xref: /linux/fs/nfsd/nfs4xdr.c (revision f2ee442115c9b6219083c019939a9cc0c9abb2f8)
1 /*
2  *  Server-side XDR for NFSv4
3  *
4  *  Copyright (c) 2002 The Regents of the University of Michigan.
5  *  All rights reserved.
6  *
7  *  Kendrick Smith <kmsmith@umich.edu>
8  *  Andy Adamson   <andros@umich.edu>
9  *
10  *  Redistribution and use in source and binary forms, with or without
11  *  modification, are permitted provided that the following conditions
12  *  are met:
13  *
14  *  1. Redistributions of source code must retain the above copyright
15  *     notice, this list of conditions and the following disclaimer.
16  *  2. Redistributions in binary form must reproduce the above copyright
17  *     notice, this list of conditions and the following disclaimer in the
18  *     documentation and/or other materials provided with the distribution.
19  *  3. Neither the name of the University nor the names of its
20  *     contributors may be used to endorse or promote products derived
21  *     from this software without specific prior written permission.
22  *
23  *  THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
24  *  WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
25  *  MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
26  *  DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  *  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
28  *  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
29  *  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
30  *  BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31  *  LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32  *  NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33  *  SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34  *
35  * TODO: Neil Brown made the following observation:  We currently
36  * initially reserve NFSD_BUFSIZE space on the transmit queue and
37  * never release any of that until the request is complete.
38  * It would be good to calculate a new maximum response size while
39  * decoding the COMPOUND, and call svc_reserve with this number
40  * at the end of nfs4svc_decode_compoundargs.
41  */
42 
43 #include <linux/slab.h>
44 #include <linux/namei.h>
45 #include <linux/statfs.h>
46 #include <linux/utsname.h>
47 #include <linux/pagemap.h>
48 #include <linux/sunrpc/svcauth_gss.h>
49 
50 #include "idmap.h"
51 #include "acl.h"
52 #include "xdr4.h"
53 #include "vfs.h"
54 #include "state.h"
55 #include "cache.h"
56 
57 #define NFSDDBG_FACILITY		NFSDDBG_XDR
58 
59 /*
60  * As per referral draft, the fsid for a referral MUST be different from the fsid of the containing
61  * directory in order to indicate to the client that a filesystem boundary is present
62  * We use a fixed fsid for a referral
63  */
64 #define NFS4_REFERRAL_FSID_MAJOR	0x8000000ULL
65 #define NFS4_REFERRAL_FSID_MINOR	0x8000000ULL
66 
67 static __be32
68 check_filename(char *str, int len, __be32 err)
69 {
70 	int i;
71 
72 	if (len == 0)
73 		return nfserr_inval;
74 	if (isdotent(str, len))
75 		return err;
76 	for (i = 0; i < len; i++)
77 		if (str[i] == '/')
78 			return err;
79 	return 0;
80 }
81 
82 #define DECODE_HEAD				\
83 	__be32 *p;				\
84 	__be32 status
85 #define DECODE_TAIL				\
86 	status = 0;				\
87 out:						\
88 	return status;				\
89 xdr_error:					\
90 	dprintk("NFSD: xdr error (%s:%d)\n",	\
91 			__FILE__, __LINE__);	\
92 	status = nfserr_bad_xdr;		\
93 	goto out
94 
95 #define READ32(x)         (x) = ntohl(*p++)
96 #define READ64(x)         do {			\
97 	(x) = (u64)ntohl(*p++) << 32;		\
98 	(x) |= ntohl(*p++);			\
99 } while (0)
100 #define READTIME(x)       do {			\
101 	p++;					\
102 	(x) = ntohl(*p++);			\
103 	p++;					\
104 } while (0)
105 #define READMEM(x,nbytes) do {			\
106 	x = (char *)p;				\
107 	p += XDR_QUADLEN(nbytes);		\
108 } while (0)
109 #define SAVEMEM(x,nbytes) do {			\
110 	if (!(x = (p==argp->tmp || p == argp->tmpp) ? \
111  		savemem(argp, p, nbytes) :	\
112  		(char *)p)) {			\
113 		dprintk("NFSD: xdr error (%s:%d)\n", \
114 				__FILE__, __LINE__); \
115 		goto xdr_error;			\
116 		}				\
117 	p += XDR_QUADLEN(nbytes);		\
118 } while (0)
119 #define COPYMEM(x,nbytes) do {			\
120 	memcpy((x), p, nbytes);			\
121 	p += XDR_QUADLEN(nbytes);		\
122 } while (0)
123 
124 /* READ_BUF, read_buf(): nbytes must be <= PAGE_SIZE */
125 #define READ_BUF(nbytes)  do {			\
126 	if (nbytes <= (u32)((char *)argp->end - (char *)argp->p)) {	\
127 		p = argp->p;			\
128 		argp->p += XDR_QUADLEN(nbytes);	\
129 	} else if (!(p = read_buf(argp, nbytes))) { \
130 		dprintk("NFSD: xdr error (%s:%d)\n", \
131 				__FILE__, __LINE__); \
132 		goto xdr_error;			\
133 	}					\
134 } while (0)
135 
136 static void save_buf(struct nfsd4_compoundargs *argp, struct nfsd4_saved_compoundargs *savep)
137 {
138 	savep->p        = argp->p;
139 	savep->end      = argp->end;
140 	savep->pagelen  = argp->pagelen;
141 	savep->pagelist = argp->pagelist;
142 }
143 
144 static void restore_buf(struct nfsd4_compoundargs *argp, struct nfsd4_saved_compoundargs *savep)
145 {
146 	argp->p        = savep->p;
147 	argp->end      = savep->end;
148 	argp->pagelen  = savep->pagelen;
149 	argp->pagelist = savep->pagelist;
150 }
151 
152 static __be32 *read_buf(struct nfsd4_compoundargs *argp, u32 nbytes)
153 {
154 	/* We want more bytes than seem to be available.
155 	 * Maybe we need a new page, maybe we have just run out
156 	 */
157 	unsigned int avail = (char *)argp->end - (char *)argp->p;
158 	__be32 *p;
159 	if (avail + argp->pagelen < nbytes)
160 		return NULL;
161 	if (avail + PAGE_SIZE < nbytes) /* need more than a page !! */
162 		return NULL;
163 	/* ok, we can do it with the current plus the next page */
164 	if (nbytes <= sizeof(argp->tmp))
165 		p = argp->tmp;
166 	else {
167 		kfree(argp->tmpp);
168 		p = argp->tmpp = kmalloc(nbytes, GFP_KERNEL);
169 		if (!p)
170 			return NULL;
171 
172 	}
173 	/*
174 	 * The following memcpy is safe because read_buf is always
175 	 * called with nbytes > avail, and the two cases above both
176 	 * guarantee p points to at least nbytes bytes.
177 	 */
178 	memcpy(p, argp->p, avail);
179 	/* step to next page */
180 	argp->p = page_address(argp->pagelist[0]);
181 	argp->pagelist++;
182 	if (argp->pagelen < PAGE_SIZE) {
183 		argp->end = argp->p + (argp->pagelen>>2);
184 		argp->pagelen = 0;
185 	} else {
186 		argp->end = argp->p + (PAGE_SIZE>>2);
187 		argp->pagelen -= PAGE_SIZE;
188 	}
189 	memcpy(((char*)p)+avail, argp->p, (nbytes - avail));
190 	argp->p += XDR_QUADLEN(nbytes - avail);
191 	return p;
192 }
193 
194 static int zero_clientid(clientid_t *clid)
195 {
196 	return (clid->cl_boot == 0) && (clid->cl_id == 0);
197 }
198 
199 static int
200 defer_free(struct nfsd4_compoundargs *argp,
201 		void (*release)(const void *), void *p)
202 {
203 	struct tmpbuf *tb;
204 
205 	tb = kmalloc(sizeof(*tb), GFP_KERNEL);
206 	if (!tb)
207 		return -ENOMEM;
208 	tb->buf = p;
209 	tb->release = release;
210 	tb->next = argp->to_free;
211 	argp->to_free = tb;
212 	return 0;
213 }
214 
215 static char *savemem(struct nfsd4_compoundargs *argp, __be32 *p, int nbytes)
216 {
217 	if (p == argp->tmp) {
218 		p = kmalloc(nbytes, GFP_KERNEL);
219 		if (!p)
220 			return NULL;
221 		memcpy(p, argp->tmp, nbytes);
222 	} else {
223 		BUG_ON(p != argp->tmpp);
224 		argp->tmpp = NULL;
225 	}
226 	if (defer_free(argp, kfree, p)) {
227 		kfree(p);
228 		return NULL;
229 	} else
230 		return (char *)p;
231 }
232 
233 static __be32
234 nfsd4_decode_bitmap(struct nfsd4_compoundargs *argp, u32 *bmval)
235 {
236 	u32 bmlen;
237 	DECODE_HEAD;
238 
239 	bmval[0] = 0;
240 	bmval[1] = 0;
241 	bmval[2] = 0;
242 
243 	READ_BUF(4);
244 	READ32(bmlen);
245 	if (bmlen > 1000)
246 		goto xdr_error;
247 
248 	READ_BUF(bmlen << 2);
249 	if (bmlen > 0)
250 		READ32(bmval[0]);
251 	if (bmlen > 1)
252 		READ32(bmval[1]);
253 	if (bmlen > 2)
254 		READ32(bmval[2]);
255 
256 	DECODE_TAIL;
257 }
258 
259 static __be32
260 nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval,
261 		   struct iattr *iattr, struct nfs4_acl **acl)
262 {
263 	int expected_len, len = 0;
264 	u32 dummy32;
265 	char *buf;
266 	int host_err;
267 
268 	DECODE_HEAD;
269 	iattr->ia_valid = 0;
270 	if ((status = nfsd4_decode_bitmap(argp, bmval)))
271 		return status;
272 
273 	READ_BUF(4);
274 	READ32(expected_len);
275 
276 	if (bmval[0] & FATTR4_WORD0_SIZE) {
277 		READ_BUF(8);
278 		len += 8;
279 		READ64(iattr->ia_size);
280 		iattr->ia_valid |= ATTR_SIZE;
281 	}
282 	if (bmval[0] & FATTR4_WORD0_ACL) {
283 		int nace;
284 		struct nfs4_ace *ace;
285 
286 		READ_BUF(4); len += 4;
287 		READ32(nace);
288 
289 		if (nace > NFS4_ACL_MAX)
290 			return nfserr_resource;
291 
292 		*acl = nfs4_acl_new(nace);
293 		if (*acl == NULL) {
294 			host_err = -ENOMEM;
295 			goto out_nfserr;
296 		}
297 		defer_free(argp, kfree, *acl);
298 
299 		(*acl)->naces = nace;
300 		for (ace = (*acl)->aces; ace < (*acl)->aces + nace; ace++) {
301 			READ_BUF(16); len += 16;
302 			READ32(ace->type);
303 			READ32(ace->flag);
304 			READ32(ace->access_mask);
305 			READ32(dummy32);
306 			READ_BUF(dummy32);
307 			len += XDR_QUADLEN(dummy32) << 2;
308 			READMEM(buf, dummy32);
309 			ace->whotype = nfs4_acl_get_whotype(buf, dummy32);
310 			status = nfs_ok;
311 			if (ace->whotype != NFS4_ACL_WHO_NAMED)
312 				ace->who = 0;
313 			else if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP)
314 				status = nfsd_map_name_to_gid(argp->rqstp,
315 						buf, dummy32, &ace->who);
316 			else
317 				status = nfsd_map_name_to_uid(argp->rqstp,
318 						buf, dummy32, &ace->who);
319 			if (status)
320 				return status;
321 		}
322 	} else
323 		*acl = NULL;
324 	if (bmval[1] & FATTR4_WORD1_MODE) {
325 		READ_BUF(4);
326 		len += 4;
327 		READ32(iattr->ia_mode);
328 		iattr->ia_mode &= (S_IFMT | S_IALLUGO);
329 		iattr->ia_valid |= ATTR_MODE;
330 	}
331 	if (bmval[1] & FATTR4_WORD1_OWNER) {
332 		READ_BUF(4);
333 		len += 4;
334 		READ32(dummy32);
335 		READ_BUF(dummy32);
336 		len += (XDR_QUADLEN(dummy32) << 2);
337 		READMEM(buf, dummy32);
338 		if ((status = nfsd_map_name_to_uid(argp->rqstp, buf, dummy32, &iattr->ia_uid)))
339 			return status;
340 		iattr->ia_valid |= ATTR_UID;
341 	}
342 	if (bmval[1] & FATTR4_WORD1_OWNER_GROUP) {
343 		READ_BUF(4);
344 		len += 4;
345 		READ32(dummy32);
346 		READ_BUF(dummy32);
347 		len += (XDR_QUADLEN(dummy32) << 2);
348 		READMEM(buf, dummy32);
349 		if ((status = nfsd_map_name_to_gid(argp->rqstp, buf, dummy32, &iattr->ia_gid)))
350 			return status;
351 		iattr->ia_valid |= ATTR_GID;
352 	}
353 	if (bmval[1] & FATTR4_WORD1_TIME_ACCESS_SET) {
354 		READ_BUF(4);
355 		len += 4;
356 		READ32(dummy32);
357 		switch (dummy32) {
358 		case NFS4_SET_TO_CLIENT_TIME:
359 			/* We require the high 32 bits of 'seconds' to be 0, and we ignore
360 			   all 32 bits of 'nseconds'. */
361 			READ_BUF(12);
362 			len += 12;
363 			READ32(dummy32);
364 			if (dummy32)
365 				return nfserr_inval;
366 			READ32(iattr->ia_atime.tv_sec);
367 			READ32(iattr->ia_atime.tv_nsec);
368 			if (iattr->ia_atime.tv_nsec >= (u32)1000000000)
369 				return nfserr_inval;
370 			iattr->ia_valid |= (ATTR_ATIME | ATTR_ATIME_SET);
371 			break;
372 		case NFS4_SET_TO_SERVER_TIME:
373 			iattr->ia_valid |= ATTR_ATIME;
374 			break;
375 		default:
376 			goto xdr_error;
377 		}
378 	}
379 	if (bmval[1] & FATTR4_WORD1_TIME_MODIFY_SET) {
380 		READ_BUF(4);
381 		len += 4;
382 		READ32(dummy32);
383 		switch (dummy32) {
384 		case NFS4_SET_TO_CLIENT_TIME:
385 			/* We require the high 32 bits of 'seconds' to be 0, and we ignore
386 			   all 32 bits of 'nseconds'. */
387 			READ_BUF(12);
388 			len += 12;
389 			READ32(dummy32);
390 			if (dummy32)
391 				return nfserr_inval;
392 			READ32(iattr->ia_mtime.tv_sec);
393 			READ32(iattr->ia_mtime.tv_nsec);
394 			if (iattr->ia_mtime.tv_nsec >= (u32)1000000000)
395 				return nfserr_inval;
396 			iattr->ia_valid |= (ATTR_MTIME | ATTR_MTIME_SET);
397 			break;
398 		case NFS4_SET_TO_SERVER_TIME:
399 			iattr->ia_valid |= ATTR_MTIME;
400 			break;
401 		default:
402 			goto xdr_error;
403 		}
404 	}
405 	if (bmval[0] & ~NFSD_WRITEABLE_ATTRS_WORD0
406 	    || bmval[1] & ~NFSD_WRITEABLE_ATTRS_WORD1
407 	    || bmval[2] & ~NFSD_WRITEABLE_ATTRS_WORD2)
408 		READ_BUF(expected_len - len);
409 	else if (len != expected_len)
410 		goto xdr_error;
411 
412 	DECODE_TAIL;
413 
414 out_nfserr:
415 	status = nfserrno(host_err);
416 	goto out;
417 }
418 
419 static __be32
420 nfsd4_decode_stateid(struct nfsd4_compoundargs *argp, stateid_t *sid)
421 {
422 	DECODE_HEAD;
423 
424 	READ_BUF(sizeof(stateid_t));
425 	READ32(sid->si_generation);
426 	COPYMEM(&sid->si_opaque, sizeof(stateid_opaque_t));
427 
428 	DECODE_TAIL;
429 }
430 
431 static __be32
432 nfsd4_decode_access(struct nfsd4_compoundargs *argp, struct nfsd4_access *access)
433 {
434 	DECODE_HEAD;
435 
436 	READ_BUF(4);
437 	READ32(access->ac_req_access);
438 
439 	DECODE_TAIL;
440 }
441 
442 static __be32 nfsd4_decode_bind_conn_to_session(struct nfsd4_compoundargs *argp, struct nfsd4_bind_conn_to_session *bcts)
443 {
444 	DECODE_HEAD;
445 
446 	READ_BUF(NFS4_MAX_SESSIONID_LEN + 8);
447 	COPYMEM(bcts->sessionid.data, NFS4_MAX_SESSIONID_LEN);
448 	READ32(bcts->dir);
449 	/* XXX: skipping ctsa_use_conn_in_rdma_mode.  Perhaps Tom Tucker
450 	 * could help us figure out we should be using it. */
451 	DECODE_TAIL;
452 }
453 
454 static __be32
455 nfsd4_decode_close(struct nfsd4_compoundargs *argp, struct nfsd4_close *close)
456 {
