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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
28#define NFS_DEFAULT_DELEGATION_WATERMARK (5000U)
29
30static atomic_long_t nfs_active_delegations;
31static unsigned nfs_delegation_watermark = NFS_DEFAULT_DELEGATION_WATERMARK;
32
33static void __nfs_free_delegation(struct nfs_delegation *delegation)
34{
35 put_cred(delegation->cred);
36 delegation->cred = NULL;
37 kfree_rcu(delegation, rcu);
38}
39
40static void nfs_mark_delegation_revoked(struct nfs_delegation *delegation)
41{
42 if (!test_and_set_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) {
43 delegation->stateid.type = NFS4_INVALID_STATEID_TYPE;
44 atomic_long_dec(&nfs_active_delegations);
45 if (!test_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
46 nfs_clear_verifier_delegated(delegation->inode);
47 }
48}
49
50static struct nfs_delegation *nfs_get_delegation(struct nfs_delegation *delegation)
51{
52 refcount_inc(&delegation->refcount);
53 return delegation;
54}
55
56static void nfs_put_delegation(struct nfs_delegation *delegation)
57{
58 if (refcount_dec_and_test(&delegation->refcount))
59 __nfs_free_delegation(delegation);
60}
61
62static void nfs_free_delegation(struct nfs_delegation *delegation)
63{
64 nfs_mark_delegation_revoked(delegation);
65 nfs_put_delegation(delegation);
66}
67
68/**
69 * nfs_mark_delegation_referenced - set delegation's REFERENCED flag
70 * @delegation: delegation to process
71 *
72 */
73void nfs_mark_delegation_referenced(struct nfs_delegation *delegation)
74{
75 set_bit(NFS_DELEGATION_REFERENCED, &delegation->flags);
76}
77
78static void nfs_mark_return_delegation(struct nfs_server *server,
79 struct nfs_delegation *delegation)
80{
81 set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
82 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
83}
84
85static bool
86nfs4_is_valid_delegation(const struct nfs_delegation *delegation,
87 fmode_t flags)
88{
89 if (delegation != NULL && (delegation->type & flags) == flags &&
90 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) &&
91 !test_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
92 return true;
93 return false;
94}
95
96struct nfs_delegation *nfs4_get_valid_delegation(const struct inode *inode)
97{
98 struct nfs_delegation *delegation;
99
100 delegation = rcu_dereference(NFS_I(inode)->delegation);
101 if (nfs4_is_valid_delegation(delegation, 0))
102 return delegation;
103 return NULL;
104}
105
106static int
107nfs4_do_check_delegation(struct inode *inode, fmode_t flags, bool mark)
108{
109 struct nfs_delegation *delegation;
110 int ret = 0;
111
112 flags &= FMODE_READ|FMODE_WRITE;
113 rcu_read_lock();
114 delegation = rcu_dereference(NFS_I(inode)->delegation);
115 if (nfs4_is_valid_delegation(delegation, flags)) {
116 if (mark)
117 nfs_mark_delegation_referenced(delegation);
118 ret = 1;
119 }
120 rcu_read_unlock();
121 return ret;
122}
123/**
124 * nfs4_have_delegation - check if inode has a delegation, mark it
125 * NFS_DELEGATION_REFERENCED if there is one.
126 * @inode: inode to check
127 * @flags: delegation types to check for
128 *
129 * Returns one if inode has the indicated delegation, otherwise zero.
130 */
131int nfs4_have_delegation(struct inode *inode, fmode_t flags)
132{
133 return nfs4_do_check_delegation(inode, flags, true);
134}
135
136/*
137 * nfs4_check_delegation - check if inode has a delegation, do not mark
138 * NFS_DELEGATION_REFERENCED if it has one.
139 */
140int nfs4_check_delegation(struct inode *inode, fmode_t flags)
141{
142 return nfs4_do_check_delegation(inode, flags, false);
143}
144
145static int nfs_delegation_claim_locks(struct nfs4_state *state, const nfs4_stateid *stateid)
146{
147 struct inode *inode = state->inode;
148 struct file_lock *fl;
149 struct file_lock_context *flctx = locks_inode_context(inode);
150 struct list_head *list;
151 int status = 0;
152
153 if (flctx == NULL)
154 goto out;
155
156 list = &flctx->flc_posix;
157 spin_lock(&flctx->flc_lock);
158restart:
159 for_each_file_lock(fl, list) {
160 if (nfs_file_open_context(fl->c.flc_file)->state != state)
161 continue;
162 spin_unlock(&flctx->flc_lock);
163 status = nfs4_lock_delegation_recall(fl, state, stateid);
164 if (status < 0)
165 goto out;
166 spin_lock(&flctx->flc_lock);
167 }
168 if (list == &flctx->flc_posix) {
169 list = &flctx->flc_flock;
170 goto restart;
171 }
172 spin_unlock(&flctx->flc_lock);
173out:
174 return status;
175}
176
177static int nfs_delegation_claim_opens(struct inode *inode,
178 const nfs4_stateid *stateid, fmode_t type)
179{
180 struct nfs_inode *nfsi = NFS_I(inode);
181 struct nfs_open_context *ctx;
182 struct nfs4_state_owner *sp;
183 struct nfs4_state *state;
184 int err;
185
186again:
187 rcu_read_lock();
188 list_for_each_entry_rcu(ctx, &nfsi->open_files, list) {
189 state = ctx->state;
190 if (state == NULL)
191 continue;
192 if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
193 continue;
194 if (!nfs4_valid_open_stateid(state))
195 continue;
196 if (!nfs4_stateid_match(&state->stateid, stateid))
197 continue;
198 if (!get_nfs_open_context(ctx))
199 continue;
200 rcu_read_unlock();
201 sp = state->owner;
202 /* Block nfs4_proc_unlck */
203 mutex_lock(&sp->so_delegreturn_mutex);
204 err = nfs4_open_delegation_recall(ctx, state, stateid);
205 if (!err)
206 err = nfs_delegation_claim_locks(state, stateid);
207 mutex_unlock(&sp->so_delegreturn_mutex);
208 put_nfs_open_context(ctx);
209 if (err != 0)
210 return err;
211 goto again;
212 }
213 rcu_read_unlock();
214 return 0;
215}
216
217/**
218 * nfs_inode_reclaim_delegation - process a delegation reclaim request
219 * @inode: inode to process
220 * @cred: credential to use for request
221 * @type: delegation type
222 * @stateid: delegation stateid
223 * @pagemod_limit: write delegation "space_limit"
224 *
225 */
226void nfs_inode_reclaim_delegation(struct inode *inode, const struct cred *cred,
227 fmode_t type, const nfs4_stateid *stateid,
