback_tcpport;
84         if (clp->cl_addr.ss_family == AF_INET6)
85                 port = nn->nfs_callback_tcpport6;
86
87         status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
88         if (status != 0)
89                 goto out;
90         clp->cl_clientid = clid.clientid;
91         clp->cl_confirm = clid.confirm;
92         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
93 do_confirm:
94         status = nfs4_proc_setclientid_confirm(clp, &clid, cred);
95         if (status != 0)
96                 goto out;
97         clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
98         nfs4_schedule_state_renewal(clp);
99 out:
100         return status;
101 }
102
103 /**
104  * nfs40_discover_server_trunking - Detect server IP address trunking (mv0)
105  *
106  * @clp: nfs_client under test
107  * @result: OUT: found nfs_client, or clp
108  * @cred: credential to use for trunking test
109  *
110  * Returns zero, a negative errno, or a negative NFS4ERR status.
111  * If zero is returned, an nfs_client pointer is planted in
112  * "result".
113  *
114  * Note: The returned client may not yet be marked ready.
115  */
116 int nfs40_discover_server_trunking(struct nfs_client *clp,
117                                    struct nfs_client **result,
118                                    struct rpc_cred *cred)
119 {
120         struct nfs4_setclientid_res clid = {
121                 .clientid = clp->cl_clientid,
122                 .confirm = clp->cl_confirm,
123         };
124         struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
125         unsigned short port;
126         int status;
127
128         port = nn->nfs_callback_tcpport;
129         if (clp->cl_addr.ss_family == AF_INET6)
130                 port = nn->nfs_callback_tcpport6;
131
132         status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
133         if (status != 0)
134                 goto out;
135         clp->cl_clientid = clid.clientid;
136         clp->cl_confirm = clid.confirm;
137
138         status = nfs40_walk_client_list(clp, result, cred);
139         if (status == 0) {
140                 /* Sustain the lease, even if it's empty.  If the clientid4
141                  * goes stale it's of no use for trunking discovery. */
142                 nfs4_schedule_state_renewal(*result);
143         }
144 out:
145         return status;
146 }
147
148 struct rpc_cred *nfs4_get_machine_cred_locked(struct nfs_client *clp)
149 {
150         struct rpc_cred *cred = NULL;
151
152         if (clp->cl_machine_cred != NULL)
153                 cred = get_rpccred(clp->cl_machine_cred);
154         return cred;
155 }
156
157 static void nfs4_root_machine_cred(struct nfs_client *clp)
158 {
159         struct rpc_cred *cred, *new;
160
161         new = rpc_lookup_machine_cred(NULL);
162         spin_lock(&clp->cl_lock);
163         cred = clp->cl_machine_cred;
164         clp->cl_machine_cred = new;
165         spin_unlock(&clp->cl_lock);
166         if (cred != NULL)
167                 put_rpccred(cred);
168 }
169
170 static struct rpc_cred *
171 nfs4_get_renew_cred_server_locked(struct nfs_server *server)
172 {
173         struct rpc_cred *cred = NULL;
174         struct nfs4_state_owner *sp;
175         struct rb_node *pos;
176
177         for (pos = rb_first(&server->state_owners);
178              pos != NULL;
179              pos = rb_next(pos)) {
180                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
181                 if (list_empty(&sp->so_states))
182                         continue;
183                 cred = get_rpccred(sp->so_cred);
184                 break;
185         }
186         return cred;
187 }
188
189 /**
190  * nfs4_get_renew_cred_locked - Acquire credential for a renew operation
191  * @clp: client state handle
192  *
193  * Returns an rpc_cred with reference count bumped, or NULL.
194  * Caller must hold clp->cl_lock.
195  */
196 struct rpc_cred *nfs4_get_renew_cred_locked(struct nfs_client *clp)
197 {
198         struct rpc_cred *cred = NULL;
199         struct nfs_server *server;
200
201         /* Use machine credentials if available */
202         cred = nfs4_get_machine_cred_locked(clp);
203         if (cred != NULL)
204                 goto out;
205
206         rcu_read_lock();
207         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
208                 cred = nfs4_get_renew_cred_server_locked(server);
209                 if (cred != NULL)
210                         break;
211         }
212         rcu_read_unlock();
213
214 out:
215         return cred;
216 }
217
218 static void nfs4_end_drain_slot_table(struct nfs4_slot_table *tbl)
219 {
220         if (test_and_clear_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state)) {
221                 spin_lock(&tbl->slot_tbl_lock);
222                 nfs41_wake_slot_table(tbl);
223                 spin_unlock(&tbl->slot_tbl_lock);
224         }
225 }
226
227 static void nfs4_end_drain_session(struct nfs_client *clp)
228 {
229         struct nfs4_session *ses = clp->cl_session;
230
231         if (clp->cl_slot_tbl) {
232                 nfs4_end_drain_slot_table(clp->cl_slot_tbl);
233                 return;
234         }
235
236         if (ses != NULL) {
237                 nfs4_end_drain_slot_table(&ses->bc_slot_table);
238                 nfs4_end_drain_slot_table(&ses->fc_slot_table);
239         }
240 }
241
242 static int nfs4_drain_slot_tbl(struct nfs4_slot_table *tbl)
243 {
244         set_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
245         spin_lock(&tbl->slot_tbl_lock);
246         if (tbl->highest_used_slotid != NFS4_NO_SLOT) {
247                 reinit_completion(&tbl->complete);
248                 spin_unlock(&tbl->slot_tbl_lock);
249                 return wait_for_completion_interruptible(&tbl->complete);
250         }
251         spin_unlock(&tbl->slot_tbl_lock);
252         return 0;
253 }
254
255 static int nfs4_begin_drain_session(struct nfs_client *clp)
256 {
257         struct nfs4_session *ses = clp->cl_session;
258         int ret = 0;
259
260         if (clp->cl_slot_tbl)
261                 return nfs4_drain_slot_tbl(clp->cl_slot_tbl);
262
263         /* back channel */
264         ret = nfs4_drain_slot_tbl(&ses->bc_slot_table);
265         if (ret)
266                 return ret;
267         /* fore channel */
268         return nfs4_drain_slot_tbl(&ses->fc_slot_table);
269 }
270
271 #if defined(CONFIG_NFS_V4_1)
272
273 static int nfs41_setup_state_renewal(struct nfs_client *clp)
274 {
275         int status;
276         struct nfs_fsinfo fsinfo;
277
278         if (!test_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state)) {
279                 nfs4_schedule_state_renewal(clp);
280                 return 0;
281         }
282
283         status = nfs4_proc_get_lease_time(clp, &fsinfo);
284         if (status == 0) {
285                 /* Update lease time and schedule renewal */
286                 spin_lock(&clp->cl_lock);
287                 clp->cl_lease_time = fsinfo.lease_time * HZ;
288                 clp->cl_last_renewal = jiffies;
289                 spin_unlock(&clp->cl_lock);
290
291                 nfs4_schedule_state_renewal(clp);
292         }
293
294         return status;
295 }
296
297 static void nfs41_finish_session_reset(struct nfs_client *clp)
298 {
299         clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
300         clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
301         /* create_session negotiated new slot table */
302         clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
303         nfs41_setup_state_renewal(clp);
304 }
305
306 int nfs41_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
307 {
308         int status;
309
310         if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
311                 goto do_confirm;
312         status = nfs4_proc_exchange_id(clp, cred);
313         if (status != 0)
314                 goto out;
315         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
316 do_confirm:
317         status = nfs4_proc_create_session(clp, cred);
318         if (status != 0)
319                 goto out;
320         nfs41_finish_session_reset(clp);
321         nfs_mark_client_ready(clp, NFS_CS_READY);
322 out:
323         return status;
324 }
325
326 /**
327  * nfs41_discover_server_trunking - Detect server IP address trunking (mv1)
328  *
329  * @clp: nfs_client under test
330  * @result: OUT: found nfs_client, or clp
331  * @cred: credential to use for trunking test
332  *
333  * Returns NFS4_OK, a negative errno, or a negative NFS4ERR status.
334  * If NFS4_OK is returned, an nfs_client pointer is planted in
335  * "result".
336  *
337  * Note: The returned client may not yet be marked ready.
338  */
339 int nfs41_discover_server_trunking(struct nfs_client *clp,
340                                    struct nfs_client **result,
341                                    struct rpc_cred *cred)
342 {
343         int status;
344
345         status = nfs4_proc_exchange_id(clp, cred);
346         if (status != NFS4_OK)
347                 return status;
348
349         status = nfs41_walk_client_list(clp, result, cred);
350         if (status < 0)
351                 return status;
352         if (clp != *result)
353                 return 0;
354
355         /* Purge state if the client id was established in a prior instance */
356         if (clp->cl_exchange_flags & EXCHGID4_FLAG_CONFIRMED_R)
357                 set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
358         else
359                 set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
360         nfs4_schedule_state_manager(clp);
361         status = nfs_wait_client_init_complete(clp);
362         if (status < 0)
363                 nfs_put_client(clp);
364         return status;
365 }
366
367 #endif /* CONFIG_NFS_V4_1 */
368
369 /**
370  * nfs4_get_clid_cred - Acquire credential for a setclientid operation
371  * @clp: client state handle
372  *
373  * Returns an rpc_cred with reference count bumped, or NULL.
