xref: /linux/fs/nfsd/nfs3xdr.c (revision f3d9478b2ce468c3115b02ecae7e975990697f15)
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 #ifdef NFSD_OPTIMIZE_SPACE
28 # define inline
29 #endif
30 
31 
32 /*
33  * Mapping of S_IF* types to NFS file types
34  */
35 static u32	nfs3_ftypes[] = {
36 	NF3NON,  NF3FIFO, NF3CHR, NF3BAD,
37 	NF3DIR,  NF3BAD,  NF3BLK, NF3BAD,
38 	NF3REG,  NF3BAD,  NF3LNK, NF3BAD,
39 	NF3SOCK, NF3BAD,  NF3LNK, NF3BAD,
40 };
41 
42 /*
43  * XDR functions for basic NFS types
44  */
45 static inline u32 *
46 encode_time3(u32 *p, struct timespec *time)
47 {
48 	*p++ = htonl((u32) time->tv_sec); *p++ = htonl(time->tv_nsec);
49 	return p;
50 }
51 
52 static inline u32 *
53 decode_time3(u32 *p, struct timespec *time)
54 {
55 	time->tv_sec = ntohl(*p++);
56 	time->tv_nsec = ntohl(*p++);
57 	return p;
58 }
59 
60 static inline u32 *
61 decode_fh(u32 *p, struct svc_fh *fhp)
62 {
63 	unsigned int size;
64 	fh_init(fhp, NFS3_FHSIZE);
65 	size = ntohl(*p++);
66 	if (size > NFS3_FHSIZE)
67 		return NULL;
68 
69 	memcpy(&fhp->fh_handle.fh_base, p, size);
70 	fhp->fh_handle.fh_size = size;
71 	return p + XDR_QUADLEN(size);
72 }
73 
74 /* Helper function for NFSv3 ACL code */
75 u32 *nfs3svc_decode_fh(u32 *p, struct svc_fh *fhp)
76 {
77 	return decode_fh(p, fhp);
78 }
79 
80 static inline u32 *
81 encode_fh(u32 *p, struct svc_fh *fhp)
82 {
83 	unsigned int size = fhp->fh_handle.fh_size;
84 	*p++ = htonl(size);
85 	if (size) p[XDR_QUADLEN(size)-1]=0;
86 	memcpy(p, &fhp->fh_handle.fh_base, size);
87 	return p + XDR_QUADLEN(size);
88 }
89 
90 /*
91  * Decode a file name and make sure that the path contains
92  * no slashes or null bytes.
93  */
94 static inline u32 *
95 decode_filename(u32 *p, char **namp, int *lenp)
96 {
97 	char		*name;
98 	int		i;
99 
100 	if ((p = xdr_decode_string_inplace(p, namp, lenp, NFS3_MAXNAMLEN)) != NULL) {
101 		for (i = 0, name = *namp; i < *lenp; i++, name++) {
102 			if (*name == '\0' || *name == '/')
103 				return NULL;
104 		}
105 	}
106 
107 	return p;
108 }
109 
110 static inline u32 *
111 decode_sattr3(u32 *p, struct iattr *iap)
112 {
113 	u32	tmp;
114 
115 	iap->ia_valid = 0;
116 
117 	if (*p++) {
118 		iap->ia_valid |= ATTR_MODE;
119 		iap->ia_mode = ntohl(*p++);
120 	}
121 	if (*p++) {
122 		iap->ia_valid |= ATTR_UID;
123 		iap->ia_uid = ntohl(*p++);
124 	}
125 	if (*p++) {
126 		iap->ia_valid |= ATTR_GID;
127 		iap->ia_gid = ntohl(*p++);
128 	}
129 	if (*p++) {
130 		u64	newsize;
131 
132 		iap->ia_valid |= ATTR_SIZE;
133 		p = xdr_decode_hyper(p, &newsize);
134 		if (newsize <= NFS_OFFSET_MAX)
135 			iap->ia_size = newsize;
136 		else
137 			iap->ia_size = NFS_OFFSET_MAX;
138 	}
139 	if ((tmp = ntohl(*p++)) == 1) {	/* set to server time */
140 		iap->ia_valid |= ATTR_ATIME;
141 	} else if (tmp == 2) {		/* set to client time */
142 		iap->ia_valid |= ATTR_ATIME | ATTR_ATIME_SET;
143 		iap->ia_atime.tv_sec = ntohl(*p++);
144 		iap->ia_atime.tv_nsec = ntohl(*p++);
145 	}
146 	if ((tmp = ntohl(*p++)) == 1) {	/* set to server time */
147 		iap->ia_valid |= ATTR_MTIME;
148 	} else if (tmp == 2) {		/* set to client time */
149 		iap->ia_valid |= ATTR_MTIME | ATTR_MTIME_SET;
150 		iap->ia_mtime.tv_sec = ntohl(*p++);
151 		iap->ia_mtime.tv_nsec = ntohl(*p++);
152 	}
153 	return p;
154 }
155 
156 static inline u32 *
157 encode_fattr3(struct svc_rqst *rqstp, u32 *p, struct svc_fh *fhp,
158 	      struct kstat *stat)
159 {
160 	struct dentry	*dentry = fhp->fh_dentry;
161 	struct timespec time;
162 
163 	*p++ = htonl(nfs3_ftypes[(stat->mode & S_IFMT) >> 12]);
164 	*p++ = htonl((u32) stat->mode);
165 	*p++ = htonl((u32) stat->nlink);
166 	*p++ = htonl((u32) nfsd_ruid(rqstp, stat->uid));
167 	*p++ = htonl((u32) nfsd_rgid(rqstp, stat->gid));
168 	if (S_ISLNK(stat->mode) && stat->size > NFS3_MAXPATHLEN) {
169 		p = xdr_encode_hyper(p, (u64) NFS3_MAXPATHLEN);
170 	} else {
171 		p = xdr_encode_hyper(p, (u64) stat->size);
