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1/*
2 * linux/fs/nfs/delegation.c
3 *
4 * Copyright (C) 2004 Trond Myklebust
5 *
6 * NFS file delegation management
7 *
8 */
9#include <linux/completion.h>
10#include <linux/kthread.h>
11#include <linux/module.h>
12#include <linux/sched.h>
13#include <linux/slab.h>
14#include <linux/spinlock.h>
15#include <linux/iversion.h>
16
17#include <linux/nfs4.h>
18#include <linux/nfs_fs.h>
19#include <linux/nfs_xdr.h>
20
21#include "nfs4_fs.h"
22#include "nfs4session.h"
23#include "delegation.h"
24#include "internal.h"
25#include "nfs4trace.h"
26
27static void nfs_free_delegation(struct nfs_delegation *delegation)
28{
29 if (delegation->cred) {
30 put_rpccred(delegation->cred);
31 delegation->cred = NULL;
32 }
33 kfree_rcu(delegation, rcu);
34}
35
36/**
37 * nfs_mark_delegation_referenced - set delegation's REFERENCED flag
38 * @delegation: delegation to process
39 *
40 */
41void nfs_mark_delegation_referenced(struct nfs_delegation *delegation)
42{
43 set_bit(NFS_DELEGATION_REFERENCED, &delegation->flags);
44}
45
46static bool
47nfs4_is_valid_delegation(const struct nfs_delegation *delegation,
48 fmode_t flags)
49{
50 if (delegation != NULL && (delegation->type & flags) == flags &&
51 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) &&
52 !test_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
53 return true;
54 return false;
55}
56
57static int
58nfs4_do_check_delegation(struct inode *inode, fmode_t flags, bool mark)
59{
60 struct nfs_delegation *delegation;
61 int ret = 0;
62
63 flags &= FMODE_READ|FMODE_WRITE;
64 rcu_read_lock();
65 delegation = rcu_dereference(NFS_I(inode)->delegation);
66 if (nfs4_is_valid_delegation(delegation, flags)) {
67 if (mark)
68 nfs_mark_delegation_referenced(delegation);
69 ret = 1;
70 }
71 rcu_read_unlock();
72 return ret;
73}
74/**
75 * nfs_have_delegation - check if inode has a delegation, mark it
76 * NFS_DELEGATION_REFERENCED if there is one.
77 * @inode: inode to check
78 * @flags: delegation types to check for
79 *
80 * Returns one if inode has the indicated delegation, otherwise zero.
81 */
82int nfs4_have_delegation(struct inode *inode, fmode_t flags)
83{
84 return nfs4_do_check_delegation(inode, flags, true);
85}
86
87/*
88 * nfs4_check_delegation - check if inode has a delegation, do not mark
89 * NFS_DELEGATION_REFERENCED if it has one.
90 */
91int nfs4_check_delegation(struct inode *inode, fmode_t flags)
92{
93 return nfs4_do_check_delegation(inode, flags, false);
94}
95
96static int nfs_delegation_claim_locks(struct nfs_open_context *ctx, struct nfs4_state *state, const nfs4_stateid *stateid)
97{
98 struct inode *inode = state->inode;
99 struct file_lock *fl;
100 struct file_lock_context *flctx = inode->i_flctx;
101 struct list_head *list;
102 int status = 0;
103
104 if (flctx == NULL)
105 goto out;
106
107 list = &flctx->flc_posix;
108 spin_lock(&flctx->flc_lock);
109restart:
110 list_for_each_entry(fl, list, fl_list) {
111 if (nfs_file_open_context(fl->fl_file) != ctx)
112 continue;
113 spin_unlock(&flctx->flc_lock);
114 status = nfs4_lock_delegation_recall(fl, state, stateid);
115 if (status < 0)
116 goto out;
117 spin_lock(&flctx->flc_lock);
118 }
119 if (list == &flctx->flc_posix) {
120 list = &flctx->flc_flock;
121 goto restart;
122 }
123 spin_unlock(&flctx->flc_lock);
124out:
125 return status;
126}
127
128static int nfs_delegation_claim_opens(struct inode *inode,
129 const nfs4_stateid *stateid, fmode_t type)
130{
131 struct nfs_inode *nfsi = NFS_I(inode);
132 struct nfs_open_context *ctx;
133 struct nfs4_state_owner *sp;
134 struct nfs4_state *state;
135 unsigned int seq;
136 int err;
137
138again:
139 spin_lock(&inode->i_lock);
140 list_for_each_entry(ctx, &nfsi->open_files, list) {
141 state = ctx->state;
142 if (state == NULL)
143 continue;
144 if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
145 continue;
146 if (!nfs4_valid_open_stateid(state))
147 continue;
148 if (!nfs4_stateid_match(&state->stateid, stateid))
149 continue;
150 get_nfs_open_context(ctx);
151 spin_unlock(&inode->i_lock);
152 sp = state->owner;
153 /* Block nfs4_proc_unlck */
154 mutex_lock(&sp->so_delegreturn_mutex);
155 seq = raw_seqcount_begin(&sp->so_reclaim_seqcount);
156 err = nfs4_open_delegation_recall(ctx, state, stateid, type);
157 if (!err)
158 err = nfs_delegation_claim_locks(ctx, state, stateid);
159 if (!err && read_seqcount_retry(&sp->so_reclaim_seqcount, seq))
160 err = -EAGAIN;
161 mutex_unlock(&sp->so_delegreturn_mutex);
162 put_nfs_open_context(ctx);
163 if (err != 0)
164 return err;
165 goto again;
166 }
167 spin_unlock(&inode->i_lock);
168 return 0;
169}
170
171/**
172 * nfs_inode_reclaim_delegation - process a delegation reclaim request
173 * @inode: inode to process
174 * @cred: credential to use for request
175 * @type: delegation type
176 * @stateid: delegation stateid
177 * @pagemod_limit: write delegation "space_limit"
178 *
179 */
180void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred,
181 fmode_t type,
182 const nfs4_stateid *stateid,
183 unsigned long pagemod_limit)
184{
185 struct nfs_delegation *delegation;
186 struct rpc_cred *oldcred = NULL;
187
188 rcu_read_lock();
189 delegation = rcu_dereference(NFS_I(inode)->delegation);
190 if (delegation != NULL) {
191 spin_lock(&delegation->lock);
192 if (delegation->inode != NULL) {
193 nfs4_stateid_copy(&delegation->stateid, stateid);
194 delegation->type = type;
195 delegation->pagemod_limit = pagemod_limit;
196 oldcred = delegation->cred;
197 delegation->cred = get_rpccred(cred);
198 clear_bit(NFS_DELEGATION_NEED_RECLAIM,
199 &delegation->flags);
200 spin_unlock(&delegation->lock);
201 rcu_read_unlock();
202 put_rpccred(oldcred);
203 trace_nfs4_reclaim_delegation(inode, type);
204 return;
205 }
206 /* We appear to have raced with a delegation return. */
207 spin_unlock(&delegation->lock);
208 }
209 rcu_read_unlock();
210 nfs_inode_set_delegation(inode, cred, type, stateid, pagemod_limit);
211}
212
213static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync)
214{
215 int res = 0;
216
217 if (!test_bit(NFS_DELEGATION_REVOKED, &delegation->flags))
218 res = nfs4_proc_delegreturn(inode,
219 delegation->cred,
220 &delegation->stateid,
221 issync);
222 nfs_free_delegation(delegation);
223 return res;
224}
225
226static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation)
227{
228 struct inode *inode = NULL;
229
230 spin_lock(&delegation->lock);
231 if (delegation->inode != NULL)
232 inode = igrab(delegation->inode);
233 spin_unlock(&delegation->lock);
234 return inode;
235}
236
237static struct nfs_delegation *
238nfs_start_delegation_return_locked(struct nfs_inode *nfsi)
239{
240 struct nfs_delegation *ret = NULL;
241 struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation);
242
243 if (delegation == NULL)
244 goto out;
245 spin_lock(&delegation->lock);
246 if (!test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
247 ret = delegation;
248 spin_unlock(&delegation->lock);
249out:
250 return ret;
251}
252
253static struct nfs_delegation *
254nfs_start_delegation_return(struct nfs_inode *nfsi)
255{
256 struct nfs_delegation *delegation;
257
258 rcu_read_lock();
259 delegation = nfs_start_delegation_return_locked(nfsi);
260 rcu_read_unlock();
261 return delegation;
262}
263
264static void
265nfs_abort_delegation_return(struct nfs_delegation *delegation,
266 struct nfs_client *clp)
267{
268
269 spin_lock(&delegation->lock);
270 clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
271 set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
272 spin_unlock(&delegation->lock);
273 set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
274}
275
276static struct nfs_delegation *
277nfs_detach_delegation_locked(struct nfs_inode *nfsi,
278 struct nfs_delegation *delegation,
279 struct nfs_client *clp)
280{
281 struct nfs_delegation *deleg_cur =
282 rcu_dereference_protected(nfsi->delegation,
283 lockdep_is_held(&clp->cl_lock));
284
285 if (deleg_cur == NULL || delegation != deleg_cur)
286 return NULL;
287
288 spin_lock(&delegation->lock);
289 set_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
290 list_del_rcu(&delegation->super_list);
291 delegation->inode = NULL;
292 rcu_assign_pointer(nfsi->delegation, NULL);
293 spin_unlock(&delegation->lock);
294 return delegation;
295}
296
297static struct nfs_delegation *nfs_detach_delegation(struct nfs_inode *nfsi,
298 struct nfs_delegation *delegation,
299 struct nfs_server *server)
300{
301 struct nfs_client *clp = server->nfs_client;
302
303 spin_lock(&clp->cl_lock);
304 delegation = nfs_detach_delegation_locked(nfsi, delegation, clp);
305 spin_unlock(&clp->cl_lock);
306 return delegation;
307}
308
309static struct nfs_delegation *
310nfs_inode_detach_delegation(struct inode *inode)
311{
312 struct nfs_inode *nfsi = NFS_I(inode);
313 struct nfs_server *server = NFS_SERVER(inode);
314 struct nfs_delegation *delegation;
315
316 delegation = nfs_start_delegation_return(nfsi);
317 if (delegation == NULL)
318 return NULL;
319 return nfs_detach_delegation(nfsi, delegation, server);
320}
321
322static void
323nfs_update_inplace_delegation(struct nfs_delegation *delegation,
324 const struct nfs_delegation *update)
325{
326 if (nfs4_stateid_is_newer(&update->stateid, &delegation->stateid)) {
327 delegation->stateid.seqid = update->stateid.seqid;
328 smp_wmb();
329 delegation->type = update->type;
330 }
331}
332
333/**
334 * nfs_inode_set_delegation - set up a delegation on an inode
335 * @inode: inode to which delegation applies
336 * @cred: cred to use for subsequent delegation processing
337 * @type: delegation type
338 * @stateid: delegation stateid
339 * @pagemod_limit: write delegation "space_limit"
340 *
341 * Returns zero on success, or a negative errno value.