374  */
375 struct rpc_cred *nfs4_get_clid_cred(struct nfs_client *clp)
376 {
377         struct rpc_cred *cred;
378
379         spin_lock(&clp->cl_lock);
380         cred = nfs4_get_machine_cred_locked(clp);
381         spin_unlock(&clp->cl_lock);
382         return cred;
383 }
384
385 static struct nfs4_state_owner *
386 nfs4_find_state_owner_locked(struct nfs_server *server, struct rpc_cred *cred)
387 {
388         struct rb_node **p = &server->state_owners.rb_node,
389                        *parent = NULL;
390         struct nfs4_state_owner *sp;
391
392         while (*p != NULL) {
393                 parent = *p;
394                 sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
395
396                 if (cred < sp->so_cred)
397                         p = &parent->rb_left;
398                 else if (cred > sp->so_cred)
399                         p = &parent->rb_right;
400                 else {
401                         if (!list_empty(&sp->so_lru))
402                                 list_del_init(&sp->so_lru);
403                         atomic_inc(&sp->so_count);
404                         return sp;
405                 }
406         }
407         return NULL;
408 }
409
410 static struct nfs4_state_owner *
411 nfs4_insert_state_owner_locked(struct nfs4_state_owner *new)
412 {
413         struct nfs_server *server = new->so_server;
414         struct rb_node **p = &server->state_owners.rb_node,
415                        *parent = NULL;
416         struct nfs4_state_owner *sp;
417         int err;
418
419         while (*p != NULL) {
420                 parent = *p;
421                 sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
422
423                 if (new->so_cred < sp->so_cred)
424                         p = &parent->rb_left;
425                 else if (new->so_cred > sp->so_cred)
426                         p = &parent->rb_right;
427                 else {
428                         if (!list_empty(&sp->so_lru))
429                                 list_del_init(&sp->so_lru);
430                         atomic_inc(&sp->so_count);
431                         return sp;
432                 }
433         }
434         err = ida_get_new(&server->openowner_id, &new->so_seqid.owner_id);
435         if (err)
436                 return ERR_PTR(err);
437         rb_link_node(&new->so_server_node, parent, p);
438         rb_insert_color(&new->so_server_node, &server->state_owners);
439         return new;
440 }
441
442 static void
443 nfs4_remove_state_owner_locked(struct nfs4_state_owner *sp)
444 {
445         struct nfs_server *server = sp->so_server;
446
447         if (!RB_EMPTY_NODE(&sp->so_server_node))
448                 rb_erase(&sp->so_server_node, &server->state_owners);
449         ida_remove(&server->openowner_id, sp->so_seqid.owner_id);
450 }
451
452 static void
453 nfs4_init_seqid_counter(struct nfs_seqid_counter *sc)
454 {
455         sc->create_time = ktime_get();
456         sc->flags = 0;
457         sc->counter = 0;
458         spin_lock_init(&sc->lock);
459         INIT_LIST_HEAD(&sc->list);
460         rpc_init_wait_queue(&sc->wait, "Seqid_waitqueue");
461 }
462
463 static void
464 nfs4_destroy_seqid_counter(struct nfs_seqid_counter *sc)
465 {
466         rpc_destroy_wait_queue(&sc->wait);
467 }
468
469 /*
470  * nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
471  * create a new state_owner.
472  *
473  */
474 static struct nfs4_state_owner *
475 nfs4_alloc_state_owner(struct nfs_server *server,
476                 struct rpc_cred *cred,
477                 gfp_t gfp_flags)
478 {
479         struct nfs4_state_owner *sp;
480
481         sp = kzalloc(sizeof(*sp), gfp_flags);
482         if (!sp)
483                 return NULL;
484         sp->so_server = server;
485         sp->so_cred = get_rpccred(cred);
486         spin_lock_init(&sp->so_lock);
487         INIT_LIST_HEAD(&sp->so_states);
488         nfs4_init_seqid_counter(&sp->so_seqid);
489         atomic_set(&sp->so_count, 1);
490         INIT_LIST_HEAD(&sp->so_lru);
491         seqcount_init(&sp->so_reclaim_seqcount);
492         mutex_init(&sp->so_delegreturn_mutex);
493         return sp;
494 }
495
496 static void
497 nfs4_drop_state_owner(struct nfs4_state_owner *sp)
498 {
499         struct rb_node *rb_node = &sp->so_server_node;
500
501         if (!RB_EMPTY_NODE(rb_node)) {
502                 struct nfs_server *server = sp->so_server;
503                 struct nfs_client *clp = server->nfs_client;
504
505                 spin_lock(&clp->cl_lock);
506                 if (!RB_EMPTY_NODE(rb_node)) {
507                         rb_erase(rb_node, &server->state_owners);
508                         RB_CLEAR_NODE(rb_node);
509                 }
510                 spin_unlock(&clp->cl_lock);
511         }
512 }
513
514 static void nfs4_free_state_owner(struct nfs4_state_owner *sp)
515 {
516         nfs4_destroy_seqid_counter(&sp->so_seqid);
517         put_rpccred(sp->so_cred);
518         kfree(sp);
519 }
520
521 static void nfs4_gc_state_owners(struct nfs_server *server)
522 {
523         struct nfs_client *clp = server->nfs_client;
524         struct nfs4_state_owner *sp, *tmp;
525         unsigned long time_min, time_max;
526         LIST_HEAD(doomed);
527
528         spin_lock(&clp->cl_lock);
529         time_max = jiffies;
530         time_min = (long)time_max - (long)clp->cl_lease_time;
531         list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
532                 /* NB: LRU is sorted so that oldest is at the head */
533                 if (time_in_range(sp->so_expires, time_min, time_max))
534                         break;
535                 list_move(&sp->so_lru, &doomed);
536                 nfs4_remove_state_owner_locked(sp);
537         }
538         spin_unlock(&clp->cl_lock);
539
540         list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
541                 list_del(&sp->so_lru);
542                 nfs4_free_state_owner(sp);
543         }
544 }
545
546 /**
547  * nfs4_get_state_owner - Look up a state owner given a credential
548  * @server: nfs_server to search
549  * @cred: RPC credential to match
550  *
551  * Returns a pointer to an instantiated nfs4_state_owner struct, or NULL.
552  */
553 struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server,
554                                               struct rpc_cred *cred,
555                                               gfp_t gfp_flags)
556 {
557         struct nfs_client *clp = server->nfs_client;
558         struct nfs4_state_owner *sp, *new;
559
560         spin_lock(&clp->cl_lock);
561         sp = nfs4_find_state_owner_locked(server, cred);
562         spin_unlock(&clp->cl_lock);
563         if (sp != NULL)
564                 goto out;
565         new = nfs4_alloc_state_owner(server, cred, gfp_flags);
566         if (new == NULL)
567                 goto out;
568         do {
569                 if (ida_pre_get(&server->openowner_id, gfp_flags) == 0)
570                         break;
571                 spin_lock(&clp->cl_lock);
572                 sp = nfs4_insert_state_owner_locked(new);
573                 spin_unlock(&clp->cl_lock);
574         } while (sp == ERR_PTR(-EAGAIN));
575         if (sp != new)
576                 nfs4_free_state_owner(new);
577 out:
578         nfs4_gc_state_owners(server);
579         return sp;
580 }
581
582 /**
583  * nfs4_put_state_owner - Release a nfs4_state_owner
584  * @sp: state owner data to release
585  *
586  * Note that we keep released state owners on an LRU
587  * list.
588  * This caches valid state owners so that they can be
589  * reused, to avoid the OPEN_CONFIRM on minor version 0.
590  * It also pins the uniquifier of dropped state owners for
591  * a while, to ensure that those state owner names are
592  * never reused.
593  */
594 void nfs4_put_state_owner(struct nfs4_state_owner *sp)
595 {
596         struct nfs_server *server = sp->so_server;
597         struct nfs_client *clp = server->nfs_client;
598
599         if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
600                 return;
601
602         sp->so_expires = jiffies;
603         list_add_tail(&sp->so_lru, &server->state_owners_lru);
604         spin_unlock(&clp->cl_lock);
605 }
606
607 /**
608  * nfs4_purge_state_owners - Release all cached state owners
609  * @server: nfs_server with cached state owners to release
610  *
611  * Called at umount time.  Remaining state owners will be on
612  * the LRU with ref count of zero.
613  */
614 void nfs4_purge_state_owners(struct nfs_server *server)
615 {
616         struct nfs_client *clp = server->nfs_client;
617         struct nfs4_state_owner *sp, *tmp;
618         LIST_HEAD(doomed);
619
620         spin_lock(&clp->cl_lock);
621         list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
622                 list_move(&sp->so_lru, &doomed);
623                 nfs4_remove_state_owner_locked(sp);
624         }
625         spin_unlock(&clp->cl_lock);
626
627         list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
628                 list_del(&sp->so_lru);
629                 nfs4_free_state_owner(sp);
630         }
631 }
632
633 static struct nfs4_state *
634 nfs4_alloc_open_state(void)
635 {
636         struct nfs4_state *state;
637
638         state = kzalloc(sizeof(*state), GFP_NOFS);
639         if (!state)
640                 return NULL;
641         atomic_set(&state->count, 1);
642         INIT_LIST_HEAD(&state->lock_states);
643         spin_lock_init(&state->state_lock);
644         seqlock_init(&state->seqlock);
645         return state;
646 }
647
648 void
649 nfs4_state_set_mode_locked(struct nfs4_state *state, fmode_t fmode)
650 {
651         if (state->state == fmode)
652                 return;
653         /* NB! List reordering - see the reclaim code for why.  */
654         if ((fmode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
655                 if (fmode & FMODE_WRITE)
656                         list_move(&state->open_states, &state->owner->so_states);
657                 else
658                         list_move_tail(&state->open_states, &state->owner->so_states);
659         }
660         state->state = fmode;
661 }
662
663 static struct nfs4_state *
664 __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
665 {
666         struct nfs_inode *nfsi = NFS_I(inode);
667         struct nfs4_state *state;
668
669         list_for_each_entry(state, &nfsi->open_states, inode_states) {
670                 if (state->owner != owner)
671                         continue;
672                 if (!nfs4_valid_open_stateid(state))
673                         continue;
674                 if (atomic_inc_not_zero(&state->count))
675                         return state;
676         }
677         return NULL;
678 }
679
680 static void
681 nfs4_free_open_state(struct nfs4_state *state)
682 {
683         kfree(state);
684 }
685
686 struct nfs4_state *
687 nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
688 {
689         struct nfs4_state *state, *new;
690         struct nfs_inode *nfsi = NFS_I(inode);
691
692         spin_lock(&inode->i_lock);
693         state = __nfs4_find_state_byowner(inode, owner);
694         spin_unlock(&inode->i_lock);
695         if (state)
696                 goto out;
697         new = nfs4_alloc_open_state();
698         spin_lock(&owner->so_lock);
699         spin_lock(&inode->i_lock);
700         state = __nfs4_find_state_byowner(inode, owner);
701         if (state == NULL && new != NULL) {
702                 state = new;
703                 state->owner = owner;
704                 atomic_inc(&owner->so_count);
705                 list_add(&state->inode_states, &nfsi->open_states);
706                 ihold(inode);
707                 state->inode = inode;
708                 spin_unlock(&inode->i_lock);
709                 /* Note: The reclaim code dictates that we add stateless
710                  * and read-only stateids to the end of the list */
711                 list_add_tail(&state->open_states, &owner->so_states);
712                 spin_unlock(&owner->so_lock);
713         } else {
714                 spin_unlock(&inode->i_lock);
715                 spin_unlock(&owner->so_lock);
716                 if (new)
717                         nfs4_free_open_state(new);
718         }
719 out:
720         return state;
721 }
722
723 void nfs4_put_open_state(struct nfs4_state *state)
724 {
725         struct inode *inode = state->inode;
726         struct nfs4_state_owner *owner = state->owner;
727
728         if (!atomic_dec_and_lock(&state->count, &owner->so_lock))
729                 return;
730         spin_lock(&inode->i_lock);
731         list_del(&state->inode_states);
732         list_del(&state->open_states);
733         spin_unlock(&inode->i_lock);
734         spin_unlock(&owner->so_lock);
735         iput(inode);
736         nfs4_free_open_state(state);
737         nfs4_put_state_owner(owner);
738 }
739
740 /*
741  * Close the current file.
