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Linux/fs/nfs/nfs4state.c

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  1 /*
  2  *  fs/nfs/nfs4state.c
  3  *
  4  *  Client-side XDR for NFSv4.
  5  *
  6  *  Copyright (c) 2002 The Regents of the University of Michigan.
  7  *  All rights reserved.
  8  *
  9  *  Kendrick Smith <kmsmith@umich.edu>
 10  *
 11  *  Redistribution and use in source and binary forms, with or without
 12  *  modification, are permitted provided that the following conditions
 13  *  are met:
 14  *
 15  *  1. Redistributions of source code must retain the above copyright
 16  *     notice, this list of conditions and the following disclaimer.
 17  *  2. Redistributions in binary form must reproduce the above copyright
 18  *     notice, this list of conditions and the following disclaimer in the
 19  *     documentation and/or other materials provided with the distribution.
 20  *  3. Neither the name of the University nor the names of its
 21  *     contributors may be used to endorse or promote products derived
 22  *     from this software without specific prior written permission.
 23  *
 24  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
 25  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 26  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 27  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 28  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 29  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 30  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
 31  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
 32  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 33  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 34  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 35  *
 36  * Implementation of the NFSv4 state model.  For the time being,
 37  * this is minimal, but will be made much more complex in a
 38  * subsequent patch.
 39  */
 40 
 41 #include <linux/kernel.h>
 42 #include <linux/slab.h>
 43 #include <linux/fs.h>
 44 #include <linux/nfs_fs.h>
 45 #include <linux/kthread.h>
 46 #include <linux/module.h>
 47 #include <linux/random.h>
 48 #include <linux/ratelimit.h>
 49 #include <linux/workqueue.h>
 50 #include <linux/bitops.h>
 51 #include <linux/jiffies.h>
 52 
 53 #include <linux/sunrpc/clnt.h>
 54 
 55 #include "nfs4_fs.h"
 56 #include "callback.h"
 57 #include "delegation.h"
 58 #include "internal.h"
 59 #include "nfs4idmap.h"
 60 #include "nfs4session.h"
 61 #include "pnfs.h"
 62 #include "netns.h"
 63 
 64 #define NFSDBG_FACILITY         NFSDBG_STATE
 65 
 66 #define OPENOWNER_POOL_SIZE     8
 67 
 68 const nfs4_stateid zero_stateid = {
 69         { .data = { 0 } },
 70         .type = NFS4_SPECIAL_STATEID_TYPE,
 71 };
 72 const nfs4_stateid invalid_stateid = {
 73         {
 74                 /* Funky initialiser keeps older gcc versions happy */
 75                 .data = { 0xff, 0xff, 0xff, 0xff, 0 },
 76         },
 77         .type = NFS4_INVALID_STATEID_TYPE,
 78 };
 79 
 80 const nfs4_stateid current_stateid = {
 81         {
 82                 /* Funky initialiser keeps older gcc versions happy */
 83                 .data = { 0x0, 0x0, 0x0, 0x1, 0 },
 84         },
 85         .type = NFS4_SPECIAL_STATEID_TYPE,
 86 };
 87 
 88 static DEFINE_MUTEX(nfs_clid_init_mutex);
 89 
 90 static int nfs4_setup_state_renewal(struct nfs_client *clp)
 91 {
 92         int status;
 93         struct nfs_fsinfo fsinfo;
 94         unsigned long now;
 95 
 96         if (!test_bit(NFS_CS_CHECK_LEASE_TIME, &clp->cl_res_state)) {
 97                 nfs4_schedule_state_renewal(clp);
 98                 return 0;
 99         }
100 
101         now = jiffies;
102         status = nfs4_proc_get_lease_time(clp, &fsinfo);
103         if (status == 0) {
104                 nfs4_set_lease_period(clp, fsinfo.lease_time * HZ, now);
105                 nfs4_schedule_state_renewal(clp);
106         }
107 
108         return status;
109 }
110 
111 int nfs4_init_clientid(struct nfs_client *clp, const struct cred *cred)
112 {
113         struct nfs4_setclientid_res clid = {
114                 .clientid = clp->cl_clientid,
115                 .confirm = clp->cl_confirm,
116         };
117         unsigned short port;
118         int status;
119         struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
120 
121         if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
122                 goto do_confirm;
123         port = nn->nfs_callback_tcpport;
124         if (clp->cl_addr.ss_family == AF_INET6)
125                 port = nn->nfs_callback_tcpport6;
126 
127         status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
128         if (status != 0)
129                 goto out;
130         clp->cl_clientid = clid.clientid;
131         clp->cl_confirm = clid.confirm;
132         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
133 do_confirm:
134         status = nfs4_proc_setclientid_confirm(clp, &clid, cred);
135         if (status != 0)
136                 goto out;
137         clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
138         nfs4_setup_state_renewal(clp);
139 out:
140         return status;
141 }
142 
143 /**
144  * nfs40_discover_server_trunking - Detect server IP address trunking (mv0)
145  *
146  * @clp: nfs_client under test
147  * @result: OUT: found nfs_client, or clp
148  * @cred: credential to use for trunking test
149  *
150  * Returns zero, a negative errno, or a negative NFS4ERR status.
151  * If zero is returned, an nfs_client pointer is planted in
152  * "result".
153  *
154  * Note: The returned client may not yet be marked ready.
155  */
156 int nfs40_discover_server_trunking(struct nfs_client *clp,
157                                    struct nfs_client **result,
158                                    const struct cred *cred)
159 {
160         struct nfs4_setclientid_res clid = {
161                 .clientid = clp->cl_clientid,
162                 .confirm = clp->cl_confirm,
163         };
164         struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
165         unsigned short port;
166         int status;
167 
168         port = nn->nfs_callback_tcpport;
169         if (clp->cl_addr.ss_family == AF_INET6)
170                 port = nn->nfs_callback_tcpport6;
171 
172         status = nfs4_proc_setclientid(clp, NFS4_CALLBACK, port, cred, &clid);
173         if (status != 0)
174                 goto out;
175         clp->cl_clientid = clid.clientid;
176         clp->cl_confirm = clid.confirm;
177 
178         status = nfs40_walk_client_list(clp, result, cred);
179         if (status == 0) {
180                 /* Sustain the lease, even if it's empty.  If the clientid4
181                  * goes stale it's of no use for trunking discovery. */
182                 nfs4_schedule_state_renewal(*result);
183 
184                 /* If the client state need to recover, do it. */
185                 if (clp->cl_state)
186                         nfs4_schedule_state_manager(clp);
187         }
188 out:
189         return status;
190 }
191 
192 const struct cred *nfs4_get_machine_cred(struct nfs_client *clp)
193 {
194         return get_cred(rpc_machine_cred());
195 }
196 
197 static void nfs4_root_machine_cred(struct nfs_client *clp)
198 {
199 
200         /* Force root creds instead of machine */
201         clp->cl_principal = NULL;
202         clp->cl_rpcclient->cl_principal = NULL;
203 }
204 
205 static const struct cred *
206 nfs4_get_renew_cred_server_locked(struct nfs_server *server)
207 {
208         const struct cred *cred = NULL;
209         struct nfs4_state_owner *sp;
210         struct rb_node *pos;
211 
212         for (pos = rb_first(&server->state_owners);
213              pos != NULL;
214              pos = rb_next(pos)) {
215                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
216                 if (list_empty(&sp->so_states))
217                         continue;
218                 cred = get_cred(sp->so_cred);
219                 break;
220         }
221         return cred;
222 }
223 
224 /**
225  * nfs4_get_renew_cred - Acquire credential for a renew operation
226  * @clp: client state handle
227  *
228  * Returns an rpc_cred with reference count bumped, or NULL.
229  * Caller must hold clp->cl_lock.
230  */
231 const struct cred *nfs4_get_renew_cred(struct nfs_client *clp)
232 {
233         const struct cred *cred = NULL;
234         struct nfs_server *server;
235 
236         /* Use machine credentials if available */
237         cred = nfs4_get_machine_cred(clp);
238         if (cred != NULL)
239                 goto out;
240 
241         spin_lock(&clp->cl_lock);
242         rcu_read_lock();
243         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
244                 cred = nfs4_get_renew_cred_server_locked(server);
245                 if (cred != NULL)
246                         break;
247         }
248         rcu_read_unlock();
249         spin_unlock(&clp->cl_lock);
250 
251 out:
252         return cred;
253 }
254 
255 static void nfs4_end_drain_slot_table(struct nfs4_slot_table *tbl)
256 {
257         if (test_and_clear_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state)) {
258                 spin_lock(&tbl->slot_tbl_lock);
259                 nfs41_wake_slot_table(tbl);
260                 spin_unlock(&tbl->slot_tbl_lock);
261         }
262 }
263 
264 static void nfs4_end_drain_session(struct nfs_client *clp)
265 {
266         struct nfs4_session *ses = clp->cl_session;
267 
268         if (clp->cl_slot_tbl) {
269                 nfs4_end_drain_slot_table(clp->cl_slot_tbl);
270                 return;
271         }
272 
273         if (ses != NULL) {
274                 nfs4_end_drain_slot_table(&ses->bc_slot_table);
275                 nfs4_end_drain_slot_table(&ses->fc_slot_table);
276         }
277 }
278 
279 static int nfs4_drain_slot_tbl(struct nfs4_slot_table *tbl)
280 {
281         set_bit(NFS4_SLOT_TBL_DRAINING, &tbl->slot_tbl_state);
282         spin_lock(&tbl->slot_tbl_lock);
283         if (tbl->highest_used_slotid != NFS4_NO_SLOT) {
284                 reinit_completion(&tbl->complete);
285                 spin_unlock(&tbl->slot_tbl_lock);
286                 return wait_for_completion_interruptible(&tbl->complete);
287         }
288         spin_unlock(&tbl->slot_tbl_lock);
289         return 0;
290 }
291 
292 static int nfs4_begin_drain_session(struct nfs_client *clp)
293 {
294         struct nfs4_session *ses = clp->cl_session;
295         int ret;
296 
297         if (clp->cl_slot_tbl)
298                 return nfs4_drain_slot_tbl(clp->cl_slot_tbl);
299 
300         /* back channel */
301         ret = nfs4_drain_slot_tbl(&ses->bc_slot_table);
302         if (ret)
303                 return ret;
304         /* fore channel */
305         return nfs4_drain_slot_tbl(&ses->fc_slot_table);
306 }
307 
308 #if defined(CONFIG_NFS_V4_1)
309 
310 static void nfs41_finish_session_reset(struct nfs_client *clp)
311 {
312         clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
313         clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
314         /* create_session negotiated new slot table */
315         clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
316         nfs4_setup_state_renewal(clp);
317 }
318 
319 int nfs41_init_clientid(struct nfs_client *clp, const struct cred *cred)
320 {
321         int status;
322 
323         if (test_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state))
324                 goto do_confirm;
325         status = nfs4_proc_exchange_id(clp, cred);
326         if (status != 0)
327                 goto out;
328         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
329 do_confirm:
330         status = nfs4_proc_create_session(clp, cred);
331         if (status != 0)
332                 goto out;
333         nfs41_finish_session_reset(clp);
334         nfs_mark_client_ready(clp, NFS_CS_READY);
335 out:
336         return status;
337 }
338 
339 /**
340  * nfs41_discover_server_trunking - Detect server IP address trunking (mv1)
341  *
342  * @clp: nfs_client under test
343  * @result: OUT: found nfs_client, or clp
344  * @cred: credential to use for trunking test
345  *
346  * Returns NFS4_OK, a negative errno, or a negative NFS4ERR status.
347  * If NFS4_OK is returned, an nfs_client pointer is planted in
348  * "result".
349  *
350  * Note: The returned client may not yet be marked ready.
351  */
352 int nfs41_discover_server_trunking(struct nfs_client *clp,
353                                    struct nfs_client **result,
354                                    const struct cred *cred)
355 {
356         int status;
357 
358         status = nfs4_proc_exchange_id(clp, cred);
359         if (status != NFS4_OK)
360                 return status;
361 
362         status = nfs41_walk_client_list(clp, result, cred);
363         if (status < 0)
364                 return status;
365         if (clp != *result)
366                 return 0;
367 
368         /*
369          * Purge state if the client id was established in a prior
370          * instance and the client id could not have arrived on the
371          * server via Transparent State Migration.
