xref: /linux/fs/nfsd/nfs3xdr.c (revision 0dd9ac63ce26ec87b080ca9c3e6efed33c23ace6)
1 /*
2  * XDR support for nfsd/protocol version 3.
3  *
4  * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
5  *
6  * 2003-08-09 Jamie Lokier: Use htonl() for nanoseconds, not htons()!
7  */
8 
9 #include <linux/namei.h>
10 #include "xdr3.h"
11 #include "auth.h"
12 
13 #define NFSDDBG_FACILITY		NFSDDBG_XDR
14 
15 
16 /*
17  * Mapping of S_IF* types to NFS file types
18  */
19 static u32	nfs3_ftypes[] = {
20 	NF3NON,  NF3FIFO, NF3CHR, NF3BAD,
21 	NF3DIR,  NF3BAD,  NF3BLK, NF3BAD,
22 	NF3REG,  NF3BAD,  NF3LNK, NF3BAD,
23 	NF3SOCK, NF3BAD,  NF3LNK, NF3BAD,
24 };
25 
26 /*
27  * XDR functions for basic NFS types
28  */
29 static __be32 *
30 encode_time3(__be32 *p, struct timespec *time)
31 {
32 	*p++ = htonl((u32) time->tv_sec); *p++ = htonl(time->tv_nsec);
33 	return p;
34 }
35 
36 static __be32 *
37 decode_time3(__be32 *p, struct timespec *time)
38 {
39 	time->tv_sec = ntohl(*p++);
40 	time->tv_nsec = ntohl(*p++);
41 	return p;
42 }
43 
44 static __be32 *
45 decode_fh(__be32 *p, struct svc_fh *fhp)
46 {
47 	unsigned int size;
48 	fh_init(fhp, NFS3_FHSIZE);
49 	size = ntohl(*p++);
50 	if (size > NFS3_FHSIZE)
51 		return NULL;
52 
53 	memcpy(&fhp->fh_handle.fh_base, p, size);
54 	fhp->fh_handle.fh_size = size;
55 	return p + XDR_QUADLEN(size);
56 }
57 
58 /* Helper function for NFSv3 ACL code */
59 __be32 *nfs3svc_decode_fh(__be32 *p, struct svc_fh *fhp)
60 {
61 	return decode_fh(p, fhp);
62 }
63 
64 static __be32 *
65 encode_fh(__be32 *p, struct svc_fh *fhp)
66 {
67 	unsigned int size = fhp->fh_handle.fh_size;
68 	*p++ = htonl(size);
69 	if (size) p[XDR_QUADLEN(size)-1]=0;
70 	memcpy(p, &fhp->fh_handle.fh_base, size);
71 	return p + XDR_QUADLEN(size);
72 }
73 
74 /*
75  * Decode a file name and make sure that the path contains
76  * no slashes or null bytes.
77  */
78 static __be32 *
79 decode_filename(__be32 *p, char **namp, unsigned int *lenp)
80 {
81 	char		*name;
82 	unsigned int	i;
83 
84 	if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS3_MAXNAMLEN)) != NULL) {
85 		for (i = 0, name = *namp; i < *lenp; i++, name++) {
86 			if (*name == '\0' || *name == '/')
87 				return NULL;
88 		}
89 	}
90 
91 	return p;
92 }
93 
94 static __be32 *
95 decode_sattr3(__be32 *p, struct iattr *iap)
96 {
97 	u32	tmp;
98 
99 	iap->ia_valid = 0;
100 
101 	if (*p++) {
102 		iap->ia_valid |= ATTR_MODE;
103 		iap->ia_mode = ntohl(*p++);
104 	}
105 	if (*p++) {
106 		iap->ia_valid |= ATTR_UID;
107 		iap->ia_uid = ntohl(*p++);
108 	}
109 	if (*p++) {
110 		iap->ia_valid |= ATTR_GID;
111 		iap->ia_gid = ntohl(*p++);
112 	}
113 	if (*p++) {
114 		u64	newsize;
115 
116 		iap->ia_valid |= ATTR_SIZE;
117 		p = xdr_decode_hyper(p, &newsize);
118 		if (newsize <= NFS_OFFSET_MAX)
119 			iap->ia_size = newsize;
120 		else
121 			iap->ia_size = NFS_OFFSET_MAX;
122 	}
123 	if ((tmp = ntohl(*p++)) == 1) {	/* set to server time */
124 		iap->ia_valid |= ATTR_ATIME;
125 	} else if (tmp == 2) {		/* set to client time */
126 		iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
127 		iap->ia_atime.tv_sec = ntohl(*p++);
128 		iap->ia_atime.tv_nsec = ntohl(*p++);
129 	}
130 	if ((tmp = ntohl(*p++)) == 1) {	/* set to server time */
131 		iap->ia_valid |= ATTR_MTIME;
132 	} else if (tmp == 2) {		/* set to client time */
133 		iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
134 		iap->ia_mtime.tv_sec = ntohl(*p++);
135 		iap->ia_mtime.tv_nsec = ntohl(*p++);
136 	}
137 	return p;
138 }
139 
140 static __be32 *encode_fsid(__be32 *p, struct svc_fh *fhp)
141 {
142 	u64 f;
143 	switch(fsid_source(fhp)) {
144 	default:
145 	case FSIDSOURCE_DEV:
146 		p = xdr_encode_hyper(p, (u64)huge_encode_dev
147 				     (fhp->fh_dentry->d_inode->i_sb->s_dev));
148 		break;
149 	case FSIDSOURCE_FSID:
150 		p = xdr_encode_hyper(p, (u64) fhp->fh_export->ex_fsid);
151 		break;
152 	case FSIDSOURCE_UUID:
153 		f = ((u64*)fhp->fh_export->ex_uuid)[0];
154 		f ^= ((u64*)fhp->fh_export->ex_uuid)[1];
155 		p = xdr_encode_hyper(p, f);
156 		break;
157 	}
158 	return p;
159 }
160 
161 static __be32 *
162 encode_fattr3(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