742  */
743 static void __nfs4_close(struct nfs4_state *state,
744                 fmode_t fmode, gfp_t gfp_mask, int wait)
745 {
746         struct nfs4_state_owner *owner = state->owner;
747         int call_close = 0;
748         fmode_t newstate;
749
750         atomic_inc(&owner->so_count);
751         /* Protect against nfs4_find_state() */
752         spin_lock(&owner->so_lock);
753         switch (fmode & (FMODE_READ | FMODE_WRITE)) {
754                 case FMODE_READ:
755                         state->n_rdonly--;
756                         break;
757                 case FMODE_WRITE:
758                         state->n_wronly--;
759                         break;
760                 case FMODE_READ|FMODE_WRITE:
761                         state->n_rdwr--;
762         }
763         newstate = FMODE_READ|FMODE_WRITE;
764         if (state->n_rdwr == 0) {
765                 if (state->n_rdonly == 0) {
766                         newstate &= ~FMODE_READ;
767                         call_close |= test_bit(NFS_O_RDONLY_STATE, &state->flags);
768                         call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
769                 }
770                 if (state->n_wronly == 0) {
771                         newstate &= ~FMODE_WRITE;
772                         call_close |= test_bit(NFS_O_WRONLY_STATE, &state->flags);
773                         call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
774                 }
775                 if (newstate == 0)
776                         clear_bit(NFS_DELEGATED_STATE, &state->flags);
777         }
778         nfs4_state_set_mode_locked(state, newstate);
779         spin_unlock(&owner->so_lock);
780
781         if (!call_close) {
782                 nfs4_put_open_state(state);
783                 nfs4_put_state_owner(owner);
784         } else
785                 nfs4_do_close(state, gfp_mask, wait);
786 }
787
788 void nfs4_close_state(struct nfs4_state *state, fmode_t fmode)
789 {
790         __nfs4_close(state, fmode, GFP_NOFS, 0);
791 }
792
793 void nfs4_close_sync(struct nfs4_state *state, fmode_t fmode)
794 {
795         __nfs4_close(state, fmode, GFP_KERNEL, 1);
796 }
797
798 /*
799  * Search the state->lock_states for an existing lock_owner
800  * that is compatible with current->files
801  */
802 static struct nfs4_lock_state *
803 __nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
804 {
805         struct nfs4_lock_state *pos;
806         list_for_each_entry(pos, &state->lock_states, ls_locks) {
807                 if (pos->ls_owner != fl_owner)
808                         continue;
809                 atomic_inc(&pos->ls_count);
810                 return pos;
811         }
812         return NULL;
813 }
814
815 /*
816  * Return a compatible lock_state. If no initialized lock_state structure
817  * exists, return an uninitialized one.
818  *
819  */
820 static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
821 {
822         struct nfs4_lock_state *lsp;
823         struct nfs_server *server = state->owner->so_server;
824
825         lsp = kzalloc(sizeof(*lsp), GFP_NOFS);
826         if (lsp == NULL)
827                 return NULL;
828         nfs4_init_seqid_counter(&lsp->ls_seqid);
829         atomic_set(&lsp->ls_count, 1);
830         lsp->ls_state = state;
831         lsp->ls_owner = fl_owner;
832         lsp->ls_seqid.owner_id = ida_simple_get(&server->lockowner_id, 0, 0, GFP_NOFS);
833         if (lsp->ls_seqid.owner_id < 0)
834                 goto out_free;
835         INIT_LIST_HEAD(&lsp->ls_locks);
836         return lsp;
837 out_free:
838         kfree(lsp);
839         return NULL;
840 }
841
842 void nfs4_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp)
843 {
844         ida_simple_remove(&server->lockowner_id, lsp->ls_seqid.owner_id);
845         nfs4_destroy_seqid_counter(&lsp->ls_seqid);
846         kfree(lsp);
847 }
848
849 /*
850  * Return a compatible lock_state. If no initialized lock_state structure
851  * exists, return an uninitialized one.
852  *
853  */
854 static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
855 {
856         struct nfs4_lock_state *lsp, *new = NULL;
857         
858         for(;;) {
859                 spin_lock(&state->state_lock);
860                 lsp = __nfs4_find_lock_state(state, owner);
861                 if (lsp != NULL)
862                         break;
863                 if (new != NULL) {
864                         list_add(&new->ls_locks, &state->lock_states);
865                         set_bit(LK_STATE_IN_USE, &state->flags);
866                         lsp = new;
867                         new = NULL;
868                         break;
869                 }
870                 spin_unlock(&state->state_lock);
871                 new = nfs4_alloc_lock_state(state, owner);
872                 if (new == NULL)
873                         return NULL;
874         }
875         spin_unlock(&state->state_lock);
876         if (new != NULL)
877                 nfs4_free_lock_state(state->owner->so_server, new);
878         return lsp;
879 }
880
881 /*
882  * Release reference to lock_state, and free it if we see that
883  * it is no longer in use
884  */
885 void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
886 {
887         struct nfs_server *server;
888         struct nfs4_state *state;
889
890         if (lsp == NULL)
891                 return;
892         state = lsp->ls_state;
893         if (!atomic_dec_and_lock(&lsp->ls_count, &state->state_lock))
894                 return;
895         list_del(&lsp->ls_locks);
896         if (list_empty(&state->lock_states))
897                 clear_bit(LK_STATE_IN_USE, &state->flags);
898         spin_unlock(&state->state_lock);
899         server = state->owner->so_server;
900         if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags)) {
901                 struct nfs_client *clp = server->nfs_client;
902
903                 clp->cl_mvops->free_lock_state(server, lsp);
904         } else
905                 nfs4_free_lock_state(server, lsp);
906 }
907
908 static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
909 {
910         struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
911
912         dst->fl_u.nfs4_fl.owner = lsp;
913         atomic_inc(&lsp->ls_count);
914 }
915
916 static void nfs4_fl_release_lock(struct file_lock *fl)
917 {
918         nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
919 }
920
921 static const struct file_lock_operations nfs4_fl_lock_ops = {
922         .fl_copy_lock = nfs4_fl_copy_lock,
923         .fl_release_private = nfs4_fl_release_lock,
924 };
925
926 int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
927 {
928         struct nfs4_lock_state *lsp;
929
930         if (fl->fl_ops != NULL)
931                 return 0;
932         lsp = nfs4_get_lock_state(state, fl->fl_owner);
933         if (lsp == NULL)
934                 return -ENOMEM;
935         fl->fl_u.nfs4_fl.owner = lsp;
936         fl->fl_ops = &nfs4_fl_lock_ops;
937         return 0;
938 }
939
940 static int nfs4_copy_lock_stateid(nfs4_stateid *dst,
941                 struct nfs4_state *state,
942                 const struct nfs_lockowner *lockowner)
943 {
944         struct nfs4_lock_state *lsp;
945         fl_owner_t fl_owner;
946         int ret = -ENOENT;
947
948
949         if (lockowner == NULL)
950                 goto out;
951
952         if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
953                 goto out;
954
955         fl_owner = lockowner->l_owner;
956         spin_lock(&state->state_lock);
957         lsp = __nfs4_find_lock_state(state, fl_owner);
958         if (lsp && test_bit(NFS_LOCK_LOST, &lsp->ls_flags))
959                 ret = -EIO;
960         else if (lsp != NULL && test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags) != 0) {
961                 nfs4_stateid_copy(dst, &lsp->ls_stateid);
962                 ret = 0;
963         }
964         spin_unlock(&state->state_lock);
965         nfs4_put_lock_state(lsp);
966 out:
967         return ret;
968 }
969
970 static void nfs4_copy_open_stateid(nfs4_stateid *dst, struct nfs4_state *state)
971 {
972         const nfs4_stateid *src;
973         int seq;
974
975         do {
976                 src = &zero_stateid;
977                 seq = read_seqbegin(&state->seqlock);
978                 if (test_bit(NFS_OPEN_STATE, &state->flags))
979                         src = &state->open_stateid;
980                 nfs4_stateid_copy(dst, src);
981         } while (read_seqretry(&state->seqlock, seq));
982 }
983
984 /*
985  * Byte-range lock aware utility to initialize the stateid of read/write
986  * requests.
987  */
988 int nfs4_select_rw_stateid(nfs4_stateid *dst, struct nfs4_state *state,
989                 fmode_t fmode, const struct nfs_lockowner *lockowner)
990 {
991         int ret = nfs4_copy_lock_stateid(dst, state, lockowner);
992         if (ret == -EIO)
993                 /* A lost lock - don't even consider delegations */
994                 goto out;
995         /* returns true if delegation stateid found and copied */
996         if (nfs4_copy_delegation_stateid(dst, state->inode, fmode)) {
997                 ret = 0;
998                 goto out;
999         }
1000         if (ret != -ENOENT)
1001                 /* nfs4_copy_delegation_stateid() didn't over-write
1002                  * dst, so it still has the lock stateid which we now
1003                  * choose to use.
