xref: /linux/fs/nfsd/nfs3xdr.c (revision 42fda66387daa53538ae13a2c858396aaf037158)
1 /*
2  * linux/fs/nfsd/nfs3xdr.c
3  *
4  * XDR support for nfsd/protocol version 3.
5  *
6  * Copyright (C) 1995, 1996, 1997 Olaf Kirch <okir@monad.swb.de>
7  *
8  * 2003-08-09 Jamie Lokier: Use htonl() for nanoseconds, not htons()!
9  */
10 
11 #include <linux/types.h>
12 #include <linux/time.h>
13 #include <linux/nfs3.h>
14 #include <linux/list.h>
15 #include <linux/spinlock.h>
16 #include <linux/dcache.h>
17 #include <linux/namei.h>
18 #include <linux/mm.h>
19 #include <linux/vfs.h>
20 #include <linux/sunrpc/xdr.h>
21 #include <linux/sunrpc/svc.h>
22 #include <linux/nfsd/nfsd.h>
23 #include <linux/nfsd/xdr3.h>
24 
25 #define NFSDDBG_FACILITY		NFSDDBG_XDR
26 
27 
28 /*
29  * Mapping of S_IF* types to NFS file types
30  */
31 static u32	nfs3_ftypes[] = {
32 	NF3NON,  NF3FIFO, NF3CHR, NF3BAD,
33 	NF3DIR,  NF3BAD,  NF3BLK, NF3BAD,
34 	NF3REG,  NF3BAD,  NF3LNK, NF3BAD,
35 	NF3SOCK, NF3BAD,  NF3LNK, NF3BAD,
36 };
37 
38 /*
39  * XDR functions for basic NFS types
40  */
41 static __be32 *
42 encode_time3(__be32 *p, struct timespec *time)
43 {
44 	*p++ = htonl((u32) time->tv_sec); *p++ = htonl(time->tv_nsec);
45 	return p;
46 }
47 
48 static __be32 *
49 decode_time3(__be32 *p, struct timespec *time)
50 {
51 	time->tv_sec = ntohl(*p++);
52 	time->tv_nsec = ntohl(*p++);
53 	return p;
54 }
55 
56 static __be32 *
57 decode_fh(__be32 *p, struct svc_fh *fhp)
58 {
59 	unsigned int size;
60 	fh_init(fhp, NFS3_FHSIZE);
61 	size = ntohl(*p++);
62 	if (size > NFS3_FHSIZE)
63 		return NULL;
64 
65 	memcpy(&fhp->fh_handle.fh_base, p, size);
66 	fhp->fh_handle.fh_size = size;
67 	return p + XDR_QUADLEN(size);
68 }
69 
70 /* Helper function for NFSv3 ACL code */
71 __be32 *nfs3svc_decode_fh(__be32 *p, struct svc_fh *fhp)
72 {
73 	return decode_fh(p, fhp);
74 }
75 
76 static __be32 *
77 encode_fh(__be32 *p, struct svc_fh *fhp)
78 {
79 	unsigned int size = fhp->fh_handle.fh_size;
80 	*p++ = htonl(size);
81 	if (size) p[XDR_QUADLEN(size)-1]=0;
82 	memcpy(p, &fhp->fh_handle.fh_base, size);
83 	return p + XDR_QUADLEN(size);
84 }
85 
86 /*
87  * Decode a file name and make sure that the path contains
88  * no slashes or null bytes.
89  */
90 static __be32 *
91 decode_filename(__be32 *p, char **namp, int *lenp)
92 {
93 	char		*name;
94 	int		i;
95 
96 	if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS3_MAXNAMLEN)) != NULL) {
97 		for (i = 0, name = *namp; i < *lenp; i++, name++) {
98 			if (*name == '\0' || *name == '/')
99 				return NULL;
100 		}
101 	}
102 
103 	return p;
104 }
105 
106 static __be32 *
107 decode_sattr3(__be32 *p, struct iattr *iap)
108 {
109 	u32	tmp;
110 
111 	iap->ia_valid = 0;
112 
113 	if (*p++) {
114 		iap->ia_valid |= ATTR_MODE;
115 		iap->ia_mode = ntohl(*p++);
116 	}
117 	if (*p++) {
118 		iap->ia_valid |= ATTR_UID;
119 		iap->ia_uid = ntohl(*p++);
120 	}
121 	if (*p++) {
122 		iap->ia_valid |= ATTR_GID;
123 		iap->ia_gid = ntohl(*p++);
124 	}
125 	if (*p++) {
126 		u64	newsize;
127 
128 		iap->ia_valid |= ATTR_SIZE;
129 		p = xdr_decode_hyper(p, &newsize);
130 		if (newsize <= NFS_OFFSET_MAX)
131 			iap->ia_size = newsize;
132 		else
133 			iap->ia_size = NFS_OFFSET_MAX;
134 	}
135 	if ((tmp = ntohl(*p++)) == 1) {	/* set to server time */
136 		iap->ia_valid |= ATTR_ATIME;
137 	} else if (tmp == 2) {		/* set to client time */
138 		iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
139 		iap->ia_atime.tv_sec = ntohl(*p++);
140 		iap->ia_atime.tv_nsec = ntohl(*p++);
141 	}
142 	if ((tmp = ntohl(*p++)) == 1) {	/* set to server time */
143 		iap->ia_valid |= ATTR_MTIME;
144 	} else if (tmp == 2) {		/* set to client time */
145 		iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
146 		iap->ia_mtime.tv_sec = ntohl(*p++);
147 		iap->ia_mtime.tv_nsec = ntohl(*p++);
148 	}
149 	return p;
150 }
151 
152 static __be32 *encode_fsid(__be32 *p, struct svc_fh *fhp)
153 {
154 	u64 f;
155 	switch(fsid_source(fhp)) {
156 	default:
157 	case FSIDSOURCE_DEV:
158 		p = xdr_encode_hyper(p, (u64)huge_encode_dev
159 				     (fhp->fh_dentry->d_inode->i_sb->s_dev));
160 		break;
161 	case FSIDSOURCE_FSID:
162 		p = xdr_encode_hyper(p, (u64) fhp->fh_export->ex_fsid);