228 unsigned long pagemod_limit)
229{
230 struct nfs_delegation *delegation;
231 const struct cred *oldcred = NULL;
232
233 rcu_read_lock();
234 delegation = rcu_dereference(NFS_I(inode)->delegation);
235 if (delegation != NULL) {
236 spin_lock(&delegation->lock);
237 nfs4_stateid_copy(&delegation->stateid, stateid);
238 delegation->type = type;
239 delegation->pagemod_limit = pagemod_limit;
240 oldcred = delegation->cred;
241 delegation->cred = get_cred(cred);
242 clear_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
243 if (test_and_clear_bit(NFS_DELEGATION_REVOKED,
244 &delegation->flags))
245 atomic_long_inc(&nfs_active_delegations);
246 spin_unlock(&delegation->lock);
247 rcu_read_unlock();
248 put_cred(oldcred);
249 trace_nfs4_reclaim_delegation(inode, type);
250 } else {
251 rcu_read_unlock();
252 nfs_inode_set_delegation(inode, cred, type, stateid,
253 pagemod_limit);
254 }
255}
256
257static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync)
258{
259 const struct cred *cred;
260 int res = 0;
261
262 if (!test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) {
263 spin_lock(&delegation->lock);
264 cred = get_cred(delegation->cred);
265 spin_unlock(&delegation->lock);
266 res = nfs4_proc_delegreturn(inode, cred,
267 &delegation->stateid,
268 issync);
269 put_cred(cred);
270 }
271 return res;
272}
273
274static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation)
275{
276 struct inode *inode = NULL;
277
278 spin_lock(&delegation->lock);
279 if (delegation->inode != NULL)
280 inode = igrab(delegation->inode);
281 if (!inode)
282 set_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags);
283 spin_unlock(&delegation->lock);
284 return inode;
285}
286
287static struct nfs_delegation *
288nfs_start_delegation_return_locked(struct nfs_inode *nfsi)
289{
290 struct nfs_delegation *ret = NULL;
291 struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation);
292
293 if (delegation == NULL)
294 goto out;
295 spin_lock(&delegation->lock);
296 if (!test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) {
297 clear_bit(NFS_DELEGATION_RETURN_DELAYED, &delegation->flags);
298 /* Refcount matched in nfs_end_delegation_return() */
299 ret = nfs_get_delegation(delegation);
300 }
301 spin_unlock(&delegation->lock);
302 if (ret)
303 nfs_clear_verifier_delegated(&nfsi->vfs_inode);
304out:
305 return ret;
306}
307
308static struct nfs_delegation *
309nfs_start_delegation_return(struct nfs_inode *nfsi)
310{
311 struct nfs_delegation *delegation;
312
313 rcu_read_lock();
314 delegation = nfs_start_delegation_return_locked(nfsi);
315 rcu_read_unlock();
316 return delegation;
317}
318
319static void nfs_abort_delegation_return(struct nfs_delegation *delegation,
320 struct nfs_client *clp, int err)
321{
322
323 spin_lock(&delegation->lock);
324 clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
325 if (err == -EAGAIN) {
326 set_bit(NFS_DELEGATION_RETURN_DELAYED, &delegation->flags);
327 set_bit(NFS4CLNT_DELEGRETURN_DELAYED, &clp->cl_state);
328 }
329 spin_unlock(&delegation->lock);
330}
331
332static struct nfs_delegation *
333nfs_detach_delegation_locked(struct nfs_inode *nfsi,
334 struct nfs_delegation *delegation,
335 struct nfs_client *clp)
336{
337 struct nfs_delegation *deleg_cur =
338 rcu_dereference_protected(nfsi->delegation,
339 lockdep_is_held(&clp->cl_lock));
340
341 if (deleg_cur == NULL || delegation != deleg_cur)
342 return NULL;
343
344 spin_lock(&delegation->lock);
345 if (!delegation->inode) {
346 spin_unlock(&delegation->lock);
347 return NULL;
348 }
349 list_del_rcu(&delegation->super_list);
350 delegation->inode = NULL;
351 rcu_assign_pointer(nfsi->delegation, NULL);
352 spin_unlock(&delegation->lock);
353 return delegation;
354}
355
356static struct nfs_delegation *nfs_detach_delegation(struct nfs_inode *nfsi,
357 struct nfs_delegation *delegation,
358 struct nfs_server *server)
359{
360 struct nfs_client *clp = server->nfs_client;
361
362 spin_lock(&clp->cl_lock);
363 delegation = nfs_detach_delegation_locked(nfsi, delegation, clp);
364 spin_unlock(&clp->cl_lock);
365 return delegation;
366}
367
368static struct nfs_delegation *
369nfs_inode_detach_delegation(struct inode *inode)
370{
371 struct nfs_inode *nfsi = NFS_I(inode);
372 struct nfs_server *server = NFS_SERVER(inode);
373 struct nfs_delegation *delegation;
374
375 rcu_read_lock();
376 delegation = rcu_dereference(nfsi->delegation);
377 if (delegation != NULL)
378 delegation = nfs_detach_delegation(nfsi, delegation, server);
379 rcu_read_unlock();
380 return delegation;
381}
382
383static void
384nfs_update_delegation_cred(struct nfs_delegation *delegation,
385 const struct cred *cred)
386{
387 const struct cred *old;
388
389 if (cred_fscmp(delegation->cred, cred) != 0) {
390 old = xchg(&delegation->cred, get_cred(cred));
391 put_cred(old);
392 }
393}
394
395static void
396nfs_update_inplace_delegation(struct nfs_delegation *delegation,
397 const struct nfs_delegation *update)
398{
399 if (nfs4_stateid_is_newer(&update->stateid, &delegation->stateid)) {
400 delegation->stateid.seqid = update->stateid.seqid;
401 smp_wmb();
402 delegation->type = update->type;
403 delegation->pagemod_limit = update->pagemod_limit;
404 if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) {
405 delegation->change_attr = update->change_attr;
406 nfs_update_delegation_cred(delegation, update->cred);
407 /* smp_mb__before_atomic() is implicit due to xchg() */
408 clear_bit(NFS_DELEGATION_REVOKED, &delegation->flags);
409 atomic_long_inc(&nfs_active_delegations);
410 }
411 }
412}
413
414/**
415 * nfs_inode_set_delegation - set up a delegation on an inode
416 * @inode: inode to which delegation applies
417 * @cred: cred to use for subsequent delegation processing
418 * @type: delegation type
419 * @stateid: delegation stateid
420 * @pagemod_limit: write delegation "space_limit"
421 *
422 * Returns zero on success, or a negative errno value.
