xref: /openbmc/linux/fs/nfsd/nfs3xdr.c (revision 8e9356c6)
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 <linux/sunrpc/svc_xprt.h>
11 #include "xdr3.h"
12 #include "auth.h"
13 #include "netns.h"
14 #include "vfs.h"
15 
16 #define NFSDDBG_FACILITY		NFSDDBG_XDR
17 
18 
19 /*
20  * Mapping of S_IF* types to NFS file types
21  */
22 static u32	nfs3_ftypes[] = {
23 	NF3NON,  NF3FIFO, NF3CHR, NF3BAD,
24 	NF3DIR,  NF3BAD,  NF3BLK, NF3BAD,
25 	NF3REG,  NF3BAD,  NF3LNK, NF3BAD,
26 	NF3SOCK, NF3BAD,  NF3LNK, NF3BAD,
27 };
28 
29 /*
30  * XDR functions for basic NFS types
31  */
32 static __be32 *
33 encode_time3(__be32 *p, struct timespec *time)
34 {
35 	*p++ = htonl((u32) time->tv_sec); *p++ = htonl(time->tv_nsec);
36 	return p;
37 }
38 
39 static __be32 *
40 decode_time3(__be32 *p, struct timespec *time)
41 {
42 	time->tv_sec = ntohl(*p++);
43 	time->tv_nsec = ntohl(*p++);
44 	return p;
45 }
46 
47 static __be32 *
48 decode_fh(__be32 *p, struct svc_fh *fhp)
49 {
50 	unsigned int size;
51 	fh_init(fhp, NFS3_FHSIZE);
52 	size = ntohl(*p++);
53 	if (size > NFS3_FHSIZE)
54 		return NULL;
55 
56 	memcpy(&fhp->fh_handle.fh_base, p, size);
57 	fhp->fh_handle.fh_size = size;
58 	return p + XDR_QUADLEN(size);
59 }
60 
61 /* Helper function for NFSv3 ACL code */
62 __be32 *nfs3svc_decode_fh(__be32 *p, struct svc_fh *fhp)
63 {
64 	return decode_fh(p, fhp);
65 }
66 
67 static __be32 *
68 encode_fh(__be32 *p, struct svc_fh *fhp)
69 {
70 	unsigned int size = fhp->fh_handle.fh_size;
71 	*p++ = htonl(size);
72 	if (size) p[XDR_QUADLEN(size)-1]=0;
73 	memcpy(p, &fhp->fh_handle.fh_base, size);
74 	return p + XDR_QUADLEN(size);
75 }
76 
77 /*
78  * Decode a file name and make sure that the path contains
79  * no slashes or null bytes.
80  */
81 static __be32 *
82 decode_filename(__be32 *p, char **namp, unsigned int *lenp)
83 {
84 	char		*name;
85 	unsigned int	i;
86 
87 	if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS3_MAXNAMLEN)) != NULL) {
88 		for (i = 0, name = *namp; i < *lenp; i++, name++) {
89 			if (*name == '\0' || *name == '/')
90 				return NULL;
91 		}
92 	}
93 
94 	return p;
95 }
96 
97 static __be32 *
98 decode_sattr3(__be32 *p, struct iattr *iap)
99 {
100 	u32	tmp;
101 
102 	iap->ia_valid = 0;
103 
104 	if (*p++) {
105 		iap->ia_valid |= ATTR_MODE;
106 		iap->ia_mode = ntohl(*p++);
107 	}
108 	if (*p++) {
109 		iap->ia_uid = make_kuid(&init_user_ns, ntohl(*p++));
110 		if (uid_valid(iap->ia_uid))
111 			iap->ia_valid |= ATTR_UID;
112 	}
113 	if (*p++) {
114 		iap->ia_gid = make_kgid(&init_user_ns, ntohl(*p++));
115 		if (gid_valid(iap->ia_gid))
116 			iap->ia_valid |= ATTR_GID;
117 	}
118 	if (*p++) {
119 		u64	newsize;
120 
121 		iap->ia_valid |= ATTR_SIZE;
122 		p = xdr_decode_hyper(p, &newsize);
123 		if (newsize <= NFS_OFFSET_MAX)
124 			iap->ia_size = newsize;
125 		else
126 			iap->ia_size = NFS_OFFSET_MAX;
127 	}
128 	if ((tmp = ntohl(*p++)) == 1) {	/* set to server time */
129 		iap->ia_valid |= ATTR_ATIME;
130 	} else if (tmp == 2) {		/* set to client time */
131 		iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
132 		iap->ia_atime.tv_sec = ntohl(*p++);
133 		iap->ia_atime.tv_nsec = ntohl(*p++);
134 	}
135 	if ((tmp = ntohl(*p++)) == 1) {	/* set to server time */
136 		iap->ia_valid |= ATTR_MTIME;
137 	} else if (tmp == 2) {		/* set to client time */
138 		iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
139 		iap->ia_mtime.tv_sec = ntohl(*p++);
140 		iap->ia_mtime.tv_nsec = ntohl(*p++);
141 	}
142 	return p;
143 }
144 
