xref: /linux/fs/nfsd/nfs4xdr.c (revision 791d3ef2e11100449837dc0b6fe884e60ca3a484)
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 
36 #include <linux/file.h>
37 #include <linux/slab.h>
38 #include <linux/namei.h>
39 #include <linux/statfs.h>
40 #include <linux/utsname.h>
41 #include <linux/pagemap.h>
42 #include <linux/sunrpc/svcauth_gss.h>
43 
44 #include "idmap.h"
45 #include "acl.h"
46 #include "xdr4.h"
47 #include "vfs.h"
48 #include "state.h"
49 #include "cache.h"
50 #include "netns.h"
51 #include "pnfs.h"
52 
53 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
54 #include <linux/security.h>
55 #endif
56 
57 
58 #define NFSDDBG_FACILITY		NFSDDBG_XDR
59 
60 const u32 nfsd_suppattrs[3][3] = {
61 	{NFSD4_SUPPORTED_ATTRS_WORD0,
62 	 NFSD4_SUPPORTED_ATTRS_WORD1,
63 	 NFSD4_SUPPORTED_ATTRS_WORD2},
64 
65 	{NFSD4_1_SUPPORTED_ATTRS_WORD0,
66 	 NFSD4_1_SUPPORTED_ATTRS_WORD1,
67 	 NFSD4_1_SUPPORTED_ATTRS_WORD2},
68 
69 	{NFSD4_1_SUPPORTED_ATTRS_WORD0,
70 	 NFSD4_1_SUPPORTED_ATTRS_WORD1,
71 	 NFSD4_2_SUPPORTED_ATTRS_WORD2},
72 };
73 
74 /*
75  * As per referral draft, the fsid for a referral MUST be different from the fsid of the containing
76  * directory in order to indicate to the client that a filesystem boundary is present
77  * We use a fixed fsid for a referral
78  */
79 #define NFS4_REFERRAL_FSID_MAJOR	0x8000000ULL
80 #define NFS4_REFERRAL_FSID_MINOR	0x8000000ULL
81 
82 static __be32
83 check_filename(char *str, int len)
84 {
85 	int i;
86 
87 	if (len == 0)
88 		return nfserr_inval;
89 	if (isdotent(str, len))
90 		return nfserr_badname;
91 	for (i = 0; i < len; i++)
92 		if (str[i] == '/')
93 			return nfserr_badname;
94 	return 0;
95 }
96 
97 #define DECODE_HEAD				\
98 	__be32 *p;				\
99 	__be32 status
100 #define DECODE_TAIL				\
101 	status = 0;				\
102 out:						\
103 	return status;				\
104 xdr_error:					\
105 	dprintk("NFSD: xdr error (%s:%d)\n",	\
106 			__FILE__, __LINE__);	\
107 	status = nfserr_bad_xdr;		\
108 	goto out
109 
110 #define READMEM(x,nbytes) do {			\
111 	x = (char *)p;				\
112 	p += XDR_QUADLEN(nbytes);		\
113 } while (0)
114 #define SAVEMEM(x,nbytes) do {			\
115 	if (!(x = (p==argp->tmp || p == argp->tmpp) ? \
116  		savemem(argp, p, nbytes) :	\
117  		(char *)p)) {			\
118 		dprintk("NFSD: xdr error (%s:%d)\n", \
119 				__FILE__, __LINE__); \
120 		goto xdr_error;			\
121 		}				\
122 	p += XDR_QUADLEN(nbytes);		\
123 } while (0)
124 #define COPYMEM(x,nbytes) do {			\
125 	memcpy((x), p, nbytes);			\
126 	p += XDR_QUADLEN(nbytes);		\
127 } while (0)
128 
129 /* READ_BUF, read_buf(): nbytes must be <= PAGE_SIZE */
130 #define READ_BUF(nbytes)  do {			\
131 	if (nbytes <= (u32)((char *)argp->end - (char *)argp->p)) {	\
132 		p = argp->p;			\
133 		argp->p += XDR_QUADLEN(nbytes);	\
134 	} else if (!(p = read_buf(argp, nbytes))) { \
135 		dprintk("NFSD: xdr error (%s:%d)\n", \
136 				__FILE__, __LINE__); \
137 		goto xdr_error;			\
138 	}					\
139 } while (0)
140 
141 static void next_decode_page(struct nfsd4_compoundargs *argp)
142 {
143 	argp->p = page_address(argp->pagelist[0]);
144 	argp->pagelist++;
145 	if (argp->pagelen < PAGE_SIZE) {
146 		argp->end = argp->p + XDR_QUADLEN(argp->pagelen);
147 		argp->pagelen = 0;
148 	} else {
149 		argp->end = argp->p + (PAGE_SIZE>>2);
150 		argp->pagelen -= PAGE_SIZE;
151 	}
152 }
153 
154 static __be32 *read_buf(struct nfsd4_compoundargs *argp, u32 nbytes)
155 {
156 	/* We want more bytes than seem to be available.
157 	 * Maybe we need a new page, maybe we have just run out
158 	 */
159 	unsigned int avail = (char *)argp->end - (char *)argp->p;
160 	__be32 *p;
161 
162 	if (argp->pagelen == 0) {
163 		struct kvec *vec = &argp->rqstp->rq_arg.tail[0];
164 
165 		if (!argp->tail) {
166 			argp->tail = true;
167 			avail = vec->iov_len;
168 			argp->p = vec->iov_base;
169 			argp->end = vec->iov_base + avail;
170 		}
171 
172 		if (avail < nbytes)
173 			return NULL;
174 
175 		p = argp->p;
176 		argp->p += XDR_QUADLEN(nbytes);
177 		return p;
178 	}
179 
180 	if (avail + argp->pagelen < nbytes)
181 		return NULL;
182 	if (avail + PAGE_SIZE < nbytes) /* need more than a page !! */
183 		return NULL;
184 	/* ok, we can do it with the current plus the next page */
185 	if (nbytes <= sizeof(argp->tmp))
186 		p = argp->tmp;
187 	else {
188 		kfree(argp->tmpp);
189 		p = argp->tmpp = kmalloc(nbytes, GFP_KERNEL);
190 		if (!p)
191 			return NULL;
192 
193 	}
194 	/*
195 	 * The following memcpy is safe because read_buf is always
196 	 * called with nbytes > avail, and the two cases above both
197 	 * guarantee p points to at least nbytes bytes.
198 	 */
199 	memcpy(p, argp->p, avail);
200 	next_decode_page(argp);
201 	memcpy(((char*)p)+avail, argp->p, (nbytes - avail));
202 	argp->p += XDR_QUADLEN(nbytes - avail);
203 	return p;
204 }
205 
206 static int zero_clientid(clientid_t *clid)
207 {
208 	return (clid->cl_boot == 0) && (clid->cl_id == 0);
209 }
210 
211 /**
212  * svcxdr_tmpalloc - allocate memory to be freed after compound processing
213  * @argp: NFSv4 compound argument structure
214  * @p: pointer to be freed (with kfree())
215  *
216  * Marks @p to be freed when processing the compound operation
217  * described in @argp finishes.
218  */
219 static void *
220 svcxdr_tmpalloc(struct nfsd4_compoundargs *argp, u32 len)
221 {
222 	struct svcxdr_tmpbuf *tb;
223 
224 	tb = kmalloc(sizeof(*tb) + len, GFP_KERNEL);
225 	if (!tb)
226 		return NULL;
227 	tb->next = argp->to_free;
228 	argp->to_free = tb;
229 	return tb->buf;
230 }
231 
232 /*
233  * For xdr strings that need to be passed to other kernel api's
234  * as null-terminated strings.
235  *
236  * Note null-terminating in place usually isn't safe since the
237  * buffer might end on a page boundary.
238  */
239 static char *
240 svcxdr_dupstr(struct nfsd4_compoundargs *argp, void *buf, u32 len)
241 {
242 	char *p = svcxdr_tmpalloc(argp, len + 1);
243 
244 	if (!p)
245 		return NULL;
246 	memcpy(p, buf, len);
247 	p[len] = '\0';
248 	return p;
249 }
250 
251 /**
252  * savemem - duplicate a chunk of memory for later processing
253  * @argp: NFSv4 compound argument structure to be freed with
254  * @p: pointer to be duplicated
255  * @nbytes: length to be duplicated
256  *
257  * Returns a pointer to a copy of @nbytes bytes of memory at @p
258  * that are preserved until processing of the NFSv4 compound
259  * operation described by @argp finishes.
260  */
261 static char *savemem(struct nfsd4_compoundargs *argp, __be32 *p, int nbytes)
262 {
263 	void *ret;
264 
265 	ret = svcxdr_tmpalloc(argp, nbytes);
266 	if (!ret)
267 		return NULL;
268 	memcpy(ret, p, nbytes);
269 	return ret;
270 }
271 
272 /*
273  * We require the high 32 bits of 'seconds' to be 0, and
274  * we ignore all 32 bits of 'nseconds'.
275  */
276 static __be32
277 nfsd4_decode_time(struct nfsd4_compoundargs *argp, struct timespec *tv)
278 {
279 	DECODE_HEAD;
280 	u64 sec;
281 
282 	READ_BUF(12);
283 	p = xdr_decode_hyper(p, &sec);
284 	tv->tv_sec = sec;
285 	tv->tv_nsec = be32_to_cpup(p++);
286 	if (tv->tv_nsec >= (u32)1000000000)
287 		return nfserr_inval;
288 
289 	DECODE_TAIL;
290 }
291 
292 static __be32
293 nfsd4_decode_bitmap(struct nfsd4_compoundargs *argp, u32 *bmval)
294 {
295 	u32 bmlen;
296 	DECODE_HEAD;
297 
298 	bmval[0] = 0;
299 	bmval[1] = 0;
300 	bmval[2] = 0;
301 
302 	READ_BUF(4);
303 	bmlen = be32_to_cpup(p++);
304 	if (bmlen > 1000)
305 		goto xdr_error;
306 
307 	READ_BUF(bmlen << 2);
308 	if (bmlen > 0)
309 		bmval[0] = be32_to_cpup(p++);
310 	if (bmlen > 1)
311 		bmval[1] = be32_to_cpup(p++);
312 	if (bmlen > 2)
313 		bmval[2] = be32_to_cpup(p++);
314 
315 	DECODE_TAIL;
316 }
317 
318 static __be32
319 nfsd4_decode_fattr(struct nfsd4_compoundargs *argp, u32 *bmval,
320 		   struct iattr *iattr, struct nfs4_acl **acl,
321 		   struct xdr_netobj *label, int *umask)
322 {
323 	struct timespec ts;
324 	int expected_len, len = 0;
325 	u32 dummy32;
326 	char *buf;
327 
328 	DECODE_HEAD;
329 	iattr->ia_valid = 0;
330 	if ((status = nfsd4_decode_bitmap(argp, bmval)))
331 		return status;
332 
333 	if (bmval[0] & ~NFSD_WRITEABLE_ATTRS_WORD0
334 	    || bmval[1] & ~NFSD_WRITEABLE_ATTRS_WORD1
335 	    || bmval[2] & ~NFSD_WRITEABLE_ATTRS_WORD2) {
336 		if (nfsd_attrs_supported(argp->minorversion, bmval))
337 			return nfserr_inval;
338 		return nfserr_attrnotsupp;
339 	}
340 
341 	READ_BUF(4);
342 	expected_len = be32_to_cpup(p++);
343 
344 	if (bmval[0] & FATTR4_WORD0_SIZE) {
345 		READ_BUF(8);
346 		len += 8;
347 		p = xdr_decode_hyper(p, &iattr->ia_size);
348 		iattr->ia_valid |= ATTR_SIZE;
349 	}
350 	if (bmval[0] & FATTR4_WORD0_ACL) {
351 		u32 nace;
352 		struct nfs4_ace *ace;
353 
354 		READ_BUF(4); len += 4;
355 		nace = be32_to_cpup(p++);
356 
357 		if (nace > NFS4_ACL_MAX)
358 			return nfserr_fbig;
359 
360 		*acl = svcxdr_tmpalloc(argp, nfs4_acl_bytes(nace));
361 		if (*acl == NULL)
362 			return nfserr_jukebox;
363 
364 		(*acl)->naces = nace;
365 		for (ace = (*acl)->aces; ace < (*acl)->aces + nace; ace++) {
366 			READ_BUF(16); len += 16;
367 			ace->type = be32_to_cpup(p++);
368 			ace->flag = be32_to_cpup(p++);
369 			ace->access_mask = be32_to_cpup(p++);
370 			dummy32 = be32_to_cpup(p++);
371 			READ_BUF(dummy32);
372 			len += XDR_QUADLEN(dummy32) << 2;
373 			READMEM(buf, dummy32);
374 			ace->whotype = nfs4_acl_get_whotype(buf, dummy32);
375 			status = nfs_ok;
376 			if (ace->whotype != NFS4_ACL_WHO_NAMED)
377 				;
378 			else if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP)
379 				status = nfsd_map_name_to_gid(argp->rqstp,
380 						buf, dummy32, &ace->who_gid);
381 			else
382 				status = nfsd_map_name_to_uid(argp->rqstp,
383 						buf, dummy32, &ace->who_uid);
384 			if (status)
385 				return status;
386 		}
387 	} else
388 		*acl = NULL;
389 	if (bmval[1] & FATTR4_WORD1_MODE) {
390 		READ_BUF(4);
391 		len += 4;
392 		iattr->ia_mode = be32_to_cpup(p++);
393 		iattr->ia_mode &= (S_IFMT | S_IALLUGO);
394 		iattr->ia_valid |= ATTR_MODE;
395 	}
396 	if (bmval[1] & FATTR4_WORD1_OWNER) {
397 		READ_BUF(4);
398 		len += 4;
399 		dummy32 = be32_to_cpup(p++);
400 		READ_BUF(dummy32);
401 		len += (XDR_QUADLEN(dummy32) << 2);
402 		READMEM(buf, dummy32);
403 		if ((status = nfsd_map_name_to_uid(argp->rqstp, buf, dummy32, &iattr->ia_uid)))
404 			return status;
405 		iattr->ia_valid |= ATTR_UID;
406 	}
407 	if (bmval[1] & FATTR4_WORD1_OWNER_GROUP) {
408 		READ_BUF(4);
409 		len += 4;
410 		dummy32 = be32_to_cpup(p++);
411 		READ_BUF(dummy32);
412 		len += (XDR_QUADLEN(dummy32) << 2);
413 		READMEM(buf, dummy32);
414 		if ((status = nfsd_map_name_to_gid(argp->rqstp, buf, dummy32, &iattr->ia_gid)))
415 			return status;
416 		iattr->ia_valid |= ATTR_GID;
417 	}
418 	if (bmval[1] & FATTR4_WORD1_TIME_ACCESS_SET) {
419 		READ_BUF(4);
420 		len += 4;
421 		dummy32 = be32_to_cpup(p++);
422 		switch (dummy32) {
423 		case NFS4_SET_TO_CLIENT_TIME:
424 			len += 12;
425 			status = nfsd4_decode_time(argp, &ts);
426 			iattr->ia_atime = timespec_to_timespec64(ts);
427 			if (status)
428 				return status;
429 			iattr->ia_valid |= (ATTR_ATIME | ATTR_ATIME_SET);
430 			break;
431 		case NFS4_SET_TO_SERVER_TIME:
432 			iattr->ia_valid |= ATTR_ATIME;
433 			break;
434 		default:
435 			goto xdr_error;
436 		}
437 	}
438 	if (bmval[1] & FATTR4_WORD1_TIME_MODIFY_SET) {
439 		READ_BUF(4);
440 		len += 4;
441 		dummy32 = be32_to_cpup(p++);
442 		switch (dummy32) {
443 		case NFS4_SET_TO_CLIENT_TIME:
444 			len += 12;
445 			status = nfsd4_decode_time(argp, &ts);
446 			iattr->ia_mtime = timespec_to_timespec64(ts);
447 			if (status)
448 				return status;
449 			iattr->ia_valid |= (ATTR_MTIME | ATTR_MTIME_SET);
450 			break;
451 		case NFS4_SET_TO_SERVER_TIME:
452 			iattr->ia_valid |= ATTR_MTIME;
453 			break;
454 		default:
455 			goto xdr_error;
456 		}
457 	}
458 
459 	label->len = 0;
460 	if (IS_ENABLED(CONFIG_NFSD_V4_SECURITY_LABEL) &&
461 	    bmval[2] & FATTR4_WORD2_SECURITY_LABEL) {
462 		READ_BUF(4);
463 		len += 4;
464 		dummy32 = be32_to_cpup(p++); /* lfs: we don't use it */
465 		READ_BUF(4);
466 		len += 4;
467 		dummy32 = be32_to_cpup(p++); /* pi: we don't use it either */
468 		READ_BUF(4);
469 		len += 4;
470 		dummy32 = be32_to_cpup(p++);
471 		READ_BUF(dummy32);
472 		if (dummy32 > NFS4_MAXLABELLEN)
473 			return nfserr_badlabel;
474 		len += (XDR_QUADLEN(dummy32) << 2);
475 		READMEM(buf, dummy32);
476 		label->len = dummy32;
477 		label->data = svcxdr_dupstr(argp, buf, dummy32);
478 		if (!label->data)
479 			return nfserr_jukebox;
480 	}
481 	if (bmval[2] & FATTR4_WORD2_MODE_UMASK) {
482 		if (!umask)
483 			goto xdr_error;
484 		READ_BUF(8);
485 		len += 8;
486 		dummy32 = be32_to_cpup(p++);
487 		iattr->ia_mode = dummy32 & (S_IFMT | S_IALLUGO);
488 		dummy32 = be32_to_cpup(p++);
489 		*umask = dummy32 & S_IRWXUGO;
490 		iattr->ia_valid |= ATTR_MODE;
491 	}
492 	if (len != expected_len)
493 		goto xdr_error;
494 
495 	DECODE_TAIL;
496 }
497 
498 static __be32
499 nfsd4_decode_stateid(struct nfsd4_compoundargs *argp, stateid_t *sid)
500 {
501 	DECODE_HEAD;
502 
503 	READ_BUF(sizeof(stateid_t));
504 	sid->si_generation = be32_to_cpup(p++);
505 	COPYMEM(&sid->si_opaque, sizeof(stateid_opaque_t));
506 
507 	DECODE_TAIL;
508 }
509 
510 static __be32
511 nfsd4_decode_access(struct nfsd4_compoundargs *argp, struct nfsd4_access *access)
512 {
513 	DECODE_HEAD;
514 
515 	READ_BUF(4);
516 	access->ac_req_access = be32_to_cpup(p++);
517 
518 	DECODE_TAIL;
519 }
520 
521 static __be32 nfsd4_decode_cb_sec(struct nfsd4_compoundargs *argp, struct nfsd4_cb_sec *cbs)
522 {
523 	DECODE_HEAD;
524 	u32 dummy, uid, gid;
525 	char *machine_name;
526 	int i;
527 	int nr_secflavs;
528 
529 	/* callback_sec_params4 */
530 	READ_BUF(4);
531 	nr_secflavs = be32_to_cpup(p++);
532 	if (nr_secflavs)
533 		cbs->flavor = (u32)(-1);
534 	else
535 		/* Is this legal? Be generous, take it to mean AUTH_NONE: */
536 		cbs->flavor = 0;
537 	for (i = 0; i < nr_secflavs; ++i) {
538 		READ_BUF(4);
539 		dummy = be32_to_cpup(p++);
540 		switch (dummy) {
541 		case RPC_AUTH_NULL:
542 			/* Nothing to read */
543 			if (cbs->flavor == (u32)(-1))
544 				cbs->flavor = RPC_AUTH_NULL;
545 			break;
546 		case RPC_AUTH_UNIX:
547 			READ_BUF(8);
548 			/* stamp */
549 			dummy = be32_to_cpup(p++);
550 
551 			/* machine name */
552 			dummy = be32_to_cpup(p++);
553 			READ_BUF(dummy);
554 			SAVEMEM(machine_name, dummy);
555 
556 			/* uid, gid */
557 			READ_BUF(8);
558 			uid = be32_to_cpup(p++);
559 			gid = be32_to_cpup(p++);
560 
561 			/* more gids */
562 			READ_BUF(4);
563 			dummy = be32_to_cpup(p++);
564 			READ_BUF(dummy * 4);
565 			if (cbs->flavor == (u32)(-1)) {
566 				kuid_t kuid = make_kuid(&init_user_ns, uid);
567 				kgid_t kgid = make_kgid(&init_user_ns, gid);
568 				if (uid_valid(kuid) && gid_valid(kgid)) {
569 					cbs->uid = kuid;
570 					cbs->gid = kgid;
571 					cbs->flavor = RPC_AUTH_UNIX;
572 				} else {
573 					dprintk("RPC_AUTH_UNIX with invalid"
574 						"uid or gid ignoring!\n");
575 				}
576 			}
577 			break;
578 		case RPC_AUTH_GSS:
579 			dprintk("RPC_AUTH_GSS callback secflavor "
580 				"not supported!\n");
581 			READ_BUF(8);
582 			/* gcbp_service */
583 			dummy = be32_to_cpup(p++);
584 			/* gcbp_handle_from_server */
585 			dummy = be32_to_cpup(p++);
586 			READ_BUF(dummy);
587 			p += XDR_QUADLEN(dummy);
588 			/* gcbp_handle_from_client */
589 			READ_BUF(4);
590 			dummy = be32_to_cpup(p++);
591 			READ_BUF(dummy);
592 			break;
593 		default:
594 			dprintk("Illegal callback secflavor\n");
595 			return nfserr_inval;
596 		}
597 	}
598 	DECODE_TAIL;
599 }
600 
601 static __be32 nfsd4_decode_backchannel_ctl(struct nfsd4_compoundargs *argp, struct nfsd4_backchannel_ctl *bc)
602 {
603 	DECODE_HEAD;
604 
605 	READ_BUF(4);
606 	bc->bc_cb_program = be32_to_cpup(p++);
607 	nfsd4_decode_cb_sec(argp, &bc->bc_cb_sec);
608 
609 	DECODE_TAIL;
610 }
611 
612 static __be32 nfsd4_decode_bind_conn_to_session(struct nfsd4_compoundargs *argp, struct nfsd4_bind_conn_to_session *bcts)
613 {
614 	DECODE_HEAD;
615 
616 	READ_BUF(NFS4_MAX_SESSIONID_LEN + 8);
617 	COPYMEM(bcts->sessionid.data, NFS4_MAX_SESSIONID_LEN);
618 	bcts->dir = be32_to_cpup(p++);
619 	/* XXX: skipping ctsa_use_conn_in_rdma_mode.  Perhaps Tom Tucker
620 	 * could help us figure out we should be using it. */
621 	DECODE_TAIL;
622 }
623 
624 static __be32
625 nfsd4_decode_close(struct nfsd4_compoundargs *argp, struct nfsd4_close *close)
626 {
627 	DECODE_HEAD;
628 
629 	READ_BUF(4);
630 	close->cl_seqid = be32_to_cpup(p++);
631 	return nfsd4_decode_stateid(argp, &close->cl_stateid);
632 
633 	DECODE_TAIL;
634 }
635 
636 
637 static __be32
638 nfsd4_decode_commit(struct nfsd4_compoundargs *argp, struct nfsd4_commit *commit)
639 {
640 	DECODE_HEAD;
641 
642 	READ_BUF(12);
643 	p = xdr_decode_hyper(p, &commit->co_offset);
644 	commit->co_count = be32_to_cpup(p++);
645 
646 	DECODE_TAIL;
647 }
648 
649 static __be32
650 nfsd4_decode_create(struct nfsd4_compoundargs *argp, struct nfsd4_create *create)
651 {
652 	DECODE_HEAD;
653 
654 	READ_BUF(4);
655 	create->cr_type = be32_to_cpup(p++);
656 	switch (create->cr_type) {
657 	case NF4LNK:
658 		READ_BUF(4);
