xref: /linux/fs/nfsd/nfs3xdr.c (revision 6fdcba32711044c35c0e1b094cbd8f3f0b4472c9)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * XDR support for nfsd/protocol version 3.
4  *
5  * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
6  *
7  * 2003-08-09 Jamie Lokier: Use htonl() for nanoseconds, not htons()!
8  */
9 
10 #include <linux/namei.h>
11 #include <linux/sunrpc/svc_xprt.h>
12 #include "xdr3.h"
13 #include "auth.h"
14 #include "netns.h"
15 #include "vfs.h"
16 
17 #define NFSDDBG_FACILITY		NFSDDBG_XDR
18 
19 
20 /*
21  * Mapping of S_IF* types to NFS file types
22  */
23 static u32	nfs3_ftypes[] = {
24 	NF3NON,  NF3FIFO, NF3CHR, NF3BAD,
25 	NF3DIR,  NF3BAD,  NF3BLK, NF3BAD,
26 	NF3REG,  NF3BAD,  NF3LNK, NF3BAD,
27 	NF3SOCK, NF3BAD,  NF3LNK, NF3BAD,
28 };
29 
30 
31 /*
32  * XDR functions for basic NFS types
33  */
34 static __be32 *
35 encode_time3(__be32 *p, struct timespec *time)
36 {
37 	*p++ = htonl((u32) time->tv_sec); *p++ = htonl(time->tv_nsec);
38 	return p;
39 }
40 
41 static __be32 *
42 decode_time3(__be32 *p, struct timespec *time)
43 {
44 	time->tv_sec = ntohl(*p++);
45 	time->tv_nsec = ntohl(*p++);
46 	return p;
47 }
48 
49 static __be32 *
50 decode_fh(__be32 *p, struct svc_fh *fhp)
51 {
52 	unsigned int size;
53 	fh_init(fhp, NFS3_FHSIZE);
54 	size = ntohl(*p++);
55 	if (size > NFS3_FHSIZE)
56 		return NULL;
57 
58 	memcpy(&fhp->fh_handle.fh_base, p, size);
59 	fhp->fh_handle.fh_size = size;
60 	return p + XDR_QUADLEN(size);
61 }
62 
63 /* Helper function for NFSv3 ACL code */
64 __be32 *nfs3svc_decode_fh(__be32 *p, struct svc_fh *fhp)
65 {
66 	return decode_fh(p, fhp);
67 }
68 
69 static __be32 *
70 encode_fh(__be32 *p, struct svc_fh *fhp)
71 {
72 	unsigned int size = fhp->fh_handle.fh_size;
73 	*p++ = htonl(size);
74 	if (size) p[XDR_QUADLEN(size)-1]=0;
75 	memcpy(p, &fhp->fh_handle.fh_base, size);
76 	return p + XDR_QUADLEN(size);
77 }
78 
79 /*
80  * Decode a file name and make sure that the path contains
81  * no slashes or null bytes.
82  */
83 static __be32 *
84 decode_filename(__be32 *p, char **namp, unsigned int *lenp)
85 {
86 	char		*name;
87 	unsigned int	i;
88 
89 	if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS3_MAXNAMLEN)) != NULL) {
90 		for (i = 0, name = *namp; i < *lenp; i++, name++) {
91 			if (*name == '\0' || *name == '/')
92 				return NULL;
93 		}
94 	}
95 
96 	return p;
97 }
98 
99 static __be32 *
100 decode_sattr3(__be32 *p, struct iattr *iap, struct user_namespace *userns)
101 {
102 	u32	tmp;
103 
104 	iap->ia_valid = 0;
105 
106 	if (*p++) {
107 		iap->ia_valid |= ATTR_MODE;
108 		iap->ia_mode = ntohl(*p++);
109 	}
110 	if (*p++) {
111 		iap->ia_uid = make_kuid(userns, ntohl(*p++));
112 		if (uid_valid(iap->ia_uid))
113 			iap->ia_valid |= ATTR_UID;
114 	}
115 	if (*p++) {
116 		iap->ia_gid = make_kgid(userns, ntohl(*p++));
117 		if (gid_valid(iap->ia_gid))
118 			iap->ia_valid |= ATTR_GID;
119 	}
120 	if (*p++) {
121 		u64	newsize;
122 
123 		iap->ia_valid |= ATTR_SIZE;
124 		p = xdr_decode_hyper(p, &newsize);
125 		iap->ia_size = min_t(u64, newsize, NFS_OFFSET_MAX);
126 	}
127 	if ((tmp = ntohl(*p++)) == 1) {	/* set to server time */
128 		iap->ia_valid |= ATTR_ATIME;
129 	} else if (tmp == 2) {		/* set to client time */
130 		iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
131 		iap->ia_atime.tv_sec = ntohl(*p++);
132 		iap->ia_atime.tv_nsec = ntohl(*p++);
133 	}
134 	if ((tmp = ntohl(*p++)) == 1) {	/* set to server time */
135 		iap->ia_valid |= ATTR_MTIME;
136 	} else if (tmp == 2) {		/* set to client time */
137 		iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
138 		iap->ia_mtime.tv_sec = ntohl(*p++);
139 		iap->ia_mtime.tv_nsec = ntohl(*p++);
140 	}
141 	return p;
142 }
143 
144 static __be32 *encode_fsid(__be32 *p, struct svc_fh *fhp)
145 {
146 	u64 f;
147 	switch(fsid_source(fhp)) {
148 	default:
149 	case FSIDSOURCE_DEV:
150 		p = xdr_encode_hyper(p, (u64)huge_encode_dev
151 				     (fhp->fh_dentry->d_sb->s_dev));
152 		break;
153 	case FSIDSOURCE_FSID:
154 		p = xdr_encode_hyper(p, (u64) fhp->fh_export->ex_fsid);
155 		break;
156 	case FSIDSOURCE_UUID:
157 		f = ((u64*)fhp->fh_export->ex_uuid)[0];
158 		f ^= ((u64*)fhp->fh_export->ex_uuid)[1];
159 		p = xdr_encode_hyper(p, f);
160 		break;
161 	}
162 	return p;
163 }
164 
165 static __be32 *
166 encode_fattr3(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
167 	      struct kstat *stat)
168 {
169 	struct user_namespace *userns = nfsd_user_namespace(rqstp);
170 	struct timespec ts;
171 	*p++ = htonl(nfs3_ftypes[(stat->mode & S_IFMT) >> 12]);
172 	*p++ = htonl((u32) (stat->mode & S_IALLUGO));
173 	*p++ = htonl((u32) stat->nlink);
174 	*p++ = htonl((u32) from_kuid_munged(userns, stat->uid));
175 	*p++ = htonl((u32) from_kgid_munged(userns, stat->gid));
176 	if (S_ISLNK(stat->mode) && stat->size > NFS3_MAXPATHLEN) {
177 		p = xdr_encode_hyper(p, (u64) NFS3_MAXPATHLEN);
178 	} else {
179 		p = xdr_encode_hyper(p, (u64) stat->size);
180 	}
181 	p = xdr_encode_hyper(p, ((u64)stat->blocks) << 9);
182 	*p++ = htonl((u32) MAJOR(stat->rdev));
183 	*p++ = htonl((u32) MINOR(stat->rdev));
184 	p = encode_fsid(p, fhp);
185 	p = xdr_encode_hyper(p, stat->ino);
186 	ts = timespec64_to_timespec(stat->atime);
187 	p = encode_time3(p, &ts);
188 	ts = timespec64_to_timespec(stat->mtime);
189 	p = encode_time3(p, &ts);
190 	ts = timespec64_to_timespec(stat->ctime);
191 	p = encode_time3(p, &ts);
192 
193 	return p;
194 }
195 
196 static __be32 *
197 encode_saved_post_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
198 {
199 	/* Attributes to follow */
200 	*p++ = xdr_one;
201 	return encode_fattr3(rqstp, p, fhp, &fhp->fh_post_attr);
202 }
203 
204 /*
205  * Encode post-operation attributes.
206  * The inode may be NULL if the call failed because of a stale file
207  * handle. In this case, no attributes are returned.
208  */
209 static __be32 *
210 encode_post_op_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
211 {
212 	struct dentry *dentry = fhp->fh_dentry;
213 	if (dentry && d_really_is_positive(dentry)) {
214 	        __be32 err;
215 		struct kstat stat;
216 
217 		err = fh_getattr(fhp, &stat);
218 		if (!err) {
219 			*p++ = xdr_one;		/* attributes follow */
220 			lease_get_mtime(d_inode(dentry), &stat.mtime);
221 			return encode_fattr3(rqstp, p, fhp, &stat);
222 		}
223 	}
224 	*p++ = xdr_zero;
225 	return p;
226 }
227 
228 /* Helper for NFSv3 ACLs */
229 __be32 *
230 nfs3svc_encode_post_op_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
231 {
232 	return encode_post_op_attr(rqstp, p, fhp);
233 }
234 
235 /*
236  * Enocde weak cache consistency data
237  */
238 static __be32 *
239 encode_wcc_data(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
240 {
241 	struct dentry	*dentry = fhp->fh_dentry;
242 
243 	if (dentry && d_really_is_positive(dentry) && fhp->fh_post_saved) {
244 		if (fhp->fh_pre_saved) {
245 			*p++ = xdr_one;
246 			p = xdr_encode_hyper(p, (u64) fhp->fh_pre_size);
247 			p = encode_time3(p, &fhp->fh_pre_mtime);
248 			p = encode_time3(p, &fhp->fh_pre_ctime);
249 		} else {
250 			*p++ = xdr_zero;
251 		}
252 		return encode_saved_post_attr(rqstp, p, fhp);
253 	}
254 	/* no pre- or post-attrs */
255 	*p++ = xdr_zero;
256 	return encode_post_op_attr(rqstp, p, fhp);
257 }
258 
259 /*
260  * Fill in the pre_op attr for the wcc data
261  */
262 void fill_pre_wcc(struct svc_fh *fhp)
263 {
264 	struct inode    *inode;
265 	struct kstat	stat;
266 	__be32 err;
267 
268 	if (fhp->fh_pre_saved)
269 		return;
270 
271 	inode = d_inode(fhp->fh_dentry);
272 	err = fh_getattr(fhp, &stat);
273 	if (err) {
274 		/* Grab the times from inode anyway */
275 		stat.mtime = inode->i_mtime;
276 		stat.ctime = inode->i_ctime;
277 		stat.size  = inode->i_size;
278 	}
279 
280 	fhp->fh_pre_mtime = timespec64_to_timespec(stat.mtime);
281 	fhp->fh_pre_ctime = timespec64_to_timespec(stat.ctime);
282 	fhp->fh_pre_size  = stat.size;
283 	fhp->fh_pre_change = nfsd4_change_attribute(&stat, inode);
284 	fhp->fh_pre_saved = true;
285 }
286 
287 /*
288  * Fill in the post_op attr for the wcc data