145 static __be32 *encode_fsid(__be32 *p, struct svc_fh *fhp)
146 {
147 	u64 f;
148 	switch(fsid_source(fhp)) {
149 	default:
150 	case FSIDSOURCE_DEV:
151 		p = xdr_encode_hyper(p, (u64)huge_encode_dev
152 				     (fhp->fh_dentry->d_inode->i_sb->s_dev));
153 		break;
154 	case FSIDSOURCE_FSID:
155 		p = xdr_encode_hyper(p, (u64) fhp->fh_export->ex_fsid);
156 		break;
157 	case FSIDSOURCE_UUID:
158 		f = ((u64*)fhp->fh_export->ex_uuid)[0];
159 		f ^= ((u64*)fhp->fh_export->ex_uuid)[1];
160 		p = xdr_encode_hyper(p, f);
161 		break;
162 	}
163 	return p;
164 }
165 
166 static __be32 *
167 encode_fattr3(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
168 	      struct kstat *stat)
169 {
170 	*p++ = htonl(nfs3_ftypes[(stat->mode & S_IFMT) >> 12]);
171 	*p++ = htonl((u32) (stat->mode & S_IALLUGO));
172 	*p++ = htonl((u32) stat->nlink);
173 	*p++ = htonl((u32) from_kuid(&init_user_ns, stat->uid));
174 	*p++ = htonl((u32) from_kgid(&init_user_ns, stat->gid));
175 	if (S_ISLNK(stat->mode) && stat->size > NFS3_MAXPATHLEN) {
176 		p = xdr_encode_hyper(p, (u64) NFS3_MAXPATHLEN);
177 	} else {
178 		p = xdr_encode_hyper(p, (u64) stat->size);
179 	}
180 	p = xdr_encode_hyper(p, ((u64)stat->blocks) << 9);
181 	*p++ = htonl((u32) MAJOR(stat->rdev));
182 	*p++ = htonl((u32) MINOR(stat->rdev));
183 	p = encode_fsid(p, fhp);
184 	p = xdr_encode_hyper(p, stat->ino);
185 	p = encode_time3(p, &stat->atime);
186 	p = encode_time3(p, &stat->mtime);
187 	p = encode_time3(p, &stat->ctime);
188 
189 	return p;
190 }
191 
192 static __be32 *
193 encode_saved_post_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
194 {
195 	/* Attributes to follow */
196 	*p++ = xdr_one;
197 	return encode_fattr3(rqstp, p, fhp, &fhp->fh_post_attr);
198 }
199 
200 /*
201  * Encode post-operation attributes.
202  * The inode may be NULL if the call failed because of a stale file
203  * handle. In this case, no attributes are returned.
204  */
205 static __be32 *
206 encode_post_op_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
207 {
208 	struct dentry *dentry = fhp->fh_dentry;
209 	if (dentry && dentry->d_inode) {
210 	        __be32 err;
211 		struct kstat stat;
212 
213 		err = fh_getattr(fhp, &stat);
214 		if (!err) {
215 			*p++ = xdr_one;		/* attributes follow */
216 			lease_get_mtime(dentry->d_inode, &stat.mtime);
217 			return encode_fattr3(rqstp, p, fhp, &stat);
218 		}
219 	}
220 	*p++ = xdr_zero;
221 	return p;
222 }
223 
224 /* Helper for NFSv3 ACLs */
225 __be32 *
226 nfs3svc_encode_post_op_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
227 {
228 	return encode_post_op_attr(rqstp, p, fhp);
229 }
230 
231 /*
232  * Enocde weak cache consistency data
233  */
234 static __be32 *
235 encode_wcc_data(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
236 {
237 	struct dentry	*dentry = fhp->fh_dentry;
238 
239 	if (dentry && dentry->d_inode && fhp->fh_post_saved) {
240 		if (fhp->fh_pre_saved) {
241 			*p++ = xdr_one;
242 			p = xdr_encode_hyper(p, (u64) fhp->fh_pre_size);
243 			p = encode_time3(p, &fhp->fh_pre_mtime);
244 			p = encode_time3(p, &fhp->fh_pre_ctime);
245 		} else {
246 			*p++ = xdr_zero;
247 		}
248 		return encode_saved_post_attr(rqstp, p, fhp);
249 	}
250 	/* no pre- or post-attrs */
251 	*p++ = xdr_zero;
252 	return encode_post_op_attr(rqstp, p, fhp);
253 }
254 
255 /*
256  * Fill in the post_op attr for the wcc data
257  */
258 void fill_post_wcc(struct svc_fh *fhp)
259 {
260 	__be32 err;
261 
262 	if (fhp->fh_post_saved)
263 		printk("nfsd: inode locked twice during operation.\n");
