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Linux/fs/nfs/nfs4state.c

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  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         { .data = { 0 } },
 70         .type = NFS4_SPECIAL_STATEID_TYPE,
 71 };
 72 const nfs4_stateid invalid_stateid = {
 73         {
 74                 /* Funky initialiser keeps older gcc versions happy */
 75                 .data = { 0xff, 0xff, 0xff, 0xff, 0 },
 76         },
 77         .type = NFS4_INVALID_STATEID_TYPE,
 78 };
 79 
 80 const nfs4_stateid current_stateid = {
 81         {
 82                 /* Funky initialiser keeps older gcc versions happy */
 83                 .data = { 0x0, 0x0, 0x0, 0x1, 0 },
 84         },
 85         .type = NFS4_SPECIAL_STATEID_TYPE,
 86 };
 87 
 88 static DEFINE_MUTEX(nfs_clid_init_mutex);
 89 
 90 int nfs4_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
 91 {
 92         struct nfs4_setclientid_res clid = {
 93                 .clientid = clp->cl_clientid,
 94                 .confirm = clp->cl_confirm,
 95         };
 96         unsigned short port;
 97         int status;
 98         struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
 99 
100         if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
101                 goto do_confirm;
102         port = nn->nfs_callback_tcpport;
103         if (clp->cl_addr.ss_family == AF_INET6)
104                 port = nn->nfs_callback_tcpport6;
105 
106         status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
107         if (status != 0)
108                 goto out;
109         clp->cl_clientid = clid.clientid;
110         clp->cl_confirm = clid.confirm;
111         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
112 do_confirm:
113         status = nfs4_proc_setclientid_confirm(clp, &clid, cred);
114         if (status != 0)
115                 goto out;
116         clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
117         nfs4_schedule_state_renewal(clp);
118 out:
119         return status;
120 }
121 
122 /**
123  * nfs40_discover_server_trunking - Detect server IP address trunking (mv0)
124  *
125  * @clp: nfs_client under test
126  * @result: OUT: found nfs_client, or clp
127  * @cred: credential to use for trunking test
128  *
129  * Returns zero, a negative errno, or a negative NFS4ERR status.
130  * If zero is returned, an nfs_client pointer is planted in
131  * "result".
132  *
133  * Note: The returned client may not yet be marked ready.
134  */
135 int nfs40_discover_server_trunking(struct nfs_client *clp,
136                                    struct nfs_client **result,
137                                    struct rpc_cred *cred)
138 {
139         struct nfs4_setclientid_res clid = {
140                 .clientid = clp->cl_clientid,
141                 .confirm = clp->cl_confirm,
142         };
143         struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
144         unsigned short port;
145         int status;
146 
147         port = nn->nfs_callback_tcpport;
148         if (clp->cl_addr.ss_family == AF_INET6)
149                 port = nn->nfs_callback_tcpport6;
150 
151         status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
152         if (status != 0)
153                 goto out;
154         clp->cl_clientid = clid.clientid;
155         clp->cl_confirm = clid.confirm;
156 
157         status = nfs40_walk_client_list(clp, result, cred);
158         if (status == 0) {
159                 /* Sustain the lease, even if it's empty.  If the clientid4
160                  * goes stale it's of no use for trunking discovery. */
161                 nfs4_schedule_state_renewal(*result);
162         }
163 out:
164         return status;
165 }
166 
167 struct rpc_cred *nfs4_get_machine_cred_locked(struct nfs_client *clp)
168 {
169         struct rpc_cred *cred = NULL;
170 
171         if (clp->cl_machine_cred != NULL)
172                 cred = get_rpccred(clp->cl_machine_cred);
173         return cred;
174 }
175 
176 static void nfs4_root_machine_cred(struct nfs_client *clp)
177 {
178         struct rpc_cred *cred, *new;
179 
180         new = rpc_lookup_machine_cred(NULL);
181         spin_lock(&clp->cl_lock);
182         cred = clp->cl_machine_cred;
183         clp->cl_machine_cred = new;
184         spin_unlock(&clp->cl_lock);
185         if (cred != NULL)
186                 put_rpccred(cred);
187 }
188 
189 static struct rpc_cred *
190 nfs4_get_renew_cred_server_locked(struct nfs_server *server)
191 {
192         struct rpc_cred *cred = NULL;
193         struct nfs4_state_owner *sp;
194         struct rb_node *pos;
195 
196         for (pos = rb_first(&server->state_owners);
197              pos != NULL;
198              pos = rb_next(pos)) {
199                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
200                 if (list_empty(&sp->so_states))
201                         continue;
202                 cred = get_rpccred(sp->so_cred);
203                 break;
204         }
205         return cred;
206 }
207 
208 /**
209  * nfs4_get_renew_cred_locked - Acquire credential for a renew operation
210  * @clp: client state handle
211  *
212  * Returns an rpc_cred with reference count bumped, or NULL.
213  * Caller must hold clp->cl_lock.
214  */
215 struct rpc_cred *nfs4_get_renew_cred_locked(struct nfs_client *clp)
216 {
217         struct rpc_cred *cred = NULL;
218         struct nfs_server *server;
219 
220         /* Use machine credentials if available */
221         cred = nfs4_get_machine_cred_locked(clp);
222         if (cred != NULL)
223                 goto out;
224 
225         rcu_read_lock();
226         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
227                 cred = nfs4_get_renew_cred_server_locked(server);
228                 if (cred != NULL)
229                         break;
230         }
231         rcu_read_unlock();
232 
233 out:
234         return cred;
235 }
236 
237 static void nfs4_end_drain_slot_table(struct nfs4_slot_table *tbl)
238 {
239         if (test_and_clear_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state)) {
240                 spin_lock(&tbl->slot_tbl_lock);
241                 nfs41_wake_slot_table(tbl);
242                 spin_unlock(&tbl->slot_tbl_lock);
243         }
244 }
245 
246 static void nfs4_end_drain_session(struct nfs_client *clp)
247 {
248         struct nfs4_session *ses = clp->cl_session;
249 
250         if (clp->cl_slot_tbl) {
251                 nfs4_end_drain_slot_table(clp->cl_slot_tbl);
252                 return;
253         }
254 
255         if (ses != NULL) {
256                 nfs4_end_drain_slot_table(&ses->bc_slot_table);
257                 nfs4_end_drain_slot_table(&ses->fc_slot_table);
258         }
259 }
260 
261 static int nfs4_drain_slot_tbl(struct nfs4_slot_table *tbl)
262 {
263         set_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
264         spin_lock(&tbl->slot_tbl_lock);
265         if (tbl->highest_used_slotid != NFS4_NO_SLOT) {
266                 reinit_completion(&tbl->complete);
267                 spin_unlock(&tbl->slot_tbl_lock);
268                 return wait_for_completion_interruptible(&tbl->complete);
269         }
270         spin_unlock(&tbl->slot_tbl_lock);
271         return 0;
272 }
273 
274 static int nfs4_begin_drain_session(struct nfs_client *clp)
275 {
276         struct nfs4_session *ses = clp->cl_session;
277         int ret;
278 
279         if (clp->cl_slot_tbl)
280                 return nfs4_drain_slot_tbl(clp->cl_slot_tbl);
281 
282         /* back channel */
283         ret = nfs4_drain_slot_tbl(&ses->bc_slot_table);
284         if (ret)
285                 return ret;
286         /* fore channel */
287         return nfs4_drain_slot_tbl(&ses->fc_slot_table);
288 }
289 
290 #if defined(CONFIG_NFS_V4_1)
291 
292 static int nfs41_setup_state_renewal(struct nfs_client *clp)
293 {
294         int status;
295         struct nfs_fsinfo fsinfo;
296         unsigned long now;
297 
298         if (!test_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state)) {
299                 nfs4_schedule_state_renewal(clp);
300                 return 0;
301         }
302 
303         now = jiffies;
304         status = nfs4_proc_get_lease_time(clp, &fsinfo);
305         if (status == 0) {
306                 nfs4_set_lease_period(clp, fsinfo.lease_time * HZ, now);
307                 nfs4_schedule_state_renewal(clp);
308         }
309 
310         return status;
311 }
312 
313 static void nfs41_finish_session_reset(struct nfs_client *clp)
314 {
315         clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
316         clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
317         /* create_session negotiated new slot table */
318         clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
319         nfs41_setup_state_renewal(clp);
320 }
321 
322 int nfs41_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
323 {
324         int status;
325 
326         if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
327                 goto do_confirm;
328         status = nfs4_proc_exchange_id(clp, cred);
329         if (status != 0)
330                 goto out;
331         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
332 do_confirm:
333         status = nfs4_proc_create_session(clp, cred);
334         if (status != 0)
335                 goto out;
336         nfs41_finish_session_reset(clp);
337         nfs_mark_client_ready(clp, NFS_CS_READY);
338 out:
339         return status;
340 }
341 
342 /**
343  * nfs41_discover_server_trunking - Detect server IP address trunking (mv1)
344  *
345  * @clp: nfs_client under test
346  * @result: OUT: found nfs_client, or clp
347  * @cred: credential to use for trunking test
348  *
349  * Returns NFS4_OK, a negative errno, or a negative NFS4ERR status.
350  * If NFS4_OK is returned, an nfs_client pointer is planted in
351  * "result".
352  *
353  * Note: The returned client may not yet be marked ready.
354  */
355 int nfs41_discover_server_trunking(struct nfs_client *clp,
356                                    struct nfs_client **result,
357                                    struct rpc_cred *cred)
358 {
359         int status;
360 
361         status = nfs4_proc_exchange_id(clp, cred);
362         if (status != NFS4_OK)
363                 return status;
364 
365         status = nfs41_walk_client_list(clp, result, cred);
366         if (status < 0)
367                 return status;
368         if (clp != *result)
369                 return 0;
370 
371         /*
372          * Purge state if the client id was established in a prior
373          * instance and the client id could not have arrived on the
374          * server via Transparent State Migration.
375          */
376         if (clp->cl_exchange_flags & EXCHGID4_FLAG_CONFIRMED_R) {
377                 if (!test_bit(NFS_CS_TSM_POSSIBLE, &clp->cl_flags))
378                         set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
379                 else
380                         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
381         }
382         nfs4_schedule_state_manager(clp);
383         status = nfs_wait_client_init_complete(clp);
384         if (status < 0)
385                 nfs_put_client(clp);
386         return status;
387 }
388 
389 #endif /* CONFIG_NFS_V4_1 */
390 
391 /**
392  * nfs4_get_clid_cred - Acquire credential for a setclientid operation
393  * @clp: client state handle
394  *
395  * Returns an rpc_cred with reference count bumped, or NULL.