457 	DECODE_HEAD;
458 
459 	READ_BUF(4);
460 	READ32(close->cl_seqid);
461 	return nfsd4_decode_stateid(argp, &close->cl_stateid);
462 
463 	DECODE_TAIL;
464 }
465 
466 
467 static __be32
468 nfsd4_decode_commit(struct nfsd4_compoundargs *argp, struct nfsd4_commit *commit)
469 {
470 	DECODE_HEAD;
471 
472 	READ_BUF(12);
473 	READ64(commit->co_offset);
474 	READ32(commit->co_count);
475 
476 	DECODE_TAIL;
477 }
478 
479 static __be32
480 nfsd4_decode_create(struct nfsd4_compoundargs *argp, struct nfsd4_create *create)
481 {
482 	DECODE_HEAD;
483 
484 	READ_BUF(4);
485 	READ32(create->cr_type);
486 	switch (create->cr_type) {
487 	case NF4LNK:
488 		READ_BUF(4);
489 		READ32(create->cr_linklen);
490 		READ_BUF(create->cr_linklen);
491 		SAVEMEM(create->cr_linkname, create->cr_linklen);
492 		break;
493 	case NF4BLK:
494 	case NF4CHR:
495 		READ_BUF(8);
496 		READ32(create->cr_specdata1);
497 		READ32(create->cr_specdata2);
498 		break;
499 	case NF4SOCK:
500 	case NF4FIFO:
501 	case NF4DIR:
502 	default:
503 		break;
504 	}
505 
506 	READ_BUF(4);
507 	READ32(create->cr_namelen);
508 	READ_BUF(create->cr_namelen);
509 	SAVEMEM(create->cr_name, create->cr_namelen);
510 	if ((status = check_filename(create->cr_name, create->cr_namelen, nfserr_inval)))
511 		return status;
512 
513 	status = nfsd4_decode_fattr(argp, create->cr_bmval, &create->cr_iattr,
514 				    &create->cr_acl);
515 	if (status)
516 		goto out;
517 
518 	DECODE_TAIL;
519 }
520 
521 static inline __be32
522 nfsd4_decode_delegreturn(struct nfsd4_compoundargs *argp, struct nfsd4_delegreturn *dr)
523 {
524 	return nfsd4_decode_stateid(argp, &dr->dr_stateid);
525 }
526 
527 static inline __be32
528 nfsd4_decode_getattr(struct nfsd4_compoundargs *argp, struct nfsd4_getattr *getattr)
529 {
530 	return nfsd4_decode_bitmap(argp, getattr->ga_bmval);
531 }
532 
533 static __be32
534 nfsd4_decode_link(struct nfsd4_compoundargs *argp, struct nfsd4_link *link)
535 {
536 	DECODE_HEAD;
537 
538 	READ_BUF(4);
539 	READ32(link->li_namelen);
540 	READ_BUF(link->li_namelen);
541 	SAVEMEM(link->li_name, link->li_namelen);
542 	if ((status = check_filename(link->li_name, link->li_namelen, nfserr_inval)))
543 		return status;
544 
545 	DECODE_TAIL;
546 }
547 
548 static __be32
549 nfsd4_decode_lock(struct nfsd4_compoundargs *argp, struct nfsd4_lock *lock)
550 {
551 	DECODE_HEAD;
552 
553 	/*
554 	* type, reclaim(boolean), offset, length, new_lock_owner(boolean)
555 	*/
556 	READ_BUF(28);
557 	READ32(lock->lk_type);
558 	if ((lock->lk_type < NFS4_READ_LT) || (lock->lk_type > NFS4_WRITEW_LT))
559 		goto xdr_error;
560 	READ32(lock->lk_reclaim);
561 	READ64(lock->lk_offset);
562 	READ64(lock->lk_length);
563 	READ32(lock->lk_is_new);
564 
565 	if (lock->lk_is_new) {
566 		READ_BUF(4);
567 		READ32(lock->lk_new_open_seqid);
568 		status = nfsd4_decode_stateid(argp, &lock->lk_new_open_stateid);
569 		if (status)
570 			return status;
571 		READ_BUF(8 + sizeof(clientid_t));
572 		READ32(lock->lk_new_lock_seqid);
573 		COPYMEM(&lock->lk_new_clientid, sizeof(clientid_t));
574 		READ32(lock->lk_new_owner.len);
575 		READ_BUF(lock->lk_new_owner.len);
576 		READMEM(lock->lk_new_owner.data, lock->lk_new_owner.len);
577 	} else {
578 		status = nfsd4_decode_stateid(argp, &lock->lk_old_lock_stateid);
579 		if (status)
580 			return status;
581 		READ_BUF(4);
582 		READ32(lock->lk_old_lock_seqid);
583 	}
584 
585 	DECODE_TAIL;
586 }
587 
588 static __be32
589 nfsd4_decode_lockt(struct nfsd4_compoundargs *argp, struct nfsd4_lockt *lockt)
590 {
591 	DECODE_HEAD;
592 
593 	READ_BUF(32);
594 	READ32(lockt->lt_type);
595 	if((lockt->lt_type < NFS4_READ_LT) || (lockt->lt_type > NFS4_WRITEW_LT))
596 		goto xdr_error;
597 	READ64(lockt->lt_offset);
598 	READ64(lockt->lt_length);
599 	COPYMEM(&lockt->lt_clientid, 8);
600 	READ32(lockt->lt_owner.len);
601 	READ_BUF(lockt->lt_owner.len);
602 	READMEM(lockt->lt_owner.data, lockt->lt_owner.len);
603 
604 	DECODE_TAIL;
605 }
606 
607 static __be32
608 nfsd4_decode_locku(struct nfsd4_compoundargs *argp, struct nfsd4_locku *locku)
609 {
610 	DECODE_HEAD;
611 
612 	READ_BUF(8);
613 	READ32(locku->lu_type);
614 	if ((locku->lu_type < NFS4_READ_LT) || (locku->lu_type > NFS4_WRITEW_LT))
615 		goto xdr_error;
616 	READ32(locku->lu_seqid);
617 	status = nfsd4_decode_stateid(argp, &locku->lu_stateid);
618 	if (status)
619 		return status;
620 	READ_BUF(16);
621 	READ64(locku->lu_offset);
622 	READ64(locku->lu_length);
623 
624 	DECODE_TAIL;
625 }
626 
627 static __be32
628 nfsd4_decode_lookup(struct nfsd4_compoundargs *argp, struct nfsd4_lookup *lookup)
629 {
630 	DECODE_HEAD;
631 
632 	READ_BUF(4);
633 	READ32(lookup->lo_len);
634 	READ_BUF(lookup->lo_len);
635 	SAVEMEM(lookup->lo_name, lookup->lo_len);
636 	if ((status = check_filename(lookup->lo_name, lookup->lo_len, nfserr_noent)))
637 		return status;
638 
639 	DECODE_TAIL;
640 }
641 
642 static __be32 nfsd4_decode_share_access(struct nfsd4_compoundargs *argp, u32 *x)
643 {
644 	__be32 *p;
645 	u32 w;
646 
647 	READ_BUF(4);
648 	READ32(w);
649 	*x = w;
650 	switch (w & NFS4_SHARE_ACCESS_MASK) {
651 	case NFS4_SHARE_ACCESS_READ:
652 	case NFS4_SHARE_ACCESS_WRITE:
653 	case NFS4_SHARE_ACCESS_BOTH:
654 		break;
655 	default:
656 		return nfserr_bad_xdr;
657 	}
658 	w &= ~NFS4_SHARE_ACCESS_MASK;
659 	if (!w)
660 		return nfs_ok;
661 	if (!argp->minorversion)
662 		return nfserr_bad_xdr;
663 	switch (w & NFS4_SHARE_WANT_MASK) {
664 	case NFS4_SHARE_WANT_NO_PREFERENCE:
665 	case NFS4_SHARE_WANT_READ_DELEG:
666 	case NFS4_SHARE_WANT_WRITE_DELEG:
667 	case NFS4_SHARE_WANT_ANY_DELEG:
668 	case NFS4_SHARE_WANT_NO_DELEG:
669 	case NFS4_SHARE_WANT_CANCEL:
670 		break;
671 	default:
672 		return nfserr_bad_xdr;
673 	}
674 	w &= ~NFS4_SHARE_WANT_MASK;
675 	if (!w)
676 		return nfs_ok;
677 	switch (w) {
678 	case NFS4_SHARE_SIGNAL_DELEG_WHEN_RESRC_AVAIL:
679 	case NFS4_SHARE_PUSH_DELEG_WHEN_UNCONTENDED:
680 	case (NFS4_SHARE_SIGNAL_DELEG_WHEN_RESRC_AVAIL |
681 	      NFS4_SHARE_PUSH_DELEG_WHEN_UNCONTENDED):
682 		return nfs_ok;
683 	}
684 xdr_error:
685 	return nfserr_bad_xdr;
686 }
687 
688 static __be32 nfsd4_decode_share_deny(struct nfsd4_compoundargs *argp, u32 *x)
689 {
690 	__be32 *p;
691 
692 	READ_BUF(4);
693 	READ32(*x);
694 	/* Note: unlinke access bits, deny bits may be zero. */
695 	if (*x & ~NFS4_SHARE_DENY_BOTH)
696 		return nfserr_bad_xdr;
697 	return nfs_ok;
698 xdr_error:
699 	return nfserr_bad_xdr;
700 }
701 
702 static __be32 nfsd4_decode_opaque(struct nfsd4_compoundargs *argp, struct xdr_netobj *o)
703 {
704 	__be32 *p;
705 
706 	READ_BUF(4);
707 	READ32(o->len);
708 
709 	if (o->len == 0 || o->len > NFS4_OPAQUE_LIMIT)
710 		return nfserr_bad_xdr;
711 
712 	READ_BUF(o->len);
713 	SAVEMEM(o->data, o->len);
714 	return nfs_ok;
715 xdr_error:
716 	return nfserr_bad_xdr;
717 }
718 
719 static __be32
720 nfsd4_decode_open(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
721 {
722 	DECODE_HEAD;
723 
724 	memset(open->op_bmval, 0, sizeof(open->op_bmval));
725 	open->op_iattr.ia_valid = 0;
726 	open->op_openowner = NULL;
727 
728 	/* seqid, share_access, share_deny, clientid, ownerlen */
729 	READ_BUF(4);
730 	READ32(open->op_seqid);
731 	status = nfsd4_decode_share_access(argp, &open->op_share_access);
732 	if (status)
733 		goto xdr_error;
734 	status = nfsd4_decode_share_deny(argp, &open->op_share_deny);
735 	if (status)
736 		goto xdr_error;
737 	READ_BUF(sizeof(clientid_t));
738 	COPYMEM(&open->op_clientid, sizeof(clientid_t));
739 	status = nfsd4_decode_opaque(argp, &open->op_owner);
740 	if (status)
741 		goto xdr_error;
742 	READ_BUF(4);
743 	READ32(open->op_create);
744 	switch (open->op_create) {
745 	case NFS4_OPEN_NOCREATE:
746 		break;
747 	case NFS4_OPEN_CREATE:
748 		READ_BUF(4);
749 		READ32(open->op_createmode);
750 		switch (open->op_createmode) {
751 		case NFS4_CREATE_UNCHECKED:
752 		case NFS4_CREATE_GUARDED:
753 			status = nfsd4_decode_fattr(argp, open->op_bmval,
754 				&open->op_iattr, &open->op_acl);
755 			if (status)
756 				goto out;
757 			break;
758 		case NFS4_CREATE_EXCLUSIVE:
759 			READ_BUF(8);
760 			COPYMEM(open->op_verf.data, 8);
761 			break;
762 		case NFS4_CREATE_EXCLUSIVE4_1:
763 			if (argp->minorversion < 1)
764 				goto xdr_error;
765 			READ_BUF(8);
766 			COPYMEM(open->op_verf.data, 8);
767 			status = nfsd4_decode_fattr(argp, open->op_bmval,
768 				&open->op_iattr, &open->op_acl);
769 			if (status)
770 				goto out;
771 			break;
772 		default:
773 			goto xdr_error;
774 		}
775 		break;
776 	default:
777 		goto xdr_error;
778 	}
779 
780 	/* open_claim */
781 	READ_BUF(4);
782 	READ32(open->op_claim_type);
783 	switch (open->op_claim_type) {
784 	case NFS4_OPEN_CLAIM_NULL:
785 	case NFS4_OPEN_CLAIM_DELEGATE_PREV:
786 		READ_BUF(4);
787 		READ32(open->op_fname.len);
788 		READ_BUF(open->op_fname.len);
789 		SAVEMEM(open->op_fname.data, open->op_fname.len);
790 		if ((status = check_filename(open->op_fname.data, open->op_fname.len, nfserr_inval)))
791 			return status;
792 		break;
793 	case NFS4_OPEN_CLAIM_PREVIOUS:
794 		READ_BUF(4);
795 		READ32(open->op_delegate_type);
796 		break;
797 	case NFS4_OPEN_CLAIM_DELEGATE_CUR:
798 		status = nfsd4_decode_stateid(argp, &open->op_delegate_stateid);
799 		if (status)
800 			return status;
801 		READ_BUF(4);
802 		READ32(open->op_fname.len);
803 		READ_BUF(open->op_fname.len);
804 		SAVEMEM(open->op_fname.data, open->op_fname.len);
805 		if ((status = check_filename(open->op_fname.data, open->op_fname.len, nfserr_inval)))
806 			return status;
807 		break;
808 	case NFS4_OPEN_CLAIM_FH:
809 	case NFS4_OPEN_CLAIM_DELEG_PREV_FH:
810 		if (argp->minorversion < 1)
811 			goto xdr_error;
812 		/* void */
813 		break;
814 	case NFS4_OPEN_CLAIM_DELEG_CUR_FH:
815 		if (argp->minorversion < 1)
816 			goto xdr_error;
817 		status = nfsd4_decode_stateid(argp, &open->op_delegate_stateid);
818 		if (status)
819 			return status;
820 		break;
821 	default:
822 		goto xdr_error;
823 	}
824 
825 	DECODE_TAIL;
826 }
827 
828 static __be32
829 nfsd4_decode_open_confirm(struct nfsd4_compoundargs *argp, struct nfsd4_open_confirm *open_conf)
830 {
831 	DECODE_HEAD;
832 
833 	status = nfsd4_decode_stateid(argp, &open_conf->oc_req_stateid);
834 	if (status)
835 		return status;
836 	READ_BUF(4);
837 	READ32(open_conf->oc_seqid);
838 
839 	DECODE_TAIL;
840 }
841 
842 static __be32
843 nfsd4_decode_open_downgrade(struct nfsd4_compoundargs *argp, struct nfsd4_open_downgrade *open_down)
844 {
845 	DECODE_HEAD;
846 
847 	status = nfsd4_decode_stateid(argp, &open_down->od_stateid);
848 	if (status)
849 		return status;
850 	READ_BUF(4);
851 	READ32(open_down->od_seqid);
852 	status = nfsd4_decode_share_access(argp, &open_down->od_share_access);
853 	if (status)
854 		return status;
855 	status = nfsd4_decode_share_deny(argp, &open_down->od_share_deny);
856 	if (status)
857 		return status;
858 	DECODE_TAIL;
859 }
860 
861 static __be32
862 nfsd4_decode_putfh(struct nfsd4_compoundargs *argp, struct nfsd4_putfh *putfh)
863 {
864 	DECODE_HEAD;
865 
866 	READ_BUF(4);
867 	READ32(putfh->pf_fhlen);
868 	if (putfh->pf_fhlen > NFS4_FHSIZE)
869 		goto xdr_error;
870 	READ_BUF(putfh->pf_fhlen);
871 	SAVEMEM(putfh->pf_fhval, putfh->pf_fhlen);
872 
873 	DECODE_TAIL;
874 }
875 
876 static __be32
877 nfsd4_decode_read(struct nfsd4_compoundargs *argp, struct nfsd4_read *read)
878 {
879 	DECODE_HEAD;
880 
881 	status = nfsd4_decode_stateid(argp, &read->rd_stateid);
882 	if (status)
883 		return status;
884 	READ_BUF(12);
885 	READ64(read->rd_offset);
886 	READ32(read->rd_length);
887 
888 	DECODE_TAIL;
889 }
890 
891 static __be32
892 nfsd4_decode_readdir(struct nfsd4_compoundargs *argp, struct nfsd4_readdir *readdir)
893 {
894 	DECODE_HEAD;
895 
896 	READ_BUF(24);
897 	READ64(readdir->rd_cookie);
898 	COPYMEM(readdir->rd_verf.data, sizeof(readdir->rd_verf.data));
899 	READ32(readdir->rd_dircount);    /* just in case you needed a useless field... */
900 	READ32(readdir->rd_maxcount);
901 	if ((status = nfsd4_decode_bitmap(argp, readdir->rd_bmval)))
902 		goto out;
903 
904 	DECODE_TAIL;
905 }
906 
907 static __be32
908 nfsd4_decode_remove(struct nfsd4_compoundargs *argp, struct nfsd4_remove *remove)
909 {
910 	DECODE_HEAD;
911 
912 	READ_BUF(4);
913 	READ32(remove->rm_namelen);
914 	READ_BUF(remove->rm_namelen);
915 	SAVEMEM(remove->rm_name, remove->rm_namelen);
916 	if ((status = check_filename(remove->rm_name, remove->rm_namelen, nfserr_noent)))
917 		return status;
918 
919 	DECODE_TAIL;
920 }
921 
922 static __be32
923 nfsd4_decode_rename(struct nfsd4_compoundargs *argp, struct nfsd4_rename *rename)
924 {
925 	DECODE_HEAD;
926 
927 	READ_BUF(4);
928 	READ32(rename->rn_snamelen);
929 	READ_BUF(rename->rn_snamelen + 4);
930 	SAVEMEM(rename->rn_sname, rename->rn_snamelen);
931 	READ32(rename->rn_tnamelen);
932 	READ_BUF(rename->rn_tnamelen);
933 	SAVEMEM(rename->rn_tname, rename->rn_tnamelen);
934 	if ((status = check_filename(rename->rn_sname, rename->rn_snamelen, nfserr_noent)))
935 		return status;
936 	if ((status = check_filename(rename->rn_tname, rename->rn_tnamelen, nfserr_inval)))
937 		return status;
938 
939 	DECODE_TAIL;
940 }
941 
942 static __be32
943 nfsd4_decode_renew(struct nfsd4_compoundargs *argp, clientid_t *clientid)
944 {
945 	DECODE_HEAD;
946 
947 	READ_BUF(sizeof(clientid_t));
948 	COPYMEM(clientid, sizeof(clientid_t));
949 
950 	DECODE_TAIL;
951 }
952 
953 static __be32
954 nfsd4_decode_secinfo(struct nfsd4_compoundargs *argp,
955 		     struct nfsd4_secinfo *secinfo)