264 
265 	err = fh_getattr(fhp, &fhp->fh_post_attr);
266 	fhp->fh_post_change = fhp->fh_dentry->d_inode->i_version;
267 	if (err) {
268 		fhp->fh_post_saved = 0;
269 		/* Grab the ctime anyway - set_change_info might use it */
270 		fhp->fh_post_attr.ctime = fhp->fh_dentry->d_inode->i_ctime;
271 	} else
272 		fhp->fh_post_saved = 1;
273 }
274 
275 /*
276  * XDR decode functions
277  */
278 int
279 nfs3svc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p, struct nfsd_fhandle *args)
280 {
281 	if (!(p = decode_fh(p, &args->fh)))
282 		return 0;
283 	return xdr_argsize_check(rqstp, p);
284 }
285 
286 int
287 nfs3svc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p,
288 					struct nfsd3_sattrargs *args)
289 {
290 	if (!(p = decode_fh(p, &args->fh)))
291 		return 0;
292 	p = decode_sattr3(p, &args->attrs);
293 
294 	if ((args->check_guard = ntohl(*p++)) != 0) {
295 		struct timespec time;
296 		p = decode_time3(p, &time);
297 		args->guardtime = time.tv_sec;
298 	}
299 
300 	return xdr_argsize_check(rqstp, p);
301 }
302 
303 int
304 nfs3svc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p,
305 					struct nfsd3_diropargs *args)
306 {
307 	if (!(p = decode_fh(p, &args->fh))
308 	 || !(p = decode_filename(p, &args->name, &args->len)))
309 		return 0;
310 
311 	return xdr_argsize_check(rqstp, p);
312 }
313 
314 int
315 nfs3svc_decode_accessargs(struct svc_rqst *rqstp, __be32 *p,
316 					struct nfsd3_accessargs *args)
317 {
318 	if (!(p = decode_fh(p, &args->fh)))
319 		return 0;
320 	args->access = ntohl(*p++);
321 
322 	return xdr_argsize_check(rqstp, p);
323 }
324 
325 int
326 nfs3svc_decode_readargs(struct svc_rqst *rqstp, __be32 *p,
327 					struct nfsd3_readargs *args)
328 {
329 	unsigned int len;
330 	int v;
331 	u32 max_blocksize = svc_max_payload(rqstp);
332 
333 	if (!(p = decode_fh(p, &args->fh)))
334 		return 0;
335 	p = xdr_decode_hyper(p, &args->offset);
336 
337 	len = args->count = ntohl(*p++);
338 
339 	if (len > max_blocksize)
340 		len = max_blocksize;
341 
342 	/* set up the kvec */
343 	v=0;
344 	while (len > 0) {
345 		struct page *p = *(rqstp->rq_next_page++);
346 
347 		rqstp->rq_vec[v].iov_base = page_address(p);
348 		rqstp->rq_vec[v].iov_len = len < PAGE_SIZE? len : PAGE_SIZE;
349 		len -= rqstp->rq_vec[v].iov_len;
350 		v++;
351 	}
352 	args->vlen = v;
353 	return xdr_argsize_check(rqstp, p);
354 }
355 
356 int
357 nfs3svc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
358 					struct nfsd3_writeargs *args)
359 {
360 	unsigned int len, v, hdr, dlen;
361 	u32 max_blocksize = svc_max_payload(rqstp);
362 
363 	if (!(p = decode_fh(p, &args->fh)))
364 		return 0;
365 	p = xdr_decode_hyper(p, &args->offset);
366 
367 	args->count = ntohl(*p++);
368 	args->stable = ntohl(*p++);
369 	len = args->len = ntohl(*p++);
370 	/*
371 	 * The count must equal the amount of data passed.
372 	 */
373 	if (args->count != args->len)
374 		return 0;
375 
376 	/*
377 	 * Check to make sure that we got the right number of
378 	 * bytes.
379 	 */
380 	hdr = (void*)p - rqstp->rq_arg.head[0].iov_base;
381 	dlen = rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len
382 		- hdr;
383 	/*
384 	 * Round the length of the data which was specified up to
385 	 * the next multiple of XDR units and then compare that
386 	 * against the length which was actually received.
387 	 * Note that when RPCSEC/GSS (for example) is used, the
388 	 * data buffer can be padded so dlen might be larger
389 	 * than required.  It must never be smaller.
