aboutsummaryrefslogtreecommitdiffstats
path: root/fs/nfs/delegation.c
blob: 029d688a969f4427e57ccf6f19b0dca9035c3d71 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
/*
 * linux/fs/nfs/delegation.c
 *
 * Copyright (C) 2004 Trond Myklebust
 *
 * NFS file delegation management
 *
 */
#include <linux/completion.h>
#include <linux/kthread.h>
#include <linux/module.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>

#include <linux/nfs4.h>
#include <linux/nfs_fs.h>
#include <linux/nfs_xdr.h>

#include "nfs4_fs.h"
#include "delegation.h"
#include "internal.h"
#include "nfs4trace.h"

static void nfs_free_delegation(struct nfs_delegation *delegation)
{
	if (delegation->cred) {
		put_rpccred(delegation->cred);
		delegation->cred = NULL;
	}
	kfree_rcu(delegation, rcu);
}

/**
 * nfs_mark_delegation_referenced - set delegation's REFERENCED flag
 * @delegation: delegation to process
 *
 */
void nfs_mark_delegation_referenced(struct nfs_delegation *delegation)
{
	set_bit(NFS_DELEGATION_REFERENCED, &delegation->flags);
}

static int
nfs4_do_check_delegation(struct inode *inode, fmode_t flags, bool mark)
{
	struct nfs_delegation *delegation;
	int ret = 0;

	flags &= FMODE_READ|FMODE_WRITE;
	rcu_read_lock();
	delegation = rcu_dereference(NFS_I(inode)->delegation);
	if (delegation != NULL && (delegation->type & flags) == flags &&
	    !test_bit(NFS_DELEGATION_RETURNING, &delegation->flags)) {
		if (mark)
			nfs_mark_delegation_referenced(delegation);
		ret = 1;
	}
	rcu_read_unlock();
	return ret;
}
/**
 * nfs_have_delegation - check if inode has a delegation, mark it
 * NFS_DELEGATION_REFERENCED if there is one.
 * @inode: inode to check
 * @flags: delegation types to check for
 *
 * Returns one if inode has the indicated delegation, otherwise zero.
 */
int nfs4_have_delegation(struct inode *inode, fmode_t flags)
{
	return nfs4_do_check_delegation(inode, flags, true);
}

/*
 * nfs4_check_delegation - check if inode has a delegation, do not mark
 * NFS_DELEGATION_REFERENCED if it has one.
 */
int nfs4_check_delegation(struct inode *inode, fmode_t flags)
{
	return nfs4_do_check_delegation(inode, flags, false);
}

static int nfs_delegation_claim_locks(struct nfs_open_context *ctx, struct nfs4_state *state, const nfs4_stateid *stateid)
{
	struct inode *inode = state->inode;
	struct file_lock *fl;
	struct file_lock_context *flctx = inode->i_flctx;
	struct list_head *list;
	int status = 0;

	if (flctx == NULL)
		goto out;

	list = &flctx->flc_posix;
	spin_lock(&flctx->flc_lock);
restart:
	list_for_each_entry(fl, list, fl_list) {
		if (nfs_file_open_context(fl->fl_file) != ctx)
			continue;
		spin_unlock(&flctx->flc_lock);
		status = nfs4_lock_delegation_recall(fl, state, stateid);
		if (status < 0)
			goto out;
		spin_lock(&flctx->flc_lock);
	}
	if (list == &flctx->flc_posix) {
		list = &flctx->flc_flock;
		goto restart;
	}
	spin_unlock(&flctx->flc_lock);
out:
	return status;
}

static int nfs_delegation_claim_opens(struct inode *inode, const nfs4_stateid *stateid)
{
	struct nfs_inode *nfsi = NFS_I(inode);
	struct nfs_open_context *ctx;
	struct nfs4_state_owner *sp;
	struct nfs4_state *state;
	unsigned int seq;
	int err;

