xref: /linux/fs/nfsd/nfs3xdr.c (revision 9ce7677cfd7cd871adb457c80bea3b581b839641)
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 {
159 	struct vfsmount *mnt = fhp->fh_export->ex_mnt;
160 	struct dentry	*dentry = fhp->fh_dentry;
161 	struct kstat stat;
162 	struct timespec time;
163 
164 	vfs_getattr(mnt, dentry, &stat);
165 
166 	*p++ = htonl(nfs3_ftypes[(stat.mode & S_IFMT) >> 12]);
167 	*p++ = htonl((u32) stat.mode);
168 	*p++ = htonl((u32) stat.nlink);
169 	*p++ = htonl((u32) nfsd_ruid(rqstp, stat.uid));
170 	*p++ = htonl((u32) nfsd_rgid(rqstp, stat.gid));
171 	if (S_ISLNK(stat.mode) && stat.size > NFS3_MAXPATHLEN) {
172 		p = xdr_encode_hyper(p, (u64) NFS3_MAXPATHLEN);
173 	} else {
174 		p = xdr_encode_hyper(p, (u64) stat.size);
175 	}
176 	p = xdr_encode_hyper(p, ((u64)stat.blocks) << 9);
177 	*p++ = htonl((u32) MAJOR(stat.rdev));
178 	*p++ = htonl((u32) MINOR(stat.rdev));
179 	if (is_fsid(fhp, rqstp->rq_reffh))
180 		p = xdr_encode_hyper(p, (u64) fhp->fh_export->ex_fsid);
181 	else
182 		p = xdr_encode_hyper(p, (u64) huge_encode_dev(stat.dev));
183 	p = xdr_encode_hyper(p, (u64) stat.ino);
184 	p = encode_time3(p, &stat.atime);
185 	lease_get_mtime(dentry->d_inode, &time);
186 	p = encode_time3(p, &time);
187 	p = encode_time3(p, &stat.ctime);
188 
189 	return p;
190 }
191 
192 static inline u32 *
193 encode_saved_post_attr(struct svc_rqst *rqstp, u32 *p, struct svc_fh *fhp)
194 {
195 	struct inode	*inode = fhp->fh_dentry->d_inode;
196 
197 	/* Attributes to follow */
198 	*p++ = xdr_one;
199 
200 	*p++ = htonl(nfs3_ftypes[(fhp->fh_post_mode & S_IFMT) >> 12]);
201 	*p++ = htonl((u32) fhp->fh_post_mode);
202 	*p++ = htonl((u32) fhp->fh_post_nlink);
203 	*p++ = htonl((u32) nfsd_ruid(rqstp, fhp->fh_post_uid));
204 	*p++ = htonl((u32) nfsd_rgid(rqstp, fhp->fh_post_gid));
205 	if (S_ISLNK(fhp->fh_post_mode) && fhp->fh_post_size > NFS3_MAXPATHLEN) {
206 		p = xdr_encode_hyper(p, (u64) NFS3_MAXPATHLEN);
207 	} else {
208 		p = xdr_encode_hyper(p, (u64) fhp->fh_post_size);
209 	}
210 	p = xdr_encode_hyper(p, ((u64)fhp->fh_post_blocks) << 9);
211 	*p++ = fhp->fh_post_rdev[0];
212 	*p++ = fhp->fh_post_rdev[1];
213 	if (is_fsid(fhp, rqstp->rq_reffh))
214 		p = xdr_encode_hyper(p, (u64) fhp->fh_export->ex_fsid);
215 	else
216 		p = xdr_encode_hyper(p, (u64)huge_encode_dev(inode->i_sb->s_dev));
217 	p = xdr_encode_hyper(p, (u64) inode->i_ino);
218 	p = encode_time3(p, &fhp->fh_post_atime);
219 	p = encode_time3(p, &fhp->fh_post_mtime);
220 	p = encode_time3(p, &fhp->fh_post_ctime);
221 
222 	return p;
223 }
224 
225 /*
226  * Encode post-operation attributes.
227  * The inode may be NULL if the call failed because of a stale file
228  * handle. In this case, no attributes are returned.