1004                  */
1005                 goto out;
1006         nfs4_copy_open_stateid(dst, state);
1007         ret = 0;
1008 out:
1009         if (nfs_server_capable(state->inode, NFS_CAP_STATEID_NFSV41))
1010                 dst->seqid = 0;
1011         return ret;
1012 }
1013
1014 struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask)
1015 {
1016         struct nfs_seqid *new;
1017
1018         new = kmalloc(sizeof(*new), gfp_mask);
1019         if (new == NULL)
1020                 return ERR_PTR(-ENOMEM);
1021         new->sequence = counter;
1022         INIT_LIST_HEAD(&new->list);
1023         new->task = NULL;
1024         return new;
1025 }
1026
1027 void nfs_release_seqid(struct nfs_seqid *seqid)
1028 {
1029         struct nfs_seqid_counter *sequence;
1030
1031         if (seqid == NULL || list_empty(&seqid->list))
1032                 return;
1033         sequence = seqid->sequence;
1034         spin_lock(&sequence->lock);
1035         list_del_init(&seqid->list);
1036         if (!list_empty(&sequence->list)) {
1037                 struct nfs_seqid *next;
1038
1039                 next = list_first_entry(&sequence->list,
1040                                 struct nfs_seqid, list);
1041                 rpc_wake_up_queued_task(&sequence->wait, next->task);
1042         }
1043         spin_unlock(&sequence->lock);
1044 }
1045
1046 void nfs_free_seqid(struct nfs_seqid *seqid)
1047 {
1048         nfs_release_seqid(seqid);
1049         kfree(seqid);
1050 }
1051
1052 /*
1053  * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
1054  * failed with a seqid incrementing error -
1055  * see comments nfs4.h:seqid_mutating_error()
1056  */
1057 static void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
1058 {
1059         switch (status) {
1060                 case 0:
1061                         break;
1062                 case -NFS4ERR_BAD_SEQID:
1063                         if (seqid->sequence->flags & NFS_SEQID_CONFIRMED)
1064                                 return;
1065                         pr_warn_ratelimited("NFS: v4 server returned a bad"
1066                                         " sequence-id error on an"
1067                                         " unconfirmed sequence %p!\n",
1068                                         seqid->sequence);
1069                 case -NFS4ERR_STALE_CLIENTID:
1070                 case -NFS4ERR_STALE_STATEID:
1071                 case -NFS4ERR_BAD_STATEID:
1072                 case -NFS4ERR_BADXDR:
1073                 case -NFS4ERR_RESOURCE:
1074                 case -NFS4ERR_NOFILEHANDLE:
1075                         /* Non-seqid mutating errors */
1076                         return;
1077         };
1078         /*
1079          * Note: no locking needed as we are guaranteed to be first
1080          * on the sequence list
1081          */
1082         seqid->sequence->counter++;
1083 }
1084
1085 void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
1086 {
1087         struct nfs4_state_owner *sp;
1088
1089         if (seqid == NULL)
1090                 return;
1091
1092         sp = container_of(seqid->sequence, struct nfs4_state_owner, so_seqid);
1093         if (status == -NFS4ERR_BAD_SEQID)
1094                 nfs4_drop_state_owner(sp);
1095         if (!nfs4_has_session(sp->so_server->nfs_client))
1096                 nfs_increment_seqid(status, seqid);
1097 }
1098
1099 /*
1100  * Increment the seqid if the LOCK/LOCKU succeeded, or
1101  * failed with a seqid incrementing error -
1102  * see comments nfs4.h:seqid_mutating_error()
1103  */
1104 void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
1105 {
1106         if (seqid != NULL)
1107                 nfs_increment_seqid(status, seqid);
1108 }
1109
1110 int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
1111 {
1112         struct nfs_seqid_counter *sequence;
1113         int status = 0;
1114
1115         if (seqid == NULL)
1116                 goto out;
1117         sequence = seqid->sequence;
1118         spin_lock(&sequence->lock);
1119         seqid->task = task;
1120         if (list_empty(&seqid->list))
1121                 list_add_tail(&seqid->list, &sequence->list);
1122         if (list_first_entry(&sequence->list, struct nfs_seqid, list) == seqid)
1123                 goto unlock;
1124         rpc_sleep_on(&sequence->wait, task, NULL);
1125         status = -EAGAIN;
1126 unlock:
1127         spin_unlock(&sequence->lock);
1128 out:
1129         return status;
1130 }
1131
1132 static int nfs4_run_state_manager(void *);
1133
1134 static void nfs4_clear_state_manager_bit(struct nfs_client *clp)
1135 {
1136         smp_mb__before_atomic();
1137         clear_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state);
1138         smp_mb__after_atomic();
1139         wake_up_bit(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING);
1140         rpc_wake_up(&clp->cl_rpcwaitq);
1141 }
1142
1143 /*
1144  * Schedule the nfs_client asynchronous state management routine
1145  */
1146 void nfs4_schedule_state_manager(struct nfs_client *clp)
1147 {
1148         struct task_struct *task;
1149         char buf[INET6_ADDRSTRLEN + sizeof("-manager") + 1];
1150
1151         if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
1152                 return;
1153         __module_get(THIS_MODULE);
1154         atomic_inc(&clp->cl_count);
1155
1156         /* The rcu_read_lock() is not strictly necessary, as the state
1157          * manager is the only thread that ever changes the rpc_xprt
1158          * after it's initialized.  At this point, we're single threaded. */
1159         rcu_read_lock();
1160         snprintf(buf, sizeof(buf), "%s-manager",
1161                         rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
1162         rcu_read_unlock();
1163         task = kthread_run(nfs4_run_state_manager, clp, "%s", buf);
1164         if (IS_ERR(task)) {
1165                 printk(KERN_ERR "%s: kthread_run: %ld\n",
1166                         __func__, PTR_ERR(task));
1167                 nfs4_clear_state_manager_bit(clp);
1168                 nfs_put_client(clp);
1169                 module_put(THIS_MODULE);
1170         }
1171 }
1172
1173 /*
1174  * Schedule a lease recovery attempt
1175  */
1176 void nfs4_schedule_lease_recovery(struct nfs_client *clp)
1177 {
1178         if (!clp)
1179                 return;
1180         if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1181                 set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1182         dprintk("%s: scheduling lease recovery for server %s\n", __func__,
1183                         clp->cl_hostname);
1184         nfs4_schedule_state_manager(clp);
1185 }
1186 EXPORT_SYMBOL_GPL(nfs4_schedule_lease_recovery);
1187
1188 /**
1189  * nfs4_schedule_migration_recovery - trigger migration recovery
1190  *
1191  * @server: FSID that is migrating
1192  *
1193  * Returns zero if recovery has started, otherwise a negative NFS4ERR
1194  * value is returned.
1195  */
1196 int nfs4_schedule_migration_recovery(const struct nfs_server *server)
1197 {
1198         struct nfs_client *clp = server->nfs_client;
1199
1200         if (server->fh_expire_type != NFS4_FH_PERSISTENT) {
1201                 pr_err("NFS: volatile file handles not supported (server %s)\n",
1202                                 clp->cl_hostname);
1203                 return -NFS4ERR_IO;
1204         }
1205
1206         if (test_bit(NFS_MIG_FAILED, &server->mig_status))
1207                 return -NFS4ERR_IO;
1208
1209         dprintk("%s: scheduling migration recovery for (%llx:%llx) on %s\n",
1210                         __func__,
1211                         (unsigned long long)server->fsid.major,
1212                         (unsigned long long)server->fsid.minor,
1213                         clp->cl_hostname);
1214
1215         set_bit(NFS_MIG_IN_TRANSITION,
1216                         &((struct nfs_server *)server)->mig_status);
1217         set_bit(NFS4CLNT_MOVED, &clp->cl_state);
1218
1219         nfs4_schedule_state_manager(clp);
1220         return 0;
1221 }
1222 EXPORT_SYMBOL_GPL(nfs4_schedule_migration_recovery);
1223
1224 /**
1225  * nfs4_schedule_lease_moved_recovery - start lease-moved recovery
1226  *
1227  * @clp: server to check for moved leases
1228  *
1229  */
1230 void nfs4_schedule_lease_moved_recovery(struct nfs_client *clp)
1231 {
1232         dprintk("%s: scheduling lease-moved recovery for client ID %llx on %s\n",
1233                 __func__, clp->cl_clientid, clp->cl_hostname);
1234
1235         set_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state);
1236         nfs4_schedule_state_manager(clp);
1237 }
1238 EXPORT_SYMBOL_GPL(nfs4_schedule_lease_moved_recovery);
1239
1240 int nfs4_wait_clnt_recover(struct nfs_client *clp)
1241 {
1242         int res;
1243
1244         might_sleep();
1245
1246         atomic_inc(&clp->cl_count);
1247         res = wait_on_bit_action(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING,
1248                                  nfs_wait_bit_killable, TASK_KILLABLE);
1249         if (res)
1250                 goto out;
1251         if (clp->cl_cons_state < 0)
1252                 res = clp->cl_cons_state;
1253 out:
1254         nfs_put_client(clp);
1255         return res;
1256 }
1257
1258 int nfs4_client_recover_expired_lease(struct nfs_client *clp)
1259 {
1260         unsigned int loop;
1261         int ret;
1262
1263         for (loop = NFS4_MAX_LOOP_ON_RECOVER; loop != 0; loop--) {
1264                 ret = nfs4_wait_clnt_recover(clp);
1265                 if (ret != 0)
1266                         break;
1267                 if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) &&
1268                     !test_bit(NFS4CLNT_CHECK_LEASE,&clp->cl_state))
1269                         break;
1270                 nfs4_schedule_state_manager(clp);
1271                 ret = -EIO;
1272         }
1273         return ret;
1274 }
1275
1276 /*
1277  * nfs40_handle_cb_pathdown - return all delegations after NFS4ERR_CB_PATH_DOWN
1278  * @clp: client to process
1279  *
1280  * Set the NFS4CLNT_LEASE_EXPIRED state in order to force a
1281  * resend of the SETCLIENTID and hence re-establish the
1282  * callback channel. Then return all existing delegations.