396  */
397 struct rpc_cred *nfs4_get_clid_cred(struct nfs_client *clp)
398 {
399         struct rpc_cred *cred;
400 
401         spin_lock(&clp->cl_lock);
402         cred = nfs4_get_machine_cred_locked(clp);
403         spin_unlock(&clp->cl_lock);
404         return cred;
405 }
406 
407 static struct nfs4_state_owner *
408 nfs4_find_state_owner_locked(struct nfs_server *server, struct rpc_cred *cred)
409 {
410         struct rb_node **p = &server->state_owners.rb_node,
411                        *parent = NULL;
412         struct nfs4_state_owner *sp;
413 
414         while (*p != NULL) {
415                 parent = *p;
416                 sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
417 
418                 if (cred < sp->so_cred)
419                         p = &parent->rb_left;
420                 else if (cred > sp->so_cred)
421                         p = &parent->rb_right;
422                 else {
423                         if (!list_empty(&sp->so_lru))
424                                 list_del_init(&sp->so_lru);
425                         atomic_inc(&sp->so_count);
426                         return sp;
427                 }
428         }
429         return NULL;
430 }
431 
432 static struct nfs4_state_owner *
433 nfs4_insert_state_owner_locked(struct nfs4_state_owner *new)
434 {
435         struct nfs_server *server = new->so_server;
436         struct rb_node **p = &server->state_owners.rb_node,
437                        *parent = NULL;
438         struct nfs4_state_owner *sp;
439 
440         while (*p != NULL) {
441                 parent = *p;
442                 sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
443 
444                 if (new->so_cred < sp->so_cred)
445                         p = &parent->rb_left;
446                 else if (new->so_cred > sp->so_cred)
447                         p = &parent->rb_right;
448                 else {
449                         if (!list_empty(&sp->so_lru))
450                                 list_del_init(&sp->so_lru);
451                         atomic_inc(&sp->so_count);
452                         return sp;
453                 }
454         }
455         rb_link_node(&new->so_server_node, parent, p);
456         rb_insert_color(&new->so_server_node, &server->state_owners);
457         return new;
458 }
459 
460 static void
461 nfs4_remove_state_owner_locked(struct nfs4_state_owner *sp)
462 {
463         struct nfs_server *server = sp->so_server;
464 
465         if (!RB_EMPTY_NODE(&sp->so_server_node))
466                 rb_erase(&sp->so_server_node, &server->state_owners);
467 }
468 
469 static void
470 nfs4_init_seqid_counter(struct nfs_seqid_counter *sc)
471 {
472         sc->create_time = ktime_get();
473         sc->flags = 0;
474         sc->counter = 0;
475         spin_lock_init(&sc->lock);
476         INIT_LIST_HEAD(&sc->list);
477         rpc_init_wait_queue(&sc->wait, "Seqid_waitqueue");
478 }
479 
480 static void
481 nfs4_destroy_seqid_counter(struct nfs_seqid_counter *sc)
482 {
483         rpc_destroy_wait_queue(&sc->wait);
484 }
485 
486 /*
487  * nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
488  * create a new state_owner.
489  *
490  */
491 static struct nfs4_state_owner *
492 nfs4_alloc_state_owner(struct nfs_server *server,
493                 struct rpc_cred *cred,
494                 gfp_t gfp_flags)
495 {
496         struct nfs4_state_owner *sp;
497 
498         sp = kzalloc(sizeof(*sp), gfp_flags);
499         if (!sp)
500                 return NULL;
501         sp->so_seqid.owner_id = ida_simple_get(&server->openowner_id, 0, 0,
502                                                 gfp_flags);
503         if (sp->so_seqid.owner_id < 0) {
504                 kfree(sp);
505                 return NULL;
506         }
507         sp->so_server = server;
508         sp->so_cred = get_rpccred(cred);
509         spin_lock_init(&sp->so_lock);
510         INIT_LIST_HEAD(&sp->so_states);
511         nfs4_init_seqid_counter(&sp->so_seqid);
512         atomic_set(&sp->so_count, 1);
513         INIT_LIST_HEAD(&sp->so_lru);
514         seqcount_init(&sp->so_reclaim_seqcount);
515         mutex_init(&sp->so_delegreturn_mutex);
516         return sp;
517 }
518 
519 static void
520 nfs4_reset_state_owner(struct nfs4_state_owner *sp)
521 {
522         /* This state_owner is no longer usable, but must
523          * remain in place so that state recovery can find it
524          * and the opens associated with it.
525          * It may also be used for new 'open' request to
526          * return a delegation to the server.
527          * So update the 'create_time' so that it looks like
528          * a new state_owner.  This will cause the server to
529          * request an OPEN_CONFIRM to start a new sequence.
530          */
531         sp->so_seqid.create_time = ktime_get();
532 }
533 
534 static void nfs4_free_state_owner(struct nfs4_state_owner *sp)
535 {
536         nfs4_destroy_seqid_counter(&sp->so_seqid);
537         put_rpccred(sp->so_cred);
538         ida_simple_remove(&sp->so_server->openowner_id, sp->so_seqid.owner_id);
539         kfree(sp);
540 }
541 
542 static void nfs4_gc_state_owners(struct nfs_server *server)
543 {
544         struct nfs_client *clp = server->nfs_client;
545         struct nfs4_state_owner *sp, *tmp;
546         unsigned long time_min, time_max;
547         LIST_HEAD(doomed);
548 
549         spin_lock(&clp->cl_lock);
550         time_max = jiffies;
551         time_min = (long)time_max - (long)clp->cl_lease_time;
552         list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
553                 /* NB: LRU is sorted so that oldest is at the head */
554                 if (time_in_range(sp->so_expires, time_min, time_max))
555                         break;
556                 list_move(&sp->so_lru, &doomed);
557                 nfs4_remove_state_owner_locked(sp);
558         }
559         spin_unlock(&clp->cl_lock);
560 
561         list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
562                 list_del(&sp->so_lru);
563                 nfs4_free_state_owner(sp);
564         }
565 }
566 
567 /**
568  * nfs4_get_state_owner - Look up a state owner given a credential
569  * @server: nfs_server to search
570  * @cred: RPC credential to match
571  *
572  * Returns a pointer to an instantiated nfs4_state_owner struct, or NULL.
573  */
574 struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server,
575                                               struct rpc_cred *cred,
576                                               gfp_t gfp_flags)
577 {
578         struct nfs_client *clp = server->nfs_client;
579         struct nfs4_state_owner *sp, *new;
580 
581         spin_lock(&clp->cl_lock);
582         sp = nfs4_find_state_owner_locked(server, cred);
583         spin_unlock(&clp->cl_lock);
584         if (sp != NULL)
585                 goto out;
586         new = nfs4_alloc_state_owner(server, cred, gfp_flags);
587         if (new == NULL)
588                 goto out;
589         spin_lock(&clp->cl_lock);
590         sp = nfs4_insert_state_owner_locked(new);
591         spin_unlock(&clp->cl_lock);
592         if (sp != new)
593                 nfs4_free_state_owner(new);
594 out:
595         nfs4_gc_state_owners(server);
596         return sp;
597 }
598 
599 /**
600  * nfs4_put_state_owner - Release a nfs4_state_owner
601  * @sp: state owner data to release
602  *
603  * Note that we keep released state owners on an LRU
604  * list.
605  * This caches valid state owners so that they can be
606  * reused, to avoid the OPEN_CONFIRM on minor version 0.
607  * It also pins the uniquifier of dropped state owners for
608  * a while, to ensure that those state owner names are
609  * never reused.
610  */
611 void nfs4_put_state_owner(struct nfs4_state_owner *sp)
612 {
613         struct nfs_server *server = sp->so_server;
614         struct nfs_client *clp = server->nfs_client;
615 
616         if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
617                 return;
618 
619         sp->so_expires = jiffies;
620         list_add_tail(&sp->so_lru, &server->state_owners_lru);
621         spin_unlock(&clp->cl_lock);
622 }
623 
624 /**
625  * nfs4_purge_state_owners - Release all cached state owners
626  * @server: nfs_server with cached state owners to release
627  *
628  * Called at umount time.  Remaining state owners will be on
629  * the LRU with ref count of zero.
630  */
631 void nfs4_purge_state_owners(struct nfs_server *server)
632 {
633         struct nfs_client *clp = server->nfs_client;
634         struct nfs4_state_owner *sp, *tmp;
635         LIST_HEAD(doomed);
636 
637         spin_lock(&clp->cl_lock);
638         list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
639                 list_move(&sp->so_lru, &doomed);
640                 nfs4_remove_state_owner_locked(sp);
641         }
642         spin_unlock(&clp->cl_lock);
643 
644         list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
645                 list_del(&sp->so_lru);
646                 nfs4_free_state_owner(sp);
647         }
648 }
649 
650 static struct nfs4_state *
651 nfs4_alloc_open_state(void)
652 {
653         struct nfs4_state *state;
654 
655         state = kzalloc(sizeof(*state), GFP_NOFS);
656         if (!state)
657                 return NULL;
658         refcount_set(&state->count, 1);
659         INIT_LIST_HEAD(&state->lock_states);
660         spin_lock_init(&state->state_lock);
661         seqlock_init(&state->seqlock);
662         init_waitqueue_head(&state->waitq);
663         return state;
664 }
665 
666 void
667 nfs4_state_set_mode_locked(struct nfs4_state *state, fmode_t fmode)
668 {
669         if (state->state == fmode)
670                 return;
671         /* NB! List reordering - see the reclaim code for why.  */
672         if ((fmode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
673                 if (fmode & FMODE_WRITE)
674                         list_move(&state->open_states, &state->owner->so_states);
675                 else
676                         list_move_tail(&state->open_states, &state->owner->so_states);
677         }
678         state->state = fmode;
679 }
680 
681 static struct nfs4_state *
682 __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
683 {
684         struct nfs_inode *nfsi = NFS_I(inode);
685         struct nfs4_state *state;
686 
687         list_for_each_entry_rcu(state, &nfsi->open_states, inode_states) {
688                 if (state->owner != owner)
689                         continue;
690                 if (!nfs4_valid_open_stateid(state))
691                         continue;
692                 if (refcount_inc_not_zero(&state->count))
693                         return state;
694         }
695         return NULL;
696 }
697 
698 static void
699 nfs4_free_open_state(struct nfs4_state *state)
700 {
701         kfree_rcu(state, rcu_head);
702 }
703 
704 struct nfs4_state *
705 nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
706 {
707         struct nfs4_state *state, *new;
708         struct nfs_inode *nfsi = NFS_I(inode);
709 
710         rcu_read_lock();
711         state = __nfs4_find_state_byowner(inode, owner);
712         rcu_read_unlock();
713         if (state)
714                 goto out;
715         new = nfs4_alloc_open_state();
716         spin_lock(&owner->so_lock);
717         spin_lock(&inode->i_lock);
718         state = __nfs4_find_state_byowner(inode, owner);
719         if (state == NULL && new != NULL) {
720                 state = new;
721                 state->owner = owner;
722                 atomic_inc(&owner->so_count);
723                 list_add_rcu(&state->inode_states, &nfsi->open_states);
724                 ihold(inode);
725                 state->inode = inode;
726                 spin_unlock(&inode->i_lock);
727                 /* Note: The reclaim code dictates that we add stateless
728                  * and read-only stateids to the end of the list */
729                 list_add_tail(&state->open_states, &owner->so_states);
730                 spin_unlock(&owner->so_lock);
731         } else {
732                 spin_unlock(&inode->i_lock);
733                 spin_unlock(&owner->so_lock);
734                 if (new)
735                         nfs4_free_open_state(new);
736         }
737 out:
738         return state;
739 }
740 
741 void nfs4_put_open_state(struct nfs4_state *state)
742 {
743         struct inode *inode = state->inode;
744         struct nfs4_state_owner *owner = state->owner;
745 
746         if (!refcount_dec_and_lock(&state->count, &owner->so_lock))
747                 return;
748         spin_lock(&inode->i_lock);
749         list_del_rcu(&state->inode_states);
750         list_del(&state->open_states);
751         spin_unlock(&inode->i_lock);
752         spin_unlock(&owner->so_lock);
753         iput(inode);
754         nfs4_free_open_state(state);
755         nfs4_put_state_owner(owner);
756 }
757 
758 /*
759  * Close the current file.
