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TOMOYO Linux Cross Reference
Linux/fs/nfs/nfs4state.c

Version: ~ [ linux-5.6-rc7 ] ~ [ linux-5.5.11 ] ~ [ linux-5.4.27 ] ~ [ linux-5.3.18 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.112 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.174 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.217 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.217 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.82 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
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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 static DEFINE_MUTEX(nfs_clid_init_mutex);
 70 
 71 int nfs4_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
 72 {
 73         struct nfs4_setclientid_res clid = {
 74                 .clientid = clp->cl_clientid,
 75                 .confirm = clp->cl_confirm,
 76         };
 77         unsigned short port;
 78         int status;
 79         struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
 80 
 81         if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
 82                 goto do_confirm;
 83         port = nn->nfs_callback_tcpport;
 84         if (clp->cl_addr.ss_family == AF_INET6)
 85                 port = nn->nfs_callback_tcpport6;
 86 
 87         status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
 88         if (status != 0)
 89                 goto out;
 90         clp->cl_clientid = clid.clientid;
 91         clp->cl_confirm = clid.confirm;
 92         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 93 do_confirm:
 94         status = nfs4_proc_setclientid_confirm(clp, &clid, cred);
 95         if (status != 0)
 96                 goto out;
 97         clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
 98         nfs4_schedule_state_renewal(clp);
 99 out:
100         return status;
101 }
102 
103 /**
104  * nfs40_discover_server_trunking - Detect server IP address trunking (mv0)
105  *
106  * @clp: nfs_client under test
107  * @result: OUT: found nfs_client, or clp
108  * @cred: credential to use for trunking test
109  *
110  * Returns zero, a negative errno, or a negative NFS4ERR status.
111  * If zero is returned, an nfs_client pointer is planted in
112  * "result".
113  *
114  * Note: The returned client may not yet be marked ready.
115  */
116 int nfs40_discover_server_trunking(struct nfs_client *clp,
117                                    struct nfs_client **result,
118                                    struct rpc_cred *cred)
119 {
120         struct nfs4_setclientid_res clid = {
121                 .clientid = clp->cl_clientid,
122                 .confirm = clp->cl_confirm,
123         };
124         struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
125         unsigned short port;
126         int status;
127 
128         port = nn->nfs_callback_tcpport;
129         if (clp->cl_addr.ss_family == AF_INET6)
130                 port = nn->nfs_callback_tcpport6;
131 
132         status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
133         if (status != 0)
134                 goto out;
135         clp->cl_clientid = clid.clientid;
136         clp->cl_confirm = clid.confirm;
137 
138         status = nfs40_walk_client_list(clp, result, cred);
139         if (status == 0) {
140                 /* Sustain the lease, even if it's empty.  If the clientid4
141                  * goes stale it's of no use for trunking discovery. */
142                 nfs4_schedule_state_renewal(*result);
143         }
144 out:
145         return status;
146 }
147 
148 struct rpc_cred *nfs4_get_machine_cred_locked(struct nfs_client *clp)
149 {
150         struct rpc_cred *cred = NULL;
151 
152         if (clp->cl_machine_cred != NULL)
153                 cred = get_rpccred(clp->cl_machine_cred);
154         return cred;
155 }
156 
157 static void nfs4_root_machine_cred(struct nfs_client *clp)
158 {
159         struct rpc_cred *cred, *new;
160 
161         new = rpc_lookup_machine_cred(NULL);
162         spin_lock(&clp->cl_lock);
163         cred = clp->cl_machine_cred;
164         clp->cl_machine_cred = new;
165         spin_unlock(&clp->cl_lock);
166         if (cred != NULL)
167                 put_rpccred(cred);
168 }
169 
170 static struct rpc_cred *
171 nfs4_get_renew_cred_server_locked(struct nfs_server *server)
172 {
173         struct rpc_cred *cred = NULL;
174         struct nfs4_state_owner *sp;
175         struct rb_node *pos;
176 
177         for (pos = rb_first(&server->state_owners);
178              pos != NULL;
179              pos = rb_next(pos)) {
180                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
181                 if (list_empty(&sp->so_states))
182                         continue;
183                 cred = get_rpccred(sp->so_cred);
184                 break;
185         }
186         return cred;
187 }
188 
189 /**
190  * nfs4_get_renew_cred_locked - Acquire credential for a renew operation
191  * @clp: client state handle
192  *
193  * Returns an rpc_cred with reference count bumped, or NULL.
194  * Caller must hold clp->cl_lock.
195  */
196 struct rpc_cred *nfs4_get_renew_cred_locked(struct nfs_client *clp)
197 {
198         struct rpc_cred *cred = NULL;
199         struct nfs_server *server;
200 
201         /* Use machine credentials if available */
202         cred = nfs4_get_machine_cred_locked(clp);
203         if (cred != NULL)
204                 goto out;
205 
206         rcu_read_lock();
207         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
208                 cred = nfs4_get_renew_cred_server_locked(server);
209                 if (cred != NULL)
210                         break;
211         }
212         rcu_read_unlock();
213 
214 out:
215         return cred;
216 }
217 
218 static void nfs4_end_drain_slot_table(struct nfs4_slot_table *tbl)
219 {
220         if (test_and_clear_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state)) {
221                 spin_lock(&tbl->slot_tbl_lock);
222                 nfs41_wake_slot_table(tbl);
223                 spin_unlock(&tbl->slot_tbl_lock);
224         }
225 }
226 
227 static void nfs4_end_drain_session(struct nfs_client *clp)
228 {
229         struct nfs4_session *ses = clp->cl_session;
230 
231         if (clp->cl_slot_tbl) {
232                 nfs4_end_drain_slot_table(clp->cl_slot_tbl);
233                 return;
234         }
235 
236         if (ses != NULL) {
237                 nfs4_end_drain_slot_table(&ses->bc_slot_table);
238                 nfs4_end_drain_slot_table(&ses->fc_slot_table);
239         }
240 }
241 
242 static int nfs4_drain_slot_tbl(struct nfs4_slot_table *tbl)
243 {
244         set_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
245         spin_lock(&tbl->slot_tbl_lock);
246         if (tbl->highest_used_slotid != NFS4_NO_SLOT) {
247                 reinit_completion(&tbl->complete);
248                 spin_unlock(&tbl->slot_tbl_lock);
249                 return wait_for_completion_interruptible(&tbl->complete);
250         }
251         spin_unlock(&tbl->slot_tbl_lock);
252         return 0;
253 }
254 
255 static int nfs4_begin_drain_session(struct nfs_client *clp)
256 {
257         struct nfs4_session *ses = clp->cl_session;
258         int ret = 0;
259 
260         if (clp->cl_slot_tbl)
261                 return nfs4_drain_slot_tbl(clp->cl_slot_tbl);
262 
263         /* back channel */
264         ret = nfs4_drain_slot_tbl(&ses->bc_slot_table);
265         if (ret)
266                 return ret;
267         /* fore channel */
268         return nfs4_drain_slot_tbl(&ses->fc_slot_table);
269 }
270 
271 #if defined(CONFIG_NFS_V4_1)
272 
273 static int nfs41_setup_state_renewal(struct nfs_client *clp)
274 {
275         int status;
276         struct nfs_fsinfo fsinfo;
277 
278         if (!test_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state)) {
279                 nfs4_schedule_state_renewal(clp);
280                 return 0;
281         }
282 
283         status = nfs4_proc_get_lease_time(clp, &fsinfo);
284         if (status == 0) {
285                 /* Update lease time and schedule renewal */
286                 spin_lock(&clp->cl_lock);
287                 clp->cl_lease_time = fsinfo.lease_time * HZ;
288                 clp->cl_last_renewal = jiffies;
289                 spin_unlock(&clp->cl_lock);
290 
291                 nfs4_schedule_state_renewal(clp);
292         }
293 
294         return status;
295 }
296 
297 static void nfs41_finish_session_reset(struct nfs_client *clp)
298 {
299         clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
300         clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
301         /* create_session negotiated new slot table */
302         clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
303         nfs41_setup_state_renewal(clp);
304 }
305 
306 int nfs41_init_clientid(struct nfs_client *clp, struct rpc_cred *cred)
307 {
308         int status;
309 
310         if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
311                 goto do_confirm;
312         status = nfs4_proc_exchange_id(clp, cred);
313         if (status != 0)
314                 goto out;
315         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
316 do_confirm:
317         status = nfs4_proc_create_session(clp, cred);
318         if (status != 0)
319                 goto out;
320         nfs41_finish_session_reset(clp);
321         nfs_mark_client_ready(clp, NFS_CS_READY);
322 out:
323         return status;
324 }
325 
326 /**
327  * nfs41_discover_server_trunking - Detect server IP address trunking (mv1)
328  *
329  * @clp: nfs_client under test
330  * @result: OUT: found nfs_client, or clp
331  * @cred: credential to use for trunking test
332  *
333  * Returns NFS4_OK, a negative errno, or a negative NFS4ERR status.
334  * If NFS4_OK is returned, an nfs_client pointer is planted in
335  * "result".
336  *
337  * Note: The returned client may not yet be marked ready.
338  */
339 int nfs41_discover_server_trunking(struct nfs_client *clp,
340                                    struct nfs_client **result,
341                                    struct rpc_cred *cred)
342 {
343         int status;
344 
345         status = nfs4_proc_exchange_id(clp, cred);
346         if (status != NFS4_OK)
347                 return status;
348 
349         status = nfs41_walk_client_list(clp, result, cred);
350         if (status < 0)
351                 return status;
352         if (clp != *result)
353                 return 0;
354 
355         /* Purge state if the client id was established in a prior instance */
356         if (clp->cl_exchange_flags & EXCHGID4_FLAG_CONFIRMED_R)
357                 set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
358         else
359                 set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
360         nfs4_schedule_state_manager(clp);
361         status = nfs_wait_client_init_complete(clp);
362         if (status < 0)
363                 nfs_put_client(clp);
364         return status;
365 }
366 
367 #endif /* CONFIG_NFS_V4_1 */
368 
369 /**
370  * nfs4_get_clid_cred - Acquire credential for a setclientid operation
371  * @clp: client state handle
372  *
373  * Returns an rpc_cred with reference count bumped, or NULL.