423 */
424int nfs_inode_set_delegation(struct inode *inode, const struct cred *cred,
425 fmode_t type,
426 const nfs4_stateid *stateid,
427 unsigned long pagemod_limit)
428{
429 struct nfs_server *server = NFS_SERVER(inode);
430 struct nfs_client *clp = server->nfs_client;
431 struct nfs_inode *nfsi = NFS_I(inode);
432 struct nfs_delegation *delegation, *old_delegation;
433 struct nfs_delegation *freeme = NULL;
434 int status = 0;
435
436 delegation = kmalloc(sizeof(*delegation), GFP_KERNEL_ACCOUNT);
437 if (delegation == NULL)
438 return -ENOMEM;
439 nfs4_stateid_copy(&delegation->stateid, stateid);
440 refcount_set(&delegation->refcount, 1);
441 delegation->type = type;
442 delegation->pagemod_limit = pagemod_limit;
443 delegation->change_attr = inode_peek_iversion_raw(inode);
444 delegation->cred = get_cred(cred);
445 delegation->inode = inode;
446 delegation->flags = 1<<NFS_DELEGATION_REFERENCED;
447 delegation->test_gen = 0;
448 spin_lock_init(&delegation->lock);
449
450 spin_lock(&clp->cl_lock);
451 old_delegation = rcu_dereference_protected(nfsi->delegation,
452 lockdep_is_held(&clp->cl_lock));
453 if (old_delegation == NULL)
454 goto add_new;
455 /* Is this an update of the existing delegation? */
456 if (nfs4_stateid_match_other(&old_delegation->stateid,
457 &delegation->stateid)) {
458 spin_lock(&old_delegation->lock);
459 nfs_update_inplace_delegation(old_delegation,
460 delegation);
461 spin_unlock(&old_delegation->lock);
462 goto out;
463 }
464 if (!test_bit(NFS_DELEGATION_REVOKED, &old_delegation->flags)) {
465 /*
466 * Deal with broken servers that hand out two
467 * delegations for the same file.
468 * Allow for upgrades to a WRITE delegation, but
469 * nothing else.
470 */
471 dfprintk(FILE, "%s: server %s handed out "
472 "a duplicate delegation!\n",
473 __func__, clp->cl_hostname);
474 if (delegation->type == old_delegation->type ||
475 !(delegation->type & FMODE_WRITE)) {
476 freeme = delegation;
477 delegation = NULL;
478 goto out;
479 }
480 if (test_and_set_bit(NFS_DELEGATION_RETURNING,
481 &old_delegation->flags))
482 goto out;
483 }
484 freeme = nfs_detach_delegation_locked(nfsi, old_delegation, clp);
485 if (freeme == NULL)
486 goto out;
487add_new:
488 /*
489 * If we didn't revalidate the change attribute before setting
490 * the delegation, then pre-emptively ask for a full attribute
491 * cache revalidation.
492 */
493 spin_lock(&inode->i_lock);
494 if (NFS_I(inode)->cache_validity & NFS_INO_INVALID_CHANGE)
495 nfs_set_cache_invalid(inode,
496 NFS_INO_INVALID_ATIME | NFS_INO_INVALID_CTIME |
497 NFS_INO_INVALID_MTIME | NFS_INO_INVALID_SIZE |
498 NFS_INO_INVALID_BLOCKS | NFS_INO_INVALID_NLINK |
499 NFS_INO_INVALID_OTHER | NFS_INO_INVALID_DATA |
500 NFS_INO_INVALID_ACCESS | NFS_INO_INVALID_ACL |
501 NFS_INO_INVALID_XATTR);
502 spin_unlock(&inode->i_lock);
503
504 list_add_tail_rcu(&delegation->super_list, &server->delegations);
505 rcu_assign_pointer(nfsi->delegation, delegation);
506 delegation = NULL;
507
508 atomic_long_inc(&nfs_active_delegations);
509
510 trace_nfs4_set_delegation(inode, type);
511out:
512 spin_unlock(&clp->cl_lock);
513 if (delegation != NULL)
514 __nfs_free_delegation(delegation);
515 if (freeme != NULL) {
516 nfs_do_return_delegation(inode, freeme, 0);
517 nfs_free_delegation(freeme);
518 }
519 return status;
520}
521
522/*
523 * Basic procedure for returning a delegation to the server
524 */
525static int nfs_end_delegation_return(struct inode *inode, struct nfs_delegation *delegation, int issync)
526{
527 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
528 unsigned int mode = O_WRONLY | O_RDWR;
529 int err = 0;
530
531 if (delegation == NULL)
532 return 0;
533
534 if (!issync)
535 mode |= O_NONBLOCK;
536 /* Recall of any remaining application leases */
537 err = break_lease(inode, mode);
538
539 while (err == 0) {
540 if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags))
541 break;
542 err = nfs_delegation_claim_opens(inode, &delegation->stateid,
543 delegation->type);
544 if (!issync || err != -EAGAIN)
545 break;
546 /*
547 * Guard against state recovery
548 */
549 err = nfs4_wait_clnt_recover(clp);
550 }
551
552 if (err) {
553 nfs_abort_delegation_return(delegation, clp, err);
554 goto out;
555 }
556
557 err = nfs_do_return_delegation(inode, delegation, issync);
558out:
559 /* Refcount matched in nfs_start_delegation_return_locked() */
560 nfs_put_delegation(delegation);
561 return err;
562}
563
564static bool nfs_delegation_need_return(struct nfs_delegation *delegation)
565{
566 bool ret = false;
567
568 if (test_and_clear_bit(NFS_DELEGATION_RETURN, &delegation->flags))
569 ret = true;
570 else if (test_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags)) {
571 struct inode *inode;
572
573 spin_lock(&delegation->lock);
574 inode = delegation->inode;
575 if (inode && list_empty(&NFS_I(inode)->open_files))
576 ret = true;
577 spin_unlock(&delegation->lock);
578 }
579 if (ret)
580 clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags);
581 if (test_bit(NFS_DELEGATION_RETURNING, &delegation->flags) ||
582 test_bit(NFS_DELEGATION_RETURN_DELAYED, &delegation->flags) ||
583 test_bit(NFS_DELEGATION_REVOKED, &delegation->flags))
584 ret = false;
585
586 return ret;
587}
588
589static int nfs_server_return_marked_delegations(struct nfs_server *server,
590 void __always_unused *data)
591{
592 struct nfs_delegation *delegation;
593 struct nfs_delegation *prev;
594 struct inode *inode;
595 struct inode *place_holder = NULL;
596 struct nfs_delegation *place_holder_deleg = NULL;
597 int err = 0;
598
599restart:
600 /*
601 * To avoid quadratic looping we hold a reference
602 * to an inode place_holder. Each time we restart, we
603 * list delegation in the server from the delegations
604 * of that inode.