956 {
957 	DECODE_HEAD;
958 
959 	READ_BUF(4);
960 	READ32(secinfo->si_namelen);
961 	READ_BUF(secinfo->si_namelen);
962 	SAVEMEM(secinfo->si_name, secinfo->si_namelen);
963 	status = check_filename(secinfo->si_name, secinfo->si_namelen,
964 								nfserr_noent);
965 	if (status)
966 		return status;
967 	DECODE_TAIL;
968 }
969 
970 static __be32
971 nfsd4_decode_secinfo_no_name(struct nfsd4_compoundargs *argp,
972 		     struct nfsd4_secinfo_no_name *sin)
973 {
974 	DECODE_HEAD;
975 
976 	READ_BUF(4);
977 	READ32(sin->sin_style);
978 	DECODE_TAIL;
979 }
980 
981 static __be32
982 nfsd4_decode_setattr(struct nfsd4_compoundargs *argp, struct nfsd4_setattr *setattr)
983 {
984 	__be32 status;
985 
986 	status = nfsd4_decode_stateid(argp, &setattr->sa_stateid);
987 	if (status)
988 		return status;
989 	return nfsd4_decode_fattr(argp, setattr->sa_bmval, &setattr->sa_iattr,
990 				  &setattr->sa_acl);
991 }
992 
993 static __be32
994 nfsd4_decode_setclientid(struct nfsd4_compoundargs *argp, struct nfsd4_setclientid *setclientid)
995 {
996 	DECODE_HEAD;
997 
998 	READ_BUF(8);
999 	COPYMEM(setclientid->se_verf.data, 8);
1000 
1001 	status = nfsd4_decode_opaque(argp, &setclientid->se_name);
1002 	if (status)
1003 		return nfserr_bad_xdr;
1004 	READ_BUF(8);
1005 	READ32(setclientid->se_callback_prog);
1006 	READ32(setclientid->se_callback_netid_len);
1007 
1008 	READ_BUF(setclientid->se_callback_netid_len + 4);
1009 	SAVEMEM(setclientid->se_callback_netid_val, setclientid->se_callback_netid_len);
1010 	READ32(setclientid->se_callback_addr_len);
1011 
1012 	READ_BUF(setclientid->se_callback_addr_len + 4);
1013 	SAVEMEM(setclientid->se_callback_addr_val, setclientid->se_callback_addr_len);
1014 	READ32(setclientid->se_callback_ident);
1015 
1016 	DECODE_TAIL;
1017 }
1018 
1019 static __be32
1020 nfsd4_decode_setclientid_confirm(struct nfsd4_compoundargs *argp, struct nfsd4_setclientid_confirm *scd_c)
1021 {
1022 	DECODE_HEAD;
1023 
1024 	READ_BUF(8 + sizeof(nfs4_verifier));
1025 	COPYMEM(&scd_c->sc_clientid, 8);
1026 	COPYMEM(&scd_c->sc_confirm, sizeof(nfs4_verifier));
1027 
1028 	DECODE_TAIL;
1029 }
1030 
1031 /* Also used for NVERIFY */
1032 static __be32
1033 nfsd4_decode_verify(struct nfsd4_compoundargs *argp, struct nfsd4_verify *verify)
1034 {
1035 #if 0
1036 	struct nfsd4_compoundargs save = {
1037 		.p = argp->p,
1038 		.end = argp->end,
1039 		.rqstp = argp->rqstp,
1040 	};
1041 	u32             ve_bmval[2];
1042 	struct iattr    ve_iattr;           /* request */
1043 	struct nfs4_acl *ve_acl;            /* request */
1044 #endif
1045 	DECODE_HEAD;
1046 
1047 	if ((status = nfsd4_decode_bitmap(argp, verify->ve_bmval)))
1048 		goto out;
1049 
1050 	/* For convenience's sake, we compare raw xdr'd attributes in
1051 	 * nfsd4_proc_verify; however we still decode here just to return
1052 	 * correct error in case of bad xdr. */
1053 #if 0
1054 	status = nfsd4_decode_fattr(ve_bmval, &ve_iattr, &ve_acl);
1055 	if (status == nfserr_inval) {
1056 		status = nfserrno(status);
1057 		goto out;
1058 	}
1059 #endif
1060 	READ_BUF(4);
1061 	READ32(verify->ve_attrlen);
1062 	READ_BUF(verify->ve_attrlen);
1063 	SAVEMEM(verify->ve_attrval, verify->ve_attrlen);
1064 
1065 	DECODE_TAIL;
1066 }
1067 
1068 static __be32
1069 nfsd4_decode_write(struct nfsd4_compoundargs *argp, struct nfsd4_write *write)
1070 {
1071 	int avail;
1072 	int v;
1073 	int len;
1074 	DECODE_HEAD;
1075 
1076 	status = nfsd4_decode_stateid(argp, &write->wr_stateid);
1077 	if (status)
1078 		return status;
1079 	READ_BUF(16);
1080 	READ64(write->wr_offset);
1081 	READ32(write->wr_stable_how);
1082 	if (write->wr_stable_how > 2)
1083 		goto xdr_error;
1084 	READ32(write->wr_buflen);
1085 
1086 	/* Sorry .. no magic macros for this.. *
1087 	 * READ_BUF(write->wr_buflen);
1088 	 * SAVEMEM(write->wr_buf, write->wr_buflen);
1089 	 */
1090 	avail = (char*)argp->end - (char*)argp->p;
1091 	if (avail + argp->pagelen < write->wr_buflen) {
1092 		dprintk("NFSD: xdr error (%s:%d)\n",
1093 				__FILE__, __LINE__);
1094 		goto xdr_error;
1095 	}
1096 	argp->rqstp->rq_vec[0].iov_base = p;
1097 	argp->rqstp->rq_vec[0].iov_len = avail;
1098 	v = 0;
1099 	len = write->wr_buflen;
1100 	while (len > argp->rqstp->rq_vec[v].iov_len) {
1101 		len -= argp->rqstp->rq_vec[v].iov_len;
1102 		v++;
1103 		argp->rqstp->rq_vec[v].iov_base = page_address(argp->pagelist[0]);
1104 		argp->pagelist++;
1105 		if (argp->pagelen >= PAGE_SIZE) {
1106 			argp->rqstp->rq_vec[v].iov_len = PAGE_SIZE;
1107 			argp->pagelen -= PAGE_SIZE;
1108 		} else {
1109 			argp->rqstp->rq_vec[v].iov_len = argp->pagelen;
1110 			argp->pagelen -= len;
1111 		}
1112 	}
1113 	argp->end = (__be32*) (argp->rqstp->rq_vec[v].iov_base + argp->rqstp->rq_vec[v].iov_len);
1114 	argp->p = (__be32*)  (argp->rqstp->rq_vec[v].iov_base + (XDR_QUADLEN(len) << 2));
1115 	argp->rqstp->rq_vec[v].iov_len = len;
1116 	write->wr_vlen = v+1;
1117 
1118 	DECODE_TAIL;
1119 }
1120 
1121 static __be32
1122 nfsd4_decode_release_lockowner(struct nfsd4_compoundargs *argp, struct nfsd4_release_lockowner *rlockowner)
1123 {
1124 	DECODE_HEAD;
1125 
1126 	READ_BUF(12);
1127 	COPYMEM(&rlockowner->rl_clientid, sizeof(clientid_t));
1128 	READ32(rlockowner->rl_owner.len);
1129 	READ_BUF(rlockowner->rl_owner.len);
1130 	READMEM(rlockowner->rl_owner.data, rlockowner->rl_owner.len);
1131 
1132 	if (argp->minorversion && !zero_clientid(&rlockowner->rl_clientid))
1133 		return nfserr_inval;
1134 	DECODE_TAIL;
1135 }
1136 
1137 static __be32
1138 nfsd4_decode_exchange_id(struct nfsd4_compoundargs *argp,
1139 			 struct nfsd4_exchange_id *exid)
1140 {
1141 	int dummy, tmp;
1142 	DECODE_HEAD;
1143 
1144 	READ_BUF(NFS4_VERIFIER_SIZE);
1145 	COPYMEM(exid->verifier.data, NFS4_VERIFIER_SIZE);
1146 
1147 	status = nfsd4_decode_opaque(argp, &exid->clname);
1148 	if (status)
1149 		return nfserr_bad_xdr;
1150 
1151 	READ_BUF(4);
1152 	READ32(exid->flags);
1153 
1154 	/* Ignore state_protect4_a */
1155 	READ_BUF(4);
1156 	READ32(exid->spa_how);
1157 	switch (exid->spa_how) {
1158 	case SP4_NONE:
1159 		break;
1160 	case SP4_MACH_CRED:
1161 		/* spo_must_enforce */
1162 		READ_BUF(4);
1163 		READ32(dummy);
1164 		READ_BUF(dummy * 4);
1165 		p += dummy;
1166 
1167 		/* spo_must_allow */
1168 		READ_BUF(4);
1169 		READ32(dummy);
1170 		READ_BUF(dummy * 4);
1171 		p += dummy;
1172 		break;
1173 	case SP4_SSV:
1174 		/* ssp_ops */
1175 		READ_BUF(4);
1176 		READ32(dummy);
1177 		READ_BUF(dummy * 4);
1178 		p += dummy;
1179 
1180 		READ_BUF(4);
1181 		READ32(dummy);
1182 		READ_BUF(dummy * 4);
1183 		p += dummy;
1184 
1185 		/* ssp_hash_algs<> */
1186 		READ_BUF(4);
1187 		READ32(tmp);
1188 		while (tmp--) {
1189 			READ_BUF(4);
1190 			READ32(dummy);
1191 			READ_BUF(dummy);
1192 			p += XDR_QUADLEN(dummy);
1193 		}
1194 
1195 		/* ssp_encr_algs<> */
1196 		READ_BUF(4);
1197 		READ32(tmp);
1198 		while (tmp--) {
1199 			READ_BUF(4);
1200 			READ32(dummy);
1201 			READ_BUF(dummy);
1202 			p += XDR_QUADLEN(dummy);
1203 		}
1204 
1205 		/* ssp_window and ssp_num_gss_handles */
1206 		READ_BUF(8);
1207 		READ32(dummy);
1208 		READ32(dummy);
1209 		break;
1210 	default:
1211 		goto xdr_error;
1212 	}
1213 
1214 	/* Ignore Implementation ID */
1215 	READ_BUF(4);    /* nfs_impl_id4 array length */
1216 	READ32(dummy);
1217 
1218 	if (dummy > 1)
1219 		goto xdr_error;
1220 
1221 	if (dummy == 1) {
1222 		/* nii_domain */
1223 		READ_BUF(4);
1224 		READ32(dummy);
1225 		READ_BUF(dummy);
1226 		p += XDR_QUADLEN(dummy);
1227 
1228 		/* nii_name */
1229 		READ_BUF(4);
1230 		READ32(dummy);
1231 		READ_BUF(dummy);
1232 		p += XDR_QUADLEN(dummy);
1233 
1234 		/* nii_date */
1235 		READ_BUF(12);
1236 		p += 3;
1237 	}
1238 	DECODE_TAIL;
1239 }
1240 
1241 static __be32
1242 nfsd4_decode_create_session(struct nfsd4_compoundargs *argp,
1243 			    struct nfsd4_create_session *sess)
1244 {
1245 	DECODE_HEAD;
1246 
1247 	u32 dummy;
1248 	char *machine_name;
1249 	int i;
1250 	int nr_secflavs;
1251 
1252 	READ_BUF(16);
1253 	COPYMEM(&sess->clientid, 8);
1254 	READ32(sess->seqid);
1255 	READ32(sess->flags);
1256 
1257 	/* Fore channel attrs */
1258 	READ_BUF(28);
1259 	READ32(dummy); /* headerpadsz is always 0 */
1260 	READ32(sess->fore_channel.maxreq_sz);
1261 	READ32(sess->fore_channel.maxresp_sz);
1262 	READ32(sess->fore_channel.maxresp_cached);
1263 	READ32(sess->fore_channel.maxops);
1264 	READ32(sess->fore_channel.maxreqs);
1265 	READ32(sess->fore_channel.nr_rdma_attrs);
1266 	if (sess->fore_channel.nr_rdma_attrs == 1) {
1267 		READ_BUF(4);
1268 		READ32(sess->fore_channel.rdma_attrs);
1269 	} else if (sess->fore_channel.nr_rdma_attrs > 1) {
1270 		dprintk("Too many fore channel attr bitmaps!\n");
1271 		goto xdr_error;
1272 	}
1273 
1274 	/* Back channel attrs */
1275 	READ_BUF(28);
1276 	READ32(dummy); /* headerpadsz is always 0 */
1277 	READ32(sess->back_channel.maxreq_sz);
1278 	READ32(sess->back_channel.maxresp_sz);
1279 	READ32(sess->back_channel.maxresp_cached);
1280 	READ32(sess->back_channel.maxops);
1281 	READ32(sess->back_channel.maxreqs);
1282 	READ32(sess->back_channel.nr_rdma_attrs);
1283 	if (sess->back_channel.nr_rdma_attrs == 1) {
1284 		READ_BUF(4);
1285 		READ32(sess->back_channel.rdma_attrs);
1286 	} else if (sess->back_channel.nr_rdma_attrs > 1) {
1287 		dprintk("Too many back channel attr bitmaps!\n");
1288 		goto xdr_error;
1289 	}
1290 
1291 	READ_BUF(8);
1292 	READ32(sess->callback_prog);
1293 
1294 	/* callback_sec_params4 */
1295 	READ32(nr_secflavs);
1296 	for (i = 0; i < nr_secflavs; ++i) {
1297 		READ_BUF(4);
1298 		READ32(dummy);
1299 		switch (dummy) {
1300 		case RPC_AUTH_NULL:
1301 			/* Nothing to read */
1302 			break;
1303 		case RPC_AUTH_UNIX:
1304 			READ_BUF(8);
1305 			/* stamp */
1306 			READ32(dummy);
1307 
1308 			/* machine name */
1309 			READ32(dummy);
1310 			READ_BUF(dummy);
1311 			SAVEMEM(machine_name, dummy);
1312 
1313 			/* uid, gid */
1314 			READ_BUF(8);
1315 			READ32(sess->uid);
1316 			READ32(sess->gid);
1317 
1318 			/* more gids */
1319 			READ_BUF(4);
1320 			READ32(dummy);
1321 			READ_BUF(dummy * 4);
1322 			break;
1323 		case RPC_AUTH_GSS:
1324 			dprintk("RPC_AUTH_GSS callback secflavor "
1325 				"not supported!\n");
1326 			READ_BUF(8);
1327 			/* gcbp_service */
1328 			READ32(dummy);
1329 			/* gcbp_handle_from_server */
1330 			READ32(dummy);
1331 			READ_BUF(dummy);
1332 			p += XDR_QUADLEN(dummy);
1333 			/* gcbp_handle_from_client */
1334 			READ_BUF(4);
1335 			READ32(dummy);
1336 			READ_BUF(dummy);
1337 			break;
1338 		default:
1339 			dprintk("Illegal callback secflavor\n");
1340 			return nfserr_inval;
1341 		}
1342 	}
1343 	DECODE_TAIL;
1344 }
1345 
1346 static __be32
1347 nfsd4_decode_destroy_session(struct nfsd4_compoundargs *argp,
1348 			     struct nfsd4_destroy_session *destroy_session)
1349 {
1350 	DECODE_HEAD;
1351 	READ_BUF(NFS4_MAX_SESSIONID_LEN);
1352 	COPYMEM(destroy_session->sessionid.data, NFS4_MAX_SESSIONID_LEN);
1353 
1354 	DECODE_TAIL;
1355 }
1356 
1357 static __be32
1358 nfsd4_decode_free_stateid(struct nfsd4_compoundargs *argp,
1359 			  struct nfsd4_free_stateid *free_stateid)
1360 {
1361 	DECODE_HEAD;
1362 
1363 	READ_BUF(sizeof(stateid_t));
1364 	READ32(free_stateid->fr_stateid.si_generation);
1365 	COPYMEM(&free_stateid->fr_stateid.si_opaque, sizeof(stateid_opaque_t));
1366 
1367 	DECODE_TAIL;
1368 }
1369 
1370 static __be32
1371 nfsd4_decode_sequence(struct nfsd4_compoundargs *argp,
1372 		      struct nfsd4_sequence *seq)
1373 {
1374 	DECODE_HEAD;
1375 
1376 	READ_BUF(NFS4_MAX_SESSIONID_LEN + 16);
1377 	COPYMEM(seq->sessionid.data, NFS4_MAX_SESSIONID_LEN);
1378 	READ32(seq->seqid);
1379 	READ32(seq->slotid);
1380 	READ32(seq->maxslots);
1381 	READ32(seq->cachethis);
1382 
1383 	DECODE_TAIL;
1384 }
1385 
1386 static __be32
1387 nfsd4_decode_test_stateid(struct nfsd4_compoundargs *argp, struct nfsd4_test_stateid *test_stateid)
1388 {
1389 	unsigned int nbytes;
1390 	stateid_t si;
1391 	int i;
1392 	__be32 *p;
1393 	__be32 status;
1394 
1395 	READ_BUF(4);
1396 	test_stateid->ts_num_ids = ntohl(*p++);
1397 
1398 	nbytes = test_stateid->ts_num_ids * sizeof(stateid_t);
1399 	if (nbytes > (u32)((char *)argp->end - (char *)argp->p))
1400 		goto xdr_error;
1401 
1402 	test_stateid->ts_saved_args = argp;
1403 	save_buf(argp, &test_stateid->ts_savedp);
1404 
1405 	for (i = 0; i < test_stateid->ts_num_ids; i++) {
1406 		status = nfsd4_decode_stateid(argp, &si);
1407 		if (status)
1408 			return status;
1409 	}
1410 
1411 	status = 0;
1412 out:
1413 	return status;
1414 xdr_error:
1415 	dprintk("NFSD: xdr error (%s:%d)\n", __FILE__, __LINE__);
1416 	status = nfserr_bad_xdr;
1417 	goto out;
1418 }
1419 
1420 static __be32 nfsd4_decode_destroy_clientid(struct nfsd4_compoundargs *argp, struct nfsd4_destroy_clientid *dc)
1421 {
1422 	DECODE_HEAD;
1423 
1424 	READ_BUF(8);
1425 	COPYMEM(&dc->clientid, 8);
1426 
1427 	DECODE_TAIL;
1428 }
1429 
1430 static __be32 nfsd4_decode_reclaim_complete(struct nfsd4_compoundargs *argp, struct nfsd4_reclaim_complete *rc)
1431 {
1432 	DECODE_HEAD;
1433 
1434 	READ_BUF(4);
1435 	READ32(rc->rca_one_fs);
1436 
1437 	DECODE_TAIL;
1438 }
1439 
1440 static __be32
1441 nfsd4_decode_noop(struct nfsd4_compoundargs *argp, void *p)
1442 {
1443 	return nfs_ok;
1444 }
1445 
1446 static __be32
1447 nfsd4_decode_notsupp(struct nfsd4_compoundargs *argp, void *p)
1448 {
1449 	return nfserr_notsupp;
1450 }
1451 
1452 typedef __be32(*nfsd4_dec)(struct nfsd4_compoundargs *argp, void *);
1453 
1454 static nfsd4_dec nfsd4_dec_ops[] = {
