aboutsummaryrefslogtreecommitdiffstats
path: root/fs/nfsd/nfs3xdr.c
blob: 623e13aa62595069e11ddaa3cb416c0f22a14c95 (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
/*
 * linux/fs/nfsd/nfs3xdr.c
 *
 * XDR support for nfsd/protocol version 3.
 *
 * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
 *
 * 2003-08-09 Jamie Lokier: Use htonl() for nanoseconds, not htons()!
 */

#include <linux/namei.h>
#include <linux/nfsd/xdr3.h>
#include "auth.h"

#define NFSDDBG_FACILITY		NFSDDBG_XDR


/*
 * Mapping of S_IF* types to NFS file types
 */
static u32	nfs3_ftypes[] = {
	NF3NON,  NF3FIFO, NF3CHR, NF3BAD,
	NF3DIR,  NF3BAD,  NF3BLK, NF3BAD,
	NF3REG,  NF3BAD,  NF3LNK, NF3BAD,
	NF3SOCK, NF3BAD,  NF3LNK, NF3BAD,
};

/*
 * XDR functions for basic NFS types
 */
static __be32 *
encode_time3(__be32 *p, struct timespec *time)
{
	*p++ = htonl((u32) time->tv_sec); *p++ = htonl(time->tv_nsec);
	return p;
}

static __be32 *
decode_time3(__be32 *p, struct timespec *time)
{
	time->tv_sec = ntohl(*p++);
	time->tv_nsec = ntohl(*p++);
	return p;
}

static __be32 *
decode_fh(__be32 *p, struct svc_fh *fhp)
{
	unsigned int size;
	fh_init(fhp, NFS3_FHSIZE);
	size = ntohl(*p++);
	if (size > NFS3_FHSIZE)
		return NULL;

	memcpy(&fhp->fh_handle.fh_base, p, size);
	fhp->fh_handle.fh_size = size;
	return p + XDR_QUADLEN(size);
}

/* Helper function for NFSv3 ACL code */
__be32 *nfs3svc_decode_fh(__be32 *p, struct svc_fh *fhp)
{
	return decode_fh(p, fhp);
}

static __be32 *
encode_fh(__be32 *p, struct svc_fh *fhp)
{
	unsigned int size = fhp->fh_handle.fh_size;
	*p++ = htonl(size);
	if (size) p[XDR_QUADLEN(size)-1]=0;
	memcpy(p, &fhp->fh_handle.fh_base, size);
	return p + XDR_QUADLEN(size);
}

/*
 * Decode a file name and make sure that the path contains
 * no slashes or null bytes.
 */
static __be32 *
decode_filename(__be32 *p, char **namp, unsigned int *lenp)
{
	char		*name;
	unsigned int	i;

	if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS3_MAXNAMLEN)) != NULL) {
		for (i = 0, name = *namp; i < *lenp; i++, name++) {
			if (*name == '\0' || *name == '/')
				return NULL;
		}
	}

	return p;
}

static __be32 *
decode_sattr3(__be32 *p, struct iattr *iap)
{
	u32	tmp;

	iap->ia_valid = 0;

	if (*p++) {
		iap->ia_valid |= ATTR_MODE;
		iap->ia_mode = ntohl(*p++);
	}
	if (*p++) {
		iap->ia_valid |= ATTR_UID;
		iap->ia_uid = ntohl(*p++);
	}
	if (*p++) {
		iap->ia_valid |= ATTR_GID;
		iap->ia_gid = ntohl(*p++);
	}
	if (*p++) {
		u64	newsize;

		iap->ia_valid |= ATTR_SIZE;
		p = xdr_decode_hyper(p, &newsize);
		if (newsize <= NFS_OFFSET_MAX)
			iap->ia_size = newsize;
		else
			iap->ia_size = NFS_OFFSET_MAX;
	}
	if ((tmp = ntohl(*p++)) == 1) {	/* set to server time */
		iap->ia_valid |= ATTR_ATIME;
	} else if (tmp == 2) {		/* set to client time */
		iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
		iap->ia_atime.tv_sec = ntohl(*p++);
		iap->ia_atime.tv_nsec = ntohl(*p++);
	}
	if ((tmp = ntohl(*p++)) == 1) {	/* set to server time */
		iap->ia_valid |= ATTR_MTIME;
	} else if (tmp == 2) {		/* set to client time */
		iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
		iap->ia_mtime.tv_sec = ntohl(*p++);
		iap->ia_mtime.tv_nsec = ntohl(*p++);
	}
	return p;
}