659 		create->cr_datalen = be32_to_cpup(p++);
660 		READ_BUF(create->cr_datalen);
661 		create->cr_data = svcxdr_dupstr(argp, p, create->cr_datalen);
662 		if (!create->cr_data)
663 			return nfserr_jukebox;
664 		break;
665 	case NF4BLK:
666 	case NF4CHR:
667 		READ_BUF(8);
668 		create->cr_specdata1 = be32_to_cpup(p++);
669 		create->cr_specdata2 = be32_to_cpup(p++);
670 		break;
671 	case NF4SOCK:
672 	case NF4FIFO:
673 	case NF4DIR:
674 	default:
675 		break;
676 	}
677 
678 	READ_BUF(4);
679 	create->cr_namelen = be32_to_cpup(p++);
680 	READ_BUF(create->cr_namelen);
681 	SAVEMEM(create->cr_name, create->cr_namelen);
682 	if ((status = check_filename(create->cr_name, create->cr_namelen)))
683 		return status;
684 
685 	status = nfsd4_decode_fattr(argp, create->cr_bmval, &create->cr_iattr,
686 				    &create->cr_acl, &create->cr_label,
687 				    &create->cr_umask);
688 	if (status)
689 		goto out;
690 
691 	DECODE_TAIL;
692 }
693 
694 static inline __be32
695 nfsd4_decode_delegreturn(struct nfsd4_compoundargs *argp, struct nfsd4_delegreturn *dr)
696 {
697 	return nfsd4_decode_stateid(argp, &dr->dr_stateid);
698 }
699 
700 static inline __be32
701 nfsd4_decode_getattr(struct nfsd4_compoundargs *argp, struct nfsd4_getattr *getattr)
702 {
703 	return nfsd4_decode_bitmap(argp, getattr->ga_bmval);
704 }
705 
706 static __be32
707 nfsd4_decode_link(struct nfsd4_compoundargs *argp, struct nfsd4_link *link)
708 {
709 	DECODE_HEAD;
710 
711 	READ_BUF(4);
712 	link->li_namelen = be32_to_cpup(p++);
713 	READ_BUF(link->li_namelen);
714 	SAVEMEM(link->li_name, link->li_namelen);
715 	if ((status = check_filename(link->li_name, link->li_namelen)))
716 		return status;
717 
718 	DECODE_TAIL;
719 }
720 
721 static __be32
722 nfsd4_decode_lock(struct nfsd4_compoundargs *argp, struct nfsd4_lock *lock)
723 {
724 	DECODE_HEAD;
725 
726 	/*
727 	* type, reclaim(boolean), offset, length, new_lock_owner(boolean)
728 	*/
729 	READ_BUF(28);
730 	lock->lk_type = be32_to_cpup(p++);
731 	if ((lock->lk_type < NFS4_READ_LT) || (lock->lk_type > NFS4_WRITEW_LT))
732 		goto xdr_error;
733 	lock->lk_reclaim = be32_to_cpup(p++);
734 	p = xdr_decode_hyper(p, &lock->lk_offset);
735 	p = xdr_decode_hyper(p, &lock->lk_length);
736 	lock->lk_is_new = be32_to_cpup(p++);
737 
738 	if (lock->lk_is_new) {
739 		READ_BUF(4);
740 		lock->lk_new_open_seqid = be32_to_cpup(p++);
741 		status = nfsd4_decode_stateid(argp, &lock->lk_new_open_stateid);
742 		if (status)
743 			return status;
744 		READ_BUF(8 + sizeof(clientid_t));
745 		lock->lk_new_lock_seqid = be32_to_cpup(p++);
746 		COPYMEM(&lock->lk_new_clientid, sizeof(clientid_t));
747 		lock->lk_new_owner.len = be32_to_cpup(p++);
748 		READ_BUF(lock->lk_new_owner.len);
749 		READMEM(lock->lk_new_owner.data, lock->lk_new_owner.len);
750 	} else {
751 		status = nfsd4_decode_stateid(argp, &lock->lk_old_lock_stateid);
752 		if (status)
753 			return status;
754 		READ_BUF(4);
755 		lock->lk_old_lock_seqid = be32_to_cpup(p++);
756 	}
757 
758 	DECODE_TAIL;
759 }
760 
761 static __be32
762 nfsd4_decode_lockt(struct nfsd4_compoundargs *argp, struct nfsd4_lockt *lockt)
763 {
764 	DECODE_HEAD;
765 
766 	READ_BUF(32);
767 	lockt->lt_type = be32_to_cpup(p++);
768 	if((lockt->lt_type < NFS4_READ_LT) || (lockt->lt_type > NFS4_WRITEW_LT))
769 		goto xdr_error;
770 	p = xdr_decode_hyper(p, &lockt->lt_offset);
771 	p = xdr_decode_hyper(p, &lockt->lt_length);
772 	COPYMEM(&lockt->lt_clientid, 8);
773 	lockt->lt_owner.len = be32_to_cpup(p++);
774 	READ_BUF(lockt->lt_owner.len);
775 	READMEM(lockt->lt_owner.data, lockt->lt_owner.len);
776 
777 	DECODE_TAIL;
778 }
779 
780 static __be32
781 nfsd4_decode_locku(struct nfsd4_compoundargs *argp, struct nfsd4_locku *locku)
782 {
783 	DECODE_HEAD;
784 
785 	READ_BUF(8);
786 	locku->lu_type = be32_to_cpup(p++);
787 	if ((locku->lu_type < NFS4_READ_LT) || (locku->lu_type > NFS4_WRITEW_LT))
788 		goto xdr_error;
789 	locku->lu_seqid = be32_to_cpup(p++);
790 	status = nfsd4_decode_stateid(argp, &locku->lu_stateid);
791 	if (status)
792 		return status;
793 	READ_BUF(16);
794 	p = xdr_decode_hyper(p, &locku->lu_offset);
795 	p = xdr_decode_hyper(p, &locku->lu_length);
796 
797 	DECODE_TAIL;
798 }
799 
800 static __be32
801 nfsd4_decode_lookup(struct nfsd4_compoundargs *argp, struct nfsd4_lookup *lookup)
802 {
803 	DECODE_HEAD;
804 
805 	READ_BUF(4);
806 	lookup->lo_len = be32_to_cpup(p++);
807 	READ_BUF(lookup->lo_len);
808 	SAVEMEM(lookup->lo_name, lookup->lo_len);
809 	if ((status = check_filename(lookup->lo_name, lookup->lo_len)))
810 		return status;
811 
812 	DECODE_TAIL;
813 }
814 
815 static __be32 nfsd4_decode_share_access(struct nfsd4_compoundargs *argp, u32 *share_access, u32 *deleg_want, u32 *deleg_when)
816 {
817 	__be32 *p;
818 	u32 w;
819 
820 	READ_BUF(4);
821 	w = be32_to_cpup(p++);
822 	*share_access = w & NFS4_SHARE_ACCESS_MASK;
823 	*deleg_want = w & NFS4_SHARE_WANT_MASK;
824 	if (deleg_when)
825 		*deleg_when = w & NFS4_SHARE_WHEN_MASK;
826 
827 	switch (w & NFS4_SHARE_ACCESS_MASK) {
828 	case NFS4_SHARE_ACCESS_READ:
829 	case NFS4_SHARE_ACCESS_WRITE:
830 	case NFS4_SHARE_ACCESS_BOTH:
831 		break;
832 	default:
833 		return nfserr_bad_xdr;
834 	}
835 	w &= ~NFS4_SHARE_ACCESS_MASK;
836 	if (!w)
837 		return nfs_ok;
838 	if (!argp->minorversion)
839 		return nfserr_bad_xdr;
840 	switch (w & NFS4_SHARE_WANT_MASK) {
841 	case NFS4_SHARE_WANT_NO_PREFERENCE:
842 	case NFS4_SHARE_WANT_READ_DELEG:
843 	case NFS4_SHARE_WANT_WRITE_DELEG:
844 	case NFS4_SHARE_WANT_ANY_DELEG:
845 	case NFS4_SHARE_WANT_NO_DELEG:
846 	case NFS4_SHARE_WANT_CANCEL:
847 		break;
848 	default:
849 		return nfserr_bad_xdr;
850 	}
851 	w &= ~NFS4_SHARE_WANT_MASK;
852 	if (!w)
853 		return nfs_ok;
854 
855 	if (!deleg_when)	/* open_downgrade */
856 		return nfserr_inval;
857 	switch (w) {
858 	case NFS4_SHARE_SIGNAL_DELEG_WHEN_RESRC_AVAIL:
859 	case NFS4_SHARE_PUSH_DELEG_WHEN_UNCONTENDED:
860 	case (NFS4_SHARE_SIGNAL_DELEG_WHEN_RESRC_AVAIL |
861 	      NFS4_SHARE_PUSH_DELEG_WHEN_UNCONTENDED):
862 		return nfs_ok;
863 	}
864 xdr_error:
865 	return nfserr_bad_xdr;
866 }
867 
868 static __be32 nfsd4_decode_share_deny(struct nfsd4_compoundargs *argp, u32 *x)
869 {
870 	__be32 *p;
871 
872 	READ_BUF(4);
873 	*x = be32_to_cpup(p++);
874 	/* Note: unlinke access bits, deny bits may be zero. */
875 	if (*x & ~NFS4_SHARE_DENY_BOTH)
876 		return nfserr_bad_xdr;
877 	return nfs_ok;
878 xdr_error:
879 	return nfserr_bad_xdr;
880 }
881 
882 static __be32 nfsd4_decode_opaque(struct nfsd4_compoundargs *argp, struct xdr_netobj *o)
883 {
884 	__be32 *p;
885 
886 	READ_BUF(4);
887 	o->len = be32_to_cpup(p++);
888 
889 	if (o->len == 0 || o->len > NFS4_OPAQUE_LIMIT)
890 		return nfserr_bad_xdr;
891 
892 	READ_BUF(o->len);
893 	SAVEMEM(o->data, o->len);
894 	return nfs_ok;
895 xdr_error:
896 	return nfserr_bad_xdr;
897 }
898 
899 static __be32
900 nfsd4_decode_open(struct nfsd4_compoundargs *argp, struct nfsd4_open *open)
901 {
902 	DECODE_HEAD;
903 	u32 dummy;
904 
905 	memset(open->op_bmval, 0, sizeof(open->op_bmval));
906 	open->op_iattr.ia_valid = 0;
907 	open->op_openowner = NULL;
908 
909 	open->op_xdr_error = 0;
910 	/* seqid, share_access, share_deny, clientid, ownerlen */
911 	READ_BUF(4);
912 	open->op_seqid = be32_to_cpup(p++);
913 	/* decode, yet ignore deleg_when until supported */
914 	status = nfsd4_decode_share_access(argp, &open->op_share_access,
915 					   &open->op_deleg_want, &dummy);
916 	if (status)
917 		goto xdr_error;
918 	status = nfsd4_decode_share_deny(argp, &open->op_share_deny);
919 	if (status)
920 		goto xdr_error;
921 	READ_BUF(sizeof(clientid_t));
922 	COPYMEM(&open->op_clientid, sizeof(clientid_t));
923 	status = nfsd4_decode_opaque(argp, &open->op_owner);
924 	if (status)
925 		goto xdr_error;
926 	READ_BUF(4);
927 	open->op_create = be32_to_cpup(p++);
928 	switch (open->op_create) {
929 	case NFS4_OPEN_NOCREATE:
930 		break;
931 	case NFS4_OPEN_CREATE:
932 		READ_BUF(4);
933 		open->op_createmode = be32_to_cpup(p++);
934 		switch (open->op_createmode) {
935 		case NFS4_CREATE_UNCHECKED:
936 		case NFS4_CREATE_GUARDED:
937 			status = nfsd4_decode_fattr(argp, open->op_bmval,
938 				&open->op_iattr, &open->op_acl, &open->op_label,
939 				&open->op_umask);
940 			if (status)
941 				goto out;
942 			break;
943 		case NFS4_CREATE_EXCLUSIVE:
944 			READ_BUF(NFS4_VERIFIER_SIZE);
945 			COPYMEM(open->op_verf.data, NFS4_VERIFIER_SIZE);
946 			break;
947 		case NFS4_CREATE_EXCLUSIVE4_1:
948 			if (argp->minorversion < 1)
949 				goto xdr_error;
950 			READ_BUF(NFS4_VERIFIER_SIZE);
951 			COPYMEM(open->op_verf.data, NFS4_VERIFIER_SIZE);
952 			status = nfsd4_decode_fattr(argp, open->op_bmval,
953 				&open->op_iattr, &open->op_acl, &open->op_label,
954 				&open->op_umask);
955 			if (status)
956 				goto out;
957 			break;
958 		default:
959 			goto xdr_error;
960 		}
961 		break;
962 	default:
963 		goto xdr_error;
964 	}
965 
966 	/* open_claim */
967 	READ_BUF(4);
968 	open->op_claim_type = be32_to_cpup(p++);
969 	switch (open->op_claim_type) {
970 	case NFS4_OPEN_CLAIM_NULL:
971 	case NFS4_OPEN_CLAIM_DELEGATE_PREV:
972 		READ_BUF(4);
973 		open->op_fname.len = be32_to_cpup(p++);
974 		READ_BUF(open->op_fname.len);
975 		SAVEMEM(open->op_fname.data, open->op_fname.len);
976 		if ((status = check_filename(open->op_fname.data, open->op_fname.len)))
977 			return status;
978 		break;
979 	case NFS4_OPEN_CLAIM_PREVIOUS:
980 		READ_BUF(4);
981 		open->op_delegate_type = be32_to_cpup(p++);
982 		break;
983 	case NFS4_OPEN_CLAIM_DELEGATE_CUR:
984 		status = nfsd4_decode_stateid(argp, &open->op_delegate_stateid);
985 		if (status)
986 			return status;
987 		READ_BUF(4);
988 		open->op_fname.len = be32_to_cpup(p++);
989 		READ_BUF(open->op_fname.len);
990 		SAVEMEM(open->op_fname.data, open->op_fname.len);
991 		if ((status = check_filename(open->op_fname.data, open->op_fname.len)))
992 			return status;
993 		break;
994 	case NFS4_OPEN_CLAIM_FH:
995 	case NFS4_OPEN_CLAIM_DELEG_PREV_FH:
996 		if (argp->minorversion < 1)
997 			goto xdr_error;
998 		/* void */
999 		break;
1000 	case NFS4_OPEN_CLAIM_DELEG_CUR_FH:
1001 		if (argp->minorversion < 1)
1002 			goto xdr_error;
1003 		status = nfsd4_decode_stateid(argp, &open->op_delegate_stateid);
1004 		if (status)
1005 			return status;
1006 		break;
1007 	default:
1008 		goto xdr_error;
1009 	}
1010 
1011 	DECODE_TAIL;
1012 }
1013 
1014 static __be32
1015 nfsd4_decode_open_confirm(struct nfsd4_compoundargs *argp, struct nfsd4_open_confirm *open_conf)
1016 {
1017 	DECODE_HEAD;
1018 
1019 	if (argp->minorversion >= 1)
1020 		return nfserr_notsupp;
1021 
1022 	status = nfsd4_decode_stateid(argp, &open_conf->oc_req_stateid);
1023 	if (status)
1024 		return status;
1025 	READ_BUF(4);
1026 	open_conf->oc_seqid = be32_to_cpup(p++);
1027 
1028 	DECODE_TAIL;
1029 }
1030 
1031 static __be32
1032 nfsd4_decode_open_downgrade(struct nfsd4_compoundargs *argp, struct nfsd4_open_downgrade *open_down)
1033 {
1034 	DECODE_HEAD;
1035 
1036 	status = nfsd4_decode_stateid(argp, &open_down->od_stateid);
1037 	if (status)
1038 		return status;
1039 	READ_BUF(4);
1040 	open_down->od_seqid = be32_to_cpup(p++);
1041 	status = nfsd4_decode_share_access(argp, &open_down->od_share_access,
1042 					   &open_down->od_deleg_want, NULL);
1043 	if (status)
1044 		return status;
1045 	status = nfsd4_decode_share_deny(argp, &open_down->od_share_deny);
1046 	if (status)
1047 		return status;
1048 	DECODE_TAIL;
1049 }
1050 
1051 static __be32
1052 nfsd4_decode_putfh(struct nfsd4_compoundargs *argp, struct nfsd4_putfh *putfh)
1053 {
1054 	DECODE_HEAD;
1055 
1056 	READ_BUF(4);
1057 	putfh->pf_fhlen = be32_to_cpup(p++);
1058 	if (putfh->pf_fhlen > NFS4_FHSIZE)
1059 		goto xdr_error;
1060 	READ_BUF(putfh->pf_fhlen);
1061 	SAVEMEM(putfh->pf_fhval, putfh->pf_fhlen);
1062 
1063 	DECODE_TAIL;
1064 }
1065 
1066 static __be32
1067 nfsd4_decode_putpubfh(struct nfsd4_compoundargs *argp, void *p)
1068 {
1069 	if (argp->minorversion == 0)
1070 		return nfs_ok;
1071 	return nfserr_notsupp;
1072 }
1073 
1074 static __be32
1075 nfsd4_decode_read(struct nfsd4_compoundargs *argp, struct nfsd4_read *read)
1076 {
1077 	DECODE_HEAD;
1078 
1079 	status = nfsd4_decode_stateid(argp, &read->rd_stateid);
1080 	if (status)
1081 		return status;
1082 	READ_BUF(12);
1083 	p = xdr_decode_hyper(p, &read->rd_offset);
1084 	read->rd_length = be32_to_cpup(p++);
1085 
1086 	DECODE_TAIL;
1087 }
1088 
1089 static __be32
1090 nfsd4_decode_readdir(struct nfsd4_compoundargs *argp, struct nfsd4_readdir *readdir)
1091 {
1092 	DECODE_HEAD;
1093 
1094 	READ_BUF(24);
1095 	p = xdr_decode_hyper(p, &readdir->rd_cookie);
1096 	COPYMEM(readdir->rd_verf.data, sizeof(readdir->rd_verf.data));
1097 	readdir->rd_dircount = be32_to_cpup(p++);
1098 	readdir->rd_maxcount = be32_to_cpup(p++);
1099 	if ((status = nfsd4_decode_bitmap(argp, readdir->rd_bmval)))
1100 		goto out;
1101 
1102 	DECODE_TAIL;
1103 }
1104 
1105 static __be32
1106 nfsd4_decode_remove(struct nfsd4_compoundargs *argp, struct nfsd4_remove *remove)
1107 {
1108 	DECODE_HEAD;
1109 
1110 	READ_BUF(4);
1111 	remove->rm_namelen = be32_to_cpup(p++);
1112 	READ_BUF(remove->rm_namelen);
1113 	SAVEMEM(remove->rm_name, remove->rm_namelen);
1114 	if ((status = check_filename(remove->rm_name, remove->rm_namelen)))
1115 		return status;
1116 
1117 	DECODE_TAIL;
1118 }
1119 
1120 static __be32
1121 nfsd4_decode_rename(struct nfsd4_compoundargs *argp, struct nfsd4_rename *rename)
1122 {
1123 	DECODE_HEAD;
1124 
1125 	READ_BUF(4);
1126 	rename->rn_snamelen = be32_to_cpup(p++);
1127 	READ_BUF(rename->rn_snamelen);
1128 	SAVEMEM(rename->rn_sname, rename->rn_snamelen);
1129 	READ_BUF(4);
1130 	rename->rn_tnamelen = be32_to_cpup(p++);
1131 	READ_BUF(rename->rn_tnamelen);
1132 	SAVEMEM(rename->rn_tname, rename->rn_tnamelen);
1133 	if ((status = check_filename(rename->rn_sname, rename->rn_snamelen)))
1134 		return status;
1135 	if ((status = check_filename(rename->rn_tname, rename->rn_tnamelen)))
1136 		return status;
1137 
1138 	DECODE_TAIL;
1139 }
1140 
1141 static __be32
1142 nfsd4_decode_renew(struct nfsd4_compoundargs *argp, clientid_t *clientid)
1143 {
1144 	DECODE_HEAD;
1145 
1146 	if (argp->minorversion >= 1)
1147 		return nfserr_notsupp;
1148 
1149 	READ_BUF(sizeof(clientid_t));
1150 	COPYMEM(clientid, sizeof(clientid_t));
1151 
1152 	DECODE_TAIL;
1153 }
1154 
1155 static __be32
1156 nfsd4_decode_secinfo(struct nfsd4_compoundargs *argp,
1157 		     struct nfsd4_secinfo *secinfo)
1158 {
1159 	DECODE_HEAD;
1160 
1161 	READ_BUF(4);
1162 	secinfo->si_namelen = be32_to_cpup(p++);
1163 	READ_BUF(secinfo->si_namelen);
1164 	SAVEMEM(secinfo->si_name, secinfo->si_namelen);
1165 	status = check_filename(secinfo->si_name, secinfo->si_namelen);
1166 	if (status)
1167 		return status;
1168 	DECODE_TAIL;
1169 }
1170 
1171 static __be32
1172 nfsd4_decode_secinfo_no_name(struct nfsd4_compoundargs *argp,
1173 		     struct nfsd4_secinfo_no_name *sin)
1174 {
1175 	DECODE_HEAD;
1176 
1177 	READ_BUF(4);
1178 	sin->sin_style = be32_to_cpup(p++);
1179 	DECODE_TAIL;
1180 }
1181 
1182 static __be32
1183 nfsd4_decode_setattr(struct nfsd4_compoundargs *argp, struct nfsd4_setattr *setattr)
1184 {
1185 	__be32 status;
1186 
1187 	status = nfsd4_decode_stateid(argp, &setattr->sa_stateid);
1188 	if (status)
1189 		return status;
1190 	return nfsd4_decode_fattr(argp, setattr->sa_bmval, &setattr->sa_iattr,
1191 				  &setattr->sa_acl, &setattr->sa_label, NULL);
1192 }
1193 
1194 static __be32
1195 nfsd4_decode_setclientid(struct nfsd4_compoundargs *argp, struct nfsd4_setclientid *setclientid)
1196 {
1197 	DECODE_HEAD;
1198 
1199 	if (argp->minorversion >= 1)
1200 		return nfserr_notsupp;
1201 
1202 	READ_BUF(NFS4_VERIFIER_SIZE);
1203 	COPYMEM(setclientid->se_verf.data, NFS4_VERIFIER_SIZE);
1204 
1205 	status = nfsd4_decode_opaque(argp, &setclientid->se_name);
1206 	if (status)
1207 		return nfserr_bad_xdr;
1208 	READ_BUF(8);
1209 	setclientid->se_callback_prog = be32_to_cpup(p++);
1210 	setclientid->se_callback_netid_len = be32_to_cpup(p++);
1211 	READ_BUF(setclientid->se_callback_netid_len);
1212 	SAVEMEM(setclientid->se_callback_netid_val, setclientid->se_callback_netid_len);
1213 	READ_BUF(4);
1214 	setclientid->se_callback_addr_len = be32_to_cpup(p++);
1215 
1216 	READ_BUF(setclientid->se_callback_addr_len);
1217 	SAVEMEM(setclientid->se_callback_addr_val, setclientid->se_callback_addr_len);
1218 	READ_BUF(4);
1219 	setclientid->se_callback_ident = be32_to_cpup(p++);
1220 
1221 	DECODE_TAIL;
1222 }
1223 
1224 static __be32
1225 nfsd4_decode_setclientid_confirm(struct nfsd4_compoundargs *argp, struct nfsd4_setclientid_confirm *scd_c)
1226 {
1227 	DECODE_HEAD;
1228 
1229 	if (argp->minorversion >= 1)
1230 		return nfserr_notsupp;
1231 
1232 	READ_BUF(8 + NFS4_VERIFIER_SIZE);
1233 	COPYMEM(&scd_c->sc_clientid, 8);
1234 	COPYMEM(&scd_c->sc_confirm, NFS4_VERIFIER_SIZE);
1235 
1236 	DECODE_TAIL;
1237 }
1238 
1239 /* Also used for NVERIFY */
1240 static __be32
1241 nfsd4_decode_verify(struct nfsd4_compoundargs *argp, struct nfsd4_verify *verify)
1242 {
1243 	DECODE_HEAD;
1244 
1245 	if ((status = nfsd4_decode_bitmap(argp, verify->ve_bmval)))
1246 		goto out;
1247 