372          */
373         if (clp->cl_exchange_flags & EXCHGID4_FLAG_CONFIRMED_R) {
374                 if (!test_bit(NFS_CS_TSM_POSSIBLE, &clp->cl_flags))
375                         set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
376                 else
377                         set_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
378         }
379         nfs4_schedule_state_manager(clp);
380         status = nfs_wait_client_init_complete(clp);
381         if (status < 0)
382                 nfs_put_client(clp);
383         return status;
384 }
385 
386 #endif /* CONFIG_NFS_V4_1 */
387 
388 /**
389  * nfs4_get_clid_cred - Acquire credential for a setclientid operation
390  * @clp: client state handle
391  *
392  * Returns a cred with reference count bumped, or NULL.
393  */
394 const struct cred *nfs4_get_clid_cred(struct nfs_client *clp)
395 {
396         const struct cred *cred;
397 
398         cred = nfs4_get_machine_cred(clp);
399         return cred;
400 }
401 
402 static struct nfs4_state_owner *
403 nfs4_find_state_owner_locked(struct nfs_server *server, const struct cred *cred)
404 {
405         struct rb_node **p = &server->state_owners.rb_node,
406                        *parent = NULL;
407         struct nfs4_state_owner *sp;
408         int cmp;
409 
410         while (*p != NULL) {
411                 parent = *p;
412                 sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
413                 cmp = cred_fscmp(cred, sp->so_cred);
414 
415                 if (cmp < 0)
416                         p = &parent->rb_left;
417                 else if (cmp > 0)
418                         p = &parent->rb_right;
419                 else {
420                         if (!list_empty(&sp->so_lru))
421                                 list_del_init(&sp->so_lru);
422                         atomic_inc(&sp->so_count);
423                         return sp;
424                 }
425         }
426         return NULL;
427 }
428 
429 static struct nfs4_state_owner *
430 nfs4_insert_state_owner_locked(struct nfs4_state_owner *new)
431 {
432         struct nfs_server *server = new->so_server;
433         struct rb_node **p = &server->state_owners.rb_node,
434                        *parent = NULL;
435         struct nfs4_state_owner *sp;
436         int cmp;
437 
438         while (*p != NULL) {
439                 parent = *p;
440                 sp = rb_entry(parent, struct nfs4_state_owner, so_server_node);
441                 cmp = cred_fscmp(new->so_cred, sp->so_cred);
442 
443                 if (cmp < 0)
444                         p = &parent->rb_left;
445                 else if (cmp > 0)
446                         p = &parent->rb_right;
447                 else {
448                         if (!list_empty(&sp->so_lru))
449                                 list_del_init(&sp->so_lru);
450                         atomic_inc(&sp->so_count);
451                         return sp;
452                 }
453         }
454         rb_link_node(&new->so_server_node, parent, p);
455         rb_insert_color(&new->so_server_node, &server->state_owners);
456         return new;
457 }
458 
459 static void
460 nfs4_remove_state_owner_locked(struct nfs4_state_owner *sp)
461 {
462         struct nfs_server *server = sp->so_server;
463 
464         if (!RB_EMPTY_NODE(&sp->so_server_node))
465                 rb_erase(&sp->so_server_node, &server->state_owners);
466 }
467 
468 static void
469 nfs4_init_seqid_counter(struct nfs_seqid_counter *sc)
470 {
471         sc->create_time = ktime_get();
472         sc->flags = 0;
473         sc->counter = 0;
474         spin_lock_init(&sc->lock);
475         INIT_LIST_HEAD(&sc->list);
476         rpc_init_wait_queue(&sc->wait, "Seqid_waitqueue");
477 }
478 
479 static void
480 nfs4_destroy_seqid_counter(struct nfs_seqid_counter *sc)
481 {
482         rpc_destroy_wait_queue(&sc->wait);
483 }
484 
485 /*
486  * nfs4_alloc_state_owner(): this is called on the OPEN or CREATE path to
487  * create a new state_owner.
488  *
489  */
490 static struct nfs4_state_owner *
491 nfs4_alloc_state_owner(struct nfs_server *server,
492                 const struct cred *cred,
493                 gfp_t gfp_flags)
494 {
495         struct nfs4_state_owner *sp;
496 
497         sp = kzalloc(sizeof(*sp), gfp_flags);
498         if (!sp)
499                 return NULL;
500         sp->so_seqid.owner_id = ida_simple_get(&server->openowner_id, 0, 0,
501                                                 gfp_flags);
502         if (sp->so_seqid.owner_id < 0) {
503                 kfree(sp);
504                 return NULL;
505         }
506         sp->so_server = server;
507         sp->so_cred = get_cred(cred);
508         spin_lock_init(&sp->so_lock);
509         INIT_LIST_HEAD(&sp->so_states);
510         nfs4_init_seqid_counter(&sp->so_seqid);
511         atomic_set(&sp->so_count, 1);
512         INIT_LIST_HEAD(&sp->so_lru);
513         seqcount_init(&sp->so_reclaim_seqcount);
514         mutex_init(&sp->so_delegreturn_mutex);
515         return sp;
516 }
517 
518 static void
519 nfs4_reset_state_owner(struct nfs4_state_owner *sp)
520 {
521         /* This state_owner is no longer usable, but must
522          * remain in place so that state recovery can find it
523          * and the opens associated with it.
524          * It may also be used for new 'open' request to
525          * return a delegation to the server.
526          * So update the 'create_time' so that it looks like
527          * a new state_owner.  This will cause the server to
528          * request an OPEN_CONFIRM to start a new sequence.
529          */
530         sp->so_seqid.create_time = ktime_get();
531 }
532 
533 static void nfs4_free_state_owner(struct nfs4_state_owner *sp)
534 {
535         nfs4_destroy_seqid_counter(&sp->so_seqid);
536         put_cred(sp->so_cred);
537         ida_simple_remove(&sp->so_server->openowner_id, sp->so_seqid.owner_id);
538         kfree(sp);
539 }
540 
541 static void nfs4_gc_state_owners(struct nfs_server *server)
542 {
543         struct nfs_client *clp = server->nfs_client;
544         struct nfs4_state_owner *sp, *tmp;
545         unsigned long time_min, time_max;
546         LIST_HEAD(doomed);
547 
548         spin_lock(&clp->cl_lock);
549         time_max = jiffies;
550         time_min = (long)time_max - (long)clp->cl_lease_time;
551         list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
552                 /* NB: LRU is sorted so that oldest is at the head */
553                 if (time_in_range(sp->so_expires, time_min, time_max))
554                         break;
555                 list_move(&sp->so_lru, &doomed);
556                 nfs4_remove_state_owner_locked(sp);
557         }
558         spin_unlock(&clp->cl_lock);
559 
560         list_for_each_entry_safe(sp, tmp, &doomed, so_lru) {
561                 list_del(&sp->so_lru);
562                 nfs4_free_state_owner(sp);
563         }
564 }
565 
566 /**
567  * nfs4_get_state_owner - Look up a state owner given a credential
568  * @server: nfs_server to search
569  * @cred: RPC credential to match
570  * @gfp_flags: allocation mode
571  *
572  * Returns a pointer to an instantiated nfs4_state_owner struct, or NULL.
573  */
574 struct nfs4_state_owner *nfs4_get_state_owner(struct nfs_server *server,
575                                               const struct cred *cred,
576                                               gfp_t gfp_flags)
577 {
578         struct nfs_client *clp = server->nfs_client;
579         struct nfs4_state_owner *sp, *new;
580 
581         spin_lock(&clp->cl_lock);
582         sp = nfs4_find_state_owner_locked(server, cred);
583         spin_unlock(&clp->cl_lock);
584         if (sp != NULL)
585                 goto out;
586         new = nfs4_alloc_state_owner(server, cred, gfp_flags);
587         if (new == NULL)
588                 goto out;
589         spin_lock(&clp->cl_lock);
590         sp = nfs4_insert_state_owner_locked(new);
591         spin_unlock(&clp->cl_lock);
592         if (sp != new)
593                 nfs4_free_state_owner(new);
594 out:
595         nfs4_gc_state_owners(server);
596         return sp;
597 }
598 
599 /**
600  * nfs4_put_state_owner - Release a nfs4_state_owner
601  * @sp: state owner data to release
602  *
603  * Note that we keep released state owners on an LRU
604  * list.
605  * This caches valid state owners so that they can be
606  * reused, to avoid the OPEN_CONFIRM on minor version 0.
607  * It also pins the uniquifier of dropped state owners for
608  * a while, to ensure that those state owner names are
609  * never reused.
610  */
611 void nfs4_put_state_owner(struct nfs4_state_owner *sp)
612 {
613         struct nfs_server *server = sp->so_server;
614         struct nfs_client *clp = server->nfs_client;
615 
616         if (!atomic_dec_and_lock(&sp->so_count, &clp->cl_lock))
617                 return;
618 
619         sp->so_expires = jiffies;
620         list_add_tail(&sp->so_lru, &server->state_owners_lru);
621         spin_unlock(&clp->cl_lock);
622 }
623 
624 /**
625  * nfs4_purge_state_owners - Release all cached state owners
626  * @server: nfs_server with cached state owners to release
627  * @head: resulting list of state owners
628  *
629  * Called at umount time.  Remaining state owners will be on
630  * the LRU with ref count of zero.
631  * Note that the state owners are not freed, but are added
632  * to the list @head, which can later be used as an argument
633  * to nfs4_free_state_owners.
634  */
635 void nfs4_purge_state_owners(struct nfs_server *server, struct list_head *head)
636 {
637         struct nfs_client *clp = server->nfs_client;
638         struct nfs4_state_owner *sp, *tmp;
639 
640         spin_lock(&clp->cl_lock);
641         list_for_each_entry_safe(sp, tmp, &server->state_owners_lru, so_lru) {
642                 list_move(&sp->so_lru, head);
643                 nfs4_remove_state_owner_locked(sp);
644         }
645         spin_unlock(&clp->cl_lock);
646 }
647 
648 /**
649  * nfs4_purge_state_owners - Release all cached state owners
650  * @head: resulting list of state owners
651  *
652  * Frees a list of state owners that was generated by
653  * nfs4_purge_state_owners
654  */
655 void nfs4_free_state_owners(struct list_head *head)
656 {
657         struct nfs4_state_owner *sp, *tmp;
658 
659         list_for_each_entry_safe(sp, tmp, head, so_lru) {
660                 list_del(&sp->so_lru);
661                 nfs4_free_state_owner(sp);
662         }
663 }
664 
665 static struct nfs4_state *
666 nfs4_alloc_open_state(void)
667 {
668         struct nfs4_state *state;
669 
670         state = kzalloc(sizeof(*state), GFP_NOFS);
671         if (!state)
672                 return NULL;
673         refcount_set(&state->count, 1);
674         INIT_LIST_HEAD(&state->lock_states);
675         spin_lock_init(&state->state_lock);
676         seqlock_init(&state->seqlock);
677         init_waitqueue_head(&state->waitq);
678         return state;
679 }
680 
681 void
682 nfs4_state_set_mode_locked(struct nfs4_state *state, fmode_t fmode)
683 {
684         if (state->state == fmode)
685                 return;
686         /* NB! List reordering - see the reclaim code for why.  */
687         if ((fmode & FMODE_WRITE) != (state->state & FMODE_WRITE)) {
688                 if (fmode & FMODE_WRITE)
689                         list_move(&state->open_states, &state->owner->so_states);
690                 else
691                         list_move_tail(&state->open_states, &state->owner->so_states);
692         }
693         state->state = fmode;
694 }
695 
696 static struct nfs4_state *
697 __nfs4_find_state_byowner(struct inode *inode, struct nfs4_state_owner *owner)
698 {
699         struct nfs_inode *nfsi = NFS_I(inode);
700         struct nfs4_state *state;
701 
702         list_for_each_entry_rcu(state, &nfsi->open_states, inode_states) {
703                 if (state->owner != owner)
704                         continue;
705                 if (!nfs4_valid_open_stateid(state))
706                         continue;
707                 if (refcount_inc_not_zero(&state->count))
708                         return state;
709         }
710         return NULL;
711 }
712 
713 static void
714 nfs4_free_open_state(struct nfs4_state *state)
715 {
716         kfree_rcu(state, rcu_head);
717 }
718 
719 struct nfs4_state *
720 nfs4_get_open_state(struct inode *inode, struct nfs4_state_owner *owner)
721 {
722         struct nfs4_state *state, *new;
723         struct nfs_inode *nfsi = NFS_I(inode);
724 
725         rcu_read_lock();
726         state = __nfs4_find_state_byowner(inode, owner);
727         rcu_read_unlock();
728         if (state)
729                 goto out;
730         new = nfs4_alloc_open_state();
731         spin_lock(&owner->so_lock);
732         spin_lock(&inode->i_lock);
733         state = __nfs4_find_state_byowner(inode, owner);
734         if (state == NULL && new != NULL) {
735                 state = new;
736                 state->owner = owner;
737                 atomic_inc(&owner->so_count);
738                 list_add_rcu(&state->inode_states, &nfsi->open_states);
739                 ihold(inode);
740                 state->inode = inode;
741                 spin_unlock(&inode->i_lock);
742                 /* Note: The reclaim code dictates that we add stateless
743                  * and read-only stateids to the end of the list */
744                 list_add_tail(&state->open_states, &owner->so_states);
745                 spin_unlock(&owner->so_lock);
746         } else {
747                 spin_unlock(&inode->i_lock);
748                 spin_unlock(&owner->so_lock);
749                 if (new)
750                         nfs4_free_open_state(new);
751         }
752 out:
753         return state;
754 }
755 
756 void nfs4_put_open_state(struct nfs4_state *state)
757 {
758         struct inode *inode = state->inode;
759         struct nfs4_state_owner *owner = state->owner;
760 
761         if (!refcount_dec_and_lock(&state->count, &owner->so_lock))
762                 return;
763         spin_lock(&inode->i_lock);
764         list_del_rcu(&state->inode_states);
765         list_del(&state->open_states);
766         spin_unlock(&inode->i_lock);
767         spin_unlock(&owner->so_lock);
768         iput(inode);
769         nfs4_free_open_state(state);
770         nfs4_put_state_owner(owner);
771 }
772 
773 /*
774  * Close the current file.
