xref: /linux/fs/nfsd/nfs3xdr.c (revision c537b994505099b7197e7d3125b942ecbcc51eb6)
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 	struct dentry	*dentry = fhp->fh_dentry;
178 	struct timespec time;
179 
180 	*p++ = htonl(nfs3_ftypes[(stat->mode & S_IFMT) >> 12]);
181 	*p++ = htonl((u32) stat->mode);
182 	*p++ = htonl((u32) stat->nlink);
183 	*p++ = htonl((u32) nfsd_ruid(rqstp, stat->uid));
184 	*p++ = htonl((u32) nfsd_rgid(rqstp, stat->gid));
185 	if (S_ISLNK(stat->mode) && stat->size > NFS3_MAXPATHLEN) {
186 		p = xdr_encode_hyper(p, (u64) NFS3_MAXPATHLEN);
187 	} else {
188 		p = xdr_encode_hyper(p, (u64) stat->size);
189 	}
190 	p = xdr_encode_hyper(p, ((u64)stat->blocks) << 9);
191 	*p++ = htonl((u32) MAJOR(stat->rdev));
192 	*p++ = htonl((u32) MINOR(stat->rdev));
193 	p = encode_fsid(p, fhp);
194 	p = xdr_encode_hyper(p, (u64) stat->ino);
195 	p = encode_time3(p, &stat->atime);
196 	lease_get_mtime(dentry->d_inode, &time);
197 	p = encode_time3(p, &time);
198 	p = encode_time3(p, &stat->ctime);
199 
200 	return p;
201 }
202 
203 static __be32 *
204 encode_saved_post_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
205 {
206 	struct inode	*inode = fhp->fh_dentry->d_inode;
207 
208 	/* Attributes to follow */
209 	*p++ = xdr_one;
210 
211 	*p++ = htonl(nfs3_ftypes[(fhp->fh_post_mode & S_IFMT) >> 12]);
212 	*p++ = htonl((u32) fhp->fh_post_mode);
213 	*p++ = htonl((u32) fhp->fh_post_nlink);
214 	*p++ = htonl((u32) nfsd_ruid(rqstp, fhp->fh_post_uid));
215 	*p++ = htonl((u32) nfsd_rgid(rqstp, fhp->fh_post_gid));
216 	if (S_ISLNK(fhp->fh_post_mode) && fhp->fh_post_size > NFS3_MAXPATHLEN) {
217 		p = xdr_encode_hyper(p, (u64) NFS3_MAXPATHLEN);
218 	} else {
219 		p = xdr_encode_hyper(p, (u64) fhp->fh_post_size);
220 	}
221 	p = xdr_encode_hyper(p, ((u64)fhp->fh_post_blocks) << 9);
222 	*p++ = fhp->fh_post_rdev[0];
223 	*p++ = fhp->fh_post_rdev[1];
224 	p = encode_fsid(p, fhp);
225 	p = xdr_encode_hyper(p, (u64) inode->i_ino);
226 	p = encode_time3(p, &fhp->fh_post_atime);
227 	p = encode_time3(p, &fhp->fh_post_mtime);
228 	p = encode_time3(p, &fhp->fh_post_ctime);
229 
230 	return p;
231 }
232 
233 /*
234  * Encode post-operation attributes.
235  * The inode may be NULL if the call failed because of a stale file
236  * handle. In this case, no attributes are returned.