289  */
290 void fill_post_wcc(struct svc_fh *fhp)
291 {
292 	__be32 err;
293 
294 	if (fhp->fh_post_saved)
295 		printk("nfsd: inode locked twice during operation.\n");
296 
297 	err = fh_getattr(fhp, &fhp->fh_post_attr);
298 	fhp->fh_post_change = nfsd4_change_attribute(&fhp->fh_post_attr,
299 						     d_inode(fhp->fh_dentry));
300 	if (err) {
301 		fhp->fh_post_saved = false;
302 		/* Grab the ctime anyway - set_change_info might use it */
303 		fhp->fh_post_attr.ctime = d_inode(fhp->fh_dentry)->i_ctime;
304 	} else
305 		fhp->fh_post_saved = true;
306 }
307 
308 /*
309  * XDR decode functions
310  */
311 int
312 nfs3svc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p)
313 {
314 	struct nfsd_fhandle *args = rqstp->rq_argp;
315 
316 	p = decode_fh(p, &args->fh);
317 	if (!p)
318 		return 0;
319 	return xdr_argsize_check(rqstp, p);
320 }
321 
322 int
323 nfs3svc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p)
324 {
325 	struct nfsd3_sattrargs *args = rqstp->rq_argp;
326 
327 	p = decode_fh(p, &args->fh);
328 	if (!p)
329 		return 0;
330 	p = decode_sattr3(p, &args->attrs, nfsd_user_namespace(rqstp));
331 
332 	if ((args->check_guard = ntohl(*p++)) != 0) {
333 		struct timespec time;
334 		p = decode_time3(p, &time);
335 		args->guardtime = time.tv_sec;
336 	}
337 
338 	return xdr_argsize_check(rqstp, p);
339 }
340 
341 int
342 nfs3svc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p)
343 {
344 	struct nfsd3_diropargs *args = rqstp->rq_argp;
345 
346 	if (!(p = decode_fh(p, &args->fh))
347 	 || !(p = decode_filename(p, &args->name, &args->len)))
348 		return 0;
349 
350 	return xdr_argsize_check(rqstp, p);
351 }
352 
353 int
354 nfs3svc_decode_accessargs(struct svc_rqst *rqstp, __be32 *p)
355 {
356 	struct nfsd3_accessargs *args = rqstp->rq_argp;
357 
358 	p = decode_fh(p, &args->fh);
359 	if (!p)
360 		return 0;
361 	args->access = ntohl(*p++);
362 
363 	return xdr_argsize_check(rqstp, p);
364 }
365 
366 int
367 nfs3svc_decode_readargs(struct svc_rqst *rqstp, __be32 *p)
368 {
369 	struct nfsd3_readargs *args = rqstp->rq_argp;
370 	unsigned int len;
371 	int v;
372 	u32 max_blocksize = svc_max_payload(rqstp);
373 
374 	p = decode_fh(p, &args->fh);
375 	if (!p)
376 		return 0;
377 	p = xdr_decode_hyper(p, &args->offset);
378 
379 	args->count = ntohl(*p++);
380 	len = min(args->count, max_blocksize);
381 
382 	/* set up the kvec */
383 	v=0;
384 	while (len > 0) {
385 		struct page *p = *(rqstp->rq_next_page++);
386 
387 		rqstp->rq_vec[v].iov_base = page_address(p);
388 		rqstp->rq_vec[v].iov_len = min_t(unsigned int, len, PAGE_SIZE);
389 		len -= rqstp->rq_vec[v].iov_len;
390 		v++;
391 	}
392 	args->vlen = v;
393 	return xdr_argsize_check(rqstp, p);
394 }
395 
396 int
397 nfs3svc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p)
398 {
399 	struct nfsd3_writeargs *args = rqstp->rq_argp;
400 	unsigned int len, hdr, dlen;
401 	u32 max_blocksize = svc_max_payload(rqstp);
402 	struct kvec *head = rqstp->rq_arg.head;
403 	struct kvec *tail = rqstp->rq_arg.tail;
404 
405 	p = decode_fh(p, &args->fh);
406 	if (!p)
407 		return 0;
408 	p = xdr_decode_hyper(p, &args->offset);
409 
410 	args->count = ntohl(*p++);
411 	args->stable = ntohl(*p++);
412 	len = args->len = ntohl(*p++);
413 	if ((void *)p > head->iov_base + head->iov_len)
414 		return 0;
415 	/*
416 	 * The count must equal the amount of data passed.
417 	 */
418 	if (args->count != args->len)
419 		return 0;
420 
421 	/*
422 	 * Check to make sure that we got the right number of
423 	 * bytes.
424 	 */
425 	hdr = (void*)p - head->iov_base;
426 	dlen = head->iov_len + rqstp->rq_arg.page_len + tail->iov_len - hdr;
427 	/*
428 	 * Round the length of the data which was specified up to
429 	 * the next multiple of XDR units and then compare that
430 	 * against the length which was actually received.
431 	 * Note that when RPCSEC/GSS (for example) is used, the
432 	 * data buffer can be padded so dlen might be larger
433 	 * than required.  It must never be smaller.
