Merge tag 'kvm-arm-for-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm...
[firefly-linux-kernel-4.4.55.git] / fs / nfs / nfs4state.c
1 /*
2  *  fs/nfs/nfs4state.c
3  *
4  *  Client-side XDR for NFSv4.
5  *
6  *  Copyright (c) 2002 The Regents of the University of Michigan.
7  *  All rights reserved.
8  *
9  *  Kendrick Smith <kmsmith@umich.edu>
10  *
11  *  Redistribution and use in source and binary forms, with or without
12  *  modification, are permitted provided that the following conditions
13  *  are met:
14  *
15  *  1. Redistributions of source code must retain the above copyright
16  *     notice, this list of conditions and the following disclaimer.
17  *  2. Redistributions in binary form must reproduce the above copyright
18  *     notice, this list of conditions and the following disclaimer in the
19  *     documentation and/or other materials provided with the distribution.
20  *  3. Neither the name of the University nor the names of its
21  *     contributors may be used to endorse or promote products derived
22  *     from this software without specific prior written permission.
23  *
24  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
25  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
26  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
27  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
29  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
30  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
31  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
32  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
33  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
34  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
35  *
36  * Implementation of the NFSv4 state model.  For the time being,
37  * this is minimal, but will be made much more complex in a
38  * subsequent patch.
39  */
40
41 #include <linux/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 -ESTALE:
1497                                 /* Open state on this file cannot be recovered */
1498                                 nfs4_state_mark_recovery_failed(state, status);
1499                                 break;
1500                         case -EAGAIN:
1501                                 ssleep(1);
1502                         case -NFS4ERR_ADMIN_REVOKED:
1503                         case -NFS4ERR_STALE_STATEID:
1504                         case -NFS4ERR_BAD_STATEID:
1505                         case -NFS4ERR_RECLAIM_BAD:
1506                         case -NFS4ERR_RECLAIM_CONFLICT:
1507                                 nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1508                                 break;
1509                         case -NFS4ERR_EXPIRED:
1510                         case -NFS4ERR_NO_GRACE:
1511                                 nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1512                         case -NFS4ERR_STALE_CLIENTID:
1513                         case -NFS4ERR_BADSESSION:
1514                         case -NFS4ERR_BADSLOT:
1515                         case -NFS4ERR_BAD_HIGH_SLOT:
1516                         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1517                                 goto out_err;
1518                 }
1519                 nfs4_put_open_state(state);
1520                 spin_lock(&sp->so_lock);
1521                 goto restart;
1522         }
1523         raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1524         spin_unlock(&sp->so_lock);
1525         return 0;
1526 out_err:
1527         nfs4_put_open_state(state);
1528         spin_lock(&sp->so_lock);
1529         raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1530         spin_unlock(&sp->so_lock);
1531         return status;
1532 }
1533
1534 static void nfs4_clear_open_state(struct nfs4_state *state)
1535 {
1536         struct nfs4_lock_state *lock;
1537
1538         clear_bit(NFS_DELEGATED_STATE, &state->flags);
1539         clear_bit(NFS_O_RDONLY_STATE, &state->flags);
1540         clear_bit(NFS_O_WRONLY_STATE, &state->flags);
1541         clear_bit(NFS_O_RDWR_STATE, &state->flags);
1542         spin_lock(&state->state_lock);
1543         list_for_each_entry(lock, &state->lock_states, ls_locks) {
1544                 lock->ls_seqid.flags = 0;
1545                 clear_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags);
1546         }
1547         spin_unlock(&state->state_lock);
1548 }
1549
1550 static void nfs4_reset_seqids(struct nfs_server *server,
1551         int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1552 {
1553         struct nfs_client *clp = server->nfs_client;
1554         struct nfs4_state_owner *sp;
1555         struct rb_node *pos;
1556         struct nfs4_state *state;
1557
1558         spin_lock(&clp->cl_lock);
1559         for (pos = rb_first(&server->state_owners);
1560              pos != NULL;
1561              pos = rb_next(pos)) {
1562                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1563                 sp->so_seqid.flags = 0;
1564                 spin_lock(&sp->so_lock);
1565                 list_for_each_entry(state, &sp->so_states, open_states) {
1566                         if (mark_reclaim(clp, state))
1567                                 nfs4_clear_open_state(state);
1568                 }
1569                 spin_unlock(&sp->so_lock);
1570         }
1571         spin_unlock(&clp->cl_lock);
1572 }
1573
1574 static void nfs4_state_mark_reclaim_helper(struct nfs_client *clp,
1575         int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1576 {
1577         struct nfs_server *server;
1578
1579         rcu_read_lock();