237  */
238 static __be32 *
239 encode_post_op_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
240 {
241 	struct dentry *dentry = fhp->fh_dentry;
242 	if (dentry && dentry->d_inode != NULL) {
243 	        int err;
244 		struct kstat stat;
245 
246 		err = vfs_getattr(fhp->fh_export->ex_mnt, dentry, &stat);
247 		if (!err) {
248 			*p++ = xdr_one;		/* attributes follow */
249 			return encode_fattr3(rqstp, p, fhp, &stat);
250 		}
251 	}
252 	*p++ = xdr_zero;
253 	return p;
254 }
255 
256 /* Helper for NFSv3 ACLs */
257 __be32 *
258 nfs3svc_encode_post_op_attr(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
259 {
260 	return encode_post_op_attr(rqstp, p, fhp);
261 }
262 
263 /*
264  * Enocde weak cache consistency data
265  */
266 static __be32 *
267 encode_wcc_data(struct svc_rqst *rqstp, __be32 *p, struct svc_fh *fhp)
268 {
269 	struct dentry	*dentry = fhp->fh_dentry;
270 
271 	if (dentry && dentry->d_inode && fhp->fh_post_saved) {
272 		if (fhp->fh_pre_saved) {
273 			*p++ = xdr_one;
274 			p = xdr_encode_hyper(p, (u64) fhp->fh_pre_size);
275 			p = encode_time3(p, &fhp->fh_pre_mtime);
276 			p = encode_time3(p, &fhp->fh_pre_ctime);
277 		} else {
278 			*p++ = xdr_zero;
279 		}
280 		return encode_saved_post_attr(rqstp, p, fhp);
281 	}
282 	/* no pre- or post-attrs */
283 	*p++ = xdr_zero;
284 	return encode_post_op_attr(rqstp, p, fhp);
285 }
286 
287 
288 /*
289  * XDR decode functions
290  */
291 int
292 nfs3svc_decode_fhandle(struct svc_rqst *rqstp, __be32 *p, struct nfsd_fhandle *args)
293 {
294 	if (!(p = decode_fh(p, &args->fh)))
295 		return 0;
296 	return xdr_argsize_check(rqstp, p);
297 }
298 
299 int
300 nfs3svc_decode_sattrargs(struct svc_rqst *rqstp, __be32 *p,
301 					struct nfsd3_sattrargs *args)
302 {
303 	if (!(p = decode_fh(p, &args->fh))
304 	 || !(p = decode_sattr3(p, &args->attrs)))
305 		return 0;
306 
307 	if ((args->check_guard = ntohl(*p++)) != 0) {
308 		struct timespec time;
309 		p = decode_time3(p, &time);
310 		args->guardtime = time.tv_sec;
311 	}
312 
313 	return xdr_argsize_check(rqstp, p);
314 }
315 
316 int
317 nfs3svc_decode_diropargs(struct svc_rqst *rqstp, __be32 *p,
318 					struct nfsd3_diropargs *args)
319 {
320 	if (!(p = decode_fh(p, &args->fh))
321 	 || !(p = decode_filename(p, &args->name, &args->len)))
322 		return 0;
323 
324 	return xdr_argsize_check(rqstp, p);
325 }
326 
327 int
328 nfs3svc_decode_accessargs(struct svc_rqst *rqstp, __be32 *p,
329 					struct nfsd3_accessargs *args)
330 {
331 	if (!(p = decode_fh(p, &args->fh)))
332 		return 0;
333 	args->access = ntohl(*p++);
334 
335 	return xdr_argsize_check(rqstp, p);
336 }
337 
338 int
339 nfs3svc_decode_readargs(struct svc_rqst *rqstp, __be32 *p,
340 					struct nfsd3_readargs *args)
341 {
342 	unsigned int len;
343 	int v,pn;
344 	u32 max_blocksize = svc_max_payload(rqstp);
345 
346 	if (!(p = decode_fh(p, &args->fh))
347 	 || !(p = xdr_decode_hyper(p, &args->offset)))
348 		return 0;
349 
350 	len = args->count = ntohl(*p++);
351 
352 	if (len > max_blocksize)
353 		len = max_blocksize;
354 
355 	/* set up the kvec */
356 	v=0;
357 	while (len > 0) {
358 		pn = rqstp->rq_resused++;
359 		rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_respages[pn]);
360 		rqstp->rq_vec[v].iov_len = len < PAGE_SIZE? len : PAGE_SIZE;
361 		len -= rqstp->rq_vec[v].iov_len;
362 		v++;
363 	}
364 	args->vlen = v;
365 	return xdr_argsize_check(rqstp, p);
366 }
367 
368 int
369 nfs3svc_decode_writeargs(struct svc_rqst *rqstp, __be32 *p,
370 					struct nfsd3_writeargs *args)
371 {
372 	unsigned int len, v, hdr;
373 	u32 max_blocksize = svc_max_payload(rqstp);