1248 	/* For convenience's sake, we compare raw xdr'd attributes in
1249 	 * nfsd4_proc_verify */
1250 
1251 	READ_BUF(4);
1252 	verify->ve_attrlen = be32_to_cpup(p++);
1253 	READ_BUF(verify->ve_attrlen);
1254 	SAVEMEM(verify->ve_attrval, verify->ve_attrlen);
1255 
1256 	DECODE_TAIL;
1257 }
1258 
1259 static __be32
1260 nfsd4_decode_write(struct nfsd4_compoundargs *argp, struct nfsd4_write *write)
1261 {
1262 	int avail;
1263 	int len;
1264 	DECODE_HEAD;
1265 
1266 	status = nfsd4_decode_stateid(argp, &write->wr_stateid);
1267 	if (status)
1268 		return status;
1269 	READ_BUF(16);
1270 	p = xdr_decode_hyper(p, &write->wr_offset);
1271 	write->wr_stable_how = be32_to_cpup(p++);
1272 	if (write->wr_stable_how > NFS_FILE_SYNC)
1273 		goto xdr_error;
1274 	write->wr_buflen = be32_to_cpup(p++);
1275 
1276 	/* Sorry .. no magic macros for this.. *
1277 	 * READ_BUF(write->wr_buflen);
1278 	 * SAVEMEM(write->wr_buf, write->wr_buflen);
1279 	 */
1280 	avail = (char*)argp->end - (char*)argp->p;
1281 	if (avail + argp->pagelen < write->wr_buflen) {
1282 		dprintk("NFSD: xdr error (%s:%d)\n",
1283 				__FILE__, __LINE__);
1284 		goto xdr_error;
1285 	}
1286 	write->wr_head.iov_base = p;
1287 	write->wr_head.iov_len = avail;
1288 	write->wr_pagelist = argp->pagelist;
1289 
1290 	len = XDR_QUADLEN(write->wr_buflen) << 2;
1291 	if (len >= avail) {
1292 		int pages;
1293 
1294 		len -= avail;
1295 
1296 		pages = len >> PAGE_SHIFT;
1297 		argp->pagelist += pages;
1298 		argp->pagelen -= pages * PAGE_SIZE;
1299 		len -= pages * PAGE_SIZE;
1300 
1301 		next_decode_page(argp);
1302 	}
1303 	argp->p += XDR_QUADLEN(len);
1304 
1305 	DECODE_TAIL;
1306 }
1307 
1308 static __be32
1309 nfsd4_decode_release_lockowner(struct nfsd4_compoundargs *argp, struct nfsd4_release_lockowner *rlockowner)
1310 {
1311 	DECODE_HEAD;
1312 
1313 	if (argp->minorversion >= 1)
1314 		return nfserr_notsupp;
1315 
1316 	READ_BUF(12);
1317 	COPYMEM(&rlockowner->rl_clientid, sizeof(clientid_t));
1318 	rlockowner->rl_owner.len = be32_to_cpup(p++);
1319 	READ_BUF(rlockowner->rl_owner.len);
1320 	READMEM(rlockowner->rl_owner.data, rlockowner->rl_owner.len);
1321 
1322 	if (argp->minorversion && !zero_clientid(&rlockowner->rl_clientid))
1323 		return nfserr_inval;
1324 	DECODE_TAIL;
1325 }
1326 
1327 static __be32
1328 nfsd4_decode_exchange_id(struct nfsd4_compoundargs *argp,
1329 			 struct nfsd4_exchange_id *exid)
1330 {
1331 	int dummy, tmp;
1332 	DECODE_HEAD;
1333 
1334 	READ_BUF(NFS4_VERIFIER_SIZE);
1335 	COPYMEM(exid->verifier.data, NFS4_VERIFIER_SIZE);
1336 
1337 	status = nfsd4_decode_opaque(argp, &exid->clname);
1338 	if (status)
1339 		return nfserr_bad_xdr;
1340 
1341 	READ_BUF(4);
1342 	exid->flags = be32_to_cpup(p++);
1343 
1344 	/* Ignore state_protect4_a */
1345 	READ_BUF(4);
1346 	exid->spa_how = be32_to_cpup(p++);
1347 	switch (exid->spa_how) {
1348 	case SP4_NONE:
1349 		break;
1350 	case SP4_MACH_CRED:
1351 		/* spo_must_enforce */
1352 		status = nfsd4_decode_bitmap(argp,
1353 					exid->spo_must_enforce);
1354 		if (status)
1355 			goto out;
1356 		/* spo_must_allow */
1357 		status = nfsd4_decode_bitmap(argp, exid->spo_must_allow);
1358 		if (status)
1359 			goto out;
1360 		break;
1361 	case SP4_SSV:
1362 		/* ssp_ops */
1363 		READ_BUF(4);
1364 		dummy = be32_to_cpup(p++);
1365 		READ_BUF(dummy * 4);
1366 		p += dummy;
1367 
1368 		READ_BUF(4);
1369 		dummy = be32_to_cpup(p++);
1370 		READ_BUF(dummy * 4);
1371 		p += dummy;
1372 
1373 		/* ssp_hash_algs<> */
1374 		READ_BUF(4);
1375 		tmp = be32_to_cpup(p++);
1376 		while (tmp--) {
1377 			READ_BUF(4);
1378 			dummy = be32_to_cpup(p++);
1379 			READ_BUF(dummy);
1380 			p += XDR_QUADLEN(dummy);
1381 		}
1382 
1383 		/* ssp_encr_algs<> */
1384 		READ_BUF(4);
1385 		tmp = be32_to_cpup(p++);
1386 		while (tmp--) {
1387 			READ_BUF(4);
1388 			dummy = be32_to_cpup(p++);
1389 			READ_BUF(dummy);
1390 			p += XDR_QUADLEN(dummy);
1391 		}
1392 
1393 		/* ssp_window and ssp_num_gss_handles */
1394 		READ_BUF(8);
1395 		dummy = be32_to_cpup(p++);
1396 		dummy = be32_to_cpup(p++);
1397 		break;
1398 	default:
1399 		goto xdr_error;
1400 	}
1401 
1402 	/* Ignore Implementation ID */
1403 	READ_BUF(4);    /* nfs_impl_id4 array length */
1404 	dummy = be32_to_cpup(p++);
1405 
1406 	if (dummy > 1)
1407 		goto xdr_error;
1408 
1409 	if (dummy == 1) {
1410 		/* nii_domain */
1411 		READ_BUF(4);
1412 		dummy = be32_to_cpup(p++);
1413 		READ_BUF(dummy);
1414 		p += XDR_QUADLEN(dummy);
1415 
1416 		/* nii_name */
1417 		READ_BUF(4);
1418 		dummy = be32_to_cpup(p++);
1419 		READ_BUF(dummy);
1420 		p += XDR_QUADLEN(dummy);
1421 
1422 		/* nii_date */
1423 		READ_BUF(12);
1424 		p += 3;
1425 	}
1426 	DECODE_TAIL;
1427 }
1428 
1429 static __be32
1430 nfsd4_decode_create_session(struct nfsd4_compoundargs *argp,
1431 			    struct nfsd4_create_session *sess)
1432 {
1433 	DECODE_HEAD;
1434 	u32 dummy;
1435 
1436 	READ_BUF(16);
1437 	COPYMEM(&sess->clientid, 8);
1438 	sess->seqid = be32_to_cpup(p++);
1439 	sess->flags = be32_to_cpup(p++);
1440 
1441 	/* Fore channel attrs */
1442 	READ_BUF(28);
1443 	dummy = be32_to_cpup(p++); /* headerpadsz is always 0 */
1444 	sess->fore_channel.maxreq_sz = be32_to_cpup(p++);
1445 	sess->fore_channel.maxresp_sz = be32_to_cpup(p++);
1446 	sess->fore_channel.maxresp_cached = be32_to_cpup(p++);
1447 	sess->fore_channel.maxops = be32_to_cpup(p++);
1448 	sess->fore_channel.maxreqs = be32_to_cpup(p++);
1449 	sess->fore_channel.nr_rdma_attrs = be32_to_cpup(p++);
1450 	if (sess->fore_channel.nr_rdma_attrs == 1) {
1451 		READ_BUF(4);
1452 		sess->fore_channel.rdma_attrs = be32_to_cpup(p++);
1453 	} else if (sess->fore_channel.nr_rdma_attrs > 1) {
1454 		dprintk("Too many fore channel attr bitmaps!\n");
1455 		goto xdr_error;
1456 	}
1457 
1458 	/* Back channel attrs */
1459 	READ_BUF(28);
1460 	dummy = be32_to_cpup(p++); /* headerpadsz is always 0 */
1461 	sess->back_channel.maxreq_sz = be32_to_cpup(p++);
1462 	sess->back_channel.maxresp_sz = be32_to_cpup(p++);
1463 	sess->back_channel.maxresp_cached = be32_to_cpup(p++);
1464 	sess->back_channel.maxops = be32_to_cpup(p++);
1465 	sess->back_channel.maxreqs = be32_to_cpup(p++);
1466 	sess->back_channel.nr_rdma_attrs = be32_to_cpup(p++);
1467 	if (sess->back_channel.nr_rdma_attrs == 1) {
1468 		READ_BUF(4);
1469 		sess->back_channel.rdma_attrs = be32_to_cpup(p++);
1470 	} else if (sess->back_channel.nr_rdma_attrs > 1) {
1471 		dprintk("Too many back channel attr bitmaps!\n");
1472 		goto xdr_error;
1473 	}
1474 
1475 	READ_BUF(4);
1476 	sess->callback_prog = be32_to_cpup(p++);
1477 	nfsd4_decode_cb_sec(argp, &sess->cb_sec);
1478 	DECODE_TAIL;
1479 }
1480 
1481 static __be32
1482 nfsd4_decode_destroy_session(struct nfsd4_compoundargs *argp,
1483 			     struct nfsd4_destroy_session *destroy_session)
1484 {
1485 	DECODE_HEAD;
1486 	READ_BUF(NFS4_MAX_SESSIONID_LEN);
1487 	COPYMEM(destroy_session->sessionid.data, NFS4_MAX_SESSIONID_LEN);
1488 
1489 	DECODE_TAIL;
1490 }
1491 
1492 static __be32
1493 nfsd4_decode_free_stateid(struct nfsd4_compoundargs *argp,
1494 			  struct nfsd4_free_stateid *free_stateid)
1495 {
1496 	DECODE_HEAD;
1497 
1498 	READ_BUF(sizeof(stateid_t));
1499 	free_stateid->fr_stateid.si_generation = be32_to_cpup(p++);
1500 	COPYMEM(&free_stateid->fr_stateid.si_opaque, sizeof(stateid_opaque_t));
1501 
1502 	DECODE_TAIL;
1503 }
1504 
1505 static __be32
1506 nfsd4_decode_sequence(struct nfsd4_compoundargs *argp,
1507 		      struct nfsd4_sequence *seq)
1508 {
1509 	DECODE_HEAD;
1510 
1511 	READ_BUF(NFS4_MAX_SESSIONID_LEN + 16);
1512 	COPYMEM(seq->sessionid.data, NFS4_MAX_SESSIONID_LEN);
1513 	seq->seqid = be32_to_cpup(p++);
1514 	seq->slotid = be32_to_cpup(p++);
1515 	seq->maxslots = be32_to_cpup(p++);
1516 	seq->cachethis = be32_to_cpup(p++);
1517 
1518 	DECODE_TAIL;
1519 }
1520 
1521 static __be32
1522 nfsd4_decode_test_stateid(struct nfsd4_compoundargs *argp, struct nfsd4_test_stateid *test_stateid)
1523 {
1524 	int i;
1525 	__be32 *p, status;
1526 	struct nfsd4_test_stateid_id *stateid;
1527 
1528 	READ_BUF(4);
1529 	test_stateid->ts_num_ids = ntohl(*p++);
1530 
1531 	INIT_LIST_HEAD(&test_stateid->ts_stateid_list);
1532 
1533 	for (i = 0; i < test_stateid->ts_num_ids; i++) {
1534 		stateid = svcxdr_tmpalloc(argp, sizeof(*stateid));
1535 		if (!stateid) {
1536 			status = nfserrno(-ENOMEM);
1537 			goto out;
1538 		}
1539 
1540 		INIT_LIST_HEAD(&stateid->ts_id_list);
1541 		list_add_tail(&stateid->ts_id_list, &test_stateid->ts_stateid_list);
1542 
1543 		status = nfsd4_decode_stateid(argp, &stateid->ts_id_stateid);
1544 		if (status)
1545 			goto out;
1546 	}
1547 
1548 	status = 0;
1549 out:
1550 	return status;
1551 xdr_error:
1552 	dprintk("NFSD: xdr error (%s:%d)\n", __FILE__, __LINE__);
1553 	status = nfserr_bad_xdr;
1554 	goto out;
1555 }
1556 
1557 static __be32 nfsd4_decode_destroy_clientid(struct nfsd4_compoundargs *argp, struct nfsd4_destroy_clientid *dc)
1558 {
1559 	DECODE_HEAD;
1560 
1561 	READ_BUF(8);
1562 	COPYMEM(&dc->clientid, 8);
1563 
1564 	DECODE_TAIL;
1565 }
1566 
1567 static __be32 nfsd4_decode_reclaim_complete(struct nfsd4_compoundargs *argp, struct nfsd4_reclaim_complete *rc)
1568 {
1569 	DECODE_HEAD;
1570 
1571 	READ_BUF(4);
1572 	rc->rca_one_fs = be32_to_cpup(p++);
1573 
1574 	DECODE_TAIL;
1575 }
1576 
1577 #ifdef CONFIG_NFSD_PNFS
1578 static __be32
1579 nfsd4_decode_getdeviceinfo(struct nfsd4_compoundargs *argp,
1580 		struct nfsd4_getdeviceinfo *gdev)
1581 {
1582 	DECODE_HEAD;
1583 	u32 num, i;
1584 
1585 	READ_BUF(sizeof(struct nfsd4_deviceid) + 3 * 4);
1586 	COPYMEM(&gdev->gd_devid, sizeof(struct nfsd4_deviceid));
1587 	gdev->gd_layout_type = be32_to_cpup(p++);
1588 	gdev->gd_maxcount = be32_to_cpup(p++);
1589 	num = be32_to_cpup(p++);
1590 	if (num) {
1591 		if (num > 1000)
1592 			goto xdr_error;
1593 		READ_BUF(4 * num);
1594 		gdev->gd_notify_types = be32_to_cpup(p++);
1595 		for (i = 1; i < num; i++) {
1596 			if (be32_to_cpup(p++)) {
1597 				status = nfserr_inval;
1598 				goto out;
1599 			}
1600 		}
1601 	}
1602 	DECODE_TAIL;
1603 }
1604 
1605 static __be32
1606 nfsd4_decode_layoutget(struct nfsd4_compoundargs *argp,
1607 		struct nfsd4_layoutget *lgp)
1608 {
1609 	DECODE_HEAD;
1610 
1611 	READ_BUF(36);
1612 	lgp->lg_signal = be32_to_cpup(p++);
1613 	lgp->lg_layout_type = be32_to_cpup(p++);
1614 	lgp->lg_seg.iomode = be32_to_cpup(p++);
1615 	p = xdr_decode_hyper(p, &lgp->lg_seg.offset);
1616 	p = xdr_decode_hyper(p, &lgp->lg_seg.length);
1617 	p = xdr_decode_hyper(p, &lgp->lg_minlength);
1618 
1619 	status = nfsd4_decode_stateid(argp, &lgp->lg_sid);
1620 	if (status)
1621 		return status;
1622 
1623 	READ_BUF(4);
1624 	lgp->lg_maxcount = be32_to_cpup(p++);
1625 
1626 	DECODE_TAIL;
1627 }
1628 
1629 static __be32
1630 nfsd4_decode_layoutcommit(struct nfsd4_compoundargs *argp,
1631 		struct nfsd4_layoutcommit *lcp)
1632 {
1633 	DECODE_HEAD;
1634 	u32 timechange;
1635 
1636 	READ_BUF(20);
1637 	p = xdr_decode_hyper(p, &lcp->lc_seg.offset);
1638 	p = xdr_decode_hyper(p, &lcp->lc_seg.length);
1639 	lcp->lc_reclaim = be32_to_cpup(p++);
1640 
1641 	status = nfsd4_decode_stateid(argp, &lcp->lc_sid);
1642 	if (status)
1643 		return status;
1644 
1645 	READ_BUF(4);
1646 	lcp->lc_newoffset = be32_to_cpup(p++);
1647 	if (lcp->lc_newoffset) {
1648 		READ_BUF(8);
1649 		p = xdr_decode_hyper(p, &lcp->lc_last_wr);
1650 	} else
1651 		lcp->lc_last_wr = 0;
1652 	READ_BUF(4);
1653 	timechange = be32_to_cpup(p++);
1654 	if (timechange) {
1655 		status = nfsd4_decode_time(argp, &lcp->lc_mtime);
1656 		if (status)
1657 			return status;
1658 	} else {
1659 		lcp->lc_mtime.tv_nsec = UTIME_NOW;
1660 	}
1661 	READ_BUF(8);
1662 	lcp->lc_layout_type = be32_to_cpup(p++);
1663 
1664 	/*
1665 	 * Save the layout update in XDR format and let the layout driver deal
1666 	 * with it later.
1667 	 */
1668 	lcp->lc_up_len = be32_to_cpup(p++);
1669 	if (lcp->lc_up_len > 0) {
1670 		READ_BUF(lcp->lc_up_len);
1671 		READMEM(lcp->lc_up_layout, lcp->lc_up_len);
1672 	}
1673 
1674 	DECODE_TAIL;
1675 }
1676 
1677 static __be32
1678 nfsd4_decode_layoutreturn(struct nfsd4_compoundargs *argp,
1679 		struct nfsd4_layoutreturn *lrp)
1680 {
1681 	DECODE_HEAD;
1682 
1683 	READ_BUF(16);
1684 	lrp->lr_reclaim = be32_to_cpup(p++);
1685 	lrp->lr_layout_type = be32_to_cpup(p++);
1686 	lrp->lr_seg.iomode = be32_to_cpup(p++);
1687 	lrp->lr_return_type = be32_to_cpup(p++);
1688 	if (lrp->lr_return_type == RETURN_FILE) {
1689 		READ_BUF(16);
1690 		p = xdr_decode_hyper(p, &lrp->lr_seg.offset);
1691 		p = xdr_decode_hyper(p, &lrp->lr_seg.length);
1692 
1693 		status = nfsd4_decode_stateid(argp, &lrp->lr_sid);
1694 		if (status)
1695 			return status;
1696 
1697 		READ_BUF(4);
1698 		lrp->lrf_body_len = be32_to_cpup(p++);
1699 		if (lrp->lrf_body_len > 0) {
1700 			READ_BUF(lrp->lrf_body_len);
1701 			READMEM(lrp->lrf_body, lrp->lrf_body_len);
1702 		}
1703 	} else {
1704 		lrp->lr_seg.offset = 0;
1705 		lrp->lr_seg.length = NFS4_MAX_UINT64;
1706 	}
1707 
1708 	DECODE_TAIL;
1709 }
1710 #endif /* CONFIG_NFSD_PNFS */
1711 
1712 static __be32
1713 nfsd4_decode_fallocate(struct nfsd4_compoundargs *argp,
1714 		       struct nfsd4_fallocate *fallocate)
1715 {
1716 	DECODE_HEAD;
1717 
1718 	status = nfsd4_decode_stateid(argp, &fallocate->falloc_stateid);
1719 	if (status)
1720 		return status;
1721 
1722 	READ_BUF(16);
1723 	p = xdr_decode_hyper(p, &fallocate->falloc_offset);
1724 	xdr_decode_hyper(p, &fallocate->falloc_length);
1725 
1726 	DECODE_TAIL;
1727 }
1728 
1729 static __be32
1730 nfsd4_decode_clone(struct nfsd4_compoundargs *argp, struct nfsd4_clone *clone)
1731 {
1732 	DECODE_HEAD;
1733 
1734 	status = nfsd4_decode_stateid(argp, &clone->cl_src_stateid);
1735 	if (status)
1736 		return status;
1737 	status = nfsd4_decode_stateid(argp, &clone->cl_dst_stateid);
1738 	if (status)
1739 		return status;
1740 
1741 	READ_BUF(8 + 8 + 8);
1742 	p = xdr_decode_hyper(p, &clone->cl_src_pos);
1743 	p = xdr_decode_hyper(p, &clone->cl_dst_pos);
1744 	p = xdr_decode_hyper(p, &clone->cl_count);
1745 	DECODE_TAIL;
1746 }
1747 
1748 static __be32
1749 nfsd4_decode_copy(struct nfsd4_compoundargs *argp, struct nfsd4_copy *copy)
1750 {
1751 	DECODE_HEAD;
1752 	unsigned int tmp;
1753 
1754 	status = nfsd4_decode_stateid(argp, &copy->cp_src_stateid);
1755 	if (status)
1756 		return status;
1757 	status = nfsd4_decode_stateid(argp, &copy->cp_dst_stateid);
1758 	if (status)
1759 		return status;
1760 
1761 	READ_BUF(8 + 8 + 8 + 4 + 4 + 4);
1762 	p = xdr_decode_hyper(p, &copy->cp_src_pos);
1763 	p = xdr_decode_hyper(p, &copy->cp_dst_pos);
1764 	p = xdr_decode_hyper(p, &copy->cp_count);
1765 	p++; /* ca_consecutive: we always do consecutive copies */
1766 	copy->cp_synchronous = be32_to_cpup(p++);
1767 	tmp = be32_to_cpup(p); /* Source server list not supported */
1768 
1769 	DECODE_TAIL;
1770 }
1771 
1772 static __be32
1773 nfsd4_decode_seek(struct nfsd4_compoundargs *argp, struct nfsd4_seek *seek)
1774 {
1775 	DECODE_HEAD;
1776 
1777 	status = nfsd4_decode_stateid(argp, &seek->seek_stateid);
1778 	if (status)
1779 		return status;
1780 
1781 	READ_BUF(8 + 4);
1782 	p = xdr_decode_hyper(p, &seek->seek_offset);
1783 	seek->seek_whence = be32_to_cpup(p);
1784 
1785 	DECODE_TAIL;
1786 }
1787 
1788 static __be32
1789 nfsd4_decode_noop(struct nfsd4_compoundargs *argp, void *p)
1790 {
1791 	return nfs_ok;
1792 }
1793 
1794 static __be32
1795 nfsd4_decode_notsupp(struct nfsd4_compoundargs *argp, void *p)
1796 {
1797 	return nfserr_notsupp;
1798 }
1799 
1800 typedef __be32(*nfsd4_dec)(struct nfsd4_compoundargs *argp, void *);
1801 
1802 static const nfsd4_dec nfsd4_dec_ops[] = {
1803 	[OP_ACCESS]		= (nfsd4_dec)nfsd4_decode_access,
1804 	[OP_CLOSE]		= (nfsd4_dec)nfsd4_decode_close,
1805 	[OP_COMMIT]		= (nfsd4_dec)nfsd4_decode_commit,
1806 	[OP_CREATE]		= (nfsd4_dec)nfsd4_decode_create,
1807 	[OP_DELEGPURGE]		= (nfsd4_dec)nfsd4_decode_notsupp,
1808 	[OP_DELEGRETURN]	= (nfsd4_dec)nfsd4_decode_delegreturn,
1809 	[OP_GETATTR]		= (nfsd4_dec)nfsd4_decode_getattr,
1810 	[OP_GETFH]		= (nfsd4_dec)nfsd4_decode_noop,
1811 	[OP_LINK]		= (nfsd4_dec)nfsd4_decode_link,
1812 	[OP_LOCK]		= (nfsd4_dec)nfsd4_decode_lock,
1813 	[OP_LOCKT]		= (nfsd4_dec)nfsd4_decode_lockt,
1814 	[OP_LOCKU]		= (nfsd4_dec)nfsd4_decode_locku,
1815 	[OP_LOOKUP]		= (nfsd4_dec)nfsd4_decode_lookup,
1816 	[OP_LOOKUPP]		= (nfsd4_dec)nfsd4_decode_noop,
1817 	[OP_NVERIFY]		= (nfsd4_dec)nfsd4_decode_verify,
1818 	[OP_OPEN]		= (nfsd4_dec)nfsd4_decode_open,
1819 	[OP_OPENATTR]		= (nfsd4_dec)nfsd4_decode_notsupp,
1820 	[OP_OPEN_CONFIRM]	= (nfsd4_dec)nfsd4_decode_open_confirm,
1821 	[OP_OPEN_DOWNGRADE]	= (nfsd4_dec)nfsd4_decode_open_downgrade,
1822 	[OP_PUTFH]		= (nfsd4_dec)nfsd4_decode_putfh,
1823 	[OP_PUTPUBFH]		= (nfsd4_dec)nfsd4_decode_putpubfh,
1824 	[OP_PUTROOTFH]		= (nfsd4_dec)nfsd4_decode_noop,
1825 	[OP_READ]		= (nfsd4_dec)nfsd4_decode_read,
1826 	[OP_READDIR]		= (nfsd4_dec)nfsd4_decode_readdir,
1827 	[OP_READLINK]		= (nfsd4_dec)nfsd4_decode_noop,
1828 	[OP_REMOVE]		= (nfsd4_dec)nfsd4_decode_remove,
1829 	[OP_RENAME]		= (nfsd4_dec)nfsd4_decode_rename,
1830 	[OP_RENEW]		= (nfsd4_dec)nfsd4_decode_renew,
1831 	[OP_RESTOREFH]		= (nfsd4_dec)nfsd4_decode_noop,