1283  */
1284 static void nfs40_handle_cb_pathdown(struct nfs_client *clp)
1285 {
1286         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1287         nfs_expire_all_delegations(clp);
1288         dprintk("%s: handling CB_PATHDOWN recovery for server %s\n", __func__,
1289                         clp->cl_hostname);
1290 }
1291
1292 void nfs4_schedule_path_down_recovery(struct nfs_client *clp)
1293 {
1294         nfs40_handle_cb_pathdown(clp);
1295         nfs4_schedule_state_manager(clp);
1296 }
1297
1298 static int nfs4_state_mark_reclaim_reboot(struct nfs_client *clp, struct nfs4_state *state)
1299 {
1300
1301         set_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1302         /* Don't recover state that expired before the reboot */
1303         if (test_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags)) {
1304                 clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1305                 return 0;
1306         }
1307         set_bit(NFS_OWNER_RECLAIM_REBOOT, &state->owner->so_flags);
1308         set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1309         return 1;
1310 }
1311
1312 int nfs4_state_mark_reclaim_nograce(struct nfs_client *clp, struct nfs4_state *state)
1313 {
1314         set_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
1315         clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1316         set_bit(NFS_OWNER_RECLAIM_NOGRACE, &state->owner->so_flags);
1317         set_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
1318         return 1;
1319 }
1320
1321 int nfs4_schedule_stateid_recovery(const struct nfs_server *server, struct nfs4_state *state)
1322 {
1323         struct nfs_client *clp = server->nfs_client;
1324
1325         if (!nfs4_valid_open_stateid(state))
1326                 return -EBADF;
1327         nfs4_state_mark_reclaim_nograce(clp, state);
1328         dprintk("%s: scheduling stateid recovery for server %s\n", __func__,
1329                         clp->cl_hostname);
1330         nfs4_schedule_state_manager(clp);
1331         return 0;
1332 }
1333 EXPORT_SYMBOL_GPL(nfs4_schedule_stateid_recovery);
1334
1335 void nfs_inode_find_state_and_recover(struct inode *inode,
1336                 const nfs4_stateid *stateid)
1337 {
1338         struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
1339         struct nfs_inode *nfsi = NFS_I(inode);
1340         struct nfs_open_context *ctx;
1341         struct nfs4_state *state;
1342         bool found = false;
1343
1344         spin_lock(&inode->i_lock);
1345         list_for_each_entry(ctx, &nfsi->open_files, list) {
1346                 state = ctx->state;
1347                 if (state == NULL)
1348                         continue;
1349                 if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
1350                         continue;
1351                 if (!nfs4_stateid_match(&state->stateid, stateid))
1352                         continue;
1353                 nfs4_state_mark_reclaim_nograce(clp, state);
1354                 found = true;
1355         }
1356         spin_unlock(&inode->i_lock);
1357         if (found)
1358                 nfs4_schedule_state_manager(clp);
1359 }
1360
1361 static void nfs4_state_mark_open_context_bad(struct nfs4_state *state)
1362 {
1363         struct inode *inode = state->inode;
1364         struct nfs_inode *nfsi = NFS_I(inode);
1365         struct nfs_open_context *ctx;
1366
1367         spin_lock(&inode->i_lock);
1368         list_for_each_entry(ctx, &nfsi->open_files, list) {
1369                 if (ctx->state != state)
1370                         continue;
1371                 set_bit(NFS_CONTEXT_BAD, &ctx->flags);
1372         }
1373         spin_unlock(&inode->i_lock);
1374 }
1375
1376 static void nfs4_state_mark_recovery_failed(struct nfs4_state *state, int error)
1377 {
1378         set_bit(NFS_STATE_RECOVERY_FAILED, &state->flags);
1379         nfs4_state_mark_open_context_bad(state);
1380 }
1381
1382
1383 static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_recovery_ops *ops)
1384 {
1385         struct inode *inode = state->inode;
1386         struct nfs_inode *nfsi = NFS_I(inode);
1387         struct file_lock *fl;
1388         int status = 0;
1389         struct file_lock_context *flctx = inode->i_flctx;
1390         struct list_head *list;
1391
1392         if (flctx == NULL)
1393                 return 0;
1394
1395         list = &flctx->flc_posix;
1396
1397         /* Guard against delegation returns and new lock/unlock calls */
1398         down_write(&nfsi->rwsem);
1399         spin_lock(&flctx->flc_lock);
1400 restart:
1401         list_for_each_entry(fl, list, fl_list) {
1402                 if (nfs_file_open_context(fl->fl_file)->state != state)
1403                         continue;
1404                 spin_unlock(&flctx->flc_lock);
1405                 status = ops->recover_lock(state, fl);
1406                 switch (status) {
1407                 case 0:
1408                         break;
1409                 case -ESTALE:
1410                 case -NFS4ERR_ADMIN_REVOKED:
1411                 case -NFS4ERR_STALE_STATEID:
1412                 case -NFS4ERR_BAD_STATEID:
1413                 case -NFS4ERR_EXPIRED:
1414                 case -NFS4ERR_NO_GRACE:
1415                 case -NFS4ERR_STALE_CLIENTID:
1416                 case -NFS4ERR_BADSESSION:
1417                 case -NFS4ERR_BADSLOT:
1418                 case -NFS4ERR_BAD_HIGH_SLOT:
1419                 case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1420                         goto out;
1421                 default:
1422                         pr_err("NFS: %s: unhandled error %d\n",
1423                                         __func__, status);
1424                 case -ENOMEM:
1425                 case -NFS4ERR_DENIED:
1426                 case -NFS4ERR_RECLAIM_BAD:
1427                 case -NFS4ERR_RECLAIM_CONFLICT:
1428                         /* kill_proc(fl->fl_pid, SIGLOST, 1); */
1429                         status = 0;
1430                 }
1431                 spin_lock(&flctx->flc_lock);
1432         }
1433         if (list == &flctx->flc_posix) {
1434                 list = &flctx->flc_flock;
1435                 goto restart;
1436         }
1437         spin_unlock(&flctx->flc_lock);
1438 out:
1439         up_write(&nfsi->rwsem);
1440         return status;
1441 }
1442
1443 static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp, const struct nfs4_state_recovery_ops *ops)
1444 {
1445         struct nfs4_state *state;
1446         struct nfs4_lock_state *lock;
1447         int status = 0;
1448
1449         /* Note: we rely on the sp->so_states list being ordered 
1450          * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
1451          * states first.
1452          * This is needed to ensure that the server won't give us any
1453          * read delegations that we have to return if, say, we are
1454          * recovering after a network partition or a reboot from a
1455          * server that doesn't support a grace period.
1456          */
1457         spin_lock(&sp->so_lock);
1458         raw_write_seqcount_begin(&sp->so_reclaim_seqcount);
1459 restart:
1460         list_for_each_entry(state, &sp->so_states, open_states) {
1461                 if (!test_and_clear_bit(ops->state_flag_bit, &state->flags))
1462                         continue;
1463                 if (!nfs4_valid_open_stateid(state))
1464                         continue;
1465                 if (state->state == 0)
1466                         continue;
1467                 atomic_inc(&state->count);
1468                 spin_unlock(&sp->so_lock);
1469                 status = ops->recover_open(sp, state);
1470                 if (status >= 0) {
1471                         status = nfs4_reclaim_locks(state, ops);
1472                         if (status >= 0) {
1473                                 if (!test_bit(NFS_DELEGATED_STATE, &state->flags)) {
1474                                         spin_lock(&state->state_lock);
1475                                         list_for_each_entry(lock, &state->lock_states, ls_locks) {
1476                                                 if (!test_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags))
1477                                                         pr_warn_ratelimited("NFS: "
1478                                                                             "%s: Lock reclaim "
1479                                                                             "failed!\n", __func__);
1480                                         }
1481                                         spin_unlock(&state->state_lock);
1482                                 }
1483                                 nfs4_put_open_state(state);
1484                                 clear_bit(NFS_STATE_RECLAIM_NOGRACE,
1485                                         &state->flags);
1486                                 spin_lock(&sp->so_lock);
1487                                 goto restart;
1488                         }
1489                 }
1490                 switch (status) {
1491                         default:
1492                                 printk(KERN_ERR "NFS: %s: unhandled error %d\n",
1493                                         __func__, status);
1494                         case -ENOENT:
1495                         case -ENOMEM:
1496                         case -EACCES:
1497                         case -EROFS:
1498                         case -EIO:
1499                         case -ESTALE:
1500                                 /* Open state on this file cannot be recovered */
1501                                 nfs4_state_mark_recovery_failed(state, status);
1502                                 break;
1503                         case -EAGAIN:
1504                                 ssleep(1);
1505                         case -NFS4ERR_ADMIN_REVOKED:
1506                         case -NFS4ERR_STALE_STATEID:
1507                         case -NFS4ERR_BAD_STATEID:
1508                         case -NFS4ERR_RECLAIM_BAD:
1509                         case -NFS4ERR_RECLAIM_CONFLICT:
1510                                 nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1511                                 break;
1512                         case -NFS4ERR_EXPIRED:
1513                         case -NFS4ERR_NO_GRACE:
1514                                 nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1515                         case -NFS4ERR_STALE_CLIENTID:
1516                         case -NFS4ERR_BADSESSION:
1517                         case -NFS4ERR_BADSLOT:
1518                         case -NFS4ERR_BAD_HIGH_SLOT:
1519                         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1520                                 goto out_err;
1521                 }
1522                 nfs4_put_open_state(state);
1523                 spin_lock(&sp->so_lock);
1524                 goto restart;
1525         }
1526         raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1527         spin_unlock(&sp->so_lock);
1528         return 0;
1529 out_err:
1530         nfs4_put_open_state(state);
1531         spin_lock(&sp->so_lock);
1532         raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1533         spin_unlock(&sp->so_lock);
1534         return status;
1535 }
1536
1537 static void nfs4_clear_open_state(struct nfs4_state *state)
1538 {
1539         struct nfs4_lock_state *lock;
1540
1541         clear_bit(NFS_DELEGATED_STATE, &state->flags);
1542         clear_bit(NFS_O_RDONLY_STATE, &state->flags);
1543         clear_bit(NFS_O_WRONLY_STATE, &state->flags);
1544         clear_bit(NFS_O_RDWR_STATE, &state->flags);
1545         spin_lock(&state->state_lock);
1546         list_for_each_entry(lock, &state->lock_states, ls_locks) {
1547                 lock->ls_seqid.flags = 0;
1548                 clear_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags);
1549         }
1550         spin_unlock(&state->state_lock);
1551 }
1552
1553 static void nfs4_reset_seqids(struct nfs_server *server,
1554         int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1555 {
1556         struct nfs_client *clp = server->nfs_client;
1557         struct nfs4_state_owner *sp;
1558         struct rb_node *pos;