342 */
343int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred,
344 fmode_t type,
345 const nfs4_stateid *stateid,
346 unsigned long pagemod_limit)
347{
348 struct nfs_server *server = NFS_SERVER(inode);
349 struct nfs_client *clp = server->nfs_client;
350 struct nfs_inode *nfsi = NFS_I(inode);
351 struct nfs_delegation *delegation, *old_delegation;
352 struct nfs_delegation *freeme = NULL;
353 int status = 0;
354
355 delegation = kmalloc(sizeof(*delegation), GFP_NOFS);
356 if (delegation == NULL)
357 return -ENOMEM;
358 nfs4_stateid_copy(&delegation->stateid, stateid);
359 delegation->type = type;
360 delegation->pagemod_limit = pagemod_limit;
361 delegation->change_attr = inode_peek_iversion_raw(inode);
362 delegation->cred = get_rpccred(cred);
363 delegation->inode = inode;
364 delegation->flags = 1<<NFS_DELEGATION_REFERENCED;
365 spin_lock_init(&delegation->lock);
366
367 spin_lock(&clp->cl_lock);
368 old_delegation = rcu_dereference_protected(nfsi->delegation,
369 lockdep_is_held(&clp->cl_lock));
370 if (old_delegation != NULL) {
371 /* Is this an update of the existing delegation? */
372 if (nfs4_stateid_match_other(&old_delegation->stateid,
373 &delegation->stateid)) {
374 nfs_update_inplace_delegation(old_delegation,
375 delegation);
376 goto out;
377 }
378 /*
379 * Deal with broken servers that hand out two
380 * delegations for the same file.
381 * Allow for upgrades to a WRITE delegation, but
382 * nothing else.
383 */
384 dfprintk(FILE, "%s: server %s handed out "
385 "a duplicate delegation!\n",
386 __func__, clp->cl_hostname);
387 if (delegation->type == old_delegation->type ||
388 !(delegation->type & FMODE_WRITE)) {
389 freeme = delegation;
390 delegation = NULL;
391 goto out;
392 }
393 if (test_and_set_bit(NFS_DELEGATION_RETURNING,
394 &old_delegation->flags))
395 goto out;
396 freeme = nfs_detach_delegation_locked(nfsi,
397 old_delegation, clp);
398 if (freeme == NULL)
399 goto out;
400 }
401 list_add_tail_rcu(&delegation->super_list, &server->delegations);
402 rcu_assign_pointer(nfsi->delegation, delegation);
403 delegation = NULL;
404
405 trace_nfs4_set_delegation(inode, type);
406
407out:
408 spin_unlock(&clp->cl_lock);
409 if (delegation != NULL)
410 nfs_free_delegation(delegation);
411 if (freeme != NULL)
412 nfs_do_return_delegation(inode, freeme, 0);
413 return status;
414}
415
416/*
417 * Basic procedure for returning a delegation to the server
418 */
419static int nfs_end_delegation_return(struct inode *inode, struct nfs_delegation *delegation, int issync)
420{
421 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
422 struct nfs_inode *nfsi = NFS_I(inode);
423 int err = 0;
424
425 if (delegation == NULL)
426 return 0;
427 do {
428 if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags))
429 break;
430 err = nfs_delegation_claim_opens(inode, &delegation->stateid,
431 delegation->type);
432 if (!issync || err != -EAGAIN)
433 break;
434 /*
435 * Guard against state recovery
436 */
437 err = nfs4_wait_clnt_recover(clp);
438 } while (err == 0);
439
440 if (err) {
441 nfs_abort_delegation_return(delegation, clp);
442 goto out;
443 }
444 if (!nfs_detach_delegation(nfsi, delegation, NFS_SERVER(inode)))
445 goto out;
446
447 err = nfs_do_return_delegation(inode, delegation, issync);
448out:
449 return err;
450}
451
452static bool nfs_delegation_need_return(struct nfs_delegation *delegation)
453{
454 bool ret = false;
455
456 if (test_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
457 goto out;
458 if (test_and_clear_bit(NFS_DELEGATION_RETURN, &delegation->flags))
459 ret = true;
460 if (test_and_clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags) && !ret) {
461 struct inode *inode;
462
463 spin_lock(&delegation->lock);
464 inode = delegation->inode;
465 if (inode && list_empty(&NFS_I(inode)->open_files))
466 ret = true;
467 spin_unlock(&delegation->lock);
468 }
469out:
470 return ret;
471}
472
473/**
474 * nfs_client_return_marked_delegations - return previously marked delegations
475 * @clp: nfs_client to process
476 *
477 * Note that this function is designed to be called by the state
478 * manager thread. For this reason, it cannot flush the dirty data,
479 * since that could deadlock in case of a state recovery error.
480 *
481 * Returns zero on success, or a negative errno value.
482 */
483int nfs_client_return_marked_delegations(struct nfs_client *clp)
484{
485 struct nfs_delegation *delegation;
486 struct nfs_server *server;
487 struct inode *inode;
488 int err = 0;
489
490restart:
491 rcu_read_lock();
492 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
493 list_for_each_entry_rcu(delegation, &server->delegations,
494 super_list) {
495 if (!nfs_delegation_need_return(delegation))
496 continue;
497 if (!nfs_sb_active(server->super))
498 continue;
499 inode = nfs_delegation_grab_inode(delegation);
500 if (inode == NULL) {
501 rcu_read_unlock();
502 nfs_sb_deactive(server->super);
503 goto restart;
504 }
505 delegation = nfs_start_delegation_return_locked(NFS_I(inode));
506 rcu_read_unlock();
507
508 err = nfs_end_delegation_return(inode, delegation, 0);
509 iput(inode);
510 nfs_sb_deactive(server->super);
511 if (!err)
512 goto restart;
513 set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
514 return err;
515 }
516 }
517 rcu_read_unlock();
518 return 0;
519}
520
521/**
522 * nfs_inode_return_delegation_noreclaim - return delegation, don't reclaim opens
523 * @inode: inode to process
524 *
525 * Does not protect against delegation reclaims, therefore really only safe
526 * to be called from nfs4_clear_inode().
527 */
528void nfs_inode_return_delegation_noreclaim(struct inode *inode)
529{
530 struct nfs_delegation *delegation;
531
532 delegation = nfs_inode_detach_delegation(inode);
533 if (delegation != NULL)
534 nfs_do_return_delegation(inode, delegation, 1);
535}
536
537/**
538 * nfs_inode_return_delegation - synchronously return a delegation
539 * @inode: inode to process
540 *
541 * This routine will always flush any dirty data to disk on the
542 * assumption that if we need to return the delegation, then
543 * we should stop caching.
544 *
545 * Returns zero on success, or a negative errno value.
546 */
547int nfs4_inode_return_delegation(struct inode *inode)
548{
549 struct nfs_inode *nfsi = NFS_I(inode);
550 struct nfs_delegation *delegation;
551 int err = 0;
552
553 nfs_wb_all(inode);
554 delegation = nfs_start_delegation_return(nfsi);
555 if (delegation != NULL)
556 err = nfs_end_delegation_return(inode, delegation, 1);
557 return err;
558}
559
560/**
561 * nfs4_inode_make_writeable
562 * @inode: pointer to inode
563 *
564 * Make the inode writeable by returning the delegation if necessary
565 *
566 * Returns zero on success, or a negative errno value.