163 		break;
164 	case FSIDSOURCE_UUID:
165 		f = ((u64*)fhp->fh_export->ex_uuid)[0];
166 		f ^= ((u64*)fhp->fh_export->ex_uuid)[1];
167 		p = xdr_encode_hyper(p, f);
168 		break;
169 	}
170 	return p;
171 }
172 
173 static __be32 *
174 encode_fattr3(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
175 	      struct kstat *stat)
176 {
177 	*p++ = htonl(nfs3_ftypes[(stat->mode & S_IFMT) >> 12]);
178 	*p++ = htonl((u32) stat->mode);
179 	*p++ = htonl((u32) stat->nlink);
180 	*p++ = htonl((u32) nfsd_ruid(rqstp, stat->uid));
181 	*p++ = htonl((u32) nfsd_rgid(rqstp, stat->gid));
182 	if (S_ISLNK(stat->mode) && stat->size > NFS3_MAXPATHLEN) {
183 		p = xdr_encode_hyper(p, (u64) NFS3_MAXPATHLEN);
184 	} else {
185 		p = xdr_encode_hyper(p, (u64) stat->size);
186 	}
187 	p = xdr_encode_hyper(p, ((u64)stat->blocks) << 9);
188 	*p++ = htonl((u32) MAJOR(stat->rdev));
189 	*p++ = htonl((u32) MINOR(stat->rdev));
190 	p = encode_fsid(p, fhp);
191 	p = xdr_encode_hyper(p, stat->ino);
192 	p = encode_time3(p, &stat->atime);
193 	p = encode_time3(p, &stat->mtime);
194 	p = encode_time3(p, &stat->ctime);
195 
196 	return p;
197 }
198 
199 static __be32 *
200 encode_saved_post_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
201 {
202 	/* Attributes to follow */
203 	*p++ = xdr_one;
204 	return encode_fattr3(rqstp, p, fhp, &fhp->fh_post_attr);
205 }
206 
207 /*
208  * Encode post-operation attributes.
209  * The inode may be NULL if the call failed because of a stale file
210  * handle. In this case, no attributes are returned.
211  */
212 static __be32 *
213 encode_post_op_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
214 {
215 	struct dentry *dentry = fhp->fh_dentry;
216 	if (dentry && dentry->d_inode) {
217 	        int err;
218 		struct kstat stat;
219 
220 		err = vfs_getattr(fhp->fh_export->ex_mnt, dentry, &stat);
221 		if (!err) {
222 			*p++ = xdr_one;		/* attributes follow */
223 			lease_get_mtime(dentry->d_inode, &stat.mtime);
224 			return encode_fattr3(rqstp, p, fhp, &stat);
225 		}
226 	}
227 	*p++ = xdr_zero;
228 	return p;
229 }
230 
231 /* Helper for NFSv3 ACLs */
232 __be32 *
233 nfs3svc_encode_post_op_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
234 {
235 	return encode_post_op_attr(rqstp, p, fhp);
236 }
237 
238 /*
239  * Enocde weak cache consistency data
240  */
241 static __be32 *
242 encode_wcc_data(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
243 {
244 	struct dentry	*dentry = fhp->fh_dentry;
245 
246 	if (dentry && dentry->d_inode && fhp->fh_post_saved) {
247 		if (fhp->fh_pre_saved) {
248 			*p++ = xdr_one;
249 			p = xdr_encode_hyper(p, (u64) fhp->fh_pre_size);
250 			p = encode_time3(p, &fhp->fh_pre_mtime);
251 			p = encode_time3(p, &fhp->fh_pre_ctime);
252 		} else {
253 			*p++ = xdr_zero;
254 		}
255 		return encode_saved_post_attr(rqstp, p, fhp);
256 	}
257 	/* no pre- or post-attrs */
258 	*p++ = xdr_zero;
259 	return encode_post_op_attr(rqstp, p, fhp);
260 }
261 
262 /*
263  * Fill in the post_op attr for the wcc data
264  */
265 void fill_post_wcc(struct svc_fh *fhp)
266 {
267 	int err;
268 
269 	if (fhp->fh_post_saved)
270 		printk("nfsd: inode locked twice during operation.\n");
271 
272 	err = vfs_getattr(fhp->fh_export->ex_mnt, fhp->fh_dentry,
273 			&fhp->fh_post_attr);
274 	if (err)
275 		fhp->fh_post_saved = 0;
276 	else
277 		fhp->fh_post_saved = 1;
278 }
279 
280 /*
281  * XDR decode functions
282  */
283 int
284 nfs3svc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p, struct nfsd_fhandle *args)
285 {
286 	if (!(p = decode_fh(p, &args->fh)))
287 		return 0;
288 	return xdr_argsize_check(rqstp, p);
289 }
290 
291 int
292 nfs3svc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p,
293 					struct nfsd3_sattrargs *args)
294 {
295 	if (!(p = decode_fh(p, &args->fh)))
296 		return 0;
297 	p = decode_sattr3(p, &args->attrs);
298 
299 	if ((args->check_guard = ntohl(*p++)) != 0) {
300 		struct timespec time;
301 		p = decode_time3(p, &time);
302 		args->guardtime = time.tv_sec;
303 	}
304 
305 	return xdr_argsize_check(rqstp, p);
306 }
307 
308 int
309 nfs3svc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p,
310 					struct nfsd3_diropargs *args)
