xref: /openbmc/linux/fs/nfsd/nfs3xdr.c (revision 22246614)
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 #include "auth.h"
25 
26 #define NFSDDBG_FACILITY		NFSDDBG_XDR
27 
28 
29 /*
30  * Mapping of S_IF* types to NFS file types
31  */
32 static u32	nfs3_ftypes[] = {
33 	NF3NON,  NF3FIFO, NF3CHR, NF3BAD,
34 	NF3DIR,  NF3BAD,  NF3BLK, NF3BAD,
35 	NF3REG,  NF3BAD,  NF3LNK, NF3BAD,
36 	NF3SOCK, NF3BAD,  NF3LNK, NF3BAD,
37 };
38 
39 /*
40  * XDR functions for basic NFS types
41  */
42 static __be32 *
43 encode_time3(__be32 *p, struct timespec *time)
44 {
45 	*p++ = htonl((u32) time->tv_sec); *p++ = htonl(time->tv_nsec);
46 	return p;
47 }
48 
49 static __be32 *
50 decode_time3(__be32 *p, struct timespec *time)
51 {
52 	time->tv_sec = ntohl(*p++);
53 	time->tv_nsec = ntohl(*p++);
54 	return p;
55 }
56 
57 static __be32 *
58 decode_fh(__be32 *p, struct svc_fh *fhp)
59 {
60 	unsigned int size;
61 	fh_init(fhp, NFS3_FHSIZE);
62 	size = ntohl(*p++);
63 	if (size > NFS3_FHSIZE)
64 		return NULL;
65 
66 	memcpy(&fhp->fh_handle.fh_base, p, size);
67 	fhp->fh_handle.fh_size = size;
68 	return p + XDR_QUADLEN(size);
69 }
70 
71 /* Helper function for NFSv3 ACL code */
72 __be32 *nfs3svc_decode_fh(__be32 *p, struct svc_fh *fhp)
73 {
74 	return decode_fh(p, fhp);
75 }
76 
77 static __be32 *
78 encode_fh(__be32 *p, struct svc_fh *fhp)
79 {
80 	unsigned int size = fhp->fh_handle.fh_size;
81 	*p++ = htonl(size);
82 	if (size) p[XDR_QUADLEN(size)-1]=0;
83 	memcpy(p, &fhp->fh_handle.fh_base, size);
84 	return p + XDR_QUADLEN(size);
85 }
86 
87 /*
88  * Decode a file name and make sure that the path contains
89  * no slashes or null bytes.
90  */
91 static __be32 *
92 decode_filename(__be32 *p, char **namp, unsigned int *lenp)
93 {
94 	char		*name;
95 	unsigned int	i;
96 
97 	if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS3_MAXNAMLEN)) != NULL) {
98 		for (i = 0, name = *namp; i < *lenp; i++, name++) {
99 			if (*name == '\0' || *name == '/')
100 				return NULL;
101 		}
102 	}
103 
104 	return p;
105 }
106 
107 static __be32 *
108 decode_sattr3(__be32 *p, struct iattr *iap)
109 {
110 	u32	tmp;
111 
112 	iap->ia_valid = 0;
113 
114 	if (*p++) {
115 		iap->ia_valid |= ATTR_MODE;
116 		iap->ia_mode = ntohl(*p++);
117 	}
118 	if (*p++) {
119 		iap->ia_valid |= ATTR_UID;
120 		iap->ia_uid = ntohl(*p++);
121 	}
122 	if (*p++) {
123 		iap->ia_valid |= ATTR_GID;
124 		iap->ia_gid = ntohl(*p++);
125 	}
126 	if (*p++) {
127 		u64	newsize;
128 
129 		iap->ia_valid |= ATTR_SIZE;
130 		p = xdr_decode_hyper(p, &newsize);
131 		if (newsize <= NFS_OFFSET_MAX)
132 			iap->ia_size = newsize;
133 		else
134 			iap->ia_size = NFS_OFFSET_MAX;
135 	}
136 	if ((tmp = ntohl(*p++)) == 1) {	/* set to server time */
137 		iap->ia_valid |= ATTR_ATIME;
138 	} else if (tmp == 2) {		/* set to client time */
139 		iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
140 		iap->ia_atime.tv_sec = ntohl(*p++);
141 		iap->ia_atime.tv_nsec = ntohl(*p++);
142 	}
143 	if ((tmp = ntohl(*p++)) == 1) {	/* set to server time */
144 		iap->ia_valid |= ATTR_MTIME;
145 	} else if (tmp == 2) {		/* set to client time */
146 		iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
147 		iap->ia_mtime.tv_sec = ntohl(*p++);
148 		iap->ia_mtime.tv_nsec = ntohl(*p++);
149 	}
150 	return p;
151 }
152 
153 static __be32 *encode_fsid(__be32 *p, struct svc_fh *fhp)
154 {
155 	u64 f;
156 	switch(fsid_source(fhp)) {
157 	default:
158 	case FSIDSOURCE_DEV:
159 		p = xdr_encode_hyper(p, (u64)huge_encode_dev
160 				     (fhp->fh_dentry->d_inode->i_sb->s_dev));
161 		break;
162 	case FSIDSOURCE_FSID:
163 		p = xdr_encode_hyper(p, (u64) fhp->fh_export->ex_fsid);
164 		break;
165 	case FSIDSOURCE_UUID:
166 		f = ((u64*)fhp->fh_export->ex_uuid)[0];
167 		f ^= ((u64*)fhp->fh_export->ex_uuid)[1];
168 		p = xdr_encode_hyper(p, f);
169 		break;
170 	}
171 	return p;
172 }
173 
174 static __be32 *
175 encode_fattr3(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp,
176 	      struct kstat *stat)
177 {
178 	*p++ = htonl(nfs3_ftypes[(stat->mode & S_IFMT) >> 12]);