390 	 */
391 	if (dlen < XDR_QUADLEN(len)*4)
392 		return 0;
393 
394 	if (args->count > max_blocksize) {
395 		args->count = max_blocksize;
396 		len = args->len = max_blocksize;
397 	}
398 	rqstp->rq_vec[0].iov_base = (void*)p;
399 	rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr;
400 	v = 0;
401 	while (len > rqstp->rq_vec[v].iov_len) {
402 		len -= rqstp->rq_vec[v].iov_len;
403 		v++;
404 		rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_pages[v]);
405 		rqstp->rq_vec[v].iov_len = PAGE_SIZE;
406 	}
407 	rqstp->rq_vec[v].iov_len = len;
408 	args->vlen = v + 1;
409 	return 1;
410 }
411 
412 int
413 nfs3svc_decode_createargs(struct svc_rqst *rqstp, __be32 *p,
414 					struct nfsd3_createargs *args)
415 {
416 	if (!(p = decode_fh(p, &args->fh))
417 	 || !(p = decode_filename(p, &args->name, &args->len)))
418 		return 0;
419 
420 	switch (args->createmode = ntohl(*p++)) {
421 	case NFS3_CREATE_UNCHECKED:
422 	case NFS3_CREATE_GUARDED:
423 		p = decode_sattr3(p, &args->attrs);
424 		break;
425 	case NFS3_CREATE_EXCLUSIVE:
426 		args->verf = p;
427 		p += 2;
428 		break;
429 	default:
430 		return 0;
431 	}
432 
433 	return xdr_argsize_check(rqstp, p);
434 }
435 int
436 nfs3svc_decode_mkdirargs(struct svc_rqst *rqstp, __be32 *p,
437 					struct nfsd3_createargs *args)
438 {
439 	if (!(p = decode_fh(p, &args->fh)) ||
440 	    !(p = decode_filename(p, &args->name, &args->len)))
441 		return 0;
442 	p = decode_sattr3(p, &args->attrs);
443 
444 	return xdr_argsize_check(rqstp, p);
445 }
446 
447 int
448 nfs3svc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p,
449 					struct nfsd3_symlinkargs *args)
450 {
451 	unsigned int len, avail;
452 	char *old, *new;
453 	struct kvec *vec;
454 
455 	if (!(p = decode_fh(p, &args->ffh)) ||
456 	    !(p = decode_filename(p, &args->fname, &args->flen))
457 		)
458 		return 0;
459 	p = decode_sattr3(p, &args->attrs);
460 
461 	/* now decode the pathname, which might be larger than the first page.
462 	 * As we have to check for nul's anyway, we copy it into a new page
463 	 * This page appears in the rq_res.pages list, but as pages_len is always
464 	 * 0, it won't get in the way
465 	 */
466 	len = ntohl(*p++);
467 	if (len == 0 || len > NFS3_MAXPATHLEN || len >= PAGE_SIZE)
468 		return 0;
469 	args->tname = new = page_address(*(rqstp->rq_next_page++));
470 	args->tlen = len;
471 	/* first copy and check from the first page */
472 	old = (char*)p;
473 	vec = &rqstp->rq_arg.head[0];
474 	avail = vec->iov_len - (old - (char*)vec->iov_base);
475 	while (len && avail && *old) {
476 		*new++ = *old++;
477 		len--;
478 		avail--;
479 	}
480 	/* now copy next page if there is one */
481 	if (len && !avail && rqstp->rq_arg.page_len) {
482 		avail = rqstp->rq_arg.page_len;
483 		if (avail > PAGE_SIZE)
484 			avail = PAGE_SIZE;
485 		old = page_address(rqstp->rq_arg.pages[0]);
486 	}
487 	while (len && avail && *old) {
488 		*new++ = *old++;
489 		len--;
490 		avail--;
491 	}
492 	*new = '\0';
493 	if (len)
494 		return 0;
495 
496 	return 1;
497 }
498 
499 int
500 nfs3svc_decode_mknodargs(struct svc_rqst *rqstp, __be32 *p,
501 					struct nfsd3_mknodargs *args)
502 {
503 	if (!(p = decode_fh(p, &args->fh))
504 	 || !(p = decode_filename(p, &args->name, &args->len)))
505 		return 0;
506 
507 	args->ftype = ntohl(*p++);
508 
509 	if (args->ftype == NF3BLK  || args->ftype == NF3CHR
510 	 || args->ftype == NF3SOCK || args->ftype == NF3FIFO)
511 		p = decode_sattr3(p, &args->attrs);
512 
513 	if (args->ftype == NF3BLK || args->ftype == NF3CHR) {
514 		args->major = ntohl(*p++);
515 		args->minor = ntohl(*p++);
516 	}
517 
518 	return xdr_argsize_check(rqstp, p);
519 }
520 