163 	      struct kstat *stat)
164 {
165 	*p++ = htonl(nfs3_ftypes[(stat->mode & S_IFMT) >> 12]);
166 	*p++ = htonl((u32) stat->mode);
167 	*p++ = htonl((u32) stat->nlink);
168 	*p++ = htonl((u32) nfsd_ruid(rqstp, stat->uid));
169 	*p++ = htonl((u32) nfsd_rgid(rqstp, stat->gid));
170 	if (S_ISLNK(stat->mode) && stat->size > NFS3_MAXPATHLEN) {
171 		p = xdr_encode_hyper(p, (u64) NFS3_MAXPATHLEN);
172 	} else {
173 		p = xdr_encode_hyper(p, (u64) stat->size);
174 	}
175 	p = xdr_encode_hyper(p, ((u64)stat->blocks) << 9);
176 	*p++ = htonl((u32) MAJOR(stat->rdev));
177 	*p++ = htonl((u32) MINOR(stat->rdev));
178 	p = encode_fsid(p, fhp);
179 	p = xdr_encode_hyper(p, stat->ino);
180 	p = encode_time3(p, &stat->atime);
181 	p = encode_time3(p, &stat->mtime);
182 	p = encode_time3(p, &stat->ctime);
183 
184 	return p;
185 }
186 
187 static __be32 *
188 encode_saved_post_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
189 {
190 	/* Attributes to follow */
191 	*p++ = xdr_one;
192 	return encode_fattr3(rqstp, p, fhp, &fhp->fh_post_attr);
193 }
194 
195 /*
196  * Encode post-operation attributes.
197  * The inode may be NULL if the call failed because of a stale file
198  * handle. In this case, no attributes are returned.
199  */
200 static __be32 *
201 encode_post_op_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
202 {
203 	struct dentry *dentry = fhp->fh_dentry;
204 	if (dentry && dentry->d_inode) {
205 	        int err;
206 		struct kstat stat;
207 
208 		err = vfs_getattr(fhp->fh_export->ex_path.mnt, dentry, &stat);
209 		if (!err) {
210 			*p++ = xdr_one;		/* attributes follow */
211 			lease_get_mtime(dentry->d_inode, &stat.mtime);
212 			return encode_fattr3(rqstp, p, fhp, &stat);
213 		}
214 	}
215 	*p++ = xdr_zero;
216 	return p;
217 }
218 
219 /* Helper for NFSv3 ACLs */
220 __be32 *
221 nfs3svc_encode_post_op_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
222 {
223 	return encode_post_op_attr(rqstp, p, fhp);
224 }
225 
226 /*
227  * Enocde weak cache consistency data
228  */
229 static __be32 *
230 encode_wcc_data(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
231 {
232 	struct dentry	*dentry = fhp->fh_dentry;
233 
234 	if (dentry && dentry->d_inode && fhp->fh_post_saved) {
235 		if (fhp->fh_pre_saved) {
236 			*p++ = xdr_one;
237 			p = xdr_encode_hyper(p, (u64) fhp->fh_pre_size);
238 			p = encode_time3(p, &fhp->fh_pre_mtime);
239 			p = encode_time3(p, &fhp->fh_pre_ctime);
240 		} else {
241 			*p++ = xdr_zero;
242 		}
243 		return encode_saved_post_attr(rqstp, p, fhp);
244 	}
245 	/* no pre- or post-attrs */
246 	*p++ = xdr_zero;
247 	return encode_post_op_attr(rqstp, p, fhp);
248 }
249 
250 /*
251  * Fill in the post_op attr for the wcc data
252  */
253 void fill_post_wcc(struct svc_fh *fhp)
254 {
255 	int err;
256 
257 	if (fhp->fh_post_saved)
258 		printk("nfsd: inode locked twice during operation.\n");
259 
260 	err = vfs_getattr(fhp->fh_export->ex_path.mnt, fhp->fh_dentry,
261 			&fhp->fh_post_attr);
262 	fhp->fh_post_change = fhp->fh_dentry->d_inode->i_version;
263 	if (err)
264 		fhp->fh_post_saved = 0;
265 	else
266 		fhp->fh_post_saved = 1;
267 }
268 
269 /*
270  * XDR decode functions
271  */
272 int
273 nfs3svc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p, struct nfsd_fhandle *args)
274 {
275 	if (!(p = decode_fh(p, &args->fh)))
276 		return 0;
277 	return xdr_argsize_check(rqstp, p);
278 }
279 
280 int
281 nfs3svc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p,
282 					struct nfsd3_sattrargs *args)
283 {
284 	if (!(p = decode_fh(p, &args->fh)))
285 		return 0;
286 	p = decode_sattr3(p, &args->attrs);
287 
288 	if ((args->check_guard = ntohl(*p++)) != 0) {
289 		struct timespec time;
290 		p = decode_time3(p, &time);
291 		args->guardtime = time.tv_sec;
292 	}
293 
294 	return xdr_argsize_check(rqstp, p);
295 }
296 
297 int
298 nfs3svc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p,
299 					struct nfsd3_diropargs *args)
300 {
301 	if (!(p = decode_fh(p, &args->fh))
302 	 || !(p = decode_filename(p, &args->name, &args->len)))
303 		return 0;
304 
305 	return xdr_argsize_check(rqstp, p);
306 }
307 