434 	 */
435 	if (dlen < XDR_QUADLEN(len)*4)
436 		return 0;
437 
438 	if (args->count > max_blocksize) {
439 		args->count = max_blocksize;
440 		len = args->len = max_blocksize;
441 	}
442 
443 	args->first.iov_base = (void *)p;
444 	args->first.iov_len = head->iov_len - hdr;
445 	return 1;
446 }
447 
448 int
449 nfs3svc_decode_createargs(struct svc_rqst *rqstp, __be32 *p)
450 {
451 	struct nfsd3_createargs *args = rqstp->rq_argp;
452 
453 	if (!(p = decode_fh(p, &args->fh))
454 	 || !(p = decode_filename(p, &args->name, &args->len)))
455 		return 0;
456 
457 	switch (args->createmode = ntohl(*p++)) {
458 	case NFS3_CREATE_UNCHECKED:
459 	case NFS3_CREATE_GUARDED:
460 		p = decode_sattr3(p, &args->attrs, nfsd_user_namespace(rqstp));
461 		break;
462 	case NFS3_CREATE_EXCLUSIVE:
463 		args->verf = p;
464 		p += 2;
465 		break;
466 	default:
467 		return 0;
468 	}
469 
470 	return xdr_argsize_check(rqstp, p);
471 }
472 
473 int
474 nfs3svc_decode_mkdirargs(struct svc_rqst *rqstp, __be32 *p)
475 {
476 	struct nfsd3_createargs *args = rqstp->rq_argp;
477 
478 	if (!(p = decode_fh(p, &args->fh)) ||
479 	    !(p = decode_filename(p, &args->name, &args->len)))
480 		return 0;
481 	p = decode_sattr3(p, &args->attrs, nfsd_user_namespace(rqstp));
482 
483 	return xdr_argsize_check(rqstp, p);
484 }
485 
486 int
487 nfs3svc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p)
488 {
489 	struct nfsd3_symlinkargs *args = rqstp->rq_argp;
490 	char *base = (char *)p;
491 	size_t dlen;
492 
493 	if (!(p = decode_fh(p, &args->ffh)) ||
494 	    !(p = decode_filename(p, &args->fname, &args->flen)))
495 		return 0;
496 	p = decode_sattr3(p, &args->attrs, nfsd_user_namespace(rqstp));
497 
498 	args->tlen = ntohl(*p++);
499 
500 	args->first.iov_base = p;
501 	args->first.iov_len = rqstp->rq_arg.head[0].iov_len;
502 	args->first.iov_len -= (char *)p - base;
503 
504 	dlen = args->first.iov_len + rqstp->rq_arg.page_len +
505 	       rqstp->rq_arg.tail[0].iov_len;
506 	if (dlen < XDR_QUADLEN(args->tlen) << 2)
507 		return 0;
508 	return 1;
509 }
510 
511 int
512 nfs3svc_decode_mknodargs(struct svc_rqst *rqstp, __be32 *p)
513 {
514 	struct nfsd3_mknodargs *args = rqstp->rq_argp;
515 
516 	if (!(p = decode_fh(p, &args->fh))
517 	 || !(p = decode_filename(p, &args->name, &args->len)))
518 		return 0;
519 
520 	args->ftype = ntohl(*p++);
521 
522 	if (args->ftype == NF3BLK  || args->ftype == NF3CHR
523 	 || args->ftype == NF3SOCK || args->ftype == NF3FIFO)
524 		p = decode_sattr3(p, &args->attrs, nfsd_user_namespace(rqstp));
525 
526 	if (args->ftype == NF3BLK || args->ftype == NF3CHR) {
527 		args->major = ntohl(*p++);
528 		args->minor = ntohl(*p++);
529 	}
530 
531 	return xdr_argsize_check(rqstp, p);
532 }
533 
534 int
535 nfs3svc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p)
536 {
537 	struct nfsd3_renameargs *args = rqstp->rq_argp;
538 
539 	if (!(p = decode_fh(p, &args->ffh))
540 	 || !(p = decode_filename(p, &args->fname, &args->flen))
541 	 || !(p = decode_fh(p, &args->tfh))
542 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
543 		return 0;
544 
545 	return xdr_argsize_check(rqstp, p);
546 }
547 
548 int
549 nfs3svc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p)
550 {
551 	struct nfsd3_readlinkargs *args = rqstp->rq_argp;
552 
553 	p = decode_fh(p, &args->fh);
554 	if (!p)
555 		return 0;
556 	args->buffer = page_address(*(rqstp->rq_next_page++));
557 
558 	return xdr_argsize_check(rqstp, p);
559 }
560 
561 int
562 nfs3svc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p)
563 {
564 	struct nfsd3_linkargs *args = rqstp->rq_argp;
565 
566 	if (!(p = decode_fh(p, &args->ffh))
567 	 || !(p = decode_fh(p, &args->tfh))
568 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
569 		return 0;
570 
571 	return xdr_argsize_check(rqstp, p);
572 }
573 
574 int
575 nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p)
576 {
577 	struct nfsd3_readdirargs *args = rqstp->rq_argp;
578 	int len;
579 	u32 max_blocksize = svc_max_payload(rqstp);
580 
581 	p = decode_fh(p, &args->fh);
582 	if (!p)
583 		return 0;
584 	p = xdr_decode_hyper(p, &args->cookie);
585 	args->verf   = p; p += 2;
586 	args->dircount = ~0;
587 	args->count  = ntohl(*p++);
588 	len = args->count  = min_t(u32, args->count, max_blocksize);
589 
590 	while (len > 0) {
591 		struct page *p = *(rqstp->rq_next_page++);
592 		if (!args->buffer)
593 			args->buffer = page_address(p);
594 		len -= PAGE_SIZE;
595 	}
596 
597 	return xdr_argsize_check(rqstp, p);
598 }
599 
600 int
601 nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, __be32 *p)
602 {
603 	struct nfsd3_readdirargs *args = rqstp->rq_argp;
604 	int len;
605 	u32 max_blocksize = svc_max_payload(rqstp);
606 
607 	p = decode_fh(p, &args->fh);
608 	if (!p)
609 		return 0;
610 	p = xdr_decode_hyper(p, &args->cookie);
611 	args->verf     = p; p += 2;
612 	args->dircount = ntohl(*p++);
613 	args->count    = ntohl(*p++);
614 
615 	len = args->count = min(args->count, max_blocksize);
616 	while (len > 0) {
617 		struct page *p = *(rqstp->rq_next_page++);
618 		if (!args->buffer)
619 			args->buffer = page_address(p);
620 		len -= PAGE_SIZE;
621 	}
622 
623 	return xdr_argsize_check(rqstp, p);
624 }
625 
626 int
627 nfs3svc_decode_commitargs(struct svc_rqst *rqstp, __be32 *p)
628 {
629 	struct nfsd3_commitargs *args = rqstp->rq_argp;
630 	p = decode_fh(p, &args->fh);
631 	if (!p)
632 		return 0;
633 	p = xdr_decode_hyper(p, &args->offset);
634 	args->count = ntohl(*p++);
635 
636 	return xdr_argsize_check(rqstp, p);
637 }
638 
639 /*
640  * XDR encode functions
641  */
642 /*
643  * There must be an encoding function for void results so svc_process
644  * will work properly.