172 	}
173 	p = xdr_encode_hyper(p, ((u64)stat->blocks) << 9);
174 	*p++ = htonl((u32) MAJOR(stat->rdev));
175 	*p++ = htonl((u32) MINOR(stat->rdev));
176 	if (is_fsid(fhp, rqstp->rq_reffh))
177 		p = xdr_encode_hyper(p, (u64) fhp->fh_export->ex_fsid);
178 	else
179 		p = xdr_encode_hyper(p, (u64) huge_encode_dev(stat->dev));
180 	p = xdr_encode_hyper(p, (u64) stat->ino);
181 	p = encode_time3(p, &stat->atime);
182 	lease_get_mtime(dentry->d_inode, &time);
183 	p = encode_time3(p, &time);
184 	p = encode_time3(p, &stat->ctime);
185 
186 	return p;
187 }
188 
189 static inline u32 *
190 encode_saved_post_attr(struct svc_rqst *rqstp, u32 *p, struct svc_fh *fhp)
191 {
192 	struct inode	*inode = fhp->fh_dentry->d_inode;
193 
194 	/* Attributes to follow */
195 	*p++ = xdr_one;
196 
197 	*p++ = htonl(nfs3_ftypes[(fhp->fh_post_mode & S_IFMT) >> 12]);
198 	*p++ = htonl((u32) fhp->fh_post_mode);
199 	*p++ = htonl((u32) fhp->fh_post_nlink);
200 	*p++ = htonl((u32) nfsd_ruid(rqstp, fhp->fh_post_uid));
201 	*p++ = htonl((u32) nfsd_rgid(rqstp, fhp->fh_post_gid));
202 	if (S_ISLNK(fhp->fh_post_mode) && fhp->fh_post_size > NFS3_MAXPATHLEN) {
203 		p = xdr_encode_hyper(p, (u64) NFS3_MAXPATHLEN);
204 	} else {
205 		p = xdr_encode_hyper(p, (u64) fhp->fh_post_size);
206 	}
207 	p = xdr_encode_hyper(p, ((u64)fhp->fh_post_blocks) << 9);
208 	*p++ = fhp->fh_post_rdev[0];
209 	*p++ = fhp->fh_post_rdev[1];
210 	if (is_fsid(fhp, rqstp->rq_reffh))
211 		p = xdr_encode_hyper(p, (u64) fhp->fh_export->ex_fsid);
212 	else
213 		p = xdr_encode_hyper(p, (u64)huge_encode_dev(inode->i_sb->s_dev));
214 	p = xdr_encode_hyper(p, (u64) inode->i_ino);
215 	p = encode_time3(p, &fhp->fh_post_atime);
216 	p = encode_time3(p, &fhp->fh_post_mtime);
217 	p = encode_time3(p, &fhp->fh_post_ctime);
218 
219 	return p;
220 }
221 
222 /*
223  * Encode post-operation attributes.
224  * The inode may be NULL if the call failed because of a stale file
225  * handle. In this case, no attributes are returned.
226  */
227 static u32 *
228 encode_post_op_attr(struct svc_rqst *rqstp, u32 *p, struct svc_fh *fhp)
229 {
230 	struct dentry *dentry = fhp->fh_dentry;
231 	if (dentry && dentry->d_inode != NULL) {
232 	        int err;
233 		struct kstat stat;
234 
235 		err = vfs_getattr(fhp->fh_export->ex_mnt, dentry, &stat);
236 		if (!err) {
237 			*p++ = xdr_one;		/* attributes follow */
238 			return encode_fattr3(rqstp, p, fhp, &stat);
239 		}
240 	}
241 	*p++ = xdr_zero;
242 	return p;
243 }
244 
245 /* Helper for NFSv3 ACLs */
246 u32 *
247 nfs3svc_encode_post_op_attr(struct svc_rqst *rqstp, u32 *p, struct svc_fh *fhp)
248 {
249 	return encode_post_op_attr(rqstp, p, fhp);
250 }
251 
252 /*
253  * Enocde weak cache consistency data
254  */
255 static u32 *
256 encode_wcc_data(struct svc_rqst *rqstp, u32 *p, struct svc_fh *fhp)
257 {
258 	struct dentry	*dentry = fhp->fh_dentry;
259 
260 	if (dentry && dentry->d_inode && fhp->fh_post_saved) {
261 		if (fhp->fh_pre_saved) {
262 			*p++ = xdr_one;
263 			p = xdr_encode_hyper(p, (u64) fhp->fh_pre_size);
264 			p = encode_time3(p, &fhp->fh_pre_mtime);
265 			p = encode_time3(p, &fhp->fh_pre_ctime);
266 		} else {
267 			*p++ = xdr_zero;
268 		}
269 		return encode_saved_post_attr(rqstp, p, fhp);
270 	}
271 	/* no pre- or post-attrs */
272 	*p++ = xdr_zero;
273 	return encode_post_op_attr(rqstp, p, fhp);
274 }
275 
276 
277 /*
278  * XDR decode functions
279  */
280 int
281 nfs3svc_decode_fhandle(struct svc_rqst *rqstp, u32 *p, struct nfsd_fhandle *args)
282 {
283 	if (!(p = decode_fh(p, &args->fh)))
284 		return 0;
285 	return xdr_argsize_check(rqstp, p);
286 }
287 
288 int
289 nfs3svc_decode_sattrargs(struct svc_rqst *rqstp, u32 *p,
290 					struct nfsd3_sattrargs *args)
291 {
292 	if (!(p = decode_fh(p, &args->fh))
293 	 || !(p = decode_sattr3(p, &args->attrs)))
294 		return 0;
295 
296 	if ((args->check_guard = ntohl(*p++)) != 0) {