775  */
776 static void __nfs4_close(struct nfs4_state *state,
777                 fmode_t fmode, gfp_t gfp_mask, int wait)
778 {
779         struct nfs4_state_owner *owner = state->owner;
780         int call_close = 0;
781         fmode_t newstate;
782 
783         atomic_inc(&owner->so_count);
784         /* Protect against nfs4_find_state() */
785         spin_lock(&owner->so_lock);
786         switch (fmode & (FMODE_READ | FMODE_WRITE)) {
787                 case FMODE_READ:
788                         state->n_rdonly--;
789                         break;
790                 case FMODE_WRITE:
791                         state->n_wronly--;
792                         break;
793                 case FMODE_READ|FMODE_WRITE:
794                         state->n_rdwr--;
795         }
796         newstate = FMODE_READ|FMODE_WRITE;
797         if (state->n_rdwr == 0) {
798                 if (state->n_rdonly == 0) {
799                         newstate &= ~FMODE_READ;
800                         call_close |= test_bit(NFS_O_RDONLY_STATE, &state->flags);
801                         call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
802                 }
803                 if (state->n_wronly == 0) {
804                         newstate &= ~FMODE_WRITE;
805                         call_close |= test_bit(NFS_O_WRONLY_STATE, &state->flags);
806                         call_close |= test_bit(NFS_O_RDWR_STATE, &state->flags);
807                 }
808                 if (newstate == 0)
809                         clear_bit(NFS_DELEGATED_STATE, &state->flags);
810         }
811         nfs4_state_set_mode_locked(state, newstate);
812         spin_unlock(&owner->so_lock);
813 
814         if (!call_close) {
815                 nfs4_put_open_state(state);
816                 nfs4_put_state_owner(owner);
817         } else
818                 nfs4_do_close(state, gfp_mask, wait);
819 }
820 
821 void nfs4_close_state(struct nfs4_state *state, fmode_t fmode)
822 {
823         __nfs4_close(state, fmode, GFP_NOFS, 0);
824 }
825 
826 void nfs4_close_sync(struct nfs4_state *state, fmode_t fmode)
827 {
828         __nfs4_close(state, fmode, GFP_KERNEL, 1);
829 }
830 
831 /*
832  * Search the state->lock_states for an existing lock_owner
833  * that is compatible with either of the given owners.
834  * If the second is non-zero, then the first refers to a Posix-lock
835  * owner (current->files) and the second refers to a flock/OFD
836  * owner (struct file*).  In that case, prefer a match for the first
837  * owner.
838  * If both sorts of locks are held on the one file we cannot know
839  * which stateid was intended to be used, so a "correct" choice cannot
840  * be made.  Failing that, a "consistent" choice is preferable.  The
841  * consistent choice we make is to prefer the first owner, that of a
842  * Posix lock.
843  */
844 static struct nfs4_lock_state *
845 __nfs4_find_lock_state(struct nfs4_state *state,
846                        fl_owner_t fl_owner, fl_owner_t fl_owner2)
847 {
848         struct nfs4_lock_state *pos, *ret = NULL;
849         list_for_each_entry(pos, &state->lock_states, ls_locks) {
850                 if (pos->ls_owner == fl_owner) {
851                         ret = pos;
852                         break;
853                 }
854                 if (pos->ls_owner == fl_owner2)
855                         ret = pos;
856         }
857         if (ret)
858                 refcount_inc(&ret->ls_count);
859         return ret;
860 }
861 
862 /*
863  * Return a compatible lock_state. If no initialized lock_state structure
864  * exists, return an uninitialized one.
865  *
866  */
867 static struct nfs4_lock_state *nfs4_alloc_lock_state(struct nfs4_state *state, fl_owner_t fl_owner)
868 {
869         struct nfs4_lock_state *lsp;
870         struct nfs_server *server = state->owner->so_server;
871 
872         lsp = kzalloc(sizeof(*lsp), GFP_NOFS);
873         if (lsp == NULL)
874                 return NULL;
875         nfs4_init_seqid_counter(&lsp->ls_seqid);
876         refcount_set(&lsp->ls_count, 1);
877         lsp->ls_state = state;
878         lsp->ls_owner = fl_owner;
879         lsp->ls_seqid.owner_id = ida_simple_get(&server->lockowner_id, 0, 0, GFP_NOFS);
880         if (lsp->ls_seqid.owner_id < 0)
881                 goto out_free;
882         INIT_LIST_HEAD(&lsp->ls_locks);
883         return lsp;
884 out_free:
885         kfree(lsp);
886         return NULL;
887 }
888 
889 void nfs4_free_lock_state(struct nfs_server *server, struct nfs4_lock_state *lsp)
890 {
891         ida_simple_remove(&server->lockowner_id, lsp->ls_seqid.owner_id);
892         nfs4_destroy_seqid_counter(&lsp->ls_seqid);
893         kfree(lsp);
894 }
895 
896 /*
897  * Return a compatible lock_state. If no initialized lock_state structure
898  * exists, return an uninitialized one.
899  *
900  */
901 static struct nfs4_lock_state *nfs4_get_lock_state(struct nfs4_state *state, fl_owner_t owner)
902 {
903         struct nfs4_lock_state *lsp, *new = NULL;
904         
905         for(;;) {
906                 spin_lock(&state->state_lock);
907                 lsp = __nfs4_find_lock_state(state, owner, NULL);
908                 if (lsp != NULL)
909                         break;
910                 if (new != NULL) {
911                         list_add(&new->ls_locks, &state->lock_states);
912                         set_bit(LK_STATE_IN_USE, &state->flags);
913                         lsp = new;
914                         new = NULL;
915                         break;
916                 }
917                 spin_unlock(&state->state_lock);
918                 new = nfs4_alloc_lock_state(state, owner);
919                 if (new == NULL)
920                         return NULL;
921         }
922         spin_unlock(&state->state_lock);
923         if (new != NULL)
924                 nfs4_free_lock_state(state->owner->so_server, new);
925         return lsp;
926 }
927 
928 /*
929  * Release reference to lock_state, and free it if we see that
930  * it is no longer in use
931  */
932 void nfs4_put_lock_state(struct nfs4_lock_state *lsp)
933 {
934         struct nfs_server *server;
935         struct nfs4_state *state;
936 
937         if (lsp == NULL)
938                 return;
939         state = lsp->ls_state;
940         if (!refcount_dec_and_lock(&lsp->ls_count, &state->state_lock))
941                 return;
942         list_del(&lsp->ls_locks);
943         if (list_empty(&state->lock_states))
944                 clear_bit(LK_STATE_IN_USE, &state->flags);
945         spin_unlock(&state->state_lock);
946         server = state->owner->so_server;
947         if (test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags)) {
948                 struct nfs_client *clp = server->nfs_client;
949 
950                 clp->cl_mvops->free_lock_state(server, lsp);
951         } else
952                 nfs4_free_lock_state(server, lsp);
953 }
954 
955 static void nfs4_fl_copy_lock(struct file_lock *dst, struct file_lock *src)
956 {
957         struct nfs4_lock_state *lsp = src->fl_u.nfs4_fl.owner;
958 
959         dst->fl_u.nfs4_fl.owner = lsp;
960         refcount_inc(&lsp->ls_count);
961 }
962 
963 static void nfs4_fl_release_lock(struct file_lock *fl)
964 {
965         nfs4_put_lock_state(fl->fl_u.nfs4_fl.owner);
966 }
967 
968 static const struct file_lock_operations nfs4_fl_lock_ops = {
969         .fl_copy_lock = nfs4_fl_copy_lock,
970         .fl_release_private = nfs4_fl_release_lock,
971 };
972 
973 int nfs4_set_lock_state(struct nfs4_state *state, struct file_lock *fl)
974 {
975         struct nfs4_lock_state *lsp;
976 
977         if (fl->fl_ops != NULL)
978                 return 0;
979         lsp = nfs4_get_lock_state(state, fl->fl_owner);
980         if (lsp == NULL)
981                 return -ENOMEM;
982         fl->fl_u.nfs4_fl.owner = lsp;
983         fl->fl_ops = &nfs4_fl_lock_ops;
984         return 0;
985 }
986 
987 static int nfs4_copy_lock_stateid(nfs4_stateid *dst,
988                 struct nfs4_state *state,
989                 const struct nfs_lock_context *l_ctx)
990 {
991         struct nfs4_lock_state *lsp;
992         fl_owner_t fl_owner, fl_flock_owner;
993         int ret = -ENOENT;
994 
995         if (l_ctx == NULL)
996                 goto out;
997 
998         if (test_bit(LK_STATE_IN_USE, &state->flags) == 0)
999                 goto out;
1000 
1001         fl_owner = l_ctx->lockowner;
1002         fl_flock_owner = l_ctx->open_context->flock_owner;
1003 
1004         spin_lock(&state->state_lock);
1005         lsp = __nfs4_find_lock_state(state, fl_owner, fl_flock_owner);
1006         if (lsp && test_bit(NFS_LOCK_LOST, &lsp->ls_flags))
1007                 ret = -EIO;
1008         else if (lsp != NULL && test_bit(NFS_LOCK_INITIALIZED, &lsp->ls_flags) != 0) {
1009                 nfs4_stateid_copy(dst, &lsp->ls_stateid);
1010                 ret = 0;
1011         }
1012         spin_unlock(&state->state_lock);
1013         nfs4_put_lock_state(lsp);
1014 out:
1015         return ret;
1016 }
1017 
1018 bool nfs4_refresh_open_stateid(nfs4_stateid *dst, struct nfs4_state *state)
1019 {
1020         bool ret;
1021         int seq;
1022 
1023         do {
1024                 ret = false;
1025                 seq = read_seqbegin(&state->seqlock);
1026                 if (nfs4_state_match_open_stateid_other(state, dst)) {
1027                         dst->seqid = state->open_stateid.seqid;
1028                         ret = true;
1029                 }
1030         } while (read_seqretry(&state->seqlock, seq));
1031         return ret;
1032 }
1033 
1034 bool nfs4_copy_open_stateid(nfs4_stateid *dst, struct nfs4_state *state)
1035 {
1036         bool ret;
1037         const nfs4_stateid *src;
1038         int seq;
1039 
1040         do {
1041                 ret = false;
1042                 src = &zero_stateid;
1043                 seq = read_seqbegin(&state->seqlock);
1044                 if (test_bit(NFS_OPEN_STATE, &state->flags)) {
1045                         src = &state->open_stateid;
1046                         ret = true;
1047                 }
1048                 nfs4_stateid_copy(dst, src);
1049         } while (read_seqretry(&state->seqlock, seq));
1050         return ret;
1051 }
1052 
1053 /*
1054  * Byte-range lock aware utility to initialize the stateid of read/write
1055  * requests.