1832 	[OP_SAVEFH]		= (nfsd4_dec)nfsd4_decode_noop,
1833 	[OP_SECINFO]		= (nfsd4_dec)nfsd4_decode_secinfo,
1834 	[OP_SETATTR]		= (nfsd4_dec)nfsd4_decode_setattr,
1835 	[OP_SETCLIENTID]	= (nfsd4_dec)nfsd4_decode_setclientid,
1836 	[OP_SETCLIENTID_CONFIRM] = (nfsd4_dec)nfsd4_decode_setclientid_confirm,
1837 	[OP_VERIFY]		= (nfsd4_dec)nfsd4_decode_verify,
1838 	[OP_WRITE]		= (nfsd4_dec)nfsd4_decode_write,
1839 	[OP_RELEASE_LOCKOWNER]	= (nfsd4_dec)nfsd4_decode_release_lockowner,
1840 
1841 	/* new operations for NFSv4.1 */
1842 	[OP_BACKCHANNEL_CTL]	= (nfsd4_dec)nfsd4_decode_backchannel_ctl,
1843 	[OP_BIND_CONN_TO_SESSION]= (nfsd4_dec)nfsd4_decode_bind_conn_to_session,
1844 	[OP_EXCHANGE_ID]	= (nfsd4_dec)nfsd4_decode_exchange_id,
1845 	[OP_CREATE_SESSION]	= (nfsd4_dec)nfsd4_decode_create_session,
1846 	[OP_DESTROY_SESSION]	= (nfsd4_dec)nfsd4_decode_destroy_session,
1847 	[OP_FREE_STATEID]	= (nfsd4_dec)nfsd4_decode_free_stateid,
1848 	[OP_GET_DIR_DELEGATION]	= (nfsd4_dec)nfsd4_decode_notsupp,
1849 #ifdef CONFIG_NFSD_PNFS
1850 	[OP_GETDEVICEINFO]	= (nfsd4_dec)nfsd4_decode_getdeviceinfo,
1851 	[OP_GETDEVICELIST]	= (nfsd4_dec)nfsd4_decode_notsupp,
1852 	[OP_LAYOUTCOMMIT]	= (nfsd4_dec)nfsd4_decode_layoutcommit,
1853 	[OP_LAYOUTGET]		= (nfsd4_dec)nfsd4_decode_layoutget,
1854 	[OP_LAYOUTRETURN]	= (nfsd4_dec)nfsd4_decode_layoutreturn,
1855 #else
1856 	[OP_GETDEVICEINFO]	= (nfsd4_dec)nfsd4_decode_notsupp,
1857 	[OP_GETDEVICELIST]	= (nfsd4_dec)nfsd4_decode_notsupp,
1858 	[OP_LAYOUTCOMMIT]	= (nfsd4_dec)nfsd4_decode_notsupp,
1859 	[OP_LAYOUTGET]		= (nfsd4_dec)nfsd4_decode_notsupp,
1860 	[OP_LAYOUTRETURN]	= (nfsd4_dec)nfsd4_decode_notsupp,
1861 #endif
1862 	[OP_SECINFO_NO_NAME]	= (nfsd4_dec)nfsd4_decode_secinfo_no_name,
1863 	[OP_SEQUENCE]		= (nfsd4_dec)nfsd4_decode_sequence,
1864 	[OP_SET_SSV]		= (nfsd4_dec)nfsd4_decode_notsupp,
1865 	[OP_TEST_STATEID]	= (nfsd4_dec)nfsd4_decode_test_stateid,
1866 	[OP_WANT_DELEGATION]	= (nfsd4_dec)nfsd4_decode_notsupp,
1867 	[OP_DESTROY_CLIENTID]	= (nfsd4_dec)nfsd4_decode_destroy_clientid,
1868 	[OP_RECLAIM_COMPLETE]	= (nfsd4_dec)nfsd4_decode_reclaim_complete,
1869 
1870 	/* new operations for NFSv4.2 */
1871 	[OP_ALLOCATE]		= (nfsd4_dec)nfsd4_decode_fallocate,
1872 	[OP_COPY]		= (nfsd4_dec)nfsd4_decode_copy,
1873 	[OP_COPY_NOTIFY]	= (nfsd4_dec)nfsd4_decode_notsupp,
1874 	[OP_DEALLOCATE]		= (nfsd4_dec)nfsd4_decode_fallocate,
1875 	[OP_IO_ADVISE]		= (nfsd4_dec)nfsd4_decode_notsupp,
1876 	[OP_LAYOUTERROR]	= (nfsd4_dec)nfsd4_decode_notsupp,
1877 	[OP_LAYOUTSTATS]	= (nfsd4_dec)nfsd4_decode_notsupp,
1878 	[OP_OFFLOAD_CANCEL]	= (nfsd4_dec)nfsd4_decode_notsupp,
1879 	[OP_OFFLOAD_STATUS]	= (nfsd4_dec)nfsd4_decode_notsupp,
1880 	[OP_READ_PLUS]		= (nfsd4_dec)nfsd4_decode_notsupp,
1881 	[OP_SEEK]		= (nfsd4_dec)nfsd4_decode_seek,
1882 	[OP_WRITE_SAME]		= (nfsd4_dec)nfsd4_decode_notsupp,
1883 	[OP_CLONE]		= (nfsd4_dec)nfsd4_decode_clone,
1884 };
1885 
1886 static inline bool
1887 nfsd4_opnum_in_range(struct nfsd4_compoundargs *argp, struct nfsd4_op *op)
1888 {
1889 	if (op->opnum < FIRST_NFS4_OP)
1890 		return false;
1891 	else if (argp->minorversion == 0 && op->opnum > LAST_NFS40_OP)
1892 		return false;
1893 	else if (argp->minorversion == 1 && op->opnum > LAST_NFS41_OP)
1894 		return false;
1895 	else if (argp->minorversion == 2 && op->opnum > LAST_NFS42_OP)
1896 		return false;
1897 	return true;
1898 }
1899 
1900 static __be32
1901 nfsd4_decode_compound(struct nfsd4_compoundargs *argp)
1902 {
1903 	DECODE_HEAD;
1904 	struct nfsd4_op *op;
1905 	bool cachethis = false;
1906 	int auth_slack= argp->rqstp->rq_auth_slack;
1907 	int max_reply = auth_slack + 8; /* opcnt, status */
1908 	int readcount = 0;
1909 	int readbytes = 0;
1910 	int i;
1911 
1912 	READ_BUF(4);
1913 	argp->taglen = be32_to_cpup(p++);
1914 	READ_BUF(argp->taglen);
1915 	SAVEMEM(argp->tag, argp->taglen);
1916 	READ_BUF(8);
1917 	argp->minorversion = be32_to_cpup(p++);
1918 	argp->opcnt = be32_to_cpup(p++);
1919 	max_reply += 4 + (XDR_QUADLEN(argp->taglen) << 2);
1920 
1921 	if (argp->taglen > NFSD4_MAX_TAGLEN)
1922 		goto xdr_error;
1923 	/*
1924 	 * NFS4ERR_RESOURCE is a more helpful error than GARBAGE_ARGS
1925 	 * here, so we return success at the xdr level so that
1926 	 * nfsd4_proc can handle this is an NFS-level error.
1927 	 */
1928 	if (argp->opcnt > NFSD_MAX_OPS_PER_COMPOUND)
1929 		return 0;
1930 
1931 	if (argp->opcnt > ARRAY_SIZE(argp->iops)) {
1932 		argp->ops = kzalloc(argp->opcnt * sizeof(*argp->ops), GFP_KERNEL);
1933 		if (!argp->ops) {
1934 			argp->ops = argp->iops;
1935 			dprintk("nfsd: couldn't allocate room for COMPOUND\n");
1936 			goto xdr_error;
1937 		}
1938 	}
1939 
1940 	if (argp->minorversion > NFSD_SUPPORTED_MINOR_VERSION)
1941 		argp->opcnt = 0;
1942 
1943 	for (i = 0; i < argp->opcnt; i++) {
1944 		op = &argp->ops[i];
1945 		op->replay = NULL;
1946 
1947 		READ_BUF(4);
1948 		op->opnum = be32_to_cpup(p++);
1949 
1950 		if (nfsd4_opnum_in_range(argp, op))
1951 			op->status = nfsd4_dec_ops[op->opnum](argp, &op->u);
1952 		else {
1953 			op->opnum = OP_ILLEGAL;
1954 			op->status = nfserr_op_illegal;
1955 		}
1956 		op->opdesc = OPDESC(op);
1957 		/*
1958 		 * We'll try to cache the result in the DRC if any one
1959 		 * op in the compound wants to be cached:
1960 		 */
1961 		cachethis |= nfsd4_cache_this_op(op);
1962 
1963 		if (op->opnum == OP_READ) {
1964 			readcount++;
1965 			readbytes += nfsd4_max_reply(argp->rqstp, op);
1966 		} else
1967 			max_reply += nfsd4_max_reply(argp->rqstp, op);
1968 		/*
1969 		 * OP_LOCK and OP_LOCKT may return a conflicting lock.
1970 		 * (Special case because it will just skip encoding this
1971 		 * if it runs out of xdr buffer space, and it is the only
1972 		 * operation that behaves this way.)
1973 		 */
1974 		if (op->opnum == OP_LOCK || op->opnum == OP_LOCKT)
1975 			max_reply += NFS4_OPAQUE_LIMIT;
1976 
1977 		if (op->status) {
1978 			argp->opcnt = i+1;
1979 			break;
1980 		}
1981 	}
1982 	/* Sessions make the DRC unnecessary: */
1983 	if (argp->minorversion)
1984 		cachethis = false;
1985 	svc_reserve(argp->rqstp, max_reply + readbytes);
1986 	argp->rqstp->rq_cachetype = cachethis ? RC_REPLBUFF : RC_NOCACHE;
1987 
1988 	if (readcount > 1 || max_reply > PAGE_SIZE - auth_slack)
1989 		clear_bit(RQ_SPLICE_OK, &argp->rqstp->rq_flags);
1990 
1991 	DECODE_TAIL;
1992 }
1993 
1994 static __be32 *encode_change(__be32 *p, struct kstat *stat, struct inode *inode,
1995 			     struct svc_export *exp)
1996 {
1997 	if (exp->ex_flags & NFSEXP_V4ROOT) {
1998 		*p++ = cpu_to_be32(convert_to_wallclock(exp->cd->flush_time));
1999 		*p++ = 0;
2000 	} else if (IS_I_VERSION(inode)) {
2001 		p = xdr_encode_hyper(p, nfsd4_change_attribute(stat, inode));
2002 	} else {
2003 		*p++ = cpu_to_be32(stat->ctime.tv_sec);
2004 		*p++ = cpu_to_be32(stat->ctime.tv_nsec);
2005 	}
2006 	return p;
2007 }
2008 
2009 static __be32 *encode_cinfo(__be32 *p, struct nfsd4_change_info *c)
2010 {
2011 	*p++ = cpu_to_be32(c->atomic);
2012 	if (c->change_supported) {
2013 		p = xdr_encode_hyper(p, c->before_change);
2014 		p = xdr_encode_hyper(p, c->after_change);
2015 	} else {
2016 		*p++ = cpu_to_be32(c->before_ctime_sec);
2017 		*p++ = cpu_to_be32(c->before_ctime_nsec);
2018 		*p++ = cpu_to_be32(c->after_ctime_sec);
2019 		*p++ = cpu_to_be32(c->after_ctime_nsec);
2020 	}
2021 	return p;
2022 }
2023 
2024 /* Encode as an array of strings the string given with components
2025  * separated @sep, escaped with esc_enter and esc_exit.
2026  */
2027 static __be32 nfsd4_encode_components_esc(struct xdr_stream *xdr, char sep,
2028 					  char *components, char esc_enter,
2029 					  char esc_exit)
2030 {
2031 	__be32 *p;
2032 	__be32 pathlen;
2033 	int pathlen_offset;
2034 	int strlen, count=0;
2035 	char *str, *end, *next;
2036 
2037 	dprintk("nfsd4_encode_components(%s)\n", components);
2038 
2039 	pathlen_offset = xdr->buf->len;
2040 	p = xdr_reserve_space(xdr, 4);
2041 	if (!p)
2042 		return nfserr_resource;
2043 	p++; /* We will fill this in with @count later */
2044 
2045 	end = str = components;
2046 	while (*end) {
2047 		bool found_esc = false;
2048 
2049 		/* try to parse as esc_start, ..., esc_end, sep */
2050 		if (*str == esc_enter) {
2051 			for (; *end && (*end != esc_exit); end++)
2052 				/* find esc_exit or end of string */;
2053 			next = end + 1;
2054 			if (*end && (!*next || *next == sep)) {
2055 				str++;
2056 				found_esc = true;
2057 			}
2058 		}
2059 
2060 		if (!found_esc)
2061 			for (; *end && (*end != sep); end++)
2062 				/* find sep or end of string */;
2063 
2064 		strlen = end - str;
2065 		if (strlen) {
2066 			p = xdr_reserve_space(xdr, strlen + 4);
2067 			if (!p)
2068 				return nfserr_resource;
2069 			p = xdr_encode_opaque(p, str, strlen);
2070 			count++;
2071 		}
2072 		else
2073 			end++;
2074 		if (found_esc)
2075 			end = next;
2076 
2077 		str = end;
2078 	}
2079 	pathlen = htonl(count);
2080 	write_bytes_to_xdr_buf(xdr->buf, pathlen_offset, &pathlen, 4);
2081 	return 0;
2082 }
2083 
2084 /* Encode as an array of strings the string given with components
2085  * separated @sep.
2086  */
2087 static __be32 nfsd4_encode_components(struct xdr_stream *xdr, char sep,
2088 				      char *components)
2089 {
2090 	return nfsd4_encode_components_esc(xdr, sep, components, 0, 0);
2091 }
2092 
2093 /*
2094  * encode a location element of a fs_locations structure
2095  */
2096 static __be32 nfsd4_encode_fs_location4(struct xdr_stream *xdr,
2097 					struct nfsd4_fs_location *location)
2098 {
2099 	__be32 status;
2100 
2101 	status = nfsd4_encode_components_esc(xdr, ':', location->hosts,
2102 						'[', ']');
2103 	if (status)
2104 		return status;
2105 	status = nfsd4_encode_components(xdr, '/', location->path);
2106 	if (status)
2107 		return status;
2108 	return 0;
2109 }
2110 
2111 /*
2112  * Encode a path in RFC3530 'pathname4' format
2113  */
2114 static __be32 nfsd4_encode_path(struct xdr_stream *xdr,
2115 				const struct path *root,
2116 				const struct path *path)
2117 {
2118 	struct path cur = *path;
2119 	__be32 *p;
2120 	struct dentry **components = NULL;
2121 	unsigned int ncomponents = 0;
2122 	__be32 err = nfserr_jukebox;
2123 
2124 	dprintk("nfsd4_encode_components(");
2125 
2126 	path_get(&cur);
2127 	/* First walk the path up to the nfsd root, and store the
2128 	 * dentries/path components in an array.
2129 	 */
2130 	for (;;) {
2131 		if (path_equal(&cur, root))
2132 			break;
2133 		if (cur.dentry == cur.mnt->mnt_root) {
2134 			if (follow_up(&cur))
2135 				continue;
2136 			goto out_free;
2137 		}
2138 		if ((ncomponents & 15) == 0) {
2139 			struct dentry **new;
2140 			new = krealloc(components,
2141 					sizeof(*new) * (ncomponents + 16),
2142 					GFP_KERNEL);
2143 			if (!new)
2144 				goto out_free;
2145 			components = new;
2146 		}
2147 		components[ncomponents++] = cur.dentry;
2148 		cur.dentry = dget_parent(cur.dentry);
2149 	}
2150 	err = nfserr_resource;
2151 	p = xdr_reserve_space(xdr, 4);
2152 	if (!p)
2153 		goto out_free;
2154 	*p++ = cpu_to_be32(ncomponents);
2155 
2156 	while (ncomponents) {
2157 		struct dentry *dentry = components[ncomponents - 1];
2158 		unsigned int len;
2159 
2160 		spin_lock(&dentry->d_lock);
2161 		len = dentry->d_name.len;
2162 		p = xdr_reserve_space(xdr, len + 4);
2163 		if (!p) {
2164 			spin_unlock(&dentry->d_lock);
2165 			goto out_free;
2166 		}
2167 		p = xdr_encode_opaque(p, dentry->d_name.name, len);
2168 		dprintk("/%pd", dentry);
2169 		spin_unlock(&dentry->d_lock);
2170 		dput(dentry);
2171 		ncomponents--;
2172 	}
2173 
2174 	err = 0;
2175 out_free:
2176 	dprintk(")\n");
2177 	while (ncomponents)
2178 		dput(components[--ncomponents]);
2179 	kfree(components);
2180 	path_put(&cur);
2181 	return err;
2182 }
2183 
2184 static __be32 nfsd4_encode_fsloc_fsroot(struct xdr_stream *xdr,
2185 			struct svc_rqst *rqstp, const struct path *path)
2186 {
2187 	struct svc_export *exp_ps;
2188 	__be32 res;
2189 
2190 	exp_ps = rqst_find_fsidzero_export(rqstp);
2191 	if (IS_ERR(exp_ps))
2192 		return nfserrno(PTR_ERR(exp_ps));
2193 	res = nfsd4_encode_path(xdr, &exp_ps->ex_path, path);
2194 	exp_put(exp_ps);
2195 	return res;
2196 }
2197 
2198 /*
2199  *  encode a fs_locations structure
2200  */
2201 static __be32 nfsd4_encode_fs_locations(struct xdr_stream *xdr,
2202 			struct svc_rqst *rqstp, struct svc_export *exp)
2203 {
2204 	__be32 status;
2205 	int i;
2206 	__be32 *p;
2207 	struct nfsd4_fs_locations *fslocs = &exp->ex_fslocs;
2208 
2209 	status = nfsd4_encode_fsloc_fsroot(xdr, rqstp, &exp->ex_path);
2210 	if (status)
2211 		return status;
2212 	p = xdr_reserve_space(xdr, 4);
2213 	if (!p)
2214 		return nfserr_resource;
2215 	*p++ = cpu_to_be32(fslocs->locations_count);
2216 	for (i=0; i<fslocs->locations_count; i++) {
2217 		status = nfsd4_encode_fs_location4(xdr, &fslocs->locations[i]);
2218 		if (status)
2219 			return status;
2220 	}
2221 	return 0;
2222 }
2223 
2224 static u32 nfs4_file_type(umode_t mode)
2225 {
2226 	switch (mode & S_IFMT) {
2227 	case S_IFIFO:	return NF4FIFO;
2228 	case S_IFCHR:	return NF4CHR;
2229 	case S_IFDIR:	return NF4DIR;
2230 	case S_IFBLK:	return NF4BLK;
2231 	case S_IFLNK:	return NF4LNK;
2232 	case S_IFREG:	return NF4REG;
2233 	case S_IFSOCK:	return NF4SOCK;
2234 	default:	return NF4BAD;
2235 	};
2236 }
2237 
2238 static inline __be32
2239 nfsd4_encode_aclname(struct xdr_stream *xdr, struct svc_rqst *rqstp,
2240 		     struct nfs4_ace *ace)
2241 {
2242 	if (ace->whotype != NFS4_ACL_WHO_NAMED)
2243 		return nfs4_acl_write_who(xdr, ace->whotype);
2244 	else if (ace->flag & NFS4_ACE_IDENTIFIER_GROUP)
2245 		return nfsd4_encode_group(xdr, rqstp, ace->who_gid);
2246 	else
2247 		return nfsd4_encode_user(xdr, rqstp, ace->who_uid);
2248 }
2249 
2250 static inline __be32
2251 nfsd4_encode_layout_types(struct xdr_stream *xdr, u32 layout_types)
2252 {
2253 	__be32		*p;
2254 	unsigned long	i = hweight_long(layout_types);
2255 
2256 	p = xdr_reserve_space(xdr, 4 + 4 * i);
2257 	if (!p)
2258 		return nfserr_resource;
2259 
2260 	*p++ = cpu_to_be32(i);
2261 
2262 	for (i = LAYOUT_NFSV4_1_FILES; i < LAYOUT_TYPE_MAX; ++i)
2263 		if (layout_types & (1 << i))
2264 			*p++ = cpu_to_be32(i);
2265 
2266 	return 0;
2267 }
2268 
2269 #define WORD0_ABSENT_FS_ATTRS (FATTR4_WORD0_FS_LOCATIONS | FATTR4_WORD0_FSID | \
2270 			      FATTR4_WORD0_RDATTR_ERROR)
2271 #define WORD1_ABSENT_FS_ATTRS FATTR4_WORD1_MOUNTED_ON_FILEID
2272 #define WORD2_ABSENT_FS_ATTRS 0
2273 
2274 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
2275 static inline __be32
2276 nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
2277 			    void *context, int len)
2278 {
2279 	__be32 *p;
2280 
2281 	p = xdr_reserve_space(xdr, len + 4 + 4 + 4);
2282 	if (!p)
2283 		return nfserr_resource;
2284 
2285 	/*
2286 	 * For now we use a 0 here to indicate the null translation; in
2287 	 * the future we may place a call to translation code here.
2288 	 */
2289 	*p++ = cpu_to_be32(0); /* lfs */
2290 	*p++ = cpu_to_be32(0); /* pi */
2291 	p = xdr_encode_opaque(p, context, len);
2292 	return 0;
2293 }
2294 #else
2295 static inline __be32
2296 nfsd4_encode_security_label(struct xdr_stream *xdr, struct svc_rqst *rqstp,
2297 			    void *context, int len)
2298 { return 0; }
2299 #endif
2300 
2301 static __be32 fattr_handle_absent_fs(u32 *bmval0, u32 *bmval1, u32 *bmval2, u32 *rdattr_err)
2302 {
2303 	/* As per referral draft:  */
2304 	if (*bmval0 & ~WORD0_ABSENT_FS_ATTRS ||
2305 	    *bmval1 & ~WORD1_ABSENT_FS_ATTRS) {
2306 		if (*bmval0 & FATTR4_WORD0_RDATTR_ERROR ||
2307 	            *bmval0 & FATTR4_WORD0_FS_LOCATIONS)
2308 			*rdattr_err = NFSERR_MOVED;
2309 		else
2310 			return nfserr_moved;
2311 	}
2312 	*bmval0 &= WORD0_ABSENT_FS_ATTRS;
2313 	*bmval1 &= WORD1_ABSENT_FS_ATTRS;
2314 	*bmval2 &= WORD2_ABSENT_FS_ATTRS;
2315 	return 0;
2316 }
2317 
2318 
2319 static int get_parent_attributes(struct svc_export *exp, struct kstat *stat)
2320 {
2321 	struct path path = exp->ex_path;
2322 	int err;
2323 
2324 	path_get(&path);
2325 	while (follow_up(&path)) {
2326 		if (path.dentry != path.mnt->mnt_root)
2327 			break;
2328 	}
2329 	err = vfs_getattr(&path, stat, STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT);
2330 	path_put(&path);
2331 	return err;
2332 }
2333 
2334 static __be32
2335 nfsd4_encode_bitmap(struct xdr_stream *xdr, u32 bmval0, u32 bmval1, u32 bmval2)
2336 {
2337 	__be32 *p;
2338 
2339 	if (bmval2) {
2340 		p = xdr_reserve_space(xdr, 16);
2341 		if (!p)
2342 			goto out_resource;
2343 		*p++ = cpu_to_be32(3);
2344 		*p++ = cpu_to_be32(bmval0);
2345 		*p++ = cpu_to_be32(bmval1);
2346 		*p++ = cpu_to_be32(bmval2);
2347 	} else if (bmval1) {
2348 		p = xdr_reserve_space(xdr, 12);
2349 		if (!p)
2350 			goto out_resource;
2351 		*p++ = cpu_to_be32(2);
2352 		*p++ = cpu_to_be32(bmval0);
2353 		*p++ = cpu_to_be32(bmval1);
2354 	} else {
2355 		p = xdr_reserve_space(xdr, 8);
2356 		if (!p)
2357 			goto out_resource;
2358 		*p++ = cpu_to_be32(1);
2359 		*p++ = cpu_to_be32(bmval0);
2360 	}
2361 
2362 	return 0;
2363 out_resource:
2364 	return nfserr_resource;
2365 }
2366 
2367 /*
2368  * Note: @fhp can be NULL; in this case, we might have to compose the filehandle
2369  * ourselves.