308 int
309 nfs3svc_decode_accessargs(struct svc_rqst *rqstp, __be32 *p,
310 					struct nfsd3_accessargs *args)
311 {
312 	if (!(p = decode_fh(p, &args->fh)))
313 		return 0;
314 	args->access = ntohl(*p++);
315 
316 	return xdr_argsize_check(rqstp, p);
317 }
318 
319 int
320 nfs3svc_decode_readargs(struct svc_rqst *rqstp, __be32 *p,
321 					struct nfsd3_readargs *args)
322 {
323 	unsigned int len;
324 	int v,pn;
325 	u32 max_blocksize = svc_max_payload(rqstp);
326 
327 	if (!(p = decode_fh(p, &args->fh)))
328 		return 0;
329 	p = xdr_decode_hyper(p, &args->offset);
330 
331 	len = args->count = ntohl(*p++);
332 
333 	if (len > max_blocksize)
334 		len = max_blocksize;
335 
336 	/* set up the kvec */
337 	v=0;
338 	while (len > 0) {
339 		pn = rqstp->rq_resused++;
340 		rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_respages[pn]);
341 		rqstp->rq_vec[v].iov_len = len < PAGE_SIZE? len : PAGE_SIZE;
342 		len -= rqstp->rq_vec[v].iov_len;
343 		v++;
344 	}
345 	args->vlen = v;
346 	return xdr_argsize_check(rqstp, p);
347 }
348 
349 int
350 nfs3svc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
351 					struct nfsd3_writeargs *args)
352 {
353 	unsigned int len, v, hdr, dlen;
354 	u32 max_blocksize = svc_max_payload(rqstp);
355 
356 	if (!(p = decode_fh(p, &args->fh)))
357 		return 0;
358 	p = xdr_decode_hyper(p, &args->offset);
359 
360 	args->count = ntohl(*p++);
361 	args->stable = ntohl(*p++);
362 	len = args->len = ntohl(*p++);
363 	/*
364 	 * The count must equal the amount of data passed.
365 	 */
366 	if (args->count != args->len)
367 		return 0;
368 
369 	/*
370 	 * Check to make sure that we got the right number of
371 	 * bytes.
372 	 */
373 	hdr = (void*)p - rqstp->rq_arg.head[0].iov_base;
374 	dlen = rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len
375 		- hdr;
376 	/*
377 	 * Round the length of the data which was specified up to
378 	 * the next multiple of XDR units and then compare that
379 	 * against the length which was actually received.
380 	 * Note that when RPCSEC/GSS (for example) is used, the
381 	 * data buffer can be padded so dlen might be larger
382 	 * than required.  It must never be smaller.
383 	 */
384 	if (dlen < XDR_QUADLEN(len)*4)
385 		return 0;
386 
387 	if (args->count > max_blocksize) {
388 		args->count = max_blocksize;
389 		len = args->len = max_blocksize;
390 	}
391 	rqstp->rq_vec[0].iov_base = (void*)p;
392 	rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr;
393 	v = 0;
394 	while (len > rqstp->rq_vec[v].iov_len) {
395 		len -= rqstp->rq_vec[v].iov_len;
396 		v++;
397 		rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_pages[v]);
398 		rqstp->rq_vec[v].iov_len = PAGE_SIZE;
399 	}
400 	rqstp->rq_vec[v].iov_len = len;
401 	args->vlen = v + 1;
402 	return 1;
403 }
404 
405 int
406 nfs3svc_decode_createargs(struct svc_rqst *rqstp, __be32 *p,
407 					struct nfsd3_createargs *args)
408 {
409 	if (!(p = decode_fh(p, &args->fh))
410 	 || !(p = decode_filename(p, &args->name, &args->len)))
411 		return 0;
412 
413 	switch (args->createmode = ntohl(*p++)) {
414 	case NFS3_CREATE_UNCHECKED:
415 	case NFS3_CREATE_GUARDED:
416 		p = decode_sattr3(p, &args->attrs);
417 		break;
418 	case NFS3_CREATE_EXCLUSIVE:
419 		args->verf = p;
420 		p += 2;
421 		break;
422 	default:
423 		return 0;
424 	}
425 
426 	return xdr_argsize_check(rqstp, p);
427 }
428 int
429 nfs3svc_decode_mkdirargs(struct svc_rqst *rqstp, __be32 *p,
430 					struct nfsd3_createargs *args)
431 {
432 	if (!(p = decode_fh(p, &args->fh)) ||
433 	    !(p = decode_filename(p, &args->name, &args->len)))
434 		return 0;
435 	p = decode_sattr3(p, &args->attrs);
436 
437 	return xdr_argsize_check(rqstp, p);
438 }
439 
440 int
441 nfs3svc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p,
442 					struct nfsd3_symlinkargs *args)
443 {
444 	unsigned int len, avail;
445 	char *old, *new;
446 	struct kvec *vec;
447 
448 	if (!(p = decode_fh(p, &args->ffh)) ||
449 	    !(p = decode_filename(p, &args->fname, &args->flen))
450 		)
451 		return 0;
452 	p = decode_sattr3(p, &args->attrs);
453 
454 	/* now decode the pathname, which might be larger than the first page.
