summaryrefslogtreecommitdiff
path: root/fs/nfs/pnfs_nfs.c
blob: afd23910f3bffc52b7d4505e4bb7b6eaa0b632fa (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
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
// SPDX-License-Identifier: GPL-2.0-only
/*
 * Common NFS I/O  operations for the pnfs file based
 * layout drivers.
 *
 * Copyright (c) 2014, Primary Data, Inc. All rights reserved.
 *
 * Tom Haynes <loghyr@primarydata.com>
 */

#include <linux/nfs_fs.h>
#include <linux/nfs_page.h>
#include <linux/sunrpc/addr.h>
#include <linux/module.h>

#include "nfs4session.h"
#include "internal.h"
#include "pnfs.h"

#define NFSDBG_FACILITY		NFSDBG_PNFS

void pnfs_generic_rw_release(void *data)
{
	struct nfs_pgio_header *hdr = data;

	nfs_put_client(hdr->ds_clp);
	hdr->mds_ops->rpc_release(data);
}
EXPORT_SYMBOL_GPL(pnfs_generic_rw_release);

/* Fake up some data that will cause nfs_commit_release to retry the writes. */
void pnfs_generic_prepare_to_resend_writes(struct nfs_commit_data *data)
{
	struct nfs_writeverf *verf = data->res.verf;

	data->task.tk_status = 0;
	memset(&verf->verifier, 0, sizeof(verf->verifier));
	verf->committed = NFS_UNSTABLE;
}
EXPORT_SYMBOL_GPL(pnfs_generic_prepare_to_resend_writes);

void pnfs_generic_write_commit_done(struct rpc_task *task, void *data)
{
	struct nfs_commit_data *wdata = data;

	/* Note this may cause RPC to be resent */
	wdata->mds_ops->rpc_call_done(task, data);
}
EXPORT_SYMBOL_GPL(pnfs_generic_write_commit_done);

void pnfs_generic_commit_release(void *calldata)
{
	struct nfs_commit_data *data = calldata;

	data->completion_ops->completion(data);
	pnfs_put_lseg(data->lseg);
	nfs_put_client(data->ds_clp);
	nfs_commitdata_release(data);
}
EXPORT_SYMBOL_GPL(pnfs_generic_commit_release);

static struct pnfs_layout_segment *
pnfs_free_bucket_lseg(struct pnfs_commit_bucket *bucket)
{
	if (list_empty(&bucket->committing) && list_empty(&bucket->written)) {
		struct pnfs_layout_segment *freeme = bucket->lseg;
		bucket->lseg = NULL;
		return freeme;
	}
	return NULL;
}

/* The generic layer is about to remove the req from the commit list.
 * If this will make the bucket empty, it will need to put the lseg reference.
 * Note this must be called holding nfsi->commit_mutex
 */
void
pnfs_generic_clear_request_commit(struct nfs_page *req,
				  struct nfs_commit_info *cinfo)
{
	struct pnfs_commit_bucket *bucket = NULL;

	if (!test_and_clear_bit(PG_COMMIT_TO_DS, &req->wb_flags))
		goto out;
	cinfo->ds->nwritten--;
	if (list_is_singular(&req->wb_list))
		bucket = list_first_entry(&req->wb_list,
					  struct pnfs_commit_bucket, written);
out:
	nfs_request_remove_commit_list(req, cinfo);
	if (bucket)
		pnfs_put_lseg(pnfs_free_bucket_lseg(bucket));
}
EXPORT_SYMBOL_GPL(pnfs_generic_clear_request_commit);

struct pnfs_commit_array *
pnfs_alloc_commit_array(size_t n, gfp_t gfp_flags)
{
	struct pnfs_commit_array *p;
	struct pnfs_commit_bucket *b;

	p = kmalloc(struct_size(p, buckets, n), gfp_flags);
	if (!p)
		return NULL;
	p->nbuckets = n;
	INIT_LIST_HEAD(&p->cinfo_list);
	INIT_LIST_HEAD(&p->lseg_list);
	p->lseg = NULL;
	for (b = &p->buckets[0]; n != 0; b++, n--) {
		INIT_LIST_HEAD(&b->written);
		INIT_LIST_HEAD(&b->committing);
		b->lseg = NULL;
		b->direct_verf.committed = NFS_INVALID_STABLE_HOW;
	}
	return p;
}
EXPORT_SYMBOL_GPL(pnfs_alloc_commit_array);

void
pnfs_free_commit_array(struct pnfs_commit_array *p)
{
	kfree_rcu(p, rcu);
}
EXPORT_SYMBOL_GPL(pnfs_free_commit_array);

static struct pnfs_commit_array *
pnfs_find_commit_array_by_lseg(struct pnfs_ds_commit_info *fl_cinfo,
		struct pnfs_layout_segment *lseg)
{
	struct pnfs_commit_array *array;

	list_for_each_entry_rcu(array, &fl_cinfo->commits, cinfo_list) {
		if (array->lseg == lseg)
			return array;
	}
	return NULL;
}