374 
375 	if (!(p = decode_fh(p, &args->fh))
376 	 || !(p = xdr_decode_hyper(p, &args->offset)))
377 		return 0;
378 
379 	args->count = ntohl(*p++);
380 	args->stable = ntohl(*p++);
381 	len = args->len = ntohl(*p++);
382 
383 	hdr = (void*)p - rqstp->rq_arg.head[0].iov_base;
384 	if (rqstp->rq_arg.len < hdr ||
385 	    rqstp->rq_arg.len - hdr < len)
386 		return 0;
387 
388 	rqstp->rq_vec[0].iov_base = (void*)p;
389 	rqstp->rq_vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr;
390 
391 	if (len > max_blocksize)
392 		len = max_blocksize;
393 	v=  0;
394 	while (len > rqstp->rq_vec[v].iov_len) {
395 		len -= rqstp->rq_vec[v].iov_len;
396 		v++;
397 		rqstp->rq_vec[v].iov_base = page_address(rqstp->rq_pages[v]);
398 		rqstp->rq_vec[v].iov_len = PAGE_SIZE;
399 	}
400 	rqstp->rq_vec[v].iov_len = len;
401 	args->vlen = v+1;
402 
403 	return args->count == args->len && rqstp->rq_vec[0].iov_len > 0;
404 }
405 
406 int
407 nfs3svc_decode_createargs(struct svc_rqst *rqstp, __be32 *p,
408 					struct nfsd3_createargs *args)
409 {
410 	if (!(p = decode_fh(p, &args->fh))
411 	 || !(p = decode_filename(p, &args->name, &args->len)))
412 		return 0;
413 
414 	switch (args->createmode = ntohl(*p++)) {
415 	case NFS3_CREATE_UNCHECKED:
416 	case NFS3_CREATE_GUARDED:
417 		if (!(p = decode_sattr3(p, &args->attrs)))
418 			return 0;
419 		break;
420 	case NFS3_CREATE_EXCLUSIVE:
421 		args->verf = p;
422 		p += 2;
423 		break;
424 	default:
425 		return 0;
426 	}
427 
428 	return xdr_argsize_check(rqstp, p);
429 }
430 int
431 nfs3svc_decode_mkdirargs(struct svc_rqst *rqstp, __be32 *p,
432 					struct nfsd3_createargs *args)
433 {
434 	if (!(p = decode_fh(p, &args->fh))
435 	 || !(p = decode_filename(p, &args->name, &args->len))
436 	 || !(p = decode_sattr3(p, &args->attrs)))
437 		return 0;
438 
439 	return xdr_argsize_check(rqstp, p);
440 }
441 
442 int
443 nfs3svc_decode_symlinkargs(struct svc_rqst *rqstp, __be32 *p,
444 					struct nfsd3_symlinkargs *args)
445 {
446 	unsigned int len;
447 	int avail;
448 	char *old, *new;
449 	struct kvec *vec;
450 
451 	if (!(p = decode_fh(p, &args->ffh))
452 	 || !(p = decode_filename(p, &args->fname, &args->flen))
453 	 || !(p = decode_sattr3(p, &args->attrs))
454 		)
455 		return 0;
456 	/* now decode the pathname, which might be larger than the first page.
457 	 * As we have to check for nul's anyway, we copy it into a new page
458 	 * This page appears in the rq_res.pages list, but as pages_len is always
459 	 * 0, it won't get in the way
460 	 */
461 	len = ntohl(*p++);
462 	if (len == 0 || len > NFS3_MAXPATHLEN || len >= PAGE_SIZE)
463 		return 0;
464 	args->tname = new =
465 		page_address(rqstp->rq_respages[rqstp->rq_resused++]);
466 	args->tlen = len;
467 	/* first copy and check from the first page */
468 	old = (char*)p;
469 	vec = &rqstp->rq_arg.head[0];
470 	avail = vec->iov_len - (old - (char*)vec->iov_base);
471 	while (len && avail && *old) {
472 		*new++ = *old++;
473 		len--;
474 		avail--;
475 	}
476 	/* now copy next page if there is one */
477 	if (len && !avail && rqstp->rq_arg.page_len) {
478 		avail = rqstp->rq_arg.page_len;
479 		if (avail > PAGE_SIZE) avail = PAGE_SIZE;
480 		old = page_address(rqstp->rq_arg.pages[0]);
481 	}
482 	while (len && avail && *old) {
483 		*new++ = *old++;
484 		len--;
485 		avail--;
486 	}
487 	*new = '\0';
488 	if (len)
489 		return 0;
490 
491 	return 1;
492 }
493 
494 int
495 nfs3svc_decode_mknodargs(struct svc_rqst *rqstp, __be32 *p,
496 					struct nfsd3_mknodargs *args)
497 {
498 	if (!(p = decode_fh(p, &args->fh))