1580         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1581                 nfs4_reset_seqids(server, mark_reclaim);
1582         rcu_read_unlock();
1583 }
1584
1585 static void nfs4_state_start_reclaim_reboot(struct nfs_client *clp)
1586 {
1587         /* Mark all delegations for reclaim */
1588         nfs_delegation_mark_reclaim(clp);
1589         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_reboot);
1590 }
1591
1592 static void nfs4_reclaim_complete(struct nfs_client *clp,
1593                                  const struct nfs4_state_recovery_ops *ops,
1594                                  struct rpc_cred *cred)
1595 {
1596         /* Notify the server we're done reclaiming our state */
1597         if (ops->reclaim_complete)
1598                 (void)ops->reclaim_complete(clp, cred);
1599 }
1600
1601 static void nfs4_clear_reclaim_server(struct nfs_server *server)
1602 {
1603         struct nfs_client *clp = server->nfs_client;
1604         struct nfs4_state_owner *sp;
1605         struct rb_node *pos;
1606         struct nfs4_state *state;
1607
1608         spin_lock(&clp->cl_lock);
1609         for (pos = rb_first(&server->state_owners);
1610              pos != NULL;
1611              pos = rb_next(pos)) {
1612                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1613                 spin_lock(&sp->so_lock);
1614                 list_for_each_entry(state, &sp->so_states, open_states) {
1615                         if (!test_and_clear_bit(NFS_STATE_RECLAIM_REBOOT,
1616                                                 &state->flags))
1617                                 continue;
1618                         nfs4_state_mark_reclaim_nograce(clp, state);
1619                 }
1620                 spin_unlock(&sp->so_lock);
1621         }
1622         spin_unlock(&clp->cl_lock);
1623 }
1624
1625 static int nfs4_state_clear_reclaim_reboot(struct nfs_client *clp)
1626 {
1627         struct nfs_server *server;
1628
1629         if (!test_and_clear_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
1630                 return 0;
1631
1632         rcu_read_lock();
1633         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1634                 nfs4_clear_reclaim_server(server);
1635         rcu_read_unlock();
1636
1637         nfs_delegation_reap_unclaimed(clp);
1638         return 1;
1639 }
1640
1641 static void nfs4_state_end_reclaim_reboot(struct nfs_client *clp)
1642 {
1643         const struct nfs4_state_recovery_ops *ops;
1644         struct rpc_cred *cred;
1645
1646         if (!nfs4_state_clear_reclaim_reboot(clp))
1647                 return;
1648         ops = clp->cl_mvops->reboot_recovery_ops;
1649         cred = nfs4_get_clid_cred(clp);
1650         nfs4_reclaim_complete(clp, ops, cred);
1651         put_rpccred(cred);
1652 }
1653
1654 static void nfs_delegation_clear_all(struct nfs_client *clp)
1655 {
1656         nfs_delegation_mark_reclaim(clp);
1657         nfs_delegation_reap_unclaimed(clp);
1658 }
1659
1660 static void nfs4_state_start_reclaim_nograce(struct nfs_client *clp)
1661 {
1662         nfs_delegation_clear_all(clp);
1663         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_nograce);
1664 }
1665
1666 static int nfs4_recovery_handle_error(struct nfs_client *clp, int error)
1667 {
1668         switch (error) {
1669                 case 0:
1670                         break;
1671                 case -NFS4ERR_CB_PATH_DOWN:
1672                         nfs40_handle_cb_pathdown(clp);
1673                         break;
1674                 case -NFS4ERR_NO_GRACE:
1675                         nfs4_state_end_reclaim_reboot(clp);
1676                         break;
1677                 case -NFS4ERR_STALE_CLIENTID:
1678                         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1679                         nfs4_state_clear_reclaim_reboot(clp);
1680                         nfs4_state_start_reclaim_reboot(clp);
1681                         break;
1682                 case -NFS4ERR_EXPIRED:
1683                         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1684                         nfs4_state_start_reclaim_nograce(clp);
1685                         break;
1686                 case -NFS4ERR_BADSESSION:
1687                 case -NFS4ERR_BADSLOT:
1688                 case -NFS4ERR_BAD_HIGH_SLOT:
1689                 case -NFS4ERR_DEADSESSION:
1690                 case -NFS4ERR_SEQ_FALSE_RETRY:
1691                 case -NFS4ERR_SEQ_MISORDERED:
1692                         set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
1693                         /* Zero session reset errors */
1694                         break;
1695                 case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1696                         set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
1697                         break;
1698                 default:
1699                         dprintk("%s: failed to handle error %d for server %s\n",
1700                                         __func__, error, clp->cl_hostname);
1701                         return error;
1702         }
1703         dprintk("%s: handled error %d for server %s\n", __func__, error,
1704                         clp->cl_hostname);
1705         return 0;
1706 }
1707
1708 static int nfs4_do_reclaim(struct nfs_client *clp, const struct nfs4_state_recovery_ops *ops)
1709 {
1710         struct nfs4_state_owner *sp;
1711         struct nfs_server *server;
1712         struct rb_node *pos;
1713         int status = 0;
1714
1715 restart:
1716         rcu_read_lock();
1717         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