static __be32 *encode_fsid(__be32 *p, struct svc_fh *fhp)
{
	u64 f;
	switch(fsid_source(fhp)) {
	default:
	case FSIDSOURCE_DEV:
		p = xdr_encode_hyper(p, (u64)huge_encode_dev
				     (fhp->fh_dentry->d_inode->i_sb->s_dev));
		break;
	case FSIDSOURCE_FSID:
		p = xdr_encode_hyper(p, (u64) fhp->fh_export->ex_fsid);
		break;
	case FSIDSOURCE_UUID:
		f = ((u64*)fhp->fh_export->ex_uuid)[0];
		f ^= ((u64*)fhp->fh_export->ex_uuid)[1];
		p = xdr_encode_hyper(p, f);
		break;
	}
	return p;
}

static __be32 *
encode_fattr3(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
	      struct kstat *stat)
{
	*p++ = htonl(nfs3_ftypes[(stat->mode & S_IFMT) >> 12]);
	*p++ = htonl((u32) stat->mode);
	*p++ = htonl((u32) stat->nlink);
	*p++ = htonl((u32) nfsd_ruid(rqstp, stat->uid));
	*p++ = htonl((u32) nfsd_rgid(rqstp, stat->gid));
	if (S_ISLNK(stat->mode) && stat->size > NFS3_MAXPATHLEN) {
		p = xdr_encode_hyper(p, (u64) NFS3_MAXPATHLEN);
	} else {
		p = xdr_encode_hyper(p, (u64) stat->size);
	}
	p = xdr_encode_hyper(p, ((u64)stat->blocks) << 9);
	*p++ = htonl((u32) MAJOR(stat->rdev));
	*p++ = htonl((u32) MINOR(stat->rdev));
	p = encode_fsid(p, fhp);
	p = xdr_encode_hyper(p, stat->ino);
	p = encode_time3(p, &stat->atime);
	p = encode_time3(p, &stat->mtime);
	p = encode_time3(p, &stat->ctime);

	return p;
}

static __be32 *
encode_saved_post_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
{
	/* Attributes to follow */
	*p++ = xdr_one;
	return encode_fattr3(rqstp, p, fhp, &fhp->fh_post_attr);
}

/*
 * Encode post-operation attributes.
 * The inode may be NULL if the call failed because of a stale file
 * handle. In this case, no attributes are returned.
 */
static __be32 *
encode_post_op_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
{
	struct dentry *dentry = fhp->fh_dentry;
	if (dentry && dentry->d_inode) {
	        int err;
		struct kstat stat;

		err = vfs_getattr(fhp->fh_export->ex_path.mnt, dentry, &stat);
		if (!err) {
			*p++ = xdr_one;		/* attributes follow */
			lease_get_mtime(dentry->d_inode, &stat.mtime);
			return encode_fattr3(rqstp, p, fhp, &stat);
		}
	}
	*p++ = xdr_zero;
	return p;
}

/* Helper for NFSv3 ACLs */
__be32 *
nfs3svc_encode_post_op_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
{
	return encode_post_op_attr(rqstp, p, fhp);
}

/*
 * Enocde weak cache consistency data
 */
static __be32 *
encode_wcc_data(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
{
	struct dentry	*dentry = fhp->fh_dentry;

	if (dentry && dentry->d_inode && fhp->fh_post_saved) {
		if (fhp->fh_pre_saved) {
			*p++ = xdr_one;
			p = xdr_encode_hyper(p, (u64) fhp->fh_pre_size);
			p = encode_time3(p, &fhp->fh_pre_mtime);
			p = encode_time3(p, &fhp->fh_pre_ctime);
		} else {
			*p++ = xdr_zero;
		}
		return encode_saved_post_attr(rqstp, p, fhp);
	}
	/* no pre- or post-attrs */
	*p++ = xdr_zero;
	return encode_post_op_attr(rqstp, p, fhp);
}