645  */
646 int
647 nfs3svc_encode_voidres(struct svc_rqst *rqstp, __be32 *p)
648 {
649 	return xdr_ressize_check(rqstp, p);
650 }
651 
652 /* GETATTR */
653 int
654 nfs3svc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p)
655 {
656 	struct nfsd3_attrstat *resp = rqstp->rq_resp;
657 
658 	if (resp->status == 0) {
659 		lease_get_mtime(d_inode(resp->fh.fh_dentry),
660 				&resp->stat.mtime);
661 		p = encode_fattr3(rqstp, p, &resp->fh, &resp->stat);
662 	}
663 	return xdr_ressize_check(rqstp, p);
664 }
665 
666 /* SETATTR, REMOVE, RMDIR */
667 int
668 nfs3svc_encode_wccstat(struct svc_rqst *rqstp, __be32 *p)
669 {
670 	struct nfsd3_attrstat *resp = rqstp->rq_resp;
671 
672 	p = encode_wcc_data(rqstp, p, &resp->fh);
673 	return xdr_ressize_check(rqstp, p);
674 }
675 
676 /* LOOKUP */
677 int
678 nfs3svc_encode_diropres(struct svc_rqst *rqstp, __be32 *p)
679 {
680 	struct nfsd3_diropres *resp = rqstp->rq_resp;
681 
682 	if (resp->status == 0) {
683 		p = encode_fh(p, &resp->fh);
684 		p = encode_post_op_attr(rqstp, p, &resp->fh);
685 	}
686 	p = encode_post_op_attr(rqstp, p, &resp->dirfh);
687 	return xdr_ressize_check(rqstp, p);
688 }
689 
690 /* ACCESS */
691 int
692 nfs3svc_encode_accessres(struct svc_rqst *rqstp, __be32 *p)
693 {
694 	struct nfsd3_accessres *resp = rqstp->rq_resp;
695 
696 	p = encode_post_op_attr(rqstp, p, &resp->fh);
697 	if (resp->status == 0)
698 		*p++ = htonl(resp->access);
699 	return xdr_ressize_check(rqstp, p);
700 }
701 
702 /* READLINK */
703 int
704 nfs3svc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p)
705 {
706 	struct nfsd3_readlinkres *resp = rqstp->rq_resp;
707 
708 	p = encode_post_op_attr(rqstp, p, &resp->fh);
709 	if (resp->status == 0) {
710 		*p++ = htonl(resp->len);
711 		xdr_ressize_check(rqstp, p);
712 		rqstp->rq_res.page_len = resp->len;
713 		if (resp->len & 3) {
714 			/* need to pad the tail */
715 			rqstp->rq_res.tail[0].iov_base = p;
716 			*p = 0;
717 			rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
718 		}
719 		return 1;
720 	} else
721 		return xdr_ressize_check(rqstp, p);
722 }
723 
724 /* READ */
725 int
726 nfs3svc_encode_readres(struct svc_rqst *rqstp, __be32 *p)
727 {
728 	struct nfsd3_readres *resp = rqstp->rq_resp;
729 
730 	p = encode_post_op_attr(rqstp, p, &resp->fh);
731 	if (resp->status == 0) {
732 		*p++ = htonl(resp->count);
733 		*p++ = htonl(resp->eof);
734 		*p++ = htonl(resp->count);	/* xdr opaque count */
735 		xdr_ressize_check(rqstp, p);
736 		/* now update rqstp->rq_res to reflect data as well */
737 		rqstp->rq_res.page_len = resp->count;
738 		if (resp->count & 3) {
739 			/* need to pad the tail */
740 			rqstp->rq_res.tail[0].iov_base = p;
741 			*p = 0;
742 			rqstp->rq_res.tail[0].iov_len = 4 - (resp->count & 3);
743 		}
744 		return 1;
745 	} else
746 		return xdr_ressize_check(rqstp, p);
747 }
748 
749 /* WRITE */
750 int
751 nfs3svc_encode_writeres(struct svc_rqst *rqstp, __be32 *p)
752 {
753 	struct nfsd3_writeres *resp = rqstp->rq_resp;
754 	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
755 	__be32 verf[2];
756 
757 	p = encode_wcc_data(rqstp, p, &resp->fh);
758 	if (resp->status == 0) {
759 		*p++ = htonl(resp->count);
760 		*p++ = htonl(resp->committed);
761 		/* unique identifier, y2038 overflow can be ignored */
762 		nfsd_copy_boot_verifier(verf, nn);
763 		*p++ = verf[0];
764 		*p++ = verf[1];
765 	}
766 	return xdr_ressize_check(rqstp, p);
767 }
768 
769 /* CREATE, MKDIR, SYMLINK, MKNOD */
770 int
771 nfs3svc_encode_createres(struct svc_rqst *rqstp, __be32 *p)
772 {
773 	struct nfsd3_diropres *resp = rqstp->rq_resp;
774 
775 	if (resp->status == 0) {