1718                 nfs4_purge_state_owners(server);
1719                 spin_lock(&clp->cl_lock);
1720                 for (pos = rb_first(&server->state_owners);
1721                      pos != NULL;
1722                      pos = rb_next(pos)) {
1723                         sp = rb_entry(pos,
1724                                 struct nfs4_state_owner, so_server_node);
1725                         if (!test_and_clear_bit(ops->owner_flag_bit,
1726                                                         &sp->so_flags))
1727                                 continue;
1728                         atomic_inc(&sp->so_count);
1729                         spin_unlock(&clp->cl_lock);
1730                         rcu_read_unlock();
1731
1732                         status = nfs4_reclaim_open_state(sp, ops);
1733                         if (status < 0) {
1734                                 set_bit(ops->owner_flag_bit, &sp->so_flags);
1735                                 nfs4_put_state_owner(sp);
1736                                 status = nfs4_recovery_handle_error(clp, status);
1737                                 return (status != 0) ? status : -EAGAIN;
1738                         }
1739
1740                         nfs4_put_state_owner(sp);
1741                         goto restart;
1742                 }
1743                 spin_unlock(&clp->cl_lock);
1744         }
1745         rcu_read_unlock();
1746         return 0;
1747 }
1748
1749 static int nfs4_check_lease(struct nfs_client *clp)
1750 {
1751         struct rpc_cred *cred;
1752         const struct nfs4_state_maintenance_ops *ops =
1753                 clp->cl_mvops->state_renewal_ops;
1754         int status;
1755
1756         /* Is the client already known to have an expired lease? */
1757         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1758                 return 0;
1759         spin_lock(&clp->cl_lock);
1760         cred = ops->get_state_renewal_cred_locked(clp);
1761         spin_unlock(&clp->cl_lock);
1762         if (cred == NULL) {
1763                 cred = nfs4_get_clid_cred(clp);
1764                 status = -ENOKEY;
1765                 if (cred == NULL)
1766                         goto out;
1767         }
1768         status = ops->renew_lease(clp, cred);
1769         put_rpccred(cred);
1770         if (status == -ETIMEDOUT) {
1771                 set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1772                 return 0;
1773         }
1774 out:
1775         return nfs4_recovery_handle_error(clp, status);
1776 }
1777
1778 /* Set NFS4CLNT_LEASE_EXPIRED and reclaim reboot state for all v4.0 errors
1779  * and for recoverable errors on EXCHANGE_ID for v4.1
1780  */
1781 static int nfs4_handle_reclaim_lease_error(struct nfs_client *clp, int status)
1782 {
1783         switch (status) {
1784         case -NFS4ERR_SEQ_MISORDERED:
1785                 if (test_and_set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state))
1786                         return -ESERVERFAULT;
1787                 /* Lease confirmation error: retry after purging the lease */
1788                 ssleep(1);
1789                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1790                 break;
1791         case -NFS4ERR_STALE_CLIENTID:
1792                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1793                 nfs4_state_start_reclaim_reboot(clp);
1794                 break;
1795         case -NFS4ERR_CLID_INUSE:
1796                 pr_err("NFS: Server %s reports our clientid is in use\n",
1797                         clp->cl_hostname);
1798                 nfs_mark_client_ready(clp, -EPERM);
1799                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1800                 return -EPERM;
1801         case -EACCES:
1802         case -NFS4ERR_DELAY:
1803         case -ETIMEDOUT:
1804         case -EAGAIN:
1805                 ssleep(1);
1806                 break;
1807
1808         case -NFS4ERR_MINOR_VERS_MISMATCH:
1809                 if (clp->cl_cons_state == NFS_CS_SESSION_INITING)
1810                         nfs_mark_client_ready(clp, -EPROTONOSUPPORT);
1811                 dprintk("%s: exit with error %d for server %s\n",
1812                                 __func__, -EPROTONOSUPPORT, clp->cl_hostname);
1813                 return -EPROTONOSUPPORT;
1814         case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
1815                                  * in nfs4_exchange_id */
1816         default:
1817                 dprintk("%s: exit with error %d for server %s\n", __func__,
1818                                 status, clp->cl_hostname);
1819                 return status;
1820         }
1821         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1822         dprintk("%s: handled error %d for server %s\n", __func__, status,
1823                         clp->cl_hostname);
1824         return 0;
1825 }
1826
1827 static int nfs4_establish_lease(struct nfs_client *clp)
1828 {
1829         struct rpc_cred *cred;
1830         const struct nfs4_state_recovery_ops *ops =
1831                 clp->cl_mvops->reboot_recovery_ops;
1832         int status;
1833
1834         nfs4_begin_drain_session(clp);
1835         cred = nfs4_get_clid_cred(clp);
1836         if (cred == NULL)
1837                 return -ENOENT;
1838         status = ops->establish_clid(clp, cred);
1839         put_rpccred(cred);
1840         if (status != 0)
1841                 return status;
1842         pnfs_destroy_all_layouts(clp);
1843         return 0;
1844 }
1845
1846 /*
1847  * Returns zero or a negative errno.  NFS4ERR values are converted
1848  * to local errno values.