1056  */
1057 int nfs4_select_rw_stateid(struct nfs4_state *state,
1058                 fmode_t fmode, const struct nfs_lock_context *l_ctx,
1059                 nfs4_stateid *dst, const struct cred **cred)
1060 {
1061         int ret;
1062 
1063         if (!nfs4_valid_open_stateid(state))
1064                 return -EIO;
1065         if (cred != NULL)
1066                 *cred = NULL;
1067         ret = nfs4_copy_lock_stateid(dst, state, l_ctx);
1068         if (ret == -EIO)
1069                 /* A lost lock - don't even consider delegations */
1070                 goto out;
1071         /* returns true if delegation stateid found and copied */
1072         if (nfs4_copy_delegation_stateid(state->inode, fmode, dst, cred)) {
1073                 ret = 0;
1074                 goto out;
1075         }
1076         if (ret != -ENOENT)
1077                 /* nfs4_copy_delegation_stateid() didn't over-write
1078                  * dst, so it still has the lock stateid which we now
1079                  * choose to use.
1080                  */
1081                 goto out;
1082         ret = nfs4_copy_open_stateid(dst, state) ? 0 : -EAGAIN;
1083 out:
1084         if (nfs_server_capable(state->inode, NFS_CAP_STATEID_NFSV41))
1085                 dst->seqid = 0;
1086         return ret;
1087 }
1088 
1089 struct nfs_seqid *nfs_alloc_seqid(struct nfs_seqid_counter *counter, gfp_t gfp_mask)
1090 {
1091         struct nfs_seqid *new;
1092 
1093         new = kmalloc(sizeof(*new), gfp_mask);
1094         if (new == NULL)
1095                 return ERR_PTR(-ENOMEM);
1096         new->sequence = counter;
1097         INIT_LIST_HEAD(&new->list);
1098         new->task = NULL;
1099         return new;
1100 }
1101 
1102 void nfs_release_seqid(struct nfs_seqid *seqid)
1103 {
1104         struct nfs_seqid_counter *sequence;
1105 
1106         if (seqid == NULL || list_empty(&seqid->list))
1107                 return;
1108         sequence = seqid->sequence;
1109         spin_lock(&sequence->lock);
1110         list_del_init(&seqid->list);
1111         if (!list_empty(&sequence->list)) {
1112                 struct nfs_seqid *next;
1113 
1114                 next = list_first_entry(&sequence->list,
1115                                 struct nfs_seqid, list);
1116                 rpc_wake_up_queued_task(&sequence->wait, next->task);
1117         }
1118         spin_unlock(&sequence->lock);
1119 }
1120 
1121 void nfs_free_seqid(struct nfs_seqid *seqid)
1122 {
1123         nfs_release_seqid(seqid);
1124         kfree(seqid);
1125 }
1126 
1127 /*
1128  * Increment the seqid if the OPEN/OPEN_DOWNGRADE/CLOSE succeeded, or
1129  * failed with a seqid incrementing error -
1130  * see comments nfs4.h:seqid_mutating_error()
1131  */
1132 static void nfs_increment_seqid(int status, struct nfs_seqid *seqid)
1133 {
1134         switch (status) {
1135                 case 0:
1136                         break;
1137                 case -NFS4ERR_BAD_SEQID:
1138                         if (seqid->sequence->flags & NFS_SEQID_CONFIRMED)
1139                                 return;
1140                         pr_warn_ratelimited("NFS: v4 server returned a bad"
1141                                         " sequence-id error on an"
1142                                         " unconfirmed sequence %p!\n",
1143                                         seqid->sequence);
1144                 case -NFS4ERR_STALE_CLIENTID:
1145                 case -NFS4ERR_STALE_STATEID:
1146                 case -NFS4ERR_BAD_STATEID:
1147                 case -NFS4ERR_BADXDR:
1148                 case -NFS4ERR_RESOURCE:
1149                 case -NFS4ERR_NOFILEHANDLE:
1150                 case -NFS4ERR_MOVED:
1151                         /* Non-seqid mutating errors */
1152                         return;
1153         };
1154         /*
1155          * Note: no locking needed as we are guaranteed to be first
1156          * on the sequence list
1157          */
1158         seqid->sequence->counter++;
1159 }
1160 
1161 void nfs_increment_open_seqid(int status, struct nfs_seqid *seqid)
1162 {
1163         struct nfs4_state_owner *sp;
1164 
1165         if (seqid == NULL)
1166                 return;
1167 
1168         sp = container_of(seqid->sequence, struct nfs4_state_owner, so_seqid);
1169         if (status == -NFS4ERR_BAD_SEQID)
1170                 nfs4_reset_state_owner(sp);
1171         if (!nfs4_has_session(sp->so_server->nfs_client))
1172                 nfs_increment_seqid(status, seqid);
1173 }
1174 
1175 /*
1176  * Increment the seqid if the LOCK/LOCKU succeeded, or
1177  * failed with a seqid incrementing error -
1178  * see comments nfs4.h:seqid_mutating_error()
1179  */
1180 void nfs_increment_lock_seqid(int status, struct nfs_seqid *seqid)
1181 {
1182         if (seqid != NULL)
1183                 nfs_increment_seqid(status, seqid);
1184 }
1185 
1186 int nfs_wait_on_sequence(struct nfs_seqid *seqid, struct rpc_task *task)
1187 {
1188         struct nfs_seqid_counter *sequence;
1189         int status = 0;
1190 
1191         if (seqid == NULL)
1192                 goto out;
1193         sequence = seqid->sequence;
1194         spin_lock(&sequence->lock);
1195         seqid->task = task;
1196         if (list_empty(&seqid->list))
1197                 list_add_tail(&seqid->list, &sequence->list);
1198         if (list_first_entry(&sequence->list, struct nfs_seqid, list) == seqid)
1199                 goto unlock;
1200         rpc_sleep_on(&sequence->wait, task, NULL);
1201         status = -EAGAIN;
1202 unlock:
1203         spin_unlock(&sequence->lock);
1204 out:
1205         return status;
1206 }
1207 
1208 static int nfs4_run_state_manager(void *);
1209 
1210 static void nfs4_clear_state_manager_bit(struct nfs_client *clp)
1211 {
1212         smp_mb__before_atomic();
1213         clear_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state);
1214         smp_mb__after_atomic();
1215         wake_up_bit(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING);
1216         rpc_wake_up(&clp->cl_rpcwaitq);
1217 }
1218 
1219 /*
1220  * Schedule the nfs_client asynchronous state management routine
1221  */
1222 void nfs4_schedule_state_manager(struct nfs_client *clp)
1223 {
1224         struct task_struct *task;
1225         char buf[INET6_ADDRSTRLEN + sizeof("-manager") + 1];
1226 
1227         set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
1228         if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
1229                 return;
1230         __module_get(THIS_MODULE);
1231         refcount_inc(&clp->cl_count);
1232 
1233         /* The rcu_read_lock() is not strictly necessary, as the state
1234          * manager is the only thread that ever changes the rpc_xprt
1235          * after it's initialized.  At this point, we're single threaded. */
1236         rcu_read_lock();
1237         snprintf(buf, sizeof(buf), "%s-manager",
1238                         rpc_peeraddr2str(clp->cl_rpcclient, RPC_DISPLAY_ADDR));
1239         rcu_read_unlock();
1240         task = kthread_run(nfs4_run_state_manager, clp, "%s", buf);
1241         if (IS_ERR(task)) {
1242                 printk(KERN_ERR "%s: kthread_run: %ld\n",
1243                         __func__, PTR_ERR(task));
1244                 nfs4_clear_state_manager_bit(clp);
1245                 nfs_put_client(clp);
1246                 module_put(THIS_MODULE);
1247         }
1248 }
1249 
1250 /*
1251  * Schedule a lease recovery attempt
1252  */
1253 void nfs4_schedule_lease_recovery(struct nfs_client *clp)
1254 {
1255         if (!clp)
1256                 return;
1257         if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1258                 set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1259         dprintk("%s: scheduling lease recovery for server %s\n", __func__,
1260                         clp->cl_hostname);
1261         nfs4_schedule_state_manager(clp);
1262 }
1263 EXPORT_SYMBOL_GPL(nfs4_schedule_lease_recovery);
1264 
1265 /**
1266  * nfs4_schedule_migration_recovery - trigger migration recovery
1267  *
1268  * @server: FSID that is migrating
1269  *
1270  * Returns zero if recovery has started, otherwise a negative NFS4ERR
1271  * value is returned.
1272  */
1273 int nfs4_schedule_migration_recovery(const struct nfs_server *server)
1274 {
1275         struct nfs_client *clp = server->nfs_client;
1276 
1277         if (server->fh_expire_type != NFS4_FH_PERSISTENT) {
1278                 pr_err("NFS: volatile file handles not supported (server %s)\n",
1279                                 clp->cl_hostname);
1280                 return -NFS4ERR_IO;
1281         }
1282 
1283         if (test_bit(NFS_MIG_FAILED, &server->mig_status))
1284                 return -NFS4ERR_IO;
1285 
1286         dprintk("%s: scheduling migration recovery for (%llx:%llx) on %s\n",
1287                         __func__,
1288                         (unsigned long long)server->fsid.major,
1289                         (unsigned long long)server->fsid.minor,
1290                         clp->cl_hostname);
1291 
1292         set_bit(NFS_MIG_IN_TRANSITION,
1293                         &((struct nfs_server *)server)->mig_status);
1294         set_bit(NFS4CLNT_MOVED, &clp->cl_state);
1295 
1296         nfs4_schedule_state_manager(clp);
1297         return 0;
1298 }
1299 EXPORT_SYMBOL_GPL(nfs4_schedule_migration_recovery);
1300 
1301 /**
1302  * nfs4_schedule_lease_moved_recovery - start lease-moved recovery
1303  *
1304  * @clp: server to check for moved leases
1305  *
1306  */
1307 void nfs4_schedule_lease_moved_recovery(struct nfs_client *clp)
1308 {
1309         dprintk("%s: scheduling lease-moved recovery for client ID %llx on %s\n",
1310                 __func__, clp->cl_clientid, clp->cl_hostname);
1311 
1312         set_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state);
1313         nfs4_schedule_state_manager(clp);
1314 }
1315 EXPORT_SYMBOL_GPL(nfs4_schedule_lease_moved_recovery);
1316 
1317 int nfs4_wait_clnt_recover(struct nfs_client *clp)
1318 {
1319         int res;
1320 
1321         might_sleep();
1322 
1323         refcount_inc(&clp->cl_count);
1324         res = wait_on_bit_action(&clp->cl_state, NFS4CLNT_MANAGER_RUNNING,
1325                                  nfs_wait_bit_killable, TASK_KILLABLE);
1326         if (res)
1327                 goto out;
1328         if (clp->cl_cons_state < 0)
1329                 res = clp->cl_cons_state;
1330 out:
1331         nfs_put_client(clp);
1332         return res;
1333 }
1334 
1335 int nfs4_client_recover_expired_lease(struct nfs_client *clp)
1336 {
1337         unsigned int loop;
1338         int ret;
1339 
1340         for (loop = NFS4_MAX_LOOP_ON_RECOVER; loop != 0; loop--) {
1341                 ret = nfs4_wait_clnt_recover(clp);
1342                 if (ret != 0)
1343                         break;
1344                 if (!test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) &&
1345                     !test_bit(NFS4CLNT_CHECK_LEASE,&clp->cl_state))
1346                         break;
1347                 nfs4_schedule_state_manager(clp);
1348                 ret = -EIO;
1349         }
1350         return ret;
1351 }
1352 
1353 /*
1354  * nfs40_handle_cb_pathdown - return all delegations after NFS4ERR_CB_PATH_DOWN
1355  * @clp: client to process
1356  *
1357  * Set the NFS4CLNT_LEASE_EXPIRED state in order to force a
1358  * resend of the SETCLIENTID and hence re-establish the
1359  * callback channel. Then return all existing delegations.