179 	*p++ = htonl((u32) stat->mode);
180 	*p++ = htonl((u32) stat->nlink);
181 	*p++ = htonl((u32) nfsd_ruid(rqstp, stat->uid));
182 	*p++ = htonl((u32) nfsd_rgid(rqstp, stat->gid));
183 	if (S_ISLNK(stat->mode) && stat->size > NFS3_MAXPATHLEN) {
184 		p = xdr_encode_hyper(p, (u64) NFS3_MAXPATHLEN);
185 	} else {
186 		p = xdr_encode_hyper(p, (u64) stat->size);
187 	}
188 	p = xdr_encode_hyper(p, ((u64)stat->blocks) << 9);
189 	*p++ = htonl((u32) MAJOR(stat->rdev));
190 	*p++ = htonl((u32) MINOR(stat->rdev));
191 	p = encode_fsid(p, fhp);
192 	p = xdr_encode_hyper(p, stat->ino);
193 	p = encode_time3(p, &stat->atime);
194 	p = encode_time3(p, &stat->mtime);
195 	p = encode_time3(p, &stat->ctime);
196 
197 	return p;
198 }
199 
200 static __be32 *
201 encode_saved_post_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
202 {
203 	/* Attributes to follow */
204 	*p++ = xdr_one;
205 	return encode_fattr3(rqstp, p, fhp, &fhp->fh_post_attr);
206 }
207 
208 /*
209  * Encode post-operation attributes.
210  * The inode may be NULL if the call failed because of a stale file
211  * handle. In this case, no attributes are returned.
212  */
213 static __be32 *
214 encode_post_op_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
215 {
216 	struct dentry *dentry = fhp->fh_dentry;
217 	if (dentry && dentry->d_inode) {
218 	        int err;
219 		struct kstat stat;
220 
221 		err = vfs_getattr(fhp->fh_export->ex_path.mnt, dentry, &stat);
222 		if (!err) {
223 			*p++ = xdr_one;		/* attributes follow */
224 			lease_get_mtime(dentry->d_inode, &stat.mtime);
225 			return encode_fattr3(rqstp, p, fhp, &stat);
226 		}
227 	}
228 	*p++ = xdr_zero;
229 	return p;
230 }
231 
232 /* Helper for NFSv3 ACLs */
233 __be32 *
234 nfs3svc_encode_post_op_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
235 {
236 	return encode_post_op_attr(rqstp, p, fhp);
237 }
238 
239 /*
240  * Enocde weak cache consistency data
241  */
242 static __be32 *
243 encode_wcc_data(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
244 {
245 	struct dentry	*dentry = fhp->fh_dentry;
246 
247 	if (dentry && dentry->d_inode && fhp->fh_post_saved) {
248 		if (fhp->fh_pre_saved) {
249 			*p++ = xdr_one;
250 			p = xdr_encode_hyper(p, (u64) fhp->fh_pre_size);
251 			p = encode_time3(p, &fhp->fh_pre_mtime);
252 			p = encode_time3(p, &fhp->fh_pre_ctime);
253 		} else {
254 			*p++ = xdr_zero;
255 		}
256 		return encode_saved_post_attr(rqstp, p, fhp);
257 	}
258 	/* no pre- or post-attrs */
259 	*p++ = xdr_zero;
260 	return encode_post_op_attr(rqstp, p, fhp);
261 }
262 
263 /*
264  * Fill in the post_op attr for the wcc data
265  */
266 void fill_post_wcc(struct svc_fh *fhp)
267 {
268 	int err;
269 
270 	if (fhp->fh_post_saved)
271 		printk("nfsd: inode locked twice during operation.\n");
272 
273 	err = vfs_getattr(fhp->fh_export->ex_path.mnt, fhp->fh_dentry,
274 			&fhp->fh_post_attr);
275 	if (err)
276 		fhp->fh_post_saved = 0;
277 	else
278 		fhp->fh_post_saved = 1;
279 }
280 
281 /*
282  * XDR decode functions
283  */
284 int
285 nfs3svc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p, struct nfsd_fhandle *args)
286 {
287 	if (!(p = decode_fh(p, &args->fh)))
288 		return 0;
289 	return xdr_argsize_check(rqstp, p);
290 }
291 
292 int
293 nfs3svc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p,
294 					struct nfsd3_sattrargs *args)
295 {
296 	if (!(p = decode_fh(p, &args->fh)))
297 		return 0;
298 	p = decode_sattr3(p, &args->attrs);
299 
300 	if ((args->check_guard = ntohl(*p++)) != 0) {
301 		struct timespec time;
302 		p = decode_time3(p, &time);
303 		args->guardtime = time.tv_sec;
304 	}
305 
306 	return xdr_argsize_check(rqstp, p);
307 }
308 
309 int
310 nfs3svc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p,
311 					struct nfsd3_diropargs *args)
312 {
313 	if (!(p = decode_fh(p, &args->fh))
314 	 || !(p = decode_filename(p, &args->name, &args->len)))
315 		return 0;
316 
317 	return xdr_argsize_check(rqstp, p);
318 }
319 
320 int
321 nfs3svc_decode_accessargs(struct svc_rqst *rqstp, __be32 *p,