1559         struct nfs4_state *state;
1560
1561         spin_lock(&clp->cl_lock);
1562         for (pos = rb_first(&server->state_owners);
1563              pos != NULL;
1564              pos = rb_next(pos)) {
1565                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1566                 sp->so_seqid.flags = 0;
1567                 spin_lock(&sp->so_lock);
1568                 list_for_each_entry(state, &sp->so_states, open_states) {
1569                         if (mark_reclaim(clp, state))
1570                                 nfs4_clear_open_state(state);
1571                 }
1572                 spin_unlock(&sp->so_lock);
1573         }
1574         spin_unlock(&clp->cl_lock);
1575 }
1576
1577 static void nfs4_state_mark_reclaim_helper(struct nfs_client *clp,
1578         int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1579 {
1580         struct nfs_server *server;
1581
1582         rcu_read_lock();
1583         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1584                 nfs4_reset_seqids(server, mark_reclaim);
1585         rcu_read_unlock();
1586 }
1587
1588 static void nfs4_state_start_reclaim_reboot(struct nfs_client *clp)
1589 {
1590         /* Mark all delegations for reclaim */
1591         nfs_delegation_mark_reclaim(clp);
1592         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_reboot);
1593 }
1594
1595 static void nfs4_reclaim_complete(struct nfs_client *clp,
1596                                  const struct nfs4_state_recovery_ops *ops,
1597                                  struct rpc_cred *cred)
1598 {
1599         /* Notify the server we're done reclaiming our state */
1600         if (ops->reclaim_complete)
1601                 (void)ops->reclaim_complete(clp, cred);
1602 }
1603
1604 static void nfs4_clear_reclaim_server(struct nfs_server *server)
1605 {
1606         struct nfs_client *clp = server->nfs_client;
1607         struct nfs4_state_owner *sp;
1608         struct rb_node *pos;
1609         struct nfs4_state *state;
1610
1611         spin_lock(&clp->cl_lock);
1612         for (pos = rb_first(&server->state_owners);
1613              pos != NULL;
1614              pos = rb_next(pos)) {
1615                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1616                 spin_lock(&sp->so_lock);
1617                 list_for_each_entry(state, &sp->so_states, open_states) {
1618                         if (!test_and_clear_bit(NFS_STATE_RECLAIM_REBOOT,
1619                                                 &state->flags))
1620                                 continue;
1621                         nfs4_state_mark_reclaim_nograce(clp, state);
1622                 }
1623                 spin_unlock(&sp->so_lock);
1624         }
1625         spin_unlock(&clp->cl_lock);
1626 }
1627
1628 static int nfs4_state_clear_reclaim_reboot(struct nfs_client *clp)
1629 {
1630         struct nfs_server *server;
1631
1632         if (!test_and_clear_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
1633                 return 0;
1634
1635         rcu_read_lock();
1636         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1637                 nfs4_clear_reclaim_server(server);
1638         rcu_read_unlock();
1639
1640         nfs_delegation_reap_unclaimed(clp);
1641         return 1;
1642 }
1643
1644 static void nfs4_state_end_reclaim_reboot(struct nfs_client *clp)
1645 {
1646         const struct nfs4_state_recovery_ops *ops;
1647         struct rpc_cred *cred;
1648
1649         if (!nfs4_state_clear_reclaim_reboot(clp))
1650                 return;
1651         ops = clp->cl_mvops->reboot_recovery_ops;
1652         cred = nfs4_get_clid_cred(clp);
1653         nfs4_reclaim_complete(clp, ops, cred);
1654         put_rpccred(cred);
1655 }
1656
1657 static void nfs_delegation_clear_all(struct nfs_client *clp)
1658 {
1659         nfs_delegation_mark_reclaim(clp);
1660         nfs_delegation_reap_unclaimed(clp);
1661 }
1662
1663 static void nfs4_state_start_reclaim_nograce(struct nfs_client *clp)
1664 {
1665         nfs_delegation_clear_all(clp);
1666         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_nograce);
1667 }
1668
1669 static int nfs4_recovery_handle_error(struct nfs_client *clp, int error)
1670 {
1671         switch (error) {
1672                 case 0:
1673                         break;
1674                 case -NFS4ERR_CB_PATH_DOWN:
1675                         nfs40_handle_cb_pathdown(clp);
1676                         break;
1677                 case -NFS4ERR_NO_GRACE:
1678                         nfs4_state_end_reclaim_reboot(clp);
1679                         break;
1680                 case -NFS4ERR_STALE_CLIENTID:
1681                         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1682                         nfs4_state_clear_reclaim_reboot(clp);
1683                         nfs4_state_start_reclaim_reboot(clp);
1684                         break;
1685                 case -NFS4ERR_EXPIRED:
1686                         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1687                         nfs4_state_start_reclaim_nograce(clp);
1688                         break;
1689                 case -NFS4ERR_BADSESSION:
1690                 case -NFS4ERR_BADSLOT:
1691                 case -NFS4ERR_BAD_HIGH_SLOT:
1692                 case -NFS4ERR_DEADSESSION:
1693                 case -NFS4ERR_SEQ_FALSE_RETRY:
1694                 case -NFS4ERR_SEQ_MISORDERED:
1695                         set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
1696                         /* Zero session reset errors */
1697                         break;
1698                 case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1699                         set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
1700                         break;
1701                 default:
1702                         dprintk("%s: failed to handle error %d for server %s\n",
1703                                         __func__, error, clp->cl_hostname);
1704                         return error;
1705         }
1706         dprintk("%s: handled error %d for server %s\n", __func__, error,
1707                         clp->cl_hostname);
1708         return 0;
1709 }
1710
1711 static int nfs4_do_reclaim(struct nfs_client *clp, const struct nfs4_state_recovery_ops *ops)
1712 {
1713         struct nfs4_state_owner *sp;
1714         struct nfs_server *server;
1715         struct rb_node *pos;
1716         int status = 0;
1717
1718 restart:
1719         rcu_read_lock();
1720         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
1721                 nfs4_purge_state_owners(server);
1722                 spin_lock(&clp->cl_lock);
1723                 for (pos = rb_first(&server->state_owners);
1724                      pos != NULL;
1725                      pos = rb_next(pos)) {
1726                         sp = rb_entry(pos,
1727                                 struct nfs4_state_owner, so_server_node);
1728                         if (!test_and_clear_bit(ops->owner_flag_bit,
1729                                                         &sp->so_flags))
1730                                 continue;
1731                         if (!atomic_inc_not_zero(&sp->so_count))
1732                                 continue;
1733                         spin_unlock(&clp->cl_lock);
1734                         rcu_read_unlock();
1735
1736                         status = nfs4_reclaim_open_state(sp, ops);
1737                         if (status < 0) {
1738                                 set_bit(ops->owner_flag_bit, &sp->so_flags);
1739                                 nfs4_put_state_owner(sp);
1740                                 status = nfs4_recovery_handle_error(clp, status);
1741                                 return (status != 0) ? status : -EAGAIN;
1742                         }
1743
1744                         nfs4_put_state_owner(sp);
1745                         goto restart;
1746                 }
1747                 spin_unlock(&clp->cl_lock);
1748         }
1749         rcu_read_unlock();
1750         return 0;
1751 }
1752
1753 static int nfs4_check_lease(struct nfs_client *clp)
1754 {
1755         struct rpc_cred *cred;
1756         const struct nfs4_state_maintenance_ops *ops =
1757                 clp->cl_mvops->state_renewal_ops;
1758         int status;
1759
1760         /* Is the client already known to have an expired lease? */
1761         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1762                 return 0;
1763         spin_lock(&clp->cl_lock);
1764         cred = ops->get_state_renewal_cred_locked(clp);
1765         spin_unlock(&clp->cl_lock);
1766         if (cred == NULL) {
1767                 cred = nfs4_get_clid_cred(clp);
1768                 status = -ENOKEY;
1769                 if (cred == NULL)
1770                         goto out;
1771         }
1772         status = ops->renew_lease(clp, cred);
1773         put_rpccred(cred);
1774         if (status == -ETIMEDOUT) {
1775                 set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1776                 return 0;
1777         }
1778 out:
1779         return nfs4_recovery_handle_error(clp, status);
1780 }
1781
1782 /* Set NFS4CLNT_LEASE_EXPIRED and reclaim reboot state for all v4.0 errors
1783  * and for recoverable errors on EXCHANGE_ID for v4.1
1784  */
1785 static int nfs4_handle_reclaim_lease_error(struct nfs_client *clp, int status)
1786 {
1787         switch (status) {
1788         case -NFS4ERR_SEQ_MISORDERED:
1789                 if (test_and_set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state))
1790                         return -ESERVERFAULT;
1791                 /* Lease confirmation error: retry after purging the lease */
1792                 ssleep(1);
1793                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1794                 break;
1795         case -NFS4ERR_STALE_CLIENTID:
1796                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1797                 nfs4_state_start_reclaim_reboot(clp);
1798                 break;
1799         case -NFS4ERR_CLID_INUSE:
1800                 pr_err("NFS: Server %s reports our clientid is in use\n",
1801                         clp->cl_hostname);
1802                 nfs_mark_client_ready(clp, -EPERM);
1803                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1804                 return -EPERM;
1805         case -EACCES:
1806         case -NFS4ERR_DELAY:
1807         case -ETIMEDOUT:
1808         case -EAGAIN:
1809                 ssleep(1);
1810                 break;
1811
1812         case -NFS4ERR_MINOR_VERS_MISMATCH:
1813                 if (clp->cl_cons_state == NFS_CS_SESSION_INITING)
1814                         nfs_mark_client_ready(clp, -EPROTONOSUPPORT);
1815                 dprintk("%s: exit with error %d for server %s\n",
1816                                 __func__, -EPROTONOSUPPORT, clp->cl_hostname);
1817                 return -EPROTONOSUPPORT;
1818         case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
1819                                  * in nfs4_exchange_id */
1820         default:
1821                 dprintk("%s: exit with error %d for server %s\n", __func__,
1822                                 status, clp->cl_hostname);
1823                 return status;
1824         }
1825         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1826         dprintk("%s: handled error %d for server %s\n", __func__, status,
1827                         clp->cl_hostname);
1828         return 0;
1829 }
1830
1831 static int nfs4_establish_lease(struct nfs_client *clp)
1832 {
1833         struct rpc_cred *cred;
1834         const struct nfs4_state_recovery_ops *ops =
1835                 clp->cl_mvops->reboot_recovery_ops;
1836         int status;
1837
1838         nfs4_begin_drain_session(clp);
1839         cred = nfs4_get_clid_cred(clp);
1840         if (cred == NULL)
1841                 return -ENOENT;
1842         status = ops->establish_clid(clp, cred);
1843         put_rpccred(cred);
1844         if (status != 0)
1845                 return status;
1846         pnfs_destroy_all_layouts(clp);
1847         return 0;
1848 }
1849
1850 /*
1851  * Returns zero or a negative errno.  NFS4ERR values are converted
1852  * to local errno values.