struct pnfs_commit_array *
pnfs_add_commit_array(struct pnfs_ds_commit_info *fl_cinfo,
		struct pnfs_commit_array *new,
		struct pnfs_layout_segment *lseg)
{
	struct pnfs_commit_array *array;

	array = pnfs_find_commit_array_by_lseg(fl_cinfo, lseg);
	if (array)
		return array;
	new->lseg = lseg;
	refcount_set(&new->refcount, 1);
	list_add_rcu(&new->cinfo_list, &fl_cinfo->commits);
	list_add(&new->lseg_list, &lseg->pls_commits);
	return new;
}
EXPORT_SYMBOL_GPL(pnfs_add_commit_array);

static struct pnfs_commit_array *
pnfs_lookup_commit_array(struct pnfs_ds_commit_info *fl_cinfo,
		struct pnfs_layout_segment *lseg)
{
	struct pnfs_commit_array *array;

	rcu_read_lock();
	array = pnfs_find_commit_array_by_lseg(fl_cinfo, lseg);
	if (!array) {
		rcu_read_unlock();
		fl_cinfo->ops->setup_ds_info(fl_cinfo, lseg);
		rcu_read_lock();
		array = pnfs_find_commit_array_by_lseg(fl_cinfo, lseg);
	}
	rcu_read_unlock();
	return array;
}

static void
pnfs_release_commit_array_locked(struct pnfs_commit_array *array)
{
	list_del_rcu(&array->cinfo_list);
	list_del(&array->lseg_list);
	pnfs_free_commit_array(array);
}

static void
pnfs_put_commit_array_locked(struct pnfs_commit_array *array)
{
	if (refcount_dec_and_test(&array->refcount))
		pnfs_release_commit_array_locked(array);
}

static void
pnfs_put_commit_array(struct pnfs_commit_array *array, struct inode *inode)
{
	if (refcount_dec_and_lock(&array->refcount, &inode->i_lock)) {
		pnfs_release_commit_array_locked(array);
		spin_unlock(&inode->i_lock);
	}
}

static struct pnfs_commit_array *
pnfs_get_commit_array(struct pnfs_commit_array *array)
{
	if (refcount_inc_not_zero(&array->refcount))
		return array;
	return NULL;
}

static void
pnfs_remove_and_free_commit_array(struct pnfs_commit_array *array)
{
	array->lseg = NULL;
	list_del_init(&array->lseg_list);
	pnfs_put_commit_array_locked(array);
}

void
pnfs_generic_ds_cinfo_release_lseg(struct pnfs_ds_commit_info *fl_cinfo,
		struct pnfs_layout_segment *lseg)
{
	struct pnfs_commit_array *array, *tmp;

	list_for_each_entry_safe(array, tmp, &lseg->pls_commits, lseg_list)
		pnfs_remove_and_free_commit_array(array);
}
EXPORT_SYMBOL_GPL(pnfs_generic_ds_cinfo_release_lseg);

void
pnfs_generic_ds_cinfo_destroy(struct pnfs_ds_commit_info *fl_cinfo)
{
	struct pnfs_commit_array *array, *tmp;

	list_for_each_entry_safe(array, tmp, &fl_cinfo->commits, cinfo_list)
		pnfs_remove_and_free_commit_array(array);
}
EXPORT_SYMBOL_GPL(pnfs_generic_ds_cinfo_destroy);

/*
 * Locks the nfs_page requests for commit and moves them to
 * @bucket->committing.
 */
static int
pnfs_bucket_scan_ds_commit_list(struct pnfs_commit_bucket *bucket,
				struct nfs_commit_info *cinfo,
				int max)
{
	struct list_head *src = &bucket->written;
	struct list_head *dst = &bucket->committing;
	int ret;

	lockdep_assert_held(&NFS_I(cinfo->inode)->commit_mutex);
	ret = nfs_scan_commit_list(src, dst, cinfo, max);
	if (ret) {
		cinfo->ds->nwritten -= ret;
		cinfo->ds->ncommitting += ret;
	}
	return ret;
}

static int pnfs_bucket_scan_array(struct nfs_commit_info *cinfo,
				  struct pnfs_commit_bucket *buckets,
				  unsigned int nbuckets,
				  int max)
{
	unsigned int i;
	int rv = 0, cnt;

	for (i = 0; i < nbuckets && max != 0; i++) {
		cnt = pnfs_bucket_scan_ds_commit_list(&buckets[i], cinfo, max);
		rv += cnt;
		max -= cnt;
	}
	return rv;
}