322 					struct nfsd3_accessargs *args)
323 {
324 	if (!(p = decode_fh(p, &args->fh)))
325 		return 0;
326 	args->access = ntohl(*p++);
327 
328 	return xdr_argsize_check(rqstp, p);
329 }
330 
331 int
332 nfs3svc_decode_readargs(struct svc_rqst *rqstp, __be32 *p,
333 					struct nfsd3_readargs *args)
334 {
335 	unsigned int len;
336 	int v,pn;
337 	u32 max_blocksize = svc_max_payload(rqstp);
338 
339 	if (!(p = decode_fh(p, &args->fh)))
340 		return 0;
341 	p = xdr_decode_hyper(p, &args->offset);
342 
343 	len = args->count = ntohl(*p++);
344 
345 	if (len > max_blocksize)
346 		len = max_blocksize;
347 
348 	/* set up the kvec */
349 	v=0;
350 	while (len > 0) {
351 		pn = rqstp->rq_resused++;
352 		rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_respages[pn]);
353 		rqstp->rq_vec[v].iov_len = len < PAGE_SIZE? len : PAGE_SIZE;
354 		len -= rqstp->rq_vec[v].iov_len;
355 		v++;
356 	}
357 	args->vlen = v;
358 	return xdr_argsize_check(rqstp, p);
359 }
360 
361 int
362 nfs3svc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
363 					struct nfsd3_writeargs *args)
364 {
365 	unsigned int len, v, hdr, dlen;
366 	u32 max_blocksize = svc_max_payload(rqstp);
367 
368 	if (!(p = decode_fh(p, &args->fh)))
369 		return 0;
370 	p = xdr_decode_hyper(p, &args->offset);
371 
372 	args->count = ntohl(*p++);
373 	args->stable = ntohl(*p++);
374 	len = args->len = ntohl(*p++);
375 	/*
376 	 * The count must equal the amount of data passed.
377 	 */
378 	if (args->count != args->len)
379 		return 0;
380 
381 	/*
382 	 * Check to make sure that we got the right number of
383 	 * bytes.
384 	 */
385 	hdr = (void*)p - rqstp->rq_arg.head[0].iov_base;
386 	dlen = rqstp->rq_arg.head[0].iov_len + rqstp->rq_arg.page_len
387 		- hdr;
388 	/*
389 	 * Round the length of the data which was specified up to
390 	 * the next multiple of XDR units and then compare that
391 	 * against the length which was actually received.
392 	 * Note that when RPCSEC/GSS (for example) is used, the
393 	 * data buffer can be padded so dlen might be larger
394 	 * than required.  It must never be smaller.
395 	 */
396 	if (dlen < XDR_QUADLEN(len)*4)
397 		return 0;
398 
399 	if (args->count > max_blocksize) {
400 		args->count = max_blocksize;
401 		len = args->len = max_blocksize;
402 	}
403 	rqstp->rq_vec[0].iov_base = (void*)p;
404 	rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr;
405 	v = 0;
406 	while (len > rqstp->rq_vec[v].iov_len) {
407 		len -= rqstp->rq_vec[v].iov_len;
408 		v++;
409 		rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_pages[v]);
410 		rqstp->rq_vec[v].iov_len = PAGE_SIZE;
411 	}
412 	rqstp->rq_vec[v].iov_len = len;
413 	args->vlen = v + 1;
414 	return 1;
415 }
416 
417 int
418 nfs3svc_decode_createargs(struct svc_rqst *rqstp, __be32 *p,
419 					struct nfsd3_createargs *args)
420 {
421 	if (!(p = decode_fh(p, &args->fh))
422 	 || !(p = decode_filename(p, &args->name, &args->len)))
423 		return 0;
424 
425 	switch (args->createmode = ntohl(*p++)) {
426 	case NFS3_CREATE_UNCHECKED:
427 	case NFS3_CREATE_GUARDED:
428 		p = decode_sattr3(p, &args->attrs);
429 		break;
430 	case NFS3_CREATE_EXCLUSIVE:
431 		args->verf = p;
432 		p += 2;
433 		break;
434 	default:
435 		return 0;
436 	}
437 
438 	return xdr_argsize_check(rqstp, p);
439 }
440 int
441 nfs3svc_decode_mkdirargs(struct svc_rqst *rqstp, __be32 *p,
442 					struct nfsd3_createargs *args)
443 {
444 	if (!(p = decode_fh(p, &args->fh)) ||
445 	    !(p = decode_filename(p, &args->name, &args->len)))
446 		return 0;
447 	p = decode_sattr3(p, &args->attrs);
448 
449 	return xdr_argsize_check(rqstp, p);
450 }
451 
452 int
453 nfs3svc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p,
454 					struct nfsd3_symlinkargs *args)
455 {
456 	unsigned int len, avail;
457 	char *old, *new;
458 	struct kvec *vec;
459 
460 	if (!(p = decode_fh(p, &args->ffh)) ||
461 	    !(p = decode_filename(p, &args->fname, &args->flen))
462 		)
463 		return 0;
464 	p = decode_sattr3(p, &args->attrs);
465 
466 	/* now decode the pathname, which might be larger than the first page.