521 int
522 nfs3svc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p,
523 					struct nfsd3_renameargs *args)
524 {
525 	if (!(p = decode_fh(p, &args->ffh))
526 	 || !(p = decode_filename(p, &args->fname, &args->flen))
527 	 || !(p = decode_fh(p, &args->tfh))
528 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
529 		return 0;
530 
531 	return xdr_argsize_check(rqstp, p);
532 }
533 
534 int
535 nfs3svc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p,
536 					struct nfsd3_readlinkargs *args)
537 {
538 	if (!(p = decode_fh(p, &args->fh)))
539 		return 0;
540 	args->buffer = page_address(*(rqstp->rq_next_page++));
541 
542 	return xdr_argsize_check(rqstp, p);
543 }
544 
545 int
546 nfs3svc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p,
547 					struct nfsd3_linkargs *args)
548 {
549 	if (!(p = decode_fh(p, &args->ffh))
550 	 || !(p = decode_fh(p, &args->tfh))
551 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
552 		return 0;
553 
554 	return xdr_argsize_check(rqstp, p);
555 }
556 
557 int
558 nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p,
559 					struct nfsd3_readdirargs *args)
560 {
561 	if (!(p = decode_fh(p, &args->fh)))
562 		return 0;
563 	p = xdr_decode_hyper(p, &args->cookie);
564 	args->verf   = p; p += 2;
565 	args->dircount = ~0;
566 	args->count  = ntohl(*p++);
567 
568 	if (args->count > PAGE_SIZE)
569 		args->count = PAGE_SIZE;
570 
571 	args->buffer = page_address(*(rqstp->rq_next_page++));
572 
573 	return xdr_argsize_check(rqstp, p);
574 }
575 
576 int
577 nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, __be32 *p,
578 					struct nfsd3_readdirargs *args)
579 {
580 	int len;
581 	u32 max_blocksize = svc_max_payload(rqstp);
582 
583 	if (!(p = decode_fh(p, &args->fh)))
584 		return 0;
585 	p = xdr_decode_hyper(p, &args->cookie);
586 	args->verf     = p; p += 2;
587 	args->dircount = ntohl(*p++);
588 	args->count    = ntohl(*p++);
589 
590 	len = (args->count > max_blocksize) ? max_blocksize :
591 						  args->count;
592 	args->count = len;
593 
594 	while (len > 0) {
595 		struct page *p = *(rqstp->rq_next_page++);
596 		if (!args->buffer)
597 			args->buffer = page_address(p);
598 		len -= PAGE_SIZE;
599 	}
600 
601 	return xdr_argsize_check(rqstp, p);
602 }
603 
604 int
605 nfs3svc_decode_commitargs(struct svc_rqst *rqstp, __be32 *p,
606 					struct nfsd3_commitargs *args)
607 {
608 	if (!(p = decode_fh(p, &args->fh)))
609 		return 0;
610 	p = xdr_decode_hyper(p, &args->offset);
611 	args->count = ntohl(*p++);
612 
613 	return xdr_argsize_check(rqstp, p);
614 }
615 
616 /*
617  * XDR encode functions
618  */
619 /*
620  * There must be an encoding function for void results so svc_process
621  * will work properly.
622  */
623 int
624 nfs3svc_encode_voidres(struct svc_rqst *rqstp, __be32 *p, void *dummy)
625 {
626 	return xdr_ressize_check(rqstp, p);
627 }
628 
629 /* GETATTR */
630 int
631 nfs3svc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p,
632 					struct nfsd3_attrstat *resp)
633 {
634 	if (resp->status == 0) {
635 		lease_get_mtime(resp->fh.fh_dentry->d_inode,
636 				&resp->stat.mtime);
637 		p = encode_fattr3(rqstp, p, &resp->fh, &resp->stat);
638 	}
639 	return xdr_ressize_check(rqstp, p);
640 }
641 
642 /* SETATTR, REMOVE, RMDIR */
643 int
644 nfs3svc_encode_wccstat(struct svc_rqst *rqstp, __be32 *p,
645 					struct nfsd3_attrstat *resp)
646 {
647 	p = encode_wcc_data(rqstp, p, &resp->fh);
648 	return xdr_ressize_check(rqstp, p);
649 }
650 
651 /* LOOKUP */
652 int
653 nfs3svc_encode_diropres(struct svc_rqst *rqstp, __be32 *p,
654 					struct nfsd3_diropres *resp)
655 {
656 	if (resp->status == 0) {
657 		p = encode_fh(p, &resp->fh);