374  */
375 struct rpc_cred *nfs4_get_clid_cred(struct nfs_client *clp)
376 {
377         struct rpc_cred *cred;
378 
379         spin_lock(&clp->cl_lock);
380         cred = nfs4_get_machine_cred_locked(clp);
381         spin_unlock(&clp->cl_lock);
382         return cred;
383 }
384 
385 static struct nfs4_state_owner *
386 nfs4_find_state_owner_locked(struct nfs_server *server, struct rpc_cred *cred)
387 {
388         struct rb_node **p = &server->state_owners.rb_node,
389                        *parent = NULL;
390         struct nfs4_state_owner *sp;
391 
392         while (*p != NULL) {
393                 parent = *p;
394                 sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
395 
396                 if (cred < sp->so_cred)
397                         p = &parent->rb_left;
398                 else if (cred > sp->so_cred)
399                         p = &parent->rb_right;
400                 else {
401                         if (!list_empty(&sp->so_lru))
402                                 list_del_init(&sp->so_lru);
403                         atomic_inc(&sp->so_count);
404                         return sp;
405                 }
406         }
407         return NULL;
408 }
409 
410 static struct nfs4_state_owner *
411 nfs4_insert_state_owner_locked(struct nfs4_state_owner *new)
412 {
413         struct nfs_server *server = new->so_server;
414         struct rb_node **p = &server->state_owners.rb_node,
415                        *parent = NULL;
416         struct nfs4_state_owner *sp;
417         int err;
418 
419         while (*p != NULL) {
420                 parent = *p;
421                 sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
422 
423                 if (new->so_cred < sp->so_cred)
424                         p = &parent->rb_left;
425                 else if (new->so_cred > sp->so_cred)
426                         p = &parent->rb_right;
427                 else {
428                         if (!list_empty(&sp->so_lru))
429                                 list_del_init(&sp->so_lru);
430                         atomic_inc(&sp->so_count);
431                         return sp;
432                 }
433         }
434         err = ida_get_new(&server->openowner_id, &new->so_seqid.owner_id);
435         if (err)
436                 return ERR_PTR(err);
437         rb_link_node(&new->so_server_node, parent, p);
438         rb_insert_color(&new->so_server_node, &server->state_owners);
439         return new;
440 }
441 
442 static void
443 nfs4_remove_state_owner_locked(struct nfs4_state_owner *sp)
444 {
445         struct nfs_server *server = sp->so_server;
446 
447         if (!RB_EMPTY_NODE(&sp->so_server_node))
448                 rb_erase(&sp->so_server_node, &server->state_owners);
449         ida_remove(&server->openowner_id, sp->so_seqid.owner_id);
450 }
451 
452 static void
453 nfs4_init_seqid_counter(struct nfs_seqid_counter *sc)
454 {
455         sc->create_time = ktime_get();
456         sc->flags = 0;
457         sc->counter = 0;
458         spin_lock_init(&sc->lock);
459         INIT_LIST_HEAD(&sc->list);
460         rpc_init_wait_queue(&sc->wait, "Seqid_waitqueue");
461 }
462 
463 static void
464 nfs4_destroy_seqid_counter(struct nfs_seqid_counter *sc)
465 {
466         rpc_destroy_wait_queue(&sc->wait);
467 }
468 
469 /*
470  * nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
471  * create a new state_owner.
472  *
473  */
474 static struct nfs4_state_owner *
475 nfs4_alloc_state_owner(struct nfs_server *server,
476                 struct rpc_cred *cred,
477                 gfp_t gfp_flags)
478 {
479         struct nfs4_state_owner *sp;
480 
481         sp = kzalloc(sizeof(*sp), gfp_flags);
482         if (!sp)
483                 return NULL;
484         sp->so_server = server;
485         sp->so_cred = get_rpccred(cred);
486         spin_lock_init(&sp->so_lock);
487         INIT_LIST_HEAD(&sp->so_states);
488         nfs4_init_seqid_counter(&sp->so_seqid);
489         atomic_set(&sp->so_count, 1);
490         INIT_LIST_HEAD(&sp->so_lru);
491         seqcount_init(&sp->so_reclaim_seqcount);
492         mutex_init(&sp->so_delegreturn_mutex);
493         return sp;
494 }
495 
496 static void
497 nfs4_drop_state_owner(struct nfs4_state_owner *sp)
498 {
499         struct rb_node *rb_node = &sp->so_server_node;
500 
501         if (!RB_EMPTY_NODE(rb_node)) {
502                 struct nfs_server *server = sp->so_server;
503                 struct nfs_client *clp = server->nfs_client;
504 
505                 spin_lock(&clp->cl_lock);
506                 if (!RB_EMPTY_NODE(rb_node)) {
507                         rb_erase(rb_node, &server->state_owners);
508                         RB_CLEAR_NODE(rb_node);
509                 }
510                 spin_unlock(&clp->cl_lock);
511         }
512 }
513 
514 static void nfs4_free_state_owner(struct nfs4_state_owner *sp)
515 {
516         nfs4_destroy_seqid_counter(&sp->so_seqid);
517         put_rpccred(sp->so_cred);
518         kfree(sp);
519 }
520 
521 static void nfs4_gc_state_owners(struct nfs_server *server)
522 {
523         struct nfs_client *clp = server->nfs_client;
524         struct nfs4_state_owner *sp, *tmp;
525         unsigned long time_min, time_max;
526         LIST_HEAD(doomed);
527 
528         spin_lock(&clp->cl_lock);
529         time_max = jiffies;
530         time_min = (long)time_max - (long)clp->cl_lease_time;
531         list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
532                 /* NB: LRU is sorted so that oldest is at the head */
533                 if (time_in_range(sp->so_expires, time_min, time_max))
534                         break;
535                 list_move(&sp->so_lru, &doomed);
536                 nfs4_remove_state_owner_locked(sp);
537         }
538         spin_unlock(&clp->cl_lock);
539 
540         list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
541                 list_del(&sp->so_lru);
542                 nfs4_free_state_owner(sp);
543         }
544 }
545 
546 /**
547  * nfs4_get_state_owner - Look up a state owner given a credential
548  * @server: nfs_server to search
549  * @cred: RPC credential to match
550  *
551  * Returns a pointer to an instantiated nfs4_state_owner struct, or NULL.
552  */
553 struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server,
554                                               struct rpc_cred *cred,
555                                               gfp_t gfp_flags)
556 {
557         struct nfs_client *clp = server->nfs_client;
558         struct nfs4_state_owner *sp, *new;
559 
560         spin_lock(&clp->cl_lock);
561         sp = nfs4_find_state_owner_locked(server, cred);
562         spin_unlock(&clp->cl_lock);
563         if (sp != NULL)
564                 goto out;
565         new = nfs4_alloc_state_owner(server, cred, gfp_flags);
566         if (new == NULL)
567                 goto out;
568         do {
569                 if (ida_pre_get(&server->openowner_id, gfp_flags) == 0)
570                         break;
571                 spin_lock(&clp->cl_lock);
572                 sp = nfs4_insert_state_owner_locked(new);
573                 spin_unlock(&clp->cl_lock);
574         } while (sp == ERR_PTR(-EAGAIN));
575         if (sp != new)
576                 nfs4_free_state_owner(new);
577 out:
578         nfs4_gc_state_owners(server);
579         return sp;
580 }
581 
582 /**
583  * nfs4_put_state_owner - Release a nfs4_state_owner
584  * @sp: state owner data to release
585  *
586  * Note that we keep released state owners on an LRU
587  * list.
588  * This caches valid state owners so that they can be
589  * reused, to avoid the OPEN_CONFIRM on minor version 0.
590  * It also pins the uniquifier of dropped state owners for
591  * a while, to ensure that those state owner names are
592  * never reused.
593  */
594 void nfs4_put_state_owner(struct nfs4_state_owner *sp)
595 {
596         struct nfs_server *server = sp->so_server;
597         struct nfs_client *clp = server->nfs_client;
598 
599         if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
600                 return;
601 
602         sp->so_expires = jiffies;
603         list_add_tail(&sp->so_lru, &server->state_owners_lru);
604         spin_unlock(&clp->cl_lock);
605 }
606 
607 /**
608  * nfs4_purge_state_owners - Release all cached state owners
609  * @server: nfs_server with cached state owners to release
610  *
611  * Called at umount time.  Remaining state owners will be on
612  * the LRU with ref count of zero.
613  */
614 void nfs4_purge_state_owners(struct nfs_server *server)
615 {
616         struct nfs_client *clp = server->nfs_client;
617         struct nfs4_state_owner *sp, *tmp;
618         LIST_HEAD(doomed);
619 
620         spin_lock(&clp->cl_lock);
621         list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
622                 list_move(&sp->so_lru, &doomed);
623                 nfs4_remove_state_owner_locked(sp);
624         }
625         spin_unlock(&clp->cl_lock);
626 
627         list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
628                 list_del(&sp->so_lru);
629                 nfs4_free_state_owner(sp);
630         }
631 }
632 
633 static struct nfs4_state *
634 nfs4_alloc_open_state(void)
635 {
636         struct nfs4_state *state;
637 
638         state = kzalloc(sizeof(*state), GFP_NOFS);
639         if (!state)
640                 return NULL;
641         atomic_set(&state->count, 1);
642         INIT_LIST_HEAD(&state->lock_states);
643         spin_lock_init(&state->state_lock);
644         seqlock_init(&state->seqlock);
645         return state;
646 }
647 
648 void
649 nfs4_state_set_mode_locked(struct nfs4_state *state, fmode_t fmode)
650 {
651         if (state->state == fmode)
652                 return;
653         /* NB! List reordering - see the reclaim code for why.  */
654         if ((fmode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
655                 if (fmode & FMODE_WRITE)
656                         list_move(&state->open_states, &state->owner->so_states);
657                 else
658                         list_move_tail(&state->open_states, &state->owner->so_states);
659         }
660         state->state = fmode;
661 }
662 
663 static struct nfs4_state *
664 __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
665 {
666         struct nfs_inode *nfsi = NFS_I(inode);
667         struct nfs4_state *state;
668 
669         list_for_each_entry(state, &nfsi->open_states, inode_states) {
670                 if (state->owner != owner)
671                         continue;
672                 if (!nfs4_valid_open_stateid(state))
673                         continue;
674                 if (atomic_inc_not_zero(&state->count))
675                         return state;
676         }
677         return NULL;
678 }
679 
680 static void
681 nfs4_free_open_state(struct nfs4_state *state)
682 {
683         kfree(state);
684 }
685 
686 struct nfs4_state *
687 nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
688 {
689         struct nfs4_state *state, *new;
690         struct nfs_inode *nfsi = NFS_I(inode);
691 
692         spin_lock(&inode->i_lock);
693         state = __nfs4_find_state_byowner(inode, owner);
694         spin_unlock(&inode->i_lock);
695         if (state)
696                 goto out;
697         new = nfs4_alloc_open_state();
698         spin_lock(&owner->so_lock);
699         spin_lock(&inode->i_lock);
700         state = __nfs4_find_state_byowner(inode, owner);
701         if (state == NULL && new != NULL) {
702                 state = new;
703                 state->owner = owner;
704                 atomic_inc(&owner->so_count);
705                 list_add(&state->inode_states, &nfsi->open_states);
706                 ihold(inode);
707                 state->inode = inode;
708                 spin_unlock(&inode->i_lock);
709                 /* Note: The reclaim code dictates that we add stateless
710                  * and read-only stateids to the end of the list */
711                 list_add_tail(&state->open_states, &owner->so_states);
712                 spin_unlock(&owner->so_lock);
713         } else {
714                 spin_unlock(&inode->i_lock);
715                 spin_unlock(&owner->so_lock);
716                 if (new)
717                         nfs4_free_open_state(new);
718         }
719 out:
720         return state;
721 }
722 
723 void nfs4_put_open_state(struct nfs4_state *state)
724 {
725         struct inode *inode = state->inode;
726         struct nfs4_state_owner *owner = state->owner;
727 
728         if (!atomic_dec_and_lock(&state->count, &owner->so_lock))
729                 return;
730         spin_lock(&inode->i_lock);
731         list_del(&state->inode_states);
732         list_del(&state->open_states);
733         spin_unlock(&inode->i_lock);
734         spin_unlock(&owner->so_lock);
735         iput(inode);
736         nfs4_free_open_state(state);
737         nfs4_put_state_owner(owner);
738 }
739 
740 /*
741  * Close the current file.