1853  */
1854 static int nfs4_reclaim_lease(struct nfs_client *clp)
1855 {
1856         int status;
1857
1858         status = nfs4_establish_lease(clp);
1859         if (status < 0)
1860                 return nfs4_handle_reclaim_lease_error(clp, status);
1861         if (test_and_clear_bit(NFS4CLNT_SERVER_SCOPE_MISMATCH, &clp->cl_state))
1862                 nfs4_state_start_reclaim_nograce(clp);
1863         if (!test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state))
1864                 set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1865         clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1866         clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1867         return 0;
1868 }
1869
1870 static int nfs4_purge_lease(struct nfs_client *clp)
1871 {
1872         int status;
1873
1874         status = nfs4_establish_lease(clp);
1875         if (status < 0)
1876                 return nfs4_handle_reclaim_lease_error(clp, status);
1877         clear_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
1878         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1879         nfs4_state_start_reclaim_nograce(clp);
1880         return 0;
1881 }
1882
1883 /*
1884  * Try remote migration of one FSID from a source server to a
1885  * destination server.  The source server provides a list of
1886  * potential destinations.
1887  *
1888  * Returns zero or a negative NFS4ERR status code.
1889  */
1890 static int nfs4_try_migration(struct nfs_server *server, struct rpc_cred *cred)
1891 {
1892         struct nfs_client *clp = server->nfs_client;
1893         struct nfs4_fs_locations *locations = NULL;
1894         struct inode *inode;
1895         struct page *page;
1896         int status, result;
1897
1898         dprintk("--> %s: FSID %llx:%llx on \"%s\"\n", __func__,
1899                         (unsigned long long)server->fsid.major,
1900                         (unsigned long long)server->fsid.minor,
1901                         clp->cl_hostname);
1902
1903         result = 0;
1904         page = alloc_page(GFP_KERNEL);
1905         locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
1906         if (page == NULL || locations == NULL) {
1907                 dprintk("<-- %s: no memory\n", __func__);
1908                 goto out;
1909         }
1910
1911         inode = d_inode(server->super->s_root);
1912         result = nfs4_proc_get_locations(inode, locations, page, cred);
1913         if (result) {
1914                 dprintk("<-- %s: failed to retrieve fs_locations: %d\n",
1915                         __func__, result);
1916                 goto out;
1917         }
1918
1919         result = -NFS4ERR_NXIO;
1920         if (!(locations->fattr.valid & NFS_ATTR_FATTR_V4_LOCATIONS)) {
1921                 dprintk("<-- %s: No fs_locations data, migration skipped\n",
1922                         __func__);
1923                 goto out;
1924         }
1925
1926         nfs4_begin_drain_session(clp);
1927
1928         status = nfs4_replace_transport(server, locations);
1929         if (status != 0) {
1930                 dprintk("<-- %s: failed to replace transport: %d\n",
1931                         __func__, status);
1932                 goto out;
1933         }
1934
1935         result = 0;
1936         dprintk("<-- %s: migration succeeded\n", __func__);
1937
1938 out:
1939         if (page != NULL)
1940                 __free_page(page);
1941         kfree(locations);
1942         if (result) {
1943                 pr_err("NFS: migration recovery failed (server %s)\n",
1944                                 clp->cl_hostname);
1945                 set_bit(NFS_MIG_FAILED, &server->mig_status);
1946         }
1947         return result;
1948 }
1949
1950 /*
1951  * Returns zero or a negative NFS4ERR status code.
1952  */
1953 static int nfs4_handle_migration(struct nfs_client *clp)
1954 {
1955         const struct nfs4_state_maintenance_ops *ops =
1956                                 clp->cl_mvops->state_renewal_ops;
1957         struct nfs_server *server;
1958         struct rpc_cred *cred;
1959
1960         dprintk("%s: migration reported on \"%s\"\n", __func__,
1961                         clp->cl_hostname);
1962
1963         spin_lock(&clp->cl_lock);
1964         cred = ops->get_state_renewal_cred_locked(clp);
1965         spin_unlock(&clp->cl_lock);
1966         if (cred == NULL)
1967                 return -NFS4ERR_NOENT;
1968
1969         clp->cl_mig_gen++;
1970 restart:
1971         rcu_read_lock();
1972         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
1973                 int status;
1974
1975                 if (server->mig_gen == clp->cl_mig_gen)
1976                         continue;
1977                 server->mig_gen = clp->cl_mig_gen;
1978
1979                 if (!test_and_clear_bit(NFS_MIG_IN_TRANSITION,
1980                                                 &server->mig_status))
1981                         continue;
1982
1983                 rcu_read_unlock();
1984                 status = nfs4_try_migration(server, cred);
1985                 if (status < 0) {
1986                         put_rpccred(cred);
1987                         return status;
1988                 }
1989                 goto restart;
1990         }
1991         rcu_read_unlock();
1992         put_rpccred(cred);
1993         return 0;
1994 }
1995
1996 /*
1997  * Test each nfs_server on the clp's cl_superblocks list to see
1998  * if it's moved to another server.  Stop when the server no longer
1999  * returns NFS4ERR_LEASE_MOVED.
2000  */
2001 static int nfs4_handle_lease_moved(struct nfs_client *clp)
2002 {
2003         const struct nfs4_state_maintenance_ops *ops =
2004                                 clp->cl_mvops->state_renewal_ops;
2005         struct nfs_server *server;
2006         struct rpc_cred *cred;
2007
2008         dprintk("%s: lease moved reported on \"%s\"\n", __func__,
2009                         clp->cl_hostname);
2010
2011         spin_lock(&clp->cl_lock);
2012         cred = ops->get_state_renewal_cred_locked(clp);
2013         spin_unlock(&clp->cl_lock);
2014         if (cred == NULL)
2015                 return -NFS4ERR_NOENT;
2016
2017         clp->cl_mig_gen++;
2018 restart:
2019         rcu_read_lock();
2020         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
2021                 struct inode *inode;
2022                 int status;
2023
2024                 if (server->mig_gen == clp->cl_mig_gen)
2025                         continue;
2026                 server->mig_gen = clp->cl_mig_gen;
2027
2028                 rcu_read_unlock();
2029
2030                 inode = d_inode(server->super->s_root);
2031                 status = nfs4_proc_fsid_present(inode, cred);
2032                 if (status != -NFS4ERR_MOVED)
2033                         goto restart;   /* wasn't this one */
2034                 if (nfs4_try_migration(server, cred) == -NFS4ERR_LEASE_MOVED)
2035                         goto restart;   /* there are more */
2036                 goto out;
2037         }
2038         rcu_read_unlock();
2039
2040 out:
2041         put_rpccred(cred);
2042         return 0;
2043 }
2044
2045 /**
2046  * nfs4_discover_server_trunking - Detect server IP address trunking
2047  *
2048  * @clp: nfs_client under test
2049  * @result: OUT: found nfs_client, or clp
2050  *
2051  * Returns zero or a negative errno.  If zero is returned,
2052  * an nfs_client pointer is planted in "result".
2053  *
2054  * Note: since we are invoked in process context, and
2055  * not from inside the state manager, we cannot use
2056  * nfs4_handle_reclaim_lease_error().
2057  */
2058 int nfs4_discover_server_trunking(struct nfs_client *clp,
2059                                   struct nfs_client **result)
2060 {
2061         const struct nfs4_state_recovery_ops *ops =
2062                                 clp->cl_mvops->reboot_recovery_ops;
2063         struct rpc_clnt *clnt;
2064         struct rpc_cred *cred;
2065         int i, status;
2066
2067         dprintk("NFS: %s: testing '%s'\n", __func__, clp->cl_hostname);
2068
2069         clnt = clp->cl_rpcclient;
2070         i = 0;
2071
2072         mutex_lock(&nfs_clid_init_mutex);
2073 again:
2074         status  = -ENOENT;
2075         cred = nfs4_get_clid_cred(clp);
2076         if (cred == NULL)
2077                 goto out_unlock;
2078
2079         status = ops->detect_trunking(clp, result, cred);
2080         put_rpccred(cred);
2081         switch (status) {
2082         case 0:
2083                 break;
2084         case -ETIMEDOUT:
2085                 if (clnt->cl_softrtry)
2086                         break;
2087         case -NFS4ERR_DELAY:
2088         case -EAGAIN:
2089                 ssleep(1);
2090         case -NFS4ERR_STALE_CLIENTID:
2091                 dprintk("NFS: %s after status %d, retrying\n",
2092                         __func__, status);
2093                 goto again;
2094         case -EACCES:
2095                 if (i++ == 0) {
2096                         nfs4_root_machine_cred(clp);
2097                         goto again;
2098                 }
2099                 if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX)
2100                         break;
2101         case -NFS4ERR_CLID_INUSE:
2102         case -NFS4ERR_WRONGSEC:
2103                 /* No point in retrying if we already used RPC_AUTH_UNIX */
2104                 if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX) {
2105                         status = -EPERM;
2106                         break;
2107                 }
2108                 clnt = rpc_clone_client_set_auth(clnt, RPC_AUTH_UNIX);
2109                 if (IS_ERR(clnt)) {
2110                         status = PTR_ERR(clnt);
2111                         break;
2112                 }
2113                 /* Note: this is safe because we haven't yet marked the
2114                  * client as ready, so we are the only user of
2115                  * clp->cl_rpcclient
2116                  */
2117                 clnt = xchg(&clp->cl_rpcclient, clnt);
2118                 rpc_shutdown_client(clnt);
2119                 clnt = clp->cl_rpcclient;
2120                 goto again;
2121
2122         case -NFS4ERR_MINOR_VERS_MISMATCH:
2123                 status = -EPROTONOSUPPORT;
2124                 break;
2125
2126         case -EKEYEXPIRED:
2127         case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
2128                                  * in nfs4_exchange_id */
2129                 status = -EKEYEXPIRED;
2130                 break;
2131         default:
2132                 pr_warn("NFS: %s unhandled error %d. Exiting with error EIO\n",
2133                                 __func__, status);
2134                 status = -EIO;
2135         }
2136
2137 out_unlock:
2138         mutex_unlock(&nfs_clid_init_mutex);
2139         dprintk("NFS: %s: status = %d\n", __func__, status);
2140         return status;
2141 }
2142
2143 #ifdef CONFIG_NFS_V4_1
2144 void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
2145 {
2146         struct nfs_client *clp = session->clp;
2147
2148         switch (err) {
2149         default:
2150                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2151                 break;
2152         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
2153                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2154         }
2155         nfs4_schedule_lease_recovery(clp);
2156 }
2157 EXPORT_SYMBOL_GPL(nfs4_schedule_session_recovery);
2158
2159 void nfs41_notify_server(struct nfs_client *clp)
2160 {
2161         /* Use CHECK_LEASE to ping the server with a SEQUENCE */
2162         set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
2163         nfs4_schedule_state_manager(clp);
2164 }
2165
2166 static void nfs4_reset_all_state(struct nfs_client *clp)
2167 {
2168         if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2169                 set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
2170                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
2171                 nfs4_state_start_reclaim_nograce(clp);