776 		*p++ = xdr_one;
777 		p = encode_fh(p, &resp->fh);
778 		p = encode_post_op_attr(rqstp, p, &resp->fh);
779 	}
780 	p = encode_wcc_data(rqstp, p, &resp->dirfh);
781 	return xdr_ressize_check(rqstp, p);
782 }
783 
784 /* RENAME */
785 int
786 nfs3svc_encode_renameres(struct svc_rqst *rqstp, __be32 *p)
787 {
788 	struct nfsd3_renameres *resp = rqstp->rq_resp;
789 
790 	p = encode_wcc_data(rqstp, p, &resp->ffh);
791 	p = encode_wcc_data(rqstp, p, &resp->tfh);
792 	return xdr_ressize_check(rqstp, p);
793 }
794 
795 /* LINK */
796 int
797 nfs3svc_encode_linkres(struct svc_rqst *rqstp, __be32 *p)
798 {
799 	struct nfsd3_linkres *resp = rqstp->rq_resp;
800 
801 	p = encode_post_op_attr(rqstp, p, &resp->fh);
802 	p = encode_wcc_data(rqstp, p, &resp->tfh);
803 	return xdr_ressize_check(rqstp, p);
804 }
805 
806 /* READDIR */
807 int
808 nfs3svc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p)
809 {
810 	struct nfsd3_readdirres *resp = rqstp->rq_resp;
811 
812 	p = encode_post_op_attr(rqstp, p, &resp->fh);
813 
814 	if (resp->status == 0) {
815 		/* stupid readdir cookie */
816 		memcpy(p, resp->verf, 8); p += 2;
817 		xdr_ressize_check(rqstp, p);
818 		if (rqstp->rq_res.head[0].iov_len + (2<<2) > PAGE_SIZE)
819 			return 1; /*No room for trailer */
820 		rqstp->rq_res.page_len = (resp->count) << 2;
821 
822 		/* add the 'tail' to the end of the 'head' page - page 0. */
823 		rqstp->rq_res.tail[0].iov_base = p;
824 		*p++ = 0;		/* no more entries */
825 		*p++ = htonl(resp->common.err == nfserr_eof);
826 		rqstp->rq_res.tail[0].iov_len = 2<<2;
827 		return 1;
828 	} else
829 		return xdr_ressize_check(rqstp, p);
830 }
831 
832 static __be32 *
833 encode_entry_baggage(struct nfsd3_readdirres *cd, __be32 *p, const char *name,
834 	     int namlen, u64 ino)
835 {
836 	*p++ = xdr_one;				 /* mark entry present */
837 	p    = xdr_encode_hyper(p, ino);	 /* file id */
838 	p    = xdr_encode_array(p, name, namlen);/* name length & name */
839 
840 	cd->offset = p;				/* remember pointer */
841 	p = xdr_encode_hyper(p, NFS_OFFSET_MAX);/* offset of next entry */
842 
843 	return p;
844 }
845 
846 static __be32
847 compose_entry_fh(struct nfsd3_readdirres *cd, struct svc_fh *fhp,
848 		 const char *name, int namlen, u64 ino)
849 {
850 	struct svc_export	*exp;
851 	struct dentry		*dparent, *dchild;
852 	__be32 rv = nfserr_noent;
853 
854 	dparent = cd->fh.fh_dentry;
855 	exp  = cd->fh.fh_export;
856 
857 	if (isdotent(name, namlen)) {
858 		if (namlen == 2) {
859 			dchild = dget_parent(dparent);
860 			/* filesystem root - cannot return filehandle for ".." */
861 			if (dchild == dparent)
862 				goto out;
863 		} else
864 			dchild = dget(dparent);
865 	} else
866 		dchild = lookup_positive_unlocked(name, dparent, namlen);
867 	if (IS_ERR(dchild))
868 		return rv;
869 	if (d_mountpoint(dchild))
870 		goto out;
871 	if (dchild->d_inode->i_ino != ino)
872 		goto out;
873 	rv = fh_compose(fhp, exp, dchild, &cd->fh);
874 out:
875 	dput(dchild);
876 	return rv;
877 }
878 
879 static __be32 *encode_entryplus_baggage(struct nfsd3_readdirres *cd, __be32 *p, const char *name, int namlen, u64 ino)
880 {
881 	struct svc_fh	*fh = &cd->scratch;
882 	__be32 err;
883 
884 	fh_init(fh, NFS3_FHSIZE);
885 	err = compose_entry_fh(cd, fh, name, namlen, ino);
886 	if (err) {
887 		*p++ = 0;
888 		*p++ = 0;
889 		goto out;
890 	}
891 	p = encode_post_op_attr(cd->rqstp, p, fh);
892 	*p++ = xdr_one;			/* yes, a file handle follows */
893 	p = encode_fh(p, fh);
894 out:
895 	fh_put(fh);
896 	return p;
897 }
898 
899 /*
900  * Encode a directory entry. This one works for both normal readdir
901  * and readdirplus.