297 		struct timespec time;
298 		p = decode_time3(p, &time);
299 		args->guardtime = time.tv_sec;
300 	}
301 
302 	return xdr_argsize_check(rqstp, p);
303 }
304 
305 int
306 nfs3svc_decode_diropargs(struct svc_rqst *rqstp, u32 *p,
307 					struct nfsd3_diropargs *args)
308 {
309 	if (!(p = decode_fh(p, &args->fh))
310 	 || !(p = decode_filename(p, &args->name, &args->len)))
311 		return 0;
312 
313 	return xdr_argsize_check(rqstp, p);
314 }
315 
316 int
317 nfs3svc_decode_accessargs(struct svc_rqst *rqstp, u32 *p,
318 					struct nfsd3_accessargs *args)
319 {
320 	if (!(p = decode_fh(p, &args->fh)))
321 		return 0;
322 	args->access = ntohl(*p++);
323 
324 	return xdr_argsize_check(rqstp, p);
325 }
326 
327 int
328 nfs3svc_decode_readargs(struct svc_rqst *rqstp, u32 *p,
329 					struct nfsd3_readargs *args)
330 {
331 	unsigned int len;
332 	int v,pn;
333 
334 	if (!(p = decode_fh(p, &args->fh))
335 	 || !(p = xdr_decode_hyper(p, &args->offset)))
336 		return 0;
337 
338 	len = args->count = ntohl(*p++);
339 
340 	if (len > NFSSVC_MAXBLKSIZE)
341 		len = NFSSVC_MAXBLKSIZE;
342 
343 	/* set up the kvec */
344 	v=0;
345 	while (len > 0) {
346 		pn = rqstp->rq_resused;
347 		svc_take_page(rqstp);
348 		args->vec[v].iov_base = page_address(rqstp->rq_respages[pn]);
349 		args->vec[v].iov_len = len < PAGE_SIZE? len : PAGE_SIZE;
350 		len -= args->vec[v].iov_len;
351 		v++;
352 	}
353 	args->vlen = v;
354 	return xdr_argsize_check(rqstp, p);
355 }
356 
357 int
358 nfs3svc_decode_writeargs(struct svc_rqst *rqstp, u32 *p,
359 					struct nfsd3_writeargs *args)
360 {
361 	unsigned int len, v, hdr;
362 
363 	if (!(p = decode_fh(p, &args->fh))
364 	 || !(p = xdr_decode_hyper(p, &args->offset)))
365 		return 0;
366 
367 	args->count = ntohl(*p++);
368 	args->stable = ntohl(*p++);
369 	len = args->len = ntohl(*p++);
370 
371 	hdr = (void*)p - rqstp->rq_arg.head[0].iov_base;
372 	if (rqstp->rq_arg.len < hdr ||
373 	    rqstp->rq_arg.len - hdr < len)
374 		return 0;
375 
376 	args->vec[0].iov_base = (void*)p;
377 	args->vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr;
378 
379 	if (len > NFSSVC_MAXBLKSIZE)
380 		len = NFSSVC_MAXBLKSIZE;
381 	v=  0;
382 	while (len > args->vec[v].iov_len) {
383 		len -= args->vec[v].iov_len;
384 		v++;
385 		args->vec[v].iov_base = page_address(rqstp->rq_argpages[v]);
386 		args->vec[v].iov_len = PAGE_SIZE;
387 	}
388 	args->vec[v].iov_len = len;
389 	args->vlen = v+1;
390 
391 	return args->count == args->len && args->vec[0].iov_len > 0;
392 }
393 
394 int
395 nfs3svc_decode_createargs(struct svc_rqst *rqstp, u32 *p,
396 					struct nfsd3_createargs *args)
397 {
398 	if (!(p = decode_fh(p, &args->fh))
399 	 || !(p = decode_filename(p, &args->name, &args->len)))
400 		return 0;
401 
402 	switch (args->createmode = ntohl(*p++)) {
403 	case NFS3_CREATE_UNCHECKED:
404 	case NFS3_CREATE_GUARDED:
405 		if (!(p = decode_sattr3(p, &args->attrs)))
406 			return 0;
407 		break;
408 	case NFS3_CREATE_EXCLUSIVE:
409 		args->verf = p;
410 		p += 2;
411 		break;
412 	default:
413 		return 0;
414 	}
415 
416 	return xdr_argsize_check(rqstp, p);
417 }
418 int
419 nfs3svc_decode_mkdirargs(struct svc_rqst *rqstp, u32 *p,
420 					struct nfsd3_createargs *args)
421 {
422 	if (!(p = decode_fh(p, &args->fh))
423 	 || !(p = decode_filename(p, &args->name, &args->len))
424 	 || !(p = decode_sattr3(p, &args->attrs)))
425 		return 0;
426 
427 	return xdr_argsize_check(rqstp, p);
428 }
429 
430 int
431 nfs3svc_decode_symlinkargs(struct svc_rqst *rqstp, u32 *p,
432 					struct nfsd3_symlinkargs *args)
433 {
434 	unsigned int len;
435 	int avail;
436 	char *old, *new;
437 	struct kvec *vec;
438 
439 	if (!(p = decode_fh(p, &args->ffh))
440 	 || !(p = decode_filename(p, &args->fname, &args->flen))
441 	 || !(p = decode_sattr3(p, &args->attrs))
442 		)
443 		return 0;
444 	/* now decode the pathname, which might be larger than the first page.