760  */
761 static void __nfs4_close(struct nfs4_state *state,
762                 fmode_t fmode, gfp_t gfp_mask, int wait)
763 {
764         struct nfs4_state_owner *owner = state->owner;
765         int call_close = 0;
766         fmode_t newstate;
767 
768         atomic_inc(&owner->so_count);
769         /* Protect against nfs4_find_state() */
770         spin_lock(&owner->so_lock);
771         switch (fmode & (FMODE_READ | FMODE_WRITE)) {
772                 case FMODE_READ:
773                         state->n_rdonly--;
774                         break;
775                 case FMODE_WRITE:
776                         state->n_wronly--;
777                         break;
778                 case FMODE_READ|FMODE_WRITE:
779                         state->n_rdwr--;
780         }
781         newstate = FMODE_READ|FMODE_WRITE;
782         if (state->n_rdwr == 0) {
783                 if (state->n_rdonly == 0) {
784                         newstate &= ~FMODE_READ;
785                         call_close |= test_bit(NFS_O_RDONLY_STATE, &state->flags);
786                         call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
787                 }
788                 if (state->n_wronly == 0) {
789                         newstate &= ~FMODE_WRITE;
790                         call_close |= test_bit(NFS_O_WRONLY_STATE, &state->flags);
791                         call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
792                 }
793                 if (newstate == 0)
794                         clear_bit(NFS_DELEGATED_STATE, &state->flags);
795         }
796         nfs4_state_set_mode_locked(state, newstate);
797         spin_unlock(&owner->so_lock);
798 
799         if (!call_close) {
800                 nfs4_put_open_state(state);
801                 nfs4_put_state_owner(owner);
802         } else
803                 nfs4_do_close(state, gfp_mask, wait);
804 }
805 
806 void nfs4_close_state(struct nfs4_state *state, fmode_t fmode)
807 {
808         __nfs4_close(state, fmode, GFP_NOFS, 0);
809 }
810 
811 void nfs4_close_sync(struct nfs4_state *state, fmode_t fmode)
812 {
813         __nfs4_close(state, fmode, GFP_KERNEL, 1);
814 }
815 
816 /*
817  * Search the state->lock_states for an existing lock_owner
818  * that is compatible with either of the given owners.
819  * If the second is non-zero, then the first refers to a Posix-lock
820  * owner (current->files) and the second refers to a flock/OFD
821  * owner (struct file*).  In that case, prefer a match for the first
822  * owner.
823  * If both sorts of locks are held on the one file we cannot know
824  * which stateid was intended to be used, so a "correct" choice cannot
825  * be made.  Failing that, a "consistent" choice is preferable.  The
826  * consistent choice we make is to prefer the first owner, that of a
827  * Posix lock.
828  */
829 static struct nfs4_lock_state *
830 __nfs4_find_lock_state(struct nfs4_state *state,
831                        fl_owner_t fl_owner, fl_owner_t fl_owner2)
832 {
833         struct nfs4_lock_state *pos, *ret = NULL;
834         list_for_each_entry(pos, &state->lock_states, ls_locks) {
835                 if (pos->ls_owner == fl_owner) {
836                         ret = pos;
837                         break;
838                 }
839                 if (pos->ls_owner == fl_owner2)
840                         ret = pos;
841         }
842         if (ret)
843                 refcount_inc(&ret->ls_count);
844         return ret;
845 }
846 
847 /*
848  * Return a compatible lock_state. If no initialized lock_state structure
849  * exists, return an uninitialized one.
850  *
851  */
852 static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
853 {
854         struct nfs4_lock_state *lsp;
855         struct nfs_server *server = state->owner->so_server;
856 
857         lsp = kzalloc(sizeof(*lsp), GFP_NOFS);
858         if (lsp == NULL)
859                 return NULL;
860         nfs4_init_seqid_counter(&lsp->ls_seqid);
861         refcount_set(&lsp->ls_count, 1);
862         lsp->ls_state = state;
863         lsp->ls_owner = fl_owner;
864         lsp->ls_seqid.owner_id = ida_simple_get(&server->lockowner_id, 0, 0, GFP_NOFS);
865         if (lsp->ls_seqid.owner_id < 0)
866                 goto out_free;
867         INIT_LIST_HEAD(&lsp->ls_locks);
868         return lsp;
869 out_free:
870         kfree(lsp);
871         return NULL;
872 }
873 
874 void nfs4_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp)
875 {
876         ida_simple_remove(&server->lockowner_id, lsp->ls_seqid.owner_id);
877         nfs4_destroy_seqid_counter(&lsp->ls_seqid);
878         kfree(lsp);
879 }
880 
881 /*
882  * Return a compatible lock_state. If no initialized lock_state structure
883  * exists, return an uninitialized one.
884  *
885  */
886 static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
887 {
888         struct nfs4_lock_state *lsp, *new = NULL;
889         
890         for(;;) {
891                 spin_lock(&state->state_lock);
892                 lsp = __nfs4_find_lock_state(state, owner, NULL);
893                 if (lsp != NULL)
894                         break;
895                 if (new != NULL) {
896                         list_add(&new->ls_locks, &state->lock_states);
897                         set_bit(LK_STATE_IN_USE, &state->flags);
898                         lsp = new;
899                         new = NULL;
900                         break;
901                 }
902                 spin_unlock(&state->state_lock);
903                 new = nfs4_alloc_lock_state(state, owner);
904                 if (new == NULL)
905                         return NULL;
906         }
907         spin_unlock(&state->state_lock);
908         if (new != NULL)
909                 nfs4_free_lock_state(state->owner->so_server, new);
910         return lsp;
911 }
912 
913 /*
914  * Release reference to lock_state, and free it if we see that
915  * it is no longer in use
916  */
917 void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
918 {
919         struct nfs_server *server;
920         struct nfs4_state *state;
921 
922         if (lsp == NULL)
923                 return;
924         state = lsp->ls_state;
925         if (!refcount_dec_and_lock(&lsp->ls_count, &state->state_lock))
926                 return;
927         list_del(&lsp->ls_locks);
928         if (list_empty(&state->lock_states))
929                 clear_bit(LK_STATE_IN_USE, &state->flags);
930         spin_unlock(&state->state_lock);
931         server = state->owner->so_server;
932         if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags)) {
933                 struct nfs_client *clp = server->nfs_client;
934 
935                 clp->cl_mvops->free_lock_state(server, lsp);
936         } else
937                 nfs4_free_lock_state(server, lsp);
938 }
939 
940 static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
941 {
942         struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
943 
944         dst->fl_u.nfs4_fl.owner = lsp;
945         refcount_inc(&lsp->ls_count);
946 }
947 
948 static void nfs4_fl_release_lock(struct file_lock *fl)
949 {
950         nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
951 }
952 
953 static const struct file_lock_operations nfs4_fl_lock_ops = {
954         .fl_copy_lock = nfs4_fl_copy_lock,
955         .fl_release_private = nfs4_fl_release_lock,
956 };
957 
958 int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
959 {
960         struct nfs4_lock_state *lsp;
961 
962         if (fl->fl_ops != NULL)
963                 return 0;
964         lsp = nfs4_get_lock_state(state, fl->fl_owner);
965         if (lsp == NULL)
966                 return -ENOMEM;
967         fl->fl_u.nfs4_fl.owner = lsp;
968         fl->fl_ops = &nfs4_fl_lock_ops;
969         return 0;
970 }
971 
972 static int nfs4_copy_lock_stateid(nfs4_stateid *dst,
973                 struct nfs4_state *state,
974                 const struct nfs_lock_context *l_ctx)
975 {
976         struct nfs4_lock_state *lsp;
977         fl_owner_t fl_owner, fl_flock_owner;
978         int ret = -ENOENT;
979 
980         if (l_ctx == NULL)
981                 goto out;
982 
983         if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
984                 goto out;
985 
986         fl_owner = l_ctx->lockowner;
987         fl_flock_owner = l_ctx->open_context->flock_owner;
988 
989         spin_lock(&state->state_lock);
990         lsp = __nfs4_find_lock_state(state, fl_owner, fl_flock_owner);
991         if (lsp && test_bit(NFS_LOCK_LOST, &lsp->ls_flags))
992                 ret = -EIO;
993         else if (lsp != NULL && test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags) != 0) {
994                 nfs4_stateid_copy(dst, &lsp->ls_stateid);
995                 ret = 0;
996         }
997         spin_unlock(&state->state_lock);
998         nfs4_put_lock_state(lsp);
999 out:
1000         return ret;
1001 }
1002 
1003 bool nfs4_refresh_open_stateid(nfs4_stateid *dst, struct nfs4_state *state)
1004 {
1005         bool ret;
1006         int seq;
1007 
1008         do {
1009                 ret = false;
1010                 seq = read_seqbegin(&state->seqlock);
1011                 if (nfs4_state_match_open_stateid_other(state, dst)) {
1012                         dst->seqid = state->open_stateid.seqid;
1013                         ret = true;
1014                 }
1015         } while (read_seqretry(&state->seqlock, seq));
1016         return ret;
1017 }
1018 
1019 bool nfs4_copy_open_stateid(nfs4_stateid *dst, struct nfs4_state *state)
1020 {
1021         bool ret;
1022         const nfs4_stateid *src;
1023         int seq;
1024 
1025         do {
1026                 ret = false;
1027                 src = &zero_stateid;
1028                 seq = read_seqbegin(&state->seqlock);
1029                 if (test_bit(NFS_OPEN_STATE, &state->flags)) {
1030                         src = &state->open_stateid;
1031                         ret = true;
1032                 }
1033                 nfs4_stateid_copy(dst, src);
1034         } while (read_seqretry(&state->seqlock, seq));
1035         return ret;
1036 }
1037 
1038 /*
1039  * Byte-range lock aware utility to initialize the stateid of read/write
1040  * requests.
1041  */
1042 int nfs4_select_rw_stateid(struct nfs4_state *state,
1043                 fmode_t fmode, const struct nfs_lock_context *l_ctx,
1044                 nfs4_stateid *dst, struct rpc_cred **cred)
1045 {
1046         int ret;
1047 
1048         if (!nfs4_valid_open_stateid(state))
1049                 return -EIO;
1050         if (cred != NULL)
1051                 *cred = NULL;
1052         ret = nfs4_copy_lock_stateid(dst, state, l_ctx);
1053         if (ret == -EIO)
1054                 /* A lost lock - don't even consider delegations */
1055                 goto out;
1056         /* returns true if delegation stateid found and copied */
1057         if (nfs4_copy_delegation_stateid(state->inode, fmode, dst, cred)) {
1058                 ret = 0;
1059                 goto out;
1060         }
1061         if (ret != -ENOENT)
1062                 /* nfs4_copy_delegation_stateid() didn't over-write
1063                  * dst, so it still has the lock stateid which we now
1064                  * choose to use.