/* Move reqs from written to committing lists, returning count
 * of number moved.
 */
int pnfs_generic_scan_commit_lists(struct nfs_commit_info *cinfo, int max)
{
	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
	struct pnfs_commit_array *array;
	int rv = 0, cnt;

	rcu_read_lock();
	list_for_each_entry_rcu(array, &fl_cinfo->commits, cinfo_list) {
		if (!array->lseg || !pnfs_get_commit_array(array))
			continue;
		rcu_read_unlock();
		cnt = pnfs_bucket_scan_array(cinfo, array->buckets,
				array->nbuckets, max);
		rcu_read_lock();
		pnfs_put_commit_array(array, cinfo->inode);
		rv += cnt;
		max -= cnt;
		if (!max)
			break;
	}
	rcu_read_unlock();
	return rv;
}
EXPORT_SYMBOL_GPL(pnfs_generic_scan_commit_lists);

static unsigned int
pnfs_bucket_recover_commit_reqs(struct list_head *dst,
			        struct pnfs_commit_bucket *buckets,
				unsigned int nbuckets,
				struct nfs_commit_info *cinfo)
{
	struct pnfs_commit_bucket *b;
	struct pnfs_layout_segment *freeme;
	unsigned int nwritten, ret = 0;
	unsigned int i;

restart:
	for (i = 0, b = buckets; i < nbuckets; i++, b++) {
		nwritten = nfs_scan_commit_list(&b->written, dst, cinfo, 0);
		if (!nwritten)
			continue;
		ret += nwritten;
		freeme = pnfs_free_bucket_lseg(b);
		if (freeme) {
			pnfs_put_lseg(freeme);
			goto restart;
		}
	}
	return ret;
}

/* Pull everything off the committing lists and dump into @dst.  */
void pnfs_generic_recover_commit_reqs(struct list_head *dst,
				      struct nfs_commit_info *cinfo)
{
	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
	struct pnfs_commit_array *array;
	unsigned int nwritten;

	lockdep_assert_held(&NFS_I(cinfo->inode)->commit_mutex);
	rcu_read_lock();
	list_for_each_entry_rcu(array, &fl_cinfo->commits, cinfo_list) {
		if (!array->lseg || !pnfs_get_commit_array(array))
			continue;
		rcu_read_unlock();
		nwritten = pnfs_bucket_recover_commit_reqs(dst,
							   array->buckets,
							   array->nbuckets,
							   cinfo);
		rcu_read_lock();
		pnfs_put_commit_array(array, cinfo->inode);
		fl_cinfo->nwritten -= nwritten;
	}
	rcu_read_unlock();
}
EXPORT_SYMBOL_GPL(pnfs_generic_recover_commit_reqs);

static struct nfs_page *
pnfs_bucket_search_commit_reqs(struct pnfs_commit_bucket *buckets,
			       unsigned int nbuckets, struct folio *folio)
{
	struct nfs_page *req;
	struct pnfs_commit_bucket *b;
	unsigned int i;

	/* Linearly search the commit lists for each bucket until a matching
	 * request is found */
	for (i = 0, b = buckets; i < nbuckets; i++, b++) {
		list_for_each_entry(req, &b->written, wb_list) {
			if (nfs_page_to_folio(req) == folio)
				return req->wb_head;
		}
		list_for_each_entry(req, &b->committing, wb_list) {
			if (nfs_page_to_folio(req) == folio)
				return req->wb_head;
		}
	}
	return NULL;
}

/* pnfs_generic_search_commit_reqs - Search lists in @cinfo for the head request
 *				   for @folio
 * @cinfo - commit info for current inode
 * @folio - page to search for matching head request
 *
 * Return: the head request if one is found, otherwise %NULL.
 */
struct nfs_page *pnfs_generic_search_commit_reqs(struct nfs_commit_info *cinfo,
						 struct folio *folio)
{
	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
	struct pnfs_commit_array *array;
	struct nfs_page *req;

	list_for_each_entry(array, &fl_cinfo->commits, cinfo_list) {
		req = pnfs_bucket_search_commit_reqs(array->buckets,
						     array->nbuckets, folio);
		if (req)
			return req;
	}
	return NULL;
}
EXPORT_SYMBOL_GPL(pnfs_generic_search_commit_reqs);

static struct pnfs_layout_segment *
pnfs_bucket_get_committing(struct list_head *head,
			   struct pnfs_commit_bucket *bucket,
			   struct nfs_commit_info *cinfo)
{
	struct pnfs_layout_segment *lseg;
	struct list_head *pos;

	list_for_each(pos, &bucket->committing)
		cinfo->ds->ncommitting--;
	list_splice_init(&bucket->committing, head);
	lseg = pnfs_free_bucket_lseg(bucket);
	if (!lseg)
		lseg = pnfs_get_lseg(bucket->lseg);
	return lseg;
}

static struct nfs_commit_data *
pnfs_bucket_fetch_commitdata(struct pnfs_commit_bucket *bucket,
			     struct nfs_commit_info *cinfo)
{
	struct nfs_commit_data *data = nfs_commitdata_alloc();

	if (!data)
		return NULL;
	data->lseg = pnfs_bucket_get_committing(&data->pages, bucket, cinfo);
	return data;
}

static void pnfs_generic_retry_commit(struct pnfs_commit_bucket *buckets,
				      unsigned int nbuckets,
				      struct nfs_commit_info *cinfo,
				      unsigned int idx)
{
	struct pnfs_commit_bucket *bucket;
	struct pnfs_layout_segment *freeme;
	LIST_HEAD(pages);

	for (bucket = buckets; idx < nbuckets; bucket++, idx++) {
		if (list_empty(&bucket->committing))
			continue;
		mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
		freeme = pnfs_bucket_get_committing(&pages, bucket, cinfo);
		mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
		nfs_retry_commit(&pages, freeme, cinfo, idx);
		pnfs_put_lseg(freeme);
	}
}