1360  */
1361 static void nfs40_handle_cb_pathdown(struct nfs_client *clp)
1362 {
1363         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1364         nfs_expire_all_delegations(clp);
1365         dprintk("%s: handling CB_PATHDOWN recovery for server %s\n", __func__,
1366                         clp->cl_hostname);
1367 }
1368 
1369 void nfs4_schedule_path_down_recovery(struct nfs_client *clp)
1370 {
1371         nfs40_handle_cb_pathdown(clp);
1372         nfs4_schedule_state_manager(clp);
1373 }
1374 
1375 static int nfs4_state_mark_reclaim_reboot(struct nfs_client *clp, struct nfs4_state *state)
1376 {
1377 
1378         if (!nfs4_valid_open_stateid(state))
1379                 return 0;
1380         set_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1381         /* Don't recover state that expired before the reboot */
1382         if (test_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags)) {
1383                 clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1384                 return 0;
1385         }
1386         set_bit(NFS_OWNER_RECLAIM_REBOOT, &state->owner->so_flags);
1387         set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1388         return 1;
1389 }
1390 
1391 int nfs4_state_mark_reclaim_nograce(struct nfs_client *clp, struct nfs4_state *state)
1392 {
1393         if (!nfs4_valid_open_stateid(state))
1394                 return 0;
1395         set_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
1396         clear_bit(NFS_STATE_RECLAIM_REBOOT, &state->flags);
1397         set_bit(NFS_OWNER_RECLAIM_NOGRACE, &state->owner->so_flags);
1398         set_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
1399         return 1;
1400 }
1401 
1402 int nfs4_schedule_stateid_recovery(const struct nfs_server *server, struct nfs4_state *state)
1403 {
1404         struct nfs_client *clp = server->nfs_client;
1405 
1406         if (!nfs4_state_mark_reclaim_nograce(clp, state))
1407                 return -EBADF;
1408         nfs_inode_find_delegation_state_and_recover(state->inode,
1409                         &state->stateid);
1410         dprintk("%s: scheduling stateid recovery for server %s\n", __func__,
1411                         clp->cl_hostname);
1412         nfs4_schedule_state_manager(clp);
1413         return 0;
1414 }
1415 EXPORT_SYMBOL_GPL(nfs4_schedule_stateid_recovery);
1416 
1417 static struct nfs4_lock_state *
1418 nfs_state_find_lock_state_by_stateid(struct nfs4_state *state,
1419                 const nfs4_stateid *stateid)
1420 {
1421         struct nfs4_lock_state *pos;
1422 
1423         list_for_each_entry(pos, &state->lock_states, ls_locks) {
1424                 if (!test_bit(NFS_LOCK_INITIALIZED, &pos->ls_flags))
1425                         continue;
1426                 if (nfs4_stateid_match_other(&pos->ls_stateid, stateid))
1427                         return pos;
1428         }
1429         return NULL;
1430 }
1431 
1432 static bool nfs_state_lock_state_matches_stateid(struct nfs4_state *state,
1433                 const nfs4_stateid *stateid)
1434 {
1435         bool found = false;
1436 
1437         if (test_bit(LK_STATE_IN_USE, &state->flags)) {
1438                 spin_lock(&state->state_lock);
1439                 if (nfs_state_find_lock_state_by_stateid(state, stateid))
1440                         found = true;
1441                 spin_unlock(&state->state_lock);
1442         }
1443         return found;
1444 }
1445 
1446 void nfs_inode_find_state_and_recover(struct inode *inode,
1447                 const nfs4_stateid *stateid)
1448 {
1449         struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
1450         struct nfs_inode *nfsi = NFS_I(inode);
1451         struct nfs_open_context *ctx;
1452         struct nfs4_state *state;
1453         bool found = false;
1454 
1455         rcu_read_lock();
1456         list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
1457                 state = ctx->state;
1458                 if (state == NULL)
1459                         continue;
1460                 if (nfs4_stateid_match_other(&state->stateid, stateid) &&
1461                     nfs4_state_mark_reclaim_nograce(clp, state)) {
1462                         found = true;
1463                         continue;
1464                 }
1465                 if (nfs4_stateid_match_other(&state->open_stateid, stateid) &&
1466                     nfs4_state_mark_reclaim_nograce(clp, state)) {
1467                         found = true;
1468                         continue;
1469                 }
1470                 if (nfs_state_lock_state_matches_stateid(state, stateid) &&
1471                     nfs4_state_mark_reclaim_nograce(clp, state))
1472                         found = true;
1473         }
1474         rcu_read_unlock();
1475 
1476         nfs_inode_find_delegation_state_and_recover(inode, stateid);
1477         if (found)
1478                 nfs4_schedule_state_manager(clp);
1479 }
1480 
1481 static void nfs4_state_mark_open_context_bad(struct nfs4_state *state, int err)
1482 {
1483         struct inode *inode = state->inode;
1484         struct nfs_inode *nfsi = NFS_I(inode);
1485         struct nfs_open_context *ctx;
1486 
1487         rcu_read_lock();
1488         list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
1489                 if (ctx->state != state)
1490                         continue;
1491                 set_bit(NFS_CONTEXT_BAD, &ctx->flags);
1492                 pr_warn("NFSv4: state recovery failed for open file %pd2, "
1493                                 "error = %d\n", ctx->dentry, err);
1494         }
1495         rcu_read_unlock();
1496 }
1497 
1498 static void nfs4_state_mark_recovery_failed(struct nfs4_state *state, int error)
1499 {
1500         set_bit(NFS_STATE_RECOVERY_FAILED, &state->flags);
1501         nfs4_state_mark_open_context_bad(state, error);
1502 }
1503 
1504 
1505 static int nfs4_reclaim_locks(struct nfs4_state *state, const struct nfs4_state_recovery_ops *ops)
1506 {
1507         struct inode *inode = state->inode;
1508         struct nfs_inode *nfsi = NFS_I(inode);
1509         struct file_lock *fl;
1510         struct nfs4_lock_state *lsp;
1511         int status = 0;
1512         struct file_lock_context *flctx = inode->i_flctx;
1513         struct list_head *list;
1514 
1515         if (flctx == NULL)
1516                 return 0;
1517 
1518         list = &flctx->flc_posix;
1519 
1520         /* Guard against delegation returns and new lock/unlock calls */
1521         down_write(&nfsi->rwsem);
1522         spin_lock(&flctx->flc_lock);
1523 restart:
1524         list_for_each_entry(fl, list, fl_list) {
1525                 if (nfs_file_open_context(fl->fl_file)->state != state)
1526                         continue;
1527                 spin_unlock(&flctx->flc_lock);
1528                 status = ops->recover_lock(state, fl);
1529                 switch (status) {
1530                 case 0:
1531                         break;
1532                 case -ETIMEDOUT:
1533                 case -ESTALE:
1534                 case -NFS4ERR_ADMIN_REVOKED:
1535                 case -NFS4ERR_STALE_STATEID:
1536                 case -NFS4ERR_BAD_STATEID:
1537                 case -NFS4ERR_EXPIRED:
1538                 case -NFS4ERR_NO_GRACE:
1539                 case -NFS4ERR_STALE_CLIENTID:
1540                 case -NFS4ERR_BADSESSION:
1541                 case -NFS4ERR_BADSLOT:
1542                 case -NFS4ERR_BAD_HIGH_SLOT:
1543                 case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1544                         goto out;
1545                 default:
1546                         pr_err("NFS: %s: unhandled error %d\n",
1547                                         __func__, status);
1548                         /* Fall through */
1549                 case -ENOMEM:
1550                 case -NFS4ERR_DENIED:
1551                 case -NFS4ERR_RECLAIM_BAD:
1552                 case -NFS4ERR_RECLAIM_CONFLICT:
1553                         lsp = fl->fl_u.nfs4_fl.owner;
1554                         if (lsp)
1555                                 set_bit(NFS_LOCK_LOST, &lsp->ls_flags);
1556                         status = 0;
1557                 }
1558                 spin_lock(&flctx->flc_lock);
1559         }
1560         if (list == &flctx->flc_posix) {
1561                 list = &flctx->flc_flock;
1562                 goto restart;
1563         }
1564         spin_unlock(&flctx->flc_lock);
1565 out:
1566         up_write(&nfsi->rwsem);
1567         return status;
1568 }
1569 
1570 #ifdef CONFIG_NFS_V4_2
1571 static void nfs42_complete_copies(struct nfs4_state_owner *sp, struct nfs4_state *state)
1572 {
1573         struct nfs4_copy_state *copy;
1574 
1575         if (!test_bit(NFS_CLNT_DST_SSC_COPY_STATE, &state->flags))
1576                 return;
1577 
1578         spin_lock(&sp->so_server->nfs_client->cl_lock);
1579         list_for_each_entry(copy, &sp->so_server->ss_copies, copies) {
1580                 if (!nfs4_stateid_match_other(&state->stateid, &copy->parent_state->stateid))
1581                         continue;
1582                 copy->flags = 1;
1583                 complete(&copy->completion);
1584                 break;
1585         }
1586         spin_unlock(&sp->so_server->nfs_client->cl_lock);
1587 }
1588 #else /* !CONFIG_NFS_V4_2 */
1589 static inline void nfs42_complete_copies(struct nfs4_state_owner *sp,
1590                                          struct nfs4_state *state)
1591 {
1592 }
1593 #endif /* CONFIG_NFS_V4_2 */
1594 
1595 static int __nfs4_reclaim_open_state(struct nfs4_state_owner *sp, struct nfs4_state *state,
1596                                      const struct nfs4_state_recovery_ops *ops)
1597 {
1598         struct nfs4_lock_state *lock;
1599         int status;
1600 
1601         status = ops->recover_open(sp, state);
1602         if (status < 0)
1603                 return status;
1604 
1605         status = nfs4_reclaim_locks(state, ops);
1606         if (status < 0)
1607                 return status;
1608 
1609         if (!test_bit(NFS_DELEGATED_STATE, &state->flags)) {
1610                 spin_lock(&state->state_lock);
1611                 list_for_each_entry(lock, &state->lock_states, ls_locks) {
1612                         if (!test_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags))
1613                                 pr_warn_ratelimited("NFS: %s: Lock reclaim failed!\n", __func__);
1614                 }
1615                 spin_unlock(&state->state_lock);
1616         }
1617 
1618         nfs42_complete_copies(sp, state);
1619         clear_bit(NFS_STATE_RECLAIM_NOGRACE, &state->flags);
1620         return status;
1621 }
1622 
1623 static int nfs4_reclaim_open_state(struct nfs4_state_owner *sp, const struct nfs4_state_recovery_ops *ops)
1624 {
1625         struct nfs4_state *state;
1626         unsigned int loop = 0;
1627         int status = 0;
1628 
1629         /* Note: we rely on the sp->so_states list being ordered 
1630          * so that we always reclaim open(O_RDWR) and/or open(O_WRITE)
1631          * states first.
1632          * This is needed to ensure that the server won't give us any
1633          * read delegations that we have to return if, say, we are
1634          * recovering after a network partition or a reboot from a
1635          * server that doesn't support a grace period.