311 {
312 	if (!(p = decode_fh(p, &args->fh))
313 	 || !(p = decode_filename(p, &args->name, &args->len)))
314 		return 0;
315 
316 	return xdr_argsize_check(rqstp, p);
317 }
318 
319 int
320 nfs3svc_decode_accessargs(struct svc_rqst *rqstp, __be32 *p,
321 					struct nfsd3_accessargs *args)
322 {
323 	if (!(p = decode_fh(p, &args->fh)))
324 		return 0;
325 	args->access = ntohl(*p++);
326 
327 	return xdr_argsize_check(rqstp, p);
328 }
329 
330 int
331 nfs3svc_decode_readargs(struct svc_rqst *rqstp, __be32 *p,
332 					struct nfsd3_readargs *args)
333 {
334 	unsigned int len;
335 	int v,pn;
336 	u32 max_blocksize = svc_max_payload(rqstp);
337 
338 	if (!(p = decode_fh(p, &args->fh)))
339 		return 0;
340 	p = xdr_decode_hyper(p, &args->offset);
341 
342 	len = args->count = ntohl(*p++);
343 
344 	if (len > max_blocksize)
345 		len = max_blocksize;
346 
347 	/* set up the kvec */
348 	v=0;
349 	while (len > 0) {
350 		pn = rqstp->rq_resused++;
351 		rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_respages[pn]);
352 		rqstp->rq_vec[v].iov_len = len < PAGE_SIZE? len : PAGE_SIZE;
353 		len -= rqstp->rq_vec[v].iov_len;
354 		v++;
355 	}
356 	args->vlen = v;
357 	return xdr_argsize_check(rqstp, p);
358 }
359 
360 int
361 nfs3svc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
362 					struct nfsd3_writeargs *args)
363 {
364 	unsigned int len, v, hdr, dlen;
365 	u32 max_blocksize = svc_max_payload(rqstp);
366 
367 	if (!(p = decode_fh(p, &args->fh)))
368 		return 0;
369 	p = xdr_decode_hyper(p, &args->offset);
370 
371 	args->count = ntohl(*p++);
372 	args->stable = ntohl(*p++);
373 	len = args->len = ntohl(*p++);
374 	/*
375 	 * The count must equal the amount of data passed.
376 	 */
377 	if (args->count != args->len)
378 		return 0;
379 
380 	/*
381 	 * Check to make sure that we got the right number of
382 	 * bytes.
383 	 */
384 	hdr = (void*)p - rqstp->rq_arg.head[0].iov_base;
385 	dlen = rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len
386 		- hdr;
387 	/*
388 	 * Round the length of the data which was specified up to
389 	 * the next multiple of XDR units and then compare that
390 	 * against the length which was actually received.
391 	 */
392 	if (dlen != XDR_QUADLEN(len)*4)
393 		return 0;
394 
395 	if (args->count > max_blocksize) {
396 		args->count = max_blocksize;
397 		len = args->len = max_blocksize;
398 	}
399 	rqstp->rq_vec[0].iov_base = (void*)p;
400 	rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr;
401 	v = 0;
402 	while (len > rqstp->rq_vec[v].iov_len) {
403 		len -= rqstp->rq_vec[v].iov_len;
404 		v++;
405 		rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_pages[v]);
406 		rqstp->rq_vec[v].iov_len = PAGE_SIZE;
407 	}
408 	rqstp->rq_vec[v].iov_len = len;
409 	args->vlen = v + 1;
410 	return 1;
411 }
412 
413 int
414 nfs3svc_decode_createargs(struct svc_rqst *rqstp, __be32 *p,
415 					struct nfsd3_createargs *args)
416 {
417 	if (!(p = decode_fh(p, &args->fh))
418 	 || !(p = decode_filename(p, &args->name, &args->len)))
419 		return 0;
420 
421 	switch (args->createmode = ntohl(*p++)) {
422 	case NFS3_CREATE_UNCHECKED:
423 	case NFS3_CREATE_GUARDED:
424 		p = decode_sattr3(p, &args->attrs);
425 		break;
426 	case NFS3_CREATE_EXCLUSIVE:
427 		args->verf = p;
428 		p += 2;
429 		break;
430 	default:
431 		return 0;
432 	}
433 
434 	return xdr_argsize_check(rqstp, p);
435 }
436 int
437 nfs3svc_decode_mkdirargs(struct svc_rqst *rqstp, __be32 *p,
438 					struct nfsd3_createargs *args)
439 {
440 	if (!(p = decode_fh(p, &args->fh)) ||
441 	    !(p = decode_filename(p, &args->name, &args->len)))
442 		return 0;
443 	p = decode_sattr3(p, &args->attrs);
444 
445 	return xdr_argsize_check(rqstp, p);
446 }
447 
448 int
449 nfs3svc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p,
450 					struct nfsd3_symlinkargs *args)
451 {
452 	unsigned int len;
453 	int avail;
454 	char *old, *new;
455 	struct kvec *vec;
456 
457 	if (!(p = decode_fh(p, &args->ffh)) ||
458 	    !(p = decode_filename(p, &args->fname, &args->flen))
459 		)
460 		return 0;
461 	p = decode_sattr3(p, &args->attrs);
462 
463 	/* now decode the pathname, which might be larger than the first page.