1849  */
1850 static int nfs4_reclaim_lease(struct nfs_client *clp)
1851 {
1852         int status;
1853
1854         status = nfs4_establish_lease(clp);
1855         if (status < 0)
1856                 return nfs4_handle_reclaim_lease_error(clp, status);
1857         if (test_and_clear_bit(NFS4CLNT_SERVER_SCOPE_MISMATCH, &clp->cl_state))
1858                 nfs4_state_start_reclaim_nograce(clp);
1859         if (!test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state))
1860                 set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1861         clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1862         clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1863         return 0;
1864 }
1865
1866 static int nfs4_purge_lease(struct nfs_client *clp)
1867 {
1868         int status;
1869
1870         status = nfs4_establish_lease(clp);
1871         if (status < 0)
1872                 return nfs4_handle_reclaim_lease_error(clp, status);
1873         clear_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
1874         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1875         nfs4_state_start_reclaim_nograce(clp);
1876         return 0;
1877 }
1878
1879 /*
1880  * Try remote migration of one FSID from a source server to a
1881  * destination server.  The source server provides a list of
1882  * potential destinations.
1883  *
1884  * Returns zero or a negative NFS4ERR status code.
1885  */
1886 static int nfs4_try_migration(struct nfs_server *server, struct rpc_cred *cred)
1887 {
1888         struct nfs_client *clp = server->nfs_client;
1889         struct nfs4_fs_locations *locations = NULL;
1890         struct inode *inode;
1891         struct page *page;
1892         int status, result;
1893
1894         dprintk("--> %s: FSID %llx:%llx on \"%s\"\n", __func__,
1895                         (unsigned long long)server->fsid.major,
1896                         (unsigned long long)server->fsid.minor,
1897                         clp->cl_hostname);
1898
1899         result = 0;
1900         page = alloc_page(GFP_KERNEL);
1901         locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
1902         if (page == NULL || locations == NULL) {
1903                 dprintk("<-- %s: no memory\n", __func__);
1904                 goto out;
1905         }
1906
1907         inode = d_inode(server->super->s_root);
1908         result = nfs4_proc_get_locations(inode, locations, page, cred);
1909         if (result) {
1910                 dprintk("<-- %s: failed to retrieve fs_locations: %d\n",
1911                         __func__, result);
1912                 goto out;
1913         }
1914
1915         result = -NFS4ERR_NXIO;
1916         if (!(locations->fattr.valid & NFS_ATTR_FATTR_V4_LOCATIONS)) {
1917                 dprintk("<-- %s: No fs_locations data, migration skipped\n",
1918                         __func__);
1919                 goto out;
1920         }
1921
1922         nfs4_begin_drain_session(clp);
1923
1924         status = nfs4_replace_transport(server, locations);
1925         if (status != 0) {
1926                 dprintk("<-- %s: failed to replace transport: %d\n",
1927                         __func__, status);
1928                 goto out;
1929         }
1930
1931         result = 0;
1932         dprintk("<-- %s: migration succeeded\n", __func__);
1933
1934 out:
1935         if (page != NULL)
1936                 __free_page(page);
1937         kfree(locations);
1938         if (result) {
1939                 pr_err("NFS: migration recovery failed (server %s)\n",
1940                                 clp->cl_hostname);
1941                 set_bit(NFS_MIG_FAILED, &server->mig_status);
1942         }
1943         return result;
1944 }
1945
1946 /*
1947  * Returns zero or a negative NFS4ERR status code.