1065                  */
1066                 goto out;
1067         nfs4_copy_open_stateid(dst, state);
1068         ret = 0;
1069 out:
1070         if (nfs_server_capable(state->inode, NFS_CAP_STATEID_NFSV41))
1071                 dst->seqid = 0;
1072         return ret;
1073 }
1074 
1075 struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask)
1076 {
1077         struct nfs_seqid *new;
1078 
1079         new = kmalloc(sizeof(*new), gfp_mask);
1080         if (new == NULL)
1081                 return ERR_PTR(-ENOMEM);
1082         new->sequence = counter;
1083         INIT_LIST_HEAD(&new->list);
1084         new->task = NULL;
1085         return new;
1086 }
1087 
1088 void nfs_release_seqid(struct nfs_seqid *seqid)
1089 {
1090         struct nfs_seqid_counter *sequence;
1091 
1092         if (seqid == NULL || list_empty(&seqid->list))
1093                 return;
1094         sequence = seqid->sequence;
1095         spin_lock(&sequence->lock);
1096         list_del_init(&seqid->list);
1097         if (!list_empty(&sequence->list)) {
1098                 struct nfs_seqid *next;
1099 
1100                 next = list_first_entry(&sequence->list,
1101                                 struct nfs_seqid, list);
1102                 rpc_wake_up_queued_task(&sequence->wait, next->task);
1103         }
1104         spin_unlock(&sequence->lock);
1105 }
1106 
1107 void nfs_free_seqid(struct nfs_seqid *seqid)
1108 {
1109         nfs_release_seqid(seqid);
1110         kfree(seqid);
1111 }
1112 
1113 /*
1114  * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
1115  * failed with a seqid incrementing error -
1116  * see comments nfs4.h:seqid_mutating_error()
1117  */
1118 static void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
1119 {
1120         switch (status) {
1121                 case 0:
1122                         break;
1123                 case -NFS4ERR_BAD_SEQID:
1124                         if (seqid->sequence->flags & NFS_SEQID_CONFIRMED)
1125                                 return;
1126                         pr_warn_ratelimited("NFS: v4 server returned a bad"
1127                                         " sequence-id error on an"
1128                                         " unconfirmed sequence %p!\n",
1129                                         seqid->sequence);
1130                 case -NFS4ERR_STALE_CLIENTID:
1131                 case -NFS4ERR_STALE_STATEID:
1132                 case -NFS4ERR_BAD_STATEID:
1133                 case -NFS4ERR_BADXDR:
1134                 case -NFS4ERR_RESOURCE:
1135                 case -NFS4ERR_NOFILEHANDLE:
1136                 case -NFS4ERR_MOVED:
1137                         /* Non-seqid mutating errors */
1138                         return;
1139         };
1140         /*
1141          * Note: no locking needed as we are guaranteed to be first
1142          * on the sequence list
1143          */
1144         seqid->sequence->counter++;
1145 }
1146 
1147 void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
1148 {
1149         struct nfs4_state_owner *sp;
1150 
1151         if (seqid == NULL)
1152                 return;
1153 
1154         sp = container_of(seqid->sequence, struct nfs4_state_owner, so_seqid);
1155         if (status == -NFS4ERR_BAD_SEQID)
1156                 nfs4_reset_state_owner(sp);
1157         if (!nfs4_has_session(sp->so_server->nfs_client))
1158                 nfs_increment_seqid(status, seqid);
1159 }
1160 
1161 /*
1162  * Increment the seqid if the LOCK/LOCKU succeeded, or
1163  * failed with a seqid incrementing error -
1164  * see comments nfs4.h:seqid_mutating_error()
1165  */
1166 void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
1167 {
1168         if (seqid != NULL)
1169                 nfs_increment_seqid(status, seqid);
1170 }
1171 
1172 int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
1173 {
1174         struct nfs_seqid_counter *sequence;
1175         int status = 0;
1176 
1177         if (seqid == NULL)
1178                 goto out;
1179         sequence = seqid->sequence;
1180         spin_lock(&sequence->lock);
1181         seqid->task = task;
1182         if (list_empty(&seqid->list))
1183                 list_add_tail(&seqid->list, &sequence->list);
1184         if (list_first_entry(&sequence->list, struct nfs_seqid, list) == seqid)
1185                 goto unlock;
1186         rpc_sleep_on(&sequence->wait, task, NULL);
1187         status = -EAGAIN;
1188 unlock:
1189         spin_unlock(&sequence->lock);
1190 out:
1191         return status;
1192 }
1193 
1194 static int nfs4_run_state_manager(void *);
1195 
1196 static void nfs4_clear_state_manager_bit(struct nfs_client *clp)
1197 {
1198         smp_mb__before_atomic();
1199         clear_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state);
1200         smp_mb__after_atomic();
1201         wake_up_bit(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING);
1202         rpc_wake_up(&clp->cl_rpcwaitq);
1203 }
1204 
1205 /*
1206  * Schedule the nfs_client asynchronous state management routine
1207  */
1208 void nfs4_schedule_state_manager(struct nfs_client *clp)
1209 {
1210         struct task_struct *task;
1211         char buf[INET6_ADDRSTRLEN + sizeof("-manager") + 1];
1212 
1213         set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
1214         if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
1215                 return;
1216         __module_get(THIS_MODULE);
1217         refcount_inc(&clp->cl_count);
1218 
1219         /* The rcu_read_lock() is not strictly necessary, as the state
1220          * manager is the only thread that ever changes the rpc_xprt
1221          * after it's initialized.  At this point, we're single threaded. */
1222         rcu_read_lock();
1223         snprintf(buf, sizeof(buf), "%s-manager",
1224                         rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
1225         rcu_read_unlock();
1226         task = kthread_run(nfs4_run_state_manager, clp, "%s", buf);
1227         if (IS_ERR(task)) {
1228                 printk(KERN_ERR "%s: kthread_run: %ld\n",
1229                         __func__, PTR_ERR(task));
1230                 nfs4_clear_state_manager_bit(clp);
1231                 nfs_put_client(clp);
1232                 module_put(THIS_MODULE);
1233         }
1234 }
1235 
1236 /*
1237  * Schedule a lease recovery attempt
1238  */
1239 void nfs4_schedule_lease_recovery(struct nfs_client *clp)
1240 {
1241         if (!clp)
1242                 return;
1243         if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1244                 set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1245         dprintk("%s: scheduling lease recovery for server %s\n", __func__,
1246                         clp->cl_hostname);
1247         nfs4_schedule_state_manager(clp);
1248 }
1249 EXPORT_SYMBOL_GPL(nfs4_schedule_lease_recovery);
1250 
1251 /**
1252  * nfs4_schedule_migration_recovery - trigger migration recovery
1253  *
1254  * @server: FSID that is migrating
1255  *
1256  * Returns zero if recovery has started, otherwise a negative NFS4ERR
1257  * value is returned.
1258  */
1259 int nfs4_schedule_migration_recovery(const struct nfs_server *server)
1260 {
1261         struct nfs_client *clp = server->nfs_client;
1262 
1263         if (server->fh_expire_type != NFS4_FH_PERSISTENT) {
1264                 pr_err("NFS: volatile file handles not supported (server %s)\n",
1265                                 clp->cl_hostname);
1266                 return -NFS4ERR_IO;
1267         }
1268 
1269         if (test_bit(NFS_MIG_FAILED, &server->mig_status))
1270                 return -NFS4ERR_IO;
1271 
1272         dprintk("%s: scheduling migration recovery for (%llx:%llx) on %s\n",
1273                         __func__,
1274                         (unsigned long long)server->fsid.major,
1275                         (unsigned long long)server->fsid.minor,
1276                         clp->cl_hostname);
1277 
1278         set_bit(NFS_MIG_IN_TRANSITION,
1279                         &((struct nfs_server *)server)->mig_status);
1280         set_bit(NFS4CLNT_MOVED, &clp->cl_state);
1281 
1282         nfs4_schedule_state_manager(clp);
1283         return 0;
1284 }
1285 EXPORT_SYMBOL_GPL(nfs4_schedule_migration_recovery);
1286 
1287 /**
1288  * nfs4_schedule_lease_moved_recovery - start lease-moved recovery
1289  *
1290  * @clp: server to check for moved leases
1291  *
1292  */
1293 void nfs4_schedule_lease_moved_recovery(struct nfs_client *clp)
1294 {
1295         dprintk("%s: scheduling lease-moved recovery for client ID %llx on %s\n",
1296                 __func__, clp->cl_clientid, clp->cl_hostname);
1297 
1298         set_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state);
1299         nfs4_schedule_state_manager(clp);
1300 }
1301 EXPORT_SYMBOL_GPL(nfs4_schedule_lease_moved_recovery);
1302 
1303 int nfs4_wait_clnt_recover(struct nfs_client *clp)
1304 {
1305         int res;
1306 
1307         might_sleep();
1308 
1309         refcount_inc(&clp->cl_count);
1310         res = wait_on_bit_action(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING,
1311                                  nfs_wait_bit_killable, TASK_KILLABLE);
1312         if (res)
1313                 goto out;
1314         if (clp->cl_cons_state < 0)
1315                 res = clp->cl_cons_state;
1316 out:
1317         nfs_put_client(clp);
1318         return res;
1319 }
1320 
1321 int nfs4_client_recover_expired_lease(struct nfs_client *clp)
1322 {
1323         unsigned int loop;
1324         int ret;
1325 
1326         for (loop = NFS4_MAX_LOOP_ON_RECOVER; loop != 0; loop--) {
1327                 ret = nfs4_wait_clnt_recover(clp);
1328                 if (ret != 0)
1329                         break;
1330                 if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) &&
1331                     !test_bit(NFS4CLNT_CHECK_LEASE,&clp->cl_state))
1332                         break;
1333                 nfs4_schedule_state_manager(clp);
1334                 ret = -EIO;
1335         }
1336         return ret;
1337 }
1338 
1339 /*
1340  * nfs40_handle_cb_pathdown - return all delegations after NFS4ERR_CB_PATH_DOWN
1341  * @clp: client to process
1342  *
1343  * Set the NFS4CLNT_LEASE_EXPIRED state in order to force a
1344  * resend of the SETCLIENTID and hence re-establish the
1345  * callback channel. Then return all existing delegations.