742  */
743 static void __nfs4_close(struct nfs4_state *state,
744                 fmode_t fmode, gfp_t gfp_mask, int wait)
745 {
746         struct nfs4_state_owner *owner = state->owner;
747         int call_close = 0;
748         fmode_t newstate;
749 
750         atomic_inc(&owner->so_count);
751         /* Protect against nfs4_find_state() */
752         spin_lock(&owner->so_lock);
753         switch (fmode & (FMODE_READ | FMODE_WRITE)) {
754                 case FMODE_READ:
755                         state->n_rdonly--;
756                         break;
757                 case FMODE_WRITE:
758                         state->n_wronly--;
759                         break;
760                 case FMODE_READ|FMODE_WRITE:
761                         state->n_rdwr--;
762         }
763         newstate = FMODE_READ|FMODE_WRITE;
764         if (state->n_rdwr == 0) {
765                 if (state->n_rdonly == 0) {
766                         newstate &= ~FMODE_READ;
767                         call_close |= test_bit(NFS_O_RDONLY_STATE, &state->flags);
768                         call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
769                 }
770                 if (state->n_wronly == 0) {
771                         newstate &= ~FMODE_WRITE;
772                         call_close |= test_bit(NFS_O_WRONLY_STATE, &state->flags);
773                         call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
774                 }
775                 if (newstate == 0)
776                         clear_bit(NFS_DELEGATED_STATE, &state->flags);
777         }
778         nfs4_state_set_mode_locked(state, newstate);
779         spin_unlock(&owner->so_lock);
780 
781         if (!call_close) {
782                 nfs4_put_open_state(state);
783                 nfs4_put_state_owner(owner);
784         } else
785                 nfs4_do_close(state, gfp_mask, wait);
786 }
787 
788 void nfs4_close_state(struct nfs4_state *state, fmode_t fmode)
789 {
790         __nfs4_close(state, fmode, GFP_NOFS, 0);
791 }
792 
793 void nfs4_close_sync(struct nfs4_state *state, fmode_t fmode)
794 {
795         __nfs4_close(state, fmode, GFP_KERNEL, 1);
796 }
797 
798 /*
799  * Search the state->lock_states for an existing lock_owner
800  * that is compatible with current->files
801  */
802 static struct nfs4_lock_state *
803 __nfs4_find_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
804 {
805         struct nfs4_lock_state *pos;
806         list_for_each_entry(pos, &state->lock_states, ls_locks) {
807                 if (pos->ls_owner != fl_owner)
808                         continue;
809                 atomic_inc(&pos->ls_count);
810                 return pos;
811         }
812         return NULL;
813 }
814 
815 /*
816  * Return a compatible lock_state. If no initialized lock_state structure
817  * exists, return an uninitialized one.
818  *
819  */
820 static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
821 {
822         struct nfs4_lock_state *lsp;
823         struct nfs_server *server = state->owner->so_server;
824 
825         lsp = kzalloc(sizeof(*lsp), GFP_NOFS);
826         if (lsp == NULL)
827                 return NULL;
828         nfs4_init_seqid_counter(&lsp->ls_seqid);
829         atomic_set(&lsp->ls_count, 1);
830         lsp->ls_state = state;
831         lsp->ls_owner = fl_owner;
832         lsp->ls_seqid.owner_id = ida_simple_get(&server->lockowner_id, 0, 0, GFP_NOFS);
833         if (lsp->ls_seqid.owner_id < 0)
834                 goto out_free;
835         INIT_LIST_HEAD(&lsp->ls_locks);
836         return lsp;
837 out_free:
838         kfree(lsp);
839         return NULL;
840 }
841 
842 void nfs4_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp)
843 {
844         ida_simple_remove(&server->lockowner_id, lsp->ls_seqid.owner_id);
845         nfs4_destroy_seqid_counter(&lsp->ls_seqid);
846         kfree(lsp);
847 }
848 
849 /*
850  * Return a compatible lock_state. If no initialized lock_state structure
851  * exists, return an uninitialized one.
852  *
853  */
854 static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
855 {
856         struct nfs4_lock_state *lsp, *new = NULL;
857         
858         for(;;) {
859                 spin_lock(&state->state_lock);
860                 lsp = __nfs4_find_lock_state(state, owner);
861                 if (lsp != NULL)
862                         break;
863                 if (new != NULL) {
864                         list_add(&new->ls_locks, &state->lock_states);
865                         set_bit(LK_STATE_IN_USE, &state->flags);
866                         lsp = new;
867                         new = NULL;
868                         break;
869                 }
870                 spin_unlock(&state->state_lock);
871                 new = nfs4_alloc_lock_state(state, owner);
872                 if (new == NULL)
873                         return NULL;
874         }
875         spin_unlock(&state->state_lock);
876         if (new != NULL)
877                 nfs4_free_lock_state(state->owner->so_server, new);
878         return lsp;
879 }
880 
881 /*
882  * Release reference to lock_state, and free it if we see that
883  * it is no longer in use
884  */
885 void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
886 {
887         struct nfs_server *server;
888         struct nfs4_state *state;
889 
890         if (lsp == NULL)
891                 return;
892         state = lsp->ls_state;
893         if (!atomic_dec_and_lock(&lsp->ls_count, &state->state_lock))
894                 return;
895         list_del(&lsp->ls_locks);
896         if (list_empty(&state->lock_states))
897                 clear_bit(LK_STATE_IN_USE, &state->flags);
898         spin_unlock(&state->state_lock);
899         server = state->owner->so_server;
900         if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags)) {
901                 struct nfs_client *clp = server->nfs_client;
902 
903                 clp->cl_mvops->free_lock_state(server, lsp);
904         } else
905                 nfs4_free_lock_state(server, lsp);
906 }
907 
908 static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
909 {
910         struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
911 
912         dst->fl_u.nfs4_fl.owner = lsp;
913         atomic_inc(&lsp->ls_count);
914 }
915 
916 static void nfs4_fl_release_lock(struct file_lock *fl)
917 {
918         nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
919 }
920 
921 static const struct file_lock_operations nfs4_fl_lock_ops = {
922         .fl_copy_lock = nfs4_fl_copy_lock,
923         .fl_release_private = nfs4_fl_release_lock,
924 };
925 
926 int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
927 {
928         struct nfs4_lock_state *lsp;
929 
930         if (fl->fl_ops != NULL)
931                 return 0;
932         lsp = nfs4_get_lock_state(state, fl->fl_owner);
933         if (lsp == NULL)
934                 return -ENOMEM;
935         fl->fl_u.nfs4_fl.owner = lsp;
936         fl->fl_ops = &nfs4_fl_lock_ops;
937         return 0;
938 }
939 
940 static int nfs4_copy_lock_stateid(nfs4_stateid *dst,
941                 struct nfs4_state *state,
942                 const struct nfs_lockowner *lockowner)
943 {
944         struct nfs4_lock_state *lsp;
945         fl_owner_t fl_owner;
946         int ret = -ENOENT;
947 
948 
949         if (lockowner == NULL)
950                 goto out;
951 
952         if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
953                 goto out;
954 
955         fl_owner = lockowner->l_owner;
956         spin_lock(&state->state_lock);
957         lsp = __nfs4_find_lock_state(state, fl_owner);
958         if (lsp && test_bit(NFS_LOCK_LOST, &lsp->ls_flags))
959                 ret = -EIO;
960         else if (lsp != NULL && test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags) != 0) {
961                 nfs4_stateid_copy(dst, &lsp->ls_stateid);
962                 ret = 0;
963         }
964         spin_unlock(&state->state_lock);
965         nfs4_put_lock_state(lsp);
966 out:
967         return ret;
968 }
969 
970 static void nfs4_copy_open_stateid(nfs4_stateid *dst, struct nfs4_state *state)
971 {
972         const nfs4_stateid *src;
973         int seq;
974 
975         do {
976                 src = &zero_stateid;
977                 seq = read_seqbegin(&state->seqlock);
978                 if (test_bit(NFS_OPEN_STATE, &state->flags))
979                         src = &state->open_stateid;
980                 nfs4_stateid_copy(dst, src);
981         } while (read_seqretry(&state->seqlock, seq));
982 }
983 
984 /*
985  * Byte-range lock aware utility to initialize the stateid of read/write
986  * requests.
987  */
988 int nfs4_select_rw_stateid(nfs4_stateid *dst, struct nfs4_state *state,
989                 fmode_t fmode, const struct nfs_lockowner *lockowner)
990 {
991         int ret = nfs4_copy_lock_stateid(dst, state, lockowner);
992         if (ret == -EIO)
993                 /* A lost lock - don't even consider delegations */
994                 goto out;
995         /* returns true if delegation stateid found and copied */
996         if (nfs4_copy_delegation_stateid(dst, state->inode, fmode)) {
997                 ret = 0;
998                 goto out;
999         }
1000         if (ret != -ENOENT)
1001                 /* nfs4_copy_delegation_stateid() didn't over-write
1002                  * dst, so it still has the lock stateid which we now
1003                  * choose to use.