455 	 * As we have to check for nul's anyway, we copy it into a new page
456 	 * This page appears in the rq_res.pages list, but as pages_len is always
457 	 * 0, it won't get in the way
458 	 */
459 	len = ntohl(*p++);
460 	if (len == 0 || len > NFS3_MAXPATHLEN || len >= PAGE_SIZE)
461 		return 0;
462 	args->tname = new =
463 		page_address(rqstp->rq_respages[rqstp->rq_resused++]);
464 	args->tlen = len;
465 	/* first copy and check from the first page */
466 	old = (char*)p;
467 	vec = &rqstp->rq_arg.head[0];
468 	avail = vec->iov_len - (old - (char*)vec->iov_base);
469 	while (len && avail && *old) {
470 		*new++ = *old++;
471 		len--;
472 		avail--;
473 	}
474 	/* now copy next page if there is one */
475 	if (len && !avail && rqstp->rq_arg.page_len) {
476 		avail = rqstp->rq_arg.page_len;
477 		if (avail > PAGE_SIZE)
478 			avail = PAGE_SIZE;
479 		old = page_address(rqstp->rq_arg.pages[0]);
480 	}
481 	while (len && avail && *old) {
482 		*new++ = *old++;
483 		len--;
484 		avail--;
485 	}
486 	*new = '\0';
487 	if (len)
488 		return 0;
489 
490 	return 1;
491 }
492 
493 int
494 nfs3svc_decode_mknodargs(struct svc_rqst *rqstp, __be32 *p,
495 					struct nfsd3_mknodargs *args)
496 {
497 	if (!(p = decode_fh(p, &args->fh))
498 	 || !(p = decode_filename(p, &args->name, &args->len)))
499 		return 0;
500 
501 	args->ftype = ntohl(*p++);
502 
503 	if (args->ftype == NF3BLK  || args->ftype == NF3CHR
504 	 || args->ftype == NF3SOCK || args->ftype == NF3FIFO)
505 		p = decode_sattr3(p, &args->attrs);
506 
507 	if (args->ftype == NF3BLK || args->ftype == NF3CHR) {
508 		args->major = ntohl(*p++);
509 		args->minor = ntohl(*p++);
510 	}
511 
512 	return xdr_argsize_check(rqstp, p);
513 }
514 
515 int
516 nfs3svc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p,
517 					struct nfsd3_renameargs *args)
518 {
519 	if (!(p = decode_fh(p, &args->ffh))
520 	 || !(p = decode_filename(p, &args->fname, &args->flen))
521 	 || !(p = decode_fh(p, &args->tfh))
522 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
523 		return 0;
524 
525 	return xdr_argsize_check(rqstp, p);
526 }
527 
528 int
529 nfs3svc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p,
530 					struct nfsd3_readlinkargs *args)
531 {
532 	if (!(p = decode_fh(p, &args->fh)))
533 		return 0;
534 	args->buffer =
535 		page_address(rqstp->rq_respages[rqstp->rq_resused++]);
536 
537 	return xdr_argsize_check(rqstp, p);
538 }
539 
540 int
541 nfs3svc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p,
542 					struct nfsd3_linkargs *args)
543 {
544 	if (!(p = decode_fh(p, &args->ffh))
545 	 || !(p = decode_fh(p, &args->tfh))
546 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
547 		return 0;
548 
549 	return xdr_argsize_check(rqstp, p);
550 }
551 
552 int
553 nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p,
554 					struct nfsd3_readdirargs *args)
555 {
556 	if (!(p = decode_fh(p, &args->fh)))
557 		return 0;
558 	p = xdr_decode_hyper(p, &args->cookie);
559 	args->verf   = p; p += 2;
560 	args->dircount = ~0;
561 	args->count  = ntohl(*p++);
562 
563 	if (args->count > PAGE_SIZE)
564 		args->count = PAGE_SIZE;
565 
566 	args->buffer =
567 		page_address(rqstp->rq_respages[rqstp->rq_resused++]);
568 
569 	return xdr_argsize_check(rqstp, p);
570 }
571 
572 int
573 nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, __be32 *p,
574 					struct nfsd3_readdirargs *args)
575 {
576 	int len, pn;
577 	u32 max_blocksize = svc_max_payload(rqstp);
578 
579 	if (!(p = decode_fh(p, &args->fh)))
580 		return 0;
581 	p = xdr_decode_hyper(p, &args->cookie);
582 	args->verf     = p; p += 2;
583 	args->dircount = ntohl(*p++);
584 	args->count    = ntohl(*p++);
585 
586 	len = (args->count > max_blocksize) ? max_blocksize :
587 						  args->count;
588 	args->count = len;
589 
590 	while (len > 0) {
591 		pn = rqstp->rq_resused++;
592 		if (!args->buffer)
593 			args->buffer = page_address(rqstp->rq_respages[pn]);
594 		len -= PAGE_SIZE;
595 	}
596 
597 	return xdr_argsize_check(rqstp, p);
598 }
599 
600 int
601 nfs3svc_decode_commitargs(struct svc_rqst *rqstp, __be32 *p,
602 					struct nfsd3_commitargs *args)
603 {
604 	if (!(p = decode_fh(p, &args->fh)))
605 		return 0;
606 	p = xdr_decode_hyper(p, &args->offset);
607 	args->count = ntohl(*p++);
608 
609 	return xdr_argsize_check(rqstp, p);
610 }
611 
612 /*
613  * XDR encode functions
614  */
615 /*
616  * There must be an encoding function for void results so svc_process
617  * will work properly.