499 	 || !(p = decode_filename(p, &args->name, &args->len)))
500 		return 0;
501 
502 	args->ftype = ntohl(*p++);
503 
504 	if (args->ftype == NF3BLK  || args->ftype == NF3CHR
505 	 || args->ftype == NF3SOCK || args->ftype == NF3FIFO) {
506 		if (!(p = decode_sattr3(p, &args->attrs)))
507 			return 0;
508 	}
509 
510 	if (args->ftype == NF3BLK || args->ftype == NF3CHR) {
511 		args->major = ntohl(*p++);
512 		args->minor = ntohl(*p++);
513 	}
514 
515 	return xdr_argsize_check(rqstp, p);
516 }
517 
518 int
519 nfs3svc_decode_renameargs(struct svc_rqst *rqstp, __be32 *p,
520 					struct nfsd3_renameargs *args)
521 {
522 	if (!(p = decode_fh(p, &args->ffh))
523 	 || !(p = decode_filename(p, &args->fname, &args->flen))
524 	 || !(p = decode_fh(p, &args->tfh))
525 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
526 		return 0;
527 
528 	return xdr_argsize_check(rqstp, p);
529 }
530 
531 int
532 nfs3svc_decode_readlinkargs(struct svc_rqst *rqstp, __be32 *p,
533 					struct nfsd3_readlinkargs *args)
534 {
535 	if (!(p = decode_fh(p, &args->fh)))
536 		return 0;
537 	args->buffer =
538 		page_address(rqstp->rq_respages[rqstp->rq_resused++]);
539 
540 	return xdr_argsize_check(rqstp, p);
541 }
542 
543 int
544 nfs3svc_decode_linkargs(struct svc_rqst *rqstp, __be32 *p,
545 					struct nfsd3_linkargs *args)
546 {
547 	if (!(p = decode_fh(p, &args->ffh))
548 	 || !(p = decode_fh(p, &args->tfh))
549 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
550 		return 0;
551 
552 	return xdr_argsize_check(rqstp, p);
553 }
554 
555 int
556 nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, __be32 *p,
557 					struct nfsd3_readdirargs *args)
558 {
559 	if (!(p = decode_fh(p, &args->fh)))
560 		return 0;
561 	p = xdr_decode_hyper(p, &args->cookie);
562 	args->verf   = p; p += 2;
563 	args->dircount = ~0;
564 	args->count  = ntohl(*p++);
565 
566 	if (args->count > PAGE_SIZE)
567 		args->count = PAGE_SIZE;
568 
569 	args->buffer =
570 		page_address(rqstp->rq_respages[rqstp->rq_resused++]);
571 
572 	return xdr_argsize_check(rqstp, p);
573 }
574 
575 int
576 nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, __be32 *p,
577 					struct nfsd3_readdirargs *args)
578 {
579 	int len, pn;
580 	u32 max_blocksize = svc_max_payload(rqstp);
581 
582 	if (!(p = decode_fh(p, &args->fh)))
583 		return 0;
584 	p = xdr_decode_hyper(p, &args->cookie);
585 	args->verf     = p; p += 2;
586 	args->dircount = ntohl(*p++);
587 	args->count    = ntohl(*p++);
588 
589 	len = (args->count > max_blocksize) ? max_blocksize :
590 						  args->count;
591 	args->count = len;
592 
593 	while (len > 0) {
594 		pn = rqstp->rq_resused++;
595 		if (!args->buffer)
596 			args->buffer = page_address(rqstp->rq_respages[pn]);
597 		len -= PAGE_SIZE;
598 	}
599 
600 	return xdr_argsize_check(rqstp, p);
601 }
602 
603 int
604 nfs3svc_decode_commitargs(struct svc_rqst *rqstp, __be32 *p,
605 					struct nfsd3_commitargs *args)
606 {
607 	if (!(p = decode_fh(p, &args->fh)))
608 		return 0;
609 	p = xdr_decode_hyper(p, &args->offset);
610 	args->count = ntohl(*p++);
611 
612 	return xdr_argsize_check(rqstp, p);
613 }
614 
615 /*
616  * XDR encode functions
617  */
618 /*
619  * There must be an encoding function for void results so svc_process
620  * will work properly.
621  */
622 int
623 nfs3svc_encode_voidres(struct svc_rqst *rqstp, __be32 *p, void *dummy)
624 {
625 	return xdr_ressize_check(rqstp, p);
626 }
627 
628 /* GETATTR */
629 int
630 nfs3svc_encode_attrstat(struct svc_rqst *rqstp, __be32 *p,
631 					struct nfsd3_attrstat *resp)
632 {
633 	if (resp->status == 0)
634 		p = encode_fattr3(rqstp, p, &resp->fh, &resp->stat);