1455 	[OP_ACCESS]		= (nfsd4_dec)nfsd4_decode_access,
1456 	[OP_CLOSE]		= (nfsd4_dec)nfsd4_decode_close,
1457 	[OP_COMMIT]		= (nfsd4_dec)nfsd4_decode_commit,
1458 	[OP_CREATE]		= (nfsd4_dec)nfsd4_decode_create,
1459 	[OP_DELEGPURGE]		= (nfsd4_dec)nfsd4_decode_notsupp,
1460 	[OP_DELEGRETURN]	= (nfsd4_dec)nfsd4_decode_delegreturn,
1461 	[OP_GETATTR]		= (nfsd4_dec)nfsd4_decode_getattr,
1462 	[OP_GETFH]		= (nfsd4_dec)nfsd4_decode_noop,
1463 	[OP_LINK]		= (nfsd4_dec)nfsd4_decode_link,
1464 	[OP_LOCK]		= (nfsd4_dec)nfsd4_decode_lock,
1465 	[OP_LOCKT]		= (nfsd4_dec)nfsd4_decode_lockt,
1466 	[OP_LOCKU]		= (nfsd4_dec)nfsd4_decode_locku,
1467 	[OP_LOOKUP]		= (nfsd4_dec)nfsd4_decode_lookup,
1468 	[OP_LOOKUPP]		= (nfsd4_dec)nfsd4_decode_noop,
1469 	[OP_NVERIFY]		= (nfsd4_dec)nfsd4_decode_verify,
1470 	[OP_OPEN]		= (nfsd4_dec)nfsd4_decode_open,
1471 	[OP_OPENATTR]		= (nfsd4_dec)nfsd4_decode_notsupp,
1472 	[OP_OPEN_CONFIRM]	= (nfsd4_dec)nfsd4_decode_open_confirm,
1473 	[OP_OPEN_DOWNGRADE]	= (nfsd4_dec)nfsd4_decode_open_downgrade,
1474 	[OP_PUTFH]		= (nfsd4_dec)nfsd4_decode_putfh,
1475 	[OP_PUTPUBFH]		= (nfsd4_dec)nfsd4_decode_noop,
1476 	[OP_PUTROOTFH]		= (nfsd4_dec)nfsd4_decode_noop,
1477 	[OP_READ]		= (nfsd4_dec)nfsd4_decode_read,
1478 	[OP_READDIR]		= (nfsd4_dec)nfsd4_decode_readdir,
1479 	[OP_READLINK]		= (nfsd4_dec)nfsd4_decode_noop,
1480 	[OP_REMOVE]		= (nfsd4_dec)nfsd4_decode_remove,
1481 	[OP_RENAME]		= (nfsd4_dec)nfsd4_decode_rename,
1482 	[OP_RENEW]		= (nfsd4_dec)nfsd4_decode_renew,
1483 	[OP_RESTOREFH]		= (nfsd4_dec)nfsd4_decode_noop,
1484 	[OP_SAVEFH]		= (nfsd4_dec)nfsd4_decode_noop,
1485 	[OP_SECINFO]		= (nfsd4_dec)nfsd4_decode_secinfo,
1486 	[OP_SETATTR]		= (nfsd4_dec)nfsd4_decode_setattr,
1487 	[OP_SETCLIENTID]	= (nfsd4_dec)nfsd4_decode_setclientid,
1488 	[OP_SETCLIENTID_CONFIRM] = (nfsd4_dec)nfsd4_decode_setclientid_confirm,
1489 	[OP_VERIFY]		= (nfsd4_dec)nfsd4_decode_verify,
1490 	[OP_WRITE]		= (nfsd4_dec)nfsd4_decode_write,
1491 	[OP_RELEASE_LOCKOWNER]	= (nfsd4_dec)nfsd4_decode_release_lockowner,
1492 };
1493 
1494 static nfsd4_dec nfsd41_dec_ops[] = {
1495 	[OP_ACCESS]		= (nfsd4_dec)nfsd4_decode_access,
1496 	[OP_CLOSE]		= (nfsd4_dec)nfsd4_decode_close,
1497 	[OP_COMMIT]		= (nfsd4_dec)nfsd4_decode_commit,
1498 	[OP_CREATE]		= (nfsd4_dec)nfsd4_decode_create,
1499 	[OP_DELEGPURGE]		= (nfsd4_dec)nfsd4_decode_notsupp,
1500 	[OP_DELEGRETURN]	= (nfsd4_dec)nfsd4_decode_delegreturn,
1501 	[OP_GETATTR]		= (nfsd4_dec)nfsd4_decode_getattr,
1502 	[OP_GETFH]		= (nfsd4_dec)nfsd4_decode_noop,
1503 	[OP_LINK]		= (nfsd4_dec)nfsd4_decode_link,
1504 	[OP_LOCK]		= (nfsd4_dec)nfsd4_decode_lock,
1505 	[OP_LOCKT]		= (nfsd4_dec)nfsd4_decode_lockt,
1506 	[OP_LOCKU]		= (nfsd4_dec)nfsd4_decode_locku,
1507 	[OP_LOOKUP]		= (nfsd4_dec)nfsd4_decode_lookup,
1508 	[OP_LOOKUPP]		= (nfsd4_dec)nfsd4_decode_noop,
1509 	[OP_NVERIFY]		= (nfsd4_dec)nfsd4_decode_verify,
1510 	[OP_OPEN]		= (nfsd4_dec)nfsd4_decode_open,
1511 	[OP_OPENATTR]		= (nfsd4_dec)nfsd4_decode_notsupp,
1512 	[OP_OPEN_CONFIRM]	= (nfsd4_dec)nfsd4_decode_notsupp,
1513 	[OP_OPEN_DOWNGRADE]	= (nfsd4_dec)nfsd4_decode_open_downgrade,
1514 	[OP_PUTFH]		= (nfsd4_dec)nfsd4_decode_putfh,
1515 	[OP_PUTPUBFH]		= (nfsd4_dec)nfsd4_decode_notsupp,
1516 	[OP_PUTROOTFH]		= (nfsd4_dec)nfsd4_decode_noop,
1517 	[OP_READ]		= (nfsd4_dec)nfsd4_decode_read,
1518 	[OP_READDIR]		= (nfsd4_dec)nfsd4_decode_readdir,
1519 	[OP_READLINK]		= (nfsd4_dec)nfsd4_decode_noop,
1520 	[OP_REMOVE]		= (nfsd4_dec)nfsd4_decode_remove,
1521 	[OP_RENAME]		= (nfsd4_dec)nfsd4_decode_rename,
1522 	[OP_RENEW]		= (nfsd4_dec)nfsd4_decode_notsupp,
1523 	[OP_RESTOREFH]		= (nfsd4_dec)nfsd4_decode_noop,
1524 	[OP_SAVEFH]		= (nfsd4_dec)nfsd4_decode_noop,
1525 	[OP_SECINFO]		= (nfsd4_dec)nfsd4_decode_secinfo,
1526 	[OP_SETATTR]		= (nfsd4_dec)nfsd4_decode_setattr,
1527 	[OP_SETCLIENTID]	= (nfsd4_dec)nfsd4_decode_notsupp,
1528 	[OP_SETCLIENTID_CONFIRM]= (nfsd4_dec)nfsd4_decode_notsupp,
1529 	[OP_VERIFY]		= (nfsd4_dec)nfsd4_decode_verify,
1530 	[OP_WRITE]		= (nfsd4_dec)nfsd4_decode_write,
1531 	[OP_RELEASE_LOCKOWNER]	= (nfsd4_dec)nfsd4_decode_notsupp,
1532 
1533 	/* new operations for NFSv4.1 */
1534 	[OP_BACKCHANNEL_CTL]	= (nfsd4_dec)nfsd4_decode_notsupp,
1535 	[OP_BIND_CONN_TO_SESSION]= (nfsd4_dec)nfsd4_decode_bind_conn_to_session,
1536 	[OP_EXCHANGE_ID]	= (nfsd4_dec)nfsd4_decode_exchange_id,
1537 	[OP_CREATE_SESSION]	= (nfsd4_dec)nfsd4_decode_create_session,
1538 	[OP_DESTROY_SESSION]	= (nfsd4_dec)nfsd4_decode_destroy_session,
1539 	[OP_FREE_STATEID]	= (nfsd4_dec)nfsd4_decode_free_stateid,
1540 	[OP_GET_DIR_DELEGATION]	= (nfsd4_dec)nfsd4_decode_notsupp,
1541 	[OP_GETDEVICEINFO]	= (nfsd4_dec)nfsd4_decode_notsupp,
1542 	[OP_GETDEVICELIST]	= (nfsd4_dec)nfsd4_decode_notsupp,
1543 	[OP_LAYOUTCOMMIT]	= (nfsd4_dec)nfsd4_decode_notsupp,
1544 	[OP_LAYOUTGET]		= (nfsd4_dec)nfsd4_decode_notsupp,
1545 	[OP_LAYOUTRETURN]	= (nfsd4_dec)nfsd4_decode_notsupp,
1546 	[OP_SECINFO_NO_NAME]	= (nfsd4_dec)nfsd4_decode_secinfo_no_name,
1547 	[OP_SEQUENCE]		= (nfsd4_dec)nfsd4_decode_sequence,
1548 	[OP_SET_SSV]		= (nfsd4_dec)nfsd4_decode_notsupp,
1549 	[OP_TEST_STATEID]	= (nfsd4_dec)nfsd4_decode_test_stateid,
1550 	[OP_WANT_DELEGATION]	= (nfsd4_dec)nfsd4_decode_notsupp,
1551 	[OP_DESTROY_CLIENTID]	= (nfsd4_dec)nfsd4_decode_destroy_clientid,
1552 	[OP_RECLAIM_COMPLETE]	= (nfsd4_dec)nfsd4_decode_reclaim_complete,
1553 };
1554 
1555 struct nfsd4_minorversion_ops {
1556 	nfsd4_dec *decoders;
1557 	int nops;
1558 };
1559 
1560 static struct nfsd4_minorversion_ops nfsd4_minorversion[] = {
1561 	[0] = { nfsd4_dec_ops, ARRAY_SIZE(nfsd4_dec_ops) },
1562 	[1] = { nfsd41_dec_ops, ARRAY_SIZE(nfsd41_dec_ops) },
1563 };
1564 
1565 static __be32
1566 nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
1567 {
1568 	DECODE_HEAD;
1569 	struct nfsd4_op *op;
1570 	struct nfsd4_minorversion_ops *ops;
1571 	bool cachethis = false;
1572 	int i;
1573 
1574 	/*
1575 	 * XXX: According to spec, we should check the tag
1576 	 * for UTF-8 compliance.  I'm postponing this for
1577 	 * now because it seems that some clients do use
1578 	 * binary tags.
1579 	 */
1580 	READ_BUF(4);
1581 	READ32(argp->taglen);
1582 	READ_BUF(argp->taglen + 8);
1583 	SAVEMEM(argp->tag, argp->taglen);
1584 	READ32(argp->minorversion);
1585 	READ32(argp->opcnt);
1586 
1587 	if (argp->taglen > NFSD4_MAX_TAGLEN)
1588 		goto xdr_error;
1589 	if (argp->opcnt > 100)
1590 		goto xdr_error;
1591 
1592 	if (argp->opcnt > ARRAY_SIZE(argp->iops)) {
1593 		argp->ops = kmalloc(argp->opcnt * sizeof(*argp->ops), GFP_KERNEL);
1594 		if (!argp->ops) {
1595 			argp->ops = argp->iops;
1596 			dprintk("nfsd: couldn't allocate room for COMPOUND\n");
1597 			goto xdr_error;
1598 		}
1599 	}
1600 
1601 	if (argp->minorversion >= ARRAY_SIZE(nfsd4_minorversion))
1602 		argp->opcnt = 0;
1603 
1604 	ops = &nfsd4_minorversion[argp->minorversion];
1605 	for (i = 0; i < argp->opcnt; i++) {
1606 		op = &argp->ops[i];
1607 		op->replay = NULL;
1608 
1609 		/*
1610 		 * We can't use READ_BUF() here because we need to handle
1611 		 * a missing opcode as an OP_WRITE + 1. So we need to check
1612 		 * to see if we're truly at the end of our buffer or if there
1613 		 * is another page we need to flip to.
1614 		 */
1615 
1616 		if (argp->p == argp->end) {
1617 			if (argp->pagelen < 4) {
1618 				/* There isn't an opcode still on the wire */
1619 				op->opnum = OP_WRITE + 1;
1620 				op->status = nfserr_bad_xdr;
1621 				argp->opcnt = i+1;
1622 				break;
1623 			}
1624 
1625 			/*
1626 			 * False alarm. We just hit a page boundary, but there
1627 			 * is still data available.  Move pointer across page
1628 			 * boundary.  *snip from READ_BUF*
1629 			 */
1630 			argp->p = page_address(argp->pagelist[0]);
1631 			argp->pagelist++;
1632 			if (argp->pagelen < PAGE_SIZE) {
1633 				argp->end = argp->p + (argp->pagelen>>2);
1634 				argp->pagelen = 0;
1635 			} else {
1636 				argp->end = argp->p + (PAGE_SIZE>>2);
1637 				argp->pagelen -= PAGE_SIZE;
1638 			}
1639 		}
1640 		op->opnum = ntohl(*argp->p++);
1641 
1642 		if (op->opnum >= FIRST_NFS4_OP && op->opnum <= LAST_NFS4_OP)
1643 			op->status = ops->decoders[op->opnum](argp, &op->u);
1644 		else {
1645 			op->opnum = OP_ILLEGAL;
1646 			op->status = nfserr_op_illegal;
1647 		}
1648 
1649 		if (op->status) {
1650 			argp->opcnt = i+1;
1651 			break;
1652 		}
1653 		/*
1654 		 * We'll try to cache the result in the DRC if any one
1655 		 * op in the compound wants to be cached:
1656 		 */
1657 		cachethis |= nfsd4_cache_this_op(op);
1658 	}
1659 	/* Sessions make the DRC unnecessary: */
1660 	if (argp->minorversion)
1661 		cachethis = false;
1662 	argp->rqstp->rq_cachetype = cachethis ? RC_REPLBUFF : RC_NOCACHE;
1663 
1664 	DECODE_TAIL;
1665 }
1666 
1667 #define WRITE32(n)               *p++ = htonl(n)
1668 #define WRITE64(n)               do {				\
1669 	*p++ = htonl((u32)((n) >> 32));				\
1670 	*p++ = htonl((u32)(n));					\
1671 } while (0)
1672 #define WRITEMEM(ptr,nbytes)     do { if (nbytes > 0) {		\
1673 	*(p + XDR_QUADLEN(nbytes) -1) = 0;                      \
1674 	memcpy(p, ptr, nbytes);					\
1675 	p += XDR_QUADLEN(nbytes);				\
1676 }} while (0)
1677 
1678 static void write32(__be32 **p, u32 n)
1679 {
1680 	*(*p)++ = n;
1681 }
1682 
1683 static void write64(__be32 **p, u64 n)
1684 {
1685 	write32(p, (u32)(n >> 32));
1686 	write32(p, (u32)n);
1687 }
1688 
1689 static void write_change(__be32 **p, struct kstat *stat, struct inode *inode)
1690 {
1691 	if (IS_I_VERSION(inode)) {
1692 		write64(p, inode->i_version);
1693 	} else {
1694 		write32(p, stat->ctime.tv_sec);
1695 		write32(p, stat->ctime.tv_nsec);
1696 	}
1697 }
1698 
1699 static void write_cinfo(__be32 **p, struct nfsd4_change_info *c)
1700 {
1701 	write32(p, c->atomic);
1702 	if (c->change_supported) {
1703 		write64(p, c->before_change);
1704 		write64(p, c->after_change);
1705 	} else {
1706 		write32(p, c->before_ctime_sec);
1707 		write32(p, c->before_ctime_nsec);
1708 		write32(p, c->after_ctime_sec);
1709 		write32(p, c->after_ctime_nsec);
1710 	}
1711 }
1712 
1713 #define RESERVE_SPACE(nbytes)	do {				\
1714 	p = resp->p;						\
1715 	BUG_ON(p + XDR_QUADLEN(nbytes) > resp->end);		\
1716 } while (0)
1717 #define ADJUST_ARGS()		resp->p = p
1718 
1719 /*
1720  * Header routine to setup seqid operation replay cache
1721  */
1722 #define ENCODE_SEQID_OP_HEAD					\
1723 	__be32 *save;						\
1724 								\
1725 	save = resp->p;
1726 
1727 /*
1728  * Routine for encoding the result of a "seqid-mutating" NFSv4 operation.  This
1729  * is where sequence id's are incremented, and the replay cache is filled.
1730  * Note that we increment sequence id's here, at the last moment, so we're sure
1731  * we know whether the error to be returned is a sequence id mutating error.
1732  */
1733 
1734 static void encode_seqid_op_tail(struct nfsd4_compoundres *resp, __be32 *save, __be32 nfserr)
1735 {
1736 	struct nfs4_stateowner *stateowner = resp->cstate.replay_owner;
1737 
1738 	if (seqid_mutating_err(ntohl(nfserr)) && stateowner) {
1739 		stateowner->so_seqid++;
1740 		stateowner->so_replay.rp_status = nfserr;
1741 		stateowner->so_replay.rp_buflen =
1742 			  (char *)resp->p - (char *)save;
1743 		memcpy(stateowner->so_replay.rp_buf, save,
1744 			stateowner->so_replay.rp_buflen);
1745 		nfsd4_purge_closed_stateid(stateowner);
1746 	}
1747 }
1748 
1749 /* Encode as an array of strings the string given with components
1750  * separated @sep.
1751  */
1752 static __be32 nfsd4_encode_components(char sep, char *components,
1753 				   __be32 **pp, int *buflen)
1754 {
1755 	__be32 *p = *pp;
1756 	__be32 *countp = p;
1757 	int strlen, count=0;
1758 	char *str, *end;
1759 
1760 	dprintk("nfsd4_encode_components(%s)\n", components);
1761 	if ((*buflen -= 4) < 0)
1762 		return nfserr_resource;
1763 	WRITE32(0); /* We will fill this in with @count later */
1764 	end = str = components;
1765 	while (*end) {
1766 		for (; *end && (*end != sep); end++)
1767 			; /* Point to end of component */
1768 		strlen = end - str;
1769 		if (strlen) {
1770 			if ((*buflen -= ((XDR_QUADLEN(strlen) << 2) + 4)) < 0)
1771 				return nfserr_resource;
1772 			WRITE32(strlen);
1773 			WRITEMEM(str, strlen);
1774 			count++;
1775 		}
1776 		else
1777 			end++;
1778 		str = end;
1779 	}
1780 	*pp = p;
1781 	p = countp;
1782 	WRITE32(count);
1783 	return 0;
1784 }
1785 
1786 /*
1787  * encode a location element of a fs_locations structure
1788  */
1789 static __be32 nfsd4_encode_fs_location4(struct nfsd4_fs_location *location,
1790 				    __be32 **pp, int *buflen)
1791 {
1792 	__be32 status;
1793 	__be32 *p = *pp;
1794 
1795 	status = nfsd4_encode_components(':', location->hosts, &p, buflen);
1796 	if (status)
1797 		return status;
1798 	status = nfsd4_encode_components('/', location->path, &p, buflen);
1799 	if (status)
1800 		return status;
1801 	*pp = p;
1802 	return 0;
1803 }
1804 
1805 /*
1806  * Encode a path in RFC3530 'pathname4' format
1807  */
1808 static __be32 nfsd4_encode_path(const struct path *root,
1809 		const struct path *path, __be32 **pp, int *buflen)
1810 {
1811 	struct path cur = {
1812 		.mnt = path->mnt,
1813 		.dentry = path->dentry,
1814 	};
1815 	__be32 *p = *pp;
1816 	struct dentry **components = NULL;
1817 	unsigned int ncomponents = 0;
1818 	__be32 err = nfserr_jukebox;
1819 
1820 	dprintk("nfsd4_encode_components(");
1821 
1822 	path_get(&cur);
1823 	/* First walk the path up to the nfsd root, and store the
1824 	 * dentries/path components in an array.