/*
 * Fill in the post_op attr for the wcc data
 */
void fill_post_wcc(struct svc_fh *fhp)
{
	int err;

	if (fhp->fh_post_saved)
		printk("nfsd: inode locked twice during operation.\n");

	err = vfs_getattr(fhp->fh_export->ex_path.mnt, fhp->fh_dentry,
			&fhp->fh_post_attr);
	fhp->fh_post_change = fhp->fh_dentry->d_inode->i_version;
	if (err)
		fhp->fh_post_saved = 0;
	else
		fhp->fh_post_saved = 1;
}

/*
 * XDR decode functions
 */
int
nfs3svc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p, struct nfsd_fhandle *args)
{
	if (!(p = decode_fh(p, &args->fh)))
		return 0;
	return xdr_argsize_check(rqstp, p);
}

int
nfs3svc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_sattrargs *args)
{
	if (!(p = decode_fh(p, &args->fh)))
		return 0;
	p = decode_sattr3(p, &args->attrs);

	if ((args->check_guard = ntohl(*p++)) != 0) { 
		struct timespec time; 
		p = decode_time3(p, &time);
		args->guardtime = time.tv_sec;
	}

	return xdr_argsize_check(rqstp, p);
}

int
nfs3svc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_diropargs *args)
{
	if (!(p = decode_fh(p, &args->fh))
	 || !(p = decode_filename(p, &args->name, &args->len)))
		return 0;

	return xdr_argsize_check(rqstp, p);
}

int
nfs3svc_decode_accessargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_accessargs *args)
{
	if (!(p = decode_fh(p, &args->fh)))
		return 0;
	args->access = ntohl(*p++);

	return xdr_argsize_check(rqstp, p);
}

int
nfs3svc_decode_readargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_readargs *args)
{
	unsigned int len;
	int v,pn;
	u32 max_blocksize = svc_max_payload(rqstp);

	if (!(p = decode_fh(p, &args->fh)))
		return 0;
	p = xdr_decode_hyper(p, &args->offset);

	len = args->count = ntohl(*p++);

	if (len > max_blocksize)
		len = max_blocksize;

	/* set up the kvec */
	v=0;
	while (len > 0) {
		pn = rqstp->rq_resused++;
		rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_respages[pn]);
		rqstp->rq_vec[v].iov_len = len < PAGE_SIZE? len : PAGE_SIZE;
		len -= rqstp->rq_vec[v].iov_len;
		v++;
	}
	args->vlen = v;
	return xdr_argsize_check(rqstp, p);
}

int
nfs3svc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_writeargs *args)
{
	unsigned int len, v, hdr, dlen;
	u32 max_blocksize = svc_max_payload(rqstp);

	if (!(p = decode_fh(p, &args->fh)))
		return 0;
	p = xdr_decode_hyper(p, &args->offset);

	args->count = ntohl(*p++);
	args->stable = ntohl(*p++);
	len = args->len = ntohl(*p++);
	/*
	 * The count must equal the amount of data passed.
	 */
	if (args->count != args->len)
		return 0;

	/*
	 * Check to make sure that we got the right number of
	 * bytes.
	 */
	hdr = (void*)p - rqstp->rq_arg.head[0].iov_base;
	dlen = rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len
		- hdr;
	/*
	 * Round the length of the data which was specified up to
	 * the next multiple of XDR units and then compare that
	 * against the length which was actually received.
	 * Note that when RPCSEC/GSS (for example) is used, the
	 * data buffer can be padded so dlen might be larger
	 * than required.  It must never be smaller.
	 */
	if (dlen < XDR_QUADLEN(len)*4)
		return 0;

	if (args->count > max_blocksize) {
		args->count = max_blocksize;
		len = args->len = max_blocksize;
	}
	rqstp->rq_vec[0].iov_base = (void*)p;
	rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr;
	v = 0;
	while (len > rqstp->rq_vec[v].iov_len) {
		len -= rqstp->rq_vec[v].iov_len;
		v++;
		rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_pages[v]);
		rqstp->rq_vec[v].iov_len = PAGE_SIZE;
	}
	rqstp->rq_vec[v].iov_len = len;
	args->vlen = v + 1;
	return 1;
}

int
nfs3svc_decode_createargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_createargs *args)
{
	if (!(p = decode_fh(p, &args->fh))
	 || !(p = decode_filename(p, &args->name, &args->len)))
		return 0;