1948  */
1949 static int nfs4_handle_migration(struct nfs_client *clp)
1950 {
1951         const struct nfs4_state_maintenance_ops *ops =
1952                                 clp->cl_mvops->state_renewal_ops;
1953         struct nfs_server *server;
1954         struct rpc_cred *cred;
1955
1956         dprintk("%s: migration reported on \"%s\"\n", __func__,
1957                         clp->cl_hostname);
1958
1959         spin_lock(&clp->cl_lock);
1960         cred = ops->get_state_renewal_cred_locked(clp);
1961         spin_unlock(&clp->cl_lock);
1962         if (cred == NULL)
1963                 return -NFS4ERR_NOENT;
1964
1965         clp->cl_mig_gen++;
1966 restart:
1967         rcu_read_lock();
1968         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
1969                 int status;
1970
1971                 if (server->mig_gen == clp->cl_mig_gen)
1972                         continue;
1973                 server->mig_gen = clp->cl_mig_gen;
1974
1975                 if (!test_and_clear_bit(NFS_MIG_IN_TRANSITION,
1976                                                 &server->mig_status))
1977                         continue;
1978
1979                 rcu_read_unlock();
1980                 status = nfs4_try_migration(server, cred);
1981                 if (status < 0) {
1982                         put_rpccred(cred);
1983                         return status;
1984                 }
1985                 goto restart;
1986         }
1987         rcu_read_unlock();
1988         put_rpccred(cred);
1989         return 0;
1990 }
1991
1992 /*
1993  * Test each nfs_server on the clp's cl_superblocks list to see
1994  * if it's moved to another server.  Stop when the server no longer
1995  * returns NFS4ERR_LEASE_MOVED.
1996  */
1997 static int nfs4_handle_lease_moved(struct nfs_client *clp)
1998 {
1999         const struct nfs4_state_maintenance_ops *ops =
2000                                 clp->cl_mvops->state_renewal_ops;
2001         struct nfs_server *server;
2002         struct rpc_cred *cred;
2003
2004         dprintk("%s: lease moved reported on \"%s\"\n", __func__,
2005                         clp->cl_hostname);
2006
2007         spin_lock(&clp->cl_lock);
2008         cred = ops->get_state_renewal_cred_locked(clp);
2009         spin_unlock(&clp->cl_lock);
2010         if (cred == NULL)
2011                 return -NFS4ERR_NOENT;
2012
2013         clp->cl_mig_gen++;
2014 restart:
2015         rcu_read_lock();
2016         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
2017                 struct inode *inode;
2018                 int status;
2019
2020                 if (server->mig_gen == clp->cl_mig_gen)
2021                         continue;
2022                 server->mig_gen = clp->cl_mig_gen;
2023
2024                 rcu_read_unlock();
2025
2026                 inode = d_inode(server->super->s_root);
2027                 status = nfs4_proc_fsid_present(inode, cred);
2028                 if (status != -NFS4ERR_MOVED)
2029                         goto restart;   /* wasn't this one */
2030                 if (nfs4_try_migration(server, cred) == -NFS4ERR_LEASE_MOVED)
2031                         goto restart;   /* there are more */
2032                 goto out;
2033         }
2034         rcu_read_unlock();
2035
2036 out:
2037         put_rpccred(cred);
2038         return 0;
2039 }
2040
2041 /**
2042  * nfs4_discover_server_trunking - Detect server IP address trunking
2043  *
2044  * @clp: nfs_client under test
2045  * @result: OUT: found nfs_client, or clp
2046  *
2047  * Returns zero or a negative errno.  If zero is returned,
2048  * an nfs_client pointer is planted in "result".
2049  *
2050  * Note: since we are invoked in process context, and
2051  * not from inside the state manager, we cannot use
2052  * nfs4_handle_reclaim_lease_error().