658 		p = encode_post_op_attr(rqstp, p, &resp->fh);
659 	}
660 	p = encode_post_op_attr(rqstp, p, &resp->dirfh);
661 	return xdr_ressize_check(rqstp, p);
662 }
663 
664 /* ACCESS */
665 int
666 nfs3svc_encode_accessres(struct svc_rqst *rqstp, __be32 *p,
667 					struct nfsd3_accessres *resp)
668 {
669 	p = encode_post_op_attr(rqstp, p, &resp->fh);
670 	if (resp->status == 0)
671 		*p++ = htonl(resp->access);
672 	return xdr_ressize_check(rqstp, p);
673 }
674 
675 /* READLINK */
676 int
677 nfs3svc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p,
678 					struct nfsd3_readlinkres *resp)
679 {
680 	p = encode_post_op_attr(rqstp, p, &resp->fh);
681 	if (resp->status == 0) {
682 		*p++ = htonl(resp->len);
683 		xdr_ressize_check(rqstp, p);
684 		rqstp->rq_res.page_len = resp->len;
685 		if (resp->len & 3) {
686 			/* need to pad the tail */
687 			rqstp->rq_res.tail[0].iov_base = p;
688 			*p = 0;
689 			rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
690 		}
691 		return 1;
692 	} else
693 		return xdr_ressize_check(rqstp, p);
694 }
695 
696 /* READ */
697 int
698 nfs3svc_encode_readres(struct svc_rqst *rqstp, __be32 *p,
699 					struct nfsd3_readres *resp)
700 {
701 	p = encode_post_op_attr(rqstp, p, &resp->fh);
702 	if (resp->status == 0) {
703 		*p++ = htonl(resp->count);
704 		*p++ = htonl(resp->eof);
705 		*p++ = htonl(resp->count);	/* xdr opaque count */
706 		xdr_ressize_check(rqstp, p);
707 		/* now update rqstp->rq_res to reflect data as well */
708 		rqstp->rq_res.page_len = resp->count;
709 		if (resp->count & 3) {
710 			/* need to pad the tail */
711 			rqstp->rq_res.tail[0].iov_base = p;
712 			*p = 0;
713 			rqstp->rq_res.tail[0].iov_len = 4 - (resp->count & 3);
714 		}
715 		return 1;
716 	} else
717 		return xdr_ressize_check(rqstp, p);
718 }
719 
720 /* WRITE */
721 int
722 nfs3svc_encode_writeres(struct svc_rqst *rqstp, __be32 *p,
723 					struct nfsd3_writeres *resp)
724 {
725 	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
726 
727 	p = encode_wcc_data(rqstp, p, &resp->fh);
728 	if (resp->status == 0) {
729 		*p++ = htonl(resp->count);
730 		*p++ = htonl(resp->committed);
731 		*p++ = htonl(nn->nfssvc_boot.tv_sec);
732 		*p++ = htonl(nn->nfssvc_boot.tv_usec);
733 	}
734 	return xdr_ressize_check(rqstp, p);
735 }
736 
737 /* CREATE, MKDIR, SYMLINK, MKNOD */
738 int
739 nfs3svc_encode_createres(struct svc_rqst *rqstp, __be32 *p,
740 					struct nfsd3_diropres *resp)
741 {
742 	if (resp->status == 0) {
743 		*p++ = xdr_one;
744 		p = encode_fh(p, &resp->fh);
745 		p = encode_post_op_attr(rqstp, p, &resp->fh);
746 	}
747 	p = encode_wcc_data(rqstp, p, &resp->dirfh);
748 	return xdr_ressize_check(rqstp, p);
749 }
750 
751 /* RENAME */
752 int
753 nfs3svc_encode_renameres(struct svc_rqst *rqstp, __be32 *p,
754 					struct nfsd3_renameres *resp)
755 {
756 	p = encode_wcc_data(rqstp, p, &resp->ffh);
757 	p = encode_wcc_data(rqstp, p, &resp->tfh);
758 	return xdr_ressize_check(rqstp, p);
759 }
760 
761 /* LINK */
762 int
763 nfs3svc_encode_linkres(struct svc_rqst *rqstp, __be32 *p,
764 					struct nfsd3_linkres *resp)
765 {
766 	p = encode_post_op_attr(rqstp, p, &resp->fh);
767 	p = encode_wcc_data(rqstp, p, &resp->tfh);
768 	return xdr_ressize_check(rqstp, p);
769 }
770 
771 /* READDIR */
772 int
773 nfs3svc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p,
774 					struct nfsd3_readdirres *resp)
775 {
776 	p = encode_post_op_attr(rqstp, p, &resp->fh);
777 
778 	if (resp->status == 0) {
779 		/* stupid readdir cookie */
780 		memcpy(p, resp->verf, 8); p += 2;
781 		xdr_ressize_check(rqstp, p);
782 		if (rqstp->rq_res.head[0].iov_len + (2<<2) > PAGE_SIZE)