	switch (args->createmode = ntohl(*p++)) {
	case NFS3_CREATE_UNCHECKED:
	case NFS3_CREATE_GUARDED:
		p = decode_sattr3(p, &args->attrs);
		break;
	case NFS3_CREATE_EXCLUSIVE:
		args->verf = p;
		p += 2;
		break;
	default:
		return 0;
	}

	return xdr_argsize_check(rqstp, p);
}
int
nfs3svc_decode_mkdirargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_createargs *args)
{
	if (!(p = decode_fh(p, &args->fh)) ||
	    !(p = decode_filename(p, &args->name, &args->len)))
		return 0;
	p = decode_sattr3(p, &args->attrs);

	return xdr_argsize_check(rqstp, p);
}

int
nfs3svc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_symlinkargs *args)
{
	unsigned int len, avail;
	char *old, *new;
	struct kvec *vec;

	if (!(p = decode_fh(p, &args->ffh)) ||
	    !(p = decode_filename(p, &args->fname, &args->flen))
		)
		return 0;
	p = decode_sattr3(p, &args->attrs);

	/* now decode the pathname, which might be larger than the first page.
	 * As we have to check for nul's anyway, we copy it into a new page
	 * This page appears in the rq_res.pages list, but as pages_len is always
	 * 0, it won't get in the way
	 */
	len = ntohl(*p++);
	if (len == 0 || len > NFS3_MAXPATHLEN || len >= PAGE_SIZE)
		return 0;
	args->tname = new =
		page_address(rqstp->rq_respages[rqstp->rq_resused++]);
	args->tlen = len;
	/* first copy and check from the first page */
	old = (char*)p;
	vec = &rqstp->rq_arg.head[0];
	avail = vec->iov_len - (old - (char*)vec->iov_base);
	while (len && avail && *old) {
		*new++ = *old++;
		len--;
		avail--;
	}
	/* now copy next page if there is one */
	if (len && !avail && rqstp->rq_arg.page_len) {
		avail = rqstp->rq_arg.page_len;
		if (avail > PAGE_SIZE)
			avail = PAGE_SIZE;
		old = page_address(rqstp->rq_arg.pages[0]);
	}
	while (len && avail && *old) {
		*new++ = *old++;
		len--;
		avail--;
	}
	*new = '\0';
	if (len)
		return 0;

	return 1;
}

int
nfs3svc_decode_mknodargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_mknodargs *args)
{
	if (!(p = decode_fh(p, &args->fh))
	 || !(p = decode_filename(p, &args->name, &args->len)))
		return 0;

	args->ftype = ntohl(*p++);

	if (args->ftype == NF3BLK  || args->ftype == NF3CHR
	 || args->ftype == NF3SOCK || args->ftype == NF3FIFO)
		p = decode_sattr3(p, &args->attrs);

	if (args->ftype == NF3BLK || args->ftype == NF3CHR) {
		args->major = ntohl(*p++);
		args->minor = ntohl(*p++);
	}

	return xdr_argsize_check(rqstp, p);
}

int
nfs3svc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_renameargs *args)
{
	if (!(p = decode_fh(p, &args->ffh))
	 || !(p = decode_filename(p, &args->fname, &args->flen))
	 || !(p = decode_fh(p, &args->tfh))
	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
		return 0;

	return xdr_argsize_check(rqstp, p);
}

int
nfs3svc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_readlinkargs *args)
{
	if (!(p = decode_fh(p, &args->fh)))
		return 0;
	args->buffer =
		page_address(rqstp->rq_respages[rqstp->rq_resused++]);

	return xdr_argsize_check(rqstp, p);
}

int
nfs3svc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_linkargs *args)
{
	if (!(p = decode_fh(p, &args->ffh))
	 || !(p = decode_fh(p, &args->tfh))
	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
		return 0;

	return xdr_argsize_check(rqstp, p);
}

int
nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_readdirargs *args)
{
	if (!(p = decode_fh(p, &args->fh)))
		return 0;
	p = xdr_decode_hyper(p, &args->cookie);
	args->verf   = p; p += 2;
	args->dircount = ~0;
	args->count  = ntohl(*p++);

	if (args->count > PAGE_SIZE)
		args->count = PAGE_SIZE;

	args->buffer =
		page_address(rqstp->rq_respages[rqstp->rq_resused++]);

	return xdr_argsize_check(rqstp, p);
}

int
nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_readdirargs *args)
{
	int len, pn;
	u32 max_blocksize = svc_max_payload(rqstp);