2053  */
2054 int nfs4_discover_server_trunking(struct nfs_client *clp,
2055                                   struct nfs_client **result)
2056 {
2057         const struct nfs4_state_recovery_ops *ops =
2058                                 clp->cl_mvops->reboot_recovery_ops;
2059         struct rpc_clnt *clnt;
2060         struct rpc_cred *cred;
2061         int i, status;
2062
2063         dprintk("NFS: %s: testing '%s'\n", __func__, clp->cl_hostname);
2064
2065         clnt = clp->cl_rpcclient;
2066         i = 0;
2067
2068         mutex_lock(&nfs_clid_init_mutex);
2069 again:
2070         status  = -ENOENT;
2071         cred = nfs4_get_clid_cred(clp);
2072         if (cred == NULL)
2073                 goto out_unlock;
2074
2075         status = ops->detect_trunking(clp, result, cred);
2076         put_rpccred(cred);
2077         switch (status) {
2078         case 0:
2079                 break;
2080         case -ETIMEDOUT:
2081                 if (clnt->cl_softrtry)
2082                         break;
2083         case -NFS4ERR_DELAY:
2084         case -EAGAIN:
2085                 ssleep(1);
2086         case -NFS4ERR_STALE_CLIENTID:
2087                 dprintk("NFS: %s after status %d, retrying\n",
2088                         __func__, status);
2089                 goto again;
2090         case -EACCES:
2091                 if (i++ == 0) {
2092                         nfs4_root_machine_cred(clp);
2093                         goto again;
2094                 }
2095                 if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX)
2096                         break;
2097         case -NFS4ERR_CLID_INUSE:
2098         case -NFS4ERR_WRONGSEC:
2099                 /* No point in retrying if we already used RPC_AUTH_UNIX */
2100                 if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX) {
2101                         status = -EPERM;
2102                         break;
2103                 }
2104                 clnt = rpc_clone_client_set_auth(clnt, RPC_AUTH_UNIX);
2105                 if (IS_ERR(clnt)) {
2106                         status = PTR_ERR(clnt);
2107                         break;
2108                 }
2109                 /* Note: this is safe because we haven't yet marked the
2110                  * client as ready, so we are the only user of
2111                  * clp->cl_rpcclient
2112                  */
2113                 clnt = xchg(&clp->cl_rpcclient, clnt);
2114                 rpc_shutdown_client(clnt);
2115                 clnt = clp->cl_rpcclient;
2116                 goto again;
2117
2118         case -NFS4ERR_MINOR_VERS_MISMATCH:
2119                 status = -EPROTONOSUPPORT;
2120                 break;
2121
2122         case -EKEYEXPIRED:
2123         case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
2124                                  * in nfs4_exchange_id */
2125                 status = -EKEYEXPIRED;
2126                 break;
2127         default:
2128                 pr_warn("NFS: %s unhandled error %d. Exiting with error EIO\n",
2129                                 __func__, status);
2130                 status = -EIO;
2131         }
2132
2133 out_unlock:
2134         mutex_unlock(&nfs_clid_init_mutex);
2135         dprintk("NFS: %s: status = %d\n", __func__, status);
2136         return status;
2137 }
2138
2139 #ifdef CONFIG_NFS_V4_1
2140 void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
2141 {
2142         struct nfs_client *clp = session->clp;
2143
2144         switch (err) {
2145         default:
2146                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2147                 break;
2148         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
2149                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2150         }
2151         nfs4_schedule_lease_recovery(clp);
2152 }
2153 EXPORT_SYMBOL_GPL(nfs4_schedule_session_recovery);
2154
2155 void nfs41_notify_server(struct nfs_client *clp)
2156 {
2157         /* Use CHECK_LEASE to ping the server with a SEQUENCE */
2158         set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
2159         nfs4_schedule_state_manager(clp);
2160 }
2161
2162 static void nfs4_reset_all_state(struct nfs_client *clp)
2163 {
2164         if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2165                 set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
2166                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
2167                 nfs4_state_start_reclaim_nograce(clp);
2168                 dprintk("%s: scheduling reset of all state for server %s!\n",
2169                                 __func__, clp->cl_hostname);
2170                 nfs4_schedule_state_manager(clp);
2171         }
2172 }
2173
2174 static void nfs41_handle_server_reboot(struct nfs_client *clp)
2175 {
2176         if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2177                 nfs4_state_start_reclaim_reboot(clp);
2178                 dprintk("%s: server %s rebooted!\n", __func__,
2179                                 clp->cl_hostname);
2180                 nfs4_schedule_state_manager(clp);
2181         }
2182 }
2183
2184 static void nfs41_handle_all_state_revoked(struct nfs_client *clp)
2185 {
2186         nfs4_reset_all_state(clp);
2187         dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2188 }
2189
2190 static void nfs41_handle_some_state_revoked(struct nfs_client *clp)
2191 {
2192         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_nograce);
2193         nfs4_schedule_state_manager(clp);