605 * prev is an RCU-protected pointer to a delegation which
606 * wasn't marked for return and might be a good choice for
607 * the next place_holder.
608 */
609 prev = NULL;
610 delegation = NULL;
611 rcu_read_lock();
612 if (place_holder)
613 delegation = rcu_dereference(NFS_I(place_holder)->delegation);
614 if (!delegation || delegation != place_holder_deleg)
615 delegation = list_entry_rcu(server->delegations.next,
616 struct nfs_delegation, super_list);
617 list_for_each_entry_from_rcu(delegation, &server->delegations, super_list) {
618 struct inode *to_put = NULL;
619
620 if (test_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags))
621 continue;
622 if (!nfs_delegation_need_return(delegation)) {
623 if (nfs4_is_valid_delegation(delegation, 0))
624 prev = delegation;
625 continue;
626 }
627
628 if (prev) {
629 struct inode *tmp = nfs_delegation_grab_inode(prev);
630 if (tmp) {
631 to_put = place_holder;
632 place_holder = tmp;
633 place_holder_deleg = prev;
634 }
635 }
636
637 inode = nfs_delegation_grab_inode(delegation);
638 if (inode == NULL) {
639 rcu_read_unlock();
640 iput(to_put);
641 goto restart;
642 }
643 delegation = nfs_start_delegation_return_locked(NFS_I(inode));
644 rcu_read_unlock();
645
646 iput(to_put);
647
648 err = nfs_end_delegation_return(inode, delegation, 0);
649 iput(inode);
650 cond_resched();
651 if (!err)
652 goto restart;
653 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
654 goto out;
655 }
656 rcu_read_unlock();
657out:
658 iput(place_holder);
659 return err;
660}
661
662static bool nfs_server_clear_delayed_delegations(struct nfs_server *server)
663{
664 struct nfs_delegation *d;
665 bool ret = false;
666
667 list_for_each_entry_rcu (d, &server->delegations, super_list) {
668 if (!test_bit(NFS_DELEGATION_RETURN_DELAYED, &d->flags))
669 continue;
670 nfs_mark_return_delegation(server, d);
671 clear_bit(NFS_DELEGATION_RETURN_DELAYED, &d->flags);
672 ret = true;
673 }
674 return ret;
675}
676
677static bool nfs_client_clear_delayed_delegations(struct nfs_client *clp)
678{
679 struct nfs_server *server;
680 bool ret = false;
681
682 if (!test_and_clear_bit(NFS4CLNT_DELEGRETURN_DELAYED, &clp->cl_state))
683 goto out;
684 rcu_read_lock();
685 list_for_each_entry_rcu (server, &clp->cl_superblocks, client_link) {
686 if (nfs_server_clear_delayed_delegations(server))
687 ret = true;
688 }
689 rcu_read_unlock();
690out:
691 return ret;
692}
693
694/**
695 * nfs_client_return_marked_delegations - return previously marked delegations
696 * @clp: nfs_client to process
697 *
698 * Note that this function is designed to be called by the state
699 * manager thread. For this reason, it cannot flush the dirty data,
700 * since that could deadlock in case of a state recovery error.
701 *
702 * Returns zero on success, or a negative errno value.
703 */
704int nfs_client_return_marked_delegations(struct nfs_client *clp)
705{
706 int err = nfs_client_for_each_server(
707 clp, nfs_server_return_marked_delegations, NULL);
708 if (err)
709 return err;
710 /* If a return was delayed, sleep to prevent hard looping */
711 if (nfs_client_clear_delayed_delegations(clp))
712 ssleep(1);
713 return 0;
714}
715
716/**
717 * nfs_inode_evict_delegation - return delegation, don't reclaim opens
718 * @inode: inode to process
719 *
720 * Does not protect against delegation reclaims, therefore really only safe
721 * to be called from nfs4_clear_inode(). Guaranteed to always free
722 * the delegation structure.
723 */
724void nfs_inode_evict_delegation(struct inode *inode)
725{
726 struct nfs_delegation *delegation;
727
728 delegation = nfs_inode_detach_delegation(inode);
729 if (delegation != NULL) {
730 set_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
731 set_bit(NFS_DELEGATION_INODE_FREEING, &delegation->flags);
732 nfs_do_return_delegation(inode, delegation, 1);
733 nfs_free_delegation(delegation);
734 }
735}
736
737/**
738 * nfs4_inode_return_delegation - synchronously return a delegation
739 * @inode: inode to process
740 *
741 * This routine will always flush any dirty data to disk on the
742 * assumption that if we need to return the delegation, then
743 * we should stop caching.
744 *
745 * Returns zero on success, or a negative errno value.