229  */
230 static u32 *
231 encode_post_op_attr(struct svc_rqst *rqstp, u32 *p, struct svc_fh *fhp)
232 {
233 	struct dentry *dentry = fhp->fh_dentry;
234 	if (dentry && dentry->d_inode != NULL) {
235 		*p++ = xdr_one;		/* attributes follow */
236 		return encode_fattr3(rqstp, p, fhp);
237 	}
238 	*p++ = xdr_zero;
239 	return p;
240 }
241 
242 /* Helper for NFSv3 ACLs */
243 u32 *
244 nfs3svc_encode_post_op_attr(struct svc_rqst *rqstp, u32 *p, struct svc_fh *fhp)
245 {
246 	return encode_post_op_attr(rqstp, p, fhp);
247 }
248 
249 /*
250  * Enocde weak cache consistency data
251  */
252 static u32 *
253 encode_wcc_data(struct svc_rqst *rqstp, u32 *p, struct svc_fh *fhp)
254 {
255 	struct dentry	*dentry = fhp->fh_dentry;
256 
257 	if (dentry && dentry->d_inode && fhp->fh_post_saved) {
258 		if (fhp->fh_pre_saved) {
259 			*p++ = xdr_one;
260 			p = xdr_encode_hyper(p, (u64) fhp->fh_pre_size);
261 			p = encode_time3(p, &fhp->fh_pre_mtime);
262 			p = encode_time3(p, &fhp->fh_pre_ctime);
263 		} else {
264 			*p++ = xdr_zero;
265 		}
266 		return encode_saved_post_attr(rqstp, p, fhp);
267 	}
268 	/* no pre- or post-attrs */
269 	*p++ = xdr_zero;
270 	return encode_post_op_attr(rqstp, p, fhp);
271 }
272 
273 
274 /*
275  * XDR decode functions
276  */
277 int
278 nfs3svc_decode_fhandle(struct svc_rqst *rqstp, u32 *p, struct nfsd_fhandle *args)
279 {
280 	if (!(p = decode_fh(p, &args->fh)))
281 		return 0;
282 	return xdr_argsize_check(rqstp, p);
283 }
284 
285 int
286 nfs3svc_decode_sattrargs(struct svc_rqst *rqstp, u32 *p,
287 					struct nfsd3_sattrargs *args)
288 {
289 	if (!(p = decode_fh(p, &args->fh))
290 	 || !(p = decode_sattr3(p, &args->attrs)))
291 		return 0;
292 
293 	if ((args->check_guard = ntohl(*p++)) != 0) {
294 		struct timespec time;
295 		p = decode_time3(p, &time);
296 		args->guardtime = time.tv_sec;
297 	}
298 
299 	return xdr_argsize_check(rqstp, p);
300 }
301 
302 int
303 nfs3svc_decode_diropargs(struct svc_rqst *rqstp, u32 *p,
304 					struct nfsd3_diropargs *args)
305 {
306 	if (!(p = decode_fh(p, &args->fh))
307 	 || !(p = decode_filename(p, &args->name, &args->len)))
308 		return 0;
309 
310 	return xdr_argsize_check(rqstp, p);
311 }
312 
313 int
314 nfs3svc_decode_accessargs(struct svc_rqst *rqstp, u32 *p,
315 					struct nfsd3_accessargs *args)
316 {
317 	if (!(p = decode_fh(p, &args->fh)))
318 		return 0;
319 	args->access = ntohl(*p++);
320 
321 	return xdr_argsize_check(rqstp, p);
322 }
323 
324 int
325 nfs3svc_decode_readargs(struct svc_rqst *rqstp, u32 *p,
326 					struct nfsd3_readargs *args)
327 {
328 	unsigned int len;
329 	int v,pn;
330 
331 	if (!(p = decode_fh(p, &args->fh))
332 	 || !(p = xdr_decode_hyper(p, &args->offset)))
333 		return 0;
334 
335 	len = args->count = ntohl(*p++);
336 
337 	if (len > NFSSVC_MAXBLKSIZE)
338 		len = NFSSVC_MAXBLKSIZE;
339 
340 	/* set up the kvec */
341 	v=0;
342 	while (len > 0) {
343 		pn = rqstp->rq_resused;
344 		svc_take_page(rqstp);
345 		args->vec[v].iov_base = page_address(rqstp->rq_respages[pn]);
346 		args->vec[v].iov_len = len < PAGE_SIZE? len : PAGE_SIZE;
347 		len -= args->vec[v].iov_len;
348 		v++;
349 	}
350 	args->vlen = v;
351 	return xdr_argsize_check(rqstp, p);
352 }
353 
354 int
355 nfs3svc_decode_writeargs(struct svc_rqst *rqstp, u32 *p,
356 					struct nfsd3_writeargs *args)
357 {
358 	unsigned int len, v, hdr;