again:
	spin_lock(&inode->i_lock);
	list_for_each_entry(ctx, &nfsi->open_files, list) {
		state = ctx->state;
		if (state == NULL)
			continue;
		if (!test_bit(NFS_DELEGATED_STATE, &state->flags))
			continue;
		if (!nfs4_valid_open_stateid(state))
			continue;
		if (!nfs4_stateid_match(&state->stateid, stateid))
			continue;
		get_nfs_open_context(ctx);
		spin_unlock(&inode->i_lock);
		sp = state->owner;
		/* Block nfs4_proc_unlck */
		mutex_lock(&sp->so_delegreturn_mutex);
		seq = raw_seqcount_begin(&sp->so_reclaim_seqcount);
		err = nfs4_open_delegation_recall(ctx, state, stateid);
		if (!err)
			err = nfs_delegation_claim_locks(ctx, state, stateid);
		if (!err && read_seqcount_retry(&sp->so_reclaim_seqcount, seq))
			err = -EAGAIN;
		mutex_unlock(&sp->so_delegreturn_mutex);
		put_nfs_open_context(ctx);
		if (err != 0)
			return err;
		goto again;
	}
	spin_unlock(&inode->i_lock);
	return 0;
}

/**
 * nfs_inode_reclaim_delegation - process a delegation reclaim request
 * @inode: inode to process
 * @cred: credential to use for request
 * @res: new delegation state from server
 *
 */
void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred,
				  struct nfs_openres *res)
{
	struct nfs_delegation *delegation;
	struct rpc_cred *oldcred = NULL;

	rcu_read_lock();
	delegation = rcu_dereference(NFS_I(inode)->delegation);
	if (delegation != NULL) {
		spin_lock(&delegation->lock);
		if (delegation->inode != NULL) {
			nfs4_stateid_copy(&delegation->stateid, &res->delegation);
			delegation->type = res->delegation_type;
			delegation->maxsize = res->maxsize;
			oldcred = delegation->cred;
			delegation->cred = get_rpccred(cred);
			clear_bit(NFS_DELEGATION_NEED_RECLAIM,
				  &delegation->flags);
			spin_unlock(&delegation->lock);
			rcu_read_unlock();
			put_rpccred(oldcred);
			trace_nfs4_reclaim_delegation(inode, res->delegation_type);
		} else {
			/* We appear to have raced with a delegation return. */
			spin_unlock(&delegation->lock);
			rcu_read_unlock();
			nfs_inode_set_delegation(inode, cred, res);
		}
	} else {
		rcu_read_unlock();
	}
}

static int nfs_do_return_delegation(struct inode *inode, struct nfs_delegation *delegation, int issync)
{
	int res = 0;

	if (!test_bit(NFS_DELEGATION_REVOKED, &delegation->flags))
		res = nfs4_proc_delegreturn(inode,
				delegation->cred,
				&delegation->stateid,
				issync);
	nfs_free_delegation(delegation);
	return res;
}

static struct inode *nfs_delegation_grab_inode(struct nfs_delegation *delegation)
{
	struct inode *inode = NULL;

	spin_lock(&delegation->lock);
	if (delegation->inode != NULL)
		inode = igrab(delegation->inode);
	spin_unlock(&delegation->lock);
	return inode;
}

static struct nfs_delegation *
nfs_start_delegation_return_locked(struct nfs_inode *nfsi)
{
	struct nfs_delegation *ret = NULL;
	struct nfs_delegation *delegation = rcu_dereference(nfsi->delegation);

	if (delegation == NULL)
		goto out;
	spin_lock(&delegation->lock);
	if (!test_and_set_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
		ret = delegation;
	spin_unlock(&delegation->lock);
out:
	return ret;
}

static struct nfs_delegation *
nfs_start_delegation_return(struct nfs_inode *nfsi)
{
	struct nfs_delegation *delegation;

	rcu_read_lock();
	delegation = nfs_start_delegation_return_locked(nfsi);
	rcu_read_unlock();
	return delegation;
}

static void
nfs_abort_delegation_return(struct nfs_delegation *delegation,
		struct nfs_client *clp)
{