618  */
619 int
620 nfs3svc_encode_voidres(struct svc_rqst *rqstp, __be32 *p, void *dummy)
621 {
622 	return xdr_ressize_check(rqstp, p);
623 }
624 
625 /* GETATTR */
626 int
627 nfs3svc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p,
628 					struct nfsd3_attrstat *resp)
629 {
630 	if (resp->status == 0) {
631 		lease_get_mtime(resp->fh.fh_dentry->d_inode,
632 				&resp->stat.mtime);
633 		p = encode_fattr3(rqstp, p, &resp->fh, &resp->stat);
634 	}
635 	return xdr_ressize_check(rqstp, p);
636 }
637 
638 /* SETATTR, REMOVE, RMDIR */
639 int
640 nfs3svc_encode_wccstat(struct svc_rqst *rqstp, __be32 *p,
641 					struct nfsd3_attrstat *resp)
642 {
643 	p = encode_wcc_data(rqstp, p, &resp->fh);
644 	return xdr_ressize_check(rqstp, p);
645 }
646 
647 /* LOOKUP */
648 int
649 nfs3svc_encode_diropres(struct svc_rqst *rqstp, __be32 *p,
650 					struct nfsd3_diropres *resp)
651 {
652 	if (resp->status == 0) {
653 		p = encode_fh(p, &resp->fh);
654 		p = encode_post_op_attr(rqstp, p, &resp->fh);
655 	}
656 	p = encode_post_op_attr(rqstp, p, &resp->dirfh);
657 	return xdr_ressize_check(rqstp, p);
658 }
659 
660 /* ACCESS */
661 int
662 nfs3svc_encode_accessres(struct svc_rqst *rqstp, __be32 *p,
663 					struct nfsd3_accessres *resp)
664 {
665 	p = encode_post_op_attr(rqstp, p, &resp->fh);
666 	if (resp->status == 0)
667 		*p++ = htonl(resp->access);
668 	return xdr_ressize_check(rqstp, p);
669 }
670 
671 /* READLINK */
672 int
673 nfs3svc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p,
674 					struct nfsd3_readlinkres *resp)
675 {
676 	p = encode_post_op_attr(rqstp, p, &resp->fh);
677 	if (resp->status == 0) {
678 		*p++ = htonl(resp->len);
679 		xdr_ressize_check(rqstp, p);
680 		rqstp->rq_res.page_len = resp->len;
681 		if (resp->len & 3) {
682 			/* need to pad the tail */
683 			rqstp->rq_res.tail[0].iov_base = p;
684 			*p = 0;
685 			rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
686 		}
687 		return 1;
688 	} else
689 		return xdr_ressize_check(rqstp, p);
690 }
691 
692 /* READ */
693 int
694 nfs3svc_encode_readres(struct svc_rqst *rqstp, __be32 *p,
695 					struct nfsd3_readres *resp)
696 {
697 	p = encode_post_op_attr(rqstp, p, &resp->fh);
698 	if (resp->status == 0) {
699 		*p++ = htonl(resp->count);
700 		*p++ = htonl(resp->eof);
701 		*p++ = htonl(resp->count);	/* xdr opaque count */
702 		xdr_ressize_check(rqstp, p);
703 		/* now update rqstp->rq_res to reflect data aswell */
704 		rqstp->rq_res.page_len = resp->count;
705 		if (resp->count & 3) {
706 			/* need to pad the tail */
707 			rqstp->rq_res.tail[0].iov_base = p;
708 			*p = 0;
709 			rqstp->rq_res.tail[0].iov_len = 4 - (resp->count & 3);
710 		}
711 		return 1;
712 	} else
713 		return xdr_ressize_check(rqstp, p);
714 }
715 
716 /* WRITE */
717 int
718 nfs3svc_encode_writeres(struct svc_rqst *rqstp, __be32 *p,
719 					struct nfsd3_writeres *resp)
720 {
721 	p = encode_wcc_data(rqstp, p, &resp->fh);
722 	if (resp->status == 0) {
723 		*p++ = htonl(resp->count);
724 		*p++ = htonl(resp->committed);
725 		*p++ = htonl(nfssvc_boot.tv_sec);
726 		*p++ = htonl(nfssvc_boot.tv_usec);
727 	}
728 	return xdr_ressize_check(rqstp, p);
729 }
730 
731 /* CREATE, MKDIR, SYMLINK, MKNOD */
732 int
733 nfs3svc_encode_createres(struct svc_rqst *rqstp, __be32 *p,
734 					struct nfsd3_diropres *resp)
735 {
736 	if (resp->status == 0) {
737 		*p++ = xdr_one;
738 		p = encode_fh(p, &resp->fh);
739 		p = encode_post_op_attr(rqstp, p, &resp->fh);
740 	}