1825 	 */
1826 	for (;;) {
1827 		if (cur.dentry == root->dentry && cur.mnt == root->mnt)
1828 			break;
1829 		if (cur.dentry == cur.mnt->mnt_root) {
1830 			if (follow_up(&cur))
1831 				continue;
1832 			goto out_free;
1833 		}
1834 		if ((ncomponents & 15) == 0) {
1835 			struct dentry **new;
1836 			new = krealloc(components,
1837 					sizeof(*new) * (ncomponents + 16),
1838 					GFP_KERNEL);
1839 			if (!new)
1840 				goto out_free;
1841 			components = new;
1842 		}
1843 		components[ncomponents++] = cur.dentry;
1844 		cur.dentry = dget_parent(cur.dentry);
1845 	}
1846 
1847 	*buflen -= 4;
1848 	if (*buflen < 0)
1849 		goto out_free;
1850 	WRITE32(ncomponents);
1851 
1852 	while (ncomponents) {
1853 		struct dentry *dentry = components[ncomponents - 1];
1854 		unsigned int len = dentry->d_name.len;
1855 
1856 		*buflen -= 4 + (XDR_QUADLEN(len) << 2);
1857 		if (*buflen < 0)
1858 			goto out_free;
1859 		WRITE32(len);
1860 		WRITEMEM(dentry->d_name.name, len);
1861 		dprintk("/%s", dentry->d_name.name);
1862 		dput(dentry);
1863 		ncomponents--;
1864 	}
1865 
1866 	*pp = p;
1867 	err = 0;
1868 out_free:
1869 	dprintk(")\n");
1870 	while (ncomponents)
1871 		dput(components[--ncomponents]);
1872 	kfree(components);
1873 	path_put(&cur);
1874 	return err;
1875 }
1876 
1877 static __be32 nfsd4_encode_fsloc_fsroot(struct svc_rqst *rqstp,
1878 		const struct path *path, __be32 **pp, int *buflen)
1879 {
1880 	struct svc_export *exp_ps;
1881 	__be32 res;
1882 
1883 	exp_ps = rqst_find_fsidzero_export(rqstp);
1884 	if (IS_ERR(exp_ps))
1885 		return nfserrno(PTR_ERR(exp_ps));
1886 	res = nfsd4_encode_path(&exp_ps->ex_path, path, pp, buflen);
1887 	exp_put(exp_ps);
1888 	return res;
1889 }
1890 
1891 /*
1892  *  encode a fs_locations structure
1893  */
1894 static __be32 nfsd4_encode_fs_locations(struct svc_rqst *rqstp,
1895 				     struct svc_export *exp,
1896 				     __be32 **pp, int *buflen)
1897 {
1898 	__be32 status;
1899 	int i;
1900 	__be32 *p = *pp;
1901 	struct nfsd4_fs_locations *fslocs = &exp->ex_fslocs;
1902 
1903 	status = nfsd4_encode_fsloc_fsroot(rqstp, &exp->ex_path, &p, buflen);
1904 	if (status)
1905 		return status;
1906 	if ((*buflen -= 4) < 0)
1907 		return nfserr_resource;
1908 	WRITE32(fslocs->locations_count);
1909 	for (i=0; i<fslocs->locations_count; i++) {
1910 		status = nfsd4_encode_fs_location4(&fslocs->locations[i],
1911 						   &p, buflen);
1912 		if (status)
1913 			return status;
1914 	}
1915 	*pp = p;
1916 	return 0;
1917 }
1918 
1919 static u32 nfs4_file_type(umode_t mode)
1920 {
1921 	switch (mode & S_IFMT) {
1922 	case S_IFIFO:	return NF4FIFO;
1923 	case S_IFCHR:	return NF4CHR;
1924 	case S_IFDIR:	return NF4DIR;
1925 	case S_IFBLK:	return NF4BLK;
1926 	case S_IFLNK:	return NF4LNK;
1927 	case S_IFREG:	return NF4REG;
1928 	case S_IFSOCK:	return NF4SOCK;
1929 	default:	return NF4BAD;
1930 	};
1931 }
1932 
1933 static __be32
1934 nfsd4_encode_name(struct svc_rqst *rqstp, int whotype, uid_t id, int group,
1935 			__be32 **p, int *buflen)
1936 {
1937 	int status;
1938 
1939 	if (*buflen < (XDR_QUADLEN(IDMAP_NAMESZ) << 2) + 4)
1940 		return nfserr_resource;
1941 	if (whotype != NFS4_ACL_WHO_NAMED)
1942 		status = nfs4_acl_write_who(whotype, (u8 *)(*p + 1));
1943 	else if (group)
1944 		status = nfsd_map_gid_to_name(rqstp, id, (u8 *)(*p + 1));
1945 	else
1946 		status = nfsd_map_uid_to_name(rqstp, id, (u8 *)(*p + 1));
1947 	if (status < 0)
1948 		return nfserrno(status);
1949 	*p = xdr_encode_opaque(*p, NULL, status);
1950 	*buflen -= (XDR_QUADLEN(status) << 2) + 4;
1951 	BUG_ON(*buflen < 0);
1952 	return 0;
1953 }
1954 
1955 static inline __be32
1956 nfsd4_encode_user(struct svc_rqst *rqstp, uid_t uid, __be32 **p, int *buflen)
1957 {
1958 	return nfsd4_encode_name(rqstp, NFS4_ACL_WHO_NAMED, uid, 0, p, buflen);
1959 }
1960 
1961 static inline __be32
1962 nfsd4_encode_group(struct svc_rqst *rqstp, uid_t gid, __be32 **p, int *buflen)
1963 {
1964 	return nfsd4_encode_name(rqstp, NFS4_ACL_WHO_NAMED, gid, 1, p, buflen);
1965 }
1966 
1967 static inline __be32
1968 nfsd4_encode_aclname(struct svc_rqst *rqstp, int whotype, uid_t id, int group,
1969 		__be32 **p, int *buflen)
1970 {
1971 	return nfsd4_encode_name(rqstp, whotype, id, group, p, buflen);
1972 }
1973 
1974 #define WORD0_ABSENT_FS_ATTRS (FATTR4_WORD0_FS_LOCATIONS | FATTR4_WORD0_FSID | \
1975 			      FATTR4_WORD0_RDATTR_ERROR)
1976 #define WORD1_ABSENT_FS_ATTRS FATTR4_WORD1_MOUNTED_ON_FILEID
1977 
1978 static __be32 fattr_handle_absent_fs(u32 *bmval0, u32 *bmval1, u32 *rdattr_err)
1979 {
1980 	/* As per referral draft:  */
1981 	if (*bmval0 & ~WORD0_ABSENT_FS_ATTRS ||
1982 	    *bmval1 & ~WORD1_ABSENT_FS_ATTRS) {
1983 		if (*bmval0 & FATTR4_WORD0_RDATTR_ERROR ||
1984 	            *bmval0 & FATTR4_WORD0_FS_LOCATIONS)
1985 			*rdattr_err = NFSERR_MOVED;
1986 		else
1987 			return nfserr_moved;
1988 	}
1989 	*bmval0 &= WORD0_ABSENT_FS_ATTRS;
1990 	*bmval1 &= WORD1_ABSENT_FS_ATTRS;
1991 	return 0;
1992 }
1993 
1994 /*
1995  * Note: @fhp can be NULL; in this case, we might have to compose the filehandle
1996  * ourselves.
1997  *
1998  * @countp is the buffer size in _words_; upon successful return this becomes
1999  * replaced with the number of words written.
2000  */
2001 __be32
2002 nfsd4_encode_fattr(struct svc_fh *fhp, struct svc_export *exp,
2003 		struct dentry *dentry, __be32 *buffer, int *countp, u32 *bmval,
2004 		struct svc_rqst *rqstp, int ignore_crossmnt)
2005 {
2006 	u32 bmval0 = bmval[0];
2007 	u32 bmval1 = bmval[1];
2008 	u32 bmval2 = bmval[2];
2009 	struct kstat stat;
2010 	struct svc_fh tempfh;
2011 	struct kstatfs statfs;
2012 	int buflen = *countp << 2;
2013 	__be32 *attrlenp;
2014 	u32 dummy;
2015 	u64 dummy64;
2016 	u32 rdattr_err = 0;
2017 	__be32 *p = buffer;
2018 	__be32 status;
2019 	int err;
2020 	int aclsupport = 0;
2021 	struct nfs4_acl *acl = NULL;
2022 	struct nfsd4_compoundres *resp = rqstp->rq_resp;
2023 	u32 minorversion = resp->cstate.minorversion;
2024 	struct path path = {
2025 		.mnt	= exp->ex_path.mnt,
2026 		.dentry	= dentry,
2027 	};
2028 
2029 	BUG_ON(bmval1 & NFSD_WRITEONLY_ATTRS_WORD1);
2030 	BUG_ON(bmval0 & ~nfsd_suppattrs0(minorversion));
2031 	BUG_ON(bmval1 & ~nfsd_suppattrs1(minorversion));
2032 	BUG_ON(bmval2 & ~nfsd_suppattrs2(minorversion));
2033 
2034 	if (exp->ex_fslocs.migrated) {
2035 		BUG_ON(bmval[2]);
2036 		status = fattr_handle_absent_fs(&bmval0, &bmval1, &rdattr_err);
2037 		if (status)
2038 			goto out;
2039 	}
2040 
2041 	err = vfs_getattr(exp->ex_path.mnt, dentry, &stat);
2042 	if (err)
2043 		goto out_nfserr;
2044 	if ((bmval0 & (FATTR4_WORD0_FILES_FREE | FATTR4_WORD0_FILES_TOTAL |
2045 			FATTR4_WORD0_MAXNAME)) ||
2046 	    (bmval1 & (FATTR4_WORD1_SPACE_AVAIL | FATTR4_WORD1_SPACE_FREE |
2047 		       FATTR4_WORD1_SPACE_TOTAL))) {
2048 		err = vfs_statfs(&path, &statfs);
2049 		if (err)
2050 			goto out_nfserr;
2051 	}
2052 	if ((bmval0 & (FATTR4_WORD0_FILEHANDLE | FATTR4_WORD0_FSID)) && !fhp) {
2053 		fh_init(&tempfh, NFS4_FHSIZE);
2054 		status = fh_compose(&tempfh, exp, dentry, NULL);
2055 		if (status)
2056 			goto out;
2057 		fhp = &tempfh;
2058 	}
2059 	if (bmval0 & (FATTR4_WORD0_ACL | FATTR4_WORD0_ACLSUPPORT
2060 			| FATTR4_WORD0_SUPPORTED_ATTRS)) {
2061 		err = nfsd4_get_nfs4_acl(rqstp, dentry, &acl);
2062 		aclsupport = (err == 0);
2063 		if (bmval0 & FATTR4_WORD0_ACL) {
2064 			if (err == -EOPNOTSUPP)
2065 				bmval0 &= ~FATTR4_WORD0_ACL;
2066 			else if (err == -EINVAL) {
2067 				status = nfserr_attrnotsupp;
2068 				goto out;
2069 			} else if (err != 0)
2070 				goto out_nfserr;
2071 		}
2072 	}
2073 
2074 	if (bmval2) {
2075 		if ((buflen -= 16) < 0)
2076 			goto out_resource;
2077 		WRITE32(3);
2078 		WRITE32(bmval0);
2079 		WRITE32(bmval1);
2080 		WRITE32(bmval2);
2081 	} else if (bmval1) {
2082 		if ((buflen -= 12) < 0)
2083 			goto out_resource;
2084 		WRITE32(2);
2085 		WRITE32(bmval0);
2086 		WRITE32(bmval1);
2087 	} else {
2088 		if ((buflen -= 8) < 0)
2089 			goto out_resource;
2090 		WRITE32(1);
2091 		WRITE32(bmval0);
2092 	}
2093 	attrlenp = p++;                /* to be backfilled later */
2094 
2095 	if (bmval0 & FATTR4_WORD0_SUPPORTED_ATTRS) {
2096 		u32 word0 = nfsd_suppattrs0(minorversion);
2097 		u32 word1 = nfsd_suppattrs1(minorversion);
2098 		u32 word2 = nfsd_suppattrs2(minorversion);
2099 
2100 		if (!aclsupport)
2101 			word0 &= ~FATTR4_WORD0_ACL;
2102 		if (!word2) {
2103 			if ((buflen -= 12) < 0)
2104 				goto out_resource;
2105 			WRITE32(2);
2106 			WRITE32(word0);
2107 			WRITE32(word1);
2108 		} else {
2109 			if ((buflen -= 16) < 0)
2110 				goto out_resource;
2111 			WRITE32(3);
2112 			WRITE32(word0);
2113 			WRITE32(word1);
2114 			WRITE32(word2);
2115 		}
2116 	}
2117 	if (bmval0 & FATTR4_WORD0_TYPE) {
2118 		if ((buflen -= 4) < 0)
2119 			goto out_resource;
2120 		dummy = nfs4_file_type(stat.mode);
2121 		if (dummy == NF4BAD)
2122 			goto out_serverfault;
2123 		WRITE32(dummy);
2124 	}
2125 	if (bmval0 & FATTR4_WORD0_FH_EXPIRE_TYPE) {
2126 		if ((buflen -= 4) < 0)
2127 			goto out_resource;
2128 		if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
2129 			WRITE32(NFS4_FH_PERSISTENT);
2130 		else
2131 			WRITE32(NFS4_FH_PERSISTENT|NFS4_FH_VOL_RENAME);
2132 	}
2133 	if (bmval0 & FATTR4_WORD0_CHANGE) {
2134 		if ((buflen -= 8) < 0)
2135 			goto out_resource;
2136 		write_change(&p, &stat, dentry->d_inode);
2137 	}
2138 	if (bmval0 & FATTR4_WORD0_SIZE) {
2139 		if ((buflen -= 8) < 0)
2140 			goto out_resource;
2141 		WRITE64(stat.size);
2142 	}
2143 	if (bmval0 & FATTR4_WORD0_LINK_SUPPORT) {
2144 		if ((buflen -= 4) < 0)
2145 			goto out_resource;
2146 		WRITE32(1);
2147 	}
2148 	if (bmval0 & FATTR4_WORD0_SYMLINK_SUPPORT) {
2149 		if ((buflen -= 4) < 0)
2150 			goto out_resource;
2151 		WRITE32(1);
2152 	}
2153 	if (bmval0 & FATTR4_WORD0_NAMED_ATTR) {
2154 		if ((buflen -= 4) < 0)
2155 			goto out_resource;
2156 		WRITE32(0);
2157 	}
2158 	if (bmval0 & FATTR4_WORD0_FSID) {
2159 		if ((buflen -= 16) < 0)
2160 			goto out_resource;
2161 		if (exp->ex_fslocs.migrated) {
2162 			WRITE64(NFS4_REFERRAL_FSID_MAJOR);
2163 			WRITE64(NFS4_REFERRAL_FSID_MINOR);
2164 		} else switch(fsid_source(fhp)) {
2165 		case FSIDSOURCE_FSID:
2166 			WRITE64((u64)exp->ex_fsid);
2167 			WRITE64((u64)0);
2168 			break;
2169 		case FSIDSOURCE_DEV:
2170 			WRITE32(0);
2171 			WRITE32(MAJOR(stat.dev));
2172 			WRITE32(0);
2173 			WRITE32(MINOR(stat.dev));
2174 			break;
2175 		case FSIDSOURCE_UUID:
2176 			WRITEMEM(exp->ex_uuid, 16);
2177 			break;
2178 		}
2179 	}
2180 	if (bmval0 & FATTR4_WORD0_UNIQUE_HANDLES) {
2181 		if ((buflen -= 4) < 0)
2182 			goto out_resource;
2183 		WRITE32(0);
2184 	}
2185 	if (bmval0 & FATTR4_WORD0_LEASE_TIME) {
2186 		if ((buflen -= 4) < 0)
2187 			goto out_resource;
2188 		WRITE32(nfsd4_lease);
2189 	}
2190 	if (bmval0 & FATTR4_WORD0_RDATTR_ERROR) {
2191 		if ((buflen -= 4) < 0)
2192 			goto out_resource;
2193 		WRITE32(rdattr_err);
2194 	}
2195 	if (bmval0 & FATTR4_WORD0_ACL) {
2196 		struct nfs4_ace *ace;
2197 
2198 		if (acl == NULL) {
2199 			if ((buflen -= 4) < 0)
2200 				goto out_resource;
2201 
2202 			WRITE32(0);
2203 			goto out_acl;
2204 		}
2205 		if ((buflen -= 4) < 0)
2206 			goto out_resource;
2207 		WRITE32(acl->naces);
2208 
2209 		for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) {
2210 			if ((buflen -= 4*3) < 0)
2211 				goto out_resource;
2212 			WRITE32(ace->type);
2213 			WRITE32(ace->flag);
2214 			WRITE32(ace->access_mask & NFS4_ACE_MASK_ALL);
2215 			status = nfsd4_encode_aclname(rqstp, ace->whotype,
2216 				ace->who, ace->flag & NFS4_ACE_IDENTIFIER_GROUP,
2217 				&p, &buflen);
2218 			if (status == nfserr_resource)
2219 				goto out_resource;
2220 			if (status)
2221 				goto out;
2222 		}
2223 	}
2224 out_acl:
2225 	if (bmval0 & FATTR4_WORD0_ACLSUPPORT) {
2226 		if ((buflen -= 4) < 0)
2227 			goto out_resource;