359 
360 	if (!(p = decode_fh(p, &args->fh))
361 	 || !(p = xdr_decode_hyper(p, &args->offset)))
362 		return 0;
363 
364 	args->count = ntohl(*p++);
365 	args->stable = ntohl(*p++);
366 	len = args->len = ntohl(*p++);
367 
368 	hdr = (void*)p - rqstp->rq_arg.head[0].iov_base;
369 	if (rqstp->rq_arg.len < hdr ||
370 	    rqstp->rq_arg.len - hdr < len)
371 		return 0;
372 
373 	args->vec[0].iov_base = (void*)p;
374 	args->vec[0].iov_len = rqstp->rq_arg.head[0].iov_len - hdr;
375 
376 	if (len > NFSSVC_MAXBLKSIZE)
377 		len = NFSSVC_MAXBLKSIZE;
378 	v=  0;
379 	while (len > args->vec[v].iov_len) {
380 		len -= args->vec[v].iov_len;
381 		v++;
382 		args->vec[v].iov_base = page_address(rqstp->rq_argpages[v]);
383 		args->vec[v].iov_len = PAGE_SIZE;
384 	}
385 	args->vec[v].iov_len = len;
386 	args->vlen = v+1;
387 
388 	return args->count == args->len && args->vec[0].iov_len > 0;
389 }
390 
391 int
392 nfs3svc_decode_createargs(struct svc_rqst *rqstp, u32 *p,
393 					struct nfsd3_createargs *args)
394 {
395 	if (!(p = decode_fh(p, &args->fh))
396 	 || !(p = decode_filename(p, &args->name, &args->len)))
397 		return 0;
398 
399 	switch (args->createmode = ntohl(*p++)) {
400 	case NFS3_CREATE_UNCHECKED:
401 	case NFS3_CREATE_GUARDED:
402 		if (!(p = decode_sattr3(p, &args->attrs)))
403 			return 0;
404 		break;
405 	case NFS3_CREATE_EXCLUSIVE:
406 		args->verf = p;
407 		p += 2;
408 		break;
409 	default:
410 		return 0;
411 	}
412 
413 	return xdr_argsize_check(rqstp, p);
414 }
415 int
416 nfs3svc_decode_mkdirargs(struct svc_rqst *rqstp, u32 *p,
417 					struct nfsd3_createargs *args)
418 {
419 	if (!(p = decode_fh(p, &args->fh))
420 	 || !(p = decode_filename(p, &args->name, &args->len))
421 	 || !(p = decode_sattr3(p, &args->attrs)))
422 		return 0;
423 
424 	return xdr_argsize_check(rqstp, p);
425 }
426 
427 int
428 nfs3svc_decode_symlinkargs(struct svc_rqst *rqstp, u32 *p,
429 					struct nfsd3_symlinkargs *args)
430 {
431 	unsigned int len;
432 	int avail;
433 	char *old, *new;
434 	struct kvec *vec;
435 
436 	if (!(p = decode_fh(p, &args->ffh))
437 	 || !(p = decode_filename(p, &args->fname, &args->flen))
438 	 || !(p = decode_sattr3(p, &args->attrs))
439 		)
440 		return 0;
441 	/* now decode the pathname, which might be larger than the first page.
442 	 * As we have to check for nul's anyway, we copy it into a new page
443 	 * This page appears in the rq_res.pages list, but as pages_len is always
444 	 * 0, it won't get in the way
445 	 */
446 	svc_take_page(rqstp);
447 	len = ntohl(*p++);
448 	if (len == 0 || len > NFS3_MAXPATHLEN || len >= PAGE_SIZE)
449 		return 0;
450 	args->tname = new = page_address(rqstp->rq_respages[rqstp->rq_resused-1]);
451 	args->tlen = len;
452 	/* first copy and check from the first page */
453 	old = (char*)p;
454 	vec = &rqstp->rq_arg.head[0];
455 	avail = vec->iov_len - (old - (char*)vec->iov_base);
456 	while (len && avail && *old) {
457 		*new++ = *old++;
458 		len--;
459 		avail--;
460 	}
461 	/* now copy next page if there is one */
462 	if (len && !avail && rqstp->rq_arg.page_len) {
463 		avail = rqstp->rq_arg.page_len;
464 		if (avail > PAGE_SIZE) avail = PAGE_SIZE;
465 		old = page_address(rqstp->rq_arg.pages[0]);
466 	}
467 	while (len && avail && *old) {
468 		*new++ = *old++;
469 		len--;
470 		avail--;
471 	}
472 	*new = '\0';
473 	if (len)