445 	 * As we have to check for nul's anyway, we copy it into a new page
446 	 * This page appears in the rq_res.pages list, but as pages_len is always
447 	 * 0, it won't get in the way
448 	 */
449 	svc_take_page(rqstp);
450 	len = ntohl(*p++);
451 	if (len == 0 || len > NFS3_MAXPATHLEN || len >= PAGE_SIZE)
452 		return 0;
453 	args->tname = new = page_address(rqstp->rq_respages[rqstp->rq_resused-1]);
454 	args->tlen = len;
455 	/* first copy and check from the first page */
456 	old = (char*)p;
457 	vec = &rqstp->rq_arg.head[0];
458 	avail = vec->iov_len - (old - (char*)vec->iov_base);
459 	while (len && avail && *old) {
460 		*new++ = *old++;
461 		len--;
462 		avail--;
463 	}
464 	/* now copy next page if there is one */
465 	if (len && !avail && rqstp->rq_arg.page_len) {
466 		avail = rqstp->rq_arg.page_len;
467 		if (avail > PAGE_SIZE) avail = PAGE_SIZE;
468 		old = page_address(rqstp->rq_arg.pages[0]);
469 	}
470 	while (len && avail && *old) {
471 		*new++ = *old++;
472 		len--;
473 		avail--;
474 	}
475 	*new = '\0';
476 	if (len)
477 		return 0;
478 
479 	return 1;
480 }
481 
482 int
483 nfs3svc_decode_mknodargs(struct svc_rqst *rqstp, u32 *p,
484 					struct nfsd3_mknodargs *args)
485 {
486 	if (!(p = decode_fh(p, &args->fh))
487 	 || !(p = decode_filename(p, &args->name, &args->len)))
488 		return 0;
489 
490 	args->ftype = ntohl(*p++);
491 
492 	if (args->ftype == NF3BLK  || args->ftype == NF3CHR
493 	 || args->ftype == NF3SOCK || args->ftype == NF3FIFO) {
494 		if (!(p = decode_sattr3(p, &args->attrs)))
495 			return 0;
496 	}
497 
498 	if (args->ftype == NF3BLK || args->ftype == NF3CHR) {
499 		args->major = ntohl(*p++);
500 		args->minor = ntohl(*p++);
501 	}
502 
503 	return xdr_argsize_check(rqstp, p);
504 }
505 
506 int
507 nfs3svc_decode_renameargs(struct svc_rqst *rqstp, u32 *p,
508 					struct nfsd3_renameargs *args)
509 {
510 	if (!(p = decode_fh(p, &args->ffh))
511 	 || !(p = decode_filename(p, &args->fname, &args->flen))
512 	 || !(p = decode_fh(p, &args->tfh))
513 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
514 		return 0;
515 
516 	return xdr_argsize_check(rqstp, p);
517 }
518 
519 int
520 nfs3svc_decode_readlinkargs(struct svc_rqst *rqstp, u32 *p,
521 					struct nfsd3_readlinkargs *args)
522 {
523 	if (!(p = decode_fh(p, &args->fh)))
524 		return 0;
525 	svc_take_page(rqstp);
526 	args->buffer = page_address(rqstp->rq_respages[rqstp->rq_resused-1]);
527 
528 	return xdr_argsize_check(rqstp, p);
529 }
530 
531 int
532 nfs3svc_decode_linkargs(struct svc_rqst *rqstp, u32 *p,
533 					struct nfsd3_linkargs *args)
534 {
535 	if (!(p = decode_fh(p, &args->ffh))
536 	 || !(p = decode_fh(p, &args->tfh))
537 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
538 		return 0;
539 
540 	return xdr_argsize_check(rqstp, p);
541 }
542 
543 int
544 nfs3svc_decode_readdirargs(struct svc_rqst *rqstp, u32 *p,
545 					struct nfsd3_readdirargs *args)
546 {
547 	if (!(p = decode_fh(p, &args->fh)))
548 		return 0;
549 	p = xdr_decode_hyper(p, &args->cookie);
550 	args->verf   = p; p += 2;
551 	args->dircount = ~0;
552 	args->count  = ntohl(*p++);
553 
554 	if (args->count > PAGE_SIZE)
555 		args->count = PAGE_SIZE;
556 
557 	svc_take_page(rqstp);
558 	args->buffer = page_address(rqstp->rq_respages[rqstp->rq_resused-1]);
559 
560 	return xdr_argsize_check(rqstp, p);
561 }
562 
563 int
564 nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, u32 *p,
565 					struct nfsd3_readdirargs *args)
566 {
567 	int len, pn;
568 
569 	if (!(p = decode_fh(p, &args->fh)))
570 		return 0;
571 	p = xdr_decode_hyper(p, &args->cookie);
572 	args->verf     = p; p += 2;
573 	args->dircount = ntohl(*p++);
574 	args->count    = ntohl(*p++);
575 
576 	len = (args->count > NFSSVC_MAXBLKSIZE) ? NFSSVC_MAXBLKSIZE :
577 						  args->count;
578 	args->count = len;
579 
580 	while (len > 0) {
581 		pn = rqstp->rq_resused;
582 		svc_take_page(rqstp);
583 		if (!args->buffer)
584 			args->buffer = page_address(rqstp->rq_respages[pn]);
585 		len -= PAGE_SIZE;
586 	}
587 
588 	return xdr_argsize_check(rqstp, p);
589 }
590 
591 int
592 nfs3svc_decode_commitargs(struct svc_rqst *rqstp, u32 *p,
593 					struct nfsd3_commitargs *args)
594 {
595 	if (!(p = decode_fh(p, &args->fh)))
596 		return 0;
597 	p = xdr_decode_hyper(p, &args->offset);
598 	args->count = ntohl(*p++);
599 
600 	return xdr_argsize_check(rqstp, p);
601 }
602 
603 /*
604  * XDR encode functions
605  */
606 /*
607  * There must be an encoding function for void results so svc_process
608  * will work properly.