2228 		WRITE32(aclsupport ?
2229 			ACL4_SUPPORT_ALLOW_ACL|ACL4_SUPPORT_DENY_ACL : 0);
2230 	}
2231 	if (bmval0 & FATTR4_WORD0_CANSETTIME) {
2232 		if ((buflen -= 4) < 0)
2233 			goto out_resource;
2234 		WRITE32(1);
2235 	}
2236 	if (bmval0 & FATTR4_WORD0_CASE_INSENSITIVE) {
2237 		if ((buflen -= 4) < 0)
2238 			goto out_resource;
2239 		WRITE32(1);
2240 	}
2241 	if (bmval0 & FATTR4_WORD0_CASE_PRESERVING) {
2242 		if ((buflen -= 4) < 0)
2243 			goto out_resource;
2244 		WRITE32(1);
2245 	}
2246 	if (bmval0 & FATTR4_WORD0_CHOWN_RESTRICTED) {
2247 		if ((buflen -= 4) < 0)
2248 			goto out_resource;
2249 		WRITE32(1);
2250 	}
2251 	if (bmval0 & FATTR4_WORD0_FILEHANDLE) {
2252 		buflen -= (XDR_QUADLEN(fhp->fh_handle.fh_size) << 2) + 4;
2253 		if (buflen < 0)
2254 			goto out_resource;
2255 		WRITE32(fhp->fh_handle.fh_size);
2256 		WRITEMEM(&fhp->fh_handle.fh_base, fhp->fh_handle.fh_size);
2257 	}
2258 	if (bmval0 & FATTR4_WORD0_FILEID) {
2259 		if ((buflen -= 8) < 0)
2260 			goto out_resource;
2261 		WRITE64(stat.ino);
2262 	}
2263 	if (bmval0 & FATTR4_WORD0_FILES_AVAIL) {
2264 		if ((buflen -= 8) < 0)
2265 			goto out_resource;
2266 		WRITE64((u64) statfs.f_ffree);
2267 	}
2268 	if (bmval0 & FATTR4_WORD0_FILES_FREE) {
2269 		if ((buflen -= 8) < 0)
2270 			goto out_resource;
2271 		WRITE64((u64) statfs.f_ffree);
2272 	}
2273 	if (bmval0 & FATTR4_WORD0_FILES_TOTAL) {
2274 		if ((buflen -= 8) < 0)
2275 			goto out_resource;
2276 		WRITE64((u64) statfs.f_files);
2277 	}
2278 	if (bmval0 & FATTR4_WORD0_FS_LOCATIONS) {
2279 		status = nfsd4_encode_fs_locations(rqstp, exp, &p, &buflen);
2280 		if (status == nfserr_resource)
2281 			goto out_resource;
2282 		if (status)
2283 			goto out;
2284 	}
2285 	if (bmval0 & FATTR4_WORD0_HOMOGENEOUS) {
2286 		if ((buflen -= 4) < 0)
2287 			goto out_resource;
2288 		WRITE32(1);
2289 	}
2290 	if (bmval0 & FATTR4_WORD0_MAXFILESIZE) {
2291 		if ((buflen -= 8) < 0)
2292 			goto out_resource;
2293 		WRITE64(~(u64)0);
2294 	}
2295 	if (bmval0 & FATTR4_WORD0_MAXLINK) {
2296 		if ((buflen -= 4) < 0)
2297 			goto out_resource;
2298 		WRITE32(255);
2299 	}
2300 	if (bmval0 & FATTR4_WORD0_MAXNAME) {
2301 		if ((buflen -= 4) < 0)
2302 			goto out_resource;
2303 		WRITE32(statfs.f_namelen);
2304 	}
2305 	if (bmval0 & FATTR4_WORD0_MAXREAD) {
2306 		if ((buflen -= 8) < 0)
2307 			goto out_resource;
2308 		WRITE64((u64) svc_max_payload(rqstp));
2309 	}
2310 	if (bmval0 & FATTR4_WORD0_MAXWRITE) {
2311 		if ((buflen -= 8) < 0)
2312 			goto out_resource;
2313 		WRITE64((u64) svc_max_payload(rqstp));
2314 	}
2315 	if (bmval1 & FATTR4_WORD1_MODE) {
2316 		if ((buflen -= 4) < 0)
2317 			goto out_resource;
2318 		WRITE32(stat.mode & S_IALLUGO);
2319 	}
2320 	if (bmval1 & FATTR4_WORD1_NO_TRUNC) {
2321 		if ((buflen -= 4) < 0)
2322 			goto out_resource;
2323 		WRITE32(1);
2324 	}
2325 	if (bmval1 & FATTR4_WORD1_NUMLINKS) {
2326 		if ((buflen -= 4) < 0)
2327 			goto out_resource;
2328 		WRITE32(stat.nlink);
2329 	}
2330 	if (bmval1 & FATTR4_WORD1_OWNER) {
2331 		status = nfsd4_encode_user(rqstp, stat.uid, &p, &buflen);
2332 		if (status == nfserr_resource)
2333 			goto out_resource;
2334 		if (status)
2335 			goto out;
2336 	}
2337 	if (bmval1 & FATTR4_WORD1_OWNER_GROUP) {
2338 		status = nfsd4_encode_group(rqstp, stat.gid, &p, &buflen);
2339 		if (status == nfserr_resource)
2340 			goto out_resource;
2341 		if (status)
2342 			goto out;
2343 	}
2344 	if (bmval1 & FATTR4_WORD1_RAWDEV) {
2345 		if ((buflen -= 8) < 0)
2346 			goto out_resource;
2347 		WRITE32((u32) MAJOR(stat.rdev));
2348 		WRITE32((u32) MINOR(stat.rdev));
2349 	}
2350 	if (bmval1 & FATTR4_WORD1_SPACE_AVAIL) {
2351 		if ((buflen -= 8) < 0)
2352 			goto out_resource;
2353 		dummy64 = (u64)statfs.f_bavail * (u64)statfs.f_bsize;
2354 		WRITE64(dummy64);
2355 	}
2356 	if (bmval1 & FATTR4_WORD1_SPACE_FREE) {
2357 		if ((buflen -= 8) < 0)
2358 			goto out_resource;
2359 		dummy64 = (u64)statfs.f_bfree * (u64)statfs.f_bsize;
2360 		WRITE64(dummy64);
2361 	}
2362 	if (bmval1 & FATTR4_WORD1_SPACE_TOTAL) {
2363 		if ((buflen -= 8) < 0)
2364 			goto out_resource;
2365 		dummy64 = (u64)statfs.f_blocks * (u64)statfs.f_bsize;
2366 		WRITE64(dummy64);
2367 	}
2368 	if (bmval1 & FATTR4_WORD1_SPACE_USED) {
2369 		if ((buflen -= 8) < 0)
2370 			goto out_resource;
2371 		dummy64 = (u64)stat.blocks << 9;
2372 		WRITE64(dummy64);
2373 	}
2374 	if (bmval1 & FATTR4_WORD1_TIME_ACCESS) {
2375 		if ((buflen -= 12) < 0)
2376 			goto out_resource;
2377 		WRITE32(0);
2378 		WRITE32(stat.atime.tv_sec);
2379 		WRITE32(stat.atime.tv_nsec);
2380 	}
2381 	if (bmval1 & FATTR4_WORD1_TIME_DELTA) {
2382 		if ((buflen -= 12) < 0)
2383 			goto out_resource;
2384 		WRITE32(0);
2385 		WRITE32(1);
2386 		WRITE32(0);
2387 	}
2388 	if (bmval1 & FATTR4_WORD1_TIME_METADATA) {
2389 		if ((buflen -= 12) < 0)
2390 			goto out_resource;
2391 		WRITE32(0);
2392 		WRITE32(stat.ctime.tv_sec);
2393 		WRITE32(stat.ctime.tv_nsec);
2394 	}
2395 	if (bmval1 & FATTR4_WORD1_TIME_MODIFY) {
2396 		if ((buflen -= 12) < 0)
2397 			goto out_resource;
2398 		WRITE32(0);
2399 		WRITE32(stat.mtime.tv_sec);
2400 		WRITE32(stat.mtime.tv_nsec);
2401 	}
2402 	if (bmval1 & FATTR4_WORD1_MOUNTED_ON_FILEID) {
2403 		if ((buflen -= 8) < 0)
2404                 	goto out_resource;
2405 		/*
2406 		 * Get parent's attributes if not ignoring crossmount
2407 		 * and this is the root of a cross-mounted filesystem.
2408 		 */
2409 		if (ignore_crossmnt == 0 &&
2410 		    dentry == exp->ex_path.mnt->mnt_root) {
2411 			struct path path = exp->ex_path;
2412 			path_get(&path);
2413 			while (follow_up(&path)) {
2414 				if (path.dentry != path.mnt->mnt_root)
2415 					break;
2416 			}
2417 			err = vfs_getattr(path.mnt, path.dentry, &stat);
2418 			path_put(&path);
2419 			if (err)
2420 				goto out_nfserr;
2421 		}
2422 		WRITE64(stat.ino);
2423 	}
2424 	if (bmval2 & FATTR4_WORD2_SUPPATTR_EXCLCREAT) {
2425 		WRITE32(3);
2426 		WRITE32(NFSD_SUPPATTR_EXCLCREAT_WORD0);
2427 		WRITE32(NFSD_SUPPATTR_EXCLCREAT_WORD1);
2428 		WRITE32(NFSD_SUPPATTR_EXCLCREAT_WORD2);
2429 	}
2430 
2431 	*attrlenp = htonl((char *)p - (char *)attrlenp - 4);
2432 	*countp = p - buffer;
2433 	status = nfs_ok;
2434 
2435 out:
2436 	kfree(acl);
2437 	if (fhp == &tempfh)
2438 		fh_put(&tempfh);
2439 	return status;
2440 out_nfserr:
2441 	status = nfserrno(err);
2442 	goto out;
2443 out_resource:
2444 	*countp = 0;
2445 	status = nfserr_resource;
2446 	goto out;
2447 out_serverfault:
2448 	status = nfserr_serverfault;
2449 	goto out;
2450 }
2451 
2452 static inline int attributes_need_mount(u32 *bmval)
2453 {
2454 	if (bmval[0] & ~(FATTR4_WORD0_RDATTR_ERROR | FATTR4_WORD0_LEASE_TIME))
2455 		return 1;
2456 	if (bmval[1] & ~FATTR4_WORD1_MOUNTED_ON_FILEID)
2457 		return 1;
2458 	return 0;
2459 }
2460 
2461 static __be32
2462 nfsd4_encode_dirent_fattr(struct nfsd4_readdir *cd,
2463 		const char *name, int namlen, __be32 *p, int *buflen)
2464 {
2465 	struct svc_export *exp = cd->rd_fhp->fh_export;
2466 	struct dentry *dentry;
2467 	__be32 nfserr;
2468 	int ignore_crossmnt = 0;
2469 
2470 	dentry = lookup_one_len(name, cd->rd_fhp->fh_dentry, namlen);
2471 	if (IS_ERR(dentry))
2472 		return nfserrno(PTR_ERR(dentry));
2473 	if (!dentry->d_inode) {
2474 		/*
2475 		 * nfsd_buffered_readdir drops the i_mutex between
2476 		 * readdir and calling this callback, leaving a window
2477 		 * where this directory entry could have gone away.
2478 		 */
2479 		dput(dentry);
2480 		return nfserr_noent;
2481 	}
2482 
2483 	exp_get(exp);
2484 	/*
2485 	 * In the case of a mountpoint, the client may be asking for
2486 	 * attributes that are only properties of the underlying filesystem
2487 	 * as opposed to the cross-mounted file system. In such a case,
2488 	 * we will not follow the cross mount and will fill the attribtutes
2489 	 * directly from the mountpoint dentry.
2490 	 */
2491 	if (nfsd_mountpoint(dentry, exp)) {
2492 		int err;
2493 
2494 		if (!(exp->ex_flags & NFSEXP_V4ROOT)
2495 				&& !attributes_need_mount(cd->rd_bmval)) {
2496 			ignore_crossmnt = 1;
2497 			goto out_encode;
2498 		}
2499 		/*
2500 		 * Why the heck aren't we just using nfsd_lookup??
2501 		 * Different "."/".." handling?  Something else?
2502 		 * At least, add a comment here to explain....
2503 		 */
2504 		err = nfsd_cross_mnt(cd->rd_rqstp, &dentry, &exp);
2505 		if (err) {
2506 			nfserr = nfserrno(err);
2507 			goto out_put;
2508 		}
2509 		nfserr = check_nfsd_access(exp, cd->rd_rqstp);
2510 		if (nfserr)
2511 			goto out_put;
2512 
2513 	}
2514 out_encode:
2515 	nfserr = nfsd4_encode_fattr(NULL, exp, dentry, p, buflen, cd->rd_bmval,
2516 					cd->rd_rqstp, ignore_crossmnt);
2517 out_put:
2518 	dput(dentry);
2519 	exp_put(exp);
2520 	return nfserr;
2521 }
2522 
2523 static __be32 *
2524 nfsd4_encode_rdattr_error(__be32 *p, int buflen, __be32 nfserr)
2525 {
2526 	__be32 *attrlenp;
2527 
2528 	if (buflen < 6)
2529 		return NULL;
2530 	*p++ = htonl(2);
2531 	*p++ = htonl(FATTR4_WORD0_RDATTR_ERROR); /* bmval0 */
2532 	*p++ = htonl(0);			 /* bmval1 */
2533 
2534 	attrlenp = p++;
2535 	*p++ = nfserr;       /* no htonl */
2536 	*attrlenp = htonl((char *)p - (char *)attrlenp - 4);
2537 	return p;
2538 }
2539 
2540 static int
2541 nfsd4_encode_dirent(void *ccdv, const char *name, int namlen,
2542 		    loff_t offset, u64 ino, unsigned int d_type)
2543 {
2544 	struct readdir_cd *ccd = ccdv;
2545 	struct nfsd4_readdir *cd = container_of(ccd, struct nfsd4_readdir, common);
2546 	int buflen;
2547 	__be32 *p = cd->buffer;
2548 	__be32 *cookiep;
2549 	__be32 nfserr = nfserr_toosmall;
2550 
2551 	/* In nfsv4, "." and ".." never make it onto the wire.. */
2552 	if (name && isdotent(name, namlen)) {
2553 		cd->common.err = nfs_ok;
2554 		return 0;
2555 	}
2556 
2557 	if (cd->offset)
2558 		xdr_encode_hyper(cd->offset, (u64) offset);
2559 
2560 	buflen = cd->buflen - 4 - XDR_QUADLEN(namlen);
2561 	if (buflen < 0)
2562 		goto fail;
2563 
2564 	*p++ = xdr_one;                             /* mark entry present */
2565 	cookiep = p;
2566 	p = xdr_encode_hyper(p, NFS_OFFSET_MAX);    /* offset of next entry */
2567 	p = xdr_encode_array(p, name, namlen);      /* name length & name */
2568 
2569 	nfserr = nfsd4_encode_dirent_fattr(cd, name, namlen, p, &buflen);
2570 	switch (nfserr) {
2571 	case nfs_ok:
2572 		p += buflen;
2573 		break;
2574 	case nfserr_resource:
2575 		nfserr = nfserr_toosmall;
2576 		goto fail;
2577 	case nfserr_noent:
2578 		goto skip_entry;
2579 	default:
2580 		/*
2581 		 * If the client requested the RDATTR_ERROR attribute,
2582 		 * we stuff the error code into this attribute
2583 		 * and continue.  If this attribute was not requested,
2584 		 * then in accordance with the spec, we fail the
2585 		 * entire READDIR operation(!)
2586 		 */
2587 		if (!(cd->rd_bmval[0] & FATTR4_WORD0_RDATTR_ERROR))
2588 			goto fail;
2589 		p = nfsd4_encode_rdattr_error(p, buflen, nfserr);
2590 		if (p == NULL) {
2591 			nfserr = nfserr_toosmall;
2592 			goto fail;
2593 		}
2594 	}
2595 	cd->buflen -= (p - cd->buffer);
2596 	cd->buffer = p;
2597 	cd->offset = cookiep;
2598 skip_entry:
2599 	cd->common.err = nfs_ok;
2600 	return 0;
2601 fail:
2602 	cd->common.err = nfserr;
2603 	return -EINVAL;
2604 }
2605 
2606 static void
2607 nfsd4_encode_stateid(struct nfsd4_compoundres *resp, stateid_t *sid)
2608 {
2609 	__be32 *p;
2610 
2611 	RESERVE_SPACE(sizeof(stateid_t));
2612 	WRITE32(sid->si_generation);
2613 	WRITEMEM(&sid->si_opaque, sizeof(stateid_opaque_t));
2614 	ADJUST_ARGS();
2615 }
2616 
2617 static __be32
2618 nfsd4_encode_access(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_access *access)
2619 {
2620 	__be32 *p;
2621 
2622 	if (!nfserr) {
2623 		RESERVE_SPACE(8);
2624 		WRITE32(access->ac_supported);
2625 		WRITE32(access->ac_resp_access);
2626 		ADJUST_ARGS();
2627 	}
2628 	return nfserr;
2629 }
2630 
2631 static __be32 nfsd4_encode_bind_conn_to_session(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_bind_conn_to_session *bcts)
2632 {
2633 	__be32 *p;
2634 
2635 	if (!nfserr) {
2636 		RESERVE_SPACE(NFS4_MAX_SESSIONID_LEN + 8);
2637 		WRITEMEM(bcts->sessionid.data, NFS4_MAX_SESSIONID_LEN);
2638 		WRITE32(bcts->dir);
2639 		/* XXX: ? */
2640 		WRITE32(0);
2641 		ADJUST_ARGS();
2642 	}
2643 	return nfserr;
2644 }
2645 
2646 static __be32
2647 nfsd4_encode_close(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_close *close)
2648 {
2649 	ENCODE_SEQID_OP_HEAD;
2650 
2651 	if (!nfserr)
2652 		nfsd4_encode_stateid(resp, &close->cl_stateid);
2653 
2654 	encode_seqid_op_tail(resp, save, nfserr);
2655 	return nfserr;
2656 }
2657 
2658 
2659 static __be32
2660 nfsd4_encode_commit(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_commit *commit)
2661 {
2662 	__be32 *p;
2663 
2664 	if (!nfserr) {
2665 		RESERVE_SPACE(8);
2666 		WRITEMEM(commit->co_verf.data, 8);
2667 		ADJUST_ARGS();
2668 	}
2669 	return nfserr;
2670 }
2671 
2672 static __be32
2673 nfsd4_encode_create(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_create *create)
2674 {
2675 	__be32 *p;
2676 
2677 	if (!nfserr) {
2678 		RESERVE_SPACE(32);
2679 		write_cinfo(&p, &create->cr_cinfo);
2680 		WRITE32(2);
2681 		WRITE32(create->cr_bmval[0]);
2682 		WRITE32(create->cr_bmval[1]);
2683 		ADJUST_ARGS();
2684 	}
2685 	return nfserr;
2686 }
2687 
2688 static __be32
2689 nfsd4_encode_getattr(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_getattr *getattr)
2690 {
2691 	struct svc_fh *fhp = getattr->ga_fhp;
2692 	int buflen;
2693 
2694 	if (nfserr)
2695 		return nfserr;
2696 
2697 	buflen = resp->end - resp->p - (COMPOUND_ERR_SLACK_SPACE >> 2);
2698 	nfserr = nfsd4_encode_fattr(fhp, fhp->fh_export, fhp->fh_dentry,
2699 				    resp->p, &buflen, getattr->ga_bmval,
2700 				    resp->rqstp, 0);
2701 	if (!nfserr)
2702 		resp->p += buflen;
2703 	return nfserr;
2704 }
2705 
2706 static __be32
2707 nfsd4_encode_getfh(struct nfsd4_compoundres *resp, __be32 nfserr, struct svc_fh **fhpp)
2708 {
2709 	struct svc_fh *fhp = *fhpp;
2710 	unsigned int len;
2711 	__be32 *p;
2712 
2713 	if (!nfserr) {
2714 		len = fhp->fh_handle.fh_size;
2715 		RESERVE_SPACE(len + 4);
2716 		WRITE32(len);
2717 		WRITEMEM(&fhp->fh_handle.fh_base, len);
2718 		ADJUST_ARGS();
2719 	}
2720 	return nfserr;
2721 }
2722 
2723 /*
2724 * Including all fields other than the name, a LOCK4denied structure requires
2725 *   8(clientid) + 4(namelen) + 8(offset) + 8(length) + 4(type) = 32 bytes.