746 */
747int nfs4_inode_return_delegation(struct inode *inode)
748{
749 struct nfs_inode *nfsi = NFS_I(inode);
750 struct nfs_delegation *delegation;
751
752 delegation = nfs_start_delegation_return(nfsi);
753 if (delegation != NULL) {
754 /* Synchronous recall of any application leases */
755 break_lease(inode, O_WRONLY | O_RDWR);
756 if (S_ISREG(inode->i_mode))
757 nfs_wb_all(inode);
758 return nfs_end_delegation_return(inode, delegation, 1);
759 }
760 return 0;
761}
762
763/**
764 * nfs4_inode_return_delegation_on_close - asynchronously return a delegation
765 * @inode: inode to process
766 *
767 * This routine is called on file close in order to determine if the
768 * inode delegation needs to be returned immediately.
769 */
770void nfs4_inode_return_delegation_on_close(struct inode *inode)
771{
772 struct nfs_delegation *delegation;
773 struct nfs_delegation *ret = NULL;
774
775 if (!inode)
776 return;
777 rcu_read_lock();
778 delegation = nfs4_get_valid_delegation(inode);
779 if (!delegation)
780 goto out;
781 if (test_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags) ||
782 atomic_long_read(&nfs_active_delegations) >= nfs_delegation_watermark) {
783 spin_lock(&delegation->lock);
784 if (delegation->inode &&
785 list_empty(&NFS_I(inode)->open_files) &&
786 !test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) {
787 clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags);
788 /* Refcount matched in nfs_end_delegation_return() */
789 ret = nfs_get_delegation(delegation);
790 }
791 spin_unlock(&delegation->lock);
792 if (ret)
793 nfs_clear_verifier_delegated(inode);
794 }
795out:
796 rcu_read_unlock();
797 nfs_end_delegation_return(inode, ret, 0);
798}
799
800/**
801 * nfs4_inode_make_writeable
802 * @inode: pointer to inode
803 *
804 * Make the inode writeable by returning the delegation if necessary
805 *
806 * Returns zero on success, or a negative errno value.
807 */
808int nfs4_inode_make_writeable(struct inode *inode)
809{
810 struct nfs_delegation *delegation;
811
812 rcu_read_lock();
813 delegation = nfs4_get_valid_delegation(inode);
814 if (delegation == NULL ||
815 (nfs4_has_session(NFS_SERVER(inode)->nfs_client) &&
816 (delegation->type & FMODE_WRITE))) {
817 rcu_read_unlock();
818 return 0;
819 }
820 rcu_read_unlock();
821 return nfs4_inode_return_delegation(inode);
822}
823
824static void nfs_mark_return_if_closed_delegation(struct nfs_server *server,
825 struct nfs_delegation *delegation)
826{
827 set_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags);
828 set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
829}
830
831static bool nfs_server_mark_return_all_delegations(struct nfs_server *server)
832{
833 struct nfs_delegation *delegation;
834 bool ret = false;
835
836 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
837 nfs_mark_return_delegation(server, delegation);
838 ret = true;
839 }
840 return ret;
841}
842
843static void nfs_client_mark_return_all_delegations(struct nfs_client *clp)
844{
845 struct nfs_server *server;
846
847 rcu_read_lock();
848 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
849 nfs_server_mark_return_all_delegations(server);
850 rcu_read_unlock();
851}
852
853static void nfs_delegation_run_state_manager(struct nfs_client *clp)
854{
855 if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state))
856 nfs4_schedule_state_manager(clp);
857}
858
859/**
860 * nfs_expire_all_delegations
861 * @clp: client to process
862 *
863 */
864void nfs_expire_all_delegations(struct nfs_client *clp)
865{
866 nfs_client_mark_return_all_delegations(clp);
867 nfs_delegation_run_state_manager(clp);
868}
869
870/**
871 * nfs_server_return_all_delegations - return delegations for one superblock
872 * @server: pointer to nfs_server to process
873 *
874 */
875void nfs_server_return_all_delegations(struct nfs_server *server)
876{
877 struct nfs_client *clp = server->nfs_client;
878 bool need_wait;
879
880 if (clp == NULL)
881 return;
882
883 rcu_read_lock();
884 need_wait = nfs_server_mark_return_all_delegations(server);
885 rcu_read_unlock();
886
887 if (need_wait) {
888 nfs4_schedule_state_manager(clp);
889 nfs4_wait_clnt_recover(clp);
890 }
891}
892
893static void nfs_mark_return_unused_delegation_types(struct nfs_server *server,
894 fmode_t flags)
895{
896 struct nfs_delegation *delegation;
897
898 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
899 if ((delegation->type == (FMODE_READ|FMODE_WRITE)) && !(flags & FMODE_WRITE))
900 continue;
901 if (delegation->type & flags)
902 nfs_mark_return_if_closed_delegation(server, delegation);
903 }
904}
905
906static void nfs_client_mark_return_unused_delegation_types(struct nfs_client *clp,
907 fmode_t flags)
908{
909 struct nfs_server *server;
910
911 rcu_read_lock();
912 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
913 nfs_mark_return_unused_delegation_types(server, flags);
914 rcu_read_unlock();
915}
916
917static void nfs_revoke_delegation(struct inode *inode,
918 const nfs4_stateid *stateid)
919{
920 struct nfs_delegation *delegation;
921 nfs4_stateid tmp;
922 bool ret = false;
923
924 rcu_read_lock();
925 delegation = rcu_dereference(NFS_I(inode)->delegation);
926 if (delegation == NULL)
927 goto out;
928 if (stateid == NULL) {
929 nfs4_stateid_copy(&tmp, &delegation->stateid);
930 stateid = &tmp;
931 } else {
932 if (!nfs4_stateid_match_other(stateid, &delegation->stateid))
933 goto out;
934 spin_lock(&delegation->lock);
935 if (stateid->seqid) {
936 if (nfs4_stateid_is_newer(&delegation->stateid, stateid)) {
937 spin_unlock(&delegation->lock);
938 goto out;
939 }
940 delegation->stateid.seqid = stateid->seqid;