2370  */
2371 static __be32
2372 nfsd4_encode_fattr(struct xdr_stream *xdr, struct svc_fh *fhp,
2373 		struct svc_export *exp,
2374 		struct dentry *dentry, u32 *bmval,
2375 		struct svc_rqst *rqstp, int ignore_crossmnt)
2376 {
2377 	u32 bmval0 = bmval[0];
2378 	u32 bmval1 = bmval[1];
2379 	u32 bmval2 = bmval[2];
2380 	struct kstat stat;
2381 	struct svc_fh *tempfh = NULL;
2382 	struct kstatfs statfs;
2383 	__be32 *p;
2384 	int starting_len = xdr->buf->len;
2385 	int attrlen_offset;
2386 	__be32 attrlen;
2387 	u32 dummy;
2388 	u64 dummy64;
2389 	u32 rdattr_err = 0;
2390 	__be32 status;
2391 	int err;
2392 	struct nfs4_acl *acl = NULL;
2393 	void *context = NULL;
2394 	int contextlen;
2395 	bool contextsupport = false;
2396 	struct nfsd4_compoundres *resp = rqstp->rq_resp;
2397 	u32 minorversion = resp->cstate.minorversion;
2398 	struct path path = {
2399 		.mnt	= exp->ex_path.mnt,
2400 		.dentry	= dentry,
2401 	};
2402 	struct nfsd_net *nn = net_generic(SVC_NET(rqstp), nfsd_net_id);
2403 
2404 	BUG_ON(bmval1 & NFSD_WRITEONLY_ATTRS_WORD1);
2405 	BUG_ON(!nfsd_attrs_supported(minorversion, bmval));
2406 
2407 	if (exp->ex_fslocs.migrated) {
2408 		status = fattr_handle_absent_fs(&bmval0, &bmval1, &bmval2, &rdattr_err);
2409 		if (status)
2410 			goto out;
2411 	}
2412 
2413 	err = vfs_getattr(&path, &stat, STATX_BASIC_STATS, AT_STATX_SYNC_AS_STAT);
2414 	if (err)
2415 		goto out_nfserr;
2416 	if ((bmval0 & (FATTR4_WORD0_FILES_AVAIL | FATTR4_WORD0_FILES_FREE |
2417 			FATTR4_WORD0_FILES_TOTAL | FATTR4_WORD0_MAXNAME)) ||
2418 	    (bmval1 & (FATTR4_WORD1_SPACE_AVAIL | FATTR4_WORD1_SPACE_FREE |
2419 		       FATTR4_WORD1_SPACE_TOTAL))) {
2420 		err = vfs_statfs(&path, &statfs);
2421 		if (err)
2422 			goto out_nfserr;
2423 	}
2424 	if ((bmval0 & (FATTR4_WORD0_FILEHANDLE | FATTR4_WORD0_FSID)) && !fhp) {
2425 		tempfh = kmalloc(sizeof(struct svc_fh), GFP_KERNEL);
2426 		status = nfserr_jukebox;
2427 		if (!tempfh)
2428 			goto out;
2429 		fh_init(tempfh, NFS4_FHSIZE);
2430 		status = fh_compose(tempfh, exp, dentry, NULL);
2431 		if (status)
2432 			goto out;
2433 		fhp = tempfh;
2434 	}
2435 	if (bmval0 & FATTR4_WORD0_ACL) {
2436 		err = nfsd4_get_nfs4_acl(rqstp, dentry, &acl);
2437 		if (err == -EOPNOTSUPP)
2438 			bmval0 &= ~FATTR4_WORD0_ACL;
2439 		else if (err == -EINVAL) {
2440 			status = nfserr_attrnotsupp;
2441 			goto out;
2442 		} else if (err != 0)
2443 			goto out_nfserr;
2444 	}
2445 
2446 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
2447 	if ((bmval2 & FATTR4_WORD2_SECURITY_LABEL) ||
2448 	     bmval0 & FATTR4_WORD0_SUPPORTED_ATTRS) {
2449 		if (exp->ex_flags & NFSEXP_SECURITY_LABEL)
2450 			err = security_inode_getsecctx(d_inode(dentry),
2451 						&context, &contextlen);
2452 		else
2453 			err = -EOPNOTSUPP;
2454 		contextsupport = (err == 0);
2455 		if (bmval2 & FATTR4_WORD2_SECURITY_LABEL) {
2456 			if (err == -EOPNOTSUPP)
2457 				bmval2 &= ~FATTR4_WORD2_SECURITY_LABEL;
2458 			else if (err)
2459 				goto out_nfserr;
2460 		}
2461 	}
2462 #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
2463 
2464 	status = nfsd4_encode_bitmap(xdr, bmval0, bmval1, bmval2);
2465 	if (status)
2466 		goto out;
2467 
2468 	attrlen_offset = xdr->buf->len;
2469 	p = xdr_reserve_space(xdr, 4);
2470 	if (!p)
2471 		goto out_resource;
2472 	p++;                /* to be backfilled later */
2473 
2474 	if (bmval0 & FATTR4_WORD0_SUPPORTED_ATTRS) {
2475 		u32 supp[3];
2476 
2477 		memcpy(supp, nfsd_suppattrs[minorversion], sizeof(supp));
2478 
2479 		if (!IS_POSIXACL(dentry->d_inode))
2480 			supp[0] &= ~FATTR4_WORD0_ACL;
2481 		if (!contextsupport)
2482 			supp[2] &= ~FATTR4_WORD2_SECURITY_LABEL;
2483 		if (!supp[2]) {
2484 			p = xdr_reserve_space(xdr, 12);
2485 			if (!p)
2486 				goto out_resource;
2487 			*p++ = cpu_to_be32(2);
2488 			*p++ = cpu_to_be32(supp[0]);
2489 			*p++ = cpu_to_be32(supp[1]);
2490 		} else {
2491 			p = xdr_reserve_space(xdr, 16);
2492 			if (!p)
2493 				goto out_resource;
2494 			*p++ = cpu_to_be32(3);
2495 			*p++ = cpu_to_be32(supp[0]);
2496 			*p++ = cpu_to_be32(supp[1]);
2497 			*p++ = cpu_to_be32(supp[2]);
2498 		}
2499 	}
2500 	if (bmval0 & FATTR4_WORD0_TYPE) {
2501 		p = xdr_reserve_space(xdr, 4);
2502 		if (!p)
2503 			goto out_resource;
2504 		dummy = nfs4_file_type(stat.mode);
2505 		if (dummy == NF4BAD) {
2506 			status = nfserr_serverfault;
2507 			goto out;
2508 		}
2509 		*p++ = cpu_to_be32(dummy);
2510 	}
2511 	if (bmval0 & FATTR4_WORD0_FH_EXPIRE_TYPE) {
2512 		p = xdr_reserve_space(xdr, 4);
2513 		if (!p)
2514 			goto out_resource;
2515 		if (exp->ex_flags & NFSEXP_NOSUBTREECHECK)
2516 			*p++ = cpu_to_be32(NFS4_FH_PERSISTENT);
2517 		else
2518 			*p++ = cpu_to_be32(NFS4_FH_PERSISTENT|
2519 						NFS4_FH_VOL_RENAME);
2520 	}
2521 	if (bmval0 & FATTR4_WORD0_CHANGE) {
2522 		p = xdr_reserve_space(xdr, 8);
2523 		if (!p)
2524 			goto out_resource;
2525 		p = encode_change(p, &stat, d_inode(dentry), exp);
2526 	}
2527 	if (bmval0 & FATTR4_WORD0_SIZE) {
2528 		p = xdr_reserve_space(xdr, 8);
2529 		if (!p)
2530 			goto out_resource;
2531 		p = xdr_encode_hyper(p, stat.size);
2532 	}
2533 	if (bmval0 & FATTR4_WORD0_LINK_SUPPORT) {
2534 		p = xdr_reserve_space(xdr, 4);
2535 		if (!p)
2536 			goto out_resource;
2537 		*p++ = cpu_to_be32(1);
2538 	}
2539 	if (bmval0 & FATTR4_WORD0_SYMLINK_SUPPORT) {
2540 		p = xdr_reserve_space(xdr, 4);
2541 		if (!p)
2542 			goto out_resource;
2543 		*p++ = cpu_to_be32(1);
2544 	}
2545 	if (bmval0 & FATTR4_WORD0_NAMED_ATTR) {
2546 		p = xdr_reserve_space(xdr, 4);
2547 		if (!p)
2548 			goto out_resource;
2549 		*p++ = cpu_to_be32(0);
2550 	}
2551 	if (bmval0 & FATTR4_WORD0_FSID) {
2552 		p = xdr_reserve_space(xdr, 16);
2553 		if (!p)
2554 			goto out_resource;
2555 		if (exp->ex_fslocs.migrated) {
2556 			p = xdr_encode_hyper(p, NFS4_REFERRAL_FSID_MAJOR);
2557 			p = xdr_encode_hyper(p, NFS4_REFERRAL_FSID_MINOR);
2558 		} else switch(fsid_source(fhp)) {
2559 		case FSIDSOURCE_FSID:
2560 			p = xdr_encode_hyper(p, (u64)exp->ex_fsid);
2561 			p = xdr_encode_hyper(p, (u64)0);
2562 			break;
2563 		case FSIDSOURCE_DEV:
2564 			*p++ = cpu_to_be32(0);
2565 			*p++ = cpu_to_be32(MAJOR(stat.dev));
2566 			*p++ = cpu_to_be32(0);
2567 			*p++ = cpu_to_be32(MINOR(stat.dev));
2568 			break;
2569 		case FSIDSOURCE_UUID:
2570 			p = xdr_encode_opaque_fixed(p, exp->ex_uuid,
2571 								EX_UUID_LEN);
2572 			break;
2573 		}
2574 	}
2575 	if (bmval0 & FATTR4_WORD0_UNIQUE_HANDLES) {
2576 		p = xdr_reserve_space(xdr, 4);
2577 		if (!p)
2578 			goto out_resource;
2579 		*p++ = cpu_to_be32(0);
2580 	}
2581 	if (bmval0 & FATTR4_WORD0_LEASE_TIME) {
2582 		p = xdr_reserve_space(xdr, 4);
2583 		if (!p)
2584 			goto out_resource;
2585 		*p++ = cpu_to_be32(nn->nfsd4_lease);
2586 	}
2587 	if (bmval0 & FATTR4_WORD0_RDATTR_ERROR) {
2588 		p = xdr_reserve_space(xdr, 4);
2589 		if (!p)
2590 			goto out_resource;
2591 		*p++ = cpu_to_be32(rdattr_err);
2592 	}
2593 	if (bmval0 & FATTR4_WORD0_ACL) {
2594 		struct nfs4_ace *ace;
2595 
2596 		if (acl == NULL) {
2597 			p = xdr_reserve_space(xdr, 4);
2598 			if (!p)
2599 				goto out_resource;
2600 
2601 			*p++ = cpu_to_be32(0);
2602 			goto out_acl;
2603 		}
2604 		p = xdr_reserve_space(xdr, 4);
2605 		if (!p)
2606 			goto out_resource;
2607 		*p++ = cpu_to_be32(acl->naces);
2608 
2609 		for (ace = acl->aces; ace < acl->aces + acl->naces; ace++) {
2610 			p = xdr_reserve_space(xdr, 4*3);
2611 			if (!p)
2612 				goto out_resource;
2613 			*p++ = cpu_to_be32(ace->type);
2614 			*p++ = cpu_to_be32(ace->flag);
2615 			*p++ = cpu_to_be32(ace->access_mask &
2616 							NFS4_ACE_MASK_ALL);
2617 			status = nfsd4_encode_aclname(xdr, rqstp, ace);
2618 			if (status)
2619 				goto out;
2620 		}
2621 	}
2622 out_acl:
2623 	if (bmval0 & FATTR4_WORD0_ACLSUPPORT) {
2624 		p = xdr_reserve_space(xdr, 4);
2625 		if (!p)
2626 			goto out_resource;
2627 		*p++ = cpu_to_be32(IS_POSIXACL(dentry->d_inode) ?
2628 			ACL4_SUPPORT_ALLOW_ACL|ACL4_SUPPORT_DENY_ACL : 0);
2629 	}
2630 	if (bmval0 & FATTR4_WORD0_CANSETTIME) {
2631 		p = xdr_reserve_space(xdr, 4);
2632 		if (!p)
2633 			goto out_resource;
2634 		*p++ = cpu_to_be32(1);
2635 	}
2636 	if (bmval0 & FATTR4_WORD0_CASE_INSENSITIVE) {
2637 		p = xdr_reserve_space(xdr, 4);
2638 		if (!p)
2639 			goto out_resource;
2640 		*p++ = cpu_to_be32(0);
2641 	}
2642 	if (bmval0 & FATTR4_WORD0_CASE_PRESERVING) {
2643 		p = xdr_reserve_space(xdr, 4);
2644 		if (!p)
2645 			goto out_resource;
2646 		*p++ = cpu_to_be32(1);
2647 	}
2648 	if (bmval0 & FATTR4_WORD0_CHOWN_RESTRICTED) {
2649 		p = xdr_reserve_space(xdr, 4);
2650 		if (!p)
2651 			goto out_resource;
2652 		*p++ = cpu_to_be32(1);
2653 	}
2654 	if (bmval0 & FATTR4_WORD0_FILEHANDLE) {
2655 		p = xdr_reserve_space(xdr, fhp->fh_handle.fh_size + 4);
2656 		if (!p)
2657 			goto out_resource;
2658 		p = xdr_encode_opaque(p, &fhp->fh_handle.fh_base,
2659 					fhp->fh_handle.fh_size);
2660 	}
2661 	if (bmval0 & FATTR4_WORD0_FILEID) {
2662 		p = xdr_reserve_space(xdr, 8);
2663 		if (!p)
2664 			goto out_resource;
2665 		p = xdr_encode_hyper(p, stat.ino);
2666 	}
2667 	if (bmval0 & FATTR4_WORD0_FILES_AVAIL) {
2668 		p = xdr_reserve_space(xdr, 8);
2669 		if (!p)
2670 			goto out_resource;
2671 		p = xdr_encode_hyper(p, (u64) statfs.f_ffree);
2672 	}
2673 	if (bmval0 & FATTR4_WORD0_FILES_FREE) {
2674 		p = xdr_reserve_space(xdr, 8);
2675 		if (!p)
2676 			goto out_resource;
2677 		p = xdr_encode_hyper(p, (u64) statfs.f_ffree);
2678 	}
2679 	if (bmval0 & FATTR4_WORD0_FILES_TOTAL) {
2680 		p = xdr_reserve_space(xdr, 8);
2681 		if (!p)
2682 			goto out_resource;
2683 		p = xdr_encode_hyper(p, (u64) statfs.f_files);
2684 	}
2685 	if (bmval0 & FATTR4_WORD0_FS_LOCATIONS) {
2686 		status = nfsd4_encode_fs_locations(xdr, rqstp, exp);
2687 		if (status)
2688 			goto out;
2689 	}
2690 	if (bmval0 & FATTR4_WORD0_HOMOGENEOUS) {
2691 		p = xdr_reserve_space(xdr, 4);
2692 		if (!p)
2693 			goto out_resource;
2694 		*p++ = cpu_to_be32(1);
2695 	}
2696 	if (bmval0 & FATTR4_WORD0_MAXFILESIZE) {
2697 		p = xdr_reserve_space(xdr, 8);
2698 		if (!p)
2699 			goto out_resource;
2700 		p = xdr_encode_hyper(p, exp->ex_path.mnt->mnt_sb->s_maxbytes);
2701 	}
2702 	if (bmval0 & FATTR4_WORD0_MAXLINK) {
2703 		p = xdr_reserve_space(xdr, 4);
2704 		if (!p)
2705 			goto out_resource;
2706 		*p++ = cpu_to_be32(255);
2707 	}
2708 	if (bmval0 & FATTR4_WORD0_MAXNAME) {
2709 		p = xdr_reserve_space(xdr, 4);
2710 		if (!p)
2711 			goto out_resource;
2712 		*p++ = cpu_to_be32(statfs.f_namelen);
2713 	}
2714 	if (bmval0 & FATTR4_WORD0_MAXREAD) {
2715 		p = xdr_reserve_space(xdr, 8);
2716 		if (!p)
2717 			goto out_resource;
2718 		p = xdr_encode_hyper(p, (u64) svc_max_payload(rqstp));
2719 	}
2720 	if (bmval0 & FATTR4_WORD0_MAXWRITE) {
2721 		p = xdr_reserve_space(xdr, 8);
2722 		if (!p)
2723 			goto out_resource;
2724 		p = xdr_encode_hyper(p, (u64) svc_max_payload(rqstp));
2725 	}
2726 	if (bmval1 & FATTR4_WORD1_MODE) {
2727 		p = xdr_reserve_space(xdr, 4);
2728 		if (!p)
2729 			goto out_resource;
2730 		*p++ = cpu_to_be32(stat.mode & S_IALLUGO);
2731 	}
2732 	if (bmval1 & FATTR4_WORD1_NO_TRUNC) {
2733 		p = xdr_reserve_space(xdr, 4);
2734 		if (!p)
2735 			goto out_resource;
2736 		*p++ = cpu_to_be32(1);
2737 	}
2738 	if (bmval1 & FATTR4_WORD1_NUMLINKS) {
2739 		p = xdr_reserve_space(xdr, 4);
2740 		if (!p)
2741 			goto out_resource;
2742 		*p++ = cpu_to_be32(stat.nlink);
2743 	}
2744 	if (bmval1 & FATTR4_WORD1_OWNER) {
2745 		status = nfsd4_encode_user(xdr, rqstp, stat.uid);
2746 		if (status)
2747 			goto out;
2748 	}
2749 	if (bmval1 & FATTR4_WORD1_OWNER_GROUP) {
2750 		status = nfsd4_encode_group(xdr, rqstp, stat.gid);
2751 		if (status)
2752 			goto out;
2753 	}
2754 	if (bmval1 & FATTR4_WORD1_RAWDEV) {
2755 		p = xdr_reserve_space(xdr, 8);
2756 		if (!p)
2757 			goto out_resource;
2758 		*p++ = cpu_to_be32((u32) MAJOR(stat.rdev));
2759 		*p++ = cpu_to_be32((u32) MINOR(stat.rdev));
2760 	}
2761 	if (bmval1 & FATTR4_WORD1_SPACE_AVAIL) {
2762 		p = xdr_reserve_space(xdr, 8);
2763 		if (!p)
2764 			goto out_resource;
2765 		dummy64 = (u64)statfs.f_bavail * (u64)statfs.f_bsize;
2766 		p = xdr_encode_hyper(p, dummy64);
2767 	}
2768 	if (bmval1 & FATTR4_WORD1_SPACE_FREE) {
2769 		p = xdr_reserve_space(xdr, 8);
2770 		if (!p)
2771 			goto out_resource;
2772 		dummy64 = (u64)statfs.f_bfree * (u64)statfs.f_bsize;
2773 		p = xdr_encode_hyper(p, dummy64);
2774 	}
2775 	if (bmval1 & FATTR4_WORD1_SPACE_TOTAL) {
2776 		p = xdr_reserve_space(xdr, 8);
2777 		if (!p)
2778 			goto out_resource;
2779 		dummy64 = (u64)statfs.f_blocks * (u64)statfs.f_bsize;
2780 		p = xdr_encode_hyper(p, dummy64);
2781 	}
2782 	if (bmval1 & FATTR4_WORD1_SPACE_USED) {
2783 		p = xdr_reserve_space(xdr, 8);
2784 		if (!p)
2785 			goto out_resource;
2786 		dummy64 = (u64)stat.blocks << 9;
2787 		p = xdr_encode_hyper(p, dummy64);
2788 	}
2789 	if (bmval1 & FATTR4_WORD1_TIME_ACCESS) {
2790 		p = xdr_reserve_space(xdr, 12);
2791 		if (!p)
2792 			goto out_resource;
2793 		p = xdr_encode_hyper(p, (s64)stat.atime.tv_sec);
2794 		*p++ = cpu_to_be32(stat.atime.tv_nsec);
2795 	}
2796 	if (bmval1 & FATTR4_WORD1_TIME_DELTA) {
2797 		p = xdr_reserve_space(xdr, 12);
2798 		if (!p)
2799 			goto out_resource;
2800 		*p++ = cpu_to_be32(0);
2801 		*p++ = cpu_to_be32(1);
2802 		*p++ = cpu_to_be32(0);
2803 	}
2804 	if (bmval1 & FATTR4_WORD1_TIME_METADATA) {
2805 		p = xdr_reserve_space(xdr, 12);
2806 		if (!p)
2807 			goto out_resource;
2808 		p = xdr_encode_hyper(p, (s64)stat.ctime.tv_sec);
2809 		*p++ = cpu_to_be32(stat.ctime.tv_nsec);
2810 	}
2811 	if (bmval1 & FATTR4_WORD1_TIME_MODIFY) {
2812 		p = xdr_reserve_space(xdr, 12);
2813 		if (!p)
2814 			goto out_resource;
2815 		p = xdr_encode_hyper(p, (s64)stat.mtime.tv_sec);
2816 		*p++ = cpu_to_be32(stat.mtime.tv_nsec);
2817 	}
2818 	if (bmval1 & FATTR4_WORD1_MOUNTED_ON_FILEID) {
2819 		struct kstat parent_stat;
2820 		u64 ino = stat.ino;
2821 
2822 		p = xdr_reserve_space(xdr, 8);
2823 		if (!p)
2824                 	goto out_resource;
2825 		/*
2826 		 * Get parent's attributes if not ignoring crossmount
2827 		 * and this is the root of a cross-mounted filesystem.