1636          */
1637         spin_lock(&sp->so_lock);
1638         raw_write_seqcount_begin(&sp->so_reclaim_seqcount);
1639 restart:
1640         list_for_each_entry(state, &sp->so_states, open_states) {
1641                 if (!test_and_clear_bit(ops->state_flag_bit, &state->flags))
1642                         continue;
1643                 if (!nfs4_valid_open_stateid(state))
1644                         continue;
1645                 if (state->state == 0)
1646                         continue;
1647                 refcount_inc(&state->count);
1648                 spin_unlock(&sp->so_lock);
1649                 status = __nfs4_reclaim_open_state(sp, state, ops);
1650 
1651                 switch (status) {
1652                 default:
1653                         if (status >= 0) {
1654                                 loop = 0;
1655                                 break;
1656                         }
1657                         printk(KERN_ERR "NFS: %s: unhandled error %d\n", __func__, status);
1658                         /* Fall through */
1659                 case -ENOENT:
1660                 case -ENOMEM:
1661                 case -EACCES:
1662                 case -EROFS:
1663                 case -EIO:
1664                 case -ESTALE:
1665                         /* Open state on this file cannot be recovered */
1666                         nfs4_state_mark_recovery_failed(state, status);
1667                         break;
1668                 case -EAGAIN:
1669                         ssleep(1);
1670                         if (loop++ < 10) {
1671                                 set_bit(ops->state_flag_bit, &state->flags);
1672                                 break;
1673                         }
1674                         /* Fall through */
1675                 case -NFS4ERR_ADMIN_REVOKED:
1676                 case -NFS4ERR_STALE_STATEID:
1677                 case -NFS4ERR_OLD_STATEID:
1678                 case -NFS4ERR_BAD_STATEID:
1679                 case -NFS4ERR_RECLAIM_BAD:
1680                 case -NFS4ERR_RECLAIM_CONFLICT:
1681                         nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1682                         break;
1683                 case -NFS4ERR_EXPIRED:
1684                 case -NFS4ERR_NO_GRACE:
1685                         nfs4_state_mark_reclaim_nograce(sp->so_server->nfs_client, state);
1686                         /* Fall through */
1687                 case -NFS4ERR_STALE_CLIENTID:
1688                 case -NFS4ERR_BADSESSION:
1689                 case -NFS4ERR_BADSLOT:
1690                 case -NFS4ERR_BAD_HIGH_SLOT:
1691                 case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1692                 case -ETIMEDOUT:
1693                         goto out_err;
1694                 }
1695                 nfs4_put_open_state(state);
1696                 spin_lock(&sp->so_lock);
1697                 goto restart;
1698         }
1699         raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1700         spin_unlock(&sp->so_lock);
1701         return 0;
1702 out_err:
1703         nfs4_put_open_state(state);
1704         spin_lock(&sp->so_lock);
1705         raw_write_seqcount_end(&sp->so_reclaim_seqcount);
1706         spin_unlock(&sp->so_lock);
1707         return status;
1708 }
1709 
1710 static void nfs4_clear_open_state(struct nfs4_state *state)
1711 {
1712         struct nfs4_lock_state *lock;
1713 
1714         clear_bit(NFS_DELEGATED_STATE, &state->flags);
1715         clear_bit(NFS_O_RDONLY_STATE, &state->flags);
1716         clear_bit(NFS_O_WRONLY_STATE, &state->flags);
1717         clear_bit(NFS_O_RDWR_STATE, &state->flags);
1718         spin_lock(&state->state_lock);
1719         list_for_each_entry(lock, &state->lock_states, ls_locks) {
1720                 lock->ls_seqid.flags = 0;
1721                 clear_bit(NFS_LOCK_INITIALIZED, &lock->ls_flags);
1722         }
1723         spin_unlock(&state->state_lock);
1724 }
1725 
1726 static void nfs4_reset_seqids(struct nfs_server *server,
1727         int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1728 {
1729         struct nfs_client *clp = server->nfs_client;
1730         struct nfs4_state_owner *sp;
1731         struct rb_node *pos;
1732         struct nfs4_state *state;
1733 
1734         spin_lock(&clp->cl_lock);
1735         for (pos = rb_first(&server->state_owners);
1736              pos != NULL;
1737              pos = rb_next(pos)) {
1738                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1739                 sp->so_seqid.flags = 0;
1740                 spin_lock(&sp->so_lock);
1741                 list_for_each_entry(state, &sp->so_states, open_states) {
1742                         if (mark_reclaim(clp, state))
1743                                 nfs4_clear_open_state(state);
1744                 }
1745                 spin_unlock(&sp->so_lock);
1746         }
1747         spin_unlock(&clp->cl_lock);
1748 }
1749 
1750 static void nfs4_state_mark_reclaim_helper(struct nfs_client *clp,
1751         int (*mark_reclaim)(struct nfs_client *clp, struct nfs4_state *state))
1752 {
1753         struct nfs_server *server;
1754 
1755         rcu_read_lock();
1756         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1757                 nfs4_reset_seqids(server, mark_reclaim);
1758         rcu_read_unlock();
1759 }
1760 
1761 static void nfs4_state_start_reclaim_reboot(struct nfs_client *clp)
1762 {
1763         /* Mark all delegations for reclaim */
1764         nfs_delegation_mark_reclaim(clp);
1765         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_reboot);
1766 }
1767 
1768 static int nfs4_reclaim_complete(struct nfs_client *clp,
1769                                  const struct nfs4_state_recovery_ops *ops,
1770                                  const struct cred *cred)
1771 {
1772         /* Notify the server we're done reclaiming our state */
1773         if (ops->reclaim_complete)
1774                 return ops->reclaim_complete(clp, cred);
1775         return 0;
1776 }
1777 
1778 static void nfs4_clear_reclaim_server(struct nfs_server *server)
1779 {
1780         struct nfs_client *clp = server->nfs_client;
1781         struct nfs4_state_owner *sp;
1782         struct rb_node *pos;
1783         struct nfs4_state *state;
1784 
1785         spin_lock(&clp->cl_lock);
1786         for (pos = rb_first(&server->state_owners);
1787              pos != NULL;
1788              pos = rb_next(pos)) {
1789                 sp = rb_entry(pos, struct nfs4_state_owner, so_server_node);
1790                 spin_lock(&sp->so_lock);
1791                 list_for_each_entry(state, &sp->so_states, open_states) {
1792                         if (!test_and_clear_bit(NFS_STATE_RECLAIM_REBOOT,
1793                                                 &state->flags))
1794                                 continue;
1795                         nfs4_state_mark_reclaim_nograce(clp, state);
1796                 }
1797                 spin_unlock(&sp->so_lock);
1798         }
1799         spin_unlock(&clp->cl_lock);
1800 }
1801 
1802 static int nfs4_state_clear_reclaim_reboot(struct nfs_client *clp)
1803 {
1804         struct nfs_server *server;
1805 
1806         if (!test_and_clear_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state))
1807                 return 0;
1808 
1809         rcu_read_lock();
1810         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1811                 nfs4_clear_reclaim_server(server);
1812         rcu_read_unlock();
1813 
1814         nfs_delegation_reap_unclaimed(clp);
1815         return 1;
1816 }
1817 
1818 static void nfs4_state_end_reclaim_reboot(struct nfs_client *clp)
1819 {
1820         const struct nfs4_state_recovery_ops *ops;
1821         const struct cred *cred;
1822         int err;
1823 
1824         if (!nfs4_state_clear_reclaim_reboot(clp))
1825                 return;
1826         ops = clp->cl_mvops->reboot_recovery_ops;
1827         cred = nfs4_get_clid_cred(clp);
1828         err = nfs4_reclaim_complete(clp, ops, cred);
1829         put_cred(cred);
1830         if (err == -NFS4ERR_CONN_NOT_BOUND_TO_SESSION)
1831                 set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
1832 }
1833 
1834 static void nfs4_state_start_reclaim_nograce(struct nfs_client *clp)
1835 {
1836         nfs_mark_test_expired_all_delegations(clp);
1837         nfs4_state_mark_reclaim_helper(clp, nfs4_state_mark_reclaim_nograce);
1838 }
1839 
1840 static int nfs4_recovery_handle_error(struct nfs_client *clp, int error)
1841 {
1842         switch (error) {
1843         case 0:
1844                 break;
1845         case -NFS4ERR_CB_PATH_DOWN:
1846                 nfs40_handle_cb_pathdown(clp);
1847                 break;
1848         case -NFS4ERR_NO_GRACE:
1849                 nfs4_state_end_reclaim_reboot(clp);
1850                 break;
1851         case -NFS4ERR_STALE_CLIENTID:
1852                 set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1853                 nfs4_state_start_reclaim_reboot(clp);
1854                 break;
1855         case -NFS4ERR_EXPIRED:
1856                 set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1857                 nfs4_state_start_reclaim_nograce(clp);
1858                 break;
1859         case -NFS4ERR_BADSESSION:
1860         case -NFS4ERR_BADSLOT:
1861         case -NFS4ERR_BAD_HIGH_SLOT:
1862         case -NFS4ERR_DEADSESSION:
1863         case -NFS4ERR_SEQ_FALSE_RETRY:
1864         case -NFS4ERR_SEQ_MISORDERED:
1865                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
1866                 /* Zero session reset errors */
1867                 break;
1868         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
1869                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
1870                 break;
1871         default:
1872                 dprintk("%s: failed to handle error %d for server %s\n",
1873                                 __func__, error, clp->cl_hostname);
1874                 return error;
1875         }
1876         dprintk("%s: handled error %d for server %s\n", __func__, error,
1877                         clp->cl_hostname);
1878         return 0;
1879 }
1880 
1881 static int nfs4_do_reclaim(struct nfs_client *clp, const struct nfs4_state_recovery_ops *ops)
1882 {
1883         struct nfs4_state_owner *sp;
1884         struct nfs_server *server;
1885         struct rb_node *pos;
1886         LIST_HEAD(freeme);
1887         int status = 0;
1888 
1889 restart:
1890         rcu_read_lock();
1891         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
1892                 nfs4_purge_state_owners(server, &freeme);
1893                 spin_lock(&clp->cl_lock);
1894                 for (pos = rb_first(&server->state_owners);
1895                      pos != NULL;
1896                      pos = rb_next(pos)) {
1897                         sp = rb_entry(pos,
1898                                 struct nfs4_state_owner, so_server_node);
1899                         if (!test_and_clear_bit(ops->owner_flag_bit,
1900                                                         &sp->so_flags))
1901                                 continue;
1902                         if (!atomic_inc_not_zero(&sp->so_count))
1903                                 continue;
1904                         spin_unlock(&clp->cl_lock);
1905                         rcu_read_unlock();
1906 
1907                         status = nfs4_reclaim_open_state(sp, ops);
1908                         if (status < 0) {
1909                                 set_bit(ops->owner_flag_bit, &sp->so_flags);
1910                                 nfs4_put_state_owner(sp);
1911                                 status = nfs4_recovery_handle_error(clp, status);
1912                                 return (status != 0) ? status : -EAGAIN;
1913                         }
1914 
1915                         nfs4_put_state_owner(sp);
1916                         goto restart;
1917                 }
1918                 spin_unlock(&clp->cl_lock);
1919         }
1920         rcu_read_unlock();
1921         nfs4_free_state_owners(&freeme);
1922         return 0;
1923 }
1924 
1925 static int nfs4_check_lease(struct nfs_client *clp)
1926 {
1927         const struct cred *cred;
1928         const struct nfs4_state_maintenance_ops *ops =
1929                 clp->cl_mvops->state_renewal_ops;
1930         int status;
1931 
1932         /* Is the client already known to have an expired lease? */
1933         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
1934                 return 0;
1935         cred = ops->get_state_renewal_cred(clp);
1936         if (cred == NULL) {
1937                 cred = nfs4_get_clid_cred(clp);
1938                 status = -ENOKEY;
1939                 if (cred == NULL)
1940                         goto out;
1941         }
1942         status = ops->renew_lease(clp, cred);
1943         put_cred(cred);
1944         if (status == -ETIMEDOUT) {
1945                 set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
1946                 return 0;
1947         }
1948 out:
1949         return nfs4_recovery_handle_error(clp, status);
1950 }
1951 
1952 /* Set NFS4CLNT_LEASE_EXPIRED and reclaim reboot state for all v4.0 errors
1953  * and for recoverable errors on EXCHANGE_ID for v4.1
1954  */
1955 static int nfs4_handle_reclaim_lease_error(struct nfs_client *clp, int status)
1956 {
1957         switch (status) {
1958         case -NFS4ERR_SEQ_MISORDERED:
1959                 if (test_and_set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state))
1960                         return -ESERVERFAULT;
1961                 /* Lease confirmation error: retry after purging the lease */
1962                 ssleep(1);
1963                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1964                 break;
1965         case -NFS4ERR_STALE_CLIENTID:
1966                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1967                 nfs4_state_start_reclaim_reboot(clp);
1968                 break;
1969         case -NFS4ERR_CLID_INUSE:
1970                 pr_err("NFS: Server %s reports our clientid is in use\n",
1971                         clp->cl_hostname);
1972                 nfs_mark_client_ready(clp, -EPERM);
1973                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
1974                 return -EPERM;
1975         case -EACCES:
1976         case -NFS4ERR_DELAY:
1977         case -EAGAIN:
1978                 ssleep(1);
1979                 break;
1980 
1981         case -NFS4ERR_MINOR_VERS_MISMATCH:
1982                 if (clp->cl_cons_state == NFS_CS_SESSION_INITING)
1983                         nfs_mark_client_ready(clp, -EPROTONOSUPPORT);
1984                 dprintk("%s: exit with error %d for server %s\n",
1985                                 __func__, -EPROTONOSUPPORT, clp->cl_hostname);
1986                 return -EPROTONOSUPPORT;
1987         case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
1988                                  * in nfs4_exchange_id */
1989         default:
1990                 dprintk("%s: exit with error %d for server %s\n", __func__,
1991                                 status, clp->cl_hostname);
1992                 return status;
1993         }
1994         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
1995         dprintk("%s: handled error %d for server %s\n", __func__, status,
1996                         clp->cl_hostname);
1997         return 0;
1998 }
1999 
2000 static int nfs4_establish_lease(struct nfs_client *clp)
2001 {
2002         const struct cred *cred;
2003         const struct nfs4_state_recovery_ops *ops =
2004                 clp->cl_mvops->reboot_recovery_ops;
2005         int status;
2006 
2007         status = nfs4_begin_drain_session(clp);
2008         if (status != 0)
2009                 return status;
2010         cred = nfs4_get_clid_cred(clp);
2011         if (cred == NULL)
2012                 return -ENOENT;
2013         status = ops->establish_clid(clp, cred);
2014         put_cred(cred);
2015         if (status != 0)
2016                 return status;
2017         pnfs_destroy_all_layouts(clp);
2018         return 0;
2019 }
2020 
2021 /*
2022  * Returns zero or a negative errno.  NFS4ERR values are converted
2023  * to local errno values.