941 }
942 spin_unlock(&delegation->lock);
943 }
944 nfs_mark_delegation_revoked(delegation);
945 ret = true;
946out:
947 rcu_read_unlock();
948 if (ret)
949 nfs_inode_find_state_and_recover(inode, stateid);
950}
951
952void nfs_remove_bad_delegation(struct inode *inode,
953 const nfs4_stateid *stateid)
954{
955 nfs_revoke_delegation(inode, stateid);
956}
957EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation);
958
959void nfs_delegation_mark_returned(struct inode *inode,
960 const nfs4_stateid *stateid)
961{
962 struct nfs_delegation *delegation;
963
964 if (!inode)
965 return;
966
967 rcu_read_lock();
968 delegation = rcu_dereference(NFS_I(inode)->delegation);
969 if (!delegation)
970 goto out_rcu_unlock;
971
972 spin_lock(&delegation->lock);
973 if (!nfs4_stateid_match_other(stateid, &delegation->stateid))
974 goto out_spin_unlock;
975 if (stateid->seqid) {
976 /* If delegation->stateid is newer, dont mark as returned */
977 if (nfs4_stateid_is_newer(&delegation->stateid, stateid))
978 goto out_clear_returning;
979 if (delegation->stateid.seqid != stateid->seqid)
980 delegation->stateid.seqid = stateid->seqid;
981 }
982
983 nfs_mark_delegation_revoked(delegation);
984
985out_clear_returning:
986 clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
987out_spin_unlock:
988 spin_unlock(&delegation->lock);
989out_rcu_unlock:
990 rcu_read_unlock();
991
992 nfs_inode_find_state_and_recover(inode, stateid);
993}
994
995/**
996 * nfs_expire_unused_delegation_types
997 * @clp: client to process
998 * @flags: delegation types to expire
999 *
1000 */
1001void nfs_expire_unused_delegation_types(struct nfs_client *clp, fmode_t flags)
1002{
1003 nfs_client_mark_return_unused_delegation_types(clp, flags);
1004 nfs_delegation_run_state_manager(clp);
1005}
1006
1007static void nfs_mark_return_unreferenced_delegations(struct nfs_server *server)
1008{
1009 struct nfs_delegation *delegation;
1010
1011 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
1012 if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags))
1013 continue;
1014 nfs_mark_return_if_closed_delegation(server, delegation);
1015 }
1016}
1017
1018/**
1019 * nfs_expire_unreferenced_delegations - Eliminate unused delegations
1020 * @clp: nfs_client to process
1021 *
1022 */
1023void nfs_expire_unreferenced_delegations(struct nfs_client *clp)
1024{
1025 struct nfs_server *server;
1026
1027 rcu_read_lock();
1028 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1029 nfs_mark_return_unreferenced_delegations(server);
1030 rcu_read_unlock();
1031
1032 nfs_delegation_run_state_manager(clp);
1033}
1034
1035/**
1036 * nfs_async_inode_return_delegation - asynchronously return a delegation
1037 * @inode: inode to process
1038 * @stateid: state ID information
1039 *
1040 * Returns zero on success, or a negative errno value.
1041 */
1042int nfs_async_inode_return_delegation(struct inode *inode,
1043 const nfs4_stateid *stateid)
1044{
1045 struct nfs_server *server = NFS_SERVER(inode);
1046 struct nfs_client *clp = server->nfs_client;
1047 struct nfs_delegation *delegation;
1048
1049 rcu_read_lock();
1050 delegation = nfs4_get_valid_delegation(inode);
1051 if (delegation == NULL)
1052 goto out_enoent;
1053 if (stateid != NULL &&
1054 !clp->cl_mvops->match_stateid(&delegation->stateid, stateid))
1055 goto out_enoent;
1056 nfs_mark_return_delegation(server, delegation);
1057 rcu_read_unlock();
1058
1059 /* If there are any application leases or delegations, recall them */
1060 break_lease(inode, O_WRONLY | O_RDWR | O_NONBLOCK);
1061
1062 nfs_delegation_run_state_manager(clp);
1063 return 0;
1064out_enoent:
1065 rcu_read_unlock();
1066 return -ENOENT;
1067}
1068
1069static struct inode *
1070nfs_delegation_find_inode_server(struct nfs_server *server,
1071 const struct nfs_fh *fhandle)
1072{
1073 struct nfs_delegation *delegation;
1074 struct super_block *freeme = NULL;
1075 struct inode *res = NULL;
1076
1077 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
1078 spin_lock(&delegation->lock);
1079 if (delegation->inode != NULL &&
1080 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags) &&
1081 nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
1082 if (nfs_sb_active(server->super)) {
1083 freeme = server->super;
1084 res = igrab(delegation->inode);
1085 }
1086 spin_unlock(&delegation->lock);
1087 if (res != NULL)
1088 return res;
1089 if (freeme) {
1090 rcu_read_unlock();
1091 nfs_sb_deactive(freeme);
1092 rcu_read_lock();
1093 }
1094 return ERR_PTR(-EAGAIN);
1095 }
1096 spin_unlock(&delegation->lock);
1097 }
1098 return ERR_PTR(-ENOENT);
1099}
1100
1101/**
1102 * nfs_delegation_find_inode - retrieve the inode associated with a delegation
1103 * @clp: client state handle
1104 * @fhandle: filehandle from a delegation recall
1105 *
1106 * Returns pointer to inode matching "fhandle," or NULL if a matching inode
1107 * cannot be found.
1108 */
1109struct inode *nfs_delegation_find_inode(struct nfs_client *clp,
1110 const struct nfs_fh *fhandle)
1111{
1112 struct nfs_server *server;
1113 struct inode *res;
1114
1115 rcu_read_lock();
1116 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
1117 res = nfs_delegation_find_inode_server(server, fhandle);
1118 if (res != ERR_PTR(-ENOENT)) {
1119 rcu_read_unlock();
1120 return res;
1121 }
1122 }
1123 rcu_read_unlock();
1124 return ERR_PTR(-ENOENT);
1125}
1126
1127static void nfs_delegation_mark_reclaim_server(struct nfs_server *server)
1128{
1129 struct nfs_delegation *delegation;
1130
1131 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
1132 /*
1133 * If the delegation may have been admin revoked, then we
1134 * cannot reclaim it.