741 	p = encode_wcc_data(rqstp, p, &resp->dirfh);
742 	return xdr_ressize_check(rqstp, p);
743 }
744 
745 /* RENAME */
746 int
747 nfs3svc_encode_renameres(struct svc_rqst *rqstp, __be32 *p,
748 					struct nfsd3_renameres *resp)
749 {
750 	p = encode_wcc_data(rqstp, p, &resp->ffh);
751 	p = encode_wcc_data(rqstp, p, &resp->tfh);
752 	return xdr_ressize_check(rqstp, p);
753 }
754 
755 /* LINK */
756 int
757 nfs3svc_encode_linkres(struct svc_rqst *rqstp, __be32 *p,
758 					struct nfsd3_linkres *resp)
759 {
760 	p = encode_post_op_attr(rqstp, p, &resp->fh);
761 	p = encode_wcc_data(rqstp, p, &resp->tfh);
762 	return xdr_ressize_check(rqstp, p);
763 }
764 
765 /* READDIR */
766 int
767 nfs3svc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p,
768 					struct nfsd3_readdirres *resp)
769 {
770 	p = encode_post_op_attr(rqstp, p, &resp->fh);
771 
772 	if (resp->status == 0) {
773 		/* stupid readdir cookie */
774 		memcpy(p, resp->verf, 8); p += 2;
775 		xdr_ressize_check(rqstp, p);
776 		if (rqstp->rq_res.head[0].iov_len + (2<<2) > PAGE_SIZE)
777 			return 1; /*No room for trailer */
778 		rqstp->rq_res.page_len = (resp->count) << 2;
779 
780 		/* add the 'tail' to the end of the 'head' page - page 0. */
781 		rqstp->rq_res.tail[0].iov_base = p;
782 		*p++ = 0;		/* no more entries */
783 		*p++ = htonl(resp->common.err == nfserr_eof);
784 		rqstp->rq_res.tail[0].iov_len = 2<<2;
785 		return 1;
786 	} else
787 		return xdr_ressize_check(rqstp, p);
788 }
789 
790 static __be32 *
791 encode_entry_baggage(struct nfsd3_readdirres *cd, __be32 *p, const char *name,
792 	     int namlen, u64 ino)
793 {
794 	*p++ = xdr_one;				 /* mark entry present */
795 	p    = xdr_encode_hyper(p, ino);	 /* file id */
796 	p    = xdr_encode_array(p, name, namlen);/* name length & name */
797 
798 	cd->offset = p;				/* remember pointer */
799 	p = xdr_encode_hyper(p, NFS_OFFSET_MAX);/* offset of next entry */
800 
801 	return p;
802 }
803 
804 static int
805 compose_entry_fh(struct nfsd3_readdirres *cd, struct svc_fh *fhp,
806 		const char *name, int namlen)
807 {
808 	struct svc_export	*exp;
809 	struct dentry		*dparent, *dchild;
810 	int rv = 0;
811 
812 	dparent = cd->fh.fh_dentry;
813 	exp  = cd->fh.fh_export;
814 
815 	if (isdotent(name, namlen)) {
816 		if (namlen == 2) {
817 			dchild = dget_parent(dparent);
818 			if (dchild == dparent) {
819 				/* filesystem root - cannot return filehandle for ".." */
820 				dput(dchild);
821 				return -ENOENT;
822 			}
823 		} else
824 			dchild = dget(dparent);
825 	} else
826 		dchild = lookup_one_len(name, dparent, namlen);
827 	if (IS_ERR(dchild))
828 		return -ENOENT;
829 	rv = -ENOENT;
830 	if (d_mountpoint(dchild))
831 		goto out;
832 	rv = fh_compose(fhp, exp, dchild, &cd->fh);
833 	if (rv)
834 		goto out;
835 	if (!dchild->d_inode)
836 		goto out;
837 	rv = 0;
838 out:
839 	dput(dchild);
840 	return rv;
841 }
842 
843 __be32 *encode_entryplus_baggage(struct nfsd3_readdirres *cd, __be32 *p, const char *name, int namlen)
844 {
845 	struct svc_fh	fh;
846 	int err;
847 
848 	fh_init(&fh, NFS3_FHSIZE);
849 	err = compose_entry_fh(cd, &fh, name, namlen);
850 	if (err) {
851 		*p++ = 0;
852 		*p++ = 0;
853 		goto out;
854 	}
855 	p = encode_post_op_attr(cd->rqstp, p, &fh);
856 	*p++ = xdr_one;			/* yes, a file handle follows */
857 	p = encode_fh(p, &fh);
858 out:
859 	fh_put(&fh);
860 	return p;
861 }
862 
863 /*
864  * Encode a directory entry. This one works for both normal readdir
865  * and readdirplus.