	if (!(p = decode_fh(p, &args->fh)))
		return 0;
	p = xdr_decode_hyper(p, &args->cookie);
	args->verf     = p; p += 2;
	args->dircount = ntohl(*p++);
	args->count    = ntohl(*p++);

	len = (args->count > max_blocksize) ? max_blocksize :
						  args->count;
	args->count = len;

	while (len > 0) {
		pn = rqstp->rq_resused++;
		if (!args->buffer)
			args->buffer = page_address(rqstp->rq_respages[pn]);
		len -= PAGE_SIZE;
	}

	return xdr_argsize_check(rqstp, p);
}

int
nfs3svc_decode_commitargs(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_commitargs *args)
{
	if (!(p = decode_fh(p, &args->fh)))
		return 0;
	p = xdr_decode_hyper(p, &args->offset);
	args->count = ntohl(*p++);

	return xdr_argsize_check(rqstp, p);
}

/*
 * XDR encode functions
 */
/*
 * There must be an encoding function for void results so svc_process
 * will work properly.
 */
int
nfs3svc_encode_voidres(struct svc_rqst *rqstp, __be32 *p, void *dummy)
{
	return xdr_ressize_check(rqstp, p);
}

/* GETATTR */
int
nfs3svc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_attrstat *resp)
{
	if (resp->status == 0) {
		lease_get_mtime(resp->fh.fh_dentry->d_inode,
				&resp->stat.mtime);
		p = encode_fattr3(rqstp, p, &resp->fh, &resp->stat);
	}
	return xdr_ressize_check(rqstp, p);
}

/* SETATTR, REMOVE, RMDIR */
int
nfs3svc_encode_wccstat(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_attrstat *resp)
{
	p = encode_wcc_data(rqstp, p, &resp->fh);
	return xdr_ressize_check(rqstp, p);
}

/* LOOKUP */
int
nfs3svc_encode_diropres(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_diropres *resp)
{
	if (resp->status == 0) {
		p = encode_fh(p, &resp->fh);
		p = encode_post_op_attr(rqstp, p, &resp->fh);
	}
	p = encode_post_op_attr(rqstp, p, &resp->dirfh);
	return xdr_ressize_check(rqstp, p);
}

/* ACCESS */
int
nfs3svc_encode_accessres(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_accessres *resp)
{
	p = encode_post_op_attr(rqstp, p, &resp->fh);
	if (resp->status == 0)
		*p++ = htonl(resp->access);
	return xdr_ressize_check(rqstp, p);
}

/* READLINK */
int
nfs3svc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_readlinkres *resp)
{
	p = encode_post_op_attr(rqstp, p, &resp->fh);
	if (resp->status == 0) {
		*p++ = htonl(resp->len);
		xdr_ressize_check(rqstp, p);
		rqstp->rq_res.page_len = resp->len;
		if (resp->len & 3) {
			/* need to pad the tail */
			rqstp->rq_res.tail[0].iov_base = p;
			*p = 0;
			rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
		}
		return 1;
	} else
		return xdr_ressize_check(rqstp, p);
}

/* READ */
int
nfs3svc_encode_readres(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_readres *resp)
{
	p = encode_post_op_attr(rqstp, p, &resp->fh);
	if (resp->status == 0) {
		*p++ = htonl(resp->count);
		*p++ = htonl(resp->eof);
		*p++ = htonl(resp->count);	/* xdr opaque count */
		xdr_ressize_check(rqstp, p);
		/* now update rqstp->rq_res to reflect data aswell */
		rqstp->rq_res.page_len = resp->count;
		if (resp->count & 3) {
			/* need to pad the tail */
			rqstp->rq_res.tail[0].iov_base = p;
			*p = 0;
			rqstp->rq_res.tail[0].iov_len = 4 - (resp->count & 3);
		}
		return 1;
	} else
		return xdr_ressize_check(rqstp, p);
}

/* WRITE */
int
nfs3svc_encode_writeres(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_writeres *resp)
{
	p = encode_wcc_data(rqstp, p, &resp->fh);
	if (resp->status == 0) {
		*p++ = htonl(resp->count);
		*p++ = htonl(resp->committed);
		*p++ = htonl(nfssvc_boot.tv_sec);
		*p++ = htonl(nfssvc_boot.tv_usec);
	}
	return xdr_ressize_check(rqstp, p);
}