2024  */
2025 static int nfs4_reclaim_lease(struct nfs_client *clp)
2026 {
2027         int status;
2028 
2029         status = nfs4_establish_lease(clp);
2030         if (status < 0)
2031                 return nfs4_handle_reclaim_lease_error(clp, status);
2032         if (test_and_clear_bit(NFS4CLNT_SERVER_SCOPE_MISMATCH, &clp->cl_state))
2033                 nfs4_state_start_reclaim_nograce(clp);
2034         if (!test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state))
2035                 set_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state);
2036         clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
2037         clear_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
2038         return 0;
2039 }
2040 
2041 static int nfs4_purge_lease(struct nfs_client *clp)
2042 {
2043         int status;
2044 
2045         status = nfs4_establish_lease(clp);
2046         if (status < 0)
2047                 return nfs4_handle_reclaim_lease_error(clp, status);
2048         clear_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
2049         set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state);
2050         nfs4_state_start_reclaim_nograce(clp);
2051         return 0;
2052 }
2053 
2054 /*
2055  * Try remote migration of one FSID from a source server to a
2056  * destination server.  The source server provides a list of
2057  * potential destinations.
2058  *
2059  * Returns zero or a negative NFS4ERR status code.
2060  */
2061 static int nfs4_try_migration(struct nfs_server *server, const struct cred *cred)
2062 {
2063         struct nfs_client *clp = server->nfs_client;
2064         struct nfs4_fs_locations *locations = NULL;
2065         struct inode *inode;
2066         struct page *page;
2067         int status, result;
2068 
2069         dprintk("--> %s: FSID %llx:%llx on \"%s\"\n", __func__,
2070                         (unsigned long long)server->fsid.major,
2071                         (unsigned long long)server->fsid.minor,
2072                         clp->cl_hostname);
2073 
2074         result = 0;
2075         page = alloc_page(GFP_KERNEL);
2076         locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
2077         if (page == NULL || locations == NULL) {
2078                 dprintk("<-- %s: no memory\n", __func__);
2079                 goto out;
2080         }
2081 
2082         inode = d_inode(server->super->s_root);
2083         result = nfs4_proc_get_locations(inode, locations, page, cred);
2084         if (result) {
2085                 dprintk("<-- %s: failed to retrieve fs_locations: %d\n",
2086                         __func__, result);
2087                 goto out;
2088         }
2089 
2090         result = -NFS4ERR_NXIO;
2091         if (!(locations->fattr.valid & NFS_ATTR_FATTR_V4_LOCATIONS)) {
2092                 dprintk("<-- %s: No fs_locations data, migration skipped\n",
2093                         __func__);
2094                 goto out;
2095         }
2096 
2097         status = nfs4_begin_drain_session(clp);
2098         if (status != 0)
2099                 return status;
2100 
2101         status = nfs4_replace_transport(server, locations);
2102         if (status != 0) {
2103                 dprintk("<-- %s: failed to replace transport: %d\n",
2104                         __func__, status);
2105                 goto out;
2106         }
2107 
2108         result = 0;
2109         dprintk("<-- %s: migration succeeded\n", __func__);
2110 
2111 out:
2112         if (page != NULL)
2113                 __free_page(page);
2114         kfree(locations);
2115         if (result) {
2116                 pr_err("NFS: migration recovery failed (server %s)\n",
2117                                 clp->cl_hostname);
2118                 set_bit(NFS_MIG_FAILED, &server->mig_status);
2119         }
2120         return result;
2121 }
2122 
2123 /*
2124  * Returns zero or a negative NFS4ERR status code.
2125  */
2126 static int nfs4_handle_migration(struct nfs_client *clp)
2127 {
2128         const struct nfs4_state_maintenance_ops *ops =
2129                                 clp->cl_mvops->state_renewal_ops;
2130         struct nfs_server *server;
2131         const struct cred *cred;
2132 
2133         dprintk("%s: migration reported on \"%s\"\n", __func__,
2134                         clp->cl_hostname);
2135 
2136         cred = ops->get_state_renewal_cred(clp);
2137         if (cred == NULL)
2138                 return -NFS4ERR_NOENT;
2139 
2140         clp->cl_mig_gen++;
2141 restart:
2142         rcu_read_lock();
2143         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
2144                 int status;
2145 
2146                 if (server->mig_gen == clp->cl_mig_gen)
2147                         continue;
2148                 server->mig_gen = clp->cl_mig_gen;
2149 
2150                 if (!test_and_clear_bit(NFS_MIG_IN_TRANSITION,
2151                                                 &server->mig_status))
2152                         continue;
2153 
2154                 rcu_read_unlock();
2155                 status = nfs4_try_migration(server, cred);
2156                 if (status < 0) {
2157                         put_cred(cred);
2158                         return status;
2159                 }
2160                 goto restart;
2161         }
2162         rcu_read_unlock();
2163         put_cred(cred);
2164         return 0;
2165 }
2166 
2167 /*
2168  * Test each nfs_server on the clp's cl_superblocks list to see
2169  * if it's moved to another server.  Stop when the server no longer
2170  * returns NFS4ERR_LEASE_MOVED.
2171  */
2172 static int nfs4_handle_lease_moved(struct nfs_client *clp)
2173 {
2174         const struct nfs4_state_maintenance_ops *ops =
2175                                 clp->cl_mvops->state_renewal_ops;
2176         struct nfs_server *server;
2177         const struct cred *cred;
2178 
2179         dprintk("%s: lease moved reported on \"%s\"\n", __func__,
2180                         clp->cl_hostname);
2181 
2182         cred = ops->get_state_renewal_cred(clp);
2183         if (cred == NULL)
2184                 return -NFS4ERR_NOENT;
2185 
2186         clp->cl_mig_gen++;
2187 restart:
2188         rcu_read_lock();
2189         list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
2190                 struct inode *inode;
2191                 int status;
2192 
2193                 if (server->mig_gen == clp->cl_mig_gen)
2194                         continue;
2195                 server->mig_gen = clp->cl_mig_gen;
2196 
2197                 rcu_read_unlock();
2198 
2199                 inode = d_inode(server->super->s_root);
2200                 status = nfs4_proc_fsid_present(inode, cred);
2201                 if (status != -NFS4ERR_MOVED)
2202                         goto restart;   /* wasn't this one */
2203                 if (nfs4_try_migration(server, cred) == -NFS4ERR_LEASE_MOVED)
2204                         goto restart;   /* there are more */
2205                 goto out;
2206         }
2207         rcu_read_unlock();
2208 
2209 out:
2210         put_cred(cred);
2211         return 0;
2212 }
2213 
2214 /**
2215  * nfs4_discover_server_trunking - Detect server IP address trunking
2216  *
2217  * @clp: nfs_client under test
2218  * @result: OUT: found nfs_client, or clp
2219  *
2220  * Returns zero or a negative errno.  If zero is returned,
2221  * an nfs_client pointer is planted in "result".
2222  *
2223  * Note: since we are invoked in process context, and
2224  * not from inside the state manager, we cannot use
2225  * nfs4_handle_reclaim_lease_error().
2226  */
2227 int nfs4_discover_server_trunking(struct nfs_client *clp,
2228                                   struct nfs_client **result)
2229 {
2230         const struct nfs4_state_recovery_ops *ops =
2231                                 clp->cl_mvops->reboot_recovery_ops;
2232         struct rpc_clnt *clnt;
2233         const struct cred *cred;
2234         int i, status;
2235 
2236         dprintk("NFS: %s: testing '%s'\n", __func__, clp->cl_hostname);
2237 
2238         clnt = clp->cl_rpcclient;
2239         i = 0;
2240 
2241         mutex_lock(&nfs_clid_init_mutex);
2242 again:
2243         status  = -ENOENT;
2244         cred = nfs4_get_clid_cred(clp);
2245         if (cred == NULL)
2246                 goto out_unlock;
2247 
2248         status = ops->detect_trunking(clp, result, cred);
2249         put_cred(cred);
2250         switch (status) {
2251         case 0:
2252         case -EINTR:
2253         case -ERESTARTSYS:
2254                 break;
2255         case -ETIMEDOUT:
2256                 if (clnt->cl_softrtry)
2257                         break;
2258                 /* Fall through */
2259         case -NFS4ERR_DELAY:
2260         case -EAGAIN:
2261                 ssleep(1);
2262                 /* Fall through */
2263         case -NFS4ERR_STALE_CLIENTID:
2264                 dprintk("NFS: %s after status %d, retrying\n",
2265                         __func__, status);
2266                 goto again;
2267         case -EACCES:
2268                 if (i++ == 0) {
2269                         nfs4_root_machine_cred(clp);
2270                         goto again;
2271                 }
2272                 if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX)
2273                         break;
2274                 /* Fall through */
2275         case -NFS4ERR_CLID_INUSE:
2276         case -NFS4ERR_WRONGSEC:
2277                 /* No point in retrying if we already used RPC_AUTH_UNIX */
2278                 if (clnt->cl_auth->au_flavor == RPC_AUTH_UNIX) {
2279                         status = -EPERM;
2280                         break;
2281                 }
2282                 clnt = rpc_clone_client_set_auth(clnt, RPC_AUTH_UNIX);
2283                 if (IS_ERR(clnt)) {
2284                         status = PTR_ERR(clnt);
2285                         break;
2286                 }
2287                 /* Note: this is safe because we haven't yet marked the
2288                  * client as ready, so we are the only user of
2289                  * clp->cl_rpcclient
2290                  */
2291                 clnt = xchg(&clp->cl_rpcclient, clnt);
2292                 rpc_shutdown_client(clnt);
2293                 clnt = clp->cl_rpcclient;
2294                 goto again;
2295 
2296         case -NFS4ERR_MINOR_VERS_MISMATCH:
2297                 status = -EPROTONOSUPPORT;
2298                 break;
2299 
2300         case -EKEYEXPIRED:
2301         case -NFS4ERR_NOT_SAME: /* FixMe: implement recovery
2302                                  * in nfs4_exchange_id */
2303                 status = -EKEYEXPIRED;
2304                 break;
2305         default:
2306                 pr_warn("NFS: %s unhandled error %d. Exiting with error EIO\n",
2307                                 __func__, status);
2308                 status = -EIO;
2309         }
2310 
2311 out_unlock:
2312         mutex_unlock(&nfs_clid_init_mutex);
2313         dprintk("NFS: %s: status = %d\n", __func__, status);
2314         return status;
2315 }
2316 
2317 #ifdef CONFIG_NFS_V4_1
2318 void nfs4_schedule_session_recovery(struct nfs4_session *session, int err)
2319 {
2320         struct nfs_client *clp = session->clp;
2321 
2322         switch (err) {
2323         default:
2324                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2325                 break;
2326         case -NFS4ERR_CONN_NOT_BOUND_TO_SESSION:
2327                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2328         }
2329         nfs4_schedule_state_manager(clp);
2330 }
2331 EXPORT_SYMBOL_GPL(nfs4_schedule_session_recovery);
2332 
2333 void nfs41_notify_server(struct nfs_client *clp)
2334 {
2335         /* Use CHECK_LEASE to ping the server with a SEQUENCE */
2336         set_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state);
2337         nfs4_schedule_state_manager(clp);
2338 }
2339 
2340 static void nfs4_reset_all_state(struct nfs_client *clp)
2341 {
2342         if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2343                 set_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state);
2344                 clear_bit(NFS4CLNT_LEASE_CONFIRM, &clp->cl_state);
2345                 nfs4_state_start_reclaim_nograce(clp);
2346                 dprintk("%s: scheduling reset of all state for server %s!\n",
2347                                 __func__, clp->cl_hostname);
2348                 nfs4_schedule_state_manager(clp);
2349         }
2350 }
2351 
2352 static void nfs41_handle_server_reboot(struct nfs_client *clp)
2353 {
2354         if (test_and_set_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state) == 0) {
2355                 nfs4_state_start_reclaim_reboot(clp);
2356                 dprintk("%s: server %s rebooted!\n", __func__,
2357                                 clp->cl_hostname);
2358                 nfs4_schedule_state_manager(clp);
2359         }
2360 }
2361 
2362 static void nfs41_handle_all_state_revoked(struct nfs_client *clp)
2363 {
2364         nfs4_reset_all_state(clp);
2365         dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2366 }
2367 
2368 static void nfs41_handle_some_state_revoked(struct nfs_client *clp)
2369 {
2370         nfs4_state_start_reclaim_nograce(clp);
2371         nfs4_schedule_state_manager(clp);
2372 
2373         dprintk("%s: state revoked on server %s\n", __func__, clp->cl_hostname);
2374 }
2375 
2376 static void nfs41_handle_recallable_state_revoked(struct nfs_client *clp)
2377 {
2378         /* FIXME: For now, we destroy all layouts. */
2379         pnfs_destroy_all_layouts(clp);
2380         nfs_test_expired_all_delegations(clp);
2381         dprintk("%s: Recallable state revoked on server %s!\n", __func__,
2382                         clp->cl_hostname);
2383 }
2384 
2385 static void nfs41_handle_backchannel_fault(struct nfs_client *clp)
2386 {
2387         set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2388         nfs4_schedule_state_manager(clp);
2389 
2390         dprintk("%s: server %s declared a backchannel fault\n", __func__,
2391                         clp->cl_hostname);
2392 }
2393 
2394 static void nfs41_handle_cb_path_down(struct nfs_client *clp)
2395 {
2396         if (test_and_set_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2397                 &clp->cl_state) == 0)
2398                 nfs4_schedule_state_manager(clp);
2399 }
2400 
2401 void nfs41_handle_sequence_flag_errors(struct nfs_client *clp, u32 flags,
2402                 bool recovery)
2403 {
2404         if (!flags)
2405                 return;
2406 
2407         dprintk("%s: \"%s\" (client ID %llx) flags=0x%08x\n",
2408                 __func__, clp->cl_hostname, clp->cl_clientid, flags);
2409         /*
2410          * If we're called from the state manager thread, then assume we're
2411          * already handling the RECLAIM_NEEDED and/or STATE_REVOKED.
