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