567 */
568int nfs4_inode_make_writeable(struct inode *inode)
569{
570 if (!nfs4_has_session(NFS_SERVER(inode)->nfs_client) ||
571 !nfs4_check_delegation(inode, FMODE_WRITE))
572 return nfs4_inode_return_delegation(inode);
573 return 0;
574}
575
576static void nfs_mark_return_if_closed_delegation(struct nfs_server *server,
577 struct nfs_delegation *delegation)
578{
579 set_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags);
580 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
581}
582
583static void nfs_mark_return_delegation(struct nfs_server *server,
584 struct nfs_delegation *delegation)
585{
586 set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
587 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
588}
589
590static bool nfs_server_mark_return_all_delegations(struct nfs_server *server)
591{
592 struct nfs_delegation *delegation;
593 bool ret = false;
594
595 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
596 nfs_mark_return_delegation(server, delegation);
597 ret = true;
598 }
599 return ret;
600}
601
602static void nfs_client_mark_return_all_delegations(struct nfs_client *clp)
603{
604 struct nfs_server *server;
605
606 rcu_read_lock();
607 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
608 nfs_server_mark_return_all_delegations(server);
609 rcu_read_unlock();
610}
611
612static void nfs_delegation_run_state_manager(struct nfs_client *clp)
613{
614 if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state))
615 nfs4_schedule_state_manager(clp);
616}
617
618/**
619 * nfs_expire_all_delegations
620 * @clp: client to process
621 *
622 */
623void nfs_expire_all_delegations(struct nfs_client *clp)
624{
625 nfs_client_mark_return_all_delegations(clp);
626 nfs_delegation_run_state_manager(clp);
627}
628
629/**
630 * nfs_super_return_all_delegations - return delegations for one superblock
631 * @sb: sb to process
632 *
633 */
634void nfs_server_return_all_delegations(struct nfs_server *server)
635{
636 struct nfs_client *clp = server->nfs_client;
637 bool need_wait;
638
639 if (clp == NULL)
640 return;
641
642 rcu_read_lock();
643 need_wait = nfs_server_mark_return_all_delegations(server);
644 rcu_read_unlock();
645
646 if (need_wait) {
647 nfs4_schedule_state_manager(clp);
648 nfs4_wait_clnt_recover(clp);
649 }
650}
651
652static void nfs_mark_return_unused_delegation_types(struct nfs_server *server,
653 fmode_t flags)
654{
655 struct nfs_delegation *delegation;
656
657 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
658 if ((delegation->type == (FMODE_READ|FMODE_WRITE)) && !(flags & FMODE_WRITE))
659 continue;
660 if (delegation->type & flags)
661 nfs_mark_return_if_closed_delegation(server, delegation);
662 }
663}
664
665static void nfs_client_mark_return_unused_delegation_types(struct nfs_client *clp,
666 fmode_t flags)
667{
668 struct nfs_server *server;
669
670 rcu_read_lock();
671 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
672 nfs_mark_return_unused_delegation_types(server, flags);
673 rcu_read_unlock();
674}
675
676static void nfs_mark_delegation_revoked(struct nfs_server *server,
677 struct nfs_delegation *delegation)
678{
679 set_bit(NFS_DELEGATION_REVOKED, &delegation->flags);
680 delegation->stateid.type = NFS4_INVALID_STATEID_TYPE;
681 nfs_mark_return_delegation(server, delegation);
682}
683
684static bool nfs_revoke_delegation(struct inode *inode,
685 const nfs4_stateid *stateid)
686{
687 struct nfs_delegation *delegation;
688 nfs4_stateid tmp;
689 bool ret = false;
690
691 rcu_read_lock();
692 delegation = rcu_dereference(NFS_I(inode)->delegation);
693 if (delegation == NULL)
694 goto out;
695 if (stateid == NULL) {
696 nfs4_stateid_copy(&tmp, &delegation->stateid);
697 stateid = &tmp;
698 } else if (!nfs4_stateid_match(stateid, &delegation->stateid))
699 goto out;
700 nfs_mark_delegation_revoked(NFS_SERVER(inode), delegation);
701 ret = true;
702out:
703 rcu_read_unlock();
704 if (ret)
705 nfs_inode_find_state_and_recover(inode, stateid);
706 return ret;
707}
708
709void nfs_remove_bad_delegation(struct inode *inode,
710 const nfs4_stateid *stateid)
711{
712 struct nfs_delegation *delegation;
713
714 if (!nfs_revoke_delegation(inode, stateid))
715 return;
716 delegation = nfs_inode_detach_delegation(inode);
717 if (delegation)
718 nfs_free_delegation(delegation);
719}
720EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation);
721
722/**
723 * nfs_expire_unused_delegation_types
724 * @clp: client to process
725 * @flags: delegation types to expire
726 *
727 */
728void nfs_expire_unused_delegation_types(struct nfs_client *clp, fmode_t flags)
729{
730 nfs_client_mark_return_unused_delegation_types(clp, flags);
731 nfs_delegation_run_state_manager(clp);
732}
733
734static void nfs_mark_return_unreferenced_delegations(struct nfs_server *server)
735{
736 struct nfs_delegation *delegation;
737
738 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
739 if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags))
740 continue;
741 nfs_mark_return_if_closed_delegation(server, delegation);
742 }
743}
744
745/**
746 * nfs_expire_unreferenced_delegations - Eliminate unused delegations
747 * @clp: nfs_client to process
748 *
749 */
750void nfs_expire_unreferenced_delegations(struct nfs_client *clp)
751{
752 struct nfs_server *server;
753
754 rcu_read_lock();
755 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
756 nfs_mark_return_unreferenced_delegations(server);
757 rcu_read_unlock();
758
759 nfs_delegation_run_state_manager(clp);
760}
761
762/**
763 * nfs_async_inode_return_delegation - asynchronously return a delegation
764 * @inode: inode to process
765 * @stateid: state ID information
766 *
767 * Returns zero on success, or a negative errno value.
768 */
769int nfs_async_inode_return_delegation(struct inode *inode,
770 const nfs4_stateid *stateid)
771{
772 struct nfs_server *server = NFS_SERVER(inode);
773 struct nfs_client *clp = server->nfs_client;
774 struct nfs_delegation *delegation;
775
776 rcu_read_lock();
777 delegation = rcu_dereference(NFS_I(inode)->delegation);
778 if (delegation == NULL)
779 goto out_enoent;
780 if (stateid != NULL &&
781 !clp->cl_mvops->match_stateid(&delegation->stateid, stateid))
782 goto out_enoent;
783 nfs_mark_return_delegation(server, delegation);
784 rcu_read_unlock();
785
786 nfs_delegation_run_state_manager(clp);
787 return 0;
788out_enoent:
789 rcu_read_unlock();
790 return -ENOENT;
791}
792
793static struct inode *
794nfs_delegation_find_inode_server(struct nfs_server *server,
795 const struct nfs_fh *fhandle)
796{
797 struct nfs_delegation *delegation;
798 struct inode *res = NULL;
799
800 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
801 spin_lock(&delegation->lock);
802 if (delegation->inode != NULL &&
803 nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
804 res = igrab(delegation->inode);
805 }
806 spin_unlock(&delegation->lock);
807 if (res != NULL)
808 break;
809 }
810 return res;
811}
812
813/**
814 * nfs_delegation_find_inode - retrieve the inode associated with a delegation
815 * @clp: client state handle
816 * @fhandle: filehandle from a delegation recall
817 *
818 * Returns pointer to inode matching "fhandle," or NULL if a matching inode
819 * cannot be found.
820 */
821struct inode *nfs_delegation_find_inode(struct nfs_client *clp,
822 const struct nfs_fh *fhandle)
823{
824 struct nfs_server *server;
825 struct inode *res = NULL;
826
827 rcu_read_lock();
828 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
829 res = nfs_delegation_find_inode_server(server, fhandle);
830 if (res != NULL)
831 break;
832 }
833 rcu_read_unlock();
834 return res;
835}
836
837static void nfs_delegation_mark_reclaim_server(struct nfs_server *server)
838{
839 struct nfs_delegation *delegation;
840
841 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
842 /*
843 * If the delegation may have been admin revoked, then we
844 * cannot reclaim it.
845 */
846 if (test_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags))
847 continue;
848 set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
849 }
850}
851
852/**
853 * nfs_delegation_mark_reclaim - mark all delegations as needing to be reclaimed
854 * @clp: nfs_client to process
855 *
856 */
857void nfs_delegation_mark_reclaim(struct nfs_client *clp)
858{
859 struct nfs_server *server;
860
861 rcu_read_lock();
862 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
863 nfs_delegation_mark_reclaim_server(server);
864 rcu_read_unlock();
865}
866
867/**
868 * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done
869 * @clp: nfs_client to process
870 *
871 */
872void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
873{
874 struct nfs_delegation *delegation;
875 struct nfs_server *server;
876 struct inode *inode;
877
878restart:
879 rcu_read_lock();
880 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
881 list_for_each_entry_rcu(delegation, &server->delegations,
882 super_list) {
883 if (test_bit(NFS_DELEGATION_RETURNING,
884 &delegation->flags))
885 continue;
886 if (test_bit(NFS_DELEGATION_NEED_RECLAIM,
887 &delegation->flags) == 0)
888 continue;
889 if (!nfs_sb_active(server->super))
890 continue;
891 inode = nfs_delegation_grab_inode(delegation);
892 if (inode == NULL) {
893 rcu_read_unlock();
894 nfs_sb_deactive(server->super);
895 goto restart;
896 }
897 delegation = nfs_start_delegation_return_locked(NFS_I(inode));
898 rcu_read_unlock();
899 if (delegation != NULL) {
900 delegation = nfs_detach_delegation(NFS_I(inode),
901 delegation, server);
902 if (delegation != NULL)
903 nfs_free_delegation(delegation);
904 }
905 iput(inode);
906 nfs_sb_deactive(server->super);
907 goto restart;
908 }
909 }
910 rcu_read_unlock();
911}
912
913static inline bool nfs4_server_rebooted(const struct nfs_client *clp)
914{
915 return (clp->cl_state & (BIT(NFS4CLNT_CHECK_LEASE) |
916 BIT(NFS4CLNT_LEASE_EXPIRED) |
917 BIT(NFS4CLNT_SESSION_RESET))) != 0;
918}
919
920static void nfs_mark_test_expired_delegation(struct nfs_server *server,
921 struct nfs_delegation *delegation)
922{
923 if (delegation->stateid.type == NFS4_INVALID_STATEID_TYPE)
924 return;
925 clear_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
926 set_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags);
927 set_bit(NFS4CLNT_DELEGATION_EXPIRED, &server->nfs_client->cl_state);
928}
929
930static void nfs_inode_mark_test_expired_delegation(struct nfs_server *server,
931 struct inode *inode)
932{
933 struct nfs_delegation *delegation;
934
935 rcu_read_lock();
936 delegation = rcu_dereference(NFS_I(inode)->delegation);
937 if (delegation)
938 nfs_mark_test_expired_delegation(server, delegation);
939 rcu_read_unlock();
940
941}
942
943static void nfs_delegation_mark_test_expired_server(struct nfs_server *server)
944{
945 struct nfs_delegation *delegation;
946
947 list_for_each_entry_rcu(delegation, &server->delegations, super_list)
948 nfs_mark_test_expired_delegation(server, delegation);
949}
950
951/**
952 * nfs_mark_test_expired_all_delegations - mark all delegations for testing
953 * @clp: nfs_client to process
954 *
955 * Iterates through all the delegations associated with this server and
956 * marks them as needing to be checked for validity.