2412          * Those flags are expected to remain set until we're done
2413          * recovering (see RFC5661, section 18.46.3).
2414          */
2415         if (recovery)
2416                 goto out_recovery;
2417 
2418         if (flags & SEQ4_STATUS_RESTART_RECLAIM_NEEDED)
2419                 nfs41_handle_server_reboot(clp);
2420         if (flags & (SEQ4_STATUS_EXPIRED_ALL_STATE_REVOKED))
2421                 nfs41_handle_all_state_revoked(clp);
2422         if (flags & (SEQ4_STATUS_EXPIRED_SOME_STATE_REVOKED |
2423                             SEQ4_STATUS_ADMIN_STATE_REVOKED))
2424                 nfs41_handle_some_state_revoked(clp);
2425         if (flags & SEQ4_STATUS_LEASE_MOVED)
2426                 nfs4_schedule_lease_moved_recovery(clp);
2427         if (flags & SEQ4_STATUS_RECALLABLE_STATE_REVOKED)
2428                 nfs41_handle_recallable_state_revoked(clp);
2429 out_recovery:
2430         if (flags & SEQ4_STATUS_BACKCHANNEL_FAULT)
2431                 nfs41_handle_backchannel_fault(clp);
2432         else if (flags & (SEQ4_STATUS_CB_PATH_DOWN |
2433                                 SEQ4_STATUS_CB_PATH_DOWN_SESSION))
2434                 nfs41_handle_cb_path_down(clp);
2435 }
2436 
2437 static int nfs4_reset_session(struct nfs_client *clp)
2438 {
2439         const struct cred *cred;
2440         int status;
2441 
2442         if (!nfs4_has_session(clp))
2443                 return 0;
2444         status = nfs4_begin_drain_session(clp);
2445         if (status != 0)
2446                 return status;
2447         cred = nfs4_get_clid_cred(clp);
2448         status = nfs4_proc_destroy_session(clp->cl_session, cred);
2449         switch (status) {
2450         case 0:
2451         case -NFS4ERR_BADSESSION:
2452         case -NFS4ERR_DEADSESSION:
2453                 break;
2454         case -NFS4ERR_BACK_CHAN_BUSY:
2455         case -NFS4ERR_DELAY:
2456                 set_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state);
2457                 status = 0;
2458                 ssleep(1);
2459                 goto out;
2460         default:
2461                 status = nfs4_recovery_handle_error(clp, status);
2462                 goto out;
2463         }
2464 
2465         memset(clp->cl_session->sess_id.data, 0, NFS4_MAX_SESSIONID_LEN);
2466         status = nfs4_proc_create_session(clp, cred);
2467         if (status) {
2468                 dprintk("%s: session reset failed with status %d for server %s!\n",
2469                         __func__, status, clp->cl_hostname);
2470                 status = nfs4_handle_reclaim_lease_error(clp, status);
2471                 goto out;
2472         }
2473         nfs41_finish_session_reset(clp);
2474         dprintk("%s: session reset was successful for server %s!\n",
2475                         __func__, clp->cl_hostname);
2476 out:
2477         put_cred(cred);
2478         return status;
2479 }
2480 
2481 static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2482 {
2483         const struct cred *cred;
2484         int ret;
2485 
2486         if (!nfs4_has_session(clp))
2487                 return 0;
2488         ret = nfs4_begin_drain_session(clp);
2489         if (ret != 0)
2490                 return ret;
2491         cred = nfs4_get_clid_cred(clp);
2492         ret = nfs4_proc_bind_conn_to_session(clp, cred);
2493         put_cred(cred);
2494         clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2495         switch (ret) {
2496         case 0:
2497                 dprintk("%s: bind_conn_to_session was successful for server %s!\n",
2498                         __func__, clp->cl_hostname);
2499                 break;
2500         case -NFS4ERR_DELAY:
2501                 ssleep(1);
2502                 set_bit(NFS4CLNT_BIND_CONN_TO_SESSION, &clp->cl_state);
2503                 break;
2504         default:
2505                 return nfs4_recovery_handle_error(clp, ret);
2506         }
2507         return 0;
2508 }
2509 #else /* CONFIG_NFS_V4_1 */
2510 static int nfs4_reset_session(struct nfs_client *clp) { return 0; }
2511 
2512 static int nfs4_bind_conn_to_session(struct nfs_client *clp)
2513 {
2514         return 0;
2515 }
2516 #endif /* CONFIG_NFS_V4_1 */
2517 
2518 static void nfs4_state_manager(struct nfs_client *clp)
2519 {
2520         int status = 0;
2521         const char *section = "", *section_sep = "";
2522 
2523         /* Ensure exclusive access to NFSv4 state */
2524         do {
2525                 clear_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
2526                 if (test_bit(NFS4CLNT_PURGE_STATE, &clp->cl_state)) {
2527                         section = "purge state";
2528                         status = nfs4_purge_lease(clp);
2529                         if (status < 0)
2530                                 goto out_error;
2531                         continue;
2532                 }
2533 
2534                 if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state)) {
2535                         section = "lease expired";
2536                         /* We're going to have to re-establish a clientid */
2537                         status = nfs4_reclaim_lease(clp);
2538                         if (status < 0)
2539                                 goto out_error;
2540                         continue;
2541                 }
2542 
2543                 /* Initialize or reset the session */
2544                 if (test_and_clear_bit(NFS4CLNT_SESSION_RESET, &clp->cl_state)) {
2545                         section = "reset session";
2546                         status = nfs4_reset_session(clp);
2547                         if (test_bit(NFS4CLNT_LEASE_EXPIRED, &clp->cl_state))
2548                                 continue;
2549                         if (status < 0)
2550                                 goto out_error;
2551                 }
2552 
2553                 /* Send BIND_CONN_TO_SESSION */
2554                 if (test_and_clear_bit(NFS4CLNT_BIND_CONN_TO_SESSION,
2555                                 &clp->cl_state)) {
2556                         section = "bind conn to session";
2557                         status = nfs4_bind_conn_to_session(clp);
2558                         if (status < 0)
2559                                 goto out_error;
2560                         continue;
2561                 }
2562 
2563                 if (test_and_clear_bit(NFS4CLNT_CHECK_LEASE, &clp->cl_state)) {
2564                         section = "check lease";
2565                         status = nfs4_check_lease(clp);
2566                         if (status < 0)
2567                                 goto out_error;
2568                         continue;
2569                 }
2570 
2571                 if (test_and_clear_bit(NFS4CLNT_MOVED, &clp->cl_state)) {
2572                         section = "migration";
2573                         status = nfs4_handle_migration(clp);
2574                         if (status < 0)
2575                                 goto out_error;
2576                 }
2577 
2578                 if (test_and_clear_bit(NFS4CLNT_LEASE_MOVED, &clp->cl_state)) {
2579                         section = "lease moved";
2580                         status = nfs4_handle_lease_moved(clp);
2581                         if (status < 0)
2582                                 goto out_error;
2583                 }
2584 
2585                 /* First recover reboot state... */
2586                 if (test_bit(NFS4CLNT_RECLAIM_REBOOT, &clp->cl_state)) {
2587                         section = "reclaim reboot";
2588                         status = nfs4_do_reclaim(clp,
2589                                 clp->cl_mvops->reboot_recovery_ops);
2590                         if (status == -EAGAIN)
2591                                 continue;
2592                         if (status < 0)
2593                                 goto out_error;
2594                         nfs4_state_end_reclaim_reboot(clp);
2595                 }
2596 
2597                 /* Detect expired delegations... */
2598                 if (test_and_clear_bit(NFS4CLNT_DELEGATION_EXPIRED, &clp->cl_state)) {
2599                         section = "detect expired delegations";
2600                         nfs_reap_expired_delegations(clp);
2601                         continue;
2602                 }
2603 
2604                 /* Now recover expired state... */
2605                 if (test_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state)) {
2606                         section = "reclaim nograce";
2607                         status = nfs4_do_reclaim(clp,
2608                                 clp->cl_mvops->nograce_recovery_ops);
2609                         if (status == -EAGAIN)
2610                                 continue;
2611                         if (status < 0)
2612                                 goto out_error;
2613                         clear_bit(NFS4CLNT_RECLAIM_NOGRACE, &clp->cl_state);
2614                 }
2615 
2616                 nfs4_end_drain_session(clp);
2617                 nfs4_clear_state_manager_bit(clp);
2618 
2619                 if (!test_and_set_bit(NFS4CLNT_DELEGRETURN_RUNNING, &clp->cl_state)) {
2620                         if (test_and_clear_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state)) {
2621                                 nfs_client_return_marked_delegations(clp);
2622                                 set_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state);
2623                         }
2624                         clear_bit(NFS4CLNT_DELEGRETURN_RUNNING, &clp->cl_state);
2625                 }
2626 
2627                 /* Did we race with an attempt to give us more work? */
2628                 if (!test_bit(NFS4CLNT_RUN_MANAGER, &clp->cl_state))
2629                         return;
2630                 if (test_and_set_bit(NFS4CLNT_MANAGER_RUNNING, &clp->cl_state) != 0)
2631                         return;
2632         } while (refcount_read(&clp->cl_count) > 1 && !signalled());
2633         goto out_drain;
2634 
2635 out_error:
2636         if (strlen(section))
2637                 section_sep = ": ";
2638         pr_warn_ratelimited("NFS: state manager%s%s failed on NFSv4 server %s"
2639                         " with error %d\n", section_sep, section,
2640                         clp->cl_hostname, -status);
2641         ssleep(1);
2642 out_drain:
2643         nfs4_end_drain_session(clp);
2644         nfs4_clear_state_manager_bit(clp);
2645 }
2646 
2647 static int nfs4_run_state_manager(void *ptr)
2648 {
2649         struct nfs_client *clp = ptr;
2650 
2651         allow_signal(SIGKILL);
2652         nfs4_state_manager(clp);
2653         nfs_put_client(clp);
2654         module_put_and_exit(0);
2655         return 0;
2656 }
2657 
2658 /*
2659  * Local variables:
2660  *  c-basic-offset: 8
2661  * End:
2662  */
2663 

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