464 	 * As we have to check for nul's anyway, we copy it into a new page
465 	 * This page appears in the rq_res.pages list, but as pages_len is always
466 	 * 0, it won't get in the way
467 	 */
468 	len = ntohl(*p++);
469 	if (len == 0 || len > NFS3_MAXPATHLEN || len >= PAGE_SIZE)
470 		return 0;
471 	args->tname = new =
472 		page_address(rqstp->rq_respages[rqstp->rq_resused++]);
473 	args->tlen = len;
474 	/* first copy and check from the first page */
475 	old = (char*)p;
476 	vec = &rqstp->rq_arg.head[0];
477 	avail = vec->iov_len - (old - (char*)vec->iov_base);
478 	while (len && avail && *old) {
479 		*new++ = *old++;
480 		len--;
481 		avail--;
482 	}
483 	/* now copy next page if there is one */
484 	if (len && !avail && rqstp->rq_arg.page_len) {
485 		avail = rqstp->rq_arg.page_len;
486 		if (avail > PAGE_SIZE) avail = PAGE_SIZE;
487 		old = page_address(rqstp->rq_arg.pages[0]);
488 	}
489 	while (len && avail && *old) {
490 		*new++ = *old++;
491 		len--;
492 		avail--;
493 	}
494 	*new = '\0';
495 	if (len)
496 		return 0;
497 
498 	return 1;
499 }
500 
501 int
502 nfs3svc_decode_mknodargs(struct svc_rqst *rqstp, __be32 *p,
503 					struct nfsd3_mknodargs *args)
504 {
505 	if (!(p = decode_fh(p, &args->fh))
506 	 || !(p = decode_filename(p, &args->name, &args->len)))
507 		return 0;
508 
509 	args->ftype = ntohl(*p++);
510 
511 	if (args->ftype == NF3BLK  || args->ftype == NF3CHR
512 	 || args->ftype == NF3SOCK || args->ftype == NF3FIFO)
513 		p = decode_sattr3(p, &args->attrs);
514 
515 	if (args->ftype == NF3BLK || args->ftype == NF3CHR) {
516 		args->major = ntohl(*p++);
517 		args->minor = ntohl(*p++);
518 	}
519 
520 	return xdr_argsize_check(rqstp, p);
521 }
522 
523 int
524 nfs3svc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p,
525 					struct nfsd3_renameargs *args)
526 {
527 	if (!(p = decode_fh(p, &args->ffh))
528 	 || !(p = decode_filename(p, &args->fname, &args->flen))
529 	 || !(p = decode_fh(p, &args->tfh))
530 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
531 		return 0;
532 
533 	return xdr_argsize_check(rqstp, p);
534 }
535 
536 int
537 nfs3svc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p,
538 					struct nfsd3_readlinkargs *args)
539 {
540 	if (!(p = decode_fh(p, &args->fh)))
541 		return 0;
542 	args->buffer =
543 		page_address(rqstp->rq_respages[rqstp->rq_resused++]);
544 
545 	return xdr_argsize_check(rqstp, p);
546 }
547 
548 int
549 nfs3svc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p,
550 					struct nfsd3_linkargs *args)
551 {
552 	if (!(p = decode_fh(p, &args->ffh))
553 	 || !(p = decode_fh(p, &args->tfh))
554 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
555 		return 0;
556 
557 	return xdr_argsize_check(rqstp, p);
558 }
559 
560 int
561 nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p,
562 					struct nfsd3_readdirargs *args)
563 {
564 	if (!(p = decode_fh(p, &args->fh)))
565 		return 0;
566 	p = xdr_decode_hyper(p, &args->cookie);
567 	args->verf   = p; p += 2;
568 	args->dircount = ~0;
569 	args->count  = ntohl(*p++);
570 
571 	if (args->count > PAGE_SIZE)
572 		args->count = PAGE_SIZE;
573 
574 	args->buffer =
575 		page_address(rqstp->rq_respages[rqstp->rq_resused++]);
576 
577 	return xdr_argsize_check(rqstp, p);
578 }
579 
580 int
581 nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, __be32 *p,
582 					struct nfsd3_readdirargs *args)
583 {
584 	int len, pn;
585 	u32 max_blocksize = svc_max_payload(rqstp);
586 
587 	if (!(p = decode_fh(p, &args->fh)))
588 		return 0;
589 	p = xdr_decode_hyper(p, &args->cookie);
590 	args->verf     = p; p += 2;
591 	args->dircount = ntohl(*p++);
592 	args->count    = ntohl(*p++);
593 
594 	len = (args->count > max_blocksize) ? max_blocksize :
595 						  args->count;
596 	args->count = len;
597 
598 	while (len > 0) {
599 		pn = rqstp->rq_resused++;
600 		if (!args->buffer)
601 			args->buffer = page_address(rqstp->rq_respages[pn]);
602 		len -= PAGE_SIZE;
603 	}
604 
605 	return xdr_argsize_check(rqstp, p);
606 }
607 
608 int
609 nfs3svc_decode_commitargs(struct svc_rqst *rqstp, __be32 *p,
610 					struct nfsd3_commitargs *args)
611 {
612 	if (!(p = decode_fh(p, &args->fh)))
613 		return 0;
614 	p = xdr_decode_hyper(p, &args->offset);
615 	args->count = ntohl(*p++);
616 
617 	return xdr_argsize_check(rqstp, p);
618 }
619 
620 /*
621  * XDR encode functions
622  */
623 /*
624  * There must be an encoding function for void results so svc_process
625  * will work properly.