1004                  */
1005                 goto out;
1006         nfs4_copy_open_stateid(dst, state);
1007         ret = 0;
1008 out:
1009         if (nfs_server_capable(state->inode, NFS_CAP_STATEID_NFSV41))
1010                 dst->seqid = 0;
1011         return ret;
1012 }
1013 
1014 struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask)
1015 {
1016         struct nfs_seqid *new;
1017 
1018         new = kmalloc(sizeof(*new), gfp_mask);
1019         if (new == NULL)
1020                 return ERR_PTR(-ENOMEM);
1021         new->sequence = counter;
1022         INIT_LIST_HEAD(&new->list);
1023         new->task = NULL;
1024         return new;
1025 }
1026 
1027 void nfs_release_seqid(struct nfs_seqid *seqid)
1028 {
1029         struct nfs_seqid_counter *sequence;
1030 
1031         if (seqid == NULL || list_empty(&seqid->list))
1032                 return;
1033         sequence = seqid->sequence;
1034         spin_lock(&sequence->lock);
1035         list_del_init(&seqid->list);
1036         if (!list_empty(&sequence->list)) {
1037                 struct nfs_seqid *next;
1038 
1039                 next = list_first_entry(&sequence->list,
1040                                 struct nfs_seqid, list);
1041                 rpc_wake_up_queued_task(&sequence->wait, next->task);
1042         }
1043         spin_unlock(&sequence->lock);
1044 }
1045 
1046 void nfs_free_seqid(struct nfs_seqid *seqid)
1047 {
1048         nfs_release_seqid(seqid);
1049         kfree(seqid);
1050 }
1051 
1052 /*
1053  * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
1054  * failed with a seqid incrementing error -
1055  * see comments nfs4.h:seqid_mutating_error()
1056  */
1057 static void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
1058 {
1059         switch (status) {
1060                 case 0:
1061                         break;
1062                 case -NFS4ERR_BAD_SEQID:
1063                         if (seqid->sequence->flags & NFS_SEQID_CONFIRMED)
1064                                 return;
1065                         pr_warn_ratelimited("NFS: v4 server returned a bad"
1066                                         " sequence-id error on an"
1067                                         " unconfirmed sequence %p!\n",
1068                                         seqid->sequence);
1069                 case -NFS4ERR_STALE_CLIENTID:
1070                 case -NFS4ERR_STALE_STATEID:
1071                 case -NFS4ERR_BAD_STATEID:
1072                 case -NFS4ERR_BADXDR:
1073                 case -NFS4ERR_RESOURCE:
1074                 case -NFS4ERR_NOFILEHANDLE:
1075                         /* Non-seqid mutating errors */
1076                         return;
1077         };
1078         /*
1079          * Note: no locking needed as we are guaranteed to be first
1080          * on the sequence list
1081          */
1082         seqid->sequence->counter++;
1083 }
1084 
1085 void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
1086 {
1087         struct nfs4_state_owner *sp;
1088 
1089         if (seqid == NULL)
1090                 return;
1091 
1092         sp = container_of(seqid->sequence, struct nfs4_state_owner, so_seqid);
1093         if (status == -NFS4ERR_BAD_SEQID)
1094                 nfs4_drop_state_owner(sp);
1095         if (!nfs4_has_session(sp->so_server->nfs_client))
1096                 nfs_increment_seqid(status, seqid);
1097 }
1098 
1099 /*
1100  * Increment the seqid if the LOCK/LOCKU succeeded, or
1101  * failed with a seqid incrementing error -
1102  * see comments nfs4.h:seqid_mutating_error()
1103  */
1104 void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
1105 {
1106         if (seqid != NULL)
1107                 nfs_increment_seqid(status, seqid);
1108 }
1109 
1110 int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
1111 {
1112         struct nfs_seqid_counter *sequence;
1113         int status = 0;
1114 
1115         if (seqid == NULL)
1116                 goto out;
1117         sequence = seqid->sequence;
1118         spin_lock(&sequence->lock);
1119         seqid->task = task;
1120         if (list_empty(&seqid->list))
1121                 list_add_tail(&seqid->list, &sequence->list);
1122         if (list_first_entry(&sequence->list, struct nfs_seqid, list) == seqid)
1123                 goto unlock;
1124         rpc_sleep_on(&sequence->wait, task, NULL);
1125         status = -EAGAIN;
1126 unlock:
1127         spin_unlock(&sequence->lock);
1128 out:
1129         return status;
1130 }
1131 
1132 static int nfs4_run_state_manager(void *);
1133 
1134 static void nfs4_clear_state_manager_bit(struct nfs_client *clp)
1135 {
1136         smp_mb__before_atomic();
1137         clear_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state);
1138         smp_mb__after_atomic();
1139         wake_up_bit(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING);
1140         rpc_wake_up(&clp->cl_rpcwaitq);
1141 }
1142 
1143 /*
1144  * Schedule the nfs_client asynchronous state management routine
1145  */
1146 void nfs4_schedule_state_manager(struct nfs_client *clp)
1147 {
1148         struct task_struct *task;
1149         char buf[INET6_ADDRSTRLEN + sizeof("-manager") + 1];
1150 
1151         if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
1152                 return;
1153         __module_get(THIS_MODULE);
1154         atomic_inc(&clp->cl_count);
1155 
1156         /* The rcu_read_lock() is not strictly necessary, as the state
1157          * manager is the only thread that ever changes the rpc_xprt
1158          * after it's initialized.  At this point, we're single threaded. */
1159         rcu_read_lock();
1160         snprintf(buf, sizeof(buf), "%s-manager",
1161                         rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
1162         rcu_read_unlock();
1163         task = kthread_run(nfs4_run_state_manager, clp, "%s", buf);
1164         if (IS_ERR(task)) {
1165                 printk(KERN_ERR "%s: kthread_run: %ld\n",
1166                         __func__, PTR_ERR(task));
1167                 nfs4_clear_state_manager_bit(clp);
1168                 nfs_put_client(clp);
1169                 module_put(THIS_MODULE);
1170         }
1171 }
1172 
1173 /*
1174  * Schedule a lease recovery attempt
1175  */
1176 void nfs4_schedule_lease_recovery(struct nfs_client *clp)
1177 {
1178         if (!clp)
1179                 return;
1180         if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1181                 set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1182         dprintk("%s: scheduling lease recovery for server %s\n", __func__,
1183                         clp->cl_hostname);
1184         nfs4_schedule_state_manager(clp);
1185 }
1186 EXPORT_SYMBOL_GPL(nfs4_schedule_lease_recovery);
1187 
1188 /**
1189  * nfs4_schedule_migration_recovery - trigger migration recovery
1190  *
1191  * @server: FSID that is migrating
1192  *
1193  * Returns zero if recovery has started, otherwise a negative NFS4ERR
1194  * value is returned.
1195  */
1196 int nfs4_schedule_migration_recovery(const struct nfs_server *server)
1197 {
1198         struct nfs_client *clp = server->nfs_client;
1199 
1200         if (server->fh_expire_type != NFS4_FH_PERSISTENT) {
1201                 pr_err("NFS: volatile file handles not supported (server %s)\n",
1202                                 clp->cl_hostname);
1203                 return -NFS4ERR_IO;
1204         }
1205 
1206         if (test_bit(NFS_MIG_FAILED, &server->mig_status))
1207                 return -NFS4ERR_IO;
1208 
1209         dprintk("%s: scheduling migration recovery for (%llx:%llx) on %s\n",
1210                         __func__,
1211                         (unsigned long long)server->fsid.major,
1212                         (unsigned long long)server->fsid.minor,
1213                         clp->cl_hostname);
1214 
1215         set_bit(NFS_MIG_IN_TRANSITION,
1216                         &((struct nfs_server *)server)->mig_status);
1217         set_bit(NFS4CLNT_MOVED, &clp->cl_state);
1218 
1219         nfs4_schedule_state_manager(clp);
1220         return 0;
1221 }
1222 EXPORT_SYMBOL_GPL(nfs4_schedule_migration_recovery);
1223 
1224 /**
1225  * nfs4_schedule_lease_moved_recovery - start lease-moved recovery
1226  *
1227  * @clp: server to check for moved leases
1228  *
1229  */
1230 void nfs4_schedule_lease_moved_recovery(struct nfs_client *clp)
1231 {
1232         dprintk("%s: scheduling lease-moved recovery for client ID %llx on %s\n",
1233                 __func__, clp->cl_clientid, clp->cl_hostname);
1234 
1235         set_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state);
1236         nfs4_schedule_state_manager(clp);
1237 }
1238 EXPORT_SYMBOL_GPL(nfs4_schedule_lease_moved_recovery);
1239 
1240 int nfs4_wait_clnt_recover(struct nfs_client *clp)
1241 {
1242         int res;
1243 
1244         might_sleep();
1245 
1246         atomic_inc(&clp->cl_count);
1247         res = wait_on_bit_action(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING,
1248                                  nfs_wait_bit_killable, TASK_KILLABLE);
1249         if (res)
1250                 goto out;
1251         if (clp->cl_cons_state < 0)
1252                 res = clp->cl_cons_state;
1253 out:
1254         nfs_put_client(clp);
1255         return res;
1256 }
1257 
1258 int nfs4_client_recover_expired_lease(struct nfs_client *clp)
1259 {
1260         unsigned int loop;
1261         int ret;
1262 
1263         for (loop = NFS4_MAX_LOOP_ON_RECOVER; loop != 0; loop--) {
1264                 ret = nfs4_wait_clnt_recover(clp);
1265                 if (ret != 0)
1266                         break;
1267                 if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) &&
1268                     !test_bit(NFS4CLNT_CHECK_LEASE,&clp->cl_state))
1269                         break;
1270                 nfs4_schedule_state_manager(clp);
1271                 ret = -EIO;
1272         }
1273         return ret;
1274 }
1275 
1276 /*
1277  * nfs40_handle_cb_pathdown - return all delegations after NFS4ERR_CB_PATH_DOWN
1278  * @clp: client to process
1279  *
1280  * Set the NFS4CLNT_LEASE_EXPIRED state in order to force a
1281  * resend of the SETCLIENTID and hence re-establish the
1282  * callback channel. Then return all existing delegations.