467 	 * As we have to check for nul's anyway, we copy it into a new page
468 	 * This page appears in the rq_res.pages list, but as pages_len is always
469 	 * 0, it won't get in the way
470 	 */
471 	len = ntohl(*p++);
472 	if (len == 0 || len > NFS3_MAXPATHLEN || len >= PAGE_SIZE)
473 		return 0;
474 	args->tname = new =
475 		page_address(rqstp->rq_respages[rqstp->rq_resused++]);
476 	args->tlen = len;
477 	/* first copy and check from the first page */
478 	old = (char*)p;
479 	vec = &rqstp->rq_arg.head[0];
480 	avail = vec->iov_len - (old - (char*)vec->iov_base);
481 	while (len && avail && *old) {
482 		*new++ = *old++;
483 		len--;
484 		avail--;
485 	}
486 	/* now copy next page if there is one */
487 	if (len && !avail && rqstp->rq_arg.page_len) {
488 		avail = rqstp->rq_arg.page_len;
489 		if (avail > PAGE_SIZE)
490 			avail = PAGE_SIZE;
491 		old = page_address(rqstp->rq_arg.pages[0]);
492 	}
493 	while (len && avail && *old) {
494 		*new++ = *old++;
495 		len--;
496 		avail--;
497 	}
498 	*new = '\0';
499 	if (len)
500 		return 0;
501 
502 	return 1;
503 }
504 
505 int
506 nfs3svc_decode_mknodargs(struct svc_rqst *rqstp, __be32 *p,
507 					struct nfsd3_mknodargs *args)
508 {
509 	if (!(p = decode_fh(p, &args->fh))
510 	 || !(p = decode_filename(p, &args->name, &args->len)))
511 		return 0;
512 
513 	args->ftype = ntohl(*p++);
514 
515 	if (args->ftype == NF3BLK  || args->ftype == NF3CHR
516 	 || args->ftype == NF3SOCK || args->ftype == NF3FIFO)
517 		p = decode_sattr3(p, &args->attrs);
518 
519 	if (args->ftype == NF3BLK || args->ftype == NF3CHR) {
520 		args->major = ntohl(*p++);
521 		args->minor = ntohl(*p++);
522 	}
523 
524 	return xdr_argsize_check(rqstp, p);
525 }
526 
527 int
528 nfs3svc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p,
529 					struct nfsd3_renameargs *args)
530 {
531 	if (!(p = decode_fh(p, &args->ffh))
532 	 || !(p = decode_filename(p, &args->fname, &args->flen))
533 	 || !(p = decode_fh(p, &args->tfh))
534 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
535 		return 0;
536 
537 	return xdr_argsize_check(rqstp, p);
538 }
539 
540 int
541 nfs3svc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p,
542 					struct nfsd3_readlinkargs *args)
543 {
544 	if (!(p = decode_fh(p, &args->fh)))
545 		return 0;
546 	args->buffer =
547 		page_address(rqstp->rq_respages[rqstp->rq_resused++]);
548 
549 	return xdr_argsize_check(rqstp, p);
550 }
551 
552 int
553 nfs3svc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p,
554 					struct nfsd3_linkargs *args)
555 {
556 	if (!(p = decode_fh(p, &args->ffh))
557 	 || !(p = decode_fh(p, &args->tfh))
558 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
559 		return 0;
560 
561 	return xdr_argsize_check(rqstp, p);
562 }
563 
564 int
565 nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p,
566 					struct nfsd3_readdirargs *args)
567 {
568 	if (!(p = decode_fh(p, &args->fh)))
569 		return 0;
570 	p = xdr_decode_hyper(p, &args->cookie);
571 	args->verf   = p; p += 2;
572 	args->dircount = ~0;
573 	args->count  = ntohl(*p++);
574 
575 	if (args->count > PAGE_SIZE)
576 		args->count = PAGE_SIZE;
577 
578 	args->buffer =
579 		page_address(rqstp->rq_respages[rqstp->rq_resused++]);
580 
581 	return xdr_argsize_check(rqstp, p);
582 }
583 
584 int
585 nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, __be32 *p,
586 					struct nfsd3_readdirargs *args)
587 {
588 	int len, pn;
589 	u32 max_blocksize = svc_max_payload(rqstp);
590 
591 	if (!(p = decode_fh(p, &args->fh)))
592 		return 0;
593 	p = xdr_decode_hyper(p, &args->cookie);
594 	args->verf     = p; p += 2;
595 	args->dircount = ntohl(*p++);
596 	args->count    = ntohl(*p++);
597 
598 	len = (args->count > max_blocksize) ? max_blocksize :
599 						  args->count;
600 	args->count = len;
601 
602 	while (len > 0) {
603 		pn = rqstp->rq_resused++;
604 		if (!args->buffer)
605 			args->buffer = page_address(rqstp->rq_respages[pn]);
606 		len -= PAGE_SIZE;
607 	}
608 
609 	return xdr_argsize_check(rqstp, p);
610 }
611 
612 int
613 nfs3svc_decode_commitargs(struct svc_rqst *rqstp, __be32 *p,
614 					struct nfsd3_commitargs *args)
615 {
616 	if (!(p = decode_fh(p, &args->fh)))
617 		return 0;
618 	p = xdr_decode_hyper(p, &args->offset);
619 	args->count = ntohl(*p++);
620 
621 	return xdr_argsize_check(rqstp, p);
622 }
623 
624 /*
625  * XDR encode functions
626  */
627 /*
628  * There must be an encoding function for void results so svc_process
629  * will work properly.