866  * The normal readdir reply requires 2 (fileid) + 1 (stringlen)
867  * + string + 2 (cookie) + 1 (next) words, i.e. 6 + strlen.
868  *
869  * The readdirplus baggage is 1+21 words for post_op_attr, plus the
870  * file handle.
871  */
872 
873 #define NFS3_ENTRY_BAGGAGE	(2 + 1 + 2 + 1)
874 #define NFS3_ENTRYPLUS_BAGGAGE	(1 + 21 + 1 + (NFS3_FHSIZE >> 2))
875 static int
876 encode_entry(struct readdir_cd *ccd, const char *name, int namlen,
877 	     loff_t offset, u64 ino, unsigned int d_type, int plus)
878 {
879 	struct nfsd3_readdirres *cd = container_of(ccd, struct nfsd3_readdirres,
880 		       					common);
881 	__be32		*p = cd->buffer;
882 	caddr_t		curr_page_addr = NULL;
883 	int		pn;		/* current page number */
884 	int		slen;		/* string (name) length */
885 	int		elen;		/* estimated entry length in words */
886 	int		num_entry_words = 0;	/* actual number of words */
887 
888 	if (cd->offset) {
889 		u64 offset64 = offset;
890 
891 		if (unlikely(cd->offset1)) {
892 			/* we ended up with offset on a page boundary */
893 			*cd->offset = htonl(offset64 >> 32);
894 			*cd->offset1 = htonl(offset64 & 0xffffffff);
895 			cd->offset1 = NULL;
896 		} else {
897 			xdr_encode_hyper(cd->offset, offset64);
898 		}
899 	}
900 
901 	/*
902 	dprintk("encode_entry(%.*s @%ld%s)\n",
903 		namlen, name, (long) offset, plus? " plus" : "");
904 	 */
905 
906 	/* truncate filename if too long */
907 	if (namlen > NFS3_MAXNAMLEN)
908 		namlen = NFS3_MAXNAMLEN;
909 
910 	slen = XDR_QUADLEN(namlen);
911 	elen = slen + NFS3_ENTRY_BAGGAGE
912 		+ (plus? NFS3_ENTRYPLUS_BAGGAGE : 0);
913 
914 	if (cd->buflen < elen) {
915 		cd->common.err = nfserr_toosmall;
916 		return -EINVAL;
917 	}
918 
919 	/* determine which page in rq_respages[] we are currently filling */
920 	for (pn=1; pn < cd->rqstp->rq_resused; pn++) {
921 		curr_page_addr = page_address(cd->rqstp->rq_respages[pn]);
922 
923 		if (((caddr_t)cd->buffer >= curr_page_addr) &&
924 		    ((caddr_t)cd->buffer <  curr_page_addr + PAGE_SIZE))
925 			break;
926 	}
927 
928 	if ((caddr_t)(cd->buffer + elen) < (curr_page_addr + PAGE_SIZE)) {
929 		/* encode entry in current page */
930 
931 		p = encode_entry_baggage(cd, p, name, namlen, ino);
932 
933 		if (plus)
934 			p = encode_entryplus_baggage(cd, p, name, namlen);
935 		num_entry_words = p - cd->buffer;
936 	} else if (cd->rqstp->rq_respages[pn+1] != NULL) {
937 		/* temporarily encode entry into next page, then move back to
938 		 * current and next page in rq_respages[] */
939 		__be32 *p1, *tmp;
940 		int len1, len2;
941 
942 		/* grab next page for temporary storage of entry */
943 		p1 = tmp = page_address(cd->rqstp->rq_respages[pn+1]);
944 
945 		p1 = encode_entry_baggage(cd, p1, name, namlen, ino);
946 
947 		if (plus)
948 			p1 = encode_entryplus_baggage(cd, p1, name, namlen);
949 
950 		/* determine entry word length and lengths to go in pages */
951 		num_entry_words = p1 - tmp;
952 		len1 = curr_page_addr + PAGE_SIZE - (caddr_t)cd->buffer;
953 		if ((num_entry_words << 2) < len1) {
954 			/* the actual number of words in the entry is less
955 			 * than elen and can still fit in the current page
956 			 */
957 			memmove(p, tmp, num_entry_words << 2);
958 			p += num_entry_words;
959 
960 			/* update offset */
961 			cd->offset = cd->buffer + (cd->offset - tmp);
962 		} else {
963 			unsigned int offset_r = (cd->offset - tmp) << 2;
964 
965 			/* update pointer to offset location.