474 		return 0;
475 
476 	return 1;
477 }
478 
479 int
480 nfs3svc_decode_mknodargs(struct svc_rqst *rqstp, u32 *p,
481 					struct nfsd3_mknodargs *args)
482 {
483 	if (!(p = decode_fh(p, &args->fh))
484 	 || !(p = decode_filename(p, &args->name, &args->len)))
485 		return 0;
486 
487 	args->ftype = ntohl(*p++);
488 
489 	if (args->ftype == NF3BLK  || args->ftype == NF3CHR
490 	 || args->ftype == NF3SOCK || args->ftype == NF3FIFO) {
491 		if (!(p = decode_sattr3(p, &args->attrs)))
492 			return 0;
493 	}
494 
495 	if (args->ftype == NF3BLK || args->ftype == NF3CHR) {
496 		args->major = ntohl(*p++);
497 		args->minor = ntohl(*p++);
498 	}
499 
500 	return xdr_argsize_check(rqstp, p);
501 }
502 
503 int
504 nfs3svc_decode_renameargs(struct svc_rqst *rqstp, u32 *p,
505 					struct nfsd3_renameargs *args)
506 {
507 	if (!(p = decode_fh(p, &args->ffh))
508 	 || !(p = decode_filename(p, &args->fname, &args->flen))
509 	 || !(p = decode_fh(p, &args->tfh))
510 	 || !(p = decode_filename(p, &args->tname, &args->tlen)))
511 		return 0;
512 
513 	return xdr_argsize_check(rqstp, p);
514 }
515 
516 int
517 nfs3svc_decode_readlinkargs(struct svc_rqst *rqstp, u32 *p,
518 					struct nfsd3_readlinkargs *args)
519 {
520 	if (!(p = decode_fh(p, &args->fh)))
521 		return 0;
522 	svc_take_page(rqstp);
523 	args->buffer = page_address(rqstp->rq_respages[rqstp->rq_resused-1]);
524 
525 	return xdr_argsize_check(rqstp, p);
526 }
527 
528 int
529 nfs3svc_decode_linkargs(struct svc_rqst *rqstp, u32 *p,
530 					struct nfsd3_linkargs *args)
531 {
532 	if (!(p = decode_fh(p, &args->ffh))
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_readdirargs(struct svc_rqst *rqstp, u32 *p,
542 					struct nfsd3_readdirargs *args)
543 {
544 	if (!(p = decode_fh(p, &args->fh)))
545 		return 0;
546 	p = xdr_decode_hyper(p, &args->cookie);
547 	args->verf   = p; p += 2;
548 	args->dircount = ~0;
549 	args->count  = ntohl(*p++);
550 
551 	if (args->count > PAGE_SIZE)
552 		args->count = PAGE_SIZE;
553 
554 	svc_take_page(rqstp);
555 	args->buffer = page_address(rqstp->rq_respages[rqstp->rq_resused-1]);
556 
557 	return xdr_argsize_check(rqstp, p);
558 }
559 
560 int
561 nfs3svc_decode_readdirplusargs(struct svc_rqst *rqstp, u32 *p,
562 					struct nfsd3_readdirargs *args)
563 {
564 	int len, pn;
565 
566 	if (!(p = decode_fh(p, &args->fh)))
567 		return 0;
568 	p = xdr_decode_hyper(p, &args->cookie);
569 	args->verf     = p; p += 2;
570 	args->dircount = ntohl(*p++);
571 	args->count    = ntohl(*p++);
572 
573 	len = (args->count > NFSSVC_MAXBLKSIZE) ? NFSSVC_MAXBLKSIZE :
574 						  args->count;
575 	args->count = len;
576 
577 	while (len > 0) {
578 		pn = rqstp->rq_resused;
579 		svc_take_page(rqstp);
580 		if (!args->buffer)
581 			args->buffer = page_address(rqstp->rq_respages[pn]);
582 		len -= PAGE_SIZE;
583 	}
584 
585 	return xdr_argsize_check(rqstp, p);
586 }
587 
588 int
589 nfs3svc_decode_commitargs(struct svc_rqst *rqstp, u32 *p,
590 					struct nfsd3_commitargs *args)
591 {
592 	if (!(p = decode_fh(p, &args->fh)))
593 		return 0;
594 	p = xdr_decode_hyper(p, &args->offset);
595 	args->count = ntohl(*p++);
596 
597 	return xdr_argsize_check(rqstp, p);
598 }
599 
600 /*
601  * XDR encode functions
602  */
603 /*
604  * There must be an encoding function for void results so svc_process
605  * will work properly.