630  */
631 int
632 nfs3svc_encode_voidres(struct svc_rqst *rqstp, __be32 *p, void *dummy)
633 {
634 	return xdr_ressize_check(rqstp, p);
635 }
636 
637 /* GETATTR */
638 int
639 nfs3svc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p,
640 					struct nfsd3_attrstat *resp)
641 {
642 	if (resp->status == 0) {
643 		lease_get_mtime(resp->fh.fh_dentry->d_inode,
644 				&resp->stat.mtime);
645 		p = encode_fattr3(rqstp, p, &resp->fh, &resp->stat);
646 	}
647 	return xdr_ressize_check(rqstp, p);
648 }
649 
650 /* SETATTR, REMOVE, RMDIR */
651 int
652 nfs3svc_encode_wccstat(struct svc_rqst *rqstp, __be32 *p,
653 					struct nfsd3_attrstat *resp)
654 {
655 	p = encode_wcc_data(rqstp, p, &resp->fh);
656 	return xdr_ressize_check(rqstp, p);
657 }
658 
659 /* LOOKUP */
660 int
661 nfs3svc_encode_diropres(struct svc_rqst *rqstp, __be32 *p,
662 					struct nfsd3_diropres *resp)
663 {
664 	if (resp->status == 0) {
665 		p = encode_fh(p, &resp->fh);
666 		p = encode_post_op_attr(rqstp, p, &resp->fh);
667 	}
668 	p = encode_post_op_attr(rqstp, p, &resp->dirfh);
669 	return xdr_ressize_check(rqstp, p);
670 }
671 
672 /* ACCESS */
673 int
674 nfs3svc_encode_accessres(struct svc_rqst *rqstp, __be32 *p,
675 					struct nfsd3_accessres *resp)
676 {
677 	p = encode_post_op_attr(rqstp, p, &resp->fh);
678 	if (resp->status == 0)
679 		*p++ = htonl(resp->access);
680 	return xdr_ressize_check(rqstp, p);
681 }
682 
683 /* READLINK */
684 int
685 nfs3svc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p,
686 					struct nfsd3_readlinkres *resp)
687 {
688 	p = encode_post_op_attr(rqstp, p, &resp->fh);
689 	if (resp->status == 0) {
690 		*p++ = htonl(resp->len);
691 		xdr_ressize_check(rqstp, p);
692 		rqstp->rq_res.page_len = resp->len;
693 		if (resp->len & 3) {
694 			/* need to pad the tail */
695 			rqstp->rq_res.tail[0].iov_base = p;
696 			*p = 0;
697 			rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
698 		}
699 		return 1;
700 	} else
701 		return xdr_ressize_check(rqstp, p);
702 }
703 
704 /* READ */
705 int
706 nfs3svc_encode_readres(struct svc_rqst *rqstp, __be32 *p,
707 					struct nfsd3_readres *resp)
708 {
709 	p = encode_post_op_attr(rqstp, p, &resp->fh);
710 	if (resp->status == 0) {
711 		*p++ = htonl(resp->count);
712 		*p++ = htonl(resp->eof);
713 		*p++ = htonl(resp->count);	/* xdr opaque count */
714 		xdr_ressize_check(rqstp, p);
715 		/* now update rqstp->rq_res to reflect data aswell */
716 		rqstp->rq_res.page_len = resp->count;
717 		if (resp->count & 3) {
718 			/* need to pad the tail */
719 			rqstp->rq_res.tail[0].iov_base = p;
720 			*p = 0;
721 			rqstp->rq_res.tail[0].iov_len = 4 - (resp->count & 3);
722 		}
723 		return 1;
724 	} else
725 		return xdr_ressize_check(rqstp, p);
726 }
727 
728 /* WRITE */
729 int
730 nfs3svc_encode_writeres(struct svc_rqst *rqstp, __be32 *p,
731 					struct nfsd3_writeres *resp)
732 {
733 	p = encode_wcc_data(rqstp, p, &resp->fh);
734 	if (resp->status == 0) {
735 		*p++ = htonl(resp->count);
736 		*p++ = htonl(resp->committed);
737 		*p++ = htonl(nfssvc_boot.tv_sec);
738 		*p++ = htonl(nfssvc_boot.tv_usec);
739 	}
740 	return xdr_ressize_check(rqstp, p);
741 }
742 
743 /* CREATE, MKDIR, SYMLINK, MKNOD */
744 int
745 nfs3svc_encode_createres(struct svc_rqst *rqstp, __be32 *p,
746 					struct nfsd3_diropres *resp)
747 {
748 	if (resp->status == 0) {
749 		*p++ = xdr_one;
750 		p = encode_fh(p, &resp->fh);
751 		p = encode_post_op_attr(rqstp, p, &resp->fh);