2828 		 */
2829 		if (ignore_crossmnt == 0 &&
2830 		    dentry == exp->ex_path.mnt->mnt_root) {
2831 			err = get_parent_attributes(exp, &parent_stat);
2832 			if (err)
2833 				goto out_nfserr;
2834 			ino = parent_stat.ino;
2835 		}
2836 		p = xdr_encode_hyper(p, ino);
2837 	}
2838 #ifdef CONFIG_NFSD_PNFS
2839 	if (bmval1 & FATTR4_WORD1_FS_LAYOUT_TYPES) {
2840 		status = nfsd4_encode_layout_types(xdr, exp->ex_layout_types);
2841 		if (status)
2842 			goto out;
2843 	}
2844 
2845 	if (bmval2 & FATTR4_WORD2_LAYOUT_TYPES) {
2846 		status = nfsd4_encode_layout_types(xdr, exp->ex_layout_types);
2847 		if (status)
2848 			goto out;
2849 	}
2850 
2851 	if (bmval2 & FATTR4_WORD2_LAYOUT_BLKSIZE) {
2852 		p = xdr_reserve_space(xdr, 4);
2853 		if (!p)
2854 			goto out_resource;
2855 		*p++ = cpu_to_be32(stat.blksize);
2856 	}
2857 #endif /* CONFIG_NFSD_PNFS */
2858 	if (bmval2 & FATTR4_WORD2_SUPPATTR_EXCLCREAT) {
2859 		u32 supp[3];
2860 
2861 		memcpy(supp, nfsd_suppattrs[minorversion], sizeof(supp));
2862 		supp[0] &= NFSD_SUPPATTR_EXCLCREAT_WORD0;
2863 		supp[1] &= NFSD_SUPPATTR_EXCLCREAT_WORD1;
2864 		supp[2] &= NFSD_SUPPATTR_EXCLCREAT_WORD2;
2865 
2866 		status = nfsd4_encode_bitmap(xdr, supp[0], supp[1], supp[2]);
2867 		if (status)
2868 			goto out;
2869 	}
2870 
2871 	if (bmval2 & FATTR4_WORD2_SECURITY_LABEL) {
2872 		status = nfsd4_encode_security_label(xdr, rqstp, context,
2873 								contextlen);
2874 		if (status)
2875 			goto out;
2876 	}
2877 
2878 	attrlen = htonl(xdr->buf->len - attrlen_offset - 4);
2879 	write_bytes_to_xdr_buf(xdr->buf, attrlen_offset, &attrlen, 4);
2880 	status = nfs_ok;
2881 
2882 out:
2883 #ifdef CONFIG_NFSD_V4_SECURITY_LABEL
2884 	if (context)
2885 		security_release_secctx(context, contextlen);
2886 #endif /* CONFIG_NFSD_V4_SECURITY_LABEL */
2887 	kfree(acl);
2888 	if (tempfh) {
2889 		fh_put(tempfh);
2890 		kfree(tempfh);
2891 	}
2892 	if (status)
2893 		xdr_truncate_encode(xdr, starting_len);
2894 	return status;
2895 out_nfserr:
2896 	status = nfserrno(err);
2897 	goto out;
2898 out_resource:
2899 	status = nfserr_resource;
2900 	goto out;
2901 }
2902 
2903 static void svcxdr_init_encode_from_buffer(struct xdr_stream *xdr,
2904 				struct xdr_buf *buf, __be32 *p, int bytes)
2905 {
2906 	xdr->scratch.iov_len = 0;
2907 	memset(buf, 0, sizeof(struct xdr_buf));
2908 	buf->head[0].iov_base = p;
2909 	buf->head[0].iov_len = 0;
2910 	buf->len = 0;
2911 	xdr->buf = buf;
2912 	xdr->iov = buf->head;
2913 	xdr->p = p;
2914 	xdr->end = (void *)p + bytes;
2915 	buf->buflen = bytes;
2916 }
2917 
2918 __be32 nfsd4_encode_fattr_to_buf(__be32 **p, int words,
2919 			struct svc_fh *fhp, struct svc_export *exp,
2920 			struct dentry *dentry, u32 *bmval,
2921 			struct svc_rqst *rqstp, int ignore_crossmnt)
2922 {
2923 	struct xdr_buf dummy;
2924 	struct xdr_stream xdr;
2925 	__be32 ret;
2926 
2927 	svcxdr_init_encode_from_buffer(&xdr, &dummy, *p, words << 2);
2928 	ret = nfsd4_encode_fattr(&xdr, fhp, exp, dentry, bmval, rqstp,
2929 							ignore_crossmnt);
2930 	*p = xdr.p;
2931 	return ret;
2932 }
2933 
2934 static inline int attributes_need_mount(u32 *bmval)
2935 {
2936 	if (bmval[0] & ~(FATTR4_WORD0_RDATTR_ERROR | FATTR4_WORD0_LEASE_TIME))
2937 		return 1;
2938 	if (bmval[1] & ~FATTR4_WORD1_MOUNTED_ON_FILEID)
2939 		return 1;
2940 	return 0;
2941 }
2942 
2943 static __be32
2944 nfsd4_encode_dirent_fattr(struct xdr_stream *xdr, struct nfsd4_readdir *cd,
2945 			const char *name, int namlen)
2946 {
2947 	struct svc_export *exp = cd->rd_fhp->fh_export;
2948 	struct dentry *dentry;
2949 	__be32 nfserr;
2950 	int ignore_crossmnt = 0;
2951 
2952 	dentry = lookup_one_len_unlocked(name, cd->rd_fhp->fh_dentry, namlen);
2953 	if (IS_ERR(dentry))
2954 		return nfserrno(PTR_ERR(dentry));
2955 	if (d_really_is_negative(dentry)) {
2956 		/*
2957 		 * we're not holding the i_mutex here, so there's
2958 		 * a window where this directory entry could have gone
2959 		 * away.
2960 		 */
2961 		dput(dentry);
2962 		return nfserr_noent;
2963 	}
2964 
2965 	exp_get(exp);
2966 	/*
2967 	 * In the case of a mountpoint, the client may be asking for
2968 	 * attributes that are only properties of the underlying filesystem
2969 	 * as opposed to the cross-mounted file system. In such a case,
2970 	 * we will not follow the cross mount and will fill the attribtutes
2971 	 * directly from the mountpoint dentry.
2972 	 */
2973 	if (nfsd_mountpoint(dentry, exp)) {
2974 		int err;
2975 
2976 		if (!(exp->ex_flags & NFSEXP_V4ROOT)
2977 				&& !attributes_need_mount(cd->rd_bmval)) {
2978 			ignore_crossmnt = 1;
2979 			goto out_encode;
2980 		}
2981 		/*
2982 		 * Why the heck aren't we just using nfsd_lookup??
2983 		 * Different "."/".." handling?  Something else?
2984 		 * At least, add a comment here to explain....
2985 		 */
2986 		err = nfsd_cross_mnt(cd->rd_rqstp, &dentry, &exp);
2987 		if (err) {
2988 			nfserr = nfserrno(err);
2989 			goto out_put;
2990 		}
2991 		nfserr = check_nfsd_access(exp, cd->rd_rqstp);
2992 		if (nfserr)
2993 			goto out_put;
2994 
2995 	}
2996 out_encode:
2997 	nfserr = nfsd4_encode_fattr(xdr, NULL, exp, dentry, cd->rd_bmval,
2998 					cd->rd_rqstp, ignore_crossmnt);
2999 out_put:
3000 	dput(dentry);
3001 	exp_put(exp);
3002 	return nfserr;
3003 }
3004 
3005 static __be32 *
3006 nfsd4_encode_rdattr_error(struct xdr_stream *xdr, __be32 nfserr)
3007 {
3008 	__be32 *p;
3009 
3010 	p = xdr_reserve_space(xdr, 20);
3011 	if (!p)
3012 		return NULL;
3013 	*p++ = htonl(2);
3014 	*p++ = htonl(FATTR4_WORD0_RDATTR_ERROR); /* bmval0 */
3015 	*p++ = htonl(0);			 /* bmval1 */
3016 
3017 	*p++ = htonl(4);     /* attribute length */
3018 	*p++ = nfserr;       /* no htonl */
3019 	return p;
3020 }
3021 
3022 static int
3023 nfsd4_encode_dirent(void *ccdv, const char *name, int namlen,
3024 		    loff_t offset, u64 ino, unsigned int d_type)
3025 {
3026 	struct readdir_cd *ccd = ccdv;
3027 	struct nfsd4_readdir *cd = container_of(ccd, struct nfsd4_readdir, common);
3028 	struct xdr_stream *xdr = cd->xdr;
3029 	int start_offset = xdr->buf->len;
3030 	int cookie_offset;
3031 	u32 name_and_cookie;
3032 	int entry_bytes;
3033 	__be32 nfserr = nfserr_toosmall;
3034 	__be64 wire_offset;
3035 	__be32 *p;
3036 
3037 	/* In nfsv4, "." and ".." never make it onto the wire.. */
3038 	if (name && isdotent(name, namlen)) {
3039 		cd->common.err = nfs_ok;
3040 		return 0;
3041 	}
3042 
3043 	if (cd->cookie_offset) {
3044 		wire_offset = cpu_to_be64(offset);
3045 		write_bytes_to_xdr_buf(xdr->buf, cd->cookie_offset,
3046 							&wire_offset, 8);
3047 	}
3048 
3049 	p = xdr_reserve_space(xdr, 4);
3050 	if (!p)
3051 		goto fail;
3052 	*p++ = xdr_one;                             /* mark entry present */
3053 	cookie_offset = xdr->buf->len;
3054 	p = xdr_reserve_space(xdr, 3*4 + namlen);
3055 	if (!p)
3056 		goto fail;
3057 	p = xdr_encode_hyper(p, NFS_OFFSET_MAX);    /* offset of next entry */
3058 	p = xdr_encode_array(p, name, namlen);      /* name length & name */
3059 
3060 	nfserr = nfsd4_encode_dirent_fattr(xdr, cd, name, namlen);
3061 	switch (nfserr) {
3062 	case nfs_ok:
3063 		break;
3064 	case nfserr_resource:
3065 		nfserr = nfserr_toosmall;
3066 		goto fail;
3067 	case nfserr_noent:
3068 		xdr_truncate_encode(xdr, start_offset);
3069 		goto skip_entry;
3070 	default:
3071 		/*
3072 		 * If the client requested the RDATTR_ERROR attribute,
3073 		 * we stuff the error code into this attribute
3074 		 * and continue.  If this attribute was not requested,
3075 		 * then in accordance with the spec, we fail the
3076 		 * entire READDIR operation(!)
3077 		 */
3078 		if (!(cd->rd_bmval[0] & FATTR4_WORD0_RDATTR_ERROR))
3079 			goto fail;
3080 		p = nfsd4_encode_rdattr_error(xdr, nfserr);
3081 		if (p == NULL) {
3082 			nfserr = nfserr_toosmall;
3083 			goto fail;
3084 		}
3085 	}
3086 	nfserr = nfserr_toosmall;
3087 	entry_bytes = xdr->buf->len - start_offset;
3088 	if (entry_bytes > cd->rd_maxcount)
3089 		goto fail;
3090 	cd->rd_maxcount -= entry_bytes;
3091 	/*
3092 	 * RFC 3530 14.2.24 describes rd_dircount as only a "hint", so
3093 	 * let's always let through the first entry, at least:
3094 	 */
3095 	if (!cd->rd_dircount)
3096 		goto fail;
3097 	name_and_cookie = 4 + 4 * XDR_QUADLEN(namlen) + 8;
3098 	if (name_and_cookie > cd->rd_dircount && cd->cookie_offset)
3099 		goto fail;
3100 	cd->rd_dircount -= min(cd->rd_dircount, name_and_cookie);
3101 
3102 	cd->cookie_offset = cookie_offset;
3103 skip_entry:
3104 	cd->common.err = nfs_ok;
3105 	return 0;
3106 fail:
3107 	xdr_truncate_encode(xdr, start_offset);
3108 	cd->common.err = nfserr;
3109 	return -EINVAL;
3110 }
3111 
3112 static __be32
3113 nfsd4_encode_stateid(struct xdr_stream *xdr, stateid_t *sid)
3114 {
3115 	__be32 *p;
3116 
3117 	p = xdr_reserve_space(xdr, sizeof(stateid_t));
3118 	if (!p)
3119 		return nfserr_resource;
3120 	*p++ = cpu_to_be32(sid->si_generation);
3121 	p = xdr_encode_opaque_fixed(p, &sid->si_opaque,
3122 					sizeof(stateid_opaque_t));
3123 	return 0;
3124 }
3125 
3126 static __be32
3127 nfsd4_encode_access(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_access *access)
3128 {
3129 	struct xdr_stream *xdr = &resp->xdr;
3130 	__be32 *p;
3131 
3132 	p = xdr_reserve_space(xdr, 8);
3133 	if (!p)
3134 		return nfserr_resource;
3135 	*p++ = cpu_to_be32(access->ac_supported);
3136 	*p++ = cpu_to_be32(access->ac_resp_access);
3137 	return 0;
3138 }
3139 
3140 static __be32 nfsd4_encode_bind_conn_to_session(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_bind_conn_to_session *bcts)
3141 {
3142 	struct xdr_stream *xdr = &resp->xdr;
3143 	__be32 *p;
3144 
3145 	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN + 8);
3146 	if (!p)
3147 		return nfserr_resource;
3148 	p = xdr_encode_opaque_fixed(p, bcts->sessionid.data,
3149 					NFS4_MAX_SESSIONID_LEN);
3150 	*p++ = cpu_to_be32(bcts->dir);
3151 	/* Upshifting from TCP to RDMA is not supported */
3152 	*p++ = cpu_to_be32(0);
3153 	return 0;
3154 }
3155 
3156 static __be32
3157 nfsd4_encode_close(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_close *close)
3158 {
3159 	struct xdr_stream *xdr = &resp->xdr;
3160 
3161 	return nfsd4_encode_stateid(xdr, &close->cl_stateid);
3162 }
3163 
3164 
3165 static __be32
3166 nfsd4_encode_commit(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_commit *commit)
3167 {
3168 	struct xdr_stream *xdr = &resp->xdr;
3169 	__be32 *p;
3170 
3171 	p = xdr_reserve_space(xdr, NFS4_VERIFIER_SIZE);
3172 	if (!p)
3173 		return nfserr_resource;
3174 	p = xdr_encode_opaque_fixed(p, commit->co_verf.data,
3175 						NFS4_VERIFIER_SIZE);
3176 	return 0;
3177 }
3178 
3179 static __be32
3180 nfsd4_encode_create(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_create *create)
3181 {
3182 	struct xdr_stream *xdr = &resp->xdr;
3183 	__be32 *p;
3184 
3185 	p = xdr_reserve_space(xdr, 20);
3186 	if (!p)
3187 		return nfserr_resource;
3188 	encode_cinfo(p, &create->cr_cinfo);
3189 	nfserr = nfsd4_encode_bitmap(xdr, create->cr_bmval[0],
3190 			create->cr_bmval[1], create->cr_bmval[2]);
3191 	return 0;
3192 }
3193 
3194 static __be32
3195 nfsd4_encode_getattr(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_getattr *getattr)
3196 {
3197 	struct svc_fh *fhp = getattr->ga_fhp;
3198 	struct xdr_stream *xdr = &resp->xdr;
3199 
3200 	return nfsd4_encode_fattr(xdr, fhp, fhp->fh_export, fhp->fh_dentry,
3201 				    getattr->ga_bmval, resp->rqstp, 0);
3202 }
3203 
3204 static __be32
3205 nfsd4_encode_getfh(struct nfsd4_compoundres *resp, __be32 nfserr, struct svc_fh **fhpp)
3206 {
3207 	struct xdr_stream *xdr = &resp->xdr;
3208 	struct svc_fh *fhp = *fhpp;
3209 	unsigned int len;
3210 	__be32 *p;
3211 
3212 	len = fhp->fh_handle.fh_size;
3213 	p = xdr_reserve_space(xdr, len + 4);
3214 	if (!p)
3215 		return nfserr_resource;
3216 	p = xdr_encode_opaque(p, &fhp->fh_handle.fh_base, len);
3217 	return 0;
3218 }
3219 
3220 /*
3221 * Including all fields other than the name, a LOCK4denied structure requires
3222 *   8(clientid) + 4(namelen) + 8(offset) + 8(length) + 4(type) = 32 bytes.
3223 */
3224 static __be32
3225 nfsd4_encode_lock_denied(struct xdr_stream *xdr, struct nfsd4_lock_denied *ld)
3226 {
3227 	struct xdr_netobj *conf = &ld->ld_owner;
3228 	__be32 *p;
3229 
3230 again:
3231 	p = xdr_reserve_space(xdr, 32 + XDR_LEN(conf->len));
3232 	if (!p) {
3233 		/*
3234 		 * Don't fail to return the result just because we can't
3235 		 * return the conflicting open:
3236 		 */
3237 		if (conf->len) {
3238 			kfree(conf->data);
3239 			conf->len = 0;
3240 			conf->data = NULL;
3241 			goto again;
3242 		}
3243 		return nfserr_resource;
3244 	}
3245 	p = xdr_encode_hyper(p, ld->ld_start);
3246 	p = xdr_encode_hyper(p, ld->ld_length);
3247 	*p++ = cpu_to_be32(ld->ld_type);
3248 	if (conf->len) {
3249 		p = xdr_encode_opaque_fixed(p, &ld->ld_clientid, 8);
3250 		p = xdr_encode_opaque(p, conf->data, conf->len);
3251 		kfree(conf->data);
3252 	}  else {  /* non - nfsv4 lock in conflict, no clientid nor owner */
3253 		p = xdr_encode_hyper(p, (u64)0); /* clientid */
3254 		*p++ = cpu_to_be32(0); /* length of owner name */
3255 	}
3256 	return nfserr_denied;
3257 }
3258 
3259 static __be32
3260 nfsd4_encode_lock(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_lock *lock)
3261 {
3262 	struct xdr_stream *xdr = &resp->xdr;
3263 
3264 	if (!nfserr)
3265 		nfserr = nfsd4_encode_stateid(xdr, &lock->lk_resp_stateid);
3266 	else if (nfserr == nfserr_denied)
3267 		nfserr = nfsd4_encode_lock_denied(xdr, &lock->lk_denied);
3268 
3269 	return nfserr;
3270 }
3271 
3272 static __be32
3273 nfsd4_encode_lockt(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_lockt *lockt)
3274 {
3275 	struct xdr_stream *xdr = &resp->xdr;
3276 
3277 	if (nfserr == nfserr_denied)
3278 		nfsd4_encode_lock_denied(xdr, &lockt->lt_denied);
3279 	return nfserr;
3280 }
3281 
3282 static __be32
3283 nfsd4_encode_locku(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_locku *locku)
3284 {
3285 	struct xdr_stream *xdr = &resp->xdr;
3286 
3287 	return nfsd4_encode_stateid(xdr, &locku->lu_stateid);
3288 }
3289 
3290 
3291 static __be32
3292 nfsd4_encode_link(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_link *link)
3293 {
3294 	struct xdr_stream *xdr = &resp->xdr;
3295 	__be32 *p;
3296 
3297 	p = xdr_reserve_space(xdr, 20);
3298 	if (!p)
3299 		return nfserr_resource;
3300 	p = encode_cinfo(p, &link->li_cinfo);
3301 	return 0;
3302 }
3303 
3304 
3305 static __be32
3306 nfsd4_encode_open(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_open *open)
3307 {
3308 	struct xdr_stream *xdr = &resp->xdr;
3309 	__be32 *p;
3310 
3311 	nfserr = nfsd4_encode_stateid(xdr, &open->op_stateid);
3312 	if (nfserr)
3313 		return nfserr;
3314 	p = xdr_reserve_space(xdr, 24);
3315 	if (!p)
3316 		return nfserr_resource;
3317 	p = encode_cinfo(p, &open->op_cinfo);
3318 	*p++ = cpu_to_be32(open->op_rflags);
3319 
3320 	nfserr = nfsd4_encode_bitmap(xdr, open->op_bmval[0], open->op_bmval[1],
3321 					open->op_bmval[2]);
3322 	if (nfserr)
3323 		return nfserr;
3324 
3325 	p = xdr_reserve_space(xdr, 4);
3326 	if (!p)
3327 		return nfserr_resource;
3328 
3329 	*p++ = cpu_to_be32(open->op_delegate_type);
3330 	switch (open->op_delegate_type) {
3331 	case NFS4_OPEN_DELEGATE_NONE:
3332 		break;
3333 	case NFS4_OPEN_DELEGATE_READ:
3334 		nfserr = nfsd4_encode_stateid(xdr, &open->op_delegate_stateid);
3335 		if (nfserr)
3336 			return nfserr;
3337 		p = xdr_reserve_space(xdr, 20);
3338 		if (!p)
3339 			return nfserr_resource;
3340 		*p++ = cpu_to_be32(open->op_recall);
3341 
3342 		/*
3343 		 * TODO: ACE's in delegations
3344 		 */
3345 		*p++ = cpu_to_be32(NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE);
3346 		*p++ = cpu_to_be32(0);
3347 		*p++ = cpu_to_be32(0);
3348 		*p++ = cpu_to_be32(0);   /* XXX: is NULL principal ok? */
3349 		break;
3350 	case NFS4_OPEN_DELEGATE_WRITE:
3351 		nfserr = nfsd4_encode_stateid(xdr, &open->op_delegate_stateid);
3352 		if (nfserr)
3353 			return nfserr;
3354 		p = xdr_reserve_space(xdr, 32);
3355 		if (!p)
3356 			return nfserr_resource;
3357 		*p++ = cpu_to_be32(0);
3358 
3359 		/*
3360 		 * TODO: space_limit's in delegations
3361 		 */
3362 		*p++ = cpu_to_be32(NFS4_LIMIT_SIZE);
3363 		*p++ = cpu_to_be32(~(u32)0);
3364 		*p++ = cpu_to_be32(~(u32)0);
3365 
3366 		/*
3367 		 * TODO: ACE's in delegations
3368 		 */
3369 		*p++ = cpu_to_be32(NFS4_ACE_ACCESS_ALLOWED_ACE_TYPE);
3370 		*p++ = cpu_to_be32(0);
3371 		*p++ = cpu_to_be32(0);
3372 		*p++ = cpu_to_be32(0);   /* XXX: is NULL principal ok? */
3373 		break;
3374 	case NFS4_OPEN_DELEGATE_NONE_EXT: /* 4.1 */
3375 		switch (open->op_why_no_deleg) {
3376 		case WND4_CONTENTION:
3377 		case WND4_RESOURCE:
3378 			p = xdr_reserve_space(xdr, 8);
3379 			if (!p)
3380 				return nfserr_resource;
3381 			*p++ = cpu_to_be32(open->op_why_no_deleg);
3382 			/* deleg signaling not supported yet: */
3383 			*p++ = cpu_to_be32(0);
3384 			break;
3385 		default:
3386 			p = xdr_reserve_space(xdr, 4);
3387 			if (!p)
3388 				return nfserr_resource;
3389 			*p++ = cpu_to_be32(open->op_why_no_deleg);
3390 		}
3391 		break;
3392 	default:
3393 		BUG();
3394 	}
3395 	/* XXX save filehandle here */
3396 	return 0;
3397 }
3398 
3399 static __be32
3400 nfsd4_encode_open_confirm(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_open_confirm *oc)
3401 {
3402 	struct xdr_stream *xdr = &resp->xdr;
3403 
3404 	return nfsd4_encode_stateid(xdr, &oc->oc_resp_stateid);
3405 }
3406 
3407 static __be32
3408 nfsd4_encode_open_downgrade(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_open_downgrade *od)
3409 {
3410 	struct xdr_stream *xdr = &resp->xdr;
3411 
3412 	return nfsd4_encode_stateid(xdr, &od->od_stateid);
3413 }
3414 
3415 static __be32 nfsd4_encode_splice_read(
3416 				struct nfsd4_compoundres *resp,
3417 				struct nfsd4_read *read,
3418 				struct file *file, unsigned long maxcount)
3419 {
3420 	struct xdr_stream *xdr = &resp->xdr;
3421 	struct xdr_buf *buf = xdr->buf;
3422 	u32 eof;
3423 	long len;
3424 	int space_left;
3425 	__be32 nfserr;
3426 	__be32 *p = xdr->p - 2;
3427 
3428 	/* Make sure there will be room for padding if needed */
3429 	if (xdr->end - xdr->p < 1)
3430 		return nfserr_resource;
3431 
3432 	len = maxcount;
3433 	nfserr = nfsd_splice_read(read->rd_rqstp, read->rd_fhp,
3434 				  file, read->rd_offset, &maxcount);
3435 	read->rd_length = maxcount;
3436 	if (nfserr) {
3437 		/*
3438 		 * nfsd_splice_actor may have already messed with the
3439 		 * page length; reset it so as not to confuse
3440 		 * xdr_truncate_encode:
3441 		 */
3442 		buf->page_len = 0;
3443 		return nfserr;
3444 	}
3445 
3446 	eof = nfsd_eof_on_read(len, maxcount, read->rd_offset,
3447 				d_inode(read->rd_fhp->fh_dentry)->i_size);
3448 
3449 	*(p++) = htonl(eof);
3450 	*(p++) = htonl(maxcount);
3451 
3452 	buf->page_len = maxcount;
3453 	buf->len += maxcount;
3454 	xdr->page_ptr += (buf->page_base + maxcount + PAGE_SIZE - 1)
3455 							/ PAGE_SIZE;
3456 
3457 	/* Use rest of head for padding and remaining ops: */
3458 	buf->tail[0].iov_base = xdr->p;
3459 	buf->tail[0].iov_len = 0;
3460 	xdr->iov = buf->tail;
3461 	if (maxcount&3) {
3462 		int pad = 4 - (maxcount&3);
3463 
3464 		*(xdr->p++) = 0;
3465 
3466 		buf->tail[0].iov_base += maxcount&3;
3467 		buf->tail[0].iov_len = pad;
3468 		buf->len += pad;
3469 	}
3470 
3471 	space_left = min_t(int, (void *)xdr->end - (void *)xdr->p,
3472 				buf->buflen - buf->len);
3473 	buf->buflen = buf->len + space_left;
3474 	xdr->end = (__be32 *)((void *)xdr->end + space_left);
3475 
3476 	return 0;
3477 }
3478 
3479 static __be32 nfsd4_encode_readv(struct nfsd4_compoundres *resp,
3480 				 struct nfsd4_read *read,
3481 				 struct file *file, unsigned long maxcount)
3482 {
3483 	struct xdr_stream *xdr = &resp->xdr;
3484 	u32 eof;
3485 	int v;
3486 	int starting_len = xdr->buf->len - 8;
3487 	long len;
3488 	int thislen;
3489 	__be32 nfserr;
3490 	__be32 tmp;
3491 	__be32 *p;
3492 	u32 zzz = 0;
3493 	int pad;
3494 
3495 	len = maxcount;
3496 	v = 0;
3497 
3498 	thislen = min_t(long, len, ((void *)xdr->end - (void *)xdr->p));
3499 	p = xdr_reserve_space(xdr, (thislen+3)&~3);
3500 	WARN_ON_ONCE(!p);
3501 	resp->rqstp->rq_vec[v].iov_base = p;
3502 	resp->rqstp->rq_vec[v].iov_len = thislen;
3503 	v++;
3504 	len -= thislen;
3505 
3506 	while (len) {
3507 		thislen = min_t(long, len, PAGE_SIZE);
3508 		p = xdr_reserve_space(xdr, (thislen+3)&~3);
3509 		WARN_ON_ONCE(!p);
3510 		resp->rqstp->rq_vec[v].iov_base = p;
3511 		resp->rqstp->rq_vec[v].iov_len = thislen;
3512 		v++;
3513 		len -= thislen;
3514 	}
3515 	read->rd_vlen = v;
3516 
3517 	len = maxcount;
3518 	nfserr = nfsd_readv(resp->rqstp, read->rd_fhp, file, read->rd_offset,
3519 			    resp->rqstp->rq_vec, read->rd_vlen, &maxcount);
3520 	read->rd_length = maxcount;
3521 	if (nfserr)
3522 		return nfserr;
3523 	xdr_truncate_encode(xdr, starting_len + 8 + ((maxcount+3)&~3));
3524 
3525 	eof = nfsd_eof_on_read(len, maxcount, read->rd_offset,
3526 				d_inode(read->rd_fhp->fh_dentry)->i_size);
3527 
3528 	tmp = htonl(eof);
3529 	write_bytes_to_xdr_buf(xdr->buf, starting_len    , &tmp, 4);
3530 	tmp = htonl(maxcount);
3531 	write_bytes_to_xdr_buf(xdr->buf, starting_len + 4, &tmp, 4);
3532 
3533 	pad = (maxcount&3) ? 4 - (maxcount&3) : 0;
3534 	write_bytes_to_xdr_buf(xdr->buf, starting_len + 8 + maxcount,
3535 								&zzz, pad);
3536 	return 0;
3537 
3538 }
3539 
3540 static __be32
3541 nfsd4_encode_read(struct nfsd4_compoundres *resp, __be32 nfserr,
3542 		  struct nfsd4_read *read)
3543 {
3544 	unsigned long maxcount;
3545 	struct xdr_stream *xdr = &resp->xdr;
3546 	struct file *file = read->rd_filp;
3547 	int starting_len = xdr->buf->len;
3548 	struct raparms *ra = NULL;
3549 	__be32 *p;
3550 
3551 	p = xdr_reserve_space(xdr, 8); /* eof flag and byte count */
3552 	if (!p) {
3553 		WARN_ON_ONCE(test_bit(RQ_SPLICE_OK, &resp->rqstp->rq_flags));
3554 		return nfserr_resource;
3555 	}
3556 	if (resp->xdr.buf->page_len &&
3557 	    test_bit(RQ_SPLICE_OK, &resp->rqstp->rq_flags)) {
3558 		WARN_ON_ONCE(1);
3559 		return nfserr_resource;
3560 	}
3561 	xdr_commit_encode(xdr);
3562 
3563 	maxcount = svc_max_payload(resp->rqstp);
3564 	maxcount = min_t(unsigned long, maxcount,
3565 			 (xdr->buf->buflen - xdr->buf->len));
3566 	maxcount = min_t(unsigned long, maxcount, read->rd_length);
3567 
3568 	if (read->rd_tmp_file)
3569 		ra = nfsd_init_raparms(file);
3570 
3571 	if (file->f_op->splice_read &&
3572 	    test_bit(RQ_SPLICE_OK, &resp->rqstp->rq_flags))
3573 		nfserr = nfsd4_encode_splice_read(resp, read, file, maxcount);
3574 	else
3575 		nfserr = nfsd4_encode_readv(resp, read, file, maxcount);
3576 
3577 	if (ra)
3578 		nfsd_put_raparams(file, ra);
3579 
3580 	if (nfserr)
3581 		xdr_truncate_encode(xdr, starting_len);
3582 
3583 	return nfserr;
3584 }
3585 
3586 static __be32
3587 nfsd4_encode_readlink(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_readlink *readlink)
3588 {
3589 	int maxcount;
3590 	__be32 wire_count;
3591 	int zero = 0;
3592 	struct xdr_stream *xdr = &resp->xdr;
3593 	int length_offset = xdr->buf->len;
3594 	__be32 *p;
3595 
3596 	p = xdr_reserve_space(xdr, 4);
3597 	if (!p)
3598 		return nfserr_resource;
3599 	maxcount = PAGE_SIZE;
3600 
3601 	p = xdr_reserve_space(xdr, maxcount);
3602 	if (!p)
3603 		return nfserr_resource;
3604 	/*
3605 	 * XXX: By default, vfs_readlink() will truncate symlinks if they
3606 	 * would overflow the buffer.  Is this kosher in NFSv4?  If not, one
3607 	 * easy fix is: if vfs_readlink() precisely fills the buffer, assume
3608 	 * that truncation occurred, and return NFS4ERR_RESOURCE.