902  * The normal readdir reply requires 2 (fileid) + 1 (stringlen)
903  * + string + 2 (cookie) + 1 (next) words, i.e. 6 + strlen.
904  *
905  * The readdirplus baggage is 1+21 words for post_op_attr, plus the
906  * file handle.
907  */
908 
909 #define NFS3_ENTRY_BAGGAGE	(2 + 1 + 2 + 1)
910 #define NFS3_ENTRYPLUS_BAGGAGE	(1 + 21 + 1 + (NFS3_FHSIZE >> 2))
911 static int
912 encode_entry(struct readdir_cd *ccd, const char *name, int namlen,
913 	     loff_t offset, u64 ino, unsigned int d_type, int plus)
914 {
915 	struct nfsd3_readdirres *cd = container_of(ccd, struct nfsd3_readdirres,
916 		       					common);
917 	__be32		*p = cd->buffer;
918 	caddr_t		curr_page_addr = NULL;
919 	struct page **	page;
920 	int		slen;		/* string (name) length */
921 	int		elen;		/* estimated entry length in words */
922 	int		num_entry_words = 0;	/* actual number of words */
923 
924 	if (cd->offset) {
925 		u64 offset64 = offset;
926 
927 		if (unlikely(cd->offset1)) {
928 			/* we ended up with offset on a page boundary */
929 			*cd->offset = htonl(offset64 >> 32);
930 			*cd->offset1 = htonl(offset64 & 0xffffffff);
931 			cd->offset1 = NULL;
932 		} else {
933 			xdr_encode_hyper(cd->offset, offset64);
934 		}
935 		cd->offset = NULL;
936 	}
937 
938 	/*
939 	dprintk("encode_entry(%.*s @%ld%s)\n",
940 		namlen, name, (long) offset, plus? " plus" : "");
941 	 */
942 
943 	/* truncate filename if too long */
944 	namlen = min(namlen, NFS3_MAXNAMLEN);
945 
946 	slen = XDR_QUADLEN(namlen);
947 	elen = slen + NFS3_ENTRY_BAGGAGE
948 		+ (plus? NFS3_ENTRYPLUS_BAGGAGE : 0);
949 
950 	if (cd->buflen < elen) {
951 		cd->common.err = nfserr_toosmall;
952 		return -EINVAL;
953 	}
954 
955 	/* determine which page in rq_respages[] we are currently filling */
956 	for (page = cd->rqstp->rq_respages + 1;
957 				page < cd->rqstp->rq_next_page; page++) {
958 		curr_page_addr = page_address(*page);
959 
960 		if (((caddr_t)cd->buffer >= curr_page_addr) &&
961 		    ((caddr_t)cd->buffer <  curr_page_addr + PAGE_SIZE))
962 			break;
963 	}
964 
965 	if ((caddr_t)(cd->buffer + elen) < (curr_page_addr + PAGE_SIZE)) {
966 		/* encode entry in current page */
967 
968 		p = encode_entry_baggage(cd, p, name, namlen, ino);
969 
970 		if (plus)
971 			p = encode_entryplus_baggage(cd, p, name, namlen, ino);
972 		num_entry_words = p - cd->buffer;
973 	} else if (*(page+1) != NULL) {
974 		/* temporarily encode entry into next page, then move back to
975 		 * current and next page in rq_respages[] */
976 		__be32 *p1, *tmp;
977 		int len1, len2;
978 
979 		/* grab next page for temporary storage of entry */
980 		p1 = tmp = page_address(*(page+1));
981 
982 		p1 = encode_entry_baggage(cd, p1, name, namlen, ino);
983 
984 		if (plus)
985 			p1 = encode_entryplus_baggage(cd, p1, name, namlen, ino);
986 
987 		/* determine entry word length and lengths to go in pages */
988 		num_entry_words = p1 - tmp;
989 		len1 = curr_page_addr + PAGE_SIZE - (caddr_t)cd->buffer;
990 		if ((num_entry_words << 2) < len1) {
991 			/* the actual number of words in the entry is less
992 			 * than elen and can still fit in the current page
993 			 */
994 			memmove(p, tmp, num_entry_words << 2);
995 			p += num_entry_words;
996 
997 			/* update offset */
998 			cd->offset = cd->buffer + (cd->offset - tmp);
999 		} else {
1000 			unsigned int offset_r = (cd->offset - tmp) << 2;
1001 
1002 			/* update pointer to offset location.