752 	}
753 	p = encode_wcc_data(rqstp, p, &resp->dirfh);
754 	return xdr_ressize_check(rqstp, p);
755 }
756 
757 /* RENAME */
758 int
759 nfs3svc_encode_renameres(struct svc_rqst *rqstp, __be32 *p,
760 					struct nfsd3_renameres *resp)
761 {
762 	p = encode_wcc_data(rqstp, p, &resp->ffh);
763 	p = encode_wcc_data(rqstp, p, &resp->tfh);
764 	return xdr_ressize_check(rqstp, p);
765 }
766 
767 /* LINK */
768 int
769 nfs3svc_encode_linkres(struct svc_rqst *rqstp, __be32 *p,
770 					struct nfsd3_linkres *resp)
771 {
772 	p = encode_post_op_attr(rqstp, p, &resp->fh);
773 	p = encode_wcc_data(rqstp, p, &resp->tfh);
774 	return xdr_ressize_check(rqstp, p);
775 }
776 
777 /* READDIR */
778 int
779 nfs3svc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p,
780 					struct nfsd3_readdirres *resp)
781 {
782 	p = encode_post_op_attr(rqstp, p, &resp->fh);
783 
784 	if (resp->status == 0) {
785 		/* stupid readdir cookie */
786 		memcpy(p, resp->verf, 8); p += 2;
787 		xdr_ressize_check(rqstp, p);
788 		if (rqstp->rq_res.head[0].iov_len + (2<<2) > PAGE_SIZE)
789 			return 1; /*No room for trailer */
790 		rqstp->rq_res.page_len = (resp->count) << 2;
791 
792 		/* add the 'tail' to the end of the 'head' page - page 0. */
793 		rqstp->rq_res.tail[0].iov_base = p;
794 		*p++ = 0;		/* no more entries */
795 		*p++ = htonl(resp->common.err == nfserr_eof);
796 		rqstp->rq_res.tail[0].iov_len = 2<<2;
797 		return 1;
798 	} else
799 		return xdr_ressize_check(rqstp, p);
800 }
801 
802 static __be32 *
803 encode_entry_baggage(struct nfsd3_readdirres *cd, __be32 *p, const char *name,
804 	     int namlen, u64 ino)
805 {
806 	*p++ = xdr_one;				 /* mark entry present */
807 	p    = xdr_encode_hyper(p, ino);	 /* file id */
808 	p    = xdr_encode_array(p, name, namlen);/* name length & name */
809 
810 	cd->offset = p;				/* remember pointer */
811 	p = xdr_encode_hyper(p, NFS_OFFSET_MAX);/* offset of next entry */
812 
813 	return p;
814 }
815 
816 static __be32 *
817 encode_entryplus_baggage(struct nfsd3_readdirres *cd, __be32 *p,
818 		struct svc_fh *fhp)
819 {
820 	p = encode_post_op_attr(cd->rqstp, p, fhp);
821 	*p++ = xdr_one;			/* yes, a file handle follows */
822 	p = encode_fh(p, fhp);
823 	fh_put(fhp);
824 	return p;
825 }
826 
827 static int
828 compose_entry_fh(struct nfsd3_readdirres *cd, struct svc_fh *fhp,
829 		const char *name, int namlen)
830 {
831 	struct svc_export	*exp;
832 	struct dentry		*dparent, *dchild;
833 	int rv = 0;
834 
835 	dparent = cd->fh.fh_dentry;
836 	exp  = cd->fh.fh_export;
837 
838 	fh_init(fhp, NFS3_FHSIZE);
839 	if (isdotent(name, namlen)) {
840 		if (namlen == 2) {
841 			dchild = dget_parent(dparent);
842 			if (dchild == dparent) {
843 				/* filesystem root - cannot return filehandle for ".." */
844 				dput(dchild);
845 				return 1;
846 			}
847 		} else
848 			dchild = dget(dparent);
849 	} else
850 		dchild = lookup_one_len(name, dparent, namlen);
851 	if (IS_ERR(dchild))
852 		return 1;
853 	if (d_mountpoint(dchild) ||
854 	    fh_compose(fhp, exp, dchild, &cd->fh) != 0 ||
855 	    !dchild->d_inode)
856 		rv = 1;
857 	dput(dchild);
858 	return rv;
859 }
860 
861 /*
862  * Encode a directory entry. This one works for both normal readdir
863  * and readdirplus.
864  * The normal readdir reply requires 2 (fileid) + 1 (stringlen)
865  * + string + 2 (cookie) + 1 (next) words, i.e. 6 + strlen.
866  *
867  * The readdirplus baggage is 1+21 words for post_op_attr, plus the
868  * file handle.