606  */
607 int
608 nfs3svc_encode_voidres(struct svc_rqst *rqstp, u32 *p, void *dummy)
609 {
610 	return xdr_ressize_check(rqstp, p);
611 }
612 
613 /* GETATTR */
614 int
615 nfs3svc_encode_attrstat(struct svc_rqst *rqstp, u32 *p,
616 					struct nfsd3_attrstat *resp)
617 {
618 	if (resp->status == 0)
619 		p = encode_fattr3(rqstp, p, &resp->fh);
620 	return xdr_ressize_check(rqstp, p);
621 }
622 
623 /* SETATTR, REMOVE, RMDIR */
624 int
625 nfs3svc_encode_wccstat(struct svc_rqst *rqstp, u32 *p,
626 					struct nfsd3_attrstat *resp)
627 {
628 	p = encode_wcc_data(rqstp, p, &resp->fh);
629 	return xdr_ressize_check(rqstp, p);
630 }
631 
632 /* LOOKUP */
633 int
634 nfs3svc_encode_diropres(struct svc_rqst *rqstp, u32 *p,
635 					struct nfsd3_diropres *resp)
636 {
637 	if (resp->status == 0) {
638 		p = encode_fh(p, &resp->fh);
639 		p = encode_post_op_attr(rqstp, p, &resp->fh);
640 	}
641 	p = encode_post_op_attr(rqstp, p, &resp->dirfh);
642 	return xdr_ressize_check(rqstp, p);
643 }
644 
645 /* ACCESS */
646 int
647 nfs3svc_encode_accessres(struct svc_rqst *rqstp, u32 *p,
648 					struct nfsd3_accessres *resp)
649 {
650 	p = encode_post_op_attr(rqstp, p, &resp->fh);
651 	if (resp->status == 0)
652 		*p++ = htonl(resp->access);
653 	return xdr_ressize_check(rqstp, p);
654 }
655 
656 /* READLINK */
657 int
658 nfs3svc_encode_readlinkres(struct svc_rqst *rqstp, u32 *p,
659 					struct nfsd3_readlinkres *resp)
660 {
661 	p = encode_post_op_attr(rqstp, p, &resp->fh);
662 	if (resp->status == 0) {
663 		*p++ = htonl(resp->len);
664 		xdr_ressize_check(rqstp, p);
665 		rqstp->rq_res.page_len = resp->len;
666 		if (resp->len & 3) {
667 			/* need to pad the tail */
668 			rqstp->rq_restailpage = 0;
669 			rqstp->rq_res.tail[0].iov_base = p;
670 			*p = 0;
671 			rqstp->rq_res.tail[0].iov_len = 4 - (resp->len&3);
672 		}
673 		return 1;
674 	} else
675 		return xdr_ressize_check(rqstp, p);
676 }
677 
678 /* READ */
679 int
680 nfs3svc_encode_readres(struct svc_rqst *rqstp, u32 *p,
681 					struct nfsd3_readres *resp)
682 {
683 	p = encode_post_op_attr(rqstp, p, &resp->fh);
684 	if (resp->status == 0) {
685 		*p++ = htonl(resp->count);
686 		*p++ = htonl(resp->eof);
687 		*p++ = htonl(resp->count);	/* xdr opaque count */
688 		xdr_ressize_check(rqstp, p);
689 		/* now update rqstp->rq_res to reflect data aswell */
690 		rqstp->rq_res.page_len = resp->count;
691 		if (resp->count & 3) {
692 			/* need to pad the tail */
693 			rqstp->rq_restailpage = 0;
694 			rqstp->rq_res.tail[0].iov_base = p;
695 			*p = 0;
696 			rqstp->rq_res.tail[0].iov_len = 4 - (resp->count & 3);
697 		}
698 		return 1;
699 	} else
700 		return xdr_ressize_check(rqstp, p);
701 }
702 
703 /* WRITE */
704 int
705 nfs3svc_encode_writeres(struct svc_rqst *rqstp, u32 *p,
706 					struct nfsd3_writeres *resp)
707 {
708 	p = encode_wcc_data(rqstp, p, &resp->fh);
709 	if (resp->status == 0) {
710 		*p++ = htonl(resp->count);
711 		*p++ = htonl(resp->committed);
712 		*p++ = htonl(nfssvc_boot.tv_sec);
713 		*p++ = htonl(nfssvc_boot.tv_usec);
714 	}
715 	return xdr_ressize_check(rqstp, p);
716 }
717 
718 /* CREATE, MKDIR, SYMLINK, MKNOD */
719 int
720 nfs3svc_encode_createres(struct svc_rqst *rqstp, u32 *p,
721 					struct nfsd3_diropres *resp)
722 {
723 	if (resp->status == 0) {
724 		*p++ = xdr_one;
725 		p = encode_fh(p, &resp->fh);
726 		p = encode_post_op_attr(rqstp, p, &resp->fh);
727 	}
728 	p = encode_wcc_data(rqstp, p, &resp->dirfh);