1283  */
1284 static void nfs40_handle_cb_pathdown(struct nfs_client *clp)
1285 {
1286         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1287         nfs_expire_all_delegations(clp);
1288         dprintk("%s: handling CB_PATHDOWN recovery for server %s\n", __func__,
1289                         clp->cl_hostname);
1290 }
1291 
1292 void nfs4_schedule_path_down_recovery(struct nfs_client *clp)
1293 {
1294         nfs40_handle_cb_pathdown(clp);
1295         nfs4_schedule_state_manager(clp);
1296 }
1297 
1298 static int nfs4_state_mark_reclaim_reboot(struct nfs_client *clp, struct nfs4_state *state)
1299 {
1300 
1301         set_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1302         /* Don't recover state that expired before the reboot */
1303         if (test_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags)) {
1304                 clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1305                 return 0;
1306         }
1307         set_bit(NFS_OWNER_RECLAIM_REBOOT, &state->owner->so_flags);
1308         set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1309         return 1;
1310 }
1311 
1312 int nfs4_state_mark_reclaim_nograce(struct nfs_client *clp, struct nfs4_state *state)
1313 {
1314         set_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
1315         clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1316         set_bit(NFS_OWNER_RECLAIM_NOGRACE, &state->owner->so_flags);
1317         set_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
1318         return 1;
1319 }
1320 
1321 int nfs4_schedule_stateid_recovery(const struct nfs_server *server, struct nfs4_state *state)
1322 {
1323         struct nfs_client *clp = server->nfs_client;
1324 
1325         if (!nfs4_valid_open_stateid(state))
1326                 return -EBADF;
1327         nfs4_state_mark_reclaim_nograce(clp, state);
1328         dprintk("%s: scheduling stateid recovery for server %s\n", __func__,
1329                         clp->cl_hostname);
1330         nfs4_schedule_state_manager(clp);
1331         return 0;
1332 }
1333 EXPORT_SYMBOL_GPL(nfs4_schedule_stateid_recovery);
1334 
1335 void nfs_inode_find_state_and_recover(struct inode *inode,
1336                 const nfs4_stateid *stateid)
1337 {
1338         struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
1339         struct nfs_inode *nfsi = NFS_I(inode);
1340         struct nfs_open_context *ctx;
1341         struct nfs4_state *state;
1342         bool found = false;
1343 
1344         spin_lock(&inode->i_lock);
1345         list_for_each_entry(ctx, &nfsi->open_files, list) {
1346                 state = ctx->state;
1347                 if (state == NULL)
1348                         continue;
1349                 if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
1350                         continue;
1351                 if (!nfs4_stateid_match(&state->stateid, stateid))
1352                         continue;
1353                 nfs4_state_mark_reclaim_nograce(clp, state);
1354                 found = true;
1355         }
1356         spin_unlock(&inode->i_lock);
1357         if (found)
1358                 nfs4_schedule_state_manager(clp);
1359 }
1360 
1361 static void nfs4_state_mark_open_context_bad(struct nfs4_state *state)
1362 {
1363         struct inode *inode = state->inode;
1364         struct nfs_inode *nfsi = NFS_I(inode);
1365         struct nfs_open_context *ctx;
1366 
1367         spin_lock(&inode->i_lock);
1368         list_for_each_entry(ctx, &nfsi->open_files, list) {
1369                 if (ctx->state != state)
1370                         continue;
1371                 set_bit(NFS_CONTEXT_BAD, &ctx->flags);
1372         }
1373         spin_unlock(&inode->i_lock);
1374 }
1375 
1376 static void nfs4_state_mark_recovery_failed(struct nfs4_state *state, int error)
1377 {
1378         set_bit(NFS_STATE_RECOVERY_FAILED, &state->flags);
1379         nfs4_state_mark_open_context_bad(state);
1380 }
1381 
1382 
1383 static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_recovery_ops *ops)
1384 {
1385         struct inode *inode = state->inode;
1386         struct nfs_inode *nfsi = NFS_I(inode);
1387         struct file_lock *fl;
1388         int status = 0;
1389         struct file_lock_context *flctx = inode->i_flctx;
1390         struct list_head *list;
1391 
1392         if (flctx == NULL)
1393                 return 0;
1394 
1395         list = &flctx->flc_posix;
1396 
1397         /* Guard against delegation returns and new lock/unlock calls */
1398         down_write(&nfsi->rwsem);
1399         spin_lock(&flctx->flc_lock);
1400 restart:
1401         list_for_each_entry(fl, list, fl_list) {
1402                 if (nfs_file_open_context(fl->fl_file)->state != state)
1403                         continue;
1404                 spin_unlock(&flctx->flc_lock);
1405                 status = ops->recover_lock(state, fl);
1406                 switch (status) {
1407                 case 0:
1408                         break;
1409                 case -ESTALE:
1410                 case -NFS4ERR_ADMIN_REVOKED:
1411                 case -NFS4ERR_STALE_STATEID:
1412                 case -NFS4ERR_BAD_STATEID:
1413                 case -NFS4ERR_EXPIRED:
1414                 case -NFS4ERR_NO_GRACE:
1415                 case -NFS4ERR_STALE_CLIENTID:
1416                 case -NFS4ERR_BADSESSION:
1417                 case -NFS4ERR_BADSLOT:
1418                 case -NFS4ERR_BAD_HIGH_SLOT:
1419                 case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1420                         goto out;
1421                 default:
1422                         pr_err("NFS: %s: unhandled error %d\n",
1423                                         __func__, status);
1424                 case -ENOMEM:
1425                 case -NFS4ERR_DENIED:
1426                 case -NFS4ERR_RECLAIM_BAD:
1427                 case -NFS4ERR_RECLAIM_CONFLICT:
1428                         /* kill_proc(fl->fl_pid, SIGLOST, 1); */
1429                         status = 0;
1430                 }
1431                 spin_lock(&flctx->flc_lock);
1432         }
1433         if (list == &flctx->flc_posix) {
1434                 list = &flctx->flc_flock;
1435                 goto restart;
1436         }
1437         spin_unlock(&flctx->flc_lock);
1438 out:
1439         up_write(&nfsi->rwsem);
1440         return status;
1441 }
1442 
1443 static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp, const struct nfs4_state_recovery_ops *ops)
1444 {
1445         struct nfs4_state *state;
1446         struct nfs4_lock_state *lock;
1447         int status = 0;
1448 
1449         /* Note: we rely on the sp->so_states list being ordered 
1450          * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
1451          * states first.
1452          * This is needed to ensure that the server won't give us any
1453          * read delegations that we have to return if, say, we are
1454          * recovering after a network partition or a reboot from a
1455          * server that doesn't support a grace period.
1456          */
1457         spin_lock(&sp->so_lock);
1458         raw_write_seqcount_begin(&sp->so_reclaim_seqcount);
1459 restart:
1460         list_for_each_entry(state, &sp->so_states, open_states) {
1461                 if (!test_and_clear_bit(ops->state_flag_bit, &state->flags))
1462                         continue;
1463                 if (!nfs4_valid_open_stateid(state))
1464                         continue;
1465                 if (state->state == 0)
1466                         continue;
1467                 atomic_inc(&state->count);
1468                 spin_unlock(&sp->so_lock);
1469                 status = ops->recover_open(sp, state);
1470                 if (status >= 0) {
1471                         status = nfs4_reclaim_locks(state, ops);
1472                         if (status >= 0) {
1473                                 if (!test_bit(NFS_DELEGATED_STATE, &state->flags)) {
1474                                         spin_lock(&state->state_lock);
1475                                         list_for_each_entry(lock, &state->lock_states, ls_locks) {
1476                                                 if (!test_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags))
1477                                                         pr_warn_ratelimited("NFS: "
1478                                                                             "%s: Lock reclaim "
1479                                                                             "failed!\n", __func__);
1480                                         }
1481                                         spin_unlock(&state->state_lock);
1482                                 }
1483                                 nfs4_put_open_state(state);
1484                                 clear_bit(NFS_STATE_RECLAIM_NOGRACE,
1485                                         &state->flags);
1486                                 spin_lock(&sp->so_lock);
1487                                 goto restart;
1488                         }
1489                 }
1490                 switch (status) {
1491                         default:
1492                                 printk(KERN_ERR "NFS: %s: unhandled error %d\n",
1493                                         __func__, status);
1494                         case -ENOENT:
1495                         case -ENOMEM:
1496                         case -ESTALE:
1497                                 /* Open state on this file cannot be recovered */
1498                                 nfs4_state_mark_recovery_failed(state, status);
1499                                 break;
1500                         case -EAGAIN:
1501                                 ssleep(1);
1502                         case -NFS4ERR_ADMIN_REVOKED:
1503                         case -NFS4ERR_STALE_STATEID:
1504                         case -NFS4ERR_BAD_STATEID:
1505                         case -NFS4ERR_RECLAIM_BAD:
1506                         case -NFS4ERR_RECLAIM_CONFLICT:
1507                                 nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1508                                 break;
1509                         case -NFS4ERR_EXPIRED:
1510                         case -NFS4ERR_NO_GRACE:
1511                                 nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1512                         case -NFS4ERR_STALE_CLIENTID:
1513                         case -NFS4ERR_BADSESSION:
1514                         case -NFS4ERR_BADSLOT:
1515                         case -NFS4ERR_BAD_HIGH_SLOT:
1516                         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1517                                 goto out_err;
1518                 }
1519                 nfs4_put_open_state(state);
1520                 spin_lock(&sp->so_lock);
1521                 goto restart;
1522         }
1523         raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1524         spin_unlock(&sp->so_lock);
1525         return 0;
1526 out_err:
1527         nfs4_put_open_state(state);
1528         spin_lock(&sp->so_lock);
1529         raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1530         spin_unlock(&sp->so_lock);
1531         return status;
1532 }
1533 
1534 static void nfs4_clear_open_state(struct nfs4_state *state)
1535 {
1536         struct nfs4_lock_state *lock;
1537 
1538         clear_bit(NFS_DELEGATED_STATE, &state->flags);
1539         clear_bit(NFS_O_RDONLY_STATE, &state->flags);
1540         clear_bit(NFS_O_WRONLY_STATE, &state->flags);
1541         clear_bit(NFS_O_RDWR_STATE, &state->flags);
1542         spin_lock(&state->state_lock);
1543         list_for_each_entry(lock, &state->lock_states, ls_locks) {
1544                 lock->ls_seqid.flags = 0;
1545                 clear_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags);
1546         }
1547         spin_unlock(&state->state_lock);
1548 }
1549 
1550 static void nfs4_reset_seqids(struct nfs_server *server,
1551         int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1552 {
1553         struct nfs_client *clp = server->nfs_client;
1554         struct nfs4_state_owner *sp;
1555         struct rb_node *pos;
1556         struct nfs4_state *state;
1557 