869  */
870 
871 #define NFS3_ENTRY_BAGGAGE	(2 + 1 + 2 + 1)
872 #define NFS3_ENTRYPLUS_BAGGAGE	(1 + 21 + 1 + (NFS3_FHSIZE >> 2))
873 static int
874 encode_entry(struct readdir_cd *ccd, const char *name, int namlen,
875 	     loff_t offset, u64 ino, unsigned int d_type, int plus)
876 {
877 	struct nfsd3_readdirres *cd = container_of(ccd, struct nfsd3_readdirres,
878 		       					common);
879 	__be32		*p = cd->buffer;
880 	caddr_t		curr_page_addr = NULL;
881 	int		pn;		/* current page number */
882 	int		slen;		/* string (name) length */
883 	int		elen;		/* estimated entry length in words */
884 	int		num_entry_words = 0;	/* actual number of words */
885 
886 	if (cd->offset) {
887 		u64 offset64 = offset;
888 
889 		if (unlikely(cd->offset1)) {
890 			/* we ended up with offset on a page boundary */
891 			*cd->offset = htonl(offset64 >> 32);
892 			*cd->offset1 = htonl(offset64 & 0xffffffff);
893 			cd->offset1 = NULL;
894 		} else {
895 			xdr_encode_hyper(cd->offset, offset64);
896 		}
897 	}
898 
899 	/*
900 	dprintk("encode_entry(%.*s @%ld%s)\n",
901 		namlen, name, (long) offset, plus? " plus" : "");
902 	 */
903 
904 	/* truncate filename if too long */
905 	if (namlen > NFS3_MAXNAMLEN)
906 		namlen = NFS3_MAXNAMLEN;
907 
908 	slen = XDR_QUADLEN(namlen);
909 	elen = slen + NFS3_ENTRY_BAGGAGE
910 		+ (plus? NFS3_ENTRYPLUS_BAGGAGE : 0);
911 
912 	if (cd->buflen < elen) {
913 		cd->common.err = nfserr_toosmall;
914 		return -EINVAL;
915 	}
916 
917 	/* determine which page in rq_respages[] we are currently filling */
918 	for (pn=1; pn < cd->rqstp->rq_resused; pn++) {
919 		curr_page_addr = page_address(cd->rqstp->rq_respages[pn]);
920 
921 		if (((caddr_t)cd->buffer >= curr_page_addr) &&
922 		    ((caddr_t)cd->buffer <  curr_page_addr + PAGE_SIZE))
923 			break;
924 	}
925 
926 	if ((caddr_t)(cd->buffer + elen) < (curr_page_addr + PAGE_SIZE)) {
927 		/* encode entry in current page */
928 
929 		p = encode_entry_baggage(cd, p, name, namlen, ino);
930 
931 		/* throw in readdirplus baggage */
932 		if (plus) {
933 			struct svc_fh	fh;
934 
935 			if (compose_entry_fh(cd, &fh, name, namlen) > 0) {
936 				*p++ = 0;
937 				*p++ = 0;
938 			} else
939 				p = encode_entryplus_baggage(cd, p, &fh);
940 		}
941 		num_entry_words = p - cd->buffer;
942 	} else if (cd->rqstp->rq_respages[pn+1] != NULL) {
943 		/* temporarily encode entry into next page, then move back to
944 		 * current and next page in rq_respages[] */
945 		__be32 *p1, *tmp;
946 		int len1, len2;
947 
948 		/* grab next page for temporary storage of entry */
949 		p1 = tmp = page_address(cd->rqstp->rq_respages[pn+1]);
950 
951 		p1 = encode_entry_baggage(cd, p1, name, namlen, ino);
952 
953 		/* throw in readdirplus baggage */
954 		if (plus) {
955 			struct svc_fh	fh;
956 
957 			if (compose_entry_fh(cd, &fh, name, namlen) > 0) {
958 				/* zero out the filehandle */
959 				*p1++ = 0;
960 				*p1++ = 0;
961 			} else
962 				p1 = encode_entryplus_baggage(cd, p1, &fh);
963 		}
964 
965 		/* determine entry word length and lengths to go in pages */
966 		num_entry_words = p1 - tmp;
967 		len1 = curr_page_addr + PAGE_SIZE - (caddr_t)cd->buffer;
968 		if ((num_entry_words << 2) < len1) {
969 			/* the actual number of words in the entry is less
970 			 * than elen and can still fit in the current page
971 			 */
972 			memmove(p, tmp, num_entry_words << 2);
973 			p += num_entry_words;
974 
975 			/* update offset */
976 			cd->offset = cd->buffer + (cd->offset - tmp);
977 		} else {
978 			unsigned int offset_r = (cd->offset - tmp) << 2;
979 
980 			/* update pointer to offset location.