2194
2195         dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2196 }
2197
2198 static void nfs41_handle_recallable_state_revoked(struct nfs_client *clp)
2199 {
2200         /* FIXME: For now, we destroy all layouts. */
2201         pnfs_destroy_all_layouts(clp);
2202         /* FIXME: For now, we test all delegations+open state+locks. */
2203         nfs41_handle_some_state_revoked(clp);
2204         dprintk("%s: Recallable state revoked on server %s!\n", __func__,
2205                         clp->cl_hostname);
2206 }
2207
2208 static void nfs41_handle_backchannel_fault(struct nfs_client *clp)
2209 {
2210         set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2211         nfs4_schedule_state_manager(clp);
2212
2213         dprintk("%s: server %s declared a backchannel fault\n", __func__,
2214                         clp->cl_hostname);
2215 }
2216
2217 static void nfs41_handle_cb_path_down(struct nfs_client *clp)
2218 {
2219         if (test_and_set_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2220                 &clp->cl_state) == 0)
2221                 nfs4_schedule_state_manager(clp);
2222 }
2223
2224 void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags)
2225 {
2226         if (!flags)
2227                 return;
2228
2229         dprintk("%s: \"%s\" (client ID %llx) flags=0x%08x\n",
2230                 __func__, clp->cl_hostname, clp->cl_clientid, flags);
2231
2232         if (flags & SEQ4_STATUS_RESTART_RECLAIM_NEEDED)
2233                 nfs41_handle_server_reboot(clp);
2234         if (flags & (SEQ4_STATUS_EXPIRED_ALL_STATE_REVOKED))
2235                 nfs41_handle_all_state_revoked(clp);
2236         if (flags & (SEQ4_STATUS_EXPIRED_SOME_STATE_REVOKED |
2237                             SEQ4_STATUS_ADMIN_STATE_REVOKED))
2238                 nfs41_handle_some_state_revoked(clp);
2239         if (flags & SEQ4_STATUS_LEASE_MOVED)
2240                 nfs4_schedule_lease_moved_recovery(clp);
2241         if (flags & SEQ4_STATUS_RECALLABLE_STATE_REVOKED)
2242                 nfs41_handle_recallable_state_revoked(clp);
2243         if (flags & SEQ4_STATUS_BACKCHANNEL_FAULT)
2244                 nfs41_handle_backchannel_fault(clp);
2245         else if (flags & (SEQ4_STATUS_CB_PATH_DOWN |
2246                                 SEQ4_STATUS_CB_PATH_DOWN_SESSION))
2247                 nfs41_handle_cb_path_down(clp);
2248 }
2249
2250 static int nfs4_reset_session(struct nfs_client *clp)
2251 {
2252         struct rpc_cred *cred;
2253         int status;
2254
2255         if (!nfs4_has_session(clp))
2256                 return 0;
2257         nfs4_begin_drain_session(clp);
2258         cred = nfs4_get_clid_cred(clp);
2259         status = nfs4_proc_destroy_session(clp->cl_session, cred);
2260         switch (status) {
2261         case 0:
2262         case -NFS4ERR_BADSESSION:
2263         case -NFS4ERR_DEADSESSION:
2264                 break;
2265         case -NFS4ERR_BACK_CHAN_BUSY:
2266         case -NFS4ERR_DELAY:
2267                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2268                 status = 0;
2269                 ssleep(1);
2270                 goto out;
2271         default:
2272                 status = nfs4_recovery_handle_error(clp, status);
2273                 goto out;
2274         }
2275
2276         memset(clp->cl_session->sess_id.data, 0, NFS4_MAX_SESSIONID_LEN);
2277         status = nfs4_proc_create_session(clp, cred);
2278         if (status) {
2279                 dprintk("%s: session reset failed with status %d for server %s!\n",
2280                         __func__, status, clp->cl_hostname);
2281                 status = nfs4_handle_reclaim_lease_error(clp, status);
2282                 goto out;
2283         }
2284         nfs41_finish_session_reset(clp);
2285         dprintk("%s: session reset was successful for server %s!\n",
2286                         __func__, clp->cl_hostname);
2287 out:
2288         if (cred)
2289                 put_rpccred(cred);
2290         return status;
2291 }
2292
2293 static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2294 {
2295         struct rpc_cred *cred;
2296         int ret;
2297
2298         if (!nfs4_has_session(clp))
2299                 return 0;
2300         nfs4_begin_drain_session(clp);
2301         cred = nfs4_get_clid_cred(clp);
2302         ret = nfs4_proc_bind_conn_to_session(clp, cred);
2303         if (cred)
2304                 put_rpccred(cred);
2305         clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2306         switch (ret) {
2307         case 0:
2308                 dprintk("%s: bind_conn_to_session was successful for server %s!\n",
2309                         __func__, clp->cl_hostname);
2310                 break;
2311         case -NFS4ERR_DELAY:
2312                 ssleep(1);
2313                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2314                 break;
2315         default:
2316                 return nfs4_recovery_handle_error(clp, ret);
2317         }
2318         return 0;
2319 }
2320 #else /* CONFIG_NFS_V4_1 */
2321 static int nfs4_reset_session(struct nfs_client *clp) { return 0; }
2322
2323 static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2324 {
2325         return 0;
2326 }
2327 #endif /* CONFIG_NFS_V4_1 */
2328
2329 static void nfs4_state_manager(struct nfs_client *clp)
2330 {
2331         int status = 0;
2332         const char *section = "", *section_sep = "";
2333
2334         /* Ensure exclusive access to NFSv4 state */
2335         do {