1558         spin_lock(&clp->cl_lock);
1559         for (pos = rb_first(&server->state_owners);
1560              pos != NULL;
1561              pos = rb_next(pos)) {
1562                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1563                 sp->so_seqid.flags = 0;
1564                 spin_lock(&sp->so_lock);
1565                 list_for_each_entry(state, &sp->so_states, open_states) {
1566                         if (mark_reclaim(clp, state))
1567                                 nfs4_clear_open_state(state);
1568                 }
1569                 spin_unlock(&sp->so_lock);
1570         }
1571         spin_unlock(&clp->cl_lock);
1572 }
1573 
1574 static void nfs4_state_mark_reclaim_helper(struct nfs_client *clp,
1575         int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1576 {
1577         struct nfs_server *server;
1578 
1579         rcu_read_lock();
1580         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1581                 nfs4_reset_seqids(server, mark_reclaim);
1582         rcu_read_unlock();
1583 }
1584 
1585 static void nfs4_state_start_reclaim_reboot(struct nfs_client *clp)
1586 {
1587         /* Mark all delegations for reclaim */
1588         nfs_delegation_mark_reclaim(clp);
1589         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_reboot);
1590 }
1591 
1592 static void nfs4_reclaim_complete(struct nfs_client *clp,
1593                                  const struct nfs4_state_recovery_ops *ops,
1594                                  struct rpc_cred *cred)
1595 {
1596         /* Notify the server we're done reclaiming our state */
1597         if (ops->reclaim_complete)
1598                 (void)ops->reclaim_complete(clp, cred);
1599 }
1600 
1601 static void nfs4_clear_reclaim_server(struct nfs_server *server)
1602 {
1603         struct nfs_client *clp = server->nfs_client;
1604         struct nfs4_state_owner *sp;
1605         struct rb_node *pos;
1606         struct nfs4_state *state;
1607 
1608         spin_lock(&clp->cl_lock);
1609         for (pos = rb_first(&server->state_owners);
1610              pos != NULL;
1611              pos = rb_next(pos)) {
1612                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1613                 spin_lock(&sp->so_lock);
1614                 list_for_each_entry(state, &sp->so_states, open_states) {
1615                         if (!test_and_clear_bit(NFS_STATE_RECLAIM_REBOOT,
1616                                                 &state->flags))
1617                                 continue;
1618                         nfs4_state_mark_reclaim_nograce(clp, state);
1619                 }
1620                 spin_unlock(&sp->so_lock);
1621         }
1622         spin_unlock(&clp->cl_lock);
1623 }
1624 
1625 static int nfs4_state_clear_reclaim_reboot(struct nfs_client *clp)
1626 {
1627         struct nfs_server *server;
1628 
1629         if (!test_and_clear_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
1630                 return 0;
1631 
1632         rcu_read_lock();
1633         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1634                 nfs4_clear_reclaim_server(server);
1635         rcu_read_unlock();
1636 
1637         nfs_delegation_reap_unclaimed(clp);
1638         return 1;
1639 }
1640 
1641 static void nfs4_state_end_reclaim_reboot(struct nfs_client *clp)
1642 {
1643         const struct nfs4_state_recovery_ops *ops;
1644         struct rpc_cred *cred;
1645 
1646         if (!nfs4_state_clear_reclaim_reboot(clp))
1647                 return;
1648         ops = clp->cl_mvops->reboot_recovery_ops;
1649         cred = nfs4_get_clid_cred(clp);
1650         nfs4_reclaim_complete(clp, ops, cred);
1651         put_rpccred(cred);
1652 }
1653 
1654 static void nfs_delegation_clear_all(struct nfs_client *clp)
1655 {
1656         nfs_delegation_mark_reclaim(clp);
1657         nfs_delegation_reap_unclaimed(clp);
1658 }
1659 
1660 static void nfs4_state_start_reclaim_nograce(struct nfs_client *clp)
1661 {
1662         nfs_delegation_clear_all(clp);
1663         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_nograce);
1664 }
1665 
1666 static int nfs4_recovery_handle_error(struct nfs_client *clp, int error)
1667 {
1668         switch (error) {
1669                 case 0:
1670                         break;
1671                 case -NFS4ERR_CB_PATH_DOWN:
1672                         nfs40_handle_cb_pathdown(clp);
1673                         break;
1674                 case -NFS4ERR_NO_GRACE:
1675                         nfs4_state_end_reclaim_reboot(clp);
1676                         break;
1677                 case -NFS4ERR_STALE_CLIENTID:
1678                         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1679                         nfs4_state_clear_reclaim_reboot(clp);
1680                         nfs4_state_start_reclaim_reboot(clp);
1681                         break;
1682                 case -NFS4ERR_EXPIRED:
1683                         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1684                         nfs4_state_start_reclaim_nograce(clp);
1685                         break;
1686                 case -NFS4ERR_BADSESSION:
1687                 case -NFS4ERR_BADSLOT:
1688                 case -NFS4ERR_BAD_HIGH_SLOT:
1689                 case -NFS4ERR_DEADSESSION:
1690                 case -NFS4ERR_SEQ_FALSE_RETRY:
1691                 case -NFS4ERR_SEQ_MISORDERED:
1692                         set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
1693                         /* Zero session reset errors */
1694                         break;
1695                 case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1696                         set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
1697                         break;
1698                 default:
1699                         dprintk("%s: failed to handle error %d for server %s\n",
1700                                         __func__, error, clp->cl_hostname);
1701                         return error;
1702         }
1703         dprintk("%s: handled error %d for server %s\n", __func__, error,
1704                         clp->cl_hostname);
1705         return 0;
1706 }
1707 
1708 static int nfs4_do_reclaim(struct nfs_client *clp, const struct nfs4_state_recovery_ops *ops)
1709 {
1710         struct nfs4_state_owner *sp;
1711         struct nfs_server *server;
1712         struct rb_node *pos;
1713         int status = 0;
1714 
1715 restart:
1716         rcu_read_lock();
1717         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
1718                 nfs4_purge_state_owners(server);
1719                 spin_lock(&clp->cl_lock);
1720                 for (pos = rb_first(&server->state_owners);
1721                      pos != NULL;
1722                      pos = rb_next(pos)) {
1723                         sp = rb_entry(pos,
1724                                 struct nfs4_state_owner, so_server_node);
1725                         if (!test_and_clear_bit(ops->owner_flag_bit,
1726                                                         &sp->so_flags))
1727                                 continue;
1728                         if (!atomic_inc_not_zero(&sp->so_count))
1729                                 continue;
1730                         spin_unlock(&clp->cl_lock);
1731                         rcu_read_unlock();
1732 
1733                         status = nfs4_reclaim_open_state(sp, ops);
1734                         if (status < 0) {
1735                                 set_bit(ops->owner_flag_bit, &sp->so_flags);
1736                                 nfs4_put_state_owner(sp);
1737                                 status = nfs4_recovery_handle_error(clp, status);
1738                                 return (status != 0) ? status : -EAGAIN;
1739                         }
1740 
1741                         nfs4_put_state_owner(sp);
1742                         goto restart;
1743                 }
1744                 spin_unlock(&clp->cl_lock);
1745         }
1746         rcu_read_unlock();
1747         return 0;
1748 }
1749 
1750 static int nfs4_check_lease(struct nfs_client *clp)
1751 {
1752         struct rpc_cred *cred;
1753         const struct nfs4_state_maintenance_ops *ops =
1754                 clp->cl_mvops->state_renewal_ops;
1755         int status;
1756 
1757         /* Is the client already known to have an expired lease? */
1758         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1759                 return 0;
1760         spin_lock(&clp->cl_lock);
1761         cred = ops->get_state_renewal_cred_locked(clp);
1762         spin_unlock(&clp->cl_lock);
1763         if (cred == NULL) {
1764                 cred = nfs4_get_clid_cred(clp);
1765                 status = -ENOKEY;
1766                 if (cred == NULL)
1767                         goto out;
1768         }
1769         status = ops->renew_lease(clp, cred);
1770         put_rpccred(cred);
1771         if (status == -ETIMEDOUT) {
1772                 set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1773                 return 0;
1774         }
1775 out:
1776         return nfs4_recovery_handle_error(clp, status);
1777 }
1778 
1779 /* Set NFS4CLNT_LEASE_EXPIRED and reclaim reboot state for all v4.0 errors
1780  * and for recoverable errors on EXCHANGE_ID for v4.1
1781  */
1782 static int nfs4_handle_reclaim_lease_error(struct nfs_client *clp, int status)
1783 {
1784         switch (status) {
1785         case -NFS4ERR_SEQ_MISORDERED:
1786                 if (test_and_set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state))
1787                         return -ESERVERFAULT;
1788                 /* Lease confirmation error: retry after purging the lease */
1789                 ssleep(1);
1790                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1791                 break;
1792         case -NFS4ERR_STALE_CLIENTID:
1793                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1794                 nfs4_state_start_reclaim_reboot(clp);
1795                 break;
1796         case -NFS4ERR_CLID_INUSE:
1797                 pr_err("NFS: Server %s reports our clientid is in use\n",
1798                         clp->cl_hostname);
1799                 nfs_mark_client_ready(clp, -EPERM);
1800                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1801                 return -EPERM;
1802         case -EACCES:
1803         case -NFS4ERR_DELAY:
1804         case -ETIMEDOUT:
1805         case -EAGAIN:
1806                 ssleep(1);
1807                 break;
1808 
1809         case -NFS4ERR_MINOR_VERS_MISMATCH:
1810                 if (clp->cl_cons_state == NFS_CS_SESSION_INITING)
1811                         nfs_mark_client_ready(clp, -EPROTONOSUPPORT);
1812                 dprintk("%s: exit with error %d for server %s\n",
1813                                 __func__, -EPROTONOSUPPORT, clp->cl_hostname);
1814                 return -EPROTONOSUPPORT;
1815         case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
1816                                  * in nfs4_exchange_id */
1817         default:
1818                 dprintk("%s: exit with error %d for server %s\n", __func__,
1819                                 status, clp->cl_hostname);
1820                 return status;
1821         }
1822         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1823         dprintk("%s: handled error %d for server %s\n", __func__, status,
1824                         clp->cl_hostname);
1825         return 0;
1826 }
1827 
1828 static int nfs4_establish_lease(struct nfs_client *clp)
1829 {
1830         struct rpc_cred *cred;
1831         const struct nfs4_state_recovery_ops *ops =
1832                 clp->cl_mvops->reboot_recovery_ops;
1833         int status;
1834 
1835         nfs4_begin_drain_session(clp);
1836         cred = nfs4_get_clid_cred(clp);
1837         if (cred == NULL)
1838                 return -ENOENT;
1839         status = ops->establish_clid(clp, cred);
1840         put_rpccred(cred);
1841         if (status != 0)
1842                 return status;
1843         pnfs_destroy_all_layouts(clp);
1844         return 0;
1845 }
1846 
1847 /*
1848  * Returns zero or a negative errno.  NFS4ERR values are converted
1849  * to local errno values.