	spin_lock(&delegation->lock);
	clear_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
	set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
	spin_unlock(&delegation->lock);
	set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
}

static struct nfs_delegation *
nfs_detach_delegation_locked(struct nfs_inode *nfsi,
		struct nfs_delegation *delegation,
		struct nfs_client *clp)
{
	struct nfs_delegation *deleg_cur =
		rcu_dereference_protected(nfsi->delegation,
				lockdep_is_held(&clp->cl_lock));

	if (deleg_cur == NULL || delegation != deleg_cur)
		return NULL;

	spin_lock(&delegation->lock);
	set_bit(NFS_DELEGATION_RETURNING, &delegation->flags);
	list_del_rcu(&delegation->super_list);
	delegation->inode = NULL;
	rcu_assign_pointer(nfsi->delegation, NULL);
	spin_unlock(&delegation->lock);
	return delegation;
}

static struct nfs_delegation *nfs_detach_delegation(struct nfs_inode *nfsi,
		struct nfs_delegation *delegation,
		struct nfs_server *server)
{
	struct nfs_client *clp = server->nfs_client;

	spin_lock(&clp->cl_lock);
	delegation = nfs_detach_delegation_locked(nfsi, delegation, clp);
	spin_unlock(&clp->cl_lock);
	return delegation;
}

static struct nfs_delegation *
nfs_inode_detach_delegation(struct inode *inode)
{
	struct nfs_inode *nfsi = NFS_I(inode);
	struct nfs_server *server = NFS_SERVER(inode);
	struct nfs_delegation *delegation;

	delegation = nfs_start_delegation_return(nfsi);
	if (delegation == NULL)
		return NULL;
	return nfs_detach_delegation(nfsi, delegation, server);
}

static void
nfs_update_inplace_delegation(struct nfs_delegation *delegation,
		const struct nfs_delegation *update)
{
	if (nfs4_stateid_is_newer(&update->stateid, &delegation->stateid)) {
		delegation->stateid.seqid = update->stateid.seqid;
		smp_wmb();
		delegation->type = update->type;
	}
}

/**
 * nfs_inode_set_delegation - set up a delegation on an inode
 * @inode: inode to which delegation applies
 * @cred: cred to use for subsequent delegation processing
 * @res: new delegation state from server
 *
 * Returns zero on success, or a negative errno value.
 */
int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct nfs_openres *res)
{
	struct nfs_server *server = NFS_SERVER(inode);
	struct nfs_client *clp = server->nfs_client;
	struct nfs_inode *nfsi = NFS_I(inode);
	struct nfs_delegation *delegation, *old_delegation;
	struct nfs_delegation *freeme = NULL;
	int status = 0;

	delegation = kmalloc(sizeof(*delegation), GFP_NOFS);
	if (delegation == NULL)
		return -ENOMEM;
	nfs4_stateid_copy(&delegation->stateid, &res->delegation);
	delegation->type = res->delegation_type;
	delegation->maxsize = res->maxsize;
	delegation->change_attr = inode->i_version;
	delegation->cred = get_rpccred(cred);
	delegation->inode = inode;
	delegation->flags = 1<<NFS_DELEGATION_REFERENCED;
	spin_lock_init(&delegation->lock);

	spin_lock(&clp->cl_lock);
	old_delegation = rcu_dereference_protected(nfsi->delegation,
					lockdep_is_held(&clp->cl_lock));
	if (old_delegation != NULL) {
		/* Is this an update of the existing delegation? */
		if (nfs4_stateid_match_other(&old_delegation->stateid,
					&delegation->stateid)) {
			nfs_update_inplace_delegation(old_delegation,
					delegation);
			goto out;
		}
		/*
		 * Deal with broken servers that hand out two
		 * delegations for the same file.
		 * Allow for upgrades to a WRITE delegation, but
		 * nothing else.
		 */
		dfprintk(FILE, "%s: server %s handed out "
				"a duplicate delegation!\n",
				__func__, clp->cl_hostname);
		if (delegation->type == old_delegation->type ||
		    !(delegation->type & FMODE_WRITE)) {
			freeme = delegation;
			delegation = NULL;
			goto out;
		}
		if (test_and_set_bit(NFS_DELEGATION_RETURNING,
					&old_delegation->flags))
			goto out;
		freeme = nfs_detach_delegation_locked(nfsi,
				old_delegation, clp);
		if (freeme == NULL)
			goto out;
	}
	list_add_tail_rcu(&delegation->super_list, &server->delegations);
	rcu_assign_pointer(nfsi->delegation, delegation);
	delegation = NULL;