3609 	 */
3610 	nfserr = nfsd_readlink(readlink->rl_rqstp, readlink->rl_fhp,
3611 						(char *)p, &maxcount);
3612 	if (nfserr == nfserr_isdir)
3613 		nfserr = nfserr_inval;
3614 	if (nfserr) {
3615 		xdr_truncate_encode(xdr, length_offset);
3616 		return nfserr;
3617 	}
3618 
3619 	wire_count = htonl(maxcount);
3620 	write_bytes_to_xdr_buf(xdr->buf, length_offset, &wire_count, 4);
3621 	xdr_truncate_encode(xdr, length_offset + 4 + ALIGN(maxcount, 4));
3622 	if (maxcount & 3)
3623 		write_bytes_to_xdr_buf(xdr->buf, length_offset + 4 + maxcount,
3624 						&zero, 4 - (maxcount&3));
3625 	return 0;
3626 }
3627 
3628 static __be32
3629 nfsd4_encode_readdir(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_readdir *readdir)
3630 {
3631 	int maxcount;
3632 	int bytes_left;
3633 	loff_t offset;
3634 	__be64 wire_offset;
3635 	struct xdr_stream *xdr = &resp->xdr;
3636 	int starting_len = xdr->buf->len;
3637 	__be32 *p;
3638 
3639 	p = xdr_reserve_space(xdr, NFS4_VERIFIER_SIZE);
3640 	if (!p)
3641 		return nfserr_resource;
3642 
3643 	/* XXX: Following NFSv3, we ignore the READDIR verifier for now. */
3644 	*p++ = cpu_to_be32(0);
3645 	*p++ = cpu_to_be32(0);
3646 	resp->xdr.buf->head[0].iov_len = ((char *)resp->xdr.p)
3647 				- (char *)resp->xdr.buf->head[0].iov_base;
3648 
3649 	/*
3650 	 * Number of bytes left for directory entries allowing for the
3651 	 * final 8 bytes of the readdir and a following failed op:
3652 	 */
3653 	bytes_left = xdr->buf->buflen - xdr->buf->len
3654 			- COMPOUND_ERR_SLACK_SPACE - 8;
3655 	if (bytes_left < 0) {
3656 		nfserr = nfserr_resource;
3657 		goto err_no_verf;
3658 	}
3659 	maxcount = svc_max_payload(resp->rqstp);
3660 	maxcount = min_t(u32, readdir->rd_maxcount, maxcount);
3661 	/*
3662 	 * Note the rfc defines rd_maxcount as the size of the
3663 	 * READDIR4resok structure, which includes the verifier above
3664 	 * and the 8 bytes encoded at the end of this function:
3665 	 */
3666 	if (maxcount < 16) {
3667 		nfserr = nfserr_toosmall;
3668 		goto err_no_verf;
3669 	}
3670 	maxcount = min_t(int, maxcount-16, bytes_left);
3671 
3672 	/* RFC 3530 14.2.24 allows us to ignore dircount when it's 0: */
3673 	if (!readdir->rd_dircount)
3674 		readdir->rd_dircount = svc_max_payload(resp->rqstp);
3675 
3676 	readdir->xdr = xdr;
3677 	readdir->rd_maxcount = maxcount;
3678 	readdir->common.err = 0;
3679 	readdir->cookie_offset = 0;
3680 
3681 	offset = readdir->rd_cookie;
3682 	nfserr = nfsd_readdir(readdir->rd_rqstp, readdir->rd_fhp,
3683 			      &offset,
3684 			      &readdir->common, nfsd4_encode_dirent);
3685 	if (nfserr == nfs_ok &&
3686 	    readdir->common.err == nfserr_toosmall &&
3687 	    xdr->buf->len == starting_len + 8) {
3688 		/* nothing encoded; which limit did we hit?: */
3689 		if (maxcount - 16 < bytes_left)
3690 			/* It was the fault of rd_maxcount: */
3691 			nfserr = nfserr_toosmall;
3692 		else
3693 			/* We ran out of buffer space: */
3694 			nfserr = nfserr_resource;
3695 	}
3696 	if (nfserr)
3697 		goto err_no_verf;
3698 
3699 	if (readdir->cookie_offset) {
3700 		wire_offset = cpu_to_be64(offset);
3701 		write_bytes_to_xdr_buf(xdr->buf, readdir->cookie_offset,
3702 							&wire_offset, 8);
3703 	}
3704 
3705 	p = xdr_reserve_space(xdr, 8);
3706 	if (!p) {
3707 		WARN_ON_ONCE(1);
3708 		goto err_no_verf;
3709 	}
3710 	*p++ = 0;	/* no more entries */
3711 	*p++ = htonl(readdir->common.err == nfserr_eof);
3712 
3713 	return 0;
3714 err_no_verf:
3715 	xdr_truncate_encode(xdr, starting_len);
3716 	return nfserr;
3717 }
3718 
3719 static __be32
3720 nfsd4_encode_remove(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_remove *remove)
3721 {
3722 	struct xdr_stream *xdr = &resp->xdr;
3723 	__be32 *p;
3724 
3725 	p = xdr_reserve_space(xdr, 20);
3726 	if (!p)
3727 		return nfserr_resource;
3728 	p = encode_cinfo(p, &remove->rm_cinfo);
3729 	return 0;
3730 }
3731 
3732 static __be32
3733 nfsd4_encode_rename(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_rename *rename)
3734 {
3735 	struct xdr_stream *xdr = &resp->xdr;
3736 	__be32 *p;
3737 
3738 	p = xdr_reserve_space(xdr, 40);
3739 	if (!p)
3740 		return nfserr_resource;
3741 	p = encode_cinfo(p, &rename->rn_sinfo);
3742 	p = encode_cinfo(p, &rename->rn_tinfo);
3743 	return 0;
3744 }
3745 
3746 static __be32
3747 nfsd4_do_encode_secinfo(struct xdr_stream *xdr, struct svc_export *exp)
3748 {
3749 	u32 i, nflavs, supported;
3750 	struct exp_flavor_info *flavs;
3751 	struct exp_flavor_info def_flavs[2];
3752 	__be32 *p, *flavorsp;
3753 	static bool report = true;
3754 
3755 	if (exp->ex_nflavors) {
3756 		flavs = exp->ex_flavors;
3757 		nflavs = exp->ex_nflavors;
3758 	} else { /* Handling of some defaults in absence of real secinfo: */
3759 		flavs = def_flavs;
3760 		if (exp->ex_client->flavour->flavour == RPC_AUTH_UNIX) {
3761 			nflavs = 2;
3762 			flavs[0].pseudoflavor = RPC_AUTH_UNIX;
3763 			flavs[1].pseudoflavor = RPC_AUTH_NULL;
3764 		} else if (exp->ex_client->flavour->flavour == RPC_AUTH_GSS) {
3765 			nflavs = 1;
3766 			flavs[0].pseudoflavor
3767 					= svcauth_gss_flavor(exp->ex_client);
3768 		} else {
3769 			nflavs = 1;
3770 			flavs[0].pseudoflavor
3771 					= exp->ex_client->flavour->flavour;
3772 		}
3773 	}
3774 
3775 	supported = 0;
3776 	p = xdr_reserve_space(xdr, 4);
3777 	if (!p)
3778 		return nfserr_resource;
3779 	flavorsp = p++;		/* to be backfilled later */
3780 
3781 	for (i = 0; i < nflavs; i++) {
3782 		rpc_authflavor_t pf = flavs[i].pseudoflavor;
3783 		struct rpcsec_gss_info info;
3784 
3785 		if (rpcauth_get_gssinfo(pf, &info) == 0) {
3786 			supported++;
3787 			p = xdr_reserve_space(xdr, 4 + 4 +
3788 					      XDR_LEN(info.oid.len) + 4 + 4);
3789 			if (!p)
3790 				return nfserr_resource;
3791 			*p++ = cpu_to_be32(RPC_AUTH_GSS);
3792 			p = xdr_encode_opaque(p,  info.oid.data, info.oid.len);
3793 			*p++ = cpu_to_be32(info.qop);
3794 			*p++ = cpu_to_be32(info.service);
3795 		} else if (pf < RPC_AUTH_MAXFLAVOR) {
3796 			supported++;
3797 			p = xdr_reserve_space(xdr, 4);
3798 			if (!p)
3799 				return nfserr_resource;
3800 			*p++ = cpu_to_be32(pf);
3801 		} else {
3802 			if (report)
3803 				pr_warn("NFS: SECINFO: security flavor %u "
3804 					"is not supported\n", pf);
3805 		}
3806 	}
3807 
3808 	if (nflavs != supported)
3809 		report = false;
3810 	*flavorsp = htonl(supported);
3811 	return 0;
3812 }
3813 
3814 static __be32
3815 nfsd4_encode_secinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
3816 		     struct nfsd4_secinfo *secinfo)
3817 {
3818 	struct xdr_stream *xdr = &resp->xdr;
3819 
3820 	return nfsd4_do_encode_secinfo(xdr, secinfo->si_exp);
3821 }
3822 
3823 static __be32
3824 nfsd4_encode_secinfo_no_name(struct nfsd4_compoundres *resp, __be32 nfserr,
3825 		     struct nfsd4_secinfo_no_name *secinfo)
3826 {
3827 	struct xdr_stream *xdr = &resp->xdr;
3828 
3829 	return nfsd4_do_encode_secinfo(xdr, secinfo->sin_exp);
3830 }
3831 
3832 /*
3833  * The SETATTR encode routine is special -- it always encodes a bitmap,
3834  * regardless of the error status.
3835  */
3836 static __be32
3837 nfsd4_encode_setattr(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_setattr *setattr)
3838 {
3839 	struct xdr_stream *xdr = &resp->xdr;
3840 	__be32 *p;
3841 
3842 	p = xdr_reserve_space(xdr, 16);
3843 	if (!p)
3844 		return nfserr_resource;
3845 	if (nfserr) {
3846 		*p++ = cpu_to_be32(3);
3847 		*p++ = cpu_to_be32(0);
3848 		*p++ = cpu_to_be32(0);
3849 		*p++ = cpu_to_be32(0);
3850 	}
3851 	else {
3852 		*p++ = cpu_to_be32(3);
3853 		*p++ = cpu_to_be32(setattr->sa_bmval[0]);
3854 		*p++ = cpu_to_be32(setattr->sa_bmval[1]);
3855 		*p++ = cpu_to_be32(setattr->sa_bmval[2]);
3856 	}
3857 	return nfserr;
3858 }
3859 
3860 static __be32
3861 nfsd4_encode_setclientid(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_setclientid *scd)
3862 {
3863 	struct xdr_stream *xdr = &resp->xdr;
3864 	__be32 *p;
3865 
3866 	if (!nfserr) {
3867 		p = xdr_reserve_space(xdr, 8 + NFS4_VERIFIER_SIZE);
3868 		if (!p)
3869 			return nfserr_resource;
3870 		p = xdr_encode_opaque_fixed(p, &scd->se_clientid, 8);
3871 		p = xdr_encode_opaque_fixed(p, &scd->se_confirm,
3872 						NFS4_VERIFIER_SIZE);
3873 	}
3874 	else if (nfserr == nfserr_clid_inuse) {
3875 		p = xdr_reserve_space(xdr, 8);
3876 		if (!p)
3877 			return nfserr_resource;
3878 		*p++ = cpu_to_be32(0);
3879 		*p++ = cpu_to_be32(0);
3880 	}
3881 	return nfserr;
3882 }
3883 
3884 static __be32
3885 nfsd4_encode_write(struct nfsd4_compoundres *resp, __be32 nfserr, struct nfsd4_write *write)
3886 {
3887 	struct xdr_stream *xdr = &resp->xdr;
3888 	__be32 *p;
3889 
3890 	p = xdr_reserve_space(xdr, 16);
3891 	if (!p)
3892 		return nfserr_resource;
3893 	*p++ = cpu_to_be32(write->wr_bytes_written);
3894 	*p++ = cpu_to_be32(write->wr_how_written);
3895 	p = xdr_encode_opaque_fixed(p, write->wr_verifier.data,
3896 						NFS4_VERIFIER_SIZE);
3897 	return 0;
3898 }
3899 
3900 static __be32
3901 nfsd4_encode_exchange_id(struct nfsd4_compoundres *resp, __be32 nfserr,
3902 			 struct nfsd4_exchange_id *exid)
3903 {
3904 	struct xdr_stream *xdr = &resp->xdr;
3905 	__be32 *p;
3906 	char *major_id;
3907 	char *server_scope;
3908 	int major_id_sz;
3909 	int server_scope_sz;
3910 	uint64_t minor_id = 0;
3911 
3912 	major_id = utsname()->nodename;
3913 	major_id_sz = strlen(major_id);
3914 	server_scope = utsname()->nodename;
3915 	server_scope_sz = strlen(server_scope);
3916 
3917 	p = xdr_reserve_space(xdr,
3918 		8 /* eir_clientid */ +
3919 		4 /* eir_sequenceid */ +
3920 		4 /* eir_flags */ +
3921 		4 /* spr_how */);
3922 	if (!p)
3923 		return nfserr_resource;
3924 
3925 	p = xdr_encode_opaque_fixed(p, &exid->clientid, 8);
3926 	*p++ = cpu_to_be32(exid->seqid);
3927 	*p++ = cpu_to_be32(exid->flags);
3928 
3929 	*p++ = cpu_to_be32(exid->spa_how);
3930 
3931 	switch (exid->spa_how) {
3932 	case SP4_NONE:
3933 		break;
3934 	case SP4_MACH_CRED:
3935 		/* spo_must_enforce bitmap: */
3936 		nfserr = nfsd4_encode_bitmap(xdr,
3937 					exid->spo_must_enforce[0],
3938 					exid->spo_must_enforce[1],
3939 					exid->spo_must_enforce[2]);
3940 		if (nfserr)
3941 			return nfserr;
3942 		/* spo_must_allow bitmap: */
3943 		nfserr = nfsd4_encode_bitmap(xdr,
3944 					exid->spo_must_allow[0],
3945 					exid->spo_must_allow[1],
3946 					exid->spo_must_allow[2]);
3947 		if (nfserr)
3948 			return nfserr;
3949 		break;
3950 	default:
3951 		WARN_ON_ONCE(1);
3952 	}
3953 
3954 	p = xdr_reserve_space(xdr,
3955 		8 /* so_minor_id */ +
3956 		4 /* so_major_id.len */ +
3957 		(XDR_QUADLEN(major_id_sz) * 4) +
3958 		4 /* eir_server_scope.len */ +
3959 		(XDR_QUADLEN(server_scope_sz) * 4) +
3960 		4 /* eir_server_impl_id.count (0) */);
3961 	if (!p)
3962 		return nfserr_resource;
3963 
3964 	/* The server_owner struct */
3965 	p = xdr_encode_hyper(p, minor_id);      /* Minor id */
3966 	/* major id */
3967 	p = xdr_encode_opaque(p, major_id, major_id_sz);
3968 
3969 	/* Server scope */
3970 	p = xdr_encode_opaque(p, server_scope, server_scope_sz);
3971 
3972 	/* Implementation id */
3973 	*p++ = cpu_to_be32(0);	/* zero length nfs_impl_id4 array */
3974 	return 0;
3975 }
3976 
3977 static __be32
3978 nfsd4_encode_create_session(struct nfsd4_compoundres *resp, __be32 nfserr,
3979 			    struct nfsd4_create_session *sess)
3980 {
3981 	struct xdr_stream *xdr = &resp->xdr;
3982 	__be32 *p;
3983 
3984 	p = xdr_reserve_space(xdr, 24);
3985 	if (!p)
3986 		return nfserr_resource;
3987 	p = xdr_encode_opaque_fixed(p, sess->sessionid.data,
3988 					NFS4_MAX_SESSIONID_LEN);
3989 	*p++ = cpu_to_be32(sess->seqid);
3990 	*p++ = cpu_to_be32(sess->flags);
3991 
3992 	p = xdr_reserve_space(xdr, 28);
3993 	if (!p)
3994 		return nfserr_resource;
3995 	*p++ = cpu_to_be32(0); /* headerpadsz */
3996 	*p++ = cpu_to_be32(sess->fore_channel.maxreq_sz);
3997 	*p++ = cpu_to_be32(sess->fore_channel.maxresp_sz);
3998 	*p++ = cpu_to_be32(sess->fore_channel.maxresp_cached);
3999 	*p++ = cpu_to_be32(sess->fore_channel.maxops);
4000 	*p++ = cpu_to_be32(sess->fore_channel.maxreqs);
4001 	*p++ = cpu_to_be32(sess->fore_channel.nr_rdma_attrs);
4002 
4003 	if (sess->fore_channel.nr_rdma_attrs) {
4004 		p = xdr_reserve_space(xdr, 4);
4005 		if (!p)
4006 			return nfserr_resource;
4007 		*p++ = cpu_to_be32(sess->fore_channel.rdma_attrs);
4008 	}
4009 
4010 	p = xdr_reserve_space(xdr, 28);
4011 	if (!p)
4012 		return nfserr_resource;
4013 	*p++ = cpu_to_be32(0); /* headerpadsz */
4014 	*p++ = cpu_to_be32(sess->back_channel.maxreq_sz);
4015 	*p++ = cpu_to_be32(sess->back_channel.maxresp_sz);
4016 	*p++ = cpu_to_be32(sess->back_channel.maxresp_cached);
4017 	*p++ = cpu_to_be32(sess->back_channel.maxops);
4018 	*p++ = cpu_to_be32(sess->back_channel.maxreqs);
4019 	*p++ = cpu_to_be32(sess->back_channel.nr_rdma_attrs);
4020 
4021 	if (sess->back_channel.nr_rdma_attrs) {
4022 		p = xdr_reserve_space(xdr, 4);
4023 		if (!p)
4024 			return nfserr_resource;
4025 		*p++ = cpu_to_be32(sess->back_channel.rdma_attrs);
4026 	}
4027 	return 0;
4028 }
4029 
4030 static __be32
4031 nfsd4_encode_sequence(struct nfsd4_compoundres *resp, __be32 nfserr,
4032 		      struct nfsd4_sequence *seq)
4033 {
4034 	struct xdr_stream *xdr = &resp->xdr;
4035 	__be32 *p;
4036 
4037 	p = xdr_reserve_space(xdr, NFS4_MAX_SESSIONID_LEN + 20);
4038 	if (!p)
4039 		return nfserr_resource;
4040 	p = xdr_encode_opaque_fixed(p, seq->sessionid.data,
4041 					NFS4_MAX_SESSIONID_LEN);
4042 	*p++ = cpu_to_be32(seq->seqid);
4043 	*p++ = cpu_to_be32(seq->slotid);
4044 	/* Note slotid's are numbered from zero: */
4045 	*p++ = cpu_to_be32(seq->maxslots - 1); /* sr_highest_slotid */
4046 	*p++ = cpu_to_be32(seq->maxslots - 1); /* sr_target_highest_slotid */
4047 	*p++ = cpu_to_be32(seq->status_flags);
4048 
4049 	resp->cstate.data_offset = xdr->buf->len; /* DRC cache data pointer */
4050 	return 0;
4051 }
4052 
4053 static __be32
4054 nfsd4_encode_test_stateid(struct nfsd4_compoundres *resp, __be32 nfserr,
4055 			  struct nfsd4_test_stateid *test_stateid)
4056 {
4057 	struct xdr_stream *xdr = &resp->xdr;
4058 	struct nfsd4_test_stateid_id *stateid, *next;
4059 	__be32 *p;
4060 
4061 	p = xdr_reserve_space(xdr, 4 + (4 * test_stateid->ts_num_ids));
4062 	if (!p)
4063 		return nfserr_resource;
4064 	*p++ = htonl(test_stateid->ts_num_ids);
4065 
4066 	list_for_each_entry_safe(stateid, next, &test_stateid->ts_stateid_list, ts_id_list) {
4067 		*p++ = stateid->ts_id_status;
4068 	}
4069 
4070 	return 0;
4071 }
4072 
4073 #ifdef CONFIG_NFSD_PNFS
4074 static __be32
4075 nfsd4_encode_getdeviceinfo(struct nfsd4_compoundres *resp, __be32 nfserr,
4076 		struct nfsd4_getdeviceinfo *gdev)
4077 {
4078 	struct xdr_stream *xdr = &resp->xdr;
4079 	const struct nfsd4_layout_ops *ops;
4080 	u32 starting_len = xdr->buf->len, needed_len;
4081 	__be32 *p;
4082 
4083 	p = xdr_reserve_space(xdr, 4);
4084 	if (!p)
4085 		return nfserr_resource;
4086 
4087 	*p++ = cpu_to_be32(gdev->gd_layout_type);
4088 
4089 	/* If maxcount is 0 then just update notifications */
4090 	if (gdev->gd_maxcount != 0) {
4091 		ops = nfsd4_layout_ops[gdev->gd_layout_type];
4092 		nfserr = ops->encode_getdeviceinfo(xdr, gdev);
4093 		if (nfserr) {
4094 			/*
4095 			 * We don't bother to burden the layout drivers with
4096 			 * enforcing gd_maxcount, just tell the client to
4097 			 * come back with a bigger buffer if it's not enough.