635 	return xdr_ressize_check(rqstp, p);
636 }
637 
638 /* SETATTR, REMOVE, RMDIR */
639 int
640 nfs3svc_encode_wccstat(struct svc_rqst *rqstp, __be32 *p,
641 					struct nfsd3_attrstat *resp)
642 {
643 	p = encode_wcc_data(rqstp, p, &resp->fh);
644 	return xdr_ressize_check(rqstp, p);
645 }
646 
647 /* LOOKUP */
648 int
649 nfs3svc_encode_diropres(struct svc_rqst *rqstp, __be32 *p,
650 					struct nfsd3_diropres *resp)
651 {
652 	if (resp->status == 0) {
653 		p = encode_fh(p, &resp->fh);
654 		p = encode_post_op_attr(rqstp, p, &resp->fh);
655 	}
656 	p = encode_post_op_attr(rqstp, p, &resp->dirfh);
657 	return xdr_ressize_check(rqstp, p);
658 }
659 
660 /* ACCESS */
661 int
662 nfs3svc_encode_accessres(struct svc_rqst *rqstp, __be32 *p,
663 					struct nfsd3_accessres *resp)
664 {
665 	p = encode_post_op_attr(rqstp, p, &resp->fh);
666 	if (resp->status == 0)
667 		*p++ = htonl(resp->access);
668 	return xdr_ressize_check(rqstp, p);
669 }
670 
671 /* READLINK */
672 int
673 nfs3svc_encode_readlinkres(struct svc_rqst *rqstp, __be32 *p,
674 					struct nfsd3_readlinkres *resp)
675 {
676 	p = encode_post_op_attr(rqstp, p, &resp->fh);
677 	if (resp->status == 0) {
678 		*p++ = htonl(resp->len);
679 		xdr_ressize_check(rqstp, p);
680 		rqstp->rq_res.page_len = resp->len;
681 		if (resp->len & 3) {
682 			/* need to pad the tail */
683 			rqstp->rq_res.tail[0].iov_base = p;
684 			*p = 0;
685 			rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
686 		}
687 		return 1;
688 	} else
689 		return xdr_ressize_check(rqstp, p);
690 }
691 
692 /* READ */
693 int
694 nfs3svc_encode_readres(struct svc_rqst *rqstp, __be32 *p,
695 					struct nfsd3_readres *resp)
696 {
697 	p = encode_post_op_attr(rqstp, p, &resp->fh);
698 	if (resp->status == 0) {
699 		*p++ = htonl(resp->count);
700 		*p++ = htonl(resp->eof);
701 		*p++ = htonl(resp->count);	/* xdr opaque count */
702 		xdr_ressize_check(rqstp, p);
703 		/* now update rqstp->rq_res to reflect data aswell */
704 		rqstp->rq_res.page_len = resp->count;
705 		if (resp->count & 3) {
706 			/* need to pad the tail */
707 			rqstp->rq_res.tail[0].iov_base = p;
708 			*p = 0;
709 			rqstp->rq_res.tail[0].iov_len = 4 - (resp->count & 3);
710 		}
711 		return 1;
712 	} else
713 		return xdr_ressize_check(rqstp, p);
714 }
715 
716 /* WRITE */
717 int
718 nfs3svc_encode_writeres(struct svc_rqst *rqstp, __be32 *p,
719 					struct nfsd3_writeres *resp)
720 {
721 	p = encode_wcc_data(rqstp, p, &resp->fh);
722 	if (resp->status == 0) {
723 		*p++ = htonl(resp->count);
724 		*p++ = htonl(resp->committed);
725 		*p++ = htonl(nfssvc_boot.tv_sec);
726 		*p++ = htonl(nfssvc_boot.tv_usec);
727 	}
728 	return xdr_ressize_check(rqstp, p);
729 }
730 
731 /* CREATE, MKDIR, SYMLINK, MKNOD */
732 int
733 nfs3svc_encode_createres(struct svc_rqst *rqstp, __be32 *p,
734 					struct nfsd3_diropres *resp)
735 {
736 	if (resp->status == 0) {
737 		*p++ = xdr_one;
738 		p = encode_fh(p, &resp->fh);
739 		p = encode_post_op_attr(rqstp, p, &resp->fh);
740 	}
741 	p = encode_wcc_data(rqstp, p, &resp->dirfh);
742 	return xdr_ressize_check(rqstp, p);
743 }
744 
745 /* RENAME */
746 int
747 nfs3svc_encode_renameres(struct svc_rqst *rqstp, __be32 *p,
748 					struct nfsd3_renameres *resp)
749 {
750 	p = encode_wcc_data(rqstp, p, &resp->ffh);
751 	p = encode_wcc_data(rqstp, p, &resp->tfh);
752 	return xdr_ressize_check(rqstp, p);
753 }
754 
755 /* LINK */
756 int
757 nfs3svc_encode_linkres(struct svc_rqst *rqstp, __be32 *p,
758 					struct nfsd3_linkres *resp)
759 {
760 	p = encode_post_op_attr(rqstp, p, &resp->fh);