/* CREATE, MKDIR, SYMLINK, MKNOD */
int
nfs3svc_encode_createres(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_diropres *resp)
{
	if (resp->status == 0) {
		*p++ = xdr_one;
		p = encode_fh(p, &resp->fh);
		p = encode_post_op_attr(rqstp, p, &resp->fh);
	}
	p = encode_wcc_data(rqstp, p, &resp->dirfh);
	return xdr_ressize_check(rqstp, p);
}

/* RENAME */
int
nfs3svc_encode_renameres(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_renameres *resp)
{
	p = encode_wcc_data(rqstp, p, &resp->ffh);
	p = encode_wcc_data(rqstp, p, &resp->tfh);
	return xdr_ressize_check(rqstp, p);
}

/* LINK */
int
nfs3svc_encode_linkres(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_linkres *resp)
{
	p = encode_post_op_attr(rqstp, p, &resp->fh);
	p = encode_wcc_data(rqstp, p, &resp->tfh);
	return xdr_ressize_check(rqstp, p);
}

/* READDIR */
int
nfs3svc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_readdirres *resp)
{
	p = encode_post_op_attr(rqstp, p, &resp->fh);

	if (resp->status == 0) {
		/* stupid readdir cookie */
		memcpy(p, resp->verf, 8); p += 2;
		xdr_ressize_check(rqstp, p);
		if (rqstp->rq_res.head[0].iov_len + (2<<2) > PAGE_SIZE)
			return 1; /*No room for trailer */
		rqstp->rq_res.page_len = (resp->count) << 2;

		/* add the 'tail' to the end of the 'head' page - page 0. */
		rqstp->rq_res.tail[0].iov_base = p;
		*p++ = 0;		/* no more entries */
		*p++ = htonl(resp->common.err == nfserr_eof);
		rqstp->rq_res.tail[0].iov_len = 2<<2;
		return 1;
	} else
		return xdr_ressize_check(rqstp, p);
}

static __be32 *
encode_entry_baggage(struct nfsd3_readdirres *cd, __be32 *p, const char *name,
	     int namlen, u64 ino)
{
	*p++ = xdr_one;				 /* mark entry present */
	p    = xdr_encode_hyper(p, ino);	 /* file id */
	p    = xdr_encode_array(p, name, namlen);/* name length & name */

	cd->offset = p;				/* remember pointer */
	p = xdr_encode_hyper(p, NFS_OFFSET_MAX);/* offset of next entry */

	return p;
}

static int
compose_entry_fh(struct nfsd3_readdirres *cd, struct svc_fh *fhp,
		const char *name, int namlen)
{
	struct svc_export	*exp;
	struct dentry		*dparent, *dchild;
	int rv = 0;

	dparent = cd->fh.fh_dentry;
	exp  = cd->fh.fh_export;

	if (isdotent(name, namlen)) {
		if (namlen == 2) {
			dchild = dget_parent(dparent);
			if (dchild == dparent) {
				/* filesystem root - cannot return filehandle for ".." */
				dput(dchild);
				return -ENOENT;
			}
		} else
			dchild = dget(dparent);
	} else
		dchild = lookup_one_len(name, dparent, namlen);
	if (IS_ERR(dchild))
		return -ENOENT;
	rv = -ENOENT;
	if (d_mountpoint(dchild))
		goto out;
	rv = fh_compose(fhp, exp, dchild, &cd->fh);
	if (rv)
		goto out;
	if (!dchild->d_inode)
		goto out;
	rv = 0;
out:
	dput(dchild);
	return rv;
}

__be32 *encode_entryplus_baggage(struct nfsd3_readdirres *cd, __be32 *p, const char *name, int namlen)
{
	struct svc_fh	fh;
	int err;

	fh_init(&fh, NFS3_FHSIZE);
	err = compose_entry_fh(cd, &fh, name, namlen);
	if (err) {
		*p++ = 0;
		*p++ = 0;
		goto out;
	}
	p = encode_post_op_attr(cd->rqstp, p, &fh);
	*p++ = xdr_one;			/* yes, a file handle follows */
	p = encode_fh(p, &fh);
out:
	fh_put(&fh);
	return p;
}