1346  */
1347 static void nfs40_handle_cb_pathdown(struct nfs_client *clp)
1348 {
1349         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1350         nfs_expire_all_delegations(clp);
1351         dprintk("%s: handling CB_PATHDOWN recovery for server %s\n", __func__,
1352                         clp->cl_hostname);
1353 }
1354 
1355 void nfs4_schedule_path_down_recovery(struct nfs_client *clp)
1356 {
1357         nfs40_handle_cb_pathdown(clp);
1358         nfs4_schedule_state_manager(clp);
1359 }
1360 
1361 static int nfs4_state_mark_reclaim_reboot(struct nfs_client *clp, struct nfs4_state *state)
1362 {
1363 
1364         if (!nfs4_valid_open_stateid(state))
1365                 return 0;
1366         set_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1367         /* Don't recover state that expired before the reboot */
1368         if (test_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags)) {
1369                 clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1370                 return 0;
1371         }
1372         set_bit(NFS_OWNER_RECLAIM_REBOOT, &state->owner->so_flags);
1373         set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1374         return 1;
1375 }
1376 
1377 int nfs4_state_mark_reclaim_nograce(struct nfs_client *clp, struct nfs4_state *state)
1378 {
1379         if (!nfs4_valid_open_stateid(state))
1380                 return 0;
1381         set_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
1382         clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1383         set_bit(NFS_OWNER_RECLAIM_NOGRACE, &state->owner->so_flags);
1384         set_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
1385         return 1;
1386 }
1387 
1388 int nfs4_schedule_stateid_recovery(const struct nfs_server *server, struct nfs4_state *state)
1389 {
1390         struct nfs_client *clp = server->nfs_client;
1391 
1392         if (!nfs4_state_mark_reclaim_nograce(clp, state))
1393                 return -EBADF;
1394         nfs_inode_find_delegation_state_and_recover(state->inode,
1395                         &state->stateid);
1396         dprintk("%s: scheduling stateid recovery for server %s\n", __func__,
1397                         clp->cl_hostname);
1398         nfs4_schedule_state_manager(clp);
1399         return 0;
1400 }
1401 EXPORT_SYMBOL_GPL(nfs4_schedule_stateid_recovery);
1402 
1403 static struct nfs4_lock_state *
1404 nfs_state_find_lock_state_by_stateid(struct nfs4_state *state,
1405                 const nfs4_stateid *stateid)
1406 {
1407         struct nfs4_lock_state *pos;
1408 
1409         list_for_each_entry(pos, &state->lock_states, ls_locks) {
1410                 if (!test_bit(NFS_LOCK_INITIALIZED, &pos->ls_flags))
1411                         continue;
1412                 if (nfs4_stateid_match_other(&pos->ls_stateid, stateid))
1413                         return pos;
1414         }
1415         return NULL;
1416 }
1417 
1418 static bool nfs_state_lock_state_matches_stateid(struct nfs4_state *state,
1419                 const nfs4_stateid *stateid)
1420 {
1421         bool found = false;
1422 
1423         if (test_bit(LK_STATE_IN_USE, &state->flags)) {
1424                 spin_lock(&state->state_lock);
1425                 if (nfs_state_find_lock_state_by_stateid(state, stateid))
1426                         found = true;
1427                 spin_unlock(&state->state_lock);
1428         }
1429         return found;
1430 }
1431 
1432 void nfs_inode_find_state_and_recover(struct inode *inode,
1433                 const nfs4_stateid *stateid)
1434 {
1435         struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
1436         struct nfs_inode *nfsi = NFS_I(inode);
1437         struct nfs_open_context *ctx;
1438         struct nfs4_state *state;
1439         bool found = false;
1440 
1441         rcu_read_lock();
1442         list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
1443                 state = ctx->state;
1444                 if (state == NULL)
1445                         continue;
1446                 if (nfs4_stateid_match_other(&state->stateid, stateid) &&
1447                     nfs4_state_mark_reclaim_nograce(clp, state)) {
1448                         found = true;
1449                         continue;
1450                 }
1451                 if (nfs4_stateid_match_other(&state->open_stateid, stateid) &&
1452                     nfs4_state_mark_reclaim_nograce(clp, state)) {
1453                         found = true;
1454                         continue;
1455                 }
1456                 if (nfs_state_lock_state_matches_stateid(state, stateid) &&
1457                     nfs4_state_mark_reclaim_nograce(clp, state))
1458                         found = true;
1459         }
1460         rcu_read_unlock();
1461 
1462         nfs_inode_find_delegation_state_and_recover(inode, stateid);
1463         if (found)
1464                 nfs4_schedule_state_manager(clp);
1465 }
1466 
1467 static void nfs4_state_mark_open_context_bad(struct nfs4_state *state)
1468 {
1469         struct inode *inode = state->inode;
1470         struct nfs_inode *nfsi = NFS_I(inode);
1471         struct nfs_open_context *ctx;
1472 
1473         rcu_read_lock();
1474         list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
1475                 if (ctx->state != state)
1476                         continue;
1477                 set_bit(NFS_CONTEXT_BAD, &ctx->flags);
1478         }
1479         rcu_read_unlock();
1480 }
1481 
1482 static void nfs4_state_mark_recovery_failed(struct nfs4_state *state, int error)
1483 {
1484         set_bit(NFS_STATE_RECOVERY_FAILED, &state->flags);
1485         nfs4_state_mark_open_context_bad(state);
1486 }
1487 
1488 
1489 static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_recovery_ops *ops)
1490 {
1491         struct inode *inode = state->inode;
1492         struct nfs_inode *nfsi = NFS_I(inode);
1493         struct file_lock *fl;
1494         struct nfs4_lock_state *lsp;
1495         int status = 0;
1496         struct file_lock_context *flctx = inode->i_flctx;
1497         struct list_head *list;
1498 
1499         if (flctx == NULL)
1500                 return 0;
1501 
1502         list = &flctx->flc_posix;
1503 
1504         /* Guard against delegation returns and new lock/unlock calls */
1505         down_write(&nfsi->rwsem);
1506         spin_lock(&flctx->flc_lock);
1507 restart:
1508         list_for_each_entry(fl, list, fl_list) {
1509                 if (nfs_file_open_context(fl->fl_file)->state != state)
1510                         continue;
1511                 spin_unlock(&flctx->flc_lock);
1512                 status = ops->recover_lock(state, fl);
1513                 switch (status) {
1514                 case 0:
1515                         break;
1516                 case -ESTALE:
1517                 case -NFS4ERR_ADMIN_REVOKED:
1518                 case -NFS4ERR_STALE_STATEID:
1519                 case -NFS4ERR_BAD_STATEID:
1520                 case -NFS4ERR_EXPIRED:
1521                 case -NFS4ERR_NO_GRACE:
1522                 case -NFS4ERR_STALE_CLIENTID:
1523                 case -NFS4ERR_BADSESSION:
1524                 case -NFS4ERR_BADSLOT:
1525                 case -NFS4ERR_BAD_HIGH_SLOT:
1526                 case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1527                         goto out;
1528                 default:
1529                         pr_err("NFS: %s: unhandled error %d\n",
1530                                         __func__, status);
1531                         /* Fall through */
1532                 case -ENOMEM:
1533                 case -NFS4ERR_DENIED:
1534                 case -NFS4ERR_RECLAIM_BAD:
1535                 case -NFS4ERR_RECLAIM_CONFLICT:
1536                         lsp = fl->fl_u.nfs4_fl.owner;
1537                         if (lsp)
1538                                 set_bit(NFS_LOCK_LOST, &lsp->ls_flags);
1539                         status = 0;
1540                 }
1541                 spin_lock(&flctx->flc_lock);
1542         }
1543         if (list == &flctx->flc_posix) {
1544                 list = &flctx->flc_flock;
1545                 goto restart;
1546         }
1547         spin_unlock(&flctx->flc_lock);
1548 out:
1549         up_write(&nfsi->rwsem);
1550         return status;
1551 }
1552 
1553 #ifdef CONFIG_NFS_V4_2
1554 static void nfs42_complete_copies(struct nfs4_state_owner *sp, struct nfs4_state *state)
1555 {
1556         struct nfs4_copy_state *copy;
1557 
1558         if (!test_bit(NFS_CLNT_DST_SSC_COPY_STATE, &state->flags))
1559                 return;
1560 
1561         spin_lock(&sp->so_server->nfs_client->cl_lock);
1562         list_for_each_entry(copy, &sp->so_server->ss_copies, copies) {
1563                 if (nfs4_stateid_match_other(&state->stateid, &copy->parent_state->stateid))
1564                         continue;
1565                 copy->flags = 1;
1566                 complete(&copy->completion);
1567                 break;
1568         }
1569         spin_unlock(&sp->so_server->nfs_client->cl_lock);
1570 }
1571 #else /* !CONFIG_NFS_V4_2 */
1572 static inline void nfs42_complete_copies(struct nfs4_state_owner *sp,
1573                                          struct nfs4_state *state)
1574 {
1575 }
1576 #endif /* CONFIG_NFS_V4_2 */
1577 
1578 static int __nfs4_reclaim_open_state(struct nfs4_state_owner *sp, struct nfs4_state *state,
1579                                      const struct nfs4_state_recovery_ops *ops)
1580 {
1581         struct nfs4_lock_state *lock;
1582         int status;
1583 
1584         status = ops->recover_open(sp, state);
1585         if (status < 0)
1586                 return status;
1587 
1588         status = nfs4_reclaim_locks(state, ops);
1589         if (status < 0)
1590                 return status;
1591 
1592         if (!test_bit(NFS_DELEGATED_STATE, &state->flags)) {
1593                 spin_lock(&state->state_lock);
1594                 list_for_each_entry(lock, &state->lock_states, ls_locks) {
1595                         if (!test_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags))
1596                                 pr_warn_ratelimited("NFS: %s: Lock reclaim failed!\n", __func__);
1597                 }
1598                 spin_unlock(&state->state_lock);
1599         }
1600 
1601         nfs42_complete_copies(sp, state);
1602         clear_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
1603         return status;
1604 }
1605 
1606 static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp, const struct nfs4_state_recovery_ops *ops)
1607 {
1608         struct nfs4_state *state;
1609         int status = 0;
1610 
1611         /* Note: we rely on the sp->so_states list being ordered 
1612          * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
1613          * states first.
1614          * This is needed to ensure that the server won't give us any
1615          * read delegations that we have to return if, say, we are
1616          * recovering after a network partition or a reboot from a
1617          * server that doesn't support a grace period.