957 */
958void nfs_mark_test_expired_all_delegations(struct nfs_client *clp)
959{
960 struct nfs_server *server;
961
962 rcu_read_lock();
963 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
964 nfs_delegation_mark_test_expired_server(server);
965 rcu_read_unlock();
966}
967
968/**
969 * nfs_reap_expired_delegations - reap expired delegations
970 * @clp: nfs_client to process
971 *
972 * Iterates through all the delegations associated with this server and
973 * checks if they have may have been revoked. This function is usually
974 * expected to be called in cases where the server may have lost its
975 * lease.
976 */
977void nfs_reap_expired_delegations(struct nfs_client *clp)
978{
979 const struct nfs4_minor_version_ops *ops = clp->cl_mvops;
980 struct nfs_delegation *delegation;
981 struct nfs_server *server;
982 struct inode *inode;
983 struct rpc_cred *cred;
984 nfs4_stateid stateid;
985
986restart:
987 rcu_read_lock();
988 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
989 list_for_each_entry_rcu(delegation, &server->delegations,
990 super_list) {
991 if (test_bit(NFS_DELEGATION_RETURNING,
992 &delegation->flags))
993 continue;
994 if (test_bit(NFS_DELEGATION_TEST_EXPIRED,
995 &delegation->flags) == 0)
996 continue;
997 if (!nfs_sb_active(server->super))
998 continue;
999 inode = nfs_delegation_grab_inode(delegation);
1000 if (inode == NULL) {
1001 rcu_read_unlock();
1002 nfs_sb_deactive(server->super);
1003 goto restart;
1004 }
1005 cred = get_rpccred_rcu(delegation->cred);
1006 nfs4_stateid_copy(&stateid, &delegation->stateid);
1007 clear_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags);
1008 rcu_read_unlock();
1009 if (cred != NULL &&
1010 ops->test_and_free_expired(server, &stateid, cred) < 0) {
1011 nfs_revoke_delegation(inode, &stateid);
1012 nfs_inode_find_state_and_recover(inode, &stateid);
1013 }
1014 put_rpccred(cred);
1015 if (nfs4_server_rebooted(clp)) {
1016 nfs_inode_mark_test_expired_delegation(server,inode);
1017 iput(inode);
1018 nfs_sb_deactive(server->super);
1019 return;
1020 }
1021 iput(inode);
1022 nfs_sb_deactive(server->super);
1023 goto restart;
1024 }
1025 }
1026 rcu_read_unlock();
1027}
1028
1029void nfs_inode_find_delegation_state_and_recover(struct inode *inode,
1030 const nfs4_stateid *stateid)
1031{
1032 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
1033 struct nfs_delegation *delegation;
1034 bool found = false;
1035
1036 rcu_read_lock();
1037 delegation = rcu_dereference(NFS_I(inode)->delegation);
1038 if (delegation &&
1039 nfs4_stateid_match_other(&delegation->stateid, stateid)) {
1040 nfs_mark_test_expired_delegation(NFS_SERVER(inode), delegation);
1041 found = true;
1042 }
1043 rcu_read_unlock();
1044 if (found)
1045 nfs4_schedule_state_manager(clp);
1046}
1047
1048/**
1049 * nfs_delegations_present - check for existence of delegations
1050 * @clp: client state handle
1051 *
1052 * Returns one if there are any nfs_delegation structures attached
1053 * to this nfs_client.
1054 */
1055int nfs_delegations_present(struct nfs_client *clp)
1056{
1057 struct nfs_server *server;
1058 int ret = 0;
1059
1060 rcu_read_lock();
1061 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1062 if (!list_empty(&server->delegations)) {
1063 ret = 1;
1064 break;
1065 }
1066 rcu_read_unlock();
1067 return ret;
1068}
1069
1070/**
1071 * nfs4_refresh_delegation_stateid - Update delegation stateid seqid
1072 * @dst: stateid to refresh
1073 * @inode: inode to check
1074 *
1075 * Returns "true" and updates "dst->seqid" * if inode had a delegation
1076 * that matches our delegation stateid. Otherwise "false" is returned.
1077 */
1078bool nfs4_refresh_delegation_stateid(nfs4_stateid *dst, struct inode *inode)
1079{
1080 struct nfs_delegation *delegation;
1081 bool ret = false;
1082 if (!inode)
1083 goto out;
1084
1085 rcu_read_lock();
1086 delegation = rcu_dereference(NFS_I(inode)->delegation);
1087 if (delegation != NULL &&
1088 nfs4_stateid_match_other(dst, &delegation->stateid)) {
1089 dst->seqid = delegation->stateid.seqid;
1090 return ret;
1091 }
1092 rcu_read_unlock();
1093out:
1094 return ret;
1095}
1096
1097/**
1098 * nfs4_copy_delegation_stateid - Copy inode's state ID information
1099 * @inode: inode to check
1100 * @flags: delegation type requirement
1101 * @dst: stateid data structure to fill in
1102 * @cred: optional argument to retrieve credential
1103 *
1104 * Returns "true" and fills in "dst->data" * if inode had a delegation,
1105 * otherwise "false" is returned.
1106 */
1107bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags,
1108 nfs4_stateid *dst, struct rpc_cred **cred)
1109{
1110 struct nfs_inode *nfsi = NFS_I(inode);
1111 struct nfs_delegation *delegation;
1112 bool ret;
1113
1114 flags &= FMODE_READ|FMODE_WRITE;
1115 rcu_read_lock();
1116 delegation = rcu_dereference(nfsi->delegation);
1117 ret = nfs4_is_valid_delegation(delegation, flags);
1118 if (ret) {
1119 nfs4_stateid_copy(dst, &delegation->stateid);
1120 nfs_mark_delegation_referenced(delegation);
1121 if (cred)
1122 *cred = get_rpccred(delegation->cred);
1123 }
1124 rcu_read_unlock();
1125 return ret;
1126}
1127
1128/**
1129 * nfs4_delegation_flush_on_close - Check if we must flush file on close
1130 * @inode: inode to check
1131 *
1132 * This function checks the number of outstanding writes to the file
1133 * against the delegation 'space_limit' field to see if
1134 * the spec requires us to flush the file on close.
1135 */
1136bool nfs4_delegation_flush_on_close(const struct inode *inode)
1137{
1138 struct nfs_inode *nfsi = NFS_I(inode);
1139 struct nfs_delegation *delegation;
1140 bool ret = true;
1141
1142 rcu_read_lock();
1143 delegation = rcu_dereference(nfsi->delegation);
1144 if (delegation == NULL || !(delegation->type & FMODE_WRITE))
1145 goto out;
1146 if (atomic_long_read(&nfsi->nrequests) < delegation->pagemod_limit)
1147 ret = false;
1148out:
1149 rcu_read_unlock();
1150 return ret;
1151}
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/fs/nfs/delegation.c
4 *
5 * Copyright (C) 2004 Trond Myklebust
6 *
7 * NFS file delegation management
8 *
9 */
10#include <linux/completion.h>
11#include <linux/kthread.h>
12#include <linux/module.h>
13#include <linux/sched.h>
14#include <linux/slab.h>
15#include <linux/spinlock.h>
16#include <linux/iversion.h>
17
18#include <linux/nfs4.h>
19#include <linux/nfs_fs.h>
20#include <linux/nfs_xdr.h>
21
22#include "nfs4_fs.h"
23#include "nfs4session.h"
24#include "delegation.h"
25#include "internal.h"
26#include "nfs4trace.h"
27
28static void nfs_free_delegation(struct nfs_delegation *delegation)
29{
30 put_cred(delegation->cred);
31 delegation->cred = NULL;
32 kfree_rcu(delegation, rcu);
33}
34
35/**
36 * nfs_mark_delegation_referenced - set delegation's REFERENCED flag
37 * @delegation: delegation to process
38 *
39 */
40void nfs_mark_delegation_referenced(struct nfs_delegation *delegation)
41{
42 set_bit(NFS_DELEGATION_REFERENCED, &delegation->flags);
43}
44
45static bool
46nfs4_is_valid_delegation(const struct nfs_delegation *delegation,
47 fmode_t flags)
48{
49 if (delegation != NULL && (delegation->type & flags) == flags &&
50 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) &&
51 !test_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
52 return true;
53 return false;
54}
55
56struct nfs_delegation *nfs4_get_valid_delegation(const struct inode *inode)
57{
58 struct nfs_delegation *delegation;
59
60 delegation = rcu_dereference(NFS_I(inode)->delegation);
61 if (nfs4_is_valid_delegation(delegation, 0))
62 return delegation;
63 return NULL;
64}
65
66static int
67nfs4_do_check_delegation(struct inode *inode, fmode_t flags, bool mark)
68{
69 struct nfs_delegation *delegation;
70 int ret = 0;
71
72 flags &= FMODE_READ|FMODE_WRITE;
73 rcu_read_lock();
74 delegation = rcu_dereference(NFS_I(inode)->delegation);
75 if (nfs4_is_valid_delegation(delegation, flags)) {
76 if (mark)
77 nfs_mark_delegation_referenced(delegation);
78 ret = 1;
79 }
80 rcu_read_unlock();
81 return ret;
82}
83/**
84 * nfs_have_delegation - check if inode has a delegation, mark it
85 * NFS_DELEGATION_REFERENCED if there is one.