761 	p = encode_wcc_data(rqstp, p, &resp->tfh);
762 	return xdr_ressize_check(rqstp, p);
763 }
764 
765 /* READDIR */
766 int
767 nfs3svc_encode_readdirres(struct svc_rqst *rqstp, __be32 *p,
768 					struct nfsd3_readdirres *resp)
769 {
770 	p = encode_post_op_attr(rqstp, p, &resp->fh);
771 
772 	if (resp->status == 0) {
773 		/* stupid readdir cookie */
774 		memcpy(p, resp->verf, 8); p += 2;
775 		xdr_ressize_check(rqstp, p);
776 		if (rqstp->rq_res.head[0].iov_len + (2<<2) > PAGE_SIZE)
777 			return 1; /*No room for trailer */
778 		rqstp->rq_res.page_len = (resp->count) << 2;
779 
780 		/* add the 'tail' to the end of the 'head' page - page 0. */
781 		rqstp->rq_res.tail[0].iov_base = p;
782 		*p++ = 0;		/* no more entries */
783 		*p++ = htonl(resp->common.err == nfserr_eof);
784 		rqstp->rq_res.tail[0].iov_len = 2<<2;
785 		return 1;
786 	} else
787 		return xdr_ressize_check(rqstp, p);
788 }
789 
790 static __be32 *
791 encode_entry_baggage(struct nfsd3_readdirres *cd, __be32 *p, const char *name,
792 	     int namlen, ino_t ino)
793 {
794 	*p++ = xdr_one;				 /* mark entry present */
795 	p    = xdr_encode_hyper(p, ino);	 /* file id */
796 	p    = xdr_encode_array(p, name, namlen);/* name length & name */
797 
798 	cd->offset = p;				/* remember pointer */
799 	p = xdr_encode_hyper(p, NFS_OFFSET_MAX);/* offset of next entry */
800 
801 	return p;
802 }
803 
804 static __be32 *
805 encode_entryplus_baggage(struct nfsd3_readdirres *cd, __be32 *p,
806 		struct svc_fh *fhp)
807 {
808 		p = encode_post_op_attr(cd->rqstp, p, fhp);
809 		*p++ = xdr_one;			/* yes, a file handle follows */
810 		p = encode_fh(p, fhp);
811 		fh_put(fhp);
812 		return p;
813 }
814 
815 static int
816 compose_entry_fh(struct nfsd3_readdirres *cd, struct svc_fh *fhp,
817 		const char *name, int namlen)
818 {
819 	struct svc_export	*exp;
820 	struct dentry		*dparent, *dchild;
821 	int rv = 0;
822 
823 	dparent = cd->fh.fh_dentry;
824 	exp  = cd->fh.fh_export;
825 
826 	fh_init(fhp, NFS3_FHSIZE);
827 	if (isdotent(name, namlen)) {
828 		if (namlen == 2) {
829 			dchild = dget_parent(dparent);
830 			if (dchild == dparent) {
831 				/* filesystem root - cannot return filehandle for ".." */
832 				dput(dchild);
833 				return 1;
834 			}
835 		} else
836 			dchild = dget(dparent);
837 	} else
838 		dchild = lookup_one_len(name, dparent, namlen);
839 	if (IS_ERR(dchild))
840 		return 1;
841 	if (d_mountpoint(dchild) ||
842 	    fh_compose(fhp, exp, dchild, &cd->fh) != 0 ||
843 	    !dchild->d_inode)
844 		rv = 1;
845 	dput(dchild);
846 	return rv;
847 }
848 
849 /*
850  * Encode a directory entry. This one works for both normal readdir
851  * and readdirplus.
852  * The normal readdir reply requires 2 (fileid) + 1 (stringlen)
853  * + string + 2 (cookie) + 1 (next) words, i.e. 6 + strlen.
854  *
855  * The readdirplus baggage is 1+21 words for post_op_attr, plus the
856  * file handle.
857  */
858 
859 #define NFS3_ENTRY_BAGGAGE	(2 + 1 + 2 + 1)
860 #define NFS3_ENTRYPLUS_BAGGAGE	(1 + 21 + 1 + (NFS3_FHSIZE >> 2))
861 static int
862 encode_entry(struct readdir_cd *ccd, const char *name,
863 	     int namlen, off_t offset, ino_t ino, unsigned int d_type, int plus)
864 {
865 	struct nfsd3_readdirres *cd = container_of(ccd, struct nfsd3_readdirres,
866 		       					common);
867 	__be32		*p = cd->buffer;
868 	caddr_t		curr_page_addr = NULL;
869 	int		pn;		/* current page number */
870 	int		slen;		/* string (name) length */
871 	int		elen;		/* estimated entry length in words */
872 	int		num_entry_words = 0;	/* actual number of words */
873 
874 	if (cd->offset) {
875 		u64 offset64 = offset;