1850  */
1851 static int nfs4_reclaim_lease(struct nfs_client *clp)
1852 {
1853         int status;
1854 
1855         status = nfs4_establish_lease(clp);
1856         if (status < 0)
1857                 return nfs4_handle_reclaim_lease_error(clp, status);
1858         if (test_and_clear_bit(NFS4CLNT_SERVER_SCOPE_MISMATCH, &clp->cl_state))
1859                 nfs4_state_start_reclaim_nograce(clp);
1860         if (!test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state))
1861                 set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1862         clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1863         clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1864         return 0;
1865 }
1866 
1867 static int nfs4_purge_lease(struct nfs_client *clp)
1868 {
1869         int status;
1870 
1871         status = nfs4_establish_lease(clp);
1872         if (status < 0)
1873                 return nfs4_handle_reclaim_lease_error(clp, status);
1874         clear_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
1875         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1876         nfs4_state_start_reclaim_nograce(clp);
1877         return 0;
1878 }
1879 
1880 /*
1881  * Try remote migration of one FSID from a source server to a
1882  * destination server.  The source server provides a list of
1883  * potential destinations.
1884  *
1885  * Returns zero or a negative NFS4ERR status code.
1886  */
1887 static int nfs4_try_migration(struct nfs_server *server, struct rpc_cred *cred)
1888 {
1889         struct nfs_client *clp = server->nfs_client;
1890         struct nfs4_fs_locations *locations = NULL;
1891         struct inode *inode;
1892         struct page *page;
1893         int status, result;
1894 
1895         dprintk("--> %s: FSID %llx:%llx on \"%s\"\n", __func__,
1896                         (unsigned long long)server->fsid.major,
1897                         (unsigned long long)server->fsid.minor,
1898                         clp->cl_hostname);
1899 
1900         result = 0;
1901         page = alloc_page(GFP_KERNEL);
1902         locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
1903         if (page == NULL || locations == NULL) {
1904                 dprintk("<-- %s: no memory\n", __func__);
1905                 goto out;
1906         }
1907 
1908         inode = d_inode(server->super->s_root);
1909         result = nfs4_proc_get_locations(inode, locations, page, cred);
1910         if (result) {
1911                 dprintk("<-- %s: failed to retrieve fs_locations: %d\n",
1912                         __func__, result);
1913                 goto out;
1914         }
1915 
1916         result = -NFS4ERR_NXIO;
1917         if (!(locations->fattr.valid & NFS_ATTR_FATTR_V4_LOCATIONS)) {
1918                 dprintk("<-- %s: No fs_locations data, migration skipped\n",
1919                         __func__);
1920                 goto out;
1921         }
1922 
1923         nfs4_begin_drain_session(clp);
1924 
1925         status = nfs4_replace_transport(server, locations);
1926         if (status != 0) {
1927                 dprintk("<-- %s: failed to replace transport: %d\n",
1928                         __func__, status);
1929                 goto out;
1930         }
1931 
1932         result = 0;
1933         dprintk("<-- %s: migration succeeded\n", __func__);
1934 
1935 out:
1936         if (page != NULL)
1937                 __free_page(page);
1938         kfree(locations);
1939         if (result) {
1940                 pr_err("NFS: migration recovery failed (server %s)\n",
1941                                 clp->cl_hostname);
1942                 set_bit(NFS_MIG_FAILED, &server->mig_status);
1943         }
1944         return result;
1945 }
1946 
1947 /*
1948  * Returns zero or a negative NFS4ERR status code.
1949  */
1950 static int nfs4_handle_migration(struct nfs_client *clp)
1951 {
1952         const struct nfs4_state_maintenance_ops *ops =
1953                                 clp->cl_mvops->state_renewal_ops;
1954         struct nfs_server *server;
1955         struct rpc_cred *cred;
1956 
1957         dprintk("%s: migration reported on \"%s\"\n", __func__,
1958                         clp->cl_hostname);
1959 
1960         spin_lock(&clp->cl_lock);
1961         cred = ops->get_state_renewal_cred_locked(clp);
1962         spin_unlock(&clp->cl_lock);
1963         if (cred == NULL)
1964                 return -NFS4ERR_NOENT;
1965 
1966         clp->cl_mig_gen++;
1967 restart:
1968         rcu_read_lock();
1969         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
1970                 int status;
1971 
1972                 if (server->mig_gen == clp->cl_mig_gen)
1973                         continue;
1974                 server->mig_gen = clp->cl_mig_gen;
1975 
1976                 if (!test_and_clear_bit(NFS_MIG_IN_TRANSITION,
1977                                                 &server->mig_status))
1978                         continue;
1979 
1980                 rcu_read_unlock();
1981                 status = nfs4_try_migration(server, cred);
1982                 if (status < 0) {
1983                         put_rpccred(cred);
1984                         return status;
1985                 }
1986                 goto restart;
1987         }
1988         rcu_read_unlock();
1989         put_rpccred(cred);
1990         return 0;
1991 }
1992 
1993 /*
1994  * Test each nfs_server on the clp's cl_superblocks list to see
1995  * if it's moved to another server.  Stop when the server no longer
1996  * returns NFS4ERR_LEASE_MOVED.
1997  */
1998 static int nfs4_handle_lease_moved(struct nfs_client *clp)
1999 {
2000         const struct nfs4_state_maintenance_ops *ops =
2001                                 clp->cl_mvops->state_renewal_ops;
2002         struct nfs_server *server;
2003         struct rpc_cred *cred;
2004 
2005         dprintk("%s: lease moved reported on \"%s\"\n", __func__,
2006                         clp->cl_hostname);
2007 
2008         spin_lock(&clp->cl_lock);
2009         cred = ops->get_state_renewal_cred_locked(clp);
2010         spin_unlock(&clp->cl_lock);
2011         if (cred == NULL)
2012                 return -NFS4ERR_NOENT;
2013 
2014         clp->cl_mig_gen++;
2015 restart:
2016         rcu_read_lock();
2017         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
2018                 struct inode *inode;
2019                 int status;
2020 
2021                 if (server->mig_gen == clp->cl_mig_gen)
2022                         continue;
2023                 server->mig_gen = clp->cl_mig_gen;
2024 
2025                 rcu_read_unlock();
2026 
2027                 inode = d_inode(server->super->s_root);
2028                 status = nfs4_proc_fsid_present(inode, cred);
2029                 if (status != -NFS4ERR_MOVED)
2030                         goto restart;   /* wasn't this one */
2031                 if (nfs4_try_migration(server, cred) == -NFS4ERR_LEASE_MOVED)
2032                         goto restart;   /* there are more */
2033                 goto out;
2034         }
2035         rcu_read_unlock();
2036 
2037 out:
2038         put_rpccred(cred);
2039         return 0;
2040 }
2041 
2042 /**
2043  * nfs4_discover_server_trunking - Detect server IP address trunking
2044  *
2045  * @clp: nfs_client under test
2046  * @result: OUT: found nfs_client, or clp
2047  *
2048  * Returns zero or a negative errno.  If zero is returned,
2049  * an nfs_client pointer is planted in "result".
2050  *
2051  * Note: since we are invoked in process context, and
2052  * not from inside the state manager, we cannot use
2053  * nfs4_handle_reclaim_lease_error().
2054  */
2055 int nfs4_discover_server_trunking(struct nfs_client *clp,
2056                                   struct nfs_client **result)
2057 {
2058         const struct nfs4_state_recovery_ops *ops =
2059                                 clp->cl_mvops->reboot_recovery_ops;
2060         struct rpc_clnt *clnt;
2061         struct rpc_cred *cred;
2062         int i, status;
2063 
2064         dprintk("NFS: %s: testing '%s'\n", __func__, clp->cl_hostname);
2065 
2066         clnt = clp->cl_rpcclient;
2067         i = 0;
2068 
2069         mutex_lock(&nfs_clid_init_mutex);
2070 again:
2071         status  = -ENOENT;
2072         cred = nfs4_get_clid_cred(clp);
2073         if (cred == NULL)
2074                 goto out_unlock;
2075 
2076         status = ops->detect_trunking(clp, result, cred);
2077         put_rpccred(cred);
2078         switch (status) {
2079         case 0:
2080                 break;
2081         case -ETIMEDOUT:
2082                 if (clnt->cl_softrtry)
2083                         break;
2084         case -NFS4ERR_DELAY:
2085         case -EAGAIN:
2086                 ssleep(1);
2087         case -NFS4ERR_STALE_CLIENTID:
2088                 dprintk("NFS: %s after status %d, retrying\n",
2089                         __func__, status);
2090                 goto again;
2091         case -EACCES:
2092                 if (i++ == 0) {
2093                         nfs4_root_machine_cred(clp);
2094                         goto again;
2095                 }
2096                 if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX)
2097                         break;
2098         case -NFS4ERR_CLID_INUSE:
2099         case -NFS4ERR_WRONGSEC:
2100                 /* No point in retrying if we already used RPC_AUTH_UNIX */
2101                 if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX) {
2102                         status = -EPERM;
2103                         break;
2104                 }
2105                 clnt = rpc_clone_client_set_auth(clnt, RPC_AUTH_UNIX);
2106                 if (IS_ERR(clnt)) {
2107                         status = PTR_ERR(clnt);
2108                         break;
2109                 }
2110                 /* Note: this is safe because we haven't yet marked the
2111                  * client as ready, so we are the only user of
2112                  * clp->cl_rpcclient
2113                  */
2114                 clnt = xchg(&clp->cl_rpcclient, clnt);
2115                 rpc_shutdown_client(clnt);
2116                 clnt = clp->cl_rpcclient;
2117                 goto again;
2118 
2119         case -NFS4ERR_MINOR_VERS_MISMATCH:
2120                 status = -EPROTONOSUPPORT;
2121                 break;
2122 
2123         case -EKEYEXPIRED:
2124         case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
2125                                  * in nfs4_exchange_id */
2126                 status = -EKEYEXPIRED;
2127                 break;
2128         default:
2129                 pr_warn("NFS: %s unhandled error %d. Exiting with error EIO\n",
2130                                 __func__, status);
2131                 status = -EIO;
2132         }
2133 
2134 out_unlock:
2135         mutex_unlock(&nfs_clid_init_mutex);
2136         dprintk("NFS: %s: status = %d\n", __func__, status);
2137         return status;
2138 }
2139 
2140 #ifdef CONFIG_NFS_V4_1
2141 void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
2142 {
2143         struct nfs_client *clp = session->clp;
2144 
2145         switch (err) {
2146         default:
2147                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2148                 break;
2149         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
2150                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2151         }
2152         nfs4_schedule_lease_recovery(clp);
2153 }
2154 EXPORT_SYMBOL_GPL(nfs4_schedule_session_recovery);
2155 
2156 void nfs41_notify_server(struct nfs_client *clp)
2157 {
2158         /* Use CHECK_LEASE to ping the server with a SEQUENCE */
2159         set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
2160         nfs4_schedule_state_manager(clp);
2161 }
2162 
2163 static void nfs4_reset_all_state(struct nfs_client *clp)
2164 {
2165         if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2166                 set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
2167                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
2168                 nfs4_state_start_reclaim_nograce(clp);