729 	return xdr_ressize_check(rqstp, p);
730 }
731 
732 /* RENAME */
733 int
734 nfs3svc_encode_renameres(struct svc_rqst *rqstp, u32 *p,
735 					struct nfsd3_renameres *resp)
736 {
737 	p = encode_wcc_data(rqstp, p, &resp->ffh);
738 	p = encode_wcc_data(rqstp, p, &resp->tfh);
739 	return xdr_ressize_check(rqstp, p);
740 }
741 
742 /* LINK */
743 int
744 nfs3svc_encode_linkres(struct svc_rqst *rqstp, u32 *p,
745 					struct nfsd3_linkres *resp)
746 {
747 	p = encode_post_op_attr(rqstp, p, &resp->fh);
748 	p = encode_wcc_data(rqstp, p, &resp->tfh);
749 	return xdr_ressize_check(rqstp, p);
750 }
751 
752 /* READDIR */
753 int
754 nfs3svc_encode_readdirres(struct svc_rqst *rqstp, u32 *p,
755 					struct nfsd3_readdirres *resp)
756 {
757 	p = encode_post_op_attr(rqstp, p, &resp->fh);
758 
759 	if (resp->status == 0) {
760 		/* stupid readdir cookie */
761 		memcpy(p, resp->verf, 8); p += 2;
762 		xdr_ressize_check(rqstp, p);
763 		if (rqstp->rq_res.head[0].iov_len + (2<<2) > PAGE_SIZE)
764 			return 1; /*No room for trailer */
765 		rqstp->rq_res.page_len = (resp->count) << 2;
766 
767 		/* add the 'tail' to the end of the 'head' page - page 0. */
768 		rqstp->rq_restailpage = 0;
769 		rqstp->rq_res.tail[0].iov_base = p;
770 		*p++ = 0;		/* no more entries */
771 		*p++ = htonl(resp->common.err == nfserr_eof);
772 		rqstp->rq_res.tail[0].iov_len = 2<<2;
773 		return 1;
774 	} else
775 		return xdr_ressize_check(rqstp, p);
776 }
777 
778 static inline u32 *
779 encode_entry_baggage(struct nfsd3_readdirres *cd, u32 *p, const char *name,
780 	     int namlen, ino_t ino)
781 {
782 	*p++ = xdr_one;				 /* mark entry present */
783 	p    = xdr_encode_hyper(p, ino);	 /* file id */
784 	p    = xdr_encode_array(p, name, namlen);/* name length & name */
785 
786 	cd->offset = p;				/* remember pointer */
787 	p = xdr_encode_hyper(p, NFS_OFFSET_MAX);/* offset of next entry */
788 
789 	return p;
790 }
791 
792 static inline u32 *
793 encode_entryplus_baggage(struct nfsd3_readdirres *cd, u32 *p,
794 		struct svc_fh *fhp)
795 {
796 		p = encode_post_op_attr(cd->rqstp, p, fhp);
797 		*p++ = xdr_one;			/* yes, a file handle follows */
798 		p = encode_fh(p, fhp);
799 		fh_put(fhp);
800 		return p;
801 }
802 
803 static int
804 compose_entry_fh(struct nfsd3_readdirres *cd, struct svc_fh *fhp,
805 		const char *name, int namlen)
806 {
807 	struct svc_export	*exp;
808 	struct dentry		*dparent, *dchild;
809 	int rv = 0;
810 
811 	dparent = cd->fh.fh_dentry;
812 	exp  = cd->fh.fh_export;
813 
814 	fh_init(fhp, NFS3_FHSIZE);
815 	if (isdotent(name, namlen)) {
816 		if (namlen == 2) {
817 			dchild = dget_parent(dparent);
818 			if (dchild == dparent) {
819 				/* filesystem root - cannot return filehandle for ".." */
820 				dput(dchild);
821 				return 1;
822 			}
823 		} else
824 			dchild = dget(dparent);
825 	} else
826 		dchild = lookup_one_len(name, dparent, namlen);
827 	if (IS_ERR(dchild))
828 		return 1;
829 	if (d_mountpoint(dchild) ||
830 	    fh_compose(fhp, exp, dchild, &cd->fh) != 0 ||
831 	    !dchild->d_inode)
832 		rv = 1;
833 	dput(dchild);
834 	return rv;
835 }
836 
837 /*
838  * Encode a directory entry. This one works for both normal readdir
839  * and readdirplus.
840  * The normal readdir reply requires 2 (fileid) + 1 (stringlen)
841  * + string + 2 (cookie) + 1 (next) words, i.e. 6 + strlen.
842  *
843  * The readdirplus baggage is 1+21 words for post_op_attr, plus the
844  * file handle.