86 * @inode: inode to check
87 * @flags: delegation types to check for
88 *
89 * Returns one if inode has the indicated delegation, otherwise zero.
90 */
91int nfs4_have_delegation(struct inode *inode, fmode_t flags)
92{
93 return nfs4_do_check_delegation(inode, flags, true);
94}
95
96/*
97 * nfs4_check_delegation - check if inode has a delegation, do not mark
98 * NFS_DELEGATION_REFERENCED if it has one.
99 */
100int nfs4_check_delegation(struct inode *inode, fmode_t flags)
101{
102 return nfs4_do_check_delegation(inode, flags, false);
103}
104
105static int nfs_delegation_claim_locks(struct nfs4_state *state, const nfs4_stateid *stateid)
106{
107 struct inode *inode = state->inode;
108 struct file_lock *fl;
109 struct file_lock_context *flctx = inode->i_flctx;
110 struct list_head *list;
111 int status = 0;
112
113 if (flctx == NULL)
114 goto out;
115
116 list = &flctx->flc_posix;
117 spin_lock(&flctx->flc_lock);
118restart:
119 list_for_each_entry(fl, list, fl_list) {
120 if (nfs_file_open_context(fl->fl_file)->state != state)
121 continue;
122 spin_unlock(&flctx->flc_lock);
123 status = nfs4_lock_delegation_recall(fl, state, stateid);
124 if (status < 0)
125 goto out;
126 spin_lock(&flctx->flc_lock);
127 }
128 if (list == &flctx->flc_posix) {
129 list = &flctx->flc_flock;
130 goto restart;
131 }
132 spin_unlock(&flctx->flc_lock);
133out:
134 return status;
135}
136
137static int nfs_delegation_claim_opens(struct inode *inode,
138 const nfs4_stateid *stateid, fmode_t type)
139{
140 struct nfs_inode *nfsi = NFS_I(inode);
141 struct nfs_open_context *ctx;
142 struct nfs4_state_owner *sp;
143 struct nfs4_state *state;
144 unsigned int seq;
145 int err;
146
147again:
148 rcu_read_lock();
149 list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
150 state = ctx->state;
151 if (state == NULL)
152 continue;
153 if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
154 continue;
155 if (!nfs4_valid_open_stateid(state))
156 continue;
157 if (!nfs4_stateid_match(&state->stateid, stateid))
158 continue;
159 if (!get_nfs_open_context(ctx))
160 continue;
161 rcu_read_unlock();
162 sp = state->owner;
163 /* Block nfs4_proc_unlck */
164 mutex_lock(&sp->so_delegreturn_mutex);
165 seq = raw_seqcount_begin(&sp->so_reclaim_seqcount);
166 err = nfs4_open_delegation_recall(ctx, state, stateid);
167 if (!err)
168 err = nfs_delegation_claim_locks(state, stateid);
169 if (!err && read_seqcount_retry(&sp->so_reclaim_seqcount, seq))
170 err = -EAGAIN;
171 mutex_unlock(&sp->so_delegreturn_mutex);
172 put_nfs_open_context(ctx);
173 if (err != 0)
174 return err;
175 goto again;
176 }
177 rcu_read_unlock();
178 return 0;
179}
180
181/**
182 * nfs_inode_reclaim_delegation - process a delegation reclaim request
183 * @inode: inode to process
184 * @cred: credential to use for request
185 * @type: delegation type
186 * @stateid: delegation stateid
187 * @pagemod_limit: write delegation "space_limit"
188 *
189 */
190void nfs_inode_reclaim_delegation(struct inode *inode, const struct cred *cred,
191 fmode_t type,
192 const nfs4_stateid *stateid,
193 unsigned long pagemod_limit)
194{
195 struct nfs_delegation *delegation;
196 const struct cred *oldcred = NULL;
197
198 rcu_read_lock();
199 delegation = rcu_dereference(NFS_I(inode)->delegation);
200 if (delegation != NULL) {
201 spin_lock(&delegation->lock);
202 if (delegation->inode != NULL) {
203 nfs4_stateid_copy(&delegation->stateid, stateid);
204 delegation->type = type;
205 delegation->pagemod_limit = pagemod_limit;
206 oldcred = delegation->cred;
207 delegation->cred = get_cred(cred);
208 clear_bit(NFS_DELEGATION_NEED_RECLAIM,
209 &delegation->flags);
210 spin_unlock(&delegation->lock);
211 rcu_read_unlock();
212 put_cred(oldcred);
213 trace_nfs4_reclaim_delegation(inode, type);
214 return;
215 }
216 /* We appear to have raced with a delegation return. */
217 spin_unlock(&delegation->lock);
218 }
219 rcu_read_unlock();
220 nfs_inode_set_delegation(inode, cred, type, stateid, pagemod_limit);
221}
222
223static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync)
224{
225 int res = 0;
226
227 if (!test_bit(NFS_DELEGATION_REVOKED, &delegation->flags))
228 res = nfs4_proc_delegreturn(inode,
229 delegation->cred,
230 &delegation->stateid,
231 issync);
232 nfs_free_delegation(delegation);
233 return res;
234}
235
236static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation)
237{
238 struct inode *inode = NULL;
239
240 spin_lock(&delegation->lock);
241 if (delegation->inode != NULL)
242 inode = igrab(delegation->inode);
243 if (!inode)
244 set_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags);
245 spin_unlock(&delegation->lock);
246 return inode;
247}
248
249static struct nfs_delegation *
250nfs_start_delegation_return_locked(struct nfs_inode *nfsi)
251{
252 struct nfs_delegation *ret = NULL;
253 struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation);
254
255 if (delegation == NULL)
256 goto out;
257 spin_lock(&delegation->lock);
258 if (!test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
259 ret = delegation;
260 spin_unlock(&delegation->lock);
261out:
262 return ret;
263}
264
265static struct nfs_delegation *
266nfs_start_delegation_return(struct nfs_inode *nfsi)
267{
268 struct nfs_delegation *delegation;
269
270 rcu_read_lock();
271 delegation = nfs_start_delegation_return_locked(nfsi);
272 rcu_read_unlock();
273 return delegation;
274}
275
276static void
277nfs_abort_delegation_return(struct nfs_delegation *delegation,
278 struct nfs_client *clp)
279{
280
281 spin_lock(&delegation->lock);
282 clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
283 set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
284 spin_unlock(&delegation->lock);
285 set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
286}
287
288static struct nfs_delegation *
289nfs_detach_delegation_locked(struct nfs_inode *nfsi,
290 struct nfs_delegation *delegation,
291 struct nfs_client *clp)
292{
293 struct nfs_delegation *deleg_cur =
294 rcu_dereference_protected(nfsi->delegation,
295 lockdep_is_held(&clp->cl_lock));
296
297 if (deleg_cur == NULL || delegation != deleg_cur)
298 return NULL;
299
300 spin_lock(&delegation->lock);
301 set_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
302 list_del_rcu(&delegation->super_list);
303 delegation->inode = NULL;
304 rcu_assign_pointer(nfsi->delegation, NULL);
305 spin_unlock(&delegation->lock);
306 return delegation;
307}
308
309static struct nfs_delegation *nfs_detach_delegation(struct nfs_inode *nfsi,
310 struct nfs_delegation *delegation,
311 struct nfs_server *server)
312{
313 struct nfs_client *clp = server->nfs_client;
314
315 spin_lock(&clp->cl_lock);
316 delegation = nfs_detach_delegation_locked(nfsi, delegation, clp);
317 spin_unlock(&clp->cl_lock);
318 return delegation;
319}
320
321static struct nfs_delegation *
322nfs_inode_detach_delegation(struct inode *inode)
323{
324 struct nfs_inode *nfsi = NFS_I(inode);
325 struct nfs_server *server = NFS_SERVER(inode);
326 struct nfs_delegation *delegation;
327
328 delegation = nfs_start_delegation_return(nfsi);
329 if (delegation == NULL)
330 return NULL;
331 return nfs_detach_delegation(nfsi, delegation, server);
332}
333
334static void
335nfs_update_inplace_delegation(struct nfs_delegation *delegation,
336 const struct nfs_delegation *update)
337{
338 if (nfs4_stateid_is_newer(&update->stateid, &delegation->stateid)) {
339 delegation->stateid.seqid = update->stateid.seqid;
340 smp_wmb();
341 delegation->type = update->type;
342 }
343}
344
345/**
346 * nfs_inode_set_delegation - set up a delegation on an inode
347 * @inode: inode to which delegation applies
348 * @cred: cred to use for subsequent delegation processing
349 * @type: delegation type
350 * @stateid: delegation stateid
351 * @pagemod_limit: write delegation "space_limit"
352 *
353 * Returns zero on success, or a negative errno value.