static unsigned int
pnfs_bucket_alloc_ds_commits(struct list_head *list,
			     struct pnfs_commit_bucket *buckets,
			     unsigned int nbuckets,
			     struct nfs_commit_info *cinfo)
{
	struct pnfs_commit_bucket *bucket;
	struct nfs_commit_data *data;
	unsigned int i;
	unsigned int nreq = 0;

	for (i = 0, bucket = buckets; i < nbuckets; i++, bucket++) {
		if (list_empty(&bucket->committing))
			continue;
		mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
		if (!list_empty(&bucket->committing)) {
			data = pnfs_bucket_fetch_commitdata(bucket, cinfo);
			if (!data)
				goto out_error;
			data->ds_commit_index = i;
			list_add_tail(&data->list, list);
			nreq++;
		}
		mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
	}
	return nreq;
out_error:
	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
	/* Clean up on error */
	pnfs_generic_retry_commit(buckets, nbuckets, cinfo, i);
	return nreq;
}

static unsigned int
pnfs_alloc_ds_commits_list(struct list_head *list,
			   struct pnfs_ds_commit_info *fl_cinfo,
			   struct nfs_commit_info *cinfo)
{
	struct pnfs_commit_array *array;
	unsigned int ret = 0;

	rcu_read_lock();
	list_for_each_entry_rcu(array, &fl_cinfo->commits, cinfo_list) {
		if (!array->lseg || !pnfs_get_commit_array(array))
			continue;
		rcu_read_unlock();
		ret += pnfs_bucket_alloc_ds_commits(list, array->buckets,
				array->nbuckets, cinfo);
		rcu_read_lock();
		pnfs_put_commit_array(array, cinfo->inode);
	}
	rcu_read_unlock();
	return ret;
}

/* This follows nfs_commit_list pretty closely */
int
pnfs_generic_commit_pagelist(struct inode *inode, struct list_head *mds_pages,
			     int how, struct nfs_commit_info *cinfo,
			     int (*initiate_commit)(struct nfs_commit_data *data,
						    int how))
{
	struct pnfs_ds_commit_info *fl_cinfo = cinfo->ds;
	struct nfs_commit_data *data, *tmp;
	LIST_HEAD(list);
	unsigned int nreq = 0;

	if (!list_empty(mds_pages)) {
		data = nfs_commitdata_alloc();
		if (!data) {
			nfs_retry_commit(mds_pages, NULL, cinfo, -1);
			return -ENOMEM;
		}
		data->ds_commit_index = -1;
		list_splice_init(mds_pages, &data->pages);
		list_add_tail(&data->list, &list);
		nreq++;
	}

	nreq += pnfs_alloc_ds_commits_list(&list, fl_cinfo, cinfo);
	if (nreq == 0)
		goto out;

	list_for_each_entry_safe(data, tmp, &list, list) {
		list_del(&data->list);
		if (data->ds_commit_index < 0) {
			nfs_init_commit(data, NULL, NULL, cinfo);
			nfs_initiate_commit(NFS_CLIENT(inode), data,
					    NFS_PROTO(data->inode),
					    data->mds_ops, how,
					    RPC_TASK_CRED_NOREF);
		} else {
			nfs_init_commit(data, NULL, data->lseg, cinfo);
			initiate_commit(data, how);
		}
	}
out:
	return PNFS_ATTEMPTED;
}
EXPORT_SYMBOL_GPL(pnfs_generic_commit_pagelist);

/*
 * Data server cache
 *
 * Data servers can be mapped to different device ids.
 * nfs4_pnfs_ds reference counting
 *   - set to 1 on allocation
 *   - incremented when a device id maps a data server already in the cache.
 *   - decremented when deviceid is removed from the cache.
 */
static DEFINE_SPINLOCK(nfs4_ds_cache_lock);
static LIST_HEAD(nfs4_data_server_cache);

/* Debug routines */
static void
print_ds(struct nfs4_pnfs_ds *ds)
{
	if (ds == NULL) {
		printk(KERN_WARNING "%s NULL device\n", __func__);
		return;
	}
	printk(KERN_WARNING "        ds %s\n"
		"        ref count %d\n"
		"        client %p\n"
		"        cl_exchange_flags %x\n",
		ds->ds_remotestr,
		refcount_read(&ds->ds_count), ds->ds_clp,
		ds->ds_clp ? ds->ds_clp->cl_exchange_flags : 0);
}

static bool
same_sockaddr(struct sockaddr *addr1, struct sockaddr *addr2)
{
	struct sockaddr_in *a, *b;
	struct sockaddr_in6 *a6, *b6;

	if (addr1->sa_family != addr2->sa_family)
		return false;

	switch (addr1->sa_family) {
	case AF_INET:
		a = (struct sockaddr_in *)addr1;
		b = (struct sockaddr_in *)addr2;

		if (a->sin_addr.s_addr == b->sin_addr.s_addr &&
		    a->sin_port == b->sin_port)
			return true;
		break;

	case AF_INET6:
		a6 = (struct sockaddr_in6 *)addr1;
		b6 = (struct sockaddr_in6 *)addr2;