1618          */
1619         spin_lock(&sp->so_lock);
1620         raw_write_seqcount_begin(&sp->so_reclaim_seqcount);
1621 restart:
1622         list_for_each_entry(state, &sp->so_states, open_states) {
1623                 if (!test_and_clear_bit(ops->state_flag_bit, &state->flags))
1624                         continue;
1625                 if (!nfs4_valid_open_stateid(state))
1626                         continue;
1627                 if (state->state == 0)
1628                         continue;
1629                 refcount_inc(&state->count);
1630                 spin_unlock(&sp->so_lock);
1631                 status = __nfs4_reclaim_open_state(sp, state, ops);
1632 
1633                 switch (status) {
1634                 default:
1635                         if (status >= 0)
1636                                 break;
1637                         printk(KERN_ERR "NFS: %s: unhandled error %d\n", __func__, status);
1638                         /* Fall through */
1639                 case -ENOENT:
1640                 case -ENOMEM:
1641                 case -EACCES:
1642                 case -EROFS:
1643                 case -EIO:
1644                 case -ESTALE:
1645                         /* Open state on this file cannot be recovered */
1646                         nfs4_state_mark_recovery_failed(state, status);
1647                         break;
1648                 case -EAGAIN:
1649                         ssleep(1);
1650                         /* Fall through */
1651                 case -NFS4ERR_ADMIN_REVOKED:
1652                 case -NFS4ERR_STALE_STATEID:
1653                 case -NFS4ERR_OLD_STATEID:
1654                 case -NFS4ERR_BAD_STATEID:
1655                 case -NFS4ERR_RECLAIM_BAD:
1656                 case -NFS4ERR_RECLAIM_CONFLICT:
1657                         nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1658                         break;
1659                 case -NFS4ERR_EXPIRED:
1660                 case -NFS4ERR_NO_GRACE:
1661                         nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1662                 case -NFS4ERR_STALE_CLIENTID:
1663                 case -NFS4ERR_BADSESSION:
1664                 case -NFS4ERR_BADSLOT:
1665                 case -NFS4ERR_BAD_HIGH_SLOT:
1666                 case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1667                         goto out_err;
1668                 }
1669                 nfs4_put_open_state(state);
1670                 spin_lock(&sp->so_lock);
1671                 goto restart;
1672         }
1673         raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1674         spin_unlock(&sp->so_lock);
1675         return 0;
1676 out_err:
1677         nfs4_put_open_state(state);
1678         spin_lock(&sp->so_lock);
1679         raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1680         spin_unlock(&sp->so_lock);
1681         return status;
1682 }
1683 
1684 static void nfs4_clear_open_state(struct nfs4_state *state)
1685 {
1686         struct nfs4_lock_state *lock;
1687 
1688         clear_bit(NFS_DELEGATED_STATE, &state->flags);
1689         clear_bit(NFS_O_RDONLY_STATE, &state->flags);
1690         clear_bit(NFS_O_WRONLY_STATE, &state->flags);
1691         clear_bit(NFS_O_RDWR_STATE, &state->flags);
1692         spin_lock(&state->state_lock);
1693         list_for_each_entry(lock, &state->lock_states, ls_locks) {
1694                 lock->ls_seqid.flags = 0;
1695                 clear_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags);
1696         }
1697         spin_unlock(&state->state_lock);
1698 }
1699 
1700 static void nfs4_reset_seqids(struct nfs_server *server,
1701         int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1702 {
1703         struct nfs_client *clp = server->nfs_client;
1704         struct nfs4_state_owner *sp;
1705         struct rb_node *pos;
1706         struct nfs4_state *state;
1707 
1708         spin_lock(&clp->cl_lock);
1709         for (pos = rb_first(&server->state_owners);
1710              pos != NULL;
1711              pos = rb_next(pos)) {
1712                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1713                 sp->so_seqid.flags = 0;
1714                 spin_lock(&sp->so_lock);
1715                 list_for_each_entry(state, &sp->so_states, open_states) {
1716                         if (mark_reclaim(clp, state))
1717                                 nfs4_clear_open_state(state);
1718                 }
1719                 spin_unlock(&sp->so_lock);
1720         }
1721         spin_unlock(&clp->cl_lock);
1722 }
1723 
1724 static void nfs4_state_mark_reclaim_helper(struct nfs_client *clp,
1725         int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1726 {
1727         struct nfs_server *server;
1728 
1729         rcu_read_lock();
1730         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1731                 nfs4_reset_seqids(server, mark_reclaim);
1732         rcu_read_unlock();
1733 }
1734 
1735 static void nfs4_state_start_reclaim_reboot(struct nfs_client *clp)
1736 {
1737         /* Mark all delegations for reclaim */
1738         nfs_delegation_mark_reclaim(clp);
1739         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_reboot);
1740 }
1741 
1742 static int nfs4_reclaim_complete(struct nfs_client *clp,
1743                                  const struct nfs4_state_recovery_ops *ops,
1744                                  struct rpc_cred *cred)
1745 {
1746         /* Notify the server we're done reclaiming our state */
1747         if (ops->reclaim_complete)
1748                 return ops->reclaim_complete(clp, cred);
1749         return 0;
1750 }
1751 
1752 static void nfs4_clear_reclaim_server(struct nfs_server *server)
1753 {
1754         struct nfs_client *clp = server->nfs_client;
1755         struct nfs4_state_owner *sp;
1756         struct rb_node *pos;
1757         struct nfs4_state *state;
1758 
1759         spin_lock(&clp->cl_lock);
1760         for (pos = rb_first(&server->state_owners);
1761              pos != NULL;
1762              pos = rb_next(pos)) {
1763                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1764                 spin_lock(&sp->so_lock);
1765                 list_for_each_entry(state, &sp->so_states, open_states) {
1766                         if (!test_and_clear_bit(NFS_STATE_RECLAIM_REBOOT,
1767                                                 &state->flags))
1768                                 continue;
1769                         nfs4_state_mark_reclaim_nograce(clp, state);
1770                 }
1771                 spin_unlock(&sp->so_lock);
1772         }
1773         spin_unlock(&clp->cl_lock);
1774 }
1775 
1776 static int nfs4_state_clear_reclaim_reboot(struct nfs_client *clp)
1777 {
1778         struct nfs_server *server;
1779 
1780         if (!test_and_clear_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
1781                 return 0;
1782 
1783         rcu_read_lock();
1784         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1785                 nfs4_clear_reclaim_server(server);
1786         rcu_read_unlock();
1787 
1788         nfs_delegation_reap_unclaimed(clp);
1789         return 1;
1790 }
1791 
1792 static void nfs4_state_end_reclaim_reboot(struct nfs_client *clp)
1793 {
1794         const struct nfs4_state_recovery_ops *ops;
1795         struct rpc_cred *cred;
1796         int err;
1797 
1798         if (!nfs4_state_clear_reclaim_reboot(clp))
1799                 return;
1800         ops = clp->cl_mvops->reboot_recovery_ops;
1801         cred = nfs4_get_clid_cred(clp);
1802         err = nfs4_reclaim_complete(clp, ops, cred);
1803         put_rpccred(cred);
1804         if (err == -NFS4ERR_CONN_NOT_BOUND_TO_SESSION)
1805                 set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1806 }
1807 
1808 static void nfs4_state_start_reclaim_nograce(struct nfs_client *clp)
1809 {
1810         nfs_mark_test_expired_all_delegations(clp);
1811         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_nograce);
1812 }
1813 
1814 static int nfs4_recovery_handle_error(struct nfs_client *clp, int error)
1815 {
1816         switch (error) {
1817         case 0:
1818                 break;
1819         case -NFS4ERR_CB_PATH_DOWN:
1820                 nfs40_handle_cb_pathdown(clp);
1821                 break;
1822         case -NFS4ERR_NO_GRACE:
1823                 nfs4_state_end_reclaim_reboot(clp);
1824                 break;
1825         case -NFS4ERR_STALE_CLIENTID:
1826                 set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1827                 nfs4_state_start_reclaim_reboot(clp);
1828                 break;
1829         case -NFS4ERR_EXPIRED:
1830                 set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1831                 nfs4_state_start_reclaim_nograce(clp);
1832                 break;
1833         case -NFS4ERR_BADSESSION:
1834         case -NFS4ERR_BADSLOT:
1835         case -NFS4ERR_BAD_HIGH_SLOT:
1836         case -NFS4ERR_DEADSESSION:
1837         case -NFS4ERR_SEQ_FALSE_RETRY:
1838         case -NFS4ERR_SEQ_MISORDERED:
1839                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
1840                 /* Zero session reset errors */
1841                 break;
1842         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1843                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
1844                 break;
1845         default:
1846                 dprintk("%s: failed to handle error %d for server %s\n",
1847                                 __func__, error, clp->cl_hostname);
1848                 return error;
1849         }
1850         dprintk("%s: handled error %d for server %s\n", __func__, error,
1851                         clp->cl_hostname);
1852         return 0;
1853 }
1854 
1855 static int nfs4_do_reclaim(struct nfs_client *clp, const struct nfs4_state_recovery_ops *ops)
1856 {
1857         struct nfs4_state_owner *sp;
1858         struct nfs_server *server;
1859         struct rb_node *pos;
1860         int status = 0;
1861 
1862 restart:
1863         rcu_read_lock();
1864         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
1865                 nfs4_purge_state_owners(server);
1866                 spin_lock(&clp->cl_lock);
1867                 for (pos = rb_first(&server->state_owners);
1868                      pos != NULL;
1869                      pos = rb_next(pos)) {
1870                         sp = rb_entry(pos,
1871                                 struct nfs4_state_owner, so_server_node);
1872                         if (!test_and_clear_bit(ops->owner_flag_bit,
1873                                                         &sp->so_flags))
1874                                 continue;
1875                         if (!atomic_inc_not_zero(&sp->so_count))
1876                                 continue;
1877                         spin_unlock(&clp->cl_lock);
1878                         rcu_read_unlock();
1879 
1880                         status = nfs4_reclaim_open_state(sp, ops);
1881                         if (status < 0) {
1882                                 set_bit(ops->owner_flag_bit, &sp->so_flags);
1883                                 nfs4_put_state_owner(sp);
1884                                 status = nfs4_recovery_handle_error(clp, status);
1885                                 return (status != 0) ? status : -EAGAIN;
1886                         }
1887 
1888                         nfs4_put_state_owner(sp);
1889                         goto restart;
1890                 }
1891                 spin_unlock(&clp->cl_lock);
1892         }
1893         rcu_read_unlock();
1894         return 0;
1895 }
1896 
1897 static int nfs4_check_lease(struct nfs_client *clp)
1898 {
1899         struct rpc_cred *cred;
1900         const struct nfs4_state_maintenance_ops *ops =
1901                 clp->cl_mvops->state_renewal_ops;
1902         int status;
1903 
1904         /* Is the client already known to have an expired lease? */
1905         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1906                 return 0;
1907         spin_lock(&clp->cl_lock);
1908         cred = ops->get_state_renewal_cred_locked(clp);
1909         spin_unlock(&clp->cl_lock);
1910         if (cred == NULL) {
1911                 cred = nfs4_get_clid_cred(clp);
1912                 status = -ENOKEY;
1913                 if (cred == NULL)
1914                         goto out;
1915         }
1916         status = ops->renew_lease(clp, cred);
1917         put_rpccred(cred);
1918         if (status == -ETIMEDOUT) {
1919                 set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1920                 return 0;
1921         }
1922 out:
1923         return nfs4_recovery_handle_error(clp, status);
1924 }
1925 
1926 /* Set NFS4CLNT_LEASE_EXPIRED and reclaim reboot state for all v4.0 errors
1927  * and for recoverable errors on EXCHANGE_ID for v4.1
1928  */
1929 static int nfs4_handle_reclaim_lease_error(struct nfs_client *clp, int status)
1930 {
1931         switch (status) {
1932         case -NFS4ERR_SEQ_MISORDERED:
1933                 if (test_and_set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state))
1934                         return -ESERVERFAULT;
1935                 /* Lease confirmation error: retry after purging the lease */
1936                 ssleep(1);
1937                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1938                 break;
1939         case -NFS4ERR_STALE_CLIENTID:
1940                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1941                 nfs4_state_start_reclaim_reboot(clp);
1942                 break;
1943         case -NFS4ERR_CLID_INUSE:
1944                 pr_err("NFS: Server %s reports our clientid is in use\n",
1945                         clp->cl_hostname);
1946                 nfs_mark_client_ready(clp, -EPERM);
1947                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1948                 return -EPERM;
1949         case -EACCES:
1950         case -NFS4ERR_DELAY:
1951         case -ETIMEDOUT:
1952         case -EAGAIN:
1953                 ssleep(1);
1954                 break;
1955 
1956         case -NFS4ERR_MINOR_VERS_MISMATCH:
1957                 if (clp->cl_cons_state == NFS_CS_SESSION_INITING)
1958                         nfs_mark_client_ready(clp, -EPROTONOSUPPORT);
1959                 dprintk("%s: exit with error %d for server %s\n",
1960                                 __func__, -EPROTONOSUPPORT, clp->cl_hostname);
1961                 return -EPROTONOSUPPORT;
1962         case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
1963                                  * in nfs4_exchange_id */
1964         default:
1965                 dprintk("%s: exit with error %d for server %s\n", __func__,
1966                                 status, clp->cl_hostname);
1967                 return status;
1968         }
1969         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1970         dprintk("%s: handled error %d for server %s\n", __func__, status,
1971                         clp->cl_hostname);
1972         return 0;
1973 }
1974 
1975 static int nfs4_establish_lease(struct nfs_client *clp)
1976 {
1977         struct rpc_cred *cred;
1978         const struct nfs4_state_recovery_ops *ops =
1979                 clp->cl_mvops->reboot_recovery_ops;
1980         int status;
1981 
1982         status = nfs4_begin_drain_session(clp);
1983         if (status != 0)
1984                 return status;
1985         cred = nfs4_get_clid_cred(clp);
1986         if (cred == NULL)
1987                 return -ENOENT;
1988         status = ops->establish_clid(clp, cred);
1989         put_rpccred(cred);
1990         if (status != 0)
1991                 return status;
1992         pnfs_destroy_all_layouts(clp);
1993         return 0;
1994 }
1995 
1996 /*
1997  * Returns zero or a negative errno.  NFS4ERR values are converted
1998  * to local errno values.