609  */
610 int
611 nfs3svc_encode_voidres(struct svc_rqst *rqstp, u32 *p, void *dummy)
612 {
613 	return xdr_ressize_check(rqstp, p);
614 }
615 
616 /* GETATTR */
617 int
618 nfs3svc_encode_attrstat(struct svc_rqst *rqstp, u32 *p,
619 					struct nfsd3_attrstat *resp)
620 {
621 	if (resp->status == 0)
622 		p = encode_fattr3(rqstp, p, &resp->fh, &resp->stat);
623 	return xdr_ressize_check(rqstp, p);
624 }
625 
626 /* SETATTR, REMOVE, RMDIR */
627 int
628 nfs3svc_encode_wccstat(struct svc_rqst *rqstp, u32 *p,
629 					struct nfsd3_attrstat *resp)
630 {
631 	p = encode_wcc_data(rqstp, p, &resp->fh);
632 	return xdr_ressize_check(rqstp, p);
633 }
634 
635 /* LOOKUP */
636 int
637 nfs3svc_encode_diropres(struct svc_rqst *rqstp, u32 *p,
638 					struct nfsd3_diropres *resp)
639 {
640 	if (resp->status == 0) {
641 		p = encode_fh(p, &resp->fh);
642 		p = encode_post_op_attr(rqstp, p, &resp->fh);
643 	}
644 	p = encode_post_op_attr(rqstp, p, &resp->dirfh);
645 	return xdr_ressize_check(rqstp, p);
646 }
647 
648 /* ACCESS */
649 int
650 nfs3svc_encode_accessres(struct svc_rqst *rqstp, u32 *p,
651 					struct nfsd3_accessres *resp)
652 {
653 	p = encode_post_op_attr(rqstp, p, &resp->fh);
654 	if (resp->status == 0)
655 		*p++ = htonl(resp->access);
656 	return xdr_ressize_check(rqstp, p);
657 }
658 
659 /* READLINK */
660 int
661 nfs3svc_encode_readlinkres(struct svc_rqst *rqstp, u32 *p,
662 					struct nfsd3_readlinkres *resp)
663 {
664 	p = encode_post_op_attr(rqstp, p, &resp->fh);
665 	if (resp->status == 0) {
666 		*p++ = htonl(resp->len);
667 		xdr_ressize_check(rqstp, p);
668 		rqstp->rq_res.page_len = resp->len;
669 		if (resp->len & 3) {
670 			/* need to pad the tail */
671 			rqstp->rq_restailpage = 0;
672 			rqstp->rq_res.tail[0].iov_base = p;
673 			*p = 0;
674 			rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
675 		}
676 		return 1;
677 	} else
678 		return xdr_ressize_check(rqstp, p);
679 }
680 
681 /* READ */
682 int
683 nfs3svc_encode_readres(struct svc_rqst *rqstp, u32 *p,
684 					struct nfsd3_readres *resp)
685 {
686 	p = encode_post_op_attr(rqstp, p, &resp->fh);
687 	if (resp->status == 0) {
688 		*p++ = htonl(resp->count);
689 		*p++ = htonl(resp->eof);
690 		*p++ = htonl(resp->count);	/* xdr opaque count */
691 		xdr_ressize_check(rqstp, p);
692 		/* now update rqstp->rq_res to reflect data aswell */
693 		rqstp->rq_res.page_len = resp->count;
694 		if (resp->count & 3) {
695 			/* need to pad the tail */
696 			rqstp->rq_restailpage = 0;
697 			rqstp->rq_res.tail[0].iov_base = p;
698 			*p = 0;
699 			rqstp->rq_res.tail[0].iov_len = 4 - (resp->count & 3);
700 		}
701 		return 1;
702 	} else
703 		return xdr_ressize_check(rqstp, p);
704 }
705 
706 /* WRITE */
707 int
708 nfs3svc_encode_writeres(struct svc_rqst *rqstp, u32 *p,
709 					struct nfsd3_writeres *resp)
710 {
711 	p = encode_wcc_data(rqstp, p, &resp->fh);
712 	if (resp->status == 0) {
713 		*p++ = htonl(resp->count);
714 		*p++ = htonl(resp->committed);
715 		*p++ = htonl(nfssvc_boot.tv_sec);
716 		*p++ = htonl(nfssvc_boot.tv_usec);
717 	}
718 	return xdr_ressize_check(rqstp, p);
719 }
720 
721 /* CREATE, MKDIR, SYMLINK, MKNOD */
722 int
723 nfs3svc_encode_createres(struct svc_rqst *rqstp, u32 *p,
724 					struct nfsd3_diropres *resp)
725 {
726 	if (resp->status == 0) {
727 		*p++ = xdr_one;
728 		p = encode_fh(p, &resp->fh);
729 		p = encode_post_op_attr(rqstp, p, &resp->fh);
730 	}
731 	p = encode_wcc_data(rqstp, p, &resp->dirfh);