626  */
627 int
628 nfs3svc_encode_voidres(struct svc_rqst *rqstp, __be32 *p, void *dummy)
629 {
630 	return xdr_ressize_check(rqstp, p);
631 }
632 
633 /* GETATTR */
634 int
635 nfs3svc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p,
636 					struct nfsd3_attrstat *resp)
637 {
638 	if (resp->status == 0) {
639 		lease_get_mtime(resp->fh.fh_dentry->d_inode,
640 				&resp->stat.mtime);
641 		p = encode_fattr3(rqstp, p, &resp->fh, &resp->stat);
642 	}
643 	return xdr_ressize_check(rqstp, p);
644 }
645 
646 /* SETATTR, REMOVE, RMDIR */
647 int
648 nfs3svc_encode_wccstat(struct svc_rqst *rqstp, __be32 *p,
649 					struct nfsd3_attrstat *resp)
650 {
651 	p = encode_wcc_data(rqstp, p, &resp->fh);
652 	return xdr_ressize_check(rqstp, p);
653 }
654 
655 /* LOOKUP */
656 int
657 nfs3svc_encode_diropres(struct svc_rqst *rqstp, __be32 *p,
658 					struct nfsd3_diropres *resp)
659 {
660 	if (resp->status == 0) {
661 		p = encode_fh(p, &resp->fh);
662 		p = encode_post_op_attr(rqstp, p, &resp->fh);
663 	}
664 	p = encode_post_op_attr(rqstp, p, &resp->dirfh);
665 	return xdr_ressize_check(rqstp, p);
666 }
667 
668 /* ACCESS */
669 int
670 nfs3svc_encode_accessres(struct svc_rqst *rqstp, __be32 *p,
671 					struct nfsd3_accessres *resp)
672 {
673 	p = encode_post_op_attr(rqstp, p, &resp->fh);
674 	if (resp->status == 0)
675 		*p++ = htonl(resp->access);
676 	return xdr_ressize_check(rqstp, p);
677 }
678 
679 /* READLINK */
680 int
681 nfs3svc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p,
682 					struct nfsd3_readlinkres *resp)
683 {
684 	p = encode_post_op_attr(rqstp, p, &resp->fh);
685 	if (resp->status == 0) {
686 		*p++ = htonl(resp->len);
687 		xdr_ressize_check(rqstp, p);
688 		rqstp->rq_res.page_len = resp->len;
689 		if (resp->len & 3) {
690 			/* need to pad the tail */
691 			rqstp->rq_res.tail[0].iov_base = p;
692 			*p = 0;
693 			rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
694 		}
695 		return 1;
696 	} else
697 		return xdr_ressize_check(rqstp, p);
698 }
699 
700 /* READ */
701 int
702 nfs3svc_encode_readres(struct svc_rqst *rqstp, __be32 *p,
703 					struct nfsd3_readres *resp)
704 {
705 	p = encode_post_op_attr(rqstp, p, &resp->fh);
706 	if (resp->status == 0) {
707 		*p++ = htonl(resp->count);
708 		*p++ = htonl(resp->eof);
709 		*p++ = htonl(resp->count);	/* xdr opaque count */
710 		xdr_ressize_check(rqstp, p);
711 		/* now update rqstp->rq_res to reflect data aswell */
712 		rqstp->rq_res.page_len = resp->count;
713 		if (resp->count & 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->count & 3);
718 		}
719 		return 1;
720 	} else
721 		return xdr_ressize_check(rqstp, p);
722 }
723 
724 /* WRITE */
725 int
726 nfs3svc_encode_writeres(struct svc_rqst *rqstp, __be32 *p,
727 					struct nfsd3_writeres *resp)
728 {
729 	p = encode_wcc_data(rqstp, p, &resp->fh);
730 	if (resp->status == 0) {
731 		*p++ = htonl(resp->count);
732 		*p++ = htonl(resp->committed);
733 		*p++ = htonl(nfssvc_boot.tv_sec);
734 		*p++ = htonl(nfssvc_boot.tv_usec);
735 	}
736 	return xdr_ressize_check(rqstp, p);
737 }
738 
739 /* CREATE, MKDIR, SYMLINK, MKNOD */
740 int
741 nfs3svc_encode_createres(struct svc_rqst *rqstp, __be32 *p,
742 					struct nfsd3_diropres *resp)
743 {
744 	if (resp->status == 0) {
745 		*p++ = xdr_one;
746 		p = encode_fh(p, &resp->fh);
747 		p = encode_post_op_attr(rqstp, p, &resp->fh);
748 	}
749 	p = encode_wcc_data(rqstp, p, &resp->dirfh);