2336                 if (test_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state)) {
2337                         section = "purge state";
2338                         status = nfs4_purge_lease(clp);
2339                         if (status < 0)
2340                                 goto out_error;
2341                         continue;
2342                 }
2343
2344                 if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state)) {
2345                         section = "lease expired";
2346                         /* We're going to have to re-establish a clientid */
2347                         status = nfs4_reclaim_lease(clp);
2348                         if (status < 0)
2349                                 goto out_error;
2350                         continue;
2351                 }
2352
2353                 /* Initialize or reset the session */
2354                 if (test_and_clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state)) {
2355                         section = "reset session";
2356                         status = nfs4_reset_session(clp);
2357                         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
2358                                 continue;
2359                         if (status < 0)
2360                                 goto out_error;
2361                 }
2362
2363                 /* Send BIND_CONN_TO_SESSION */
2364                 if (test_and_clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2365                                 &clp->cl_state)) {
2366                         section = "bind conn to session";
2367                         status = nfs4_bind_conn_to_session(clp);
2368                         if (status < 0)
2369                                 goto out_error;
2370                         continue;
2371                 }
2372
2373                 if (test_and_clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state)) {
2374                         section = "check lease";
2375                         status = nfs4_check_lease(clp);
2376                         if (status < 0)
2377                                 goto out_error;
2378                         continue;
2379                 }
2380
2381                 if (test_and_clear_bit(NFS4CLNT_MOVED, &clp->cl_state)) {
2382                         section = "migration";
2383                         status = nfs4_handle_migration(clp);
2384                         if (status < 0)
2385                                 goto out_error;
2386                 }
2387
2388                 if (test_and_clear_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state)) {
2389                         section = "lease moved";
2390                         status = nfs4_handle_lease_moved(clp);
2391                         if (status < 0)
2392                                 goto out_error;
2393                 }
2394
2395                 /* First recover reboot state... */
2396                 if (test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state)) {
2397                         section = "reclaim reboot";
2398                         status = nfs4_do_reclaim(clp,
2399                                 clp->cl_mvops->reboot_recovery_ops);
2400                         if (status == -EAGAIN)
2401                                 continue;
2402                         if (status < 0)
2403                                 goto out_error;
2404                         nfs4_state_end_reclaim_reboot(clp);
2405                 }
2406
2407                 /* Now recover expired state... */
2408                 if (test_and_clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state)) {
2409                         section = "reclaim nograce";
2410                         status = nfs4_do_reclaim(clp,
2411                                 clp->cl_mvops->nograce_recovery_ops);
2412                         if (status == -EAGAIN)
2413                                 continue;
2414                         if (status < 0)
2415                                 goto out_error;
2416                 }
2417
2418                 nfs4_end_drain_session(clp);
2419                 if (test_and_clear_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) {
2420                         nfs_client_return_marked_delegations(clp);
2421                         continue;
2422                 }
2423
2424                 nfs4_clear_state_manager_bit(clp);
2425                 /* Did we race with an attempt to give us more work? */
2426                 if (clp->cl_state == 0)
2427                         break;
2428                 if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
2429                         break;
2430         } while (atomic_read(&clp->cl_count) > 1);
2431         return;
2432 out_error:
2433         if (strlen(section))
2434                 section_sep = ": ";
2435         pr_warn_ratelimited("NFS: state manager%s%s failed on NFSv4 server %s"
2436                         " with error %d\n", section_sep, section,
2437                         clp->cl_hostname, -status);
2438         ssleep(1);
2439         nfs4_end_drain_session(clp);
2440         nfs4_clear_state_manager_bit(clp);
2441 }
2442
2443 static int nfs4_run_state_manager(void *ptr)
2444 {
2445         struct nfs_client *clp = ptr;
2446
2447         allow_signal(SIGKILL);
2448         nfs4_state_manager(clp);
2449         nfs_put_client(clp);
2450         module_put_and_exit(0);
2451         return 0;
2452 }
2453
2454 /*
2455  * Local variables:
2456  *  c-basic-offset: 8
2457  * End:
2458  */