845  */
846 
847 #define NFS3_ENTRY_BAGGAGE	(2 + 1 + 2 + 1)
848 #define NFS3_ENTRYPLUS_BAGGAGE	(1 + 21 + 1 + (NFS3_FHSIZE >> 2))
849 static int
850 encode_entry(struct readdir_cd *ccd, const char *name,
851 	     int namlen, off_t offset, ino_t ino, unsigned int d_type, int plus)
852 {
853 	struct nfsd3_readdirres *cd = container_of(ccd, struct nfsd3_readdirres,
854 		       					common);
855 	u32		*p = cd->buffer;
856 	caddr_t		curr_page_addr = NULL;
857 	int		pn;		/* current page number */
858 	int		slen;		/* string (name) length */
859 	int		elen;		/* estimated entry length in words */
860 	int		num_entry_words = 0;	/* actual number of words */
861 
862 	if (cd->offset) {
863 		u64 offset64 = offset;
864 
865 		if (unlikely(cd->offset1)) {
866 			/* we ended up with offset on a page boundary */
867 			*cd->offset = htonl(offset64 >> 32);
868 			*cd->offset1 = htonl(offset64 & 0xffffffff);
869 			cd->offset1 = NULL;
870 		} else {
871 			xdr_encode_hyper(cd->offset, (u64) offset);
872 		}
873 	}
874 
875 	/*
876 	dprintk("encode_entry(%.*s @%ld%s)\n",
877 		namlen, name, (long) offset, plus? " plus" : "");
878 	 */
879 
880 	/* truncate filename if too long */
881 	if (namlen > NFS3_MAXNAMLEN)
882 		namlen = NFS3_MAXNAMLEN;
883 
884 	slen = XDR_QUADLEN(namlen);
885 	elen = slen + NFS3_ENTRY_BAGGAGE
886 		+ (plus? NFS3_ENTRYPLUS_BAGGAGE : 0);
887 
888 	if (cd->buflen < elen) {
889 		cd->common.err = nfserr_toosmall;
890 		return -EINVAL;
891 	}
892 
893 	/* determine which page in rq_respages[] we are currently filling */
894 	for (pn=1; pn < cd->rqstp->rq_resused; pn++) {
895 		curr_page_addr = page_address(cd->rqstp->rq_respages[pn]);
896 
897 		if (((caddr_t)cd->buffer >= curr_page_addr) &&
898 		    ((caddr_t)cd->buffer <  curr_page_addr + PAGE_SIZE))
899 			break;
900 	}
901 
902 	if ((caddr_t)(cd->buffer + elen) < (curr_page_addr + PAGE_SIZE)) {
903 		/* encode entry in current page */
904 
905 		p = encode_entry_baggage(cd, p, name, namlen, ino);
906 
907 		/* throw in readdirplus baggage */
908 		if (plus) {
909 			struct svc_fh	fh;
910 
911 			if (compose_entry_fh(cd, &fh, name, namlen) > 0) {
912 				*p++ = 0;
913 				*p++ = 0;
914 			} else
915 				p = encode_entryplus_baggage(cd, p, &fh);
916 		}
917 		num_entry_words = p - cd->buffer;
918 	} else if (cd->rqstp->rq_respages[pn+1] != NULL) {
919 		/* temporarily encode entry into next page, then move back to
920 		 * current and next page in rq_respages[] */
921 		u32 *p1, *tmp;
922 		int len1, len2;
923 
924 		/* grab next page for temporary storage of entry */
925 		p1 = tmp = page_address(cd->rqstp->rq_respages[pn+1]);
926 
927 		p1 = encode_entry_baggage(cd, p1, name, namlen, ino);
928 
929 		/* throw in readdirplus baggage */
930 		if (plus) {
931 			struct svc_fh	fh;
932 
933 			if (compose_entry_fh(cd, &fh, name, namlen) > 0) {
934 				/* zero out the filehandle */
935 				*p1++ = 0;
936 				*p1++ = 0;
937 			} else
938 				p1 = encode_entryplus_baggage(cd, p1, &fh);
939 		}
940 
941 		/* determine entry word length and lengths to go in pages */
942 		num_entry_words = p1 - tmp;
943 		len1 = curr_page_addr + PAGE_SIZE - (caddr_t)cd->buffer;
944 		if ((num_entry_words << 2) < len1) {
945 			/* the actual number of words in the entry is less
946 			 * than elen and can still fit in the current page
947 			 */
948 			memmove(p, tmp, num_entry_words << 2);
949 			p += num_entry_words;
950 
951 			/* update offset */
952 			cd->offset = cd->buffer + (cd->offset - tmp);
953 		} else {
954 			unsigned int offset_r = (cd->offset - tmp) << 2;
955 
956 			/* update pointer to offset location.