	/* Ensure we revalidate the attributes and page cache! */
	spin_lock(&inode->i_lock);
	nfsi->cache_validity |= NFS_INO_REVAL_FORCED;
	spin_unlock(&inode->i_lock);
	trace_nfs4_set_delegation(inode, res->delegation_type);

out:
	spin_unlock(&clp->cl_lock);
	if (delegation != NULL)
		nfs_free_delegation(delegation);
	if (freeme != NULL)
		nfs_do_return_delegation(inode, freeme, 0);
	return status;
}

/*
 * Basic procedure for returning a delegation to the server
 */
static int nfs_end_delegation_return(struct inode *inode, struct nfs_delegation *delegation, int issync)
{
	struct nfs_client *clp = NFS_SERVER(inode)->nfs_client;
	struct nfs_inode *nfsi = NFS_I(inode);
	int err = 0;

	if (delegation == NULL)
		return 0;
	do {
		if (test_bit(NFS_DELEGATION_REVOKED, &delegation->flags))
			break;
		err = nfs_delegation_claim_opens(inode, &delegation->stateid);
		if (!issync || err != -EAGAIN)
			break;
		/*
		 * Guard against state recovery
		 */
		err = nfs4_wait_clnt_recover(clp);
	} while (err == 0);

	if (err) {
		nfs_abort_delegation_return(delegation, clp);
		goto out;
	}
	if (!nfs_detach_delegation(nfsi, delegation, NFS_SERVER(inode)))
		goto out;

	err = nfs_do_return_delegation(inode, delegation, issync);
out:
	return err;
}

static bool nfs_delegation_need_return(struct nfs_delegation *delegation)
{
	bool ret = false;

	if (test_bit(NFS_DELEGATION_RETURNING, &delegation->flags))
		goto out;
	if (test_and_clear_bit(NFS_DELEGATION_RETURN, &delegation->flags))
		ret = true;
	if (test_and_clear_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags) && !ret) {
		struct inode *inode;

		spin_lock(&delegation->lock);
		inode = delegation->inode;
		if (inode && list_empty(&NFS_I(inode)->open_files))
			ret = true;
		spin_unlock(&delegation->lock);
	}
out:
	return ret;
}

/**
 * nfs_client_return_marked_delegations - return previously marked delegations
 * @clp: nfs_client to process
 *
 * Note that this function is designed to be called by the state
 * manager thread. For this reason, it cannot flush the dirty data,
 * since that could deadlock in case of a state recovery error.
 *
 * Returns zero on success, or a negative errno value.
 */
int nfs_client_return_marked_delegations(struct nfs_client *clp)
{
	struct nfs_delegation *delegation;
	struct nfs_server *server;
	struct inode *inode;
	int err = 0;

restart:
	rcu_read_lock();
	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
		list_for_each_entry_rcu(delegation, &server->delegations,
								super_list) {
			if (!nfs_delegation_need_return(delegation))
				continue;
			if (!nfs_sb_active(server->super))
				continue;
			inode = nfs_delegation_grab_inode(delegation);
			if (inode == NULL) {
				rcu_read_unlock();
				nfs_sb_deactive(server->super);
				goto restart;
			}
			delegation = nfs_start_delegation_return_locked(NFS_I(inode));
			rcu_read_unlock();

			err = nfs_end_delegation_return(inode, delegation, 0);
			iput(inode);
			nfs_sb_deactive(server->super);
			if (!err)
				goto restart;
			set_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state);
			return err;
		}
	}
	rcu_read_unlock();
	return 0;
}