		/* LINKLOCAL addresses must have matching scope_id */
		if (ipv6_addr_src_scope(&a6->sin6_addr) ==
		    IPV6_ADDR_SCOPE_LINKLOCAL &&
		    a6->sin6_scope_id != b6->sin6_scope_id)
			return false;

		if (ipv6_addr_equal(&a6->sin6_addr, &b6->sin6_addr) &&
		    a6->sin6_port == b6->sin6_port)
			return true;
		break;

	default:
		dprintk("%s: unhandled address family: %u\n",
			__func__, addr1->sa_family);
		return false;
	}

	return false;
}

/*
 * Checks if 'dsaddrs1' contains a subset of 'dsaddrs2'. If it does,
 * declare a match.
 */
static bool
_same_data_server_addrs_locked(const struct list_head *dsaddrs1,
			       const struct list_head *dsaddrs2)
{
	struct nfs4_pnfs_ds_addr *da1, *da2;
	struct sockaddr *sa1, *sa2;
	bool match = false;

	list_for_each_entry(da1, dsaddrs1, da_node) {
		sa1 = (struct sockaddr *)&da1->da_addr;
		match = false;
		list_for_each_entry(da2, dsaddrs2, da_node) {
			sa2 = (struct sockaddr *)&da2->da_addr;
			match = same_sockaddr(sa1, sa2);
			if (match)
				break;
		}
		if (!match)
			break;
	}
	return match;
}

/*
 * Lookup DS by addresses.  nfs4_ds_cache_lock is held
 */
static struct nfs4_pnfs_ds *
_data_server_lookup_locked(const struct list_head *dsaddrs)
{
	struct nfs4_pnfs_ds *ds;

	list_for_each_entry(ds, &nfs4_data_server_cache, ds_node)
		if (_same_data_server_addrs_locked(&ds->ds_addrs, dsaddrs))
			return ds;
	return NULL;
}

static struct nfs4_pnfs_ds_addr *nfs4_pnfs_ds_addr_alloc(gfp_t gfp_flags)
{
	struct nfs4_pnfs_ds_addr *da = kzalloc(sizeof(*da), gfp_flags);
	if (da)
		INIT_LIST_HEAD(&da->da_node);
	return da;
}

static void nfs4_pnfs_ds_addr_free(struct nfs4_pnfs_ds_addr *da)
{
	kfree(da->da_remotestr);
	kfree(da->da_netid);
	kfree(da);
}

static void destroy_ds(struct nfs4_pnfs_ds *ds)
{
	struct nfs4_pnfs_ds_addr *da;

	dprintk("--> %s\n", __func__);
	ifdebug(FACILITY)
		print_ds(ds);

	nfs_put_client(ds->ds_clp);

	while (!list_empty(&ds->ds_addrs)) {
		da = list_first_entry(&ds->ds_addrs,
				      struct nfs4_pnfs_ds_addr,
				      da_node);
		list_del_init(&da->da_node);
		nfs4_pnfs_ds_addr_free(da);
	}

	kfree(ds->ds_remotestr);
	kfree(ds);
}

void nfs4_pnfs_ds_put(struct nfs4_pnfs_ds *ds)
{
	if (refcount_dec_and_lock(&ds->ds_count,
				&nfs4_ds_cache_lock)) {
		list_del_init(&ds->ds_node);
		spin_unlock(&nfs4_ds_cache_lock);
		destroy_ds(ds);
	}
}
EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_put);

/*
 * Create a string with a human readable address and port to avoid
 * complicated setup around many dprinks.
 */
static char *
nfs4_pnfs_remotestr(struct list_head *dsaddrs, gfp_t gfp_flags)
{
	struct nfs4_pnfs_ds_addr *da;
	char *remotestr;
	size_t len;
	char *p;

	len = 3;        /* '{', '}' and eol */
	list_for_each_entry(da, dsaddrs, da_node) {
		len += strlen(da->da_remotestr) + 1;    /* string plus comma */
	}

	remotestr = kzalloc(len, gfp_flags);
	if (!remotestr)
		return NULL;

	p = remotestr;
	*(p++) = '{';
	len--;
	list_for_each_entry(da, dsaddrs, da_node) {
		size_t ll = strlen(da->da_remotestr);

		if (ll > len)
			goto out_err;

		memcpy(p, da->da_remotestr, ll);
		p += ll;
		len -= ll;

		if (len < 1)
			goto out_err;
		(*p++) = ',';
		len--;
	}
	if (len < 2)
		goto out_err;
	*(p++) = '}';
	*p = '\0';
	return remotestr;
out_err:
	kfree(remotestr);
	return NULL;
}

/*
 * Given a list of multipath struct nfs4_pnfs_ds_addr, add it to ds cache if
 * uncached and return cached struct nfs4_pnfs_ds.
 */
struct nfs4_pnfs_ds *
nfs4_pnfs_ds_add(struct list_head *dsaddrs, gfp_t gfp_flags)
{
	struct nfs4_pnfs_ds *tmp_ds, *ds = NULL;
	char *remotestr;

	if (list_empty(dsaddrs)) {
		dprintk("%s: no addresses defined\n", __func__);
		goto out;
	}

	ds = kzalloc(sizeof(*ds), gfp_flags);
	if (!ds)
		goto out;