732 	return xdr_ressize_check(rqstp, p);
733 }
734 
735 /* RENAME */
736 int
737 nfs3svc_encode_renameres(struct svc_rqst *rqstp, u32 *p,
738 					struct nfsd3_renameres *resp)
739 {
740 	p = encode_wcc_data(rqstp, p, &resp->ffh);
741 	p = encode_wcc_data(rqstp, p, &resp->tfh);
742 	return xdr_ressize_check(rqstp, p);
743 }
744 
745 /* LINK */
746 int
747 nfs3svc_encode_linkres(struct svc_rqst *rqstp, u32 *p,
748 					struct nfsd3_linkres *resp)
749 {
750 	p = encode_post_op_attr(rqstp, p, &resp->fh);
751 	p = encode_wcc_data(rqstp, p, &resp->tfh);
752 	return xdr_ressize_check(rqstp, p);
753 }
754 
755 /* READDIR */
756 int
757 nfs3svc_encode_readdirres(struct svc_rqst *rqstp, u32 *p,
758 					struct nfsd3_readdirres *resp)
759 {
760 	p = encode_post_op_attr(rqstp, p, &resp->fh);
761 
762 	if (resp->status == 0) {
763 		/* stupid readdir cookie */
764 		memcpy(p, resp->verf, 8); p += 2;
765 		xdr_ressize_check(rqstp, p);
766 		if (rqstp->rq_res.head[0].iov_len + (2<<2) > PAGE_SIZE)
767 			return 1; /*No room for trailer */
768 		rqstp->rq_res.page_len = (resp->count) << 2;
769 
770 		/* add the 'tail' to the end of the 'head' page - page 0. */
771 		rqstp->rq_restailpage = 0;
772 		rqstp->rq_res.tail[0].iov_base = p;
773 		*p++ = 0;		/* no more entries */
774 		*p++ = htonl(resp->common.err == nfserr_eof);
775 		rqstp->rq_res.tail[0].iov_len = 2<<2;
776 		return 1;
777 	} else
778 		return xdr_ressize_check(rqstp, p);
779 }
780 
781 static inline u32 *
782 encode_entry_baggage(struct nfsd3_readdirres *cd, u32 *p, const char *name,
783 	     int namlen, ino_t ino)
784 {
785 	*p++ = xdr_one;				 /* mark entry present */
786 	p    = xdr_encode_hyper(p, ino);	 /* file id */
787 	p    = xdr_encode_array(p, name, namlen);/* name length & name */
788 
789 	cd->offset = p;				/* remember pointer */
790 	p = xdr_encode_hyper(p, NFS_OFFSET_MAX);/* offset of next entry */
791 
792 	return p;
793 }
794 
795 static inline u32 *
796 encode_entryplus_baggage(struct nfsd3_readdirres *cd, u32 *p,
797 		struct svc_fh *fhp)
798 {
799 		p = encode_post_op_attr(cd->rqstp, p, fhp);
800 		*p++ = xdr_one;			/* yes, a file handle follows */
801 		p = encode_fh(p, fhp);
802 		fh_put(fhp);
803 		return p;
804 }
805 
806 static int
807 compose_entry_fh(struct nfsd3_readdirres *cd, struct svc_fh *fhp,
808 		const char *name, int namlen)
809 {
810 	struct svc_export	*exp;
811 	struct dentry		*dparent, *dchild;
812 	int rv = 0;
813 
814 	dparent = cd->fh.fh_dentry;
815 	exp  = cd->fh.fh_export;
816 
817 	fh_init(fhp, NFS3_FHSIZE);
818 	if (isdotent(name, namlen)) {
819 		if (namlen == 2) {
820 			dchild = dget_parent(dparent);
821 			if (dchild == dparent) {
822 				/* filesystem root - cannot return filehandle for ".." */
823 				dput(dchild);
824 				return 1;
825 			}
826 		} else
827 			dchild = dget(dparent);
828 	} else
829 		dchild = lookup_one_len(name, dparent, namlen);
830 	if (IS_ERR(dchild))
831 		return 1;
832 	if (d_mountpoint(dchild) ||
833 	    fh_compose(fhp, exp, dchild, &cd->fh) != 0 ||
834 	    !dchild->d_inode)
835 		rv = 1;
836 	dput(dchild);
837 	return rv;
838 }
839 
840 /*
841  * Encode a directory entry. This one works for both normal readdir
842  * and readdirplus.
843  * The normal readdir reply requires 2 (fileid) + 1 (stringlen)
844  * + string + 2 (cookie) + 1 (next) words, i.e. 6 + strlen.
845  *
846  * The readdirplus baggage is 1+21 words for post_op_attr, plus the
847  * file handle.