2172                 dprintk("%s: scheduling reset of all state for server %s!\n",
2173                                 __func__, clp->cl_hostname);
2174                 nfs4_schedule_state_manager(clp);
2175         }
2176 }
2177
2178 static void nfs41_handle_server_reboot(struct nfs_client *clp)
2179 {
2180         if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2181                 nfs4_state_start_reclaim_reboot(clp);
2182                 dprintk("%s: server %s rebooted!\n", __func__,
2183                                 clp->cl_hostname);
2184                 nfs4_schedule_state_manager(clp);
2185         }
2186 }
2187
2188 static void nfs41_handle_all_state_revoked(struct nfs_client *clp)
2189 {
2190         nfs4_reset_all_state(clp);
2191         dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2192 }
2193
2194 static void nfs41_handle_some_state_revoked(struct nfs_client *clp)
2195 {
2196         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_nograce);
2197         nfs4_schedule_state_manager(clp);
2198
2199         dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2200 }
2201
2202 static void nfs41_handle_recallable_state_revoked(struct nfs_client *clp)
2203 {
2204         /* FIXME: For now, we destroy all layouts. */
2205         pnfs_destroy_all_layouts(clp);
2206         /* FIXME: For now, we test all delegations+open state+locks. */
2207         nfs41_handle_some_state_revoked(clp);
2208         dprintk("%s: Recallable state revoked on server %s!\n", __func__,
2209                         clp->cl_hostname);
2210 }
2211
2212 static void nfs41_handle_backchannel_fault(struct nfs_client *clp)
2213 {
2214         set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2215         nfs4_schedule_state_manager(clp);
2216
2217         dprintk("%s: server %s declared a backchannel fault\n", __func__,
2218                         clp->cl_hostname);
2219 }
2220
2221 static void nfs41_handle_cb_path_down(struct nfs_client *clp)
2222 {
2223         if (test_and_set_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2224                 &clp->cl_state) == 0)
2225                 nfs4_schedule_state_manager(clp);
2226 }
2227
2228 void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags)
2229 {
2230         if (!flags)
2231                 return;
2232
2233         dprintk("%s: \"%s\" (client ID %llx) flags=0x%08x\n",
2234                 __func__, clp->cl_hostname, clp->cl_clientid, flags);
2235
2236         if (flags & SEQ4_STATUS_RESTART_RECLAIM_NEEDED)
2237                 nfs41_handle_server_reboot(clp);
2238         if (flags & (SEQ4_STATUS_EXPIRED_ALL_STATE_REVOKED))
2239                 nfs41_handle_all_state_revoked(clp);
2240         if (flags & (SEQ4_STATUS_EXPIRED_SOME_STATE_REVOKED |
2241                             SEQ4_STATUS_ADMIN_STATE_REVOKED))
2242                 nfs41_handle_some_state_revoked(clp);
2243         if (flags & SEQ4_STATUS_LEASE_MOVED)
2244                 nfs4_schedule_lease_moved_recovery(clp);
2245         if (flags & SEQ4_STATUS_RECALLABLE_STATE_REVOKED)
2246                 nfs41_handle_recallable_state_revoked(clp);
2247         if (flags & SEQ4_STATUS_BACKCHANNEL_FAULT)
2248                 nfs41_handle_backchannel_fault(clp);
2249         else if (flags & (SEQ4_STATUS_CB_PATH_DOWN |
2250                                 SEQ4_STATUS_CB_PATH_DOWN_SESSION))
2251                 nfs41_handle_cb_path_down(clp);
2252 }
2253
2254 static int nfs4_reset_session(struct nfs_client *clp)
2255 {
2256         struct rpc_cred *cred;
2257         int status;
2258
2259         if (!nfs4_has_session(clp))
2260                 return 0;
2261         nfs4_begin_drain_session(clp);
2262         cred = nfs4_get_clid_cred(clp);
2263         status = nfs4_proc_destroy_session(clp->cl_session, cred);
2264         switch (status) {
2265         case 0:
2266         case -NFS4ERR_BADSESSION:
2267         case -NFS4ERR_DEADSESSION:
2268                 break;
2269         case -NFS4ERR_BACK_CHAN_BUSY:
2270         case -NFS4ERR_DELAY:
2271                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2272                 status = 0;
2273                 ssleep(1);
2274                 goto out;
2275         default:
2276                 status = nfs4_recovery_handle_error(clp, status);
2277                 goto out;
2278         }
2279
2280         memset(clp->cl_session->sess_id.data, 0, NFS4_MAX_SESSIONID_LEN);
2281         status = nfs4_proc_create_session(clp, cred);
2282         if (status) {
2283                 dprintk("%s: session reset failed with status %d for server %s!\n",
2284                         __func__, status, clp->cl_hostname);
2285                 status = nfs4_handle_reclaim_lease_error(clp, status);
2286                 goto out;
2287         }
2288         nfs41_finish_session_reset(clp);
2289         dprintk("%s: session reset was successful for server %s!\n",
2290                         __func__, clp->cl_hostname);
2291 out:
2292         if (cred)
2293                 put_rpccred(cred);
2294         return status;
2295 }
2296
2297 static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2298 {
2299         struct rpc_cred *cred;
2300         int ret;
2301
2302         if (!nfs4_has_session(clp))
2303                 return 0;
2304         nfs4_begin_drain_session(clp);
2305         cred = nfs4_get_clid_cred(clp);
2306         ret = nfs4_proc_bind_conn_to_session(clp, cred);
2307         if (cred)
2308                 put_rpccred(cred);
2309         clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2310         switch (ret) {
2311         case 0:
2312                 dprintk("%s: bind_conn_to_session was successful for server %s!\n",
2313                         __func__, clp->cl_hostname);
2314                 break;
2315         case -NFS4ERR_DELAY:
2316                 ssleep(1);
2317                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2318                 break;
2319         default:
2320                 return nfs4_recovery_handle_error(clp, ret);
2321         }
2322         return 0;
2323 }
2324 #else /* CONFIG_NFS_V4_1 */
2325 static int nfs4_reset_session(struct nfs_client *clp) { return 0; }
2326
2327 static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2328 {
2329         return 0;
2330 }
2331 #endif /* CONFIG_NFS_V4_1 */
2332
2333 static void nfs4_state_manager(struct nfs_client *clp)
2334 {
2335         int status = 0;
2336         const char *section = "", *section_sep = "";
2337
2338         /* Ensure exclusive access to NFSv4 state */
2339         do {
2340                 if (test_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state)) {
2341                         section = "purge state";
2342                         status = nfs4_purge_lease(clp);
2343                         if (status < 0)
2344                                 goto out_error;
2345                         continue;
2346                 }
2347
2348                 if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state)) {
2349                         section = "lease expired";
2350                         /* We're going to have to re-establish a clientid */
2351                         status = nfs4_reclaim_lease(clp);
2352                         if (status < 0)
2353                                 goto out_error;
2354                         continue;
2355                 }
2356
2357                 /* Initialize or reset the session */
2358                 if (test_and_clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state)) {
2359                         section = "reset session";
2360                         status = nfs4_reset_session(clp);
2361                         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
2362                                 continue;
2363                         if (status < 0)
2364                                 goto out_error;
2365                 }
2366
2367                 /* Send BIND_CONN_TO_SESSION */
2368                 if (test_and_clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2369                                 &clp->cl_state)) {
2370                         section = "bind conn to session";
2371                         status = nfs4_bind_conn_to_session(clp);
2372                         if (status < 0)
2373                                 goto out_error;
2374                         continue;
2375                 }
2376
2377                 if (test_and_clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state)) {
2378                         section = "check lease";
2379                         status = nfs4_check_lease(clp);
2380                         if (status < 0)
2381                                 goto out_error;
2382                         continue;
2383                 }
2384
2385                 if (test_and_clear_bit(NFS4CLNT_MOVED, &clp->cl_state)) {
2386                         section = "migration";
2387                         status = nfs4_handle_migration(clp);
2388                         if (status < 0)
2389                                 goto out_error;
2390                 }
2391
2392                 if (test_and_clear_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state)) {
2393                         section = "lease moved";
2394                         status = nfs4_handle_lease_moved(clp);
2395                         if (status < 0)
2396                                 goto out_error;
2397                 }
2398
2399                 /* First recover reboot state... */
2400                 if (test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state)) {
2401                         section = "reclaim reboot";
2402                         status = nfs4_do_reclaim(clp,
2403                                 clp->cl_mvops->reboot_recovery_ops);
2404                         if (status == -EAGAIN)
2405                                 continue;
2406                         if (status < 0)
2407                                 goto out_error;
2408                         nfs4_state_end_reclaim_reboot(clp);
2409                 }
2410
2411                 /* Now recover expired state... */
2412                 if (test_and_clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state)) {
2413                         section = "reclaim nograce";
2414                         status = nfs4_do_reclaim(clp,
2415                                 clp->cl_mvops->nograce_recovery_ops);
2416                         if (status == -EAGAIN)
2417                                 continue;
2418                         if (status < 0)
2419                                 goto out_error;
2420                 }
2421
2422                 nfs4_end_drain_session(clp);
2423                 if (test_and_clear_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) {
2424                         nfs_client_return_marked_delegations(clp);
2425                         continue;
2426                 }
2427
2428                 nfs4_clear_state_manager_bit(clp);
2429                 /* Did we race with an attempt to give us more work? */
2430                 if (clp->cl_state == 0)
2431                         break;
2432                 if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
2433                         break;
2434         } while (atomic_read(&clp->cl_count) > 1);
2435         return;
2436 out_error:
2437         if (strlen(section))
2438                 section_sep = ": ";
2439         pr_warn_ratelimited("NFS: state manager%s%s failed on NFSv4 server %s"
2440                         " with error %d\n", section_sep, section,
2441                         clp->cl_hostname, -status);
2442         ssleep(1);
2443         nfs4_end_drain_session(clp);
2444         nfs4_clear_state_manager_bit(clp);
2445 }
2446
2447 static int nfs4_run_state_manager(void *ptr)
2448 {
2449         struct nfs_client *clp = ptr;
2450
2451         allow_signal(SIGKILL);
2452         nfs4_state_manager(clp);
2453         nfs_put_client(clp);
2454         module_put_and_exit(0);
2455         return 0;
2456 }
2457
2458 /*
2459  * Local variables:
2460  *  c-basic-offset: 8
2461  * End:
2462  */