/**
 * nfs_inode_return_delegation_noreclaim - return delegation, don't reclaim opens
 * @inode: inode to process
 *
 * Does not protect against delegation reclaims, therefore really only safe
 * to be called from nfs4_clear_inode().
 */
void nfs_inode_return_delegation_noreclaim(struct inode *inode)
{
	struct nfs_delegation *delegation;

	delegation = nfs_inode_detach_delegation(inode);
	if (delegation != NULL)
		nfs_do_return_delegation(inode, delegation, 1);
}

/**
 * nfs_inode_return_delegation - synchronously return a delegation
 * @inode: inode to process
 *
 * This routine will always flush any dirty data to disk on the
 * assumption that if we need to return the delegation, then
 * we should stop caching.
 *
 * Returns zero on success, or a negative errno value.
 */
int nfs4_inode_return_delegation(struct inode *inode)
{
	struct nfs_inode *nfsi = NFS_I(inode);
	struct nfs_delegation *delegation;
	int err = 0;

	nfs_wb_all(inode);
	delegation = nfs_start_delegation_return(nfsi);
	if (delegation != NULL)
		err = nfs_end_delegation_return(inode, delegation, 1);
	return err;
}

static void nfs_mark_return_if_closed_delegation(struct nfs_server *server,
		struct nfs_delegation *delegation)
{
	set_bit(NFS_DELEGATION_RETURN_IF_CLOSED, &delegation->flags);
	set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
}

static void nfs_mark_return_delegation(struct nfs_server *server,
		struct nfs_delegation *delegation)
{
	set_bit(NFS_DELEGATION_RETURN, &delegation->flags);
	set_bit(NFS4CLNT_DELEGRETURN, &server->nfs_client->cl_state);
}

static bool nfs_server_mark_return_all_delegations(struct nfs_server *server)
{
	struct nfs_delegation *delegation;
	bool ret = false;

	list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
		nfs_mark_return_delegation(server, delegation);
		ret = true;
	}
	return ret;
}

static void nfs_client_mark_return_all_delegations(struct nfs_client *clp)
{
	struct nfs_server *server;

	rcu_read_lock();
	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
		nfs_server_mark_return_all_delegations(server);
	rcu_read_unlock();
}

static void nfs_delegation_run_state_manager(struct nfs_client *clp)
{
	if (test_bit(NFS4CLNT_DELEGRETURN, &clp->cl_state))
		nfs4_schedule_state_manager(clp);
}

/**
 * nfs_expire_all_delegations
 * @clp: client to process
 *
 */
void nfs_expire_all_delegations(struct nfs_client *clp)
{
	nfs_client_mark_return_all_delegations(clp);
	nfs_delegation_run_state_manager(clp);
}

/**
 * nfs_super_return_all_delegations - return delegations for one superblock
 * @sb: sb to process
 *
 */
void nfs_server_return_all_delegations(struct nfs_server *server)
{
	struct nfs_client *clp = server->nfs_client;
	bool need_wait;

	if (clp == NULL)
		return;

	rcu_read_lock();
	need_wait = nfs_server_mark_return_all_delegations(server);
	rcu_read_unlock();

	if (need_wait) {
		nfs4_schedule_state_manager(clp);
		nfs4_wait_clnt_recover(clp);
	}
}

static void nfs_mark_return_unused_delegation_types(struct nfs_server *server,
						 fmode_t flags)
{
	struct nfs_delegation *delegation;

	list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
		if ((delegation->type == (FMODE_READ|FMODE_WRITE)) && !(flags & FMODE_WRITE))
			continue;
		if (delegation->type & flags)
			nfs_mark_return_if_closed_delegation(server, delegation);
	}
}

static void nfs_client_mark_return_unused_delegation_types(struct nfs_client *clp,
							fmode_t flags)
{
	struct nfs_server *server;