354 */
355int nfs_inode_set_delegation(struct inode *inode, const struct cred *cred,
356 fmode_t type,
357 const nfs4_stateid *stateid,
358 unsigned long pagemod_limit)
359{
360 struct nfs_server *server = NFS_SERVER(inode);
361 struct nfs_client *clp = server->nfs_client;
362 struct nfs_inode *nfsi = NFS_I(inode);
363 struct nfs_delegation *delegation, *old_delegation;
364 struct nfs_delegation *freeme = NULL;
365 int status = 0;
366
367 delegation = kmalloc(sizeof(*delegation), GFP_NOFS);
368 if (delegation == NULL)
369 return -ENOMEM;
370 nfs4_stateid_copy(&delegation->stateid, stateid);
371 delegation->type = type;
372 delegation->pagemod_limit = pagemod_limit;
373 delegation->change_attr = inode_peek_iversion_raw(inode);
374 delegation->cred = get_cred(cred);
375 delegation->inode = inode;
376 delegation->flags = 1<<NFS_DELEGATION_REFERENCED;
377 spin_lock_init(&delegation->lock);
378
379 spin_lock(&clp->cl_lock);
380 old_delegation = rcu_dereference_protected(nfsi->delegation,
381 lockdep_is_held(&clp->cl_lock));
382 if (old_delegation != NULL) {
383 /* Is this an update of the existing delegation? */
384 if (nfs4_stateid_match_other(&old_delegation->stateid,
385 &delegation->stateid)) {
386 nfs_update_inplace_delegation(old_delegation,
387 delegation);
388 goto out;
389 }
390 /*
391 * Deal with broken servers that hand out two
392 * delegations for the same file.
393 * Allow for upgrades to a WRITE delegation, but
394 * nothing else.
395 */
396 dfprintk(FILE, "%s: server %s handed out "
397 "a duplicate delegation!\n",
398 __func__, clp->cl_hostname);
399 if (delegation->type == old_delegation->type ||
400 !(delegation->type & FMODE_WRITE)) {
401 freeme = delegation;
402 delegation = NULL;
403 goto out;
404 }
405 if (test_and_set_bit(NFS_DELEGATION_RETURNING,
406 &old_delegation->flags))
407 goto out;
408 freeme = nfs_detach_delegation_locked(nfsi,
409 old_delegation, clp);
410 if (freeme == NULL)
411 goto out;
412 }
413 list_add_tail_rcu(&delegation->super_list, &server->delegations);
414 rcu_assign_pointer(nfsi->delegation, delegation);
415 delegation = NULL;
416
417 trace_nfs4_set_delegation(inode, type);
418
419 spin_lock(&inode->i_lock);
420 if (NFS_I(inode)->cache_validity & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_ATIME))
421 NFS_I(inode)->cache_validity |= NFS_INO_REVAL_FORCED;
422 spin_unlock(&inode->i_lock);
423out:
424 spin_unlock(&clp->cl_lock);
425 if (delegation != NULL)
426 nfs_free_delegation(delegation);
427 if (freeme != NULL)
428 nfs_do_return_delegation(inode, freeme, 0);
429 return status;
430}
431
432/*
433 * Basic procedure for returning a delegation to the server
434 */
435static int nfs_end_delegation_return(struct inode *inode, struct nfs_delegation *delegation, int issync)
436{
437 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
438 struct nfs_inode *nfsi = NFS_I(inode);
439 int err = 0;
440
441 if (delegation == NULL)
442 return 0;
443 do {
444 if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags))
445 break;
446 err = nfs_delegation_claim_opens(inode, &delegation->stateid,
447 delegation->type);
448 if (!issync || err != -EAGAIN)
449 break;
450 /*
451 * Guard against state recovery
452 */
453 err = nfs4_wait_clnt_recover(clp);
454 } while (err == 0);
455
456 if (err) {
457 nfs_abort_delegation_return(delegation, clp);
458 goto out;
459 }
460 if (!nfs_detach_delegation(nfsi, delegation, NFS_SERVER(inode)))
461 goto out;
462
463 err = nfs_do_return_delegation(inode, delegation, issync);
464out:
465 return err;
466}
467
468static bool nfs_delegation_need_return(struct nfs_delegation *delegation)
469{
470 bool ret = false;
471
472 if (test_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
473 goto out;
474 if (test_and_clear_bit(NFS_DELEGATION_RETURN, &delegation->flags))
475 ret = true;
476 if (test_and_clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags) && !ret) {
477 struct inode *inode;
478
479 spin_lock(&delegation->lock);
480 inode = delegation->inode;
481 if (inode && list_empty(&NFS_I(inode)->open_files))
482 ret = true;
483 spin_unlock(&delegation->lock);
484 }
485out:
486 return ret;
487}
488
489/**
490 * nfs_client_return_marked_delegations - return previously marked delegations
491 * @clp: nfs_client to process
492 *
493 * Note that this function is designed to be called by the state
494 * manager thread. For this reason, it cannot flush the dirty data,
495 * since that could deadlock in case of a state recovery error.
496 *
497 * Returns zero on success, or a negative errno value.
498 */
499int nfs_client_return_marked_delegations(struct nfs_client *clp)
500{
501 struct nfs_delegation *delegation;
502 struct nfs_delegation *prev;
503 struct nfs_server *server;
504 struct inode *inode;
505 struct inode *place_holder = NULL;
506 struct nfs_delegation *place_holder_deleg = NULL;
507 int err = 0;
508
509restart:
510 /*
511 * To avoid quadratic looping we hold a reference
512 * to an inode place_holder. Each time we restart, we
513 * list nfs_servers from the server of that inode, and
514 * delegation in the server from the delegations of that
515 * inode.
516 * prev is an RCU-protected pointer to a delegation which
517 * wasn't marked for return and might be a good choice for
518 * the next place_holder.
519 */
520 rcu_read_lock();
521 prev = NULL;
522 if (place_holder)
523 server = NFS_SERVER(place_holder);
524 else
525 server = list_entry_rcu(clp->cl_superblocks.next,
526 struct nfs_server, client_link);
527 list_for_each_entry_from_rcu(server, &clp->cl_superblocks, client_link) {
528 delegation = NULL;
529 if (place_holder && server == NFS_SERVER(place_holder))
530 delegation = rcu_dereference(NFS_I(place_holder)->delegation);
531 if (!delegation || delegation != place_holder_deleg)
532 delegation = list_entry_rcu(server->delegations.next,
533 struct nfs_delegation, super_list);
534 list_for_each_entry_from_rcu(delegation, &server->delegations, super_list) {
535 struct inode *to_put = NULL;
536
537 if (!nfs_delegation_need_return(delegation)) {
538 prev = delegation;
539 continue;
540 }
541 if (!nfs_sb_active(server->super))
542 break; /* continue in outer loop */
543
544 if (prev) {
545 struct inode *tmp;
546
547 tmp = nfs_delegation_grab_inode(prev);
548 if (tmp) {
549 to_put = place_holder;
550 place_holder = tmp;
551 place_holder_deleg = prev;
552 }
553 }
554
555 inode = nfs_delegation_grab_inode(delegation);
556 if (inode == NULL) {
557 rcu_read_unlock();
558 if (to_put)
559 iput(to_put);
560 nfs_sb_deactive(server->super);
561 goto restart;
562 }
563 delegation = nfs_start_delegation_return_locked(NFS_I(inode));
564 rcu_read_unlock();
565
566 if (to_put)
567 iput(to_put);
568
569 err = nfs_end_delegation_return(inode, delegation, 0);
570 iput(inode);
571 nfs_sb_deactive(server->super);
572 cond_resched();
573 if (!err)
574 goto restart;
575 set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
576 if (place_holder)
577 iput(place_holder);
578 return err;
579 }
580 }
581 rcu_read_unlock();
582 if (place_holder)
583 iput(place_holder);
584 return 0;
585}
586
587/**
588 * nfs_inode_return_delegation_noreclaim - return delegation, don't reclaim opens
589 * @inode: inode to process
590 *
591 * Does not protect against delegation reclaims, therefore really only safe
592 * to be called from nfs4_clear_inode().
593 */
594void nfs_inode_return_delegation_noreclaim(struct inode *inode)
595{
596 struct nfs_delegation *delegation;
597
598 delegation = nfs_inode_detach_delegation(inode);
599 if (delegation != NULL)
600 nfs_do_return_delegation(inode, delegation, 1);
601}
602
603/**
604 * nfs_inode_return_delegation - synchronously return a delegation
605 * @inode: inode to process
606 *
607 * This routine will always flush any dirty data to disk on the
608 * assumption that if we need to return the delegation, then
609 * we should stop caching.
610 *
611 * Returns zero on success, or a negative errno value.
612 */
613int nfs4_inode_return_delegation(struct inode *inode)
614{
615 struct nfs_inode *nfsi = NFS_I(inode);
616 struct nfs_delegation *delegation;
617 int err = 0;
618
619 nfs_wb_all(inode);
620 delegation = nfs_start_delegation_return(nfsi);
621 if (delegation != NULL)
622 err = nfs_end_delegation_return(inode, delegation, 1);
623 return err;
624}
625
626/**
627 * nfs4_inode_make_writeable
628 * @inode: pointer to inode
629 *
630 * Make the inode writeable by returning the delegation if necessary
631 *
632 * Returns zero on success, or a negative errno value.