750 	return xdr_ressize_check(rqstp, p);
751 }
752 
753 /* RENAME */
754 int
755 nfs3svc_encode_renameres(struct svc_rqst *rqstp, __be32 *p,
756 					struct nfsd3_renameres *resp)
757 {
758 	p = encode_wcc_data(rqstp, p, &resp->ffh);
759 	p = encode_wcc_data(rqstp, p, &resp->tfh);
760 	return xdr_ressize_check(rqstp, p);
761 }
762 
763 /* LINK */
764 int
765 nfs3svc_encode_linkres(struct svc_rqst *rqstp, __be32 *p,
766 					struct nfsd3_linkres *resp)
767 {
768 	p = encode_post_op_attr(rqstp, p, &resp->fh);
769 	p = encode_wcc_data(rqstp, p, &resp->tfh);
770 	return xdr_ressize_check(rqstp, p);
771 }
772 
773 /* READDIR */
774 int
775 nfs3svc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p,
776 					struct nfsd3_readdirres *resp)
777 {
778 	p = encode_post_op_attr(rqstp, p, &resp->fh);
779 
780 	if (resp->status == 0) {
781 		/* stupid readdir cookie */
782 		memcpy(p, resp->verf, 8); p += 2;
783 		xdr_ressize_check(rqstp, p);
784 		if (rqstp->rq_res.head[0].iov_len + (2<<2) > PAGE_SIZE)
785 			return 1; /*No room for trailer */
786 		rqstp->rq_res.page_len = (resp->count) << 2;
787 
788 		/* add the 'tail' to the end of the 'head' page - page 0. */
789 		rqstp->rq_res.tail[0].iov_base = p;
790 		*p++ = 0;		/* no more entries */
791 		*p++ = htonl(resp->common.err == nfserr_eof);
792 		rqstp->rq_res.tail[0].iov_len = 2<<2;
793 		return 1;
794 	} else
795 		return xdr_ressize_check(rqstp, p);
796 }
797 
798 static __be32 *
799 encode_entry_baggage(struct nfsd3_readdirres *cd, __be32 *p, const char *name,
800 	     int namlen, u64 ino)
801 {
802 	*p++ = xdr_one;				 /* mark entry present */
803 	p    = xdr_encode_hyper(p, ino);	 /* file id */
804 	p    = xdr_encode_array(p, name, namlen);/* name length & name */
805 
806 	cd->offset = p;				/* remember pointer */
807 	p = xdr_encode_hyper(p, NFS_OFFSET_MAX);/* offset of next entry */
808 
809 	return p;
810 }
811 
812 static __be32 *
813 encode_entryplus_baggage(struct nfsd3_readdirres *cd, __be32 *p,
814 		struct svc_fh *fhp)
815 {
816 		p = encode_post_op_attr(cd->rqstp, p, fhp);
817 		*p++ = xdr_one;			/* yes, a file handle follows */
818 		p = encode_fh(p, fhp);
819 		fh_put(fhp);
820 		return p;
821 }
822 
823 static int
824 compose_entry_fh(struct nfsd3_readdirres *cd, struct svc_fh *fhp,
825 		const char *name, int namlen)
826 {
827 	struct svc_export	*exp;
828 	struct dentry		*dparent, *dchild;
829 	int rv = 0;
830 
831 	dparent = cd->fh.fh_dentry;
832 	exp  = cd->fh.fh_export;
833 
834 	fh_init(fhp, NFS3_FHSIZE);
835 	if (isdotent(name, namlen)) {
836 		if (namlen == 2) {
837 			dchild = dget_parent(dparent);
838 			if (dchild == dparent) {
839 				/* filesystem root - cannot return filehandle for ".." */
840 				dput(dchild);
841 				return 1;
842 			}
843 		} else
844 			dchild = dget(dparent);
845 	} else
846 		dchild = lookup_one_len(name, dparent, namlen);
847 	if (IS_ERR(dchild))
848 		return 1;
849 	if (d_mountpoint(dchild) ||
850 	    fh_compose(fhp, exp, dchild, &cd->fh) != 0 ||
851 	    !dchild->d_inode)
852 		rv = 1;
853 	dput(dchild);
854 	return rv;
855 }
856 
857 /*
858  * Encode a directory entry. This one works for both normal readdir
859  * and readdirplus.
860  * The normal readdir reply requires 2 (fileid) + 1 (stringlen)
861  * + string + 2 (cookie) + 1 (next) words, i.e. 6 + strlen.
862  *
863  * The readdirplus baggage is 1+21 words for post_op_attr, plus the
864  * file handle.