1135 */
1136 if (test_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags))
1137 continue;
1138 set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
1139 }
1140}
1141
1142/**
1143 * nfs_delegation_mark_reclaim - mark all delegations as needing to be reclaimed
1144 * @clp: nfs_client to process
1145 *
1146 */
1147void nfs_delegation_mark_reclaim(struct nfs_client *clp)
1148{
1149 struct nfs_server *server;
1150
1151 rcu_read_lock();
1152 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1153 nfs_delegation_mark_reclaim_server(server);
1154 rcu_read_unlock();
1155}
1156
1157static int nfs_server_reap_unclaimed_delegations(struct nfs_server *server,
1158 void __always_unused *data)
1159{
1160 struct nfs_delegation *delegation;
1161 struct inode *inode;
1162restart:
1163 rcu_read_lock();
1164restart_locked:
1165 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
1166 if (test_bit(NFS_DELEGATION_INODE_FREEING,
1167 &delegation->flags) ||
1168 test_bit(NFS_DELEGATION_RETURNING,
1169 &delegation->flags) ||
1170 test_bit(NFS_DELEGATION_NEED_RECLAIM,
1171 &delegation->flags) == 0)
1172 continue;
1173 inode = nfs_delegation_grab_inode(delegation);
1174 if (inode == NULL)
1175 goto restart_locked;
1176 delegation = nfs_start_delegation_return_locked(NFS_I(inode));
1177 rcu_read_unlock();
1178 if (delegation != NULL) {
1179 if (nfs_detach_delegation(NFS_I(inode), delegation,
1180 server) != NULL)
1181 nfs_free_delegation(delegation);
1182 /* Match nfs_start_delegation_return_locked */
1183 nfs_put_delegation(delegation);
1184 }
1185 iput(inode);
1186 cond_resched();
1187 goto restart;
1188 }
1189 rcu_read_unlock();
1190 return 0;
1191}
1192
1193/**
1194 * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done
1195 * @clp: nfs_client to process
1196 *
1197 */
1198void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
1199{
1200 nfs_client_for_each_server(clp, nfs_server_reap_unclaimed_delegations,
1201 NULL);
1202}
1203
1204static inline bool nfs4_server_rebooted(const struct nfs_client *clp)
1205{
1206 return (clp->cl_state & (BIT(NFS4CLNT_CHECK_LEASE) |
1207 BIT(NFS4CLNT_LEASE_EXPIRED) |
1208 BIT(NFS4CLNT_SESSION_RESET))) != 0;
1209}
1210
1211static void nfs_mark_test_expired_delegation(struct nfs_server *server,
1212 struct nfs_delegation *delegation)
1213{
1214 if (delegation->stateid.type == NFS4_INVALID_STATEID_TYPE)
1215 return;
1216 clear_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
1217 set_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags);
1218 set_bit(NFS4CLNT_DELEGATION_EXPIRED, &server->nfs_client->cl_state);
1219}
1220
1221static void nfs_inode_mark_test_expired_delegation(struct nfs_server *server,
1222 struct inode *inode)
1223{
1224 struct nfs_delegation *delegation;
1225
1226 rcu_read_lock();
1227 delegation = rcu_dereference(NFS_I(inode)->delegation);
1228 if (delegation)
1229 nfs_mark_test_expired_delegation(server, delegation);
1230 rcu_read_unlock();
1231
1232}
1233
1234static void nfs_delegation_mark_test_expired_server(struct nfs_server *server)
1235{
1236 struct nfs_delegation *delegation;
1237
1238 list_for_each_entry_rcu(delegation, &server->delegations, super_list)
1239 nfs_mark_test_expired_delegation(server, delegation);
1240}
1241
1242/**
1243 * nfs_mark_test_expired_all_delegations - mark all delegations for testing
1244 * @clp: nfs_client to process
1245 *
1246 * Iterates through all the delegations associated with this server and
1247 * marks them as needing to be checked for validity.
1248 */
1249void nfs_mark_test_expired_all_delegations(struct nfs_client *clp)
1250{
1251 struct nfs_server *server;
1252
1253 rcu_read_lock();
1254 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1255 nfs_delegation_mark_test_expired_server(server);
1256 rcu_read_unlock();
1257}
1258
1259/**
1260 * nfs_test_expired_all_delegations - test all delegations for a client
1261 * @clp: nfs_client to process
1262 *
1263 * Helper for handling "recallable state revoked" status from server.
1264 */
1265void nfs_test_expired_all_delegations(struct nfs_client *clp)
1266{
1267 nfs_mark_test_expired_all_delegations(clp);
1268 nfs4_schedule_state_manager(clp);
1269}
1270
1271static void
1272nfs_delegation_test_free_expired(struct inode *inode,
1273 nfs4_stateid *stateid,
1274 const struct cred *cred)
1275{
1276 struct nfs_server *server = NFS_SERVER(inode);
1277 const struct nfs4_minor_version_ops *ops = server->nfs_client->cl_mvops;
1278 int status;
1279
1280 if (!cred)
1281 return;
1282 status = ops->test_and_free_expired(server, stateid, cred);
1283 if (status == -NFS4ERR_EXPIRED || status == -NFS4ERR_BAD_STATEID)
1284 nfs_remove_bad_delegation(inode, stateid);
1285}
1286
1287static int nfs_server_reap_expired_delegations(struct nfs_server *server,
1288 void __always_unused *data)
1289{
1290 struct nfs_delegation *delegation;
1291 struct inode *inode;
1292 const struct cred *cred;
1293 nfs4_stateid stateid;
1294 unsigned long gen = ++server->delegation_gen;
1295
1296restart:
1297 rcu_read_lock();
1298restart_locked:
1299 list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
1300 if (test_bit(NFS_DELEGATION_INODE_FREEING,
1301 &delegation->flags) ||
1302 test_bit(NFS_DELEGATION_RETURNING,
1303 &delegation->flags) ||
1304 test_bit(NFS_DELEGATION_TEST_EXPIRED,
1305 &delegation->flags) == 0 ||
1306 delegation->test_gen == gen)
1307 continue;
1308 inode = nfs_delegation_grab_inode(delegation);
1309 if (inode == NULL)
1310 goto restart_locked;
1311 spin_lock(&delegation->lock);
1312 cred = get_cred_rcu(delegation->cred);
1313 nfs4_stateid_copy(&stateid, &delegation->stateid);
1314 spin_unlock(&delegation->lock);
1315 delegation->test_gen = gen;
1316 clear_bit(NFS_DELEGATION_TEST_EXPIRED, &delegation->flags);
1317 rcu_read_unlock();
1318 nfs_delegation_test_free_expired(inode, &stateid, cred);
1319 put_cred(cred);
1320 if (!nfs4_server_rebooted(server->nfs_client)) {
1321 iput(inode);
1322 cond_resched();
1323 goto restart;
1324 }
1325 nfs_inode_mark_test_expired_delegation(server,inode);
1326 iput(inode);
1327 return -EAGAIN;
1328 }
1329 rcu_read_unlock();
1330 return 0;
1331}
1332
1333/**
1334 * nfs_reap_expired_delegations - reap expired delegations
1335 * @clp: nfs_client to process
1336 *
1337 * Iterates through all the delegations associated with this server and
1338 * checks if they have may have been revoked. This function is usually
1339 * expected to be called in cases where the server may have lost its
1340 * lease.