633 */
634int nfs4_inode_make_writeable(struct inode *inode)
635{
636 if (!nfs4_has_session(NFS_SERVER(inode)->nfs_client) ||
637 !nfs4_check_delegation(inode, FMODE_WRITE))
638 return nfs4_inode_return_delegation(inode);
639 return 0;
640}
641
642static void nfs_mark_return_if_closed_delegation(struct nfs_server *server,
643 struct nfs_delegation *delegation)
644{
645 set_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags);
646 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
647}
648
649static void nfs_mark_return_delegation(struct nfs_server *server,
650 struct nfs_delegation *delegation)
651{
652 set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
653 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
654}
655
656static bool nfs_server_mark_return_all_delegations(struct nfs_server *server)
657{
658 struct nfs_delegation *delegation;
659 bool ret = false;
660
661 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
662 nfs_mark_return_delegation(server, delegation);
663 ret = true;
664 }
665 return ret;
666}
667
668static void nfs_client_mark_return_all_delegations(struct nfs_client *clp)
669{
670 struct nfs_server *server;
671
672 rcu_read_lock();
673 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
674 nfs_server_mark_return_all_delegations(server);
675 rcu_read_unlock();
676}
677
678static void nfs_delegation_run_state_manager(struct nfs_client *clp)
679{
680 if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state))
681 nfs4_schedule_state_manager(clp);
682}
683
684/**
685 * nfs_expire_all_delegations
686 * @clp: client to process
687 *
688 */
689void nfs_expire_all_delegations(struct nfs_client *clp)
690{
691 nfs_client_mark_return_all_delegations(clp);
692 nfs_delegation_run_state_manager(clp);
693}
694
695/**
696 * nfs_super_return_all_delegations - return delegations for one superblock
697 * @server: pointer to nfs_server to process
698 *
699 */
700void nfs_server_return_all_delegations(struct nfs_server *server)
701{
702 struct nfs_client *clp = server->nfs_client;
703 bool need_wait;
704
705 if (clp == NULL)
706 return;
707
708 rcu_read_lock();
709 need_wait = nfs_server_mark_return_all_delegations(server);
710 rcu_read_unlock();
711
712 if (need_wait) {
713 nfs4_schedule_state_manager(clp);
714 nfs4_wait_clnt_recover(clp);
715 }
716}
717
718static void nfs_mark_return_unused_delegation_types(struct nfs_server *server,
719 fmode_t flags)
720{
721 struct nfs_delegation *delegation;
722
723 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
724 if ((delegation->type == (FMODE_READ|FMODE_WRITE)) && !(flags & FMODE_WRITE))
725 continue;
726 if (delegation->type & flags)
727 nfs_mark_return_if_closed_delegation(server, delegation);
728 }
729}
730
731static void nfs_client_mark_return_unused_delegation_types(struct nfs_client *clp,
732 fmode_t flags)
733{
734 struct nfs_server *server;
735
736 rcu_read_lock();
737 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
738 nfs_mark_return_unused_delegation_types(server, flags);
739 rcu_read_unlock();
740}
741
742static void nfs_mark_delegation_revoked(struct nfs_server *server,
743 struct nfs_delegation *delegation)
744{
745 set_bit(NFS_DELEGATION_REVOKED, &delegation->flags);
746 delegation->stateid.type = NFS4_INVALID_STATEID_TYPE;
747 nfs_mark_return_delegation(server, delegation);
748}
749
750static bool nfs_revoke_delegation(struct inode *inode,
751 const nfs4_stateid *stateid)
752{
753 struct nfs_delegation *delegation;
754 nfs4_stateid tmp;
755 bool ret = false;
756
757 rcu_read_lock();
758 delegation = rcu_dereference(NFS_I(inode)->delegation);
759 if (delegation == NULL)
760 goto out;
761 if (stateid == NULL) {
762 nfs4_stateid_copy(&tmp, &delegation->stateid);
763 stateid = &tmp;
764 } else if (!nfs4_stateid_match(stateid, &delegation->stateid))
765 goto out;
766 nfs_mark_delegation_revoked(NFS_SERVER(inode), delegation);
767 ret = true;
768out:
769 rcu_read_unlock();
770 if (ret)
771 nfs_inode_find_state_and_recover(inode, stateid);
772 return ret;
773}
774
775void nfs_remove_bad_delegation(struct inode *inode,
776 const nfs4_stateid *stateid)
777{
778 struct nfs_delegation *delegation;
779
780 if (!nfs_revoke_delegation(inode, stateid))
781 return;
782 delegation = nfs_inode_detach_delegation(inode);
783 if (delegation)
784 nfs_free_delegation(delegation);
785}
786EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation);
787
788/**
789 * nfs_expire_unused_delegation_types
790 * @clp: client to process
791 * @flags: delegation types to expire
792 *
793 */
794void nfs_expire_unused_delegation_types(struct nfs_client *clp, fmode_t flags)
795{
796 nfs_client_mark_return_unused_delegation_types(clp, flags);
797 nfs_delegation_run_state_manager(clp);
798}
799
800static void nfs_mark_return_unreferenced_delegations(struct nfs_server *server)
801{
802 struct nfs_delegation *delegation;
803
804 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
805 if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags))
806 continue;
807 nfs_mark_return_if_closed_delegation(server, delegation);
808 }
809}
810
811/**
812 * nfs_expire_unreferenced_delegations - Eliminate unused delegations
813 * @clp: nfs_client to process
814 *
815 */
816void nfs_expire_unreferenced_delegations(struct nfs_client *clp)
817{
818 struct nfs_server *server;
819
820 rcu_read_lock();
821 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
822 nfs_mark_return_unreferenced_delegations(server);
823 rcu_read_unlock();
824
825 nfs_delegation_run_state_manager(clp);
826}
827
828/**
829 * nfs_async_inode_return_delegation - asynchronously return a delegation
830 * @inode: inode to process
831 * @stateid: state ID information
832 *
833 * Returns zero on success, or a negative errno value.
834 */
835int nfs_async_inode_return_delegation(struct inode *inode,
836 const nfs4_stateid *stateid)
837{
838 struct nfs_server *server = NFS_SERVER(inode);
839 struct nfs_client *clp = server->nfs_client;
840 struct nfs_delegation *delegation;
841
842 rcu_read_lock();
843 delegation = rcu_dereference(NFS_I(inode)->delegation);
844 if (delegation == NULL)
845 goto out_enoent;
846 if (stateid != NULL &&
847 !clp->cl_mvops->match_stateid(&delegation->stateid, stateid))
848 goto out_enoent;
849 nfs_mark_return_delegation(server, delegation);
850 rcu_read_unlock();
851
852 nfs_delegation_run_state_manager(clp);
853 return 0;
854out_enoent:
855 rcu_read_unlock();
856 return -ENOENT;
857}
858
859static struct inode *
860nfs_delegation_find_inode_server(struct nfs_server *server,
861 const struct nfs_fh *fhandle)
862{
863 struct nfs_delegation *delegation;
864 struct inode *freeme, *res = NULL;
865
866 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
867 spin_lock(&delegation->lock);
868 if (delegation->inode != NULL &&
869 nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
870 freeme = igrab(delegation->inode);
871 if (freeme && nfs_sb_active(freeme->i_sb))
872 res = freeme;
873 spin_unlock(&delegation->lock);
874 if (res != NULL)
875 return res;
876 if (freeme) {
877 rcu_read_unlock();
878 iput(freeme);
879 rcu_read_lock();
880 }
881 return ERR_PTR(-EAGAIN);
882 }
883 spin_unlock(&delegation->lock);
884 }
885 return ERR_PTR(-ENOENT);
886}
887
888/**
889 * nfs_delegation_find_inode - retrieve the inode associated with a delegation
890 * @clp: client state handle
891 * @fhandle: filehandle from a delegation recall
892 *
893 * Returns pointer to inode matching "fhandle," or NULL if a matching inode
894 * cannot be found.
895 */
896struct inode *nfs_delegation_find_inode(struct nfs_client *clp,
897 const struct nfs_fh *fhandle)
898{
899 struct nfs_server *server;
900 struct inode *res;
901
902 rcu_read_lock();
903 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
904 res = nfs_delegation_find_inode_server(server, fhandle);
905 if (res != ERR_PTR(-ENOENT)) {
906 rcu_read_unlock();
907 return res;
908 }
909 }
910 rcu_read_unlock();
911 return ERR_PTR(-ENOENT);
912}
913
914static void nfs_delegation_mark_reclaim_server(struct nfs_server *server)
915{
916 struct nfs_delegation *delegation;
917
918 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
919 /*
920 * If the delegation may have been admin revoked, then we
921 * cannot reclaim it.