865  */
866 
867 #define NFS3_ENTRY_BAGGAGE	(2 + 1 + 2 + 1)
868 #define NFS3_ENTRYPLUS_BAGGAGE	(1 + 21 + 1 + (NFS3_FHSIZE >> 2))
869 static int
870 encode_entry(struct readdir_cd *ccd, const char *name, int namlen,
871 	     loff_t offset, u64 ino, unsigned int d_type, int plus)
872 {
873 	struct nfsd3_readdirres *cd = container_of(ccd, struct nfsd3_readdirres,
874 		       					common);
875 	__be32		*p = cd->buffer;
876 	caddr_t		curr_page_addr = NULL;
877 	int		pn;		/* current page number */
878 	int		slen;		/* string (name) length */
879 	int		elen;		/* estimated entry length in words */
880 	int		num_entry_words = 0;	/* actual number of words */
881 
882 	if (cd->offset) {
883 		u64 offset64 = offset;
884 
885 		if (unlikely(cd->offset1)) {
886 			/* we ended up with offset on a page boundary */
887 			*cd->offset = htonl(offset64 >> 32);
888 			*cd->offset1 = htonl(offset64 & 0xffffffff);
889 			cd->offset1 = NULL;
890 		} else {
891 			xdr_encode_hyper(cd->offset, offset64);
892 		}
893 	}
894 
895 	/*
896 	dprintk("encode_entry(%.*s @%ld%s)\n",
897 		namlen, name, (long) offset, plus? " plus" : "");
898 	 */
899 
900 	/* truncate filename if too long */
901 	if (namlen > NFS3_MAXNAMLEN)
902 		namlen = NFS3_MAXNAMLEN;
903 
904 	slen = XDR_QUADLEN(namlen);
905 	elen = slen + NFS3_ENTRY_BAGGAGE
906 		+ (plus? NFS3_ENTRYPLUS_BAGGAGE : 0);
907 
908 	if (cd->buflen < elen) {
909 		cd->common.err = nfserr_toosmall;
910 		return -EINVAL;
911 	}
912 
913 	/* determine which page in rq_respages[] we are currently filling */
914 	for (pn=1; pn < cd->rqstp->rq_resused; pn++) {
915 		curr_page_addr = page_address(cd->rqstp->rq_respages[pn]);
916 
917 		if (((caddr_t)cd->buffer >= curr_page_addr) &&
918 		    ((caddr_t)cd->buffer <  curr_page_addr + PAGE_SIZE))
919 			break;
920 	}
921 
922 	if ((caddr_t)(cd->buffer + elen) < (curr_page_addr + PAGE_SIZE)) {
923 		/* encode entry in current page */
924 
925 		p = encode_entry_baggage(cd, p, name, namlen, ino);
926 
927 		/* throw in readdirplus baggage */
928 		if (plus) {
929 			struct svc_fh	fh;
930 
931 			if (compose_entry_fh(cd, &fh, name, namlen) > 0) {
932 				*p++ = 0;
933 				*p++ = 0;
934 			} else
935 				p = encode_entryplus_baggage(cd, p, &fh);
936 		}
937 		num_entry_words = p - cd->buffer;
938 	} else if (cd->rqstp->rq_respages[pn+1] != NULL) {
939 		/* temporarily encode entry into next page, then move back to
940 		 * current and next page in rq_respages[] */
941 		__be32 *p1, *tmp;
942 		int len1, len2;
943 
944 		/* grab next page for temporary storage of entry */
945 		p1 = tmp = page_address(cd->rqstp->rq_respages[pn+1]);
946 
947 		p1 = encode_entry_baggage(cd, p1, name, namlen, ino);
948 
949 		/* throw in readdirplus baggage */
950 		if (plus) {
951 			struct svc_fh	fh;
952 
953 			if (compose_entry_fh(cd, &fh, name, namlen) > 0) {
954 				/* zero out the filehandle */
955 				*p1++ = 0;
956 				*p1++ = 0;
957 			} else
958 				p1 = encode_entryplus_baggage(cd, p1, &fh);
959 		}
960 
961 		/* determine entry word length and lengths to go in pages */
962 		num_entry_words = p1 - tmp;
963 		len1 = curr_page_addr + PAGE_SIZE - (caddr_t)cd->buffer;
964 		if ((num_entry_words << 2) < len1) {
965 			/* the actual number of words in the entry is less
966 			 * than elen and can still fit in the current page
967 			 */
968 			memmove(p, tmp, num_entry_words << 2);
969 			p += num_entry_words;
970 
971 			/* update offset */
972 			cd->offset = cd->buffer + (cd->offset - tmp);
973 		} else {
974 			unsigned int offset_r = (cd->offset - tmp) << 2;
975 
976 			/* update pointer to offset location.