2169                 dprintk("%s: scheduling reset of all state for server %s!\n",
2170                                 __func__, clp->cl_hostname);
2171                 nfs4_schedule_state_manager(clp);
2172         }
2173 }
2174 
2175 static void nfs41_handle_server_reboot(struct nfs_client *clp)
2176 {
2177         if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2178                 nfs4_state_start_reclaim_reboot(clp);
2179                 dprintk("%s: server %s rebooted!\n", __func__,
2180                                 clp->cl_hostname);
2181                 nfs4_schedule_state_manager(clp);
2182         }
2183 }
2184 
2185 static void nfs41_handle_all_state_revoked(struct nfs_client *clp)
2186 {
2187         nfs4_reset_all_state(clp);
2188         dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2189 }
2190 
2191 static void nfs41_handle_some_state_revoked(struct nfs_client *clp)
2192 {
2193         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_nograce);
2194         nfs4_schedule_state_manager(clp);
2195 
2196         dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2197 }
2198 
2199 static void nfs41_handle_recallable_state_revoked(struct nfs_client *clp)
2200 {
2201         /* FIXME: For now, we destroy all layouts. */
2202         pnfs_destroy_all_layouts(clp);
2203         /* FIXME: For now, we test all delegations+open state+locks. */
2204         nfs41_handle_some_state_revoked(clp);
2205         dprintk("%s: Recallable state revoked on server %s!\n", __func__,
2206                         clp->cl_hostname);
2207 }
2208 
2209 static void nfs41_handle_backchannel_fault(struct nfs_client *clp)
2210 {
2211         set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2212         nfs4_schedule_state_manager(clp);
2213 
2214         dprintk("%s: server %s declared a backchannel fault\n", __func__,
2215                         clp->cl_hostname);
2216 }
2217 
2218 static void nfs41_handle_cb_path_down(struct nfs_client *clp)
2219 {
2220         if (test_and_set_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2221                 &clp->cl_state) == 0)
2222                 nfs4_schedule_state_manager(clp);
2223 }
2224 
2225 void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags)
2226 {
2227         if (!flags)
2228                 return;
2229 
2230         dprintk("%s: \"%s\" (client ID %llx) flags=0x%08x\n",
2231                 __func__, clp->cl_hostname, clp->cl_clientid, flags);
2232 
2233         if (flags & SEQ4_STATUS_RESTART_RECLAIM_NEEDED)
2234                 nfs41_handle_server_reboot(clp);
2235         if (flags & (SEQ4_STATUS_EXPIRED_ALL_STATE_REVOKED))
2236                 nfs41_handle_all_state_revoked(clp);
2237         if (flags & (SEQ4_STATUS_EXPIRED_SOME_STATE_REVOKED |
2238                             SEQ4_STATUS_ADMIN_STATE_REVOKED))
2239                 nfs41_handle_some_state_revoked(clp);
2240         if (flags & SEQ4_STATUS_LEASE_MOVED)
2241                 nfs4_schedule_lease_moved_recovery(clp);
2242         if (flags & SEQ4_STATUS_RECALLABLE_STATE_REVOKED)
2243                 nfs41_handle_recallable_state_revoked(clp);
2244         if (flags & SEQ4_STATUS_BACKCHANNEL_FAULT)
2245                 nfs41_handle_backchannel_fault(clp);
2246         else if (flags & (SEQ4_STATUS_CB_PATH_DOWN |
2247                                 SEQ4_STATUS_CB_PATH_DOWN_SESSION))
2248                 nfs41_handle_cb_path_down(clp);
2249 }
2250 
2251 static int nfs4_reset_session(struct nfs_client *clp)
2252 {
2253         struct rpc_cred *cred;
2254         int status;
2255 
2256         if (!nfs4_has_session(clp))
2257                 return 0;
2258         nfs4_begin_drain_session(clp);
2259         cred = nfs4_get_clid_cred(clp);
2260         status = nfs4_proc_destroy_session(clp->cl_session, cred);
2261         switch (status) {
2262         case 0:
2263         case -NFS4ERR_BADSESSION:
2264         case -NFS4ERR_DEADSESSION:
2265                 break;
2266         case -NFS4ERR_BACK_CHAN_BUSY:
2267         case -NFS4ERR_DELAY:
2268                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2269                 status = 0;
2270                 ssleep(1);
2271                 goto out;
2272         default:
2273                 status = nfs4_recovery_handle_error(clp, status);
2274                 goto out;
2275         }
2276 
2277         memset(clp->cl_session->sess_id.data, 0, NFS4_MAX_SESSIONID_LEN);
2278         status = nfs4_proc_create_session(clp, cred);
2279         if (status) {
2280                 dprintk("%s: session reset failed with status %d for server %s!\n",
2281                         __func__, status, clp->cl_hostname);
2282                 status = nfs4_handle_reclaim_lease_error(clp, status);
2283                 goto out;
2284         }
2285         nfs41_finish_session_reset(clp);
2286         dprintk("%s: session reset was successful for server %s!\n",
2287                         __func__, clp->cl_hostname);
2288 out:
2289         if (cred)
2290                 put_rpccred(cred);
2291         return status;
2292 }
2293 
2294 static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2295 {
2296         struct rpc_cred *cred;
2297         int ret;
2298 
2299         if (!nfs4_has_session(clp))
2300                 return 0;
2301         nfs4_begin_drain_session(clp);
2302         cred = nfs4_get_clid_cred(clp);
2303         ret = nfs4_proc_bind_conn_to_session(clp, cred);
2304         if (cred)
2305                 put_rpccred(cred);
2306         clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2307         switch (ret) {
2308         case 0:
2309                 dprintk("%s: bind_conn_to_session was successful for server %s!\n",
2310                         __func__, clp->cl_hostname);
2311                 break;
2312         case -NFS4ERR_DELAY:
2313                 ssleep(1);
2314                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2315                 break;
2316         default:
2317                 return nfs4_recovery_handle_error(clp, ret);
2318         }
2319         return 0;
2320 }
2321 #else /* CONFIG_NFS_V4_1 */
2322 static int nfs4_reset_session(struct nfs_client *clp) { return 0; }
2323 
2324 static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2325 {
2326         return 0;
2327 }
2328 #endif /* CONFIG_NFS_V4_1 */
2329 
2330 static void nfs4_state_manager(struct nfs_client *clp)
2331 {
2332         int status = 0;
2333         const char *section = "", *section_sep = "";
2334 
2335         /* Ensure exclusive access to NFSv4 state */
2336         do {
2337                 if (test_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state)) {
2338                         section = "purge state";
2339                         status = nfs4_purge_lease(clp);
2340                         if (status < 0)
2341                                 goto out_error;
2342                         continue;
2343                 }
2344 
2345                 if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state)) {
2346                         section = "lease expired";
2347                         /* We're going to have to re-establish a clientid */
2348                         status = nfs4_reclaim_lease(clp);
2349                         if (status < 0)
2350                                 goto out_error;
2351                         continue;
2352                 }
2353 
2354                 /* Initialize or reset the session */
2355                 if (test_and_clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state)) {
2356                         section = "reset session";
2357                         status = nfs4_reset_session(clp);
2358                         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
2359                                 continue;
2360                         if (status < 0)
2361                                 goto out_error;
2362                 }
2363 
2364                 /* Send BIND_CONN_TO_SESSION */
2365                 if (test_and_clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2366                                 &clp->cl_state)) {
2367                         section = "bind conn to session";
2368                         status = nfs4_bind_conn_to_session(clp);
2369                         if (status < 0)
2370                                 goto out_error;
2371                         continue;
2372                 }
2373 
2374                 if (test_and_clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state)) {
2375                         section = "check lease";
2376                         status = nfs4_check_lease(clp);
2377                         if (status < 0)
2378                                 goto out_error;
2379                         continue;
2380                 }
2381 
2382                 if (test_and_clear_bit(NFS4CLNT_MOVED, &clp->cl_state)) {
2383                         section = "migration";
2384                         status = nfs4_handle_migration(clp);
2385                         if (status < 0)
2386                                 goto out_error;
2387                 }
2388 
2389                 if (test_and_clear_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state)) {
2390                         section = "lease moved";
2391                         status = nfs4_handle_lease_moved(clp);
2392                         if (status < 0)
2393                                 goto out_error;
2394                 }
2395 
2396                 /* First recover reboot state... */
2397                 if (test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state)) {
2398                         section = "reclaim reboot";
2399                         status = nfs4_do_reclaim(clp,
2400                                 clp->cl_mvops->reboot_recovery_ops);
2401                         if (status == -EAGAIN)
2402                                 continue;
2403                         if (status < 0)
2404                                 goto out_error;
2405                         nfs4_state_end_reclaim_reboot(clp);
2406                 }
2407 
2408                 /* Now recover expired state... */
2409                 if (test_and_clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state)) {
2410                         section = "reclaim nograce";
2411                         status = nfs4_do_reclaim(clp,
2412                                 clp->cl_mvops->nograce_recovery_ops);
2413                         if (status == -EAGAIN)
2414                                 continue;
2415                         if (status < 0)
2416                                 goto out_error;
2417                 }
2418 
2419                 nfs4_end_drain_session(clp);
2420                 if (test_and_clear_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) {
2421                         nfs_client_return_marked_delegations(clp);
2422                         continue;
2423                 }
2424 
2425                 nfs4_clear_state_manager_bit(clp);
2426                 /* Did we race with an attempt to give us more work? */
2427                 if (clp->cl_state == 0)
2428                         break;
2429                 if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
2430                         break;
2431         } while (atomic_read(&clp->cl_count) > 1);
2432         return;
2433 out_error:
2434         if (strlen(section))
2435                 section_sep = ": ";
2436         pr_warn_ratelimited("NFS: state manager%s%s failed on NFSv4 server %s"
2437                         " with error %d\n", section_sep, section,
2438                         clp->cl_hostname, -status);
2439         ssleep(1);
2440         nfs4_end_drain_session(clp);
2441         nfs4_clear_state_manager_bit(clp);
2442 }
2443 
2444 static int nfs4_run_state_manager(void *ptr)
2445 {
2446         struct nfs_client *clp = ptr;
2447 
2448         allow_signal(SIGKILL);
2449         nfs4_state_manager(clp);
2450         nfs_put_client(clp);
2451         module_put_and_exit(0);
2452         return 0;
2453 }
2454 
2455 /*
2456  * Local variables:
2457  *  c-basic-offset: 8
2458  * End:
2459  */
2460 

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