922 */
923 if (test_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags))
924 continue;
925 set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
926 }
927}
928
929/**
930 * nfs_delegation_mark_reclaim - mark all delegations as needing to be reclaimed
931 * @clp: nfs_client to process
932 *
933 */
934void nfs_delegation_mark_reclaim(struct nfs_client *clp)
935{
936 struct nfs_server *server;
937
938 rcu_read_lock();
939 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
940 nfs_delegation_mark_reclaim_server(server);
941 rcu_read_unlock();
942}
943
944/**
945 * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done
946 * @clp: nfs_client to process
947 *
948 */
949void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
950{
951 struct nfs_delegation *delegation;
952 struct nfs_server *server;
953 struct inode *inode;
954
955restart:
956 rcu_read_lock();
957 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
958 list_for_each_entry_rcu(delegation, &server->delegations,
959 super_list) {
960 if (test_bit(NFS_DELEGATION_INODE_FREEING,
961 &delegation->flags) ||
962 test_bit(NFS_DELEGATION_RETURNING,
963 &delegation->flags) ||
964 test_bit(NFS_DELEGATION_NEED_RECLAIM,
965 &delegation->flags) == 0)
966 continue;
967 if (!nfs_sb_active(server->super))
968 break; /* continue in outer loop */
969 inode = nfs_delegation_grab_inode(delegation);
970 if (inode == NULL) {
971 rcu_read_unlock();
972 nfs_sb_deactive(server->super);
973 goto restart;
974 }
975 delegation = nfs_start_delegation_return_locked(NFS_I(inode));
976 rcu_read_unlock();
977 if (delegation != NULL) {
978 delegation = nfs_detach_delegation(NFS_I(inode),
979 delegation, server);
980 if (delegation != NULL)
981 nfs_free_delegation(delegation);
982 }
983 iput(inode);
984 nfs_sb_deactive(server->super);
985 cond_resched();
986 goto restart;
987 }
988 }
989 rcu_read_unlock();
990}
991
992static inline bool nfs4_server_rebooted(const struct nfs_client *clp)
993{
994 return (clp->cl_state & (BIT(NFS4CLNT_CHECK_LEASE) |
995 BIT(NFS4CLNT_LEASE_EXPIRED) |
996 BIT(NFS4CLNT_SESSION_RESET))) != 0;
997}
998
999static void nfs_mark_test_expired_delegation(struct nfs_server *server,
1000 struct nfs_delegation *delegation)
1001{
1002 if (delegation->stateid.type == NFS4_INVALID_STATEID_TYPE)
1003 return;
1004 clear_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
1005 set_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags);
1006 set_bit(NFS4CLNT_DELEGATION_EXPIRED, &server->nfs_client->cl_state);
1007}
1008
1009static void nfs_inode_mark_test_expired_delegation(struct nfs_server *server,
1010 struct inode *inode)
1011{
1012 struct nfs_delegation *delegation;
1013
1014 rcu_read_lock();
1015 delegation = rcu_dereference(NFS_I(inode)->delegation);
1016 if (delegation)
1017 nfs_mark_test_expired_delegation(server, delegation);
1018 rcu_read_unlock();
1019
1020}
1021
1022static void nfs_delegation_mark_test_expired_server(struct nfs_server *server)
1023{
1024 struct nfs_delegation *delegation;
1025
1026 list_for_each_entry_rcu(delegation, &server->delegations, super_list)
1027 nfs_mark_test_expired_delegation(server, delegation);
1028}
1029
1030/**
1031 * nfs_mark_test_expired_all_delegations - mark all delegations for testing
1032 * @clp: nfs_client to process
1033 *
1034 * Iterates through all the delegations associated with this server and
1035 * marks them as needing to be checked for validity.
1036 */
1037void nfs_mark_test_expired_all_delegations(struct nfs_client *clp)
1038{
1039 struct nfs_server *server;
1040
1041 rcu_read_lock();
1042 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1043 nfs_delegation_mark_test_expired_server(server);
1044 rcu_read_unlock();
1045}
1046
1047/**
1048 * nfs_test_expired_all_delegations - test all delegations for a client
1049 * @clp: nfs_client to process
1050 *
1051 * Helper for handling "recallable state revoked" status from server.
1052 */
1053void nfs_test_expired_all_delegations(struct nfs_client *clp)
1054{
1055 nfs_mark_test_expired_all_delegations(clp);
1056 nfs4_schedule_state_manager(clp);
1057}
1058
1059static void
1060nfs_delegation_test_free_expired(struct inode *inode,
1061 nfs4_stateid *stateid,
1062 const struct cred *cred)
1063{
1064 struct nfs_server *server = NFS_SERVER(inode);
1065 const struct nfs4_minor_version_ops *ops = server->nfs_client->cl_mvops;
1066 int status;
1067
1068 if (!cred)
1069 return;
1070 status = ops->test_and_free_expired(server, stateid, cred);
1071 if (status == -NFS4ERR_EXPIRED || status == -NFS4ERR_BAD_STATEID)
1072 nfs_remove_bad_delegation(inode, stateid);
1073}
1074
1075/**
1076 * nfs_reap_expired_delegations - reap expired delegations
1077 * @clp: nfs_client to process
1078 *
1079 * Iterates through all the delegations associated with this server and
1080 * checks if they have may have been revoked. This function is usually
1081 * expected to be called in cases where the server may have lost its
1082 * lease.
1083 */
1084void nfs_reap_expired_delegations(struct nfs_client *clp)
1085{
1086 struct nfs_delegation *delegation;
1087 struct nfs_server *server;
1088 struct inode *inode;
1089 const struct cred *cred;
1090 nfs4_stateid stateid;
1091
1092restart:
1093 rcu_read_lock();
1094 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
1095 list_for_each_entry_rcu(delegation, &server->delegations,
1096 super_list) {
1097 if (test_bit(NFS_DELEGATION_INODE_FREEING,
1098 &delegation->flags) ||
1099 test_bit(NFS_DELEGATION_RETURNING,
1100 &delegation->flags) ||
1101 test_bit(NFS_DELEGATION_TEST_EXPIRED,
1102 &delegation->flags) == 0)
1103 continue;
1104 if (!nfs_sb_active(server->super))
1105 break; /* continue in outer loop */
1106 inode = nfs_delegation_grab_inode(delegation);
1107 if (inode == NULL) {
1108 rcu_read_unlock();
1109 nfs_sb_deactive(server->super);
1110 goto restart;
1111 }
1112 cred = get_cred_rcu(delegation->cred);
1113 nfs4_stateid_copy(&stateid, &delegation->stateid);
1114 clear_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags);
1115 rcu_read_unlock();
1116 nfs_delegation_test_free_expired(inode, &stateid, cred);
1117 put_cred(cred);
1118 if (nfs4_server_rebooted(clp)) {
1119 nfs_inode_mark_test_expired_delegation(server,inode);
1120 iput(inode);
1121 nfs_sb_deactive(server->super);
1122 return;
1123 }
1124 iput(inode);
1125 nfs_sb_deactive(server->super);
1126 cond_resched();
1127 goto restart;
1128 }
1129 }
1130 rcu_read_unlock();
1131}
1132
1133void nfs_inode_find_delegation_state_and_recover(struct inode *inode,
1134 const nfs4_stateid *stateid)
1135{
1136 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
1137 struct nfs_delegation *delegation;
1138 bool found = false;
1139
1140 rcu_read_lock();
1141 delegation = rcu_dereference(NFS_I(inode)->delegation);
1142 if (delegation &&
1143 nfs4_stateid_match_other(&delegation->stateid, stateid)) {
1144 nfs_mark_test_expired_delegation(NFS_SERVER(inode), delegation);
1145 found = true;
1146 }
1147 rcu_read_unlock();
1148 if (found)
1149 nfs4_schedule_state_manager(clp);
1150}
1151
1152/**
1153 * nfs_delegations_present - check for existence of delegations
1154 * @clp: client state handle
1155 *
1156 * Returns one if there are any nfs_delegation structures attached
1157 * to this nfs_client.
1158 */
1159int nfs_delegations_present(struct nfs_client *clp)
1160{
1161 struct nfs_server *server;
1162 int ret = 0;
1163
1164 rcu_read_lock();
1165 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1166 if (!list_empty(&server->delegations)) {
1167 ret = 1;
1168 break;
1169 }
1170 rcu_read_unlock();
1171 return ret;
1172}
1173
1174/**
1175 * nfs4_refresh_delegation_stateid - Update delegation stateid seqid
1176 * @dst: stateid to refresh
1177 * @inode: inode to check
1178 *
1179 * Returns "true" and updates "dst->seqid" * if inode had a delegation
1180 * that matches our delegation stateid. Otherwise "false" is returned.
1181 */
1182bool nfs4_refresh_delegation_stateid(nfs4_stateid *dst, struct inode *inode)
1183{
1184 struct nfs_delegation *delegation;
1185 bool ret = false;
1186 if (!inode)
1187 goto out;
1188
1189 rcu_read_lock();
1190 delegation = rcu_dereference(NFS_I(inode)->delegation);
1191 if (delegation != NULL &&
1192 nfs4_stateid_match_other(dst, &delegation->stateid)) {
1193 dst->seqid = delegation->stateid.seqid;
1194 ret = true;
1195 }
1196 rcu_read_unlock();
1197out:
1198 return ret;
1199}
1200
1201/**
1202 * nfs4_copy_delegation_stateid - Copy inode's state ID information
1203 * @inode: inode to check
1204 * @flags: delegation type requirement
1205 * @dst: stateid data structure to fill in
1206 * @cred: optional argument to retrieve credential
1207 *
1208 * Returns "true" and fills in "dst->data" * if inode had a delegation,
1209 * otherwise "false" is returned.
1210 */
1211bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags,
1212 nfs4_stateid *dst, const struct cred **cred)
1213{
1214 struct nfs_inode *nfsi = NFS_I(inode);
1215 struct nfs_delegation *delegation;
1216 bool ret;
1217
1218 flags &= FMODE_READ|FMODE_WRITE;
1219 rcu_read_lock();
1220 delegation = rcu_dereference(nfsi->delegation);
1221 ret = nfs4_is_valid_delegation(delegation, flags);
1222 if (ret) {
1223 nfs4_stateid_copy(dst, &delegation->stateid);
1224 nfs_mark_delegation_referenced(delegation);
1225 if (cred)
1226 *cred = get_cred(delegation->cred);
1227 }
1228 rcu_read_unlock();
1229 return ret;
1230}
1231
1232/**
1233 * nfs4_delegation_flush_on_close - Check if we must flush file on close
1234 * @inode: inode to check
1235 *
1236 * This function checks the number of outstanding writes to the file
1237 * against the delegation 'space_limit' field to see if
1238 * the spec requires us to flush the file on close.
1239 */
1240bool nfs4_delegation_flush_on_close(const struct inode *inode)
1241{
1242 struct nfs_inode *nfsi = NFS_I(inode);
1243 struct nfs_delegation *delegation;
1244 bool ret = true;
1245
1246 rcu_read_lock();
1247 delegation = rcu_dereference(nfsi->delegation);
1248 if (delegation == NULL || !(delegation->type & FMODE_WRITE))
1249 goto out;
1250 if (atomic_long_read(&nfsi->nrequests) < delegation->pagemod_limit)
1251 ret = false;
1252out:
1253 rcu_read_unlock();
1254 return ret;
1255}