	rcu_read_lock();
	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
		nfs_mark_return_unused_delegation_types(server, flags);
	rcu_read_unlock();
}

static void nfs_revoke_delegation(struct inode *inode)
{
	struct nfs_delegation *delegation;
	rcu_read_lock();
	delegation = rcu_dereference(NFS_I(inode)->delegation);
	if (delegation != NULL) {
		set_bit(NFS_DELEGATION_REVOKED, &delegation->flags);
		nfs_mark_return_delegation(NFS_SERVER(inode), delegation);
	}
	rcu_read_unlock();
}

void nfs_remove_bad_delegation(struct inode *inode)
{
	struct nfs_delegation *delegation;

	nfs_revoke_delegation(inode);
	delegation = nfs_inode_detach_delegation(inode);
	if (delegation) {
		nfs_inode_find_state_and_recover(inode, &delegation->stateid);
		nfs_free_delegation(delegation);
	}
}
EXPORT_SYMBOL_GPL(nfs_remove_bad_delegation);

/**
 * nfs_expire_unused_delegation_types
 * @clp: client to process
 * @flags: delegation types to expire
 *
 */
void nfs_expire_unused_delegation_types(struct nfs_client *clp, fmode_t flags)
{
	nfs_client_mark_return_unused_delegation_types(clp, flags);
	nfs_delegation_run_state_manager(clp);
}

static void nfs_mark_return_unreferenced_delegations(struct nfs_server *server)
{
	struct nfs_delegation *delegation;

	list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
		if (test_and_clear_bit(NFS_DELEGATION_REFERENCED, &delegation->flags))
			continue;
		nfs_mark_return_if_closed_delegation(server, delegation);
	}
}

/**
 * nfs_expire_unreferenced_delegations - Eliminate unused delegations
 * @clp: nfs_client to process
 *
 */
void nfs_expire_unreferenced_delegations(struct nfs_client *clp)
{
	struct nfs_server *server;

	rcu_read_lock();
	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
		nfs_mark_return_unreferenced_delegations(server);
	rcu_read_unlock();

	nfs_delegation_run_state_manager(clp);
}

/**
 * nfs_async_inode_return_delegation - asynchronously return a delegation
 * @inode: inode to process
 * @stateid: state ID information
 *
 * Returns zero on success, or a negative errno value.
 */
int nfs_async_inode_return_delegation(struct inode *inode,
				      const nfs4_stateid *stateid)
{
	struct nfs_server *server = NFS_SERVER(inode);
	struct nfs_client *clp = server->nfs_client;
	struct nfs_delegation *delegation;

	filemap_flush(inode->i_mapping);

	rcu_read_lock();
	delegation = rcu_dereference(NFS_I(inode)->delegation);
	if (delegation == NULL)
		goto out_enoent;

	if (!clp->cl_mvops->match_stateid(&delegation->stateid, stateid))
		goto out_enoent;
	nfs_mark_return_delegation(server, delegation);
	rcu_read_unlock();

	nfs_delegation_run_state_manager(clp);
	return 0;
out_enoent:
	rcu_read_unlock();
	return -ENOENT;
}

static struct inode *
nfs_delegation_find_inode_server(struct nfs_server *server,
				 const struct nfs_fh *fhandle)
{
	struct nfs_delegation *delegation;
	struct inode *res = NULL;

	list_for_each_entry_rcu(delegation, &server->delegations, super_list) {
		spin_lock(&delegation->lock);
		if (delegation->inode != NULL &&
		    nfs_compare_fh(fhandle, &NFS_I(delegation->inode)->fh) == 0) {
			res = igrab(delegation->inode);
		}
		spin_unlock(&delegation->lock);
		if (res != NULL)
			break;
	}
	return res;
}