	/* this is only used for debugging, so it's ok if its NULL */
	remotestr = nfs4_pnfs_remotestr(dsaddrs, gfp_flags);

	spin_lock(&nfs4_ds_cache_lock);
	tmp_ds = _data_server_lookup_locked(dsaddrs);
	if (tmp_ds == NULL) {
		INIT_LIST_HEAD(&ds->ds_addrs);
		list_splice_init(dsaddrs, &ds->ds_addrs);
		ds->ds_remotestr = remotestr;
		refcount_set(&ds->ds_count, 1);
		INIT_LIST_HEAD(&ds->ds_node);
		ds->ds_clp = NULL;
		list_add(&ds->ds_node, &nfs4_data_server_cache);
		dprintk("%s add new data server %s\n", __func__,
			ds->ds_remotestr);
	} else {
		kfree(remotestr);
		kfree(ds);
		refcount_inc(&tmp_ds->ds_count);
		dprintk("%s data server %s found, inc'ed ds_count to %d\n",
			__func__, tmp_ds->ds_remotestr,
			refcount_read(&tmp_ds->ds_count));
		ds = tmp_ds;
	}
	spin_unlock(&nfs4_ds_cache_lock);
out:
	return ds;
}
EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_add);

static int nfs4_wait_ds_connect(struct nfs4_pnfs_ds *ds)
{
	might_sleep();
	return wait_on_bit(&ds->ds_state, NFS4DS_CONNECTING, TASK_KILLABLE);
}

static void nfs4_clear_ds_conn_bit(struct nfs4_pnfs_ds *ds)
{
	smp_mb__before_atomic();
	clear_and_wake_up_bit(NFS4DS_CONNECTING, &ds->ds_state);
}

static struct nfs_client *(*get_v3_ds_connect)(
			struct nfs_server *mds_srv,
			const struct sockaddr_storage *ds_addr,
			int ds_addrlen,
			int ds_proto,
			unsigned int ds_timeo,
			unsigned int ds_retrans);

static bool load_v3_ds_connect(void)
{
	if (!get_v3_ds_connect) {
		get_v3_ds_connect = symbol_request(nfs3_set_ds_client);
		WARN_ON_ONCE(!get_v3_ds_connect);
	}

	return(get_v3_ds_connect != NULL);
}

void nfs4_pnfs_v3_ds_connect_unload(void)
{
	if (get_v3_ds_connect) {
		symbol_put(nfs3_set_ds_client);
		get_v3_ds_connect = NULL;
	}
}

static int _nfs4_pnfs_v3_ds_connect(struct nfs_server *mds_srv,
				 struct nfs4_pnfs_ds *ds,
				 unsigned int timeo,
				 unsigned int retrans)
{
	struct nfs_client *clp = ERR_PTR(-EIO);
	struct nfs4_pnfs_ds_addr *da;
	unsigned long connect_timeout = timeo * (retrans + 1) * HZ / 10;
	int status = 0;

	dprintk("--> %s DS %s\n", __func__, ds->ds_remotestr);

	if (!load_v3_ds_connect())
		return -EPROTONOSUPPORT;

	list_for_each_entry(da, &ds->ds_addrs, da_node) {
		dprintk("%s: DS %s: trying address %s\n",
			__func__, ds->ds_remotestr, da->da_remotestr);

		if (!IS_ERR(clp)) {
			struct xprt_create xprt_args = {
				.ident = da->da_transport,
				.net = clp->cl_net,
				.dstaddr = (struct sockaddr *)&da->da_addr,
				.addrlen = da->da_addrlen,
				.servername = clp->cl_hostname,
				.connect_timeout = connect_timeout,
				.reconnect_timeout = connect_timeout,
			};

			if (da->da_transport != clp->cl_proto)
				continue;
			if (da->da_addr.ss_family != clp->cl_addr.ss_family)
				continue;
			/* Add this address as an alias */
			rpc_clnt_add_xprt(clp->cl_rpcclient, &xprt_args,
					rpc_clnt_test_and_add_xprt, NULL);
			continue;
		}
		clp = get_v3_ds_connect(mds_srv,
				&da->da_addr,
				da->da_addrlen, da->da_transport,
				timeo, retrans);
		if (IS_ERR(clp))
			continue;
		clp->cl_rpcclient->cl_softerr = 0;
		clp->cl_rpcclient->cl_softrtry = 0;
	}

	if (IS_ERR(clp)) {
		status = PTR_ERR(clp);
		goto out;
	}

	smp_wmb();
	WRITE_ONCE(ds->ds_clp, clp);
	dprintk("%s [new] addr: %s\n", __func__, ds->ds_remotestr);
out:
	return status;
}