966 			 * This is a 64bit quantity, so we need to
967 			 * deal with 3 cases:
968 			 *  -	entirely in first page
969 			 *  -	entirely in second page
970 			 *  -	4 bytes in each page
971 			 */
972 			if (offset_r + 8 <= len1) {
973 				cd->offset = p + (cd->offset - tmp);
974 			} else if (offset_r >= len1) {
975 				cd->offset -= len1 >> 2;
976 			} else {
977 				/* sitting on the fence */
978 				BUG_ON(offset_r != len1 - 4);
979 				cd->offset = p + (cd->offset - tmp);
980 				cd->offset1 = tmp;
981 			}
982 
983 			len2 = (num_entry_words << 2) - len1;
984 
985 			/* move from temp page to current and next pages */
986 			memmove(p, tmp, len1);
987 			memmove(tmp, (caddr_t)tmp+len1, len2);
988 
989 			p = tmp + (len2 >> 2);
990 		}
991 	}
992 	else {
993 		cd->common.err = nfserr_toosmall;
994 		return -EINVAL;
995 	}
996 
997 	cd->buflen -= num_entry_words;
998 	cd->buffer = p;
999 	cd->common.err = nfs_ok;
1000 	return 0;
1001 
1002 }
1003 
1004 int
1005 nfs3svc_encode_entry(void *cd, const char *name,
1006 		     int namlen, loff_t offset, u64 ino, unsigned int d_type)
1007 {
1008 	return encode_entry(cd, name, namlen, offset, ino, d_type, 0);
1009 }
1010 
1011 int
1012 nfs3svc_encode_entry_plus(void *cd, const char *name,
1013 			  int namlen, loff_t offset, u64 ino,
1014 			  unsigned int d_type)
1015 {
1016 	return encode_entry(cd, name, namlen, offset, ino, d_type, 1);
1017 }
1018 
1019 /* FSSTAT */
1020 int
1021 nfs3svc_encode_fsstatres(struct svc_rqst *rqstp, __be32 *p,
1022 					struct nfsd3_fsstatres *resp)
1023 {
1024 	struct kstatfs	*s = &resp->stats;
1025 	u64		bs = s->f_bsize;
1026 
1027 	*p++ = xdr_zero;	/* no post_op_attr */
1028 
1029 	if (resp->status == 0) {
1030 		p = xdr_encode_hyper(p, bs * s->f_blocks);	/* total bytes */
1031 		p = xdr_encode_hyper(p, bs * s->f_bfree);	/* free bytes */
1032 		p = xdr_encode_hyper(p, bs * s->f_bavail);	/* user available bytes */
1033 		p = xdr_encode_hyper(p, s->f_files);	/* total inodes */
1034 		p = xdr_encode_hyper(p, s->f_ffree);	/* free inodes */
1035 		p = xdr_encode_hyper(p, s->f_ffree);	/* user available inodes */
1036 		*p++ = htonl(resp->invarsec);	/* mean unchanged time */
1037 	}
1038 	return xdr_ressize_check(rqstp, p);
1039 }
1040 
1041 /* FSINFO */
1042 int
1043 nfs3svc_encode_fsinfores(struct svc_rqst *rqstp, __be32 *p,
1044 					struct nfsd3_fsinfores *resp)
1045 {
1046 	*p++ = xdr_zero;	/* no post_op_attr */
1047 
1048 	if (resp->status == 0) {
1049 		*p++ = htonl(resp->f_rtmax);
1050 		*p++ = htonl(resp->f_rtpref);
1051 		*p++ = htonl(resp->f_rtmult);
1052 		*p++ = htonl(resp->f_wtmax);
1053 		*p++ = htonl(resp->f_wtpref);
1054 		*p++ = htonl(resp->f_wtmult);
1055 		*p++ = htonl(resp->f_dtpref);
1056 		p = xdr_encode_hyper(p, resp->f_maxfilesize);
1057 		*p++ = xdr_one;
1058 		*p++ = xdr_zero;
1059 		*p++ = htonl(resp->f_properties);
1060 	}
1061 
1062 	return xdr_ressize_check(rqstp, p);
1063 }
1064 
1065 /* PATHCONF */
1066 int
1067 nfs3svc_encode_pathconfres(struct svc_rqst *rqstp, __be32 *p,
1068 					struct nfsd3_pathconfres *resp)
1069 {
1070 	*p++ = xdr_zero;	/* no post_op_attr */
1071 
1072 	if (resp->status == 0) {
1073 		*p++ = htonl(resp->p_link_max);
1074 		*p++ = htonl(resp->p_name_max);
1075 		*p++ = htonl(resp->p_no_trunc);
1076 		*p++ = htonl(resp->p_chown_restricted);
1077 		*p++ = htonl(resp->p_case_insensitive);
1078 		*p++ = htonl(resp->p_case_preserving);
1079 	}
1080 
1081 	return xdr_ressize_check(rqstp, p);
1082 }
1083 
1084 /* COMMIT */
1085 int
1086 nfs3svc_encode_commitres(struct svc_rqst *rqstp, __be32 *p,
1087 					struct nfsd3_commitres *resp)
1088 {
1089 	p = encode_wcc_data(rqstp, p, &resp->fh);
1090 	/* Write verifier */
1091 	if (resp->status == 0) {
1092 		*p++ = htonl(nfssvc_boot.tv_sec);
1093 		*p++ = htonl(nfssvc_boot.tv_usec);
1094 	}
1095 	return xdr_ressize_check(rqstp, p);
1096 }
1097 
1098 /*
1099  * XDR release functions
1100  */
1101 int
1102 nfs3svc_release_fhandle(struct svc_rqst *rqstp, __be32 *p,
1103 					struct nfsd3_attrstat *resp)
1104 {
1105 	fh_put(&resp->fh);
1106 	return 1;
1107 }
1108 
1109 int
1110 nfs3svc_release_fhandle2(struct svc_rqst *rqstp, __be32 *p,
1111 					struct nfsd3_fhandle_pair *resp)
1112 {
1113 	fh_put(&resp->fh1);
1114 	fh_put(&resp->fh2);
1115 	return 1;
1116 }
1117