2726 */
2727 static void
2728 nfsd4_encode_lock_denied(struct nfsd4_compoundres *resp, struct nfsd4_lock_denied *ld)
2729 {
2730 	struct xdr_netobj *conf = &ld->ld_owner;
2731 	__be32 *p;
2732 
2733 	RESERVE_SPACE(32 + XDR_LEN(conf->len));
2734 	WRITE64(ld->ld_start);
2735 	WRITE64(ld->ld_length);
2736 	WRITE32(ld->ld_type);
2737 	if (conf->len) {
2738 		WRITEMEM(&ld->ld_clientid, 8);
2739 		WRITE32(conf->len);
2740 		WRITEMEM(conf->data, conf->len);
2741 		kfree(conf->data);
2742 	}  else {  /* non - nfsv4 lock in conflict, no clientid nor owner */
2743 		WRITE64((u64)0); /* clientid */
2744 		WRITE32(0); /* length of owner name */
2745 	}
2746 	ADJUST_ARGS();
2747 }
2748 
2749 static __be32
2750 nfsd4_encode_lock(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_lock *lock)
2751 {
2752 	ENCODE_SEQID_OP_HEAD;
2753 
2754 	if (!nfserr)
2755 		nfsd4_encode_stateid(resp, &lock->lk_resp_stateid);
2756 	else if (nfserr == nfserr_denied)
2757 		nfsd4_encode_lock_denied(resp, &lock->lk_denied);
2758 
2759 	encode_seqid_op_tail(resp, save, nfserr);
2760 	return nfserr;
2761 }
2762 
2763 static __be32
2764 nfsd4_encode_lockt(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_lockt *lockt)
2765 {
2766 	if (nfserr == nfserr_denied)
2767 		nfsd4_encode_lock_denied(resp, &lockt->lt_denied);
2768 	return nfserr;
2769 }
2770 
2771 static __be32
2772 nfsd4_encode_locku(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_locku *locku)
2773 {
2774 	ENCODE_SEQID_OP_HEAD;
2775 
2776 	if (!nfserr)
2777 		nfsd4_encode_stateid(resp, &locku->lu_stateid);
2778 
2779 	encode_seqid_op_tail(resp, save, nfserr);
2780 	return nfserr;
2781 }
2782 
2783 
2784 static __be32
2785 nfsd4_encode_link(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_link *link)
2786 {
2787 	__be32 *p;
2788 
2789 	if (!nfserr) {
2790 		RESERVE_SPACE(20);
2791 		write_cinfo(&p, &link->li_cinfo);
2792 		ADJUST_ARGS();
2793 	}
2794 	return nfserr;
2795 }
2796 
2797 
2798 static __be32
2799 nfsd4_encode_open(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_open *open)
2800 {
2801 	__be32 *p;
2802 	ENCODE_SEQID_OP_HEAD;
2803 
2804 	if (nfserr)
2805 		goto out;
2806 
2807 	nfsd4_encode_stateid(resp, &open->op_stateid);
2808 	RESERVE_SPACE(40);
2809 	write_cinfo(&p, &open->op_cinfo);
2810 	WRITE32(open->op_rflags);
2811 	WRITE32(2);
2812 	WRITE32(open->op_bmval[0]);
2813 	WRITE32(open->op_bmval[1]);
2814 	WRITE32(open->op_delegate_type);
2815 	ADJUST_ARGS();
2816 
2817 	switch (open->op_delegate_type) {
2818 	case NFS4_OPEN_DELEGATE_NONE:
2819 		break;
2820 	case NFS4_OPEN_DELEGATE_READ:
2821 		nfsd4_encode_stateid(resp, &open->op_delegate_stateid);
2822 		RESERVE_SPACE(20);
2823 		WRITE32(open->op_recall);
2824 
2825 		/*
2826 		 * TODO: ACE's in delegations
2827 		 */
2828 		WRITE32(NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE);
2829 		WRITE32(0);
2830 		WRITE32(0);
2831 		WRITE32(0);   /* XXX: is NULL principal ok? */
2832 		ADJUST_ARGS();
2833 		break;
2834 	case NFS4_OPEN_DELEGATE_WRITE:
2835 		nfsd4_encode_stateid(resp, &open->op_delegate_stateid);
2836 		RESERVE_SPACE(32);
2837 		WRITE32(0);
2838 
2839 		/*
2840 		 * TODO: space_limit's in delegations
2841 		 */
2842 		WRITE32(NFS4_LIMIT_SIZE);
2843 		WRITE32(~(u32)0);
2844 		WRITE32(~(u32)0);
2845 
2846 		/*
2847 		 * TODO: ACE's in delegations
2848 		 */
2849 		WRITE32(NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE);
2850 		WRITE32(0);
2851 		WRITE32(0);
2852 		WRITE32(0);   /* XXX: is NULL principal ok? */
2853 		ADJUST_ARGS();
2854 		break;
2855 	default:
2856 		BUG();
2857 	}
2858 	/* XXX save filehandle here */
2859 out:
2860 	encode_seqid_op_tail(resp, save, nfserr);
2861 	return nfserr;
2862 }
2863 
2864 static __be32
2865 nfsd4_encode_open_confirm(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_open_confirm *oc)
2866 {
2867 	ENCODE_SEQID_OP_HEAD;
2868 
2869 	if (!nfserr)
2870 		nfsd4_encode_stateid(resp, &oc->oc_resp_stateid);
2871 
2872 	encode_seqid_op_tail(resp, save, nfserr);
2873 	return nfserr;
2874 }
2875 
2876 static __be32
2877 nfsd4_encode_open_downgrade(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_open_downgrade *od)
2878 {
2879 	ENCODE_SEQID_OP_HEAD;
2880 
2881 	if (!nfserr)
2882 		nfsd4_encode_stateid(resp, &od->od_stateid);
2883 
2884 	encode_seqid_op_tail(resp, save, nfserr);
2885 	return nfserr;
2886 }
2887 
2888 static __be32
2889 nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr,
2890 		  struct nfsd4_read *read)
2891 {
2892 	u32 eof;
2893 	int v, pn;
2894 	unsigned long maxcount;
2895 	long len;
2896 	__be32 *p;
2897 
2898 	if (nfserr)
2899 		return nfserr;
2900 	if (resp->xbuf->page_len)
2901 		return nfserr_resource;
2902 
2903 	RESERVE_SPACE(8); /* eof flag and byte count */
2904 
2905 	maxcount = svc_max_payload(resp->rqstp);
2906 	if (maxcount > read->rd_length)
2907 		maxcount = read->rd_length;
2908 
2909 	len = maxcount;
2910 	v = 0;
2911 	while (len > 0) {
2912 		pn = resp->rqstp->rq_resused++;
2913 		resp->rqstp->rq_vec[v].iov_base =
2914 			page_address(resp->rqstp->rq_respages[pn]);
2915 		resp->rqstp->rq_vec[v].iov_len =
2916 			len < PAGE_SIZE ? len : PAGE_SIZE;
2917 		v++;
2918 		len -= PAGE_SIZE;
2919 	}
2920 	read->rd_vlen = v;
2921 
2922 	nfserr = nfsd_read_file(read->rd_rqstp, read->rd_fhp, read->rd_filp,
2923 			read->rd_offset, resp->rqstp->rq_vec, read->rd_vlen,
2924 			&maxcount);
2925 
2926 	if (nfserr)
2927 		return nfserr;
2928 	eof = (read->rd_offset + maxcount >=
2929 	       read->rd_fhp->fh_dentry->d_inode->i_size);
2930 
2931 	WRITE32(eof);
2932 	WRITE32(maxcount);
2933 	ADJUST_ARGS();
2934 	resp->xbuf->head[0].iov_len = (char*)p
2935 					- (char*)resp->xbuf->head[0].iov_base;
2936 	resp->xbuf->page_len = maxcount;
2937 
2938 	/* Use rest of head for padding and remaining ops: */
2939 	resp->xbuf->tail[0].iov_base = p;
2940 	resp->xbuf->tail[0].iov_len = 0;
2941 	if (maxcount&3) {
2942 		RESERVE_SPACE(4);
2943 		WRITE32(0);
2944 		resp->xbuf->tail[0].iov_base += maxcount&3;
2945 		resp->xbuf->tail[0].iov_len = 4 - (maxcount&3);
2946 		ADJUST_ARGS();
2947 	}
2948 	return 0;
2949 }
2950 
2951 static __be32
2952 nfsd4_encode_readlink(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_readlink *readlink)
2953 {
2954 	int maxcount;
2955 	char *page;
2956 	__be32 *p;
2957 
2958 	if (nfserr)
2959 		return nfserr;
2960 	if (resp->xbuf->page_len)
2961 		return nfserr_resource;
2962 
2963 	page = page_address(resp->rqstp->rq_respages[resp->rqstp->rq_resused++]);
2964 
2965 	maxcount = PAGE_SIZE;
2966 	RESERVE_SPACE(4);
2967 
2968 	/*
2969 	 * XXX: By default, the ->readlink() VFS op will truncate symlinks
2970 	 * if they would overflow the buffer.  Is this kosher in NFSv4?  If
2971 	 * not, one easy fix is: if ->readlink() precisely fills the buffer,
2972 	 * assume that truncation occurred, and return NFS4ERR_RESOURCE.
2973 	 */
2974 	nfserr = nfsd_readlink(readlink->rl_rqstp, readlink->rl_fhp, page, &maxcount);
2975 	if (nfserr == nfserr_isdir)
2976 		return nfserr_inval;
2977 	if (nfserr)
2978 		return nfserr;
2979 
2980 	WRITE32(maxcount);
2981 	ADJUST_ARGS();
2982 	resp->xbuf->head[0].iov_len = (char*)p
2983 				- (char*)resp->xbuf->head[0].iov_base;
2984 	resp->xbuf->page_len = maxcount;
2985 
2986 	/* Use rest of head for padding and remaining ops: */
2987 	resp->xbuf->tail[0].iov_base = p;
2988 	resp->xbuf->tail[0].iov_len = 0;
2989 	if (maxcount&3) {
2990 		RESERVE_SPACE(4);
2991 		WRITE32(0);
2992 		resp->xbuf->tail[0].iov_base += maxcount&3;
2993 		resp->xbuf->tail[0].iov_len = 4 - (maxcount&3);
2994 		ADJUST_ARGS();
2995 	}
2996 	return 0;
2997 }
2998 
2999 static __be32
3000 nfsd4_encode_readdir(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_readdir *readdir)
3001 {
3002 	int maxcount;
3003 	loff_t offset;
3004 	__be32 *page, *savep, *tailbase;
3005 	__be32 *p;
3006 
3007 	if (nfserr)
3008 		return nfserr;
3009 	if (resp->xbuf->page_len)
3010 		return nfserr_resource;
3011 
3012 	RESERVE_SPACE(8);  /* verifier */
3013 	savep = p;
3014 
3015 	/* XXX: Following NFSv3, we ignore the READDIR verifier for now. */
3016 	WRITE32(0);
3017 	WRITE32(0);
3018 	ADJUST_ARGS();
3019 	resp->xbuf->head[0].iov_len = ((char*)resp->p) - (char*)resp->xbuf->head[0].iov_base;
3020 	tailbase = p;
3021 
3022 	maxcount = PAGE_SIZE;
3023 	if (maxcount > readdir->rd_maxcount)
3024 		maxcount = readdir->rd_maxcount;
3025 
3026 	/*
3027 	 * Convert from bytes to words, account for the two words already
3028 	 * written, make sure to leave two words at the end for the next
3029 	 * pointer and eof field.
3030 	 */
3031 	maxcount = (maxcount >> 2) - 4;
3032 	if (maxcount < 0) {
3033 		nfserr =  nfserr_toosmall;
3034 		goto err_no_verf;
3035 	}
3036 
3037 	page = page_address(resp->rqstp->rq_respages[resp->rqstp->rq_resused++]);
3038 	readdir->common.err = 0;
3039 	readdir->buflen = maxcount;
3040 	readdir->buffer = page;
3041 	readdir->offset = NULL;
3042 
3043 	offset = readdir->rd_cookie;
3044 	nfserr = nfsd_readdir(readdir->rd_rqstp, readdir->rd_fhp,
3045 			      &offset,
3046 			      &readdir->common, nfsd4_encode_dirent);
3047 	if (nfserr == nfs_ok &&
3048 	    readdir->common.err == nfserr_toosmall &&
3049 	    readdir->buffer == page)
3050 		nfserr = nfserr_toosmall;
3051 	if (nfserr)
3052 		goto err_no_verf;
3053 
3054 	if (readdir->offset)
3055 		xdr_encode_hyper(readdir->offset, offset);
3056 
3057 	p = readdir->buffer;
3058 	*p++ = 0;	/* no more entries */
3059 	*p++ = htonl(readdir->common.err == nfserr_eof);
3060 	resp->xbuf->page_len = ((char*)p) - (char*)page_address(
3061 		resp->rqstp->rq_respages[resp->rqstp->rq_resused-1]);
3062 
3063 	/* Use rest of head for padding and remaining ops: */
3064 	resp->xbuf->tail[0].iov_base = tailbase;
3065 	resp->xbuf->tail[0].iov_len = 0;
3066 	resp->p = resp->xbuf->tail[0].iov_base;
3067 	resp->end = resp->p + (PAGE_SIZE - resp->xbuf->head[0].iov_len)/4;
3068 
3069 	return 0;
3070 err_no_verf:
3071 	p = savep;
3072 	ADJUST_ARGS();
3073 	return nfserr;
3074 }
3075 
3076 static __be32
3077 nfsd4_encode_remove(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_remove *remove)
3078 {
3079 	__be32 *p;
3080 
3081 	if (!nfserr) {
3082 		RESERVE_SPACE(20);
3083 		write_cinfo(&p, &remove->rm_cinfo);
3084 		ADJUST_ARGS();
3085 	}
3086 	return nfserr;
3087 }
3088 
3089 static __be32
3090 nfsd4_encode_rename(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_rename *rename)
3091 {
3092 	__be32 *p;
3093 
3094 	if (!nfserr) {
3095 		RESERVE_SPACE(40);
3096 		write_cinfo(&p, &rename->rn_sinfo);
3097 		write_cinfo(&p, &rename->rn_tinfo);
3098 		ADJUST_ARGS();
3099 	}
3100 	return nfserr;
3101 }
3102 
3103 static __be32
3104 nfsd4_do_encode_secinfo(struct nfsd4_compoundres *resp,
3105 			 __be32 nfserr,struct svc_export *exp)
3106 {
3107 	int i = 0;
3108 	u32 nflavs;
3109 	struct exp_flavor_info *flavs;
3110 	struct exp_flavor_info def_flavs[2];
3111 	__be32 *p;
3112 
3113 	if (nfserr)
3114 		goto out;
3115 	if (exp->ex_nflavors) {
3116 		flavs = exp->ex_flavors;
3117 		nflavs = exp->ex_nflavors;
3118 	} else { /* Handling of some defaults in absence of real secinfo: */
3119 		flavs = def_flavs;
3120 		if (exp->ex_client->flavour->flavour == RPC_AUTH_UNIX) {
3121 			nflavs = 2;
3122 			flavs[0].pseudoflavor = RPC_AUTH_UNIX;
3123 			flavs[1].pseudoflavor = RPC_AUTH_NULL;
3124 		} else if (exp->ex_client->flavour->flavour == RPC_AUTH_GSS) {
3125 			nflavs = 1;
3126 			flavs[0].pseudoflavor
3127 					= svcauth_gss_flavor(exp->ex_client);
3128 		} else {
3129 			nflavs = 1;
3130 			flavs[0].pseudoflavor
3131 					= exp->ex_client->flavour->flavour;
3132 		}
3133 	}
3134 
3135 	RESERVE_SPACE(4);
3136 	WRITE32(nflavs);
3137 	ADJUST_ARGS();
3138 	for (i = 0; i < nflavs; i++) {
3139 		u32 flav = flavs[i].pseudoflavor;
3140 		struct gss_api_mech *gm = gss_mech_get_by_pseudoflavor(flav);
3141 
3142 		if (gm) {
3143 			RESERVE_SPACE(4);
3144 			WRITE32(RPC_AUTH_GSS);
3145 			ADJUST_ARGS();
3146 			RESERVE_SPACE(4 + gm->gm_oid.len);
3147 			WRITE32(gm->gm_oid.len);
3148 			WRITEMEM(gm->gm_oid.data, gm->gm_oid.len);
3149 			ADJUST_ARGS();
3150 			RESERVE_SPACE(4);
3151 			WRITE32(0); /* qop */
3152 			ADJUST_ARGS();
3153 			RESERVE_SPACE(4);
3154 			WRITE32(gss_pseudoflavor_to_service(gm, flav));
3155 			ADJUST_ARGS();
3156 			gss_mech_put(gm);
3157 		} else {
3158 			RESERVE_SPACE(4);
3159 			WRITE32(flav);
3160 			ADJUST_ARGS();
3161 		}
3162 	}
3163 out:
3164 	if (exp)
3165 		exp_put(exp);
3166 	return nfserr;
3167 }
3168 
3169 static __be32
3170 nfsd4_encode_secinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
3171 		     struct nfsd4_secinfo *secinfo)
3172 {
3173 	return nfsd4_do_encode_secinfo(resp, nfserr, secinfo->si_exp);
3174 }
3175 
3176 static __be32
3177 nfsd4_encode_secinfo_no_name(struct nfsd4_compoundres *resp, __be32 nfserr,
3178 		     struct nfsd4_secinfo_no_name *secinfo)
3179 {
3180 	return nfsd4_do_encode_secinfo(resp, nfserr, secinfo->sin_exp);
3181 }
3182 
3183 /*
3184  * The SETATTR encode routine is special -- it always encodes a bitmap,
3185  * regardless of the error status.