876 
877 		if (unlikely(cd->offset1)) {
878 			/* we ended up with offset on a page boundary */
879 			*cd->offset = htonl(offset64 >> 32);
880 			*cd->offset1 = htonl(offset64 & 0xffffffff);
881 			cd->offset1 = NULL;
882 		} else {
883 			xdr_encode_hyper(cd->offset, (u64) offset);
884 		}
885 	}
886 
887 	/*
888 	dprintk("encode_entry(%.*s @%ld%s)\n",
889 		namlen, name, (long) offset, plus? " plus" : "");
890 	 */
891 
892 	/* truncate filename if too long */
893 	if (namlen > NFS3_MAXNAMLEN)
894 		namlen = NFS3_MAXNAMLEN;
895 
896 	slen = XDR_QUADLEN(namlen);
897 	elen = slen + NFS3_ENTRY_BAGGAGE
898 		+ (plus? NFS3_ENTRYPLUS_BAGGAGE : 0);
899 
900 	if (cd->buflen < elen) {
901 		cd->common.err = nfserr_toosmall;
902 		return -EINVAL;
903 	}
904 
905 	/* determine which page in rq_respages[] we are currently filling */
906 	for (pn=1; pn < cd->rqstp->rq_resused; pn++) {
907 		curr_page_addr = page_address(cd->rqstp->rq_respages[pn]);
908 
909 		if (((caddr_t)cd->buffer >= curr_page_addr) &&
910 		    ((caddr_t)cd->buffer <  curr_page_addr + PAGE_SIZE))
911 			break;
912 	}
913 
914 	if ((caddr_t)(cd->buffer + elen) < (curr_page_addr + PAGE_SIZE)) {
915 		/* encode entry in current page */
916 
917 		p = encode_entry_baggage(cd, p, name, namlen, ino);
918 
919 		/* throw in readdirplus baggage */
920 		if (plus) {
921 			struct svc_fh	fh;
922 
923 			if (compose_entry_fh(cd, &fh, name, namlen) > 0) {
924 				*p++ = 0;
925 				*p++ = 0;
926 			} else
927 				p = encode_entryplus_baggage(cd, p, &fh);
928 		}
929 		num_entry_words = p - cd->buffer;
930 	} else if (cd->rqstp->rq_respages[pn+1] != NULL) {
931 		/* temporarily encode entry into next page, then move back to
932 		 * current and next page in rq_respages[] */
933 		__be32 *p1, *tmp;
934 		int len1, len2;
935 
936 		/* grab next page for temporary storage of entry */
937 		p1 = tmp = page_address(cd->rqstp->rq_respages[pn+1]);
938 
939 		p1 = encode_entry_baggage(cd, p1, name, namlen, ino);
940 
941 		/* throw in readdirplus baggage */
942 		if (plus) {
943 			struct svc_fh	fh;
944 
945 			if (compose_entry_fh(cd, &fh, name, namlen) > 0) {
946 				/* zero out the filehandle */
947 				*p1++ = 0;
948 				*p1++ = 0;
949 			} else
950 				p1 = encode_entryplus_baggage(cd, p1, &fh);
951 		}
952 
953 		/* determine entry word length and lengths to go in pages */
954 		num_entry_words = p1 - tmp;
955 		len1 = curr_page_addr + PAGE_SIZE - (caddr_t)cd->buffer;
956 		if ((num_entry_words << 2) < len1) {
957 			/* the actual number of words in the entry is less
958 			 * than elen and can still fit in the current page
959 			 */
960 			memmove(p, tmp, num_entry_words << 2);
961 			p += num_entry_words;
962 
963 			/* update offset */
964 			cd->offset = cd->buffer + (cd->offset - tmp);
965 		} else {
966 			unsigned int offset_r = (cd->offset - tmp) << 2;
967 
968 			/* update pointer to offset location.
969 			 * This is a 64bit quantity, so we need to
970 			 * deal with 3 cases:
971 			 *  -	entirely in first page
972 			 *  -	entirely in second page
973 			 *  -	4 bytes in each page
974 			 */
975 			if (offset_r + 8 <= len1) {
976 				cd->offset = p + (cd->offset - tmp);
977 			} else if (offset_r >= len1) {
978 				cd->offset -= len1 >> 2;
979 			} else {
980 				/* sitting on the fence */
981 				BUG_ON(offset_r != len1 - 4);
982 				cd->offset = p + (cd->offset - tmp);
983 				cd->offset1 = tmp;
984 			}
985 
986 			len2 = (num_entry_words << 2) - len1;
987 
988 			/* move from temp page to current and next pages */
989 			memmove(p, tmp, len1);
990 			memmove(tmp, (caddr_t)tmp+len1, len2);