1999  */
2000 static int nfs4_reclaim_lease(struct nfs_client *clp)
2001 {
2002         int status;
2003 
2004         status = nfs4_establish_lease(clp);
2005         if (status < 0)
2006                 return nfs4_handle_reclaim_lease_error(clp, status);
2007         if (test_and_clear_bit(NFS4CLNT_SERVER_SCOPE_MISMATCH, &clp->cl_state))
2008                 nfs4_state_start_reclaim_nograce(clp);
2009         if (!test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state))
2010                 set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
2011         clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
2012         clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
2013         return 0;
2014 }
2015 
2016 static int nfs4_purge_lease(struct nfs_client *clp)
2017 {
2018         int status;
2019 
2020         status = nfs4_establish_lease(clp);
2021         if (status < 0)
2022                 return nfs4_handle_reclaim_lease_error(clp, status);
2023         clear_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
2024         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
2025         nfs4_state_start_reclaim_nograce(clp);
2026         return 0;
2027 }
2028 
2029 /*
2030  * Try remote migration of one FSID from a source server to a
2031  * destination server.  The source server provides a list of
2032  * potential destinations.
2033  *
2034  * Returns zero or a negative NFS4ERR status code.
2035  */
2036 static int nfs4_try_migration(struct nfs_server *server, struct rpc_cred *cred)
2037 {
2038         struct nfs_client *clp = server->nfs_client;
2039         struct nfs4_fs_locations *locations = NULL;
2040         struct inode *inode;
2041         struct page *page;
2042         int status, result;
2043 
2044         dprintk("--> %s: FSID %llx:%llx on \"%s\"\n", __func__,
2045                         (unsigned long long)server->fsid.major,
2046                         (unsigned long long)server->fsid.minor,
2047                         clp->cl_hostname);
2048 
2049         result = 0;
2050         page = alloc_page(GFP_KERNEL);
2051         locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
2052         if (page == NULL || locations == NULL) {
2053                 dprintk("<-- %s: no memory\n", __func__);
2054                 goto out;
2055         }
2056 
2057         inode = d_inode(server->super->s_root);
2058         result = nfs4_proc_get_locations(inode, locations, page, cred);
2059         if (result) {
2060                 dprintk("<-- %s: failed to retrieve fs_locations: %d\n",
2061                         __func__, result);
2062                 goto out;
2063         }
2064 
2065         result = -NFS4ERR_NXIO;
2066         if (!(locations->fattr.valid & NFS_ATTR_FATTR_V4_LOCATIONS)) {
2067                 dprintk("<-- %s: No fs_locations data, migration skipped\n",
2068                         __func__);
2069                 goto out;
2070         }
2071 
2072         status = nfs4_begin_drain_session(clp);
2073         if (status != 0)
2074                 return status;
2075 
2076         status = nfs4_replace_transport(server, locations);
2077         if (status != 0) {
2078                 dprintk("<-- %s: failed to replace transport: %d\n",
2079                         __func__, status);
2080                 goto out;
2081         }
2082 
2083         result = 0;
2084         dprintk("<-- %s: migration succeeded\n", __func__);
2085 
2086 out:
2087         if (page != NULL)
2088                 __free_page(page);
2089         kfree(locations);
2090         if (result) {
2091                 pr_err("NFS: migration recovery failed (server %s)\n",
2092                                 clp->cl_hostname);
2093                 set_bit(NFS_MIG_FAILED, &server->mig_status);
2094         }
2095         return result;
2096 }
2097 
2098 /*
2099  * Returns zero or a negative NFS4ERR status code.
2100  */
2101 static int nfs4_handle_migration(struct nfs_client *clp)
2102 {
2103         const struct nfs4_state_maintenance_ops *ops =
2104                                 clp->cl_mvops->state_renewal_ops;
2105         struct nfs_server *server;
2106         struct rpc_cred *cred;
2107 
2108         dprintk("%s: migration reported on \"%s\"\n", __func__,
2109                         clp->cl_hostname);
2110 
2111         spin_lock(&clp->cl_lock);
2112         cred = ops->get_state_renewal_cred_locked(clp);
2113         spin_unlock(&clp->cl_lock);
2114         if (cred == NULL)
2115                 return -NFS4ERR_NOENT;
2116 
2117         clp->cl_mig_gen++;
2118 restart:
2119         rcu_read_lock();
2120         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
2121                 int status;
2122 
2123                 if (server->mig_gen == clp->cl_mig_gen)
2124                         continue;
2125                 server->mig_gen = clp->cl_mig_gen;
2126 
2127                 if (!test_and_clear_bit(NFS_MIG_IN_TRANSITION,
2128                                                 &server->mig_status))
2129                         continue;
2130 
2131                 rcu_read_unlock();
2132                 status = nfs4_try_migration(server, cred);
2133                 if (status < 0) {
2134                         put_rpccred(cred);
2135                         return status;
2136                 }
2137                 goto restart;
2138         }
2139         rcu_read_unlock();
2140         put_rpccred(cred);
2141         return 0;
2142 }
2143 
2144 /*
2145  * Test each nfs_server on the clp's cl_superblocks list to see
2146  * if it's moved to another server.  Stop when the server no longer
2147  * returns NFS4ERR_LEASE_MOVED.
2148  */
2149 static int nfs4_handle_lease_moved(struct nfs_client *clp)
2150 {
2151         const struct nfs4_state_maintenance_ops *ops =
2152                                 clp->cl_mvops->state_renewal_ops;
2153         struct nfs_server *server;
2154         struct rpc_cred *cred;
2155 
2156         dprintk("%s: lease moved reported on \"%s\"\n", __func__,
2157                         clp->cl_hostname);
2158 
2159         spin_lock(&clp->cl_lock);
2160         cred = ops->get_state_renewal_cred_locked(clp);
2161         spin_unlock(&clp->cl_lock);
2162         if (cred == NULL)
2163                 return -NFS4ERR_NOENT;
2164 
2165         clp->cl_mig_gen++;
2166 restart:
2167         rcu_read_lock();
2168         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
2169                 struct inode *inode;
2170                 int status;
2171 
2172                 if (server->mig_gen == clp->cl_mig_gen)
2173                         continue;
2174                 server->mig_gen = clp->cl_mig_gen;
2175 
2176                 rcu_read_unlock();
2177 
2178                 inode = d_inode(server->super->s_root);
2179                 status = nfs4_proc_fsid_present(inode, cred);
2180                 if (status != -NFS4ERR_MOVED)
2181                         goto restart;   /* wasn't this one */
2182                 if (nfs4_try_migration(server, cred) == -NFS4ERR_LEASE_MOVED)
2183                         goto restart;   /* there are more */
2184                 goto out;
2185         }
2186         rcu_read_unlock();
2187 
2188 out:
2189         put_rpccred(cred);
2190         return 0;
2191 }
2192 
2193 /**
2194  * nfs4_discover_server_trunking - Detect server IP address trunking
2195  *
2196  * @clp: nfs_client under test
2197  * @result: OUT: found nfs_client, or clp
2198  *
2199  * Returns zero or a negative errno.  If zero is returned,
2200  * an nfs_client pointer is planted in "result".
2201  *
2202  * Note: since we are invoked in process context, and
2203  * not from inside the state manager, we cannot use
2204  * nfs4_handle_reclaim_lease_error().
2205  */
2206 int nfs4_discover_server_trunking(struct nfs_client *clp,
2207                                   struct nfs_client **result)
2208 {
2209         const struct nfs4_state_recovery_ops *ops =
2210                                 clp->cl_mvops->reboot_recovery_ops;
2211         struct rpc_clnt *clnt;
2212         struct rpc_cred *cred;
2213         int i, status;
2214 
2215         dprintk("NFS: %s: testing '%s'\n", __func__, clp->cl_hostname);
2216 
2217         clnt = clp->cl_rpcclient;
2218         i = 0;
2219 
2220         mutex_lock(&nfs_clid_init_mutex);
2221 again:
2222         status  = -ENOENT;
2223         cred = nfs4_get_clid_cred(clp);
2224         if (cred == NULL)
2225                 goto out_unlock;
2226 
2227         status = ops->detect_trunking(clp, result, cred);
2228         put_rpccred(cred);
2229         switch (status) {
2230         case 0:
2231         case -EINTR:
2232         case -ERESTARTSYS:
2233                 break;
2234         case -ETIMEDOUT:
2235                 if (clnt->cl_softrtry)
2236                         break;
2237                 /* Fall through */
2238         case -NFS4ERR_DELAY:
2239         case -EAGAIN:
2240                 ssleep(1);
2241                 /* Fall through */
2242         case -NFS4ERR_STALE_CLIENTID:
2243                 dprintk("NFS: %s after status %d, retrying\n",
2244                         __func__, status);
2245                 goto again;
2246         case -EACCES:
2247                 if (i++ == 0) {
2248                         nfs4_root_machine_cred(clp);
2249                         goto again;
2250                 }
2251                 if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX)
2252                         break;
2253                 /* Fall through */
2254         case -NFS4ERR_CLID_INUSE:
2255         case -NFS4ERR_WRONGSEC:
2256                 /* No point in retrying if we already used RPC_AUTH_UNIX */
2257                 if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX) {
2258                         status = -EPERM;
2259                         break;
2260                 }
2261                 clnt = rpc_clone_client_set_auth(clnt, RPC_AUTH_UNIX);
2262                 if (IS_ERR(clnt)) {
2263                         status = PTR_ERR(clnt);
2264                         break;
2265                 }
2266                 /* Note: this is safe because we haven't yet marked the
2267                  * client as ready, so we are the only user of
2268                  * clp->cl_rpcclient
2269                  */
2270                 clnt = xchg(&clp->cl_rpcclient, clnt);
2271                 rpc_shutdown_client(clnt);
2272                 clnt = clp->cl_rpcclient;
2273                 goto again;
2274 
2275         case -NFS4ERR_MINOR_VERS_MISMATCH:
2276                 status = -EPROTONOSUPPORT;
2277                 break;
2278 
2279         case -EKEYEXPIRED:
2280         case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
2281                                  * in nfs4_exchange_id */
2282                 status = -EKEYEXPIRED;
2283                 break;
2284         default:
2285                 pr_warn("NFS: %s unhandled error %d. Exiting with error EIO\n",
2286                                 __func__, status);
2287                 status = -EIO;
2288         }
2289 
2290 out_unlock:
2291         mutex_unlock(&nfs_clid_init_mutex);
2292         dprintk("NFS: %s: status = %d\n", __func__, status);
2293         return status;
2294 }
2295 
2296 #ifdef CONFIG_NFS_V4_1
2297 void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
2298 {
2299         struct nfs_client *clp = session->clp;
2300 
2301         switch (err) {
2302         default:
2303                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2304                 break;
2305         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
2306                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2307         }
2308         nfs4_schedule_state_manager(clp);
2309 }
2310 EXPORT_SYMBOL_GPL(nfs4_schedule_session_recovery);
2311 
2312 void nfs41_notify_server(struct nfs_client *clp)
2313 {
2314         /* Use CHECK_LEASE to ping the server with a SEQUENCE */
2315         set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
2316         nfs4_schedule_state_manager(clp);
2317 }
2318 
2319 static void nfs4_reset_all_state(struct nfs_client *clp)
2320 {
2321         if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2322                 set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
2323                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
2324                 nfs4_state_start_reclaim_nograce(clp);
2325                 dprintk("%s: scheduling reset of all state for server %s!\n",
2326                                 __func__, clp->cl_hostname);
2327                 nfs4_schedule_state_manager(clp);
2328         }
2329 }
2330 
2331 static void nfs41_handle_server_reboot(struct nfs_client *clp)
2332 {
2333         if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2334                 nfs4_state_start_reclaim_reboot(clp);
2335                 dprintk("%s: server %s rebooted!\n", __func__,
2336                                 clp->cl_hostname);
2337                 nfs4_schedule_state_manager(clp);
2338         }
2339 }
2340 
2341 static void nfs41_handle_all_state_revoked(struct nfs_client *clp)
2342 {
2343         nfs4_reset_all_state(clp);
2344         dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2345 }
2346 
2347 static void nfs41_handle_some_state_revoked(struct nfs_client *clp)
2348 {
2349         nfs4_state_start_reclaim_nograce(clp);
2350         nfs4_schedule_state_manager(clp);
2351 
2352         dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2353 }
2354 
2355 static void nfs41_handle_recallable_state_revoked(struct nfs_client *clp)
2356 {
2357         /* FIXME: For now, we destroy all layouts. */
2358         pnfs_destroy_all_layouts(clp);
2359         /* FIXME: For now, we test all delegations+open state+locks. */
2360         nfs41_handle_some_state_revoked(clp);
2361         dprintk("%s: Recallable state revoked on server %s!\n", __func__,
2362                         clp->cl_hostname);
2363 }
2364 
2365 static void nfs41_handle_backchannel_fault(struct nfs_client *clp)
2366 {
2367         set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2368         nfs4_schedule_state_manager(clp);
2369 
2370         dprintk("%s: server %s declared a backchannel fault\n", __func__,
2371                         clp->cl_hostname);
2372 }
2373 
2374 static void nfs41_handle_cb_path_down(struct nfs_client *clp)
2375 {
2376         if (test_and_set_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2377                 &clp->cl_state) == 0)
2378                 nfs4_schedule_state_manager(clp);
2379 }
2380 
2381 void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags,
2382                 bool recovery)
2383 {
2384         if (!flags)
2385                 return;
2386 
2387         dprintk("%s: \"%s\" (client ID %llx) flags=0x%08x\n",
2388                 __func__, clp->cl_hostname, clp->cl_clientid, flags);
2389         /*
2390          * If we're called from the state manager thread, then assume we're
2391          * already handling the RECLAIM_NEEDED and/or STATE_REVOKED.