848  */
849 
850 #define NFS3_ENTRY_BAGGAGE	(2 + 1 + 2 + 1)
851 #define NFS3_ENTRYPLUS_BAGGAGE	(1 + 21 + 1 + (NFS3_FHSIZE >> 2))
852 static int
853 encode_entry(struct readdir_cd *ccd, const char *name,
854 	     int namlen, off_t offset, ino_t ino, unsigned int d_type, int plus)
855 {
856 	struct nfsd3_readdirres *cd = container_of(ccd, struct nfsd3_readdirres,
857 		       					common);
858 	u32		*p = cd->buffer;
859 	caddr_t		curr_page_addr = NULL;
860 	int		pn;		/* current page number */
861 	int		slen;		/* string (name) length */
862 	int		elen;		/* estimated entry length in words */
863 	int		num_entry_words = 0;	/* actual number of words */
864 
865 	if (cd->offset) {
866 		u64 offset64 = offset;
867 
868 		if (unlikely(cd->offset1)) {
869 			/* we ended up with offset on a page boundary */
870 			*cd->offset = htonl(offset64 >> 32);
871 			*cd->offset1 = htonl(offset64 & 0xffffffff);
872 			cd->offset1 = NULL;
873 		} else {
874 			xdr_encode_hyper(cd->offset, (u64) offset);
875 		}
876 	}
877 
878 	/*
879 	dprintk("encode_entry(%.*s @%ld%s)\n",
880 		namlen, name, (long) offset, plus? " plus" : "");
881 	 */
882 
883 	/* truncate filename if too long */
884 	if (namlen > NFS3_MAXNAMLEN)
885 		namlen = NFS3_MAXNAMLEN;
886 
887 	slen = XDR_QUADLEN(namlen);
888 	elen = slen + NFS3_ENTRY_BAGGAGE
889 		+ (plus? NFS3_ENTRYPLUS_BAGGAGE : 0);
890 
891 	if (cd->buflen < elen) {
892 		cd->common.err = nfserr_toosmall;
893 		return -EINVAL;
894 	}
895 
896 	/* determine which page in rq_respages[] we are currently filling */
897 	for (pn=1; pn < cd->rqstp->rq_resused; pn++) {
898 		curr_page_addr = page_address(cd->rqstp->rq_respages[pn]);
899 
900 		if (((caddr_t)cd->buffer >= curr_page_addr) &&
901 		    ((caddr_t)cd->buffer <  curr_page_addr + PAGE_SIZE))
902 			break;
903 	}
904 
905 	if ((caddr_t)(cd->buffer + elen) < (curr_page_addr + PAGE_SIZE)) {
906 		/* encode entry in current page */
907 
908 		p = encode_entry_baggage(cd, p, name, namlen, ino);
909 
910 		/* throw in readdirplus baggage */
911 		if (plus) {
912 			struct svc_fh	fh;
913 
914 			if (compose_entry_fh(cd, &fh, name, namlen) > 0) {
915 				*p++ = 0;
916 				*p++ = 0;
917 			} else
918 				p = encode_entryplus_baggage(cd, p, &fh);
919 		}
920 		num_entry_words = p - cd->buffer;
921 	} else if (cd->rqstp->rq_respages[pn+1] != NULL) {
922 		/* temporarily encode entry into next page, then move back to
923 		 * current and next page in rq_respages[] */
924 		u32 *p1, *tmp;
925 		int len1, len2;
926 
927 		/* grab next page for temporary storage of entry */
928 		p1 = tmp = page_address(cd->rqstp->rq_respages[pn+1]);
929 
930 		p1 = encode_entry_baggage(cd, p1, name, namlen, ino);
931 
932 		/* throw in readdirplus baggage */
933 		if (plus) {
934 			struct svc_fh	fh;
935 
936 			if (compose_entry_fh(cd, &fh, name, namlen) > 0) {
937 				/* zero out the filehandle */
938 				*p1++ = 0;
939 				*p1++ = 0;
940 			} else
941 				p1 = encode_entryplus_baggage(cd, p1, &fh);
942 		}
943 
944 		/* determine entry word length and lengths to go in pages */
945 		num_entry_words = p1 - tmp;
946 		len1 = curr_page_addr + PAGE_SIZE - (caddr_t)cd->buffer;
947 		if ((num_entry_words << 2) < len1) {
948 			/* the actual number of words in the entry is less
949 			 * than elen and can still fit in the current page
950 			 */
951 			memmove(p, tmp, num_entry_words << 2);
952 			p += num_entry_words;
953 
954 			/* update offset */
955 			cd->offset = cd->buffer + (cd->offset - tmp);
956 		} else {
957 			unsigned int offset_r = (cd->offset - tmp) << 2;
958 
959 			/* update pointer to offset location.