static int _nfs4_pnfs_v4_ds_connect(struct nfs_server *mds_srv,
				 struct nfs4_pnfs_ds *ds,
				 unsigned int timeo,
				 unsigned int retrans,
				 u32 minor_version)
{
	struct nfs_client *clp = ERR_PTR(-EIO);
	struct nfs4_pnfs_ds_addr *da;
	int status = 0;

	dprintk("--> %s DS %s\n", __func__, ds->ds_remotestr);

	list_for_each_entry(da, &ds->ds_addrs, da_node) {
		dprintk("%s: DS %s: trying address %s\n",
			__func__, ds->ds_remotestr, da->da_remotestr);

		if (!IS_ERR(clp) && clp->cl_mvops->session_trunk) {
			struct xprt_create xprt_args = {
				.ident = da->da_transport,
				.net = clp->cl_net,
				.dstaddr = (struct sockaddr *)&da->da_addr,
				.addrlen = da->da_addrlen,
				.servername = clp->cl_hostname,
			};
			struct nfs4_add_xprt_data xprtdata = {
				.clp = clp,
			};
			struct rpc_add_xprt_test rpcdata = {
				.add_xprt_test = clp->cl_mvops->session_trunk,
				.data = &xprtdata,
			};

			if (da->da_transport != clp->cl_proto)
				continue;
			if (da->da_addr.ss_family != clp->cl_addr.ss_family)
				continue;
			/**
			* Test this address for session trunking and
			* add as an alias
			*/
			xprtdata.cred = nfs4_get_clid_cred(clp);
			rpc_clnt_add_xprt(clp->cl_rpcclient, &xprt_args,
					  rpc_clnt_setup_test_and_add_xprt,
					  &rpcdata);
			if (xprtdata.cred)
				put_cred(xprtdata.cred);
		} else {
			clp = nfs4_set_ds_client(mds_srv,
						&da->da_addr,
						da->da_addrlen,
						da->da_transport, timeo,
						retrans, minor_version);
			if (IS_ERR(clp))
				continue;

			status = nfs4_init_ds_session(clp,
					mds_srv->nfs_client->cl_lease_time);
			if (status) {
				nfs_put_client(clp);
				clp = ERR_PTR(-EIO);
				continue;
			}

		}
	}

	if (IS_ERR(clp)) {
		status = PTR_ERR(clp);
		goto out;
	}

	smp_wmb();
	WRITE_ONCE(ds->ds_clp, clp);
	dprintk("%s [new] addr: %s\n", __func__, ds->ds_remotestr);
out:
	return status;
}

/*
 * Create an rpc connection to the nfs4_pnfs_ds data server.
 * Currently only supports IPv4 and IPv6 addresses.
 * If connection fails, make devid unavailable and return a -errno.
 */
int nfs4_pnfs_ds_connect(struct nfs_server *mds_srv, struct nfs4_pnfs_ds *ds,
			  struct nfs4_deviceid_node *devid, unsigned int timeo,
			  unsigned int retrans, u32 version, u32 minor_version)
{
	int err;

	do {
		err = nfs4_wait_ds_connect(ds);
		if (err || ds->ds_clp)
			goto out;
		if (nfs4_test_deviceid_unavailable(devid))
			return -ENODEV;
	} while (test_and_set_bit(NFS4DS_CONNECTING, &ds->ds_state) != 0);

	if (ds->ds_clp)
		goto connect_done;

	switch (version) {
	case 3:
		err = _nfs4_pnfs_v3_ds_connect(mds_srv, ds, timeo, retrans);
		break;
	case 4:
		err = _nfs4_pnfs_v4_ds_connect(mds_srv, ds, timeo, retrans,
					       minor_version);
		break;
	default:
		dprintk("%s: unsupported DS version %d\n", __func__, version);
		err = -EPROTONOSUPPORT;
	}

connect_done:
	nfs4_clear_ds_conn_bit(ds);
out:
	/*
	 * At this point the ds->ds_clp should be ready, but it might have
	 * hit an error.
	 */
	if (!err) {
		if (!ds->ds_clp || !nfs_client_init_is_complete(ds->ds_clp)) {
			WARN_ON_ONCE(ds->ds_clp ||
				!nfs4_test_deviceid_unavailable(devid));
			return -EINVAL;
		}
		err = nfs_client_init_status(ds->ds_clp);
	}

	return err;
}
EXPORT_SYMBOL_GPL(nfs4_pnfs_ds_connect);

/*
 * Currently only supports ipv4, ipv6 and one multi-path address.
 */
struct nfs4_pnfs_ds_addr *
nfs4_decode_mp_ds_addr(struct net *net, struct xdr_stream *xdr, gfp_t gfp_flags)
{
	struct nfs4_pnfs_ds_addr *da = NULL;
	char *buf, *portstr;
	__be16 port;
	ssize_t nlen, rlen;
	int tmp[2];
	char *netid;
	size_t len;
	char *startsep = "";
	char *endsep = "";


	/* r_netid */
	nlen = xdr_stream_decode_string_dup(xdr, &netid, XDR_MAX_NETOBJ,
					    gfp_flags);
	if (unlikely(nlen < 0))
		goto out_err;