3186  */
3187 static __be32
3188 nfsd4_encode_setattr(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_setattr *setattr)
3189 {
3190 	__be32 *p;
3191 
3192 	RESERVE_SPACE(12);
3193 	if (nfserr) {
3194 		WRITE32(2);
3195 		WRITE32(0);
3196 		WRITE32(0);
3197 	}
3198 	else {
3199 		WRITE32(2);
3200 		WRITE32(setattr->sa_bmval[0]);
3201 		WRITE32(setattr->sa_bmval[1]);
3202 	}
3203 	ADJUST_ARGS();
3204 	return nfserr;
3205 }
3206 
3207 static __be32
3208 nfsd4_encode_setclientid(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_setclientid *scd)
3209 {
3210 	__be32 *p;
3211 
3212 	if (!nfserr) {
3213 		RESERVE_SPACE(8 + sizeof(nfs4_verifier));
3214 		WRITEMEM(&scd->se_clientid, 8);
3215 		WRITEMEM(&scd->se_confirm, sizeof(nfs4_verifier));
3216 		ADJUST_ARGS();
3217 	}
3218 	else if (nfserr == nfserr_clid_inuse) {
3219 		RESERVE_SPACE(8);
3220 		WRITE32(0);
3221 		WRITE32(0);
3222 		ADJUST_ARGS();
3223 	}
3224 	return nfserr;
3225 }
3226 
3227 static __be32
3228 nfsd4_encode_write(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_write *write)
3229 {
3230 	__be32 *p;
3231 
3232 	if (!nfserr) {
3233 		RESERVE_SPACE(16);
3234 		WRITE32(write->wr_bytes_written);
3235 		WRITE32(write->wr_how_written);
3236 		WRITEMEM(write->wr_verifier.data, 8);
3237 		ADJUST_ARGS();
3238 	}
3239 	return nfserr;
3240 }
3241 
3242 static __be32
3243 nfsd4_encode_exchange_id(struct nfsd4_compoundres *resp, int nfserr,
3244 			 struct nfsd4_exchange_id *exid)
3245 {
3246 	__be32 *p;
3247 	char *major_id;
3248 	char *server_scope;
3249 	int major_id_sz;
3250 	int server_scope_sz;
3251 	uint64_t minor_id = 0;
3252 
3253 	if (nfserr)
3254 		return nfserr;
3255 
3256 	major_id = utsname()->nodename;
3257 	major_id_sz = strlen(major_id);
3258 	server_scope = utsname()->nodename;
3259 	server_scope_sz = strlen(server_scope);
3260 
3261 	RESERVE_SPACE(
3262 		8 /* eir_clientid */ +
3263 		4 /* eir_sequenceid */ +
3264 		4 /* eir_flags */ +
3265 		4 /* spr_how (SP4_NONE) */ +
3266 		8 /* so_minor_id */ +
3267 		4 /* so_major_id.len */ +
3268 		(XDR_QUADLEN(major_id_sz) * 4) +
3269 		4 /* eir_server_scope.len */ +
3270 		(XDR_QUADLEN(server_scope_sz) * 4) +
3271 		4 /* eir_server_impl_id.count (0) */);
3272 
3273 	WRITEMEM(&exid->clientid, 8);
3274 	WRITE32(exid->seqid);
3275 	WRITE32(exid->flags);
3276 
3277 	/* state_protect4_r. Currently only support SP4_NONE */
3278 	BUG_ON(exid->spa_how != SP4_NONE);
3279 	WRITE32(exid->spa_how);
3280 
3281 	/* The server_owner struct */
3282 	WRITE64(minor_id);      /* Minor id */
3283 	/* major id */
3284 	WRITE32(major_id_sz);
3285 	WRITEMEM(major_id, major_id_sz);
3286 
3287 	/* Server scope */
3288 	WRITE32(server_scope_sz);
3289 	WRITEMEM(server_scope, server_scope_sz);
3290 
3291 	/* Implementation id */
3292 	WRITE32(0);	/* zero length nfs_impl_id4 array */
3293 	ADJUST_ARGS();
3294 	return 0;
3295 }
3296 
3297 static __be32
3298 nfsd4_encode_create_session(struct nfsd4_compoundres *resp, int nfserr,
3299 			    struct nfsd4_create_session *sess)
3300 {
3301 	__be32 *p;
3302 
3303 	if (nfserr)
3304 		return nfserr;
3305 
3306 	RESERVE_SPACE(24);
3307 	WRITEMEM(sess->sessionid.data, NFS4_MAX_SESSIONID_LEN);
3308 	WRITE32(sess->seqid);
3309 	WRITE32(sess->flags);
3310 	ADJUST_ARGS();
3311 
3312 	RESERVE_SPACE(28);
3313 	WRITE32(0); /* headerpadsz */
3314 	WRITE32(sess->fore_channel.maxreq_sz);
3315 	WRITE32(sess->fore_channel.maxresp_sz);
3316 	WRITE32(sess->fore_channel.maxresp_cached);
3317 	WRITE32(sess->fore_channel.maxops);
3318 	WRITE32(sess->fore_channel.maxreqs);
3319 	WRITE32(sess->fore_channel.nr_rdma_attrs);
3320 	ADJUST_ARGS();
3321 
3322 	if (sess->fore_channel.nr_rdma_attrs) {
3323 		RESERVE_SPACE(4);
3324 		WRITE32(sess->fore_channel.rdma_attrs);
3325 		ADJUST_ARGS();
3326 	}
3327 
3328 	RESERVE_SPACE(28);
3329 	WRITE32(0); /* headerpadsz */
3330 	WRITE32(sess->back_channel.maxreq_sz);
3331 	WRITE32(sess->back_channel.maxresp_sz);
3332 	WRITE32(sess->back_channel.maxresp_cached);
3333 	WRITE32(sess->back_channel.maxops);
3334 	WRITE32(sess->back_channel.maxreqs);
3335 	WRITE32(sess->back_channel.nr_rdma_attrs);
3336 	ADJUST_ARGS();
3337 
3338 	if (sess->back_channel.nr_rdma_attrs) {
3339 		RESERVE_SPACE(4);
3340 		WRITE32(sess->back_channel.rdma_attrs);
3341 		ADJUST_ARGS();
3342 	}
3343 	return 0;
3344 }
3345 
3346 static __be32
3347 nfsd4_encode_destroy_session(struct nfsd4_compoundres *resp, int nfserr,
3348 			     struct nfsd4_destroy_session *destroy_session)
3349 {
3350 	return nfserr;
3351 }
3352 
3353 static __be32
3354 nfsd4_encode_free_stateid(struct nfsd4_compoundres *resp, int nfserr,
3355 			  struct nfsd4_free_stateid *free_stateid)
3356 {
3357 	__be32 *p;
3358 
3359 	if (nfserr)
3360 		return nfserr;
3361 
3362 	RESERVE_SPACE(4);
3363 	WRITE32(nfserr);
3364 	ADJUST_ARGS();
3365 	return nfserr;
3366 }
3367 
3368 static __be32
3369 nfsd4_encode_sequence(struct nfsd4_compoundres *resp, int nfserr,
3370 		      struct nfsd4_sequence *seq)
3371 {
3372 	__be32 *p;
3373 
3374 	if (nfserr)
3375 		return nfserr;
3376 
3377 	RESERVE_SPACE(NFS4_MAX_SESSIONID_LEN + 20);
3378 	WRITEMEM(seq->sessionid.data, NFS4_MAX_SESSIONID_LEN);
3379 	WRITE32(seq->seqid);
3380 	WRITE32(seq->slotid);
3381 	/* Note slotid's are numbered from zero: */
3382 	WRITE32(seq->maxslots - 1); /* sr_highest_slotid */
3383 	WRITE32(seq->maxslots - 1); /* sr_target_highest_slotid */
3384 	WRITE32(seq->status_flags);
3385 
3386 	ADJUST_ARGS();
3387 	resp->cstate.datap = p; /* DRC cache data pointer */
3388 	return 0;
3389 }
3390 
3391 __be32
3392 nfsd4_encode_test_stateid(struct nfsd4_compoundres *resp, int nfserr,
3393 			  struct nfsd4_test_stateid *test_stateid)
3394 {
3395 	struct nfsd4_compoundargs *argp;
3396 	struct nfs4_client *cl = resp->cstate.session->se_client;
3397 	stateid_t si;
3398 	__be32 *p;
3399 	int i;
3400 	int valid;
3401 
3402 	restore_buf(test_stateid->ts_saved_args, &test_stateid->ts_savedp);
3403 	argp = test_stateid->ts_saved_args;
3404 
3405 	RESERVE_SPACE(4);
3406 	*p++ = htonl(test_stateid->ts_num_ids);
3407 	resp->p = p;
3408 
3409 	nfs4_lock_state();
3410 	for (i = 0; i < test_stateid->ts_num_ids; i++) {
3411 		nfsd4_decode_stateid(argp, &si);
3412 		valid = nfs4_validate_stateid(cl, &si);
3413 		RESERVE_SPACE(4);
3414 		*p++ = htonl(valid);
3415 		resp->p = p;
3416 	}
3417 	nfs4_unlock_state();
3418 
3419 	return nfserr;
3420 }
3421 
3422 static __be32
3423 nfsd4_encode_noop(struct nfsd4_compoundres *resp, __be32 nfserr, void *p)
3424 {
3425 	return nfserr;
3426 }
3427 
3428 typedef __be32(* nfsd4_enc)(struct nfsd4_compoundres *, __be32, void *);
3429 
3430 /*
3431  * Note: nfsd4_enc_ops vector is shared for v4.0 and v4.1
3432  * since we don't need to filter out obsolete ops as this is
3433  * done in the decoding phase.
3434  */
3435 static nfsd4_enc nfsd4_enc_ops[] = {
3436 	[OP_ACCESS]		= (nfsd4_enc)nfsd4_encode_access,
3437 	[OP_CLOSE]		= (nfsd4_enc)nfsd4_encode_close,
3438 	[OP_COMMIT]		= (nfsd4_enc)nfsd4_encode_commit,
3439 	[OP_CREATE]		= (nfsd4_enc)nfsd4_encode_create,
3440 	[OP_DELEGPURGE]		= (nfsd4_enc)nfsd4_encode_noop,
3441 	[OP_DELEGRETURN]	= (nfsd4_enc)nfsd4_encode_noop,
3442 	[OP_GETATTR]		= (nfsd4_enc)nfsd4_encode_getattr,
3443 	[OP_GETFH]		= (nfsd4_enc)nfsd4_encode_getfh,
3444 	[OP_LINK]		= (nfsd4_enc)nfsd4_encode_link,
3445 	[OP_LOCK]		= (nfsd4_enc)nfsd4_encode_lock,
3446 	[OP_LOCKT]		= (nfsd4_enc)nfsd4_encode_lockt,
3447 	[OP_LOCKU]		= (nfsd4_enc)nfsd4_encode_locku,
3448 	[OP_LOOKUP]		= (nfsd4_enc)nfsd4_encode_noop,
3449 	[OP_LOOKUPP]		= (nfsd4_enc)nfsd4_encode_noop,
3450 	[OP_NVERIFY]		= (nfsd4_enc)nfsd4_encode_noop,
3451 	[OP_OPEN]		= (nfsd4_enc)nfsd4_encode_open,
3452 	[OP_OPENATTR]		= (nfsd4_enc)nfsd4_encode_noop,
3453 	[OP_OPEN_CONFIRM]	= (nfsd4_enc)nfsd4_encode_open_confirm,
3454 	[OP_OPEN_DOWNGRADE]	= (nfsd4_enc)nfsd4_encode_open_downgrade,
3455 	[OP_PUTFH]		= (nfsd4_enc)nfsd4_encode_noop,
3456 	[OP_PUTPUBFH]		= (nfsd4_enc)nfsd4_encode_noop,
3457 	[OP_PUTROOTFH]		= (nfsd4_enc)nfsd4_encode_noop,
3458 	[OP_READ]		= (nfsd4_enc)nfsd4_encode_read,
3459 	[OP_READDIR]		= (nfsd4_enc)nfsd4_encode_readdir,
3460 	[OP_READLINK]		= (nfsd4_enc)nfsd4_encode_readlink,
3461 	[OP_REMOVE]		= (nfsd4_enc)nfsd4_encode_remove,
3462 	[OP_RENAME]		= (nfsd4_enc)nfsd4_encode_rename,
3463 	[OP_RENEW]		= (nfsd4_enc)nfsd4_encode_noop,
3464 	[OP_RESTOREFH]		= (nfsd4_enc)nfsd4_encode_noop,
3465 	[OP_SAVEFH]		= (nfsd4_enc)nfsd4_encode_noop,
3466 	[OP_SECINFO]		= (nfsd4_enc)nfsd4_encode_secinfo,
3467 	[OP_SETATTR]		= (nfsd4_enc)nfsd4_encode_setattr,
3468 	[OP_SETCLIENTID]	= (nfsd4_enc)nfsd4_encode_setclientid,
3469 	[OP_SETCLIENTID_CONFIRM] = (nfsd4_enc)nfsd4_encode_noop,
3470 	[OP_VERIFY]		= (nfsd4_enc)nfsd4_encode_noop,
3471 	[OP_WRITE]		= (nfsd4_enc)nfsd4_encode_write,
3472 	[OP_RELEASE_LOCKOWNER]	= (nfsd4_enc)nfsd4_encode_noop,
3473 
3474 	/* NFSv4.1 operations */
3475 	[OP_BACKCHANNEL_CTL]	= (nfsd4_enc)nfsd4_encode_noop,
3476 	[OP_BIND_CONN_TO_SESSION] = (nfsd4_enc)nfsd4_encode_bind_conn_to_session,
3477 	[OP_EXCHANGE_ID]	= (nfsd4_enc)nfsd4_encode_exchange_id,
3478 	[OP_CREATE_SESSION]	= (nfsd4_enc)nfsd4_encode_create_session,
3479 	[OP_DESTROY_SESSION]	= (nfsd4_enc)nfsd4_encode_destroy_session,
3480 	[OP_FREE_STATEID]	= (nfsd4_enc)nfsd4_encode_free_stateid,
3481 	[OP_GET_DIR_DELEGATION]	= (nfsd4_enc)nfsd4_encode_noop,
3482 	[OP_GETDEVICEINFO]	= (nfsd4_enc)nfsd4_encode_noop,
3483 	[OP_GETDEVICELIST]	= (nfsd4_enc)nfsd4_encode_noop,
3484 	[OP_LAYOUTCOMMIT]	= (nfsd4_enc)nfsd4_encode_noop,
3485 	[OP_LAYOUTGET]		= (nfsd4_enc)nfsd4_encode_noop,
3486 	[OP_LAYOUTRETURN]	= (nfsd4_enc)nfsd4_encode_noop,
3487 	[OP_SECINFO_NO_NAME]	= (nfsd4_enc)nfsd4_encode_secinfo_no_name,
3488 	[OP_SEQUENCE]		= (nfsd4_enc)nfsd4_encode_sequence,
3489 	[OP_SET_SSV]		= (nfsd4_enc)nfsd4_encode_noop,
3490 	[OP_TEST_STATEID]	= (nfsd4_enc)nfsd4_encode_test_stateid,
3491 	[OP_WANT_DELEGATION]	= (nfsd4_enc)nfsd4_encode_noop,
3492 	[OP_DESTROY_CLIENTID]	= (nfsd4_enc)nfsd4_encode_noop,
3493 	[OP_RECLAIM_COMPLETE]	= (nfsd4_enc)nfsd4_encode_noop,
3494 };
3495 
3496 /*
3497  * Calculate the total amount of memory that the compound response has taken
3498  * after encoding the current operation with pad.
3499  *
3500  * pad: if operation is non-idempotent, pad was calculate by op_rsize_bop()
3501  *      which was specified at nfsd4_operation, else pad is zero.
3502  *
3503  * Compare this length to the session se_fmaxresp_sz and se_fmaxresp_cached.
3504  *
3505  * Our se_fmaxresp_cached will always be a multiple of PAGE_SIZE, and so
3506  * will be at least a page and will therefore hold the xdr_buf head.
3507  */
3508 int nfsd4_check_resp_size(struct nfsd4_compoundres *resp, u32 pad)
3509 {
3510 	struct xdr_buf *xb = &resp->rqstp->rq_res;
3511 	struct nfsd4_session *session = NULL;
3512 	struct nfsd4_slot *slot = resp->cstate.slot;
3513 	u32 length, tlen = 0;
3514 
3515 	if (!nfsd4_has_session(&resp->cstate))
3516 		return 0;
3517 
3518 	session = resp->cstate.session;
3519 	if (session == NULL)
3520 		return 0;
3521 
3522 	if (xb->page_len == 0) {
3523 		length = (char *)resp->p - (char *)xb->head[0].iov_base + pad;
3524 	} else {
3525 		if (xb->tail[0].iov_base && xb->tail[0].iov_len > 0)
3526 			tlen = (char *)resp->p - (char *)xb->tail[0].iov_base;
3527 
3528 		length = xb->head[0].iov_len + xb->page_len + tlen + pad;
3529 	}
3530 	dprintk("%s length %u, xb->page_len %u tlen %u pad %u\n", __func__,
3531 		length, xb->page_len, tlen, pad);
3532 
3533 	if (length > session->se_fchannel.maxresp_sz)
3534 		return nfserr_rep_too_big;
3535 
3536 	if (slot->sl_cachethis == 1 &&
3537 	    length > session->se_fchannel.maxresp_cached)
3538 		return nfserr_rep_too_big_to_cache;
3539 
3540 	return 0;
3541 }
3542 
3543 void
3544 nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op)
3545 {
3546 	__be32 *statp;
3547 	__be32 *p;
3548 
3549 	RESERVE_SPACE(8);
3550 	WRITE32(op->opnum);
3551 	statp = p++;	/* to be backfilled at the end */
3552 	ADJUST_ARGS();
3553 
3554 	if (op->opnum == OP_ILLEGAL)
3555 		goto status;
3556 	BUG_ON(op->opnum < 0 || op->opnum >= ARRAY_SIZE(nfsd4_enc_ops) ||
3557 	       !nfsd4_enc_ops[op->opnum]);
3558 	op->status = nfsd4_enc_ops[op->opnum](resp, op->status, &op->u);
3559 	/* nfsd4_check_drc_limit guarantees enough room for error status */
3560 	if (!op->status)
3561 		op->status = nfsd4_check_resp_size(resp, 0);
3562 status:
3563 	/*
3564 	 * Note: We write the status directly, instead of using WRITE32(),
3565 	 * since it is already in network byte order.
3566 	 */
3567 	*statp = op->status;
3568 }
3569 
3570 /*
3571  * Encode the reply stored in the stateowner reply cache
3572  *
3573  * XDR note: do not encode rp->rp_buflen: the buffer contains the
3574  * previously sent already encoded operation.
3575  *
3576  * called with nfs4_lock_state() held
3577  */
3578 void
3579 nfsd4_encode_replay(struct nfsd4_compoundres *resp, struct nfsd4_op *op)
3580 {
3581 	__be32 *p;
3582 	struct nfs4_replay *rp = op->replay;
3583 
3584 	BUG_ON(!rp);
3585 
3586 	RESERVE_SPACE(8);
3587 	WRITE32(op->opnum);
3588 	*p++ = rp->rp_status;  /* already xdr'ed */
3589 	ADJUST_ARGS();
3590 
3591 	RESERVE_SPACE(rp->rp_buflen);
3592 	WRITEMEM(rp->rp_buf, rp->rp_buflen);
3593 	ADJUST_ARGS();
3594 }
3595 
3596 int
3597 nfs4svc_encode_voidres(struct svc_rqst *rqstp, __be32 *p, void *dummy)
3598 {
3599         return xdr_ressize_check(rqstp, p);
3600 }
3601 
3602 int nfsd4_release_compoundargs(void *rq, __be32 *p, void *resp)
3603 {
3604 	struct svc_rqst *rqstp = rq;
3605 	struct nfsd4_compoundargs *args = rqstp->rq_argp;
3606 
3607 	if (args->ops != args->iops) {
3608 		kfree(args->ops);
3609 		args->ops = args->iops;
3610 	}
3611 	kfree(args->tmpp);
3612 	args->tmpp = NULL;
3613 	while (args->to_free) {
3614 		struct tmpbuf *tb = args->to_free;
3615 		args->to_free = tb->next;
3616 		tb->release(tb->buf);
3617 		kfree(tb);
3618 	}
3619 	return 1;
3620 }
3621 
3622 int
3623 nfs4svc_decode_compoundargs(struct svc_rqst *rqstp, __be32 *p, struct nfsd4_compoundargs *args)
3624 {
3625 	args->p = p;
3626 	args->end = rqstp->rq_arg.head[0].iov_base + rqstp->rq_arg.head[0].iov_len;
3627 	args->pagelist = rqstp->rq_arg.pages;
3628 	args->pagelen = rqstp->rq_arg.page_len;
3629 	args->tmpp = NULL;
3630 	args->to_free = NULL;
3631 	args->ops = args->iops;
3632 	args->rqstp = rqstp;
3633 
3634 	return !nfsd4_decode_compound(args);
3635 }
3636 
3637 int
3638 nfs4svc_encode_compoundres(struct svc_rqst *rqstp, __be32 *p, struct nfsd4_compoundres *resp)
3639 {
3640 	/*
3641 	 * All that remains is to write the tag and operation count...
3642 	 */
3643 	struct nfsd4_compound_state *cs = &resp->cstate;
3644 	struct kvec *iov;
3645 	p = resp->tagp;
3646 	*p++ = htonl(resp->taglen);
3647 	memcpy(p, resp->tag, resp->taglen);
3648 	p += XDR_QUADLEN(resp->taglen);
3649 	*p++ = htonl(resp->opcnt);
3650 
3651 	if (rqstp->rq_res.page_len)
3652 		iov = &rqstp->rq_res.tail[0];
3653 	else
3654 		iov = &rqstp->rq_res.head[0];
3655 	iov->iov_len = ((char*)resp->p) - (char*)iov->iov_base;
3656 	BUG_ON(iov->iov_len > PAGE_SIZE);
3657 	if (nfsd4_has_session(cs)) {
3658 		if (cs->status != nfserr_replay_cache) {
3659 			nfsd4_store_cache_entry(resp);
3660 			dprintk("%s: SET SLOT STATE TO AVAILABLE\n", __func__);
3661 			cs->slot->sl_inuse = false;
3662 		}
3663 		/* Renew the clientid on success and on replay */
3664 		release_session_client(cs->session);
3665 		nfsd4_put_session(cs->session);
3666 	}
3667 	return 1;
3668 }
3669 
3670 /*
3671  * Local variables:
3672  *  c-basic-offset: 8
3673  * End:
3674  */
3675