1341 */
1342void nfs_reap_expired_delegations(struct nfs_client *clp)
1343{
1344 nfs_client_for_each_server(clp, nfs_server_reap_expired_delegations,
1345 NULL);
1346}
1347
1348void nfs_inode_find_delegation_state_and_recover(struct inode *inode,
1349 const nfs4_stateid *stateid)
1350{
1351 struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
1352 struct nfs_delegation *delegation;
1353 bool found = false;
1354
1355 rcu_read_lock();
1356 delegation = rcu_dereference(NFS_I(inode)->delegation);
1357 if (delegation &&
1358 nfs4_stateid_match_or_older(&delegation->stateid, stateid) &&
1359 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) {
1360 nfs_mark_test_expired_delegation(NFS_SERVER(inode), delegation);
1361 found = true;
1362 }
1363 rcu_read_unlock();
1364 if (found)
1365 nfs4_schedule_state_manager(clp);
1366}
1367
1368/**
1369 * nfs_delegations_present - check for existence of delegations
1370 * @clp: client state handle
1371 *
1372 * Returns one if there are any nfs_delegation structures attached
1373 * to this nfs_client.
1374 */
1375int nfs_delegations_present(struct nfs_client *clp)
1376{
1377 struct nfs_server *server;
1378 int ret = 0;
1379
1380 rcu_read_lock();
1381 list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
1382 if (!list_empty(&server->delegations)) {
1383 ret = 1;
1384 break;
1385 }
1386 rcu_read_unlock();
1387 return ret;
1388}
1389
1390/**
1391 * nfs4_refresh_delegation_stateid - Update delegation stateid seqid
1392 * @dst: stateid to refresh
1393 * @inode: inode to check
1394 *
1395 * Returns "true" and updates "dst->seqid" * if inode had a delegation
1396 * that matches our delegation stateid. Otherwise "false" is returned.
1397 */
1398bool nfs4_refresh_delegation_stateid(nfs4_stateid *dst, struct inode *inode)
1399{
1400 struct nfs_delegation *delegation;
1401 bool ret = false;
1402 if (!inode)
1403 goto out;
1404
1405 rcu_read_lock();
1406 delegation = rcu_dereference(NFS_I(inode)->delegation);
1407 if (delegation != NULL &&
1408 nfs4_stateid_match_other(dst, &delegation->stateid) &&
1409 nfs4_stateid_is_newer(&delegation->stateid, dst) &&
1410 !test_bit(NFS_DELEGATION_REVOKED, &delegation->flags)) {
1411 dst->seqid = delegation->stateid.seqid;
1412 ret = true;
1413 }
1414 rcu_read_unlock();
1415out:
1416 return ret;
1417}
1418
1419/**
1420 * nfs4_copy_delegation_stateid - Copy inode's state ID information
1421 * @inode: inode to check
1422 * @flags: delegation type requirement
1423 * @dst: stateid data structure to fill in
1424 * @cred: optional argument to retrieve credential
1425 *
1426 * Returns "true" and fills in "dst->data" * if inode had a delegation,
1427 * otherwise "false" is returned.
1428 */
1429bool nfs4_copy_delegation_stateid(struct inode *inode, fmode_t flags,
1430 nfs4_stateid *dst, const struct cred **cred)
1431{
1432 struct nfs_inode *nfsi = NFS_I(inode);
1433 struct nfs_delegation *delegation;
1434 bool ret = false;
1435
1436 flags &= FMODE_READ|FMODE_WRITE;
1437 rcu_read_lock();
1438 delegation = rcu_dereference(nfsi->delegation);
1439 if (!delegation)
1440 goto out;
1441 spin_lock(&delegation->lock);
1442 ret = nfs4_is_valid_delegation(delegation, flags);
1443 if (ret) {
1444 nfs4_stateid_copy(dst, &delegation->stateid);
1445 nfs_mark_delegation_referenced(delegation);
1446 if (cred)
1447 *cred = get_cred(delegation->cred);
1448 }
1449 spin_unlock(&delegation->lock);
1450out:
1451 rcu_read_unlock();
1452 return ret;
1453}
1454
1455/**
1456 * nfs4_delegation_flush_on_close - Check if we must flush file on close
1457 * @inode: inode to check
1458 *
1459 * This function checks the number of outstanding writes to the file
1460 * against the delegation 'space_limit' field to see if
1461 * the spec requires us to flush the file on close.
1462 */
1463bool nfs4_delegation_flush_on_close(const struct inode *inode)
1464{
1465 struct nfs_inode *nfsi = NFS_I(inode);
1466 struct nfs_delegation *delegation;
1467 bool ret = true;
1468
1469 rcu_read_lock();
1470 delegation = rcu_dereference(nfsi->delegation);
1471 if (delegation == NULL || !(delegation->type & FMODE_WRITE))
1472 goto out;
1473 if (atomic_long_read(&nfsi->nrequests) < delegation->pagemod_limit)
1474 ret = false;
1475out:
1476 rcu_read_unlock();
1477 return ret;
1478}
1479
1480module_param_named(delegation_watermark, nfs_delegation_watermark, uint, 0644);