2392          * Those flags are expected to remain set until we're done
2393          * recovering (see RFC5661, section 18.46.3).
2394          */
2395         if (recovery)
2396                 goto out_recovery;
2397 
2398         if (flags & SEQ4_STATUS_RESTART_RECLAIM_NEEDED)
2399                 nfs41_handle_server_reboot(clp);
2400         if (flags & (SEQ4_STATUS_EXPIRED_ALL_STATE_REVOKED))
2401                 nfs41_handle_all_state_revoked(clp);
2402         if (flags & (SEQ4_STATUS_EXPIRED_SOME_STATE_REVOKED |
2403                             SEQ4_STATUS_ADMIN_STATE_REVOKED))
2404                 nfs41_handle_some_state_revoked(clp);
2405         if (flags & SEQ4_STATUS_LEASE_MOVED)
2406                 nfs4_schedule_lease_moved_recovery(clp);
2407         if (flags & SEQ4_STATUS_RECALLABLE_STATE_REVOKED)
2408                 nfs41_handle_recallable_state_revoked(clp);
2409 out_recovery:
2410         if (flags & SEQ4_STATUS_BACKCHANNEL_FAULT)
2411                 nfs41_handle_backchannel_fault(clp);
2412         else if (flags & (SEQ4_STATUS_CB_PATH_DOWN |
2413                                 SEQ4_STATUS_CB_PATH_DOWN_SESSION))
2414                 nfs41_handle_cb_path_down(clp);
2415 }
2416 
2417 static int nfs4_reset_session(struct nfs_client *clp)
2418 {
2419         struct rpc_cred *cred;
2420         int status;
2421 
2422         if (!nfs4_has_session(clp))
2423                 return 0;
2424         status = nfs4_begin_drain_session(clp);
2425         if (status != 0)
2426                 return status;
2427         cred = nfs4_get_clid_cred(clp);
2428         status = nfs4_proc_destroy_session(clp->cl_session, cred);
2429         switch (status) {
2430         case 0:
2431         case -NFS4ERR_BADSESSION:
2432         case -NFS4ERR_DEADSESSION:
2433                 break;
2434         case -NFS4ERR_BACK_CHAN_BUSY:
2435         case -NFS4ERR_DELAY:
2436                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2437                 status = 0;
2438                 ssleep(1);
2439                 goto out;
2440         default:
2441                 status = nfs4_recovery_handle_error(clp, status);
2442                 goto out;
2443         }
2444 
2445         memset(clp->cl_session->sess_id.data, 0, NFS4_MAX_SESSIONID_LEN);
2446         status = nfs4_proc_create_session(clp, cred);
2447         if (status) {
2448                 dprintk("%s: session reset failed with status %d for server %s!\n",
2449                         __func__, status, clp->cl_hostname);
2450                 status = nfs4_handle_reclaim_lease_error(clp, status);
2451                 goto out;
2452         }
2453         nfs41_finish_session_reset(clp);
2454         dprintk("%s: session reset was successful for server %s!\n",
2455                         __func__, clp->cl_hostname);
2456 out:
2457         if (cred)
2458                 put_rpccred(cred);
2459         return status;
2460 }
2461 
2462 static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2463 {
2464         struct rpc_cred *cred;
2465         int ret;
2466 
2467         if (!nfs4_has_session(clp))
2468                 return 0;
2469         ret = nfs4_begin_drain_session(clp);
2470         if (ret != 0)
2471                 return ret;
2472         cred = nfs4_get_clid_cred(clp);
2473         ret = nfs4_proc_bind_conn_to_session(clp, cred);
2474         if (cred)
2475                 put_rpccred(cred);
2476         clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2477         switch (ret) {
2478         case 0:
2479                 dprintk("%s: bind_conn_to_session was successful for server %s!\n",
2480                         __func__, clp->cl_hostname);
2481                 break;
2482         case -NFS4ERR_DELAY:
2483                 ssleep(1);
2484                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2485                 break;
2486         default:
2487                 return nfs4_recovery_handle_error(clp, ret);
2488         }
2489         return 0;
2490 }
2491 #else /* CONFIG_NFS_V4_1 */
2492 static int nfs4_reset_session(struct nfs_client *clp) { return 0; }
2493 
2494 static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2495 {
2496         return 0;
2497 }
2498 #endif /* CONFIG_NFS_V4_1 */
2499 
2500 static void nfs4_state_manager(struct nfs_client *clp)
2501 {
2502         int status = 0;
2503         const char *section = "", *section_sep = "";
2504 
2505         /* Ensure exclusive access to NFSv4 state */
2506         do {
2507                 clear_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
2508                 if (test_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state)) {
2509                         section = "purge state";
2510                         status = nfs4_purge_lease(clp);
2511                         if (status < 0)
2512                                 goto out_error;
2513                         continue;
2514                 }
2515 
2516                 if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state)) {
2517                         section = "lease expired";
2518                         /* We're going to have to re-establish a clientid */
2519                         status = nfs4_reclaim_lease(clp);
2520                         if (status < 0)
2521                                 goto out_error;
2522                         continue;
2523                 }
2524 
2525                 /* Initialize or reset the session */
2526                 if (test_and_clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state)) {
2527                         section = "reset session";
2528                         status = nfs4_reset_session(clp);
2529                         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
2530                                 continue;
2531                         if (status < 0)
2532                                 goto out_error;
2533                 }
2534 
2535                 /* Send BIND_CONN_TO_SESSION */
2536                 if (test_and_clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2537                                 &clp->cl_state)) {
2538                         section = "bind conn to session";
2539                         status = nfs4_bind_conn_to_session(clp);
2540                         if (status < 0)
2541                                 goto out_error;
2542                         continue;
2543                 }
2544 
2545                 if (test_and_clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state)) {
2546                         section = "check lease";
2547                         status = nfs4_check_lease(clp);
2548                         if (status < 0)
2549                                 goto out_error;
2550                         continue;
2551                 }
2552 
2553                 if (test_and_clear_bit(NFS4CLNT_MOVED, &clp->cl_state)) {
2554                         section = "migration";
2555                         status = nfs4_handle_migration(clp);
2556                         if (status < 0)
2557                                 goto out_error;
2558                 }
2559 
2560                 if (test_and_clear_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state)) {
2561                         section = "lease moved";
2562                         status = nfs4_handle_lease_moved(clp);
2563                         if (status < 0)
2564                                 goto out_error;
2565                 }
2566 
2567                 /* First recover reboot state... */
2568                 if (test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state)) {
2569                         section = "reclaim reboot";
2570                         status = nfs4_do_reclaim(clp,
2571                                 clp->cl_mvops->reboot_recovery_ops);
2572                         if (status == -EAGAIN)
2573                                 continue;
2574                         if (status < 0)
2575                                 goto out_error;
2576                         nfs4_state_end_reclaim_reboot(clp);
2577                 }
2578 
2579                 /* Detect expired delegations... */
2580                 if (test_and_clear_bit(NFS4CLNT_DELEGATION_EXPIRED, &clp->cl_state)) {
2581                         section = "detect expired delegations";
2582                         nfs_reap_expired_delegations(clp);
2583                         continue;
2584                 }
2585 
2586                 /* Now recover expired state... */
2587                 if (test_and_clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state)) {
2588                         section = "reclaim nograce";
2589                         status = nfs4_do_reclaim(clp,
2590                                 clp->cl_mvops->nograce_recovery_ops);
2591                         if (status == -EAGAIN)
2592                                 continue;
2593                         if (status < 0)
2594                                 goto out_error;
2595                 }
2596 
2597                 nfs4_end_drain_session(clp);
2598                 nfs4_clear_state_manager_bit(clp);
2599 
2600                 if (!test_and_set_bit(NFS4CLNT_DELEGRETURN_RUNNING, &clp->cl_state)) {
2601                         if (test_and_clear_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) {
2602                                 nfs_client_return_marked_delegations(clp);
2603                                 set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
2604                         }
2605                         clear_bit(NFS4CLNT_DELEGRETURN_RUNNING, &clp->cl_state);
2606                 }
2607 
2608                 /* Did we race with an attempt to give us more work? */
2609                 if (!test_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state))
2610                         return;
2611                 if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
2612                         return;
2613         } while (refcount_read(&clp->cl_count) > 1 && !signalled());
2614         goto out_drain;
2615 
2616 out_error:
2617         if (strlen(section))
2618                 section_sep = ": ";
2619         pr_warn_ratelimited("NFS: state manager%s%s failed on NFSv4 server %s"
2620                         " with error %d\n", section_sep, section,
2621                         clp->cl_hostname, -status);
2622         ssleep(1);
2623 out_drain:
2624         nfs4_end_drain_session(clp);
2625         nfs4_clear_state_manager_bit(clp);
2626 }
2627 
2628 static int nfs4_run_state_manager(void *ptr)
2629 {
2630         struct nfs_client *clp = ptr;
2631 
2632         allow_signal(SIGKILL);
2633         nfs4_state_manager(clp);
2634         nfs_put_client(clp);
2635         module_put_and_exit(0);
2636         return 0;
2637 }
2638 
2639 /*
2640  * Local variables:
2641  *  c-basic-offset: 8
2642  * End:
2643  */
2644 

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