957 			 * This is a 64bit quantity, so we need to
958 			 * deal with 3 cases:
959 			 *  -	entirely in first page
960 			 *  -	entirely in second page
961 			 *  -	4 bytes in each page
962 			 */
963 			if (offset_r + 8 <= len1) {
964 				cd->offset = p + (cd->offset - tmp);
965 			} else if (offset_r >= len1) {
966 				cd->offset -= len1 >> 2;
967 			} else {
968 				/* sitting on the fence */
969 				BUG_ON(offset_r != len1 - 4);
970 				cd->offset = p + (cd->offset - tmp);
971 				cd->offset1 = tmp;
972 			}
973 
974 			len2 = (num_entry_words << 2) - len1;
975 
976 			/* move from temp page to current and next pages */
977 			memmove(p, tmp, len1);
978 			memmove(tmp, (caddr_t)tmp+len1, len2);
979 
980 			p = tmp + (len2 >> 2);
981 		}
982 	}
983 	else {
984 		cd->common.err = nfserr_toosmall;
985 		return -EINVAL;
986 	}
987 
988 	cd->buflen -= num_entry_words;
989 	cd->buffer = p;
990 	cd->common.err = nfs_ok;
991 	return 0;
992 
993 }
994 
995 int
996 nfs3svc_encode_entry(struct readdir_cd *cd, const char *name,
997 		     int namlen, loff_t offset, ino_t ino, unsigned int d_type)
998 {
999 	return encode_entry(cd, name, namlen, offset, ino, d_type, 0);
1000 }
1001 
1002 int
1003 nfs3svc_encode_entry_plus(struct readdir_cd *cd, const char *name,
1004 			  int namlen, loff_t offset, ino_t ino, unsigned int d_type)
1005 {
1006 	return encode_entry(cd, name, namlen, offset, ino, d_type, 1);
1007 }
1008 
1009 /* FSSTAT */
1010 int
1011 nfs3svc_encode_fsstatres(struct svc_rqst *rqstp, u32 *p,
1012 					struct nfsd3_fsstatres *resp)
1013 {
1014 	struct kstatfs	*s = &resp->stats;
1015 	u64		bs = s->f_bsize;
1016 
1017 	*p++ = xdr_zero;	/* no post_op_attr */
1018 
1019 	if (resp->status == 0) {
1020 		p = xdr_encode_hyper(p, bs * s->f_blocks);	/* total bytes */
1021 		p = xdr_encode_hyper(p, bs * s->f_bfree);	/* free bytes */
1022 		p = xdr_encode_hyper(p, bs * s->f_bavail);	/* user available bytes */
1023 		p = xdr_encode_hyper(p, s->f_files);	/* total inodes */
1024 		p = xdr_encode_hyper(p, s->f_ffree);	/* free inodes */
1025 		p = xdr_encode_hyper(p, s->f_ffree);	/* user available inodes */
1026 		*p++ = htonl(resp->invarsec);	/* mean unchanged time */
1027 	}
1028 	return xdr_ressize_check(rqstp, p);
1029 }
1030 
1031 /* FSINFO */
1032 int
1033 nfs3svc_encode_fsinfores(struct svc_rqst *rqstp, u32 *p,
1034 					struct nfsd3_fsinfores *resp)
1035 {
1036 	*p++ = xdr_zero;	/* no post_op_attr */
1037 
1038 	if (resp->status == 0) {
1039 		*p++ = htonl(resp->f_rtmax);
1040 		*p++ = htonl(resp->f_rtpref);
1041 		*p++ = htonl(resp->f_rtmult);
1042 		*p++ = htonl(resp->f_wtmax);
1043 		*p++ = htonl(resp->f_wtpref);
1044 		*p++ = htonl(resp->f_wtmult);
1045 		*p++ = htonl(resp->f_dtpref);
1046 		p = xdr_encode_hyper(p, resp->f_maxfilesize);
1047 		*p++ = xdr_one;
1048 		*p++ = xdr_zero;
1049 		*p++ = htonl(resp->f_properties);
1050 	}
1051 
1052 	return xdr_ressize_check(rqstp, p);
1053 }
1054 
1055 /* PATHCONF */
1056 int
1057 nfs3svc_encode_pathconfres(struct svc_rqst *rqstp, u32 *p,
1058 					struct nfsd3_pathconfres *resp)
1059 {
1060 	*p++ = xdr_zero;	/* no post_op_attr */
1061 
1062 	if (resp->status == 0) {
1063 		*p++ = htonl(resp->p_link_max);
1064 		*p++ = htonl(resp->p_name_max);
1065 		*p++ = htonl(resp->p_no_trunc);
1066 		*p++ = htonl(resp->p_chown_restricted);
1067 		*p++ = htonl(resp->p_case_insensitive);
1068 		*p++ = htonl(resp->p_case_preserving);
1069 	}
1070 
1071 	return xdr_ressize_check(rqstp, p);
1072 }
1073 
1074 /* COMMIT */
1075 int
1076 nfs3svc_encode_commitres(struct svc_rqst *rqstp, u32 *p,
1077 					struct nfsd3_commitres *resp)
1078 {
1079 	p = encode_wcc_data(rqstp, p, &resp->fh);
1080 	/* Write verifier */
1081 	if (resp->status == 0) {
1082 		*p++ = htonl(nfssvc_boot.tv_sec);
1083 		*p++ = htonl(nfssvc_boot.tv_usec);
1084 	}
1085 	return xdr_ressize_check(rqstp, p);
1086 }
1087 
1088 /*
1089  * XDR release functions
1090  */
1091 int
1092 nfs3svc_release_fhandle(struct svc_rqst *rqstp, u32 *p,
1093 					struct nfsd3_attrstat *resp)
1094 {
1095 	fh_put(&resp->fh);
1096 	return 1;
1097 }
1098 
1099 int
1100 nfs3svc_release_fhandle2(struct svc_rqst *rqstp, u32 *p,
1101 					struct nfsd3_fhandle_pair *resp)
1102 {
1103 	fh_put(&resp->fh1);
1104 	fh_put(&resp->fh2);
1105 	return 1;
1106 }
1107