1003 			 * This is a 64bit quantity, so we need to
1004 			 * deal with 3 cases:
1005 			 *  -	entirely in first page
1006 			 *  -	entirely in second page
1007 			 *  -	4 bytes in each page
1008 			 */
1009 			if (offset_r + 8 <= len1) {
1010 				cd->offset = p + (cd->offset - tmp);
1011 			} else if (offset_r >= len1) {
1012 				cd->offset -= len1 >> 2;
1013 			} else {
1014 				/* sitting on the fence */
1015 				BUG_ON(offset_r != len1 - 4);
1016 				cd->offset = p + (cd->offset - tmp);
1017 				cd->offset1 = tmp;
1018 			}
1019 
1020 			len2 = (num_entry_words << 2) - len1;
1021 
1022 			/* move from temp page to current and next pages */
1023 			memmove(p, tmp, len1);
1024 			memmove(tmp, (caddr_t)tmp+len1, len2);
1025 
1026 			p = tmp + (len2 >> 2);
1027 		}
1028 	}
1029 	else {
1030 		cd->common.err = nfserr_toosmall;
1031 		return -EINVAL;
1032 	}
1033 
1034 	cd->buflen -= num_entry_words;
1035 	cd->buffer = p;
1036 	cd->common.err = nfs_ok;
1037 	return 0;
1038 
1039 }
1040 
1041 int
1042 nfs3svc_encode_entry(void *cd, const char *name,
1043 		     int namlen, loff_t offset, u64 ino, unsigned int d_type)
1044 {
1045 	return encode_entry(cd, name, namlen, offset, ino, d_type, 0);
1046 }
1047 
1048 int
1049 nfs3svc_encode_entry_plus(void *cd, const char *name,
1050 			  int namlen, loff_t offset, u64 ino,
1051 			  unsigned int d_type)
1052 {
1053 	return encode_entry(cd, name, namlen, offset, ino, d_type, 1);
1054 }
1055 
1056 /* FSSTAT */
1057 int
1058 nfs3svc_encode_fsstatres(struct svc_rqst *rqstp, __be32 *p)
1059 {
1060 	struct nfsd3_fsstatres *resp = rqstp->rq_resp;
1061 	struct kstatfs	*s = &resp->stats;
1062 	u64		bs = s->f_bsize;
1063 
1064 	*p++ = xdr_zero;	/* no post_op_attr */
1065 
1066 	if (resp->status == 0) {
1067 		p = xdr_encode_hyper(p, bs * s->f_blocks);	/* total bytes */
1068 		p = xdr_encode_hyper(p, bs * s->f_bfree);	/* free bytes */
1069 		p = xdr_encode_hyper(p, bs * s->f_bavail);	/* user available bytes */
1070 		p = xdr_encode_hyper(p, s->f_files);	/* total inodes */
1071 		p = xdr_encode_hyper(p, s->f_ffree);	/* free inodes */
1072 		p = xdr_encode_hyper(p, s->f_ffree);	/* user available inodes */
1073 		*p++ = htonl(resp->invarsec);	/* mean unchanged time */
1074 	}
1075 	return xdr_ressize_check(rqstp, p);
1076 }
1077 
1078 /* FSINFO */
1079 int
1080 nfs3svc_encode_fsinfores(struct svc_rqst *rqstp, __be32 *p)
1081 {
1082 	struct nfsd3_fsinfores *resp = rqstp->rq_resp;
1083 
1084 	*p++ = xdr_zero;	/* no post_op_attr */
1085 
1086 	if (resp->status == 0) {
1087 		*p++ = htonl(resp->f_rtmax);
1088 		*p++ = htonl(resp->f_rtpref);
1089 		*p++ = htonl(resp->f_rtmult);
1090 		*p++ = htonl(resp->f_wtmax);
1091 		*p++ = htonl(resp->f_wtpref);
1092 		*p++ = htonl(resp->f_wtmult);
1093 		*p++ = htonl(resp->f_dtpref);
1094 		p = xdr_encode_hyper(p, resp->f_maxfilesize);
1095 		*p++ = xdr_one;
1096 		*p++ = xdr_zero;
1097 		*p++ = htonl(resp->f_properties);
1098 	}
1099 
1100 	return xdr_ressize_check(rqstp, p);
1101 }
1102 
1103 /* PATHCONF */
1104 int
1105 nfs3svc_encode_pathconfres(struct svc_rqst *rqstp, __be32 *p)
1106 {
1107 	struct nfsd3_pathconfres *resp = rqstp->rq_resp;
1108 
1109 	*p++ = xdr_zero;	/* no post_op_attr */
1110 
1111 	if (resp->status == 0) {
1112 		*p++ = htonl(resp->p_link_max);
1113 		*p++ = htonl(resp->p_name_max);
1114 		*p++ = htonl(resp->p_no_trunc);
1115 		*p++ = htonl(resp->p_chown_restricted);
1116 		*p++ = htonl(resp->p_case_insensitive);
1117 		*p++ = htonl(resp->p_case_preserving);
1118 	}
1119 
1120 	return xdr_ressize_check(rqstp, p);
1121 }
1122 
1123 /* COMMIT */
1124 int
1125 nfs3svc_encode_commitres(struct svc_rqst *rqstp, __be32 *p)
1126 {
1127 	struct nfsd3_commitres *resp = rqstp->rq_resp;
1128 	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
1129 	__be32 verf[2];
1130 
1131 	p = encode_wcc_data(rqstp, p, &resp->fh);
1132 	/* Write verifier */
1133 	if (resp->status == 0) {
1134 		/* unique identifier, y2038 overflow can be ignored */
1135 		nfsd_copy_boot_verifier(verf, nn);
1136 		*p++ = verf[0];
1137 		*p++ = verf[1];
1138 	}
1139 	return xdr_ressize_check(rqstp, p);
1140 }
1141 
1142 /*
1143  * XDR release functions
1144  */
1145 void
1146 nfs3svc_release_fhandle(struct svc_rqst *rqstp)
1147 {
1148 	struct nfsd3_attrstat *resp = rqstp->rq_resp;
1149 
1150 	fh_put(&resp->fh);
1151 }
1152 
1153 void
1154 nfs3svc_release_fhandle2(struct svc_rqst *rqstp)
1155 {
1156 	struct nfsd3_fhandle_pair *resp = rqstp->rq_resp;
1157 
1158 	fh_put(&resp->fh1);
1159 	fh_put(&resp->fh2);
1160 }
1161