	/* r_addr: ip/ip6addr with port in dec octets - see RFC 5665 */
	/* port is ".ABC.DEF", 8 chars max */
	rlen = xdr_stream_decode_string_dup(xdr, &buf, INET6_ADDRSTRLEN +
					    IPV6_SCOPE_ID_LEN + 8, gfp_flags);
	if (unlikely(rlen < 0))
		goto out_free_netid;

	/* replace port '.' with '-' */
	portstr = strrchr(buf, '.');
	if (!portstr) {
		dprintk("%s: Failed finding expected dot in port\n",
			__func__);
		goto out_free_buf;
	}
	*portstr = '-';

	/* find '.' between address and port */
	portstr = strrchr(buf, '.');
	if (!portstr) {
		dprintk("%s: Failed finding expected dot between address and "
			"port\n", __func__);
		goto out_free_buf;
	}
	*portstr = '\0';

	da = nfs4_pnfs_ds_addr_alloc(gfp_flags);
	if (unlikely(!da))
		goto out_free_buf;

	if (!rpc_pton(net, buf, portstr-buf, (struct sockaddr *)&da->da_addr,
		      sizeof(da->da_addr))) {
		dprintk("%s: error parsing address %s\n", __func__, buf);
		goto out_free_da;
	}

	portstr++;
	sscanf(portstr, "%d-%d", &tmp[0], &tmp[1]);
	port = htons((tmp[0] << 8) | (tmp[1]));

	switch (da->da_addr.ss_family) {
	case AF_INET:
		((struct sockaddr_in *)&da->da_addr)->sin_port = port;
		da->da_addrlen = sizeof(struct sockaddr_in);
		break;

	case AF_INET6:
		((struct sockaddr_in6 *)&da->da_addr)->sin6_port = port;
		da->da_addrlen = sizeof(struct sockaddr_in6);
		startsep = "[";
		endsep = "]";
		break;

	default:
		dprintk("%s: unsupported address family: %u\n",
			__func__, da->da_addr.ss_family);
		goto out_free_da;
	}

	da->da_transport = xprt_find_transport_ident(netid);
	if (da->da_transport < 0) {
		dprintk("%s: ERROR: unknown r_netid \"%s\"\n",
			__func__, netid);
		goto out_free_da;
	}

	da->da_netid = netid;

	/* save human readable address */
	len = strlen(startsep) + strlen(buf) + strlen(endsep) + 7;
	da->da_remotestr = kzalloc(len, gfp_flags);

	/* NULL is ok, only used for dprintk */
	if (da->da_remotestr)
		snprintf(da->da_remotestr, len, "%s%s%s:%u", startsep,
			 buf, endsep, ntohs(port));

	dprintk("%s: Parsed DS addr %s\n", __func__, da->da_remotestr);
	kfree(buf);
	return da;

out_free_da:
	kfree(da);
out_free_buf:
	dprintk("%s: Error parsing DS addr: %s\n", __func__, buf);
	kfree(buf);
out_free_netid:
	kfree(netid);
out_err:
	return NULL;
}
EXPORT_SYMBOL_GPL(nfs4_decode_mp_ds_addr);

void
pnfs_layout_mark_request_commit(struct nfs_page *req,
				struct pnfs_layout_segment *lseg,
				struct nfs_commit_info *cinfo,
				u32 ds_commit_idx)
{
	struct list_head *list;
	struct pnfs_commit_array *array;
	struct pnfs_commit_bucket *bucket;

	mutex_lock(&NFS_I(cinfo->inode)->commit_mutex);
	array = pnfs_lookup_commit_array(cinfo->ds, lseg);
	if (!array || !pnfs_is_valid_lseg(lseg))
		goto out_resched;
	bucket = &array->buckets[ds_commit_idx];
	list = &bucket->written;
	/* Non-empty buckets hold a reference on the lseg.  That ref
	 * is normally transferred to the COMMIT call and released
	 * there.  It could also be released if the last req is pulled
	 * off due to a rewrite, in which case it will be done in
	 * pnfs_common_clear_request_commit
	 */
	if (!bucket->lseg)
		bucket->lseg = pnfs_get_lseg(lseg);
	set_bit(PG_COMMIT_TO_DS, &req->wb_flags);
	cinfo->ds->nwritten++;

	nfs_request_add_commit_list_locked(req, list, cinfo);
	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
	nfs_folio_mark_unstable(nfs_page_to_folio(req), cinfo);
	return;
out_resched:
	mutex_unlock(&NFS_I(cinfo->inode)->commit_mutex);
	cinfo->completion_ops->resched_write(cinfo, req);
}
EXPORT_SYMBOL_GPL(pnfs_layout_mark_request_commit);

int
pnfs_nfs_generic_sync(struct inode *inode, bool datasync)
{
	int ret;

	if (!pnfs_layoutcommit_outstanding(inode))
		return 0;
	ret = nfs_commit_inode(inode, FLUSH_SYNC);
	if (ret < 0)
		return ret;
	if (datasync)
		return 0;
	return pnfs_layoutcommit_inode(inode, true);
}
EXPORT_SYMBOL_GPL(pnfs_nfs_generic_sync);