977 			 * This is a 64bit quantity, so we need to
978 			 * deal with 3 cases:
979 			 *  -	entirely in first page
980 			 *  -	entirely in second page
981 			 *  -	4 bytes in each page
982 			 */
983 			if (offset_r + 8 <= len1) {
984 				cd->offset = p + (cd->offset - tmp);
985 			} else if (offset_r >= len1) {
986 				cd->offset -= len1 >> 2;
987 			} else {
988 				/* sitting on the fence */
989 				BUG_ON(offset_r != len1 - 4);
990 				cd->offset = p + (cd->offset - tmp);
991 				cd->offset1 = tmp;
992 			}
993 
994 			len2 = (num_entry_words << 2) - len1;
995 
996 			/* move from temp page to current and next pages */
997 			memmove(p, tmp, len1);
998 			memmove(tmp, (caddr_t)tmp+len1, len2);
999 
1000 			p = tmp + (len2 >> 2);
1001 		}
1002 	}
1003 	else {
1004 		cd->common.err = nfserr_toosmall;
1005 		return -EINVAL;
1006 	}
1007 
1008 	cd->buflen -= num_entry_words;
1009 	cd->buffer = p;
1010 	cd->common.err = nfs_ok;
1011 	return 0;
1012 
1013 }
1014 
1015 int
1016 nfs3svc_encode_entry(void *cd, const char *name,
1017 		     int namlen, loff_t offset, u64 ino, unsigned int d_type)
1018 {
1019 	return encode_entry(cd, name, namlen, offset, ino, d_type, 0);
1020 }
1021 
1022 int
1023 nfs3svc_encode_entry_plus(void *cd, const char *name,
1024 			  int namlen, loff_t offset, u64 ino,
1025 			  unsigned int d_type)
1026 {
1027 	return encode_entry(cd, name, namlen, offset, ino, d_type, 1);
1028 }
1029 
1030 /* FSSTAT */
1031 int
1032 nfs3svc_encode_fsstatres(struct svc_rqst *rqstp, __be32 *p,
1033 					struct nfsd3_fsstatres *resp)
1034 {
1035 	struct kstatfs	*s = &resp->stats;
1036 	u64		bs = s->f_bsize;
1037 
1038 	*p++ = xdr_zero;	/* no post_op_attr */
1039 
1040 	if (resp->status == 0) {
1041 		p = xdr_encode_hyper(p, bs * s->f_blocks);	/* total bytes */
1042 		p = xdr_encode_hyper(p, bs * s->f_bfree);	/* free bytes */
1043 		p = xdr_encode_hyper(p, bs * s->f_bavail);	/* user available bytes */
1044 		p = xdr_encode_hyper(p, s->f_files);	/* total inodes */
1045 		p = xdr_encode_hyper(p, s->f_ffree);	/* free inodes */
1046 		p = xdr_encode_hyper(p, s->f_ffree);	/* user available inodes */
1047 		*p++ = htonl(resp->invarsec);	/* mean unchanged time */
1048 	}
1049 	return xdr_ressize_check(rqstp, p);
1050 }
1051 
1052 /* FSINFO */
1053 int
1054 nfs3svc_encode_fsinfores(struct svc_rqst *rqstp, __be32 *p,
1055 					struct nfsd3_fsinfores *resp)
1056 {
1057 	*p++ = xdr_zero;	/* no post_op_attr */
1058 
1059 	if (resp->status == 0) {
1060 		*p++ = htonl(resp->f_rtmax);
1061 		*p++ = htonl(resp->f_rtpref);
1062 		*p++ = htonl(resp->f_rtmult);
1063 		*p++ = htonl(resp->f_wtmax);
1064 		*p++ = htonl(resp->f_wtpref);
1065 		*p++ = htonl(resp->f_wtmult);
1066 		*p++ = htonl(resp->f_dtpref);
1067 		p = xdr_encode_hyper(p, resp->f_maxfilesize);
1068 		*p++ = xdr_one;
1069 		*p++ = xdr_zero;
1070 		*p++ = htonl(resp->f_properties);
1071 	}
1072 
1073 	return xdr_ressize_check(rqstp, p);
1074 }
1075 
1076 /* PATHCONF */
1077 int
1078 nfs3svc_encode_pathconfres(struct svc_rqst *rqstp, __be32 *p,
1079 					struct nfsd3_pathconfres *resp)
1080 {
1081 	*p++ = xdr_zero;	/* no post_op_attr */
1082 
1083 	if (resp->status == 0) {
1084 		*p++ = htonl(resp->p_link_max);
1085 		*p++ = htonl(resp->p_name_max);
1086 		*p++ = htonl(resp->p_no_trunc);
1087 		*p++ = htonl(resp->p_chown_restricted);
1088 		*p++ = htonl(resp->p_case_insensitive);
1089 		*p++ = htonl(resp->p_case_preserving);
1090 	}
1091 
1092 	return xdr_ressize_check(rqstp, p);
1093 }
1094 
1095 /* COMMIT */
1096 int
1097 nfs3svc_encode_commitres(struct svc_rqst *rqstp, __be32 *p,
1098 					struct nfsd3_commitres *resp)
1099 {
1100 	p = encode_wcc_data(rqstp, p, &resp->fh);
1101 	/* Write verifier */
1102 	if (resp->status == 0) {
1103 		*p++ = htonl(nfssvc_boot.tv_sec);
1104 		*p++ = htonl(nfssvc_boot.tv_usec);
1105 	}
1106 	return xdr_ressize_check(rqstp, p);
1107 }
1108 
1109 /*
1110  * XDR release functions
1111  */
1112 int
1113 nfs3svc_release_fhandle(struct svc_rqst *rqstp, __be32 *p,
1114 					struct nfsd3_attrstat *resp)
1115 {
1116 	fh_put(&resp->fh);
1117 	return 1;
1118 }
1119 
1120 int
1121 nfs3svc_release_fhandle2(struct svc_rqst *rqstp, __be32 *p,
1122 					struct nfsd3_fhandle_pair *resp)
1123 {
1124 	fh_put(&resp->fh1);
1125 	fh_put(&resp->fh2);
1126 	return 1;
1127 }
1128