783 			return 1; /*No room for trailer */
784 		rqstp->rq_res.page_len = (resp->count) << 2;
785 
786 		/* add the 'tail' to the end of the 'head' page - page 0. */
787 		rqstp->rq_res.tail[0].iov_base = p;
788 		*p++ = 0;		/* no more entries */
789 		*p++ = htonl(resp->common.err == nfserr_eof);
790 		rqstp->rq_res.tail[0].iov_len = 2<<2;
791 		return 1;
792 	} else
793 		return xdr_ressize_check(rqstp, p);
794 }
795 
796 static __be32 *
797 encode_entry_baggage(struct nfsd3_readdirres *cd, __be32 *p, const char *name,
798 	     int namlen, u64 ino)
799 {
800 	*p++ = xdr_one;				 /* mark entry present */
801 	p    = xdr_encode_hyper(p, ino);	 /* file id */
802 	p    = xdr_encode_array(p, name, namlen);/* name length & name */
803 
804 	cd->offset = p;				/* remember pointer */
805 	p = xdr_encode_hyper(p, NFS_OFFSET_MAX);/* offset of next entry */
806 
807 	return p;
808 }
809 
810 static __be32
811 compose_entry_fh(struct nfsd3_readdirres *cd, struct svc_fh *fhp,
812 		const char *name, int namlen)
813 {
814 	struct svc_export	*exp;
815 	struct dentry		*dparent, *dchild;
816 	__be32 rv = nfserr_noent;
817 
818 	dparent = cd->fh.fh_dentry;
819 	exp  = cd->fh.fh_export;
820 
821 	if (isdotent(name, namlen)) {
822 		if (namlen == 2) {
823 			dchild = dget_parent(dparent);
824 			/* filesystem root - cannot return filehandle for ".." */
825 			if (dchild == dparent)
826 				goto out;
827 		} else
828 			dchild = dget(dparent);
829 	} else
830 		dchild = lookup_one_len(name, dparent, namlen);
831 	if (IS_ERR(dchild))
832 		return rv;
833 	if (d_mountpoint(dchild))
834 		goto out;
835 	if (!dchild->d_inode)
836 		goto out;
837 	rv = fh_compose(fhp, exp, dchild, &cd->fh);
838 out:
839 	dput(dchild);
840 	return rv;
841 }
842 
843 static __be32 *encode_entryplus_baggage(struct nfsd3_readdirres *cd, __be32 *p, const char *name, int namlen)
844 {
845 	struct svc_fh	*fh = &cd->scratch;
846 	__be32 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 	struct page **	page;
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 (page = cd->rqstp->rq_respages + 1;
921 				page < cd->rqstp->rq_next_page; page++) {
922 		curr_page_addr = page_address(*page);
923 
924 		if (((caddr_t)cd->buffer >= curr_page_addr) &&
925 		    ((caddr_t)cd->buffer <  curr_page_addr + PAGE_SIZE))
926 			break;
927 	}
928 
929 	if ((caddr_t)(cd->buffer + elen) < (curr_page_addr + PAGE_SIZE)) {
930 		/* encode entry in current page */
931 
932 		p = encode_entry_baggage(cd, p, name, namlen, ino);
933 
934 		if (plus)
935 			p = encode_entryplus_baggage(cd, p, name, namlen);
936 		num_entry_words = p - cd->buffer;
937 	} else if (*(page+1) != NULL) {
938 		/* temporarily encode entry into next page, then move back to
939 		 * current and next page in rq_respages[] */
940 		__be32 *p1, *tmp;
941 		int len1, len2;
942 
943 		/* grab next page for temporary storage of entry */
944 		p1 = tmp = page_address(*(page+1));
945 
946 		p1 = encode_entry_baggage(cd, p1, name, namlen, ino);
947 
948 		if (plus)
949 			p1 = encode_entryplus_baggage(cd, p1, name, namlen);
950 
951 		/* determine entry word length and lengths to go in pages */
952 		num_entry_words = p1 - tmp;
953 		len1 = curr_page_addr + PAGE_SIZE - (caddr_t)cd->buffer;
954 		if ((num_entry_words << 2) < len1) {
955 			/* the actual number of words in the entry is less
956 			 * than elen and can still fit in the current page
957 			 */
958 			memmove(p, tmp, num_entry_words << 2);
959 			p += num_entry_words;
960 
961 			/* update offset */
962 			cd->offset = cd->buffer + (cd->offset - tmp);
963 		} else {
964 			unsigned int offset_r = (cd->offset - tmp) << 2;
965 
966 			/* update pointer to offset location.