991 
992 			p = tmp + (len2 >> 2);
993 		}
994 	}
995 	else {
996 		cd->common.err = nfserr_toosmall;
997 		return -EINVAL;
998 	}
999 
1000 	cd->buflen -= num_entry_words;
1001 	cd->buffer = p;
1002 	cd->common.err = nfs_ok;
1003 	return 0;
1004 
1005 }
1006 
1007 int
1008 nfs3svc_encode_entry(void *cd, const char *name,
1009 		     int namlen, loff_t offset, u64 ino, unsigned int d_type)
1010 {
1011 	return encode_entry(cd, name, namlen, offset, ino, d_type, 0);
1012 }
1013 
1014 int
1015 nfs3svc_encode_entry_plus(void *cd, const char *name,
1016 			  int namlen, loff_t offset, u64 ino,
1017 			  unsigned int d_type)
1018 {
1019 	return encode_entry(cd, name, namlen, offset, ino, d_type, 1);
1020 }
1021 
1022 /* FSSTAT */
1023 int
1024 nfs3svc_encode_fsstatres(struct svc_rqst *rqstp, __be32 *p,
1025 					struct nfsd3_fsstatres *resp)
1026 {
1027 	struct kstatfs	*s = &resp->stats;
1028 	u64		bs = s->f_bsize;
1029 
1030 	*p++ = xdr_zero;	/* no post_op_attr */
1031 
1032 	if (resp->status == 0) {
1033 		p = xdr_encode_hyper(p, bs * s->f_blocks);	/* total bytes */
1034 		p = xdr_encode_hyper(p, bs * s->f_bfree);	/* free bytes */
1035 		p = xdr_encode_hyper(p, bs * s->f_bavail);	/* user available bytes */
1036 		p = xdr_encode_hyper(p, s->f_files);	/* total inodes */
1037 		p = xdr_encode_hyper(p, s->f_ffree);	/* free inodes */
1038 		p = xdr_encode_hyper(p, s->f_ffree);	/* user available inodes */
1039 		*p++ = htonl(resp->invarsec);	/* mean unchanged time */
1040 	}
1041 	return xdr_ressize_check(rqstp, p);
1042 }
1043 
1044 /* FSINFO */
1045 int
1046 nfs3svc_encode_fsinfores(struct svc_rqst *rqstp, __be32 *p,
1047 					struct nfsd3_fsinfores *resp)
1048 {
1049 	*p++ = xdr_zero;	/* no post_op_attr */
1050 
1051 	if (resp->status == 0) {
1052 		*p++ = htonl(resp->f_rtmax);
1053 		*p++ = htonl(resp->f_rtpref);
1054 		*p++ = htonl(resp->f_rtmult);
1055 		*p++ = htonl(resp->f_wtmax);
1056 		*p++ = htonl(resp->f_wtpref);
1057 		*p++ = htonl(resp->f_wtmult);
1058 		*p++ = htonl(resp->f_dtpref);
1059 		p = xdr_encode_hyper(p, resp->f_maxfilesize);
1060 		*p++ = xdr_one;
1061 		*p++ = xdr_zero;
1062 		*p++ = htonl(resp->f_properties);
1063 	}
1064 
1065 	return xdr_ressize_check(rqstp, p);
1066 }
1067 
1068 /* PATHCONF */
1069 int
1070 nfs3svc_encode_pathconfres(struct svc_rqst *rqstp, __be32 *p,
1071 					struct nfsd3_pathconfres *resp)
1072 {
1073 	*p++ = xdr_zero;	/* no post_op_attr */
1074 
1075 	if (resp->status == 0) {
1076 		*p++ = htonl(resp->p_link_max);
1077 		*p++ = htonl(resp->p_name_max);
1078 		*p++ = htonl(resp->p_no_trunc);
1079 		*p++ = htonl(resp->p_chown_restricted);
1080 		*p++ = htonl(resp->p_case_insensitive);
1081 		*p++ = htonl(resp->p_case_preserving);
1082 	}
1083 
1084 	return xdr_ressize_check(rqstp, p);
1085 }
1086 
1087 /* COMMIT */
1088 int
1089 nfs3svc_encode_commitres(struct svc_rqst *rqstp, __be32 *p,
1090 					struct nfsd3_commitres *resp)
1091 {
1092 	p = encode_wcc_data(rqstp, p, &resp->fh);
1093 	/* Write verifier */
1094 	if (resp->status == 0) {
1095 		*p++ = htonl(nfssvc_boot.tv_sec);
1096 		*p++ = htonl(nfssvc_boot.tv_usec);
1097 	}
1098 	return xdr_ressize_check(rqstp, p);
1099 }
1100 
1101 /*
1102  * XDR release functions
1103  */
1104 int
1105 nfs3svc_release_fhandle(struct svc_rqst *rqstp, __be32 *p,
1106 					struct nfsd3_attrstat *resp)
1107 {
1108 	fh_put(&resp->fh);
1109 	return 1;
1110 }
1111 
1112 int
1113 nfs3svc_release_fhandle2(struct svc_rqst *rqstp, __be32 *p,
1114 					struct nfsd3_fhandle_pair *resp)
1115 {
1116 	fh_put(&resp->fh1);
1117 	fh_put(&resp->fh2);
1118 	return 1;
1119 }
1120