960 			 * This is a 64bit quantity, so we need to
961 			 * deal with 3 cases:
962 			 *  -	entirely in first page
963 			 *  -	entirely in second page
964 			 *  -	4 bytes in each page
965 			 */
966 			if (offset_r + 8 <= len1) {
967 				cd->offset = p + (cd->offset - tmp);
968 			} else if (offset_r >= len1) {
969 				cd->offset -= len1 >> 2;
970 			} else {
971 				/* sitting on the fence */
972 				BUG_ON(offset_r != len1 - 4);
973 				cd->offset = p + (cd->offset - tmp);
974 				cd->offset1 = tmp;
975 			}
976 
977 			len2 = (num_entry_words << 2) - len1;
978 
979 			/* move from temp page to current and next pages */
980 			memmove(p, tmp, len1);
981 			memmove(tmp, (caddr_t)tmp+len1, len2);
982 
983 			p = tmp + (len2 >> 2);
984 		}
985 	}
986 	else {
987 		cd->common.err = nfserr_toosmall;
988 		return -EINVAL;
989 	}
990 
991 	cd->buflen -= num_entry_words;
992 	cd->buffer = p;
993 	cd->common.err = nfs_ok;
994 	return 0;
995 
996 }
997 
998 int
999 nfs3svc_encode_entry(struct readdir_cd *cd, const char *name,
1000 		     int namlen, loff_t offset, ino_t ino, unsigned int d_type)
1001 {
1002 	return encode_entry(cd, name, namlen, offset, ino, d_type, 0);
1003 }
1004 
1005 int
1006 nfs3svc_encode_entry_plus(struct readdir_cd *cd, const char *name,
1007 			  int namlen, loff_t offset, ino_t ino, unsigned int d_type)
1008 {
1009 	return encode_entry(cd, name, namlen, offset, ino, d_type, 1);
1010 }
1011 
1012 /* FSSTAT */
1013 int
1014 nfs3svc_encode_fsstatres(struct svc_rqst *rqstp, u32 *p,
1015 					struct nfsd3_fsstatres *resp)
1016 {
1017 	struct kstatfs	*s = &resp->stats;
1018 	u64		bs = s->f_bsize;
1019 
1020 	*p++ = xdr_zero;	/* no post_op_attr */
1021 
1022 	if (resp->status == 0) {
1023 		p = xdr_encode_hyper(p, bs * s->f_blocks);	/* total bytes */
1024 		p = xdr_encode_hyper(p, bs * s->f_bfree);	/* free bytes */
1025 		p = xdr_encode_hyper(p, bs * s->f_bavail);	/* user available bytes */
1026 		p = xdr_encode_hyper(p, s->f_files);	/* total inodes */
1027 		p = xdr_encode_hyper(p, s->f_ffree);	/* free inodes */
1028 		p = xdr_encode_hyper(p, s->f_ffree);	/* user available inodes */
1029 		*p++ = htonl(resp->invarsec);	/* mean unchanged time */
1030 	}
1031 	return xdr_ressize_check(rqstp, p);
1032 }
1033 
1034 /* FSINFO */
1035 int
1036 nfs3svc_encode_fsinfores(struct svc_rqst *rqstp, u32 *p,
1037 					struct nfsd3_fsinfores *resp)
1038 {
1039 	*p++ = xdr_zero;	/* no post_op_attr */
1040 
1041 	if (resp->status == 0) {
1042 		*p++ = htonl(resp->f_rtmax);
1043 		*p++ = htonl(resp->f_rtpref);
1044 		*p++ = htonl(resp->f_rtmult);
1045 		*p++ = htonl(resp->f_wtmax);
1046 		*p++ = htonl(resp->f_wtpref);
1047 		*p++ = htonl(resp->f_wtmult);
1048 		*p++ = htonl(resp->f_dtpref);
1049 		p = xdr_encode_hyper(p, resp->f_maxfilesize);
1050 		*p++ = xdr_one;
1051 		*p++ = xdr_zero;
1052 		*p++ = htonl(resp->f_properties);
1053 	}
1054 
1055 	return xdr_ressize_check(rqstp, p);
1056 }
1057 
1058 /* PATHCONF */
1059 int
1060 nfs3svc_encode_pathconfres(struct svc_rqst *rqstp, u32 *p,
1061 					struct nfsd3_pathconfres *resp)
1062 {
1063 	*p++ = xdr_zero;	/* no post_op_attr */
1064 
1065 	if (resp->status == 0) {
1066 		*p++ = htonl(resp->p_link_max);
1067 		*p++ = htonl(resp->p_name_max);
1068 		*p++ = htonl(resp->p_no_trunc);
1069 		*p++ = htonl(resp->p_chown_restricted);
1070 		*p++ = htonl(resp->p_case_insensitive);
1071 		*p++ = htonl(resp->p_case_preserving);
1072 	}
1073 
1074 	return xdr_ressize_check(rqstp, p);
1075 }
1076 
1077 /* COMMIT */
1078 int
1079 nfs3svc_encode_commitres(struct svc_rqst *rqstp, u32 *p,
1080 					struct nfsd3_commitres *resp)
1081 {
1082 	p = encode_wcc_data(rqstp, p, &resp->fh);
1083 	/* Write verifier */
1084 	if (resp->status == 0) {
1085 		*p++ = htonl(nfssvc_boot.tv_sec);
1086 		*p++ = htonl(nfssvc_boot.tv_usec);
1087 	}
1088 	return xdr_ressize_check(rqstp, p);
1089 }
1090 
1091 /*
1092  * XDR release functions
1093  */
1094 int
1095 nfs3svc_release_fhandle(struct svc_rqst *rqstp, u32 *p,
1096 					struct nfsd3_attrstat *resp)
1097 {
1098 	fh_put(&resp->fh);
1099 	return 1;
1100 }
1101 
1102 int
1103 nfs3svc_release_fhandle2(struct svc_rqst *rqstp, u32 *p,
1104 					struct nfsd3_fhandle_pair *resp)
1105 {
1106 	fh_put(&resp->fh1);
1107 	fh_put(&resp->fh2);
1108 	return 1;
1109 }
1110