/**
 * nfs_delegation_find_inode - retrieve the inode associated with a delegation
 * @clp: client state handle
 * @fhandle: filehandle from a delegation recall
 *
 * Returns pointer to inode matching "fhandle," or NULL if a matching inode
 * cannot be found.
 */
struct inode *nfs_delegation_find_inode(struct nfs_client *clp,
					const struct nfs_fh *fhandle)
{
	struct nfs_server *server;
	struct inode *res = NULL;

	rcu_read_lock();
	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
		res = nfs_delegation_find_inode_server(server, fhandle);
		if (res != NULL)
			break;
	}
	rcu_read_unlock();
	return res;
}

static void nfs_delegation_mark_reclaim_server(struct nfs_server *server)
{
	struct nfs_delegation *delegation;

	list_for_each_entry_rcu(delegation, &server->delegations, super_list)
		set_bit(NFS_DELEGATION_NEED_RECLAIM, &delegation->flags);
}

/**
 * nfs_delegation_mark_reclaim - mark all delegations as needing to be reclaimed
 * @clp: nfs_client to process
 *
 */
void nfs_delegation_mark_reclaim(struct nfs_client *clp)
{
	struct nfs_server *server;

	rcu_read_lock();
	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
		nfs_delegation_mark_reclaim_server(server);
	rcu_read_unlock();
}

/**
 * nfs_delegation_reap_unclaimed - reap unclaimed delegations after reboot recovery is done
 * @clp: nfs_client to process
 *
 */
void nfs_delegation_reap_unclaimed(struct nfs_client *clp)
{
	struct nfs_delegation *delegation;
	struct nfs_server *server;
	struct inode *inode;

restart:
	rcu_read_lock();
	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link) {
		list_for_each_entry_rcu(delegation, &server->delegations,
								super_list) {
			if (test_bit(NFS_DELEGATION_RETURNING,
						&delegation->flags))
				continue;
			if (test_bit(NFS_DELEGATION_NEED_RECLAIM,
						&delegation->flags) == 0)
				continue;
			if (!nfs_sb_active(server->super))
				continue;
			inode = nfs_delegation_grab_inode(delegation);
			if (inode == NULL) {
				rcu_read_unlock();
				nfs_sb_deactive(server->super);
				goto restart;
			}
			delegation = nfs_start_delegation_return_locked(NFS_I(inode));
			rcu_read_unlock();
			if (delegation != NULL) {
				delegation = nfs_detach_delegation(NFS_I(inode),
					delegation, server);
				if (delegation != NULL)
					nfs_free_delegation(delegation);
			}
			iput(inode);
			nfs_sb_deactive(server->super);
			goto restart;
		}
	}
	rcu_read_unlock();
}

/**
 * nfs_delegations_present - check for existence of delegations
 * @clp: client state handle
 *
 * Returns one if there are any nfs_delegation structures attached
 * to this nfs_client.
 */
int nfs_delegations_present(struct nfs_client *clp)
{
	struct nfs_server *server;
	int ret = 0;

	rcu_read_lock();
	list_for_each_entry_rcu(server, &clp->cl_superblocks, client_link)
		if (!list_empty(&server->delegations)) {
			ret = 1;
			break;
		}
	rcu_read_unlock();
	return ret;
}

/**
 * nfs4_copy_delegation_stateid - Copy inode's state ID information
 * @dst: stateid data structure to fill in
 * @inode: inode to check
 * @flags: delegation type requirement
 *
 * Returns "true" and fills in "dst->data" * if inode had a delegation,
 * otherwise "false" is returned.
 */
bool nfs4_copy_delegation_stateid(nfs4_stateid *dst, struct inode *inode,
		fmode_t flags)
{
	struct nfs_inode *nfsi = NFS_I(inode);
	struct nfs_delegation *delegation;
	bool ret;

	flags &= FMODE_READ|FMODE_WRITE;
	rcu_read_lock();
	delegation = rcu_dereference(nfsi->delegation);
	ret = (delegation != NULL && (delegation->type & flags) == flags);
	if (ret) {
		nfs4_stateid_copy(dst, &delegation->stateid);
		nfs_mark_delegation_referenced(delegation);
	}
	rcu_read_unlock();
	return ret;
}

Privacy Policy