967 			 * This is a 64bit quantity, so we need to
968 			 * deal with 3 cases:
969 			 *  -	entirely in first page
970 			 *  -	entirely in second page
971 			 *  -	4 bytes in each page
972 			 */
973 			if (offset_r + 8 <= len1) {
974 				cd->offset = p + (cd->offset - tmp);
975 			} else if (offset_r >= len1) {
976 				cd->offset -= len1 >> 2;
977 			} else {
978 				/* sitting on the fence */
979 				BUG_ON(offset_r != len1 - 4);
980 				cd->offset = p + (cd->offset - tmp);
981 				cd->offset1 = tmp;
982 			}
983 
984 			len2 = (num_entry_words << 2) - len1;
985 
986 			/* move from temp page to current and next pages */
987 			memmove(p, tmp, len1);
988 			memmove(tmp, (caddr_t)tmp+len1, len2);
989 
990 			p = tmp + (len2 >> 2);
991 		}
992 	}
993 	else {
994 		cd->common.err = nfserr_toosmall;
995 		return -EINVAL;
996 	}
997 
998 	cd->buflen -= num_entry_words;
999 	cd->buffer = p;
1000 	cd->common.err = nfs_ok;
1001 	return 0;
1002 
1003 }
1004 
1005 int
1006 nfs3svc_encode_entry(void *cd, const char *name,
1007 		     int namlen, loff_t offset, u64 ino, unsigned int d_type)
1008 {
1009 	return encode_entry(cd, name, namlen, offset, ino, d_type, 0);
1010 }
1011 
1012 int
1013 nfs3svc_encode_entry_plus(void *cd, const char *name,
1014 			  int namlen, loff_t offset, u64 ino,
1015 			  unsigned int d_type)
1016 {
1017 	return encode_entry(cd, name, namlen, offset, ino, d_type, 1);
1018 }
1019 
1020 /* FSSTAT */
1021 int
1022 nfs3svc_encode_fsstatres(struct svc_rqst *rqstp, __be32 *p,
1023 					struct nfsd3_fsstatres *resp)
1024 {
1025 	struct kstatfs	*s = &resp->stats;
1026 	u64		bs = s->f_bsize;
1027 
1028 	*p++ = xdr_zero;	/* no post_op_attr */
1029 
1030 	if (resp->status == 0) {
1031 		p = xdr_encode_hyper(p, bs * s->f_blocks);	/* total bytes */
1032 		p = xdr_encode_hyper(p, bs * s->f_bfree);	/* free bytes */
1033 		p = xdr_encode_hyper(p, bs * s->f_bavail);	/* user available bytes */
1034 		p = xdr_encode_hyper(p, s->f_files);	/* total inodes */
1035 		p = xdr_encode_hyper(p, s->f_ffree);	/* free inodes */
1036 		p = xdr_encode_hyper(p, s->f_ffree);	/* user available inodes */
1037 		*p++ = htonl(resp->invarsec);	/* mean unchanged time */
1038 	}
1039 	return xdr_ressize_check(rqstp, p);
1040 }
1041 
1042 /* FSINFO */
1043 int
1044 nfs3svc_encode_fsinfores(struct svc_rqst *rqstp, __be32 *p,
1045 					struct nfsd3_fsinfores *resp)
1046 {
1047 	*p++ = xdr_zero;	/* no post_op_attr */
1048 
1049 	if (resp->status == 0) {
1050 		*p++ = htonl(resp->f_rtmax);
1051 		*p++ = htonl(resp->f_rtpref);
1052 		*p++ = htonl(resp->f_rtmult);
1053 		*p++ = htonl(resp->f_wtmax);
1054 		*p++ = htonl(resp->f_wtpref);
1055 		*p++ = htonl(resp->f_wtmult);
1056 		*p++ = htonl(resp->f_dtpref);
1057 		p = xdr_encode_hyper(p, resp->f_maxfilesize);
1058 		*p++ = xdr_one;
1059 		*p++ = xdr_zero;
1060 		*p++ = htonl(resp->f_properties);
1061 	}
1062 
1063 	return xdr_ressize_check(rqstp, p);
1064 }
1065 
1066 /* PATHCONF */
1067 int
1068 nfs3svc_encode_pathconfres(struct svc_rqst *rqstp, __be32 *p,
1069 					struct nfsd3_pathconfres *resp)
1070 {
1071 	*p++ = xdr_zero;	/* no post_op_attr */
1072 
1073 	if (resp->status == 0) {
1074 		*p++ = htonl(resp->p_link_max);
1075 		*p++ = htonl(resp->p_name_max);
1076 		*p++ = htonl(resp->p_no_trunc);
1077 		*p++ = htonl(resp->p_chown_restricted);
1078 		*p++ = htonl(resp->p_case_insensitive);
1079 		*p++ = htonl(resp->p_case_preserving);
1080 	}
1081 
1082 	return xdr_ressize_check(rqstp, p);
1083 }
1084 
1085 /* COMMIT */
1086 int
1087 nfs3svc_encode_commitres(struct svc_rqst *rqstp, __be32 *p,
1088 					struct nfsd3_commitres *resp)
1089 {
1090 	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
1091 
1092 	p = encode_wcc_data(rqstp, p, &resp->fh);
1093 	/* Write verifier */
1094 	if (resp->status == 0) {
1095 		*p++ = htonl(nn->nfssvc_boot.tv_sec);
1096 		*p++ = htonl(nn->nfssvc_boot.tv_usec);
1097 	}
1098 	return xdr_ressize_check(rqstp, p);
1099 }
1100 
1101 /*
1102  * XDR release functions
1103  */
1104 int
1105 nfs3svc_release_fhandle(struct svc_rqst *rqstp, __be32 *p,
1106 					struct nfsd3_attrstat *resp)
1107 {
1108 	fh_put(&resp->fh);
1109 	return 1;
1110 }
1111 
1112 int
1113 nfs3svc_release_fhandle2(struct svc_rqst *rqstp, __be32 *p,
1114 					struct nfsd3_fhandle_pair *resp)
1115 {
1116 	fh_put(&resp->fh1);
1117 	fh_put(&resp->fh2);
1118 	return 1;
1119 }
1120