4098 			 */
4099 			if (xdr->buf->len + 4 > gdev->gd_maxcount)
4100 				goto toosmall;
4101 			return nfserr;
4102 		}
4103 	}
4104 
4105 	if (gdev->gd_notify_types) {
4106 		p = xdr_reserve_space(xdr, 4 + 4);
4107 		if (!p)
4108 			return nfserr_resource;
4109 		*p++ = cpu_to_be32(1);			/* bitmap length */
4110 		*p++ = cpu_to_be32(gdev->gd_notify_types);
4111 	} else {
4112 		p = xdr_reserve_space(xdr, 4);
4113 		if (!p)
4114 			return nfserr_resource;
4115 		*p++ = 0;
4116 	}
4117 
4118 	return 0;
4119 toosmall:
4120 	dprintk("%s: maxcount too small\n", __func__);
4121 	needed_len = xdr->buf->len + 4 /* notifications */;
4122 	xdr_truncate_encode(xdr, starting_len);
4123 	p = xdr_reserve_space(xdr, 4);
4124 	if (!p)
4125 		return nfserr_resource;
4126 	*p++ = cpu_to_be32(needed_len);
4127 	return nfserr_toosmall;
4128 }
4129 
4130 static __be32
4131 nfsd4_encode_layoutget(struct nfsd4_compoundres *resp, __be32 nfserr,
4132 		struct nfsd4_layoutget *lgp)
4133 {
4134 	struct xdr_stream *xdr = &resp->xdr;
4135 	const struct nfsd4_layout_ops *ops;
4136 	__be32 *p;
4137 
4138 	p = xdr_reserve_space(xdr, 36 + sizeof(stateid_opaque_t));
4139 	if (!p)
4140 		return nfserr_resource;
4141 
4142 	*p++ = cpu_to_be32(1);	/* we always set return-on-close */
4143 	*p++ = cpu_to_be32(lgp->lg_sid.si_generation);
4144 	p = xdr_encode_opaque_fixed(p, &lgp->lg_sid.si_opaque,
4145 				    sizeof(stateid_opaque_t));
4146 
4147 	*p++ = cpu_to_be32(1);	/* we always return a single layout */
4148 	p = xdr_encode_hyper(p, lgp->lg_seg.offset);
4149 	p = xdr_encode_hyper(p, lgp->lg_seg.length);
4150 	*p++ = cpu_to_be32(lgp->lg_seg.iomode);
4151 	*p++ = cpu_to_be32(lgp->lg_layout_type);
4152 
4153 	ops = nfsd4_layout_ops[lgp->lg_layout_type];
4154 	return ops->encode_layoutget(xdr, lgp);
4155 }
4156 
4157 static __be32
4158 nfsd4_encode_layoutcommit(struct nfsd4_compoundres *resp, __be32 nfserr,
4159 			  struct nfsd4_layoutcommit *lcp)
4160 {
4161 	struct xdr_stream *xdr = &resp->xdr;
4162 	__be32 *p;
4163 
4164 	p = xdr_reserve_space(xdr, 4);
4165 	if (!p)
4166 		return nfserr_resource;
4167 	*p++ = cpu_to_be32(lcp->lc_size_chg);
4168 	if (lcp->lc_size_chg) {
4169 		p = xdr_reserve_space(xdr, 8);
4170 		if (!p)
4171 			return nfserr_resource;
4172 		p = xdr_encode_hyper(p, lcp->lc_newsize);
4173 	}
4174 
4175 	return 0;
4176 }
4177 
4178 static __be32
4179 nfsd4_encode_layoutreturn(struct nfsd4_compoundres *resp, __be32 nfserr,
4180 		struct nfsd4_layoutreturn *lrp)
4181 {
4182 	struct xdr_stream *xdr = &resp->xdr;
4183 	__be32 *p;
4184 
4185 	p = xdr_reserve_space(xdr, 4);
4186 	if (!p)
4187 		return nfserr_resource;
4188 	*p++ = cpu_to_be32(lrp->lrs_present);
4189 	if (lrp->lrs_present)
4190 		return nfsd4_encode_stateid(xdr, &lrp->lr_sid);
4191 	return 0;
4192 }
4193 #endif /* CONFIG_NFSD_PNFS */
4194 
4195 static __be32
4196 nfsd42_encode_write_res(struct nfsd4_compoundres *resp, struct nfsd42_write_res *write)
4197 {
4198 	__be32 *p;
4199 
4200 	p = xdr_reserve_space(&resp->xdr, 4 + 8 + 4 + NFS4_VERIFIER_SIZE);
4201 	if (!p)
4202 		return nfserr_resource;
4203 
4204 	*p++ = cpu_to_be32(0);
4205 	p = xdr_encode_hyper(p, write->wr_bytes_written);
4206 	*p++ = cpu_to_be32(write->wr_stable_how);
4207 	p = xdr_encode_opaque_fixed(p, write->wr_verifier.data,
4208 				    NFS4_VERIFIER_SIZE);
4209 	return nfs_ok;
4210 }
4211 
4212 static __be32
4213 nfsd4_encode_copy(struct nfsd4_compoundres *resp, __be32 nfserr,
4214 		  struct nfsd4_copy *copy)
4215 {
4216 	__be32 *p;
4217 
4218 	nfserr = nfsd42_encode_write_res(resp, &copy->cp_res);
4219 	if (nfserr)
4220 		return nfserr;
4221 
4222 	p = xdr_reserve_space(&resp->xdr, 4 + 4);
4223 	*p++ = xdr_one; /* cr_consecutive */
4224 	*p++ = cpu_to_be32(copy->cp_synchronous);
4225 	return 0;
4226 }
4227 
4228 static __be32
4229 nfsd4_encode_seek(struct nfsd4_compoundres *resp, __be32 nfserr,
4230 		  struct nfsd4_seek *seek)
4231 {
4232 	__be32 *p;
4233 
4234 	p = xdr_reserve_space(&resp->xdr, 4 + 8);
4235 	*p++ = cpu_to_be32(seek->seek_eof);
4236 	p = xdr_encode_hyper(p, seek->seek_pos);
4237 
4238 	return 0;
4239 }
4240 
4241 static __be32
4242 nfsd4_encode_noop(struct nfsd4_compoundres *resp, __be32 nfserr, void *p)
4243 {
4244 	return nfserr;
4245 }
4246 
4247 typedef __be32(* nfsd4_enc)(struct nfsd4_compoundres *, __be32, void *);
4248 
4249 /*
4250  * Note: nfsd4_enc_ops vector is shared for v4.0 and v4.1
4251  * since we don't need to filter out obsolete ops as this is
4252  * done in the decoding phase.
4253  */
4254 static const nfsd4_enc nfsd4_enc_ops[] = {
4255 	[OP_ACCESS]		= (nfsd4_enc)nfsd4_encode_access,
4256 	[OP_CLOSE]		= (nfsd4_enc)nfsd4_encode_close,
4257 	[OP_COMMIT]		= (nfsd4_enc)nfsd4_encode_commit,
4258 	[OP_CREATE]		= (nfsd4_enc)nfsd4_encode_create,
4259 	[OP_DELEGPURGE]		= (nfsd4_enc)nfsd4_encode_noop,
4260 	[OP_DELEGRETURN]	= (nfsd4_enc)nfsd4_encode_noop,
4261 	[OP_GETATTR]		= (nfsd4_enc)nfsd4_encode_getattr,
4262 	[OP_GETFH]		= (nfsd4_enc)nfsd4_encode_getfh,
4263 	[OP_LINK]		= (nfsd4_enc)nfsd4_encode_link,
4264 	[OP_LOCK]		= (nfsd4_enc)nfsd4_encode_lock,
4265 	[OP_LOCKT]		= (nfsd4_enc)nfsd4_encode_lockt,
4266 	[OP_LOCKU]		= (nfsd4_enc)nfsd4_encode_locku,
4267 	[OP_LOOKUP]		= (nfsd4_enc)nfsd4_encode_noop,
4268 	[OP_LOOKUPP]		= (nfsd4_enc)nfsd4_encode_noop,
4269 	[OP_NVERIFY]		= (nfsd4_enc)nfsd4_encode_noop,
4270 	[OP_OPEN]		= (nfsd4_enc)nfsd4_encode_open,
4271 	[OP_OPENATTR]		= (nfsd4_enc)nfsd4_encode_noop,
4272 	[OP_OPEN_CONFIRM]	= (nfsd4_enc)nfsd4_encode_open_confirm,
4273 	[OP_OPEN_DOWNGRADE]	= (nfsd4_enc)nfsd4_encode_open_downgrade,
4274 	[OP_PUTFH]		= (nfsd4_enc)nfsd4_encode_noop,
4275 	[OP_PUTPUBFH]		= (nfsd4_enc)nfsd4_encode_noop,
4276 	[OP_PUTROOTFH]		= (nfsd4_enc)nfsd4_encode_noop,
4277 	[OP_READ]		= (nfsd4_enc)nfsd4_encode_read,
4278 	[OP_READDIR]		= (nfsd4_enc)nfsd4_encode_readdir,
4279 	[OP_READLINK]		= (nfsd4_enc)nfsd4_encode_readlink,
4280 	[OP_REMOVE]		= (nfsd4_enc)nfsd4_encode_remove,
4281 	[OP_RENAME]		= (nfsd4_enc)nfsd4_encode_rename,
4282 	[OP_RENEW]		= (nfsd4_enc)nfsd4_encode_noop,
4283 	[OP_RESTOREFH]		= (nfsd4_enc)nfsd4_encode_noop,
4284 	[OP_SAVEFH]		= (nfsd4_enc)nfsd4_encode_noop,
4285 	[OP_SECINFO]		= (nfsd4_enc)nfsd4_encode_secinfo,
4286 	[OP_SETATTR]		= (nfsd4_enc)nfsd4_encode_setattr,
4287 	[OP_SETCLIENTID]	= (nfsd4_enc)nfsd4_encode_setclientid,
4288 	[OP_SETCLIENTID_CONFIRM] = (nfsd4_enc)nfsd4_encode_noop,
4289 	[OP_VERIFY]		= (nfsd4_enc)nfsd4_encode_noop,
4290 	[OP_WRITE]		= (nfsd4_enc)nfsd4_encode_write,
4291 	[OP_RELEASE_LOCKOWNER]	= (nfsd4_enc)nfsd4_encode_noop,
4292 
4293 	/* NFSv4.1 operations */
4294 	[OP_BACKCHANNEL_CTL]	= (nfsd4_enc)nfsd4_encode_noop,
4295 	[OP_BIND_CONN_TO_SESSION] = (nfsd4_enc)nfsd4_encode_bind_conn_to_session,
4296 	[OP_EXCHANGE_ID]	= (nfsd4_enc)nfsd4_encode_exchange_id,
4297 	[OP_CREATE_SESSION]	= (nfsd4_enc)nfsd4_encode_create_session,
4298 	[OP_DESTROY_SESSION]	= (nfsd4_enc)nfsd4_encode_noop,
4299 	[OP_FREE_STATEID]	= (nfsd4_enc)nfsd4_encode_noop,
4300 	[OP_GET_DIR_DELEGATION]	= (nfsd4_enc)nfsd4_encode_noop,
4301 #ifdef CONFIG_NFSD_PNFS
4302 	[OP_GETDEVICEINFO]	= (nfsd4_enc)nfsd4_encode_getdeviceinfo,
4303 	[OP_GETDEVICELIST]	= (nfsd4_enc)nfsd4_encode_noop,
4304 	[OP_LAYOUTCOMMIT]	= (nfsd4_enc)nfsd4_encode_layoutcommit,
4305 	[OP_LAYOUTGET]		= (nfsd4_enc)nfsd4_encode_layoutget,
4306 	[OP_LAYOUTRETURN]	= (nfsd4_enc)nfsd4_encode_layoutreturn,
4307 #else
4308 	[OP_GETDEVICEINFO]	= (nfsd4_enc)nfsd4_encode_noop,
4309 	[OP_GETDEVICELIST]	= (nfsd4_enc)nfsd4_encode_noop,
4310 	[OP_LAYOUTCOMMIT]	= (nfsd4_enc)nfsd4_encode_noop,
4311 	[OP_LAYOUTGET]		= (nfsd4_enc)nfsd4_encode_noop,
4312 	[OP_LAYOUTRETURN]	= (nfsd4_enc)nfsd4_encode_noop,
4313 #endif
4314 	[OP_SECINFO_NO_NAME]	= (nfsd4_enc)nfsd4_encode_secinfo_no_name,
4315 	[OP_SEQUENCE]		= (nfsd4_enc)nfsd4_encode_sequence,
4316 	[OP_SET_SSV]		= (nfsd4_enc)nfsd4_encode_noop,
4317 	[OP_TEST_STATEID]	= (nfsd4_enc)nfsd4_encode_test_stateid,
4318 	[OP_WANT_DELEGATION]	= (nfsd4_enc)nfsd4_encode_noop,
4319 	[OP_DESTROY_CLIENTID]	= (nfsd4_enc)nfsd4_encode_noop,
4320 	[OP_RECLAIM_COMPLETE]	= (nfsd4_enc)nfsd4_encode_noop,
4321 
4322 	/* NFSv4.2 operations */
4323 	[OP_ALLOCATE]		= (nfsd4_enc)nfsd4_encode_noop,
4324 	[OP_COPY]		= (nfsd4_enc)nfsd4_encode_copy,
4325 	[OP_COPY_NOTIFY]	= (nfsd4_enc)nfsd4_encode_noop,
4326 	[OP_DEALLOCATE]		= (nfsd4_enc)nfsd4_encode_noop,
4327 	[OP_IO_ADVISE]		= (nfsd4_enc)nfsd4_encode_noop,
4328 	[OP_LAYOUTERROR]	= (nfsd4_enc)nfsd4_encode_noop,
4329 	[OP_LAYOUTSTATS]	= (nfsd4_enc)nfsd4_encode_noop,
4330 	[OP_OFFLOAD_CANCEL]	= (nfsd4_enc)nfsd4_encode_noop,
4331 	[OP_OFFLOAD_STATUS]	= (nfsd4_enc)nfsd4_encode_noop,
4332 	[OP_READ_PLUS]		= (nfsd4_enc)nfsd4_encode_noop,
4333 	[OP_SEEK]		= (nfsd4_enc)nfsd4_encode_seek,
4334 	[OP_WRITE_SAME]		= (nfsd4_enc)nfsd4_encode_noop,
4335 	[OP_CLONE]		= (nfsd4_enc)nfsd4_encode_noop,
4336 };
4337 
4338 /*
4339  * Calculate whether we still have space to encode repsize bytes.
4340  * There are two considerations:
4341  *     - For NFS versions >=4.1, the size of the reply must stay within
4342  *       session limits
4343  *     - For all NFS versions, we must stay within limited preallocated
4344  *       buffer space.
4345  *
4346  * This is called before the operation is processed, so can only provide
4347  * an upper estimate.  For some nonidempotent operations (such as
4348  * getattr), it's not necessarily a problem if that estimate is wrong,
4349  * as we can fail it after processing without significant side effects.
4350  */
4351 __be32 nfsd4_check_resp_size(struct nfsd4_compoundres *resp, u32 respsize)
4352 {
4353 	struct xdr_buf *buf = &resp->rqstp->rq_res;
4354 	struct nfsd4_slot *slot = resp->cstate.slot;
4355 
4356 	if (buf->len + respsize <= buf->buflen)
4357 		return nfs_ok;
4358 	if (!nfsd4_has_session(&resp->cstate))
4359 		return nfserr_resource;
4360 	if (slot->sl_flags & NFSD4_SLOT_CACHETHIS) {
4361 		WARN_ON_ONCE(1);
4362 		return nfserr_rep_too_big_to_cache;
4363 	}
4364 	return nfserr_rep_too_big;
4365 }
4366 
4367 void
4368 nfsd4_encode_operation(struct nfsd4_compoundres *resp, struct nfsd4_op *op)
4369 {
4370 	struct xdr_stream *xdr = &resp->xdr;
4371 	struct nfs4_stateowner *so = resp->cstate.replay_owner;
4372 	struct svc_rqst *rqstp = resp->rqstp;
4373 	const struct nfsd4_operation *opdesc = op->opdesc;
4374 	int post_err_offset;
4375 	nfsd4_enc encoder;
4376 	__be32 *p;
4377 
4378 	p = xdr_reserve_space(xdr, 8);
4379 	if (!p) {
4380 		WARN_ON_ONCE(1);
4381 		return;
4382 	}
4383 	*p++ = cpu_to_be32(op->opnum);
4384 	post_err_offset = xdr->buf->len;
4385 
4386 	if (op->opnum == OP_ILLEGAL)
4387 		goto status;
4388 	if (op->status && opdesc &&
4389 			!(opdesc->op_flags & OP_NONTRIVIAL_ERROR_ENCODE))
4390 		goto status;
4391 	BUG_ON(op->opnum < 0 || op->opnum >= ARRAY_SIZE(nfsd4_enc_ops) ||
4392 	       !nfsd4_enc_ops[op->opnum]);
4393 	encoder = nfsd4_enc_ops[op->opnum];
4394 	op->status = encoder(resp, op->status, &op->u);
4395 	if (opdesc && opdesc->op_release)
4396 		opdesc->op_release(&op->u);
4397 	xdr_commit_encode(xdr);
4398 
4399 	/* nfsd4_check_resp_size guarantees enough room for error status */
4400 	if (!op->status) {
4401 		int space_needed = 0;
4402 		if (!nfsd4_last_compound_op(rqstp))
4403 			space_needed = COMPOUND_ERR_SLACK_SPACE;
4404 		op->status = nfsd4_check_resp_size(resp, space_needed);
4405 	}
4406 	if (op->status == nfserr_resource && nfsd4_has_session(&resp->cstate)) {
4407 		struct nfsd4_slot *slot = resp->cstate.slot;
4408 
4409 		if (slot->sl_flags & NFSD4_SLOT_CACHETHIS)
4410 			op->status = nfserr_rep_too_big_to_cache;
4411 		else
4412 			op->status = nfserr_rep_too_big;
4413 	}
4414 	if (op->status == nfserr_resource ||
4415 	    op->status == nfserr_rep_too_big ||
4416 	    op->status == nfserr_rep_too_big_to_cache) {
4417 		/*
4418 		 * The operation may have already been encoded or
4419 		 * partially encoded.  No op returns anything additional
4420 		 * in the case of one of these three errors, so we can
4421 		 * just truncate back to after the status.  But it's a
4422 		 * bug if we had to do this on a non-idempotent op:
4423 		 */
4424 		warn_on_nonidempotent_op(op);
4425 		xdr_truncate_encode(xdr, post_err_offset);
4426 	}
4427 	if (so) {
4428 		int len = xdr->buf->len - post_err_offset;
4429 
4430 		so->so_replay.rp_status = op->status;
4431 		so->so_replay.rp_buflen = len;
4432 		read_bytes_from_xdr_buf(xdr->buf, post_err_offset,
4433 						so->so_replay.rp_buf, len);
4434 	}
4435 status:
4436 	/* Note that op->status is already in network byte order: */
4437 	write_bytes_to_xdr_buf(xdr->buf, post_err_offset - 4, &op->status, 4);
4438 }
4439 
4440 /*
4441  * Encode the reply stored in the stateowner reply cache
4442  *
4443  * XDR note: do not encode rp->rp_buflen: the buffer contains the
4444  * previously sent already encoded operation.
4445  */
4446 void
4447 nfsd4_encode_replay(struct xdr_stream *xdr, struct nfsd4_op *op)
4448 {
4449 	__be32 *p;
4450 	struct nfs4_replay *rp = op->replay;
4451 
4452 	BUG_ON(!rp);
4453 
4454 	p = xdr_reserve_space(xdr, 8 + rp->rp_buflen);
4455 	if (!p) {
4456 		WARN_ON_ONCE(1);
4457 		return;
4458 	}
4459 	*p++ = cpu_to_be32(op->opnum);
4460 	*p++ = rp->rp_status;  /* already xdr'ed */
4461 
4462 	p = xdr_encode_opaque_fixed(p, rp->rp_buf, rp->rp_buflen);
4463 }
4464 
4465 int
4466 nfs4svc_encode_voidres(struct svc_rqst *rqstp, __be32 *p)
4467 {
4468         return xdr_ressize_check(rqstp, p);
4469 }
4470 
4471 void nfsd4_release_compoundargs(struct svc_rqst *rqstp)
4472 {
4473 	struct nfsd4_compoundargs *args = rqstp->rq_argp;
4474 
4475 	if (args->ops != args->iops) {
4476 		kfree(args->ops);
4477 		args->ops = args->iops;
4478 	}
4479 	kfree(args->tmpp);
4480 	args->tmpp = NULL;
4481 	while (args->to_free) {
4482 		struct svcxdr_tmpbuf *tb = args->to_free;
4483 		args->to_free = tb->next;
4484 		kfree(tb);
4485 	}
4486 }
4487 
4488 int
4489 nfs4svc_decode_compoundargs(struct svc_rqst *rqstp, __be32 *p)
4490 {
4491 	struct nfsd4_compoundargs *args = rqstp->rq_argp;
4492 
4493 	if (rqstp->rq_arg.head[0].iov_len % 4) {
4494 		/* client is nuts */
4495 		dprintk("%s: compound not properly padded! (peeraddr=%pISc xid=0x%x)",
4496 			__func__, svc_addr(rqstp), be32_to_cpu(rqstp->rq_xid));
4497 		return 0;
4498 	}
4499 	args->p = p;
4500 	args->end = rqstp->rq_arg.head[0].iov_base + rqstp->rq_arg.head[0].iov_len;
4501 	args->pagelist = rqstp->rq_arg.pages;
4502 	args->pagelen = rqstp->rq_arg.page_len;
4503 	args->tail = false;
4504 	args->tmpp = NULL;
4505 	args->to_free = NULL;
4506 	args->ops = args->iops;
4507 	args->rqstp = rqstp;
4508 
4509 	return !nfsd4_decode_compound(args);
4510 }
4511 
4512 int
4513 nfs4svc_encode_compoundres(struct svc_rqst *rqstp, __be32 *p)
4514 {
4515 	/*
4516 	 * All that remains is to write the tag and operation count...
4517 	 */
4518 	struct nfsd4_compoundres *resp = rqstp->rq_resp;
4519 	struct xdr_buf *buf = resp->xdr.buf;
4520 
4521 	WARN_ON_ONCE(buf->len != buf->head[0].iov_len + buf->page_len +
4522 				 buf->tail[0].iov_len);
4523 
4524 	rqstp->rq_next_page = resp->xdr.page_ptr + 1;
4525 
4526 	p = resp->tagp;
4527 	*p++ = htonl(resp->taglen);
4528 	memcpy(p, resp->tag, resp->taglen);
4529 	p += XDR_QUADLEN(resp->taglen);
4530 	*p++ = htonl(resp->opcnt);
4531 
4532 	nfsd4_sequence_done(resp);
4533 	return 1;
4534 }
4535 
4536 /*
4537  * Local variables:
4538  *  c-basic-offset: 8
4539  * End:
4540  */
4541