/*
 * Encode a directory entry. This one works for both normal readdir
 * and readdirplus.
 * The normal readdir reply requires 2 (fileid) + 1 (stringlen)
 * + string + 2 (cookie) + 1 (next) words, i.e. 6 + strlen.
 * 
 * The readdirplus baggage is 1+21 words for post_op_attr, plus the
 * file handle.
 */

#define NFS3_ENTRY_BAGGAGE	(2 + 1 + 2 + 1)
#define NFS3_ENTRYPLUS_BAGGAGE	(1 + 21 + 1 + (NFS3_FHSIZE >> 2))
static int
encode_entry(struct readdir_cd *ccd, const char *name, int namlen,
	     loff_t offset, u64 ino, unsigned int d_type, int plus)
{
	struct nfsd3_readdirres *cd = container_of(ccd, struct nfsd3_readdirres,
		       					common);
	__be32		*p = cd->buffer;
	caddr_t		curr_page_addr = NULL;
	int		pn;		/* current page number */
	int		slen;		/* string (name) length */
	int		elen;		/* estimated entry length in words */
	int		num_entry_words = 0;	/* actual number of words */

	if (cd->offset) {
		u64 offset64 = offset;

		if (unlikely(cd->offset1)) {
			/* we ended up with offset on a page boundary */
			*cd->offset = htonl(offset64 >> 32);
			*cd->offset1 = htonl(offset64 & 0xffffffff);
			cd->offset1 = NULL;
		} else {
			xdr_encode_hyper(cd->offset, offset64);
		}
	}

	/*
	dprintk("encode_entry(%.*s @%ld%s)\n",
		namlen, name, (long) offset, plus? " plus" : "");
	 */

	/* truncate filename if too long */
	if (namlen > NFS3_MAXNAMLEN)
		namlen = NFS3_MAXNAMLEN;

	slen = XDR_QUADLEN(namlen);
	elen = slen + NFS3_ENTRY_BAGGAGE
		+ (plus? NFS3_ENTRYPLUS_BAGGAGE : 0);

	if (cd->buflen < elen) {
		cd->common.err = nfserr_toosmall;
		return -EINVAL;
	}

	/* determine which page in rq_respages[] we are currently filling */
	for (pn=1; pn < cd->rqstp->rq_resused; pn++) {
		curr_page_addr = page_address(cd->rqstp->rq_respages[pn]);

		if (((caddr_t)cd->buffer >= curr_page_addr) &&
		    ((caddr_t)cd->buffer <  curr_page_addr + PAGE_SIZE))
			break;
	}

	if ((caddr_t)(cd->buffer + elen) < (curr_page_addr + PAGE_SIZE)) {
		/* encode entry in current page */

		p = encode_entry_baggage(cd, p, name, namlen, ino);

		if (plus)
			p = encode_entryplus_baggage(cd, p, name, namlen);
		num_entry_words = p - cd->buffer;
	} else if (cd->rqstp->rq_respages[pn+1] != NULL) {
		/* temporarily encode entry into next page, then move back to
		 * current and next page in rq_respages[] */
		__be32 *p1, *tmp;
		int len1, len2;

		/* grab next page for temporary storage of entry */
		p1 = tmp = page_address(cd->rqstp->rq_respages[pn+1]);

		p1 = encode_entry_baggage(cd, p1, name, namlen, ino);

		if (plus)
			p1 = encode_entryplus_baggage(cd, p1, name, namlen);

		/* determine entry word length and lengths to go in pages */
		num_entry_words = p1 - tmp;
		len1 = curr_page_addr + PAGE_SIZE - (caddr_t)cd->buffer;
		if ((num_entry_words << 2) < len1) {
			/* the actual number of words in the entry is less
			 * than elen and can still fit in the current page
			 */
			memmove(p, tmp, num_entry_words << 2);
			p += num_entry_words;

			/* update offset */
			cd->offset = cd->buffer + (cd->offset - tmp);
		} else {
			unsigned int offset_r = (cd->offset - tmp) << 2;

			/* update pointer to offset location.
			 * This is a 64bit quantity, so we need to
			 * deal with 3 cases:
			 *  -	entirely in first page
			 *  -	entirely in second page
			 *  -	4 bytes in each page
			 */
			if (offset_r + 8 <= len1) {
				cd->offset = p + (cd->offset - tmp);
			} else if (offset_r >= len1) {
				cd->offset -= len1 >> 2;
			} else {
				/* sitting on the fence */
				BUG_ON(offset_r != len1 - 4);
				cd->offset = p + (cd->offset - tmp);
				cd->offset1 = tmp;
			}

			len2 = (num_entry_words << 2) - len1;