981 			 * This is a 64bit quantity, so we need to
982 			 * deal with 3 cases:
983 			 *  -	entirely in first page
984 			 *  -	entirely in second page
985 			 *  -	4 bytes in each page
986 			 */
987 			if (offset_r + 8 <= len1) {
988 				cd->offset = p + (cd->offset - tmp);
989 			} else if (offset_r >= len1) {
990 				cd->offset -= len1 >> 2;
991 			} else {
992 				/* sitting on the fence */
993 				BUG_ON(offset_r != len1 - 4);
994 				cd->offset = p + (cd->offset - tmp);
995 				cd->offset1 = tmp;
996 			}
997 
998 			len2 = (num_entry_words << 2) - len1;
999 
1000 			/* move from temp page to current and next pages */
1001 			memmove(p, tmp, len1);
1002 			memmove(tmp, (caddr_t)tmp+len1, len2);
1003 
1004 			p = tmp + (len2 >> 2);
1005 		}
1006 	}
1007 	else {
1008 		cd->common.err = nfserr_toosmall;
1009 		return -EINVAL;
1010 	}
1011 
1012 	cd->buflen -= num_entry_words;
1013 	cd->buffer = p;
1014 	cd->common.err = nfs_ok;
1015 	return 0;
1016 
1017 }
1018 
1019 int
1020 nfs3svc_encode_entry(void *cd, const char *name,
1021 		     int namlen, loff_t offset, u64 ino, unsigned int d_type)
1022 {
1023 	return encode_entry(cd, name, namlen, offset, ino, d_type, 0);
1024 }
1025 
1026 int
1027 nfs3svc_encode_entry_plus(void *cd, const char *name,
1028 			  int namlen, loff_t offset, u64 ino,
1029 			  unsigned int d_type)
1030 {
1031 	return encode_entry(cd, name, namlen, offset, ino, d_type, 1);
1032 }
1033 
1034 /* FSSTAT */
1035 int
1036 nfs3svc_encode_fsstatres(struct svc_rqst *rqstp, __be32 *p,
1037 					struct nfsd3_fsstatres *resp)
1038 {
1039 	struct kstatfs	*s = &resp->stats;
1040 	u64		bs = s->f_bsize;
1041 
1042 	*p++ = xdr_zero;	/* no post_op_attr */
1043 
1044 	if (resp->status == 0) {
1045 		p = xdr_encode_hyper(p, bs * s->f_blocks);	/* total bytes */
1046 		p = xdr_encode_hyper(p, bs * s->f_bfree);	/* free bytes */
1047 		p = xdr_encode_hyper(p, bs * s->f_bavail);	/* user available bytes */
1048 		p = xdr_encode_hyper(p, s->f_files);	/* total inodes */
1049 		p = xdr_encode_hyper(p, s->f_ffree);	/* free inodes */
1050 		p = xdr_encode_hyper(p, s->f_ffree);	/* user available inodes */
1051 		*p++ = htonl(resp->invarsec);	/* mean unchanged time */
1052 	}
1053 	return xdr_ressize_check(rqstp, p);
1054 }
1055 
1056 /* FSINFO */
1057 int
1058 nfs3svc_encode_fsinfores(struct svc_rqst *rqstp, __be32 *p,
1059 					struct nfsd3_fsinfores *resp)
1060 {
1061 	*p++ = xdr_zero;	/* no post_op_attr */
1062 
1063 	if (resp->status == 0) {
1064 		*p++ = htonl(resp->f_rtmax);
1065 		*p++ = htonl(resp->f_rtpref);
1066 		*p++ = htonl(resp->f_rtmult);
1067 		*p++ = htonl(resp->f_wtmax);
1068 		*p++ = htonl(resp->f_wtpref);
1069 		*p++ = htonl(resp->f_wtmult);
1070 		*p++ = htonl(resp->f_dtpref);
1071 		p = xdr_encode_hyper(p, resp->f_maxfilesize);
1072 		*p++ = xdr_one;
1073 		*p++ = xdr_zero;
1074 		*p++ = htonl(resp->f_properties);
1075 	}
1076 
1077 	return xdr_ressize_check(rqstp, p);
1078 }
1079 
1080 /* PATHCONF */
1081 int
1082 nfs3svc_encode_pathconfres(struct svc_rqst *rqstp, __be32 *p,
1083 					struct nfsd3_pathconfres *resp)
1084 {
1085 	*p++ = xdr_zero;	/* no post_op_attr */
1086 
1087 	if (resp->status == 0) {
1088 		*p++ = htonl(resp->p_link_max);
1089 		*p++ = htonl(resp->p_name_max);
1090 		*p++ = htonl(resp->p_no_trunc);
1091 		*p++ = htonl(resp->p_chown_restricted);
1092 		*p++ = htonl(resp->p_case_insensitive);
1093 		*p++ = htonl(resp->p_case_preserving);
1094 	}
1095 
1096 	return xdr_ressize_check(rqstp, p);
1097 }
1098 
1099 /* COMMIT */
1100 int
1101 nfs3svc_encode_commitres(struct svc_rqst *rqstp, __be32 *p,
1102 					struct nfsd3_commitres *resp)
1103 {
1104 	p = encode_wcc_data(rqstp, p, &resp->fh);
1105 	/* Write verifier */
1106 	if (resp->status == 0) {
1107 		*p++ = htonl(nfssvc_boot.tv_sec);
1108 		*p++ = htonl(nfssvc_boot.tv_usec);
1109 	}
1110 	return xdr_ressize_check(rqstp, p);
1111 }
1112 
1113 /*
1114  * XDR release functions
1115  */
1116 int
1117 nfs3svc_release_fhandle(struct svc_rqst *rqstp, __be32 *p,
1118 					struct nfsd3_attrstat *resp)
1119 {
1120 	fh_put(&resp->fh);
1121 	return 1;
1122 }
1123 
1124 int
1125 nfs3svc_release_fhandle2(struct svc_rqst *rqstp, __be32 *p,
1126 					struct nfsd3_fhandle_pair *resp)
1127 {
1128 	fh_put(&resp->fh1);
1129 	fh_put(&resp->fh2);
1130 	return 1;
1131 }
1132