			/* move from temp page to current and next pages */
			memmove(p, tmp, len1);
			memmove(tmp, (caddr_t)tmp+len1, len2);

			p = tmp + (len2 >> 2);
		}
	}
	else {
		cd->common.err = nfserr_toosmall;
		return -EINVAL;
	}

	cd->buflen -= num_entry_words;
	cd->buffer = p;
	cd->common.err = nfs_ok;
	return 0;

}

int
nfs3svc_encode_entry(void *cd, const char *name,
		     int namlen, loff_t offset, u64 ino, unsigned int d_type)
{
	return encode_entry(cd, name, namlen, offset, ino, d_type, 0);
}

int
nfs3svc_encode_entry_plus(void *cd, const char *name,
			  int namlen, loff_t offset, u64 ino,
			  unsigned int d_type)
{
	return encode_entry(cd, name, namlen, offset, ino, d_type, 1);
}

/* FSSTAT */
int
nfs3svc_encode_fsstatres(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_fsstatres *resp)
{
	struct kstatfs	*s = &resp->stats;
	u64		bs = s->f_bsize;

	*p++ = xdr_zero;	/* no post_op_attr */

	if (resp->status == 0) {
		p = xdr_encode_hyper(p, bs * s->f_blocks);	/* total bytes */
		p = xdr_encode_hyper(p, bs * s->f_bfree);	/* free bytes */
		p = xdr_encode_hyper(p, bs * s->f_bavail);	/* user available bytes */
		p = xdr_encode_hyper(p, s->f_files);	/* total inodes */
		p = xdr_encode_hyper(p, s->f_ffree);	/* free inodes */
		p = xdr_encode_hyper(p, s->f_ffree);	/* user available inodes */
		*p++ = htonl(resp->invarsec);	/* mean unchanged time */
	}
	return xdr_ressize_check(rqstp, p);
}

/* FSINFO */
int
nfs3svc_encode_fsinfores(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_fsinfores *resp)
{
	*p++ = xdr_zero;	/* no post_op_attr */

	if (resp->status == 0) {
		*p++ = htonl(resp->f_rtmax);
		*p++ = htonl(resp->f_rtpref);
		*p++ = htonl(resp->f_rtmult);
		*p++ = htonl(resp->f_wtmax);
		*p++ = htonl(resp->f_wtpref);
		*p++ = htonl(resp->f_wtmult);
		*p++ = htonl(resp->f_dtpref);
		p = xdr_encode_hyper(p, resp->f_maxfilesize);
		*p++ = xdr_one;
		*p++ = xdr_zero;
		*p++ = htonl(resp->f_properties);
	}

	return xdr_ressize_check(rqstp, p);
}

/* PATHCONF */
int
nfs3svc_encode_pathconfres(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_pathconfres *resp)
{
	*p++ = xdr_zero;	/* no post_op_attr */

	if (resp->status == 0) {
		*p++ = htonl(resp->p_link_max);
		*p++ = htonl(resp->p_name_max);
		*p++ = htonl(resp->p_no_trunc);
		*p++ = htonl(resp->p_chown_restricted);
		*p++ = htonl(resp->p_case_insensitive);
		*p++ = htonl(resp->p_case_preserving);
	}

	return xdr_ressize_check(rqstp, p);
}

/* COMMIT */
int
nfs3svc_encode_commitres(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_commitres *resp)
{
	p = encode_wcc_data(rqstp, p, &resp->fh);
	/* Write verifier */
	if (resp->status == 0) {
		*p++ = htonl(nfssvc_boot.tv_sec);
		*p++ = htonl(nfssvc_boot.tv_usec);
	}
	return xdr_ressize_check(rqstp, p);
}

/*
 * XDR release functions
 */
int
nfs3svc_release_fhandle(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_attrstat *resp)
{
	fh_put(&resp->fh);
	return 1;
}

int
nfs3svc_release_fhandle2(struct svc_rqst *rqstp, __be32 *p,
					struct nfsd3_fhandle_pair *resp)
{
	fh_put(&resp->fh1);
	fh_put(&resp->fh2);
	return 1;
}